High-temperature-resistant and high-elongation polyurethane acrylic resin and application thereof in preparation of ultraviolet-cured peelable glue
阅读说明：本技术 一种耐高温、高伸长率聚氨酯丙烯酸树脂及其在制备紫外光固化可剥胶中的应用 (High-temperature-resistant and high-elongation polyurethane acrylic resin and application thereof in preparation of ultraviolet-cured peelable glue ) 是由 姚永平 谭祺才 梁永勇 谭海剑 于 2021-09-07 设计创作，主要内容包括：本发明公开了一种耐高温、高伸长率聚氨酯丙烯酸树脂及其在制备紫外光固化可剥胶中的应用。该聚氨酯丙烯酸树脂的制备方法,包括如下步骤：(1)将二异氰酸酯、二月桂酸二丁基锡依次加入到丙烯酸异冰片酯中,滴加聚烯烃多元醇进行反应得到半加成物1；(2)将二羟甲基丁酸加入半加成物1中进行反应得到中间产物2；(3)将丙烯酸羟基酯、阻聚剂依次加入到半加成物2中继续进行反应,得到中间产物3；(4)将环氧树脂、催化剂依次加入到中间产物3中进行反应,得到聚氨酯丙烯酸酯树脂。本发明提出的紫外光固化可剥胶含聚氨酯丙烯酸酯树脂,具有优异的耐热性、伸长率,应用于透明导电玻璃、薄膜的ITO镀膜、电路板及其他器件临时粘接保护。(The invention discloses a high-temperature-resistant high-elongation polyurethane acrylic resin and application thereof in preparation of ultraviolet-cured peelable glue. The preparation method of the polyurethane acrylic resin comprises the following steps: (1) sequentially adding diisocyanate and dibutyltin dilaurate into isobornyl acrylate, and dropwise adding polyolefin polyol for reaction to obtain a semi-adduct 1; (2) adding dimethylolbutyric acid into the semi-adduct 1 to react to obtain an intermediate product 2; (3) sequentially adding hydroxyl acrylate and a polymerization inhibitor into the semi-adduct 2 for continuous reaction to obtain an intermediate product 3; (4) and adding the epoxy resin and the catalyst into the intermediate product 3 in sequence for reaction to obtain the urethane acrylate resin. The ultraviolet-curing peelable glue containing polyurethane acrylate resin provided by the invention has excellent heat resistance and elongation, and is applied to temporary bonding protection of transparent conductive glass, ITO (indium tin oxide) coating of films, circuit boards and other devices.)
1. A preparation method of high-temperature-resistant and high-elongation polyurethane acrylic resin is characterized by comprising the following steps:
(1) sequentially adding diisocyanate and dibutyltin dilaurate into isobornyl acrylate, then dropwise adding polyolefin polyol, keeping the temperature of 50-70 ℃ for reaction, monitoring the content of-NCO groups in the isobornyl acrylate to be 50-55% of the initial content before reaction, and finishing the reaction to obtain a semi-adduct 1 of the diisocyanate and the polyolefin polyol;
(2) adding dimethylolbutyric acid into the semi-adduct 1, keeping the temperature of 50-70 ℃ for reaction, and finishing the reaction when the-NCO group content in isobornyl acrylate is monitored to reach a theoretical value to obtain a carboxyl-containing intermediate product 2;
(3) sequentially adding hydroxyl acrylate and a polymerization inhibitor into the carboxyl-containing semi-adduct 2, heating to the temperature of 50-70 ℃ for continuous reaction, and finishing the reaction when the content of-NCO groups in isobornyl acrylate is monitored to be 0 to obtain an intermediate product 3 containing carboxyl and acryloyloxy;
(4) and (3) sequentially adding epoxy resin and a catalyst into the intermediate product 3, heating to 80-110 ℃ for reaction, and finishing the reaction when the acid value of a reaction system is monitored to be less than or equal to 1mgKOH/g to obtain the high-temperature-resistant and high-elongation polyurethane acrylate resin.
2. The method for preparing the high temperature resistant and high elongation polyurethane acrylic resin according to claim 1, wherein the molar ratio of the polyolefin polyol to the diisocyanate in the step (1) is (0.2-0.5): 1; the mass ratio of the diisocyanate to the dibutyltin dilaurate is 100: (0.1-1); the mass ratio of the diisocyanate to the isobornyl acrylate is 1 (0.5-1).
3. The method for preparing the high temperature resistant and high elongation polyurethane acrylic resin according to claim 1, wherein the diisocyanate in the step (1) is one or more selected from the group consisting of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate; the polyolefin polyol is selected from one of hydroxyl-terminated polybutadiene, hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated polybutadiene-acrylonitrile, hydroxyl-terminated styrene-butadiene liquid rubber, hydroxyl-terminated polyisoprene, hydroxyl-terminated hydrogenated polyisoprene and polystyrene polyol.
