JP2005290084A - Ink composition for lithography - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an ink composition for waterless lithography, excellent in anti-picking property, ink adherability and anti-scumming property and having very high practicality; to make it possible to obtain a print excellent in gloss/dots reproducibility using the ink; and in addition to provide a printing ink and a print excellent in environmental safety in that volatile ingredients from the printing ink can be controlled or eliminated. <P>SOLUTION: The ink composition for lithography contains an α-olefin polymer and does not contain a rosin-modified phenolic resin. Preferably, the α-olefin polymer has a weight average mol. wt. of ≤3,000, a kinematic viscosity of ≤1,300 cSt (Ð40°C) and a solubility parameter of 6-10 (cal/cc)<SP>0.5</SP>(Ð25°C), and is obtained by polymerizing an 8-12C olefin. Furthermore, an environment-compatible ink is also obtainable by not incorporating a mineral oil as the solvent component. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a lithographic printing ink composition that responds to speeding up of printing presses and lowering of paper used, and therefore has excellent fluidity, paper peeling resistance, fleshing property, gloss, excellent stain resistance, and environmental safety. The present invention relates to a lithographic printing ink composition in consideration of the above.

Lithographic printing, which is the mainstream of printing, supplies dampening water to non-image areas, and forms image areas and non-image areas using dampening water and ink repulsion. However, this lithographic printing method is largely caused by the emulsification of dampening water and dampening water and ink, and a great deal of equipment, consumables, time and skilled technology are currently used to control it. But it is necessary.

A waterless lithographic printing method has been proposed as a method for solving the problem related to the fountain solution, and in particular, a method of printing by providing silicone rubber in the non-image area in order to show ink repellency instead of the fountain solution Has been put to practical use. In such waterless lithographic printing, printing with a conventional oil-based ink does not provide sufficient ink resilience in non-image areas, and it is known that background smudges are undesirable, and a special ink is required. It is said that. The phenomenon of scumming in waterless printing is due to the temperature rise caused by friction of the drive unit and rollers of the printing press during printing, and because the dampening solution is not used, the effect of cooling the printing plate due to water evaporation is lost. As the temperature rises, the cohesive strength of the ink itself decreases, and the ink adheres to the non-image area where the ink should repel the ink, so that a normal printed image cannot be obtained.

Furthermore, in recent years, there has been a high social demand for environmentally friendly printing materials, and the aforementioned waterless lithographic printing recommendations and non-VOC sheet-fed inks have been developed. There is a further demand for reducing hormone substances and aldehydes. Although volatile organic solvents that become VOCs are generally used for lithographic printing inks themselves, alkylphenols and aldehydes themselves are not blended during ink production, but as raw materials for rosin-modified phenolic resins that are raw materials Generally used. Considering the disposal and recycling of printed materials, it is desirable to develop a lithographic printing ink composition composed of materials that do not use the raw materials, but various characteristics as a lithographic printing ink composition that satisfy the requirements and are required. Ink with a sufficient amount has not been put to practical use.

For example, Japanese Patent No. 3317512 describes a technique for substituting petroleum-based solvents with saturated mixed fatty acid esters derived from vegetable oil, but the ability to dissolve in resins is not limited to petroleum-based solvents even if the solvent is simply replaced. Since fatty acid esters are very different, there is a problem that ink characteristics such as set and drying properties are greatly deteriorated. Japanese Patent Application Laid-Open No. 2000-159867 describes a technique of a resin composition that replaces rosin-modified phenolic resin, but the balance of molecular weight, solubility, and softening point, which is a resin characteristic compared with rosin-modified phenolic resin. However, it is inevitable that the viscoelastic behavior as a vehicle is different and has not been put into practical use. Furthermore, Japanese Patent No. 3392113 describes a printing ink composition that uses a rosin-modified phenol resin and contains a polymer composed of an olefin monomer and a diene monomer and does not contain a petroleum solvent, but is not sufficient in terms of environmental considerations. Although polymers exemplified as being effective for blocking depending on conditions, the viscosity of the ink is increased, so that there is a problem that the ink characteristics deteriorate such as fluidity and transferability.
Japanese Patent No. 3317512 JP 2000-159867 A Japanese Patent No. 3392113

The problem to be solved by the present invention overcomes the above-mentioned problems and copes with the increase in the speed of printing presses and the lowering of paper used. It is an object of the present invention to provide a lithographic printing ink composition that is excellent in balance and is environmentally friendly.

That is, the present invention relates to an ink composition for lithographic printing, which contains an α-olefin polymer and does not contain a rosin-modified phenol resin.
In the present invention, the α-olefin polymer has a weight average molecular weight of 3000 or less, a kinematic viscosity of 1300 cSt (@ 40 ° C.) or less, and a solubility parameter of 6 to 10 (cal / cc) ^0.5 (@ 25 ° C.). The present invention relates to a composition for a lithographic printing ink.
The present invention also relates to the above lithographic printing ink composition, wherein the α-olefin polymer is obtained by polymerizing an α-olefin having 8 to 12 carbon atoms.
In addition, the present invention contains rosin and / or polymerized rosin and / or petroleum resin, unsaturated carboxylic acid or anhydride thereof, aliphatic polybasic acid, and polyester resin reacted with alcohol as a binder resin raw material. The above-described lithographic printing ink composition.
The present invention also relates to the above lithographic printing ink composition characterized in that it contains one or a plurality of resins selected from alkyd resins, petroleum resins, and cyclized rubbers as a binder resin.
Furthermore, this invention relates to the said lithographic printing ink composition characterized by containing the alpha olefin which has a C12-C18 linear or branched structure.
Furthermore, this invention relates to the said lithographic printing ink composition characterized by not containing mineral oil as a solvent component.
Furthermore, this invention relates to the said lithographic printing ink composition whose lithographic printing ink is a waterless lithographic printing ink.
In addition, the present invention relates to a printed matter using the above lithographic printing ink composition.

