A kind of low softening point rosin resin and preparation method thereof

Abstract

The present invention provides a rosin resin with a low softening point and a preparation method thereof. The epoxidized alpha olefin oligomer and rosin are subjected to a ring-opening reaction to obtain the low softening point rosin resin, thereby introducing a long-chain alkyl group into the rosin resin, reducing the softening point and melt viscosity of the rosin, and the ring-opening reaction has lower requirements for reaction temperature and reaction time. The modified rosin resin is used for a hot melt pressure-sensitive adhesive alone or in combination with other tackifying resins, which can reduce the melt viscosity and coating temperature of the hot melt pressure-sensitive adhesive, reduce energy consumption and construction costs, and also reduce damage and aging to flexible substrates. At the same time, the addition of the low softening point rosin resin also improves the viscoelasticity of the pressure-sensitive adhesive system, improves the wettability of the pressure-sensitive adhesive, and the addition of 5-10wt% of the low softening point rosin resin and other tackifying resins can further improve the peel strength and initial adhesion of the hot melt pressure-sensitive adhesive.

Description

Technical Field

[0001] The invention relates to the technical field of rosin resin modification, in particular to a rosin resin with a low softening point and a preparation method thereof. Background Art

[0002] Rosin is a natural renewable resin secreted by pine trees. It can be used as a substitute for some petroleum-based products such as petroleum resin. The main component of rosin is rosin resin acid, which is a general term for a mixture of isomers. The resin acids whose structures have been preliminarily determined include abietic acid, neoabietic acid, pimaric acid, isopimaric acid, dehydroabietic acid and palustric acid. These resin acids have the same molecular formula C 20 H 30 O2, as well as a tricyclic phenanthrene skeleton, two double bonds and a carboxylic acid. The special phenanthrene ring structure gives rosin good mechanical strength, heat resistance, corrosion resistance, moisture resistance, insulation and other properties. It is widely used in rubber, adhesives, coatings, inks, papermaking and other industries. However, the structural characteristics of rosin itself lead to its disadvantages of easy crystallization, poor alkali resistance, high chroma and high acid value. In particular, rosin with a high content of abietic acid resin acid is very easy to crystallize. Crystallization refers to the appearance of abietic acid resin acid crystals in transparent rosin blocks, which causes the appearance of rosin to become turbid, the melting point is high and difficult to dissolve, and abietic acid resin acid also has a tendency to crystallize in general organic solvents, thereby limiting the application range of rosin. The two active groups of double bonds and carboxyl groups in rosin can be further modified to obtain different types of rosin derivatives, thereby overcoming the defects caused by its molecular structure and expanding the application range of rosin.

[0003] At present, most of the research on carboxyl modification in rosin is achieved through esterification reaction. After esterification, the acid value of rosin can be reduced, the softening point can be changed, and its heat resistance or cold resistance can be improved. At the same time, polar bonds such as ester bonds are retained in the molecules, and the viscosity and cohesive strength of adhesives can be guaranteed. For example, Chinese patent CN102965024A discloses a preparation method of rosin tackifying resin, which uses rosin and polyols to react to prepare a rosin tackifying resin with a high softening point. The resin has good compatibility with EVA elastomers and can be used to prepare hot melt adhesives. Chinese patent CN102676062B discloses a low-temperature resistant rosin tackifying resin, which uses polyols and higher fatty acids to esterify rosin to obtain rosin with low softening point and viscosity and high cold resistance. It can be used for hot melt pressure-sensitive adhesives to avoid the problem of reduced viscosity and bonding failure at low temperatures.

[0004] However, the carboxyl groups in various rosin resin acids such as abietic acid and pimaric acid are all located on tertiary carbon atoms, and the steric hindrance is very high. The esterification reaction proposed in the prior art requires a very high reaction temperature (200-300°C) and a long reaction time (at least 6-10 hours). Moreover, after esterification, the softening point and glass transition temperature (Tg) are usually increased due to the increase in the molecular weight of the rosin resin itself. When used in adhesives such as hot melt adhesives, a temperature of at least 170°C is required to completely melt and apply. At the same time, the molecular weight of the modified rosin resin is significantly increased, and it is difficult to achieve a good interface wetting effect when used in pressure-sensitive adhesives, especially it is difficult to achieve a balance in bonding properties such as initial adhesion, holding force and peel strength.

[0005] The use of high temperature to apply hot melt adhesive increases the risk of operators inhaling residual volatiles and burns. In addition, high temperature requires more energy and increases the requirements for manufacturing equipment, thereby increasing the difficulty and cost of the coating process. To solve this problem, Chinese patent CN101044203B proposes to mix tackifying resins such as rosin and petroleum resin with poly-α-olefin oil, thereby achieving control and regulation of the softening point of the tackifying resin, but the mixing of poly-α-olefin oil and tackifying resin belongs to simple physical mixing, and the softening point of the tackifying resin is reduced by external plasticization, and there are compatibility problems with the base resin. After the hot melt adhesive is applied, it is easy to have insufficient transparency and turbidity and fogging of the colloid. At the same time, the external plasticizing component will also affect the initial adhesion, peel strength and adhesion to the substrate of the hot melt adhesive itself. Summary of the invention

[0006] The purpose of the present invention is to overcome the above disadvantages, graft rosin resin acid onto α-olefin oligomers, thereby obtaining rosin resin with a low softening point, which significantly reduces the melt viscosity of the hot melt pressure-sensitive adhesive and requires a lower coating temperature.

