Sofa home solvent-free polyurethane resin as well as preparation method and application thereof

Abstract

The invention discloses solvent-free polyurethane resin for sofa home furnishing as well as a preparation method and application of the solvent-free polyurethane resin. The solvent-free polyurethane resin is prepared by mixing a component A and a component B according to a certain mass ratio (100: 90-120), wherein the component A is prepared from 90 to 95 parts of tertiary amine modified polyester polyol, 5 to 8 parts of micromolecule chain extender, 0.3 to 0.5 part of micromolecule cross-linking agent, 0.1 to 0.3 part of flatting agent and 0.1 to 0.5 part of catalyst; and the component B is prepared by reacting 80 to 90 parts of tertiary amine modified polyester polyol, 20 to 30 parts of diisocyanate and 0.1 to 0.5 part of catalyst. The solvent-free polyurethane resin provided by the invention aims to solve the problem of poor interface bonding strength between a solvent-free middle layer and a water-based surface layer in the prior art. In addition, aiming at the problem that the surface of leather is oxidized and aged by heated air due to a vulcanization process in leather processing, the invention can provide a very good solution.

Description

Technical Field

[0001] The invention relates to the field of polyurethane for synthetic leather, in particular to a solvent-free polyurethane resin for sofa furniture and a preparation method and application thereof. Background Art

[0002] Nowadays, it is an irresistible trend for traditional high-energy-consuming and polluting enterprises to transform towards green and low-carbon development. The synthetic leather industry is facing opportunities and challenges brought about by transformation and development. Traditional solvent-based polyurethane synthetic leather requires the use of a large amount of organic solvents, such as N, N-dimethylformamide, ethyl acetate and butanone, etc. in the production process. The resulting environmental pollution and occupational health hazards to employees need to be solved urgently. In order to comply with the trend of green environmental protection, water-based solvent-free synthetic leather and TPU synthetic leather are developing rapidly. Taking water-based solvent-free synthetic leather as an example, in the production process, it generally uses water-based polyurethane resin with a solvent-free foaming layer as a coating, avoiding the use of a large amount of low-toxic organic solvents.

[0003] The main problem with the water-based solvent-free process is the poor bonding between the water-based polyurethane surface layer and the solvent-free polyurethane foam layer, which has varying degrees of impact on the mechanical properties of the sofa home leather produced, especially for leather products that require higher peel strength. The hot vulcanization process is a treatment process that uses heat and vulcanizing agents to improve the wear resistance and aging resistance of rubber materials, and is usually used to make soles. However, during the vulcanization process of water-based solvent-free leather, the action of hot air will cause the solvent-free polyurethane middle layer to oxidatively degrade, resulting in a decrease in cross-linking density that affects the performance of the finished leather, and may even cause cracks on the leather surface that affect subsequent processing. Summary of the invention

[0004] The invention provides a solvent-free polyurethane resin for sofa furniture and a preparation method and application thereof, which solves the existing problem of poor bonding strength between the solvent-free layer and the aqueous layer, has excellent heat-resistant air aging performance, and enables the furniture leather to maintain good performance after being treated by a hot vulcanization process.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: A solvent-free polyurethane resin for sofa furniture, obtained by mixing component A and component B in a mass ratio of 100:90-100:120 and drying and ripening; The A component is prepared from the following components in parts by weight: 90-95 parts of tertiary amine modified polyester polyol, 5-8 parts of small molecule chain extender, Small molecule cross-linking agent 0.3-0.5 parts, Leveling agent 0.1-0.3 parts, Catalyst 0.1-0.5 parts; The B component is prepared from the following components in parts by weight: 80-90 parts of tertiary amine modified polyester polyol, 20-30 parts of diisocyanate, Catalyst 0.1-0.5 parts; The tertiary amine-modified polyester polyol in the A component and the B component is prepared by transesterification and polycondensation reaction of the following components in parts by weight: 35-45 parts of isophthalate, 80-90 parts of tertiary amine diol, 20-30 parts of polyether diol, 1-3 parts of antioxidant, Tetraisobutyl titanate 0.1-0.5 parts.

