JP4793747B2 - Printing ink composition and method for producing the same - Google Patents

Description

The present invention relates to a printing ink composition and a method for producing the same.

  With recent advances in printing technology, beautiful printed materials have been provided. These printed materials are printed by various printing methods, but the offset printing method is widely used from the viewpoint of economy and quality. A normal offset printing method is color printing with four colors of yellow, red, indigo, and black ink, and these inks overlap to express subtle colors.

By the way, with the recent increase in interest in the environment, in the ink industry, the movement to reduce the petroleum-based solvent for ink used in the ink and replace it with vegetable oils is increasing. However, if the petroleum solvent is simply replaced with vegetable oil, the vegetable oil is less likely to penetrate the paper, and the vegetable oil is less volatile than the petroleum solvent, resulting in less stickiness due to less volatilization in the air. When printing on paper using the ink, there is a problem that blocking occurs. Therefore, studies have been made to solve these problems by improving the ink resin, but in order to improve blocking, the solubility of the ink resin in the solvent must be reduced, and so There was a problem that the gloss of the ink was lowered.

As a means for solving such a problem, there is a method of using an olefin polymer, diene polymer or liquid paraffin having a solubility parameter smaller than 19 (MPa) ^{1/2 in the} resin varnish for printing ink and compatible with the solvent component. Proposed. (For example, see Patent Documents 1 to 5)

Moreover, the method of trying to solve the said problem by introduce | transducing an ultraviolet curing technique is also proposed (for example, refer patent documents 6-8). This method uses an oily / UV fusion type hybrid ink in which the internal drying of the ink is oxidative polymerization of the oil and the surface drying is performed by UV curing, and the blocking of the obtained printed matter can be improved. However, although the methods of Patent Documents 1 to 8 can improve the blocking, there is a problem that the gloss is remarkably lowered when the ink is printed several times. Further, in the case of oily / UV fusion type hybrid ink using ultraviolet curing, a new ultraviolet irradiation device has to be installed, which has a problem in economy.

Japanese Patent Laid-Open No. 2002-3770 JP 2002-155227 A JP 2002-226754 A JP 2003-147253 A JP 2003-176437 A Japanese Patent Laid-Open No. 11-228899 JP 2001-123100 A JP 2003-64288 A

An object of this invention is to provide the printing ink composition which can improve blocking resistance drastically, without reducing the glossiness of the printed matter at the time of overprinting using the conventional printing apparatus.

As a result of intensive studies to solve the above-mentioned problems, the present inventor has previously incorporated a (meth) acrylic acid ester having glycidyl (meth) acrylate and / or an alicyclic epoxy group to provide a resin varnish for printing ink. It has been found that the above problems can be solved by preparing an ink composition by adding an oxidation polymerization catalyst (e) after preparing the composition .

At present, the mechanism of the development of blocking resistance is not always clear, but a varnish for printing ink containing vegetable oil has glycidyl (meth) acrylate and / or an alicyclic epoxy group in the presence of an oxidation polymerization catalyst ( It is thought that by making meth) acrylic acid ester act, hydroxyperoxidized vegetable oil reacts with (meth) acrylic acid ester having these epoxy groups to form a harder film that is polymerized between vegetable oils. In addition to improving the blocking resistance, the friction resistance of the ink is also improved. In addition, the gloss during overprinting tends to worsen if the solubility of the resin varnish for printing ink decreases, and acrylic monomers used in commonly known UV curable inks have low solubility in the resin varnish. Therefore, while the gloss is lowered, the glycidyl (meth) acrylate and / or the (meth) acrylate ester having an alicyclic epoxy group used in the present invention causes a decrease in the solubility of the resin varnish for printing ink. Therefore, it is considered that the gloss during overprinting does not decrease. The present invention has been completed based on such findings.

