阅读说明：本技术 一种皮革覆膜材料及其制备方法 (Leather coating material and preparation method thereof ) 是由 党文生 查春梅 江浩文 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种皮革覆膜材料及其制备方法。本发明的皮革覆膜材料包括A、B组分,A组分：亲水性异氰酸酯75-90％、柔性异氰酸酯8-18％、稀释剂2-7％；B组分：脂肪族羟基聚氨酯分散体30-50％、羟基丙烯酸分散体5-10％、聚酯聚氨酯分散体5-10％、二氧化钛0-5％、纳米二氧化硅分散液4-8％、纳米改性石蜡乳液1-5％、助剂3-5％、去离子水余量；A、B组分质量比1:(5-10)。本发明的皮革覆膜材料,涂层断裂伸长率好,涂膜强韧抗裂,脆性温度低,且抗擦伤性好、不易被划伤,抗污染性好,耐溶剂擦拭不会失光发粘,耐酸性清洗剂擦拭不变色不剥落,触感舒适温润,耐老化,大幅延长了皮革制品的使用寿命。(The invention discloses a leather coating material and a preparation method thereof. The leather coating material comprises A, B components, A component: 75-90% of hydrophilic isocyanate, 8-18% of flexible isocyanate and 2-7% of diluent; and B component: 30-50% of aliphatic hydroxyl polyurethane dispersoid, 5-10% of hydroxyl acrylic acid dispersoid, 5-10% of polyester polyurethane dispersoid, 0-5% of titanium dioxide, 4-8% of nano silicon dioxide dispersion liquid, 1-5% of nano modified paraffin emulsion, 3-5% of auxiliary agent and the balance of deionized water; A. the mass ratio of the component B is 1 (5-10). The leather coating material has the advantages of good elongation at break of the coating, toughness and crack resistance of the coating, low brittleness temperature, good scratch resistance, difficulty in scratching, good pollution resistance, solvent-resistant wiping, no light loss and stickiness, acid-resistant cleaning agent wiping, no discoloration and peeling, comfortable and mild touch, aging resistance and great prolongation of the service life of leather products.)

1. A leather film-coating material is characterized by comprising a component A and a component B which are calculated according to mass percentage,

the component A comprises the following components:

75-90% of hydrophilic isocyanate

8 to 18 percent of flexible isocyanate

2-7% of a diluent;

the component B comprises the following components:

wherein the mass ratio of the component A to the component B is 1 (5-10).

2. The leather coating material according to claim 1, wherein the hydrophilic isocyanate is a hydrophilic aliphatic polyisocyanate based on hexamethylene diisocyanate.

3. A leather coating material according to claim 1 or 2, wherein the flexible isocyanate is an aliphatic ester based prepolymer based on hexamethylene diisocyanate.

4. The leather film covering material according to any one of claims 1 to 3, wherein the polyester polyurethane dispersion is UH 240.

5. The leather film covering material according to any one of claims 1 to 4, wherein the modified paraffin emulsion is AQUACER 539.

6. The leather covering film material as claimed in any one of claims 1 to 5, wherein the auxiliary agent comprises the following components by mass percent of 3-5% of the auxiliary agent:

7. the leather coating material according to claim 6, wherein the dispersant is a polyether copolymer dispersant;

preferably, the defoamer is a polysiloxane defoamer;

preferably, the rheology agent is a polyurethane rheology agent;

preferably, the leveling agent is an acrylic copolymer leveling agent.

8. The leather coating material of any one of claims 1-7, wherein the diluent is a PGDA diluent.

9. A method of preparing the leather film covering material according to any one of claims 1 to 8, comprising the steps of:

1) preparation of component A: weighing hydrophilic isocyanate, flexible isocyanate and a diluent according to a ratio, and uniformly stirring and mixing to obtain the component A;

2) preparation of the component B:

weighing deionized water, titanium dioxide, aliphatic hydroxyl polyurethane dispersoid, hydroxyl acrylic acid dispersoid, polyester polyurethane dispersoid, nano silicon dioxide dispersion liquid, modified paraffin emulsion and auxiliary agent according to the proportion, and uniformly stirring and mixing to obtain the component B;

3) the component A and the component B are used in a matching way according to the mass ratio of 1 (5-10).

