JP2002060562A - Resin compostion and resin molded product by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for welding, utilizable in electric and electronic fields, an automotive field and other of various kinds of industrial field, excellent in mechanical strength, impact resistance, heat resistance and chemical resistance, and excellent in stability of the weld strength, and to provide a molded product by using the composition. SOLUTION: This resin composition comprising total 100 pts.wt. of 5-60 pts.wt. polyphenylene ether resin, and 40-95 pts.wt. crystalline polypropylene resin, and 1-30 pts.wt. hydrogenated product of a vinyl aromatic compound- conjugate diene copolymer is characterized in that the crystalline polypropylene resin and the polyphenylene ether resin form a continuous phase and a dispersed phase respectively, and the ratio Lw/Ln of the arithmetic mean (Ln) of the distances between particle walls of the dispersed phase, to the weighted mean (Lw) of the distances between the particle walls is 1.0-3.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to the fields of electricity and electronics,
A welding resin composition having excellent mechanical strength, impact resistance, heat resistance, chemical resistance, and excellent welding strength stability, and a molded article using the same, which can be used in the field of automobiles and various other industrial materials. And a battery case for a secondary battery.

[0002]

2. Description of the Related Art Polyphenylene ether resins are widely used in various industrial applications such as electric / electronic parts, OA equipment parts, and automobile parts because of their excellent mechanical strength, heat resistance, electric properties and dimensional stability. ing. However, since it is an amorphous resin, it has a drawback of poor chemical resistance, and is currently difficult to use in applications where oils and drugs adhere or come into contact. On the other hand, polypropylene resins are inexpensive, lightweight, excellent in moldability and chemical resistance, and are very widely used in various applications such as automotive parts such as bumpers, sheets and films. However, at present, mechanical strength and heat resistance are inferior to polyphenylene ether-based resins.

Therefore, a polymer blend utilizing the advantages of both, ie, a composition having both the strength and heat resistance of a polyphenylene ether-based resin and the chemical resistance of a polypropylene resin has been proposed. For example, U.S. Pat. No. 3,361,851 describes that a composition having excellent chemical resistance can be obtained by blending a polyphenylene ether and a polyolefin resin. 2-3058 Kaihei
No. 14 describes that the compatibility of both resins is improved by adding a hydrogenated block copolymer to a resin composition comprising a polyphenylene ether-based resin and a polyolefin resin. Utilizing the characteristics of the blend of the polyphenylene ether-based resin and the polypropylene resin, JP-A-8-195188 and JP-A-9-
No. 120801 proposes using a blend of a polyphenylene ether-based resin and a polypropylene resin for a battery case of a sealed battery. This is to improve the mechanical strength and heat resistance by blending a polyphenylene ether resin while taking advantage of the chemical resistance and steam barrier properties of polypropylene resin, and these technologies are certainly It can provide chemical resistance, mechanical strength, and heat resistance, which could not be achieved with a polypropylene resin alone or a polyphenylene ether-based resin alone.

[0004] However, in recent years, as electric vehicles are put into practical use, more demands have been placed on sealed secondary batteries used for these vehicles. Specifically, the rise in operating temperature, the rise in internal pressure, and the
Demand for pressure resistance at high temperatures is increasing.

When a blend of a polyphenylene ether-based resin and a polypropylene resin is used for a pressure vessel such as a battery case of a secondary battery, the sealing method becomes a problem. Usually, welding is performed for joining and sealing the container body and the lid, for example, from the simplicity of the process. For example, a method in which a resin component is brought into contact with a heated plate and the surface is melted and welded (hot plate welding), the method in which the surface is melted and welded by vibration (vibration welding), and the surface is melted by ultrasonic waves A typical example is a welding method (ultrasonic welding). However, in a conventional blend of a polyphenylene ether-based resin and a polypropylene resin, the problem that the welding strength is low and the welded portion peels off when an internal pressure is applied has been highlighted. In particular, there is a large variation in welding strength, which is a serious problem in actual use.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to a welding resin molded article having excellent mechanical strength, heat resistance, impact resistance, and chemical resistance, and excellent welding strength and stability, and characteristics thereof. The object of the present invention is to provide a battery case for a secondary battery utilizing the above.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the present invention has a specific form consisting of a polyphenylene ether resin, a crystalline polypropylene resin, and a block copolymer. The present inventors have found that a resin composition has excellent mechanical strength, heat resistance, impact resistance, chemical resistance, and welding strength stability, and have reached the present invention.

