JPH0431467A - Active energy ray curable overcoat varnish - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention 3 (Industrial Application Field) The present invention relates to an active energy ray-curable overcoat varnish. This invention relates to an active energy ray-curable overcoat varnish that is excellent in preventing problems caused by line cracking and curling of thin paper.

(Prior Art) In recent years, as printed materials have become higher quality and more sophisticated, research has been actively conducted on printing various paper cartons and labels with active energy ray overcoat varnish after printing with color ink. In order to ensure sufficient coating suitability, these active energy ray overcoat varnishes are often used with a void size of several tens of voids or less, preferably a few voids or less, at room temperature. Therefore, active energy ray curable overcoat varnishes with low Mainly viscosity radically polymerizable monomers, polymerizable prepolymer resins and various additives (slip agents,
A radical polymerization initiator is used when the active energy ray is ultraviolet rays.

Conventionally, commercially available 100% esters are (meth)acrylic esters with alcohols as radically polymerizable monomers, such as methyl (meth)acrylate.

Monofunctional acrylates such as alkyl alcohol (meth)acrylate, difunctional acrylates such as neopentyl glycol X di(meth)acrylate, di(meth)acrylate of bisphenol A x ethylene oxide adduct,
Trifunctional acrylates such as trimethylolpropane tri(meth)acrylate, tetrafunctional acrylates such as pentaerythritol tetra(meth)acrylate, and hexafunctional acrylates such as dipentaerythritol hexa(meth)acrylate have been used. However, when these radically polymerizable monomers are used in active energy ray-curable overcoat varnishes, the coating film has poor flexibility and creases in ruled lines occur after post-processing to produce paper containers. In addition, when used on thin paper such as bottle labels, the coating film shrinks and the paper curls in the direction of the printing surface, making it impossible to stack the paper after printing or automatically attaching the label to the bottle. The actual situation is that these troubles have narrowed the scope of application of these active energy ray-curable overprint varnishes.

[Structure of the invention]

(Means for Solving the Problems) As a result of intensive research aimed at correcting these drawbacks, the present invention has led to the invention of an active energy ray-curable overcoat varnish that is excellent in line cracking and low curling properties.

That is, the present invention provides an active energy ray-curable overcoat which is mainly composed of a monomer that essentially contains a radically polymerizable monomer obtained by subjecting a lactone adduct of an organic compound having an alcoholic hydroxyl group to an esterification reaction with acrylic acid or methacrylic acid. It is a coat varnish.

Examples of organic compounds having an alcoholic hydroxyl group used in the production of the radically polymerizable monomer according to the present invention include monovalent aliphatic alcohols, aromatic alcohols such as benzyl alcohol, tetrahydrofurfuryl alcohol, alicyclic alcohols, Ethylene glycol, diethylene glycol, triacetylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, butylene glycol, pentyl glycol,
Neopentyl glycol, hexanediol, glycerin, trimethylolpropane trimethylolethane, tetramethylolmethane, dipentaerythritol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, bisphenol F ethylene oxide adduct, bisphenol F propylene oxide adduct body (the number of moles of alkylene oxide added is 1i1 of bisphenol hydroxyl kJ = 1, usually 1 to 1)
It is 2 moles. ), water-added bisphenol A, water-added bisphenol F, etc. Addition of alkylene oxide to bisphenols, which are difficult to react with lactones using phenolic hydroxyl groups, involves adding bisphenols and approximately 0.5 ml of sodium hydroxide as a catalyst in an autoclave.
% by weight (based on the total amount charged including alkylene oxide), gradually add alkylene oxide, react at 160°C and below 5 Kg/cm", and reach the end point at gauge pressure below 0.1 Kg/cm". shall be.

The lactones used in the present invention include γ-butyrolactone, δ
It is a compound containing a functional group -co-o- of an ester such as -valerolactone and ε-caprolactone in the ring. Catalysts for the reaction between an organic compound having two or more alcoholic hydroxyl groups and a lactone include titanium compounds such as tetrabutyl titanate, tetrapropyl titanate, and tetraethyl titanate, and residual tin compounds such as tin octylate, dibutyltin oxide, and dibutyltin laurate. , stannous chloride, stannous bromide, stannous iodide, and other tin halides are used, and the amount used is 1 to 100% of the total amount of preparation.
oppm is preferred.

