IE914267A1

IE914267A1 - Composition, in particular for floor covering, based on¹polyphosphazene

Info

Publication number: IE914267A1
Application number: IE426791A
Authority: IE
Original assignee: Atochem
Priority date: 1990-12-14
Filing date: 1991-12-09
Publication date: 1992-06-17
Also published as: KR920012305A; HU913939D0; FI915861A0; AU8975991A; EP0490731A1; FR2670496A1; NO914896L; NO914896D0; FI915861A; CS383391A3; JPH04293965A; CA2057628A1; PT99798A; CN1062359A; IL100221A0; JPH06104774B2

Abstract

Compositions capable of being employed especially in the field of floor coverings. These compositions comprise a polyphosphazene as binder. The coverings manufactured from these compositions are particularly suitable in the field of aeronautics.

Description

The invention relates to compositions intended in particular for the preparation of floor coverings, consisting of a nonhalogenated material, and more particularly floor coverings based on polyphosphazene, the said floor coverings being very particularly intended for applications in the aeronautics sector.

Most commonly used floor coverings are based on compositions containing a halogenated polymer and more precisely polyvinyl chloride (PVC). These compositions are suitable in a large number of applications, but the ever more stringent demands in the aeronautics sector render the use of halogenated polymers increasingly problematical.

According to the present invention, there is provided a composition which can be used in the production of a floor covering usable in the aeronautics sector, which composition contains a polyphosphazene as binder.

The invention provides in particular such compositions containing a polyphosphazene of high molecular weight and still more particularly a polyphosphazene capable of being crosslinked or vulcanised.

The compositions according to the invention may also contain fillers, in particular fillers capable of improving the fire resistance of the composition and of the coatings which are derived therefrom, a crosslinking or vulcanising agent or system and, optionally, additives such as protection agents, plasticisers and pigments. - 2 The polyphosphazene used in the compositions according to the invention may be a polymer containing a plurality of units of formula I OR 5 I p = N 4- (I) OR in which each of the symbols R, which may be identical or different, may represent an organic radical containing up to 12 carbon atoms, and more particularly an aryl radical R3 optionally substituted by a halogen atom, by an alkyl radical having from 1 to 12 carbon atoms or by an alkoxy radical having from 1 to 6 carbon atoms, or an alkenylaryl radical R3.

The aryl radical R^ is advantageously a phenyl, pethylphenyl, p-butylphenyl, p-methoxyphenyl or chlorophenyl radical and the alkenylaryl radical R2 is advantageously the o-allylphenyl radical.

In general, preference is given to the polymers containing a majority of aryl substituents R3 and a low proportion, for example less than 15%, of alkenylphenyl substituents R2.

Preferred polymers are those which have a molecular mass by weight of more than 10,000 and preferably of 100,000 to 2,000,000, without this value being able to be regarded as a limit. - 3 The preparation of polyphosphazenes has been widely described in the literature and does not itself constitute a subject of the invention. Purely by way of information, it will be stated that the polyphosphazenes which have the formula given above are generally obtained by substitution, in particular by means of an alkali metal arylate (corresponding to the meaning of R), of polydichlorophosphazenes, which may be prepared in various ways and in particular by polymerisation of hexachlorocyclotriphosphazene (Allcock process described, for example, in US Patent 3,370,020) or by polycondensation of N-(dichlorophosphoryl)trichlorophosphazene (De Jaeger process described, for example, in US Patent 4,377,558), the contents of the two abovementioned patents having to be regarded as forming part of the present description.

When the polyphosphazene used is capable of being crosslinked or vulcanised, which represents a preferred form of the present invention, and in particular is a polymer containing allylphenyl substituents, the composition may contain a vulcanising agent or system consisting of sulphur, optionally in combination with one or more activators or accelerators or, and preferably, a free-radical initiator.

Amongst these initiators, those which will be mentioned most particularly are the peroxides, such as, for example, dibenzoyl peroxide, 2,5-dimethyl-2,5-di(tIE 914267 - 4 butylperoxy) hexane, 1,1-d i-t-butylperoxy-3,3,5trimethylcyclohexane, dicumyl peroxide or bis(tbutylperoxy)diisopropylbenzene, or the peresters, such as, for example, t-butyl perbenzoate.

