JP6063232B2 - Printing ink composition - Google Patents

Description

  The present invention relates to an ink for offset printing.

  Conventionally, offset printing inks are composed of pigments, resins, petroleum-based solvents, vegetable oils, and the like. In addition, offset printing using offset printing ink is known for various drying methods such as heat-set drying used for offset rotary printing, penetrating drying and oxidation polymerization drying used for offset sheet-fed printing and newspaper printing. In particular, the heat-set type drying uses a petroleum solvent in the offset printing ink to pass through the dryer immediately after printing to forcibly evaporate the solvent, thereby fixing the offset printing ink on the surface of the printing paper ( Set). Heat-set type offset rotary printing is the mainstream printing method at present because offset printing ink is set in a short time at a high speed. Petroleum solvents used in offset printing inks are mainly AF (aromatic-free) solvents with aromatic components kept to 1% or less, and heat set offset rotary printing requires appropriate evaporation speed and drying properties. Therefore, a solvent having a low boiling point range is used as compared with a solvent used for permeation type dry sheet printing or newspaper printing. For example, AF solvent 7 (manufactured by Shin Nippon Oil Co., Ltd.) having a boiling point range of 259 to 282 ° C. is often used for heat-set offset rotary ink. For sheet-fed printing inks, AF solvent 6 (manufactured by Shin Nippon Oil Co., Ltd.) having a boiling range of 296 to 317 ° C. and AF solvent 5 (manufactured by Shin Nippon Oil Co., Ltd.) having a boiling point range of 275 to 306 ° C. Is often used. Further, even an AF solvent contains at least a VOC component.

  Therefore, in heat-set type offset rotary printing, the solvent is evaporated and the offset printing ink is dried, so that evaporation of a volatile organic compound, so-called VOC (Volatile Organic Compound) component, occurs. In sheet-fed printing, the solvent in the offset printing ink permeates and then gradually oxidatively polymerizes to dry and adhere. However, even if the AF solvent is used, evaporation of the VOC component into the atmosphere occurs.

  In the recent printing industry, there is a demand to reduce the environmental burden by suppressing the discharge of VOC components, aromatic components and naphthenic components contained in offset printing inks. Therefore, from AF solvents to vegetable oil components that do not contain VOC components By making the conversion, there is an offset printing ink from which the VOC component has been removed. However, since the vegetable oil component has a higher viscosity than the AF solvent, the penetrability is poor and the setting property is delayed. Moreover, since the ratio of a vegetable oil component increases, since it tends to remain in printed matter, it will affect dryness. In addition, since the solvent that tends to evaporate is converted to a vegetable oil component that is difficult to evaporate, it is not possible to completely convert it to a vegetable oil component in heat-set offset rotary ink that is dried by forcibly evaporating the solvent with a dryer. However, it is realized only with the sheet-fed offset printing ink used for the osmotic drying type offset sheet-fed printing.

  At present, at the printing site for heat-set type offset rotary printing, an exhaust gas treatment device is installed to reduce VOC emissions from the dryer to reduce the environmental load, and the dryer is used to reduce the energy required for drying. While printing is performed at a temperature as low as possible, inexpensive and low-quality printing paper is being used to increase printing speed and reduce printing costs in order to improve productivity. For this reason, it has fallen into a dilemma in which the image quality of the printed matter is reduced due to stains due to poor drying, paper peeling, blanking, gloss reduction, and the like.

  Contamination due to poor drying can occur when the drying temperature of the dryer is low or the printing speed is high, and the set of offset printing ink printed on the printing paper is not sufficient and rubs in the dryer. It is transferred to the cooling roller and gradually accumulates and becomes dirty, or it is rubbed with a guide roller, turn bar, triangular plate, folding machine, etc. due to insufficient surface strength of the offset printing ink film.

  In general, when using low-quality, low-quality printing paper, paper peeling tends to occur when the paper surface strength is low and the offset printing ink has a high tack, and when the printing speed is high, the offset printing ink is used for printing. It becomes more likely to occur when the apparent tack of becomes higher.

  Blanking is a phenomenon in which ink with increased tackiness is gradually deposited on a blanket. However, if the solubility of offset printing ink is high, the increase in tack over time (tack increase width ΔT) increases. It is also said that the stability is poor. Paper peeling is likely to occur due to this phenomenon.

