JP2002003770A - Gel varnish for offset printing ink, and offset printing ink composition using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a gel varnish for offset printing ink to be used for obtaining an offset printing ink composition excellent in settability and resistance to primary and secondary blocking in making an offset printing and impairing no performances required for offset printing such as print gloss, print dryability and print stability with time. SOLUTION: This gel varnish for offset printing ink is characterized by being obtained by heating a mixture comprising 20-60 wt.% of rosin-modified phenolic resin and/or rosin-modified maleic acid resin, a vegetable oil component and, as necessary, mineral oil as the solvent component, a gelatinizer and 0.5-15 wt.% of an olefin-based or diene-based polymer <19 (MPa)1/2 in solubility parameter and compatible with the solvent component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gel varnish for offset printing ink and an offset printing ink composition using the same. Gel varnish for offset printing inks, and an offset printing ink using the same, which enables the production of offset printed materials having excellent blocking resistance such as blocking when processing printed materials (hereinafter referred to as secondary blocking). Composition.

[0002]

2. Description of the Related Art In general, offset printing inks are composed of a colorant, a binder resin, a petroleum-based solvent such as mineral oil, etc., and various additives are used as necessary to improve various printing properties. Have been.

[0003] In recent years, awareness of environmental issues has been increasing, and environmental measures are also required in the printing ink industry. As a countermeasure against the environmental problem, a policy is adopted to replace harmful raw materials with harmless or minimally harmful raw materials among raw materials currently in use. For example, in the field of offset printing, non-VOC or low-VOC (VOC = Volatile Organic Compo) obtained by replacing some or all of mineral oils with vegetable oil components such as soybean oil.
und) offset printing inks are attracting attention.

[0004] However, there is a fundamental difference in performance between the mineral oil and the vegetable oil component that affects the ink performance, such as the drying property and the solubility of the resin. For example, when a vegetable oil component is frequently used in offset printing ink, problems such as a decrease in setting property and primary blocking and secondary blocking occur. This is because the solvent release from the ink printed on the paper is slow and the vegetable oil component remains in a large amount, and the vegetable oil component has a higher viscosity than mineral oils and a high property of dissolving the resin.

That is, in offset printing, excellent setability is an indispensable performance, whereas the ink containing an increased amount of the vegetable oil component requires a considerable amount of time to set, and the ink printed on printing paper. At present, since a large amount of vegetable oil components remain therein, it is very difficult at present to clear the technical problems required for offset printing.

[0006]

SUMMARY OF THE INVENTION The present inventors have previously described
By using a gel varnish for an offset printing ink obtained by gelling a rosin-modified phenol resin with a very large amount of a gelling agent as expected from the prior art, the drying and setting properties of the offset printing ink composition can be improved. And filed an application as Japanese Patent Application No. 11-92941.

However, as a result of further study on the contents of the above-mentioned application, this method shows that the viscosity change stability of the offset printing ink composition over time (stability over time).
In some cases, a longer period of storage than usual is required, and it is considered that fine adjustment of the addition amount is necessary.

[0008] Therefore, the present invention has the above-mentioned problems of the prior art,
In addition, in view of the newly discovered problems, offset printing ink compositions capable of satisfying the required performance required for offset printing such as setability, primary and secondary blocking resistance, aging stability, and drying property. The task is to provide

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems. As a result, a varnish comprising a binder resin and a vegetable oil component as a solvent component has a solubility parameter of 19 (MPa). By using a gel varnish for offset printing ink gelled with a gelling agent in the presence of an olefin-based or diene-based polymer that is smaller than ^1/2 and compatible with the solvent component,
We found a new fact that the set performance, primary resistance, and secondary blocking resistance were excellent, and did not hinder the required performance required for offset printing such as stability over time and drying properties, and completed the present invention. .

That is, the invention according to claim 1 is a logistics apparatus.
Modified phenolic resin and / or rosin modified male
Acid resin 20-60% by weight, vegetable oil component as solvent component
And optionally mineral oils, gelling agents, and solubilities
Parameter is 19 (MPa) ^1/2Smaller and solvent
Olefin or diene polymers compatible with the components
A mixture consisting of 0.5 to 15% by weight is heated.
Gel varnish for offset printing ink
I do.

