JP2737564B2 - Watercolor paint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a watercolor paint, and more particularly, to a watercolor paint containing water-soluble hemicellulose as an active ingredient and having good colorability and dispersion stability.

[0002]

2. Description of the Related Art Conventionally, watercolor paints are colored pigments as colorants, colorless extenders such as calcium carbonate and barium sulfate, natural or synthetic water-soluble polymers such as gum arabic, dextrin or carboxymethyl cellulose. It is manufactured by kneading water.

When these watercolor paints are filled in a tube or a container and left for a long period of time, the water-soluble polymer yellows, causing a drawback that the color initially changes to an unexpected hue.

[0004] When a natural plant gum such as gum arabic is used as a water-soluble polymer, it exhibits the highest suitability for coloring and dispersing pigments as a watercolor paint, but its supply is limited by the weather in the producing country. It is easily influenced and fluctuates in price. Recently, there is a demand for a natural vegetable gum that can be supplied stably.

As described above, the water-soluble polymer which is a component of the watercolor paint must be stable in dispersion over a long period of time even when used in the final product, and at present, not all of them are satisfied. .

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to develop a paint which has a stable coloring property and dispersibility over a long period of time and can be supplied stably at low cost.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above points and found that when water-soluble hemicellulose, particularly water-soluble hemicellulose derived from beans, was used as a water-soluble polymer, the colorability and dispersion stability were high. I obtained the knowledge that strong watercolor paints can be obtained. The present invention is based on this finding,
It is completed.

That is, the present invention is a watercolor paint containing water-soluble hemicellulose as an active ingredient.

The water-soluble hemicellulose in the present invention is preferably derived from beans, particularly soybeans, and especially from cotyledons.

The water-soluble hemicellulose can be used with any molecular weight, but preferably has an average molecular weight of tens of thousands to several millions, specifically 50,000 to 1,000,000. . The average molecular weight of the water-soluble hemicellulose is a value determined by an intrinsic viscosity method for measuring the viscosity in a 0.1 M NaNO ₃ solution using standard pullulan (available from Showa Denko KK) as a standard substance. Also, uronic acid is measured by Blumenk
Neutral sugar was measured by GLC method after alditol acetate conversion by the rantz method.

The water-soluble hemicellulose can be extracted from a raw material containing hemicellulose with water, or in some cases, heated and eluted under acid or alkaline conditions, or decomposed and eluted with an enzyme. An example of a method for producing water-soluble hemicellulose is as follows.

[0012] Oil seeds such as soybeans, palms, palms, corns, cottonseed, etc., are usually made from husks without oils and fats, or cereals, such as rice, wheat, etc. be able to. If the raw material is soybean, it is possible to use okara which is a by-product when producing tofu, soymilk, and isolated soybean protein.

These raw materials are prepared under acidic or alkaline conditions, preferably at a pH around the isoelectric point of each protein, preferably 130 ° C. or lower and 80 ° C. or higher, more preferably 130 ° C. or lower.
After heat decomposition at 100 ° C or more, and fractionating the water-soluble fraction,
Water-soluble hemicellulose can be obtained by drying as it is, or by removing the hydrophobic substance or low-molecular substance by activated carbon treatment, resin adsorption treatment or ethanol precipitation treatment and drying.

[0014] For example, gum arabic is used for watercolor paint, but supply is uneasy. Therefore, modified starches have been developed, but they have poor coloring power and are not always satisfactory in pigment dispersion stability.

When the water-soluble hemicellulose of the present invention is used for a water-soluble polymer which is a raw material of a watercolor paint, a more stable dispersion state can be obtained than when gum arabic or modified starch is used.

In the present invention, water-soluble hemicellulose can be used alone as a water-soluble polymer, but by using it in combination with an existing water-soluble polymer, the disadvantages of the existing water-soluble polymer can be compensated. .

Existing synthetic water-soluble polymers include water-soluble acrylic resins, water-soluble styrene-acrylic resins, and water-soluble styrene-maleic acid resins. Further, water-dispersible resin emulsions such as acrylic resin, alkyd resin, vinyl resin, polyester resin, styrene resin, maleic acid resin and urethane resin can also be exemplified as existing effective synthetic polymers.

On the other hand, existing natural product water-soluble polymers include gum arabic, tragacanth gum, carrageenan, xanthan gum, gelatin, sodium casein, guar gum, tara gum, cloth seaweed, agar, furceleran, tamarind seed polysaccharide, karaya gum, troloi, pectin, Sodium alginate, pullulan, gellan gum,
Examples include locust bean gum, albumin such as whey, and various starches. Semi-natural products water-soluble polymers include carboxymethyl cellulose (CMC), methyl cellulose (MC), hydroxyethyl cellulose (HEC),
There are propylene glycol alginate and modified starch typified by soluble starch.

The water-soluble hemicellulose in the present invention comprises:
In some cases, the effect can be further improved by using one or more of the above-mentioned various water-soluble polymers in combination, and the drawbacks of the various water-soluble polymers can be compensated.

The pigment used in the watercolor paint of the present invention may be any solid substance that is hardly soluble in water, and includes general colored pigments and the like, and those using black pigments can be used as ink. As described above, the present invention can be applied to ink, such as a solution, a paste, a solid, and a particle, and to all kinds of watercolor paints.

[0021]

The embodiments of the present invention will be described below with reference to examples, but these are only examples, and the spirit of the present invention is not limited by these examples. In addition, in an example, all parts and% mean a weight basis.

