CN106987203A - A kind of highlighted UV gloss oil of solvent-free leather and preparation technology - Google Patents

Abstract

This invention relates to a solvent-free high-gloss UV varnish for leather. The UV varnish comprises, by weight, 70-80 parts of difunctional aliphatic polyurethane acrylate, 5-15 parts of modified epoxy acrylate, 10-15 parts of monofunctional and difunctional monomers, 1-5 parts of photoinitiator, and 0.5-1.5 parts of additives. The solvent-free high-gloss UV varnish for leather of this invention features rapid curing (drying time less than 1 minute), significantly reduces the likelihood of dust adhesion to the wet film leading to reduced gloss, and provides excellent gloss and aesthetics.

Description

A kind of solvent-free leather highlight UV varnish and its preparation process

technical field

The invention relates to the technical field of fine chemicals, in particular to a solvent-free leather highlight UV varnish and a preparation process, which is suitable for surface treatment of leather and shoe materials.

Background technique

Whether it is synthetic leather, artificial leather or real leather, in order to obtain different surface gloss and feel, it must be surface-finished, that is, high-gloss finishing or mirror finishing. Surface finishing is an important and fashionable treatment of leather.

At present, its leather varnish is mainly acrylic emulsion or water-based polyurethane dispersion, which has a long drying time, weak adhesion, and gloss fullness that cannot meet the requirements of high-gloss or mirror finish; another widely used The mirror coating agent used is solvent-based moisture-curing polyurethane. The adhesive layer after moisture-curing polyurethane has a polyurethane-polyurea structure. This special chemical structure determines that it has excellent folding resistance, abrasion resistance, elasticity, and adhesion. Strength, durability, cold resistance, smoothness and brightness and other characteristics. However, such products use a large amount of organic solvents, and the complete curing speed of the product is relatively slow, and subsequent processes such as embossing and high-frequency pressing can only be carried out after 24 hours.

Curing varnish has the advantages of no volatile solvent, fast curing speed, high production efficiency, no pollution and energy saving. It is a good environmental protection replacement product. Although the existing UV products have high coating gloss and good fullness, most of them are too brittle and hard and not flexible enough to be used on leather. The flexibility and gloss of the coating film required by leather are contradictory. The gloss is average, but the flexibility is good, but it is easy to stick; the gloss is high, the flexibility decreases, and the coating film is dry. Therefore, the use of UV curing materials to make leather varnishes, and UV curing for finishing has not been reported so far.

Contents of the invention

In order to overcome the shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a solvent-free leather highlighting UV varnish with high flexibility and good flexibility.

Another object of the present invention is to provide a method for preparing the above-mentioned solvent-free leather highlighting UV varnish, including a method for synthesizing difunctional aliphatic urethane acrylate and epoxy acrylate.

The purpose of the present invention is to realize through the following technical solutions:

A solvent-free leather highlight UV varnish, characterized in that, the UV varnish comprises 70-80 parts by weight of difunctional aliphatic urethane acrylate, 5-15 parts of modified epoxy acrylate, 10-15 parts of mono- and di-functional monomers, 1-5 parts of photoinitiators, and 0.5-1.5 parts of additives. The developed solvent-free leather high-gloss UV varnish is solvent-free, VOC-free, high-efficiency and low-energy consumption. Its gloss can reach more than 92 degrees (60-degree angle), and its flexion can reach more than 100,000 times, which can meet the requirements of real leather and artificial leather. finishing requirements.

