The invention claimed is:
1. A multilayer composition for manufacturing mechanical or structured parts or articles comprising
a) a surface layer comprising a thermoplastic polymer A, and
b) a substrate layer comprising a polymeric composite material
wherein said polymeric composite material comprises a polymeric thermoplastic (meth)acrylic matrix selected from the group consisting of a homopolymer or copolymer of methyl(meth)acrylate comprising at least 70% by weight of methyl(meth)acrylate and mixtures thereof, and a fibrous material as reinforcement, wherein the fibrous material comprises discontinuance fibers and wherein said polymeric composite material is formed by the impregnation of said fibrous material with a (meth)acrylic syrup comprising a methyl methacrylate polymer having a weight average molecular weight of greater than 100,000 g/mol, dissolved in a (meth)acrylic monomer wherein said (meth)acrylic monomer comprises methyl methacrylate monomer, followed by polymerization of said (meth)acrylic syrup, wherein said (meth)acrylic syrup has a dynamic viscosity at 25° C. between 10 mPa*s and 10000 mPa*s, and wherein said (meth)acrylic syrup comprises the (meth)acrylic monomer or a mixture of the (meth)acrylic monomers, the methyl methacrylate polymer and at least one initiator or initiating system for starting the polymerization of the (meth)acrylic monomer, wherein said (meth)acrylic syrup forms the polymeric thermoplastic (meth)acrylic matrix,
wherein said impregnation of said fibrous material is made in a closed mold, and wherein said surface layer has a thickness of less than 10 mm.
2. The multilayer composition according to claim 1 wherein said multilayer composition further comprises an intermediate layer between the surface layer and the substrate layer, said intermediate layer comprises a thermoplastic polymer B.
3. The multilayer composition according to claim 1 wherein said thermoplastic polymer A is selected from the group consisting of:
(meth)acrylic polymers;
saturated polyester;
polyethylene terephthalate, polybutylene terephthalate, polylactic acid; ABS (acrylonitrile-butadiene-styrene copolymer);
SAN (styrene-acrylonitrile copolymer);
ASA (acrylic-styrene-acrylonitrile copolymer);
Polystyrene, crystalline polystyrene, high impact polystyrene;
polypropylene (PP);
polyethylene (PE);
polycarbonate (PC);
PPO;
polysulfone;
PVC (polyvinylchloride);
PVDF (polyvinylidene fluoride)
chlorinated PVC (PVCC);
PU (polyurethane)
and mixtures thereof.
4. The multilayer composition according to claim 2 wherein said thermoplastic polymer B is selected from the group consisting of
(meth)acrylic polymers
saturated polyester, polyethylene terephthalate, polybutylene terephthalate, polylactic acid;
ABS (acrylonitrile-butadiene-styrene copolymer);
SAN (styrene-acrylonitrile copolymer);
ASA (acrylic-styrene-acrylonitrile copolymer);
Polystyrene, crystalline polystyrene, high impact polystyrene;
polypropylene (PP);
polyethylene (PE);
polycarbonate (PC);
PPO;
polysulfone;
PVC (polyvinylchloride);
PVDF (polyvinylidene fluoride)
chlorinated PVC (PVCC);
PU (polyurethane)
and mixtures thereof.
5. The multilayer composition according to claim 1 , wherein said thermoplastic polymer A is selected from the group consisting of:
(meth)acrylic polymers;
ASA (acrylic-styrene-acrylonitrile copolymer);
polycarbonate (PC);
PVDF (polyvinylidene fluoride)
and mixtures thereof.
6. The multilayer composition according to claim 1 wherein said thermoplastic polymer A is selected from (meth)acrylic polymers.
7. The multilayer composition according to claim 2 wherein said thermoplastic polymer B is selected from the group consisting of:
(meth)acrylic polymers;
ABS (acrylonitrile-butadiene-styrene copolymer);
ASA (acrylic-styrene-acrylonitrile copolymer);
polycarbonate (PC);
PVDF (polyvinylidene fluoride)
and mixtures thereof.
8. The multilayer composition according to claim 2 , wherein said thermoplastic polymer B is an acrylonitrile-butadiene-styrene copolymer.
9. The multilayer composition according to claim 1 wherein said thermoplastic (meth)acrylic matrix is a methyl methacrylate (MMA) homopolymer or a copolymer comprising at least 70%, by weight of methyl methacrylate.
10. The multilayer composition according to claim 1 wherein said fibrous material is selected from the group consisting of vegetable fibers, wood fibers, animal fibers, mineral fibers, synthetic polymeric fibers, glass fibers, carbon fibers and mixtures thereof.
11. A manufacturing process for a multilayer composition for mechanical or structured parts or articles according to claim 1 comprising one of the following sets of steps A or B:
A a) thermoforming the surface layer comprising the thermoplastic polymer A,
b) positioning a fibrous substrate on one side of the thermoformed surface layer,
c) impregnating the fibrous substrate with a liquid (meth)acrylic syrup, and
d) polymerising the liquid (meth)acrylic syrup impregnating said fibrous substrate,
B a) impregnating a fibrous substrate with a liquid (meth)acrylic syrup,
b) polymerising the liquid (meth)acrylic syrup impregnating said fibrous substrate, and
c) laminating the surface layer comprising a thermoplastic polymer A to at least one side of the layer obtained after the polymerization in step Bb).
12. The manufacturing process according to claim 11 , wherein said impregnation of the fibrous substrate is made in a closed mold.
13. The manufacturing process according to claim 11 , wherein said liquid (meth)acrylic syrup has a dynamic viscosity at 25° C. between 10 mPa*s and 10000 mPa*s.
14. The manufacturing process according to claim 11 , wherein said liquid (meth)acrylic syrup comprises a (meth)acrylic monomer or a mixture of a (meth)acrylic monomers, a (meth)acrylic polymer and at least one initiator or initiating system for starting the polymerization of the (meth)acrylic monomer.
15. The manufacturing process according to claim 14 , wherein said (meth)acrylic monomer or the (meth)acrylic monomers in the liquid (meth)acrylic syrup present at least 40% by weight.
16. The manufacturing process according to claim 14 , wherein said (meth)acrylic polymer or polymers in the liquid (meth)acrylic syrup present at least 10% by weight of total liquid (meth)acrylic syrup.
17. The manufacturing process according to claim 14 , wherein said (meth)acrylic polymer or polymers in the liquid (meth)acrylic syrup present at most 60% by weight of total liquid (meth)acrylic syrup.
18. The manufacturing process according to claim 11 , wherein said liquid (meth)acrylic syrup comprises
a) from 10 wt % to 59.99 wt % (meth)acrylic polymer,
b) from 40 wt % to 89.99 wt % (meth)acrylic monomer,
c) from 0.01 wt % to 5 wt % one initiator or initiating system for starting the polymerization of the (meth)acrylic monomer,
d) from 0 wt % to 1 wt % activator,
e) from 0 wt % to 20 wt % filler, and
f) from 0 wt to 20 wt % additives.
19. The manufacturing process according to claim 11 , wherein said process comprises resin transfer molding or infusion.
20. Three-dimensional mechanical or structured part obtained by the manufacturing process according to claim 11 .
21. Part according to claim 20 , wherein said part is a automobile part, boat part, train part, sport article, plane or helicopter part, space ship or rocket part, photovoltaic module part, wind turbine part, furniture part, cons