Curable composition

Abstract

Provided is a method for making a curable composition that has low viscosity and rapid curing ability in the form of thin film, further has excellent resistance to emulsification and preservation stability, and has high hardness in the form of cured film, thereby achieving excellent alkali developability, which is preferably an active energy beam-curable composition, is provided. The made curable composition includes a mixture (A) of a compound having two or more (meth)acryloyl groups, and is obtained by conducting a transesterification reaction of diglycerin and/or glycerin and a compound having one (meth)acryloyl group under the presence of the following catalysts X and Y: catalyst X: a compound that is at least one member selected from the group consisting of cyclic tertiary amine having an azabicyclo structure or a salt or complex thereof, amidine or a salt or complex thereof, and a compound having a pyridine ring or a salt or complex thereof; and catalyst Y: a compound including zinc.

Claims

1. A method of producing a curable composition, which comprises a step of producing a mixture of a compound having two or more (meth)acryloyl groups that is obtained by conducting a transesterification reaction of diglycerin and/or glycerin and a compound having one (meth)acryloyl group under the presence of the following catalysts X and Y: catalyst X: a compound that is at least one member selected from the group consisting of cyclic tertiary amine having an azabicyclo structure or a salt or complex thereof, amidine or a salt or complex thereof, and a compound having a pyridine ring or a salt or complex thereof; and catalyst Y: a compound including zinc.

2. The method of producing the curable composition according to claim 1, wherein the compound having one (meth)acryloyl group is alkoxyalkyl(meth)acrylate.

3. The method of producing the curable composition according to claim 1, wherein the catalyst Y is organic acid zinc and/or zinc diketone enolate.

4. The method of producing the curable composition according to claim 1, which includes a step of mixing in a photopolymerization initiator (B) after production of the mixture.

5. The method of producing the curable composition according to claim 1, wherein the mixture has a hydroxyl valence of not more than 60 mg KOH/g.

Description

EXAMPLES

(1) The invention is described in more detail below with reference to the Examples and Comparative Examples.

(2) Note that the term part(s) hereinafter used refers to part(s) by weight.

1. Production Example

1) Production Example 1

Production of DGLY-TA by a Transesterification Method

(3) Into a 1-L flask equipped with a stirrer, a thermometer, a gas introducing tube, a rectifier, and a cooling tube, 77.00 parts (0.46 mol) of diglycerin, 627.21 parts (4.82 mol) of 2-methoxyethylacrylate, 2.45 parts (0.02 mol) of DABCO as the catalyst X, 4.00 parts (0.02 mol) of zinc acetate as the catalyst Y, and 1.42 parts (2000 wt ppm with respect to the total weight of the introduced starting materials) of hydroquinone monomethylether were introduced. The obtained liquid was bubbled with an oxygen-containing gas (5% by volume of oxygen, 95% by volume of nitrogen).

(4) While the liquid was stirred during heating at a reaction solution temperature of from 105 C. to 130 C., the pressure in the reaction system was adjusted to from 110 to 760 mmHg, thereby discharging a liquid mixture of 2-methoxyethanol obtained as by-products and 2-methoxyethyl acrylate with progress in transesterification reaction via the rectifier and the cooling tube from the reaction system. In addition, 2-methoxyethyl acrylate was added to the reaction system in an amount equivalent to the number of parts by weight of the discharged liquid, as needed. The pressure in the reaction system was adjusted back to ordinary pressure 27 hours after the start of heating and stirring to finish discharging the liquid mixture.

(5) The reaction solution was cooled to room temperature, 200 mL of n-hexane was added, and the precipitate was separated by filtration. Thereafter, 2.0 parts of aluminum silicate (KYOWAAD 700 (trade name) manufactured by Kyowa Chemical Industry Co., Ltd.) and 0.5 parts of activated carbon (TAIKO S (trade name) manufactured by Futamura Chemical Co., Ltd.) were added to the filtrate. Reduced-pressure distillation was performed at from 70 C. to 95 C. and from 0.001 to 100 mmHg for 8 hours while the filtrate was bubbled with dry air. The distilled liquid including unreacted 2-methoxyethylacrylate was separated. Pressurized filtration was performed by adding 2.0 parts of diatomaceous earth (RADIOLITE (trade name) manufactured by Showa Chemical Industry Co., Ltd.) to the tank liquid. The obtained filtrate was designated as a purified product.

(6) Composition analysis of the purified product was conducted using a high-performance liquid chromatograph equipped with a UV detector. As a result, the purified product was confirmed to include diglycerin tetraacrylate as a main component (hereinafter referred to as EX-DGLY-TA). The yield of the purified product was 93%. The hydroxyl valence of the obtained purified product was measured in accordance with the following method. As a result, it was 6 mg KOH/g. Table 1 shows the results.

