JP2014043563A - Rosin-modified phenol resin for offset printing, gel varnish for offset printing, and offset printing ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel rosin-modified phenol resin for an offset printing ink, which, in spite of its high molecular weight, has excellent solubility with an aliphatic hydrocarbon solvent and can improve fluidity of an offset printing ink while maintaining misting resistance, drying property and glossiness of the offset printing ink.SOLUTION: The rosin-modified phenol resin is used as a binder resin for an offset printing ink: the rosin-modified phenol resin is obtained by an esterification reaction of polyol (B) with a reaction product (A) of rosin (a1), a metal compound (a2) and alkylphenol-formaldehyde condensate (a3) in the presence of a sulfonic acid catalyst (C) and has a weight average molecular weight of 20,000 to 150,000. The rosin (a1) is natural rosin selected from the group consisting of gum rosin, tall rosin and wood rosin.

Description

  The present invention is obtained by using a rosin-modified phenol resin used as a binder resin for offset printing, particularly offset printing using dampening water, a gel varnish for offset printing ink obtained using the rosin-modified phenol resin, and the gel varnish. It relates to offset printing ink.

  Conventionally, as an ink binder resin used for offset printing, particularly offset printing using fountain solution, it is excellent in the drying property and gloss of the ink film, so that rosins, phenol-formaldehyde condensates and polyols are reacted. The so-called rosin-modified phenolic resin obtained in this way is used award.

  The rosin-modified phenolic resin may be used as a varnish dissolved in a solvent such as vegetable oil or petroleum solvent, but is also often used as a gel varnish reacted with a gelling agent such as an aluminum compound. A target offset printing ink is obtained by adding a pigment, a solvent for ink, and the like to gel varnish (hereinafter, sometimes referred to as (gel) varnish) and mechanically kneading. The ink is then supplied from the ink fountain via a plurality of rollers to the printing plate cylinder, and transferred to the printing paper via the blanket cylinder together with separately supplied dampening water to form an image.

  By the way, as described in Patent Document 1, as an ink solvent used for offset printing ink, in recent years, aliphatic hydrocarbons such as naphthene and paraffin are used from the viewpoint of air pollution, environmental problems, maintenance of work environment, and the like. Non-aromatic solvents as the main component have become mainstream.

  However, as pointed out in Patent Document 1, such non-aromatic solvents generally have a problem that the rosin-modified phenol resin has poor solubility and the gloss of the resulting offset printing ink film is lowered. In addition, offset printing is proceeding at higher speed than ever before, and in order to satisfy high-speed printing suitability such as misting resistance and low tackiness, it is indispensable to increase the molecular weight of rosin-modified phenolic resin.

  Therefore, in this field, there is a strong demand for a rosin-modified phenolic resin having a high molecular weight but excellent solubility in an aliphatic hydrocarbon solvent. In this respect, according to Patent Document 1, a rosin-modified phenolic resin meeting such a request is obtained by reacting rosins, phenol-formaldehyde condensates and polyols in the presence of an acidic catalyst such as paratoluenesulfonic acid. It is said that

  However, as a result of the study by the present inventors, it has been found that the offset printing ink obtained using the rosin-modified phenolic resin has insufficient fluidity. It is known that ink having insufficient fluidity causes a so-called fountain phenomenon that does not transfer from the ink fountain to the calling roller during printing, leading to a decrease in chromaticity of the printed matter.

JP-A-7-126338

  The present invention is for offset printing inks that are excellent in solubility in aliphatic hydrocarbon solvents while having a high molecular weight, and that can improve fluidity while maintaining misting resistance, drying properties and gloss of offset printing inks. The main object is to provide a novel rosin-modified phenolic resin.

  As a result of intensive studies, the present inventor has found that a rosin-modified phenol resin using a predetermined reaction product as a raw material is suitable as a binder for offset printing ink capable of solving the above-mentioned problems.

  That is, the present invention provides a reaction product (A) of a rosin (a1), a metal compound (a2), and an alkylphenol-formaldehyde condensate (a3) with a polyol (B) in the presence of a sulfonic acid catalyst (C). A rosin-modified phenol resin for offset printing inks having a weight average molecular weight of 20,000 to 150,000 obtained by esterification with a varnish, a gel varnish for offset printing inks obtained using the rosin-modified phenol resin, and the gel varnish The offset printing ink obtained by using.

