Preparation method of heat-resistant and water-resistant two-component polyurethane solvent adhesive

Abstract

This invention belongs to the field of polyurethane solvates and relates to a method for preparing a heat- and water-resistant two-component polyurethane solvate. The method includes: obtaining an epoxy resin with hydroxyl groups protected by silyl ether bonds through a hydroxyl protection reaction between TBS and epoxy resin; preparing a prepolymer of component A of the polyurethane solvate in a solvent; adding the obtained epoxy resin as a partial chain extender to the prepolymer of component A of the polyurethane solvate to react and obtain an epoxy resin-modified polyurethane adhesive; adding methyltrichlorosilane (TMSCl) to the modified polyurethane solvate to protect the hydroxyl groups on the epoxy resin, obtaining a hydroxyl-modified epoxy resin-modified polyurethane solvate component A; and mixing component A with component B (curing agent) for use. The resulting polyurethane solvate exhibits significantly improved heat and water resistance and can be applied in industries such as automotive and water sports.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane solvates, and specifically relates to a method for preparing a heat-resistant and water-resistant two-component polyurethane solvate. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Polyurethane solvent adhesives, due to the presence of urethane ester bonds and other components, exhibit high polarity and excellent adhesion strength to substrates such as PVC. Furthermore, their excellent flowability and permeability allow them to form strong physical bonds with substrates such as fabrics. In addition, their application process is simple, making them widely used in footwear, clothing, automobiles, and sporting goods, and they are irreplaceable by general materials.

[0004] However, due to the poor heat resistance of polyurethane matrix, a curing agent is usually added during use to slowly form a cross-linked network structure, thereby increasing its bonding strength and heat resistance. In addition, its structure contains a lot of ester bonds, which makes it easy to hydrolyze and has poor water resistance. The heat resistance and water resistance limit its application in some aspects. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing a heat- and water-resistant two-component polyurethane solvent adhesive. The resulting polyurethane solvent adhesive exhibits significantly improved heat and water resistance, making it suitable for applications in industries such as automobiles and water sports equipment.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing a heat- and water-resistant two-component polyurethane solvate, comprising:

[0008] Epoxy resin was mixed with imidazole and methyltrichlorosilane TMSCl in a solvent and subjected to a hydroxyl protection reaction to obtain an epoxy resin in which the hydroxyl groups were protected by silyl ether bonds.

[0009] Polyol and isocyanate are mixed evenly in a solvent, and chain extender and catalyst are added in sequence to carry out prepolymerization to obtain the A component prepolymer of polyurethane solvent adhesive;

[0010] The epoxy resin with hydroxyl groups protected by siloxane bonds is mixed with the A component prepolymer of polyurethane solvate and subjected to a chain extension reaction to obtain epoxy resin modified and siloxane modified polyurethane solvate component A.

[0011] The epoxy resin modified and siloxane modified polyurethane solvate component A is mixed with a tetrabutylammonium fluoride THF solution and reacted to obtain hydroxyl modified and epoxy resin modified polyurethane solvate component A.

[0012] The A and B components of the hydroxyl-modified epoxy resin-modified polyurethane solvent adhesive are placed separately and then mixed before use to obtain the final product.

[0013] The mass ratio of epoxy resin, imidazole, and methyltrichlorosilane is 3~6:0.4-1:0.7-1.7.

[0014] Component B is a curing agent.

[0015] In a second aspect, the present invention provides a heat- and water-resistant two-component polyurethane solvate prepared by the above method.

[0016] A third aspect of the present invention provides the application of the above-described heat- and water-resistant two-component polyurethane solvent adhesive in the manufacture of footwear, clothing, automobiles, and (water) sporting goods.

[0017] Beneficial effects of the present invention

[0018] (1) This invention uses the reaction of epoxy resin and isocyanate to give the polyurethane hard segments an oxazolidinone structure, which can effectively improve the heat resistance of the polyurethane adhesive matrix. By protecting and deprotecting the hydroxyl groups of epoxy resin, the matrix can obtain hydroxyl active groups. After the addition of the curing agent, the cross-linking curing rate can be effectively improved, and its heat and water resistance can be effectively improved. After testing, the two-component polyurethane solvent adhesive significantly improves the hydrolysis resistance of the adhesive tape. After 7 days in a 100-degree water bath, the peel strength retention rate can reach 85%.