[0006] Furthermore, in the tertiary amine-modified polyester polyols of the A component and the B component, the polyether diol is polyoxypropylene diol, and the molecular weight is between 500-2000.

[0007] Furthermore, in the tertiary amine-modified polyester polyols of the A component and the B component, the tertiary amine diol is selected from at least one of N-methyldiethanolamine, N-ethyldiethanolamine and N-propyldiethanolamine.

[0008] Furthermore, in the tertiary amine-modified polyester polyols of component A and component B, the antioxidant is selected from any one of 1010, 1035, 1076, and 1098.

[0009] Furthermore, in the component A, the small molecule chain extender is selected from any one of ethylene glycol and 1,4-butanediol; the small molecule cross-linking agent is selected from any one of glycerol and trimethylolpropane; the leveling agent is an organosilicon leveling agent, and the organosilicon leveling agent is BYK-9565; Furthermore, in the component B, the diisocyanate is selected from any one of 4,4'-diphenylmethane diisocyanate, a mixture of 2,4-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate in a mass ratio of 1:1, isophorone diisocyanate, hexamethylene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

[0010] Furthermore, in the component A and the component B, the catalyst is selected from a delayed-type metal catalyst or any one of its phenolate, formates, and hydrochlorides, and the delayed-type environmentally friendly catalyst is selected from any one of BiCAT 8106, BiCAT 8108, BiCAT8124, BiCAT 3228, Borchi Kat 22, Borchi Kat 24, BiCAT 4130, BiCAT 4232, and MB20.

[0011] A method for preparing the above-mentioned solvent-free polyurethane resin for sofa home use, the process is as follows: (1) Preparation of tertiary amine modified polyester polyols: Add the measured amount of isophthalic acid ester, tertiary amine type diol and catalyst diisobutyl titanate into a three-necked flask and slowly heat to 150-180 o C, carry out ester exchange reaction, and end the ester exchange reaction when the amount of methanol distillation no longer increases. Add the measured polyether diol and antioxidant, pass nitrogen, and raise the temperature to the polycondensation reaction temperature of 220-240 o C, after keeping warm for half an hour, evacuate the mixture, maintain a certain vacuum degree and temperature to carry out polycondensation reaction, and react until the hydroxyl value of the obtained product reaches 28-112 mgKOH / g, thereby obtaining a tertiary amine-modified polyester polyol with a molecular weight of 1000-4000; (2) Preparation of component A: Mix tertiary amine modified polyester polyol, small molecule chain extender, small molecule cross-linking agent, leveling agent and catalyst at room temperature, then heat to 60-80 o C is stirred for 1-3 hours to obtain component A; (3) Preparation of component B: The tertiary amine-modified polyester polyol, diisocyanate and catalyst are stirred at room temperature for 10-20 minutes, and then heated to 60-90°C and stirred for reaction for 2-4 hours to obtain component B; (4) Preparation of solvent-free polyurethane resin: The component A and the component B are fully mixed in a mass ratio of 100:90-100:120 and dried and matured to obtain a solvent-free polyurethane resin.

[0012] The solvent-free polyurethane resin for sofa furniture is used in the preparation of water-based solvent-free polyurethane synthetic leather. The solvent-free polyurethane resin for sofa furniture is used as the middle layer of water-based solvent-free sofa furniture leather. When used, the water-based polyurethane surface layer resin is coated on the release paper and heated to 100-130 °C. o C drying to form a waterborne polyurethane surface layer; pouring and coating the solvent-free polyurethane resin for sofa home use as described above on the surface of the waterborne polyurethane surface layer, at 100-130 oC pre-reacted for 30-90s and then bonded to the base fabric, then heated at 100-130 o C continues to react for 5-10 minutes to crosslink and solidify the leather into a shape; after forming, the leather is rolled up and peeled off to obtain a water-based solvent-free polyurethane synthetic leather.

