CS261547B1 - Mixed thermic and thermooxidizing stabilizator and process for preparing thereof - Google Patents

Abstract

The solution relates to mixed thermal and an aralkylated thermo-oxidizing stabilizer diphenylamines formed from 3 to 5 55% by weight. compounds of formula I CHq 'Ch $ (I) and 45 to 97% by weight of a compound of formula II Said mixture of substances is prepared so as to be diphenylamine is reacted with 2-methylstyrene at a ratio of 1: 1.3 to 2.0 ip for 1-3 hours at 90-140 ° C, under normal conditions pressure and insoluble in the reaction mixture catalyst containing montmorillonite and aluminosilicate. The solution is can be used in the chemical industry.

Description

Said mixture is prepared by reacting diphenylamine with 2-methylstyrene in a ratio of 1: 1.3 to 2.0 and a period of 1 to 3 hours at 90 to 140 ° C, under normal pressure and in the presence of an insoluble reaction mixture. a catalyst comprising montmorillonite and an aluminosilicate. The solution can be used in the chemical industry.

The invention relates to a mixture of an aralkylated, diphenylamine-based thermal and thermooxidizing stabilizer and a process for its preparation.

Most industrially produced polymeric materials and mineral oils need the presence of certain deliberately added substances to provide the desired stability during storage and processing, such as when exploded in finished products. These substances, so-called. the stabilizers retard or eventually inhibit undesirable oxidation phenomena in the substrate, so that it is not completely destroyed by oxygen, elevated temperature, UV radiation and mechanical stress.

A wide variety of antioxidant properties meet the above requirements. Among the best known and most commonly used are the group of amine antidegradants. The chemical structure of these compounds, which can be easily modified, makes it possible to obtain substances having the properties required for a wide range of different materials under processing or processing. exploitation conditions. Aminic antidegradants are commonly used as stabilizers of latexes, synthetic rubbers, polyolefins, oil polyamides as antidegradants in latex mixtures or dry mixtures based on rubbers of natural and / or synthetic origin.

Examples include naphthylamines. (Franta I .: Rubber raw materials, Prague SNTL 1978) alkylated diphenylamine derivatives (CS 190 838), p-phenylenediamine, or condensation products based on ketones and aniline, respectively. diphenylamine (Svoboda J .: Antidegradants for Rubber and Rubber, Gottwaldov 1975).

The mentioned substances have good protective properties, but their disadvantage is that they all intensively shame the protected substrate, they are objections to their health, other problems such as toxicity, carcinogenicity and allergic effects - naphthylamine and p-phenylenediamine derivatives, their production is raw and technological demanding, limited availability. In addition, they are not versatile and in many cases need to be modified before application

It has now been found that most of the above drawbacks are overcome by the mixed thermal and thermo-oxidizing stabilizer of the present invention, which consists of a mixture of aralkylated diphenylamines containing 3 to 55 wt. % of the compound of formula (I);

the said stabilizer is added to the substrate in an amount of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, and may be used together with other additives common to the substrate.

It has also been found that the substrate may be a non-stabilized synthetic rubber latex, a natural and / or synthetic rubber latex mixture, poly-alpha-olefins, polyamides and oils.

Further, a process for the preparation of a mixed stabilizer has been found, which comprises reacting diphenylamine with alpha-methyl styrene in a ratio of 1: 1.3 to 2.0 for 1 to 3 hours at a temperature of 90 to 14 ° C. normal pressure; and v. The presence of an insoluble catalyst in the reaction mixture comprising montmorillonite and an aluminosilicate.

The aralkyl diphenylamine of the present invention is a white crystalline powder or a pinkish scales with a low dustiness which significantly lesser the polymeric substrate. It is readily incorporated into the polymer substrate by conventional techniques, is non-toxic and easy to use base materials are available. The production itself is substantially less demanding in terms of raw materials, energy and overall technology than in the case of phenyl-beta-naphthylamine and p-phenylenediamine derivatives. Preferred final form - crystalline powder with minimum dustiness, resp. suitable finalized melt - allows the use of semi and fully automatic weighing system and subsequent immediate incorporation into the polymer substrate, eventually oil, without prior treatment.