  The rosin-modified phenolic resin according to the present invention dissolves well in an aliphatic hydrocarbon solvent as a printing ink solvent while having a high molecular weight, and gives a clear (gel) varnish without turbidity. The (gel) varnish does not use an aromatic solvent, and therefore is preferable from the viewpoint of air pollution, environmental problems, work environment maintenance, and the like. In addition, the offset printing ink obtained using the (gel) varnish is particularly excellent in fluidity, and is also excellent in misting resistance, low tackiness, dryness of ink film, and gloss, and is resistant to emulsification in dampening water. The property is also good.

  The rosin-modified phenolic resin of the present invention comprises a rosin (a1) (hereinafter referred to as component (a1)), a metal compound (a2) (hereinafter referred to as component (a2)), and an alkylphenol-formaldehyde condensate (a3). A polyol (B) (hereinafter referred to as component (B)) is added to a reaction product (A) (hereinafter referred to as component (A)) of the reaction product (hereinafter referred to as component (a3)) with a sulfonic acid catalyst (C). ) (Hereinafter referred to as component (C)), a high molecular weight composition obtained by esterification reaction.

  As the component (a1), for example, at least one natural rosin selected from the group consisting of gum rosin, tall oil rosin, wood rosin and the like, a polymerized rosin derived from the natural rosin, and a purified product of the natural rosin and polymerized rosin (Hereinafter, these rosins may be collectively referred to as raw material rosin.), Stabilized rosin (disproportionated rosin, hydrogenated rosin) obtained by disproportionating or hydrogenating the raw material rosin, Examples include unsaturated acid-modified rosin obtained by adding unsaturated carboxylic acids. Examples of unsaturated carboxylic acids include unsaturated monocarboxylic acids and unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, crotonic acid, cinnamic acid, acrylic acid and methacrylic acid. . The unsaturated acid-modified rosin is modified (Diels-Alder reaction) by using about 1 to 30 parts by weight of an unsaturated carboxylic acid with respect to 100 parts by weight of the raw material rosin. As the component (a1), one type may be used alone, or two or more types may be mixed and used.

  As the component (a2), various metal compounds such as oxides and hydroxides can be used. Specifically, divalent metal oxides and / or divalent metal hydroxides are preferable. Magnesium oxide, calcium oxide, zinc oxide and the like are used as the former, and magnesium hydroxide, calcium hydroxide and hydroxide are used as the latter. Zinc etc. can be illustrated. Moreover, these may combine 2 or more types. The amount of the component (a2) used is not particularly limited, but it is preferably 0 with respect to 100 parts by weight of the component (a1) from the viewpoint of increasing the molecular weight of the rosin-modified phenolic resin and the solubility in an aliphatic hydrocarbon solvent. About 1 to 5 parts by weight, preferably 0.5 to 3 parts by weight.

  As the component (a3), various known compounds can be used without particular limitation. Specifically, for example, a resol type phenol resin or a novolac type phenol resin can be mentioned. As the resol type phenol resin, phenols (P) and formaldehyde in the presence of a basic catalyst such as an organic amine or sodium hydroxide. Examples thereof include a condensate obtained by subjecting (F) to an addition / condensation reaction within a range in which F / P (molar ratio) is usually about 1 to 3. In addition, examples of the novolak type phenol resin include condensates obtained by addition / condensation reaction in the presence of an acidic catalyst such as hydrochloric acid or sulfuric acid within a range in which F / P is usually about 0.5 to 2. Each condensate is preferably neutralized and washed with water. Each condensate can be produced in the presence of water or an organic solvent (such as xylene). Examples of the phenols include carboxylic acid, cresol, amylphenol, bisphenol A, butylphenol, octylphenol, nonylphenol, and dodecylphenol. Examples of the formaldehyde include formalin and paraformaldehyde. In addition, as the component (a3), from the viewpoint of increasing the molecular weight of the rosin-modified phenol resin and the solubility in an aliphatic hydrocarbon solvent, the alkyl group has less than 10 carbon atoms, specifically, the alkyl group carbon. A condensate of alkylphenol and formaldehyde of about 4 to 9 is preferable. Further, the amount of the component (a3) used is not particularly limited, but usually from the viewpoint of increasing the molecular weight of the rosin-modified phenol resin and the solubility in an aliphatic hydrocarbon solvent, it is usually based on 100 parts by weight of the component (a1). About 10 to 130 parts by weight, preferably about 30 to 100 parts by weight.

