JP2000038426A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition good in stability of the composition and scarcely causing the discoloration of a cured product. SOLUTION: This resin composition contains (A) an oligomer selected from the group consisting of an epoxy (meth)acrylate, a polyurethane (meth)acrylate, a polyester (meth)acrylate and a mixture of two or more kinds thereof and (B) an alkyl α-hydroxymethylacrylate. The alkyl α-hydroxymethylacylate is present in an amount of 2-60 wt.% in the composition. Furthermore, the oligomer (A) is a bifunctional polyurethane (meth)acrylate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition suitable for use in colored or uncolored paints, printing inks, coatings, adhesives and other uses.

[0002]

2. Description of the Related Art Radiation-curable acrylic oligomers often have a high viscosity and must be mixed with a monomer in order to produce a composition having an appropriate viscosity for a specific application. Representative examples of such oligomers include epoxy (meth) acrylate, polyurethane (meth) acrylate and polyester (meth) acrylate. For example, JP-A-48-25095, JP-A-49-133491, and JP-A-57-83562, etc.
Photocurable compositions containing polyurethane (meth) acrylates have been described and are known. Further, the proportion of these used for printing inks, coating agents and the like is increasing.

[0003]

The above-mentioned monomers interpreting the oligomers include, for example, polycarbonate, poly (meth) acrylate resin, polyester resin, polyvinyl chloride, etc. due to the problem of adhesion to various substrates. N
-Vinylpyrrolidone is often used. By using this N-vinylpyrrolidone, paints, printing inks, coating agents, adhesives, and the like having excellent curability and adhesion can be produced, but the composition containing N-vinylpyrrolidone can be used over time. It thickens, gels and colors. Further, the cured product is colored, which is a problem particularly in the case of a composition containing a white pigment (such as titanium oxide).

[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, have found that the resin composition has good stability, excellent adhesion, and little coloring of the cured product. The present invention was completed by successfully providing a product and a cured product thereof. That is, the present invention relates to (1) epoxy (meth) acrylate, polyurethane (meth) acrylate, polyester (meth) acrylate,
A resin composition comprising an oligomer (A) and an alkyl α-hydroxymethyl acrylate (B) selected from the group consisting of at least one kind of a mixture, (2)
The composition according to (1), wherein the alkyl α-hydroxymethyl acrylate (B) is present in the composition at a ratio of 2 to 60% by weight, and (3) the oligomer (A) is a bifunctional polyurethane (meth) acrylate. The composition according to (1) or (2). (4) Containing photopolymerization initiator (C) (1)
(5) The composition according to (1) to (4), which is for a printing ink.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, an oligomer (A) is used. The oligomer (A) includes epoxy (meth) acrylate (A-1), polyurethane (meth) acrylate (A-2), and polyester (meth) acrylate (A).
-3) and a mixture of two or more thereof.

Epoxy (meth) acrylate (A-1)
Can be obtained, for example, by reacting an epoxy resin with (meth) acrylic acid. Preferred epoxy resins are bisphenol-type epoxy resins obtained by the reaction of bisphenol A or bisphenol F with epichlorohydrin, and include those of a certain width, including liquid and solid resins having a distribution of molecular weights. Has become. In addition, novolak type epoxy resins such as phenol novolak type epoxy resin and cresol novolak type epoxy resin; aliphatic ethoxy resins such as hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether and glycerin diglycidyl ether are also included. You.

[0007] Polyurethane (meth) acrylate (A-
2) comprises, for example, a reaction product of a hydroxyl group-containing (meth) acrylate and an isocyanate prepolymer. Examples of the hydroxy group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
Monofunctional (meth) acrylates such as hydroxybutyl (meth) acrylate, trimethylolpropane di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol tri (meth) acrylate,
And polyfunctional (meth) acrylates such as dipentaerythritol penta (meth) acrylate. Suitable hydroxy group-containing (meth) acrylates include, for example, 2-hydroxyethyl (meth) acrylate,
Monofunctional (meth) such as hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate
Acrylate.