  By the method of the present invention, an ink composition for waterless lithographic printing having excellent paper resistance, fleshing property, and excellent stain resistance is obtained, and the ink is used for gloss and halftone reproducibility. Excellent printed matter can be obtained. In addition, it is possible to obtain a printing ink and printed matter excellent in environmental safety that can suppress or eliminate volatile components from the printing ink.

The α-olefin polymer that can be used in the present invention is fluidity, transferability, inking property, and stain resistance, which are feared in an ink system using a binder resin that does not contain a rosin-modified phenolic resin that is conventionally used in lithographic printing inks. Examples thereof include polymers having an effect of improving gloss and the like, such as isoprene, isobutylene, hexene, octene, nonene, decene, undecene, dodecene, and tridecene.

The α-olefin polymer used in the present invention may have any structure as long as the weight average molecular weight is 3000 or less, but considering the flow characteristics and gloss of the ink, it is a wax-free olefin having an isoparaffin structure having no side chain. Polymers are preferably used. The weight average molecular weight of the α-olefin polymer is preferably 200 to 1500. When the weight average molecular weight exceeds 3,000, the fluidity, the inking property, the transferability, and the gloss of the ink are deteriorated.

Furthermore, the kinematic viscosity of the α-olefin polymer is preferably 1300 cSt or less at 40 ° C. When the molecular weight exceeds 1,300 cSt, a wax-like form called so-called paraffin wax is formed in view of the molecular weight, and blocking and friction resistance can be obtained, but a printed matter having desired flow characteristics and gloss cannot be obtained.

The solubility parameter of the α-olefin polymer at 25 ° C. is preferably 6 to 10 (cal / cc) ^0.5 . Generally, the solubility parameter of the main solvent and resin used in printing ink is almost 6 to 12 (cal / cc) ^0.5. Therefore, it is necessary to use an α-olefin polymer in a region close to that. This is preferable. If the solubility parameter is 15 (cal / cc) ^0.5 or more, a difference in compatibility with the vehicle occurs, resulting in an increase in viscosity.

Α-olefin polymer preferably having a weight average molecular weight of 3000 or less, a kinematic viscosity of 1300 cSt (@ 40 ° C.) or less, and a solubility parameter of 6 to 10 (cal / cc) ^0.5 (@ 25 ° C.) It is preferable to use an α-olefin having 8 to 12 carbon atoms as a base α-olefin monomer. When α-olefins having less than 8 or more than 12 carbon atoms are used, the degree of difficulty increases in terms of controlling the viscosity and solubility parameters of the polymer structure and the end point of the reaction. An α-olefin having a carbon number within the above range is optimal.

The α-olefin polymer can be added in any step of the step of producing the ink. For example, it is possible to mix and stir together with a material arbitrarily selected from binder resins, vegetable oils, fatty acid esters, petroleum-based solvents and gelling agents to form a vehicle. The α-olefin polymer can be passed alone into the vehicle mixture in an arbitrary step. The addition amount is preferably 0.1 to 10% by weight. If the amount is less than 0.1% by weight, sufficient fluidity and gloss cannot be obtained, and if it exceeds 10% by weight, the stain resistance is insufficient although the gloss and fluidity are improved.

The binder resin used in the present invention is a polyester resin obtained by reacting rosin and / or polymerized rosin and / or petroleum resin, unsaturated carboxylic acid or anhydride thereof, aliphatic polybasic acid, alcohols as a raw material. Features.

Since the ester resin of the present invention uses polymerized rosin in addition to rosin, which is a monocarboxylic acid generally used for rosin-modified phenolic resins, it is modified with phenol that may liberate formaldehyde. Even if not, it has crosslinkability. Furthermore, the esterification reaction product obtained simply by the esterification reaction of polymerized rosin and polyhydric alcohol is too polar as an ink resin, but a mixture of rosins and unsaturated carboxylic acid or aliphatic polybasic acid is esterified. Since long-chain alkyl is introduced into the resin skeleton of the esterification reaction product, the polarity can be optimally controlled.

The rosin used in the present invention is, for example, a natural rosin such as gum rosin, tall oil rosin, wood rosin, a polymerized rosin derived from the natural rosin, or a disproportionated or hydrogenated natural rosin or polymerized rosin. Stabilized rosin and the like.

The polymerized rosin used in the present invention refers to a polymer obtained by polymerizing rosin to increase the melting point, and generally refers to those having a softening point of 90 to 140 ° C. and an acid value of 140 to 160.

In addition, instead of rosin or polymerized rosin, rosins have unsaturated bonds, so they can be obtained by adding unsaturated carboxylic acids or unsaturated polybasic acids to the natural rosin or polymerized rosin by Diels-Alder reaction or ene reaction. The use of unsaturated acid-modified rosin or unsaturated acid-modified polymerized rosin is a preferred embodiment in the present invention. Examples of these unsaturated acid-modified rosins include maleic acid-modified rosin, maleic anhydride-modified rosin, fumaric acid-modified rosin, itaconic acid-modified rosin, crotonic acid-modified rosin, cinnamic acid-modified rosin, acrylic acid-modified rosin, and methacrylic acid. Modified rosins and the like, or acid-modified polymerized rosins corresponding to these, are mentioned, and those modified with about 1 to 30 parts by weight of unsaturated acids with respect to 100 parts by weight of raw material rosins are preferred. Examples of the conditions for the addition reaction include the following conditions.

The rosin is melted at 200 ° C., and the unsaturated carboxylic acid or unsaturated polybasic acid is added at once or gradually. After the melting, the addition reaction is completed by maintaining the temperature for about 1 hour.

