JPH037771A - Photocurable coating compositions and printing ink compositions - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing an ethylenic double bond-containing compound, specific compound, thoxanthone (derivative) and specified compound and useful as printing inks, photoresist materials, etc. CONSTITUTION:The objective composition containing (A) a compound having ethylenic double bond (e.g. methyl acrylate or acrylated epoxy resin), (B) a compound (e.g. p-morpholino-2,2-dimethyl-2-diethylaminoacetophenone) expressed by formula I (R<1> to R<3> are H, 1-6C alkyl or alkoxy; R<4> is H, 1-6C alkyl, alkoxy or phenyl) as a photoinitiator, (C) thioxantone or a derivative thereof substituted with a 1-3C alkyl, 1-3C alkoxy or halogen and (D) a compound (e.g. 4,4'- bisdiethylaminobenzophenone) expressed by formula II (R<5> and R<6> are 1-3C alkyl; R<7> is 1-13C alkyl, phenyl or formula III) as a sensitizer.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention is directed to curing of a photopolymerizable compound having an ethylenic double bond by ultraviolet rays using a combination of a photoinitiator and a photosensitizer. , relates to more rapid photocurable coating compositions and printing ink compositions.

(Prior art) In order to cure a radically polymerizable compound by irradiating it with ultraviolet rays, it is necessary that a photoinitiator generates active radicals, and these radicals sufficiently react with a compound having an ethylenic double bond. be. For this reason, U.S. Patent No. 4.017.6
As shown in No. 52, it is known to use an aromatic carbonyl compound that can change to an excited state upon irradiation in combination with a photosensitizer.

Further, JP-A No. 60-84248 discloses a photopolymerizable composition containing a photoinitiator, thioxanthone, and its derivatives, and JP-A No. 61-54064 discloses a photopolymerizable composition containing 4.4
``A photopolymerizable composition containing bis(diethylamino)benzophenone and 4-dialkylaminoacetophenone (however, the alkyl group is a methyl group or an ethyl group) was disclosed in JP-A No. 5
5-89365, 2,2-dimethoxy-2-
Photopolymerizable compositions containing phenylacetophenone and P-dimethylaminoacetophenone or 4,4'-bis(diethylamino)benzophenone are known, but they are insufficient in terms of curing speed to meet more stringent requirements. There was nothing that could be done. Also, JP-A-63-150
Publication No. 303 discloses a combination of a photoinitiator and a titanocene compound, but this titanocene compound is colored and has the property of decolorizing when irradiated with ultraviolet rays, so it is difficult to use in light-colored inks. The disadvantage is that it cannot be used.

(Problems to be Solved by the Invention) As described above, the combination of a photoinitiator and a photosensitizer speeds up the curing of a compound having an ethylenic heavy bond. In addition, printing inks are used for these purposes, but the curing speed of the film and the physical properties of the cured film when irradiated with ultraviolet rays do not necessarily depend on the type of pigment used, pigment concentration, coating thickness, amount of ultraviolet irradiation, etc. There was no satisfactory combination.

On the other hand, in printing, high-density printed matter has become required, and this has led to the problem of slow curing speed due to increased pigment concentration and print film thickness2, and the need for faster printing speeds. There are increasingly strict requirements.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a photocurable coating composition for solving the above problems. That is, the present invention
(a) Compounds having an ethylenic double bond (b) Compounds represented by the general formula [I] (wherein Rl, R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy (R4 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group, or a phenyl group.) (C) Thioxanthone or an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a thioxanthone derivative substituted with a halogen atom, and (d) a compound h represented by the following general formula (II) (wherein R5 and R6 are an alkyl group having 1 to 3 carbon atoms, R1 is an alkyl group having 1 to 13 carbon atoms, It's something to be excited about.

In the present invention, component (a) is composed of a compound having one or more types of ethylenic double bonds. Those containing a mixture of two or three types of compounds having ethylenic double bonds are preferred. Compounds having ethylenic double bonds are those having one or more ethylenic double bonds and are monomers, oligomers and/or prepolymers.

