JP2011089021A - Vanish for offset printing ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an offset printing ink combining high fluidity with misting resistance of the ink. <P>SOLUTION: The vanish for offset printing inks includes a rosin-modified phenolic resin having a structure obtained by reacting at least a condensate of a phenol and an aldehyde, a rosin, and a polyol. The rosin-modified phenolic resin is obtained by mixing two kinds of rosin-modified phenolic resins having different weight average molecular weights. The phenol and the polyol that are the raw materials for the two kinds of rosin-modified phenolic resins having different weight average molecular weights are each substantially the same. A gel vanish for offset printing inks obtained by gelating the vanish for offset printing inks is presented. The offset printing inks include the gel vanish. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a varnish for offset printing ink, and more particularly to a varnish for offset printing ink using two types of rosin-modified phenolic resins having different weight average molecular weights.

  In general, offset printing ink is prepared by preparing a varnish for offset printing ink containing at least a resin, a solvent, etc., and further adding a gelling agent etc. to heat and gelling to obtain a gel varnish for offset printing ink. Further, it is manufactured by adding a colorant and the like thereto.

  A rosin-modified phenol resin is known as a resin contained in the varnish for offset printing ink. For example, Patent Documents 1 to 4 and the like describe a technique for producing a gel varnish by adding a gelling agent to a rosin-modified phenolic resin and heating it to produce an ink.

  In recent years, in offset printing, the printing speed of a printing press has been increased, but usually, the higher the printing speed of the printing press, the higher the fluidity of the ink is required, and the higher the printing speed of the printing press. The misting increases. However, the high fluidity of ink and the misting resistance are contradictory physical properties, and it has been difficult to keep both physical properties within a good range at the same time.

  On the other hand, it is known that two types of resins having different chemical structures are mixed and used as a varnish for printing ink (for example, Patent Document 5). However, in order to solve the above-mentioned trade-off problem, it is known that a resin that can increase the fluidity of ink and a resin that can suppress misting are mixed to clearly satisfy the two contradictory physical properties. Therefore, at least one of the above physical properties (ink fluidity) has been kept sufficiently good, and the other physical property (misting resistance) has not been sufficiently well within the range. It was.

JP-A-3-095254 JP-A-4-132778 JP-A-8-283634 JP-A-10-088052 JP 2006-045395 A

  The present invention has been made in view of the above-described background art, and an object thereof is to provide an offset printing ink that achieves both high fluidity of ink and resistance to misting.

  As a result of intensive studies to solve the above problems, the present inventor has obtained a resin before gelation which is a component (raw material) of a gel varnish contained in an offset printing ink, having a weight average molecular weight different from each other, and It was found that by using a resin obtained by mixing the same kind of rosin-modified phenolic resin with each other, it was possible to provide an offset printing ink that achieves both high fluidity of ink and resistance to misting, and the present invention was completed. It was.

That is, the present invention
At least a varnish for offset printing ink containing a rosin-modified phenol resin having a structure obtained by reacting a “condensate of phenols and aldehydes”, “rosins” and “polyols”,
The rosin-modified phenolic resin is obtained by mixing two kinds of rosin-modified phenolic resins having different weight average molecular weights, and
The phenols and the polyols, which are raw materials for the two types of rosin-modified phenolic resins having different weight average molecular weights, are substantially the same as each other,
The present invention provides an offset printing ink varnish.

  Moreover, this invention provides the gel varnish for offset printing inks characterized by gelatinizing said varnish for offset printing inks with a gelatinizer.

  The present invention also provides an offset printing ink comprising the gel varnish for offset printing ink and a colorant.

  Moreover, this invention provides the printed matter characterized by printing said offset printing ink on a base material.

  The offset printing ink obtained by using the varnish for offset printing ink of the present invention has a misting amount in a good range while maintaining the fluidity of the ink in a sufficiently high range when the tack is unified to a constant value. Can be suppressed. And according to this invention, even if the printing speed of a printing machine increases, a favorable printing condition and printed matter can be provided.

  Hereinafter, the present invention will be described, but the present invention is not limited to the following specific embodiments, and can be arbitrarily modified within the scope of the technical idea.

1. TECHNICAL FIELD The present invention relates to a varnish for offset printing ink (hereinafter sometimes simply referred to as “varnish”) used in producing an offset printing ink, and rosin is used as a resin contained in the varnish. Two types of rosin-modified phenols having a different weight average molecular weight, which are obtained by mixing two types of rosin-modified phenol resins having different weight average molecular weights, using a modified phenol resin. The phenols and the polyols, which are the raw materials for the resin, are substantially the same as each other.

  Here, “one type of rosin-modified phenolic resin” means a rosin-modified phenolic resin obtained by one synthesis, and “two types of rosin-modified phenolic resins” are those obtained by two synthesis. It refers to two rosin-modified phenolic resins having different compositions and / or molecular weights. After the synthesis reaction of the rosin-modified phenolic resin is substantially completed, a rosin-modified phenolic resin having a different composition and / or molecular weight, which is separately synthesized, is added to the reaction vessel. Is.

  “Rosin-modified phenolic resin” means at least “condensate of phenols and aldehydes” (hereinafter sometimes simply referred to as “condensate” in parentheses), rosins and polyols as essential components. It has a structure obtained by reacting.

1.1. Phenols The above “phenols” are not particularly limited. For example, phenol (coal acid); alkyl group-substituted phenol substituted with a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms; Examples include aromatic group-substituted phenols such as milphenol; polyhydric phenols such as catechol, resorcin, hydroquinone, bisphenol A, bisphenol S, bisphenol F, and pyrogallol.

