JP2008274150A - Rosin-modified phenolic resin and rosin-modified phenolic resin for offset printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rosin-modified phenolic resin which improves stain of printing plates and is excellent in temporal stability, and a rosin-modified phenolic resin for offset printing obtained using the resin. <P>SOLUTION: The rosin-modified phenolic resin is obtained by reacting purified rosins (a), a condensate of phenols and formaldehyde (b) and a polyol (c) and has a metal content of ≤10 ppm. The rosin-modified phenolic resin is obtained by reacting purified rosins (a), a condensate of phenols and formaldehyde (b), a polyol (c) and at least one chosen from a polybasic acid (d), an epoxy compound (e) and a polyfunctional acrylate (f) and has a metal content of ≤10 ppm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a rosin-modified phenol resin and a rosin-modified phenol resin for offset printing.

  Rosin-modified phenolic resin is a resin obtained by reacting rosins with phenolic resins, polyols, etc., and has various properties such as high molecular weight, high softening point, high viscosity, high solubility in ink solvents, and printing. Since it is excellent in aptitude, it is widely used as a resin for printing ink, particularly as a resin for offset printing.

Since offset printing uses a repulsion between dampening water and ink and prints by forming image areas and non-image areas, the emulsified state of dampening water and ink greatly affects the quality of printed matter. give. As a trouble related to emulsification, there is a phenomenon such as “plate stain” in which a non-image area of a plate is sensitized and ink adheres to the print to cause stains.

As a means for improving “plate stain”, a printing ink composition using an α-olefin polymer without using a rosin-modified phenol resin (for example, see Patent Document 1) or a specific production method was used. A printing ink varnish using a rosin-modified phenolic resin (for example, see Patent Document 2) has been proposed.

By the way, rosin-modified phenolic resins are usually obtained by reacting rosins with phenolic resins, polyols, etc., but at the time of producing phenolic resins, resorching catalysts containing sodium, potassium, calcium, etc. are used. Since the esterification catalyst containing magnesium, calcium, zinc or the like is used when reacting the phenol with the phenol resin or polyol, the resulting rosin-modified phenol resin contains a lot of metal salts and the like.

Therefore, paying attention to the content of this metal, emulsification speed and the like by using a rosin-modified phenol resin having an alkali and / or alkaline earth metal content of 200 ppm or less as the rosin-modified phenol resin with a small amount of residual metal. Has been proposed (for example, see Patent Document 3). However, in this method as well, plate stains cannot be completely eliminated, and in Patent Document 3, specifically, alkali and / or alkaline earth is more specifically described. No rosin-modified phenolic resin having a significantly reduced metal content and its means have been disclosed.

  In addition, printing ink is known to change over time, which has the problem of affecting printability. Therefore, a method for improving by adding an additive comprising a quaternary ammonium salt salt of a pigment acid (see, for example, Patent Document 4), printing based on rosin-modified phenolic resin, rice bran oil, fatty acid monoester A method for suppressing auto-oxidation by using ink (for example, see Patent Document 5) has been proposed. One of the causes of the change over time is considered to be a thickening of the printing ink varnish.

JP 2005-290084 A JP 2005-272694 A JP 2004-137442 A JP 7-292305 A JP 2005-330317 A

An object of the present invention is to provide a rosin-modified phenolic resin that improves plate stains and is excellent in stability over time, and a rosin-modified phenolic resin for offset printing obtained using the resin.

As a result of intensive studies to improve the plate stain and stability over time, the present inventors have found that plate stain is caused by dissolution of ion-bonded metal salts contained in the rosin-modified phenolic resin in the fountain solution. It is found that the change with time is caused by the fact that the metal acts as an oxidation catalyst, and it is prepared using a raw material from which the metal compound has been removed, and without using a metal compound as an esterification catalyst or a resolation catalyst, or a metal compound It was found that the above problems could be solved by removing these metal components and using a rosin-modified phenolic resin with a significantly reduced metal content even when using the above.

