CN114933690A - Method for preparing stain-resistant ultraviolet curing resin by utilizing core-shell structure - Google Patents

Abstract

The invention provides a method for preparing stain-resistant ultraviolet curing resin by utilizing a core-shell structure, which comprises the following steps: preparing an isocyanate end group prepolymer by reacting organic silicon hydroxyl dihydric alcohol, polyol, dihydroxy carboxylic acid and diisocyanate, and then carrying out end capping by adopting a high-functionality acrylic acid hydroxyl-containing monomer to prepare a prepolymer A; preparing a prepolymer B by adopting diisocyanate, a polyacrylic acid hydroxyl monomer, polyol, organosilicon hydroxyl diol and hydroxyl-containing fluoride; and fully mixing the prepolymer A and the prepolymer B, and performing neutralization, emulsification, chain extension, vacuum pumping and solvent removal treatment to obtain the stain-resistant ultraviolet curing resin. According to the invention, the organic silicon long chain segment is introduced through the core-shell proportion design of the core-shell structure and the synthetic branching mode, so that the ultraviolet curing water-based dispersion has the self stain resistance, no additional additive or auxiliary agent or auxiliary component is needed, and the stain resistance effect of a solvent type product after coating is achieved on the premise of low VOC (volatile organic compound) emission through a physical mixing process.

Description

Method for preparing antifouling UV-curable resin using core-shell structure

technical field

The invention belongs to the field of resin preparation, and particularly relates to a method for preparing a pollution-resistant ultraviolet curing resin by utilizing a core-shell structure.

Background technique

At present, the coatings on the market for consumer electronics and plastic coatings with high performance, stain resistance and easy cleaning are still dominated by traditional solvent-based coatings, so VOC emissions cannot be overcome. However, most of the existing water-based anti-fouling systems still achieve anti-fouling effect through additives or other auxiliary means, and the durability and anti-fouling results are still different from those of solvent-based products.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method for preparing a stain-resistant UV-curable resin using a core-shell structure, and to provide at least the advantages that will be described later.

Another object of the present invention is to provide a method for preparing a fouling-resistant UV-curable resin by utilizing a core-shell structure. The UV-curable aqueous dispersion is prepared by introducing a long-chain organosilicon segment through the core-shell ratio design of the core-shell structure and a synthetic branching method. To achieve its own stain resistance, no additional additives or additives and auxiliary components are required to achieve lasting stain resistance; through the physical mixing process, under the premise of low VOC emissions, the stain resistance effect of solvent-based products after painting can be achieved .

The technical scheme of the present invention is as follows:

A method for preparing a stain-resistant UV-curable resin using a core-shell structure, comprising the following steps:

Isocyanate-terminated prepolymer is prepared by reacting organosilicon hydroxy diol, polyol, dihydroxy carboxylic acid and diisocyanate, and then high-functionality acrylic hydroxyl-containing monomer is used for end capping to obtain prepolymer A;

Prepolymer B with a slight excess of theoretical NCO was prepared by using diisocyanate and polyacrylic hydroxyl monomers, polyols, organosilicon hydroxyl diols, and hydroxyl-containing fluorides;

After the prepolymer A and the prepolymer B are fully mixed according to the mass ratio of 1:0.3~1, after neutralization, emulsification, chain extension and vacuum desolvation treatment, the antifouling ultraviolet curing resin is obtained.

Preferably, in the method for preparing a stain-resistant UV-curable resin using a core-shell structure, the prepolymer A is prepared by the following method:

Step 1, add 10-30 parts by weight of organosilicon hydroxy diol, 10-30 parts of diisocyanate monomer at room temperature and mix evenly, then add 0.01-0.1 part of catalyst, at 50- The isocyanate-terminated organosilicon prepolymer I was prepared by stirring and reacting in the range of 80 °C for 1-2 h;

In step 2, 3-8 parts by weight of dihydroxycarboxylic acid, 1-5 parts of small molecular polyol and butanone are mixed and added dropwise to the product of step 1, and the reaction is stirred in the range of 70-80 ° C. 1-3h, chain extension to obtain terminal isocyanate prepolymer II;

Step 3, mix by weight 20-30 parts of hydroxy acrylate monomer, 0.01-0.2 part of catalyst and 0.05-0.1 part of polymerization inhibitor, slowly add to step In the second product, the reaction is stirred in the range of 70-80° C. for 2-4 h to obtain a prepolymer A with both isocyanate and acrylic acid end caps.

