JPS5942709B2 - Shigaisenkou Kagata Insatsuinki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing ink that hardens and dries rapidly by irradiation with ultraviolet rays, and more specifically, a diepoxy compound having two epoxy groups in the prisoner molecule, (B) an unsaturated monoglycidyl compound, ( C) an unsaturated dibasic acid, (D) an unsaturated monobasic acid, and (E) a higher fatty acid in a molar ratio of epoxy group/carboxyl group in all reaction components of 0.8 to 1.2, and A photopolymerizable unsaturated epoxy ester resin obtained by simultaneously reacting five components from 8 to (E) within a specific molar ratio of each reaction component, or this photopolymerizable unsaturated epoxy ester resin. It is an ultraviolet curable printing ink whose main component is an isocyanate-modified photopolymerizable unsaturated epoxy ester resin that has been reacted with an isocyanate compound to adjust its viscosity and hydroxyl value.

Conventionally, in printing by lithographic offset printing, letterpress printing, etc., drying oils, semi-drying oils, high boiling point solvents, resins, etc. are used as vehicles for printing inks. It takes a long time from several minutes to several hours for drying due to oxidative polymerization due to absorption of oxygen, especially for printing materials with non-absorbent surfaces such as aluminum foil, metal plates, and plastic films. Since there is no set drying, an extremely long drying time of several hours to over ten hours is required, and heat-set off-wheel printing and metal plate printing require a large amount of space, equipment costs, and energy for a heat drying oven.

Furthermore, most of the heat-set types cause many problems such as air pollution and environmental hygiene because they diffuse solvents into the atmosphere.

The present invention has been made in order to improve the various drawbacks that occur when using such conventionally known printing inks, and it does not require the use of large amounts of organic solvents, and it does not require the use of a heat drying oven, which requires high equipment costs and costs. The object of the present invention is to provide an ultraviolet curable printing ink that can be dried extremely easily and quickly by ultraviolet irradiation without the use of ultraviolet rays.

As a composition that hardens rapidly by ultraviolet irradiation, a reaction product of an epoxy resin prepolymer and an ethylenically unsaturated acid such as atarylic acid or metatallylic acid (β-hydroxyesteno(iii) and a specific photopolymerization initiator) is used. A composition consisting of the following is described in Japanese Patent Publication No. 44-19038.

Further, an ultraviolet curable printing ink containing a mixture of such a β-hydroxy ester and an ethylenically unsaturated monomer as a main component has also been proposed. (Unexamined Japanese Patent Publication No. 49-21205).
However, such β-hydroxy ester has very poor fluidity, and since carboxyl groups are bonded to both ends of the epoxy compound, it cannot be expected to increase the molecular weight. Since it does not have an unsaturated group having , it has the disadvantage of poor curability.

In order to improve these drawbacks, β, which is composed of polyepoxide and α,β-monoethylenically unsaturated monocarboxylic acid, has been proposed.
- A photopolymerizable composition consisting of a small amount of a mixture of polyitaconate consisting of a hydroxyester, a polyoxide, and itaconic acid (Japanese Patent Application Laid-open No. 18989/1989), or a partially or mostly saturated polymerizable unsaturated monobasic acid. Alternatively, an unsaturated epoxy ester obtained by reacting an acid component substituted with an unsaturated polybasic acid with an epoxy compound (Japanese Patent Publication No. 45
-40.069) is known.

However, with these unsaturated epoxy esters, the degree of crosslinking can be adjusted, the molecular weight can be increased to a certain extent, and the curing properties are slightly improved, but the reaction product has a very high viscosity, and in some cases, synthesis There is a risk of gelation occurring during the reaction, so it is necessary to add an organic solvent or polymerizable monomer as a diluent during synthesis, or to add a solvent or polymerizable monomer to the reaction product. The drawback was that the viscosity had to be adjusted. The use of such solvents or polymerizable monomers significantly reduces workability during synthesis reactions or curing, and also reduces the curing properties of the reaction products. In particular, when a solvent is used, it evaporates and produces a bad odor. It also causes so-called solvent pollution, such as deterioration of the working environment. In addition to these, low-viscosity unsaturated epoxy esters include the reaction product of a mixed epoxy resin of a low molecular weight epoxy resin and a high molecular weight epoxy resin with acrylic acid or methacrylic acid (Japanese Patent Laid-Open No. 49-99592), An unsaturated epoxy ester resin composition comprising a mixture of a reaction product of an epoxy compound and acrylic acid or methacrylic acid and a reaction product of a monoepoxy compound and acrylic acid or methacrylic acid (JP-A-50-3327
No. 9) is also known.

