Reverse tapered thermoplastic elastomer

Abstract

A retrograded diblock copolymer composition includes a monovinylaromatic monomer A polymerized with a conjugated diene monomer B to form a structure A-[A / B] wherein the [A / B] block is a copolymer of A and B monomers, said copolymer being retrograded, which means that the ratio of B to A near A blocks is lower relative to the ratio of B to A away from A blocks. The [A / B] block preferably has a vinyl content that is higher near the A block relative to the vinyl content away from the A block. The diblock copolymer is preferably partially coupled or formed with a multifunctional initiator to provide a mixture of a diblock copolymer composition and a linear (A-[A / B])-X-([B / A]-A) structure and / or a coupled radial and / or multi-arm (A-[A / B]) n-X structure wherein X is a residue of a coupling agent or initiator. Bitumen and binder compositions are prepared from the diblock copolymer compositions and mixtures.

Description

Technical Field

[0001] The present invention relates to a reverse tapered thermoplastic elastomer, a reinforced material containing the polymer and an article made of the reinforced material. Background Art

[0002] Anionic polymerization is a well-known technique for making elastomers. Commercial polymers commonly prepared by anionic polymerization processes include elastomers such as polybutadiene, polyisoprene, and styrene-diene rubber; and thermoplastic elastomers such as block copolymers of styrene, butadiene, and / or isoprene having different block sizes and numbers.

[0003] Among the polymers prepared by anionic polymerization, commercially available styrene-diene rubbers such as tapered diblock copolymers of conjugated dienes and monovinyl aromatic monomers have long-standing commercial importance due to their processing properties in many applications and their unique properties. Special processing characteristics such as high extrudability and excellent flowability and mechanical properties such as high hardness, low shrinkage and high wear resistance have become a desirable balance of polymer properties in many high-yield applications. In addition, commercially available thermoplastic elastomers such as triblock copolymers of styrene, butadiene and / or isoprene (SBn, SBS, SIS, SIBS, etc.) with different macro- and microstructures are widely used due to their reinforcing properties in many applications and their thermoplastic properties.

[0004] The polymer itself prepared by anionic polymerization can be used as the elastomer used for tire and other industries, adhesives, sealants and coatings. In addition, the polymer prepared by anionic polymerization can be used to change the characteristics of various materials such as asphalt, plastics and rubber. For example, the polymer prepared by anionic polymerization can be used as a compatibilizer and reinforcing agent in asphalt. However, many styrene / butadiene-based polymers prepared by anionic polymerization are not fully compatible, and limited success is obtained in the enhancement of the asphalt for paving and roofing applications. Although linear and nonlinear styrene / butadiene-based polymers are widely used in reinforcing asphalt, the problems related to the dispersibility of the polymer prepared by anionic polymerization in asphalt formulations and the morphological stability of the resulting polymer-modified asphalt blends are finally produced to the storage and long-term performance of modified asphalt, such as the performance grade PG for paving and the high and low temperature properties for roofing applications. In the case where the polymer of anionic polymerization is used for pressure-sensitive and non-pressure-sensitive hot melt and solvent-based adhesives used for adhesive tapes and labels, contact and sprayable applications, similar problems have occurred.

[0005] Polymers prepared by anionic polymerization can be modified in order to improve their properties for their intended applications. Over the years, many modification pathways have been developed. The most common modification pathways include: molecular weight; molecular weight distribution; monomer composition; diene microstructure; monomer sequence length distribution; stereochemistry; monomer addition order and sequencing; chain coupling by reaction of polyfunctional species with active anions to synthesize polymers with linear, radial, comb-like, arm-like, branched, or hyperbranched structures; and combinations of the above modifications. More complex modification pathways include: introduction of chemical functional groups by end-capping reactions or functional initiators; polymerization with polyfunctional initiators to directly synthesize polymers with linear, radial, comb-like, arm-like, branched, or hyperbranched structures; hydrogenation of residual double bonds; and combinations of the above modifications.

[0006] However, it is still highly desirable to combine the unique processing properties of tapered diblock copolymers with the thermoplastic properties of triblock copolymers to improve the balance between processability and reinforcement in many applications. It is desirable to further develop elastomeric compositions and find ways to prepare those compositions by anionic polymerization so as to combine the best properties of the above-mentioned commercially available polymers, which are generally a compromise between polymer properties. Therefore, it is desirable to develop a method for preparing polymers by anionic polymerization to produce elastomeric compositions that are more suitable for processing, more dispersible and more compatible with a variety of materials and other substrates, including asphalt, adhesive and sealant ingredients, and suitable for meeting the reinforcement requirements of a wide range of applications such as paving, roofing, shingles, waterproof membranes, adhesive tapes and labels, contact and sprayable adhesives and sealants.

[0007] Now surprisingly, a novel inversely tapered thermoplastic elastomer composition has been discovered that achieves a better balance between processability and reinforcement properties in various asphalt, adhesive and sealant applications. The novel inversely tapered thermoplastic elastomer composition provides the above applications with the advantages of easy processing, such as short dispersion time, high compatibility, low mixing temperature, low viscosity, excellent storage stability, and better reinforcement advantages, such as high elastic response, wide performance grade range, high adhesion, higher filler loading capacity, excellent bond strength and shear resistance, and better high and low temperature property compromise. Summary of the invention

[0008] The present invention provides a reverse tapered thermoplastic elastomer composition, a method for preparing the polymer, a polymer blend and a mixture containing the polymer, an asphalt and adhesive composition containing the polymer, a reinforcing material containing the polymer, and an article made from the reinforced material.

[0009] The present invention provides an inversely tapered diblock copolymer composition comprising units of at least one monovinyl aromatic monomer, A, polymerized with units of at least one conjugated diene monomer, B, to form a structure A-[A / B], wherein the A block comprises a homopolymer of monovinyl aromatic monomer units, wherein the [A / B] block is a copolymer of monovinyl aromatic monomer units and conjugated diene monomer units, wherein the [A / B] block is inversely tapered such that the ratio of B to A is lower near the A block relative to the ratio of B to A away from the A block. The inversely tapered diblock A-[A / B] copolymer is preferably further defined as having a vinyl content of at least 15 wt % based on the amount of conjugated diene units in the diblock copolymer. The [A / B] block is preferably further defined as having a higher vinyl content near the A block relative to the vinyl content away from the A block.

[0010] The present invention also provides a reverse tapered thermoplastic elastomer (CTTE) composition comprising units of at least one monovinyl aromatic monomer A and units of at least one conjugated diene monomer B and having a linear structure (A-[A / B])-X-([B / A]-A) and / or a coupled radial and / or multi-arm structure (A-[A / B])nX, wherein X is a residue of a coupling agent, wherein n is an integer from 2 to about 30, wherein the CTTE composition has outer blocks and / or end blocks A which are polymers of monovinyl aromatic monomer units A, wherein the CTTE composition has a midblock which is a copolymer of monovinyl aromatic monomer units A and conjugated diene monomer units B, wherein the midblock has a central region between the terminal regions, and wherein the B / A ratio is higher and the vinyl content is preferably lower in the central region than in the terminal regions.

[0011] One embodiment of the present invention is a mixture of the above-mentioned inverse tapered diblock copolymer composition and the CTTE composition. The mixture can be achieved by partially coupling the inverse tapered diblock copolymer composition or by selecting a suitable initiator. Using an initiator route, the present invention provides a reverse tapered thermoplastic elastomer (CTTE) composition comprising units of at least one monovinyl aromatic monomer A and units of at least one conjugated diene monomer B, having a structure X-([A / B]-A) and / or a linear structure (A-[B / A])-X-([A / B]-A) and / or a coupled radial and / or multi-arm structure X-([A / B]-A)n, wherein X is the residue of a monofunctional and / or multifunctional initiator, wherein n is an integer from 1 to about 30, wherein the CTTE composition has outer blocks and / or end blocks A that are polymers of monovinyl aromatic monomer units A, wherein the CTTE composition has a midblock that is a copolymer of monovinyl aromatic monomer units A and conjugated diene monomer units B, wherein the midblock has a central region between the terminal regions, and the B / A ratio is lower and the vinyl content is higher in the central region than in the terminal regions.

[0012] Using a coupling route, the present invention provides a reverse tapered thermoplastic elastomer (CTTE) composition comprising a reverse tapered diblock A-[A / B] copolymer comprising at least one monovinyl aromatic monomer A and at least one conjugated diene monomer B, wherein the [A / B] block is reverse tapered such that the ratio of B to A is lower near the A block relative to the ratio of B to A away from the A block, and wherein the reverse tapered diblock A-[A / B] copolymer preferably has a vinyl content of at least 15 wt. % based on the amount of conjugated diene units in the diblock copolymer, the composition further comprising a reverse tapered diblock A-[A / B] copolymer obtained by coupling the reverse tapered diblock A-[A / B] copolymer with a coupling agent. A block copolymer prepared by partial coupling, wherein the block copolymer has a linear structure (A-[A / B])-X-([B / A]-A) and / or a coupled radial and / or multi-arm structure (A-[A / B])nX, wherein X is the residue of a coupling agent, wherein n is an integer from 2 to about 30, wherein the CTTE composition has outer blocks and / or terminal blocks A, which are polymers of monovinyl aromatic monomer units A, wherein the CTTE composition has a midblock which is a copolymer of monovinyl aromatic monomer units A and conjugated diene monomer units B, wherein the midblock has a central region between terminal regions, and the B / A ratio is higher and the vinyl content is lower in the central region than in the terminal regions.

[0013] In another embodiment, the present invention provides an inversely tapered thermoplastic elastomer composition made from a conjugated diene monomer (B) and a monovinyl aromatic monomer (A). The inversely tapered thermoplastic elastomer composition is characterized by having: (a) an inversely tapered diblock A-[A / B] copolymer; (b) a block copolymer selected from a linear triblock copolymer, a multi-arm coupled block copolymer, and a mixture thereof; and (c) wherein the ratio of (a) to (b) in the inversely tapered thermoplastic elastomer composition is from about 1:5 to about 5:1. The inversely tapered thermoplastic elastomer composition achieves a better balance between processability and enhanced performance for various asphalt, adhesive and sealant applications. The novel inversely tapered thermoplastic elastomer composition provides the above-mentioned applications with the advantages of easy processing, such as short dispersion time, higher compatibility, low mixing temperature, low viscosity, excellent storage stability and better enhanced advantages, such as high elastic response, a wide range of performance grades, high adhesion, higher filler loading capacity, excellent cohesive strength and shear resistance, and a better compromise between high temperature and low temperature performance. These processability and reinforcement advantages make the inversely tapered thermoplastic elastomer compositions suitable for meeting the requirements of a wide range of applications such as paving, roofing, shingles, waterproofing membranes, coatings, tapes and labels, contact and sprayable adhesives and sealants.

[0014] The reverse tapered thermoplastic elastomer composition according to the present invention preferably comprises:

[0015] (a) an inverse tapered diblock A-[A / B] copolymer comprising at least one conjugated diene monomer and at least one monovinyl aromatic monomer, wherein the diblock copolymer preferably has: a peak molecular weight of 20,000 to 250,000; a monovinyl aromatic homopolymer block A preferably having a peak molecular weight of at least 5,000; and an inverse tapered copolymer block [A / B] preferably having a vinyl content of at least 15 weight percent based on the amount of conjugated diene units in the diblock copolymer; and

[0016] (b) a block copolymer comprising at least one conjugated diene monomer and at least one monovinyl aromatic monomer, wherein the block copolymer preferably has at least two homopolymer blocks of monovinyl aromatic monomer and at least one copolymer block of monovinyl aromatic monomer and conjugated diene monomer, wherein the block copolymer is selected from: a linear triblock copolymer having a peak molecular weight preferably at least about 1.5 times the peak molecular weight of the inverse tapered diblock copolymer described in (a), a multi-arm coupled block copolymer having a peak molecular weight at least about 2.5 times the peak molecular weight of the inverse tapered diblock copolymer described in (a), and mixtures thereof, wherein each block copolymer has a monovinyl aromatic homopolymer block A having a peak molecular weight preferably of at least 5,000 and an inverse tapered copolymer block [A / B] having a vinyl content preferably of at least 15 weight percent based on the amount of conjugated diene units in the block copolymer; and preferably,

[0017] (c) wherein the ratio of (a) to (b) in the inversely tapered thermoplastic elastomer composition is from about 1:5 to about 5:1.

[0018] The inversely tapered thermoplastic elastomer composition according to the present invention having an inversely tapered diblock A-[A / B] copolymer and a block copolymer formed by partial coupling or by a multifunctional initiator preferably has:

[0019] (a) a weight average molecular weight of about 30,000 to about 500,000 g / mol;

[0020] (b) the total amount of monovinyl aromatic monomers in the inversely tapered thermoplastic elastomer composition is from about 10 weight percent to about 55 weight percent; and

[0021] (c) a total vinyl configuration content of about 15 weight percent to about 90 weight percent based on the total amount of conjugated dienes in the inverse tapered thermoplastic elastomer composition.

[0022] Another embodiment of the present invention is a method for preparing an inverse tapered thermoplastic elastomer composition comprising: adding a solvent, a polar modifier or a mixture of polar modifiers, and a monovinyl aromatic monomer to a reactor to form an initial reaction mixture, wherein the amount of polar modifier in the initial reaction mixture is less than 10 wt %; adding an organolithium initiator compound to the reactor and anionically polymerizing the monomer to form a monovinyl aromatic homopolymer block A having a peak molecular weight of preferably at least 5,000; adding additional monovinyl aromatic monomer and simultaneously beginning to meter conjugated diene monomer into the reactor at a predetermined dosage rate for a predetermined period of time, wherein the conjugated diene monomer is preferably added at a rate lower than the monovinyl aromatic monomer, and copolymerizing to form an inverse tapered copolymer block [A / B] having a vinyl content of preferably at least 15 wt % based on the amount of conjugated diene units in the diblock copolymer, thereby obtaining a peak molecular weight of preferably 20,000 to 20,000. 50,000 of a reverse tapered diblock A-[A / B] copolymer; and adding a coupling agent or a combination of coupling agents to partially couple the reverse tapered diblock A-[A / B] copolymer to form a block copolymer, which is a linear triblock copolymer, a multi-arm coupled block copolymer, or a mixture thereof; wherein the solvent, polar modifier, conjugated diene monomer, and monovinyl aromatic monomer constitute the total reaction mixture, wherein the amount of polar modifier is less than 5 wt % of the total reaction mixture, wherein the peak molecular weight of the linear triblock copolymer is preferably at least about 1.5 times the peak molecular weight of the reverse tapered diblock A-[A / B] copolymer, wherein the peak molecular weight of the multi-arm coupled block copolymer is preferably at least about 2.5 times the peak molecular weight of the reverse tapered diblock A-[A / B] copolymer, and wherein in the reverse tapered thermoplastic elastomer composition, the ratio of the reverse tapered diblock A-[A / B] copolymer to the block copolymer is preferably from about 1:5 to about 5:1.

[0023] The present invention provides compositions and articles made from inversely tapered thermoplastic elastomer compositions, reinforced materials made from mixtures of inversely tapered thermoplastic elastomer compositions and materials to be reinforced, and articles made from reinforced materials. The present invention provides novel inversely tapered thermoplastic elastomer compositions having enhanced adhesion to specific substrates and blends thereof with other block copolymers, and articles made from materials having enhanced adhesion. The inversely tapered thermoplastic elastomer compositions of the present invention achieve a better balance between processability and reinforcement performance for various asphalt, adhesive and sealant applications. The inversely tapered thermoplastic elastomer compositions provide these applications with advantages of easy processing, such as short dispersion time, higher compatibility, lower mixing temperature, lower viscosity, excellent storage stability and better reinforcement advantages, such as higher elastic response, a wide range of performance grades, higher adhesion, higher filler loading capacity, excellent cohesive strength and shear resistance, and a better compromise between high and low temperature performance. These processability and reinforcement advantages make the novel inversely tapered thermoplastic elastomer compositions suitable for meeting the requirements of a wide range of applications such as road paving, roofing, shingles, waterproofing membranes, tapes and labels, contact and sprayable adhesives and sealants.

[0024] One embodiment of the present invention is an asphalt and / or bitumen composition comprising asphalt and / or bitumen and a first inversely tapered thermoplastic elastomer (first CTTE) composition, wherein the asphalt and / or bitumen composition comprises 0.5 to 25 weight percent of the first CTTE composition, and wherein the first CTTE composition comprises units of at least one monovinyl aromatic monomer, A, polymerized with units of at least one conjugated diene monomer, B, to form an inversely tapered diblock A-[A / B] copolymer, wherein the A block comprises a polymer of monovinyl aromatic monomer units, wherein the [A / B] block is a copolymer of monovinyl aromatic monomer units and conjugated diene monomer units, and wherein the [A / B] block is inversely tapered such that the ratio of B to A is lower proximal to the A block relative to the ratio of B to A distal to the A block. The total amount of units of the conjugated diene monomer B is preferably greater than 55 wt% of the first CTTE composition, and the vinyl content is preferably higher near the A block in the inverse tapered diblock A-[A / B] copolymer relative to the vinyl content away from the A block. The [A / B] block of the first CTTE composition preferably comprises 2-40 wt% of the monovinyl aromatic monomer A and preferably 60-98 wt% of the conjugated diene monomer B.

[0025] The asphalt and / or petroleum asphalt composition preferably further comprises a second inversely tapered thermoplastic elastomer (second CTTE) composition. The second CTTE composition comprises units of at least one monovinyl aromatic monomer A and units of at least one conjugated diene monomer B, and has a linear structure (A-[A / B])-X-([B / A]-A) and / or a coupled radial and / or multi-arm structure (A-[A / B])nX, wherein X is the residue of a coupling agent or a multifunctional initiator, wherein n is an integer from 2 to 30, wherein the second CTTE composition has outer blocks and / or end blocks A that are polymers of monovinyl aromatic monomer units A, wherein the second CTTE composition has a midblock that is a copolymer of monovinyl aromatic monomer units A and conjugated diene monomer units B, wherein the midblock has a central region between the terminal regions, and wherein the B / A ratio is higher in the central region than in the terminal regions.

[0026] Another embodiment of the present invention is an asphalt and / or petroleum asphalt composition comprising asphalt and / or petroleum asphalt and a second CTTE composition, wherein the asphalt and / or petroleum asphalt composition comprises 0.5 to 25 weight percent of the second CTTE composition, wherein there is substantially no or almost no first CTTE composition, which can be achieved by completely or nearly completely coupling the first CTTE composition.

[0027] Another embodiment of the present invention is an adhesive composition comprising a first CTTE composition and a tackifying resin, preferably further comprising at least one additive selected from the group consisting of a plasticizer, a solvent, a coupling agent, a crosslinking agent, a photoinitiator, and an antioxidant. The adhesive composition preferably further comprises a second CTTE composition. An alternative embodiment of the present invention is an adhesive composition comprising a second CTTE composition and a tackifying resin, preferably further comprising at least one additive selected from the group consisting of a plasticizer, a solvent, a coupling agent, a crosslinking agent, a photoinitiator, and an antioxidant, and wherein the adhesive composition comprises 0.5 to 50 wt % of the second CTTE composition, wherein substantially no or almost no first CTTE composition is present, which can be achieved by completely or almost completely coupling the first CTTE composition. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The monomer distribution in the [A / B] midblock of the (A-[A / B])n inverse tapered thermoplastic elastomer CTTE 14 is depicted.

[0029] Figure 2 The monomer distribution in the [A / B] midblock of the inverse tapered thermoplastic elastomer CTTE 16 is depicted.

[0030] Figure 3The monomer distribution in the [A / B] midblock of the inversely tapered thermoplastic elastomers CTTE 14 vs. CTTE 16 of the present invention is depicted.

[0031] Figure 4 The monomer distribution in the midblock of the inversely tapered thermoplastic elastomers CTTE 17 vs. CTTE 19 of the present invention is depicted.

[0032] Figure 5 Depicted is the monomer distribution in the [B / A] controlled distribution midblock example comparing the [A / B] midblock pairs CD 1 and CD 2 of CTTE 20, 37 and 38 of the present invention.

[0033] Figure 6 Depicted are 20× fluorescence microscopy images of several polymer modified asphalts (PMAs) monitored throughout the mixing process at 190°C and prepared with 2.3 wt% polymer. Each arrow points to the image corresponding to the mixing time when complete polymer dispersion was observed for the various PMA blends. The dispersion performance of CTTE Prototype Dyne 143A in PMA was compared to PMA blends of commercially available polymers and is described in Example 7.

[0034] Figure 7 Depicted are 20× fluorescence microscopy images of several polymer modified asphalts (PMAs) monitored throughout the mixing process at 190°C and prepared with 6 wt% polymer. Each arrow points to the image corresponding to the mixing time when complete polymer dispersion was observed for the various PMA blends. The dispersion performance of CTTE Prototype Dyne 143A in PMA was compared to PMA blends of commercially available polymers and is described in Example 7.

[0035] Figure 8 The maximum performance grade (AASHTO standard PG) temperature of several polymer modified asphalts (PMAs) monitored throughout the mixing process at different temperatures (170-190°C) and prepared with 2.3wt% polymer is depicted. The failure temperature performance of the extended production (mixing) time of CTTEPrototype Dyne 143A PMA is compared with PMA blends of commercial polymers and described in Example 7. DETAILED DESCRIPTION

[0036] The present invention provides a reverse tapered thermoplastic elastomer composition, a method for producing the polymer, a polymer blend and mixture containing the polymer, a reinforced material containing the polymer, and an article made from the reinforced material.

[0037] One aspect of the present invention provides a novel inversely tapered thermoplastic elastomer composition made from a conjugated diene monomer (B) and a monovinyl aromatic monomer (A). The novel inversely tapered thermoplastic elastomer composition is characterized in that it has: (a) an inversely tapered diblock A-[A / B] copolymer; (b) a block copolymer selected from a linear triblock copolymer, a multi-arm coupled block copolymer, and a mixture thereof; and (c) wherein the ratio of (a) to (b) in the inversely tapered thermoplastic elastomer composition is from about 1:5 to about 5:1. For various asphalt, adhesive and sealant applications, the novel inversely tapered thermoplastic elastomer composition achieves a better balance between processability and enhanced performance. The novel inversely tapered thermoplastic elastomer composition provides the above-mentioned applications with the advantages of easy processing, such as short dispersion time, low mixing temperature, low viscosity, excellent storage stability, and better enhancement advantages, such as high elastic response, wide performance grade range, high adhesion, higher filler loading capacity, and better high and low temperature property compromise. These advantages of processability and reinforcement make the novel inversely tapered thermoplastic elastomer compositions suitable for meeting the requirements of a wide range of applications such as paving, roofing, shingles, waterproofing membranes, adhesive tapes and labels, contact and sprayable adhesives, and sealants.

[0038] The novel reverse tapered thermoplastic elastomer composition of the present invention comprises:

[0039] (a) an inverse tapered diblock A-[A / B] copolymer comprising at least one conjugated diene monomer and at least one monovinyl aromatic monomer, the diblock copolymer further characterized as having: a peak molecular weight of 20,000 to 250,000; a monovinyl aromatic homopolymer block A having a peak molecular weight of at least 5,000; and an inverse tapered copolymer block [A / B] having a vinyl content of at least 15 weight percent based on the amount of conjugated diene units in the diblock copolymer; and

[0040] (b) a block copolymer comprising at least one conjugated diene monomer and at least one monovinyl aromatic monomer, the block copolymer further characterized as having: at least two homopolymer blocks of monovinyl aromatic monomer and at least one copolymer block of monovinyl aromatic monomer and conjugated diene monomer; wherein the block copolymer is selected from the group consisting of a linear triblock copolymer having a peak molecular weight of at least about 1.5 times the peak molecular weight of the inverse tapered diblock copolymer described in (a), a multi-arm coupled block copolymer having a peak molecular weight of at least about 2.5 times the peak molecular weight of the inverse tapered diblock copolymer described in (a), and mixtures thereof; wherein each block copolymer has a monovinyl aromatic homopolymer block A having a peak molecular weight of at least 5,000, and an inverse tapered copolymer block [A / B] having a vinyl content of at least 15 weight percent based on the amount of conjugated diene units in the block copolymer; and

[0041] (c) wherein the ratio of (a) to (b) in the inversely tapered thermoplastic elastomer composition is from about 1:5 to about 5:1.

[0042] The novel inversely tapered thermoplastic elastomer composition according to the present invention is characterized in that:

[0043] (a) the inversely tapered thermoplastic elastomer composition has a weight average molecular weight of about 30,000 g / mol to about 500,000 g / mol;

[0044] (b) the total amount of monovinyl aromatic monomers in the inversely tapered thermoplastic elastomer composition is from about 10 weight percent to about 55 weight percent; and

[0045] (c) a total vinyl configuration content of about 15 wt % to about 90 wt % based on the total amount of conjugated dienes in the inverse tapered thermoplastic elastomer composition.

[0046] The polymer prepared by anionic polymerization includes thermoplastic polymers, elastomeric polymers and thermoplastic-elastic polymers. The polymer can be a homopolymer or a copolymer, including a tapered copolymer, a random copolymer and a block copolymer. In the block copolymer prepared by anionic polymerization, the tapered diblock copolymer of conjugated diene and monovinyl aromatic monomer has long-term commercial importance due to its performance in many applications and its unique properties. Special processing characteristics such as high extrudability and excellent fluidity and mechanical properties such as high hardness, low shrinkage and high wear resistance have become the balance of desirable polymer properties in many high-yield applications. In addition, commercially available thermoplastic elastomers such as styrene, butadiene and / or isoprene with different macro and micro structures (SBn, SBS, SIS, SIBS, etc.) are widely used due to its enhanced performance and its thermoplastic properties in many applications. However, it is still highly desirable to combine the unique processing properties of tapered diblock copolymers with the thermoplastic properties of triblock copolymers so as to improve the balance between processability and enhanced performance in many applications.

[0047] Alkyllithium-initiated copolymerization of conjugated dienes and monovinyl aromatic monomers in hydrocarbon solvents in the absence of polar additives produces an interesting class of structures with compositional heterogeneity along the copolymer chain, which are generally referred to as tapered, gradual or gradient diblock copolymer structures. Although the stabilities of the carbanion chain ends corresponding to the conjugated diene (1) and monovinyl aromatic (2) monomers are similar, relatively large differences are observed between the monomer reactivity ratios (i.e., r1>10 and r2<0.1). In contrast to the observed faster homopolymerization of monovinyl aromatic monomers relative to conjugated diene monomers, in the initial stages of the copolymerization, the less reactive conjugated diene monomer is preferentially incorporated into the copolymer chain until it is nearly exhausted, forming a diene-rich tapered block B with a gradually changing composition, and then in the final stages, most of the monovinyl aromatic monomer forms the terminal polystyrene block A.

[0048] B-(B / A)-A

[0049] In addition, during copolymerization in hydrocarbon solvents and in the absence of polar additives, a distinct intermediate stage appears, which forms a small, sharp and steep intermediate phase-(B / A)- with a sudden change in composition, which serves as a transition between the two large A blocks and the B block in the copolymer chain. The lower melt viscosity of the tapered diblock copolymer compared to the pure diblock copolymer with the same composition and molecular weight is attributed to the presence of this small intermediate phase, which weakens the intra-chain and inter-chain repulsion and enhances the mixing between dissimilar adjacent blocks. Because the copolymerization of conjugated dienes and monovinyl aromatic monomers initiated by alkyl lithium under the above conditions shows a statistically random distribution trend of monomer units (i.e., r1r2 is about 0.5) mainly due to the large difference in the monomer reactivity ratio, both block B and the intermediate phase-(B / A)-have composition changes along the copolymer chain, which are directly dependent on the instantaneous relative monomer concentration. Thus, an initial relatively small concentration of monovinyl aromatic monomer is incorporated almost randomly and primarily as isolated aromatic units into the diene-rich tapered block B. In contrast, an intermediate relatively large concentration of monovinyl aromatic monomer is statistically incorporated primarily as long aromatic sequences into the small, sharp and steep mesophase -(B / A)-, which should quickly become aromatic-rich segments with residual isolated diene units.

[0050] In the absence of polar additives, copolymerization of conjugated dienes and monovinyl aromatic monomers with alkyl lithiums generally produces tapered diblock copolymers with low vinyl configuration content (1,2-diene microstructure). During copolymerization of conjugated dienes and monovinyl aromatic monomers with alkyl lithium initiators, polar additives act as both randomizers and microstructure modifiers. As the concentration of polar additives increases, the relatively large differences between monomer reactivity ratios decrease, which causes the copolymerization behavior to gradually change from statistical to random, and the monomer sequence length distribution to change from tapered diblock to random diblock and then to a fully random copolymer structure. This randomization effect is generally accompanied by a corresponding modification effect of increasing the vinyl configuration content. Although both effects depend directly on the concentration of the polar additive, and the modification effect is inversely proportional to the polymerization temperature, the extent and specific behavior of each effect are particularly dependent on the type and specific properties of the polar additive. Various polar additives can be combined to overcome some of the barriers and obtain synergistic effects or desired differential effects on the monomer sequence length distribution and / or 1,2-diene microstructure.

[0051] By controlling the monomer addition sequence, polymerization sequence, feed rate and feed composition; the combination, type, concentration, addition sequence and feed rate of polar additives; polymerization temperature behavior and conditions; and relative block size and molecular weight, the design of the novel inverse tapered thermoplastic elastomer composition can be customized to include the characteristics and features according to the present invention, namely (a) an inverse tapered diblock A-[A / B] copolymer; (b) a block copolymer selected from a linear triblock copolymer, a multi-arm coupled block copolymer and a mixture thereof; and (c) wherein the ratio of (a) to (b) in the inverse tapered thermoplastic elastomer composition is from about 1:5 to about 5:1. These design characteristics are suitable qualities for achieving the desired overall application performance in blends with various materials and other substrates, including asphalt, adhesive and sealant ingredients, rubber and plastics. The desired overall application performance is a balance between maximized processing properties such as low melt viscosity, high dispersibility, high compatibility, high miscibility and / or high adhesion and good elastic properties and thermoplastic properties. The novel inversely tapered thermoplastic elastomer composition of the present invention is very suitable for specific applications including asphalt enhancers, modifiers and morphology stabilizers. Other suitable applications include compatibilizers, viscosity modifiers, flow modifiers, processing aids, rheology control agents and impact modifiers for plastics and plastic blends and alloys and composite materials. The novel inversely tapered thermoplastic elastomer composition can also be designed to have customized properties to provide highly processable adhesives with optimal adhesion to polar substrates, which is useful in typical adhesive and sealant applications. For various asphalt, adhesive and sealant applications, the novel inversely tapered thermoplastic elastomer composition achieves a better balance between processability and enhanced performance. The novel inversely tapered thermoplastic elastomer composition provides the advantages of easy processing for the above-mentioned applications, such as short dispersion time, low mixing temperature, low viscosity, excellent storage stability, and better enhancement advantages, such as high elastic response, wide performance grade range, high adhesion, higher filler loading capacity, and better high and low temperature properties compromise. These advantages of processability and reinforcement make the novel inversely graded thermoplastic elastomer compositions suitable for meeting the requirements of a wide range of applications such as paving, roofing, shingles, waterproofing membranes, adhesive tapes and labels, contact and sprayable adhesives, and sealants.

[0052] Another aspect of the present invention provides a method for preparing a reverse tapered thermoplastic elastomer composition, the method comprising: reacting at least one conjugated diene monomer and at least one monovinyl aromatic monomer under anionic polymerization conditions in the presence of a suitable polar modifier or combination of polar modifiers; and forming a composition of the present invention, the composition comprising:

[0053] (a) an inverse tapered diblock A-[A / B] copolymer comprising at least one conjugated diene monomer and at least one monovinyl aromatic monomer, the diblock copolymer further characterized as having: a peak molecular weight of 20,000 to 250,000; a monovinyl aromatic homopolymer block A having a peak molecular weight of at least 5,000; and an inverse tapered copolymer block [A / B] having a vinyl content of at least 15 weight percent based on the amount of conjugated diene units in the diblock copolymer; and

[0054] (b) a block copolymer comprising at least one conjugated diene monomer and at least one monovinyl aromatic monomer, the block copolymer further characterized as having: at least two homopolymer blocks of monovinyl aromatic monomer and at least one copolymer block of monovinyl aromatic monomer and conjugated diene monomer; wherein the block copolymer is selected from the group consisting of: a linear triblock copolymer having a peak molecular weight of at least about 1.5 times the peak molecular weight of the inverse tapered diblock copolymer described in (a), a multi-arm coupled block copolymer having a peak molecular weight of at least about 2.5 times the peak molecular weight of the inverse tapered diblock copolymer described in (a), and mixtures thereof; wherein each block copolymer has a monovinyl aromatic homopolymer block A having a peak molecular weight of at least 5,000, and an inverse tapered copolymer block [A / B] having a vinyl content of at least 15 weight percent based on the amount of conjugated diene units in the block copolymer; and

[0055] (c) wherein the ratio of (a) to (b) in the inversely tapered thermoplastic elastomer composition is from about 1:5 to about 5:1.