Examples of monomers with ethylenic double bonds are alkyl- or hydroxyalkyl-acrylates or monomethacrylates, such as methyl-, ethyl-
, butyl-92-ethylhexyl or 2-hydroxyethyl acrylate; isobornyl acrylate; methyl- or ethyl methacrylate. Other examples include acrylonitrile, acrylamide, methacrylamide N-substituted (meth)acrylamides, vinyl esters of vinyl acetate, vinyl ethers such as isobutyl vinyl ether; styrene; alkyl and halogenated styrenes; N-vinylpyrrolid.

The present invention provides a photocurable coating composition characterized in that it contains vinyl chloride or vinylidene chloride.

Examples of monomers with multiple double bonds are ethylene glycol, propylene glycol-neopentyl glycol, hexamethylene glycol-3 or bisphenol-A-diacrylate; 4,4'-bis(2
-acryloyloxyethoxy)-diphenylpropane; trimethylolpropane triacrylate; pentaerythritol-triacrylate or -tetraacrylate; vinyl acrylate; divinylbenzene: divinyl succinate; diallyl phthalate; triallyl phosphate; triallyl isocyanurate or tris( 2-acryloyloxyethyl) isocyanurate;
These include dipentaerythritol-hexaacrylate, pentaacrylate, or triacrylate.

Agents for compounds with multiple ethylenic double bonds of oligomers or prepolymers are acrylated epoxy resins, acrylated polyethers, acrylated polyurethanes or acrylated polyesters. Other examples of unsaturated oligomers are unsaturated polyester resins, often made from maleic acid, phthalic acid, and one or more diols, and having a molecular weight of about 500 to 3000.

Oligomers with such double bonds can also be referred to as prepolymers.

Binary mixtures of prepolymers and polymers with multiple ethylenic double bonds or ternary mixtures which additionally contain oligomers are often used.

Since in this case the prepolymer primarily determines the properties of the coating film, by changing the prepolymer it is possible to change the properties of the cured film.

The monomer acts as a reactive diluent and the viscosity is lowered by this monomer without the use of solvents.

Such two components and three components based on prepolymers
The component compositions are used in printing inks, paints, photoresists or other photocurable materials.

In the photocurable coating composition according to the present invention, the photoinitiator is a compound (b) represented by the general formula [I], and specifically p-morpholino-2,2-dimethyl-2-diethylamino p-morpholino-2, such as acetophenone,
2-dialkyl-2-sialkylaminoacetophenone.

Thioxanthone and its derivatives (c) include thioxanthone, 2-methylthioxanthone, 2ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-promthioxanthone, 2-methoxythioxanthone, 2ethoxythioxanthone, 2
, 4-dimethylthioxanthone, 2.4-diethylthioxanthone, 2゜4-diisopropylthioxanthone,
2,4-cyclothioxanthone, 2,4-dibromothioxanthone, 2,4-dimethoxythioxanthone, 2
．． 4-diethoxythioxanthone, 2,6-diethylthioxanthone, 2,6-diethylthioxanthone.

26-diisopropylthioxanthone, 2.6 dichlorothioxanthone, 2,6-dibromothioxanthone, 2
．． 6-dimethoxythioxanthone, 2゜6-dinitoxythioxanthone, 2,7-diethylthioxanthone, 2
．． 7-diethylthioxanthone.

2,7-diisopropylthioxanthone, 2,7 dichlorothioxanthone, 2,7-dibromothioxanthone,
Compounds such as 2,7-dimethoxythioxanthone and 2°7-dinitoxythioxanthone are mentioned.

The sensitizer contains one or more compounds (d) represented by formula (II). As a specific example, 4.
4'-bisdiethylaminobenzophenone.

Examples include P-dimethylaminobenzophenone, P-diethylaminobenzophenone, P-dimethylaminoacetophenone, and P-diethylaminoacetophenone.

These component (d) sensitizers further improve the combination effect of the photoinitiators (bl and (C1)) without impairing the storage stability of the composition.

The increase in the effect is particularly noticeable when pigments with high UV absorption are used in printing inks, etc., when the pigment concentration is high, and when the coating thickness is large. Sufficient sensitization curing for agents (b) and (C) is obtained. That is, the curing speed and physical properties of the film are dramatically improved compared to conventional photocurable coating compositions.

The photocurable coating composition according to the invention can be used for many purposes.