That is, the present invention relates to a polyphenylene ether resin 5 to 60 parts by weight, a crystalline polypropylene resin 4
The hydrogenated product of the vinyl aromatic compound-conjugated diene copolymer was added in an amount of 1 to 3 with respect to 100 parts by weight of 0 to 95 parts by weight.
In the resin composition containing 0 parts by weight, the crystalline polypropylene resin forms a continuous phase, and the polyphenylene ether-based resin forms a dispersed phase.
n), the ratio between the weighted average particle wall distance (Lw) and Ln: Lw
An object of the present invention is to provide a resin composition characterized in that / Ln is 1.0 to 3.0, a molded article using the same, and a battery case for a secondary battery using the resin composition.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The polyphenylene ether resin used in the present invention is polyphenylene ether or
It is a mixture of polyphenylene ether and styrene resin. Here, the polyphenylene ether used in the present invention has the following general formula

[0010]

Embedded image

(Where Q¹Is a halogen atom, primary
Or a secondary alkyl group, aryl group, aminoalkyl
Group, hydrocarbonoxy group or halohydrocarbonoxy group
Then Q ^TwoAre hydrogen, halogen, primary or
Represents a secondary alkyl group, an aryl group, a haloalkyl group,
Represents a hydrogen oxy group or a halohydrocarbon oxy group, m is
Homopolymer having a structure represented by the following formula:
Or a copolymer. Q¹And Q^TwoPrimary alkyl group
Preferred examples of methyl, ethyl, n-propyl, n-butyl
Chill, n-amyl, isoamyl, 2-methylbutyl, n
-Hexyl, 2,3-dimethylbutyl, 2-, 3-if
Or 4-methylpentyl or heptyl. Second class
Preferred examples of the alkyl group are isopropyl, sec-butyl
Or 1-ethylpropyl. More preferably, Q¹
Is an alkyl group or a phenyl group, especially an alkyl group having 1 to 4 carbon atoms.
A kill group, Q^TwoIs a hydrogen atom. )
A homopolymer or copolymer having a structure.

A preferred homopolymer of polyphenylene ether is, for example, one comprising 2,6-dimethyl-1,4-phenylene ether unit. Further, a preferred copolymer is a random copolymer comprising a combination of the above unit and 2,3,6-trimethyl-1,4-phenylene ether unit. Many suitable homopolymers or random copolymers are described in various known documents and the like, and in the present invention, their use is not limited. For example, polyphenylene ether containing a molecular component for improving properties such as molecular weight, melt viscosity, and / or impact strength can also be suitably used. The polyphenylene ether used here preferably has an intrinsic viscosity at 30 ° C. of 0.2 to 0.8 dl / g measured in chloroform. More preferably, the intrinsic viscosity is 0.2 to 0.7 dl / g.
And particularly preferably 0.25 to 0.6 d
1 / g. If the intrinsic viscosity is less than 0.2 dl / g, the impact resistance of the composition will be insufficient, and if it exceeds 0.8 dl / g, the moldability will be unsatisfactory.

The styrene resin used in the present invention is preferably polystyrene or rubber-reinforced polystyrene. The amount of these components is 0% when the total of polyphenylene ether and these styrene resins is 100% by weight.
~ 80% by weight is preferred. If it exceeds 80% by weight, heat resistance is undesirably reduced too much.

The crystalline polypropylene resin used in the present invention is a crystalline resin mainly containing propylene as a structural unit, specifically, a propylene homopolymer or propylene as a main component, which is mixed with ethylene, butene-
And copolymers with α-olefins such as 1, hexene-1, heptene-1, and 4-methylpentene-1. This copolymer may be a random copolymer or a block copolymer, but a poly-
A block copolymer having a form in which α-olefin domains are dispersed is more preferable. Among them, propylene homopolymer and propylene / ethylene block copolymer are particularly preferable. The density of the propylene homopolymer portion of polypropylene in the resin is preferably a value measured by JIS K7112 is 0.906 g / cm ³ or more, more preferably 0.907 g / cm ³ or more, especially preferably 0.908 g / cm ³ or more. By using one having a density of 0.906 g / cm ³ or more, mechanical strength, heat resistance, and steam barrier properties are further improved. Further, those having a density exceeding 0.935 g / cm ³ are not preferable because of difficulty in production.

