Solvent-free polyurethane resin for automobile leather as well as preparation method and application of solvent-free polyurethane resin

Abstract

The invention discloses solvent-free polyurethane resin for automobile leather and a preparation method and application thereof, and relates to resin for coating parts and seats in the fields of automobiles and the like, the resin comprises a component A and a component B. The component A is prepared from long-chain alkyl modified organic silicon polyether glycol, polyether glycol, polyether triol, a chain extender, a catalyst and a flame retardant, and the component B is prepared from a component C and a component B. The component C is prepared from long-chain alkyl modified organic silicon polyether glycol, polyether glycol, polyether triol, a chain extender, a catalyst and a flame retardant. The component B is prepared from organic silicon modified polyether glycol, polyether triol and diisocyanate; the component A and the component B are mixed according to the weight ratio of (100: 60)-(100: 80) to obtain the resin. The resin overcomes the defects in the aspects of coating performance, thermal tensile property, curing performance and the like of automobile leather, and has good peel strength, cold resistance, hydrolysis resistance and high temperature resistance.

Description

Technical Field

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

[0002] Due to the vigorous development of the new energy vehicle industry, the consumption of automotive leather will also increase accordingly. However, at present, except for a very small amount of genuine leather and water-based polyurethane leather, automotive leather is basically PVC and solvent-based polyurethane automotive leather.

[0003] PVC automotive leather is made by coating fiber-based cloth with PVC, which requires the addition of a large amount of plasticizers and other additives. The resulting automotive leather has serious defects such as strong odor, plasticizers that are not environmentally friendly and easy migration to the surface. This defect is more serious in the narrow space of a car, so PVC automotive leather is gradually being eliminated.

[0004] Polyurethane automotive leather includes solvent-based automotive leather and environmentally friendly water-based automotive leather. Solvent-based automotive leather has excellent performance, but its fabric and foaming layer contain a large amount of DMF, a solvent that is harmful to the human body, and the production is seriously polluted. In addition, DMF cannot be completely removed from the leather, which is harmful to human health when used.

[0005] At present, some automotive leathers on the market use solvent-free polyurethane, but they are generally used on ordinary automotive leather instrument panels and other covering parts. However, for some seat leathers with complex patterns, it is difficult to meet the requirements in terms of covering properties. Since covering parts such as automotive leather seats and instrument panels require excellent covering properties and good ironing properties, the resin itself is required to have good thermoplasticity. Therefore, automotive leathers on the market are basically solvent-based polyurethanes, which contain a large amount of DMF, a solvent that is harmful to the human body, and have an odor.

[0006] Therefore, with the booming development of the new energy vehicle industry today, it is necessary to develop a solvent-free polyurethane resin for automotive leather with good coating properties. Summary of the invention

[0007] The invention provides a solvent-free polyurethane resin for automobile leather and a preparation method and application thereof, so as to solve the problems of poor coating property, ironing property and thermoplasticity existing in the prior art solvent-free polyurethane used for automobile leather.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A solvent-free polyurethane resin for automobile leather, prepared from component A and component B in a mass ratio of 100:60-100:80;

[0010] Wherein, the A component comprises the following components in parts by weight:

[0011]

[0012] The long-chain alkyl-modified silicone polyether diol in the A component is a diol with a molecular weight of 3000 obtained by reacting a long-chain side-chain hydrogenated silicone oil with an acryl polyether;

[0013] The B component includes the following components in parts by weight:

[0014]

[0015] The organosilicon-modified polyether diol in the B component is a diol with a molecular weight of 1000 synthesized by reacting low molecular weight linear hydroxyl-terminated polysiloxane (PDMS-OH) and allyl alcohol polyether.

[0016] Furthermore, the polyether diol in the component A is polytetrahydrofuran diol with a molecular weight of 1000-3000.

[0017] Furthermore, the polyether triol of component A is polyoxypropylene triol with a molecular weight of 3000-6000; and the polyether triol of component B is polyoxypropylene triol with a molecular weight of 500-1000.

[0018] Furthermore, the chain extender in the component A is any one of ethylene glycol, 1,3-propylene glycol, 1,4-butanediol and 1,5-pentanediol.

[0019] Furthermore, the catalyst in the A component is any one of BiCAT 8106, BiCAT 8108, BiCAT 8124, BiCAT3228, Borchi Kat 22, Borchi Kat 24, BiCAT 4130, BiCAT 4232, MB20 and the phenolate, formates and hydrochlorides of the above-mentioned organometallic catalysts; the catalyst used in the B component is the metal catalyst MB-20.

