JP2000229960A - New (meth)acrylic acid ester and resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject new mono functional compound useful as a reactive diluent for obtaining a resin composition having a good stability, excellent in close adhesive property and especially suitable for a printing ink. SOLUTION: This ester is a compound expressed by the formula [R1 is H, methyl or ethyl; R2 is H or methyl; and mean value of (n) is 1.3-3]. For example, acrylic acid ester-tetrahydrofrufuryl acrylate 2-(tetrahydro-2'-furanyl) methoxyethylacrylate. The compound of the formula is obtained e.g. by reacting 1 mole 2-hydroxymethyltetrahydrofuran with 1.3-3 mole alkylene oxide in the presence of an alkaline catalyst at 80-200 deg.C to obtain an adduct of alkyleneoxide in an average of 1.3-3 mole with 2-hydroxymethyltetrahydrofuran, then reacting the obtained compound with (meth)acylic acid in the presence of an esterification catalyst at 50-150 deg.C for 2-10 hr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a monofunctional (meth) acrylate having low odor and low volatility, and a resin composition using the same. More specifically, novel monofunctional (meth) acrylates and resins suitable as reactive diluents, especially as reactive diluents for printing inks such as screen printing inks, gravure printing inks, offset printing inks, intaglio printing inks, etc. Composition.

[0002]

2. Description of the Related Art Conventionally, the application of radiation-curable resin compositions to various paints, adhesives and printing inks has been studied.
It is used. In this radiation-curable resin composition, various acrylates such as tetrahydrofurfuryl acrylate are generally used as a reactive diluent. Tetrahydrofurfuryl acrylate is excellent in adhesiveness and is used for adhesives, printing inks, and the like, but has a problem of strong odor. JP-A-56-75482 proposes an improved product, for example, 2- (tetrahydro-2'-furanyl) methoxyethyl acrylate obtained by acrylated tetrahydrofurfuryl alcohol to which 1 mol of ethylene oxide has been added. Have been.

[0003]

Problems to be Solved by the Invention
The odor of 2- (tetrahydro-2'-furanyl) methoxyethyl acrylate described in JP-A-482 is slightly improved as compared with tetrahydrofurfuryl acrylate, but is not sufficient. Also, when used for printing ink, etc.,
Leaving the ink on the screen of the screen printing machine may increase the viscosity of the ink, or may thicken or solidify the ink on the transfer roll of the offset printing machine, resulting in a problem that the ink does not transfer.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies and as a result, as a reactive diluent, the resin composition has good stability and excellent adhesion, and especially a printing ink. It is possible to provide a resin composition suitable for
Successful development of a specific (meth) acrylic acid ester completed the present invention. That is, the present invention provides the following equation (1):

[0005]

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(Wherein R ₁ is a hydrogen atom, a methyl group or an ethyl group, R ₂ is a hydrogen atom or a methyl group, and n is an average number of 1.3 to 3). (Meth) acrylic acid ester (A), (2) Formula (1) described in (1)
(3) a resin composition comprising: a (meth) acrylate (A) represented by the formula: and a compound (B) having at least two ethylenically unsaturated groups in the molecule.
The resin composition according to (2), wherein the compound (B) is an oligomer selected from the group consisting of epoxy (meth) acrylate, urethane (meth) acrylate, and polyester (meth) acrylate, and (4) printing ink. (2) or (3), (5) any one of (2) to (4) containing a photopolymerization initiator (C)
The present invention relates to a resin composition described in the section.

The (meth) acrylate (A) of the present invention is represented by the above formula (1). This (meth) acrylic acid ester (A) has low odor and low volatility.
This compound is obtained by, for example, adding 1.3 to 3 mol of alkylene oxide to 2-hydroxymethyltetrahydrofuran on average to obtain an adduct of 1.3 to 3 mol of alkylene oxide on 2-hydroxymethyltetrahydrofuran on average,
Then, it is obtained by reacting (meth) acrylic acid. Examples of the alkylene oxide include C ₂ -C ₄ alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide.

The above-mentioned adduct of alkylene oxide with an average of 1.3 to 3 mol of 2-hydroxymethyltetrahydrofuran is obtained by adding 1.3 to 3 mol of the alkylene oxide to 1 mol of 2-hydroxymethyltetrahydrofuran with an alkali catalyst (for example, hydroxide). (Potassium, sodium hydroxide, triethylamine, etc.) at a temperature of 80 to 200 ° C, preferably 100 to 160 ° C. The amount of the alkali catalyst used is 0. 0 in the reaction mixture.
It is preferably used at 005 to 2% by weight.