4. The method for preparing the high temperature resistant and high elongation polyurethane acrylic resin according to claim 1, wherein the molar ratio of dimethylolbutyric acid to diisocyanate in the step (2) is (0.1-0.3): 1.
5. The method for preparing the high temperature resistant and high elongation polyurethane acrylic resin according to claim 1, wherein the molar ratio of the hydroxyl acrylate to the diisocyanate in the step (3) is (0.4-1.6):1, and the mass ratio of the hydroxyl acrylate to the polymerization inhibitor is 100: (0.1-1).
6. The method for preparing high temperature resistant, high elongation urethane acrylic resin according to claim 1, wherein the hydroxy acrylate in step (3) is one or more selected from the group consisting of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and pentaerythritol triacrylate; the polymerization inhibitor is selected from more than one of p-methoxyphenol, hydroquinone, 2, 5-dimethyl hydroquinone, 2, 6-di-tert-butyl-p-cresol and 2,2,6, 6-tetramethyl piperidine-nitroxide free radical.
7. The preparation method of the high temperature resistant and high elongation polyurethane acrylic resin according to claim 1, wherein the mass ratio of the epoxy resin to the catalyst in the step (4) is 100 (0.1-1); the molar ratio of epoxy groups of the epoxy resin to dimethylolbutyric acid is 1: 1; the epoxy resin is selected from more than one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac epoxy resin and o-cresol novolac epoxy resin; the catalyst is selected from more than one of N, N-dimethylbenzylamine, N-dimethylaniline, DMP-30, triethylamine, trimethyl benzyl ammonium chloride, triphenyl phosphine, triphenyl stibium, tetraethyl ammonium bromide and chromium acetylacetonate.
8. The high-temperature-resistant high-elongation polyurethane acrylic resin prepared by the preparation method of claim 1.
9. The use of the high temperature resistant, high elongation polyurethane acrylic resin of claim 8 in the preparation of ultraviolet light curable peelable glue.
10. The ultraviolet curing peelable glue is characterized by comprising the following components in parts by mass: 30-50 parts of polyurethane acrylic resin as described in claim 8, 1-5 parts of photoinitiator, 10-30 parts of reactive diluent, 2-10 parts of fumed silica and 1-3 parts of organosilicon defoamer.
Technical Field
The invention relates to the technical field of photocuring peelable glue resin, in particular to high-temperature-resistant high-elongation polyurethane acrylic resin and application thereof in preparation of ultraviolet-curing peelable glue.
Background
The peelable glue is mainly applied to temporary bonding protection of transparent conductive glass in a touch screen, ITO (indium tin oxide) coating of a film, a circuit board and other device materials, and plays roles in insulation, moisture prevention and protection. The method can be applied to logo protection, specific part process protection, scratch prevention and the like, and the application materials mainly comprise glass, PCB (printed Circuit Board), metal and the like. The ultraviolet light curing peelable glue has the characteristics of good flexibility, easy peeling and continuous glue breaking; low water vapor permeability; ultraviolet light curing and no solvent; no corrosiveness and moisture resistance; the binding force is good, peeling and falling are avoided, and the repairing can be carried out; the stripping is easy and complete, no residue is left, and no influence is caused on the bottom layer. The existing ultraviolet light curing peelable glue has the defects of brittleness and easy breakage after being baked at high temperature.
Disclosure of Invention
The invention solves the problems in the prior art, and aims to provide the high-temperature-resistant and high-elongation polyurethane acrylate resin and the application thereof in preparing the ultraviolet curing peelable glue, wherein the elongation is increased by using polyolefin polyol as a soft segment; chain extension is carried out through dimethylolbutyric acid, the molecular weight is increased, the elongation is further improved, and carboxyl is introduced; epoxy resin is introduced through the reaction of carboxyl in dimethylolbutyric acid and epoxy resin epoxy group, so that the heat resistance of the whole resin is improved, and the problems that ultraviolet curing peelable glue has poor high-temperature resistance and is easy to become brittle and break after being baked at high temperature are solved.
In order to achieve the purpose, the invention adopts the technical scheme that: a preparation method of high-temperature-resistant and high-elongation polyurethane acrylic resin comprises the following steps:
(1) sequentially adding diisocyanate and dibutyltin dilaurate into isobornyl acrylate, then dropwise adding polyolefin polyol, keeping the temperature of 50-70 ℃ for reaction, monitoring the content of-NCO groups in the isobornyl acrylate to be 50-55% of the initial content before reaction, and finishing the reaction to obtain a semi-adduct 1 of the diisocyanate and the polyolefin polyol;
(2) adding dimethylolbutyric acid into the semi-adduct 1, keeping the temperature of 50-70 ℃ for reaction, and finishing the reaction when the content of-NCO groups in isobornyl acrylate reaches a theoretical value to obtain a carboxyl-containing intermediate product 2;
(3) sequentially adding hydroxyl acrylate and a polymerization inhibitor into the carboxyl-containing semi-adduct 2, heating to the temperature of 50-70 ℃ for continuous reaction, and finishing the reaction when the content of-NCO groups in isobornyl acrylate is monitored to be 0 to obtain an intermediate product 3 containing carboxyl and acryloyloxy;
(4) and (3) sequentially adding epoxy resin and a catalyst into the intermediate product 3, heating to 80-110 ℃ for reaction, and finishing the reaction when the acid value of a reaction system is monitored to be less than or equal to 1mgKOH/g to obtain the high-temperature-resistant and high-elongation polyurethane acrylate resin.
