JPH0138403B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing water-soluble hydroxyethyl cellulose, and more specifically, the present invention relates to a method for producing water-soluble hydroxyethyl cellulose, and more specifically, in a slurry state of a cellulose raw material in a medium consisting of an organic solvent and water, an alkali is applied to produce alkali cellulose. At the same time, a surfactant is added.
The present invention relates to a process for producing hydroxyethyl cellulose which, by subsequent reaction with ethylene oxide in the presence of a surfactant, has significantly improved visibility of an aqueous solution of the product. Generally, the production of hydroxyethylcellulose is
Lower aliphatic alcohols such as isopropyl alcohol (IPA) and tertiary butyl alcohol (TBA),
The process starts by reacting a cellulose raw material with an alkali in a slurry state in a mixed solution of water and an alkali to form alkali cellulose. In the process of producing alkali cellulose, the state of the solution phase is such that the lower aliphatic alcohol and the alkaline aqueous solution are not compatible with each other, so they are reacted with the cellulose raw material while remaining separated into two layers. Uniform permeation of alkali into cellulose does not necessarily proceed smoothly. Furthermore, in the subsequent reaction with ethylene oxide, the reaction proceeds similarly in a heterogeneous system, so conventional techniques have limitations in reducing the turbidity and suspended matter of the aqueous solution, which are important properties of the final product. Although it has excellent properties, it has the disadvantage that it is difficult to obtain. As a result of extensive research into a method for producing hydroxyethylcellulose that has significantly improved solubility characteristics in aqueous solutions of hydroxyethylcellulose, the present inventors discovered that when producing alkali cellulose, a surfactant was added to increase the permeability of alkali into cellulose. It has been found that this objective can be achieved by reacting alkali cellulose with ethylene oxide at a high temperature and subsequently in the presence of a surfactant. The raw material cellulose used in the present invention may be any material commonly used in chemical reactions, such as wood pulp or linter. Further, it is desirable that the raw material cellulose is pulverized by a pulverizer to a size that allows easy stirring of the slurry prior to the reaction. The alkali used may be sodium hydroxide, potassium hydroxide, or lithium hydroxide, but sodium hydroxide is usually used industrially. In carrying out the present invention, the preferred reaction preparation composition and operating conditions are such that the total weight of organic solvents such as isopropyl alcohol (IPA) and butyl alcohol (TBA), which are dispersion media, and water is 5 to 5% relative to the cellulose. In a 15x slurry system, water/
When the weight ratio of cellulose is in the range of 1.5 to 3.0 and the weight ratio of alkali/cellulose is in the range of 0.25 to 0.50, the surfactant is 0.1 to 10% by weight, preferably 0.2 to 1% by weight based on the total weight of the organic solvent and water. % by weight and stirred and mixed for 30 to 200 minutes at a reaction temperature of 10 to 40°C to produce alkali cellulose. Subsequently, 0.8 to 1.2 parts of ethylene oxide may be added to 1 part of cellulose, and the reaction may be carried out at a reaction temperature of 30 to 80°C for 1 to 4 hours. The surfactants used in the present invention include sodium alkylnaphthalene sulfonate, sodium lauryl sulfate, sodium alkylbenzene sulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenol ether sulfate, sodium alkylnaphthalene sulfonate, and sodium alkylnaphthalene sulfonate. Examples include, but are not limited to, anionic, nonionic, and cationic surfactants such as oxyethylene alkyl phenol ether and alkyl trimethyl ammonium chloride. The surfactant can be added by adding the surfactant to a mixture of organic solvent and water, stirring and dispersing the cellulose, and then dropping an aqueous alkali solution, or stirring cellulose to the mixture of organic solvent and water in advance. Either a method of dispersing the cellulose and dropping an aqueous alkali solution in which a surfactant is dissolved, or a method of dispersing the cellulose in a mixed solution of an organic solvent, water, a surfactant, and an alkali while stirring can be adopted. The present invention will be explained below with reference to Examples and Comparative Examples. Parts represent parts by weight. Comparative Example 12.8 parts of tertiary butyl alcohol and 2.5 parts of a 12.7% aqueous sodium hydroxide solution were added to a 1 separable flask equipped with a stirrer, mixed, and mixed with linter 1.
of the mixture was added, and the arcelification reaction was carried out at 20°C for 60 minutes with stirring. Next, add 0.95 parts of ethylene oxide to 10
After mixing for 3 minutes, the hydroxyethylation reaction was carried out at 50 to 75°C for 3 hours. After neutralizing the reaction product with acetic acid, the reaction product was filtered, washed twice with a methanol/acetone mixture, and then separated and dried. The viscosity of the obtained 1% aqueous solution of hydroxyethylcellulose is
3600cps, transparency measured by JIS method (K0102)
It was 140mm. Example 1 13.6 parts of tertiary butanol (94.6% by weight, balance water) and 0.045 parts of sodium polyoxyethylene lauryl ether sulfate (number of moles of oxyethylene n = 20) were added to a flask equipped with a stirring device, and pulverized in advance. 1 part of linter was added and mixed well. Add to this 18.3% sodium hydroxide aqueous solution
1.75 parts were added dropwise over about 10 minutes. The amount of surfactant added to the total amount of solvent and water is 0.3% by weight.
Stirring was continued for 60 minutes to form an alkali cellulose, and then 0.95 parts of ethylene oxide was reacted at 50 to 75° C. for 3 hours, followed by post-treatment according to the method of the comparative example. 1% of the resulting hydroxyethyl cellulose
The viscosity of the aqueous solution was 3300 cps, and the transparency measured by JIS method was 440 mm, which was significantly improved compared to that obtained in the comparative example. Example 2 Hydroxyethyl cellulose was produced in the same manner as in Example 1, except that 0.045 parts of sodium polyoxyethylene lauryl ether sulfate (oxyethylene mole number n=50) was used as a surfactant. The viscosity of the obtained 1% aqueous solution of hydroxyethylcellulose was 3560 cps, and the transparency was 520 cps.
mm, and was significantly clearer than that obtained in the comparative example. Example 3 1 part of pulverized linter is added to 13.6 parts of tertiary butyl alcohol (94.6% by weight, balance water) and stirred well. To this, 1.74 parts of an 18.6% sodium hydroxide aqueous solution containing 0.015 parts of sodium polyoxyethylene octyl phenol ether sulfate was added dropwise over 60 minutes to obtain alkali cellulose, and then 0.98 parts of ethylene oxide was added and the reaction was carried out at 50 to 75°C for 3 hours. It was then post-treated by the method of Comparative Example. The amount of surfactant added to the solvent and water is 0.1% by weight.
The viscosity of the 1% aqueous solution of the obtained product is 3900 cps,
The visibility according to JIS method was 400mm. Hydroxyethyl cellulose with significantly improved transparency compared to the comparative example was obtained. Examples 4 to 11 Hydroxyethyl cellulose was produced in the same manner as in Example 1 except that the various surfactants shown in Table 1 were used as surfactants. The results are shown in Table 1, and the properties of the 1% aqueous solution of the obtained product showed extremely excellent clarity compared to that obtained in the comparative example. 【table】

Claims (1)

[Claims] 1. A method for producing hydroxyethyl cellulose, which comprises reacting a cellulose raw material with an alkali in a slurry state in a medium consisting of an organic solvent and water to produce alkali cellulose, and subsequently reacting the alkali cellulose with ethylene oxide,
1. A method for producing hydroxyethyl cellulose, which comprises carrying out an alkali cellulose production reaction and a hydroxyethylation reaction in the presence of a surfactant.