JP7487035B2 - Method for producing rosin-modified alkyd resin - Google Patents

Description

The present invention relates to a method for producing rosin-modified alkyd resin.

In recent years, various industries and sectors have been working to reduce the environmental impact, but the ultimate goal is the conservation of the global environment. The printing ink industry has also been working to reduce the environmental impact from various perspectives, and products that meet the purpose of such activities are given various certification marks. Such certification marks include the NL regulation mark, vegetable mark, GP mark, and Clione mark. In this context, the Japan Printing Ink Makers Association recently established a new Ink Green Mark (hereinafter referred to as IG Mark) system. The IG Mark is a system that uses the ratio of biomass-derived components among the various components that mainly make up the ink composition as an indicator, and ranks the environmental friendliness level of the ink composition into three levels depending on the level. In other words, this system is characterized by encouraging the replacement of raw materials derived from fossil resources with raw materials derived from biomass in order to reduce the environmental impact.

Recently, in various printing fields, a printing method has become popular in which the ink composition present on the surface of a printed material is instantly dried by irradiating the printed material with active energy rays such as ultraviolet rays or electron beams immediately after printing. The ink composition used in this printing method contains a photopolymerization initiator that generates radicals or cations when irradiated with active energy rays, and a monomer or oligomer that reacts with these radicals or cations to polymerize. When irradiated with active energy rays, the ink composition present on the surface of the printed material becomes a film-like cured product and is in a dry state. Among such ink compositions, products that are cured with ultraviolet rays are called UV inks, and various products have been proposed, particularly in the field of offset printing, where high-speed printing is performed (see, for example, Patent Document 1).

As with other ink compositions, there is a growing movement to reduce the environmental impact of UV inks, with some products being sold that can be dried with less UV radiation and others that can be dried with the light of low-power light-emitting diodes (LEDs). However, UV inks require large amounts of monomers and oligomers as ingredients, making it difficult to use a large amount of biomass-derived ingredients. For this reason, the IG Mark certification criteria do not include the ratio of biomass-derived ingredients, and instead environmental characteristics such as recyclability and energy-saving compatibility are currently used as indicators.

JP 2014-173070 A

In light of the above, increasing the ratio of biomass-derived components in UV inks is socially useful and of great significance. However, the monomers and oligomers used in UV inks and other active energy ray-curable offset printing ink compositions have poor compatibility with biomass-derived materials used in general offset printing ink compositions, making it difficult to simply apply conventional materials.

The present invention has been made in consideration of the above circumstances, and aims to provide a resin for an ink composition that can be used in the preparation of an active energy ray-curable ink composition and that can increase the proportion of biomass-derived components. Another aim of the present invention is to provide an ink composition for offset printing, in particular an active energy ray-curable offset printing ink composition, in which the proportion of biomass-derived components is increased by using such a resin.

The present inventors have conducted extensive research to solve the above problems, and as a result have found that, among rosin-modified alkyd resins which are condensation polymers of acid components including resin acids, fatty acids and polybasic acids, and polyhydric alcohols, those having a solubility parameter sp value of 9.0 to 11.0 (cal/cm ³ ) ^1/2 and an acid value of 1 to 50 mgKOH/g exhibit good compatibility with monomers and oligomers which are the raw materials for UV inks, and further, because resin acids and fatty acids are components derived from biomass, their use in UV inks can increase the proportion of biomass-derived components. The present invention was completed based on the above findings, and provides the following.

The present invention is a method for producing a rosin-modified alkyd resin, comprising: an ester exchange step of preparing a reaction intermediate by subjecting a vegetable oil and/or a fatty acid ester thereof to an ester exchange reaction with any of the following (1) to (3); and a condensation polymerization step of condensing and polymerizing the reaction intermediate in the presence of a polyhydric alcohol, wherein the vegetable oil and/or the fatty acid ester thereof is selected so that the obtained rosin-modified alkyd resin has a solubility parameter, sp, of 9.0 to 11.0 (cal/cm ³ ) ^1/2 as measured by a turbidity point measurement method and an oil length of 50 to 85:
(1) Resin acids and polybasic acids (2) Resin acid derivatives having multiple carboxyl groups (3) Resin acid derivatives having multiple carboxyl groups and polybasic acids

In the above invention , the vegetable oil is preferably coconut oil or palm kernel oil.

According to the present invention, a resin for an ink composition is provided that can be used to prepare an active energy ray-curable ink composition and can increase the ratio of biomass-derived components. Furthermore, according to the present invention, by using such a resin, an ink composition for offset printing, in particular an active energy ray-curable offset printing ink composition, in which the ratio of biomass-derived components is increased is provided.

Below, an embodiment of the method for producing a rosin-modified alkyd resin of the present invention, an embodiment of a rosin-modified alkyd resin, an embodiment of an ink composition for offset printing, and an embodiment of a method for producing a printed matter will be described. Note that the present invention is not limited to the following embodiments and examples, and can be practiced with appropriate modifications within the scope of the present invention.

<First embodiment of method for producing rosin-modified alkyd resin>
First, a first embodiment of the method for producing a rosin modified alkyd resin of the present invention will be described below. This embodiment is a method for producing a rosin modified alkyd resin comprising a step of reacting an acid component containing a resin acid, a fatty acid, and a polybasic acid with a polyhydric alcohol, and is characterized in that the fatty acid is selected so that the solubility parameter sp value of the obtained rosin modified alkyd resin as measured by a turbidity point measurement method is 9.0 to 11.0 (cal/cm ³ ) ^1/2 .

Resin acids refer to abietic acid and its isomers contained in rosins, as well as their derivatives. Rosins are non-volatile components of pine resin collected from plants of the Pinaceae family, and are mainly composed of abietic acid and its isomers. Examples of abietic acid and its isomers include abietic acid, neoabietic acid, palustric acid, pimaric acid, isopimaric acid, and dehydroabietic acid, all of which have a carboxyl group and can form esters with polyhydric alcohols described below. By introducing such resin acids into the rosin-modified alkyd resin of the present invention, it is possible to improve the affinity for pigments and increase the ratio of biomass-derived components in the resulting rosin-modified alkyd resin.

Although the above abietic acid and its isomers contain only one carboxyl group, multiple carboxyl groups can be introduced by modifying it. For example, abietic acid is a trans-diene compound, but when heated, it can be isomerized to a cis-diene compound. By subjecting the cis-diene compound thus obtained to a Diels-Alder reaction with a dienophile compound having multiple carboxyl groups, such as maleic acid or 1,2-cyclohexenedicarboxylic acid, multiple carboxyl groups can be introduced into the abietic acid skeleton. In addition, polymerized rosin is synthesized by polymerizing multiple molecules of abietic acid or its isomers, and such compounds also have multiple carboxyl groups. The above-mentioned derivatives of abietic acid and its isomers refer to such compounds.

