Polyurethane film, preparation method and application thereof, and insole

Abstract

The invention discloses a polyurethane film, a preparation method and application thereof and an insole, and relates to the field of high polymer material membranes.The preparation method of the polyurethane film comprises the steps that a polyurethane prepolymer, a compound containing reactive hydrogen, a chain extender and a catalyst are mixed and coated on the surface of a base material through a chemical liquid phase deposition method, wherein the polyurethane prepolymer, the compound containing reactive hydrogen and the chain extender are subjected to a curing reaction under the action of the catalyst, and the polyurethane film is formed on the surface of the base material. The problems that the spray head is blocked, the film uniformity is poor, and a base material is damaged by high temperature can be effectively solved.

Description

Technical Field

[0001] The present invention relates to the field of polymer material membranes, and particularly to a polyurethane membrane, a preparation method thereof, uses thereof, and insoles. The polyurethane membrane described herein has both wear resistance and anti-slip performance and can be used in the fields of clothing, shoes, hats, and textiles. Background Art

[0002] Polyurethane membrane (PU membrane) is a common membrane layer and is widely used in various fields. For example, in the fields of clothing, shoes, and hats, it can be used as a coating for woven fabrics. After coating, the fabric feels plump, soft, and elastic, with a smooth and comfortable touch, and can also enhance the wear resistance experience of specific parts. Especially in the insole manufacturing field, PU membranes can be applied to improve the comfort, durability, anti-slip performance, etc. of insoles.

[0003] Currently, in the insole manufacturing field, the production process of PU membranes mainly uses physical liquid phase deposition method (PLD, Physical Liquid Deposition). Its basic principle is to melt the polyurethane material by high-temperature heating and then spray the molten polyurethane on the surface of the substrate (such as the sole of shoes, backpacks) through a nozzle. However, this process still has the following problems in practical applications:

[0004] (1) When the molten polyurethane material is sprayed, it is easy to agglomerate, forming relatively large spray particles, which are more likely to block the nozzle, resulting in an unstable spraying process, poor film uniformity, affecting the appearance and performance of the product, and even causing production interruption.

[0005] (2) The temperature required for melting polyurethane is relatively high, which may damage the substrate. For example, high-temperature spraying may burn out the sole, midsole fabric, etc. of shoes.

[0006] Therefore, there is an urgent need in the art to develop a preparation method for PU membranes to overcome the above problems. Summary of the Invention

[0007] The object of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a polyurethane membrane, a preparation method thereof, uses thereof, and insoles, which can effectively solve the problems of nozzle blockage, poor film uniformity, and high-temperature damage to the substrate material.

[0008] To achieve the above object, the present invention provides the following technical solutions.

[0009] In a first aspect of the present invention, a preparation method of a polyurethane membrane is provided. The preparation method includes: mixing a polyurethane prepolymer, a compound containing active hydrogen, a chain extender, and a catalyst by chemical liquid phase deposition method and coating the mixture on the surface of a substrate. Among them, the polyurethane prepolymer, the compound containing active hydrogen, and the chain extender undergo a curing reaction under the action of the catalyst and form the polyurethane membrane on the surface of the substrate.

[0010] In some embodiments of the first aspect, the method of coating the surface of a substrate by mixing a polyurethane prepolymer, a compound containing active hydrogen, a chain extender, and a catalyst through chemical liquid deposition includes: spraying the mixture of the polyurethane prepolymer, the compound containing active hydrogen, the chain extender, and the catalyst onto the surface of the substrate.

[0011] In some embodiments of the first aspect, the method of spraying after mixing the polyurethane prepolymer, the compound containing active hydrogen, the chain extender, and the catalyst includes: uniformly mixing the compound containing active hydrogen, the chain extender, and the catalyst to obtain a mixture; mixing the polyurethane prepolymer with the mixture and then spraying.

[0012] In some embodiments of the first aspect, the temperature of the spraying is room temperature, the ejection speed of the material is 0.5 g / s to 3 g / s, and the spraying pressure is 0.3 MPa to 0.8 MPa; the temperature of the curing reaction is room temperature, and the time of the curing reaction is 5 minutes to 10 minutes.

[0013] In some embodiments of the first aspect, based on the terminal isocyanate group of the polyurethane prepolymer and the terminal hydroxyl groups of the compound containing active hydrogen and the chain extender, the molar ratio of the polyurethane prepolymer to the total molar amount of the compound containing active hydrogen and the chain extender is (106 - 108):100, preferably 107:100; the mass ratio of the chain extender to the catalyst is (3 - 10):0.2; preferably, the mass ratio of the chain extender to the catalyst is (4 - 8.5):0.2.

[0014] In some embodiments of the first aspect, the polyurethane prepolymer is prepared from a diisocyanate composition, and the diisocyanate composition contains the following components in parts by weight: 50 parts to 80 parts of diisocyanate, 0.5 parts to 20 parts of hydroxyl-terminated siloxane, 15 parts to 30 parts of the compound containing active hydrogen; wherein the compound containing active hydrogen contains one compound having the structural formula HO-R-OH or a mixture of two or more compounds, and R is selected from an aliphatic polyester group, an aromatic polyester group, a polyether group, a polycarbonate group, a polycyclic ester group, a polylactic acid group, a polyolefin group.

[0015] In some embodiments of the first aspect, the diisocyanate includes at least one of aliphatic diisocyanate, cycloaliphatic diisocyanate, and aromatic diisocyanate; preferably, the diisocyanate includes at least one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, and xylylene diisocyanate; and / or, the hydroxyl-terminated siloxane comprises a compound represented by the following formula I, a mixture of two or more compounds, or a copolymer of two or more compounds: wherein m and n independently selected from integers of 2 to 100; the structural formula of R1 is (CH2) z , and z is selected from integers of 0 to 6; p is selected from integers of 2 to 10; preferably, the p is 6 or 8, and the average molecular weight of the hydroxyl-terminated siloxane is 1000 to 2500; and / or, in the structural formula of the active hydrogen-containing compound, R is selected from polytetrahydrofuranyl, polyoxypropylene group, poly(1,6-hexanediol terephthalate) group, poly(ethylene adipate) group, poly(butylene adipate) group; preferably, the average molecular weight of the active hydrogen-containing compound is 600 to 8000.

[0016] In some embodiments of the first aspect, the structural formula of the polyurethane prepolymer is as shown in the following formula II: wherein m and n independently selected from integers of 2 to 100; the structural formula of R1 is (CH2) z , and z is selected from integers of 0 to 6; p is selected from integers of 2 to 10; i is selected from integers of 1 to 50; the definition of X is the same as that of R, and Y is selected from aliphatic hydrocarbon group, cycloaliphatic hydrocarbon group, and aromatic hydrocarbon group.

