Composition for fiber surface treatment and fiber treatment method

Abstract

An adhesive composition for fiber surface treatment and a fiber treatment method. The adhesive composition for fiber surface treatment comprises the following components or consists of the following components: solvent: 100 parts; polyurethane dispersion resin: 1-15 parts; epoxy resin: 0.1-5 parts; blocked isocyanate: 1-10 parts; curing agent: 0.05-2 parts; rubber latex: 50-150 parts; and filler: 0-30 parts. According to the method, the use of toxic raw materials and intermediates in a traditional RFL impregnation system can be effectively replaced, the harm to human bodies and environments is reduced, and the bonding effect of RFL can be achieved.

Description

Composition for fiber surface treatment and fiber treatment method Technical Field

[0001] The present invention relates to the field of fiber dipping technology, and more specifically, to an environmentally friendly adhesive composition for fiber surface treatment and a method for treating fibers using the composition. More specifically, the present invention relates to an adhesive composition having excellent bonding strength even without the presence of resorcinol and formaldehyde, and a method for treating fibers using the adhesive composition. Background Art

[0002] Fiber / rubber composites are widely used in load-bearing and pressure-resistant rubber products such as tires, conveyor belts, and hoses. The rubber matrix has high elasticity and can produce large deformations when the composite is subjected to stress, while the fiber skeleton material can resist the damage to the composite caused by stress due to its high strength and stiffness. For fiber / rubber composites, the interfacial adhesion between the fiber and the rubber matrix determines the stress transfer efficiency of the composite, and thus determines the performance and life of the composite. Currently, the fibers commonly used to prepare skeleton materials include nylon fibers, aramid fibers, polyester fibers, polyimide fibers, carbon fibers, etc. However, due to factors such as the high crystallinity, chemical inertness, and large difference in modulus between the fiber and the rubber matrix, the interfacial interaction between the fiber and the rubber is weak.

[0003] Currently, the resorcinol-formaldehyde-latex (RFL) impregnation system is the most commonly used industrial method for improving fiber-rubber adhesion. The mechanism of the RFL impregnation system is that the resorcinol-formaldehyde resin phase interacts with polar groups on the fiber surface through hydroxyl groups. Simultaneously, the rubber latex phase can crosslink with the rubber matrix through a co-vulcanization process, thereby enhancing the adhesion between the fiber and rubber. However, resorcinol and formaldehyde pose significant risks to human health and the environment. The resorcinol and formaldehyde used in this method have been classified as carcinogens by the International Agency for Research on Cancer (IARC), and an increasing number of countries are banning their use in tire production. Therefore, there is an urgent need to develop new, environmentally friendly fiber impregnation treatment systems to replace traditional RFL treatment methods.

[0004] Currently, several documents have disclosed various non-RFL impregnation systems. For example, US20120041113 discloses a dipping solution composed of an epoxy resin, a blocked isocyanate, an amino curing agent, and latex for treating polyester and nylon fibers in a single bath. US5565507A discloses a dipping solution composed of an epoxy resin with trifunctionality or higher and a latex containing carboxyl, pyridine, or amino groups, for enhancing the adhesion between fiber fabrics and rubber. US20150259560 discloses a dipping solution composed of an acrylic resin, an epoxy compound, an isocyanate, and a rubber latex, for improving the adhesion between fibers and cords and rubber. US20200010741A1 discloses a dipping solution composed of an isocyanate compound, an epoxy compound, an aqueous polyurethane dispersion resin, and a rubber latex, for improving the adhesion between polyester fibers and rubber. However, there are currently no commercially available non-RFL impregnation products suitable for a wide range of fibers.

[0005] Summary of the Invention

[0006] The present invention aims to provide an environmentally friendly adhesive composition for treating fiber surfaces and a method for treating fibers using the composition.

[0007] In a first aspect, the present invention provides an adhesive composition for fiber surface treatment, which has excellent adhesive strength and does not contain resorcinol-formaldehyde.

[0008] Another aspect of the present invention is to provide a method for surface treating fibers using the above-mentioned resorcinol-formaldehyde-free binder composition.

[0009] The adhesive composition for fiber surface treatment provided by the present invention comprises or consists of the following components in parts by weight:

[0010] Preferably, the composition comprises or consists of the following ingredients in parts by weight:

[0011] The above composition may be stored as a single component dipping gel, for example in a single container.

[0012] In addition, the above composition can also be divided into two components (i.e., a first dipping glue and a second dipping glue), for example, stored in two separate containers. In this case, the composition is a two-component dipping glue. Therefore, in one embodiment, the composition includes:

[0013] A) a first dipping solution, the first dipping solution comprising or consisting of the following components: 0.1-5 parts of a first epoxy resin, preferably 1.2-1.8 parts; 1-15 parts of a blocked isocyanate, preferably 3-4.5 parts; 100 parts of a first solvent;

[0014] as well as

[0015] B) a second dipping solution, the second dipping solution comprising or consisting of the following components: 3-16 parts of polyurethane dispersion resin; preferably 3.3-4.1 parts; a second epoxy resin; preferably 0.5-5 parts; a curing agent; preferably 1.5-2.0 parts; a curing agent; 0.1-3 parts; preferably 0.4-2.1 parts; a rubber latex; preferably 20-50 parts; preferably 26-27.5 parts; a second solvent; 100 parts; a filler; preferably 0.4-2.7 parts;

[0016] The first dipping solution and the second dipping solution are stored in two separate containers.

[0017] According to the present invention, the polyurethane dispersion resin includes at least one of polycarbonate-based urethane, polyester-based urethane, polyacrylic urethane, polyurea polyurethane, 1,5-naphthalene diisocyanate (NDI) type polyurethane, para-phenylene diisocyanate (PPDI) type polyurethane, dimethyl diphenyl diisocyanate (TODI) type polyurethane, and toluene diisocyanate (TDI) type polyurethane; preferably, it is an aliphatic polyurethane dispersion resin and / or a polycarbonate polyurethane dispersion resin.