  Patent Document 1 uses a polymer obtained by polymerizing at least one of an olefin monomer and a diene monomer using a rosin-modified phenol resin and a vegetable ester as main components of the solvent, which is significantly higher than conventional inks. Although a printing ink composition with reduced VOC and high-speed setting properties has been disclosed, it relates to sheet-fed ink, and heat set offset rotary ink has poor drying properties and cannot be used practically.

  Patent Documents 2 to 4 disclose printing ink compositions that use a rosin-modified phenolic resin having a fatty acid ester and / or an aliphatic ether and an n-heptane tolerance of 10 ml to 25 ml, and no petroleum solvent. However, rosin-modified phenolic resins in the above range are usually used selectively. By combining specific fatty acid esters and / or aliphatic ethers, drying properties equivalent to conventional inks and printability and printing are available. It has an effect. However, examples using less than 10 ml of rosin-modified phenolic resin are not described in detail in the comparative examples, and their critical significance is unknown. In addition, aliphatic ether has a peculiar unpleasant odor, which not only deteriorates the working environment, but also has a problem that a strange odor is felt in a printed material printed using the ink.

  Patent Document 5 discloses an offset rotary printing ink containing a resin for varnish and a specific fatty acid ester and having an excellent balance between evaporation drying property and on-machine stability without impairing printability. However, there was no description about the solubility of the rosin-modified phenolic resin used in the resin for varnish, and it was not satisfactory in terms of printability such as gloss and paper peeling other than evaporative drying and on-machine stability.

JP 2002-155227 A JP 2004-204202 A JP 2004-204203 A JP 2004-244519 A JP 2006-176754 A

  Therefore, the present invention satisfies the basic performance as a printing ink, is excellent in setability and drying property, has low tack, and is environmentally friendly printing ink composition that is difficult to blanking and the printing. It aims at providing the printed matter produced using the ink composition.

  As a result of intensive studies, the present inventor has found that the problem can be solved by using a fatty acid ester of vegetable oil and a specific rosin-modified phenol resin having a heptane tolerance of 9 ml or less, and completed the present invention.

That is, the present invention
[1] A printing comprising a fatty acid ester of vegetable oil and a rosin-modified phenolic resin having a heptane tolerance of 9 ml or less, and the fatty acid ester of vegetable oil is 20 to 50% by weight in the printing ink composition Ink compositions,
[2] A printed matter obtained by printing the printing ink composition according to [1] on paper as a base material,
It is.

  According to the present invention, after satisfying the basic performance as a printing ink, the environment-friendly printing ink composition which is excellent in setability and drying property, has a low tack and is difficult to blanking, and the printing ink. Prints made using the composition can be provided.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that this embodiment is merely an embodiment for carrying out the present invention, and the present invention is not limited by this embodiment, and various modified embodiments can be made without departing from the gist of the present invention. Is possible.

  The printing ink composition of the present invention (hereinafter also simply referred to as ink) contains a fatty acid ester of vegetable oil and a rosin-modified phenolic resin having a heptane tolerance of 9 ml or less, and the fatty acid ester of vegetable oil is contained in the printing ink composition. The printing ink composition is characterized by being 20 to 50% by weight.

  The fatty acid ester of the vegetable oil of the present invention is derived from soybean oil, linseed oil, rapeseed oil, olive oil, tung oil, cottonseed oil, safflower oil, sunflower oil, tall oil, dehydrated castor oil, sesame oil, mustard oil, corn oil, peanut oil, etc. Examples thereof include those obtained by transesterifying a fatty acid having 18 or more carbon atoms and a monoalcohol, or a fatty acid monoalkyl ester obtained by directly esterifying a fatty acid of a vegetable oil and a monoalcohol. In addition, the alcohol-derived alkyl group constituting the fatty acid monoalkyl ester preferably has 1 to 12 carbon atoms, and specific examples include methyl, ethyl, propyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl. Undecyl, dodecyl, 3-methyl-1-butyl, 2,2-bis (hydroxymethyl) butyl, 2,4-dimethyl-3-pentyl, 2-ethyl-1-butyl, 2-ethyl-1-hexyl, 3,5,5-trimethyl-1-hexyl, 4-decyl, 2-isopropyl-5-methyl-1-hexyl, 2-butyl-1-octyl and the like. Of these, methyl, ethyl, propyl, butyl, isobutyl, octyl, 2-ethylhexyl, 2,2-bis (hydroxymethyl) butyl and the like are particularly preferable. For example, tall oil fatty acid butyl ester, tall oil fatty acid isobutyl ester, soybean oil fatty acid methyl ester, soybean oil fatty acid ethyl ester, soybean oil fatty acid propyl ester, soybean oil fatty acid butyl ester, soybean oil fatty acid hexyl ester, soybean oil fatty acid 2 -Ethylhexyl ester, linseed oil fatty acid methyl ester, linseed oil fatty acid ethyl ester, linseed oil fatty acid propyl ester, linseed oil fatty acid butyl ester, linseed oil fatty acid 2-ethylhexyl ester, castor oil fatty acid methyl ester and the like are preferable. The fatty acid ester of the vegetable oil increases the solubility in the resin and has an excellent effect on improving the gloss of the printed matter.