This alkylene oxide has an average of 1.3 to 3
The reaction between the molar adduct and (meth) acrylic acid is carried out at 50 to 150 ° C. for 2 to 10 hours in the presence of an esterification catalyst. Examples of the esterification catalyst include strong acids such as sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid, and trifluoromethane acid. The amount used is preferably 0.1 to 10% by weight in the reaction mixture.

This reaction is preferably carried out in the presence of a thermal polymerization inhibitor, for example, a polymerization inhibitor selected from hydroquinone, hydroquinone monomethyl ether, catechol, t-butylcatechol, benzoquinone, phenothiazine and the like. The amount used is preferably 0.001 to 3% by weight in the reaction mixture. In addition, this reaction may be performed in the presence of a solvent such as benzene, toluene, n-hexane, n-heptane, and cyclohexane.

After completion of the esterification reaction, excess (meth) acrylic acid is neutralized with an aqueous alkali solution, the product is washed with water, the aqueous layer is separated, and the solvent is removed if necessary. The compound represented is obtained.

The resin composition of the present invention comprises a (meth) acrylate (A) represented by the formula (1) and a compound (B) having at least two ethylenically unsaturated groups in the molecule.
Use By using the (meth) acrylic acid ester (A) represented by the formula (1), it has low odor and low volatility,
A resin composition having excellent adhesiveness and stability can be obtained.

The compound (B) having at least two ethylenically unsaturated groups in the molecule used in the resin composition of the present invention includes, for example, polyfunctional (having at least two (meth) acrylate groups) (meth) ) Acrylates are preferable, and examples thereof include a polyfunctional (meth) acrylate monomer and a polyfunctional (meth) acrylate oligomer.

Polyfunctional (meth) which is one of the compounds (B)
Examples of the acrylate monomer include tricyclodecane di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, and 1,6-hexanediol. Di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropanepolyethoxytri (meth) acrylate, trimethylolpropanepolypropoxytri (meth) acrylate, glycerin polypropoxytri (meth) acrylate, bisphenol A polyethoxydi ( (Meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropanetetra (meth) acrylate Acrylate, dipentaerythritol penta and hexa (meth) acrylate mixture, dipentaerythritol polyethoxy hexa (meth) acrylate, dipentaerythritol poly propoxy hexa (meth) acrylate and the like.

Examples of the polyfunctional (meth) acrylate oligomer include epoxy (meth) acrylate, urethane (meth) acrylate, and polyester (meth) acrylate.

The epoxy (meth) acrylate which is one kind of the compound (B) includes, for example, a compound obtained by reacting an epoxy resin with (meth) acrylic acid. Suitable epoxy resins are bisphenol-type epoxy resins obtained by reacting bisphenol A or bisphenol F with epichlorohydrin, and include liquid resins and solid resins. Other novolak epoxy resins such as phenol novolak epoxy resin and cresol novolak epoxy resin;
Examples thereof include aliphatic epoxy resins such as hexanediol diglycidyl ether, glycerin diglycidyl ether, and trimethylolpropane triglycidyl ether.

As the urethane (meth) acrylate which is one kind of the compound (B), for example, a polyol (a) is reacted with an organic polyisocyanate (b) to obtain a urethane prepolymer, and then the hydroxyl group is added to the urethane prepolymer. Examples thereof include those obtained by reacting a containing (meth) acrylate (c) and those obtained by reacting the organic polyisocyanate (b) with a hydroxyl group-containing (meth) acrylate (c).

Examples of the polyol (a) include ethylene glycol, propylene glycol, 1,3-butylene glycol, neopentyl glycol, 1,6-hexanediol, polypropylene glycol, bisphenol A polyethylene glycol, polytetramethylene glycol, glycerin, Examples thereof include trimethylolpropane, polyester polyol, polycarbonate polyol, polycaprolactone polyol, polybutadiene polyol, polymer polyol, and polysiloxane polyol.

As the organic polyisocyanate (b),
Aromatic diisocyanates such as, for example, tolylene diisocyanate or diphenylmethane diisocyanate; araliphatic diisocyanates such as tetramethylxylylene diisocyanate; isophorone diisocyanate;
Examples thereof include aliphatic or cycloaliphatic diisocyanates such as bis (4-isocyanatocyclohexyl) methane, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate.

As the hydroxyl group-containing (meth) acrylate (c), for example, 2-hydroxyethyl (meth)
Monofunctional (meth) acrylate having one acrylic group such as acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate; trimethylolpropane di (meth) acrylate;
Examples thereof include polyfunctional (meth) acrylates having two or more acrylic groups, such as glycerin di (meth) acrylate, pentaerythritol tri (meth) acrylate, and dipentaerythritol penta (meth) acrylate.