[0013] Compared with the prior art, the present invention has the following advantages: (1) The present invention provides a tertiary amine-modified polyester polyol, which, on the one hand, promotes the chain growth reaction of solvent-free polyurethane on a weakly acidic water-based surface layer through the weak alkalinity and catalytic effect of the tertiary amine group itself; on the other hand, introduces an aromatic ring structure with large cohesive energy into the polyester structure to improve the weak interaction force between the polyester and the water-based layer, and combines these two aspects to improve the bonding strength with the water-based surface layer and the heat-air aging resistance. In addition, the hydrophobicity and adhesion of the tertiary amine-modified polyol are improved by embedding a branched polyether chain segment.

[0014] (2) The polyol mixture component A and the isocyanate prepolymer component B provided by the present invention do not require the use of organic solvents during production and application, which is in line with the development trend of green environmental protection. DETAILED DESCRIPTION

[0015] Embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0017] Embodiment 1: Embodiment 1 provides a solvent-free polyurethane resin for sofa home use, which is obtained by mixing component A and component B in a mass ratio of 100:90 and drying and aging; The A component is prepared from the following components in parts by weight: 90 parts of tertiary amine modified polyester polyol, 5 parts of small molecule chain extender, 0.3 parts of small molecule cross-linking agent, 0.1 part of leveling agent, 0.1 part of catalyst; The B component is prepared from the following components in parts by weight: 80 parts of tertiary amine modified polyester polyol, 20 parts of diisocyanate, 0.1 part of catalyst; The tertiary amine-modified polyester polyol in the A component and the B component is prepared by transesterification and polycondensation reaction of the following components in parts by weight: 35 parts of isophthalate, 80 parts of tertiary amine diol, 20 parts of polyether diol, 1 part antioxidant, 0.1 parts of tetraisobutyl titanate.

[0018] In the tertiary amine-modified polyester polyols of component A and component B, the polyether diol is polyoxypropylene diol with a molecular weight between 500-2000.

[0019] In the tertiary amine-modified polyester polyols of component A and component B, the tertiary amine diol is selected from at least one of N-methyldiethanolamine, N-ethyldiethanolamine and N-propyldiethanolamine.

[0020] In the tertiary amine-modified polyester polyols of component A and component B, the antioxidant is selected from any one of 1010, 1035, 1076, and 1098.

[0021] In component A, the small molecule chain extender is selected from any one of ethylene glycol and 1,4-butanediol; the small molecule cross-linking agent is selected from any one of propylene glycol and trimethylolpropane; the leveling agent is an organosilicon leveling agent, and the organosilicon leveling agent is BYK-9565; In component B, the diisocyanate is selected from any one of 4,4'-diphenylmethane diisocyanate, a mixture of 2,4-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate in a mass ratio of 1:1, isophorone diisocyanate, hexamethylene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

[0022] In component A and component B, the catalyst is selected from a delayed-type metal catalyst or any one of its phenolate, formates, and hydrochlorides, and the delayed-type environmentally friendly catalyst is selected from any one of BiCAT 8106, BiCAT 8108, BiCAT 8124, BiCAT 3228, Borchi Kat 22, Borchi Kat 24, BiCAT 4130, BiCAT 4232, and MB20.

[0023] The polyether diol in component A is polyoxypropylene diol with a number average molecular weight of 500-2000 produced by Kunshan Guodu Chemical Company; BYK-9565 is a silicone leveling agent produced by BYK Additives; BiCAT 8106 is a delayed catalyst of a leading American chemical company; N-methyldiethanolamine is produced by Shanghai Aladdin Biochemical Technology Co., Ltd.; isophthalic acid ester is produced by Sinopharm Chemical Reagent Co., Ltd.; antioxidants 1010, 1035, and 1076 are produced by Double Bond Chemical Co., Ltd. of Taiwan, China; ethylene glycol and propylene glycol are commercially available products.

[0024] The wannate MDI-100 in component B is 4,4'-diphenylmethane diisocyanate produced by Yantai Wanhua Company; MB20 is an organic bismuth catalyst produced by Air Chemicals and Chemicals of the United States.

[0025] The waterborne polyurethane surface resin was purchased from Wanhua Chemical Group Co., Ltd. under the brand name Tekspro 5215.

