JP2002309146A - Resin for offset ink and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin for an offset printing ink which exhibits an ability equal to or higher than that of a conventional rosin-modified phenol resin without using an alkylphenol and formaldehyde. SOLUTION: A polymerized rosin, an unsaturated dibasic acid, a polyhydric alcohol, and a polyfunctional acrylate are reacted to give a resin for an offset ink having a softening pint of 120-220 deg.C and a wt. average mol.wt. of 20,000-300,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a commercial offset ink used for printing posters, calendars, flyers, catalogs, etc., a resin for offset ink used for newspapers, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, offset ink resins have been
A rosin-modified phenol resin obtained by reacting rosin, a polyhydric alcohol, and a phenol resin has been used. Rosin-modified phenolic resin, depending on the purpose, further polymerized rosin, unsaturated dibasic acid, vegetable oil, petroleum resin, etc. Polyhydric alcohols and phenolic resins have become essential constituent materials.

[0003] Gum rosins, tall rosins and wood rosins having different raw material sources have been used, and rosins having different production areas, such as those from China, Indonesia, Vietnam, the United States, and Argentina, have been used according to their purposes. As the polyhydric alcohol, glycerin, pentaerythritol, dipentaerythritol and the like have been properly used according to the purpose. Similarly, as the phenol resin, bisphenol A-based or alkylphenol-based resole resins such as pt-butylphenol, p-octylphenol, nonylphenol, and dodecylphenol have been used according to the purpose.

[0004]

Problems to be Solved by the Invention Rosin-modified phenolic resins have been reputed for providing excellent ink performance for offset inks, but their constituent materials such as bisphenol A and alkyl phenol are used as environmental hormones (exogenous endocrine secretions). Suspicious chemicals are being investigated, and their effects on the environment and living beings are being investigated. Formaldehyde, which is a component of phenolic resins, has a problem of odor and its harmfulness, and is being eliminated in paints, adhesives and many other fields.

In view of this situation, the present inventors have conducted intensive studies. As a result, by adopting a polyfunctional acrylate as a constituent material of a resin, it is possible to use bisphenol A or alkylphenol which is suspected of being an environmental hormone. ,
Also, without using formaldehyde, which has problems with odor and harmfulness, it has been found that a new resin having performance equal to or higher than that of a conventional rosin-modified phenol resin can be obtained,
Furthermore, they have found a suitable manufacturing method, and have completed the present invention.

[0006]

That is, the present invention is obtained by reacting a polymerized rosin (a), an unsaturated dibasic acid (b), a polyhydric alcohol (c) and a polyfunctional acrylate (d). Softening point is 120-220 ° C, weight average molecular weight is 2
The present invention relates to a resin for offset ink of 000 to 300,000. The present invention also relates to a production method for synthesizing the resin by a specific method.

In the present invention, the polymerized rosin (a) is produced by dimerizing rosin using a catalyst such as sulfuric acid and, if necessary, removing unreacted rosin by a method such as distillation. It can be manufactured by itself as a raw material, or a commercially available product may be used. The softening point of the polymerized rosin is approximately 80 to 140 ° C., and the dimerization ratio is approximately 2
0 to 80%. The softening point and dimerization ratio of the polymerized rosin can be adjusted by adding rosin to the polymerized rosin.

In the present invention, the unsaturated dibasic acid (b) is
As long as it reacts with the unsaturated bond of rosin, any conventionally known one can be used, for example, maleic anhydride,
Maleic acid, fumaric acid and the like can be mentioned. The unsaturated dibasic acid is used in an amount of about 0.5 to 10 parts by mass per 100 parts by mass of polymerized rosin (including rosin added for adjusting the softening point and the dimerization ratio, hereinafter abbreviated as rosin). It is preferable that the softening point and the weight average molecular weight of the resin fall within the desired ranges.

In the present invention, the polyhydric alcohol (c) is
Conventionally known ones are used, for example, ethylene glycol, diethylene glycol, butanediol, 2-methylpentanediol, hexanediol, neopentyl glycol, glycerin, trimethylolpropane,
Examples include dimethylolpropionic acid, trimethylolethane, pentaerythritol, dipentaerythritol and the like. It is desirable that the polyhydric alcohol be approximately 5 to 15 parts by mass per 100 parts by mass of the polymerized rosin (including rosin), and within this range, the softening point and the weight average molecular weight of the resin fall within the desired ranges. Easy to put in.

In the present invention, the polyfunctional acrylate (d)
The conventionally known is used, for example, ethylene glycol diacrylate, neopentyl glycol diacrylate, hexanediol diacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, Pentaerythritol tetraacrylate and the like can be mentioned. The polyfunctional acrylate is used in an amount of about 0.1 to 20 per 100 parts by mass of polymerized rosin (including rosin).
It is desirable that the amount is in the range of parts by weight, and within this range, it is easy to keep the softening point and the weight average molecular weight of the resin within the desired ranges.

