Light-colored polyurethane resin for automotive interiors as well as preparation method and application of light-colored polyurethane resin

Abstract

The invention provides light-colored polyurethane resin for automotive interiors as well as a preparation method and application of the light-colored polyurethane resin. The polyurethane resin is prepared from the following raw materials: polyether glycol, polyester glycol, diisocyanate, reactive organic silicon and a chain extender. In the preparation raw materials of the polyurethane resin provided by the invention, the reactive organic silicon is matched with the polyether glycol, the polyester glycol, the diisocyanate and the chain extender to prepare the polyurethane, so that the polyurethane has good heat resistance, excellent stain resistance and wear resistance, and meets the performance requirements of light-color interiors.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and relates to a polyurethane resin, a preparation method thereof and an application, and particularly relates to a light-colored polyurethane resin for automotive interiors, a preparation method thereof and an application. Background Art

[0002] In 2009, driven by a series of intensive support policies, the new energy vehicle industry in China quickly entered the fast lane of development. Although the share of new energy vehicles in the Chinese automotive market is still relatively small, their growth potential has begun to gradually emerge in the Chinese commercial vehicle market.

[0003] The rapid increase in the use of PU (polyurethane) in new energy vehicle leather started in 2016. This transformation is closely related to the overall upgrade of the new energy vehicle market and a new stage of market orientation, marking a shift from policy guidance to market drive. During this period, local governments introduced a series of car purchase subsidies and infrastructure construction policies, and the subsidy policies for hybrid vehicles were also adjusted, thus promoting the rapid development of the new energy vehicle market. At the same time, due to its environmental friendliness, texture close to natural leather, high abrasion resistance and durability, and easy maintenance and cleaning characteristics, PU materials have gradually become the preferred choice for automotive interior materials. In addition, PU materials also play a key role in achieving the lightweight of automotive materials, further accelerating their application in automotive interiors.

[0004] Due to its environmental friendliness, texture close to natural leather, high abrasion resistance and durability, and easy maintenance and cleaning characteristics, PU materials have gradually become the preferred choice for automotive interior materials. In addition, PU materials also play a key role in achieving the lightweight of automotive materials, further accelerating their application in automotive interiors.

[0005] Light-colored interiors give people a delicate and noble visual experience and are liked by many customers. Therefore, the demand for light-colored automotive interiors, especially light-colored seats, is steadily increasing. However, there are currently two major technical problems in the development of light-colored interior polyurethane resins: (1) There are few resins that can simultaneously balance properties such as low-temperature flexure, heat aging resistance, light aging resistance, alcohol color fastness, and abrasion resistance; (2) Surface stain resistance is generally achieved through surface treatment and two-component crosslinking. However, this method increases costs and occasionally results in poor color fastness due to poor combination with other materials. There is no report in the market on how to directly achieve the stain resistance function through the design of the surface layer structure. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a polyurethane resin, its preparation method and application, especially to provide a light-colored polyurethane resin for automotive interior, its preparation method and application. The present invention provides a brand-new aliphatic polyurethane structure, in which reactive silicone is introduced, finally enabling the resin to have stain resistance and meet the performance requirements of light-colored interior, overcoming the deficiencies of the prior art.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] On the one hand, the present invention provides a polyurethane resin, and the raw materials for preparing the polyurethane resin include polyether diol, polyester diol, diisocyanate, reactive silicone, chain extender and catalyst.

[0009] In the raw materials for preparing the polyurethane resin of the present invention, reactive silicone is used in combination with polyether diol, polyester diol, diisocyanate and chain extender to prepare polyurethane, so that the polyurethane has good heat resistance, excellent stain resistance and wear resistance, meeting the performance requirements of light-colored interior.

[0010] In the raw materials for preparing the polyurethane resin of the present invention, polyether diol and polyester diol need to be used simultaneously, and the finally prepared product has both good low-temperature flexural performance, hydrolysis resistance and excellent temperature resistance, light resistance and heat aging resistance. If only polyether diol or polyester diol is used alone, all requirements cannot be met.

[0011] Preferably, the polyether diol is selected from polytetrahydrofuran diol.

[0012] Preferably, the number-average molecular weight of the polytetrahydrofuran diol is 1000 - 3500, such as 1000, 1300, 1500, 1800, 2000, 2300, 2500, 2800, 3000, 3300 or 3500, etc.

[0013] Preferably, the polyester diol is selected from any one or a combination of at least two of poly(1,4-butylene adipate) diol, poly(1,6-hexanediol adipate) diol, poly(neopentyl glycol adipate) diol, polycaprolactone diol, polycarbonate diol, poly(1,4-butylene adipate-co-glutarate) diol or poly(1,6-hexanediol adipate-co-glutarate) diol, preferably polycaprolactone diol and / or polycarbonate diol.

[0014] Preferably, the number-average molecular weight of the polyester diol is 1000 - 3500, such as 1000, 1300, 1500, 1800, 2000, 2300, 2500, 2800, 3000, 3300 or 3500, etc.

[0015] Preferably, the diisocyanate is any one or a combination of at least two of isophorone diisocyanate, hexamethylene diisocyanate or hydrogenated phenylmethane diisocyanate, preferably isophorone diisocyanate and / or hexamethylene diisocyanate.

[0016] Preferably, the reactive silicone is a mono-terminal amino-reactive silicone.

[0017] Preferably, the molecular formula of the mono-terminal amino-reactive silicone is as follows:

[0018] wherein n is an integer from 18 to 45 (such as 18, 20, 22, 25, 28, 30, 32, 34, 36, 38, 40, 42 or 45).