[0007] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0008] In a first aspect, the present invention provides a rosin resin with a low softening point, which is obtained by reacting an epoxidized α-olefin oligomer with rosin.

[0009] The softening point of the rosin resin is not higher than 65° C. as measured by ASTM E-28. Preferably, the softening point of the rosin resin is not higher than 60° C. as measured by ASTM E-28. More preferably, the softening point of the rosin resin is not higher than 56° C. as measured by ASTM E-28.

[0010] The degree of polymerization of the epoxidized alpha olefin oligomer is 2-4, preferably, the degree of polymerization of the epoxidized alpha olefin oligomer is 2; the structure of the epoxidized alpha olefin oligomer includes:

[0011] , or One or more of; wherein a, b, c and d are independent of each other, and the values ​​may be the same or different, and the value range of a, b, c and d is 1-17, and preferably, the value range of a, b, c and d is 1-11.

[0012] The rosin is a mixture of various rosin resin acids, a small amount of fatty acids and neutral substances. The acid value of the rosin is not less than 155 mgKOH / g, and its softening point is not less than 75°C as measured by ASTM E-28 method; preferably, the content of rosin resin acid in the rosin is not less than 90wt%.

[0013] Further, the rosin is selected from: one or more combinations of: Masson rosin, Elliot rosin, Simao rosin, Caribbean rosin and South Asia rosin. Preferably, the rosin is selected from Masson rosin.

[0014] Further, the rosin resin acid includes: abietic acid (CAS No.: 17817-95-7), neoabietic acid (CAS No.: 471-77-2), dehydroabietic acid (CAS No.: 1740-19-8), levopimaric acid (CAS No.: 79-54-9), palustric acid (CAS No.: 1945-53-5), pimaric acid (CAS No.: 127-27-5), isopimaric acid (CAS No.: 5835-26-7) and sandaracopimaric acid (CAS No.: 471-74-9) One or more combinations thereof; the chemical structure of the rosin resin acid comprises: a ternary phenanthrene ring skeleton structure, at least one double bond and at least one carboxyl group. The rosin resin acid can be divided into: abietic acid-type resin acid and pimaric acid-type resin acid according to the difference in chemical structure.

[0015] In a second aspect, the method for preparing the above-mentioned rosin resin comprises: subjecting an epoxidized α-olefin oligomer to a ring-opening reaction with rosin in the presence of a catalyst.

[0016] Preferably, the temperature of the ring-opening reaction is 100-160°C, and more preferably, the temperature of the ring-opening reaction is 120-150°C.

[0017] Preferably, the catalyst is an alkyl trimethyl ammonium halide, wherein the alkyl group includes at least one straight-chain alkyl group with a carbon number of ≥10, selected from: n-decyl trimethyl ammonium chloride, n-decyl trimethyl ammonium bromide, dodecyl trimethyl ammonium chloride, dodecyl trimethyl ammonium bromide, tetradecyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium chloride and octadecyl trimethyl ammonium bromide, any one or a combination thereof. Preferably, the catalyst is hexadecyl trimethyl ammonium bromide (CTAB).

[0018] Preferably, the epoxidized α-olefin oligomer is prepared by epoxidation of α-olefin oligomer.

[0019] Further, the alpha olefin oligomer structure comprises:

[0020] , or One or more of the above, wherein a, b, c and d are independent of each other, and the values ​​may be the same or different, and the value range of a, b, c and d is 1-17, and preferably, the value range of a, b, c and d is 1-11.

[0021] Furthermore, the alpha olefin oligomer is obtained by coordination polymerization of a metallocene catalyst system and one or more linear alpha olefins, wherein the number of carbon atoms of the linear alpha olefins ranges from 4 to 20. The metallocene catalyst system includes at least one metallocene catalyst, and the metallocene catalyst is an inorganic-organic complex containing at least one cyclopentadienyl or cyclopentadienyl derivative as a ligand and at least one IVB group transition element as a central atom. Preferably, the central atom is selected from zirconium (Zr).

[0022] Preferably, the reaction time of the ring-opening reaction is at least 2 hours, wherein the reaction end point is when the acid value of the reaction mixture is less than 10 mgKOH / g.

[0023] In a third aspect, a tackifying resin composition comprises the rosin resin described above.

[0024] Furthermore, a tackifying resin composition includes: a hydrocarbon resin and / or a natural or modified rosin resin and the rosin resin described above.

[0025] Wherein, the hydrocarbon resin includes resins derived from unsaturated hydrocarbons obtained from petroleum fractions by polymerization and related methods, including: aliphatic hydrocarbon resins, alicyclic hydrocarbon resins, aliphatic / aromatic hydrocarbon resins, alicyclic / aromatic hydrocarbon resins, and specific types of hydrocarbon resins include: C5 petroleum resin, C9 petroleum resin, terpene resin, coumarone-indene resin, etc. The softening point of the hydrocarbon resin is not less than 80°C when measured by the method of ASTM E-28. Preferably, the softening point of the hydrocarbon resin is not less than 85°C when measured by the method of ASTM E-28. More preferably, the softening point is in the range of 85-100°C when measured by the method of ASTM E-28.

