阅读说明：本技术 一种转移纸用水性自交联转移涂料及其制备方法 (Water-based self-crosslinking transfer coating for transfer paper and preparation method thereof ) 是由 陈兴耀 黄艳轶 陈森 谭振 黄志荣 于 2020-12-25 设计创作，主要内容包括：为克服现有技术中水性转移涂料涂层放置剥离稳定性差,单组份涂料涂层交联密度不足,转移性、耐溶剂、柔韧性差等问题,本发明提供了一种转移纸用水性自交联转移涂料,包括：水性有机硅改性转移树脂30-70重量份,水溶性交联剂0.5-5重量份,酒精10-15重量份,分散剂0.1-1重量份,水60-15重量份；所述水性有机硅改性转移树脂为含有链端羰基结构的水性有机硅改性聚氨酯树脂；所述水溶性交联剂包括有机酸二酰肼、芳香族碳酰肼中的一种或多种。同时,本发明还公开了上述转移纸用水性自交联转移涂料的制备方法。本发明提供的转移纸用水性自交联转移涂料具有更优的耐溶剂性、转移性、涂层柔韧性和耐温性,并且施工便利,有效性长,有助于提升转移纸产品的质量。(In order to overcome the problems of poor placing and peeling stability of a water-based transfer coating, insufficient crosslinking density of a single-component coating, poor transferability, solvent resistance, poor flexibility and the like in the prior art, the invention provides a water-based self-crosslinking transfer coating for transfer paper, which comprises the following components in percentage by weight: 30-70 parts of water-based organic silicon modified transfer resin, 0.5-5 parts of water-soluble cross-linking agent, 10-15 parts of alcohol, 0.1-1 part of dispersing agent and 60-15 parts of water; the waterborne organic silicon modified transfer resin is waterborne organic silicon modified polyurethane resin containing a chain-end carbonyl structure; the water-soluble cross-linking agent comprises one or more of organic acid dihydrazide and aromatic carbohydrazide. Meanwhile, the invention also discloses a preparation method of the waterborne self-crosslinking transfer coating for the transfer paper. The waterborne self-crosslinking transfer coating for the transfer paper provided by the invention has better solvent resistance, transferability, coating flexibility and temperature resistance, is convenient to construct and long in effectiveness, and is beneficial to improving the quality of the transfer paper product.)

1. An aqueous self-crosslinking transfer coating for transfer paper, comprising: 30-70 parts of water-based organic silicon modified transfer resin, 0.5-5 parts of water-soluble cross-linking agent, 10-15 parts of alcohol, 0.1-1 part of dispersing agent and 65-15 parts of water;

the waterborne organic silicon modified transfer resin is waterborne organic silicon modified polyurethane resin containing a chain-end carbonyl structure;

the water-soluble cross-linking agent comprises one or more of organic acid dihydrazide and aromatic carbohydrazide.

2. The aqueous self-crosslinking transfer coating for transfer paper of claim 1, wherein the silicone content in the aqueous silicone-modified transfer resin is 1 to 5%.

3. The aqueous self-crosslinking transfer coating for transfer paper according to claim 1 or 2, wherein the preparation method of the aqueous silicone-modified transfer resin comprises the steps of:

in the nitrogen atmosphere, polyester polyol or polyether polyol is mixed with polyhydroxy silicone oil, an isocyanate compound, dimethylolpropionic acid, a catalyst, a diol compound and a 2-ketohydroxyl compound, and the mixture is reacted under the heating condition;

and then adding organic neutralizing amine and deionized water, dispersing and emulsifying at a high speed, and then adding an organic diamine chain extender for chain extension to obtain the water-based organic silicon modified transfer resin.

