CS274292B2 - Retader of double bond containing rubbers' vulcanization - Google Patents

Description

The invention relates to the use of substituted N-trichloromethylthiohydantoins as vulcanization retardants in combination with bis- (2,4-diamino-s-triazin-6-yl) oligosulfides in vulcanizable rubber compositions which increase crosslink density.

A variety of vulcanization accelerators are available for crosslinking elastomers with sulfur whose vulcanization characteristic is not sufficient in itself, which, when added in small quantities, not only greatly increase the achievable crosslinking density, but also greatly improve the crosslinking kinetics, so that the vulcanization process can be rationally also on an industrial scale.

Although the crosslinking of the rubber mixtures can also be carried out without free sulfur, for example by peroxides or thiurans, the invention relates to accelerated sulfur vulcanization and crosslinking by N, Ν'-substituted bis- (2,4-diamino-s-triazine-6- yl) -oligosulfides of formula II below, wherein n is 4 without free sulfur. In this case, the index n is 4 not only for tetrasulphides but also for mixtures of compounds of the formula II, in which case n = 4 refers to the mean statistical chain length S _n ·

The most important sulfur vulcanization accelerators are benztriazole-based mercaptans, disulfides and sulfenamides. The corresponding triazine-based compounds described in DE 1 669 954 and DE 1 298 706 are similar in activity. N, Ν'-substituted bis- (2,4-diamino-s-triazine-6) also belongs to the same category. -yl) -oligosulfides wherein n = 4 of formula II described below which, in contrast to the above accelerators, cross-link even without the addition of free sulfur to form cross-linking structures of the -S-, -SS- and -SS _X -S type.

The vulcanization process of accelerated sulfur vulcanization can generally be broken down into three phases, which include the incubation time of the crosslinking reaction, the crosslinking process itself, which is characterized by the rate constant and the yield of the crosslinking, and the superheating period.

The above accelerators generally differ in their behavior in all three phases.

For the safety of rubber compound processing, especially when the processing temperature must be increased to increase productivity, the incubation period of the vulcanization reaction is prolonged by so-called vulcanization retardants, also referred to as pre-vulcanization inhibitors. Santoguard PVI (N-cyclohexylthiophthalimide, CD Trivette et al., Rubber Chem. Technol. 50, 570 (1977), Monsanto, US Patent No. 3) has proven to be effective in practice in retarding sulfur vulcanization in the presence of sulfonamides (R). 427 319, 3 546 185,

752 824, 3,855,262) and in the case of benzthiazolyldisulfide, preferably Vulkalent E (Bayer AG, N-phenyl-N- (trichloromethylsulfenyl) benzenesulfonamide, DE-OS 1 957 484).

It is an object of the invention to improve the vulcanization characteristics of vulcanizable rubber compositions.

SUMMARY OF THE INVENTION The present invention provides a vulcanization retarder of rubbers containing double bonds with an effect of increasing crosslink density for use in systems comprising oligosulfide compounds of formula II as accelerators and / or crosslinkers

where

R ⁷ represents a hydrogen atom,

R represents a hydrogen atom or a benzyl group, each of 2 3 4

R, R and R are C 1 -C 8 alkyl, allyl, C 3 -C 8 cycloalkyl optionally substituted with 1 to 3 methyl, 2-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl or

R ³ and R 6 together represent an alkylene group having 4 to 6 carbon atoms or a group of the formula

- (ch ₂ -chx) ₂ y wherein X is methyl or hydrogen and Y is oxygen or sulfur and n is 2 or 4, or mixtures of compounds of formula II wherein (S) _n is a sulfur chain having a mean statistical length corresponding to n = 4, and optionally containing additional sulfur donors, characterized in that it consists of a hydantoin of formula I

where each of the symbols

R (R) and R (R), which may be the same or different, are hydrogen, (C1-C6) -alkyl, benzyl or phenyl; or

R® and R® together represent a closed methylene chain of 4 to 6 carbon atoms, the ring formed optionally being mono- or di-substituted by a methyl group.

Pure linear tetrasulfides between the two substituted triazine residues are prepared by reacting an aqueous alkaline solution of the corresponding N, Ν'-substituted 2,4-diamino-6-mercaptotriazines in a two-phase system with a sulfur trichloride solution (S ₂ Cl ₂ ) in an inert organic solvent in which the reaction product is insoluble or sparingly soluble, at a temperature in the range of -5 ° C to <20 ° C, preferably at 10 ° C. Preferably, an alkaline aqueous solution of mercaptotriazine is produced which contains the alkali hydroxide in at least a stoichiometric amount relative to the reaction. Preferably, the alkaline solution contains an excess of alkaline hydroxide of 1 to 20 mol%, based on the mercaptotriazine used.

