JP2001164166A - Preparation process of resin composition for printing ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for easily preparing a resin for printing inks which has a large molecular weight, a high softening point, a high viscosity and an excellent property for high-speed printing. SOLUTION: Against 100 pts.wt. rosin or its derivative, 50 to 150 pts.wt. phenol formaldehyde initial condensate and 0.1 to 1.5 mol equivalent polyhydric alcohol against carboxylic acid of the above rosin or its derivative are mixed and heated to produce a rosin-modified phenol resin. Here, as soon as the weight average molecular weight of the reaction product reaches 1,000, 1 to 100 pts.wt. solvent for offset printing inks having a boiling point of 160 to 320 deg.C, is added.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rosin-modified phenolic resin composition for printing ink having excellent printability in offset printing.

[0002]

2. Description of the Related Art Conventionally, a rosin-modified phenol resin used for offset printing ink is prepared by adding a phenol resin and a polyhydric alcohol to a molten rosin, and adding the rosin to the rosin in an amount of 250 to 270.
Generally, a bulk polymerization method in which the reaction is carried out at a high temperature of ° C is used.

[0003] The resin is added to an ink solvent and a drying oil, and if necessary, a gelling agent is added to the resin to form a resin of 140 to 24.
The varnish for printing ink is manufactured by heating and dissolving at 0 ° C. and cooking.

[0004]

In the printing industry in recent years, the speed of printing presses has been increasing in response to the trend of improving productivity, and as a result, misting suppression and drying property have been improved as printing ink resins. There is a demand for improvement in high-speed printing suitability. It is considered that the suitability for high-speed printing depends on the viscoelasticity of the ink. In order to obtain such performance, it is required that the resin has a large molecular weight, a high softening point, and a high viscosity when melted.

However, in the conventional bulk polymerization method, if a resin having a sufficiently high molecular weight is to be obtained, the melt viscosity is high, so that the stirring load is large, and the reaction system is liable to be non-uniform, since the stirring is not sufficient. . Therefore, the molecular weight distribution varies, and a uniform resin cannot be obtained.

It is very difficult to remove such a high-viscosity resin from the reaction vessel after the reaction. After completion of the reaction, the resin may be dissolved in a solvent and taken out. However, the high molecular weight resin synthesized by bulk polymerization has a high viscosity, and it is difficult to dissolve the resin in the solvent.

The present invention has been made in view of the above circumstances and provides a method for easily producing a printing ink resin having a high molecular weight, a high softening point, a high viscosity, and excellent high-speed printing characteristics. The purpose is to do so.

[0008]

Means for Solving the Problems Thus, the present invention relates to 50 to 150 parts by weight of a phenol formaldehyde precondensate and 100 parts by weight of rosin or a derivative thereof and carboxylic acid of the rosin or derivative thereof. 0.1 ~
In mixing 1.5 molar equivalents of a polyhydric alcohol and reacting it by heating to produce a rosin-modified phenolic resin, when the weight average molecular weight of the reaction product becomes 1000 or more, the boiling point is 160 ° C. It is characterized by adding 1 to 100 parts by weight of a solvent for offset printing ink at 320 ° C.

In the present invention, it is preferable to add 1 to 50 parts by weight of vegetable oil together with the rosin-modified phenol resin.

That is, the present invention relates to a method for synthesizing a rosin-modified phenolic resin by reacting rosin or a derivative thereof, a phenol formaldehyde initial condensate, and a polyhydric alcohol, wherein only the three components are used in the initial stage of the synthesis. Performed by a bulk polymerization method, at the time when the polymerization average molecular weight of the product becomes 1000 or more, add a solvent and, if necessary, vegetable oil, and thereafter, shift to a solution polymerization step in a state of being dissolved in the solvent, The reaction is completed.

The obtained rosin-modified phenol resin can be pumped out as it is as a solid, and can be further taken out as a varnish by adding a solvent and a drying oil. Furthermore, it is also possible to take out as a gel varnish gelled by adding a gelling agent.

As the rosin used in the present invention, gum rosin, wood rosin or tall oil rosin can be used, and their distilled rosins can also be used.
Derivatives of these rosins include disproportionated rosin,
Hydrogenated rosin and polymerized rosin can be used, and those obtained by modifying them with a dibasic acid or its anhydride can also be used.

