SU1065424A1 - Process for recovering synthetic rubbers from latexes - Google Patents

Abstract

METHOD OF ILDELEYSH OF SYNTHETIC RACKS FROM LATEXES by the action of organic coagulant p. the subsequent separation of the resulting crumb rubber from the serum, characterized in that, in order to simplify the process technology and reduce the consumption of coagulant, 0.01-3% by weight of rubber of collagen protein hydrolyzate with a content of 0.7-20 may be used as the latter. % carboxyl groups.

Description

The invention relates to the production of synthetic latexes, in particular to their removal from latexes, and can be used in the petrochemical industry. A known method for isolating synthetic rubbers from latexes with sodium chloride and sulfuric acid TiT. Depending on the type of polymer, the consumption of sodium chloride and sulfuric acid is 200-2000 kg and 10-20 kg per ton of rubber is appropriate. The volume of production of emulsion rubbers amounts to hundreds of thousands of tons, an enormous amount of sodium chloride is discharged into the water bodies of the country, which causes irreparable damage to the environment. The closest to the invention according to the technical essence is the method of isolating synthetic materials from latexes by the action of organic coagulum, followed by separation of the crumb rubber from serum f2. A solution of a polysaccharide and of a protein substance of plant origin and a polyamine water soluble component is used as an organic coagent. A solution of polysaccharide and protein matter of plant origin is prepared by dissolving corn starch, soy flour, wheat flour, peanut flour, sunflower in alkaline water. Polyethylenepolyamine is used as a prliaglin component. However, the use of these plant products requires additional alkali metal hydroxide when reagent is used, the use of alkali requires neutralizing the acid in the process of acid coagulation of the latex, dissolving the plant products in alkali does not result in a true solution, but labor separable suspensions that need to be filtered. In production, this stage causes great difficulties. The duration of the preparation of the alkaline solution, including the filtration stage.,. it is 4-6 hours. The effectiveness of soy flour as it grows 5 times under the conditions of the powder decreases. Soybean flour, corn, wheat, peanuts, and sunflower are food and feed products. The aim of the invention is to simplify the process technology and reduce the consumption of coagulant. This goal is achieved in that, according to the method of isolation, synthetic rubber from latexes by the action of organic coagulum, followed by separation of the resulting rubber rubber from serum, the coagulant is used as .0.01-3% by weight of rubber protein collagen hydrolyzate rubber containing 0.7-20 wt.% Carboxyl groups. The proposed method for isolation of synthetic rubbers is applicable to latexes of such rubbers as butadiene styrene (ot-methylstyrene), butadiene nitrile, polyisoprene, polybutadiene, carboxyl-containing, as well as any combination obtained using d1-1en and vinylaromatic monomers. P and m .p 1. Protein hydrolysis is obtained from scraps of the sausage casing from the Luga plant Belko-, zine. Cuts of the protein sausage casing, in turn, obtained from the waste of collagen - spilted preparation, were additionally ground 120 g are added to the flask with a stirrer, 200 mp of 0.2% aqueous solution of sulfuric acid is added. The temperature is raised to 100-120 ° C in 30 minutes and this moment is taken as a zero count. Samples of the protein solution are sampled, analyzed for the content of carboxyl groups by potentiometric titration according to TU 49-016-19-03-80 calculated on the dry residue of the solution, and the amount of protein going to release 100 g of rubber is determined in parallel. To 180 ml of SCS-ZOARKP serial latex of butaiyenstyrene rubber with a dry residue of 22.4%, add a 5% solution of the selected sample of hydrolyzate in the minimum amount that causes full latex coagulation at pH 2 at. Table 1 shows the effect of protein hydrolyzate on latex coagulation. Table 1

Continued table. one

36.7 36.7 36.7 36.7 36.7 36.7 36.7 36.7 As can be seen from the table. 1 Collagen protein hydrolyzate with a certain content of carboxyl groups is very effective as a coagulating agent. Example 2. Protein hydrolysate is obtained from the ash core (OST 17-442-74 - subcutaneous connective tissue. The mezdra is washed with softened water, crushed and treated with 2% with an aqueous solution of ammonium sulfate until the pH of the solution is 7, after which it is again mixed with water. The resulting raw material is loaded into a round bottom flask equipped with an agitator, a thermometer and a reverse refrigeration with NIKOM. nd acid naked Revai reactor contents with stirring to 100-.

Note 3. A 2% aqueous solution of a hydrochloric solution is poured into a glass.

