阅读说明：本技术 一种彩色水性聚氨酯及其制备方法 (Colored waterborne polyurethane and preparation method thereof ) 是由 庄君新 霍俊丽 陈志坚 于 2021-06-11 设计创作，主要内容包括：本发明公开了一种彩色水性聚氨酯,由以下重量份的原料制备而成：二异氰酸酯50-200份,常规二元醇150-350份,彩色聚酯多元醇50-120分,小分子扩链剂1-20份,亲水扩链剂10-45份,去离子水400-1200份；所述彩色聚酯多元醇由以下重量份的原料制备而成：二元酸20-100份、小分子扩链剂30-110份、含活性羟基的染料5-20份、钛酸四丁酯0.1-0.5份,其中羟基与羧基摩尔数为1.1-1.3:1。本发明的彩色水性聚氨酯通过化学反应,将彩色基团原位合成到聚氨酯分子链中,染料与聚氨酯通过化学键结合,解决了色迁移、耐摩擦牢度和耐水性牢度低的弊病；同时,由于染料与聚氨酯在同一分子结构,属于一个体系,稳定性更强,无浮色现象。应用于超纤革,耐水洗色牢度、耐摩擦色牢度、耐色迁移等级更高。(The invention discloses a colored waterborne polyurethane which is prepared from the following raw materials in parts by weight: 50-200 parts of diisocyanate, 350 parts of conventional dihydric alcohol 150-; the color polyester polyol is prepared from the following raw materials in parts by weight: 20-100 parts of dibasic acid, 30-110 parts of micromolecular chain extender, 5-20 parts of dye containing active hydroxyl and 0.1-0.5 part of tetrabutyl titanate, wherein the mole number of the hydroxyl and carboxyl is 1.1-1.3: 1. The color waterborne polyurethane disclosed by the invention has the advantages that the color groups are synthesized into a polyurethane molecular chain in situ through chemical reaction, and the dye and the polyurethane are combined through chemical bonds, so that the defects of low color migration, low rubbing fastness and low water resistance fastness are overcome; meanwhile, the dye and the polyurethane are in the same molecular structure, so that the dye belongs to a system, the stability is higher, and the flooding phenomenon is avoided. The color fastness to washing, the color fastness to rubbing and the color migration resistance of the super-fiber leather are higher.)

1. The color waterborne polyurethane is characterized by being prepared from the following raw materials in parts by weight: 50-200 parts of diisocyanate, 350 parts of conventional dihydric alcohol 150-;

the color polyester polyol is prepared from the following raw materials in parts by weight: 20-100 parts of dibasic acid, 30-110 parts of micromolecular chain extender, 5-20 parts of dye containing active hydroxyl and 0.1-0.5 part of tetrabutyl titanate, wherein the mole number of the hydroxyl and carboxyl is 1.1-1.3: 1.

2. The colored waterborne polyurethane of claim 1, wherein the dibasic acid is any one or more of adipic acid, sebacic acid, and isophthalic acid.

3. The colored waterborne polyurethane of claim 1, wherein the small chain extender is any one or more of ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, and neopentyl glycol.

4. The colored waterborne polyurethane of claim 1, wherein the reactive hydroxyl group-containing dye is any one or more of a disperse yellow dye, an acid orange dye, and a lake blue dye.

5. The colored waterborne polyurethane of claim 1, wherein the diisocyanate is any one or more of hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, 1, 5-naphthalene diisocyanate, and p-phenylene diisocyanate.

6. The colored waterborne polyurethane of claim 1, wherein the diol is any one or more of polytetrahydrofuran diol, polyester diol and polypropylene glycol.

7. The colored waterborne polyurethane of claim 1, wherein the neutralizing agent is any one or more of triethylamine, dimethylethanolamine, triethanolamine, and diethanolamine.