Preparation of soybean hemicellulose Twice the amount of water was added to the raw okara obtained in the step of producing soybean protein isolate, and the pH was adjusted to 4.5 with hydrochloric acid.
Hydrolyzed for 5 hours. After cooling, centrifuge (10000 G x 30
Min), and separated into a supernatant and a precipitate. The precipitate thus separated was further washed with water of an equal weight, centrifuged, and the supernatant was treated with an activated carbon column together with the supernatant, followed by drying to obtain water-soluble hemicellulose (a).

Furthermore, 0.5% of this water-soluble hemicellulose
It was dissolved in saline and the reprecipitation was repeated three times so that the ethanol concentration became 50%. The ion exchange resin (Organo Co., Ltd.)
Desalted using "Amberlite IR-120 B", manufactured by Toshiba, to obtain water-soluble hemicellulose (b).

On the other hand, a water-soluble hemicellulose (c) was similarly obtained without the treatment with an activated carbon column in the above method.

The above results are summarized as follows. Composition ratio (%) ─────────────────────────────────── Component (a) (b) (c) ) ───────────────────────────────── Water 5.71 7.75 5.10 Crude protein 1.93 1.03 5.43 Crude ash 5.29 0.22 5.30 Many Saccharides 87.07 91.00 84.17 ──────────────────────────────── Average molecular weight 178,000 207,000 114,000 ───────── ──────────────────────────

Next, the sugar composition of the water-soluble hemicellulose of (a), (b) and (c) was analyzed by the following method. Uronic acid was measured by the Blumenkrantz method, and neutral sugar was measured by the alditol acetate method using GLC.

The results are as follows. Sugar composition (% by weight) 種類 Types of sugar (a) (b) (C) ───────────────────────────────── Uronic acid 20.4 16.9 19.4 Rhamnose 1.6 2.7 2.1 Fucose 2.7 5.2 3.9 Arabinose 19.9 19.2 23.1 Xylose 6.4 8.4 5.8 Galactose 47.3 40.8 43.4 Glucose 1.8 0.9 2.3 ───────────────────────────────────

Example 1 Permanent Red 4R 20.0 parts (azo red pigment, manufactured by Dainippon Ink and Chemicals, Inc.) Water-soluble soybean hemicellulose (a) 12.0 parts Calcium carbonate 30.2 parts Glycerin 10 0.0 parts Phenol (preservative) 0.2 parts Water 27.6 parts The above components were kneaded three times with a three-roll mill to obtain a red watercolor paint.

Example 2 A red watercolor was obtained in the same manner as in Example 1 except that water-soluble soybean hemicellulose (a) was used instead of water-soluble soybean hemicellulose (a). .

Example 3 A red watercolor paint was obtained in exactly the same manner as in Example 1, except that water-soluble soybean hemicellulose (c) was used instead of water-soluble soybean hemicellulose (a). .

Comparative Example 1 Permanent Red 4R 20.0 parts (azo red pigment, manufactured by Dainippon Ink and Chemicals, Inc.) Arabic gum 20.0 parts Calcium carbonate 30.2 parts Glycerin 10.0 parts Pheno- (Preservative) 0.2 part Water 19.6 parts The above components were kneaded three times with a three-roll mill to obtain a red watercolor paint.

Comparative Example 2 A red watercolor paint was obtained in exactly the same manner as in Comparative Example 1 except that dextrin was used instead of gum arabic.

The watercolor paints obtained in the above Examples and Comparative Examples are applied to a drawing paper (JIS P-3301 drawing paper A) with a paintbrush, and the coloring state of the coating and the spread and unevenness of the paint are monitored. The test (20 panelists) was performed. Further, the watercolor paints obtained in Examples and Comparative Examples
After leaving it in a 0 ° C. constant temperature bath for one month, it was applied to a drawing paper with a paintbrush, dried, and observed for a change in hue.

The results are shown below in comparison. Colored state Unevenness Hue change ──────────────────────────────── Example 1 ◎ ◎ ◎ Trace yellowing ── ────────────────────────────── Example 2 ◎ ◎ ◎ Micro trace yellowing ────────── ────────────────────── Example 3 ◎ ◎ ○ Trace yellowing ─────────────────── ───────────── Comparative Example 1 ◎ ○ ○ Trace yellowing ──────────────────────────── ──── Comparative Example 2 △ △ × considerably yellowing ◎ ◎ extremely good ○ good △ Somewhat bad × Bad

As described above, when water-soluble soybean hemicellulose was used, a watercolor paint having good coloring power, coloring properties, and dispersion stability such as spread and unevenness was obtained.

Example 4 Water-soluble soybean hemicellulose (a) 20.0 parts Phenol 0.4 parts Calcium carbonate 20.0 parts Hansa Yellow 10G 12.0 parts Water 47.6 parts

The above ingredients are kneaded three times in a three-roll mill to produce a yellow watercolor paint paste. The paste was poured into a square dish-shaped container, frozen overnight (−15 to 20).
C), and water was removed by a freeze-drying method to obtain a solid yellow watercolor paint having good water solubility.

Comparative Example 3 Gum arabic 27.0 parts Phenol 0.4 part Calcium carbonate 20.0 parts Hansa Yellow 10G 12.0 parts Water 40.6 parts Except for using the above components, the same procedure as in Example 4 was carried out. A solid yellow watercolor was prototyped, but it was poorly soluble.

[0039]

As described above, when a watercolor paint is produced using water-soluble hemicellulose, the pigment dispersion is stable for a long time even in the final product, and when used for a solid watercolor paint, gum arabic is used. Thus, solid water-based paints having excellent re-dispersibility without becoming poorly soluble in water became possible.

Claims (2)

(57) [Claims] 1. A water-soluble hemicellulose as an effective component containing
No watercolors. 2. The paint according to claim 1, wherein the water-soluble hemicellulose is derived from soybean.