  Among these, “alkyl group-substituted phenol substituted with a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms” is preferable, and “alkyl substituted with a linear or branched alkyl group having 4 to 12 carbon atoms”. “Group-substituted phenols” are particularly preferred. Specifically, for example, p-cresol, m-cresol, p-propylphenol, p-tert-butylphenol (PTBP), p-amylphenol, p-cyclohexylphenol, p-octylphenol (POP), p-nonylphenol ( PNP), p-decylphenol (PDP), p-dodecylphenol (PDDP) and the like are preferable. These may be used alone or in a mixture of two or more for the condensation reaction to obtain a condensate. Hereinafter, the corresponding phenols may be indicated by the above-mentioned symbols in parentheses.

  Among the above specific examples, those using PTBP, POP, PNP, PDP or PDDP are particularly preferable.

1.2. Aldehydes The “aldehydes” are not particularly limited, and examples include formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, acrolein, benzaldehyde, furfural and the like. These may be used alone or in a mixture of two or more for the condensation reaction to obtain a condensate. Particularly preferred is formaldehyde. Formaldehyde is also preferably used for the synthesis of the resin in the form of paraformaldehyde or formalin.

1.3. Condensate The “condensate of phenols and aldehydes” is preferably a resol type phenol resin in order to increase the molecular weight of the rosin-modified phenol resin. As a method for producing a resol type phenol resin, the above phenols and the above aldehydes are heated, reacted in water, in an organic solvent or in bulk (no solvent) in the presence of an alkali catalyst, or the above phenols And the above aldehydes in water, in an organic solvent or in bulk (without solvent) in the presence of an acid catalyst to produce a novolak-type phenol resin first, and then in the presence of the aldehyde and an alkali catalyst. And the like.

  Although the specific manufacturing method of a resol type phenol resin is not specifically limited, it mixes in the ratio of 1.5-3 mol of formaldehyde with respect to 1 mol of phenols, sodium hydroxide, potassium hydroxide, calcium hydroxide, etc. Obtained by polycondensation in the presence of an alkali catalyst. If necessary, it is also preferable to neutralize and / or wash the alkali catalyst after the reaction.

1.4. Rosin Although there is no limitation in particular as said "rosin", natural rosin such as gum rosin, wood rosin, tall oil rosin; polymerized rosin obtained from the natural rosin; obtained by disproportionating the natural rosin or the polymerized rosin Stabilized rosin such as disproportionated rosin, hydrogenated rosin obtained by hydrogenating the natural rosin or polymerized rosin; maleic acid, maleic anhydride, fumaric acid, itaconic acid, croton to the natural rosin or polymerized rosin Examples include unsaturated acid-modified rosins obtained by adding unsaturated carboxylic acids such as acid, cinnamic acid, acrylic acid, and methacrylic acid; and these acid-modified rosins. These may be used alone or in combination of two or more.

1.5. Polyols The “polyols” are not particularly limited. For example, glycerin (hereinafter sometimes abbreviated as “Gly”), trimethylolethane, trimethylolpropane, diglycerin, ditrimethylolethane, ditrimethylolpropane. , Ethoxylated trimethylolpropane, propoxylated trimethylolpropane, neopentyl glycol, pentaerythritol (hereinafter sometimes abbreviated as “PE”), dipentaerythritol, sorbitol, butanediol, 2-methylpentanediol, 1, Examples include aliphatic polyhydric alcohols such as 6-hexanediol, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, and polypropylene glycol. The These may be used alone or in combination of two or more.

1.6. Structure and production method of rosin-modified phenolic resin The chemical structure of the above-mentioned "rosin-modified phenolic resin having a structure obtained by reacting at least a condensate of phenols and aldehydes, rosins and polyols" is complex, Moreover, since it is also a mixture, it cannot be specified by chemical structural formula or chemical name, so it must be specified by the raw material used for the reaction. Therefore, if the produced rosin-modified phenolic resin has the same chemical structure, it is the same substance even if the production method of the rosin-modified phenolic resin is different. However, the manufacturing method of the rosin modified phenolic resin in the present invention is preferably as described below.

  The specific production method of the “rosin-modified phenolic resin” in the present invention is not particularly limited. For example, a preferred production method is to first react rosin with the condensate, and then react the reactant with polyol. Or a method in which a rosin and a polyol are reacted first, and then the reaction product is reacted with the above condensate (hereinafter referred to as “Method B”). Any method can be employed. In addition, when the polyols are reacted, metal compounds such as magnesium salts such as magnesium hydroxide, magnesium carbonate, magnesium bicarbonate, magnesium acetate, magnesium formate, and magnesium oxalate may be present.

  In the above reaction, an acid catalyst can be used as necessary. Examples of such an acid catalyst include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, methanesulfonic acid, ethanesulfonic acid and the like. In order to prevent coloring, a reducing agent such as hypophosphorous acid, triphenyl phosphite, and triphenyl phosphate can be used in combination. In order to accelerate the reaction, it is also preferable to reduce the pressure.

  The specific production method of method A is not particularly limited. For example, rosins are heated and melted at 150 to 250 ° C., and a condensate is dropped and reacted therewith. The method of making it react at -280 degreeC is mentioned. The specific production method of Method B is not particularly limited. For example, rosins and polyols are charged into a reactor and reacted at a temperature of 200 to 280 ° C., and then a condensate is added to the reaction product at 150 to 250 ° C. The method of making it drop-react is mentioned.