[0018] According to the present invention, the epoxy resin includes at least one of a glycidyl ether type compound, a phenolic epoxy resin and a bisphenol type epoxy resin, and can be a pure substance or an aqueous emulsion thereof; preferably, it is selected from one or more of bisphenol A epoxy resin, epoxidized linear phenolic resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,2-propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, diglycidyl ether, glycerol glycidyl ether, trimethylolpropane glycidyl ether, tetraphenol ethane tetraglycidyl ether epoxy resin, resorcinol bisglycidyl ether type epoxy resin, sorbitol glycidyl ether and bisresorcinol formal tetraglycidyl ether; more preferably, it is glycerol glycidyl ether and / or sorbitol glycidyl ether.

[0019] In a specific embodiment in which the first dipping solution and the second dipping solution are stored in two separate containers, respectively, the first epoxy resin and the second epoxy resin are the same or different, and are independently selected from at least one of glycidyl ether type compounds, phenolic epoxy resins and bisphenol epoxy resins; preferably selected from one or more of bisphenol A epoxy resin, epoxidized linear phenolic resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,2-propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, diglycidyl ether, glycerol glycidyl ether, trimethylolpropane glycidyl ether, tetraphenolyl ethane tetraglycidyl ether epoxy resin, resorcinol diglycidyl ether type epoxy resin, sorbitol glycidyl ether and bisresorcinol formal tetraglycidyl ether; more preferably, the first epoxy resin is sorbitol glycidyl ether; the second epoxy resin is glycerol glycidyl ether.

[0020] According to the present invention, the curing agent includes an imidazole curing agent and / or an amine curing agent; preferably, the imidazole curing agent is selected from one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole and 1-cyanoethyl-2-undecylimidazole; more preferably, 2-ethyl-4-methylimidazole;

[0021] Preferably, the amine curing agent is selected from one or more of hyperbranched polyamide, hyperbranched polyethyleneimine, supramolecular polyoxyethyleneamine, polyoxyethylenediamine, polyamide, dicyandiamide, piperazine, m-xylenediamine and m-phenylenediamine; more preferably, piperazine and / or m-phenylenediamine.

[0022] According to the present invention, the blocked isocyanate is a blocked isocyanate formed by an isocyanate and a blocking agent, preferably the isocyanate is selected from one or more of trimethyl-1,6-hexamethylene diisocyanate, tetramethylene diisocyanate, tetramethyl diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, isophorone diisocyanate and diphenylmethane diisocyanate, more preferably diphenylmethane diisocyanate;

[0023] The end-capping agent is selected from one or more of ε-caprolactam, butanone oxime and phenol; more preferably ε-caprolactam.

[0024] According to the present invention, the solvent is an aqueous solvent, preferably water, more preferably deionized water.

[0025] In a specific embodiment in which the first dipping solution and the second dipping solution are stored in two separate containers, the first solvent and the second solvent are the same or different and are each independently an aqueous solvent, preferably water, more preferably deionized water.

[0026] According to the present invention, the filler is selected from one or more of nano-silicon dioxide, carbon black, nano-titanium dioxide, nano-zinc oxide, nano-iron oxide, nano-calcium oxide, nano-calcium carbonate, carbon nanotubes, attapulgite, nano-cellulose, halloysite, nano-aramid fiber, basalt fiber, nano-whiskers, graphene oxide, montmorillonite, mica, kaolin and hydrotalcite; more preferably, attapulgite.

[0027] According to the present invention, the filler is a filler treated with a filler surface modifier; preferably, the filler surface modifier is selected from one or more of aminosilane coupling agents, epoxysilane coupling agents, alkylsilane coupling agents, isocyanatesilane coupling agents, and polyethersilane coupling agents; preferably, at least one selected from γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, bis-[γ-(triethoxysilyl)propyl]tetrasulfide and vinyltriethoxysilane; further preferably, γ-aminopropyltriethoxysilane.

[0028] According to the present invention, the rubber latex is selected from at least one of butyl pyrrolidone latex, styrene butadiene latex, styrene butadiene pyrrolidone latex, chloroprene latex, acrylonitrile butadiene rubber latex, chlorosulfonated polyethylene latex, epoxidized natural rubber latex, natural rubber latex, and acrylate latex; preferably, the rubber latex is at least one of butyl pyrrolidone latex, styrene butadiene latex, and natural rubber latex; and the solid content of the rubber latex is 20 to 60 wt %. According to the present invention, the rubber latex can be modified or unmodified rubber latex. Examples of modified rubber latex can include, but are not limited to, chlorinated, cyclized, epoxidized, and carboxylated modified latexes of the aforementioned rubber latex.

[0029] In a second aspect, the present invention further provides a method for treating a fiber surface, comprising:

[0030] Step 1) placing the fiber in a dipping solution for dipping, wherein the dipping solution is prepared from the composition according to the first aspect of the present invention;

[0031] Step 2) drying and curing the impregnated fibers obtained in step 1).

[0032] According to some specific embodiments of the present invention, the dipping solution in step 1) comprises: polyurethane dispersion resin, epoxy resin, blocked isocyanate, curing agent, rubber latex, solvent and optional filler.

[0033] According to some specific embodiments of the present invention, the dipping solution in step 1) comprises:

[0034] Preferably, the dipping solution in step 1) comprises or consists of the following components in parts by weight:

[0035] According to some embodiments of the present invention, the immersion is performed at a temperature of 10-40° C. and for a time of 2-60 s.

