Improving adhesion of fibrous materials in rubber composites

Abstract

The present invention provides the use of a hydrophobized polyethyleneimine for improving the adhesion of a fibrous material to rubber in a rubber composite, wherein the hydrophobized polyethyleneimine has been hydrophobized to provide a substituent bearing one or more pendant reactive groups. Included in the present invention are: a method for improving the adhesion of a fibrous material to rubber in a rubber composite; a coated fibrous material comprising a coated hydrophobized polyethyleneimine; a rubber composite comprising a rubber and a fibrous material wherein the fibrous material has a coating of a hydrophobized polyethyleneimine; methods for producing the coated fibrous material and for producing the rubber composite; and aqueous formulations suitable for use as impregnation solutions for improving the adhesion of fibrous material to rubber in rubber composites.

Description

Technical Field

[0001] The present invention generally relates to improving the adhesion of fiber materials in rubber composites. Specifically, the present invention relates to the use of hydrophobized polyethyleneimine for improving the adhesion of fiber materials to rubber in rubber composites. Included in the present invention are: a method for improving the adhesion of fiber materials to rubber in rubber composites; a coated fiber material comprising a coated hydrophobized polyethyleneimine; a rubber composite comprising rubber and fiber material, wherein the fiber material has a coating of the hydrophobized polyethyleneimine; a method for producing the coated fiber material and for producing the rubber composite; and an aqueous formulation suitable for use as an impregnation solution for improving the adhesion of fiber materials to rubber in rubber composites. Background Art

[0002] In the field of rubber composites, fiber cords and woven fabrics are usually mixed to improve the structural rigidity of composite material systems. These fiber cords and woven fabrics are usually made of polar chemical structures, which makes them chemically incompatible with the non-polar structure in rubber. In order to prevent the separation of these two completely different structures (i.e. fiber cords / woven fabrics and rubber), common practice is to adopt adhesive systems. Typically, this adhesive system is resorcinol-formaldehyde-latex (RFL), which is usually used for dip coating and then the adhesive solution is dried to the fiber component and is given in the composite material. Then by vulcanization process, rubber is attached to the fiber component, thereby forming final rubber composite.

[0003] While resorcinol-formaldehyde based resins have long remained the state of the art, recent advances in environmental and health research have led to the classification of resorcinol and formaldehyde as unsafe chemical compounds. As a result, the rubber industry is currently seeking RFL-free adhesive systems for the manufacture of rubber composites.

[0004] US Patent Publication 2017 / 0130396A1 describes a formaldehyde-free and resorcinol-free impregnation solution for cord fabrics. The method described therein includes forming an impregnation solution by adding an acrylic polymer resin to water, adjusting the pH, adding an epoxy resin to the composition, adding a polyisocyanate to the composition and then adding latex to obtain an impregnation solution. Synthetic fibers and rubber used in the rubber material reinforced by the cord fabric can be attached to each other by providing an interface between the two materials. The method is said to be less dangerous to human health than RFL and is also environmentally friendly.

[0005] US Patent Publication 2020 / 0140657A1 discloses a coated fiber for polymer reinforcement. The coated fiber comprises a fiber and a coating arranged around the fiber. The fiber has a denier of about 250 to about 3,000, and the coating comprises a branched polyethyleneimine. This document also describes a composite material comprising: a polymer comprising a thermoplastic, an elastomer, or a thermoplastic elastomer; and the coated fiber described above.

[0006] Despite these developments, there remains a need to provide a viable RFL-free adhesive system for rubber composites containing fibrous material reinforcement components having improved adhesion characteristics.

[0007] It is known to incorporate various additives into rubber with the goal of improving different properties. For example, EP 2810956, EP1866368 and GB 953350 disclose silicone rubber / nitrile rubber mixtures containing triethanolamine. CN 103601925 and CN 103554891 disclose mixtures containing specific rubbers, triethanolamine and optionally methyltriethoxysilane. Other additives include diphenylguanidine used as an accelerator in rubber mixtures (H.-d. Luginsland, A review on the chemistry and reinforcement of the silica silane filler system for rubber applications, Shaker Publishing House, Aachen, 2002, page 49).

[0008] Japanese patent application No. JP 2001003273 A describes a polyester fiber for reinforcing rubber, the polyester fiber being provided with polyethyleneimine and an epoxy compound on its surface. The polyester fiber is said to have improved adhesion properties.

[0009] Japanese Patent Application No. JP H11222779 discloses a processing agent for polyester fibers, which contains polyethyleneimine, poly-N-vinylformamide or poly-N-vinylacetamide. It is claimed that the adhesion between the fibers and rubber is improved.

[0010] US Patent No. 3,597,265 relates to passing fibers coated with a lubricant comprising a partially amidated polyalkyleneimine having a residual amine value of about 200 to 804 by reacting a polyalkyleneimine having a molecular weight of 800 to about 50,000 with a fatty acid.

[0011] U.S. Patent Application No. 2002 / 0017627A1 relates to a polymer derivative comprising a polyalkyleneimine backbone having a plurality of reactive amino functional groups, each of which has at least one reactive hydrogen atom. About 20% to about 60% of the number of reactive amino functional groups have a substituent compound substituted in place of at least one reactive distributing atom. Each substituent compound is said to be independently selected from the group consisting of: a carboxylic acid having about 14 to about 20 carbon atoms.

[0012] U.S. Patent Application No. 2002 / 0028910A1 describes a polymer derivative comprising a polyalkyleneimine backbone having a plurality of reactive amino functional groups. Each reactive amino functional group is said to have at least one reactive hydrogen atom. Eight stabilizing effective amounts of the reactive amino functional groups have a substituent compound substituted in place of at least one reactive hydrogen atom, the substituent compound being independently selected from the group consisting of a carboxylic acid and an amine protection compound. This indicates that at least about 20% of the reactive amino functional groups have a carboxylic acid substituted in place of at least one reactive hydrogen atom.

[0013] U.S. Patent Application No. 2004 / 0139559A1 discloses a method for wrinkle-proofing cellulosic textiles, which comprises treating these textiles with a finishing agent and testing these treated textiles. The finishing agent is said to contain one or more water-soluble or water-dispersible hydrophobically modified polyethyleneimines and / or polyvinylamines. Suitable hydrophobically modified polyethyleneimines are said to be hydrophobically modified homopolymers of ethyleneimine, hydrophobically modified graft polymers of polyamidoamines, or hydrophobically modified graft polymers of polyvinylamines. Suitable hydrophobically modified polyvinylamines are homopolymers or copolymers of at least partial hydrolysis of hydrophobically modified N-vinylformamide. Polyethyleneimines and polyvinylamines can be cross-linked by multifunctional cross-linking compounds, quaternized and / or modified by reacting with alkylene oxides, dialkyl carbonates, and / or C1-C4 carboxylic acids. Suitable hydrophobizing agents are selected from the group consisting of long-chain linear or branched carboxylic acids, linear or branched alkyl halides, alkyl epoxides, alkyl ketene dimers, cyclic dicarboxylic acid anhydrides, alkyl isocyanates and chloroformates of fatty alcohols.

[0014] Japanese patent application No. JP 2016033170 claims a method for producing latex foam, wherein polyethyleneimine and / or polyethyleneimine derivatives are further added to the rubber latex. The polyethyleneimine derivatives are said to include epoxy-modified polyethyleneimine obtained by reacting polyethyleneimine with an epoxy compound such as epichlorohydrin, and acrylic acid-modified polyethyleneimine obtained by reacting polyethyleneimine with an acrylic compound such as acrylonitrile, alkylated polyethyleneimine, halogen-modified polyethyleneimine reacted with a halogen compound such as a halide, isocyanate-modified polyethyleneimine modified by reacting polyethyleneimine with an isocyanate compound such as an alkyl isocyanate, fatty acid-modified polyethyleneimine obtained by reacting polyethyleneimine with a fatty acid, and the like.

