SU174613A1 - - Google Patents

Description

A known method for producing cellulose esters by treating it with the chlorides of the corresponding organic acids in the presence of pyridine and an organic diluent, the process proceeds at elevated temperature for several hours. For example, cellulose stearate is obtained at a temperature of 100-130 ° C and a reaction time of about 24 hours.

There is also known a method of increasing the reactivity of cellulose in the preparation of its acetates by the esterification of cellulose with a mixture of acetic anhydride and acetic acid with a catalyst — sulfuric acid by treating the cellulose before esterification with anhydrous gaseous, liquid or dissolved in an organic solvent ammonia, or with the addition of an alkaline or alkaline-earth metal. temperature minus 33 ° C.

A method is proposed for producing cellulose esters by pre-activating cotton cellulose in the form of fibers, yarn or fabric by treating samples with anhydrous lower aliphatic amines at a temperature of minus 10-plus 30 ° C, followed by esterification of activated cellulose with the corresponding acid chlorides in the presence of pyridine and an organic diluent (benzene , heptane or hexane). As the lower aliphatic amines take metalplashn, etklamin, a mixture of methylamine with, propnyl - or butylamine, ethylenediamine, triethylamine. The displacement of the amine is carried out sequentially with anhydrous methanol and a non-polar or low-polar organic solvent, for example hexane, pyridine, or directly with chloroform or carbon tetrachloride. If it is not possible to carry out the esterification immediately after activating the cellulosic material, the latter is protected from moisture by storing it in an anhydrous environment.

The method provides fast production under mild temperature conditions of cellulose esters; any degree of substitution and high degree of polymerization with full preservation of the fibrous structure of fibers, webs or fabrics.

The cellulose esters of this invention are prepared as follows.

A sample of cellulosic material in the form of cotton fibers, yarn or fabric is immersed in anhydrous amine at a temperature of minus 10-plus 30 ° C for 10-60 minutes, depending on the properties of the starting cellulosic material and amine, as well as on the value of the introduced radical and the desired degree of substitution .

The excess amine is quickly sucked off and the swollen cellulose is repeatedly washed successively with anhydrous methanol and a non-polar nn malonic solvent, for example, hexane, neridinium, immediately with one chloroform or carbon tetrachloride. The pressed cellulosic material is treated with anhydrous nanocrystalline material necessary for the subsequent binding of hydrogen chloride released in the esterification process with an acid chloride of the corresponding acid. Wetting with nirnd is necessary prior to the introduction of the acid chloride, since pyridine additionally activates cellulose. Then, the activated cellulosic material is dipped into a solution of the acid chloride of the corresponding acid in benzene or heptane, or hexane, and is processed at a temperature of 20-50 ° C for 10-120 minutes. The amount of halogen, temperature and processing time is regulated depending on the properties of the raw materials, the cellulose ester produced and the required wall replacement. Thereafter, the esterified sample is thoroughly washed with an organic solvent of NLI, successively, with two solvents (for example, chloroforide, or carbon tetrachloride with ethanol) with water.

In some cases, for example, when receiving cellulose butnrates without interruptions, it is advisable to carry out additional stabilization of elephant ester ::; cellulose solution of carbonate Ka:; iiH in glacial acetic acid.

Example 1. Stearinil-aiye cotton fibers.

a) A sample of cotton fibers is submerged into anhydrous metnlamnn at minus and kept in the amine for 10-30 minutes, after which excess methylamine is quickly sucked off using a vacuum pump, and the swollen cellulose is repeatedly washed with successive anhydrous methanol n hexane or chloroform alone. The pressed fiber sample is moistened with anhydrous pyridine based on 1 g of 10 g of niridna fibers, and then it is treated by immersion in a solution of the chlorine stearic acid in benzene (20 ml of benzene per 1 g of cellulose) for 30 minutes at 20 ° C, with non-periodic non-mixing, moreover, per 1 mol of cellulose take 5 mol of acid chloride. The resulting cellulose stearate is thoroughly washed successively with chloroform with carbon tetrachloride, ethanol and water. Under these conditions, cellulose stearate is obtained in the form of fibers with a replacement wall in 150. Elemental analysis in o / o: C 70.9-70.28; H 10.37-10.27. b) When esterification of cellulose is activated, similar to that indicated in paragraph a, but for about 50 minutes, cellulose stearate is obtained. c. Elementary analysis in o / o: C 67.5; H 11.1.

c) In the esterification of cellulose, activated as described in a, but for 60 minutes, cellulose stearate fibers are obtained with a degree of substitution.