  As for each usage-amount, 20-130 mass parts is preferable with respect to 100 mass parts of rosins, and 40-100 mass parts is especially preferable. Moreover, 5-15 mass parts of polyols are preferable with respect to 100 mass parts of rosins. Moreover, it is also preferable to use polyols so that the hydroxyl group of polyols may become 0.5-1.2 equivalent with respect to 1 equivalent of carboxylic acid of rosins. Within this range, it is easy to keep both the softening point of the rosin-modified phenolic resin itself and the two different weight average molecular weights within the preferred range, and the reaction point with the gelling agent is preferred. In the presence of a gelling agent, the rosin-modified phenolic resin can be made to have a high molecular weight and a gel varnish for offset printing ink can be produced.

  The rosin modified phenolic resin in the present invention is obtained by mixing two kinds of rosin modified phenolic resins having different weight average molecular weights. The weight average molecular weight of the rosin modified phenolic resin is the same as the weight average molecular weight of the condensate. Ratio of product to rosin, ratio of rosin to polyol, reaction temperature at each stage, reaction time at each stage, amount of catalyst at each stage, stirring conditions, raw material addition conditions (adjustment of dropping speed, etc.) ) Etc. to adjust.

  In particular, in the case of a high molecular weight rosin modified phenolic resin, which will be described later, in a gel permeation chromatography (GPC) chart, tailing on the high molecular weight side or a shoulder on the high molecular weight side may occur. The molecular weight rosin-modified phenol resin is not particularly limited, but is mainly obtained by reacting for a long time under reduced pressure.

  In addition, the rosin modified phenolic resin in the present invention does not exclude that other components other than the above components are introduced into the resin by a chemical reaction. Other components are added and the reaction operation is performed, and then introduced into the rosin-modified phenolic resin by chemical reaction or left together with the rosin-modified phenolic resin (mixed), softening point, weight average molecular weight, number The average molecular weight, solubility, viscosity, etc. can also be adjusted.

1.6.1. Weight average molecular weight of rosin modified phenolic resin The rosin modified phenolic resin in the present invention is obtained by mixing two kinds of rosin modified phenolic resins having different weight average molecular weights. Three or more types of rosin-modified phenol resins having different weight average molecular weights may be mixed, but at least the rosin-modified phenol resin in the present invention is obtained by mixing two types of high-molecular weight rosin-modified phenol resins and low-molecular weight rosin-modified phenol resins. It is obtained.

  Among them, the weight average molecular weight of the high molecular weight rosin-modified phenol resin is preferably 40,000 or more, more preferably 60,000 or more, particularly preferably 80,000 or more, and further preferably 100,000 or more. If the weight average molecular weight of the high molecular weight rosin modified phenolic resin is too low, the addition of the low molecular weight rosin modified phenolic resin may not improve the misting resistance or the viscosity of the ink may not sufficiently increase. On the other hand, the upper limit of the weight average molecular weight of the high molecular weight rosin-modified phenol resin is not particularly limited, but is preferably 300,000 or less, and particularly preferably 150,000 or less. If the weight average molecular weight of the high molecular weight rosin-modified phenolic resin is too high, the flowability will not improve even if a low molecular weight rosin-modified phenolic resin is added, if the resin itself is difficult to synthesize, or if it is difficult to take out the resin, The solubility during varnishing may be poor.

  The weight average molecular weight of the low molecular weight rosin-modified phenol resin is preferably 30,000 or less, more preferably 25,000 or less, and particularly preferably 20,000 or less. If the weight average molecular weight of the low molecular weight rosin-modified phenolic resin is too high, the fluidity cannot be improved even if it is added to the high molecular weight rosin-modified phenolic resin, or the ink transferability and glossiness may decrease. . On the other hand, the lower limit of the weight average molecular weight of the low molecular weight rosin-modified phenol resin is preferably 5000 or more, more preferably 7000 or more, and particularly preferably 10,000 or more. If the weight average molecular weight of the low molecular weight rosin modified phenolic resin is too low, the addition of the high molecular weight rosin modified phenolic resin will not improve the misting resistance, the ink viscosity will not increase, the softening point will be too low, There are cases where the resin causes blocking.

  The weight average molecular weight of the high molecular weight rosin modified phenolic resin is preferably 1.5 to 30 times, more preferably 2 to 15 times, and particularly preferably 4 to 10 times the weight average molecular weight of the low molecular weight rosin modified phenolic resin. .

  The weight average molecular weight of the rosin-modified phenol resin is obtained as a standard polystyrene equivalent value by gel permeation chromatography (GPC) according to the method described in the examples.

  The mixing ratio of the high molecular weight rosin modified phenolic resin and the low molecular weight rosin modified phenolic resin is 30 to 30% of the total of the high molecular weight rosin modified phenolic resin and the low molecular weight rosin modified phenolic resin. 97 mass% is preferable, 40-95 mass% is more preferable, 50-90 mass% is especially preferable. If the amount of the high molecular weight rosin modified phenolic resin is too large, the fluidity may not be improved sufficiently. On the other hand, if the amount of the high molecular weight rosin modified phenolic resin is too small, the misting resistance may not be improved.

1.6.2. Same or different raw material for rosin modified phenolic resin The rosin modified phenolic resin in the present invention is not prepared by mixing two kinds of high molecular weight rosin modified phenolic resin and low molecular weight rosin modified phenolic resin. When trying to substitute with one kind of rosin-modified phenolic resin obtained in (1), as shown in Comparative Examples 3 to 6, compatibility between misting resistance and heating fluidity is not achieved. In particular, when one type of rosin modified phenolic resin having an intermediate weight average molecular weight is used as in Comparative Example 4, both misting resistance and warming fluidity show completely good results. Absent.