That is, the present invention provides a rosin-modified phenolic resin having a metal content of 10 ppm or less obtained by reacting a purified rosin (a), a phenol-formaldehyde condensate (b) and a polyol (c); (A) Reaction of at least one selected from the group consisting of phenols and formaldehyde condensates (b), polyols (c), polybasic acids (d), epoxy compounds (e) and polyfunctional acrylates (f) The present invention relates to a rosin-modified phenol resin having a metal content of 10 ppm or less, and a rosin-modified phenol resin for offset printing containing the rosin-modified phenol resin.

By using the rosin-modified phenolic resin of the present invention, it is possible to obtain a binder for offset printing that can improve plate stain and stability over time. In addition, printing inks using the rosin-modified phenolic resin of the present invention are used as offset printing inks such as offset sheet-fed ink (sheet-fed ink), offset rotary ink (off-wheel ink), waterless offset ink and the like. In addition, it is also suitably used for newspaper ink, letterpress printing ink, and gravure printing ink.

  The rosin-modified phenolic resin of the present invention comprises a purified rosin (a) (hereinafter referred to as component (a)), a phenol / formaldehyde condensate (b) (hereinafter referred to as component (b)), polyol (c) ( Hereinafter referred to as component (c)), if necessary, polybasic acid (d) (hereinafter referred to as component (d)), epoxy compound (e) (hereinafter referred to as component (e)), polyfunctional acrylate (f) (Hereinafter referred to as component (f)) is reacted.

The component (a) is not particularly limited as long as it is a purified rosin having a metal content of 10 ppm or less, and known components can be used. Specifically, for example, purified rosin such as purified gum rosin, purified wood rosin, purified tall oil rosin; polymerized rosin derived from the purified rosin; stable obtained by disproportionating or hydrogenating the purified rosin or polymerized rosin Unsaturation obtained by adding unsaturated carboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, crotonic acid, cinnamic acid, acrylic acid, methacrylic acid to the purified rosin or polymerized rosin An acid-modified rosin can be used. These may be used alone or in combination of two or more. Here, purification means removing the metal contained in the unpurified rosin as a starting material. Specifically, at least one of operations such as distillation and extraction may be performed, and distillation is preferably performed from the viewpoint of complete removal of metal. Distillation may be appropriately selected from the range of a temperature of 200 to 300 ° C. and a pressure of 130 to 6000 Pa in consideration of the distillation time. For extraction, rosin is dissolved in an organic solvent and water, treated with an acid such as sulfuric acid or hydrochloric acid, and then washed with water until the metal content is 10 ppm or less.

As component (b), phenols (P) and formaldehyde (F) were subjected to an addition / condensation reaction in the presence of a basic catalyst within a range where the F / P (molar ratio) was usually about 1 to 3. Condensates (resol-type phenol resins), phenols (P) and formaldehyde (F) within a range where the F / P (molar ratio) is usually about 0.5 to 2, oxalic acid, sulfuric acid, hydrochloric acid, para A condensate (novolak-type phenol resin) obtained by addition / condensation reaction in the presence of an acid catalyst such as toluenesulfonic acid and having a metal content of 10 ppm or less can be used. Examples of the phenols (P) used in the preparation of the component (b) include carboxylic acid, cresol, amylphenol, bisphenol A, butylphenol, octylphenol, nonylphenol, and dodecylphenol. These may be used alone or in combination of two or more. Moreover, as formaldehyde (F), formalin, paraformaldehyde, etc. may be used, for example. As the basic catalyst, a basic catalyst containing a metal component such as sodium hydroxide, potassium hydroxide or calcium hydroxide, or a known catalyst such as a volatile base catalyst can be used, but a base containing a metal component can be used. When a volatile catalyst is used, since it is necessary to perform washing until the metal content in the component (b) is 10 ppm or less, it is preferable to use a volatile basic catalyst. As the volatile base catalyst, those having a boiling point or decomposition temperature of usually about 220 ° C. or lower are particularly preferred. Specifically, ammonia generating substances such as aqueous ammonia and hexamethylenetetramine; aliphatic primary amines such as methylamine, ethylamine, propylamine, butylamine, amylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine; dimethyl Aliphatic secondary amines such as amine, diethylamine, dipropylamine, dibutylamine and diamylamine; Aliphatic tertiary amines such as trimethylamine and triethylamine; Aliphatic unsaturated amines such as allylamine, diallylamine and triallylamine; cyclopropylamine , Cyclobutylamine, cyclohexylamine, and other alicyclic amines; benzylamine, phenylamine, and other aromatic amines; other pyridines, piperazines, piperidines Pyrazines, and the like aniline. These may be used alone or in combination of two or more. Among these, diethylamine, trimethylamine, triethylamine and the like are preferable from the viewpoints of catalyst activity, boiling point, safety, and handleability.