The theoretical value is calculated by the formula: the remaining NCO moles x 42(NCO molecular weight)/total mass of the system (i.e., isocyanate + polyolefin polyol + IBOA + dihydromethyl butyric acid + DBTDL).
The content of the above-mentioned-NCO group was measured by titration standard of di-n-butylamine, and the acid value was measured by using potassium hydroxide standard solution.
-NCO group content determination by titration with di-n-butylamine standard:
(1) the titration standard determination principle of di-n-butylamine is as follows: reacting the-NCO group with excessive di-n-butylamine to generate urea, titrating the excessive di-n-butylamine with hydrochloric acid by taking bromocresol green as an indicator, thereby calculating the amount of the di-n-butylamine consumed by the-NCO group, and further calculating the percentage content of the-NCO group in the tested object.
The content of-NCO groups in the system is determined by a di-n-butylamine back titration method, isocyanate and di-n-butylamine react quantitatively to generate urea: R-NCO + (C)4H9)2NH→RHCON(C4H9)2
The excess di-n-butylamine was titrated with a standard titration solution of hydrochloric acid, which reacted with excess di-n-butylamine:
(C4H9)2NH+HCl→(C4H9)2NH·HCl。
(2) the calculation mode of the titration standard determination of the di-n-butylamine is as follows:
formula for the calculation of the NCO group content: NCO% (((V))1-V2)NM)/G×100％
In the formula, V1The number of milliliters of hydrochloric acid standard solution used for the blank test; v2The number of milliliters of hydrochloric acid standard solution used for the titration test; n is the molar concentration of a standard hydrochloric acid solution, mol/L; m is grams per milliequivalent of isocyanate, 0.042; g is the sample mass, G.
The acid value is determined by a potassium hydroxide standard solution:
(1) the determination principle of the potassium hydroxide standard solution is as follows: reaction of potassium hydroxide with the remainder of-COOH, KOH + RCOOH → H2O + RCOOK. Adding about 0.5g of a sample (the material obtained by adding the epoxy resin into the intermediate product 3 and reacting) into a 100mL beaker, accurately weighing the sample to 0.0002g, adding about 20mL of acetone, and uniformly stirring the mixture by using a glass rod until NR-2 is completely dissolved, wherein the sample can be properly heated if the sample cannot be dissolved at normal temperature; after complete dissolution, 2-3 drops of 2% cresol red indicator were added, and after stirring well, the solution was titrated with approximately 0.2mol/L potassium hydroxide standard to a purple color change from yellow, and the volume consumed (mL) was recorded.
(2) And (4) calculating a result:
the acid value (mg (KOH)/g) was calculated as follows:
acid value (mg (KOH))/G ═ V.C (KOH)) x 56.1/G
In the formula: v-volume of potassium hydroxide consumed, mL;
c is the concentration of the standard solution of potassium hydroxide, mol/L;
g-sample weight, G.
Preferably, the molar ratio of the polyolefin polyol to the diisocyanate in step (1) is 0.2-0.5: 1; the mass ratio of the diisocyanate to the dibutyltin dilaurate is 100: (0.1-1); the mass ratio of the diisocyanate to the isobornyl acrylate is 1 (0.5-1).
Preferably, the diisocyanate in step (1) is selected from one or more of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate; the polyolefin polyol is selected from one of hydroxyl-terminated polybutadiene, hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated polybutadiene-acrylonitrile, hydroxyl-terminated styrene-butadiene liquid rubber, hydroxyl-terminated polyisoprene, hydroxyl-terminated hydrogenated polyisoprene and polystyrene polyol.
Preferably, the molar ratio of dimethylolbutyric acid to diisocyanate in step (2) is (0.1-0.3): 1.
Preferably, the molar ratio of the hydroxyl acrylate to the diisocyanate in the step (3) is (0.4-1.6):1, and the mass ratio of the hydroxyl acrylate to the polymerization inhibitor is 100: (0.1-1).
Preferably, the hydroxy acrylate in step (3) is selected from one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and pentaerythritol triacrylate; the polymerization inhibitor is selected from more than one of p-methoxyphenol, hydroquinone, 2, 5-dimethyl hydroquinone, 2, 6-di-tert-butyl-p-cresol and 2,2,6, 6-tetramethyl piperidine-nitroxide free radical.