The difunctional aliphatic urethane acrylate comprises 15-45 parts by weight of polyol, 10-45 parts of diisocyanate, 0.2-2 part of organic bismuth catalyst, 0.1-1 part of paraoxyphenol as polymerization inhibitor and 15-30 parts of hydroxyethyl acrylate are prepared by the following method:

Add the formulated amount of polyol into the reaction kettle, heat up to 110-120°C, and vacuum dehydrate for 1-2 hours;

Then cool down to 40-50°C, while stirring, add diisocyanate dropwise, stir evenly, then raise the temperature to 70-80°C, and react for 2-3h;

Add 0.1-1 part of organic bismuth catalyst, react for 0.5-1h, cool down to 50-60°C, vacuumize and defoam until the content of isocyanate groups reaches 2-15%;

Add the polymerization inhibitor p-oxyphenol and the rest of the organic bismuth catalyst, mix evenly and add the formulated amount of hydroxyethyl acrylate dropwise until the content of isocyanate group is less than 0.5%, then stop the reaction, drop to normal temperature and discharge. The difunctional aliphatic urethane acrylate prepared by this method is composed of a variety of polyols and diisocyanates polymerized, and then capped with hydroxyethyl acrylate (HEA), which can meet the extremely high flexibility requirements of leather varnish.

In a preferred embodiment, the polyol is any one of a polyether polyol with a molecular weight between 200-1000, a polyester polyol or a polycarbonate diol with a molecular weight between 400-1000; The said diisocyanate is any one of isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), and hexamethylene-1,6-diisocyanate (HDI).

In a preferred embodiment, the modified epoxy acrylate includes 10-50 parts by weight of polypropylene glycol, 10-40 parts of anhydride, 0.2-2 parts of organic bismuth, 10-50 parts of E51 epoxy resin, 0.1-1 part of p-oxyphenol and 5-20 parts of acrylic acid are prepared according to the following method:

Add the formula amount of polypropylene glycol, acid anhydride and 0.1-1% organic bismuth into the reaction kettle, and raise the temperature to 70-80°C under the protection of nitrogen, and react for 2-3 hours;

Add the amount of E51 epoxy resin and the remaining organic bismuth, and heat up to 80-90°C to continue the reaction;

Add the formulated amount of p-oxyphenol and acrylic acid, raise the temperature to 90-95°C for reaction, stop the reaction when the acid value of the system is less than 5mgKOH/g, lower to normal temperature and discharge. The modified epoxy acrylate is produced from polyols and acid anhydrides. It has good flexibility as an ester intermediate. After adding epoxy, acrylic acid is used to introduce double bonds. It has the high gloss and excellent flexibility of epoxy. Monomer and other raw materials can be used to produce high gloss UV varnish for leather.

In a preferred embodiment, the monomers include the following components in parts by weight:

Diethoxy-1,6-hexanediol diacrylate 1-5;

2-Ethoxy-phenol acrylate 1-5;

Acrylamidomorpholine 1-5

Lauric Acrylate 4-8.

In a preferred embodiment, the photoinitiator comprises the following components in parts by weight:

2-Hydroxy-2-methyl-1-phenyl-1-propanone 1.0-3.0;

1-Hydroxy-cyclohexyl benzophenone 0.3-1.0;

2,4,6-Trimethylbenzoyl-diphenylphosphine oxide 0.2-1.0.

In a preferred embodiment, the auxiliary agent includes the following components in parts by weight:

Leveling agent 0.5-1.0;

Deaerator 0.3-0.5.

A preparation process for solvent-free leather highlighting UV varnish, comprising the following steps:

a. Weigh the bifunctional aliphatic urethane acrylate, modified epoxy acrylate, mono- and difunctional monomers, photoinitiators and auxiliary agents according to the formula quantity, add them in sequence and mix and stir at room temperature, get mixed solution;

b. Stir until the mixed solution is clear and transparent without suspended solids to prepare the solvent-free leather highlighting UV varnish.

In a preferred embodiment, the stirring time is not less than 50 minutes, and the stirring speed is in the range of 500-800 rpm.

Application of the above-mentioned solvent-free leather highlight UV varnish in leather coating.

