Flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene material and preparation method of flexible yellowing-resistant bio-based polyurethane adhesive

Abstract

The invention provides a flexible yellowing-resistant bio-based polyurethane adhesive for a chlorosulfonated polyethylene material and a preparation method thereof, the flexible yellowing-resistant bio-based polyurethane adhesive is formed by mixing and curing a component A and a component B. The component A comprises an acrylic acid modified bio-based polyurethane prepolymer, a stabilizer, a water absorbent and a catalyst; and the component B is polyisocyanate or a polyisocyanate tripolymer. The preparation method of the acrylic acid modified bio-based polyurethane prepolymer comprises the following steps: mixing bio-based dihydric alcohol and isophorone diisocyanate to react, and curing to obtain a polyurethane prepolymer; and reacting the polyurethane prepolymer with an acrylic monomer in an organic solvent under the action of an initiator to obtain the acrylic modified bio-based polyurethane prepolymer. Then adding a stabilizer, a moisture scavenger and a catalyst into the acrylic acid modified bio-based polyurethane prepolymer, and uniformly mixing to obtain a component A; when the flexible yellowing-resistant bio-based polyurethane adhesive is used for bonding chlorosulfonated polyethylene with chlorosulfonated polyethylene or other resin films, textiles and other flexible materials, the peeling strength is high, the flexibility is good, yellowing resistance is achieved, and the flexible yellowing-resistant bio-based polyurethane adhesive is particularly suitable for surface protection of chlorosulfonated polyethylene serving as a main body material and bonding with other materials.

Description

Technical Field

[0001] The invention relates to the field of adhesives, and in particular to a flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials and a preparation method thereof. Background Art

[0002] Chlorosulfonated polyethylene is made from low-density polyethylene or high-density polyethylene through chlorination and chlorosulfonation reactions. It can dissolve in aromatic hydrocarbons and chlorinated hydrocarbons but not in fats and alcohols. It can only swell but not dissolve in ketones and ethers. It has excellent ozone resistance, atmospheric aging resistance, chemical corrosion resistance, etc., good physical and mechanical properties, aging resistance, heat resistance and low temperature resistance, oil resistance, flame resistance, wear resistance and electrical insulation resistance. Chlorosulfonated polyethylene resin is a white or yellow elastomer with the common properties of raw rubber. It is used in heavy-duty anti-corrosion coatings for outdoor metals such as automobiles, steel, and iron parts, special rubber products, hoses, tapes, rubber shoes, motorboat fenders, rail transit throughways, various rubber boats, etc.

[0003] Although chlorosulfonated polyethylene materials have many advantages, they are recognized as one of the difficult-to-bond materials due to their symmetrical structure, low surface energy, difficulty in diffusion between interfaces, and difficulty in bonding with other materials. In addition, when chlorosulfonated polyethylene materials are processed into products such as rail transit tunnels or rubber boats, chlorosulfonated polyethylene sheets are usually used for sewing. The seams and surfaces of the sheets need to be bonded to prevent water seepage and protection. They need to have good wear resistance and weather resistance, and require particularly good flexibility. At the same time, with the international community's high attention to low-carbon environmental protection, the development of bio-based adhesives has attracted great attention. Bio-based polyols are derived from plant oils such as castor oil and soybean oil. Bio-based polyols prepared by epoxidation and ring-opening hydroxylation have good hydrophobicity and structural stability, and can be modified with acrylic acid to improve the bonding strength with the interface. At present, there is a great demand for bonding and protective materials for chlorosulfonated polyethylene sheets, but there are no adhesive products with ideal performance.

[0004] The main research at home and abroad is the adhesive between fluoroplastics or fluororubber and metal. For example, Chemlok607 from LORD Corporation in the United States is a special adhesive commonly used for bonding silicone rubber, fluororubber and metal. The Chinese patent with publication number CN101307216A uses epoxy resin, sulfone polymer, curing agent and chloroform to prepare an epoxy resin adhesive for bonding fluororubber to metal. Summary of the invention

[0005] The invention relates to the field of adhesives, and in particular to a flexible, yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials and a preparation method thereof, which solves the problems of surface protection of chlorosulfonated polyethylene as a main material and adhesion to other materials, and has good flexibility, yellowing resistance and high bonding strength.