10. The method as claimed in claim 9, wherein in step 1), the stirring speed is 300-500rpm, and the stirring time is 20-40 min;

preferably, in the step 2), the specific preparation process of the component B is as follows:

a) weighing deionized water according to the proportion, sequentially adding a polyether copolymer dispersant and a polysiloxane antifoaming agent, and dispersing for 15-30min at the stirring speed of 600-;

b) sequentially adding titanium dioxide into the mixed material obtained in the step a) according to the proportion, and dispersing for 15-20min at the stirring speed of 1000-1400 rpm;

c) sequentially weighing the aliphatic hydroxyl polyurethane dispersoid, the hydroxyl acrylic acid dispersoid, the polyester polyurethane dispersoid, the nano silicon dioxide dispersion liquid and the modified paraffin emulsion according to the proportion, and stirring at the stirring speed of 400-600rpm for 10-15min to obtain a premixed resin dispersoid;

d) adding the premixed resin dispersion obtained in the step c) into the material obtained in the step b), and dispersing for 15-20min at the stirring speed of 700-900 rpm;

e) and d) sequentially adding a polyether copolymer dispersing agent, a polysiloxane defoaming agent, a polyurethane rheological agent and an acrylic copolymer flatting agent into the mixed material obtained in the step d), and dispersing at the stirring speed of 700-900rpm for 20-30min to obtain the component B.

Technical Field

The invention relates to the technical field of environment-friendly leather chemicals, and relates to a leather coating material and a preparation method thereof.

Background

At present, composite resin coating agent products for leather in leather chemicals have corresponding requirements on breaking elongation, tensile strength and brittleness temperature. However, the existing protective and decorative materials used as leather surfaces can not meet the actual use requirements, such as low scratch resistance of the surfaces, pollution resistance, solvent wiping resistance and household chemical resistance, which are not up to the actual requirements, i.e. the durability of the surface coatings is not enough. The improvement of the comprehensive performance of the leather surface finishing agent and the improvement of the durability of the coating are the following main research directions.

The leather film coating material is an environment-friendly water-based environment-friendly material, and can completely meet the actual requirements in the aspects of elongation at break and brittle temperature. Similarly, the technical requirements on the aspects of scratch-resistant hardness of the surface, pollution resistance, easy cleaning, wiping and cleaning by using a solvent-resistant cleaning agent and chemical corrosion damage resistance of the leather coating material are simultaneously provided, and if the performance indexes are excellent, the service life of the leather product can be greatly prolonged.

CN108192482A discloses a special polyurethane finishing agent for leather, which comprises the following raw materials in parts by weight: 50-100 parts of isocyanate-terminated polyurethane prepolymer, 5-20 parts of water-based acrylic resin, 2-5 parts of aminosilane coupling agent, 2-5 parts of nano titanium dioxide, 3-6 parts of perfluoroalkyl alcohol, 2-8 parts of N, N dihydroxyethyl 3 amino methyl propionate, 2-5 parts of triethylamine, 0.5-2.5 parts of hydroxyl-terminated polydimethylsiloxane, 5-15 parts of collagen, 3-6 parts of oxidized and sulfited fish oil, 2-5 parts of peanut oil, 40-70 parts of diluent, 1-4 parts of stearic acid, 0.8-2 parts of antibacterial agent and 2-6 parts of attapulgite. The special polyurethane finishing agent for leather provided by the invention has the advantages of stable performance, excellent antibacterial and mildew resistance and good waterproof performance. However, the properties of the coating agent in terms of scratch hardness of the surface, contamination resistance and easy cleanability, resistance to wiping with a solvent-based cleaner, and air permeability and aging resistance are desired to be further improved.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a leather coating material and a preparation method thereof, and the prepared leather coating material has the advantages of good coating elongation at break, high tensile strength, low brittleness temperature, capability of meeting the requirements of leather material prevention, good scratch resistance, difficulty in scratching, good pollution resistance, cleaning of stains once, solvent-resistant wiping, no light loss and stickiness, chemical corrosion damage resistance, atmospheric environment aging resistance, comfortable and warm touch feeling, and capability of greatly prolonging the service life of leather products.