[0008] Polyurethane (meth) acrylate (A-
The isocyanate prepolymer used to obtain 2) consists of the reaction product of a polyol with a diisocyanate or a polyisocyanate. Examples of the polyol include a polyether polyol and a polyester polyol. Suitable polyether polyols include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyalkylene bisphenol A (C ₂ ~C ₄ glycol, a mixture of polyalkylene (C ₂ ~C ₄₎ glycol, polytetramethylene glycol, Ethoxylated glycerol, propoxylated glycerol, ethoxylated trimethylolpropane, propoxylated trimethylolpropane,
Ethoxylated trimethylolethane, propoxylated trimethylolethane, all of which comprise about 5
It has a molecular weight ranging from 00 to about 6000.

Suitable polyester polyols include a wide range of difunctional carboxylic acids (having two carboxyl groups) or polyfunctional carboxylic acids (having three or more carboxyl groups) and a wide range of difunctional (hydroxyl groups). And a polyfunctional alcohol (having three or more hydroxyl groups) obtained from a polyfunctional alcohol (having two or more hydroxyl groups). Suitable acids include adipic, sebacic, azelaic, phthalic isomers, trimellitic and pyromellitic acids. Suitable alcohols include ethylene glycol, propylene glycol, their oligomers, 1,4-butanediol, cyclohexanediol, and tri- or higher functional alcohols such as glycerol, trimethylolpropane, trimethylolethane, their ethoxylates and Propoxylates are included, as well as polycaprolactone polyols.

Suitable diisocyanates or polyisocyanates include aromatic diisocyanates such as toluene diisocyanate or diphenylmethane diisocyanate; araliphatic diisocyanates such as tetramethyl xylylene diisocyanate; isophorone diisocyanate, bis-isocyanate cyclohexylmethane, hexamethylene diisocyanate, Aliphatic or cycloaliphatic diisocyanates such as trimethylhexamethylene diisocyanate are included.

Polyester (meth) acrylate (A-
3) consists of a reaction product of a polyester polyol and (meth) acrylic acid. Suitable polyester polyols include a wide range of difunctional carboxylic acids (having two carboxyl groups) or polyfunctional carboxylic acids (having three or more carboxyl groups) and a wide range of bifunctional (having two hydroxyl groups). Having) or a polyfunctional alcohol (having 3 hydroxyl groups)
And at least one of which has a hydroxyl group. Suitable 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 are included.

In the present invention, an alkyl α-hydroxymethyl acrylate (B) is used. By using the alkyl α-hydroxymethyl acrylate (B) as a diluent for the oligomer (A), the viscosity is reduced, the storage stability is excellent, the curability is good, and the cured product has good adhesion to the substrate. And excellent performance in colorability and the like. The use of an alkyl α-hydroxymethyl acrylate (B) is particularly useful for a polyurethane (meth) acrylate-containing composition having a high viscosity. Examples of the alkyl α-hydroxymethyl acrylate (B) include methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, butyl α-hydroxymethyl acrylate, and hexyl α-hydroxymethyl acrylate.

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

In the resin composition of the present invention, various known ethylenically unsaturated compounds can be used as components other than the components (A) and (B), but the components (A) and (B) Other (meth) acrylates are preferred.
The amount of the ethylenically unsaturated compound used is 0% in the resin composition.
It is preferably from 50 to 50% by weight, particularly preferably from 10 to 40% by weight. As the ethylenically unsaturated compound, one or two or more compounds can be mixed and used at an arbitrary ratio, if necessary. Ethylenically unsaturated compounds are readily available on the market.

Examples of the (meth) acrylates other than the components (A) and (B) include tetrahydrofurfuryl (meth) acrylate, carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, Acryloylmorpholine, N-vinylcaprolactone, 2-ethylhexyldiethoxy (meth) acrylate, hydrogenated dicyclopentadiene (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, tricyclodecanedi (meth) acrylate , Tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, Methylolpropane tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, trimethylolpropane polypropoxytri (meth) acrylate, glycerin polypropoxytri (meth) acrylate, bisphenol A polyethoxydiacrylate, pentaerythritol tri ( (Meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropanetetra (meth) acrylate, a mixture of dipentaerythritol penta and hexa (meth) acrylate,
Monomers such as dipentaerythritol polyethoxyhexa (meth) acrylate and dipentaerythritol polypropoxyhexa (meth) acrylate can be exemplified.

