DE2800019A1 - N-poly:bromo- or chloro-benzyl saccharin cpds. - which are used as flame retardants in polymer moulding compsns. and have high thermal stability - Google Patents

Abstract

N-Benzyl-saccharins of formula (I) are new. In (I), X1-5 are each Br, Cl, H, Me or 1 or 2 of these substits. in a saccharin-N-CH2-gp. but >=3 of the subtits. are Br or Cl. (I) are used esp. as flame retardants in polymers, specif. moulding compsns. They have good compatability with most polymers and are completely stable at processing temps. (e.g. above 200 degrees C). They are effective in small amts., so that there is little effect on the physical properties of the finished prod. Zn borate, Na antimonite and esp. Sb2O3 have a synergistic effect.

Description

N-halobenzyl-saccharins, their manufacture and use

The invention relates to new saccharins of the general formula I benzylated on the nitrogen wherein the substituents X1, X2, X3, X4 and X5 are identical or different from the group consisting of bromine, chlorine, hydrogen, CH3, or one or two of the substituents represent the remainder mean, with the proviso that three or more of the substituents Xi to X5 are bromine or chlorine.

The invention also relates to a method for production the saccharin derivatives of the formula I, which it is characterized in that alkali salts the saccharin in the presence of inert solution or reaction media at elevated temperature, unpressurized or under the pressure of the solvent media used, with nuclear halogenated Benzyl halides, xylylene dihalides and / or tri- (halomethyl) benzenes is implemented as well as the use of these substances as flame retardants for Plastics and molding compounds made from plastics with contents of the substances of the formula I for the production of flame-retardant plastics.

According to DT-OS 26 36 599, 3-oxo-1.2-benzisothiazoline-1.1-dioxide, known as "saccharin", with acid chlorides saccharin-N-acyl -Derivative that are effective as medicinal products.

The saccharin derivatives of the present invention differ of those of the listed DT-OS due to their high halogen content, as well as due to that they are N-bent, yl derivatives of saccharin, prepared from benzyl halides - instead Acid chlorides - represent. They are also flame retardants at the same time Contain halogen, nitrogen and sulfur. Such flame retardants are useful little known.

The compounds of general formula I are by reaction of Saccharin alkali metal compounds in which the alkali metal cation sodium, potassium, Ammonium, or others, with halogenated halomethylbenzenes in the core obtained in good purity. The halomethyl benzenes are those which are halogenated in the core Mono-halomethyl-di-halomethyl and optionally also the trihalomethyl benzenes in question, where the halomethyl group is the chloromethyl or bromomethyl group, optionally the iodomethyl group - is understood.

Halomethylbenzenes halogenated in the core can in particular are used: pentachlorobenzyl chloride, pentabromobenzyl chloride, pentabromobenzyl bromide, Tetrabromo monochlorobenzyl chloride, 1-methyl-4-chloromethyl-2.3.5.6-tetrachlorobenzene and its positional isomers, including 1-methyl-4-bromomethyl-2.3.5.6-tetrachlorobenzene Isomers, 1-methyl-4-bromomethyl-2.3.5.6-tetrbromobenzene, 1.4-bis (chloromethyl) -2.3.5.6-tetrachlorobenzene and the isomeric 1,3- or 1,2-bis (chloromethyl) tetrachlorobenzenes, 1,4-bis (bromomethyl ) -2.3.5.6-tetrachlorobenzene, as well as the 1.3- or 1.2-bis (bromomebhyl) -tetrachlorobenzenes, 1.4-bis (bromomethyl) -2.3.5.6-tetrabromobenzene and isomers, 1.4-bis (chloromethyl) -2.3.5.6-tetrabromobenzene, and its 1,3-bis (chloromethyl) or 1,2-bis (chloromethyl) isomers, 1.4 or 1.3- or 1.2-bis (chloromethyl) -tribromomonochlorobenzenes as well as from the tris (halomethyl) -halogenobenzenes especially the 1 .3.5-tris (chlorine (or bromo) methyl) -tribromobenzenes.