Preferably, in the method for preparing a stain-resistant UV-curable resin using a core-shell structure, the prepolymer B is prepared by the following method:

Step 1: Add 0-20 parts by weight of organosilicon hydroxy diol, 0-5 parts of hydroxyl-containing fluoride, 10-30 parts of diisocyanate monomer at room temperature and mix evenly, 0-5 parts of small molecular polyvalent The alcohol is then added with 0.01-0.1 part of catalyst, and the isocyanate-terminated prepolymer I is prepared by stirring and reacting in the range of 80-100 ° C for 1-2 h;

In step 2, 30-70 parts by weight of polyacrylic acid hydroxyl monomer and 0.05-0.1 part of polymerization inhibitor are added to the product of step 1, and the reaction is stirred in the range of 70-80 ° C for 2-4 h to obtain the existing The isocyanate is in turn an acrylic terminated prepolymer B.

Preferably, in the method for preparing a stain-resistant UV-curable resin using a core-shell structure,

Mix prepolymer A, prepolymer B and acetone fully, then add 2-5 parts of amine salt neutralizer for neutralization, stir and react in the range of 50-70°C for 20min-30min, and then disperse at high speed Add deionized water for emulsification, and add polyamine to carry out secondary chain extension after sufficient emulsification to obtain a water-based UV-curable dispersion with silicone as the main chain. After emulsification, the final pH value is controlled within the range of 6 to 8;

Finally, at a temperature of 50-60° C., after 4-6 hours of vacuum desolvation, an aqueous UV-curable dispersion with a solvent-free organosilicon as the main chain can be obtained.

Preferably, in the method for preparing a stain-resistant UV-curable resin using a core-shell structure,

The organosilicon hydroxyl glycol is a carbon hydroxyl terminated glycol, wherein the metal salt content is less than 5PPM, and the molecular weight is one or more combinations of 1000, 2000 and 3000;

The hydroxyl-containing fluoride is hydroxyl-terminated perfluoroheptane and/or hydroxyl-terminated perfluorooctane;

The dihydroxycarboxylic acid is dihydroxypropionic acid and/or dihydroxybutyric acid;

The diisocyanate is one or more of toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate and hydrogenated diphenylmethane diisocyanate.

The polyol is one of 1,4 butanediol, trihydroxypropane, trimethylolethane, glycerol, polyester or polyether branched polyol;

The hydroxy acrylate monomer is pentaerythritol triacrylate and/or pentaerythritol diacrylate.

Preferably, in the method for preparing a stain-resistant UV-curable resin using a core-shell structure,

The catalyst is dibutyltin dilaurate and/or organic bismuth.

The polymerization inhibitor is one of p-hydroxyanisole, hydroquinone, 2-tert-butylhydroquinone, and 2,5-di-tert-butylhydroquinone;

Described neutralizing agent is triethylamine and/or dimethylethanolamine;

The polyamine is isophorone diamine and/or diethylene triamine.

The present invention includes at least the following beneficial effects:

1. Solving the existing high-performance antifouling products in consumer electronics and plastic coating has always been dominated by oil solvent-based systems, and those with too high VOC content can no longer meet the relevant national emission requirements.

2. At the same time, the anti-fouling group introduced into the resin and the resin are self-integrated and have good stability, which solves the problem that the existing water-based light-curing anti-fouling and easy-to-clean products add auxiliary components, which leads to complex manufacturing process and stability to be evaluated.

