CH632775A5 - Flame retardant - Google Patents

Description

The invention relates to a high molecular weight flame retardant agent.

Organophosphorus or organohalogenated compounds have been used as flame retardants for thermoplastic resins, as described, for example, in American patents Nos. 3247134, 3262894,3278464, 3359220, 3368916 and 3372141, English patents Nos. 1015212,1094723 1108064, and the Belgian patent N "709417.

However, when the traditional organophosphorus compounds are added to the thermoplastic resins in an amount sufficient to impart flame retardation properties, there is the disadvantage of a lowering of the softening point and a significant reduction in the heat resistance of thermoplastic resin. On the other hand, traditional flame retardants containing halogens such as bromine or chlorine have poor thermal stability. For example, tetra-bromobisphenol A decomposes at 220 ° C with the release of bromine.

The object of the invention is to provide a flame retardant of high molecular weight, having good compatibility with thermoplastic resins, having an effect delaying the propagation of a flame on a normally flammable thermoplastic resin, without reducing the resistance to heat of this resin.

The invention also aims to provide a composition of thermoplastic resin delaying the propagation of a flame, containing polycondensation products containing phosphorus, and having good thermal stability. .

These objects are achieved by the flame retardant agent according to the invention, which is characterized in that it comprises polycondensation products containing phosphorus, a dicarboxylic acid represented by the following formula I : o

2

»2

GHCOOH

ch2cooh

Wherein Rt, R2 and R3 each represent hydrogen, halogen or an alkyl, cycloalkyl, aryl or aralkyl group with a polyalcohol.

In particular, polycondensation products containing phosphorus, in which one or more of the groups R1 (R2 and R3 of formula I are halogens, preferably bromine, have an excellent flame retardant effect and have stability thermal such that they do not cause the formation of halogen, even at temperatures above 300 ° C.

Dicarboxylic acids of formula I can be prepared by reacting, while heating, a compound represented by the following formula II:

H

50

in which R1; R2 and R3 are defined as above, with itaconic acid.

In general, this reaction can take place at temperatures of 100 to 250 ° C without any catalyst. The reaction is carried out quantitatively, without the formation of side products. As a result, by using the stoichiometric amounts, it is possible to obtain pure dicarboxylic acid, of formula I.

This can usually be confirmed by paper chromatography, thin layer chromatography or liquid chromatography. In accordance with the infrared absorption spectrum, the products obtained can be easily identified as being compounds of formula I, by the disappearance of the P —H bond (wave number 2340) and the double bond (wave number 1630 ), and the formation of the CH2 and CH groups and of the “s P — C bond (wave number approximately 718).

Compounds of formula II can be prepared according to the method described in US Patent No. 3702878 or Japanese published patent No. 17979/75 or similar methods.

3

632775

For example, compounds of formula III:

'-G

in which Rj, R2 and R3 are defined as above, are obtained by reacting 1 mol of a substituted O-phenylphenol compound, of formula IV:

OH

where Rj, R2 and R3 are defined as above, with 1.3 mol of phosphorus trichloride, in the presence of 0.003 mol of zinc chloride, at temperatures of 130 to 200 ° C, for about 20 h. The compound of formula III thus obtained is purified by distillation and hydrolyzed by adding an excess of water, the remaining water then being removed under reduced pressure of about 10 mmHg, so as to form compounds of formula II.

Rls R2 and R3 of formula I are preferably hydrogen, chlorine, bromine, a methyl, tert.-butyl, cyclohexyl group,

phenyl or benzyl. Preferably, Rj and R3 are each hydrogen, chlorine or bromine, and R2 is chlorine or bromine.

Typical examples include 9,10-dihydro-9-oxa-10-phosphorophenanthrene-10-oxide; 6-bromo-9,10-dihydro-9-oxa-10-phosphorophenanthrene-10-oxide; 6,8-dibromo-9,10-dihydro-9-oxa-10-phosphorophenanthrene-10-oxide; 8-tert.-butyl-9,10-dihydro-9-oxa-10-phosphorophenanthrene-10-oxide; 2,6,8-trichloro-9,10-dihydro-9-oxa-l 0-phosphorophenanthrene-10-oxide and 6-phenyl-9,10-dihydro-9-oxa-10-phosphorophenanthrene-10-oxide .