[0026] Embodiment 1 provides a method for preparing the above-mentioned solvent-free polyurethane resin for sofa home use, comprising the following steps: (1) Preparation of tertiary amine modified polyester polyols: Add 35g of isophthalic acid ester, 80g of tertiary amine type diol N-methyldiethanolamine and 0.1g of catalyst tetraisobutyl titanate into a three-necked flask and slowly heat to 150 o C, and transesterification reaction was carried out. When the amount of methanol distilled out no longer increased, the transesterification reaction was terminated. 20 g of polyoxypropylene glycol with a number average molecular weight of 600 and 1 g of antioxidant were added, nitrogen was passed, and the temperature was raised to the polycondensation reaction temperature of 220 o C, keep warm for half an hour and then evacuate, maintain a certain vacuum degree and temperature to carry out polycondensation reaction, react until the hydroxyl value of the obtained product reaches 107-117 mg KOH / g, and obtain a tertiary amine modified polyester polyol with a molecular weight of 1000.

[0027] (2) Preparation of component A: 90 g of tertiary amine-modified polyester polyol, 5 g of ethylene glycol, 0.3 g of propylene glycol, 0.1 g of leveling agent BYK-9565 and 0.1 g of catalyst BiCAT 8106 were mixed at room temperature and then heated to 60 o C was stirred for 1 h to obtain component A.

[0028] (3) Preparation of component B: 80g of tertiary amine modified polyester polyol, 20g of diisocyanate wannate MDI-100 and 0.1g of catalyst MB20 were stirred at room temperature for 10-20min and then heated to 60 o C continued to stir the reaction for 2 h to obtain component B.

[0029] (4) Preparation of solvent-free polyurethane resin: Component A and component B are fully mixed in a mass ratio of 100:90 and dried and aged to obtain a solvent-free polyurethane resin.

[0030] Example 1 also provides an application of the above-mentioned solvent-free polyurethane resin for sofa home use in the preparation of water-based solvent-free polyurethane synthetic leather. When applied, a water-based polyurethane surface layer resin Tekspro 5215 is coated on the release paper and heated at 100 °C. o C drying to form a waterborne polyurethane surface layer; pouring and coating the solvent-free polyurethane resin for sofa home use as described above on the surface of the waterborne polyurethane surface layer, at 100 o C pre-reacted for 90s and then bonded to the base fabric. o C continued to react for 10 minutes to crosslink and solidify the leather; after forming, the leather was rolled up and peeled off to obtain a water-based solvent-free polyurethane synthetic leather.

[0031] Example 2 Example 2 provides a solvent-free polyurethane resin for sofa home use, which is obtained by mixing component A and component B in a mass ratio of 100:110 and drying and aging; The A component is prepared from the following components in parts by weight: 92 parts of tertiary amine modified polyester polyol, 6 parts of small molecule chain extender, 0.4 parts of small molecule cross-linking agent, 0.2 parts of leveling agent, 0.3 parts of catalyst; The B component is prepared from the following components in parts by weight: 85 parts of tertiary amine modified polyester polyol, 25 parts of diisocyanate, 0.3 parts of catalyst; The tertiary amine-modified polyester polyol in the A component and the B component is prepared by transesterification and polycondensation reaction of the following components in parts by weight: 40 parts of isophthalate, 85 parts of tertiary amine diol, 25 parts of polyether diol, 1 part antioxidant, 0.1 parts of tetraisobutyl titanate.

[0032] In the tertiary amine-modified polyester polyols of component A and component B, the polyether diol is polyoxypropylene diol with a molecular weight between 500-2000.

[0033] In the tertiary amine-modified polyester polyols of component A and component B, the tertiary amine diol is selected from at least one of N-methyldiethanolamine, N-ethyldiethanolamine and N-propyldiethanolamine.

[0034] In the tertiary amine-modified polyester polyols of component A and component B, the antioxidant is selected from any one of 1010, 1035, 1076, and 1098.