[0011] The invention according to claim 2 is based on claim 1.
Wherein the olefin-based or diene-based polymer having a solubility parameter of less than 19 (MPa) ^1/2 and being compatible with a solvent component is liquid at room temperature.

The invention according to claim 3 is based on claim 1.
Or a gel varnish for offset printing ink, wherein a part or all of the vegetable oil component according to 2 is a fatty acid ester compound derived from vegetable oil.

Further, the invention according to a fourth aspect relates to an offset printing ink composition comprising the gel varnish for an offset printing ink according to any one of the first to third aspects in an amount of 20 to 80% by weight.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the gel varnish for offset printing ink and the offset printing ink composition using the same according to the present invention will be described in more detail.

As the binder resin used to obtain the gel varnish for offset printing ink of the present invention, a rosin-modified phenol resin and / or a rosin-modified maleic resin are used. If necessary, synthetic resins such as various alkyd resins, petroleum resins, and modified resins thereof can be used in combination.

First, the rosin-modified phenol resin preferably has a weight average molecular weight of 10,000 to 25.
000. Weight average molecular weight of 250,0
If it exceeds 00, there is a problem that a trouble at the time of manufacturing is likely to occur. If the rosin-modified phenolic resin has too high an acid value and a hydroxyl value, the resulting printing ink tends to have a reduced water resistance, which tends to cause problems such as stains in offset printing, and an acid value and a hydroxyl value. Is too low, the unreacted gelling agent remains, and the stability of the resulting offset printing ink composition over time tends to deteriorate. Therefore, a rosin-modified resin having appropriate acid value and hydroxyl value is used. It is preferable to select a phenol resin and adjust the amount of the gelling agent used.

The rosin-modified phenolic resin usable in the present invention includes, for example, rosins or derivatives thereof,
Phenolaldehyde addition condensate (so-called resol)
And, if necessary, those obtained by a reaction with a polyhydric alcohol. Here, the rosins or derivatives thereof represent rosins or carboxyl group-containing derivatives thereof. Rosins include gum rosin, wood rosin, tall oil rosin, disproportionated rosin, hydrogenated rosin and polymers thereof, and carboxyl group-containing derivatives thereof include unsaturated acids such as maleic acid, itaconic acid and crotonic acid. A rosin derivative to which a carboxylic acid has been added is exemplified.

The phenols used in the phenol aldehyde addition condensate include phenol and a phenol having 1 to 1 carbon atoms.
20 alkyl-substituted phenols substituted with 20 linear, branched or cyclic alkyl groups, such as p-cresol, m-
Cresol, p-propylphenol, p-tert-
Butylphenol, p-aminophenol, p-cyclohexylphenol, p-tert-octylphenol, p-nonylphenol, p-decylphenol, p
Alkyl-substituted phenols such as -dodecylphenol; aromatic-substituted phenols such as phenylphenol and cumylphenol; and polyhydric phenols such as catechol, resorcinol, hydroquinone, bisphenol A, bisphenol S and bisphenol F. .

As a method for producing the corresponding phenol aldehyde addition condensate using the phenols, a method in which the phenols and the aldehydes are heated and reacted in an aqueous or organic solvent in the presence of an alkali catalyst, that is, resole A method for producing a phenolic resin, or a phenol and an aldehyde are heated and reacted in an aqueous or organic solvent in the presence of an acid catalyst to first produce a novolak phenolic resin, and then in the presence of an aldehyde and an alkali catalyst. And a method for obtaining a resolated phenolic resin by heat reaction.

The aldehydes used include formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, glyoxazole, furfural and the like. Examples of the alkali catalyst include sodium hydroxide, potassium hydroxide, calcium hydroxide and the like. Examples of the acid catalyst include acetic acid, hydrochloric acid, phosphoric acid, hypophosphorous acid, sulfuric acid, p-toluenesulfonic acid, trifluoromethylsulfuric acid, and trifluoromethylacetic acid. The preferred degree of polymerization of the phenolic resin obtained here is such that the number of phenol nuclei is at least two,
More preferably, three or more are preferred from the viewpoint of solubility.