(7) Method of Measuring the Valence of Hydroxyl Groups

(8) An acetylation reagent is added to a sample, followed by heating treatment in a warm bath. After natural cooling, acid titration is performed with a potassium hydroxide ethanol solution using a phenolphthalein solution as an indicator in order to obtain the hydroxyl valence.

2) Production Examples 2 and 3

Production of Polyfunctional Acrylate by a Transesterification Method

(9) Polyfunctional acrylate was produced in accordance with the method described in Production Example 1 except that the compounds listed in Table 1 were used as polyalcohols and the catalysts X and Y. Table 1 shows the results.

(10) TABLE-US-00001 TABLE 1 Hydroxyl Production Purification valence Example Abbreviation Polyalcohol Catalyst X Catalyst Y yield (%) (mg KOH/g) 1 EX-DGLY-TA Diglycerin DABCO Zinc acetate 93 6 2 EX-GLY-TA1 Glycerin N-methylimidazole Zinc acrylate 91 8 3 EX-GLY-TA2 Glycerin DMAP Zinc Acetylacetonate 89 13

3) Comparative Production Example 1

Production of Polyfunctional Acrylate by a Transesterification Method

(11) Polyfunctional acrylate was produced in accordance with the method described in Production Example 1 except that the compounds listed in Table 2 were used as a polyalcohol and the catalysts X and Y. Table 2 shows the results.

(12) TABLE-US-00002 TABLE 2 Comparative Hydroxyl Production Purification valence Example Abbreviation Polyalcohol Catalyst X Catalyst Y yield (%) (mg KOH/g) 1 EX-GLY-TA3 Glycerin Triphenylphosphine Zinc acetate 92 7

4) Comparative Production Example 2

Production of DGLY-TA by a Dehydration Esterification Method

(13) Into a flask equipped with a stirrer, a thermometer, a gas introducing tube, a rectifier, a cooling tube, and a water separator, 75.77 parts (0.46 mol) of diglycerin, 157.59 parts (2.19 mol) of acrylic acid, 129.50 parts of toluene, 6.40 parts of 70% by weight methanesulfonic acid, and 0.37 parts (1000 wt ppm with respect to the total weight of the introduced starting materials) of copper sulfate were introduced. The obtained liquid was bubbled with an oxygen-containing gas (5% by volume of oxygen, 95% by volume of nitrogen).

(14) While the liquid was stirred during heating reflux at 370 mmHg in the reaction system, water obtained as a by-product with progress in dehydration esterification reaction was discharged via the rectifier and the cooling tube from the reaction system, during which the reaction solution temperature shifted from 80 C. to 90 C. Heating of the reaction solution was terminated 5 hours after the start of heating and stirring, and the pressure in the reaction system was adjusted back to ordinary pressure to finish discharging the water.

(15) After the reaction solution was cooled to room temperature, 133 parts of toluene and 61 parts of water were added and stirred. Then, the reaction solution was allowed to stand still such that the lower layer (aqueous layer) was separated. Thereafter, 49 parts of a 20% sodium hydroxide aqueous solution was added to the upper layer (organic layer). The solution was stirred and then allowed to stand still such that the lower layer (aqueous layer) was separated. Subsequently, 28 parts of water was added to the upper layer (organic layer). The solution was stirred and then allowed to stand still such that the lower layer (aqueous layer) was separated. To the upper layer (organic layer), 0.018 parts of hydroquinone monomethylether was added. Reduced-pressure distillation was performed at from 60 C. to 90 C. and from 0.001 to 100 mmHg for 8 hours while the solution was bubbled with dry air. Thus, the distilled liquid including toluene was separated. Pressurized filtration was performed by adding 2.0 parts of diatomaceous earth (RADIOLITE (trade name) manufactured by Showa Chemical Industry Co., Ltd.) to the tank liquid. The obtained filtrate was designated as a purified product.

(16) Composition analysis of the purified product after reduced-pressure distillation was conducted using a high-performance liquid chromatograph equipped with a UV detector. As a result, the purified product was confirmed to include diglycerin tetraacrylate (hereinafter referred to as DH-DGLY-TA). The calculated yield of the purified product was 11%. The hydroxyl valence of the obtained purified product was measured in the manner described above. As a result, it was 48 mg KOH/g. Table 3 shows the results.

