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CN-122003463-A - Use of fatty acid esters or alkoxylates as colour stabilizers in flame retardant polymer compositions

CN122003463ACN 122003463 ACN122003463 ACN 122003463ACN-122003463-A

Abstract

The invention relates to the use of fatty acid esters or alkoxylates thereof as color stabilizers in flame retardant polyamide compositions, wherein the fatty acid esters are formed by esterification of a monoglycerol with at least two C8-C32 saturated or unsaturated fatty acids. The invention is particularly useful in applications where both flame retardancy and color stability of the polyamide material are critical.

Inventors

  • E. M. Leshner
  • S. Herold

Assignees

  • 科莱恩国际有限公司

Dates

Publication Date
20260508
Application Date
20241016
Priority Date
20231030

Claims (13)

  1. 1. The use of a fatty acid ester or an alkoxylate thereof as a color stabilizer in a flame retardant polyamide composition, Wherein the fatty acid esters are formed by esterification of a mono-glycerol with at least two C8-C32 saturated or unsaturated fatty acids, And wherein the flame retardant polyamide composition comprises: one or more thermoplastic polyamides as component A), and Flame retardant composition comprising Dialkyl phosphinates of the formula (I) as component B) (I) Wherein the method comprises the steps of R 1 and R 2 are identical or different and are C 1 -C 18 alkyl, C 6 -C 18 aryl, C 7 -C 18 arylalkyl and/or C 7 -C 18 alkylaryl in linear, branched or cyclic form, M is Mg, ca, al, sb, sn, ge, ti, zn, fe, zr, ce, bi, sr, mn, li, na, K and/or a protonated nitrogen base; m is 1 to 4, and Fatty acid esters or alkoxylates thereof as component C).
  2. 2. The use according to claim 1, wherein the flame retardant composition comprises, 50 To 99% by weight and preferably 60 to 95% by weight of component B), and 1 To 40% by weight and preferably 5 to 35% by weight of component C), Each based on the total weight of the flame retardant composition.
  3. 3. The use according to any one of claims 1 or 2, wherein the C8-C32 saturated or unsaturated fatty acid is selected from the group consisting of caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, palmitic acid, stearic acid, oleic acid, arachic acid, eicosenoic acid, behenic acid, docosenoic acid, lignoceric acid, cerotic acid, montanic acid, shellac acid, tricetyl acid and mixtures thereof.
  4. 4. The use according to any one of claims 1-3, wherein the component C) is an alkoxylate and has from 1 to 10 alkoxy groups.
  5. 5. The use according to any one of claims 1 to 3, wherein component C) is a fatty acid ester formed by esterification of a mono-glycerol with at least two C12-C32 saturated or unsaturated fatty acids.
  6. 6. The use according to claim 5, wherein the C12-C32 saturated or unsaturated fatty acid is selected from oleic acid, cerotic acid, montanic acid, shellac acid, tricetyl acid and mixtures thereof.
  7. 7. The use according to any one of claims 1 to 6, wherein the flame retardant composition further comprises as compound E) a salt of phosphorous acid of formula (II) [HP(=O)O 2 ] 2- M' n+ (II) Wherein the method comprises the steps of M' is Mg, ca, al, sb, sn, ge, ti, zn, fe, zr, ce, bi, sr, mn, li, na and/or K, and is preferably Al; n is 1 to 4 and preferably 3.
  8. 8. The use of any of claims 1-7, wherein the flame retardant composition further comprises Condensation products of one or more melamines and/or reaction products of melamines with phosphoric acid and/or melamines as component F), and Zinc salts selected from zinc oxide, zinc borate and zinc stannate as component G).
  9. 9. The use of claim 1, wherein the one or more thermoplastic polyamides comprise aliphatic polyamides and semi-aromatic polyamides.
  10. 10. The use according to any one of claims 1-9, wherein the flame retardant polyamide composition further comprises As filler or reinforcing agent for component D).
  11. 11. The use according to any one of claims 1-10, wherein the flame retardant polyamide composition further comprises As pigments or dyes of the compounds H).
  12. 12. The use according to claim 11, wherein the flame retardant polyamide composition comprises, 30 To 95% by weight of component A), From 5 to 25% by weight of component B), 0.5 To 5% by weight of component C), 0 To 40% by weight of component D), 0 To 15% by weight of component E), 0 To 15% by weight of component F), 0 To 2% by weight of component G), and 0 To 5% by weight of component H), Wherein the sum of the components is always 100% by weight.
  13. 13. The use according to claim 11, wherein the flame retardant polyamide composition comprises, 30 To 90% by weight and preferably 35 to 85% by weight of component A), From 5 to 25% by weight and preferably from 8 to 20% by weight of component B), From 0.5 to 5% by weight and preferably from 1 to 4% by weight of component C), 10 To 40% by weight and preferably 15 to 35% by weight of component D), From 0 to 15% by weight and preferably from 1 to 10% by weight of component E), From 0 to 15% by weight and preferably from 1 to 10% by weight of component F), 0 To 2% by weight of component G), and 0 To 5% by weight of component H), Wherein the sum of the components is always 100% by weight.

