Preparation of impregnation liquid for fiber surface treatment and green two-bath impregnation method

Abstract

The invention relates to a green two-bath method fiber surface impregnation treatment system and a preparation method and an impregnation treatment method thereof. The gum dipping system comprises a first-bath gum dipping solution and a second-bath gum dipping solution. Wherein the first-bath dipping solution comprises biomass and deionized water. The second-bath dipping solution comprises episulfide resin, a curing agent, rubber latex and deionized water. The green two-bath fiber surface impregnation treatment method provided by the invention achieves a bonding effect slightly superior to that of RFL treatment, and the fibers treated by the method are basically free of damage and can effectively replace an RFL impregnation system.

Description

Technical field:

[0001] The invention belongs to the field of resin dipping, and in particular relates to a green two-bath fiber surface resin dipping treatment system and a preparation method and a resin dipping treatment method. Background technology:

[0002] Fiber-rubber composites are widely used, and are often used in tires, high-pressure special hoses, rubber conveyor belts and other fields. This material combines the good elasticity of the rubber matrix to withstand strain and the high stiffness and high strength of the fiber skeleton to resist stress. The interfacial bonding problem between the fiber and the rubber is the key to determining the high-performance fiber reinforcement and stress transfer efficiency. The traditional method in the industry is the resorcinol-formaldehyde-latex (RFL) dipping treatment method, which has been used for more than 60 years, and RFL dipping technology is currently a fiber treatment method with good bonding effect and low production cost. However, in the "Catalogue of Toxic and Hazardous Raw Materials (Products) Encouraged by the State (2016 Edition)", resorcinol and formaldehyde in the RFL system have been listed as carcinogens. Therefore, it is urgent and important to explore new environmentally friendly dipping treatment methods while ensuring the mechanical properties and interfacial bonding properties of the fiber.

[0003] In response to this problem, there are many green fiber surface modification studies, using environmentally friendly dipping systems to replace RFL dipping systems. CN105839413 discloses a dipping system composed of epoxy resin, amine curing agent, and latex, and its bonding effect is better than the RFL treatment level. CN105839413 uses epoxy resin and rubber latex dipping liquid to treat fiber canvas. After treatment, the adhesion of the fiber-rubber composite material can reach a level slightly lower than that of RFL; CN106120350A discloses an impregnation treatment system containing tannic acid, polyamine, and latex. The bonding performance of polyester cord treated at high temperature by this method is equivalent to that of RFL.

[0004] Although the prior art has made some improvements in improving the bonding performance between fiber and rubber, there are still some problems in the prior art, mainly including that the dipping method has poor treatment effect on high-strength and high-modulus fiber, the reaction activity of the dipping solution is not high, so that the curing temperature of the dipping solution does not match the vulcanization time of the fiber-rubber composite material, or there is a problem of complex process. Therefore, in order to solve the above problems, the present invention proposes a green two-bath fiber surface dipping treatment system and dipping treatment method, which can be quickly cured at low temperature. The dipping system can achieve the treatment effect of the RFL dipping system, and the system does not contain formaldehyde and resorcinol, and will not cause harm to the environment and human body. Summary of the invention:

[0005] The present invention provides a fiber surface treatment dipping process, comprising the following steps:

[0006] Firstly, the nylon fiber cord (1400dtex / 2) is placed in a dipping machine for dipping. The drying temperature of the first dipping solution is 100℃-150℃, the line tension is 5N-7N, the heat treatment temperature is 136℃-160℃, and the line tension is 5N-7N; the drying temperature of the second dipping solution is 100℃-150℃, the line tension is 7N-10N, the heat treatment temperature is 160℃-230℃, and the line tension is 8.5N-12N. Finally, the dipping solution is attached to the fiber surface to obtain the dipped fiber.

[0007] The invention aims to provide a green dipping system for fiber surface treatment, comprising a first-bath dipping solution and a second-bath dipping solution.

[0008] One of the bath dipping solutions includes: 1) biomass type 1 and deionized water; 2) biomass type 2 and deionized water.

[0009] The second bath dipping solution includes: episulfide resin, curing agent, rubber latex and deionized water.

[0010] According to the embodiment of the green two-bath fiber surface treatment dipping system, the biomass 1 is at least one of sugars, amino acids and tannins. The sugars are preferably at least one of sucrose, glucose, fructose, maltose, sucrose and lactose; the amino acids are preferably at least one of tryptophan, cysteine, aspartic acid, glycine and polyaspartic acid; the tannins have a structure such as Figure 1 As shown, the R group is one or more of a hydroxyl group (-OH), a carbonyl group (-C=O), an amino group (-NH2) and a thiol group (-SH).