[0015] U.S. Pat. No. 11,059,961 B2 describes an additive for rubber mixtures which is said to avoid the release of amines and to achieve a high crosslink density. The rubber mixture is said to contain at least one rubber and at least one silane of the formula G-Si(-OR)3, wherein G is a monovalent, unbranched or branched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic / aromatic (C2-C 16 )-, and R is the same or different and is a linear unsubstituted or branched unsubstituted (C1-C 10 )-alkyl.

[0016] U.S. Patent No. 9,499,714B2 relates to the crosslinking of latex polymers with multifunctional amines. This reference describes a latex polymer composition, such as a latex, dispersion, microemulsion or suspension. The latex polymer composition can be stored at room temperature or moderately above room temperature, and provides adhesion and crosslinking after film formation when applied to a substrate. The disclosure is said to include a composition of a water-soluble polymer and an oligomeric multifunctional amine, which is used as a crosslinking agent in a solution of a fast-drying latex emulsion. The oligomeric / polymer multifunctional amine is said to be synthesized in a single-step reaction by reacting difunctional or trifunctional glycidyl and / or glycidyl isocyanurate groups with water-soluble diamines, triamines and tetraamines as starting materials (reactants), which act as crosslinking agents for latex paints. The disclosed polymers and waterborne polymer compositions are said to be useful in a variety of paint and coating formulations such as architectural coatings, cement coatings, paper coatings, inks and adhesives.

[0017] U.S. Patent No. 10,246,571 B2 discloses hydrophobically modified polyfunctional amines for controlled crosslinking of latex polymers. This reference describes the hydrophobic modification of various polyfunctional amines. One such reaction described is the synthesis of a structure in reaction 6 by reacting polyethyleneimine with a hydrophobic glycidyl ether such as butyl glycidyl ether. This structure is said to be a hydrophobically modified polyfunctional imine that is a fast dryer and is a uniform solution for modifying polyfunctional amines to crosslink latex particles. Reaction 7 describes the synthesis of oligomers by reacting polyethyleneimine with a hydrophobic acrylic monomer emulsion such as an acrylic microemulsion. The oligomers so formed are said to be hydrophobically modified polyfunctional imines that are fast dryers. The disclosed polymers and aqueous polymer compositions are said to be useful in a variety of paint and coating formulations such as architectural coatings, cement coatings, paper coatings, inks, and adhesives.

[0018] US Patent No. 10,377,878 B2 teaches controlled crosslinking of latex polymers with multifunctional amines. The disclosure of this reference is very similar to US 9,499,714 B2.

[0019] U.S. Pat. No. 10,851,240 B2 discloses a composition comprising a compound that can be prepared by the reaction of an optionally crosslinked polyethyleneimine and at least one amine-reactive hydrolyzable organosilane having the formula RZ-SiY3, wherein R represents an amine-reactive group containing 1-18 carbon atoms; Z represents a divalent organic group containing 1-8 carbon atoms; and each Y independently represents a hydrolyzable group. The disclosure is said to provide a reasonably stable one-pot curable PEI-derived composition that can be applied to a substrate and cured to provide a durable amine-functional coating on the substrate. The reference indicates that such a coating can be used, for example, in a chemical monitor (e.g., for monitoring exposure to aldehyde disinfectants), and / or can be used to modify the hydrophobicity and / or protect the surface of a substrate.

[0020] The literature article Multifunctional allyl-terminated hyperbranched poly(ethyleneimine) as component of new thiol-epoxy materials, Cristina Acebo et al., Reactive and Functional Polymers 99 (2016) 17-25, Elsevier, describes the synthesis and characterization of allyl-terminated hyperbranched poly(ethyleneimine). It was used as a multifunctional macromonomer in a diglycidyl ether formulation of tetrathiol-bisphenol A in different proportions.

[0021] The article Dielectric spectroscopy of novel thiol-ene / epoxy thermosets obtained from allyl-modified hyperbranched poly(ethyleneimine)and diglycidylether of bisphenol A, JD Badia et al., European Polymer Journal 113 (2019) 98-106, Elsevier Publishers describes the production of novel thermosets by a dual-cure process involving first a photochemical thiol-ene followed by a thermal thiol-epoxy, starting from allyl-terminated hyperbranched poly(ethyleneimine) and diglycidylether of bisphenol A in varying proportions and corresponding stoichiometric proportions of pentaerythritol tetrakis(3-mercaptopropionate). Summary of the invention

[0022] According to the present invention, there is provided the use of a hydrophobized polyethyleneimine for improving the adhesion of a fiber material to rubber in a rubber composite, wherein the hydrophobized polyethyleneimine has been hydrophobized to provide substituents with one or more pendant reactive groups.

[0023] The present invention also provides a method for improving the adhesion of fiber material to rubber in a rubber composite material, the method comprising the following steps:

[0024] providing an aqueous formulation comprising a hydrophobized polyethyleneimine;

[0025] contacting the fibrous material with the aqueous formulation to form a coated fibrous material; and

[0026] drying the coated fiber material,

[0027] Therein the hydrophobized polyethyleneimine has been hydrophobized to provide a substituent with one or more pendant reactive groups.

[0028] Also included in the present invention is a coated fiber material comprising a coating comprising a hydrophobized polyethyleneimine, wherein the hydrophobized polyethyleneimine has been hydrophobized to provide substituents with one or more pendant reactive groups, wherein the coated fiber material has improved adhesion to rubber in a rubber composite obtainable by a forming method.

[0029] The present invention further provides a method for producing a rubber composite material comprising rubber and a fiber material, wherein the fiber material has improved adhesion to the rubber, the method comprising the steps of:

[0030] providing an aqueous formulation comprising a hydrophobized polyethyleneimine;

[0031] contacting the fibrous material with the aqueous formulation to form a coated fibrous material;

[0032] drying the coated fiber material;

[0033] contacting the coated fiber material with the rubber and vulcanizing it to form the rubber composite,

[0034] Therein the hydrophobized polyethyleneimine has been hydrophobized to provide a substituent with one or more pendant reactive groups.

[0035] The present invention further includes a rubber composite material obtainable by the above method, comprising rubber and a fiber material, wherein the fiber material comprises a coating of a hydrophobized polyethyleneimine, wherein the hydrophobized polyethyleneimine has been hydrophobized to provide substituents with one or more pendant reactive groups, the fiber material having improved adhesion to the rubber in the rubber composite material.

[0036] In another aspect of the present invention, there is provided an aqueous formulation suitable for use as a dipping solution free of resorcinol formaldehyde latex (RFL) for improving the adhesion of fiber material to rubber in a rubber composite material, wherein the aqueous formulation comprises:

[0037] A) a hydrophobized polyethyleneimine which has been hydrophobized to provide a substituent with one or more pendant reactive groups; and

[0038] B) Latex. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The hydrophobized polyethyleneimine H-PEI sample A is shown 1 H-NMR spectrum.

[0040] Figure 2 A graph showing the average peel strength of rubber composites formed using comparative formulations 5 and 6 and formulations 7 and 9 of the present invention, all of which contain Adhesion improvers. DETAILED DESCRIPTION

[0041] The one or more side reactive groups may be any suitable reactive group that can cause crosslinking after curing (e.g., curing with heat) or during a vulcanization process. Desirably, the one or more side reactive groups may be silane groups or ethylenically unsaturated groups. Such ethylenically unsaturated groups are preferably selected from any one of allyl, propargyl, acrylic acid, or methacrylic acid groups.