As the component (b), a resol-type phenol resin is preferable from the viewpoint of increasing the molecular weight of the rosin-modified phenol resin. Although it does not specifically limit as manufacturing conditions of this resol type phenol resin, It is preferable that the resolumination temperature shall be about 80-200 degreeC. When it is less than 80 ° C., the resolation reaction rate is extremely slow, and when it exceeds 200 ° C., it is difficult to control the resolation reaction. When the resolation reaction is carried out in the above temperature range, formaldehyde is vaporized and the reaction product water boils, so that the reaction vessel used preferably has a pressure resistant specification.

As a component (c), if it contains two or more hydroxyl groups in 1 molecule, it will not specifically limit, A well-known thing can be used. Specifically, for example, the bifunctional alcohols include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, neopentyl glycol, cyclohexane dimethanol, and the trifunctional alcohols include glycerin and trimethylol. Examples of the tetrafunctional or higher functional alcohols such as propane and trimethylolethane include pentaerythritol, diglycerin, dipentaerythritol, ditrimethylolpropane, and ditrimethylolethane. These may be used alone or in combination of two or more. As the component (c), a compound having at least three hydroxyl groups in one molecule is preferable because the rosin-modified phenolic resin has a network structure and can have a high molecular weight.

The component (d) may be used when a high molecular weight is necessary, and any known compound may be used as long as it is a compound having two or more carboxyl groups in one molecule other than the component (a). it can. Examples of the component (d) include aromatic polybasic acids such as phthalic anhydride, isophthalic acid, terephthalic acid and trimellitic acid, and aliphatic polybasic acids such as alkenyl succinic anhydride, adipic acid, sebacic acid and dimer acid. Examples include basic acids. These may be used alone or in combination of two or more.

The component (e) may be used when a high molecular weight is necessary, and any known compound may be used as long as it is a compound having two or more epoxy groups in one molecule. For example, neopentyl glycol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, resorcinol diglycidyl ether, diglycidyl phthalate, epoxidized linseed oil, epoxidized soybean oil, etc. it can. These may be used alone or in combination of two or more.

  The component (f) may also be used when a high molecular weight is necessary, and any known component can be used without any particular limitation. Specifically, for example, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, bisphenol A tetraethylene glycol diacrylate, hexamethylene glycol diacrylate, 1,9-nonane. Various known polyfunctional acrylic monomers such as diol diacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate can be given. These may be used alone or in combination of two or more.

The ratio of each of the component (a), component (b), and component (c) constituting the rosin-modified phenolic resin of the present invention is not particularly limited and may be appropriately determined depending on the use. The use ratio of (a) is about 41 to 89% by weight, preferably about 46 to 73% by weight, and the use ratio of component (b) is about 9 to 50% by weight, preferably about 22 to 46% by weight. The proportion of component (c) used is about 2 to 9% by weight, preferably about 3 to 8% by weight.

Although the usage-amount in the case of using a component (d) is not specifically limited, When the total usage-amount of the said component (a)-(c) is 100 weight part, it is about 0.5-20 weight part. Moreover, the usage-amount in the case of using a component (e) is although it does not specifically limit, When the total usage-amount of the said component (a)-(c) is 100 weight part, it is about 0.5-10 weight part. is there. Further, the amount of use in the case of using the component (f) is not particularly limited, but is about 0.5 to 20 parts by weight when the total use amount of the components (a) to (c) is 100 parts by weight. .