[0036] According to some embodiments of the present invention, the drying is performed at a temperature of 100 to 170° C. for 30 to 600 seconds; and the curing is performed at a temperature of 180 to 260° C. for 30 to 600 seconds.

[0037] According to some embodiments of the present invention, in step 1), the pH of the dipping solution is adjusted to alkaline, for example, to a pH of 8.0-12.0, before dipping. In some embodiments, the pH of the dipping solution is adjusted to greater than 7.5, preferably to 8.0-12.0, by using an alkaline solution such as sodium hydroxide solution or ammonia solution.

[0038] In a third aspect, the present invention further provides a method for treating a fiber surface, comprising the following steps:

[0039] Step A) placing the fiber in a first dipping solution for dipping, wherein the first dipping solution comprises or consists of the following components: 0.1-5 parts of a first epoxy resin; 1-15 parts of a blocked isocyanate; 100 parts of a first solvent;

[0040] Step B) drying the fibers treated in step A) and then curing them;

[0041] Step C) dipping the fiber treated in step B) into a second dipping solution, wherein the second dipping solution comprises or consists of the following components: 3-16 parts of a polyurethane dispersion resin; 0.5-5 parts of a second epoxy resin; 0.1-2 parts of a curing agent; 20-50 parts of a rubber latex; 100 parts of a second solvent; and 0-20 parts of a filler.

[0042] Step D) drying and curing the fibers treated in step C).

[0043] Preferably, the first dipping solution comprises or consists of the following ingredients: 1.2-1.8 parts of a first epoxy resin 3-4.5 parts of a blocked isocyanate 100 parts of a first solvent;

[0044] as well as

[0045] B) a second dipping solution, comprising or consisting of the following components: 3.3-4.1 parts of polyurethane dispersion resin; 1.5-2.0 parts of second epoxy resin; 0.4-2.1 parts of curing agent; 26-27.5 parts of rubber latex; 100 parts of second solvent; and 0.4-2.7 parts of filler.

[0046] According to some embodiments of the present invention, in step A), the immersion is carried out at a temperature of 10-40° C. and for a time of 2-60 s.

[0047] According to some embodiments of the present invention, in step B), the drying is performed at a temperature of 100-170° C. for a time of 30 to 600 seconds.

[0048] According to some embodiments of the present invention, in step B), the curing is performed at a temperature of 180-260° C. for a time of 30 to 600 seconds.

[0049] According to some embodiments of the present invention, in step C), the immersion is carried out at a temperature of 10-40° C. and for a time of 2-60 seconds.

[0050] According to some embodiments of the present invention, in step D), the drying is performed at a temperature of 100-170° C. for a time of 30 to 600 seconds.

[0051] According to some embodiments of the present invention, in step D), the curing is performed at a temperature of 180-260° C. for a time of 130 to 600 seconds.

[0052] According to some embodiments of the present invention, the pH of the second dipping solution is adjusted to alkaline before use, preferably to 8.0-11.0; more preferably, the pH is adjusted to 11.0-12.0.

[0053] According to the treatment method of the present invention, the types and amounts of the polyurethane dispersion resin, blocked isocyanate, curing agent, rubber latex, solvent and filler are the same as those described above and will not be repeated here.

[0054] According to some embodiments of the present invention, the fiber is rayon, nylon 6, nylon 66, meta- or para-aramid fiber, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, carbon fiber, or a mixed twisted cord of the above fibers.

[0055] According to some embodiments of the present invention, the fiber is in a form selected from monofilament, tow yarn, twisted cord, canvas, cord fabric, or a combination thereof.

[0056] The present invention proposes a novel adhesive composition for fiber surface treatment. Depending on the fiber type and intended use, either a single-bath immersion treatment (such as the treatment method described in the second aspect of the present invention) or a double-bath immersion treatment (such as the treatment method described in the third aspect of the present invention) can be used. Water-soluble nanofillers can be added or not. Surface modification of the nanofillers is also optional. This method exhibits excellent fiber bonding, making it a viable alternative to traditional RFL systems.

[0057] The adhesive composition of the present invention does not contain toxic and hazardous components such as resorcinol and formaldehyde, and thus poses no risk to humans or the environment. Fibers treated with the present invention exhibit excellent bonding properties and can replace traditional RFL systems. Furthermore, the adhesive composition does not compromise the strength of the fibers, nor does it affect their usability.

[0058] Fillers are added to the adhesive composition of the present invention, thereby further improving the bonding effect between the fiber and the rubber.

[0059] Advantages and features of the present invention:

[0060] 1. The adhesive composition for fiber surface treatment of the present invention is green and environmentally friendly, harmless to the human body and the environment, has low raw material prices, greatly improves bonding performance, and can replace the traditional RFL system.

[0061] 2. The polyurethane dispersion resin and epoxy resin added in the present invention are both water-soluble, and the added filler has good dispersibility after modification. The components of the dipping solution are relatively stable, and the viscosity will not increase significantly when placed for a long time at room temperature, which is conducive to the long-term storage and transportation of the glue solution.

[0062] 3. In the present invention, the preparation process of the dipping solution and the fiber treatment process are simple, which is conducive to industrial production.

[0063] 4. The cord fabric treated by the present invention is light yellow. The addition of different fillers will affect the color, which makes it possible to produce cord fabrics of different colors as required. DETAILED DESCRIPTION

[0064] The materials used in the following examples and comparative examples were synthesized or commercially available, wherein:

[0065] Aliphatic polyurethane dispersion resin, brand 1537, purchased from Shanghai Yuanhe Chemical Co., Ltd.

[0066] Polycarbonate polyurethane dispersion resin, brand Purchased from Shanghai Yuanhe Chemical Co., Ltd.

[0067] Glycerol glycidyl ether: CAS 13236-02-7, purchased from Beijing Hanlongda Technology Development Co., Ltd.

