Wet-process polyurethane resin for synthetic leather for laminating ABS plastic parts, preparation method thereof, and synthetic leather

Abstract

The present invention relates to a wet-process polyurethane resin for synthetic leather for laminating ABS plastic parts, a preparation method thereof and synthetic leather, wherein the raw materials of the wet-process polyurethane resin include polyester polyol, polyether polyol, AS resin, isocyanate, chain extender, solvent and terminator, wherein the chain extender is 1,3-butanediol. The wet-process polyurethane resin of the present invention innovatively introduces a certain amount of AS resin in a specific formula and cooperates with the use of a specific chain extender 1,3-butanediol, on the one hand, the AS resin is embedded in the chain segment of the polyurethane resin, and the similar compatibility principle is used to make the impregnated synthetic leather prepared by the wet-process polyurethane resin of the present invention have good compatibility with ABS plastic parts, and realize high-frequency lamination with ABS plastic parts, and on the other hand, 1,3-butanediol is used as a chain extender to reduce the crystallinity of the polyurethane resin and further improve the lamination fastness with ABS plastic parts.

Description

Technical Field

[0001] The invention specifically relates to a wet-process polyurethane resin for synthetic leather used for bonding ABS plastic parts, a preparation method thereof and synthetic leather. Background Art

[0002] The process of preparing impregnated synthetic leather using wet polyurethane resin is to mix wet polyurethane resin and DMF solvent into impregnation liquid, add it into the impregnation tank, vacuum degassing, and then pass the non-woven fabric through the impregnation tank for impregnation treatment, and then put it into water to replace the DMF solvent. The polyurethane resin gradually solidifies to form a microporous polyurethane surface layer, and then after rolling, drying and shaping, cooling, the impregnated synthetic leather is obtained. The synthesis of wet polyurethane resin used in impregnated synthetic leather on the domestic market is mainly prepared by polymerization reaction of polyols (one or more of polyester polyols, polyether polyols, and polycarbonate polyols) and small molecule alcohols (one or more of ethylene glycol, 1,4-butanediol, and neopentyl glycol) with diphenylmethane diisocyanate in the solvent DMF system.

[0003] The steering wheel and the lower guard plate of the dashboard are made of ABS (acrylonitrile-butadiene-styrene copolymer) plastic parts, and the lining is synthetic leather, which plays a role in reducing resonance and noise. However, due to the wet polyurethane resin, the impregnated synthetic leather currently on the domestic market cannot be directly bonded to ABS plastic parts using high-frequency technology. Instead, it is necessary to use adhesives to bond the impregnated synthetic leather to ABS plastic parts, which not only increases the structural cost, but also poses environmental problems. The synthetic leather on domestic joint venture cars that can be directly bonded to ABS plastic parts using high-frequency technology is imported synthetic leather, which is expensive. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and provide a low-cost wet polyurethane resin for synthetic leather that can be directly bonded to ABS plastic parts, avoid the use of adhesives, and can replace imported synthetic leather that can be directly bonded to ABS plastic parts.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme:

[0006] A wet-process polyurethane resin for synthetic leather for laminating ABS plastic parts, wherein the raw materials of the wet-process polyurethane resin include, by weight percentage:

[0007]

[0008] Wherein, the chain extender is 1,3-butanediol.

[0009] In the present invention, the AS resin is a styrene-acrylonitrile copolymer. Preferably, the AS resin can be selected from Jilin Petrochemical SAN-2437 and Lanzhou Petrochemical C-01.

[0010] Furthermore, the number average molecular weight of the polyester polyol is 1500-2500.

[0011] Furthermore, the polyester polyol is a polyester polyol of a neopentyl glycol-adipic acid system.

[0012] Furthermore, the number average molecular weight of the polyether polyol is 1500-2500.

[0013] Furthermore, the polyether polyol is polytetramethylene ether diol.

[0014] Furthermore, the isocyanate is diphenylmethane diisocyanate.

[0015] Furthermore, the terminator is methanol.

[0016] Furthermore, the solvent is N,N-dimethylformamide.

