CN115558060A - Polyurethane acrylate adhesive and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of adhesives, and in particular relates to a polyurethane acrylate adhesive and a preparation method thereof. The adhesive uses polyurethane as the main chain and graft copolymerized modified acrylate, and the adhesive contains hydrophilic The functional monomer DMPA, the functional monomer HEMA and the modified organosilicon unit, and the modified organosilicon unit introduces a silicon side chain on the carbon chain to form a graft, block or interpenetrating network system; and provides Specific preparation method. The invention solves the defects of existing polyurethane adhesives and acrylate adhesives, uses the excellent performance of water-based polyurethane to modify the acrylate emulsion polymer, and the obtained emulsion has excellent printing performance, which not only effectively reduces the adhesion The production cost of the adhesive, and the ability to combine the properties of the two adhesives at the same time, has great value for the research of this type of adhesive.

Description

A kind of polyurethane acrylate adhesive and preparation method thereof

technical field

The invention belongs to the field of adhesives, in particular to a polyurethane acrylate adhesive and a preparation method thereof.

Background technique

Pigment printing is a process that attaches pigment particles that have no affinity and reactivity to fibers to the surface of fibers through a binder, thereby imparting colors and patterns to fibers. At present, there are many types of pigment printing adhesives commonly used in China, including: polyacrylate adhesives, polyurethane adhesives, butadiene adhesives, vinyl acetate adhesives, etc. Water-based polyurethane has good flexibility and low temperature resistance. Strong adhesion and other characteristics, but the water-based polyurethane adhesive dries slowly during use and has poor wettability. During use, if moisture is still in the coating and is suddenly heated and dried, the formed film will have poor crosslinkability. The use of water-based polyurethane in fabrics can endow the fabric with excellent wear resistance, resilience, antistatic, washable, fullness, smoothness and moisture permeability, etc., but the fabric feels hard, and the cost of water-based polyurethane as an adhesive higher. Acrylic adhesives have received great attention since then due to their many advantages, such as high bonding performance, fast curing speed, wide adaptability, excellent mechanical properties, and no selectivity to bonding objects. Many defects are also exposed, such as sticky film, poor water resistance and temperature resistance, poor moisture permeability and air permeability, low temperature film forming property, poor anti-back tack at high temperature, relatively low elongation, etc.

Contents of the invention

Aiming at the problems in the prior art, the present invention provides a polyurethane acrylate adhesive, which solves the defects of the existing polyurethane adhesive and acrylate adhesive, and utilizes the excellent performance of water-based polyurethane to carry out acrylate emulsion polymer Modification, the obtained emulsion has excellent printing performance, not only effectively reduces the production cost of the adhesive, but also can combine the properties of the two adhesives at the same time, which is of great value for the research of this type of adhesive .

For realizing above technical purpose, technical scheme of the present invention is:

A polyurethane acrylate adhesive, the adhesive is based on polyurethane and graft copolymerized modified acrylate, and the adhesive contains hydrophilic monomer DMPA, functional monomer HEMA and modified organic silicon unit.

The modified organosilicon unit introduces silicon side chains on the carbon chain to form a graft, block or interpenetrating network system.

The polyurethane is a vinyl-terminated polyurethane emulsion containing double bonds.

The acrylate is based on MMA and AN as hard monomers, butyl acrylate and ethyl acrylate as soft monomers, and hydroxyethyl acrylate as functional monomers. The mass ratio of described hard monomer and soft monomer is 1:1

The polyurethane main chain is polymerized from polyhydric alcohol, isocyanate compound, DMPA and functional monomer HEMA. The molar ratio of the isocyanate-based compound to the polyol is 4:1-1.2.

The polyol is composed of castor oil and polytetrahydrofuran, and the castor oil accounts for 10% of the mass of the polyol.

The reactive functional groups of the isocyanate are hydroxyl, primary amino and combinations thereof.

The organosilicon unit is formed by modifying the terminal vinyl group chain extension with organosilicon, hydrazine hydrate and diethylenetriamine.

The preparation of described adhesive comprises the steps:

Step 1, synthesis of polyurethane emulsion: a1, react PTMG, TMP, NPG, castor oil, and IPDI in a three-necked flask at 80°C to form a prepolymer, and cool down to 70°C after reaching the end of the reaction; a2 , will add hydrophilic chain extender DMPA, solvent NMP and a small amount of catalyst DBTDL, keep warm at 70°C until the mole fraction of isocyanate reaches the calculated theoretical value, add acrylic acid functional monomer HEMA; a3, after the reaction is complete Use a small amount of butyl acrylate to replace part of the solvent MEK to reduce the viscosity of the polyurethane prepolymer, and lower the temperature to 40°C; a4, add TEA and DMPA equimolar as a salt-forming agent for the salt-forming reaction, and the molecule is synthesized after 5 minutes of reaction The prepolymer of vinyl-terminated polyurethane containing double bonds in the chain; a5, add jelly water and adjust the stirring speed, disperse the prepolymer into distilled water under high-speed stirring, and then slowly add silicone/hydrazine hydrate/diethylene Triamine (DETA) composite chain extender, and low-speed stirring for 1-2h, to obtain modified vinyl-terminated polyurethane emulsion; wherein the addition of HEMA is 3% of the total solid content;