[0019] Preferably, the number-average molecular weight of the reactive silicone is 1500 - 3500, such as 1500, 1800, 2000, 2300, 2500, 2800, 3000, 3300 or 3500, etc.

[0020] Preferably, the chain extender is selected from any one or a combination of at least two of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, ethanolamine, 1,4-cyclohexanedimethanol or isophorone diamine, preferably 1,4-cyclohexanedimethanol and / or isophorone diamine.

[0021] Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the polyether diol is 1 - 8.1%, such as 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5% or 8%.

[0022] Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the polyester diol is 16 - 23.1%, such as 16%, 17%, 18%, 19%, 20%, 21%, 22% or 23%.

[0023] Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the diisocyanate is 2.9 - 5.1%, such as 2.9%, 3%, 3.3%, 3.5%, 3.8%, 4%, 4.3%, 4.5%, 4.8% or 5.1%.

[0024] Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the reactive silicone is 0.15% - 0.30%, such as 0.15%, 0.18%, 0.20%, 0.23%, 0.25%, 0.28% or 0.30%.

[0025] Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the chain extender is 0.9 - 2.1%, such as 0.9%, 1.0%, 1.3%, 1.5%, 1.8%, 2.0% or 2.1%.

[0026] Preferably, the raw materials for preparing the polyurethane resin further include a solvent.

[0027] Preferably, the solvent is selected from any one or a combination of at least two of N,N-dimethylformamide, toluene, methyl ethyl ketone, ethyl acetate, isopropyl alcohol or isobutyl alcohol.

[0028] Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the solvent is 65% - 75%, such as 65%, 68%, 70%, 72%, 74% or 75%.

[0029] Preferably, the catalyst is selected from any one or a combination of at least two of triethylamine, N,N-dimethylhexadecylamine, dibutyltin dilaurate, zinc isooctanoate, nickel isooctanoate, zinc neodecanoate, pyridine or diethanolamine, and preferably nickel isooctanoate (such as BiCAT 2536 from Leading Chemical in the United States).

[0030] Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the catalyst is 0.001 - 0.005%, such as 0.001%, 0.002%, 0.003%, 0.004% or 0.005%.

[0031] Preferably, the raw materials for preparing the polyurethane resin further include an antioxidant.

[0032] Preferably, the antioxidant is selected from any one or a combination of at least two of hindered phenol antioxidants or phosphite antioxidants, and preferably antioxidant 168.

[0033] Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the antioxidant is 0.02 - 0.05%, such as 0.02%, 0.03%, 0.04% or 0.05%.

[0034] On the other hand, the present invention provides a method for preparing the polyurethane resin as described above, and the preparation method includes the following steps:

[0035] (1) Mix the polyester diol, polyether diol with a part of the solvent and optionally an antioxidant, and then react with the diisocyanate;

[0036] (2) Add an optionally used catalyst to the reaction solution obtained in step (1) and react;

[0037] (3) Add a portion of the solvent to the reaction solution obtained in step (2), cool down the temperature, add a chain extender, then add a reactive silicone and the remaining solvent, and react to obtain the polyurethane resin.

[0038] Preferably, the portion of the solvent in step (1) is 40 - 50% of the total mass of the solvent, such as 40%, 43%, 45%, 48% or 50%.

[0039] Preferably, the mixing in step (1) is carried out at a temperature of 50 - 60 °C (such as 50 °C, 53 °C, 55 °C, 58 °C or 60 °C).

[0040] Preferably, the mixing in step (1) is carried out under normal pressure.

[0041] Preferably, the temperature of the reaction in step (1) is 70 - 80 °C (such as 70 °C, 73 °C, 75 °C, 78 °C or 80 °C), and the reaction time is 1.5 - 1 hour.

[0042] Preferably, the temperature of the reaction in step (2) is 85 - 100 °C (such as 85 °C, 88 °C, 90 °C, 93 °C, 95 °C, 98 °C or 100 °C), and the reaction time is 1.5 - 2.5 hours.

[0043] Preferably, the portion of the solvent in step (3) is 20 - 25% of the total mass of the solvent, such as 20%, 21%, 22%, 23%, 24% or 25%.

[0044] Preferably, the cooling in step (3) is to cool down to 35 - 45 °C, such as 35 °C, 38 °C, 40 °C, 43 °C or 45 °C.

[0045] Preferably, the temperature of the reaction in step (3) is 70 - 80 °C, such as 70 °C, 73 °C, 75 °C, 78 °C or 80 °C, and the time is 1 - 2 hours, such as 1 hour, 1.3 hours, 1.5 hours, 1.8 hours or 2 hours.

[0046] Preferably, the solid content of the polyurethane resin prepared in step (3) is 25% - 35%, such as 25%, 28%, 30%, 32%, 34% or 35%.

[0047] Preferably, the viscosity of the polyurethane resin prepared in step (3) at 25 °C is 60 - 120 Pa·s, such as 60 Pa·s, 70 Pa·s, 80 Pa·s, 90 Pa·s, 100 Pa·s, 110 Pa·s or 120 Pa·s.

[0048] On the other hand, the present invention provides the application of the polyurethane resin as described above in light-colored automotive interiors.