[0020] Furthermore, the flame retardant in the component A is an environmentally friendly halogen-free flame retardant of aluminum hypophosphite type.

[0021] Furthermore, the diisocyanate in the component B is any one of 4,4'-diphenylmethane diisocyanate, a mixture of 2,4-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

[0022] A method for preparing the above-mentioned solvent-free polyurethane resin for automobile leather comprises the following steps:

[0023] (1) Preparation of long-chain side chain hydrogen-containing silicone oil:

[0024] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, different hydrogen-containing siloxanes and a certain amount of H2SO4 as a catalyst were added into the flask, reacted at 50°C for 8 hours and then cooled to room temperature, and after neutralization by adding Na2CO3, the solid components were removed by vacuum filtration, and then high-temperature distillation was performed at 120°C to obtain long-chain hydrogen-containing siloxanes;

[0025] (2) Preparation of long-chain alkyl-modified silicone polyether diols:

[0026] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, and long-chain hydrogen-containing organosiloxane and allyl alcohol polyether with a ratio of n(Si-H):n(double bond) of 1:1.2 were added into the flask. An isopropanol solution containing 50 mg / g of chloroplatinic acid was used as a catalyst. The reaction temperature was controlled at 80°C. After reacting for 5-6 hours, a long-chain alkyl-modified organosilicon polyether diol was prepared by vacuum distillation, and the molecular weight was measured to be 3000.

[0027] (3) Preparation of silicone-modified polyether diols:

[0028] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, and low molecular weight linear hydroxyl-terminated polysiloxane and allyl alcohol polyether with n(Si-H):n(double bond) being 1:1.15 were added into the flask, and an isopropanol solution containing 50 mg / g of chloroplatinic acid was selected as the catalyst. The reaction temperature was controlled at 80°C, and after reacting for 5-6 hours, the organosilicon-modified polyether diol was prepared by vacuum distillation, and the measured molecular weight was 1000;

[0029] (4) Preparation of component A:

[0030] Put long-chain alkyl modified silicone polyether diol, polyether diol, polyether triol and chain extender into a reaction kettle, then add catalyst and flame retardant in sequence, heat to 50-90°C and stir for 2-4h to obtain component A;

[0031] (5) Preparation of component B:

[0032] Add diisocyanate and phosphoric acid into the reaction kettle and stir evenly, then add organosilicon-modified polyether diol, polyether triol and catalyst and heat to 80-120°C, stir for 2-5h, then measure NCO%, and discharge the material after the measurement is qualified, thus obtaining component B;

[0033] (6) Preparation of solvent-free polyurethane resin for automotive leather:

[0034] The obtained component A and component B are mixed at a mass ratio of 100:60-100:80, then coated on release paper, and dried at 130° C. to obtain a solvent-free polyurethane resin for automotive leather.

[0035] A kind of application of the above solvent-free polyurethane resin for automobile leather in the preparation of solvent-free polyurethane synthetic leather for automobile. When applied, firstly, a water-based surface layer AW-50Y is scraped on the release paper, and after drying, the solvent-free polyurethane resin for automobile leather is applied to the dried fabric, and then pre-reacted in a 130°C oven for 60-100s, and after the pre-reaction is completed, the base fabric is attached, and after being pressed by a roller, it is placed in an oven at 130°C for aging for 10 minutes, and then rolled up to obtain the solvent-free polyurethane synthetic leather for automobile; it not only has a good hand feel, but also has a cold resistance of up to -20°C, no cracking after 30,000 flexings, and a peel strength of more than 120N / 3cm.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] (1) The present invention is a polyether system solvent-free polyurethane resin, and the long-chain alkyl-modified silicone polyether diol and silicone-modified polyether diol are introduced to provide good physical properties, excellent low-temperature flexibility and hydrolysis resistance;

[0038] (2) The present invention uses a special long-chain alkyl modified silicone polyether diol with a molecular weight of 3000 and a silicone modified polyether diol with a molecular weight of 1000 to synthesize a solvent-free polyurethane resin. The prepared automotive leather has excellent low temperature resistance, hydrolysis resistance and high temperature resistance, and has good wrapping ability and ironing shaping effect;

