Environment-friendly high-physical-property brightener for automobile seat leather and preparation method of environment-friendly high-physical-property brightener

Abstract

The invention provides an environment-friendly high-physical-property brightener for automobile seat leather and a preparation method of the environment-friendly high-physical-property brightener. The preparation method comprises the following steps: a) dehydrating dihydric alcohol, mixing the dehydrated dihydric alcohol with isocyanate, carrying out a first reaction, adding a hydrophilic chain extender and a small molecule chain extender, carrying out a second reaction, adding a catalyst and acetone, and carrying out a third reaction to obtain a reaction mixture; and b) neutralizing the reaction mixture obtained in the step a), adding water for dispersion, then adding an amine chain extender for mixing, and finally removing acetone in vacuum to obtain the environment-friendly high-physical-property brightener for the automobile seat leather. Compared with the prior art, the preparation method provided by the invention has the advantages that specific raw materials are adopted and matched with specific process steps, overall better interaction is realized, and the obtained product has excellent comprehensive physical properties and excellent bending resistance, contains extremely low solvent and meets the green and environment-friendly requirements of automobile seat cushion leather.

Description

Technical Field

[0001] The invention relates to the technical field of waterborne polyurethane, and more specifically to an environmentally friendly high-physical-property brightener for automobile seat leather and a preparation method thereof. Background Art

[0002] As a representative of high performance and high requirements in the existing leather application field, car seat leather has high market value and development prospects. After a series of coating processes, the car seat leather needs to be coated with a bright layer on the surface. As the last coating of the car seat coating, the bright layer needs to have high comprehensive performance; among them, the coating brightener not only needs to be resistant to wear, dry and wet rubbing, solvents, etc., but also needs good resistance to high and low temperature bending. In addition, car seat leather also has high requirements for environmental performance. The coated car seat leather requires extremely low VOC and does not contain regulatory restrictions. Due to the high requirements for the environmental performance of car seat leather, the brightener must also meet the corresponding requirements. The prepared brightener is basically solvent-free and does not contain restricted substances. Summary of the invention

[0003] In view of this, the object of the present invention is to provide an environmentally friendly high-property brightener for automobile seat leather and a preparation method thereof. The preparation method provided by the present invention adopts an acetone method, and finally removes the acetone by vacuum. The acetone content of the prepared brightener is controlled below 500ppm, and no restricted substances are used, thereby meeting the requirements for automobile seat leather finishing.

[0004] The present invention provides a method for preparing an environmentally friendly high-property brightener for automobile seat leather, comprising the following steps:

[0005] a) dehydrating the diol, mixing it with isocyanate, performing a first reaction, adding a hydrophilic chain extender and a small molecule chain extender, performing a second reaction, and then adding a catalyst and acetone, performing a third reaction, to obtain a reaction mixture;

[0006] b) neutralizing the reaction mixture obtained in step a), adding water to disperse it, adding an amine chain extender to mix it, and finally removing acetone in vacuum to obtain an environmentally friendly high-property brightener for automobile seat leather.

[0007] Preferably, the dehydration method in step a) is vacuum dehydration at 100° C. to 110° C., and the moisture content is controlled below 0.05%.

[0008] Preferably, the diol in step a) is selected from one or more of polycaprolactone diol, crystalline polycarbonate diol, liquid polycarbonate diol, and polytetramethylene glycol; the molecular weight of the diol is 800 to 1200;

[0009] The isocyanate is selected from isophorone diisocyanate and / or dicyclohexylmethane-4,4'-diisocyanate;

[0010] The mass ratio of the isocyanate to the diol is (180-200):260.

[0011] Preferably, the temperature of the first reaction in step a) is 90° C. to 92° C., and the time is 1 h to 2 h.

[0012] Preferably, the hydrophilic chain extender in step a) is dimethylolbutyric acid; the small molecule chain extender is selected from trimethylolpropane and / or 1,4-butanediol;

[0013] The mass ratio of the hydrophilic chain extender, the small molecule chain extender and the diol is (25-30): (4-5): 260;

[0014] The temperature of the second reaction is 90° C. to 92° C., and the time is 2 h to 3 h.