[0026] The natural or modified rosin resin includes unmodified natural rosin resin and modified rosin resin, and the modified rosin resin includes polymerized rosin resin, hydrogenated rosin resin, disproportionated rosin resin, polyol-modified rosin resin and maleic rosin resin, etc. The softening point of the natural or modified rosin resin is not less than 80° C. as measured by ASTM E-28. Preferably, the softening point of the natural or modified rosin resin is not less than 85° C. as measured by ASTM E-28. More preferably, the softening point is in the range of 85-100° C. as measured by ASTM E-28.

[0027] Preferably, the above-mentioned tackifying resin composition comprises alicyclic hydrocarbon resin and the above-mentioned rosin resin.

[0028] More preferably, the above-mentioned tackifying resin composition comprises Eastotac H-100 or Piccolite C-85 and the above-mentioned rosin resin.

[0029] A fourth aspect is the application of the above-mentioned tackifying resin composition in the field of adhesives.

[0030] In a fifth aspect, a hot melt pressure-sensitive adhesive composition comprises, based on the total weight of the hot melt pressure-sensitive adhesive, 30-50wt% of a thermoplastic elastomer, 30-50wt% of the above-mentioned tackifying resin composition, 15-30wt% of a plasticizer, and 0.1-5wt% of an antioxidant.

[0031] Among them, the thermoplastic elastomer is selected from styrene block copolymers, and the styrene block copolymers include: (styrene-isoprene) block copolymer (SI), (styrene-butadiene) block copolymer (SB), (styrene-isoprene-styrene) block copolymer (SIS), (styrene-butadiene-styrene) block copolymer (SBS), (styrene-(ethylene / propylene)) block copolymer (SEP), (styrene-(ethylene / butylene)) block copolymer (SEB), (styrene-(ethylene / propylene)-styrene) block copolymer (SEPS), (styrene-(ethylene / butylene)-styrene) block copolymer (SEBS), (styrene-(ethylene / ethylene / propylene)) block copolymer (SEEP) or (styrene-(ethylene / ethylene / propylene)-styrene) block copolymer (SEEPS) One or more combinations thereof.

[0032] Preferably, the thermoplastic elastomer is a (styrene-isoprene-styrene) block copolymer (SIS).

[0033] Preferably, the configuration of the styrenic block copolymer includes linear, multi-branched or star-shaped, wherein the chemical composition of the branch chain or arm can be the same or different from that of the main chain.

[0034] The plasticizer is selected from: one or more combinations of naphthenic oil, white mineral oil, liquid paraffin and dibutyl phthalate (DOP). Preferably, the plasticizer is naphthenic oil.

[0035] The antioxidant is selected from hindered phenol antioxidants. Preferably, the antioxidant is selected from one or a combination of Irganox 1010 and Irganox 1076. More preferably, the antioxidant is Irganox 1010.

[0036] In a sixth aspect, the method for preparing the hot melt pressure-sensitive adhesive composition described above comprises: uniformly mixing raw materials such as a thermoplastic elastomer, a tackifying resin composition, a plasticizer and an antioxidant at a certain temperature.

[0037] The temperature is 80-180°C, preferably, the temperature is 120-180°C.

[0038] Preferably, an inert gas or nitrogen is introduced during the mixing process.

[0039] Preferably, the tackifying resin composition, the plasticizer and the antioxidant are first mixed evenly, and then the thermoplastic elastomer is added to the mixture in batches for mixing.

[0040] In a seventh aspect, a product comprises: a flexible substrate and a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer is formed by coating the above-mentioned hot-melt pressure-sensitive adhesive composition onto the flexible substrate.

[0041] Wherein, the flexible substrate includes: polymer film, paper or non-woven fabric; the polymer film includes: any one of polyolefin film and polyester film; wherein, the polyolefin film is more preferably a BOPP film, and the polyester film is more preferably a PET film.

[0042] In an eighth aspect, a method for manufacturing the above-mentioned product comprises: coating the above-mentioned hot-melt pressure-sensitive adhesive composition onto a surface of a flexible substrate at a temperature not higher than 140°C.

[0043] Preferably, the amount of hot melt pressure sensitive adhesive applied is 10-30 g / m 2 Preferably, the amount of hot melt pressure sensitive adhesive applied is 20 g / m 2 .

[0044] Preferably, the flexible substrate may be subjected to a corona treatment prior to coating.

[0045] The invention has the beneficial effects of grafting rosin resin onto alpha olefin oligomers through a ring-opening reaction, thereby introducing long-chain alkyl groups into the rosin resin, reducing the softening point and melt viscosity of the rosin, and simultaneously the modified rosin contains polar groups such as hydroxyl groups and ester bonds, and the cohesive strength can be maintained through hydrogen bond cross-linking. The grafting reaction uses a ring-opening reaction rather than an esterification reaction, and because the epoxy group itself has ring tension and low stability, it is easier to react with the highly hindered carboxyl group in the rosin than the hydroxyl group, so the reaction temperature and reaction time requirements are lower.