[0039] (3) The solvent-free resin for automotive leather of the present invention has the advantages of not requiring the use of DMF organic solvent during the manufacturing and application process, no organic solvent residue in the finished leather, greatly reduced exhaust power of the newly customized oven, greatly reduced energy consumption, no industrial wastewater discharge, and no solid waste. DETAILED DESCRIPTION

[0040] The present invention is further explained below through specific examples. However, it should be noted that the specific material ratios, process conditions and results described in the examples of the present invention are only used to illustrate the present invention and cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

[0041] Example 1

[0042] Example 1 discloses a solvent-free polyurethane resin for automotive leather, which is prepared from component A and component B in a mass ratio of 100 / 80;

[0043] Wherein, the A component comprises the following components in parts by weight:

[0044] 40 parts of long-chain alkyl-modified silicone polyether diol

[0045] 40 parts of polyether diol

[0046]

[0047] The long-chain alkyl-modified silicone polyether diol in the A component is a diol with a molecular weight of 3000 obtained by reacting a long-chain side-chain hydrogenated silicone oil with an acryl polyether;

[0048] The B component includes the following components in parts by weight:

[0049]

[0050] The organosilicon-modified polyether diol in the B component is a diol with a molecular weight of 1000 synthesized by reacting low molecular weight linear hydroxyl-terminated polysiloxane (PDMS-OH) and allyl alcohol polyether.

[0051] The polyether diol in component A is polytetrahydrofuran diol with a molecular weight of 1000-3000.

[0052] The polyether triol of component A is polyoxypropylene triol with a molecular weight of 3000-6000; the polyether triol of component B is polyoxypropylene triol with a molecular weight of 500-1000.

[0053] The chain extender in component A is any one of ethylene glycol (EG), 1,3-propylene glycol (1,3-PG), 1,4-butanediol (1,4-BG) and 1,5-pentanediol (1,5-PG).

[0054] The catalyst in component A is any one of BiCAT 8106, BiCAT 8108, BiCAT 8124, BiCAT3228, BorchiKat 22, Borchi Kat 24, BiCAT 4130, BiCAT 4232, MB20 and the phenolate, formates and hydrochlorides of the above-mentioned organometallic catalysts; the catalyst used in component B is the metal catalyst MB-20.

[0055] The flame retardant in component A is an environmentally friendly halogen-free flame retardant of the aluminum hypophosphite type.

[0056] The diisocyanate in component B is any one of 4,4'-diphenylmethane diisocyanate (MDI), a mixture of 2,4-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate (IPDI), and 4,4'-dicyclohexylmethane diisocyanate (HMDI).

[0057] Example 1 also discloses a method for preparing a solvent-free polyurethane resin for automotive leather, comprising the following steps:

[0058] (1) Preparation of long-chain side chain hydrogen-containing silicone oil:

[0059] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, and 200 g of tetramethylcyclotetrasiloxane, 100 g of hexamethyldisiloxane and 250 g of octamethylcyclotetrasiloxane were added to the flask. 2 g of H2SO4 was added as a catalyst, and the mixture was reacted at 50°C for 8 hours and then cooled to room temperature. Na2CO3 was added for neutralization and then vacuum filtered to remove the solid components, and then high-temperature distillation was performed at 120°C to obtain long-chain hydrogen-containing siloxane.

[0060] (2) Preparation of long-chain alkyl-modified silicone polyether diols:

[0061] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, 400 g of a long-chain hydrogen-containing organosiloxane and 200 g of allyl alcohol polyether were added into the flask at a ratio of n(Si-H):n(double bond) of 1:1.2, 10 g of an isopropanol solution of 50 mg / g chloroplatinic acid was added as a catalyst, the reaction temperature was controlled at 80°C, and after reacting for 5-6 hours, a long-chain alkyl-modified organosilicon polyether diol was prepared by vacuum distillation, and the molecular weight was measured to be 3000.

[0062] (3) Preparation of silicone-modified polyether diols:

[0063] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, and 200 g of low molecular weight linear hydroxyl-terminated polysiloxane (PDMS-OH) and 330 g of allyl alcohol polyether were added into the flask at a ratio of n(Si-H):n(double bond) of 1:1.15, and 10 g of an isopropanol solution of 50 mg / g chloroplatinic acid was added as a catalyst. The reaction temperature was controlled at 80°C, and after reacting for 5-6 hours, the organosilicon-modified polyether diol was prepared by reduced pressure distillation, and the molecular weight was measured to be 1000.