[0017] Furthermore, the raw materials of the wet-process polyurethane resin also include one or more of an antioxidant and a catalyst.

[0018] Preferably, the raw materials of the wet-process polyurethane resin include, by weight percentage:

[0019]

[0020] The second technical scheme adopted by the present invention is: a preparation method of the wet-process polyurethane resin for synthetic leather for bonding ABS plastic parts as described above, comprising adding polyester polyol, polyether polyol, chain extender, the first part of solvent, isocyanate and / or antioxidant into a reaction kettle, reacting at 70-80° C. for 0.5-2.5 hours, then adding AS resin and / or catalyst, when the viscosity reaches a specified value, adding the second part of solvent for dilution, continuing the reaction until the viscosity reaches a preset value, adding a terminator and the third part of solvent, terminating the reaction, and obtaining a wet-process polyurethane resin, wherein the first part of solvent accounts for 20-30% of the total amount of the solvent, and the second part of solvent accounts for 10-20% of the total amount of the solvent.

[0021] Furthermore, the prescribed value of the viscosity is 50,000 to 60,000 / 65°C.

[0022] Furthermore, the preset value of the viscosity is 70,000 to 80,000 / 65°C.

[0023] Furthermore, the viscosity of the wet-process polyurethane resin is 100-160 Pa.S / 25°C.

[0024] The third technical solution adopted by the present invention is: a synthetic leather for bonding ABS plastic parts, the synthetic leather includes a base fabric layer and a polyurethane resin layer formed on two surfaces of the base fabric layer by impregnation, the polyurethane resin layer is made of the wet polyurethane resin described above, when the synthetic leather is used to bond with the ABS plastic part, one of the two surfaces of the synthetic leather is directly bonded to the ABS plastic part.

[0025] Furthermore, the bonding between the synthetic leather and the ABS plastic part is performed by high-frequency heating.

[0026] The high-frequency heating bonding adopts a high-frequency heat sealing machine, which utilizes the high-frequency electron tube's self-excited high-frequency oscillation to instantly generate a high-frequency electromagnetic field, so that the polar molecules inside the plastic are polarized and rub against each other to generate heat, thereby achieving the purpose of welding the plastic, and the welding temperature is uniform inside and outside.

[0027] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0028] The wet-process polyurethane resin of the present invention innovatively introduces a certain amount of AS resin in a specific formula and cooperates with the use of a specific chain extender 1,3-butanediol. On the one hand, the AS resin is embedded in the chain segment of the polyurethane resin, and the similar compatibility principle is used to make the impregnated synthetic leather prepared by the wet-process polyurethane resin of the present invention have good compatibility with ABS plastic parts and achieve high-frequency bonding with ABS plastic parts. On the other hand, 1,3-butanediol is used as a chain extender to reduce the crystallinity of the polyurethane resin and further improve the bonding fastness with ABS plastic parts. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention is further described in detail below in conjunction with specific embodiments, but the implementation and protection scope of the present invention are not limited thereto.

[0030] Example 1

[0031] The wet-process polyurethane resin for synthetic leather used for laminating ABS plastic parts provided in this embodiment has a raw material formula as shown in Table 1, wherein:

[0032] The polyester polyol is N-56, which is sourced from Jiangsu Huada New Materials Co., Ltd.

[0033] The polyether polyol was polytetramethylene ether diol with a number average molecular weight of 2000, purchased from BASF, Germany.

[0034] The AS resin is Jilin Petrochemical SAN-2437.

[0035] The chain extender is 1,3-butanediol.

[0036] The isocyanate is diphenylmethane diisocyanate.

[0037] The solvent is N,N-dimethylformamide.

[0038] The catalyst is bismuth carboxylate.

[0039] The terminator was methanol.

[0040] The antioxidant was HW-245 from Penglai Hongwei Chemical Co., Ltd.