Here, the density of the polypropylene resin is measured in the case of a propylene homopolymer by molding a predetermined test piece by compression molding or injection molding of the polypropylene resin, and using the test piece according to JIS.
It can be determined according to the K7112 underwater substitution method. In the case of a copolymer, a method of extracting a propylene homopolymer during polymerization and obtaining the same by the above method, or
The copolymer is extracted from the copolymer using a solvent such as hexane, and the density of the remaining propylene homopolymer is determined by the above method. The density of the propylene homopolymer portion in the entire composition can be determined by extracting the composition using a good solvent of polyphenylene ether such as chloroform and remaining propylene resin by the above method.

Such a polypropylene resin is produced by a method of obtaining a polypropylene resin having the density by polymerization, a method of increasing the density by adding a nucleating agent to a polypropylene resin having a density lower than the density, and obtaining a polypropylene resin of the density. can do.

The nucleating agent used here may be any as long as it improves the crystallinity of the polypropylene resin.
Representative examples include metal nucleating agents such as metal salts of aromatic carboxylic acids, sorbitol derivatives, organic phosphates, aromatic amide compounds, and inorganic nucleating agents such as talc. It is not limited to these. The melt flow rate of these polypropylene resins (JIS
Measurement based on K7210; 230 ° C, 21.17 N load) is preferably in the range of 0.1 to 10 g / 10 min, more preferably in the range of 0.2 to 8 g / 10 min,
Particularly preferably, it is in the range of 0.3 to 6 g / 10 min. The melt flow rate is 0.1 g / 10 min
If it is less than 10, the moldability is insufficient, and if it is more than 10 g / 10 min, the mechanical strength is unsatisfactory.

In the present invention, in order to improve the impact strength, a vinyl aromatic compound polymer block A is used.
And a hydrogenated product of a block copolymer comprising a conjugated diene compound polymer B. The block copolymer referred to here is a vinyl aromatic compound-conjugated diene block copolymer having a structure having at least one block B derived from a vinyl aromatic compound and at least one block B derived from a conjugated diene. The arrangement of the blocks A and B includes those having a linear structure, a branched structure, or a tapered structure. Further, a part of these structures may include a random chain derived from a random copolymer part of a vinyl aromatic compound and a conjugated diene. In the present invention, among these, those having a linear structure are preferable, and those having a triblock structure are more preferable. Further, the hydrogenated product of the block copolymer is a block copolymer in which the aliphatic unsaturated groups of the block B have been reduced by hydrogenation, and the proportion of the unsaturated bonds remaining without hydrogenation is as follows: It is preferably at most 20%, more preferably at most 10%, but is not particularly limited. Moreover, you may use together with the block copolymer which is not hydrogenated. The vinyl aromatic compound is preferably styrene, α-methylstyrene, paramethylstyrene, vinyltoluene, vinylxylene, and more preferably styrene. The conjugated diene is preferably 1,3-butadiene, isoprene, 2-methyl-1,3-butadiene.

Specific examples of the block copolymer include a styrene-butadiene-styrene block copolymer and a styrene-isoprene-styrene block copolymer, and a plurality of these may be used. The proportion of the repeating unit derived from the vinyl aromatic compound in the vinyl aromatic compound-conjugated diene block copolymer is preferably in the range of 50 to 85% by weight, more preferably in the range of 55 to 85% by weight, Particularly preferably, it is in the range of 60 to 80% by weight. By using a vinyl aromatic compound-conjugated diene block copolymer having a repeating unit derived from the vinyl aromatic compound in a proportion of 50 to 85% by weight, the polyphenylene ether-based resin and the polypropylene resin can be used. Compatibility is improved. These block copolymers and hydrogenated products thereof have a value of the toluene solution viscosity at 25 ° C. of 300
Those in the range of 00-10 cps are preferred, and more preferably in the range of 10,000-30 cps. 300
When the range is larger than 00 cps, there is a problem in molding processability of the final composition, and when the range is smaller than 10 cps, the mechanical strength level is low, which is not preferable.

