JPH04168168A - Varnish for lithographic ink and lithographic ink composition using the same - Google Patents

Abstract

PURPOSE:To provide the subject varnish satisfied with a high luster and an ink quick-drying property and having largely improved suitability by adding a crosslinking agent to a mixture of a high boiling point petroleum solvent and a binder resin. CONSTITUTION:The objective varnish having excellent printing suitability and drying suitability comprises (A) a mixture of (i) a high boiling point petroleum solvent such as a petroleum fraction having a boiling point of 220-350 deg.C and (ii) a binder resin preferably containing either of a phenolic resin, an alkyd resin and a rosin ester resin as an essential component, and (B) a crosslinking agent preferably comprising an aziridine compound such as isophorone diisocyanate, a polyisocyanate compound and/or an epoxy compound, the component ii being crosslinked with the crosslinking agent B. The crosslinking agent is preferably added in an amount of 0.001-1.00wt.%.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a lithographic printing ink varnish and a lithographic printing ink composition using the same. The purpose of the present invention is to provide a varnish for lithographic printing ink that is excellent in terms of lithographic printing ink.

<Conventional technology> Traditionally, the inks used in lithographic printing include pigments, which are colorants for boat fishing, rosin-modified phenolic resin,
It is mainly composed of a varnish made by dissolving a binder resin, typically an alkyd resin, in a drying or semi-drying oil such as linseed oil, tung oil, or safflower oil, and adding a high-boiling petroleum solvent to the mixture. .

In the field of lithographic printing, there has been a strong demand for high printing quality such as gloss, improved printing speed such as quick drying of ink, improved printing workability such as underwater suitability, and improved working environment.

However, with conventional lithographic printing inks made from varnish, it is difficult to simultaneously satisfy printing quality such as gloss and quick drying of the ink. For example, if an ink is designed to improve gloss, it will set slowly. However, problems such as set-off and blocking occur, and conversely, when designed to improve drying properties, printed matter with sufficient gloss cannot be obtained, and various improvements have been made.

For example, when improving the drying properties of ink,
A method has been proposed in which a solvent with a low content of aromatic hydrocarbons is used as a high boiling point petroleum solvent for varnish.

When these solvents are used, they have excellent solvent release from the printed ink film, so
It is possible to improve ink setting and drying properties, and is also desirable from the viewpoint of improving air pollution and working environment.

However, the use of these solvents with a low aromatic hydrocarbon content lowers the solubility of the binder resin, which poses the problem of lowering the printing quality such as the gloss of the ink.

On the other hand, printing workability such as underwater suitability is extremely important in lithographic printing that uses dampening water. This causes problems such as piling.

It is said that one of the causes of the lithographic printing suitability that occurs in connection with dampening water is the presence of polar groups such as carboxyl groups and hydroxyl groups present in the binder resin used, for example, a rosin-modified phenol resin.

In order to solve this problem, attempts have been made to add special activators, glycol solvents, etc., but these methods are still not satisfactory.

<Problems to be Solved by the Invention> Therefore, the present invention aims to solve the above-mentioned conventional problems, and aims to satisfy high gloss and quick-drying ink, and also significantly improve underwater suitability. The object of the present invention is to provide a varnish for lithographic printing ink that can be used.

As a result of repeated research on binder resins for printing ink varnishes, the present inventors have discovered that the presence of low molecular weight resins and polar groups in varnishes improves solvent release performance (solvent removal performance). The present invention was completed after discovering that the above-mentioned problems were significantly improved when the low molecular weight resin was cross-linked by adding a specific amount of cross-linking agent. This is what I came to do.

That is, the present invention provides a lithographic printing ink varnish mainly composed of a high boiling point petroleum solvent and a binder resin, which is characterized in that a crosslinking agent is further added to crosslink the binder resin. This is what we are trying to provide.

The present invention also provides a lithographic printing ink composition using the above varnish.

Hereinafter, regarding the lithographic printing ink varnish according to the present invention,
Explain in detail.