The reaction temperature is 100-300°C.

The number of moles of lactone added is 1 to 5 moles per hydroxyl group of the organic compound.

Addition of 6 moles or more is not preferred because the resulting monomer has poor curability.

The reaction product with oyoviractone, a compound having an alcoholic hydroxyl group, is subjected to an esterification reaction with acrylic acid or methacrylic acid.

This esterification reaction is carried out at a reaction temperature of 80 to 100° C. in a four-eye flask equipped with a stirrer or the like while blowing air. As a reaction catalyst, hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, etc. are used, and as a polymerization inhibitor, hydroquinone, etc. are used.

The reaction amount of (meth)acrylic acid is carboxyl group of (meth)acrylic acid/hydroxyl group of the above product=1°1 to about 0.9.

Furthermore, it is possible to mix and use the monomer used in the present invention with other commercially available monomers, and the ratio is 10010 to 10/
A range of 90 is possible. Preferably 100/0-2
The ratio is 5/75, and if the amount of monomers related to the present invention is less than this ratio, the effects of the present invention will be reduced.

Additives may be added to the overcoat varnish of the present invention, if necessary. Among the additives, polyethylene wax, fatty oil, and silicone-based ones are used as fishing slip agents. Additionally, commercial antifoaming agents are used.

In the present invention, when the active energy ray is ultraviolet rays, it is necessary to add a photosensitizer (radical polymerization initiator), such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, α-chlorobenzoin , α-acrylic benzoin, benzoin sensitizers such as Irgacure 184 (manufactured by Ciba Geigi), aryl ketone sensitizers such as benzophenone, p-methylbenzophenone, p-chlorobenzophenone, methyl 0-benzoylbenzoate, acetophenone, p Examples include dialkylaminoarylketone sensitizers such as isoamyl dimethylaminobenzoate and p-dimethylaminoacetophenone, and polycyclic carbonyl sensitizers Irgacure 907 (manufactured by Ciba Geigi) such as thioxanthone, xanthone and their halogen-substituted products. , these can be used alone or in an appropriate combination.

These photosensitizers can be used in the composition in an amount of 0 to 30% by weight, preferably in a range of 0 to 15% by weight.

A curable overcoat varnish made from active energy can be obtained by stirring and dissolving it with the above-mentioned materials at a temperature between room temperature and 100°C.

The present invention will be explained below using specific examples. All parts in the examples indicate parts by weight.

Production Example 1 Hydroxybivalyl hydroxypiparate CH,C)!
.

C1l, 218 parts of CH3, 230 parts of ε-caprolactone, and 1 part of tetraisopropyl titanate were reacted at 180 DEG C. for 10 hours after nitrogen gas was blown into the flask.

77.5 parts of the obtained hydroxypivalyl hydroxybipazito dicabrolacnate adduct, 122.5 parts of acrylic
1 part, 0.1 part of hydroquinone, 1 part of p-)luenesulfonic acid, and 10 parts of cyclohexane were reacted at 100°C for 16 hours in a flask with a stirrer and blowing air, resulting in an acid value of 5.5. At that point, it was desolvated and pumped out. This is called monomer A.

Production example 2 236 parts of pentaerythritol, 3 parts of ε-caprolactone
45 parts of tetraoctyltin and 1 part of tetraoctyltin were reacted at 200°C for 10 hours while blowing nitrogen gas in a flask with several stirrs.

81.5 parts of the obtained bisphenol F ethylene oxide tricaprolactonate adduct, 18.5 parts of acrylic acid
part, hydroquinone 0.1 part, P-)runsulfonic acid 1 part
and 10 parts of cyclohexane were reacted at 100°C for 15 hours while blowing air in a stirrer flask, and when the acid value reached 5.1, the solvent was removed and pumped out. This is called monomer B.