[0064] (4) Preparation of component A:

[0065] 40g of long-chain alkyl modified silicone polyether diol, 40g of polyether diol PTMG-1000, 12g of polyether triol DEP-330N and 8g of chain extender BG were put into a reactor, stirred and heated to 65°C, then 50g of 3852 flame retardant was added and stirred evenly, the flame retardant was completely dissolved in the polyol, and then 0.02g of catalyst BiCAT 3228 was added when the temperature dropped to 35°C, stirred evenly, and component A was obtained, which was sealed and packaged for standby use.

[0066] (5) Preparation of component B:

[0067] 60g of diisocyanate MDI and 0.15g of phosphoric acid were added into the reactor and stirred evenly. Then 30g of silicone-modified polyether diol, 10g of DMN-700 and 0.05g of catalyst MB-20 were added and the temperature was raised to 80°C. The reaction was carried out for 4h. The NCO% was then determined to be 16%. After the determination was qualified, the material was discharged to obtain component B, which was then sealed and packaged for later use.

[0068] (6) Preparation of solvent-free polyurethane resin for automotive leather: The obtained component A and component B are mixed evenly in a mass ratio of 100:80 using a low-pressure casting machine, and then coated on a release paper and dried at 130° C. to obtain a solvent-free polyurethane resin for automotive leather.

[0069] Example 1 also discloses the application of the above solvent-free polyurethane resin for automobile leather in the preparation of solvent-free polyurethane synthetic leather for automobile. When applied, firstly, a water-based surface layer AW-50Y is scraped on the release paper, and after drying, the solvent-free polyurethane resin for automobile leather is applied to the dried fabric, and then pre-reacted in an oven at 130°C for 60s, and the base fabric is directly attached thereto, and after being pressed by a roller, it is placed in an oven at 130°C for aging for 10 minutes, and then rolled up to obtain solvent-free automobile leather.

[0070] Example 2

[0071] Example 2 discloses a solvent-free polyurethane resin for automotive leather, which is prepared from component A and component B in a mass ratio of 100 / 70;

[0072] Wherein, the A component comprises the following components in parts by weight:

[0073]

[0074] The long-chain alkyl-modified silicone polyether diol in the A component is a diol with a molecular weight of 3000 obtained by reacting a long-chain side-chain hydrogenated silicone oil with an acryl polyether;

[0075] The B component includes the following components in parts by weight:

[0076]

[0077] The organosilicon-modified polyether diol in the B component is a diol with a molecular weight of 1000 synthesized by reacting low molecular weight linear hydroxyl-terminated polysiloxane (PDMS-OH) and allyl alcohol polyether.

[0078] The polyether diol in component A is polytetrahydrofuran diol with a molecular weight of 1000-3000.

[0079] The polyether triol of component A is polyoxypropylene triol with a molecular weight of 3000-6000; the polyether triol of component B is polyoxypropylene triol with a molecular weight of 500-1000.

[0080] The chain extender in component A is any one of ethylene glycol (EG), 1,3-propylene glycol (1,3-PG), 1,4-butanediol (1,4-BG) and 1,5-pentanediol (1,5-PG).

[0081] The catalyst in component A is any one of BiCAT 8106, BiCAT 8108, BiCAT 8124, BiCAT3228, BorchiKat 22, Borchi Kat 24, BiCAT 4130, BiCAT 4232, MB20 and the phenolate, formates and hydrochlorides of the above-mentioned organometallic catalysts; the catalyst used in component B is the metal catalyst MB-20.

[0082] The flame retardant in component A is an environmentally friendly halogen-free flame retardant of the aluminum hypophosphite type.

[0083] The diisocyanate in component B is any one of 4,4'-diphenylmethane diisocyanate (MDI), a mixture of 2,4-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate (IPDI), and 4,4'-dicyclohexylmethane diisocyanate (HMDI).

[0084] Example 2 also discloses a method for preparing a solvent-free polyurethane resin for automotive leather, comprising the following steps:

[0085] (1) Preparation of long-chain side chain hydrogen-containing silicone oil:

[0086] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, and 200 g of tetramethylcyclotetrasiloxane, 100 g of hexamethyldisiloxane and 250 g of octamethylcyclotetrasiloxane were added to the flask. 2 g of H2SO4 was added as a catalyst, and the mixture was reacted at 50°C for 8 hours and then cooled to room temperature. Na2CO3 was added for neutralization and then vacuum filtered to remove the solid components, and then high-temperature distillation was performed at 120°C to obtain long-chain hydrogen-containing siloxane.