[0068] Sorbitol glycidyl ether: CAS 68412-01-1, purchased from Nan Ya Epoxy Resin Co., Ltd.

[0069] ε-Caprolactam-terminated diphenylmethane diisocyanate: CAS 5101-68-8, brand CBI 50, purchased from Changzhou Keying Chemical Co., Ltd.

[0070] Metaphenylenediamine, CAS 108-45-2, was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. with a purity of ≥99 wt%.

[0071] Styrene-butadiene-vinyl pyridine latex (VP latex): brand VP-15, purchased from Jiangsu Yatai Chemical Co., Ltd., solid content 40 wt%.

[0072] Filler: Attapulgite, purified 601 type, purchased from Jiangsu Shengyi Nanotechnology Co., Ltd.

[0073] Resorcinol: CAS 108-46-3, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., purity ≥99 wt%.

[0074] Formaldehyde: CAS 50-00-0, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., purity 37 wt%.

[0075] The preparation method of the H extraction force test strips in the following examples and comparative examples is as follows:

[0076] With reference to the standard GB / T2942-2009, the standard rubber (the standard rubber formula for nylon fiber refers to GBT9101-2017, the standard rubber formula for polyester fiber refers to GBT19390-2014, and the rubber formula for aramid fiber refers to polyester standard rubber) is completely covered on the dipped cord to prepare a withdrawal pattern. Finally, it is placed on a flat vulcanizer for vulcanization at a vulcanization temperature of 136°C, a vulcanization pressure of 15 MPa, and a vulcanization time of 50 min.

[0077] The preparation method of the peeling force test strip is as follows:

[0078] Referring to the standard GB / T40725-2021, the standard rubber is completely covered on the dipped cord to prepare a peeling specimen, which is finally placed on a flat vulcanizer for vulcanization. The vulcanization temperature is 160°C, the vulcanization pressure is 2.354MPa, and the vulcanization time is 20min.

[0079] The preparation method of the cord breaking strength test specimen is as follows:

[0080] With reference to the standard GB / T32108-2015, the dipped cord was clamped in a tensile testing machine for testing at a tensile speed of 300±5mm / min.

[0081] In the following examples and comparative examples, the cord breaking strength test is conducted in accordance with GB / T32108-2015; the H pull-out force is conducted in accordance with GB / T2942-2009; and the peeling force is conducted in accordance with GB / T40725-2021.

[0082] Example 1

[0083] An environmentally friendly adhesive composition for fiber surface treatment, the single-bath method formula ratio is as follows by weight:

[0084] The dipping solution was prepared by dissolving all components (except latex) in deionized water at a predetermined weight ratio. The solution was stirred vigorously at 500 rpm with an electric stirrer at 25°C for 1.5 hours. This solution was then added to styrene-butadiene-vinylpyridine latex, and the apparatus was kept at 25°C with vigorous stirring for 2 hours. During the stirring process, the pH of the dipping solution was adjusted to 11.0-12.0 by adding aqueous ammonia solution.

[0085] Dipping method:

[0086] The fiber cord was immersed in the impregnation liquid for 3 seconds, and then dried and cured in an oven at a drying temperature of 140°C for 40 seconds and a curing temperature of 210°C for 40 seconds.

[0087] Example 2

[0088] An environmentally friendly adhesive composition for fiber surface treatment, the single-bath method formula ratio is as follows by weight:

[0089] The preparation method of the dipping solution is the same as that of Example 1.

[0090] The immersion treatment method is the same as that in Example 1.

[0091] Example 3

[0092] An environmentally friendly adhesive composition for fiber surface treatment, the single-bath method formula ratio is as follows by weight:

[0093] The preparation method of the dipping solution is the same as that of Example 1.

[0094] Dipping treatment method: Dip the fiber cord in the dipping liquid for 3 seconds, then dry and cure in an oven. The drying temperature is 150°C, the drying time is 70 seconds, and the curing temperature is 230°C, and the curing time is 70 seconds.

[0095] Example 4

[0096] An environmentally friendly adhesive composition for fiber surface treatment, the single-bath method formula ratio is as follows by weight:

[0097] The preparation method of the dipping solution is the same as that of Example 1.

[0098] The immersion treatment method is the same as that in Example 3.

[0099] Example 5

[0100] An environmentally friendly adhesive composition for fiber surface treatment, the single-bath method formula ratio is as follows by weight:

[0101] Preparation method of the impregnation solution: Add nano-attapulgite and deionized water to a beaker and vigorously stir the solution at 800 rpm with an electric stirrer at 25°C for 1 hour. After that, the solution is ultrasonically stirred with the power of the ultrasonic equipment being 400W and the ultrasonic stirring time being 1 hour to obtain a dispersed filler. Then, all components (except latex) are added to deionized water in a predetermined weight ratio and the solution is vigorously stirred at 500 rpm with an electric stirrer at 25°C for 1.5 hours. Subsequently, the solution is added to styrene-butadiene-vinyl pyridine latex and the device is kept at 25°C and vigorously stirred for 2 hours. During the stirring process, the pH of the impregnation solution is adjusted to 11.0-12.0 by adding an ammonia solution.

[0102] Immersion treatment method: same as Example 3.

[0103] Example 6

[0104] An environmentally friendly adhesive composition for fiber surface treatment, the single-bath method formula ratio is as follows by weight:

[0105] The preparation method of the impregnation solution is as follows: nano-attapulgite and deionized water are added to a beaker, and a mixed solution of modifier KH550 / ethanol (KH550 / ethanol volume ratio of 2:1, ethanol (purity ≥95wt%)) (the amount of KH550 is 10wt% of the amount of filler) is slowly added to the mixed solution of nano-attapulgite and deionized water. The solution is vigorously stirred at 800 rpm with an electric stirrer at 25°C for 1 hour. The solution is then ultrasonically stirred at a power of 400W for 1 hour to obtain dispersed modified attapulgite. Then, all components (except latex) are added to deionized water at a predetermined weight ratio, and the solution is vigorously stirred at 500 rpm with an electric stirrer at 25°C for 1.5 hours. Subsequently, the solution was added to the styrene-butadiene-vinylpyridine latex, and the apparatus was kept at 25° C. with vigorous stirring for 2 h. During the stirring process, the pH of the impregnation solution was adjusted to 11.0-12.0 by adding an aqueous ammonia solution.