That is, the present invention relates to a resin for printing ink (a), a vegetable oil (b), a petroleum-based solvent for ink (c), and (meth) acrylic acid having a glycidyl (meth) acrylate and / or an alicyclic epoxy group. A printing ink composition obtained by adding an oxidation polymerization catalyst (e) after preparing a resin varnish composition (A) for printing ink containing an ester (d), and comprising glycidyl (meth) acrylate and / or Or the printing ink composition which does not contain the photopolymerizable initiator characterized by containing 1-15 weight% of (meth) acrylic acid ester (d) which has an alicyclic epoxy group ; Resin for printing ink (a) , A vegetable oil (b) and a resin ink for printing ink containing (meth) acrylic acid ester (d) having glycidyl (meth) acrylate and / or an alicyclic epoxy group A printing ink composition obtained by adding an oxidative polymerization catalyst (e) after preparing a varnish composition (A ′), and having a glycidyl (meth) acrylate and / or an alicyclic epoxy group (meta ) relates to printing ink compositions containing no photopolymerizable initiator, characterized in that it contains 1 to 15 wt% of acrylic acid ester (d).

According to the present invention, in particular, a printing ink composition that can drastically improve the blocking resistance without reducing the gloss of printed matter when overprinted using a conventional printing device (especially an oil-based offset printing device). Can be provided. The printing ink composition according to the present invention is used as an offset printing ink such as offset sheet-fed ink (sheet-fed ink), offset rotary ink (off-wheel ink), waterless offset ink, etc. It is also suitably used for letterpress printing inks and gravure printing inks. Note that the printing ink according to the present invention using a petroleum solvent having a boiling point of 200 ° C. or more and an aromatic hydrocarbon content of 1% by weight or less as an ink solvent is suitable in terms of environment and work hygiene. Further, a printing ink designed by using vegetable oil alone without using an ink solvent is more preferable.

As the printing ink resin (a) (hereinafter referred to as component (a)) used in the present invention, various known ones can be used without particular limitation. Specifically, for example, rosin-modified phenolic resins mainly composed of rosins, resol-type phenol resins and polyols; alkyd resins containing fatty acids, polybasic acids and polyols as components; oil-free alkyd resins; JP 2001-139670 A, JP 2001-233949 A, JP 2001-233947 A, JP 2001-310934 A, JP 2002-97232 A, JP 2003-96172 A, JP 2003-2003 A. No. 105071, Japanese Patent Application Laid-Open No. 2004-18619, etc. Polyester resin and modified petroleum resin; C5 petroleum resin comprising C5 fraction, C9 petroleum resin comprising C9 fraction, DCPD petroleum comprising dicyclopentadiene (DCPD) Examples of conventionally known resins for printing inks such as resinsIn order to bring the emulsification characteristics and viscoelastic characteristics of the ink into a practical range, the physical properties of these printing ink resins include those having a carboxyl group, an acid value of about 5 to 50 mg KOH / g, and a molecular weight of about 10,000 to 400,000. As a resin design, it is preferable to adjust the ratio of the equivalent number OH of alcoholic hydroxyl groups and the equivalent number COOH of carboxyl groups to usually be about OH / COOH = 0.5 to 1.5. In this invention, 1 type can be used individually among the said various types, and 2 or more types can also be used together suitably. In particular, from the viewpoint of a good balance of ink performance, rosin-modified phenol resins, JP-A Nos. 2001-139670, 2001-233949, 2001-233947, 2001-310934, It is preferable to use a polyester resin or a modified petroleum resin described in JP-A-2002-97232, JP-A-2003-96172, JP-A-2003-105071, JP-A-2004-18619, and the like.

As the vegetable oil (b) (hereinafter referred to as component (b)) used in the present invention, various known ones can be used without particular limitation. Specifically, for example, flaxseed oil, tung oil, safflower oil, dehydrated castor oil, soybean oil and other vegetable oils, flaxseed oil fatty acid methyl, soybean oil fatty acid methyl, flaxseed oil fatty acid ethyl, soybean oil fatty acid ethyl, flaxseed oil Examples include monoesters of the above vegetable oils such as fatty acid propyl, soybean oil fatty acid propyl, linseed oil fatty acid butyl, soybean oil fatty acid butyl, and the like. These may be used alone or in combination of two or more. In these, the vegetable oil which has an unsaturated bond in a molecule | numerator from the point of the drying property of printed matter is preferable, and soybean oil is especially preferable from the point with a small load with respect to an environment.