This solution is mixed with a solvent in which the end product of the reaction is insoluble or sparingly soluble, preferably with C 5 -C 10 alkanes or C 5 -C 8 cycloalkanes optionally substituted by 1 or 3 methyl groups mixtures. The resulting mixture is vigorously stirred and cooled, preferably to + 10C and sulfuric chloride (S ₂ Cl ₂ ) in the solvent used is added dropwise while cooling. Sulfur trichloride is used at a ratio of at least 2 moles of mercaptotriazine per mole of sulfur trichloride, but depending on the excess of alkali, this ratio may also be 2: 1.1 to 1.2.

Under these conditions, sulfur trichloride (S2Cl2) acts exclusively condensation.

The product is separated in a manner known per se and dried, preferably at a temperature of up to 50 DEG C. under vacuum (1.3 kPa).

Mixtures consisting of the oligosulfide compounds of formula II can also be used

where

3 4

R, R, R and R are as defined above and (S) represents a sulfur chain with a mean statistical chain length corresponding to n = 4.

These oligosulfide mixtures, also referred to hereinafter as disproportionates, as they are prepared by the diproporation of the tetrasulfides of formula II, can be prepared by various methods.

The reaction conditions must be controlled in such a way that no free sulfur is formed.

One method is characterized in that the isolated tetrasulfide of the formula II is heated above its melting point, preferably by 20 to 50 ° C.

In another method, the tetrasulfide of formula (IX) is dissolved in an inert organic solvent and the disproportionation reaction is carried out at a temperature in the range of 20C (the solution is allowed to stand at room temperature) to the boiling point of the solvent used.

A particularly elegant method is to react an aqueous alkaline solution of the corresponding N, N'-substituted 2,4-diamino-6-mercaptotriazone in a two-phase system with a solution of sulfur trichloride in an inert organic solvent in which the tetrasulfide formed is soluble. The resulting linear tetrasulfide then immediately disproportionates to the composition of the invention.

Particularly suitable solvents are chlorinated hydrocarbons, for example methylene chloride or chloroform, but ethers, esters, aromatic hydrocarbons and ketones are also suitable for the disproportionation reaction in the absence of water. Alternatively, they can be used to form a two-phase mixture with water. The reaction conditions for the production of disproportionates are otherwise identical to those for the preparation of pure tetrasulfides.

The degree to which the disproportionation reaction has progressed is not relevant to the eligibility of the resulting mixtures. Only disproportionation should not produce any free sulfur.

It has been shown that the combined use of the compounds of formula I and II not only results in a strong retardation of vulcanization, but at the same time changes the vulcanization characteristic in that all physical properties related to crosslink density such as maximum torque are greatly improved. (rheometer) or voltage value at 300% elongation.

Preferred compounds of formula I are, for example, the following:

VZ g 3-trichloromethylthio-5,5-dimethylhydantoin

VZ h 3-trichloromethylthio-5-benzylhydantoin

3-Trichloromethylthio-5-n-propylhydantoin

VZ to 3-trichloromethylthio-5-isopropylhydantoin

VZ 1 3-Trichloromethylthio-5-pentamethylenehydantoin.

These substances are known. (Kittleson, Science 115, 84 (1952), U.S. Patent No. 2,553,770 to G. P. Lamson and H.O. Singher, J. Org. Chem. 21, 684-685). They have a strong fungicidal and partly bactericidal action. They can be prepared from the corresponding hydantoins and trichloromethylsulfenyl chloride in the presence of an acid acceptor.

The N, N '-substituted bis- (2,4-diamino-s-triazin-6-yl) -disulfides of the formula II are described in DE patent No. 1669954. Examples are bis- (2-ethylamino-4). -diethylamino-s-triazin-6-yl) disulfide; and bis- (2-ethylamino-4-di-n-isopropylamino-s-triazin-6-yl) disulfide.

Examples of other N, N ' -substituted bis- (2,4-diamino-s-triazin-6-yl) tetra] oligosulfides of the formula II include, for example:

N bis- (2-ethylamino-4-diethylamino-triazin-6-yl) -tetrasulfide A bis- (2-ethylamino-4-di-isopropylaraino-s-triazin-6-yl) tetrasulfide B bis- (2-n) Bis- (2-isopropylamino-4-di-isopropylamino-s-triazin-6-yl) tetrasulfide D bis- (2-ethylamino-4-di) -butylamino-4-diethylamino-s-triazin-6-yl) tetrasulfide bis- (2-ethylamino-4-di-n-propylamino-s-triazin-6-yl) tetrasulfide E bis- (2-n-propylamino-4-diethylamino) -isobutylamino-s-triazin-6-yl) tetrasulfide bis- (2-n-propylamino-4-di-n-propylamino-s-triazin-6-yl) tetrasulfide G bis- (2-N-butylamino-4-dl) -s-triazin-6-yl) tetrasulfide bis- (2-ethylamino-4-di-n-butylamino-s-triazin-6-yl) tetrasulfide-bis-(2-isopropylamino-4-di-n-propylamino-s-triazin-6-yl) tetrasulfide -isopropylamino-s-triazin-6-yl) oligosulfide mixture L bis- (2-cyclohexylamino-4-diethylamino-s-triazin-6-yl) oligosulfide mixture M bis- (2-ethylamino-4-diethylamino-s) -triazin-6-yl) oligosulfide mixture O bis- (2-amino-4-diethylamino-s-triazin-6-yl) oligosulfide mixture.

The substituted N-trichloromethylthiohydantoins used in combination with the N, Ν'-substituted bis- (2,4-diamino-s-triazin-6-yl) sulfides of formula II as vulcanization retardants which simultaneously increase the crosslinking value are: suitable for prior art rubber compositions comprising natural rubber (NR), isoprene rubbers (IR), butadiene rubbers (BR), styrene-butadiene rubbers (SBR), isobutylene-isoprene rubbers (IIR), ethylene-propyleneDM terpolymers nitrile rubbers (NBR), halogen-containing rubbers, as well as epoxidized natural rubbers (ENR) and mixtures thereof.

In order to extend the possibilities of variation in the vulcanization kinetics, it may be expedient to use the triamine accelerators of the formula II in the form of mixtures of two or more individuals, while maintaining the abovementioned amounts used, particularly preferred molar ratios.

Also, for reasons of kinetics, it may be useful to use N, Ν'-substituted bis- (2,4-diamino-triazin-6-yl) -oligosulfides of the formula II in a mixture with conventional accelerated or benzthiazole series and / or thiuranes such as e.g. with benzthiazolsulfenamide, benzthiazolyldisulfide, 2-mercaptobenzthiazole or their zinc salts or tetramethylthiuram disulfide (see also J. van Aplhen, Rubber Chemicals (1977), pp. 1-46).

Using the above dosage, important vulcanization problems can be solved without compromising the properties of the vulcanizates.

The N, Ν'-substituted bis- (2,4-diamino-s-triazin-6-yl) oligosulfides of the formula II can be advantageously used together with organosilanes, for example compounds of the formula [(RO) ₃ Si - (CH ₂₎ ) _n ] ₂ - S _x or (RO) ₃ Si (CH ₂ ) _n - SH (IV), wherein n is 2 or 3 x is 2 to 6 and

R is C 1 -C 6 alkyl or cycloalkyl; or V

wherein x represents the number 2 to 6, preferably 3 a

R is methyl or ethyl, preferably with bis- (3-triethyloxysilylpropyl) -tetrasulfide (Si 69, Degussa AG), when crosslinked in the absence of sulfur with Si 69 (DE Patent No. 25 36 674), when sulfur cured the use of Si 69 (DE patent 22 55 577) and also in the production of reverse-stable vulcanizates by designing equilibrium curing systems according to DE patent 28 48 559. In all the above cases, substituted N-trichloromethylthiohydantoins of formula I function as suitable vulcanization retardants at the same time the crosslink value.

Substituted N-trichloromethylthiohydantoins of formula (I) also exhibit a retarding effect on vulcanization even when the N, Ν'-substituted bis- (2,4-diamino-s-triazin-6-yl) oligosulfides of formula (II) are used alone or in mixtures with conventional accelerators and / or conventional sulfur donors, such as Sulfasan ¹ R (morpholinedisulfide).

Substituted N-trichloromethylthiohydantoins are used as retardants which simultaneously increase crosslink density in combination with the N, N'-substituted bis- (2,4-diamino-s-triazin-6-yl) oligosulfides of formula II in rubber mixtures which as other conventional components of the mixture they may contain

- reinforcing systems, ie retort carbon black, gas black, lamp black, thermal black, acetylene black, arc black, CK black, etc., as well as synthetic fillers such as silicas, silicates, alumina hydrates, various types of carbonate calcium and natural fillers such as clays, siliceous chalks, chalks, talc, etc., and silane-modified fillers and mixtures thereof in an amount of 5 to 300 parts per 100 parts of rubber,

- zinc oxide and stearic acid, as vulcanization promoters, in an amount of 0.5 to 10 parts per 100 parts of rubber,