These resin compositions can be synthesized in a one-step reaction, and they do not necessarily require solvents or polymerizable monomers during synthesis or curing, and are excellent in terms of workability, but they have high molecular weight. curability is still insufficient. Furthermore, these β
- When hydroxyesters or unsaturated epoxy ester resins are used as vehicles for printing inks, they have poor affinity with pigments and cannot maintain the appropriate consistency, elasticity, fluidity, etc. for the ink. However, printed matter also lacks gloss, and it is difficult to dissolve in the hydrocarbon-based cleaning solvents conventionally used in printing operations, so ketone, aromatic, and ester-based solvents have to be used. However, these solvents also have the disadvantage that conventional printing equipment cannot be used as is because they damage the rubber rollers, blankets, and even the printed areas of the offset plate.

Furthermore, cured products of curable compositions of these β-hydroxy esters and unsaturated epoxy ester resins have poor flexibility and are therefore unsuitable for use as printing ink compounds. As a method for improving the flexibility of this β-hydroxy ester, a composition in which a portion of the α,β-monounsaturated carboxylic acid of the β-hydroxy ester is replaced with a higher fatty acid has been reported. However, since these have a high viscosity, it is necessary to mix polymerizable monomers, and flexible, low-viscosity compositions are made by reacting addition-polymerizable unsaturated monoepoxy compounds with fatty acids. A composition in which a polyisocyanate compound is reacted with an addition-polymerizable unsaturated ENTEL compound obtained by Furthermore, since the composition contains a very large amount of fatty acids relative to the polymerizable unsaturated groups, the curability is insufficient. As a composition used in a vehicle for ultraviolet curable printing ink, it has excellent curability, low volatility, resin viscosity can be adjusted arbitrarily, and when made into an ink, it provides appropriate consistency and stability and has excellent printability. In addition, it is necessary to have excellent properties after curing.

The present inventors have completed the present invention as a result of intensive studies aimed at synthesizing a photopolymerizable resin composition and producing an ultraviolet curable printing ink that fully satisfies these conditions.

That is, the present invention provides a diepoxy compound having two epoxy groups in the prisoner molecule, (B) an unsaturated monoglycidyl compound, (C) an unsaturated dibasic acid, (D) an unsaturated monobasic acid, and (E) a higher The molar ratio of fatty acids to epoxy groups/carboxyl groups in all the reaction components is from -0.8 to 1.2, and (4) and (B) in the reaction components having epoxy groups ((B)) are about 10 mol% or more and about 30 mol% or more, respectively, and reaction components having carboxyl groups [(C), (9
), (C) in (E)]. (])) and (E) by reacting the five components (4) to (b)) at the same time in a range of about 10 mol% or more, about 40 mol% or more, and about 15 mol% or more, respectively. The resulting photopolymerizable unsaturated epoxy ester resin, or the isocyanate-modified photopolymerizable unsaturated epoxy ester resin whose viscosity and hydroxyl value have been adjusted by further reacting the photopolymerizable unsaturated epoxy ester resin with an isocyanate compound, is used as a varnish. This is an ultraviolet curable printing ink whose main component is

According to the present invention, organic hot printing or polymerizable monomers are not necessarily required during resin synthesis reactions, ink production, or printing, resulting in excellent workability and the ability to obtain The molecular weight, resin liquid viscosity, and hydroxyl value of the resin can be freely adjusted, and since it has a highly reactive polymerizable group in the main chain, it has excellent photocurability, and the resin itself has a high Because it has a molecular weight, the amount of volatile components mixed in is extremely low and almost no odor is generated.

Furthermore, since it has a higher fatty acid group in its molecule, it has good affinity with pigments and sufficient printability, and the film after curing is glossy and highly flexible. Furthermore, it has excellent properties such that ordinary hydrocarbon solvents can be used for cleaning after processing, and conventional printing equipment can be used as is. The present invention will be explained in detail below.