As the petroleum-based solvent for ink (c) used in the present invention (hereinafter referred to as the component (c)), a conventionally known ink solvent can be used without any particular limitation. Specifically, for example, various petroleum solvents manufactured by Nippon Oil Corporation, such as No. 0 solvent, No. 4 solvent, No. 5 solvent, No. 6 solvent, No. 7 solvent, AF No. 4 solvent, AF No. 5 solvent, AF6 No. Solvent, AF7 Solvent and the like. These may be used alone or in combination of two or more. In particular, it is preferable to use an AF solvent having a boiling point of 200 ° C. or more and an aromatic hydrocarbon content of 1% by weight or less from the viewpoint of environmental measures. In addition, by using the component (c), setting properties and blocking resistance can be improved. However, when a printing ink with reduced environmental load is required, the component (b) is not used but the component (c) is not used. May be used.

The (meth) acrylic acid ester (d) (hereinafter referred to as the component (d)) having glycidyl (meth) acrylate and / or an alicyclic epoxy group used in the present invention is not particularly limited and may be a known one. Can be used. Specifically, for example, glycidyl (meth) acrylate having an alicyclic epoxy group-containing (meth) acrylates (e.g., trade name Cyclomer, manufactured by Daicel Chemical Industries, Ltd., etc.),, etc. can be mentioned. These may be used alone or in combination of two or more. Among these components (d), glycidyl (meth) acrylate and (meth) acrylate having the alicyclic epoxy group are particularly preferably used from the viewpoint of availability.

  As the oxidation polymerization catalyst (e) (hereinafter referred to as component (e)) used in the present invention, a known catalyst can be used without limitation. Specific examples include metal salts of carboxylic acids such as octylic acid, stearic acid, naphthenic acid, and soybean oil fatty acid with metals such as cobalt, manganese, iron, zinc, and calcium. These may be used alone or in combination of two or more. Of these, cobalt salts and manganese salts of carboxylic acids are preferred from the viewpoint of good drying properties.

As the components (a) to (e), rosin-modified phenolic resin, component JP-A No. 2001-139670, JP-A No. 2001-233949, JP-A No. 2001-233947, JP-A No. 2001 are used as the component (a). -310934, JP-A-2002-97232, JP-A-2003-96172, JP-A-2003-105071, JP-A-2004-18619 and the like are used. (B) component is soybean oil and / or soybean oil monoester, component (c) is not used, component (d) has glycidyl (meth) acrylate and / or alicyclic epoxy group as component ( When (meth) acrylate is used and cobalt salt or manganese salt of carboxylic acid is used as component (e), ink properties Excellent, preferable since it produced ink in consideration to environmental hygiene.

  The amount of the components (a) to (e) used in the present invention is particularly limited as long as the component (d) is contained in an amount of about 1 to 15% by weight based on the printing ink composition. However, the amount used of the component (a) in the printing ink is generally about 10 to 40% by weight, and the amount of the component (b) used is 10 to 10% by weight. About 70, when the component (c) is used, the amount used is about 1 to 60% by weight, the amount used of the component (d) is about 1 to 15% by weight, and the amount used of the component (e) is 0.5. What is necessary is just about 5 wt%. The component (d) is particularly preferably used in an amount of 1 to 10% by weight based on the printing ink composition. When the amount of the component (d) used is less than 1% by weight, the blocking resistance of the printing ink according to the present invention is not exhibited, and when it is used more than 15% by weight, the resin varnish and the printing ink are stored. In addition to deterioration of stability, it is not preferable because it becomes elastomeric when used in the production of a resin varnish composition.

The printing ink composition containing no photopolymerizable initiator of the present invention contains the components (a) to (e), but various known additives may be added as necessary. Examples of additives include gelling agents, pigments (yellow, red, indigo, black, etc.), vegetable oils and / or petroleum-based solvents similar to those described above, as well as ink flowability and ink surface coating. Surfactant, wax, etc.