[0046] The modified rosin resin alone or in combination with other high softening point tackifying resins such as hydrocarbon resins can be used in hot melt pressure sensitive adhesives to reduce the melt viscosity and coating temperature of the hot melt pressure sensitive adhesive, reduce energy consumption and construction costs, and reduce damage and aging to flexible substrates. It is particularly suitable for substrates with low heat resistance. At the same time, the addition of long-chain alkyl modified rosin resin also improves the viscoelasticity of the pressure sensitive adhesive system and improves the wettability of the pressure sensitive adhesive. Adding 5-10wt% of low softening point rosin resin in combination with other high softening point tackifying resins can further improve the peel strength and initial adhesion of the hot melt pressure sensitive adhesive. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is the name, molecular structure and CAS number of rosin resin acid.

[0048] Figure 2 This is the infrared spectrum of butene-decene oligomers and epoxidized butene-decene oligomers. DETAILED DESCRIPTION

[0049] In conjunction with the embodiments of the present invention, the technical solutions in the embodiments are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. It should be noted that the terms used here are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0050] If the specific experimental conditions are not specified in the examples, they are usually based on the conventional conditions in the field or the conditions recommended by the reagent company; the materials, reagents, etc. used in the examples can be purchased through commercial channels unless otherwise specified.

[0051] Example 1

[0052] Preparation of epoxidized alpha olefin oligomers:

[0053] The coordination polymerization of linear α-olefins was carried out in a 2000 mL PARR high-pressure stirred reactor. The reactor was first heated to above 100°C and vacuum-baked for 1 hour, during which it was replaced with high-purity nitrogen several times to remove water / oxygen impurities in the reactor. Subsequently, the temperature of the reactor was adjusted to a reaction temperature of 70°C by circulating cooling water in the jacket, and 800 mL of 1-octene (C8α olefin) was added. The stirring rate was turned on at 500 rpm. After stirring for 15 min, the main catalyst bis(tetramethylcyclopentadienyl)zirconium dichloride (CAS No.: 119445-90-8) dissolved in 350 mL of n-hexane and the co-catalyst methylaluminoxane (MAO) were added to the reactor. The concentration of the metallocene main catalyst in the reaction system was 0.3 mmol / L (in terms of Zr), and the concentration of MAO in the reaction system was 60 mmol / L (in terms of Al), wherein the ratio of Al to Zr was 200:1. The nitrogen valve was opened to fill the nitrogen pressure to 0.2 MPa. The reaction was terminated after 1 h of reaction. The vent pipe was opened to release the pressure, and the crude product was discharged from the reactor. 20 mL of acidified ethanol was added to the crude product to terminate the reaction, and 3 wt% activated clay was used to adsorb and remove the catalyst residue, and then the filtrate was filtered under pressure to obtain the filtrate, and the filtrate was subjected to reduced pressure distillation, and 140g of the fraction at 100-120°C was collected under a vacuum degree of 0.8 torr, which was the separated C8 dimer C 16 H 32。

[0054] 140g of C8 dimer, 88wt% of formic acid aqueous solution, 30wt% of hydrogen peroxide aqueous solution, 70wt% of sulfuric acid aqueous solution and solvent ethyl n-propyl ether were added in a mass ratio of 1:0.13:0.7:0.02:0.7, and the reaction was stirred at 70°C for 4h. After the reaction was completed, the liquid in the reaction bottle was rotary evaporated to remove the azeotrope of water and ethyl n-propyl ether, and then purified by column chromatography, wherein the eluent used in the chromatography column was petroleum ether / ethyl acetate in a volume ratio of 10:1, and finally 135g of purified epoxidized C8 dimer was obtained.

[0055] Preparation of low softening point rosin resin:

[0056] The rosin raw material is selected from first-grade horsetail rosin, which has a light yellow appearance, an effective content of rosin resin acid greater than 93wt%, a softening point of 84°C measured by the ring and ball method (ASTM E-28), an acid value of 165mgKOH / g, and an unsaponifiable matter content less than 3wt%.

[0057] 160g of rosin and 135g of epoxidized C8 dimer were put into a reaction container, and 1.5g of catalyst hexadecyltrimethylammonium bromide (CTAB) was added, and the temperature was raised to 120°C for reaction for 1 hour, and then raised to 140°C for reaction. After the reaction for 1 hour, the acid value of the reaction mixture was titrated until the acid value of the reaction mixture was lower than 10 mgKOH / g, which was considered to have reached the reaction end point. The temperature was then lowered to terminate the reaction, and the excess epoxidized C8 dimer was removed by reduced pressure distillation to obtain 267g of modified rosin resin, and the softening point thereof was 53°C as tested by the ring and ball method (ASTM E-28).