[0035] In component A, the small molecule chain extender is selected from any one of ethylene glycol and 1,4-butanediol; the small molecule cross-linking agent is selected from any one of propylene glycol and trimethylolpropane; the leveling agent is an organosilicon leveling agent, and the organosilicon leveling agent is BYK-9565; In component B, the diisocyanate is selected from any one of 4,4'-diphenylmethane diisocyanate, a mixture of 2,4-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate in a mass ratio of 1:1, isophorone diisocyanate, hexamethylene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

[0036] In component A and component B, the catalyst is selected from a delayed-type metal catalyst or any one of its phenolate, formates, and hydrochlorides, and the delayed-type environmentally friendly catalyst is selected from any one of BiCAT 8106, BiCAT 8108, BiCAT 8124, BiCAT 3228, Borchi Kat 22, Borchi Kat 24, BiCAT 4130, BiCAT 4232, and MB20.

[0037] The polyether diol in component A is polyoxypropylene diol with a number average molecular weight of 500-2000 produced by Kunshan Guodu Chemical Company; BYK-9565 is a silicone leveling agent produced by BYK Additives; BiCAT 8106 is a delayed catalyst of a leading American chemical company; N-methyldiethanolamine is produced by Shanghai Aladdin Biochemical Technology Co., Ltd.; isophthalic acid ester is produced by Sinopharm Chemical Reagent Co., Ltd.; antioxidants 1010, 1035, and 1076 are produced by Double Bond Chemical Co., Ltd. of Taiwan, China; ethylene glycol and propylene glycol are commercially available products.

[0038] The wannate MDI-100 in component B is 4,4'-diphenylmethane diisocyanate produced by Yantai Wanhua Company; MB20 is an organic bismuth catalyst produced by Air Chemicals and Chemicals of the United States.

[0039] The waterborne polyurethane surface resin was purchased from Wanhua Chemical Group Co., Ltd. under the brand name Tekspro 5215.

[0040] Embodiment 2 provides a method for preparing a solvent-free polyurethane resin for sofa home use, comprising the following steps: (1) Preparation of tertiary amine modified polyester polyol: Add 40g of isophthalic acid ester, 85g of tertiary amine type diol N-methyldiethanolamine and 0.3g of catalyst tetraisobutyl titanate into a three-necked flask and slowly heat to 170 o C, and carry out transesterification reaction. When the amount of methanol distilled out no longer increases, the transesterification reaction is terminated. Add 25g of polyoxypropylene glycol with a number average molecular weight of 1000 and 2g of antioxidant, pass nitrogen, and raise the temperature to the polycondensation reaction temperature of 230 o C, keep warm for half an hour and then evacuate, maintain a certain vacuum degree and temperature to carry out polycondensation reaction, react until the hydroxyl value of the obtained product reaches 51-61 mg KOH / g, and obtain a tertiary amine modified polyester polyol with a molecular weight of 2000.

[0041] (2) Preparation of component A: 92 g of tertiary amine-modified polyester polyol, 6 g of ethylene glycol, 0.4 g of propylene glycol, 0.2 g of leveling agent BYK-9565 and 0.3 g of catalyst BiCAT 8106 were mixed at room temperature and then heated to 70 °C. o C was stirred for 2 h to obtain component A.

[0042] (3) Preparation of component B: 85 g of tertiary amine-modified polyester polyol, 25 g of diisocyanate wannate MDI-100 and 0.3 g of catalyst MB20 were stirred at room temperature for 15 min, and then heated to 70 o C continued to stir the reaction for 3 hours to obtain component B.

[0043] (4) Preparation of solvent-free polyurethane resin: Component A and component B are fully mixed in a mass ratio of 100:110 and dried and aged to obtain a solvent-free polyurethane resin.

[0044] Example 2 also provides an application of the above-mentioned solvent-free polyurethane resin for sofa home use in the preparation of water-based solvent-free polyurethane synthetic leather. When applied, a water-based polyurethane surface layer resin Tekspro 5215 is coated on the release paper and heated at 120 o C to form a waterborne polyurethane surface layer; casting and coating the solvent-free intermediate layer resin as described above on the surface of the waterborne polyurethane surface layer; o After pre-reaction at C for 50s, the base fabric was bonded and then heated at 120 o C continued to react for 8 minutes to crosslink and solidify the leather into a shape; after forming, the leather was rolled up and peeled off to obtain a water-based solvent-free polyurethane synthetic leather.