The saccharine-alkali metal compounds are preferably prepared and particularly advantageously in situ by putting the saccharin in suitable solution or diluents with an amount of an alkali hydroxide equivalent to the saccharin, dissolved in water.

At the same time, the use of ready-made, solid saccharine salts is also possible possible.

As a suitable solvent or diluent for carrying out the Reaction are particularly advantageous those that are at least partially a solution the reaction components cause. Reaction media that are favorable are those which Have boiling points around 1000C or up to about 1200C, since with these without pressure vessels can be worked. However, pressure vessels can be used with equal success use lower-boiling reaction media such as tetrahydrofuran.

Particularly suitable solvent and reaction media are: Dioxane, Äty englycol monomethyl ether (methylglycol), ethylene glycol monoethyl ether, xethylene glycol monobutyl ether, Ethylene glycol, methyl ethyl ketone, methyl isobutyl ketone, etc.

As a reaction temperature, depending on the reactivity, the as Starting material used kerilalogenated halomethylbenzenes, the range between 50 and 2000C, preferably between 80 and 1500C, are possible.

The resection times are predominantly short and depend on the reaction temperature between one and 8 hours, mostly only 2 to 5 hours.

The reaction components are preferably used in equimolar proportions subject to each other to the reaction, although also a small excess, if necessary up to about 5%, one or the other component is possible.

When performing the procedure, the order of addition is the Reaction components indifferent. Saccharin can be in pure form or as made from technical Process-derived less pure substance can be used. Generally will Saccharin in a stirred vessel equipped with a reflux condenser at room temperature dissolved in a solvent and stirred in the equivalent amount of aqueous Alkali solution converted into the salt. What is halogenated in the core is then incorporated into the solution Entered halomethylbenzene with stirring and the reaction mixture rapidly Boiling temperature heated. The target products formed fall in the course of the reaction time usually already in the heat from the reaction mixtures. Your isolation can by hurling, Sucking off, or other simple measures take place, whereupon the as a by-product; formed alkali metal halides the solid mixture is washed out with water and that it is suitable for use as a flame retardant already enough pure and colorless N-substituted saccharins at elevated temperature dries with or without vacuum application. r the substances according to the invention of general formula I are thermally very stable can dry temperatures without disadvantage of 100 ° C and far above can be used.

The substances of the formula I can be used as effective flame retardants in plastics of any chemical structure can be incorporated.

The excellent thermal stability is particularly advantageous when in use of the new substances according to the invention as flame retardants for plastics that e require processing temperatures above 200 ° C, such as poly (tetramethylene terephthalate) or poly (ethylene terephthalate). The new substances according to the invention are, however also advantageous flame retardants for e.g. polyolefins. The following are considered to be polyolefins: High or low density polyethylene, polypropylene, polybutene, polymethylpentene or mixtures of the polyolefins with one another. Furthermore copolymers such as ethylene-propylene-diene copolymers, abbreviated to EPDM in the following text.

The substances of the general formula I according to the invention meet to a large extent the demands that are to be made of a flame retardant, why Another object of the invention their use as flame retardants for Plastic molding compounds from which fire-protected plastics are made should is.

The saccharin derivatives of the formula I can easily be converted into plastics incorporate, they are well compatible with most polymers and when required Processing temperatures completely stable.

Another advantage of the substances according to the invention is that they are proportionate small amounts are sufficient to achieve good fire protection effects, which results in only small amounts Changes in the mechanical-physical properties of the finished products.

The substances of the general formula I are preferred in the polymers together with synergistic compounds such as zinc borate, sodium antimonite, however, used particularly advantageously with antimony trioxide.

In general, the flame retardants according to the invention are used 2 to 20% by weight, preferably 4 to 15% by weight, based on the finished molding composition of the Kinststoff an Antimony trioxide is used 0.5 to 8 wt .-%, with special Advantage 1 to 5% by weight.