[0019] (2) The operation method of this application is simple, low-cost, universal, and easy to scale up production. Detailed Implementation

[0020] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] A method for preparing a heat- and water-resistant two-component polyurethane solvent adhesive includes the following steps:

[0022] (1) Dissolve 3-6 g of epoxy resin in dry DMF (20 mL). Add 0.4-1 g of imidazole to the solution at 0 °C, and then add 0.7-1.7 g of methyltrichlorosilane (TMSCl). After stirring at 0 °C for 1.5 hours, dilute with ethyl acetate (100 mL) to obtain the reaction mixture.

[0023] (2) Add 100-150g of polyol and 15-20g of isocyanate to 600ml of butanone, stir at 50 degrees for 60min, then add 1-3g of chain extender and 0.001-0.1g of catalyst, stir at 50 degrees for 30min to obtain the A component prepolymer of polyurethane solvent adhesive.

[0024] (3) Add the siloxane-modified epoxy resin mixture obtained in step one to the prepolymer of component A in step two, and stir for 30 min to allow the epoxy resin to participate in the chain extension reaction of polyurethane. Epoxy resin-modified, siloxane-modified polyurethane solvent adhesive component A is obtained.

[0025] (4) Add 150 ml of tetrabutylammonium fluoride THF solution (0.05-1 mol / L) to component A in step 3, stir at 20 degrees and react for 20 h to obtain component A of hydroxyl-modified epoxy resin modified polyurethane solvent adhesive.

[0026] (5) When using, mix 10-100g of component B (polymeric isocyanate curing agent) with component A evenly before use.

[0027] In some embodiments, in step (1), the epoxy resin is one or a mixture of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin.

[0028] In some embodiments, in step (2), the polyol is one or more of polyester-based diol, polycaprolactone-based diol, polycarbonate-based diol, and polyether-based diol, with a number-average molecular weight of 300-4000; the chain extender is one or two of ethylene glycol, butanediol, and hexanediol. The diisocyanate is at least one of MDI, HDI, IPDI, and TDI.

[0029] In some embodiments, in step (5), the curing agent includes one or more of polymeric MDI, polymeric HDI, polymeric TDI, and polymeric IPDI, and is used in an amount of 10-100 parts by weight.

[0030] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0031] Example 1:

[0032] (1) Dissolve 3g of bisphenol A type epoxy resin in dry DMF (20 mL). Add 0.6g of imidazole to the solution at 0℃, and then add 1.0g of TMSCl. After stirring at 0℃ for 1.5 hours, dilute with ethyl acetate (100 mL) to obtain the reaction mixture.

[0033] (2) Add 120g of polybutylene adipate diol (molecular weight 3000) and 16g of isocyanate to 600ml of butanone, stir at 50 degrees for 60min, then add 1.6g of chain extender 1,4-butanediol and 0.005g of catalyst dibutyltin dilaurate, stir at 50 degrees for 30min to obtain the A component prepolymer of polyurethane solvent adhesive.

[0034] (3) Add the siloxane-modified epoxy resin mixture obtained in step one to the prepolymer of component A in step two, and stir for 30 min to allow the epoxy resin to participate in the chain extension reaction of polyurethane. Epoxy resin-modified, siloxane-modified polyurethane solvent adhesive component A is obtained.

[0035] (4) Add 150 ml of tetrabutylammonium fluoride THF solution (1 mol / L) to component A in step 3, stir at 20 degrees and react for 20 h to obtain component A of hydroxyl-modified epoxy resin modified polyurethane solvent adhesive.

[0036] (5) When using, mix 35 parts of component B (polymeric isocyanate curing agent poly MDI PM200) with component A evenly, apply the adhesive to both sides of the polyester fabric, adhere at 80 degrees for 3 minutes, cure at 50 degrees for 24 hours, and place the sample in a 100-degree water bath for 7 days. The peel strength retention rate can reach 75%.

[0037] Example 2:

[0038] (1) Dissolve 3g of bisphenol A type epoxy resin in dry DMF (20 mL). Add 0.7g of imidazole to the solution at 0℃, and then add 1.2g of TMSCl. After stirring at 0℃ for 1.5 hours, dilute with ethyl acetate (100 mL) to obtain the reaction mixture.