Another advantage of aralkylated diphenylamine is the possibility of replacing the more expensive and less available p-phenylenediamine derivatives, the ketone-aniline condensation products, the alkylated diphenylamine derivatives (octyl-nonyl), or from the medical point of view, the disparate phenyl-beta-naphthylamine.

These examples illustrate but do not limit the scope of the invention.

Example 1

A 4-necked flask equipped with a condenser, dropping funnel, thermometer, and stirrer was charged with 25 g (0.1477 mol) of diphenylamine and included at 70 ° C. After pitch (I)

6 g of Montmorillomite catalyst are added to the diphenylamine.

After stirring the catalyst with diphenylamine and raising the reaction temperature to 105 ° C, 32.7 g (0.26586 mol) of alpha-methylstyrene is slowly added. After 3 hours, a mixture was obtained containing 91% 4,4'-bis (alpha, alpha'-dimethylbenzyl) diphenylamine and 9% 4- (alpha, alpha'-dimethylbenzyl) diphenylamine. After filtering the mixture, the filtrate solidified and was finalized by flaking .

Example 2

D, four-necked. A flask equipped with a condenser, stirrer, dropping funnel and thermometer is charged with 25 g (0.1477 mol) of diphenylamine, which is heated to 70 DEG C. After melting of the diphenylamine, 6 g of a montmorillonite-based catalyst are added.

After stirring the catalyst with diphenylamine and raising the reaction temperature to 105 [deg.] C., 23.3 g (0.1974 mol) of alpha-methylstyrene are slowly added and after 1 hour the reaction is complete and 49% 4,4'-bis (alpha) is formed. , alpha'-dimethylbenzyl) diphenylamine and 51% of 4-alpha, alpha'-dimethylbenzyl] diphenylamine, after filtering before solidification, are finalized by scaling or dissolving the mixture in a plasticizer into a rubber composition based primarily on mono-, di- and tri-aromatic hydrocarbons ( Furex 433) in a 1: 1 ratio.

Example 3

In a four-necked flask equipped with a stirrer, condenser, thermometer and dropping funnel was added 25 g (0.1477 mol) of diphenylamine, which was melted at 70 ° C. After melting, 6.5 g of Montmorillonite catalyst are added.

After stirring the catalyst with diphenylamine and raising the reaction temperature to 120 degrees Celsius, 32.728 g (0.265 86 mol) of alpha-methylstyrene is slowly added. After 2 hours, the reaction is complete and the resulting mixture consisting of 85% by weight, 4,4'-bis (alpha, alpha'-dimethylbenzyl) diphenylamine and 15% by weight of 4- (alpha, alpha'-dimethylbenzyl) diphenylamine is finalized by mixing with a plasticizer to the rubber compositions (as in Example 2) in a 1: 1 ratio.

Example 4

The alpha-methylstyrene diphenylamine based stabilizer of Example 2 was used at a concentration of 3.0% by weight to stabilize it. Chloroprene rubber vulcanisate according to the recipe:

chloroprene rubber (Neprene GSj 106.0 parts by weight stearic acid 0.5 parts by weight magnesium oxide 4.0 parts by weight zinc oxide 5.0 parts by weight carbon black, type HAF 50.0 parts by weight aromatic wetting agent 12.0 parts by weight

2-mercaptoimidazoline 0.5 wt. % tetramethylthiuram disulfide 0.5 wt. part

The vulcanizate was prepared by compression molding at 150 ° C. The course of thermo-oxidative sulfurization of thus prepared and stabilized vulcanizates was monitored on the basis of the change of basic material and physico-mechanical properties of test specimens in the stream of air at 130 ° C by the method according to ČSN 621511 for 1 to 5 days.

Used stabilizers:

1. 4-alpha, alpha-dimethylbenzyl diphenylamine

2. According to Example 2

3. Polymerized 2,2,4-trimethyl-1,2-dihydroquinoline

4. N-phenyl-N‘-isopropyl-p-phenylenediamine

Table 1

Thermo-oxidative aging, 130 ° C and dynamic fatigue of vulcanizates

Monitored parameter

Stabilizer 3,0 bsk 12 3 4

Residual strength (%) 2 days days days days

Residual elongation (%) 2 days days days days

83 69 75 81 77 88 65 75 71 76 58 66 65 74 51 53 62 69 52 60 50 56 36 49 43 52 29 38 32 40 21 31

8.9

10.8

8.8 (12.3

Crack formation according to de Mattia

The protective effect of the subject stabilizer exceeds the protective effect of commonly used stabilizers as well as the monoderivative itself.

