RU2028312C1 - Method of stabilization of emulsion butadiene-methyl -styrene rubber - Google Patents

Abstract

FIELD: industry of synthetic rubber. SUBSTANCE: method of rubber stabilization involves addition of rubber to the latex before its isolation from aminophenolic stabilizing agent of the general formula R₁R₂C₆H₂(OH)(CH₂N / CH₂CH₂OH /₂ where R₁ - H, -CH₂N/CH₂CH₂OH/₂, -C₉H₁₉, -CH/CH₃/C₆H₅; R₂ - -C₈H₁₇, -C₉H₁₉, -CH/CH₃/C₆H₅, -C/CH₃/₂C₆H₅ at concentration 0.01-2.0 of rubber mass. EFFECT: improved method of rubber stabilization. 4 tbl

Description

 The invention relates to the production of emulsion synthetic rubbers, specifically to the stage of protecting rubber from thermal aging.

 Numerous stabilizers from various classes of organic compounds are known to protect rubbers from aging.

 One of the most universal stabilizers introduced at the stage of coagulation of latex rubbers is polyhexamethylene guanidine hydrochloride (metacid), used in an amount of 0.01-2% by weight of rubber, which ensures high stability of rubber under conditions of thermal aging (ICP is up to 100% ) However, rubbers contain a significant amount of gel (≥ 4.8%) and have a relatively low strength of vulcanizates (1).

 Closest to the invention is a method for stabilizing rubbers by condensation of alkyl-, arylalkylphenols with hexamethyltetraamine (BC-1 phenol-amine resins) (2).

 The disadvantage of this method is the low result from the introduction of the stabilizer BC-1. The stabilizing effect is determined through the plasticity conservation index (ICP), which in this case does not exceed 71%.

 The purpose of the invention is to increase the stability of rubbers during thermal aging.

^где
R₁= -H; -CH₂-N

, -C₉H₁₉, -CH(CH₃)C₆H₅,
-C(CH₃)₂C₆H₅;
R₂- -C₈H₁₇, -C₂H₁₉, -CH(CH₃)C₆H₅,-C(CH₃)₂C₆H₅, в количестве 0,01-2,0 мас.% на каучук.This goal is achieved in that dialkylaminomethylphenols of the general formula are introduced into the latex as stabilizers:

^Where
R ₁ = -H; -CH ₂ -N

, -C ₉ H ₁₉ , -CH (CH ₃ ) C ₆ H ₅ ,
-C (CH ₃ ) ₂ C ₆ H ₅ ;
R ₂ - -C ₈ H ₁₇ , -C ₂ H ₁₉ , -CH (CH ₃ ) C ₆ H ₅ , -C (CH ₃ ) ₂ C ₆ H ₅ , in an amount of 0.01-2.0 wt.% on rubber.

 These products are characterized by the following advantages: they are obtained from available raw materials, alkyl phenols - octyl (phenol, nonylphenol, arylalkylphenols) are used, their introduction increases the stability of rubbers, these products are liquids without the addition of foreign products (such as oils), unlike BC-1, effective coagulants and defoamers. They are also easily analyzed, unlike BC-1, using gas-liquid aromatography (GLC).

 The proposed products can be used both independently and in mixtures with known stabilizers.

 The following are the results on the synthesis and use of these products to stabilize rubbers.

 PRI me R 1. 2-Dioxyethylaminomethyl-4-nonylphenol (code VMS-40/1).

Condensation is carried out in two steps. First, 2 moles of diethanolamine are mixed with 2 moles of a 37% formaldehyde solution, incubated for 2 hours at room temperature, 220 g of paranonylphenol (1 mol) are added dropwise through a dropping funnel over 30 minutes, the mixture prepared above is kept in the reaction vessel at range of 30-35 ° ^C. The reaction is then continued under heating to 90-95 ^{° C} and stirring for 3 hours. The reaction mixture was cooled to room temperature, unreacted components are removed by distillation under reduced pressure (10-15 mm Hg).

 The resulting product is a mobile homogeneous transparent mass of faint yellow.

 The yield of the IUD-40/1 is 70%.

 Using gas chromatographic analysis, it was found that the product ВМС-40/1 consists of 98% of 2-dioethylaminomethyl-4-nonylphenol and 2% of 2,6-bis (dioxyethylaminomethyl) -4-nonylphenol.

 PRI me R 2. 2,6-Bis (dioxyethylaminomethyl) -4-nonylphenol (code ВМС-40/2).