Preferably, the mass ratio of the epoxy resin to the catalyst in the step (4) is 100 (0.1-1); the molar ratio of epoxy resin epoxy group to dimethylolbutyric acid is 1: 1; the epoxy resin is selected from more than one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac epoxy resin and o-cresol novolac epoxy resin; the catalyst is selected from more than one of N, N-dimethylbenzylamine, N-dimethylaniline, DMP-30, triethylamine, trimethyl benzyl ammonium chloride, triphenyl phosphine, triphenyl stibium, tetraethyl ammonium bromide and chromium acetylacetonate.
The second purpose of the invention is to protect the high-temperature-resistant and high-elongation polyurethane acrylic resin prepared by the preparation method. Polyurethane carbamate groups and light-curable acryloyl oxygen groups are introduced into side groups of epoxy resin molecular chains, and flexible polybutadiene molecular chain segments are introduced into the epoxy resin molecular chains, so that the system has excellent flexibility, adhesive force, wear resistance and heat resistance.
The third purpose of the invention is to protect the application of the high-temperature-resistant and high-elongation polyurethane acrylic resin in the preparation of ultraviolet-cured peelable glue.
The invention also discloses an ultraviolet curing peelable adhesive which comprises the following components in parts by mass: 30-50 parts of polyurethane acrylic resin, 1-5 parts of photoinitiator, 10-30 parts of reactive diluent, 2-10 parts of fumed silica and 1-3 parts of organic silicon defoamer.
The photoinitiator is selected from 2-hydroxy-2-methyl-1-phenyl acetone-1, 2-methyl-1- (4-methylmercaptophenyl) -2-morpholinoacetone-1, 2-phenyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, isopropyl thioxanthone, 2, 4-diethyl thioxanthone, 2,4, 6-trimethylbenzoyl diphenylphosphine oxide, bis (2,4, 6-trimethylbenzoyl) phenylphosphine oxide, bis (2, 6-difluoro-3- (1H-pyrrolyl-1) phenyl) titanocene, 9-anthyl N, N-diethylcarbamate, 2- (3-benzoylphenyl) guanidine propionate and 1- (anthraquinone-2-yl) ethyl carbamate More than one imidazole carboxylate.
The reactive diluent is selected from hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, diphenylethyl acrylate, ethoxylated phenoxy acrylate, o-phenylphenoxy acrylate, 2- (p-cumyl-phenoxy) -ethyl acrylate, 3, 5-trimethylcyclohexyl acrylate, ethoxyethoxyethyl acrylate, glycidyl methacrylate, isobornyl acrylate, isobornyl methacrylate, tetrahydrofurfuryl acrylate, lauric acid methacrylate, cyclotrimethylolpropane methylal acrylate isobornyl acrylate, dipropylene glycol diacrylate, tripropylene glycol acrylate, neopentyl glycol acrylate, propoxylated neopentyl glycol acrylate, di (meth) acrylic acid, acrylate, di (meth) acrylic acid, di (meth) acrylic acid, acrylate, 1.6-hexanediol diacrylate, tricyclodecane dimethanol diacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate and dipentaerythritol hexaacrylate.
The defoaming agent is polydimethylsiloxane and/or modified polydimethylsiloxane.
The ultraviolet curing peelable glue provided by the invention has excellent heat resistance and elongation, is applied to the temporary bonding protection of transparent conductive glass, ITO (indium tin oxide) coating of films, circuit boards and other device materials in touch screens, and can obtain products with better quality. The ultraviolet curing peelable glue is coated on transparent conductive glass in a screen printing mode, and is prepared by crosslinking and curing after ultraviolet irradiation.
Compared with the prior art, the invention has the beneficial effects that: the ultraviolet curing peelable glue provided by the invention contains high-temperature-resistant and high-elongation polyurethane acrylate resin, has excellent heat resistance and elongation, and is applied to temporary bonding protection of transparent conductive glass, ITO (indium tin oxide) coating of films, circuit boards and other device materials in touch screens.
Detailed Description
The following examples are further illustrative of the present invention and are not intended to be limiting thereof. The equipment and reagents used in the present invention are, unless otherwise specified, conventional commercial products in the art.
A preparation method of high-temperature-resistant and high-elongation polyurethane acrylic resin comprises the following steps:
(1) sequentially adding diisocyanate and dibutyltin dilaurate into isobornyl acrylate, dropwise adding polyolefin polyol, keeping the temperature of 50-70 ℃ for reaction, monitoring the content change of-NCO groups in the isobornyl acrylate, and finishing the reaction when the content of the-NCO groups is 50-55% of the initial content to obtain a semi-adduct 1 of the diisocyanate and the polyolefin polyol;
(2) adding chain extender dimethylolbutyric acid into the semi-adduct 1, keeping the temperature at 50-70 ℃, monitoring the change of-NCO groups, and finishing the reaction when the content of the-NCO groups reaches a theoretical value to obtain a carboxyl-containing intermediate product 2;
(3) sequentially adding hydroxyl acrylate and a polymerization inhibitor into the carboxyl-containing semi-adduct 2, heating to the temperature of 50-70 ℃ for continuous reaction, and finishing the reaction when determining that-NCO group in isobornyl acrylate is 0 to obtain an intermediate product 3 containing carboxyl and acryloyloxy;
(4) and adding epoxy resin and a catalyst into the intermediate product 3, heating to 80-110 ℃ for reaction, monitoring the change of the acid value of the system, and finishing the reaction when the acid value of the system is less than or equal to 1mgKOH/g to obtain the high-temperature-resistant and high-elongation polyurethane acrylate resin.
