阅读说明：本技术 一种水性合成革用耐磨耐刮擦聚氨酯树脂及其制备方法 (Wear-resistant scratch-resistant polyurethane resin for water-based synthetic leather and preparation method thereof ) 是由 刘娅林 刘文峰 梁新新 耿俊玲 张留成 郭翠娟 高云峰 陈玉国 于 2021-01-04 设计创作，主要内容包括：一种水性合成革用耐磨耐刮擦聚氨酯树脂及其制备方法,包括如下重量份数的物质：聚合物二元醇160-240份,聚二异氰酸酯56-100份,羧酸型小分子二元醇7.2-13.2份,羟基型小分子二元醇6-10份,催化剂0.2-0.4份,丙酮80-140份,磺酸盐型二元醇7-12份,中和剂4.1-6.8份,去离子水550-820份,交联改性剂4-8份,润湿剂4-6份,流平剂4-6份。本发明全部采用清洁环保的水性材料组成,生产过程清洁环保,得到的超纤革没有任何异味,在沙发家居内饰和汽车内饰应用中具有明显优势,并能解决溶剂型处理技术产生的环境污染问题。(A wear-resistant scratch-resistant polyurethane resin for water-based synthetic leather and a preparation method thereof comprise the following substances in parts by weight: 240 parts of polymer glycol 160-100 parts, 56-100 parts of polyisocyanate, 7.2-13.2 parts of carboxylic acid type micromolecule glycol, 6-10 parts of hydroxyl type micromolecule glycol, 0.2-0.4 part of catalyst, 80-140 parts of acetone, 7-12 parts of sulfonate type glycol, 4.1-6.8 parts of neutralizing agent, 550-820 parts of deionized water, 4-8 parts of crosslinking modifier, 4-6 parts of wetting agent and 4-6 parts of flatting agent. The invention is completely made of clean and environment-friendly water-based materials, the production process is clean and environment-friendly, the obtained microfiber leather has no peculiar smell, has obvious advantages in sofa home decoration and automobile interior decoration application, and can solve the problem of environmental pollution caused by solvent treatment technology.)

1. The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is characterized by comprising the following components in parts by weight: the composition comprises the following substances in parts by weight:

240 parts of polymer glycol 160-100 parts, 56-100 parts of polyisocyanate, 7.2-13.2 parts of carboxylic acid type micromolecule glycol, 6-10 parts of hydroxyl type micromolecule glycol, 0.2-0.4 part of catalyst, 80-140 parts of acetone, 7-12 parts of sulfonate type glycol, 4.1-6.8 parts of neutralizing agent, 550-820 parts of deionized water, 4-8 parts of crosslinking modifier, 4-6 parts of wetting agent and 4-6 parts of flatting agent.

2. The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather according to claim 1, which is characterized in that:

the polymer dihydric alcohol is polytetrahydrofuran ether dihydric alcohol or polypropylene glycol ether dihydric alcohol, and is mixed with polycarbonate dihydric alcohol and polysiloxane dihydric alcohol for use;

the number average molecular weight of the polymer diol is 650-3000;

the polymer dihydric alcohol is polytetrahydrofuran ether dihydric alcohol or polypropylene glycol ether dihydric alcohol, and the proportion of the polycarbonate dihydric alcohol to the polysiloxane dihydric alcohol is as follows: 4-5:1-2: 0.1-0.5.

3. The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather according to claim 2, which is characterized in that:

the number average molecular weight of the polymer dihydric alcohol is 2000;

the polymer dihydric alcohol is polytetrahydrofuran ether dihydric alcohol or polypropylene glycol ether dihydric alcohol, and the proportion of the polycarbonate dihydric alcohol to the polysiloxane dihydric alcohol is as follows: 4.2:1.5: 0.2.

4. the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather according to claim 1, which is characterized in that:

the polyisocyanate is one or a mixture of any two of isophorone diisocyanate, toluene diisocyanate and 4, 4-dicyclohexyl methane diisocyanate which are mixed in any proportion;

the hydroxyl type micromolecular dihydric alcohol is one or a mixture of any two of ethylene glycol, diethylene glycol and neopentyl glycol in any proportion;

the catalyst is any one of stannous octoate and organic bismuthate;

the sulfonate dihydric alcohol is sodium diaminosulfonate;

the neutralizer is a mixture of sodium hydroxide and dimethylaminoethanol;

the crosslinking modifier is one or a mixture of any two of melamine, diethylenetriamine and thiophosphoric acid triphenyltriamine which are mixed in any proportion;

the wetting agent is polyether modified polysiloxane;

the leveling agent is polyether modified polysiloxane.