Production Example 3 228 parts of bisphenol A, 2 parts of sodium hydroxide, and 232 parts of propylene oxide were subjected to an addition reaction in a small autoclave. 460 parts of the obtained adduct, 7696 parts of T-butyrolact, and 1 part of dibutyl tin chloride are reacted in the same manner as in Production Example 2.

Obtained bisphenol A brobylene oxide octaptyrolactonate addition amount: 88.2 parts, methacrylic acid: 1
1.8 parts of hydroquinone, 0.1 part of p-)runsulfonic acid, and 10 parts of cyclohexane were reacted at 100°C for 16 hours while blowing air in a neck flask equipped with a stirrer, and the acid value was 5. Since it became .0, the solvent was removed and pumped out. This is called monomer C.

Production Example 4 134 parts of trimethylolpropane, 343 parts of ε-caprolactone, and 1 part of stannous chloride are reacted in the same manner as in Example 1.

476 parts of the obtained trimethylolpropane caprolactonate adduct, 194 parts of acrylic acid, hydroquinone o
, is, p-tolunesulfonic acid (6 parts) and cyclohexane (60 parts) were reacted at 100°C for 16 hours while blowing air into a necked flask equipped with a stirrer. When the acid value reached 5.0, decomposition was performed. Solvent and pump out. This is monomer D
shall be.

Production Example 5 Epicoat 828 (epoxy resin manufactured by Shell Chemical Co., Ltd.) 71.
7 parts, acrylic acid 28.3 parts, triethylenediamine 0
．． 1 part of hydroquinone and 0.1 part of hydroquinone were placed in a neck flask equipped with a stirrer and allowed to react at 100°C without blowing air. After about 15 hours, when the acid value reached 1, it was pumped out. The obtained product is designated as resin E.

Examples We would like to produce an active energy ray overcoat varnish using the radically polymerizable polymers and resins prepared in Production Examples 1 to 5. Comparative examples are also shown in Table 1 Note) Monomer W: Hydroxybivalyl hydroxybipasite Diacrylate 7mer-X: Pentaerythritol tetraacrylate #
Y: and Suphenol A 4 mole ethylene oxide adduct diacrylate #z nitrimethylolpropane triacrylate slip 荊: DK Q8701 (
Dara Corning) antifoaming agent iFs Antifoam 8
0 (#) The active energy ray-curable overcoat varnish shown in Table 1 was applied to Hokuetsu Alli Coat (coated ball made by Hokuetsu Paper Co., Ltd.) and NK Kata Art (coated paper made by Nippon Kako Paper Co., Ltd.) using a bar coater. For Example Samples 1 and 2 and Comparative Example Samples 1 and 2, place 101 under one high-pressure mercury lamp (ozone type) with an intensity of 120W/1.
It was placed on a conveyor at 0 m/min and irradiated to cure.

In addition, for Example Sample 3 and Comparative Example 9 Sample 3, a curtain beam type electron beam irradiation device was used, and 10 Mrad
It was irradiated and cured.

Below, the results regarding ruled line cracking and low curl suitability of each of the obtained coating films will be shown.

Table 2 Ruled line cracking: The coated and cured Hokuetsu alicoat paper was bent 180° with the coated side facing up and the degree of cranking of the coated layer was observed using a 50x magnifying glass.

It also has low curling properties, and can widen the range of applications of active energy ray-curable overcoat varnishes.

No cracks There is a little crank With cracks A little more crank Too many cranks Coated and hardened NK piece art paper The condition of the curl was observed.

Patent applicant: Toyo Ink Manufacturing Co., Ltd. 4: Some curls 3: With curls 2: A little too much curl 1: Lots of curls, moxibustion. Goku 〔effect〕

Claims (1)

[Claims] 1. Active energy ray curing characterized by mainly comprising a monomer that essentially contains a radically polymerizable monomer obtained by esterifying a lactone adduct of an organic compound having an alcoholic hydroxyl group with acrylic acid or methacrylic acid. Gender overcoat varnish.