[0049] Preferably, the raw materials for preparing the light-colored automotive interior include the following components in percentage by weight:

[0050] The polyurethane resin as described above: 43.0 - 54.0% (such as 43%, 45%, 48%, 50% or 54%); solvent: 43.0 - 54.0% (such as 43%, 45%, 48%, 50% or 54%)

[0051] Light-colored color chips: 6.0 - 9.0% (such as 6%, 7%, 8% or 9%).

[0052] Preferably, the solvent is N,N-dimethylformamide.

[0053] Preferably, the light-colored color chips are white color chips.

[0054] Preferably, the raw materials for preparing the light-colored automotive interior further include 0.02% - 0.04% (such as 0.02%, 0.03% or 0.04%) of functional additives.

[0055] Preferably, the functional additives are organosilicon-based functional additives.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] In the raw materials for preparing the polyurethane resin of the present invention, reactive organosilicon is used in combination with polyether diol, polyester diol, diisocyanate and chain extender to prepare polyurethane, so that the polyurethane has good heat resistance, excellent stain resistance and wear resistance, meeting the performance requirements of light-colored interiors. Detailed Embodiments

[0058] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations to the present invention.

[0059] Some of the raw materials used in the following examples and comparative examples are as follows:

[0060] Polyester diol: Polycarbonate diol, with a number average molecular weight of 2000, purchased from Ube Industries, Ltd., Japan;

[0061] Polyether diol: Polytetrahydrofuran diol, with a number average molecular weight of 2000, purchased from Hyosung Corporation, Korea, and with a number average molecular weight of 3000, purchased from Hyosung Corporation, Korea.

[0062] Example 1

[0063] This example provides a polyurethane resin, and its raw materials for preparation include the components shown in Table 1 below:

[0064] Table 1

[0065] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 400 16.003％ Polytetrahydrofuran diol (number-average molecular weight 3000) 200 8.001％ Antioxidant BHT 0.8 0.032％ Isophorone diisocyanate 127.7 5.109％ Catalyst nickel octoate (leading chemical in the US, BiCAT 2536) 0.08 0.003％ Chain extender isophorone diamine 52.5 2.100％ N,N-Dimethylformamide 1300 52.009％ Isopropyl alcohol 411 16.443％ Reactive silicone, molecular weight 1800 (Wacker IM-11) 7.5 0.300％ Total mass 2499.58 100％

[0066] The preparation method of the polyurethane resin comprises the following steps:

[0067] Put polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into a reactor, and mix them evenly under normal pressure at 55°C (the N,N-dimethylformamide in this step is 35% of the total mass of N,N-dimethylformamide); then add isophorone diisocyanate, raise the temperature to 70°C, and keep the temperature for 1 hour;

[0068] Put in a catalyst, raise the temperature to 90°C, and keep the temperature for 2 hours;

[0069] Put in N,N-dimethylformamide (the N,N-dimethylformamide is 25% of the total mass of N,N-dimethylformamide), lower the temperature to 35 - 45°C; slowly add a chain extender to adjust the viscosity; then add a reactive silicone, isopropanol, and the remaining N,N-dimethylformamide, and keep the temperature at 70°C for 1 hour to obtain a polyurethane resin sample B1 with a solid content of 31.5% and a final viscosity of 80 Pa·s (25°C).

[0070] Example 2

[0071] This example provides a polyurethane resin, and its preparation raw materials include the components shown in Table 2 below:

[0072] Table 2

[0073] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 575 22.999％ Polytetrahydrofuran diol (number-average molecular weight 3000) 25 1.000％ Antioxidant BHT 0.8 0.032％ Isophorone diisocyanate 95 3.800％ Catalyst nickel octoate 0.08 0.003％ Chain extender isophorone diamine 22.5 0.900％ N,N-Dimethylformamide 1300 51.997％ Isopropyl alcohol 478 19.119％ Reactive silicone, molecular weight 1800 (Wacker IM-11) 3.75 0.150％ Total mass 2500.13 100％

[0074] The preparation method of the polyurethane resin comprises the following steps:

[0075] Put polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into a reactor, and mix them evenly under normal pressure at 60°C (the N,N-dimethylformamide in this step is 35% of the total mass of N,N-dimethylformamide); then add isophorone diisocyanate, raise the temperature to 80°C, and keep the temperature for 1 hour;

[0076] Put in a catalyst, raise the temperature to 85°C, and keep the temperature for 2.5 hours;

[0077] Put in N,N-dimethylformamide (the N,N-dimethylformamide is 25% of the total mass of N,N-dimethylformamide), lower the temperature to 35°C; slowly add a chain extender to adjust the viscosity; add a reactive silicone, isopropanol, and the remaining N,N-dimethylformamide, and keep the temperature at 70°C for 1 hour to obtain a polyurethane resin sample B2 with a solid content of 28.9% and a final viscosity of 60 Pa·s (25°C);

[0078] Example 3

[0079] This example provides a polyurethane resin, and its preparation raw materials include the components shown in Table 3 below:

[0080] Table 3

[0081] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 500 19.997％ Polytetrahydrofuran diol (number-average molecular weight 3000) 100 3.999％ Antioxidant BHT 0.8 0.032％ Isophorone diisocyanate 111.8 4.471％ Catalyst nickel octoate 0.08 0.003％ Isophorone diamine 37.5 1.500％ N,N-Dimethylformamide 1300 51.991％ Isopropyl alcohol 444 17.757％ Reactive silicone, molecular weight 1800 (Wacker IM-11) 6.25 0.250％ Total mass 2500.43 100％

[0082] The preparation method of the polyurethane resin includes the following steps:

[0083] Put the polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into the reactor, and mix them evenly under normal pressure at 50 °C (the N,N-dimethylformamide is 45% of the total mass of N,N-dimethylformamide); then add isophorone diisocyanate, raise the temperature to 70 °C, and keep the temperature for reaction for 1.5 hours;

[0084] Put in the catalyst, raise the temperature to 100 °C, and keep the temperature for 1.5 hours; put in N,N-dimethylformamide (the N,N-dimethylformamide is 25% of the total mass of N,N-dimethylformamide), lower the temperature to 35 °C; slowly add the chain extender to adjust the viscosity; add the reactive silicone, isopropanol, and the remaining N,N-dimethylformamide, and keep the temperature at 70 °C for 1 hour to obtain a polyurethane resin sample B3 with a solid content of 30.3% and a final viscosity of 70 Pa·s (25 °C).

[0085] Example 4

[0086] This example provides a polyurethane resin, and its preparation raw materials include the components shown in Table 4 below:

[0087] Table 4

[0088] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 500 19.999％ Polytetrahydrofuran diol (number-average molecular weight 3000) 100 4.000％ Antioxidant BHT 0.8 0.032％ Isophorone diisocyanate 111.8 4.472％ Catalyst nickel octoate 0.08 0.003％ Isophorone diamine 37.5 1.500％ N,N-Dimethylformamide 1300 51.996％ Isopropyl alcohol 445 17.798％ Reactive silicone, molecular weight 1800 (Wacker IM-11) 5 0.200％ Total mass 2500.18 100％

[0089] The preparation method of the polyurethane resin includes the following steps:

[0090] Put the polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into the reactor, and mix them evenly under normal pressure at 55 °C (the N,N-dimethylformamide is 40% of the total mass of N,N-dimethylformamide);

[0091] Then add isophorone diisocyanate, raise the temperature to 75 °C, and keep the temperature for reaction for 1 hour;

[0092] Add the catalyst and heat up to 95°C, then keep the temperature for 2 hours; add N,N-dimethylformamide (the N,N-dimethylformamide accounts for 25% of the total mass of N,N-dimethylformamide), and lower the temperature to 35°C; slowly add the chain extender and adjust the viscosity; add the reactive silicone, isopropyl alcohol and the remaining N,N-dimethylformamide to terminate the reaction, and keep the temperature at 70°C for 2 hours to obtain a polyurethane resin sample B4 with a solid content of 30.2% and a final viscosity of 100 Pa·s (25°C).

[0093] Example 5

[0094] This example provides a polyurethane resin, and its preparation raw materials include the components shown in Table 5 below:

[0095] Table 5

[0096] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 550 21.998％ Polytetrahydrofuran diol (number-average molecular weight 3000) 50 2.000％ Antioxidant BHT 0.8 0.032％ Isophorone diisocyanate 94.1 3.764％ Catalyst dibutyltin dilaurate 0.08 0.003％ Chain extender 1,4-cyclohexanedimethanol 22.5 0.900％ N,N-Dimethylformamide 1300 51.995％ Isopropyl alcohol 479 19.158％ Reactive silicone, molecular weight 1800 (Wacker IM-11) 3.75 0.150％ Total mass 2500.23 100％

[0097] The preparation method of the polyurethane resin includes the following steps:

[0098] Put the polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into the reactor and mix evenly under normal pressure at 50°C (the N,N-dimethylformamide accounts for 40% of the total mass of N,N-dimethylformamide); then add isophorone diisocyanate, heat up to 80°C, and keep the temperature for reaction for 1.5 hours;

[0099] Add the catalyst, heat up to 100°C, and keep the temperature for 1.5 hours; add N,N-dimethylformamide (the N,N-dimethylformamide accounts for 25% of the total mass of N,N-dimethylformamide), and lower the temperature to 35°C; slowly add the chain extender and adjust the viscosity; add the reactive silicone, isopropyl alcohol and the remaining N,N-dimethylformamide, and keep the temperature at 70°C for 2 hours to obtain a sample B5 with a solid content of 28.9% and a final viscosity of 120 Pa·s (25°C).

[0100] Example 6

[0101] This example provides a polyurethane resin, and its preparation raw materials include the components shown in Table 6 below:

[0102] Table 6

[0103] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 575 23.003％ Polytetrahydrofuran diol (number-average molecular weight 3000) 25 1.000％ Antioxidant BHT 0.8 0.032％ Isophorone diisocyanate 95 3.801％ Catalyst zinc octoate 0.08 0.003％ Chain extender ethylene glycol 22.5 0.900％ N,N-Dimethylformamide 1300 52.008％ Isopropyl alcohol 475 19.003％ Reactive silicone, molecular weight 1800 (Wacker IM-11) 6.25 0.250％ Total mass 2499.63 100％

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

[0105] Put polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into a reactor, and mix them evenly under normal pressure at 60 °C (the N,N-dimethylformamide accounts for 35-45% of the total mass of N,N-dimethylformamide); then add isophorone diisocyanate, raise the temperature to 80 °C, and keep the temperature for 1 hour;

[0106] Put in the catalyst, raise the temperature to 85 °C, and keep the temperature for 2.5 hours; put in N,N-dimethylformamide (the N,N-dimethylformamide accounts for 25% of the total mass of N,N-dimethylformamide), lower the temperature to 35 °C; slowly add the chain extender to adjust the viscosity; add reactive silicone, isopropanol and the remaining N,N-dimethylformamide to terminate the reaction, and keep the temperature at 70 °C for 1 hour to obtain a sample B6 with a solid content of 29% and a final viscosity of 110 Pa·s (25 °C).