First, the binder resins used in the lithographic printing ink varnish according to the present invention include phenolic resins, phenolic resins such as rosin-modified phenolic resins, alkyd resins,
Alkyd resins such as oil-modified alkyd resins, rosin ester resins such as pentaerythritol esters of various rosins or polymerized rosins can be used.

In addition, as a high boiling point petroleum solvent, as a solvent for lithographic printing ink, - Boiling point 220-35 used for boat fishing
Petroleum fractions in the range of 0°C, as well as spindle oil, machine oil, cylinder oil, etc. can be used.

In addition, important crosslinking agents for obtaining the varnish according to the present invention include trimethylolpropane-tris-β-N-aziridinylpropionate, pentaerythritrolpropane-tris-β-N-aziridinyl Aziridine compounds such as propionate, inphorone diisocyanate,
Polyisocyanate compounds such as hexamethylene diisocyanate and tetramethylene xylylene diisocyanate, and further epoxy compounds such as glycerol polyglycidyl ether and trimethylolpropane polyglycidyl ether can be used.

The amount of these compounds added to the printing ink varnish can be in the range of 0.001 to 1.00% by weight based on the varnish. If the amount of the crosslinking agent added is less than the above range, there is a problem that the reaction with the polar groups in the binder resin is insufficient and the desired effect of the present invention cannot be obtained. This leads to the problem that the solubility of the resin is reduced excessively.

Vegetable oils to be used in combination as necessary include drying or semi-drying oils such as conventionally used linseed oil, safflower oil, tung oil, soybean oil, dehydrated castor oil, and sesame oil, as well as their polymers and modified oils. Things can be used.

For each of these components, binder resin 5
~60% by weight, a high boiling point petroleum solvent from 20 to 70% by weight, and a vegetable oil from 0 to 20% by weight.

The lithographic printing ink varnish according to the present invention is composed of the above-mentioned components, and in addition to these, other binder resins include maleic acid resin, rosin-modified maleic acid resin, petroleum resin, modified petroleum resin, and ring resin. Various esters such as tetrabutoxy titanate as a catalyst, dibutyl phthalate, dioctyl phthalate, tributyl phosphate, and dibutyl sebacate as plasticizers can be added and mixed as necessary.

In addition, when manufacturing a varnish composed of the above components, each material such as a binder resin is heated and dissolved in a high boiling point petroleum solvent to obtain the varnish, and a gelling agent is further added. By heating and reacting, a so-called gel varnish can be obtained.

Regarding the crosslinking agent, it is necessary to selectively cause the resin having a polar group in the low molecular weight resin to undergo a crosslinking reaction, and simultaneously block the polar groups and increase the molecular weight of the low molecular weight resin by crosslinking. If the binder resin is a liquid resin, it is sufficient to add and mix a crosslinking agent from the beginning and allow the crosslinking reaction to occur in a temperature range where the resin dissolves in the solvent. It is preferable to complete the desired crosslinking reaction by adding and mixing a crosslinking agent or adding it at a temperature range where a low molecular weight resin dissolves, that is, a temperature range of 70 to 170°C.

Note that if the crosslinking agent is added at a higher temperature, for example, 180° C. or higher, which is the temperature at which most of the binder resin is heated and dissolved, a crosslinking reaction may occur even in the high molecular weight resin portion. As a result, a problem arises in that the solubility of the resin is lowered more than necessary.

When producing an ink composition for lithographic printing using the varnish obtained in this way, coloring agents such as various organic and inorganic pigments and dyes conventionally used in lithographic inks are added. , can be produced using conventional dispersion and kneading equipment.

In addition, when manufacturing ink, the following various additives can be added as necessary.For example, various waxes, pigment dispersants, drying regulators such as dryers, viscosity regulators, and other known additives are used. can.

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these.