[0006] The technical solution of the present invention is as follows:

[0007] A flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials and a preparation method thereof, characterized in that it comprises two components A and B;

[0008] The component A is prepared by compounding 100 parts by weight of an acrylic acid-modified bio-based polyurethane prepolymer, 1 to 5 parts by weight of a stabilizer, 1 to 5 parts by weight of a water absorbent, and 0.05 to 0.5 parts by weight of a catalyst;

[0009] The component B is 3 to 15 parts by weight of a curing agent;

[0010] The preparation method of the acrylic modified bio-based polyurethane prepolymer is as follows: bio-based polyol and isophorone diisocyanate are mixed and reacted, and then ripened to obtain a polyurethane prepolymer; the molar ratio of the hydroxyl functional group in the bio-based polyol to the isocyanate functional group in the isophorone diisocyanate is (1.1-1.5):1;

[0011] The polyurethane prepolymer and the acrylic monomer are reacted in an organic solvent under the action of an initiator to obtain an acrylic acid-modified bio-based polyurethane prepolymer; the weight ratio of the polyurethane prepolymer, the acrylic monomer and the initiator is 10: (0.5-4): (0.02-0.1);

[0012] The curing agent of component B is polyisocyanate or polyisocyanate trimer;

[0013] The stabilizer is an antioxidant and an anti-ultraviolet agent;

[0014] The dehydrating agent is a liquid or solid dehydrating agent;

[0015] The catalyst is an organic metal catalyst or a tertiary amine catalyst;

[0016] The solid content of the acrylic acid-modified bio-based polyurethane prepolymer is 15-50%.

[0017] The bio-based polyol is a bio-based polyol prepared using vegetable oils such as castor oil or soybean oil as raw materials.

[0018] The acrylic monomer is one or more of acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide and glycidyl methacrylate.

[0019] The initiator is benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide or cyclohexanone peroxide.

[0020] The polyisocyanate is toluene diisocyanate, 4,4-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, isophorone diisocyanate or hexamethylene diisocyanate.

[0021] The stabilizer is one or a mixture of benzotriazole light stabilizers, salicylate light stabilizers, benzophenone light stabilizers, hindered amine light stabilizers, free radical chain blocking antioxidants and peroxide decomposition antioxidants.

[0022] The flexible, yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials is characterized in that the multi-dehydrating agent is a liquid dehydrating agent or a solid dehydrating agent, the liquid dehydrating agent is Additive OF or Additive TI, and the solid dehydrating agent is calcium oxide or molecular sieve.

[0023] The organic metal catalyst is one of dibutyltin dilaurate, stannous octoate and tetraisopropyl titanate; the tertiary amine catalyst is one of triethanolamine, triethylamine and triethylenetriamine.

[0024] A method for preparing the flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials according to any one of claims 1 to 9, comprising the following steps:

[0025] (A) mixing a bio-based polyol with isophorone diisocyanate for reaction, and then aging to obtain a bio-based polyurethane prepolymer; the molar ratio of the hydroxyl functional group in the bio-based polyol to the isocyanate functional group in the isophorone diisocyanate is (1.1-1.5):1;

[0026] (B) reacting the bio-based polyurethane prepolymer with an acrylic monomer in an organic solvent under the action of an initiator to obtain an acrylic acid-modified bio-based urethane prepolymer; the mass ratio of the bio-based polyurethane prepolymer, the acrylic monomer and the initiator is 10:(0.5-4):(0.02-0.1);

[0027] (C) reacting the bio-based polyurethane prepolymer with an acrylic monomer in an organic solvent under the action of an initiator to obtain an acrylic acid-modified bio-based urethane prepolymer; the mass ratio of the bio-based polyurethane prepolymer, the acrylic monomer and the initiator is 10:(0.5-4):(0.02-0.1);

[0028] (D) 3 to 15 parts of component B and component A prepared in step (C) are fully mixed and reacted, and then coated on the surface of the plasma-treated chlorosulfonated polyethylene material for bonding or surface protection of the chlorosulfonated polyethylene material.

[0029] The present invention belongs to a bio-based polyurethane two-component adhesive. During use, the isocyanate group in the curing agent and the carbamate group in the acrylic modified polyurethane prepolymer are cured and cross-linked to achieve bonding between the film and other materials, while meeting the requirements of solvent resistance, hydrolysis resistance, flexibility, friction resistance, yellowing resistance, bending resistance, etc. Due to the presence of acrylic acid or acrylate groups in the acrylic modified polyurethane prepolymer, the wettability of the adhesive on the surface of the chlorosulfonated polyethylene material can be increased, and the compatibility between the polyurethane and the chlorosulfonated polyethylene material can be improved, thereby improving the bonding strength.

[0030] At the same time, the present invention adopts bio-based polyols to improve the hydrophobicity of bio-based polyurethane prepolymers and enhance the adhesion to the base material. In addition, after the surface of the chlorosulfonated polyethylene material is treated with plasma, it is more conducive to enhancing the adhesion strength.