Examples of polyhydric alcohols include glycerin, trimethylolethane, trimethylolpropane, ethoxylated trimethylolpropane, propoxylated trimethylolpropane, neopentyl glycol, pentaerythritol, dipentaerythritol, sorbitol,
Examples include aliphatic polyhydric alcohols such as 1,6-hexanediol, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, and polypropylene glycol.

The rosin-modified phenolic resin which can be used in the present invention comprises the above-mentioned rosin, resole and, if necessary, polyhydric alcohol in any order at an elevated temperature, preferably in a temperature range of 150 to 300 ° C. It can be obtained by causing a heat reaction. If necessary, an acid catalyst can be used in the reaction. Examples of such an acid catalyst include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, methanesulfonic acid, and ethanesulfonic acid. In order to prevent coloring, a reducing agent such as hypophosphorous acid, triphenyl phosphite, triphenyl phosphate or the like can be used in combination. As a catalyst other than the acid catalyst, magnesium salts such as magnesium hydroxide, magnesium carbonate, magnesium bicarbonate, magnesium acetate, magnesium formate, and magnesium oxalate can also be used. Furthermore, in order to promote the condensation reaction, the reaction can be performed under reduced pressure.

Further, rust of the metal can be prevented by neutralizing hydrogen ions derived from the remaining acid catalyst and the like. As the neutralizing agent, hydroxides, oxides, or carboxylate salts of metals such as lithium, cesium, magnesium, calcium, strontium, barium, aluminum, zinc, titanium, zirconium, antimony, and selenium can be used.

The rosin-modified maleic resin preferably has a weight average molecular weight of 5,000 to 250,
000. Weight average molecular weight of 250,000
Exceeding the range causes problems such as easy production troubles. If the acid value and the hydroxyl value of the rosin-modified maleic acid resin are too high, the water resistance of the obtained printing ink is reduced and offset printing tends to cause troubles such as stains. If the value of the valence is too low, the unreacted gelling agent remains, and the aging stability of the obtained offset printing ink composition tends to deteriorate, so that rosin having appropriate acid value and hydroxyl value is used. It is preferable to select a modified maleic acid resin and adjust the amount of the gelling agent used.

In the present invention, in order to obtain an offset printing ink composition having improved setability and primary and secondary blocking resistance, the gel varnish for offset printing ink has a solubility parameter of 1 (Solubility Parameter).
An olefin-based or diene-based polymer which is smaller than 9 (MPa) ^1/2 and compatible with the solvent component is contained. More preferably, the solubility parameter is 15-18 (MP
a) It contains an olefin-based polymer that is ^1/2 , is liquid at ordinary temperature, and is compatible with the solvent component. Specific examples of the olefin-based or diene-based polymer include polybutadiene, polyisoprene, polyisobutylene, and a copolymer thereof. Olefin or diene polymers that are incompatible with the solvent component have insufficient miscibility with other components. On the other hand, if the solubility parameter of the olefin-based or diene-based polymer is higher than the above range, the compatibility with other components becomes too high, and the setting property and the blocking resistance cannot be improved. The use of an olefin-based or diene-based polymer having a solubility parameter of less than 19 (MPa) ^1/2 and compatible with a solvent component (vegetable oil component and, if necessary, mineral oils) makes it possible to improve the setting property and the like. The improvement in blocking resistance is due to the fact that the solubility parameter of the olefin-based or diene-based polymer, which is far away from the binder resin component, is compatible with the solvent component, thereby improving the releasability from the resin component as a whole solvent system. It is thought that it depends. The solubility parameter of the olefin-based or diene-based polymer can be determined by a dissolution method, a swelling method, or the like. The main one is a polymer handbook (J. Brandru).
p and EH Immergut, Polymer Handbook 3rd ed., Jo
hn Wiley & Sons, Inc., New York, 1989, Section VI
I) etc. can be referred to.