[0056] Another embodiment of the present invention is a method for preparing a reverse tapered thermoplastic elastomer composition, the method comprising: adding a solvent, a polar modifier or a combination of multiple polar modifiers, and a monovinyl aromatic monomer to a reactor to form an initial reaction mixture, wherein the amount of polar modifier in the initial reaction mixture is less than 10 wt %; adding an organolithium initiator compound to the reactor and anionically polymerizing the monomer to form a monovinyl aromatic homopolymer block A having a peak molecular weight of at least 5,000; adding additional monovinyl aromatic monomer, and simultaneously starting to dose a conjugated diene monomer into the reactor at a predetermined dosage rate for a predetermined time, and copolymerizing to form a reverse tapered copolymer block [A / B] having a vinyl content of at least 15 wt % based on the amount of conjugated diene units in the diblock copolymer, and obtaining a reverse tapered diblock A-[A / B] copolymer; and adding a coupling agent or a combination of coupling agents to partially couple the inverse tapered diblock A-[A / B] copolymer to form a block copolymer, the block copolymer being a linear triblock copolymer, a multi-arm coupled block copolymer or a mixture thereof; wherein the solvent, polar modifier, conjugated diene monomer, and monovinyl aromatic monomer comprise a total reaction mixture, wherein the amount of the polar modifier is less than 5 wt % of the total reaction mixture, wherein the peak molecular weight of the linear triblock copolymer is at least about 1.5 times the peak molecular weight of the inverse tapered diblock A-[A / B] copolymer, wherein the peak molecular weight of the multi-arm coupled block copolymer is at least about 2.5 times the peak molecular weight of the inverse tapered diblock A-[A / B] copolymer, and wherein the ratio of inverse tapered diblock A-[A / B] copolymer to block copolymer in the inverse tapered thermoplastic elastomer composition is from about 1:5 to about 5:1.

[0057] The present invention also provides a method for preparing a novel inverse tapered thermoplastic elastomer composition, the method comprising reacting at least one conjugated diene monomer (B) with at least one monovinyl aromatic monomer (A) under anionic polymerization conditions in the presence of a suitable polar additive or a combination of multiple polar additives to form an inverse tapered diblock copolymer A-[A / B], then adding a suitable coupling agent to form a block copolymer with thermoplastic properties, and finally obtaining an inverse tapered thermoplastic elastomer composition. Therefore, in a preferred embodiment of the present invention, the inverse tapered diblock A-[A / B] copolymer undergoes sequence polymerization to independently manipulate the size, composition and microstructure of the desired inverse tapered copolymer block [A / B], including controlling its monovinyl aromatic monomer sequence length and conjugated diene monomer vinyl distribution (1,2-diene microstructure). Sequential polymerization also allows adjustment of the relative size of the monovinyl aromatic homopolymer block A and the relative order of the blocks in the copolymer, thus first polymerizing the monovinyl aromatic homopolymer block A adjacent to the inverse tapered copolymer block [A / B] to form the desired inverse tapered diblock A-[A / B] copolymer.

[0058] The monovinyl aromatic monomer sequence length and conjugated diene monomer vinyl distribution of the reverse tapered copolymer block [A / B] can be manipulated by controlling the polymerization temperature profile. The polymerization step is allowed to proceed in an isothermal mode for a predetermined residence time or in a quasi-adiabatic mode until the peak temperature. The isothermal mode can be used to manipulate a uniform vinyl distribution along the copolymer chain and achieve a maximized vinyl content relative to the amount of polar additive added and the set temperature of the polymerization mixture, so the monovinyl aromatic monomer sequence length depends only on the instantaneous relative monomer concentration. The quasi-adiabatic mode can be used to manipulate the vinyl distribution gradient along the copolymer chain, so the monovinyl aromatic monomer sequence length depends not only on the instantaneous relative monomer concentration, but also on the actual temperature profile. The vinyl distribution gradient depends not only on the controlled temperature profile, but also on the initial and final temperatures of the polymerization mixture. The reverse tapered copolymer block [A / B] is manipulated to adjust the desired tapered composition and controlled vinyl distribution, which helps to maximize processing characteristics by increasing flow and reducing melt viscosity, and optimizes compatibility with materials, ingredients and / or substrates used in the desired application.

[0059] In another embodiment of the present invention, the reverse tapered copolymer block [A / B] is a statistically distributed copolymer block of at least one conjugated diene monomer (B) and at least one monovinyl aromatic monomer (A), wherein statistical distribution means that the sequence distribution of monomer units follows a known statistical law. The reverse tapered copolymer block [A / B] has a microstructure with a gradually changing composition, which depends mainly on the amount and temperature profile of the suitable polar additive added to the polymerization mixture. Alternatively or simultaneously, the reverse tapered copolymer block [A / B] can be prepared by adding the conjugated diene monomer to the polymerization mixture at a controlled feed rate while polymerizing the monovinyl aromatic monomer. The conjugated diene monomer is dosed to the reactor at a predetermined dosage rate within a predetermined time to control the instantaneous relative monomer concentration. The polymerization step is allowed to proceed in an isothermal mode for a predetermined residence time or in a quasi-adiabatic mode until the peak temperature. Relative to the typical small mesophase-(B / A)-of copolymerization in the absence of polar additives, the reverse tapered copolymer block [A / B] is enlarged. Manipulation of the enlarged inverse tapered copolymer block [A / B] to adjust its relative size relative to the adjacent monovinyl aromatic homopolymer block A helps to minimize repulsion, maximize compatibility, promote interfacial mixing, and improve toughness and fracture strength. The optimal inverse tapered copolymer block [A / B] is the block introduced into the inverse tapered thermoplastic elastomer composition that provides the best balance between processability and enhanced performance for each application. Those skilled in the art understand the differences in the characteristics, properties, and applicability of these different inverse tapered thermoplastic elastomer compositions.

[0060] In another embodiment of the present invention, each A block is a monovinyl aromatic homopolymer block of at least one monovinyl aromatic monomer. Each A block is manipulated to adjust its relative size [A / B] relative to the inverse tapered copolymer block [A / B] to help achieve the desired application properties.

[0061] The novel inversely tapered thermoplastic elastomer compositions used in the present invention typically have a weight average molecular weight of about 30,000 g / mol to about 500,000 g / mol. This range includes monovinyl aromatic homopolymer blocks A preferably having a peak molecular weight of at least about 8,000 g / mol, inversely tapered diblock A-[A / B] copolymers having a peak molecular weight of preferably about 20,000 g / mol to 250,000 g / mol, and multi-arm coupled block copolymers having a peak molecular weight of preferably about 40,000 g / mol to 750,000 g / mol. Throughout this disclosure, the molecular weights cited are measured using gel permeation chromatography using linear polystyrene standards under ASTM D 3536. The composition of the vinyl aromatic monomer in the inversely tapered thermoplastic elastomer composition is preferably about 10% by weight to about 85% by weight, more preferably about 10% by weight to about 70% by weight, and even more preferably about 10% by weight to 55% by weight. Based on the total amount of conjugated diene monomers in the inverse tapered copolymer block [A / B], the vinyl configuration content of the novel inverse tapered thermoplastic elastomer composition may preferably be from about 15 wt% to about 90 wt%, more preferably from about 15 wt% to about 85 wt%, and even more preferably from about 15 wt% to about 80 wt%. The present invention is not limited to the inverse tapered thermoplastic elastomer composition within the preferred molecular weight, composition and vinyl configuration ranges.

[0062] Examples of inversely tapered thermoplastic elastomer compositions that can be made from anionically polymerizable monomers include, but are not limited to, elastomers and thermoplastic elastomers made from block copolymers or terpolymers of styrene (S), butadiene (B) and / or isoprene (I) having varying block sizes and numbers. Examples of such elastomers and thermoplastic elastomers include: S-[B / S]m, S-[B / S]mS, S-[B / S]mX-[S / B]mS, S-[I / S]m, S-[I / S]mS, S-[I / S]mX-[S / I]mS, S-[B / I / S]m, S-[B / I / S]mS, S-[B / I / S]mX-[S / I]mS, S-[B / I / S]m, S-[B / I / S]mS, S-[B / I / S]mX-[S / I / B]mS, (S-[B / S]m)nX, (S-[I / S]m)nX, (S-[B / I / S]m)nX (wherein m is an integer; and wherein X is the residue of a coupling agent or a multifunctional initiator, and n is an integer from 2 to about 30), which can be used alone or in admixture to obtain inversely tapered thermoplastic elastomer compositions and their hydrogenated, selectively hydrogenated and partially hydrogenated counterparts.

[0063] The novel inversely tapered thermoplastic elastomer composition may be a polymer blend obtained in situ by partial coupling and / or partial initiation with a coupling agent and / or a multifunctional initiator, or a polymer blend of multi-arm, branched or radial polymers obtained by complete coupling and / or complete initiation, and a separately prepared diblock copolymer. The inversely tapered thermoplastic elastomer composition may be a blend prepared in situ by adding a suitable amount of a coupling agent at the end of polymerization of the inversely tapered diblock A-[A / B] copolymer of the present invention, and forming the desired (A-[A / B)nX linear triblock and / or multi-arm coupled block copolymer. Partial coupling is achieved by controlling the stoichiometric ratio of the coupling agent to the active polymer. The reverse tapered thermoplastic elastomer composition can also be a blend prepared in situ by using a suitable multifunctional initiator in combination with a typical monofunctional initiator, such as an alkyl lithium, to initiate the polymerization of the reverse tapered diblock [A / B]-A copolymer of the present invention and form the desired X-([A / B]-A)n linear triblock and / or multi-arm coupled block copolymer. Partial initiation is achieved by controlling the stoichiometric ratio of the multifunctional initiator to the monofunctional initiator. The novel reverse tapered thermoplastic elastomer composition used in the present invention may have 2 to 30 anionically polymerized polymer chains (arms) per initiator or coupling agent molecule. These branched and radial, linear triblock and multi-arm coupled block copolymers may have a peak molecular weight of about 40,000 to about 750,000 g / mol. This includes a reverse tapered thermoplastic elastomer composition having a weight average molecular weight preferably of about 30,000 g / mol to 500,000 g / mol. In some embodiments of the novel inverse tapered thermoplastic elastomer composition, the composition of the vinyl aromatic monomer is preferably from about 10% to about 85% by weight, more preferably from about 10% to about 70% by weight, and even more preferably from about 10% to 55% by weight. Based on the total amount of conjugated diene monomers in the inverse tapered copolymer block [A / B], the vinyl configuration content of the novel inverse tapered thermoplastic elastomer composition may preferably be from about 15% to about 90% by weight, more preferably from about 15% to about 85% by weight, and even more preferably from about 15% to about 80% by weight. The present invention is not limited to inverse tapered thermoplastic elastomer compositions falling within the preferred molecular weight, composition, and vinyl configuration ranges.

[0064] Anionic polymers can be prepared by any suitable method known in the art, such as those described in U.S. Patent Nos. 3,281,383 and 3,753,936, the entire contents of which are incorporated herein by reference. In these methods, anionic polymers are prepared by contacting anionic polymerizable monomers with an organic lithium compound as an initiator. The preferred species of these compounds can be represented by the formula RLi, wherein R is a hydrocarbon group selected from aliphatic, alicyclic and aromatic groups containing 1 to 20 carbon atoms, but higher molecular weight initiators can also be used. Many anionic polymerization initiators are well known and commercially available. Monofunctional organic lithium compounds such as butyl lithium are examples of commonly used initiators. Specific examples of these initiators include methyl lithium, ethyl lithium, tert-butyl lithium, sec-butyl lithium, n-butyl lithium, n-decyl lithium, isopropyl lithium, eicosyl lithium, cycloalkyl lithium compounds such as cyclohexyl lithium and aryl lithium compounds such as phenyl lithium, naphthyl lithium, p-tolyl lithium, 1,1-diphenylhexyl lithium, etc. Monofunctional organolithium compounds substituted with protected polar functional groups can also be used as initiators for anionic polymerization.

[0065] The amount of initiator varies depending on the desired molecular weight of the anionically polymerized polymer.Number average molecular weights between about 20,000 and 350,000 can be obtained by adding about 0.28 to 5.0 millimoles of RLi initiator per mole of monomer corrected by the factor 100 / (MW of monomer).

[0066] Multifunctional organolithium initiators can also be used as initiators to prepare branched and radial, linear triblock or multi-arm block copolymers, with a required functionality of 2 to about 30 anion-polymerized polymer chains (arms) per initiator molecule. Multifunctional organolithium initiators can be easily prepared by direct addition reactions of stoichiometric amounts of monofunctional organolithium compounds and polyvinyl compounds such as 1,3-diisopropenylbenzene, 1,3,5-triisopropenylbenzene, 1,3-bis(1-phenylvinyl)benzene, 1,3,5-tri(1-phenylvinyl)benzene, 1,3-divinylbenzene, 1,3,5-trivinylbenzene, etc. Low molecular weight polyethylene compounds can be used to prepare multifunctional organolithium initiators with high functionality. Monofunctional organolithium compounds such as butyllithium are examples of commonly used initiators for the above-mentioned addition reactions. Specific examples of these commonly used initiators include tert-butyllithium, sec-butyllithium and n-butyllithium. Monofunctional organolithium compounds substituted with protected polar functional groups can also be used to prepare polyfunctional organolithium initiators. Polyfunctional organolithium compounds can be combined among themselves and / or with monofunctional organolithium compounds to partially initiate anionic polymerization with the polyfunctional organolithium compounds. Partial initiation is achieved by controlling the stoichiometric ratio of the polyfunctional initiator to the monofunctional initiator.

[0067] Anionic polymerization is usually carried out in an inert hydrocarbon solvent at a relatively low temperature, under vacuum or inert atmosphere, with highly purified reagents to prevent premature termination of the polymerization reaction. Anionic polymerization can be carried out in a variety of organic solvents. Examples of suitable solvents include but are not limited to pentane, hexane, heptane, octane, cyclopentane, cyclohexane, cycloheptane, benzene, naphthalene, toluene, xylene, methyl ether, methyl ethyl ether, ether, tetrahydrofuran, acetone, methyl ethyl ketone and mixtures thereof. Cyclohexane is particularly suitable for use as a solvent in anionic polymerization.

[0068] Anionic polymerization is generally carried out at a temperature of -100°C to 150°C, preferably -75°C to 75°C. 50% to 90% by weight, preferably 70% to 85% of the reaction solvent is generally used to control the viscosity within the reaction zone. Typical residence times for anionic polymerization vary between 0.1 and 5 hours, preferably from 0.2 to 2 hours, depending on the reaction temperature and initiator level.

[0069] Polar additives known in the art and useful in preparing the inverse tapered thermoplastic elastomer compositions of the present invention are Lewis bases such as ethers and tertiary amines, and Group Ia alkali metal alkoxides and combinations thereof. Specific examples of these suitable ether polar additives include monofunctional, polyfunctional and oligomeric alkyl and cyclic ethers such as dimethyl ether, ethyl ether, ethyl methyl ether, ethyl propyl ether, di-n-propyl ether, tetramethylene oxide (tetrahydrofuran), 1,2-dimethoxyethane, ditetrahydrofuran, ditetrahydrofuranyl propane (DTHFP), combinations thereof, and the like. Specific examples of these suitable tertiary amine polar additives include monofunctional, polyfunctional and oligomeric alkyl and cyclic tertiary amines, such as dimethylethylamine, trimethylamine, triethylamine, N,N,N',N'-tetramethylethylenediamine (TMEDA), N,N,N',N',N"-pentamethyldiethyltriamine, combinations thereof, and the like. Specific examples of these suitable Group Ia alkali metal alkoxides (lithium, sodium, potassium, rubidium and cesium salts) include monofunctional, polyfunctional and oligomeric alkyl and cyclic metal alkoxides, such as sodium tert-butoxide, sodium tert-amylate, sodium menthol, potassium tert-butoxide, potassium tert-amylate, potassium menthol, combinations thereof, and the like.

[0070] The amount of a suitable polar additive is 0.0005 wt % to 50 wt % of the total reaction mixture, and preferably 0.0005 wt % to 10.0 wt % of the total reaction mixture. A more preferred range is about 0.0005 wt % to about 5.0 wt % of the total reaction mixture. The most preferred Lewis bases are TMEDA, THF and DTHFP. A more preferred combination is a combination of two Lewis bases (i.e., an ether and a tertiary amine). A preferred combination is a combination of two alkali metal alkoxides (e.g., lithium and sodium, lithium and potassium). The preferred concentration of the polar additive or the combination of multiple polar additives depends on the type of polar additive or multiple polar additives, and the desired monomer sequence length distribution, microstructure and properties of the reverse tapered copolymer block [A / B]. The desired properties depend on the intended application of the reverse tapered thermoplastic elastomer composition.

[0071] Suitable conjugated dienes for constructing the inversely tapered thermoplastic elastomer composition of the present invention include, but are not limited to, 1,3-butadiene, isoprene, 1,3-pentadiene, methylpentadiene, phenylbutadiene, 2,3-dimethyl-1,3-butadiene, 2,4-hexadiene, 1,3-hexadiene, 1,3-cyclohexadiene, 3,4-dimethyl-1,3-hexadiene, 1,3-octadiene, 4,5-diethyl-1,3-octadiene, and combinations thereof.

[0072] Preferred conjugated dienes for constructing the inversely tapered thermoplastic elastomer composition of the present invention include, but are not limited to, 1,3-butadiene, isoprene or 2-methyl-1,3-butadiene, 2-ethyl-1,3-butadiene, piperylene or 1,3-pentadiene, methylpentadiene, phenylbutadiene, 2,3-dimethyl-1,3-butadiene, 2,4-hexadiene, 1,3-hexadiene, 1,3-cyclohexadiene, 3,4-dimethyl-1,3-hexadiene, 1,3-octadiene, 4,5-diethyl-1,3-octadiene, β-myrcene or 7-methyl-3-methylene-1,6-octadiene, β-farnesene or 7,11-dimethyl-3-methylene-1,6,10-dodecatriene, isomeric mixtures and combinations thereof. These preferred conjugated diene monomers for the inverse tapered thermoplastic elastomer composition of the present invention also include, but are not limited to, bio-sourced and / or bio-based conjugated diene monomers, substituted conjugated diene monomers having at least one substituent selected from C1-C18 vinyl, alkyl or alkoxy, cycloalkyl and / or aromatic groups to modify compatibility and / or reactivity, protected functionalized conjugated diene monomers, isomer mixtures and combinations thereof. The most preferred substituted conjugated diene monomers having at least one substituent to modify compatibility and / or reactivity with C1-C18 vinyl are those in which the substituent has at least one terminal and / or non-terminal vinyl group that increases the vinyl configuration unit without making the substituent susceptible to side reactions during polymerization.

[0073] Suitable monovinyl aromatic monomers for constructing the novel inversely tapered thermoplastic elastomer composition of the present invention include, but are not limited to, styrene and styrene derivatives, such as 3-methylstyrene, α-methylstyrene, p-methylstyrene, α,4-dimethylstyrene, tert-butylstyrene, o-chlorostyrene, 2-butenylnaphthalene, 4-tert-butoxystyrene, 3-isopropenylbiphenyl, 4-vinylpyridine, 2-vinylpyridine and isopropenylnaphthalene, 4-n-propylstyrene, and combinations thereof.

[0074] Preferred vinyl aromatic monomers for constructing the novel inversely tapered thermoplastic elastomer compositions of the present invention include, but are not limited to, styrene and styrene derivatives, such as 3-methylstyrene, p-methylstyrene or 4-methylstyrene, vinyl toluene, α-methylstyrene or alpha-methylstyrene, α,4-dimethylstyrene, tert-butylstyrene, o-chlorostyrene, 2-butenylnaphthalene, 4-tert-butoxystyrene, 3-isopropenylbiphenyl, 4-vinylpyridine, 2-vinylpyridine and isopropenylnaphthalene, 4-n-propylstyrene, isomeric mixtures and combinations thereof. These preferred vinyl aromatic monomers for the inversely tapered thermoplastic elastomer compositions of the present invention also include, but are not limited to, bio-sourced and / or bio-based unsubstituted and substituted vinyl aromatic monomers, protected functionalized unsubstituted and substituted vinyl aromatic monomers (including, but not limited to, hydrosilylated monomers and hydrosilane functional monomers), isomeric mixtures and combinations thereof. Substituted vinyl aromatic monomers having at least one substituent selected from C1-C18 vinyl, alkyl or alkoxy, cycloalkyl and / or aromatic groups are various compounds, including but not limited to: vinyl substituted styrene, alkyl substituted styrene, alkoxy substituted styrene, vinyl naphthalene, alkyl substituted vinyl naphthalene, 1,1-diphenylethylene, 1,4-diisopropenylbenzene, 1,4-bis(1-phenylvinyl)benzene, isomer mixtures and combinations thereof. The most preferred substituted vinyl aromatic monomers having at least one substituent to change the compatibility and / or reactivity with C1-C18 vinyl are those in which the substituent has at least one terminal and / or non-terminal vinyl group that increases the vinyl configuration unit without making the substituent susceptible to side reactions during polymerization.

[0075] In some embodiments of the method provided herein, the novel reverse tapered thermoplastic elastomer composition undergoes all or part of coupling to prepare branched and radial, linear triblock or multi-arm block copolymers. Partial coupling means that a portion of the polymer chain ends of all active anionic polymerizations are coupled with a coupling agent. The coupling agent ideally couples 2 to 30 anionic polymerized polymer chains (arms), but coupling agents capable of coupling more chains can also be used. Suitable coupling agents for all or part of the coupling steps include, but are not limited to, tin halides, silicon halides, functionalized tin compounds, functionalized silicon compounds such as silane compounds and functionalized oligomeric compounds, such as those listed in U.S. Patent No. 7,517,934. The entire disclosure of U.S. Patent No. 7,517,934 is incorporated herein by reference. Silicon tetrachloride, methyltrichlorosilane, dimethyldichlorosilane and tin tetrachloride are specific examples of suitable coupling agents, wherein silicon tetrachloride and dimethyldichlorosilane are particularly suitable for this application. Partial coupling is achieved by controlling the stoichiometric ratio of coupling agent to living polymer. Partial coupling can provide polymer blends with desired properties.

[0076] Preferred coupling agents for all or part of the coupling step include, but are not limited to, tin halides, silicon halides, tin alkoxides, silicon alkoxides, alkyl-substituted tin and silicon trihalides, alkyl-substituted tin and silicon dihalides, hexahalodisilanes, hexahalodisiloxanes, functionalized tin compounds, functionalized silicon compounds, alkoxysilane compounds, alkoxy-substituted silicon and tin halides, alkoxyalkylsilanes, epoxysilane compounds, amino and / or amine silane compounds, isocyanatosilane compounds, methacrylate silane compounds; acrylate silane compounds; sulfur silane compounds, fluorosilane compounds, fluoroalkylsilane compounds, sulfalkylsilane compounds, mercaptosilane compounds, sulfide silane compounds, sulfide tin compounds, and functionalized oligomeric compounds, such as those listed in U.S. Pat. Nos. 3,281,383, 7,517,934, and 8,883,927, multifunctional compounds, mixtures, or combinations of the foregoing compounds. The entire disclosure of U.S. Patent Nos. 3,281,383, 7,517,934 and 8,883,927 is incorporated herein by reference. Other suitable coupling agents include siloxanes, multifunctional epoxides, esters such as methyl benzoate compounds, epoxidized oils and polyolefinic compounds. Polyolefinic coupling agents are disclosed in, for example, U.S. Patent Nos. 3,985,830, 4,391,949 and 4,444,953 and Canadian Patent No. 716,645. Suitable polyolefinic coupling agents include divinylbenzene, preferably m-divinylbenzene. Functionalized silicon and tin compounds can be used to connect specific functional groups to the polymer chain of the novel modified diene copolymer, including but not limited to chloropropyltrialkoxysilane, trialkyltin chloride and trialkoxytin chloride, such as chloropropyltriethoxysilane, chloropropyltrimethoxysilane, trimethyltin chloride, trimethoxytin chloride, triethyltin chloride, triethoxytin chloride, trioctyltin chloride, trioctyloxytin chloride, etc. Coupling agent, a combination of coupling agents or a mixture of coupling agents can be added sequentially, partially, intermittently or continuously during polymerization to achieve polydispersity, functionality, asymmetry, etc. A preferred combination is to combine two silicon coupling agents such as silicon halides and silicon alkoxides. A more preferred combination is to combine silicon compounds and tin compounds such as silicon halides and tin alkoxides. The most preferred combination is to combine silicon compounds and functionalized oligomeric compounds. The most preferred combination is to combine silicon compounds, tin compounds and functionalized oligomeric compounds.

[0077] In other embodiments, the novel inversely tapered thermoplastic elastomer composition undergoes full or partial connection to connect polymer chains and prepare linear, branched or radial, multi-arm or grafted copolymers, which retain active properties and are capable of polymerizing remaining or new monomers to prepare miktoarm, hybrid and / or asymmetric novel inversely tapered thermoplastic elastomer compositions, which include at least one polymer chain (intramolecular) having at least one different feature such as composition, microstructure, size, vinyl configuration, etc. Partial connection refers to a portion of the polymer chain ends of all active anionic polymers being connected to a linker. The linker ideally connects 2-30 anionically polymerized polymer chains (number of arms), but a linker capable of connecting a greater number of chains may also be used. Suitable linking agents for all or part of the linking step include, but are not limited to, polyvinyl compounds such as 1,3-diisopropenylbenzene, 1,4-diisopropenylbenzene, 1,3,5-triisopropenylbenzene, 1,3-bis(1-phenylvinyl)benzene, 1,4-bis(1-phenylvinyl)benzene, 1,3,5-tri(1-phenylvinyl)benzene, 1,3-divinylbenzene, 1,4-divinylbenzene, 1,3,5-trivinylbenzene, and substituted polyvinyl compounds having at least one substituent such as alkyl, alkoxy, cycloalkyl, and cycloalkoxy, etc. Oligomeric polyvinyl compounds can be used as linking agents with high functionality.

[0078] When mixed with alkyl lithium initiators, organometallic compounds of different metals from Group IIa, Group IIb and Group IIIa, including magnesium, zinc and aluminum, can be used as polymerization rate regulators. Specific examples of suitable polymerization rate regulators are dibutyl magnesium, diethyl zinc, triethyl aluminum and combinations thereof. Polymerization rate regulators can be used to control the temperature profile of the polymerization. Polymerization rate regulators help control the polymerization step carried out in an isothermal mode within a pre-established residence time or in a quasi-adiabatic mode until the peak temperature.

[0079] In some embodiments of the methods provided herein, the novel inverse tapered thermoplastic elastomer composition is polymerized in a batch, programmed batch, and / or semi-batch process. Those skilled in the art will recognize that the synthesis of the described inverse tapered thermoplastic elastomer composition can be carried out in a reaction environment that includes a process operating at the temperature, solvent ratio, and stream flow rate required to achieve the described residence time and stoichiometric conditions.

[0080] application

[0081] Other aspects of the present invention provide compositions and articles made from the novel inversely tapered thermoplastic elastomer composition, reinforced materials made from mixtures of the novel inversely tapered thermoplastic elastomer composition and materials to be reinforced, and articles made from the reinforced materials. Other aspects of the present invention provide novel inversely tapered thermoplastic elastomer compositions, and blends of the novel inversely tapered thermoplastic elastomer compositions with other block copolymers, which have enhanced adhesion to specific substrates, and articles made from the adhesion-enhanced materials. For various asphalt, adhesive and sealant applications, the novel inversely tapered thermoplastic elastomer compositions achieve a better balance between processability and reinforcement performance. The novel inversely tapered thermoplastic elastomer compositions provide the above-mentioned applications with the advantages of easy processing, such as short dispersion time, low mixing temperature, low viscosity, and excellent storage stability; as well as better reinforcement advantages, such as high elastic response, a wide range of performance grades, high adhesion, higher filler loading capacity, and better high and low temperature property compromise. These advantages of processability and reinforcement make the novel inversely graded thermoplastic elastomer compositions suitable for meeting the requirements of a wide range of applications such as paving, roofing, shingles, waterproofing membranes, adhesive tapes and labels, contact and sprayable adhesives, and sealants.

[0082] In the desired commercial applications, some novel inversely tapered thermoplastic elastomer compositions provided herein are very suitable for use as adhesives and sealants, including pressure-sensitive adhesives, non-pressure-sensitive adhesives, hot melt adhesives, hot melt and solvent-based adhesives and sealants. The inversely tapered thermoplastic elastomer compositions can also be designed to be used as compatibilizers or reinforcing agents in asphalt and polymer blends. Asphalts that can benefit from the compatibilizers or reinforcing agents provided herein include those that are commonly used for paving, roofing and sealant applications. Paving applications include the enhancement of asphalt cement / adhesives used to make asphalt concrete for road construction, and the modification of materials for road repair, repair and maintenance, including chip sealing, resealing, resurfacing and recycling. Roofing applications include the enhancement of shingles, and the modification of materials for roof waterproofing, repair and maintenance. Certain types of inversely tapered thermoplastic elastomer compositions can also be used as reinforcing agents, viscosity modifiers, flow modifiers, processing aids and impact modifiers in rubber and plastics. Non-polar plastics are the type of plastics that can benefit from a reverse tapered thermoplastic elastomer composition.Non-polar plastics include, but are not limited to, polyolefins, polystyrene, and copolymers thereof.

[0083] Those skilled in the art will recognize that the optimal characteristics and properties of the inverse tapered thermoplastic elastomer composition will depend on the intended application. Several exemplary applications of the inverse tapered thermoplastic elastomer composition are provided below. These applications are provided only for illustrative purposes and are not intended to limit the scope of the present invention.

[0084] Asphalt reinforcement:

[0085] Bitumen modification with high molecular weight elastomers is generally used to prepare modified asphalt binders with properties superior to unmodified asphalt binders. The performance properties of asphalt products improved with the addition of polymers are: a) flexibility at low temperatures; b) resistance to flow and deformation at high temperatures; c) temperature sensitivity; d) tensile strength; e) modulus of stiffness at high temperatures; f) asphalt-aggregate adhesion; g) resistance to surface abrasion. Products that benefit from asphalt modification with polymers are pavement binders, seal coats, highway joint sealants, waterproof membranes, coatings, pipe mastics, pipe wraps and others.

[0086] Asphalt modification using elastomers based on monovinyl aromatic and conjugated diene monomers is complicated by the tendency of high molecular weight polymers to be immiscible with asphalt, and the limited phase stability leading to asphalt-polymer separation, which adversely affects the performance properties of the asphalt product. Phase stability is typically improved by crosslinking the asphalt-polymer blend or by increasing the compatibility of the polymer with the asphalt. High molecular weight polymers also adversely affect the processing characteristics of the modified asphalt binder by significantly increasing the melt viscosity of the asphalt-polymer blend. Modification of polymer composition and / or structure in the prior art has been used to improve processing characteristics and reduce the cost of asphalt-polymer blends, but generally adversely alters performance properties.

[0087] The inventors have found that the addition of the inversely tapered thermoplastic elastomer composition provided herein to asphalt maximizes processing characteristics without reducing the performance properties of the modified asphalt, compared to modified asphalts formulated with prior art copolymers. The inversely tapered thermoplastic elastomer composition of the present invention provides an asphalt blend having the following properties: lower melt viscosity and high fluidity; improved dispersibility and compatibility; higher blend stability; and good elastic and thermoplastic properties. It has also been found that the inversely tapered thermoplastic elastomer composition of the present invention can be used as a compatibilizer or reinforcing agent. Asphalts that can benefit from the compatibilizer or reinforcing agent provided herein include those commonly used in paving, roofing and sealant applications. Paving applications include the enhancement of asphalt cement / binders used to make asphalt concrete for road construction, and the modification of materials used for road repair, repair and maintenance, including chip sealing, resealing, resurfacing and recycling. Roofing applications include the enhancement of shingles, and the modification of materials used for roof waterproofing, repair and maintenance.