8. A process for preparing the colored aqueous polyurethane according to any one of claims 1 to 7, comprising the steps of:

the method comprises the following steps: preparation of colored polyester polyol:

(1) weighing the weighed dibasic acid, the small molecular chain extender, the dye containing active hydroxyl and tetrabutyl titanate into a four-neck flask, heating to 60-80 ℃, and uniformly stirring the materials through ultrasonic dispersion and stirring;

(2) gradually heating to 240 ℃ and reacting for 3-4 hours;

(3) and (3) distilling water and residual monomers under reduced pressure, and detecting the water content, the acid value and the hydroxyl value to required values to obtain the color polyester polyol.

Step two: preparation of the colored waterborne polyurethane:

(1) dehydrating conventional dihydric alcohol, color polyester polyol and dimethylolpropionic acid at 120 deg.C under vacuum for 1 hr, cooling to 40-70 deg.C, adding neutralizer, stirring the raw materials to uniform and transparent, adding diisocyanate, reacting at 60-90 deg.C for 1-3 hr under mechanical stirring, adding small molecular chain extender, and reacting at 70-85 deg.C for 2-4 hr;

(2) and (3) dispersing the reaction solution in deionized water under high-speed stirring of 1500r/min, and stirring for 30 minutes to obtain the color waterborne polyurethane.

Technical Field

The invention relates to the field of polymer synthesis, in particular to a colored waterborne polyurethane and a preparation method thereof.

Background

China is the largest textile production and export country in the world, and the continuous and stable growth of textile export is crucial to ensuring foreign exchange storage, balance international collection and expenditure, stable Renminbi exchange rate, and solving the sustainable development of social employment and textile industry in China. Particularly, in recent years, the PU synthetic leather in China develops very rapidly, and according to statistics, the yield of the synthetic leather in China in 2019 is 328.28 ten thousand tons, which is increased by 9.6% on a par with the yield.

The waterborne polyurethane has the characteristics of good film forming property, excellent thermal and mechanical properties, water resistance, cold resistance, flexing resistance and the like due to the special molecular structure and aggregation state structure, and is widely applied to the fields of textile printing and dyeing, leather processing and the like.

Currently, polyurethane synthetic leather generally achieves different color styles by physically blending waterborne polyurethane and dye, and the existing blending technology has the following problems: the dye is combined with the waterborne polyurethane and the fabric through weak acting forces such as hydrogen bonds, Van der Waals force and the like, so that the color is not firm and is easy to migrate; in addition, the dye and the waterborne polyurethane are in a metastable state after being blended, and can be layered and float in the standing process, so that the preparation of the colored waterborne polyurethane is an effective way for solving the problems of the existing waterborne polyurethane products.

CN104193952B discloses a colored polyurethane emulsion for waterproof paint and a preparation method thereof, wherein the principle is that a colored chain extender is introduced at the polyurethane synthesis stage, and a chromophoric group is introduced into a polyurethane main chain; the method needs to adopt toluene diisocyanate with high reaction activity and a staged heating method (the reaction temperature is less than 120 ℃) to improve the reaction efficiency with the chromophoric group, so that the problem of low utilization rate of the chromogenic chain extender still exists while the application range is limited.

CN104693403B discloses a color polyurethane resin for synthetic leather and a preparation method thereof, the principle is that a dye containing dihydroxyl or primary amino groups is adopted to introduce chromophoric groups into polyurethane molecular chains in the polyurethane synthesis stage, so as to solve the problem of color migration; in the preparation process, an organic solvent is adopted, so that the pollution is caused and the potential safety hazard is also caused.

CN106496489B discloses a water-soluble color chain extender, a copolymer color polyurethane emulsion and a color polyurethane-acrylate copolymer emulsion and a preparation method thereof, wherein at least two amino groups are introduced into a water-soluble dye through modification, and then water-soluble color chain extender molecules are introduced into a polyurethane molecular chain in the polyurethane synthesis stage, so that the problem of color fastness is solved; however, the amino group reacts violently with the isocyanate group and emits a large amount of heat, the gel phenomenon is easily caused in the reaction stage, the synthesis process is not easy to control, and the potential safety hazard exists.

