JPH041275A - Actinic radiation curable overcoating varnish - Google Patents

Abstract

PURPOSE:To obtain the title varnish which brings about a very rare ruled line crack and is excellent in curling resistance by using a monomer including a specific radical-polymerizable monomer as an essential component. CONSTITUTION:An actinic radiation curable overcoating varnish mainly comprises a monomer including a radical-polymerizable monomer which is obtained by an esterification reaction of an alkylene oxide adduct, such as an ethylene oxide adduct, of bisphenol F or hydrogenated bisphenol F with acrylic acid or methacrylic acid as an essential component.

Description

Detailed Description of the Invention (Objective of the Invention) (Industrial Application Field) The present invention relates to an active energy ray-curable overcoat varnish. The present invention relates to an active energy ray-curable overcoat face 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. These active energy ray overcoat varnishes are often used with a varnish of several tens of voids or less, preferably a few voids or less, at room temperature to ensure sufficient coating suitability. Therefore, the active energy ray-curable oat coat varnish is mainly composed of a low-viscosity radically polymerizable monomer, and optionally contains a polymerizable prepolymer resin and various additives (slip agent, antifoaming side). Furthermore, when the active energy ray is ultraviolet rays, a radical polymerization initiator is used.

Conventionally, commercially available monomers which are (meth)acrylic esters with alcohols as radical polymerizable monomers 1 For example, monofunctional acrylates such as methyl (meth)acrylate alkyl alcohol (meth)acrylate, neopentyl glycol, di(meth)acrylate, Bifunctional acrylates such as di(meth)acrylate of bisphenol A and ethylene oxide adducts, trifunctional acrylates such as trimethylolpropane tri(meth)acrylate,
Tetrafunctional acrylates such as pentaerythritol tetra(meth)acrylate, hexafunctional acrylates such as dipentaerythritol hexa(meth)acrylate, and the like have been used. However, when these radically polymerizable monomers are used in an active energy ray-curable overcoat face, the coating film has poor flexibility and creases in ruled lines occur after post-processing for paper carton production. 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. Problems have arisen, and the actual situation is that the scope of application of these active energy ray-curable overprint faces has been narrowed.

[Structure of the invention]

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

That is, the present invention provides an active energy ray-curable monomer that essentially contains a radically polymerizable monomer obtained by esterifying bisphenol F or an alkylene oxide adduct of hydrogenated bisphenol F with acrylic acid or methacrylic acid. It's an overcoat festival.

When the monomer according to the present invention is represented by a general formula, (in the formula,
X is a residue of bisphenol F or hydrogenated bisphenol F, R1 is an alkylene group having 2 to 4 carbon atoms, and n is 1
An integer of ~10, R2 represents a hydrogen atom or a methyl group. ). - The monomer represented by (1) can be produced by a conventional method, and one example of the production method will be described below.

Bisphenol F or hydrogenated hisphenol F and sodium hydroxide (approximately 0.5% by weight) were charged into an autoclave equipped with a thermometer, nitrogen gas introduction device, alkylene oxide introduction device, and stirring device, and while stirring, alkylene oxide ( 1 to 10 mol per hydroxyl group of bisphenol F or hydrogenated bisphenol F) is gradually introduced and reacted, and after the reaction is completed, stirring is continued until the gauge pressure becomes 0.1 kg/ad or less to allow the reaction to occur. The obtained adduct is placed in a four-hole flask equipped with a stirrer, and further reacted with (meth)acrylic acid. The reaction catalyst is about 1% by weight of P-)luenesulfonic acid, and the polymerization inhibitor is hydroquinone or the like. Further, as the refluxing solvent, about 5 to 10% by weight of cyclohexane is used. It is obtained by reacting at 80 to 100° C. for about 15 hours while blowing air, and when the acid value becomes 5 or less, the solvent is removed and pumped out.

The number of moles of alkylene oxide added is preferably 2 to 20 moles per mole of bisphenol F or hydrogenated bisphenol F.

The reaction amount of acrylic acid or methacrylic acid is about -1.1 to 0.9 of the carboxyl group of (meth)acrylic acid/the hydroxyl group of bisphenol F or hydrogenated bisphenol F-alkylene oxide adduct.