- commonly used antioxidants, anti-ozonants and anti-fatigue agents such as IPPD, TMQ, etc., as well as waxes as light stabilizers, and mixtures thereof,

- any plasticizers such as aromatic, naphthenic, paraffinic or synthetic plasticizers and mixtures thereof,

optional organosilanes known and used in the rubber industry, such as gamma-chloropropyltrialkoxysilanes, vinyltrialkoxysilanes, gamma-mercaptoalkyltrialkoxysilanes and aminoalkyltrialkoxysilanes, and mixtures thereof, in an amount of from 0.1 to 25, preferably from 1 to 10 parts per 100 parts of fillers carrying silane groups such as silicas, silicates, clays, etc.,

- colorants and processing aids, if any, in the usual dosage.

The range of applications in which rubber mixtures containing substituted N-trichloromethylthio-hydantoins of formula I may be used in combination with N, Ν'-substituted bis- (2,4-diamino-s-triazin-6-yl) -oligosulfides formula II, includes use in the manufacture of tires, in the manufacture of technical products such as conveyor belts, V-belts, molded products, hoses with or without liner, rolled rubber products, linings, injection molded profiles, foils, bottoms and uppers of shoes, cables and solid rubber hoops.

The production and vulcanization of the rubber mixtures takes place in a manner known per se and under conventional conditions.

Example 1

454 g of 2-ethylamino-4-diethylamino-6-mercaptotriazine are dissolved in a sodium hydroxide solution prepared from 84 g of sodium hydroxide and 1.5 liters of water.

Place the solution in a 4-liter three-necked flask, add 1.5 liters of light petrol (boiling point 80 to 110 ‘C) and cool to 0 ° C with vigorous stirring.

137 g of sulfur trichloride (S-Cl) in 100 ml of petrol are added to the mixture over 20 minutes, taking care that the temperature does not exceed +5 ° C.

Tetrasulfide is precipitated immediately. After completion of the reaction, the mixture was stirred for a further five minutes and then the product was filtered off and washed.

The fine snow-white powder is dried at 40-45 ° C under a vacuum of 15 mm Hg.

Yield: 499.5 g (97.1% of theory);

Analysis:

bis- (2-ethylamino-4-diethylamino-s-triazin-6-yl) -tetrasulfide, molecular weight 516, ^C 18 ^H 32 ^N 10 ^S 4 calculated: C 41.9; H, 6.2; N, 27.1; S, 24.8. Found: C, 41.8; H, 6.5; N, 26.8; S, 24.8.

TLC and HPLC analysis indicated that the product contained 97.1% linear tetrasulfide.

Example 2

56.6 g of 2-ethylamino-4-di-n-butylamino-6-mercaptotriazine are dissolved in a solution of 8.8 g of sodium hydroxide in 250 ml of water. 250 ml of gasoline was added to the mixture, and the resulting mixture was cooled to 5 ° C with good stirring. A solution of 13.5 g of sulfur trichloride (SCCl ^) in 30 ml of gasoline was then added. Immediately a white deposit is formed. After completion of the reaction, the reaction mixture was worked up as in Example 1. The yield was 56 g, corresponding to 89.2% of theory.

Analysis: ^C 26 ^H 48 ^N 10 ^S 4 (MW 628) calculated: C 49.68; H, 7.64; N, 22.29; S, 20.38;

Found: C, 49.59; H, 7.59; N, 22.18; S, 20.40.

HPLC-analysis: degree of purity 796%.

Example 3

107.6 g of 2-i-propylamino-4-diisopropylamino-6-mercaptotriazine are dissolved in sodium hydroxide solution by preparing from 17.6 g of sodium hydroxide and 600 ml of water, and 600 ml of methylene chloride are added thereto.

27 g of sulfur trichloride (SjCl 3) in 50 ml of methylene chloride are added to the mixture at 0 to 5 ° C. After completion of the reaction, the organic phase was separated in a separatory funnel, dried and evaporated in vacuo. An amorphous powder having a softening point of 90 DEG C. is obtained.

Yield: 112.5 g (94%).

Analysis: ~ 24 ^ 44 ^ 10 ^ 4 (MW 600) calculated: C 48.0; H, 7.33; N, 23.3; S 21.3;

Found: C, 48.2; H, 7.36; N, 23.01; S, 20.95.

Example 4

45.4 g of 2-ethylamino-4-diethylamino-6-mercaptotriazine are dissolved in a solution of sodium hydroxide prepared by dissolving 8.8 g of sodium hydroxide in 200 ml of water. 200 ml of methylene chloride are added. The mixture was cooled to 0 DEG C. with stirring with a turbine stirrer.

