JPH0711166A - Coating composition curable with active energy ray - Google Patents

Abstract

PURPOSE:To obtain the subject compsn. which cures rapidly. CONSTITUTION:This coating compsn. comprises tripentaerythritol hepata-or octa(meth)acrylate or tetrapentaerythritol nona-or deca(meth)acrylate, a non- radical-polymerizable resin having a softening point of 30 deg.C or higher, and, if necessary, a photopolymn. initiator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active energy ray-curable coating composition, and more particularly to an active energy ray-curable coating composition which is useful as a printing ink or an overcoat varnish and has an excellent rapid curing property.

[0002]

2. Description of the Related Art Printing inks and overcoat varnishes using active energy rays are composed of a composition containing a radically polymerizable resin, a diluent and a coloring agent such as a pigment in printing inks. As the radically polymerizable resin, a component obtained by adding a (meth) acrylic acid component to a resin component such as alkyd (meth) acrylate, polyester (meth) acrylate, and epoxy (meth) acrylate has been used.
The diluent used in combination with the radically polymerizable resin component is bisphenol A alkylene oxide adduct di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetraacrylate, tetra Methylolmethane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, alkylphenol alkylene oxide adduct mono (meth) acrylate, etc. are used. Among these diluents, dipentaerythritol hexa (meth) acrylate and ditrimethylolpropane tetraacrylate were known to have good curability. However,
Printing speeds in recent years have reached 80 to 150 m / min, and conventionally known diluents have been unsatisfactory to cope with such high printing speeds.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides an active energy ray-curable coating composition excellent in rapid curing property. Further, the present invention provides an active energy ray-curable coating composition which is highly useful as a printing ink or overcoat varnish.

[0004]

[Means for Solving the Problems] That is, the present invention provides a hepta- or octa- (meth) acrylate of tripentaerythritol or a nona- or deca- (meth) acrylate of tetrapentaerythritol, a non-radical-polymerizable resin having a softening point of 30 ° C. or higher. And an active energy ray-curable coating composition, which comprises a photopolymerization initiator if necessary.

The hepta- or octa- (meth) acrylate of tripentaerythritol or the nona- or deca- (meth) acrylate of tetrapentaerythritol used as a diluent in the present invention is a hydroxyl group of pentaerythritol trimer or tetramer. It can be produced by reacting acrylic acid or methacrylic acid. The reaction amount is 1 for tripentaerythritol.
The amount is (8) moles per mole, and tetrapentaerythritol is 10 moles per mole, but (meth) acrylic acid in an amount a little less than that may be used. 80 reactions
It is carried out at a temperature of 120 ° C. in air or an inert gas using a polymerization inhibitor such as hydroquinone and an acidic catalyst such as sulfuric acid or p-toluenesulfonic acid.

The non-radical-polymerizable radical-polymerizable resin having a softening point of 30 ° C. or higher used in the present invention is diallyl phthalate resin, alkyd resin, polyester resin, epoxy ester resin, urethane resin, etc. Examples thereof include modified resins modified with alcohol and the like.

The active energy ray-curable coating composition of the present invention may further contain the following reactive diluent. The reactive diluent referred to in the present invention is a liquid substance having a viscosity of 200 poise or less (25 ° C.), preferably 150 poise or less. Alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth) acrylates of alkylene oxide adducts of alkylphenols,
Monofunctional diluents such as cyclohexyl (meth) acrylate and benzyl (meth) acrylate.

Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, etc. di, tri, tetra or poly. Alkylene glycol di (meth) acrylate,
Tetramethylolmethane tetra (meth) acrylate,
Trimethylolethane tri (meth) acrylate, ditrimethylolethane tritetra (meth) acrylate,
Trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetraacrylate, glycerin tri (meth) acrylate, diglycerin tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the alkylene oxide (meth) of the polyols constituting them. Acrylate etc.

Bisphenol A alkylene oxide di (meth) acrylate, bisphenol F alkylene oxide di (meth) acrylate, hydrogenated bisphenol A di (meth) acrylate, hydrogenated bisphenol F di (meth) acrylate, hydrogenated bisphenol A alkylene oxide addition Di (meth) acrylate, hydrogenated bisphenol F alkylene oxide adduct di (meth) acrylate. Polylactonate di (meth) acrylate of alkylene glycol such as polyethylene glycol and polypropylene glycol, glycerin, diglycene,
Trimethylolpropane, ditrimethylolpropane,
Multifunctional diluents such as polylactonate (meth) acrylates such as pentaerythritol and dipentaerythritol.

The active energy ray-curable composition of the present invention contains 50 to 300 parts by weight of a reactive diluent to 100 parts by weight of a non-radical-polymerizable resin, and 30 to 100% by weight of the reactive diluent. Is tripentaerythritol hepta or octa (meth) acrylate or tetrapentaerythritol nona or deca (meth) acrylate.

