CS205404B1 - Manufacturing process of water-soluble hydroxyalkylcelullose ethers - Google Patents

Description

Process for producing water-soluble hydroxyalkyloelulose ethers

SUMMARY OF THE INVENTION The present invention provides a novel process for the production of water-soluble alkyloellulose ethers from alkali cellulose, wherein the reaction conditions are selected such that they substantially affect the yield and, in particular, product quality and process safety.

The present invention is characterized in that the treated cellulose e is heterogeneously etherified with an alkylene oxide or a mixture of alkylene oxides at a temperature of 20 to 130 ° C and a pressure of 0.002 to 4 MPa, the alkylene oxide or a mixture of alkylene oxides being metered to 0.2 to 75% by weight. % of bound alkylene oxide and / or mixtures of alkylene oxides.

In the second step, the etherified reaction mixture obtained is neutralized in a polar solvent medium or a mixture of polar solvents. The obtained faydroxyalkyloelulose ethers are isolated.

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SUMMARY OF THE INVENTION The present invention provides a novel process for the production of water-soluble hydroxyalkyloellulose ether from alkali cellulose, wherein the reaction conditions are selected such that they substantially affect yield and product quality and safety.

Many Spdeob's production of water-soluble hydroxyalkyloeluloses are known. However, the prior art processes (U.S. Pat. Nos. 1,941,276, 3,351,583 and U.S. Patent Certification Nos. 168,179, Ί68,169, 159,002, 129,134, and 161,434) are highly dependent on the form and structure of the cellulose used and are insufficiently focused. for the treatment of alkali cellulose, which in the further process results in the resulting etherified mixtures obtained resulting in high content, ash and by-products. Unsuitable neutralization at the end of the process has a considerable effect on the volume of the solvents used in the wash. All these and other shortcomings of the prior art processes reduce the yield and poor product quality, resulting in reduced production of the prepared hydroxyalkyloellulose ethers and increased production costs.

According to the present invention, a process for the production of water-soluble hydroxyalkyloellulose ethers by alkali cellulose etherification at room temperature or elevated temperature, by the action of alkylene oxide or a mixture of alkylene oxides, is effected in a two-stage process. 100 to 250 kg / m < 2 &gt; is heterogeneously etherified with an alkylene oxide or a mixture of alkylene oxides having 2 to 4 carbon atoms per molecule in an amount of 5 to 500 wt. calculated on &lt; X-oellulose at a temperature of 20 to 130 ° C, preferably 30 to 80 ° C and a pressure of 0.002 to 4 MPa, preferably 0.1 to 2 MPa, wherein the alkylene oxide or alkylene oxide mixture is dosed intermittently, semi-continuously and / or or continuously, to about 0.2 to 75 wt. % of bound alkylene oxide and / or a mixture of alkylene oxides, in a second step, the obtained etherified reaction mixture is neutralized in a polar solvent or mixture of polar solvents, preferably by a gaseous or liquid neutralizing agent or agents, any excess of which is further removed and preferably blown out and / or by suction under reduced pressure and recovering the hydroxyalkyloellulose ethers obtained.

The excellent results of the formation of hydroxyalkyloellulose ethers by high yield and low ash content are achieved by a suitable treated alkali cellulose, mainly free of excess water and sodium hydroxide, which content depends on the type of alkylene oxide and / or the alkylene oxide used. For reasons of safety and affecting reaction brilliance, it flows in a wide range of pressures and temperatures. However, it should be noted that lower pressures (below 0.1 MPa) in some cases is quite disadvantageous, especially when ethylene oxide and propylene oxide are used as etherification agents. Therefore, the reacoia are usually triggered under normal and non-normal conditions. only a slight increase in pressure, while further maintaining the pressure and temperature ea maintains the temperature at which the active agent is low and the possibility of uncontrollable prooess is unlikely for individual alkylene oxides and / or mixtures. Alkylene oxides such as ethylene oxide, propylene oxide, isomeric

Butylene oxides, butadioronone oxide, mixtures of epoxides obtained, for example,. in the separation of pyrolysis O-fractions, but also in the pyrrolidines and glyoidols. In the second step, the neutralization is carried out in a temperature range of 0 to 30 ° C while flowing in a medium of polymers such as water, alcohols, ketones, ethers or mixtures, and the like. Good results in neutralization and epithelial solvent regeneration were obtained using methanol, isopropyl alcohol as well as a mixture of methanol and acetone. The use of water requires special techniques of stripping, the crude reaction product. The desalted solution of hydroxyxyalkyl is then treated with a conventional drying apparatus. A wide variety of acid-reactive compounds such as sodium hydrophosphate, sodium dihydrophosphate, sodium hydrogen sulfite, sodium hydrosulfate, sodium pyrosulfite, thionyl chloride, sulfuric acid, sulfuric acid, and ultimately, nitric acid, especially phosphoric acid, trisodium phosphate, oic acid, oitronic acid and propionic acid, as well as mixtures of nitric acid with acetic acid, acetic anhydride with nitric acid and mixtures of acetic anhydride, acetic acid and hydrochloric acid. The perfect mass transfer in the neutralization was achieved by spraying the above-mentioned acid-reactive compounds into the neutralization mass. Very good fumes are mainly obtained using acid gases such as chlorine, hydrogen chloride, carbon dioxide, sulfur trioxide, sulfur dioxide or mixtures of halogens and sulfur dioxide or mixed sulfur or nitrogen oxides. When using gases, the neutralization is generally carried out at elevated pressure and the desorption of excess gas by suction under reduced pressure by the action of an inert gas. The final washing and the usual polar solvents are used, preferably those which are used in the second stage for neutralization. Most of the solvents can be used in the first washing phase and in addition to the weakly alkaline reactants of various detergents, ammonium hydroxide, ammonium carbonate and the like in an amount of 0.1 to 15 wt. % of solvent used.