Since rosins are mainly composed of resin acid, the synthesis can be carried out using rosins themselves instead of the resin acid. There are several types of rosins known, each differing in the manufacturing method and the subsequent chemical treatment, but any of these rosins may be used in the present invention. Examples of such rosins include gum rosin, wood rosin, tall rosin, disproportionated rosin, hydrogenated rosin, and polymerized rosin. Rosins may also be modified by the Diels-Alder reaction described above. From the viewpoint of storage stability, it is preferable to use rosins that do not have or have few conjugated double bonds chemically. Examples of such rosins include disproportionated rosin and hydrogenated rosin. Although rosins that have conjugated double bonds are somewhat inferior in terms of the storage stability of the synthesized resin, they can also be used without any problems.

Fatty acids are obtained by hydrolysis of natural fats and oils such as vegetable oils and animal oils, and because they have one carboxyl group, they can form esters with polyhydric alcohols, which will be described later. By introducing such fatty acids into the rosin-modified alkyd resin of the present invention, the ratio of biomass-derived components in the resulting rosin-modified alkyd resin can be increased. From this perspective, it is preferable to use an amount of fatty acid such that the oil length, which is the ratio (mass %) of the mass of the fatty acid portion to the mass of the entire resin, is about 30 to 85, and it is more preferable to use an amount of fatty acid such that the oil length is about 50 to 85.

As already mentioned, one of the features of the method for producing a rosin modified alkyd resin of the present invention is to select a fatty acid such that the sp value of the rosin modified alkyd resin to be prepared, as determined by the turbidity point measurement method, is 9.0 to 11.0 (cal/cm ³ ) ^1/2 . This value is relatively high for this type of resin, and the rosin modified alkyd resin to be prepared with such a high sp value can have good compatibility with monomers and oligomers that also have high sp values.

Examples of fatty acids include caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, oleic acid, linoleic acid, arachidic acid, and behenic acid. Fatty acids have a carboxyl group and can be said to be compounds with a relatively high sp value. Among these fatty acids, the lower the carbon number, the higher the sp value tends to be. From this viewpoint, in the present invention, fatty acids with 8 to 16 carbon atoms can be preferably used, and fatty acids with 8 to 14 carbon atoms can be more preferably used. By using one or more fatty acids with such high sp values in combination, the sp value of the rosin-modified alkyd resin to be prepared can also be increased. From this viewpoint, preferred examples include caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, and palmitic acid. All of these fatty acids have a Feders sp value of 9.18 or more. However, this does not mean that fatty acids having a lower sp value cannot be used, and fatty acids with a lower sp value can be used without problems if they are combined with fatty acids with a higher sp value. In any case, these can be appropriately combined so that the solubility parameter sp value of the prepared rosin-modified alkyd resin as measured by the turbidity point measurement method is 9.0 to 11.0 (cal/cm ³ ) ^1/2 . The fatty acid may be an unsaturated fatty acid or a saturated fatty acid, but from the viewpoint of avoiding coloring due to deterioration, fatty acids having one or less unsaturated bonds in the molecule are preferably used. For fatty acids having two or more unsaturated bonds such as oleic acid, linoleic acid, and eleostearic acid, it is preferable to use fatty acids in which the double bonds are epoxidized and eliminated by oxidation treatment. Such modified fatty acids can also be used as the fatty acid in the present invention. These fatty acids can be used alone or in combination of two or more.

As described above, the fewer the carbon number of the fatty acid, the more preferable it is, and from this viewpoint, it is preferable to use fatty acids from coconut oil or palm kernel oil. These fatty acids are rich in fatty acids having 12 to 14 carbon atoms, and are therefore preferably used to adjust the sp value of the rosin-modified alkyd resin to a high value. However, since it is sufficient that the sp value of the prepared rosin-modified alkyd resin is 9.0 to 11.0 (cal/cm ³ ) ^1/2 , fatty acids derived from other fats and oils may be used as long as such a range can be achieved.

A polybasic acid is a compound having multiple carboxyl groups, and is a component for polycondensation with a polyhydric alcohol (described later) to obtain a high molecular weight. As a compound having multiple carboxyl groups, any compound that has been used in the synthesis of alkyd resins can be used without limitation, and may have two or more carboxyl groups, or may be an acid anhydride thereof.

Examples of such compounds include phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, trimellitic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexenedicarboxylic acid, 1,4-cyclohexenedicarboxylic acid, hexahydrophthalic anhydride, 5-sodiosulfoisophthalic acid, fumaric acid, benzoic acid, tert-butylbenzoic acid, tetrahydrophthalic anhydride, maleic anhydride, succinic acid, fumaric acid, sebacic acid, azelaic acid, tetrabromophthalic anhydride, methylhimic anhydride, tetrachlorophthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, trimellitic anhydride, methylcyclohexenedicarboxylic anhydride, etc. These can be used alone or in combination of two or more.

The polyhydric alcohol forms an ester with the acid components, including the resin acid, fatty acid, and polybasic acid, as already explained, and increases the molecular weight of these components. As the polyhydric alcohol, any of those that have been used in the synthesis of alkyd resins up to now can be used without restriction, and examples of such polyhydric alcohols include compounds with two or more hydroxyl groups.

Such compounds include ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, 1,3-butanediol, neopentyl glycol, spiroglycol, dioxane glycol, adamantanediol, 3-methyl-1,5-pentanediol, methyloctanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 2-methylpropanediol 1,3, 3-methylpentanediol 1,5, hexamethylene glycol, Examples of the polyether polyol include ethylene oxide, octylene glycol, 9-nonanediol, 2,4-diethyl-1,5-pentanediol, ethylene oxide modified compounds of bifunctional phenols such as bisphenol A, propylene oxide modified compounds of bifunctional phenols such as bisphenol A, ethylene oxide and propylene oxide copolymer modified compounds of bisphenol A, copolymer polyether polyols of ethylene oxide and propylene oxide, polycarbonate diols, adamantane diols, polyether diols, polyester diols, polycaprolactone diols, etc. These can be used alone or in combination of two or more.

To adjust the molecular weight of the rosin-modified alkyd resin being prepared, a monobasic acid other than a fatty acid may be added as an acid component. Such monobasic acids include benzoic acid, acetic acid, propionic acid, and butyric acid.

The rosin-modified alkyd resin is prepared by reacting the acid components including the resin acid, fatty acid, and polybasic acid with polyhydric alcohol. The reaction procedure can be a method in which a small amount of a solvent such as xylene is added to a reaction vessel containing these raw materials while injecting an inert gas such as nitrogen gas, and the mixture is heated to perform azeotropic distillation with the condensation water while removing the water, thereby performing condensation polymerization. The reaction temperature can be about 170 to 250°C, and the reaction time can be about 5 to 25 hours, but is not particularly limited. The end of the reaction can be determined by monitoring the acid value of the reaction mixture as the reaction time elapses. In other words, the reaction can be completed when the decrease in the acid value of the reaction mixture accompanying the condensation polymerization stops. The condensation polymerization reaction can be performed in a shorter time by distilling the water generated by the condensation polymerization out of the system or by using a reaction catalyst. Examples of reaction catalysts include tetrabutyl zirconate, monobutyltin oxide (monobutyltin oxide), zirconium naphthate, tetrabutyl titanate, etc.

