JPH09194761A - Nonsolvent type photosetting resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonsolvent type photosetting resin composition which form a coating layer excellent in curing properties, adhesion to the substrate, appearance, resistances to solvent and bending. SOLUTION: This resin composition is prepared by copolymerization of 20-90wt.% of a vinyl photopolymerizable monomer, 1-30wt.% of a hydroxyl group-bearing (meth)acrylate and 99-70wt.% of other vinyl monomers copolymerizable with them, compatible with the vinyl photopolymerizable monomer, and comprises 80-10 pts.wt. of an acrylic copolymer with a hydroxyl group value of 20-200mgKOH/g and a weight-average molecular weight of 1,000-10,000.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a solventless photocurable resin composition.

[0002]

2. Description of the Related Art Resin compositions used for coating materials such as paper, plastics and metals, inks, etc. are heat-curable resins prepared by using a solvent-based polymer in combination with an isocyanate.
Alternatively, there is a photo-curable type containing vinyl-based oligomers and monomers as main components. However, the thermosetting resin composition of the combined use system of the solvent-based polymer and the isocyanate requires a solvent volatilization step, a reaction step of the isocyanate, low productivity, and also from the viewpoint of the toxicity of the isocyanate. Not preferred. On the other hand, the photocurable resin composition has high productivity, but also has a high material cost because it contains a solvent, and the performance such as adhesion, appearance of the coating film, and bending resistance is not sufficient. Further, regardless of the thermosetting type or the photocuring type, the resin composition using a solvent is not preferable from the environmental aspect.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to produce a coating film having excellent curability, adhesion to a substrate, appearance, solvent resistance, and bending resistance, which is solvent-free type. It is to provide a curable resin composition.

[0004]

The present invention comprises 20 to 90 parts by weight of a vinyl-based photopolymerizable monomer, and a hydroxyl group-containing (meth).
A copolymer of 1 to 30% by weight of an acrylate and 99 to 70% by weight of another vinyl-based monomer copolymerizable therewith, having compatibility with the vinyl-based photopolymerizable monomer. Acrylic copolymer 80 having a hydroxyl value of 20 to 200 mgKOH / g and a weight average molecular weight of 1,000 to 10,000
-10 parts by weight of the solventless photocurable resin composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The resin composition of the present invention is a solventless photocurable resin composition containing a vinyl photopolymerizable monomer and an acrylic copolymer. The vinyl photopolymerizable monomer imparts photocurability to the resin composition and is used as a diluting monomer.

Specific examples of the vinyl-based photopolymerizable monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate and t-butyl (meth). ) Acrylate, 2-ethylhexyl (meth) acrylate, n-
Nonyl (meth) acrylate, cyclohexyl (meth)
Acrylate, benzyl (meth) acrylate, dicyclopentenyl (meth) acrylate, 2-dicyclopentenoxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, Methoxyethoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate , (Meth) acrylic acid, monofunctional (meth) acrylates such as acryloylmorpholine,

1,4-butanediol diacrylate,
1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, neopentyl glycol pivalate ester diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol Bifunctional acrylates such as diacrylate, propylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, ethylene oxide (EO) modified diacrylate of 1,4-cyclohexanedimethanol,

Trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, EO addition tri Methylolpropane tri (meth) acrylate, propylene oxide (PO) -added trimethylolpropane tri (meth) acrylate,
EO-added di (trimethylol) propane tetra (meth) acrylate, PO-added di (trimethylol) propane tetra (meth) acrylate, EO-added pentaerythritol tetra (meth) acrylate, PO-added pentaerythritol tetra (meth) acrylate, EO-added dipenta Erythritol penta (meth) acrylate,
PO-added dipentaerythritol penta (meth) acrylate, EO-added dipentaerythritol hexa (meth) acrylate, PO-added dipentaerythritol hexa (meth) acrylate, bisphenol A-
Diglycidyl ether di (meth) acrylate, 1,
Polyfunctional (meth) acrylates such as 3,5-triacryloylhexa-S-triazine, polypropylene glycol dimethacrylate, polyethylene glycol dimethacrylate,

N-vinyl-2-pyrrolidone, N-vinylimidazole, N-vinylcaprolactam, styrene,
Examples thereof include vinyl monomers such as α-methylstyrene and vinyltoluene, monomers such as triallyl cyanurate, triisocyanurate, and triallyl formal.
Particularly preferably used vinyl-based photopolymerizable monomers are 2-hydroxyethyl (meth) acrylate and 2-
Examples thereof include hydroxypropyl (meth) acrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, triethylene glycol diacrylate and tripropylene glycol diacrylate.

