SU1541219A1 - Method of saltless extraction of oil-filled butadiene(metzyl)styrene rubber - Google Patents

Abstract

The invention relates to a method for salt-free separation of oil-filled butadiene (methyl) styrene rubbers, can be used in the production of synthetic rubber, and oil-filled polymer for the production of radial tires. Improving the distribution of oil, simplifying the process technology is achieved by the fact that in the method of salt-free release of oil-filled butadiene (methyl) styrene rubbers in latex stabilized with carbonic acid soaps, 3.0-5.0 kg / ton of recoverable rubber latex of butadiene copolymer with styrene are introduced , methyl methacrylate and methacrylic acid, containing 35% carboxyl groups. The mixture of latexes is kept for 30–180 minutes, after which mineral oil, containing 3.5–4.0 wt.% Of synthetic fatty acids, a coagulating additive, and a mineral acid, is introduced successively into the mixture. 5 tab.

Description

The invention relates to the salt-free separation of synthetic rubbers from latexes and can be used in the manufacture of synthetic rubbers in the petrochemical industry, and oil-filled rubber can be used, in particular, to produce radial tires.

The aim of the invention is to improve the distribution of the oil, simplifying the process technology.

In the method of isolation, an additive is used - a high carboxylated latex (BSMK) containing, in weight, h .: butadiene 20.0; styrene 25.0; methyl methatrylate 20.0; methacrylic acid 35.0; sodium alkyl sulfonate 4.0; tert-dodecyl mercaptan 1.0; potassium persulfate 0.05; rongalite 0.05; Trilon B 0.06, water 300.

The method is carried out up to 98% conversion. The polymerization temperature is 15 ° C, time 11 hours. The molecular weight of the copolymer is 100,000. With a different content in the copolymer of carboxyl groups, the contents of butadiene and styrene vary.

Example 1. 50 ml butadiene (methyl) styrene latex (dry residue 20.5%) are placed in a flask, 0.04, 0.08, 0.24, 0.40, 0.8, 1.2 ml of BSMK latex are introduced. (dry residue

sd

4 S

with

31

25%). The content of carboxyl groups in the BCMK copolymer varies from 15 to 55%. At certain time intervals at room temperature, the surface tension of butadiene (methyl) styrene latex in each flask is measured on a Dewey device.

The results of determination of the surface tension of the SKMS-ZOARKM-2 latex are given in Table. one.

In flasks containing latex SKMS-α-SOARKM-27 and high carboxylate latex (BSMK) with a carboxyl group content of 35%, 30-180 minutes after the introduction of BSMK, 3.8 g of PN-6 oil (27%) are added with stirring rubber “The contents of each flask are heated to 60 ° С before oil is introduced.

The oil introduced into the latex contains 0.15 g (; 0 wt.% Based on the amount of oil) of synthetic fatty acids (FFA). Emulsifier (LF) is well dissolved in oil, therefore, this operation does not require significant time and equipment. It is possible to supply FLC to the oil tank; it is possible to inject FLC into the line of oil entering the coagulation apparatus. Formed latex oil on the mixture.

Uniformity of the distribution of oil &npvi; rotation speed of the stirrer 200 rpm; oil content in latex,%: top of apparatus 28; the bottom of the apparatus is 26.5, with the stirrer rotating speed of 300 rpm, the oil content,%: bottom of the apparatus is 27.81, top of the apparatus

27.5.

To the latex-oil mixture, 7 ml of a 1% solution of synthetic coagulant dimethyl-3,5-di-tert-butyl 1-hydroxybenzylamine, which is 0.5% by weight per emitted rubber, are successively added; 5 ml of 2% sulfuric acid. Time from oil injection to acid addition min

In each flask, the quality of the rubber crumb formed is visually assessed. its stickiness and even distribution of oil in it

The research results are shown in the scoreboard 2 (experiments 1-13)

Example 2 (control), by a known method). In the same conditions as in example 1, the experiment was carried out using anionic polyelectrolytes used in a known method with sodium salts of polnacryl

,

50

5 n

.