[0058] Example 2

[0059] Preparation of epoxidized alpha olefin oligomers:

[0060] The coordination polymerization of linear α-olefins was carried out in a 2000 mL PARR high-pressure stirred reactor. The reactor was first heated to above 100°C and vacuum-baked for 1 hour, during which it was replaced with high-purity nitrogen several times to remove water / oxygen impurities in the reactor. Subsequently, the temperature of the reactor was adjusted to 80°C by circulating the jacket cooling water, and 800 mL of 1-decene (C10α olefin) was added. The stirring rate was turned on at 500 rpm. After stirring for 15 min, the main catalyst bis(tetramethylcyclopentadienyl)zirconium dichloride (CAS No.: 119445-90-8) dissolved in 350 mL of n-hexane and the co-catalyst methylaluminoxane (MAO) were added to the reactor. The concentration of the metallocene main catalyst in the reaction system was 0.3 mmol / L (in terms of Zr), and the concentration of MAO in the reaction system was 30 mmol / L (in terms of Al), wherein the ratio of Al to Zr was 100:1. The nitrogen valve was opened to fill the nitrogen pressure to 0.2 MPa. The reaction was terminated after 1 h of reaction. The vent pipe was opened to release the pressure, and the crude product was discharged from the reactor. 20 mL of acidified ethanol was added to the crude product to terminate the reaction, and 3 wt% activated clay was used to adsorb and remove the catalyst residue, and then the filtrate was filtered under pressure to obtain the filtrate, and the filtrate was subjected to reduced pressure distillation, and 125g of the fraction at 110-130°C was collected under a vacuum degree of 0.5 torr, which was the separated C10 dimer C 20 H 40。

[0061] 125g of C10 dimer, 88wt% of formic acid aqueous solution, 30wt% of hydrogen peroxide aqueous solution, 70wt% of sulfuric acid aqueous solution and solvent ethyl n-propyl ether were added in a mass ratio of 1:0.13:0.7:0.02:0.7, and the reaction was stirred at 70°C for 4h. After the reaction was completed, the liquid in the reaction bottle was rotary evaporated to remove the azeotrope of water and ethyl n-propyl ether, and then purified by column chromatography, wherein the eluent used in the chromatography column was petroleum ether / ethyl acetate in a volume ratio of 10:1, and finally 116g of purified epoxidized C10 dimer was obtained.

[0062] Preparation of low softening point rosin resin:

[0063] The rosin raw material is selected from first-grade horsetail rosin, which has a light yellow appearance, an effective content of rosin resin acid greater than 93wt%, a softening point of 84°C measured by the ring and ball method (ASTM E-28), an acid value of 165mgKOH / g, and an unsaponifiable matter content less than 3wt%.

[0064] 105g of rosin and 116g of epoxidized C10 dimer were put into a reaction container, and 1.1g of catalyst hexadecyltrimethylammonium bromide (CTAB) was added, and the temperature was raised to 130°C for reaction for 1 hour, and then raised to 150°C for reaction. After the reaction for 1 hour, the acid value of the reaction mixture was titrated until the acid value of the reaction mixture was lower than 10 mgKOH / g, which was considered to have reached the reaction end point. The temperature was then lowered to terminate the reaction, and the excess epoxidized C10 dimer was removed by reduced pressure distillation to obtain 191g of modified rosin resin, and the softening point thereof was 48°C as tested by the ring and ball method (ASTM E-28).

[0065] Example 3

[0066] Preparation of epoxidized alpha olefin oligomers:

[0067] The coordination polymerization of linear α-olefins was carried out in a 2000 mL PARR high-pressure stirred reactor. The reactor was first heated to above 100°C and vacuum-baked for 1 hour, during which it was replaced with high-purity nitrogen several times to remove water / oxygen impurities in the reactor. Subsequently, the temperature of the reactor was adjusted to a reaction temperature of 60°C by circulating cooling water in the jacket, and 200 mL of 1-decene (C10 α olefin) and 200 mL of n-hexane were added respectively. The stirring rate was turned on at 600 rpm. After stirring for 15 min, the main catalyst bis(tetramethylcyclopentadienyl)zirconium dichloride (CAS No.: 119445-90-8) dissolved in 60 mL of n-hexane and the co-catalyst methylaluminoxane (MAO) were added to the reactor. The concentration of the metallocene main catalyst in the reaction system was 0.3 mmol / L (in terms of Zr), and the concentration of MAO in the reaction system was 30 mmol / L (in terms of Al), wherein the ratio of Al to Zr was 100:1. 480 g of n-butene was introduced into the reactor by a horizontal flow pump, and the nitrogen valve was opened to fill the nitrogen pressure to 0.5 MPa. The reaction was terminated after 1.5 h of reaction, and the vent pipe was opened to release the pressure, and the crude product was discharged from the reactor. 20 mL of acidified ethanol was used to terminate the reaction, and then 3 wt% of activated clay was added to adsorb and remove the catalyst residue. The filtrate was then filtered under pressure to obtain a filtrate, which was subjected to reduced pressure distillation. The solvent and unreacted light components were first evaporated at 3 torr and 70°C, and 230 g of the fraction at 80-110°C was collected at a vacuum degree of 0.5 torr. This fraction was the separated butene-decene oligomer. This part of the oligomer can be divided into C14 component, C16 component and C18 component by GC-MS test, and the corresponding molecular formula is C 14 H 28 , C 16 H 32 With C 18 H 36 The butene-decene oligomers were tested by infrared spectroscopy using Nicolet FTIR. The results are as follows: Figure 2 As shown, at 3040 and 1710cm -1 The characteristic absorption peaks of C=CH and C=C in the unsaturated double bonds were found, indicating that the butene-decene oligomer contains carbon-carbon double bonds.