4. The aqueous self-crosslinking transfer coating for transfer paper according to claim 3,

in the preparation method of the waterborne organic silicon modified transfer resin, 80-100 parts by weight of polyester polyol or polyether polyol and 1.3-6.5 parts by weight of polyhydroxy silicone oil are firstly vacuumized and dehydrated for 1-3h at the temperature of 100-110 ℃, then the temperature is reduced to 40-60 ℃, nitrogen is introduced, then 20-25 parts by weight of isocyanate compound and 0.1-0.3 part by weight of catalyst are added, then the temperature is raised to 60-80 ℃, and the temperature is kept for 1-3 h;

then adding 5-10 parts by weight of dimethylolpropionic acid and 6-8 parts by weight of glycol compound, preserving heat for 1-3h at 80-90 ℃, adding acetone to adjust viscosity in the reaction process, continuously adding 4-8 parts by weight of 2-ketohydroxyl compound, preserving heat for 1-3h at 80-90 ℃, then cooling to 40 ℃, adding 4-5 parts by weight of organic neutralizing amine and 380 parts by weight of deionized water, dispersing and emulsifying at high speed, dropwise adding 0.1-0.3 part by weight of organic diamine chain extender, and removing the acetone in the system by vacuumizing to obtain the aqueous organic silicon modified transfer resin.

5. The aqueous self-crosslinking transfer coating for transfer paper of claim 3, wherein the polyester polyol comprises one or more of polybutylene adipate, polyhexamethylene adipate, neopentyl glycol adipate, polycaprolactone diol, polycarbonate diol;

the polyether polyol comprises one or more of polypropylene glycol, polytetramethylene glycol or polytetrahydrofuran glycol;

the polyhydroxy silicone oil is a polyether-polysiloxane copolymer with hydroxyl groups at two ends of a molecular chain, and the weight average molecular weight is 1500-4000;

the isocyanate compound comprises one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate or isophorone diisocyanate;

the catalyst is an organic metal catalyst, and the organic metal catalyst comprises one or two of an organic tin catalyst or an organic bismuth catalyst;

the diol compound comprises one or more of 1, 4-butanediol, ethylene glycol, diethylene glycol, propylene glycol, 1, 4-cyclohexanol, hydrogenated bisphenol A and neopentyl glycol;

the 2-ketone hydroxyl group compound comprises one or more of ethylene glycol monoacetyl ester, 1, 2-propylene glycol monoacetyl ester, 1, 3-propylene glycol monoacetyl ester, 1, 4-butylene glycol monoacetyl ester, 1, 3-butylene glycol monoacetyl ester, 1, 2-butylene glycol monoacetyl ester, glycerol diacetoacetyl ester, neopentyl glycol monoacetyl ester, pentaerythritol diacetoacetyl ester, pentaerythritol triacetoacetyl ester;

the organic neutralizing amine comprises one or more of trimethylamine, triethylamine, tripropylamine, triisopropylamine, diisopropylethylamine, N-diethylethanolamine, N-dimethylethanolamine and N, N-dipropylethanolamine;

the organic diamine chain extender comprises one or two of ethylenediamine and isophorone diamine.

6. The aqueous self-crosslinking transfer coating for transfer paper of claim 1, wherein the water-soluble crosslinking agent comprises one or more of succinic dihydrazide, adipic dihydrazide, glutaric dihydrazide, pimelic dihydrazide, suberic dihydrazide, azelaic dihydrazide, sebacic dihydrazide, diphenylcarbohydrazide.

7. The aqueous self-crosslinking transfer coating for transfer paper of claim 1, wherein the dispersant comprises one or more of a polyether-modified silicone-based dispersant or an acrylic dispersant.

8. The aqueous self-crosslinking transfer coating for transfer paper of claim 1, further comprising 0.05 to 0.5 parts by weight of an auxiliary agent, the auxiliary agent comprising one or more of a leveling agent, an antifoaming agent and an antistatic agent.

9. The aqueous self-crosslinking transfer coating for transfer paper according to claim 8, wherein the leveling agent comprises one or more of an acrylic leveling agent, a polyether polyester modified organosiloxane leveling agent;

the defoaming agent comprises one or more of a modified polydimethylsiloxane defoaming agent, a polyoxypropylene glycerol ether defoaming agent and a high-carbon alcohol fatty acid ester compound defoaming agent;

the antistatic agent is an alkyl sodium sulfonate antistatic agent.

