JP2002260604A - Resinous composition molded to secondary battery jar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery jar material which keeps water-vapor resistant permeability, a heat-resistant creep property, and an impact-resistant property. SOLUTION: This resinous composition includes at least one kind of components (1) to (4), namely (1) a specified molecular weight of a hydrogenated block copolymer, (2) high density polyethylene and the hydrogenated block copolymer, (3) the high density polyethylene and a crystalline hydrogenated block copolymer, and (4) polyphenylene ether and the hydrogenated block copolymer, with respect to 100 pts.wt. of polypropylene resin that is not less than 0.905 g/cm<3> in the density of a propylene copolymer, and is 0.1 to 12 in MFR.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition which is molded as a secondary battery case (including a closed type secondary battery case) and has excellent heat creep characteristics, water vapor permeability and impact resistance. It is about.

[0002]

2. Description of the Related Art Lead-acid batteries, nickel-cadmium batteries,
Secondary batteries (including sealed type secondary batteries) known as nickel-hydrogen batteries are widely used as power sources for various electric products and industrial equipment, mainly in vehicles such as automobiles. It is getting bigger. Along with this demand, the performance of the battery body has also improved, and the battery case itself has been reduced in size and weight and the electric capacity has been increased.
Conversion to resin materials that can withstand shape changes such as thinner and lighter weight is required, and resin materials with excellent mechanical strength, water vapor permeability and heat resistance are required to improve battery performance. I have.

Conventionally, as a resin battery case made of a resin,
For example, ABS resin and modified polyphenylene ether resin have been used from the viewpoint of moldability and heat resistance. However, these resins have a drawback that they are inferior in water vapor permeability, and electrolytes present in secondary batteries and separators exist. Since the moisture permeates the battery case of the secondary battery during long-term use, there is a fatal problem that the concentration of the electrolyte changes and the battery performance deteriorates. Further, these ABS resins and modified polyphenylene ether resins have poor chemical resistance and poor resistance to chemicals such as automobile oils, and thus have a drawback that they cannot be used for a long time in secondary battery cases for automobiles.

In view of these problems, a sealed secondary battery case made of a resin composition containing a crystalline polyolefin resin and a polyphenylene ether resin has been disclosed in Japanese Patent Application Laid-Open No. Hei 8-1951.
No. 88, Japanese Patent Application Laid-Open No. 9-120801 proposes a sealed secondary battery case using a polymer alloy comprising a polyphenylene ether resin and a polyolefin resin, and further disclosed in WO97 / 01600. Is composed of a crystalline polyolefin resin and a polyphenylene ether resin, and a resin composition in which the polyphenylene ether resin is dispersed in a specific form in a crystalline polypropylene resin is excellent in heat creep resistance and water vapor permeability. JP-A-2000-58007 proposes that a resin composition comprising a polyphenylene ether-based resin and a crystalline polypropylene having a specific structure can be used as a battery case for a sealed secondary battery. ing.

A resin composition for a battery case made of a crystalline polypropylene resin is disclosed in JP-A-6-2873.
Japanese Patent Application Laid-Open No. H64-64 proposes that the resin is made of a polypropylene resin and talc having a specific particle size and has a small amount of shrinkage deformation after molding. Japanese Patent Application Laid-Open No. 8-132468 discloses a polypropylene storage battery comprising a polypropylene resin and a small amount of talc. A battery case has been proposed, and JP-A-11-31483 discloses that at least 95% by weight of polypropylene and the remainder are composed of a propylene-ethylene copolymer, and the crystallinity is 55%.
A sealed electrochemical battery case made with a composition of about 65% was proposed.
In Japanese Patent Application Publication No. 2000-133, there is proposed a battery case material excellent in transparency, in which propylene, an α-olefin block copolymer and an ethylene / α-olefin copolymer are blended. However, the secondary battery case obtained with these resin compositions has many components other than the crystalline polypropylene added at the time of polymer alloying, and maintains the excellent water vapor permeability resistance of the crystalline polypropylene at a high level. It was difficult to do.

[0006]

The problem to be solved by the present invention is as follows.
A material that maintains the high level of water vapor transmission resistance and heat creep resistance of crystalline polypropylene alone and overcomes the brittleness that is a disadvantage when a secondary battery battery case is made of a high crystalline polypropylene resin alone as a component To provide.

[0007]

DISCLOSURE OF THE INVENTION In order to solve the above-mentioned problems, the present invention has been made as a result of intensive studies on the dispersed phase component of a resin composition whose matrix is a polypropylene resin, and as a result, a crystalline polypropylene having a specific density and MFR has been obtained. (1) dispersing a hydrogenated block copolymer having a specific molecular weight in a matrix polypropylene; (2) dispersing a hydrogenated block copolymer in a matrix polypropylene using a high-density polyethylene and a hydrogenated block copolymer; (3) using high-density polyethylene and a crystalline hydrogenated block copolymer to be dispersed in a matrix polypropylene;
(4) The present inventors have found that the above problems can be solved by dispersing polyphenylene ether and a hydrogenated block copolymer in a matrix polypropylene, and have accomplished the present invention.

