Energy-saving and environment-friendly aramid cord dipping solution and rubber material

Abstract

The application discloses an energy-saving and environment-friendly aramid cord dipping liquid and a rubber material, and belongs to the technical field of dipping liquids. The dipping liquid comprises a one-bath dipping liquid and a two-bath dipping liquid which are separately packaged; wherein, according to weight parts, raw materials of the one-bath dipping liquid comprise 5-25 parts of blocked isocyanate, 2-15 parts of flexible multifunctional epoxy resin and 100 parts of deionized water; raw materials of the two-bath dipping liquid comprise 50-250 parts of latex, 5-25 parts of phenolic resin and 100 parts of deionized water; the energy-saving and environment-friendly aramid cord dipping liquid has good water solubility and water dispersibility, is not prone to sticking to a roller, is convenient to clean, does not contain components with high pollution and has environmental friendliness. The aramid fiber product (such as aramid cord) and the rubber matrix after being treated by the dipping liquid have excellent adhesion, and the durability of the rubber composite material is improved.

Description

Technical Field

[0001] This invention relates to the field of impregnation solution technology, and in particular to an energy-saving and environmentally friendly aramid cord impregnation solution and a rubber material. Background Technology

[0002] With the rapid development of modern industry, rubber products have penetrated into fields such as high-end tires, special seals, hoses and cables for extreme environments, especially fiber-rubber composites, which have become key structural and functional materials due to their superior performance. These composites use fiber materials as the skeleton, significantly improving the mechanical strength and wear resistance of rubber products, and also endowing the materials with new functions, such as high-temperature resistance and chemical corrosion resistance, thereby broadening the application range of rubber products in industries such as automotive, aerospace, construction, and electronics.

[0003] Due to the significant differences in polarity and modulus between fibers and rubber, the interfacial bonding strength is low, making adhesion difficult. To enhance the bonding performance between traditional fibers and rubber, researchers have developed a resorcinol-formaldehyde-latex (RFL) adhesive system, which not only offers excellent bonding but also boasts high cost-effectiveness. However, during use, resorcinol and formaldehyde, two harmful chemicals, volatilize during formulation and processing, posing a serious health threat to production workers and potentially causing long-term health risks to product users. Therefore, developing a new impregnation system to replace the traditional RFL impregnation system has become particularly urgent.

[0004] Aramid fiber, also known as aromatic polyamide fiber, is mainly classified into para-aramid (PPTA) and meta-aramid (PMIA). It is a high-performance synthetic fiber with excellent impact resistance, not easily broken under high stress; its stiffness is between that of glass fiber and carbon fiber, providing good mechanical properties and flexibility; it has excellent abrasion and chemical resistance, resisting most high-concentration inorganic acids and exhibiting good alkali resistance. It is widely used in various aspects of the national economy, including defense, aerospace, electromechanical, construction, automotive, and sporting goods.

[0005] Aramid curtain cord is a type of curtain material made from high-strength aramid fibers. It is lightweight, soft, easy to clean, provides good coverage, and has anti-static and antibacterial properties. Aramid curtain cord is primarily used for curtains and partitions in homes and commercial spaces, creating elegant, modern, and minimalist decorative styles. In addition, it is frequently used for partitioning commercial spaces, hanging exhibition materials, and interior decoration.

[0006] However, due to the high surface crystallinity, low surface energy, and high chemical inertness of aramid fibers, the interaction between the aramid cord and the rubber matrix composite interface is weak. Traditional impregnation solutions cannot meet the interfacial bonding strength requirements, resulting in low shear strength of the products and easy delamination, cracking, and other failures of the components during use. This limits the performance of aramid skeleton materials in rubber products.

