TECHNICAL FIELD

The present invention relates to a polyamide resin, a molded body containing the polyamide resin, a laminate provided with a film or a sheet containing the polyamide resin, a medical device provided with at least one of the molded body and the laminate, an a method for producing the polyamide resin.

BACKGROUND ART

Polyamide resin like polyamide elastomer is a resin compound that is widely used in various fields such as packaging materials for food and the like, members for medical devices, members for electric/precision machine devices, and members for automobiles. Among them, the members for medical devices are used as a constitutional member such as medical tube or catheter balloon. For a use in such members for medical devices, the polyamide elastomer is required to have moldability such as extrusion moldability and blow moldability, which enables fine molding into a desired shape, and dynamic characteristics such as elasticity, breaking elongation, and breaking strength, which enable withstanding of destruction caused by pressure or bending applied during use.

Patent Document 1 discloses a block polyether amide that is obtained by condensation polymerization of a certain polyamide having a carboxyl group on both ends, polyoxyalkylene having an amino group on both ends and having an alkylene group containing 3 or more carbon atoms, and a certain diamine. Furthermore, Patent Document 2 discloses polyether amide that is obtained by polycondensation of a polyamide-forming monomer, polyoxyalkylene having an amino group on both ends and having an alkylene group containing 3 or more carbon atoms, certain diamine, and certain amount of dicarboxylic acid. The polyether amides described in Patent Documents 1 and 2 are considered to have a certain degree of elasticity and impact resistance. However, with regard to the polyether amides with the component constitution described in Patent Documents 1 and 2, even with a use of the polyether having an alkylene group containing 3 or more carbon atoms, mechanical strength such as elasticity, breaking elongation, and breaking strength is insufficient, and thus further improvement has been demanded.

Patent Document 3 discloses a polyamide elastomer that is obtained by polymerization of (A) a polyamide-forming monomer selected from certain aminocarboxylic acid compounds and certain lactam compounds, (B) at least one diamine compound selected from polyether diamines having a polytetramethylene oxide (PTMO) skeleton, branched diamines, branched alicyclic diamines, and norbornane diamines, and (C) a certain dicarboxylic acid compound. The diamine compounds used in the invention described in Patent Document 3, however, have insufficient reactivity and require a long period of time for polymerization. This may cause thermal degradation of part of the polymerization product during polymerization, coloration of an elastomer to be obtained, or insufficient progress of the reaction, and thus yielding a problem like insufficient strength like breaking elongation and breaking strength of the obtained elastomer.

Patent Document 4 discloses a polyether polyamide copolymer resin that has a breaking elongation of 1000% or higher and a modulus of elasticity of 15 MPa or lower and is for use in coating of or impregnation into flexible woven fabric. Furthermore, as a specific constitution, a polyether polyamide resin that is obtained by binding between a soft segment consisting of polyether polyamide that is composed of a polyether diamine compound having an alkylene group with carbon atom number of 2 to 3 and a certain dicarboxylic acid compound, and a hard segment consisting of polyamide that is composed of a certain aminocarboxylic acid and/or a certain lactam compound is disclosed. However, the polyether polyamide resin described in Patent Document 4 has a problem that the polyether compound has poor reactivity and breaking strength of the resin is insufficient.Patent Document 1: Japanese Unexamined Patent Application, Publication No. S59-193923Patent Document 2: Japanese Unexamined Patent Application, Publication No. S59-131628Patent Document 3: PCT International Publication No. WO2007/145324Patent Document 4: PCT International Publication No. WO2009/139087

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

In consideration of the above problems, an object of the present invention is to provide a polyamide resin having excellent balance of mechanical characteristics such as breaking strength and breaking elongation in a solid state, a molded body containing the polyamide resin, a laminate provided with a film or a sheet containing the polyamide resin, a medical device provided with at least one of the molded body and the laminate, and a method for producing the polyamide resin.

Means for Solving the Problems

The inventors of the present invention conducted intensive studies to solve the problems described above, and, as a result, completed the present invention. Namely, the present invention relates to a polyamide resin according to [1] to [10] below, a molded body of [11] and [12] below, a laminate of [13] below, a medical device of [14] below, and a method for producing a polyamide resin of [15] and [16] below.

[1] A polyamide resin containing:

a unit (a);

a unit (b);

a unit (c) and/or a unit (d); and

a unit (e),

in which the unit (a) is a unit represented by the following formula (A):
—CO—R1(—NH—CO—R1)m—NH—  (A)
(in the formula (A), R1is, independently, a linear saturated hydrocarbon group having 6 or more and 18 or less carbon atoms, m is an integer of 0 or more and 100 or less, and, when m is an integer of 1 or more, a plurality of R1may be the same or different from each other),
the unit (b) is a unit represented by the following formula (B):
—CO—R2—CO—  (B)
(in the formula (B), R2is a single bond or a linear saturated hydrocarbon group having 1 or more and 20 or less carbon atoms),
the unit (c) is a unit represented by the following formula (C):
—NH—R3—NH—  (C)
(in the formula (C), R3is a saturated hydrocarbon group having 2 or more and 12 or less carbon atoms),
the unit (d) is a unit represented by the following formula (D):
—NH—(CH(CH3)CH2O—)x—(CH2CH2O—)y—(CH(CH3)CH2O—)z—CH2CH(CH3)—NH—  (D)
(in the formula (D), x+z is an integer of 1 or more and 6 or less and y is an integer of 1 or more and 20 or less), the unit (e) is a unit represented by the following formula (E):


(in the formula (E), R4is a hydrocarbon group which may contain, as a hetero atom, one or more selected from N, O, and S, and A is, independently, a carbonyl group (—CO—) or an amino group (—NH—)),
a total content of the unit (a), the unit (b), the unit (c), the unit (d), and the unit (e) in the polyamide resin is 90% by mass or more, and
a ratio between carbonyl terminal group molar amount (Ac) and amino terminal group molar amount (Aa) in whole units constituting the polyamide resin is 80/100 to 100/80 in terms of Ac/Aa.