The beneficial effects of the present invention are:

Compared with traditional leather finishing agents, the present invention has the advantages of curing leather UV varnish in that:

1. The curing speed is greatly improved, and the drying time is even less than 1min. The possibility of the wet film sticking to dust and causing the gloss to decrease is greatly reduced; the gloss and aesthetics of the coating film are excellent;

2. The volatilization of solvent is greatly reduced, no solvent residue, no peculiar smell;

3. It avoids the use of formaldehyde and other cross-linking agents in leather finishing agents, plays an environmental role and conforms to the development direction of ecological leather;

4. It can be used for leather finishing, as well as for artificial leather and synthetic leather. The equipment requirements are simple, and there is no need to redesign the production line. It only needs to install light curing equipment on the traditional production line;

5. The curing temperature is low, no baking is required, and the energy consumption is small (if the current popular LED light source is used, the energy consumption will be further reduced); the production efficiency of the present invention is high, and the subsequent process can be carried out directly after the coating film is dried, and it does not need to be left overnight. The product is a brand-new replacement product, which fully meets the current strong demand of the leather industry for environment, efficiency and space.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. example. Accordingly, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the claimed invention but represents only selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention. The present invention will be further described below with reference to specific examples.

Example 1

A solvent-free leather highlighting UV varnish, comprising the following components in parts by weight:

70 parts of difunctional aliphatic urethane acrylate;

10 parts of modified epoxy acrylate;

14 parts of monomer;

5 parts of photoinitiator;

Auxiliary 1 part.

Wherein said difunctional aliphatic urethane acrylate comprises 15 parts by weight of polyol, 10 parts of diisocyanate, 0.2 part of catalyst organic bismuth, 0.1 part of inhibitor p-oxyphenol and 15 parts of acrylic acid Hydroxyethyl esters are prepared as follows:

Add the formula amount of polyether polyol N-204 (Tianjin Petrochemical Group Co., Ltd.) into the reaction kettle equipped with stirrer, thermometer, condenser (reflux), and constant pressure dripping equipment, heat up to 110°C, and vacuumize Dehydration 2h;

Then lower the temperature to 45°C, and while stirring, drop in the formulated amount of isophorone diisocyanate IPDI, stir evenly, then raise the temperature to 75°C, and react for 3 hours;

Add 0.1 part of organic bismuth catalyst, react for 1 hour, cool down to 50°C, vacuumize and defoam until the content of isocyanate group (—NCO) reaches 2%;

Add the formulated amount of polymerization inhibitor p-oxyphenol and the rest of the organic bismuth catalyst, mix evenly and then add the formulated amount of hydroxyethyl acrylate (HEA) dropwise until the content of isocyanate group (-NCO) is less than 0.5%, then stop the reaction , down to normal temperature and discharged.

The obtained difunctional aliphatic urethane acrylate index is as follows:

Viscosity: 10,000±3000 (cps@60°C); color less than 200Apha color number; specific gravity: 1.10±0.05 (g/cm ³ @25°C; elongation: 310%; shrinkage: 10, functional base (Theoretical value): 2. Highly flexible urethane acrylate, high elongation, high gloss, good adhesion and surface dryness, low shrinkage, and excellent comprehensive performance.

Wherein the modified epoxy acrylate comprises 10 parts by weight of polypropylene glycol, 10 parts of acid anhydride, 0.2 part of organic bismuth, 10 parts of E51 epoxy resin, 0.1 part of paraoxyphenol and 5 parts of acrylic acid Prepared by the following method:

Add polypropylene glycol (PPG400), acid anhydride and 0.1 part of organic bismuth of formula quantity in the reaction still equipped with stirrer, thermometer, condenser (reflux), nitrogen pipe and constant pressure dripping equipment, under nitrogen protection, Raise the temperature to 80°C and react for 3 hours;

Add the formula amount of E51 epoxy resin (Kunshan Nanya epoxy resin) and the balance of organic bismuth, and heat up to 85°C to continue the reaction;

Add the formulated amount of p-oxyphenol and dropwise added the formulated amount of acrylic acid, raise the temperature to 95°C to react, when the acid value of the system is less than 5mgKOH/g, stop the reaction, lower to normal temperature and discharge.

