Polyurethane topcoat resin having good bonding force with silicone treatment agent, preparation method and pu leather composite prepared using the same

Abstract

The application relates to the technical field of polyurethane topcoat resins, in particular to a polyurethane topcoat resin with good combination with an organic silicon treating agent, a preparation method and a PU leather composite prepared by using the same. The polyurethane topcoat resin with good combination with the organic silicon treating agent is mainly prepared from polyhydric alcohol, a chain extender, dihydroxy vinyl silicone oil, diisocyanate, a catalyst, an organic solvent, an additive and a terminator; the polyhydric alcohol is at least one of maleic anhydride modified polyester polyhydric alcohol, polyether polyhydric alcohol with a molecular weight of 1000-3000 and polycarbonate polyhydric alcohol; the maleic anhydride modified polyester polyhydric alcohol is mainly prepared from maleic anhydride, adipic acid and low-polarity dihydric alcohol, and the mass of the maleic anhydride is equal to 5-25 wt% of the mass of the adipic acid. The polyurethane topcoat resin prepared by the application has good combination with the surface formed by the organic silicon treating agent, is not prone to falling off, and endows the whole with excellent properties of long-lasting wear resistance, folding resistance, stain resistance and smoothness.

Description

Technical Field

[0001] This application relates to the field of polyurethane surface resin technology, and in particular to a polyurethane surface resin with good bonding with organosilicon treatment agents, a preparation method thereof, and PU leather composite materials prepared therefrom. Background Technology

[0002] Polyurethane resin, due to its high polarity, easily attracts dust and produces poor slipperiness in soft leather, limiting its application in the upholstered furniture leather industry. To achieve better slipperiness, softness is often sacrificed for increased hardness, or a large amount of slippery silicone additives are added. Silicone additives have low surface energy, which can significantly improve surface slipperiness; however, silicone and polyurethane resin have poor compatibility. Over time, silicone gradually precipitates, causing problems such as a hazy leather surface and affecting its performance.

[0003] To address the aforementioned issues, the latest industry practice involves roller-coating a thin layer of vinyl silicone and hydrogen-containing silicone oil onto the surface of synthetic leather. Under the action of a catalyst, this mixture undergoes addition polymerization to form an organosilicon polymer. This method produces synthetic leather with a smooth, soft surface, excellent weather resistance, and avoids issues such as fogging or a decrease in smoothness over time. However, due to the difference in polarity between organosilicon and polyurethane, the above solution suffers from weak adhesion, easily leading to the organosilicon layer peeling off. Therefore, this application provides a polyurethane surface layer resin with good adhesion to organosilicon treatment agents and its preparation method. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a polyurethane surface resin with good adhesion to organosilicon treatment agents, a preparation method thereof, and a PU leather composite material prepared using the same.

[0005] Firstly, the polyurethane surface resin with good adhesion to organosilicon treatment agents provided in this application is achieved through the following technical solution:

[0006] A polyurethane surface resin with good adhesion to organosilicon treatment agents is mainly made of polyol, chain extender, vinyl silicone oil with active groups at both ends, diisocyanate, catalyst, organic solvent, additives, and terminator.

[0007] The diisocyanate is at least one of the diisocyanates with a molecular weight of less than 300 g / mol;

[0008] The polyol is at least one of maleic anhydride modified polyester polyol combined with polyether polyol and polycarbonate polyol with a molecular weight of 1000-3000.

[0009] The chain extender is at least one of a diol containing a double bond with a molecular weight of 76-200 g / mol combined with a saturated diol, a diamine, or an alkanolamine with a molecular weight of 61-200 g / mol;

[0010] The maleic anhydride-modified polyester polyol is mainly prepared from maleic anhydride, adipic acid, and low-polarity diol, and the mass of the maleic anhydride is equal to 5-25 wt% of the mass of the adipic acid.

[0011] The low-polarity diol is at least one of a diol with a molecular weight of 76-200 g / mol and a diol containing a side group; the diol containing a side group is at least one of poly(1,3-propylene glycol), 1,5-pentanediol, 1,2-propylene glycol, and neopentanediol.

[0012] The mass of the catalyst is equal to 10ppm-500ppm of the total mass of the diisocyanate, polyol, and chain extender; the catalyst is an organotin compound.

[0013] The molar ratio of the polyol to the chain extender is controlled at 1:(0.01-0.3);

[0014] The organic solvent includes at least one of acetone, butanone, DMF, and toluene;

[0015] The terminator is a dihydroxy small molecule;

[0016] The vinyl silicone oil with active groups at both ends is at least one of dihydroxy vinyl silicone oil and vinyl-terminated amino silicone oil;

[0017] The additives include at least one of the following: polymerization inhibitors, leveling agents, slip agents, dispersants, adhesion promoters, coupling agents, defoamers, thickeners, antioxidants, UV stabilizers, color pastes, and functional fillers.

[0018] Existing technologies lack polyurethane resins with good adhesion to silicone treatment agents. Typically, reactive silicone treatment agents are used to surface-treat conventional polyurethane surface resins, leading to easy detachment of the surface layer from the silicone treatment layer and poor adhesion. This application addresses this issue by designing a corresponding structure for the polyurethane surface resin, introducing double bonds into the soft and / or hard segments. This allows the hydrogen-containing silicone oil to undergo addition polymerization with these double bonds. Furthermore, the prepared polyurethane resin is hydroxyl-terminated, allowing the hydrogen-containing silicone oil to react with the hydroxyl groups under the action of a catalyst. Additionally, the polyurethane molecule contains vinyl silicone oil, which has good compatibility with the silicone layer. This results in both chemical bonding and similar physical polarity between the polyurethane surface resin and the silicone resin. These multiple aspects contribute to forming a chemically bonded whole, effectively improving the bonding strength between the reactive silicone treatment agent and the polyurethane surface resin, and solving the problem of detachment between the silicone resin and the polyurethane surface layer.

[0019] The polyurethane surface resin formed in this application has good adhesion to the surface formed by the organosilicon treatment agent, and is not easy to fall off, giving the whole surface durable wear resistance, fold resistance, stain resistance and slip-resistant properties.

[0020] Preferably, the organotin compounds include, but are not limited to, at least one of the following: dibutyltin dibutyrate, dimethyltin dibutyrate, dioctyltin dibutyrate, dibutyltin diacetate, dimethyltin diacetate, dibutyltin dilaurate, stannous octanoate, isooctyltin dibutyltin dithioacetate, isooctyltin dimethyltin dithioacetate, isooctyltin dioctyltin dioctanoate, dibutyltin dioctanoate, dioctyltin dioctanoate, dioctyltin dilaurate, and dimethyltin dioleate.

[0021] Preferably, the preparation method of the maleic anhydride modified polyester polyol is as follows: First, maleic anhydride, adipic acid, and low-polarity diol are added to a reaction vessel, and the temperature is raised to carry out the reaction. In the first stage, the vessel temperature is raised to 130-135℃ and held at this temperature for 3 hours; then, the temperature is uniformly raised to 225-230℃ over 4 hours and held for 3.0 hours; then, the temperature at the top of the distillation column is controlled between 101-103℃. As the reaction proceeds, samples are taken to measure the acid value. After the hydroxyl value reaches 30 mg KOH / g, tetrabutyl titanate is added and a vacuum is drawn. Within 4 hours, the pressure inside the reactor is gradually drawn from atmospheric pressure to a relative vacuum of about -0.098 MPa (25 torr). Samples are taken for testing. When the hydroxyl value of the product inside the reactor reaches 17-224 mg KOH / g, the product is qualified. Finally, the reactor is degassed with nitrogen and cooled to 108-110℃. The product is then unloaded and packaged to obtain maleic anhydride polyols with a molecular weight of 500-6500.