  The component (A) is a reaction product of the components (a1) to (a3), but the reaction order is not particularly limited. Specifically, the method (a) in which the components (a1) to (a3) are reacted in one pot, or the method (a3) is reacted with the component (a2) after reacting the component (a2) with the component (a1) ( (B) Any of the methods (c) in which the component (a1) and the component (a3) are reacted and then the component (a2) is further reacted. Moreover, although reaction conditions are not specifically limited, Usually, reaction temperature is about 100-300 degreeC, and reaction time is about 1 to 24 hours. Even if the rosin-modified phenol resin is produced without using the component (a2) and then the component (a2) is added, the effect of the present invention cannot be obtained.

  As the component (B), various known compounds can be used without particular limitation. Specifically, for example, diols such as ethylene glycol, diethylene glycol, triethylene glycol, and neopentyl glycol, triols such as glycerin, trimethylolethane, and trimethylolpropane, and tetraols such as pentaerythritol, diglycerin, and ditrimethylolpropane. Examples thereof include polyols having five or more valences such as all and dipentaerythritol, and two or more kinds may be combined. Among the components (B), triols and / or tetraols are preferable from the viewpoints of increasing the molecular weight of the rosin-modified phenolic resin, the solubility in an aliphatic hydrocarbon solvent, the misting resistance of the printing ink, and the like.

The amount of the component (A) and the component (B) used is not particularly limited. In particular, from the viewpoint of increasing the molecular weight of the rosin-modified phenolic resin and the solubility in the aliphatic hydrocarbon solvent, and the misting resistance of the printing ink, Ratio of acid value of component (A) (AV (A)) (JIS-K5601) to hydroxyl value of component (B) (OH (B)) (JIS-K0070) (OH (B) / AV (A) ) Is in the range of about 0.5 to 1.5, preferably about 0.7 to 1.3.

  (C) component is a catalyst used when esterifying the carboxyl group in (A) component and the hydroxyl group in (B) component, for example, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, Examples thereof include orthotoluenesulfonic acid, metatoluenesulfonic acid, and paratoluenesulfonic acid. In addition, although the usage-amount of (C) component is not specifically limited, The total of (A) component and (B) component from viewpoints, such as the high molecular weight of rosin modified phenol resin, and the solubility to an aliphatic hydrocarbon solvent especially. The amount is usually about 0.01 to 0.5 parts by weight, preferably about 0.05 to 0.3 parts by weight with respect to 100 parts by weight. If the component (C) is not used, or if another esterification catalyst (metal oxide, metal hydroxide, etc.) is used instead of the component (C), the resulting rosin-modified phenolic resin has a high molecular weight. In addition, the solubility in the aliphatic hydrocarbon solvent becomes poor, which is not preferable.

  The conditions for the esterification reaction of the component (A) and the component (B) are not particularly limited, but usually the reaction temperature is about 100 to 300 ° C. and the reaction time is about 1 to 24 hours.

  The rosin-modified phenolic resin thus obtained is characterized by a high molecular weight. From the viewpoints of solubility in aliphatic hydrocarbon solvents and misting resistance and fluidity of printing ink, the weight average molecular weight (gel permeation chromatography) The value as a polystyrene conversion value by a graphic method) is usually about 20,000 to 150,000, preferably about 40,000 to 130,000.

  Further, as described above, the rosin-modified phenolic resin according to the present invention is excellent in solubility in an aliphatic hydrocarbon solvent. Specifically, the rosin-modified phenol resin has a cloud point (that is, a 10% by weight solution of an aliphatic hydrocarbon solvent having an aromatic content of less than 1% and an aniline point of 70 to 100 ° C. (ie, The temperature when turbidity is about 50 to 150 ° C, preferably 50 to 140 ° C. In the present invention, this cloud point is used as an indicator of solubility. Examples of the “aliphatic hydrocarbon solvent having an aromatic content of less than 1% and an aniline point of 70 to 100 ° C.” include, for example, No. 0 solvent or AF solvent (4 by JX Nippon Oil & Energy Corporation). No. 5, No. 6, No. 7, No. 7, etc.). The “10 wt% solution” of the aliphatic hydrocarbon solvent specifically refers to the rosin-modified phenol resin (solid) / AF solvent according to the present invention (a naphthenic fat manufactured by JX Nippon Mining & Energy Corporation). Group hydrocarbon solvent) = 1/9, and the AF solvent used is preferably No. 6.