The indicators of the prepared modified epoxy acrylate are as follows: light yellow liquid at 25°C, viscosity: 200,000-350,000 (cps@25°C), acid value: no more than 5.0 (mgKOH/g) , Chromatic number: no more than 2 (Gardner), functional base (theoretical value) is 2. It does not contain diluting monomers. Compared with general bisphenol A acrylate oligomers, it provides extremely high gloss, excellent toughness, and also has excellent curing speed and low shrinkage.

Wherein the monomer (monofunctional or difunctional) includes by weight parts:

5 parts of diethoxy 1,6 hexanediol diacrylate;

2 parts of 2-ethoxy-phenol acrylate;

2 parts of acrylamide morpholine;

Lauric acid acrylate 7 parts.

Wherein the photoinitiator includes 3 parts of 2-hydroxyl-2-methyl-1-phenyl-1-propanone (photoinitiator 1173), 0.3 part of 1-hydroxycyclohexyl benzophenone (photoinitiator Agent 184), 0.2 parts of (photoinitiator TPO).

The additives include 0.5g leveling agent (Tego Glide) and 0.5g defoamer (Tego2100) in parts by weight.

The product performance index of the solvent-free leather highlight UV varnish of this embodiment is shown in Table 1 below.

Example 2

A solvent-free leather highlighting UV varnish, comprising the following components in parts by weight:

70 parts of difunctional aliphatic urethane acrylate;

10 parts of modified epoxy acrylate;

14 parts of monomer;

5 parts of photoinitiator;

Auxiliary 1 part.

Wherein said difunctional aliphatic urethane acrylate comprises 25 parts by weight of polyol, 20 parts of diisocyanate, 0.6 part of catalyst organic bismuth, 0.3 part of polymerization inhibitor paraoxyphenol and 20 parts of acrylic acid Hydroxyethyl esters are prepared as follows:

Add the formula amount of polyether polyol N-204 (Tianjin Petrochemical Group Co., Ltd.) into the reaction kettle equipped with stirrer, thermometer, condenser (reflux), and constant pressure dripping equipment, heat up to 110°C, and vacuumize Dehydration 2h;

Then lower the temperature to 45°C, and while stirring, drop in the formulated amount of isophorone diisocyanate IPDI, stir evenly, then raise the temperature to 75°C, and react for 3 hours;

Add 0.1 part of organic bismuth catalyst, react for 1 hour, cool down to 50°C, vacuumize and defoam until the content of isocyanate group (—NCO) reaches 2%;

Add the formulated amount of polymerization inhibitor p-oxyphenol and the rest of the organic bismuth catalyst, mix evenly and then add the formulated amount of hydroxyethyl acrylate (HEA) dropwise until the content of isocyanate group (-NCO) is less than 0.5%, then stop the reaction , down to normal temperature and discharged.

The obtained difunctional aliphatic urethane acrylate index is as follows:

Viscosity: 10,000±3000 (cps@60°C); color less than 200Apha color number; specific gravity: 1.10±0.05 (g/cm ³ @25°C; elongation: 310%; shrinkage: 10, functional base (Theoretical value): 2. Highly flexible urethane acrylate, high elongation, high gloss, good adhesion and surface dryness, low shrinkage, and excellent comprehensive performance.

Wherein the modified epoxy acrylate comprises 25 parts by weight of polypropylene glycol, 20 parts of acid anhydride, 0.6 part of organic bismuth, 25 parts of E51 epoxy resin, 0.3 part of paraoxyphenol and 10 parts of acrylic acid Prepared by the following method:

Add polypropylene glycol (PPG400), acid anhydride and 0.3 part of organic bismuth of recipe amount in the reaction still equipped with stirrer, thermometer, condenser (reflux), nitrogen pipe and constant pressure dripping equipment, under nitrogen protection, Raise the temperature to 80°C and react for 3 hours;

Add the formula amount of E51 epoxy resin (Kunshan Nanya epoxy resin) and the balance of organic bismuth, and heat up to 85°C to continue the reaction;

Add the formulated amount of p-oxyphenol and dropwise added the formulated amount of acrylic acid, raise the temperature to 95°C to react, when the acid value of the system is less than 5mgKOH/g, stop the reaction, lower to normal temperature and discharge.

