CS201748B1 - Foamed polymere material with lower flammability - Google Patents

Description

(54) Cellular polymeric material with reduced flammability

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cellular polymeric material with reduced flammability, particularly for the production of thick-walled and large-surface parts, respectively.

Low flammability plastics are required for many applications, particularly in the construction, home furnishing, automotive, aerospace and electronics industries. This is achieved by the addition of so-called flame retardants. The effectiveness of flame retardants is increased by the addition of so-called synergistic agents. To achieve adequate flame retardancy, a marked amount of both flame retardants and synergistic impurities must be dosed. This in turn has a negative impact on the mechanical properties of the products and their resistance to aging. In order to improve the mechanical properties, it is then necessary to increase the content of the elastomeric component in the system and subsequently to strengthen the stabilizing system.

The disadvantage of such mixtures is the limited application possibilities, since thick-walled products, about 4 mm thick, cannot be prepared from them without the risk of depressions. Due to the limited flowability of the melt, it is also not possible to prepare large-area products with satisfactory physico-mechanical properties.

The height of the honeycomb is removed by the use of a cellular polymeric material for the production of thick-walled and large-surface parts, respectively, characterized in that it consists of 50 to 85% by weight. % tough polyvinylaromatic masses, 5 to 15 wt. % flame retardant, preferably halogenated organic compound, 3-16 wt. % synergistic additives, preferably antimony trioxide, 0.1 to 1.5 wt. % antioxidant of phenolic type, 0.1 to 3.0 wt. % organotin compounds and / or 0.1 to 3.0 wt. % barium, cadmium, zinc or calcium salts of organic acids or mixtures thereof; % of a light stabilizer of the benzophenone or benztriazole type or of a group of substances referred to as spherically shielded amines, optionally suitable mixtures of said light stabilizers and / or 0.5 to 3.0 wt. % of pigments or dyes with high absorption in the wavelength range 280 to 480 nm, preferably black pigment and 0.05 to 2.0 wt. blowing agents, physical or chemical, with a decomposition point above 160 ° C. ,. The polymeric material may contain 1.0 to 25.0 wt. % chlorinated polyethylene and / or 0.1 to 3.0 wt. epoxidic compounds. A further improvement, in particular color stability, can be achieved by adding 0.1 to 3.0% by weight. a phosphite type stabilizer.

The composition according to the invention can be processed by injection molding or extrusion into lightweight thick-walled or large-surface panels, while maintaining a reduced flammability, favorable aging resistance and, in particular, excellent physico-mechanical properties. The presence of gaseous blowing products in the product results in a sandwich structure and thus properties that allow for a variety of technical applications. Such products can then be used in electronics, for example as cabinets for phonographs and the like, since the resonance properties of the products are comparable with the wood used up to now. It is equally beneficial to use these products in the construction, aerospace and automotive industries, as they have favorable flame retardancy while retaining the design physico-mechanical properties and high aging resistance.

Tough polyvinylaromatic mass is understood to mean polystyrene which contains as a modifying component an unsaturated elastomer and / or terpolymers containing, in addition to the polystyrene and elastomeric components, another component, for example acrylonitrile). Typical representatives of polyvinylaromatic materials are so-called tough polystyrene and graft polymer acrylonitrile-butadiene-styrene (ABS polymer).

By flame retardant is meant an organic compound containing bromine, chlorine, phosphorus or nitrogen, or a combination of these elements. Particularly preferred is the use of halogenated organic compounds such as octabromodiphenyl, nonabromodiphenyl, decabromodiphenyl, decabromodiphenyl oxide, hexabromocyclododecane, tris-dibromopropyl phosphate, tris-bromocresyl phosphate, chlorinated and thickened paraffins and the like. etc. especially with antimony trioxide.

Chlorinated polyethylene is a product obtained by chlorination of low-pressure polyethylene up to a content of 25.0 to 45.0% by weight. chlorine. Since the plasticized composition is subjected to elevated temperatures, it is desirable that the chlorinated polyethylene used be effectively stabilized against elevated temperatures.

