JPH09111171A - Waterless lithographic printing ink - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a printing ink that has no concern about pollution or odor of working environment and has sufficient printability and printing effect as a waterless planographic printing ink. SOLUTION: This is a rosin-modified phenol resin containing rosins, a resol type phenol resin and a polyhydric alcohol as components, and the resol type phenol resin has phenol having a long chain alkyl group having 10 to 15 carbon atoms as phenol. To 60% by weight and 80 to 40% by weight of phenols having an alkyl group having 9 or less carbon atoms, and a resol type phenol resin having a weight average molecular weight of 100,000 to 50.
The content of the rosin-modified phenolic resin having an opaque point of 30 to 70% as defined below and the aromatic hydrocarbon is 1
A waterless lithographic printing ink comprising a petroleum solvent in an amount of not more than 10% by weight. White cloud point (%): Resin (2 g) / [Resin (2 g) + Solvent (Xg)] × 100 (where X is normal tetradecane added to 2 g of resin and heated and dissolved at 180 to 200 ° C., then 25 This is the minimum amount of normal tetradecane that causes the solution to become cloudy when cooled to ℃.)

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in printability such as resistance to background stain and printability such as gloss and halftone dot reproducibility, with less contamination of working environment by aromatic petroleum solvent. It relates to waterless lithographic printing inks.

[0002]

2. Description of the Related Art In lithographic printing, which is the mainstream of current printing, a dampening solution is supplied to a non-image area, and an image is formed by utilizing ink repulsion. In recent years, a waterless lithographic printing method has been proposed as a method for solving the problem relating to the dampening solution. In particular, printing is performed by providing silicone rubber in the non-image area for the purpose of showing ink repellency in place of the dampening solution. Has been put to practical use. It is known that printing with a conventional oil-based ink in such a waterless lithographic printing cannot obtain sufficient ink repulsion in a non-image area and causes smearing, which is not preferable. 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 machine during printing, and the fact that dampening water is not used and the cooling effect of the plate surface due to water evaporation disappears. As the temperature rises, the cohesive force of the ink itself decreases, and the ink adheres to the non-image areas where the ink should be repelled. In order to solve the problem peculiar to waterless printing, the resin component in the vehicle is made high molecular weight to increase the cohesive force.
Techniques such as adding silicone oil, using a silicone-modified resin, and using a thickener to increase cohesive force have been taken. However, in the above-mentioned method, although the smear resistance is improved, there is a problem that it is difficult to obtain a good printed matter due to deterioration of so-called printability such as transferability between ink rollers during printing and stability on a printing machine. there were.

On the other hand, aromatic components such as benzene, toluene and xylene among various solvents that have been widely used in the past have been irritating to the human body, as regulated by the Industrial Safety and Health Law. Strict regulations have been adopted to bring about sexual and neuropathy. Also recently ILO
Just as the (International Labor Organization) has chosen a treaty to protect the safety of workers handling chemicals, there is a growing international momentum to protect humans from the harm of chemicals. The conventional solvent for printing ink contains 15 to 20% by weight of an aromatic component in addition to the paraffinic and naphthenic components, which causes a problem of odor and work environment pollution.

In order to improve such problems as much as possible, among the solvents for printing inks, a solvent containing no aromatic component is used as compared with a conventional 100% normal paraffin solvent or a recently developed naphthene component. A method has been adopted in which the solvent is used in combination with a conventional solvent. Even in that case, the problem of contamination of the working environment was not solved, and the printability as a waterless lithographic printing ink and the printing effect were insufficient.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a printing ink having no fear of pollution or odor of working environment and having sufficient printability and printing effect as a waterless planographic printing ink. .