10. A method of preparing an aqueous self-crosslinking transfer coating for transfer paper as claimed in any one of claims 1 to 9, comprising the steps of:

blending the water-based organic silicon modified transfer resin, alcohol and water, and uniformly stirring to obtain a mixture A;

adding a dispersing agent into the mixture A under the stirring state to obtain a mixture B;

adding a water-soluble cross-linking agent into the mixture B under the stirring state to obtain a mixture C;

and filtering to obtain the water-based single-component self-crosslinking transfer coating.

Technical Field

The invention belongs to the technical field of transfer coatings, and particularly relates to a water-based self-crosslinking transfer coating for high-gloss paper and a preparation method thereof.

Background

In recent years, with the enhancement of environmental awareness, how to realize green printing has become a direction that paper printing enterprises must go to practice. In the printing process, due to the use of a large amount of solvent-based ink, the proportion of VOCs discharged in printing enterprises reaches 98%. In the current situation that the water-based environment-friendly ink is not applied in a mature way, how to reduce the consumption of the ink while maintaining the printing effect is the key for reducing the discharge of VOCs in the printing process.

The base paper treated by the transfer process is compounded with a layer of high-brightness barrier coating on a paper product, so that the effects of reducing the ink absorption of the base paper and reducing the ink consumption are achieved. Meanwhile, because the surface gloss of the transfer coating layer is high, the base paper treated by the transfer process does not reduce the fullness, the gloss and the like of printed matters but is greatly improved while the ink consumption is reduced. In view of this, transfer coatings have been used more and more widely in the base paper treatment process in recent years.

The transfer coating is prepared by coating the coating on the surface of a PET, OPP and other base materials, adhering the coating to other base materials through glue after a plurality of modification processes such as coloring, mould pressing, aluminizing, printing and the like, and then removing the PET, OPP and other base materials, thereby transferring a modification layer to the surface of another base material. With the development of society, the technology is generally used in the fields of cigarettes, wines, foods, cosmetics, daily necessities, building materials and the like at present, and has the functions of ensuring the product to be attractive and bright, saving the consumption of printing ink, preventing the product from being packaged and preventing the substrate from being corroded or scratched and the like.

At present, most of coatings applied to the field on the market are oil coatings, the content of volatile organic solvents reaches 60-80%, and a large amount of solvents such as ketones, esters and benzenes are used, so that the requirements of a green industrial chain are not met. Therefore, the research focus at present is gradually focused on the water-based paint, and the water-based paint takes water as a main dispersion medium, has obvious environmental protection advantages, and is superior to an oily transfer material in the aspects of physical health of field operation workers, storage safety, production discharge and the like in the using process.

Thus, waterborne transfer coatings began to appear on the market. In terms of transferability, most of the existing water-based transfer coatings on the market reduce the adhesive force between the coating and the PET film by adding small molecular compounds, so that the compounded coating can be separated from the PET film surface to achieve the effect of transferring, but in the process of placing the coating, the problem of migration of the small molecular compounds is easy to occur, the peeling force of the coating is gradually increased, and the transferability is influenced.

Patent CN105153844A discloses a proposal of introducing organosilicon modified acrylic resin and water-soluble silica sol into aqueous polyurethane resin for the purpose of improving the smoothness of the coating surface, and patent CN108624216A discloses a proposal of introducing silane coupling agent during the synthesis process of aqueous polyurethane resin. The scheme improves the problem of tight placement of the stripped coating to a certain extent, but the flexibility of the coating is reduced, so that the overall stripping effect of the coating is poor.

Patent CN101759861A discloses a scheme of synthesizing waterborne polyurethane containing active carbonyl group by using diacetone acrylamide and simultaneously introducing dihydrazide compounds for self-crosslinking. The system can obtain a coating with good solvent resistance, but the adhesion between the coating and the PET film is large, and the transfer effect cannot be achieved.