Although the chromophoric groups can be introduced into the molecular chain of polyurethane by the above methods, the problems of low utilization rate of dye and difficult control of reaction still exist, and the practical application of the chromophoric groups in industrial production is limited.

Disclosure of Invention

The invention aims to provide a colored waterborne polyurethane and a preparation method thereof. The color waterborne polyurethane disclosed by the invention has the advantages that the color groups are synthesized into a polyurethane molecular chain in situ through chemical reaction, and the dye and the polyurethane are combined through chemical bonds, so that the defects of low color migration, low rubbing fastness and low water resistance fastness are overcome; meanwhile, the dye and the polyurethane are in the same molecular structure, so that the dye belongs to a system, the stability is higher, and the flooding phenomenon is avoided. The color fastness to washing, the color fastness to rubbing and the color migration resistance of the super-fiber leather are higher.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

the color waterborne polyurethane is prepared from the following raw materials in parts by weight: 50-200 parts of diisocyanate, 350 parts of conventional dihydric alcohol 150-;

the color polyester polyol is prepared from the following raw materials in parts by weight: 20-100 parts of dibasic acid, 30-110 parts of micromolecular chain extender, 5-20 parts of dye containing active hydroxyl and 0.1-0.5 part of tetrabutyl titanate, wherein the mole number of the hydroxyl and carboxyl is 1.1-1.3: 1.

Preferably, the dibasic acid is any one or more of adipic acid, sebacic acid and isophthalic acid.

Preferably, the small-molecule chain extender is any one or more of ethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol and neopentyl glycol.

The colored waterborne polyurethane of claim 1, wherein the reactive hydroxyl group-containing dye is any one or more of a disperse yellow dye, an acid orange dye, and a lake blue dye.

Preferably, the diisocyanate is any one or more of hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, dicyclohexylmethane diisocyanate, benzylidene diisocyanate, 1, 5-naphthalene diisocyanate and p-phenylene diisocyanate.

Preferably, the diol is one or more of polytetrahydrofuran diol, polyester diol and polypropylene glycol.

Preferably, the neutralizing agent is one or more of triethylamine, dimethylethanolamine, triethanolamine and diethanolamine.

The invention also provides a preparation method of the color waterborne polyurethane, which comprises the following steps:

the method comprises the following steps: preparation of colored polyester polyol:

(1) weighing the weighed dibasic acid, the small molecular chain extender, the dye containing active hydroxyl and tetrabutyl titanate into a four-neck flask, heating to 60-80 ℃, and uniformly stirring the materials through ultrasonic dispersion and stirring;

(2) gradually heating to 240 ℃ and reacting for 3-4 hours;

(3) and (3) distilling water and residual monomers under reduced pressure, and detecting the water content, the acid value and the hydroxyl value to required values to obtain the color polyester polyol.

Step two: preparation of the colored waterborne polyurethane:

(1) dehydrating conventional dihydric alcohol, color polyester polyol and dimethylolpropionic acid at 120 deg.C under vacuum for 1 hr, cooling to 40-70 deg.C, adding neutralizer, stirring the raw materials to uniform and transparent, adding diisocyanate, reacting at 60-90 deg.C for 1-3 hr under mechanical stirring, adding small molecular chain extender, and reacting at 70-85 deg.C for 2-4 hr;

(2) and (3) dispersing the reaction solution in deionized water under high-speed stirring of 1500r/min, and stirring for 30 minutes to obtain the color waterborne polyurethane.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the color waterborne polyurethane disclosed by the invention has the advantages that the color groups are synthesized into a polyurethane molecular chain in situ through chemical reaction, and the dye and the polyurethane are combined through chemical bonds, so that the defects of low color migration, low rubbing fastness and low water resistance fastness are overcome; meanwhile, the dye and the polyurethane are in the same molecular structure, so that the dye belongs to a system, the stability is higher, and the flooding phenomenon is avoided. The color fastness to washing, the color fastness to rubbing and the color migration resistance of the super-fiber leather are higher.

