EB curing glue for artificial leather

Abstract

The present invention relates to the technical field of adhesives, particularly to an artificial leather EB curing glue, which comprises the following raw material components by weight: 40-70 parts of cyclic carbonate-containing modified acrylate; 20 to 40 parts of polyurethane modified acrylate; 3-5 parts of a silane coupling agent; 10 to 20 parts of an active monomer; 0.3 part of a leveling agent; and 0.3 part of a defoaming agent. The EB curing glue for artificial leather provided by the invention can be cured by adopting an EB mode, so that the use of a solvent is reduced, the pollution is reduced, the process is simplified, the energy consumption is reduced, and the efficiency is improved; meanwhile, cyclic carbonate is introduced into a system through modified acrylate, so that the aging resistance of an EB glue coating is greatly improved, and the service life of leather is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, in particular to EB curing glue for artificial leather. Background Art

[0002] Artificial leather has a wide range of applications. Its traditional production process is to apply a thermosetting leather-like coating on a patterned release paper, apply a solvent-based adhesive on it after curing, and then laminate it with a substrate such as non-woven fabric, and put it into a baking oven to dry and cure the solvent.

[0003] This process is not only inefficient and energy-intensive, but the solvent-based adhesive used in it also has poor aging resistance, resulting in a shorter service life of the leather. Summary of the invention

[0004] In order to solve the problem that the solvent-based adhesive used for artificial leather in the prior art has poor aging resistance, the present invention provides an EB-cured glue for artificial leather. The EB-cured glue introduces cyclic carbonate into the system through modified acrylate to improve the aging resistance of the adhesive layer, thereby solving the problem that the solvent-based adhesive used for artificial leather in the prior art has poor aging resistance.

[0005] The technical solution adopted by the present invention to solve its technical problem is: An EB curing glue for artificial leather, the raw materials include the following components in parts by weight: 40-70 parts of modified acrylate containing cyclic carbonate; Polyurethane modified acrylate 20-40 parts; Silane coupling agent KH570 3~5 parts; 10-20 parts of active monomer; 0.3 parts of leveling agent; 0.3 parts of defoaming agent.

[0006] Optionally, the modified acrylate containing cyclic carbonate is prepared according to the following method: S1: mixing glycidyl methacrylate, methoxylated acrylic acid cyclocarbonate, N-hydroxyethyl acrylamide, methacrylic acid, azobisisobutyronitrile and dioxane to obtain a reaction mixture; S2: After deoxygenating the reaction mixture, stirring and reacting at 60-80° C. to obtain a precipitated product; S3: The precipitated product, catalyst p-toluenesulfonic acid, hydroquinone and xylene are mixed, the temperature is raised to 60-80° C., hydroxyethyl acrylate is added dropwise while stirring, and the reaction is monitored by FTIR measurement. After the absorption peak of the carboxyl group in the reactant disappears, the addition of hydroxyethyl acrylate is stopped, the reaction is terminated, and the modified acrylate containing cyclic carbonate is obtained.

[0007] Optionally, in step S1, the molar ratio of the glycidyl methacrylate, the methoxylated acrylic cyclic carbonate, the N-hydroxyethyl acrylamide, and the methacrylic acid is 1:3:3:1.

[0008] Optionally, the weight of the azobisisobutyronitrile in step S1 is 0.5% of the total weight of the glycidyl methacrylate, the methoxylated acrylic acid cyclocarbonate, the N-hydroxyethyl acrylamide, and the methacrylic acid.

[0009] Optionally, in step S3, the mass ratio of the precipitated product, the catalyst p-toluenesulfonic acid, and the hydroquinone is (7-8): 0.01: 0.001.

[0010] Optionally, in step S3, the mass volume ratio of the precipitated product to the xylene is 1 g: (1-3) mL.

[0011] Optionally, the polyurethane-modified acrylate is a difunctional polyurethane-modified acrylate.