The indicators of the prepared modified epoxy acrylate are as follows: light yellow liquid at 25°C, viscosity: 200,000-350,000 (cps@25°C), acid value: no more than 5.0 (mgKOH/g) , Chromatic number: no more than 2 (Gardner), functional base (theoretical value) is 2. It does not contain diluting monomers. Compared with general bisphenol A acrylate oligomers, it provides extremely high gloss, excellent toughness, and also has excellent curing speed and low shrinkage.

Wherein the monomer (monofunctional or difunctional) includes by weight parts:

5 parts of diethoxy 1,6 hexanediol diacrylate;

2 parts of 2-ethoxy-phenol acrylate;

2 parts of acrylamide morpholine;

Lauric acid acrylate 7 parts.

Wherein the photoinitiator includes 3 parts of 2-hydroxyl-2-methyl-1-phenyl-1-propanone (photoinitiator 1173), 0.3 part of 1-hydroxycyclohexyl benzophenone (photoinitiator Agent 184), 0.2 parts of (photoinitiator TPO).

The additives include 0.5g leveling agent (Tego Glide) and 0.5g defoamer (Tego2100) in parts by weight.

The product performance index of the solvent-free leather highlight UV varnish of this embodiment is shown in Table 1 below.

Example 3

A solvent-free leather highlighting UV varnish, comprising the following components in parts by weight:

70 parts of difunctional aliphatic urethane acrylate;

10 parts of modified epoxy acrylate;

14 parts of monomer;

5 parts of photoinitiator;

Auxiliary 1 part.

Wherein said difunctional aliphatic urethane acrylate comprises 35 parts by weight of polyols, 30 parts of diisocyanate, 1.4 parts of catalyst organic bismuth, 0.7 parts of polymerization inhibitor paraoxyphenol and 25 parts of acrylic acid Hydroxyethyl esters are prepared as follows:

Add the formula amount of polyether polyol N-204 (Tianjin Petrochemical Group Co., Ltd.) into the reaction kettle equipped with stirrer, thermometer, condenser (reflux), and constant pressure dripping equipment, heat up to 110°C, and vacuumize Dehydration 2h;

Then lower the temperature to 45°C, while stirring, drop in the formulated amount of isophorone diisocyanate IPDI, stir evenly, then raise the temperature to 75°C, and react for 3 hours;

Add 0.1 part of organic bismuth catalyst, react for 1 hour, cool down to 50°C, vacuumize and defoam until the content of isocyanate group (—NCO) reaches 2%;

Add the formulated amount of polymerization inhibitor p-oxyphenol and the rest of the organic bismuth catalyst, mix evenly and then add the formulated amount of hydroxyethyl acrylate (HEA) dropwise until the content of isocyanate group (-NCO) is less than 0.5%, then stop the reaction , down to normal temperature and discharged.

The obtained difunctional aliphatic urethane acrylate index is as follows:

Viscosity: 10,000±3000 (cps@60°C); color less than 200Apha color number; specific gravity: 1.10±0.05 (g/cm ³ @25°C; elongation: 310%; shrinkage: 10, functional base (Theoretical value): 2. Highly flexible urethane acrylate, high elongation, high gloss, good adhesion and surface dryness, low shrinkage, and excellent comprehensive performance.

Wherein the modified epoxy acrylate comprises 40 parts by weight of polypropylene glycol, 30 parts of anhydrides, 1.4 parts of organic bismuth, 40 parts of E51 epoxy resin, 0.7 parts of paraoxyphenol and 15 parts of acrylic acid Prepared by the following method:

Add polypropylene glycol (PPG400), acid anhydride and 0.7 part of organic bismuth of recipe amount in the reactor that agitator, thermometer, condenser (reflux), nitrogen pipe and constant pressure dripping equipment are housed, under nitrogen protection, Raise the temperature to 80°C and react for 3 hours;

Add the formula amount of E51 epoxy resin (Kunshan Nanya epoxy resin) and the balance of organic bismuth, and heat up to 85°C to continue the reaction;

Add the formulated amount of p-oxyphenol and dropwise added the formulated amount of acrylic acid, raise the temperature to 95°C to react, when the acid value of the system is less than 5mgKOH/g, stop the reaction, lower to normal temperature and discharge.

