DE2350393A1 - COMPOUNDS USED AS MODIFICATORS FOR HYDROCARBON POLYMERS AND METHODS FOR THEIR PRODUCTION - Google Patents

Description

As Hodifi indicators for carbon enwaes he st off usable polymeric Verbindu n s and methods of their H za e rstβΐΐτιημ;.

The invention "relates to mixed anhydrides as novel compounds ■ of organic sulfonyl azides and their production, and their use as modifiers for hydrocarbon polymers.

It is known that hydrocarbon polymers including cis-1,4-polyisoprene, polybutadiene and styrene-butadiene rubber, in particular, however, polypropylene and polyisobutylene can be modified by treating them with a honosulfonyl azide of the formula RSOpN where R is an organic radical represents, heated. M-Carboxyi-benzenesulfonyl azide can be used as a modifier (i.e. 3 ~ azidosulfonylbenzoic acid). The range of azide can be from 0.001 to 20% by weight, calculated on the polymer to be modified. The ßulfonylazid can either be in a solid state with the help of a Usual device for rubber processing or in the form

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a solution are mixed with the polymer. The modification process is carried out by heating the resulting mixture to a temperature at which the sulfonyl azide decomposes; this temperature can 90 "to JOO be ⁰ C. Thus, for example offset polypropylene with 2% of polymer weight of 3-Pyridinsulfonylazid and the mixture heated for 2 hours at 150 ° C. The aim of the known Modifikat ions traversing ens is the production of products having improved Colorability, emulsifiability and adhesion to other materials.

It has now been found that carbon dioxide polymers can be used also in a different perspective (e.g. with regard to their greenness) can improve if one uses a hish anhydride as suifonylazide an organic sulfonylazide with at least one carboxyl group is used.

According to the invention is added, therefore, the to be modified Kohlenwasserstoffpolymex "0.001 to 20% of its weight of a mixed anhydride of an organic Sulfonylazides init added at least one carboxyl group, followed by hydrolyzing the anhydride and the mixture heated to a temperature above 50 ⁰ C, to be used as Tlodifikator Anhydrides of sulfonyl azides with at least one carboxyl group are novel compounds and the invention includes both this class of compounds and a process for their preparation. The term "anhydrides" here also includes the thioanhydrides.

The anhydride is mixed with the polymer at a temperature which is below the decomposition temperature for the anhydride. Preferably, the temperature during the premixing of the anhydride with the polymer under 1JO ⁰ C and in particular below 70 ° C.

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In the following, the addition of the anhydride to the poly mer with "Stage A", the hydrolysis of the anhydride with "Stage B" and the heating of the mixture with "Stage G".

The sulfonyl azides according to the invention which can be used as modifiers and have at least one carboxyl group can have more than one azidosulfonyl group, but anhydrides with a single azidosulfonyl group are preferred. In the general formula (N ^ S0 ₂ ) _m -A ~ [C (0) -XC (0) fi] _{nt to} which the mixed anhydrides according to the invention correspond, A stands for an organic group, preferably an aromatic radical and in particular a phenylene group, R for a - in particular saturated - hydrocarbon radical, which can optionally be substituted, and X for sulfur or - preferably - oxygen, while m and η are integers from 1 to 3 »preferably 1.

The mixed anhydrides can be derived from aliphatic Sulphonyl azides with at least one carboxyl group, such as 4-azidosulphonylbutyric acid. Preferred modifiers are however, anhydrides of aromatic azidosulfonyl carboxyl compounds of the above general formula, in which A is an aromatic radical such as phenylene, tolylene, naphthalene or p-phenoxymethylene radical. The mixed anhydrides can be derived, for example, from 3-azidosulfonylbenzoic acid, 3-azidosulphonyl-6-chlorobenzoic acid, 4-azidosul-r fonylphenoxyacetic acid, 4-azidosulfonylbenzene-1,2-dicarboxylic acid, 5-azidosulfonylnaphthalene-i-carboxylic acid, 3-azidosulfonyl-4- neopentylbenzoic acid and 3-azidosulfonyl-4-ethylbenzoic acid. Good results are achieved with Kisch anhydrides of 3-azidosulfonylbenzoic acid. The radical R is preferred an alkyl radical having at least 5 carbon atoms, in particular with at least 10 carbon atoms. Good results are obtained with mixed anhydrides of stearic acid, where R is a

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Is heptadecyl radical.