[0042] Making the hydrophobic polyethyleneimine have one or more side joint reactive groups is typically achieved by making polyethyleneimine react with a reactive modifying agent to provide a side joint portion with this reactive group. Such modifying agent suitably contains a reactive group to the amine group of polyethyleneimine and another side group comprising the side joint portion containing this reactive group. Any suitable amine reactive group can be adopted. Preferably, the amine reactive group can be any one of the groups selected from epoxide, isocyanate, blocked isocyanate or anhydride.

[0043] A more preferred modifier is glycidyl allyl ether.

[0044] Suitably, the hydrophobized polyethyleneimine comprises a structure represented by formula (I):

[0045]

[0046] in

[0047] R1 represents the first fragment of the polyethyleneimine;

[0048] R2 represents the second fragment of the polyethyleneimine, or represents hydrogen or A; and

[0049] A is a hydrophobic group comprising one or more pendant reactive groups. The one or more pendant reactive groups may be any suitable reactive group that can induce crosslinking after curing (eg, curing with heat) or during the vulcanization process.

[0050] Desirably, A is a hydrophobic group derived from a hydrophobizing agent represented by formula (II):

[0051] XYZ II

[0052] wherein X represents an amine reactive group containing 1 to 6 carbon atoms with an epoxide or isocyanate group; Y represents a divalent organic group containing 1 to 8 carbon atoms; and Z represents one or more pendant reactive groups selected from silane groups or ethylenically unsaturated groups. The ethylenically unsaturated group may be any one of an allyl group, a propargyl group, an acrylic group, and a methacrylic group.

[0053] A schematic representation of a hydrophobized polyethyleneimine of formula (I) is depicted by a compound of formula (III):

[0054]

[0055] wherein A has the same definition as previously defined.

[0056] In a preferred embodiment of the hydrophobized polyethyleneimine, the hydrophobizing agent is represented by formula (II), X represents a glycidyl ether, y represents a divalent organic group containing 2 or 3 carbon atoms, and Z represents an allyl group or a silane group. The divalent organic group is desirably an alkylene group represented by any of the following:

[0057]

[0058] The hydrophobizing agent usually reacts with the primary amine and / or secondary amine of the polyethyleneimine. Straight-chain polyethyleneimine usually contains secondary amines along its chain, wherein the primary amines are distributed at the ends of the chain. Branched polyethyleneimine also contains primary amines at the ends of the branches. Typically, two moles of the hydrophobizing agent can react with each primary amine, and one mole of the hydrophobizing agent can react with each secondary amine.

[0059] The reaction between polyethyleneimine and the hydrophobizing agent can be carried out under anhydrous conditions (that is, in the absence of water).Therefore, polyethyleneimine and the hydrophobizing agent can be provided in anhydrous liquid form separately.Then the reaction can be carried out in anhydrous reaction mixture form.Alternately, the reaction between polyethyleneimine and the hydrophobizing agent can be carried out in the presence of water.In this case, polyethyleneimine and / or the hydrophobizing agent can be provided in aqueous composition form and then react together, or polyethyleneimine and the hydrophobizing agent can be merged into anhydrous reaction mixture, and then the anhydrous reaction mixture is diluted with water before reacting.In a kind of desirable form, polyethyleneimine provides as aqueous liquid, and the hydrophobizing agent is anhydrous or contains water. In a more desirable form, the reaction mixture is an aqueous reaction mixture containing up to 60% water by weight of the aqueous reaction mixture, suitably comprising greater than 0% to 60% water, for example 10% to 55% water, such as 20% to 55% water, particularly 30% to 55% water, or 40% to 55% water, such as 45% to 55% water, especially about 50% water. Carrying out the reaction in the presence of water provides the advantage that the polyethyleneimine initially produced as an aqueous liquid does not need to be rendered anhydrous by an additional processing step, which would require energy to dehydrate the aqueous polyethyleneimine. Carrying out the reaction in the form of an aqueous reaction mixture to produce a hydrophobized polyethyleneimine in an aqueous composition can also eliminate the addition of water or as much water when forming an aqueous formulation.

[0060] Preferably, the hydrophobized polyethyleneimine has a degree of functionalization of 0.2 to 1.55.

[0061] The polyethyleneimine that is suitable for forming the hydrophobizing polyethyleneimine can be prepared by the whole bag of tricks understood in the art.For example, polyethyleneimine can be prepared by the ring-opening of aziridine through acid-catalyzed polymerization.In certain embodiments, polyethyleneimine can be further modified, as by using fatty acid amidation, by using alkylene oxide alkoxylation or by modifying with acrylic acid and / or maleic acid carboxylation.Preferably, polyethyleneimine keeps unmodified before being hydrophobized with a hydrophobizing agent.

[0062] In many embodiments, the polyethyleneimine has a weight average molecular weight (MW) of about 300 to about 2,000,000 g / mol, about 400 to about 1,000,000 g / mol, about 500 to about 900,000 g / mol, about 500 to about 800,000 g / mol, about 500 to about 25,000 g / mol. w More preferably, the weight average molecular weight (M w ) is about 500 to about 15,000 g / mol, about 500 to about 10,000 g / mol, and about 500 to about 1500 g / mol.

[0063] In various desirable embodiments, the polyethyleneimine is a branched polymer comprising groups such as:

[0064]

[0065] wherein n or m is typically from about 9 to about 50,000, such that the polyethyleneimine has a weight average molecular weight (M) of about 500 to about 2,000,000 g / mol, about 400 to about 1,000,000 g / mol, about 500 to about 900,000 g / mol, about 500 to about 800,000 g / mol, about 500 to about 25,000 g / mol, about 500 to about 15,000 g / mol, about 500 to about 10,000 g / mol, and about 500 to about 1500 g / mol. w ). It is also contemplated that the polyethyleneimine may have any value or range of values ​​(both full and partial) within those ranges described above.

[0066] Preferably, the hydrophobized polyethyleneimine is derived from branched polyethyleneimine. Polyethyleneimine is a branched polymer having the following exemplary structure:

[0067]

[0068] Still referring to the above exemplary structure, the branched structure of polyethyleneimine provides primary amines, secondary amines and tertiary amines. That is, polyethyleneimine typically includes a linear group (L), a dendritic group (D), and a terminal group (T). The above exemplary structure * represents the rest of the polyethyleneimine molecule.

[0069] In some embodiments, based on 100% of all groups present in the branched polyethyleneimine, as via in D2O 13 C-NMR determines that the branched polyethyleneimine comprises: about 20% to about 55%, or about 30% to about 45% linear groups (L); about 10% to about 40%, or about 20% to about 30% dendritic groups (D); and about 20% to about 55%, or about 30% to about 45% terminal groups (T). In additional non-limiting embodiments, all values ​​and value ranges (both whole and partial) within one or more of the above ranges are expressly contemplated herein.

[0070] In many embodiments, the branched polyethyleneimine has a degree of branching (DB) of about 0.30 to about 0.85, about 0.40 to about 0.75, or about 0.60 to about 0.70, as determined by polymerization in D2O. 13The molecular weight of the ...

[0071] Suitable hydrophobized polyethyleneimines can be derived from BASF under the trade name Commercially available polyethyleneimine.

