JPH10204324A - Active radiation-curing coating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a active radiation-curing coating agent having good flowability, actinive radiation-curability and dispersion stability, by mixing a varnish with an inorganic oxide and a specified amount of an ethylene oxide- modified bisphenol A diacrylate having an ethylene oxide chain of a specified length. SOLUTION: This agent is prepared by adding at least 5wt.% radical- polymerizable monomer of the formula to a varnish containing 2-98wt.%, based on the total weight of the agent, inorganic oxide. Only in the region in which n+m=8-25 in the formula, the agent shows a low viscosity and can contain a large amount of an inorganic oxide. The monomer having radical- polymerizable double bond in the varnish may contain e.g. methyl (meth)acrylate in addition to the monomer of the formula. When the active radiation is ultraviolet light, the agent contains a radical polymerization initiator as a photosensitizer. The inorganic oxide used is exemplified by calcium oxide, silicon oxide, phosphorus oxide, titanium oxide or lanthanum oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating agent for active energy ray-curable inorganic oxide-dispersed inks, paints and the like. The present invention relates to an active energy ray-curable inorganic oxide-dispersed coating material which can be cured by irradiation with ultraviolet rays or electron beams, and has excellent printability.

[0002]

2. Description of the Related Art In recent years, studies on inorganic oxide dispersion coatings which are cured by active energy rays have been actively conducted. For example, an inorganic light-emitting powder such as an active energy ray-curable magnetic coating agent containing a magnetic iron oxide powder as a main component and a monomer having a radical polymerizable double bond (radical polymerizable monomer), and a rare earth oxide compound powder. There are an active energy ray-curable luminescent coating material containing a radical polymerizable monomer as a main component and an active energy ray-curable ceramic coating material containing a radical polymerizable monomer mainly containing a ceramic powder mainly composed of an inorganic oxide. Many of these materials can bring out the high performance so that the inorganic oxide powder can be formulated at a high concentration in order to bring out the physical characteristics such as the magnetic properties and the light emission characteristics of each inorganic oxide powder. .

In order to obtain an active energy ray-curable (inorganic oxide powder-dispersed) coating agent, the radical polymerizable monomer used in the varnish includes, as well as the curing properties associated with active energy ray irradiation, In many cases, a monomer having a role is used. For this purpose, ethylene oxide-modified bisphenol A diacrylate (o + p = 4 in the general formula 2) has been frequently used for this purpose.

[0004]

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When this is used for an active energy ray-curable coating material, it is possible to provide properties such as high-speed curability and dispersion stability of powder obtained by irradiation with active energy rays and extremely small curing shrinkage. . However, if the amount of the varnish containing the compound of the general formula 2 is reduced in order to formulate the inorganic oxide powder at a high concentration, the appropriate fluidity required as a coating agent is impaired. Therefore, there has been a problem how to form a varnish capable of increasing the concentration of the inorganic oxide powder while maintaining the fluidity, dispersion stability, curability to active energy rays, and the like of the coating agent.

[0006]

The present invention has been made as a result of intensive studies to improve these drawbacks. As a result, it has been found that inorganic oxide powders are formulated in a high concentration, and that good fluidity, active energy ray curing properties and good properties are obtained. We have invented a varnish structure having excellent dispersion stability.

[0007]

That is, the present invention relates to an inorganic oxide-dispersed coating composition in which the inorganic oxide is 2 to 98% by weight based on the total weight of the coating composition.
An active energy ray-curable coating agent containing 5% by weight or more of the radical polymerizable monomer represented by the formula (3) with respect to the total varnish weight, and furthermore, the inorganic oxide is 25 to 90% by weight of the total weight of the coating agent. % In the varnish and the general formula 1
Is an active energy ray-curable coating agent containing 30% by weight or more of the radical polymerizable monomer represented by the formula (1) based on the total varnish weight.