[0006]

Means for Solving the Problems That is, the present invention is a rosin-modified phenol resin containing rosins, a resole-type phenol resin and a polyhydric alcohol as components, wherein the resole-type phenol resin has 10 to 10 carbon atoms as phenol. 1
5 is a resole-type phenol resin containing 20 to 60% by weight of a phenol having a long-chain alkyl group and 80 to 40% by weight of a phenol having an alkyl group having 9 or less carbon atoms, and having a weight average molecular weight of 100,000 to 500,000. In waterless lithographic printing characterized by comprising a rosin-modified phenolic resin having a cloud point of 30 to 70% as defined below and a petroleum solvent having an aromatic hydrocarbon content of 1% by weight or less. Ink. White cloud point (%): Resin (2 g) / [Resin (2 g) + Solvent (Xg)] × 100 However, X is 25 ° C. after adding normal tetradecane to 2 g of the resin and heating and dissolving at 180 to 200 ° C. This is the minimum amount of normal tetradecane that causes the solution to become cloudy when cooled to. )

Further, the present invention is the above waterless lithographic printing ink which is a rosin-modified phenol resin further containing unsaturated dicarboxylic acid as a reaction raw material. Further, the present invention provides the above waterless lithographic printing ink, wherein the rosin-modified phenolic resin has a resin viscosity defined below of 160 to 550 poise. Resin viscosity: Resin / linseed oil = 1
A varnish obtained by heating and stirring and dissolving a mixture having a weight ratio of / 2 at 180 to 200 ° C. was measured by a cone plate viscometer.
Viscosity in ° C. Further, the present invention is the above waterless lithographic printing ink in which the petroleum solvent has an aniline point of 75 to 95 ° C and a boiling point of 230 to 350 ° C.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The rosin-modified phenolic resin used in the present invention contains rosin, a resol type phenolic resin and a polyhydric alcohol as components, and has 10 to 15 carbon atoms as a phenol constituting the resol type phenolic resin.
20 to 60% by weight of phenols having long-chain alkyl groups and phenols 8 having alkyl groups having 9 or less carbon atoms
It is a rosin-modified phenol resin composed of a resol type phenol resin in an amount of 0 to 40% by weight. 10 to 15 carbon atoms
Examples of the long-chain alkylphenol include decylphenol, undecylphenol, dodecylphenol, tridecylphenol, tetradecylphenol, and pentadecylphenol.

Examples of the alkylphenol having 9 or less carbon atoms include cresol, butylphenol, amylphenol, octylphenol and nonylphenol. As a method for producing the resol-type phenol resin, a known method of reacting phenols with aldehydes such as formalin, paraformaldehyde and acetaldehyde under an alkali catalyst can be used. In the present invention, by producing a resol-type phenol resin in a state where a long-chain alkylphenol having 10 or more carbon atoms is contained as a phenol in an amount of 20 to 60% by weight, the entanglement of alkyl groups becomes an appropriate density, and rosin modification occurs. Solubility as a phenol resin, molecular weight, and resin viscosity become suitable.

The rosin-modified phenolic resin used in the present invention has a weight average molecular weight (hereinafter simply referred to as "molecular weight") of 100,000 to 500,000, preferably 150,000 to 300,000, and a clouding point for normal tetradecane. Thirty
˜70%, preferably 40-60%. Molecular weight 1
If it is less than 0,000, the cohesive force of the varnish is insufficient, and therefore, sufficient background stain resistance as an ink cannot be obtained, which is not preferable. If the cloud point is less than 30%, the solubility of the resin is too good, the viscosity of the ink becomes too low, and the drying property becomes poor, which is not preferable. Further, if the cloud point exceeds 70%, not only the pigment dispersibility of the varnish becomes insufficient, but also
It is not preferable because the fluidity, gloss, and inking property of the ink are poor. The rosin-modified phenolic resin according to the present invention must be contained in the ink in an amount of 20 to 40% by weight, preferably 25 to 35% by weight. If it is less than 20% by weight, the cohesive force of the ink is insufficient and the smear resistance is poor. When the content exceeds the weight%, the fluidity of the ink becomes poor, which is not preferable.

Further, the rosin-modified phenol resin of the present invention has a resin viscosity of 160 to 550 poise, preferably 200 to 50 poise.
450 poise is good. If the resin viscosity is less than 160 poise, the tack of the ink becomes too high, which is liable to cause paper waste, while if it exceeds 550 poise, the fluidity, transferability and inking property of the ink deteriorate. Therefore, it is not preferable.