[0072] The hydrophobized polyethyleneimine is desirably formulated into an aqueous formulation. Typically, this aqueous formulation will contain latex and optionally other additives. The aqueous formulation can be applied to the fibrous material by contacting the fibrous material with the aqueous formulation. The aqueous formulation can be applied to the fibrous material by spraying it on the surface, but preferably the aqueous formulation is an impregnation solution, which can be applied to the fibrous material by submerging or dipping the fibrous material into the aqueous formulation.

[0073] The latex preferably comprises a vinylpyridine polymer. Typically, the vinylpyridine polymer is a copolymer derived from vinylpyridine, at least one other ethylenically unsaturated hydrophobic monomer, preferably selected from styrene and butadiene. Preferably, the latex is a terpolymer comprising vinylpyridine, styrene and butadiene.

[0074] Optional other additives included in the aqueous formulation, especially when the aqueous formulation is a dipping solution, include adhesion improvers. In the present invention, such adhesion improvers include compounds capable of reacting with amines. Suitably, the adhesion improver is selected from any one of epoxides, isocyanates, blocked isocyanates, anhydrides, acrylates, methacrylates or silanes. Typically, the silane is a siloxyalkyl glycidyl ether.

[0075] The hydrophobized polyethyleneimine may be present in the aqueous formulation in any suitable amount that effectively promotes adhesion between the fiber material and the rubber in the rubber composite. Preferably, the concentration of the hydrophobized polyethyleneimine in the aqueous formulation (especially when the aqueous formulation is an impregnation solution) is 2% to 27% by weight of the weight of the aqueous formulation. Based on the weight of the solid content of the aqueous formulation, the hydrophobized polyethyleneimine is present in an amount ranging from 10% to 40% by weight. This is particularly the case when the aqueous formulation is an impregnation solution.

[0076] The preferred way of applying the hydrophobized polyethyleneimine to the fibrous material is by incorporating the hydrophobized polyethyleneimine into an aqueous formulation as described above and dipping onto the fibrous material. Typically, the fibrous material is immersed in a bath of the aqueous formulation as an impregnation solution for a sufficient time to allow the adhesive coating to form on the fibrous material. Suitably, the period of immersion is any period of time that is conventional and appropriate for a specific industrial-scale coating process.

[0077] It is possible to immerse individual lengths of fiber material into a bath of the impregnation solution for the desired period of time, but on an industrial scale it is more common to use a continuous dip coating process in which the fabric material is passed continuously through the impregnation solution by means of a continuous roll-to-roll process in which the fiber material is fed into, passed through and exits the impregnation solution around rolls, which allows sufficient time for the adhesive coating to form on the surface of the fiber material.

[0078] Once the coating comprising the hydrophobized polyethyleneimine is applied to the fiber material, the coating is typically subjected to a drying phase to evaporate water and any organic liquids such as solvents. This can be achieved by subjecting the coated fiber material to an elevated temperature environment. Typically, the drying phase can be conducted at a temperature of at least 120° C. and can even be as high as 180° C. or higher. The drying phase can last for a period of time that is conventional and typical for the specific drying process employed in industrial-scale operations.

[0079] Therefore, in one aspect of the present invention, a kind of fiber material of coating is provided, it includes the coating comprising hydrophobized polyethyleneimine, wherein the fiber material of coating has the improved adhesion to rubber in rubber composite material that can be obtained by the above-mentioned method given above.The fiber material of coating suitably comprises fiber material (preferably in the form of fiber cord and / or woven fabric) and the adhesive coating containing hydrophobized polyethyleneimine arranged around the surface of the fiber material.Desirably, the fiber material component of the article can be formed by about 80% to about 99.8%, about 90% to about 99.8%, about 90% to about 99%, or about 92% to about 99% or about 93% to about 97% by weight of the gross weight of the fiber material of coating, and typically the remainder is composed of adhesive coating.In other non-limiting embodiments, all values ​​and value ranges (both whole and part) in one or more of the above-mentioned ranges are explicitly considered herein.

[0080] Typically, fiber material should be provided in the form of fiber cord and / or woven fabric.Any suitable fiber can be used to produce fiber cord or woven fabric.Suitable fiber can be selected from the group of following items: polymer fiber (such as acrylic fiber, polyamide fiber, polyester fiber, polyolefin fiber, phenol-formaldehyde / phenolic (novoloid) fiber, etc.), natural fiber (such as cellulose fiber, lignin fiber, rayon fiber, wood fiber, etc.), glass fiber (such as E-glass, A-glass, E-CR-glass, C-glass, D-glass, S-glass, etc.), ceramic fiber, metal fiber (such as stainless steel, aluminum, etc.), carbon fiber and carbon composite fiber (such as graphite fiber, fiber based on polyacrylonitrile (PAN), carbon nanotube fiber, etc.), mineral fiber (such as basalt fiber, etc.), and combination thereof.In certain embodiments, fiber is a composite fiber or multi-component fiber comprising any combination of suitable materials (polymer, metal, mineral, etc.) specified herein.The example of such composite fiber includes nickel-coated carbon fiber, silver-coated fiber and coextruded polymer fiber.

[0081] In one group of embodiments according to the present invention, the fibers forming the fiber material (e.g., fiber cords or woven fabrics) are selected from the group consisting of acrylic fibers, polyamide fibers, polyester fibers, polyolefin fibers, cellulose fibers, glass fibers, ceramic fibers, phenolic (phenol-formaldehyde) fibers, carbon fibers, mineral fibers, metal fibers, composite fibers comprising at least one of the above materials, and combinations thereof.

[0082] In other embodiments of the invention, the fibers forming the fiber material comprise, consist essentially of, or consist of glass. In some such embodiments, the glass is further defined as E-glass fiber (alumino-borosilicate glass with less than 1% w / w alkali oxides), A-glass (soda-lime glass with little or no boron oxide), E-CR-glass (electrical resistance / chemical resistance; alumino-lime silicate with less than 1% w / w alkali oxides, with high acid resistance), C-glass (soda-lime glass with high boron oxide content, which is used for glass staple fibers and insulation), D-glass (borosilicate glass, named for its low dielectric constant), R-glass (alumino-silicate glass without MgO and CaO for high mechanical requirements as reinforcement), and S-glass (alumino-silicate glass without CaO but with high MgO content for high tensile strength).

[0083] In many embodiments, the fiber material comprises, consists essentially of, or consists of any polymer known in the art, and can be produced in any manner known in the art, such as wet spinning, hot extrusion, and the like.

[0084] In some embodiments, the polymer forming the fibers of the fibrous material is selected from polyamides, polyesters, polyolefins, thermoplastic polyurethanes (TPU), polyvinyl alcohols (e.g., PVOH, PVA, or PVAl), polyolefins (e.g., polyethylene (PE), ultra-high molecular weight PE (UHMWPE), polypropylene (PP)), and combinations thereof.

[0085] In many embodiments, the fiber material comprises, consists essentially of, or consists of polyamide fibers. Polyamide can be defined as a polymer comprising repeating amide (-CO-NH-) linkages. Polyamide can be a homopolymer (e.g., nylon 6) or a copolymer (e.g., nylon 6,6, nylon 6 / 66). As defined herein, a copolymer comprises two or more different monomers.

[0086] The polyamide can be an aliphatic polyamide, such as nylon, or an aromatic polyamide, such as aramid. In some embodiments, the polyamide is meta-aramid. In other embodiments, the polyamide is para-aramid. Aramid fibers are a class of synthetic fibers that are heat resistant and strong. In various embodiments, the term "consisting essentially of" describes the polyamide itself as only a single compound, two compounds, three compounds, etc., and may not contain any other polyamides or compounds.