[0045] Embodiment 3: Example 3 provides a solvent-free polyurethane resin for sofa home use, which is obtained by mixing component A and component B in a mass ratio of 100:120 and drying and aging; The A component is prepared from the following components in parts by weight: 95 parts of tertiary amine modified polyester polyol, 8 parts of small molecule chain extender, 0.5 parts of small molecule cross-linking agent, 0.3 parts of leveling agent, 0.5 part of catalyst; The B component is prepared from the following components in parts by weight: 90 parts of tertiary amine modified polyester polyol, 30 parts of diisocyanate, 0.5 part of catalyst; The tertiary amine-modified polyester polyol in the A component and the B component is prepared by transesterification and polycondensation reaction of the following components in parts by weight: 45 parts of isophthalate, 90 parts of tertiary amine diol, 30 parts of polyether diol, 3 parts of antioxidant, 0.5 parts of tetraisobutyl titanate.

[0046] In the tertiary amine-modified polyester polyols of component A and component B, the polyether diol is polyoxypropylene diol with a molecular weight between 500-2000.

[0047] In the tertiary amine-modified polyester polyols of component A and component B, the tertiary amine diol is selected from at least one of N-methyldiethanolamine, N-ethyldiethanolamine and N-propyldiethanolamine.

[0048] In the tertiary amine-modified polyester polyols of component A and component B, the antioxidant is selected from any one of 1010, 1035, 1076, and 1098.

[0049] In component A, the small molecule chain extender is selected from any one of ethylene glycol and 1,4-butanediol; the small molecule cross-linking agent is selected from any one of propylene glycol and trimethylolpropane; the leveling agent is an organosilicon leveling agent, and the organosilicon leveling agent is BYK-9565; In component B, the diisocyanate is selected from any one of 4,4'-diphenylmethane diisocyanate, a mixture of 2,4-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate in a mass ratio of 1:1, isophorone diisocyanate, hexamethylene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

[0050] In component A and component B, the catalyst is selected from a delayed-type metal catalyst or any one of its phenolate, formates, and hydrochlorides, and the delayed-type environmentally friendly catalyst is selected from any one of BiCAT 8106, BiCAT 8108, BiCAT 8124, BiCAT 3228, Borchi Kat 22, Borchi Kat 24, BiCAT 4130, BiCAT 4232, and MB20.

[0051] The polyether diol in component A is polyoxypropylene diol with a number average molecular weight of 500-2000 produced by Kunshan Guodu Chemical Company; BYK-9565 is a silicone leveling agent produced by BYK Additives; BiCAT 8106 is a delayed catalyst of a leading American chemical company; N-methyldiethanolamine is produced by Shanghai Aladdin Biochemical Technology Co., Ltd.; isophthalic acid ester is produced by Sinopharm Chemical Reagent Co., Ltd.; antioxidants 1010, 1035, and 1076 are produced by Double Bond Chemical Co., Ltd. of Taiwan, China; ethylene glycol and propylene glycol are commercially available products.

[0052] The wannate MDI-100 in component B is 4,4'-diphenylmethane diisocyanate produced by Yantai Wanhua Company; MB20 is an organic bismuth catalyst produced by Air Chemicals and Chemicals of the United States.

[0053] The waterborne polyurethane surface resin was purchased from Wanhua Chemical Group Co., Ltd. under the brand name Tekspro 5215.

[0054] Embodiment 3 provides a method for preparing a solvent-free polyurethane resin for sofa home use, comprising the following steps: (1) Preparation of tertiary amine modified polyester polyol: Add 45g of isophthalic acid ester, 90g of tertiary amine type diol N-methyldiethanolamine and 0.5g of catalyst tetraisobutyl titanate into a three-necked flask and slowly heat to 180 o C, and transesterification reaction was carried out. When the amount of methanol distilled out no longer increased, the transesterification reaction was terminated. 30 g of polyoxypropylene glycol with a number average molecular weight of 2000 and 3 g of antioxidant were added, nitrogen was passed through, and the temperature was raised to the polycondensation reaction temperature of 240 o C, and then evacuate the mixture after keeping the temperature for half an hour, and maintain a certain vacuum degree and temperature to carry out polycondensation reaction until the hydroxyl value of the obtained product reaches 26-30 mg KOH / g, thereby obtaining a tertiary amine-modified polyester polyol with a molecular weight of 4000.