The rosin-modified phenolic resin used in the present invention contains, as an unsaturated dicarboxylic acid, maleic acid or fumaric acid in an amount of 0.1 to 3% by weight, preferably 0.5 to
By containing 2% by weight, a higher molecular weight and a higher resin viscosity can be obtained, and the background resistance of the waterless ink is improved, which is preferable. Further, among the phenols used for the resol type phenol resin according to the present invention, the number of carbon atoms is 1
When p-dodecylphenol is used as the long-chain alkylphenol having a number of 0 to 15, the solubility, the molecular weight, and the resin viscosity are best balanced, which is preferable.

Other raw materials for the rosin-modified phenol used in the present invention include gum rosin, wood rosin, polymerized rosin, tall oil rosin, disproportionated rosin as rosins, and glycerin, pentaerythritol, trimethylolpropane as polyhydric alcohols. , Diethylene glycol and the like, and vegetable oils such as linseed oil and tung oil, and modifiers such as petroleum resins. As a method for producing the rosin-modified phenol resin, a known method can be used, and 100 parts by weight of rosin is used to prepare a resol type phenol resin 40-1.
After reacting 30 parts by weight at 100 to 250 ° C., 0.5 to 1.2 equivalents of hydroxyl groups of alcohols are added to 1 equivalent of carboxylic acid of rosins, and 2
There are a method of esterifying at 50 to 260 ° C., a method of reacting a resol type phenol resin after esterifying rosin with a polyhydric alcohol, and finally taking out an acid value of about 25 or less.

The ink solvent used in the present invention is a petroleum solvent having an aromatic hydrocarbon content of 1% by weight or less. This petroleum solvent is preferably a petroleum solvent having an aniline point of 75 to 95 ° C, preferably 75 to 90 ° C and a boiling point of 230 to 350 ° C, preferably 270 to 350 ° C. If the aniline point is lower than 75 ° C., the ability to dissolve the resin is too high, so the viscosity of the ink becomes too low,
Further, the drying property is poor and not preferable, and when the temperature exceeds 95 ° C., the dissolving power of the resin is poor, the fluidity of the ink is poor, and as a result, only printed matter having poor gloss and inking property can be obtained, which is not preferable. . If the boiling point is below 230 ° C,
It is not preferable because the evaporation of the solvent in the ink on the printing machine increases, the fluidity of the ink deteriorates, and the ink easily accumulates on the roller or blanket.
If the temperature exceeds ℃, the drying property of the heat-set type ink is poor, which is not preferable.

The solvent for the ink according to the present invention is used in the ink.
It is preferable to contain 5 to 50% by weight, preferably 30 to
It is preferably 45% by weight, and it is preferable not to use a petroleum solvent containing another aromatic hydrocarbon in an amount of 1% by weight or more in the ink. As a matter of course, when a petroleum solvent containing another aromatic hydrocarbon is used in combination, the effect of improving odor and working environment becomes insufficient, which is not preferable.

As the ink solvent used in the present invention, AF solvent 4, 5, 6, 7 manufactured by Nippon Oil Co., Ltd.
And Mitsubishi Kasei Co., Ltd. alpha olefin dialene. The waterless planographic printing ink of the present invention is produced by a conventional method using a varnish prepared by dissolving the rosin-modified phenolic resin in the petroleum solvent. The varnish used in the present invention can be produced by a conventionally known method, and includes a resin, a drying oil (linseed oil, thermally polymerized linseed oil, air-blown polymerized oil, etc.), a solvent for ink, and, if necessary, aluminum stearate. Together with a gelling agent such as an aluminum chelate compound at 180 to 200 ° C. to cause a reaction.

[0017]

Now, the present invention will be described in further detail with reference to specific examples. Hereinafter, “part” indicates “part by weight” and “%” indicates “% by weight”.

Phenolic Resin Production Example 1 A mixture of 1030 parts of P-octylphenol, 290 parts of paraformaldehyde and 800 parts of xylene was heated and dissolved in a four-necked flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer, and then heated to 48%. Add 80 parts of sodium hydroxide aqueous solution and react at 70-80 ° C for 5 hours. After the reaction, 6N hydrochloric acid 1
25 parts of tap water and 200 parts of tap water were added and left to stir, and the supernatant layer was taken out and washed with water to obtain about 2100 parts of a xylene solution of a resole-type phenol resin having a nonvolatile content of 62%, which was used as an A resol solution.