One of the purposes of the invention is to provide a leather coating material, and in order to achieve the purpose, the invention adopts the following technical scheme:

a leather coating material comprises a component A and a component B, which are calculated according to mass percentage,

the component A comprises the following components:

75-90% of hydrophilic isocyanate

8 to 18 percent of flexible isocyanate

2-7% of a diluent;

the component B comprises the following components:

wherein the mass ratio of the component A to the component B is 1 (5-10).

In the leather coating material, the hydroxyl resin dispersoid with excellent selection performance of the component B ensures the main coating performances of elongation at break, tensile strength, scratch resistance, pollution resistance, solvent resistance, low temperature resistance and the like. The leather film coating material simultaneously has the physical and chemical mechanical properties of elongation at break, tensile strength, scratch resistance, pollution resistance, solvent resistance, low temperature resistance and the like, and particularly simultaneously has the comprehensive performance of integrating the properties of the elongation of more than 180 percent and the hardness of a surface scratch pencil of more than H.

In particular to a leather coating material which comprises a component A and a component B, and the components are calculated according to the mass percentage,

in the invention, the component A comprises the following components:

the hydrophilic isocyanate is 75 to 90% by mass, for example, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, or 90%.

The mass percentage of the flexible isocyanate is 8 to 18%, for example, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, or the like.

The diluent is 2 to 7% by mass, for example, 2%, 3%, 4%, 5%, 6%, 7%, or the like.

In the invention, the component B comprises the following components:

the aliphatic hydroxyl polyurethane dispersion may be 30 to 50% by mass, for example, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, or the like.

The mass percentage of the hydroxyacrylic acid dispersion is 5 to 10%, for example, 5%, 6%, 7%, 8%, 9%, or 10%.

The polyester polyurethane dispersion may be present in an amount of 5-10% by mass, for example 5%, 6%, 7%, 8%, 9% or 10% by mass.

The titanium dioxide is 0 to 5% by mass, for example, 0%, 1%, 2%, 3%, 4%, or 5%.

The nano-silica dispersion liquid is 4 to 8% by mass, for example, 4%, 5%, 6%, 7%, 8%, or the like.

The modified paraffin wax emulsion is 2 to 5 mass%, for example, 2%, 3%, 4%, or 5%.

The mass percent of the auxiliary agent is 3-5%, for example, 3%, 3.5%, 4%, 4.5%, or 5%.

The balance of water.

Wherein the mass ratio of the component A to the component B is 1 (5-10), such as 1:5, 1.6, 1:7, 1:8, 1:9 or 1: 10.

In the present invention, the hydrophilic isocyanate is a hydrophilic aliphatic polyisocyanate based on hexamethylene diisocyanate.

In the present invention, the flexible isocyanate is an aliphatic ester-based prepolymer based on hexamethylene diisocyanate.

In the present invention, the polyester polyurethane dispersion is UH 240.

In the invention, the nano modified paraffin emulsion is AQUACER 539.

The auxiliary agent comprises the following components in percentage by mass of 3-5 percent:

the dispersant is 0.5 to 0.9% by mass, for example, 0.5%, 0.6%, 0.7%, 0.8%, or 0.9%.

The defoaming agent is 0.2 to 0.6% by mass, for example, 0.2%, 0.3%, 0.4%, 0.5%, or 0.6%.

The mass percentage of the rheological agent is 2 to 3%, for example, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, or 3%.

The mass percent of the leveling agent is 0.1-0.5%, for example, 0.1%, 0.2%, 0.3%, 0.4%, or 0.5%.

The dispersant is a polyether copolymer dispersant.

Preferably, the defoamer is a silicone defoamer.

Preferably, the rheology agent is a polyurethane rheology agent.

Preferably, the leveling agent is an acrylic copolymer leveling agent.

The diluent is a PGDA diluent.