[0022] The preparation method of maleic anhydride modified polyester polyol in this application is relatively simple, easy to operate, and easy to realize industrial production, and can ensure the quality of the prepared maleic anhydride modified polyester polyol.

[0023] Preferably, the polyol is composed of maleic anhydride modified polyester polyol with a molecular weight of 2000, polytetrahydrofuran ether diol with a molecular weight of 3000, and polycarbonate diol with a molecular weight of 2000 in a molar ratio of (2-4):(1-4):(1-4).

[0024] Optimized design of polyols can ensure good mechanical properties and weather resistance of polyurethane surface layers.

[0025] Preferably, the chain extender is at least one of 3-allyloxy-1,2-propanediol, 1,4-butenediol, and 1,5-hexadiene-3,4-diol combined with at least one of 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, isophorone diamine, 4,4'-diaminodicyclohexylmethane, and hexamethylenediamine.

[0026] By introducing double bonds into the chain extender, the hydrogen-containing silicone oil in the surface treatment agent will also undergo addition polymerization of the double bonds in the chain extender, thereby improving the adhesion strength between the surface treatment agent and the surface resin.

[0027] Preferably, the chain extender is composed of 1,5-hexadiene-3,4-diol, 1,6-hexanediol, and isophorone diamine in a molar ratio of (1-3):(4-8):(4-8).

[0028] By optimizing the composition and ratio of the chain extender, not only can the bonding strength between the surface treatment agent and the polyurethane surface layer resin be improved, but the mechanical properties of the prepared polyurethane surface layer resin can also be optimized and improved.

[0029] Preferably, the diisocyanate is composed of MDI and HMDI in a molar ratio of (6-8):(2-4).

[0030] Adjusting the molar ratio of MDI and HMDI can improve the heat resistance, anti-yellowing properties, and abrasion resistance of polyurethane surface resin, while also providing good mechanical properties and flexibility.

[0031] Secondly, the method for preparing a polyurethane surface layer resin with good adhesion to organosilicon treatment agents provided in this application is achieved through the following technical solution:

[0032] A method for preparing a polyurethane surface layer resin with good adhesion to organosilicon treatment agents is as follows:

[0033] S1, Preparation of maleic anhydride modified polyester polyol;

[0034] S2, the maleic anhydride-modified polyester polyol prepared in S1 is mixed evenly with the remaining polyols, chain extender, dihydroxyvinyl silicone oil, diisocyanate, catalyst, organic solvent, and additives, and heated to react to form 3-20*10 4 After cps / 25℃, the reaction is terminated with a terminator to obtain the finished polyurethane surface resin.

[0035] The preparation method of the polyurethane surface resin with good adhesion to the organosilicon treatment agent in this application is relatively simple, easy to operate, and easy to realize industrial production and manufacturing, and has good market prospects.

[0036] Thirdly, the PU leather composite material prepared using a polyurethane surface resin with good adhesion to organosilicon treatment agents provided in this application is achieved through the following technical solution:

[0037] A PU leather composite material prepared using a polyurethane surface resin with good adhesion to an organosilicon treatment agent includes a microfiber fabric, the surface of which is coated with a PU surface layer; the PU surface layer is made of the aforementioned polyurethane surface resin with good adhesion to the organosilicon treatment agent; the surface of the PU surface layer facing away from the microfiber fabric is provided with a fold-resistant and smooth layer; the fold-resistant and smooth layer is prepared from an organosilicon resin or a reactive organosilicon treatment agent with good adhesion to the polyurethane resin.

[0038] The reactive organosilicon treatment agent is mainly composed of vinyl silicone oil, hydrogen-containing silicone oil and catalyst;

[0039] The silicone resin with good adhesion to polyurethane resin is made of component A, component B, and platinum catalyst; component A is mainly made of polyol, chain extender, diisocyanate, organic solvent, catalyst, additives, and vinyl silicone oil. The polyol in component A is at least one of maleic anhydride modified polyester polyol, polyether or polycarbonate polyol with a molecular weight of 1000-3000; the maleic anhydride modified polyester polyol in the fold-resistant and slip-resistant layer is the same as the maleic anhydride modified polyester polyol used in the PU surface layer; component B is hydrogen-containing silicone oil; the molar ratio of vinyl in component A to active hydrogen in the hydrogen-containing silicone oil in component B is 1:(1.1-1.3).

[0040] The fold-resistant and slip-resistant layer prepared in this application can be either a commercially available reactive silicone treatment agent or a silicone resin with good adhesion to polyurethane resin. In PU leather composite materials prepared using either of these surface treatment agents, both the PU surface layer and the fold-resistant and slip-resistant layer exhibit excellent adhesion, meaning they are not prone to peeling or detachment, resulting in a long service life and providing good wear resistance, stain resistance, and slip resistance. Compared to commercially available reactive silicone treatment agents, PU leather composite materials prepared using silicone resins with good adhesion to polyurethane resin exhibit superior bonding stability, making them suitable for high-end leather materials or personalized custom products. PU leather composite materials prepared using commercially available reactive silicone treatment agents are suitable for industrial production, with relatively low production costs, and are applicable to fields such as bag leather and shoe leather.

[0041] Preferably, the chain extender in component A is one or a mixture of two or more diols, diamines, or alkanolamines with a molecular weight of 61-200 g / mol; the diisocyanate in component A is one or a mixture of two or more diisocyanates with a molecular weight of less than 300 g / mol; the vinyl silicone oil in component A is one or a mixture of two or more vinyl silicone oils with a vinyl content of 0.09-20 wt%; the hydrogen content of the hydrogen-containing silicone oil in component B is 0.03%-1.60%; and the additives in component A include one or a mixture of two or more antioxidants, matting agents, and light stabilizers.

[0042] A preferred method for preparing PU leather composite material using a polyurethane surface layer resin with good adhesion to the organosilicon treatment agent is as follows:

[0043] S1, Preparation of polyurethane surface resin with good adhesion to organosilicon treatment agent;

[0044] Simultaneously, the preparation of the flexural and slip-resistant silicone resin layer was carried out;

[0045] S2, the polyurethane surface layer resin prepared in S1 with good adhesion to the organosilicon treatment agent is coated on the surface of the microfiber cloth. After being rolled onto the microfiber cloth, it is baked at 150-170℃ for 5-10 minutes to obtain the PU surface layer.

[0046] S3 involves coating the fold-resistant and smooth silicone resin layer prepared in S1 onto the PU surface. After rolling it onto the PU surface, it is baked at 150-170℃ for 5-10 minutes to obtain the finished PU leather composite material.

[0047] The preparation method of the PU leather composite material in this application is relatively simple, easy to operate, and easy to realize industrial production.

[0048] In summary, this application has the following advantages:

[0049] 1. The polyurethane surface resin formed in this application has good adhesion to the surface formed by the organosilicon treatment agent, and it is not easy to fall off, giving the whole a durable wear resistance, fold resistance, stain resistance and slip-resistant properties.

[0050] 2. The preparation method of this application is relatively simple, easy to operate, and easy to realize industrial production and manufacturing. Implementation

[0051] The present application will be further described in detail below with reference to comparative examples and embodiments.

[0052] Preparation Example 1: Maleic anhydride modified polyester polyol is composed of 14g maleic anhydride, 146g adipic acid, 142g neopentyl glycol, 0.02g tetrabutyl titanate, and 0.03g antioxidant 1010.

[0053] Preparation method of maleic anhydride modified polyester polyol:

[0054] S1, maleic anhydride, adipic acid, neopentyl glycol and antioxidant 1010 are added to the reactor and heated to carry out the reaction. In the first stage, the reactor temperature is raised to 135°C and maintained at this temperature for 3.0h. Then, the temperature is raised to 230°C at a constant rate over 4.0h and held for 3.0h.