The dicarboxylic acids of formula I can be condensed with alcohols, to form esters, in the same way as other carboxylic acids.

The polyalcohols which can be used in the invention are, for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,10-decanediol, 1,4-dihydroxymethyl-cyclohexane, hydrogenated bisphenol A, ethylene oxide adducts of bisphenol A, products of ethylene oxide addition of tetrabromobisphenol A, of ethylene oxide addition products of tetrabromobisphenol S, 2,2-dibromomethyl-1,3-propanediol, glycerin, trimethylolethane, trimethylol- propane or pentaerythritol.

In the polycondensation reaction, monocarboxylic acids or monoalcohols can be used, if desired, in order to obtain polycondensation products having improved properties of compatibility with thermoplastic resins. Condensation products leaving hydroxyl or carboxyl groups at the ends of the molecular chain exhibit lower compatibility with resins in general.

Monocarboxylic acids or monoalcohols can act to improve compatibility, by reaction with such end groups. Mention is made, by way of example, of acetic acid, propionic acid, benzoic acid, naphthoic acid, adducts of palmitic acid and methacrylic acid of the compounds of formula II; methanol, ethanol, propanol, butanol, ethylene glycol monomethyl ether, ethylene glycol mono-butyl ether, ethylene glycol monophenyl ether, ethylene oxide adducts of tribromophenol, 2,2,2 -tribromomethyl-ethanol, palmityl alcohol and stearyl alcohol.

The polycondensation reaction can be carried out in the presence or not of catalysts. The catalysts which can be used are, for example, acidic catalysts such as sulfuric acid, paratoluenesulfonic acid or phosphoric acid, or metal compounds such as zinc acetate, lead acetate, germanium oxide, antimony trioxide, sodium alcoholates or potassium phenylphosphate.

The polycondensation products can also be prepared by carrying out condensation with dealcoholization between the polyalcohols and the dicarboxylic acids of formula I and, if desired, a monocarboxylic acid, which have been previously esterified with lower volatile alcohols.

Condensation with dehydration or dealcoholization can be carried out at temperatures of 150 to 290 ° C. When dialcohols are used as polyalcohols, linear polycondensation products are obtained. On the other hand, the use of polyalcohols with three or more valencies leads to the formation of polycondensation products with branched chains.

The molecular weight of the polycondensation products is an important factor for the purpose sought by the invention, since it has a great influence on the softening point and on the compatibility with thermoplastic resins.

An average molecular weight can be adjusted by the degree of polycondensation progression and by a stoichiometric ratio between dicarboxylic acid with phosphorus content, monocarboxylic acid, polyalcohol and monoalcohol.

When the molecular weight decreases, the compatibility with the thermoplastic resins improves, but the hot resistance of the resins tends to decrease.

The molecular weight of the condensation products according to the invention is between 1000 and 20,000, preferably between 2000 and 13,000, the range in which satisfactory compatibility, with minimum reduction in hot resistance, can be obtained for various types of thermoplastic resins. Compatibility can vary according to the class of Rj, R2 and / or R3 of formula I, and the type of polyalcohols, monocarboxylic acids and / or monoalcohols which can be modified appropriately, in order to prepare polycondensation products having good compatibility with each resin.

The polycondensation products can also be prepared by carrying out the polycondensation reaction with polyalcohols, simultaneously with the reaction for forming the compounds of formula I, by reaction of the compounds of formula II with itaconic acid.

Polycondensation products, which usually contain phosphorus in an amount of 3.5 to 8.5% by weight, have a high softening point and good compatibility with various thermoplastic resins, which makes it possible to obtain a resin composition with flame retardant effect, without reducing its heat resistance. Examples of thermoplastic resins include polystyrenes, acrylonitrile / styrene copolymers, polycarbonates, polyterephthalate resins (e.g. polyethylene terephthalate, polybutylene terephthalate and polyarylene terephthalate), ABS resins, polyphenylene oxide resins , polymethacrylate (e.g. polymethylmethacrylate) resins and polyvinyl chloride.

