JPS62135546A - Production of carboxymethylcellulose gel - Google Patents

Abstract

PURPOSE:To obtain carboxymethylcellulose gel which is uniform and firm, by mixing carboxymethylcellulose salt with a polyvalent metal salt in a solid phase and then mixing the mixture with water. CONSTITUTION:Carboxymethylcellulose salt (CMC) is thoroughly mixed with a polyvalent metal salt in a solid phase. The mixing ratio is usually 1-100pts. wt. polyvalent metal salt per 100pts.wt. CMC. When the mixing ratio is less than 1, an undissolved lump is liable to be formed when mixed with water, while when the ratio exceeds 100, syneresis occurs and gel cannot be spread throughout the whole mixture so that uniform gel can not be prepd. It is preferred that particles are as fine as possible and mixed as uniformly as possible. The resulting mixture is mixed with water, whereby a uniform hydrous gel can be obtd. The mixing ratio is generally 0.1-100pts.wt. mixture per 100pts.wt. water.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing a uniform hydrogel of carboxymethyl cellulose salt (hereinafter abbreviated as CMC). Specifically, by pre-mixing CMC and Taei metal salt in a solid state and then mixing with water, it is possible to easily obtain a uniform CMC.
The present invention relates to a manufacturing method for obtaining a hydrogel of MC.

(Prior Art) It has been known that CMC is rapidly precipitated or gelled by many polyvalent metal salts. However, in many cases the product is a fibrous precipitate, precipitate or particulate fj
:, lees or solid') formed into a lumpy precipitate, which was completely non-uniform when viewed from the system as a whole, and was far from a homogeneous gel like konjac or burino.

In order to form a uniform gel of synthetic polymers, a method is known in which a gelling agent that is sparingly soluble in water, such as basic aluminum acetate, is used (Japanese Patent Application Laid-Open No. 106598/1983).
), when this method is applied to CMC, the CMC gels on the surface of the gelling agent and becomes a large lumpy gel, which often becomes non-uniform. In addition, there are not many types of polyvalent gold and salts that are poorly soluble in water. Another possibility is to significantly increase the agitation when mixing the gelling agent.
This requires a special powerful stirring device, and furthermore, this method is also quite non-uniform when viewed microscopically, with hard lumpy precipitates being dispersed in fine particles.

As a method to compensate for the drawbacks of these methods, a method is proposed in which CMC is dispersed or saturated in a hydrophilic organic liquid in advance, and then a gelling agent and water are added to obtain a uniform hydrogel (Japanese Patent Laid-Open No. Sho 5).
No. 9-108045), but even the gel obtained by method B is not necessarily satisfactory in terms of gel uniformity and strength. It also has the disadvantage of requiring the use of hydrophilic organic liquids.

(Problems to be Solved by the Invention) In the present invention, W et al. have conducted intensive studies on a method for homogeneous gelation of carboxymethyl cellulose salt, and as a result, they have found that they can achieve a very uniform gelation method without using a special strong stirring device or a hydrophilic organic liquid. discovered a method to generate a strong gel. Furthermore, by using the method of the present invention, it is possible to control the gelation rate, and it is possible to easily create a uniform and strong gel that can be formed into any shape, leading to the completion of the present invention. Ta.

(Means for Solving the Problems) The present invention is a method of mixing carboxymethylcellulose salts and multimetallic salts in a solid state, and then mixing the mixture with water. Further, a uniform hydrous gel of CMC and a polyvalent metal salt can be obtained by the following method.

First, CMC and a polyvalent metal salt are thoroughly mixed in a solid state.

The mixing ratio at this time is not particularly limited as it differs depending on the type of CMC and polyvalent metal salt, but the weight ratio is usually CMC1
00, and the polyvalent metal salt ranges from 1 to 100. If the mixing ratio is less than 1 to CMC 100 of the polyvalent metal salt, it will tend to clump when mixed with water, and if it exceeds 100, it will cause a separation phenomenon and the gel will not spread throughout and even if it collapses, it will not be a uniform gel. I can't make it. Although the mixing method is not particularly limited, it is preferable to make the particles as fine as possible and mix as uniformly as possible. For this reason, a special pulverizer such as a vibration mill or a ball mill may be used, but simply mixing in a mortar is sufficient.

Next, when this mixture is mixed with water, a uniform hydrogel can be easily obtained. At this time, the mixing ratio when mixing this mixture with water varies depending on the use and is not particularly limited, but is generally in the range of 0.1 to 100 parts by weight per 100 parts by weight of water.

In the process of obtaining a uniform hydrous gel of CMC and a polyvalent metal salt using this method, the time and temperature of the mixture from mixing CMC and the polyvalent metal salt in a solid state to mixing with water are as follows: Affects the rate of gelation after mixing with water.