The novel mixed anhydrides can be produced in the usual way. For example, you can use a Azidosulfonylcarboxylic acid with an acyl halide, in particular an acyl chloride out of round, although in the presence of an acceptor for hydrogen halide, such as pyridine or triethylamine; the implementation takes place e.g. according to the following scheme:

-C (O) OH + C ₁₇ H ₅₅ -C (O) Cl pyridine

ether

One of the following manufacturing processes can also be used apply: conversion of an (alkali) salt of an azidosulfonylcarboxylic acid with an acyl halide; Implementation of a halide of an azidosulfonylcarboxylic acid with an (alkali) salt of a Fatty acid or with a fatty acid in the presence of an acceptor for hydrogen halide.

For example, anhydrides of the above general formula in which X is sulfur can be prepared by reacting of a halide of an azidosulfonyl carboxylic acid with a salt such as a lead salt, a thiol acid.

Conditions which favor the formation of anhydride are as follows: The ratio of the reaction participants should be between the stoichiometric ratio and a two to three-fold excess of one of the two components; the reaction temperature should be between -5 and 1JO ⁰ C and

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are preferably between 25 and 100 ° C; very cheap is an anhydrous reaction medium with e.g. toluene, xylene, diethyl ether or carbon disulfide as solvents.

When they are used to modify hydrocarbon polymers, the mixed anhydrides are preferably present in a solution which contains 0.001 to 20% by weight (calculated on the polymer) of anhydride. The amount in which the anhydride is used is preferably 0.0i to 5 %, in particular 0.05 to 0.8 % of the polymer weight. The preferred amount range is especially true when that is too. hydrocarbon modifying polymer is a diene polymer. The concentration of the anhydride in the solution can be 1 to 90% by weight and in particular 20 to 60% by weight. Suitable solvents for such solutions include those mentioned above as being useful for the preparation of the anhydrides. In the use of the mixed anhydrides according to the invention, particularly suitable solvents are aliphatic hydrocarbons, such as isopentane, η-hexane, isooctane, heavy gasoline and lubricating oil fractions, especially when it is a matter of the modification of diene polymers in aliphatic hydrocarbons. In this case, the anhydride can also simply be dissolved in the solution of the diene polymer itself, in which it dissolves very well.

When using the mixed anhydrides as modifiers For hydrocarbons, stage A of the process - the Adding the anhydride to the polymer - preferably thereby carried out by simply mixing solutions of the polymer and the anhydride. You can also use the polymer iin. melted Mix the state with the anhydride or its solution, provided that the temperature is not so high that a noticeable The azide decomposes or reacts. Such tempera-

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doors are, generally speaking, less than 130 ⁰ C and in particular below 7O ⁰ O. If the polymer is in the form of a yarn or a fabric, then this can either if the anhydride is a liquid, with this itself or otherwise treated with a solution of the anhydride are moistened so that only the polymer surface comes into contact with the anhydride. It is preferable to work at the lowest possible temperatures, for example at room temperature.

After the hydrocarbon polymer has been mixed or brought into contact with the anhydride, the anhydride is hydrolyzed (step B). The hydrolysis can be caused by the moisture present in the mixture of dissolved polymer and anhydride. During the reaction, which takes place at a higher temperature, a carboxylic acid is released and an organic azidosulphonylcarboxylic acid is formed which satisfies the formula (11-, SO ₂ ) _{I 11} -A- (C (O) XH) _n , where A, X, m and η have the above meanings. The temperature during the hydrolysis usually above 55 ° ι especially above 85 ⁰ C. When a mixture of dissolved polymer and anhydride is used, it is advantageous to combine the removal of the solvent with the hydrolysis by treating the mixture with water vapor (steam stripping). Textile goods and yarns which have been impregnated with the anhydride can also be subjected to a steam treatment to carry out the hydrolysis of the anhydride, for example at 105 ° C., provided that the polymer has sufficient dimensional stability at this temperature.

After the hydrolysis, the temperature is the - still wet in general - polymer to about 50 to 70 ⁰ C, in particular 75 to 250 ° C increased (Step C). The azidosulfonyl group then reacts with the hydrocarbon polymer

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under releases of nitrogen. The reaction between the azidosulfonyl group and the available double bond of a (diene) polymer takes place even at a relatively low temperature. At temperatures below 200 ° C., preferably between 135 and 160 ° C., the reaction with a diene polymer is often complete within 15 minutes and possibly even after 0.5 to 10 minutes. The reaction with virtually saturated polymers such as polypropylene, however, far more slowly and lasts for example at 115 ° G 2 days at 150 ⁰ C for 5 hours, and even at 160 ° C over 15 minutes. If it appears appropriate, stage C can be combined with hydrolysis stage B.