  The fatty acid monoalkyl ester has an acid value of preferably 4 mgKOH / g or less, more preferably 1 mgKOH / g or less. When the amount exceeds 4 mgKOH / g, the polarity increases, so that the ink tends to adhere to the non-image area of the plate, causing stains. The acid value is determined by the number of mg of potassium hydroxide required to neutralize the free acid contained in 1 g of the sample (according to JIS K3331).

  The content of the fatty acid ester of the vegetable oil is preferably in the range of 20 to 50% by weight in the printing ink composition. Among these, particularly preferable is the range of 25 to 40% by weight. If it is less than 20% by weight, the dissolving power of the ink will be insufficient, and there is a risk of deterioration of the inking property and glossiness. If it exceeds 50% by weight, the dissolving power is too high, and the inking property and glossiness will be improved. However, the drying property is reduced and misting becomes easy.

  The heptane tolerance of the rosin-modified phenolic resin of the present invention (when a plurality of rosin-modified phenolic resins are used in combination) is preferably 9 ml or less. Particularly preferred is a range of 5 ml or more and 9 ml or less. A rosin-modified phenolic resin with a heptane tolerance of less than 5 ml is extremely low in solubility and difficult to obtain in production, and also has poor fluidity, inter-roller transferability, and poor on-paper surface quality. Stable prints cannot be produced. If it is larger than 9 ml, the setting property and drying property are inferior, the fluidity becomes excessive, the halftone dot becomes thick, and misting becomes easy.

  It is important to use a fatty acid ester of vegetable oil in combination with a rosin-modified phenolic resin having a heptane tolerance of 9 ml or less. This enables quick release of the fatty acid ester of vegetable oil and rosin-modified phenolic resin in the ink during printing. As a result, setability and dryness are greatly improved. On the other hand, when a fatty acid ester of vegetable oil is not used and a conventional AF solvent or the like is used, the solubility in the resin is inferior, and the varnish becomes cloudy or has no effect on improving gloss. Further, when a rosin-modified phenol resin having a heptane tolerance of 9 ml or less is not used, the fluidity becomes excessive.

  In addition, a fatty acid ester of the vegetable oil of the present invention, a rosin-modified phenol resin having a heptane tolerance of 9 ml or less, a solvent, an aluminum chelating agent, and the like are mixed and heated to dissolve to obtain a varnish for printing ink (hereinafter also simply referred to as varnish). It is preferable.

  In the present invention, the resin heptane tolerance means that 1 g of rosin-modified phenolic resin is weighed in a beaker, dissolved in 9 g of toluene, and normal heptane is dropped with a burette at 25 ° C. The amount of normal heptane dripping (ml) until no newspaper type (10 points) can be determined.

The rosin-modified phenolic resin of the present invention preferably has a weight average molecular weight in the range of 40,000 to 300,000. Among them, particularly preferred is a weight average molecular weight in the range of 50,000 to 250,000. When the weight average molecular weight exceeds 300,000, the solubility decreases, and the solvent releasability becomes faster, so that the on-machine stability is inferior and paper peeling tends to occur. Moreover, since it has high elasticity, it tends to cause a decrease in pigment dispersibility, a decrease in thickness on the paper surface, and a decrease in gloss due to a decrease in leveling and fluidity.
Here, the weight average molecular weight is a value measured by the GPC method (polystyrene conversion).

  The content of the rosin-modified phenolic resin of the present invention is preferably in the range of 20 to 35% by weight in the total amount of printing ink. Among these, particularly preferable is the range of 25 to 30% by weight in the total amount of the printing ink. If it is less than 20% by weight, since the solid content is small, the viscosity becomes low, the fluidity becomes excessive and it becomes difficult to obtain a desired ink, and if it exceeds 35% by weight, the gloss tends to be lowered.