Meanwhile, two-component or three-component packaged water-based transfer coatings are also available in the market, but special cross-linking agents such as aziridine, carbodiimide and the like are required to be introduced during field construction. As described in patent CN108329813A, by introducing carbodiimide, aziridine, etc. into the aqueous polyurethane for crosslinking, the flexibility and crosslinking density of the coating can be significantly improved. The crosslinking agents are crosslinked with carboxyl in resin to improve the solvent resistance, flexibility, transfer integrity and the like of the coating, but the auxiliary agents have high activity, so that the problems of short construction time, incapability of reusing residual coating, inconvenience in operation and the like exist, and the auxiliary agents increase the adhesive force between the coating and the PET film to a certain extent, so that the peeling force is increased, and the risk of large bulk transfer insufficiency exists. And the crosslinking agent with lower activity, such as blocked isocyanate and the like, cannot perform crosslinking reaction to improve the performance of the coating because the time for high-temperature construction of the coating is very short and the deblocking condition cannot be achieved.

Disclosure of Invention

The invention aims to solve the technical problems that in the prior art, an oil-based coating is large in environmental pollution, a water-based transfer coating is poor in placement and stripping stability, a single-component coating is insufficient in crosslinking density, poor in transferability, solvent resistance and flexibility, narrow in application range, short in use time of a water-based two-component coating, poor in construction convenience and the like, and provides a water-based self-crosslinking transfer coating for transfer paper.

The technical scheme adopted by the invention for solving the technical problems is as follows:

provided is a water-based self-crosslinking transfer coating for transfer paper, which comprises: 30-70 parts of water-based organic silicon modified transfer resin, 0.5-5 parts of water-soluble cross-linking agent, 10-15 parts of alcohol, 0.1-1 part of dispersing agent and 65-15 parts of water; the waterborne organic silicon modified transfer resin is waterborne organic silicon modified polyurethane resin containing a chain-end carbonyl structure; the water-soluble cross-linking agent comprises one or more of organic acid dihydrazide and aromatic carbohydrazide.

The inventor finds that in the prior art, schemes such as introducing organosilicon-modified acrylic resin and water-soluble silica sol into the aqueous polyurethane resin or introducing a silane coupling agent into the synthetic process of the aqueous polyurethane resin can generate large negative effects on the flexibility of the coating due to the introduction of the acrylic resin and the silane coupling agent, and finally the overall stripping effect of the coating is affected.

In the waterborne self-crosslinking transfer coating for transfer paper provided by the invention, the waterborne organosilicon modified transfer resin is waterborne organosilicon modified polyurethane resin containing a chain-end carbonyl structure, on one hand, the resin structure contains organosilicon groups, so that the adhesive force between a coating and a PET (polyethylene terephthalate) film can be effectively reduced, the coating has good and stable stripping property after film forming, and the problems that in the prior art, the stripping force between the coating and the PET film is increased and the transfer property is poor due to the placement of the coating and the migration of small molecular compounds when the stripping property is improved by introducing the small molecular compounds such as acrylic resin, silane coupling agent and the like can be solved; on the other hand, the resin structure contains a chain-end carbonyl structure, can stably coexist with hydrazide compounds under neutral or alkaline conditions, organic neutralizing amine gradually volatilizes along with the coating in the coating process and the curing process of a coating film, a coating system slowly shows acidity, and the crosslinking reaction of the water-based organic silicon modified transfer resin and a water-soluble crosslinking agent is initiated, so that the crosslinking density of the coating is improved, the solvent resistance and the peeling strength of the coating are improved, the reaction can be carried out at room temperature, and the prior art is met.

In addition, the water-based self-crosslinking transfer coating for transfer paper provided by the invention uses water and alcohol as solvents to disperse the water-based organic silicon modified transfer resin, so that the use of organic solvents can be avoided, and the pollution to the environment in the production process can be reduced.