The invention also aims to provide a preparation method of the leather coating material, which comprises the following steps:

1) preparation of component A: weighing hydrophilic isocyanate, flexible isocyanate and a diluent according to a ratio, and uniformly stirring and mixing to obtain the component A;

2) preparation of the component B:

weighing deionized water, titanium dioxide, aliphatic hydroxyl polyurethane dispersoid, hydroxyl acrylic acid dispersoid, polyester polyurethane dispersoid, nano silicon dioxide dispersion liquid, modified paraffin emulsion and auxiliary agent according to the proportion, and uniformly stirring and mixing to obtain the component B;

3) the component A and the component B are used in a matching way according to the mass ratio of 1 (5-10).

In the step 1), the stirring speed is 300-500rpm, and the stirring time is 20-40 min.

Preferably, in the step 2), the specific preparation process of the component B is as follows:

a) weighing deionized water according to the proportion, sequentially adding a polyether copolymer dispersant and a polysiloxane antifoaming agent, and dispersing for 15-30min at the stirring speed of 600-;

b) sequentially adding titanium dioxide into the mixed material obtained in the step a) according to the proportion, and dispersing for 15-20min at the stirring speed of 1000-1400 rpm;

c) sequentially weighing the aliphatic hydroxyl polyurethane dispersoid, the hydroxyl acrylic acid dispersoid, the polyester polyurethane dispersoid, the nano silicon dioxide dispersion liquid and the modified paraffin emulsion according to the proportion, and stirring at the stirring speed of 400-600rpm for 10-15min to obtain a premixed resin dispersoid;

d) adding the premixed resin dispersion obtained in the step c) into the material obtained in the step b), and dispersing for 15-20min at the stirring speed of 700-900 rpm;

e) and d) sequentially adding a polyether copolymer dispersing agent, a polysiloxane defoaming agent, a polyurethane rheological agent and an acrylic copolymer flatting agent into the mixed material obtained in the step d), and dispersing at the stirring speed of 700-900rpm for 20-30min to obtain the component B.

Compared with the prior art, the invention has the beneficial effects that:

the leather coating material has good elongation at break of the coating, low brittleness temperature, good scratch resistance, good pollution resistance, no light loss and stickiness after cleaning stains, good air permeability, comfortable and mild touch feeling, weather aging resistance and difficult cracking and peeling, meets the necessary performance of a leather finishing agent, and greatly prolongs the service life of leather products. The invention achieves the purposes of environmental protection, high performance, durability and material saving, and belongs to high-performance environment-friendly leather chemicals in the field of new materials.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments.

Unless otherwise specified, various starting materials of the present invention are commercially available or prepared according to conventional methods in the art.

Example 1

The leather coating material comprises a component A and a component B, wherein the mass ratio of the component A to the component B is 1: 7.

Wherein, the component A comprises 86 percent of XP2547 hydrophilic isocyanate, 10 percent of E2863 flexible isocyanate and 4 percent of PGDA diluent by mass percentage.

The component B comprises 37% of U2757 aliphatic hydroxyl polyurethane dispersoid, 8% of A2770 hydroxyl acrylic acid dispersoid, 10% of UH240 polyester polyurethane dispersoid, 30.3% of deionized water, 4% of titanium dioxide, 4% of nano silicon dioxide dispersion liquid, 2% of AQUACER 539 modified paraffin emulsion, 0.8% of FX365 polyether copolymer dispersant, 0.4% of TEGO845 polysiloxane defoaming agent, 3% of HX6008 polyurethane rheological agent and 0.5% of BYK381 acrylic acid copolymer leveling agent in percentage by mass.

The preparation method of the leather coating material of the embodiment comprises the following steps:

1) preparation of component A: weighing isocyanate resin, isocyanate resin and PGDA (poly (propylene glycol) DA) diluent according to the proportion, stirring at 400rpm for 30min, and uniformly mixing to obtain a component A;