First of all, its use is in pigments or dyeing systems, such as for example in printing inks, photographic reproduction methods, image recording methods, and for the production of relief structures, and its curing properties are less dependent on the coating thickness. Therefore, if the coating material contains pigments, the coating film thickness is large, or the coating material has a large concentration of pigments such as titanium dioxide.

Other products include photoresist materials, photocrosslinking materials used in printing plate manufacturing, photocurable microcapsules, and image recording systems or photocopy systems manufactured therefrom.

Depending on the respective purpose, the photopolymerizable coating compositions can contain other additives, such as, for example, pigments, dyes and their precursors, fillers, flow aids, thixotropic agents or wetting agents.

Other additives include 2, for example, light stabilizers, ultraviolet absorbers, antioxidants, 1 polymerization inhibitors, stabilizers such as corrosion inhibitors, and waxes that modify the film surface. In addition, excluding those that are particularly colored or 9 colored, 9 as long as it does not contradict the purpose of the present invention,
Other radical polymerization initiators or sensitizers can be used in combination.

The photocurable coating composition according to the present invention has a total weight of 10
When it is 0 parts by weight, 1 usually (a) is 10 to 99 parts by weight,
Preferably 15 to 60 parts by weight (b), (C)
and (d) in a total amount of 0.5 to 20 parts by weight, preferably 3 to 10 parts by weight. In addition, (d) is 10 to 1000% by weight, preferably 50 to 1000% by weight based on the sum of (b) and (C).
It is preferable to select from the range of 200% by weight.

The present invention will be explained below with reference to Examples. In the examples, 1 part means part by weight, and 2% means 2% by weight.

1-姶尤・Open A1: p-morpholino-2,2-diethyl 2-dimethylaminoacetophenone・Open A2: p-morpholino-2,2-diethyl 2-dimethoxyaminoacetophenone・Open A3: 2-hensyl-2 dimethylamino -1(4-
Morpholinophenyl)-butanone-1 Open B 1: 2. 4-Diethylthioxanthone・Open B2: 2-chlorothioxanthone 1 2 ・Open B3: 2-isoprobylthiogysanthone・Open C: Benzophenone (comparative example) ・Open D: 2-methyl-1-(4-methylthio) 2 -Morpholino-propanone-1 (comparative example) 1 wing, increase 1:4,4''-bis(diethylamino)-benzophenone, increase 2 dimethylaminoacetate I - phenone, increase 3:4-
Dienalaminoacet-1-phenone Example 1 A red ink is produced according to the following recipe.

Carbon black 12 parts Bisphenol A diglycidyl ether 25 parts Diacrylate Fatty acid modified polyester acrylate 25 parts Dipentaerythritol Hexaacrylate Open A1 Open B1 Increase 1 32 parts 2 parts 2 parts 2 parts with three rolls to a particle size of 3 μm or less Distribute evenly so that

Examples 2 to 4 Beni inki was produced in the same manner as in Example 1 except that the photoinitiator and sensitizer were changed to the compositions shown in Table 1.

Comparative Examples 1 to 4 Red ink was produced in the same manner as in Example 1 except that the photoinitiator and sensitizer were changed to the compositions shown in Table 1.

Using each of these printing inks, we printed on art paper with a coating amount of 30cm/100c+a and 45cm/100cal, respectively, using an R1 tester made by Mei Seisakusho.
A W high-pressure mercury lamp was used to pass a 10 cm distance on a conveyor, and the conveyor speed required to cure the coating film (it was determined that there was no fading when touched with the finger) was determined as the curing speed (m/min). The measurement results are shown in Table 1.

Margin below table 1 (% in Table 1.

The addition ratio to the photopolymerizable coating composition is shown.

)

Claims (1)

[Claims] 1. (a) A compound having an ethylenic double bond, (b) A compound represented by the general formula [I]▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] (However, in the formula R^1, R^2 and R^3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group, and R^4 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group. ), (c) thioxanthone or a thioxanthone derivative substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a halogen atom, and (d) the following general formula [II] Compounds represented by ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [II] (However, R^5 and R^6 are each independently an alkyl group having 1 to 3 carbon atoms, and R^7 is an alkyl group having 1 to 13 carbon atoms. A photocurable coating composition characterized by containing an alkyl group, a phenyl group, or ▲a mathematical formula, a chemical formula, a table, etc.). 2. A printing ink composition comprising the composition according to claim 1.