An advantage of the method according to the invention is the possibility to use all the available alkali celluloses from different types of pulp. Prooss provides low ash and by-product products, while reducing the reaction time, increasing yield and safety of the process by means of a suitable pressure and temperature regime. The final purification stage ensures a high degree of purity, low yields for higher yields, as well as easy, inexpensive solvent recovery. Last but not least, by the appropriate selection of neutralizing agents, it is also possible to produce, at the same time, teohnio and economically valuable products, such as e.g. using trihydrogenphosphoric acid and its hydro salts, in addition to its own main product ea, it can produce phosphates suitable as feed salts for nutritional purposes and the like.

Example 1

We weighed 550 g of alkali-cellulose containing 5% by weight into an autoclave having a volume of 5 dm @ 3 equipped with a paddle system rotating inside the autoclave just next to the stoc. NaOH;

wt. # HgO and 50 wt. % cK-cellulose. After closing the autoclave,

205 404 lute pressure 2 kPa. Thereafter, medical nitrogen was added up to a pressure of 20 bar. After degassing of nitrogen, the autoclave was carefully evacuated and nitrogen was added again up to 20 bar. We repeated this 3 times the autoclaving to remove the adsorbed oxygen as best as possible. Then the contents of the autoclave were heated to 30 ° C with continuous stirring and ethylene oxide was added gradually. We also gradually increased the autoclave temperature by 1 ° C / min. up to 60 ° C. During this time we dosed with a total of 825 β ethylene oxide (27.5 g / min). We then left for 30 min. the reaction vessel dropped to 0.1 MPa after cooling to 25 ° C and sulfur dioxide gas was added to the reaction mixture while the reaction vessel pressure dropped. After stabilizing the pressure in the reaction vessel and thoroughly mixing, the autoclave was degassed, the absorbed and free sulfur dioxide was displaced by blowing with air. The neutralized crude product was dispersed in 2 dm 3 of methanol-oetone in wt. 1: 1 ratio. After good mixing, the product was air-dried and milled. The dried reaction product had the following composition: 51.8 wt. hydroxyethoxy; 1.1 wt. # ash;

PPS = 296 units

Example 2

Into the alkylation autoclave, as described in Example 1, was charged 550 g of alkali cellulose of the following composition: 0.72 wt. % NaOH; 14 wt. 5 HgO and 85 wt. The autoclave was heated to 60 [deg.] C. with an isobutene content of 47 g / min and the pressure in the autoclave was kept constant during the addition of butylene oxide. After 1440 g of isobutylene oxide was metered in over 30 minutes, the reaction mixture was allowed to react for 1 hour, after the autoclave was degassed and cooled to room temperature, sulfur dioxide was added and the excess SO4 was removed by blowing air and evacuating. The product after drying contained 63.83% by weight of hydroxyisobutoxy groups, 0.46% by weight of ash and PPS, and 328 .mu.l of isopropyl alcohol.

Example 3

We proceeded similarly to Example 2 except that we used alkalio-cellulose containing 14 wt. NaOH, 50 wt. % ^H 2? 34 wt. $ ρζ-oaluloses. The isobutylene oxide was dosed in a total amount of 561 g with a fineness of 18.7 g / min. The product contained 45.9 wt. % hydroxyisobutoxy groups; 66 wt. $ ash; PPS = 272

Note: mass. % of hydroxyisobutoxy groups as well as PPS were determined after ashing of the final product.

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Example 4

The procedure was similar to that of Example 2, except that butadlene monoxide was used as the alkyl oxide. The product after drying contained 57.6 wt. % hydroxybutyloxy; 0.52 masses of ash; PPS and 218 j.

Example 5

The procedure was similar to that in Example 3, except that butadiene monoxide was used as the alkylating Si reagent. The product after drying contained: 46.9 wt. hydroxy hydroxybutyloxy groups; 71 wt. # ash; PPS and 228 j.

Example 6

We proceeded as in Example 2, but with the difference that propylene oxide was used as the alkylating agent. The dried final product contained 50.2 wt. hydroxy hydroxypropoxy groups; 0.51 wt. % ash; PPS and 312 j.