[0011] According to the embodiment of the green two-bath fiber surface treatment dipping system, the biomass 2 is at least one of itaconic acid, fumaric acid and itaconic acid glyceride. The structures of itaconic acid, fumaric acid and itaconic acid glyceride are as follows: Figure 2-Figure 4 As shown, the R group is one or more of a hydroxyl group (-OH), a carbonyl group (-C=O), an amino group (-NH2) and a thiol group (-SH). The steps for synthesizing itaconate glyceride are as follows Figure 5 shown.

[0012] According to the implementation of the green two-bath fiber surface treatment dipping system, the episulfide resin is selected from at least one of bisphenol A episulfide resin, bisphenol F episulfide resin, and aliphatic difunctional episulfide resin, and the structure of the bisphenol A episulfide resin, bisphenol F episulfide resin, and aliphatic difunctional episulfide resin is as follows: Figure 6-Figure 8 As shown, the R group is one or more of a hydroxyl group (-OH), a carbonyl group (-C=O), an amino group (-NH2) and a thiol group (-SH).

[0013] According to the embodiment of the green two-bath fiber surface treatment dipping system, the curing agent is a curing agent commonly used in the art, preferably one or more of an imidazole curing agent or an amine curing agent. The imidazole curing agent is preferably at least one 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 or 1-cyanoethyl-2-undecylimidazole; the amine curing agent is preferably at least one of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 4-dimethylaminopyridine, dimethylaminodimethanone, polyoxyethylenediamine hyperbranched polyethyleneimine.

[0014] According to the implementation method of the green two-bath fiber surface treatment dipping system, the solid content of the rubber latex is preferably 20%-60%, and is selected from at least one of styrene-butadiene latex, butadiene-pyrrolidone latex, nitrile latex, chloroprene latex, chlorosulfonated polyethylene latex and natural latex.

[0015] According to the implementation method of the green two-bath fiber surface treatment dipping system, the one-bath dipping solution includes 0.3-12 parts of biomass and 300 parts of deionized water in parts by weight; preferably, the one-bath dipping solution includes 0.5-6 parts of biomass and 300 parts of deionized water in parts by weight.

[0016] According to the embodiment of the green two-bath fiber surface treatment dipping system, the two-bath dipping solution comprises, by weight, 3-20 parts of episulfide resin, 0.1-4 parts of curing agent, 50-200 parts of rubber latex and 100 parts of deionized water. Preferably, by weight, the two-bath dipping solution comprises, by weight, 3-10 parts of episulfide resin, 0.1-2 parts of curing agent, 60-150 parts of rubber latex and 100 parts of deionized water.

[0017] The present invention also provides a method for preparing the above-mentioned green two-bath fiber surface treatment dipping system, comprising the following steps:

[0018] The first step is to add biomass into deionized water and stir to obtain a first-bath dipping solution; the second step is to add episulfide resin into deionized water and stir to obtain a uniform dispersion, then add a curing agent, stir at room temperature to obtain a uniform reaction solution, and finally add diluted rubber latex and stir to obtain a second-bath dipping solution.

[0019] The preferred preparation method comprises: a first step of adding a specified amount of biomass to deionized water and stirring for 60 min-120 min to obtain a uniform reaction solution, thereby preparing a first-bath dipping solution; a second step of adding a specified amount of episulfide resin to deionized water and stirring to obtain a uniform dispersion, then adding a curing agent, stirring at room temperature for 1 h-3 h to obtain a uniform reaction solution, and finally adding rubber latex and continuing to stir for 1 h-3 h to obtain a second-bath dipping solution.

[0020] The invention also provides a method for preparing a fiber-rubber composite material by using the above-mentioned dipping solution.

[0021] The preparation method of H extraction force test specimen is as follows:

[0022] Referring to the national standard GB / T2942-2009, the standard rubber was laid into the H extraction test mold, the upper end of the cord was fixed to the upper and lower ends of the mold and tied to a 50g weight to pull it straight, and finally it was placed on a 136℃ flat vulcanizer for vulcanization with a vulcanization pressure of 15MPa and a vulcanization time of 50min. After the sample was cooled to room temperature, the H extraction force test specimen was obtained.