[0107] Example 7

[0108] This example provides a polyurethane resin, and its preparation raw materials include the components shown in Table 7 below:

[0109] Table 7

[0110] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 575 23.002％ Polytetrahydrofuran diol (number-average molecular weight 3000) 25 1.000％ Antioxidant BHT 0.8 0.032％ Isophorone diisocyanate 21.8 0.872％ Hexamethylene diisocyanate 50.4 2.016％ Catalyst nickel octoate 0.08 0.003％ Chain extender isophorone diamine 22.5 0.900％ N,N-Dimethylformamide 1300 52.004％ Isopropyl alcohol 498 19.921％ Reactive silicone, molecular weight 1800 (Wacker IM-11) 6.25 0.250％ Total mass 2499.83 100％

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

[0112] Put polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into a reactor, and mix them evenly under normal pressure at 55 °C (the N,N-dimethylformamide accounts for 40% of the total mass of N,N-dimethylformamide); then add two kinds of isocyanates, raise the temperature to 70 °C, and keep the temperature for 1.5 hours;

[0113] Put in the catalyst, raise the temperature to 90 °C, and keep the temperature for 2.5 hours; put in N,N-dimethylformamide (the N,N-dimethylformamide accounts for 25% of the total mass of N,N-dimethylformamide), lower the temperature to 40 °C; slowly add the chain extender to adjust the viscosity; add reactive silicone, isopropanol and the remaining N,N-dimethylformamide, and keep the temperature at 70 °C for 1 hour to obtain a sample B7 with a solid content of 28.1% and a final viscosity of 100 Pa·s (25 °C).

[0114] Example 8

[0115] This example provides a polyurethane resin, and its preparation raw materials include the components shown in Table 8 below:

[0116] Table 8

[0117] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 575 23.001％ Polytetrahydrofuran diol (number-average molecular weight 3000) 25 1.000％ Antioxidant BHT 0.8 0.032％ Isophorone diisocyanate 29.1 1.164％ Hexamethylene diisocyanate 43.2 1.728％ Catalyst 0.08 0.003％ Isophorone diamine 22.5 0.900％ N,N-Dimethylformamide 1300 52.001％ Isopropyl alcohol 498 19.921％ Reactive silicone, molecular weight 1800 (Wacker IM-11) 6.25 0.250％ Total mass 2499.93 100％

[0118] The preparation method of the polyurethane resin comprises the following steps:

[0119] Put polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into a reactor, and mix evenly under normal pressure at 60°C (the N,N-dimethylformamide accounts for 45% of the total mass of N,N-dimethylformamide);

[0120] Then add two kinds of isocyanates, raise the temperature to 80°C, and keep the temperature for reaction for 1.5 hours; put in the catalyst, raise the temperature to 85°C, and keep the temperature for 2 hours; put in N,N-dimethylformamide (the N,N-dimethylformamide accounts for 25% of the total mass of N,N-dimethylformamide), lower the temperature to 45°C; slowly add the chain extender to adjust the viscosity; add reactive silicone, isopropanol and the remaining N,N-dimethylformamide, and keep the temperature at 70°C for 1 hour to obtain a sample B8 with a solid content of 28.1% and a final viscosity of 100 Pa·s (25°C).

[0121] Example 9

[0122] This example provides a polyurethane resin, and its preparation raw materials include the components shown in Table 9 below:

[0123] Table 9

[0124] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 575 23.000％ Polytetrahydrofuran diol (number-average molecular weight 3000) 25 1.000％ Antioxidant BHT 0.8 0.032％ Isophorone diisocyanate 36.4 1.456％ Hexamethylene diisocyanate 36 1.440％ Catalyst 0.08 0.003％ Isophorone diamine 22.5 0.900％ N,N-Dimethylformamide 1300 51.999％ Isopropanol 498 19.920％ Reactive silicone, molecular weight 1800 (Wacker IM-11) 6.25 0.250％ Total mass 2500.03 100％

[0125] The preparation method of the polyurethane resin comprises the following steps:

[0126] Put polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into a reactor, and mix evenly under normal pressure at 60°C (the N,N-dimethylformamide accounts for 35% of the total mass of N,N-dimethylformamide);

[0127] Then add two kinds of isocyanates, raise the temperature to 80°C, and keep the temperature for reaction for 1 hour; put in the catalyst, raise the temperature to 100°C, and keep the temperature for 2 hours; put in N,N-dimethylformamide (the N,N-dimethylformamide accounts for 25% of the total mass of N,N-dimethylformamide), lower the temperature to 35°C; slowly add the chain extender to adjust the viscosity; add reactive silicone, isopropanol and the remaining N,N-dimethylformamide, and keep the temperature at 70°C for 1 hour to obtain a sample B9 with a solid content of 28% and a final viscosity of 90 Pa·s (25°C).

