RU1812179C - Method of finely crystalline cellulose producing - Google Patents

Abstract

Usage: in the porcelain, ceramic and homebuilding industries. SUMMARY OF THE INVENTION: Fibrous waste from the ginning and textile industries is treated with a 6% mixture. hydrochloric acid containing 1.0-1.5 wt.% ozone oxidizing agent. The treatment was carried out at 80 ° C, a liquid module of 1:50 for 1 hour. Microcrystalline cellulose was washed and dried. 1 tab.

Description

The invention relates to the processing of cellulose, in particular to a method for producing microcrystalline cellulose (MCC), which may find application in the porcelain, ceramic and homebuilding industries.

The purpose of the invention is to increase the brightness of microcrystalline cellulose while increasing the safety of the process.

The invention is illustrated by examples.

Example 5 g of cotton lint with an average fiber length of 7.50 mm, weediness of 4.48%, ash content of 1.50% and a-cellulose content of 95.40% is placed in a two-necked flask with a capacity of 1 l, equipped with a fridge - a barbator and a thermometer, pour 250 ml of a 6% hot 80 ° C aqueous solution of hydrochloric acid, after which an ozonized air mixture containing 0.1% ozone is passed through the solution for 60 minutes at 80 ° C. Then, the resulting MCC is filtered and washed repeatedly in a funnel Schott No. 1 until neutral washings, and then dried. The data obtained are given in table 1.

PRI me R 2. Similar to example 1 with the difference that an ozonized air mixture containing 0.5% ozone is passed through the solution.

When Merz. Similar to example 1, the difference is that an ozonized air mixture containing 1% ozone is passed through a solution.

PRI me R 4, Similar to example 1 with the difference that an ozonized air mixture containing 1.5% ozone is passed through the solution.

For measures 5. Similar to example 1, the difference is that an ozonized air mixture containing 2% ozone is passed through a solution.

PRI me R 6 (known method). 5 g of cotton lint with an average fiber length of 7.50 mm, a weediness of 4.48%, an ash content of 1.50% and an a-cellulose content of 95.40% are treated with 50 ml of a 6% hydrochloric acid solution in the presence of 2% chlorine peroxide at 80 ° C for 60 minutes

ate

with

with y

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The obtained MCC is filtered and washed repeatedly on a Schott funnel N ° 1 until neutral and then dried. The data obtained are shown in the table.

As can be seen from the data in the table, with an increase in the ozone content in the treated solution, the yield and degree of polymerization of the MCC slightly decreases with a simultaneous increase in the brightness of the resulting MCC. The optimum concentration of ozone, contributing to an increase in whiteness and yield. MCC is 1.0-1.5%. Therefore, in further examples, the ozone concentration in the treated solution is 1%.

From the data summarized in the table, it is seen that the proposed method for producing MCC by treating cellulose-containing raw materials in a hydrochloric acid solution containing a small amount of ozone helps to produce. MCC high quality pore compared with the known method. . ::; :.;

So, the data of example 3 in comparison with example 6 of the table indicate that when using the known method, the whiteness and yield of the MCC is 58-80%, respectively, whereas in the case of the proposed method the same indicator is 78-87%, respectively .e. the whiteness of the resulting product is increased by 20% and the yield by 7%.

The selected process parameters (temperature 80 ° C, treatment time 60 minutes, hydrochloric acid concentration 6%, ozone concentration in the treated solution 1.0-1.5%) are the most optimal, which is clearly illustrated by the table.

0

5

The selected temperature mode of 80 ° C is also optimal. Hydrolysis proceeds slowly below this temperature, and above that, ozone decomposes intensively and the intensity of oxidative processes decreases, which affects the quality of MCC.

The proposed method allows to reduce the time and cost of obtaining MCC, it is possible to reuse a solution of hydrochloric acid, because the latter is discolored by the action of ozone during the reaction, and also to make the process of obtaining the MCC environmentally friendly and to eliminate poisonous effluents.

Thus, the proposed method for producing MCC by hydrolysis of cellulose-containing raw materials with an aqueous solution of hydrochloric acid containing a small amount of ozone helps to improve the quality and ecology of MCC production, simplifies the technology and reduces the cost of obtaining MCC from cotton processing waste.

FORMULA AND SECTION

A method of producing microcrystalline cellulose, comprising treating the fibrous waste of the ginning and textile industries with a mixture of 6% hydrochloric acid and an oxidizing agent by heating, followed by washing and drying the target product, characterized in that, in order to increase the whiteness of microcrystalline cellulose while increasing the safety of the method , ozone is used as an oxidizing agent, with a concentration of 1.0-1.5 May in hydrochloric acid. % and processing is carried out at 80 ° C and a liquid module 1:50 for 1 h, 0

5

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5

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