The dibasic acids or anhydrides used for the modification include fumaric acid, maleic acid, maleic anhydride, adipic acid, itaconic acid, phthalic anhydride, isophthalic acid, terephthalic acid, trimellitic anhydride and the like. Can be

As the phenol-formaldehyde precondensate used in the present invention, a resol-type phenol resin having a nucleus of 1 to 8 nuclei, which is formed into a resol or a novolak and then into a resol, is preferable.

As the phenols used in the resole type phenol resin, all aromatic compounds having a phenolic hydroxyl group can be used. Among them, alkylphenol compounds having an alkyl substituent having 4 to 12 carbon atoms at the para position of the hydroxyl group can be used. Alternatively, bisphenol A is preferred. As the aldehyde donor component, paraformaldehyde and an aqueous solution of formalin are used.

A resol type phenol resin is synthesized from the phenols and the aldehyde donor component using an alkali catalyst. As the alkali catalyst, an alkali catalyst such as potassium hydroxide, sodium hydroxide, calcium hydroxide, magnesium hydroxide, and an aqueous ammonia solution is used.

The polyhydric alcohol used in the present invention includes, for example, glycerin, trimethylolethane, trimethylolpropane, diethylene glycol, triethylene glycol, trimethylolpropane, pentaerythritol, dipentaerythritol and the like.

The amount of the polyhydric alcohol used is closely related to the solubility and softening point of the obtained rosin-modified phenol resin. Usually, 0.1 to carboxylic acid of rosin component
It is suitably from 1.5 to 1.5 molar equivalents, preferably from 0.3 to 1.1 molar equivalents.

If the amount of the polyhydric alcohol is too large, hydrophilic alcoholic hydroxyl groups remain in the obtained resin, so that the solubility of the resin decreases and the emulsification resistance after the ink is formed deteriorates. Therefore, it is not preferable.

The solvent for offset printing ink used in the present invention is a paraffinic, naphthenic or aromatic solvent having a boiling point of 180 ° C. to 320 ° C., and is generally commercially available as a solvent for offset printing ink. Can be used as is.

The vegetable oil used in the present invention includes:
Linseed oil, polymerized linseed oil, dehydrated castor oil, soybean oil, tall oil, safflower oil, cinnamon oil and perilla oil can be used.

The resin obtained according to the present invention is mixed with an ink solvent and a drying oil, and if necessary, a gelling agent is added thereto. Varnish. Then, a pigment is dispersed in the varnish, and if necessary, a friction resistance improver, an ink dryer, a drying inhibitor, and the like are added, and the viscosity is adjusted to obtain a printing ink. It is suitable for offset printing such as sheet-fed ink and web offset ink, but can also be used as newspaper ink or letterpress ink.

[0023]

Next, the present invention will be described with reference to specific examples. In the following description, “parts” and “%” are parts by weight and weight%.
Represents

Production Example (Production of resol type phenol resin) In a four-necked flask equipped with a stirrer, a reflux condenser and a thermometer, 825 parts of p-octylphenol, 228 parts of bisphenol A and 326 parts of 92% paraformaldehyde were added.
And 130 parts of xylene were charged and dissolved by heating to 60 ° C., and then 5.2 parts of potassium hydroxide were added. The mixture is further heated to 90 ° C. and reacted for 5 hours to prepare a resol having an average of 4 nuclei. Xylene 1
It was dissolved in 10 parts and the solid content concentration was adjusted to 85%.

Example 1 In a four-necked flask equipped with a stirrer, a reflux condenser equipped with a water separator, and a thermometer, 220 parts of gum rosin, 170 parts of the resole-type phenol resin produced in the production example, and 19 parts of pentaerythritol And 5 parts of glycerin, and the mixture is heated while blowing in and stirring with nitrogen gas to dissolve the resin and make it uniform.

Thereafter, the temperature was raised to 260 ° C. over 7 hours while recovering xylene and water with a reflux condenser equipped with a water separator. At this point, the average molecular weight of the resin composition is
1300.