The reaction between the polyol (a) and the organic polyisocyanate (b) is performed by reacting 1.1 to 2.5 equivalents of the isocyanate group in the organic polyisocyanate (b) with respect to 1 equivalent of the hydroxyl group in the polyol (a). Is preferably reacted, and particularly preferably 1.2 to 2.2 equivalents. The reaction time is preferably 5 to 20 hours. Reaction temperature is 80-1
00 ° C is preferred. Then, the hydroxyl group in the hydroxyl group-containing (meth) acrylate (c) was 0.95 with respect to 1 equivalent of the isocyanate group in the obtained urethane polymer.
The reaction is preferably performed in an amount of from 0.9 to 1.1 equivalents, particularly preferably from 0.99 to 1.05 equivalents. Reaction temperature is 80 ~
100 ° C. is preferred. The reaction time is preferably 5 to 20 hours, and usually a catalyst is used to promote the reaction. Examples of the catalyst include dibutyltin dilaurate.

The polyester (meth) acrylate, which is one type of the compound (B), comprises, for example, a reaction product of a polyester polyol and (meth) acrylic acid. Suitable polyester polyols include terminally hydroxylated polyester polyols obtained from a wide range of difunctional and polyfunctional carboxylic acids and a wide range of difunctional and polyfunctional alcohols. Suitable carboxylic acids include succinic anhydride, adipic acid, phthalic anhydride, tetrahydrophthalic anhydride. Suitable alcohols include ethylene glycol, propylene glycol, neopentyl glycol, 1,6-hexanediol, cyclohexane-1,4-dimethanol, trimethylolpropane and trimethylolethane.

When the resin composition of the present invention is applied to a printing ink, oligomers such as epoxy (meth) acrylate, urethane (meth) acrylate, and polyester (meth) acrylate are preferably used as the component (B). it can. In addition, when applied to a wear-resistant paint such as a hard coating agent, a polyfunctional monomer such as a polyfunctional (meth) acrylate monomer can be preferably used as the component (B).

In the resin composition of the present invention, the proportion of the components (A) and (B) is 2 to 60% by weight, when (A) + (B) is 100 parts by weight. It is preferably, particularly preferably, 5 to 40% by weight, and the component (B) is preferably 40 to 98% by weight, particularly preferably 6 to 98% by weight.
0 to 95% by weight.

The resin composition of the present invention contains various known monofunctional ethylenically unsaturated compounds (compounds having one ethylenically unsaturated group) as components other than the components (A) and (B). It is preferred to use. Examples of the monofunctional ethylenically unsaturated compound include an acrylate group having 1
Acrylates and N-vinylformamide. Examples of the acrylate having one acrylate group include carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, acryloyl morpholine, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, and tricyclo. [5,2,1,0
2,6] decanyl (meth) acrylate.

The resin composition of the present invention can be cured by a known method. In the case of curing by ultraviolet rays, it is necessary to use a photopolymerization initiator (C). When it is necessary to use the photopolymerization initiator (C), its amount is usually 0.1 to 15% by weight of the composition, preferably 3 to 10% by weight. The photopolymerization initiator may be any known photopolymerization initiator, but is required to have good storage stability after blending. Examples of such photopolymerization initiators include benzoins such as benzoin ethyl ether, benzoin butyl ether and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, N, N-
Acetophenones such as dimethylaminoacetophenone;
Thioxanthones such as 2,4-dithierthioxanthone, 2-chlorothioxanthone and 2-isopropylthioxanthone; ketals such as benzyldimethylketal and acetophenonedimethylketal; benzophenone, methylbenzophenone, 4,4′-bisdiethylaminobenzophenone, 4- Benzophenones such as benzoyl-4'-methyldiphenylsulfide; phosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; These can be used alone or in combination of two or more.

Further, a photosensitizer such as a tertiary amine may be used alone or in combination with two or more kinds together with the photopolymerization initiator (c). Examples of the tertiary amines include N, N-dimethylaminobenzoic acid ethyl ester,
N, N-dimethylaminobenzoic acid isoamyl ester,
Pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine and the like can be mentioned.

The resin composition of the present invention may further contain, if desired, other components, for example, a coloring agent such as a pigment or a dye; a non-reactive polymer resin such as a polyester elastomer, a polyurethane elastomer, or an acrylic polymer; Additives such as a foaming agent, a silane coupling agent, an antioxidant, an ultraviolet absorber, a light stabilizer, and a polymerization inhibitor; and inorganic fillers such as talc, silica oxide, and barium sulfate can be added.