Next, for example, the rosin-modified phenolic resin of the present invention is charged with a predetermined amount of component (a), component (b) and component (c) in a reactor, and the temperature range of about 150 to 300 ° C. for 1 to 20 hours. React to a certain extent. When component (d) to component (f) are used, the timing of addition is not particularly limited, but it may be usually added at the start of the reaction or during the reaction. During the reaction, various known organic acidic catalysts may be used as necessary. For example, sulfonic acids such as methanesulfonic acid, paratoluenesulfonic acid, dodecylbenzenesulfonic acid, and phosphorus compounds such as phosphoric acid may be used. it can.

The softening point of the rosin-modified phenolic resin of the present invention having a metal content of 10 ppm or less by the reaction method is preferably about 120 to 200 ° C, more preferably 140 to 200 ° C. This is because when the softening point is 120 ° C. or higher, it is possible to maintain good drying and setting properties of the printed matter, and 200 ° C. or lower is appropriate considering the solubility in the ink solvent. is there. The weight average molecular weight of the rosin-modified phenolic resin of the present invention is preferably about 10,000 to 400,000, more preferably 20,000 to 200,000. When it is less than 10,000, it is difficult to obtain a desired viscosity, and when it is more than 400,000, insoluble matter in the ink solvent tends to be generated. The solubility of the rosin-modified phenolic resin of the present invention is good, and it has sufficient solubility in an ink solvent that does not contain an aromatic component.

A resin varnish can be produced by adding a vegetable oil, a solvent for ink, and the like to a rosin-modified phenolic resin having a metal content of 10 ppm or less, if necessary, and mixing them.

As vegetable oils used for the resin varnish, various known oils can be used without limitation. Specifically, for example, flaxseed oil, tung oil, safflower oil, dehydrated castor oil, soybean oil and other vegetable oils, flaxseed oil fatty acid methyl, soybean oil fatty acid methyl, flaxseed oil fatty acid ethyl, soybean oil fatty acid ethyl, flaxseed oil Examples thereof 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. These may be used alone or in combination of two or more. In these, the vegetable oil which has an unsaturated bond in a molecule | numerator from the point of the drying property of printed matter is preferable, and soybean oil is especially preferable from the point with a small load with respect to an environment. In addition, it is preferable to remove the metal component from the vegetable oils by distillation or the like.

As the ink solvent used in the resin varnish, a conventionally known ink solvent can be used without any particular limitation. Specifically, for example, No. 0 Solvent, No. 4, Solvent No. 5, No. 5 Solvent, No. 6 Solvent, No. 7 Solvent, AF Solvent No. 4, AF Solvent No. 5, which are petroleum solvents manufactured by Nippon Oil Corporation, Examples include AF solvent 6 and AF solvent 7. These may be used alone or in combination of two or more. In particular, it is preferable to use an AF solvent having a boiling point of 200 ° C. or more and an aromatic hydrocarbon content of 1% by weight or less from the viewpoint of environmental measures. When printing ink with reduced environmental load is required, only vegetable oils may be used without using ink solvents. In addition, it is preferable to remove the metal component from the ink solvent by distillation or the like.

  The resin varnish can be manufactured by mixing and stirring the above components, but when mixing and stirring, these components are heated to about 100 to 240 ° C. to dissolve and mix the components. Depending on the use of additives. Examples of the additive include an antioxidant as well as a gelling agent for imparting elasticity.