  As described above, the rosin-modified phenol resin in the present invention is obtained by mixing two kinds of rosin-modified phenol resins having different weight average molecular weights. It is essential that the phenols and polyols that are the raw materials of the “resin” are substantially the same as each other. That is, the phenol of the high molecular weight rosin modified phenolic resin and the phenol of the low molecular weight rosin modified phenolic resin are substantially the same, and the polyol of the high molecular weight rosin modified phenolic resin and the polyol of the low molecular weight rosin modified phenolic resin It is essential that the class is substantially identical.

  In order to achieve both misting resistance and fluidity, it may be better to mix two or more resins with different physical properties as much as possible. Conventionally, a completely different resin that is not a rosin-modified phenol resin. (For different purposes, for example, Patent Document 5). Conventionally, the resin composition has not been studied in the first place, and the relationship of the present invention has not been clarified. That is, even when two types of rosin-modified phenolic resins are mixed and used, the phenols and polyols, which are raw materials for the rosin-modified phenolic resin, are not identical to each other.

  As long as both phenols and polyols are identical to each other, it has been considered that the same physical properties can be obtained even if one type of rosin-modified phenol resin is used. That is, it was thought that one kind of rosin modified phenolic resin having a broad molecular weight distribution and one kind of rosin modified phenolic resin for which the synthesis conditions were examined were sufficient. However, when one type of rosin-modified phenol resin is used, it has been found that no matter how it is optimized, the compatibility between misting resistance and fluidity cannot be achieved. In other words, this means that “a suitable rosin-modified phenol resin that achieves both misting resistance and fluidity” obtained by mixing a high-molecular-weight rosin-modified phenol resin and a low-molecular-weight rosin-modified phenol resin is at least as of the present time. It is shown that a known synthesis technique cannot be obtained as one kind of rosin-modified phenol resin obtained by one synthesis.

  Furthermore, when one of the phenols and polyols is different, surprisingly, both misting resistance and warming fluidity can be achieved even when two types of rosin-modified phenol resins are used in combination. It turns out not to be. On the contrary, as shown in Comparative Example 1 and Comparative Example 2, it was found that both misting resistance and warming fluidity showed poor results.

  Furthermore, in the high molecular weight rosin modified phenolic resin and the low molecular weight rosin modified phenolic resin, it is particularly preferable that the “molar ratio of phenols and polyols” used for the respective resin synthesis is substantially the same. Not only is the raw material type the same, but the compounding ratio of the respective phenols and polyols during the resin synthesis is substantially the same, and the composition ratio of the phenols and polyols in the synthesized rosin-modified phenol resin is substantially the same. In other words, the above-mentioned “high fluidity of ink” and “low misting amount”, which are in a trade-off relationship, can be achieved more remarkably.

  When the phenols and / or polyols are a mixture of two or more, the total amount of each is used for the calculation of the “molar ratio”. That is, a particularly preferred embodiment of the present invention is offset printing in which the molar ratio of phenols and polyols, which are raw materials for rosin-modified phenolic resins, is substantially equal to each other in the two types of rosin-modified phenolic resins having different weight average molecular weights. Ink varnish.

  If the "molar ratio of phenols and polyols" used for each resin synthesis is substantially the same, it is usually considered that one rosin-modified phenol resin having a broad molecular weight distribution is sufficient. However, when one kind of rosin-modified phenolic resin (manufactured by one synthesis) is used, no matter how it is optimized, both misting resistance and fluidity as in the present invention cannot be achieved. I understood that.

  Specifically, as the phenols, those using PTBP, POP, PNP, PDP or PDDP are preferred for both the high molecular weight rosin modified phenolic resin and the low molecular weight rosin modified phenolic resin. Further, as the polyols, specifically, those using the above-described specific examples are both preferable.

  Furthermore, the aldehydes and / or rosins are preferably the same in both the high molecular weight rosin modified phenolic resin and the low molecular weight rosin modified phenolic resin. That is, it is particularly preferred that phenols, aldehydes, rosins and polyols are all the same in both resins. Both aldehydes are preferably formaldehyde. Formaldehyde is preferably used for resin synthesis in the form of paraformaldehyde or formalin. The rosins are preferably those using the specific examples described above for both the high molecular weight rosin modified phenolic resin and the low molecular weight rosin modified phenolic resin.

  When two or more types of phenols and / or two or more types of polyols are co-condensed in one type of high molecular weight rosin modified phenolic resin or in one type of low molecular weight rosin modified phenolic resin In the present invention, all of the co-condensed phenols and / or polyols are completely identical between the two types (high molecular weight and low molecular weight) of rosin-modified phenolic resins. The ratio of two or more types of phenols and / or two or more types of polyols is substantially the same between the two types (high molecular weight and low molecular weight) of rosin-modified phenol resins.

  When two or more rosins and / or two or more aldehydes are used in one kind of high molecular weight rosin modified phenolic resin or in one kind of low molecular weight rosin modified phenolic resin, In the present invention, it is preferable that all rosins or aldehydes are the same between two types of rosin-modified phenolic resins (high molecular weight and low molecular weight). The content ratio is preferably the same as described above.

1.7. Properties of rosin-modified phenolic resin, etc. The softening point of the rosin-modified phenolic resin obtained by mixing two types of rosin-modified phenolic resins is preferably 70 to 150 ° C, more preferably 80 to 120 ° C. It is especially preferable that it is 100-120 degreeC. If the softening point is too low or too high, printability may be reduced.

  Since the gelling agent described later acts on carboxyl groups derived from rosins chemically bonded to rosin-modified phenol resins, hydroxyl groups derived from polyols chemically bonded to rosin-modified phenol resins, rosin-modified phenol resins are gels. It is easy to increase the molecular weight by the agent.