The indicators of the prepared modified epoxy acrylate are as follows: light yellow liquid at 25°C, viscosity: 200,000-350,000 (cps@25°C), acid value: no more than 5.0 (mgKOH/g) , Chromatic number: no more than 2 (Gardner), functional base (theoretical value) is 2. It does not contain diluting monomers. Compared with general bisphenol A acrylate oligomers, it provides extremely high gloss, excellent toughness, and also has excellent curing speed and low shrinkage.

Wherein the monomer (monofunctional or difunctional) includes by weight parts:

5 parts of diethoxy 1,6 hexanediol diacrylate;

2 parts of 2-ethoxy-phenol acrylate;

2 parts of acrylamide morpholine;

Lauric acid acrylate 7 parts.

Wherein the photoinitiator includes 3 parts of 2-hydroxyl-2-methyl-1-phenyl-1-propanone (photoinitiator 1173), 0.3 part of 1-hydroxycyclohexyl benzophenone (photoinitiator Agent 184), 0.2 parts of (photoinitiator TPO).

The additives include 0.5g leveling agent (Tego Glide) and 0.5g defoamer (Tego2100) in parts by weight.

The product performance index of the solvent-free leather highlight UV varnish of this embodiment is shown in Table 1 below.

Example 4

A solvent-free leather highlighting UV varnish, comprising the following components in parts by weight:

70 parts of difunctional aliphatic urethane acrylate;

10 parts of modified epoxy acrylate;

14 parts of monomer;

5 parts of photoinitiator;

Auxiliary 1 part.

Wherein said difunctional aliphatic urethane acrylate comprises 45 parts by weight of polyol, 45 parts of diisocyanate, 2 parts of catalyst organic bismuth, 1 part of polymerization inhibitor paraoxyphenol and 30 parts of acrylic acid Hydroxyethyl esters are prepared as follows:

Add the formula amount of polyether polyol N-204 (Tianjin Petrochemical Group Co., Ltd.) into the reaction kettle equipped with stirrer, thermometer, condenser (reflux), and constant pressure dripping equipment, heat up to 110°C, and vacuumize Dehydration 2h;

Then lower the temperature to 45°C, and while stirring, drop in the formulated amount of isophorone diisocyanate IPDI, stir evenly, then raise the temperature to 75°C, and react for 3 hours;

Add 0.1 part of organic bismuth catalyst, react for 1 hour, cool down to 50°C, vacuumize and defoam until the content of isocyanate group (—NCO) reaches 2%;

Add the formulated amount of polymerization inhibitor p-oxyphenol and the rest of the organic bismuth catalyst, mix evenly and then add the formulated amount of hydroxyethyl acrylate (HEA) dropwise until the content of isocyanate group (-NCO) is less than 0.5%, then stop the reaction , down to normal temperature and discharged.

The obtained difunctional aliphatic urethane acrylate index is as follows:

Viscosity: 10,000±3000 (cps@60°C); color less than 200Apha color number; specific gravity: 1.10±0.05 (g/cm ³ @25°C; elongation: 310%; shrinkage: 10, functional base (Theoretical value): 2. Highly flexible urethane acrylate, high elongation, high gloss, good adhesion and surface dryness, low shrinkage, and excellent comprehensive performance.