[0087] Typically, the polyamide can be, include, consist essentially of, or consist of one or more nylons, aramids, proteins, metal poly(aspartates) such as sodium poly(aspartate), and combinations thereof.

[0088] In some embodiments, the polyamide is an aliphatic or semi-aromatic polyamide such as nylon. Nylon is a condensation copolymer typically formed by reacting a diamine with a dicarboxylic acid to form a peptide bond. In one embodiment, nylon is further defined as having less than about 85% of amide linkages (-CO-NH-) directly attached to two aliphatic groups. More specifically, the polyamide can be one or more of the following or include, consist essentially of, or consist of: polyamide 6, polyamide 6,6, polyamide 6 / 66, polyamide 10 / 10, polyamide 10 / 12, poly (4-aminobutyric acid) (nylon 4), poly (7-aminoheptanoic acid) (nylon 7), poly (8-aminooctanoic acid) (nylon 8), poly (9-aminononanoic acid) (nylon 9), poly (10-aminodecanoic acid) (nylon 10), poly (11-aminoundecanoic acid) (nylon 11), poly (12-aminododecanoic acid) (nylon 12), nylon 4,6, poly(hexamethylene sebacamide) (nylon 6,10), poly(heptamethylene pimelic acid amide) (nylon 7,7), poly(octamethylene suberic acid amide) (nylon 8,8), poly(hexamethylene azelaic acid amide) (nylon 6,9), poly(nonamethylene azelaic acid amide) (nylon 9,9), poly(decamethylene azelaic acid amide) (nylon 10,9), poly(tetramethylene diamine-co-oxalic acid) (nylon 4,2), polyamide of n-dodecane dioic acid and hexamethylene diamine (nylon 6,12), polyamide of n-dodecane dioic acid and dodecamethylene diamine amide (nylon 12,12), trimethylene adipamide / hexamethylene azelaic acid (azelaiamide) copolymer (trimethyl nylon 6,2 / 6,2), hexamethylene adipamide-hexamethylene azelaic acid caprolactam copolymer (nylon 6,6 / 6,9 / 6), poly (tetramethylene diamine-co-isophthalic acid) (nylon 4,I), polyhexamethylene isophthalamide (nylon 6,I), hexamethylene adipamide / hexamethylene isophthalamide (nylon 6,6 / 61), hexamethylene adipamide / hexamethylene terephthalamide (nylon In some embodiments, the polyamide is selected from the group consisting of polyamide 6, polyamide 6,6 / 6T), poly(2,2,2-trimethylhexamethylene terephthalamide), poly(m-xylylene adipamide) (MXD6), poly(p-xylylene adipamide), poly(hexamethylene terephthalamide), poly(dodecamethylene terephthalamide), polyamide 6T / 6I, polyamide 6 / MXDT / I, polyamide MXDI, a terpolymer of lauryl lactam, isophthalic acid and bis(4-amino-3-methylcyclohexyl)methane and polynorbornamide, and combinations thereof. Even more typically, the polyamide is selected from the group consisting of polyamide 6, polyamide 6,6, polyamide 6 / 66, and combinations thereof. In other embodiments, the polyamide is selected from the group consisting of polyamide 6, polyamide 6,6, polyamide 6 / 66, polyamide 12, polyamide 11, polyamide 6 / 10, polyamide 6 / 6.36, polyamide 6I / 6T, and combinations thereof.

[0089] In a preferred embodiment, the polyamide is an aromatic polyamide, i.e., aramid. Aramids are typically formed by reacting an amine with a carboxylic acid halide. In one embodiment, the aramid is further defined as having at least about 85% of amide linkages (-CO-NH-) directly attached to two aromatic rings. The aramid can be any aromatic polyamide known in the art, but is typically further defined as an AABB polymer, which is known by trade names such as and / or New Star TM Sales. As is well known in the art, and NewStar TM It comprises primarily meta linkages and is typically further defined as poly(meta-phenylene isophthalamide). and All are p-phenylene terephthalamide (PPTA), the simplest form of AABB para-polyaramid. PPTA is the product of p-phenylenediamine (PPD) and terephthaloyl chloride (TDC or TCl). Alternatively, aromatic polyamide can be further defined as the reaction product of PPD, 3,4'-diaminodiphenyl ether and terephthaloyl chloride (TCl). In a preferred embodiment, the polyamide is poly(p-phenylene terephthalamide).

[0090] In various embodiments, the polyamide has a weight average molecular weight of greater than about 10,000 g / mol, or greater than about 25,000 g / mol, or from about 10,000 to about 1,000,000 g / mol, or from about 50,000 to about 750,000 g / mol, or from about 25,000 to about 500,000 g / mol. In additional non-limiting embodiments, all values ​​and ranges of values ​​(both whole and partial) within one or more of the above ranges are expressly contemplated herein.

[0091] In another embodiment, the fiber material comprises, consists essentially of, or consists of polyester fibers. Polyester can be defined as a polymer comprising repeated ester functional groups (ester groups). In other words, several ester groups are linked within the polyester. Typically, an alcohol is chemically reacted with a carboxylic acid to form an ester. Alternatively, a polyester can be defined as a polymer comprising at least about 85% by weight of an ester, a glycol, or terephthalic acid. The polyester can be a homopolymer or a copolymer.

[0092] In some embodiments, polyester is an aliphatic polyester. Examples of suitable aliphatic polyesters include, but are not limited to, homopolymers, such as polyglycolide or polyglycolic acid (typically formed via polycondensation of glycolic acid), polylactic acid (typically formed via ring-opening polymerization of lactide), polycaprolactone (typically formed via ring-opening polymerization of caprolactone), polyhydroxyalkanoate, and polyhydroxybutyrate. Examples of suitable aliphatic polyesters include, but are not limited to, copolymers, such as polyethylene adipate, polybutylene succinate (typically formed via polycondensation of succinic acid and 1,4-butanediol) and poly (3-hydroxybutyrate-co-3-hydroxyvalerate (typically formed via copolymerization of 3-hydroxybutyric acid and 3-hydroxyvaleric acid, butyrolactone, valerolactone and oligomer aluminoxane as a catalyst) and polycyclohexanedimethanol terephthalate (typically formed via polycondensation of terephthalic acid and cyclohexanedimethanol).

[0093] In other embodiments, the polyester is an aromatic polyester such as vectran TM (Typically formed via the polycondensation of 4-hydroxybenzoic acid and 6-hydroxynaphthalene-2-carboxylic acid).

[0094] In a preferred embodiment, the polyester is a semi-aromatic polyester. Examples of suitable aliphatic polyesters include, but are not limited to, copolymers such as polyethylene terephthalate (typically formed via the polycondensation of terephthalic acid and ethylene glycol), polybutylene terephthalate (typically formed via the polycondensation of terephthalic acid and 1,4-butanediol), polytrimethylene terephthalate (typically formed via the polycondensation of terephthalic acid and 1,3-propylene glycol), and polyethylene naphthalate (typically formed via the polycondensation of at least one naphthalene dicarboxylic acid and ethylene glycol).

[0095] In some specific embodiments, the polyester can be selected from polyalkylene terephthalates, such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polyethylene adipate, polyhydroxyalkanoate, polyhydroxybutyrate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polyglycolide, polylactic acid, the polycondensation product of 4-hydroxybenzoic acid and 6-hydroxynaphthalene-2-carboxylic acid, and polycaprolactone. In a specific embodiment, the rubber is further defined as a semicrystalline thermoplastic polyester, including but not limited to polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene terephthalate-co-ethylene isophthalate, and combinations thereof. In a preferred embodiment, the rubber is polybutylene terephthalate. In another preferred embodiment, the rubber is polyethylene naphthalate.