These vinyl-based photopolymerizable monomers may be used alone or in combination of two or more. The vinyl-based photopolymerizable monomer used is preferably a vinyl-based photopolymerizable monomer having a functional group of 1 or more and a molecular weight of 2,000 or less, and when the molecular weight exceeds 2,000. However, the viscosity of the resin composition increases, which is not preferable.

The mixing ratio of the vinyl-based photopolymerizable monomer in 100 parts by weight of the resin composition is 20 to 90 parts by weight, preferably 40 to 90 parts by weight. If it is less than 20 parts by weight, the curing rate will be slow. When it exceeds 90 parts by weight, the appearance of the coating film,
Adhesion and bending resistance are reduced.

The acrylic copolymer blended in the resin composition of the present invention is a copolymer of a hydroxyl group-containing (meth) acrylate and another vinyl monomer copolymerizable therewith, It is an essential component for producing a solventless photocurable resin composition that reduces the viscosity of the product and does not require a solvent.

Examples of the hydroxyl group-containing (meth) acrylate used for forming the acrylic copolymer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxyethyl (meth) acrylate, and the like. 2-hydroxyethyl (meth)
1 mol of ε-caprolactone adduct of acrylate, 2-
2-Ethyl-caprolactone adduct of hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth)
1 mol of ε-caprolactone adduct of acrylate, 2-
An example is a 2 mol addition product of ε-caprolactone of hydroxypropyl (meth) acrylate.

Other vinyl-based monomers copolymerizable with the hydroxyl group-containing (meth) acrylate used for producing the acrylic copolymer include methyl (meth) acrylate,
Ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, i-
Butyl (meth) acrylate, t-butyl (meth) acrylate, n-decyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate,
Stearyl (meth) acrylate, n-nonyl (meth)
Acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, adamantyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, 2-dicyclopenteno Xyethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate,

Styrene, vinyltoluene, α-methylstyrene, (meth) acrylonitrile, N-methoxymethylacrylamide, N-ethoxymethylacrylamide,
N-butoxymethyl acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate,
Methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, allylglycidyl ether, (meth) acrylic acid, crotonic acid, vinylbenzoic acid, fumaric acid, itaconic acid, maleic acid, citraconic acid, β- Carboxyethyl (meth) acrylate, β-carboxypropyl (meth) acrylate, β- (meth) acryloxyethyl acid succinate, β- (meth) acryloxyethyl acid malate, β- (meth) acryloxyethyl acid phthalate , Β- (meth) acryloxyethyl acid hexahydrophthalate, β- (meth) acryloxyethyl acid methyl hexahydrophthalate, γ- (meth) acryloxypropyl acid succinate, and the like. These vinyl monomers are used alone or in combination of two or more.

The acrylic copolymer is obtained by copolymerizing 1 to 30% by weight of a hydroxyl group-containing (meth) acrylate and 99 to 70% by weight of another vinyl monomer copolymerizable therewith by any known method. And a compatibility with the vinyl-based photopolymerizable monomer, and a hydroxyl value of 20 to 20.
200 mgKOH / g, weight average molecular weight of 1,000-
It is a copolymer of 10,000. Hydroxyl value is 20mgK
If it is less than OH / g, the adhesiveness to the substrate is insufficient, and 2
If it exceeds 00 mgKOH / g, the compatibility with the vinyl-based photopolymerizable monomer that also functions as a diluting monomer will be significantly reduced, and the viscosity of the resin composition will be high, resulting in poor coating operability. Further, when the weight average molecular weight of the acrylic copolymer is less than 1,000, the adhesion to the substrate and the appearance of the coating film are deteriorated, and when it exceeds 10,000, the viscosity of the resin composition is increased and the coating composition is increased. Workability is reduced.