[0007] Therefore, in order to improve the adhesion performance between aramid cords and rubber matrix, it is particularly important to develop matching surface treatment technologies and special impregnation solutions. Summary of the Invention

[0008] In view of this, the technical problem to be solved by the present invention is to provide an energy-saving and environmentally friendly aramid cord impregnation solution and a rubber material. The energy-saving and environmentally friendly aramid cord impregnation solution has good water solubility and water dispersibility, does not contain highly polluting components, and exhibits excellent adhesion between aramid fibers and the rubber matrix after treatment with it.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] This invention provides an impregnation solution, comprising a pre-packaged one-bath impregnation solution and a two-bath impregnation solution;

[0011] The raw materials of the one-bath impregnation solution, by weight, include 5-25 parts of blocked isocyanate, 2-15 parts of flexible multifunctional epoxy resin, and 100 parts of deionized water.

[0012] The raw materials for the second bath impregnation solution include 50-250 parts latex, 5-25 parts phenolic resin, and 100 parts deionized water.

[0013] The blocked isocyanate is prepared by end-capping isocyanate with a blocking agent, wherein the blocking agent is selected from one or more of oxime blocking agents, phenolic blocking agents, amine blocking agents, and imidazole blocking agents;

[0014] The flexible multifunctional epoxy resin is selected from one or more of isosorbide-based epoxy resin, biophenol-based epoxy resin, rosin-based epoxy resin, and lignin-based epoxy resin.

[0015] The latex is selected from one or more of the following: natural latex, styrene-butadiene latex, polybutadiene latex, butadiene-pyridine latex, carboxylated styrene-butadiene latex, and sulfonic acid-based polystyrene latex.

[0016] The phenolic resin is made from one or more of the following: tannin, cashew phenol, tert-butylphenol, octylphenol, and dodecylphenol.

[0017] The aldehyde used as the raw material for the phenolic resin is selected from one or more of furfural, pyridine-2-carboxaldehyde, and glyoxal.

[0018] Preferably, the blocked isocyanate is 5 to 20 parts by weight; more preferably, it is 5, 10, 15 or 20 parts.

[0019] Preferably, the flexible multifunctional epoxy resin is in the form of 2 parts, 6 parts, 10 parts, or 15 parts.

[0020] Preferably, the latex is 50 to 200 parts; more preferably, it is 50 parts, 100 parts, or 200 parts.

[0021] Preferably, the phenolic resin is in the form of 5 parts, 15 parts, or 25 parts.

[0022] Preferably, the isocyanate is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

[0023] Preferably, the oxime blocking agent is selected from methyl ethyl ketone oxime;

[0024] Preferably, the phenolic blocking agent is selected from 2-hydroxypyridine or 5-chloro-2-hydroxypyridine;

[0025] Preferably, the amine blocking agent is selected from one or more of acetanilide, N-methylacetamide, and methacrylamide;

[0026] Preferably, the imidazole blocking agent is selected from one or more of 2-methylimidazole, 2-ethylimidazole, and 2-isopropylimidazole.

[0027] Preferably, the isosorbide-type epoxy resin of the present invention is selected from isosorbide-based glycidyl ether type epoxy resin and diisosorbide-based glycidyl ether type epoxy resin;

[0028] Preferably, the biophenolic epoxy resin is selected from one or more of eugenol epoxy resin, divanillin diglycidyl ether epoxy resin, divanillin triglycidyl ether epoxy resin, and divanillin tetraglycidyl ether epoxy resin.

[0029] Preferably, the raw material for the blocked isocyanate is selected from toluene diisocyanate and methyl ethyl ketone oxime;

[0030] Alternatively, preferably, the raw material for the blocked isocyanate is selected from diphenylmethane diisocyanate and 2-hydroxypyridine;

[0031] Alternatively, preferably, the raw material for the blocked isocyanate is selected from hexamethylene diisocyanate and methacrylamide;

[0032] Alternatively, preferably, the raw material for the blocked isocyanate is selected from isophorone diisocyanate and 2-methylimidazole.

[0033] Preferably, the flexible multifunctional epoxy resin of the present invention is selected from isosorbide-based glycidyl ether type epoxy resin, rosin-based epoxy resin, lignin-based epoxy resin or divanillin diglycidyl ether epoxy resin.

[0034] Preferably, the latex is selected from a mixture of butyl pyridine latex and carboxylated styrene-butadiene latex, a mixture of butyl pyridine latex and polybutadiene latex, or a mixture of carboxylated styrene-butadiene latex and polybutadiene latex.