That is, according to the present invention, (a) a propylene polymer portion having a density of 0.905 g / cm ³ or more and an MFR
The resin component forming the dispersed phase is (1) (b) at least two polymer blocks mainly composed of a vinyl aromatic compound with respect to a matrix phase of 100 parts by weight of a polypropylene resin having a molecular weight of 0.1 to 12. A is obtained by hydrogenating a block copolymer comprising A and at least one polymer block B mainly comprising a conjugated diene compound, wherein the amount of the vinyl aromatic compound is 20 to 70% by weight, and 0.5 to 15 parts by weight of a hydrogenated block copolymer having a number average molecular weight of not less than 100,000 as measured in terms of polystyrene by using an application chromatography (GPC),
(2) 1 to 30 parts by weight of (c) a high-density polyethylene having a density of 0.940 g / cm ³ or more, and (d) at least one polymer block A mainly composed of a vinyl aromatic compound and a conjugated diene compound And a hydrogenated block copolymer obtained by hydrogenating a block copolymer comprising at least one polymer block B mainly composed of (3) (c) 1 to 30 parts by weight of a high-density polyethylene having a density of 0.940 g / cm ³ or more;
Hydrogenated block copolymer having a crystalline melting point of 0 ° C. or higher
25 to 15 parts by weight, (4) (f) 1 to 10 parts by weight of polyphenylene ether, and (d) at least one polymer block A mainly composed of a vinyl aromatic compound and at least one mainly composed of a conjugated diene compound. And the amount of the vinyl aromatic compound is 20 to 7
0.25 to 10 parts by weight of a hydrogenated block copolymer obtained by hydrogenating a block copolymer of 0% by weight contains at least one of the components (1) to (4). 4) When two or more components are contained, the total amount does not exceed 50 parts by weight.

Hereinafter, the present invention will be described in detail. The polypropylene resin (a) used in the present invention exhibits density and MFR (melt flow rate) from the characteristics of the polypropylene resin in a broad sense in order to exhibit the heat creep resistance and the water vapor permeability resistance of the present invention. ) Is limited to a specific range. Generally, the polypropylene-based resin comprises a crystalline propylene homopolymer and a crystalline propylene homopolymer portion obtained in the first step of polymerization and propylene, ethylene and / or at least one other α-olefin ( For example, a crystalline propylene-ethylene block copolymer having a propylene-ethylene random copolymer portion obtained by copolymerizing butene-1, hexene-1 and the like can be mentioned. Furthermore, there may be a mixture of these crystalline propylene homopolymer and crystalline propylene-ethylene block copolymer, and such a crystalline propylene-ethylene block copolymer usually has an ethylene content of 1 to 30.
% By weight.

The method for producing the polypropylene resin is usually carried out at a polymerization temperature of 0 to 100 ° C. in the presence of a titanium halide catalyst or the like supported on a carrier such as a titanium trichloride catalyst or magnesium chloride and an alkylaluminum compound. And a polymerization pressure of 3 to 100 atm. At this time, it is also possible to add a chain transfer agent such as hydrogen to adjust the molecular weight of the polymer, and it is also possible to use a batch method or a continuous method as a polymerization method, butane, pentane, hexane, heptane A method such as solution polymerization or slurry polymerization in a solvent such as octane or octane can also be selected, and a bulk polymerization in a monomer without a solvent, a gas phase polymerization in a gaseous monomer, and the like can be applied.

In addition to the above-mentioned polymerization catalyst, an electron-donating compound can be used as an internal donor component or an external donor component as a third component in order to increase the isotacticity and polymerization activity of the obtained polypropylene. As these electron donating compounds, known compounds can be used, for example, ester compounds such as ε-caprolactone, methyl methacrylate, ethyl benzoate, and methyl toluate; and triphenyl phosphite and tributyl phosphite. Phosphoric acid derivatives such as phosphoric acid esters and hexamethylphosphoric triamide, alkoxy ester compounds, aromatic monocarboxylic acid esters and / or aromatic alkyl alkoxy silanes, aliphatic hydrocarbon alkoxy silanes, various ether compounds, various alcohols And / or various phenols.

The density of the propylene polymer portion in the polypropylene resin used in the present invention is as follows:
0.905 g / cm ³ from the viewpoint of improving water vapor transmission resistance
Or more, more preferably 0.905 to 0.925
g / cm ³ , most preferably 0.905 to 0.5 g / cm ³ .
It is 915 g / cm ³ . The density is 0.905 g /
If it is less than ³ cm ³ , the obtained battery case material has low rigidity, poor heat resistance creep, and is not preferable in terms of water vapor permeability.

The method of measuring the density of the propylene polymer portion can be easily determined by the JIS K-7112 water substitution method. When the polypropylene resin is a copolymer with an α-olefin containing propylene as a main component, the copolymer component is extracted from the copolymer using a solvent such as hexane, and the remaining propylene polymer portion is extracted. The density was determined by the above-mentioned JIS K-7112 water displacement method.
It can be easily obtained. In order to determine the density of the propylene polymer portion in the resin composition, the entire composition is dissolved with hot xylene, cooled to room temperature, and the resin composition remaining as a residue is subjected to a hydrogenated block copolymer such as chloroform. The propylene polymer portion is extracted from the remaining polypropylene-based resin by the above-mentioned separation method, and can be determined by the JIS K-7112 underwater substitution method.

In the present invention, it is also effective to add a known nucleating agent to increase the density of the polypropylene resin. Any crystal nucleating agent may be used as long as it improves the crystallinity of the polypropylene resin, but typical examples include metal salts of aromatic carboxylic acids, sorbitol derivatives, organic phosphates, aromatic amide compounds, and the like. Organic nucleating agent and inorganic nucleating agent such as talc. However, it is not limited to these.

Further, the polypropylene resin used in the present invention has an MFR (according to JIS K-6758) of 0.1 from the viewpoint of improvement in heat creep resistance and water vapor permeability.
-12, preferably 0.1-10, most preferably 0.1-5. If the MFR is less than 0.1, the moldability of the battery case material is poor, and the MF
When R is 12 or more, molding workability is improved, but heat creep performance and impact resistance are deteriorated, which is not preferable.

As long as the density and MFR of the crystalline polypropylene resin, which are the characteristics described above, are as described above, the resin may be obtained by any production method. In addition, such a crystalline polypropylene-based resin, in addition to the above-mentioned crystalline polypropylene-based resin, can be obtained by excluding the crystalline polypropylene-based resin and an α, β-unsaturated carboxylic acid or a derivative thereof in the presence of a radical generator. Known denaturation obtained by reacting under a temperature of 80 to 300 ° C. in a molten state, a solution state, or a slurry state (the α,
β-unsaturated carboxylic acid or its derivative is 0.01 to 1
0% by weight (graft or addition) crystalline polypropylene resin, or a mixture of the above-mentioned crystalline polypropylene resin and the modified crystalline polypropylene resin in any ratio.