[0096] In various embodiments, the polyester has a weight average molecular weight of greater than about 10,000 g / mol, or greater than about 25,000 g / mol, or from about 10,000 to about 1,000,000 g / mol, or from about 50,000 to about 750,000 g / mol, or from about 25,000 to about 500,000 g / mol. In additional non-limiting embodiments, all values ​​and ranges of values ​​(both whole and partial) within one or more of the above ranges are expressly contemplated herein.

[0097] In certain embodiments, fibrous material is further defined as comprising about 2 to about 8 or about 2 to about 4 warp yarns (end) or strands. As known in the art, "warp yarn" is a single strand comprising one or more filaments. In certain embodiments, fiber is loose continuous filament or staple fiber. In certain embodiments, the fiber forming fibrous material can be stretched or nonwoven. In other embodiments, fibrous material is woven or braided. Yarn can include the warp yarn (for example, only polyamide warp yarn) of a material or the warp yarn (for example, polyamide warp yarn and polyester warp yarn) of more than a material. For this reason, the fiber in fibrous material can be single warp yarn, multi-warp yarn or staple fiber yarn.

[0098] The fiber material may include fibers having cross-sectional profiles of various shapes, such as round, oval, triangular, rectangular, square, 5-sided, 6-sided, bell-shaped, star-shaped, bilobal, trilobal, flat, etc. In some embodiments, the fibers are hollow.

[0099] In many embodiments, the fibrous material comprises fibers having: a denier of about 250 to about 3,000, about 1,000 to about 2,500, or about 1,400 to about 2,100; and / or a diameter of about 0.1 to about 15 μm, about 0.3 to about 7.5 μm, or about 0.5 to about 3 μm. As defined herein, denier is the mass in grams per 9,000 meters of fiber. In additional non-limiting embodiments, all values ​​and ranges of values ​​(both whole and partial) within one or more of the above ranges are expressly contemplated herein.

[0100] More desirably, the fiber material is a woven fabric or fiber cord (preferably a woven fabric), preferably selected from any one of polyester, polyamide, nylon 6.6, nylon 6, polyethylene terephthalate, polyethylene naphthalate, rayon, aramid, cotton or wool.

[0101] As provided herein, the present invention further provides a method of producing a rubber composite material comprising rubber and a fiber material, wherein the fiber material has improved adhesion to the rubber, the method comprising the steps of:

[0102] providing an aqueous formulation comprising a hydrophobized polyethyleneimine;

[0103] contacting the fibrous material with the aqueous formulation to form a coated fibrous material;

[0104] drying the coated fiber material;

[0105] contacting the coated fiber material with the rubber and vulcanizing it to form the rubber composite,

[0106] Therein the hydrophobized polyethyleneimine has been hydrophobized to provide a substituent with one or more pendant reactive groups.

[0107] Therefore, after coating the fiber material and subjecting it to the drying stage as provided above, the fiber material of coating is then contacted with rubber. This can be achieved by applying multiple rubber layers, wherein the fiber material of coating is placed between each of these rubber layers. The number of rubber layers forming composite material is at least 2 and usually more, such as at least 3. Suitably, composite material can be formed by 2 to 10 rubber layers, and these rubber layers have 1 to 9 fiber material layers of coating placed between each of these rubber layers, such as formed by 3 to 8 rubber layers, and these rubber layers have 2 to 7 fiber material layers of coating placed between each of these rubber layers.

[0108] Once the rubber composite has been constructed, it is subjected to a heat treatment phase, typically a vulcanization phase. Typically, the heat treatment or vulcanization phase is carried out at a temperature of at least 120° C., for example even up to 200° C. or higher, and the heat treatment or vulcanization phase may typically last for a period of up to 30 minutes. It may be desirable to heat treat the vulcanization phase under high pressure (i.e., a pressure greater than one atmosphere). The exact pressure often depends on the specific industrial scale process employed.

[0109] It is believed that the heat treatment or vulcanization stage induces the pendant reactive groups in the hydrophobized polyethyleneimine to react and induce crosslinking, which enhances the adhesion of the fiber material to the rubber in the rubber composite.

[0110] The term rubber used throughout this specification means natural rubber or synthetic rubber, and includes polymers selected from elastomers, thermoplastics, thermoplastic elastomers, and combinations thereof.

[0111] Rubber can be a thermoplastic polymer or a thermosetting polymer. Thermoplastics have a relatively high molecular weight and molecular chains associated by intermolecular forces that weaken rapidly as the temperature rises, and therefore the thermoplastic melts. As such, thermoplastics can be reshaped by heating and are typically used to produce parts by various polymer processing techniques such as injection molding, compression molding, calendering, and extrusion. In contrast to thermoplastics, thermosetting plastics form irreversible chemical bonds when solidified, and therefore do not melt, but decompose.

[0112] In many embodiments, rubber is a thermoplastic polymer (thermoplastic). Thermoplastic can be an amorphous or crystalline polymer. Generally, when compared with an amorphous polymer, a crystalline polymer has a relatively clear melting point, has a more ordered molecular chain arrangement, and requires a higher temperature to flow well. Generally, an amorphous polymer does not have a real melting point and softens gradually, has a more random molecular chain orientation, and does not flow as easily as an amorphous polymer. In certain embodiments, a thermoplastic composition comprises a combination of a crystalline thermoplastic polymer and an amorphous thermoplastic polymer. In other embodiments, a thermoplastic composition comprises a thermoplastic elastomer, and these thermoplastic elastomers can include a crystalline segment and an amorphous segment.

[0113] Various non-limiting examples of suitable thermoplastics and thermoplastic elastomers include polyolefins (e.g., PP, PE, ethylene / hexane copolymers, ethylene / acrylic acid, etc.), polyolefin elastomers, polyvinyl chloride (PVC), polyamide (PA), styrene elastomers, thermoplastic vulcanizates (TPV), fluoropolymers (e.g., PTFE, perfluoroelastomers, etc.), silicones, polyesters, polyester elastomers, polyoxymethylene (POM), thermoplastic polyurethanes (TPU), and combinations thereof. In some preferred embodiments, the rubber is selected from thermoplastic polyurethanes, polyoxymethylenes, polyalkylene terephthalates, and combinations thereof.

[0114] In many preferred embodiments, the polymer is an elastomer (rubber). Various non-limiting examples of suitable elastomers include natural rubber (natural polyisoprene), synthetic polyisoprene, polybutadiene, chloroprene rubber, butyl rubber, halogenated butyl rubber, styrene-butadiene rubber, nitrile rubber, ethylene propylene rubber, ethylene propylene diene rubber (EPDM), epichlorohydrin rubber, polyacrylic rubber, silicone rubber, fluorosilicone rubber, fluoroelastomer, perfluoroelastomer, polyether block amide, chlorosulfonated polyethylene, and ethylene-vinyl acetate.

[0115] In many embodiments, the rubber is included in the rubber composite in an amount of about 5% to about 95%, about 20% to about 90%, about 30% to about 80%, or about 40% to about 70% by weight based on the total weight of the rubber composite. Further, it should be understood that more than one type of polymer (e.g., two different polymers) can be included in the rubber composite, in which case the total amount of all polymers present in the rubber composite is within the above range. In other non-limiting embodiments, all values ​​and value ranges (both whole and partial) within one or more of the above ranges are expressly contemplated herein.