[0068] 230g of butene-decene oligomers, 88wt% of formic acid aqueous solution, 30wt% of hydrogen peroxide aqueous solution, 70wt% of sulfuric acid aqueous solution and solvent ethyl n-propyl ether were added in a mass ratio of 1:0.13:0.7:0.02:0.7, and stirred at 70°C for 4h. After the reaction was completed, the liquid in the reaction bottle was rotary evaporated to remove the azeotrope of water and ethyl n-propyl ether, and then purified by column chromatography, wherein the eluent used in the chromatography column was petroleum ether / ethyl acetate in a volume ratio of 10:1, and finally 220g of purified epoxidized butene-decene oligomers were obtained.

[0069] The epoxidized butene-decene oligomer was tested by infrared spectroscopy using Nicolet FTIR. The results are as follows: Figure 2 As shown, it was found that the -1 and 1600~1750cm -1 There is no obvious absorption peak at 900~930cm -1 A sharp absorption peak appears at the position, which is the absorption peak of the epoxy group. After the above-mentioned epoxidation reaction, the unsaturated double bonds in the butene-decene oligomer are oxidized to epoxy groups.

[0070] Preparation of low softening point rosin resin:

[0071] The rosin raw material is selected from first-grade horsetail rosin, which has a light yellow appearance, an effective content of rosin resin acid greater than 93wt%, a softening point of 84°C measured by the ring and ball method (ASTM E-28), an acid value of 165mgKOH / g, and an unsaponifiable matter content less than 3wt%.

[0072] 210g of rosin and 220g of epoxidized butene-decene oligomers were put into a reaction container, and 2.0g of catalyst hexadecyltrimethylammonium bromide (CTAB) was added, and the temperature was raised to 130°C for reaction for 1 hour, and then raised to 150°C for reaction. After the reaction for 1 hour, the acid value of the reaction mixture was titrated until the acid value of the reaction mixture was lower than 10 mgKOH / g, which was considered to have reached the reaction end point. The temperature was then lowered to terminate the reaction, and the excess epoxidized butene-decene oligomers were removed by reduced pressure distillation to obtain 372g of modified rosin resin, and the softening point thereof was 56°C as tested by the ring and ball method (ASTM E-28).

[0073] In order to further evaluate the application performance of the low softening point rosin resin prepared in Examples 1-3 in the field of hot melt adhesives, the corresponding hot melt pressure-sensitive adhesive composition was further prepared, and the preparation method thereof included: adding a tackifying resin composition, a plasticizer and an antioxidant to a mixing kettle, heating and introducing nitrogen, starting stirring when the tackifying resin composition is basically melted, adding a thermoplastic elastomer in three batches, heating the mixing kettle to 150°C until all the thermoplastic elastomers are completely melted, and then vacuum removing the foam in the molten system, continuing stirring for 15 minutes, and stopping stirring and heating when the entire system becomes a uniform and transparent liquid, and cooling the hot melt pressure-sensitive adhesive composition and placing it in a coating machine for standby use.

[0074] The thermoplastic elastomer is styrene-isoprene-styrene block copolymer SIS-1106, which has a linear configuration, a block ratio of styrene to isoprene (S / B) of 15 / 85, and a copolymer tensile strength of 15 MPa. It comes from Baling Petrochemical.

[0075] The hydrocarbon resin used in the tackifying resin composition in Examples 4-15 and Comparative Examples 1 and 2 includes:

[0076] Eastotac H-100, referred to as H-100, is an alicyclic hydrocarbon resin with a softening point of 100°C as tested by ASTM E-28, from Eastman Chemical Company.

[0077] Piccolite C-85, referred to as C-85, is a terpene resin with a softening point of 85°C tested by ASTM E-28, from Ashland Chemical Company.

[0078] Modified rosin resin, Examples 1-3 are self-made.

[0079] Plasticizer: Naphthenic oil KN4010, from PetroChina Karamay Refinery.

[0080] Antioxidant: Irganox 1010, a hindered phenolic antioxidant from Ciba Specialty Chemicals.

[0081] The mass ratio of thermoplastic elastomer: tackifying resin composition: plasticizer: antioxidant in the hot melt pressure-sensitive adhesive composition of Examples 4-18 and Comparative Examples 1-2 is fixed at 37:40:22.5:0.5. Among them, different examples and comparative examples have different components and ratios of low softening point rosin resin and hydrocarbon resin in the tackifying resin composition, and the amounts of the two resins are specifically listed in Table 1.

[0082] Table 1

[0083]

[0084] Test part:

[0085] The melt viscosity of the hot melt pressure-sensitive adhesive was determined using a Brooke rotational viscometer with reference to the standard HG / T 3660-1999 (method A). The prepared hot melt pressure-sensitive adhesive sample was placed in a crucible, and the crucible was placed in a silicone oil bath. The oil bath temperature was controlled at 140±2°C. When the colloid was melted, the standard rotor groove of the viscometer was partially immersed in the hot melt pressure-sensitive adhesive sample to test the viscosity.