Next, the components (1) to (4) forming the dispersed phase of the resin composition of the present invention will be described in detail. (B) at least two polymer blocks A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound, which are used as the component (1) forming the dispersed phase of the present invention; Block copolymer (hereinafter abbreviated as “hydrogenated block copolymer”) obtained by hydrogenating a block copolymer consisting of: is used as a secondary battery case (including a closed type secondary battery case). Creep strength of
And for imparting impact resistance. The structure of the hydrogenated block copolymer of the component (b) is, for example,
ABA, ABAB, (AB-) _4- Si,
It is a hydrogenated block copolymer obtained by hydrogenating a block copolymer having a structure such as ABABA. Here, A means a polymer block mainly composed of a vinyl aromatic compound, B means a polymer block mainly composed of a conjugated diene compound, and the content of the vinyl aromatic compound in the polymer block A is at least. 70% by weight, and the content of the conjugated diene compound in the polymer block B is at least 70% by weight.

Incidentally, the hydrogenated block copolymer of the component (b) means that the olefinic unsaturated bond derived from the conjugated diene compound in the block copolymer having the above-mentioned structure is 40%.
% Or less, preferably 30% or less, more preferably 10%
It is a block copolymer reduced by a hydrogenation reaction to the following. In addition, the polymer block A mainly composed of a vinyl aromatic compound and the polymer block B mainly composed of a conjugated diene compound are used for the distribution of the conjugated diene compound or the vinyl aromatic compound in the molecular chain in each polymer block. May be random, tapered (the monomer component increases or decreases along the molecular chain), partially block-shaped or any combination thereof, and two or more polymer blocks mainly containing the vinyl aromatic compound; The number of the polymer blocks mainly composed of the conjugated diene compound is one or more, and the respective polymer blocks may have the same structure or different structures.

The vinyl aromatic compound constituting the block copolymer is, for example, one or more of styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, diphenylethylene and the like. It can be selected, and styrene is particularly preferred. And
The content of the vinyl aromatic compound in the hydrogenated block copolymer used as the component (b) is 20 to 70% by weight, preferably 25 to 60% by weight, and more preferably 30 to 50% by weight.

When the amount of the vinyl aromatic compound is less than 20% by weight, the rigidity of the battery case is lowered, and it is not preferable. When the amount exceeds 70% by weight, the brittleness of the battery case is not overcome. On the other hand, as the conjugated diene compound constituting the block copolymer, for example, butadiene,
One or more of isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and the like are selected, butadiene, isoprene and a combination thereof are particularly preferred.

The polymer block mainly composed of a conjugated diene compound can have any desired microstructure. For example, in a polymer block mainly composed of butadiene, a 1,2-vinyl bond has a 1,2-vinyl bond. 2-8
5%, preferably 10-85%, more preferably 35%
~ 85%. In the polymer block mainly composed of isoprene, the total amount of 1,2-vinyl bonds and 3,4-vinyl bonds is 2 to 85%, more preferably 3 to 85%.
70%.

The hydrogenated block copolymer used as the component (b) must have a specific molecular weight as a material for a secondary battery case, in addition to the above structure. Such a specific molecular weight means that the number average molecular weight measured by gel permeation chromatography (GPC) in terms of polystyrene must be 100,000 or more. When the molecular weight is less than 100,000, the impact resistance as a material for a secondary battery container is low, and it is necessary to incorporate a very large number of hydrogenated block copolymers in order to enhance the impact resistance. It is not preferable because the water vapor transmission resistance and the heat creep resistance as a tank material are remarkably deteriorated. In other words, the hydrogenated block copolymer of component (b) having a specific molecular weight used in the present invention can impart a large amount of a crystalline polypropylene resin as a matrix component to impart excellent impact resistance in a small amount. This is an important effect that makes it possible to maintain a high level of water vapor transmission resistance and heat creep resistance as a secondary battery container material.

The hydrogenated block copolymer used as the component (b) used in the present invention may be obtained by any production method as long as it has the above-mentioned characteristics. The hydrogenated block copolymer used as the component (b) used in the present invention may be, in addition to the above-mentioned hydrogenated block copolymer, the hydrogenated block copolymer and α, β-
A known modification obtained by reacting an unsaturated carboxylic acid or a derivative thereof in a molten state, a solution state, or a slurry state in the presence or absence of a radical generator at a temperature of 80 to 350 ° C (the α, The β-unsaturated carboxylic acid or its derivative may be 0.01 to 10% by weight of a grafted or added) hydrogenated block copolymer, and the above-mentioned hydrogenated block copolymer and the modified hydrogenated block copolymer may be further used. It may be a mixture of any ratio of the coalescence.

The preferred amount of the hydrogenated block copolymer used as the component (b) is 0.5 to 15 parts by weight.
Preferably it is 1 to 10 parts by weight, more preferably 1 to 7 parts by weight. If it is less than 0.1, the improvement of the impact resistance is not remarkable, and if it exceeds 15 parts by weight, the improvement of the impact resistance can be expected, but the water vapor transmission resistance and the heat creep resistance as the battery case material of the secondary battery deteriorate. But not preferred.

Next, the high-density polyethylene (c) used as the component (2) for forming the dispersed phase of the present invention has a function of forming a dispersed phase of the resin composition of the present invention and imparting impact strength. It is a polymer or a copolymer of ethylene and an α-olefin. Such α-olefins include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like. The α-olefin content in the ethylene / α-olefin copolymer is 10 mol% or less, preferably 0.2 to 7%.
Mol%. The high-density polyethylene has a density (A
STM D 1505) is 0.940 g / cm ³ or more, and the melt flow rate (MFR: ASTM D 123)
8, 190 ° C, load 21.2N) is usually 0.01 to 50
g / 10 minutes, preferably 0.1 to 30 g / 10 minutes, and more preferably 0.1 to 20 g / 10 minutes. Such a high-density polyethylene can be produced by a medium-pressure method such as a low-pressure method using a Ziegler-Natta catalyst, a low-pressure method using a metallocene catalyst, or a Phillips method.