[0055] S2. Control the temperature at the top of the distillation column between 101-103℃. As the reaction proceeds, take samples to measure the acid value. When the acid value reaches 30mgKOH / g, add tetrabutyl titanate and evacuate the vacuum. Within 4 hours, gradually evacuate the pressure inside the reactor from atmospheric pressure to a relative vacuum of approximately -0.098MPa (25 torr). Take samples for testing. When the hydroxyl value of the product inside the reactor reaches 56.0mgKOH / g, the product is qualified. Break the vacuum in the reactor with nitrogen and cool it to 110℃. Unload and package the product to obtain maleic anhydride polyol with a molecular weight of 2000.

[0056] An organosilicon resin with excellent adhesion to polyurethane surface resin is made from 100g of maleic anhydride modified polyester polyol with a molecular weight of 2000, 76g of MDI, 0.001g of stannous octoate, 0.1g of triphenyl phosphite, 7g of ethylene glycol, and 400g of toluene.

[0057] A method for preparing an organosilicon resin with excellent adhesion to polyurethane surface layer resin is as follows:

[0058] S1. In a reactor, 100g of maleic anhydride polyol, 7g of ethylene glycol, 0.1g of antioxidant, and 400g of toluene were added. The mixture was heated to 45℃ and stirred for 25min. 41g of MDI was added, and the reactor temperature was controlled at 75℃ for 1 hour. A catalyst was added to continue the reaction. When the viscosity reached 5.0×103mPa·s / 25℃, the remaining MDI was added and the reaction was carried out for 40min. The mixture was then discharged to obtain maleic anhydride polyurethane resin with a solid content of 31%.

[0059] S2, mix 15g of maleic anhydride polyurethane resin with a solid content of 31% and 100g of vinyl silicone oil with a vinyl content of 0.098% (provided by Jiangxi Xinjiayi Materials Co., Ltd.) to form material A;

[0060] When using, add 0.001g of platinum catalyst and 21.6g of hydrogen-containing silicone oil (provided by Jiangxi Xinjiayi Materials Co., Ltd.) of component A in S2 and stir at 320rpm. Continue stirring at 320rpm to mix evenly and obtain silicone resin with good bonding force with polyurethane.

[0061] The difference between Preparation Example 2 and Preparation Example 1 is that the maleic anhydride modified polyester polyol is prepared from 28g of maleic anhydride, 146g of adipic acid, 182g of 3-methyl-1,5-pentanediol, 0.02g of tetrabutyl titanate and 0.03g of antioxidant 1010, resulting in a maleic anhydride modified polyester polyol with a molecular weight of 1500.

[0062] An organosilicon resin with excellent adhesion to polyurethane surface resin is made from 100g of maleic anhydride modified polyester polyol with a molecular weight of 1500, 50g of polytetrahydrofuran diol with a molecular weight of 2000, 58.7g of TDI, 67.9g of MDI, 0.001g of stannous octoate, 0.02g of triphenyl phosphite, 15g of ethanolamine, and 500g of toluene.

[0063] A method for preparing an organosilicon resin with excellent adhesion to polyurethane surface layer resin is as follows:

[0064] S1, maleic anhydride polyester polyol, polytetrahydrofuran diol, antioxidant, ethanolamine, and toluene are added to the reactor and heated to 45°C, then stirred for 25 minutes. All TDI is then added, and the reactor temperature is controlled at 85°C for 2 hours. A catalyst is then added to continue the reaction until the viscosity reaches 1.2 × 10⁻⁶. 4 mPa·s / 25℃; add MDI and react for 60 min, then unload to obtain maleic anhydride modified polyurethane resin with a solid content of 36.8%.

[0065] S2, mix 20g of maleic anhydride polyurethane resin and 100g of vinyl silicone oil with a vinyl content of 10% (provided by Jiande Juhe New Material Co., Ltd.) to form material A;

[0066] When using, add 0.001g of platinum catalyst and 31.6g of hydrogen-containing silicone oil B (SHIN-ETSU KF99 hydrogen-containing silicone oil, CAS: 7223-15) to the A material of S2 at a stirring speed of 320rpm. Continue to mix evenly at a stirring speed of 320rpm to obtain silicone resin with good bonding force with polyurethane.

[0067] The difference between Preparation Example 3 and Preparation Example 1 is that the maleic anhydride modified polyester polyol is prepared from 36g of maleic anhydride, 146g of adipic acid, 152g of 2-methyl-1,3-propanediol, 0.02g of tetrabutyl titanate, and 0.03g of antioxidant 1076, resulting in a maleic anhydride modified polyester polyol with a molecular weight of 3000.

[0068] An organosilicon resin with excellent adhesion to polyurethane surface resin is made from 150g of maleic anhydride modified polyester polyol with a molecular weight of 3000, 90g of polypropylene oxide glycol with a molecular weight of 3000, 154.3g of IPDI, 0.003g of dibutyltin dilaurate, 20g of 1,4-butanediol, 420g of toluene, and 0.03g of antioxidant 1024.

[0069] A method for preparing an organosilicon resin with excellent adhesion to polyurethane surface layer resin is as follows:

[0070] S1, add 150g of maleic anhydride polyester polyol, 90g of polypropylene oxide glycol (molecular weight 3000), 20g of 1,4-butanediol, 0.03g of antioxidant, and 420g of toluene to a reactor, heat to 45℃, and stir for 25min; add 67.1g of EPDI, control the reactor temperature at 95℃ and react for 2 hours, add catalyst and continue the reaction until the viscosity reaches 9000mPa·s / 25℃; add 87.2g of IPDI and react for 60min, then discharge to obtain maleic anhydride polyurethane resin with a solid content of 50%;

[0071] S2, mix 25g of maleic anhydride polyurethane resin with a solid content of 50% and 100g of vinyl silicone oil with a vinyl content of 8% (provided by Jiangxi Xinjiayi Materials Co., Ltd.) to form material A;

[0072] When using, add 0.001g of platinum catalyst and 103.9g of hydrogen-containing silicone oil B (provided by Jiangxi Xinjiayi Materials Co., Ltd.) with a hydrogen content of 0.45% to the A material prepared in S2 at a stirring speed of 320rpm. Mix evenly to obtain an organosilicon resin with excellent bonding strength to polyurethane surface resin.

[0073] The difference between Preparation Example 4 and Preparation Example 1 is that the maleic anhydride modified polyester polyol is prepared from 30g of maleic anhydride, 146g of adipic acid, 120g of 1,2-propylene glycol, 0.02g of tetrabutyl titanate, and 0.03g of antioxidant 1076, resulting in a maleic anhydride modified polyester polyol with a molecular weight of 1000.

[0074] An organosilicon resin with excellent adhesion to polyurethane surface resin is made from 200g of maleic anhydride-modified polyester polyol with a molecular weight of 1000, 100g of polycarbonate diol with a molecular weight of 2000, 127g of MDI, 104g of 4,4-dicyclohexylmethane diisocyanate, 0.003g of dibutyltin dilaurate, 10g of neopentyl glycol, 10g of ethylene glycol, 560g of toluene, and 0.03g of triphenyl phosphite.

[0075] A method for preparing an organosilicon resin with excellent adhesion to polyurethane surface layer resin is as follows:

[0076] S1. In a reactor, add 200g of maleic anhydride polyester polyol, 100g of polycarbonate diol, 10g of ethylene glycol, 10g of neopentyl glycol, 0.03g of antioxidant, and 560g of toluene. Heat to 45℃ and stir for 25min. Add 127g of MDI, control the reactor temperature at 75℃ and react for 1 hour. Add catalyst and react until the viscosity reaches 1.1×104mPa·s / 25℃. Add 104g of 4,4-dicyclohexylmethane diisocyanate, react for 60min and discharge to obtain maleic anhydride polyurethane resin with a solid content of 49.6%.