3. While providing low VOC, fast light curing and long-lasting stain resistance, users can adjust different gloss requirements through common matting agents, which solves the appearance limitation of product use-limited gloss.

Other advantages, objects, and features of the present invention will appear in part from the description that follows, and in part will be appreciated by those skilled in the art from the study and practice of the invention.

Detailed ways

The present invention will be further described in detail below, so that those skilled in the art can implement it with reference to the description.

It should be understood that terms such as "having", "comprising" and "including" as used herein do not assign the presence or addition of one or more other elements or combinations thereof.

The invention provides a preparation method of a core-shell structure easy-to-clean water-based UV-curable resin, comprising the following steps:

Prepolymer A: The isocyanate-terminated prepolymer is prepared by reacting organosilicon carbon hydroxy diol, polyol, dihydroxy carboxylic acid, and diisocyanate, and then high-functionality acrylic hydroxyl-containing monomer is used for end capping.

Prepolymer B: A prepolymer with a slight excess of theoretical NCO is prepared by using diisocyanate and polyacrylate hydroxyl-containing monomers, polyols, carbon hydroxyl organosilicon diols, and hydroxyl-containing fluorides.

Finally, with the aid of a co-solvent, the prepolymers A and B are fully mixed according to the mass ratio of 1:0.3~1, neutralized by ammonium salt reagent, emulsified, post-extended, and vacuumed to remove the solvent, and the main chain of organosilicon is prepared. (Fluorosilicone) aqueous UV-curable dispersion.

In an embodiment of the method for preparing a fouling-resistant UV-curable resin by utilizing a core-shell structure provided by the present invention, the prepolymer A is prepared by the following method:

Step 1, add 10-30 parts by weight of organosilicon hydroxy diol, 10-30 parts of diisocyanate monomer at room temperature and mix evenly, then add 0.01-0.1 part of catalyst, at 50- The isocyanate-terminated organosilicon prepolymer I was prepared by stirring and reacting in the range of 80 °C for 1-2 h;

In step 2, 3-8 parts by weight of dihydroxycarboxylic acid, 1-5 parts of small molecular polyol and butanone are mixed and added dropwise to the product of step 1, and the reaction is stirred in the range of 70-80 ° C. 1-3h, chain extension to obtain terminal isocyanate prepolymer II;

Step 3, mix by weight 20-30 parts of hydroxy acrylate monomer, 0.01-0.2 part of catalyst and 0.05-0.1 part of polymerization inhibitor, slowly add to step In the second product, the reaction is stirred in the range of 70-80° C. for 2-4 h to obtain a prepolymer A with both isocyanate and acrylic acid end caps.

In an embodiment of the method for preparing a fouling-resistant UV-curable resin using a core-shell structure provided by the present invention, the prepolymer B is prepared by the following method:

Step 1: Add 0-20 parts by weight of organosilicon hydroxy diol, 0-5 parts of hydroxyl-containing fluoride, 10-30 parts of diisocyanate monomer at room temperature and mix evenly, 0-5 parts of small molecular polyvalent The alcohol is then added with 0.01-0.1 part of catalyst, and the isocyanate-terminated prepolymer I is prepared by stirring and reacting in the range of 80-100 ° C for 1-2 h;

In step 2, 30-70 parts by weight of polyacrylic acid hydroxyl monomer and 0.05-0.1 part of polymerization inhibitor are added to the product of step 1, and the reaction is stirred in the range of 70-80 ° C for 2-4 h to obtain the existing The isocyanate is in turn an acrylic terminated prepolymer B.

In one embodiment of the method for preparing a fouling-resistant UV-curable resin by utilizing a core-shell structure provided by the present invention,

Mix prepolymer A, prepolymer B and acetone fully, then add 2-5 parts of amine salt neutralizer for neutralization, stir and react in the range of 50-70°C for 20min-30min, and then disperse at high speed Add deionized water for emulsification, and add polyamine to carry out secondary chain extension after sufficient emulsification to obtain a water-based UV-curable dispersion with silicone as the main chain. After emulsification, the final pH value is controlled within the range of 6 to 8;

Finally, at a temperature of 50-60° C., after 4-6 hours of vacuum desolvation, an aqueous UV-curable dispersion with a solvent-free organosilicon as the main chain can be obtained.