  The ratio of the fatty acid ester of the vegetable oil of the present invention to the rosin-modified phenolic resin is preferably in the range of 40/60 to 70/30 by weight ratio in the varnish. Of these, particularly preferred is the range of 45/55 to 60/40. When the ratio of the fatty acid ester of vegetable oil to the rosin-modified phenol resin exceeds 60% by weight, the solubility is inferior, the setability is inferior, the tack is increased, and the paper is easily peeled off.

  Examples of the binder resin other than the rosin-modified phenol resin of the present invention include other rosin-modified phenol resins, polymerized rosin esters, rosin-modified maleic acid resins, alkyd resins, polyester resins, and petroleum resins. A combination of the above can be used.

  As a solvent used in the present invention, for the purpose of imparting fluidity, an AF solvent, a normal paraffin solvent, an isoparaffin solvent, a petroleum solvent typified by a machine oil, a cylinder oil, a vegetable oil, a fatty acid ester of a vegetable oil, Vinylidene olefins can be selected and used as appropriate, but when using environmentally friendly inks that do not contain VOC components, the use of petroleum solvents such as AF solvents and machine oils should be avoided, and fatty acids in vegetable oils and vegetable oils. Use of a non-volatile solvent such as ester and vinylidene olefin is preferred.

  As the vegetable oil used in the present invention, soybean oil is mainly used. Examples of other vegetable oils include linseed oil, rapeseed oil, coconut oil, olive oil, tung oil, tall oil, and the like and those obtained by regenerating them.

  The vegetable oil is preferably in the range of 7 to 30% by weight based on the total amount of the printing ink composition of the present invention. Of these, the range of 10 to 25% by weight is particularly preferable. If it is less than 7% by weight, the gloss is lowered. Even if an amount exceeding 30% by weight is added, the effect of improving the gloss is not obtained, the solubility becomes high, and the increase of the tack with time increases, so the adhesiveness of the ink deposited on the blanket increases, and the after-sales The tack remains, making it easier to remove the paper.

  The chelating agent used in the present invention functions as a gelling agent, but metal chelates, particularly aluminum chelate compounds such as ethyl acetoacetate aluminum diisopropoxide and aluminum trisethyl acetoacetate are preferably used.

  The pigment used in the present invention is an organic pigment or an inorganic pigment, such as an organic pigment typified by disazo yellow, carmine 6B, phthalocyanine blue, etc., and an inorganic pigment typified by carbon black, calcium carbonate, etc. There is no particular limitation.

  In the present invention, other additives such as a pigment dispersant, an emulsifier, a drying inhibitor, a drying accelerator, a surface conditioner, and a lubricant can be appropriately used for the purpose of improving the function as a printing ink.

  For example, as anti-friction, anti-blocking agent and slip agent, natural wax such as carnauba wax, paraffin wax, microcrystalline wax, Fischer Trops wax, polyethylene wax, polypropylene wax, polytetrafluoroethylene wax, polyamide wax, silicone Synthetic waxes such as compounds can be exemplified.

  The printing ink composition of the present invention can be produced by a conventionally known method. For example, rosin-modified phenolic resin, fatty acid ester of vegetable oil, solvent, aluminum chelating agent and other additives are mixed and heated to dissolve to obtain a varnish, and a mixture of pigments dispersed in this varnish with three rolls, a bead mill, etc. It is manufactured by adding a solvent, an additive, a fatty acid ester of vegetable oil, and the like.

  The printed matter of the present invention can be produced by ordinary offset printing on paper as a base material.

  As the base material used in the printed matter of the present invention, any paper that can be used for normal offset printing can be used, and in particular, an additional paper suitable for offset printing (non-coated paper), fine coated paper, coated paper, art paper Paper or the like is preferably used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples. In the examples, “part” indicates “part by weight” and “%” indicates “% by weight”.

[Preparation of varnish]
Production Example 1
Rosin-modified phenolic resin R1 (weight average molecular weight 57,000, heptane tolerance 7.9 ml, manufactured by Harima Chemical Co., Ltd.) 37.5 parts, tall oil fatty acid butyl ester (Hartol BU, manufactured by Harima Chemical Co., Ltd.) 31 parts, 31 parts of soybean white oil, 0.4 parts of aluminum chelating agent (ALCH, manufactured by Kawaken Fine Chemical Co., Ltd.) and 0.1 part of dibutylhydroxytoluene are charged into a reaction vessel, and the temperature is raised to 185 ° C. while blowing nitrogen gas. The mixture was stirred and mixed for 60 minutes to obtain varnish V1.