5. The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather according to claim 4, which is characterized in that: the catalyst is organic bismuthate.

6. The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather according to claim 5, which is characterized in that: the catalyst is bismuth neodecanoate.

7. The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather according to claim 1, which is characterized in that: the ratio of the sodium hydroxide to the dimethylaminoethanol is 1-5: 5-12.

8. The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather according to claim 7, which is characterized in that: the ratio of the sodium hydroxide to the dimethylaminoethanol is 1.5: 9.

9. The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather according to claim 1, which is characterized in that:

the wetting agent is digao 245;

the leveling agent is 440 dyhi.

10. A preparation method of wear-resistant scratch-resistant polyurethane resin for water-based synthetic leather is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: accurately weighing polymer dihydric alcohol, polydiisocyanate, carboxylic acid type micromolecule dihydric alcohol, hydroxyl type micromolecule dihydric alcohol, catalyst, acetone, sulfonate type dihydric alcohol, neutralizing agent, deionized water, crosslinking modifier, wetting agent and flatting agent according to the proportion;

step two: adding polymer dihydric alcohol into a reactor, and vacuumizing and dehydrating for 0.5h at the temperature of 110 ℃;

step three: cooling to 60 ℃, adding the polyisocyanate, heating to 75-90 ℃, and carrying out polymerization reaction for 2-3 h;

step four: cooling to 60-70 ℃, adding carboxylic acid type micromolecule dihydric alcohol, acetone and a catalyst, heating to 75-85 ℃, reacting for 1-1.5h, adding hydroxyl type micromolecule dihydric alcohol, and continuing to react for 1.5-2 h. Cooling to 60-75 ℃, dropwise adding sulfonate dihydric alcohol, and continuously reacting for 0.5-1 h;

step five: cooling to 50-55 deg.C, adding neutralizer, stirring, adding deionized water, and dispersing; adding a crosslinking modifier, and stirring and reacting for 0.5h at the stirring speed of 300 r/min;

step six: heating to 65-70 ℃, and removing acetone in vacuum to obtain polyurethane aqueous dispersion;

step seven: and (5) adding a wetting agent and a flatting agent into the polyurethane aqueous dispersion obtained in the step six, and uniformly dispersing to obtain the waterborne polyurethane resin.

Technical Field

The invention belongs to the field of leather spraying adhesives, and particularly relates to a wear-resistant scratch-resistant polyurethane resin for water-based synthetic leather and a preparation method thereof.

Background

At present, synthetic leather products are more and more popular, and natural leather with insufficient resources is largely replaced to manufacture cases, vamps, automobile interiors, furniture decorations and the like. With the improvement of living standards and the improvement of environmental protection requirements of people, synthetic leather products not only need excellent appearance and touch but also need to be non-toxic and pollution-free, which not only puts higher requirements on synthetic leather, but also puts higher requirements on resin for the synthetic leather. Most importantly, the most basic is to use the water-based resin instead of the solvent-based resin, and maintain the performance even better than that of the solvent-based resin.

The aqueous polyurethane resin takes water as a dispersion medium, has the advantages of no toxicity, environmental protection, safety and the like, is essentially indistinguishable from solvent type polyurethane resin, and is totally a final film formed by polyurethane, but forms of polyurethane molecules in the medium (water or solvent) are different. Because polyurethane molecules are hydrophobic in nature, only hydrophilic groups are introduced into molecular chains, the hydrophilic groups are forcibly dispersed in water through external force, hydrophobic chain segments in the molecules are gathered, the hydrophilic chain segments are distributed on the surfaces of polyurethane resin particles and are in a thermodynamic unstable state in nature, the molecular chains of solvent type polyurethane resin are dissolved in a solvent, the molecular chains stretch uniformly and are in a thermodynamic stable state, and the molecular structure and the particle state of the hydrophilic groups determine that the waterborne polyurethane resin has unique performances of good film forming performance, strong covering power, firm bonding, excellent physical performance of a coating and the like, so that the grade of the synthetic leather is greatly improved.