[0086] The hot melt pressure-sensitive adhesive compositions of Examples 4-15 were melted at 140°C, Examples 16-18 with too low melt viscosity at 140°C were melted at 125°C, and Comparative Examples 1 and 2 with too high melt viscosity at 140°C were melted at 170°C, and then uniformly coated on the corona-treated PET substrate, with a coating amount of 20 g / m 2 The initial ring adhesion of the coated adhesive tape was measured according to the standard GB / T31125-2014 (method A). The holding force was measured according to the standard GB / T4851-2014 (method A) after bonding to the stainless steel plate. The 180° peel strength between the adhesive tape and the stainless steel plate was measured according to the standard GB / T2792-2014. The peeling speed in the peel strength test was 300 mm / min.

[0087] The test results of the hot melt pressure-sensitive adhesive compositions of Examples 4-18 and Comparative Examples 1 and 2 are shown in Table 2.

[0088] Table 2

[0089]

[0090] The modified rosin resin prepared in Examples 1-3 has long-chain alkyl grafted onto the rosin molecules. The long-chain alkyl has stronger mobility, reduces the interaction between macromolecules, expands the free volume of the entire hot melt pressure-sensitive adhesive system, and increases the mobility of the chain segments, thereby giving the hot melt pressure-sensitive adhesive system lower viscosity and better low-temperature fluidity. At the same time, it also improves the viscoelasticity of the system and improves the wettability of the pressure-sensitive adhesive. Therefore, it can be seen from Table 2 that Examples 16-18 using the modified rosin resin alone have lower melt viscosity and higher initial tack than commercial tackifying resins H-100 and C-85. However, after the introduction of long-chain alkyl groups, the compatibility of the modified rosin resin with the thermoplastic elastomer in the hot-melt pressure-sensitive adhesive system is reduced, and the proportion of the ternary phenanthrene ring skeleton in the rosin molecule is reduced, resulting in a significant decrease in the peel strength and cohesive strength of the pressure-sensitive adhesive system. By comparison, it can be found that the holding force and peel strength of the pressure-sensitive adhesive of Example 16, which uses the rosin resin prepared in Example 1 alone as a tackifying resin, are significantly inferior to those of the pressure-sensitive adhesives of Examples 4 and 5, which use H-100, C-85 and the rosin resin prepared in Example 1 as a tackifying resin.

[0091] On this basis, the present application uses the modified rosin resin prepared in Examples 1-3 in combination with commercial tackifying resins H-100 and C-85 through Examples 4-15, which can not only reduce the melt viscosity and coating temperature of the hot melt pressure-sensitive adhesive, but also improve its peel strength and initial adhesion.

[0092] Combining the formula ratio in Table 1 with the experimental results in Table 2, the hot melt pressure-sensitive adhesive with the addition of 5-10wt% modified rosin resin not only reduces the melt viscosity, but also has a melt viscosity of about 2000-5000mPa·s at 140°C, which is easy to coat. Therefore, the temperature of the coating process is reduced, energy consumption and coating costs are reduced, and damage and aging to flexible substrates are reduced, which is particularly suitable for substrates with low heat resistance.

[0093] At the same time, the initial adhesion and peel strength of the hot melt pressure sensitive adhesive are also improved. After the addition amount of modified rosin resin is increased to 20wt%, the melt viscosity of the hot melt pressure sensitive adhesive continues to decrease, but the initial adhesion and peel strength also show a significant decrease. This is because the introduction of long-chain alkyl groups into the modified rosin resin can improve the viscoelasticity and wetting ability of the pressure sensitive adhesive system, thereby improving its initial adhesion and peel strength. However, this long-chain alkyl group has poor compatibility with thermoplastic elastomers, and excessive addition of modified rosin resin leads to a decrease in the relative proportion of ternary phenanthrene rings in the rosin molecule. Therefore, excessive addition of modified rosin resin is not conducive to the initial adhesion and peel strength of the pressure sensitive adhesive. The effect of modified rosin resin on the holding force is that the long-chain alkyl group has a destructive effect on the crystallization ability of rosin resin, so it has a reducing effect on the cohesive strength of the pressure sensitive adhesive system, but the polar groups such as hydroxyl groups and ester bonds contained in the epoxy ring opening can also maintain a certain cohesive strength through hydrogen bonding, so that the holding force will not drop significantly. From the experimental results in Table 2, it can be concluded that the comparative examples 1 and 2 which do not use modified rosin resin at all have the highest holding force, and the higher the amount of modified rosin resin added, the greater the decrease in the holding force of the pressure-sensitive adhesive.

[0094] In summary, although the use of modified rosin resin alone can significantly reduce the melt viscosity of hot melt pressure-sensitive adhesives, and the ring initial adhesion is the best, the corresponding holding force and peel strength are obviously not as good as those of hot melt pressure-sensitive adhesives using similar tackifying resins. Therefore, by using modified rosin resin in combination with other hydrocarbon or terpene tackifying resins, the viscoelasticity, wetting performance, cohesive strength and interfacial strength of the pressure-sensitive adhesive system can be balanced to obtain a hot melt pressure-sensitive adhesive product with initial adhesion, holding force and peel strength that meet the requirements. At the same time, the melt viscosity of the hot melt pressure-sensitive adhesive can also be reduced, which is conducive to melting and coating at 140°C.