[0017] In some embodiments of the first aspect, the method for preparing the polyurethane prepolymer includes: uniformly mixing the hydroxyl-terminated siloxane and the active hydrogen-containing compound, preheating, then adding the diisocyanate, gradually raising the temperature, continuing the constant-temperature reaction after the reaction system changes from turbid to transparent, and degassing after the content of isocyanate groups in the reaction system is qualified to obtain the polyurethane prepolymer.

[0018] In some embodiments of the first aspect, the preheating temperature is 50 °C, gradually raised to 70 °C to 110 °C, the constant-temperature reaction temperature is 70 °C to 110 °C, the constant-temperature reaction time is 0.5 hour to 5 hours, and the content of isocyanate groups in the reaction system less than 18.5% is qualified.

[0019] In some embodiments of the first aspect, the chain extender is at least one of an aliphatic chain extender and an aromatic chain extender; preferably, the chain extender is at least one of ethylene glycol, 1,4-butanediol, diethylene glycol, triethylene glycol, 1,2-propanediol, neopentyl glycol, methylpropanediol, 1,6-hexanediol, 1,3-propanediol, 3-methyl-1,5-pentanediol, 1,3-butanediol, 1,4-bis(hydroxymethyl)cyclohexane, 1,4-cyclohexanediol, hydroquinone bis(2-hydroxyethyl) ether, resorcinol bis(2-hydroxyethyl) ether, resorcinol bis(2-hydroxypropyl) ether, resorcinol bis(2-hydroxypropyl ethyl) ether, 4-(2-hydroxyethoxy)ethyl-1-(2-hydroxyethyl)benzene ether, 3-(2-hydroxyethoxy)ethyl-1-(2-hydroxyethyl)benzene ether, bisphenol A bis(2-hydroxyethyl) ether; and / or, the catalyst is at least one of bismuth neodecanoate, chelated bismuth, zinc isooctanoate, stannous octoate, 1,4-diazabicyclo[2.2.2]octane, triethylenediamine, acid-blocked triethylenediamine, 1,8-diazabicycloundec-7-ene.

[0020] The second aspect of the present invention provides a polyurethane film prepared by the method for preparing a polyurethane film according to any one of the above.

[0021] The third aspect of the present invention provides the use of the above polyurethane film in the manufacture of shoe insoles.

[0022] The fourth aspect of the present invention provides a shoe insole comprising the above polyurethane film.

[0023] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0024] Compared with the prior art in which polyurethane is used as a material for physical liquid phase deposition, the present invention uses a polyurethane prepolymer, a compound containing active hydrogen, a chain extender, and a catalyst as materials, and prepares a polyurethane film by chemical liquid phase deposition. On the one hand, the molecular weight of the materials of the present invention is small, and when sprayed for coating, the nozzles of the spraying equipment will not be blocked, which can not only ensure the stability of the coating process, but also improve the coating uniformity. As a result, the prepared polyurethane film has excellent thickness uniformity and can better restore the original morphology of the substrate surface, that is, it has good shape retention. On the other hand, the materials of the present invention can be directly coated without high-temperature heating and melting, thus fundamentally solving the problem of substrate damage caused by high temperature and reducing production energy consumption. Further, the present invention can cause the materials to undergo a curing reaction at room temperature and the curing time is short, which can not only solve the problem of substrate damage due to high temperature, but also greatly improve production efficiency. It can be seen that the present invention is particularly suitable for high-precision coating of polyurethane films on heat-sensitive substrates (such as plastics, fabrics, foaming materials, etc.).

[0025] Furthermore, the polyurethane prepolymer used in the present invention can be prepared by reacting specific parts by weight of diisocyanate, hydroxyl-terminated siloxane, and active hydrogen-containing compounds. This makes the prepared polyurethane film contain silicon and have siloxane groups in its molecular structure. Due to the low polarity of silicon, it can balance the high polarity of polyurethane molecules, thereby effectively improving the wet anti-slip effect of the polyurethane film. And the Si-O bond has high chemical bond strength and hydrophobicity, which can balance the hydrophilic polarity of the polyurethane film, improve the wet anti-slip property, and significantly improve the wear resistance of the polyurethane film. Therefore, the polyurethane film prepared by the present invention has excellent wear resistance and anti-slip property, and can be applied to clothing, shoes and hats to meet the use requirements of high anti-slip and high wear resistance for shoe soles, fabrics, clothing weaving coatings, etc., providing a material choice with more excellent wear resistance and anti-slip property for shoe soles, fabrics, and clothing weaving coatings.

[0026] At the same time, since the preparation method of the polyurethane film of the present invention can be directly cured and formed at room temperature on the substrate, it can completely match the shape of the substrate and has strong universality. There is no need for additional mold opening, which saves mold manufacturing and reduces the non-recurring engineering (NRE) cost. The process steps are simple, easy to automate, and convenient for industrial promotion and application, with great commercial prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the preparation method of the polyurethane film in the related art;

[0028] Figure 2 Schematic diagram of the preparation method of the polyurethane film in an embodiment of the present invention;

[0029] Figure 3 Appearance comparison diagram of the reaction system before and after synthesizing the polyurethane prepolymer in an embodiment of the present invention;

[0030] Figure 4 Optical microscope image of the polyurethane film prepared in Example 1 of the present invention;

[0031] Figure 5 Fourier transform infrared spectra of the polyurethane films prepared in Example 2 and Example 6 of the present invention and TPU in the scanning range of 400 - 4000 cm -1 When, Figure 5 In SiCura TM Represents the polyurethane film of Example 2, SiCura TM 20 represents the polyurethane film of Example 6;

[0032] Figure 6 Fourier transform infrared spectra of the polyurethane films prepared in Example 2 and Example 6 of the present invention and TPU in the scanning range of 500 - 2000 cm -1 When, Figure 6SiCura in TM represents the polyurethane film of Example 2, SiCura TM 20 represents the polyurethane film of Example 6. Detailed implementation manners

[0033] To better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with the drawings and specific embodiments. The substances used in the following embodiments are all common substances in the art, and can be prepared by well-known methods or directly purchased from the market.

[0034] Reference Figure 1 , currently the way to form a polyurethane film is PLD. The polyurethane material 1 is heated and melted at a high temperature to form molten particles 3. The molten particles 3 are sprayed on the surface of the substrate 4 through the nozzle 2 of the spraying device, and deposited to form a polyurethane film 5. However, due to the relatively large size of the molten particles 3 and the tendency to agglomerate, the nozzle 2 is easily blocked, and the molten particles 3 cannot be ejected, resulting in poor uniformity of the formed polyurethane film and even interruption of production. At the same time, the relatively large size of the molten particles 3 also causes the deposited polyurethane film to be relatively flat, which is not conducive to maintaining the surface morphology of the substrate 4, that is, the conformal property is poor. In addition, there are also problems such as high-temperature damage to the substrate 4.