14 g of sulfur trichloride (S2Cl2) are dissolved in 50 ml of methylene chloride and the resulting solution is added to the mercaptide solution.

The reaction product was dissolved in methylene chloride. After completion of the reaction, the phases were separated and the methylene chloride solution was worked up. An amorphous powder is obtained with a softening point of about 110 ° C.

Yield: 46.7 g (90.5% of theory).

Analysis: C ^ gHH NN ^OSS (MW 516) calculated: N 27.1; S, 24.8;

Found: N, 26.8; S 24.4.

According to TLC analysis, the mixture contains 4 oligosulfides but no free sulfur.

Example 5 g of bis- (2-ethylamino-4-diethylamino-s-triazin-6-yl) -tetrasulfide having a degree of purity of 97.1% are placed in a round-bottomed flask and heated in an oil bath for 1 hour at room temperature.

160 c. After cooling, the melt solidifies to an amorphous substance. According to TLC analysis, proCS 274292 B2 product contains three additional oligosulfides in addition to 50% of the starting product.

Example 6

70.25 g of 2-cyclohexylamino-4-diethylamino-6-mercaptotriazine are dissolved in a solution of 11 g of sodium hydroxide in 250 ml of water and 250 ml of chloroform are added. With vigorous stirring, a solution of 16.8 g of sulfur trichloride (S-ClCl) in 30 ml of chloroform is added.

After completion of the reaction, the phases were separated and the chloroform layer was worked up. 71.9 g of white amorphous powder are obtained, corresponding to 92% of theory.

Analysis: ^C 26 ^H 44 ^N 10 ^S 4 (Molecular Weight 624) Calcd: C 50.0; H, 7.05; N, 22.4; S 20.51;

Found: C, 49.1; H 6.90; N, 21.8; S 20.0.

According to TLC analysis, the product consists of about 30% linear S-product and 70% oligosulfides, but contains no free sulfur.

Test standards

The physical properties were tested at room temperature according to the following standards:

units voltage at 300% elongation DIN 53 504 MPa incubation time t ^ DIN 53 529 min the vulcanization time of the mixture (scorch time) ASTM D 2084 min Shore A hardness DIN 53 505 degree D -D. max min DIN 53 529 Nm

Names and abbreviations have the following meaning in the application examples: RSS Ribbed Smoked Sheet (natural rubber)

CORAX N 220 soot, surface area (BET) 120 m ² / g (Degussa)

Naftolen

Vulkanox

Vulkanox (R) (R)

Mesamoll

ZD hydrocarbon softener

4010 NA N-isopropyl-N'-phenyl-p-phenylenediamine poly-2,2,4-trimethyl-1,2-dihydroquinoline ester of alkylsulfonic acid and phenol and cresol antiozonant wax benzthiazolyl-2-morpholino-sulfenamide N-phenyl- 3-trichloromethylthio-5,5-dimethylhydantoin 3-trichloromethylthio-5-benzylhydantoin N - (trichloromethylsulfenyl) benzenesulfonamide precipitated silica (Degussa) granulate bis- (2-ethylamino-4-diethylamino-s-triazin-6-yl) disulfide

HS

Protector ^(R) G 35 Vulcacite ^(R 'MOZ Vulcalent ^1R) E Ultrasil ^(R) VN 3 gran.

V 143

VZ g

VZ h

VZ i

VZ k

VZ 1

V 225

Sulfasar ( ^R ) R

3-Trichloromethylthio-5-n-propylhydantoin

3-Trichloromethylthio-5-isopropylhydantoin

3-Trichloromethylthio-5-pentamethylenhydantoin bis- (2-isopropylamino-4-diisopropylamino-s-triazin-6-yl) disulfide morpholinedisulfide.

Example 7

Evidence of the effect of various hydantoins in combination with bis- (2,4-diamino-s-triazin-6-yl) tetrasulfide as accelerator (N) in carbon black-filled mixtures mixture number 1 2 34567

RSS, 1, ML (1 + 4) = 70-80 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! CORAX N 220 50 50 50 50 50 50 50 ZnO RS 5 . 5 ' 5 5 5 5 5 stearic acid 2 2 2 2 2 2 2 Naftolen ZD 3 3 3 3 3 3 3 Protector G 35 1 1 1 1 1 1 1 Vulkanox HS 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Vulkanox 4010 NA 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Vulkacit MOZ 1.43 - - - - - - N - 1.5 1.5 1.5 1.5 1.5 1.5 VZ g - - 0.75 - - - - VZ h - - - 0.91 - - - VZ i - - - - 0.78 - - VZ k - - - - - 0.78 - VZ 1 - - - - - - 0.85 sulfur 1.5 0.8 0.8 0.8 0.8 0.8 0.8 ^D max ^D min ⁽¹⁷ ° ^C) 8.65 7.03 8.26 7.84 7.67 7.91 7.61 ie (170 ° C), min 4,5 2.9 4,5 4.0 4.0 4.1 4.0 ie (130 ’C), min 22.5 9.5 21.8 21.0 21.0 21.5 22.0

vulcanizate properties at 170 ° C stress at 300% elongation 10.2 10.6 11.2 11.3 11.2 11.4 11.3