[0008]

Embedded image

When the radical polymerizable monomer of the general formula 1 is used for a coating agent having a high concentration of an inorganic oxide (powder), the coating is performed only in a region where the number of m + n in the formula is m + n = 8 to 25. The agent exhibits a low viscosity and can increase the content of inorganic oxide in the coating agent. Further, it exhibits good curability with irradiation of active energy rays such as ultraviolet rays and electron beams. Further, the dispersion stability as an inorganic oxide powder dispersion coating agent is also good. M + n number in the general formula 1 is
In the region other than m + n = 8 to 25, the viscosity of the coating increases, and the content of the inorganic oxide that can be formulated in the coating is limited. The inorganic oxide used in the present invention includes alkaline earth oxides including calcium oxide, group IIIb oxides including aluminum oxide, group IVb oxides including silicon oxide, and phosphorus oxide. Vb group oxides, titanium oxide, transition metal oxides including iron oxide, etc., rare earth oxides including lanthanum oxide, powders and the like, each of which may be in a mixed state, Further, a material in which a small amount of another composition is mixed in an inorganic oxide such as an alkali or alkaline earth metal salt in glass powder may be used. Further, these powders and the like may be used as a mixture with other types of powders such as metal powders, inorganic nitrides, organic substances, and carbon black as long as the effects of the present invention are not impaired.

The content of the inorganic oxide is 2 to 98% by weight, preferably 15 to 95% by weight, more preferably 25 to 90% by weight based on the total weight of the coating agent. As the monomer having a radical polymerizable double bond in the varnish used in the present invention, a monomer other than the general formula 1 may be used in combination. Monomers that can be used in combination are 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) acrylate,
Penzyl (meth) acrylate, (meth) acrylate of alkylphenol oxide adduct of alkylphenol,
Monofunctional monomers such as cyclohexyl (meth) acrylate can be mentioned. Further, difunctional or higher functional monomers such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and polyethylene glycol di (meth) ) Acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (nota) acrylate, tripyrylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, pentyl glycol ( Meth) acrylates,
Neopentyl glycol di (meth) acrylate, hydroxypiparyl hydroxypivalate di (meth) acrylate, hexanediol di (meth) acrylate,
(Di) glycerin tri (meth) acrylate, diglycerin alkylene oxide tetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane alkylene oxide tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, ditri Methylolpropane alkylene oxide tetra (meth) acrylate, trimethylolethane tri (meth) acrylate, ditrimethylolethane tri (meth) acrylate, trimethylolethane alkylene oxide tri (meth) acrylate, ditrimethylolethane alkylene oxide tetra (meth) acrylate, tetra Methylol methanetetra (meth) acrylate, dipentaerythritol hexa (meth) acryle , Bisphenol A alkylene oxide di (meth) acrylate, pisphenol F alkylene oxide di (meth) acrylate, dihydroxybenzene alkylene oxide di (meth) acrylate, trihydroxypentene alkylene oxide di (meth) acrylate, Examples thereof include (meth) acrylate, water-added bisphenol F di (meth) acrylate, water-added bisphenol A alkylene oxide adduct di (meth) acrylate, and water-added bisphenol F alkylene oxide adduct di (meth) acrylate. Further, a lactone adduct monomer is also included. That is, polyethylene glycol polylactonate di (meth) acrylate,
Polypropylene glycol polylactonate di (meth)
Acrylate, alkylene glycol polylactonate di (meth) acrylate, glycerin polylactonate tri (meth) acrylate, diglycerin polylactonate tetra (meth) acrylate, trimethylolpropane polylactonate tri (meth) acrylate, ditrimethylolpropanetetra One acrylate of each polyol lactonate such as (meth) acrylate, pentaerythritol polylactonate tetra (meth) acrylate, and dipentaerythritol polylactonate hexaacrylate.

The varnish used in the present invention may contain an inert resin and / or a resin having a radically polymerizable double bond, if necessary, in addition to the radically polymerizable monomer. As these resins, acrylic resin, polyurethane resin, polyvinyl resin, polyester resin, polyether resin, polycarbonate resin,
Polyethylene resin, polypropylene resin, polyolefin resin, polystyrene resin, polyamide resin, polyimide resin, epoxy resin, alkyd resin, etc., and their halogenated resins, and / or so that they have a radical polymerizable double bond. Modified resins (eg, polyurethane acrylate, polyether acrylate), and the like.