In the following examples, it is preferred that the molar ratio of polyolefin polyol to diisocyanate in step (1) is (0.2-0.5): 1; the mass ratio of diisocyanate to dibutyltin dilaurate is 100: (0.1-1); the mass ratio of diisocyanate to isobornyl acrylate is 1 (0.5-1). Further preferably, the molar ratio of polyolefin polyol to diisocyanate is from 0.25 to 0.4: 1; the mass ratio of diisocyanate to dibutyltin dilaurate is 100: (0.2-0.5); the mass ratio of diisocyanate to isobornyl acrylate is 1 (0.5-0.7).
The diisocyanate is selected from more than one of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate. The polyolefin polyol is selected from more than one of hydroxyl-terminated polybutadiene, hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated polybutadiene-acrylonitrile, hydroxyl-terminated styrene-butadiene liquid rubber, hydroxyl-terminated polyisoprene, hydroxyl-terminated hydrogenated polyisoprene and polystyrene polyol. The weight average molecular weight of the hydroxyl-terminated polybutadiene was 2000-3000.
In the following examples, the molar ratio of dimethylolbutyric acid to diisocyanate in step (2) is preferably (0.1-0.3): 1. Further preferably, the molar ratio of dimethylolbutyric acid to diisocyanate in step (2) is (0.1-0.25): 1.
In the following examples, it is preferable that the molar ratio of the hydroxy acrylate to the diisocyanate in the step (3) is (0.4-1.6):1 and the mass ratio of the hydroxy acrylate to the polymerization inhibitor is 100: (0.1-1). Further preferably, in the step (3), the molar ratio of the hydroxyl acrylate to the diisocyanate is 1:1, and the mass ratio of the hydroxyl acrylate to the polymerization inhibitor is 100 (0.3-0.5).
The hydroxyl acrylate is selected from one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and pentaerythritol triacrylate. The polymerization inhibitor is selected from more than one of p-methoxyphenol, hydroquinone, 2, 5-dimethyl hydroquinone, 2, 6-di-tert-butyl-p-cresol and 2,2,6, 6-tetramethyl piperidine-nitroxide free radical.
In the following examples, the mass ratio of the epoxy resin to the catalyst in the step (4) is preferably 100 (0.1-1); the molar ratio of epoxy resin epoxy group to dimethylolbutyric acid is 1: 1. Further preferably, the mass ratio of the epoxy resin to the catalyst in the step (4) is 100: 1; the molar ratio of epoxy resin epoxy group to dimethylolbutyric acid is 1: 1.
The epoxy resin is selected from more than one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac epoxy resin and o-cresol novolac epoxy resin. The catalyst is selected from more than one of N, N-dimethylbenzylamine, N-dimethylaniline, DMP-30, triethylamine, trimethyl benzyl ammonium chloride, triphenyl phosphine, triphenyl stibium, tetraethyl ammonium bromide and chromium acetylacetonate.
the-NCO group content in the following examples was measured using a di-n-butylamine titration standard, and the acid value was measured using a potassium hydroxide standard solution.
-NCO group content determination by titration with di-n-butylamine standard:
(1) the titration standard determination principle of di-n-butylamine is as follows: reacting the-NCO group with excessive di-n-butylamine to generate urea, titrating the excessive di-n-butylamine with hydrochloric acid by taking bromocresol green as an indicator, thereby calculating the amount of the di-n-butylamine consumed by the-NCO group, and further calculating the percentage content of the-NCO group in the tested object.
The content of-NCO groups in the system is determined by a di-n-butylamine back titration method, isocyanate and di-n-butylamine react quantitatively to generate urea: R-NCO + (C)4H9)2NH→RHCON(C4H9)2
The excess di-n-butylamine was titrated with a standard titration solution of hydrochloric acid, which reacted with excess di-n-butylamine:
(C4H9)2NH+HCl→(C4H9)2NH·HCl。
(2) the calculation mode of the titration standard determination of the di-n-butylamine is as follows:
formula for the calculation of the NCO group content: NCO% (((V))1-V2)NM)/G×100％
In the formula, V1The number of milliliters of hydrochloric acid standard solution used for the blank test; v2The number of milliliters of hydrochloric acid standard solution used for the titration test; n is the molar concentration of a standard hydrochloric acid solution, mol/L; m is grams per milliequivalent of isocyanate, 0.042; g is the sample mass, G.