  The other physical properties of the rosin-modified phenol resin are not particularly limited. For example, the 33% linseed oil viscosity is usually about 5 to 25 Pa · s, preferably 7 to 20 Pa · s, particularly from the viewpoint of misting resistance of the printing ink. It is about s.

  The softening point (JIS-K5903) is usually about 120 to 200 ° C., preferably about 140 to 200 ° C., particularly from the viewpoint of misting resistance and drying properties of printing ink.

  The acid value (JIS-K5601) is usually about 5 to 30 mgKOH / g, preferably 10 to 10% from the viewpoints of solubility of the rosin-modified phenolic resin in the aliphatic hydrocarbon solvent and emulsification resistance of the printing ink. 25 mg KOH / g.

  The gel varnish for offset printing ink of the present invention is obtained by reacting the rosin-modified phenol resin of the present invention and a gelling agent in a non-aromatic solvent (usually about 100 to 240 ° C.). Examples of the non-aromatic solvent include non-aromatic printing ink solvents such as various known aliphatic hydrocarbon solvents and / or vegetable oils.

  As the gelling agent, various known ones can be used without particular limitation. Specifically, for example, aluminum chelates such as aluminum octylate, aluminum stearate, aluminum triisopropoxide, aluminum tributoxide, aluminum dipropoxide monoacetyl acetate, aluminum dibutoxide monoacetyl acetate, aluminum triacetyl acetate, etc. And titanium-based chelating agents such as tetraisopropoxytitanium, tetrabutoxytitanium, dipropoxybis (acetylacetonato) titanium, zirconium-based chelating agents such as tetrabutoxyzirconium, tolylene diisocyanate, diphenyl diisocyanate, hexamethylene diisocyanate, xylylene diene Examples include isocyanates, polyisocyanates such as isophorone diisocyanate, etc. . Among these, an aluminum chelating agent is particularly preferable from the viewpoint of emulsification resistance of the printing ink. In addition, although the usage-amount of a gelatinizer is not specifically limited, It is about 0.5-5 weight part normally with respect to 100 weight part (solid content conversion) of the rosin modified phenol resin which concerns on this invention.

  Examples of the aliphatic hydrocarbon solvent include No. 0 solvent and AF solvent (No. 4, No. 5, No. 6, No. 7, etc.) of the above-mentioned JX Nippon Oil & Energy Corporation, and the aromatic content is 1 % Of the aniline point is preferably 70 to 100 ° C. Moreover, the thing whose boiling point is 200 degreeC or more is preferable from an environmental viewpoint. The amount of the aliphatic hydrocarbon solvent used is not particularly limited, but is usually about 10 to 200 parts by weight, preferably 10 to 150 parts by weight, based on 100 parts by weight (in terms of solid content) of the rosin-modified phenolic resin according to the present invention. About a part.

  Various known oils can be used without particular limitation as the vegetable oils. 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 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, and two or more of them may be combined. As the vegetable oils, vegetable oils containing a large amount of fatty acids having an unsaturated bond in the molecule, particularly soybean oil and / or linseed oil are preferable from the viewpoint of the dryness of the printed matter. In addition, although the usage-amount of this vegetable oil is not specifically limited, About 10-200 weight part normally with respect to 100 weight part (solid content conversion) of the rosin modified phenol resin which concerns on this invention, Preferably it is about 10-150 weight part. is there.

  When the aliphatic hydrocarbon solvent and vegetable oil are used in combination, the weight ratio of the aliphatic hydrocarbon solvent / vegetable oil is usually about 1/100 to 100/1, preferably about 5/60 to 20/50. Is preferable.