100 MP serial latex sample butadiene protein hydrolyzate Beltsirolnogo rubber and heated to Kozin M, obtained by hydrolysis

60-65 ° C. While stirring, 5collagen is added with hydrochloric acid containing 0.11 11.11.11.11.11.11.11.11.13.13 ° C and kept at this temperature for 3-7 hours. Reagent consumption: Raw materials 200-250 Water, ml 200 Sulfuric acid, MLO, I, Along the course of the hydrolyzate, samples of the hydrolyzate are collected, filtered through gauze or cotton, analyzed for the content of carboxyl groups based on the dry residue of the solution and in parallel determine the amount of protein released for excretion. 100 g of rubber .. Table 2 shows the change in the concentration of carboxyl groups in the protein hydrolyzate of the core and its consumption yes to coagulation. Table2 of the carboxyl groups is 4.7%, obtained by hydrolysis of pieces of the sausage casing. Mix for 7 minutes, add a 1% solution of sulfuric acid until the pH of the serum 3. The mixture is kept for 10-15 minutes and a 25% solution of sodium chloride is added to complete the coagulation and obtain a transparent serum. Yo table. 3 shows the consumption of protein hydrolyzate and sodium chloride for the coagulation of the SCS-ZOARKP rubber latex. . Table 3 Example 4. In a glass pouring 100 ml of latex butadiene nitrile rubber SKN-26 GM with a dry residue of 23.6%, heated to 60 ° C. With stirring, a 5% solution of the protein hydrolyzate Belkozin-M obtained by the hydrolysis of collagen with hydrochloric acid is added, with a content of 5.3 box per 2% of the protein hydrolyzate per rubber, lured for 7 minutes. 52 m of a 25% sodium chloride solution are added at the rate of 500 kg per ton of rubber. Coaguli qi is full, crayon chalk. The consumption of Belkozin K and sodium chloride for the coagulation of butadiene nitrile latex is given in Table 4. Table From Table. 4, it can be seen that the introduction of protein hydrolyzate in the amount of 20 kg per 1 ton of rubber reduces the consumption of sodium chloride by three times in the production of nitrile rubbers. Approx. 5. The apparatus is loaded with 6 liters of serial latex from a mixture of SKS-ZAARKM-15 latex and styrene-butadiene rubber latex and buZgadien-o methyl styrene resin containing 80% aromatic monomer vinyl and a 2% protein hydrolyzate Belkozin M containing carboxyl groups 5.2% at the rate of 0.7 mph. protein hydrolyzate to polymer. Latex with protein hydrolyzate is mixed for 10 minutes, then O, 5% solution of sulfur: acid to pH 5 and then 0.1% solution of sulfuric acid to pH 2 is gradually added. A large, well-washed EC rubber crumb is obtained. 45. PRI and, me r 6. In a glass, pour 100 ml of serial l-atex butadiene-methyl rubber SKMS-. -ZOARKM-27 and heat up. With stirring, a 2% aqueous solution of protein hydrolyzate Belkozin M with a carboxyl group content of 4.7% based on 0.4% protein hydrolyzate per rubber is added, an emulsion of 5 g of oil PN-6 is added, mixed for 5 minutes. Then, a 1% solution of sulfuric acid is added up to pH 1. Complete coagulation is observed, the resulting crumb is washed well with water and dried. Example 7. In industrial conditions, a SKS-ZOARKPN styrene-butadiene rubber latex is supplied with a working solution of collagen protein hydrolyzate from scraps of the protein sausage casing Belkozin M with a carboxyl group content of 5.3%. The supply of sodium chloride solution to the coagulation is pre-disconnected and the latter is not fed to the latex. At start-up, the returnable serum containing sodium chloride is completely drained, the coagulation cascade apparatus and the capacity of the return serum are filled with softened water acidified to a pH of 3.5. Coagulation of latex with protein hydrolyzate proceeds completely. Serum transparent. The production of SKS-ZOARKPN rubber with the application of collagen protein hydrolysis was carried out using the following process parameters: Coagulation temperature, ° С58-65 pH in the coagulation apparatus 3.0-3.6 pH of squeezing water after the expeller 5.0-6, 0 Consumption Belkozina M 0.5-2 kg per 1 ton of rubber

Selection, pressing and drying of rubber proceeded normally.

Conditional tensile strength

MPa, not less

Elongation at break,

%, not less

Relative residual elongation

As can be seen from the table. 5 rubber vulcanizates 50, isolated by protein hydrolyzate, are characterized by a high complex of properties.

Example 8. The experiment was carried out according to Example 7 55 using the SCS-ZOARKM-15 production of styrene-butadiene rubber latex containing 16% of mineral oil PN-6. Yadelekie rubber is carried out using proteinaceous protein hydrolyzate K containing a table. 5 shows the properties of the obtained rubber.

Table 5

28.0 632

by carboxyl groups of 5.3% with complete elimination of sodium chloride. Coaguli proceeds completely, the resulting serum is transparent. 300 tons of experienced rubber were produced with the consumption of protein hydrolyzate in the amount of 1.5-2.0 kg per 1 ton of rubber. Serial rubber is released by sodium chloride at the rate of 230 kg per ton of rubber. The properties of the experienced rubber in comparison with the serial are given in table 6.

metals,%, not

antioxidant

la%

related second

As can be seen from the table. b rubber isolated by protein hydrolysis has a high complex of properties.

Example 9 To 100 ml of polyisoprene latex with a dry residue of 18.2%, heated to, add 30 ml of a 2% solution of protein hydrolyzate. Belkosin M With carboxyl groups content of 5.1% (based on 3% for rubber |, then acidified with 1% sulfuric acid to pH 6. The rubber is isolated in the form of a curd white mass, and the transparent serum is transparent.