2. Substances other than rosin-modified phenolic resin contained in varnish for offset printing ink The varnish for offset printing ink of the present invention preferably contains vegetable oil and / or a solvent in addition to the above-mentioned two types of rosin-modified phenolic resins. . In addition to the above-mentioned two types of rosin-modified phenolic resins, “other resins” can be contained.

2.1. Vegetable oil “Vegetable oil” is a triglyceride of glycerin and a fatty acid, wherein at least one fatty acid is a fatty acid having at least one carbon-carbon unsaturated bond. Examples of such vegetable oils include asia seed oil (149 or more), eno oil (192 or more), jute oil (140 or more), kapok oil (85 to 102), kaya oil (130 or more), olive oil, cacao oil, coconut oil, Mustard oil (over 101), Kyonin oil (97-109), Tung oil (over 145), kukui oil (over 136), walnut oil (over 143), poppy oil (over 131), sesame oil (over 104), safflower Oil (130 or more), Japanese radish seed oil (98 to 112), soybean oil (117 or more), daifu oil (101), camellia oil, castor oil, tall oil, canola oil, corn oil (109 or more), rapeseed oil ( 97-107), niger oil (126 or more), nuka oil (92-115), sunflower oil (125 or more), grape seed oil (124 or more), gentian oil (93-105) Pine seed oil (146 or more), cottonseed oil (99 to 113), peanut oil (84 to 102), castor oil, dehydrated castor oil (147 or more), thermopolymerized oil, deer oil (140 or more), Chinese tung oil (190 or more) ), Linseed oil (180 or more), polymerized linseed oil, corn oil, canol oil, cinnabar oil and the like are preferably used. These vegetable oils may be used alone or in combination of two or more.

  Among them, semi-drying oils such as soybean oil, rapeseed oil and corn oil; dry oils such as linseed oil, tung oil, safflower oil, cinnabar oil, sesame oil; non-drying oils such as castor oil, olive oil, coconut oil; dehydrated castor oil, Synthetic oils such as thermopolymerized oils and regenerated oils are more preferred, soybean oil, coconut oil, linseed oil, rapeseed oil and the like are particularly preferred, and soybean oil is most preferred.

  The iodine value of the vegetable oil to be used is not particularly limited, but is preferably 100 or more from the viewpoint that the drying property by oxidative polymerization can be further improved. In the parentheses, the iodine value is shown.

2.2. Solvent As the “solvent”, a paraffinic, naphthenic (cycloparaffinic), aroma (aromatic) solvent, or a mixture thereof is used, but preferably contains an aroma (aromatic) solvent. A “low aromatic solvent” having a rate of 1% by mass or less is used.

  The non-aromatic solvent is also called an aromaless solvent (aroma-free solvent), and specifically, for example, AF Solvent No. 4, AF Solvent No. 5, AF Solvent No. 6, AF Solvent No. 6 manufactured by Nippon Oil Corporation Solvent No. 7, No. 0 Solvent H, etc .; Supersol LA35, LA38, etc. manufactured by Idemitsu Kosan Co., Ltd .; Exol D80, D110, D120, D130, D160, D100K, D120K, D130K, etc. manufactured by Exxon Chemical Co., Ltd .; Examples include D-SOL280 and D-SOL300 manufactured by Juki Chemical; Magie Sol-40, 44, 47, 52, and 60 manufactured by Maggie Brothers. These can be mixed and used at an arbitrary mass ratio. Moreover, it is not limited to these commercially available products.

2.3. Other resin The “other resin” contained in the varnish for offset printing ink of the present invention is not particularly limited. For example, “obtained by mixing the above-described high molecular weight rosin-modified phenol resin and low molecular weight rosin-modified phenol resin. Rosin modified phenolic resin (third type rosin modified phenolic resin) other than rosin modified phenolic resin, rosin polyester resin, maleated rosin, alkyd resin, rosin modified alkyd resin, gilsonite resin, petroleum resin, hydrocarbon resin, Examples include acid-modified hydrocarbon resins.

Among the “other resins”, “rosin-based polyester resin” refers to a resin obtained by reacting all of the following (1) to (5).
(1) Rosin and polymerized rosin (2) Petroleum hydrocarbon resin (3) Unsaturated carboxylic acid or unsaturated carboxylic acid anhydride (4) Polyhydric alcohol (5) Fatty acid or aliphatic monoalcohol Kind

  Content of “rosin-modified phenol resin obtained by mixing high molecular weight rosin-modified phenol resin and low molecular weight rosin-modified phenol resin” in the entire resin contained in the varnish for offset printing ink of the present invention is 50% by mass or more. Is preferable, 75 mass% or more is more preferable, and 100 mass% is particularly preferable.

  “Varnish for offset printing ink using one type of rosin-modified phenolic resin” and “One type of other rosin-modified phenolic resin in which either the raw material phenols or polyols are not substantially the same are used. Even when the varnish for offset printing ink is mixed at the varnish stage (once varnish once), the rosin-modified phenolic resins are also mixed at the same time when the varnishes are mixed. Therefore, such “mixed varnish” is also included in the varnish for offset printing ink of the present invention.

3. Gel varnish for offset printing ink The varnish for offset printing ink of the present invention is heated together with a gelling agent and used for producing offset printing ink as a gel varnish for offset printing ink.

  A “gelling agent” refers to a compound that increases the molecular weight of a rosin-modified phenol resin by heating. It acts on the carboxyl group of the rosins bonded to the rosin-modified phenolic resin, the hydroxyl group of the polyols bonded to the rosin-modified phenolic resin, and the like to increase the molecular weight.