2) preparation of the component B:

a) weighing deionized water according to the proportion, sequentially adding a polyether copolymer dispersant and a polysiloxane defoamer, and dispersing at the stirring speed of 800rpm for 20min to obtain a mixed material;

b) sequentially adding titanium dioxide into the mixed material obtained in the step a) according to the mixture ratio, and dispersing for 20min at the stirring speed of 1200 rpm;

c) sequentially weighing the aliphatic hydroxyl polyurethane dispersoid, the hydroxyl acrylic acid dispersoid, the polyester polyurethane dispersoid, the nano silicon dioxide dispersoid and the nano modified paraffin emulsion according to the proportion, stirring for 10min at the stirring speed of 500rpm, slowly adding the epoxy resin dispersoid, and stirring for 12min at the stirring speed of 500rpm to obtain a premixed resin dispersoid;

d) adding the premixed resin dispersoid obtained in the step c) into the material obtained in the step b), and dispersing for 18min at the stirring speed of 800 rpm;

e) sequentially adding a polysiloxane antifoaming agent, a polyurethane rheological agent and an acrylic copolymer flatting agent into the mixed material obtained in the step d), and dispersing for 25min at a stirring speed of 800rpm to obtain a component B;

3) the component A and the component B are used in a matching way according to the mass ratio of 1: 7.

Example 2

The leather coating material comprises a component A and a component B, wherein the mass ratio of the component A to the component B is 1: 7.

Wherein, the component A comprises 75 percent of XP2547 hydrophilic isocyanate, 18 percent of E2863 flexible isocyanate and 7 percent of PGDA diluent by mass percentage.

Wherein, the component B comprises 30 percent of aliphatic hydroxyl polyurethane dispersoid, 10 percent of hydroxyl acrylic acid dispersoid, 8 percent of polyester polyurethane dispersoid, 30.1 percent of deionized water, 5 percent of titanium dioxide, 8 percent of nano silicon dioxide dispersoid, 5 percent of modified paraffin emulsion, 0.9 percent of polyether copolymer dispersant, 0.2 percent of polysiloxane defoamer, 2.5 percent of polyurethane rheological agent and 0.3 percent of acrylic copolymer leveling agent by mass percentage.

The preparation method of the leather coating material of the embodiment comprises the following steps:

1) preparation of component A: weighing XP2547 hydrophilic isocyanate, E2863 flexible isocyanate and PGDA diluent according to a ratio, stirring at 400rpm for 30min, and uniformly mixing to obtain a component A;

2) preparation of the component B:

a) weighing deionized water according to the proportion, sequentially adding a polyether copolymer dispersant and a polysiloxane defoamer, and dispersing at the stirring speed of 800rpm for 20min to obtain a mixed material;

b) sequentially adding titanium dioxide into the mixed material obtained in the step a) according to the mixture ratio, and dispersing for 20min at the stirring speed of 1200 rpm;

c) sequentially weighing the aliphatic hydroxyl polyurethane dispersoid, the hydroxyl acrylic acid dispersoid, the polyester polyurethane dispersoid, the nano silicon dioxide dispersoid and the nano modified paraffin emulsion according to the proportion, stirring for 10min at the stirring speed of 500rpm, slowly adding the epoxy resin dispersoid, and stirring for 12min at the stirring speed of 500rpm to obtain a premixed resin dispersoid;

d) adding the premixed resin dispersoid obtained in the step c) into the material obtained in the step b), and dispersing for 18min at the stirring speed of 800 rpm;

e) sequentially adding a polysiloxane antifoaming agent, a polyurethane rheological agent and an acrylic copolymer flatting agent into the mixed material obtained in the step d), and dispersing for 25min at a stirring speed of 800rpm to obtain a component B;

3) the component A and the component B are used in a matching way according to the mass ratio of 1: 7.

Example 3

The leather coating material comprises a component A and a component B, wherein the mass ratio of the component A to the component B is 1: 7.

Wherein, the component A consists of 90 percent of XP2547 hydrophilic isocyanate, 8 percent of E2863 flexible isocyanate and 2 percent of PGDA diluent by mass percentage.

The component B comprises, by mass, 44% of aliphatic hydroxyl polyurethane dispersoid, 7% of hydroxyl acrylic acid dispersoid, 7% of polyester polyurethane dispersoid, 27.7% of deionized water, 2% of titanium dioxide, 6% of nano silicon dioxide dispersion, 2% of modified paraffin emulsion, 0.7% of polyether copolymer dispersant, 0.5% of polysiloxane defoamer, 3% of polyurethane rheological agent and 0.1% of acrylic copolymer leveling agent.