Wherein the modified epoxy acrylate comprises 50 parts by weight of polypropylene glycol, 40 parts of acid anhydride, 2 parts of organic bismuth, 50 parts of E51 epoxy resin, 1 part of paraoxyphenol and 20 parts of acrylic acid Prepared by the following method:

Add polypropylene glycol (PPG400), acid anhydride and 1 part of organic bismuth of formula amount in the reaction kettle equipped with stirrer, thermometer, condenser (reflux), nitrogen pipe and constant pressure dripping equipment, under nitrogen protection, Raise the temperature to 80°C and react for 3 hours;

Add the formula amount of E51 epoxy resin (Kunshan Nanya epoxy resin) and the balance of organic bismuth, and heat up to 85°C to continue the reaction;

Add the formulated amount of p-oxyphenol and dropwise added the formulated amount of acrylic acid, raise the temperature to 95°C to react, when the acid value of the system is less than 5mgKOH/g, stop the reaction, lower to normal temperature and discharge.

The indicators of the prepared modified epoxy acrylate are as follows: light yellow liquid at 25°C, viscosity: 200,000-350,000 (cps@25°C), acid value: no more than 5.0 (mgKOH/g) , Chromatic number: no more than 2 (Gardner), functional base (theoretical value) is 2. It does not contain diluting monomers. Compared with general bisphenol A acrylate oligomers, it provides extremely high gloss, excellent toughness, and also has excellent curing speed and low shrinkage.

Wherein the monomer (monofunctional or difunctional) includes by weight parts:

5 parts of diethoxy 1,6 hexanediol diacrylate;

2 parts of 2-ethoxy-phenol acrylate;

2 parts of acrylamide morpholine;

Lauric acid acrylate 7 parts.

Wherein the photoinitiator includes 3 parts of 2-hydroxyl-2-methyl-1-phenyl-1-propanone (photoinitiator 1173), 0.3 part of 1-hydroxycyclohexyl benzophenone (photoinitiator Agent 184), 0.2 parts of (photoinitiator TPO).

The additives include 0.5g leveling agent (Tego Glide) and 0.5g defoamer (Tego2100) in parts by weight.

The product performance index of the solvent-free leather highlight UV varnish of this embodiment is shown in Table 1 below.

Example 5

A preparation process for solvent-free leather highlighting UV varnish, comprising the following steps:

a. Add any group of difunctional aliphatic urethane acrylate, modified epoxy acrylate, monomers, and additives (leveling agent and defoaming agent) in sequence in Examples 1-4 and add them at room temperature Mixing and stirring, the stirring time is not less than 30 minutes, then add photoinitiator (photoinitiator 1173, photoinitiator 184 and TPO), continue to stir for 20 minutes, the stirring speed range is 500-800 rpm, get mixed solution;

b. Stir until the mixed solution is clear and transparent without suspended solids to prepare the solvent-free leather highlighting UV varnish.

Example 6

Comparative example: MU-609 solvent-based leather high-gloss varnish produced by Taiwan Zhanyu, specific specifications: solid content: 60%, viscosity: 120-320cps/25 degrees; solvent: ethyl ester/xylene/alcohol ether, NCO content %: 2.7-3.4%.

Carry out performance test as shown in table 1 to the solvent-free leather highlight UV varnish by embodiment 1-4:

Table 1 Performance test table of solvent-free leather highlight UV varnish

It can be seen from Table 1 that the solvent-free leather highlight UV varnish of Examples 1-4 can be hard-dried after UV irradiation, completely hard-dried after about 1 minute, and can be followed up after cooling for 3-5 minutes. The light curing speed is much faster than the commercially available solvent-based leather high-gloss varnish.

Finally, it should be noted that: the above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand : It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements to some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention range.