In addition, it is possible to mix and use the monomer represented by (1) with other commercially available monomers, and the ratio is 100/O.
A range of ~10/90 is possible. Preferably 100/
0 to 25/75, and if the monomer represented by -shipping CI) is less than this ratio, the effect 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, hengein methyl ether, henzoin ethyl ether, henzoin isopropyl ether, α-chlorohenzoin, α-acrylichenzoin, benzoin-based sensitizers such as Irgacure 184 (manufactured by Ciba Geigi), benzophenone, p-methylbenzophenone, p-chlorohensiphenone, methyl 0-hendiylbenzoate, acetophenone, etc. Ketone sensitizers, dialkylaminoarylketone sensitizers such as isoamyl p-dimethylaminobenzoate and p-dimethylaminoacetophenone, and polycyclic carbonyl sensitizers such as thioxanthone, xanthone and their halogen-substituted products. Irgacure 907 (manufactured by Ciba Geigi) can be used alone or in an appropriate combination.

These photo-enhancing agents 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 1 200 parts of bisphenol F, 2 parts of sodium hydroxide, and 176 parts of ethylene oxide were placed in a small autoclave equipped with a thermometer, nitrogen gas introduction device, alkylene oxide introduction device, and stirring device, and the system was replaced with nitrogen gas while stirring. Then, the reaction was gradually carried out at 160°C and 5 kg/ctJ. Gauge pressure after completion of reaction: 0, 1 kg
/ Stir until it is below cni! ! The reaction took 30 minutes.

74.3 parts of the obtained adduct, 25.7 parts of acrylic acid, 0.1 part of hydroquinone, p-toluenesulfone ta 1
, 0 parts of cyclohexane and 10 parts of cyclohexane were reacted at 100° C. for 15 hours while blowing air in a four-hole flask equipped with a stirrer, and when the acid value reached 5.7, the solvent was removed and pumped out. The obtained low molecular weight unsaturated compound is referred to as monomer A.

Production Example 2 212 parts of hydrogenated bisphenol F, 220 parts of propylene oxide, and 2 parts of sodium hydroxide were reacted in the same manner as in Production Example 1. 76.8 parts of the obtained adduct, 23.2 parts of methacrylic acid, 0.1 part of hydroquinone, 1.0 part of p-toluesulfonic acid, and 10 parts of cyclohexane were reacted in the same manner as in Production Example 1, and after 13 hours, the acid Since the value reached 5, the solvent was removed and pumped out. This is called monomer B.

Production Example 3 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 four-hole flask equipped with a stirrer, and reacted at 100° C. while blowing air. After about 15 hours, when the acid value reached 1, it was pumped out. The obtained product is designated as resin C.

Examples Using the radically polymerizable monomers prepared in Production Examples 1 and 2,
An active energy ray overcoat varnish was prepared. Note that comparative examples are also shown in Table 1.

The active energy ray-curable Oha Coto varnish shown in Table 1 was applied to Hokuetsu Alli Coat (coated ball made by Hokuetsu Paper Co., Ltd.) and NK.
Coated on piece art (coated paper made by Nippon Kako Paper) with a bar coater, Example samples 1 to 2, Comparative example samples 1 to 2.
Regarding 2, 50 m/10 [under the high-pressure mercury lamp (ozone type) l lamp with an intensity of 120 W/crn.
It was placed on a conveyor and irradiated to cure it.

Further, Example Sample 3 and Comparative Example Sample 3 were cured by irradiation of 10 Mrad using a curtain beam type electron beam irradiation device.

The results regarding ruled line cracking and low curl permeability of each of the obtained coating films are shown below.

Ruled line cracking: The coated and cured Hokuetsu alicoated paper was folded 180' with the coated side facing up and the degree of cranking of the coated layer was observed using a 50x magnifying glass.

〔evaluation〕

5: No crank 4: Slightly cranked 3: With crank 2: Slightly many cranks 1: Many cranks Low curl permeability: The curl state of the coated and cured NK piece art paper was observed.

〔evaluation〕

5: No curl Paper 4: Slight curl 3: Curl 2: Slightly curl 1: A lot of curl Curling ≦ Ji (Effect) The active energy ray-curable overcoat face of the present invention does not cause creases in ruled lines as in the examples. It also has extremely low curling properties and can widen the range of applications of active energy ray-curable overcoat faces.

Patent applicant: Toyo Ink Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. Active energy rays characterized by being mainly composed of a monomer that essentially contains a radically polymerizable monomer obtained by esterifying bisphenol F or an alkylene oxide adduct of hydrogenated bisphenol F with acrylic acid or methacrylic acid. Hardening overcoat varnish.