[0039] (2) Add 120g of polybutylene adipate diol (molecular weight 3000) and 16g of isocyanate to 600ml of butanone, stir at 50 degrees for 60min, then add 1.61g of chain extender 1,4-butanediol and 0.005g of catalyst dibutyltin dilaurate, stir at 50 degrees for 30min to obtain the A component prepolymer of polyurethane solvent adhesive.

[0040] (3) Add the siloxane-modified epoxy resin mixture obtained in step one to the prepolymer of component A in step two, and stir for 30 min to allow the epoxy resin to participate in the chain extension reaction of polyurethane. Epoxy resin-modified, siloxane-modified polyurethane solvent adhesive component A is obtained.

[0041] (4) Add 150 ml of tetrabutylammonium fluoride THF solution (1 mol / L) to component A in step 3, stir at 20 degrees and react for 20 h to obtain component A of hydroxyl-modified epoxy resin modified polyurethane solvent adhesive.

[0042] (5) When using, mix 35 parts of component B (polymeric isocyanate curing agent poly MDI PM200) with component A evenly, apply the adhesive to both sides of the polyester fabric, adhere at 80 degrees for 3 minutes, cure at 50 degrees for 24 hours, and place the sample in a 100-degree water bath for 7 days. The peel strength retention rate can reach 79%.

[0043] Example 3:

[0044] (1) Dissolve 4g of bisphenol A type epoxy resin in dry DMF (20 mL). Add 0.9g of imidazole to the solution at 0℃, and then add 1.6g of TMSCl. After stirring at 0℃ for 1.5 hours, dilute with ethyl acetate (100 mL) to obtain the reaction mixture.

[0045] (2) Add 120g of polybutylene adipate diol (molecular weight 3000) and 16g of isocyanate to 600ml of butanone, stir at 50 degrees for 60min, then add 1.3g of chain extender 1,4-butanediol and 0.005g of catalyst dibutyltin dilaurate, stir at 50 degrees for 30min to obtain the A component prepolymer of polyurethane solvent adhesive.

[0046] (3) Add the siloxane-modified epoxy resin mixture obtained in step one to the prepolymer of component A in step two, and stir for 30 min to allow the epoxy resin to participate in the chain extension reaction of polyurethane. Epoxy resin-modified, siloxane-modified polyurethane solvent adhesive component A is obtained.

[0047] (4) Add 150 ml of tetrabutylammonium fluoride THF solution (1 mol / L) to component A in step 3, stir at 20 degrees and react for 20 h to obtain component A of hydroxyl-modified epoxy resin modified polyurethane solvent adhesive.

[0048] (5) When using, mix 35 parts of component B (polymeric isocyanate curing agent poly MDI PM200) with component A evenly, apply adhesive to both sides of polyester fabric, adhere at 80 degrees for 3 minutes, cure at 50 degrees for 24 hours, and place the sample in a 100-degree water bath for 7 days. The peel strength retention rate can reach 82%.

[0049] Example 4:

[0050] (1) Dissolve 4g of bisphenol A type epoxy resin in dry DMF (20 mL). Add 0.9g of imidazole to the solution at 0℃, and then add 1.6g of TMSCl. After stirring at 0℃ for 1.5 hours, dilute with ethyl acetate (100 mL) to obtain the reaction mixture.

[0051] (2) Add 120g of polybutylene adipate diol (molecular weight 3000) and 16g of isocyanate to 600ml of butanone, stir at 50 degrees for 60min, then add 1.3g of chain extender 1,4-butanediol and 0.005g of catalyst dibutyltin dilaurate, stir at 50 degrees for 30min to obtain the A component prepolymer of polyurethane solvent adhesive.

[0052] (3) Add the siloxane-modified epoxy resin mixture obtained in step one to the prepolymer of component A in step two, and stir for 30 min to allow the epoxy resin to participate in the chain extension reaction of polyurethane. Epoxy resin-modified, siloxane-modified polyurethane solvent adhesive component A is obtained.

[0053] (4) Add 150 ml of tetrabutylammonium fluoride THF solution (1 mol / L) to component A in step 3, stir at 20 degrees and react for 20 h to obtain component A of hydroxyl-modified epoxy resin modified polyurethane solvent adhesive.