The mixing ratio of the acrylic copolymer in 100 parts by weight of the resin composition is 80 to 10 parts by weight, preferably 60 to 10 parts by weight. If it is less than 10 parts by weight, the adhesion to the base material is lowered. However, if it exceeds 80 parts by weight, the photocurability is lowered and the viscosity of the resin composition is increased.

The resin composition of the present invention has an excellent curability by light, and as a light source used for curing, ultraviolet rays,
Examples include active energy rays such as electron rays and gamma rays. In particular, when ultraviolet rays are used as the active energy rays, it is preferable to add a photocatalyst compound such as a photopolymerization initiator, a photosensitizer or a photoaccelerator to the resin composition.

Examples of the photopolymerization initiator used include benzoin monomethyl ether, benzoin isopropyl ether, benzophenone, benzyl dimethyl ketal, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, and the like. , For example, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, and the like, as the photoaccelerator, for example, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, p-dimethylamino. Examples include 2-n-butoxyethyl benzoate and 2-dimethylaminoethyl benzoate.

If necessary, an organic solvent may be added to the resin composition of the present invention in order to adjust it to a desired viscosity. Examples of the organic solvent include ketone compounds such as acetone, methyl ethyl ketone and cyclohexanone, ester compounds such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate and methoxyethyl acetate, ether compounds such as diethyl ether, ethylene glycol dimethyl ether and dioxane. Aromatic compounds such as toluene, xylene, pentane,
Examples thereof include aliphatic compounds such as hexane, halogenated hydrocarbons such as methylene chloride and chlorobenzene chloroform.

The resin composition of the present invention includes a lubricant,
Additives such as abrasives, rust preventives and antistatic agents may be added.

[0022]

The present invention will be described below in more detail with reference to examples. In the examples, “parts” means “parts by weight”, and the coating film performance was evaluated by the following methods.

Curability: 80 W / cm high pressure mercury lamp (Mitsubishi Rayon Engineering Co., Ltd. UV-2503)
After irradiation with ultraviolet rays of 400 mJ / cm ² using two lamps, the finger coating dryness of the coating film was evaluated according to the following three grades. ○: Completely cured △: Slightly tacky ×: Not cured

Appearance: Luster and smoothness are visually judged. Adhesiveness: After sticking the adhesive tape on the coating film, peel it off at once,
Visually judge the adhered state of the coating film. Bending resistance: After the coated test paper was folded back 180 °, cracks in the coating film were visually judged. Solvent resistance: Methyl ethyl ketone was dipped in gauze, and the appearance was visually judged after 10 reciprocating rubbing tests. <Visual Judgment Criteria> ◎: Very good, no problem in practical use ○: Good, no problem in practical use △: Some problem in practical use ×: Bad, not practical

(Synthesis Example 1) In a four-necked flask equipped with a thermometer, a dropping funnel, a stirrer, a cooling tube, and a temperature control device,
As an initial charge, 300 parts of xylene and 700 parts of toluene were charged and the temperature was raised to 120 ° C., and then 500 parts of methyl methacrylate, 400 parts of n-butyl acrylate, 100 parts of 2-hydroxyethyl methacrylate and 100 parts of azobisisobutyronitrile were mixed. The solution was added dropwise over 4 hours for polymerization. Thereafter, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer a to obtain a resin composition A. Table 1 shows the hydroxyl value, molecular weight and resin composition viscosity of the acrylic copolymer a.

(Synthesis Example 2) 300 parts of xylene and 700 parts of toluene were initially charged into the same four-necked flask as in Synthesis Example 1 and heated to 120 ° C., then 400 parts of methyl methacrylate and 400 parts of n-butyl acrylate. Department,
A mixed solution of 200 parts of 2-hydroxyethyl methacrylate and 100 parts of azobisisobutyronitrile was added dropwise over 4 hours to polymerize. Then, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer b to obtain a resin composition B.
Table 1 shows the hydroxyl value, molecular weight and resin composition viscosity of the acrylic copolymer b.

(Synthesis Example 3) 300 parts of xylene and 700 parts of toluene were initially charged into a four-necked flask similar to that of Synthesis Example 1 and heated to 120 ° C., then 400 parts of methyl methacrylate and 300 parts of n-butyl acrylate. Department,
A mixed solution of 300 parts of 2-hydroxyethyl methacrylate and 100 parts of azobisisobutyronitrile was added dropwise over 4 hours for polymerization. Thereafter, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer c to obtain a resin composition C.
Table 1 shows the hydroxyl value, molecular weight and resin composition viscosity of the acrylic copolymer c.