[0012] Optionally, the active monomer is selected from at least one of 1,6-ethylene glycol diacrylate and tripropylene glycol diacrylate.

[0013] Optionally, the leveling agent is an acrylic leveling agent.

[0014] Optionally, the defoamer is a silicone defoamer or a polyether defoamer.

[0015] The beneficial effects of the present invention are: The EB curing glue for artificial leather provided by the present invention can be cured in an EB manner, which not only reduces the use of solvents and reduces pollution, but also simplifies the process, reduces energy consumption and improves efficiency; at the same time, cyclic carbonate is introduced into the system through modified acrylate, which greatly improves the aging resistance of the EB glue coating and helps to extend the service life of the leather. DETAILED DESCRIPTION

[0016] The present invention is now further described in detail. The embodiments described below are exemplary and intended to be used to explain the present invention, but cannot be understood as limiting the present invention. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0017] In order to solve the problem that the solvent-based adhesive used for artificial leather in the prior art has poor aging resistance, the present invention provides an EB curing glue for artificial leather. The raw materials include the following components in parts by weight: 40-70 parts of modified acrylate containing cyclic carbonate; Polyurethane modified acrylate 20-40 parts; Silane coupling agent KH570 3~5 parts; 10-20 parts of active monomer; 0.3 parts of leveling agent; 0.3 parts of defoaming agent.

[0018] Existing UV adhesives have excellent bonding properties and aging resistance, but because the imitation leather layer and the base layer are not transparent and cannot be cured, they cannot be applied to artificial leather. The EB curing glue for artificial leather provided by the present invention can penetrate the imitation leather layer and the base layer to perform radiation curing, which is green, environmentally friendly, efficient and low in energy consumption.

[0019] The EB curing glue for artificial leather provided by the present invention can be cured in an EB manner, which not only reduces the use of solvents and reduces pollution, but also simplifies the process, reduces energy consumption and improves efficiency; at the same time, cyclic carbonate is introduced into the system through modified acrylate, which greatly improves the aging resistance of the EB glue coating and helps to extend the service life of the leather.

[0020] Specifically, the present invention preferably prepares the modified acrylate containing cyclic carbonate according to the following method: S1: Glycidyl methacrylate (GMA), methoxylated acrylic acid cyclocarbonate, N-hydroxyethyl acrylamide, methacrylic acid, azobisisobutyronitrile and dioxane are mixed to obtain a reaction mixture; S2: After deoxygenating the reaction mixture, stirring the reaction at 60-80° C., preferably 70° C., preferably stirring the reaction for 24 hours to obtain a precipitated product; S3: Mix the precipitated product, catalyst p-toluenesulfonic acid, hydroquinone and xylene, raise the temperature to 60-80°C, preferably to 70°C, add hydroxyethyl acrylate dropwise while stirring, monitor the reaction by FTIR measurement, and stop adding hydroxyethyl acrylate after the absorption peak of the carboxyl group in the reactant disappears, the reaction is terminated, and a modified acrylate containing cyclic carbonate is obtained.

[0021] The modified acrylic ester prepared by the method introduces cyclocarbonate, hydroxyl group and acrylamide, thereby improving the aging resistance of the coating while helping to improve the adhesion between the rubber layer and the imitation leather layer and the base layer, further extending the service life of the leather.

[0022] In order to take into account both the aging resistance and adhesion of the coating, the molar ratio of glycidyl methacrylate, methoxylated acrylic acid cyclocarbonate, N-hydroxyethyl acrylamide, and methacrylic acid in step S1 is preferably 1:3:3:1; the weight of azobisisobutyronitrile in step S1 is preferably 0.5% of the total weight of glycidyl methacrylate, methoxylated acrylic acid cyclocarbonate, N-hydroxyethyl acrylamide, and methacrylic acid; The mass ratio of the precipitated product, the catalyst p-toluenesulfonic acid, and the hydroquinone in step S3 is (7-8):0.01:0.001, and is further preferably 7.04:0.01:0.001; the mass volume ratio of the precipitated product to xylene in step S3 is preferably 1 mg:(1-3) mL.