Preferably the amount of vulcanising or crosslinking agent or system used does not exceed 10 parts by weight per 100 parts of polyphosphazene, this amount most often being between 0.5 and 5 parts per 100.

The compositions according to the invention 10 advantageously contain reinforcing fillers and in particular inorganic fillers which also improve the fire resistance.

Amongst the latter, the following will be mentioned in particular: aluminas, magnesium hydroxide or magnesium carbonate. Amongst the aluminas, alumina trihydrates are preferred.

Amongst the latter, precipitated aluminas, which are of small particle size, for example less than 2 pm, and do not carry a coating (stearic acid for example), are preferred. On the other hand, coupling agents can advantageously be combined with the fillers, or fillers can be used which have been pretreated with such agents, which may be of the silane or titanate type containing organic functional groups. The silanes may, in particular, comprise vinylsilanes, mercaptosilanes or aminosilanes.

A mixture of fillers may be used, it being possible - 5 for the mixture to comprise only the abovementioned fillers or to comprise these fillers as well as other fillers not having a particular fire-retardant effect. Thus, precipitated silica can be used with the aim of improving some mechanical properties, such as the tear strength.

In general, the compositions may contain up to 300 parts by weight of filler per 100 parts of polyphosphazene, at least 50% by weight of the filler being chosen from the abovementioned aluminas, hydroxide and carbonate.

The compositions may also contain up to 5 parts (per 100 parts of polyphosphazene) of an antioxidant additive which may, for example, be chosen from phenol derivatives. Preferably, the amount of this additive does not exceed 2.5 parts.

The compositions may also contain one or more light stabilisers, such as titanium dioxide, optionally in combination with a benzophenone derivative.

In general, the amount of light stabiliser does not exceed 5 parts per 100 parts of polyphosphazene.

Preferably it is of the order of 0.5 to 2.5 parts.

The compositions may also contain up to 25 parts, preferably up to 15 parts (per 100 parts of polyphosphazene), of a plasticiser which may be chosen, for example, from phosphates, polyphosphates and phosphonates.

Amongst these compounds, the following can be mentioned in particular: tricresyl phosphate, triphenyl - 6 phosphate, cresyl diphenyl phosphate, diphenyl isodecyl phosphate and 2-ethylhexyl biphenyl phosphate.

The compositions may also contain conventional pigments and dyes, in a proportion of 0 to 5 parts per 100 parts of polyphosphazene.

The compositions according to the invention may be prepared by mixing their constituents. Advantageously, the preparation is carried out on a roll mill, for example a 2roll mill, which operates by friction and the nip of which enables a flattened mass which has a thickness which may be between 1 and 5 mm, to be obtained, the flattened mass being homogenised by reintroduction into the mill in the lengthwise direction, that is to say perpendicularly to the axis of the rolls. This malaxating and reintroduction operation is advantageously repeated several times, for example 4 to 10 times.

The initial introduction of the constituents is advantageously carried out in the following sequence; polyphosphazene/protection agents, pigment, plasticiser, silica/fire-retardant fillers/peroxide, optionally diluted with a small amount of filler.

In general, the temperature for the mixing operation is of the order of 20 to 80’C, it being possible to obtain and maintain this temperature by cooling the mill, for example by circulation of water.

After carrying out the above operations, it is - Ί advantageous to leave the flattened mass to stand, for example for 24 hours, and then to proceed to a final run in the mill, controlled so as to give a sheet of desired thickness, with the friction between the rolls suppressed.

The compositions may be vulcanised or crosslinked at a temperature of generally between 120 and 220°C, in a mould which has a geometry corresponding to the section desired for the covering sheets. Moulding generally takes place under a pressure which can be between 107 and 3 χ 107 Pa.

The compositions according to the invention are particularly suitable for the production of floor coverings of the aeronautics type, the coverings meeting the recommendations in this sector.

This field of use is however given by way of illustration and not to limit the scope of the present invention. The floor coverings themselves also form an aspect of the invention. Similarly, it must be understood that the concept of a floor covering is merely an application example and that the invention extends to all other types of covering or methods of application of the said covering.

The following Examples, in which the parts are by weight, further illustrate the invention.