〈Example〉 -1 Riten mackerel L In a 4-tube flask equipped with a condenser, stirrer, and thermometer, 168 parts of a high-boiling point petroleum solvent (No. 6 solvent, manufactured by Nippon Petrochemicals) and a rosin-modified phenolic resin (
172 parts of Tespol 1310 (manufactured by Hitachi Chemical Polymers Co., Ltd.) and 60 parts of linseed oil were added, heated and stirred until the temperature reached 150°C, then 1.6 parts of inphorone diisoanate was added, and the mixture was kept stirring for 10 minutes. Furthermore, the mixture was heated to 200° C. and kept under stirring for 40 minutes to perform baking, thereby obtaining Varnish 1.

In addition, 382 parts of Varnish 1 was charged into another 4-hour flask equipped with a condenser, stirrer, and thermometer.
The temperature was raised to 0°C, and a premix of 6 parts of aluminum chelate (aluminum isopropoxide monoacetyl acetate, manufactured by Shoulder Strap Fine Chemicals) and 12 parts of No. 6 solvent was added as a gelling agent. The gel varnish 1 for single-fed ink was obtained by stirring and holding at C for 60 minutes.

2sannoffi Varnish production example 1 using the equipment used in varnish production example 1
The crosslinking agent is an aziridine compound (Chemitite PZ-33,
Varnish 2 and gel varnish 2 for sheet-fed ink were obtained using the same amount of preparation and operation method, except that the amount was changed to 1.2 parts (manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd.).

Susanoffi Varnish production example 1 using the equipment used in varnish production example 1
The crosslinking agent is an epoxy compound (Bunacol EX-314,
Varnish 3 and gel varnish 3 for sheet-fed ink were obtained using the same amount of preparation and operation method, except that the amount was changed to 1.2 parts (manufactured by Nagase Chemical Industries, Ltd.).

Using the equipment used in Ewanis Production Example 1, add 140 parts of a high-boiling petroleum solvent (No. 6 Solvent), 200 parts of rosin-modified phenolic resin (Tespol 1310>), and 60 parts of linseed oil. After heating and stirring until the temperature reached 150°C, 1.6 parts of inphoron diisoanate was added, and 10
Stirring was maintained for a minute. Furthermore, varnish 4 was obtained by heating to 200°C and stirring and holding for 40 minutes.

Varnish Production Example 5 Using the equipment used in Varnish Production Example 1, naphthenic ink solvent (EFSOL D-110, manufactured by Exxon Chemical Co., Ltd.) 1
88 parts, rosin-modified phenolic resin of varnish production example 1,
After heating and stirring to 150°C, add 1.6 parts of isophorone diisocyanate, keep stirring for 10 minutes, further heat to 200°C, keep stirring for 40 minutes, and crack. Varnish 5 was obtained.

In addition, varnish 5 was added to the apparatus used in varnish production example 1.
Pour 82 parts, raise the temperature to 130°C, and use it as a gelling agent.
The aforementioned aluminum chelate, 6 parts and Fsol D-110, 1
A mixture of 2 parts was added thereto and stirred and held at 180° C. for 60 minutes to obtain heat-setting gel varnish 5.

7j Yumiotsu ILL box J- Varnish production example 5 using the equipment used in varnish production example 1
Varnish 6 and
Gel varnish 6 for heat setting was obtained.

Varnish production example 7 Using the equipment used in varnish production example 1, varnish production example 5
Varnish 7 and heat-setting gel varnish 7 were obtained using the same amount of preparation and procedure except that the crosslinking agent was changed to 1 or 2 parts of Bunacol EX-314.

Using the equipment used in varnish production example 1, Fsol D-
110,176 parts, Tespol 1310.164 parts, linseed oil, 30 parts, alkyd resin (Betucosol EX-
8011 (manufactured by Dainippon Ink & Chemicals, Ltd.) was added, heated to 150°C and stirred, then 1.6 parts of isophorone diisocyanate was added and kept stirring for 10 minutes.

Further heat to 200°C and keep stirring for 40 minutes to form a varnish 8
I got it.