[0035] Based on this, the embodiments of the present invention improve the preparation method of the polyurethane film. The polyurethane prepolymer, the compound containing active hydrogen, the chain extender and the catalyst are mixed and coated on the surface of the substrate by chemical liquid deposition method (CLD, Chemical Liquid Deposition). Among them, the polyurethane prepolymer, the compound containing active hydrogen and the chain extender undergo a curing reaction under the action of the catalyst and form the polyurethane film on the surface of the substrate. Since the molecular weights of the respective material components are relatively small and the particle size during spraying is small, the nozzle will not be blocked during spraying, and the formed film layer has good uniformity. At the same time, it can also better maintain the surface morphology of the substrate. At the same time, there is no need for high-temperature melting, fundamentally solving the problem of high-temperature damage to the substrate.

[0036] In some embodiments of the present invention, the method of mixing and coating the polyurethane prepolymer, the compound containing active hydrogen, the chain extender and the catalyst on the surface of the substrate by chemical liquid deposition method includes: mixing the polyurethane prepolymer, the compound containing active hydrogen, the chain extender and the catalyst and then spraying them on the surface of the substrate.

[0037] In some preferred embodiments of the present invention, the method of mixing the polyurethane prepolymer, the active hydrogen-containing compound, the chain extender, and the catalyst and then spraying includes: mixing some of the components evenly to obtain a mixture; mixing the remaining components with the mixture and then spraying. More preferably, the active hydrogen-containing compound, the chain extender, and the catalyst are mixed evenly to obtain a mixture; the polyurethane prepolymer is mixed with the mixture and then sprayed.

[0038] In some preferred embodiments of the present invention, the active hydrogen-containing compound, the chain extender, and the catalyst can be mixed at 60°C to 70°C.

[0039] Reference Figure 2 , in some specific embodiments of the present invention, the spraying material is divided into a first material A and a second material B for feeding. The first material A includes the polyurethane prepolymer, and the second material B includes the active hydrogen-containing compound, the chain extender, and the catalyst. The three components of the second material B are mixed evenly before feeding. The first material A and the second material B are mixed in a spraying device and sprayed onto the surface of the substrate 20 through the nozzle 10 of the spraying device. After curing reaction, a polyurethane film 30 with good thickness uniformity and shape retention is formed on the surface of the substrate 20.

[0040] In some preferred embodiments of the present invention, the temperature during spraying is room temperature, the ejection speed of the material is 0.5 g / s to 3 g / s, and the spraying pressure is 0.3 MPa to 0.8 MPa; the temperature of the curing reaction is room temperature, and the time of the curing reaction is 5 minutes to 10 minutes.

[0041] In some preferred embodiments of the present invention, based on the terminal isocyanate group of the polyurethane prepolymer and the terminal hydroxyl groups of the active hydrogen-containing compound and the chain extender, the molar ratio of the polyurethane prepolymer to the total molar number of the active hydrogen-containing compound and the chain extender is (106 - 108):100. More preferably, this molar ratio is 107:100.

[0042] In some preferred embodiments of the present invention, the mass ratio of the chain extender to the catalyst is (3 - 10):0.2. More preferably, the mass ratio of the chain extender to the catalyst is (4 - 8.5):0.2. Even more preferably, the mass ratio of the chain extender to the catalyst is (4.5 - 8):0.2.

[0043] Furthermore, although the current PU materials used for preparing sole materials or clothing fabrics have certain wear resistance and anti-slip effects, their wear resistance is limited. If higher wear strength is required, the PU materials are far from meeting the special functional requirements. At the same time, due to the high polarity and hydrophilicity of PU, the wet anti-slip effect of the outsole is not good, and the static friction coefficient is 0.30 - 0.45, which does not meet the usage requirements of professional sports shoes. Therefore, it is necessary to develop a polyurethane film with more excellent wear resistance and dry-wet anti-slip effects.

[0044] In this regard, the present invention improves the polyurethane prepolymer in the raw materials for preparing the polyurethane film. The polyurethane prepolymer is made from diisocyanate, hydroxyl-terminated siloxane, and the aforementioned compound containing active hydrogen. By introducing Si-O bonds into the main chain of the polyurethane prepolymer, the wear resistance of the polyurethane film is further improved. The side chain of the polyurethane prepolymer synthesized from the diisocyanate and hydroxyl-terminated siloxane described herein can be a long-chain group, and the long silane is located on the side chain, increasing the molecular swing space, and thus enhancing the reactivity with the glue during sole pasting and increasing the adhesion of the sole pasting.

[0045] In some preferred embodiments of the present invention, the polyurethane prepolymer is prepared from a diisocyanate composition, and the diisocyanate composition comprises the following components in parts by weight: 50 - 80 parts of diisocyanate, 0.5 - 20 parts of hydroxyl-terminated siloxane, and 15 - 30 parts of the compound containing active hydrogen.

[0046] In the diisocyanate composition, the structural formula of the compound containing active hydrogen is HO-R-OH, and R is selected from an aliphatic polyester group, an aromatic polyester group, a polyether group, a polycarbonate group, a polycyclic ester group, a polylactic acid group, and a polyolefin group. The compound containing active hydrogen comprises one compound represented by the above structural formula or a mixture of two or more compounds.

[0047] In some preferred embodiments of the present invention, R is selected from an aliphatic polyester group, an aromatic polyester group, and a polyether group. Specifically, R can be selected from at least one of a polytetrahydrofuran group, a polyoxypropylene group, a poly(1,6-hexanediol terephthalate) group, a polyethylene adipate group, and a polybutylene adipate group.

[0048] In some preferred embodiments of the present invention, the compound containing active hydrogen comprises at least one of poly(1,4-butanediol adipate) diol, polyether diol, polycarbonate diol, polylactic acid diol, polyester diol, and polybutadiene diol.

[0049] In some preferred embodiments of the present invention, the average molecular weight of the compound containing active hydrogen is 600 - 8000.

[0050] In some preferred embodiments of the present invention, the diisocyanate includes at least one of aliphatic diisocyanate, alicyclic diisocyanate, and aromatic diisocyanate. Further preferably, the diisocyanate includes at least one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, and xylylene diisocyanate.

[0051] In some preferred embodiments of the present invention, the hydroxyl-terminated siloxane comprises a compound represented by the following formula I or a mixture of two or more compounds:

[0052]

[0053] In the formula I, m and n each independently selected from integers of 2 to 200, for example, can be 2, 5, 10, 20, 30, 40, 50, 100, 150 or 200, etc. any value or integer in the range formed by two point values. p can be an integer between 2 and 10, for example, p is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. Further preferably, p is 6 or 8. The long side chain connected to the silicon atom can serve as a hydrophobic group, increasing the flexibility and hydrophobicity of the film surface, and further improving the wet anti-slip performance. The structural formula of R1 is (CH2) z , and z is selected from integers of 0 to 6.