[0023] In the present invention, the polyurethane modified acrylate is preferably a bifunctional polyurethane modified acrylate, so as to avoid excessively high functionality leading to brittle cracking of the paint film and excessively low functionality leading to insufficient strength of the reaction cross-linking network; further preferably, the polyurethane modified acrylate is selected from at least one of Changxing ETERCURE 6148J-75, Changxing ETERCURE DR-U079, and Changxing ETERCURE H518).

[0024] The present invention improves the adhesion of the glue by introducing the silane coupling agent KH570; the silane coupling agent KH570 is further preferably KH570 produced by Guangzhou Shuangtao Fine Chemical Co., Ltd.

[0025] In the present invention, the active monomer is preferably selected from at least one of 1,6-ethylene glycol diacrylate and tripropylene glycol diacrylate.

[0026] The invention uses the synergistic effect of self-made modified acrylate containing cyclic carbonate, polyurethane modified acrylate, silane coupling agent KH570 and active monomers, and combines EB curing, so that the EB curing glue can be suitable for artificial leather, and when applied to artificial leather, the obtained glue coating can have excellent adhesion, bonding and aging resistance.

[0027] The preferred leveling agent of the present invention is an acrylic leveling agent, and the more preferred leveling agent is BYK361N; the preferred defoaming agent is an organic silicon defoaming agent or a polyether defoaming agent, and the more preferred defoaming agent is BYK-022.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below.

[0029] Unless otherwise specified, the silane coupling agent KH570 in the embodiments and comparative examples of the present invention is KH570 produced by Guangzhou Shuangtao Fine Chemical Co., Ltd.; the leveling agent is BYK361N; and the defoaming agent is BYK-022.

[0030] Unless otherwise specified, the modified acrylate containing cyclic carbonate in each embodiment of the present invention and the comparative example is prepared according to the following method: S1: Weigh glycidyl methacrylate (GMA), methoxylated acrylic acid cyclocarbonate (CL-1042 from SNPE), N-hydroxyethyl acrylamide, methacrylic acid, azobisisobutyronitrile and dioxane in a round-bottom flask and mix them to obtain a reaction mixture; wherein the molar ratio of glycidyl methacrylate, methoxylated acrylic acid cyclocarbonate, N-hydroxyethyl acrylamide and methacrylic acid is 1:3:3:1; the weight of azobisisobutyronitrile is 0.5% of the total weight of glycidyl methacrylate, methoxylated acrylic acid cyclocarbonate, N-hydroxyethyl acrylamide and methacrylic acid; the mass ratio of methacrylic acid to dioxane is 1:6; S2: After the reaction mixture is filled with nitrogen to deoxygenate, the round-bottom flask is stirred at 70° C. for 24 hours. After the reaction is completed, the product is washed and vacuum dried at 45° C. to obtain a precipitated product; S3: Add 7.04 g of precipitated product, 0.01 g of catalyst p-toluenesulfonic acid, 0.001 g of hydroquinone, and 20 mL of xylene into a three-hole round-bottom flask, mix, heat to 70°C, add hydroxyethyl acrylate dropwise while stirring, monitor the reaction by FTIR measurement, stop adding hydroxyethyl acrylate after the absorption peak of the carboxyl group in the reactant disappears, the reaction is terminated, and a modified acrylate containing cyclic carbonate is obtained.

[0031] Example 1 This embodiment provides an EB curing glue for artificial leather, and the raw materials include the following components in parts by weight: 50 parts of modified acrylate containing cyclic carbonate; 30 parts of polyurethane modified acrylate; Silane coupling agent KH570 4 parts; 1,6-ethylene glycol diacrylate 15 parts; 0.3 parts of leveling agent; 0.3 parts of defoaming agent.