[0087] (2) Preparation of long-chain alkyl-modified silicone polyether diols:

[0088] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, 400 g of a long-chain hydrogen-containing organosiloxane and 200 g of allyl alcohol polyether were added into the flask at a ratio of n(Si-H):n(double bond) of 1:1.2, 10 g of an isopropanol solution of 50 mg / g chloroplatinic acid was added as a catalyst, the reaction temperature was controlled at 80°C, and after reacting for 5-6 hours, a long-chain alkyl-modified organosilicon polyether diol was prepared by vacuum distillation, and the molecular weight was measured to be 3000.

[0089] (3) Preparation of silicone-modified polyether diol:

[0090] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, and 200 g of low molecular weight linear hydroxyl-terminated polysiloxane (PDMS-OH) and 330 g of allyl alcohol polyether were added into the flask at a ratio of n(Si-H):n(double bond) of 1:1.15, and 10 g of an isopropanol solution of 50 mg / g chloroplatinic acid was added as a catalyst. The reaction temperature was controlled at 80°C, and after reacting for 5-6 hours, the organosilicon-modified polyether diol was prepared by reduced pressure distillation, and the molecular weight was measured to be 1000.

[0091] (4) Preparation of component A:

[0092] 50g of long-chain alkyl modified silicone polyether diol, 30g of polyether diol PTMG-1000, 11g of polyether triol DEP-330N and 9g of chain extender BG were put into a reactor, stirred and heated to 65°C, then 75g of 3852 flame retardant was added and stirred evenly, the flame retardant was completely dissolved in the polyol, and then 0.1g of catalyst BiCAT 8108 was added when the temperature dropped to 35°C, stirred evenly, and component A was obtained, which was sealed and packaged for standby use.

[0093] (5) Preparation of component B:

[0094] 54g of diisocyanate MDI and 0.15g of phosphoric acid were added into the reactor and stirred evenly, then 33.5g of silicone-modified polyether diol, 12.5g of polyether triol DMN-700 and 0.07g of catalyst were added and the temperature was raised to 80°C. The reaction was carried out for 4h, and then the NCO% was determined to be 13%. After the determination was qualified, the material was discharged to obtain component B, which was sealed and packaged for later use.

[0095] (6) Preparation of solvent-free polyurethane resin for automotive leather:

[0096] The obtained component A and component B are mixed evenly at a mass ratio of 100:70 using a low-pressure casting machine, and then coated on release paper, and dried at 130° C. to obtain a solvent-free polyurethane resin for automotive leather seats.

[0097] Example 2 also discloses the application of the above solvent-free polyurethane resin for automobile leather in the preparation of solvent-free polyurethane synthetic leather for automobile. When using, firstly apply the water-based surface layer AW-50Y on the release paper, and then apply the solvent-free polyurethane resin for automobile leather seats on the dried fabric after drying, and then pre-react in an oven at 130°C for 80s, directly attach the base fabric, and then put it in an oven at 130°C for aging for 10 minutes after rolling, and then roll it up to obtain solvent-free synthetic leather for automobile leather seats.

[0098] Example 3

[0099] Example 3 discloses a solvent-free polyurethane resin for automotive leather, which is prepared from component A and component B in a mass ratio of 100 / 60;

[0100] Wherein, the A component comprises the following components in parts by weight:

[0101]

[0102] The long-chain alkyl-modified silicone polyether diol in the A component is a diol with a molecular weight of 3000 obtained by reacting a long-chain side-chain hydrogenated silicone oil with an acryl polyether;

[0103] The B component includes the following components in parts by weight:

[0104]

[0105] The organosilicon-modified polyether diol in the B component is a diol with a molecular weight of 1000 synthesized by reacting low molecular weight linear hydroxyl-terminated polysiloxane (PDMS-OH) and allyl alcohol polyether.

[0106] The polyether diol in component A is polytetrahydrofuran diol with a molecular weight of 1000-3000.

[0107] The polyether triol of component A is polyoxypropylene triol with a molecular weight of 3000-6000; the polyether triol of component B is polyoxypropylene triol with a molecular weight of 500-1000.

[0108] The chain extender in component A is any one of ethylene glycol (EG), 1,3-propylene glycol (1,3-PG), 1,4-butanediol (1,4-BG) and 1,5-pentanediol (1,5-PG).