The incorporation of the flame retardant additives can be carried out in a customary manner Mixing on heated rolls, mixing extrusion, or some other suitable measure take place. In addition, the necessary auxiliary additives can be added to the plastics such as lubricants, stabilizers, pigments or other common additives are incorporated will.

Example 1 -Pantabromobenzyl-saccharin: In a 2 liter reaction vessel equipped with a stirrer, reflux condenser and internal thermometer, 3.3 g (0.4 mol) of technical grade saccharin in 800 ml of methyl glycol (boiling point) were added at room temperature.

122-126 ° C), then a solution of 16 g (0.4 mol) of solid sodium hydroxide in 16 ml of water added and saccharin sodium salt nter self-heating to 50 ° C educated. In the warm solution of the sodium salt were 226.3 g (0.4 mol) of pentabromobenzyl bromide suspended as a solid substance with stirring and heated. Was at boiling point a clear solution, from which the reaction product soon becomes a fine, light precipitate failed. After a further 2 hours, the suspension of the product was cooled, filtered off with suction, washed with water and dried at 100 ° C.

Yield 251.4 g (94.1% of theory).

Recrystallized 4us xylene (1 g ae 30 ml) had a melting point of 273-275 ° C (glassy from 2630C).

Weight loss according to TGA with heating rate 80C / min. In air: 1% at 316 ° C; 5% at 3300C; 10% at 3360C; 20% at 339 ° C.

Elemental analysis: C14H6Br5NO3S (667.82) calculated: C 25.18%; H 0.90%; Br 59.83%; N 2.10%; O 7.19%; S 4.80%.

found: C 25.28%; H 0.84%; Br 59.90%; N 2.13%; O 7.13%; S 4.73%.

eispiella n similarly was made from saccharin and pentachlorobenzyl chloride obtained the N-pentachlorobenzyl saccharin. Yield 74%.

chmp. after recrystallization from 1,2-dichloroethane (1 g per 20 ml) 263-266 ° C.

Elemental analysis: C14H6Cl5NO3S (445.53) calc .: C 37.74%; H 1.36%; Cl 39.79%; N 3.14%; 0 10.77%; S 7.20%.

Found: C 37.61%; H 1.29%; Cl 39.88%; N 3.22%; O 10.61%; S 7.14%.

Example 2 N-Pentahalobenzyl-saccharin In 100 ml of methyl glycol 91.6 g (0.5 mol) of techn. Saccharin and 20 g (0.5 mol) of sodium hydroxide reacted in 20 g of water to form the saccharin sodium salt. This was brought to reaction for 1 hour at reflux temperature with 26.1 g (0.5 mol) of pentahalogenobenzyl chloride, which had been prepared by side-chain chlorination of pentabromotoluene (DT-OS 25 34 210), according to the procedure of Example.

Work-up according to Example 1 yielded 29 g (86.8% of theory) Saccharin derivative of m.p. 268-272 ° C.

Elemental analysis: C14H6Br4.5Cl0.5NO3S (645.58) calc .: C 26.04%; H 0.94%; Br 55.70%; Cl 2.75%; N 2.17%; O 7.43%; S 4.97%.

found : 0 25.93%; H 0.87%; Br 55.94%; Cl 2.78%; N 2.04%; 0 7.29%; S 4.77 %.

Example 3 N- (3-methyl-2.4.5.6-tetrachlorobenzyl) saccharin: In a 250 ml three-necked round-bottomed flask, according to Example 1, 18.35 g (0.1 mol) of technical grade saccharine were formed with sodium saccharine. 27.85 g (0.1 mol) of 1-chloroethyl-3-methyl-2.4.5.6-tetrachlorobenzene were stirred into the solution at 60 ° C. and the reaction mixture was reacted at 12,000 for 3.5 hours while stirring.

After suctioning off, washing and drying as before, 35.6 g (83.6 % d. Th.) Saccharide derivative of melting point 219-221 ° C (recrystallized from 1 b 15 ml each Dichloroethane).