The gelling agent is not particularly limited, but an aluminum complex compound is preferable. As an aluminum complex compound, for example,
Cyclic aluminum compounds such as cyclic aluminum oxide octate (Algormer 800 manufactured by Kawaken Fine Chemical Co., Ltd.) and cyclic aluminum oxide stearate (Algomer 1000S manufactured by Kawaken Fine Chemical Co., Ltd.);
Aluminum alcoholates such as aluminum ethylate, aluminum isopropylate (AIPD manufactured by Kawaken Fine Chemical Co., Ltd.), aluminum-sec-butyrate (ASPD manufactured by Kawaken Fine Chemical Co., Ltd.), aluminum isopropylate-mono sec-butylate (AMD manufactured by Kawaken Fine Chemical Co., Ltd.) Kind;
Aluminum-di-n-butoxide-ethyl acetoacetate (Cheope-Al-EB2 from Hope Pharmaceutical), aluminum-iso-butoxide-methyl acetoacetate (Chelope-Al-MB12 from Hope Pharmaceutical), aluminum-iso-butoxide-ethyl Acetoacetate (Chelope-Al-EB102 manufactured by Hope Pharmaceutical), Aluminum-diiso-butoxide-ethylacetoacetate (Chelope-Al-EB2 manufactured by Hope Pharmaceutical), Aluminum-diiso-propoxide-ethylacetoacetate (Chelope manufactured by Hope Pharmaceutical Co., Ltd.) -Al-EP12, ALCH manufactured by Kawaken Fine Chemical Co., Ltd., ALCH-50F manufactured by Kawaken Fine Chemical Co., Ltd.), Aluminum-Tris (acetylacetonate) (Kawaken Fu ALCH-TR manufactured by Inchemical Co., Ltd., aluminum-tris (acetylacetoacetate) (aluminum chelate A manufactured by Kawaken Fine Chemical Co., Ltd.), aluminum bis (ethylacetylacetonate) monoacetylacetonate (aluminum manufactured by Kawaken Fine Chemical Co., Ltd.) Aluminum alkyl acetoacetates such as chelates D);
Aluminum chelate M (manufactured by Kawaken Fine Chemical Co., Ltd.), aluminum chelate NB-15 (manufactured by Hope Pharmaceutical Co., Ltd.), Kerope S (manufactured by Hope Pharmaceutical Co., Ltd.), Kerope ACS-2 (manufactured by Hope Pharmaceutical Co., Ltd., liquid Oleop AOO (manufactured by Hope Pharmaceutical Co., Ltd.)) , Liquid Olipe AOS (Hope Pharmaceutical);
Aluminum soaps such as aluminum stearate (manufactured by NOF Corporation), aluminum oleate, aluminum naphthonate, aluminum urate, aluminum acetylacetonate;
Etc.

  Furthermore, organic titanates such as tetraisopropyl titanate, tetra-n-butyl titanate, tetrooctyl titanate, titanium acetylacetonate, titanium octylene glycolate, titanium lactate, titanium lactate ethyl ester; zirconium-tetrabutoxide, zirconium acetylacetone, acetylacetone zirconium butoxide And organic zirconium such as ethyl zirconium butoxide of acetoacetate.

  Other gelling agents include: cyclic dipeptides; bisamides such as ethylene bis (12-hydroxyoctadecanoic acid) amide; Al-Mg-hydroxycaprylate, Al-Mg-hydroxymyristate, Al-Mg-hydroxy Examples thereof include aluminum-magnesium compounds such as palmitate and Al-Mg-hydroxybehenate.

  The gelling agent is preferably used in the range of 0.1 to 10 parts by weight and used in the range of 0.3 to 6 parts by weight with respect to 100 parts by weight of the varnish for offset printing ink. It is more preferable to use in the range of 1 to 4 parts by mass. If the amount of the gelling agent is too small, the molecular weight cannot be increased, and the effects of the present invention described above may not be obtained. On the other hand, if the amount is too large, gelation may proceed.

  The above-mentioned “solvent and / or vegetable oil that is preferably contained in the varnish for offset printing ink of the present invention” can be additionally blended when preparing the gel varnish.

4). Offset printing ink An offset printing ink is prepared by adding at least a colorant to the gel varnish for offset printing ink. In addition, to the gel varnish for offset printing ink, an offset printing ink is prepared by further adding the above-mentioned solvent, blending the above-described vegetable oil or fatty acid ester, or blending other additives described below. You can also.

4.1. Colorant Examples of the colorant include pigments, and examples thereof include inorganic pigments and organic pigments including extender pigments. Examples of the inorganic pigment include chrome yellow, zinc yellow, bitumen, barium sulfate, cadmium red, titanium oxide, zinc white, dial, alumina white, calcium carbonate, ultramarine, carbon black, graphite, aluminum powder, and bengara. Examples of organic pigments include soluble azo pigments such as β-naphthol, β-oxynaphthoic acid, β-oxynaphthoic acid anilide, acetoacetanilide, pyrazolone, and the like; β-naphthol, β-oxynaphtho Insoluble azo pigments such as acid anilide, acetoacetanilide monoazo, acetoacetanilide disazo, pyrazolone, etc .; copper phthalocyanine blue, halogenated (chlorine or brominated) copper phthalocyanine blue, sulfonated copper phthalocyanine blue, metal-free phthalocyanine Phthalocyanine pigments such as: quinacridone, dioxazine, selenium (pyrantron, anthanthrone, indanthrone, anthrapyrimidine, flavantron, thioindigo, anthraquinone, perinone, perylene, etc.), isoindolinone, metal Examples include complex-type and quinophthalone-type polycyclic pigments and heterocyclic pigments.