EXAMPLE 1 The following are introduced successively into a - 8 water-cooled two-roll mill which has a friction ratio of 1.33: - 100 parts of polyphosphazene of formula I with a molecular mass (by weight - light scattering) of 1,200,000: 90% of the symbols R representing a phenyl radical and 10% an o-allylphenyl radical, - 110 parts of alumina trihydrate with an average particle size of 1.5 to 2 μτα, - 30 parts of precipitated silica with an average particle size of 0.02 μτα, and - 2 parts of dicumyl peroxide.

The temperature of the mixture being maintained between 50 and 70°C and the nip between the rolls being adjusted to 1.5-2.5 mm, the flattened mass formed is removed with a doctor blade at the discharge from the rolls and is reintroduced into the mill in the lengthwise direction, this operation being repeated 6 times.

After the flattened mass has been left to stand for hours, the nip between the cylinders is reduced to about 1 mm and the flattened mass is reintroduced into the mill, the friction of which has been suppressed, in order to draw from the mill a sheet having a thickness of 3 to 5 mm.

This sheet is placed in a mould and moulding takes place under a pressure (closing pressure of the mould) of 2.2 χ 107 Pa at a temperature of 170°C for 12 min. Slabs 200 x 200 x 1.5 mm in size are thus formed. - 9 All of the characteristics, the standards, the recommendations with regard to aeronautics and the values obtained with these slabs are collated in Table I.

TABLE I CHARACTERISTICS STANDARDS RECOMMENDATIONS VALUES OBTAINED Thickness 1.5 mm Density 1.68 Mass per m2 < 2 kg < 2kg (embossed slab) Dimensional stability NFT 54105 < 0.5% 0.2% Tear strength ISO 34-1979 14N/mm Abrasion Taber 1000 Δ p < 450 mg 316 mg resistance cycles grinding wheel H18/1 kg Load at break DIN 53455 > 9N/mm 13.4 N/mm Elongation at break DIN 53455 > 40% 50% Shore A hardness DIN 53505 77 ± 10 78 L.O.I. NFT 51071 None 49 Flammability FAR 25853 b t < 15s t = Os L < 203 nan L = 10 mm Fire resistance ATS 1000 - Passes 001 issue 4 L.O.I. = limiting oxygen index The same slabs were subjected to pyrolysis tests without a flame and with a flame in an N.B.S. chamber in - 10 accordance with ASTM standard E 662.

The results are collated in Table II.

TABLE II PYROLYSIS WITHOUT FLAME TIME OFFICIAL DENSITY (min) DS 1 0 2 0 3 0 4 0.1 5 0.4 6 0.7 7 1.9 PYRSOLYSIS WITH FLAME TIME OFFICIAL DENSITY (min) DS 1 0.1 2 1.4 3 6.4 4 41.9 5 94 6 120.2 7 128.3 Analysis of the combustion products of these slabs leads to the results collated in Table III - 11 TABLE III RESULTS GASES TESTED SPECIFICATION ATS 1000-001 issue 4 (maximum ppm allowable in 240 s) OBTAINED CO F 3500 200 10 NF 3500 0 NO + N02 F 100 26 NF 100 0 15 SO? + H?S F 100 0 NF 100 0 HF F 50 0 NF 50 0 20 HCl F 500 0 NF 500 0 HCN F 150 1 25 NF 150 0 F : pyrolysis with flame 30 NF: pyrolysis without flame EXAMPLE 2 The following are introduced successively into the two-roll mill mixer of Example 1: 1. - 100 parts of the polyphosphazene used in Example 1, 2.- 25 parts of precipitated silica (Example 1) parts of TiO2 0.5 parts of phenol derivative marketed under the trademark Irganox 1010 - 12 1 part of phosphate, trademark Santicizer 141, 3. - 110 parts of alumina trihydrate (Example 1), and 4. - 1 part of bis(t-butylperoxy)diisopropylbenzene.

Mixing and moulding are carried out following the 5 procedure described in Example 1, the moulding however taking 19 min.

The resulting are collated in Table IV. - 13 TABLE IV CHARACTERISTICS STANDARDS REOCMMENDATIGNS VAUJES Thickness 1.5 mm Density 1.61 Mass per m2 < 2 kg 2 kg (embossed slab) Dimensional stability NFT 54105 < 0.5% 0.5% Abrasion resistance Taber 1000 cycles grinding wheel H18/1 kg a P 450 mg 290 mg Puncture resistance < 10/100 mm <10/100 mm Scratch resistance Sclero- meter > 500 > 500 Crushing resistance None Good Load at break DIN 53455 > 9N/imn 9.2N/mm Elongation at break DIN 53455 > 40% 100% Shore A hardness DIN 53505 77 ± 10 81 L.O.I. None 49 Lightfastness ISO 4892 > 5 6 EXAMPLE 3 The following are introduced successively into the 45 mill of Example 1: - 100 parts of the polyphosphazene used in Example 1, - 14 - 0 or 10 parts of the phosphate used in Example 2, - 150 parts of alumina trihydrate used in Example 1, and - 2 parts of dicumyl peroxide.