[0106] Immersion treatment method: same as Example 3.

[0107] Example 7

[0108] An environmentally friendly adhesive composition for fiber surface treatment, the single-bath method formula ratio is as follows by weight:

[0109] Preparation method of dipping solution: same as Example 6.

[0110] Immersion treatment method: same as Example 3.

[0111] Comparative Example 1

[0112] Comparative Example 1 is a traditional RFL dipping process, and the RFL formula is as follows:

[0113] Preparation of RFL: Sodium hydroxide and deionized water were added to a beaker and stirred vigorously at 500 rpm with an electric stirrer for 10 min. Resorcinol was then added and stirred for 10 min. Finally, a 37 wt% formaldehyde solution was added and stirred at room temperature for 6 h to obtain a homogeneous reaction solution.

[0114] The above solution was added to VP latex (solid content 40 wt%), stirred at room temperature for 1 hour, and ammonia water was added before the stirring was almost finished to finally obtain the RFL dipping solution.

[0115] RFL impregnation treatment method: The fiber cord is immersed in the impregnation liquid for 3 seconds, and then dried and cured in an oven. The drying temperature is 150℃, the drying time is 70s, and the curing temperature is 230℃, and the curing time is 70s.

[0116] Examples 1-7 adopt the single bath method to treat the fiber cords. The cords used in Examples 1, 2, and 3 are nylon 66 cords (930dtex / 2), and the cords used in Examples 4, 5, 6, and 7 are nylon 66 cords (1400dtex / 2). The cords used in Comparative Examples 1 and 2 are RFL single bath treated fiber cords. The cords used in Comparative Example 1 are nylon 66 cords (930dtex / 2), and the cords used in Comparative Example 2 are nylon 66 cords (1400dtex / 2).

[0117] The fiber cords treated with immersion treatment in Examples 1-7 and Comparative Examples 1-2 were used to prepare test samples according to the above method, and were subjected to H extraction test, peeling test and cord strength test. The test results are shown in Table 1.

[0118] Table 1 Data of fiber cord treated by single bath method

[0119] As can be seen from the data in the table above, the H extraction performance of Examples 3 and 4 (no filler added) is comparable to that of the comparative RFL treatment, while the peel force is slightly higher than that of RFL. The H extraction force of Example 5 (with unmodified filler added) is approximately 5% higher than that of the comparative RFL, and the peel force is approximately 15% higher. The H extraction force of Example 6 (with modified filler added) is 7% higher than that of the comparative RFL, and the peel force is approximately 20% higher. This demonstrates that the environmentally friendly adhesive composition has excellent static bonding, reaching or even exceeding the bonding level of the RFL system. Furthermore, in terms of dynamic bonding performance (fatigue life), it is significantly superior to the traditional RFL system. The fatigue life of Example 3 is approximately 17% higher than that of Comparative Example 1; the fatigue life of Example 4 is approximately 14% higher than that of Comparative Example 2. Furthermore, the test results of the cord strength show that the adhesive composition does not significantly reduce the strength of the fiber cord itself and does not affect its use. As shown in Examples 4-6, the addition of fillers can further enhance the static adhesion of the adhesive composition. Furthermore, modifying the filler improves its dispersibility in the dipping solution, further enhancing the bonding effect. The experimental results were consistent with expectations. By adding fillers to the dipping solution to control the modulus of the dipping layer and constructing a modulus transition layer between the fiber and rubber, the interfacial adhesion can be improved.

[0120] Examples 8-13 use a double-bath method to treat the fiber cords. The cords used in Examples 7 and 8 are high-strength nylon 66 cords (1400dtex / 3), the cords used in Examples 9 and 10 are aramid cords (1670dtex / 2), the cords used in Examples 11 and 12 are polyester cords (1670dtex / 2), and the cords used in Examples 13 and 14 are aramid nylon mixed cords (AF1670dtex / 2+PA2100dtex / 1). The cords used in Comparative Examples 3, 4, 5 and 6 are RFL double-bath treated fiber cords, the cords used in Comparative Example 3 are high-strength nylon 66 cords (1400dtex / 3), the cords used in Comparative Example 4 are aramid cords (1670dtex / 2), the cords used in Comparative Example 5 are polyester cords (1670dtex / 2), and the cords used in Comparative Example 6 are aramid nylon blended cords (AF1670dtex / 2+PA2100dtex / 1).

[0121] Example 8

[0122] An environmentally friendly adhesive composition for fiber surface treatment, the double-bath method formula ratio is as follows by weight:

[0123] Preparation method of the first bath dipping solution: add sorbitol glycidyl ether, ε-caprolactam-terminated diphenylmethane diisocyanate and deionized water into a beaker in proportion, and stir vigorously at 500 rpm with an electric stirrer at 25°C for 1 hour.

[0124] Preparation method of the second bath dipping solution: add aliphatic polyurethane dispersion resin, glycerol glycidyl ether, m-phenylenediamine, and 2-ethyl-4-methylimidazole into deionized water according to the predetermined feeding ratio, and stir vigorously at 500 rpm with an electric stirrer at 25°C for 1 hour.

[0125] The above solution was added to the styrene-butadiene-vinyl pyridine latex and stirred for 2 hours. During the stirring process, the pH of the impregnation solution was adjusted to 11.0-12.0 by adding an ammonia solution.