[0088] The inventors have also found that emulsions of asphalt previously modified with the inversely tapered thermoplastic elastomer composition of the present invention improve the adhesion of asphalt to aggregate particles when used for road repair, repair and maintenance. It has also been found that the compatibilizers or enhancers provided herein can be encapsulated and blended with commercially available block copolymers to improve the phase stability and processing characteristics of modified asphalt blends.

[0089] In countries such as the United States, modified asphalt is evaluated according to the standards of the American Association of State Highway and Transportation Officials (AASHTO), which rates asphalt according to performance grades (PG). The standards of the American Society for Testing and Materials (ASTM) are also used for asphalt evaluation. The properties evaluated in modified asphalt are, in particular, the following:

[0090] a) Ring and Ball Softening Point (RBSP), which can be measured according to ASTM D 36, indicates the temperature at which the asphalt softens and becomes unsuitable for the present application. The softening point or temperature is measured using a ring and ball instrument, also known as an R&B instrument.

[0091] b) Needle penetration at 25°C, which is a parameter related to the rigidity of the modified bitumen. Penetration can be measured according to ASTM D5 as the distance a weighted needle or cone will sink into the bitumen over a set period of time.

[0092] c) Brookfield viscosity, which is a property related to the stable steady-state flow of asphalt. Brookfield viscosity can be measured according to ASTM D4402.

[0093] d) Resilience is a property that measures the elasticity of asphalt materials. Resilience can be measured according to ASTM D 113.

[0094] e) Rutting Factor: G* / sinδ (where G* is the complex modulus and δ is the phase angle) at different temperatures can be used to determine the performance of modified asphalt at elevated temperatures. This factor indicates the pavement's tolerance to permanent deformation that may occur over time under repeated loading at elevated temperatures or when the pavement is subjected to loads much greater than the maximum allowed by the original design. Thus, a higher rutting factor value at elevated temperatures indicates that the asphalt can withstand greater deformation than a material with a lower rutting factor at the same test temperature. The rutting factor can be measured in accordance with AASHTO TP5.

[0095] f) Upper temperature limit. By measuring the rutting factor, the upper temperature limit can be determined according to the AASHTO standard. The upper temperature limit is related to the highest temperature at which the asphalt can maintain sufficient rigidity to resist rutting.

[0096] g) Lower temperature limit. By measuring the rutting factor, the lower temperature limit can be determined according to the AASHTO standard. The lower temperature limit is related to the lowest temperature at which the asphalt can remain flexible enough to resist thermal cracking.

[0097] h) Due to the above mentioned issues, phase separation is a key factor in modifying bitumen with elastomers. The phase separation index is measured as the T measured at the top and bottom surfaces of the cylindrical probe. RBSP The percentage difference between the two was made inside a sealed tube containing the formulated bitumen and aged for 48 hours at 163 °C in a vertical position without stirring and frozen at 30 °C.RBSP The percentage difference in provides a measure of the compatibility between the asphalt-rich phase and the polymer-rich phase in the asphalt / polymer blend.

[0098] Two specific applications where enhanced asphalt can be used are paving applications and roofing / waterproofing coating applications. In some cases when enhanced asphalt is used for paving applications, 0.5 to 8 parts, preferably 2 to 5 parts of the inversely tapered thermoplastic elastomer composition of the present invention can be mixed with 99.5 to 92 parts, preferably 98 to 95 parts of asphalt to improve its performance characteristics. In some cases when enhanced asphalt is used for roofing or waterproofing coating applications, 3 to 25 parts, preferably 6 to 16 parts of the inversely tapered thermoplastic elastomer composition of the present invention can be mixed with 97 to 75 parts, preferably 94 to 84 parts of asphalt to improve its performance characteristics. Suitable asphalts used together with the inversely tapered thermoplastic elastomer composition of the present invention include, but are not limited to, PG 64-22 asphalt or other asphalts widely used in paving and roofing applications, such as natural rock asphalt, lake asphalt, petroleum asphalt, gas-refined asphalt, cracked asphalt, and residual asphalt.

[0099] In some embodiments of the present invention, the much lower viscosity of the asphalt formulations prepared with the inversely tapered thermoplastic elastomer compositions provided herein, in addition to helping to improve dispersion into the asphalt, also facilitates the processing, handling and application of the modified asphalt blend by improving pumpability and / or reducing the energy required to apply the modified asphalt blend. This also means important cost reduction and a more environmentally friendly method. The high softening point temperature of the asphalt modified with the inversely tapered thermoplastic elastomer composition of the present invention should provide much better resistance to flow and deformation at high temperatures. Surprisingly, asphalt modified with the inversely tapered thermoplastic elastomer composition of the present invention and formulated with a low polymer content provides similar performance properties (T RBSP ) and lower viscosity. This also means important cost reductions and energy-saving processes.

[0100] In another embodiment of the present invention, asphalt and / or petroleum asphalt compositions formulated with fully coupled inversely tapered thermoplastic elastomer compositions having a linear structure (A-[A / B])-X-([B / A]-A) and / or coupled radial and / or multi-arm structures (A-[A / B])nX can provide improved performance properties, such as high softening point temperature (TRBSP), which means much better resistance to flow and deformation at high temperatures. Asphalt and / or petroleum asphalt compositions modified with the fully coupled inversely tapered thermoplastic elastomer compositions of the present invention can be formulated with low polymer content and can provide performance properties (i.e., TRBSP) and lower viscosity similar to asphalt and / or petroleum asphalt compositions modified with commercially available polymers of the prior art. This can also mean important cost reduction and energy-saving processes.

[0101] In some embodiments of the present invention, the inversely tapered thermoplastic elastomer composition provided herein can impart one or more of the following properties to the asphalt composition: a) a maximum application temperature of about 50 to 100°C, which is measured as the temperature at which the rutting factor or dynamic shear stiffness (G* / sinδ) takes a value of 1.0 KPa (measured according to AASHTO TP5); b) a T of about 40 to 110°C. RBSP (measured according to ASTM D36); c) an asphalt penetration of about 30 to 75 dmm at 25°C for paving applications (according to ASTM D5), or an asphalt penetration of about 50 to 100 for roofing and waterproofing applications; and d) a dynamic viscosity of about 500 to 3000 cP and desirably 1000 to 2000 cP at 135°C for paving applications, or a dynamic viscosity of about 1000 to 6000 cP and desirably 1500 to 4000 cP at 190°C for roofing and waterproofing applications (according to ASTM D4402).

[0102] Adhesives, Sealants and Coatings:

[0103] High molecular weight elastomers are usually formulated in blends that can be used as adhesives, sealants and coatings to provide a sufficient balance between bonding strength and adhesive properties in each application. Elastomers based on monovinyl aromatic and conjugated diene monomers are widely used as pressure-sensitive adhesives, spray and contact adhesives, panel and construction adhesives, sealants and coatings. Elastomers containing isoprene are preferred for hot melt pressure-sensitive adhesives because they can be easily tackified at low cost. Elastomers containing butadiene are generally preferred for construction or laminating adhesives because they can provide stiffness and bond strength. Hydrogenated forms of these elastomers are preferred for sealants because they have higher weather resistance. The performance properties required for successfully formulating adhesives, sealants and coating products with elastomers are as follows: a) compatibility of tackifying resins with elastomers; b) continuous elastomeric phase morphology for bonding strength and shear resistance; c) soft and low modulus elastomers for viscosity development and energy dissipation; d) suitable tackifying resins that increase the glass transition temperature (Tg) of the rubber phase of the elastomer to increase the dissipation of strain energy.

[0104] The high molecular weight polymers of the prior art adversely affect the processing characteristics of adhesives, sealants and coating formulations by significantly increasing the melt and solution viscosity of these blends. Modification of polymer compositions and / or structures in the prior art has been used to improve processing characteristics and reduce the formulation costs of adhesives, sealants and coating applications, but generally adversely changes performance properties. In the required commercial applications, some novel reverse tapered thermoplastic elastomer compositions provided herein are very suitable for use as adhesives, sealants and coatings, including pressure-sensitive adhesives, non-pressure-sensitive adhesives, hot melt adhesives, hot melt and solvent-based adhesives, sealants and coatings. The development of low melt viscosity and low solution viscosity is particularly important for pressure-sensitive adhesives, hot melt adhesives and solvent-based adhesives. The inventors have found that adding novel reverse tapered thermoplastic elastomer compositions provides outstanding processing characteristics for formulations without significantly affecting the required performance properties of adhesives, sealants and coating products. It is worth noting that the hot melt pressure-sensitive adhesives prepared with these novel reverse tapered thermoplastic elastomers show higher compatibility with various resins and excellent bond strength and extremely high shear resistance. It has also been discovered that the compatibilizers or reinforcing agents provided herein can be encapsulated and blended with commercially available block copolymers to improve the phase stability and processing characteristics of adhesive blends.

[0105] In some such applications, about 10 to 40 parts by weight, desirably 15 to 30 parts by weight, and more desirably 18 to 25 parts by weight of the novel inversely tapered thermoplastic elastomer composition or a mixture thereof with a commercially available block copolymer is mixed with other conventional adhesive formulation components / additives such as tackifying resins; plasticizers; coupling agents; crosslinking agents; photoinitiators; fillers; processing aids; stabilizers and antioxidants; to impart improved properties to such compositions compared to adhesives formulated with prior art elastomers (as a suitable control). Examples of suitable tackifiers include resins with high and low softening points that are compatible with polymers. These resins include hydrogenated resins, rosin esters, polyterpene resins, terpene phenol resins, indene-coumarone resins, and aliphatic hydrocarbon resins. In some exemplary embodiments, the amount of tackifying resin in the composition is about 40% to 65% by weight. Plasticizers, commonly referred to as extender oils, include mineral oils, paraffin oils, and naphthenic oils. In some exemplary embodiments, the amount of plasticizer in the composition is about 15% to 35% by weight. Antioxidants can be used to inhibit thermal oxidation and UV oxidation processes, and are usually added to the adhesive composition in an amount of about 0.05% to 3% by weight. Examples of antioxidants include phenolic compounds, phosphites, amines and thio compounds. Some examples of commercially available adhesive components / additives are listed in Table A below.

[0106] In another embodiment of the present invention, adhesive compositions formulated with fully coupled inversely tapered thermoplastic elastomer compositions having a linear structure (A-[A / B])-X-([B / A]-A) and / or coupled radial and / or multi-arm structures (A-[A / B])nX can provide improved performance properties, such as high softening point temperature (TRBSP) and high shear adhesive failure temperature (SAFT), which means high heat resistance and much better resistance to flow and deformation at high temperatures. Adhesive compositions having the fully coupled inversely tapered thermoplastic elastomer compositions of the present invention can be formulated with lower polymer content and can provide similar performance properties (i.e., TRBSP) and lower viscosity to adhesive compositions formulated with prior art commercially available polymers. This can also mean important cost reduction and energy-saving processes.

[0107] Table A

[0108]

[0109] The Sylvalite, Sylvares and Wingtack products in Table A are available from Arizona Chemical. Foral, Pentalyn, Permalyn, Piccotac and Eastotac products are available from Eastman / Hercules. Shellflex products are available from Shell. Primol 352 is available from Esso or ExxonMobil. RPO and P.Oil products are available from IPISA or Ingenieríay Procesos Industriales, SA. Irganox products are available from Ciba Specialty Chemicals, Inc. Anox, Alkanox and Lowinox products are available from Great Lakes Chemical Corporation. Ultranox and Weston products are available from GE Specialty Chemicals.

[0110] The novel inversely tapered thermoplastic elastomer composition provides adhesive, sealant and coating applications, which have reactive sites that are easily modified and crosslinkable portions that allow photocuring, heat curing and chemical curing crosslinking. The reactive sites can directly crosslink the novel inversely tapered thermoplastic elastomer composition and / or can be suitable for further functionalization, which promotes crosslinking under more suitable mild conditions during application. The novel reactive adhesive, sealant and coating compositions containing the inversely tapered thermoplastic elastomer composition of the present invention can be prepared and cured by any suitable method known in the art, such as those described in U.S. Patent Nos.: 8,703,860; 7,799,884; 7,432,037; 6,926,959, 5,804,663 and 4,306,049; and EU Patent No. 0097307, which are incorporated herein by reference in their entirety. Reinforced materials comprising inversely tapered thermoplastic elastomer compositions or polymer blends and mixtures containing inversely tapered thermoplastic elastomers achieve suitable compatibility and reactivity and improve the balance between processability and reinforcement properties for various applications such as adhesives, sealants and coatings. The novel inversely tapered thermoplastic elastomer compositions and polymer blends thereof and mixtures with other suitable polymers can be used in pressure-sensitive and non-pressure-sensitive, hot melt solvent-based formulations for tape, labeling, packaging, construction and positioning adhesive end-use applications, including solvent-based adhesives and sealants. The novel inversely tapered thermoplastic elastomer compositions can be used in low viscosity and reactive hot melt adhesive compositions, particularly for sprayable and contact adhesives with high heat resistance, low energy processability and low volatile organic compound (VOC) emissions relative to solvent-based formulations. More specifically, the novel inversely tapered thermoplastic elastomer compositions provide, for adhesive, sealant and coating applications: tailored compatibility with formulation ingredients, easily modified reactive sites and crosslinkable moieties that allow photo-, thermal- and chemical-cure crosslinking; easy processing advantages, such as low mixing temperatures and low application temperatures; and good reinforcement advantages, such as high heat resistance, high cohesive strength and shear resistance, high tack and peel resistance.

[0111] The novel adhesive composition comprising the inversely tapered thermoplastic elastomer of the present invention may be radiation curable and suitable for a variety of end uses, including but not limited to pressure sensitive adhesives for high performance tapes and labels, such as cold storage grade tapes and labels and automotive adhesives; and adhesive applications for wet surfaces, such as medical applications. The novel adhesive composition of the present invention may further comprise at least one second polymer in combination with the inversely tapered thermoplastic elastomer composition. Examples of useful commercially available second block copolymers include but are not limited to and H block copolymer, D and G series block copolymers, Sol T block copolymer, Block copolymers and others. The novel inversely tapered thermoplastic elastomer composition and the second block copolymer may have increased vinyl configuration units in at least one conjugated diene homopolymer or copolymer block or segment to be more radiation sensitive and curable to further contribute to adhesive properties, such as high heat resistance and high shear resistance. Preferred second block copolymers for novel adhesive compositions containing the inversely tapered thermoplastic elastomers of the present invention include at least one styrene-isoprene-styrene (SIS) block copolymer having a styrene content of less than about 25% by weight to improve adhesion while maintaining high heat resistance, such as high shear adhesive failure temperature (SAFT) and / or high ring and ball softening point temperature (TRBSP).

[0112] Radiation-curable novel adhesives, sealants and coating compositions containing the inversely tapered thermoplastic elastomers of the present invention can be formulated with suitable photoinitiators to generate crosslinking and / or polymerization initiating free radicals when the photoinitiator is irradiated with a light source. Suitable photoinitiators include, but are not limited to, photoinitiators classified as photo-cleavage photoinitiators and hydrogen-abstracting photoinitiators according to the pathways for generating effective initiating free radicals. Hydrogen donor sources for hydrogen-abstracting photoinitiators include amines, thiols, unsaturated rubbers such as polybutadiene or polyisoprene and alcohols. In radiation-curable compositions, crosslinking occurs by exposure to ultraviolet radiation and / or ionizing radiation generated by the emission of electrons or highly accelerated nuclear particles such as neutrons, alpha particles, etc. The light-absorbing chromophores used in the photoinitiator system are selected to match the emission band of the light source as closely as possible. The chromophores present in the photoinitiator make them sensitive to ultraviolet radiation and / or visible radiation, so that they can initiate and / or participate in crosslinking when exposed to such light sources. Suitable photoinitiators containing chromophore compounds that undergo hydrogen abstraction photochemistry include, but are not limited to, benzophenones and related aromatic ketones, such as xanthone, thioxanthone, 4,4'-bis(N,N'-dimethylamino)benzophenone, benzil, quinone, quinoline, anthraquinone, fluorene, acetophenone, xanthone, phenanthrene and fluorenone. Suitable photoinitiators can be used in an amount of about 0.05% to about 10% by weight of the formulated composition, preferably about 0.2% to about 3% by weight, and more preferably about 0.5% to about 1.5% by weight. The specific amount of suitable photoinitiators that can be used in the formulation depends on the polymer composition, as well as the radiation source, the amount of radiation received, the line speed, and the thickness of the adhesive, sealant or coating composition on the substrate.

[0113] In another embodiment, the adhesive, sealant or coating composition of the present invention can be crosslinked by ultraviolet (UV) or electron beam (EB) radiation in air or nitrogen atmosphere by exposure to ultraviolet radiation with a wavelength of 180-400nm, preferably 200-390nm, sufficient to achieve the desired amount of crosslinking time. It is important to match the UV light emission wavelength with the absorption wavelength of the photoinitiator. The exposure time depends on the nature and intensity of the radiation, the specific ultraviolet light initiator and the amount used, the polymer system, the thickness of the film, environmental factors and the distance between the radiation source and the adhesive film. The irradiation can be carried out at any temperature, and most suitably at room temperature. For UV curable compositions, one or more photoactive initiators and / or photoactive coupling agents can be added to the adhesive, sealant or coating composition of the present invention. In order to cure the adhesive, sealant or coating composition of the present invention, an actinic radiation source of sufficient energy can be used to generate free radicals when incident on the selected specific photoinitiator for the composition. The preferred wavelength range of the photoinitiator is 400 to 250nm. Suitable photocuring methods are disclosed in U.S. Pat. Nos. 4,181,752 and 4,329,384, which are incorporated herein by reference. α-cleavage type photoinitiators are known in the art. Commercial examples include, but are not limited to, Irgacure 184 and Darocur 1173. Preferred free radical type photoinitiators include, but are not limited to, acylphosphine oxides, bisacryloylphosphine oxides, combinations and mixtures thereof. Available commercial examples include, but are not limited to 819, 1800 and 1850; and Lucirin TPO. For electron beam (EB) radiation curing, a photoactive coupling agent may not be required to crosslink the adhesive, sealant or coating composition containing the inversely tapered thermoplastic elastomer of the present invention. The composition of the present invention can also be cured by electron beam (EB) radiation without the use of a photoinitiator. The dosage required to crosslink the composition may vary depending on the specific composition, but is generally from about 1 to about 20 Mrads, preferably from about 2 to about 10 Mrads. Suitable methods for electron beam (EB) curing can be found in U.S. Patent No. 4,533,566, which is incorporated herein by reference. The radiation energy density and therefore the line speed for adequate curing depends on the composition, and more importantly, on the thickness of the adhesive film being cured.

[0114] The radiation-curable hot melt adhesive, sealant and coating composition of the present invention, which contains a novel reverse tapered thermoplastic elastomer composition and / or a second block copolymer with an increased vinyl configuration unit in at least one conjugated diene homopolymer or copolymer block or segment, is even more radiation-sensitive and curable to further contribute to enhanced performance such as high heat resistance and high shear resistance, and is also included in at least one conventional ingredient in a typical formulation, such as a tackifying resin, an extender oil and / or a plasticizer, a petroleum-derived wax, an antioxidant, a photosensitizer (in the case of UV radiation curing) and an optionally present resin compatible with the vinyl aromatic block or segment, the composition can be cured by exposure to high-energy ionizing radiation such as electron beam radiation or by UV radiation. The crosslinking reaction is conveniently carried out at room temperature, but it can be carried out at a reduced or elevated temperature, under an inert atmosphere, to prevent interference with the crosslinking of the block copolymer at the exposed surface, or by irradiation through a peeling paper or substrate to protect the exposed surface. Exposure to UV radiation can be carried out by any known method. A suitable method is to expose the sample to UV radiation by passing it under a UV source at a certain speed, in a layer obtained from a hot melt or in a layer obtained by solvent coating. Preferred uses of the formulations of the present invention are the preparation of pressure-sensitive adhesive tapes and the manufacture of labels. The backing sheet may be a plastic film, paper or any other suitable material, and the tape may include various other layers or coatings used in the manufacture of pressure-sensitive adhesive tapes, such as primers, release coatings, etc.

[0115] In another aspect of the present invention, the novel inversely tapered thermoplastic elastomer composition can be used for radiation-cured hot melt pressure-sensitive adhesives, radiation-cured sealants and radiation-cured coating compositions, and articles comprising the cured adhesives, sealants and / or coating compositions. Suitable photoinitiators can be used to prepare pressure-sensitive hot melt adhesives, sealants and coating compositions, including but not limited to decorative wear-resistant coatings, lacquers, fiber-reinforced composites, microelectronic packaging, chip mounting adhesives, optical fiber coatings, molding compounds, UV-cured structural resins, etc. Suitable base resins for preparing the adhesives, sealants and coating compositions of the present invention are well known to those skilled in the art. The adhesives, sealants and coating compositions of the present invention can be formulated with liquid or solid ethylenically unsaturated systems, such as acrylates, methacrylates, maleimides, styrenes, maleates, fumarates, unsaturated polyester resins, alkyl resins, polyisoprene, polybutadiene and thiol-ene compositions.

[0116] Other aspects of the present invention provide a reinforcing material composition comprising a novel hot melt adhesive, sealant or coating composition containing a reverse tapered thermoplastic elastomer of the present invention, and an article made of the reinforcing material composition. In one embodiment, the article comprises a novel hot melt adhesive, sealant or coating composition and a substrate. In another embodiment, the substrate comprises a plastic film, an elastomeric fiber, a nonwoven material, a packaging material or a construction material, such as: a shoe sole material, a furniture material and a binding material. The article of the present invention includes but is not limited to disposable nonwoven materials such as, sanitary pads and disposable elastic products such as, diapers, and pressure-sensitive adhesive products such as, repositionable / removable tapes and labels, low temperature / freezing temperature tapes and labels and automotive protective films. In another embodiment, the novel hot melt adhesive of the present invention can also be used as a building adhesive, such as for the manufacture of disposable articles, is particularly suitable for elastic connection applications, and can be advantageously used for pressure-sensitive terminal applications, such as label and tape applications, particularly at low temperature / freezing temperatures. Therefore, the novel hot melt adhesive of the present invention is particularly useful for the preparation of elastic nonwoven materials and for the manufacture of baby diapers, training pants, adult incontinence briefs or underwear, etc. Nonwoven materials are used commercially in disposable articles such as diapers, adult incontinence products, and sanitary napkins.

[0117] The present invention will be further described by reference to the following examples, which are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0118] Example

[0119] Example 1

[0120] Preparation of reverse tapered thermoplastic elastomer (CTTE)

[0121] In Example 1, several novel inverse tapered thermoplastic elastomers (CTTE 1-19) were prepared according to the claimed process. Polymers CTTE 1-14 and 17 are (A-[A / B])nX block copolymers, wherein the A-[A / B] diblock before coupling consists of a monovinyl aromatic homopolymer block A block which is a polystyrene block (PS) and an inverse tapered copolymer block [A / B] which is a styrene / butadiene copolymer block, which after coupling forms an [A / B]-X-[B / A] midblock having terminal regions rich in styrene units and a central region rich in butadiene units. CTTE 15, 16, 18 and 19 are polymers having only an inverse tapered copolymer block [A / B] of styrene / butadiene, which were prepared to illustrate the monomer distribution of the midblock copolymer chain before coupling.

[0122] Through GPC, 1The novel inverse tapered thermoplastic elastomer (CTTE) compositions were characterized by H NMR and DSC methods to determine: molecular weight average and molecular weight distribution properties, such as peak molecular weight (Mp), weight average molecular weight (Mw), and diblock to coupling ratio for linear diblock and coupled modes; microstructural properties, such as total styrene, block styrene, and vinyl A / B block content; and glass transition temperature (Tg) of the A / B inverse tapered copolymer blocks. In addition, calculations of midblock styrene and midblock blockiness were performed following the method used in US Patent Application US2003 / 0176582A1 published on September 18, 2003 by KRATON Polymers U.S. LLC and Bening et al. for characterizing the polymer midblock or "B" block as Calc. Mid PSC and Calc. Mid Blocky. Tables 1-2 list the analytical characterization results, and Table 3 lists the polymerization conditions for CTTE 1-19. The following describes the general procedure for preparing these novel inverse tapered thermoplastic elastomers (CTTEs) and controlling the monomer distribution in the anionic copolymerization of 1,3-butadiene (B) and styrene (S) in the presence of ditetrahydrofurylpropane (DTHFP) as a suitable polar modifier and randomizer for the styrene / butadiene [S / B] inverse tapered copolymer blocks. The abbreviations used for the polymerization conditions in Table 3 below are defined as follows: CHx = cyclohexane; STY = styrene; and BD = 1,3-butadiene. For the novel inverse tapered thermoplastic elastomers CTTE 1-14 and 17, silicon tetrachloride (SiCl4) was used as a coupling agent.

[0123] The novel inverse tapered thermoplastic elastomer (CTTE 1-19) compositions of the present invention are prepared in accordance with the teachings of the present invention in a 5.3 liter reactor system operated in batch and / or semi-batch mode under an inert nitrogen atmosphere. Just prior to addition to the reactor system, the solvent and monomers are fully purified by passing through a set of columns filled with alumina and molecular sieves to reduce their moisture content to a maximum of 5 ppm. For the first polymerization step, an appropriate amount of purified solvent (CHx) is added to the reactor and heated to an initial reaction temperature (Ti) of about 60°C to about 65°C. Once Ti is reached, a suitable polar modifier (randomizer) such as ditetrahydrofurylpropane (DTHFP) is added to the reactor, followed by a first addition of monovinyl aromatic monomer (first STY) of about 0 to about 17.5 wt% of the total monomer mixture. For CTTE 15, 16, 18 and 19, in order to prepare separate styrene / butadiene inverse tapered copolymer blocks to be polymerized by 1H NMR directly analyzes the midblock styrene, midblock blockiness, and monomer distribution along the copolymer chain of the [A / B] reverse tapered copolymer block without the first styrene monomer addition and without the calculations required to eliminate the interference of the monovinyl aromatic homopolymer block A (PS block) in CTTE 1-14 and 17, which is achieved by taking aliquots throughout the copolymerization process and then performing NMR characterization. The reaction mixture is stabilized at Ti, and then n-butyl lithium or another suitable initiator is added directly to the reactor mixture containing at least the amount of polar modifier required to effectively initiate anionic polymerization of the living polystyrene block in a suitable solvent solution. The amount of initiator is stoichiometrically calculated as described in the literature to form a single block with the desired molecular weight and to compensate for residual impurities. The first polymerization step is then allowed to proceed adiabatically until complete conversion to form a monovinyl aromatic homopolymer block A with a peak molecular weight Mp of about the target value of about 10,000.

[0124] For the second polymerization step, the addition of the two monomers is started simultaneously, and the second addition of monovinyl aromatic monomer (second STY) of about 7.5 wt% to about 9.1 wt% of the total monomer mixture is quickly added to the reactor at a specified dosage rate within a predetermined dosage time of about 1 minute, and the conjugated diene monomer (BD) of about 75.0 wt% to about 90.9 wt% of the total monomer mixture is slowly added to the reactor at a specified dosage rate within a predetermined dosage time of about 4 minutes to about 11 minutes. The addition of these monomers is carried out in a programmed batch and / or semi-batch mode, and the amount of polar modifier (randomizer) is adjusted from about 0.002 wt% to about 0.013 wt% of the total reaction mixture to promote the formation of a statistically distributed tapered S / B copolymer block with gradual changes in copolymer chain composition and vinyl microstructure (1,2-addition). The second polymerization step is then carried out adiabatically until complete conversion and the final peak temperature (Tp) is increased from about 100°C to about 105°C, thereby forming a reverse tapered copolymer [A / B] block and thereby obtaining a living reverse tapered A-[A / B] diblock copolymer having a peak molecular weight Mp of a target value of about 104,000 to about 122,000.

[0125] Finally, a sufficient amount of a suitable coupling agent, such as silicon tetrachloride (SiCl4), from about 0.003 to about 0.008 of the total reaction mixture is added to the reactor to partially couple the active inverse tapered A-[A / B] diblock copolymer to obtain the desired ratio of uncoupled linear diblock A-[A / B] to the coupled radial (A-[A / B])nX inverse tapered thermoplastic elastomer composition of the present invention, where X is the residual portion (Si) of the coupling reaction process. The remaining active polymer chains are terminated by adding a 10 mol% excess of a suitable alcohol to the final reaction mixture over the stoichiometric amount.

[0126] Tables 1 and 2 list the analytical characterization results of the novel inversely tapered thermoplastic elastomer compositions CTTE 1-19. All average molecular weights (Mp and Mw) are given in units of 1000 (k) and are calculated by GPC relative to polystyrene standards. The peak average molecular weight Mp of the monovinyl aromatic homopolymer block A or polystyrene block of CTTE 1-14 and 17 is about 9.5 kg / mol to about 11 kg / mol. The peak average molecular weight Mp of the A-[A / B] diblock copolymer or S-[S / B] styrene-butadiene diblock copolymer of CTTE 1-14 and 17 is about 104 kg / mol to about 122 kg / mol. The peak average molecular weight Mp of the [A / B] inversely tapered copolymer or [S / B] styrene-butadiene copolymer of CTTE 15, 16, 18 and 19 is about 94 kg / mol to about 108 kg / mol. The ratio of the coupled radial (A-[A / B])nX to the Mp of the uncoupled linear diblock A-[A / B] of CTTE 1-14 and 17 is about 3.3 to about 3.5. The weight average molecular weight Mw of CTTE 1-14 and 17 is about 178 kg / mol to about 267 kg / mol. The ratio of the uncoupled linear diblock A-[A / B] to the coupled radial (A-[A / B])nX of CTTE 1-14 and 17 is about 0.6 to about 2.8, which is the coupling efficiency determined based on the GPC area. The vinyl [A / B] block content of CTTE 1-19 is about 13.7 wt% to about 33.0 wt% based on the total butadiene units. The glass transition temperature of the [A / B] reverse tapered copolymer block of CTTE 6, 9 and 14-19 is about -82.0 to about -71.9°C. The contents determined by NMR in CTTE 1-14 and 17 are: total styrene from about 23.2 wt% to about 25.4 wt% based on the total copolymer; block styrene from about 68.8 wt% to about 83.6 wt% based on the total styrene units; mid-block styrene from about 7.9 wt% to about 10.7 wt% based on the mid-block copolymer, and mid-block blockiness from about 12.1 wt% to about 55.1 wt% based on the mid-block styrene units.

[0127] Figure 1 , Figure 2 , Figure 3 and Figure 4 The monomer distribution in the [A / B] midblock prior to coupling the inventive inverse tapered block copolymers CTTE 14, 16, 17, and 19 is depicted by taking aliquots throughout the copolymerization process and then performing NMR characterization. For CTTE 16 and 19, to isolate the styrene / butadiene inverse tapered copolymer blocks and by 1 H NMR directly analyzes the monomer distribution along the copolymer chain in the [A / B] midblock segment without performing a calculation to deduct the monovinyl aromatic homopolymer block A (PS block) in CTTE 14 and 17, and without performing a first styrene monomer addition. The calculation of the monomer distribution in CTTE 14 and 17 follows the method used in U.S. patent application US2003 / 0176582 A1 published on September 18, 2003 by KRATON Polymers US LLC and Bening et al. for characterizing the polymer midblock or "B" block.

