Reinforcement member comprising a structural adhesive on a polyester carrier

Patent metadata

Field	Value
Publication number	US-11124678-B2
Application number	US-201615560918-A
Country	US
Kind code	B2
Filing date	Mar 24, 2016
Priority date	Mar 25, 2015
Publication date	Sep 21, 2021
Grant date	Sep 21, 2021

Abstract

The invention relates to a reinforcement member comprising a heatcurable structural adhesive on a carrier member, wherein the carrier member comprises a fiber-reinforced polyester material. The invention further relates to a method to produce such a reinforcement member and its use.

First claim

The invention claimed is:

1. A reinforcement member comprising:
a foamable heat curable structural adhesive on one or more outer surfaces of a hollow carrier member and covering at least 50% of the carrier member to form one ring with the carrier member and connect to the carrier member free of seams, the heat curable structural adhesive foaming to not more than about 200% of its original unexpanded volume, wherein the carrier member has a cross-section that does not comprise a constant thickness over its entire extension;
wherein the carrier member comprises a fiber-reinforced polyester material having a first aromatic polyester and a second aromatic polyester, and the content of the fibers is within the range of about 65±5 wt.-%, relative to the total weight of the fiber-reinforced polyester material and at least 99 wt.-% of the carrier member is composed of the fiber-reinforced polyester material relative to the total weight of the fiber-reinforced polyester material;
wherein the fiber-reinforced polyester material has a degree of crystallinity of at least 60%,
wherein the fibers are associated into bundles with a polyamide terpolymer binder and the fibers have an average length in the range of about 100±50 μm;
wherein the carrier member has an E-modulus of at least about 15 Gpa that is maintained independent of relative humidity of the ambient air;
wherein the heat curable structural adhesive forms a non-uniform coating along the carrier member so that an outer shape of the reinforcement member differs from an outer shape of the carrier member.

2. The reinforcement member according to claim 1 , wherein the first aromatic polyester and the second aromatic polyester are derived from one or more aromatic dicarboxylic acids and/or one or more aliphatic diols.

3. The reinforcement member according to claim 2 , wherein the one or more aromatic dicarboxylic acids are selected from the group consisting of phthalic acid, isophtalic acid, terephthalic acid, and mixtures thereof.

4. The reinforcement member according to claim 2 , wherein the one or more aliphatic diols are selected from ethylene glycol, propylene glycol, butylene glycol, pentylene glykol, hexylene glycol, and the mixtures thereof.

5. The reinforcement member according to claim 1 , wherein the polyester material comprises a blend of aromatic polyesters selected from the group consisting of polyethylene terephthalate, modified polyethylene terephthalate, polybutylene terephthalate, and modified polybutylene terephthalate.

6. The reinforcement member according to claim 5 , wherein the polyester material comprises a blend of polybutylene terephthalate and polyethylene terephthalate.

7. The reinforcement member according to claim 5 , wherein the first polyester, the second polyester, or both comprise recycled polyester.

8. The reinforcement member according to claim 5 , wherein the relative weight ratio of the first aromatic polyester to the second aromatic polyester is within the range of 0:1.5 to 1.5:1.

9. The reinforcement member according to claim 8 , wherein the heat curable structural adhesive is foamable and comprises, relative to the total weight of the heat curable structural adhesive:
(a) 25 wt.-% to 45 wt.-% of an aromatic epoxy resin;
(b) not more than 20 wt.-% of a flexibilizer, wherein the flexibilizer is a hydroxy terminated urethane polymer or prepolymer;
(c) 2 wt.-% to 6 wt.-% of a curing agent, wherein the curing agent is aliphatic or aromatic;
(d) 2 wt.-% to 6 wt.-% of one or more curing accelerators;
(e) not more than 30 wt.-% of an impact modifier; and
(f) 0.001 wt.-% to 2 wt.-% of a blowing agent.

10. The reinforcement member according to claim 9 , wherein the first aromatic polyester is polybutylene terephthalate (PBT) and the second aromatic polyester is polyethylene terephthalate (PET).

11. The reinforcement member according to claim 10 , wherein the first aromatic polyester and the second aromatic polyester are each modified by adding cyclohexane dimethanol to the polymer backbone of the first aromatic polyester in place of a portion of the butylene glycol and adding cyclohexane dimethanol to the polymer backbone of the second aromatic polyester in place of a portion of the ethylene glycol.

12. The reinforcement member according to claim 11 , wherein the heat curable structural adhesive comprises an impact modifier, a flexibilizer, and an elongation promoting additives.

13. The reinforcement member according to claim 12 , wherein the heat curable structural adhesive comprises a flexibilizer and the flexibilizer is hydroxy terminated urethane polymers or prepolymers.

14. The reinforcement member according to claim 13 , wherein the heat curable structural adhesive comprises, relative to the total weight of the heat curable structural adhesive, not more than about 20 wt.-% flexibilizer.

15. The reinforcement member according to claim 13 , wherein the flexibilizer is a hydroxy terminated urethane polymer or prepolymer.

16. The reinforcement member according to claim 1 , wherein the heat curable structural adhesive comprises an epoxy resin as well as a curing agent, and additionally
a curing accelerator;
an impact modifier selected from epoxy functionalized impact modifiers and core/shell impact modifiers;
a flexibilizer of hydroxy terminated urethane prepolymers
a blowing agent in combination with a blowing accelerator;
a phenoxy resin thermoplastic modifier that is a reaction product of epoxydized bisphenol A with bisphenol A; and
an adhesion promoter of amine or epoxy functional silanes.

17. The reinforcement member according to claim 16 , wherein the first aromatic polyester is polybutylene terephthalate (PBT) and the second aromatic polyester is polyethylene terephthalate (PET).

18. The reinforcement member according to claim 17 , wherein the heat curable structural adhesive is a coating of the fiber-reinforced polyester material.

19. The reinforcement member according to claim 16 , wherein the heat curable structural adhesive comprises, relative to the total weight of the heat curable structural adhesive, 25 wt.-% to 45 wt.-% of the epoxy resin.

20. The reinforcement member according to claim 16 , wherein the epoxy resin is an aromatic epoxy resin.

Assignees

• Zephyros Inc
• L&L Products Europe Sas

Inventors

• Chopin Eric

Classifications

• C09J2301/122

  the adhesive layer being present only on one side of the carrier, e.g. single-sided adhesive tape · CPC title

• C09J7/255 Primary

  Polyesters · CPC title

• C09J2463/00

  Presence of epoxy resin · CPC title

• C08J2367/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds; (C08J2367/06 takes precedence) · CPC title

• C08L67/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence) · CPC title