Example 7 shows that the addition of N-trichloromethylthiohydantoin to the tetrasulfide triazine as an accelerator achieves an increase in the vulcanization time (mixtures 2 to 7), so that this value is increased to the level achieved by sulfenamide acceleration (mixture 1). In the case of NR mixtures with carbon black, the tension at 300% elongation is also improved.

Example 8

Comparison of N-trichloromethylthiohydantoins with Vulcalent E in NR-mixtures filled with Corax N 220 in combination with N, N'-substituted bis- (2,4-diamino-s-triazin-6-yl) -tetrasulfide as accelerator (N).

mixture number 8 9 10 11 12 13 RSS 1, ML (1 + 4) = 70-80 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! CORAX N 220 50 50 50 50 50 50 ZnO RS 5 5 5 5 5 5 stearic acid 2 2 2 2 2 2 Naftolen ZD 3 3 3 3 3 3 Protector G 35 1 1 1 1 1 1 Vulkanox 4010 NA 2.5 2.5 2.5 2.5 2.5 2.5 Vulkanox HS 1.5 1.5 1.5 1.5 1.5 1.5 Vulkacit MOZ 1.43 - - - - - N - 1.5 1.5 1.5 1.5 1.5 Vulkalent E - - 0.8 - - - VZ g - ·· - 0.8 - - VZ h - - - - 0.8 - VZ k - - - - - 0.8 sulfur 1.5 0.8 0.8 0.8 0.8 0.8 ie (170 ° C), min 4,5 2.9 3.8 4.6 4.4 4.0 ie (130 ’c), min 22.5 9.5 14.0 23.5 21.7 21.0 properties of vulcanizate at 170 170C voltage at 300% elongation 10.2 10.6 10.7 11.4 11.4 11.2

Comparison of Vulcalent E (mixture 10) with N-trichloromethylthiohydantoins (mixtures 11-13) shows that these hydantoins lead to an increase in the incubation time and a higher stress value at 300% elongation.

Example 9

Temperature dependence of the effect of substituted N-trichloromethylthiohydantoins in accelerating vulcanization with bis- (2-ethylamino-4-diethylamino-s-triazin-6-yl) disulfide in NR-mixtures filled

CORAX N 220 mixture number 14 15

RSS 1, ML (1 + 4) = 70-80 100 100

CORAX N 220

mixture number 14 15 Dec ZnO RS 5 5 stearic acid 2 2 Naftolen ZD 3 3 Vulkanox 4010 NA 2.5 2.5 Vulkanox HS 1.5 1.5 Protector G 35 1 1 V 143 1.29 1.29 VZ 1 - 0.85 sulfur 1.5 1.5 ie, min: 145 ° C 9.2 18.5 160 ’c 5.2 8.6 170 'C 4.0 5.4 180 ° C 2.8 4.1 vulcanization rate, min: (t 90% - t 10%) 145 ° C 15.9 18.7 160 ’C 4.1 5.5 170 ° C 2,0 3.1 180 ° C 1.3 1.5 vulcanizate properties: stress at 300% elongation, MPa 145 ° C 10.6 12.1 170 ’C 9.5 11.7 Shore-A hardness: 145 C 65 68 170 ’C 63 68

The addition of N-trichloromethylthiohydantoins causes a significant increase in the incubation time at the processing temperatures of the mixtures (< 145%) without substantially reducing the vulcanization time at higher temperatures.

Example 10

Effect of substituted N-trichloromethylthiohydantoins on acceleration with mixtures of bis- (2-ethylamino-4-diethylamino-s-triazin-6-yl) -oligosulfides (M) in NR mixtures filled with CORAX N 220 carbon black and silica mixture number 16 17 18