The weight-average molecular weight of the rosin-modified alkyd resin obtained by the condensation polymerization reaction is preferably about 1,000 to 70,000. Since the weight-average molecular weight of the rosin-modified alkyd resin is determined by the balance between the acid component and the polyhydric alcohol, it is desirable to carry out the initial synthesis on a small scale and then move on to a large scale synthesis after determining the reaction conditions and the types of raw materials.

It is necessary to select the type and amount of fatty acid as raw material so that the solubility parameter sp value of the rosin modified alkyd resin obtained by the condensation polymerization reaction as determined by turbidity point titration is 9.0 to 11.0 (cal/cm ³ ) ^1/2 . Therefore, as in the case of the weight average molecular weight described above, it is desirable to carry out the initial synthesis on a small scale and move to a large scale synthesis after determining the reaction conditions and the type of raw materials. The solubility parameter sp value of the rosin modified alkyd resin as determined by turbidity point titration is more preferably 9.3 to 10.0 (cal/cm ³ ) ^1/2 , and even more preferably 9.5 to 10.0 (cal/cm ³ ) ^1/2 .

The acid value of the rosin-modified alkyd resin obtained by the condensation polymerization reaction is 1 to 50 mgKOH. By having an acid value of 50 mgKOH or less, it is possible to suppress the occurrence of problems such as abnormal emulsification in an offset printing ink composition to which this rosin-modified alkyd resin is applied. This acid value is preferably 1 to 25 mgKOH, and more preferably 1 to 10 mgKOH. Note that since the acid value of the rosin-modified alkyd resin at the end of the reaction is determined by the balance between the amounts of the acid component and the polyhydric alcohol, it is desirable to carry out the initial synthesis on a small scale, and then move on to a large scale synthesis after determining the reaction conditions and the types of raw materials, as in the case of the weight average molecular weight described above.

Here, the calculation of the solubility parameter sp value by the turbidity point titration method will be described. This can be measured by turbidity point titration, which is a simple measurement method, and is a value calculated according to the following formula by K. W. SUH and J. M. CORBETT. For the calculation of the sp value by this method, J. Appl. Polym. Sci. 1968, 12, 2359 can be referred to.
Formula sp value = (V _ml ^1/2 . δH + V _mh ^1/2 . δD) / (V _ml ^1/2 + V _mh ^1/2 )

In the turbidity point titration, 0.5 g of a sample is dissolved in 10 mL of toluene, which is a good solvent, or 10 mL of trimethylolpropane triacrylate (TMPTA), to which n-hexane, which is a poor solvent with a low sp value, is added, and the titer H (mL) at the turbidity point is read. Similarly, when ethanol, which is a poor solvent with a high sp value, is added to the toluene solution, the titer D (mL) at the turbidity point is read, and these are applied to the following equation to calculate V _ml , V _mh , δH, and δD, which are then substituted into the above equation.

The molar volumes and sp values of the solvents used in the above turbidity point titration are as follows:
Molecular volume of good solvent φ0 Toluene: 106.28 mL/mol
TMPTA: 279.55 mL/mol
Molecular volume of low sp value poor solvent φl n-hexane: 131.61 mL/mol
Molecular volume of high sp value poor solvent φh Ethanol: 58.39 mL / mol
SP value of each solvent: Toluene: 9.14, TMPTA: 9.88
n-Hexane: 7.28, Ethanol: 12.58

_Vml = (φ0 · φl) / {(1-VH) · φl + VH · φ0}
_Vmh = (φ0 · φh) / {(1-VD) · φh + VD · φ0}
VH=H/(M+H)
VD = D / (M + D)
δH=(δ0·M)/(M+H)+(δl·H)/(M+H)
δD = (δ0 · M) / (M + D) + (δl · D) / (M + D)

δ0: sp value of good solvent δl: sp value of low sp value poor solvent δh: sp value of high sp value poor solvent H: titration amount (mL) of low sp value poor solvent
D: Titration amount (mL) of high sp value poor solvent
M: amount of good solvent (mL)
VH: Volume fraction of low sp value poor solvent titration (%)
VD: Volume fraction of high sp value poor solvent titration (%)

<Second embodiment of the method for producing rosin-modified alkyd resin>
Next, a second embodiment of the method for producing a rosin-modified alkyd resin of the present invention will be described. This embodiment is a method for producing a rosin-modified alkyd resin comprising an ester exchange step of preparing a reaction intermediate by ester exchange reaction between a vegetable oil and/or a fatty acid ester thereof and a polyhydric alcohol, and a condensation polymerization step of condensing and polymerizing the reaction intermediate in the presence of any one of the following (1) to (3), characterized in that the vegetable oil is selected so that the solubility parameter sp value of the obtained rosin-modified alkyd resin as measured by a turbidity point measurement method is 9.0 to 11.0 (cal/cm ³ ) ^1/2 . In describing this embodiment, explanations of parts that overlap with the explanation of the first embodiment already described will be omitted as appropriate.
(1) Resin acids and polybasic acids (2) Resin acid derivatives having multiple carboxyl groups (3) Resin acid derivatives having multiple carboxyl groups and polybasic acids

In this embodiment, two steps are involved: an ester exchange step and a subsequent condensation polymerization step. First, the ester exchange step will be explained.

[Transesterification process]
The transesterification process is a process of preparing a reaction intermediate by transesterifying vegetable oil and/or its fatty acid ester with a polyhydric alcohol. In the first embodiment described above, an acid component including a resin acid, a fatty acid, and a polybasic acid is polycondensed with a polyhydric alcohol, but in this embodiment, instead of the fatty acid and polyhydric alcohol among these raw materials, a reaction intermediate obtained by transesterifying vegetable oil and/or a fatty acid ester of vegetable oil with a polyhydric alcohol is used, which is a major difference. The method of transesterifying vegetable oil and/or its fatty acid ester with a polyhydric alcohol and then performing condensation polymerization in this way is often used in the synthesis of alkyd resins, and the transesterification reaction performed here is called alcoholysis.

Vegetable oils are esters of fatty acids and glycerin, and in the manufacturing method of the present invention, they are not only a source of fatty acids and polyhydric alcohols (glycerin), but the entire amount used is counted as a biomass-derived component. Examples of vegetable oils include hemp seed oil, linseed oil, perilla oil, oiticica oil, olive oil, cacao oil, kapok oil, kaya oil, mustard oil, apricot kernel oil, tung oil, kukui oil, walnut oil, poppy seed oil, sesame oil, safflower oil, radish seed oil, soybean oil, tsubaki oil, camellia oil, corn oil, rapeseed oil, niger oil, rice bran oil, palm oil, castor oil, sunflower oil, grape seed oil, almond oil, pine seed oil, cottonseed oil, coconut oil, peanut oil, and dehydrated castor oil. Epoxidized vegetable oils in which double bonds have been eliminated by oxidation treatment can also be used as vegetable oils in the present invention. Examples of such epoxidized vegetable oils include epoxidized soybean oil (ESO), epoxidized linseed oil (ELO), etc. These vegetable oils can be used alone or in combination of two or more.