The preferred amount of the high density polyethylene used as the component (c) is 1 to 30 parts by weight, preferably 1 to 15 parts by weight, more preferably 1 to 7 parts by weight. If the amount is less than 1 part by weight, the improvement of the impact resistance is not remarkable, and if the amount exceeds 30 parts by weight, the improvement of the impact resistance can be expected, but the water vapor transmission resistance and the heat creep resistance as a secondary battery battery case material deteriorate. But not preferred. Further, (2) of the present invention
(D) A hydrogenated block copolymer comprising at least one polymer block A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound, Hydrogenated block copolymer (hereinafter abbreviated as hydrogenated block copolymer)
The above-mentioned component (2) (c) high-density polyethylene is suitably finely dispersed in (a) a polypropylene resin that forms a matrix phase, and a secondary battery case (including a sealed secondary battery case). It is necessary for imparting creep strength at high temperatures as well as impact resistance.

The structure of the hydrogenated block copolymer of the component (d) is, for example, AB, ABA, ABA-
It is a hydrogenated block copolymer obtained by hydrogenating a block copolymer having a structure such as B, (AB-) _4- Si, ABAABA, or the like. Here, A means a polymer block mainly composed of a vinyl aromatic compound, B means a polymer block mainly composed of a conjugated diene compound, and the content of the vinyl aromatic compound in the polymer block A is at least. 70% by weight, and the content of the conjugated diene compound in the polymer block B is at least 70% by weight.

The hydrogenated block copolymer of the component (d) means that the olefinic unsaturated bond derived from the conjugated diene compound in the block copolymer having the above-mentioned structure is 40%.
% Or less, preferably 30% or less, more preferably 10%
It is a block copolymer reduced by a hydrogenation reaction to the following. In addition, the polymer block A mainly composed of a vinyl aromatic compound and the polymer block B mainly composed of a conjugated diene compound are used for the distribution of the conjugated diene compound or the vinyl aromatic compound in the molecular chain in each polymer block. May be random, tapered (the monomer component increases or decreases along the molecular chain), partially block-shaped or any combination thereof, and two or more polymer blocks mainly containing the vinyl aromatic compound; The number of the polymer blocks mainly composed of the conjugated diene compound is one or more, and the respective polymer blocks may have the same structure or different structures.

As the vinyl aromatic compound constituting the block copolymer, for example, one or more of styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, diphenylethylene and the like can be used. It can be selected, and styrene is particularly preferred. And
The content of the vinyl aromatic compound in the hydrogenated block copolymer serving as the component (2) is 20 to 70% by weight, preferably 25 to 60% by weight, and more preferably 30 to 50% by weight.

When the amount of the vinyl aromatic compound is less than 20% by weight, the rigidity of the secondary battery case is lowered, which is not preferable. When the amount exceeds 70% by weight, the brittleness of the secondary battery case is overcome. Not preferred above. On the other hand, examples of the conjugated diene compound constituting the block copolymer include butadiene, isoprene, 1,3-pentadiene,
1 out of 2,3-dimethyl-1,3-butadiene and the like
Species or two or more are selected, but butadiene, isoprene and a combination thereof are particularly preferred.

In the polymer block mainly composed of a conjugated diene compound, the microstructure of the block can be arbitrarily selected. For example, in a polymer block mainly composed of butadiene, a 1,2-vinyl bond is formed. 2-8
5%, preferably 10-85%, more preferably 35%
~ 85%. In the polymer block mainly composed of isoprene, the total amount of 1,2-vinyl bonds and 3,4-vinyl bonds is 2 to 85%, more preferably 3 to 85%.
70%.

The molecular weight of the hydrogenated block copolymer used as the component (d) is usually such that the number average molecular weight measured in terms of polystyrene by gel permeation chromatography (GPC) is 20,000 to 1,000,000,
It is preferably from 30,000 to 300,000, more preferably from 30,000 to 200,000. The hydrogenated block copolymer used as the component (d) in the present invention may be obtained by any production method as long as it has the above characteristics.

The hydrogenated block copolymer used as the component (d) in the present invention may be, in addition to the above-mentioned hydrogenated block copolymer, a hydrogenated block copolymer and an α, β-unsaturated carboxylic acid. A known modification obtained by reacting an acid or a derivative thereof in a molten state, a solution state, or a slurry state in the presence or absence of a radical generator at a temperature of 80 to 350 ° C. The saturated carboxylic acid or its derivative may be a 0.01 to 10% by weight graft or addition) hydrogenated block copolymer, and furthermore, any of the above hydrogenated block copolymer and the modified hydrogenated block copolymer May be used as the mixture.

The preferred amount of the hydrogenated block copolymer used as the component (d) is 0.25 to 15 parts by weight, preferably 0.5 to 10 parts by weight, more preferably 1 to 10 parts by weight.
７7 parts by weight. When the amount is less than 0.25 parts by weight, the improvement of the impact resistance is not remarkable, and when the amount exceeds 15 parts by weight, the improvement of the impact resistance can be expected. Deteriorates, which is not preferable. Further, the (c) high-density polyethylene used as the component (3) that forms the dispersed phase of the present invention has a structure that satisfies the same requirements as the (c) high-density polyethylene used in the component (2) described above. . The preferred amount of the high-density polyethylene used as the component (c) is 1 to 30 parts by weight, preferably 1 to 15 parts by weight, and more preferably 1 to 7 parts by weight. If the amount is less than 1 part by weight, the improvement of the impact resistance is not remarkable, and if the amount exceeds 30 parts by weight, the improvement of the impact resistance can be expected, but the water vapor transmission resistance and the heat creep resistance as a secondary battery battery case material deteriorate. But not preferred.