In the present invention, the timing of addition of the olefin or diene polymer is important, and it is necessary to add it at the time of producing a gel varnish for offset printing ink.
If the olefin-based or diene-based polymer is added at times other than during the production of the gel varnish for offset printing inks, sufficient performance cannot be obtained in terms of the stability over time of the resulting ink composition. Also, when an olefin or diene polymer is added during the production of a gel varnish for offset printing inks,
The setting time is shorter than when the olefin-based or diene-based polymer is added at times other than during the production of the gel varnish for offset printing ink.

The amount of the olefin-based or diene-based polymer to be used is 0.5 to 0.5 in the gel varnish for offset printing ink.
It is in the range of 15% by weight. If the amount of the olefin-based or diene-based polymer is less than the above range, the setting property, the primary resistance, the sufficient effect of improving the secondary blocking cannot be obtained,
If it exceeds the above range, there are problems such as insufficient performance such as gloss and stability over time. However, since the appropriate amount of the olefin or diene polymer depends on the type of the binder resin and the olefin or diene polymer to be used, it is preferable to select an appropriate amount within the above range.

The vegetable oil component that can be used to obtain the gel varnish for offset printing inks of the present invention includes vegetable oils and fatty acid ester compounds derived from vegetable oils.

Examples of the vegetable oil include drying oils such as soybean oil, cottonseed oil, linseed oil, safflower oil, tung oil, tall oil, dehydrated castor oil, and canola oil, or semi-drying oils. These can be used alone or in combination of two or more.

The fatty acid ester compounds derived from vegetable oils include the monoalkyl ester compounds of fatty acids derived from the aforementioned dry oils or semi-dry oils. Fatty acids constituting such fatty acid monoesters have 16 to 16 carbon atoms.
Twenty saturated or unsaturated fatty acids are preferable, and examples thereof include stearic acid, isostearic acid, hydroxystearic acid, oleic acid, linoleic acid, linolenic acid, and eleostearic acid. The alkyl group derived from alcohol constituting the fatty acid monoester preferably has 1 to 10 carbon atoms, and examples thereof include an alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, and 2-ethylhexyl. These fatty acid monoesters can be used alone or in combination of two or more.

In the gel varnish for offset printing inks of the present invention, the vegetable oil and the fatty acid ester may be used alone or in combination as the vegetable oil component. The amount of the fatty acid ester used is preferably 3% by weight or more in the offset printing ink composition.

Mineral oils used as necessary to obtain the gel varnish for offset printing inks of the present invention include those having a boiling point of 160 ° C. or higher, preferably 200 ° C. or higher, which are incompatible with water. . Specifically, n-paraffinic solvents, isoparaffinic solvents, naphthenic solvents, aromatic solvents, petroleum solvents such as α-olefins, light oils, spindle oils generally used as offset printing ink solvents. Examples include oil, machine oil, cylinder oil, turpentine oil, mineral spirit and the like. These can be used alone or in combination of two or more.

In the gel varnish for offset printing inks of the present invention, the vegetable oil component and the mineral oil may be used alone or in combination with the vegetable oil component.

Examples of the gelling agent used for obtaining the gel varnish for offset printing inks of the present invention include aluminum alcoholates, aluminum chelate compounds, and the like. Preferred specific examples thereof include aluminum triisopropoxide and mono-isopropoxide. Examples thereof include sec-butoxyaluminum diisopropoxide, aluminum tri-sec-butoxide, aluminum acetoacetate aluminum diisopropoxide, and aluminum trisethylacetoacetate. The use amount of the gelling agent is preferably 1 to 15% by weight based on the binder resin. If the amount of the gelling agent exceeds the above range, there are problems such as productivity, stability over time, and a problem that a proper tack-viscosity balance as an ink cannot be obtained. However, since an appropriate amount of the gelling agent varies depending on a resin having a crosslinkable functional group to be used, it is preferable to select an appropriate amount within the above range.

In order to obtain the gel varnish for offset printing inks of the present invention using the above-mentioned materials, for example, the following method or the following method is used to make the binder resin 20 to 60% by weight, the olefin or diene polymer 0.5 to 15% by weight, A method of heating a mixture comprising a solvent having a vegetable oil component as a main component and a gelling agent can be employed. However, the scope of the present invention is not limited by these examples.