  The offset printing ink of the present invention contains the gel varnish of the present invention and a pigment (yellow, red, indigo, black), and after blending various known additives as necessary, roll mill, ball mill, attritor, sand mill These are used after being kneaded and prepared so as to obtain an appropriate ink constant using a known ink manufacturing apparatus. Examples of the additive include surfactants, waxes, antioxidants and the like for modifying the fluidity of the ink and the surface of the ink film.

  Hereinafter, the present invention will be described more specifically with reference to production examples and examples, but these do not limit the scope of the present invention. Hereinafter, “parts” and “%” are based on weight.

  The weight average molecular weight is a polystyrene conversion value measured in a tetrahydrofuran solvent by gel permeation chromatography (GPC). HLC-8220 (manufactured by Tosoh Corp.) is used as the GPC device, and TSK-GEL is used as the column. It is a measured value obtained using a column (manufactured by Tosoh Corporation).

  In addition, the cloud point was measured with an automatic cloud point measuring device (product name “CHEMOTORIC II”) manufactured by NOVOMATICS, using a solution in which rosin-modified phenol resin (solid) / AF solvent No. 6 = 1/9. Value.

  The 33% linseed oil viscosity (Pa · s) was obtained by mixing a resin and linseed oil at a weight ratio of 1: 2, using a cone and plate viscometer manufactured by Nippon Rheology Equipment Co., Ltd. It is the value measured at 25 ° C.

<Manufacture of (a3) component>
Production Example 1
A reaction vessel equipped with a stirrer, a reflux condenser with a water separator and a thermometer was charged with 1000 parts of nonylphenol, 444 parts of 92% paraformaldehyde, 604 parts of xylene and 500 parts of water, and the temperature was raised to 50 ° C. with stirring. . Next, 89 parts of 45% sodium hydroxide solution was charged into the same reaction vessel, the reaction system was gradually warmed up to 90 ° C. while cooling, then kept for 2 hours, and sulfuric acid was added dropwise to bring the pH to around 6. It was adjusted. Thereafter, the aqueous layer containing formaldehyde and the like was removed, washed again with water, and then the contents were cooled to obtain a 70% xylene solution of resol type nonylphenol resin (hereinafter referred to as component (a3-1)).

Production Example 2
A reaction vessel equipped with a stirrer, a reflux condenser with a water separator and a thermometer was charged with 1000 parts of octylphenol, 396 parts of 92% paraformaldehyde, 584 parts of xylene and 500 parts of water, and the temperature was raised to 50 ° C. with stirring. . Next, 89 parts of 45% sodium hydroxide solution was charged into the same reaction vessel, the reaction system was gradually warmed up to 90 ° C. while cooling, then kept for 2 hours, and sulfuric acid was added dropwise to bring the pH to around 6. It was adjusted. Thereafter, the aqueous layer containing formaldehyde and the like was removed, and after washing again with water, the contents were cooled to obtain a 70% xylene solution of resol type octylphenol resin (hereinafter referred to as component (a3-2)).

<Production of rosin-modified phenolic resin>
Example 1
A reaction vessel equipped with a stirrer, a reflux condenser with a water separator and a thermometer was charged with 1,000 parts of gum rosin, heated to 220 ° C. with stirring and melted, and then charged with 10 parts of zinc oxide for 1 hour. Keep warm. Subsequently, 1000 parts (700 parts of solid content) of the component (a3-1) obtained in Production Example 1 was dropped into the system over 6 hours. After completion of the dropwise addition, 93 parts of glycerin and 1 part of paratoluenesulfonic acid (hereinafter referred to as PTS) were charged, and the esterification reaction was carried out within the temperature range of 220 to 260 ° C. until the acid value of the reaction system became 25 or less. . The appearance of the resin solution in the reaction system was clear, and no turbidity was generated. Thereafter, the reaction system was depressurized at 0.02 MPa for 10 minutes and cooled to have a weight average molecular weight of 105,000, a cloud point of 98 ° C., a 33% linseed oil viscosity of 11.4 Pa · s, and an acid value of 19. As a result, 1,700 parts of a solid rosin-modified phenol resin having 8 mg KOH / g and a softening point of 170 ° C. were obtained.