[0015] Preferably, the catalyst in step a) is an organic bismuth catalyst;

[0016] The mass ratio of the catalyst, acetone and diol is (0.1-0.4): (300-600): 260;

[0017] The temperature of the third reaction is 60°C to 65°C, and the time is 3h to 4h.

[0018] Preferably, the neutralization process in step b) uses triethylamine, and its amount is 5% to 10% of the mass of the diol;

[0019] The amount of water used is 2 to 5 times the mass of the diol;

[0020] The dispersion time is 1 min to 5 min.

[0021] Preferably, the amine chain extender in step b) is selected from one or more of ethylenediamine, diethylenetriamine, and isophoronediamine;

[0022] The mass ratio of the amine chain extender to the diol is (15-20):260;

[0023] The mixing method is stirring; the stirring time is 1 hour to 2 hours.

[0024] Preferably, the vacuum degree of the vacuum removal of acetone in step b) is less than -0.08 mPa, the temperature is 53°C to 55°C, and the time is 2h to 3h.

[0025] The present invention also provides an environmentally friendly high-property brightener for automobile seat leather, which is prepared by the preparation method described in the above technical solution.

[0026] The present invention provides a method for preparing an environmentally friendly high-property brightener for automotive seat leather, comprising the following steps: a) dehydrating a diol, mixing it with an isocyanate, performing a first reaction, then adding a hydrophilic chain extender and a small molecule chain extender, performing a second reaction, then adding a catalyst and acetone, performing a third reaction, and obtaining a reaction mixture; b) neutralizing the reaction mixture obtained in step a), adding water to disperse it, then adding an amine chain extender to mix it, and finally removing the acetone in a vacuum to obtain an environmentally friendly high-property brightener for automotive seat leather. Compared with the prior art, the preparation method provided by the present invention adopts specific raw materials and cooperates with specific process steps to achieve overall better interaction, and the obtained product has excellent comprehensive physical properties, and at the same time has excellent bending resistance, and contains extremely low solvents, which meets the green environmental protection requirements of automotive seat cushion leather.

[0027] At the same time, the preparation method provided by the present invention has simple process, mild conditions, easy control, and broad application prospects. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The present invention provides a method for preparing an environmentally friendly high-property brightener for automobile seat leather, comprising the following steps:

[0030] a) dehydrating the diol, mixing it with isocyanate, performing a first reaction, adding a hydrophilic chain extender and a small molecule chain extender, performing a second reaction, and then adding a catalyst and acetone, performing a third reaction, to obtain a reaction mixture;

[0031] b) neutralizing the reaction mixture obtained in step a), adding water to disperse it, adding an amine chain extender to mix it, and finally removing acetone in vacuum to obtain an environmentally friendly high-property brightener for automobile seat leather.

[0032] The invention firstly dehydrates diol and mixes it with isocyanate to carry out a first reaction, then adds a hydrophilic chain extender and a small molecule chain extender to carry out a second reaction, and then adds a catalyst and acetone to carry out a third reaction to obtain a reaction mixture.

[0033] In the present invention, the diol is preferably selected from one or more of polycaprolactone diol, crystalline polycarbonate diol, liquid polycarbonate diol, polytetramethylene glycol, more preferably liquid polycarbonate diol and / or polytetramethylene glycol; the molecular weight of the diol is preferably 800 to 1200, more preferably 1000. The present invention has no particular limitation on the source of the diol, and commercially available products known to those skilled in the art may be used.

[0034] In the present invention, the dehydration method is preferably vacuum dehydration at 100°C to 110°C, and the moisture content is preferably controlled below 0.05%; after dehydration, due to the high temperature, the present invention preferably reduces the temperature to 50°C to 70°C before mixing with isocyanate.