[0028]

[Table 1]

(Synthesis Example 4) 300 parts of xylene and 700 parts of toluene were initially charged into a four-necked flask similar to that used in Synthesis Example 1, and the temperature was raised to 120 ° C.
A mixed solution of 0 parts, 400 parts of ethyl acrylate, 100 parts of 2-hydroxypropyl acrylate, and 100 parts of azobisisobutyronitrile was added dropwise over 4 hours for polymerization. Thereafter, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer d to obtain a resin composition D. Table 2 shows the hydroxyl value, molecular weight and resin composition viscosity of the acrylic copolymer d.

(Synthesis Example 5) 300 parts of xylene and 700 parts of toluene were initially charged into a four-necked flask similar to that used in Synthesis Example 1, and the temperature was raised to 120 ° C.
A mixed solution of 0 parts, 400 parts of ethyl acrylate, 200 parts of 2-hydroxypropyl acrylate, and 100 parts of azobisisobutyronitrile was added dropwise over 4 hours for polymerization. Thereafter, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer e to obtain a resin composition E. Table 2 shows the hydroxyl value, molecular weight, and resin composition viscosity of the acrylic copolymer e.

(Synthesis Example 6) 300 parts of xylene and 700 parts of toluene were initially charged into a four-necked flask similar to that used in Synthesis Example 1, and the temperature was raised to 120 ° C.
A mixed solution of 0 part, 300 parts of ethyl acrylate, 300 parts of 2-hydroxypropyl acrylate, and 100 parts of azobisisobutyronitrile was added dropwise over 4 hours for polymerization. Then, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer f to obtain a resin composition F. Table 2 shows the hydroxyl value, molecular weight and resin composition viscosity of the acrylic copolymer f.

[0032]

[Table 2]

(Synthesis Example 7 (Comparison)) 4 similar to Synthesis Example 1
300 parts of xylene as an initial charge in a two-necked flask,
After charging 700 parts of toluene and raising the temperature to 120 ° C., 500 parts of methyl methacrylate and 4 parts of n-butyl acrylate.
90 parts, 2-hydroxyethyl methacrylate 10 parts,
A mixed solution of 100 parts of azobisisobutyronitrile was added dropwise over 4 hours for polymerization. Thereafter, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer g to prepare a resin composition G.
I got Table 3 shows the hydroxyl value, molecular weight and resin composition viscosity of the acrylic copolymer g.

(Synthesis Example 8 (Comparison)) 4 as in Synthesis Example 1
300 parts of xylene as an initial charge in a two-necked flask,
After charging 700 parts of toluene and raising the temperature to 120 ° C., 300 parts of methyl methacrylate and n-butyl acrylate 2
00 parts, 2-hydroxyethyl methacrylate 500
Part, azobisisobutyronitrile 100 parts mixed solution 4
Polymerization was performed by dropping over time. After that, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer h to obtain a resin composition H. Table 3 shows the hydroxyl value, molecular weight and resin composition viscosity of the acrylic copolymer h.

(Synthesis Example 9 (Comparison)) 4 as in Synthesis Example 1
300 parts of xylene as an initial charge in a two-necked flask,
After 700 parts of toluene was charged and the temperature was raised to 120 ° C., 400 parts of methyl methacrylate, 400 parts of n-butyl acrylate and 200 parts of 2-hydroxyethyl methacrylate.
Part, azobisisobutyronitrile 100 parts mixed solution 4
Polymerization was performed by dropping over time. Thereafter, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer i to obtain a resin composition I. Table 3 shows the hydroxyl value, molecular weight, and resin composition viscosity of the acrylic copolymer i.

[0036]

[Table 3]

(Synthesis Example 10 (Comparative)) Xylene 300 was initially charged in a four-necked flask similar to Synthesis Example 1.
And 700 parts of toluene were charged and the temperature was raised to 120 ° C.,
Styrene 500 parts, ethyl acrylate 490 parts, 2-
A mixed solution of 10 parts of hydroxypropyl acrylate and 100 parts of azobisisobutyronitrile was added dropwise over 4 hours for polymerization. Thereafter, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer j to obtain a resin composition J. Table 4 shows the hydroxyl value, molecular weight, and resin composition viscosity of the acrylic copolymer j.