Has the following advantages:

the color polyester polyol can react at high temperature (240 ℃) in the synthesis stage, which is much higher than the highest temperature of 120 ℃ in the polyurethane synthesis stage, so that the reaction efficiency and the utilization efficiency of the dye are obviously improved, free dye monomers in the polyester are reduced, the cost is saved, and the problem of color fastness is indirectly solved.

The dye and the reaction medium are better fused by an ultrasonic dispersion means in the synthesis stage of the color polyester polyol, and the utilization efficiency of the dye is further improved.

The color polyester polyol prepared by the invention has the reaction activity close to that of the conventional dihydric alcohol, is mild and easy to control when being applied to the polyurethane synthesis stage, and can be widely applied to industrial production.

The color waterborne polyurethane prepared by the invention adopts a self-made mixed system of color polyurethane polyol and conventional polyol, and can graft chromophoric groups to a polyurethane main chain more efficiently by adopting a conventional polyurethane synthesis process, thereby thoroughly solving the problems of low reactivity and poor color fastness of dyes.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present invention, the following description of the preferred embodiments of the present invention is provided in connection with specific examples, which should not be construed as limiting the present patent.

The test methods or test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials, unless otherwise indicated, are conventionally obtained commercially or prepared by conventional methods.

The structural formulas of the disperse yellow dye, the acid orange dye and the lake blue dye are respectively as follows:

a color waterborne polyurethane and a preparation method thereof comprise the following components: the preparation method of the colored polyester polyol comprises the following steps of: 20-100 parts of dibasic acid, 30-110 parts of micromolecular chain extender, 5-20 parts of dye containing active hydroxyl and 0.1-0.5 part of tetrabutyl titanate, wherein the mole number of the hydroxyl and carboxyl is 1.1-1.3: 1; step two: the preparation of the colored waterborne polyurethane is prepared from the following raw materials in parts by weight: 50-200 parts of diisocyanate, 350 parts of conventional dihydric alcohol 150-.

The dibasic acid is any one or a mixture of any two or more of adipic acid, sebacic acid and isophthalic acid in any proportion.

The chain extender is any one or a mixture of more than two of ethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol and neopentyl glycol in any proportion.

The color waterborne polyurethane and the preparation method thereof are characterized in that the dye containing active hydroxyl groups is any one of disperse yellow dye, acid orange dye and lake blue dye or a mixture of any two or more of the disperse yellow dye, the acid orange dye and the lake blue dye which are mixed in any proportion.

The diisocyanate is any one or a mixture of any two or more of hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, dicyclohexylmethane diisocyanate, benzylidene diisocyanate, 1, 5-naphthalene diisocyanate and p-phenylene diisocyanate which are mixed in any proportion.

The diol is one or a mixture of more than two of polytetrahydrofuran diol, polyester diol and polypropylene glycol mixed in any proportion.

The neutralizer is one of triethylamine, dimethylethanolamine, triethanolamine and diethanolamine.

A color waterborne polyurethane and a preparation method thereof comprise the following steps:

the method comprises the following steps: preparing color polyester polyol, (1) weighing the weighed dibasic acid, micromolecule chain extender, dye containing active hydroxyl and tetrabutyl titanate into a four-neck flask, heating to 60-80 ℃, and uniformly stirring the materials through ultrasonic dispersion and stirring; (2) gradually heating to 240 ℃ and reacting for 3-4 hours; (3) and (3) distilling water and residual monomers under reduced pressure, and detecting the water content, the acid value and the hydroxyl value to required values to obtain the color polyester polyol.

Step two: preparing the color waterborne polyurethane (1) dehydrating the conventional dihydric alcohol, the color polyester polyol and the dimethylolpropionic acid at 120 ℃ for 1 hour in vacuum, cooling to 40-70 ℃, adding a neutralizing agent, stirring the raw materials until the raw materials are uniform and transparent, adding diisocyanate, reacting for 1-3 hours at 60-90 ℃ under mechanical stirring, adding a small-molecule chain extender, and reacting for 2-4 hours at 70-85 ℃; (2) and (3) dispersing the reaction solution in deionized water under high-speed stirring of 1500r/min, and stirring for 30 minutes to obtain the color waterborne polyurethane.