A flame retardant resin composition is obtained by mixing the phosphorus-containing polycondensation product with the thermoplastic resin, so as to have a phosphorus content of 0.15 to 2.5% by weight, relative to the resin. This phosphorus content corresponds to the addition of 2 to 30 parts of polycondensation product per 100 parts by weight of thermoplastic resin.

The softening point is determined by the capillary tube method.

5

10

15

20

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40

45

50

55

60

65

632775

Example I. 432 g (2 mol) are introduced into a 2000 ml capacity four-tube flask equipped with a thermometer, a gas supply tube, an agitator and a reflux condenser. ) of 9,10-dihydro-9-oxa-10-phosphorophenanthrene-10-oxide (hereinafter referred to as HC A), 260 g (2 mol) of itaconic acid and 1300 g of dimethyl sulfoxide. While slowly sending a stream of nitrogen gas through the supply tube, the flask is heated until the reflux of dimethyl sulfoxide takes place slowly. The reaction is carried out at 190 ° C for approximately 2 h.

After the reaction mixture has cooled, white crystals are deposited, which are then filtered and washed with 700 ml of dioxane. After drying, about 620 g of white crystals are obtained. Melting point (mp): 203 ° C Acid number: 325 (calculated 323.7)

Saponification index: 488 (calculated 485.5)

Calculated elementary analysis: C59.0 H 4.3%

Found: C60.2% H 4.5%

The above shows that the final product is identical to the compound of formula I, where Rlf R2 and R3 each represent hydrogen.

Example 1-2:

In a balloon with three tubes, of 1000 ml of capacity, equipped with a thermometer, an agitator and a rectifier of the type with packed column, of 3 cm in diameter and 20 cm of filling height, one loads 588 g (1.7 mol) of the compound obtained in Example 1, and 210 g of ethylene glycol. When the flask is heated, the polycondensation reaction takes place and the water coming from the top of the rectifier is separated by distillation.

While slowly removing the water, the temperature of the contents of the flask is brought to 200 ° C. and this temperature is maintained for 3 h.

Then 0.2 g of zinc acetate and 0.1 g of germanium oxide are added. The rectifier is then removed and a distillation orifice fitted with a cooling trap is connected to it. While slowly separating the ethylene glycol by distillation, the interior of the flask is maintained under reduced pressure of 1 mmHg. The reaction is carried out at 230 ° C for 2 h.

The reaction products are poured into a stainless steel tank and cooled until solidification.

A glassy, colorless and transparent solid is thus obtained.

Phosphorus content: 8.2% by weight

Softening point: around 60 ° C

Approximate molecular weight: 4,500

(in accordance with the determination of a terminal group).

The linear polycondensates obtained above exhibit good compatibility with acrylonitrile / styrene copolymers, polymethacrylate resins, polyterephthalate resins, polyvinyl chloride resins and ABS resins.

10 parts by weight of the above-mentioned polycondensates are then added to 100 parts by weight, respectively, of bisphenol A / terephthalic acid (PAT) and polyvinyl chloride (PVC) polycondensate, and mixed in a Brabender type mill, corresponding temperature of the respective resins. Samples for the combustion test, 3.2 mm thick, 12.2 mm wide and 152.4 mm long, are obtained by subjecting the compounds to compression molding. The flame retardant degree is determined by measuring the combustion time of a sample in accordance with the Sanko Kaihatsu Laboratories Inc. standard.

Subject 94.

The two PAT and PVC samples are expressed in degrees V-0, following the combustion test.

Example 2:

864 g (4 mol) are loaded into a four-tube balloon, 2000 ml capacity, equipped with a thermometer, a gas supply tube, an agitator and a water outlet of HCA, 520 g (4 mol) of itaconic acid and 520 g (4 x 1.25 mol) of neopentyleglycol. The flask is heated while slowly sending nitrogen gas through the supply tube. When the temperature of the products contained in the flask reaches 120 ° C, these products melt and water begins to form.

The temperature is then raised slowly, while driving the agitator, the temperature being maintained at 200 ° C. for 1 h. The water outlet is connected to a vacuum distillation orifice, equipped with a cooling trap, the interior of the flask being maintained under reduced pressure of 18 mm Hg. This pressure is maintained for 15 h to separate by distillation l and neopentylglycol. The reaction is then continued under reduced pressure of 1 mm Hg at 220 ° C for an additional 2 h.