In one embodiment of the method for preparing a fouling-resistant UV-curable resin by utilizing a core-shell structure provided by the present invention,

The organosilicon hydroxyl glycol is a carbon hydroxyl terminated glycol, wherein the metal salt content is less than 5PPM, and the molecular weight is one or more combinations of 1000, 2000 and 3000;

The hydroxyl-containing fluoride is hydroxyl-terminated perfluoroheptane and/or hydroxyl-terminated perfluorooctane;

The dihydroxycarboxylic acid is dihydroxypropionic acid and/or dihydroxybutyric acid;

The diisocyanate is one or more of toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate and hydrogenated diphenylmethane diisocyanate.

The polyol is one of 1,4 butanediol, trihydroxypropane, trimethylolethane, glycerol, polyester or polyether branched polyol;

The hydroxy acrylate monomer is pentaerythritol triacrylate and/or pentaerythritol diacrylate.

In one embodiment of the method for preparing a fouling-resistant UV-curable resin by utilizing a core-shell structure provided by the present invention,

The catalyst is dibutyltin dilaurate and/or organic bismuth.

The polymerization inhibitor is one of p-hydroxyanisole, hydroquinone, 2-tert-butylhydroquinone, and 2,5-di-tert-butylhydroquinone;

Described neutralizing agent is triethylamine and/or dimethylethanolamine;

The polyamine is isophorone diamine and/or diethylene triamine.

The invention relates to the technical field of solvent-free polyurethane synthesis and aqueous polyurethane dispersion synthesis.

Example:

Preparation of Prepolymer A

Step 1, add 90 grams of 1000 molecular weight organosilicon hydroxydiol and 70 grams of diisocyanate monomer at room temperature to mix uniformly, then add 0.1 grams of dibutyltin dilaurate, and react at 65 ° C for 1 hour;

In step 2, 13.5 grams of dihydroxypropionic acid, 1 gram of trimethylolpropane and 40 grams of butanone were mixed and added dropwise to the product of step 1, and the reaction was stirred at 80 ° C for 3 hours. Isocyanate Prepolymer II;

Step 3, mix 80 grams of pentaerythritol triacrylate monomer, 0.1 grams of dibutyltin dilaurate catalyst and 0.3 grams of p-hydroxyanisole, slowly add to the product of step 2, at 75 ° C The reaction was stirred within the range for 2.5 hours to obtain a prepolymer A with both isocyanate and acrylic end caps.

Preparation of Prepolymer B:

Step 1, add 55 grams of 1000 molecular weight organosilicon hydroxydiol, 4.5 grams of dodecafluoroheptanol-containing fluoride, 30 grams of diisocyanate monomer at room temperature, and mix uniformly, 0.1 grams of dibutyltin dilaurate catalyst, in The isocyanate prepolymer I was stirred and reacted in the range of 90°C for 2 hours;

In step 2, 65 g of pentaerythritol triacrylate monomer and 0.05 g of p-hydroxyanisole are added to the product of step 1, and the reaction is stirred for 2 hours in the scope of 75 ° C to obtain both isocyanate and acrylic acid-terminated prepolymerization. thing B.

Mix prepolymer A, prepolymer B and 110 grams of acetone thoroughly, then add 10.5 grams of triethylamine, and neutralize at 50 degrees for 30 minutes.

Then add 650 grams of deionized water to emulsify under high-speed dispersion, and fully emulsify. Add 20 grams of isophorone diamine diluted to 20% in high-speed stirring for secondary chain extension, continue neutralization for 30 minutes, and the chain extension temperature can be in the range of about 40-50 degrees.

Finally, at a temperature of 60° C., after 4-6 hours of vacuum desolvation, an aqueous UV-curable dispersion with solvent-free silicone as the main chain can be obtained.