Phenol Resin Production Example 2 A resol type phenol having a nonvolatile content of 64% was carried out by the same procedure except that p-octylphenol in the production process of the A resol solution was replaced with 515 parts of p-octylphenol and 655 parts of p-dodecylphenol. About 2200 parts of a xylene solution of the resin was obtained, and this was used as a B resol solution.

Phenol Resin Production Example 3 A resol type having a nonvolatile content of 63% was prepared by the same procedure except that p-octylphenol was replaced by 720 parts of p-octylphenol and 375 parts of p-dodecylphenol in the production process of the A resol solution. About 2100 parts of a xylene solution of a phenol resin was obtained, and this was used as a C resol solution.

Phenol Resin Production Example 4 The same operation was performed except that p-octylphenol in the production process of the A resol solution was replaced with 860 parts of p-octylphenol and 270 parts of p-dodecylphenol, and a resol type having a nonvolatile content of 63% was used. About 2200 parts of a xylene solution of a phenol resin was obtained, and this was used as a D resol solution.

Phenol Resin Production Example 5 The same operation was carried out except that p-octylphenol in the production process of the A resol solution was replaced with 740 parts of p-octylphenol and 320 parts of p-pentadecylphenol.
About 2100 parts of a xylene solution of a resol type phenol resin having a nonvolatile content of 62% was obtained, and this was used as an E resol solution.

Producing Example 1 of rosin-modified phenolic resin 600 parts of gum rosin was charged into a four-necked flask equipped with a stirrer, a Liebig condenser, and a thermometer, and the mixture was dissolved and stirred at 200 ° C. while blowing nitrogen gas.
After reacting 5 parts at 120 to 200 ° C, 63 parts of glycerin was charged and esterified at 250 to 260 ° C to an acid value of 25 or less to obtain a resin 1 having a molecular weight of 53,000 and a clouding point of 75% and a resin viscosity of 140 poise. It was

Production Example 2 of rosin-modified phenolic resin The same operation was carried out except that 970 parts of A resole solution was used in the production process of Resin 1, and the molecular weight was 45,000 and the cloud point was 4.
Resin 2 having 0% and a resin viscosity of 100 poise was obtained.

Production Example 3 of rosin-modified phenolic resin A resole solution in the production process of resin 1 was replaced with B resole solution 63
The same operation was performed except that the amount was replaced with 0 part, and the molecular weight was 17
Resin 3 having a viscosity of 4,000, a clouding point of 45% and a resin viscosity of 165 poise was obtained.

Production Example 4 of rosin-modified phenolic resin A Resol solution in the production process of Resin 1 is replaced with B Resol solution 77
The same operation was performed except that the molecular weight was changed to 0 part, and the molecular weight was 25
A resin 4 having a viscosity of 4,000, a clouding point of 52% and a resin viscosity of 230 poise was obtained.

Production Example 5 of rosin-modified phenolic resin A Resol solution in the production process of Resin 1 was replaced with C Resol solution 80
The same operation was repeated except that the molecular weight was changed to 0 part.
A resin 5 having a viscosity of 4,000, a clouding point of 58% and a resin viscosity of 200 poise was obtained.

Production Example 6 of rosin-modified phenolic resin A resole solution in the production process of resin 1 was replaced with C resole solution 95
The same operation was performed except that the molecular weight was changed to 0
Resin 6 having a viscosity of 6,000, a clouding point of 65% and a resin viscosity of 280 poise was obtained.

Production Example 7 of rosin-modified phenolic resin A Resol solution in the production process of Resin 1 was replaced with D Resol solution 72
The same operation was carried out except that 0 part was added and 13 parts of maleic acid was added, and the molecular weight was 436,000 and the cloud point was 6
Resin 7 having 8% and a resin viscosity of 520 poise was obtained.

Production Example 8 of rosin-modified phenolic resin A Resol solution in the production process of Resin 1 was replaced with D Resol solution 10
The same procedure was repeated except that the amount was replaced with 80 parts, and the molecular weight was 2
Resin 3 having a viscosity of 4,000, a cloudiness point of 54% and a resin viscosity of 425 poise was obtained.