The reaction products are poured into a stainless steel tank and cooled until solidification.

A light yellow transparent glassy solid is thus obtained.

Phosphorus content: 7.2%

Softening point: 96 ° C

Approximate molecular weight: 3800

The linear polycondensates obtained above exhibit good compatibility with polystyrene, polycarbonates, polyphenylene oxides and polyvinyl chloride.

The aforementioned polycondensates are then saponified and decomposed with a methanolic solution of potassium hydroxide, then acidified with hydrochloric acid.

After evaporation of the methanol, a precipitate forms which is then recrystallized from dimethyl sulfoxide, with simultaneous dehydration. The product thus obtained is identical, according to the melting point and the liquid phase chromatography, to the compound of formula I obtained in Example 1.

The above shows that the polycondensation reaction can be carried out simultaneously with the formation of the compounds of formula I, by reaction of the compounds of formula II with itaconic acid.

.40 The combustion test and the determination of the flame propagation speed are then carried out in the same manner as in Example 1-2.

45

Resins

Amounts of polycondensates added *

Propagation speed

50

Polycarbonate (PC)

8

V-2

PAT

10

V-0

Polyphenylene oxide (PPO)

7

V-0

55

PVC

10

V-0

* Parts per 100 parts by weight of resins.

Example 3:

60 One charges, in the same flask with four tubes as in example 2,1,180 g (4 mol) of 6-bromo-9,10-dihydro-9-oxa-10-phosphorophenanthrene-10-oxide (mp 179 ° C, hereinafter referred to as 6-bromo-HCA), 520 g (4 mol) of itaconic acid and 520 g (4 x 1.25 mol) of neopentylglycol, and a clear yellow transparent 65 glassy solid is obtained .

Phosphorus content: 6.2%

Softening point: 119 ° C Approximate molecular weight: 4200

5

632,775

The linear polycondensates thus obtained exhibit good compatibility with polystyrenes, polycarbonates, polyterephthalate resins, polyphenylene oxides and polyvinyl chloride.

Example 4:

A transparent, light yellow, glassy solid is obtained in the same way as in Example 2, except that 1.176 g (3 mol) of 6,8-dibromo-HCA monohydrate (mp 210 ° C.) is used, 390 g (3 mol) of itaconic acid and 390 g (3 x 1.25 mol) of neopentylglycol.

Phosphorus content: 5.3%

Softening point: 126 ° C

Approximate molecular weight: 5,500

The linear polycondensates thus obtained exhibit good compatibility with polystyrenes, polyterephthalate resins, polycarbonates, polyphenylene oxides, polymethacrylate resins and polyvinyl chloride.

Example 5:

1.294 g (3 x 1.1 mol) 6,8-dibromo-HCA monohydrate, 390 g (3 mol) itaconic acid, 21.6 g (3 x 0.1 mol) acrylic acid, 312 g (3 mol) of neopentylglycol and 75 g (3 x 0.4 mol) of ethylene glycol are loaded into the same flask as in Example 2. The flask is heated, while slowly sending a stream of nitrogen gas.

When the temperature of the products contained in the flask reaches 120 ° C, these products melt and water begins to form.

The temperature is then raised slowly, while driving the stirrer, and the reaction is carried out at 200 ° C for 2 h. 0.02 g of sodium methylate is then added. The water outlet is connected to a vacuum distillation orifice, equipped with a refrigeration trap, and the flask is maintained under reduced pressure of 18 mmHg. This pressure is maintained for 2 h to separate, by distillation, water, ethylene glycol and neopentyl glycol. The reaction is continued under reduced pressure of 1 mmHg at 240 ° C for an additional 2 h. The reaction products are poured into a stainless steel tank and cooled until solidification.

A slightly yellowish glassy solid is thus obtained.

Phosphorus content: 5.5%

Softening point: 121 ° C

Approximate molecular weight: 5400

(according to a viscosity method).

The linear polycondensates above obtained exhibit good compatibility with polystyrenes, polycarbonates, polyphenylene oxides, polymethacrylate resins, polyterephthalate resins, ABS resins and polyvinyl chloride.