The traditional waterborne polyurethane resin has certain defects due to the structure, the flexibility of the formed film of the resin is not enough, and the wear resistance and scratch resistance are not enough, so that the application of the waterborne polyurethane resin in synthetic leather is restricted. The invention aims to provide a high-wear-resistance and scratch-resistant waterborne polyurethane resin and a preparation method thereof, so as to improve the performance grade of synthetic leather.

Disclosure of Invention

The invention provides a wear-resistant scratch-resistant polyurethane resin for water-based synthetic leather, which is used for overcoming the defects in the prior art.

The invention is realized by the following technical scheme:

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather comprises the following substances in parts by weight:

240 parts of polymer glycol 160-100 parts, 56-100 parts of polyisocyanate, 7.2-13.2 parts of carboxylic acid type micromolecule glycol, 6-10 parts of hydroxyl type micromolecule glycol, 0.2-0.4 part of catalyst, 80-140 parts of acetone, 7-12 parts of sulfonate type glycol, 4.1-6.8 parts of neutralizing agent, 550-820 parts of deionized water, 4-8 parts of crosslinking modifier, 4-6 parts of wetting agent and 4-6 parts of flatting agent.

The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is characterized in that the polymer dihydric alcohol is one of polytetrahydrofuran ether dihydric alcohol and polypropylene glycol ether dihydric alcohol, and is mixed with polycarbonate dihydric alcohol and polysiloxane dihydric alcohol for use;

the number average molecular weight of the polymer diol is 650-3000;

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather comprises the following polymer dihydric alcohol, wherein the polymer dihydric alcohol is polytetrahydrofuran ether dihydric alcohol or polypropylene glycol ether dihydric alcohol, and the ratio of the polymer dihydric alcohol to the polycarbonate dihydric alcohol to the polysiloxane dihydric alcohol is as follows: 4-5:1-2: 0.1-0.5.

The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather has the advantages that the number average molecular weight of the polymer diol is 2000;

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather comprises the following polymer dihydric alcohol, wherein the polymer dihydric alcohol is polytetrahydrofuran ether dihydric alcohol or polypropylene glycol ether dihydric alcohol, and the ratio of the polymer dihydric alcohol to the polycarbonate dihydric alcohol to the polysiloxane dihydric alcohol is as follows: 4.2:1.5: 0.2.

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is a mixture of one or two of isophorone diisocyanate (IPDI), Toluene Diisocyanate (TDI) and 4, 4-dicyclohexyl methane diisocyanate (H12MDI) mixed in any proportion;

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is a mixture of one or any two of ethylene glycol, diethylene glycol and neopentyl glycol in any proportion;

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is characterized in that the catalyst is any one of stannous octoate and organic bismuthate;

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is characterized in that the sulfonate diol is sodium diaminosulfonate;

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is prepared by mixing sodium hydroxide and dimethylaminoethanol as a neutralizer;

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is characterized in that the crosslinking modifier is one or a mixture of any two of melamine, diethylenetriamine and thiophosphoric acid triphenyltriamine which are mixed in any proportion;

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is characterized in that the wetting agent is polyether modified polysiloxane;

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is characterized in that the leveling agent is polyether modified polysiloxane.

The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is characterized in that the catalyst is organic bismuthate.

The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is characterized in that the catalyst is bismuth neodecanoate.

The ratio of the sodium hydroxide to the dimethylaminoethanol is 1-5: 5-12.

The ratio of the sodium hydroxide to the dimethylaminoethanol is 1.5: 9.

The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is characterized in that the wetting agent is 245 digao;

the wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is characterized in that the leveling agent is 440 digao.

A preparation method of wear-resistant scratch-resistant polyurethane resin for water-based synthetic leather comprises the following steps:

the method comprises the following steps: accurately weighing polymer dihydric alcohol, polydiisocyanate, carboxylic acid type micromolecule dihydric alcohol, hydroxyl type micromolecule dihydric alcohol, catalyst, acetone, sulfonate type dihydric alcohol, neutralizing agent, deionized water, crosslinking modifier, wetting agent and flatting agent according to the proportion;

step two: adding polymer dihydric alcohol into a reactor, and vacuumizing and dehydrating for 0.5h at the temperature of 110 ℃;

step three: cooling to 60 ℃, adding the polyisocyanate, heating to 75-90 ℃, and carrying out polymerization reaction for 2-3 h;