Examples of the gelling agent include aluminum octylate, aluminum stearate, aluminum triisopropoxide, aluminum tributoxide, aluminum dipropoxide monoacetyl acetate, aluminum dibutoxide monoacetyl acetate, aluminum triacetyl acetate, tetraisopropoxy. Various known materials such as titanium, tetrabutoxytitanium, dipropoxybis (acetylacetonato) titanium, tetrabutoxyzirconium, epoxy compound of component (e), tolylene diisocyanate, diphenyl diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate Can be used without any particular limitation. These may be used alone or in combination of two or more. From the viewpoint of improving plate stains, a compound that does not form an ionic bond after the production of the resin varnish is preferable. Specifically, it is preferable to use the aluminum compound, epoxy compound, or isocyanate.

The printing ink contains pigments (yellow, red, indigo or black), the resin varnish, and various known additives, if necessary, known inks such as a roll mill, ball mill, attritor, and sand mill. It is obtained by kneading and preparing the ink so as to obtain an appropriate ink constant using a production apparatus. Examples of the additives include surfactants for improving ink fluidity and ink surface coating, and waxes.

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

Production Example 1: (Production of purified rosin)
In a reaction vessel equipped with a stirrer, a thermometer, and a decompressor, unpurified Chinese gum rosin (residual metal amount 22 ppm (Al), 7 ppm (Ca), 13 ppm (Fe), acid value 170.0, softening point 78 ° C.) 1 1,000 parts were charged and the temperature was raised to 190 ° C. with stirring in a nitrogen atmosphere. Thereafter, distillation was performed under reduced pressure of 400 Pa, the temperature was raised to 280 ° C., and a fraction at 210 to 280 ° C. was used as a purified rosin. The purified rosin obtained had a metal content of 0 ppm, an acid value of 178.4, and a softening point of 88 ° C. Here, atomic absorption analyzer type 5100 (manufactured by Perkin Elmer) was used for measuring the metal content (hereinafter, the metal content is a value measured by the same method). The acid value is based on JIS K5601 (hereinafter, the acid value is a value measured by the same method). The softening point is based on JIS K5903 (hereinafter, the softening point is a value measured by the same method).

Production Example 2: (Production of 70% resol-type p-nonylphenol xylene solution using a volatile base catalyst)
After charging 1,000 parts of p-nonylphenol and 300 parts of paraformaldehyde into a 1.5 MPa pressure-resistant reaction vessel equipped with a stirrer, an internal pressure gauge, and a thermometer, and dissolving them while raising the temperature to 80 ° C. under hermetically pressurized, 40 parts of triethylamine was added. Next, the temperature was raised to 125 ° C., kept for 30 minutes, and then cooled to 90 ° C. After depressurization, 300 parts of xylene was charged, and the contents were cooled to obtain a 70% xylene solution (solid content: 70%) of resol-type p-nonylphenol. The metal content was 0 ppm.

Production Example 3: (Production of 70% resol-type p-nonylphenol xylene solution using a basic metal catalyst)
A reaction vessel equipped with a stirrer, a reflux condenser and a thermometer was charged with 1,000 parts of p-nonylphenol, 476 parts of paraformaldehyde, 600 parts of xylene and 500 parts of water, and the temperature was raised to 50 ° C. with stirring. Then, 10 parts of calcium hydroxide was added at 50 ° C., and the temperature was gradually raised to 90 ° C. while cooling. Then, the mixture was kept warm for 2.5 hours, and hydrochloric acid was added dropwise to adjust the pH to around 6. Thereafter, the aqueous layer containing formaldehyde and the like was removed, and the contents were cooled to obtain a 70% xylene solution (solid content 70%) of resol-type p-nonylphenol. The metal content was 31 ppm (Ca).