The water-based self-crosslinking transfer coating for the transfer paper adopts water-based organic silicon modified transfer resin as a main material, is matched with a water-soluble crosslinking agent, and is relatively matched with a double-component water-based transfer coating.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects solved by the present invention more apparent, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a water-based self-crosslinking transfer coating for transfer paper, which comprises the following components: 30-70 parts of water-based organic silicon modified transfer resin, 0.5-5 parts of water-soluble cross-linking agent, 10-15 parts of alcohol, 0.1-1 part of dispersing agent and 65-15 parts of water; the waterborne organic silicon modified transfer resin is waterborne organic silicon modified polyurethane resin containing a chain-end carbonyl structure; the water-soluble cross-linking agent comprises one or more of organic acid dihydrazide and aromatic carbohydrazide.

According to the present invention, the terminal of the molecular chain of the aqueous silicone-modified transfer resin contains a hydroxyl group, and the molecule contains a silicone group. Preferably, the softening temperature of the aqueous silicone-modified transfer resin is 120 ℃ or higher. More preferably, the average particle size of the aqueous silicone-modified transfer resin is 200nm or less.

The waterborne organic silicon modified transfer resin can be prepared by the following method: in the nitrogen atmosphere, polyester polyol or polyether polyol is mixed with polyhydroxy silicone oil, an isocyanate compound, dimethylolpropionic acid, a catalyst, a diol compound and a 2-ketohydroxyl compound, and the mixture is reacted under the heating condition; and then adding organic neutralizing amine and deionized water, dispersing and emulsifying at a high speed, and then adding an organic diamine chain extender for chain extension to obtain the water-based organic silicon modified transfer resin.

Specifically, in a preferred case, the polyester polyol or polyether polyol and the polyhydroxy silicone oil are firstly subjected to vacuum dehydration, and the specific method can be as follows: the polyester polyol or the polyether polyol and the polyhydroxy silicone oil are dehydrated for 1 to 3 hours in a vacuum pumping way at the temperature of 100-110 ℃.

After vacuum dehydration, cooling polyester polyol or polyether polyol and polyhydroxy silicone oil to 40-60 ℃, then introducing nitrogen, then adding isocyanate compounds and catalysts, then heating to 60-80 ℃, and preserving heat for 1-3 hours.

And adding dimethylolpropionic acid and a diol compound, keeping the temperature for 1-3h at 80-90 ℃, adding acetone to adjust the viscosity in the reaction process, continuously adding a 2-ketohydroxyl compound, keeping the temperature for 1-3h at 80-90 ℃, then cooling to 40 ℃, adding organic neutralizing amine and deionized water, dispersing and emulsifying at a high speed, dropwise adding an organic diamine chain extender, and vacuumizing to remove the acetone in the system to obtain the aqueous organic silicon modified transfer resin.

In the preparation of the above-mentioned aqueous organosilicon modified transfer resin, the relative contents of the components can be selected by those skilled in the art according to the molecular weight of the desired resin based on the general knowledge of organic synthesis, preferably, in the above-mentioned preparation method, the addition amount of the polyester polyol or polyether polyol is 80-100 parts by weight, the addition amount of the polyhydroxy silicone oil is 1.3-6.5 parts by weight, the addition amount of the isocyanate compound is 20-25 parts by weight, the addition amount of the catalyst is 0.1-0.3 part by weight, the addition amount of the dimethylolpropionic acid is 5-10 parts by weight, the addition amount of the diol compound is 6-8 parts by weight, the addition amount of the 2-ketohydroxyl compound is 4-8 parts by weight, the addition amount of the organic neutralizing amine is 4-5 parts by weight, the addition amount of the deionized water is 350-380 parts by weight, the addition amount of the organic diamine chain extender is 0.1 to 0.3 weight part.

According to the present invention, the theoretical weight average molecular weight of the above aqueous silicone-modified transfer resin is preferably 20000-50000. The silicon content in the aqueous organosilicon modified transfer resin can be adjusted by adjusting each component in the synthetic raw materials, and preferably, the silicon content in the aqueous organosilicon modified transfer resin is 1-5%.

In the above preparation method, the polyester polyol preferably comprises one or more of polybutylene adipate, polyhexamethylene adipate, neopentyl glycol adipate, polycaprolactone diol and polycarbonate diol.