Further, other components that can be added to the resin composition of the present invention as needed include, for example, well-known antioxidants, weather resistance improvers, nucleating agents, impact resistance improvers, and the like for thermoplastic resins. Plasticizers, flow improvers and the like can be used. Further, the addition of an organic filler, a reinforcing agent, and an inorganic filler such as glass fiber, talc, mica, kaolin, calcium carbonate, silica, and clay is effective in improving rigidity, heat resistance, dimensional characteristics, and the like. If necessary, various colorants and dispersants therefor can also be used. In the present invention, it is also preferable to add a flame retardant to impart flame retardancy. As the flame retardant used in the present invention,
Various known materials can be used and are not particularly limited, and the compounding amount is an amount required to obtain a target flame retardant level. Preferably, phosphorus system,
Halogen-based and inorganic flame-retardants, flame-retardant auxiliaries, and these can be used in combination. The amount used is 1 to 50 parts by weight based on 100 parts by weight of the resin component.

The composition ratio of each component described above is such that when the total amount of the polyphenylene ether-based resin and the polypropylene resin is 100 parts by weight, the polyphenylene ether-based resin is in the range of 5 to 60 parts by weight, preferably 10 to 50 parts by weight. In the range from 15 to 45 parts by weight, particularly preferably in the range from 40 to 95 parts by weight, preferably in the range from 50 to 90 parts by weight, particularly preferably in the range from 55 to 85 parts by weight. Range. If the polyphenylene ether-based resin is less than 5 parts by weight, heat resistance and rigidity are unsatisfactory. On the other hand, if the polyphenylene resin is less than 40 parts by weight, steam barrier properties and welding strength are unsatisfactory. The composition ratio of the hydrogenated product of the vinyl aromatic compound-conjugated diene copolymer is in the range of 1 to 30 parts by weight, preferably 3 to 30 parts by weight.
The range is from 25 to 25 parts by weight, particularly preferably from 5 to 20 parts by weight. If the amount of the hydrogenated vinyl aromatic compound-conjugated diene copolymer is less than 1 part by weight, the impact resistance is unsatisfactory, and if it exceeds 30 parts by weight, the heat resistance is unsatisfactory. Further, the ratio of the hydrogenated product of the polyphenylene ether-based resin and the vinyl aromatic compound-conjugated diene copolymer,
The weight ratio is preferably in the range of 1/1 to 10/1, more preferably 1.2 / 1 to 8/1, and particularly preferably 1.
4/1 to 6/1. By setting the proportion of the hydrogenated product of the polyphenylene ether-based resin and the vinyl aromatic compound-conjugated diene copolymer in this range, the balance between heat resistance and impact resistance becomes better.

In the present invention, the crystalline polypropylene resin forms a continuous phase, the polyphenylene ether-based resin forms a dispersed phase, and the average inter-particle wall distance (L) of the dispersed phase.
n) and weighted average particle wall distance (Lw): Lw / Ln
Is in the range of 1.0 to 3.0, preferably in the range of 1.0 to 2.0, and particularly preferably in the range of 1.0 to 1.5. Here, the average distance between particle walls (Ln) and the weighted average distance between particle walls (Lw) refer to values obtained by using the following equations.

That is, the average inter-particle wall distance (Ln)

[0024]

(Equation 1)

(Where L ₁ , L ₂ ,..., L _I represent the measured values of the distances between one, two,... I particle walls, respectively).

The weighted average particle wall distance (Lw) is:

[0027]

(Equation 2)

(Where L ₁ , L ₂ ,..., L _I represent the measured values of the distances between one, two,... I particle walls, respectively).