In this addition reaction, it is possible to add petroleum resin or the like as an extender. By modifying the polymerized rosin with an unsaturated carboxylic acid or unsaturated polybasic acid in this way, the resin can easily have a cross-linked structure, and the molecular weight increases so that the ink viscosity when ink is used increases and the workability is improved. be able to. Pre-acid-modified rosins may be used as starting materials, and even if rosin or polymerized rosin is used to add and mix unsaturated carboxylic acid or aliphatic polybasic acid during ester resin synthesis and react simultaneously with esterification, the resin properties are significant There is no difference.

The ester resin used in the present invention is preferably obtained by using a petroleum resin, an unsaturated carboxylic acid or its anhydride, an aliphatic polybasic acid, or a polyhydric alcohol and mixing and reacting these raw materials. The ester resin has a cross-linked structure, and has a molecular weight and viscosity that are high enough to be preferred for a lithographic printing ink resin. In particular, a resin or resin synthesized by performing the above-described heating reaction using 0.5 to 30 parts by weight, more preferably 2 to 20 parts by weight of an unsaturated carboxylic acid or an anhydride thereof with respect to 100 parts by weight of a petroleum resin. A composition can be illustrated. That is, by utilizing an intramolecular unsaturated bond of a petroleum resin, an addition reaction with an unsaturated carboxylic acid or an anhydride thereof is performed to introduce a carboxyl group into the petroleum resin skeleton. In the final product resin, this newly introduced carboxyl group was used to introduce a crosslinked structure by ester bond formation. Therefore, a product obtained by subjecting a petroleum resin to an unsaturated carboxylic acid or an anhydride thereof in advance, that is, a product obtained by adding an unsaturated carboxylic acid or an anhydride to a carbon skeleton of a petroleum resin molecule. Instead of petroleum resin and unsaturated carboxylic acid or anhydride thereof, a starting material may be used.

The petroleum resin used in the present invention contains indene, methylindene, vinyltoluene, styrene, α-methylstyrene, β-methylstyrene, cyclopentadiene, dicyclopentadiene, methylbutene, isoprene, pentene, cyclopentene, pentadiene and the like as components. A petroleum resin having a double bond can be exemplified. Examples of petroleum resins having double bonds include DCPD petroleum resins made from cyclopentadiene and dicyclopentadiene; C5 petroleum resins such as pentene, pentadiene and isoprene; indene, methylindene, vinyltoluene, styrene, α-methyl C9 petroleum resin made from styrene, β-methylstyrene, etc., copolymer petroleum resin consisting of DCPD and C5 raw materials, copolymer petroleum resin consisting of DCPD and C9 raw materials, C5 and C9 Examples thereof include copolymer petroleum resins composed of raw materials, copolymer petroleum resins composed of the above-mentioned DCPD, C5, and C9 based materials, and are produced using no catalyst or Friedel-Crafts type catalyst (cationic polymerization). In particular, it is easy to impart polar groups, and it is easy to adjust to the desired softening point. Therefore, DCPD petroleum resin, copolymer petroleum resin consisting of DCPC and C5 raw materials, copolymer petroleum resin consisting of DCPD and C9 raw materials A copolymer petroleum resin composed of DCPD, C5 and C9 materials is preferred.

In addition, by utilizing the intramolecular unsaturated bond of petroleum resin, an addition reaction with unsaturated carboxylic acid or its anhydride is carried out to introduce a carboxyl group into the petroleum resin skeleton. The cross-linked structure was introduced by forming an ester bond using the carboxyl group introduced into the structure. Therefore, a product obtained by subjecting a petroleum resin to an unsaturated carboxylic acid or an anhydride thereof in advance, that is, a product obtained by adding an unsaturated carboxylic acid or an anhydride to a carbon skeleton of a petroleum resin molecule. Instead of petroleum resin and unsaturated carboxylic acid or anhydride thereof, a starting material may be used.

The unsaturated carboxylic acid or anhydride thereof used for the addition reaction with the above-mentioned rosin, polymerized rosin, and petroleum resin of the present invention is generally a C3-C36, preferably C3-C18 chain unsaturated. Preferred are carboxylic acids, unsaturated dicarboxylic acids or anhydrides thereof, or substituted chain unsaturated carboxylic acids substituted with an aromatic ring that can be conjugated with a carbon-carbon double bond such as the chain unsaturated carboxylic acid. Is. More specifically, various α, β-unsaturated carboxylic acids or anhydrides used in Diels-Alder reaction or Alder ene reaction can be preferably used. For example, a chain α-, β-unsaturated monocarboxylic acid having 3 to 18 carbon atoms, an α, β-unsaturated dicarboxylic acid or an anhydride thereof, or a carbon such as the chain α, β-unsaturated carboxylic acid. A substituted chain α, β-unsaturated carboxylic acid substituted with an aromatic ring that can be conjugated with a carbon double bond is preferred, and specific examples thereof include a chain α, β-unsaturated monocarboxylic acid having 3 to 5 carbon atoms. Α, β-unsaturated dicarboxylic acid having 4 to 8 carbon atoms, such as acrylic acid (2-propenoic acid), methacrylic acid (α-methylacrylic acid), crotonic acid (trans-2-butenoic acid), which are carboxylic acids, Its anhydrides are maleic acid (cis-butenedioic acid), maleic anhydride, fumaric acid (trans-butenedioic acid), itaconic acid (methylenesuccinic acid), itaconic anhydride, citraconic acid (methylmaleic acid), Citraconic anhydride, tetrahydrophthalic acid or its anhydride Cinnamic acid which is a substituted chain α, β-unsaturated carboxylic acid substituted with an aromatic ring which can be conjugated with a carbon-carbon double bond such as chain α, β-unsaturated carboxylic acid (3 -Phenyl-2-propenoic acid) and the like can be mentioned as examples of more preferable α, β-unsaturated monocarboxylic acid, α, β-unsaturated dicarboxylic acid or anhydride thereof. Of these, acrylic acid (2-propenoic acid), methacrylic acid (α-methylacrylic acid), maleic acid (cis-butenedioic acid), maleic anhydride, and the like are more preferable.