The vegetable oil and/or vegetable oil fatty acid ester must be selected so that the rosin-modified alkyd resin to be synthesized has a relatively high solubility parameter sp value of 9.0 to 11.0 (cal/cm ³ ) ^1/2 as measured by the turbidity point measurement method. As already explained, from this viewpoint, it is preferable to select a vegetable oil or vegetable oil fatty acid ester having a fatty acid with a small number of carbon atoms, and it is particularly preferable to use coconut oil or palm kernel oil that is rich in fatty acids having 12 to 14 carbon atoms. The fatty acid contained in the vegetable oil may be an unsaturated fatty acid or a saturated fatty acid, but from the viewpoint of avoiding coloring due to deterioration, vegetable oils containing fatty acids having one or less unsaturated bonds in the molecule are preferably used. The solubility parameter sp value of the rosin-modified alkyd resin to be synthesized as measured by the turbidity point measurement method is more preferably 9.3 to 10.0 (cal/cm ³ ) ^1/2 , and even more preferably 9.5 to 10.0 (cal/cm ³ ) ^1/2 .

Polyhydric alcohols react with polybasic acids to contribute to high molecular weight through condensation polymerization, and also improve solubility and affinity with pigments by introducing fatty chains through ester exchange reactions with vegetable oils. Examples of polyhydric alcohols include compounds with two or more hydroxyl groups, such as ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, 1,3-butanediol, neopentyl glycol, spiro glycol, dioxane glycol, adamantanediol, 3-methyl-1,5-pentanediol, methyloctanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 2-methylpropanediol 1,3, 3-methylpentanediol 1,5, hexamethylene glycol, octylene glycol, 9-nonanediol, 2,4-diethyl-1,5-pentanediol, etc. Examples of the polyhydric alcohol include ethylene oxide modified compounds of bifunctional phenols such as bisphenol A, propylene oxide modified compounds of bifunctional phenols such as bisphenol A, ethylene oxide and propylene oxide copolymer modified compounds of bisphenol A, copolymerized polyether polyols of ethylene oxide and propylene oxide, polycarbonate diols, adamantane diols, polyether diols, polyester diols, polycaprolactone diols, glycerin, trimethylolethane, trimethylolpropane, sorbitol, pentaerythritol, ditrimethylolpropane, dipentaerythritol, tripentaerythritol, adamantane triol, and polycaprolactone triol. These polyhydric alcohols can be used alone or in combination of two or more.

The above vegetable oil and polyhydric alcohol are reacted to cause an ester exchange reaction, producing a reaction intermediate. The reaction procedure involves heating the reaction vessel containing these raw materials while allowing an inert gas such as nitrogen gas to flow in. The reaction temperature can be about 170 to 250°C, and the reaction time can be about 1 to 2 hours, but is not particularly limited.

The reaction mixture containing the reaction intermediate prepared through the transesterification process is subjected to a condensation polymerization process.

[Condensation polymerization process]
The condensation polymerization step is a step of condensation polymerization of the reaction intermediate obtained in the above transesterification step in the presence of (1) a resin acid and a polybasic acid, (2) a resin acid derivative having multiple carboxyl groups, or (3) a resin acid derivative having multiple carboxyl groups and a polybasic acid. All of the above (1) to (3) contain a compound containing multiple carboxyl groups in one molecule, i.e., a polycarboxylic acid compound, and in this step, this compound is condensed with the above reaction intermediate containing a compound having one or more hydroxyl groups in one molecule. In addition, since the above (1) to (3) always contain a resin acid or a resin acid derivative, the resin acid is introduced into the polymer obtained as a result of the condensation polymerization. This synthesizes a rosin-modified alkyd resin.

The resin acid, the resin acid derivative having multiple carboxyl groups, and the polybasic acid are as described in the first embodiment of the method for producing a rosin-modified alkyd resin, and therefore will not be described here. Similarly, a monobasic acid other than a fatty acid may be added as an acid component to adjust the molecular weight of the rosin-modified alkyd resin to be prepared.

The procedure for the polycondensation reaction is as follows: add any one of the above (1) to (3) into the reaction mixture containing the intermediate reaction product, add a small amount of a solvent such as xylene while injecting an inert gas such as nitrogen gas into the reaction vessel, heat the mixture, and remove the water by azeotropy with the condensation water. The reaction temperature can be about 170 to 250°C, and the reaction time can be about 5 to 25 hours, but is not limited thereto. The end of the reaction can be determined by monitoring the acid value of the reaction mixture as the reaction time elapses. In other words, the reaction can be completed when the decrease in the acid value of the reaction mixture accompanying the polycondensation stops. The polycondensation reaction can be performed in a shorter time by distilling the water generated by the polycondensation out of the system or by using a reaction catalyst. Examples of the reaction catalyst include tetrabutyl zirconate, monobutyltin oxide, zirconium naphthate, and tetrabutyl titanate.

The weight-average molecular weight of the rosin-modified alkyd resin obtained by the condensation polymerization reaction is preferably about 1,000 to 70,000. The weight-average molecular weight of the rosin-modified alkyd resin is determined by the balance of the vegetable oil, resin acid and/or its derivatives, polybasic acid, and polyhydric alcohol, so it is desirable to carry out the initial synthesis on a small scale and then move on to a large-scale synthesis after determining the reaction conditions and types of raw materials.

As already mentioned, it is necessary to select the type and amount of vegetable oil and its fatty acid ester as raw materials in the above transesterification step so that the solubility parameter sp value of the rosin-modified alkyd resin obtained by the condensation polymerization reaction as determined by turbidity point titration is 9.0 to 11.0 (cal/cm ³ ) ^1/2 . Therefore, as in the case of the weight-average molecular weight described above, it is desirable to carry out the initial synthesis on a small scale and move on to a large-scale synthesis after determining the reaction conditions and the type of raw materials. The solubility parameter sp value of the rosin-modified alkyd resin as determined by turbidity point titration is more preferably 9.3 to 10.0 (cal/cm ³ ) ^1/2 , and even more preferably 9.5 to 10.0 (cal/cm ³ ) ^1/2 .

The acid value of the rosin-modified alkyd resin obtained by the condensation polymerization reaction is 1 to 50 mgKOH. By having an acid value of 50 mgKOH or less, it is possible to suppress the occurrence of problems such as abnormal emulsification in an offset printing ink composition to which this rosin-modified alkyd resin is applied. This acid value is preferably 1 to 25 mgKOH, and more preferably 1 to 10 mgKOH. Note that since the acid value of the rosin-modified alkyd resin at the end of the reaction is determined by the balance of the amounts of the vegetable oil, resin acid and/or its derivatives, polybasic acid, and polyhydric alcohol, it is desirable to carry out the initial synthesis on a small scale, and then move on to a large scale synthesis after determining the reaction conditions and the types of raw materials, as in the case of the weight average molecular weight described above.