As phenolic antioxidants, mono-nuclear, sterically shielded phenols such as 2,6-di-tert-butyl-4-methylphenol, octadecyl-3 (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate, a mixture of phenol alkylation products and the like can be used. or substituted polyhydric phenols such as 2,5-ditercamyl hydroquinone, hydroquinone monobenzyl ether or substituted bisphenols and thiobisphenols such as 2,2'-methylene-bis (4-methyl-6-tert-butylphenol), 2,2'-methylene-bis (4 methyl-6-nonylphenol), 4,4'-butylidene-bis (3-methyl-6-tert-butylphenol), 4,4'-methylene-bis (2-methyl-6-tert-butylphenol), 2,2'-thio bis- (4-methyl-6-tert-butylphenol), 4,4-thio-bis- (3-methyl-6-tert-butylphenol) and the like; and more nuclear phenols such as 1,1,3-tris (2'- methyl-4'-hydroxy-5'-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3 ', 5-di-tert-butyl-4'-hydroxybenzyl) benzene, pentaerythritol tetrakis (3- (3 ', 5'-di-tert-butyl-4-hydroxyphenyl) propionate and the like, singly or in combination.

Suitable organotin compounds are dibutyltin maleate, dioctyltin maleate, di-n-octyl-tin-di (mono-2-ethylhexyl maleate), dioctyltin mercaptide, dibutyltin dilauryl mercaptide, dibutyltin-Scol, octyl-di (octyl) di (octyl) isolate.

Examples of organic acid salts include barium and cadmium salts of lauric acid, a mixture of calcium and zinc salts of stearic acid, barium, cadmium and zinc salts of carpylic acid and the like.

As the light stabilizer of the benzophenone type, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4 (2-ethylhexyloxybenzophenone), 2,2-dihyroxy-4-methoxybenzophenone, 2-hydroxy-4 -n-butyloxybenzophenone, bis (4-ethoxy-2-hydroxybenzophenone) and the like.

Suitable light stabilizers of the benztriazole type are, for example, 2- (2'-hydroxy-5'-methylphenyl) benztriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenztriazole, 2 (2'- hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole and the like.

Examples of suitable light stabilizers from the class of compounds referred to as spherically shielded cyclic amines are bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate or 2,2,6,6-tetramethyl-4-salicylaliminopiperidine-1-oxide and the like. .

The light stabilizers can be used singly or in any combination.

Suitable pigments or dyes absorbing in the region of 280 to 480 nm are various inorganic and organic pigments of black, yellow, green and white color, as well as certain organic dyes and mixtures thereof.

Phosphite type stabilizers are phosphorous acid esters such as tris (nonylphenyl) phosphite, tris (phenylethylphenyl) phosphite, 2,4-dinonylphenyl-di- (4-monononylphenyl) phosphite, distearylpentaerythritol diphosphite and the like.

Suitable epoxide compounds include epoxidized soybean oil, epoxystearic acid butyl ester, epoxystearic acid 2-ethylhexyl ester, phenylglycidyl ether, polycondensation products of epichlorohydrin and bisphenol and the like.

Physical or chemical blowing agents can be used to form the sandwich structure. Physical ones include nitrogen, pentane, CH ₃ Cl, freons and the like. Of the chemical common types with a decomposition temperature above 160 ° C, in particular azodicarbonamide or N, N'-dinitroso-pentamethylene-tetramine.

The flame retardant polymeric material of the present invention has substantially more favorable fire performance characteristics such as flame and heat resistance, oxygen number, flame retardancy, and the like, which have been verified using widely used tests such as UL-94, ASTM D 635, CSN 64 0756 and the Herpol index.

Chlorinated polyethylene, which acts as a flame retardant as well as a synergistic additive, can also be used to reduce flammability. This can reduce the amount of accumulated flame retardants in the mixture, which has a beneficial effect on mechanical properties and aging resistance. In terms of mechanical properties, the presence of chlorinated polyethylene is reflected primarily in higher values of impact and notch toughness and thermal resistance of the material.