5) Comparative Production Example 3

Production of Polyfunctional Acrylate by a Dehydration Esterification Method

(17) Polyfunctional acrylate was produced in the manner described in Comparative Production Example 1 except that the following compounds listed in Table 2 were used as polyalcohols and a catalyst. Table 3 shows the results.

(18) TABLE-US-00003 TABLE 3 Comparative Purification Hydroxyl Production yield valence Example Abbreviation Polyalcohol Catalyst (%) (mg KOH/g) 2 DH-DGLY-TA Diglycerin Methanesulfonic acid 11 48 3 DH-GLY-TA Glycerin Sulfuric acid 8 52

6) Production Example 4

Production of Alkali-Soluble Resin as Component (H)

(19) Into a separable flask equipped with a stirrer, a thermometer, a reflux cooling tube, a drip funnel, and a nitrogen introducing tube, 52.9 parts of methacrylic acid methyl, 22.5 parts of benzyl methacrylate, 24.6 parts of acrylic acid, 230 parts of propylene glycol monomethylether acetate (PGM-AC manufactured by Kuraray Co., Ltd., hereinafter referred to as PGM-AC), and 11.0 parts of dimethyl 2,2-azobis(2-methylpropionate) were introduced in such proportions and uniformly dissolved. Then, the solution was stirred under a nitrogen stream at 85 C. for 4.5 hours, and the reaction was allowed to take place at 110 C. for 1 hour.

(20) (2) To the solution obtained in (1) above, 26.25 parts of glycidyl methacrylate, 22.5 parts of PGM-Ac, and 0.2 parts of hydroquinone monomethylether were introduced in such proportions and then stirred at 100 C. for 5 hours. Thus, a reaction solution B (solid content concentration of 31.5%) including an alkali-soluble resin (h1) was obtained.

(21) The weight-average molecular weight (Mw) of this alkali-soluble resin (h1) was 7,400 and the acid value thereof was 76 mg KOH/g (solid content conversion).

2. Examples and Comparative Examples

(22) 1) Method of Evaluating Purified Product

(23) The purified products obtained in the Production Examples and Comparative Production Examples described above were evaluated in terms of high-molecular-weight body GPC area percent (%), viscosity, resistance to emulsification, metal ion concentration and preservation stability in accordance with the following methods. Table 4 shows the results.

(24) (1) GPC Area Percent (%) of High-Molecular-Weight Body

(25) The area percent (%) of a high-molecular-weight body was calculated for the obtained purified products by GPC measurement under the following conditions.

(26) GPC Measurement Conditions

(27) Device: GPC manufactured by Waters; system name: 1515 2414 717P RI Detector: RI detector Column: Guard column: SHODEX KFG (8 m, 4.610 mm) manufactured by Showa Denko K.K.; two types of main columns: STYRAGEL HR 4E THF (7.8300 mm)+STYRAGEL HR 1THF (7.8300 mm) manufactured by Waters Column temperature: 40 C. Eluent composition: THF (including 0.03% of sulfur as an internal standard); flow rate: 0.75 mL/minute Method of calculating the area percent (%) of a high-molecular-weight body

(28) The area percent (%) was calculated based on the GPC measurement results according to the following equation (1).
Area percent of high-molecular-weight body (%)=[(RIL)/R]100(1)
Symbols and terms used in equation (1) are the same as defined above.

(29) (2) Viscosity

(30) Viscosity of the obtained purified product was measured by a type E viscometer (25 C. or 50 C.).

(31) (3) Resistance to Emulsification

(32) The obtained purified product in an amount of 3 g was dissolved in 6 g of xylene, 9 g of distilled layer was introduced into a glass test tube (18 m, hard glass), and the tube was capped. The tube was shaken vertically 10 times for emulsification and then allowed to stand still. The period of time required for complete separation between the aqueous layer and the organic layer was measured. The upper layer and the lower layer were evaluated in terms of transparency in accordance with the following criteria. There is a correlation between water separability and resistance to emulsification. A higher level of water separability indicates a higher level of resistance to emulsification in a case in which the purified product is used for ink.

(33) AA: Transparent

(34) A: Slightly turbid

(35) B: Turbid

(36) C: Emulsified

(37) (4) Metal Ion Concentration

(38) The metal ion concentration in a product is measured by a calibration curve method in accordance with JIS K 0121-1993 (General rules for atomic absorption spectrometry). To 1 g of a sample, 9 mL of methanol is added. Measurement is conducted by a frame method.

(39) There is a correlation between the metal ion concentration in polyfunctional acrylate and electric properties. By reducing the metal ion concentration in polyfunctional acrylate, metal ion migration can be prevented when forming a device using polyfunctional acrylate.

