Liquid (meth)acrylic syrup for impregnating a fibrous substrate and method for the production thereof, method for impregnating a fibrous substrate, and composite material produced after polymerisation of said pre-impregnated substrate

Patent metadata

Field	Value
Publication number	US-10040934-B2
Application number	US-201414772847-A
Country	US
Kind code	B2
Filing date	Mar 7, 2014
Priority date	Mar 8, 2013
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

The invention relates to a liquid (meth)acrylic syrup for impregnating a fibrous substrate. The invention especially relates to a viscous liquid syrup mainly containing methacrylic or acrylic components. The invention also relates to a method for producing such a syrup. The invention relates further to a process for impregnating a fibrous substrate or long fibers with said viscous liquid syrup. The invention also relates to a fibrous substrate preimpregnated with said syrup, which is useful for the production of mechanical or structured parts or products. The invention also relates to a production method for producing mechanical or structured parts or items and to three-dimensional mechanical or structured parts produced by said method. The invention applies to the production of mechanical parts or structural elements made of impact-resistant thermoplastic composite material.

First claim

The invention claimed is:

1. A liquid (meth)acrylic syrup for impregnating a fibrous substrate, said fibrous substrate consisting of long fibers, having a diameter between 0.005 micrometers and 100 micrometers, and an aspect ratio of 1000 or greater, said syrup comprising:
a) a (meth)acrylic polymer,
b) a (meth)acrylic monomer,
c) elastomeric domains consisting of macromolecular blocks of flexible nature, that are part of a block copolymer, wherein said macromolecular blocks are not prepared from a diene, and wherein said elastomeric macromolecular blocks are between 5% and 15% by weight, with a glass transition temperature of less than 0° C., and which are soluble in the (meth)acrylic monomer, said liquid (meth)acrylic syrup having a dynamic viscosity of between 10 mPa·s and 10 000 mPa·s.

2. The liquid (meth)acrylic impregnation syrup as claimed in claim 1 , wherein the macromolecular blocks are prepared from monomers chosen from:
the acrylic monomers of formula CH 2 ═CH—C(═O)—O—R 1 in which R 1 denotes a hydrogen atom or a linear, cyclic or branched C 1 -C 40 alkyl group optionally substituted with a halogen atom or a hydroxyl, alkoxy, cyano, amino or epoxy group,
the methacrylic monomers of formula CH 2 ═C(CH 3 )—C(═O)—O—R 2 in which R 2 denotes a hydrogen atom or a linear, cyclic or branched C 1 -C 40 alkyl group optionally substituted with a halogen atom or a hydroxyl, alkoxy, cyano, amino or epoxy group, and
vinylaromatic monomers.

3. The liquid (meth)acrylic impregnation syrup as claimed in claim 1 , wherein the macromolecular blocks of flexible nature comprise butyl acrylate to at least 70% by mass.

4. The liquid (meth)acrylic impregnation syrup as claimed in claim 1 , wherein the macromolecular blocks are prepared from butyl acrylate and styrene in a butyl acrylate/styrene mass ratio of between 70/30 and 90/10.

5. The liquid (meth)acrylic impregnation syrup as claimed in claim 1 , wherein the block copolymers are obtained by controlled radical polymerization (CRP) or by anionic polymerization.

6. The liquid (meth)acrylic impregnation syrup as claimed in claim 1 , wherein the macromolecular blocks are prepared by mixing with the monomer(s) intended to form the macromolecular blocks, an alkoxyamine of general formula Z(-T) n in which Z denotes a multivalent group, T a nitroxide and n is an integer greater than or equal to 2.

7. The liquid (meth)acrylic impregnation syrup as claimed in claim 6 , wherein the alkoxyamine corresponds to the following formula:

SG1 being N-tert-butyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide.

8. The liquid (meth)acrylic impregnation syrup as claimed in claim 6 , wherein the alkoxyamine corresponds to the following formula:

SG1 being N-tert-butyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide.

9. The liquid (meth)acrylic impregnation syrup as claimed in claim 1 , wherein the (meth)acrylic polymer is a homo- or copolymer of methyl methacrylate (MMA) or a mixture thereof.

10. The liquid (meth)acrylic impregnation syrup as claimed in claim 9 , wherein the copolymer of methyl methacrylate (MMA) comprises at least 70% by weight of methyl methacrylate (MMA).

11. The liquid (meth)acrylic impregnation syrup as claimed claim 9 , wherein the copolymer of methyl methacrylate (MMA) comprises from 70% to 99.7% by weight of methyl methacrylate and from 0.3 to 30% by weight of at least one monomer bearing at least one ethylenic unsaturation that can copolymerize with methyl methacrylate.