The polyether polyol preferably comprises one or more of polypropylene glycol, polytetramethylene glycol or polytetrahydrofuran glycol.

The polyhydroxy silicone oil is preferably polyether-polysiloxane copolymer with hydroxyl at both ends of molecular chain, and is more preferably polyhydroxy silicone oil with weight average molecular weight of 1500-4000. As the above-mentioned polyhydroxy silicone oil, hydroxyethyl-terminated polydimethylsiloxane can be specifically used.

The isocyanate-based compound preferably includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate or isophorone diisocyanate.

The catalyst is preferably an organic metal catalyst, and more preferably, the organic metal catalyst includes one or both of an organotin-based catalyst and an organobismuth-based catalyst, and for example, dibutyltin dilaurate may be used specifically.

The diol compound preferably comprises one or more of 1, 4-butanediol, ethylene glycol, diethylene glycol, propylene glycol, 1, 4-cyclohexanol, hydrogenated bisphenol a, neopentyl glycol.

The 2-ketone hydroxyl group compound preferably includes one or more of ethylene glycol monoacetyl ester, 1, 2-propylene glycol monoacetyl ester, 1, 3-propylene glycol monoacetyl ester, 1, 4-butylene glycol monoacetyl ester, 1, 3-butylene glycol monoacetyl ester, 1, 2-butylene glycol monoacetyl ester, glycerol diacetoacetyl ester, neopentyl glycol monoacetyl ester, pentaerythritol diacetoacetyl ester, pentaerythritol triacetoacetyl ester.

The organic neutralizing amine preferably comprises one or more of trimethylamine, triethylamine, tripropylamine, triisopropylamine, diisopropylethylamine, N-diethylethanolamine, N-dimethylethanolamine, and N, N-dipropylethanolamine.

The organic diamine chain extender preferably comprises one or two of ethylenediamine and isophorone diamine.

According to the invention, one or more of organic acid dihydrazide and aromatic carbohydrazide is used as the water-soluble crosslinking agent. More preferably, the water-soluble cross-linking agent comprises one or more of succinic dihydrazide, adipic dihydrazide, glutaric dihydrazide, pimelic dihydrazide, suberic dihydrazide, azelaic dihydrazide, sebacic dihydrazide, and diphenylcarbohydrazide.

In the present invention, it is preferable that the dispersant includes one or more of a polyether-modified siloxane-based dispersant or an acrylic dispersant.

In the water-based self-crosslinking transfer coating for transfer paper disclosed by the invention, the alcohol is preferably food-grade alcohol, and the water is preferably deionized water.

In order to ensure that the waterborne self-crosslinking transfer coating for transfer paper has more excellent comprehensive performance, preferably,

the waterborne self-crosslinking transfer coating for transfer paper further comprises an auxiliary agent, and the auxiliary agent selectively contains one or more of a flatting agent, a defoaming agent and an antistatic agent according to the function to be realized.

As is well known to those skilled in the art, a leveling agent is a coating additive which is effective in improving the leveling property and uniformity of a coating, and can promote the coating to form a flat, smooth and uniform coating film in the process of drying and film forming. Specifically, the leveling agent comprises one or more of an acrylic leveling agent and a polyether polyester modified organosiloxane leveling agent.

The defoaming agent is used for inhibiting and eliminating foam generated in the preparation process of the coating, and avoiding bubbles in the coating. Specifically, the defoaming agent comprises one or more of a modified polydimethylsiloxane defoaming agent, a polyoxypropylene glycerol ether defoaming agent and a high-carbon alcohol fatty acid ester compound defoaming agent.

Antistatic agents are additives that are added to plastics or applied to the surface of molded articles to reduce static buildup. Specifically, the antistatic agent is an alkyl sodium sulfonate antistatic agent.

According to the present invention, it is preferable that the addition amount of the auxiliary is 0.05 to 0.5 part by weight, and the addition amounts of the leveling agent, the defoaming agent and the antistatic agent may be added as needed, and the total content is within the above range.

It is understood that the content of each component and material in the present invention is in parts by weight, not in percentage by weight.

