# US 2025/0145752 A1 · Crosslinked polyesters with reduced flammability

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2025/0145752 A1
- Document ID: US20250145752A1
- Status: Published application
- Kind: A1
- Application number: 18/835,871
- Filed: 2023-03-05
- Published: 2025-05-08
- Earliest claimed: 2022-03-10
- Assignees: Bromine Compounds Ltd.
- Applicants: Bromine Compounds Ltd.
- Inventors: Shay DICHTER; Joseph ZILBERMAN; Dov BERUBEN; Eyal EDEN; Marc LEIFER
- Web page: https://patentgrep.com/patent/US20250145752A1

## CPC

- C08F 283/01: on to unsaturated polyesters {(C08F283/004 takes precedence)}
- C07C 67/08: by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## 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.

## Claims

### 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:

### Claim 2 (depends on 1)

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

### Claim 3 (depends on 1)

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.

### Claim 4 (depends on 1)

A composition according to claim 1, comprising an accelerator.

### Claim 5 (depends on 4)

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

### Claim 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.

### Claim 7 (depends on 6)

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

### Claim 8 (depends on 6)

Crosslinked polyester obtainable by the methods of claim 6.

### Claim 9

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

### Claim 10 (depends on 9)

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.

### Claim 11 (depends on 9)

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.

### Claim 12 (depends on 11)

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.

### Claim 13 (depends on 10)

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.

### Claim 14 (depends on 12)

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

### Claim 15 (depends on 14)

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.