[0035] Preferably, the phenolic resin used in this invention is selected from cashew phenol, octylphenol, or dodecylphenol.

[0036] Preferably, the aldehyde used as the raw material for the phenolic resin is selected from pyridine-2-carboxaldehyde or furfural.

[0037] In this invention, the preparation method of the one-bath impregnation solution includes the following steps:

[0038] A block-type isocyanate is mixed with a portion of deionized water, and a flexible multifunctional epoxy resin is added while stirring to obtain a mixture. Then, another portion of deionized water is added and mixed to obtain a one-bath impregnation solution.

[0039] The preparation method of the two-bath impregnation solution includes the following steps:

[0040] (1) Put an appropriate amount of deionized water into the reaction vessel, add sodium hydroxide solid to prepare a solution with a concentration of 3% to 5%, add phenol in small amounts several times into the reaction vessel, then add aldehyde and the catalyst triethylamine to react and obtain the reaction solution; add deionized water and latex to the mixing tank and mix evenly to obtain the mixing system;

[0041] (2) Add the above reaction solution to the above preparation system in batches and mix evenly to obtain the second bath impregnation solution.

[0042] The phenol in step (1) is selected from one or more of tannin, cashew phenol, tert-butylphenol, octylphenol, and dodecylphenol.

[0043] The aldehyde in step (1) is selected from one or more of furfural, pyridine-2-carboxaldehyde, and glyoxal.

[0044] The latex in step (1) is selected from one or more of the following: natural latex, styrene-butadiene latex, polybutadiene latex, butyl pyridine latex, carboxylated styrene-butadiene latex, and sulfonic acid-based polystyrene latex.

[0045] The latex is selected from single latex or compound latex.

[0046] The composite latex is preferably a mixture of butadiene-pyridine latex and carboxylated styrene-butadiene latex, a mixture of butadiene-pyridine latex and polybutadiene latex, or a mixture of carboxylated styrene-butadiene latex and polybutadiene latex.

[0047] The reaction temperature in step (1) is 22–28°C.

[0048] In step (1), the stirring speed in the reactor is controlled at 350±30 rpm, and the reaction time is 2±0.5 hours.

[0049] The above-mentioned methods for preparing one-bath and two-bath impregnation solutions are simple, efficient, highly repeatable, cost-effective, and easy for large-scale industrial production.

[0050] This invention uses a combination of one-bath and two-bath impregnation solutions to impregnate aramid fiber products, maintaining the original high strength and high modulus characteristics of the aramid cord, enhancing the adhesion between the aramid cord and the matrix material, and improving the durability of the composite material.

[0051] The flexible multifunctional epoxy resin component in the impregnation solution of the present invention forms a film on the surface of aramid fiber after curing, which significantly improves the mechanical interlock between aramid fiber and matrix, thereby improving the mechanical properties and fatigue resistance of aramid fiber.

[0052] Furthermore, the present invention uses low-temperature desealing of isocyanate during the impregnation process of aramid cord, so that the impregnation solution can achieve effective bonding of aramid fibers at a relatively low temperature.

[0053] The present invention also provides a rubber material, the raw materials of which include a rubber matrix and aramid cord treated with the above-mentioned impregnation solution.

[0054] Preferably, the H-type pull-out force between the rubber matrix and the aramid cord in the rubber material is 181-236 N / cm.