Elementary analysis in C 71.99-72.04; H 11.12-11.40.

d) Upon receipt of cellulose stearate under the conditions specified in paragraph and ,; but with the amount of stearic acid chloride twice as small (2.5 mol per 1 mol of cellulose), stearate c is formed. Elementary analysis in o / o: C 69.7; P 10.9.

e) Activated cellulose ethylenediamine fibers. The advantage of ethylenediamine is the higher temperature of its accumulation, which makes it possible to carry out the process of activating cellulose at room temperature.

A sample of cotton cellulose fibers is treated with ethnlenediamine for 30 minutes at 20 ° C. The excess ethnlandnamine is filtered off and the amine is squeezed out successively with ethanol and hexane. Subsequent injections are carried out in the same way as in paragraph a.

At the same ratio of components, the esterification reaction was carried out for 60 hours at 20 ° C. Cellulose stearate is obtained in the form of degree-substitution fibers. Elementary analysis in%: C 70,19-

70.23; H 10.89-10.72.

e) Activated cellulose with anhydrous trmethlamine ..

A sample of cotton fibers is treated with anhydrous trimethylamine nrn minus 5C

for 30 minutes The remaining operations are carried out in the same way as described in paragraph an with the same ratios of the components. Eternation is carried out for 60 min. Get cellulose stearate in the form of fibers, with

replacement wall. Elementary analys in o / o: C 72.04--71.99 ;: P 11.22-11.40.

Example 2. Stearinated cotton yarn.

The yarn sample is treated with an anhydrous metnlamnnom nrn mnus 10 ° C for 30 minutes. Metnlamnn is squeezed out of the tissue by repeated washing with chloroform. Then, it is pressed from excess chloroform and moistened with pyridine in the calculation of 1 g of the yield of 10 g of pnrndia, after which it is treated with a solution of chlorine-steenic acid in benzene (25 ml of benzene per 1 g of the acid), taken in the calculation of 5, 5 mol of acid chloride PA 1 mol of cellulose, for 60 minutes at 20 ° C. Subsequently, the sample, which is similarly embedded in the example, a, is prepared with a degree of substitution. Elementary analysis in o / o:

C 71.33 - 71.22; P 10.92-10.95.

Example 3. Stearinilation hlonchatka tissue.

new substitution Y 160. Elementary analysis in o / o: C 70.61-70,54; H 11.15-10.94.

Example 4. Butylation of cotton fibers.

a) A sample of cotton fibers is activated with anhydrous methylamine at -10 ° C for 30 minutes. After activation, the methylamine is squeezed, and its residues are squeezed out with methanol and hexane. The excess hexane is then wrung out, the fibers are moistened with niridine (10 g of pyridine per 1 g of cellulose fibers) and treated by immersion in a solution of butyric acid in benzene (20 ml of benzene per 1 g of fibers), taken at the rate of 9 mol of butyl acid per 1 mole of cellulose, for 120 minutes at 20 ° C. At the end of the reaction: the butyryliphenol is further stabilized with a fiber by treating with an lOo / 0 solution of potassium carbonate in glacial acetic acid, and then washing with methanol and warm water.

Cellulose butyrate is obtained in the form of fibers with a content of b6,2 + 0,2 o / o bussing oil acid (by the method of saponification with 0.5 o / optic solution of caustic potassium in an alcoholic medium), i.e. with a degree of substitution.

b) The process of esterification of cellulose fibers with butyric acid chloride is carried out at 40 ° C for 30 minutes, while otherwise observing the conditions indicated in Example 4, a. Cellulose butyrate is obtained in the form of fibers with a content of 70 + 0.3 o / o bound butyric acid, i.e., c.

c) A sample of fibers is activated with ethylene diamine for 60 minutes at 20 ° C. The process of etherification of cellulose fibers with acid chloride of butyric acid is carried out at 40 ° C for 60 minutes while otherwise observing the conditions indicated in Example 4, a.

Bougrinlated fibers are obtained with a content of 70.2 ± 0.3 / o bound butyric acid, i.e., with a degree of substitution of 300.