Weight loss according to TGA with a heating rate of 8 ° C / min. in air: 1% at 295 ° C; 5% at 33600; 10 hours at 357 ° C; 20% at 375 ° C.

Elemental analysis: C15H9Cl4NO3S (425.12) calc .: C 42.38%; H 2.13%; Cl 33.36%; N 3.29%; 0 11.29%; S '7,54eo.

Found: C 42.46%; H 2.04%; Cl 33.18%; N 3.42%; 0 11.38%; S 7.42%.

Example 4 Preparation of N- (4-methyl-2.3.5.6-tetrabromobenzyl) saccharin: Following the procedure of the preceding examples, 120 ml of methyl glycol, 18.35 g (0.1 mol) of saccharin, 5.6 g (0.1 mol) of potassium hydroxide in 6 ml of water and 50.1 g (0.1 mol) of 1 were added -Bromomethyl-4-methyl-2.3.5.6-tetrabromobenzene reacted.

After work-up and recrystallization, 55.6 g (92.2% of theory) Saccharin derivative with a melting point of 276-278 ° C was obtained.

Weight loss according to TGA with a heating rate of 800 / min. in air: 1% at 215 ° C; 5% at 263 ° C; 10% at 336 ° C; 20 * at 358 ° C.

Elemental analysis: C15H9Br4NO3S (602.95) 1cal .: C 29.88%; H 1.50%; Br 53.01%; N 2.32%; 0 7.96%; s 5.32%.

Found: C 29.87%; H 1.50%; Br 53.20%; N 2.43%; 0 8.11%; S 5.26%.

Example. 5 Preparation of p-2.3.5.6-tetrabromoxylylene-bis- [2.3-dihydro-1.2-benzoisothiazolon- (3) -yl- (2) -dioxide- (1)]: Be, room temperature, 1.6 g (0.5 mol) of saccharin become Na-.

Salt formed.

In the warm solution of the sodium salt, 144.9 g (0.25 mol) 1.4-bis (bromomethyl) tetrabromobenzene by entering the solid substance with stirring suspended. After reaching the boiling temperature, a fine precipitate soon fell the end. After 2 hours the reaction was complete.

After working up as before, the yield was 176.4 g (90% of theory). Melting point 329-3350C with formation of a melt after the onset of dark discoloration from 290 ° C.

Weight loss according to TGA with a heating rate of 8 ° C / min. in air: 1% at 287 ° C; 5% at 335 ° C; 10% at 351 ° C; 20% at 356 ° C.

Elemental analysis: C22H12Br4N2O6S2 (784.11) calc .: C 33.70%; H 1.54%; Br 40.76%; N 3.57%; O 12.24%; S 8.18% Found: C 33.83%; H 1.57%; Br 40.80%; N 3.44%; O 12.09%; S 8.11% Example 6 p-Tribrommonochlorxylylene-bis- [2.3-dihydro-1.2-benzoisothiazolone- (3) -yl- (2) -dioxide- (1)] In the apparatus of Example 1, 150 ml of methyl glycol, 18.32 g (0.1 mol) of saccharin, 4.0 g (0.1 mol) of sodium hydroxide in 4 ml of water and 24.5 g (# 0.05 mol) 1,4-bis (chloromethyl) tribromomonochlorobenzene was allowed to react for 2 hours at reflux temperature and then the cooled mixture was worked up as described. 31.2 g (79.5 * of theory) of the above-mentioned saccharin derivative with a melting point of 323-332 ° C. (dark discoloration from 2800 ° C.) were obtained.

Elemental analysis: C22H12B3ClN2O6S2 (739.66) calc .: C 35.72%; G 1.64%; Br 32.41%; Cl 4.79%; N 3.79%; O 12.98%; S 8.67%.

Found: C 35.85%; H 1.79%; Br 32.70%; Cl 4.70%; N 3.63%; O 12.64%; S. 8.42%.