Basic template preparation:

1) Add 3% DPM co-solvent to the emulsion under stirring, and then add 3% 1173/184 (1/1) mixed initiator; after stirring, add 0.2% Deqian 699 associative thickener to obtain Coating preparations.

2) Coating on ABS/PC plastic substrate with 30um wire rod. After flashing for about 3 minutes, put it into a 60-degree oven for 10 minutes, and then cure it with a mercury lamp. The curing energy is 800mj/cm ² .

Through the water drop angle test observation, the expected water drop angle can reach 105°.

The present invention has the following characteristics:

1) The selection of silicone raw materials that can be used in the polyurethane system is carried out, and it is directly synthesized into the chain segment of the dispersion shell, and the best anti-fouling effect and dispersion stability are achieved through chain extension and branching.

2) Using the design method of the core-shell structure, the core structure can be made into the same high-performance UV-curable resin as the solvent-free system as a thick film-forming skeleton. In this way, the core-shell principle is used to maximize the performance of the traditional solvent-based anti-fouling UV-curable resin.

3) The anti-fouling use of the present invention is based on light curing and water-based. It avoids the high VOC volatilization of solvent-based light-curing coatings, and at the same time, it has a shorter curing time and lower energy consumption than water-based thermal curing coatings.

4) The introduction of anti-fouling components has been completed in the main body. In the process of preparing the coating, the process is simplified as much as possible, and only the basic materials are added to achieve the anti-fouling effect after coating and curing.

5) The product formula is simple and stable, the gloss can be adjusted by ordinary matting powder without affecting the anti-fouling effect, and the practicability is wide.

Compared with other water-based light-curing and anti-fouling technologies, the method provided by the present invention is that the main film-forming substance has its own anti-fouling property, as follows:

1) The anti-fouling effect is close to the current oily products of the same type. The water contact angle of the full-light system can reach 105°; the water contact angle of the semi-light system can reach 100°.

2) The aging time is longer than that of externally added anti-fouling ingredients. Referring to GB/T 2423.3-2006, after 24 hours of testing, the marker pen can still maintain the easy-to-clean effect in full light state.

3) The front-end synthesis process route is relatively mature, and the quality and stability of product batches are well controlled.

4) The back-end preparation process is simple, and it can simply mix and prepare antifouling products with different glosses according to different needs, and the large-scale production efficiency is high.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the application listed in the description and the embodiment, and it can be applied to various fields suitable for the present invention. For those skilled in the art, it can be easily Therefore, the invention is not limited to the specific details without departing from the general concept defined by the appended claims and the scope of equivalents.

Claims (6)

1. The method for preparing the stain-resistant ultraviolet curing resin by utilizing the core-shell structure is characterized by comprising the following steps of:

preparing an isocyanate end group prepolymer by reacting organic silicon hydroxyl dihydric alcohol, polyalcohol, dihydroxy carboxylic acid and diisocyanate, and then carrying out end capping by adopting a high-functionality acrylic acid hydroxyl-containing monomer to prepare a prepolymer A;

preparing a prepolymer B with a theoretical NCO micro-excess by diisocyanate, a polyacrylic acid hydroxyl monomer, polyol, organosilicon hydroxyl diol and fluoride containing hydroxyl;

and (3) mixing prepolymer A and prepolymer B according to a mass ratio of 1: and 0.3-1, fully mixing, and performing neutralization, emulsification, chain extension and vacuum-pumping solvent removal treatment to obtain the stain-resistant ultraviolet curing resin.