Example 2
1,000 parts of gum rosin were charged into the same reaction vessel as in Example 1, and heated to 220 ° C. with melting, and then melted. Then, 10 parts of magnesium hydroxide was charged and kept warm for 1 hour. Subsequently, 857 parts (solid part 600 parts) of (a3-1) component were dripped in the system over 5 hours. After completion of the dropping, 93 parts of glycerin and 1 part of PTS were charged, and the esterification reaction was carried out within the temperature range of 220 to 260 ° C. until the acid value of the reaction system became 25 or less. The appearance of the resin solution in the reaction system was clear and no turbidity was generated. Thereafter, the reaction system was depressurized at 0.02 MPa for 10 minutes, so that the weight average molecular weight was 64,000, the cloud point was 85 ° C., the 33% linseed oil viscosity was 9.1 Pa · s, and the acid value was 20.1 mgKOH / g. As a result, 1,600 parts of a solid rosin-modified phenol resin having a softening point of 164 ° C. were obtained.

Example 3
1,000 parts of gum rosin was charged in the same reaction vessel as in Example 1, and the mixture was heated to 220 ° C. and melted with stirring. Next, after 857 parts of component (a3-2) (solid content of 600 parts) were dropped into the system over 5 hours, 10 parts of zinc oxide was added and the temperature was further kept for 1 hour. Subsequently, 93 parts of glycerin and 1 part of PTS were charged, and the esterification reaction was carried out within the temperature range of 220 to 260 ° C. until the acid value of the reaction system became 25 or less. The appearance of the resin solution in the reaction system was clear and no turbidity was generated. Thereafter, by reducing the pressure at 0.02 MPa for 10 minutes, the weight average molecular weight was 99,000, the cloud point was 105 ° C., the 33% linseed oil viscosity was 12.1 Pa · s, the acid value was 19.1 mgKOH / g, and the softening point. Obtained 1,600 parts of a solid rosin-modified phenolic resin at 183 ° C.

Example 4
1,000 parts of gum rosin was charged in the same reaction vessel as in Example 1, and the mixture was heated to 220 ° C. and melted with stirring. Next, 1000 parts of component (a3-2) (solid content: 600 parts) was dropped into the system over 5 hours, 10 parts of magnesium hydroxide was charged, and the temperature was further maintained for 1 hour. Subsequently, 93 parts of glycerin and 1 part of PTS were charged, and the esterification reaction was carried out within the temperature range of 220 to 260 ° C. until the acid value of the reaction system became 25 or less. The appearance of the resin solution in the reaction system was clear and no turbidity was generated. Thereafter, by reducing the pressure at 0.02 MPa for 10 minutes, the weight average molecular weight was 142,000, the cloud point was 109 ° C., the 33% linseed oil viscosity was 17.7 Pa · s, the acid value was 19.8 mgKOH / g, and the softening point. Obtained 1,700 parts of a solid rosin-modified phenolic resin at 189 ° C.

Comparative Example 1
After charging 1,000 parts of gum rosin in a reaction vessel similar to that in Example 1 and heating to 220 ° C. with melting, the mixture was melted with 857 parts (solid part 600 parts) for 5 hours. Over the course of the system. After completion of dropping, 93 parts of glycerin and 1 part of PTS were charged, and the esterification reaction was carried out within the temperature range of 220 to 270 ° C. until the acid value of the reaction system was 25 or less. The appearance of the resin solution in the reaction system was clear and no turbidity was generated. Thereafter, by reducing the pressure at 0.02 MPa for 10 minutes, the weight average molecular weight was 77,000, the cloud point was 110 ° C., the 33% linseed oil viscosity was 10.6 Pa · s, the acid value was 20.6 mgKOH / g, and the softening point. Obtained 1,600 parts of a solid rosin-modified phenolic resin at 180 ° C.

Comparative Example 2
1,000 parts of gum rosin were charged in the same reaction vessel as in Example 1, heated to 220 ° C. with melting, and then melted, 10 parts of zinc oxide was charged and kept warm for 1 hour. Next, 1000 parts of component (a3-1) (700 parts of solid content) was dropped into the system over 6 hours. After the completion of the dropping, only 93 parts of glycerin was charged, and the esterification reaction was carried out within the temperature range of 220 to 260 ° C. until the acid value of the reaction system became 25 or less. The appearance of the resin solution in the reaction system was clear and no turbidity was generated. Thereafter, by reducing the pressure at 0.02 MPa for 10 minutes, the weight average molecular weight was 97,000, the cloud point was 110 ° C., the 33% linseed oil viscosity was 11.0 Pa · s, the acid value was 20.5 mgKOH / g, and the softening point. Obtained 1,700 parts of a solid rosin-modified phenol resin at 168 ° C.