The acid value is determined by a potassium hydroxide standard solution:
(1) the determination principle of the potassium hydroxide standard solution is as follows: reaction of potassium hydroxide with the remainder of-COOH, KOH + RCOOH → H2O + RCOOK. Adding about 0.5g of a sample (the material obtained by adding the epoxy resin into the intermediate product 3 and reacting) into a 100mL beaker, accurately weighing the sample to 0.0002g, adding about 20mL of acetone, and uniformly stirring the mixture by using a glass rod until NR-2 is completely dissolved, wherein the sample can be properly heated if the sample cannot be dissolved at normal temperature; after complete dissolution, 2-3 drops of 2% cresol red indicator were added, and after stirring well, the solution was titrated with approximately 0.2mol/L potassium hydroxide standard to a purple color change from yellow, and the volume consumed (mL) was recorded.
(2) And (4) calculating a result:
the acid value (mg (KOH)/g) was calculated as follows:
acid value (mg (KOH))/G ═ V.C (KOH)) x 56.1/G
In the formula: v-volume of potassium hydroxide consumed, mL;
c is the concentration of the standard solution of potassium hydroxide, mol/L;
g-sample weight, G;
in the following examples, the high-temperature resistant and high-elongation urethane acrylate resin prepared by the method introduces urethane groups and photo-curable acryloxy groups into side groups of molecular chains of epoxy resins and introduces flexible polybutadiene molecular chain segments into molecular chains of epoxy resins, so that the system has excellent flexibility, adhesive force, wear resistance and heat resistance.
In addition, it is necessary to provide a uv curable peelable adhesive using a high temperature resistant, high elongation urethane acrylate resin as a main resin.
An ultraviolet light curing peelable adhesive mainly comprises the following components in parts by mass: 30-70 parts of polyurethane acrylate resin, 1-5 parts of photoinitiator, 10-30 parts of reactive diluent, 2-10 parts of fumed silica and 1-3 parts of organic silicon defoamer.
In the following examples, the photoinitiator is preferably selected from the group consisting of 2-hydroxy-2-methyl-1-phenylpropanone-1, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropanone-1, 2-phenyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, isopropylthioxanthone, 2, 4-diethylthioxanthone, 2,4, 6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4, 6-trimethylbenzoyl) phenylphosphine oxide, bis (2, 6-difluoro-3- (1H-pyrrolyl-1) phenyl) titanocene, 9-anthracenemethyl N, N-diethylcarbamate, 2- (3-benzoylphenyl) guanidine propionate and 1- (anthraquinone-2-one) And (c) alkyl) ethyl imidazole carboxylate.
The reactive diluent is selected from the group consisting of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, diphenylethyl acrylate, ethoxylated phenoxy acrylate, o-phenylphenoxy acrylate, 2- (p-cumyl-phenoxy) -ethyl acrylate, 3, 5-trimethylcyclohexyl acrylate, ethoxyethoxyethyl acrylate, glycidyl methacrylate, isobornyl acrylate, isobornyl methacrylate, tetrahydrofurfuryl acrylate, lauric acid methacrylate, cyclotrimethylolpropane formal acrylate isobornyl acrylate, dipropylene glycol diacrylate, tripropylene glycol acrylate, neopentyl glycol acrylate, propoxylated neopentyl glycol acrylate, 1, 6-hexanediol diacrylate, propylene glycol diacrylate, styrene-acrylate, styrene-ethylene glycol diacrylate, styrene-acrylate, one or more of tricyclodecane dimethanol diacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate and dipentaerythritol hexaacrylate.
The defoaming agent is polydimethylsiloxane and/or modified polydimethylsiloxane.
Specifically, in the following preferred embodiments, the ultraviolet-curable peelable glue mainly comprises the following components in parts by mass: 55 parts of polyurethane acrylate resin, 5 parts of photoinitiator, 35 parts of reactive diluent, 3 parts of fumed silica and 2 parts of organic silicon defoamer.
The ultraviolet curing peelable glue can be obtained by mixing the components and grinding the mixture in grinding equipment. Preferably, the viscosity of the ultraviolet-curable peelable paste of the present embodiment is adjusted by hydroxyethyl methacrylate so as to facilitate screen printing on the surface of the substrate. Further preferably, the components are uniformly mixed, ground by a three-roller machine to the fineness of less than 12 mu m, and then regulated to 25000 +/-5000 cps by using hydroxyethyl methacrylate to obtain the ultraviolet curing peelable glue suitable for screen printing.
The ultraviolet light curing peelable glue has high temperature resistance and high elongation rate. The ultraviolet curing peelable glue has excellent heat resistance and elongation, is applied to temporary bonding protection of transparent conductive glass in a touch screen, ITO (indium tin oxide) coating of a film, a circuit board and other device materials, and can obtain a product with better quality.
In addition, it is necessary to provide a uv curable peelable adhesive with a high temperature resistant, high elongation urethane acrylate resin for temporary adhesion protection. Preferably, the ultraviolet curing peelable glue containing the high-temperature-resistant and high-elongation polyurethane acrylate resin is coated on the transparent conductive glass in a screen printing mode, and is subjected to crosslinking curing after being irradiated by ultraviolet light to obtain the ultraviolet curing peelable glue.