[2] The polyamide resin described in [1], in which content of the unit (e) in the polyamide resin is 0.1% by mass or more but less than 4% by mass.

[3] The polyamide resin described in [1] or [2], in which a molecular weight of the unit (e) is 50 or more but less than 1,000.

[4] The polyamide resin described in any one of [1] to [3], in which the unit (e) is one or more selected from a unit represented by the following formula (E-1):


and a unit represented by the following formula (E-2)


(in the formula (E-2), R5is a hydrogen atom or an aliphatic hydrocarbon group having 1 or more and 5 or less carbon atoms, s is an integer of 0 or more and 3 or less, p, q, and r are an integer of 0 or more and 5 or less, and, p+q+r is an integer of 3 or more and 15 or less).

[5] The polyamide resin described in any one of [1] to [4], in which a number average molecular weight is 10,000 or more and 150,000 or less.

[6] The polyamide resin described in any one of [1] to [5], in which, with regard to the unit (c), R3in the formula (C) is one or more selected from an ethane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, a hexane-1,6-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a 2,2,4-trimethylhexane-1,6-diyl group, and a 2,4,4-trimethylhexane-1,6-diyl group.

[7] The polyamide resin described in any one of [1] to [6], in which, when a mole number of the unit (a) is Ma and a mole number of the unit (b) is Mb in whole units constituting the polyamide resin, a ratio Ma/Mb is 95/100 to 100/95.

[8] The polyamide resin described in any one of [1] to [7], in which a content of the unit (a) is 50 to 97.9% by mass, a content of the unit (b) is 1 to 20% by mass, and a content of the unit (c) is 1 to 10% by mass.

[9] The polyamide resin described in any one of [1] to [8], in which a content of the unit (a) is 50 to 97.9% by mass, a content of the unit (b) is 1 to 20% by mass, and a content of the unit (d) is 1 to 10% by mass.

[10] The polyamide resin described in any one of [1] to [9], in which a Shore hardness is 50 to 100, a breaking elongation is 100% or more and 600% or less, and a breaking stress is 20 MPa or more and 100 MPa or less.

[11] A molded body formed of a material containing the polyamide resin described in any one of [1] to [10].

[12] The molded body described in [11], in which the molded body is a film, a sheet, a tube, a powder, a fiber, a woven fabric, a non-woven fabric, or a catheter balloon.

[13] A laminate containing the film or the sheet described in [12].

[14] A medical device provided with at least one selected from the group consisting of the molded body described in [12] and the laminate described in [13].

[15] A method for producing the polyamide resin described in [1] including (i) reacting aminocarboxylic acid (a1) represented by the following formula (A1):
HOOC—R1(—NH—CO—R1)m—NH2—  (A1)
(in the formula (A1), R1is, independently, a linear saturated hydrocarbon group having 6 or more and 18 or less carbon atoms, m is an integer of 0 or more and 100 or less, and, when m is an integer of 1 or more, a plurality of R1may be the same or different from each other)
or an amide-forming derivative thereof with dicarboxylic acid (b1) represented by the following formula (B1):
HOOC—R2—COOH  (B1)
(in the formula (B1), R2is a single bond or a linear saturated hydrocarbon group having 1 or more and 20 or less carbon atoms)
or an amide-forming derivative thereof to obtain a prepolymer; and
(ii) reacting the prepolymer with one or more diamine selected from the group consisting of diamine (c1) represented by the following formula (C1):
H2N—R3—NH2(C1)
(in the formula (C1), R3is a saturated hydrocarbon group having 2 or more and 12 or less carbon atoms), and diamine (d1) represented by the following formula (D1):
H2N—(CH(CH3)CH2O—)x—(CH2CH2O—)y—(CH(CH3)CH2O—)z—CH2CH(CH3)—NH2(D1),
(in the formula (D1), x+z is an integer of 1 or more, and y is an integer of 1 or more and 20 or less), and trifunctional compound (e1) represented by the following formula (E1):


(in the formula (E1), R4is a hydrocarbon group which may contain, as a hetero atom, one or more selected from N, O, and S, and A1is, independently, a carboxy group (—COOH) or an amino group (—NH2))
or an amide-forming derivative thereof to produce a polyamide resin.

[16] The method described in [15], in which the reaction for producing a prepolymer and the reaction for producing a polyamide resin are carried out by a melt kneading method.

Effects of the Invention

According to the present invention, a polyamide resin having excellent balance of mechanical characteristics such as breaking strength and breaking elongation in a solid state, a molded body containing the polyamide resin, a laminate provided with a film or a sheet containing the polyamide resin, a medical device provided with at least one of the molded body and the laminate, and a method for producing the polyamide resin can be provided.