2. The method for preparing the stain resistant uv curable resin using the core-shell structure according to claim 1, wherein the prepolymer a is prepared by the following method:

step one, adding 10-30 parts by weight of organic silicon hydroxyl dihydric alcohol and 10-30 parts by weight of diisocyanate monomer at normal temperature, uniformly mixing, then adding 0.01-0.1 part of catalyst, and stirring and reacting at 50-80 ℃ for 1-2 hours to obtain isocyanate-terminated organic silicon prepolymer I;

step two, uniformly mixing 3-8 parts by weight of dihydroxy carboxylic acid, 1-5 parts by weight of micromolecular polyol and butanone, dropwise adding the mixture into the product obtained in the step one, stirring and reacting for 1-3 hours at the temperature of 70-80 ℃, and carrying out chain extension to obtain an isocyanate-terminated prepolymer II;

and step three, uniformly mixing 20-30 parts by weight of hydroxyl acrylate monomer, 0.01-0.2 part by weight of catalyst and 0.05-0.1 part by weight of polymerization inhibitor, slowly adding the mixture into the product obtained in the step two, and stirring and reacting for 2-4 hours at the temperature of 70-80 ℃ to obtain prepolymer A which is not only blocked by isocyanate but also blocked by acrylic acid.

3. The method for preparing the stain resistant uv curable resin using the core-shell structure according to claim 2, wherein the prepolymer B is prepared by the following method:

firstly, adding 0-20 parts by weight of organic silicon hydroxyl dihydric alcohol, 0-5 parts by weight of hydroxyl-containing fluoride and 10-30 parts by weight of diisocyanate monomer at normal temperature, uniformly mixing, adding 0-5 parts by weight of micromolecular polyalcohol and then 0.01-0.1 part by weight of catalyst, and stirring and reacting at the temperature of 80-100 ℃ for 1-2 hours to prepare an isocyanate-terminated prepolymer I;

and step two, adding 30-70 parts by weight of polyacrylic acid hydroxyl monomer and 0.05-0.1 part by weight of polymerization inhibitor into the product obtained in the step one, and stirring and reacting for 2-4h at the temperature of 70-80 ℃ to obtain prepolymer B which is not only isocyanate but also acrylic acid terminated.

4. The method for preparing a stain resistant UV curable resin using a core-shell structure according to claim 3,

fully mixing the prepolymer A, the prepolymer B and acetone, adding 2-5 parts of an amine salt neutralizing agent for neutralization, stirring and reacting at 50-70 ℃ for 20-30 min, then adding deionized water for emulsification under the condition of high-speed dispersion, adding polyamine for secondary chain extension after full emulsification to obtain an aqueous ultraviolet curing dispersion with organic silicon as a main chain, and controlling the final pH value within 6-8 after emulsification;

finally, at the temperature of 50-60 ℃, vacuumizing for 4-6 hours to remove the solvent, and obtaining the water-based ultraviolet curing dispersoid taking the solvent-free organic silicon as the main chain.

5. The method for preparing a stain resistant UV curable resin using a core-shell structure according to claim 4,

the organic silicon hydroxyl dihydric alcohol is dihydric alcohol terminated by carbon hydroxyl, wherein the content of metal salt is less than 5PPM, and the molecular weight is one or more of 1000, 2000 and 3000;

the fluoride containing hydroxyl is hydroxyl-terminated perfluoroheptane and/or hydroxyl-terminated perfluorooctane;

the dihydroxy carboxylic acid is dihydroxy propionic acid and/or dihydroxy butyric acid;

the diisocyanate is one or more of toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate and hydrogenated diphenylmethane diisocyanate.

The polyhydric alcohol is one of 1, 4 butanediol, trihydroxypropane, trimethylolethane, glycerol, polyester or polyether branched polyhydric alcohol;

the hydroxyl acrylate monomer is pentaerythritol triacrylate and/or pentaerythritol diacrylate.

6. The method for preparing a stain resistant UV curable resin using a core-shell structure according to claim 5,

the catalyst is dibutyl tin dilaurate and/or organic bismuth.

The polymerization inhibitor is one of p-hydroxyanisole, hydroquinone, 2-tert-butylhydroquinone and 2, 5-di-tert-butylhydroquinone;

the neutralizing agent is triethylamine and/or dimethylethanolamine;

the polyamine is isophorone diamine and/or diethylenetriamine.