The aging resistance of the polymeric material according to the invention is substantially higher. Here, the presence of chlorinated polyethylene has a beneficial effect and the combination of phenolic-type antioxidants with substances referred to as hydrogen halide acceptors is essential. These are the aforementioned types of organotin compounds or said barium, cadmium, zinc or calcium compounds, optionally in combination with epoxide compounds.

Particularly effective said combination of stabilizers is in those cases where the polymer is protected from light exposure by the addition of suitable light stabilizers of the benzophenone or benztriazole type or a compound of the group referred to as sterically shielded cyclic amines or suitable mixtures of said light stabilizers. Where the polymer cannot be protected from light radiation by suitable pigmentation for various reasons, or if the pigment or dye used does not have the necessary absorption in the short-wave region of the light radiation, the use of light stabilizers is necessary.

A further improvement in the resistance to aging, in particular with respect to color changes during aging, was achieved when the use of phenolic antioxidants was combined with the addition of a phosphite-type stabilizer (phosphorous acid esters).

The advantages of using the polymer blend of the invention are demonstrated by the following examples:

Example 1

One hundred mass. parts by weight of polystyrene containing 6% polybutadiene were added, 14.5 wt. parts by weight of decabromodiphenyloxide, 6 wt. parts of antimony trioxide, 0.3 wt. parts of octadecyl-3 (3 ', 5'-di-tert-butyl-4-hydroxyphenyl) -propionate. The mixture was homogenized in a Henschel quick mixer and then plasticized on a screw extruder. 6.3 X X 12.6X126.0 mm beads were injected from the granulate. However, the sprays showed depressions. Thus, this mixture has proven unsuitable for injection of thick-walled products. Also the deterioration of the properties of the material during aging in the veterometer (ČSN 64 0772) was very significant.

Example 2

0.6 wt.% Was added to the composition of Example 1. blowing agents type ADC (azodicarbonamide). The mixture was mixed and plasticized. The bodies prepared in the same manner as in Example 1 had a perfect depression-free surface. The material exhibited the desired flammability reduction, good mechanical properties. However, the aging resistance of the material was again less satisfactory. Example 3

To the composition of Example 2 was added:

0.3 wt. , parts of dibutyltin maleate

0.6 wt. parts of 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenztriazole

0.6 wt. parts of tris-nonylphenyl phosphite

After processing the mixture in the same manner as in Example 2, a test specimen of practically the same properties as in Example 2 was sprayed, but in addition with very good aging resistance. Selected material properties important for applications are given in Table 1.

Example 4

Per 100 wt. parts of ABS polymer containing 13% polybutadiene were added:

14.5 wt. parts of decabromodiphenyloxide

6.0 wt. parts of antimony trioxide 1.0 wt. parts of octadecyl-3 (3 ', 5'-di-tert-butyl-4-hydroxyphenyl) propionate

The mixture was homogenized in a Henschel quick mixer and then plasticized on a screw extruder. 6.3X12.6X126.0 mm beads were ejected from the granulate. However, the sprays showed depressions. Thus, this mixture has proven unsuitable for injection of thick-walled products. Also, the deterioration of the aging properties of the material in the veterometer (CSN 64 0772) was very significant.

Example 5

0.6 wt.% Was added to the composition of the example. blowing agents type ADC (azodicarbonamide). The mixture was mixed and plasticized. The bodies prepared in the same manner as in Example 4 had a perfect depression-free surface. The material exhibited the desired flammability reduction, good mechanical properties. However, the aging resistance of the material was again less satisfactory. Example 6

The following composition was added to the composition of the example:

0.3 wt. parts of barium cadmium stabilizer

0.6 wt. parts of epoxybutyl stearate

0.6 wt. parts of 2 (2'-hydroxy-5'-methylphenyl) benztriazole

0.3 wt. parts of distearylpentaerythrityldiphosphite

After processing the mixture in the same manner as in the previous examples, test specimens having the same properties as in Example 5 were obtained, but in addition with very good aging resistance. Selected material properties important for applications are listed in Table 1.