RSS 1, ML (1 + 4) = 70 - 80 CORAX N 220

100 ALIGN!

100 ALIGN!

100 ALIGN!

mixture number 16 17 18 Ultrasil VP 3 gran. 25 25 25 ZnO RS 5 5 5 stearic acid 2 2 2 Naftolen ZD 3 3 3 Protector G 35 1 1 1 Vulkanox 4010 NA 2.5 2.5 2.5 Vulkanox HS 1.5 1.5 1.5 Vulkacit MOZ 1.43 - - M - 3 3 VZ i - - 0.78 sulfur 1.5 0.8 0.8 ie (170 ° C), min 4.6 3.9 4,5 ie (130 O, min properties of vulcanizate (170 ´ C) 33.3 16.6 32.5 voltage at 300% elongation 3.6 6.0 8.3 In NR-mixtures filled with CORAX 18) extension of the incubation time of the tension note at 300% elongation N 220 and silicic acid additive VZ also shows a reference level (mixture 16) and at the same time an increase compared to mixture 17. Example 11 Effect of substituted N-trichloromethylthiohydantoin filled with CORAX N 220, whose vulcanization is accelerated / Vulkacit MOZ in an NR-mixture mixture V 225 / mixture number 19 Dec 20 May 21 RSS 1, ML (1 + 4, = 70-80) 100 ALIGN! 100 ALIGN! 100 ALIGN! CORAX N 220 50 50 50 ZnO RS 5 5 5 stearic acid 2 2 2 Naftolen ZD 3 3 3 Protector G 35 1 1 1 Vulkanox 4010 NA 2.5 2.5 2.5 Vulkanox HS 1.5 1.5 1.5 Vulkacit MOZ 1.43 0.72 0.72 V 225 - 0.75 0.75 VZ k - - 0.4 sulfur 1.5 1.5 1.5 ^D max - ^D min << ^{170 C C} > ^Nm 8.56 8.19 8.79

mixture number 19 20 21 t (170 'O, min 4,5 4,2 4,8 t (130 ´ C), min 22,5 15,6 20,1

When N, Ν'-substituted bis- (2,4-diamino-s-triazin-6-yl) disulphide is used concomitantly and commercially available conventional sulfenamide accelerators (mixture 20), the addition of VZ to (mixture 21) also results in incubation period.

Example 12

Effect of VZ g when using a combination of N, Ν'-substituted bis- (2,4-diamino-s-triazin-6-yl) -tetrasulfides and Si 69 as accelerator in NR mixtures filled with CORAX N 220 and silicic acid

smšs číslo 22nd 23 24 RSS 1, ML (1 + 4) = 70-80 100 ALIGN! 100 ALIGN! 100 ALIGN! CORAX N 220 25 25 25 Ultrasil VP 3 gran. 25 25 25 Si 69 3.75 3.75 3.75 ZnO RS 5 5 5 stearic acid 2 2 2 Naftolen ZD 3 3 3 Protector G 35 1 1 1 Vulkanox 4010 NA 2.5 2.5 2.5 Vulkanox HS 1.5 1.5 1.5 Vulkacit MOZ 1.43 - - (B) - 1.66 1.66 VZ g - - 0.75 sulfur 1.5 1.5 1.5 ie (170 c), min 4.9 4.2 5.1 ie (130 ° C), min 37.5 25.4 37.0 As can be seen from Example 12, it achieves a carbon black and silicic acid loading increasing the vulcanization time of the presence of Si 69. Example 13 Effect of VZ g in NR mixture using meshed donoru s D and stuffed with CORAX N 220 Irish mixture number 25 26 27 Mar: RSS 1, ML (1 + 4) = 70-80 100 ALIGN! 100 ALIGN! 100 ALIGN! CORAX N 220 50 50 50

mixture number 25 26 27 Mar: ZnO RS 5 5 5 stearic acid 2 2 2 Naftolen ZD 3 3 3 Protector G 35 1 1 1 Vulkanox 4010 NA 2.5 2.5 2.5 Vulkanox HS 1.5 1.5 1.5 Vulkacit MOZ 1.43 - - D - 1.76 1.76 VZ g - - 0.75 sulfur 1.5 - - Sulfasan R - 0.7 0.7 t ^. (170 ’c), min 4,5 3.2 4.6 i.e. (130 ’C), min 22.5 11.5 21.5 Even using bis- (2,4-diamino- extension of time in NR-mixtures containing a sulfur donor together with N, Ν'-substituted s-triazin-6-yl) -tetrasulfides (mixture 27), VZ g adds a significant cure to the level of the reference mixture containing sulfur and sulfene-

amide accelerator (mixture 25).