Step 2, the synthesis of polyurethane graft copolymerization modified acrylic copolymer emulsion: b1, methyl methacrylate, acrylonitrile, butyl acrylate, ethyl acrylate and modified vinyl-terminated polyurethane emulsion are put into a three-necked flask, and Emulsify for about 40 minutes under the condition of N2. On the one hand, the PU can fully wrap the monomer. On the one hand, the oxygen that has a polymerization inhibitory effect in the three-necked flask and the reaction solution can be removed. On the other hand, the emulsifier can be fully dissolved in the reaction solution. It can also mix various acrylic monomers uniformly; then slowly raise the temperature to 65°C, add the initiator dropwise into the three-necked flask, drop it within 1.5h, then raise the temperature to 75°C, keep the temperature for 2h, and obtain the PUA original emulsion. That is polyurethane acrylate adhesive.

As can be seen from the above description, the present invention has the following advantages:

1. The present invention solves the defects of existing acrylate adhesives and polyurethane adhesives, and provides a kind of graft copolymerization modified acrylate with polyurethane as the main chain, containing hydrophilic monomer DMPA, functional unit Bulk HEMA and modified silicone units. Among them, organosilicon introduces silicon side chains on the carbon chain to form a graft, block or interpenetrating network system.

2. The present invention uses the excellent performance of water-based polyurethane to modify the acrylate emulsion polymer, and the obtained emulsion has excellent printing performance, which not only effectively reduces the production cost of the adhesive, but also can simultaneously combine the two adhesives. The combination of properties has great value for the study of this type of adhesive.

3. The binder provided by the present invention has improved thermal properties, and the compatibility of particles has also been improved.

Description of drawings

Fig. 1 is the transmission electron micrograph of the PUA protoemulsion of embodiment 1 and its printed electron micrograph.

detailed description

A specific embodiment of the present invention will be described in detail with reference to FIG. 1 , but the claims of the present invention are not limited in any way.

Example 1

Pretreated isophorone diisocyanate (IPDI), polytetrahydrofuran glycol (PTMG), neopentyl glycol (NPG) and trimethylolpropane (TMP) in a mass ratio of 11:4:7:2 Add the ratio of 10% castor oil and 2‰ catalyst dibutyltin dilaurate (DBTDL) to the three-necked flask, and slowly heat up to 80°C. After reaching the end point, the temperature was lowered to 70°C. Then add 1.2g of hydrophilic chain extender dimethylolpropionic acid (DMPA), 0.6g of solvent N-methylpyrrolidone (NMP) and 0.6g of hydroxyethyl methacrylate (HEMA) to the flask. After the reaction was carried out under heat preservation until the mole fraction of isocyanate groups reached the calculated theoretical value, 0.15 g of ethyl ketone (MEK) was added to reduce the viscosity of the polyurethane prepolymer, and the temperature was lowered to 40°C. Add triethylamine (TEA) equimolar with DMPA as a salt-forming agent for the salt-forming reaction. Add 100 g of distilled water and adjust the stirring speed, and stir and disperse the prepared prepolymer with hydrophilic polyurethane into the distilled water at 1000 r/min. Adjust the stirring speed, slowly add 3g of organosilicon/hydrazine hydrate/diethylenetriamine (DETA) composite chain extender, stir at 100r/min for 1 to 2 hours, and obtain vinyl-terminated polyurethane emulsion for modification. Take 8g of methyl methacrylate, 2g of acrylonitrile and 2g of butyl acrylate. Ethyl acrylate and 10 g of vinyl-terminated-PU for modification prepared by in-situ emulsion polymerization were placed in a three-necked flask, and emulsified for about 40 minutes under the condition of flowing N2. Then slowly raise the temperature to 65°C, add 0.6% initiator AIBN dropwise into the three-necked flask, finish dropping within 1.5h, then raise the temperature to 75°C, keep the temperature for 2h, and obtain the copolymerized PUA original emulsion. The transmission electron micrograph of the product and its printed electron micrograph are shown in Figure 1.

