JP7603367B2 - Resin composition, production method, and molded article thereof - Google Patents

Description

The present invention relates to a resin composition that exhibits good moldability during extrusion molding, a method for producing the same, and a molded article obtained by the molding method.

Traditionally, thermoplastic resins have been used for various applications as films, sheets, fibers, and other molded articles by extrusion molding. In order to obtain molded articles with good mechanical properties by extrusion molding, it is common to use resins with low MFR. However, resins with low MFR cause many problems in moldability, such as poor engagement with the screw in the extruder, poor melting of the resin, unstable discharge rate due to high extrusion torque, and limited extrusion speed. In addition, the above problems occur depending on the variations in the physical properties and shape of the resin, the specifications of the extruder, etc., so in recent years, there has been an even stronger demand for improved moldability to solve such problems.

A commonly known method for improving moldability during extrusion molding is to add a molding aid to the resin before molding. For example, methods have been considered in which a molding aid such as oil or polyethylene wax is added to the thermoplastic resin to be molded (see, for example, Patent Documents 1 and 2).

However, even if resins such as polypropylene are extruded using conventional molding aids, the moldability itself tends to improve, but the mechanical properties of the resulting molded product usually decrease. Therefore, even if the molded product obtained by extrusion molding using conventional molding aids is used as a film, sheet, fiber, or other molded product, problems may arise depending on the application.

Furthermore, when conventional molding aids are added by feeding them into an extruder from a hopper together with the thermoplastic resin, the molding aids can cause slippage in the extruder, inhibiting the melting of the thermoplastic resin and in some cases reducing moldability.

Special Publication No. 5-80492 Special Publication No. 2003-528948

The object of the present invention is to provide a resin composition that has excellent moldability without causing a decrease in moldability due to slippage in the extruder during extrusion molding, and that does not impair the mechanical properties of the molded article obtained by extrusion molding, a method for producing the same, and a molded article obtained from the resin composition.

The present invention relates to the following items [1] to [6].
[1] A resin composition containing 25 to 99.99 mass% of a thermoplastic resin (A) having a polystyrene-equivalent weight average molecular weight (Mw) of 5,000 or more as measured by gel permeation chromatography (GPC), and 0.01 to 3.8 mass% of an α-olefin (co)polymer (B) satisfying the following requirements (b-1) to (b-4):
(b-1) The methyl group index measured from ¹ H-NMR is 25 to 60%. (Here, the methyl group index refers to the ratio of the integral value of a peak within the range of 0.50 to 1.15 ppm to the integral value of a peak within the range of 0.50 to 2.20 ppm when the α-olefin (co)polymer is dissolved in deuterochloroform and ¹ H-NMR is measured, and the solvent peak appearing at 7.24 ppm based on _CHCl 3 in deuterochloroform is used as a reference.)
(b-2) No melting point is observed in differential scanning calorimetry (DSC).
(b-3) The weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is from 1,000 to 20,000.
(b-4) The density measured by the pycnometer method is 810 to 870 kg/ ^m3 .
[2] The resin composition according to [1], wherein the thermoplastic resin (A) is a polyolefin.
[3] The resin composition according to [1] or [2], wherein the thermoplastic resin (A) is polypropylene.
[4] The resin composition according to any one of [1] to [3], wherein the proportion of components having a molecular weight of less than 5,000 as determined by gel permeation chromatography (GPC) is in the range of 0.7 to 4.5 mass% of all components.
[5] A method for producing the resin composition according to any one of [1] to [4], comprising the steps of kneading 0.1 to 100 parts by mass of the α-olefin (co)polymer (B) with 100 parts by mass of the thermoplastic resin (A) to obtain a master batch, and kneading the thermoplastic resin (A) and the master batch in an extruder.
[6] A molded article comprising the resin composition according to any one of [1] to [4].

The present invention provides a resin composition that has excellent moldability without causing a decrease in moldability due to slippage in the extruder during extrusion molding of a thermoplastic resin, and does not impair the mechanical properties of the molded article obtained by extrusion molding, a method for producing the same, and a molded article obtained from the resin composition.

The present invention will be described in detail below.
In the following description, the numerical range " ^N1 or more and ^{N2 or} less" ( ^N1 and ^N2 respectively indicate the lower and upper limits of the numerical range) may be simply referred to as " ^N1 to ^N2 ." For example, an α-olefin having 3 to 20 carbon atoms may be referred to as an "α-olefin having 3 to 20 carbon atoms."

The resin composition according to the present invention contains 25 to 99.99% by mass of a thermoplastic resin (A) having specific physical properties and 0.01 to 3.8% by mass of an α-olefin (co)polymer (B) having specific physical properties.

Thermoplastic resin (A)
The thermoplastic resin (A) used in the present invention is a thermoplastic polymer having a weight average molecular weight (Mw) of 5,000 or more in terms of polystyrene as measured by gel permeation chromatography (GPC), or a blend thereof.

The thermoplastic resin (A) used in the present invention is not particularly limited, and examples thereof include polyolefins such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, polybutene, cyclic olefin polymers, ethylene-propylene copolymers, and cyclic olefin copolymers; styrene-based polymers and hydrogenated products thereof such as polystyrene, acrylonitrile-styrene copolymers, acrylonitrile-butadiene-styrene copolymers, styrene-butadiene copolymers, and styrene-isoprene copolymers; polyvinyl chloride, polyvinylidene chloride; vinyl carboxylic acid polymers and vinyl carboxylic acid ester polymers such as polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polymethyl methacrylate, and polyethyl methacrylate; ethylene-methacrylic acid copolymers, ethylene-methacrylic acid ester copolymers, ethylene-vinyl acetate copolymers, and ethylene-vinyl alcohol copolymers; polycarbonates, polymethacrylates; polyesters such as polyethylene terephthalate and polybutylene terephthalate; nylon 6, nylon 11, nylon 12, nylon 46, nylon 66, and nylon M Examples include polyamides such as XD6, fully aromatic polyamides, and semi-aromatic polyamides; polyacetals, and blends of these resins.

Of these thermoplastic resins, polyolefins are preferred, with low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, and ethylene-propylene copolymers being more preferred, and polypropylene being particularly preferred.

When the thermoplastic resin (A) is the above-mentioned polyolefin, the compatibility between the thermoplastic resin (A) and the α-olefin (co)polymer (B) described below is particularly excellent, and a good resin composition can be obtained without deterioration of mechanical properties or bleeding out to the surface.

The MFR (JIS K 7210; 230° C., test load 2.16 kgf) of the polypropylene is preferably in the range of 0.1 to 60 g/10 min, more preferably in the range of 0.3 to 20 g/10 min, and particularly preferably in the range of 0.3 to 10 g/10 min.
When the MFR of the polypropylene is within the above range, a molded article having excellent mechanical properties, heat resistance, chemical resistance, etc. can be obtained.

<Content of Thermoplastic Resin (A)>
The content of the thermoplastic resin (A) in the entire resin composition of the present invention is 25 to 99.99 mass%, preferably 90 to 99.99 mass%, more preferably 96.2 to 99.8 mass%, particularly preferably 97 to 99.4 mass%, and more preferably 98 to 99.4 mass%.

If the content of thermoplastic resin (A) in the entire resin composition is less than the lower limit, the properties of thermoplastic resin (A) may be impaired, and a molded product having excellent mechanical properties, heat resistance, chemical resistance, etc. may not be obtained. On the other hand, if the content of thermoplastic resin (A) in the entire resin composition exceeds the upper limit, problems such as poor moldability, unstable discharge rate, and limited extrusion speed may occur.

α-Olefin (co)polymer (B)
The α-olefin (co)polymer (B) used in the present invention satisfies the requirements (b-1) to (b-4) described below. In the present invention, the α-olefin (co)polymer is preferably a homopolymer of an α-olefin having 2 to 20 carbon atoms or a copolymer of two or more α-olefins.

