JPH0822993B2 - Curable coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Object of the Invention" (Field of Industrial Application) The present invention relates to a curable coating composition which is cured by active energy rays and / or heat, and further cured by irradiation with active energy rays. The present invention relates to a curable covering composition that can be subsequently heat-cured to obtain excellent film performance.

(Prior Art) In recent years, active energy ray curable coating compositions have been extensively researched, and among them, practical application is progressing in the fields of printing inks, clear varnishes, paints, adhesives and photoresists. ing. These are composed of radically polymerizable monomers and prepolymers having radical polymerizability, and optionally radical polymerization initiators and pigments. As prepolymers, alkyd acrylate, polyester acrylate, epoxy acrylate, urethane modified acrylate, etc. As the monomer, bisphenol A alkylene oxide adduct diacrylate, neopentyl glycol diacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, dipentaerythritol hexaacrylate, alkylphenol alkylene oxide adduct monoacrylate, etc. are used. In both cases, the curing reaction by irradiation with active energy rays is used.

However, in the use of active energy ray-curable coatings composed of these materials at present, especially in the field of metal printing, post-processing and steam sterilization such as retort and rotomac after the printing and heat treatment, the cured film The toughness of the cured film is required together with the flexibility.

Especially in the steam sterilization and heat treatment processes of retorts, rotomacs, etc., the printed surfaces of the cans stick to each other and are peeled off, and also in the cellophane tape peeling test of the printed surface after the treatment, the layers of the printed film or the printed film and the material of the can or It is often peeled off from the can coating. Due to this drawback, the range of use of the active energy ray-curable composition is narrowed in the field of metal printing, and performance improvement is desired.

[Structure of the Invention] (Means for Solving Problems) As a result of intensive research to improve these drawbacks, the present invention has led to the invention of a curable coating composition having excellent film performance.

That is, the present invention relates to (A) a bisphenol diglycidyl type epoxy compound and at least one monobasic acid selected from aliphatic carboxylic acids other than (meth) acrylic acid, aromatic carboxylic acids, and (hydrogenated) rosin. A curable coating composition comprising an epoxy ester resin having a hydroxyl group in the molecule, (B) benzoguanamine or a derivative thereof, and (C) a monomer having a radical-polymerizable double bond. is there.

Examples of the bisphenol glycidyl ether type epoxy resin of the present invention include bisphenol A diglycidyl ether, bisphenol A di-β methyl glycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether and glycidyl ether obtained by adding them to water, and the above glycidyl. Ε-caprolactone adduct of ether compound, bisphenol A,
Examples thereof include glycidyl ether of S or F alkylene oxide adduct.

The epoxy ester resin of the present invention is obtained by esterifying the epoxy group of an epoxy compound with a monobasic acid, and the reaction is, for example, in a four-necked flask equipped with a stirrer at 130 ° C to 200 ° C.
C., preferably between 140.degree. C. and 160.degree. C. for 1 hour.

After that, the temperature is raised to 200-300 ℃, preferably 230-280 ℃.
Then, continue until the oxidation drops below 10. All of these reactions are carried out under the reflux of an inert solvent and N ₂ gas blowing. An amine compound is used as the catalyst.

As monobasic acids, formic acid, acetic acid, propionic acid, butyric acid,
Valerian acid, trimethylacetic acid, caproic acid, n-heptanoic acid, caprylic acid, pelargonic acid, methoxyacetic acid, nonylic acid, coconut oil fatty acid, palmitic acid, stearic acid,
Aromatic carboxylic acids such as aliphatic carboxylic acids such as oleic acid, linoleic acid and linolenic acid, benzoic acid, alkylbenzoic acid, alkylaminobenzoic acid, phenylacetic acid, halogenated benzoic acid, anisic acid, benzoylbenzoic acid and naphthoic acid , Rosin, and water-added rosin.

The benzoguanamine of (B) is represented by the general formula (1).

A benzoguanamine derivative represented by the general formula (1) can also be used.

The compounding ratio of (A) and (B) is 1 hydroxyl group of the resin of (A)
The number of moles of (B) is 0.01 to 2 moles, preferably 0.
1 to 1 mol is desirable.

Examples of the monomer (C) having a radical-polymerizable double bond include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, allyl (meth) acrylate, butyl (meth) acrylate,
Amyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, capryl (meth) acrylate decyl (meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) ) Monofunctional monomers such as acrylate, benzyl (meth) acrylate, (meth) acrylate of alkylene oxide adduct of alkylphenol, and cyclohexyl (meth) acrylate. Furthermore, as a bifunctional or higher functional monomer, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate,
Polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate , Pentyl glycol (meta)
Acrylate, neopentyl glycol di (meth) acrylate, hydroxypiparyl hydroxypivalate di (meth) acrylate, hexanediol di (meth) acrylate, (di) glycerin poly (meth) acrylate, (di) glycerin alkylene oxide poly (meth) ) Acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane alkylene oxide tri (meth) acrylate ditrimethylolpropane tetra (meth) acrylate, ditrimethylolpropane alkylene oxide tetra (meth) acrylate, trimethylolethane tri (meth) acrylate , Ditrimethylolethane tetra (meth) acrylate, trimethylolethane alkylene oxide tri (meth) acrylate, Trimethylolethane alkylene oxide Te Toro (meth) acrylate, tetra methylol methane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, bisphenol A alkylene oxide di (meth) acrylate, bisphenol F alkylene oxide divinyl (meth)
Acrylate, dihydroxybenzene alkylene oxide di (meth) acrylate, trihydroxybenzene alkylene oxide di (meth) acrylate, water added bisphenol A di (meth) acrylate, water added bisphenol F di (meth) acrylate, water added bisphenol A alkylene oxide addition Di (meth) acrylate, water-added bisphenol F alkylene oxide adduct di (meth) acrylate, and the like. Other examples include lactone adduct monomers. That is, polyethylene glycol polylactonate di (meth) acrylate, polypropylene glycol polylactonate di (meth) actylate, alkylene glycol polylactonate di (meth) acrylate, glycerin polylactonate tri (meth) acrylate, diglycerin polylacton Nate tetra (meth) acrylate,
Trimethylolpropane polylactonate tri (meta)
Polyol lactonate polyacrylate such as acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol polylactonate tetra (meth) acrylate, dipentaerythritol polylactonate hexaacrylate. The lactone of the above monomer is a functional group of CO such as γ-butyrolactone 8-valerolactone and ε-caprolactone.
It is a compound containing -O- in the ring.