[0055] (2) Preparation of component A: 95 g of tertiary amine-modified polyester polyol, 8 g of ethylene glycol, 0.5 g of propylene glycol, 0.3 g of leveling agent BYK-9565 and 0.5 g of catalyst BiCAT 8106 were mixed at room temperature and then heated to 80 °C. oC was stirred for 3 h to obtain component A.

[0056] (3) Preparation of component B: 90 g of tertiary amine-modified polyester polyol, 30 g of diisocyanate wannate MDI-100 and 0.5 g of catalyst MB20 were stirred at room temperature for 20 min, and then heated to 90 o C continued to stir the reaction for 4 hours to obtain component B.

[0057] (4) Preparation of solvent-free polyurethane resin: Component A and component B are fully mixed in a mass ratio of 100:120 and dried and aged to obtain a solvent-free polyurethane resin.

[0058] Example 3 also provides an application of the above-mentioned solvent-free polyurethane resin for sofa home use in the preparation of water-based solvent-free polyurethane synthetic leather. When applied, a water-based polyurethane surface layer resin Tekspro 5215 is coated on the release paper and heated at 130 o C drying to form a waterborne polyurethane surface layer; pouring and coating the solvent-free polyurethane resin for sofa home use as described above on the surface of the waterborne polyurethane surface layer, at 130 o After pre-reaction at 130°C for 30 seconds, the base fabric was bonded. o C continued to react for 5 minutes to crosslink and solidify the leather into a shape; after forming, the leather was rolled up and peeled off to obtain a water-based solvent-free polyurethane synthetic leather.

[0059] Comparative Example 1 provides a preparation method and application of a solvent-free polyurethane resin for sofa home use, which differs from Example 1 only in that N-methyldiethanolamine is replaced with an equal mass of ethylene glycol during the preparation of the tertiary amine-modified polyester polyol component.

[0060] Comparative Example 2 provides a preparation method and application of a solvent-free polyurethane resin for sofa home use, which differs from Example 1 in that terephthalate is replaced with an equal mass of polybutylene adipate in the process of preparing the tertiary amine-modified polyester polyol component.

[0061] Performance Test: (1) Peel strength: tested in accordance with GB / T 1040.3-2006; (2) Hot air aging resistance: Refer to the hot air aging standard for vulcanized rubber GB / T 3512-2014 to test the change rate of tensile strength before and after aging.

[0062] The synthetic leathers obtained in Examples 1 to 3 and Comparative Application Examples 1 to 2 were tested according to the above test method. The test results are shown in Table 1: Table 1 Test results

[0063] It can be seen from the above examples and comparative examples that the peel strength and heat air aging resistance of the solvent-free polyurethanes prepared by tertiary amine-modified polyester polyols (Examples 1 to 3) are significantly better than those of the solvent-free polyurethanes without tertiary amine groups (Comparative Application Example 1) or rigid aromatic ring groups (Comparative Application Example 2). This is because the weak alkalinity and catalytic effect of the tertiary amine groups enable the molecular chain of the solvent-free polyurethane on the aqueous surface layer to grow sufficiently, and the aromatic ring structure with greater cohesive energy improves the weak interaction force with the aqueous layer, thereby further improving the bonding strength with the aqueous surface layer.

[0064] In summary, the solvent-free polyurethane resin for sofa home furnishing provided by the present invention significantly improves the bonding strength with the water-based surface layer by introducing tertiary amine groups and aromatic ring structures, solves the problem of poor mechanical properties of water-based solvent-free sofa home furnishing leather prepared by ordinary solvent-free resins, and has wide applicability.