[0055] Compared with existing technologies, the energy-saving and environmentally friendly aramid cord impregnation solution provided by this invention includes a one-bath impregnation solution and a two-bath impregnation solution. The one-bath impregnation solution, by weight, comprises 5-25 parts of blocked isocyanate, 2-15 parts of flexible multifunctional epoxy resin, and 100 parts of deionized water. The two-bath impregnation solution comprises 50-250 parts of latex, 5-25 parts of phenolic resin, and 100 parts of deionized water. The blocked isocyanate is prepared by end-capping isocyanate with a blocking agent, wherein the blocking agent is selected from oxime blocking agents, phenolic blocking agents, amine blocking agents, and imidazole blocking agents. The adhesive comprises one or more of the following: the flexible multifunctional epoxy resin is selected from one or more of isosorbide-based epoxy resin, biophenolic epoxy resin, rosin-based epoxy resin, and lignin-based epoxy resin; the latex is selected from one or more of natural latex, styrene-butadiene latex, polybutadiene latex, butyl-butadiene latex, carboxylated styrene-butadiene latex, and sulfonic acid-based polystyrene latex; the phenolic resin is selected from one or more of tannin, cashew phenol, tert-butylphenol, octylphenol, and dodecylphenol; the aldehyde is selected from one or more of furfural, pyridine-2-carboxaldehyde, and glyoxal. The energy-saving and environmentally friendly aramid cord impregnation solution of this invention has good water solubility and water dispersibility, is not prone to sticking to rollers, is easy to clean, and does not contain highly polluting components, thus being environmentally friendly. The aramid fiber products (such as aramid cords) treated with the impregnation solution exhibit excellent adhesion to the rubber matrix, improving the durability of the rubber composite material. Detailed Implementation

[0056] To further illustrate the present invention, the energy-saving and environmentally friendly aramid cord impregnation solution and a rubber material provided by the present invention will be described in detail below with reference to embodiments.

[0057] Example 1

[0058] One-bath impregnation solution for preparing energy-saving and environmentally friendly aramid cord

[0059] Add 5 parts of blocked isocyanate (where the isocyanate is toluene diisocyanate and the blocking agent is methyl ethyl ketone oxime) to 50 parts of deionized water and mix. While stirring at 400 rpm, add 2 parts of flexible multifunctional epoxy resin (i.e., isosorbide glycidyl ether type epoxy resin) to obtain a mixture. Then add another 50 parts of deionized water and mix to obtain a one-bath impregnation solution.

[0060] Example 2

[0061] One-bath impregnation solution for preparing energy-saving and environmentally friendly aramid cord

[0062] Add 10 parts of blocked isocyanate (where the isocyanate is diphenylmethane diisocyanate and the blocking agent is 2-hydroxypyridine) to 40 parts of deionized water and mix. While stirring at 380 rpm, add 6 parts of flexible multifunctional epoxy resin (rosin-based epoxy resin) to obtain a mixture. Then add another 60 parts of deionized water and mix to obtain a one-bath impregnation solution.

[0063] Example 3

[0064] One-bath impregnation solution for preparing energy-saving and environmentally friendly aramid cord

[0065] Add 15 parts of blocked isocyanate (hexamethylene diisocyanate and methacrylamide as the blocking agent) to 60 parts of deionized water and mix. While stirring at 410 rpm, add 10 parts of flexible multifunctional epoxy resin (i.e., lignin-based epoxy resin) to obtain a mixture. Then add another 40 parts of deionized water and mix to obtain a one-bath impregnation solution.

[0066] Example 4

[0067] One-bath impregnation solution for preparing energy-saving and environmentally friendly aramid cord

[0068] Add 20 parts of blocked isocyanate (isocyanate is isophorone diisocyanate, and blocking agent is 2-methylimidazole) to 80 parts of deionized water, mix, and while stirring at 420 rpm, add 15 parts of flexible multifunctional epoxy resin (i.e., divanillin diglycidyl ether) to obtain a mixture. Then add another 20 parts of deionized water and mix to obtain a one-bath impregnation solution.

[0069] Example 5

[0070] Two-bath impregnation solution for preparing energy-saving and environmentally friendly aramid cord

[0071] Add an appropriate amount of deionized water to the reactor, add sodium hydroxide to prepare a 3% solution, and add cashew phenol in small amounts several times. Then add furfural and triethylamine catalyst, while maintaining the reactor temperature at 22℃ and the stirring speed at 350 rpm for 2 hours. After the reaction is complete, add 100 parts of deionized water and 50 parts of composite latex of butyl-pyridine latex and carboxylated styrene-butadiene latex to the mixing tank. After stirring evenly, add 15 parts of the liquid in the reactor (i.e., the generated phenolic resin) in batches to the mixing system and continue stirring for 1.5 hours to obtain the two-bath impregnation solution.