[0109] The catalyst in component A is any one of BiCAT 8106, BiCAT 8108, BiCAT 8124, BiCAT3228, BorchiKat 22, Borchi Kat 24, BiCAT 4130, BiCAT 4232, MB20 and the phenolate, formates and hydrochlorides of the above-mentioned organometallic catalysts; the catalyst used in component B is the metal catalyst MB-20.

[0110] The flame retardant in component A is an environmentally friendly halogen-free flame retardant of the aluminum hypophosphite type.

[0111] The diisocyanate in component B is any one of 4,4'-diphenylmethane diisocyanate (MDI), a mixture of 2,4-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate (IPDI), and 4,4'-dicyclohexylmethane diisocyanate (HMDI).

[0112] Example 3 also discloses a method for preparing a solvent-free polyurethane resin for automotive leather, comprising the following steps:

[0113] (1) Preparation of long-chain side chain hydrogen-containing silicone oil:

[0114] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, and 200 g of tetramethylcyclotetrasiloxane, 100 g of hexamethyldisiloxane and 250 g of octamethylcyclotetrasiloxane were added to the flask. 2 g of H2SO4 was added as a catalyst, and the mixture was reacted at 50°C for 8 hours and then cooled to room temperature. Na2CO3 was added for neutralization and then vacuum filtered to remove the solid components, and then high-temperature distillation was performed at 120°C to obtain long-chain hydrogen-containing siloxane.

[0115] (2) Preparation of long-chain alkyl-modified silicone polyether diols:

[0116] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, 400 g of a long-chain hydrogen-containing organosiloxane and 200 g of allyl alcohol polyether were added into the flask at a ratio of n(Si-H):n(double bond) of 1:1.2, 10 g of an isopropanol solution of 50 mg / g chloroplatinic acid was added as a catalyst, the reaction temperature was controlled at 80°C, and after reacting for 5-6 hours, a long-chain alkyl-modified organosilicon polyether diol was prepared by vacuum distillation, and the molecular weight was measured to be 3000.

[0117] (3) Preparation of silicone-modified polyether diol:

[0118] A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, and 200 g of low molecular weight linear hydroxyl-terminated polysiloxane (PDMS-OH) and 330 g of allyl alcohol polyether were added into the flask at a ratio of n(Si-H):n(double bond) of 1:1.15, and 10 g of an isopropanol solution of 50 mg / g chloroplatinic acid was added as a catalyst. The reaction temperature was controlled at 80°C, and after reacting for 5-6 hours, the organosilicon-modified polyether diol was prepared by reduced pressure distillation, and the molecular weight was measured to be 1000.

[0119] (4) Preparation of component A:

[0120] 60g of long-chain alkyl modified silicone polyether, 20g of polyether diol PTMG-1000, 10g of polyether triol DEP-330N and 10g of chain extender BG were put into a reactor, stirred and heated to 65°C, then 100g of 3852 flame retardant was added and stirred evenly, the flame retardant was completely dissolved in the polyol, and then 0.15g of catalyst BiCAT 3228 was added when the temperature dropped to 35°C, stirred evenly, and component A was obtained, which was sealed and packaged for standby use.

[0121] (5) Preparation of component B:

[0122] 50g of diisocyanate MDI and 0.1g of phosphoric acid were added into the reactor and stirred evenly. Then, 34g of silicone-modified polyether diol, 16g of polyether triol DMN-700 and 0.1g of catalyst MB-20 were added and the temperature was raised to 80°C. The reaction was carried out for 4h. The NCO% was then determined to be 10%. After the determination was qualified, the material was discharged to obtain component B, which was then sealed and packaged for later use.

[0123] (6) Preparation of solvent-free polyurethane resin for automotive leather seats: The obtained component A and component B are mixed evenly in a mass ratio of 100:60 using a low-pressure casting machine, and then coated on release paper and dried at 130°C to obtain a solvent-free polyurethane resin for automotive leather.

[0124] Example 3 also discloses the application of the above solvent-free polyurethane resin for automobile leather in the preparation of solvent-free polyurethane synthetic leather for automobile. When applied, firstly, a water-based surface layer AW-50Y is scraped on the release paper, and after drying, the solvent-free polyurethane resin for automobile leather seats is applied to the dried fabric, and then pre-reacted in an oven at 130°C for 100s, and the base fabric is directly attached thereto, and after being pressed by a roller, it is placed in an oven at 130°C for aging for 10 minutes, and then rolled up to obtain solvent-free automobile leather.