[0023] The preparation method of the peeling force test strip is as follows:

[0024] With reference to the national standard GB / T9101-2003, the standard rubber was spread into the peeling mold, and a certain size of cellophane and rubber sheet were attached to the fixed fiber to prepare the peeling specimen. Finally, it was placed on a 160℃ flat vulcanizer for vulcanization. The vulcanization pressure was 2.354MPa and the vulcanization time was 20min. After the sample was cooled to room temperature, the peeling force test specimen was obtained.

[0025] The preparation method of the cord breaking strength test specimen is as follows:

[0026] With reference to the standard GB / T32108-2015, the dipped cord was clamped in a tensile testing machine for tensile testing at a speed of 300±5mm / min.

[0027] Advantages and features of the present invention:

[0028] 1. The episulfide resin in the two-bath dipping solution prepared by the present invention has high activity and can be cured quickly.

[0029] 2. The dipping solution of the present invention does not contain resorcinol and formaldehyde, thus meeting environmental protection requirements and reducing harm to the environment and human body.

[0030] 3. The dipping solution has good stability, will not flocculate when placed at room temperature for a long time, and the adhesive performance decreases slightly. Description of the drawings:

[0031] Figure 1 It is the molecular structure of tannic acid.

[0032] Figure 2 It is the molecular structure of itaconic acid.

[0033] Figure 3 It is the molecular structure of fumaric acid.

[0034] Figure 4 It is the molecular structure of itaconate glyceryl.

[0035] Figure 5 This is the synthesis step of itaconate glyceride.

[0036] Figure 6 It is the molecular structure of bisphenol A episulfide resin.

[0037] Figure 7 It is the molecular structure of bisphenol F episulfide resin.

[0038] Figure 8 It is an aliphatic bifunctional episulfide resin molecular structure. Specific implementation method:

[0039] The present invention will be further described below in conjunction with specific embodiments, and the scope of the present invention is not limited by the specific embodiments, but is limited by the scope of the claims. Those skilled in the art can make various modifications or improvements based on the basic idea of ​​the present invention, but as long as they do not deviate from the basic idea of ​​the present invention, they are all within the scope of the present invention.

[0040] Example 1

[0041] A green two-bath fiber surface treatment dipping system, the formula ratio by weight is shown in Table 1.

[0042] Table 1 Formula of dipping system for green two-bath fiber surface treatment

[0043]

[0044] Preparation of dipping solution: In the first step, 1.8 parts of tannic acid described in the formula are added to 300 parts of deionized water and stirred for 60 minutes to obtain a uniform reaction solution, thereby preparing a one-bath dipping solution; in the second step, 5 parts of E-51 episulfide resin described in the formula are added to 50 parts of deionized water and stirred to obtain a uniform dispersion, and then 0.4 parts of triethylenetetramine are added and stirred at room temperature for 3 hours to obtain a uniform reaction solution, and finally 100 parts of rubber latex diluted with 50 parts of deionized water are added and stirred for 3 hours to obtain a two-bath dipping solution.

[0045] Example 2

[0046] A green two-bath fiber surface treatment dipping system, the formula ratio by weight is shown in Table 2.

[0047] Table 2 Formula of dipping system for green two-bath fiber surface treatment

[0048]

[0049] Preparation of dipping solution: In the first step, 1.8 parts of itaconate glyceride described in the formula are added to 300 parts of deionized water and stirred for 60 minutes to obtain a uniform reaction solution, thereby preparing a one-bath dipping solution; in the second step, 7 parts of E-44 episulfide resin described in the formula are added to 50 parts of deionized water and stirred to obtain a uniform dispersion, and then 0.6 parts of 2-methylimidazole are added and stirred at room temperature for 3 hours to obtain a uniform reaction solution, and finally 100 parts of rubber latex diluted with 50 parts of deionized water are added and stirred for 3 hours to obtain a two-bath dipping solution.

[0050] Example 3

[0051] A green two-bath fiber surface treatment dipping system, the formula ratio by weight is shown in Table 3.

[0052] Table 3 Green two-bath fiber surface treatment dipping system formula

[0053]

[0054] Preparation of dipping solution: In the first step, 1.8 parts of tannic acid described in the formula are added to 300 parts of deionized water and stirred for 60 minutes to obtain a uniform reaction solution, thereby preparing a one-bath dipping solution; in the second step, 5 parts of E-51 episulfide resin described in the formula are added to 50 parts of deionized water and stirred to obtain a uniform dispersion, and then 0.3 parts of triethylenetetramine and 0.3 parts of 2-methylimidazole are added, and stirred at room temperature for 3 hours to obtain a uniform reaction solution, and finally 100 parts of rubber latex diluted with 50 parts of deionized water are added, and stirring is continued for 3 hours to obtain a two-bath dipping solution.

