JPS5811552A - Coloring of shellac with food color - Google Patents

Abstract

PURPOSE:To obtain a colored product resistant to degradation and having stabilized color, by adding microcrystalline cellulose and a pigment uniformly to an alcoholic solution of shellac having acidic pH. CONSTITUTION:Colored microcrystalline cellulose or paste or cake of microcrystalline cellulose colored with an aqueous solution of pigment is added to an alcoholic solution of shellac having acidic pH, and the mixture is homogenized by stirring, shaking, blasting of neutral gas, etc. Microcrystalline cellulose is fine powder obtained by hydrolyzing wood pulp with a mineral acid and removing the most part of the amorphous part. The useful microcrystalline cellulose is those containing the component having a total length of about 60-0.1mu in an amount of >=50% of the microcrystalline cellulose. USE:Printing ink and paint.

Description

[Detailed Description of the Invention] This invention relates to natural resin shellac.
The purpose of this invention is to color shellac or its alcohol solution in an industrially advantageous manner.

Sierra Tsukuha, as is well known, disc, varnish, inr,
It is widely used as an electrical insulating material, sealing wax material, etc.

Since shellac is solid, it is used by dissolving or dispersing it in alcohol or other solvents. Depending on the intended use, pigments are usually uniformly dispersed therein. However, regarding the alcoholic solution of shellac whose pH is on the acidic side...
There are various difficulties in coloring.1 For example: 1) When water is added to it (in the case of coloring with water-soluble dyes), shellac coagulates and settles. (2) If an alcohol-μ insoluble dye is added to this, the entire amount of the dye will precipitate and no coloring will be possible; (2) A dye that is insoluble in acidity cannot be used; and others. The challenge here is to create a method for significantly coloring shellac or its heavier alcohol solution.

This invention is an answer to this problem, and will be described in detail below.

First, prepare an alcoholic solution of % shellac.

-n of this solution is on the acidic side.

The type of alcohol that can be used at this time does not matter, ie, monovalent alcohols and polyhydric alcohols can be used. Items that belong to this include: ethanol/methanol, propatool, cetanol μ
, glycerin, sorbitol, propylene glycol, and others. Water-containing alcohols may be used, and these may be used alone or in combination of two or more. This solution can be used regardless of its shellac concentration, whether high or low.

To this system is added microcrystalline cellulose that has been colored in advance or paste or cake 16 that is prepared by coloring microcrystalline cellulose with an aqueous solution of a dye.

Microcrystalline cellulose is obtained by hydrolyzing wood pipes using mineral acids to remove most of the amorphous portion, leaving the crystalline portion of 7IC@shi in the form of a fine powder. A useful microcrystalline portion for this invention is one containing a majority of the fiber length in the range of about 60 to 0.1 μm. The amount used for this is
0.0 to 40% (by weight, same hereinafter) of the shellac alcohol solution, regardless of whether it is a synthetic pigment or a natural pigment, is generally one that is insoluble in water or alcohol under acidic conditions;
■There are many disadvantages such as the hue fluctuates depending on the pH and ■there are many substances with low solubility, but by contacting with microcrystalline cellulose, the hue can be stabilized and the alcohol solution of shellac can be used without deteriorating its quality. can do. In the present invention, pigments in the form of fine powder or those dissolved in water on the neutral or alkaline side can also be added and used.

A mixed system of shellac and alcohol into which microcrystalline cellulose previously colored with a pigment is mixed is made homogeneous. To make it homogeneous, stirring, shaking, blowing in neutral gas, and other conventional methods are followed.The products obtained in this step are used as various colored inks and colored paints. Further, by drying this liquid system, a colored shellac product with the desired consistency can be obtained.

Here, the present invention achieves this objective.

Some of the functions and effects of this invention will be explained below.

■When water is added to an alcohol solution whose pH is on the acidic side, shellac is coagulated as described above, but in this invention, the coloring agent is a coloring agent in which the pigment is dispersed in water. Even if water is used, the shellac will not coagulate.

- Shellac, once coagulated and precipitated, cannot be redissolved in this system, but this invention does not encounter any of these difficulties.

■There is no adverse effect on the hue, brightness, and saturation of the added pigment.

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 Red gravure ink 00g 111F Crystal Seven loin, red cabbage extracted pigment liquid, and citric acid are stirred and mixed to a pH of 2.5 to 8. Once everything is mixed homogeneously, pour it into the pre-dissolved alcoholic shellac solution and mix thoroughly. If necessary, apply an appropriate filter to remove excess microcrystalline cellulose. The dye solution obtained in this manner remained stable, and no deterioration of the ink occurred.

Example 2゜Orange silk screen ink 00g Norbixin potassium salt solution and microcrystalline cellulose were mixed by stirring well. Gradually pour into the alcohol solution of shellac, which has been previously dissolved in ethyl alcohol, and mix the whole thing. Next, add propylene glycol and mix the whole thing.

In the thus obtained silk screen ink, the alcohol solution of shellac did not undergo deterioration, and a stable orange hue was obtained with norbixin potassium salt.

Example 8゜ Paint 00g Add 0.1% sulfuric acid to carminic acid aqueous solution to make it acidic.

Add microcrystalline cellulose and knead into a cake.

Stir and disperse in the alcoholic shellac solution. You can make red paint.

Example 4 Colored Shellac 00g Mix Food Red No. 2 aqueous solution and microcrystalline cellulose well. Stir and disperse in the alcoholic shellac liquid. After the alcohol has evaporated, it can be crushed and used if necessary.

applicant Sanei Chemical Industry Co., Ltd.

Claims (1)

[Claims] (1) To color shellac, microcrystalline cellulose and pigment are homogeneously added to a homogeneous mixture of an alcoholic solution of shellac whose pJ (is on the acidic side) and microcrystalline cellulose. A method for coloring lizards, which is characterized by
A printing ink consisting of a homogeneous mixture of acidic microcrystalline cellulose and pigment. (S is an alcoholic solution of shellac, and the PH of
A paint consisting of a homogeneous mixture of microcrystalline cellulose, which is on the acidic side, and pigment.