The ratio of the added average interparticle wall distance (Ln) to the weighted average interparticle wall distance (Lw) of the dispersed phase: Lw / Ln is 3.
If it exceeds 0, there is a large variation in welding strength, which is not preferable. In the present invention, the ratio between the average value (arithmetic average value) of the distance between the particle walls of the dispersed particles of the polyphenylene ether-based resin dispersed in the continuous phase of the polypropylene resin and the weighted average value is calculated. Let's look at the distribution of distances. The idea of observing the distribution by such an average value is known as a number average molecular weight (addition average) and a weight average molecular weight (weighted average) when calculating the molecular weight or molecular weight distribution of a polymer. It was applied to determine the distribution of the dispersed phase. The present invention relates to a blend of a polyphenylene ether-based resin and a polypropylene resin, where the polypropylene resin is a continuous phase, when a molded article using such a blend has a welded portion, and when the polypropylene resin is a continuous phase, Therefore, the larger the distance between the particle walls, the higher the welding strength tends to be. However, even if the distance between the particle walls is simply large, if the distribution (Lw / Ln) is large, the variation in welding strength is large, and if the distribution (Lw / Ln) is small, the variation in welding strength is small, which is preferable. This has been found by the present inventors. In the present invention, the dispersed phase for determining Lw / Ln refers to a dispersed phase formed of a polyphenylene ether-based resin, and only a hydrogenated product of a vinyl aromatic compound-conjugated diene copolymer is dispersed in a polypropylene resin. This does not include any phase formation.

The hydrogenated product of the vinyl aromatic compound-conjugated diene copolymer exists mainly at the interface between the crystalline polypropylene resin and the polyphenylene ether resin. Of the hydrogenated product of the vinyl aromatic compound-conjugated diene copolymer, the proportion present at the interface between the polypropylene resin and the polyphenylene ether-based resin is preferably 50% by weight or more, more preferably 60% by weight or more, It is particularly preferably at least 70% by weight.

Here, the form of the resin composition of the present invention can be confirmed using a transmission electron microscope. Specifically, an ultrathin section is cut out from a test piece prepared using the resin composition of the present invention using an ultramicrotome, and this section is stained with ruthenium tetroxide, observed with a transmission electron microscope, and photographed. . This photograph was taken into a computer using a scanner, the distance between the particle walls of the dispersed particles was determined using software such as Luzex manufactured by NIRECO, and the average was calculated from the obtained distance between the particle walls (I = 500). Let Ln be the distance between the particle walls and Lw be the distance between the particle walls determined by the weighted average.

As a method for obtaining the resin composition of the present invention, the above components are kneaded with various kneaders, for example, a single-shaft and multi-shaft kneader, a Banbury mixer, a roll mill, a Brabender plastogram, and the like, and then cooled. The solidification method and the addition of the above components to an appropriate solvent, for example, hydrocarbons such as hexane, heptane, benzene, toluene, and xylene, and derivatives thereof, and dissolving the components, or dissolving and insoluble components, are performed. A solution mixing method of mixing in a turbid state is used. The melt kneading method is preferable from the industrial cost, but is not limited thereto. Among them,
In order to obtain a form as defined in the present invention, it is preferable to perform melt kneading using a twin screw extruder, and particularly knead so that the residence time represented by the following formula is 5 to 100 seconds. It is more preferable that the kneading be performed so that the residence time is 10 to 80 seconds.

[0033]

## EQU3 ## Residence time (sec) = V × ρ × φ ÷ Q

(Where V is the spatial volume (cm ³ ) of the kneading disk portion, and ρ is the melt density of the resin (g / c).
m ³ ) and φ represent the filling rate (−) of the kneading disk portion, and Q represents the discharge rate (g / sec). The method for obtaining a molded article using the resin composition of the present invention is not particularly limited, and molding methods generally used for thermoplastic resin compositions, such as injection molding, hollow molding, extrusion molding, and sheeting Molding methods such as molding, thermoforming, rotational molding and lamination molding can be applied.

The pressure vessel referred to in the present invention is a vessel to which an internal pressure exceeding 0.1 MPa is applied at the time of use. In the present invention, a pressure vessel having an internal pressure of 0.2 MPa or more at the time of use is particularly preferable. The effect is exhibited, and the effect is further remarkable in a pressure vessel whose internal pressure during use is 0.3 MPa or more. As a specific example of such a pressure vessel,
For example, a pump case, a battery case for a sealed secondary battery, and the like can be given.

Further, the present invention is highly effective in a molded article having a welded portion, and in particular, in a pressure vessel comprising two or more parts, and these parts are welded.
Expresses a remarkable effect. The two or more parts here are, for example, a container body and a lid. Welding here means
This is a step of melting and joining the parts together, and the method is not particularly limited. In addition to the above-described hot plate welding, vibration welding, ultrasonic welding, and the like, two or more parts are placed in a mold. Can be used. The welding conditions are not particularly limited, but the welding part surface temperature at the time of welding is preferably 170 to 340 ° C, more preferably 190 to 320 ° C, and particularly preferably 190 to 300 ° C. .