[0032] The polyurethane modified acrylate in this embodiment is ETERCURE DR-U079.

[0033] Example 2 This embodiment provides an EB curing glue for artificial leather, and the raw materials include the following components in parts by weight: 40 parts of modified acrylate containing cyclic carbonate; 35 parts of polyurethane modified acrylate; Silane coupling agent KH570 3 parts; 20 parts of 1,6-ethylene glycol diacrylate; 0.3 parts of leveling agent; 0.3 parts of defoaming agent.

[0034] The polyurethane modified acrylate in this embodiment is ETERCURE DR-U079.

[0035] Example 3 This embodiment provides an EB curing glue for artificial leather, and the raw materials include the following components in parts by weight: 65 parts of modified acrylate containing cyclic carbonate; 20 parts of polyurethane modified acrylate; Silane coupling agent KH570 5 parts; 10 parts of tripropylene glycol diacrylate; 0.3 parts of leveling agent; 0.3 parts of defoaming agent.

[0036] The polyurethane modified acrylate in this embodiment is ETERCURE DR-U079.

[0037] Each comparative example in the present invention is used for comparison with Example 1.

[0038] Comparative Example 1 This comparative example provides an EB curing glue for artificial leather, and the raw materials include the following components in parts by weight: 80 parts of polyurethane modified acrylate; Silane coupling agent KH570 4 parts; 1,6-ethylene glycol diacrylate 15 parts; 0.3 parts of leveling agent; 0.3 parts of defoaming agent.

[0039] The polyurethane modified acrylate in this embodiment is ETERCURE DR-U079.

[0040] Comparative Example 2 The difference between this comparative example and Example 1 is that the modified acrylate containing cyclic carbonate is replaced by modified acrylate 1, and the modified acrylate 1 is prepared according to the following method: S1: Weigh glycidyl methacrylate (GMA), N-hydroxyethyl acrylamide, methacrylic acid, azobisisobutyronitrile and dioxane in a round-bottom flask and mix them to obtain a reaction mixture; wherein the molar ratio of glycidyl methacrylate (GMA), N-hydroxyethyl acrylamide and methacrylic acid is 1:3:1; the weight of azobisisobutyronitrile is 0.5% of the total weight of glycidyl methacrylate, N-hydroxyethyl acrylamide and methacrylic acid; the mass ratio of methacrylic acid to dioxane is 1:6; S2: After the reaction mixture is filled with nitrogen to deoxygenate, the round-bottom flask is stirred at 70° C. for 24 hours. After the reaction is completed, the product is washed and vacuum dried at 45° C. to obtain a precipitated product; S3: Add 5.92 g of precipitated product, 0.01 g of catalyst p-toluenesulfonic acid, 0.001 g of hydroquinone and 20 mL of xylene into a three-hole round-bottom flask, heat to 70°C, add hydroxyethyl acrylate dropwise while stirring, monitor the reaction by FTIR measurement, stop adding hydroxyethyl acrylate after the absorption peak of the carboxyl group in the reactant disappears, the reaction is terminated, and modified acrylate 1 is obtained.

[0041] Comparative Example 3 The difference between this comparative example and Example 1 is that the modified acrylate containing cyclic carbonate is replaced by modified acrylate II, and the modified acrylate II is prepared according to the following method: S1: Weigh glycidyl methacrylate (GMA), methoxylated acrylic acid cyclocarbonate, methacrylic acid, azobisisobutyronitrile and dioxane in a round-bottom flask and mix them to obtain a reaction mixture; wherein the molar ratio of glycidyl methacrylate, methoxylated acrylic acid cyclocarbonate and methacrylic acid is 1:3:1; the weight of azobisisobutyronitrile is 0.5% of the total weight of glycidyl methacrylate, methoxylated acrylic acid cyclocarbonate and methacrylic acid; the mass ratio of methacrylic acid to dioxane is 1:6; S2: After the reaction mixture is filled with nitrogen to deoxygenate, the round-bottom flask is stirred at 70° C. for 24 hours. After the reaction is completed, the product is washed and vacuum dried at 45° C. to obtain a precipitated product; S3: Add 7.12g of precipitated product, 0.01g of catalyst p-toluenesulfonic acid, 0.001g of hydroquinone and 20mL of xylene into a three-hole round-bottom flask, heat to 70°C, add hydroxyethyl acrylate dropwise while stirring, monitor the reaction by FTIR measurement, stop adding hydroxyethyl acrylate after the absorption peak of the carboxyl group in the reactant disappears, the reaction is terminated, and modified acrylate II is obtained.