[0128] Figure 1 and Figure 2It is clearly shown that the cumulative composition of the styrene monomers introduced into the [A / B] mid-block segments of CTTE 14 and 16 gradually decreases with increasing conversion of the butadiene / styrene mid-block polymerization. After coupling, the [A / B] mid-block segments form a complete [A / B]-X-[B / A] mid-block having terminal regions rich in styrene monomer units (low butadiene / styrene cumulative ratio) and a central region rich in butadiene monomer units (high butadiene / styrene cumulative ratio), which is exactly the opposite of the controlled distribution composition of the prior art. This is a surprising and unexpected result considering the fact that relatively small amounts of styrene monomers (about 10 wt% of the monomer mixture) are present during the copolymerization of the mid-block segments and sufficient amounts of polar modifiers (randomizers) for preparing the intermediate vinyl styrene / butadiene copolymers (about 30 wt% vinyl) are used in these copolymerizations. In addition, the inversely tapered A-[A / B]-X-[B / A]-A thermoplastic elastomer compositions of the present invention have a unique combination of high styrene (low butadiene / styrene ratio) and high vinyl at the terminal regions of the complete [A / B]-X-[B / A] styrene / butadiene midblock near the interface of the monovinyl aromatic homopolymer block A or the polystyrene block. It is noteworthy that low levels of midblock blockiness can be obtained even though the terminal regions of the styrene / butadiene midblock are relatively rich in styrene (low butadiene / styrene cumulative ratio). In addition, it is shown that the incorporation of styrene into the inversely tapered [A / B] midblock segments depends not only on the amount of styrene monomer and randomizer, but also on the temperature profile of the copolymerization and the dosing time of the monomers. Figure 2 and Figure 3 It is shown that the incorporation of styrene into the copolymer chain of the [A / B] mid-block of CTTE 16 gradually decreases in response to longer dosing times of the butadiene monomer. Figure 4 It is shown that when the amount of polar modifier (randomizer) is relatively small (lower vinyl), more significant changes in styrene incorporation of the [A / B] midblock segment between CTTE 17 and CTTE 19 occur in response to changes in butadiene monomer dosage time.

[0129] Table 1

[0130] Reverse tapered thermoplastic elastomer composition

[0131]

[0132] a Coupling efficiency ratio based on cumulative GPC area % relative to the molecular weight average of PS standards;

[0133] b RMN 1H300MHz, vinyl based on total butadiene units (wt%);

[0134] c Glass transition temperature (inflection point) measured by DSC at 10°C / min.

[0135] Table 2

[0136] NMR results of reverse tapered thermoplastic elastomer

[0137]

[0138] a RMN 1 H300 MHz, total styrene based on total copolymer (wt %);

[0139] b RMN 1 H300MHz, block styrene based on total styrene units (wt%);

[0140] c Midblock styrene (wt %) calculated based on midblock copolymer;

[0141] d Midblock blockiness (wt%) calculated based on midblock styrene units.

[0142] Table 3

[0143] Reverse tapered thermoplastic elastomer method

[0144]

[0145] a wt% of total reaction mixture

[0146] b wt% of total monomer mixture

[0147] One embodiment of the present invention is a method for preparing a reverse tapered thermoplastic elastomer composition, the method comprising: adding a solvent, a polar modifier or a combination of multiple polar modifiers, and a monovinyl aromatic monomer to a reactor to form an initial reaction mixture, wherein the amount of polar modifier in the initial reaction mixture is less than 10 wt %; adding an organolithium initiator compound to the reactor and anionically polymerizing the monomer to form a monovinyl aromatic homopolymer block A having a peak molecular weight of at least 5,000; adding additional monovinyl aromatic monomer, and simultaneously starting to dose a conjugated diene monomer into the reactor at a predetermined dosage rate for a predetermined time, and copolymerizing to form a reverse tapered copolymer block A / B having a vinyl content of at least 15 wt % based on the amount of conjugated diene units in the diblock copolymer, and obtaining a reverse tapered copolymer block A / B having a peak molecular weight of 20,000 to 250,000. and adding a coupling agent or a combination of coupling agents to partially couple the reverse tapered diblock AA / B copolymer to form a block copolymer, the block copolymer being a linear triblock copolymer, a multi-arm coupled block copolymer, or a mixture thereof; wherein the solvent, polar modifier, conjugated diene monomer, and monovinyl aromatic monomer comprise a total reaction mixture, wherein the amount of polar modifier is less than 5 wt % of the total reaction mixture, wherein the peak molecular weight of the linear triblock copolymer is at least about 1.5 times the peak molecular weight of the reverse tapered diblock AA / B copolymer, wherein the peak molecular weight of the multi-arm coupled block copolymer is at least about 2.5 times the peak molecular weight of the reverse tapered diblock AA / B copolymer, and wherein the ratio of reverse tapered diblock AA / B copolymer to block copolymer in the reverse tapered thermoplastic elastomer composition is from about 1:5 to about 5:1.

[0148] One embodiment of the present invention based on Example 1 and Table 3 is a method for preparing a reverse tapered thermoplastic elastomer in a batch or semi-batch mode, the method comprising:

[0149] preferably and optionally purifying the solvent and monomers to reduce their moisture content to a maximum of 50 ppm, preferably less than 25 ppm, and more preferably less than 5 ppm;

[0150] Loading a solvent into the reactor and heating the solvent to an initial reaction temperature (Ti) of 50°C to 75°C, possibly 55°C to 70°C, preferably 55°C to 70°C, and more preferably 60°C to 66°C, the solvent being greater than 75 wt% of the total reaction mixture, preferably 80 wt% to 90 wt%, more preferably 84 wt% to 90 wt%, and most preferably 86 wt% to 89 wt%, with a typical value of 86 wt% to 88 wt%, wherein the solvent is preferably cyclohexane;

[0151] Preferably, a suitable polar modifier is added to the reactor, the polar modifier is preferably ditetrahydrofurylpropane (DTHFP) or tetrahydrofuran (THF), and more preferably DTHFP;

[0152] Adding a monovinyl aromatic monomer, preferably styrene, to the reactor, typically 15 to 20 wt %, preferably 16 to 19 wt %, and more preferably 17 to 18 wt %, and most preferably 17.5 wt % of the total monomer mixture;

[0153] Preferably and optionally the solvent, polar modifier and monovinyl aromatic monomer are stabilized at a temperature Ti ± 10°C, preferably ± 5°C, and more preferably ± 2°C, and most preferably stabilized at Ti;

[0154] adding a lithium-based initiator, preferably n-butyllithium, in a suitable solvent solution to the reactor mixture, preferably wherein the amount of said initiator is stoichiometrically calculated to form a single block and to compensate for impurities;

[0155] The reaction is preferably and optionally carried out to complete conversion, preferably to at least 90% conversion, more preferably to 95% or more conversion, to form monovinyl aromatic homopolymer blocks A, the monovinyl aromatic homopolymer blocks A optionally having a peak molecular weight Mp of 5 to 15 kg / mol, preferably having a peak molecular weight of 8 to 12 kg / mol, and more preferably having a peak molecular weight of 10 to 11 kg / mol;

[0156] preferably adding a second addition of monovinyl aromatic monomer, preferably styrene, to the reactor, typically in an amount of 5 to 15 wt %, preferably 6 to 12 wt %, more preferably 7 to 9.5 wt %, and most preferably 7.5 to 9.1 wt %, and preferably 7.5 wt % of the total monomer mixture, over a period of 5 minutes, preferably less than 2 minutes;

[0157] Adding conjugated diene monomer B to the reactor, preferably without initial addition of conjugated diene monomer, preferably without waiting time after initial addition of conjugated diene, wherein the total amount of conjugated diene monomer added is greater than 55wt% of the total monomer mixture, typically 60wt% to 90wt%, usually 65wt% to 85wt%, preferably 70wt% to 80wt%, and preferably 75wt% of the total monomer mixture,

[0158] wherein the conjugated diene monomer is added at a dosage rate of 20 to 75 g / min, usually at a dosage rate of 30 to 70 g / min, usually at a dosage rate of 45 to 68 g / min, usually at a dosage rate of 47 to 67 g / min, preferably at a dosage rate of 54 to 67 g / min,

[0159] The addition time of the conjugated diene monomer is shorter than 90 minutes, 80 minutes, 70 minutes, 60 minutes, 50 minutes, 40 minutes, 30 minutes, 20 minutes or 15 minutes, and is generally less than 13 minutes, and is preferably added within a time period of 4 to 12 minutes, more preferably within 5 to 11 minutes, preferably wherein the conjugated diene is butadiene or isoprene, and more preferably 1,3-butadiene;

[0160] The reaction is carried out to at least 80% conversion, usually to more than 90% conversion, preferably to at least 98% conversion, more preferably to at least 99% conversion, and most preferably to complete conversion, preferably to a final peak temperature Tp of more than 100°C, more preferably 103 to 106°C or 103 to 105°C, thereby forming a reverse tapered copolymer block A / B and obtaining a living reverse tapered diblock AA / B copolymer, the reaction is preferably carried out in a single reactor, and preferably does not require the use of 2 reactors, typically wherein the reverse tapered diblock AA / B copolymer has a peak molecular weight of 70 kg / mol to 140 kg / mol, preferably wherein the reverse tapered diblock AA / B copolymer has a peak molecular weight of 80 kg / mol to 130 kg / mol, and more preferably wherein the reverse tapered diblock AA / B copolymer has a peak molecular weight of 90 kg / mol to 125 kg / mol, and a range of 100 kg / mol to 115 kg / mol is most typical.

[0161] The optional but preferred next step, which is preferably carried out in the same reactor without transfer to a second reactor, comprises:

[0162] A suitable coupling agent or a combination of coupling agents, preferably silicon tetrachloride, is added to the reactor to partially couple the active inverse tapered diblock AA / B copolymer to form an inverse tapered thermoplastic elastomer, wherein the amount of the coupling agent is 0.0020 to 0.0100 wt %, typically 0.0025 to 0.0085 wt %, and preferably 0.0030 to 0.0080 wt %, of the total reaction mixture.

[0163] Typically wherein the ratio of uncoupled linear diblock A-[A / B] to coupled radial (A-[A / B])nX inversely tapered thermoplastic elastomer is from 0.2 to 5.0, preferably wherein the ratio is from 0.3 to 4.0, and more preferably wherein the ratio is from 0.5 to 3.0 or 0.4 to 3.0,

[0164] Typically, the weight average molecular weight Mw of the inversely tapered thermoplastic elastomer is 80 to 300 kg / mol, typically 85 to 275 kg / mol, preferably 90 to 270 kg / mol, and more preferably 95 to 267 kg / mol.

[0165] Typically the A / BXB / A midblock formed after coupling has a central region with a cumulative ratio of butadiene units to styrene units wherein the cumulative B / S ratio is at least 3, preferably at least 5, and more preferably at least 10.

[0166] With reference to Table 2 and further with reference to the above embodiments, the total monovinyl aromatic monomer, preferably styrene content of the coupled CTTE 1-14 is 15 to 35 wt%, typically 20 to 30 wt%, preferably 22 to 28 wt%, and more preferably 23 to 26 wt%, with the remainder being conjugated diene monomer, preferably butadiene. Typically, the coupled CTTE comprises 20 to 30 wt% of monovinyl aromatic monomer units and 70 to 80 wt% of conjugated diene monomer units, preferably 22 to 28 wt% of monovinyl aromatic monomer units and 72 to 78 wt% of conjugated diene monomer units, and more preferably 23 to 26 wt% of monovinyl aromatic monomer units and 74 to 77 wt% of conjugated diene monomer units. With further reference to the above examples, a linear diblock A-[A / B] is formed, which is active at the terminal B portion, and a coupling agent is bonded to the active terminal B portion and couples at least two of the linear diblock A-[A / B] units together to form (A-[A / B])-X-([B / A]-A) and / or coupled radial (A-[A / B])nX inverse tapered thermoplastic elastomers. After coupling, the CTTE has a central block comprising units of a monovinyl aromatic monomer, preferably styrene, and a conjugated diene monomer, preferably butadiene, and a block at each end that is a homopolymer of a monovinyl aromatic monomer, preferably polystyrene. The midblock is the [A / B]-X-[B / A] portion, which can be a combination of linear and radial units, depending on whether two or more [A / B] units are bonded to the coupling agent. The mid-block portion in Table 2 is 2 to 20 wt% monovinyl aromatic monomer, preferably styrene and 80 to 98 wt% conjugated diene monomer, preferably butadiene, typically 5 to 15 wt% monovinyl aromatic monomer, preferably styrene and 85 to 95 wt% conjugated diene monomer, preferably butadiene, and preferably 6 to 12 wt% monovinyl aromatic monomer, preferably styrene and 88 to 94 wt% conjugated diene monomer, preferably butadiene, and most preferably 7 to 11 wt% monovinyl aromatic monomer, preferably styrene and 89 to 93 wt% conjugated diene monomer, preferably butadiene. The mid-block blockiness in Table 2 for CTTE 1-14 is 10 to 60 wt%, typically 10 to 56 wt% and preferably 10 to 45 wt%.

[0167] Further reference is made to the above embodiments and to Figure 1-4and Table 2, coupled CTTEs 1-14 and 17, forming a linear diblock A-[A / B] having an active terminal B portion, and a coupling agent is bound to the active terminal B portion, and at least two of the linear diblock A-[A / B] units are coupled together to form (A-[A / B])-X-([B / A]-A) and / or coupled radial (A-[A / B])nX inverse tapered thermoplastic elastomers. After coupling, the CTTE has a central block comprising units of a monovinyl aromatic monomer, preferably styrene, and a conjugated diene monomer, preferably butadiene, and a block at each end that is a homopolymer of a monovinyl aromatic monomer, preferably polystyrene. The midblock is the [A / B]-X-[B / A] portion, which can be a combination of linear and radial units, depending on whether two or more [A / B] units are bound to a coupling agent. Figure 1-4 The monomer distribution along the copolymer chain of the mid-block [A / B]-X-[B / A] portion before coupling of CTTE 14, 16, 17, and 19 is shown, which shows that the mid-block has terminal regions rich in styrene monomer units (low butadiene / styrene cumulative ratio) and a central region rich in butadiene monomer units (high butadiene / styrene cumulative ratio). For about 10.7 wt% of mid-block styrene, CTTE 14 has a butadiene / styrene B / S cumulative ratio of about 16.0 mol / mol; for about 11.3 wt% of mid-block styrene, CTTE 16 has a butadiene / styrene B / S cumulative ratio of about 15.1 mol / mol; for about 9.6 wt% of mid-block styrene, CTTE 17 has a butadiene / styrene B / S cumulative ratio of about 18.1 mol / mol; and for about 10.3 wt% of mid-block styrene, CTTE 14 has a butadiene / styrene B / S cumulative ratio of about 16.7 mol / mol. The CTTE butadiene / styrene B / S cumulative ratio of the mid-block portion in Table 2 is 5 to 30 mol / mol, typically 8 to 25 mol / mol, and preferably 10 to 23 mol / mol, and most preferably 12 to 21 mol / mol. Typically the A / BXB / A midblock formed after coupling has a central region with a cumulative ratio of butadiene units to styrene units wherein the cumulative B / S ratio is at least 3, preferably at least 5, and more preferably at least 10.

[0168] Embodiments of the present invention

[0169] 1. A method for preparing a reverse tapered thermoplastic elastomer composition, comprising:

[0170] Loading a solvent into a reactor and heating the solvent to an initial reaction temperature (Ti), preferably 50-75° C., wherein the amount of the solvent is preferably greater than 75 wt % of the total reaction mixture, wherein the solvent is preferably cyclohexane;

[0171] Adding a polar modifier into the reactor, wherein the polar modifier is preferably ditetrahydrofuranylpropane (DTHFP) or tetrahydrofuran (THF);

[0172] adding a first amount of a monovinyl aromatic monomer, which is preferably styrene, to the reactor, wherein the first amount of the monovinyl aromatic monomer is preferably 15-20 wt % of the total monomer mixture;

[0173] adding a lithium-based initiator to the reactor mixture;

[0174] Allowing the reaction to proceed to form a monovinyl aromatic homopolymer block A, wherein the peak molecular weight Mp of the block A is preferably 5-15 kg / mol;

[0175] adding a second amount of said monovinyl aromatic monomer or a second amount of monovinyl aromatic monomer to the reactor, wherein the second amount of monovinyl aromatic monomer is preferably 2-15 wt % of the total monomer mixture, wherein the second amount is preferably added within 5 minutes, more preferably within less than 2 minutes;

[0176] Conjugated diene monomer B is metered into the reactor, preferably without initial addition of conjugated diene monomer, preferably without waiting time after initial addition of conjugated diene, wherein the total amount of conjugated diene monomer added is preferably greater than 55% by weight of the total monomer mixture, and more preferably 55-90% by weight,

[0177] wherein the conjugated diene monomer is preferably metered in at a dosage rate of 20 to 75 g / min, and wherein the time for metering the conjugated diene monomer is preferably less than 55 min, more preferably less than 25 min;

[0178] The reaction is allowed to proceed to at least 75% conversion, preferably to a final peak temperature Tp of more than 80°C, thereby forming the inverse tapered copolymer block A / B and obtaining a living inverse tapered diblock AA / B copolymer, preferably in a single reactor, preferably without the need to use 2 reactors, wherein the peak molecular weight of the inverse tapered diblock AA / B copolymer is preferably 50-200 kg / mol.

[0179] 2. The method for preparing a reverse tapered thermoplastic elastomer composition of embodiment 1, further comprising:

[0180] A coupling agent, which may be a single coupling agent, a combination of multiple coupling agents, an acrylic oligomer, or a combination of these, is added to the reactor to couple, preferably partially couple, the active inverse tapered diblock AA / B copolymer to form a inverse tapered thermoplastic elastomer, preferably in the same reactor, preferably without transfer to a second reactor, wherein the amount of the coupling agent is preferably 0.0005-0.0500 wt % of the total reaction mixture,

[0181] The ratio of the uncoupled linear diblock A-[A / B] to the coupled radial (A-[A / B])nX inversely tapered thermoplastic elastomer is preferably 0.1-100,

[0182] The weight average molecular weight Mw of the inversely tapered thermoplastic elastomer is preferably 30-1,000 kg / mol, and

[0183] The A / BXB / A midblock formed after coupling preferably has a central region having a cumulative ratio of butadiene units to styrene units, wherein the cumulative B / S ratio is generally at least 1, typically at least 2.5, preferably at least 5, and more preferably at least 10.

[0184] 3. The method for preparing a reverse tapered thermoplastic elastomer composition of embodiment 1 or 2, wherein the total monovinyl aromatic monomer content of the final product is preferably 10-48 wt%.

[0185] 4. The method for preparing a reverse tapered thermoplastic elastomer composition of embodiment 1, 2 or 3, regarding the coupled CTTE, wherein the total monovinyl aromatic monomer content of the coupled CTTE is preferably 10 to 40 wt%, and wherein the coupled CTTE preferably comprises 60 to 90 wt% of conjugated diene monomer units.

[0186] 5. The method of preparing a reverse tapered thermoplastic elastomer composition of any of embodiments 1-4, for a coupled CTTE, wherein the mid-block portion of the CTTE is preferably 2 to 20 wt% monovinyl aromatic monomer and preferably 80 to 98 wt% conjugated diene monomer, and wherein the mid-block blockiness is preferably 5 to 75 wt%.

[0187] Example 2

[0188] Application of polymer modified asphalt (PMA) in road paving

[0189] The low Mw reverse tapered thermoplastic elastomers (CTTE 1-7) prepared as described in Example 1 in Tables 1 and 2 were used as asphalt modifiers or asphalt enhancers in polymer modified asphalt (PMA) for paving formulations. To this end, PG 64-22 pure asphalt (provided by PEMEX) was formulated by hot mixing and high shear rate methods. The method uses triangular high shear grinding. First, the pure asphalt was heated to 120°C without stirring to soften the asphalt under a nitrogen atmosphere. During this stage, very slow stirring was used to prevent the asphalt from overheating and oxidation. Once the asphalt softens, continue heating to 190°C + / - 5°C and increase the mixer stirring to 2500RPM. When 190°C is reached, the reverse tapered thermoplastic elastomer (CTTE) composition is gradually added to the asphalt at a rate of about 10g / min. The stirring is maintained for 120-180 minutes to effectively and completely disperse the CTTE as a reinforcing agent. To ensure that the same level of dispersion was achieved in all formulations, the CTTE dispersion in the asphalt was monitored by fluorescence microscopy using a Zeiss Axiotecy 20X model microscope.

[0190] According to ASTM D36, the ring and ball softening temperature (T RBSP ) to characterize the CTTE polymer modified asphalt (PMA) mixture thus obtained. Needle penetration was measured using a Koheler K95500 model penetration tester according to ASTM D5 at 25°C, 10 seconds and 100 grams. The maximum application temperature ("maximum use T") was measured as the temperature at which the rutting factor or dynamic shear stiffness (G* / sinδ) took a value of 1.0 kPa according to AASHTO TP5 by using a Paar Physica MCR-300-SP model rheometer, where G* is the complex modulus and sinδ is the phase angle, and the AASHTO SUPERPAVE performance grade PG was determined. The dynamic viscosity at 135°C was measured according to ASTMD4402 by using a RDVS-II+ model Brookfield viscometer. The elastic recovery at 25°C in torsion mode was measured according to AASHTO-TF31R. The elastic recovery at 25°C and the ductility at 4°C were measured by using an extensometer.

[0191] The results for the CTTE polymer modified asphalt (CTTE 1-7PMA) are shown in Table 2a below and demonstrate the enhanced performance of the novel inversely tapered thermoplastic elastomer composition as an asphalt modifier for paving at a CTTE polymer content of 2.2 wt% based on the total PMA mixture.

[0192] Table 2a

[0193] Performance of Low Mw CTTE in Paving Asphalt Reinforcement

[0194]

[0195] Reviewing Table 2a, the results show that the PG polymer modified asphalt has significantly lower viscosity, high elastic response, wide range, and good balance of high and low temperature properties. The much lower viscosity of the asphalt formulation not only helps to promote the dispersion of the polymer into the asphalt and improve the time required for mixing, but also facilitates the processing, handling and application of the modified asphalt mixture by improving pumping capacity and / or reducing the energy required to apply the modified asphalt mixture. This also means important cost reduction and a more environmentally friendly method.

[0196] Example 3

[0197] Application in polymer modified asphalt emulsion (PME) for paving

[0198] The low Mw inversely tapered thermoplastic elastomers (CTTE 3-6) prepared as described in Example 1 in Tables 1 and 2 were used as asphalt modifiers or asphalt enhancers in polymer modified emulsions (PME) for paving formulations. First, a PMA mixture of each CTTE composition was prepared as described in Example 2. Next, an aqueous emulsifier solution was prepared by first heating demineralized water to 45°C, then adding about 0.5 wt% of a polyamine-type emulsifier (Redicote E4819, available from Akzo Nobel) to the warm water while gently stirring, followed by adding about 0.4 wt% of a concentrated mineral acid (HCl, 37%). The aqueous solution was stirred until the emulsifier was completely dissolved and the acidity was within the pH range of 2.0±0.1, which was ready for emulsification of the PMA mixture. Finally, the emulsification process was performed at atmospheric pressure by using an IKA colloid mill. The 150°C PMA mixture and the 40°C emulsifier aqueous solution (65:35wt:wt) are pumped into a colloid mill operating at 90°C to form a polymer modified asphalt emulsion (PME). Next, the freshly prepared PME is placed in an 80°C oven for 16 hours. After cooling to ambient temperature, the PME is passed through a 20-mesh copper sieve and the amount of the sieve residue is tested. The polymer modified asphalt emulsion (PME) thus obtained is then treated to separate water and recover the residual PMA mixture.

[0199] The CTTE polymer modified asphalt emulsion (PME) thus prepared was tested for 20 mesh residue, Saybolt Furol Viscosity at 50°C and 5-day storage stability. Once water was separated from the PME, the Ring and Ball softening temperature (T RBSP) The residual PMA mixture was characterized by measuring the needle penetration according to ASTM D5 at 25°C, 10 seconds and 100 grams using a Koheler K95500 model needle penetration tester. The elastic recovery at 25°C and the ductility at 4°C were measured by using an extensometer.

[0200] The results for the CTTE polymer modified asphalt emulsions (CTTE 3-6 PME) are shown in Table 3a below and demonstrate the enhanced performance of the novel inversely tapered thermoplastic elastomer composition as an asphalt modifier in paving emulsions.

[0201] Table 3a

[0202] Performance of Low Mw CTTE in Paving Asphalt Reinforcement

[0203]

[0204] Reviewing Table 3a, the results of PME show low viscosity, good storage stability and acceptable screen residue. In addition, the results of PMA show similar high elastic response before (initial) and after (residual) the emulsification process, as well as an excellent balance between high and low temperature properties.

[0205] Example 4

[0206] Preparation of reverse tapered thermoplastic elastomer (CTTE)

[0207] In Example 4, several novel inverse tapered thermoplastic elastomers (CTTE 20-38) were prepared according to the claimed process. The polymers CTTE 20-38 are (A-[A / B])nX block copolymers, wherein the A-[A / B] diblocks before coupling consist of monovinyl aromatic homopolymer blocks A blocks which are polystyrene blocks (PS) and inverse tapered copolymer blocks [A / B] which are styrene / butadiene copolymer blocks, which after coupling form [A / B]-X-[B / A] midblocks having terminal regions rich in styrene units and a central region rich in butadiene units. CD1 and CD2 are comparative examples of prior art controlled distribution block copolymers prepared by following a procedure similar to that described in US 2003 / 0176582A1 patent application published on September 18, 2003 by KRATON Polymers US LLC and Bening et al. CD2 is a polymer prepared using only the controlled distribution copolymer block [B / A] of styrene / butadiene for the purpose of illustrating the monomer distribution of the mid-block copolymer chain prior to coupling.

[0208] Through GPC, 1These novel inverse tapered thermoplastic elastomer (CTTE 20-38) compositions were characterized by H NMR and DSC methods to determine: molecular weight average and molecular weight distribution properties, such as peak molecular weight (Mp), weight average molecular weight (Mw), and diblock to coupling ratio for linear diblock and coupled modes; microstructural properties, such as total styrene, block styrene, and vinyl A / B block content; glass transition temperature (Tg) of the A / B inverse tapered copolymer blocks; and melt flow rate (MFI) of the CTTE inverse tapered thermoplastic compositions. In addition, calculations of midblock styrene and midblock blockiness were also performed following the methods used by KRATON Polymers US LLC and Bening et al. in US2003 / 0176582A1, published on September 18, 2003, to characterize the polymer midblock or "B" block as Calc. Mid PSC and Calc. Mid Blocky. Tables 4-5 list the analytical characterization results, and Table 6 lists the polymerization conditions for CTTE 20-38 and CD 1-2. The following describes a general procedure similar to that described in Example 1 for preparing these novel inverse tapered thermoplastic elastomers (CTTE 20-38) and controlling the monomer distribution in the anionic copolymerization of 1,3-butadiene (B) and styrene (S) in the presence of ditetrahydrofurylpropane (DTHFP) or tetrahydrofuran (THF) as a suitable polar modifier and randomizer for the styrene / butadiene [S / B] inverse tapered copolymer blocks. The abbreviations used for the polymerization conditions in Table 6 below are defined as follows: CHx = cyclohexane; STY = styrene; and BD = 1,3-butadiene. For the novel inverse tapered thermoplastic elastomers CTTE 20-32 and 37-38 and CD 1 comparative example, silicon tetrachloride (SiCl4) was used as a coupling agent. For CTTE 33-36, an acrylic oligomer similar to that described in US Patent 8,981,008 was used as the coupling agent.

[0209] The novel inversely tapered thermoplastic elastomer (CTTE 20-38) compositions of the present invention and controlled distribution comparative examples CD 1-2 are prepared in a 7.57 liter reactor system operated in batch and / or semi-batch mode under an inert nitrogen atmosphere according to the teachings of the present invention. Just before being added to the reactor system, the solvent and monomers are fully purified by passing through a set of columns filled with alumina and molecular sieves to reduce their moisture content to a maximum of 5 ppm. For the first polymerization step, an appropriate amount of purified solvent (CHx) is charged to the reactor and heated to an initial reaction temperature (Ti) of about 50°C. For CD 1 polymer, Ti is set to a lower temperature of about 30°C. Once Ti is reached, a suitable polar modifier (randomizer) such as ditetrahydrofuranyl propane (DTHFP) or tetrahydrofuran (THF) is added to the reactor, followed by a first addition of monovinyl aromatic monomer (first STY) accounting for about 17.5 wt% to about 30.0 wt% of the total monomer mixture. For CD1, the first addition of monovinyl aromatic monomer (first STY) at about 27 wt% of the total monomer mixture was similar to CTTE37-38 in order to directly compare and differentiate our composition / method from the prior art. For CD2, in order to prepare isolated styrene / butadiene reverse tapered copolymer blocks by 1 HNMR directly analyzes the mid-block styrene, mid-block blockiness and monomer distribution along the copolymer chain of the [A / B] reverse tapered copolymer block without the calculations required to eliminate the interference of the monovinyl aromatic homopolymer block A (PS block) in CTTE 20-38 and CD 1, without the first styrene monomer addition, which is achieved by taking aliquots throughout the copolymerization process and then performing NMR characterization. The reaction mixture is stabilized at Ti, and then n-butyl lithium or another suitable initiator is added directly to the reactor mixture containing at least the amount of polar modifier required to effectively initiate anionic polymerization of the living polystyrene block in a suitable solvent solution. The amount of initiator is stoichiometrically calculated as described in the literature to form a single block with the desired molecular weight and to compensate for residual impurities. The first polymerization step is then allowed to proceed adiabatically until complete conversion to form a monovinyl aromatic homopolymer block A with a peak molecular weight Mp of about 10,000 to about 20,000.

[0210] For the second polymerization step, for CTTE 20-38, the addition of both monomers is started simultaneously, and a second monovinyl aromatic monomer addition (second STY) of about 6.3 wt% to about 22 wt% of the total monomer mixture is charged to the reactor at a specified dosage rate of about 41 to 146 g / min over a predetermined dosage time of about 1 minute, and a conjugated diene monomer (BD) of about 50 wt% to about 70 wt% of the total monomer mixture is slowly charged to the reactor at a specified dosage rate of about 48 g / min to about 70 g / min over a predetermined dosage time of about 6.5 minutes to about 7 minutes. These monomer additions are carried out in a programmed batch and / or semi-batch mode, and the amount of polar modifier (randomizer) is adjusted from about 0.01 wt% to about 0.20 wt% of the total reaction mixture to promote the formation of a statistically distributed tapered S / B copolymer block with gradual changes in composition and vinyl microstructure (1,2-addition) along the copolymer chain. The second polymerization step is then carried out adiabatically until complete conversion is achieved and the final peak temperature (Tp) is increased from about 96°C to about 107°C, thereby forming an inverse tapered copolymer [A / B] block and thereby obtaining a living inverse tapered A-[A / B] diblock copolymer having a target peak molecular weight Mp of about 70,000 to about 213,000. For the second polymerization step of controlled distribution comparative example CD 1-2, the addition of styrene monomer was started 1 minute after the start of the butadiene monomer addition, so that the second addition of about 22 wt % to about 30 wt % of the total monomer mixture (second STY) was slowly charged into the reactor at a specified dosage rate of about 9 to 10 g / min within a predetermined dosage time of about 15 minutes to about 16 minutes, and the addition of about 50 wt % to about 70 wt % of the total monomer mixture of conjugated diene monomer (BD) was very slowly charged into the reactor at a specified dosage rate of about 10 g / min to about 11 g / min within a predetermined dosage time of about 31 minutes to about 33 minutes. The addition of these monomers is carried out in a programmed batch and / or semi-batch mode, and the amount of polar modifier (randomizer) is adjusted from about 0.047 wt% to about 0.048 wt% of the total reaction mixture to promote the formation of a statistically distributed tapered S / B copolymer block with a gradual change in composition and low vinyl microstructure (1,2-addition) along the copolymer chain. The second polymerization step is then carried out adiabatically until full conversion and the final peak temperature (Tp) is increased from about 80°C to about 82°C to form a controlled distribution [B / A] block, and thus obtain an active controlled distribution A-[B / A] diblock copolymer with a target value of peak molecular weight Mp of about 95,000 to about 124,000.

[0211] Finally, a sufficient amount of a suitable coupling agent such as silicon tetrachloride (SiCl4) or an acrylic oligomer is added to the reactor, accounting for about 0.0027 to about 0.032 of the total reaction mixture, to partially couple the active reverse tapered A-[A / B] diblock copolymer to obtain the desired ratio of uncoupled linear diblock A-[A / B] to the coupled radial (A-[A / B])nX reverse tapered thermoplastic elastomer composition of the present invention, where X is the residual part of the coupling reaction process. The remaining active polymer chains are terminated by adding a 10 mol% excess of the stoichiometric amount of a suitable alcohol to the final reaction mixture. A similar procedure is followed to couple the controlled distribution styrene / butadiene copolymer diblock of CD 1 Comparative Example.