In addition, unsaturated fatty acids derived from natural drying oils as well as semi-drying oils are also preferred. More specifically, it is linseed oil fatty acid, soybean oil fatty acid, tall oil fatty acid, etc., and these dry oils and semi-dry oils are involved in the formation of glycerides, for example, and various kinds of free oils obtained by liberation from them. Saturated fatty acids are also preferably used. Various unsaturated fatty acids derived from the above-mentioned drying oil and semi-drying oil may include not only the free type but also the ester type. In addition, similar to petroleum resins, unsaturated carboxylic acids or anhydrides thereof may be used as a mixture of a plurality of types. For example, a mixture of the above-exemplified α, β-unsaturated carboxylic acid and unsaturated fatty acid derived from drying oil and semi-drying oil can be used.

In addition, although the usage-amount ratio of petroleum resin and unsaturated carboxylic acid or its anhydride is dependent on the average molecular weight of petroleum resin and the molecular weight of unsaturated carboxylic acid or its anhydride, it is generally with respect to 1 molecule of petroleum resin. The unsaturated carboxylic acid or its anhydride is preferably selected in the range corresponding to 0.1 to 6 molecules, more preferably 0.3 to 3 molecules. In general, when the weight ratio of the obtained resin is replaced with the weight ratio in consideration of the weight average molecular weight and viscosity of the obtained resin, the weight ratio range described above is generally a preferable range.

The ratio of the amount of rosin, petroleum resin, and unsaturated carboxylic acid or anhydride used depends on the average molecular weight of the rosin and petroleum resin and the molecular weight of the unsaturated carboxylic acid or anhydride, but is largely rosin or It is preferable to select an unsaturated carboxylic acid or an anhydride thereof in a range corresponding to 0.1 to 6 molecules, more preferably 0.3 to 3 molecules, per molecule of petroleum resin. In general, considering the weight average molecular weight of the obtained resin and the viscosity within the allowable range described later, the above-mentioned usage ratio is replaced with a weight ratio, and the above-described weight ratio range is generally preferable. It becomes a range.

The aliphatic polybasic acid used in the present invention mainly forms an ester bond with an aliphatic monoalcohol, aliphatic dialcohol, or polyhydric alcohol and becomes a part of the crosslinked structure of the resin. The aliphatic polybasic acid used in the present invention mainly forms an ester bond with the polyhydric alcohol and becomes a part of the crosslinked structure of the resin. Therefore, although various aliphatic polycarboxylic acids can be used, a linear alkanedioic acid having 2 to 32 carbon atoms or an anhydride thereof is preferable, for example, succinic acid (butanedioic acid), adipic acid (hexanedioic acid), Azelaic acid (1,7-heptanedicarboxylic acid), sebacic acid (1,8-octanedicarboxylic acid) and anhydrides thereof such as succinic anhydride are more preferred. Furthermore, diacid, trimer acid, diacid or unsaturated fatty acid adduct obtained by reaction of unsaturated fatty acid and α, β-unsaturated carboxylic acid, or acid anhydrides corresponding to these are also preferable. Can be cited as a thing. For example, dimer acid and trimer acid are dimerized and trimerized various unsaturated fatty acids, but oleic acid derived from vegetable oil is used as a raw material and is relatively high molecular weight and is commercially available. Dimer acid can be used. The addition amount of the aliphatic polybasic acid is 0.1% of the total amount of rosins, petroleum resin, unsaturated carboxylic acid or anhydride thereof, or 100 parts of rosins previously modified with unsaturated carboxylic acid and petroleum resin. Is preferably 10 to 10 parts by weight, and more preferably 0.5 to 7 parts by weight.

As the alcohols used in the present invention, one or more alcohols selected from polyhydric alcohols and aliphatic monoalcohols can be used. As the aliphatic monoalcohol, those showing fat solubility derived from the carbon chain constituting the aliphatic monoalcohol are used. Therefore, it is selected from a linear or cyclic monohydric alcohol having 8 or more carbon atoms. For example, a primary alcohol having a straight chain or branched chain having 8 or more carbon atoms, which is more lipophilic, is preferably used. Can do. More preferably, the hydrocarbon chain is linear and a primary alcohol having a hydroxyl group at the end is used. Moreover, when the said linear hydrocarbon chain is saturated or has an unsaturated bond, the structure in which the unsaturated bond is located in the terminal is more preferable. For example, as a saturated primary alcohol having 8 or more carbon atoms, 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-icosanol, 1-henicosanol, 1-docosanol, 1-tricosanol, 1-tetracosanol, 1-pentacosanol 1-hexacosanol, 1-heptacosanol, 1-octacosanol, 1-nonacosanol, 1-triacontanol, 1-hentriacontanol, 1-dotriacontanol, 1-tritriacontanol, 1-tetratriacontanol 1-pentatriacontanol, 1 Heptatriacontanol, and β, γ-unsaturated primary alcohols having 8 or more carbon atoms include 2-octen-1-ol, 2-dodecene-1-ol, 2-undecen-1-ol, 2- Tetradecene-1-ol, 2-pentadecene-1-ol, 2-hexadecene-1-ol, 2-heptadecene-1-ol, 2-octadecene-1-ol, and terminal unsaturated alcohols having 8 or more carbon atoms Examples thereof include 8-nonen-1-ol, 10-undecen-1-ol, 11-dodecene-1-ol, 12-tridecene-1-ol, 15-hexadecene-1-ol, and the like. Furthermore, in addition to the above-mentioned primary alcohols having a linear hydrocarbon chain, a short hydrocarbon group is substituted on the long chain carbon skeleton to form a branch, but this is derived from the long chain carbon skeleton. Similar monohydric alcohols that substantially retain fat solubility, such as secondary alcohols in which short hydrocarbon groups are present on the carbon in which the hydroxyl groups are present, are also preferred. By containing these monovalent higher alcohols in the molecule, the ester bond is given lipophilicity and a branched structure is introduced into the resin, so that the solubility of the resin can be further improved. The monovalent higher alcohol used here may be either a natural alcohol or a synthetic alcohol as long as the structure of the carbon chain matches the purpose. The amount of monoalcohol added is preferably about 2 to 10% of the total of rosins, petroleum resins, unsaturated carboxylic acids, aliphatic polybasic acids, and alcohols.