The active energy ray-curable composition of the present invention, when ultraviolet rays are used as active energy,
Add a photopolymerization initiator. As the photopolymerization initiator, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin sensitizers such as α-acrylbenzoin, benzophenone, p-methylbenzophenone, p-chlorobenzophenone, tetrachlorobenzophenone, o -Aryl ketone sensitizers such as methyl benzoylbenzoate and acetophenone, 4,4-bisdiethylaminobenzophenone, p
-Diamylaminoarylketone-type sensitizers such as isoamyl dimethylaminobenzoate and p-dimethylaminoacetophenone, polycyclic carbonyl-type sensitizers such as thioxanthone, xanthone and halogen-substituted compounds thereof, Irgacure 907, Irgacure 369, ZLI331 (Ciba Geigy) Company trade names) and the like can be used alone or in combination. The addition amount of the photopolymerization initiator is preferably 3 to 15% by weight based on the total amount of the radically polymerizable resin and the reactive diluent.

When the active energy ray-curable composition of the present invention is used as a printing ink composition, a pigment is added to a composition comprising a radically polymerizable resin, a reactive diluent and, if necessary, a photopolymerization initiator. Is added. As a method for dispersing the pigment, a triple roll, a ball mill or the like can be used. A plasticizer, a surfactant and a thermal polymerization inhibitor may be added depending on the use. Moreover, you may mix | blend the resin which does not have radical polymerizability of this invention. When the obtained composition does not contain a printing ink or a pigment, it can be mainly applied as an overcoat varnish on a paper or a metal substrate by a roll coater.

[0013]

[Examples] Examples will be described below. The middle part is part by weight. Synthesis Example 1 100 parts of benzene, 390 parts of tripentaerythritol, 1 part of hydroquinone, 10 parts of p-toluenesulfonic acid, and 576 parts of acrylic acid were charged into a reaction vessel, and reacted at 80 ° C. in an air flow of an equal amount of nitrogen and air, The temperature gradually rises to 90
It was kept constant in the range of ~ 115 ° C. After confirming that the oxidation was 10 or less, the solvent was removed to obtain tripentaerythritol octaacrylate (diluent a).

Synthesis Example 2 100 parts of benzene, 508 parts of tetrapentaerythritol, 1 part of hydroquinone, 10 parts of p-toluenesulfonic acid and 720 parts of acrylic acid were charged into a reaction vessel at 80 ° C. in a stream of a mixture of nitrogen and air. React and gradually raise temperature 9
It was kept constant in the range 0-115 ° C. After confirming that the oxidation was 10 or less, the solvent was removed to obtain tetrapentaerythritol decaacrylate (diluent b).

Synthesis Example 3 To 30 parts of DT170 (diallyl phthalate resin manufactured by Tohto Kasei Co., Ltd.), 0.1 part of hydroquinone was added and dissolved with 69.9 parts of tripentaerythritol octaacrylate to give a varnish. An ultraviolet curable printing ink was obtained according to the formulation described below. In the table, Examples 1 to 3 are Examples and Examples 4 to 6 are Comparative Examples.

The terms used in the table are as follows. Pigment: Rionol Red F2B (red pigment manufactured by Toyo Ink Mfg. Co., Ltd.) Initiator: Irgacure 907 / Irgacure 184 (Ciba Geigy) was added at a ratio of 2/5 (weight ratio). Diluent c: Pentaerythritol tetraacrylate Diluent d: Dipentaerythritol hexaacrylate Diluent e: Trimethylolpropane triacrylate

The UV-curable printing inks obtained in each example except Examples 3 and 6 were printed on Mitsubishi coated paper with an RI tester. Each printed sample was placed on a conveyor at a position of 10 cm under a high-pressure mercury lamp having an intensity of 120 W / cm and passed through to see if the ink was cured. The following table shows the maximum line speed at which the ink is cured when the line speed is increased from 30 m / min to 10 m / min. Also, Example 3
For the overcoat varnish of Example 6 and Example 6, the curing amount of the overcoat varnish was observed by changing the irradiation amount using a curtain beam type electron beam irradiation apparatus, and the minimum irradiation amount when the overcoat varnish was cured is shown in the following table. It was

The active energy ray-curable composition of the present invention has a maximum functionality of 8 to 10 and contains a reactive diluent having a low viscosity. It is useful as an energy ray curable printing ink or overcoat varnish composition.

Claims (1)

[Claims] 1. Hepta or octa (meth) acrylate of tripentaerythritol or nona or deca (meth) acrylate of tetrapentaerythritol,
An active energy ray-curable coating composition comprising a non-radical-polymerizable resin having a softening point of 30 ° C. or higher and, if necessary, a photopolymerization initiator.