[0212] Tables 4 and 5 list the analytical characterization results of the novel inverse tapered thermoplastic elastomer composition CTTE 20-38. All average molecular weights (Mp and Mw) are given in units of 1000 (k) and are calculated by GPC relative to polystyrene standards. The peak average molecular weight Mp of the monovinyl aromatic homopolymer block A or polystyrene block of CTTE 20-38 is from about 10.2 kg / mol to about 19.8 kg / mol. The peak average molecular weight Mp of the A-[A / B] diblock copolymer or S-[S / B] styrene-butadiene diblock copolymer of CTTE 20-38 is from about 70 kg / mol to about 213 kg / mol. The peak average molecular weight Mp of the [B / A] controlled distribution copolymer or [B / S] styrene-butadiene copolymer of CD 1-2 is from about 95 kg / mol to about 124 kg / mol. The ratio of the Mp of the coupled radial (A-[A / B])nX of CTTE 20-38 to the Mp of the uncoupled linear diblock A-[A / B] is about 3.1 to about 11.9. The weight average molecular weight Mw of CTTE 20-38 is about 179 kg / mol to about 521 kg / mol. The ratio of the uncoupled linear diblock A-[A / B] of CTTE 20-38 to the coupled radial (A-[A / B])nX is about 0.2 to about 3.2, which is the coupling efficiency determined based on the GPC area. Based on the total butadiene units, the vinyl [A / B] block content of CTTE 20-38 is about 18.5 wt% to about 54.0 wt%. The glass transition temperature of the [A / B] reverse tapered copolymer block of CTTE 20-38 is about -81.9°C to about -47.8°C. The melt flow rate (MFI) of the CTTE 20-38 composition is from about 0 (NF) to about 94.9 g / 10 min. The NMR-determined content of CTTE 20-38 is: from about 14.1 wt% to about 49.5 wt% total styrene based on the total copolymer; from about 53.2 wt% to about 91.0 wt% block styrene based on the total styrene units; from about 5.2 wt% to about 34.4 wt% mid-block styrene based on the mid-block copolymer, and from about 6.6 wt% to about 73.8 wt% mid-block blockiness based on the mid-block styrene units.

[0213] Figure 5 The monomer distribution in the [A / B] midblock segments prior to coupling the inventive inverse tapered block copolymers CTTE 20, 37, and 38, and the monomer distribution in the [B / A] midblock segments prior to coupling the comparative controlled distribution examples CD 1 and 2, are depicted by taking aliquots throughout the copolymerization and then characterizing them by NMR. For CD 2, to separate the styrene / butadiene controlled distribution copolymer blocks and by 1H NMR directly analyzes the monomer distribution along the copolymer chain in the [B / A] midblock segment without the calculations required to deduct the monovinyl aromatic homopolymer block A (PS block) in CTTE 37-38 and CD 1, without the first styrene monomer addition. The calculations for monomer distribution in CTTE 37-38 and CD 1 follow the method used to characterize the polymer midblock or "B" block in patent application US2003 / 0176582 A1 published on September 18, 2003 by KRATON Polymers US LLC and Bening et al.

[0214] Figure 5 It is clearly shown that the cumulative composition of the styrene monomers introduced in the [A / B] mid-block segments of CTTE 37-38 gradually decreases with increasing conversion of the butadiene / styrene mid-block polymerization. After coupling, the [A / B] mid-block segments form a complete [A / B]-X-[B / A] mid-block having terminal regions rich in styrene monomer units (low butadiene / styrene cumulative ratio) and a central region rich in butadiene monomer units (high butadiene / styrene cumulative ratio), which is exactly the opposite in the controlled distribution compositions of the prior art and is more pronounced in the comparative examples CD 1 and CD 2 of the controlled distribution compositions. This is also a surprising and unexpected result in view of the fact that a relatively large amount of styrene monomers (about 30 wt% of the monomer mixture) are present during the copolymerization of the mid-block segments and a relatively small amount of polar modifiers (randomizers) used to prepare low vinyl styrene / butadiene copolymers (about 20 wt% of vinyl) are used in these copolymerizations. It is also noteworthy that low levels of midblock blockiness can be obtained even though the terminal regions of the styrene / butadiene midblock are relatively styrene-rich (low butadiene / styrene cumulative ratio). Furthermore, it is shown that the incorporation of styrene into the inverse tapered [A / B] midblock segments depends not only on the amount of styrene monomer and the amount and type of randomizer, but also on the temperature profile of the copolymerization and the dosing time of the monomers. Figure 5 It is shown that the incorporation of styrene into the copolymer chain is generally higher for the [A / B] mid-block segments of CTTE 37 and 38 compared to CTTE 20. Figure 5 It also shows that when the amount of polar modifier (randomizer) is relatively small (low vinyl), there is a more significant and opposite change in styrene incorporation in the [B / A] midblock segments of CD 1 and CD 2 in response to a significant increase in the dosing time of butadiene and styrene monomers and the use of THF as a randomizer at lower temperatures.

[0215] Table 4

[0216] Reverse tapered thermoplastic elastomer composition

[0217]

[0218] a Coupling efficiency ratio based on cumulative GPC area % relative to the molecular weight average of PS standards;

[0219] b RMN 1 H300MHz, vinyl based on total butadiene units (wt%);

[0220] c Glass transition temperature (inflection point) measured by DSC at 10°C / min;

[0221] d NF: Non-flow observation for melt flow index testing.

[0222] Table 5

[0223] NMR results of reverse tapered thermoplastic elastomer

[0224]

[0225] a RMN 1 H300 MHz, total styrene based on total copolymer (wt %);

[0226] b RMN 1 H300MHz, block styrene based on total styrene units (wt%);

[0227] c Midblock styrene (wt %) calculated based on midblock copolymer;

[0228] d Midblock blockiness (wt%) calculated based on midblock styrene units.

[0229] Table 6

[0230] Reverse tapered thermoplastic elastomer method

[0231]

[0232] a wt% of total reaction mixture

[0233] b wt% of total monomer mixture

[0234] One embodiment of the present invention based on Example 4 and Table 6 is a method for preparing a reverse tapered thermoplastic elastomer in a batch or semi-batch mode, the method comprising:

[0235] preferably and optionally purifying the solvent and monomers to reduce their moisture content to a maximum of 50 ppm, preferably less than 25 ppm and more preferably less than 5 ppm;

[0236] Loading a solvent into the reactor and heating the solvent to an initial reaction temperature (Ti) of 40°C to 60°C, possibly 45°C to 55°C, preferably 47°C to 53°C, and more preferably 48°C to 52°C, and about 50°C, the solvent exceeding 75 wt% of the total reaction mixture, preferably 80 to 95 wt%, more preferably 84 to 90 wt%, and most preferably 85 to 87 wt%, and typically about 85 wt% or 86 wt%, wherein the solvent is preferably cyclohexane;

[0237] Preferably, a suitable polar modifier is added to the reactor, the polar modifier is preferably ditetrahydrofurylpropane (DTHFP) or tetrahydrofuran (THF), and more preferably DTHFP;

[0238] adding a monovinyl aromatic monomer, preferably styrene, to the reactor, typically in an amount of 10 to 35 wt %, preferably 15 to 33 wt %, and more preferably 16 to 31 wt %, of the total monomer mixture, with 17.5 wt %, 27.0 wt % and 30.0 wt % being possible amounts;

[0239] Preferably and optionally the solvent, polar modifier and monovinyl aromatic monomer are stabilized at a temperature Ti ± 10°C, preferably ± 5°C and more preferably ± 2°C, and most preferably stabilized at Ti;

[0240] adding a lithium-based initiator, preferably n-butyllithium, in a suitable solvent solution to the reactor mixture, preferably wherein the amount of initiator is stoichiometrically calculated to form a single block and to compensate for impurities;

[0241] The reaction is preferably and optionally carried out to complete conversion, preferably to at least 90% conversion, more preferably to 95% or more conversion, to form a monovinyl aromatic homopolymer block A, the monovinyl aromatic homopolymer block A optionally having a peak molecular weight Mp of 5 to 25 kg / mol, preferably having a peak molecular weight of 8 to 22 kg / mol, and more preferably having a peak molecular weight of 10 to 20 kg / mol;

[0242] A second charge of monovinyl aromatic monomer, preferably styrene, is preferably added to the reactor, typically within a period of 5 minutes, preferably within a period of less than 2 minutes and more preferably within a period of about 1 minute, typically from 5 to 25 wt %, preferably from 6 to 22 wt % of the total monomer mixture, with values ​​of 6.3 wt %, 12.4 wt %, 16.5 wt % and 22.1 wt % being possible suitable values;

[0243] Conjugated diene monomer B is added to the reactor, preferably starting at the same time as the second monovinyl aromatic monomer addition, preferably without initial addition of conjugated diene monomer, and preferably without waiting time after the initial addition of conjugated diene, wherein the total amount of conjugated diene monomer added is greater than 40wt% of the total monomer mixture, typically 45wt% to 90wt% of the total monomer mixture, usually 45wt% to 80wt%, preferably 50wt% to 72wt%,

[0244] wherein the conjugated diene monomer is added at a dosage rate of 30 to 90 g / min, typically at a dosage rate of 35 to 80 g / min, typically at a dosage rate of 45 to 75 g / min, and preferably at a dosage rate of 48 to 70 g / min,

[0245] wherein the time for adding the conjugated diene monomer is shorter than 90 minutes, 80 minutes, 70 minutes, 60 minutes, 50 minutes, 40 minutes, 30 minutes, 20 minutes or 15 minutes, and is usually shorter than 13 minutes, usually added within a period of 4 to 12 minutes, preferably added within 5 to 9 minutes, more preferably added within 6.5 to 7 minutes, preferably wherein the conjugated diene is butadiene or isoprene, and more preferably 1,3-butadiene;

[0246] The reaction is carried out to a conversion rate of at least 80%, usually to a conversion rate of more than 90%, preferably to a conversion rate of at least 98%, more preferably to a conversion rate of at least 99%, and most preferably to complete conversion, preferably to a final peak temperature Tp of more than 90°C, more preferably 95 to 110°C or 100 to 105°C, thereby forming a reverse tapered copolymer block A / B and obtaining a living reverse tapered diblock AA / B copolymer, the reaction is preferably carried out in a single reactor, and preferably does not require the use of 2 reactors, usually wherein the peak molecular weight of the reverse tapered diblock AA / B copolymer is 60 kg / mol to 230 kg / mol, preferably wherein the peak molecular weight of the reverse tapered diblock AA / B copolymer is 65 kg / mol to 220 kg / mol, and more preferably wherein the peak molecular weight of the reverse tapered diblock AA / B copolymer is 70 kg / mol to 215 kg / mol, and the range of 100 kg / mol to 130 kg / mol is most typical.

[0247] The optional but preferred next step is preferably carried out in the same reactor without transfer to a second reactor and comprises:

[0248] A suitable coupling agent or a combination of coupling agents, preferably silicon tetrachloride or an acrylic oligomer, is added to the reactor to partially couple the active inverse tapered diblock AA / B copolymer to form an inverse tapered thermoplastic elastomer, wherein the amount of the coupling agent is 0.0020 to 0.050 wt %, typically 0.0023 to 0.040 wt %, and preferably 0.0025 to 0.0350 wt %, of the total reaction mixture.

[0249] Typically wherein the ratio of uncoupled linear diblock A-[A / B] to coupled radial (A-[A / B])nX inversely tapered thermoplastic elastomer is from 0.1 to 4.5, preferably wherein the ratio is from 0.1 to 4.0, and more preferably wherein the ratio is from 0.2 to 2.7,

[0250] Typically, the weight average molecular weight Mw of the inversely tapered thermoplastic elastomer is from 100 kg / mol to 500 kg / mol, typically from 150 kg / mol to 400 kg / mol, and preferably from 170 kg / mol to 375 kg / mol.

[0251] Typically the A / BXB / A midblock formed after coupling has a central region with a cumulative ratio of butadiene units to styrene units wherein the cumulative B / S ratio is at least 3, preferably at least 5, and more preferably at least 10.

[0252] With reference to Table 5 and further with reference to the above embodiments, the total monovinyl aromatic monomer, preferably styrene content of the coupled CTTE 20-38 is 10 to 55 wt%, typically 14 to 50 wt%, preferably 17 to 45 wt%, and more preferably 20 to 40 wt%, with the remainder being conjugated diene monomer, preferably butadiene. Typically, the coupled CTTE comprises 14 to 50 wt% of monovinyl aromatic monomer units and 50 to 86 wt% of conjugated diene monomer units, preferably 17 to 45 wt% of monovinyl aromatic monomer units and 55 to 83 wt% of conjugated diene monomer units, and more preferably 20 to 40 wt% of monovinyl aromatic monomer units and 60 to 80 wt% of conjugated diene monomer units. With further reference to the above examples, a linear diblock A-[A / B] is formed, which is active at the terminal B portion, and a coupling agent is bonded to the active terminal B portion and couples at least two of the linear diblock A-[A / B] units together to form (A-[A / B])-X-([B / A]-A) and / or coupled radial (A-[A / B])nX inverse tapered thermoplastic elastomers. After coupling, the CTTE has a central block comprising units of a monovinyl aromatic monomer, preferably styrene, and a conjugated diene monomer, preferably butadiene, and a block at each end that is a homopolymer of a monovinyl aromatic monomer, preferably polystyrene. The midblock is the [A / B]-X-[B / A] portion, which can be a combination of linear and radial units, depending on whether two or more [A / B] units are bonded to the coupling agent. The mid-block portion in Table 5 is 4 to 40 wt% monovinyl aromatic monomer, preferably styrene and 60 to 96 wt% conjugated diene monomer, preferably butadiene, typically 5 to 35 wt% monovinyl aromatic monomer, preferably styrene and 65 to 95 wt% conjugated diene monomer, preferably butadiene, and preferably 5 to 32 wt% monovinyl aromatic monomer, preferably styrene and 68 to 95 wt% conjugated diene monomer, preferably butadiene, with 5 to 30 wt% monovinyl aromatic monomer, preferably styrene and 70 to 95 wt% conjugated diene monomer, preferably butadiene being most preferred. The mid-block blockiness of CTTE 20-38 in Table 5 is 5 to 80 wt%, typically 6 to 75 wt%, and preferably 6 to 45 wt%.

[0253] Further reference is made to the above embodiments and to Figure 5and Table 4, forming a coupled CTTE 20-38 linear diblock A-[A / B], which has an active terminal B portion, and the coupling agent is bound to the active terminal B portion, and at least two of the linear diblock A-[A / B] units are coupled together to form (A-[A / B])-X-([B / A]-A) and / or coupled radial (A-[A / B])nX inverse tapered thermoplastic elastomers. After coupling, the CTTE has a central block comprising units of a monovinyl aromatic monomer, preferably styrene, and a conjugated diene monomer, preferably butadiene, and a block at each end that is a homopolymer of a monovinyl aromatic monomer, preferably polystyrene. The middle block is the [A / B]-X-[B / A] portion, which can be a combination of linear and radial units, depending on whether two or more [A / B] units are bound to the coupling agent. Figure 1-4 The monomer distribution along the copolymer chain of the mid-block [A / B]-X-[B / A] portion before coupling of CTTE 37 and 38 is shown, which shows that the mid-block has a terminal region rich in styrene monomer units (low butadiene / styrene cumulative ratio) and a central region rich in butadiene monomer units (high butadiene / styrene cumulative ratio). For about 34.4 wt% of mid-block styrene, CTTE 37 has a butadiene / styrene B / S cumulative ratio of about 3.7 mol / mol; and for about 34.3 wt% of mid-block styrene, CTTE 38 has a butadiene / styrene B / S cumulative ratio of about 3.7 mol / mol. The CTTE butadiene / styrene B / S cumulative ratio of the mid-block portion in Table 4 is 2 to 30 mol / mol, typically 3 to 25 mol / mol, and preferably 3 to 23 mol / mol, and most preferably 3 to 21 mol / mol. Typically the A / BXB / A midblock formed after coupling has a central region with a cumulative ratio of butadiene units to styrene units wherein the cumulative B / S ratio is at least 3, preferably at least 5, and more preferably at least 10.

[0254] In addition to comparative testing involving compositional and structural differences between the inverse tapered copolymers of the present invention and the controlled distribution copolymers of the prior art, the performance of the inverse tapered copolymers of the present invention on asphalt modification was next compared to the controlled distribution copolymers of the prior art. The results of the asphalt / asphalt evaluation of the inverse tapered thermoplastic elastomer CTTE38 composition of the present invention compared to the prior art controlled distribution CD1 control are shown in Table B below. The CTTE 38 polymer modified asphalt (CTTE 38PMA) and CD1 polymer modified asphalt (CD1 PMA) results show that at a polymer content of 4.0wt% based on the total PMA mixture, the performance of the new inverse tapered thermoplastic elastomer composition as an asphalt modifier for paving is enhanced. The results for CTTE 38PMA and CD1 PMA show similar viscosity, softening point, ductility, and elastic recovery. The low viscosity of the asphalt formulation helps to facilitate the dispersion of the polymer into the asphalt and improves the time required for mixing, and also facilitates the processing, handling and application of the modified asphalt mixture by improving pumpability and / or reducing the energy required to apply the modified asphalt mixture, which also means important cost reductions and a more environmentally friendly process. Surprisingly, the results of the CTTE 38PMA and CD1 PMA show an unexpectedly wider range of AASHTO SUPERPAVE performance grades PG for the reverse-tapered CTTE 38 polymer-modified asphalt of the present invention when compared to the controlled distribution CD1 polymer-modified asphalt, with a better balance between high and low temperature properties. The reverse-tapered CTTE 38 polymer-modified asphalt of the present invention exhibits a higher upper temperature limit (i.e., 88°C) than the controlled distribution CD1 polymer-modified asphalt (i.e., 82°C), which relates to the maximum temperature at which the asphalt can maintain sufficient rigidity to resist rutting. The inversely tapered CTTE 38 polymer modified asphalt of the present invention exhibits a similar lower temperature limit (i.e., -6°C) as the controlled distribution CD1 polymer modified asphalt (i.e., -6°C), which relates to the lowest temperature at which the asphalt can remain sufficiently flexible to resist thermal cracking. Table B Performance Comparison on Asphalt Reinforcement for Paving

[0255] CTTE polymer modified asphalt at 4.0wt% CTTE 38 CD1 Brookfield viscosity at 135°C (cp) 2575 2425 Ring and ball softening point(℃) 74 74 Ductility at 4℃(cm) 5.0 5.0 Elastic recovery at 25°C measured by extensometer (%) 86 88 AASHTO SUPERPAVE Performance Grade PG 88-6 82-6

[0256] The inversely graded CTTE 38PMA of the present invention is characterized by a better balance of processing and reinforcement properties than the controlled distribution CD1 PMA of the prior art. The CTTE 38 polymer-modified asphalt shows a wider and better AASHTO SUPERPAVE performance grade PG than the CD1 polymer-modified asphalt at similar viscosity, softening point, ductility and elastic recovery. The AASHTO SUPERPAVE performance grade PG 88-6 means that the CTTE 38PMA of the present invention meets the standard of a rutting factor or dynamic shear stiffness (G* / sinδ) of 1.0 kPa at higher temperatures, where G* is the complex modulus and sinδ is the phase angle, which is a measure of the minimum stiffness and elastic behavior required for the polymer-modified asphalt. The CTTE 38 polymer-modified asphalt shows PG88-6, which predicts better pavement rutting performance than the CD1 polymer-modified asphalt PG82-6, i.e., more resistance to permanent deformation at high temperatures. The better performance grade PG of the CTTE 38 polymer modified asphalt of the present invention is attributed to the novel inverse tapered A-[A / B] or S-[S / B] monomer distribution and microstructural characteristics of the present invention, i.e., higher styrene incorporation into the [A / B] or [S / B] midblock segments (lower butadiene / styrene cumulative ratio) close to the A homopolymer blocks or S polystyrene blocks relative to lower styrene incorporation (higher butadiene / styrene cumulative ratio) away from the A homopolymer blocks or S polystyrene blocks, combined with high vinyl and low midblock blockiness.

[0257] Embodiments of the present invention

[0258] 6. A method for preparing a reverse tapered thermoplastic elastomer composition, comprising:

[0259] Loading a solvent into a reactor and heating the solvent to an initial reaction temperature (Ti), preferably 50-75° C., wherein the amount of the solvent is preferably greater than 75 wt % of the total reaction mixture, wherein the solvent is preferably cyclohexane;

[0260] Adding a polar modifier into the reactor, wherein the polar modifier is preferably ditetrahydrofuranylpropane (DTHFP) or tetrahydrofuran (THF);

[0261] adding a first amount of a monovinyl aromatic monomer, preferably styrene, to the reactor, wherein the first amount of the monovinyl aromatic monomer is preferably from 5 wt % to 40 wt % of the total monomer mixture;

[0262] adding a lithium-based initiator to the reactor mixture;

[0263] Allowing the reaction to proceed to form a monovinyl aromatic homopolymer block A, wherein the peak molecular weight Mp of the block A is preferably 5-30 kg / mol;

[0264] adding a second amount of the monovinyl aromatic monomer or a second amount of monovinyl aromatic monomer to the reactor, wherein the second amount of monovinyl aromatic monomer is preferably from 2 wt% to 35 wt% of the total monomer mixture, wherein the second amount is preferably added within 5 minutes, and more preferably within less than 2 minutes;

[0265] The conjugated diene monomer B is metered into the reactor, preferably without initial addition of the conjugated diene monomer, and preferably without a waiting time after the initial addition of the conjugated diene, preferably commencing simultaneously with the addition of the second amount of the monovinyl aromatic monomer, wherein the total amount of the metered conjugated diene monomer is preferably greater than 35 wt % of the total monomer mixture, and more preferably from 40 to 95 wt %,

[0266] wherein the conjugated diene monomer is preferably metered in at a dosage rate of 20 to 95 g / min, and

[0267] The time for metering the conjugated diene monomer is preferably less than 45 minutes, more preferably less than 22 minutes;

[0268] The reaction is carried out to a conversion rate of at least 75%, preferably to a final peak temperature Tp of more than 75°C, thereby forming the reverse tapered copolymer block A / B and obtaining an active reverse tapered diblock AA / B copolymer, preferably in a single reactor, preferably without the need to use 2 reactors, wherein the peak molecular weight of the reverse tapered diblock AA / B copolymer is preferably 40-400 kg / mol, more preferably 50-300 kg / mol.

[0269] 7. The method for preparing a reverse tapered thermoplastic elastomer composition of embodiment 6, further comprising:

[0270] A coupling agent is added to the reactor to couple, preferably partially couple, the active inverse tapered diblock AA / B copolymer to form an inverse tapered thermoplastic elastomer, wherein the coupling agent can be a single coupling agent, a combination of multiple coupling agents, an acrylic oligomer, or a combination of these, preferably in the same reactor, preferably without transfer to a second reactor, wherein the amount of coupling agent is preferably 0.0005-0.0900 wt% of the total reaction mixture, wherein the ratio of uncoupled linear diblock A-[A / B] to coupled radial (A-[A / B])nX inverse tapered thermoplastic elastomer is preferably 0.05-15.0,

[0271] The weight average molecular weight Mw of the inversely tapered thermoplastic elastomer is preferably 30-1,000 kg / mol, and

[0272] The A / BXB / A midblock formed after coupling preferably has a central region having a cumulative ratio of butadiene units to styrene units, wherein the cumulative B / S ratio is generally at least 1, typically at least 2.5, preferably at least 5, and more preferably at least 10.

[0273] 8. The method for preparing a reverse tapered thermoplastic elastomer composition of embodiment 6 or 7, wherein the total monovinyl aromatic monomer content of the final product is preferably 5-75 wt%, more preferably 10-55 wt%.

[0274] 9. The method for preparing a reverse tapered thermoplastic elastomer composition of embodiment 6, 7 or 8, regarding the coupled CTTE, wherein the total monovinyl aromatic monomer content of the coupled CTTE is preferably 5 to 70 wt%, and wherein the coupled CTTE preferably comprises 30 to 95 wt% of conjugated diene monomer units.

[0275] 10. The method of preparing a reverse tapered thermoplastic elastomer composition of any of embodiments 6-9, regarding the coupled CTTE, wherein the mid-block portion of the coupled CTTE is preferably 2 to 60 wt% of monovinyl aromatic monomer and preferably 40 to 98 wt% of conjugated diene monomer, and wherein the mid-block blockiness is preferably 5 to 80 wt%.

[0276] 11. The method of making a reverse tapered thermoplastic elastomer composition of any of embodiments 6 to 10, wherein the proportion of monovinyl aromatic monomer in the mid-block decreases as the mid-block is formed.

[0277] Example 5

[0278] Application of polymer modified asphalt (PMA) in road paving

[0279] The high Mw inversely tapered thermoplastic elastomer compositions (CTTE 8-13) prepared as described in Example 1 and in Tables 1 and 2 were used as asphalt modifiers or asphalt enhancers in polymer modified asphalts (PMAs) for use in paving formulations. The CTTE 8-13 PMA formulations were prepared and characterized following the procedure described in Example 2.

[0280] The results for CTTE polymer modified asphalt (CTTE 8-13PMA) are shown in Table 5a below and demonstrate the enhanced performance of the novel inversely tapered thermoplastic elastomer composition as an asphalt modifier for paving at a CTTE polymer content of 2.2 wt% based on the total PMA mixture.

[0281] Table 5a

[0282] Performance of High Mw CTTE in Paving Asphalt Reinforcement

[0283]

[0284] Reviewing Table 5a, the results show the low viscosity, higher elastic response, wide range, and excellent balance of high and low temperature properties of the PG polymer modified asphalt. The combination of low viscosity and high elastic response of the asphalt formulation containing the CTTE composition provides an ideal balance between processability and enhanced performance.

[0285] Example 6

[0286] Application of polymer modified asphalt (PMA) in roofing and waterproofing membranes

[0287] The high Mw inversely tapered thermoplastic elastomer compositions (CTTE 8-13) prepared as described in Example 1 in Tables 1 and 2 were used as asphalt modifiers or asphalt enhancers in polymer modified asphalt (PMA) for roofing and waterproofing membrane formulations. The CTTE 8-13 polymer modified asphalt (PMA) formulations were prepared following the procedure described in Example 2.

[0288] According to ASTM D36, the ring and ball softening temperature (T RBSP ) characterize the CTTE 8-13 polymer modified asphalt (PMA) mixture thus obtained. Needle penetration was measured using a Koheler K95500 model penetration tester according to ASTM D5 at 60°C, 10 seconds and 100 grams. Dynamic viscosity at 160°C and 190°C was measured according to ASTM D4402 by using a RDVS-II+ model Brookfield viscometer. Flexibility at low temperatures was determined by measuring the BDA cold bend temperature.

[0289] The results for CTTE polymer modified asphalt (CTTE 8-13PMA) are shown in Table 6a below and demonstrate the enhanced performance of the new inversely tapered thermoplastic elastomer composition as an asphalt modifier for roofing and waterproofing membranes at 8 wt% CTTE polymer content based on the total PMA mixture.

[0290] Table 6a

[0291] Performance of high Mw CTTE in bitumen reinforcement of roofing and waterproofing membranes

[0292]

[0293] Reviewing Table 6a, the results show low viscosity, high softening point, improved flexibility at low temperatures, and an excellent balance of high and low temperature properties. The combination of low viscosity and high softening point of the asphalt formulation with CTTE composition provides a very desirable balance between processability and reinforcement properties.

[0294] Example 7

[0295] Polymer Modified Asphalt (PMA) Applications in Paving and Roofing Membranes

[0296] According to the teachings of the present invention, a high Mw inversely tapered thermoplastic elastomer composition was prepared in a 180 liter reactor system operated in batch or semi-batch mode under an inert nitrogen atmosphere. CTTE Prototype Dyne 143A was obtained following the procedure described in Example 1 and used as an asphalt modifier or asphalt enhancer in polymer modified asphalt (PMA) for paving and roofing membrane formulations. CTTE Prototype Dyne 143A PMA formulations were prepared and characterized following the procedures described in Examples 2 and 6.

[0297] The results for CTTE Prototype Dyne 143A PMA are shown in Table 7 below and show the enhanced performance of the novel inversely tapered thermoplastic elastomer composition as an asphalt modifier in paving at 2.3 wt% CTTE polymer content and in roofing membranes at 6 wt% and 12 wt% based on the total PMA mixture. The processing performance of CTTE Prototype Dyne 143A PMA was compared with PMA mixtures of two commercially available block copolymers, Solprene 411 and Solprene 1205. Solprene 411 is a multi-arm highly coupled block copolymer (also known as a radial SBn thermoplastic elastomer) with a total styrene content of about 30 wt% as pure blocks and no tapered characteristics. Solprene 1205 is a conventional tapered diblock B / SS copolymer (also known as a tapered SBR) with a total styrene content of about 25 wt% and a block styrene content of about 17.5 wt%.

[0298] Table 7

[0299] Performance of high Mw CTTE in asphalt reinforcement of paving and roofing membranes

[0300]

[0301] In addition to Table 7, Figure 6 and Figure 7Depicted are 20X fluorescence microscopy images of CTTE Prototype Dyne 143A PMAs monitored at 190 °C throughout the mixing process and prepared with 2.3 wt% and 6 wt% polymer, respectively. Each arrow points to the image corresponding to the mixing time when complete polymer dispersion of each PMA blend was observed. The dispersion properties of CTTE Prototype Dyne 143A in PMA were compared to PMA blends of commercially available polymers Solprene 411 and Solprene 1205. Fluorescence microscopy images allow for observation of the morphology of the polymer-rich phase and the asphalt-rich phase. The polymer-rich phase was observed as the brighter areas, and the asphalt-rich phase as the darker areas. Figure 6 The qualitative comparison of fluorescence microscopy images for the corresponding PMA mixing time of Solprene 411 and Solprene 1205 for CTTE Prototype Dyne 143A reveals that the 2.3wt% polymer-rich phase in CTTE Prototype Dyne 143A PMA is completely dispersed at 180 minutes, which is much shorter (about 25%) than the dispersion time in Solprene 411PMA and the same as the dispersion time required in Solprene 1205PMA. The reduction in particle size proves that the compatibility with asphalt is enhanced, which is consistent with the research results of LHLewandowski (1994), Rubber Chemistry and Technology, Rubber Reviews, Vol. 67, No. 3, pp. 447-480. Figure 7 Qualitative comparison of the images corresponding to 6 wt% PMA in Figure 1 reveals relatively similar mixing behavior, but with a longer dispersion time, the 6 wt% polymer-rich phase in CTTE Prototype Dyne 143A PMA is fully dispersed at 240 minutes, which is even much shorter (about 33%) than the dispersion time in Solprene 411PMA and the same dispersion time required in Solprene 1205PMA. Similar to Solprene 1205, the PMA dispersion performance of CTTE Prototype Dyne 143A is dependent on polymer concentration.

[0302] Reviewing Table 7, the results show that CTTE Prototype Dyne 143A PMA has a low viscosity at 135°C at 2.3 wt%, which is intermediate between the higher viscosity of Solprene 411PMA (about 30%) and the lower viscosity of Solprene 1205PMA (about 30%). Surprisingly, the viscosity of CTTE Prototype Dyne 143A PMA at 12 wt% at 160°C is also intermediate, but between the much higher (about 70%) viscosity of Solprene 411PMA and the much lower (about 10%) viscosity of Solprene 1205PMA. The dependence of PMA viscosity development on polymer concentration for CTTE Prototype Dyne 143A is similar to that of Solprene 1205. Low viscosity also provides advantages for mixing and compacting of hot mix asphalt for paving.

[0303] Figure 8 The maximum performance grade (AASHTO standard PG) temperature of several polymer modified asphalts (PMAs) prepared with 2.3 wt% polymer, monitored at different temperatures throughout the mixing process, is depicted. The reinforcing properties of CTTE Prototype Dyne 143A PMA mixed at 170, 180, and 190°C are compared to the commercial block copolymer Solprene 411PMA mixed at 185°C. Review Figure 8 , the results show that at every mixing temperature, even when mixed at a 15°C lower mixing temperature (170°C), the failure temperature (maximum performance grade temperature) of CTTE Prototype Dyne 143A PMA was higher than Solprene 411PMA throughout the mixing process. Surprisingly, CTTE Prototype Dyne 143APMA provides similar enhanced performance as Solprene 411PMA with significant cost and / or processing advantages.