[0054] The silicon provided by the hydroxyl-terminated siloxane can balance the high polarity of the polyurethane molecules, thereby improving the wet anti-slip performance of the polyurethane film. The siloxane therein can be introduced into the main chain of the polyurethane film, enabling the polyurethane film molecular chain to have the high strength of the Si-O bond and significantly improving the wear resistance of the polyurethane film. Preferably, the average molecular weight of the hydroxyl-terminated siloxane is 1000 to 2500. More preferably, the average molecular weight of the hydroxyl-terminated siloxane is 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500 or the range or sub-range between any two of them.

[0055] In some preferred embodiments of the present invention, the hydroxyl-terminated siloxane comprises a copolymer of at least two compounds of Formula I. For example, the hydroxyl-terminated siloxane is a copolymer of the compound with p = 6 and the compound with p = 8 in Formula I above, and the average molecular weight of the copolymer is 500 - 6000. When the hydroxyl-terminated siloxane comprises a copolymer of the compound with p = 6 and the compound with p = 8 in Formula I above, the polyurethane prepolymer prepared by reacting the hydroxyl-terminated siloxane with other raw materials has a more significant improvement effect on the abrasion resistance and anti-slip property of the polyurethane film.

[0056] In some preferred embodiments of the present invention, the structural formula of the polyurethane prepolymer is as shown in Formula II below:

[0057] Wherein, m and n independently selected from integers of 2 - 100. The structural formula of R1 is (CH2) z , and z is selected from integers of 0 - 6. p is selected from integers of 2 - 10. i is selected from integers of 1 - 50, and the numerical range of i depends on the molecular weight of the active hydrogen-containing compound, and can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50 or the range or sub-range between any two of these values. The definition of X is the same as R described above, and Y is selected from an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.

[0058] According to the structural formula II of the polyurethane prepolymer, when the diisocyanate, the hydroxyl-terminated siloxane, and the active hydrogen-containing compound undergo a polymerization reaction, the diisocyanate and the active hydrogen-containing compound are respectively grafted at both ends of the hydroxyl-terminated siloxane, and the resulting polyurethane prepolymer contains silicon and has a siloxane on the main chain. The low polarity of silicon is used to balance the high polarity of the PU molecules, thereby improving the wet anti-slip property of the polyurethane film. The siloxane on the main chain, connected by the high-strength covalent bond of Si-O, can significantly improve the abrasion resistance of the polyurethane film. The long silane is located on the side chain and has a functional group at the end, which can increase the adhesion. At the same time, the polyurethane prepolymer has a long silane side chain, which can reduce the crystallization of the polymer, thereby effectively solving the problem of stress concentration points generated when the material is bent due to crystallization, resulting in easy cracking, and making the polyurethane film have more excellent transparency and bend resistance.

[0059] In some preferred embodiments of the present invention, the method for preparing the polyurethane prepolymer comprises: uniformly mixing a hydroxyl-terminated siloxane and a compound containing active hydrogen, preheating, then adding a diisocyanate, gradually raising the temperature, and continuing the constant-temperature reaction after the reaction system changes from turbid to transparent. After the content of isocyanate groups (NCO% content) in the reaction system is qualified, defoaming is carried out to obtain the polyurethane prepolymer.

[0060] When the diisocyanate, hydroxyl-terminated siloxane and compound containing active hydrogen react, the reaction system will gradually change from turbid to transparent. Figure 3 The comparison between the mixed state before the reaction and the synthesized polyurethane prepolymer after the reaction is completed is shown. Figure 3 As can be seen from the right figure, before the reaction, the raw materials are mixed in a turbid state. At this time, the raw materials have not reacted yet, and the siloxane groups have not been attached to the main chain. Figure 3 As can be seen from the left figure, after the reaction raw materials react, the reaction system becomes semi-transparent, indicating that the siloxane groups (SiO) are attached to the main chain. Therefore, the color change of the reaction system can be used as a judgment of whether the siloxane groups are incorporated into the main chain. When the siloxane groups are incorporated into the main chain, the generated PU is in a transparent state. On the contrary, if the siloxane groups are not attached to the main chain, the reaction system presents a turbid state.

[0061] In the above preparation method, whether the NCO% content is qualified is used as the reaction end point, and the test method for the NCO% content is GB / T 601 HG / T2409-92 "Determination of the Content of Isocyanate Groups in Polyurethane Prepolymers". The NCO% content of the reaction system being less than the designed value is qualified. In some specific embodiments, when the NCO% content is less than 18.5%, it can be considered qualified. In other embodiments, when the NCO% content is less than 13%, 18%, 16.5%, 17%, 18%, it can be considered qualified.

[0062] In the above preparation method, after the hydroxyl-terminated siloxane and the compound containing active hydrogen are mixed, preheating is required first. In some preferred embodiments, the preheating temperature is 50°C.

[0063] After adding the diisocyanate to the mixture of the hydroxyl-terminated siloxane and the compound containing active hydrogen, further heating is required to enable them to react. In some preferred embodiments, the temperature is gradually raised to 70°C to 110°C. For example, it is gradually raised to any point value or the range value formed by two point values among 70°C, 80°C, 90°C, 100°C, 110°C.

[0064] After the reaction system turns from turbid to transparent, the reaction needs to continue under constant temperature to ensure sufficient reaction. In some preferred embodiments, the temperature of the constant-temperature reaction is 70°C to 110°C. More preferably, the temperature of the constant-temperature reaction is 80°C. The time of the constant-temperature reaction is not particularly limited, and generally 0.5 hours to 5 hours is appropriate. More preferably, the time of the constant-temperature reaction is 2 hours.

[0065] In some embodiments of the present invention, the preparation route of the polyurethane prepolymer is as follows:

[0066]

[0067] In some preferred embodiments of the present invention, the raw materials for preparing the polyurethane film include the following components in parts by weight: 15 to 40 parts of diisocyanate, 0.5 to 20 parts of hydroxyl-terminated siloxane, 50 to 80 parts of active hydrogen-containing compound, 3 to 10 parts of chain extender, and 0.2 part of catalyst.

