JPS62151402A - Production of carboxyalkyl hydroxyalkyl cellulose - Google Patents

Abstract

PURPOSE:To obtain the titled compound having improved resistance to salt water, by converting cellulose into an alkali cellulose in isopropanol in a specific concentration under specific condition and hydroxyalkylating and carboxyalkylating the resultant alkali cellulose. CONSTITUTION:A mixed solvent of isopropanol (hereinafter abbreviated to iPA) and water containing 80-87wt%, based on the total of the iPA and water if first used in an amount of 2-7 times based on cellulose. The cellulose is reacted with an alkali in a molar amount of 1-1.5 times based on the anhydroglucose units of the cellulose to give an alkali cellulose, which is then carboxyalkylated and hydroxyalkylated with an etherifying agent to afford the aimed compound. As for the etherifying agent, e.g. monochloroacetic acid, is used for carboxyalkylation and, e.g. ethylene oxide, is used for hydroxyalkylation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing carboxyalkylhydroxyalkyl cellulose having good salt water resistance.

(Prior art) Conventional methods for producing carboxyalkylhydroxyalkyl cellulose having both a carboxyalkyl group and a hydroxyalkyl group as substituents are described in US Pat.
As shown in No. 18632, it is known that C3 to C4 aliphatic alcohols, dioxane, tetrahydrofuran, etc. are used as reaction solvents for carboxyalkylation and hydroxyalkylation. In particular, isopropanol is used, but the reaction is carried out in a general seed form, and the cellulose used is cellulose whose fibers have been cut using a cutting mill, etc., and the total ratio of solvent and water used to cellulose is 8. ~15 parts by weight.

(Problems to be Solved by the Invention) When performing the above reaction using isopropanol, there are many side reactions between isopropanol and alkylene oxide, which is a hydroxyalkylating agent, and the utilization rate of alkylene oxide is low. However, this product has a disadvantage in that it cannot be used as a product with good salt water resistance, which is necessary for use in petroleum polling.

The object of the present invention is to use isopropanol as a solvent to improve the utilization rate of alkylene oxide and to obtain a carboxyalkylhydroxyalkyl mixed cellulose ether having excellent salt water resistance. In the present invention, "good salt water resistance" means that the material has excellent solubility in salt water and dissolves transparently.

As a result of intensive research, the present inventor has found that carboxyalkylhydroxyalkyl cellulose with excellent salt water resistance can be obtained by alkylating under specific conditions using isopropanol at a specific concentration, followed by hydroxyalkylation and carboxyalkylation. Based on this knowledge, the present invention has been completed.

(Means for Solving the Problems) That is, the present invention provides carboxyalkylhydroxyalkyl, which is produced by treating cellulose with an alkali in a mixed medium of isopropanol and water, and then reacting the alkali cellulose with an etherification agent. In the method for producing cellulose, a mixed medium in which the ratio of impropanol to the total of isopropanol and water is 80 to 87% by weight is used 2 to 7 times the weight of cellulose, and the ratio of impropanol to the total of isopropanol and water is 2 to 7 times the weight of cellulose. Production of carboxyalkylhydroxyalkyl cellulose with good salt water resistance, which is characterized by preparing alkali cellulose using 1.5 times the mole of alkali, and then carboxyalkylating and hydroxyalkylating the alkali cellulose with an etherification agent. It is the law.

The raw material cellulose used in the present invention may be any material commonly used in chemical reactions, such as wood pulp or linter. Moreover, it is preferable to use the raw material cellulose that has been crushed using a hammer mill or the like prior to the reaction.

In the present invention, cellulose is first treated with an alkali in a mixed medium consisting of isopropanol and water to produce alkali cellulose. A range of 87% by weight is preferred. This mixed medium is preferably used in an amount of 2 to 7 times, preferably 3 to 6 times, the weight of cellulose.

Various alkalis can be used as the alkali, such as caustic soda, potassium hydroxide, and lithium hydroxide, but it is preferable to use caustic soda from an industrial perspective.

Caustic soda requires 1.0 mol or more per anhydroglucose unit of cellulose in order to react uniformly with cellulose, and it is increased depending on the desired degree of carboxyalkylation, but the effectiveness of haloalkyl carboxylic acid, which is a carboxyalkylating agent In order to increase the utilization rate, it is preferable to use as little as possible, and in the range of the degree of carboxyalkyl substitution D S 0.7 or less, which is the objective of the present invention, the amount of caustic soda is 1.5 per anhydroglucose unit of cellulose used in the reaction. It is sufficient to use less than twice the molar amount.

Among the etherification agents used in the present invention, haloalkylcarboxylic acids or salts or esters thereof are used as the carboxyalkylation reactants. For example, monochloroacetic acid, sodium monochloroacetate, ethyl ester of monochloroacetic acid, leupropyl, isopropyl, lupropyl, isobutyl, tertiary butyl ester, etc.
Examples include α-chloropropionic acid, salts thereof, and esters. In addition, alkylene oxides such as ethylene oxide, propylene oxide, and various butene oxides are used as reactants for hydroxyalkylation.

