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EP-4741455-A2 - NEW FLAME RETARDANT

EP4741455A2EP 4741455 A2EP4741455 A2EP 4741455A2EP-4741455-A2

Abstract

The invention relates to a flame retardant, a plastic composition comprising this flame retardant and a polyphosphate salt.

Inventors

  • FUTTERER, THOMAS
  • GARCIA MARTINEZ, DAVID
  • MOSCHEL, Sebastian
  • ROCHHOLZ, HEIKO
  • Moss, Tobias
  • ABELE, BORS CAJUS

Assignees

  • Chemische Fabrik Budenheim KG

Dates

Publication Date
20260513
Application Date
20220722

Claims (13)

  1. Flame retardant comprising a polyphosphate salt, wherein the polyphosphate salt has cations of at least one 1,3,5-triazine compound, one of which is melamine. characterized by the fact that The flame retardant comprises at least one condensation product of melamine.
  2. Flame retardant according to claim 1, wherein the at least one condensation product of melamine is one of the at least one 1,3,5-triazine compound whose cations comprise the polyphosphate salt.
  3. Flame retardant according to one of the preceding claims, wherein the amount of melamine cations in the flame retardant is X and the amount of at least one melamine condensation product is Y, and wherein the proportion of Y in the sum of the amounts of X+Y is ≥ 1%, preferably ≥ 2%.
  4. Flame retardant according to one of the preceding claims, wherein the average degree of condensation n of the polyphosphate salt is 10 to 500, preferably 20 to 250.
  5. Flame retardant according to any of the preceding claims, wherein the at least one condensation product of melamine is preferably selected from the group consisting of melam, melem or melon, preferably melam.
  6. Flame retardant according to any of the preceding claims, wherein the pH value of a 10 wt.% suspension of the flame retardant and/or the polyphosphate salt in water at 25°C is ≥ 5.
  7. Flame retardant according to one of the preceding claims, wherein the stoichiometric ratio of the sum of the amounts of the at least one 1,3,5-triazine compound and the amount of the at least one condensation product of melamine to phosphorus is ≤ 1.3, preferably ≤ 1.1.
  8. Flame retardant according to any of the preceding claims, wherein the cations of the at least one 1,3,5-triazine compound constitute ≥ 90% of the total proportion of cations of the polyphosphate salt.
  9. Flame retardant according to any of the preceding claims, wherein the water solubility of the flame retardant and/or the polyphosphate salt is ≤ 0.1 g /100 ml, preferably ≤ 0.07 g /100 ml.
  10. Flame retardant according to any of the preceding claims, wherein the decomposition temperature of the flame retardant and/or the polyphosphate salt is > 320°C.
  11. Flame retardant according to claim 10, wherein this comprises as an additional component at least one compound selected from the group consisting of phosphinates, diphosphinates such as aluminium diethyl phosphinate, zinc borates and zinc phosphates.
  12. A plastic composition comprising a plastic matrix and a flame retardant as defined in any of the preceding claims.
  13. Polyphosphate salt as defined in any one of claims 1 to 10.

Description

Subject matter of the invention The invention relates to a flame retardant, a plastic composition comprising this flame retardant and a polyphosphate salt. Background of the invention Numerous substances are known for flame-retardant treatment of plastics, which can be used alone or in combination with other substances that provide similar or synergistic flame-retardant properties. The prior art, for example, reveals the use of polyphosphate salts of 1,3,5-triazine compounds for such applications. These are incorporated, in particular, into polyamides and polyesters (with and without glass fibers), which are typically processed by injection molding, i.e., at elevated temperatures, using plastic extrusion. From the WO 00/02869 A1 Are there any polyphosphate salts of 1,3,5-triazine compounds known which have a mean condensation level (number average) > 20 and a molar ratio of triazine compound to phosphorus (M/P) of < 1.1? The EP 0 974 588 B1 This document describes 1,3,5-triazine derivatives of polyacids containing phosphorus, sulfur, and oxygen, as well as a process for their preparation. The ratio of 1,3,5-triazine compound to phosphorus in the disclosed triazine polyphosphate derivatives is > 1.1. Even the EP 1 095 030 B1 This describes a polyphosphate salt of a 1,3,5-triazine compound. It has a 1,3,5-triazine content of 1.1 to 2.0 mol of a triazine compound selected from the group consisting of melamine, melam, melem, melon, ammelin, ammelide, 2-ureidomelamine, acetoguanamine, benzoguanamine, and diaminephenyltriazine, per mol of phosphorus atom. These polyphosphate salts, known from the prior art, generally only provide moderate flame retardancy when incorporated into a composition requiring protection. Furthermore, these phosphate salts tend to migrate out of the material over time. This not only further reduces the flame-retardant effect, but the release of these salts also poses health risks, particularly in household applications. Additionally, processing the product using an extruder, especially at temperatures above 250°C, leads to the decomposition of the flame retardant and a rough surface on the extruded material. This effect is particularly pronounced when the flame retardant is incorporated into a glass fiber reinforced plastic. Processing becomes especially difficult when, in addition to the primary flame retardant and fillers, other synergistic flame retardants are present, such as products based on phosphinates like aluminum diethyl phosphinate. TASK Against this background, the object of the present invention was therefore to provide a preferably halogen-free, environmentally friendly, and in particular recyclable flame retardant based on a polyphosphate salt of the aforementioned type, which exhibits similar or even better flame-retardant properties than those known from the prior art and which, moreover, has a lower tendency to migrate, so that a durable and safe flame retardant can be achieved, especially for polymer materials. The present invention is also intended to ensure unrestricted processability of the polymer material containing the flame retardant, even in multi-step processing and at high temperatures. Description of the invention This problem is solved by a flame retardant according to claim 1. The flame retardant according to the invention comprises at least one polyphosphate salt having cations of at least one 1,3,5-triazine compound, one of which is melamine. It is therefore a polyphosphate salt of a 1,3,5-triazine compound. Preferably, the polyphosphate salt comprises cations of two or more 1,3,5-triazine compounds. The "cations of at least one 1,3,5-triazine compound" of the polyphosphate salt are preferably the corresponding cations of the 1,3,5-triazine compound(s) obtained by protonation. These are generally the corresponding ammonium ions of the 1,3,5-triazine compound(s), which typically contain amino groups, such as melamine, melam, or melem. According to the invention, the flame retardant further comprises at least one, i.e., one or more condensation products of melamine. The term "condensation product" of melamine refers to molecules formed by a condensation reaction of two or more melamine molecules, such as melam, melem, or melon. This term also includes the protonated forms of these compounds, i.e., the corresponding cations obtained through protonation. In a preferred embodiment of the invention, the flame retardant according to the invention has such a cationic form of a condensation product of melamine, wherein this cation is preferably a cation of the polyphosphate salt, i.e., another of the at least one 1,3,5-triazine compound of the polyphosphate salt. The polyphosphate salt then thus has at least cations of melamine and a condensation product of melamine, such as melam. In this case, the flame retardant can consist exclusively of the polyphosphate salt. Such a polyphosphate salt can be obtained by adding the condensation product of melamine during pro