In addition, Varnish 8 was added to the apparatus used in Varnish Production Example 1.
Pour 82 parts, raise the temperature to 130°C, and use it as a gelling agent.
Said aluminum chelate, 6 parts and Efsol D-110.1
A premixed mixture of 2 parts was added, and the mixture was stirred and held at 180° C. for 60 minutes to obtain heat-setting gel varnish 8.

Varnish production example 8 using Susanyo (1 child) L and the equipment used in varnish production example 1.
Varnish 9 and heat-setting gel varnish 9 were obtained using the same amount of charge and procedure except that the crosslinking agent was changed to 1 and 2 parts of Chemitite PZ-33.

Varnish ゛ 10 Using the equipment used in Varnish Production Example 1, Varnish Production Example 8
Varnish 10 and gel varnish 10 for heat setting were obtained using the same amount of preparation and the same procedure except that the crosslinking agent was changed to 1 and 2 parts of Bunacol EX-314.

Varnish preparation 1 Using the equipment used in varnish production example 1, 164 parts of No. 6 solvent, 1310.176 parts of Tespol, linseed oil,
Comparative varnish 1 was obtained by charging 60 parts, heating to 200°C, and stirring and holding for 40 minutes.

In addition, 382 parts of Comparative Varnish 1 was charged into the apparatus used in Varnish Production Example 1, the temperature was raised to 130°C, and 6 parts of aluminum chelate and 1.2 parts of No. 6 solvent were mixed in advance as gelling agents. was added, and the mixture was stirred and held at 180°C for 60 minutes to obtain comparative gel varnish 1 for single wafer use.

Comparison Varnish Production Example 2 Using the equipment used in Varnish Production Example 1, 140 parts of high-boiling petroleum solvent (No. 6 Solvent), 200 parts of rosin-modified phenolic resin (Tespol 1310), linseed oil,
Comparative varnish 2 for sheet wafers was obtained by adding 60 parts of the varnish, heating it to 200° C., stirring and holding it for 40 minutes, and cumming.

Varnishing 3 Using the equipment used in Varnish Production Example 1,
110.184 parts of Tespol, 1310.176 parts of Tespol, and 40 parts of linseed oil were charged, heated to 200°C, and kept stirring for 40 minutes to obtain Comparative Varnish 3.

Further, 382 parts of Comparative Varnish 3 was charged into the apparatus used in Varnish Production Example 1, and the temperature was raised to 130°C.
12 parts of the gel varnish was mixed in advance, and the mixture was stirred and held at 180° C. for 60 minutes to obtain comparative gel varnish 3 for heat setting.

Varnishing 4 Using the equipment used in varnish production example 1,
10.172 parts of Despol 1310.168 parts, 30 parts of linseed oil, and 30 parts of Betsukosol EL-801 were charged, heated to 200°C, and kept stirring for 40 minutes to obtain Comparative Varnish 4.

In addition, the comparative varnish was added to the equipment used in Varnish Production Example 1.
Charge 82 parts, raise the temperature to 130°C, add 6 parts of the above-mentioned aluminum chelate as a gelling agent, and Efsol D-110, 12.
A pre-mixed mixture of the following components was added, and the mixture was stirred and held at 180° C. for 60 minutes to obtain comparative gel varnish 4 for heat setting.

5 parts of each of the varnishes obtained in Varnish Production Example 1.2.3 and Comparative Varnish Production Example 1, 70 parts of gel varnish, and red pigments (Sumiyoku Print Carmine 6BC-305, After adding 18 parts of Kacolor Co., Ltd.) and dispersing with a 3-roll mill, and adding 1.0 part of a cobalt dryer, using a No. 6 solvent and each gel varnish, the spread meter 60 second value was 36 to 38. Adjustments were made so that each sheet-fed ink was created.

In addition, 55 parts of each varnish obtained in Varnish Production Example 4 and Comparative Varnish Production Example 2, 20 parts of the gel varnish obtained in Comparative Varnish Production Example 1, and Sumiyoku Print Carmine 6BC were added.
- Add 305.18 parts and disperse with a three-roll mill,
After adding 1.0 part of cobalt dryer, using No. 6 solvent and each varnish, the spread meter 60 second value was adjusted to 36 to 38, and sheet inks were prepared.