The order of the carboxyalkylation reaction and the hydroxyalkylation reaction is not particularly limited, and they may be carried out separately or simultaneously, but it is preferable to perform the carboxyalkylation after the hydroxyalkylation because the efficiency of the alkali used is better. is desirable.

The reaction is carried out using a reactor having a twin-shaft stirring blade, and the arcelization is carried out by stirring and mixing for 20 to 200 minutes at a reaction temperature of 5 to 40°C. Subsequently, a hydroxyalkylation reaction and a carboxyalkylation reaction are carried out separately or simultaneously in a conventional manner to obtain carboxyalkylhydroxyalkylcellulose.

The degree of substitution of the carboxyalkylhydroxyalkyl cellulose produced by the method of the present invention is generally such that the carboxyalkyl substitution degree DS is 0.01 to 0.7, preferably O, O.
S ~ 0.65, and the degree of hydroxyalkyl substitution MS is 01 or more, preferably 0.2 to 5.0.

(Effects of the Invention) When produced by the method of the present invention, not only the utilization rate of alkylene oxide is higher than that of the slurry method in which the reaction medium is used 8 to 15 times by weight based on cellulose, but also the solubility in salt water is improved. Because of its excellent properties, it is particularly useful as a cement hardening retardant and dehydration reducing agent in cementing, petroleum poling, and civil engineering poling.

(Example) The present invention will be described in detail below with reference to Examples.

The properties of carboxyalkylhydroxyalkyl cellulose (1) degree of substitution (degree of carboxyalkyl substitution DS, degree of hydroxyalkyl substitution MS) and (2) transparency are measured and evaluated as follows.

(1) Substituted carboxymethyl hydroxyethyl cellulose (hereinafter referred to as C
This will be explained using an example of MHEC (abbreviated as MHEC).

Precisely weigh CMHECIF, put it in a platinum crucible or magnetic crucible, incinerate it at 600℃, titrate the sodium oxide produced by the ashing with IN sulfuric acid using phenolphthalein as an indicator, and calculate the titration amount A ``l using the following formula. Enter and calculate.

-CH2COON a%=O681xAxf, hydroxyethyl content (CH2CH20-%) It was carried out in the same manner as the Morgan method for hydroxyethylcellulose.

CHz COON a content (%) is X, -CI (2CH
When the 2-0-content (%) is y, the degree of carboxymethyl substitution is 81-80 Cellulose 1
The visibility of a wt% aqueous solution under a certain light source is expressed by the height of the liquid column, and is a method commonly used in the industry. Transparency decreases depending on the part, swelling gel body, etc., and the transparency value becomes smaller. Therefore, the more uniform the reaction, the greater the transparency.

As a measure of solubility in saline, the clarity of a 1% solution dissolved in 4% saline was measured in the same manner as for an aqueous solution.

Example 1: Isopropanol 84 was added to a mixer with two-shaft stirring blades.
0g and 50g of water, 54.3g of caustic soda and 97.2g of water
,! Add a caustic soda water bath solution dissolved in i+ and crush the pulp using a hammer mill (degree of polymerization: approximately 700, moisture content: 6%)
212.8g of the mixture was added, and the mixture was stirred at 15°C for 1 hour. In this case, the ratio of the total of isopropanol and water to cellulose is 5.0 times by weight (K!i, referred to as magnification)
The ratio of isopropanol to the total of isopropanol and water is 84%.

Caustic soda is 11 times mole per anhydroglucose unit of cellulose.

After the alcelization, 948 g of ethylene oxide was added, the temperature was raised, and the reaction was carried out at 60°C for 15 hours and at 67°C for 1 hour.

Next, 583 g of monochloroacetic acid, 60 g of isopropanol
g of the mixed solution was added, and after raising the temperature, the mixture was reacted at 70° C. for 1 hour. After the reaction, it was cooled, neutralized with acetic acid, deliquified, and diluted with methanol/
It was washed twice with 5 kg of an aqueous methanol solution of water=85/15.

Hydroxyethyne-substitution degree N, i S = 1.04, carboxymethyl fi conversion degree DS 2043.1% aqueous solution dust of the generated C M HE C is 130 C1)S,
The transparency of the 1% aqueous solution was 650 mm or more, and the transparency of the 1% solution when dissolved in the 4% saline solution was 480 mm. Furthermore, the effective utilization rates of ethylene oxide and monochloroacetic acid were 59.6% and 86%, respectively.

Examples 2-3, Comparative Examples 1-2 The same procedure as in Example 1 was carried out except that the ratio of isopropanol to the total of isopropanol and water during arcelization was changed.

The results are shown in Table 1 together with the results of Example 1.

Example 4゜Isopronol 7 was added to a mixer with two-shaft stirring blades.
38I and 692g of water, 543g of caustic soda and 80y of water
Pulp (degree of polymerization: approx. 700, water content: 6%) is prepared by adding an aqueous solution of caustic soda to the pulp and crushing it with a hammer mill.
212.89 was added and stirred at 15° C. for 1 hour. In this case, the ratio of the total of isopropanol and water to cellulose is 4.5 times by weight (liquid magnification and °C.), and the ratio of isopropanol to the total of isopropanol and water is 82%.

