TECHNICAL FIELD
[0001]
The present invention relates to a resin composition
containing 4-methyl-1-pentene copolymers and a molded article,
such as a film for capacitors, including the resin
10 composition.
BACKGROUND ART
[0002]
4-Methyl-1-pentene polymers are superior to polyethylene
15 and polypropylene in terms of properties such as heat
resistance, transparency, and electrical properties, and are
thus widely used in a variety of applications. Specifically,
a film for capacitors composed of a 4-methyl-1-pentene
copolymer is known.
20 [0003]
Patent Document 1 describes a 4-methyl-1-pentene
(co)polymer composition in which a 4-methyl-1-pentene
(co)polymer and a 4-methyl-1-pentene-α-olefin copolymer are
mixed in a particular ratio, and describes that a hollow
SF-3754
2
molded article composed of such a composition has excellent
transparency, heat resistance, electrical properties,
mechanical properties, uniform stretchability, and
dimensional stability.
5 [0004]
Patent Document 2 describes that a film for capacitors
obtained from a 4-methyl-1-pentene copolymer with particular
physical properties has electrical properties such that the
decreasing rate of electrostatic capacitance is small and
10 dielectric loss properties are stable at a high temperature
and under a long-term charge.
[0005]
Patent Document 3 describes that a 4-methyl-1-pentene
copolymer composition including a particular 4-methyl-1-
15 pentene (co)polymer and a 4-methyl-1-pentene copolymer (B)
has high impact resistance while possessing transparency and
rigidity, and also has high heat resistance.
[0006]
Patent Document 4 describes that a particular 4-methyl20 1-pentene polymer particle can reduce its rigidity, that is,
improve its flexibility, without sacrificing properties such
as high stereoregularity and excellent heat resistance.
CITATION LIST
SF-3754
3
PATENT DOCUMENTS
[0007]
Patent Document 1: WO 2013/099876
Patent Document 2: JP-A-2014-11182
5 Patent Document 3: JP-A-2018-162408
Patent Document 4: WO 2019/198694
SUMMARY OF INVENTION
TECHNICAL PROBLEM
10 [0008]
Films for capacitors need to prevent strong blocking
between the films in order to properly operate the security
function, and the surface roughness thereof are required to
be controlled properly. In addition, films for capacitors
15 have problems such as worsening of dielectric properties and
shortening of service life if the surface roughness is too
rough.
[0009]
With the 4-methyl-1-pentene copolymers and other
20 materials described in the above Patent Documents, it was not
possible to obtain a film that satisfies both the properties
applicable to capacitors (for example, electrical properties,
heat resistance, and stretchability) and the need to suppress
surface roughness to a small degree.

CLAIMS
1. A resin composition comprising a 4-methyl-1-pentene
5 copolymer (A) that satisfies the following requirements (A-a)
to (A-d) and a 4-methyl-1-pentene copolymer (B) that
satisfies the following requirements (B-a) to (B-d),
wherein the resin composition satisfies the following
requirements (1) and (2):
10 (A-a) in the copolymer (A), an amount (U1) of
constitutional units derived from 4-methyl-1-pentene is 80.0
to 99.9% by mol and a total amount (U2) of constitutional
units derived from at least one selected from linear αolefins having 2 to 20 carbon atoms is 20.0 to 0.1% by mol
15 (provided that U1 and U2 in total is 100% by mol);
(A-b) an intrinsic viscosity [η]A measured in decalin of
135°C of the copolymer (A) is 0.5 to 5.0 dL/g;
(A-c) when the copolymer (A) is measured in a cross
fractionation chromatograph apparatus (CFC) using an infrared
20 spectrophotometer as a detector part, at least one peak of an
amount of a component eluted is present in a range of 100 to
140°C;
(A-d) when the copolymer (A) is measured in the CFC, a
molecular weight distribution (Mw/Mn), which is a ratio
SF-3754
86
between a weight average molecular weight (Mw) and a number
average molecular weight (Mn), in the component eluted in a
range of 100 to 140°C is 1.0 to 4.5;
(B-a) in the copolymer (B), an amount (U3) of
5 constitutional units derived from 4-methyl-1-pentene is 20.0
to 98.0% by mol and a total amount (U4) of constitutional
units derived from at least one selected from linear αolefins having 2 to 20 carbon atoms is 80.0 to 2.0% by mol
(provided that U3 and U4 in total is 100% by mol);
10 (B-b) an intrinsic viscosity [η]B measured in decalin of
135°C of the copolymer (B) is 2.0 to 8.0 dL/g;
(B-c) when the copolymer (B) is measured in a cross
fractionation chromatograph apparatus (CFC) using an infrared
spectrophotometer as a detector part, at least one peak of an
15 amount of a component eluted is present in a range of 0°C or
higher and lower than 100°C;
(B-d) when the copolymer (B) is measured in the CFC, a
molecular weight distribution (Mw/Mn), which is a ratio
between a weight average molecular weight (Mw) and a number
20 average molecular weight (Mn), in the component eluted in a
range of 0°C or higher and lower than 100°C is 1.0 to 7.0;
(1) a content of the copolymer (A) is 5 to 95 parts by
mass and a content of the copolymer (B) is 95 to 5 parts by
SF-3754
87
mass with respect to 100 parts by mass of the total content
of the copolymers (A) and (B); and
(2) a value (U4 - U2) obtained by subtracting U2 (% by
mol) described in the requirement (A-a) from U4 (% by mol)
5 described in the requirement (B-a) is 0% by mol or more and
6.5% by mol or less.
2. The resin composition according to claim 1, wherein the
content of the copolymer (A) is 5 parts by mass or more and
10 less than 50 parts by mass and the content of the copolymer
(B) is greater than 50 parts by mass and 95 parts by mass or
less with respect to 100 parts by mass of the total content
of the copolymers (A) and (B).
15 3. The resin composition according to claim 1 or 2, wherein
the linear α-olefins in the copolymers (A) and (B) are each
independently a linear α-olefin having 10 to 20 carbon atoms.
4. A molded article comprising the resin composition
20 according to any one of claims 1 to 3.
5. A film comprising the resin composition according to any
one of claims 1 to 3.
SF-3754
88
6. A film satisfying the following requirements (I) to
(III):
(I) at least two 4-methyl-1-pentene copolymers are
contained;
5 (II) a surface roughness (Ra) of the film is less than
100 nm; and
(III) a surface roughness (Rz) of the film is less than
500 nm.
10 7. The film according to claim 5 or 6, wherein the film is
a film for capacitors.