Examples of α-olefins having 2 to 20 carbon atoms constituting the α-olefin (co)polymer (B) of the present invention include linear α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tricene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, and 1-eicosene, and branched α-olefins such as 3-methyl-1-pentene, 4-methyl-1-pentene, 8-methyl-1-nonene, 7-methyl-1-decene, 6-methyl-1-undecene, and 6,8-dimethyl-1-decene. These α-olefins can be used alone or in combination of two or more.

Requirement (b-1)
The methyl group index measured by ^1H -NMR is 25 to 60% (here, the methyl group index refers to the ratio of the integral value of a peak within the range of 0.50 to 1.15 ppm to the integral value of a peak within the range of 0.50 to ^2.20 ppm when the α-olefin (co)polymer (B) is dissolved in deuterochloroform and 1H-NMR is measured, and the solvent peak appearing at 7.24 ppm based on _CHCl3 in deuterochloroform is used as a reference).

The α-olefin (co)polymer (B) according to the present invention is characterized in that the ratio of methyl groups to all protons is within a certain range. It is generally known that the protons of methyl groups are observed as peaks on the high magnetic field side in ¹ H-NMR measurement ("Polymer Analysis Handbook" (published by Asakura Publishing Co., Ltd., pp. 163-170)). For this reason, in the present application, the ratio of the peaks on the high magnetic field side observed in ¹ H-NMR measurement is used as the index of methyl groups. Specifically, α-olefin (co)polymer (B) is dissolved in deuterated chloroform and ¹ H-NMR is measured, and the ratio of the integral value of the peaks in the range of 0.50 to 1.15 ppm to the integral value of the peaks in the range of 0.50 to 2.20 ppm when the solvent peak based on CHCl ₃ in deuterated chloroform is used as the reference (7.24 ppm) is used as the methyl group index. Here, the peaks based on the α-olefin (co)polymer are almost included in the range of 0.50 to 2.20 ppm. Within this range, the peak due to the methyl group is likely to fall within the range of 0.50 to 1.15 ppm.

The α-olefin (co)polymer (B) according to the present invention has a methyl group index of 25 to 60%, with a preferred embodiment being 25 to 40% and another preferred embodiment being 40 to 60%. When the methyl group index is within the above range, the compatibility between the α-olefin (co)polymer (B) and the thermoplastic resin (A) is good, and the mechanical properties of the resin composition can be maintained. In particular, when the thermoplastic resin (A) is a polyolefin, the compatibility is excellent due to the similarity of structure, and the compatibility between the amorphous portion of the polyolefin and the α-olefin (co)polymer (B) in particular is excellent, which prevents bleed-out and maintains good mechanical properties and appearance. This is presumably because the methyl group index is an index that indicates the proportion of branches in the α-olefin (co)polymer (B), and when the methyl group index of the α-olefin (co)polymer (B) falls within the above range, a certain amount of branches present contribute to reducing the intermolecular forces of the α-olefin (co)polymer (B), allowing for good diffusion (compatibility) into the amorphous portion of the polyolefin.

The methyl group index in the α-olefin (co)polymer (B) according to the present invention can be controlled by selecting and polymerizing an appropriate α-olefin. For example, homopolymers of α-olefins having 3 to 5 carbon atoms, such as propylene, butene, and isobutene, have too high a ratio of methyl groups to the monomer, making it difficult to adjust the methyl group index within the above range. When attempting to achieve a methyl group index within the above range using a homopolymer, it is necessary to select an α-olefin having 6 to 20 carbon atoms as the α-olefin. A polymer that satisfies such requirements is a higher α-olefin (co)polymer (PAO), which is a preferred embodiment of the α-olefin (co)polymer in the present invention. Details of the higher α-olefin (co)polymer (PAO) will be described later. Also, for example, a homopolymer of ethylene does not have a methyl group, so it is necessary to appropriately copolymerize an α-olefin having 3 to 20 carbon atoms to increase the ratio of methyl groups. A polymer that satisfies such requirements is an ethylene-α-olefin copolymer, which is another preferred embodiment of the α-olefin (co)polymer in the present invention. Details of the higher α-olefin (co)polymer (PAO) will be described later. Also, for example, a homopolymer of ethylene does not have a methyl group, so it is necessary to increase the ratio of methyl groups. A polymer that satisfies such requirements is an ethylene-α-olefin copolymer, which is another preferred embodiment of the α-olefin (co)polymer in the present invention. Details of the higher α-olefin (co)polymer will be described later.

Requirement (b-2)
No melting point was observed in differential scanning calorimetry (DSC).
The α-olefin (co)polymer (B) according to the present invention is characterized in that no melting point is observed as measured by differential scanning calorimetry (DSC). Here, "no melting point (Tm) is observed" means that the heat of fusion (ΔH) (unit: J/g) measured by differential scanning calorimetry (DSC) is not substantially measured. "No heat of fusion (ΔH) is substantially measured" means that no peak is observed in differential scanning calorimetry (DSC) measurement, or the observed heat of fusion is 1 J/g or less.

The melting point (Tm) and heat of fusion (ΔH) of the α-olefin (co)polymer (B) according to the present invention are determined by analyzing the DSC curve with reference to JIS K7121 when the α-olefin (co)polymer (B) is cooled to -100°C and then heated to 150°C at a heating rate of 10°C/min after measurement with a differential scanning calorimeter (DSC). If the α-olefin (co)polymer (B) does not have an observed melting point, it is likely to become liquid at room temperature, and a good flowability improving effect can be obtained. In addition, when the α-olefin (co)polymer (B) is used as a master batch obtained by melt-kneading it with the above-mentioned thermoplastic resin (A) in advance, the α-olefin (co)polymer (B) is likely to soften and melt the thermoplastic resin (A) contained in the master batch, and a good flowability improving effect can be obtained, since the melting point of the α-olefin (co)polymer (B) is not observed.

In addition, when the thermoplastic resin (A) is a polyolefin, if the α-olefin (co)polymer (B) does not have a melting point, the α-olefin (co)polymer (B) will exhibit good compatibility with the amorphous portion of the thermoplastic resin (A), and not only will it prevent bleed-out and deterioration of mechanical properties, but it is also expected that the flexibility of the α-olefin (co)polymer (B) will have the effect of imparting good tensile elongation at break to the thermoplastic resin (A).

Requirement (b-3)
The weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 1,000 to 20,000.

The α-olefin (co)polymer (B) according to the present invention has a weight average molecular weight (Mw) in the range of 1,000 to 20,000, preferably 1,500 to 15,000, more preferably 2,000 to 9,000, and particularly preferably 2,000 to 5,500. If the weight average molecular weight is smaller than the lower limit, the mobility of the α-olefin (co)polymer (B) in the resin composition increases, and bleeding out is likely to occur. On the other hand, if the weight average molecular weight of the α-olefin (co)polymer (B) is larger than the upper limit, a sufficient flow improvement effect cannot be obtained, and moldability may not be improved, or compatibility with the thermoplastic resin (A) may be poor, causing a decrease in mechanical properties and bleeding out.

The molecular weight distribution (Mw/Mn) of the α-olefin (co)polymer (B) according to the present invention measured by gel permeation chromatography is not particularly limited, but is usually 3 or less, preferably 2.5 or less, and more preferably 2 or less. The molecular weight distribution (Mw/Mn) is usually 1.0 or more, and preferably 1.2 or more. If the molecular weight distribution of the α-olefin (co)polymer is broad (Mw/Mn is large), it will contain a large amount of low-molecular-weight or high-molecular-weight components that may cause bleed-out or deterioration of mechanical properties, which is not preferable.

The weight average molecular weight and molecular weight distribution of the α-olefin (co)polymer (B) according to the present invention can be measured by gel permeation chromatography (GPC) calibrated using a standard substance (monodisperse polystyrene) of known molecular weight.