(40) (5) Preservation Stability Test

(41) A glass test tube (18 m, hard glass) containing 10 g of the obtained purified product was introduced into a heating block set to 120 C., followed by heating for 6 hours. Thereafter, the appearance was evaluated in accordance with the following criteria.

(42) A: No thickened or gelled matter observed.

(43) C: Thickened or gelled matter observed.

(44) TABLE-US-00004 TABLE 4 High- Resistance to emulsification molecular- Upper Lower Metal ion weight body Viscosity Separation layer layer concentration Preservation GPC area % (mPa .Math. s) time transparency transparency (wt ppm) stability Production EX-DGLY-TA 11.8 214 10 min A AA Na: 0.18 A Example 1 (25 C.) Production EX-GLY-TA1 18.1 28 5 min A AA Na: 0.20 A Example 2 (25 C.) Production EX-GLY-TA2 20.0 30 5 min A AA Na: 0.21 A Example 3 (25 C.) Comparative EX-GLY-TA3 18.7 27 5 min A AA Na: 0.21 C Production (25 C.) Example 1 Comparative DH-DGLY-TA 70.2 2,360 Not Na: 200 A Production (25 C.) separated Example 2 Comparative DH-GLY-TA 75.2 1,500 Not Na: 250 A Production (25 C.) separated Example 3

(45) As is apparent from the results of Production Examples 1 to 3, as the high-molecular-weight body area of the component (A) of the invention was less than 30%, low viscosity and excellent resistance to emulsification were confirmed. In addition, as the metal ion concentration was very low, there was no concern of ion elution from a cured film.

(46) Meanwhile, Comparative Production Example 1 is an example of polyfunctional acrylate obtained using, as the catalyst X, a phosphine-based compound via transesterification reaction. Although there were no problems of viscosity, emulsifiability, and ion elution, there was a problem of preservation stability.

(47) In addition, the compositions in Comparative Production Examples 2 and 3 included a component produced by a conventional dehydration esterification method, and the high-molecular-weight body area was 30% or more. Therefore, viscosity was high and resistance to emulsification was poor. In addition, as the metal ion concentration was high, there was concern of reduction of electric properties due to ion elution from a cured film.

(48) 2) Production of Active Energy Beam-Curable Composition

(49) The compounds listed in Tables 5 to 7 below were stirred and mixed in proportions shown in Tables 5 to 7, thereby producing active energy beam-curable compositions.

(50) Evaluation was conducted as described below using the obtained compositions. Tables 5 to 7 show the results.

(51) Figures in Tables 5 to 7 each represent the number of parts.

(52) Abbreviations used in Tables 5 to 7 have the following meanings. IRG907: 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one, IRGACURE 907 manufactured by BASF SE DAP-A: Diallyl phthalate prepolymer, DAISO DAP A manufactured by Daiso Co., Ltd. CARMINE 6B: Azo-based red colorant C.I. Pigment Red 57:1, Carmine 6B No. 6520 manufactured by Daido Chemical Corporation

(53) 3) Evaluation Method

(54) (1) Curing Ability

(55) The obtained compositions were each applied to a polyethylene terephthalate film (COSMOCHINE A4300 (thickness of 100 m) manufactured by Toyobo Co., Ltd.) by a bar coater such that the film thickness was adjusted to 5 m.

(56) The obtained test samples were each conveyed in the air atmosphere by a conveyor, which was adjusted to have irradiation energy of 100 mJ/cm.sup.2 per pass within an ultraviolet range (UV-A) with a center wavelength of 365 nm at an intensity of 800 mW/cm.sup.2, using a metal halide lamp manufactured by Eye Graphics Co., Ltd. such that the test samples were irradiated with ultraviolet ray.

(57) In Examples 7 and 8 and Comparative Examples 7 and 8, a coating film was dried by a hot plate at 100 C. for 3 minutes, thereby forming a coating film with a dried coat thickness of 5 m.

(58) In the method of evaluating curing ability, the number of passes until surface tucks disappeared was calculated.

(59) (2) Universal Hardness of Cured Film (evaluation as active energy beam-curable compositions for coating agents)

(60) The compositions listed in Table 5 below were each applied by a bar coater to a 10-cm square glass substrate such that the film thickness was adjusted to 20 The glass substrates were each conveyed in the air atmosphere by a conveyor, which was adjusted to have irradiation energy of 800 mJ/cm.sup.2 per path within an ultraviolet range (UV-A) with a center wavelength of 365 nm at intensity of 500 mW/cm.sup.2, using a high-pressure mercury lamp manufactured by Eye Graphics Co., Ltd. such that the glass substrates were irradiated with ultraviolet ray.