Examples of the polyhydric alcohol used in the present invention include chain polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol (1,2-propanediol), and dipropylene glycol. , Tripropylene glycol, butylene glycol (butanediol), neopentyl glycol (2,2-dimethyl-1,3-propanediol), hexanediol, glycerin, trimethylolpropane, ditrimethylolpropane, pentaerythritol (C (CH ₂ OH) ₄ ), dipentaerythritol, D-sorbitol (D-glucitol), etc., as well as alicyclic polyhydric alcohols such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol (1,4-diethanol) Methylolcyclohexane) It is.

As a starting material, polyhydric alcohol is used for esterification reaction of resin formation, and the addition amount thereof is rosins and unsaturated acid-modified rosins, petroleum resins and unsaturated carboxylic acid-modified, unsaturated. What is necessary is just to add 0.3 equivalent-excess amount at least with respect to 1 equivalent of carboxyl groups which carboxylic acid or its anhydride, and an aliphatic polybasic acid have. It is more preferable to add 0.5 to 2 equivalents with respect to 1 equivalent of the carboxyl group, and it is more preferable to carry out the reaction by adding 0.9 to 1.2 equivalents. That is, an adduct of rosin and polymerized rosin, unsaturated carboxylic acid-modified rosin or petroleum resin and unsaturated carboxylic acid forms an ester with a polyhydric alcohol, and the hydroxyl group and aliphatic polybasic remaining in the polyhydric alcohol. When the acid forms an ester, a crosslinked structure is introduced into the resin. Therefore, it is more preferable that the amount of polyhydric alcohol added is 0.9 to 1.2 equivalents relative to 1 equivalent of carboxyl groups, which is generally the amount required for the two types of esterification reactions. In addition, in consideration of the fact that a crosslinked structure is introduced into the resin by the esterification reaction, if a polyhydric alcohol containing a polyhydric alcohol of a trihydric alcohol or higher is used, a crosslinked structure is formed there. More favorable results are obtained.

In the above reaction, the addition reaction of rosin and unsaturated carboxylic acid or its anhydride, the addition reaction of petroleum resin and unsaturated carboxylic acid or its anhydride, and the esterification reaction of polyhydric alcohol compete with each other. As it occurs, the product is a mixture of various building blocks. If the addition reaction between the rosin and the unsaturated carboxylic acid or its anhydride or the condition where the addition reaction between the petroleum resin and the unsaturated carboxylic acid or its anhydride proceeds preferentially, the resin viscosity becomes higher. That is, the Alder ene reaction or Diels-Alder reaction usually starts only by heating, but more favorable results can be obtained by adding compounds that catalyze these addition reactions. Note that even when the esterification of the unsaturated carboxylic acid proceeds first, the unsaturated carboxylic acid ester also retains the reactivity in the above-described alder ene reaction or Diels-Alder reaction, so that there is no significant difference.

When performing the heating reaction, the raw material rosins, petroleum resins, unsaturated carboxylic acids or anhydrides thereof, unsaturated polybasic acids, aliphatic polybasic acids, aliphatic monoalcohols or polyhydric alcohols are used without any catalyst or catalyst. A method of reacting simultaneously in the presence can be adopted. Alternatively, a rosin and an unsaturated carboxylic acid or anhydride thereof, or a petroleum resin and an unsaturated carboxylic acid or anhydride thereof are separately heated, and then an aliphatic polybasic acid or a polyhydric alcohol is added to form an ester. A method of forming and adding a plurality of binder resins at the time of vehicle production can also be employed. That is, according to the reaction method and procedure to be employed, the order of addition and the timing of addition of each raw material can be appropriately selected. Furthermore, a method is used in which an ester is formed by adding an aliphatic polybasic acid or a polyhydric alcohol from a product obtained by heating and reacting a petroleum resin and an unsaturated carboxylic acid or its anhydride in advance. However, there is no substantial difference in the resin obtained.

When using the catalyst, Lewis acid catalyst used for cationic reaction as Friedel-Crafts catalyst, for example, boron trifluoride, boron trifluoride and phenol, ether, acetic acid complex, aluminum chloride, etc. Is preferably added. For example, the ene reaction of alder occurs when heated, but the reaction tends to be easy when a Lewis acid coexists, and the Friedel-Crafts catalyst itself catalyzes cation graft polymerization. Alternatively, the reaction system may be a known acid catalyst such as paratoluenesulfonic acid, methanesulfonic acid, and sulfuric acid that serves as a catalyst for the esterification reaction, an alkali catalyst such as sodium hydroxide, potassium hydroxide, and calcium hydroxide, or magnesium oxide, It is also preferable to add a divalent metal compound such as zinc oxide or calcium oxide. Among the compounds added as the catalyst, in order to increase the viscosity of the resulting resin, the total weight of rosins, petroleum resins, unsaturated carboxylic acids or anhydrides, aliphatic polybasic acids, and alcohols is used. On the other hand, it is preferable to add a divalent metal compound in an amount of 0.1% to 3%. Specifically, a divalent metal compound such as zinc, magnesium or calcium, in particular, these divalent metals, that is, zinc or magnesium. It is more preferable to use calcium oxide or hydroxide.