[0055] Example 4

[0056] A green two-bath fiber surface treatment dipping system, the formula ratio by weight is shown in Table 4.

[0057] Table 4 Green two-bath fiber surface treatment dipping system formula

[0058]

[0059] Preparation of dipping solution: In the first step, 1.5 parts of itaconic acid compound and 1.5 parts of fumaric acid compound described in the formula are added to 300 parts of deionized water and stirred for 60 minutes to obtain a uniform reaction solution, thereby obtaining a one-bath dipping solution; in the second step, 5 parts of E-51 episulfide resin described in the formula are added to 50 parts of deionized water and stirred to obtain a uniform dispersion, and then 0.4 parts of triethylenetetramine are added and stirred at room temperature for 3 hours to obtain a uniform reaction solution, and finally 100 parts of rubber latex diluted with 50 parts of deionized water are added and stirred for 3 hours to obtain a two-bath dipping solution.

[0060] Example 5

[0061] A green two-bath fiber surface treatment dipping system, the formula ratio by weight is shown in Table 5.

[0062] Table 5 Green two-bath fiber surface treatment dipping system formula

[0063]

[0064] Preparation of dipping solution: In the first step, 2 parts of itaconate glyceride and 1 part of tannic acid described in the formula are added to 300 parts of deionized water and stirred for 60 minutes to obtain a uniform reaction solution, thereby preparing a one-bath dipping solution; in the second step, 3 parts of E-51 episulfide resin described in the formula are added to 50 parts of deionized water and stirred to obtain a uniform dispersion, and then 0.6 parts of 2-methylimidazole are added and stirred at room temperature for 3 hours to obtain a uniform reaction solution, and finally 100 parts of rubber latex diluted with 50 parts of deionized water are added and stirred for 3 hours to obtain a two-bath dipping solution.

[0065] Example 6

[0066] A green two-bath fiber surface treatment dipping system, the formula ratio by weight is shown in Table 6.

[0067] Table 6 Green two-bath fiber surface treatment dipping system formula

[0068]

[0069] Preparation of dipping solution: In the first step, 3 parts of itaconic acid described in the formula are added to 300 parts of deionized water and stirred for 60 minutes to obtain a uniform reaction solution, thereby preparing a one-bath dipping solution; in the second step, 5 parts of E-44 episulfide resin described in the formula are added to 50 parts of deionized water and stirred to obtain a uniform dispersion, and then 0.3 parts of triethylenetetramine and 0.3 parts of 2-methylimidazole are added, and stirred for 3 hours at room temperature to obtain a uniform reaction solution, and finally 40 parts of styrene-butadiene latex and 60 parts of butadiene-pyrrolidone latex diluted with 50 parts of deionized water are added, and stirring is continued for 3 hours to obtain a two-bath dipping solution.

[0070] Comparative Example 1

[0071] The formula of the traditional RFL fiber dipping treatment system is shown in Table 7.

[0072] Table 7 Formula of traditional RFL fiber dipping treatment system

[0073] raw material Mass fraction Deionized water 295 Resorcinol 11 Formaldehyde (37%) 6 Sodium hydroxide 0.3 VP latex (40%) 250 ammonia 11.3

[0074] Preparation of RFL: In the first step, 11 parts of resorcinol and 6 parts of formaldehyde aqueous solution are added into the reaction vessel, and the pH of the solution is adjusted to 8-9 by adding 0.3 parts of NaOH, and ripened at room temperature for 6 hours to obtain RF resin solution; in the second step, 266 parts of VP latex are added, stirred at room temperature for 20 hours, and finally 11.3 parts of ammonia water are added to adjust the pH of the solution to 8-9, and finally a uniform RFL dipping solution is obtained.

[0075] The test results of the embodiments and comparative examples are shown in Table 8.

[0076] Table 8 Comparison of the bonding properties of dipped fibers obtained from Examples 1-6 and conventional RFL dipped solutions

[0077]

[0078] As can be seen from Table 8, the bonding performance between the fiber and rubber treated by the dipping system of the present invention is small, and the fiber tensile strength changes little. The bonding effect of the dipped fiber prepared by the dipping system for green two-bath fiber surface treatment of the present invention exceeds that of the dipped fiber prepared by the RFL system, and the dipped fiber prepared by the present invention does not have a significant loss in tensile strength.