Example 7

We proceeded similarly to Example 3, except that propylene oxide was used as the alkylating agent. The dried final product contained 40.6 wt. % hydroxypropoxy groups; 73 wt. ash) PPS and 286 j.

Example 8

We proceeded similarly to Example 1, except that instead of SO2, we used a mixture of acetic acid anhydride and hydrohalic acid acetic anhydride under vacuum in a gas phase at a temperature of 30 ° C as a neutralizing agent. The dried final product contained 51.6 wt. 1-ethoxy-dcupine; 2.8 wt. % ash; PPS and 314 j.

Example 9

We proceeded similarly to Example 1, except that a 10% solution of oic acid in acetone was used as neutralizing agent. We only did the extracacia with the Clean Aetone. The dried reaction product contained 52.4 wt. % hydroxyethoxy groups;

wt. % ash; PPS and 311 j.

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Example 10

We proceeded similarly to Example 1. Crude after neutralization with ^SO 2, the reaction product was divided into 6 equal portions and extracted with different extractants and procedures. The purification results are shown in the table below.

Extracting agent Quantity and method extractions Ash content (^ mass) 1. Water (10O? - aqueous solution) 4 hours cleaning electrophoresis 0.02 2. Methanol-acetone (i: i) 3 1x 2,000 © ar 1.12 3. Methanol 1x 2,000 om ³ 1.01 4. Isopropanol - Oetethene (1:) 3 1x 2 000 onr 4.7 5 · Isopropyl alcohol 1x 2,000 cm ³ 4.5 6. Acetone 1x 2,000 cm ³ 7.2

Example 11

We proceeded similarly to Example Z, except that we used a mixture of epoxides prepared from pyrolysis fraction by epoxide as the alkylating agent. The mixture had a composition of 74 wt. % isobutylene oxide, 12 wt. # butadiene monoxide, 10 wt. % propylene oxide and 4 wt. isomeric butylene oxides. After drying, the mixture contained 60.8 wt. % hydroxyalkyloxy groups (calculated as isobutylene oxide); 0.52 wt. % ash; PPS = 313 units

Example 12

We proceeded similarly to Example 3, except that the mixture of epoxides prepared from the pyrolysis fraction composition as in Example 11 was used as the alkylating agent. After drying, the mixture contained 45.9 wt. % hydroxyalkyloxy groups (calculated as isobutylene oxide); 29.6 wt. % ash; PPS = 285 U

Example 13

We proceeded similarly to Example 1, except that a continuous flow system was used instead of a 5-key auto key so that the alkali cellulose reacted in the fluidized bed in a stream of circulating ethylene oxide. The product after neutralization with SO2 gas also contained 56.4% by weight in the fluidized bed after washing and drying. % hydroxyethoxy groups; 1.1 wt. $ ash; PPS and 256 j.

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Claims (3)

OBJECT OF THE INVENTION 1. A process for the production of water-soluble hydroxyalkyloellulose ethers by etherification of alkali cellulose at room temperature or at elevated temperature, by the action of alkylene oxide or a mixture of alkylene oxides, characterized in that in a two-step process e. up to 250 kg / m < 2 &gt; is heterogeneously etherified with an alkylene oxide or a mixture of alkylene oxides having 2 to 4 carbon atoms per molecule in an amount of 5 to 500% by weight, calculated on α-olulose, at a temperature of 20 to 150 ° C, preferably 30 to 80 ° C and a pressure of 0.002 to 4 MPa, preferably 0.1 to 2 MPa, wherein the alkylene oxide or the alkylene oxide mixture is metered in a continuous, semi-continuous and / or continuous manner, until 0.2 to 75% by weight of the bound alkylene oxide and / or mixture is reached. alkylene oxides, in the second step the etherified reaction mixture obtained in an environment of a polar The neutralizing solvent is preferably neutralized, preferably by a gaseous or liquid neutralizing agent or by a blowing agent, which eventual debris is further removed, preferably by gas purging and / or suction under reduced pressure, and the resulting hydroxyalkyloolulose ethers are isolated. 2. A process according to claim 1, characterized in that, after etherification, the hydroxyalkylo-cellulose mixture is neutralized with acid gas, preferably sulfur dioxide, sulfur dioxide, chlorine, hydrogen chloride and / or inorganic and / or organic acids and anhydrides, preferably acid. ootic acid, aostanhydride, formic acid and phosphoric acid and / or alobo salts of acid-substituted hydrogen, preferably sodium hydrogen phosphate, sodium dihydrophosphite, sodium hydrosulfite, sodium hydrosulfate and sodium hydrosulfite and / or sodium bisulfite, , thionyl chloride and sulfuryl chloride. 3. The process according to claim 1, wherein in the second step in which the neutralization is carried out, the polar solvent medium comprises at least one of a group of solvents: water, acetone, methyl ethyl ketone, lower aliphatic alcohols, in particular isopropyl alcohol, diethyl ether and diethyl ether. methyl tertiary butyl ether.