Example 1

The method comprises the following steps: preparing color polyester polyol, (1) weighing 100 parts of weighed adipic acid, 51 parts of ethylene glycol, 10 parts of disperse yellow dye and 0.4 part of tetrabutyl titanate into a four-neck flask, heating to 80 ℃, and uniformly stirring the materials in an ultrasonic dispersion and stirring manner; (2) gradually heating to 240 ℃ and reacting for 4 hours; (3) decompressing to-0.09 Mpa to distill out water and residual monomer, detecting the water content is less than 0.05%, the acid value is less than 1mgKOH/g, the hydroxyl value is 52-58mgKOH/g, and obtaining the color polyester polyol.

Step two: preparing the colored waterborne polyurethane (1), namely, dehydrating 300 parts of polytetrahydrofuran ether glycol (the number average molecular weight is 2000), 100 parts of the colored polyester polyol obtained in the first step and 25 parts of dimethylolpropionic acid at 120 ℃ for 1 hour in vacuum, cooling to 50 ℃, adding 23 parts of triethylamine, stirring the raw materials until the raw materials are uniform and transparent, adding 92 parts of isophorone diisocyanate, reacting at 90 ℃ for 3 hours under mechanical stirring, adding 1.5 parts of neopentyl glycol, and reacting at 80 ℃ for 3 hours; (2) and (3) dispersing the reaction solution in 750 parts of deionized water under high-speed stirring of 1500r/min, and stirring for 30 minutes to obtain the color waterborne polyurethane.

Example 2

The method comprises the following steps: preparing color polyester polyol, (1) weighing 60 parts of adipic acid, 50 parts of sebacic acid, 71 parts of 1, 4-butanediol, 13 parts of acid orange dye containing active hydroxyl and 0.3 part of tetrabutyl titanate which are measured, putting the materials into a four-neck flask, heating to 80 ℃, and uniformly stirring the materials in an ultrasonic dispersion and stirring manner; (2) gradually heating to 240 ℃ and reacting for 4 hours; (3) and (3) distilling water and residual monomers under reduced pressure, and detecting that the water content is less than 0.05 percent, the acid value is less than 1mgKOH/g and the hydroxyl value is 52-58mgKOH/g to obtain the color polyester polyol.

Step two: preparing color waterborne polyurethane (1), namely, carrying out vacuum dehydration on 205 parts of polytetrahydrofuran diol (the number average molecular weight is 1000), 100 parts of polypropylene glycol (the number average molecular weight is 2000), 80 parts of color polyester polyol obtained in the first step and 30 parts of dimethylolpropionic acid at 120 ℃ for 1 hour, cooling to 50 ℃, adding 27 parts of triethylamine, stirring the raw materials until the raw materials are uniform and transparent, adding 215 parts of dicyclohexylmethane diisocyanate, reacting at 90 ℃ for 2 hours under mechanical stirring, adding 2 parts of 1, 4-butanediol, and reacting at 75 ℃ for 3 hours; and (2) dispersing the reaction liquid in 792 parts of deionized water under high-speed stirring of 1500r/min, and stirring for 30 minutes to obtain the color waterborne polyurethane.

Example 3

The method comprises the following steps: preparing color polyester polyol, (1) weighing 120 parts of weighed adipic acid, 85 parts of neopentyl glycol, 20 parts of lake blue dye containing active hydroxyl and 0.3 part of tetrabutyl titanate into a four-neck flask, heating to 80 ℃, and uniformly stirring the materials in an ultrasonic dispersion and stirring manner; (2) gradually heating to 240 ℃ and reacting for 4 hours; (3) and (3) distilling water and residual monomers under reduced pressure, and detecting that the water content is less than 0.05 percent, the acid value is less than 1mgKOH/g and the hydroxyl value is 52-58mgKOH/g to obtain the color polyester polyol.