[0035] In the present invention, the isocyanate is preferably selected from isophorone diisocyanate and / or dicyclohexylmethane-4,4'-diisocyanate, more preferably dicyclohexylmethane-4,4'-diisocyanate. The present invention has no particular limitation on the source of the isocyanate, and commercially available products known to those skilled in the art can be used.

[0036] In the present invention, the mass ratio of the isocyanate to the diol is preferably (180-200):260.

[0037] In the present invention, the device for the first reaction is a reactor, and the subsequent second and third reactions all use the same device, which will not be repeated in the present invention; the temperature of the first reaction is preferably 90°C to 92°C, and the time is preferably 1h to 2h; after completing the first reaction, the present invention preferably cools the temperature to 50°C to 70°C, and then adds a hydrophilic chain extender and a small molecule chain extender.

[0038] In the present invention, the hydrophilic chain extender is preferably dimethylolbutyric acid; the small molecule chain extender is preferably selected from trimethylolpropane and / or 1,4-butanediol, and more preferably trimethylolpropane. The present invention has no particular restrictions on the sources of the hydrophilic chain extender and the small molecule chain extender, and commercial products known to those skilled in the art can be used.

[0039] In the present invention, the mass ratio of the hydrophilic chain extender, the small molecule chain extender and the diol is preferably (25-30):(4-5):260.

[0040] In the present invention, the temperature of the second reaction is preferably 90° C. to 92° C., and the time is preferably 2 h to 3 h. After the second reaction is completed, the present invention preferably cools the reaction mixture to 50° C. to 70° C., and then adds a catalyst and acetone.

[0041] In the present invention, the catalyst is preferably an organic bismuth catalyst. The present invention has no particular limitation on the sources of the catalyst and acetone, and commercially available products known to those skilled in the art may be used.

[0042] In the present invention, the mass ratio of the catalyst, acetone and diol is preferably (0.1-0.4):(300-600):260.

[0043] In the present invention, the temperature of the third reaction is preferably 60°C to 65°C, and the time is preferably 3h to 4h; after the third reaction is completed, the present invention preferably cools the temperature to 40°C to 50°C to obtain a reaction mixture.

[0044] After obtaining the reaction mixture, the present invention neutralizes the reaction mixture, adds water to disperse it, then adds an amine chain extender to mix it, and finally removes acetone in vacuum to obtain an environmentally friendly high-property brightener for automobile seat leather.

[0045] In the present invention, triethylamine is preferably used in the neutralization process, and its usage is preferably 5% to 10% of the mass of the diol.

[0046] In the present invention, the amount of water used is preferably 2 to 5 times the mass of the diol; and the dispersion time is preferably 1 to 5 minutes.

[0047] In the present invention, the amine chain extender is preferably selected from one or more of ethylenediamine, diethylenetriamine, and isophoronediamine, and more preferably ethylenediamine and isophoronediamine; in a preferred embodiment of the present invention, the mass ratio of ethylenediamine to isophoronediamine is (6-8):10.

[0048] The present invention has no special restrictions on the sources of the triethylamine and amine chain extender, and commercially available products known to those skilled in the art can be used; the water is preferably deionized water known to those skilled in the art.

[0049] In the present invention, the mass ratio of the amine chain extender to the diol is preferably (15-20):260.

[0050] In the present invention, the mixing method is preferably stirring; and the stirring time is preferably 1 hour to 2 hours.

[0051] In the present invention, the vacuum degree of the vacuum removal of acetone is preferably less than -0.08mPa, the temperature is preferably 53°C to 55°C, and the time is preferably 2h to 3h; after the vacuum removal of acetone, the obtained product is a solvent-free water-based polyurethane brightener emulsion, and its acetone content is less than or equal to 500ppm when tested.

[0052] The preparation method provided by the invention adopts an acetone method for preparation, and finally adopts vacuum to remove the acetone, so that the acetone content of the prepared brightener is controlled below 500 ppm, and no restricted substances are used, thereby meeting the requirements for the finishing of automobile seat cushion leather.