[0126] Dipping treatment method: first, place the fiber in the first bath dipping solution, dip it at room temperature for 3 seconds, dry it at 150°C for 70 seconds, and cure it at 230°C for 70 seconds; then place the fiber in the second bath dipping solution, dip it at room temperature for 3 seconds, dry it at 150°C for 70 seconds, and cure it at 230°C for 70 seconds.

[0127] Example 9

[0128] An environmentally friendly adhesive composition for fiber surface treatment, the double-bath method formula ratio is as follows by weight:

[0129] Preparation method of the first bath dipping solution: same as Example 8.

[0130] Preparation of the second bath impregnation solution: Add polycarbonate polyurethane dispersion resin, glycerol glycidyl ether, m-phenylenediamine, and 2-ethyl-4-methylimidazole to deionized water in the predetermined ratio and vigorously stir at 500 rpm with an electric stirrer at 25°C for 1 hour. This solution is then added to styrene-butadiene-vinyl pyridine latex and stirred for a further 2 hours. During this stirring process, the pH of the impregnation solution is adjusted to 11.0-12.0 by adding aqueous ammonia solution.

[0131] Immersion treatment method: same as Example 8.

[0132] Example 10

[0133] An environmentally friendly adhesive composition for fiber surface treatment, the double-bath method formula ratio is as follows by weight:

[0134] The preparation method of the first bath dipping solution is the same as that of Example 8.

[0135] The second bath dipping solution is prepared by adding nano-attapulgite and deionized water to a beaker, slowly adding a mixed solution of modifier KH550 / ethanol (KH550 / ethanol volume ratio of 2:1, ethanol (purity ≥ 95 wt%)) (KH550 amount is 10 wt% of the filler amount) to the mixed solution of nano-attapulgite and deionized water, and vigorously stirring the solution at 800 rpm with an electric stirrer at 25°C for 1 hour. The solution is then ultrasonically stirred at a power of 400 W for 1 hour to obtain dispersed modified attapulgite. Subsequently, all components (except latex) are added to deionized water at a predetermined weight ratio, and the solution is vigorously stirred at 500 rpm with an electric stirrer at 25°C for 1.5 hours. Subsequently, the solution was added to the styrene-butadiene-vinylpyridine latex, and the apparatus was kept at 25° C. with vigorous stirring for 2 h. During the stirring process, the pH of the impregnation solution was adjusted to 11.0-12.0 by adding an aqueous ammonia solution.

[0136] Immersion treatment method: same as Example 8.

[0137] Example 11

[0138] An environmentally friendly adhesive composition for fiber surface treatment, the double-bath method formula ratio is as follows by weight:

[0139] The preparation method of the first bath dipping solution is the same as that of Example 8.

[0140] The preparation method of the second bath dipping solution is the same as that of Example 10.

[0141] Dipping treatment method: first, place the fiber in the first bath dipping solution, dip it at room temperature for 3 seconds, dry it at 150°C for 70 seconds, and cure it at 230°C for 70 seconds; then place the fiber in the second bath dipping solution, dip it at room temperature for 3 seconds, dry it at 150°C for 70 seconds, and cure it at 250°C for 70 seconds.

[0142] Example 12

[0143] An environmentally friendly adhesive composition for fiber surface treatment, the double-bath method formula ratio is as follows by weight:

[0144] The preparation method of the first bath dipping solution is the same as that of Example 8.

[0145] The preparation method of the second bath dipping solution is the same as that of Example 10.

[0146] The immersion treatment method is the same as that in Example 11.

[0147] Example 13

[0148] An environmentally friendly adhesive composition for fiber surface treatment, the double-bath method formula ratio is as follows by weight:

[0149] The preparation method of the first bath dipping solution is the same as that of Example 8.

[0150] The preparation method of the second bath dipping solution is the same as that of Example 10.

[0151] Dipping treatment method: first, place the fiber in the first bath dipping solution, dip it at room temperature for 3 seconds, dry it at 165°C for 60 seconds, and cure it at 230°C for 60 seconds; then place the fiber in the second bath dipping solution, dip it at room temperature for 3 seconds, dry it at 165°C for 60 seconds, and cure it at 250°C for 60 seconds.

[0152] Example 14

[0153] An environmentally friendly adhesive composition for fiber surface treatment, the double-bath method formula ratio is as follows by weight:

[0154] The preparation method of the first bath dipping solution is the same as that of Example 8.

[0155] The preparation method of the second bath dipping solution is the same as that of Example 10.

[0156] The immersion treatment method is the same as that in Example 13.

[0157] Example 15

[0158] An environmentally friendly adhesive composition for fiber surface treatment, the double-bath method formula ratio is as follows by weight:

[0159] The preparation method of the first bath dipping solution is the same as that of Example 8.

[0160] The preparation method of the second bath dipping solution is the same as that of Example 10.

[0161] The immersion treatment method is the same as that in Example 11.

[0162] Example 16

[0163] An environmentally friendly adhesive composition for fiber surface treatment, the double-bath method formula ratio is as follows by weight:

[0164] The preparation method of the first bath dipping solution is the same as that of Example 8.

[0165] The preparation method of the second bath dipping solution is the same as that of Example 10.

[0166] The immersion treatment method is the same as that in Example 11.

[0167] Comparative Example 3

[0168] Comparative Example 3 is a traditional RFL dipping process, and the double-bath RFL formula is as follows:

[0169] Preparation method of the first bath dipping solution: add sorbitol glycidyl ether, ε-caprolactam-terminated diphenylmethane diisocyanate and deionized water into a beaker in proportion, and stir vigorously at 500 rpm with an electric stirrer at 25°C for 1 hour.