Further, (e) a hydrogenated block copolymer having a crystalline melting point of 50 ° C. or more (hereinafter abbreviated as a crystalline hydrogenated block copolymer) used as the component (3) of the present invention.
Is used as a secondary battery container (including a closed secondary battery container) by suitably finely dispersing the high-density polyethylene of the component (c) in the polypropylene resin (a) forming a matrix phase. Necessary for imparting creep strength at high temperatures and impact resistance.

The structure of the crystalline hydrogenated block copolymer of the component (e) is, for example, CB, CBC, CB
—CB, (CB—) ₄ —Si, C—B—C—B—
A crystalline hydrogenated block copolymer obtained by hydrogenating a block copolymer having a structure such as C, ABC, or the like. Here, B and C mean a polymer block obtained by hydrogenating a polymer block mainly composed of a conjugated diene compound, and the blocks B and C are the respective block structures in the respective block structures before the hydrogenation reaction. The vinyl bond form at the time of polymerization of the conjugated diene compound is different,
By performing a hydrogenation reaction on the block copolymer having the block B and the block C, the block B does not have a clear melting point (differential scanning calorimetry: DSC) or has a distinct melting point.
Block C is a crystalline hydrogenated block copolymer having a trace melting point below 50 ° C and a crystalline melting point above 50 ° C (differential scanning calorimetry: DSC).

Regarding the presence or absence of crystallinity of the hydrogenated block, for example, in a polybutadiene polymer block obtained by polymerizing butadiene, the polymer block having a 1,2-vinyl bond amount of 25% or less at the time of polymerization is hydrogen. By the addition reaction, hydrogenated polybutadiene having a crystalline melting point of 50 ° C. or more is obtained, and a butadiene polymer block having a 1,2-vinyl bond amount of more than 25%, preferably more than 40% during polymerization is subjected to hydrogenation reaction. By doing so, hydrogenated polybutadiene having no clear crystal melting point can be obtained. The block A means a polymer block mainly composed of a vinyl aromatic compound. The block A is a polymer containing at least 70% by weight of the bound vinyl aromatic compound, and the above-mentioned (b) and (d) It satisfies the requirements described for the components.

Examples of the crystalline hydrogenated block copolymer usable in the present invention include (hydrogenated polybutadiene having a 1,2-vinyl bond content of 9%)-(hydrogenated 1,2-vinyl). A CB type crystalline hydrogenated block copolymer having a structure such as polybutadiene having a bonding amount of 80% is exemplified. Such a crystalline hydrogenated block copolymer means that the olefinic unsaturated bond derived from the conjugated diene compound in the block copolymer having the above structure before hydrogenation is 3%.
0% or less, preferably 20% or less, more preferably 10% or less.
% Or less by a hydrogenation reaction.

The polymer block B mainly composed of a conjugated diene compound and the polymer block C mainly composed of a conjugated diene compound refer to those in which 100% of the conjugated diene compound is polymerized in each block, or those conjugated diene compounds. It is a copolymer of a conjugated diene compound containing at least 70% by weight of the compound and another monomer copolymerizable therewith. As the conjugated diene compound constituting the block copolymer, for example, one or more kinds are selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and the like. Especially butadiene,
Isoprene and combinations thereof are preferred. Further, as other monomer components copolymerizable with these conjugated diene compounds, for example, styrene, α-methylstyrene,
One or more of vinyl toluene, p-tert-butylstyrene, diphenylethylene and the like can be selected, and styrene is particularly preferred.

The molecular weight of the crystalline hydrogenated block copolymer used as the component (e) is usually from 20,000 to 100,000 as measured by gel permeation chromatography (GPC) in terms of polystyrene.
0, preferably 30,000 to 300,000, more preferably 30,000 to 200,000. The crystalline hydrogenated block copolymer used as the component (e) used in the present invention may be obtained by any production method as long as it has the above-mentioned characteristics.

The crystalline hydrogenated block copolymer used as the component (e) in the present invention may be, in addition to the above-mentioned crystalline hydrogenated block copolymer, a crystalline hydrogenated block copolymer and α , Β-unsaturated carboxylic acid or a derivative thereof in the presence, absence or presence of a radical generator in a molten state, a solution state, or a slurry state at a temperature of 80 to 350 ° C. 0.01 to 10% by weight of the α, β-unsaturated carboxylic acid or its derivative
(Graft or addition) a crystalline hydrogenated block copolymer, or a mixture of the above-mentioned crystalline hydrogenated block copolymer and the modified crystalline hydrogenated block copolymer in any ratio. I don't care.

The preferred amount of the crystalline hydrogenated block copolymer used as the component (e) is 0.25 to 15 parts by weight, preferably 0.5 to 10 parts by weight, more preferably 1 to 7 parts by weight. Department. When the amount is less than 0.25 parts by weight, the improvement of the impact resistance is not remarkable, and when the amount exceeds 15 parts by weight, the improvement of the impact resistance can be expected. Deteriorates, which is not preferable. Further, the dispersed phase of the present invention is formed (4).
The (f) polyphenylene ether-based resin (hereinafter abbreviated as PPE) used as a component has the general formula (1)

[0043]

Embedded image

(Where R1, R2, R3 and R4 are each hydrogen, halogen, a primary or secondary lower alkyl group having 1 to 7 carbon atoms, a phenyl group, a haloalkyl group, an aminoalkyl group, A hydrogenoxy group or a halohydrocarbonoxy group in which at least two carbon atoms separate a halogen atom and an oxygen atom, which may be the same or different from each other) The reduced viscosity (0.5 g / dl, chloroform solution, measured at 30 ° C.) is preferably in the range of 0.15 to 0.70, more preferably 0.20 to 0.70.
Homopolymers and / or copolymers in the range of 60.