4.2. Other additives Furthermore, other additives can be used in the offset printing ink as required. For example, as anti-friction agents, anti-blocking agents, slip agents, and anti-scratch agents, natural waxes such as carnauba wax, wax, lanolin, montan wax, paraffin wax, microcrystalline wax, etc .; Fischer Trops wax, polyethylene wax, polypropylene Examples thereof include synthetic waxes such as wax, polytetrafluoroethylene wax, polyamide wax, and silicone compound.

  The solvent in the offset printing ink is preferably used in the range of 50 to 300 parts by mass, and in the range of 80 to 200 parts by mass with respect to 100 parts by mass of the rosin-modified phenolic resin. It is particularly preferable. If the amount of the solvent is too small, the rosin-modified phenolic resin may be difficult to dissolve, while if it is too much, the printability such as glossiness and drying property may be deteriorated.

  The vegetable oil in the offset printing ink is preferably used in an amount of 100 parts by mass or less, more preferably in the range of 20 parts by mass to 100 parts by mass with respect to 100 parts by mass of the rosin-modified phenolic resin. , Particularly preferably in the range of 25 to 80 parts by weight. When there is too little vegetable oil, it may become high viscosity and it will become easy to produce the trouble at the time of manufacture, on the other hand, when too much, dryness may worsen.

4.3. Method for producing offset printing ink The method for producing offset printing ink is not particularly limited, but preferably between room temperature and 100 ° C., gel varnish for offset printing ink, colorant, and if necessary, solvent, vegetable oil, fatty acid ester , “Other additives” and the like are blended and manufactured using a kneader, three rolls, attritor, sand mill, gate mixer, and the like.

  The offset printing ink obtained using the varnish for offset printing ink of the present invention is applied to offset printing using fountain solution, and preferably applied to high-speed offset printing. It also applies to waterless lithographic printing.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples unless it exceeds the gist. Hereinafter, “part” means “part by mass”.

Example 1
<Preparation of varnish for offset printing ink>
It has a structure obtained by reacting a condensate of p-octylphenol (POP) with formaldehyde, monomer rosin (gum rosin) and pentaerythritol (PE) at POP: PE = 10: 1 (molar ratio), 20 parts of rosin-modified phenolic resin having a weight average molecular weight of 140,000, having the same chemical structure (phenols, aldehydes, rosins and polyols are all specifically the same, and phenols and polyols The same as the blending molar ratio), 20 parts of rosin-modified phenol resin having a weight average molecular weight of 20,000, 10 parts of soybean white oil, which is a kind of soybean oil, were added to 50 parts of AF solvent No. 7 which is a nonpolar solvent. It was made to melt | dissolve in 30 degreeC over 30 minutes, and the varnish for offset printing inks was obtained.

<Preparation of gel varnish for offset printing ink>
The above varnish for offset printing ink is cooled to 120 ° C., 1.5 parts of “ALCH-50F” (manufactured by Kawaken Fine Chemical Co., Ltd.), which is an aluminum ethyl acetoacetate gelling agent, is added, and 60 ° C. at 60 ° C. Gelation reaction was performed over a period of time to obtain a gel varnish for offset printing ink.

<Preparation of offset printing ink>
60 parts of the gel varnish for offset printing ink and 17 parts of “Kermin 6B” as a colorant were dispersed using a three-roll mill. The resulting dispersion was adjusted to a total of 100 parts using an AF solvent No. 7 as a solvent and the above gel varnish and adjusted to an ink tack of 6.3 to 6.5, and offset printing ink. Got.

  In this way, a varnish for offset printing ink was prepared by mixing a high molecular weight rosin modified phenolic resin, which is considered to have good misting resistance, and a low molecular weight rosin modified phenolic resin, which is considered to have good warming fluidity, Using it, an offset printing ink was obtained.

Example 2, Comparative Examples 1-6
In Example 1, the phenols and polyols were replaced as shown in Table 1, and the molar ratio (mass ratio) of the phenols and polyols compounded during the synthesis of the resin was the same to synthesize a rosin-modified phenol resin. In addition, 40 parts of the rosin-modified phenolic resin (in the case of using two types of rosin-modified phenolic resins, the total is 40 parts), except for using alone or in combination as shown in Table 2. As in Example 1, a varnish for offset printing ink was obtained.

  Using the varnish for offset printing ink, a gel varnish for offset printing ink was obtained in the same manner as in Example 1, and further using this, an offset printing ink was obtained in the same manner as in Example 1.

  As described above, Example 2 has a high molecular weight rosin modified phenolic resin which has a similar chemical structure and is considered to have good misting resistance, and a low molecular weight rosin modified phenol which is considered to have good warming fluidity. A varnish for offset printing ink was prepared by mixing with a resin, and an offset printing ink was obtained using the varnish.

  As described above, Comparative Example 1 and Comparative Example 2 have different chemical structures (both phenols and polyols are different), and high molecular weight rosin modified phenolic resin that is considered to have good misting resistance. The varnish for offset printing ink was prepared by mixing with low molecular weight rosin modified phenolic resin which is considered to have good warming fluidity, and an offset printing ink was obtained using it.

  As described above, in Comparative Example 3 and Comparative Example 6, a varnish for offset printing ink was prepared by using a low molecular weight rosin modified phenolic resin, which is considered to have good warming fluidity, and offset printing was performed using the varnish. An ink was obtained.

  As described above, Comparative Example 4 has a weight average molecular weight (72,000) intermediate between the weight average molecular weight considered to have good misting resistance and the weight average molecular weight considered to have good warming fluidity. A varnish for offset printing ink was prepared using rosin-modified phenol resin alone, and an offset printing ink was obtained using the varnish.