Table 1

Sample according to 1 ex. number 1 Specific weight [kg. m'- ³ ] Flammability according to UL-94 (vertical test) ! Flexural strength: [M Pa] and Impact toughness [kJ. m * ^{1 2} ] 1 Index increment yellowness Δ IŽ (a) 2 850 V-0 28.6 9.8 34.6 3 850 V-l 27.1 9.7 19.1 5 850 V-0 35.2 12.3 42.7 6 850 V-0 36.3 12.4 20.2 7 850 V-0 36.2 11.9 20.5 8 850 V-0 39.0 14.6 22.7 9 850 V-0 40.1 16.2 24.9 10 850 V-l 27.3 9.5 9.8 11 850 V-0 34.3 12.0 15.4 12 850 V-l 31.2 11.4 21.3 13 850 V-0 30.2 11.3 20.5 14 850 V-0 35.2 12.9 17.2 15 Dec 850 V-0 35.0 12.6 0

The results shown in the table were obtained by extrapolating to the same specific material weight from the values measured in the specific gravity range of 790 to 900 kg / m ³ a) ..... after 32 hours of irradiation with a 400 W Hg lamp through a Pyrex filter.

Examples 7 to 9

The composition of Example 3 was modified so that not 100 parts by weight of tough polystyrene was used as the basis for the composition, but its mixture with chlorinated polyethylene in the following proportions:

in Example 7: 99 wt. parts HPS + 1 wt. parts of CPE in Example 8: 90 wt. parts HPS + 10 wt. parts of CPE in Example 9: 75 wt. parts HPS + 25 wt. CPE parts

The further procedure was the same as in Example 3. An overview of the properties of these prepared materials is given in Table I and demonstrates a further improvement of the properties in the presence of CPE.

Examples 10 to 15

The composition of Example 6 was modified so that the following directions were followed in the recipe:

Example 10: dekabromdifenyloxid oktabromdifenylem was replaced by the same amount as in Example 11 was replaced by hexabromocyclododecane dekabromdifenyloxid in the same amount, in Example 12: Sb ₂ O ₃ was replaced with molybdic acid in the same amount as in Example 13: Sb _{2 O;!} was replaced by Sb ₂ S ₃ in the same amount, in Example 14: 2 (2'-hydroxy-5'-methylphenyl) benztriazole was replaced by the combination of bis (4-ethoxy-2-hydroxybenzophenone) with bis (2,2,6,6-tetramethyl-4). -piperidyl) sebacate 1: 1, in example 15: 2 (2'-hydroxy-5'-methylphenyl) benzothiazole was replaced by 1% black pigment concentrate with an active ingredient content of 60%. All other components of the mixture in Examples 10 to 15, as well as the preparation process, remained the same as in Example 6. An overview of the properties of the materials so prepared is given in Table I.

Claims (3)

OBJECT OF THE INVENTION CLAIMS 1. A expanded flame retardant polymer material comprising 50 to 85 wt. polyvinylaromatic masses, 5 to 15 wt. % flame retardants, preferably halogenated organic compounds, 3 to 6 wt. % synergistic additives, preferably antimony trioxide, 0.1 to 1.5 wt. % antioxidant phenolic type, 0.1 to 3.0 wt. % organotin compounds and / or 0.1 to 3.0 wt. barium, kadeipnaté, zinc or calcium salts of organic acids, or mixtures thereof, from 0.1 to 2.0 ° / ₀ by weight. % of a light stabilizer of the benzophenone or benztriazole type or of a group of substances referred to as spherically shielded amines, optionally suitable mixtures of said light stabilizers and / or 0.5 to 3.0 wt. pigments or dyes with high absorption in the wavelength range 280 to 480 nm, preferably black pigment and 0.05 to 2.0 wt.% parts of the blowing agent of the physical or chemical type, preferably with a decomposition point above 160 ° C. 2. The polymer material of claim 1, wherein the polymeric material comprises from 1.0 to 25.0 wt. % chlorinated polyethylene and / or 0.1 to 3.0 wt. epoxidic compounds. Polymeric material according to Claims 1 and / or 2, characterized in that it also contains 0.1 to 3.0 wt. a phosphite type stabilizer.