[0041] The wet process polyurethane resin of this example is prepared by the following method:

[0042] Add a formulated amount of polyester polyol, a formulated amount of polyether polyol, a formulated amount of chain extender, a formulated amount of antioxidant and a formulated amount of 25% solvent into a reactor, stir at 50-60°C for 40 minutes, add a formulated amount of isocyanate after fully stirring, and with the reaction heat and appropriate auxiliary heating, the temperature rises to 70-80°C and reacts at this temperature for 1 hour, then add a formulated amount of AS resin and a catalyst, as the reaction proceeds, the viscosity increases, when the viscosity reaches the specified value of 55,000 / 65°C, add a formulated amount of 15% solvent for dilution, when the viscosity reaches the preset value of 70,000 / 65°C of the end point, add a formulated amount of terminator and the remaining solvent, continue stirring for 80 minutes until the viscosity is stable, at which time the viscosity is 120Pa.S / 25°C, discharge and package, and obtain a wet-process polyurethane resin.

[0043] The raw material formulas of the wet-process polyurethane resins for synthetic leather for laminating ABS plastic parts provided in Examples 2 to 5 are shown in Table 1, and the preparation methods are the same as those in Example 1.

[0044] Comparative Example 1

[0045] The wet-process polyurethane resin provided in this comparative example is different from that in Example 1 in that ethylene glycol is used instead of 1,3-butanediol resin.

[0046] Comparative Example 2

[0047] The wet-process polyurethane resin provided in this comparative example is different from that in Example 1 in that AS resin is not used.

[0048] Comparative Example 3

[0049] The wet-process polyurethane resin provided in this comparative example is different from that in Example 1 in that the amount of AS resin is increased to 7 parts.

[0050] Table 1 is the formula of the wet polyurethane resin of Examples 1 to 5 (by weight)

[0051] Example 1 Example 2 Example 3 Example 4 Example 5 Polyester polyols 12.53 15.00 15.00 12.03 11.53 Polyether polyols 6.30 3.83 3.83 5.80 5.80 Chain Extender 2.00 2.00 2.30 2.50 3.00 Isocyanate 7.08 7.08 7.28 6.58 7.58 Solvents 70.00 70.00 70.00 70.00 70.00 catalyst 0.02 0.02 0.02 0.02 0.02 Antioxidants 0.03 0.03 0.03 0.03 0.03 AS resin 2.50 2.50 2.00 3.50 2.50 Terminator 0.04 0.04 0.04 0.04 0.04

[0052] The wet resins of Examples 1 to 5 and Comparative Examples 1 to 3 were respectively used to prepare impregnated synthetic leathers according to the following methods:

[0053] 100 parts of wet polyurethane resin, 50 parts of DMF and 10 parts of black color paste are mixed to prepare an impregnation liquid, which is impregnated into a common non-woven fabric with a three-dimensional structure, solidified in water, washed with water, and dried to prepare an impregnated synthetic leather.

[0054] The prepared impregnated synthetic leather was used to bond with ABS plastic parts, and the bonding process was high frequency bonding. The results are shown in Table 2.

[0055] Table 2 shows the performance test of synthetic leather prepared by wet-process polyurethane resin of Examples 1 to 5 and Comparative Examples 1 to 3

[0056] Test items Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Fit fastness 80N 75N 70N 85N 72N 20N ＜5N 30N Lamination temperature (high frequency) 122℃ 125℃ 126℃ 122℃ 120℃ 140℃ 145℃ 122℃ Modulus (hardness) 60 60 65 80 45 62 50 90

[0057] Note: Testing method for bonding fastness: Cut the bonded composite material into strips with a width of 2.5 cm and a length of 12 cm, and use an electronic tensile testing machine (Xinsense 500N tensile testing machine) to test the peel strength (bonding fastness).

[0058] The test method of modulus (hardness) is as follows: pour the resin onto the glass plate, scrape it with a 0.1mm scraper, put the glass plate with the resin mold into an oven at 80°C, bake for 2 hours, take it out, let it stand at room temperature for 1 hour, cut 4 PU strips of 5×12mm along the weft of the film, and set them aside. Measure the thickness of 3 different parts on each sample and take the average value. Select "film test" in the test mode of the tensile machine (Xinsans 500N tensile machine), enter the thickness and width (5mm), clamp the two ends of the sample on the upper and lower clamps of the electronic tensile machine, and start the tensile machine. When the sample breaks, the tensile machine automatically resets. Record the 100% modulus data displayed on the computer (100% modulus is accurate to 0.1MPa), and then multiply this data by 10, which is the modulus (hardness).