Example 2

According to Example 1, first react PTMG, TMP, NPG, castor oil, and IPDI in a three-necked flask at 80° C. to form a prepolymer. After reaching the end point of the reaction, the temperature was lowered to 70°C. Add 0.12g of hydrophilic chain extender DMPA, 0.6g of solvent NMP, calculated amount of HEMA and a small amount of catalyst DBTDL, keep warm at 70°C until the mole fraction of isocyanate reaches the calculated theoretical value, add 0.15g of MEK Reduce the viscosity of the prepolymer and lower the temperature to 40°C. Add TEA and DMPA equimolar as a salt-forming agent for the salt-forming reaction, and react for 5 minutes to synthesize a prepolymer of vinyl-terminated polyurethane containing double bonds in the molecular chain. Add 100 g of distilled water and adjust the stirring speed, and disperse the prepared prepolymer with hydrophilic polyurethane into the distilled water under stirring at 1000 r/min. Adjust the stirring speed, slowly add 3g of organosilicon/hydrazine hydrate/diethylenetriamine (DETA) composite chain extender, stir at 100r/min for 1 to 2 hours, and obtain vinyl-terminated polyurethane emulsion for modification. Take 8g of methyl methacrylate, 2g of acrylonitrile and 2g of butyl acrylate. Ethyl acrylate and 10 g of vinyl-terminated-PU for modification prepared by in-situ emulsion polymerization were placed in a three-necked flask, and emulsified for about 40 minutes under the condition of flowing N2. Then slowly raise the temperature to 65°C, add 0.6% initiator AIBN dropwise into the three-necked flask, finish dropping within 1.5h, then raise the temperature to 75°C, keep the temperature for 2h, and obtain the copolymerized PUA original emulsion.

Example 3

First react PTMG, TMP, NPG, castor oil, and IPDI in a three-necked flask at 80°C to form a prepolymer. After reaching the end point of the reaction, the temperature was lowered to 70°C. Then add 1.2g of hydrophilic chain extender DMPA, 0.6g of solvent NMP and a small amount of catalyst DBTDL, keep warm at 70°C until the mole fraction of isocyanate reaches the calculated theoretical value, add 0.6g of acrylic acid functional monomer Body HEMA. After the reaction is completed, a small amount of butyl acrylate is used to replace part of the solvent MEK to reduce the viscosity of the polyurethane prepolymer, and the temperature is lowered to 40°C. Add TEA and DMPA equimolar as a salt-forming agent for the salt-forming reaction, and react for 5 minutes to synthesize a prepolymer of vinyl-terminated polyurethane containing double bonds in the molecular chain. Add 100 g of distilled water and increase the stirring speed, and disperse the prepared prepolymer with hydrophilic polyurethane into the distilled water under stirring at 1000 r/min. Reduce the stirring speed, slowly add 3g of organosilicon/hydrazine hydrate/diethylenetriamine (DETA) composite chain extender, stir at low speed for 1 to 2 hours, and obtain vinyl-terminated polyurethane emulsion for modification. Take 8g of methyl methacrylate, 2g of propylene and 2g of butyl acrylate. Ethyl acrylate and a certain amount of modified vinyl-PU prepared by in-situ emulsion polymerization were placed in a three-necked flask, and emulsified for about 40 minutes under the condition of flowing N2. Then slowly raise the temperature to 65°C, add 0.6% initiator AIBN dropwise into the three-necked flask, finish dropping within 1.5h, then raise the temperature to 75°C, keep the temperature for 2h, and obtain the copolymerized PUA original emulsion.

comparative example

First, 4 g of PTMG, 2 g of TMP, and 7 g of NPG were reacted in a three-necked flask at 80° C. to form a prepolymer. After reaching the end point of the reaction, the temperature was lowered to 70°C. Then add 1.2g of hydrophilic chain extender dimethylolpropionic acid (DMPA), 0.6g of solvent N-methylpyrrolidone (NMP) and 0.6g of hydroxyethyl methacrylate (HEMA) to the flask. After the reaction was carried out under heat preservation until the mole fraction of isocyanate groups reached the calculated theoretical value, 0.15 g of ethyl ketone (MEK) was added to reduce the viscosity of the polyurethane prepolymer, and the temperature was lowered to 40°C. Add triethylamine (TEA) equimolar with DMPA as a salt-forming agent for the salt-forming reaction. Add 100 g of distilled water and adjust the stirring speed, and stir and disperse the prepared prepolymer with hydrophilic polyurethane into the distilled water at 1000 r/min. 8 g of methyl methacrylate, 2 g of acrylonitrile and 2 g of butyl acrylate. Ethyl acrylate and a certain amount of vinyl-PU prepared by in-situ emulsion polymerization were placed in a three-necked flask, and emulsified for about 40 minutes under the condition of flowing N2. Then slowly raise the temperature to 65°C, add 0.6% initiator AIBN dropwise into the three-necked flask, finish dropping within 1.5h, then raise the temperature to 75°C, keep the temperature for 2h, and obtain the copolymerized PUA original emulsion.