[0031] The experimental results show that the bio-based polyurethane adhesive of the present invention has high yellowing resistance, abrasion resistance and peel strength when used for bonding chlorosulfonated polyethylene material protection and flexible materials. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described in conjunction with specific embodiments below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The following embodiments are only used to illustrate the present invention and are not used to limit the scope of protection of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] Example

[0035] Example 1

[0036] 100 parts of bio-based polyol derived from castor oil were added to the reactor and heated to 90±5°C. Stirring was carried out under nitrogen protection, and 10 parts of isophorone diisocyanate were added during stirring. After the sample reacted for 6 hours, it was poured into a container, placed in an oven at 100°C for aging for 8 hours, and cooled to room temperature to obtain a bio-based polyurethane prepolymer.

[0037] Add 10 parts of bio-based polyurethane prepolymer to 30 parts of ethyl acetate and slowly stir at 80°C. After the polyurethane prepolymer is completely dissolved, add a mixed solution of 1 part of methyl methacrylate, 1 part of butyl acrylate and 0.04 part of benzoyl peroxide dropwise under nitrogen protection while stirring. After reacting for 8 hours, an acrylic acid-modified bio-based polyurethane prepolymer is obtained.

[0038] 100 parts of the acrylic acid-modified bio-based polyurethane prepolymer prepared above and 0.2 parts of dibutyltin dilaurate were stirred to be evenly mixed, so as to prepare the bio-based polyurethane adhesive component A for chlorosulfonated polyethylene rubber sheet.

[0039] 5 parts of isophorone diisocyanate trimer were used as adhesive component B. Component B and the above-prepared component A were fully mixed and then applied to the bonding between plasma surface-treated chlorosulfonated polyethylene rubber plates. After aging, the peel strength was 8.2 N / cm.

[0040] Example 2

[0041] 100 parts of bio-based polyol derived from castor oil were added to the reactor and heated to 90±5°C. Stirring was carried out under nitrogen protection, and 10 parts of isophorone diisocyanate were added during stirring. After the sample reacted for 6 hours, it was poured into a container, placed in an oven at 100°C for aging for 8 hours, and cooled to room temperature to obtain a bio-based polyurethane prepolymer.

[0042] Add 10 parts of bio-based polyurethane prepolymer to 30 parts of ethyl acetate and slowly stir at 80°C. After the polyurethane prepolymer is completely dissolved, add a mixed solution of 1 part of methyl methacrylate, 1 part of butyl acrylate and 0.04 part of benzoyl peroxide dropwise under nitrogen protection while stirring. After reacting for 8 hours, an acrylic acid-modified bio-based polyurethane prepolymer is obtained.

[0043] 100 parts of the acrylic acid-modified bio-based polyurethane prepolymer prepared above and 0.3 parts of dibutyltin dilaurate were stirred to be evenly mixed, so as to prepare the bio-based polyurethane adhesive component A for chlorosulfonated polyethylene rubber sheet.

[0044] 7 parts of polymethylene polyphenyl polyisocyanate PM-200 were used as adhesive component B. Component B and the above-prepared component A were fully mixed and then applied to the bonding between plasma surface-treated chlorosulfonated polyethylene rubber plates. After aging, the peel strength was 8.6 N / cm.

[0045] Example 3

[0046] 100 parts of soybean oil-derived bio-based polyol were added to the reactor and heated to 90±5°C. The mixture was stirred under nitrogen protection, and 10 parts of isophorone diisocyanate were added during the stirring process. After the sample reacted for 6 hours, it was poured into a container, placed in an oven at 100°C for aging for 8 hours, and cooled to room temperature to obtain a bio-based polyurethane prepolymer.

[0047] 10 parts of bio-based polyurethane prepolymer were added into a mixed solvent of 40 parts of ethyl acetate and butanone (mixing ratio: ethyl acetate to butanone was 1:1), and slowly stirred at 80°C. After the bio-based polyurethane prepolymer was completely dissolved, a mixed solution of 0.5 parts of methyl methacrylate, 0.5 parts of 2-hydroxyethyl acrylate and 0.02 parts of benzoyl peroxide was reacted for 7 hours under nitrogen protection to obtain an acrylic acid-modified bio-based polyurethane prepolymer.

[0048] 100 parts of the acrylic acid-modified bio-based polyurethane prepolymer prepared above and 0.2 parts of dibutyltin dilaurate were slowly stirred to be evenly mixed, so as to prepare the polyurethane adhesive component A for chlorosulfonated polyethylene rubber sheet.