  As described above, in Comparative Example 5, a varnish for offset printing ink was prepared by using a high molecular weight rosin-modified phenolic resin considered to have good misting resistance, and an offset printing ink was obtained using the varnish.

Evaluation example <weight average molecular weight>
Using an HLC-8220 manufactured by Tosoh Corporation equipped with an RI detector, the developing solvent was THF, the molecular weight standard polymer was standard polystyrene, and GPC was measured to determine the weight average molecular weight.

<Viscosity>
“Testing method of newspaper offset rotary ink” Group standard: 2000 (printing ink industry association / newspaper ink association) “4.1.3 Method using L-type viscometer”, viscosity of offset printing ink was measured .

<Tack>
“Test method for newspaper offset rotary ink” Group standard: 2000 (printing ink industry association / newspaper ink association) “4.2 Adhesiveness”, offset printing ink 1.31mL made by Toyo Seiki Co., Ltd. The tack value was measured immediately after rotating on an incometer at a room temperature of 25 ° C. and rotating the roll of the incometer at 32 ° C. and a roll rotation speed of 1200 rpm for 30 seconds.

<Missing resistance>
An incometer (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was charged with 2.62 mL of offset printing ink, rotated at 2000 rpm at 40 ° C. for 2 minutes, and visually observed the amount of scattering on the standard paper placed under the roll. The amount of scattering was evaluated in the following three stages.
1: A lot of misting 2: A little misting 3: Little misting

<Heating fluidity>
50 g of offset printing ink was taken in a cup, allowed to stand in a thermostatic box at 50 ° C. for 3 hours and then overturned, and the fluidity after 5 minutes was visually observed. The evaluation of warming fluidity was performed in the following three stages. The “fluidity” in the specification was evaluated by this representative “warming fluidity” in Examples.
1: Not flowing at all 2: Slightly flowing 3: Flowing

表１中の記号は以下の通りである。
ＰＯＰ ：ｐ−オクチルフェノール
ＰＮＰ ：ｐ−ノニルフェノール
ＰＴＢＰ：ｐ−ｔｅｒｔ−ブチルフェノール
ＰＥ ：ペンタエリスリトール
Ｇｌｙ ：グリセリン

The symbols in Table 1 are as follows.
POP: p-octylphenol PNP: p-nonylphenol PTBP: p-tert-butylphenol PE: pentaerythritol Gly: glycerin

<Evaluation results>

  Example 1 and Example 2 are a mixture of two types of rosin-modified phenolic resins having the same weights and different weight average molecular weights in the rosin-modified phenolic resin constituting the offset printing ink varnish. Therefore, when the tack was kept constant, both misting resistance and warming fluidity were excellent and well balanced.

  On the other hand, Comparative Examples 3, 5, and 6 use only one type of rosin-modified phenolic resin having high molecular weight (Comparative Example 5) or low molecular weight (Comparative 3 or 6). Either the misting resistance or the heating fluidity was inferior. In addition, when one kind of rosin modified phenolic resin having an intermediate weight average molecular weight was used as in Comparative Example 4, both the misting resistance and the warming fluidity showed completely good results. There wasn't.

  Comparative Examples 1 and 2 are both a mixture of two types of rosin-modified phenolic resins with high and low molecular weights, but since phenols and polyols are different, compatibility between misting resistance and warming fluidity is achieved. It turns out not to be.

  On the contrary, Comparative Examples 1 and 2 showed poor results in both misting resistance and warming fluidity. That is, as the results of Comparative Example 1 and Comparative Example 2 show, the high molecular weight rosin modified phenolic resin of Comparative Example 5 is different from the low molecular weight rosin modified phenolic resin in which phenols and polyols are different (in Comparative Example 1, resin Q, comparison In Example 1, even when the resin R) was mixed, the heating fluidity was not improved at all from Comparative Example 5.

  Therefore, as shown in Example 1 and Example 2, phenols, aldehydes, rosins and polyols are all the same, at least the phenols and polyols are the same, and two types having different weight average molecular weights. Only when the rosin-modified phenol resin was mixed, an offset printing ink excellent in both misting resistance and warming fluidity was obtained when the tack was kept constant.

  The offset printing ink containing the gel varnish formed by gelling the varnish for offset printing ink of the present invention is excellent in both misting resistance and fluidity, and therefore widely used in all offset printing fields including high-speed offset printing. It is what is used.

Claims (7)

  At least a varnish for offset printing ink containing a rosin-modified phenol resin having a structure obtained by reacting a condensate of phenols and aldehydes, a rosin and a polyol, the rosin-modified phenol resin being different Which is obtained by mixing two types of rosin-modified phenolic resins having a weight average molecular weight and which is a raw material for the two types of rosin-modified phenolic resins having different weight average molecular weights? Varnishes for offset printing inks, characterized in that they are substantially identical to each other.   The rosin-modified phenolic resin is obtained by mixing a high-molecular-weight rosin-modified phenolic resin having a weight average molecular weight of 40,000 or more and a low-molecular weight rosin-modified phenolic resin having a weight average molecular weight of 30,000 or less. Varnish for offset printing ink.   Furthermore, the molar ratio of phenols and polyols, which are raw materials for rosin-modified phenolic resins, is substantially equal to each other in the two types of rosin-modified phenolic resins having different weight average molecular weights. Varnish for offset printing ink.   The varnish for offset printing ink according to any one of claims 1 to 3, further comprising vegetable oil.   A gel varnish for offset printing ink, which is obtained by gelling the varnish for offset printing ink according to any one of claims 1 to 4 together with a gelling agent.   An offset printing ink comprising the gel varnish for offset printing ink according to claim 5 and a colorant.   A printed matter obtained by printing the offset printing ink according to claim 6 on a substrate.