Step two: preparing color waterborne polyurethane, (1) dehydrating 210g of polytetrahydrofuran diol (the number average molecular weight is 2000), 100g of color polyester polyol obtained in the first step and 21 parts of dimethylolpropionic acid at 120 ℃ for 1 hour in vacuum, cooling to 40 ℃, adding 17 parts of triethylamine, stirring the raw materials to be uniform and transparent, adding 115g of toluene diisocyanate, reacting at 80 ℃ for 2 hours under mechanical stirring, adding 2g of 1, 6-hexanediol, and reacting at 75 ℃ for 3 hours; (2) and dispersing the reaction solution in 940 deionized water under high-speed stirring at 1500r/min, and stirring for 30 minutes to obtain the color waterborne polyurethane.

Comparative example 1

Comparative example 1 differs from example 1 by the following steps:

the method comprises the following steps: preparing polyester polyol, (1) weighing 100 parts of weighed adipic acid, 51 parts of ethylene glycol and 0.4 part of tetrabutyl titanate into a four-neck flask, heating to 80 ℃, and uniformly stirring the materials in an ultrasonic dispersion and stirring manner; (2) gradually heating to 240 ℃ and reacting for 4 hours; (3) decompressing to-0.09 Mpa to distill out water and residual monomer, detecting the water content is less than 0.05%, the acid value is less than 1mgKOH/g, the hydroxyl value is 52-58mgKOH/g, and obtaining the polyester polyol.

Step two: preparing color waterborne polyurethane (1), namely, dehydrating 300 parts of polytetrahydrofuran ether glycol (the number average molecular weight is 2000), 100 parts of polyester polyol obtained in the first step and 25 parts of dimethylolpropionic acid at 120 ℃ for 1 hour in vacuum, cooling to 50 ℃, adding 23 parts of triethylamine, stirring the raw materials until the raw materials are uniform and transparent, adding 92 parts of isophorone diisocyanate, reacting at 90 ℃ for 3 hours under mechanical stirring, adding 1.5 parts of neopentyl glycol, and reacting at 80 ℃ for 3 hours; (2) and (3) dispersing the reaction solution in 750 parts of deionized water under high-speed stirring of 1500r/min, stirring for 30 minutes, adding 10 parts of disperse yellow dye, and uniformly stirring to obtain the color waterborne polyurethane.

Comparative example 2

Comparative example 2 differs from example 2 in the following steps:

the method comprises the following steps: preparing polyester polyol, (1) weighing 60 parts of weighed adipic acid, 50 parts of sebacic acid, 71 parts of 1, 4-butanediol and 0.3 part of tetrabutyl titanate into a four-neck flask, heating to 80 ℃, and uniformly stirring the materials in an ultrasonic dispersion and stirring manner; (2) gradually heating to 240 ℃ and reacting for 4 hours; and (3) distilling water and residual monomers under reduced pressure, and detecting that the water content is less than 0.05 percent, the acid value is less than 1mgKOH/g and the hydroxyl value is 52-58mgKOH/g to obtain the polyester polyol.

Step two: preparing color waterborne polyurethane (1), namely, carrying out vacuum dehydration on 205 parts of polytetrahydrofuran diol (the number average molecular weight is 1000), 100 parts of polypropylene glycol (the number average molecular weight is 2000), 80 parts of polyester polyol obtained in the first step and 30 parts of dimethylolpropionic acid at 120 ℃ for 1 hour, cooling to 50 ℃, adding 27 parts of triethylamine, stirring the raw materials until the raw materials are uniform and transparent, adding 215 parts of dicyclohexylmethane diisocyanate, reacting at 90 ℃ for 2 hours under mechanical stirring, adding 2 parts of 1, 4-butanediol, and reacting at 75 ℃ for 3 hours; and (2) dispersing the reaction solution in 792 parts of deionized water under high-speed stirring of 1500r/min, stirring for 30 minutes, adding 13 parts of acid orange dye containing active hydroxyl, and uniformly stirring to obtain the colored waterborne polyurethane.