Production Example 9 of rosin-modified phenolic resin A Resol solution in the production process of Resin 1 was replaced with E Resol solution 91
The same operation was repeated except that the molecular weight was changed to 0 part, and the molecular weight was 28
Resin 9 having a viscosity of 6,000, a clouding point of 48% and a resin viscosity of 320 poise was obtained.

Varnish Production Example The resins, linseed oil, solvent and gelling agent obtained in the rosin-modified phenol resin production example were blended as shown in Table 1, and heated and stirred at 190 ° C. for 1 hour to obtain gel varnishes AJ.

[0033]

[Table 1] Note) AF solvent 5 Nippon Oil Co., Ltd. solvent: aniline point 88.2 ° C, boiling point 279-307 ° C, aromatic component content 0.
2% AF Solvent 7 Nippon Oil Co., Ltd. solvent: aniline point
83.5 ° C Boiling point 260-281 ° C, Aromatic component content 0.3% Solvent No. 7 Solvent made by Nippon Oil Co., Ltd. Aniline point 69.8 ° C Boiling point 255-283 ° C, Aromatic component content 17.2% ALCH: Kawaken Fine Chemicals Co., Ltd. Gelling agent

Using the composition shown in Table 2, an ink was prepared according to a conventional method using a triple roll so that the tack value was 7-8.
It was set as Examples 1-7 and Comparative Examples 1-3.

[0035]

[Table 2]

Evaluation of Printing Test The inks of the examples and comparative examples were manufactured by Mitsubishi BT2-800NE.
Table 3 shows the results of evaluation of background stain temperature, inking property, gloss, and odor by performing waterless printing at 800 rpm on an O-off rotary printing press using a TAP plate manufactured by Toray Industries, Inc.

[0037]

[Table 3]

It can be seen that the inks of Examples 1 to 7 according to the present invention are not only excellent in background stain temperature, inking property and gloss, but also less in work environment pollution. On the other hand, the inks of Comparative Examples 1 to 3 could not simultaneously satisfy all the aspects of the background stain temperature, the ink receptivity, the gloss, and the improvement of the working environment.

[0039]

INDUSTRIAL APPLICABILITY As described above, the waterless lithographic printing ink obtained by the method of the present invention has no contamination of the working environment and has sufficient printability and printing effect as a waterless lithographic printing ink. To give.

Claims (4)

[Claims] 1. A rosin-modified phenol resin containing rosins, a resol-type phenol resin and a polyhydric alcohol as a component, wherein the resol-type phenol resin has a long chain alkyl group having 10 to 15 carbon atoms as phenol. A resol type phenolic resin having 20 to 60% by weight and 80 to 40% by weight of phenols having an alkyl group having 9 or less carbon atoms and having a weight average molecular weight of 100,000 to 5
No water characterized by comprising a rosin-modified phenolic resin having a cloud point of 30 to 70% as defined below at 0,000 and a petroleum solvent having an aromatic hydrocarbon content of 1% by weight or less. Ink for planographic printing. White cloud point (%): Resin (2 g) / [Resin (2 g) + Solvent (Xg)] × 100 (where X is normal tetradecane added to 2 g of resin and heated and dissolved at 180 to 200 ° C., then 25 This is the minimum amount of normal tetradecane that causes the solution to become cloudy when cooled to ℃.) 2. The waterless lithographic printing ink according to claim 1, which is a rosin-modified phenolic resin further containing an unsaturated dicarboxylic acid as a reaction raw material. 3. The rosin-modified phenolic resin has a resin viscosity as defined below of 160 to 550 poise.
Or the waterless lithographic printing ink according to 2. Resin viscosity: Resin / linseed oil = 1/2 to 180% of the mixture
Viscosity of a varnish obtained by heating and stirring at 0 ° C. at 25 ° C. by a cone-plate viscometer. 4. The petroleum solvent has an aniline point of 75 to 95 ° C.
4. The waterless lithographic printing ink according to claim 1, which has a boiling point of 230 to 350 ° C.