Furthermore, varnish production examples 5 to 10 and comparative varnish production example 3
．． 5 parts of each varnish obtained in 4, gel varnish, 65
Add 18 parts of Sumiyoku Print Carmine 6BC-305 to 100% and disperse with 3 rolls. Spread meter 60 seconds value is 38 with Fsol D-110 and gel varnish.
~40, and heat set inks were created for each.

Varnish properties Varnish production examples 1 to 3.5 to 9 and comparative varnish production example 1
．． The following physical properties were measured for each gel varnish obtained in 3.4 and the varnish obtained in Varnish Production Example 4 and Comparative Varnish Production Example 2, and the results are shown in Table 1.

Coating: Two Notes) n-hexane) Relance indicates the compatibility of norhexane with 5 g of varnish at 25°C, and is expressed as the amount of n-hexane at the time when the varnish becomes cloudy.

As described above, varnishes 1 to 10 according to the present invention have a lower acid value and normal hexane tolerance and a higher (weight average) molecular weight than the corresponding comparative varnishes. , it can be seen that a reaction with the crosslinking agent is occurring.

For sheet-fed inks using the respective varnishes obtained in Varnish Production Examples 1 to 4 and Comparative Varnish Production Examples 1.2, a DAIYA sheet-fed offset printing machine manufactured by Mitsubishi Heavy Industries, Ltd. was used, and Varnish Production Examples 5 to 4 were used. 10 and Comparative Varnish Production Example 3.4
The heat set inks using each of the varnishes obtained in the above were tested for underwater suitability and drying properties using a Geibau offset rotary press made by Juju Industries Co., Ltd., and the results are shown in Tables 2 and 3. It was shown to.

Note that the evaluation was performed using the following method.

Sheet-fed ink〉 Water width suitability: If the printing machine is printing with a water volume that does not affect print quality, if the water volume dial is set high, water marks will occur, and if it is set low, smudges will occur. do. The difference between this overmark and the water amount dial value that does not cause staining was considered underwater, and the dial value was evaluated.

Drying property (setting): The printed matter discharged from the printing machine was subjected to an automatic setting tester (Toyo Seiki Seisaku Seiki), and the drying property was expressed as the time it took for the ink to no longer offset against the blank paper stacked on top of the printed matter.

heat set ink> It was evaluated using the same method as the water width suitable bileaf ink.

However, the numbers on the dial differ depending on the printing press.

Drying property: The printed matter after passing through the printing machine and the dryer is assumed to be in a dry state when the ink is no longer sticky to the touch, and expressed as the temperature of the paper surface immediately after the dryer at that time.

Table 2 Table 3 Effect> As is clear from the above results, the ink using the lithographic printing varnish of the present invention has a wide water width and is excellent in printing suitability, and the ink setting and drying properties are significantly improved. It can be seen that there is an improvement in

Claims (1)

[Scope of Claims] 1) A lithographic printing ink varnish mainly composed of a high-boiling petroleum solvent and a binder resin, characterized in that a crosslinking agent is further added to crosslink the binder resin. Varnish for ink. 2) 0.001 to 1 for lithographic printing ink varnish
．． The lithographic printing ink varnish according to claim 1, further comprising 0.00% by weight of a crosslinking agent. 3) The lithographic printing ink varnish according to claim 1, wherein the binder resin contains any one of a phenolic resin, an alkyd resin, or a rosin ester resin as an essential component. 4) The lithographic printing ink varnish according to claim 1, wherein the crosslinking agent is a compound selected from an aziridine compound, a polyisocyanate compound, and an epoxy compound. 5) The lithographic printing ink varnish according to claim 1, wherein a crosslinking agent is added to a mixture of a high boiling point petroleum solvent and a binder resin, and a crosslinking reaction is carried out at a temperature of 170° C. or lower. 6) A lithographic printing ink composition mainly comprising a colorant and the lithographic printing ink varnish according to claims 1 to 5.