[0128] Example 10

[0129] This example provides a polyurethane resin, and its preparation raw materials include the components shown in Table 10 below:

[0130] Table 10

[0131] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 575 22.999％ Polytetrahydrofuran diol (number-average molecular weight 3000) 25 1.000％ Antioxidant BHT 0.8 0.032％ Isophorone diisocyanate 43.7 1.748％ Hexamethylene diisocyanate 28.8 1.152％ Catalyst 0.08 0.003％ Isophorone diamine 22.5 0.900％ N,N-Dimethylformamide 1300 51.997％ Isopropanol 498 19.919％ Reactive silicone, molecular weight 1800 (Wacker IM-11) 6.25 0.25％ Total mass 2500.13 100％

[0132] The preparation method of the polyurethane resin comprises the following steps:

[0133] Put polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into a reactor, and mix evenly under normal pressure at 50 °C (the N,N-dimethylformamide accounts for 40% of the total mass of N,N-dimethylformamide); then add two kinds of isocyanates, raise the temperature to 70 °C, and keep the temperature for reaction for 1.5 hours; put in a catalyst, raise the temperature to 100 °C, and keep the temperature for 2.5 hours; put in N,N-dimethylformamide (the N,N-dimethylformamide accounts for 25% of the total mass of N,N-dimethylformamide), lower the temperature to 35 °C; slowly add a chain extender to adjust the viscosity; add a reactive silicone, isopropanol, and the remaining N,N-dimethylformamide, keep the temperature at 70 °C for 2 hours, to obtain a sample B10 with a solid content of 29.1% and a final viscosity of 80 Pa·s (25 °C).

[0134] Example 11

[0135] This example provides a polyurethane resin, and its preparation raw materials include the components shown in Table 11 below:

[0136] Table 11

[0137] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 575 22.998％ Polytetrahydrofuran diol (number-average molecular weight 3000) 25 1.000％ Antioxidant BHT 0.8 0.032％ Isophorone diisocyanate 51 2.040％ Hexamethylene diisocyanate 21.6 0.864％ Catalyst 0.08 0.003％ Isophorone diamine 22.5 0.900％ N,N-Dimethylformamide 1300 51.995％ Isopropanol 498 19.918％ Reactive silicone, molecular weight 1800 (Wacker IM-11) 6.25 0.250％ Total mass 2500.23 100％

[0138] The preparation method of the polyurethane resin comprises the following steps:

[0139] Put polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into a reactor, and mix evenly under normal pressure at 55 °C; (the N,N-dimethylformamide accounts for 35% of the total mass of N,N-dimethylformamide)

[0140] Then add two kinds of isocyanates, raise the temperature to 80 °C, and keep the temperature for reaction for 1 hour; put in a catalyst, raise the temperature to 85 °C, and keep the temperature for 2 hours; put in N,N-dimethylformamide (the N,N-dimethylformamide accounts for 25% of the total mass of N,N-dimethylformamide), lower the temperature to 35 °C; slowly add a chain extender to adjust the viscosity; add a reactive silicone, isopropanol, and the remaining N,N-dimethylformamide, terminate the reaction, keep the temperature at 70 °C for 1 hour, to obtain a sample B11 with a solid content of 30% and a final viscosity of 120 Pa·s (25 °C).

[0141] Comparative Example 1

[0142] This comparative example provides a polyurethane resin, and its preparation raw materials include the components shown in Table 12 below:

[0143] Table 12

[0144] Raw material name Weight (g) Percentage (%) Polycarbonate diol (number-average molecular weight 2000) 360 14.297％ Polytetrahydrofuran diol (number-average molecular weight 2000) 200 7.943％ Antioxidant BHT 0.4 0.015％ Isophorone diisocyanate 137 5.441％ Catalyst nickel octoate (American Lead Chemical BiCAT 2536) 0.08 0.003％ Isophorone diamine 57.4 2.280％ N,N-Dimethylformamide 1100 43.684％ Isopropanol 661.2 26.258％ Di-n-butylamine 2 0.079％ Total mass 2518.08 100％

[0145] The preparation method of the polyurethane resin comprises the following steps:

[0146] Put polycarbonate diol, polytetrahydrofuran diol, N,N-dimethylformamide, and antioxidant into a reactor, and mix evenly under normal pressure at 55°C (the N,N-dimethylformamide in this step is 35% of the total mass of N,N-dimethylformamide); then add isophorone diisocyanate, raise the temperature to 70°C, and keep the temperature for reaction for 1 hour; put in a catalyst, raise the temperature to 90°C, and keep the temperature for 2 hours; put in N,N-dimethylformamide (the N,N-dimethylformamide is 25% of the total mass of N,N-dimethylformamide), lower the temperature to 35°C; slowly add a chain extender to adjust the viscosity; then add di-n-butylamine, isopropanol, and the remaining N,N-dimethylformamide, and keep the temperature at 70°C for 1 hour to obtain a polyurethane resin sample A1 with a solid content of 30.1% and a final viscosity of 100 Pa·s (25°C).

[0147] Comparative Example 2

[0148] The difference from Example 1 is only that polytetrahydrofuran diol is replaced by polypropylene glycol (purchased from Bluestar Dongda Co., Ltd., 3003LM) to prepare polyurethane resin sample A2.

[0149] Comparative Example 3

[0150] The difference from Example 1 is only that the reactive silicone is replaced by a double-ended amino-reactive silicone (purchased from Slok, grade Silok 4422, molecular weight 2000) to prepare polyurethane resin sample A3. Due to the too high reactivity of the double-ended amino-reactive silicone, the crosslinking degree of the product is relatively high, and the product is in a gel state, making it difficult to carry out subsequent film-making and leather-making applications, so the subsequent performance tests cannot be carried out.

[0151] Comparative Example 4

[0152] The difference from Example 1 is only that the reactive silicone is replaced by a side-chain amino-reactive silicone (purchased from Slok, grade Silok 3306, molecular weight 6000) to prepare polyurethane resin sample A4.