Requirement (b-4)
The density measured by the pycnometer method is 810 to 870 kg/ ^m3 .
The α-olefin (co)polymer (B) according to the present invention has a density of 810 to 870 kg/m ³ , preferably 820 to 855 kg/m ³ , more preferably 830 to 850 kg/m ³ , and particularly preferably 840 to 850 kg/m ^3. When the density of the α-olefin (co)polymer (B) is within the above range, the α-olefin (co)polymer (B) has good compatibility with the thermoplastic resin (A), and the mechanical properties of the resin composition can be maintained. In particular, when the thermoplastic resin (A) is a polyolefin, the amorphous portion of the polyolefin and the α-olefin (co)polymer (B) show excellent compatibility, so that bleeding out of the resin composition can be prevented and the mechanical properties and appearance can be maintained well.

The density (Db) of the α-olefin (co)polymer (B) according to the present invention is preferably such that the difference (Da-Db) between the density (Da) of the thermoplastic resin (A) and the density (Da) of the α-olefin (co)polymer (B) is in the range of 10 to 160 kg/ ^m3 , more preferably in the range of 35 to 140 kg/ ^m3 , even more preferably in the range of 40 to 110 kg/ ^m3 , and particularly preferably in the range of 50 to 80 kg/ ^m3 .

If the density of the α-olefin (co)polymer (B) is greater than the upper limit of the above range, the α-olefin (co)polymer (B) is poorly compatible with the thermoplastic resin (A), which may cause a decrease in the mechanical strength of the resin composition or bleed-out, which is not preferable. On the other hand, if the density of the α-olefin (co)polymer (B) is less than the lower limit of the above range, the low flow start temperature and high fluidity of the α-olefin (co)polymer (B) will not be sufficiently different from that of the thermoplastic resin (A), and the good fluidity improving effect of the α-olefin (co)polymer (B) may not be obtained, which is not preferable. In other words, if the density of the α-olefin (co)polymer (B) is within the above range, a resin composition with excellent compatibility and fluidity improving effect is obtained, with little decrease in mechanical properties, etc., and excellent moldability, which is preferable. In particular, when the thermoplastic resin (A) is a polyolefin, if the density of the α-olefin (co)polymer (B) is within the above range, the α-olefin (co)polymer (B) is likely to exhibit good compatibility with the amorphous portion of the thermoplastic resin (A), and this is preferable because it is possible to suppress bleeding out of the α-olefin (co)polymer (B) and deterioration of the mechanical properties of the resin composition.

The density of the α-olefin (co)polymer (B) according to the present invention is a value determined by the pycnometer method in accordance with JIS K2249-3. The density of the thermoplastic resin (A) is a value measured in accordance with the density gradient tube method in JIS K7112.

<Higher α-olefin (co)polymer>
A preferred embodiment of the α-olefin (co)polymer (B) according to the present invention is a (co)polymer of a monomer consisting of one or more α-olefins having 6 to 20 carbon atoms. The (co)polymer of a monomer consisting of one or more α-olefins having 6 to 20 carbon atoms means an α-olefin homopolymer having 6 to 20 carbon atoms, or an α-olefin copolymer having 6 to 20 carbon atoms containing one or more structural units corresponding to an α-olefin having 6 to 20 carbon atoms. In this specification, such an α-olefin (co)polymer may be referred to as a "higher α-olefin (co)polymer" for convenience. Furthermore, such an α-olefin (co)polymer may contain ethylene and/or an α-olefin having 3 to 5 carbon atoms as a copolymerization component, if necessary, in an amount not exceeding 50 mol %. Such a higher α-olefin (co)polymer is generally referred to as PAO.

In this specification, when the olefin constituting a certain (co)polymer is designated as A, the expression "structural unit derived from A" is sometimes used, but this refers to the "structural unit corresponding to A," that is, the structural unit having a pair of bonds formed by opening the π bond constituting the double bond of A.

Examples of α-olefins having 6 to 20 carbon atoms that can be used in the production of higher α-olefin (co)polymers (PAO) include linear α-olefins such as 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tricene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, and 1-eicosene, as well as branched α-olefins such as 3-methyl-1-pentene, 4-methyl-1-pentene, 8-methyl-1-nonene, 7-methyl-1-decene, 6-methyl-1-undecene, and 6,8-dimethyl-1-decene, with linear α-olefins having 8 to 12 carbon atoms being preferred, and 1-octene and 1-decene being particularly preferred.

In the present invention, the content of constituent units derived from monomers consisting of α-olefins having 6 to 20 carbon atoms constituting the higher α-olefin (co)polymer (PAO) is in the range of 50 to 100 mol %, preferably 55 to 100 mol %, and more preferably 60 to 100 mol %.

In addition, in the present invention, the content of structural units derived from ethylene constituting the higher α-olefin (co)polymer (PAO) is in the range of 0 to 50 mol%, preferably 0 to 45 mol%, and more preferably 0 to 40 mol%.

Furthermore, if necessary, the higher α-olefin (co)polymer (PAO) may contain 0 to 30 mol % of structural units derived from an α-olefin having 3 to 5 carbon atoms. Examples of such α-olefins having 3 to 5 carbon atoms include linear α-olefins such as propylene, 1-butene, and 1-pentene, and branched α-olefins such as 3-methyl-1-butene. These α-olefins having 3 to 5 carbon atoms may be used alone or in combination of two or more.

The methyl group index of the higher α-olefin (co)polymer (PAO) is not particularly limited as long as it is within the range of 25 to 60%, but in order to maintain good compatibility with the thermoplastic resin (A), it is preferably 25 to 40%, and more preferably 25 to 35%.

These α-olefins can be used alone or in combination of two or more.
The above-mentioned higher α-olefin (co)polymers (PAO) can be obtained by oligomerization using an acid catalyst such as boron trifluoride or a chromic acid catalyst, as described in U.S. Pat. Nos. 3,382,291, 3,763,244, 5,171,908, 3,780,128, 4,032,591, JP-A-1-163136, 4,967,032, and 4,926,004. Also, it can be obtained by a method using a catalyst system using a transition metal complex of zirconium, titanium, hafnium, or the like containing a metallocene compound as described in JP-A-63-037102, JP-A-2005-200447, JP-A-2005-200448, JP-A-2009-503147, and JP-A-2009-501836. As a method for producing higher α-olefin (co)polymers (PAO), oligomerization using an acid catalyst is preferred from the viewpoints of versatility of the production method and easy availability of the resulting α-olefin (co)polymers (PAO). Among the acid catalysts, boron trifluoride is particularly preferred in that it can produce a low-order structure.

<Ethylene/α-olefin copolymer>
Another preferred embodiment of the α-olefin (co)polymer (B) according to the present invention is a copolymer of ethylene and an α-olefin having 3 or more carbon atoms (hereinafter also referred to as an "ethylene-α-olefin copolymer"). Examples of the α-olefin constituting the ethylene-α-olefin copolymer include α-olefins other than ethylene. Typical examples include linear α-olefins having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, and 1-eicosene, and branched α-olefins having 3 to 20 carbon atoms, such as 3-methyl-1-pentene, 4-methyl-1-pentene, 8-methyl-1-nonene, 7-methyl-1-decene, 6-methyl-1-undecene, and 6,8-dimethyl-1-decene. In the ethylene/α-olefin copolymer, these α-olefins may be used alone or in combination of two or more. However, in the present invention, in order to distinguish from the above-mentioned "higher α-olefin (co)polymer", the content of structural units corresponding to α-olefins having 6 to 20 carbon atoms in the ethylene/α-olefin copolymer is set to less than 50 mol%. Among these α-olefins, α-olefins having 3 to 10 carbon atoms are preferred, and propylene is particularly preferred, from the viewpoints of the effect of effectively reducing crystallinity to make the resin composition liquid and improving fluidity, and the effect of improving compatibility between the α-olefin (co)polymer (B) and the thermoplastic resin (A).

The ethylene/α-olefin copolymer according to the present invention preferably has an ethylene structural unit content of 30 to 80 mol%, more preferably 40 to 75 mol%, even more preferably 40 to 60 mol%, particularly preferably 40 to 55 mol%, and most preferably 40 to 48 mol%. If the ethylene structural unit content is too high or too low, the crystallinity may increase, compatibility may deteriorate, and the mechanical properties and flow improvement effect may decrease. On the other hand, if the ethylene structural unit content is within the above range, the copolymer will not have crystallinity, and mechanical properties can be maintained, and good flow improvement effects and improved tensile break elongation can be obtained.