20 to 60% by weight of a binder resin, 0.5 to 15% by weight of an olefin or diene polymer,
A mixture of a solvent containing a vegetable oil component as a main component and a gelling agent is heated at 150 to 300 ° C. for about 30 minutes to 2 hours to obtain a gel varnish for offset printing ink.

20 to 60% by weight of a binder resin, 0.5 to 15% by weight of an olefin or diene polymer,
A mixture comprising a solvent having a vegetable oil component as a main component is mixed with 150
Heat at about 300 ° C. for about 30 minutes to 2 hours to dissolve the resin as a solid content. Subsequently, a gelling agent is added in an amount of 1 to 15% by weight based on the binder resin.
Then, the gel varnish for offset printing ink is obtained by heating for about 30 minutes to 2 hours.

Next, an offset printing ink composition containing a gel varnish for offset printing ink, which is a use of the gel varnish for offset printing ink of the present invention, will be described in detail.

The offset printing ink composition of the present invention comprises:
By including the specific gel varnish in the offset printing ink composition in an amount of from 20 to 80% by weight, setability, primary and secondary blocking resistance are remarkably improved as compared with conventional offset printing inks, and stability over time is achieved. The properties required for offset printing, such as the properties, drying properties, stains on the printing plate and blanket, and the abrasion resistance, are improved without deterioration.

To produce the offset printing ink composition of the present invention, a conventionally known method can be used. For example, in the gel varnish for offset printing ink of the present invention, a coloring agent,
And optionally, a drying oil and / or a semi-drying oil,
A base for offset printing ink is obtained by adding a vegetable oil-derived fatty acid ester compound, a solvent, a pigment dispersant or a pigment dispersion resin and kneading and dispersing the mixture with a bead mill or a three-roll mill. On the obtained offset printing ink base, a gel varnish for offset printing ink of the present invention,
A method of adding an additive such as a dryer if necessary, adjusting the viscosity to a predetermined value with a drying oil and / or a semi-dry oil, a vegetable oil-derived fatty acid ester compound, a solvent, or the like to obtain an offset printing ink composition. Can be In addition, a known varnish for offset printing ink can be used in the production of the offset printing ink base and the production of the offset printing ink composition as long as the function is not reduced.

As the colorant for obtaining the offset printing ink composition of the present invention, colorless or colored inorganic or organic pigments generally used for offset printing inks can be used. Inorganic pigments such as barium sulfate, calcium carbonate, and magnetic iron oxide, azo pigments, phthalocyanine pigments, isoindoline pigments,
Organic pigments such as anthraquinone pigments and quinacridone pigments, and car black can be used. The content of the colorant in the offset printing ink composition is 3 to 40.
A suitable amount is about weight%.

As the drying oil and / or semi-drying oil that can be used to obtain the offset printing ink composition of the present invention, those similar to those used to obtain the gel varnish for offset printing ink can be used.

As the vegetable oil-derived fatty acid ester compound which can be used to obtain the offset printing ink composition of the present invention, the same compounds as those used for obtaining the above-mentioned gel varnish for offset printing ink can be used.

The solvent other than the vegetable oil component that can be used for obtaining the offset printing ink composition of the present invention has a boiling point of 160 ° C. or higher, preferably 200 ° C. or higher, which is incompatible with water used as the offset printing ink solvent. Mineral oils and the like can be used. Specifically, the same solvents as those used for obtaining the gel varnish for offset printing ink can be exemplified.

Further, the offset printing ink composition of the present invention comprises a pigment dispersant, a dryer, a drying retarder, an antioxidant, a surface-coating aid, a friction resistance improver, a set-off inhibitor, a nonionic interface. Additives such as activators can be used as appropriate.

[0046]

EXAMPLES Hereinafter, the gel varnish for offset printing ink and the offset printing ink composition using the same according to the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto unless it departs from the spirit and scope of application. It is not limited. In the following description, “parts” indicates parts by weight.