In the use of the coating composition of the present invention, when the active energy ray is ultraviolet light, it is necessary to add a photosensitizer, that is, a radical polymerization initiator (also a radical polymerization accelerator) (C), benzoin, Benzoin sensitizers such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, α-acrylbenzoin, benzophenone, p-methylbenzophenone, p-
Chlorobenzophenone, tetrachlorobenzophenone, o
-Arylketone sensitizers such as methyl benzoylbenzoate and acetophenone, 4,4-bisdiethylaminobenzophenone, isoamyl p-dimethylaminobenzoate, dialkylaminoarylketone sensitizers such as p-dimethylaminoacetophenone, thioxanthone, Examples thereof include polycyclic carbonyl-based sensitizers such as xanthone and halogen-substituted compounds thereof, and these can be used alone or in an appropriate combination. These photosensitizers can be used in the composition in an amount of 1 to 30% by weight, preferably 0 to 15% by weight.
It is desirable to be in the range of% by weight.

In order to obtain an active energy ray-curable ink composition, a pigment is usually dispersed in the above-mentioned diluted varnish, but this method is not particularly limited, and it can be carried out by a conventional dispersion method such as a three roll mill or a ball mill. it can. In addition to organic, inorganic, and extender pigments, a plasticizer, a surfactant, a thermal polymerization inhibitor, etc. can be added if necessary. Of course, it may be an ink composition containing no pigment. Further, other resins can be used in combination within the range that does not impair the effects of the present invention.

(Working) Conventionally, curing is performed by using the radical reaction of the (meth) acryloyl group by irradiation with active energy rays, but as described above, there are scratches during processing, destruction of the film due to retort or rotomat treatment, etc. However, the curing film formed only by irradiation with active energy rays does not have sufficient strength to withstand them.

In this case, the present invention makes use of the heat energy of curing by irradiation with active energy rays and the baking of the finishing varnish performed after the process, and by thermosetting the hydroxyl groups in the epoxy ester resin and bezoguanamine, a stronger film is formed. It is a curable composition that is not found in the conventional active energy ray-curable coating composition.

The present invention will be described below with reference to specific examples. In the examples, "part" means "part by weight" and "%" means "% by weight".

Production Example 1 Epicoat 1001 (epoxy resin manufactured by Shell Chemical Co., Ltd.)
900 parts, benzoic acid 363 parts, triethylenediamine 1 part, xylol 100 parts were charged into a 4-necked flask equipped with a stirrer, reacted under nitrogen gas flow at 150 ° C for 1 hour, and further 220 ° C,
After reacting for 5 hours, when the acid value reached 5.5, the solvent was removed,
Then, the mixture was cooled to 100 ° C., 1 part of hydroquinone and 500 parts of trimethylolpropane triacrylate were added under an air stream and stirred for about 30 minutes to dissolve. This is designated as Prepolymer C.

Production Example 2 Epicoat 1004 (Epoxy resin manufactured by Shell Chemical Co., Ltd.)
588 parts, oleic acid 412 parts, triethylenediamine 1 part,
50 parts of xylol was placed in a four-necked flask equipped with a stirrer and reacted under a nitrogen gas stream at 150 ° C for 1 hour.
After reacting for 4 hours, when the acid value reached 5.5, the solvent was removed,
Then, the mixture was cooled to 100 ° C., 1 part of hydroquinone and 200 parts of trimethylolpropane triacrylate were added under an air stream, and the mixture was stirred for about 30 minutes and dissolved. This is designated as prepolymer D.

Production Example 3 500 parts of trimethylolpropane triacrylate and 1 part of hydroquinone were heated to 110 ° C under an air stream,
500 parts of benzoguanamine (B) was gradually added with stirring and dissolved in 30 minutes. This is designated as Propolymer G.

Next, a curable coating was prepared using the prepolymer prepared in Production Example. The details are shown in Table 1 below.

Each ink of the comparative example and the example is manufactured by Akira Seisakusho RI
The color was spread on an acrylic white coated TFS plate with a tester in an amount of 0.5 cc of ink.

This was irradiated once with two 80 w / cm high pressure mercury lamps (UV lamps) at 32 m / min to cure.

Using a roll coater, a finishing varnish and eponester amino type were applied at a coating amount of 80 mg / dm, and baked at 170 ° C for 10 minutes in an electric oven.

125 days in the autoclave after the above-mentioned making panel
After the retort treatment at 60 ° C for 60 minutes, the panel after the treatment was subjected to a deterioration test of gloss and a peeling test with Nichiban cellophane tape.

Good results were obtained for all Example samples,
The effect of the present invention was confirmed.

Claims (1)

[Claims] 1. A bisphenol diglycidyl ether type epoxy compound (A) and at least one monobasic acid selected from aliphatic carboxylic acids other than (meth) acrylic acid, aromatic carboxylic acids, and (hydrogenated) rosin. A curable coating composition containing an epoxy ester resin having a hydroxyl group in the molecule, (B) benzoguanamine or a derivative thereof, and (C) a monomer having a radical-polymerizable double bond .