The ethylene content of the ethylene/α-olefin copolymer according to the present invention can be measured by ^{a 13C} -NMR method, for example, by identifying and quantifying peaks according to the method described below and the method described in "Polymer Analysis Handbook" (published by Asakura Publishing, pp. 163-170).

The ethylene/α-olefin copolymer according to the present invention preferably has a blockiness (B value) measured by NMR of usually 0.9 or more, preferably 1.0 or more. The B value is a parameter indicating the randomness of the copolymerization monomer chain distribution, and if the B value is small, the crystallinity is high, and the mechanical properties and flow improvement effect may be reduced.

The methyl group index of the ethylene/α-olefin copolymer according to the present invention is not particularly limited as long as it is within the range of 20 to 60%, but in order to maintain good compatibility, 40 to 60% is preferable, 40 to 55% is more preferable, and 45 to 52% is even more preferable.

The method for producing an ethylene-α-olefin copolymer is not particularly limited, but examples include a method using a vanadium catalyst consisting of a vanadium compound and an organoaluminum compound, as described in JP-B-2-1163 and JP-B-2-7998. In addition, as a method for producing a copolymer with high polymerization activity, a method using a catalyst system consisting of a metallocene compound such as zirconocene and an organoaluminum oxy compound (aluminoxane), as described in JP-A-61-221207, JP-B-7-121969, and Japanese Patent No. 2796376, may be used. This method is more preferable because it can reduce the chlorine content of the resulting copolymer and the 2,1-insertion of the α-olefin.

In the method using a vanadium catalyst, a larger amount of chlorine compound is used as a cocatalyst than in the method using a metallocene catalyst, so there is a high possibility that a small amount of chlorine will remain in the obtained ethylene-α-olefin copolymer (B). On the other hand, in the method using a metallocene catalyst, since substantially no chlorine remains, it is preferable in that deterioration of the resin composition due to chlorine can be prevented. The chlorine content is preferably 100 ppm or less, more preferably 50 ppm or less, even more preferably 20 ppm or less, and particularly preferably 5 ppm or less. The chlorine content can be quantified by various known methods. For example, there is a method in which an ethylene-α-olefin copolymer is placed in a sample boat and combusted and decomposed in an Ar/ _O2 stream at a combustion furnace set temperature of 900°C using Thermo Fisher Scientific ICS-1600, and the generated gas is absorbed in an absorption liquid and quantified by ion chromatography.

In addition, the reduction in the 2,1-insertion of the α-olefin makes it possible to further reduce the ethylene chain in the copolymer molecule and suppress the intramolecular crystallinity of ethylene, thereby improving the compatibility with the thermoplastic resin (A) and suppressing the deterioration of mechanical properties and bleed-out. The 2,1-insertion amount of the α-olefin is determined by the analysis of ¹³ C-NMR measurement according to the method described in JP-A-7-145212, and is preferably less than 1%, more preferably 0 to 0.5%, and even more preferably 0 to 0.1%. It is particularly preferable that no peak is observed in the range of 15.0 to 17.5 ppm in the ¹³ C-NMR measurement.

<Other aspects>
The α-olefin (co)polymer (B) according to the present invention may be an unmodified product, or may be one to which some polar group has been imparted by graft modification. Examples of the vinyl compound having a polar group used for modification include vinyl compounds having an oxygen-containing group such as acid, acid anhydride, ester, alcohol, epoxy, or ether, vinyl compounds having a nitrogen-containing group such as isocyanate or amide, and vinyl compounds having a silicon-containing group such as vinyl silane.

Among these, vinyl compounds having an oxygen-containing group are preferred, and specifically, unsaturated epoxy monomers, unsaturated carboxylic acids and their derivatives are preferred. Examples of unsaturated epoxy monomers include unsaturated glycidyl ethers and unsaturated glycidyl esters (e.g., glycidyl methacrylate). Examples of the unsaturated carboxylic acids include acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, and Nadic Acid ^™ (endo-cis-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid).

In addition, examples of derivatives of the unsaturated carboxylic acids include acid halide compounds, amide compounds, imide compounds, acid anhydrides, and ester compounds of the unsaturated carboxylic acids. Specific examples include malenyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, and glycidyl maleate.

Among these, unsaturated dicarboxylic acids and their acid anhydrides are more preferred, and maleic acid, Nadic acid ^™ and their acid anhydrides are particularly preferred.
The position at which the vinyl compound or derivative thereof having a polar group is grafted to the α-olefin (co)polymer (B) is not particularly limited, as long as the unsaturated carboxylic acid or derivative thereof is bonded to any carbon atom of the α-olefin (co)polymer (B).

When the thermoplastic resin (A) has a polar group, imparting the polar group to the α-olefin (co)polymer (B) provides good compatibility between the α-olefin (co)polymer (B) and the thermoplastic resin (A), and can suppress deterioration of the mechanical properties of the resin composition and bleed-out.

The above-mentioned modified α-olefin (co)polymer (B) (modified α-olefin (co)polymer) can be prepared by various conventionally known methods, for example, the following method.
(1) A method in which the above-mentioned α-olefin (co)polymer (B) is mixed in an extruder, a batch reactor, or the like, and a vinyl compound having a polar group or a derivative thereof is added to carry out graft copolymerization.
(2) A method in which the above-mentioned α-olefin (co)polymer (B) is dissolved in a solvent, and a vinyl compound having a polar group or a derivative thereof is added to carry out graft copolymerization.

In either of the above methods, the graft reaction is preferably carried out in the presence of a radical initiator in order to efficiently graft copolymerize the graft monomer of the vinyl compound or its derivative having a polar group.

As the radical initiator, for example, an organic peroxide or an azo compound is used. Examples of the organic peroxide include benzoyl peroxide, dichlorobenzoyl peroxide, and dicumyl peroxide, and examples of the azo compound include azobisisobutylnitrile and dimethylazoisobutyrate.

Specific examples of such radical initiators that are preferably used include dialkyl peroxides such as dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 1,4-bis(tert-butylperoxyisopropyl)benzene.

These radical initiators are usually used in an amount of 0.001 to 1 part by mass, preferably 0.003 to 0.5 parts by mass, and more preferably 0.05 to 0.3 parts by mass, per 100 parts by mass of the α-olefin (co)polymer (B).

The reaction temperature in the graft reaction using the above-mentioned radical initiator or in the graft reaction without using a radical initiator is usually set in the range of 60 to 350°C, preferably 120 to 300°C.

The graft amount of the vinyl compound having a polar group in the modified α-olefin (co)polymer thus obtained is usually 0.01 to 15% by mass, preferably 0.05 to 10% by mass, assuming the mass of the modified olefin polymer to be 100% by mass.

<Content of α-olefin (co)polymer (B)>
The content of the α-olefin (co)polymer (B) in the entire resin composition of the present invention is 0.01 to 3.8 mass%, preferably 0.2 to 3 mass%, more preferably 0.6 to 3 mass%, and particularly preferably 0.6 to 2 mass%.

If the content of the α-olefin (co)polymer (B) in the entire resin composition is less than the lower limit, the flow improvement effect of the α-olefin (co)polymer (B) is not fully expressed. On the other hand, if the content of the α-olefin (co)polymer (B) in the entire resin composition exceeds the upper limit, the mechanical strength of the resin composition may decrease or bleed out, which is not preferable. In other words, if the content of the α-olefin (co)polymer (B) is within the above range, it is preferable because a resin composition with excellent mechanical strength and moldability is easily obtained without bleed out. The above effect is particularly useful for low MFR thermoplastic resin (A) with excellent mechanical strength, since it can improve moldability while maintaining its characteristic mechanical strength.