Example 7 Preparation of p-Tetrachlorxylylene-bis- [2.3-dihydro-1.2-benzoisothiazolon- (3) -yl- (2) -dioxide- (1)]: In 600 ml of methyl glycol, 146.55 g (0.8 mol) of technical grade saccharin, 32 g (0.8 mol) of sodium hydroxide in 35 ml of water and 125.2 g (0.4 mol) of 1,4-bis (chloromethyl) -2.3.5.6-tetrachlorobenzene reacted in 3.5 hours at reflux temperature.

After working up as in Example 1, we obtained 199.7 g (82.3% d.Th.) of the mentioned colorless saccharin derivative of mp.

34-347 ° C (recrystallized 10 g of 1.3 1 methylglycol).

Weight loss according to TGA in air with a heating rate of 80C / min .: 1% at 316 ° C; 5% at 3770C; 10 * at 387 ° C; 20% at 394 ° C.

Elemental analysis: C22H12Cl4N2O6S2 (606.29) calc .: C 43.58%; H 2.00 %; Cl 23.39%; N 4.62%; 0 15.83%; S 10.58% found: C 43.88 *; H 2.09%; Cl. 23.40 %; N 4.59%; 0 15.98%; s 10.43%.

Example 8 Use as a flame retardant in plastics: The table 1 gives the results of measurements of the flame retardant effect on plastic samples with contents of the substances according to the invention again.

We determined the Limited Oxygen Index (LOI in Vol.% 02) ASTM D 2863-70. The LOI values mean the concentration of oxygen, expressed in% by volume of an oxygen-nitrogen mixture obtained under the conditions of the test method barely sustains the combustion of the plastic sample.

The greater the oxygen index or the greater the difference between the LOI-Wet of the plastic provided with flame retardants and the LOI-value of the Plastic of the comparison samples free of flame retardants1 is all the better is the flame retardant effect of the plastic samples.

The incorporation of the flame retardants according to the invention (= FS agents) took place with the polyolefins on a roller tunnel. The milled heads obtained were pressed into the test strips.

In the case of poly (tetramethylene terephthalate), the compounds were on a Mixing extruder produced and then flowing from the granules obtained on a Injection molding machine manufactured the test specimens.

The following table clearly shows the flame retardant effect of the substances according to the invention in plastics, compared to the bulk polymers.

T able 1 PA = polyethylene; PP = polypropylene; EPDM = ethylane-propylene-diene copolymer; PTMT = poly (tetramethylene terephthalate). The specified additional amounts mean percent by weight in the finished compound. Artificial substance from FS means:% by weight LOI substance example saccharin derivative Sb2O3 vol.% O2 PÄ * 0 0 18.2 PÄ 1 9 3.5 26.4 PÄ 4 9 3.5 22.2 PÄ 5 9 3.5 26.5 PP - 0 0 17.3 PP 1 9 3.5 24.6 PP 4 9 3.5 22.9 PP 5 9 3.5 23.9 EPDM * 0 0 17.4 EPDM 19 3.5 25.0 EPDM 1 10 4.0 25.5 EPDM 4 9 3.5 23.3 EPDM 5 9 3.5 24.7 PTMT * 0 0 22.6 PTMT 4 10 4 26.7 * for comparison, without flame retardants

Claims (4)

P at; entansprü che 1 N-Benzyl-saccharine of the general formula I. wherein the substituents xl, X2, r35, X4 and X5 are identical or different from the group consisting of bromine, chlorine, hydrogen, CH3, or ei or two of the substituents represent the remainder mean, with the proviso that three or more of the substituents X1 to X5 are bromine or chlorine. 2. Process for the preparation of the saccharin derivatives of the formula I, characterized in that alkali salts of saccharin in the presence of inert solution or reaction media at elevated temperature, without pressure or under autogenous pressure solution media used, with nucleus halogenated benzyl halides, xylylene dihalides or / and tri- (halomethyl) -benzenes is implemented. 3. Use of compounds of formula I as flame retardants by Incorporation into polymers. 4. Molding compositions with contents of compounds of the formula 1.