In the present invention, the diepoxy compounds having two epoxy groups in the molecule are saturated or unsaturated aliphatic, cycloaliphatic, aromatic, or heterocyclic polyepoxides, such as epichlorohydrin or methylepichlorohydrin. Diglycidyl-type epoxy compounds synthesized by reaction with bisphenol A, resorcinol, oxybenzoic acid, m-hydroxyaniline, glycols, etc., which have two or more epoxy groups in the molecule. All can be used.

The unsaturated monoglycidyl compound (B) is a monoepoxy compound such as glycidyl acrylate, glycidyl metatarylate, allyl glycidyl ether.

The proportion of (4) in the reaction components having these epoxy groups is about 10 mol% or more, and the proportion of (8) is about 30 mol%.
That's all.

Unsaturated dibasic acids (O refers to common alpha, beta monounsaturated dibasic acids such as maleic acid, halogenated maleic acid, itaconic acid, halogenated itaconic acid, fumaric acid, citraconic acid, etc.).

Unsaturated monobasic acids (auto) include acrylic acid, methacrylic acid,
Tarotonic acid, etc.

Higher fatty acids (8) include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, eleostearic acid, etc., or animal and vegetable oil fatty acids containing these.

Isocyanate compounds include monoisocyanate compounds such as methyl isocyanate and phenyl isocyanate, and
, 4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-xylylene diisocyanate, 2,6-xylylene diisocyanate, lysine diisocyanate, diphenylmethane-4,4'-diisocyanate , diisocyanate compounds such as hexamethylene diisocyanate, and other polyinocyanate compounds.

The proportion of (C) in the reaction components having these carboxyl groups is about 10 mol% or more, and the proportion of (D) is about 40 mol%.
The proportion of the above and (E) is about 15 mol% or more.

In the present invention, each of the above components may be used alone or as a mixture of two or more.

The photopolymerizable unsaturated epoxy ester resin in the present invention is (4) an epoxy compound having two or more epoxy groups in the molecule, (B) a saturated or unsaturated monoglycidyl compound, (C) an unsaturated dibasic acid, ( D) unsaturated monobasic acid, (
Although it is obtained by simultaneously reacting higher fatty acids, the molar ratio of all carboxyl groups to all epoxy groups in all reaction components must be in the range of 0.8 to 1.2.

If it is less than 0.8, unreacted epoxy groups will have a negative effect on the stability and toxicity of the resin, and if it is more than 1.2, unreacted carboxylic acid will remain and the stability of the ink will be affected. unsuitable in terms of quality and printability.

Furthermore, the method for synthesizing the photopolymerizable unsaturated epoxy resin is extremely easy, and each raw material is charged into a reactor in the raw material ratio specified in the present invention, and if necessary, a tertiary compound such as triethylamine is added. Catalysts such as amines, quaternary ammonium hydroxide, quaternary salts such as tetramethylammonium chloride,
Further, as a polymerization inhibitor, phenols such as para-methoxyphenol and para-cresol, amines such as hydroquinones, naphthylamines, quinones such as benzoquinone, etc. are used in arbitrary amounts, and the polymerization is carried out at an appropriate temperature under stirring, preferably at 50°C. It is manufactured by carrying out a heating reaction in the range of ~150°C. It is sufficient to track the reaction by acid value. By arbitrarily selecting the compositional molar ratio under such reaction conditions, it is not only possible to freely control the molecular weight, but also to obtain a liquid with any viscosity depending on the purpose of use.

Furthermore, by reacting the photopolymerizable unsaturated epoxy ester resin obtained by this method with an inocyanate compound, the viscosity of the resin is increased and at the same time, the hydroxyl value is reduced, resulting in a resin with better offset printing suitability. It can be a composition.

The amount of isocyanate compound to be reacted is determined based on 1 mole of 0H groups of the photopolymerizable unsaturated epoxy ester resin.
It is appropriate to use the O group in a range of 0.1 to 1.0 mol. This reaction is carried out by gradually dropping an inocyanate compound into a photopolymerizable unsaturated epoxy ester resin, preferably at a temperature of 7°C or less, so that the free isocyanate groups are reduced to 0,2
0I) or less. The ultraviolet curable printing ink of the present invention is the photopolymerizable unsaturated epoxy ester resin thus obtained or the isocyanate-modified photopolymerizable resin obtained by further reacting the photopolymerizable unsaturated epoxy ester resin with an isocyanate compound. It is obtained by mixing and kneading a polyunsaturated epoxy ester resin as the main component of the varnish with conventionally used colorants such as organic pigments, inorganic pigments, extender pigments, and dyes.