Other Components The resin composition of the present invention may contain additives such as antioxidants, ultraviolet absorbers, stabilizers such as light stabilizers, metal soaps, fillers, flame retardants, antibacterial agents, antifungal agents, pigments, etc., as necessary.
Examples of the stabilizer include antioxidants such as hindered phenol compounds, phosphite compounds, and thioether compounds; ultraviolet absorbers such as benzotriazole compounds and benzophenone compounds; and light stabilizers such as hindered amine compounds.

Examples of the metal soap include stearates such as magnesium stearate, calcium stearate, barium stearate, and zinc stearate.
Examples of the filler include glass fiber, silica fiber, metal fiber (stainless steel, aluminum, titanium, copper, etc.), natural fiber (wood flour, wood fiber, bamboo, bamboo fiber, cotton, cellulose, nanocellulose, wool, straw, hemp, flax, kenaf, kapok, jute, ramie, sisal, henequen, corn, nut shells, wood pulp, rayon, cotton, etc.), carbon black, graphite, activated carbon, graphite, carbon nanotubes, carbon nanofibers, carbon nanohorns, graphene nanoplatelets, nanoporous carbon, carbon fibers, silica, glass beads, silicates (calcium silicate Examples of the fillers include powders of various metals (magnesium, silicon, aluminum, titanium, copper, etc.), metal oxides (iron oxide, titanium oxide, magnesium oxide, alumina, etc.), metal carbonates (calcium carbonate, barium carbonate, etc.), sulfates (calcium sulfate, barium sulfate, etc.), and powders of various metals (magnesium, silicon, aluminum, titanium, copper, etc.), mica, glass flakes, pumice powder, pumice balloon, aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, dolomite, calcium titanate, calcium sulfite, asbestos, montmorillonite, bentonite, molybdenum sulfide, organic fillers (lignin, starch, etc.), and products containing the same. In particular, fillers having anisotropy in their structure, such as glass fibers, silica fibers, metal fibers, natural fibers, carbon nanotubes, carbon nanofibers, carbon nanohorns, and carbon fibers, tend to break due to shear during kneading, resulting in a decrease in anisotropy and a loss of their characteristics, but the α-olefin (co)polymer (B) is useful because it reduces shear during kneading due to its flowability improving effect and makes it easier to maintain anisotropy.

Examples of the flame retardant include halogenated diphenyl ethers such as degabromdiphenyl ether and octabromdiphenyl ether, halogenated polycarbonates, and other halogen compounds; inorganic compounds such as antimony trioxide, antimony tetraoxide, antimony pentoxide, sodium pyroantimonate, and aluminum hydroxide; and phosphorus-based compounds. Compounds such as tetrafluoroethylene can also be added as flame retardant assistants to prevent dripping.

The above-mentioned antibacterial and antifungal agents include organic compounds such as imidazole compounds, thiazole compounds, nitrile compounds, haloalkyl compounds, and pyridine compounds; and inorganic substances and compounds such as silver, silver compounds, zinc compounds, copper compounds, and titanium compounds.

As the pigment, pigments that have been conventionally used for coloring synthetic resins can be used. Specifically, metals such as aluminum, silver, and gold; carbonates such as _calcium carbonate and _barium carbonate; _oxides such as ZnO and _TiO2 ; hydroxides such as _Al2O3.nH2O and _Fe2O3.nH2O ; sulfates such as _CaSO4 and _BaSO4 ; nitrates such as Bi( _OH ) _2NO3 ; chlorides such as _PbCl2 ; chromates such as _CaCrO4 and _BaCrO4 ; chromates, manganates, and permanganates such as _CoCrO4 ; _borates such as Cu(BO) ₂ ; uranates such as _Na2U2O7.6H2O ; nitrites such as _K3Co ( _NO2 ) _{6.3H2O ;} silicates _such as _SiO2 ; _CuAsO3.Cu ( _{OH )} arsenates and arsenites such as _Cu ( _{C2H3O2 ) 2.Cu} ( _OH ) ₂ ; acetates such as _Cu (C2H3O2) _2.Cu (OH)2; phosphates such as ( _NH4 ) _2MnO2 ( _P2O7 ) ₂ ; aluminates, molybdates, zincates, antimonates, tungstate selenides, titanates, ferric cyanides, phthalates, inorganic pigments such as CaS, ZnS, CdS, graphite, carbon black; natural organic pigments such as cochineal lake, madder lake; nitroso pigments such as Naphthol Green Y, Naphthol Green B; nitro pigments such as Naphthol Yellow S, Pigment Chlorin 2G; Permanent Red 4R; Hansa Ero Examples of the pigments include azo pigments such as Brilliant Carmine 68 and Scarlet 2R; basic dye lakes such as Malacaine Green and Rhodamine B; acid dye lakes such as Acid, Green Lake and Eosin Lake; mordant dye lakes such as Alizarin Lake and Purpurin Lake; vat dye pigments such as Thio Indigo Red B and Instanthrene Orange; and organic pigments such as phthalocyanine pigments such as Phthalocyanine Blue and Phthalocyanine Green.
The above additives can be used in any proportion and by any method of addition as long as the effects of the present invention are not impaired.

Resin composition The resin composition according to the present invention is characterized in that it contains a thermoplastic resin (A) and an α-olefin (co)polymer (B) as essential components. In addition, the resin composition may contain the above-mentioned other components within the range that does not impair the effects of the invention.

The composition and molecular weight of the resin composition according to the present invention are not particularly limited as long as they do not impair the present invention. From the viewpoint of obtaining good moldability and mechanical properties, the proportion of components having a molecular weight of less than 5,000 as observed by gel permeation chromatography (GPC) is preferably 0.7 to 4.5% of the total components of the resin composition, more preferably 1.0 to 4.5%, even more preferably 1.2 to 4.5%, and particularly preferably 1.3 to 3.0%. Components having a molecular weight of less than 5,000 improve the moldability of the resin composition, but can cause problems such as a decrease in mechanical properties and bleed-out. If the proportion of components having a molecular weight of less than 5,000 in the resin composition is within the above range, it is preferable because it is easy to obtain the effect of improving moldability while suppressing problems such as a decrease in mechanical properties and bleed-out.

The resin composition according to the present invention is produced by melt-kneading the thermoplastic resin (A), the α-olefin (co)polymer (B), and additives as required. As a method for melt-kneading, a single screw extruder, a twin screw extruder, or the like can be used.

As a method for adding the α-olefin (co)polymer (B) to the thermoplastic resin (A), various methods can be used within the scope of the invention without impairing the effects of the invention. For example, the thermoplastic resin (A) and the α-olefin (co)polymer (B) are dry-blended using a high-speed mixer such as a Henschel mixer or a tumbler, and then melt-kneaded, or the α-olefin (co)polymer (B) is added directly from an open part or is inserted using a side feeder or liquid feed pump while the thermoplastic resin (A) is being melt-kneaded, and then melt-kneaded. Among the above methods, the method of dry-blending the thermoplastic resin (A) and the α-olefin (co)polymer (B) and then melt-kneading is preferred because the flowability improving effect of the α-olefin (co)polymer (B) can be obtained from the initial melting stage of the thermoplastic resin (A).

There are no particular limitations on the temperature during melt kneading, so long as it is a temperature at which the thermoplastic resin (A) etc. melts. For example, when the thermoplastic resin (A) is polypropylene, the temperature is usually in the range of 190 to 300°C, preferably 200 to 250°C.

<Production method using masterbatch containing α-olefin (co)polymer (B)>
As a method for producing the resin composition according to the present invention, a method is particularly preferred in which an α-olefin (co)polymer (B) is melt-kneaded with a thermoplastic resin (A) to produce a master batch containing an α-olefin (co)polymer (B), and then the thermoplastic resin (A) is added to the master batch containing the α-olefin (co)polymer (B), and the two are melt-kneaded to produce a resin composition.

When a masterbatch containing α-olefin (co)polymer (B) is used, it is preferable because it is possible to prevent a decrease in moldability due to the α-olefin (co)polymer (B) causing slippage in the extruder. In addition, since the α-olefin (co)polymer (B) has the property of easily becoming liquid at room temperature even when melt-kneaded with the thermoplastic resin (A), it softens and melts the components of the thermoplastic resin (A) early in the initial stage of melt-kneading. Therefore, even when the masterbatch containing α-olefin (co)polymer (B) is kneaded together with the thermoplastic resin (A) in an extruder, it can show a good flowability improving effect.