[0053] The present invention also provides an environmentally friendly high-property brightener for automobile seat leather, which is prepared by the preparation method described in the above technical solution. The present invention provides a high-property, solvent-free water-based polyurethane brightener with good comprehensive performance, which meets the requirements of automobile seat leather.

[0054] In a preferred embodiment of the present invention, the environmentally friendly high-property brightener for automobile seat leather, the soft segment adopts liquid polycarbonate diol (molecular weight of 1000) or liquid polycarbonate diol (molecular weight of 1000) and polytetramethylene ether diol (molecular weight of 1000), the hard segment adopts dicyclohexylmethane-4,4'-diisocyanate or dicyclohexylmethane-4,4'-diisocyanate and isophorone diisocyanate, acetone is used as solvent to adjust the viscosity of the prepolymer, A hydrophilic agent, chain extender, dimethylolbutyric acid and the like are added, and finally water is added for dispersion, and an amine chain extender, such as ethylenediamine or a combination of ethylenediamine and isophoronediamine, is used for post-chain extension, and acetone is removed from the obtained emulsion in vacuum to obtain a high-property automobile seat leather brightener; the prepared brightener has excellent comprehensive properties, such as abrasion resistance reaching level 4-5 for 1000 times, wet rubbing resistance reaching level 4-5 for 1000 times, alcohol rubbing resistance reaching level 4 for 100 times, room temperature flexing ≥100,000 times, and low temperature flexing (-20°C) ≥30,000 times.

[0055] The present invention provides a method for preparing an environmentally friendly high-property brightener for automotive seat leather, comprising the following steps: a) dehydrating a diol, mixing it with an isocyanate, performing a first reaction, then adding a hydrophilic chain extender and a small molecule chain extender, performing a second reaction, then adding a catalyst and acetone, performing a third reaction, and obtaining a reaction mixture; b) neutralizing the reaction mixture obtained in step a), adding water to disperse it, then adding an amine chain extender to mix it, and finally removing the acetone in a vacuum to obtain an environmentally friendly high-property brightener for automotive seat leather. Compared with the prior art, the preparation method provided by the present invention adopts specific raw materials and cooperates with specific process steps to achieve overall better interaction, and the obtained product has excellent comprehensive physical properties, and at the same time has excellent bending resistance, and contains extremely low solvents, which meets the green environmental protection requirements of automotive seat cushion leather.

[0056] At the same time, the preparation method provided by the present invention has simple process, mild conditions, easy control, and broad application prospects.

[0057] In order to further illustrate the present invention, the following examples are provided for detailed description. The raw materials used in the following examples of the present invention are all commercially available.

[0058] Example 1

[0059] 260 g of liquid polycarbonate diol (molecular weight 1000) was vacuum dehydrated at 100-110°C to control the moisture content below 0.05%, cooled to 60°C, 190 g of dicyclohexylmethane-4,4'-diisocyanate was added, reacted at 90-92°C for 1.5 h, cooled to 60°C, 26 g of dihydroxymethylbutyric acid and 4.5 g of trimethylolpropane were added, reacted at 90-92°C for 2 h, cooled to 60°C, and 0.2 g of organic bismuth catalyst was added. The solvent-free aqueous polyurethane brightener emulsion was obtained by adding 18 g of triethylamine and 400 g of acetone at 63-65 ° C for 4 h, cooling to 50 ° C, adding 18 g of triethylamine for neutralization, adding 930 g of dispersing water for dispersion, and dispersing for 2-3 min. Then, 7 g of ethylenediamine and 10 g of isophoronediamine were added to mix the chain extension liquid. After stirring for 2 h, the acetone was removed in vacuo under the conditions of <-0.08 mPa, 53-55 ° C, and removal for 2.5 h. The acetone test value was 450 ppm, and a solvent-free aqueous polyurethane brightener emulsion was obtained.