Table 6

23.8

22-25

22,6

Example 10 To a 100 ml polybutadiene latex with a dry residue of 15, T%, heated to 70 ° C, was added 22.2 g of a 2,1-hb solution of Belkozin M protein hydrolyzate with a carboxyl group content of 5.1% (based on 3 % rubber /. The latex is then acidified with 1% sulfuric acid to pH 4. The rubber is emitted as a white coma, the serum is transparent,

Example 11. K7l carboxylate styrene-butadiene rubber latex (bound styrene content 29.1%, dry residue 21.5%, carboxyl group content 1.9% V heated to 45 ° C, added 2% aqueous solution of protein hydrolyzate Belkozin M with a carboxyl group content of 5.1% at a rate of 1% for rubber. Latex is acidified with a 1% solution of sulfuric acid to a pH of 6. Rubber separates in the form of small, good ROCH1O forming crumb, the serum of a powder is transparent. meper 12. To 200 ml of latex butadiene-c (.- methyl styrene rubber SKMS-50, placed in a glass with energy With an agitator with a dry residue of 14.3%, heated to 50 ° C, 3 ml of a 2% solution of protein hydrolyzate Belkozin M are added (at the rate of 0.4% for rubber Latex is acidified with a 1% solution of sulfuric acid to pH 3. Rubber is isolated in the form of horned crumbs, serum is transparent. Example 13. Collagen protein hydrolyzate is obtained by hydrolysis of a mixture of chrome chips, yromide, dilute sulfuric acid and checked as a coagulative agent of example 1 on the rubber latex SCS- ZOARKPN. In tab. Figure 7 shows the results on the characteristics of the resulting hydrolyzate and its effect on coagulation. Table 7 As can be seen from the table. 7, the multi-tonnage waste of collagen produces a protein hydrolyzate that is effective as a coagulating agent. Example 14. IC 100 ml serial lot of the SKD-ZOARPD butadiene styrene rubber band with a dry residue of 21.3% with a quick stirring added 2% protein Belkosin M hydrolyzate solution with a carboxyl group content of 5.3% from 0.15% per rubber , acidified with sulfuric acid to pH 2. Rubber is released in the form of coarse crumbs, well separated from the serum, rubber drying proceeds normally. Under production conditions, expenditure ratios and manufacturability of the recovery method were confirmed. Example 15. To 100 MP of the serial latex of the styrene-butadiene rubber SKS-ZOARKP with vigorous transfer. while mixing at 60c, a 1.9% solution of protein hydrolyzate is added with a carboxyl group content of 2.2%, obtained by hydrolyzing the flesh with water, at a cost of 0.1% per rubber. After stirring, a 2% solution of sulfuric acid is added to the solution to pH 1. The latex is completely coagulated, the horse crumb is washed and filtered. . Example 16. With vigorous stirring, a 2% solution of protein hydrolyzate with CO content of 7% carboxyl groups, obtained by hydrolysis of calcium hydroxide cut out according to RSFSR 12-04-0281, is calculated with 100 ml of the commercial latex SKS-ZOARKP, calculated as 0.25 and 3%. The mixture was then acidified with 1% sulfuric acid to pH 6.5. The rubber is completely excreted in the form of a well-formed crumb, which is easily separated from the serum and dried. In the second case, with the delivery of 3% protein hydrolyzate to rubber, the crumb is larger. Example 17. The test is carried out according to example 16 with a protein hydrolyzate containing carboxyl groups of 7.1% and a mole obtained from scraps. The complete coagulation of the latex rubber ca. SKS-ZOARKP was observed at a flow rate of 0.45% protein hydrolyzate. The baby is well separated from the proposed method has the following advantages. Collagen protein hydrolyzate is available as it is obtained from leather wastes. For the production of gollagen protein hydrolyzate, waste is used: spilk trimming, scraps of fish, meat cuts of non-conditioned protein sausage. shell chrome trim, chrome chips, leather cutting, leather dust, lobashi. Protein hydrolyzate is used in the form of an aqueous solution, which is prepared by dissolving a dry or coCt centered solution of the hydrolyzate in water for 0.5 h. Its use is not associated with the additional consumption of alkali or acid. Protein P1drolizat and its aqueous solution are stable during storage, after 10 days. storing the working solution of the hydrolyzate did not change its effectiveness, the microflora did not develop. All technological stages of obtaining rubber when used in

13 106542414

coagulant protein hydra- quality. The use of protein hydroli normally proceeds normally from high-lysate solves an important task of the protection of which productivity. Environmental rubbers obtained with the use of protein. In addition, the use of collagen belhydrolizate, which have excellent hydrolyzate, allows the utilization of physical and mechanical materials to show the leather tanning industry.

Claims (1)

(57G METHOD FOR ISOLATING SYNTHETIC RUBBERS FROM LATEXES by the action of an organic coagulant followed by separation of the resulting crumb of rubber mercury serum, characterized in that, in order to simplify the process technology and reduce the consumption of coagulant, 0.01-3% of the mass of protein rubber is used as the latter collagen hydrolyzate with a content of 0.7-20 wt.% carboxyl groups.