Comparative Example 3
1,000 parts of gum rosin was charged into the same reaction vessel as in Example 1, and heated to 220 ° C. with melting, and then 1 part of PTS was charged and kept warm for 1 hour. Next, 1000 parts of component (a3-1) (700 parts of solid content) was dropped into the system over 6 hours. After completion of dropping, 93 parts of glycerin and 10 parts of zinc oxide as an esterification catalyst were charged, and the esterification reaction was carried out within a temperature range of 220 to 260 ° C. until the acid value became 25 or less. However, turbidity due to insoluble matter was observed in the resin solution of the reaction system. Thereafter, by reducing the pressure at 0.02 MPa for 10 minutes, the weight average molecular weight was 38,000, the 33% flaxseed oil viscosity was 6.2 Pa · s, the acid value was 24.7 mgKOH / g, and the softening point was 150 ° C. 1,700 parts of rosin-modified phenolic resin was obtained. In addition, as mentioned above, since insoluble matter was observed in the rosin-modified phenol resin solution before the decompression treatment, the rosin-modified phenol resin was not measured for cloud point and was not used for preparation of a gel varnish described later.

Comparative Example 4
1,000 parts of gum rosin were charged into the same reaction vessel as in Example 1, and heated to 220 ° C. with melting, and then melted. Then, 10 parts of magnesium hydroxide was charged and kept warm for 1 hour. Subsequently, 857 parts (600 parts of solid content) of 70% xylene solution of the component (a3-1) was dropped into the system over 5 hours. After the completion of the dropping, only 93 parts of glycerin was charged and reacted until the acid value of the reaction system became 25 or less within a temperature range of 220 to 260 ° C. The appearance of the resin solution in the reaction system was clear and no turbidity was generated. Thereafter, by reducing the pressure at 0.02 MPa for 10 minutes, the weight average molecular weight was 62,000, the cloud point was 96 ° C., the 33% linseed oil viscosity was 8.4 Pa · s, the acid value was 21.0 mgKOH / g, and the softening point. Of 1,600 parts of a solid rosin-modified phenolic resin at 160 ° C.

Comparative Example 5
1,000 parts of gum rosin was charged in the same reaction vessel as in Example 1, and the mixture was heated to 220 ° C. and melted with stirring. Subsequently, 857 parts of (a3-1) component (600 parts of solid content) were dripped in the system over 5 hours. After the completion of the dropping, only 93 parts of glycerin was charged and reacted until the acid value of the reaction system became 25 or less within a temperature range of 220 to 260 ° C. The appearance of the resin solution in the reaction system was clear and no turbidity was generated. Thereafter, by reducing the pressure at 0.02 MPa for 10 minutes, the weight average molecular weight was 43,000, the cloud point was 100 ° C., the 33% linseed oil viscosity was 6.5 Pa · s, the acid value was 24.5 mgKOH / g, and the softening point. Obtained 1,600 parts of a solid rosin-modified phenolic resin at 155 ° C.

<Preparation of gel varnish>
45.0 parts of rosin modified phenolic resin of Example 1, 10.0 parts of linseed oil and AF solvent 7 (manufactured by JX Nippon Oil & Energy Corporation, boiling range 259-282 ° C., aromatic hydrocarbon content 0% 44.0 parts were mixed and dissolved at 200 ° C. for 30 minutes. Next, after cooling to 80 ° C., 1.0 part of aluminum dipropoxide monoacetylacetate (trade name Kerope EP-2, manufactured by Hope Pharmaceutical Co., Ltd.) is added and heated to 200 ° C. to gel for 1 hour. The gel varnish was obtained by making it react. Gel varnishes were similarly prepared for the rosin-modified phenolic resins of other Examples and Comparative Examples 1 and 3-5.