[0072] Example 6

[0073] Two-bath impregnation solution for preparing energy-saving and environmentally friendly aramid cord

[0074] Add an appropriate amount of deionized water to the reactor, add sodium hydroxide to prepare a 4% solution, and add dodecylphenol in small amounts several times. Then add pyridine-2-carboxaldehyde and triethylamine catalyst, while maintaining the reactor temperature at 24℃ and the stirring speed at 340 rpm for 1.8 hours. After the reaction is complete, add 100 parts of deionized water and 100 parts of composite latex of butyl-pyridine latex and carboxylated styrene-butadiene latex to the mixing tank. After stirring evenly, add 25 parts of the liquid in the reactor (i.e., the generated phenolic resin) in batches to the mixing system and continue stirring for 1.4 hours to obtain the two-bath impregnation solution.

[0075] Example 7

[0076] Two-bath impregnation solution for preparing energy-saving and environmentally friendly aramid cord

[0077] Add an appropriate amount of deionized water to the reactor, add sodium hydroxide to prepare a 5% solution, and add cashew phenol in small amounts several times. Then add pyridine-2-carboxaldehyde and triethylamine catalyst, while maintaining the reactor temperature at 27°C and the stirring speed at 360 rpm for 2.2 hours. After the reaction is complete, add 100 parts of deionized water and 200 parts of composite latex of butyl-pyridine latex and carboxylated styrene-butadiene latex to the mixing tank. After stirring evenly, add 5 parts of the liquid in the reactor (i.e., the generated phenolic resin) in batches to the mixing system and continue stirring for 1.6 hours to obtain the two-bath impregnation solution.

[0078] Comparative Example 1

[0079] Preparation of traditional impregnation

[0080] Add an appropriate amount of deionized water to the reactor, add sodium hydroxide to prepare a 5% solution, add an appropriate amount of resorcinol to the reactor, then add formaldehyde, while maintaining the reactor temperature at 25℃ and the stirring speed at 360 rpm for 8 hours. After the reaction is complete, add an appropriate amount of deionized water and styrene-butadiene latex to the mixing tank, stir evenly, and then add the liquid from the reactor in batches to the mixing system, stirring continuously for 3 hours to obtain a traditional resorcinol-formaldehyde-latex impregnation solution.

[0081] Comparative Example 2

[0082] To prepare the traditional resorcinol-formaldehyde-latex impregnation solution, an appropriate amount of deionized water was placed in a reaction vessel, and sodium hydroxide was added to prepare a 10% solution. An appropriate amount of resorcinol was then added to the reaction vessel, followed by formaldehyde. The temperature inside the vessel was maintained at 25°C, and the stirring speed was controlled at 360 rpm for 6 hours. After the reaction was complete, appropriate amounts of deionized water and styrene-butadiene latex were added to a mixing tank, and after thorough stirring, the liquid from the reaction vessel was added in batches to the mixing system, and stirring was continued for 1.5 hours to obtain the traditional resorcinol-formaldehyde-latex impregnation solution.

[0083] Performance test

[0084] The impregnation solutions obtained in Examples 1-7 were arbitrarily combined to obtain Application Examples 1-12. Then, the aramid cord was impregnated with the combined impregnation solutions of Application Examples 1-12 to obtain modified aramid cord. Finally, the H-type pull-out force between the modified aramid cord and the biomimetic synthetic rubber was further tested, and the results are shown in Table 1.

[0085] Table 1. Results of H-type pull-out force between modified aramid cord and biomimetic synthetic rubber in different application examples.

[0086]

[0087] Note: H-type pull-out force is a measure of the adhesive strength between aramid cord and rubber, which can be determined through the cord H-test.

[0088] Table 1 shows that the H-type pull-out force between the aramid cord modified with the impregnating solution of this invention and the biomimetic synthetic rubber reaches 181-236 N / cm. This novel impregnating solution has achieved a significant improvement in performance and successfully solves the problem of insufficient adhesive performance in traditional impregnating systems. The impregnating solution described in this invention not only meets the needs of most application scenarios, but its preparation process is also simple and easy, with relatively small environmental impact, and it has environmentally friendly characteristics. It can replace the traditional resorcinol-formaldehyde-latex type impregnating solution to a certain extent.