Production Example 2
Rosin-modified phenolic resin R2 (weight average molecular weight 220,000, heptane tolerance 8.0 ml, manufactured by Harima Chemical Co., Ltd.) 35.7 parts, tall oil fatty acid butyl ester (Hartol BU, manufactured by Harima Chemical Co., Ltd.) 32 parts, Charge 32 parts of soybean white oil, 0.2 part of aluminum chelating agent (ALCH, manufactured by Kawaken Fine Chemical Co., Ltd.) and 0.1 part of dibutylhydroxytoluene into the reaction vessel, and raise the temperature to 185 ° C. while blowing nitrogen gas. The mixture was stirred and mixed for 60 minutes to obtain varnish V2.

Production Example 3
Rosin-modified phenolic resin R3 (weight average molecular weight 63,000, heptane tolerance 8.1 ml, manufactured by Harima Chemical Co., Ltd.) 37.1 parts, tall oil fatty acid butyl ester (Hartol BU, manufactured by Harima Chemical Co., Ltd.) 31.2 Part, soybean white oil 31.2 parts, aluminum chelating agent (ALCH, manufactured by Kawaken Fine Chemicals Co., Ltd.) 0.4 part and dibutylhydroxytoluene 0.1 part were charged into a reaction vessel, and nitrogen gas was blown into the tank 185 The temperature was raised to 0 ° C., and the mixture was stirred and mixed for 60 minutes to obtain varnish V3.

Production Example 4
Rosin-modified phenolic resin R6 (weight average molecular weight 90,000, heptane tolerance 11.8 ml, Arakawa Chemical Industries, Ltd.) 41.4 parts, soybean oil fatty acid butyl ester (SFB-2, Toshin Yushi Co., Ltd.) 33 parts, 25 parts of soybean white squeezed oil, 0.5 part of an aluminum chelating agent (ALCH, manufactured by Kawaken Fine Chemical Co., Ltd.) and 0.1 part of dibutylhydroxytoluene were charged in a reaction vessel, and the temperature was increased to 185 ° C. while blowing nitrogen gas. The temperature was raised, and the mixture was stirred and mixed for 60 minutes to obtain varnish V4.

Production Example 5
Rosin modified phenolic resin R4 (weight average molecular weight 148,000, heptane tolerance 50 ml, Arakawa Chemical Industries, Ltd.) 25 parts, rosin modified phenolic resin R5 (weight average molecular weight 122,000, heptane tolerance 30 ml, Arakawa Chemical Industries, Ltd. )) 15 parts, soy white squeezed oil 10 parts, AF solvent 7 (manufactured by Nippon Oil Corporation) 49.25 parts, aluminum chelating agent (ALCH, Kawaken Fine Chemicals Co., Ltd.) 0.65 parts and dibutylhydroxytoluene 0 .1 part was charged into a reaction vessel, heated to 185 ° C. while blowing nitrogen gas, and stirred and mixed for 60 minutes to obtain varnish V5.

Examples 1-3
As shown in Table 1, varnish, cyanine blue (GBK19SD, manufactured by DIC Corporation), calcium carbonate (manufactured by Hakuho Hana, manufactured by Shiraishi Calcium Co., Ltd.), soybean oil fatty acid butyl ester (SFB-2, Toshin Oil and Fat ( Co., Ltd.) is added and mixed, and is further kneaded with a three-roll mill to obtain an ink base. Further, varnish, wax (Shamrock, Floros Purse 153DM) and soybean oil fatty acid butyl ester (SFB-) 2, Toshin Yushi Co., Ltd.) was added and mixed, and the printing ink compositions of Examples 1 to 3 having a viscosity value of 17 to 22 Pa · s measured by an L-type viscometer (25 ° C.) were obtained.

Comparative Example 1
In an example in which a fatty acid ester of vegetable oil and rosin-modified phenol resin exceeding 9 ml were used in combination, the same operation as in Example 1 was performed to obtain a printing ink composition of Comparative Example 1. The formulation is shown in Table 1.

Comparative Example 2
In the example of the conventional product in which the fatty acid ester of the vegetable oil is replaced with AF solvent 7 and soybean white squeezed oil and combined with rosin-modified phenol resin exceeding 9 ml, the same operation as in Example 1 is performed, and the printing of Comparative Example 2 is performed. An ink composition was obtained. The formulation is shown in Table 1.