At this time, 30 parts of Nisseki AF No. 6 solvent manufactured by Nippon Oil Co., Ltd. were charged and reacted at the same temperature for 8 hours, acid value 20, average molecular weight 180,000, n-hexane tolerance 1.
358 parts of an 8 g / g resin were obtained.

Nisseki AF No. 6 Solvent 290
Parts, soybean oil 160 parts and Kawaken Fine Chemical Co., Ltd. gelling agent ALCH5 parts were mixed in a four-necked flask, and the resin composition was added thereto. The mixture was aged at an internal temperature of 190 ° C. for 1 hour, and had a viscosity of 83 Pa.S. 820 parts of gel varnish were obtained.

Example 2 Using the same reactor as in Example 1, 220 parts of gum rosin, 19 parts of pentaerythritol, and 5 parts of glycerin were charged into a four-necked flask, and heated while stirring by blowing in nitrogen gas. Then, an esterification reaction was performed at 270 ° C. for 8 hours to obtain a rosin ester having an acid value of 15.

Thereafter, 170 parts of the resol-type phenol resin produced in the production example was dropped at 260 ° C. over 6 hours. After the start of the dropping, the weight average molecular weight of the resin composition is 1000
When it reached 0, 30 parts of Nisseki AF No. 6 solvent were charged. After completion of the dropping of the resole resin, the mixture was reacted at the same temperature for 2 hours to obtain 358 parts of a resin having an acid value of 12, an average molecular weight of 320,000, and n-hexane tolerance of 2.6 g / g.

The same operation as described in Example 1 was performed on this resin to obtain a gel varnish 82 having a viscosity of 92 Pa.S.
0 parts were obtained.

Example 3 With the same composition and operation as in Example 1, when the weight average molecular weight of the resin composition reached 1300, 30 parts of Nisseki AF6 solvent and 30 parts of tall oil fatty acid were added. The obtained resin had an acid value of 20, an average molecular weight of 160,000 and n-
Hexane tolerance was 2.4 g / g.

When a gel varnish was obtained from this resin in the same manner as in Example 1, the amount of soybean oil used was 130
Department. The viscosity of the finally obtained gel varnish was 72 Pa.S.

Comparative Example 1 In the same operation as in Example 1, a resin was synthesized without adding Nisseki AF7 solvent. In this operation, two hours after the temperature was raised to 260 ° C., the resin was rolled up in a stirrer, and was pumped out in a state where stirring was impossible.

Comparative Example 2 In the same manner as in Example 1, immediately after dissolving the rosin, 32 parts of Nisseki AF6 Solvent was charged to synthesize a resin. The obtained resin had an acid value of 20, an average molecular weight of 60,000,
The n-hexane tolerance was 2.0 g / g. Thereafter, 820 parts of a gel varnish having a viscosity of 26 Pa.S was obtained in the same manner as in Example 1.

Comparative Example 3 In the same manner as in Example 2, a resin was synthesized without adding Nisseki AF No. 7 solvent at the time of resole dripping.
A resin having an acid value of 14 and n-hexane tolerance of 2.0 g / g was obtained. 820 parts of a gel varnish having a viscosity of 120 Pa.S was obtained by operating the resin in the same manner as in Example 1 except that the amount of Nisseki AF No. 6 solvent was changed to 320 parts. The varnish was in a non-uniform state in which insoluble components were dispersed.

Comparative Example 4 The same reaction as in Example 1 was performed, except that 38 parts of pentaerythritol and 10 parts of glycerin were used, and 43 parts of glycerin was used. The reaction was carried out at 260 ° C. for 8 hours without adding Nisseki AF7 solvent. 325 parts of a resin having an acid value of 24, an average molecular weight of 120,000 and n-hexane tolerance of 1.2 g / g were obtained. This resin was operated in the same manner as in Comparative Example 3 to obtain a resin having a viscosity of 70 P
820 parts of aS gel varnish were obtained.

Inks were prepared using the gel varnishes obtained in Examples and Comparative Examples, and the performance of the inks was evaluated.

A. Preparation of Ink 60 parts of each of the obtained gel varnishes and 18 parts of red pigment Carmine 6B manufactured by Toyo Ink Mfg. Co., Ltd. were mixed and dispersed using a three-roll mill, and then 0.5 parts of manganese naphthenate and AF6 Solvent were used. And the respective gel varnishes were added to adjust the tack at 25 ° C. to 9 to 10 and the 60-second diameter of the parallel plate viscometer to 32.0 to 34.0 mm to prepare a sheet-fed ink.

