Crosslinked polyesters with reduced flammability

Patent metadata

Field	Value
Publication number	US-2025145752-A1
Application number	US-202318835871-A
Country	US
Kind code	A1
Filing date	Mar 5, 2023
Priority date	Mar 10, 2022
Publication date	May 8, 2025
Grant date	—

Abstract

The invention relates to a composition comprising an unsaturated polyester dissolved in a monomer solution together with trinol (meth) acrylate, wherein the composition is essentially free of tribromoneopentyl alcohol (TBNPA) of the formula: A trinol (meth) acrylate-crosslinked polyester obtained by curing the solution, and a process for preparing an essentially TB-NPA-free trinol (meth) acrylate, are also provided by the invention.

First claim

1 . A composition comprising an unsaturated polyester dissolved in a monomer solution together with trinol (meth)acrylate, wherein the composition is essentially free of tribromoneopentyl alcohol (TBNPA) of the formula:

2 . A composition according to claim 1 , comprising from 25 to 45 phr trinol acrylate of the formula:

3 . A composition according to claim 1 , wherein the concentration of TBNPA is less than 0.3 wt. %, calculated based on the total weight of the composition.

4 . A composition according to claim 1 , comprising an accelerator.

5 . A composition according to claim 4 , comprising a free radical initiator.

6 . A method of improving the fire-resistance of a crosslinked polyester, comprising:
adding an essentially TBNPA-free trinol (meth)acrylate, accelerator and a free radical initiator to a solution of unsaturated polyester in a monomer solvent, thereby forming a curable composition, and initiating crosslinking, to crosslink the polyester.

7 . A method according to claim 6 , wherein the concentration of TBNPA in the curable composition is less than 0.3 wt. %.

8 . Crosslinked polyester obtainable by the methods of claim 6 .

9 . A trinol (meth)acrylate-crosslinked polyester, with less than 0.3 wt. %. of TBNPA, based on the total weight of the crosslinked polyester.

10 . A trinol (meth)acrylate-crosslinked polyester according to claim 9 , wherein the bromine content of the crosslinked polyester is from 14 to 18 percent by weight, with no bromine atoms alongside the polyester backbone chain, bromine atoms being exclusively incorporated in the structural unit corresponding to the trinol a(meth)acrylate that join two polyester chains together, wherein the concentration of non-copolymerized TBNPA is less than 0.1 wt. %, calculated based on the total weight of the crosslinked polyester.

11 . A process for preparing an essentially TBNPA-free trinol (meth)acrylate of claim 9 , comprising:
reacting (meth)acrylic acid with TBNPA:

at a molar excess of the acid, to form a reaction mixture comprising trinol (meth)acrylate and residual TBNPA;
adding to the reaction mixture a scavenger reactive towards an alcohol to eliminate residual TBNPA; and
recovering essentially TBNPA-free trinol (meth)acrylate.

12 . A process according to claim 11 , wherein the reaction of (meth)acrylic acid and TBNPA takes place in an organic solvent in the presence of an esterification catalyst and a polymerization inhibitor at reflux temperature, water formed is removed through azeotropic distillation while the organic solvent is condensed and returned to the reaction vessel.

13 . A process according to claim 10 , wherein the scavenger added is an esterification agent whose reactivity towards an alcohol is stronger than that of (meth)acrylic acid, the scavenger being selected from reactive derivatives of (meth)acrylic acid.

14 . A process according to claim 12 , wherein the esterification agent is (meth)acrylic anhydride or acryloyl chloride:

15 . The process according to claim 14 , wherein the esterification reaction to remove TBNPA takes place under heating, using methacrylic anhydride in the presence of a nitrogen-containing organic base to catalyze the esterification reaction of TBNPA and methacrylic anhydride.

Assignees

• Bromine Compounds Ltd

Inventors

• Dichter Shay
• Zilberman Joseph
• Beruben Dov
• Eden Eyal
• Leifer Marc

Classifications

• C07C67/08 Primary

  by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds · CPC title

• C08F283/01 Primary

  on to unsaturated polyesters {(C08F283/004 takes precedence)} · CPC title