Examples of the gelling agent include various known ones such as aluminum octylate, aluminum stearate, aluminum triisopropoxide, aluminum tributoxide, aluminum dipropoxide monoacetyl acetate, aluminum dibutoxide monoacetyl acetate, and aluminum triacetyl acetate. Things can be used without any particular limitation.

The printing ink composition of the present invention can be produced by the following method. As a method for preparing the printing ink composition of the present invention, the resin varnish composition for printing ink (A) (hereinafter referred to as the component (A)) containing the components (a) to (d), or ( a), (b) and (d) resin for a printing ink varnish composition comprising components (A') (hereinafter, (A') after preparation of that component), is how the addition of component (e) can give.

To those the (A) is Ingredients (a) ~ component (d), the (A') Ingredient is (a), to (b) and component (d), if necessary, and a gelling agent, Ink solvents other than the components (b) and (c) are blended, heated to about 100 to 240 ° C., and dissolved or chemically reacted. In addition, (b) component, (c) component, gelling agent, and ink solvents other than (b) and (c) components all inhibit the reaction when producing the resin composition for printing ink. If it does not, if these components are used at the time of manufacture of (a) component and it is made to remain in (a) component, the manufacturing process of the resin varnish for printing ink can be simplified. In addition, after adding a component (d), it is preferable to heat at 220 degrees C or less. When heating to a temperature higher than 220 ° C., the effect of improving the blocking property may not appear. The component (A) or the component (A ′) thus obtained is added with the component (e) and, if necessary, the above-mentioned additives, and a known ink manufacturing apparatus such as a roll mill, a ball mill, an attritor, or a sand mill is added. The printing ink composition of the present invention is obtained by kneading and preparing the ink so as to have an appropriate ink constant.

Hereinafter, the present invention will be described more specifically with reference to production examples and examples, but the present invention is not limited thereto. Hereinafter, “parts” means parts by weight.

Production Example 1: (Production of 70% resol-type nonylphenol xylene solution)
In a reaction vessel equipped with a stirrer, a reflux condenser with a water separator and a thermometer, 1,000 parts of nonylphenol, 270 parts of paraformaldehyde and 1,000 parts of water were charged, and the temperature was raised to 50 ° C. with stirring. Then, 100 parts of sodium hydroxide was added at 50 ° C., and the temperature was gradually raised to 90 ° C. while cooling, and then kept warm for 2.5 hours, and sulfuric acid was added dropwise to adjust the pH to around 6. Thereafter, 150 parts of xylene was added, the aqueous layer containing formaldehyde and the like was removed, and the contents were cooled to obtain a 70% xylene solution of resol-type nonylphenol.

Production Example 2: (Production of unsaturated acid-modified rosin)
In a reaction vessel similar to Production Example 1, 1,000 parts of gum rosin was charged, and the mixture was heated to 180 ° C. and melted while stirring in a nitrogen atmosphere. Next, 267 parts of fumaric acid was charged, and the temperature was raised to 230 ° C. with stirring and kept for 1 hour, followed by cooling to obtain a solid resin of unsaturated acid-modified rosin. The resin acid value was 342.0 (according to JIS K5601. Hereinafter, the acid value is a value measured by the same method).

Production Example 3: (Production of polar group-containing petroleum resin)
In a reaction vessel similar to Production Example 1, 1,000 parts of DCPD petroleum resin (trade name Quinton 1325, manufactured by Nippon Zeon Co., Ltd.) and 100 parts of xylene were charged, and the mixture was stirred up to 150 ° C. in a nitrogen atmosphere. It heated up and melted. Next, 70 parts of maleic anhydride was charged, and 6 parts of di-t-butyl peroxide (trade name: Perbutyl D, manufactured by Nippon Oil & Fats Co., Ltd.) was continuously added over 30 minutes. The reaction was kept for 5 hours. After the temperature is maintained, the reaction system is heated to 200 ° C. to remove xylene, depressurized at 0.02 MPa for 10 minutes, and then cooled to obtain a solid resin having a theoretical acid value of 75.0 and a weight average molecular weight of 5,000. Got. In addition, the said theoretical acid value is computed from the carboxyl group equivalent number of the raw material to be used. In addition, the measurement of the said weight average molecular weight used the gel permeation chromatography (brand name HLC-8020) by Tosoh Corporation, and the column (brand name TSK-GEL) by Tosoh Corporation (henceforth, a weight average molecular weight). Is a value measured by the same method).