[0125] Comparative Example 1: Preparation of solvent-free polyurethane resin for automotive leather:

[0126] The commonly used automotive leather resin 3051A / B combination on the market is fully mixed in a ratio of 100 / 72, and then evenly poured and coated on the release paper with a surface coating, pre-reacted in an oven at 130°C for 60s, and the base cloth is directly attached thereto. After being rolled, it is placed in an oven at 130°C for aging for 10 minutes, and then rolled up to obtain solvent-free synthetic leather for automotive leather seats.

[0127] Comparative Example 2: The long-chain alkyl-modified silicone polyether and silicone-modified polyether diol in Example 1 are replaced with polyether diol PTMG-1000, and component A is obtained according to the same steps. It is fully mixed with the above-mentioned component B in a ratio of 100 / 72, and then evenly poured and coated on the release paper with a surface coating, pre-reacted in an oven at 130°C for 60s, and the base cloth is directly attached thereto. After being pressed by a pressure roller, it is placed in an oven at 130°C for aging for 10min, and then rolled up to obtain solvent-free automotive leather.

[0128] The performance tests of the above-mentioned Examples 1-3 and Comparative Examples 1-2 are as follows:

[0129] High-temperature wrapping and ironing performance test: The obtained automobile leather is needle-punched and then wrinkled, and then wrapped on a wooden board. It is then ironed with a high-temperature electric iron at 160°C for 10 seconds to observe whether the surface of the automobile leather is smooth.

[0130] Car leather crease ironing test: The obtained car leather is folded and squeezed to obtain creases, and then ironed at 160°C for 10 seconds to observe whether the creases disappear. The test results are shown in Table 1:

[0131] Table 1 Test results

[0132] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Smooth surface smooth smooth smooth With wavy pattern With wavy pattern Crease marks none none none Slight creases There are creases Peel strength (N / 3cm) 114 121 118 104 92 Cold resistance (-20℃, 30,000) qualified qualified qualified qualified qualified

[0133] Comparative Example 1 is a solvent-free polyurethane resin formula for automotive leather that is currently used more on the market. By comparing the embodiments of the present invention with the comparative examples, it is found that the solvent-free polyurethane resin for automotive leather seats prepared by the present invention has significant advantages in the coating performance of current automotive seat leather. Comparison of Comparative Example 2 with Examples 1-3 shows that the addition of long-chain alkyl-modified silicone polyether diol and silicone-modified polyether diol improves the coating performance of automotive leather, and the automotive leather prepared by the solvent-free polyurethane resin for automotive leather seats of the present invention is relatively excellent in tests such as peeling strength, aging performance, hot pressing performance, cold resistance, wear resistance and hydrolysis resistance. Therefore, it is feasible to use it on automotive leather.

[0134] The sources of raw materials used in this embodiment are as follows:

[0135] Tetramethylcyclotetrasiloxane is produced by Jiangxi Xinjiayi New Materials Co., Ltd.; hexamethyldisiloxane and octamethylcyclotetrasiloxane are produced by Dow Corning; MDI is a diisocyanate produced by Yantai Wanhua Company; catalyst MB-20 is produced by Air Products and Chemicals, Inc.; catalysts BiCAT 3228 and BiCAT 8108 are catalysts of Aosjia Materials Technology Co., Ltd. and Leading Chemicals Company of the United States, respectively; 3852 flame retardant is produced by Double Bond Chemical Co., Ltd. of Taiwan, China; PDMS-OH is a molecular weight linear terminal hydroxyl polysiloxane of Guangzhou Siloke Chemical Co., Ltd.; water-based surface layer AW-50Y and 3051A / B resins are polyurethane resins produced by Hefei Amway Polyurethane New Materials Co., Ltd.; 1,4-butanediol, isopropanol, allyl alcohol polyether, PTMG-1000, DEP-330N, etc. are commercially available products.

[0136] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0137] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A solvent-free polyurethane resin for automotive leather, characterized in that: It is prepared from component A and component B in a mass ratio of 100:60-100:80; Wherein, the A component comprises the following components in parts by weight: The long-chain alkyl-modified silicone polyether diol in the A component is a diol with a molecular weight of 3000 obtained by reacting a long-chain side-chain hydrogenated silicone oil with an acryl polyether; The B component includes the following components in parts by weight: The organosilicon-modified polyether diol in the B component is a diol with a molecular weight of 1000 synthesized by reacting low molecular weight linear hydroxyl-terminated polysiloxane (PDMS-OH) and allyl alcohol polyether.