[0042] Comparative Example 4 The difference between this comparative example and Example 1 is that the modified acrylate containing cyclic carbonate is replaced by modified acrylate III, and the modified acrylate III is prepared according to the following method: S1: Weigh methoxylated acrylic acid cyclic carbonate, N-hydroxyethyl acrylamide, methacrylic acid, azobisisobutyronitrile and dioxane in a round-bottom flask and mix them to obtain a reaction mixture; wherein the molar ratio of methoxylated acrylic acid cyclic carbonate, N-hydroxyethyl acrylamide and methacrylic acid is 3:3:1; the weight of azobisisobutyronitrile is 0.5% of the total weight of methoxylated acrylic acid cyclic carbonate, N-hydroxyethyl acrylamide and methacrylic acid; the mass ratio of methacrylic acid to dioxane is 1:6; S2: After the reaction mixture is filled with nitrogen to deoxygenate, the round-bottom flask is stirred at 70° C. for 24 hours. After the reaction is completed, the product is washed and vacuum dried at 45° C. to obtain a precipitated product; S3: Add 7.22g of precipitated product, 0.01g of catalyst p-toluenesulfonic acid, 0.001g of hydroquinone and 20mL of xylene into a three-hole round-bottom flask, mix, heat to 70°C, add hydroxyethyl acrylate dropwise while stirring, monitor the reaction by FTIR measurement, stop adding hydroxyethyl acrylate after the absorption peak of the carboxyl group in the reactant disappears, the reaction is terminated, and modified acrylate three is obtained.

[0043] The performance of the EB-cured glue prepared in the above-mentioned embodiments and comparative examples was tested.

[0044] Artificial leather was prepared using the EB curing glue prepared in each embodiment and comparative example as an adhesive, and the preparation method was as follows: The prepared artificial leather was subjected to a performance test, and the test method was as follows: Plate making: Coat 15μm thermosetting leather-like coating on patterned PET release paper, and then coat 20μm EB adhesive on it after curing, and then laminate it with a substrate such as non-woven fabric, and then EB cure it. The EB curing energy is 150-200keV, and the amount of EB curing agent is 20-50kGy.

[0045] 1. Adhesion strength test: Cut the board into strips with a width of 2 cm and a length of 20 cm, and test the T peel strength on a tensile testing machine; 2. Aging resistance test: Cut the plate into strips of 2 cm wide and 20 cm long, and use the aging test machine QUVA for 720 hours, and test the T peel strength on the tensile machine.

[0046] 3. Water resistance test: Soak the board in water at room temperature for 24 hours, then bake it in an oven at 60℃ for 2 hours. Cut the board into strips with a width of 2 cm and a length of 20 cm, and test the T peel strength on a tensile testing machine.

[0047] The test results are shown in Table 1: Table 1 Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Initial bonding strength (N / m) 4.7 (Substrate damage) 4.5 (Substrate damage) 4.8 (Substrate damage) 3.3 (Substrate damage) 3.2 3.8 3.7 Aging resistance bonding strength (N / m) 4.5 4.5 4.7 3.0 2.2 3.7 3.7 Water-resistant bonding strength (N / m) 4.6 4.4 4.7 3.1 2.1 3.7 3.5 The EB-cured glue provided in Comparative Example 1 does not introduce modified acrylate containing cyclic carbonate. Due to excessive difunctional polyurethane, the bonding strength of the EB-cured glue is weak. Since the polyurethane structure is mainly aliphatic, it has good water resistance and weather resistance, and there is little change compared with the initial bonding strength.