[0170] Preparation of the second bath dip solution: sodium hydroxide and deionized water were added to a beaker and vigorously stirred at 500 rpm with an electric stirrer for 10 minutes, then resorcinol was added and stirred for 10 minutes, and finally a formaldehyde aqueous solution (37 wt%) was added and stirred at room temperature for 6 hours to obtain a uniform reaction solution;

[0171] The above solution was added to VP latex (solid content 40 wt%), stirred at room temperature for 1 hour, and ammonia water was added before the stirring was almost finished to finally obtain the RFL dipping solution.

[0172] RFL dipping treatment method: first, place the fiber in the first bath dipping solution, dip it at room temperature for 3 seconds, dry it at 150°C for 70 seconds, and cure it at 230°C for 70 seconds; then place the fiber in the second bath dipping solution, dip it at room temperature for 3 seconds, dry it at 150°C for 70 seconds, and cure it at 230°C for 70 seconds.

[0173] The dipping solution formula and treatment process of Comparative Examples 4, 5 and 6 are the same as those of Comparative Example 3, except that the fibers treated are different. The cord used in Comparative Example 3 is high-strength nylon 66 cord (1400dtex / 3), the cord used in Comparative Example 4 is aramid cord (1670dtex / 2), the cord used in Comparative Example 5 is polyester cord (1440dtex / 2), and the cord used in Comparative Example 6 is aramid nylon mixed cord (AF1670dtex / 2+PA2100dtex / 1).

[0174] The fiber cords treated with immersion treatment in Examples 8-16 and Comparative Examples 3-5 were used to prepare test samples according to the above method, and were subjected to H extraction test, peeling test and cord strength test. The test results are shown in Table 2.

[0175] Table 2 Data of fiber cord treated by double bath method

[0176] As shown in Table 2, after two-bath treatment, the H-extraction force of Example 10 is comparable to that of Comparative Example 3, but the peel force is approximately 12% higher, and the fatigue life is approximately 26% higher. The H-extraction force of Example 12 is approximately 8% higher, the peel force is approximately 14% higher, and the fatigue life is approximately 93% higher than that of Comparative Example 4. The H-extraction force of Example 14 is approximately 10% higher, the peel force is approximately 10% higher, and the fatigue life is approximately 171% higher than that of Comparative Example 5. The H-extraction force of Example 16 is comparable to that of Comparative Example 6, the peel force is approximately 6% higher, and the fatigue life is approximately 31% higher. This demonstrates that this novel environmentally friendly adhesive composition exhibits excellent bonding performance. The bonding strength achieved with various cords (high-strength nylon, aramid, polyester, and aramid-nylon blends) reaches or even exceeds the bonding level of conventional RFL treatments, and its dynamic bonding performance surpasses that of conventional RFL systems. A comparison of Examples 8-10, 11-12, 13-14, and 15-16 shows that the addition of modified fillers further enhances the adhesion between the fiber and the rubber, consistent with the results of the one-bath treatment of nylon 66 cord in Examples 4-7. Furthermore, the tensile strength of high-strength nylon cord, aramid cord, polyester cord, and aramid-nylon blended cord did not change significantly after dipping, demonstrating that this method does not damage the fiber's inherent strength or affect its performance.

Claims

1. An adhesive composition for fiber surface treatment, comprising or consisting of the following components in parts by weight:

2. The adhesive composition according to claim 1, wherein The composition comprises or consists of the following components in parts by weight:

3. The adhesive composition according to claim 1, characterized in that The composition comprises: A) a first dipping solution, wherein the first dipping solution comprises or consists of the following components: The first epoxy resin is 0.1-5 parts; preferably 1.2-1.8 parts 1-15 parts of blocked isocyanate; preferably 3-4.5 parts 100 parts of the first solvent; as well as B) a second dipping solution, wherein the second dipping solution comprises or consists of the following components: 3-16 parts of polyurethane dispersion resin; preferably 3.3-4.1 parts The second epoxy resin is 0.5-5 parts; preferably 1.5-2.0 parts Curing agent 0.1-3 parts; preferably 0.4-2.1 parts 20-50 parts of rubber latex; preferably 26-27.5 parts 100 parts of the second solvent; Filler 0-20 parts; preferably 0.4-2.7 parts, The first dipping solution and the second dipping solution are stored in two separate containers.

4. The adhesive composition according to any one of claims 1 to 3, characterized in that The polyurethane dispersion resin includes at least one of polycarbonate-based urethane, polyester-based urethane, polyacrylic urethane, polyurea polyurethane, 1,5-naphthalene diisocyanate (NDI) type polyurethane, para-phenylene diisocyanate (PPDI) type polyurethane, dimethyl diphenyl diisocyanate (TODI) type polyurethane or toluene diisocyanate (TDI) type polyurethane; preferably, it is an aliphatic polyurethane dispersion resin and / or a polycarbonate polyurethane dispersion resin.

5. The adhesive composition according to claim 1 or 2, characterized in that The epoxy resin includes at least one of a glycidyl ether type compound, a phenolic epoxy resin and a bisphenol type epoxy resin; preferably, the epoxy resin is selected from one or more of bisphenol A epoxy resin, epoxidized linear phenolic resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,2-propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, diglycidyl ether, glycerol glycidyl ether, trimethylolpropane glycidyl ether, tetraphenol ethane tetraglycidyl ether epoxy resin, resorcinol bisglycidyl ether type epoxy resin, sorbitol glycidyl ether and bisresorcinol formal tetraglycidyl ether; more preferably, glycerol glycidyl ether and / or sorbitol glycidyl ether.