[0304] In summary, the results described in Example 7 show that the new inversely tapered thermoplastic elastomer composition provides the new polymer modified asphalt CTTE Prototype Dyne 143A PMA with: a dependence of dispersion properties on polymer concentration similar to Solprene 1205; a dependence of viscosity development on polymer concentration similar to Solprene 1205; and surprisingly, enhanced properties similar to Solprene 411PMA and important cost and / or processing advantages. In paving and roofing membrane applications, the surprising combination of processability and enhanced properties of CTTE Prototype Dyne 143A PMA provides a very ideal balance for the asphalt modification industry. In addition to the outstanding enhanced properties of the resulting PMA mixture, the much lower viscosity of the asphalt formulation, in addition to helping to promote the dispersion of the polymer into the asphalt and improve the time required for mixing, also facilitates the processing, handling and application of the modified asphalt mixture by improving pumpability and / or reducing the energy required to apply the modified asphalt mixture and / or by improving thermal storage stability, even at lower temperatures. This also means important cost reductions and a more environmentally friendly process.

[0305] Example 8

[0306] Application of polymer modified asphalt (PMA) in road paving

[0307] The high Mw CTTE Prototype Dyne 143A described in Example 7 was used as an asphalt modifier or asphalt enhancer in polymer modified asphalt (PMA) for paving formulations. The procedure described in Example 2 was followed to prepare and characterize the CTTE Prototype Dyne 143A PMA formulations.

[0308] The CTTE Prototype Dyne 143A PMA results are shown in Table 8 below and demonstrate the enhanced performance of the novel inversely tapered thermoplastic elastomer composition as an asphalt modifier in paving at 2.3 wt%, 2.5 wt% and 2.8 wt% CTTE polymer content based on the total PMA blend. The CTTE Prototype Dyne 143A PMA enhanced performance was compared to PMA blends of two commercially available block copolymers, Solprene 411 and Solprene 1205.

[0309] Table 8

[0310] Performance of High Mw CTTE in Paving Asphalt Reinforcement

[0311]

[0312] Reviewing Table 8, it is surprising that the results show that CTTE Prototype Dyne 143A PMA has a high elastic response at 25°C at 2.5wt%, which is similar to Solprene 411PMA and much higher than Solprene 1205PMA (about 35%). It is also surprising that the CTTE Prototype Dyne 143A PMA mixture achieves a wide performance grade PG range at 2.3wt% and 2.8wt%, which is even wider than the range of Solprene 411PMA and Solprene1205PMA. In paving applications, CTTE Prototype Dyne 143A provides better PMA reinforcement and improved high temperature performance than Solprene411 and Solprene 1205, which translates into high resistance to plastic deformation, high fatigue resistance and lower thermal cracking.

[0313] Example 9

[0314] Application of polymer modified asphalt (PMA) in roofing and waterproofing membranes

[0315] The high Mw CTTE Prototype Dyne 143A described in Example 7 was used as an asphalt modifier or asphalt enhancer in polymer modified asphalt (PMA) for roofing and waterproofing membrane formulations. The CTTE Prototype Dyne 143A PMA formulations were prepared and characterized following the procedures described in Examples 2 and 6.

[0316] The CTTE Prototype Dyne 143A PMA results are shown in Table 9 below and demonstrate the enhanced performance of the novel inversely tapered thermoplastic elastomer composition as an asphalt modifier for roofing and waterproofing membranes at 6 wt% CTTE polymer loading with 20 wt% and 30 wt% lime filler loading based on the total PMA blend. The CTTE Prototype Dyne 143A PMA processing properties were compared to PMA blends of commercial block copolymer Solprene 411.

[0317] Table 9

[0318] Performance of high Mw CTTE in bitumen reinforcement of roofing and waterproofing membranes

[0319]

[0320] Reviewing Table 9, the results show that the low viscosity of CTTE Prototype Dyne 143A PMA loaded with 20 wt% lime filler at 160°C and 190°C is much lower (about 35-45%) than the viscosity of Solprene 411PMA at the same filler loading. In addition, CTTE Prototype Dyne 143A PMA loaded with a higher (about 50%) filler loading (30 wt% lime filler) develops a viscosity at 160°C and 190°C similar to Solprene 411PMA at 20 wt% filler loading. CTTE Prototype Dyne 143A provides better filled PMA processing properties than Solprene 411, which allows higher filler loading PMA formulations, thus allowing important cost reductions and higher deformation resistance for roofing, shingles and waterproofing membrane applications.

[0321] Example 10

[0322] Application of polymer modified asphalt (PMA) in roofing and waterproofing membranes

[0323] The high Mw CTTE Prototype Dyne 143A described in Example 7 was used as an asphalt modifier or asphalt enhancer in polymer modified asphalt (PMA) for roofing and waterproofing membrane formulations. The CTTE Prototype Dyne 143A PMA formulations were prepared and characterized following the procedures described in Examples 2 and 6.

[0324] The results for CTTE Prototype Dyne 143A PMA are shown in Table 10 below and demonstrate the enhanced performance of the novel inverse tapered thermoplastic elastomer composition as an asphalt modifier in roofing and waterproofing membranes at 4 wt% and 5 wt% CTTE polymer based on the total PMA blend. The CTTE Prototype Dyne 143A PMA enhanced performance was compared to a PMA blend of the commercial block copolymer Solprene 411.

[0325] Table 10

[0326] Performance of high Mw CTTE in bitumen reinforcement of roofing and waterproofing membranes

[0327]

[0328] Reviewing Table 10, the results show an improved balance between high temperature properties (softening point) and low temperature properties (cold bend) for the CTTE prototype Dyne 143A PMA, which is better at low temperatures and acceptable at high temperatures compared to Solprene 411PMA at the same (4wt%) polymer content. Surprisingly, the CTTE prototype Dyne 143APMA achieves an excellent balance between high temperature properties (softening point) and low temperature properties (cold bend) at about 20% higher polymer content (5wt%), which is better at low temperatures and similar at high temperatures compared to Solprene 411PMA prepared at a lower (4wt%) polymer content. The new high Mw CTTE prototype Dyne 143A provides improved PMA reinforcement properties over Solprene 411, which enables good processability at high temperatures and better flexibility (improved fracture resistance) at low temperatures in roofing, shingles and waterproofing membrane applications.

[0329] Embodiment 11

[0330] Application of polymer modified asphalt (PMA) in road paving

[0331] According to the teachings of the present invention, a low Mw inversely tapered thermoplastic elastomer composition was prepared in a 180 liter reactor system operated in batch or semi-batch mode under an inert nitrogen atmosphere. A low Mw CTTE Prototype Dyne 143C was obtained following the procedure described in Example 1 and used as an asphalt modifier or asphalt enhancer in a polymer modified asphalt (PMA) for paving formulations. A CTTE Prototype Dyne 143C PMA formulation was prepared and characterized following the procedure described in Example 2.

[0332] The results for CTTE Prototype Dyne 143C PMA are shown in Table 11 below and show the enhanced performance of the novel inversely tapered thermoplastic elastomer composition as an asphalt modifier in paving at 2.3 wt%, 2.5 wt% and 2.8 wt% CTTE polymer content based on the total PMA mixture. The processing and reinforcement properties of CTTE Prototype Dyne 143C PMA were compared with PMA mixtures of two commercial block copolymers, Solprene 1205 and Kraton D1192. The Solprene 1205 has been described in Example 7 and the Kraton D1192 is described as a fully sequential triblock copolymer high vinyl SBS with about 30 wt% total styrene as pure polystyrene blocks and no tapered properties.

[0333] Table 11

[0334] Performance of Low Mw CTTE in Paving Asphalt Reinforcement

[0335]

[0336] Reviewing Table 11, the results show that the CTTE prototype Dyne 143C PMA has a very low viscosity at 135°C at 2.3 wt%, which is surprisingly similar to the viscosity of the Solprene 1205 and Kraton D1192 PMA mixture. Even more surprisingly, the elastic response of the CTTE Prototype Dyne 143C PMA at 2.5 wt% at 25°C is higher (about 20-40%) than the mixture of Solprene 1205 and Kraton D1192 PMA. The CTTE prototype Dyne 143C is expected to provide a PMA viscosity development dependence on polymer concentration similar to the Solprene 1205 and Kraton D1192 PMA mixture, which is beneficial to the processing and handling of PMA concentrates in the asphalt industry, as well as the mixing and compaction of hot mix asphalt for paving.

[0337] Equally surprising is that the CTTE prototype Dyne 143C PMA blend achieves a wide performance grade PG range at 2.3wt% and 2.8wt%, which is the same as the performance grade PG range of Solprene 1205 and Kraton D1192 PMA blends. The new CTTE prototype Dyne 143C provides PMA with a similar balance of processability and enhanced properties to Solprene 1205 and Kraton D1192 PMA blends in paving applications, which translates into high resistance to plastic deformation, high fatigue resistance and lower hot cracking.

[0338] Example 12

[0339] Application of polymer modified asphalt (PMA) in road paving

[0340] The low Mw CTTE Prototype Dyne 143C described in Example 11 was used as an asphalt modifier or asphalt enhancer in polymer modified asphalt (PMA) for paving formulations. The CTTE Prototype Dyne 143C PMA formulation was prepared following the procedure described in Example 2. The bond strength was measured by using a TA.XTPlus texture analyzer from Stable Micro Systems under standard temperature and humidity laboratory conditions.

[0341] The CTTE Prototype Dyne 143C PMA results are shown in Table 12 below and demonstrate the enhanced performance of the novel inversely tapered thermoplastic elastomer composition as an asphalt modifier in paving at a CTTE polymer content of 2.3 wt% based on the total PMA blend. The CTTE Prototype Dyne 143C PMA enhanced performance was compared to PMA blends of two commercially available block copolymers, Solprene 411 and Solprene 1205.

[0342] Table 12

[0343] Performance of Low Mw CTTE in Paving Asphalt Reinforcement

[0344]

[0345] Reviewing Table 12, surprisingly, the results show an average bond strength for CTTE prototype Dyne 143C PMA that is very similar to Solprene 1205PMA and much higher (about 70%) than Solprene 411PMA. CTTE prototype Dyne 143C provides PMA reinforcement performance similar to Solprene 1205PMA blends with improved adhesion properties, an important feature for asphalt-aggregate surface interactions in paving applications.

[0346] Example 13

[0347] Application of polymer modified asphalt emulsion (PME) in road paving

[0348] The low Mw CTTE Prototype Dyne 143C described in Example 11 was used as an asphalt modifier or asphalt enhancer in a polymer modified asphalt emulsion (PME) for paving formulations. The CTTE Prototype Dyne 143C PME formulation was prepared according to the U.S. Standard Specification RS-1P and characterized following the procedure described in Example 3. The initial CTTE Prototype Dyne 143C PMA was mixed at 170°C before the emulsification process.

[0349] The results for the CTTE Prototype Dyne 143C PME are shown in Table 13 below and demonstrate the enhanced performance of the novel inversely tapered thermoplastic elastomer composition as an asphalt modifier in a paving emulsion at 3 wt% CTTE polymer dry basis content based on total PMA residues and a PG 64-22 base asphalt diluted with 5% aromatic diluent oil. The processing and reinforcing properties of the CTTE Prototype Dyne 143C PME were compared to PMEs of two commercial block copolymers Solprene 4318 and Solprene 1205 and a commercial high solids aqueous polymer dispersion, a 24 wt% styrene content SBR latex Butonal 4190 PME.

[0350] Table 13

[0351] Performance of Low Mw CTTE in Paving Asphalt Reinforcement

[0352]

[0353] Reviewing Table 13, the results show the low viscosity, excellent storage stability, and excellent screen residue of the polymer modified asphalt emulsion CTTE prototype Dyne 143C PME. Mixing the CTTE prototype Dyne 143C PMA at low temperature (170°C) prior to the emulsification process at 150°C provides important processing advantages by reducing the required PMA cooling time by half, from about 6-8 hours to about 3-4 hours. In addition, the results show that the polymer modified asphalt residue CTTE prototype Dyne 143C PMA has a high elastic response at 10°C and a good balance between high temperature properties (softening point) and low temperature properties (ductility). CTTE prototype Dyne 143C provides an improved property balance of PME processing performance and PMA reinforcement performance that is very competitive compared to PME prepared from commercially available polymers, and it also meets the US Standard Specification RS-1P used for PME paving applications such as chip seal, tack coat and cold mix. The improved bond strength of the CTTE prototype Dyne 143C PMA described in Example 12 is expected to provide polymer modified asphalt emulsions (PME) with the desired adhesion for surface treatments such as chip seal applications.

[0354] Embodiment 14

[0355] Preparation of reverse tapered thermoplastic elastomer (CTTE)

[0356] In Example 14, several novel inversely tapered thermoplastic elastomers (CTTE39-44) were prepared according to the method claimed in the present invention. The polymers CTTE39-44 are inversely tapered diblock A-[A / B] copolymers, wherein the A-[A / B] diblock is composed of a monovinyl aromatic homopolymer block A block which is a polystyrene block S and an inversely tapered copolymer block [A / B] which is a styrene / butadiene copolymer block [S / B], wherein inversely tapered means that the ratio of B to A in the [A / B] block near the A block is lower relative to the ratio of B to A far from the A block, and wherein in the inversely tapered diblock A-[A / B] copolymer, the vinyl content near the A block is higher relative to the vinyl content far from the A block.

[0357] These novel inverse tapered thermoplastic elastomer (CTTE39-44) compositions were characterized by GPC, 1H NMR and DSC methods to determine: weight average molecular weight and molecular weight distribution properties, such as peak molecular weight (Mp) and weight average molecular weight (Mw) of the linear diblock; microstructural properties, such as total styrene, block styrene and vinyl [A / B] block content; glass transition temperature (Tg) of the A / B inverse tapered copolymer block; and melt flow rate (MFI) of the CTTE inverse tapered thermoplastic composition. In addition, calculations for [A / B] block styrene and [A / B] block blockiness were also performed according to the method used in US2003 / 0176582A1 patent application published on September 18, 2003 by KRATON Polymers US LLC for characterizing the polymer middle or "B" block as Calc. Mid PSC and Calc. Mid Blocky. Tables 14-15 list the analytical characterization results and Table 16 lists the polymerization conditions for CTTE 39-44. A general procedure similar to that described in Example 1 is described below for preparing these novel inverse tapered thermoplastic elastomers (CTTE 39-44) and for controlling the monomer distribution in the anionic copolymerization of 1,3-butadiene (B) and styrene (S) in the presence of ditetrahydrofuryl propane (DTHFP) or tetrahydrofuran (THF) as a suitable polar modifier and randomizer for the styrene / butadiene [S / B] inverse tapered copolymer blocks. The abbreviations used for the polymerization conditions in Table 16 below are defined as follows: CHx = cyclohexane; STY = styrene; and BD = 1,3-butadiene.

[0358] According to the teachings of the present invention, the novel inversely tapered thermoplastic elastomer (CTTE 39-44) composition of the present invention is prepared in a 5.4 liter reactor system operated in a batch and / or semi-batch mode under an inert nitrogen atmosphere. Immediately before being added to the reactor system, the solvent and monomer are fully purified by passing them through a set of columns filled with alumina and molecular sieves to reduce their moisture content to a maximum of 5 ppm. For the first polymerization step, an appropriate amount of purified solvent (CHx) is charged to the reactor and heated to an initial reaction temperature (Ti) of about 50°C to about 55°C. Once Ti is reached, a suitable polar modifier (randomizer) such as ditetrahydrofuranyl propane (DTHFP) or tetrahydrofuran (THF) is added to the reactor, followed by a first addition of a monovinyl aromatic monomer (first STY) of about 10-30% by weight of the total monomer mixture. The reaction mixture is stabilized at Ti, and then n-butyl lithium or another suitable initiator in a suitable solvent solution is added directly to the reactor mixture, which contains at least the amount of polar modifier required to effectively initiate anionic polymerization of the living polystyrene block. The amount of initiator is stoichiometrically calculated as described in the literature to form a single block with the desired molecular weight and to compensate for residual impurities. The first polymerization step is then carried out adiabatically until complete conversion to form a monovinyl aromatic homopolymer block A with a peak molecular weight Mp of about 6,000 to a target value of about 25,000.

[0359] For the second polymerization step, both monomer additions are started simultaneously for CTTE39-44, a second monovinyl aromatic monomer (second STY) of about 7.5 to about 10 wt% of the total monomer mixture is added rapidly into the reactor at a specified dosage rate of about 33 to 46 g / min during a predetermined dosage time of about 1 minute, and a conjugated diene monomer (BD) of about 60.3 to about 82.5 wt% of the total monomer mixture is added slowly into the reactor at a specified dosage rate of about 92 to about 127 g / min during a predetermined dosage time of about 3 minutes. These monomer additions are performed in a programmed batch and / or semi-batch mode, and the amount of polar modifier (randomizer) is adjusted from about 0.0069 wt% to about 0.0684 wt% of the total reaction mixture to promote the formation of a statistically distributed tapered S / B copolymer block that gradually changes (1,2-addition) in composition and vinyl microstructure along the copolymer chain. The second polymerization step is then carried out adiabatically until complete conversion and the final peak temperature (Tp) is increased to about 102.4 to about 116.7°C, thereby forming a reverse tapered copolymer [A / B] block and thereby obtaining a living reverse tapered A-[A / B] diblock copolymer having a target value of a peak molecular weight Mp of about 125,000 to about 230,000.

[0360] Finally, the living polymer chains are terminated by adding a 10 mol% excess of the stoichiometric amount of a suitable alcohol to the final reaction mixture.

[0361] Tables 14 and 15 list the analytical characterization results of the novel inversely tapered thermoplastic elastomer composition CTTE 39-44. All molecular weights (Mp and Mw) are given in units of 1000 (k) and are calculated by GPC relative to polystyrene standards. The peak molecular weight Mp of the monovinyl aromatic homopolymer block A or polystyrene block of CTTE39-44 is about 6.1 to about 22.1 kg / mol. The peak molecular weight Mp of the A-[A / B] diblock copolymer or S-[S / B] styrene-butadiene diblock copolymer of CTTE 39-44 is about 125 to about 230 kg / mol. The weight average molecular weight Mw of CTTE 39-44 is about 125 to about 223 kg / mol. Based on the total amount of butadiene units, the vinyl [A / B] block content of CTTE 39-44 is about 34.0 to about 63.0 weight %. The glass transition temperature of the [A / B] inverse tapered copolymer block of CTTE 40-43 is from about -68.5 to about -43.5°C. The melt flow rate (MFI) of the CTTE 42-43 composition is from about 19.5 to about 29.2 g / 10 min. The following contents were determined by NMR of CTTE 39-44: total styrene based on the total copolymer is from about 18.8 to about 41.8 weight percent; block styrene based on the total styrene units is from about 49.2 to about 83.0 weight percent; [A / B] block styrene based on the [A / B] block copolymer is from about 6.7 to about 20.1 weight percent, and [A / B] block blockiness based on the [A / B] block styrene units is from about 6.5 to about 27.2 weight percent.

[0362] Table 14 Reverse tapered thermoplastic elastomer composition

[0363]

[0364] a Molecular weight peak and average relative to PS standards;

[0365] b RMN 1 H300 MHz, vinyl based on total butadiene units, wt%;

[0366] C Glass transition temperature (inflection point) by DSC @ 10 °C / min;

[0367] Table 15

[0368] NMR results of reverse tapered thermoplastic elastomer

[0369]

[0370] a RMN 1 H 300 MHz, total styrene based on total copolymer, wt.%;

[0371] b RMN 1 H 300 MHz, block styrene based on total styrene units, wt.%;

[0372] c Calculated [A / B] block styrene, based on [A / B] block copolymer, wt.%;

[0373] d Calculated [A / B] block blockiness, based on [A / B] block styrene units, wt%.

[0374] Table 16

[0375] Reverse tapered thermoplastic elastomer method

[0376]

[0377]

[0378] a wt% of total reaction mixture

[0379] b wt% of total monomer mixture

[0380] Embodiment 15

[0381] Application of polymer modified asphalt (PMA) in road paving

[0382] High Mw inversely tapered thermoplastic elastomer A-[A / B] or S-[S / B] diblock compositions with different vinyl [A / B] block (wt %) contents, CTTE D-170A and CTTE D-170B in Table 17, were prepared with medium vinyl and high vinyl, respectively, as described in Example 14 and used as asphalt modifiers or asphalt enhancers in polymer modified asphalt (PMA) for road paving formulations. All CTTE D-170A and CTTE D-170B PMA formulations were prepared and characterized according to the procedure described in Example 2, with the following additional steps: CTTE D-170A PMA with a polymer content of 3.0 wt% and CTTE D-170B PMA with a polymer content of 3.0 wt% were added as sulfur crosslinkers and mixed at 2500 RPM and 190°C + / - 5°C for about 60-120 minutes; CTTE D-170A PMA with a polymer content of 6.0 wt% and CTTE D-170B PMA with a polymer content of 6.0 wt% were added as sulfur crosslinkers and mixed at 2500 RPM and 190°C + / - 5°C for about 60-120 minutes; The PMA was mixed at 2500 RPM and 190°C + / - 5°C in the absence of a crosslinking agent (without added sulfur) for about 120-180 minutes; and the initially prepared mixture having a polymer content of 6.0 wt% was diluted with additional neat asphalt, mixed for about 120-180 minutes, and then sulfur was added as a crosslinking agent and mixing was continued at 2500 RPM and 190°C + / - 5°C for about 60-120 minutes to prepare diluted CTTE D-170A PMA and diluted CTTE D-170B PMA.

[0383] The CTTE polymer modified asphalt (CTTE D-170A PMA and CTTE D-170B PMA) results are given in Table 17 below and show the enhanced performance of the new inverse tapered thermoplastic elastomer diblock compositions as asphalt modifiers for paving at 3.0, 3.0 dilution and 6.0 wt % CTTE polymer content based on the total PMA mixture, compared to Solprene 1205, a commercially available low vinyl conventional tapered diblock copolymer.

[0384] Table 17

[0385] Performance of high Mw CTTE in asphalt reinforcement for road paving

[0386]

[0387] Looking back at Table 17, at the same polymer content and sulfur addition, the polymer modified asphalt results of CTTE D-170A PMA and CTTE D-170B PMA show higher viscosity, lower penetration, higher softening point, higher elastic recovery and a wider performance grade (PG) range than the polymer modified asphalt results of S-1205PMA, respectively. In general, CTTE D-170A PMA and CTTE D-170B PMA show an excellent balance between high and low temperature properties, as well as the expected and predictable polymer modified asphalt with high stiffness (i.e., rigidity) and high elastic behavior. Specifically, for asphalt formulations with lower polymer content (i.e., 3wt%), CTTE D-170A PMA and CTTE D-170BPMA show a combination of high elastic response and high softening point, as well as acceptable viscosity by PMA standards (i.e., for paving applications, the dynamic viscosity at 135°C is about 500 to 3000 cP, and ideally 1000 to 2000 cP). The CTTE D-170A PMA and CTTE D-170B PMA compositions provide a desired balance between processability and enhanced performance, and provide the potential for cost improvements to reduce polymer content without reducing other properties below S-1205PMA performance at the same polymer content and sulfur addition. In addition, the CTTE D-170A PMA and CTTE D-170B PMA compositions at 3 wt% polymer content and 2 wt% sulfur addition provide improvements in softening point, elastic recovery, and PG in the absence of a crosslinker (no sulfur addition) without the high viscosity of the CTTE D-170A PMA and CTTE D-170B PMA compositions at 6 wt% polymer content. Surprisingly, the dilution process from 6 wt% to 3 wt% of the CTTE D-170A PMA dilution and CTTE D-170B PMA dilution compositions provided improvements in softening point, elastic recovery, and PG over the addition of 2 wt% sulfur when directly compared to the CTTE D-170A PMA and CTTE D-170B PMA compositions at the same 3 wt% polymer content and 2 wt% sulfur addition. The improved reinforcing properties of the CTTE D-170A PMA and CTTE D-170B PMA compositions are attributed not only to the high molecular weight, but also to the characteristics of the inverse tapered thermoplastic elastomer A-[A / B] or S-[S / B] diblock compositions (i.e., low [A / B] block blockiness and high vinyl [A / B] blocks).

[0388] The results for polymer modified asphalt of CTTE D-170A PMA, CTTE D-170B PMA, diluted CTTE D-170A PMA and diluted CTTE D-170B PMA at 3 wt % polymer content in the presence of a crosslinker (i.e., 2.0 wt % sulfur addition) showed: Brookfield viscosity of 1715 to 3350 cP at 135°C; needle penetration of 43 to 46 dmm at 25°C; Ring and Ball softening point of 72 to 88°C; elastic recovery of 56 to 62% measured by torsion at 25°C; and elastic recovery of 88 to 90% measured by extensometer at 25°C.

[0389] In the absence of a crosslinking agent (i.e., no added sulfur), the polymer-modified asphalt results of CTTE D-170A PMA and CTTE D-170B PMA at 6.0 wt% polymer content showed: a dynamic viscosity at 135°C of less than 6000 cP, a preferred dynamic viscosity at 135°C of less than 5500 cP, and a most preferred dynamic viscosity at 135°C of less than 5000 cP; a softening point greater than 70°C, a preferred softening point greater than 75°C, and a most preferred softening point greater than 80°C; an elastic recovery at 25°C measured by torsion of greater than 35%, a preferred elastic recovery at 25°C measured by torsion of greater than 40%, and a most preferred elastic recovery at 25°C measured by torsion of greater than 45%; and a performance rating wider than 76-10, a preferred performance rating wider than 82-10, and a most preferred performance rating wider than 88-10.

[0390] In the presence of a crosslinker (i.e., 2.0 wt% sulfur addition), CTTE D-170A PMA and CTTE D-170B PMA at 3.0 wt% polymer content, and diluted CTTE D-170A PMA and diluted CTTE D-170B PMA at 3.0 wt% polymer content The results of the polymer-modified asphalt of PMA show: the dynamic viscosity at 135°C is lower than 4000cP, the preferred dynamic viscosity at 135°C is lower than 3500cP, and the most preferred dynamic viscosity at 135°C is lower than 3000cP; the softening point is greater than 60°C, the preferred softening point is greater than 65°C, and the most preferred softening point is greater than 70°C; the elastic recovery at 25°C measured by torsion is greater than 45%, the preferred elastic recovery at 25°C measured by torsion is greater than 50%, and the most preferred elastic recovery at 25°C measured by torsion is greater than 55%; and the elastic recovery at 25°C measured by an extensometer is greater than 75%, the preferred elastic recovery at 25°C measured by an extensometer is greater than 80%, and the most preferred elastic recovery at 25°C measured by an extensometer is greater than 85%.

[0391] Example 16

[0392] Application of polymer modified asphalt (PMA) in road paving

[0393] Low Mw inversely tapered thermoplastic elastomer A-[A / B] or S-[S / B] diblock compositions with high vinyl [A / B] block (wt%) content, CTTE D-170C in Tables 18 and 19, were prepared as described in Example 14 and used as asphalt modifiers or asphalt enhancers in polymer modified asphalt (PMA) for paving formulations. All CTTE D-170C PMA formulations were prepared and characterized according to the procedure described in Example 2. CTTE D-170C PMA formulations with polymer contents of 3.5, 4.5, and 5.0 wt% in the absence of a crosslinking agent (i.e., no sulfur added) are shown in Table 18. For the CTTE D-170C PMA formulations with polymer contents of 3.5, 4.5, and 5.0 wt% presented in Table 19, an additional step of adding sulfur as a crosslinking agent and mixing at 2500 RPM and 190°C + / - 5°C for about 60-120 minutes was performed.

[0394] The CTTE polymer modified asphalt (CTTE D-170C PMA) results are given in Tables 18 and 19 below and show the enhanced performance of the novel inversely tapered thermoplastic elastomer diblock composition as an asphalt modifier for paving at 3.5, 4.5 and 5.0 wt % CTTE polymer content based on the total PMA mixture compared to Solprene 1205, a commercially available low vinyl normal tapered diblock copolymer, in the absence of a crosslinker (i.e., no added sulfur) and in the presence of a crosslinker (i.e., 2 wt % sulfur added based on the total polymer).

[0395] Table 18

[0396] Asphalt reinforcement for paving with low to medium Mw CTTE performance

[0397]

[0398] Table 19 Properties of low-Mw CTTE in asphalt reinforcement for paving

[0399]

[0400] Reviewing Table 18, the polymer modified asphalt results of CTTE D-170C PMA formulations at 3.5, 4.5 and 5.0 wt% polymer contents in the absence of a crosslinker (i.e., no added sulfur) show similar viscosity, lower penetration, higher softening point, higher ductility, higher elastic recovery, lower phase separation and similar performance grade (PG) ranges, respectively, compared to the polymer modified asphalt results of S-1205PMA at the same polymer content. In general, CTTE D-170C PMA shows an excellent balance between high and low temperature properties, as well as the expected and predictable polymer modified asphalt with high stiffness (i.e., rigidity) and high elastic behavior. Specifically, for asphalt formulations with higher polymer contents (i.e., 4.5 and 5.0 wt%), the CTTE D-170C PMA exhibits a combination of high elastic response and high softening point, with low viscosities expected for PMA standards (i.e., dynamic viscosity at 135°C is about 500 to 3000 cP, and desirably 1000 to 2000 cP for paving applications). The CTTE D-170C PMA compositions provide a desired balance between processability and enhanced performance, provide the potential for cost improvements to reduce polymer content without sacrificing other properties below the performance of S-1205PMA at the same polymer content, and provide the potential for improved performance by curing PMA compositions at elevated temperatures for longer mix times in the absence of crosslinking agents (i.e., without added sulfur), particularly for high vinyl, inverse tapered diblock compositions.

[0401] In the absence of a crosslinking agent (i.e., no added sulfur), the polymer-modified asphalt results of CTTE D-170C PMA formulations at polymer contents of 3.5, 4.5 and 5.0 wt% showed: Brookfield viscosity at 135°C of 823 to 1151 cP; needle penetration at 25°C of 45 to 52 dmm; Ring and Ball softening point of 58 to 69°C; ductility at 25°C of 59 to 110 cm; elastic recovery at 25°C measured by torsion of 33 to 40%; elastic recovery at 25°C measured by extensometer of 54 to 55%; elastic recovery at 10°C measured by extensometer of 25 to 30%; and phase separation of 0.1 to 2.0°C.

[0402] In the absence of a crosslinking agent (i.e., without added sulfur), the polymer-modified asphalt results of the CTTE D-170C PMA formulations at 3.5, 4.5, and 5.0 wt% polymer contents showed: a dynamic viscosity at 135°C of less than 3000 cP, preferably a dynamic viscosity of less than 2000 cP, and most preferably a dynamic viscosity of less than 1200 cP; a softening point of greater than 50°C, preferably a softening point of 55°C, and most preferably a softening point of 60°C; an elastic recovery at 25°C of greater than 45% as measured by an extensometer, a preferred elastic recovery at 25°C of greater than 50% as measured by an extensometer, and most preferably a elastic recovery at 25°C of greater than 60% as measured by an extensometer. Elastic recovery greater than 55%; elastic recovery at 10°C measured by an extensometer greater than 20%, preferably elastic recovery at 10°C measured by an extensometer greater than 25%, and most preferably elastic recovery at 10°C measured by an extensometer greater than 30%; ductility greater than 50 cm at 25°C, preferably ductility greater than 55 cm at 25°C, and most preferably ductility greater than 60 cm at 25°C; and phase separation below 5.0°C, preferably phase separation below 2.0°C, and most preferably phase separation below 1.0°C.