[0079] In summary, the green two-bath fiber surface treatment dipping system proposed in the present invention adds biomass to activate the fiber surface in the first bath, and the episulfide resin reacts with the curing agent in the second bath to enhance the modulus of the dipping interface layer. The bonding performance of the green dipping system is improved without affecting the fiber strength, thereby being able to replace the RFL dipping solution that is toxic and harmful to the environment and human body. The preparation of the dipping solution and the fiber impregnation process are simple, the process is short, the storage stability of the glue solution is good, and the episulfide resin in the two-bath dipping solution has high activity and can be quickly cured, which is beneficial to industrial production.

Claims

1. A green two-bath fiber surface dipping treatment system, characterized in that The dipping system comprises a first-bath dipping solution and a second-bath dipping solution. In parts by weight, the one-bath dipping solution comprises 0.3-12 parts of biomass and 300 parts of deionized water. Preferably, in parts by weight, the one-bath dipping solution comprises 0.5-6 parts of biomass and 300 parts of deionized water. The second-bath dipping solution comprises, by weight, 3-20 parts of episulfide resin, 0.1-4 parts of curing agent, 50-200 parts of rubber latex and 100 parts of deionized water. Preferably, the second-bath dipping solution comprises, by weight, 3-10 parts of episulfide resin, 0.1-2 parts of curing agent, 60-150 parts of rubber latex and 100 parts of deionized water.

2. The green two-bath fiber surface treatment and dipping treatment system according to claim 1 is characterized by: The biomass 1 is selected from at least one of sugars, amino acids and tannins. Sugars are preferably at least one of sucrose, glucose, fructose, maltose, sucrose and lactose; amino acids are preferably at least one of tryptophan, cysteine, aspartic acid, glycine and polyaspartic acid; the structure of tannins is shown in FIG1 , wherein the R group is one or more of hydroxyl (-OH), carbonyl (-C=O), amino (-NH2) and thiol (-SH). The biomass 2 is selected from at least one of itaconic acid, fumaric acid and itaconic acid glyceride. The structures of itaconic acid, fumaric acid and itaconic acid glyceride are shown in Figures 2 to 4, and the R group is one or more of hydroxyl (-OH), carbonyl (-C=O), amino (-NH2) and thiol (-SH). The synthesis steps of itaconic acid glyceride are shown in Figure 5. The episulfide resin is selected from at least one of bisphenol A episulfide resin, bisphenol F episulfide resin, and aliphatic difunctional episulfide resin. The structures of bisphenol A episulfide resin, bisphenol F episulfide resin, and aliphatic difunctional episulfide resin are shown in Figures 6 to 8, wherein the R group is one or more of a hydroxyl group (-OH), a carbonyl group (-C=O), an amino group (-NH2), and a thiol group (-SH).

3. The green two-bath fiber surface treatment and dipping treatment system according to claim 1, characterized in that: The curing agent is selected from the curing agents commonly used in the art, preferably one or more of imidazole curing agents and amine curing agents. The imidazole curing agent is preferably at least one 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 or 1-cyanoethyl-2-undecylimidazole; the amine curing agent is preferably at least one of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 4-dimethylaminopyridine, dimethylaminodimethanone, polyoxyethylenediamine hyperbranched polyethyleneimine.

4. The green two-bath fiber surface treatment and dipping treatment system according to claim 1, characterized in that: The rubber latex has a solid content of preferably 20-60%, and is selected from at least one of styrene-butadiene latex, butylpyrrolidone latex, nitrile-butadiene latex, chloroprene latex, chlorosulfonated polyethylene latex and natural latex.

5. A method for impregnating a fiber surface using a green two-bath impregnation treatment system according to any one of claims 1 to 4, characterized in that The following steps are involved: The first step is to add a specified amount of biomass into deionized water and stir for 60 minutes to 120 minutes to obtain a uniform reaction solution, thereby preparing a first-bath dipping solution; the second step is to add a specified amount of episulfide resin into deionized water and stir to obtain a uniform dispersion, then add a curing agent, stir for 1 hour to 3 hours at room temperature to obtain a uniform reaction solution, and finally add rubber latex and continue stirring for 1 hour to 3 hours to obtain a second-bath dipping solution.

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