[0048] In the preparation process of the modified acrylate in Comparative Example 2, no methoxylated acrylic cyclic carbonate was added, resulting in poor initial bonding strength and aging resistance of the EB-cured glue.

[0049] In the preparation process of the modified acrylate II in Comparative Example 3, N-hydroxyethyl acrylamide was not added. Due to the lack of the effect of the amide group, the initial bonding strength of the EB-cured glue was weak.

[0050] In the preparation process of the modified acrylate 3 in Comparative Example 4, glycidyl methacrylate was not added. Due to the lack of epoxy group effect, the initial bonding strength of the EB-cured glue was weak.

[0051] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An EB curing glue for artificial leather, characterized in that: The raw materials include the following components in parts by weight: 40-70 parts of modified acrylate containing cyclic carbonate; Polyurethane modified acrylate 20-40 parts; Silane coupling agent KH570 3~5 parts; 10-20 parts of active monomer; 0.3 parts of leveling agent; 0.3 parts of defoaming agent.

2. The artificial leather EB curing glue as claimed in claim 1, characterized in that The modified acrylate containing cyclic carbonate is prepared according to the following method: S1: mixing glycidyl methacrylate, methoxylated acrylic acid cyclocarbonate, N-hydroxyethyl acrylamide, methacrylic acid, azobisisobutyronitrile and dioxane to obtain a reaction mixture; S2: After deoxygenating the reaction mixture, stirring and reacting at 60-80° C. to obtain a precipitated product; S3: The precipitated product, catalyst p-toluenesulfonic acid, hydroquinone and xylene are mixed, the temperature is raised to 60-80° C., hydroxyethyl acrylate is added dropwise while stirring, and the reaction is monitored by FTIR measurement. After the absorption peak of the carboxyl group in the reactant disappears, the addition of hydroxyethyl acrylate is stopped, the reaction is terminated, and the modified acrylate containing cyclic carbonate is obtained.

3. The artificial leather EB curing glue as claimed in claim 2, characterized in that, In step S1, the molar ratio of the glycidyl methacrylate, the methoxylated acrylic cyclic carbonate, the N-hydroxyethyl acrylamide, and the methacrylic acid is 1:3:3:

1.

4. The artificial leather EB curing glue as claimed in claim 2, characterized in that: The weight of the azobisisobutyronitrile in step S1 is 0.5% of the total weight of the glycidyl methacrylate, the methoxylated acrylic cyclocarbonate, the N-hydroxyethyl acrylamide, and the methacrylic acid.

5. The artificial leather EB curing glue as claimed in claim 2, characterized in that: The mass ratio of the precipitated product, the catalyst p-toluenesulfonic acid, and the hydroquinone in step S3 is (7-8): 0.01: 0.

001.

6. The EB curing glue for artificial leather as claimed in claim 2, characterized in that: The mass volume ratio of the precipitated product to the xylene in step S3 is 1 g: (1-3) mL.

7. The EB curing glue for artificial leather according to any one of claims 1 to 6, characterized in that: The polyurethane modified acrylate is a bifunctional polyurethane modified acrylate.

8. The EB curing glue for artificial leather according to any one of claims 1 to 6, characterized in that: The active monomer is selected from at least one of 1,6-ethylene glycol diacrylate and tripropylene glycol diacrylate.

9. The EB curing glue for artificial leather according to any one of claims 1 to 6, characterized in that: The leveling agent is an acrylic leveling agent.

10. The EB curing glue for artificial leather according to any one of claims 1 to 6, characterized in that: The defoamer is an organosilicon defoamer or a polyether defoamer.