Carry out performance test with the product of embodiment 1-3 and the product of comparative example 1, situation is as follows:

It can be seen from the table that the water-based polyurethane modified acrylate copolymer can improve the compatibility of the two components, give full play to the advantages of the two components, and improve their comprehensive performance. The synthesized emulsion has undergone graft copolymerization, the particle size is slightly thicker than PU, but the distribution is narrow, the thermal stability of PUA is greatly improved, and the compatibility of the particles is very good.

It can be understood that the above specific descriptions of the present invention are only used to illustrate the present invention and are not limited to the technical solutions described in the embodiments of the present invention. Those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced to achieve the same technical effect; as long as the use requirements are met, all are within the protection scope of the present invention.

Claims (10)

1. A polyurethane acrylate adhesive, characterized in that: the adhesive uses polyurethane as the main chain and graft copolymerized modified acrylate, and the adhesive contains hydrophilic monomer DMPA, functional unit Bulk HEMA and modified silicone units. 2. The polyurethane acrylate adhesive according to claim 1, characterized in that: the modified silicone unit introduces silicon side chains on the carbon chain to form a graft, block or interpenetrating network system. 3. The polyurethane acrylate adhesive according to claim 1, characterized in that: the polyurethane is a vinyl-terminated polyurethane emulsion containing double bonds. 4. The polyurethane acrylate adhesive according to claim 1, characterized in that: the acrylate is based on MMA and AN as hard monomers, butyl acrylate and ethyl acrylate as soft monomers, and acrylate hydroxy Ethyl esters as functional monomers. 5. The polyurethane acrylate adhesive according to claim 4, characterized in that: the mass ratio of the hard monomer to the soft monomer is 1:1. 6. The polyurethane acrylate adhesive according to claim 1, characterized in that: the polyurethane main chain is polymerized by polyhydric alcohol, isocyanate-based compound, DMPA and functional monomer HEMA, and the isocyanate-based compound and polyvalent The molar ratio of alcohol is 4:1-1.2. 7. The polyurethane acrylate adhesive according to claim 6, characterized in that: the polyol is composed of castor oil and polytetrahydrofuran, and the castor oil accounts for 10% of the mass of the polyol. 8. The polyurethane acrylate adhesive according to claim 6, characterized in that: the reactive functional groups of the isocyanate are hydroxyl groups, primary amino groups and combinations thereof. 9. The polyurethane acrylate adhesive according to claim 1, characterized in that: the organosilicon unit is formed by modifying the chain extension of terminal vinyl groups with organosilicon, hydrazine hydrate and diethylenetriamine. 10. polyurethane acrylate adhesive according to claim 1, is characterized in that: the preparation of described adhesive comprises the steps: Step 1, synthesis of polyurethane emulsion: a1, react PTMG, TMP, NPG, castor oil, and IPDI in a three-necked flask at 80°C to form a prepolymer, and cool down to 70°C after reaching the end of the reaction; a2, Add hydrophilic chain extender DMPA, solvent NMP and a small amount of catalyst DBTDL, keep warm at 70°C until the mole fraction of isocyanate reaches the calculated theoretical value, add acrylic acid functional monomer HEMA; a3, after the reaction is complete, use A small amount of butyl acrylate is used to replace part of the solvent MEK to reduce the viscosity of the polyurethane prepolymer, and the temperature is lowered to 40°C; a4, add TEA and DMPA equimolar as a salt-forming agent for the salt-forming reaction, and the molecular chain is synthesized after 5 minutes of reaction The prepolymer of vinyl-terminated polyurethane containing double bonds; a5, add jelly water and adjust the stirring speed, disperse the prepolymer into distilled water under high-speed stirring, and then slowly add silicone/hydrazine hydrate/diethylenetri Amine (DETA) composite chain extender, and low-speed stirring for 1-2h, to obtain modified vinyl-terminated polyurethane emulsion; wherein the addition of HEMA is 3% of the total solid content; Step 2, the synthesis of polyurethane graft copolymerization modified acrylic copolymer emulsion: b1, methyl methacrylate, acrylonitrile, butyl acrylate, ethyl acrylate and modified vinyl-terminated polyurethane emulsion are put into a three-necked flask, and Emulsify for about 40 minutes under the condition of N2. On the one hand, the PU can fully wrap the monomer. On the one hand, the oxygen that has a polymerization inhibitory effect in the three-necked flask and the reaction solution can be removed. On the other hand, the emulsifier can be fully dissolved in the reaction solution. It can also mix various acrylic monomers uniformly; then slowly raise the temperature to 65°C, add the initiator dropwise into the three-necked flask, drop it within 1.5h, then raise the temperature to 75°C, keep the temperature for 2h, and obtain the PUA original emulsion. That is polyurethane acrylate adhesive.

Images