Polymeric composition for watercrafts, its use and watercraft comprising it

1. A watercraft or nautical object, a portion of which is transparent, comprising a polymeric composition PC 1 comprising a transparent polymer TP 1 , wherein the transparent polymer TP 1 is a (meth) acrylic block copolymer MBC, a (meth) acrylic polymer composition MP 1 , a crosslinked (meth) acrylic composition MCX, or blends thereof,

wherein the crosslinked (meth) acrylic composition MCX comprises:

a brittle matrix (I) having a glass transition temperature of greater than 0° C. and elastomeric domains having a dimension of less than 100 nm consisting of macromolecular sequences (II) having a flexible nature with a glass transition temperature of less than 0° C., wherein the macromolecular sequences (II) are flexible and have a weight average molecular weight Mw of between 200,000 and 650,000 g/mol;

wherein the (meth) acrylic block copolymer MBC comprises at least one block where at least 50 wt % of the monomers inside the block are alkyl (meth) acrylate monomers that have been polymerized;

wherein the macromolecular sequences comprise butyl acrylate and styrene in a ratio by weight of between 70/30 and 90/10, and wherein the nautical object is an object that floats on or in or under water.

2. The watercraft or nautical object according to claim 1 , wherein the transparent polymer TP 1 is a (meth)acrylic block copolymer MBC or a crosslinked (meth) acrylic composition MCX.

3. The watercraft or nautical object according to claim 1 , wherein the (meth) acrylic block copolymer MBC has a general formula (A) n B in which:

n is an integer of greater than or equal to 1,

A is an acrylic or methacrylic homo- or copolymer having a Tg of greater than 50° C., or polystyrene, or an acrylic/styrene or methacrylic/styrene copolymer;

B is an acrylic or methacrylic homo- or copolymer having a Tg of less than 20° C., comprising monomers selected from the group consisting of methyl acrylate, ethyl acrylate, butyl acrylate (BuA), ethylhexyl acrylate, styrene (Sty) and butyl methacrylate, where the monomers make up at least 50 wt % of B.

4. The watercraft or nautical object according to claim 1 , wherein the transparent polymer TP 1 is a (meth) acrylic block copolymer MBC that is a triblock copolymer.

5. The watercraft or nautical object according to claim 4 , wherein the triblock copolymer comprises one or more of pMMA·pBuA·pMMA, p(MMAcoMAA)-pBuA-p(MMAcoMAA), p(MMAcoMAA)·p(BuAcoSty)-p(MMAcoMAA) and p(MMAcoAA)-p(MMAcoAA).

6. The watercraft or nautical object according to according to claim 1 , wherein the polydispersity index of the molecular weight Mw/Mn of the macromolecular sequences (II) having a flexible nature is greater than 2.

7. The watercraft or nautical object according to according to claim 4 , wherein the polydispersity index of the molecular weight Mw/Mn of the macromolecular sequences (II) having a flexible nature is between 2.5 and 10.0.

8. The watercraft or nautical object according to claim 1 , a substantial portion of which is transparent, and where the transparent portion comprises the polymeric composition PC 1 .

9. The watercraft or nautical object according to claim 8 , wherein the & watercraft comprises a cavity ( 28 ).

10. The watercraft or nautical object according to claim 9 , wherein the cavity has a volume between 100 cm 3 and 100 m 3 .

11. The watercraft or nautical object according to claim 1 , wherein at least 10% of a surface of the watercraft or nautical object in contact with water is transparent.

12. The watercraft or nautical object according to claim 1 , wherein the nautical object is selected from the group consisting of a stand-up paddle, a surfboard, and a floating house.

13. A process for making a watercraft or nautical object that comprises a polymeric composition PC 1 , the polymeric composition PC 1 comprising a transparent polymer TP 1 , wherein the process comprises:

1) providing a polymeric composition PC 1 comprising a crosslinked (meth) acrylic composition comprising a brittle matrix (I) having a glass transition temperature of greater than 0° C. and of elastomeric domains having a characteristic dimension of less than 100 nm consisting of macromolecular sequences (II) having a flexible nature with a glass transition temperature of less than 0° C. wherein the macromolecular sequences

(II) having a flexible nature have a weight average molecular weight Mw of between 150,000 and 800,000 g/mol, said process comprising the steps of:

a) preparing the macromolecular sequences (II) by mixing, with the monomer(s) intended to form the macromolecular sequences (II), an alkoxyamine of general formula Z (-T) n, in which Z denotes a polyvalent group, T denotes a nitroxide and n is an integer greater than or equal to 1;

b) mixing the macromolecular sequences (II) of step a) with methyl methacrylate, and optionally a crosslinking agent, optionally at least one comonomer M and optionally at least one radical initiator;

c) mixing the composition comprising the macromolecular sequences (II) and methyl methacrylate with a crosslinking agent, optionally at least one comonomer M and at least one radical initiator, if it has not been done yet in step b);

d) casting the mixture obtained in the previous step in a mold and then heating it according to a temperature cycle in order to obtain a cast sheet, and

2) assembling polymeric composition PC 1 , wherein the transparent polymer TP 1 is a (meth) acrylic block copolymer MBC, a (meth) acrylic polymer composition MP 1 , a crosslinked (meth)acrylic composition MCX, or blends thereof, wherein the crosslinked (meth)acrylic composition MCX comprises:

a brittle matrix (I) having a glass transition temperature of greater than 0° C. and elastomeric domains having a dimension of less than 100 nm consisting of macromolecular sequences (II) having a flexible nature with a glass transition temperature of less than 0° C., wherein the macromolecular sequences (II) are flexible and have a weight average molecular weight Mw of between 200,000 and 650,000 g/mol;

wherein the (meth) acrylic block copolymer MBC comprises at least one block where at least 50 wt % of the monomers inside the block are alkyl (meth) acrylate monomers that have been polymerized;

wherein the macromolecular sequences (II) comprise butyl acrylate and styrene in a ratio by weight of between 70/30 and 90/10, and wherein the nautical object is an object that floats on or in or under water.

14. The process according to claim 13 , wherein the transparent polymer TP 1 is a (meth) acrylic block copolymer MBC that is a triblock copolymer.

15. The process according to claim 2 , wherein the triblock copolymer comprises one or more of pMMA-pBuA-pMMA, p(MMAcoMAA)-pBuA-p(MMAcoMAA), p(MMAcoMMA)-p(BuAcoSty)-p(MMAcoMAA) and p(MMAcoAA)-pBuA-p(MMAcoAA).

16. The process according to claim 13 , wherein the process comprises an additional step of thermoforming the polymeric composition PC 1 .

17. The process according to claim 13 , wherein the polymeric composition PC 1 is provided in a form of a sheet having a thickness from 1 to 30 mm.

18. The process according to claim 13 , wherein the assembling step of the polymeric composition PC comprises bonding with an adhesive or by welding or by thermo compressing.