B. Printing Test Evaluation With respect to the sheet ink obtained from each of the examples and Comparative Examples 2 and 4, gloss, density, setting property, misting and maximum emulsification amount of the ink were measured.

In Comparative Example 1, no resin could be produced, and in Comparative Example 3, an ink could not be prepared due to a large amount of insoluble components in the varnish. The measuring method of each measurement item is as follows.

Gloss: 0.25 cc of ink, R
After the color was spread on the art paper with the whole roll of the I tester, the gloss value one day later was measured with a 60 ° -60 ° gloss meter. Density: The density was measured using a reflection densitometer on the same colored paper as that for which the gloss was measured. Set: 0.15 cc of ink is spread on art paper with a RI tester quadruple roll, then the art paper is overlaid from above, with a certain weight applied, and the degree of ink transferred to the overlaid paper every 3 minutes is observed. did. Misting: Two cups of the ink were placed on an incometer manufactured by Toyo Seiki Co., Ltd., and the state of ink scattering on white paper placed on the lower surface and the front surface of the roll when rotated at 2000 rpm for 2 minutes at a roll temperature of 40 ° C. was observed. Maximum emulsification amount: 10.0 g of ink and 20.0 g of purified water in a mortar
Was weighed, and the weight increase of the ink when kneaded with a pestle was measured as an emulsified amount.

Table 1 shows the test results.

[0044]

[Table 1]

Evaluation As is clear from Table 1, the printing ink using the rosin-modified phenolic resin obtained according to the present invention has a better balance between gloss and set than ordinary rosin-modified phenolic resin, and has a misting. And at the maximum emulsification amount,
Excellent improvement was seen.

Furthermore, the transferability of the ink is good, and the printing density becomes high when the same amount of the ink is spread on the printed test piece.
That is, the resin obtained by the present invention has extremely excellent printability at the time of printing, and exhibits such a unique performance particularly at the time of high-speed printing.

Even if a rosin-modified phenolic resin having the same composition was synthesized without adding a solvent, an appropriate ink could not be prepared as shown in Comparative Examples 1 and 3. Ink can be prepared by reducing the equivalent number of polyhydric alcohols as in Example 4, but the transferability of the ink is poor and the gloss is poor, and the performance is significantly higher than that of the ink obtained by the present invention. Inferior.

Further, when a solvent was added from the beginning of the synthesis, as shown in Comparative Example 2, Example 1 having the same composition was used.
The varnish has a lower viscosity than that of the varnish, has poor ink setting properties, and has poor misting.

[0049]

Thus, according to the present invention, it is possible to obtain a rosin-modified phenol resin for inks having good suitability for high-speed printing, and by using this resin for offset printing ink, it is possible to obtain a balance between gloss, set and misting. Excellent emulsifiability, good ink transferability, and excellent printing density.

Therefore, the sheet-fed ink has excellent drying properties, enables immediate delivery of printed matter, and can increase the content of soybean oil as a semi-dry oil. In addition, waterless inks have a good practical effect with high-speed printing aptitude, such as cohesive strength and less soiling, and off-wheel inks can increase printing machine speed and improve production efficiency. Things.

Claims (2)

[Claims] 1. A phenol formaldehyde precondensate of 50 to 1 based on 100 parts by weight of rosin or a derivative thereof.
50 parts by weight and 0.1 to 1.5 molar equivalents of a polyhydric alcohol with respect to the carboxylic acid of the rosin or a derivative thereof are mixed, and the mixture is heated and reacted to produce a rosin-modified phenol resin. When the weight average molecular weight of the product becomes 1000 or more, the boiling point is 160 ° C to 3 ° C.
A method for producing a resin composition for printing ink, comprising adding 1 to 100 parts by weight of a solvent for offset printing ink at 20 ° C. 2. The rosin-modified phenolic resin together with
The method for producing a resin composition for a printing ink according to claim 1, wherein the vegetable oil is added in an amount of 50 to 50 parts by weight.