The coating formed by the waterborne self-crosslinking transfer coating for the transfer paper provided by the invention has small adhesive force with a base film (such as a PET film), and the peeling strength can reach below 8 gj/cm.

Meanwhile, the invention also provides a preparation method of the waterborne self-crosslinking transfer coating for the transfer paper, which comprises the following steps:

blending the water-based organic silicon modified transfer resin, alcohol and water, and uniformly stirring to obtain a mixture A;

adding a dispersing agent into the mixture A under the stirring state to obtain a mixture B;

adding a water-soluble cross-linking agent into the mixture B under the stirring state to obtain a mixture C;

and filtering to obtain the water-based single-component self-crosslinking transfer coating.

When it is desired to add an auxiliary agent, it is understood that an auxiliary agent including one or more of a leveling agent, an antifoaming agent, and an antistatic agent is added to the mixture C to give a mixture D.

Preferably, in the preparation method of the water-based self-crosslinking transfer coating for transfer paper, the stirring speed is 800-.

The aqueous self-crosslinking transfer coating for the transfer paper of the high-gloss paper, which is obtained by the preparation method, has good leveling property, solvent resistance, flexibility, adhesive force with glue and other comprehensive properties on the basis of ensuring the release property and the transfer property. And volatile matters used in the water-based self-crosslinking transfer coating for transfer paper are various alcohols with good environmental compatibility, so that the water-based self-crosslinking transfer coating for transfer paper is really environment-friendly.

The water-based self-crosslinking transfer coating for transfer paper provided by the invention is suitable for PET films and opp films.

The present invention will be further illustrated by the following examples.

Example 1

This example illustrates the aqueous self-crosslinking transfer coating for transfer paper and the method of making the same disclosed in this invention.

The method comprises the following steps: adding 80 parts by weight of polyester polyol (polyester polyol PBA2000 based on adipic acid, 1, 4-butanediol and ethylene glycol, the hydroxyl value is 50-60, the molecular weight is 2000, and the polyester polyol PBA is obtained from Asahi Chun chemical Co., Ltd.) and 1.3 parts by weight of hydroxyethyl terminated polydimethylsiloxane into a reaction kettle, heating to 100 ℃ and 110 ℃, vacuumizing and dehydrating for 2 hours, cooling to 50 ℃, introducing nitrogen, adding 23 parts by weight of toluene diisocyanate and 0.1 part by weight of dibutyltin dilaurate, heating to 70 ℃, and keeping the temperature for 2 hours. Adding 6.5 parts by weight of DMPA and 7 parts by weight of 1, 4-butanediol, preserving heat for 2 hours at the temperature of 80-90 ℃, adding a proper amount of acetone to reduce viscosity in the reaction process, continuously adding 6.0 parts by weight of 1, 3-propylene glycol monoacetyl ester, preserving heat for 2 hours at the temperature of 80-90 ℃, continuously preserving heat for 1 hour, cooling to 40 ℃ after heat preservation is finished, adding 4.5 parts by weight of triethylamine, adding 371 parts by weight of deionized water, dispersing and emulsifying at high speed, dropwise adding 0.2 part by weight of ethylenediamine chain extender, and vacuumizing to remove the acetone in the system to obtain the waterborne organosilicon modified polyurethane resin containing the terminal carbonyl structure, wherein the silicon content of the waterborne organosilicon modified polyurethane resin is 1%.

Step two: 60 parts by weight of water-based organic silicon modified polyurethane resin, 10 parts by weight of alcohol and 29.2 parts by weight of deionized water are mixed in a reaction kettle, and the mixture is stirred at a low speed for 10min, wherein the stirring speed is controlled at 500 rpm.

Step three: and (3) increasing the stirring speed to 1000rpm, adding 0.2 part by weight of polyether modified siloxane dispersant into the reaction kettle in a stirring state, and stirring for 5 min.

Step four: keeping the stirring speed, adding 0.8 weight part of adipic acid dihydrazide, 0.05 weight part of flatting agent, 0.01 weight part of defoaming agent and 0.05 weight part of antistatic agent into the reaction kettle under the stirring state, and stirring for 5 min.