In the heating reaction, the reaction temperature is suitably selected in the range of 100 to 290 ° C, and more preferably in the range of 200 to 270 ° C. In addition, the heating reaction temperature can also select the temperature which does not differ substantially from said suitable range according to the raw material used and its composition. Optimum reaction time includes rosins, petroleum resins, unsaturated carboxylic acids or their anhydrides, aliphatic polybasic acids, polyhydric alcohol components in the raw materials, and zinc, magnesium added as a catalyst, Although it changes depending on the amount of calcium oxide, hydroxide, etc., the above temperature range is usually in the range of 2 to 20 hours, preferably in the range of 3 to 10 hours.

The resin for printing ink of the present invention is an adduct selected from the rosins, petroleum resins and unsaturated carboxylic acids obtained by the above heating reaction, and an aliphatic polybasic acid and an alcohol are ester-bonded. The main component is a polymerized resin, but within a range not departing from the object of the present invention, a small amount of other conventionally known resins, for example, rosin-modified phenolic resin using formaldehyde as a raw material is added to form a composite. This type of resin composition can substantially avoid the possibility of formaldehyde scattering in a conventional rosin-modified phenolic resin. In addition to the raw petroleum resin, an aliphatic petroleum resin obtained by polymerizing C5 olefins can also be added and mixed.

If necessary, one or more resins selected from alkyd resins, petroleum resins, and cyclized rubbers can be used in combination as a binder resin.

The alkyd resin used in the present invention is preferably an oil-modified alkyd resin comprising a polybasic acid, a polyhydric alcohol, and an oil.

The petroleum resin used in the present invention contains indene, methylindene, vinyltoluene, styrene, α-methylstyrene, β-methylstyrene, cyclopentadiene, dicyclopentadiene, methylbutene, isoprene, pentene, cyclopentene, pentadiene and the like as components. A petroleum resin having a double bond can be exemplified. Examples of petroleum resins having double bonds include DCPD petroleum resins made from cyclopentadiene and dicyclopentadiene; C5 petroleum resins such as pentene, pentadiene and isoprene; indene, methylindene, vinyltoluene, styrene, α-methyl C9 petroleum resin made from styrene, β-methylstyrene, etc., copolymer petroleum resin consisting of DCPD and C5 raw materials, copolymer petroleum resin consisting of DCPD and C9 raw materials, C5 and C9 Examples thereof include copolymer petroleum resins composed of raw materials, copolymer petroleum resins composed of the above-mentioned DCPD, C5, and C9 based materials, and are produced using no catalyst or Friedel-Crafts type catalyst (cationic polymerization). In particular, it is easy to impart polar groups, and it is easy to adjust to the desired softening point. Therefore, DCPD petroleum resin, copolymer petroleum resin consisting of DCPC and C5 raw materials, copolymer petroleum resin consisting of DCPD and C9 raw materials A copolymer petroleum resin composed of DCPD, C5 and C9 materials is preferred.

The cyclized rubber used in the present invention can be obtained by acid treatment of natural or synthetic rubber. The weight average molecular weight of the cyclized rubber used is preferably 5,000 to 50,000, more preferably 8,000 to 30,000. If the weight average molecular weight of the cyclized rubber is 5,000 or less, it is difficult to obtain sufficient scumming resistance. Further, it is preferable that the temperature range in which the mixed solution of the cyclized rubber diluted to 10% by weight in the AF solvent 5 changes from a transparent state to a cloudy state is in the range of 50 ° C to 90 ° C.

A waterless lithographic printing ink composition that is further excellent in background stain, fluidity, and gloss can be obtained by adding an α-olefin having a straight chain or branched structure having 12 to 18 carbon atoms as necessary. . The amount of α-olefin added is not particularly limited, but it is preferably added in the range of 1 to 15% by weight in accordance with the characteristics of the binder resin used.

Animal and vegetable oils, fatty acid esters, and fatty acid ethers can be used as solvents that can be used when blended as a non-petroleum solvent-based ink composition that does not contain mineral oil as a solvent component.
Examples of animal and vegetable oils include linseed oil, soybean oil, tung oil, tall oil, cottonseed oil, safflower oil, rapeseed oil, dehydrated castor oil, and regenerated vegetable oil.

Examples of fatty acid esters include alkyl esters of saturated and / or unsaturated fatty acids having 8 to 20 carbon atoms. . Fatty acids used in fatty acid esters are derived from vegetable oils such as palm kernel oil, coconut oil, cottonseed oil, peanut oil, palm oil, corn oil, olive oil, cucumber seed oil, flaxseed oil, linseed oil, corn oil, soybean oil, safflower oil The thing derived from animal oils, such as a whale oil, a cocoon oil, a match scented whale body oil, and a match scented whale brain oil, can also be used. Since these fatty acids are usually composed of multiple fatty acids, they are separated and purified into capric acid, lauric acid, myristic acid, palmitic acid, myristoleic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, etc. It is more preferable to use them alone or in combination. It is more preferable that the general formula the number of carbon atoms in R ₁ is an alkyl and or alkenyl group having 10 to 16 use the esters of R ₁ COOR ₂ as heatset inks. In order to maintain the drying property, fatty acid esters of palm oil and palm kernel oil are preferable among vegetable oils. Because the main fatty acid components of palm oil and palm kernel oil are capric acid (C ₁₀ ), lauric acid (C ₁₂ ), myristic acid (C ₁₄ ), palmitic acid (C ₁₆ ), etc. This is because it consists of short-chain saturated fatty acids and is advantageous in terms of volatility, odor, solubility, oxidation stability, and the like. Examples of the alkyl group of the fatty acid ester include linear or branched alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl ester, and 2-ethylhexyl. The alkyl group also has lower volatility when the number of carbon atoms is smaller. However, there is a problem that the blanket usually used for lithographic printing swells and the positive type PS plate has poor printing durability.