The resin composition of the present invention comprises (A) and (B), if necessary, a photopolymerization initiator (C) and, if desired, a monofunctional ethylenically unsaturated compound and other components mixed, heated and dissolved. Can be prepared.

The resin composition of the present invention is suitably used for printing inks such as screen printing inks, offset printing inks, gravure printing inks, intaglio printing inks, etc. In addition, paints, adhesives, resists, lenses , And others.

When the resin composition of the present invention is used as a printing ink, an offset printing method is suitable as a printing method. The ink is transferred from a roll onto a substrate by an offset printing method so as to print to a thickness of 2 to 10 μm, and then cured by irradiating ultraviolet rays or electron beams. As the type of the base material, various kinds of paper, plastics such as polycarbonate, polyvinyl chloride, polyester, and polyacryl resin are generally used.

[0032]

The present invention will be described below in more detail with reference to examples. Parts in Examples are parts by weight. Synthesis Example 1: Synthesis of (meth) acrylic acid ester (A) represented by formula (1) 212 parts of adduct of tetrahydrofurfuryl alcohol with an average of 2.5 moles of ethylene oxide, 86 parts of acrylic acid,
105 parts of toluene, 45 parts of cyclohexane, 10 parts of p-toluenesulfonic acid and 0.5 part of hydroquinone were charged, and a dehydration reaction was carried out at 93 to 107 ° C.
The reaction was continued until the reaction became part. After completion of the reaction, 700 parts of toluene was added to the reaction mixture, neutralized with a 20% aqueous NaOH solution, allowed to stand, the aqueous layer (lower layer) was discarded, a 15% aqueous NaCl solution was charged into the toluene layer, and the mixture was stirred and stirred. The layer was washed and then allowed to stand. The aqueous layer (lower layer) was discarded, the toluene was distilled off, the residue was filtered, and acrylic acid, a liquid tetrahydrofurfuryl alcohol adduct of an average of 2.5 mol of ethylene oxide, was added. Ester (in the above formula (1), R1
And R2 were both hydrogen atoms and the average value of n was about 2.5). Product viscosity (25 ° C) 1
1 cps and a refractive index (25 ° C.) of 1.462. Table 1 shows the NMR measurement results.

Table 1 No.Hz ppm No.Hz ppm 1 12284.6 170.743 26 5198.4 68.888 2 12541.0 166.190 27 5165.7 68.455 3 12520.5 165.919 28 5158.1 68.353 4 9903.1 131.233 29 5153.9 68.298 5 9890.4 131.065 30 5137.1 68.075 6 9729.7 128.935 31 5024.6 66.585 9703.4 128.586 32 4827.0 63.966 8 9688.5 128.389 33 4824.7 63.936 9 5885.9 77.998 34 4811.9 63.765 10 5776.4 76.547 35 4808.7 63.723 11 5591.9 74.102 36 4798.5 63.590 12 5588.9 74.063 37 4788.8 63.460 13 5580.7 73.953 38 4658.5 61.733 39 4658.5 61.733 38 4658.5 61.733 39 4658.5 61.733 40 4523.9 59.949 16 5489.8 72.749 41 2642.2 35.014 17 5350.5 70.903 42 2547.0 33.753 18 5336.2 70.714 43 2138.2 28.335 19 5318.7 70.481 44 2121.9 28.119 20 5247.3 69.535 45 2116.3 28.045 21 5231.4 69.325 46 2106.5 27.915 22 5219.0 69.161 47 1939.0 26.941 48 25.647 24 5198.4 68.888 49 1917.8 25.414 25 5212.8 69.078

(Synthesis example of urethane (meth) acrylate) Synthesis example 2 Polyester diol (polyester diol having molecular weight of 480 and consisting of neopentyl glycol and adipic acid)
230 parts, 244.8 parts of polytetramethylene glycol (average molecular weight: about 2,000) and 200 parts of isophorone diisocyanate were charged and reacted at 85 ° C. for about 10 hours, and then 68.7 parts of 2-hydroxyethyl acrylate, p-
0.37 parts of methoxyphenol, di-n-dilaurate
0.14 parts of butyltin was charged and reacted at 85 ° C. for about 10 hours until the residual NCO concentration became 0.3% or less to obtain urethane acrylate. The viscosity of the product was 1510 poise (60 ° C.).