[0068] In some preferred embodiments of the present invention, diisocyanate, hydroxyl-terminated siloxane, and active hydrogen-containing compound are first used for reaction to generate a polyurethane prepolymer, and then the polyurethane prepolymer, chain extender, and catalyst are mixed and coated on the surface of the substrate by chemical liquid deposition method. The polyurethane prepolymer and the chain extender undergo a curing reaction under the action of the catalyst, and the polyurethane film is formed on the surface of the substrate. The silicon contained in the polyurethane film has the characteristic of low polarity, which can balance the high polarity of polyurethane molecules, thereby effectively improving the wet anti-slip effect of the polyurethane film. In addition, the main chain of the polyurethane film molecule contains siloxane. Since the Si-O bond has high strength, the wear resistance of the polyurethane film can be significantly improved. Therefore, compared with the PU widely used in clothing and footwear at present, the polyurethane film of the present invention has significantly improved anti-slip performance and wear resistance, and can meet higher anti-slip and wear resistance requirements.

[0069] In some preferred embodiments of the present invention, the chain extender is at least one of an aliphatic chain extender and an aromatic chain extender. More preferably, the chain extender is at least one of ethylene glycol, 1,4-butanediol, diethylene glycol, triethylene glycol, 1,2-propanediol, neopentyl glycol, methylpropanediol, 1,6-hexanediol, 1,3-propanediol, 3-methyl-1,5-pentanediol, 1,3-butanediol, 1,4-bis(hydroxymethyl)cyclohexane, 1,4-cyclohexanediol, hydroquinone bis(2-hydroxyethyl) ether, resorcinol bis(2-hydroxyethyl) ether, resorcinol bis(2-hydroxypropyl) ether, resorcinol bis(2-hydroxypropyl ethyl) ether, 4-(2-hydroxyethoxy)ethyl-1-(2-hydroxyethyl)benzene ether, 3-(2-hydroxyethoxy)ethyl-1-(2-hydroxyethyl)benzene ether, bisphenol A bis(2-hydroxyethyl) ether. Even more preferably, the chain extender is at least one of ethylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexanediol, 1,3-propanediol, resorcinol bis(2-hydroxyethyl) ether.

[0070] In some preferred embodiments of the present invention, the catalyst is at least one of bismuth neodecanoate, chelated bismuth, zinc isooctanoate, stannous octoate, 1,4-diazabicyclo[2.2.2]octane (DABCO), triethylenediamine, acid-blocked triethylenediamine, 1,8-diazabicycloundec-7-ene (DBU). As an example, the catalyst is a mixture of bismuth neodecanoate and zinc isooctanoate. When the catalyst is a mixture of bismuth neodecanoate and zinc isooctanoate, the bismuth neodecanoate and zinc isooctanoate can be in any mass ratio, for example, the mass ratio of bismuth neodecanoate to zinc isooctanoate is 1:2, 1:1, etc.

[0071] The embodiment of the present invention also provides a polyurethane film, which is prepared by the preparation method of the polyurethane film described in any one of the above.

[0072] The polyurethane film described herein has excellent wear-resistant and anti-slip properties, can be used in the clothing, footwear and textile industries, and is widely used in shoe soles and fabrics, clothing fabric coatings, etc. Products such as clothing and footwear with this polyurethane film have more wear-resistant and anti-slip properties.

[0073] In some embodiments, the polyurethane film is applied to insole manufacturing, for example, the polyurethane film is coated on the shoe sole to make the insole have excellent wear resistance and anti-slip properties.

[0074] In the following examples, the hydroxyl-terminated siloxane used has the structure shown in Formula III:

[0075]

[0076] The average molecular weight of the hydroxyl-terminated siloxane is 1750, its appearance is a light yellow transparent liquid, the hydroxyl content is 2.0%, the kinematic viscosity at 25 °C is 30 cSt to 100 cSt, and the refractive index at 25 °C is 1.4260 ± 0.0050.

[0077] In the following specific examples, the ratio of the number of moles of the polyurethane prepolymer to the total number of moles of the active hydrogen-containing compound and the chain extender is calculated based on the terminal NCO groups of the polyurethane prepolymer and the terminal OH groups of the active hydrogen-containing compound and the chain extender. The spraying device is a two-component polyurethane casting machine connected to a high-pressure atomizing nozzle. The main materials used for the shoe sole are supercritical foamed TPU and EVA.

[0078] Example 1

[0079] This example provides a polyurethane film, and its preparation raw materials include the following components in parts by weight: 35 parts of diphenylmethane diisocyanate, 0.5 part of hydroxyl-terminated siloxane, 60 parts of poly(1,4-butylene adipate) glycol, 5.5 parts of ethylene glycol, and 0.2 part of catalyst. The average molecular weight of the poly(1,4-butylene adipate) glycol is 2000. The catalyst is a mixture of chelated bismuth and acid-blocked triethylenediamine with a mass ratio of 1:2.

[0080] The preparation method of the polyurethane film includes the following steps:

[0081] (1) Preparation of the polyurethane prepolymer

[0082] Mix the hydroxyl-terminated siloxane and part of the poly(1,4-butylene adipate) glycol evenly, preheat to 50 °C, then add diphenylmethane diisocyanate, gradually raise the temperature to 80 °C, and after the reaction system changes from turbid to transparent, continue to react at 80 °C for 2 hours. After the NCO% content in the reaction system is less than 16.5%, defoam to obtain the polyurethane prepolymer.

[0083] (2) Preparation of the polyurethane film

[0084] At 60 °C, mix the remaining poly(1,4-butylene adipate) glycol, ethylene glycol and catalyst evenly to obtain a mixture. At room temperature, feed the polyurethane prepolymer into one feed port of the spraying device, and feed the mixture into the other feed port of the spraying device. The polyurethane prepolymer and the mixture are mixed in the spraying device and then sprayed onto the surface of the shoe sole for curing.

[0085] The ratio of the molar number of the polyurethane prepolymer to the total molar number of the remaining poly(1,4-butylene adipate)-ethylene glycol ester diol and ethylene glycol is 107:100. The material ejection speed is 1 g / s, the spraying pressure is 0.4 MPa, the curing temperature is room temperature, and the curing time is 5 minutes, thus obtaining the polyurethane film of this example, and the film thickness is about 0.5 mm.

[0086] Example 2

[0087] This example provides a polyurethane film, and its preparation raw materials include the following components in parts by weight: 16 parts of toluene diisocyanate, 2 parts of hydroxyl-terminated siloxane, 76 parts of polyether diol, 6 parts of 1,4-butanediol, and 0.2 part of catalyst. The average molecular weight of the polyether diol is 3000. The catalyst is a mixture of bismuth neodecanoate and DBU with a mass ratio of 1:1.

[0088] The preparation method of the polyurethane film includes the following steps:

[0089] (1) Preparation of polyurethane prepolymer

[0090] Mix the hydroxyl-terminated siloxane and part of the polyether diol evenly, preheat to 50 °C, then add toluene diisocyanate, gradually raise the temperature to 110 °C, and after the reaction system changes from turbid to transparent, continue to react at a constant temperature of 110 °C for 0.5 hour. After the NCO% content in the reaction system is less than 13%, defoam to obtain the polyurethane prepolymer.