In the present invention, the softening point of the resin is from 120 to
It must be 220 ° C. When the softening point is lower than 120 ° C., the setting and drying properties of the ink become poor. Also,
If the softening point exceeds 220 ° C., it becomes difficult to prepare an ink varnish. The method for measuring the softening point in the present invention is based on the ring and ball method described in JIS K2207.

In the present invention, the weight molecular weight of the resin is 20,
000 to 300,000. When the weight average molecular weight is less than 20,000, it is difficult to obtain the elasticity required for an ink varnish and the ink has poor misting resistance. 30
If it is more than 000, it is difficult to obtain the viscosity required for the ink varnish, and the fluidity of the ink is poor. Further, due to this, fluidity, misting and the like become problems. The weight average molecular weight in the present invention is measured by gel permeation chromatography, and is a value converted into the molecular weight of monodispersed standard polystyrene.

The resin for the offset ink in the present invention may be, for example, a polymerized rosin (a), an unsaturated dibasic acid (b), a polyhydric alcohol (c) and a polyfunctional acrylate (d), if desired. Gum rosin, tall rosin, vegetable oil, polymerized vegetable oil, vegetable oil fatty acid, vegetable oil fatty acid ester, alkyd resin, petroleum resin, etc.
It is also possible to adjust the softening point, molecular weight, solubility, viscosity and the like.

The resin for offset ink in the present invention is prepared by first reacting a polymerized rosin (a), an unsaturated dibasic acid (b) and a polyfunctional acrylate (d), and then reacting the reaction product with a polyhydric alcohol (c). It can be produced by reacting. Polymerized rosin (a), unsaturated dibasic acid (b)
And a polyhydric alcohol (c), and then reacting the reaction product with a polyfunctional acrylate (d). However, the resin produced as in the latter has a smaller rate of self-polymerization of the polyfunctional acrylate, and does not generate a fine gel-like substance. It also has the advantage that it is easy to keep the point and weight average molecular weight within the intended range.

In the former synthesis, a polymerized rosin, an unsaturated dibasic acid, and a polyfunctional acrylate are charged into a reactor and reacted at a temperature of 150 to 250 ° C. Then, a polyhydric alcohol is charged into the reaction product, and a temperature of 200 ° C. React at ２280 ° C. In the latter case, a polymerized rosin, an unsaturated dibasic acid, and a polyhydric alcohol are charged into a reactor, and the temperature is 200 to 280.
C., and the reaction product is charged with a polyfunctional acrylate and reacted at a temperature of 150 to 250.degree. The esterification reaction may be without a catalyst, for example, calcium oxide,
The reaction can also be carried out by adding a suitable catalyst such as magnesium oxide, zinc oxide, zinc acetate and the like. Further, in order to remove the condensed water, the reaction can be carried out by adding an appropriate reflux solvent such as xylene.

[0016]

The present invention will be described below in detail with reference to examples. In addition, the part of preparation shows a mass part.

[0017]

Example 1 Polymerized rosin (softening point 140 ° C., dimerization ratio 80%) 720 in a reaction vessel equipped with a stirrer and water separator
Parts, 300 parts of Chinese gum rosin and 120 parts of polymerized linseed oil, and heated and stirred while blowing in nitrogen gas.
After reacting 60 parts of maleic anhydride at 24 ° C., 24 parts of 1.6-hexanediol diacrylate was reacted at 230 ° C. Thereafter, 135 parts of pentaerythritol and 1.2 parts of magnesium oxide were charged and dehydrated and condensed at 270 ° C. to react until the acid value became about 20, thereby obtaining (resin 1).

[0018]

Example 2 Into the same reaction vessel as in Example 1, 720 parts of polymerized rosin (softening point 140 ° C., dimerization rate 80%), 300 parts of Chinese gum rosin, and 120 parts of polymerized linseed oil were charged, and nitrogen gas was blown therein. After heating and stirring while reacting 60 parts of maleic anhydride at 200 ° C., 135 parts of pentaerythritol and 1.2 parts of magnesium oxide were charged and charged.
The reaction was carried out by dehydration condensation at 0 ° C. until the acid value became about 20. Thereafter, 12 parts of 1.6-hexanediol diacrylate was reacted at 230 ° C. to obtain (Resin 2).

[0019]

Comparative Example 900 parts of Chinese gum rosin were charged into the same reaction vessel as in Example 1, heated and stirred while blowing nitrogen gas, and reacted with 15 parts of maleic anhydride at 200 ° C., and then p-octylphenol at 230 ° C. 540 parts of a resole type phenol resin were dropped in 3 hours. Thereafter, 95 parts of glycerin and 0.9 part of magnesium oxide were charged and 27
It was dehydrated and condensed at 0 ° C. and reacted until the acid value became about 20, thereby obtaining (Resin 3). The p-octylphenol-based resol type phenol resin was charged with 1000 parts of p-octylphenol and 348 parts of paraformaldehyde (purity 92%) in the same reaction vessel as in Example 1, and heated and stirred.
10 g of a 10% aqueous sodium hydroxide solution as a catalyst at 0 ° C
After the addition, the mixture was kept at 90 ° C. for 4 hours for synthesis.