Example 1: (Production of rosin-modified phenolic resin from resol-type phenolic resin using purified rosin and volatile base catalyst)
Into a reaction vessel equipped with a stirrer, a reflux condenser with a water separator and a thermometer, 552 parts of the purified rosin obtained in Production Example 1 was charged, and the mixture was heated to 200 ° C. with stirring in a nitrogen atmosphere and melted. . Next, 52 parts of pentaerythritol was added, the temperature was raised to 280 ° C. with stirring, and the reaction was continued until the acid value was 25 or less. After further cooling to 230 ° C., 394 parts of a 70% xylene solution of resole-type p-nonylphenol obtained in Production Example 2 (276 parts of solid content) was dropped into the system over 5 hours within a temperature range of 230 to 250 ° C. did. After completion of dropping, the viscosity of 33% by weight linseed oil was adjusted to 5.0 Pa · s, and after decompression at 0.02 MPa for 10 minutes, the contents were taken out to obtain a rosin-modified phenolic resin. The metal content of the resin is 0 ppm, the tolerance of the aromatic hydrocarbon solvent (trade name: 0 Solvent H, manufactured by Nippon Oil Corporation) is 3.2 g / g, and the acid value is 17.2. The softening point was 147 ° C. and the weight average molecular weight was 39,000. Here, the 33% linseed oil viscosity is the viscosity measured at 25 ° C. using a cone and plate viscometer made by Nippon Rheology Equipment Co., Ltd. with a mixture of resin and linseed oil heated in a 1 to 2 weight ratio. (Hereinafter, 33% linseed oil viscosity is a value measured by the same method). The tolerance (solubility index) is the total solvent required until the solution and No. 0 solvent H are heated and mixed at a 1 to 1 weight ratio and further added to No. 0 solvent H at 25 ° C to become cloudy. It is a value calculated from the resin weight relative to the weight (hereinafter, tolerance is a value measured by the same method). Moreover, the gel permeation chromatography (trade name HLC-8020) manufactured by Tosoh Corporation and the column (trade name TSK-GEL) manufactured by Tosoh Corporation were used for the weight average molecular weight measurement (hereinafter, the weight average molecular weight is It is a value measured by the same method).

Example 2: (Production of rosin-modified phenolic resin from resol-type phenolic resin using purified rosin and volatile base catalyst)
In a reaction vessel similar to that in Example 1, 552 parts of the purified rosin obtained in Production Example 1 was charged, and this was heated to 200 ° C. with stirring in a nitrogen atmosphere and melted. Next, 51 parts of glycerin was added, and the temperature was raised to 250 ° C. with stirring. 2 parts of isophthalic acid was added at 250 ° C., the temperature was raised to 280 ° C., and the reaction was continued until the acid value became 25 or less. After further cooling to 230 ° C., 394 parts of a 70% xylene solution of resole-type p-nonylphenol obtained in Production Example 2 (276 parts of solid content) was dropped into the system over 5 hours within a temperature range of 230 to 250 ° C. did. After completion of dropping, the viscosity of 33% by weight linseed oil was adjusted to 5.0 Pa · s, and after decompression at 0.02 MPa for 10 minutes, the contents were taken out to obtain a rosin-modified phenolic resin. The resin has a metal content of 0 ppm, an aromatic hydrocarbon solvent (trade name: 0 Solvent H, manufactured by Nippon Oil Corporation) has a tolerance of 2.5 g / g, and an acid value of 16.8. The softening point was 147 ° C. and the weight average molecular weight was 42,000.

Example 3: (Production of rosin-modified phenolic resin from resol-type phenolic resin using purified rosin and volatile base catalyst)
In a reaction vessel similar to that in Example 1, 552 parts of the purified rosin obtained in Production Example 1 was charged, and this was heated to 200 ° C. with stirring in a nitrogen atmosphere and melted. Next, 48 parts of glycerin and 4 parts of trimethylolpropane polyglycidyl ether were added, the temperature was raised to 280 ° C. with stirring, and the reaction was continued until the acid value became 25 or less. After further cooling to 230 ° C., 394 parts of a 70% xylene solution of resole-type p-nonylphenol obtained in Production Example 2 (276 parts of solid content) was dropped into the system over 5 hours within a temperature range of 230 to 250 ° C. did. After completion of dropping, the viscosity of 33% by weight linseed oil was adjusted to 5.0 Pa · s, and after decompression at 0.02 MPa for 10 minutes, the contents were taken out to obtain a rosin-modified phenolic resin. The resin has a metal content of 0 ppm, and an aromatic hydrocarbon solvent (trade name: 0 Solvent H, manufactured by Nippon Oil Corporation) has a tolerance of 2.7 g / g and an acid value of 16.5. The softening point was 144 ° C. and the weight average molecular weight was 48,000.