[0059] The bonding temperature refers to the heating temperature set by the high-frequency heat sealing machine.

[0060] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

[0061] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

Claims

1. A wet-process polyurethane resin for synthetic leather for laminating ABS plastic parts, characterized in that: Measured by mass percentage, the raw materials of the wet-process polyurethane resin include: Polyester polyol 11~15%; Polyether polyol 3~8%; AS resin 1.5~3.5% Isocyanate 6~8%; Chain extender 1.5~3%; Solvent 65~75%; Terminator 0.01~0.05%; Wherein, the chain extender is 1,3-butanediol; The polyester polyol is a polyester polyol of a neopentyl glycol-adipic acid system; The polyether polyol is polytetramethylene ether diol; The isocyanate is diphenylmethane diisocyanate; The preparation method of the wet polyurethane resin comprises adding polyester polyol, polyether polyol, chain extender, a first part of solvent and isocyanate into a reaction kettle, reacting at 70-80° C. for 0.5-2 hours, then adding AS resin, adding a second part of solvent for dilution when the viscosity reaches a specified value, continuing the reaction until the viscosity reaches a preset value, adding a terminator and a third part of solvent, terminating the reaction, and obtaining the wet polyurethane resin, wherein the first part of solvent accounts for 20-30% of the total amount of the solvent, and the second part of solvent accounts for 10-20% of the total amount of the solvent.

2. The wet-process polyurethane resin for synthetic leather for laminating ABS plastic parts according to claim 1, characterized in that: The number average molecular weight of the polyester polyol is 1500-2500.

3. The wet-process polyurethane resin for synthetic leather for laminating ABS plastic parts according to claim 1, characterized in that: The number average molecular weight of the polyether polyol is 1500-2500.

4. The wet-process polyurethane resin for synthetic leather for laminating ABS plastic parts according to claim 1, characterized in that: The terminator is methanol; and / or the solvent is N,N-dimethylformamide.

5. The wet-process polyurethane resin for synthetic leather for laminating ABS plastic parts according to claim 1, characterized in that: The raw materials of the wet-process polyurethane resin also include one or more of an antioxidant and a catalyst.

6. The wet-process polyurethane resin for synthetic leather for laminating ABS plastic parts according to claim 1, characterized in that: Measured by weight percentage, the raw materials of the wet-process polyurethane resin include: Polyester polyol 11~15%; Polyether polyol 3~8%; AS resin 1.5~3.5% Isocyanate 6~8%; Chain extender 1.5~3%; Solvent 65~75%; Terminator 0.01~0.05%; Antioxidant 0.01~0.05%; Catalyst 0~0.2%.

7. A method for preparing a wet-process polyurethane resin for synthetic leather for laminating ABS plastic parts according to any one of claims 1 to 6, characterized in that: The preparation method comprises adding polyester polyol, polyether polyol, chain extender, the first part of solvent, isocyanate and optional antioxidant into a reaction kettle, reacting at 70-80°C for 0.5-2h, then adding AS resin and optional catalyst, adding the second part of solvent for dilution when the viscosity reaches a specified value, continuing the reaction until the viscosity reaches a preset value, adding a terminator and the third part of solvent, terminating the reaction, and obtaining a wet-process polyurethane resin, wherein the first part of solvent accounts for 20-30% of the total amount of the solvent, and the second part of solvent accounts for 10-20% of the total amount of the solvent.

8. A synthetic leather for bonding to ABS plastic parts, the synthetic leather comprising a base fabric layer and a polyurethane resin layer formed on two surfaces of the base fabric layer by impregnation, the polyurethane resin layer being made of the wet polyurethane resin described in any one of claims 1 to 6, and when the synthetic leather is used for bonding to the ABS plastic part, one of the two surfaces of the synthetic leather is directly bonded to the ABS plastic part.

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