step four: cooling to 60-70 ℃, adding carboxylic acid type micromolecule dihydric alcohol, acetone and a catalyst, heating to 75-85 ℃, reacting for 1-1.5h, adding hydroxyl type micromolecule dihydric alcohol, and continuing to react for 1.5-2 h. Cooling to 60-75 ℃, dropwise adding sulfonate dihydric alcohol, and continuously reacting for 0.5-1 h;

step five: cooling to 50-55 deg.C, adding neutralizer, stirring, adding deionized water, and dispersing; adding a crosslinking modifier, and stirring and reacting for 0.5h at the stirring speed of 300 r/min;

step six: heating to 65-70 ℃, and removing acetone in vacuum to obtain polyurethane aqueous dispersion;

step seven: and (5) adding a wetting agent and a flatting agent into the polyurethane aqueous dispersion obtained in the step six, and uniformly dispersing to obtain the waterborne polyurethane resin.

The wear-resistant scratch-resistant polyurethane resin for the water-based synthetic leather is described.

The invention has the advantages that:

the super-fiber leather is completely made of clean and environment-friendly water-based materials, the production process is clean and environment-friendly, the obtained super-fiber leather has no peculiar smell, has obvious advantages in sofa home decoration and automobile interior decoration application, and can solve the problem of environmental pollution caused by a solvent type treatment technology.

The catalyst adopted by the invention is a bismuth sulfonic acid group catalyst, belongs to a new generation of nontoxic and environment-friendly catalyst, replaces the organotin-containing catalyst commonly used in the production of waterborne polyurethane emulsion at present, and the organotin heavy metal catalyst remained in the polyurethane emulsion can not only cause environmental pollution, but also cause organism malformation and chronic poisoning, and the catalyst is listed in a forbidden list by developed countries such as European Union. The organic bismuth catalyst not only belongs to a novel non-toxic and environment-friendly catalyst for synthesizing polyurethane materials, but also can ensure that the prepared polyurethane product has narrower molecular weight distribution and lower viscosity, and can reduce the side reaction of water and-NCO groups in aqueous polyurethane emulsion.

According to the invention, the polycarbonate diol is adopted, and the polysiloxane modified polyurethane resin is added, so that the water resistance, acid and alkali resistance and surface smoothness of the resin coating are improved, and the scratch resistance of the resin coating is improved.

The wear-resistant resin coating adopts polycarbonate diol, compared with common polyether diol, the wear-resistant performance is greatly improved, and triamine crosslinking modification is adopted, so that the molecular structure is subjected to net-shaped crosslinking, and the wear-resistant and scratch-resistant performance of the resin coating is improved.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

the method comprises the following steps: 118g of polytetrahydrofuran ether dihydric alcohol, 42g of polycarbonate dihydric alcohol, 5.6g of polysiloxane dihydric alcohol, 56g of toluene diisocyanate, 7.2g of dimethylolpropionic acid, 6g of ethylene glycol, 0.2g of catalyst, 100g of acetone, 8g of sodium diaminosulfonate, 0.6g of sodium hydroxide, 3.5g of dimethylethanolamine, 550g of deionized water, 4g of diethylenetriamine, 4g of wetting agent and 4.5g of flatting agent are accurately weighed

Step two: adding polytetrahydrofuran ether dihydric alcohol, polycarbonate dihydric alcohol and polysiloxane dihydric alcohol into a round-bottom flask provided with a stirrer, a condensing device and a temperature measuring device, and vacuumizing and dehydrating for 0.5 hour at 110 ℃.

Step three: cooling to 60 ℃, adding toluene diisocyanate, heating to 80 ℃, and carrying out polymerization reaction for 2 hours.

Step four: cooling to 70 ℃, adding dimethylolpropionic acid, acetone and bismuth neodecanoate, heating to 75 ℃, reacting for 1 hour, adding ethylene glycol, and continuing to react for 1.5 hours. Cooling to 60 ℃, dripping sodium diaminosulfonate, and continuing to react for 0.5 hour.

Step five: cooling to 50 deg.C, adding neutralizer, stirring, adding deionized water, and dispersing. Adding diethylenetriamine and stirring at low speed for half an hour.

Step six: heating to 65 ℃, and removing acetone in vacuum to obtain the polyurethane aqueous dispersion.

Step seven: and adding a wetting agent and a flatting agent into the aqueous dispersion, and uniformly dispersing to obtain the waterborne polyurethane resin.