In addition, the aforementioned polycondensate is saponified and decomposed by a methanolic solution of lithium hydroxide, then acidified with hydrochloric acid. Liquid chromatography confirms the presence of the compound of formula I, in which Rj and R2 are bromine, the acrylic acid adduct of the compound of formula II, in which Rj and R2 are bromine, neopentylglycol and ethylene glycol.

Example 6:

The following is loaded into the same flask as in Example 2,816 g (3 mol) of 8-tert.-butyl-HCA, 558 g (3 mol) of diethylitaconate, 629 g (3 x 0.8 mol) of 2, 2-dibromoethyl-1,3-propanediol, 28 g (3 x 0.07 mol) of trimethylolpropane and 0.1 g of lead acetate. The balloon is heated while slowly sending nitrogen gas. When the temperature of the products contained in the flask reaches 120 ° C., stirring is carried out and the ethanol is separated by distillation, while raising the temperature. After reaching 150 ° C, the products are kept at this temperature for 1 h. The water outlet is connected to a vacuum distillation orifice, and the reaction is carried out under reduced pressure of 18 mmHg for 6 h.

The reaction products are poured into a stainless steel tank and cooled until solidification.

The yellow glassy product thus obtained is a slightly branched polycondensate.

Phosphorus content: 5.0%

Softening point: 115 ° C

This polycondensate has good compatibility with polystyrene, polycarbonates and polyphenylene oxides.

Furthermore, the combustion test and the determination of the flame propagation speed are carried out in the same manner as in Example 1-2.

Resins

Amounts of polycondensates added

Propagation speed

Polystyrene (PS)

15

V-2

PC

7

V-0

PPO

5

V-0

Example 7:

Charged, in the same flask as in Example 2,958.5 g (3 mol) of 2,6,8-trichloro-HCA, 390 g (3 mol) of itaconic acid and 390 g (3 x 1.25 mol) of neopentylglycol. A light yellow glassy product is obtained in the same manner as in Example 2, except that the polycondensation is finally carried out at 250 ° C under reduced pressure of 1 mm Hg for 3 h.

Phosphorus content: 6.0%

Softening point: 112 ° C Approximate molecular weight: 12,000 (according to a determination of the terminal group). The linear polycondensate obtained above has good compatibility with polystyrene, polycarbonates, polyphenylene oxides, polyterephthalate resins, polymethacrylate resins, ABS resins, acrylonitrile / styrene copolymers and polyvinyl chloride.

Example 8:

Using the polycondensates of Examples 3 to 5, and 7, the combustion test and the determination of the flame propagation delay are carried out in the same manner as in Example 1-2.

Table 1

not. Examples

Xn-

Resins x.

3

4

5

7

ps

10v-2

10 v-1

10 v-1

10v-2

as1

10 v-1

10 v-0

10 v-10

15v-1

pc

8

v-0

4

v-0

4

v-0

5

v-1

pat

8

v-0

4

v-0

4 v-0

5

v-0

ppo

6

v-0

3

v-0

3

v-0

5

v-0

pmm2

15v-1

10 v-1

10 v-1

10v-2

5

10

15

20

25

30

35

40

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Table 1 (continued)

Ny. Examples

\not*

3

4

5

7

X resins.

PVC

7

V-0

5

V-0

5

V-0

10 V-0

ABS3

15 V-1

15 V-0

15 V-0

20 V-0

styrene (AS), polycarbonates (PC) and ABS resins (ABS), various flame retardants are added, varying the quantities so that the average combustion time has substantially the same value.

Resins

Average combustion time (s)

PS

20

AS

20

PC

10

ABS "

20

The figures in each upper row indicate the quantities of polycondensates added (parts by weight), and the symbols in each lower row indicate the speed of flame propagation.

1 Acrylonitrile / styrene copolymer.

2 Polymethylmethacrylate.

3 ABS resin.

Example 9:

To each of the polystyrenes (PS), acrylonitrile /

As flame retardants, polycondensates from Examples 3 to 7 are used and, for comparison, tris- (2,3-dibromopropyl) -phosphate (TBP), and a composite flame retardant of antimony trioxide and tetrabromobisphenol A (Sb-TBA).