50

0

194

acid and copolymer of butyl methacrylate with methacrylic acid,

In tab. Table 2 shows the results of coagulation of the SKMS-ZOARKM-27 latex (experiments 14-19). The oil is introduced without emulsification, in contrast to the known method.

Example 3 (by a known method). The salt-free release of oil-filled SKS-ZOARKM-15 rubber is carried out by a known method. 10 liters of SKS-ZOARKM-15 latex with a dry residue of 20% are placed in a coagulation apparatus with a stirrer and heating. While stirring, 5 bO ml of a 65% emulsion of PN-6 oil, prepared in a separate unit, is added to the latex, which makes up 15 wt0% of the released rubber. Then, 117 ml of a 1% sodium polyacrylate solution is added to the latex-oil mixture, which is 0.05% by weight per emitted rubber. The contents of the apparatus are mixed, after which 70 ml of a 1% aqueous solution of PEP are poured into the apparatus, which amounts to 0.2% for the released rubber and then 330 ml of 10% sulfuric acid. The resulting rubber crumb is separated from the serum, washed with water and dried at 80 ° C. The results of the observations are given in table. 2 and 3.

Example A. The SKMS-ZOARKM-27 rubber-free separation of rubber was carried out according to example 3 with the only difference that the SCMS-ZOARKM-27 butadiene (methyl) styrene latex was used with a dry residue of 22%, and the amount of emulsion oil introduced as an emulsion -6 is 810 g (abs), which is 27 wt.% Per release rubber.

Visual observations: adding an oil emulsion to the latex and stirring for 5 minutes formed a homogeneous latex oil on a light yellow emulsion without visible drops of oil.

Example 5. Solventless release of oil-filled butadiene (methyl) styrene rubber SKMS-ZOARKM-27.

10 l of SKMS-ZOARKM-27 styrene latex butadiene (methyl) with a dry residue of 22% is loaded into an apparatus equipped with a stirrer and a jacket for heating. To the latex, add kl + ml of 75 BCMK latex with 35 carboxyl groups added that the old em 5.0 kg dry

C 12 C 1 "

515

polymer to 1 ton of rubber (dry residue).

30 minutes after the late addition of BSMK (holding time), the contents of the apparatus are heated to 50 ° C and 810 g of PN-6 oil, which contains 33 g (or C may / o) of synthetic fatty acids fraction, are loaded into the apparatus.

2100 ml of a 1% solution of synthetic coagulant dimethyl-3,5-di-tert-butyl-4-hydroxybenzylamine (OM) is added to the obtained homogeneous latex-oleaginous mixture, which amounts to 0.7 wt.% rubber. OM at the same time serves as a rubber stabilizer.

The coagulation of the latex-oil mixture is carried out with a 2% solution of sulfuric acid at pH 3.0.

Oil-filled rubber is excreted in the form of a non-sticky crumb with a grain size of 3.7 mm. The rubber crumb is separated from the serum, washed three times with wet water, dried, and dried at 80 ° C.

Surface tension of latex before putting oil into it 49.

Visual observations: after the oil was introduced into the latex and the mixture was stirred for 5 minutes, a homogeneous latex-oil was formed on a light yellow emulsion without visible drops of oil.

Example 6; The SKMS-ZOARKM-27 rubber-free release of rubber is carried out according to example 5 with the only difference that natural coagulating additive Belkozin M, which is a protein hydrolysis of collagen, is used in the amount of 5.0 kg per 1 ton of released rubber. .

A mixture of the products neoson D and BC-1 is used as a rubber stabilizer.

The coagulation conditions and observations are the same as in example 5.

Example 7. Salt-free release of styrene-butadiene oil-filled rubber SKS-ZOARKM-15.

