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WO-2026093052-A1 - FLAME RETARDANT ARTICLES COMPRISING POLYPROPYLENE

WO2026093052A1WO 2026093052 A1WO2026093052 A1WO 2026093052A1WO-2026093052-A1

Abstract

The invention concerns an article, the article being a film or a fibre or a tape, comprising a flame-retardant polypropylene polymer composition which comprises the components: (i) a polypropylene polymer substrate; and (ii) a thio compound of formula (I); and either or both of (iii) at least one sterically hindered amine ether; and/or (iv) at least one phosphorus compound selected from at least one of phosphinate, phosphonate, phosphate and alkali metal hypophosphite, (I) wherein A is based on an organic isocyanate or a (meth)acrylate, wherein the radical(s) -S–R are introduced by reaction with isocyanate groups or (meth)acrylate groups, R is C 2 -C 40 alkyl which is optionally substituted and/or interrupted, and n is equal to or greater than 1. The invention also includes a method for preparing the article. Also claimed is use of (ii) a thio compound of formula (I) in conjunction with either or both of (iii) at least one sterically hindered amine ether and/or (iv) at least one phosphorus compound, the phosphorus compound being at least one of phosphinate, phosphonate, phosphate or alkali metal hypophosphite. The invention further includes an additive mixture comprising these three components and also a composition comprising the additive mixture and a polypropylene polymer substrate (i).

Inventors

  • MENOZZI, EDOARDO
  • Gerster, Michèle
  • LIPS, GERARD
  • Müller, Daniel
  • WUNDERLICH-WIPPERT, WIEBKE

Assignees

  • BASF SE

Dates

Publication Date
20260507
Application Date
20251020
Priority Date
20241028

Claims (20)

  1. Claims
  2. 1. An article, the article being a film or a fibre or a tape, comprising a flame-retardant polypropylene polymer composition which comprises the components,
  3. (i) a polypropylene polymer substrate; and
  4. (ii) a thio- compound of formula (I);
  5. and either or both of
  6. (iii) at least one sterically hindered amine ether; and/or
  7. (iv) at least one phosphorus compound selected from at least one of phosphinate, phosphonate, phosphate and alkali metal hypophosphite,
  8. (I)
  9. n
  10. wherein
  11. A is based on an organic isocyanate or a (meth)acrylate, wherein the radical(s) - S-R are introduced by reaction with isocyanate groups or (meth)acrylate groups, R is C 2 -C 40 alkyl which is optionally substituted and/or interrupted, and
  12. n is equal to or greater than 1.
  13. 2. The article according to claim 1, wherein A is based on an organic isocyanate, the organic isocyanate being a cyclohexyl diisocyanate, methylenebis(cyclohexyl) diisocyanate, isophorone diisocyanate, phenyl diisocyanate, diphenylmethane diisocyanate or naphthyl diisocyanate each of which is unsubstituted or substituted by C1-C4 alkyl or di(C1-C4 alkyl) amino, or is C4-C20 alkyl diisocyanate, or an oligomeric or polymeric product obtained by the reaction of the above isocyanates with themselves and/or a polyol.
  14. 3. The article according to claim 1 or claim 2, wherein A is based on an organic isocyanate, the organic isocyanate being a phenyl diisocyanate, diphenylmethane diisocyanate or naphthyl diisocyanate each of which is unsubstituted or substituted by C1-C4 alkyl or di(C1-C4 alkyl)amino, or an oligomeric or polymeric product obtained by the reaction of the above isocyanates with themselves and/or a polyol. 4. The article according to any of claims 1 to 3, wherein A is based on an organic isocyanate, the organic isocyanate being a phenyl diisocyanate which is unsubstituted or substituted by C1-C4 alkyl or di(C1-C4 alkyl)amino, or an oligomeric or polymeric product obtained by the reaction of the above isocyanates with themselves and/or a polyol.
  15. 5. The article according to claim 1, wherein A is based on an acrylate or a methacrylate, the acrylate or methacrylate being an ester of a polyol.
  16. 6. The article according to any of claims 2 to 5, wherein the polyol is a C1-C10 alkanol comprising two or more hydroxy groups, or a poly-C 2 -C 10 alkylene glycol, preferably a C3-C8 alkanol comprising two or more hydroxy groups.
  17. 7. The article according to any of claims 1 to 6, wherein R is C 2 -C 40 alkyl which is uninterrupted or interrupted by -O-, -NH-, -S- and/or a carbonyl group, preferably wherein R is C 8 -C 40 alkyl which is uninterrupted or interrupted by -O- and/or a carbonyl group, more preferably wherein R is C 10 -C 22 alkyl which is uninterrupted or interrupted by -O- and/or a carbonyl group, more preferably still wherein R is an uninterrupted C 11 -C 21 alkyl.
  18. 8. The article according to any of claims 1 to 7, wherein the at least one sterically hindered amine ether is selected from the compounds of formula (III), compounds of formula (IV), compounds of formula (V), compounds of formula (VI), compounds of formula (VII), compounds of formula (VIII), and compounds of formula (IX),
  19. (III),
  20. wherein R1 and R2 are independently selected from formula (Illa),