[0091] (2) Preparation of polyurethane film

[0092] At 60 °C, mix the remaining polyether diol, 1,4-butanediol and the catalyst evenly to obtain a mixture. The subsequent spraying operation can refer to Example 1.

[0093] The ratio of the molar number of the polyurethane prepolymer to the total molar number of the remaining polyether diol and 1,4-butanediol is 107:100. The material ejection speed is 0.5 g / s, the spraying pressure is 0.4 MPa, the curing temperature is room temperature, and the curing time is 5 minutes, thus obtaining the polyurethane film of this example, and the film thickness is about 0.25 mm.

[0094] Example 3

[0095] This example provides a polyurethane film, and its preparation raw materials include the following components in parts by weight: 32 parts of isophorone diisocyanate, 4 parts of hydroxyl-terminated siloxane, 58 parts of polycarbonate diol, 6 parts of diethylene glycol, and 0.2 part of chelated bismuth. The average molecular weight of the polycarbonate diol is 1000.

[0096] The preparation method of the polyurethane film includes the following steps:

[0097] (1) Preparation of polyurethane prepolymer

[0098] Mix the hydroxyl-terminated siloxane and partial polycarbonate diol evenly, preheat to 50 °C, then add isophorone diisocyanate, gradually raise the temperature to 70 °C. After the reaction system changes from turbid to transparent, continue to react at a constant temperature of 70 °C for 5 hours. After the NCO% content in the reaction system is less than 18%, defoam to obtain the polyurethane prepolymer.

[0099] (2) Preparation of polyurethane film

[0100] At 60 °C, mix the remaining polycarbonate diol, diethylene glycol and chelated bismuth evenly to obtain a mixture. The subsequent spraying operation can refer to Example 1.

[0101] The molar ratio of the polyurethane prepolymer to the total molar amount of the remaining polycarbonate diol and diethylene glycol is 107:100. The material spraying speed is 1 g / s, the spraying pressure is 0.45 MPa, the curing temperature is room temperature, and the curing time is 6 minutes to obtain the polyurethane film of this example. The film thickness is about 0.5 mm.

[0102] Example 4

[0103] This example provides a polyurethane film, and its preparation raw materials include the following components by weight: 18 parts of hexamethylene diisocyanate, 8 parts of hydroxyl-terminated siloxane, 67 parts of polylactic acid diol, 7 parts of 1,6-hexanediol, and 0.2 part of stannous octoate (T-9). The average molecular weight of the polylactic acid diol is 3000.

[0104] The preparation method of the polyurethane film includes the following steps:

[0105] (1) Preparation of polyurethane prepolymer

[0106] Mix the hydroxyl-terminated siloxane and partial polylactic acid diol evenly, preheat to 50 °C, then add hexamethylene diisocyanate, gradually raise the temperature to 90 °C. After the reaction system changes from turbid to transparent, continue to react at a constant temperature of 90 °C for 2 hours. After the NCO% content in the reaction system is less than 16.5%, defoam to obtain the polyurethane prepolymer.

[0107] (2) Preparation of polyurethane film

[0108] At 60 °C, mix the remaining polylactic acid diol, 1,6-hexanediol and stannous octoate (T-9) evenly to obtain a mixture. The molar ratio of the polyurethane prepolymer to the total molar amount of the remaining polylactic acid diol and 1,6-hexanediol is 107:100. The material spraying speed is 1 g / s, the spraying pressure is 0.42 MPa, the curing temperature is room temperature, and the curing time is 10 minutes to obtain the polyurethane film of this example. The film thickness is about 0.5 mm.

[0109] Example 5

[0110] This example provides a polyurethane film, and its preparation raw materials include the following components in parts by weight: 24.5 parts of dicyclohexylmethane diisocyanate, 12 parts of hydroxy-terminated siloxane, 58 parts of polycaprolactone diol, 5.5 parts of 1,3-propanediol, and 0.1 part of stannous octoate (T-9) / DBU after mixing in a ratio of 1 / 1. The average molecular weight of the polycaprolactone diol is 2000.

[0111] The preparation method of the polyurethane film includes the following steps:

[0112] (1) Preparation of polyurethane prepolymer

[0113] Mix the hydroxy-terminated siloxane and part of the polycaprolactone diol evenly, preheat to 50 °C, then add dicyclohexylmethane diisocyanate, gradually raise the temperature to 100 °C, and continue to react at a constant temperature of 100 °C for 1 hour after the reaction system changes from turbid to transparent. After the NCO% content in the reaction system is less than 17%, defoam to obtain the polyurethane prepolymer.

[0114] (2) Preparation of polyurethane film

[0115] At 60 °C, mix the remaining polycaprolactone diol, 1,3-propanediol and stannous octoate (T-9) / DBU evenly to obtain a mixture. The subsequent spraying operation can refer to Example 1.

[0116] The molar ratio of the polyurethane prepolymer to the total molar amount of the remaining polycaprolactone diol and 1,3-propanediol is 107:100. The material spraying speed is 1 g / s, the spraying pressure is 0.4 MPa, the curing temperature is room temperature, and the curing time is 4 minutes to obtain the polyurethane film of this example, and the film thickness is about 0.5 mm.

[0117] Example 6

[0118] This example provides a polyurethane film, and its preparation raw materials include the following components in parts by weight: 16 parts of xylylene diisocyanate, 20 parts of hydroxy-terminated siloxane, 56 parts of polybutadiene diol, 8 parts of resorcinol bis(2-hydroxyethyl) ether, 0.2 part of acid-blocked triethylenediamine, and 0.05 part of DBU. The average molecular weight of the polybutadiene diol is 2000.

[0119] The preparation method of the polyurethane film includes the following steps:

[0120] (1) Preparation of polyurethane prepolymer

[0121] Mix the hydroxyl-terminated siloxane and partial polybutylene glycol evenly, preheat to 50 °C, then add xylylene diisocyanate, gradually raise the temperature to 80 °C, after the reaction system turns from turbid to transparent, continue to react at a constant temperature of 80 °C for 3 hours, and degas after the NCO% content in the reaction system is less than 18% to obtain a polyurethane prepolymer.

[0122] (2) Preparation of polyurethane film

[0123] At 60 °C, mix the remaining polybutylene glycol, resorcinol bis(2-hydroxyethyl) ether, acid-blocked triethylenediamine and DBU evenly to obtain a mixture. The subsequent spraying operation can refer to Example 1.