The hydrocarbon polymers obtained with the aid of the invention Mixed anhydrides can be modified, can be saturated or unsaturated, crystalline or amorphous, linear or be branched. Examples of suitable starting polymers are polyethylene, polypropylene, copolymers of Ethylene and propylene, polystyrene and polyisobutene.

The invention is of particular importance for polymers of conjugated dienes such as polybutadiene, cis-1,4-polyisoprene and styrene-butadiene random copolymers. Preferably the anhydride is added to a "cement", i.e. a solution of the polymer in an apolar solvent. Quality Results are obtained when modifying isoprene rubbers with a lithium hydrocarbyl or a Ziegler initiator are established and LVN values (limiting viscosity numbers), measured in toluene at 30 ° C, between 2 and 8 dl / g.

The use of the modifiers according to the invention is of particular advantage with conjugated dienes, especially when the polymer solution in question is mixed with the solution of the anhydride is mixed. Above all then is that

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The amount of energy required for mixing is significantly less than when mixing the polymer with the carboxysulfonyl azide compound in the molten state and, moreover, the mixing can be carried out at a lower temperature. On this and also on the fact that the polymer is subjected to only a low shear stress, if at all it is due to the fact that there is practically no polymer degradation is to be feared.

It has been shown that vulcanizable sulfur-containing Mixtures based on a conjugated diene polymer modified according to the invention are essential improved mechanical properties ("basic stability") own. The term "vulcanizable mixture" is used here for mixtures comprising all of the constituents have which are required or desired for vulcanization; such mixtures are therefore ready to be vulcanized. The term "sulfur-containing mixture" refers to mixtures which, calculated on the polymer, at least 0.5 % By weight of free sulfur or a free sulfur producing Vulcanization accelerators included. The mixtures in question preferably also contain one Oxide and / or salt of a divalent metal (e.g. zinc oxide, Lead oxide, zinc stearate, lead stearate or combinations of these oxides with stearic acid). If necessary, you can also other additives, in particular reinforcing fillers such as euss or silica, may also be present.

Vulcanizable mixtures with reinforcing materials or fillers have the best mechanical properties if the latter and the other additives mentioned are added when process stage G, ie the heat treatment at up to 50 ^° C. and above, has ended; they are then combined with the diene polymer formed at this stage

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mixes, which is preferably done at a temperature below. In certain. In some cases, however, it is advantageous if the reinforcement filler is already present during stage A and therefore also during stages B and C. In this In this case, care must be taken that the sulfur must not be mixed with the modified diene polymer before stage C has been completed, otherwise premature vulcanization would occur. Mixing is preferred carried out at a temperature below 100 ° C. As a rule, the accelerator is added together with the sulfur. Oxides and / or salts of divalent metals are also used mixed with the modified diene polymer after stage C has been completed. If so the levels A, B and Q has been performed in the presence of a reinforcing filler and when the azide has been applied in an amount slightly greater than that needed when the reinforcement filler is added after stage C is complete becomes, - you get vulcanizable compounds that are still have very good green strength,

\ of a processing oil / if necessary, a small amountV (e.g. 1 to IO

Use parts by weight ( 100 parts by weight of diene polymer to be modified) together with the reinforcement filler in stage A. Stage A can also be carried out in the presence of other additives, such as antioxidants, agents to prevent buildup, pigments and non-reinforcing fillers, provided that these additives are not too violently involved during stage A and / or B or C react with the azide or its decomposition product. If extending oils, which are usually incorporated in relatively large amounts, are to be used, they are generally only added after the end of stage 6.

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example 1

To a solution of 3-azidosulfonylbenzoic acid and 1.1 Equivalents of pyridine (calculated on the acid) in dry diethyl ether became 1.1 equivalents of stearoyl chloride at room temperature (calculated on the acid) was added, working under an absolutely dry nitrogen atmosphere. After stirring for 1 1/2 hours at tree temperature, the pyridine HGl salt formed, again in the absence of moisture, filtered off.