[0077] S2, when 20g of maleic anhydride polyurethane resin with a solid content of 49.6% and 100g of vinyl silicone oil with a vinyl content of 3% (provided by Guangzhou Yusheng New Materials Co., Ltd.) are used to prepare material A, the material A prepared in S2 is mixed evenly with 0.001g of platinum catalyst and 8.24g of hydrogen-containing silicone oil material B with a hydrogen content of 1.60% (provided by Jiangxi Xinjiayi Materials Co., Ltd.) to obtain an organosilicon resin with excellent bonding strength to polyurethane surface resin.

[0078] The difference between Preparation Example 5 and Preparation Example 1 is as follows: 100g of vinyl silicone oil with a vinyl content of 0.098% was prepared as component A, and mixed evenly with 0.001g of platinum catalyst and 16.3g of hydrogen-containing silicone oil with a hydrogen content of 0.03% to obtain a reactive organosilicon treatment agent. In use, it is applied to the surface of synthetic leather by roller coating and then baked at 160°C for 8 minutes.

[0079] The difference between Preparation Example 6 and Preparation Example 2 is that 100g of vinyl silicone oil with a vinyl content of 10% is prepared as material A; when used, it is mixed evenly with 0.001g of platinum catalyst and 31.46g of hydrogen-containing silicone oil with a hydrogen content of 1.60% (material B) to obtain a reactive organosilicon treatment agent.

[0080] The difference between Preparation Example 7 and Preparation Example 3 is that 100g of vinyl silicone oil with a vinyl content of 8% was prepared as Material A; when used, it was mixed evenly with 0.001g of platinum catalyst and 102.56g of hydrogen-containing silicone oil with a hydrogen content of 0.45% (Material B) to obtain a reactive organosilicon treatment agent.

[0081] The difference between Preparation Example 8 and Preparation Example 4 is that 100g of vinyl silicone oil with a vinyl content of 3% was prepared as material A; when used, it was mixed evenly with 0.001g of platinum catalyst and 7.98g of hydrogen-containing silicone oil with a hydrogen content of 1.59% (material B) to obtain a reactive organosilicon treatment agent. Example

[0082] A polyurethane surface resin with good adhesion to organosilicon treatment agents is mainly composed of polyols, chain extenders, vinyl silicone oil with active groups at both ends, diisocyanates, catalysts, organic solvents, additives, and terminators. The diisocyanate is at least one of diisocyanates with a molecular weight of less than 300 g / mol, preferably composed of MDI and HMDI in a molar ratio of (6-8):(2-4).

[0083] The polyol is a combination of maleic anhydride-modified polyester polyol and at least one of polyether polyols or polycarbonate polyols with a molecular weight of 1000-3000. The maleic anhydride-modified polyester polyol is mainly prepared from maleic anhydride, adipic acid, and low-polarity diols, wherein the mass of maleic anhydride is equal to 5-25 wt% of the mass of adipic acid. The low-polarity diol is at least one of diols with a molecular weight of 76-200 g / mol and diols containing side groups. Diols containing side groups are at least one of poly(1,3-propylene glycol), 1,5-pentanediol, 1,2-propylene glycol, and neopentanediol.

[0084] The preparation method of maleic anhydride modified polyester polyol is as follows:

[0085] First, maleic anhydride, adipic acid, and low-polarity diol are added to a reaction vessel and heated to allow the reaction to proceed. In the first stage, the vessel temperature is raised to 130-135℃ and held at this temperature for 3 hours. Then, the temperature is uniformly raised to 225-230℃ over 4 hours and held for 3 hours. The temperature at the top of the distillation column is then controlled between 101-103℃. As the reaction proceeds, samples are taken to measure the acid value. When the acid value reaches 30 mg KOH / g, tetrabutyl titanate is added and a vacuum is applied. Over 4 hours, the pressure inside the vessel is gradually reduced from atmospheric pressure to a relative vacuum of approximately -0.098 MPa (25 torr). Samples are taken for testing. When the hydroxyl value of the product in the vessel reaches 17-224 mg KOH / g, the product is considered qualified. Finally, the reaction vessel is degassed with nitrogen and cooled to 108-110℃. The product is then unloaded and packaged to obtain maleic anhydride polyols with a molecular weight of 500-6500.

[0086] Preferably, the polyol is composed of maleic anhydride modified polyester polyol with a molecular weight of 2000, polytetrahydrofuran ether diol with a molecular weight of 3000, and polycarbonate diol with a molecular weight of 2000 in a molar ratio of (2-4):(1-4):(1-4).

[0087] The chain extender is at least one of a diol containing a double bond with a molecular weight of 76-200 g / mol combined with a saturated diol, diamine, or alkanolamine with a molecular weight of 61-200 g / mol.

[0088] Preferably, the chain extender is at least one of 3-allyloxy-1,2-propanediol, 1,4-butenediol, and 1,5-hexadiene-3,4-diol combined with at least one of 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, isophorone diamine, 4,4'-diaminodicyclohexylmethane, and hexamethylenediamine.

[0089] More preferably, the chain extender is composed of 1,5-hexadien-3,4-diol, 1,6-hexanediol, and isophorone diamine in a molar ratio of (1-3):(4-8):(4-8).

[0090] The mass of the catalyst is equal to 10 ppm to 500 ppm of the total mass of diisocyanate, polyol, and chain extender. The catalyst is an organotin catalyst; in this application, dibutyltin dilaurate or stannous octoate is used.

[0091] The molar ratio of polyol to chain extender is controlled at 1:(0.01-0.3).

[0092] Organic solvents include at least one of acetone, butanone, DMF, and toluene.

[0093] The terminator is a small molecule of dihydroxyl, preferably ethylene glycol.

[0094] Vinyl silicone oil with active groups at both ends is at least one of dihydroxy vinyl silicone oil and vinyl-terminated amino silicone oil.

[0095] Additives include at least one of the following: polymerization inhibitors, leveling agents, slip agents, dispersants, adhesion promoters, coupling agents, defoamers, thickeners, antioxidants, UV stabilizers, color pastes, and functional fillers.

[0096] A method for preparing a polyurethane surface layer resin with good adhesion to organosilicon treatment agents is as follows:

[0097] S1, Preparation of maleic anhydride modified polyester polyol;

[0098] S2, the maleic anhydride-modified polyester polyol prepared in S1 is mixed evenly with the remaining polyols, chain extender, dihydroxyvinyl silicone oil, diisocyanate, catalyst, organic solvent, and additives, and heated to react to form 3-20*10 4 After cps / 25℃, the reaction is terminated with a terminator to obtain the finished polyurethane surface resin.

[0099] A PU leather composite material prepared using a polyurethane surface layer resin with good adhesion to an organosilicon treatment agent includes a microfiber fabric with a PU surface layer laminated to its surface. The PU surface layer is made of the aforementioned polyurethane surface layer resin with good adhesion to the organosilicon treatment agent. The surface of the PU surface layer facing away from the microfiber fabric has a fold-resistant and slip-resistant layer, which is prepared using an organosilicon resin or a reactive organosilicon treatment agent with good adhesion to the polyurethane resin.

[0100] Reactive organosilicon treatment agents are mainly composed of vinyl silicone oil, hydrogen-containing silicone oil, and catalysts.

[0101] The silicone resin with good adhesion to polyurethane resin is made of component A, component B, and a platinum catalyst. Component A is mainly composed of polyol, chain extender, diisocyanate, organic solvent, catalyst, additives, and vinyl silicone oil. The polyol in component A is at least one of maleic anhydride-modified polyester polyol, polyether polyol with a molecular weight of 1000-3000, or polycarbonate polyol. The maleic anhydride-modified polyester polyol in the flexural and slip-resistant layer is the same as that used in the PU surface layer.