Production Example 4: (Synthesis of printing ink resin a-1)
In a reaction vessel similar to Production Example 1, 552 parts of gum rosin was charged, and the mixture was heated to 230 ° C. and stirred while stirring in a nitrogen atmosphere. Subsequently, 52 parts of pentaerythritol and 2 parts of zinc oxide were added, the temperature was raised to 260 ° C. with stirring, and the reaction was continued until the acid value became 20 or less. After further cooling to 230 ° C., 394 parts of a 70% xylene solution of resole-type nonylphenol obtained in Production Example 1 (276 parts of solid content) in the temperature-retaining state was brought into the system over a period of 4 hours within a temperature range of 230 to 260 ° C. It was dripped. After completion of the dropwise addition, the 33 wt% linseed oil viscosity was adjusted to 8.0 Pa · s, the pressure was reduced at 0.02 MPa for 10 minutes, and then the contents were cooled to obtain a printing ink resin a-1. In addition, the tolerance of the aromatic hydrocarbon solvent (trade name: No. 0 Solvent H, manufactured by Nippon Oil Corporation) of the resin composition is 1.4 g / g, the acid value is 16.8, and the softening point is 168. The weight average molecular weight was 92,000. Here, the 33% linseed oil viscosity is the viscosity measured at 25 ° C. using a cone and plate viscometer made by Nippon Rheology Equipment Co., Ltd. with a mixture of resin and linseed oil heated in a 1 to 2 weight ratio. (Hereinafter, 33% linseed oil viscosity is a value measured by the same method). The tolerance (solubility index) is the total solvent required until the solution and No. 0 solvent H are heated and mixed at a 1 to 1 weight ratio and further added to No. 0 solvent H at 25 ° C to become cloudy. It is a value calculated from the resin weight relative to the weight (hereinafter, tolerance is a value measured by the same method). The softening point is based on JIS K5601 (hereinafter, the softening point is a value measured by the same method).

Production Example 5: (Synthesis of printing ink resin a-2)
420 parts of the polar group-containing petroleum resin obtained in Production Example 3 was charged in the same reaction vessel as in Production Example 1, and the mixture was heated to 200 ° C. with stirring in a nitrogen atmosphere and melted. Next, 58 parts of octadecylamine was added and kept at 200 ° C. for 2 hours, and then 348 parts of polymerized rosin (trade name: Silvatac 140, manufactured by Silvachem, acid value 140) and the unsaturated acid-modified rosin obtained in Production Example 2 124 parts were charged and melted. Thereafter, 25 parts of pentaerythritol and 25 parts of glycerin were added to start the esterification reaction, and the temperature was raised to 260 ° C. with stirring. Thereafter, when the acid value of the resin was 30 or less, 1 part of paratoluenesulfonic acid was charged, and the esterification reaction was continued until the acid value was 20 or less. After completion of the reaction, the reaction system was adjusted so that the 33 wt% linseed oil viscosity was 8.0 Pa · s, the pressure was reduced at 0.02 MPa for 10 minutes, and then the contents were cooled to obtain a resin a-2 for printing ink. It was. The tolerance of the aliphatic hydrocarbon solvent (trade name: 0 Solvent H, manufactured by Mitsubishi Oil Corporation) of the resin composition for printing ink thus obtained was 1.2 g / g, the acid value was 14.3, The softening point was 172 ° C. and the weight average molecular weight was 140,000.