[Production of gel varnish for offset printing ink] Example A A four-necked flask equipped with a condenser, a thermometer and a stirrer was charged with a weight average molecular weight of 63,000 and an acid value of 18 mg.
KOH / g rosin-modified phenolic resin A (manufactured by Hitachi Chemical Co., Ltd.), soybean oil, mineral oil (AF, manufactured by Nippon Oil Co., Ltd.)
Solvent No. 6, the same applies hereinafter) and a solubility parameter of 17.2 (MPa) ^1/2 , a number average molecular weight of 3,000, and a liquid polybutadiene A at room temperature in the mixing ratio shown in Table 1 (the mixing amount of each component is , Heated to 200 ° C. and dissolved by heating at the same temperature for 1 hour, and then ethyl acetate aluminum diisopropoxide (AL, manufactured by Kawaken Fine Chemicals Co., Ltd.) as a gelling agent.
CH, the same applies hereinafter) so as to have the compounding ratio shown in Table 1, and the mixture was heated and maintained at 170 ° C. for 60 minutes to obtain a gel varnish for an offset printing ink of Example A.

Example B In a four-necked flask equipped with a condenser, a thermometer, and a stirrer, rosin-modified phenolic resin A, soybean oil, mineral oil, polybutadiene A, and a gelling agent were each listed in Table 1.
, And heated to 200 ° C. and heated and maintained at the same temperature for 1 hour to obtain a gel varnish for offset printing ink of Example B.

Example C In Example A, except that the rosin-modified phenol resin A was changed to a rosin-modified phenol resin B having a weight average molecular weight of 130,000 and an acid value of 15 mgKOH / g (manufactured by Hitachi Chemical Co., Ltd.). In the same manner as in Example A, a gel varnish for offset printing ink of Example C was obtained.

Example D A four-necked flask equipped with a condenser, a thermometer and a stirrer was charged with a weight average molecular weight of 7,000 and an acid value of 11 mgK.
OH / g alkyd resin (manufactured by Dainippon Ink and Chemicals, Inc.), rosin-modified phenolic resin A, soybean oil, mineral oil, and polybutadiene A were charged so as to have the mixing ratios shown in Table 1, and the temperature was raised to 200 ° C. Then, after heating and dissolving at the same temperature for 1 hour, a gelling agent was charged so as to have the compounding ratio shown in Table 1, and heated and maintained at 170 ° C. for 60 minutes to obtain a gel varnish for offset printing ink of Example D.

Example E In Example A, except that the soybean oil was changed to linseed oil.
In the same manner as in Example A, a gel varnish for an offset printing ink of Example E was obtained.

Example F In a four-necked flask equipped with a condenser, a thermometer and a stirrer, a fatty acid ester (soy oil fatty acid methyl ester manufactured by Lawter Inc .; the same applies hereinafter), a rosin-modified phenolic resin A, soybean oil, mineral oil and Polybutadiene A was charged so as to have the mixing ratio shown in Table 1, heated to 200 ° C., and dissolved by heating at the same temperature for 1 hour.
And heated and maintained at 170 ° C. for 60 minutes to obtain a gel varnish for an offset printing ink of Example F.

Example G A four-necked flask equipped with a condenser, thermometer and stirrer had a solubility parameter of 16.9 (MP
a) ^1/2 , number average molecular weight 1,000, polybutadiene B liquid at room temperature, rosin-modified phenolic resin A, soybean oil and mineral oil were charged so as to have the mixing ratios shown in Table 1, respectively, and the temperature was raised to 200 ° C. After heating and dissolving at the same temperature for 1 hour, a gelling agent was charged so as to have a mixing ratio shown in Table 1, and 1
The gel varnish G for offset printing ink of Example G was obtained by heating and holding at 70 ° C. for 60 minutes.

Examples H and I In a four-necked flask equipped with a condenser, a thermometer and a stirrer, rosin-modified phenolic resin A, soybean oil, mineral oil and polybutadiene A were charged in the proportions shown in Table 1, respectively. After heating to 200 ° C. and heating and dissolving at the same temperature for 1 hour, the gelling agents were charged so as to have the compounding ratios shown in Table 1, respectively, and heated and maintained at 170 ° C. for 60 minutes, and offset printing of Examples H and I was performed. A gel varnish for ink was obtained.