The filtrate was taken under reduced pressure in a nitrogen atmosphere evaporated to remove the ether and the oil pyridine. A white solid remained which, according to its infrared spectrum, was an essentially pure Kisch anhydride of 3-azidosulfonylbenzoic acid and stearic acid. (Any traces of unreacted acid that may be present can be removed by taking up the substance in pentane or hexane and filtering off the insoluble acid), The infrared spectrum of the anhydride was completely identical with the assumed structure (no OH absorption, strong

-1

Azido absprption at 2119 cm and strong C = 0 absorption at

1820 and 1742 cm " ¹ ). The mixed anhydride melted at 60 to

62 °. C. Analysis: 60.85 calculated: 60.20 found:

H Ii 7.90 8.5 8.0 8.0

To further demonstrate the structure, the anhydride was treated with water at tree temperature, which again resulted in 3-azidosulfonylbenzoic acid forms what has been proven by the following measures:

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a) the melting point (122 to 125 ° 0 with decomposition) *

Id) the melting point with authentic acidity (122 to 125 ° with decomposition) and

c) the infrared spectrum of the hydrolysis product, which was identical to that of pure 3-azidosulfonylbenzoic acid (OH absorption at 2800-3300 cm "' ¹ , O = 0 absorption at

1-1 N

, 'i 1665 cm. and azido absorption at 2125 cm).

The anhydride was soluble in pentane, hexane, benzene, amylenes (Isopentenes), diethyl ether and chloroform. The acid on the other hand was insoluble "in.saturated and unsaturated Hydrocarbons. .

Example 2

In a manner analogous to the above, the reaction of acetyl chloride with 3-azidosulfonylbenzoic acid gave the mixed anhydride of the latter with acetic acid.

The white pesticide did not dissolve in saturated and unsaturated hydrocarbons and melted at 65-68 ° C. The IR spectrum showed no OH absorption, but carbon

be: -1

—1 nylabsorptiones at 1780 and 1715 cm and one azidoabsorp

tion at 2100 cm "

Example 3 '

(a) To demonstrate the advantages of using the inventive Mixed anhydrides obtained in rubber production were carried out as follows:

A 7% strength by weight solution of

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Polyisoprene with an intrinsic viscosity of 7.0 dl / g is used in amylenes. The amyleneh consisted mainly of a mixture of isopentene, isopentane and n-pentane and contained about 2 wt.% Isoprene: Various amounts (see table) of a ^ O wt added in amylenes at 40 ⁰ C, the mixture followed by a further 1/2 hour at 40 ° was stirred. After the expulsion of the solvent within 1/2 hour by stripping with steam at 100 ⁰ C the wet rubber was 20 h under vacuum at 40 ° C dried. The dry rubber was then ^{held at 150 °} C. for a further 5 minutes.

(b) The modified polyisoprene rubbers obtained as above were used to prepare vulcanizable mixtures on a Schwab ent han facility at 65 ° C at a Processing time of 18 min; the components were:

polymer 100 Weight Parts HAF carbon black 50 Il ZnO 5 Il Stearic acid 3 Il polymeric trimethyldihydroquinoline 1 Il N-1,3-dimethylbutyl-R'-phenyl-p- phenylendi amine 1 η aromatic processing oil 4th Il sulfur 2 , 25 It N-Cyclohexyl-2-benzothiazole sulfenamide O , 9 Il

The mixtures were then kept for 5 minutes in a mold at 80 ⁰ C, after which the tensile strength and the elongation at break were determined at Haumtemperatur. The results are shown in Table I.

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TABEL

Example no. Anhydride, j e 0 Vulcanizable mixture Elongation at break
in % LVN of the inodif. I. '100 parts by weight,
Polyisoprene Tensile strength
speed in
kN / m ² Rubber
in dl / g _ ^ O • 0.40 I. co 0.50 co ' 360 a) comparison 157 6.8 -Oil 1052 - * 1) 1070 987 6.0 he" 2) 3190 5.8

CaJ CD CO

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Example 4

To 100 1 of an 18% strength by weight solution of polyisoprene (prepared with sec-butyllithium as initiator, LVN 6.5 dl / g) in amylenes, 155% of anhydride of 3-azidosulfonylbenzoic acid and stearic acid were added as a 3% solution in Amylenes added (corresponds to 0.4% by weight, calculated on polyisoprene). After stirring for one hour, the solvent was ^{driven off with steam (100 °} C., 1/2 h). A portion of the wet rubber crumb was fed into a FOIIMCO extruder. The temperature of the front section was 120 ⁰ C, that of the end section 15O ⁰ C (like all extruders, the I'OIHICO extruder also contains one or more kneading screws.

