Flame retardant formulations for wood coating

Patent metadata

Field	Value
Publication number	US-2023365817-A1
Application number	US-202118041062-A
Country	US
Kind code	A1
Filing date	Aug 9, 2021
Priority date	Aug 10, 2020
Publication date	Nov 16, 2023
Grant date	—

Abstract

Flame retardant coating formulation in the form of an aqueous dispersion comprising a binder, particles of a brominated polymeric flame retardant; and particles of at least one of magnesium hydroxide and aluminum trihydrate, wherein the aqueous dispersion is substantially free of antimony oxide. A process for preparing the formulation and a method of reducing the flammability of wood and wood products by coating them with the formulation are also provided.

First claim

1 . Flame retardant coating formulation in the form of an aqueous dispersion comprising a binder, particles of a brominated polymeric flame retardant (BFR); and particles of at least one of magnesium hydroxide and aluminum trihydrate, wherein the aqueous dispersion is substantially free of antimony oxide.

2 . A flame retardant coating formulation according to claim 1 , wherein the brominated polymeric flame retardant is tribromophenol end-capped brominated epoxy polymer of the formula Ia:
wherein m is the degree of polymerization.

3 . A flame retardant coating formulation according to claim 1 ,wherein the brominated, polymeric flame retardant is brominated poly [styrene-co-butadiene].

4 . A flame retardant coating formulation according to claim 1 , wherein the brominated polymeric flame retardant is brominated polystyrene.

5 . A flame retardant coating formulation according to claim 1 , wherein the binder is an acrylate resin or a polyurethane resin.

6 . A flame retardant coating formulation according to claim 1 , comprising magnesium hydroxide.

7 . A Flame retardant coating formulation according to claim 6 , comprising :
from 10 to 50 % by weight of water; from 10 to 35 % by weight of acrylate resin; from 5 to 25 % by weight of tribromophenol end-capped brominated epoxy polymer of the formula Ia; and from 2 to 10 % by weight of Mg(OH) 2 .

8 . A flame retardant coating formulation according to claim 6 , comprising :
from 10 to 50 % by weight of water; from 10 to 35 % by weight of acrylate resin; from 5 to 25 % by weight of brominated poly [styrene-co-butadiene]; and from 2 to 10 % by weight of Mg(OH) 2 .

9 . A flame retardant coating formulation according to claim 6 , comprising :
from 10 to 50 % by weight of water, from 10 to 35 % by weight of acrylate resin; from 5 to 25 % by weight of brominated polystyrene; and from 2 to 10 % by weight of Mg(OH) 2 .

10 . A flame retardant coating formulation according to claim 1 , further comprising one or more of additives selected from dispersants, wetting agents, coalescing agents, defoamers, substrate wetting agents and rheology modifiers.

11 . A flame retardant coating formulation according to claim 10 , comprising a combination of nonionic dispersant and an anionic dispersant.

12 . A flame retardant coating formulation according to claim 11 , wherein the anionic dispersant is polyacrylate or polyphosphate salt.

13 . A flame retardant coating formulation according to claim 12 , wherein the anionic dispersant is polyacrylate sodium salt.

14 . A flame retardant coating formulation according to claim 5 , wherein the acrylic resin is self-crosslinking acrylic resin.

15 . A flame retardant coating formulation according to claim 1 , wherein the polyurethane resin is an aliphatic polyester polyurethane.

16 . A flame retardant coating formulation according to claim 1 , which is free of antimony oxide.

17 . A process for preparing a flame retardant coating formulation for wood, comprising incorporating magnesium hydroxide or alumina trihydrate powder, and brominated polymeric flame retardant powder, into a water-based binder dispersion, wherein the coating formulation is substantially free of metal oxide synergist.

18 . A process according to claim 17 , wherein the binder is an acrylate resin or a polyurethane resin.

19 . A process for preparing flame retardant coating formulation according to claim 17 , comprising the steps of:
1a) adding magnesium hydroxide powder to water in the presence of a dispersant and optionally a wetting agent under high shear, to form Mg(OH) 2 aqueous dispersion: 1b) adding BFR powder to the Mg(OH) 2 aqueous dispersion, to form BFR/Mg(OH) 2 aqueous dispersion; 2) combining the BFR/Mg(OH) 2 aqueous dispersion with water-based acrylic resin to form the flame retardant coating formulation; wherein the process further comprises incorporating one or more of dispersants, wetting agents, coalescing agents, defoamers, substrate wetting agents and rheology modifiers into the Mg(OH) 2 aqueous dispersion, the BFR/Mg(OH) 2 aqueous dispersion, the water-based acrylic resin and/or the flame retardant coating formulation.

20 . A process according to claim 17 , wherein the magnesium hydroxide powder possesses particle size distribution of d 50 ≤3 µm and d 90 ≤ 6 µm; and the BFR powder possesses particle size distribution of d 50 <5 µm and d 90 < 10, measured by laser diffraction.

21 . A process according to claim 19 , comprising adding nonionic dispersant to the water in step 1a and/or to the water based acrylic resin in step 2, and anionic dispersant to the water- based acrylic resin in step 2.

22 . A method of reducing the flammability of wood and wood products, comprising applying the flame retardant aqueous dispersion of claim 1 to the surface of the wood or the wood product, to form a coating thereon.

Assignees

• Bromine Compounds Ltd

Inventors

• Abecassis Wolfovich Meyrav
• Swissa Smadar
• Lison Jakub
• Alessio Gerald R

Classifications

• C09D5/18 Primary

  Fireproof paints {including high temperature resistant paints} · CPC title

• C09D5/027

  Dispersing agents (anti-settling agents C09D7/45) · CPC title

• C09D7/45

  Anti-settling agents · CPC title

• C09D7/61

  inorganic · CPC title

• C09D7/65

  macromolecular (C09D7/41-C09D7/48 take precedence) · CPC title