Furthermore, in order to improve the drying property of the ink and reduce the odor, it is desirable to use these fatty acid esters after refining and separating them to remove low-boiling substances that cause odor. As the fatty acid ester derived from coconut oil used in the printing ink composition according to the present invention, lauric acid methyl ester, lauric acid isopropyl ester, and lauric acid isobutyl ester are most preferably used. These may be used alone or in combination of two or more. These fatty acid esters are preferably contained in the lithographic printing ink composition in an amount of 15 to 55% by weight.

Examples of fatty acid ethers include ethers derived from saturated and / or unsaturated fatty acid alcohols having 6 to 20 carbon atoms. Examples of the ether of the present invention include di-n-octyl ether, dinonyl ether, diheptyl ether, dihexyl ether, nonyl hexyl ether, nonyl heptyl ether, nonyl octyl ether, R ₃ and R ₄ each having 6 to 6 carbon atoms. Ether which is an alkyl group of 9 is more preferable in terms of solubility with the binder resin, setting, and drying properties. The above-mentioned animal and vegetable oils, esters and ethers, which are non-mineral oil-based solvents used in the present invention, can be used either during vehicle production or during ink production.

In the offset ink composition of the present invention, additives for printing inks such as pigments, vegetable oils, gelling agents, antifriction agents, and dryers can be used as needed. Examples of gelling agents are those generally called aluminum chelates such as alkyl acetoacetate and aluminum diisopropylate. Examples of antifriction agents include polyethylene wax, PTFE wax, and solid paraffin wax.

The offset ink composition of the present invention can be produced by a conventionally known method. As an example, a polyester resin and vegetable oil ester or ether, and if necessary, a gelling agent is added and heated at around 200 ° C. for 1 hour to obtain a varnish. An additive such as an α-olefin polymer and an antifriction agent is blended in an ink base obtained by dispersing the pigment in this varnish with three rolls, a bead mill or the like, and prepared with an additional varnish and a vegetable oil ester or ether.

In the lithographic ink composition of the present invention, additives for printing inks such as pigments, vegetable oils, gelling agents, antifriction agents, and dryers can be used as needed. Examples of gelling agents are those generally called aluminum chelates such as alkyl acetoacetate and aluminum diisopropylate. Examples of antifriction agents include polyethylene wax, PTFE wax, and solid paraffin wax.

The offset ink composition of the present invention can be produced by a conventionally known method. As an example, a polyester resin and vegetable oil ester or ether, and if necessary, a gelling agent is added and heated at around 200 ° C. for 1 hour to obtain a varnish. An additive such as an anti-friction agent is blended in an ink base obtained by dispersing the pigment in this varnish with a three-roll, bead mill, etc., and prepared with an additional varnish and a vegetable oil ester or ether.

Lithographic ink composition of the present invention is the angular frequency ω (rad / sec) is the dynamic elastic modulus G '(dyn / cm ²⁾ when the 10 ² is preferably ^{10 3 ~10 5 (25 ℃)} . When G ′ is less than 10 ³ , the ink becomes soft and causes problems such as smearing, halftone dot crushing, misting and the like, and when G ′ exceeds 10 ⁵ , problems such as poor ink transferability and poor inking occur.

The lithographic printing ink composition of the present invention can be applied to all uses such as sheet-fed, off-line, newspaper, and metal printing used in the lithographic printing method, and includes a rosin-modified phenolic resin using an ultraviolet / electron-curable monomer or polymer. It is also possible to apply to vehicles and ink systems that are not used. More preferably, when applied to waterless lithographic printing inks, it is possible to eliminate the problems of high viscosity and deterioration of fluidity, transferability, inking property, and gloss in order to maintain conventional stain resistance.

The lithographic printing ink composition of the present invention can be printed on a substrate such as paper, plastic or metal by using a lithographic printing method. When printing is performed, ordinary blankets, plates, and rubber rolls can be used. Preferably, the blanket is a UV ink or oily-UV ink combined type, and the PS plate is a negative plate or a positive plate burned.

Hereinafter, the offset ink composition of the present invention will be described specifically and in detail by examples, but the scope of the present invention is not limited to these examples. In the following description, “parts” represents parts by weight, and “%” represents% by weight.

(Production example of ester resin A)
In a reaction vessel, 100 parts of fumaric acid, 45 parts of sebacic acid, and 85 parts of glycerin are added and mixed with 1450 parts (manufactured by Maruzen Petrochemical Co., Ltd.), which is a commercially available C5 DCPD petroleum resin, and further a catalyst. As a result, 1.5 parts of magnesium oxide was added and homogenized. The reaction vessel was heated to 270 ° C. and then reacted for 12 hours to produce a resin.

(Production example of ester resin B)
In a reaction container, 120 parts of acrylic acid, 50 parts of sebacic acid, 180 parts of pentaerythritol, and 20 parts of dodecanol were added to 1550 parts of polymerized rosin (Silvachem Silvatac 140) and 1.5 parts of zinc oxide as a catalyst. Was added. The reaction vessel was heated to 270 ° C. and then reacted for 7 hours to produce a resin.

(Production example of ester resin C)
In a reaction vessel, 600 parts of gum rosin, 550 parts of Nisseki Neopolymer 160 (manufactured by Mitsubishi Stone Corporation), which is a commercially available maleic acid-modified petroleum resin, 80 parts of maleic anhydride, 45 parts of sebacic acid, glycerin 80 parts were added and mixed, and 1.5 parts of magnesium oxide was further added as a catalyst to make uniform. The reaction vessel was heated to 270 ° C. and then reacted for 10 hours to produce a resin.