 Condensation is carried out according to examples 1 and 2 of the description, using diethanolamine (4 mol), a 37% formalin solution (4 mol) and nonylphenol (1 mol) as the starting material.

 The product yield is 82%.

 PRI me R 3. 2,6-Bis (dioxyethylaminomethyl) -4-α-methylbenzylphenol (code ВМС-40/3).

Condensation is carried out in two steps. First, 428 g of diethanolamine and 324.3 g of a 37% formalin solution are mixed and kept at room temperature for about 2 hours. To 198 g of the product obtained from phenol alkylated with styrene, the mixture prepared above is added and the reaction mixture is kept at 35- for 2 hours 40 ^about C, and then another 6 hours in a boiling water bath. The resulting product is an oily mass of pale yellow.

 Similarly, products are obtained from 4-cumylphenol (waste in the production of phenol by the cumene method), 2,4-dinonylphenol (enriched fraction of dinonylphenol in the production of nonylphenol), octylphenol. Table 1 shows the data on the structure of stabilizers (examples for the 7th).

EXAMPLE EXAMPLE 8. prewarmed to 60 ^C. latices of styrene-butadiene rubber SCS-15 and 30ARKM butadiene rubber alfametilstirolnogo SKMS 30ARKM-27 administered products offered type IUD 40 in the form of an emulsion prepared according to the following recipe, by weight. h.: Product Navy-40 50 Oleic acid 2 30% formaldehyde solution 0.5 Distilled water 47.5
After 10 minutes of mixing, SKS-30 ARKM-15 and SKSM-30ARKM-27 are fed into the latexes of rubbers 15 and 27 parts by weight oil PN-6 and then add a 1% solution of sulfuric acid to pH 3.

 Coagulation is complete, serum is transparent.

 Control samples of rubbers SKS-30ARKM-15 and SKMS-30ARKM-27 are obtained with the well-known stabilizer BC-1, which is introduced into latexes in PN-6 oil, but when rubber is released, 200 kg of salt must be supplied per 1 ton of rubber.

Dedicated rubbers washed, dried and subjected to testing for resistance to thermal aging, defining therein preserve ductility index (COI%) Wallace plastometer at high-speed after aging at 140 ^{° C} for 30 min.

 The test results are presented in table.2.

EXAMPLE EXAMPLE 9. The oil-free butadiene latex SKS-30ARKP rubber, preheated to ⁶⁰ ° C, the product is administered IUD-40/2 in the amount of 1% on the rubber and after 10 min stirring a 1% solution of sulfuric acid to pH 3. There comes complete coagulation, serum is transparent.

 In a second sample with a dosage of the known stabilizer BC-30A, 1% per rubber is isolated by the product of ВМС-40/2 (0.3% per rubber) and 1% sulfuric acid.

 The third sample was isolated with the product ВМС-40/2 (0.3% per rubber) and 1% sulfuric acid. BC-1 in an amount of 0.2% per rubber is introduced into the polymer, as in sample 4.

Rubbers obtained was washed, dried and subjected to testing for resistance to heat aging at 140 ^{° C} for 30 min.

 The test results are illustrated in table 3.

 As can be seen from the data in Table 3, the Navy-40/2 is an effective stabilizer both independently and in a mixture with other stabilizers. In addition, the IUD-40/2 plays the role of a latex coagulant: when it is used, sodium chloride is not required.

 Table 4 shows some characteristics for rubber SKMS-30 ARKM-27 when using products of the type VMS-40 to stabilize it.

 From the results of Table 2 it can be seen that rubbers with the proposed products of the VMS-40 type have high resistance to heat aging, and vulcanizates based on them have high strength.

 In addition, the proposed Navy-40 products are effective defoamers and when dosed on rubber from 0.01-2%, the efficiency of defoaming is 75-83%.

Claims (1)

METHOD FOR STABILIZING EMULSION BUTADIENE- (α-METHYL) STYROL RUBBER by introducing an aminophenol stabilizer into rubber latex and then isolating the rubber from latex, characterized in that, in order to increase the stability of the rubber, we use dioxyethylaminoethylamine formula as a stabilizer

Where

-C ₉ H ₁₉ ; -CH (CH ₃ ) C ₆ H ₅ ;
R ₂ is -C ₈ H _{1 7} ; -C ₉ H _{1 9} ; -CH (CH ₃ ) C ₆ H ₅ ; -C (CH ₃ ) ₂ C ₆ H ₅ ,
in an amount of 0.01-2.0% by weight of rubber.

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