<Third embodiment of the method for producing rosin-modified alkyd resin>
Next, a third embodiment of the method for producing a rosin-modified alkyd resin of the present invention will be described. This embodiment is a method for producing a rosin-modified alkyd resin comprising an ester exchange step of preparing a reaction intermediate by ester exchange reaction between a vegetable oil and/or a fatty acid ester thereof and any one of the following (1) to (3), and a condensation polymerization step of condensing and polymerizing the reaction intermediate in the presence of a polyhydric alcohol, characterized in that the vegetable oil is selected so that the solubility parameter sp value of the obtained rosin-modified alkyd resin as measured by a turbidity point measurement method is 9.0 to 11.0 (cal/cm ³ ) ^1/2 . In describing this embodiment, explanations of parts that overlap with the explanations of the first and second embodiments already described will be omitted as appropriate.
(1) Resin acids and polybasic acids (2) Resin acid derivatives having multiple carboxyl groups (3) Resin acid derivatives having multiple carboxyl groups and polybasic acids

In this embodiment, two steps are involved: an ester exchange step and a subsequent condensation polymerization step. First, the ester exchange step will be explained.

[Transesterification process]
The transesterification process is a process of preparing a reaction intermediate by transesterifying a vegetable oil and/or its fatty acid ester with either (1) a resin acid and a polybasic acid, (2) a resin acid derivative having a plurality of carboxyl groups, or (3) a resin acid derivative having a plurality of carboxyl groups and a polybasic acid. In the second embodiment described above, the vegetable oil and/or its fatty acid ester is transesterified with a polyhydric alcohol and then condensed. In this embodiment, however, the major difference is that the vegetable oil and/or its fatty acid ester is transesterified with the polycarboxylic acid compound (1) to (3) and then condensed. In this manner, the method of transesterifying a vegetable oil and/or its fatty acid ester with a polycarboxylic acid compound and then condensing is often used in the synthesis of alkyd resins, and the transesterification reaction carried out here is called acidolysis.

The vegetable oil and/or its fatty acid ester, resin acid, resin acid derivatives, and polybasic acid have already been explained, so their explanation will be omitted here. Similarly, in order to adjust the molecular weight of the rosin-modified alkyd resin to be prepared, a monobasic acid may be added in addition to these acid components.

In this process, a transesterification reaction occurs by reacting a vegetable oil and/or its fatty acid ester with any of the above (1) to (3), and a reaction intermediate is prepared. The reaction procedure includes heating a reaction vessel containing these raw materials while allowing an inert gas such as nitrogen gas to flow in. The reaction temperature can be about 170 to 250°C, and the reaction time can be about 1 to 2 hours, but is not particularly limited.

The reaction mixture containing the reaction intermediate prepared via the transesterification reaction is subjected to a condensation polymerization process.

[Condensation polymerization process]
The condensation polymerization step is a step of condensing the reaction intermediate obtained in the transesterification step in the presence of a polyhydric alcohol. The polyhydric alcohol is a compound having multiple hydroxyl groups in one molecule, and in this step, this compound is condensed with the reaction intermediate containing a compound having one or more carboxyl groups in one molecule. Since the compound contained in the reaction intermediate contains a resin acid or a resin acid derivative, the resin acid is introduced into the polymer obtained as a result of the condensation polymerization. This results in a rosin-modified alkyd resin.

The polyhydric alcohol is as described above in the second embodiment of the method for producing a rosin-modified alkyd resin, so a detailed explanation is omitted here.

The procedure for the polycondensation reaction is as follows: a polyhydric alcohol is added to the reaction mixture containing the intermediate product, and a small amount of a solvent such as xylene is added while an inert gas such as nitrogen gas is flowed into the reaction vessel, followed by heating to remove water by azeotropy with the condensation water. The reaction temperature can be about 170 to 250°C, and the reaction time can be about 5 to 25 hours, but is not limited thereto. The end of the reaction can be determined by monitoring the acid value of the reaction mixture as the reaction time elapses. In other words, the reaction can be completed when the decrease in the acid value of the reaction mixture accompanying the polycondensation stops. The polycondensation reaction can be performed in a shorter time by distilling the water generated by the polycondensation out of the system or by using a reaction catalyst. Examples of the reaction catalyst include tetrabutyl zirconate, monobutyltin oxide (monobutyltin oxide), zirconium naphthate, and tetrabutyl titanate.

It is necessary to select the type and amount of vegetable oil and its fatty acid ester as raw materials in the above transesterification step so that the rosin-modified alkyd resin obtained by the condensation polymerization reaction has a solubility parameter sp value by turbidity point titration of 9.0 to 11.0 (cal/cm ³ ) ^1/2 . For this reason, it is desirable to carry out the initial synthesis on a small scale and move on to a large-scale synthesis after determining the reaction conditions and the types of raw materials. The solubility parameter sp value by turbidity point titration of the rosin-modified alkyd resin is more preferably 9.3 to 10.0 (cal/cm ³ ) ^1/2 , and even more preferably 9.5 to 10.0 (cal/cm ³ ) ^1/2 .

The acid value of the rosin-modified alkyd resin obtained by the condensation polymerization reaction is 1 to 50 mgKOH. By having an acid value of 50 mgKOH or less, it is possible to suppress the occurrence of problems such as abnormal emulsification in an offset printing ink composition to which this rosin-modified alkyd resin is applied. This acid value is preferably 1 to 25 mgKOH, and more preferably 1 to 10 mgKOH. Note that the acid value of the rosin-modified alkyd resin at the end of the reaction is determined by the balance of the amounts of vegetable oil, resin acid and/or its derivative, polybasic acid, and polyhydric alcohol, so similar to the sp value described above, it is desirable to carry out the initial synthesis on a small scale and move on to a large-scale synthesis after determining the reaction conditions and the types of raw materials.

<Rosin-modified alkyd resin>
Next, one embodiment of the rosin modified alkyd resin of the present invention will be described. The rosin modified alkyd resin of the present invention is prepared by the above-mentioned method for producing a rosin modified alkyd resin, and is one aspect of the present invention. The rosin modified alkyd resin of the present invention is a condensation polymer of an acid component including a resin acid, a fatty acid, and a polybasic acid, and a polyhydric alcohol, and is characterized in that the solubility parameter sp value measured by a turbidity point titration method is 9.0 to 11.0 (cal/cm ³ ) ^1/2 and the acid value is 1 to 50 mgKOH/g. In the following description, explanations of parts that overlap with the explanations of each embodiment of the method for producing a rosin modified alkyd resin already described will be omitted as appropriate.

The rosin-modified alkyd resin of the present invention can be preferably used in the preparation of an ink composition for offset printing, and is particularly compatible with the monomers and oligomers used in the preparation of active energy curable ink compositions, and is therefore preferably used in the preparation of active energy ray curable ink compositions for offset printing. The rosin-modified alkyd resin of the present invention contains a large amount of raw materials derived from biomass, and therefore the content of biomass-derived components in the ink composition containing this can be increased. In addition, the rosin-modified alkyd resin of the present invention contains a resin acid skeleton in its polymer chain or side chain, and therefore has excellent affinity for pigments, resulting in good pigment dispersibility and good gloss of the printed ink composition.