Synthesis Example 3 Polytetramethylene glycol (average molecular weight: 2000)
857.9 parts, tricyclodecane dimethylol
7 parts and 620.4 parts of isophorone diisocyanate were reacted at 85 ° C. for about 10 hours, and then 334 parts of 2-hydroxyethyl acrylate, 1.0 part of p-methoxyphenol and 0.4 parts of di-n-butyltin dilaurate were added.
Was charged at 85 ° C. for about 10 hours, and the residual NCO concentration was 0.1%.
The reaction was carried out until the content became 3% or less to obtain urethane acrylate. The viscosity of the product was 8000 poise (60 ° C.).

Examples 1 and 2 Comparative Examples 1 and 2 Each component was mixed in the composition as shown in Table 2 (the numerical values indicate parts by weight) and kneaded with a three-roll mill to obtain a resin composition (printing ink composition). Was prepared and various evaluations were made. The evaluation was performed by the following method.

Curability: 200 μm in thickness of prepared composition
Was printed (thickness: 5 μm) on a polycarbonate resin sheet by using an RI tester, and then irradiated with a high-pressure mercury lamp (lamp output: 2 KW) at a position 8 cm under a light source arranged in parallel (conveyor speed: 20 m / min) to cure. . The irradiation dose (mJ / cm ² ) until curing was determined. Adhesion: A cross-cut cellophane tape peel test was performed on the printed material cured by the above method.・ ・ ・: No peeling eyes and no missing eyes occur. Δ: Slight chipping is observed. C: peeling eyes and chipped eyes occurred. On-machine stability: The prepared composition was placed on a roll of an RI tester, left for 3 hours, and then printed on a 200 μm-thick polycarbonate resin sheet.
The condition was observed.・ ・ ・: There was no abnormality on the printing surface. C: Some or all of the printed surface is free of ink.

Table 2 Example Comparative Example 1 2 1 2 Acrylic ester obtained in Synthesis Example 1 38 42 Tetrahydrofurfuryl acrylate 38 2- (tetrahydro-2′-furanyl) methoxyethyl acrylate 38 Urethane obtained in Synthesis Example 2 Acrylate 32 32 32 Urethane acrylate 28 1-hydroxycyclophenyl ketone 33 33 obtained in Synthesis Example 3 (photopolymerization initiator) Irgacure 907 * 11 1 1 1 (photopolymerization initiator) 2-isopropylthioxanthone 0.2 0.2 0.2 0.2 (photopolymerization initiator) p-methoxyphenol (polymerization inhibitor) 0.1 0.1 0.1 0.1 titanium dioxide (white pigment) 30 30 30 30------------------------------------------------------------------- −−−−−−−−−−−−−−−−− Curability (mJ / cm ² ) 184 184 138 138 Adhesion ○ ○ ○ ○ On-machine Stability ○ ○ × ×

Note) * 1 Irgacure 907: Ciba
Specialty Chemicals Co., Ltd. 2-
Methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one.

As is clear from Table 2, the resin composition of Example 1 using the (meth) acrylic acid ester (A) of the present invention has a curing rate of 184 mJ / cm ² and good adhesion. is there. Further, even when the printing is performed after being left on the roll of the printing press for 3 hours, the printing is normally performed, and the stability on the printing press is also good. In contrast, Japanese Patent Application Laid-Open No. 56-754
No. 82, the resin composition of Comparative Example 2 using 2- (tetrahydro-2′-furanyl) methoxyethyl acrylate has a curing rate of 138 mJ / cm ^2, which is slower than the resin composition of the present invention. ing. In addition, when printing is performed after being left on a roll of a printing press for 3 hours, printing is not performed normally, and stability on the printing press is poor.

[0041]

The resin composition using the (meth) acrylate (A) of the present invention has good curability and adhesiveness and excellent stability on a printing press.

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Claims (5)

[Claims] (1) Formula (1) (Wherein, R ₁ is a hydrogen atom, a methyl group or an ethyl group, R ₂ is a hydrogen atom or a methyl group, and the average value of n is a number of 1.3 to _3. ) Acid ester (A). 2. A composition comprising a (meth) acrylate (A) represented by the formula (1) according to claim 1 and a compound (B) having at least two ethylenically unsaturated groups in a molecule. The resin composition characterized by the above-mentioned. 3. The resin composition according to claim 2, wherein the compound (B) is an oligomer selected from the group consisting of epoxy (meth) acrylate, urethane (meth) acrylate and polyester (meth) acrylate. 4. The resin composition according to claim 2, which is for a printing ink. 5. The resin composition according to claim 2, further comprising a photopolymerization initiator (C).