The resin composition produced by the manufacturing method using the masterbatch containing α-olefin (co)polymer (B) contains 25 to 99.99 mass% of the thermoplastic resin (A) used to produce the masterbatch and the thermoplastic resin (A) added to the masterbatch after the masterbatch is produced, and 0.01 to 3.8 mass% of the α-olefin (co)polymer (B).

The thermoplastic resin (A) used to produce the masterbatch containing α-olefin (co)polymer (B) and the thermoplastic resin (A) added to the masterbatch after the masterbatch is produced may be the same or different resins.

The method for producing the masterbatch containing the α-olefin (co)polymer (B) is not particularly limited, but examples include a method in which the α-olefin (co)polymer (B) and the thermoplastic resin (A) and, if necessary, additives are melt-kneaded using a single-screw extruder, twin-screw extruder, plastomill, Brabender, kneader, roll mixer, Banbury mixer, etc. Among these, the method using a single-screw extruder or twin-screw extruder is preferred from the viewpoints of ease of mass production and ease of obtaining a pellet-like masterbatch, and the method using a twin-screw extruder is particularly preferred from the viewpoints of increasing the compatibility of the α-olefin (co)polymer (B) and suppressing bleed-out.

There are no particular limitations on the temperature during melt kneading in the production of the masterbatch, so long as it is a temperature at which the thermoplastic resin (A) etc. melts. For example, when the thermoplastic resin (A) is polypropylene, the temperature is usually in the range of 190 to 300°C, preferably 200 to 250°C.

The amount of α-olefin (co)polymer (B) in the α-olefin (co)polymer (B)-containing masterbatch used in the present invention is not particularly limited, but is usually in the range of 0.1 to 100 parts by mass, preferably in the range of 0.1 to 20 parts by mass, more preferably in the range of 0.5 to 10 parts by mass, and particularly preferably in the range of 3 to 10 parts by mass, per 100 parts by mass of the thermoplastic resin (A) contained in the α-olefin (co)polymer (B)-containing masterbatch.

When α-olefin (co)polymer (B) is blended in a mass equal to or greater than the lower limit of the above range, the α-olefin (co)polymer (B) makes it easier for the thermoplastic resin (A) to soften and melt, and a good flowability improving effect is obtained when the α-olefin (co)polymer (B)-containing masterbatch and the thermoplastic resin (A) that is further added are melt-kneaded in an extruder, so this is preferred. In addition, when α-olefin (co)polymer (B) is blended in a mass equal to or less than the upper limit of the above range, bleeding out of the α-olefin (co)polymer (B) can be suppressed, and a non-sticky α-olefin (co)polymer (B)-containing masterbatch can be obtained, so this is preferred.

There are no particular limitations on the method of melt-kneading the masterbatch containing α-olefin (co)polymer (B) with the thermoplastic resin (A) added to the masterbatch, and for example, the same melt-kneading method as in the above-mentioned method for producing the masterbatch containing α-olefin (co)polymer (B) can be used.

The ratio of the amount of the α-olefin (co)polymer (B)-containing master batch to the amount of the thermoplastic resin (A) added to the master batch is preferably 1 to 110 parts by mass, more preferably 15 to 110 parts by mass, and particularly preferably 15 to 50 parts by mass, per 100 parts by mass of the thermoplastic resin (A) added to the master batch. If the ratio of the amount of the α-olefin (co)polymer (B)-containing master batch to the amount of the thermoplastic resin (A) added to the master batch is smaller than the lower limit of the above range, the content of the α-olefin (co)polymer (B) in the resin composition is reduced, and the effect of improving moldability may be difficult to achieve. On the other hand, if the ratio of the amount of the α-olefin (co)polymer (B)-containing master batch to the amount of the thermoplastic resin (A) added to the master batch is greater than the upper limit of the above range, the content of the α-olefin (co)polymer (B) is increased, which is likely to cause a decrease in mechanical properties.

Molded Article The molded article of the present invention is a molded article containing the above-mentioned resin composition. The molded article of the present invention can be obtained, for example, by melt-kneading the above-mentioned thermoplastic resin (A) and α-olefin (co)polymer (B). In this case, as described above, a master batch containing α-olefin (co)polymer (B) may be produced, and the thermoplastic resin (A) may be further added to the master batch and melt-kneaded. In addition, the resin composition may be melt-kneaded and then immediately molded to obtain a molded article.

Examples of the molding method include T-die molding, blow molding, injection molding, and other known molding methods.
For example, when polypropylene is used as the thermoplastic resin (A) and an extruded sheet or film is formed by T-die extrusion or the like, a molded product is obtained by extrusion molding usually in the range of 170 to 300° C., preferably 180 to 270° C., more preferably 190 to 250° C. A stretched film is obtained by stretching a film extruded from an extruder, for example, by a tenter method (longitudinal and transverse stretching, transverse and longitudinal stretching), a simultaneous biaxial stretching method, or a uniaxial stretching method.

When using polypropylene as the thermoplastic resin (A) to obtain the molded article of the present invention by extrusion blow molding, it is extruded from a die as a tubular parison at a resin temperature in the range of 170 to 240°C, and then the parison is held in a mold of the desired shape, after which air is blown into it and the mold is fitted at a resin temperature in the range of 160 to 230°C to obtain the molded article. In addition, the molded article may be stretched to an appropriate ratio during extrusion blow molding.

When injection molding is performed using polypropylene as the thermoplastic resin (A), the cylinder temperature during injection molding is usually in the range of 180 to 400°C, preferably 200 to 300°C, and more preferably 200 to 250°C, the injection pressure is usually in the range of 10 to 200 MPa, and preferably 20 to 150 MPa, and the mold temperature is usually in the range of 20 to 200°C, preferably 20 to 80°C, and more preferably 20 to 60°C.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples in any way.
In the following examples and comparative examples, the physical properties were measured or evaluated by the following methods.

[Methyl group index]
Measurements were performed using a nuclear magnetic resonance apparatus, EX270, manufactured by JEOL Ltd., with deuterated chloroform as the solvent, a sample concentration of 55 mg/0.6 mL, room temperature as the measurement temperature, ¹ H (270 MHz) as the observation nucleus, single pulse as the sequence, pulse width of 6.5 μsec (45° pulse), repetition time of 5.5 sec, number of accumulations of 16, and 7.24 ppm of the solvent peak based on _CHCl in deuterated chloroform as the reference value for chemical shift.

The ratio of the integral value of the peak in the range of 0.50 to 1.15 ppm to the integral value of the peak in the range of 0.50 to 2.20 ppm in the ^1H -NMR spectrum measured as described above was taken as the methyl group index. Here, the range of 0.50 to 2.20 ppm contains almost all peaks due to the α-olefin (co)polymer. Of this range, the peak due to the methyl group is highly likely to be contained in the range of 0.50 to 1.15 ppm.

[Melting Point]
The melting point was measured using a Seiko Instruments X-DSC-7000. Approximately 8 mg of the sample was placed in a simple, airtight aluminum sample pan and placed in a DSC cell. The DSC cell was heated from room temperature to 150°C at 10°C/min under a nitrogen atmosphere, then held at 150°C for 5 minutes, and then cooled at 10°C/min to cool the DSC cell to -100°C (cooling down process). Next, the sample was held at -100°C for 5 minutes, and then heated to 150°C at 10°C/min. The temperature at which the enthalpy curve obtained during the heating process showed a maximum value was taken as the melting point (Tm), and the sum of the endothermic heats associated with melting was taken as the heat of fusion (ΔH). If no peak was observed or the value of the heat of fusion (ΔH) was 1 J/g or less, it was considered that the melting point (Tm) was not observed. The melting point (Tm) and the heat of fusion (ΔH) were determined in accordance with JIS K7121.

[Weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn)]
The molecular weight of the α-olefin (co)polymer (B) was measured using the following high-speed GPC measuring device. Calibration was performed using monodisperse polystyrene with a known molecular weight as a standard substance.
Measuring device: Tosoh HLC8320GPC
Mobile phase: THF (manufactured by Wako Pure Chemical Industries, Ltd., stabilizer-free, liquid chromatography grade)
Column: Two TSKgel Super Multipore HZ-M columns manufactured by Tosoh Corporation were connected in series.
Sample concentration: 5 mg/mL
Mobile phase flow rate: 0.35 mL/min Measurement temperature: 40°C
Standard sample for calibration curve: PStQuick MP-M manufactured by Tosoh Corporation
The molecular weight of the polyethylene wax used in the Comparative Examples was measured using the following measuring device. Calibration was performed using monodisperse polystyrene with a known molecular weight as a standard substance.
Measurement device: Tosoh HLC-8321 GPC/HT Mobile phase: o-dichlorobenzene Column: Tosoh TSKgel GMH6-HT (2 columns) and TSKgel GMH6-HTL (2 columns) connected in series Sample concentration: 0.1 mg/mL
Mobile phase flow rate: 1.0 mL/min Measurement temperature: 140°C
Standard sample for calibration curve: Tosoh monodisperse polystyrene #3 std set

〔density〕
The density of the thermoplastic resin (A) and the polyethylene wax used in the comparative examples was determined by the density gradient tube method in accordance with JIS K7112.
The density of the α-olefin (co)polymer (B) was determined by the pycnometer method in accordance with JIS K2249-3.

[MFR]
The MFR of the thermoplastic resin (A) was measured in accordance with JIS K 7210 under conditions of 230° C. and a test load of 2.16 kgf.
In the following Examples and Comparative Examples, the following raw materials were used.

Thermoplastic resin (A)
[Production Example of Thermoplastic Resin (A)]
A 10-liter continuous polymerization reactor, fully purged with nitrogen, was filled with 6000 ml of dehydrated and purified hexane, and 100 mmol of triethylaluminum and 10 mmol of a solid titanium catalyst component prepared according to the method of Example 1 of JP-A-58-38006 were charged in terms of titanium atoms. Then, propylene was continuously fed to the reactor for 1 hour so that the total amount was 50 g per 10 g of titanium component. The temperature was kept at 10° C. during this period. After 1 hour, the introduction of propylene was stopped, and the reactor was fully purged with nitrogen. The solid portion of the obtained slurry was washed five times with purified hexane to obtain a titanium-containing polypropylene. Next, a 2000-liter continuous polymerization reactor, fully purged with nitrogen, was charged with 500 kg of propylene, 0.173 mol of cyclohexylmethyldimethoxysilane, and 10 L of hydrogen, and the internal temperature of the polymerization reactor was raised to 65° C. Next, the titanium-containing polypropylene obtained earlier was charged in an amount of 0.00650 mol in terms of titanium atoms, and the internal temperature of the polymerization vessel was raised to 70° C., and propylene polymerization was carried out for 1 hour. After 1 hour, the introduction of propylene was stopped, and the reactor was fully substituted with nitrogen to obtain a white granular polymer. The obtained polymer was dried under reduced pressure at 70° C., and then extruded at 230° C. using an extrusion granulator with a screw diameter of 65 mm, and pelletized to obtain polypropylene, which is a thermoplastic resin (A). The obtained polypropylene was used as a thermoplastic resin (a). The obtained thermoplastic resin (a) had a weight average molecular weight (Mw): 609,000, MFR: 3.0 g/10 min, and density: 910 kg/m ³ .

α-Olefin (co)polymer (B)
[Production Example of α-Olefin (Co)polymer (B)]
A 2-liter continuous polymerization reactor equipped with an agitator and fully purged with nitrogen was filled with 1 liter of dehydrated and purified hexane, and a hexane solution of ethylaluminum sesquichloride (Al(C ₂ H ₅ ) _1.5 ·Cl _1.5 ) adjusted to 96 mmol/L was continuously fed at a rate of 500 ml/h for 1 hour. Then, a hexane solution of VO(OC ₂ H ₅ )Cl ₂ adjusted to 16 mmol/L as a catalyst was continuously fed at a rate of 500 ml/h, and hexane was continuously fed at a rate of 500 ml/h. Meanwhile, the polymerization liquid was continuously extracted from the top of the polymerization vessel so that the polymerization liquid in the polymerization vessel was always 1 liter. Next, ethylene gas was fed at a rate of 35 L/h, propylene gas at a rate of 35 L/h, and hydrogen gas at a rate of 80 L/h using a bubbling tube. The copolymerization reaction was carried out at 35°C by circulating a coolant through a jacket attached to the outside of the polymerization vessel. As a result, a polymerization solution containing an ethylene-propylene copolymer was obtained. The obtained polymerization solution was deashed with hydrochloric acid, and then poured into a large amount of methanol to precipitate an ethylene-propylene copolymer, followed by drying under reduced pressure at 130°C for 24 hours to obtain an α-olefin (co)polymer which is α-olefin (co)polymer (B). The obtained α-olefin (co)polymer was designated as α-olefin (co)polymer (b). The obtained α-olefin (co)polymer (b) had a methyl group index of 47.6%, a weight average molecular weight (Mw): 4170, a molecular weight distribution (Mw/Mn): 1.7, a density: 843 kg/ ^m3 , and no melting point was observed.

Polyethylene wax [Production example of polyethylene wax]
1. Preparation of catalyst In a glass autoclave with an internal volume of 1.5 liters, 25 g of commercially available anhydrous magnesium chloride was suspended in 500 ml of hexane. This was kept at 30°C and stirred while 92 ml of ethanol was added dropwise over 1 hour, and the reaction was continued for another 1 hour. After the reaction was completed, 93 ml of diethylaluminum monochloride was added dropwise over 1 hour, and the reaction was continued for another 1 hour. After the reaction was completed, 90 ml of titanium tetrachloride was added dropwise, and the reaction vessel was heated to 80°C and reacted for 1 hour. After the reaction was completed, the solid portion was washed with hexane by decantation until free titanium was no longer detected. This was suspended in hexane and the titanium concentration was quantified by titration, and the suspension was subjected to the following experiment.

2. Production of polyethylene wax 930 ml of hexane and 70 ml of propylene were charged into a 2-liter stainless steel autoclave that had been thoroughly purged with nitrogen, and hydrogen was introduced until the pressure reached 0.1 MPa (gauge pressure). Next, the temperature in the system was raised to 170°C, and then 0.1 mmol of triethylaluminum, 0.4 mmol of ethylaluminum sesquichloride, and the hexane suspension of the solid obtained above were injected with ethylene so that the amount of titanium component was 0.008 mmol in atomic terms, to initiate polymerization. Then, ethylene alone was continuously fed to maintain the total pressure at 2.9 MPa (gauge pressure), and polymerization was carried out at 170°C for 40 minutes.

After the polymerization was stopped by adding a small amount of ethanol to the system, unreacted ethylene and propylene were purged. The resulting polymer solution was dried overnight under reduced pressure at 100°C to obtain a polyethylene wax. The resulting polyethylene wax had a density of 926 kg/ ^m3 , a weight average molecular weight (Mw): 10,270, a molecular weight distribution (Mw/Mn): 2.8, and a melting point of 109°C.

Example 1
[Preparation of Masterbatch (1)]
In a 15 mmφ twin-screw extruder, the thermoplastic resin (a) was added from the hopper and the α-olefin (co)polymer (b) was added from the C5 vent in the ratios shown in Table 1. The mixture was melt-kneaded and then molded into pellets using a pelletizer to prepare a master batch (1).

[T-die film molding]
A 20 mmφ single-screw extruder (Toyo Seiki Seisakusho, D2020) was equipped with a T-die having a die width of 150 mm, and the rotation speed was set to 25 rpm, the cylinder temperature, and the die temperature to 205 ° C. The resin composition obtained by dry blending the thermoplastic resin (a) and the master batch (1) in the composition shown in Table 2 was added from a hopper to perform extrusion film molding to obtain a film having a thickness of 50 μm.

