JPS5874763A - Composition for printing ink - Google Patents

Abstract

PURPOSE:To improve storage stability, film properties, etc., by blending a maleic anhydride adduct of a vinyl-substd. arom. compd/conjugated diene compd. block copolymer with a printing ink consisting of an inorg. pigment, an org. solvent, etc. CONSTITUTION:A vinyl-substd. arom. compd. such as styrene or vinyltoluene and a conjugated diene compd. such as butadiene or isoprene are copolymerized to prepare a vinyl-substd. arom. compd./conjugated diene compd. block copolymer. This copolymer is reacted with maleic anhydride in the presence of an azobis type radical polymn. catalyst such as azobis isobutyronitrile to prepare a maleic anhydride adduct. The maleic anhydride adduct, an inorg. pigment such as titanium oxide, an org. solvent such as xylene and, if necessary, a high- molecular compd. such as an epoxy resin are mixed together to obtain the desired printing ink.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing ink composition, particularly a printing ink composition containing a maleic anhydride adduct of a vinyl-substituted aromatic compound-conjugated diene compound Zollock copolymer.

BACKGROUND ART Vinyl-substituted aromatic compound-conjugated diene compound Zoroku copolymers (hereinafter referred to as block copolymers) have been known as compositions for paints or printing inks.

Solvent-based paints containing this block copolymer have excellent chemical resistance and thixotropic workability, while solvent-based printing inks containing secondary layer color pigments provide matte, desirable color tone and mechanical properties. It has excellent strength.

However, such paints or inks (1) cannot provide high gloss, (2) have low adhesion to the object to be coated, (3) tend to cause pigments to settle, and (4) have problems with other resins. Low degree of freedom in formulation due to poor compatibility: (51II
There are drawbacks such as the inability to obtain solvent-based paints with high pigment concentration due to poor dispersibility.

In addition, polar molecules made of elements such as oxygen and nitrogen are bonded to the molecular ends of the vinyl-substituted aromatic compound-conjugated diene compound Zoroku copolymer, and paints and printing materials containing the modified Zoroku copolymer as a main component are used. Although resins for ink have been proposed, they have problems with pigment dispersibility and compatibility with other polymeric compounds.

The present invention solves these drawbacks by combining a maleic anhydride adduct of a vinyl-substituted aromatic compound-conjugated diene compound block copolymer maleated in the presence of a radical-generating catalyst with an inorganic pigment, an organic solvent, or a polymeric compound. 9. Printing inks using these resins have excellent storage stability and physical properties of the coating film, and can also be used as HD, especially high pigment concentration paints, so-called no-build paints. .

In the present invention, vinyl-substituted aromatic compounds include mineral styrene, vinyltoluene, α-methylstyrene, etc., and conjugated diene compounds include butadiene, isoprene, etc. Vinyl-substituted aromatic compound - conjugated diene compound! The lock copolymer is a two-component or three-component Zorock copolymer obtained by combining these monomers, and among these, the one particularly preferably used in the present invention is expressed by the following general formula %. %) (However, B is a polymer block consisting essentially of a styrene compound and has a styrene ratio of more than 80, and B is essentially consisting of a conjugated diene compound. The polymer block is a styrene compound-conjugated diene compound block copolymer (hereinafter referred to as a block copolymer) having a linear, radial or star-shaped structure (n represents 1 to 20). - These block copolymers can be easily reacted with maleic anhydride to form maleate, and unreacted maleic anhydride can also be eliminated by reacting with a vinyl compound.

The maleic anhydride adduct of the vinyl-substituted aromatic compound-conjugated diene compound block copolymer used in the present invention (hereinafter referred to as maleated block copolymer) can be prepared by, for example, converting the block copolymer described above into an azobis-based radical polymerization catalyst. It is obtained by reacting with maleic anhydride in an organic solvent in the presence of.

In addition, the inorganic pigments used in the present invention are those used in ordinary paints and printing inks, such as titanium oxide, iron oxide, zinc oxide, lead oxide, calcium carbonate, aluminum, carbon black, and 7-talocyanine blue. Examples include powders such as

The organic solvent used in the present invention preferably contains benzene, toluene, or xylene, and the amount of the organic solvent used is preferably 30 to 90% by weight in the composition.

Further, the polymer compounds used in the present invention include alkyd resins, epoxy resins, melasan resins, acrylic resins, petroleum resins, chlorinated paraffins, rosins, and the like. Although it is difficult to specify these blending ratio lines depending on the intended printing ink in the paint, in general, the amount of inorganic pigment to the maleated Zoroku copolymer is 300 parts by weight or less, preferably 100 to 200 parts by weight. - but not limited to these. Regarding the polymer compound, the amount is preferably 5 to 200% by weight based on the maleated Zoroku copolymer, preferably 10 to 150% by weight, and more preferably 30 to 120% by weight.