The rosin-modified alkyd resin of the present invention is a condensation polymer of an acid component including a resin acid, a fatty acid, and a polybasic acid, and a polyhydric alcohol. Each of these components has been described above. The fatty acid and the polyhydric alcohol may be added separately to the reaction mixture and reacted, or a vegetable oil, which is an ester of a fatty acid and glycerin, may be added to the reaction mixture and transesterified.

The solubility parameter sp value of the rosin modified alkyd resin of the present invention, as determined by turbidity point titration, is 9.0 to 11.0 (cal/cm ³ ) ^1/2 . Active energy ray-curable ink compositions contain monomers and oligomers as components, and these components have relatively high sp values. Therefore, the rosin modified alkyd resin of the present invention has a high sp value of 9.0 to 11.0 (cal/cm ³ ) ^1/2 for this type of material. As a result, the rosin modified alkyd resin of the present invention has high compatibility with monomers and oligomers, and can be preferably used not only in normal offset printing ink compositions, but also in active energy ray-curable offset printing ink compositions. The solubility parameter sp value of the rosin modified alkyd resin, as determined by turbidity point titration, is more preferably 9.3 to 10.0 (cal/cm ³ ) ^1/2 , and even more preferably 9.5 to 10.0 (cal/cm ³ ) ^1/2 .

In order to provide a high sp value as described above, the number of carbon atoms contained in the fatty acid constituting the rosin-modified alkyd resin is preferably small, and the number of carbon atoms contained in the fatty acid is preferably 8 to 16, and more preferably 8 to 14. Since such short-chain-length fatty acids are abundantly contained in coconut oil and palm kernel oil, the fatty acid constituting the rosin-modified alkyd resin of the present invention is preferably a fatty acid of coconut oil or palm kernel oil. In addition, from the viewpoint of increasing the ratio of biomass-derived components, the oil length, which is the ratio (mass %) of the mass of the fatty acid portion to the mass of the entire rosin-modified alkyd resin, is preferably 30 to 85, and more preferably 50 to 85.

The acid value of the rosin-modified alkyd resin of the present invention is 1 to 50 mgKOH/g. By having an acid value of 50 mgKOH or less, it is possible to suppress the occurrence of problems such as abnormal emulsification in an offset printing ink composition to which this rosin-modified alkyd resin is applied. This acid value is preferably 1 to 25 mgKOH, and more preferably 1 to 10 mgKOH.

The weight-average molecular weight of the rosin-modified alkyd resin of the present invention is preferably 1,000 to 70,000. A weight-average molecular weight of 1,000 or more is preferable because it provides excellent pigment dispersibility and imparts good viscoelasticity to the ink composition, and a weight-average molecular weight of 70,000 or less is preferable because it provides good solubility and excellent handling.

<Ink composition for offset printing>
The present invention also includes an ink composition for offset printing that contains the above-mentioned rosin-modified alkyd resin. As already explained, the rosin-modified alkyd resin of the present invention has a high ratio of components derived from biomass as a raw material, and the ratio of components derived from biomass in an ink composition for offset printing that contains the rosin-modified alkyd resin can be increased. Therefore, the ink composition for offset printing has a reduced environmental load and is suitable for receiving various environmental certifications, such as the IG mark certification.

As already explained, the rosin-modified alkyd resin of the present invention has excellent compatibility with the monomers and oligomers contained in the active energy ray-curable ink composition, and can therefore be preferably used as a component of the active energy ray-curable ink composition for offset printing. Such an active energy ray-curable ink composition for offset printing is also one aspect of the present invention.

When the rosin-modified alkyd resin of the present invention is used as a component of an ink composition for offset printing, it may be dissolved in an oil component such as vegetable oil or mineral oil to form a varnish. When the rosin-modified alkyd resin of the present invention is used as a component of an ink composition for offset printing that is curable with active energy rays, it may be dissolved in a low-viscosity monomer such as trimethylolpropane triacrylate (TMPTA), ditrimethylolpropane tetraacrylate, etc. to form a varnish.

<Method of manufacturing printed matter>
The present invention also includes a method for producing a printed matter, which is characterized by including a step of performing printing using the above-mentioned ink composition for offset printing of the present invention. As already mentioned, the ink composition for offset printing of the present invention is characterized by having a high ratio of biomass-derived components and having a smaller environmental impact than conventional products. By using such an ink composition for offset printing, printing with a smaller environmental impact can be performed, and a printed matter with a smaller environmental impact can be obtained.

The present invention will be explained in more detail below by showing examples, but the present invention is not limited to the following examples. In the following description, "parts" means parts by mass and "%" means % by mass.

[Example 1]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil and 36 parts of pentaerythritol were mixed and held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, and 160 parts of rosin, 50 parts of isophthalic acid, and further reflux xylene were added, gradually heated to 250°C, and held for 6 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 1. The acid value of the resin of Example 1 was 13 mgKOH/g, the sp value by turbidity point titration method was 9.74, and the weight average molecular weight (Mw) measured by GPC was 7,000.

[Example 2]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil and 36 parts of pentaerythritol were mixed and held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, and 160 parts of dehydroabietic acid, 50 parts of isophthalic acid, and further reflux xylene were added, gradually heated to 250°C, and held for 6 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 2. The acid value of the resin of Example 2 was 13 mgKOH/g, the sp value by turbidity point titration method was 9.70, and the weight average molecular weight (Mw) measured by GPC was 7,000.

[Example 3]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil and 50 parts of pentaerythritol were mixed and held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, and 160 parts of polymerized rosin, 50 parts of isophthalic acid, and further reflux xylene were added, gradually heated to 250°C, and held for 6 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 3. The acid value of the resin of Example 3 was 12 mgKOH/g, the sp value measured by the turbidity point titration method was 9.73, and the weight average molecular weight (Mw) measured by GPC was 14,000.

[Example 4]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil, 20 parts of pentaerythritol, and 16 parts of glycerin were mixed and held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, and 160 parts of rosin, 50 parts of isophthalic acid, and further reflux xylene were added, gradually heated to 250°C, and held for 6 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 4. The acid value of the resin of Example 4 was 12 mgKOH/g, the sp value by turbidity point titration method was 9.74, and the weight average molecular weight (Mw) measured by GPC was 9,000.

[Example 5]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil and 36 parts of pentaerythritol were mixed and held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, and 160 parts of rosin, 50 parts of fumaric acid, and further reflux xylene were added, gradually heated to 250°C, and held for 6 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 5. The acid value of the resin of Example 5 was 10 mgKOH/g, the sp value by turbidity point titration method was 9.73, and the weight average molecular weight (Mw) measured by GPC was 8,000.

[Example 6]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil and 36 parts of pentaerythritol were mixed and held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, and 160 parts of rosin, 50 parts of 1,2-cyclohexenedicarboxylic acid, and further xylene for reflux were added, gradually heated to 250°C, and held for 6 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 6. The acid value of the resin of Example 6 was 11 mgKOH/g, the sp value measured by the turbidity point titration method was 9.74, and the weight average molecular weight (Mw) measured by GPC was 8,000.