Example 1: (Preparation of printing ink resin varnish composition A-1 and printing ink composition)
43 parts of printing ink resin a-1 which is component (a) obtained in Production Example 4, 30 parts of soybean oil which is component (b), alicyclic hydrocarbon solvent which is component (c) (commodity) Name AF solvent 6 (manufactured by Nippon Oil Corporation) and 2 parts of glycidyl acrylate as component (d) were mixed and dissolved at 180 ° C. for 1 hour to obtain a varnish. After cooling this varnish to 60 ° C., 0.5 to 1.5 parts of aluminum chelate (trade name: ALCH, manufactured by Kawaken Fine Chemical Co., Ltd.) is added, and the temperature is raised to 190 ° C. and kept warm for 1 hour. Resin varnish composition A-1 for printing ink was obtained. Subsequently, using the resin varnish composition for printing ink obtained by the above method, using a three roll mill at the blending ratio shown in Table 1, the meat thickness is 9.0 ± 0.5, the flow value is 19. The printing ink composition according to the present invention was obtained by appropriately adjusting to 0 ± 1.0. The content of glycidyl acrylate in the printing ink is 1.3% by weight.

Example 2: (Preparation of resin varnish composition A-2 for printing ink and printing ink composition)
43 parts of printing ink resin a-2 which is component (a) obtained in Production Example 5, 30 parts of soybean oil which is component (b), and alicyclic hydrocarbon solvent which is component (c) Name AF solvent 6 (manufactured by Nippon Oil Co., Ltd.) 23 parts and component (d) glycidyl methacrylate 4 parts were mixed and dissolved at 180 ° C. for 1 hour to obtain a varnish. After cooling this varnish to 60 ° C., 0.5 to 1.5 parts of aluminum chelate (trade name: ALCH, manufactured by Kawaken Fine Chemical Co., Ltd.) is added, and the temperature is raised to 190 ° C. and kept warm for 1 hour. Resin varnish composition A-2 for printing ink was obtained. Subsequently, using the resin varnish composition for printing ink obtained by the above method, using a three roll mill at the blending ratio shown in Table 1, the meat thickness is 9.0 ± 0.5, the flow value is 19. The printing ink composition according to the present invention was obtained by appropriately adjusting to 0 ± 1.0. The content of glycidyl methacrylate in the printing ink is 2.9% by weight.

Example 3 (Preparation of resin varnish composition A′-1 for printing ink and printing ink composition)
40 parts of resin a-2 for printing ink which is component (a) obtained in Production Example 5, 39 parts of soybean oil which is component (b) and alicyclic epoxy group which is component (d) (meta ) 21 parts of acrylate (trade name Cyclomer, manufactured by Daicel Chemical Industries, Ltd.) were mixed and dissolved at 180 ° C. for 1 hour to obtain a varnish. After cooling this varnish to 60 ° C., 0.5 to 1.5 parts of aluminum chelate (trade name: ALCH, manufactured by Kawaken Fine Chemical Co., Ltd.) is added, and the temperature is raised to 190 ° C. and kept warm for 1 hour. Resin varnish composition A′-1 for printing ink was obtained. Subsequently, using the resin varnish composition for printing ink obtained by the above method, using a three roll mill at the blending ratio shown in Table 1, the meat thickness is 9.0 ± 0.5, the flow value is 19. The printing ink composition according to the present invention was obtained by appropriately adjusting to 0 ± 1.0. In addition, content of the (meth) acrylate which has an alicyclic epoxy group in the said printing ink is 15 weight%.

Comparative Example 1: (Preparation of resin varnish composition for printing ink and printing ink composition)
A printing ink composition was prepared in the same manner as in Example 3 , except that 60 parts of soybean oil as component (b) was used and component (d) was not used.

Comparative Example 2: (Preparation of resin varnish composition for printing ink and printing ink composition)
A printing ink composition was prepared in the same manner as in Example 3 except that 59 parts of soybean oil as component (b) and 1 part of (meth) acrylate having an alicyclic epoxy group as component (d) were used. Prepared. In addition, content of the (meth) acrylate which has an alicyclic epoxy group in the said printing ink is 0.8 weight%.