Example 5. Cotton yarn bottling

A portion of the yarn is activated with anhydrous methylamine at –10 ° C for 30 min. The methylamine is squeezed out, its remains are replaced by methanol and hexane. After pressing the excess hexane activated, the yarn is wetted with pyridine (10 g of pyridine per 1 g of yarn) and immersed in a solution of butyric acid in benzene or in heptane at the rate of 20 ml of solvent per 1 g of yarn and 9 mol of 1 mol of acid chloride per 1 mole cellulose in the form of yarn. A bottled yarn is obtained with full preservation of the fibrous structure with a content of 64 + 0.50 / 0 bound oil acid, i.e. the degree of substitution.

Example 6. Cotton fabric butyrhylated.

reinforced fabric with a degree of substitution in cellulose.

Example 7. Obtaining valeriates cellulose.

A sample of cotton fiber is activated with ethyleneamine at 20 ° C for 60 minutes. The excess amine is squeezed out, its remnants are displaced by washing with methanol and hexane. After extraction of excess hexane, the activated cellulose is moistened with pyridine (10 g of pyridine per 1 g of cellulose) and immersed in a solution of valeric acid chloride in heptane containing 20 ml of hentane per 1 g of cellulose and 9 mol of valerianic acid. The esterification process is carried out for 120 minutes at 20 ° C, otherwise the process is carried out as in Example 1, a. Fibrous cellulose valerate is obtained with a content of 70 + 0.1 v / o of bound valeriic acid, i.e., with a replacement wall.

Example 8. Obtaining cellulose benzoates.

a) 1 g of cotton cellulose is activated with anhydrous methylamine at minus 10 ° C for 30 minutes. Then, the excess methylamine is squeezed, its residues are displaced by pyridine. The activated cotton fiber is squeezed from an excess of pyridine to the content of the latter in an amount of 10 g and immersed in a solution of 6 g of benzoyl chloride in 20 ml of benzene. The esterification process is carried out at 20 ° C for 60 minutes, the subsequent repeated washing of the cellulose benzoate fibrous is carried out with ethanol and hot water. The benzoyl yarn fiber thus obtained contains 63 + 0.2 v / v of bound benzoic acid, i.e. the replacement wall.

b) The process of activating cellulose fibers and esterification is carried out as described in Example 8, but the esterifying solution contains 2.4 g of benzoyl chloride in 20 ml of benzene, the benzoyl-containing fiber contains 500/0 bound benzoic acid,

i.e.

Example 9. Benzoylation chlonkovogo yarn.

1 g of yarn is activated by methylamine at minus 10 ° C for 30 minutes, after which the excess

methylamine is eliminated and its residues are replaced with pyridine. Then, the activated yarn is squeezed from an excess of pyridine to the content of the latter in an amount of 11 g and immersed in one smelly benzoyl chloride, taken in

large excess, for 5 minutes at a temperature. The rest of the process is carried out as described in example 1, and. The resulting benzoyl-yarn, according to the elementary analysis, contains in o / c: C 63.53-67.77;

H 5.17; degree of substitution.

corresponding acids in the presence of pyridine and an organic diluent, characterized in that, in order to reduce the esterification time, decrease the process temperature and obtain products with full preservation of the fibrous structure of fibers, yarn and fabric, activating cellulose in the form of cotton fibers, yarn or fabric by treating it with anhydrous lower aliphatic amines at a temperature of min-, nus 10 - plus 30 ° С with squeezing and displacing amines with organic solvents and subsequent esterification of the resulting activation bath cellulose in the presence of pyridip and benzene or heptane, or hexane.

2. The method of claim 1, characterized in that the aliphatic amines are taken as nibrich

methylamine, ethylamine, a mixture of methylamine with ethyl, propyl or butylamine, ethylenediamine, triethylamine.

3. Method according to paragraphs. 1 and 2, characterized in that the displacement of the amine is carried out sequentially with anhydrous methanol and a non-polar or low polar organic solvent, for example hexane, pyridine, or immediately with chloroform alone or carbon tetrachloride.

4. Method according to paragraphs. I-3, characterized in that if it is not possible to carry out the esterification immediately after activating the cellulosic material, the latter is protected from moisture by storage in an anhydrous medium.