The PPE preferably has a polystyrene equivalent weight average molecular weight of 10,000 or more. When the weight average molecular weight is less than 10,000, productivity and color tone are lowered, which is not preferable. This weight average molecular weight can usually be known by gel permeation chromatography or the like. Specific examples of this PPE include, for example, poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), poly (2- Methyl-6-phenyl-
1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether), and the like. Further, 2,6-dimethylphenol and other phenols (for example, 2,3,6-trimethyl) Polyphenylene ether copolymers such as phenol and 2-methyl-6-butylphenol). Among them, poly (2,6-dimethyl-1,4-phenylene ether),
Copolymers of 2,6-dimethylphenol and 2,3,6-trimethylphenol are preferred, and poly (2,6-dimethylphenol) is more preferred.
6-dimethyl-1,4-phenylene ether) is preferred.

The method for producing PPE used in the present invention is not particularly limited as long as it can be obtained by a known method. For example, a method for preparing copper (P) chloride and an amine by Hay described in US Pat. The complex can be easily produced by oxidative polymerization of 2,6-dimethylphenol using the complex as a catalyst. In addition, U.S. Patent Nos. 3,306,875 and 3,257,357.
No. 3,257,358, Japanese Patent Publication No. 52
It can be easily produced by the methods described in JP-A-17880, JP-A-50-51197 and JP-A-63-152628.

The PPE used in the present invention may be a mixture of the above-mentioned PPE and a styrene monomer and / or an α, β-unsaturated carboxylic acid or a derivative thereof in the absence of a radical generator. A known modification obtained by reacting under a temperature of 80 to 350 ° C. in a molten state, a solution state, or a slurry state (the styrene-based monomer and / or the α, β-unsaturated carboxylic acid and its derivative are present in an amount of 0.1 to 1%). 01 to 10% by weight graft or addition)
PPE may be used, and a mixture of the above-mentioned PPE and the modified PPE at an arbitrary ratio may be used.

Usually, PPE is used by suitably melting and mixing it with a polystyrene resin (atactic polystyrene, high impact polystyrene, syndiotactic polystyrene, etc.). From the viewpoint of impact resistance and heat creep resistance of the obtained resin composition, no improvement effect can be expected and the resin composition is not included at all. Further, in the PPE used in the present invention, the organic solvent derived from the polymerization solvent may remain in an amount of less than 5% by weight based on 100 parts by weight of the PPE. Usually, it remains in the range of several hundred ppm to several%. Examples of the organic solvent resulting from the polymerization solvent include at least one of isomers of toluene and xylene, ethylbenzene, alcohols having 1 to 5 carbon atoms, chloroform, dichloromethane, chlorobenzene, and dichlorobenzene.

The preferred amount of PPE used as component (f) is 1 to 10 parts by weight, more preferably 1 to 10 parts by weight.
8 parts by weight. If the amount is less than 1 part by weight, the improvement of the impact resistance is not remarkable, and if it exceeds 10 parts by weight, the improvement of the impact resistance can be expected, but the water vapor transmission resistance and the heat creep resistance as the material of the secondary battery container deteriorate. But not preferred. next,
A block copolymer comprising (d) at least one polymer block A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound used in the component (4) of the present invention. A hydrogenated block copolymer obtained by hydrogenating the coalesced (hereinafter abbreviated as hydrogenated block copolymer) has the same requirements as (d) hydrogenated block copolymer used in component (2) described above. It shows a filled structure, and (f) PPE is finely dispersed suitably in a (a) polypropylene resin forming a matrix phase to form a secondary battery container (including a sealed secondary battery container). Is required to impart creep strength at high temperatures and impact resistance.

The preferred amount of the hydrogenated block copolymer used as the component (d) is 0.25 to 10 parts by weight, preferably 0.5 to 10 parts by weight, more preferably 1 to 10 parts by weight.
To 10 parts by weight. If the amount is less than 0.25 parts by weight, the improvement in impact resistance is not remarkable. If the amount exceeds 10 parts by weight, the improvement in impact resistance can be expected. Deteriorates, which is not preferable. The present invention is a resin composition containing at least one of the components (1) to (4) constituting the above-described dispersed phase with respect to 100 parts by weight of the polypropylene (a) constituting the matrix phase. When two or more components (1) to (4) are included, they can be used in combination unless the total amount of the components (1) to (4) does not exceed 50 parts by weight. If the total amount exceeds 50 parts by weight, water vapor transmission resistance and heat creep resistance deteriorate, which is not preferable.

In the present invention, in addition to the above-mentioned components, other additional components such as an antioxidant, a metal deactivator, a flame retardant (organic) may be used as needed as long as the characteristics and effects of the present invention are not impaired. Phosphate ester compounds, inorganic phosphorus compounds, aromatic halogen flame retardants, silicone flame retardants, etc.), fluoropolymers, plasticizers (oil, low molecular weight polyethylene, epoxidized soybean oil, polyethylene glycol, fatty acid esters, etc.) ), Flame retardant aids such as antimony trioxide, weather (light) improvers, slip agents, inorganic or organic fillers and reinforcements (glass fibers, glass flakes, carbon fibers, polyacrylonitrile fibers, whiskers, mica,
Talc, carbon black, titanium oxide, calcium carbonate, potassium titanate, wollastonite, conductive metal fibers, conductive carbon black, etc.), various coloring agents, release agents, and the like.

The method for producing the resin composition of the present invention comprises a single-screw extruder, a twin-screw extruder, a roll,
Examples of the method include a heat-melt kneading method using a kneader, a Brabender plastograph, a Banbury mixer, etc., and a melt-kneading method using a twin-screw extruder is most preferable. The melt-kneading temperature at this time is not particularly limited, but is usually 1
It can be arbitrarily selected from 80 to 300 ° C. The resin composition molded into the secondary battery case (including the closed type secondary battery case) of the present invention can be suitably used particularly for lead storage batteries, nickel-metal hydride battery cases, and lithium ion battery cases. The molding method is not particularly limited, but, for example, molding methods such as injection molding, hollow molding, extrusion molding, sheet molding, film molding, thermoforming, rotational molding, lamination molding can be used, and finally Is a sheet product of electrodes and electrolyte directly,
Takes a structure wrapped as a film product or injection molded product.