Example 1
174.2g of toluene diisocyanate and 0.5g of dibutyltin dilaurate were added to 100g of isobornyl acrylate, 800g of hydroxyl-terminated polybutadiene (weight-average molecular weight 2000) was added dropwise, the reaction temperature was maintained at 50 ℃ and the reaction was stopped when the content of-NCO groups in the system was monitored to be 50% of the initial content, to obtain a semi-adduct 1.
Adding 14.8g of chain extender dimethylolbutyric acid into the semi-adduct 1, keeping the reaction temperature at 50 ℃, and obtaining a semi-adduct 2 when the content of-NCO groups in the system is monitored to be a theoretical value.
116.12g of hydroxyethyl acrylate and 0.35g of hydroquinone are added into the semi-adduct 2, the reaction is continued at 70 ℃, and when the content of-NCO groups in the system is monitored to be zero, a semi-adduct 3 is obtained.
And finally, adding 18.2g of o-cresol formaldehyde epoxy and 0.18g of triphenyl phosphine into the semi-adduct 3, heating to 105 ℃, continuing to react, detecting the change of the acid value of the system, and finishing the reaction when the acid value in the system is monitored to be less than 1mgKOH/g to obtain the high-temperature-resistant and high-elongation polyurethane acrylate resin A.
Example 2
222.32g of isophorone diisocyanate and 0.5g of dibutyltin dilaurate were added to 150g of isobornyl acrylate, 600g of hydroxyl-terminated polybutadiene (weight-average molecular weight: 2000) was added dropwise, and the reaction temperature was maintained at 50 ℃ for 4 hours. The reaction was stopped when the-NCO group content of the system was monitored to be 50% of the initial content, giving the hemiadduct 1.
Adding 29.6g of chain extender dimethylolbutyric acid, keeping the reaction temperature at 50 ℃, and obtaining the semi-adduct 2 when the content of-NCO groups in the system is monitored as a theoretical value.
116.12g of hydroxyethyl acrylate and 0.35g of hydroquinone are added, the reaction is continued at 70 ℃, and when the content of-NCO groups in the system is monitored to be zero, the semi-adduct 3 is obtained.
And finally, adding 36.3g of novolac epoxy F51 and 0.36g of triphenylphosphine, heating to 105 ℃, continuing to react, detecting the change of the acid value of the system, and finishing the reaction when the acid value in the system is monitored to be less than 1mgKOH/g to obtain the high-temperature-resistant and high-elongation polyurethane acrylate resin B.
Example 3
174.2g of toluene diisocyanate and 0.5g of dibutyltin dilaurate were added to 100g of isobornyl acrylate, and 750g of hydroxyl-terminated polybutadiene (weight-average molecular weight 3000) was added dropwise thereto, and the reaction temperature was maintained at 50 ℃ for 4 hours. The reaction was stopped when the-NCO group content of the system was monitored to be 50% of the initial content, giving the hemiadduct 1.
Adding 37.04g of chain extender dimethylolbutyric acid, keeping the reaction temperature at 50 ℃, and obtaining the semi-adduct 2 when the content of-NCO groups in the system is monitored to be a theoretical value.
116.12g of hydroxyethyl acrylate and 0.35g of hydroquinone are added, the reaction is continued at 70 ℃, and when the content of-NCO groups in the system is monitored to be zero, the semi-adduct 3 is obtained. Adding 36.3g of novolac epoxy F51 and 0.36g of triphenylphosphine, heating to 105 ℃, continuing to react, detecting the change of the acid value of the system, and ending the reaction when the acid value in the system is monitored to be less than 1mgKOH/g to obtain the high-temperature-resistant and high-elongation polyurethane acrylate resin C.
Comparative example 1
174.2g of toluene diisocyanate and 0.5g of dibutyltin dilaurate were added to 50g of isobornyl acrylate, 500g of polyester diol (weight average molecular weight: 1000) was added dropwise thereto, and the reaction was carried out at 50 ℃ for 4 hours. The reaction was stopped when the-NCO group content of the system was monitored to be 50% of the initial content, giving the hemiadduct 1. And adding 116.12g of hydroxyethyl acrylate and 0.35g of hydroquinone, keeping the reaction temperature at 70 ℃ for continuous reaction, and finishing the reaction when the content of-NCO groups in the system is monitored to be zero to obtain the urethane acrylate resin.
Comparative example 2
174.2g of tolylene diisocyanate and 0.5g of dibutyltin dilaurate were added to 100g of isobornyl acrylate, 1500g of hydroxyl-terminated polybutadiene (weight-average molecular weight 3000) was added dropwise thereto, and the reaction was carried out at 50 ℃ for 4 hours. Stopping the reaction when the content of the-NCO group in the system is monitored to be 50% of the initial content, adding 116.12g of hydroxyethyl acrylate and 0.35g of hydroquinone, keeping the reaction temperature at 70 ℃ to continue the reaction, and obtaining the polyurethane acrylic resin when the content of the-NCO group in the system is monitored to be zero.