<Preparation of printing ink and ink performance test>
Using the gel varnishes of the examples and comparative examples, the mixture was kneaded by a three roll mill at the following blending ratio, the C & P viscosity at 25 ° C. was 25 ± 5 Pa · s, and the flow value (diameter value) of the spread meter at 25 ° C. was 36. A printing ink was prepared to give 0.0 ± 1.0.
Phthalocyanine blue (indigo pigment) 18 parts by weight Gel varnish 63-71 parts by weight AF Solvent No. 7 11-19 parts by weight

(Liquidity)
In a room air-conditioned at 25 ° C., 1.3 ml of ink was placed on the upper end of a glass plate forming an angle of 60 ° C. with the ground plane, and the distance of flowing for 30 minutes was measured. The larger the value, the better the fluidity.

(Emulsification rate)
After 3.9 ml of ink was developed on a dynamic emulsification tester (manufactured by Nippon Rheology Equipment Co., Ltd.), pure water was supplied at a roll temperature of 30 ° C. and 200 rpm at a rate of 5 ml / min. The amount was measured with an infrared moisture meter. The smaller the value, the better the emulsification resistance.

(Missing)
2.6 ml of ink is spread on an incometer (manufactured by Toyo Seiki Seisakusho Co., Ltd.), rotated at a roll temperature of 30 ° C. for 1 minute at 400 rpm, and further rotated at 1800 rpm for 2 minutes. The scattering degree was observed and evaluated in 1 to 5 stages. The larger the value, the better the misting resistance.

(Tack value)
1.3 ml of ink was spread on an incometer (manufactured by Toyo Seiki Seisakusho), and the tack value after 1 minute was measured under the conditions of a roll temperature of 30 ° C. and 400 rpm. The lower the tack value, the less paper peeling and the higher the high-speed printing suitability.

(Drying)
After 0.4 ml of ink was developed on art paper with an RI tester (Ishikawajima Industrial Machinery Co., Ltd.), it was exposed to an atmosphere of 160 ° C. for 2 seconds, 4 seconds, and 6 seconds, respectively. The condition was judged as dry. Evaluation is performed in 1 to 5 stages, and the smaller the value, the better the drying property.

(Glossy)
After 0.4 ml of ink was developed on art paper using an RI tester (manufactured by Ishikawajima Industrial Machinery Co., Ltd.), 23 ° C., 50% R.D. H. For 24 hours, and the reflectance of 60 ° -60 ° was measured with a gloss meter. The larger the value, the better the gloss.

Claims (10)

The reaction product (A) of the rosins (a1), metal compound (a2), and alkylphenol-formaldehyde condensate (a3) is esterified with the polyols (B) in the presence of the sulfonic acid catalyst (C). A rosin-modified phenol resin for offset printing ink having a weight average molecular weight of 20,000 to 150,000. The rosin-modified phenol resin for offset printing ink according to claim 1, wherein the component (a1) is at least one natural rosin selected from the group consisting of gum rosin, tall oil rosin, and wood rosin. The rosin-modified phenol resin for offset printing ink according to claim 1 or 2, wherein the component (a2) is a divalent metal oxide and / or a divalent metal hydroxide. The rosin-modified phenol resin for offset printing ink according to any one of claims 1 to 3, wherein the component (a3) is a condensate of an alkylphenol having an alkyl group with less than 10 carbon atoms and formaldehyde. The rosin-modified phenol resin for offset printing ink according to any one of claims 1 to 4, wherein the amount of component (a2) used is 0.1 to 5 parts by weight relative to 100 parts by weight of component (a1). The rosin-modified phenol resin for offset printing ink according to any one of claims 1 to 5, wherein the component (B) is a triol and / or a tetraol. The clouding point in the case where the aromatic content is less than 1% and the 10% by weight solution of an aliphatic hydrocarbon solvent having an aniline point of 70 to 100 ° C is 50 to 150 ° C. Rosin-modified phenolic resin for offset printing ink. A gel varnish for offset printing ink obtained by reacting the rosin-modified phenolic resin according to any one of claims 1 to 7 and a gelling agent in a non-aromatic solvent. The gel varnish for offset printing ink according to claim 8, wherein the non-aromatic solvent is an aliphatic hydrocarbon solvent and / or a vegetable oil. An offset printing ink comprising the gel varnish for offset printing ink according to claim 8 or 9 and a pigment.