(61) The obtained cured films hardness was evaluated in terms of hardness using a super microhardness tester (H-100C manufactured by Fischer Instruments K.K.) based on universal hardness obtained when measuring surface hardness under conditions, in which the maximum load of a Vickers indenter is 20 mN at room temperature.

(62) (3) Resistance to Emulsification (evaluation as active energy beam-curable compositions for ink)

(63) The compositions listed in Table 6 were also evaluated by the method used for resistance to emulsification.

(64) The evaluation results were similar to the results shown in Table 4.

(65) (4) Alkali Developability (evaluation as active energy beam-curable compositions for pattern formation)

(66) The compositions listed in Table 7 were each applied to a 10-cm square chrome-masked glass substrate using a spin coater. Each obtained coating film was dried by a hot plate at 100 C. for 3 minutes such that a coating film with a dried coat thickness of 5 m was formed. The obtained coating films were each spray-developed with a 0.05% potassium hydroxide aqueous solution at a liquid temperature of 23 C., and the period of time required for complete dissolution was measured.

(67) TABLE-US-00005 TABLE 5 Evaluation results Composition (parts) Universal (A) (A) (B) Curing ability hardness of EX- EX- DH- DH- IRG (No. of cured film DGLY-TA GLY-TA1 DGLY-TA GLY-TA 907 passess) (N/mm.sup.2) Example 1 100 5 2 304 Example 2 100 5 2 321 Comparative 100 5 2 219 Example 1 Comparative 100 5 2 237 Example 2

(68) TABLE-US-00006 TABLE 6 Evaluation Composition (parts) results (A) (A) (B) (G) Curing ability EX- EX- DH-DGLY- DH- IRG (F) CARMINE (No. of DGLY-TA GLY-TA1 TA GLY-TA DAP-A 907 6B passes) Example 3 65 5 10 20 2 Example 4 65 5 10 20 2 Comparative 65 5 10 20 2 Example 3 Comparative 65 5 10 20 2 Example 4

(69) TABLE-US-00007 TABLE 7 Composition (parts) (A) (A) Evaluation results EX- DH- (B) (E) Curing ability Alkali EX- GLY- DH- GLY- IRG (H) PGM- (No. of developability DGLY-TA TA1 DGLY-TA TA 907 h1 Ac passes) (sec) Example 5 50 5 50 109 2 20 Example 6 50 5 50 109 2 15 Comparative 50 5 50 109 2 40 Example 5 Comparative 50 5 50 109 2 30 Example 6

(70) As is apparent from the results in Examples 1 and 2, the composition of the invention had curing ability at a level comparable to the levels of the compositions of Comparative Examples 1 and 2 each including a polyfunctional acrylate produced by a conventional dehydration esterification method. As the area percent (%) of the high-molecular-weight body of the component (A) was less than 30%, indicating that the cured film had excellent hardness.

(71) Meanwhile, in the compositions of Comparative Examples 1 and 2 each including a component produced by a conventional dehydration esterification method, polyfunctional acrylate was a composition including a high-molecular-weight body at an area percent (%) of 30% or more. Therefore, the compositions were inferior to the compositions of the Examples in terms of cured film hardness.

(72) As is apparent from the results in Examples 3 and 4, the composition of the invention showed curing ability comparable to that of the ink compositions of Comparative Examples 3 and 4 each including a polyfunctional acrylate produced by a conventional dehydration esterification method.

(73) In addition, as described above, since the component (A) had excellent resistance to emulsification, the ink composition including the component (A) also had excellent resistance to emulsification, indicating that the component (A) is favorable as an ink composition. Meanwhile, the material polyfunctional acrylate had poor resistance to emulsification for the ink compositions of Comparative Examples 3 and 4. Therefore, the ink compositions also had poor resistance to emulsification, meaning that the composition was not suitable for ink.

(74) As is apparent from the results in Examples 5 and 6, the composition of the invention showed curing ability comparable to that of the pattern formation compositions of Comparative Examples 5 and 6 each including a component produced by a conventional dehydration esterification method, and the composition of the invention had alkali developability more excellent than that of the compositions of Comparative Examples 5 and 6. Further, as described above, since the component (A) had a low metal ion concentration, it was favorable as a pattern formation composition free from concern of reduction in electric properties.

INDUSTRIAL APPLICABILITY

(75) The composition of the invention can be used for various purposes including coating such as hard coating, molding material used for mold transfer printing, nanoimprint, or the like, ink for offset or ink-jet printing, photosensitive lithographic printing plates, resists such as color resists, and so on.