The preparation method of the leather coating material of the embodiment comprises the following steps:

1) preparation of component A: weighing XP2547 hydrophilic isocyanate, E2863 flexible isocyanate and PGDA diluent according to a ratio, stirring at 400rpm for 30min, and uniformly mixing to obtain a component A;

2) preparation of the component B:

a) weighing deionized water according to the proportion, sequentially adding a polyether copolymer dispersant and a polysiloxane defoamer, and dispersing at the stirring speed of 800rpm for 20min to obtain a mixed material;

b) sequentially adding titanium dioxide into the mixed material obtained in the step a) according to the mixture ratio, and dispersing for 20min at the stirring speed of 1200 rpm;

c) sequentially weighing the aliphatic hydroxyl polyurethane dispersoid, the hydroxyl acrylic acid dispersoid, the polyester polyurethane dispersoid, the nano silicon dioxide dispersoid and the nano modified paraffin emulsion according to the proportion, stirring for 10min at the stirring speed of 500rpm, slowly adding the epoxy resin dispersoid, and stirring for 12min at the stirring speed of 500rpm to obtain a premixed resin dispersoid;

d) adding the premixed resin dispersoid obtained in the step c) into the material obtained in the step b), and dispersing for 18min at the stirring speed of 800 rpm;

e) sequentially adding a polysiloxane antifoaming agent, a polyurethane rheological agent and an acrylic copolymer flatting agent into the mixed material obtained in the step d), and dispersing for 25min at a stirring speed of 800rpm to obtain a component B;

3) the component A and the component B are used in a matching way according to the mass ratio of 1: 7.

Example 4

The leather coating material comprises a component A and a component B, wherein the mass ratio of the component A to the component B is 1: 7.

Wherein the component A XP2547 consists of 81 mass percent of hydrophilic isocyanate, 14 mass percent of E2863 flexible isocyanate and 5 mass percent of PGDA diluent.

Wherein, the component B comprises 50 percent of aliphatic hydroxyl polyurethane dispersoid, 5 percent of hydroxyl acrylic acid dispersoid, 5 percent of polyester polyurethane dispersoid, 30.7 percent of deionized water, 4 percent of nano silicon dioxide dispersion liquid, 2 percent of modified paraffin emulsion, 0.5 percent of polyether copolymer dispersant, 0.6 percent of polysiloxane defoamer, 2 percent of polyurethane rheological agent and 0.2 percent of acrylic copolymer leveling agent by mass percentage.

The preparation method of the leather coating material of the embodiment comprises the following steps:

1) preparation of component A: weighing XP2547 hydrophilic isocyanate, E2863 flexible isocyanate and PGDA diluent according to a ratio, stirring at 400rpm for 30min, and uniformly mixing to obtain a component A;

2) preparation of the component B:

a) weighing deionized water according to the proportion, sequentially adding a polyether copolymer dispersant and a polysiloxane defoamer, and dispersing at the stirring speed of 800rpm for 20min to obtain a mixed material;

b) sequentially weighing the aliphatic hydroxyl polyurethane dispersoid, the hydroxyl acrylic acid dispersoid, the polyester polyurethane dispersoid, the nano silicon dioxide dispersoid and the nano modified paraffin emulsion according to the proportion, stirring for 10min at the stirring speed of 500rpm, slowly adding the epoxy resin dispersoid, and stirring for 12min at the stirring speed of 500rpm to obtain a premixed resin dispersoid;

c) adding the premixed resin dispersoid obtained in the step b) into the material obtained in the step a), and dispersing for 18min at the stirring speed of 800 rpm;

d) sequentially adding a polysiloxane antifoaming agent, a polyurethane rheological agent and an acrylic copolymer flatting agent into the mixed material obtained in the step c), and dispersing for 25min at a stirring speed of 800rpm to obtain a component B;

3) the component A and the component B are used in a matching way according to the mass ratio of 1: 7.

Example 5

This example is different from example 1 in that the mass ratio of the A component to the B component is 1:5, and the others are the same as those of example 1.

Example 6

This example is different from example 1 in that the mass ratio of the A component to the B component is 1:10, and the others are the same as those of example 1.