Example 2:

the method comprises the following steps: 147g of polytetrahydrofuran ether dihydric alcohol, 52.5g of polycarbonate dihydric alcohol, 4.2g of polysiloxane dihydric alcohol, 100g of 4, 4-dicyclohexylmethane diisocyanate, 10.5g of dimethylolpropionic acid, 8.5g of diethylene glycol, 0.28g of catalyst, 80g of acetone, 9.2g of sodium diaminosulfonate, 0.85g of sodium hydroxide, 5.1g of dimethylethanolamine, 780g of deionized water, 8g of melamine, 5.6g of wetting agent and 6g of flatting agent are accurately weighed

Step two: adding polytetrahydrofuran ether dihydric alcohol, polycarbonate dihydric alcohol and polysiloxane dihydric alcohol into a round-bottom flask provided with a stirrer, a condensing device and a temperature measuring device, and vacuumizing and dehydrating for 0.5 hour at 110 ℃.

Step three: cooling to 60 ℃, adding 4, 4-dicyclohexyl methane diisocyanate, heating to 86 ℃, and carrying out polymerization reaction for 2.5 hours.

Step four: cooling to 60 ℃, adding dimethylolpropionic acid, acetone and bismuth neodecanoate, heating to 85 ℃, reacting for 1 hour, adding diethylene glycol, and continuing to react for 2 hours. Cooling to 75 ℃, dropwise adding sodium diaminosulfonate, and continuing to react for 1 hour.

Step five: cooling to 55 deg.C, adding neutralizer, stirring, adding deionized water, and dispersing. The melamine is added and stirred at low speed for half an hour.

Step six: heating to 70 ℃, and removing acetone in vacuum to obtain the polyurethane aqueous dispersion.

Step seven: and adding a wetting agent and a flatting agent into the aqueous dispersion, and uniformly dispersing to obtain the waterborne polyurethane resin.

Example 3:

the method comprises the following steps: 176.8g of polypropylene glycol ether diol, 63.2g of polycarbonate diol, 8.4g of polysiloxane diol, 92.4g of isophorone diisocyanate, 13.2g of dimethylolbutyric acid, 10g of diethylene glycol, 0.4g of catalyst, 140g of acetone, 10.5g of sodium diaminosulfonate, 1g of sodium hydroxide, 5.8g of dimethylethanolamine, 820g of deionized water, 6.5g of triphenyltriamine thiophosphate, 6g of wetting agent and 5.2g of flatting agent are accurately weighed

Step two: adding polypropylene glycol ether dihydric alcohol, polycarbonate dihydric alcohol and polysiloxane dihydric alcohol into a round-bottom flask provided with a stirrer, a condensing device and a temperature measuring device, and vacuumizing and dehydrating for 0.5 hour at 110 ℃.

Step three: cooling to 60 ℃, adding isophorone diisocyanate, heating to 90 ℃, and carrying out polymerization reaction for 3 hours.

Step four: cooling to 70 ℃, adding dimethylol butyric acid, acetone and bismuth neodecanoate, heating to 80 ℃, reacting for 1.5 hours, adding diethylene glycol, and continuing to react for 2 hours. Cooling to 70 ℃, dropwise adding sodium diaminosulfonate, and continuing to react for 1 hour.

Step five: cooling to 53 deg.C, adding neutralizer, stirring, adding deionized water, and dispersing. Adding the thiophosphoric acid triphenyl triamine and stirring at a low speed for half an hour.

Step six: heating to 70 ℃, and removing acetone in vacuum to obtain the polyurethane aqueous dispersion.

Step seven: and adding a wetting agent and a flatting agent into the aqueous dispersion, and uniformly dispersing to obtain the waterborne polyurethane resin.

Example 4:

the method comprises the following steps: accurately weighing 134.4g of polypropylene glycol ether diol, 48g of polycarbonate diol, 6.4g of polysiloxane diol, 66.2g of toluene diisocyanate, 8.95g of dimethylolbutyric acid, 10.4g of neopentyl glycol, 0.25g of catalyst, 95g of acetone, 12g of sodium diaminosulfonate, 0.65g of sodium hydroxide, 3.93g of dimethylethanolamine, 665g of deionized water, 4.6g of melamine, 4.75g of wetting agent and 4.5g of flatting agent

Step two: adding polypropylene glycol ether dihydric alcohol, polycarbonate dihydric alcohol and polysiloxane dihydric alcohol into a round-bottom flask provided with a stirrer, a condensing device and a temperature measuring device, and vacuumizing and dehydrating for 0.5 hour at 110 ℃.