Step five: filtering by using a 200-mesh and 300-mesh filter screen, and packaging to obtain the water-based self-crosslinking transfer coating for the transfer paper.

Example 2

This example illustrates the aqueous self-crosslinking transfer coating for transfer paper and the method of making the same disclosed in this invention.

An aqueous self-crosslinking transfer coating for transfer paper was prepared as in example 1, except that: the silicon content of the water-based organic silicon modified transfer resin is 3%, and the content of each component of the water-based self-crosslinking transfer coating for transfer paper is adjusted, as shown in table 1.

Example 3

This example illustrates the aqueous self-crosslinking transfer coating for transfer paper and the method of making the same disclosed in this invention.

An aqueous self-crosslinking transfer coating for transfer paper was prepared as in example 1, except that: the silicon content of the water-based organic silicon modified transfer resin is 5%, and the content of each component of the water-based self-crosslinking transfer coating for transfer paper is adjusted, as shown in table 1.

Performance testing

The aqueous self-crosslinking transfer coating materials for transfer paper prepared in examples 1 to 3 were subjected to performance tests on a commercially available one-pack aqueous transfer coating material ST201 (comparative example 1), a commercially available two-pack aqueous transfer coating material ST370 (comparative example 2), a commercially available solvent transfer coating material YST650 (comparative example 3), according to the following methods:

the coating effect test method comprises the following steps: the leveling effect of the coating on the PET film was tested on a coater using a200 mesh ceramic roller at a coating speed of 100 m/min.

Peel force test method: the test was carried out on a tape peel force tester PT-501C.

The method for testing the alcohol-resistant wiping times comprises the following steps: the coating is transferred to a paperboard, a standard heavy hammer of 1kg wound with dust-free cloth is thoroughly wetted by alcohol, and the paperboard is horizontally placed and pushed and pulled forcefully back and forth, so that the wiping frequency when the coating is just damaged is inspected.

Ethyl acetate resistance wipe number test method: the coating is transferred to a paperboard, a standard weight of 1kg wound with dust-free cloth is thoroughly moistened by ethyl acetate, the paperboard is horizontally placed and pushed and pulled forcefully back and forth, and the wiping frequency when the coating is just damaged is inspected.

The testing method of the residual VOCs of the solvent comprises the following steps: and (4) counting the residual quantity of various solvents on the coating film by using a headspace gas chromatograph.

The placing stability test method comprises the following steps: after 150g of the paint sample was placed in a 50 ℃ oven for 15 days, the presence of bleeding or viscosity increase was observed.

Method for testing surface tension of coating after transfer: the test was performed using a dyne pen.

The method for testing the leveling property of the gravure ink after transfer comprises the following steps: and after the coating transfer film is transferred to the base paper, the PET film is removed, common oily ink is printed on the release layer through a small gravure press, and the existence of obvious leveling defects is observed.

Gloss test method: after the coating transfer film is transferred to the base paper, the PET film is removed, and the corrected color difference meter is used for testing the L value

The test results obtained are filled in Table 1.

TABLE 1

From the test results in table 1, it can be seen that, with the increase of the silicon content, the leveling property of the coating prepared by using the aqueous organosilicon modified transfer resin of the present invention is deteriorated, the peeling force is reduced, the solvent resistance is improved, the surface tension of the coating is obviously reduced, the printing adaptability is reduced, the stability of the coating is reduced, and the glossiness is reduced.

The waterborne self-crosslinking transfer coating for transfer paper prepared from the waterborne organosilicon modified transfer resin with the silicon content of 3% has good coating leveling property and lower stripping force, the solvent resistance of the cured coating is equivalent to that of a two-component waterborne transfer coating, the VOCs of the coating are qualified, the surface tension is reduced, and the printing effect is not influenced.

The invention completely adopts a water-based resin system, and the used raw materials belong to environment-friendly materials, so the water-based transfer coating is really environment-friendly.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.