[0124] The molar ratio of the polyurethane prepolymer to the total molar number of the remaining polybutylene glycol and resorcinol bis(2-hydroxyethyl) ether is 107:100. The material ejection speed is 1 g / s, the spraying pressure is 0.42 MPa, the curing temperature is room temperature, and the curing time is 9 minutes to obtain the polyurethane film of this example. The film thickness of the paint film is about 0.5 mm.

[0125] Comparative Example 1

[0126] Adopt the existing PLD process to directly spray the polyurethane (purchased from Lubrizol, model M95A) at high temperature and melt it on the surface of the shoe sole to form a polyurethane film. The spraying temperature is 225 °C and the ejection speed is 1 g / s.

[0127] Comparative Example 2

[0128] Adopt the existing PLD process to directly spray the polyurethane (purchased from Yantai Huada Chemical Co., Ltd., model 2180) on the surface of the shoe sole. The catalyst is DBU, the spraying temperature is 30 °C, and the feeding speed is 1 g / s. During the spraying process, the nozzle was blocked.

[0129] Comparative Example 3

[0130] Compared with Example 1, the difference in this comparative example is only that the hydroxyl-terminated siloxane is not added to the raw materials for preparing the polyurethane film.

[0131] Optical microscope test

[0132] Use a SangNond SN-0745 optical microscope to test the polyurethane film of Example 1. As Figure 4 shown, the gray area within the red dashed box represents the polyurethane film. Thus, it can be seen that the polyurethane film of Example 1 has excellent thickness uniformity.

[0133] Fourier transform infrared test (FT-IR)

[0134] The polyurethane films of Example 2 and Example 6 and TPU (produced by Yantai Wanhua, grade 1180) were subjected to Fourier transform infrared spectroscopy tests using a Thermo Scientific Nicolet iS5 Fourier transform infrared spectrometer from Thermo Fisher Scientific. The test method was as follows: The polyurethane films of Example 2 and Example 6 and TPU were respectively mixed with anhydrous KBr powder and ground evenly. The polyurethane films of Example 2 and Example 6 were mixed with anhydrous KBr powder at a ratio of 1:200 and 1:5 respectively to obtain SiCura TM (0.5%) samples and SiCura TM 20 (20%) samples. TPU was mixed with anhydrous KBr powder at a ratio of 1:200 to obtain TPU group samples. Subsequently, they were pressed into transparent thin film samples for infrared light to pass through. After instrument calibration and background scanning, the prepared samples were placed at the measurement position, and then the samples were scanned. The scanning range was 400 - 4000 cm -1 The test results at are shown in Figure 5 as shown, and the scanning range was 500 - 2000 cm -1 The test results at are shown in Figure 6 as shown.

[0135] In Figure 5 and Figure 6 , A is the Fourier transform infrared spectrum of TPU, B is the Fourier transform infrared spectrum of SiCura TM (0.5%) samples, and C is the Fourier transform infrared spectrum of SiCura TM 20 (20%) samples. The smaller the transmittance, the higher the content. TPU has an absorption peak at a wavenumber of 1017 cm -1 , and if there is an Si - O bond, the absorption will also be enhanced. For the Si - O bond, the peak position is at 1017 cm -1 . TPU does not contain Si - O bonds, so the original transmittance is 52.11. As the content of Si - O bonds increases, from SiCura TM (0.5%) to SiCura TM 20 (20%), its transmittance decreases from 49.18 to 40.95. At a wavenumber of 1063 - 1065 cm -1 , TPU does not contain Si - O bonds and has no obvious absorption peak. As the content of Si - O bonds increases, from SiCura TM (0.5%) to SiCura 20 (20%), its transmittance decreases from 34.92 to 33.29. For the Si - C bond, the peak position is at 1256 - 1269 cm -1 , TPU does not contain Si - C bonds and has no obvious absorption peak. As the content of Si - C bonds increases, SiCuraTM (0.5%) to SiCura20 (20%), and its transmittance ranges from 53.27 to 50.47. At a wavelength of 801 cm -1 the absorption peak is weak. After overlapping with TPU, for SiCura (0.5%) to SiCura20 (20%), the transmittance changes from being not obvious to 47.03.

[0136] Abrasion resistance effect test

[0137] The polyurethane films of Examples 1 to 6, Comparative Example 1, and Comparative Example 3 were respectively subjected to abrasion resistance tests. At the same time, styrene-butadiene rubber was used as a control group. The test method was the DIN53516 rubber abrasion test. The test results are shown in Table 2.

[0138] Table 2 Abrasion resistance test results of each group of materials

[0139] Group Wear value (mm3) Control group 90 Example 1 51 Example 2 40 Example 3 30 Example 4 23 Example 5 18 Example 6 15 Comparative example 1 54 Comparative example 3 60

[0140] As can be seen from Table 2, the wear amount of the polyurethane film prepared by the present invention is less than that of Comparative Example 1 and Comparative Example 3, indicating good abrasion resistance performance.

[0141] Anti-slip performance test

[0142] The polyurethane films of Examples 1 to 6, Comparative Example 1, and Comparative Example 3 were respectively subjected to anti-slip performance tests. At the same time, TPU was used as a control group. The test method was ASTM F609 "Standard Test Method for Using a Horizontal Pull Slipmeter (HPS)". The test result, the slip index, is ten times the static friction coefficient, and the test result is converted into the static friction coefficient. The test results of each group are shown in Table 3.

[0143] Table 3 Anti-slip performance test results of each group of materials

[0144] Group Static dry anti-slip friction coefficient Static wet anti-slip friction coefficient Control group 0.90 0.35 Example 1 0.85 0.40 Example 2 0.75 0.48 Example 3 0.65 0.58 Example 4 0.60 0.62 Example 5 0.58 0.65 Example 6 0.55 0.68 Comparative example 1 0.90 0.35 Comparative example 3 0.55 0.3

[0145] From the data in Table 3, it can be known that the dry-wet coefficient is a concept of the overall balance of the material. By adding siloxane, the hydrophobicity of the material is improved, the dry anti-slip coefficient can be reduced, and the wet anti-slip coefficient can be increased, making the dry-wet anti-slip more balanced, which is beneficial to the application of sports shoes in various occasions.

[0146] Adhesion test

[0147] An experimental group and a control group were set up. In the experimental group, the polyurethane film of Example 2 was adhered to EVA, and in the control group, TPU (Wanhua Chemical TPU A9084) was adhered to EVA. The adhesion of the materials in the experimental group and the control group to the sole and the glue was respectively tested. The test method was ASTM D903-98(2017) "Standard Test Method for Adhesive Peel or Stripping Strength". The test results of each group are shown in Table 4.