6. The adhesive composition according to claim 3, characterized in that The first epoxy resin and the second epoxy resin are the same as or different from each other, and are independently selected from at least one of glycidyl ether type compounds, phenolic epoxy resins and bisphenol epoxy resins; preferably selected from one or more of bisphenol A epoxy resin, epoxidized linear phenolic resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,2-propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, diglycidyl ether, glycerol glycidyl ether, trimethylolpropane glycidyl ether, tetraphenolyl ethane tetraglycidyl ether epoxy resin, resorcinol diglycidyl ether type epoxy resin, sorbitol glycidyl ether and bisresorcinol formal tetraglycidyl ether; more preferably, the first epoxy resin is sorbitol glycidyl ether; the second epoxy resin is glycerol glycidyl ether.

7. The adhesive composition according to any one of claims 1 to 3, characterized in that The curing agent includes an imidazole curing agent and / or an amine curing agent; Preferably, the imidazole curing agent is selected from one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole and 1-cyanoethyl-2-undecylimidazole; more preferably 2-ethyl-4-methylimidazole; Preferably, the amine curing agent is selected from one or more of hyperbranched polyamide, hyperbranched polyethyleneimine, supramolecular polyoxyethyleneamine, polyoxyethylenediamine, polyamide, dicyandiamide, piperazine, m-xylenediamine and m-phenylenediamine; more preferably, piperazine and / or m-phenylenediamine.

8. The adhesive composition according to any one of claims 1 to 3, characterized in that The blocked isocyanate is a blocked isocyanate formed by isocyanate and a blocking agent. Preferably, the isocyanate is selected from one or more of trimethyl-1,6-hexamethylene diisocyanate, tetramethylene diisocyanate, tetramethyl diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, isophorone diisocyanate and diphenylmethane diisocyanate, more preferably diphenylmethane diisocyanate; Preferably, the blocking agent is selected from one or more of ε-caprolactam, butanone oxime and phenol; more preferably, ε-caprolactam.

9. The adhesive composition according to claim 1 or 2, characterized in that The solvent is an aqueous solvent, preferably water, more preferably deionized water.

10. The adhesive composition according to claim 3, characterized in that The first solvent and the second solvent are the same or different, and are each independently an aqueous solvent, preferably water, and more preferably deionized water.

11. The adhesive composition according to any one of claims 1 to 3, characterized in that The filler is selected from one or more of nano-silicon dioxide, carbon black, nano-titanium dioxide, nano-zinc oxide, nano-iron oxide, nano-calcium oxide, nano-calcium carbonate, carbon nanotubes, attapulgite, nano-cellulose, halloysite, nano-aramid fiber, basalt fiber, nano-whiskers, graphene oxide, montmorillonite, mica, kaolin and hydrotalcite; preferably attapulgite.

12. The adhesive composition according to any one of claims 1 to 3, characterized in that The filler is a filler treated with a filler surface modifier; Preferably, the filler surface modifier is selected from one or more of aminosilane coupling agents, epoxysilane coupling agents, alkylsilane coupling agents, isocyanatesilane coupling agents, and polyethersilane coupling agents; preferably at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, bis-[γ-(triethoxysilyl)propyl]tetrasulfide and vinyltriethoxysilane; more preferably γ-aminopropyltriethoxysilane.

13. The adhesive composition according to any one of claims 1 to 3, characterized in that The rubber latex is selected from at least one of butyl pyrrolidone latex, styrene butadiene latex, styrene butadiene pyrrolidone latex, chloroprene latex, nitrile latex, chlorosulfonated polyethylene latex, epoxidized natural rubber latex, natural latex and acrylate latex; preferably, the rubber latex is at least one of butyl pyrrolidone latex, styrene butadiene latex and natural latex; the solid content of the rubber latex is 20 to 60 wt%.

14. A method for processing fiber, comprising: Step 1) placing the fiber in a dipping solution for dipping, wherein the dipping solution is prepared from the composition according to any one of claims 1, 2, and 4-13; Step 2) drying and curing the impregnated fibers obtained in step 1).

15. The processing method according to claim 14, characterized in that: The impregnation temperature is 10-40°C and the time is 2-60s; the drying temperature is 100-170°C and the time is 30-600s; the curing temperature is 180-260°C and the time is 30-600s. The pH of the impregnation solution is adjusted to 8.0-12.0 before use.

16. A method for processing fiber, comprising the following steps: Step A) placing the fiber in a first dipping solution for dipping, wherein the first dipping solution comprises or consists of the following components: 0.1-5 parts of the first epoxy resin; 1-15 parts of blocked isocyanate; 100 parts of the first solvent; Step B) drying the fibers treated in step A) and then curing them; Step C) placing the fiber treated in step B) in a second dipping solution for dipping, wherein the second dipping solution comprises or consists of the following components: Step D) drying and curing the fibers treated in step C).

17. The processing method according to claim 16, characterized in that: In step A), the impregnation is carried out at a temperature of 10-40° C. for 2-60 seconds; in step B), the drying is carried out at a temperature of 100-170° C. for 30-600 seconds; and in step B), the curing is carried out at a temperature of 180-260° C. for 30-600 seconds.

18. The processing method according to claim 16 or 17, characterized in that: In step C), the impregnation is carried out at a temperature of 10-40°C for 2-60 seconds; in step D), the drying is carried out at a temperature of 100-170°C for 30-600 seconds; and in step B), the curing is carried out at a temperature of 180-260°C for 30-600 seconds.

19. The processing method according to any one of claims 16 to 18, characterized in that: Before use, the pH of the second dipping solution is adjusted to be greater than 7.5, preferably 8.0-12.

0.

20. The processing method according to any one of claims 14 to 19, characterized in that: The fiber is rayon, nylon 6, nylon 66, meta- or para-aramid fiber, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, carbon fiber or mixed twisted cords of the above fibers; The fiber is in a form selected from monofilament, bundled yarn, twisted cord, canvas, cord fabric or a combination thereof.

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