When the battery case is made up of two or more parts (such as connecting the main body container and the lid and two or more battery cases), these parts are joined by bonding, heat welding, vibration welding or the like. Examples of the adhesive include an epoxy resin adhesive. The epoxy resin adhesive is an adhesive made of a resin having an epoxy structure as a main skeleton, and is preferably a two-pack type made of a main agent and a curing agent.

[0054]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be specifically described below with reference to examples. In addition, the raw materials used are as follows. Component (a) polypropylene resin (a-1) Density = 0.910 g / cm ³ , melt flow rate (230 ° C., 21.2N load: hereinafter abbreviated as MFR)
= 0.4 g / 10 min, molecular weight distribution (Mw / Mn) = 9.
Polypropylene resin No. 6 (a-2) Density = 0.006 g / cm ³ , MFR = 2.
5 g / 10 min, polypropylene resin having molecular weight distribution (Mw / Mn) = 5.9 (a-3) Density = 0.910 g / cm ³ , MFR = 9.
0/10 min, polypropylene resin with molecular weight distribution (Mw / Mn) = 10.3 (a-4) Density = 0.902 g / cm ³ , MFR = 0.
5 g / 10 min, polypropylene resin with molecular weight distribution (Mw / Mn) = 6.2 (a-5) Density = 0.908 g / cm ³ , MFR = 1
6.3 g / 10 min, molecular weight distribution (Mw / Mn) = 6.1
Polypropylene resin

(B) Hydrogenated block copolymer of component (b-1) having a structure of polystyrene-hydrogenated polybutadiene-polystyrene and having an amount of bound styrene of 43
%, The amount of 1,2-vinyl bonds in the polybutadiene portion is 78
%, A hydrogenation ratio of the polybutadiene portion is 99.8%, and a number average molecular weight is 216,000. (B-2) It has a polystyrene-hydrogenated polyisoprene-polystyrene structure and has a bound styrene content of 65.
%, The amount of vinyl bonds in the polyisoprene portion is 5%, the hydrogenation rate of the polyisoprene portion is 98.9%, and the number average molecular weight is 191,000. (B-3) a polystyrene-hydrogenated polybutadiene-polystyrene structure having a bound styrene content of 35
%, The amount of 1,2-vinyl bond in the polybutadiene portion is 43%
%, A hydrogenation ratio of the polybutadiene portion is 99.8%, and a number average molecular weight is 192,000.

(B-4) Polystyrene-hydrogenated polybutadiene-polystyrene structure, having a bound styrene content of 22%, a vinyl bond content of the polybutadiene portion of 53%, and a hydrogenation rate of the polyisoprene portion of 99.2. %,
A hydrogenated block copolymer having a number average molecular weight of 110,000. (B-5) It has a structure of polystyrene-hydrogenated polyisoprene-polystyrene and has an amount of bound styrene of 65.
%, The amount of vinyl bonds in the polyisoprene portion is 5%, the degree of hydrogenation in the polyisoprene portion is 97.4%, and the number average molecular weight is 89000. (B-6) Polystyrene-hydrogenated polybutadiene-polystyrene structure having a bound styrene content of 40
%, The amount of vinyl bonds in the polybutadiene portion is 45%, the hydrogenation ratio of the polybutadiene portion is 99.1%, and the number average molecular weight is 82,000.

Polyethylene of component (c) (c-1) Density = 0.957 g / cm ³ , melt flow rate (190 ° C., 21.2 N load: hereinafter abbreviated as MFR)
= 0.16 g / 10 min high density polyethylene (c-2) Density = 0.969 g / cm ³ , MFR = 5 g
/ 10 min high density polyethylene (c-3) Density = 0.917 g / cm ³ , MFR = 0.
3g / 10min low density polyethylene

(D) Hydrogenated block copolymer of component (d-1) having a structure of polystyrene-hydrogenated polybutadiene-polystyrene and having a bound styrene content of 30
%, A polybutadiene moiety having a vinyl bond content of 45%, a polybutadiene moiety having a hydrogenation rate of 99.6%, and a number average molecular weight of 51,000. (D-2) Polystyrene-hydrogenated polybutadiene-polystyrene structure having a bound styrene content of 40
%, A polybutadiene portion having a vinyl bond content of 38%, a polybutadiene portion having a hydrogenation rate of 99.1%, and a number average molecular weight of 115,000.

(E) Crystalline hydrogenated block copolymer (e-1) Polybutadiene-1,2 having a 1,2-vinyl bond amount of 11% Polybutadiene-1,2 having a 1,2-vinyl bond amount of 73% Having a structure of polybutadiene having a vinyl bond amount of 11%, and a polybutadiene block having a 1,2-vinyl bond amount of 11% having a number average molecular weight of 12,000, 1,
A polybutadiene block copolymer having a 2-vinyl bond amount of 73% and a polybutadiene block having a number average molecular weight of 37000 and a different vinyl bond amount is synthesized, and the block copolymer is subjected to a hydrogenation reaction to have a melting point of 93 ° C. C-
A BC type crystalline hydrogenated block copolymer was obtained.

(E-2) 1,2-vinyl bond content is 20%
Having a structure of polybutadiene having a polybutadiene-1,2-vinyl bond content of 20% and a polybutadiene block having a 1,2-vinyl bond content of 20%. Molecular weight 13
A polybutadiene block copolymer having a number average molecular weight of 36,000 and a vinyl butadiene block copolymer having a number average molecular weight of 36000 and a vinyl butadiene block copolymer having a 48,000, 1,2-vinyl bond amount different from each other is synthesized. 6
A CBC type crystalline hydrogenated block copolymer at 5 ° C. was obtained.

(E-3) The amount of 1,2-vinyl bond is 30%
Having a structure of polybutadiene having a polybutadiene-1,2-vinyl bond amount of 30% and a polybutadiene block having a 1,2-vinyl bond amount of 30%. Molecular weight 11
A polybutadiene block copolymer having a number-average molecular weight of 34,000 and a polybutadiene block having a number-average molecular weight of 34,000 and a polybutadiene block copolymer having a vinyl bond content of 46% is synthesized, and the block copolymer is subjected to a hydrogenation reaction to give a melting point. 3
A crystalline hydrogenated block copolymer of CBC type at 9 ° C. was obtained.