The flame retardant resin compositions thus obtained are subjected to tests relating to transparency, the lowering of the thermal deformation temperature and the presence of halogenated acids, at the molding temperatures (200-280 ° C.). .

bleau 2

N. Retar Resins

daters n. flame

PS

(76 ° C)

AS (82 ° C)

PC

(135 ° C)

ABS (82 ° C)

Example 3

15.0 16 ° C Transparent None

16.0 17 ° C Transparent None

4.0 8 ° C Transparent None

16.0 17 ° C Transparent None

Example 4

8.0 9 ° C Transparent None

7.5 6.5 ° C Transparent None

1.8 3.5 ° C Transparent None

8.0 9 ° C Transparent None

Example 5

7.5 7 ° C Transparent None

8.0 8 ° C Transparent None

1.8 3.5 ° C Transparent None

8.5 9 ° C

Semi-transparent None

Example 6

9.0 10 ° C Transparent Low

9.0 8.5 ° C Transparent Low

2.0 5 ° C Transparent Low

10.0 10.5 ° C Transparent Low

Example 7

12.0 12 ° C Transparent None

11.0 10 ° C Transparent None

3.5 6 ° C Transparent None

12.0 13 ° C Semi-transparent None

TBP comparative test

7.0 21 ° C Transparent Very pronounced

7.5 20 ° C Transparent Very pronounced

2.5 18 ° C Transparent Very pronounced

9.0 25 ° C Semi-transparent Very pronounced

Comparative test Sb-TBA

10.5 19 ° C Opaque Low

12.0 20 ° C Opaque Low

6.0 23 ° C Medium Opaque

10.5 17 ° C Medium Opaque

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The parentheses indicate the temperatures of thermal deformation of the resins.

1st line: Quantity added of flame retardant, in parts per 100 parts by weight of resin.

2nd line: Reduced temperature, compared to the thermal deformation temperature.

3rd line: Transparency of resin compositions, observed with the naked eye.

Last line: Indication of the importance of the presence of halogen acid, at the appropriate molding temperature for each resin composition.

Estimates are shown as follows:

None: none no halogenated acid.

Low: sensitive to pH indicator paper after a long time.

Medium: sensitive to pH indicator paper after a short time.

Very pronounced: sensitive to pH indicator paper after a short time, with a pronounced odor of halogenated acid.

R

Claims (9)

632775 i CLAIMS 1. Agent delaying the propagation of a flame, of high molecular weight, characterized in that it comprises poly-condensation products containing phosphorus, of a dicarboxylic acid c! H2cooh in which R15 R2 and R3 each represent a hydrogen, halogen, or an alkyl, cycloalkyl, aryl or aralkyl group, with a polyalcohol. 2. Agent according to claim 1, characterized in that one or more of Ri, R2 and R3 consist of a halogen. 3. Agent according to claim 1, characterized in that R! and R2 consist of bromine and R3 is hydrogen. 4. A resin composition with an effect delaying the propagation of a flame, characterized in that it comprises 100 parts by weight of a thermoplastic resin, and 2 to 30 parts by weight of polycondensation products containing phosphorus, of a dicarboxylic acid represented by the formula I of claim 1. 5. Composition according to claim 4, characterized in that one or more of Rls R2 and R3 consist of a halogen. 6. Composition according to claim 4, characterized in that Rj and R2 consist of bromine and R3 is hydrogen. 7. Composition according to claim 4, characterized in that said thermoplastic resin is chosen from the group comprising polystyrene, acrylonitrile / styrene copolymers, poly-carbonates, polyterephthalate resins, polyphenylene oxides, polyurethane resins. polymethacrylate, polyvinyl chloride and ABS resins. 8. A method of manufacturing the agent according to claim 1, characterized in that a polycondensation product is obtained by reacting the dicarboxylic acid of formula I with a polyhydric alcohol and a monocarboxylic acid. 9. A method of manufacturing the agent according to claim 1, characterized in that a polycondensation product is obtained by reacting the dicarboxylic acid of formula I with a polyhydric alcohol and a monoalcohol.