[0095] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to perform equivalent replacements on parts thereof. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention. Although the above describes the specific implementation methods of the present invention, it is not intended to limit the protection scope of the present invention. Those skilled in the art should understand that, based on the technical solution of the present invention, various modifications or deformations that can be made by those skilled in the art without creative labor are still within the protection scope of the present invention.

Claims

1. A rosin resin, characterized in that Obtained by reacting epoxidized alpha olefin oligomers with rosin; The softening point of the rosin resin is not higher than 65° C. as measured by ASTM E-28. The degree of polymerization of the epoxidized alpha olefin oligomer is 2-4, and the structure of the epoxidized alpha olefin oligomer includes: , or One or more of; wherein a, b, c and d are independent of each other and can be the same or different in value, and the value range of a, b, c and d is 1-17; Rosin is a mixture of various rosin resin acids, a small amount of fatty acids and neutral substances. The acid value of rosin is not less than 155 mgKOH / g, and its softening point is not less than 75°C as measured by ASTM E-28 method.

2. The method for preparing rosin resin according to claim 1, characterized in that: The epoxidized alpha olefin oligomer and rosin undergo a ring-opening reaction in the presence of a catalyst.

3. The preparation method according to claim 2, characterized in that: The temperature of the ring-opening reaction is 100-160° C., the catalyst is an alkyl trimethyl ammonium halide, selected from: any one or a combination of n-decyl trimethyl ammonium chloride, n-decyl trimethyl ammonium bromide, dodecyl trimethyl ammonium chloride, dodecyl trimethyl ammonium bromide, tetradecyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium chloride and octadecyl trimethyl ammonium bromide, the reaction time of the ring-opening reaction is at least 2 hours, wherein the reaction endpoint of terminating the reaction is until the acid value of the reaction mixture is lower than 10 mgKOH / g.

4. A tackifying resin composition, characterized in that Contains the rosin resin according to claim 1.

5. A tackifying resin composition, characterized in that include: Hydrocarbon resin and / or natural or modified rosin resin and the rosin resin according to claim 1; The hydrocarbon resin includes resins derived from unsaturated hydrocarbons obtained from petroleum fractions by polymerization and related methods, including: aliphatic hydrocarbon resins, alicyclic hydrocarbon resins, aliphatic / aromatic hydrocarbon resins, alicyclic / aromatic hydrocarbon resins, and the softening point of the hydrocarbon resin is not less than 80°C as measured by ASTM E-28 method; The natural or modified rosin resin includes unmodified natural rosin resin or modified rosin resin, and the modified rosin resin includes polymerized rosin resin, hydrogenated rosin resin, disproportionated rosin resin, polyol-modified rosin resin and maleic rosin resin. The softening point of the natural rosin resin or modified rosin resin is not less than 80° C. as measured by ASTM E-28 method.

6. Use of the tackifying resin composition according to any one of claims 4 and 5 in the field of adhesives.

7. A hot melt pressure-sensitive adhesive composition, characterized in that: Based on the total weight of the hot melt pressure-sensitive adhesive, the composition comprises: 30-50wt% of a thermoplastic elastomer, 30-50wt% of a tackifying resin composition according to any one of claims 4 and 5, 15-30wt% of a plasticizer, and 0.1-5wt% of an antioxidant; Wherein, the thermoplastic elastomer is selected from styrene block copolymers, and the styrene block copolymers include: (styrene-isoprene) block copolymer, (styrene-butadiene) block copolymer, (styrene-isoprene-styrene) block copolymer, (styrene-butadiene-styrene) block copolymer, (styrene-(ethylene / propylene)) block copolymer, (styrene-(ethylene / butylene)) block copolymer, (styrene-(ethylene / propylene)-styrene) block copolymer, (styrene-(ethylene / butylene)-styrene) block copolymer, (styrene-(ethylene / ethylene / propylene)) block copolymer or (styrene-(ethylene / ethylene / propylene)-styrene) block copolymer or one or more combinations thereof; The plasticizer is selected from one or more combinations of naphthenic oil, white mineral oil, liquid paraffin and dibutyl phthalate; The antioxidant is selected from hindered phenol antioxidants.

8. The method for preparing the hot melt pressure sensitive adhesive composition according to claim 7, characterized in that: include: The thermoplastic elastomer, the tackifying resin composition, the plasticizer and the antioxidant are uniformly mixed at a certain temperature, wherein the temperature is 80-180°C.

9. A product, characterized in that include: A flexible substrate and a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer is formed by coating the hot-melt pressure-sensitive adhesive composition according to claim 7 onto the flexible substrate; Wherein, the flexible substrate includes: polymer film, paper or non-woven fabric; the polymer film includes: any one of polyolefin film and polyester film.

10. A method for manufacturing the product according to claim 9, comprising: The hot melt pressure-sensitive adhesive composition according to claim 7 is coated on the surface of a flexible substrate at a temperature not higher than 140°C.

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