[0065] The above is only a preferred embodiment of the present invention and is not intended to limit the invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A solvent-free polyurethane resin for sofa home use, characterized in that: The mixture is obtained by mixing component A and component B in a mass ratio of 100:90-100:120 and drying and ripening. The A component is prepared from the following components in parts by weight: 90-95 parts of tertiary amine modified polyester polyol, 5-8 parts of small molecule chain extender, Small molecule cross-linking agent 0.3-0.5 parts, Leveling agent 0.1-0.3 parts, Catalyst 0.1-0.5 parts; The B component is prepared from the following components in parts by weight: 80-90 parts of tertiary amine modified polyester polyol, 20-30 parts of diisocyanate, Catalyst 0.1-0.5 parts; The tertiary amine-modified polyester polyol in the A component and the B component is prepared by transesterification and polycondensation of the following components in parts by weight: 35-45 parts of isophthalate, 80-90 parts of tertiary amine diol, 20-30 parts of polyether diol, 1-3 parts of antioxidant, Tetraisobutyl titanate 0.1-0.5 parts.

2. A solvent-free polyurethane resin for sofa home use according to claim 1, characterized in that: In the tertiary amine-modified polyester polyols of the A component and the B component, the polyether diol is polyoxypropylene diol with a molecular weight between 500-2000.

3. The solvent-free polyurethane resin for sofa home use according to claim 1, characterized in that: In the tertiary amine-modified polyester polyols of the A component and the B component, the tertiary amine diol is selected from at least one of N-methyldiethanolamine, N-ethyldiethanolamine and N-propyldiethanolamine.

4. The solvent-free polyurethane resin for sofa home use according to claim 1, characterized in that: In the tertiary amine-modified polyester polyols of the A component and the B component, the antioxidant is selected from any one of 1010, 1035, 1076, and 1098.

5. The solvent-free polyurethane resin for sofa home use according to claim 1, characterized in that: In the component A, the small molecule chain extender is selected from any one of ethylene glycol and 1,4-butanediol; the small molecule cross-linking agent is selected from any one of propylene glycol and trimethylolpropane; the leveling agent is an organosilicon leveling agent, and the organosilicon leveling agent is BYK-9565.

6. The solvent-free polyurethane resin for sofa home use according to claim 1, characterized in that: In the component B, the diisocyanate is selected from any one of 4,4'-diphenylmethane diisocyanate, a mixture of 2,4-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate in a mass ratio of 1:1, isophorone diisocyanate, hexamethylene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

7. The solvent-free polyurethane resin for sofa home use according to claim 1, characterized in that: In the A component and the B component, the catalyst is selected from a delayed-type metal catalyst or any one of its phenolate, formates, and hydrochlorides, and the delayed-type environmentally friendly catalyst is selected from any one of BiCAT 8106, BiCAT 8108, BiCAT 8124, BiCAT 3228, Borchi Kat22, Borchi Kat 24, BiCAT 4130, BiCAT 4232, and MB20.

8. A method for preparing a solvent-free polyurethane resin for sofa furniture according to any one of claims 1 to 7, characterized in that: The process is as follows: (1) Preparation of tertiary amine modified polyester polyol: add isophthalic acid ester, tertiary amine type diol, polyether diol, antioxidant and tetraisobutyl titanate into a reaction vessel and mix well. Heat the reaction vessel to 220-240°C under an inert atmosphere. o C to react until the hydroxyl value of the obtained product reaches 28-112 mg KOH / g, thereby obtaining a tertiary amine-modified polyester polyol having a molecular weight of 1000-4000; (2) Preparation of component A: Mix tertiary amine-modified polyester polyol, small molecule chain extender, small molecule cross-linking agent, leveling agent and catalyst at room temperature, then heat to 60-80 o C is stirred for 1-3 hours to obtain component A; (3) Preparation of component B: tertiary amine-modified polyester polyol, diisocyanate and catalyst are mixed at room temperature, and then heated to 70-90° C. and stirred for reaction for 2-4 hours to obtain component B; (4) Preparation of solvent-free polyurethane resin: Component A and component B are fully mixed in a mass ratio of 100:90-100:120 and dried and matured to obtain a solvent-free polyurethane resin.

9. Use of the solvent-free polyurethane resin for sofa home use as claimed in any one of claims 1 to 7 in the preparation of water-based solvent-free polyurethane synthetic leather.

Images