In the present invention, from the characteristics of the resin composition and the molded article using the same, as a battery case for a secondary battery, particularly as a battery case for a sealed secondary battery (for example, a battery case body and a lid). Suitable for use. The secondary battery is a battery that can be repeatedly charged and discharged, and examples thereof include a lead storage battery, a Ni-cadmium battery, a Ni-hydrogen battery, and a Li-ion battery. In the present invention, the battery case is not only a battery case body containing a positive electrode material, a negative electrode material, an electrolytic solution, and a power generating element formed of a separator, but also a lid for sealing or closing an opening thereof. , Also means the parts attached to the battery case. When there are a plurality of parts, not all of them need to be the resin composition or the molded article of the present invention. The present invention is suitable for use in a battery case for a sealed secondary battery. As a use of such a battery, there is a use for a video tape recorder, a clock, and the like, but a drive power supply of an electric vehicle is particularly suitable. FIGS. 1, 2, and 3 are schematic diagrams of examples of a secondary battery to which the present invention is applied.
The present invention is not limited to them. That is,
FIG. 1 shows a battery case lid 2 provided with a battery case body 1 and a cathode terminal portion 3 and an anode terminal portion 4. The main body 1 and the lid 2
Is welded by heat welding or the like. FIG. 2 shows the battery case body 1.
And an inner cover 2 provided with an electrode terminal portion 4 and an outer cover 3 provided so as to cover the electrode terminal portion 4. The main body 1 and the inner cover 2, and the inner cover 2 and the outer cover 3 are thermally heated. It is welded by welding or the like. However, the inner lid and the outer lid may be bonded with an adhesive resin or the like. Further, FIG. 3 shows a collective sealed secondary battery, in which a plurality of unit cells A as shown in FIGS. 1 and 2 are arranged in series, these are restrained by a restraining band 4 or the like, and the unit cells are joined. This is shown. Such an assembly type battery case is not limited to the one molded for each unit cell, but may be an integrally molded product, and the shape is not limited. FIG. 3 shows a structure in which the electrode terminals 3 are provided on the integrally formed lid 2. However, it is necessary that each cell be electrically connected.

[0038]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Each component used in the following examples is as shown below. 1. Polyphenylene ether (PPE) PPE-1: poly-2,6-dimethyl-1,4-phenylene ether (manufactured by Mitsubishi Engineering-Plastics Corporation, intrinsic viscosity measured at 30 ° C. chloroform: 0.40 dl / g) PPE-2: poly-2,6-dimethyl-1,4-phenylene ether (manufactured by Mitsubishi Engineering-Plastics Corporation, intrinsic viscosity measured at 30 ° C. chloroform: 0.50 dl / g) PPE-3: poly-2,6-dimethyl-1,4-phenylene ether (manufactured by Mitsubishi Engineering-Plastics Corporation, having an intrinsic viscosity of 0.30 dl / g when measured in chloroform at 30 ° C.) thing)

2. Polystyrene (PS) A & M Styrene Co., Ltd. Product name: HT
478 (rubber reinforced polystyrene) Crystalline polypropylene resin (PP) PP-1: polypropylene homopolymer, MFR 0.5 g
/ 10 min, density 0.909 g / cm ³ PP-2: polypropylene homopolymer, MFR 1.0 g
/ 10 min, density 0.904 g / cm ³ PP-3: polypropylene homopolymer, MFR 20 g /
3. 10 min, density 0.905 g / cm ³ Hydrogenated product of vinyl aromatic compound-conjugated diene block copolymer (SEPS) SEPS-1: manufactured by Kuraray Co., Ltd., trade name: Septon 21
04 (hydrogenated styrene-isoprene-styrene copolymer, styrene content 65% by weight) SEPS-2: manufactured by Kuraray Co., Ltd., trade name: SEPTON 40
77 (hydrogenated styrene-isoprene-styrene copolymer, styrene content 30% by weight)