Example 4: (Production of rosin-modified phenolic resin from resol-type phenolic resin using purified rosin and volatile base catalyst)
In a reaction vessel similar to that in Example 1, 552 parts of the purified rosin obtained in Production Example 1 was charged, and this was heated to 200 ° C. with stirring in a nitrogen atmosphere and melted. Next, 52 parts of pentaerythritol was added, the temperature was raised to 280 ° C. with stirring, and the reaction was continued until the acid value was 25 or less. After further cooling to 230 ° C., 1 part of trimethylolpropane triacrylate was added, and 394 parts of a 70% xylene solution of resole-type p-nonylphenol obtained in Production Example 2 (276 parts of solid content) was heated to 230 to 250 ° C. It dripped in the system over 5 hours within the range. After completion of dropping, the viscosity of 33% by weight linseed oil was adjusted to 5.0 Pa · s, and after decompression at 0.02 MPa for 10 minutes, the contents were taken out to obtain a rosin-modified phenolic resin. The resin had a metal content of 0 ppm, and an aromatic hydrocarbon solvent (trade name: 0 Solvent H, manufactured by Nippon Oil Corporation) had a tolerance of 2.5 g / g and an acid value of 17.8. The softening point was 149 ° C. and the weight average molecular weight was 47,000.

Example 5: (Production of rosin-modified phenolic resin from resol-type phenolic resin using purified rosin, basic metal catalyst and basic metal catalyst)
In Example 1, instead of the resol type phenol resin obtained in Production Example 2, 197 parts of the resol type phenol resin obtained in Production Example 2 (solid part: 138 parts) and 197 parts of the resol type phenol resin obtained in Production Example 3 A rosin-modified phenolic resin was produced in the same manner except that (solid content of 138 parts) was used. In addition, the metal content of the resin is 8 ppm (Ca), the tolerance of the aromatic hydrocarbon solvent (trade name: 0 Solvent H, manufactured by Shin Nippon Oil Co., Ltd.) is 3.1 g / g, and the acid value is The softening point was 146 ° C., and the weight average molecular weight was 38,000.

Comparative Example 1: (Production of rosin-modified phenolic resin from resol-type phenolic resin using raw rosin and basic metal catalyst)
In Example 1, in place of the purified rosin and the resol type phenol resin obtained in Production Example 2, an unpurified Chinese gum rosin and the resol type phenol resin obtained in Production Example 3 were used in the same manner. A phenolic resin was produced. The metal content of the resin is 15 ppm (Al), 21 ppm (Ca), 10 ppm (Fe), tolerance of an aromatic hydrocarbon solvent (trade name: 0 Solvent H, manufactured by Nippon Oil Corporation). Was 3.0 g / g, the acid value was 16.9, the softening point was 141 ° C., and the weight average molecular weight was 38,000.

Comparative Example 2: (Production of rosin-modified phenolic resin from resol-type phenolic resin using raw rosin and volatile base catalyst)
In Example 1, a rosin-modified phenolic resin was produced in the same manner except that unpurified Chinese gum rosin was used instead of purified rosin. The metal content of the resin is 14 ppm (Al), 5 ppm (Ca), 9 ppm (Fe), tolerance of an aromatic hydrocarbon solvent (trade name: 0 Solvent H, manufactured by Nippon Oil Corporation). Was 3.3 g / g, the acid value was 17.1, the softening point was 141 ° C., and the weight average molecular weight was 40,000.

Comparative Example 3: (Production of rosin-modified phenolic resin using resol-type phenolic resin as raw material using purified rosin and basic metal catalyst)
In Example 1, a rosin-modified phenol resin was produced in the same manner except that the resol type phenol resin obtained in Production Example 3 was used instead of the resol type phenol resin obtained in Production Example 2. In addition, the metal content of the resin is 14 ppm (Ca), the tolerance of the aromatic hydrocarbon solvent (trade name: No. 0 Solvent H, manufactured by Shin Nippon Oil Co., Ltd.) is 3.0 g / g, and the acid value is 17.0, the softening point was 146 ° C., and the weight average molecular weight was 38,000.