Claims (10)

1. A solvent-free leather high-gloss UV varnish, characterized in that, the UV varnish comprises 70 to 80 parts of difunctional aliphatic urethane acrylates, 5-15 parts of modified epoxy acrylates in parts by weight. 10-15 parts of monomer, 1-5 parts of photoinitiator, and 0.5-1.5 parts of auxiliary agent. 2. The solvent-free leather highlighting UV varnish according to claim 1, is characterized in that, said difunctional aliphatic urethane acrylate comprises 15-45 parts of polyols and 10-45 parts of diisocyanate by weight parts. 0.2-2 parts of catalyst organic bismuth, 0.1-1 part of polymerization inhibitor p-oxyphenol and 15-30 parts of hydroxyethyl acrylate are prepared according to the following method: Add the formulated amount of polyol into the reaction kettle, heat up to 110-120°C, and vacuum dehydrate for 1-2 hours; Then cool down to 40-50°C, while stirring, add diisocyanate dropwise, stir evenly, then raise the temperature to 70-80°C, and react for 2-3h; Add 0.1-1 part of organic bismuth catalyst, react for 0.5-1h, cool down to 50-60°C, vacuumize and defoam until the content of isocyanate groups reaches 2-15%; Add the polymerization inhibitor p-oxyphenol and the rest of the organic bismuth catalyst, mix evenly and add the formulated amount of hydroxyethyl acrylate dropwise until the content of isocyanate group is less than 0.5%, then stop the reaction, drop to normal temperature and discharge. 3. The solvent-free leather highlight UV varnish according to claim 2, characterized in that, the polyol is a polyether polyol with a molecular weight between 200-1000, a polyester with a molecular weight between 400-1000 Any one of polyol or polycarbonate diol; The diisocyanate is any one of isophorone diisocyanate, dicyclohexylmethane diisocyanate and hexamethylene-1,6-diisocyanate. 4. The solvent-free leather highlight UV varnish according to claim 1 is characterized in that, the modified epoxy acrylate comprises 10-50 parts by weight of polypropylene glycol, 10-40 parts of acid anhydride, organic 0.2-2 parts of bismuth, 10-50 parts of E51 epoxy resin, 0.1-1 part of p-oxyphenol and 5-20 parts of acrylic acid are prepared according to the following method: Add the formula amount of polypropylene glycol, acid anhydride and 0.1-1% organic bismuth into the reaction kettle, and raise the temperature to 70-80°C under the protection of nitrogen, and react for 2-3 hours; Add the amount of E51 epoxy resin and the remaining organic bismuth, and heat up to 80-90°C to continue the reaction; Add the formulated amount of p-oxyphenol and acrylic acid, raise the temperature to 90-95°C for reaction, stop the reaction when the acid value of the system is less than 5mgKOH/g, lower to normal temperature and discharge. 5. solvent-free leather highlight UV varnish according to claim 1, is characterized in that, described monomer comprises the following components in parts by weight: Diethoxy-1,6-hexanediol diacrylate 1-5; 2-Ethoxy-phenol acrylate 1-5; Acrylamidomorpholine 1-5 Lauric Acrylate 4-8. 6. solvent-free leather highlight UV varnish according to claim 1, is characterized in that, described photoinitiator comprises the following components by weight parts: 2-Hydroxy-2-methyl-1-phenyl-1-propanone 1.0-3.0; 1-Hydroxy-cyclohexyl benzophenone 0.3-1.0; 2,4,6-Trimethylbenzoyl-diphenylphosphine oxide 0.2-1.0. 7. The solvent-free leather highlighting UV varnish according to claim 1, wherein the auxiliary agent comprises the following components in parts by weight: Leveling agent 0.5-1.0; Deaerator 0.3-0.5. 8. A preparation process for solvent-free leather highlighting UV varnish, characterized in that it comprises the following steps: a. Weigh the bifunctional aliphatic urethane acrylate, modified epoxy acrylate, mono- and difunctional monomers, photoinitiators and auxiliary agents according to the formula quantity, add them in sequence and mix and stir at room temperature, get mixed solution; b. Stir until the mixed solution is clear and transparent without suspended solids to prepare the solvent-free leather highlighting UV varnish. 9. The solvent-free leather highlight UV coating according to claim 8, characterized in that the stirring time is not less than 50 minutes, and the stirring speed range is 500-800 rpm. 10. according to the application of solvent-free leather highlighting UV varnish described in any one of claim 1-7 in leather coating.