[0054] (5) When using, mix 40 parts of component B (polymeric isocyanate curing agent poly MDI PM200) with component A evenly, apply the adhesive to both sides of the polyester fabric, adhere at 80 degrees for 3 minutes, cure at 50 degrees for 24 hours, and place the sample in a 100-degree water bath for 7 days. The peel strength retention rate can reach 85%.

[0055] Comparative Example 1:

[0056] (1) Add 120g of polybutylene adipate diol (molecular weight 3000) and 16g of isocyanate to 600ml of butanone, stir at 50 degrees for 60min, then add 1.23g of chain extender 1,4-butanediol and 0.005g of catalyst dibutyltin dilaurate, stir at 50 degrees for 30min to obtain the A component prepolymer of polyurethane solvent adhesive.

[0057] (2) Add 0.9g of chain extender 1,4-butanediol to the prepolymer of component A in step one and stir for 30min. The polyurethane solvent adhesive component A is obtained.

[0058] (3) Mix 40 parts of component B (polymeric isocyanate curing agent poly MDI PM200) with component A evenly, apply adhesive to both sides of polyester fabric, bond at 80 degrees for 3 minutes, cure at 50 degrees for 24 hours, place the sample in a 100-degree water bath for 7 days, and test the peel strength retention rate of 57%.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a heat-resistant and water-resistant two-component polyurethane solvent adhesive, characterized in that, include; Epoxy resin was mixed with imidazole and trimethylchlorosilane (TMSCl) in a solvent and subjected to a hydroxyl protection reaction to obtain an epoxy resin in which the hydroxyl groups were protected by silyl ether bonds. Polyol and isocyanate are mixed evenly in a solvent, and chain extender and catalyst are added in sequence to carry out prepolymerization to obtain the A component prepolymer of polyurethane solvent adhesive; The epoxy resin with hydroxyl groups protected by siloxane bonds is mixed with the A component prepolymer of polyurethane solvate and subjected to a chain extension reaction to obtain epoxy resin modified and siloxane modified polyurethane solvate component A. The epoxy resin modified and siloxane modified polyurethane solvate component A is mixed with a tetrabutylammonium fluoride THF solution and reacted to obtain hydroxyl modified and epoxy resin modified polyurethane solvate component A. The A and B components of the hydroxyl-modified epoxy resin-modified polyurethane solvent adhesive are placed separately and then mixed before use to obtain the final product. The mass ratio of epoxy resin, imidazole, and trimethylchlorosilane is 3~6:0.4-1:0.7-1.

7. Component B is the curing agent; The epoxy resin is at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin; The mass ratio of the polyol, isocyanate, chain extender, and catalyst is 100-150:15-20:1-3:0.001-0.1; The polyol is at least one of polyester-based diol, polycarbonate-based diol, and polyether-based diol, with a number-average molecular weight of 300-4000. The isocyanate is at least one of MDI, HDI, IPDI, and TDI.

2. The preparation method of the heat-resistant and water-resistant two-component polyurethane solvent adhesive as described in claim 1, characterized in that, The epoxy resin, imidazole, and trimethylchlorosilane (TMSCl) were stirred at 0-0.5°C for 1.5-2 hours.

3. The method for preparing the heat-resistant and water-resistant two-component polyurethane solvent adhesive as described in claim 1, characterized in that, The polyester-based diol includes polycaprolactone-based diol.

4. The preparation method of the heat-resistant and water-resistant two-component polyurethane solvent adhesive as described in claim 1, characterized in that, The chain extender is one or two of ethylene glycol, butanediol, and hexanediol.

5. The method for preparing the heat-resistant and water-resistant two-component polyurethane solvent adhesive as described in claim 1, characterized in that, The curing agent includes one or more of polymeric MDI, polymeric HDI, polymeric TDI, and polymeric IPDI, and is used in an amount of 10-100 parts by weight.

6. The heat-resistant and water-resistant two-component polyurethane solvent adhesive prepared by the method according to any one of claims 1-5.

7. The application of the heat-resistant and water-resistant two-component polyurethane solvent adhesive according to claim 6 in the manufacture of footwear, clothing, automobiles, and sporting goods.