[0102] Component B is specifically hydrogen-containing silicone oil, and the molar ratio of vinyl groups in component A to active hydrogen in component B hydrogen-containing silicone oil is 1:(1.1-1.3).

[0103] The chain extender in component A is one or a mixture of two or more diols, diamines, or alkanolamines with a molecular weight of 61–200 g / mol. The diisocyanate in component A is one or a mixture of two or more diisocyanates with a molecular weight less than 300 g / mol. The vinyl silicone oil in component A is one or a mixture of two or more vinyl silicone oils with a vinyl content of 0.09–20 wt%. The additives in component A include one or a mixture of two or more antioxidants, matting agents, and light stabilizers. The hydrogen content of the hydrogen-containing silicone oil in component B is 0.03%–1.60%.

[0104] A method for preparing a PU leather composite material using a polyurethane surface layer resin with good adhesion to organosilicon treatment agents is as follows:

[0105] S1, Preparation of polyurethane surface resin with good adhesion to organosilicon treatment agent;

[0106] Simultaneously, the preparation of the flexural and slip-resistant silicone resin layer was carried out;

[0107] S2, the polyurethane surface layer resin prepared in S1 with good adhesion to the organosilicon treatment agent is coated on the surface of the microfiber cloth. After being rolled onto the microfiber cloth, it is baked at 150-170℃ for 5-10 minutes to obtain the PU surface layer.

[0108] S3 involves coating the fold-resistant and smooth silicone resin layer prepared in S1 onto the PU surface. After rolling it onto the PU surface, it is baked at 150-170℃ for 5-10 minutes to obtain the finished PU leather composite material.

[0109] Example 1: A polyurethane surface resin with good adhesion to organosilicon treatment agents is composed of 1 mol MDI (Yantai Wanhua), 0.25 mol HMDI (Yantai Wanhua), 0.1 mol of self-made maleic anhydride modified polyester polyol with a molecular weight of 2000, 0.05 mol of polyether polyol-polytetrahydrofuran diol with a molecular weight of 3000 (from Hyosung Group), 0.05 mol of polycarbonate diol with a molecular weight of 2000 (from Tosoh Japan, model: NIPPOLLAN 964, hydroxyl value 56.0±3; main component 1,6-HDO content 50%), 0.5 mol of 1,4-butanediol, 0.5 mol of 1,6-hexanediol, and 0.06 mol of dihydroxyvinyl silicone oil (Anhui Aiyota Silicone Oil Co., Ltd., hydroxyl-terminated methyl vinyl silicone oil IOTA). It is made from 1203V (hydroxyl content: ≥6.0%, vinyl content: 6.5-7.5 mol%), 200g DMF, 600g toluene, 2g ethylene glycol, 0.28g stannous octoate, 2g antioxidant 1010, and 0.5g antioxidant 168.

[0110] The maleic anhydride-modified polyester polyol with a molecular weight of 2000 is composed of 14g maleic anhydride, 146g adipic acid, 142g neopentyl glycol, 0.02g tetrabutyl titanate, and 0.03g antioxidant 1010.

[0111] The preparation method of maleic anhydride-modified polyester polyol with a molecular weight of 2000 is as follows:

[0112] S1, maleic anhydride, adipic acid, neopentyl glycol and antioxidant 1010 are added to the reactor and heated to carry out the reaction. In the first stage, the reactor temperature is raised to 135°C and held at this temperature for 3 hours. Then, the temperature is raised to 230°C at a constant rate over 4 hours and held for 3.0 hours.

[0113] S2. Control the temperature at the top of the distillation column between 101-103℃. As the reaction proceeds, take samples to measure the acid value. When the acid value reaches 30mgKOH / g, add tetrabutyl titanate and evacuate the vacuum. Within 4 hours, gradually evacuate the pressure inside the reactor from atmospheric pressure to a relative vacuum of approximately -0.098MPa (25 torr). Take samples for testing. When the hydroxyl value of the product inside the reactor reaches 56.0mgKOH / g, the product is qualified. Break the vacuum in the reactor with nitrogen and cool it to 110℃. Unload and package the product to obtain maleic anhydride polyol with a molecular weight of 2000.

[0114] A method for preparing a polyurethane surface layer resin with good adhesion to organosilicon treatment agents is as follows:

[0115] S1, Preparation of maleic anhydride modified polyester polyol: Refer to the above method for preparing maleic anhydride modified polyester polyol with a molecular weight of 2000.

[0116] In step S2, the maleic anhydride-modified polyester polyol prepared in step S1, with precise measurements, is mixed with polytetrahydrofuran diol, polycarbonate diol, 1,4-butanediol, hydroxyl-terminated methyl vinyl silicone oil IOTA 1203V, MDI, HMDI, stannous octoate, DMF, toluene, antioxidant 1010, and antioxidant 168. The mixture is then reacted at 80°C for 3.60 hours. 1,6-hexanediol is gradually added to the reactor, and the mixture is heated to react with 12–16 x 10⁻⁶ ppm. 4 After 25℃, the reaction was terminated with ethylene glycol for 30 minutes to obtain the finished polyurethane surface resin.

[0117] A method for preparing a PU leather composite material using a polyurethane surface layer resin with good adhesion to organosilicon treatment agents is as follows:

[0118] S1, Preparation of polyurethane surface resin with good adhesion to organosilicon treatment agent, see the above-mentioned preparation method of polyurethane surface resin with good adhesion to organosilicon treatment agent.

[0119] Simultaneously, an organosilicon resin with good bonding strength to polyurethane resin was prepared, see Preparation Example 1;

[0120] S2, the polyurethane surface layer resin prepared in S1 with good adhesion to the organosilicon treatment agent is coated on the surface of microfiber cloth (provided by Hexin Kuraray Microfiber Leather (Jiaxing) Co., Ltd.). After being rolled onto the microfiber cloth, it is baked at 160℃ for 8 minutes to obtain the PU surface layer.

[0121] S3 involves coating the PU surface layer prepared in S2 with an organosilicon resin prepared in S1 that has good adhesion to polyurethane resin. After rolling the resin onto the PU surface layer, the product is baked at 150°C for 10 minutes to obtain the finished PU leather composite material.

[0122] The difference between Example 2 and Example 1 is that Example 2 uses dihydroxy vinyl silicone oil (custom-made by Anhui Aiyota Silicone Oil Co., Ltd., the hydroxyl-terminated methyl vinyl silicone oil contains 8.5-9.0 mol% vinyl content).

[0123] The difference between Example 3 and Example 1 is that Example 3 uses dihydroxy vinyl silicone oil (custom-made by Anhui Aiyota Silicone Oil Co., Ltd., the hydroxyl-terminated methyl vinyl silicone oil contains 5.0-6.0 mol% vinyl content).

[0124] The difference between Example 4 and Example 1 is that Example 4 uses the silicone resin with good bonding strength with polyurethane resin, which was used in Example 2.

[0125] The difference between Example 5 and Example 1 is that Example 5 uses the silicone resin with good bonding strength with polyurethane resin, which was used in Example 3.

[0126] The difference between Example 6 and Example 1 is that Example 6 uses the silicone resin with good bonding strength with polyurethane resin, which was used in Example 4.

[0127] The difference between Example 7 and Example 1 is that the flexural slip layer is prepared using a reactive organosilicon treatment agent. The reactive organosilicon treatment agent used in Example 5 is employed.

[0128] The difference between Example 8 and Example 1 is that the flexural slip layer is prepared using a reactive organosilicon treatment agent. The reactive organosilicon treatment agent used in Example 6 is employed.