Comparative example 3

Comparative example 3 differs from example 3 in the following steps:

the method comprises the following steps: preparing polyester polyol, (1) weighing 120 parts of weighed adipic acid, 85 parts of neopentyl glycol and 0.3 part of tetrabutyl titanate into a four-neck flask, heating to 80 ℃, and uniformly stirring the materials in an ultrasonic dispersion and stirring manner; (2) gradually heating to 240 ℃ and reacting for 4 hours; (3) and (3) distilling water and residual monomers under reduced pressure, and detecting that the water content is less than 0.05 percent, the acid value is less than 1mgKOH/g and the hydroxyl value is 52-58mgKOH/g to obtain the polyester polyol.

Step two: preparing color waterborne polyurethane, (1) dehydrating 210 parts of polytetrahydrofuran diol (the number average molecular weight is 2000), 100 parts of polyester polyol obtained in the first step and 21 parts of dimethylolpropionic acid at 120 ℃ for 1 hour in vacuum, cooling to 40 ℃, adding 17 parts of triethylamine, stirring the raw materials until the raw materials are uniform and transparent, adding 115 parts of toluene diisocyanate, reacting for 2 hours at 80 ℃ under mechanical stirring, adding 2 parts of 1, 6-hexanediol, and reacting for 3 hours at 75 ℃; (2) and (3) dispersing the reaction solution in 940 parts of deionized water under high-speed stirring at 1500r/min, stirring for 30 minutes, then adding 20 parts of lake blue dye containing active hydroxyl, and uniformly stirring to obtain the colored waterborne polyurethane.

Comparative example 4

Comparative example 4 differs from example 3 by the following steps:

the method comprises the following steps: preparing polyester polyol, (1) weighing 120 parts of weighed adipic acid, 85 parts of neopentyl glycol and 0.3 part of tetrabutyl titanate into a four-neck flask, heating to 80 ℃, and uniformly stirring the materials in an ultrasonic dispersion and stirring manner; (2) gradually heating to 240 ℃ and reacting for 4 hours; (3) and (3) distilling water and residual monomers under reduced pressure, and detecting that the water content is less than 0.05 percent, the acid value is less than 1mgKOH/g and the hydroxyl value is 52-58mgKOH/g to obtain the polyester polyol.

Step two: preparing color waterborne polyurethane, (1) dehydrating 210 parts of polytetrahydrofuran diol (the number average molecular weight is 2000), 100 parts of polyester polyol obtained in the first step, 21 parts of dimethylolpropionic acid and 20 parts of lake blue dye containing active hydroxyl groups at 120 ℃ for 1 hour in vacuum, cooling to 40 ℃, adding 17 parts of triethylamine, stirring the raw materials until the raw materials are uniform and transparent, adding 115 parts of toluene diisocyanate, reacting at 80 ℃ for 2 hours under mechanical stirring, adding 2 parts of 1, 6-hexanediol, and reacting at 75 ℃ for 3 hours; (2) and (3) dispersing the reaction solution in 940 parts of deionized water under high-speed stirring of 1500r/min, and stirring for 30 minutes to obtain the color waterborne polyurethane.

On the premise of selecting the same raw materials, the prepared samples are used as examples 1-3 and comparative examples 1-4 for detection. Examples 1-3 and comparative examples 1-4 were applied to a microfiber impregnation process using a conventional microfiber leather process: firstly, soaking the color waterborne polyurethane in microfiber base cloth, and then testing after reducing and drying. Color migration resistance, dry and wet rubbing fastness and washing fastness test: according to GBT 3920-2008. And (3) stability testing: measuring 50 ml of the color aqueous polyurethane emulsion, carrying out centrifugal test under the test conditions of 15 minutes and 3000r/min, and observing color uniformity. The results are shown in table 1:

TABLE 1

As can be seen from the table above, through comparison of the test results of the examples and the comparative examples, the colored waterborne polyurethane produced by the invention has higher stability, and is obviously higher in color fastness to washing, rubbing and color migration resistance when applied to microfiber leather.

The above is only a preferred embodiment of the present invention, and it should be noted that the above preferred embodiment should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and these modifications and adaptations should be considered within the scope of the invention.