[0060] Example 2

[0061] 200g of liquid polycarbonate diol (molecular weight 1000) and 60g of polytetramethylene glycol (molecular weight 1000) were vacuum dehydrated at 100-110°C, the moisture content was controlled below 0.05%, cooled to 60°C, 190g of dicyclohexylmethane-4,4'-diisocyanate was added, reacted at 90-92°C for 1.5h, cooled to 60°C, 26g of dihydroxymethylbutyric acid and 4.5g of trimethylolpropane were added, reacted at 90-92°C for 2h, cooled to 60°C , add 0.2g of organic bismuth catalyst and 400g of acetone, continue to react at 60-65℃ for 4h, cool to 50℃, add 18g of triethylamine for neutralization, add 930g of dispersing water for dispersion, disperse for 2-3min, add 7g of ethylenediamine and 10g of isophoronediamine to mix the chain extension liquid, stir for 2h and remove acetone in vacuum, the vacuum conditions are: <-0.08mPa, 53-55℃, and remove for 2.5h; the acetone test value is 450ppm, and a solvent-free water-based polyurethane brightener emulsion is obtained.

[0062] Comparative Example 1

[0063] 260g of polytetrahydrofuran ether diol (molecular weight 1000) was vacuum dehydrated at 100-110°C, the moisture content was controlled below 0.05%, cooled to 60°C, 190g of dicyclohexylmethane-4,4'-diisocyanate was added, the reaction was carried out at 90-92°C for 1.5h, cooled to 60°C, 26g of dihydroxymethylbutyric acid and 4.5g of trimethylolpropane were added, the reaction was carried out at 90-92°C for 2h, cooled to 60°C, and 0.1g of organic Bismuth catalyst and acetone 400g, continue to react at 60-65℃ for 4h, cool to 50℃, add triethylamine 18g for neutralization, add dispersing water 930g for dispersion, disperse for 2-3min, add ethylenediamine 10.5g as chain extension liquid, stir for 2h and remove acetone in vacuum, vacuum conditions are: <-0.08mPa, 53-55℃, remove for 2.5h; acetone test value is 450ppm, and solvent-free waterborne polyurethane brightener emulsion is obtained.

[0064] Comparative Example 2

[0065] 260g of polycaprolactone diol (molecular weight 1000) was vacuum dehydrated at 100-110°C to control the moisture content below 0.05%, cooled to 60°C, 190g of dicyclohexylmethane-4,4'-diisocyanate was added, reacted at 90-92°C for 1.5h, cooled to 60°C, 26g of dihydroxymethylbutyric acid and 4.5g of trimethylolpropane were added, reacted at 90-92°C for 2h, cooled to 60°C, and 0.1g of organic Bismuth catalyst and acetone 400g, continue to react at 60-65℃ for 4h, cool to 50℃, add 18g triethylamine for neutralization, add 930g dispersion water for dispersion, after dispersion for 2-3min, add 10.5g ethylenediamine as chain extension liquid, stir for 2h and remove acetone in vacuum, vacuum conditions are: <-0.08mPa, 53-55℃, remove for 2.5h; acetone test value is 450ppm, and solvent-free waterborne polyurethane brightener emulsion is obtained.

[0066] Performance Testing:

[0067] (1) Fix the sample with the front side facing up on the rotating platform and install the selected CS-10 grinding wheel on the support bar. After selecting a load of 1kg, lower the support bar so that the grinding wheel contacts the surface of the sample, and connect and turn on the dust suction device. Start the instrument and test according to the number of rotations set by the counter. After the test, remove the sample, check and record the wear of the sample, and test it with a gray sample card according to GB / T 250-2008 "Gray Sample Card for Color Fastness Tests for Textiles to Assess Color Change".

[0068] (2) The alcohol rubbing and wet rubbing operations are as follows: fix the white felt soaked in deionized water or alcohol and squeezed on the test head (500g) of the friction color fastness tester, then fix the leather sample on the test table of the instrument with the smooth side facing up and stretch it 10% along the friction direction; put down the test head with the felt, start the instrument, stop after 1000 times, remove the felt, and rate the color adhesion of the felt in accordance with the requirements of GB / T 251.

[0069] (3) The normal low temperature bending test method is: use a low temperature bending box, set the number of times, and take it out after reaching the set number of times to observe whether it is cracked.