[0049] 6 parts of isophorone diisocyanate trimer were used as adhesive component B. Component B and the above-prepared component A were fully mixed and then applied to the bonding between plasma surface-treated chlorosulfonated polyethylene rubber sheets. After aging, the peel strength was 8.5 N / cm.

[0050] The above embodiments are only used to help understand the product, method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0051] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials and a preparation method thereof, characterized in that: It includes two components, A and B; The component A is compounded from 100 parts by weight of an acrylic acid-modified bio-based polyurethane prepolymer, 1 to 5 parts by weight of a stabilizer, 1 to 5 parts by weight of a water absorbent, and 0.05 to 0.5 parts by weight of a catalyst; The component B is 3 to 15 parts by weight of a curing agent; The preparation method of the acrylic modified bio-based polyurethane prepolymer is as follows: bio-based polyol and isophorone diisocyanate are mixed and reacted, and then ripened to obtain a polyurethane prepolymer; the molar ratio of the hydroxyl functional group in the bio-based polyol to the isocyanate functional group in the isophorone diisocyanate is (1.1-1.5):1; The polyurethane prepolymer and the acrylic monomer are reacted in an organic solvent under the action of an initiator to obtain an acrylic acid-modified bio-based polyurethane prepolymer; the weight ratio of the polyurethane prepolymer, the acrylic monomer and the initiator is 10: (0.5-4): (0.02-0.1); The stabilizer is an antioxidant and an anti-ultraviolet agent; The dehydrating agent is a liquid or solid dehydrating agent; The catalyst is an organic metal catalyst or a tertiary amine catalyst; The curing agent of the component B is polyisocyanate or polyisocyanate trimer.

2. The flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials according to claim 1, characterized in that: The solid content of the acrylic acid-modified bio-based polyurethane prepolymer is 15-50%.

3. The flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials according to claim 1, characterized in that: The bio-based polyol is a bio-based polyol prepared using vegetable oils such as castor oil or soybean oil as raw materials.

4. The flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials according to claim 1, characterized in that: The acrylic monomer is one or more of acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide and glycidyl methacrylate.

5. The flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials according to claim 1, characterized in that: The initiator is benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide or cyclohexanone peroxide.

6. The flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials according to claim 1, characterized in that: The curing agent polyisocyanate is toluene diisocyanate, 4,4-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, isophorone diisocyanate or hexamethylene diisocyanate.

7. The flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials according to claim 1, characterized in that: The stabilizer is one or a mixture of benzotriazole light stabilizers, salicylate light stabilizers, benzophenone light stabilizers, hindered amine light stabilizers, free radical chain blocking antioxidants and peroxide decomposition antioxidants.

8. The flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials according to claim 1, characterized in that: The multi-dehydrating agent is a liquid dehydrating agent or a solid dehydrating agent, the liquid dehydrating agent is Additive OF or Additive TI, and the solid dehydrating agent is calcium oxide or molecular sieve.

9. The flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials according to claim 1, characterized in that: The organic metal catalyst is one of dibutyltin dilaurate, stannous octoate and tetraisopropyl titanate; the tertiary amine catalyst is one of triethanolamine, triethylamine and triethylenetriamine.

10. A method for preparing the flexible yellowing-resistant bio-based polyurethane adhesive for chlorosulfonated polyethylene materials according to any one of claims 1 to 9, characterized in that The steps include: The bio-based polyol and isophorone diisocyanate are mixed and reacted, and then aged to obtain a bio-based polyurethane prepolymer; the molar ratio of the hydroxyl functional group in the bio-based polyol to the isocyanate functional group in the isophorone diisocyanate is (1.1-1.5):1; The bio-based polyurethane prepolymer and the acrylic monomer are reacted in an organic solvent under the action of an initiator to obtain an acrylic acid-modified bio-based urethane prepolymer; the mass ratio of the bio-based polyurethane prepolymer, the acrylic monomer and the initiator is 10: (0.5-4): (0.02-0.1); 100 parts by weight of the acrylic acid-modified bio-based polyurethane prepolymer, 1 to 5 parts by weight of a stabilizer, 1 to 5 parts by weight of a dehydrating agent, and 0.05 to 0.5 parts by weight of a catalyst are uniformly mixed to obtain a component A; 3 to 15 parts of component B and component A prepared in step (C) are fully mixed and reacted, and then coated on the surface of the chlorosulfonated polyethylene material treated with plasma, for bonding or surface protection of the chlorosulfonated polyethylene material.