[0089] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An energy-saving and environmentally friendly aramid cord impregnation solution, characterized in that, This includes a pre-packaged first-bath impregnation solution and a second-bath impregnation solution; The raw materials of the one-bath impregnation solution, by weight, consist of 5-25 parts of blocked isocyanate, 2-15 parts of flexible multifunctional epoxy resin, and 100 parts of deionized water. The raw materials for the second bath impregnation solution consist of 50-250 parts latex, 5-25 parts phenolic resin, and 100 parts deionized water. The blocked isocyanate is prepared by end-capping isocyanate with a blocking agent, wherein the blocking agent is selected from one or more of oxime blocking agents, 2-hydroxypyridine, 5-chloro-2-hydroxypyridine, amine blocking agents, and imidazole blocking agents; The flexible multifunctional epoxy resin is selected from one or more of isosorbide-based epoxy resin, biophenol-based epoxy resin, rosin-based epoxy resin, and lignin-based epoxy resin. The latex is selected from one or more of the following: natural latex, styrene-butadiene latex, polybutadiene latex, butadiene-pyridine latex, carboxylated styrene-butadiene latex, and sulfonic acid-based polystyrene latex. The phenolic resin is made from cashew phenol, octylphenol, or dodecylphenol. The aldehyde used as the raw material for the phenolic resin is selected from furfural or pyridine-2-carboxaldehyde.

2. The energy-saving and environmentally friendly aramid cord impregnation solution according to claim 1, characterized in that, The isocyanate is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

3. The energy-saving and environmentally friendly aramid cord impregnation solution according to claim 1, characterized in that, The oxime blocking agent is selected from methyl ethyl ketone oxime; The amine blocking agent is selected from one or more of acetanilide, N-methylacetamide, and methacrylamide; The imidazole blocking agent is selected from one or more of 2-methylimidazole, 2-ethylimidazole, and 2-isopropylimidazole.

4. The energy-saving and environmentally friendly aramid cord impregnation solution according to claim 1, characterized in that, The isosorbide-based epoxy resin is selected from isosorbide-based glycidyl ether epoxy resin and diisosorbide-based glycidyl ether epoxy resin; The bio-phenolic epoxy resin is selected from one or more of eugenol-based epoxy resin, divanillol diglycidyl ether epoxy resin, divanillol triglycidyl ether epoxy resin, and divanillol tetraglycidyl ether epoxy resin.

5. The energy-saving and environmentally friendly aramid cord impregnation solution according to claim 1, characterized in that, The raw materials for the blocked isocyanate are selected from toluene diisocyanate and methyl ethyl ketone oxime; Alternatively, the raw material for the blocked isocyanate is selected from diphenylmethane diisocyanate and 2-hydroxypyridine; Alternatively, the raw materials for the blocked isocyanate are selected from hexamethylene diisocyanate and methacrylamide; Alternatively, the raw materials for the blocked isocyanate are selected from isophorone diisocyanate and 2-methylimidazole.

6. The energy-saving and environmentally friendly aramid cord impregnation solution according to claim 5, characterized in that, The flexible multifunctional epoxy resin is selected from isosorbide diglycidyl ether type epoxy resin, rosin-based epoxy resin, lignin-based epoxy resin, or divanillin diglycidyl ether epoxy resin.

7. The energy-saving and environmentally friendly aramid cord impregnation solution according to claim 6, characterized in that, The latex is selected from a mixture of butyl pyridine latex and carboxylated styrene-butadiene latex, a mixture of butyl pyridine latex and polybutadiene latex, or a mixture of carboxylated styrene-butadiene latex and polybutadiene latex.

8. A rubber material, characterized in that, Its raw materials include a rubber matrix and aramid cord treated with the energy-saving and environmentally friendly aramid cord impregnation solution as described in any one of claims 1 to 7.

9. The rubber material according to claim 8, characterized in that, The H-type pull-out force between the rubber matrix and the aramid cord in the rubber material is 181-236 N / cm.

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