Example J A rosin-modified phenolic resin A, soybean oil, mineral oil, and polybutadiene A were charged into a four-necked flask equipped with a condenser, a thermometer, and a stirrer so that the mixing ratio was as shown in Table 1, and 200 ° C. After heating and melting at the same temperature for 1 hour, the gelling agent was charged so as to have the compounding ratio shown in Table 1, and heated and maintained at 170 ° C. for 60 minutes to obtain a gel varnish for offset printing ink of Example J. Was.

Comparative Example A A rosin-modified phenolic resin A, soybean oil, and mineral oil were charged into a four-necked flask equipped with a condenser, a thermometer, and a stirrer so that the mixing ratio was as shown in Table 1.
The temperature was raised to 200 ° C., and the mixture was heated and dissolved at the same temperature for 1 hour.
For 60 minutes to obtain a varnish for an offset printing ink of Comparative Example A.

Comparative Example B A rosin-modified phenolic resin A, soybean oil, mineral oil, and polybutadiene A were charged into a four-necked flask equipped with a condenser, a thermometer, and a stirrer so that the mixing ratio was as shown in Table 1. After heating and melting at the same temperature for 1 hour, the gelling agent was charged so as to have the compounding ratio shown in Table 1, and heated and maintained at 170 ° C. for 60 minutes to obtain a varnish for an offset printing ink of Comparative Example B. Was.

Comparative Example C A four-necked flask equipped with a condenser, a thermometer and a stirrer was charged with rosin-modified phenolic resin A, soybean oil, mineral oil and polybutadiene A so as to have the mixing ratios shown in Table 1, respectively. After heating and melting at the same temperature for 1 hour, the mixture was heated and maintained at 170 ° C. for 60 minutes to obtain a varnish for an offset printing ink of Comparative Example C.

Examples KO In a four-necked flask equipped with a condenser, thermometer and stirrer, rosin-modified phenolic resin A, soybean oil, mineral oil and polybutadiene A, having a solubility parameter of 16.
6 (MPa) ^1/2 , a liquid polyisoprene at room temperature and a solubility parameter of 15.2 (MPa) ^1/2 , a liquid polyisobutylene at room temperature were charged so as to have the compounding ratios shown in Table 4, respectively. After heating and dissolving for 1 hour at the same temperature, a gelling agent was charged so as to have the compounding ratio shown in Table 4, and heated and maintained at 170 ° C. for 60 minutes, and the gel varnish for offset printing inks of Examples KO was used. I got

[Production of Offset Printing Ink Composition] Examples 1 to 10 Gel varnish for offset printing ink of Examples A to J, carbon black (MA-7 manufactured by Mitsubishi Chemical Corporation, the same applies hereinafter)
Were mixed in the mixing ratios shown in Table 2, and the mixture was kneaded sequentially with a bead mill and three rolls to obtain each ink base. Then
A wax compound (a polyethylene wax compound manufactured by Shamrock Co., Ltd .; the same applies hereinafter), a drier, and a mineral oil are added to each ink base at the compounding ratio shown in Table 2 and stirred to obtain offset printing ink compositions of Examples 1 to 10. Was.

Comparative Examples 1, 2 and 3 The varnishes for offset printing inks of Comparative Examples A, B and C and carbon black were mixed in the mixing ratios shown in Table 2, and the mixture was kneaded sequentially with a bead mill and three rolls. Got the base. Next, a wax compound, a drier, and a mineral oil were added to the respective ink bases at the compounding ratios shown in Table 2 and stirred to obtain offset printing ink compositions of Comparative Examples 1, 2, and 3.

Comparative Example 4 The varnish for offset printing ink of Comparative Example A and carbon black were mixed at the compounding ratio shown in Table 2 and were successively kneaded with a bead mill and three rolls to obtain an ink base. Next, polybutadiene A was added to the ink base at the compounding ratio shown in Table 2.
A wax compound, a drier, and a mineral oil were added and stirred to obtain an offset printing ink composition of Comparative Example 4.

Examples 11 to 15 The gel varnishes for offset printing inks of Examples K to O and carbon black were mixed at the mixing ratios shown in Table 5, and were successively kneaded with a bead mill and three rolls to obtain ink bases. . Next, a wax compound, a drier, and a mineral oil were added to each ink base at the compounding ratio shown in Table 5,
After stirring, the offset printing ink compositions of Examples 11 to 15 were obtained.