[0153] Comparative Example 5

[0154] The difference from Example 1 is only that the reactive silicone is replaced by hydroxy silicone oil (purchased from Dow Corning, grade PMX0156, molecular weight 1560) to prepare polyurethane resin sample A5.

[0155] Comparative Example 6

[0156] It is only different from Example 1 in that the reactive silicone is replaced with a mono-terminal amino reactive silicone with a higher molecular weight (purchased from Silok, product number Silok 3300, molecular weight 18000), and polyurethane resin sample A6 is prepared.

[0157] Application Examples 1-11 and Comparative Application Examples 1-6

[0158] The resin applications include film making and leather making. The raw materials used in leather making include the above synthesized resin, solvent, color chips, and functional additives, where:

[0159] There are 6 comparative samples A1, A1 + surface treatment, A2, A4, A5, A6, and 11 example samples B1-B11 of the synthesized resin;

[0160] The solvent is N,N-dimethylformamide;

[0161] The color chips are white, pigment HP-H142S (extra white) from Huapu New Materials Company;

[0162] The functional additive is a silicone type, BYK-L9565 from BYK Chemie;

[0163] The film making and leather making applications of the above polyurethane resin include the following steps:

[0164] Leather sample preparation method: Put 100 parts of polyurethane resin, 100 parts of N,N-dimethylformamide, 0.05 part of leveling agent BYK-L9565, and 18 parts of white chips HP-H142S into a sample cup in sequence, stir and mix evenly with a dispersant, and coat the mixed solution on the release paper with a coating thickness of 0.15 mm, bake at 130 °C for 5 min, repeat this operation, then directly coat a layer of mixed working slurry of solvent-free JF-NS-9030A and JF-NS-9030B with a thickness of 0.35 mm on the film (Zhejiang Huafeng Synthetic Resin Co., Ltd.), put it into a 120 °C oven for 1-2 minutes, then directly stick a 0.8 mm thick automotive leather base cloth (Jiangsu Beltford Co., Ltd.), roll it back and forth 5 times with a roller press bar, put it into a 135 °C oven and bake for 5 minutes, and then release it from the release paper to obtain automotive interior leather.

[0165] Normal temperature folding resistance test method: For the leather samples prepared above, use a folding resistance sampling die (45 mm * 70 mm) to cut several sample pieces on the leather samples in sequence, with half of the sample pieces in the warp and weft directions. The name of the leather sample, warp and weft directions, temperature conditions, and folding resistance times should be marked on the back of the sample pieces. According to the set conditions, install the cut sample pieces on a normal temperature folding resistance testing machine (Gao Tie, Taiwan Province, China, equipment model GT-7071-B) for testing, and record the folding resistance results according to the test situation.

[0166] Low-temperature folding endurance test method: For the leather samples prepared above, use a folding endurance sampling die (45mm * 70mm) to cut a certain number of samples from the leather samples in sequence. The number of samples in the warp and weft directions is each half. The name of the leather sample, warp and weft directions, temperature condition (-20°C), and number of folding endurance should be marked on the back of the samples. Set the temperature to -20°C, and install the cut samples on a low-temperature folding endurance testing machine (Hongda, Taiwan Province, China, equipment model HT-8043) for testing respectively. Record the folding endurance results according to the test situation.

[0167] Xenon lamp aging resistance test method: Cut the leather samples prepared above into a size of 50 * 70mm, and the name of the leather sample should be marked on the back of the samples in sequence. According to the set conditions, place the cut samples in a xenon lamp aging equipment (Atlas xenon lamp weather resistance test chamber, USA) for testing respectively. The test conditions are set according to 5 cycles and 7 cycles. Record the ΔE results according to the test situation.

[0168] Hydrolysis resistance test method: Cut the leather samples prepared above into a size of 30mm * 120mm, and the name of the leather sample should be marked on the back of the samples in sequence. Put them into a constant temperature and humidity chamber, set the temperature to 70°C and the humidity to 95%RH. According to the set conditions, place the cut samples in a constant temperature and humidity chamber (Zhongli Instrument, HZ-3626) respectively. Take them out after placing for 10 weeks, dry them and then test the peel strength.

[0169] Abrasion resistance test method: Cut the leather samples prepared above into circular samples with a diameter of 110mm, and leave an 8mm hole in the middle. Use a Taber-5135 abrasion resistance machine for testing. The test conditions are H-22 grinding wheel and 1kg weight, and record the results.

[0170] Heat resistance test method: Cut the leather samples prepared above into a size of 50mm * 100mm, and the name of the leather sample should be marked on the back of the samples in sequence. Put them into an electrothermal constant temperature and pressure blower (Shanghai Qixin, DHG-9123AD), set the temperature to 120°C, take them out after placing for 500 hours, and observe whether the surface is shiny.

[0171] The test results are shown in Table 13 - Table 15.

[0172] Table 13 Physical Property Detection Table

[0173]

[0174] Table 14 Physical Property Detection Table

[0175]

[0176] Table 15 Physical Property Detection Table

[0177]

[0178] Remarks: (1) The more ☆, the more serious the shiny degree of the leather sample surface. The more serious the shiny degree, the worse the heat resistance. (2) The full name of surface treatment is "surface treatment", that is, Stahl waterborne polyurethane 549 is coated on the leather sample surface, and a crosslinked cured film is formed after 3 minutes at 140 °C, so as to improve the wear resistance, heat resistance, alcohol resistance and other properties of the leather sample surface.