[0148] Table 4 Test results of the adhesion of each group of materials to the bottom and glue

[0149] Group <![CDATA[Adhesion between the bottom sticker and the glue (kgf / cm 2 )]]> Test group 3.0 Control group 2.5

[0150] It can be seen from the results in Table 4 that the long silane is located in the side chain, which can increase the adhesion between the bottom and the glue.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a polyurethane film, characterized in that, The preparation method includes: mixing a polyurethane prepolymer, a compound containing active hydrogen, a chain extender, and a catalyst by chemical liquid deposition and coating the mixture on the surface of a substrate, wherein the polyurethane prepolymer, the compound containing active hydrogen, and the chain extender undergo a curing reaction under the action of the catalyst to form the polyurethane film on the surface of the substrate.

2. The preparation method of the polyurethane film according to claim 1, characterized in that, The method of mixing a polyurethane prepolymer, a compound containing active hydrogen, a chain extender, and a catalyst by chemical liquid deposition and coating the mixture on the surface of a substrate includes: mixing the polyurethane prepolymer, the compound containing active hydrogen, the chain extender, and the catalyst and spraying the mixture on the surface of the substrate.

3. The method for preparing a polyurethane film according to claim 2, characterized in that, The method of spraying after mixing the polyurethane prepolymer, the compound containing active hydrogen, the chain extender, and the catalyst includes: Mixing the compound containing active hydrogen, the chain extender, and the catalyst evenly to obtain a mixture; Mixing the polyurethane prepolymer with the mixture and then spraying.

4. The method for preparing the polyurethane film according to claim 2, characterized in that, The temperature of the spraying is room temperature, the ejection speed of the material is 0.5 g / s to 3 g / s, and the spraying pressure is 0.3 MPa to 0.8 MPa; the temperature of the curing reaction is room temperature, and the time of the curing reaction is 5 minutes to 10 minutes.

5. The preparation method of the polyurethane film according to claim 1, characterized in that, Calculated based on the terminal isocyanate group of the polyurethane prepolymer and the terminal hydroxyl groups of the compound containing active hydrogen and the chain extender, the molar ratio of the polyurethane prepolymer to the total molar amount of the compound containing active hydrogen and the chain extender is (106 - 108):100, preferably 107:100; the mass ratio of the chain extender to the catalyst is (3 - 10):0.2; preferably, the mass ratio of the chain extender to the catalyst is (4 - 8.5):0.

2.

6. The preparation method of the polyurethane film according to any one of claims 1 to 5, characterized in that, The polyurethane prepolymer is prepared from a diisocyanate composition, and the diisocyanate composition includes the following components in parts by weight: 50 parts to 80 parts of diisocyanate, 0.5 part to 20 parts of hydroxyl-terminated siloxane, and 15 parts to 30 parts of the compound containing active hydrogen; Wherein the compound containing active hydrogen includes one compound or a mixture of two or more compounds with the structural formula HO-R-OH, and R is selected from an aliphatic polyester group, an aromatic polyester group, a polyether group, a polycarbonate group, a polycyclic ester group, a polylactic acid group, and a polyolefin group.

7. The method for preparing the polyurethane film according to claim 6, characterized in that, The diisocyanate includes at least one of an aliphatic diisocyanate, an alicyclic diisocyanate, and an aromatic diisocyanate; preferably, the diisocyanate includes at least one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, and xylylene diisocyanate; And / or, the hydroxyl-terminated siloxane includes one compound or a mixture of two or more compounds or a copolymer of two or more compounds represented by the following formula I: wherein, m and n are independently selected from integers of 2 to 100; the structural formula of R1 is (CH2) z , and z is selected from integers of 0 to 6; p is selected from integers of 2 to 10; preferably, the p is 6 or 8, and the average molecular weight of the hydroxyl-terminated siloxane is 1000 to 2500; And / or, in the structural formula of the active hydrogen-containing compound, R is selected from polytetrahydrofuran group, polypropylene oxide group, poly(1,6-hexanediol terephthalate) group, polyethylene adipate group, polybutylene adipate group; preferably, the average molecular weight of the active hydrogen-containing compound is 600 to 8000.

8. The preparation method of the polyurethane film according to claim 6, wherein, The structural formula of the polyurethane prepolymer is shown in the following formula II: wherein, m and n are independently selected from integers of 2 to 100; the structural formula of R1 is (CH2) z , and z is selected from integers of 0 to 6; p is selected from integers of 2 to 10; i is selected from integers of 1 to 50; X is defined the same as R described above, and Y is selected from an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.

9. The method for preparing a polyurethane film according to claim 6, characterized in that, The preparation method of the polyurethane prepolymer includes: uniformly mixing a hydroxyl-terminated siloxane and an active hydrogen-containing compound, preheating, then adding a diisocyanate, gradually raising the temperature, continuously carrying out a constant-temperature reaction after the reaction system turns from turbid to transparent, and degassing after the content of isocyanate groups in the reaction system is qualified to obtain the polyurethane prepolymer.

10. The method for preparing a polyurethane film according to claim 9, characterized in that, The preheating temperature is 50 °C, gradually raising the temperature to 70 °C - 110 °C, the constant-temperature reaction temperature is 70 °C - 110 °C, the constant-temperature reaction time is 0.5 hour - 5 hours, and the content of isocyanate groups in the reaction system being less than 18.5% is qualified.

11. The method for preparing a polyurethane film according to any one of claims 1 to 5, characterized in that, The chain extender is at least one of an aliphatic chain extender and an aromatic chain extender; preferably, the chain extender is at least one of ethylene glycol, 1,4-butanediol, diethylene glycol, triethylene glycol, 1,2-propanediol, neopentyl glycol, methylpropanediol, 1,6-hexanediol, 1,3-propanediol, 3-methyl-1,5-pentanediol, 1,3-butanediol, 1,4-bis(hydroxymethyl)cyclohexane, 1,4-cyclohexanediol, hydroquinone bis(2-hydroxyethyl) ether, resorcinol bis(2-hydroxyethyl) ether, resorcinol bis(2-hydroxypropyl) ether, resorcinol bis(2-hydroxypropyl ethyl) ether, 4-(2-hydroxyethoxyethyl)-1-(2-hydroxyethyl)benzene diether, 3-(2-hydroxyethoxyethyl)-1-(2-hydroxyethyl)benzene diether, bisphenol A bis(2-hydroxyethyl) ether; And / or, the catalyst is at least one of bismuth neodecanoate, chelated bismuth, zinc isooctanoate, stannous octoate, 1,4-diazabicyclo[2.2.2]octane, triethylenediamine, acid-blocked triethylenediamine, 1,8-diazabicycloundec-7-ene.

12. A polyurethane film, characterized in that, Prepared by the preparation method of the polyurethane film according to any one of claims 1 to 11.

13. Use of a polyurethane film according to claim 12 in the manufacture of shoe insoles.

14. An insole, characterized in that, Comprising a polyurethane film according to claim 12.

Images