It is desirable that the temperature at this time does not exceed 60'C. Of course, in this case, there is no problem in using a mixture of the isocyanate-modified and unmodified photopolymerizable unsaturated epoxy esters, and it goes without saying that the use of such a mixture is included in the present invention. At this time, an ultraviolet polymerization initiator such as a benzoin polymerization initiator, a halogenated sulfonyl polymerization initiator, a quinone polymerization initiator, a benzophenone polymerization initiator, a ketone polymerization initiator, etc.
Add 5% by weight.

Furthermore, if necessary for the preparation of the ink, other compounding agents such as polymerizable monomers, solvents, animal and vegetable oils, various resins, and waxes may be added and used in combination.

It can also be used as a transparent varnish that does not contain colorants. The present invention will be explained in detail below using synthesis examples and examples. Synthesis Example 1 Sumiepoxy ELA-128 (manufactured by Sumitomo Chemical Co., Ltd., bisphenol epoxy resin) 0.5 mol, glycidyl acrylate 1.5 mol, itaconic acid 0.6 mol, acrylic acid 0.9 mol and anoleic acid fatty acid 0.5 mol. 4 mol was charged into an 11 Flanuco equipped with a stirrer, reflux condenser and thermometer, heated on an oil bath and reacted at 70-11'C.

Tetramethylammonium chloride was used as a catalyst at a weight ratio of 0.5% based on the total reaction raw materials, and methylhydroquinone was used at 500 ppm as a polymerization inhibitor. The reaction time reached 95.1% in 7.5 hours. The obtained photopolymerizable unsaturated epoxy ester resin (cooked 1) had a color count of 5 on the Cardner color meter.
~6 and the viscosity is approximately 350 Stokes (temperature 25~C)
It was hot. Synthesis Example 2 The reaction was carried out in exactly the same manner as in Synthesis Example 1 except that glycidyl methacrylate was used in place of glycidyl acrylate in Synthesis Example 1. The reaction time was 7.5 hours and the reaction rate was 95.
．． It reached 6%.

Obtained photopolymerizable unsaturated epoxy ester resin (?2)
was 5 to 6 on a Cardner color meter, and the viscosity was about 280 Stokes (temperature 25°C). Synthesis Example 3 The reaction was carried out in exactly the same manner as in Synthesis Example 1 except that oleic acid was used in place of the oleic acid in Synthesis Example 1. The reaction time reached 95.0 (Ft) in 7.5 hours. .

Obtained photopolymerizable unsaturated epoxy ester resin (?3)
was 6 to 7 on a Cardner color meter, and the viscosity was about 300 Stokenes (temperature 25 to 25°C). Synthesis Example 4 A reaction was carried out in exactly the same manner as in Synthesis Example 1 except that fumaric acid was used in place of itaconic acid in Synthesis Example 1. The reaction rate reached 95.30/) in 7.5 hours.

Obtained photopolymerizable unsaturated epoxy ester resin (cooked 4)
was 5 to 6 on a Cardner color meter, and the viscosity was about 350 Stokes (temperature 25°C). Synthesis example 5 Sumiepoxy ELA-1280.3 mol, Denacol E
X-810 (ethylene glycol type epoxy resin manufactured by Nagase Sangyo Co., Ltd.) 0.5 mol, glycidyl acrylate 0
．． When 4 mol of itaconic acid, 0.4 mol of acrylic acid, 0.8 mol of acrylic acid, and 0.4 mol of anoil fatty acid were reacted in the same manner as in Synthesis Example 1, the reaction time was 8.0 hours and the reaction rate was 97.0%.
reached.