Description

Use of fatty acid esters or alkoxylates as colour stabilizers in flame retardant polymer compositions Technical Field The present invention relates to a flame retardant composition using fatty acid esters or alkoxylates thereof to impart enhanced color change stability to polyamide materials. The invention also encompasses flame resistant polyamide compositions characterized by excellent resistance to discoloration. In its diverse applications, the composition is particularly suitable for use as a molding compound. Background In order to comply with stringent flame retardant standards imposed by plastics processors and industry regulatory authorities, it is generally considered necessary to incorporate flame retardants into polyamide compositions. There are various flame retardants and synergists that can be used for this purpose. In recent years, non-halogenated flame retardant systems have become popular due to their ability to produce low smoke density and less toxic smoke compositions during combustion, among other environmental benefits. Among non-halogenated flame retardants, salts of phosphinic acid (also known as phosphinates) have shown outstanding effectiveness as flame retardants, and in particular for thermoplastic polymers (DE-A-2252258 and DE-A-2447727). However, since relatively high doses of phosphinate flame retardants are required in thermoplastic polymers to achieve adequate flame resistance, the reactivity of these flame retardants in the polymer melt during high temperature processing can negatively impact the stability of the flame retardant polymer. For example, phosphinate flame retardants may cause the polyamide composition to change color immediately after melt processing (especially at temperatures near or above 300 ℃). DE-A-196 14 424 describes the use of phosphinates in combination with nitrogen-containing synergists in polyesters and polyamides. DE-A-199 33 901 describes the use of phosphinates in combination with melamine polyphosphate as a further flame retardant synergist for polyesters and polyamides. However, the use of these synergists with phosphinates in polyamide molding compounds leads to partial polymer degradation and thus to polymer discoloration, especially at processing temperatures close to or above 300 ℃. WO-up>A-2004/022640 has described means for reducing discoloration of such flame retardant polymers occurring during high temperature melt processing by adding basic or amphoteric oxides, hydroxides, carbonates, silicates, borates, stannates, mixed oxide hydroxides, oxide hydroxide carbonates, hydroxide silicates or hydroxides and/or borates to phosphinate flame retardants or synergistic mixtures thereof. However, flame retardant polyamide materials also undergo discoloration after prolonged exposure to aqueous media long after production by melt processing. It has been observed in WO-up>A-2019/076688 that storage of black polyamide materials containing phosphinate flame retardants in an aqueous medium for up>A long period of time can lead to discoloration of the material to grey. Such discoloration is observed in both the enhanced and unreinforced black polyamide test samples after storage in water at room temperature for one to seven days. The discoloration instability observed for flame retardant polyamide materials can cause significant problems in various applications, particularly in the automotive industry, where resistance of the polymer molding compound to various substances (e.g., windshield wipers) is critical. To alleviate this discoloration problem in flame retardant polyamide materials, WO-up>A-2019/076688 provides up>A solution that relies on the addition of at least one polyester to the polyamide composition. However, the incorporation of alternative polymers into polyamide materials may hamper their applicability to specific use cases where the polyamide serves as the main polymer component to obtain the desired mechanical properties, in particular with respect to tensile strength and elongation at break, as shown in the examples shown in WO-up>A-2019/076688. Furthermore, the inventors have observed that the discoloration of polyamides is significantly exacerbated when exposed to elevated ambient temperatures (particularly 40 ℃ or higher). The prior art WO-up>A-2019/076688 does not address or provide up>A remedy for such high temperature induced polyamide discoloration. It is therefore an object of the present invention to provide a new solution to the problem of color instability of flame retardant polyamide materials when exposed to water at room temperature or higher without compromising their flame retardancy and mechanical properties. Disclosure of Invention This object is achieved by using fatty acid esters or alkoxylates thereof as color stabilizers in flame retardant polyamide compositions, wherein the fatty acid esters are formed by esterification of a monoglyceride with at least two C8-C32 saturated or unsaturated fatty acids, And wh