[0129] The difference between Example 9 and Example 1 is that the flexural slip layer is prepared using a reactive organosilicon treatment agent. The reactive organosilicon treatment agent used in Example 7 is employed.

[0130] The difference between Example 10 and Example 1 is that the flexural slip layer is prepared using a reactive organosilicon treatment agent. The reactive organosilicon treatment agent used in Preparation Example 8 is employed.

[0131] The difference between Example 11 and Example 1 is that: a polyurethane surface resin with good adhesion to the organosilicon treatment agent is made from 1 mol of MDI, 0.25 mol of HMDI, 0.06 mol of maleic anhydride modified polyester polyol with a molecular weight of 2000, 0.08 mol of polyether polyol-polytetrahydrofuran diol with a molecular weight of 3000, 0.08 mol of polycarbonate diol with a molecular weight of 2000, 0.2 mol of 1,5-hexadiene-3,4-diol, 0.4 mol of 1,4-butanediol, 0.4 mol of 1,6-hexanediol, 0.06 mol of dihydroxyvinyl silicone oil, 240 g of DMF, 640 g of toluene, 2 g of ethylene glycol, 0.32 g of dibutyltin dilaurate, 2 g of antioxidant 1010, and 0.5 g of antioxidant 168.

[0132] The difference between Example 12 and Example 1 is that: a polyurethane surface resin with good adhesion to the organosilicon treatment agent is made from 1 mol of MDI, 0.25 mol of HMDI, 0.12 mol of maleic anhydride modified polyester polyol with a molecular weight of 2000, 0.08 mol of polyether polyol-polytetrahydrofuran diol with a molecular weight of 3000, 0.2 mol of 1,5-hexadiene-3,4-diol, 0.4 mol of 1,4-butanediol, 0.4 mol of 1,6-hexanediol, 0.06 mol of dihydroxyvinyl silicone oil, 200 g of DMF, 660 g of toluene, 2 g of ethylene glycol, 0.30 g of stannous octoate, 2 g of antioxidant 1010, and 0.5 g of antioxidant 168.

[0133] The difference between Example 13 and Example 1 is that: a polyurethane surface resin with good adhesion to the organosilicon treatment agent is made from 1 mol of MDI, 0.25 mol of HMDI, 0.06 mol of maleic anhydride modified polyester polyol with a molecular weight of 2000, 0.08 mol of polyether polyol-polytetrahydrofuran diol with a molecular weight of 3000, 0.08 mol of polycarbonate diol with a molecular weight of 2000, 0.2 mol of 1,5-hexadiene-3,4-diol, 0.4 mol of 1,4-butanediol, 0.4 mol of 1,6-hexanediol, 0.06 mol of diaminovinyl silicone oil, 200 g of DMF, 650 g of toluene, 2.0 g of ethylene glycol, 0.30 g of dibutyltin dilaurate, 2 g of antioxidant 1010, and 0.5 g of antioxidant 168.

[0134] The difference between Example 14 and Example 1 is that: a polyurethane surface resin with good adhesion to the organosilicon treatment agent is made from 1 mol of MDI, 0.25 mol of HMDI, 0.08 mol of maleic anhydride modified polyester polyol with a molecular weight of 2000, 0.06 mol of polyether polyol-polytetrahydrofuran diol with a molecular weight of 3000, 0.06 mol of polycarbonate diol with a molecular weight of 2000, 0.1 mol of 1,5-hexadiene-3,4-diol, 0.45 mol of 1,4-butanediol, 0.45 mol of 1,6-hexanediol, 0.06 mol of diaminovinyl silicone oil, 240 g of DMF, 620 g of toluene, 2.0 g of ethylene glycol, 0.32 g of dibutyltin dilaurate, 2 g of antioxidant 1010, and 0.5 g of antioxidant 168.

[0135] The difference between Example 16 and Example 1 is that: a polyurethane surface resin with good adhesion to the organosilicon treatment agent is made from 1 mol of MDI, 0.25 mol of HMDI, 0.08 mol of maleic anhydride modified polyester polyol with a molecular weight of 2000, 0.06 mol of polyether polyol-polytetrahydrofuran diol with a molecular weight of 3000, 0.06 mol of polycarbonate diol with a molecular weight of 2000, 0.3 mol of 1,5-hexadiene-3,4-diol, 0.35 mol of 1,4-butanediol, 0.35 mol of 1,6-hexanediol, 0.06 mol of diaminovinyl silicone oil, 200 g of DMF, 650 g of toluene, 2.0 g of ethylene glycol, 0.28 g of dibutyltin dilaurate, 2 g of antioxidant 1010, and 0.5 g of antioxidant 168.

[0136] The difference between Example 16 and Example 1 is that: a polyurethane surface resin with good adhesion to the organosilicon treatment agent is made from 1 mol of MDI, 0.25 mol of HMDI, 0.08 mol of maleic anhydride modified polyester polyol with a molecular weight of 2000, 0.06 mol of polyether polyol-polytetrahydrofuran diol with a molecular weight of 3000, 0.06 mol of polycarbonate diol with a molecular weight of 2000, 0.3 mol of 1,5-hexadiene-3,4-diol, 0.3 mol of 1,4-butanediol, 0.30 mol of 1,6-hexanediol, 0.1 mol of isophorone diamine, 0.06 mol of diaminovinyl silicone oil, 200 g of DMF, 650 g of toluene, 2.0 g of ethylene glycol, 0.28 g of dibutyltin dilaurate, 2 g of antioxidant 1010, and 0.5 g of antioxidant 168. The difference between Example 17 and Example 1 is that the maleic anhydride modified polyester polyol with a molecular weight of 2000 is replaced with a maleic anhydride modified polyester polyol with a molecular weight of 3000.

[0137] The maleic anhydride-modified polyester polyol with a molecular weight of 3000 is prepared from 36g of maleic anhydride, 146g of adipic acid, 152g of 2-methyl-1,3-propanediol, 0.02g of tetrabutyl titanate, and 0.03g of antioxidant 1076.

[0138] The preparation method of maleic anhydride-modified polyester polyol with a molecular weight of 3000 is as follows:

[0139] S1, maleic anhydride, adipic acid, 2-methyl-1,3-propanediol and antioxidant 1076 are added to the reactor and heated to carry out the reaction. In the first stage, the reactor temperature is raised to 135°C and held at this temperature for 3 hours. Then, the temperature is raised to 230°C at a constant rate over the next 4 hours and held for 3.0 hours.

[0140] S2. Control the temperature at the top of the distillation column between 101-103℃. As the reaction proceeds, take samples to measure the acid value. When the acid value reaches 30mgKOH / g, add tetrabutyl titanate and evacuate the vacuum. Within 4 hours, gradually evacuate the pressure inside the reactor from atmospheric pressure to a relative vacuum of approximately -0.098MPa (25 torr). Take samples for testing. When the hydroxyl value of the product inside the reactor reaches 37.4±2.0mgKOH / g, the product is qualified. Break the vacuum in the reactor with nitrogen and cool it to 110℃. Unload and package the product to obtain maleic anhydride polyol with a molecular weight of 3000.

[0141] The difference between Example 18 and Example 1 is that the maleic anhydride modified polyester polyol with a molecular weight of 2000 is replaced with a maleic anhydride modified polyester polyol with a molecular weight of 1000.

[0142] The maleic anhydride-modified polyester polyol with a molecular weight of 1000 is prepared from 30g of maleic anhydride, 146g of adipic acid, 120g of 1,2-propylene glycol, 0.02g of tetrabutyl titanate, and 0.03g of antioxidant 1076.