In the use of the inorganic oxide dispersion coating 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). Benzoin sensitizers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, α-acrylbenzoin, benzophenone, p-methylbenzophenone, p-chlorobenzophenone, tetrachlorobenzophenone, o-benzoyl benzoate Aryl ketone sensitizers such as methyl and acetophenone; dialkylamino aryl keto such as dialkylaminoacetophenones such as 4,4-bisdiethylaminobenzophenone, isoamyl p-dimethylaminobenzoate and p-dimethylaminoacetophenone System sensitizers, thioxanthone, polycyclic carbonyl-based sensitizers such as xanthone and its halogen substituents and the like, may be used by these alone or in appropriate combination. These photosensitizers are desirably in the range of 0.5 to 15% by weight in the coating material.

In order to obtain the active energy ray-curable coating composition of the present invention, an inorganic oxide is dispersed in the varnish. The method is not particularly limited, and the dispersion may be performed by a conventional method such as a three-roll mill or a ball mill. Method. In addition to the inorganic oxide, an organic solvent, a plasticizer, a surfactant, a thermal polymerization inhibitor and the like can be added as necessary. In the coating composition of the present invention, the inorganic oxide is 2 to 98% by weight, preferably 25 to 90% by weight, based on the total amount of the coating composition,
As a varnish from which inorganic oxides were removed, 5
-100% by weight, preferably 10-98% by weight, more preferably 30-95% by weight.

In the use of the inorganic oxide-dispersed coating agent of the present invention, the printing method is not particularly limited, and printing can be performed by a method such as offset printing, gravure printing, screen printing, flexographic printing, or the like. Further, the coating method is not particularly limited, and the coating can be performed by a coating method using a roll coater, a curtain coater, a knife coater, or the like. Hereinafter, the present invention will be described with reference to specific examples. All parts in the examples are parts by weight based on the total coating weight.

[0015]

EXAMPLES Printing of coatings was performed by screen printing. Electron beam irradiation is Curetron EB of Nissin High Voltage
Performed using C-200. The ultraviolet irradiation was performed using a meta-halar lamp using a Tosuka UV irradiation device manufactured by Toshiba Lighting & Technology Corporation. To cure the coating, the coating was printed on polyethylene-coated paper with an RI tester, and after irradiation with active energy rays, the printed surface was rubbed with a cotton cloth to check for peeling. The viscosity was measured using an E-type viscometer. For dispersion stability, the coating was left in the dark for one month to see if it had separated or solidified.

In the following, the formulation of the coating agent and the results obtained by using the coating agent are shown in the respective tables.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

[Table 3]

[0020]

[Table 4]

[0021]

[Table 5]

[0022]

[Table 6]

FIG. 1 shows the dependency of the viscosity of the coating agent on the number of m + n in the general formula 1, as shown in the results 1, 2 and 3 in the table.

[0024]

The active energy ray-curable coating composition of the present invention has good fluidity and curing properties for active energy rays, even when an inorganic oxide is formulated at a high concentration, as compared with conventionally known coating compositions. Since good dispersion stability can be obtained, it is possible to easily increase the inorganic material concentration on the printed surface obtained by printing, and to provide a good printed matter that can easily bring out the physical properties inherent to inorganic oxides. it can.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the viscosity of a coating agent and the number of m + n monomers of Formula 1.

Claims (2)

[Claims] 1. The inorganic oxide is used in an amount of from 2 to 98 based on the total weight of the coating agent.
An active energy ray-curable coating, characterized in that the varnish contains 5% by weight or more of the radical polymerizable monomer represented by the general formula 1 with respect to the total weight of the varnish in the inorganic oxide dispersion coating agent having a weight percentage of 10% by weight. Agent. Embedded image 2. The inorganic oxide is used in an amount of 25 to 90% by weight of the total weight of the coating agent.
% Of the varnish and 30% by weight of the radical polymerizable monomer represented by the general formula 1 based on the total weight of the varnish.
The active energy ray-curable coating material according to claim 1, which contains the above.