JPS581151B2 - Ganryo no Ketsushiyo Seishitsu Henkanhouhou - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for converting the crystalline properties of pigments with a specific structure.

In the invention of Japanese Patent Publication No. 54-11820, the applicant of this application has
We have developed a new crystal modification of a yellow pigment (hereinafter referred to as α-1 type pigment) represented by the structural formula described in the claims section and its excellent special performance.

The present invention provides an improved method for producing the above-mentioned novel crystal modified pigment (hereinafter referred to as β-type pigment).

The present inventor disclosed β in the invention in Japanese Patent Application No. 50-11907.
- As a result of intensive research to improve the production method of -type pigments, α-
It has been discovered that the conversion temperature can be lowered by making aromatic carboxylic acid present when converting the crystal properties from the β-form to the β-form, and that the conversion can be carried out very smoothly and quickly. The invention has been completed.

To explain the present invention in detail, the α-type pigment used in the present invention is a yellow pigment known from Japanese Patent Publication No. 34-4488, and its crystallinity can be seen in the X-ray diffraction diagram under the diffraction conditions described below. , diffraction angle (2θ) approximately 9.8°, 12.5°, 2
It exhibits characteristic diffraction peaks at 1.8°, 25.4°, and 27.7°, and hitherto no other pigments with crystalline properties have been known.

Aromatic carboxylic acids used in the present invention include, for example, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, naphthoic acid, or anhydrides thereof, halogen-substituted, nitro-, methyl-, and methoxy-substituted carboxylic acids. trimellitic acid is most preferred.

The amount of these carboxylic acids used is about 0.1 to 100 parts by weight, preferably about 1 to 50 parts by weight, per 100 parts by weight of the α-type pigment.

The method of the present invention involves uniformly mixing the above α-type pigment and aromatic carboxylic acid,
This is done by heating at 0 to 300°C for several hours.

In order to prevent thermal deterioration of the pigment, this method is preferably carried out in an inert atmosphere such as a nitrogen stream.

In contrast to these dry heat methods, the above reaction may be carried out in various solvents.

A solvent whose boiling point is 150°C or higher, and aromatic chlorinated benzene, nitrobenzene, nitrotoluene, naphthalene, chlornaphthalene, biphenyl, dimethyl phthalate, dibutyl phthalate, etc. are preferable, and formamide, dimethylformamide, dimethyl sulfoxide, dimethyl acetamide, etc. etc. can also be used.

The amount of these solvents used is, for example, about 0.1 to 30 parts by weight per 1 part by weight of the α-type pigment and aromatic carboxylic acid.

The β-type pigment of the present invention obtained as described above is
As disclosed in No. 0-11907, when the pigment particles have different appearances and X-ray diffraction is performed under the following conditions, the diffraction angles (2θ) are approximately 10.2°, 22.7°, and 26.0°. ，
It shows characteristic diffraction peaks at 26.5°, 28.3°, etc.

X-ray diffraction conditions Target Cu Scan Spee
d2(2θ/min) Filter Ni
Chart Speed 20mm/min) Voi
stage30Kv Angle range5~
35(2θ)Current 10mA Di
v Slit 1nFull Scale 800C.
P. S. Scat Slit 1/2nTime C
onst 2sec. Rec. Slit 0.2
The mm measuring device is a DX type X-ray diffraction device manufactured by JEOL Ltd.

When the above-mentioned β-type pigments having crystalline properties are used for melt color molding of polyolefins, particularly medium and low pressure polyethylene, colored products with excellent dimensional stability can be obtained.

On the other hand, when an α-type pigment is used, the molded product undergoes significant deformation and cannot be used as a coloring agent.

Details are as disclosed in Japanese Patent Application No. 11907/1983.

Next, the present invention will be specifically explained with reference to Examples.

Example 1 100 parts of α-type pigment represented by the structural formula and 1 part of trimellitic acid
0 parts were mixed uniformly and heated and left standing at about 300° C. for 2 hours in a hot air dryer.

The obtained pigment is β-type, and is patent application No. 11907/1989.
As described in the specification, when medium-low pressure polyethylene was colored and molded into a container using the pigment, a colored product with stable dimensional accuracy without deformation was obtained.

Example 2 100 parts of α-type pigment and 10 parts of trimellitic acid were uniformly mixed and heated at about 200° C. for 2 hours in a closed reactor equipped with a stirrer.

Thereafter, it was cooled, washed with methanol, and dried to obtain a β-type pigment having the same effect as in Example 1.

Example 3 10 parts of α-type pigment and 0.5 part of trimellitic acid
When the mixture is added to nitrobenzene and heated at about 185 to 190°C, the viscosity of the reaction mixture increases rapidly in about 30 minutes.

The β-
A type pigment was obtained.

Example 4 A β-type pigment was obtained in the same manner as in Example 1 using 100 parts of an α-type pigment and 20 parts of pyromellitic acid.

Example 5 Parts of α-type pigment IO and 1 part of pyromellitic acid were added to 100 parts of dibutyl phthalate to obtain a β-type pigment in the same manner as in Example 2.

Claims (1)

[Claims] 1. A method for converting the crystalline properties of a pigment, which comprises heat-treating a pigment represented by the following structural formula in the presence of an aromatic carboxylic acid.