[Performance Evaluation Test] With respect to the offset printing ink compositions of Examples 1 to 10, Comparative Examples 1 to 4, and Examples 11 to 15, the following evaluations were made with respect to printing performance.

(1) Gloss Each offset printing ink composition was coated on a coated paper with an RI tester (Meiji Seisakusho Co., Ltd.), left at room temperature for one day, and then measured for 60-60 ° reflectance with a gloss meter. (Digital gloss meter manufactured by Murakami Color Research Laboratory Co., Ltd.).

(2) Setability Each offset printing ink composition was coated on coated paper with an RI tester (Meiji Seisakusho), and then used with an automatic ink set tester (Toyo Seiki Seisakusho). The degree of adhesion of the ink to the high-quality paper was observed, and the time (minutes) required for the ink to no longer adhere was measured. The shorter this time, the better the setability.

(3) Suitability for primary blocking resistance Each offset printing ink composition was coated on a coated paper (NK-High Coat 73K, Nippon Koshi) with a sheet-fed offset printing machine.
Co., Ltd.), 10000 sheets are stacked on a bar, and
The degree of blocking when left for a long time was visually evaluated based on the following criteria. The better this evaluation is, the better the primary blocking resistance is. 3: Low blocking 2: Medium blocking 1: High blocking

(4) Suitability for Secondary Blocking Resistance Each offset printing ink composition was coated on a coated paper (NK-High Coat 73K;
Co., Ltd.), left standing at room temperature for 24 hours, and visually checked the degree of blocking when 200 sheets of printed matter were cut and overlapped by a cutting machine based on the following criteria. The better this evaluation is, the better the secondary blocking resistance and the drying property are. 3: Low blocking 2: Medium blocking 1: High blocking

(5) Stability over time Each offset printing ink composition was stored in two closed containers, one at room temperature and the other at 60 ° C. for 24 hours. These viscosities were measured with a Raleigh viscometer and a spread meter, and evaluated based on the following criteria. 3: Small change (no practical problem) 2: Medium change (no practical problem) 1: Large change (a practical problem)

[Evaluation Results] Table 3 shows the results of the above evaluations of the offset printing ink compositions of Examples 1 to 10 and Comparative Examples 1 to 4. For the offset printing ink compositions of Examples 11 to 15, the results of the evaluation are shown in Table 6.

[0071]

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

[0074]

[Table 4]

[0075]

[Table 5]

[0076]

[Table 6]

[0077]

When the varnish for offset printing ink of the present invention is used, the offset printing ink which is excellent in setting property, primary and secondary blocking suitability, and does not impair the gloss, drying property and stability over time of the printed surface. A composition is obtained.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takashi Iwase 1-23-23-37 Edobori, Nishi-ku, Osaka-shi F-term in Sakata Inc. Co., Ltd. 4J039 AB04 AB06 AD01 AD14 AD15 AE02 AE06 AF01 BC07 BC20 BC59 BE01 BE23 CA07 EA10 EA33 EA44 EA48 GA02

Claims (4)

[Claims] 1. A rosin-modified phenolic resin and / or a rosin-modified maleic resin of 20 to 60% by weight, a vegetable oil component as a solvent component and, if necessary, a mineral oil, a gelling agent, and a solubility parameter of 19 (MPa). ^A gel varnish for offset printing inks, characterized by heating a mixture of 0.5 to 15% by weight of an olefin or diene polymer which is smaller than ^1/2 and compatible with a solvent component. 2. The method according to claim 1, wherein the solubility parameter is 1.
A gel varnish for offset printing inks, characterized in that the olefin or diene polymer which is smaller than 9 (MPa) ^1/2 and is compatible with the solvent component is liquid at room temperature. 3. A gel varnish for offset printing inks, wherein part or all of the vegetable oil component according to claim 1 or 2 is a vegetable oil-derived fatty acid ester compound. 4. An offset printing ink composition comprising the gel varnish for offset printing ink according to claim 1 in an amount of 20 to 80% by weight.