  The following table test was done about the printing ink composition of Table 1 (Examples 1-3 and Comparative Examples 1-2). The results are shown in Table 2.

[Setability]
Each of the printing ink compositions of Examples 1 to 3 and Comparative Examples 1 and 2 was developed on coated paper with an RI tester (manufactured by Akira Seisakusho), and immediately an automatic ink set tester (Toyo Seiki Seisakusho). The degree of adhesion of the printing ink composition to the high-quality paper superimposed on the color development surface was confirmed by visual observation, and the time required until no adhesion was observed was measured. The shorter this time, the better the setability.

[Drying]
Each of the printing ink compositions of Examples 1 to 3 and Comparative Examples 1 and 2 was subjected to a printing pressure tester (MZ-II, manufactured by Prüfbau Co., Ltd.) under the conditions of a printing pressure of 400 N and a printing speed of 10 m / sec. Then, 0.2 cc of the printing ink composition was developed on coated paper, and the sample surface was dried by adjusting the paper surface drying temperature to 110 to 120 ° C. The dried sample piece was immediately taken out and the stickiness of the sample piece was evaluated by finger touch. The dryness is better as there is no stickiness.
The degree of stickiness was evaluated in three stages: ○: no stickiness, Δ: some stickiness (no problem for practical use), and x: stickiness, not practical.
The Prüfbau printing aptitude tester is a tester developed at the FOGRA printing plate making laboratory in Germany and is widely used for evaluating printing ink compositions.

[tack]
Each of the printing ink compositions of Examples 1 to 3 and Comparative Examples 1 to 2 was used with an incometer (manufactured by Toyo Seiki Seisakusho Co., Ltd.), ink amount 1.31 cc, room temperature 25 ° C., roller temperature 30 ° C., rotation speed. The value (tack value) after 1 minute was measured under the condition of 400 rpm. The lower the tack value, the more difficult it is to peel off and the better.

[Onboard stability]
Each of the printing ink compositions of Examples 1 to 3 and Comparative Examples 1 to 2 was used with an incometer (manufactured by Toyo Seiki Seisakusho Co., Ltd.). The difference (tack change) between the tack value at 0 minutes and the tack value after 10 minutes was measured and evaluated under the condition of 1200 rpm. The smaller the tack change, the better the on-machine stability.
Regarding tack change, ○: Less than 4.0 (best on-machine stability), Δ: 4.0 or more and less than 7.0 (good on-machine stability, no problem in practical use), ×: 7.0 or more (on-machine The stability was inferior and was not practical).

  In addition to the above, the following tests were conducted for other printability.

[Liquidity]
The printing ink compositions of Examples 1 to 3 and Comparative Examples 1 to 2 were measured and evaluated for the spread of ink (diameter: mm) for 1 minute with a spread meter (manufactured by Toyo Seiki Seisakusho). With respect to the spread diameter, ◯: 39.0 mm or more and less than 41.0 mm (optimally practical), Δ: 38.0 mm or more and less than 39.0 mm, or 41.0 mm or more and less than 42.0 mm (no problem for practical use), ×: 38. The evaluation was made in three stages: less than 0 mm or 42.0 mm or more (not practical due to insufficient fluidity or excessive fluidity).

[Glossy]
Each printing ink composition of Examples 1 to 3 and Comparative Examples 1 to 2 was developed on coated paper with an RI tester (manufactured by Akira Seisakusho), and gloss meter PG-1 (Nippon Denshoku Industries Co., Ltd.). The measurement value by a company make, 60 degrees) was evaluated. The higher the gloss value, the better.
The gloss value was evaluated in three stages: ○: 55.0 or more, Δ: 48.0 or more, less than 55.0 (no problem for practical use), and X: less than 48.0 (low gloss, not practical). .

[Missing]
Each printing ink composition of Examples 1 to 3 and Comparative Examples 1 to 2 was used with an incometer (manufactured by Toyo Seiki Seisakusho Co., Ltd.). The scattering state of the ink scattered on the white paper installed on the back surface of the incometer roll after operating for 1 minute under the condition of 2000 rpm was visually evaluated. The smaller the amount of scattering, the better the misting. The scattering state was evaluated in three stages: ○: few, Δ: slightly more (no problem for practical use), x: many (not practical).