Obtained photopolymerizable unsaturated epoxy ester resin (?5)
was 6 to 7 on a Cardner color meter, and the viscosity was about 230 Stokes (temperature 257C). Synthesis Example 6 Synthesis Example 1: 0.2 mol of Sumiepoxy ELA-128, 1.6 mol of glycidyl arylate, 0.2 mol of itaconic acid, 1.2 mol of acrylic acid, and 0.4 mol of linseed oil fatty acid.
When the reaction was carried out in the same manner as above, the reaction time reached 95.4% in 7.5 hours.

The obtained photopolymerizable unsaturated epoxy ester resin (cooked 6 mm was 5 to 6 on the Cardner color meter, and the viscosity was about 10 stotas (temperature 255 C).
While keeping the temperature at ℃, a dropping load was attached to the flask and tolylene divinocyanate (80% of 2.4 isomer, 2.
6 isomer 20(!)) is gradually added dropwise over about 0.5 to 1.0 hours while being careful to avoid heat generation.

After that, the reaction was continued for about 3 hours while maintaining the temperature at about 50°C, and the number of free isocyanate groups was 0.20! ) or less, the reaction was terminated. The obtained resin (?6-a) had a color number of 5 to 6 on a Cardner color meter and a viscosity of about 280 Stokes (at a temperature of 25°C). Synthesis Example 7 0.3 mol of Sumiepoxy ELA-128, 1.4 mol of glycidyl acrylate, 0.2 mol of itaconic acid, 1.1 mol of acrylic acid, and 0.5 mol of anoil fatty acid were reacted in the same manner as in Synthesis Example 1. The reaction time was 8.0 hours, and the reaction rate reached 95.6 (!).

The resulting photopolymerizable unsaturated epoxy ester resin 7 had a viscosity of 4 to 5 on the Cardner color meter and a viscosity of about 18 Stokes (at a temperature of 25 DEG C.). Further, while keeping the temperature of this resin at about 5°C, 0.27 mol of hexamethylene diycinocyanate was added dropwise in the same manner as in Synthesis Example 6 to cause a reaction. The obtained resin (boiled 71a) has a viscosity of 4 to 5 on the Cardner color meter, and a viscosity of about 450 Stokes (temperature 25 to C).
). Synthesis example 8 Sumie epoxy ELA-1280
．． When 2 mol of glycidyl acrylate, 1.6 mol of itaconic acid, 1.3 mol of acrylic acid, and 0.3 mol of anoleic acid were reacted in the same manner as in Synthesis Example 1, the reaction time was 8.0 hours. A reaction rate of 96.30I) was reached.

The resulting photopolymerizable unsaturated epoxy ether resin solution 8 had a value of 4 to 5 on the Cardner color meter, and a viscosity of about 14 nutox (at a temperature of 25°C). Furthermore, this resin is heated to about 5'C
0.27 mol of tolylene diisocyanate was added dropwise to the mixture while keeping it warm in the same manner as in Synthesis Example 6, and the mixture was allowed to react.

The obtained resin (?8-a) has a color number of 4 to 5 on the Cardner color meter.
The viscosity was approximately 300 Stokes (temperature 25°C). Synthesis Example 9 Using 0.3 mol of Sumiepoxy ELA-128, 0.9 mol of glycidyl acrylate, 0.3 mol of itaconic acid, 0.8 mol of acrylic acid, and 0.3 mol of linseed oil fatty acid,
When the reaction was carried out in the same manner as in Synthesis Example 1, the reaction time was 8.
The reaction rate reached 96.5 (f/) at 0 hours.

The obtained photopolymerizable unsaturated epoxy ester resin (.11
). No. 9) had a color number of 6 to 7 on a Cardner color meter, and a viscosity of about 280 strokes (temperature 25° C.). Synthesis example
10 Using 0.4 mol of Sumiepoxy ELA-128, 0.8 mol of glycidyl arylate, 0.4 mol of fumaric acid, 0.4 mol of acrylic acid and 0.2 mol of linseed oil fatty acid,
When the reaction was carried out in the same manner as in Synthesis Example 1, a reaction rate of 95.001) was reached in a reaction time of 8.0 hours.

The obtained photopolymerizable unsaturated epoxy ether resin (▲10
) is 6 to 7 on the Cardner color meter, and the viscosity is about 32
It was 0 stroke (temperature 25-C).