That is, the longer the standing time, the longer the time required for gelation. Furthermore, if the temperature at which the gel is left is high, the time required for gel formation becomes longer. The leaving time in this case is usually applied for 0 to 24 hours, and the leaving temperature can range from low to high temperature, for example -1
Examples include 0 to 300°C.

Utilizing this phenomenon, the time required for gelation can be arbitrarily delayed by treating the mixture of CMC and polyvalent metal salt at an appropriate temperature for an appropriate time before mixing with water.

In practice, it is often convenient for product molding to maintain a fluid state for a while after adding a gelling agent, and it is possible to arbitrarily slow down the gelation of CMC and polyvalent metal salt, which normally proceeds very quickly. is very useful.

If the present invention is used, CMC and a polyvalent metal salt are first mixed in a solid state, and the resulting mixture is heated at an appropriate temperature for an appropriate time, or after being left at room temperature for an appropriate time, water is added. By mixing with CMC, a uniform hydrogel of CMC can be obtained at any gelation rate.

Carboxymethylcellulose salt (C
Examples of MC) include carboxymethylcellulose sodium salt, potassium salt, and ammonium salt.

In addition, the degree of substitution (DS) and viscosity (degree of polymerization) of CMC are not limited. Depending on the use and purpose, you can choose from
can run.

In addition, the polyvalent metal salts used in the present invention include aluminum salts such as aluminum acetate, aluminum sulfate, potassium alum, and aluminum chloride; iron salts such as ferrous chloride, ferric chloride, and ferric sulfate; Cupric chloride, IA sulfate, 7 cupric salts, other inorganic or organic magnesium salts, barium salts, calcium salts, manganese salts, cadmium salts, chromates, titanates, antimonates, etc. Examples include one type or a mixture of two or more types.

Examples of practical applications of the hydrogel obtained using the present invention include bases for poultices, bases for poultices, bases for topical headache/anti-inflammatory/antispasmodic gels, bases for fragrances, and cosmetics. base cream, skin conditioner cream, burnishing cream, cold cream, base for facial makeup, toothpaste, noaching cleaner, permanent waving agent, nail polish, Naka-r Shiroi, blusher, hair dye , eyeliner, pharmaceuticals and cosmetics such as acenolotion,
Calo bills with food such as funon, celery, konnyaku, civil engineering, etc.
A wide range of products can be mentioned, such as anti-sludge agents for oil polling, battery gel electrolytes, electric wire and cable coatings, etc. Hereinafter, a specific explanation will be given according to the examples.Example L Sodium carboxymethyl cellulose Salt (degree of substitution = 1
1,1% aqueous solution viscosity = 1500 cps) 5g and chloride chloride
1 g of iron hexahydrate was thoroughly mixed in a mortar, and after mixing, 2 g of this mixture was added to 100 g of water while stirring lightly with a glass rod, and a uniform hydrous gel was immediately obtained.

Example 2 A mixture of carboxylic 7-methylcellulose sodium salt and ferric chloride 6' salt obtained in the same manner as in Example 1 was mixed and left at room temperature for 2 hours. 2g was taken and 100g of water was added.
When the mixture was added to the water while stirring lightly with a glass rod, the mixture was immediately dispersed uniformly in the water. When this dispersion was poured into a cubic mold having a volume of 2 U and allowed to stand, a very uniform 2 an' cubic shaped hydrogel was obtained after about 3 hours. Furthermore, this gel had excellent mold releasability when taken out from the mold.

Example 3 A mixture of carboxymethylcellulose sodium salt and ferric chloride hexahydrate obtained in the same manner as in Example 1 was heat treated in a dryer at 100"C for 130 minutes, and then 2g was added to 100g of water using a glass rod. When the mixture was added while being lightly stirred, a uniform dispersion was immediately obtained, and after about 12 hours, a very uniform hydrogel was obtained.

Example 4゜Carboxymethylcellulose sodium salt (degree of substitution = 0
．． Mix 5 g of 9.1% aqueous solution (viscosity = 1300 cps) and 4 g of aluminum nitrate nonahydrate L in a mortar, let stand at room temperature (approximately 25°C) for 3 hours, then add 2 g of this mixture to 100 g of water using a glass or stick. After about 12 minutes, a very uniform and transparent agar-like gel was obtained.

Ratio example L Carboxyditylcellulose sodium salt (degree of substitution)
Dissolve 17 g of 1.1% aqueous solution (1,500 cps) in 50 g of water, and 0.3 g of ferric chloride hexahydrate in 50 g of water, and mix both with a glass 1 without stirring lightly. Only a granular gel was obtained.

Claims (1)

[Claims] A method for producing a homogeneous gel, which is characterized by mixing a carboxymethylcellulose salt and a polyvalent metal salt in a solid state, and then mixing the mixture with water.