Comparative example 3
222.32g of isophorone diisocyanate and 0.5g of dibutyltin dilaurate were added to 150g of isobornyl acrylate, 600g of polyester diol (weight average molecular weight 2000) was added dropwise, and the reaction temperature was maintained at 50 ℃ for 4 hours. The reaction was stopped when the-NCO group content of the system was monitored to be 50% of the initial content, giving the hemiadduct 1.
Adding 29.6g of chain extender dimethylolbutyric acid, keeping the reaction temperature at 50 ℃, and obtaining a semi-adduct 2 when the content of-NCO groups in the system is monitored to be 4.19%.
116.12g of hydroxyethyl acrylate and 0.35g of hydroquinone are added, the reaction is continued at 70 ℃, and when the content of-NCO groups in the system is monitored to be zero, the semi-adduct 3 is obtained.
And finally, adding 36.3g of novolac epoxy F51 and 0.36g of triphenylphosphine, heating to 105 ℃, continuing to react, detecting the change of the acid value of the system, and finishing the reaction when the acid value in the system is monitored to be less than 1mgKOH/g, so that the epoxy resin modified polyurethane acrylate resin is obtained.
Example 4
The components are prepared into the ultraviolet curing peelable glue according to the mass percentage content listed in the table 1. The components listed in Table 1 are mixed uniformly, ground by a three-roll grinder until the fineness is less than 12 mu m, and then regulated to 250dPa.s by hydroxyethyl methacrylate, thus obtaining the ultraviolet curing peelable adhesive. Printing the ultraviolet curing identification ink on the surface of transparent conductive glass by 100T screen printing, passing the printed transparent conductive glass through an ultraviolet curing machine, and accumulating the light energy to 1200mJ/cm2. And (3) testing and evaluating the elongation at break, tensile strength and heat resistance of the ultraviolet curing peelable glue on the transparent conductive glass.
TABLE 1
Note 1: resin A, B, C was prepared as in examples 1, 2, and 3 and was used in compositions 1, 2, and 3, respectively, and the control resin was the urethane acrylate prepared in comparative examples 1, 2, and 3.
Note 2: JRCURE-1108 (general brand TPO), New Material Ltd for Tianjin long time.
Note 3: JRCURE-1104 (general reference 184), New Material Ltd for Tianjin.
Note 4: IBOA/isobornyl methacrylate, Mitsubishi Yang, Japan.
Note 5: (EO)3TMPTA, ethoxylated trimethylolpropane triacrylate, Changxing chemical industry.
Note 6: fumed silica R972, degussa germany.
And 7, note: KS-66, Japan Beacon.
The performance test evaluation standard of the ultraviolet curing peelable glue is as follows:
(1) elongation at break
And (3) after ultraviolet curing the ultraviolet curing peelable glue coated on the standard component, testing the elongation at break by using a universal tensile testing machine, wherein the elongation at break is qualified when the elongation at break is more than or equal to 150 percent, and is unqualified when the elongation at break is less than 150 percent.
(2) Tensile strength
And (3) after ultraviolet curing the ultraviolet curing peelable glue coated on the standard component, testing the tensile strength by a universal tensile testing machine, wherein the tensile strength is qualified when the tensile strength is more than or equal to 5MPa, and is unqualified when the tensile strength is less than 5 MPa.
High temperature resistance
And curing the transparent conductive glass coated with the ultraviolet curing peelable glue by ultraviolet light, and then baking the transparent conductive glass at 200 ℃ for 2 hours. The releasability was tested and the presence of residual glue was observed with a 100-fold magnifying glass. The product can be stripped and is qualified without residual glue residue, and one of the product and the product is unqualified if the product does not reach the standard.
TABLE 2
As can be seen from table 2, in the present example, the uv curable peelable adhesives 1, 2, and 3 prepared from the urethane acrylate resin containing high temperature resistance and high elongation are superior to the uv curable peelable adhesives (control groups 1, 2, and 3) prepared from the urethane acrylate resins prepared according to comparative examples 1, 2, and 3 in tensile strength of the control group 1; the control group 2 adopts hydroxyl-terminated polybutadiene, so that the elongation at break and the tensile strength are qualified, but no epoxy modification is carried out, and the high-temperature resistance is unqualified; the control group 3 adopts polyester polyol and epoxy for modification, so that the tensile strength is qualified, but the product is easy to break when being peeled off, and the elongation at break is unqualified. The ultraviolet curing peelable glue prepared from the high-temperature-resistant and high-elongation polyurethane acrylate resin has more excellent elongation and high-temperature resistance.
The above examples are only preferred embodiments of the present invention, and it should be noted that the above preferred embodiments should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and these modifications and adaptations should be considered within the scope of the invention.