Example 14

Effect of VZ 1 in combination with N, Ν'-substituted bis- (2,4-diamino-s-triazin-6-yl) -oligosulfide in a BR-mixture filled with CORAX N 330

mixture number 28 29 30 31 Buna CB 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! CORAX N 330 60 60 60 60 ZnO RS 3 3 3 3 stearic acid 2 2 2 2 Naftolen ZD 15 Dec 15 Dec 15 Dec 15 Dec Protector G 35 1 1 1 1 Vulkanox 4010 NA 1.5 1.5 1.5 1.5 D 1.76 1.76 - - V 225 - - 1.5 1.5 VZ 1 - 0.85 - 0.85 sulfur 1.5 1.5 1.5 1.5 ie (165 ° C), min 4.3 5.8 6.8 9.5 properties of vulcanizate at 165 'C voltage at 300% elongation 7.1 9.6 6.0 9.0

Example 14 shows that polybutadiene filled with CORAX N 330 and accelerated by N, N '-substituted bis- (2,4-diamino-s-triazin-6-yl) -di- and tetrasulfides increases the incubation time and simultaneously a substantial increase in the stress value at 300% elongation when N-trichloromethylthio-5-pentamethylenehydantoin is used as an additive.

Example 15

Effect of VZ 1 in combination with N, Ν'-substituted bis- (2,4-diamino-s-triazin-6-yl) -oligosulfides as accelerators in NBR mixtures containing CORAX N 330 as a filler

mixture number 32 33 34 35 Perbunan N 3307 NS 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! CORAX N 330 60 60 60 60 ZnO active 5 5 5 5 stearic acid 1 1 1 1 Mesamoll 10 10 10 10 paraffin solid 1 1 1 1 Vulkanox HS 1.5 1.5 1.5 1.5 D 1.76 1.76 - - V 225 - - 1.5 1.5 VZ 1 - 0.85 - 0.85 sulfur 1,2 1,2 1,2 1,2 D - D. , (170 ’C), Nm max mm 9.23 12.81 8.18 12.40 ie (170 c), min 3.5 4.7 4.8 8.3 Rate of vulcanization t90-110%, min 8.2 2.8 9.4 3.3 properties of vulcanizate at 170 ° C voltage at 300% elongation 14.0 16.9 11.6 15.6

Addition of VZ 1 to NBR mixtures in the presence of N, Ν '-substituted bis- (2,4-diamino-s-triazin-6-yl) -tetra- and disulfides makes it possible to improve the safety of the mixture against incineration while increasing the vulcanization rate. A significant increase in the value of tension at 300% elongation is also achieved, although the initial level is already very high.

Example 16

Effect of VZ i on vulcanization in combination of N, N‘-substituted bis- (2,4-diamino-s-triazin-6-yl) -oligosulfides NR / BR mixtures

mixture number 36 37 38 39 RSS 1, ML (1 + 4) = 70-80 70 70 70 70 Buna CB 30 30 30 30 CORAX N 220 50 50 50 50

mixture number 36 37 38 39 ZnO active 5 5 5 5 stearic acid 2 2 2 2 Naftolen ZD 3 3 3 3 Protector G 35 1 1 1 1 Vulkanox HS 1.5 1.5 1.5 1.5 Vulkanox 4010 NA 2.5 2.5 2.5 2.5 D 1.76 1.76 - - V 143 - - 1.29 1.29 VZ i - 0.78 - 0.78 sulfur 0.8 0.8 0.8 0.8 ie (170 c), min 2.7 4.3 4.1 5.7 t R (130 C), min 6.6 17.2 16.8 32.8

Example 16 shows that even mixtures containing a combination of NR with synthetic rubber can significantly increase the safety against incineration of the mixture using N-trichloromethylthio-5-n-propylhydantoin.

Claims (1)

SUBJECT OF THE INVENTION The vulcanization retarder of rubbers containing double bonds with an effect of increasing the crosslink density for use in systems comprising, as accelerators and / or crosslinkers, the oligosulfide compounds of the general formula (II): represents a hydrogen atom, R represents a hydrogen atom or a benzyl group, each of 2 3 4 R, R and R are C 1 -C 8 alkyl, allyl, cycloalkyl C 274292 B2 C 3 -C 8 optionally substituted with 1 to 3 methyl, 2-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl or R ³ and together represent an alkylene group having 4 to 6 carbon atoms or a group of the general formula - (ch ₂ -chx) ₂ y wherein X is methyl or hydrogen and Y is oxygen or sulfur, and ri is 2 or 4, or mixtures of compounds of formula II wherein (S) _n is a sulfur chain having a mean statistical length corresponds to the meaning of n = 4 and optionally containing additional sulfur donors, characterized in that it consists of a hydantoin of the formula I r5 (D NH —- CO where each of the symbols 5 6 R and R, which are the same or different, are hydrogen, (C1-C6) alkyl, benzyl or phenyl; or R ³ and r ⁶ together represent a closed methylene chain of 4 to 6 carbon atoms, the ring formed optionally being mono- or di-substituted by methyl.