Comparative Example 3: (Preparation of resin varnish composition for printing ink and printing ink composition)
A resin varnish for printing ink was prepared in the same manner as in Example 3 except that 36 parts of soybean oil as component (b) and 24 parts of (meth) acrylate having an alicyclic epoxy group as component (d) were used. As a result, the ink performance test was stopped because the resin varnish became elastomeric. When a printing ink composition was prepared for reference, the content of (meth) acrylate having an alicyclic epoxy group in the printing ink was 17% by weight.

Comparative Example 4: (Preparation of resin varnish composition for printing ink and printing ink composition)
A printing ink composition was prepared in the same manner as in Example 3 , except that 57 parts of soybean oil as component (b) and 3 parts of trimethylolpropane triacrylate were used.

Comparative Example 5: (Preparation of resin varnish composition for printing ink and printing ink composition)
A printing ink composition was prepared in the same manner as in Example 3 , except that 57 parts of soybean oil and 3 parts of polybutadiene (trade name: Polybutadiene B2000, manufactured by Shin Nippon Oil Co., Ltd.) were used.

(Ink performance test)
Single-printing gloss: 0.27 ml of ink was developed on art paper with an RI tester (manufactured by Ishikawajima Industrial Machinery Co., Ltd.), then 25 ° C., 50% R.D. H. For 24 hours, and the reflectivity at 60 ° -60 ° was measured with a gloss meter. The larger the numerical value, the better the gloss. The results are shown in Table 2.
Glossy impression for two times printing: 0.27 ml of ink was developed on art paper with an RI tester (manufactured by Ishikawajima Sangyo Co., Ltd.), 0.27 ml of ink was further developed on the color surface, then 25 ° C., 50% R. H. For 24 hours, and the reflectivity at 60 ° -60 ° was measured with a gloss meter. The larger the numerical value, the better the gloss. The results are shown in Table 2.
Blocking resistance: The color developed surfaces of the color developed product after the double-printing gloss measurement were overlapped and a load was applied with a blocking tester at 25 ° C., 50% R.D. H. The degree of blocking after standing for 24 hours was visually determined, and the evaluation results are shown in Table 2.
5: No blocking at all, 4: Slightly peels off the developed color surface, 3: Intermediate between 2 and 4, 2: Peels off the developed color surface in a wide range, 1: Removes the developed color surface in a wide range

The printing ink composition according to the present invention (Examples 1 to 5) has a double-printing gloss which is equal to or higher than that of a single-printing gloss, and more resistant than the system (Comparative Example 1) which does not use the component (d). The blocking property can be greatly improved. In contrast, the system having a low content of component (d) (Comparative Example 2) does not exhibit blocking resistance, and the system having a high content of component (d) (Comparative Example 3) has a resin varnish composition for printing ink. The product became elastomeric. Further, in the system using trimethylolpropane triacrylate (Comparative Example 4) and the system using a polybutadiene having a solubility parameter smaller than 19 (MPa) ^1/2 (Comparative Example 5), the blocking resistance is improved, but twice. It can be seen that the printed gloss is remarkably deteriorated.

Claims (2)

Contains printing ink resin (a), vegetable oils (b), petroleum-based solvent for ink (c), and (meth) acrylic acid ester (d) having glycidyl (meth) acrylate and / or alicyclic epoxy groups A printing ink composition obtained by adding an oxidation polymerization catalyst (e) after preparing a resin varnish composition (A) for printing ink, and comprising glycidyl (meth) acrylate and / or an alicyclic epoxy group The printing ink composition which does not contain the photopolymerization initiator characterized by containing 1-15 weight% of (meth) acrylic acid ester (d) which has NO. Resin varnish composition for printing ink containing resin (a) for printing ink, vegetable oil (b) and (meth) acrylic acid ester (d) having glycidyl (meth) acrylate and / or alicyclic epoxy group ( A ′) is a printing ink composition obtained by adding an oxidation polymerization catalyst (e), and is a (meth) acrylic acid ester having (meth) acrylate glycidyl and / or an alicyclic epoxy group A printing ink composition containing no photopolymerizable initiator, wherein 1 to 15% by weight of (d) is contained.