[Abrasion resistance]
Each of the printing ink compositions of Examples 1 to 3 and Comparative Examples 1 and 2 was developed on a coated paper with an RI tester (manufactured by Akira Seisakusho), and immediately using an oven capable of adjusting the temperature, The sample piece was heated for 10 seconds and dried. After heating, the sample piece was allowed to cool for 1 minute, and the ink surface of the cooled sample piece was rubbed with a white paper using a Gakushin type frictional resistance tester, and the degree of color fading was visually evaluated. The smaller the color fading, the better the friction resistance. The degree of color fading was evaluated in three stages: ○: few, Δ: slightly more (no problem for practical use), x: many (not practical).

[Emulsification test]
For each of the printing ink compositions of Examples 1 to 3 and Comparative Examples 1 to 2, a lithotronic emulsification tester (manufactured by NOVOCONTROL) was used, and 25 ml of ink was rotated at 1200 rpm at 40 ° C. and 2 ml for 25 g of ink. Water was added at a rate of / min and the amount of water at the time when the ink was saturated was measured and evaluated as the weight percent with respect to 25 g of ink.
Emulsification rate (%) = 100 × (moisture content g at saturation) / (ink content g)
It has been confirmed that the emulsification rate is preferably in the range of approximately 30 to 50% in a printing test using a printing press.

  According to Table 2, compared with the printing ink compositions of Examples 1 to 3, the printing ink composition using a resin having a heptane tolerance greater than 9 ml similar to Patent Document 3 of Comparative Example 1 is set and dried. As a result, the properties and abrasion resistance were inferior, fluidity was excessive, and misting was inferior. In addition, the printing ink composition which is an example of the conventional product of Comparative Example 2 has the same or inferior level in terms of drying property, fluidity, gloss, misting, friction resistance and suitability for emulsification. In addition, the on-machine stability was poor and the tack was high.

[Actual machine printing test: rubbing dirt]
The printing ink compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were subjected to a printing test using a four-color offset rotary press, and the paper surface temperature at which no rubbing stain was generated was examined. Note that the paper surface temperature at which rubbing stain does not occur means that, at a certain paper surface temperature, an appropriate number of copies of the printed matter immediately after printing discharged from the printing press folder are extracted, and the solid image portion is immediately rubbed with a finger, and the rubbing condition is visually observed. When the rubbing stain did not occur, the set temperature of the dryer was lowered, the same operation was repeated until the rubbing stain was generated, and the lowest paper surface temperature when the rubbing stain did not occur was determined.
Printing machine: 4-color offset rotary press manufactured by Komori Corporation Printing speed: 600 rpm
Printing plate: CTP plate Paper: Fine coated paper The paper surface temperature was measured using a radiation thermometer IT-540 (manufactured by Horiba, Ltd.) and the temperature on the paper surface immediately after passing through the dryer outlet. At the same time, the preset temperature of the dryer was recorded.

[Actual machine printing test: Inking]
About each printing ink composition of Examples 1-3 and Comparative Examples 1-2, the feed amount of the ink which can give the printed matter of a standard density | concentration is measured, The increase / decrease is based on the conventional product of the comparative example 2. In%.

[Actual machine printing test: dot gain]
The printed matter obtained in the above-mentioned inking property test was observed with a 100-fold magnification microscope for thick halftone dots. Based on the conventional product of Comparative Example 2, ○: thinner than the reference, x: thicker than the reference 2 Rated by stage.

  According to Table 3, it was found that the printing ink compositions of Examples 1 to 3 had the same drying temperatures as those of Comparative Examples 1 and 2, but clearly had excellent inking properties and dot gain. From these results, by using a specific resin and fatty acid ester of vegetable oil in combination, at the same drying temperature as the conventional product, the inking property is improved and the ink feed amount is suppressed. Reduces ink piling (blank piling), contributes to improving production efficiency by reducing the number of blanket washings and reducing unnecessary machine stoppages, and can produce clear prints by avoiding the occurrence of thick dots. This contributes to the improvement of quality.

Claims (2)

Containing a fatty acid ester of vegetable oil and a rosin-modified phenolic resin having a heptane tolerance of 9 ml or less,
Further fatty acid esters of vegetable oils, heat-set type offset rotary printing ink composition characterized in that 20 to 50% by weight heat-set type offset rotary printing ink composition. The printed matter obtained by printing the heat-set type offset rotary printing ink composition of Claim 1 on the paper which is a base material.