[0403] In Table 19, the polymer modified asphalt results for CTTE D-170C PMA formulations at 3.5, 4.5, and 5.0 wt% polymer contents in the presence of a crosslinker (i.e., 2 wt% sulfur addition) show higher viscosity, lower penetration, higher softening point, higher ductility, higher elastic recovery, similar phase separation, and similar performance grade (PG) ranges, respectively, compared to the polymer modified asphalt results for S-1205PMA at the same polymer content. In general, the CTTE D-170C PMA compositions formulated in the presence of a crosslinker show an excellent balance between high and low temperature properties, as well as the expected and predictable polymer modified asphalt with higher stiffness (i.e., rigidity) and greater elastic behavior, compared to the CTTE D-170C PMA compositions formulated in the absence of a crosslinker at the same polymer content. Specifically, for asphalt formulations with higher polymer content (i.e., 4.5 and 5.0 wt%), CTTE D-170C PMA exhibits a combination of high elastic response and high softening point with low viscosity expected by PMA standards (i.e., dynamic viscosity at 135°C is about 500 to 3000 cP, and desirably 1000 to 2000 cP for paving applications). The CTTE D-170C PMA composition provides a desirable balance between processability and reinforcing properties, and offers potential cost improvements to reduce polymer content without sacrificing other properties below S-1205PMA performance at the same polymer content. Surprisingly, the CTTE D-170C PMA composition formulated in the absence of a crosslinking agent provides an improvement in reinforcing properties (i.e., a higher elastic response and a higher softening point) that is more pronounced relative to S-1205PMA at the same polymer content than the CTTE D-170C PMA composition formulated in the presence of a crosslinking agent, and maintains the upper temperature limit of the performance grade PG without reducing processability (i.e., increasing viscosity). The improvement in reinforcing properties of the CTTE D-170C PMA composition is attributed to the characteristics of the inversely tapered thermoplastic elastomer A-[A / B] or S-[S / B] diblock composition (i.e., low [A / B] block blockiness and high vinyl [A / B] blocks).

[0404] The polymer-modified asphalt results of CTTED-170C PMA formulations at 3.5, 4.5 and 5.0 wt% polymer contents in the presence of a crosslinker (i.e., 2 wt% sulfur was added) showed: Brookfield viscosity of 968 to 1694 cP at 135°C; needle penetration of 42 to 44 dmm at 25°C; Ring and Ball softening point of 64 to 83°C; ductility of 71 to 91 cm at 25°C; elastic recovery at 25°C measured by torsion of 55 to 70%; elastic recovery at 25°C measured by extensometer of 74 to 83%; elastic recovery at 10°C measured by extensometer of 46 to 55%; and phase separation of 0.7 to 1.4°C.

[0405] In the presence of a crosslinking agent (i.e., 2 wt% sulfur was added), the polymer modified asphalt of the CTTED-170C PMA formulation at 3.5, 4.5 and 5.0 wt% polymer content showed: a dynamic viscosity at 135°C of less than 3000 cP, preferably a dynamic viscosity of less than 2500 cP, and most preferably a dynamic viscosity of less than 1750 cP; a softening point of greater than 55°C, preferably a softening point of 60°C, and most preferably a softening point of 65°C; an elastic recovery at 25°C measured by an extensometer of greater than 60%, preferably an elastic recovery at 25°C measured by an extensometer of greater than 65%, and most preferably an elastic recovery at 25°C measured by an extensometer of less than 10%. The invention relates to a method of manufacturing a composite material of the present invention and the method for manufacturing the composite material of the present invention. The method comprises: a first step of manufacturing the composite material of the present invention and a second step of manufacturing the composite material of the present invention. The first step of manufacturing the composite material of the present invention comprises: a first step of manufacturing the composite material of the present invention and a second step of manufacturing the composite material of the present invention; a second step of manufacturing the composite material of the present invention and a second step of manufacturing the composite material of the present invention; ...

[0406] Embodiment 17

[0407] Application of polymer modified asphalt (PMA) in roofing and waterproofing membranes

[0408] A low Mw inversely tapered thermoplastic elastomer A-[A / B] or S-[S / B] diblock composition with high vinyl [A / B] block (wt%) content, CTTE D-170C in Table 20, prepared as described in Example 14, was used as an asphalt modifier or asphalt enhancer in polymer modified asphalt (PMA) formulations for roofing and waterproofing membrane applications. The CTTE D-170C PMA formulations were prepared and characterized according to the procedures described in Example 2 and Example 6, respectively. For CTTE D-170C, additional mixing time of about 60-120 minutes was performed at 2500 RPM and 190°C + / - 5°C.

[0409] The CTTE D-170C / S-411 (50 / 50) PMA results are given in Table 20 below and show the enhanced performance of the new inverse tapered thermoplastic elastomer diblock composition as an asphalt modifier for roofing membranes when compared to Solprene 1205, a commercially available low vinyl, conventional tapered diblock copolymer, at a polymer content of 8.0 wt% based on the total PMA mixture. The CTTE D-170C PMA was prepared as a 50 / 50 weight blend with two commercially available block copolymers, Solprene 411 and Solprene 1205. Solprene 411 is a multi-arm, highly coupled block copolymer (also known as a radial SBn thermoplastic elastomer) with a total styrene content of about 30 wt% as a pure block and no tapered properties. Solprene 1205 is a conventional tapered diblock B / SS copolymer (also known as graduated SBR) having a total styrene content of about 25 wt% and a block styrene content of about 17.5 wt%.

[0410] Table 20 Properties of bitumen-reinforced low-Mw CTTE for roofing and waterproofing membranes

[0411]

[0412] Reviewing Table 20, the CTTE D-170C / S-411 (50 / 50) PMA results show lower viscosity, similar penetration, lower softening point, and similar low flexibility, as well as an excellent balance between high and low temperature performance, compared to the polymer modified asphalt results of S-411 / S-1205 (50 / 50) PMA. The CTTE D-170C / S-411 (50 / 50) PMA composition provides a very desirable balance between processability and enhanced performance. In addition to the outstanding enhanced performance of the resulting PMA mixture, the much lower viscosity of the asphalt formulation, in addition to helping to improve flow properties, also promotes the dispersion of polymers into the asphalt and reduces the time required for mixing, even at lower temperatures, by improving pumpability and / or reducing the energy required for application to facilitate the processing, handling and application of roof membranes prepared with modified asphalt mixtures. This also means important cost reductions and a more environmentally friendly process.

[0413] The CTTE D-170C / S-411 (50 / 50) PMA results showed that the Brookfield viscosity at 180°C was about 809 cP; the Brookfield viscosity at 190°C was about 759 cP; the needle penetration at 25°C was about 38 dmm; the Ring and Ball softening point temperature was about 106°C; and the BDA cold bend temperature was about -12°C.

[0414] Embodiment 18

[0415] Application of polymer modified asphalt (PMA) in road paving

[0416] A low Mw inversely tapered thermoplastic elastomer (A-[A / B])2-X or (S-[S / B])2-X linear composition having a high vinyl [A / B] block (wt %) content, CTTE D-149C in Table 21, was prepared by partial coupling as described in Example 4 and used as an asphalt modifier or asphalt enhancer in polymer modified asphalt (PMA) for paving formulations. CTTE D-149C PMA formulations were prepared and characterized according to the procedure described in Example 2, with the following additional steps: CTTE D-149C PMA formulations having polymer contents of 3.0 and 6.0 wt% were prepared in the absence of a cross-linking agent (i.e., no added sulfur); a diluted CTTE D-149C PMA formulation having a polymer content of 3.0 wt% was prepared in the absence of a cross-linking agent (i.e., no added sulfur) by diluting the mixture initially prepared at a polymer content of 6.0 wt% with additional neat asphalt and continuing mixing at 2500 RPM and 190°C + / - 5°C for approximately 120-180 minutes.

[0417] The CTTE polymer modified asphalt (CTTE D-149C PMA) results are given in Table 21 below and show the enhanced performance of the linear novel inversely tapered thermoplastic elastomer with high vinyl composition as an asphalt modifier for paving at CTTE polymer content of 3.0, 3.0 dilution and 6.0 wt % based on the total PMA mixture when compared to CTTE D-143C, a low Mw inversely tapered thermoplastic elastomer (A-[A / B])nX or (S-[S / B])nX radial composition with medium vinyl [A / B] block (wt %) content prepared by partial coupling as described in Example 1. CTTE D-143C PMA with 3.0 wt% and 6.0 wt% polymer contents were prepared and characterized according to the procedure described in Example 2, and CTTE D-143C PMA diluted with 3.0 wt% polymer content was prepared by diluting the mixture initially prepared with 6.0 wt% polymer content with additional neat asphalt and continuing mixing at 2500 RPM and 190°C + / - 5°C for about 120-180 minutes. CTTE D-143C PMA with 3.0 wt% and 6.0 wt% polymer content and CTTE D-143C PMA diluted with 3.0 wt% polymer content had a small amount of sulfur (i.e., 0.5 wt% based on total polymer) added as a crosslinking agent to minimize phase separation and were mixed at 2500 RPM and 190°C + / - 5°C for an additional 60-120 minutes.

[0418] Table 21 Performance of low Mw CTTE in asphalt reinforcement for paving

[0419]

[0420] Reviewing Table 21, the polymer modified asphalt results of CTTE D-149C PMA at the same polymer content show lower viscosity, lower needle penetration, higher softening point, lower ductility, lower elastic recovery measured by torsion, higher elastic recovery measured by extensometer, varied phase separation, and varied performance grade (PG) ranges, respectively, than the polymer modified asphalt results of CTTE D-143C PMA. In general, CTTE D-149C PMA and CTTE D-143C PMA show an excellent balance between high and low temperature properties, as well as the expected and predictable polymer modified asphalt with high stiffness (i.e., rigidity) and high elastic behavior. For all formulations, CTTE D-149C PMA and CTTE D-143C PMA both exhibit a combination of high elastic response (i.e., elastic recovery at 25°C as measured by an extensometer) and high softening point, with desirable viscosities for CTTE D-149C at polymer contents of 3.0 and 6.0 wt%, and acceptable viscosities for CTTE D-143C PMA at polymer contents of 3.0 wt%, according to PMA standards (i.e., dynamic viscosity at 135°C of about 500 to 3000 cP, and ideally 1000 to 2000 cP for paving applications). The CTTE D-149C PMA and CTTE D-143C PMA compositions provide a desirable balance between processability and reinforcing properties. In addition, 3.0 and 6.0 wt% polymer content CTTE D-149C PMA compositions formulated in the absence of a crosslinker (i.e., no added sulfur) provide further improvements in viscosity, softening point, elastic recovery as measured by a ductometer, or PG relative to the corresponding CTTE D-143C PMA compositions, as well as a lower increase in viscosity (i.e., 2-fold) from 3.0 to 6.0 wt% polymer content. Surprisingly, the dilution process of the CTTE D-149C PMA dilution composition from 6 wt% to 3 wt% in the absence of a crosslinker (i.e., no added sulfur) provides similar viscosity, softening point, elastic recovery as measured by a ductometer, and PG; lower penetration and ductility; and virtually no phase separation when directly compared to the CTTE D-149C PMA composition at the same 3 wt% polymer content. The improvements in processability and reinforcement properties of the CTTE D-149C PMA and CTTE D-143C PMA compositions are attributed to the properties of the inversely tapered thermoplastic elastomer (A-[A / B])2-X or (A-[A / B])nX partially coupled compositions (i.e., low [A / B] block and [A / B]nX midblock blockiness and high vinyl [A / B] block and [A / B]nX midblock), respectively.

[0421] The results for polymer modified asphalt of CTTE D-143CPMA at 3.0 and 6.0 wt% polymer content in the presence of a crosslinker (i.e., 0.5 wt% sulfur addition) showed: Brookfield viscosity at 135°C was 2970 to 9340 cP; needle penetration at 25°C was 45 to 48 dmm; ring and ball softening point was 58 to 78°C; ductility at 25°C was 510 to 150 cm; elastic recovery at 25°C measured by torsion was 46 to 74%; elastic recovery at 25°C measured by extensometer was 71 to 76%; phase separation was 0.3 to 0.5°C; and performance grade PG was 70-22 to 76-16.

[0422] In the absence of a crosslinker (i.e., no added sulfur), the polymer-modified asphalt results of CTTED-149C PMA at 3.0 and 6.0 wt% polymer content showed: Brookfield viscosity at 135°C was 915 to 2206 cP; needle penetration at 25°C was 33 to 44 dmm; Ring and Ball softening point was 60 to 82°C; ductility at 25°C was 50 to 145 cm; elastic recovery at 25°C measured by torsion was 33 to 52%; elastic recovery at 25°C measured by extensometer was 78 to 93%; phase separation was 0.1 to 13°C; and performance grade PG was 70-16 to 82-16.

[0423] In the absence of a crosslinking agent (i.e., no added sulfur), the results for CTTED-149C PMA polymer-modified asphalt at 3.0 and 6.0 wt% polymer content showed: a dynamic viscosity at 135°C of 500 to 3000 cP, with a preferred range of 750 to 2500 cP, and a most preferred range of 915 to 2206 cP; an elastic recovery at 25°C measured by an extensometer of 50 to 98%, with a preferred range of 65 to 95%, and a most preferred range of 78 to 93%; and a phase separation of 0.1 to 13°C, with a preferred range of 0.1 to 1.0°C, and a most preferred range of 0.1 to 0.2°C.

[0424] In the absence of a crosslinking agent (i.e., no added sulfur), the polymer-modified asphalt results of CTTE D-149C PMA at 6.0 wt% polymer content showed: a dynamic viscosity at 135°C of less than 3000 cP, a preferred dynamic viscosity of less than 2500 cP, and a most preferred dynamic viscosity of less than 2250 cP; an elastic recovery at 25°C measured by an extensometer of greater than 75%, a preferred elastic recovery at 25°C measured by an extensometer of greater than 80%, and a most preferred elastic recovery at 25°C measured by an extensometer of greater than 90%; and a phase separation of less than 13°C, a preferred phase separation of less than 1.0°C, and a most preferred phase separation of less than 0.2°C.

[0425] In the absence of a crosslinking agent (i.e., no added sulfur), the polymer-modified asphalt results of CTTE D-149C PMA at 3.0 wt% polymer content and diluted CTTE D-149C PMA at 3.0 wt% polymer content showed: a dynamic viscosity at 135°C of less than 2000 cP, preferably less than 1500 cP, and most preferably less than 1000 cP; an elastic recovery at 25°C measured by an extensometer of greater than 50%, preferably greater than 65% at 25°C measured by an extensometer, and most preferably greater than 75% at 25°C measured by an extensometer; and a phase separation of less than 13°C, preferably less than 1.0°C, and most preferably less than 0.2°C.

[0426] Embodiment 19

[0427] Adhesives in tapes and labels

[0428] Test methods for properties of hot melt pressure sensitive adhesives

[0429] Dynamic mechanical analysis (DMA) method was performed to study the rheological properties of hot melt adhesives (before coating and without backing) using TA Instruments ARG2 rheometer with parallel plate geometry and automatic strain mode. The diameter of the plate was 8 mm and the gap was 2.000 mm. The frequency was 10 rad / s and the heating rate was 3 ° C / min. The maximum strain was set to 1.0%. Rheological data are very repeatable, and the uncertainty of glass transition is about ± 0.5 ° C. Rheological experiments can predict structure-performance relationships and final adhesive properties. These include the first tan δ maximum (tan δmax) temperature, which is a measure of the Tg of the rubber matrix. In addition, the tan δ maximum (tan δmax) peak height indicates how much energy the adhesive can dissipate. The storage modulus G' at room temperature (25 ° C) was also recorded to quantify the compliance of the adhesive at the applied temperature. In addition, the G′ modulus was analyzed to satisfy the Dahlquist criterion of 300,000 Pa for measuring quick tack (i.e., the Dahlquist temperature T Dahlquist ) temperature. Finally, the third crossover temperature is measured. The third crossover temperature (tan δ = 1) is a temperature close to the Tg of the glassy polystyrene domain, at which the storage modulus and loss modulus are equal (e.g., the same magnitude), so tan δ is equal to 1. The third crossover temperature (tan δ = 1) is the temperature at which the adhesive begins to flow and loses its cohesive strength, which can be related to the Ring and Ball Softening Point Temperature (RBSPT) and / or the Shear Adhesion Failure Temperature (SAFT).

[0430] The processability and reinforcement properties of hot melt adhesives were measured by the following standardized methods: a) Rolling Ball Tack Test according to PSTC-6. In this test, a 11.1 mm diameter ordinary steel ball is rolled down a bench top ramp onto a 2 inch by 15 inch tape. The distance the ball travels along the tape is recorded. The less the ball rolls down the tape, the stickier the adhesive. The ramp is a Cheminstruments Rolling Ball Tack Tester; b) Loop Tack Test according to PSTC-16 on a Cheminstruments Loop Tack Tester. The crosshead displacement rate is 5 mm / s. A 1 inch by 5 inch tape is used in the experiment. The free loop of the tape that is not restrained by the clamp is 75 mm long. The maximum force per unit width of the sample is recorded. The initial height measured from the bottom of the clamp to the substrate surface is 50 mm. The maximum displacement is 44 mm, and the dwell time at the maximum displacement is 1 s; c) 180° peel test is performed according to PSTC101 to determine the peel energy or peel force per unit width: Peel Adhesion Test Method for Pressure-Sensitive Tapes A-Single Coated Tape, Peel Adhesion at 180° Angle. Rectangular strips with dimensions of 1 inch by 12 inches are tested using a universal testing machine (UTM) at a crosshead displacement rate of 5.08 mm / s (i.e., 12 in / min); d) Lap shear strength measurements are performed at 23°C and -25°C according to the PSTC method. These experiments are performed to measure the cohesive or shear properties of the adhesive at room temperature and low temperature / freezing temperature after the adhesive is applied to two wood test specimens and joined together by pressing them together at room temperature with a standard force for a predetermined time. Rectangular specimens measuring 1 inch by 3 inches were tested using a universal testing machine (UTM) at a crosshead displacement rate of 5.08 mm / s (i.e., 12 in / min); e) Holding force measurements were performed using a Cheminstruments Bank Shear Tester according to the PSTC-107 method, 180° shear adhesion of pressure-sensitive tapes. These experiments were performed to measure the room temperature cohesive or shear properties of the tape. Instead of the 25 mm by 25 mm contact area described in PSTC-107, a 0.5 inch by 0.5 inch area of ​​pressure-sensitive tape (PSAT) was used. The PSAT was bonded to a stainless steel specimen using a standard 2 kg roller and a 1 kg mass was suspended from the tape. The time (min) to adhesive failure was recorded as the holding force; f) The tensile properties of the hot melt adhesive were measured on a 0.394 inch thick, 3.0 inch long dog-bone shaped section with 1 inch by 1 inch end tabs and a 0.5 inch by 0.5 inch center gauge section. These were stretched on an Instron testing machine with pneumatic grips at a rate of 12 inches / minute.The tensile stress at break and strain at break of the adhesive were then recorded; g) the melt viscosity of the hot melt adhesive was determined on a Brookfield Model RVT Thermosel viscometer using a No. 27 spindle; h) the ring and ball softening point temperature was measured by using a HRB754 support point apparatus.

[0431] Reversely graded thermoplastic elastomer hot melt adhesive

[0432] Several hot melt adhesive formulations containing the inversely tapered thermoplastic elastomer compositions CTTE D-149C HMA and CTTE D-143C HMA of the present invention were prepared according to the following procedure. The inversely tapered thermoplastic elastomer compositions CTTE D-149C and CTTE-D143C described in Example 18 were mixed with the materials and amounts described in the following formulations. Each inversely tapered thermoplastic elastomer composition CTTE was mixed with the remaining components / additives of the hot melt adhesive formulation by first placing a compatible tackifying resin such as Foral 85, an oil such as Nyflex 222, and an antioxidant such as Irganox 1330 in a jacketed mixing kettle equipped with a 3-blade propeller shear mixer Eurostar Power Control-Vic IKA and raising the temperature to a range of about 165°C to about 177°C for about 30 minutes or until the mixture is molten. After the mixture is melted, the temperature is reduced to about 150°C to 165°C, the mixture is first stirred at about 250 rpm, and then the reverse tapered thermoplastic elastomer composition CTTE is slowly added to the mixture for about 5 minutes to 10 minutes, during which the stirring speed is increased to about 400 rpm, and finally up to about 750 rpm, while promoting the incorporation of the polymer into the increasingly viscous mixture and avoiding the agglomeration of unmelted polymer particles. Then, continue mixing at about 750 rpm and heating at about 170°C for about 120 minutes or until a smooth and uniform material is observed, thereby obtaining the novel hot melt adhesive composition of the present invention, which comprises the reverse tapered thermoplastic elastomer composition CTTE and the remaining components / additives of the hot melt adhesive formulation. After the mixing is completed, the novel hot melt adhesive composition is immediately applied to a substrate such as Mylar at a temperature range of about 160°C to about 170°C to obtain an adhesive coating within the test protocol specification (i.e., a coating weight of 18-22 g / m 2 ).

[0433] The hot melt adhesive formulations of the inversely tapered thermoplastic elastomer compositions CTTE D-149C HMA and CTTE D-143C HMA consisted of the following amounts, in parts per hundred parts of rubber (phr): 178.00 phr of Foral 85 tackifying resin; 50.00 phr of Nyflex 223 oil; and 4.00 phr of Irganox 1330 antioxidant, based on the total amount of the inversely tapered thermoplastic elastomer composition (i.e., CTTE D-149C or CTTE D-143C) in the hot melt adhesive formulation (i.e., 100.00 phr).

[0434] The CTTE D-149C HMA-UV formulation for UV curable hot melt pressure sensitive adhesive consisted of the following amounts, in parts per hundred parts of rubber (phr): 178.00 phr tackifying resin (50:50 wt:wt, Piccolyte A-125:Estergum F-85); 50.00 phr Nyflex 223 oil; 4.00 phr Irganox 1010 antioxidant; and 9.0 phr photoinitiator (50:50 wt:wt, Omnirad MBF:Omnirad 819), based on the total amount of the inverse tapered thermoplastic elastomer composition CTTE D-149C (i.e., 100.00 phr). UV curing was performed using a high intensity Mini-conveyor UV curing unit with a mercury lamp having a wavelength of 365 nm and 300 WPI at 10 FPM.

[0435] The properties of the novel hot melt adhesive compositions CTTE D-149C HMA and CTTE D-143C HMA comprising the inversely tapered thermoplastic elastomer composition of the present invention were characterized according to the test procedure described in Example 19, as shown in Table 22. The Brookfield melt viscosity of the hot melt adhesives was measured at 130, 150 and 180°C. CTTE D-149C HMA showed Brookfield melt viscosities of 19260 cP at 130°C, 6694 cP at 150°C, and 2261 cP at 180°C. The novel hot melt adhesives CTTE D-149C HMA and CTTE D-143C HMA showed improved processability during application on substrates used in the test procedure. The reduced Brookfield melt viscosity is not only an important processability performance advantage of the new hot melt adhesives over the prior art, considering that higher productivity and cost efficiency are allowed under the same processing conditions, but also a low-energy processability performance advantage considering that lower processing temperatures are allowed for the same productivity and cost efficiency, which is a more environmentally friendly approach.

[0436] Table 22 shows the performance of the new hot melt adhesive compositions CTTE D-149C HMA and CTTE D-143C HMA. CTTE D-149C HMA shows a ring and ball softening point temperature (TRBSP) of about 93°C. CTTE D-143C HMA shows a ring and ball softening point temperature (TRBSP) of about 82°C. The 180° peel test of the hot melt adhesive composition for determining the peeling energy or peeling force (lbf) per unit width according to the PSTC-101 method shows that the peeling force of CTTE D-149C HMA is about 5.6lbf, and the peeling force of CTTE D-143C HMA is about 2.5lbf. The hot melt adhesive composition ring initial adhesion test for determining the maximum force (lbf) per unit width according to the PSTC-16 method shows that the ring initial adhesion for CTTE D-149C HMA is about 4.6lbf / in2, and the ring initial adhesion for CTTE D-143C HMA is about 4.4lbf / in2. Hot Melt Adhesive Composition Holding Strength Measurement The time to failure of the adhesive (min) was determined according to the PSTC-107 method and correlated with room temperature cohesive or shear properties, which showed a holding strength time of about 1660 minutes for CTTE D-149C HMA and about 1443 minutes for CTTE D-143C HMA. The improvements in processability and reinforcement properties of the CTTE D-149C HMA and CTTE D-143C HMA compositions are attributed to the properties of the inversely tapered thermoplastic elastomer (A-[A / B])2-X or (A-[A / B])nX partially coupled compositions (i.e., low [A / B] block and [A / B]nX midblock blockiness and high vinyl [A / B] block and [A / B]nX midblock), respectively.

[0437] The properties of the novel hot melt adhesive composition CTTE D-149C HMA-UV containing the inversely tapered thermoplastic elastomer composition of the present invention were characterized before and after curing according to the test procedure described in Example 19 as shown in Table 22. The Brookfield melt viscosity of the hot melt adhesive was measured before curing at 150°C and 180°C. CTTE D-149C HMA-UV exhibited Brookfield melt viscosities of 10285 cP at 150°C and 2766 cP at 180°C. CTTE D-149C HMA-UV exhibited a Ring and Ball Softening Point Temperature (TRBSP) of about 110.0°C before curing. The hot melt adhesive composition tensile properties were measured using the Universal Equipment Test Method for tensile stress at break (kgf) and strain at break (%) and correlated to room temperature cohesive or shear properties, and for CTTE D-149C HMA-UV exhibited a tensile stress at break of about 3.8 kgf and a strain at break of about 966% before curing. For CTTE D-149C HMA-UV, the hot melt adhesive composition 180° peel test showed a peel force of about 2.8 lbf before cure and a peel force of about 2.0 lbf after cure. For CTTE D-149C HMA-UV, the hot melt adhesive composition loop tack test showed a loop tack of about 2.0 lbf / in2 before cure and a loop tack of about 0.01 lbf / in2 after cure. For CTTE D-149C HMA-UV, the hot melt adhesive composition holding force measurement showed a holding force time of about 27,000 minutes before cure and a holding force time of about 36,400 minutes after cure. For CTTE D-149C HMA-UV, the hot melt adhesive composition rolling ball tack showed a rolling ball distance of about 1.6 inches before cure and a rolling ball distance of greater than 15 inches after cure. In addition, the dynamic mechanical analysis (DMA) of CTTE D-149C HMA-UV was performed according to the test procedures and methods described in Example 19, as shown in Table 22. The first tan δ maximum (tan δmax) temperature, which is a measure of the Tg of the rubber matrix, increased from a Tg of about 15.0°C before curing to a Tg of about 26.8°C after curing. The third crossover temperature (tan δ=1) is the temperature at which the adhesive begins to flow and loses its cohesive strength, which can be related to the ring and ball softening point temperature (RBSPT) and / or the shear adhesion failure temperature (SAFT). The third crossover temperature of the new hot melt adhesive composition increased from about 113.6°C before curing to about 120.1°C after curing.

[0438] Table 22 Properties of hot melt pressure sensitive adhesive compositions

[0439]

[0440]

[0441] The hot melt adhesive compositions CTTE D-149C HMA and CTTE D-143C HMA exhibit: Brookfield viscosity at 130°C of 19260 to 32250 cP; Brookfield viscosity at 150°C of 6694 to 23844 cP; Brookfield viscosity at 180°C of 2261 to 15000 cP; Ring and Ball softening point of 82 to 93°C; Peel 180° of 2.5 to 5.6 lb f ; Ring initial tack is 4.4 to 4.6 lb f / in 2 ; and holding power of 1443 to 1660 minutes.

[0442] The hot melt adhesive composition CTTE D-143C HMA exhibits: a melt viscosity at 130°C of less than 45,000 cP, preferably a melt viscosity at 130°C of less than 40,000 cP, and most preferably a melt viscosity at 130°C of less than 35,000 cP; a melt viscosity at 150°C of less than 35,000 cP, preferably a melt viscosity at 150°C of less than 30,000 cP, and most preferably a melt viscosity at 150°C of less than 25,000 cP; a melt viscosity at 180°C of less than 25,000 cP, preferably a melt viscosity at 180°C of less than 20,000 cP, and most preferably a melt viscosity at 180°C of less than 15000 cP. 0cP; Ring and Ball softening point greater than 70°C, preferably the Ring and Ball softening point greater than 75°C, and most preferably the Ring and Ball softening point greater than 80°C; Peel 180° greater than 1.5lbf, preferably Peel 180° greater than 2.0lbf, and most preferably Peel 180° greater than 2.5lbf; Loop tack greater than 3.0lbf / in2, preferably the loop tack greater than 3.5lbf / in2, and most preferably the loop tack greater than 4.0lbf / in2; and holding force greater than 500 minutes, preferably the holding force greater than 1000 minutes, and most preferably the holding force greater than 1400 minutes.

[0443] The hot melt adhesive composition CTTE D-149C HMA exhibits: a melt viscosity at 130°C of less than 30,000 cP, preferably a melt viscosity at 130°C of less than 25,000 cP, and most preferably a melt viscosity at 130°C of less than 20,000 cP; a melt viscosity at 150°C of less than 15,000 cP, preferably a melt viscosity at 150°C of less than 10,000 cP, and most preferably a melt viscosity at 150°C of less than 7,000 cP; a melt viscosity at 180°C of less than 10,000 cP, preferably a melt viscosity at 180°C of less than 5,000 cP, and most preferably a melt viscosity at 180°C of less than 2,500 cP. cP; Ring and Ball softening point greater than 80°C, preferably Ring and Ball softening point greater than 85°C, most preferably Ring and Ball softening point greater than 90°C; Peel 180° greater than 3.0 lbf, preferably Peel 180° greater than 4.0 lbf, most preferably Peel 180° greater than 5.5 lbf; Loop tack greater than 3.0 lbf / in2, preferably Loop tack greater than 4.0 lbf / in2, most preferably Loop tack greater than 4.5 lbf / in2; and Holding tack greater than 500 minutes, preferably Holding tack greater than 1000 minutes, most preferably Holding tack greater than 1600 minutes.

[0444] The properties of the novel hot melt adhesive composition CTTE D-149C HMA-UV containing the inversely tapered thermoplastic elastomer composition of the present invention after curing show increased cohesive strength (ie, holding force) and increased thermal resistance (ie, SAFT), while the adhesive properties are reduced.

[0445] Embodiment 20

[0446] Adhesives in tapes and labels

[0447] Reversely graded thermoplastic elastomer hot melt adhesive

[0448] Low Mw inversely tapered thermoplastic elastomer A-[A / B] or S-[S / B] diblock compositions CTTE D-170C and CTTE D-170D with different vinyl [A / B] block (wt %) contents were prepared with high and medium vinyl, respectively, as described in Example 14 and used to prepare hot melt adhesive formulations by following the procedure described in Example 19. The inversely tapered thermoplastic elastomer compositions were mixed with the materials and amounts described in the following formulations to obtain the inventive hot melt adhesive compositions CTTE D-170C HMA and CTTE D-170D HMA in Table 23.

[0449] The hot melt adhesive formulations CTTE D-170C HMA and CTTE D-170D HMA were composed of the following amounts, in parts per hundred parts of rubber (phr): 171.00 phr tackifying resin (107.00 phr Escorez 1310LC and 64.00 phr Estergum F-85); 50.00 phr Nyflex 223 oil; and 2.00 phr Irganox 1330 antioxidant, based on the total amount of polymers 100.00 phr (49.00 phr CTTE D-170C or CTTE D-170D, and 51.00 phr SIS) in the hot melt adhesive formulation.

[0450] As shown in Table 23, the properties of the novel hot melt adhesive compositions CTTE D-170C HMA and CTTE D-170D HMA containing the inversely tapered thermoplastic elastomer composition of the present invention were characterized according to the test procedure described in Example 19. The Brookfield melt viscosity of the hot melt adhesive was measured at 150, 160 and 177°C. The CTTE D-170C HMA exhibited a Brookfield melt viscosity of 15467 cP at 150°C, 9540 cP at 160°C, and 5300 cP at 177°C. The CTTE D-170D HMA exhibited a Brookfield melt viscosity of 18292 cP at 150°C, 11413 cP at 160°C, and 6600 cP at 177°C. Solprene 1205 HMA exhibits Brookfield melt viscosities of 14600 cP at 150°C, 9730 cP at 160°C, and 5700 cP at 177°C. The new hot melt adhesive CTTE D-170C HMA exhibits improved processability during application on substrates used in the test procedure. The reduced Brookfield melt viscosity is not only an important processability performance advantage of the new hot melt adhesive over the prior art (i.e. Solprene 1205 HMA), considering that higher productivity and cost efficiency are allowed under the same processing conditions, but also considering that lower processing temperatures are allowed for the same productivity and cost efficiency, which is a more environmentally friendly approach, the reduced Brookfield melt viscosity is also a low energy processability performance advantage.