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). It is preferable to use a photopolymerization initiator (C) having good storage stability after blending. Preferred photopolymerization initiators include, for example, benzoins, acetophenones, thioxanthones, ketals, benzophenones, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and the like. These can be used alone or in combination of two or more. When it is necessary to use the photopolymerization initiator (C), its amount is usually 0.1 to 1%
It is 5% by weight, preferably 3-10% by weight. Examples of benzoins include benzoin ethyl ether, benzoin butyl ether, benzoin isopropyl ether and the like. As the acetophenones, for example, 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-dimethylaminoacetophenone and the like. Examples of thioxanthones include 2,4-diethylthioxanthone, 2
-Chlorothioxanthone, 2-isopropylthioxanthone and the like. Examples of ketals include benzyl dimethyl ketal, acetophenone dimethyl ketal, and the like. Examples of the benzophenones include benzophenone, methylbenzophenone, 4,4′-bisdiethylaminobenzophenone, 4-benzoyl-
4'-methyldiphenyl sulfide and the like.

Further, the photosensitizer can be used alone or in combination with two or more kinds. Examples of the photosensitizer include N, N-dimethylaminobenzoic acid ethyl ester,
N, N-dimethylaminobenzoic acid isoamyl ester,
Tertiary amines such as pentyl-4-dimethylaminobenzoate, triethylamine and triethanolamine.

The resin composition of the present invention may optionally contain 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; a leveling agent, an antifoaming agent, or a silane coupling agent. Additives such as antioxidants, ultraviolet absorbers, light stabilizers, and polymerization inhibitors; and inorganic fillers such as talc, silica oxide, and barium sulfate.

The composition of the present invention is prepared by mixing (A) and (B), if desired, a photopolymerization initiator (C), a coloring agent, a non-reactive polymer resin, various additives, and an inorganic filler. It can be prepared by dissolving.

The composition containing a photopolymerization initiator is applied, for example, to the surface of a substrate, and then cured by irradiating ultraviolet rays. The composition can be applied on a wide range of substrates including paper, rigid and flexible plastics, metal substrates, cement, glass, stone, ceramic, wood, and others.

The composition of the present invention can be applied to a wide range of uses such as paints, printing inks, coating agents, adhesives and others. Specific uses include, for example, screen printing inks, woodwork paints, Fresnel lenses And optical fiber coating agents.

When the resin composition of the present invention is used as a printing ink, a screen printing method is suitable as a printing method. It is printed on a substrate (for example, polycarbonate, polyvinyl chloride, etc.) to a thickness of 10 to 30 μ by a screen printing method, and then cured by ultraviolet irradiation.

[0023]

The present invention will be described below in more detail with reference to examples. Parts in Examples are parts by weight. (Synthesis example of polyurethane (meth) acrylate (A)) Synthesis example 1 Polyester diol (polyester diol having molecular weight of 480 and comprising neopentyl glycol and adipic acid)
230 parts, 244.8 parts of polytetramethylene glycol (average molecular weight: about 2000) 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
-Methoxyphenol 0.37 parts, dilauric acid di-n
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 a polyurethane acrylate (A1). The viscosity of the product was 1510 poise (60 ° C.).

Synthesis Example 2 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.
The reaction was carried out at 85 ° C. for about 10 hours until the residual NCO concentration became 0.3% or less, to obtain a polyurethane acrylate (A2). The viscosity of the product is 8000
Poise (60 ° C.).

Synthesis Example 3 384 parts of polyester diol (average molecular weight of 480 composed of neopentyl glycol and adipic acid), propylene glycol modified polytetramethylene glycol (PPTG-2000, manufactured by Hodogaya Chemical Co., Ltd., average molecular weight 2)
000) and Coronate 2094 (manufactured by Nippon Polyurethane Co., Ltd., diisocyanate compound, 1 mol of hydrogenated bisphenol A and hexamethylene diisocyanate 2)
864 parts, reacted at 85 ° C. for about 10 hours, and then charged 176.4 parts of 2-hydroxyethyl acrylate and 0.9 part of p-methoxyphenol, About 15 hours at 85 ° C, residual N
The reaction was carried out until the CO concentration became about 0.3% or less to obtain a polyurethane acrylate (A3). The viscosity of the product was 6,800 poise (60 ° C.).