[Examples 1 to 6, Comparative Examples 1, 2, 6 to 9]
The resin components shown in Table 1 below were melt-kneaded using a 44 mm twin-screw extruder (manufactured by Nippon Steel Works) at a cylinder temperature of 230 ° C., a screw rotation speed of 250 rpm, and a residence time of 30 seconds to obtain a resin composition. . Next, this resin composition was injection molded using an injection molding machine (manufactured by Nippon Steel Works, mold clamping force 55T) under conditions of a cylinder temperature of 260 ° C. and a mold temperature of 40 ° C. to form a molded product. Was evaluated by the following method. [Comparative Example 3] The resin components shown in Table 1 below were used at a cylinder temperature of 2 using a 44 mm twin screw extruder (manufactured by Nippon Steel Works).
Melt kneading was performed at 30 ° C., a screw rotation speed of 250 rpm, and a residence time of 4 seconds to obtain a resin composition. Next, this resin composition was injection molded using an injection molding machine (manufactured by Nippon Steel Works, mold clamping force 55T) under conditions of a cylinder temperature of 260 ° C. and a mold temperature of 40 ° C. to form a molded product. Was evaluated by the following method.

[Comparative Example 4] Using a 44 mm twin-screw extruder (manufactured by Nippon Steel Works), the resin component was heated to a cylinder temperature of 230.
The mixture was melt-kneaded at a temperature of 250 ° C., a screw rotation speed of 250 rpm, and a residence time of 180 seconds to obtain a resin composition. Next, this resin composition was injection molded using an injection molding machine (manufactured by Nippon Steel Works, mold clamping force 55T) under conditions of a cylinder temperature of 260 ° C. and a mold temperature of 40 ° C. to form a molded product. Was evaluated by the following method. [Comparative Example 5] A resin component was melt-kneaded using a 40 mm single screw extruder (manufactured by Tanabe Seisakusho) at a cylinder temperature of 230 ° C and a screw rotation speed of 50 rpm to obtain a resin composition. Next, this resin composition was injection molded using an injection molding machine (manufactured by Nippon Steel Works, mold clamping force 55T) under conditions of a cylinder temperature of 260 ° C. and a mold temperature of 40 ° C. to form a molded product. Was evaluated by the following method. (Evaluation method) (1) Izod impact test A notched Izod impact test was performed according to ASTM D256. (2) Flexural Modulus A three-point bending test was performed according to a bending test method according to ASTM D790. (3) Heat deformation temperature According to ASTM D648, under the condition of 1.82 MPa,
A load deflection test was performed. (4) Chemical resistance In a state where 1% bending strain was given to the test piece obtained by injection molding, gasoline was applied to the maximum strained part, and the surface condition after being left for 48 hours was observed and visually observed. Judgment was made. Evaluation method ○: No change, ×: Cracked (5) Density of used polypropylene resin When the polypropylene resin is propylene homopolymer,
The polypropylene resin as it is, or in the case of a propylene-ethylene block copolymer, is withdrawn when the propylene homopolymer is polymerized, and the propylene homopolymer portion is heated at a cylinder temperature of 220 ° C. and a mold temperature of 40 ° C., Injection molding was performed to obtain an Izod test piece. Using the test piece, the density at 23 ° C. was determined from the mass in air and the mass in water according to JIS K7112 underwater replacement method.

[0042]

Ρ = K · a / (ab)

(Where ρ represents the density of the sample (g / cm ³ ), K represents the density of water (g / cm ³ ), a represents the weight (g) of the sample in air, b Represents the mass (g) of the sample in water.)

(6) Welding strength The above composition was mixed with an injection molding machine (manufactured by Nippon Steel Works, mold clamping force 5
0T), cylinder temperature 250 ° C, mold temperature 60
A test piece having a thickness of 12.7 mm × 127 mm and a thickness of 2 mm was prepared at a temperature of ° C. The 12.7 mm surface of the test piece was
The plate was brought into contact with a hot plate set at 85 ° C. under a load of 3 N for 20 seconds.
Welding was performed by pressing for 0 seconds. The obtained welding test piece was pulled at a tensile speed of 10 mm / min using an Instron.
, And the breaking strength was measured to determine the welding strength. At this time, the test was performed with the number of tests n = 10, and the average value,
And "maximum value-minimum value" as an index of variation,
Table 1 shows the results. (7) Distance between the dispersed particle walls Using an ultramicrotome from the center of the tensile test specimen, cut out the ultrathin section perpendicular to the flow direction at the center of the thickness, stain this section with ruthenium tetroxide, and use a transmission type Observed with an electron microscope, photographed at 5,000 times, 10,000
You got a doubled photo. This photograph was taken into a computer using a scanner, and the shortest distance between particles of the dispersed particles (the shortest distance between the particle walls) was obtained from the index of “NEAR D” using Luzex manufactured by NIRECO, and the obtained particle wall was obtained. From the distance (I = 500), the distance between the particle walls determined by the addition average was Ln, and the distance between the particle walls determined by the weighted average was Lw, and Lw / Ln was determined.