[0451] Table 23 shows the performance of the new hot melt adhesive compositions CTTE D-170C HMA and CTTE D-170D HMA compared to the prior art hot melt adhesive composition Solprene 1205HMA. The hot melt adhesive compositions exhibited a Ring and Ball Softening Point Temperature (TRBSP) of about 98.4°C for CTTE D-170C HMA, a Ring and Ball Softening Point Temperature (TRBSP) of about 96.2°C for CTTE D-170DHMA, and a Ring and Ball Softening Point Temperature (TRBSP) of about 96.6°C for Solprene 1205HMA. 180° peel testing of the hot melt adhesive compositions, which measures peel energy or peel force per unit width (lbf) according to the PSTC-101 method, showed a peel force of about 7.4 lbf for CTTE D-170C HMA, about 6.0 lbf for CTTE D-170D HMA, and about 2.9 lbf for Solprene 1205HMA. The loop tack test of the hot melt adhesive compositions, which measures the maximum force per unit width (lbf) according to the PSTC-16 method, shows that the loop tack of CTTE D-170C HMA is about 5.2 lbf / in2, the loop tack of CTTE D-170D HMA is about 4.4 lbf / in2, and the loop tack of Solprene 1205HMA is about 3.8 lbf / in2. The hot melt adhesive composition holding force measurement is the time to adhesive failure (min) according to the PSTC-107 method and is related to the room temperature cohesive or shear performance, showing that the holding force time of CTTE D-170C HMA is about 157 minutes, the holding force time of CTTE D-170DHMA is about 105 minutes, and the holding force time of Solprene 1205HMA is about 25 minutes. The hot melt adhesive composition tensile properties measured tensile stress at break (kgf) and strain at break (%) and correlated with room temperature cohesive or shear properties, showing a tensile stress at break of about 2.2 kgf and strain at break of about 2000% for CTTE D-170C HMA, a tensile stress at break of about 1.5 kgf and strain at break of about 2000% for CTTE D-170D HMA, and a tensile stress at break of about 0.5 kgf and strain at break of about 2000% for Solprene 1205 HMA. The hot melt adhesive composition rolling ball tack test determined quick tack by measuring the distance traveled by a ball along the tape according to the PSTC-6 method, showing a rolling ball tack distance of about 1.05 inches for CTTE D-170C HMA, about 1.25 inches for CTTE D-170D HMA, and about 0.5 inches for Solprene 1205 HMA.The improved processability and reinforcement properties of CTTE D-170C HMA and CTTE D-170D HMA compared to prior art compositions are attributed to the characteristics of the inverse tapered thermoplastic elastomer A-[A / B] or S-[S / B] diblock compositions (i.e., low [A / B] block blockiness and high / medium vinyl [A / B] blocks).

[0452] The properties of the novel hot melt adhesive compositions CTTE D-170C HMA and CTTE D-170D HMA comprising the inventive inversely tapered thermoplastic elastomer diblock composition were characterized by dynamic mechanical analysis (DMA) performed according to the test procedure and method described in Example 19, as shown in Table 23. The hot melt adhesive storage modulus G' at room temperature (25°C), which quantifies the compliance of the adhesive at the application temperature according to the Dahlquist standard for measurable quick tack of 300,000 Pa and the Dahlquist standard for measurable holding force of 50,000 Pa, showed a storage modulus G' of about 61,700 Pa at 25°C for CTTE D-170C HMA, a storage modulus G' of about 65,500 Pa at 25°C for CTTE D-170D HMA, and a storage modulus G' of about 34,600 Pa at 25°C for Solprene 1205 HMA. The hot melt adhesive tan δ maximum (tan δ maximum) peak height, which indicates how much energy the adhesive can dissipate, shows that the tan δ maximum peak height of CTTE D-170C HMA is about 2.52, the tan δ maximum peak height of CTTE D-170D HMA is about 1.92, and the tan δ maximum peak height of Solprene 1205HMA is about 1.65. The first tan δ maximum (tan δ max) temperature is a measure of the Tg of the rubber matrix, which shows that the tan δ maximum temperature Tg of CTTE D-170C HMA is about 1.5°C, the tan δ maximum temperature Tg of CTTE D-170D HMA is about 4.4°C, and the tan δ maximum temperature Tg of Solprene 1205HMA is about 4.4°C. The third crossover temperature (tan δ=1), which is the temperature at which the adhesive begins to flow and lose its cohesive strength, shows a crossover temperature of about 100.5°C for CTTE D-170C HMA, about 94.7°C for CTTE D-170D HMA, and about 94.7°C for Solprene 1205 HMA.

[0453] Table 23 Properties of hot melt pressure sensitive adhesive compositions

[0454]

[0455] The hot melt adhesive compositions CTTE D-170C HMA and CTTE D-170D HMA exhibited: Brookfield viscosity at 150°C of 15467 to 18292 cP; Brookfield viscosity at 160°C of 9540 to 11413 cP; Brookfield viscosity at 177°C of 5300 to 6600 cP; Ring and Ball softening point of 96.2 to 98.4°C; Peel 180° of 6.0 to 7.4 lb f ; Ring initial tack is 4.4 to 5.2 lb f / in 2 ; Holding force is 105 to 157 minutes; Tensile stress at break is 1.5 to 2.2 kgf; Strain at break is about 2000%; Rolling ball initial tack is 1.05 to 1.25 in; Storage modulus G′ at 25°C is 61700 to 65500 Pa; Tanδ maximum peak height is 1.92 to 2.52; Tanδ maximum temperature (Tg) is 1.5 to 4.4°C; and Crossover temperature is 94.7 to 100.5°C.

[0456] The hot melt adhesive compositions CTTE D-170C HMA and CTTE D-170D HMA exhibit: a melt viscosity at 150°C of less than 25,000 cP, preferably a melt viscosity at 150°C of less than 18,500 cP, and most preferably a melt viscosity at 150°C of less than 15,500 cP; a melt viscosity at 160°C of less than 20,000 cP, preferably a melt viscosity at 160°C of less than 11,500 cP, and most preferably a melt viscosity at 160°C of less than 9,600 cP; a melt viscosity at 177°C of less than 15,000 cP, preferably a melt viscosity at 177°C of less than 7,000 cP, and most preferably a melt viscosity at 177°C of less than 15,000 cP. ℃ melt viscosity is less than 5500cP; Ring and Ball softening point is greater than 85℃, preferably the Ring and Ball softening point is greater than 95℃, and the most preferred Ring and Ball softening point is greater than 98℃; peel 180° is greater than 3.0lbf, preferably the peel 180° is greater than 5.0lbf, and the most preferred peel 180° is greater than 7.0lbf; loop initial tack is greater than 3.0lbf / in2, preferably the loop initial tack is greater than 4.0lbf / in2, and the most preferred loop initial tack is greater than 5.0lbf / in2; holding force is greater than 25 minutes, preferably the holding force is greater than 1 00 minutes, the most preferred holding force is greater than 150 minutes; the tensile stress at break is greater than 0.5kgf, the preferred tensile stress at break is greater than 1.0kgf, and the most preferred tensile stress at break is greater than 2.0kgf; the strain at break is greater than 500%, the preferred strain at break is greater than 1000%, and the most preferred strain at break is greater than 1500%; the initial rolling ball tack is less than 3.0 inches, the preferred initial rolling ball tack is less than 2.0 inches, and the most preferred initial rolling ball tack is less than 1.5 inches; the storage modulus G' at 25°C is greater than 35000Pa, the preferred 25°C The storage modulus G′ at 25°C is greater than 50,000 Pa, and the most preferred storage modulus G′ at 25°C is greater than 60,000 Pa; the maximum peak height of tanδ is greater than 1.65, the preferred maximum peak height of tanδ is greater than 2.0, and the most preferred maximum peak height of tanδ is greater than 2.5; the maximum temperature of tanδ (Tg) is lower than 5°C, the preferred maximum temperature of tanδ (Tg) is lower than 4°C, and the most preferred maximum temperature of tanδ (Tg) is lower than 3°C; the crossover temperature is greater than 90°C, the preferred crossover temperature is greater than 95°C, and the most preferred crossover temperature is greater than 100°C.

[0457] Having described the present invention above, various modifications to techniques, procedures, materials and equipment will be apparent to those skilled in the art. It is intended that all such changes within the scope and spirit of the present invention be included within the scope of the appended claims.

Claims

1. An asphalt and / or petroleum asphalt composition comprising: (a) bitumen and / or petroleum bitumen; and (b) a first inversely tapered thermoplastic elastomer (first CTTE) composition, wherein the asphalt and / or petroleum asphalt composition comprises 0.5 to 25 weight percent of the first CTTE composition, and wherein the first CTTE composition comprises: Units of at least one monovinyl aromatic monomer, A, are polymerized with units of at least one conjugated diene monomer, B, to form an inversely tapered diblock A-[A / B] copolymer, wherein the A block comprises a polymer of said monovinyl aromatic monomer units, wherein the [A / B] block is a copolymer of said monovinyl aromatic monomer units and conjugated diene monomer units, and wherein said [A / B] block is inversely tapered such that the ratio of B to A is lower at locations proximal to the A block relative to the ratio of B to A at locations distal to the A block.

2. The asphalt and / or petroleum asphalt composition according to claim 1, wherein the total amount of units of the conjugated diene monomer B is greater than 55 wt% of the first CTTE composition.

3. The asphalt and / or petroleum asphalt composition according to claim 2, wherein the conjugated diene monomer B is at least one monomer selected from 1,3-butadiene, isoprene, myrcene and / or farnesene.

4. The bitumen and / or petroleum asphalt composition according to claim 3, wherein the conjugated diene units are selectively, partially or fully hydrogenated.

5. The asphalt and / or petroleum asphalt composition of claim 1, wherein in the inverse tapered diblock A-[A / B] copolymer, the vinyl content is higher near the A block relative to the vinyl content away from the A block.

6. The asphalt and / or petroleum asphalt composition of claim 1, wherein the total amount of units of the conjugated diene monomer B is greater than 55 wt% of the first CTTE composition, and wherein in the inverse tapered diblock A-[A / B] copolymer, the vinyl content is higher near the A block relative to the vinyl content away from the A block.

7. The asphalt and / or petroleum asphalt composition of claim 1, wherein the [A / B] block of the first CTTE composition comprises 2-40 wt% of the monovinyl aromatic monomer A and 60-98 wt% of the conjugated diene monomer B.

8. The asphalt and / or petroleum asphalt composition of claim 1, wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of 500-6000 cP at 135°C as measured according to ASTM D4402, wherein the asphalt and / or petroleum asphalt composition has a softening point greater than 50°C, and wherein the asphalt and / or petroleum asphalt composition has an elastic recovery greater than 45% at 25°C as measured by a ductometer.

9. The asphalt and / or petroleum asphalt composition as claimed in claim 8, wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of 500-3000 cP at 135°C as measured according to ASTM D 4402, wherein the asphalt and / or petroleum asphalt composition has an elastic recovery of greater than 20% at 10°C as measured by a ductility meter, wherein the asphalt and / or petroleum asphalt composition has a ductility of greater than 50 cm at 25°C, and wherein the asphalt and / or petroleum asphalt composition has a phase separation below 5.0°C.

10. The asphalt and / or petroleum asphalt composition of claim 1, wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of less than 4000 cP at 135°C as measured according to ASTM D4402, wherein the asphalt and / or petroleum asphalt composition has a softening point greater than 55°C, and wherein the asphalt and / or petroleum asphalt composition has an elastic recovery greater than 50% at 25°C as measured by an extensometer.

11. The asphalt and / or petroleum asphalt composition of claim 1 further comprising an emulsifier, wherein the asphalt and / or petroleum asphalt composition is emulsified in water, thereby forming a PMA residue.

12. The asphalt and / or petroleum asphalt composition of claim 11, wherein the PMA residue has a dynamic viscosity of less than 2000 cP at 135°C as measured according to ASTM D4402, and wherein the PMA residue has an elastic recovery of greater than 20% at 10°C as measured by a ductometer.

13. The asphalt and / or petroleum asphalt composition of claim 1, wherein the asphalt and / or petroleum asphalt composition comprises 4-8 wt. % of a first CTTE composition, and wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of less than 6000 cP at 135°C as measured according to ASTM D4402, has a softening point greater than 60°C and has an elastic recovery greater than 35% at 25°C as measured by torsion.

14. The asphalt and / or petroleum asphalt composition of claim 13, wherein the asphalt and / or petroleum asphalt composition comprises 2-4 wt. % of the first CTTE composition, and wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of less than 4000 cP at 135°C as measured according to ASTM D4402, has a softening point greater than 50°C, has an elastic recovery greater than 20% at 25°C as measured by torsion and has an elastic recovery greater than 45% at 25°C as measured by extensometer.

15. An asphalt and / or petroleum asphalt composition comprising: (a) bitumen and / or petroleum bitumen; and (b) a reverse tapered thermoplastic elastomer (CTTE) composition, wherein the asphalt and / or petroleum asphalt composition comprises 0.5 to 25 weight percent of the CTTE composition, and wherein the CTTE composition comprises: units of at least one monovinyl aromatic monomer A and at least one conjugated diene monomer B, and having a linear structure (A-[A / B])-X-([B / A]-A) and / or a coupled radial and / or multi-arm structure (A-[A / B])nX, wherein X is the residue of a coupling agent or a multifunctional initiator, wherein n is an integer from 2 to 30, wherein the CTTE composition has an outer block and / or a terminal block A, the block A being a polymer of the monovinyl aromatic monomer unit A, The CTTE composition has a midblock which is a copolymer of the monovinyl aromatic monomer unit A and the conjugated diene monomer unit B, wherein the midblock has a central region between terminal regions, and wherein the B / A ratio is higher in the central region than in the terminal regions.

16. The asphalt and / or petroleum asphalt composition of claim 15, wherein the vinyl content of the terminal regions is higher relative to the vinyl content of the central region in the CTTE composition.

17. The asphalt and / or petroleum asphalt composition of claim 15, wherein the asphalt and / or petroleum asphalt composition comprises 0.5-25 wt% of the CTTE composition.

18. The asphalt and / or petroleum asphalt composition of claim 15, wherein the asphalt and / or petroleum asphalt composition comprises 2-8 wt% of the CTTE composition.

19. The asphalt and / or petroleum asphalt composition of claim 1, further comprising a second inversely tapered thermoplastic elastomer (second CTTE) composition, wherein the second CTTE composition comprises: units of at least one monovinyl aromatic monomer A and at least one conjugated diene monomer B, and having a linear structure (A-[A / B])-X-([B / A]-A) and / or a coupled radial and / or multi-arm structure (A-[A / B])nX, wherein X is the residue of a coupling agent or a multifunctional initiator, wherein n is an integer from 2 to 30, wherein the second CTTE composition has an outer block and / or a terminal block A, the block A being a polymer of the monovinyl aromatic monomer unit A, wherein the second CTTE composition has a middle block which is a copolymer of the monovinyl aromatic monomer unit A and the conjugated diene monomer unit B, wherein the middle block has a central region between terminal regions, and wherein a B / A ratio is higher in the central region than in the terminal regions.

20. The asphalt and / or petroleum asphalt composition of claim 19, wherein the structure (A-[A / B])-X-([B / A]-A) or (A-[A / B])nX of the second CTTE composition comprises a [A / B]-X-[B / A] or [A / B]nX midblock, and wherein the [A / B]-X-[B / A] or [A / B]nX midblock comprises 2-40 wt% of the monovinyl aromatic monomer A and 60-98 wt% of the conjugated diene monomer B.

21. The asphalt and / or petroleum asphalt composition according to claim 20, wherein the conjugated diene monomer B is at least one monomer selected from 1,3-butadiene, isoprene, myrcene and / or farnesene.

22. The bitumen and / or petroleum asphalt composition of claim 21, wherein the conjugated diene units are selectively, partially or fully hydrogenated.

23. The asphalt and / or petroleum asphalt composition of claim 19, wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of 500-3000 cP at 135°C as measured according to ASTM D4402, and wherein the asphalt and / or petroleum asphalt composition has an elastic recovery of greater than 75% at 25°C as measured by an extensometer.

24. The asphalt and / or petroleum asphalt composition of claim 19, wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of less than 1000 cP at 135°C as measured according to ASTM D4402, and wherein the asphalt and / or petroleum asphalt composition has an elastic recovery of greater than 75% at 25°C as measured by a ductometer.

25. The asphalt and / or petroleum asphalt composition of claim 19, further comprising an emulsifier, wherein the asphalt and / or petroleum asphalt composition is emulsified in water, thereby forming a PMA residue.

26. The asphalt and / or petroleum asphalt composition of claim 25, wherein the PMA residue has a dynamic viscosity of less than 600 cP at 135°C as measured according to ASTM D4402, and wherein the PMA residue has an elastic recovery of greater than 75% at 10°C as measured by an extensometer.

27. The asphalt and / or petroleum asphalt composition of claim 19, wherein the asphalt and / or petroleum asphalt composition comprises 4-8 wt. % of the first and second CTTE compositions, and wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of less than 3000 cP at 135°C as measured according to ASTM D4402 and an elastic recovery of greater than 90% at 25°C as measured by an extensometer.

28. The asphalt and / or petroleum asphalt composition of claim 27, wherein the asphalt and / or petroleum asphalt composition comprises 2-4 wt. % of the first and second CTTE compositions, and wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of less than 1000 cP at 135°C as measured according to ASTM D4402, an elastic recovery greater than 75% at 25°C as measured by a ductometer, and a phase separation of less than 0.2°C or 0.3%.

29. An asphalt and / or petroleum asphalt composition comprising: (a) bitumen and / or petroleum bitumen; and (b) a reverse tapered thermoplastic elastomer (CTTE) composition, wherein the asphalt and / or petroleum asphalt composition comprises 0.5 to 25 weight percent of the CTTE composition, and wherein the CTTE composition comprises: (1) a reverse tapered diblock A-[A / B] copolymer comprising units of at least one conjugated diene monomer B and units of at least one monovinyl aromatic monomer A, wherein the diblock copolymer has a peak molecular weight of 20,000 to 250,000, wherein the monovinyl aromatic homopolymer block A has a peak molecular weight of at least 5,000, wherein the [A / B] blocks are inversely tapered, wherein [A / B] has a vinyl content of at least 15 wt. %, based on the amount of conjugated diene units in the diblock copolymer, and wherein reverse tapering means that the ratio of B to A in the [A / B] block is lower near the A block relative to the ratio of B to A far from the A block; and (2) a block copolymer comprising at least two inversely tapered diblock A-[A / B] copolymers, wherein the block copolymer has at least two monovinyl aromatic homopolymer blocks A and at least one copolymer block of monovinyl aromatic monomer units and conjugated diene monomer units, and The copolymer block is selected from the following group: a linear triblock copolymer having a peak molecular weight at least 1.5 times the peak molecular weight of the inverse tapered diblock copolymer, a multi-arm coupled block copolymer having a peak molecular weight at least 2.5 times the peak molecular weight of the inverse tapered diblock copolymer, and mixtures thereof.

30. The asphalt and / or petroleum asphalt composition of claim 29, wherein the ratio of (1) to (2) in the CTTE composition is 1:5 to 5:

1.

31. The asphalt and / or petroleum asphalt composition of claim 29, wherein the vinyl content of the diblock copolymer is higher near the A block relative to the vinyl content further away from the A block.

32. The asphalt and / or petroleum asphalt composition of claim 29, wherein the amount of conjugated diene monomer B in the diblock copolymer is greater than 55 wt%.

33. The asphalt and / or petroleum asphalt composition according to claim 32, wherein the conjugated diene monomer B is at least one monomer selected from 1,3-butadiene, isoprene, myrcene and / or farnesene.

34. The bitumen and / or asphalt composition of claim 33, wherein the conjugated diene units are selectively, partially or fully hydrogenated.

35. The asphalt and / or petroleum asphalt composition of claim 32, wherein the amount of monovinyl aromatic monomer units A in the CTTE composition is 10-48 wt%.

36. The asphalt and / or petroleum asphalt composition of claim 35, wherein the vinyl content in the CTTE composition is 15-90 wt% based on the total amount of conjugated diene units B in the CTTE composition.

37. The asphalt and / or petroleum asphalt composition of claim 29, wherein the [A / B] block of the inverse tapered diblock A-[A / B] copolymer comprises 2-40 wt% of the monovinyl aromatic monomer A and 60-98 wt% of the conjugated diene monomer B.

38. The asphalt and / or petroleum asphalt composition of claim 29, wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of 500-3000 cP at 135°C as measured according to ASTM D4402, and wherein the asphalt and / or petroleum asphalt composition has an elastic recovery greater than 75% at 25°C as measured by a ductility meter.

39. The asphalt and / or petroleum asphalt composition of claim 29, wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of less than 1000 cP at 135°C as measured according to ASTM D4402, and wherein the asphalt and / or petroleum asphalt composition has an elastic recovery of greater than 75% at 25°C as measured by a ductometer.

40. The asphalt and / or petroleum asphalt composition of claim 29, further comprising an emulsifier, wherein the asphalt and / or petroleum asphalt composition is emulsified in water, thereby forming a PMA residue.

41. The asphalt and / or petroleum asphalt composition of claim 40, wherein the PMA residue has a dynamic viscosity of less than 600 cP at 135°C as measured according to ASTM D4402, and wherein the PMA residue has an elastic recovery of greater than 75% at 10°C as measured by an extensometer.

42. The asphalt and / or asphalt composition of claim 29, wherein the asphalt and / or asphalt composition comprises 4-8 wt. % of the CTTE composition, and wherein the asphalt and / or asphalt composition has a dynamic viscosity of less than 3000 cP at 135°C as measured according to ASTM D4402 and an elastic recovery of greater than 90% at 25°C as measured by an extensometer.

43. The asphalt and / or petroleum asphalt composition of claim 42, wherein the asphalt and / or petroleum asphalt composition comprises 2-4 wt. % of the CTTE composition, and wherein the asphalt and / or petroleum asphalt composition has a dynamic viscosity of less than 1000 cP at 135°C as measured according to ASTM D4402, an elastic recovery of greater than 75% at 25°C as measured by a ductometer, and a phase separation of less than 0.2°C or 0.3%.

44. An adhesive composition comprising: (a) at least one additive selected from the group consisting of a tackifying resin, a plasticizer, a solvent, a coupling agent, a cross-linking agent, a photoinitiator and an antioxidant; and (b) a first inversely tapered thermoplastic elastomer (first CTTE) composition, wherein the adhesive composition comprises 0.5 to 50 weight percent of the first CTTE composition, and wherein the first CTTE composition comprises: Units of at least one monovinyl aromatic monomer, A, are polymerized with units of at least one conjugated diene monomer, B, to form a reverse tapered diblock A-[A / B] copolymer, wherein the A block comprises a polymer of monovinyl aromatic monomer units, wherein the [A / B] block is a copolymer of said monovinyl aromatic monomer units and conjugated diene monomer units, and wherein said [A / B] block is reverse tapered such that the ratio of B to A is lower near the A block relative to the ratio of B to A away from the A block.

45. The adhesive composition of claim 44, wherein the total amount of units of the conjugated diene monomer B is greater than 55 wt% of the first CTTE composition.

46. ​​The adhesive composition according to claim 45, wherein the conjugated diene monomer B is at least one monomer selected from 1,3-butadiene, isoprene, myrcene and / or farnesene.

47. The adhesive composition of claim 46, wherein the conjugated diene units are selectively, partially or fully hydrogenated.

48. The adhesive composition of claim 44, wherein in the inverse tapered diblock A-[A / B] copolymer, the vinyl content is higher proximal to the A block relative to the vinyl content distal to the A block.

49. The adhesive composition of claim 44, wherein the total amount of units of the conjugated diene monomer B is greater than 55 wt% of the first CTTE composition, and wherein the vinyl content near the A block is higher relative to the vinyl content away from the A block in the inverse tapered diblock A-[A / B] copolymer.

50. The adhesive composition of claim 44, wherein the [A / B] block of the first CTTE composition comprises 2-40 wt% of the monovinyl aromatic monomer A and 60-98 wt% of the conjugated diene monomer B.

51. The adhesive composition of claim 44, wherein the adhesive composition has a melt viscosity of less than 15,500 cP at 150°C, wherein the adhesive composition has a melt viscosity of less than 9,600 cP at 160°C, and wherein the adhesive composition has a melt viscosity of less than 5,500 cP at 177°C.

52. The adhesive composition of claim 51, wherein the adhesive composition has a Ring and Ball softening point temperature greater than 98°C, a Peel 180° greater than 7.0 lbf, a Loop Tack greater than 5.0 lbf / in2, a Holding Tack greater than 150 minutes, and a Rolling Ball Tack less than 1.5 in.

53. The adhesive composition of claim 44, wherein the adhesive composition has a melt viscosity of less than 18,500 cP at 150°C, wherein the adhesive composition has a melt viscosity of less than 11,500 cP at 160°C, and wherein the adhesive composition has a melt viscosity of less than 7,000 cP at 177°C.

54. The adhesive composition of claim 53, wherein the adhesive composition has a Ring and Ball softening point temperature greater than 95°C, a Peel 180° greater than 5.0 lbf, a Loop Tack greater than 4.0 lbf / in2, a Holding Tack greater than 100 minutes, and a Rolling Ball Tack less than 2.0 in.

55. An adhesive composition comprising: (a) at least one additive selected from the group consisting of a tackifying resin, a plasticizer, a solvent, a coupling agent, a cross-linking agent, a photoinitiator and an antioxidant; and (b) a reverse tapered thermoplastic elastomer (CTTE) composition, wherein the CTTE composition comprises: units of at least one monovinyl aromatic monomer A and at least one conjugated diene monomer B, and having a linear structure (A-[A / B])-X-([B / A]-A) and / or a coupled radial and / or multi-arm structure (A-[A / B])nX, wherein X is the residue of a coupling agent or a multifunctional initiator, wherein n is an integer from 2 to 30, wherein the CTTE composition has an outer block and / or a terminal block A, the block A being a polymer of the monovinyl aromatic monomer unit A, The CTTE composition has a midblock which is a copolymer of the monovinyl aromatic monomer unit A and the conjugated diene monomer unit B, wherein the midblock has a central region between terminal regions, and wherein the B / A ratio is higher in the central region than in the terminal regions.

56. The adhesive composition of claim 55, wherein the vinyl content in the end regions is higher relative to the vinyl content in the core region in the CTTE composition.

57. The adhesive composition of claim 55, wherein the adhesive composition comprises 0.5 wt% to 50 wt% of the CTTE composition.

58. The adhesive composition of claim 55, wherein the adhesive composition comprises 20 wt% to 40 wt% of the CTTE composition.

59. The adhesive composition of claim 44, further comprising a second inversely tapered thermoplastic elastomer (second CTTE) composition, wherein the second CTTE composition comprises: units of at least one monovinyl aromatic monomer A and at least one conjugated diene monomer B, and having a linear structure (A-[A / B])-X-([B / A]-A) and / or a coupled radial and / or multi-arm structure (A-[A / B])nX, wherein X is the residue of a coupling agent or a multifunctional initiator, wherein n is an integer from 2 to 30, wherein the second CTTE composition has an outer block and / or a terminal block A, the block A being a polymer of the monovinyl aromatic monomer unit A, wherein the second CTTE composition has a middle block which is a copolymer of the monovinyl aromatic monomer unit A and the conjugated diene monomer unit B, wherein the middle block has a central region between terminal regions, and wherein a B / A ratio is higher in the central region than in the terminal regions.

60. The adhesive composition of claim 59, wherein the structure (A-[A / B])-X-([B / A]-A) or (A-[A / B])nX of the second CTTE composition comprises a [A / B]-X-[B / A] or [A / B]nX midblock, and wherein the [A / B]-X-[B / A] or [A / B]nX midblock comprises 2 to 40 wt% of the monovinyl aromatic monomer A and 60 to 98 wt% of the conjugated diene monomer B.

61. The adhesive composition according to claim 60, wherein the conjugated diene monomer B is at least one monomer selected from 1,3-butadiene, isoprene, myrcene and / or farnesene.

62. The adhesive composition of claim 61, wherein the conjugated diene units are selectively, partially or fully hydrogenated.

63. An adhesive composition comprising: (a) at least one additive selected from the group consisting of a tackifying resin, a plasticizer, a solvent, a coupling agent, a cross-linking agent, a photoinitiator and an antioxidant; and (b) a reverse tapered thermoplastic elastomer (CTTE) composition, wherein the adhesive composition comprises 0.5 to 50 weight percent of the CTTE composition, and wherein the CTTE composition comprises: (1) a reverse tapered diblock A-[A / B] copolymer comprising units of at least one conjugated diene monomer B and units of at least one monovinyl aromatic monomer A, wherein the diblock copolymer has a peak molecular weight of 20,000 to 250,000, wherein the monovinyl aromatic homopolymer block A has a peak molecular weight of at least 5,000, wherein the [A / B] blocks are inversely tapered, wherein [A / B] has a vinyl content of at least 15 wt. %, based on the amount of conjugated diene units in the diblock copolymer, and wherein reverse tapering means that the ratio of B to A in the [A / B] block is lower near the A block relative to the ratio of B to A far from the A block; and (2) a block copolymer comprising at least two inversely tapered diblock A-[A / B] copolymers, wherein the block copolymer has at least two monovinyl aromatic homopolymer blocks A and at least one copolymer block of monovinyl aromatic monomer units and conjugated diene monomer units, and The copolymer block is selected from the following group: a linear triblock copolymer having a peak molecular weight at least 1.5 times the peak molecular weight of the inverse tapered diblock copolymer, a multi-arm coupled block copolymer having a peak molecular weight at least 2.5 times the peak molecular weight of the inverse tapered diblock copolymer, and mixtures thereof.

64. The adhesive composition of claim 63, wherein the ratio of (1) to (2) in the CTTE composition is 1:5 to 5:

1.

65. The adhesive composition of claim 63, wherein the diblock copolymer has a higher vinyl content proximal to the A block relative to the vinyl content distal to the A block.

66. The adhesive composition of claim 63, wherein the amount of conjugated diene monomer B in the diblock copolymer is greater than 55 wt%.

67. The adhesive composition of claim 66, wherein the conjugated diene monomer B is at least one monomer selected from 1,3-butadiene, isoprene, myrcene and / or farnesene.

68. The adhesive composition of claim 67, wherein the conjugated diene units are selectively, partially or fully hydrogenated.

69. The adhesive composition of claim 66, wherein the amount of monovinyl aromatic monomer units A in the CTTE composition is from 10 wt% to 48 wt%.

70. The adhesive composition of claim 69, wherein the vinyl content in the CTTE composition is 15 wt% to 90 wt% based on the total amount of conjugated diene units B in the CTTE composition.

71. The adhesive composition of claim 63, wherein the [A / B] block of the inverse tapered diblock A-[A / B] copolymer comprises 2-40 wt% of the monovinyl aromatic monomer A and 60-98 wt% of the conjugated diene monomer B.

72. The adhesive composition of claim 63, wherein the adhesive composition comprises 20-40 wt% of the first and second CTTE compositions of claim 36 or the CTTE composition of claim 42.

73. The adhesive composition of claim 63, wherein the adhesive composition has a melt viscosity of less than 35,000 cP at 130°C, wherein the adhesive composition has a melt viscosity of less than 25,000 cP at 150°C, and wherein the adhesive composition has a melt viscosity of less than 15,000 cP at 180°C.

74. The adhesive composition of claim 73, wherein the adhesive composition has a Ring and Ball softening point temperature greater than 70°C, a Peel 180° greater than 1.5 lbf, a Loop Tack greater than 3.0 lbf / in2, and a Holding Tack greater than 500 minutes.

75. The adhesive composition of claim 63, wherein the adhesive composition has a melt viscosity of less than 20,000 cP at 130°C, wherein the adhesive composition has a melt viscosity of less than 7,000 cP at 150°C, and wherein the adhesive composition has a melt viscosity of less than 2,500 cP at 180°C.

76. The adhesive composition of claim 75, wherein the adhesive composition has a Ring and Ball softening temperature greater than 90°C.

77. The adhesive composition of claim 75, wherein the adhesive composition has a Ring and Ball softening point temperature greater than 80°C, a Peel 180° greater than 3.0 lbf, a Loop Tack greater than 3.0 lbf / in2, and a Holding Tack greater than 500 minutes.

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