[Example 7]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil and 36 parts of pentaerythritol were blended, and the mixture was held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, and 160 parts of rosin, 50 parts of 1,2-cyclohexenedicarboxylic acid, and further xylene for reflux were added, and the mixture was gradually heated to 250°C. The mixture was held for 6 hours to carry out a condensation polymerization reaction while dehydrating, and then 10 parts of benzoic acid was added and the condensation polymerization reaction was carried out at 250°C for 1 hour. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 7. The acid value of the resin of Example 7 was 11 mgKOH/g, the sp value measured by the turbidity point titration method was 9.73, and the weight average molecular weight (Mw) measured by GPC was 6,000.

[Example 8]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil and 36 parts of pentaerythritol were blended, and the mixture was held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, and 160 parts of rosin, 50 parts of 1,2-cyclohexenedicarboxylic acid, and further xylene for reflux were added, and the mixture was gradually heated to 250°C. The mixture was held for 6 hours to carry out a condensation polymerization reaction while dehydrating, and then 10 parts of benzoic acid was added and the condensation polymerization reaction was carried out at 250°C for 1 hour. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 8. The acid value of the resin of Example 8 was 11 mgKOH/g, the sp value measured by the turbidity point titration method was 9.63, and the weight average molecular weight (Mw) measured by GPC was 8,000.

[Example 9]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil and 36 parts of pentaerythritol were blended and held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, and 160 parts of rosin, 50 parts of isophthalic acid, 10 parts of 1,2-cyclohexenedicarboxylic acid, and further xylene for reflux were added, gradually heated to 250°C, and held for 12 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 9. The acid value of the resin of Example 9 was 6 mgKOH/g, the sp value measured by the turbidity point titration method was 9.73, and the weight average molecular weight (Mw) measured by GPC was 19,000.

[Example 10]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil and 36 parts of pentaerythritol were blended and held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, and 160 parts of rosin, 50 parts of fumaric acid, 10 parts of 1,2-cyclohexenedicarboxylic acid, and further xylene for reflux were added, gradually heated to 250°C, and held for 12 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 10. The acid value of the resin of Example 10 was 5 mgKOH/g, the sp value measured by the turbidity point titration method was 9.74, and the weight average molecular weight (Mw) measured by GPC was 21,000.

[Example 11]
800 parts of coconut oil was mixed into a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, and the temperature was raised to 150°C. Then, 160 parts of rosin, 50 parts of 1,2-cyclohexenedicarboxylic acid, and further xylene for reflux were added, and the mixture was gradually heated to 250°C and held for 12 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 11. The acid value of the resin of Example 11 was 12 mgKOH/g, the sp value measured by the turbidity point titration method was 9.74, and the weight average molecular weight (Mw) measured by GPC was 9,000.

[Example 12]
800 parts of soybean oil was mixed into a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, and the temperature was raised to 150°C. Then, 160 parts of rosin, 50 parts of 1,2-cyclohexene dicarboxylic acid, and further xylene for reflux were added, and the mixture was gradually heated to 250°C and held for 12 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 12. The acid value of the resin of Example 12 was 10 mgKOH/g, the sp value measured by the turbidity point titration method was 9.45, and the weight average molecular weight (Mw) measured by GPC was 8,000.

[Example 13]
800 parts of coconut oil was mixed into a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, and the temperature was raised to 150°C. Then, 160 parts of disproportionated rosin, 50 parts of 1,2-cyclohexenedicarboxylic acid, and further xylene for reflux were added, and the mixture was gradually heated to 250°C and held for 12 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 13. The acid value of the resin of Example 13 was 12 mgKOH/g, the sp value measured by the turbidity point titration method was 9.76, and the weight average molecular weight (Mw) measured by GPC was 8,000.

[Example 14]
800 parts of coconut oil was mixed into a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, and the temperature was raised to 150°C. Then, 160 parts of rosin, 50 parts of fumaric acid, and further xylene for reflux were added, and the mixture was gradually heated to 250°C and held for 12 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 14. The acid value of the resin of Example 14 was 10 mgKOH/g, the sp value measured by the turbidity point titration method was 9.74, and the weight average molecular weight (Mw) measured by GPC was 9,000.

[Example 15]
800 parts of coconut oil was mixed into a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, and the temperature was raised to 150°C. Then, 160 parts of rosin, 50 parts of fumaric acid, and further xylene for reflux were added, and the mixture was gradually heated to 250°C. The mixture was maintained for 12 hours to carry out a condensation polymerization reaction while dehydrating, and then 10 parts of benzoic acid was added and the condensation polymerization reaction was carried out at 250°C for 1 hour. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 15. The acid value of the resin of Example 15 was 11 mgKOH/g, the sp value measured by the turbidity point titration method was 9.73, and the weight average molecular weight (Mw) measured by GPC was 8,000.

[Example 16]
800 parts of soybean oil was mixed into a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, and the temperature was raised to 150°C. Then, 160 parts of rosin, 50 parts of fumaric acid, and further xylene for reflux were added, and the mixture was gradually heated to 250°C. The mixture was held for 12 hours to carry out a condensation polymerization reaction while dehydrating, and then 10 parts of benzoic acid was added and the condensation polymerization reaction was carried out at 250°C for 1 hour. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Example 16. The acid value of the resin of Example 16 was 11 mgKOH/g, the sp value measured by the turbidity point titration method was 9.62, and the weight average molecular weight (Mw) measured by GPC was 7,000.

[Comparative Example 1]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil and 36 parts of pentaerythritol were mixed and held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, 160 parts of rosin and xylene for reflux were added, and the mixture was gradually heated to 250°C and held for 12 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining the resin of Comparative Example 1. The acid value of the resin of Comparative Example 1 was 21 mgKOH/g, the sp value measured by the turbidity point titration method was 8.84, and the weight average molecular weight (Mw) measured by GPC was 5,000.

[Comparative Example 2]
In a reaction kettle equipped with a stirrer, reflux condenser, and thermometer, 800 parts of soybean oil and 36 parts of pentaerythritol were blended and held at 250 ° C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150 ° C, 160 parts of rosin and xylene for reflux were added, gradually heated to 250 ° C, and held for 12 hours to carry out a condensation polymerization reaction while dehydrating. In order to further remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining a resin of Comparative Example 2. The acid value of the resin of Comparative Example 2 was 18 mg KOH / g, the sp value by turbidity point titration method was 8.89, and the weight average molecular weight (Mw) measured by GPC was 7,000.

[Comparative Example 3]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of coconut oil, 160 parts of rosin, 36 parts of pentaerythritol, and further xylene for reflux were added, gradually heated to 250°C, and held for 12 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining a resin of Comparative Example 3. The acid value of the resin of Comparative Example 3 was 17 mgKOH/g, the sp value measured by the turbidity point titration method was 8.91, and the weight average molecular weight (Mw) measured by GPC was 8,000.