Comparative synthesis example 11 Sumiepoxy ELA-1281.0 mol, acrylic acid 2
．． When 0 mol was reacted in the same manner as in Synthesis Example 1, the reaction time reached 97.0% in 6.0 hours.

Furthermore, trimethylolpropane triacrylate 0.6
mol was added to terminate the reaction. Resin obtained (Rei 11)
The viscosity was about 250 Stokes (temperature 25°C).
Comparative synthesis example 12 Sumiepoxy ELA-1280.8 mol, acrylic acid 1
．． When 0 mol and 0.6 mol of linseed oil fatty acids were reacted in the same manner as in Synthesis Example 1, the reaction time was 7.0 hours and the reaction rate was 9.
It reached 6.5%.

Furthermore, trimethylolpropane triacrylate 0.2
mol was added to terminate the reaction. Resin obtained (boiled 12)
The viscosity was about 280 Stokes (temperature 25°C). Comparative synthesis example 13 Glycidyl acrylate 1.0 mol, linseed oil fatty acid 1
．． When 0 mol was reacted in the same manner as in Synthesis Example 1, the reaction time reached 98.0% in 3.0 hours.

The temperature was further cooled to 70° C. or lower, and 0.3 mol of tolylene diyinocyanate was added dropwise to react in the same manner as in Synthesis Example 6. The resulting Resin Black 13 had a viscosity of about 300 Nutox (temperature: 25 C). Example 1 Isocyanate-modified photopolymerizable unsaturated epoxy ester resin E. 6
-a- Boiled 8-a and Resin Boiled 9 to Boiled 11 obtained in Comparative Synthesis Examples 9 to 11 are 3609, respectively, and 909 of Phthalocyanine Blue is added thereto as a pigment, and thoroughly mixed with a triple roll at 60°C or less. Grind the meat.

Benzophenone 309 and Michler's Ketone 209 were mixed as ultraviolet polymerization initiators to prepare respective ultraviolet curable printing inks. 0.1 each of the resulting ink
5cc was applied to art paper using a RI tester roll and immediately exposed to a high-pressure mercury lamp (80W/CrlL) manufactured by Iwasaki Electric Co., Ltd.
The speed required for the ink to be completely cured was measured by changing the speed of the conveyor using an ultraviolet irradiation device.

Furthermore, using each ink, an offset sheet-fed one-color press (
Printing was performed using a PS plate under normal printing conditions using a Color Metal Co., Ltd. model name: Pearl), and an interlocked ultraviolet irradiation device (Oak Co., Ltd. ozone-less type high-pressure mercury lamp 2).
The printability and ultraviolet curing performance were compared using the following methods.

Claims (1)

[Scope of Claims] 1 (A) a diepoxy compound having two epoxy groups in the molecule, (B) an unsaturated monoglycidyl compound, (C)
An unsaturated dibasic acid, (D) an unsaturated monobasic acid, and (E) a higher fatty acid in a molar ratio of epoxy group/carboxyl group in all reaction components of 0.8 to 1.2 and having an epoxy group. (A) and (B) in the reaction components are each about 10 mol%
and about 30 mol% or more, and (C), (D), and (E) in the reaction component having a carboxyl group are about 10 mol% or more, about 40 mol% or more, and about 15 mol% or more, respectively. 1. An ultraviolet curable printing ink characterized in that the main component of the varnish is a photopolymerizable unsaturated epoxy ester resin obtained by simultaneously reacting in the following range. 2 (A) Diepoxy compound having two epoxy groups in the molecule, (B) Unsaturated monoglycidyl compound, (C)
Unsaturated dibasic acid, (D) unsaturated monobasic acid, (E) higher fatty acid, epoxy group/carboxyl group in all reaction components = 0
．． 8 to 1.2, and (A) and (B) in the reaction component having an epoxy group are about 10 mol% or more and about 30% or more, respectively, and in the reaction component having a carboxyl group. (C), (D) and (E) are each about 10
The photopolymerizable unsaturated epoxy ester resin obtained by simultaneously reacting in a range of mol % or more, about 40 mol % or more, and about 15 mol % or more is further reacted with an isocyanate compound to improve the viscosity and hydroxyl value. An ultraviolet curing printing ink characterized by having a prepared isocyanate-modified photopolymerizable unsaturated epoxy ester resin as the main component of the varnish.