Comparative example 1

This comparative example differs from example 1 in that the mass ratio of the A component to the B component was 1:2, and the others were the same as those of example 1.

Comparative example 2

This comparative example differs from example 1 in that the mass ratio of the A component to the B component was 1:15, and the others were the same as those of example 1.

Comparative example 3

This comparative example differs from example 1 in that the dispersion in component B is an aliphatic hydroxyl polyurethane dispersion only, and does not contain a hydroxyl acrylic dispersion, and a reduced amount of hydroxyl acrylic dispersion is added to the aliphatic hydroxyl polyurethane dispersion to ensure that the total amount is unchanged, all else being the same as in example 1.

Comparative example 4

This comparative example differs from example 1 in that the dispersion of component B is a hydroxyacrylic only dispersion, and no aliphatic hydroxyl polyurethane dispersion, and a reduced amount of aliphatic hydroxyl polyurethane dispersion was added to the hydroxyacrylic dispersion to ensure that the total amount was unchanged, all else being the same as in example 1.

Comparative example 5

This comparative example differs from example 1 in that component B, which does not contain a polyester polyurethane dispersion, the reduced polyester polyurethane dispersion is complemented with a hydroxyacrylic dispersion, and in the other components, which are identical to those of example 1, to ensure that the total amount is unchanged.

Comparative example 6

This comparative example differs from example 1 in that the B component, which did not contain the nanosilica dispersion, had a reduced nanosilica dispersion added on average to the other components to ensure the total amount was unchanged, all else being identical to example 1.

Comparative example 7

This comparative example differs from example 1 in that in component A, the isocyanate resin was only one XP2547 hydrophilic isocyanate, the rest being the same as in example 1.

Comparative example 8

This comparative example differs from example 1 in that the isocyanate resin in component A is only one E2863 flexible isocyanate, and the rest is the same as example 1.

The leather coating materials obtained in examples 1 to 6 were subjected to performance tests with the materials obtained in comparative examples 1 to 8, and the test results are shown in Table 1.

Wherein the test standards of pencil hardness, tensile strength, elongation at break and brittleness temperature of the coating film refer to QB/T5311-2018, the test standard of pollution resistance refers to GB/T9780-.

TABLE 1

As can be seen from Table 1, the overall performance of examples 1-6 is best. The leather coating material is an environment-friendly coating material, has the advantages of good elongation at break of a coating film, flexibility, comfort, high toughness, mild touch, low brittleness temperature and good consistency with leather, solves the requirement on durability of a coating layer on the surface of the leather, has good scratch resistance, good pollution resistance, cleaning of stains once, solvent wiping resistance, no stickiness, no light loss, acid resistance, cleaning corrosion resistance and no color change.

In comparative example 1, the mass ratio of the component A to the component B was too large, the coating was not completely cured, and the overall properties were completely lost.

In comparative example 2, the mass ratio of the component A to the component B was too small, the coating was not completely cured, and the overall properties were completely lost.

In comparative example 3, the dispersion of component B was only an aliphatic hydroxyl polyurethane dispersion, and no hydroxyl acrylic dispersion, which resulted in a decrease in pencil hardness, and a decrease in stain resistance and solvent resistance of the coating film.

In comparative example 4, the dispersion of component B was only a hydroxyacrylic dispersion and did not contain an aliphatic hydroxyl polyurethane dispersion, which resulted in a significant decrease in elongation, an increase in material brittleness temperature, and an increase in material brittleness.

In comparative example 5, the elongation was greatly reduced, the material brittleness temperature was increased, and the material brittleness was increased without the polyester polyurethane dispersion in the component B.

In comparative example 6, the absence of the nanosilica dispersion in component B significantly reduced the tensile strength of the coating film.

In comparative example 7, the isocyanate resin was only a hydrophilic isocyanate, the elongation of the coating film was greatly reduced, and the brittle temperature was significantly increased.

In comparative example 8, the isocyanate resin was only a flexible isocyanate, and A, B component had poor compatibility and failed to form a film normally.

The present invention is illustrated by the above-mentioned examples, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, i.e. it is not meant to imply that the present invention must rely on the above-mentioned detailed process equipment and process flow to be practiced. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.