After the mixing operations carried out using the 5 procedure described in Example 1, slabs 200 x 200 x 1.5 mm in size are moulded for 10 min at 170° under 2.2 x 107 Pa (closing pressure).

Measurements are carried out on these slabs and the results of these are collated in Table V.

TABLE V CHARACTERISTICS RESULTS without plasticiser RESULTS with plasticiser 30% modulus (MPa) 4.1 0.5 Breaking force (MPa) 7 3.5 Elongation at break (%) 57 260 Shore A hardness 89 55 L.O.I. 62.2 44.2 Tg (°C) 0.5 -13

Claims

1. A composition which can be used in the production of a floor covering usable in the aeronautics sector, which composition contains a polyphosphazene as 5 binder.

2. A composition according to claim 1, wherein the polyphosphazene is a high molecular weight polyphosphazene capable of being crosslinked or vulcanised.

3. A composition according to claim 1 or 2 10 wherein the polyphosphazene is a polymer containing a plurality of units of formula I: OR I -

4. - P = N 4- (I) 15 I OR in which each of the symbols R, which may be identical or different, represents an organic radical containing up to 12 carbon atoms. 20 4. A composition according to claim 3 wherein, in the formula I, each of the symbols R represents an aryl radical Rj optionally substituted by a halogen atom, by an alkyl radical having from 1 to 12 carbon atoms or by an alkoxy radical having from 1 to 6 carbon atoms, or an 25 alkenylaryl radical R 2 .

5. A composition according to claim 4, wherein, in the formula I, R predominantly represents an aryl - 16 radical R 1# and, in a proportion of less than 15%, represents an alkenylphenyl radical R 2 ·

6. A composition according to claim 4 or 5 wherein R^ represent phenyl, p-ethylphenyl, p-butylphenyl, 5 chlorophenyl or p-methoxyphenyl and R 2 represents oallylphenyl.

7. A composition according to any one of claims 1 to 6, wherein the polyphosphazene has a molecular mass by weight of more than 10,000. 10

8. A composition according to claim 7 wherein the polyphosphazene has a molecular mass by weight of 100,000 to 2,000,000.

9. A composition according to any preceding claim, which also contains, in addition to the binder, a 15 reinforcing filler also capable of improving the fire resistance of the composition and of the coating derived therefrom, a crosslinking or vulcanising agent or system and, optionally, one or more other additives, such as a protection agent, plasticiser or pigment. 20 10. A composition according to claim 9, wherein the crosslinking or vulcanising agent or system is chosen from the group comprising sulphur, optionally in combination with one or more activators or accelerators, and free-radical initiators. 25 11. A composition according to claim 10 wherein there is used as free-radical initiator a peroxide or - 17 perester. 12. A composition according to any one of claims 9 to 11 which contains up to 10 parts by weight of vulcanising or crosslinking agent or system per 100 parts 5 of polyphosphazene. 13. A composition according to any one of claims 9 to 12, which contains as reinforcing filler also capable of improving the fire resistance an alumina, magnesium hydroxide or magnesium carbonate.

10. 14. A composition according to any one of claims 9 to 13 which contains, per 100 parts by weight of polyphosphazene, up to 300 parts of filler, at least half of which comprises reinforcing filler capable of improving the fire resistance.

11. 15 15. A composition according to claim 14, which contains one or more reinforcing fillers capable of improving the fire resistance and precipitated silica.

12. 16. A composition according to claim 1 substantially as hereinbefore described. 20

13. 17. A composition which can be used in the production of a floor covering usable in the aeronautics sector substantially as described in any one of the Examples.

14. 18. Use of a composition as claimed in any one of 25 claims 1 to 17 in the production of covering material.

15. 19. A covering material formed by mixing the - 18 constituents and moulding a composition as claimed in any one of claims 1 to 17.