Laminate
To provide a laminate which is formed from resins and is excellent in heat resistance and excellent in flexibility and mechanical properties under high-temperature conditions and which undergoes no separation of layers even when contacted with oil such as engine oil for a long period of time. The laminate comprises a first layer containing a fluorinated copolymer and a second layer containing a polyamide directly laminated on the first layer, wherein the fluorinated copolymer has units based on tetrafluoroethylene, units based on ethylene, units based on a copolymerizable another monomer not having a carbonyl group, and carbonyl group-containing groups, wherein the amounts of the respective units are in specific ranges, and the tensile elongation at 200° C. of the fluorinated copolymer is at least 200%, and the melting point of the polyamide and the flexural elastic modulus at 23° C. of the second layer are in specific ranges.
1. A laminate, comprising:
a first layer containing a fluorinated copolymer and
a second layer containing a polyamide directly laminated on the first layer,
wherein
the fluorinated copolymer contains:
units (a1) based on tetrafluoroethylene,
units (a2) based on ethylene,
units (a3) based on a monomer which is a copolymerizable monomer having no carbonyl group-containing group and at least a portion of which is represented by CH 2 ═CX(CF 2 ) n Y, where X and Y are each independently a hydrogen atom or a fluorine atom and n is an integer of 4, and
carbonyl group-containing groups;
a molar ratio of the units (a1) to a sum of the units (a1) and the units (a2) ranges from 0.510 to 0.600;
a molar ratio of the units (a3) to the sum of the units (a1) and the units (a2) ranges from 0.005 to 0.030;
a proportion of a total molar amount of the units (a1), the units (a2), and the units (a3) to a total molar amount of all units contained in the fluorinated copolymer is at least 90 mol %;
the fluorinated copolymer has a melting point of at least 250° C., a tensile strength at 200° C. of at least 4.5 MPa, and a tensile elongation at 200° C. of at least 400%;
the polyamide has a melting point of at least 220° C. and is a copolyamide containing:
from 40 to 75 mol % of polyamide units (b1) based on at least one type of semi-aromatic units containing units of at least one type derived from an aromatic dicarboxylic acid and units of at least one type derived from a C 9-13 aliphatic diamine,
from 20 to 50 mol % of polyamide units (b2) based on at least one type of aliphatic units having 8 to 13 carbon atoms per one nitrogen atom, and
from 0 to 20 mol % of polyamide units (b3) other than the polyamide units (b1) and (b2); and
the second layer has a flexural modulus at 23° C. of at most 1200 MPa.
2. The laminate according to claim 1 , wherein a number of carbonyl group-containing groups in the fluorinated copolymer is from 10 to 60,000 to a number of 1×10 6 carbon atoms in the main chain of the fluorinated copolymer.
3. The laminate according to claim 1 , wherein the carbonyl-containing groups are at least one type selected from the group consisting of a group having a carbonyl group between carbon atoms of a hydrocarbon group, a carbonate group, a carboxy group, a haloformyl group, an alkoxycarbonyl group and an acid anhydride residue.
4. The laminate according to claim 1 , wherein the carbonyl-containing groups are acid anhydride residues.
5. The laminate according to claim 1 , wherein the fluorinated copolymer further contains:
units (a4) based on a monomer having a carbonyl group-containing group.
6. The laminate according to claim 5 , wherein the units (a4) are units based on a non-fluorinated monomer having an acid anhydride residue.
7. The laminate according to claim 1 , wherein X is a hydrogen atom, and Y is a fluorine atom.
8. The laminate according to claim 1 , wherein the second layer further contains an impact resistance improver.
9. The laminate according to claim 8 , wherein a content of the impact resistance improver in the second layer ranges from 5 to 90 parts by mass per 100 parts by mass of the polyamide.
10. The laminate according to claim 1 , which has a tensile strength at 200° C. of at least 2.0 MPa.
11. The laminate according to claim 1 , which has a tensile elongation at 200° C. of at least 100%.
12. The laminate according to claim 1 , which is a laminated hose.
13. The laminate according to claim 12 , which is an air hose for transportation equipment.
14. The laminate according to claim 1 , wherein a total molar amount of the polyamide units (b1) and (b2) to a total molar amount of all units contained in the polyamide is at least 80 mol %.
15. The laminate according to claim 1 , wherein
the polyamide contains the polyamide units (b3) and
a molar amount of the polyamide units (b3) is at most 10 mol % relative to a total molar amount of all units contained in the polyamide.
16. The laminate according to claim 1 , wherein the polyamide units (b2) do not include a cyclic hydrocarbon.
17. The laminate according to claim 1 , wherein the molar ratio of the units (a3) to the sum of the units (a1) and the units (a2) ranges from 0.007 to 0.020.