[Comparative Example 4]
In a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, 800 parts of soybean oil, 160 parts of rosin, 36 parts of pentaerythritol, and further xylene for reflux were added, gradually heated to 250°C, and held for 12 hours to carry out a condensation polymerization reaction while dehydrating. In order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining a resin of Comparative Example 4. The acid value of the resin of Comparative Example 4 was 18 mgKOH/g, the sp value measured by the turbidity point titration method was 8.85, and the weight average molecular weight (Mw) measured by GPC was 8,000.

[Compatibility test with monomers]
The resins of Examples 1 to 16 and Comparative Examples 1 to 4 were tested for compatibility with various monomers used in active energy ray-curable ink compositions. The test was performed by mixing and stirring 80 parts of resin, 19 parts of monomer, and 1 part of butylhydroxytoluene (BHT) at a temperature of 80°C, then cooling to 25°C and visually observing the dissolved state. Each resin was evaluated according to the following criteria, and the results are shown in Table 1. The unit of sp value shown in Table 1 is (cal/ ^cm3 ) ^1/2 .
○: Completely dissolved, the solution is clear. △: The solution is slightly cloudy. ×: The solution is cloudy, solids are precipitated, or the solution does not dissolve.

The monomers shown in Table 1 are as follows: Soybean oil, which is an oil component typically used in ink compositions for offset printing, and AF Solvent No. 7 (manufactured by JX Nippon Oil & Gas Corporation) were also included in the test.
DPHA: Dipentaerythritol hexaacrylate TMPTA: Trimethylolpropane triacrylate DI-TMPTA: Ditrimethylolpropane tetraacrylate 3EO-TMPTA: Ethylene oxide 3 moles added TMPTA
6EO-TMPTA: TMPTA with 6 moles of ethylene oxide added
NPGDA: neopentyl glycol diacrylate TPGDA: tripropylene glycol diacrylate 3PO-TMPTA: propylene oxide 3 moles added TMPTA
2PO-NPGDA: 2 moles of propylene oxide added to NPGDA
AF-7: AF Solvent No. 7

As can be seen from Table 1, the rosin-modified alkyd resin of the present invention, which has an sp value of 9.0 to 11.0, exhibits good compatibility with various monomers used in active energy ray-curable ink compositions.

[Preparation of Varnish]
For each of the resins of Examples 1 to 16, 80 parts of the resin, 19 parts of DI-TMPTA, and 1 part of BHT were charged into a reaction kettle equipped with a cooling tube, and heated and stirred at 100°C for 1 hour to prepare varnishes 1 to 16, respectively. All varnishes were transparent and had good compatibility. The viscosity of each varnish was generally in the range of 1.9 to 5.4 Pa·s. Note that the resins of Comparative Examples 1 to 4 had poor compatibility, and varnishes could not be prepared.

[Preparation of active energy ray-curable ink composition for offset printing]
Inks 1 to 16 were prepared using each of the varnishes 1 to 16 prepared by the above procedure. The preparation procedure was as follows: 70 parts of varnish, 15 parts of carbon black (product name #60, manufactured by Mitsubishi Chemical Corporation), 7 parts of Irgacure 907 (manufactured by BASF), and 3 parts of 4,4'-bis(diethylamino)benzophenone (EAB) were mixed, milled using a three-roll mill with a roll temperature of 40°C until the particle size was 5.0 μm or less, and 5 parts of TMPTA were added as necessary to adjust the viscosity to about 40 Pa·s to prepare an ink composition.

[Property measurements]
For each of Inks 1 to 16, the viscosity at 25° C. measured using a Raleigh viscometer and the slope measured at 25° C. in accordance with JIS K5101 are shown in the “Viscosity” and “Slope” columns of Tables 2 and 3, respectively.

[Emulsifying property evaluation]
For each of Inks 1 to 16, an ink composition (1 g) was kneaded with a rotating roller in the presence of dampening water (KG-502 (Komori Corporation) 1.5%) using a tabletop emulsifier (Taiyo Kikai Seisakusho), and the emulsification rate (%) of the ink composition was measured after 0.5 minutes had elapsed. The results are shown in the "Emulsification rate" column of Tables 2 and 3.

[Evaluation of Curability]
For each of Inks 1 to 16, 0.1 mL/204 ^cm2 of the printing ink composition was spread on art paper (Mitsubishi Toku Art 110K) using a RI-2 type two-split roll spreader (manufactured by Akebono Seisakusho) to prepare a test piece, which was then irradiated with ultraviolet light using a 160 W/cm metal halide lamp (focal length 13 cm, converging type, one lamp; manufactured by Heraeus). The test piece was evaluated based on the curing speed at which the ink became tack-free when touched with a finger. The evaluation criteria were based on the following three levels, and the results are shown in the "Curability" column of Tables 2 and 3.
(Evaluation criteria)
◯: The curing speed is 100 m/min or more. Δ: The curing speed is 60 m/min or more and less than 100 m/min. ×: The curing speed is less than 60 m/min.

[Evaluation of Gloss]
The gloss value was measured using the test pieces that became tack-free as a result of the above-mentioned evaluation of curability. The 60° reflected gloss was measured using a Murakami digital gloss meter (manufactured by Murakami Color Research Laboratory). The results are shown in the “Gloss” column of Tables 2 and 3.

[Evaluation of stains on printed paper]
Actual printing was carried out using a printing press for each of Inks 1 to 16, and the staining of the printed paper during the printing was evaluated. For printing, a LITHRONE LS426 printing press was used, the dampening water was KG-502 (1.5%; manufactured by Komori Corporation), and the printing paper was Mitsubishi Special Art Paper (Kikuban), and the degree of staining on the printed paper was evaluated when the water dial was lowered by 5 points from the standard water amount. The evaluation criteria were as follows, and the results are shown in the "Staining of Printed Paper" column in Tables 2 and 3.
○: No staining of the printed surface was observed. ×: Staining of the printed surface was observed.

As can be seen from Tables 2 and 3, the ink compositions prepared using resins 1 to 16 according to the present invention exhibited practical properties, emulsification, curing speed and gloss, and also performed well with no smudges in actual printing.

Claims (2)

An ester exchange step of preparing a reaction intermediate by subjecting a vegetable oil and/or a fatty acid ester thereof to an ester exchange reaction with any one of the following (1) to (3);
and a condensation polymerization step of condensing and polymerizing the reaction intermediate in the presence of a polyhydric alcohol,
The method for producing a rosin-modified alkyd resin for use in preparing an active energy ray-curable offset printing ink composition is characterized in that the vegetable oil and/or fatty acid ester thereof is selected so that the solubility parameter sp value of the obtained rosin-modified alkyd resin as determined by a turbidity point measurement method is 9.0 to 11.0 (cal/ ^cm3 ) ^1/2 and the oil length is 50 to 85.
(1) Resin acids and polybasic acids (2) Resin acid derivatives having multiple carboxyl groups (3) Resin acid derivatives having multiple carboxyl groups and polybasic acids 2. The method for producing a rosin-modified alkyd resin for use in preparing an active energy ray-curable ink composition for offset printing according to claim 1, wherein the vegetable oil is coconut oil or palm kernel oil.