12. The liquid (meth)acrylic syrup as claimed in claim 9 , wherein the (meth)acrylic polymer comprises comonomer units, said comonomer being an alkyl acrylate containing an alkyl group of 1 to 12 carbon atoms.

13. The liquid (meth)acrylic syrup as claimed in claim 12 , wherein the comonomer is chosen from methyl acrylate and ethyl acrylate, and a mixture thereof.

14. The liquid (meth)acrylic syrup as claimed in claim 1 , wherein the (meth)acrylic monomer is chosen from acrylic acid, methacrylic acid, alkyl acrylic monomers and alkyl methacrylic monomers, and mixtures thereof, the alkyl group containing from 1 to 22 linear, branched or cyclic carbons.

15. The liquid (meth)acrylic syrup as claimed in claim 14 , wherein the (meth)acrylic monomer is chosen from methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, methacrylic acid, acrylic acid, n-butyl acrylate, isobutyl acrylate, n-butyl methacrylate, isobutyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate and isobornyl methacrylate, and mixtures thereof.

16. The liquid (meth)acrylic syrup as claimed in claim 14 , wherein the (meth)acrylic monomer is chosen from methyl methacrylate, isobornyl acrylate and acrylic acid, and mixtures thereof.

17. The liquid (meth)acrylic syrup as claimed in claim 14 wherein 50% by weight or more of the (meth)acrylic monomer is methyl methacrylate.

18. The liquid (meth)acrylic impregnation syrup as claimed in claim 1 wherein the (meth)acrylic polymer in the liquid (meth)acrylic syrup is present in a content of at least 1% by weight of the total liquid (meth)acrylic syrup.

19. The liquid (meth)acrylic impregnation syrup as claimed in claim 1 , wherein the (meth)acrylic polymer in the liquid (meth)acrylic syrup is present in a content of not more than 50% by weight of the total liquid (meth)acrylic syrup.

20. The liquid (meth)acrylic impregnation syrup as claimed in claim 1 , wherein the (meth)acrylic monomer in the liquid (meth)acrylic syrup is present in a content of at least 30% by weight of the total liquid (meth)acrylic syrup.

21. The liquid (meth)acrylic impregnation syrup as claimed in claim 1 , wherein said syrup comprises:
a) from 10% by weight to 30% by weight of a (meth)acrylic polymer,
b) from 30% by weight to 89% by weight of a (meth)acrylic monomer,
c) from 5% by weight to 15% by weight of macromolecular blocks.

22. A process for manufacturing a liquid (meth)acrylic impregnation syrup as claimed in claim 1 , wherein said process it comprises the following steps:
1. preparing macromolecular blocks by mixing with the monomer(s), intended to form the macromolecular blocks, an alkoxyamine of general formula Z(-T) n in which Z denotes a multivalent group, T a nitroxide and n is an integer greater than or equal to 2,
2. mixing the macromolecular blocks obtained in step 1 with a (meth)acrylic polymer and a (meth)acrylic monomer.

23. An impregnation process for impregnating a fibrous substrate, said fibrous substrate consisting of long fibers and said process comprising a step of impregnating said fibrous substrate with said (meth)acrylic syrup as claimed in claim 1 .

24. The impregnation process as claimed in claim 23 , wherein the step of impregnating said fibrous substrate is performed in a closed mold.

25. A polymeric composite material comprising a thermoplastic (meth)acrylic matrix and a fibrous substrate used as reinforcement, in which the fibrous substrate consists of long fibers, said composite material being characterized in that the thermoplastic (meth)acrylic matrix is obtained after polymerization of said fibrous substrate preimpregnated with said liquid (meth)acrylic syrup as claimed in claim 1 .

26. A pro

Assignees

• Arkema France

Inventors

• Gerard Pierre

Classifications

• C08J2333/12

  Homopolymers or copolymers of methyl methacrylate · CPC title

• C08L33/08

  Homopolymers or copolymers of acrylic acid esters · CPC title

• C08F2438/02

  Stable Free Radical Polymerisation [SFRP]; Nitroxide Mediated Polymerisation [NMP] for, e.g. using 2,2,6,6-tetramethylpiperidine-1-oxyl [TEMPO] · CPC title

• D06M15/263

  of unsaturated carboxylic acids; Salts or esters thereof · CPC title

• D06M13/203

  Unsaturated carboxylic acids; Anhydrides, halides or salts thereof · CPC title