[0179] As can be seen from the above table, the polyurethane resin B8 sample prepared by the present invention has a low polyether content. After introducing HDI, a stable structure is formed, and it has excellent folding resistance at normal and low temperatures, xenon lamp aging resistance, alcohol resistance, hydrolysis resistance, excellent heat resistance, and the wear resistance can be comparable to the sample after surface treatment.

[0180] The applicant declares that the present invention uses the above embodiments to illustrate the light-colored automotive interior polyurethane resin and its preparation method and application of the present invention, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A polyurethane resin, characterized in that The raw materials for preparing the polyurethane resin include polyether diol, polyester diol, diisocyanate, reactive organic silicon, chain extender and catalyst.

2. The polyurethane resin according to claim 1, characterized in that The polyether diol is selected from polytetrahydrofuran diol; Preferably, the number average molecular weight of the polytetrahydrofuran diol is 1000-3500; Preferably, the polyester diol is selected from any one or a combination of at least two of poly(1,4-butylene adipate diol), poly(1,6-hexane adipate diol), poly(neopentyl adipate diol), poly(caprolactone diol), polycarbonate diol, poly(1,4-butylene adipate glutarate diol) or poly(1,6-hexane adipate glutarate diol), preferably poly(caprolactone diol) and / or polycarbonate diol; Preferably, the number average molecular weight of the polyester diol is 1000-3500.

3. The polyurethane resin according to claim 1 or 2, characterized in that The diisocyanate is any one of isophorone diisocyanate, hexamethylene diisocyanate or hydrogenated phenylmethane diisocyanate or a combination of at least two thereof, preferably isophorone diisocyanate and / or hexamethylene diisocyanate.

4. The polyurethane resin according to any one of claims 1 to 3, characterized in that The reactive silicone is a single-terminal amine reactive silicone; Preferably, the molecular formula of the single-terminal amine-reactive organosilicon is as follows: Where n is an integer between 18 and 45; Preferably, the number average molecular weight of the reactive silicone is 1500-3500.

5. The polyurethane resin according to any one of claims 1 to 4, characterized in that The chain extender is selected from any one of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, ethanolamine, 1,4-cyclohexanedimethanol or isophoronediamine, or a combination of at least two thereof, preferably 1,4-cyclohexanedimethanol and / or isophoronediamine.

6. The polyurethane resin according to any one of claims 1 to 5, characterized in that Based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the polyether diol is 1-8.1%; Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the polyester diol is 16-23.1%; Preferably, based on 100% of the total weight of the raw materials for preparing the polyurethane resin, the content of the diisocyanate is 2.9-5.1%; Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the reactive silicone is 0.15%-0.30%; Preferably, based on 100% of the total weight of the raw materials for preparing the polyurethane resin, the content of the chain extender is 0.9-2.1%.

7. The polyurethane resin according to any one of claims 1 to 6, characterized in that The raw materials for preparing the polyurethane resin also include a solvent; Preferably, the solvent is selected from any one or a combination of at least two of N,N-dimethylformamide, toluene, butanone, ethyl acetate, isopropanol or isobutanol; Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the solvent is 65%-75%; Preferably, the catalyst is selected from any one or a combination of at least two of triethylamine, N,N-dimethylhexadecylamine, dibutyltin dilaurate, zinc isooctanoate, nickel isooctanoate, zinc neodecanoate, pyridine or diethanolamine, preferably nickel isooctanoate; Preferably, based on the total weight of the raw materials for preparing the polyurethane resin being 100%, the content of the catalyst is 0.001-0.005%; Preferably, the raw materials for preparing the polyurethane resin further include an antioxidant; Preferably, the antioxidant is selected from any one or a combination of at least two of hindered phenol antioxidants or phosphite antioxidants, preferably antioxidant 168; Preferably, based on 100% of the total weight of the raw materials for preparing the polyurethane resin, the content of the antioxidant is 0.02-0.05%.

8. The method for preparing a polyurethane resin according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: (1) mixing polyester diol, polyether diol, part of solvent and optional antioxidant, and then reacting with diisocyanate; (2) adding a catalyst to the reaction solution obtained in step (1) and reacting; (3) adding part of the solvent to the reaction solution obtained in step (2), cooling the temperature, adding a chain extender, and then adding reactive silicone and the remaining solvent to react to obtain the polyurethane resin.

9. The preparation method according to claim 8, characterized in that: The partial solvent in step (1) is 40-50% of the total mass of the solvent; Preferably, the mixing in step (1) is carried out at a temperature of 50-60°C; Preferably, the mixing in step (1) is carried out under normal pressure; Preferably, the reaction temperature in step (1) is 70-80° C., and the reaction time is 0.5-1.5 hours; Preferably, the reaction temperature in step (2) is 85-100° C., and the reaction time is 1.5-3 hours; Preferably, the catalyst in step (2) is an organic bismuth catalyst; Preferably, the partial solvent in step (3) is 20-25% of the total mass of the solvent; Preferably, the cooling in step (3) is cooling to 35-45°C; Preferably, the reaction temperature in step (3) is 70-80°C and the reaction time is 0.5-3 hours; Preferably, the solid content of the polyurethane resin prepared in step (3) is 25%-35%; Preferably, the viscosity of the polyurethane resin prepared in step (3) at 25° C. is 60-120 Pa.s.

10. Use of the polyurethane resin according to any one of claims 1 to 7 in light-colored automobile interiors.

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