Example 5

Vulcanizate modified from combination of natural and butadiene styrene rubber according to recipe {wt. Parts)

butadiene styrene rubber type 1 502 34 natural rubber type SMR-L 66 light mineral filler 70 zinc oxide 10.0 titanium dioxide 10.5 stearic acid 3.0 sulfur 2.0 N-cyclohexyl-2- -benztiazolsulfénamid 0.75 stabilized 2.0 wt. parts the stabilizer

and pressed to the optimum at 160 ° C

The course of thermo-oxidative aging was monitored according to CSN 62 15 11 at 90 ° C for 3 to 12 days.

Stabilizer used:

5. Based on alpha methyl styrenated diphenylamine according to example 1

6. Polymerized 2,2,4-trimethyl-1,2-dihydroquinoline

7. 4,4‘-Diethyl diphenylamine

8. Phenyl-beta-naphthylamine

9. N-phenyl-N‘-isopropyl-p-phenylenediamine

Table 2

He recorded the results of thermo-oxidative aging on the most significant changing properties - tensile strength and ductility; changes in the whiteness of the vulcanizates after exposure to UV radiation are shown in Table 3

Table 2

Thermooxidative aging those vulcanizates, 90 C

Monitored parameter stabilizer 6 7 8 - 1 4 5 residual 3 days 80 78 80 72 83 88 47 6 days strength 07 75 66 66 65 71 40 for 9 days 59 55 51 41 46 55 24 (%) 12 days 39 46 43 30 44 50 19 residual 3 days 81 88 90 83 78 78 80 elongation 6 days 79 78 78 76 70 76 74 9 days 98 70 68 62 63 70 60 12 days 56 64 56 56 '60 59 52 Stabilizing effect of the subject stabilizer is the most prominent. • Table 3 Change the surface whiteness vulcanizates after exposure UV radiation 0 to 8 hours (Leuko- meter,% MgO) Exposure time stabilizer h. 1 4 5 6 7 8 - 0 70 70 65 70 59 52 i68 2 49 47 35 49 36 33 54 4 44 44 29 44 23 24 48 8 40 41 27 38 18 19 43

The vulcanizate with the subject stabilizer approximates the unprotected vulcanizate to a degree of coloration.

Example 6

The alpha-methylstyrene diphenylamine-based stabilizer prepared according to Example 3 was dosed in the form of a solution in toluene in a conventional manner at a concentration of 1.0 wt. the effectiveness of the subject antioxidants by thermo-oxidative loading of the raw rubber at 130 ° C for 0 to 8 hours. The measure of the stripping efficiency is always the change in the viscosity of MOONEY ° ML 1 - 47100 ° C rubber, which occurs as a result of oxidation at higher temperatures.

Table 4

Viscosity MOONEY ° ML 1 - 47100 ° C SBR 1500 at 130 ° C

Stabilizer used Stress time hr.

1 2 3 4 5 6 delta

According to Example 3 53.5 54.0 52.5 53.0 53.5 53.5 0 phenyl beta naphthylamine, 1.5% 50.5 54.0 55.0 52.0 52.0 59.5 +3 mixed diphenyl-p-phenylenediamine. 0.75% 49.5 52.5 53.0 50.5 53.0 51.0 +1.5

The stabilizing effect of the subject stabilized stabilizers in their cross-linker is at the level of stabilizing effect levels of dosage.

Claims (2)

Mixed thermal and thermo-oxidizing stabilizer, characterized in that it consists of a mixture of aralkylated di-amines desirably from 3 to 55% by weight. compounds of formula I % Of the invention and 45 to 97 wt. compounds of formula II 2. A process for preparing a mixed stabilizer according to claim 1, wherein the diphenylamine is reacted with alpha-methylstyrene in a ratio of 1: 1.3 to 2.0 for 1 to 3 hours at a temperature of 90 to 140 ° C under normal pressure and in the presence of. in a reaction mixture of an insoluble catalyst comprising montmorillonite and an aluminosilicate.