The housing in which they rotate has a number of slots that make it easier for water and solvents to be drawn off. The dried rubber is expelled through the nozzle). The resulting dry rubber was then used as the starting material for the production of a vulcanizable mixture in a Troester facility (test 4) at 65 ^° C. (18 minutes); the composition corresponded to that of Example 3

Another portion of the moist crumbs was initially held at 40 ° C. in vacuo for 12 hours and then at 85 ° C. for a further 1 hour. He was also processed into a vulcanizable mixture on a Troester device (test 5)

For comparison, the test was carried out with a mixture in which the polymer is not modified with the mixed anhydride had been (experiment b).

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TABSL-LE II

■ Ρ-
O
cc Attempt no. LVN of the modified
Rubber, dl / g .5.9 Vulcanizable mixture
Tensile strength elongation at break
in kN / m2 in% 1130 I. OD
«Α • • ■ 6.1 1200 VJl 7/1 ' 4) with anhydride 5.7 3090 840 I. in 5) with anhydride 1630 b) without anhydride 245

CD

tr ro

cn ο

cn

CD CD

Claims (17)

Claims i * J mixed anhydrides of organic sulfonyl azides of the general formula (N ₃ SO ₂ ) _m -A- £ c (O) -XC (O) Rj _n , where A is an organic group, R is a hydrocarbon radical and X is an oxygen or sulfur atom and m and η are integers from 1 to 3. 2. Compounds according to claim 1, characterized in that in the formula A for an aromatic Group stands. 3. Compounds according to claim 2, characterized in that in the formula A is a phenylene group stands. 4. Compounds according to claim 3, characterized in that in the formula R optionally represents substituted saturated hydrocarbon radical. 5. Compounds according to claim 4, characterized in that R stands for .ein a hydrocarbon radical with at least 5, in particular at least 10, carbon atoms. 6. Hiεchanhydrid of 3-azidosulfonylbenzoic acid according to Claims 1 to 5. 7. Process for the preparation of the compounds according to Claim 1 to 6, characterized in that an azidosulfonylcarboxylic acid or its salt, optionally in -Z- 409817 / 111b BATH ORIGINAL ■. . 1A-43 69U. Presence of an acceptor for hydrogen halide, reacts with a carboxylic acid halide. 8. The method according to claim 7, characterized in that 3-azidosulfonylbenzoic acid is reacted with Stearyl chloride. - * 9. Use of the mixed anhydrides according to claims 1-5 for modifying hydrocarbon polymers, characterized in that one of the mixed anhydrides with at least one carboxyl group is added to a hydrocarbon polymer from 0.001 to 20% by weight, calculated on the polymer, whereupon the anhydride is added hydrolyzed and heats the Gemiach to a temperature of more than 50 ⁰ C. 10. Use of the mixed anhydrides according to claim 9, characterized in that the addition at a temperature below 130 ° C, especially below 70 ⁰ C. 11. Use of the mixed anhydrides according to claim 9 or 10, characterized in that the anhydride is used in solution. 12. Use of the mixed anhydrides according to claim 11, characterized in that the concentration of anhydride in the solution is 1 to "90, in particular 20 to 60 wt -% by.. 13. Use of the mixed anhydrides in any of claims 9 to 12, characterized denotes ge _t that is used in accordance with the anhydride in an amount of 0.01 to 5%, in particular from 0.05 to 0.8% of the polymer weight. - 3 409817/11 16 xüxm gas 1A-43 690 14. Use of the mixed anhydrides according to one of claims 9 to 13 »characterized in that the Hydrocarbon polymer used in solution. 15. Use of the Kisch anhydrides according to one of the claims 9 to 14, characterized in that the hydrolysis is carried out by steam treatment (steam stripping) of the mixture caused while driving off the solvent. 16. Use of the mixed anhydrides according to one of the claims 9 to 15 »characterized in that the mixture after hydrolysis of the anhydride to a temperature of 75 to 250? in particular heated from 135 to 160 ° C. 17. Use of the mixed anhydrides according to the claims 9 to 16, characterized in that as Hydrocarbon polymer the polymer of a conjugated diene, in particular an isoprene rubber with an intrinsic viscosity value between 2 and 8 are used. 409817/1 1 1 p