[0143] The preparation method of maleic anhydride-modified polyester polyol with a molecular weight of 1000 is as follows:

[0144] S1, maleic anhydride, adipic acid, 1,2-propanediol and antioxidant 1076 are added to the reactor and heated to carry out the reaction. In the first stage, the reactor temperature is raised to 135°C and held at this temperature for 3 hours. Then, the temperature is raised to 230°C at a constant rate over the next 4 hours and held for 3.0 hours.

[0145] S2. Control the temperature at the top of the distillation column between 101-103℃. As the reaction proceeds, take samples to measure the acid value. When the acid value reaches 30mgKOH / g, add tetrabutyl titanate and evacuate the vacuum. Within 4.0h, gradually evacuate the pressure inside the reactor from atmospheric pressure to a relative vacuum of approximately -0.098MPa (25tor). Take samples for testing. When the hydroxyl value of the product inside the reactor reaches 112±3mgKOH / g, the product is qualified. Break the vacuum in the reactor with nitrogen and cool it to 110℃. Unload and package the product to obtain maleic anhydride polyol with a molecular weight of 1000.

[0146] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not contain dihydroxyvinyl silicone oil and uses conventional polyester polyols. Specifically, a polyurethane surface resin with good adhesion to organosilicon treatment agents is made from 1 mol of MDI, 0.25 mol of HMDI, 0.12 mol of a polyester polyol with a molecular weight of 2000—polyhexyl adipate diol (CAS: 25212-06-0), 0.052 mol of a polyether polyol with a molecular weight of 3000—polytetrahydrofuran diol, 0.054 mol of a polycarbonate diol with a molecular weight of 2000, 0.522 mol of 1,4-butanediol, 0.53 mol of 1,6-hexanediol, 200 g of DMF, 600 g of toluene, 2 g of ethylene glycol, 0.28 g of stannous octoate, 2 g of antioxidant 1010, and 0.5 g of antioxidant 168. Furthermore, the fold-resistant and slip-resistant layer uses the silicone resin with good adhesion to polyurethane resin, as described in Preparation Example 5.

[0147] The difference between Comparative Example 2 and Comparative Example 1 is that Comparative Example 2 uses an organosilicon resin with good bonding strength to polyurethane resin, as used in Preparation Example 6.

[0148] The difference between Comparative Example 3 and Comparative Example 1 is that Comparative Example 3 uses an organosilicon resin with good bonding strength to polyurethane resin, as used in Preparation Example 7.

[0149] The difference between Comparative Example 4 and Comparative Example 1 is that Comparative Example 4 uses an organosilicon resin with good bonding strength to polyurethane resin, as used in Preparation Example 8.

[0150] ① Test method for flexural endurance: After being placed in an environment of 80℃ and 75% humidity for 400 hours, it is then placed in an environment of -20℃ and bent until cracking, and the number of bending times (ten thousand times) is recorded.

[0151] ② The method for testing the abrasion resistance of folded edges is as follows:

[0152] I. Test objective: To test the wear resistance of the sample under a certain external force.

[0153] II. Equipment: PK-237 Double Hammer Electric Friction Decolorization Tester

[0154] III. Operating Procedures:

[0155] 3-1 Sampling: Measure a 185mm*55mm sample and cut it out;

[0156] 3-2 Sample clamping: Fold the sample in half and fix it in the middle of the clamp;

[0157] 3-3 Replace the friction cloth: Replace the friction cloth on the friction head of the equipment, and lower the friction head so that the sample folded edge is in the middle position of the friction head;

[0158] 3-4: Start the test:

[0159] 3-4-1 Connect the power supply and turn on the instrument power switch;

[0160] 3-4-2 Set the number of tests on the control panel according to the testing requirements;

[0161] 3-4-3 Equipment reset to zero;

[0162] Start testing with step 3-4-4. Once the set number of tests is reached, the machine will automatically stop or, if the sample is damaged during testing, press the stop button to stop the machine.

[0163] 3-5 Result Interpretation: Remove the test sample and interpret the test results;

[0164] IV. Precautions

[0165] 4-1 During the sample clamping process, the folded edge of the sample must coincide exactly with the center line of the clamp;

[0166] 4-2 The friction cloth must be replaced after each test;

[0167] 4-3 The results should be judged in a well-lit environment, and if necessary, under artificial light.

[0168] ③ Stain resistance rating test: The stain resistance rating is tested according to GMW 3402.

[0169] Table 1 shows the test parameters of the PU leather materials used in Examples 1-8.

[0170] -20℃ flexural strength (10,000 cycles) Wear resistance of the folded edge (number of wear cycles) Stain resistance rating Example 1 >100,000 times >100,000 times ≥8 levels Example 2 >100,000 times >100,000 times ≥8 levels Example 3 >100,000 times >100,000 times ≥8 levels Example 4 >100,000 times >100,000 times ≥8 levels Comparative Example 1 30,000 times 50,000 ≥8 levels Comparative Example 2 60,000 times 70,000 ≥8 levels Comparative Example 3 70,000 times 80,000 ≥8 levels Comparative Example 4 70,000 times 70,000 ≥8 levels

[0171] Note: The PU leather material prepared in Examples 1-8 is prepared by rolling the silicone resin with excellent adhesion to the polyurethane surface resin onto the surface of synthetic leather (provided by Zhejiang Hexin New Material Co., Ltd., model 5BVF-AM9-38LS-FOJ9-136) and then baking it at 160°C for 8 minutes.

[0172] As can be seen from the preparation examples 1-8 and Table 1, the silicone resin surface treatment layer prepared in this application has excellent adhesion to the polyurethane surface resin, is not easy to fall off or peel off, has a relatively long service life, and can achieve good folding resistance, wear resistance, stain resistance and smoothness.

[0173] Table 2 shows the test parameters of the PU leather composite materials in Examples 1-18 and Comparative Examples 1-4.

[0174]

[0175]

[0176] As can be seen from Examples 1-18 and Comparative Examples 1-4, and Table 2, the PU surface layer formed by the polyurethane surface layer resin prepared in this application has good adhesion to the surface treatment layer formed by commercially available conventional organosilicon treatment agents (Preparation Examples 5-8), and is not prone to peeling off, thus imparting durable wear resistance, fold resistance, stain resistance, and slip-resistant properties to the overall surface. PU leather composite materials prepared with commercially available reactive organosilicon treatment agents are suitable for industrial production, have relatively low production costs, and are applicable to fields such as bag leather and shoe leather.

[0177] As can be seen from Examples 1-18 and Comparative Examples 1-4 and Table 1-2, the PU surface layer formed by the polyurethane surface layer resin prepared in this application has excellent bonding strength with the surface treatment layer formed by the organosilicon treatment agent (Preparation Examples 1-4) prepared in this application, resulting in a long service life, good weather resistance, and giving the whole a more durable wear resistance, fold resistance, stain resistance, and slip resistance.

[0178] To test the difference in flexural endurance between commercially available conventional silicone treatment agents (Preparation Examples 5-8) and silicone resins with excellent adhesion to polyurethane topcoat resins (Preparation Examples 1-4), flexural endurance was further tested in Examples 1 and 7. The number of flexural cycles Q was used in the flexural endurance test. MAX The number of folding cycles observed at the point of cracking in the PU leather composite material is given. The experiment shows that the number of folding cycles Q in Example 1 is... MAX Cracking was observed after up to 350,000 cycles, while the flexural strength Q of Example 7 was [missing information]. MAX Cracking was observed after 200,000 cycles, indicating that the PU surface layer formed by the polyurethane surface layer resin prepared in this application has a better bonding force with the surface treatment layer formed by the organosilicon treatment agent (preparation examples 1-4) prepared in this application. However, the overall production cost is relatively high, making it suitable for high-end leather materials or personalized products made by private customization.