(Production example of rosin-modified phenolic resin D)
In a reaction vessel, 1500 parts of gum rosin was reacted with 1000 parts of paraoctylphenol and 400 parts of paraformaldehyde at 100 ° C. for 4 hours under a sodium hydroxide catalyst, and the resol-type phenol resin from which water had been removed was dropped at 150 ° C. and reacted for 2 hours. . Further, 95 parts of pentaerythritol was added and reacted for 12 hours using calcium hydroxide as a catalyst to prepare a resin.

(Example of varnish production)
Ester resin A, ester resin B, ester resin C, rosin-modified phenol resin D, cyclized rubber (weight average molecular weight 23000, softening point 122-138 ° C.), soybean oil-modified alkyd resin ( Oil length 80, soybean oil-modified phthalic anhydride-pentaerythritol ester), petroleum resin (maleic acid-modified C5 petroleum resin, weight average molecular weight 2300, softening point 165 ° C.). As an α-olefin polymer, olefin polymer A (decene polymer, solubility parameter 8.17 (cal / cc) ^0.5 (@ 25 ° C.), viscosity 66 cSt (@ 40 ° C., weight average molecular weight 720), olefin polymer B (octene) , Decene, mixed polymer of dodecene, solubility parameter 8.33 (cal / cc) ^0.5 (@ 25 ° C.), viscosity 1240 cSt (@ 40 ° C., weight average molecular weight 2830), olefin polymer C (decene polymer, solubility parameter) 7.9 (cal / cc) ^0.5 (@ 25 ° C.), viscosity 5 cSt (@ 40 ° C.), weight average molecular weight 284), average molecular weight 1800). AF solvent 5 (manufactured by Shin Nippon Petrochemical Co., Ltd., aroma-free ink solvent), dialen (manufactured by Mitsubishi Kasei Co., Ltd., α-olefin, average boiling point 301 ° C.), soybean oil, soybean oil fatty acid butyl ester as solvents. Aluminum chelate (aluminum diisoproxide monoethyl acetate) as a crosslinking agent.

The materials were heated and reacted at 190 ° C. for 1 hour in accordance with the formulation (parts by weight) shown in Table 1 to obtain Example varnishes 1 to 8 and Comparative example varnishes 9 to 10.

(Example of ink production)
Example varnishes 1 to 8 and comparative example varnishes 9 to 10 were used, and phthalocyanine blue (LIONOLBLUE FG7330 manufactured by Toyo Ink Mfg. Co., Ltd.) was used as a pigment according to the composition (parts by weight) shown in Table 2, using a three-roll method. Example inks 1 to 10 and comparative inks 11 to 12 were obtained (of which 11 was used for waterless ink and 14 was used for other conventional inks using dampening water).

(Evaluation of ink and printability)
With respect to Example inks 1 to 11 and Comparative example inks 12 to 14, a normal offset print using dampening water and a waterless print using no dampening water were obtained using a sheet-fed offset printing machine. Printing conditions: 2,000 sheets of coated paper are printed at a printing speed of 8000 sheets / hour, printing plate temperature is controlled to 28-31 ° C. without water, printing plate with water VS (manufactured by Fuji Photo Film Co., Ltd., waterless printing plate HG -2 (Toray Industries, Inc.)
Evaluation items: Table 3 shows the results of evaluating the obtained printed matter and ink characteristics in the following points. 1) Gloss (Measure 60-60 ° reflection gloss of the solid part, the higher the value, the better the gloss) 2) Soil (contrast (K value) between the solid part and the 70% halftone dot part, the higher the value, the more soiled 3) Slope (Measure the difference between the flow values after 100 seconds and 10 seconds using a spread meter. The higher the value, the better the fluidity)

It can be seen that Example inks 1 to 9 according to the present invention have performance equivalent to or better than that of ink using rosin-modified phenolic resin in terms of background stain resistance, gloss and fluidity, as compared with Comparative Example Ink 12. In addition, it can be seen that Example ink 10 containing no petroleum solvent is similarly superior in stain resistance, gloss and fluidity as compared with Comparative Example Ink 13. Furthermore, it can be seen that waterless lithographic printing is similarly superior in comparison between Example Ink 11 and Comparative Example Ink 14.

It is considered technically feasible to produce an environmentally conscious printing ink by applying the material of the present invention to a printing ink composition that is used in relief printing, intaglio printing, and stencil printing other than the offset printing method.

Claims (9)

An ink composition for lithographic printing comprising an α-olefin polymer and no rosin-modified phenolic resin. The α-olefin polymer has a weight average molecular weight of 3000 or less, a kinematic viscosity of 1300 cSt (40 ° C.) or less, and a solubility parameter of 6 to 10 (cal / cc) ^0.5 (25 ° C.). The composition for lithographic printing ink as described. 3. The lithographic printing ink composition according to claim 1, wherein the α-olefin polymer is obtained by polymerizing an α-olefin having 8 to 12 carbon atoms. 2. A rosin and / or a polymerized rosin and / or a polyester resin obtained by reacting an unsaturated carboxylic acid or an anhydride thereof, an aliphatic polybasic acid, or an alcohol as a binder resin raw material. The ink composition for lithographic printing according to any one of 3 to 3. The lithographic printing ink composition according to any one of claims 1 to 4, wherein the binder composition contains one or more resins selected from alkyd resins, petroleum resins, and cyclized rubbers. The lithographic printing ink composition according to any one of claims 1 to 5, comprising an α-olefin having a linear or branched structure having 12 to 18 carbon atoms. The lithographic printing ink composition according to any one of claims 1 to 6, which does not contain mineral oil as a solvent component. The lithographic printing ink composition according to any one of claims 1 to 7, wherein the lithographic printing ink is a waterless lithographic printing ink. A printed matter using the lithographic printing ink composition according to claim 1.