Description

Flame retardant articles comprising polypropylene Field of the Invention The present invention is in the field of flame-retardant articles that comprise polypropylene polymer. The invention concerns an article, the article being a film or a fibre or a tape, which comprises a flame-retardant polypropylene polymer composition comprising a polypropylene polymer substrate; a thio compound of formula (I); and either or both of at least one sterically hindered amine ether; and/or at least one phosphorus compound, the phosphorus compound being at least one of phosphinate, phosphonate, phosphate and alkali metal hypophosphite. The invention further concerns a method for preparing the article and the use of the thio compound in conjunction with the sterically hindered amine ether and/or aforesaid phosphorus compound for improving the flame retardancy of a polypropylene based article. In addition, the invention includes an additive mixture comprising the aforesaid thio compound and at least one sterically hindered amine ether and/or at least one aforesaid phosphorus compound. The invention also includes a composition comprising a polypropylene polymer substrate and the said additive mixture. Background of the Invention Polypropylene is a thermoplastic polymer and has different applications, for instance components in automobiles, automotive products, textiles, medicine, furniture, electronic casings and interior decoration are just a few examples. Polypropylene, like other organic substances, including polyolefins, is a flammable material. It is therefore typical to render polypropylene more flame retardant by the addition of additives which reduce or prevent combustion. Flame retardant additives found to be effective for polypropylene include halogenated compounds, such as bromine or chlorine, which are commonly used for polypropylene. When exposed to fire, these halogenated compounds undergo chemical reactions that release gas, such as hydrogen bromide or hydrogen chloride. This can have the effect of diluting the oxygen concentration in the combustion zone and therefore inhibiting flame propagation. Further, such halogen-containing gases can act as free radical scavengers which can serve the purpose of interrupting the chain reactions that sustain the combustion process. Other known flame retardants commonly used for polypropylene include phosphorus-based compounds. Such phosphorus-containing compounds can undergo thermal decomposition when exposed to high temperatures and can form protective charred layers over the surface of the polypropylene which in effect acts as a barrier that will shield material below it from heat and flames. Such an insulating layer would have the benefit of reducing heat transfer and preventing further flame propagation. Further, other classes of compounds are proposed to function in the condensed and/or vapour phase. Metal hydrates or metal oxides are proposed to generate water vapour under thermal conditions, the water acting to dilute the fuel mix in the combustion zone and to remove heat from the flame zone via conversion of water to vapour. Alumina trihydrate, magnesium hydroxide or oxide, and other compounds are reported to function in this way. It is also common practice to combine halogenated compounds and phosphorus-based additives to improve flame retardancy of polypropylene. Such combination is said to combine the benefits of each additive. International Application No W02007010318 A discloses flame retardant thermoplastic moulding compositions comprising polyolefinic polymer particularly polypropylene polymers, a synergic mixture of a hypophosphorous acid metal salt and halogenated organic compounds, a plurality of selected additives consisted of processing aids, heat and process stabilisers, UV stabilisers, anti-dripping agents etc. It is also known to employ halogenated organic phosphorus compounds as flame retardants. United States Patent No. US5393812 describes polyolefin compositions which are made flame retardant by a combination of a halogenated hydrocarbyl phosphate or phosphonate ester flame retardant in combination with an alkoxyamine functional hindered amine. European Patent Application No EP0792911 A discloses that alkoxyamine functional hindered amines are effective when used to enhance the flame retardancy efficacy of tris(trihalogenopentyl) phosphate flame retardants. The use of the halogenated flame retardants can, however, have various detrimental consequences in addition to the effective flame retarding attributes described. Certain organo-brominated compounds are under governmental scrutiny for the generation of toxic byproducts during the production or combustion such as dioxins from polybrominated diphenyl oxides. Furthermore, there is a desire to move away from halogenated flame retardants to avoid the generation of corrosive hydrogen halide gases. The use of certain metal oxides can also be disadvantageous. Certain metalcontaining flame retardan