(Synthesis Example 11 (Comparative)) Xylene 300 was initially charged in the same 4-neck flask as in Synthesis Example 1.
And 700 parts of toluene were charged and the temperature was raised to 120 ° C.,
300 parts of styrene, 200 parts of ethyl acrylate, 2-
A mixed solution of 500 parts of hydroxypropyl acrylate and 100 parts of azobisisobutyronitrile was added dropwise over 4 hours for polymerization. Thereafter, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer k to obtain a resin composition K. Table 4 shows the hydroxyl value, molecular weight and resin composition viscosity of the acrylic copolymer k.

(Synthesis Example 12 (Comparative)) Xylene 300 was initially charged in a four-neck flask similar to that of Synthesis Example 1.
And 700 parts of toluene were charged and the temperature was raised to 120 ° C.,
Styrene 400 parts, ethyl acrylate 400 parts, 2-
A mixed solution of 200 parts of hydroxypropyl acrylate and 100 parts of azobisisobutyronitrile was added dropwise over 4 hours for polymerization. Thereafter, the solvent was removed under reduced pressure, and 500 parts of 1,6-hexanediol diacrylate was added to the synthesized acrylic copolymer l to obtain a resin composition L. Table 4
Shows the hydroxyl value, molecular weight and viscosity of the resin composition of the acrylic copolymer 1.

[0040]

[Table 4]

(Example 1) Resin composition A obtained in Synthesis Example 1
12 parts, 1 part of 2-hydroxyethyl methacrylate,
Diethylene glycol diacrylate 4 parts, trimethylolpropane triacrylate 3 parts, Irgacure 18
4 (manufactured by Nippon Ciba Geigy) 0.8 parts, Dia Aid A
Add 0.04 parts of D-9002 (manufactured by Mitsubishi Rayon Co., Ltd.),
A coating composition was prepared. After applying the obtained coating composition to various substrates shown in Table 5 using a bar coater (# 4), a high pressure mercury lamp (UV-2503, 80 W / cm manufactured by Mitsubishi Rayon Engineering Co., Ltd.) was used. , lamp height 20 cm, set the conveyor speed 4m / min ultraviolet cured 400 mJ / cm ² irradiated to it. Table 5 shows the evaluation results of coating film performance.

(Examples 2 to 6) In place of the resin composition A in Example 1, resin compositions B to F obtained in Synthesis Examples 2 to 6 were used.
The coating composition was applied to various substrates in the same manner as in Example 1 except that the above was used, and the composition was UV-cured. Table 5 shows the evaluation results of coating film performance.

[0043]

[Table 5]

(Comparative Examples 1 to 6) In place of the resin composition A in Example 1, the resin compositions G to be obtained in Synthesis Examples 7 to 12 were used.
The coating composition was applied to various substrates in the same manner as in Example 1 except that L was used, and the composition was UV-cured. Table 6 shows the evaluation results of coating film performance.

[0045]

[Table 6]

[0046]

The solventless photocurable resin composition of the present invention can form a coating film excellent in curability, adhesion to a substrate, appearance, solvent resistance and bending resistance. Further, since it is not essential to use a solvent, it is also excellent in terms of environment, and is preferably used in the field of coating materials for substrates such as paper, plastic, metal and the like, inks and the like.

Claims (2)

[Claims] 1. 20 to 90 parts by weight of a vinyl-based photopolymerizable monomer, 1 to 30% by weight of a hydroxyl group-containing (meth) acrylate and another vinyl-based monomer 99 to 70 copolymerizable therewith.
A copolymer with a weight percentage, having compatibility with the vinyl-based photopolymerizable monomer and having a hydroxyl value of 20 to 200 mgK
OH / g, weight average molecular weight of 1,000 to 10,000
A solvent-free photocurable resin composition comprising 80 to 10 parts by weight of the acrylic copolymer. 2. The solventless photocurable resin composition according to claim 1, wherein the vinyl photopolymerizable monomer is a vinyl photopolymerizable monomer having a functional group number of 1 or more and a molecular weight of 2,000 or less.