Example 2
A film was obtained in the same manner as in Example 1, except that the blending ratio of the thermoplastic resin (a) and the master batch (1) during T-die film molding was set to the ratio shown in Table 2.

Example 3
[Production of Masterbatch (2)]
A master batch (2) was obtained in the same manner as in Example 1, except that the blending ratio of the thermoplastic resin (a) and the α-olefin (co)polymer (b) was set to the ratio shown in Table 1.

[T-die film molding]
A film was obtained in the same manner as in Example 1, except that the master batch (2) was used instead of the master batch (1) and the blending ratio of the thermoplastic resin (a) and the master batch (2) during T-die film molding was set to the ratio shown in Table 2.

Comparative Example 1
A film was obtained in the same manner as in Example 1, except that in the T-die film molding, only the thermoplastic resin (a) was used without using a master batch.

Comparative Example 2
A film was obtained in the same manner as in Example 3, except that the blending ratio of the thermoplastic resin (a) and the master batch (2) during T-die film molding was set to the ratio shown in Table 2.

Comparative Example 3
A film was obtained in the same manner as in Example 1, except that the above polyethylene wax was used instead of the master batch (1) and the blending ratio of the thermoplastic resin (a) and the polyethylene wax during T-die film molding was set to the ratio shown in Table 2.

Comparative Example 4
A film was obtained in the same manner as in Comparative Example 3, except that the blending ratio of the thermoplastic resin (a) and the polyethylene wax during T-die film molding was set to the ratio shown in Table 2.
The moldability during T-die film molding and the physical properties of the obtained film were evaluated for the following items. The results are shown in Table 2.

[Extrusion torque]
The resin was charged from the hopper, and the torque value of the extruder was measured for 1 minute starting 10 minutes after the extruder was set to the above molding conditions, and the average value was calculated. If this value is small, it is difficult to reach the upper limit of the device capacity even when the extrusion torque increases during molding, making it easier to reduce unevenness in the discharge rate during molding. Also, if this value is small, it is difficult to reach the upper limit of the device capacity when the screw rotation speed of the extruder is increased, making it easier to adjust the discharge rate.

[Discharge volume]
The resin was charged from the hopper, and the extruder was set under the above molding conditions. 10 minutes later, the mass of the film extruded per minute was measured, and the extrusion rate per hour was calculated from this value.

[Tensile breaking strength, tensile breaking elongation, tensile product]
According to JIS K7127, the film was measured in the machine direction to determine the strength and elongation at which the film broke, which were defined as the tensile breaking strength and tensile breaking elongation, respectively. The product of the tensile breaking strength and the tensile breaking elongation was defined as the tensile tensile product. The larger this value, the more difficult the film is to break, and a value of 30,000 MPa.% or more in particular indicates that the film is resistant to breakage.

[Proportion of components with molecular weight less than 5,000]
The molecular weights of the components contained in the obtained film were measured using the following measuring device, and the proportion of components having a molecular weight of less than 5,000 was calculated from the ratio of the peak area of components having a molecular weight of less than 5,000 to the total peak area. Calibration was performed using monodisperse polystyrene of known molecular weight as a standard substance.
Measurement device: Tosoh HLC-8321 GPC/HT Mobile phase: o-dichlorobenzene Column: Tosoh TSKgel GMH6-HT (2 columns) and TSKgel GMH6-HTL (2 columns) connected in series Sample concentration: 0.1 mg/mL
Mobile phase flow rate: 1.0 mL/min Measurement temperature: 140°C
Standard sample for calibration curve: Tosoh monodisperse polystyrene #3 std set

The results in Table 2 show that Examples 1 to 3 have a smaller extrusion torque and a larger discharge amount than Comparative Example 1. This shows that compared to Comparative Example 1, in which thermoplastic resin (a) was molded alone, Examples 1 to 3, in which α-olefin (co)polymer (b) was added to thermoplastic resin (a), had improved moldability.

In addition, it can be seen that, compared to Comparative Example 1, Examples 1 to 3 show only a slight decrease in tensile breaking strength, but a significant improvement in tensile breaking elongation. This is believed to be because the α-olefin (co)polymer (b) exhibits good compatibility with the amorphous portion of the thermoplastic resin (a). As a result, Examples 1 to 3 show an improvement in tensile product, resulting in molded articles that are more resistant to breakage.

On the other hand, when Examples 1 to 3 are compared with Comparative Example 2, it can be seen that, although the improvement in formability is low in Examples 1 to 3, the tensile product value is large, and a film resistant to breakage is obtained. This is thought to be because, in Comparative Example 2, the amount of α-olefin (co)polymer (b) added is large, resulting in a significant decrease in tensile strength at break, whereas, in Examples 1 to 3, the amount of α-olefin (co)polymer (b) added is kept within an appropriate range, thereby suppressing the decrease in tensile strength at break.

From the results in Table 2, when Examples 1 to 3 and Comparative Examples 3 to 4 are compared with Comparative Example 1, it can be seen that in Comparative Examples 3 to 4, the extrusion torque is significantly reduced compared to Comparative Example 1, but the discharge amount is also significantly reduced. This indicates that slippage occurs in the extruder due to the molding aid, and moldability is reduced. In contrast, in Examples 1 to 3, the α-olefin (co)polymer (b) and the thermoplastic resin (a) are added as a master batch in which they are melt-kneaded in advance, preventing the occurrence of slippage, and the effects of reducing the extrusion torque and increasing the discharge amount are obtained, resulting in good moldability. In addition, when Examples 1 to 3 are compared with Comparative Examples 3 to 4, Examples 1 to 3 show large values for tensile breaking strength, tensile breaking elongation, and tensile product, indicating that the molded product is resistant to breakage. This is thought to be because the α-olefin (co)polymer (b) has better compatibility than polyethylene wax. The α-olefin (co)polymer (b) is characterized by not only improving moldability but also enabling the production of molded products that are difficult to break.

Claims (6)

A resin composition comprising 90 to 99.99 mass% of a thermoplastic resin (A) having a polystyrene-equivalent weight average molecular weight (Mw) of 5,000 or more as measured by gel permeation chromatography (GPC), and 0.01 to 3.8 mass% of an α-olefin (co)polymer (B) satisfying the following requirements (b-1) to (b-4):
The thermoplastic resin (A) is a polyolefin,
The resin composition, wherein the α-olefin (co)polymer (B) is a copolymer of ethylene and an α-olefin having 3 or more carbon atoms.
(b-1) The methyl group index measured from ¹ H-NMR is 25 to 60%. (Here, the methyl group index refers to the ratio of the integral value of a peak within the range of 0.50 to 1.15 ppm to the integral value of a peak within the range of 0.50 to 2.20 ppm when the α-olefin (co)polymer is dissolved in deuterochloroform and ¹ H-NMR is measured, and the solvent peak appearing at 7.24 ppm based on _CHCl 3 in deuterochloroform is used as a reference.)
(b-2) No melting point is observed in differential scanning calorimetry (DSC).
(b-3) The weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 1,000 to 20,000.
(b-4) The density measured by the pycnometer method is 810 to 870 kg/ ^m3 . The resin composition according to claim 1, wherein the thermoplastic resin (A) is polypropylene. 3. The resin composition according to claim 1, wherein the α-olefin (co)polymer (B) is an ethylene-propylene copolymer. 4. The resin composition according to claim 1, wherein the proportion of components having a molecular weight of less than 5,000 as determined by gel permeation chromatography (GPC) is in the range of 0.7 to 4.5 mass % based on the total components. The method for producing the resin composition according to any one of claims 1 to 4, comprising: a step of kneading 0.1 to 100 parts by mass of the α-olefin (co)polymer (B) with 100 parts by mass of the thermoplastic resin (A) to obtain a master batch; and a step of kneading the thermoplastic resin (A) and the master batch in an extruder. A molded article comprising the resin composition according to any one of claims 1 to 4 .