10 l of styrene-butadiene SCS-ZOARKM-15 latex containing 20% of dry matter is loaded into the apparatus with a stirrer and a jacket for heating. With stirring, add 2k ml of 25% BSMK latex containing 35% carboxyl groups to the latex, which is 3 kg of dry polymer

five

0

five

about

Q

0

five

ig6

ra per 1 ton of rubber (dry residue). 60 minutes after the addition of the BMSP latex, the contents are heated to 50 ° C and 350 g of oil PN-6 containing 12 g of synthetic fatty acids fraction C, g-Cu, which is 3.5 wt.% And 7 g of stabilizer, are loaded into the apparatus. BC-1 rubber. Exposure time of the mixture of latex SKS-ZOARKM-15 with BSMK latex 60 min.

Surface tension of the latex before putting in the oil 48 dN-cm 1

Visual observations: after adding the oil to the latex and mixing the mixture for 5 minutes, a uniform latex-oil was formed on a light yellow emulsion without visible drops of oil.

To the resulting homogeneous latex-oil mixture, 590 ml of a 2% solution of sodium lignate is added, which is 0.5% for the liberated rubber, and 236 ml of a 2% aqueous solution of polyethylene polyamine (PEPA), which is 0.2% on released rubber.

A 2% solution of sulfuric acid is then added to the latex to a pH of 3.5 °.

Oil-filled rubber is excreted in the form of a non-stick homogeneous crumb. The rubber crumbs are separated from the serum, washed three times with water and dried at 80 ° C.

Example 8. The SKS-α-SOARKM-15 oil-free rubber SKA-15 rubber was isolated as described in Example 7 with the only difference that an alkaline solution of methyryl acid and maleic anhydride butyl ester and maleic anhydride copolymer was used in a quantity of 0.05 May. from the mass of emitted rubber. The coagulation conditions and observations are the same as in example 7.

The rubbers obtained according to the examples are subjected to physical and mechanical tests.

The composition of the vulcanizates based on rubber SKMS-ZOARKM-27 (100.0) wt.h.:.

Zinc Oxide5.0

Altax2.75

Soot marks

DG-100 40.0

Sulfur2.0

The properties of the vulcanizates are given in table. four.

The composition of the vulcanizates on the basis of SKS-ZOARKM-15 rubber (100.0), m.ch .:

Stearic acid 2.0

Zinc Oxide5.0

Altax1.5

Diphenylguanidine 0,3

Soot brand DG-100 50.0

Sulfur2.0

Claims (1)

The properties of the vulcanizates are given in table. 5. The invention formula Method for salt-free release of oil-filled butadiene (methyl) styrene rubbers by introducing into the latex rubber stabilized carboxylic acid soaps, oils, $ 12198 adjusting additives and mineral acid, characterized in that, in order to improve distribution,. oil, simplifying the process, initially introducing 3.0 to 5.0 kg / ton of recovered rubber latex of a copolymer of butadiene with styrene, methyl methacrylate and methacrylic acid, containing 35% carboxyl groups, with keeping the mixture of latexes for 30 to 180 minutes, after which the mixture is injected in succession with mineral oil containing 3.5%, 0% by weight of synthetic fatty acids, a coagulating additive, and a mineral acid. Table 1 ten similar latex CMS-ZOARK 15 20 35 50 30 60 120 30 60 120 five ten 20 thirty 60 120 180 ten 30 60 55 ten 68.0 30 60 ABOUT , 2 3 C 5 6 7 agul - qi 62.5 Dotted coagula qi Dot coaguli qi Oil drops are formed on the surface of the latex. The rubber is excreted in the form of sticky, oil-covered chips, which are knocked out in Also Forms a homogeneous latex-oil on a mixture of yellow color without inclusions of oil droplets. The rubber is excreted in the form of a non-stick homogeneous crumb. rub (known method) 21 Also these oils and mixing formed a uniform latex-oil on a light yellow emulsion without visible drops of oil Also Table 3 u It characterizes the homogeneity and stability of the mixture, the distribution of oil. The ratio of latex (dry residue): oil 70:30 us.ch. The ratio of latex (dry residue): oil mac.ch. Table Mooney Viscosity, MB,. "100 Conventional tensile strength, MPa With the same drying time of the samples. I 5.5 five  With the same drying time.