[0045]

[Table 1]

[0046]

The resin composition obtained according to the present invention and the resin molded article using the same are excellent in strength and heat resistance, so are excellent in deformation under temperature and load environment, and are resistant to chemicals. It is excellent in safety when oil adheres. Further, since it has excellent welding strength and its stability, it has excellent strength in products. Therefore, the present invention satisfies the strict performance required for a pressure vessel such as a sealed secondary battery case.

[Brief description of the drawings]

FIG. 1 is an example of a schematic view of a battery case for a secondary battery as an example of use of the resin molded article of the present invention.

[Explanation of symbols]

1. Battery case body, 2. 2. Lid for battery case, 3. cathode terminal part; Anode terminal

FIG. 2 is an example of a schematic view of a battery case for a secondary battery which is an example of use of the resin molded article of the present invention.

[Explanation of symbols]

1. Battery case body, 2. 2. internal lid; 3. external lid; Electrode terminal

FIG. 3 is an example of a schematic view of a battery case for a collective secondary battery which is an example of use of the resin molded article of the present invention.

[Explanation of symbols]

A. Cell, 1. 1. Integrated battery case body; 2. integrated lid,
3. electrode terminal; Restraint band

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C08L 71/12 C08L 71/12 H01M 2/02 H01M 2/02 AL (72) Inventor Naoto Obayashi Higashi-Hachiman, Hiratsuka-shi, Kanagawa 5-6-2 Mitsubishi Engineering Plastics Co., Ltd. Technical Center F-term (reference) 3E033 AA09 BA16 BA30 BB01 CA03 CA07 CA11 DD01 FA02 4F071 AA12 AA12X AA15 AA15X AA20 AA20X AA21 AA21X AA22 AA22X AA51 A04B05A05 BB12W BB14W BB15W BP01Y BP02W CH07X GG01 5H011 AA01 AA02 BB03 CC02 CC09 KK00

Claims (10)

[Claims] 1. A polyphenylene ether resin 5 to 60.
In a resin composition containing 1 to 30 parts by weight of a hydrogenated product of a vinyl aromatic compound-conjugated diene copolymer with respect to 100 parts by weight of a total of 100 parts by weight of a crystalline polypropylene resin and 40 to 95 parts by weight of a crystalline polypropylene resin, The resin forms a continuous phase, and the polyphenylene ether-based resin forms a dispersed phase,
The ratio of Ln / Ln to the average distance between the added particle walls (Ln), the weighted average distance between the particle walls (Lw) and Ln of the dispersed phase is 1.0 to 1.0.
3.0, which is 3.0. 2. The resin composition according to claim 1, wherein Lw / Ln is 1.0 to 2.0. 3. The hydrogenated product of a vinyl aromatic compound-conjugated diene copolymer contains 50 to 8 vinyl aromatic compound units.
The resin composition according to claim 1, comprising 5% by weight. 4. The weight ratio of the hydrogenated product of the polyphenylene ether resin and the vinyl aromatic compound-conjugated diene copolymer is from 1/1 to 10/1 by weight. The resin composition according to any one of the above. 5. The resin composition according to claim 1, wherein the density (ρ) of the propylene homopolymer portion in the polypropylene resin is 0.906 g / cm ³ or more. 6. A resin molded article using the resin composition according to any one of claims 1 to 5. 7. The resin molded article according to claim 6, wherein the molded article is a pressure vessel. 8. The resin molded article according to claim 6, which includes a welded portion. 9. The resin molded article according to claim 6, wherein the pressure vessel applies an internal pressure of 0.2 MPa or more during use. 10. A battery case for a secondary battery, formed by using the resin composition according to claim 1.