Caustic soda is 11 times mole per anhydrous glucose unit of cellulose.

After arcelization, ethylene oxide 94.8,! 9 was added, the temperature was raised, and the mixture was reacted at 60°C for 1.5 hours and at 67°C for 1 hour. After the reaction, the mixture was cooled, neutralized with acetic acid, deliquified, and washed twice with 5 kg of an aqueous methanol solution of methanol/water = 85/15.

Hydroxyethyl substitution of the generated C M HE C 1M
5=LOO, degree of carboxymethyl substitution DS=0.42.
The viscosity of the 1% aqueous solution was 118 CpS, the transparency of the 1% aqueous solution was 570 mm, and the transparency of the 1% solution when dissolved in a 4% saline solution was 530 m71.

Further, the utilization rates of ethylene oxide and monochloroacetic acid were 573% and 84%, respectively.

Example 5 Isopropanol 656 was added to a mixer with two-shaft stirring blades.
g and water 53.5. @, 54.3g of caustic soda and 70g of water
Pulp (degree of polymerization: approx. 700, water content: 6%) is prepared by adding an aqueous solution of caustic soda dissolved in P and crushing it with a hammer mill.
212.8 g was added and stirred at 15° C. for 1 hour.

In this case, the ratio of the total of isopropanol and water to cellulose is 4.0 times by weight (referred to as liquid ratio), and the ratio of isopropanol to the total of isopropanol and water is 82%.

The caustic soda is 1.1 times mole per anhydroglucose unit of cellulose.

After the alcelization, ethylene oxide 988I was added and the temperature was raised, and the reaction was carried out at 60°C for 1.5 hours and at 67°C for 1 hour.

A mixed solution of 58.3 g of monochloroacetic acid and 60 g of isopropanol was added, and after raising the temperature, the mixture was reacted at 70° C. for 1 hour. After the reaction, it was cooled, neutralized with acetic acid, deliquified, and methanol/water = 8
It was washed twice with 5 kg of a 5/15 aqueous methanol solution.

Hydroxyethyl substitution degree M of the generated C M HE C
S = 1.2, carboxymethyl substitution degree DS = 04
The viscosity of the 2.1% aqueous solution is 123 CpS, the transparency of the 1% aqueous solution is 490 m7, and the viscosity of the 1% aqueous solution is 1 when dissolved in the 4% saline solution.
% solution clarity was between 300%.

The effective utilization rates of polyester, ethylene oxide, and monochloroacetic acid were 585% and 84%, respectively.

Comparative Example 3 Pulp pulverized with a cutting mill (degree of polymerization approximately 700,
(contains 6% moisture) 106.4g, isopropanol 98g
4g and 169.6g of water into a 24 separable flask, add 27.2g of caustic soda,! After adding a caustic soda aqueous solution in which i+ was dissolved in 30 g of water, the mixture was stirred at 15° C. for 1 hour.

In this case, the ratio of the total of isopropanol and water to cellulose is 12.0 times the polymerization ratio, and the ratio of isopropanol to the total of isopropanol and water is 82%.

Caustic soda is 1.1 times mole per anhydrous glucose unit of cellulose.

After the alcelization, 47.4 g of ethylene oxide was added, the temperature was raised, and the reaction was carried out at 60°C for 1.5 hours and at 67°C for 1 hour.

Next, monochloric acid [29.2 g, isopropanol 3
0 g of the mixture was added. After raising the temperature, the reaction was carried out at 70°C for 1 hour. After the reaction, it was cooled, neutralized with acetic acid, deliquified, and mixed with 1.5 kg of a methanol aqueous solution of 85/15 methanol/water.
Washed twice.

Hydroxyethyl substitution degree M of the generated C M HE C
5=082, carboxymethyl position 41fDs=0,3
7.1% aqueous solution dust 150 CI) S, the transparency of 1% aqueous solution is 550gm, 1 when dissolved in 4% saline solution
The transparency of the solution was 90%.

Furthermore, the effective utilization rates of ethylene oxide and monochloroacetic acid were 47.0% and 74%, respectively.

Comparative Examples 4 to 6 Comparative Examples 4 to 6 were carried out in the same manner as Comparative Example 3, except that the ratio of isopropanol to the total of isopropanol and water during arselization was changed.

The results are shown in Table 2 together with the results of Comparative Example 3.

Claims (1)

[Claims] In a method for producing carboxyalkylhydroxyalkyl cellulose, which comprises reacting cellulose with an alkali in a mixed medium consisting of isopropanol and water to produce alkali cellulose, and subsequently reacting the alkali cellulose with an etherifying agent, the isopropanol of isopropanol is The ratio of water to the total is 80 to 8
The mixed medium, which is 7% by weight, is used 2 to 7 times by weight based on the cellulose, and 1.
A carboxyalkylhydroxyalkyl cellulose with good salt water resistance, characterized in that the alkali cellulose is prepared using 0 to 1.5 moles of alkali, and then the alkali cellulose is carboxyalkylated and hydroxyalkylated with an aelizing agent. manufacturing method.