[0116] Various additives may be included in the rubber composite. Suitable additives include, but are not limited to, processing additives, plasticizers, chain terminators, surfactants, adhesion promoters, flame retardants, antioxidants, water scavengers, dyes, ultraviolet light stabilizers, fillers, acidulants, thixotropic agents, curing agents / crosslinking agents, catalysts, foaming agents, surfactants, and combinations thereof. Additives may be included in any amount as desired by one skilled in the art.

[0117] Preferably, the rubber used in the rubber composite material is selected from any one of ethylene propylene diene monomer rubber (EPDM), EE, natural rubber (NR), hydrogenated nitrile rubber (HNBR), styrene butadiene rubber (SBR), butyl rubber (IIR), nitrile rubber (NBR), chloroprene rubber (CR), silicone rubber (Q), fluoroelastomer rubber (FKM) or polyurethane rubber (AU).

[0118] The following examples are intended to illustrate the present invention and should not be construed in any way as limiting the scope of the present invention.

[0119] Examples

[0120] Example 1 - Synthesis of Hydrophobic Polyethyleneimine

[0121] BASF will Hyperbranched polyethyleneimine (PEI) (weight average molecular weight 800 g / mol) commercially sold by FG ​​(supplied as an anhydrous product) was hydrophobized by reaction with allyl glycidyl ether (AGE) via the modification procedure disclosed in: Acebo, C. et al., Reactive and Functional Polymers, 2016, 99: pp. 17-25.

[0122] Under nitrogen FG was heated to 50° C. in a reaction flask. Three weight equivalents of allyl glycidyl ether were then added dropwise to the reaction vessel over 5.5 hours, and the exothermic reaction was continued for another 8 hours. The final product was identified as H-PEI Sample A. The progress of the reaction was determined by TLC (thin layer chromatography), and the 1 H-NMR confirmed the final structure. 1 The H-NMR spectrum is shown in Figure 1 middle.

[0123] This synthesis was repeated with a PEI to AGE ratio of 1:1 and 1:0.5. In both cases, the reaction temperature was 50°C. The resulting products were identified as H-PEI sample B and H-PEI sample C, respectively. The synthesis details of these three H-PEI samples are given in Table 1. 1 The H-NMR spectrum is shown in Figure 2 middle.

[0124] Table 1

[0125] H-PEI Sample Weight Ratio equivalent Total reaction time A 1:3 0.937 13.5 hours B 1:1 0.312 6 hours C 1:0.5 0.167 6 hours

[0126] Example 2 - Formulation of an adhesive emulsion (aqueous formulation)

[0127] By adding 0.1g XP90 (C10 Guerbet alcohol ethoxylate (POE9) commercially available from BASF), 3 parts of hydrophobized polyethyleneimine (H-PEI sample A) and 33.9 g VP 106 (commercially available vinyl pyridine, styrene, butadiene polymer latex from Omnova Solutions) was dispersed in 63 g of deionized water to prepare an adhesive formulation. The dispersion was stirred until it was uniform, and then aged overnight. It was identified as formulation sample 1. Hydrophobized polyethyleneimine H-PEI sample B and H-PEI sample C were used to prepare formulations similar to sample 1, and these were identified as formulation samples 2 and 3, respectively. The preparation of formulation 1 was repeated by using polyethyleneimine ( A comparative formulation was prepared by replacing H-PEI Sample A with FG) and was identified as Formulation Sample 4. 0.1 g XP90, 33.9g VP 106 and 66 g of deionized water (ie without any hydrophobized polyethyleneimine or polyethyleneimine) to prepare a control formulation sample. This is summarized in Table 2.

[0128] Table 2

[0129]

[0130] Example 3 - Dip coating of woven fabrics and composite material formation and testing

[0131] Each formulation sample listed in Table 2 was evaluated by dip coating onto woven fabrics and producing the rubber composites tested. In addition, as a further comparison, a standard RFL formulation (latex and resorcinol formaldehyde) was similarly tested.

[0132] By being immersed in adhesive emulsion (water-based formulation) for 30 minutes, dip coating is carried out on polyester fabric (6 inches × 6 inches).The fabric processed is wrung out by hand and dried in an oven.Five layers of composite materials are prepared by alternating three layers of rubber with two layers of processed fabric and then heating (150 ℃) under pressure for 20 minutes.The rubber composite is cooled for at least 24 hours, then cut into 1 inch strips to analyze via ASTM D413 (titled "Standard Test Methods for Rubber Property-Adhesion to Flexible Substrate [Standard Test Methods for Rubber Property-Adhesion to Flexible Substrate] ", ASTM International (ASTM International Association) (http: / / www.astm.org / d0413-98r17.html)).Peel strength is measured under the result shown in Table 3.

[0133] Table 3

[0134]

[0135]

[0136] The results show that the rubber composite prepared with the hydrophobized polyethyleneimine (1:3) formulation Sample 1 adhesive system of the present invention has an average peel strength of 54.8N; a result that is about 85% of the proprietary RFL system. Similar average peel strengths were observed from the hydrophobized polyethyleneimine (1:1) and (1:0.5) formulations Samples 2 and 3, respectively. This system also demonstrates the excellent adhesion of the present invention system compared to the latex adhesive system (control) and the latex polyethyleneimine system (Sample 4).

[0137] Example 4 - Co-formulation of hydrophobized PEI and adhesion improvers

[0138] An adhesive emulsion (aqueous formulation) was prepared analogously to Example 2 containing an additional adhesion improver selected from one of the following two compounds: (trimethylsiloxypropyl glycidyl ether) (CAS No. 2530-83-8); and trimethylolpropane triglycidyl ether (TMPTE) (CAS No. 30499-70-8). The composition of each of these aqueous formulations is given in Table 4.

[0139] Table 4

[0140]

[0141] Adhesive Formulations 5-9 were each coated onto a woven fabric used to construct a rubber composite and tested for adhesion strength as described in Example 3. The results are presented below in Table 5. The results for Formulations 5, 6, 7, and 9 are also presented in FIG3 .

[0142] Table 5

[0143]

[0144]

[0145] The results show that adhesive formulations containing hydrophobized polyethyleneimine and additional adhesion improvers generally provide more effective results. The best results were provided by formulations 8 and 9 of the present invention, which showed average peel strengths of 84.6N and 107.48N, respectively. Formulation 7 of the present invention showed an average peel strength of 61.49, only slightly lower than the RFL proprietary formulation. Although the average peel strength of formulation 7 of the present invention is lower than that of comparative formulation 6 corresponding to a formulation with unmodified polyethyleneimine, comparative formulation 6 shows a standard deviation of 14.1, which is significantly greater than the standard deviation of formulation 7 of the present invention (standard deviation of 4.25), which indicates that the performance of comparative formulation 6 is more variable compared to the formulation of the present invention.

[0146] Example 5 - Aqueous Synthesis of Hydrophobized Polyethyleneimine

[0147] Will FG (99%, free of water) (30 g) was placed in a flask and 24.5 g of water was added. The solution was exothermic, raising the temperature to 45° C. The reaction mixture was heated to 55° C. Allyl glycidyl ether (33.5 g) was added over 100 minutes, causing an exotherm to 70° C. The reaction mixture was stirred at 60° C. for another 4 hours and 40 minutes to complete the reaction.

[0148] Example 6 - Aqueous Synthesis of Hydrophobized Polyethyleneimine

[0149] Will G20 (MW 1300Da) (50% aqueous solution) (62.3g) was placed in a flask and heated to 50°C. Allyl glycidyl ether (34.7g) was added over 40 minutes, resulting in an exothermic reaction temperature up to 65°C. The reaction mixture was stirred at 60°C for another 3.5 hours to complete the reaction.