2. The solvent-free polyurethane resin for automotive leather according to claim 1, characterized in that: The polyether diol in the component A is polytetrahydrofuran diol with a molecular weight of 1000-3000.

3. The solvent-free polyurethane resin for automotive leather according to claim 1, characterized in that: The polyether triol of component A is polyoxypropylene triol with a molecular weight of 3000-6000; the polyether triol of component B is polyoxypropylene triol with a molecular weight of 500-1000.

4. The solvent-free polyurethane resin for automotive leather according to claim 1, characterized in that: The chain extender in the component A is any one of ethylene glycol, 1,3-propylene glycol, 1,4-butanediol and 1,5-pentanediol.

5. The solvent-free polyurethane resin for automotive leather according to claim 1, characterized in that: The catalyst in the A component is any one of BiCAT 8106, BiCAT 8108, BiCAT 8124, BiCAT3228, Borchi Kat 22, Borchi Kat24, BiCAT 4130, BiCAT 4232, MB20 and the phenolate, formates and hydrochlorides of the above-mentioned organometallic catalysts; the catalyst used in the B component is the metal catalyst MB-20.

6. The solvent-free polyurethane resin for automotive leather according to claim 1, characterized in that: The flame retardant in the A component is an environmentally friendly halogen-free flame retardant of aluminum hypophosphite type.

7. The solvent-free polyurethane resin for automotive leather according to claim 1, characterized in that: The diisocyanate in the B component is any one of 4,4'-diphenylmethane diisocyanate, a mixture of 2,4-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

8. A method for preparing a solvent-free polyurethane resin for automotive leather according to any one of claims 1 to 7, characterized in that: The steps include: (1) Preparation of long-chain side chain hydrogen-containing silicone oil: A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, different hydrogen-containing siloxanes and a certain amount of H2SO4 as a catalyst were added into the flask, reacted at 50°C for 8 hours and then cooled to room temperature, and after neutralization by adding Na2CO3, the solid components were removed by vacuum filtration, and then high-temperature distillation was performed at 120°C to obtain long-chain hydrogen-containing siloxanes; (2) Preparation of long-chain alkyl-modified silicone polyether diols: A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, and long-chain hydrogen-containing organosiloxane and allyl alcohol polyether with a ratio of n(Si-H):n(double bond) of 1:1.2 were added into the flask. An isopropanol solution containing 50 mg / g of chloroplatinic acid was used as a catalyst. The reaction temperature was controlled at 80°C. After reacting for 5-6 hours, a long-chain alkyl-modified organosilicon polyether diol was prepared by vacuum distillation, and the molecular weight was measured to be 3000. (3) Preparation of silicone-modified polyether diols: A three-necked flask equipped with a magnetic stirrer, a thermometer, a N2 inlet tube and an air-cooled condenser was installed in a mantle-type resistance heater, and low molecular weight linear hydroxyl-terminated polysiloxane and allyl alcohol polyether with n(Si-H):n(double bond) being 1:1.15 were added into the flask, and an isopropanol solution containing 50 mg / g of chloroplatinic acid was selected as the catalyst. The reaction temperature was controlled at 80°C, and after reacting for 5-6 hours, the organosilicon-modified polyether diol was prepared by vacuum distillation, and the measured molecular weight was 1000; (4) Preparation of component A: Put long-chain alkyl modified silicone polyether diol, polyether diol, polyether triol and chain extender into a reaction kettle, then add catalyst and flame retardant in sequence, heat to 50-90°C and stir for 2-4h to obtain component A; (5) Preparation of component B: Add diisocyanate and phosphoric acid into the reaction kettle and stir evenly, then add organosilicon-modified polyether diol, polyether triol and catalyst and heat to 80-120°C, stir for 2-5h, then measure NCO%, and discharge the material after the measurement is qualified, thus obtaining component B; (6) Preparation of solvent-free polyurethane resin for automotive leather: The obtained component A and component B are mixed at a mass ratio of 100:60-100:80, then coated on release paper, and dried at 130° C. to obtain a solvent-free polyurethane resin for automotive leather.

9. Use of the solvent-free polyurethane resin for automobile leather as claimed in any one of claims 1 to 7 in the preparation of solvent-free polyurethane synthetic leather for automobiles.

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