[0070] The test results are shown in Table 1 below.

[0071] Table 1

[0072] Example 1 Example 2 Comparative Example 1 Comparative Example 2 Table wear tester (CS-10, 1kg, 1000 times, grade) Good 4-5 level Good 4-5 level Good 3-4 Good 3-4 Rubbing alcohol (100 times) Good 4-5 level Good level 4 Better 3 Good 3-4 Wet wipe (1000 times) Good 4-5 level Good 4-5 level Good 3-4 Good level 4 Normal temperature bending (25℃) ≥100,000 times ≥100,000 times ≥100,000 times ≥80,000 times Low temperature bending (-20℃) ≥30,000 times ≥30,000 times ≥30,000 times ≥30,000 times

[0073] Experimental results show that the environmentally friendly high-physical property brightener for automobile seat leather prepared by the preparation method provided by the present invention has excellent comprehensive physical properties and flexural resistance, and contains extremely low solvents, which meets the green environmental protection requirements of automobile seat cushion leather.

[0074] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing an environmentally friendly high-property brightener for automobile seat leather, comprising the following steps: a) dehydrating the diol, mixing it with isocyanate, performing a first reaction, adding a hydrophilic chain extender and a small molecule chain extender, performing a second reaction, and then adding a catalyst and acetone, performing a third reaction, to obtain a reaction mixture; b) neutralizing the reaction mixture obtained in step a), adding water to disperse it, adding an amine chain extender to mix it, and finally removing acetone in vacuum to obtain an environmentally friendly high-property brightener for automobile seat leather.

2. The preparation method according to claim 1, characterized in that: The dehydration method in step a) is vacuum dehydration at 100° C. to 110° C., and the moisture content is controlled below 0.05%.

3. The preparation method according to claim 1, characterized in that: The diol in step a) is selected from one or more of polycaprolactone diol, crystalline polycarbonate diol, liquid polycarbonate diol, and polytetramethylene glycol; the molecular weight of the diol is 800 to 1200; The isocyanate is selected from isophorone diisocyanate and / or dicyclohexylmethane-4,4'-diisocyanate; The mass ratio of the isocyanate to the diol is (180-200):

260.

4. The preparation method according to claim 1, characterized in that: The temperature of the first reaction in step a) is 90° C. to 92° C., and the time is 1 h to 2 h.

5. The preparation method according to claim 1, characterized in that: In step a), the hydrophilic chain extender is dimethylolbutyric acid; the small molecule chain extender is selected from trimethylolpropane and / or 1,4-butanediol; The mass ratio of the hydrophilic chain extender, the small molecule chain extender and the diol is (25-30): (4-5): 260; The temperature of the second reaction is 90° C. to 92° C., and the time is 2 h to 3 h.

6. The preparation method according to claim 1, characterized in that: The catalyst in step a) is an organic bismuth catalyst; The mass ratio of the catalyst, acetone and diol is (0.1-0.4): (300-600): 260; The temperature of the third reaction is 60°C to 65°C, and the time is 3h to 4h.

7. The preparation method according to claim 1, characterized in that: The neutralization process in step b) uses triethylamine in an amount of 5% to 10% of the mass of the diol; The amount of water used is 2 to 5 times the mass of the diol; The dispersion time is 1 min to 5 min.

8. The preparation method according to claim 1, characterized in that: The amine chain extender in step b) is selected from one or more of ethylenediamine, diethylenetriamine, and isophoronediamine; The mass ratio of the amine chain extender to the diol is (15-20):260; The mixing method is stirring; the stirring time is 1 hour to 2 hours.

9. The preparation method according to claim 1, characterized in that: The vacuum degree of the vacuum removal of acetone in step b) is less than -0.08 mPa, the temperature is 53° C. to 55° C., and the time is 2 h to 3 h.

10. An environmentally friendly high-property brightener for automobile seat leather, characterized in that: The preparation method is described in any one of claims 1 to 9.