In addition to the measurement of the softening point and the acid value of the obtained resin, the falling ball viscosity of linseed oil varnish, the solubility in a solvent for ink (AF7 solvent manufactured by Nisseki Mitsubishi Co., Ltd.), and the weight average molecular weight were measured. evaluated. The measurement was performed by the following method, and the results are summarized in Table 1.

Linseed oil varnish viscosity: Resin and linseed oil were mixed at a mass ratio of 1: 2, and the mixture was heated and dissolved, and measured by a falling ball viscometer.

Solubility in Ink Solvent (AF7 Solvent Solubility): The maximum amount of AF7 solvent that can be present without causing cloudiness when the resin is dissolved in AF7 solvent and left at 25 ° C. Resin 1 at the time
It was indicated by the AF7 solvent amount converted per g. Regarding the weight average molecular weight, the result of measuring the molecular weight (in terms of polystyrene) by GPC analysis is shown below.

The results are shown in Table 1.

[0023]

[Table 1]

[0024]

Table 1 Resin 40 parts, soybean oil 20 for each resin
And 40 parts of AF7 solvent were charged into a reaction vessel, and the mixture was stirred and heated while blowing in nitrogen gas, and kept at 200 ° C. for 1 hour to obtain a varnish. When this was cooled to 100 ° C., 1 part of ALCH-50 (manufactured by Kawaken Fine Chemical Co., Ltd.) was added as a gelling agent, and the temperature was raised to 180 ° C.
The mixture was kept warm for a time to obtain a gel varnish.

Next, 60 parts of gel varnish was added with carmine 6B18.
Part was ground with a three-roll mill, and each gel varnish and AF7 were adjusted so that the tack became 6-7 and the flow became 15-18.
Adjusted with No. Solvent to obtain a red ink for testing. Less than

Table 2 shows the properties and evaluation results of each ink. The tack and flow were measured using a digital incometer (manufactured by Toyo Seiki Seisakusho) and a parallel plate viscometer (manufactured by Toyo Seiki Seisakusho).

[0026]

[Table 2]

The evaluation of the ink performance in Table 2 was performed as follows.

Gloss: 0.3 cc of the ink was spread on art paper with an RI tester (manufactured by Mei Seisakusho), dried in a hot air drier at 120 ° C. for 5 seconds, and after 24 hours at room temperature, a gloss meter was used. (Manufactured by Gardner Co.) and the 60 ° specular reflectance was measured.

Emulsification ratio: using Lithotronic (manufactured by Novo Control), 2 g of ion-exchanged water was added to 25 g of ink.
The solution was dropped at a rate of 1 / min, and the emulsification rate at the saturated point was measured.

Amount of misting: When 1.3 cc of ink was rotated at 2,000 rpm for 1 minute per minute by a digital incometer (manufactured by Toyo Seiki Seisaku-sho, Ltd.), the amount of mist scattered below the roll was precisely weighed.

From Table 2, it can be determined that the inks using the resins of Examples 1 and 2 have the same performance as the ink prepared similarly using Comparative Example 1 (conventional rosin-modified phenolic resin). In addition, it is clear that it does not contain any harmful alkylphenol or formaldehyde.
In addition, the resin of Example 2 has no insoluble matter as compared with that of Example 1, so it can be said that it is more excellent as a resin for ink.

[0032]

The resin for offset printing ink of the present invention does not use bisphenol A or alkylphenol, which is suspected of being an environmental hormone (exogenous endocrine disrupting chemical), and has problems in odor and harmfulness. It is synthesized without using formaldehyde. In addition, an ink having the same properties as the conventional rosin-modified phenolic resin can be easily adjusted, and an ink having the same performance as that of the conventional rosin-modified phenolic resin can be obtained with the same formulation.

Continued on the front page (72) Inventor Masanobu Kusumoto 3-8-40 Kitadamiya, Tokushima City, Tokushima Prefecture Inside the Tokushima Plant of Hitachi Chemical Co., Ltd. (72) Inventor Tetsuya Takigawa 3- 8-40 Kitadamiya, Tokushima City, Tokushima Prefecture Hitachi Chemical Polymer Co., Ltd. Tokushima Plant F-term (reference) 4J039 AB08 AE06 AF01 AF03 GA02

Claims (2)

[Claims] 1. A softening point of 120 to 220 obtained by reacting a polymerized rosin (a), an unsaturated dibasic acid (b), a polyhydric alcohol (c) and a polyfunctional acrylate (d).
℃, resin for offset ink with weight average molecular weight of 20,000-300,000 2. The method according to claim 1, wherein the polymerized rosin (a), the unsaturated dibasic acid (b), and the polyhydric alcohol (c) are reacted first, and then the reaction product is reacted with the polyfunctional acrylate (d). For producing resin for offset ink