Step three: cooling to 60 ℃, adding toluene diisocyanate, heating to 75 ℃, and carrying out polymerization reaction for 3 hours.

Step four: cooling to 65 ℃, adding dimethylolbutyric acid, acetone and bismuth neodecanoate, heating to 80 ℃, reacting for 1 hour, adding neopentyl glycol, and continuing to react for 2 hours. Cooling to 65 ℃, dripping sodium diaminosulfonate, and continuing the reaction for 1 hour.

Step five: cooling to 53 deg.C, adding neutralizer, stirring, adding deionized water, and dispersing. The melamine is added and stirred at low speed for half an hour.

Step six: heating to 63 ℃, and removing acetone in vacuum to obtain the polyurethane aqueous dispersion.

Step seven: and adding a wetting agent and a flatting agent into the aqueous dispersion, and uniformly dispersing to obtain the waterborne polyurethane resin.

Comparative example:

the method comprises the following steps: 184.4g of polypropylene glycol ether glycol, 66.2g of toluene diisocyanate, 8.95g of dimethylolbutyric acid, 10.4g of neopentyl glycol, 0.25g of catalyst, 95g of acetone, 12g of sodium diaminosulfonate, 0.65g of sodium hydroxide, 3.93g of dimethylethanolamine, 665g of deionized water, 4.75g of wetting agent and 4.5g of flatting agent are accurately weighed

Step two: adding polypropylene glycol ether diol into a round-bottom flask provided with a stirrer, a condensing device and a temperature measuring device, and vacuumizing and dehydrating for 0.5 hour at 110 ℃.

Step three: cooling to 60 ℃, adding toluene diisocyanate, heating to 75 ℃, and carrying out polymerization reaction for 3 hours.

Step four: cooling to 65 ℃, adding dimethylolbutyric acid, acetone and bismuth neodecanoate, heating to 80 ℃, reacting for 1 hour, adding neopentyl glycol, and continuing to react for 2 hours. Cooling to 65 ℃, dripping sodium diaminosulfonate, and continuing the reaction for 1 hour.

Step five: cooling to 53 deg.C, adding neutralizer, stirring, adding deionized water, and dispersing. Stirring at low speed for half an hour.

Step six: heating to 63 ℃, and removing acetone in vacuum to obtain the polyurethane aqueous dispersion.

Step seven: and adding a wetting agent and a flatting agent into the aqueous dispersion, and uniformly dispersing to obtain the waterborne polyurethane resin.

The aqueous polyurethane resins obtained in examples 1 to 4 and comparative example were formed into films, and the film was subjected to a performance test, and the results are shown in table one.

Watch 1

As can be seen from the comparative test results in Table I: the 24-hour water absorption of the adhesive films of examples 1-4 was greatly reduced compared to the comparative example; the tensile strength and the elongation at break are improved to different degrees;

the detection method adopted is as follows:

1. the method for testing the water absorption of the adhesive film comprises the following steps: the adhesive film was cut into 2cm by 2cm squares, the mass of the cut sample was measured (M1), immersed in distilled water at 25 ℃, taken out after 24 hours, the surface was quickly wiped with filter paper, the mass was immediately weighed (M2), and the water absorption was calculated according to the following formula.

Water absorption rate (M2-M1)/M1%

2. The mechanical property test is carried out according to the regulation of the national standard GB/T16421-1996 test method for small plastic tensile property samples.

3. And (3) wear resistance test: GB/T1768-79 'determination method for abrasion resistance of paint film' is adopted to detect the abrasion resistance of the surface of the adhesive film. The average value of the mass loss (weight loss method) of the sample after grinding at a prescribed number of grinding revolutions was measured using a Taber abrasion tester (GT-7012-T type, high-speed iron tester) using an H-type rubber wheel, a load of 500g, and a rotation speed of 60 rpm.

4. Scratch resistance test (nail scratch): the surface of the adhesive film was scratched with a fingernail 10 times back and forth, and the surface was visually observed to evaluate according to the following criteria.

A: the scratch resistance is high

B little trace remained after scratching, and the scratch resistance was slightly low, but there was no practical problem

And C, marks remain after scratching, the scratch resistance is low, and the scratch resistance is problematic in practical use.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.