As explained above, according to the present invention, a maleated Zorok copolymer and a pigment maleated in the presence of a radical generating catalyst,
The composition for printing ink contains an organic solvent or a polymer compound in these, but when the product of the present invention is blended into the printing ink, it has improved chemical resistance, workability, mechanical strength, adhesion, pigment dispersibility, It has excellent compatibility with resins, and has the advantage that the printed matter has excellent coating film properties.

The present invention will be further explained below with reference to Examples.

Example 1 Production of maleated styrene-butadiene block copolymer 35 g of a styrene-butadiene block copolymer having an average molecular weight of 7 x 104, type AB, and containing 15% by weight of detadiene and xylene 65II were prepared in an internal volume of 200 d The mixture was placed in a separable flask and stirred to form a uniform solution containing the copolymer. The viscosity of this solution is 2 at a temperature of 20°C.
It was 50 cps.

To 100 parts by weight of the copolymer in this solution, 10 parts by weight of maleic anhydride and 1 part by weight of abbisisobutyronitrile as a catalyst were added and stirred at a temperature of 80° C. for 3 hours under an air atmosphere. The residual maleic anhydride in the reaction solution was determined by chromatography to determine the reaction rate, which was found to be 87%. The viscosity of this solution is 95 at a temperature of 20°C.
It was 0 cps.

For the production of pigment dispersion, add 1 liter of a xylene solution containing 1.0% by weight of styrene-butadiene solox copolymer maleate as a solid content.
ll Ll. 3. Take 301 d of this solution into a graduated test tube with an internal volume of 40 d, and add thoroughly dried titanium oxide pigment (Rutile R-810J manufactured by Ishihara Sangyo Co., Ltd.).
Add 09 and stir for about 1 hour using a ridgeline mill.
Mix to disperse pigment.

Immediately after dispersion, the test tube was placed vertically and allowed to stand, and the state of precipitation of the pigment in the copolymer solution was examined.

In addition, in comparison to the styrene-butadiene block copolymer used in Example 1 for rounding off the comparison, a cal? In Example 1, a xyl group-added polymer and a styrene-butadiene block copolymer were used as original copolymers without maleation treatment and terminal carboxylation.
Titanium oxide was dispersed using the same method as above. These results are shown in Table 1.

Table 1 (Note) Evaluation Example 2 The Zoroku copolymer maleate produced in Example 1 was dissolved in xylene to prepare a xylene solution containing 10% by weight of solids.Separately, other resins were used to investigate the compatibility of various types shown in Table 1. A xylene solution with a solid content of 10 wt.

Place 3Qil of a 10% xylene solution of the block copolymer and 10Rj of a 10% xylene solution of another resin to check compatibility into an Erlenmeyer flask with an internal volume of 10011J, and stir and mix thoroughly using a shaker. did. The obtained mixed solution of the 9-Zoroku copolymer and other resins was poured onto a clean transparent glass plate, and the solvent was removed by natural drying to prepare a thin casting film. Casting film after drying @
The compatibility of various Zoroku copolymers with other resins was investigated by observation using a photomicroscope and an optical microscope.

The results are shown in Table 2. As is clear from Table 0, among the styrene-butadiene block copolymers of the same composition and structure, (1) unmodified product, (2) terminally carboxylated product, (3
) The compatibility with other resins of the maleated modified product is almost the same for the unmodified product and the product with terminal carboxylation, and the compatibility with other resins is not very good. On the other hand, the maleated product had significantly better compatibility with various other resins.

Example 3 In Example 1, the maleated block copolymer obtained was mixed in the proportions shown in Table 6 and mixed for 20 hours using a ball mill to prepare an ink.

For comparison, a growing ink was prepared in the same manner using the styrene-butadiene block copolymer used as the raw material in Example 1.

Table 6 Ink formulation The obtained ink was placed in a test tube (9), the tube was tightly capped, and allowed to stand to examine stability. As a result, the ink using the maleated styrene-butadiene block copolymer was stable without any precipitation even after one month. On the other hand, ink produced using a block copolymer that has not been modified with maleation is 1
After a week, the mixture separated into three phases: the upper phase was a colorless transparent liquid, the lower phase was a color developing solution, and a white precipitate was formed at the bottom of the test tube.

Patent applicant Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] A maleic anhydride adduct of a vinyl-substituted aromatic compound-conjugated diene compound block copolymer obtained by reacting maleic anhydride in the presence of a radical-generating catalyst with an inorganic pigment, an organic solvent, or a polymer compound contained therein. Composition for printing ink