Claims

1. Use of a hydrophobized polyethyleneimine for improving the adhesion of fiber materials to rubber in rubber composites, wherein the hydrophobized polyethyleneimine has been hydrophobized to provide substituents with one or more pendant reactive groups.

2. The use according to claim 1, wherein The one or more pendant reactive groups are silane groups or ethylenically unsaturated groups, preferably selected from any one of allyl groups, propargyl groups, acrylic groups or methacrylic groups.

3. The use according to claim 1 or claim 2, wherein The hydrophobized polyethyleneimine has been hydrophobized by a modifying agent, by a modifying agent having an amine-reactive group, which reacts with the polyethyleneimine, the amine-reactive group preferably being selected from any one of epoxides, isocyanate groups, blocked isocyanate groups or anhydrides.

4. The use according to claim 3, wherein The modifier is glycidyl allyl ether.

5. The use according to any preceding claim, wherein The hydrophobized polyethyleneimine comprises a structure represented by formula (I): in R1 represents the first fragment of the polyethyleneimine; R2 represents the second fragment of the polyethyleneimine, or represents hydrogen or A; and A is a hydrophobic group derived from a hydrophobizing agent represented by formula (II): XYZ II wherein X represents an amine-reactive group containing 1 to 6 carbon atoms with an epoxide or isocyanate group; Y represents a divalent organic group containing 1 to 8 carbon atoms; and Z represents one or more pendant reactive groups selected from any one of an allyl group, a propargyl group, an acrylic group, a methacrylic group or a silane group.

6. The use according to claim 5, wherein X represents a glycidyl ether, Y represents a divalent organic group containing 2 or 3 carbon atoms, and Z represents an allyl group or a silane group.

7. Use according to any preceding claim, wherein The hydrophobized polyethyleneimine has a degree of functionalization of 0.2 to 1.

55.

8. Use according to any preceding claim, wherein The hydrophobized polyethyleneimine is derived from branched polyethyleneimine.

9. The use according to any preceding claim, wherein The hydrophobized polyethyleneimine is derived from polyethyleneimine having a weight average molecular weight (Mw) of 500 to 10,000 g / mol.

10. The use according to any preceding claim, wherein The hydrophobized polyethyleneimine is derived from a branched polyethyleneimine having a 13 The degree of branching was determined by C-NMR and was between 0.3 and 0.

85.

11. The use according to any preceding claim, wherein The hydrophobized polyethyleneimine is derived from a branched polyethyleneimine comprising, based on 100% of all groups present in the branched polyethyleneimine, 13 30% to 45% linear groups, 20% to 30% dendritic groups and 30% to 45% terminal groups as determined by C-NMR.

12. The use according to any preceding claim, wherein The hydrophobized polyethyleneimine is formulated into an aqueous formulation comprising latex which is contacted with the fiber material, wherein preferably the aqueous formulation is a dipping solution.

13. The use according to claim 12, wherein The latex comprises a vinylpyridine polymer.

14. The use according to claim 12 or claim 13, wherein An adhesion improver is formulated into the aqueous formulation, preferably into the dipping solution, wherein the adhesion improver is capable of reacting with the amine.

15. The use according to claim 14, wherein The adhesion improver is selected from any one of epoxides, isocyanates, blocked isocyanates, anhydrides, acrylates, methacrylates or silanes.

16. The use according to claim 15, wherein The silane is a siloxyalkyl glycidyl ether, preferably a trialkylsiloxyalkyl glycidyl ether, more preferably trimethylsiloxypropyl glycidyl ether.

17. The use according to any one of claims 14 to 16, wherein The concentration of the hydrophobized polyethyleneimine in the aqueous formulation is from 2 to 27% by weight of the aqueous formulation, preferably wherein the aqueous formulation is the impregnation solution.

18. The use according to any one of claims 14 to 17, wherein The hydrophobized polyethyleneimine in the aqueous formulation is 10 to 40% by weight of the solids content of the aqueous formulation, preferably wherein the aqueous formulation is the impregnation solution.

19. Use according to any preceding claim, wherein The rubber is selected from any one of ethylene propylene diene monomer rubber (EPDM), EE, natural rubber (NR), hydrogenated nitrile rubber (HNBR), styrene butadiene rubber (SBR), butyl rubber (IIR), nitrile rubber (NBR), chloroprene rubber (CR), silicone rubber (Q), fluoroelastomer rubber (FKM) or polyurethane rubber (AU).

20. The use according to any preceding claim, wherein The fiber material is a woven fabric, preferably selected from any one of polyester, polyamide, nylon 6.6, nylon 6, polyethylene terephthalate, polyethylene naphthalate, rayon, aramid, cotton or wool.

21. A method for improving the adhesion of a fiber material to rubber in a rubber composite material, the method comprising the steps of: providing an aqueous formulation comprising a hydrophobized polyethyleneimine; contacting the fibrous material with the aqueous formulation to form a coated fibrous material; as well as drying the coated fiber material, Therein the hydrophobized polyethyleneimine has been hydrophobized to provide a substituent with one or more pendant reactive groups.

22. The method according to claim 21, wherein: The method comprises any of the features of any of claims 2 to 20.

23. A method of producing a rubber composite material comprising rubber and a fiber material, wherein the fiber material has improved adhesion to the rubber, the method comprising the steps of: providing an aqueous formulation comprising a hydrophobized polyethyleneimine; contacting the fibrous material with the aqueous formulation to form a coated fibrous material; drying the coated fiber material; contacting the coated fiber material with the rubber and vulcanizing it to form the rubber composite, Therein the hydrophobized polyethyleneimine has been hydrophobized to provide a substituent with one or more pendant reactive groups.

24. The method according to claim 23, wherein: The method comprises any of the features of any of claims 2 to 20.

25. A coated fiber material comprising a coating comprising a hydrophobized polyethyleneimine, wherein the hydrophobized polyethyleneimine has been hydrophobized to provide substituents with one or more pendant reactive groups, the coated fiber material having improved adhesion to rubber in a rubber composite obtainable by a process according to claim 21 or claim 22.

26. A rubber composite material obtainable by a process according to claim 23 or claim 24, comprising rubber and a fibre material, wherein the fibre material comprises a coating of a hydrophobised polyethyleneimine, wherein the hydrophobised polyethyleneimine has been hydrophobised to provide substituents with one or more pendant reactive groups, the fibre material having improved adhesion to the rubber in the rubber composite.

27. An aqueous formulation suitable as a dipping solution for resorcinol formaldehyde latex (RFL)-free for improving the adhesion of fiber materials to rubber in rubber composites, wherein the aqueous formulation comprises: A) a hydrophobized polyethyleneimine which has been hydrophobized to provide a substituent with one or more pendant reactive groups; and B) Latex.

28. The aqueous formulation according to claim 27, wherein The hydrophobized polyethyleneimine comprises any one of the features of any one of claims 2 to 11.

29. An aqueous formulation according to claim 27 or claim 28, wherein The latex comprises a vinyl pyridine polymer.

30. An aqueous formulation according to any one of claims 27 to 29, wherein The aqueous formulation further comprises C) an adhesion improver which is capable of reacting with amines.

31. The aqueous formulation according to claim 30, wherein The adhesion improver comprises any one of the features of claims 14 to 16 .

32. An aqueous formulation according to any one of claims 27 to 31, wherein The aqueous formulation comprises any of the features of claim 17 or claim 18.

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