[0179] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A polyurethane surface resin with good adhesion to organosilicon treatment agents, characterized in that: It is mainly composed of polyols, chain extenders, vinyl silicone oil with active groups at both ends, diisocyanates, catalysts, organic solvents, additives, and terminators; The diisocyanate is at least one of the diisocyanates with a molecular weight of less than 300 g / mol; The polyol is a combination of maleic anhydride modified polyester polyol and at least one of polyether polyol and polycarbonate polyol with a molecular weight of 1000-3000 g / mol. The chain extender is at least one of a diol containing a double bond with a molecular weight of 76-200 g / mol combined with a saturated diol, a diamine, or an alkanolamine with a molecular weight of 61-200 g / mol; The maleic anhydride-modified polyester polyol is mainly prepared from maleic anhydride, adipic acid, and low-polarity diols, wherein the mass of the maleic anhydride is equal to 5-25 wt% of the mass of the adipic acid. The low-polarity diol is at least one of a diol with a molecular weight of 76-200 g / mol and a diol containing a side group; the diol containing a side group is at least one of 1,2-propanediol and neopentyl glycol. The mass of the catalyst is equal to 10ppm-500ppm of the total mass of the diisocyanate, polyol, and chain extender; the catalyst is an organotin compound. The molar ratio of the polyol to the chain extender is controlled at 1:(0.01-0.3). The organic solvent includes at least one of acetone, butanone, DMF, and toluene; The terminator is a dihydroxy small molecule; The vinyl silicone oil with active groups at both ends is at least one of dihydroxy vinyl silicone oil and vinyl-terminated amino silicone oil; The additives include at least one of the following: polymerization inhibitors, leveling agents, slip agents, dispersants, adhesion promoters, coupling agents, defoamers, thickeners, antioxidants, UV stabilizers, color pastes, and functional fillers.

2. The polyurethane surface resin with good adhesion to organosilicon treatment agent according to claim 1, characterized in that: The preparation method of the maleic anhydride modified polyester polyol is as follows: First, maleic anhydride, adipic acid, and low-polarity diol are added to a reaction vessel and heated to carry out the reaction. In the first stage, the vessel temperature is raised to 130-135℃ and held at this temperature for 3 hours. Then, the temperature is uniformly raised to 225-230℃ over 4 hours and held for 3 hours. Then, the temperature at the top of the distillation column is controlled between 101-103℃. As the reaction proceeds, samples are taken to measure the acid value. When the acid value reaches 30mgKOH / g, tetrabutyl titanate is added and a vacuum is drawn. Over 4 hours, the pressure inside the vessel is gradually drawn from atmospheric pressure to a relative vacuum of about -0.098MPa. Samples are taken for testing. When the hydroxyl value of the product in the vessel reaches 17-224mgKOH / g, the product is qualified. Finally, the reaction vessel is degassed with nitrogen and cooled to 108-110℃. The product is unloaded and packaged to obtain a maleic anhydride modified polyester polyol with a molecular weight of 500-6500g / mol.

3. The polyurethane surface resin with good adhesion to organosilicon treatment agent according to claim 2, characterized in that: The polyol is composed of maleic anhydride modified polyester polyol with a molecular weight of 2000 g / mol, polytetrahydrofuran ether diol with a molecular weight of 3000 g / mol, and polycarbonate diol with a molecular weight of 2000 g / mol in a molar ratio of (2-4):(1-4):(1-4).

4. The polyurethane surface resin with good adhesion to organosilicon treatment agent according to claim 1, characterized in that: The chain extender is at least one of 3-allyloxy-1,2-propanediol, 1,4-butenediol, and 1,5-hexadiene-3,4-diol, combined with at least one of 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, isophorone diamine, and 4,4'-diaminodicyclohexylmethane.

5. The polyurethane surface resin with good adhesion to organosilicon treatment agent according to claim 4, characterized in that: The chain extender is composed of 1,5-hexadiene-3,4-diol, 1,6-hexanediol, and isophorone diamine in a molar ratio of (1-3):(4-8):(4-8).

6. The polyurethane surface resin with good adhesion to organosilicon treatment agent according to claim 1, characterized in that: The diisocyanate is composed of MDI and HMDI in a molar ratio of (6-8):(2-4).

7. A method for preparing a polyurethane surface layer resin with good adhesion to an organosilicon treatment agent as described in any one of claims 1-6, characterized in that: Includes the following steps: S1, Preparation of maleic anhydride modified polyester polyol; S2, the maleic anhydride-modified polyester polyol prepared in S1 is mixed evenly with the remaining polyols, chain extender, dihydroxyvinyl silicone oil, diisocyanate, catalyst, organic solvent, and additives, and heated to react to form 3-20*10 4 After cps / 25℃, the reaction is terminated with a terminator to obtain the finished polyurethane surface resin.

8. A PU leather composite material prepared using any one of the polyurethane surface layer resins with good bonding strength to the organosilicon treatment agent as described in claims 1-6, characterized in that: The PU leather composite material includes microfiber fabric, the surface of which is coated with a PU surface layer; the PU surface layer is made of polyurethane surface layer resin with good adhesion to the organosilicon treatment agent as described in any one of claims 1-6; the surface of the PU surface layer facing away from the microfiber fabric is coated with a fold-resistant and smooth layer; the fold-resistant and smooth layer is prepared from an organosilicon resin or a reactive organosilicon treatment agent with good adhesion to the polyurethane resin; the reactive organosilicon treatment agent is mainly composed of vinyl silicone oil, hydrogen-containing silicone oil, and a catalyst; the organosilicon resin with good adhesion to the polyurethane resin is made of component A, component B, and a platinum catalyst; component A is mainly composed of polyol, chain extender, diisocyanate, organic solvent, catalyst, additives, and vinyl silicone oil. The polyol in component A is at least one of maleic anhydride-modified polyester polyol, polyether or polycarbonate polyol with a molecular weight of 1000-3000 g / mol; the maleic anhydride-modified polyester polyol in the flexural and slip-resistant layer is the same as the maleic anhydride-modified polyester polyol used in the PU surface layer; component B is hydrogen-containing silicone oil; the molar ratio of vinyl in component A to active hydrogen in the hydrogen-containing silicone oil in component B is 1:(1.1-1.3).

9. A PU leather composite material prepared using a polyurethane surface layer resin with good adhesion to an organosilicon treatment agent according to claim 8, characterized in that: The chain extender in component A is one or a mixture of two or more diols, diamines, or alkanolamines with a molecular weight of 61-200 g / mol; the diisocyanate in component A is one or a mixture of two or more diisocyanates with a molecular weight of less than 300 g / mol; the vinyl silicone oil in component A is one or a mixture of two or more vinyl silicone oils with a vinyl content of 0.09-20 wt%; the hydrogen content of the hydrogen-containing silicone oil in component B is 0.03%-1.60%; the additives in component A include one or a mixture of two or more antioxidants, matting agents, and light stabilizers.

10. A PU leather composite material prepared using a polyurethane surface layer resin with good bonding strength to an organosilicon treatment agent according to claim 8, characterized in that: The preparation method is as follows: S1, Preparation of polyurethane surface resin with good adhesion to organosilicon treatment agent; Simultaneously, the preparation of the flexural and slip-resistant silicone resin layer was carried out; S2, the polyurethane surface layer resin prepared in S1 with good adhesion to the organosilicon treatment agent is coated on the surface of the microfiber cloth. After being rolled onto the microfiber cloth, it is baked at 150-170℃ for 5-10 minutes to obtain the PU surface layer. S3 involves coating the fold-resistant and smooth silicone resin layer prepared in S1 onto the PU surface. After rolling it onto the PU surface, it is baked at 150-170℃ for 5-10 minutes to obtain the finished PU leather composite material.

Images