Examples 1 to 3 and Comparative Examples 1 and 2 Each component was mixed according to the formulation shown in Table 1 (the numerical values indicate parts by weight) and kneaded with a three-roll mill to obtain a resin composition (printing ink composition). Was prepared. Various evaluations were performed using this resin composition. The evaluation method is as follows.

Curability: The prepared composition was printed on a 1 mm-thick polycarbonate resin by a screen printing method (thickness: 15 μm), and then a high-pressure mercury lamp (lamp output: 2)
kw) at a position of 8 cm under a light source arranged in parallel (conveyor speed 20 m / min) to cure. The irradiation dose (mJ / cm2) until curing was determined.

Colorability: 9% of the printed matter cured by the above method
After standing at 0 ° C. for 24 hours, the degree of coloring of the printed surface was observed.・ ・ ・: Almost no discoloration. Δ: Discolored slightly. ×: Discoloration is remarkable. Adhesion: The printed material cured by the above method was subjected to a cross-cut cellophane tape peeling test.・ ・ ・: No peeling eyes and no missing eyes occur. Δ: Slight chipping is observed. C: peeling eyes and chipped eyes occurred. Solution stability: 100 g of the prepared composition was placed in a brown 100 ml polybin, left at 70 ° C., and after 30 days,
The presence or absence of gelation was observed. ○ ・ ・ ・ ・ No gelation. X: Gelled.

[0029]

Table 1 Example 1 Comparative Example 1 2 3 12 1 Urethane acrylate obtained in Synthesis Example 1 (A1) 35 35 Urethane acrylate obtained in Synthesis Example 2 (A2) 35 35 Urethane acrylate obtained in Synthesis Example 3 A3) 28 methyl α-hydroxymethyl acrylate 28 ethyl α-hydroxymethyl acrylate 35 35 N-vinylpyrrolidone 28 35 2-hydroxy-3-phenyloxypropyl acrylate 77 tetrahydrofurfuryl acrylate 7 1-hydroxycyclophenyl ketone (photopolymerization Initiator) 3 3 3 3 3 Irgacure 907 * 1 (photopolymerization initiator) 1 1 1 1 1 2-isopropylthioxanthone (photopolymerization initiator) 0.2 0.2 0.2 0.2 0.2 p-methoxyphenol (polymerization inhibitor) 0.1 0.1 0.1 0.1 0.1 Titanium dioxide (white pigment) 30 30 30 30 30 Curability (mJ / cm < ² >) 172 207 172 139 104 Colorability ○ ○ ○ × × Adhesion ○ ○ ○ ○ ○ Stability of liquid ○ ○ ○ × ×

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

From the evaluation results shown in Table 1, the resin composition of the present invention is excellent in stability, and the cured product is less colored and has good adhesion.

[0032]

The resin composition of the present invention has good stability of the composition, little coloring of the cured product, and is useful for colored and uncolored paints, printing inks, coating agents, adhesives and other uses. is there.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 4J027 AB10 AB15 AB16 AB18 AB19 AB23 AB24 AB25 AC03 AC04 AC06 AE02 AE03 AE04 AG03 AG04 AG09 AG12 AG13 AG15 AG23 AG24 AG27 AJ08 BA02 BA07 BA08 BA10 BA13 BA19 BA23 BA24 BA26 BA27 CB10 CC05 CD08 CD09 4J039 AE04 AE05 AF03 BC12 BC16 BC20 BC33 BC54 BE27 CA04 EA29 EA44 GA10

Claims (5)

[Claims] An oligomer (A) selected from the group consisting of epoxy (meth) acrylate, polyurethane (meth) acrylate, polyester (meth) acrylate and a mixture of two or more thereof, and an alkyl α-hydroxymethyl acrylate (B A) a resin composition comprising: 2. The composition according to claim 1, wherein the alkyl α-hydroxymethyl acrylate (B) is present in the composition in a proportion of 2 to 60% by weight. 3. The composition according to claim 1, wherein the oligomer (A) is a bifunctional polyurethane (meth) acrylate. 4. The composition according to claim 1, further comprising a photopolymerization initiator (C). 5. The composition according to claim 1, which is for a printing ink.