(Preparation of varnish)
48 parts of the resin obtained in each example and comparative example, 10 parts of soybean oil, and 40 parts of AF Solvent No. 7 (manufactured by Shin Nippon Oil Co., Ltd., non-aromatic petroleum solvent) are mixed at 180 ° C. for 30 minutes. Dissolved. Next, after cooling to 80 ° C., 2 parts of aluminum chelate (trade name ALCH, manufactured by Kawaken Fine Chemical Co., Ltd.) was added and heated to 190 ° C. for 1 hour to obtain a gel varnish.

(Varnish stability test)
Viscosity: The gel varnish after preparation and after standing at room temperature for 3 months was measured at 25 ° C. using a cone and plate viscometer manufactured by Nippon Rheology Equipment Co., Ltd. The smaller the change in viscosity, the better. The results are shown in Table 1.

(Preparation of printing ink)
Using the gel varnishes of the examples and comparative examples, printing ink was prepared by kneading with a three roll mill at the following blending ratio.
Carbon black 18 parts by weight Gel varnish 65-73 parts by weight Nisseki AF Solvent No. 7 9-17 parts by weight Based on the above formulation, the incometer tack value at 30 ° C. and 400 rpm is 9.5 ± 0.5 at 25 ° C. The flow meter was adjusted as appropriate so that the flow value of the spread meter was 20.0 ± 1.0.

(Ink performance test)
Emulsification rate: 25 g of ink was emulsified to a saturated state using a lithotronic emulsification tester (manufactured by NOVOCONTROL). Thereafter, excess water in the emulsified ink was cut with a spatula on the copper plate, and the emulsification rate was measured with a Karl Fischer moisture meter (manufactured by Kyoto Electronics Industry Co., Ltd.). The smaller the numerical value, the better the emulsification rate, and the results are shown in Table 1.
Plate stain resistance: 0.4 ml of ink was applied to the entire roll of an RI tester (manufactured by Ishikawajima Industrial Machinery Co., Ltd.) and then developed on the PS plate. Then, water was supplied with the dampening water supply apparatus. After rotating at 60 rpm for 30 seconds, the degree of contamination of the non-image area of the PS plate was visually evaluated. The results are shown in Table 1. The results are shown in Table 1.

The printing inks (Examples 1 to 5) using the rosin-modified phenolic resin according to the present invention are more resistant than the inks (Comparative Examples 1 to 3) using a resin having a residual metal amount in the resin of more than 10 ppm. Plate stain resistance and stability over time can be improved.

Claims (7)

A rosin-modified phenol resin having a metal content of 10 ppm or less, obtained by reacting a purified rosin (a), a condensate (b) of phenols with formaldehyde and a polyol (c). At least one selected from the group consisting of purified rosins (a), condensates (b) of phenols and formaldehyde, polyols (c), polybasic acids (d), epoxy compounds (e) and polyfunctional acrylates (f) A rosin-modified phenol resin having a metal content of 10 ppm or less obtained by reacting seeds. The rosin-modified phenol resin according to claim 1 or 2, wherein the purified rosin (a) is a rosin purified using at least one method selected from the group consisting of distillation and extraction. The rosin-modified phenolic resin according to any one of claims 1 to 3, wherein the condensate (b) of phenols and formaldehyde is a condensate obtained in the presence of a volatile basic catalyst. The rosin-modified phenol resin according to any one of claims 1 to 4, wherein the polyol is a compound having at least three hydroxyl groups in one molecule. The rosin-modified phenolic resin according to any one of claims 1 to 5, having a weight average molecular weight of 10,000 to 400,000. A rosin-modified phenol resin for offset printing, comprising the rosin-modified phenol resin according to claim 1.