The (f) component polyphenylene ether A polyphenylene ether having a reduced viscosity of 0.33, obtained by oxidative polymerization of 2,6-xylenol. The physical properties were evaluated as follows. (1) Water vapor permeation resistance According to JIS K7129, 40 mm 1 sheet
C., a water vapor permeability test [g /
(M ² · 24Hr)]. (2) Izod Impact Strength According to ASTM D256, a 3.2 mm thick notched test piece was measured for impact strength [J / m] at 23 ° C. (3) High temperature creep strength Creep tester (145-B manufactured by Yasuda Seiki Seisakusho Co., Ltd.)
-PC type), width 4 mm x thickness 1 mm x length 70
Using a dumbbell piece of 2 mm, the time required for the strain elongation to reach 20 mm was measured at a temperature of 80 ° C under a load equivalent to a stress of 12.25 MPa between the chucks of 40 mm.

[0063]

Examples 1 to 10 and Comparative Examples 1 to 10 A polypropylene resin and a hydrogenated block copolymer were blended in the composition shown in Table 1, and a twin-screw extruder with a vent port (ZSK) set at 210 to 280 ° C. -40; WERNER & PFLEI
The resulting mixture was melt-kneaded using DEER (Germany) to obtain pellets. 240-250 ° C using these pellets
The test piece for Izod test and the test piece for creep test were injection-molded under the condition of a mold temperature of 60 ° C. The performance of these test pieces was measured, and the results are shown in Table 1. The sheet for water vapor transmission resistance is 25
It was molded by a hot press at 0 ° C.

[0064]

Examples 11 to 20 and Comparative Examples 11 to 15 A twin screw extruder with a vent port set at 210 to 280 ° C. was prepared by blending a polypropylene resin, polyethylene and a hydrogenated block copolymer in the composition shown in Table 2. (ZSK-40; W
The mixture was melt-kneaded using ERNER & PFLEIDERER (Germany) to obtain pellets. The pellets are supplied to a screw in-line type injection molding machine set at 240 to 250 ° C., and Iz is heated at a mold temperature of 60 ° C.
A test piece for an od test and a test piece for a creep test were injection molded. The performance of these test pieces was measured, and the results are shown in Table 2. The sheet for water vapor transmission resistance was formed by a hot press at 250 ° C.

[0065]

Examples 21 to 30 and Comparative Examples 16 to 21 A polypropylene-based resin, polyethylene and a crystalline hydrogenated block copolymer were blended in the composition shown in Table 3 to obtain a mixture.
Twin screw extruder (ZSK-4)
0; WERNER & PFLEIDERER, Germany) to obtain pellets. The pellets were supplied to a screw in-line injection molding machine set at 240 to 250 ° C, and a test piece for an Izod test and a test piece for a creep test were injection-molded at a mold temperature of 60 ° C. The performance of these test pieces was measured, and the results are shown in Table 3. The sheet for water vapor transmission resistance was formed by a hot press at 250 ° C.

[0066]

Examples 31 to 39 and Comparative Examples 22 to 27 A polypropylene resin, a polyphenylene ether and a hydrogenated block copolymer were blended in the composition shown in Table 4 to obtain a mixture of 230 to 3
Twin screw extruder with vent port set at 10 ° C (ZSK
-40; WERNER & PFLEIDERER, Germany) to obtain pellets. The pellets were supplied to a screw in-line injection molding machine set at 240 to 250 ° C, and a test piece for an Izod test and a test piece for a creep test were injection-molded at a mold temperature of 60 ° C. The performance of these test pieces was measured, and the results are shown in Table 4. In addition,
The sheet for water vapor transmission resistance was formed by a hot press at 260 ° C.

[0067]

[Table 1]

[0068]

[Table 2]

[0069]

[Table 3]

[0070]

[Table 4]

[0071]

Industrial Applicability The composition of the present invention is excellent in water vapor permeability, heat creep resistance and impact resistance for use in battery cases of secondary batteries.

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Claims (2)

[Claims] (A) a propylene polymer having a density of 0.905 g / cm ³ or more and an MFR of 0.1 to 12;
The resin component forming the dispersed phase contains at least one selected from the following components (1) to (4) with respect to 100 parts by weight of the matrix phase of the polypropylene resin which is (1) to (4). A) a resin composition molded into a secondary battery case, wherein when two or more components are contained, the total amount thereof does not exceed 50 parts by weight; (1) (b) At least two polymer blocks A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound, wherein the amount of the vinyl aromatic compound is A hydrogenated block copolymer having a number average molecular weight of 100,000 or more as measured by gel permeation chromatography (GPC) in terms of polystyrene using a hydrogenated block copolymer of 20 to 70% by weight. 0.5 to 15 parts by weight. (2) (c) 1 to 30 parts by weight of high-density polyethylene having a density of 0.940 g / cm ³ or more, and (d) at least one polymer block A mainly composed of a vinyl aromatic compound and a conjugated diene compound And a hydrogenated block copolymer obtained by hydrogenating a block copolymer comprising at least one polymer block B mainly composed of ~ 15 parts by weight. (3) (c) 1 to 30 parts by weight of high-density polyethylene having a density of 0.940 g / cm ³ or more, and (e) 50 ° C
0.25 hydrogenated block copolymer having a crystalline melting point
~ 15 parts by weight. (4) (f) 1 to 10 parts by weight of polyphenylene ether, and (d) at least one polymer block A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound. 0.25 to 10 parts by weight of a hydrogenated block copolymer obtained by hydrogenating a block copolymer having an amount of the vinyl aromatic compound of 20 to 70% by weight. 2. The method according to claim 1, wherein the propylene polymer portion of the polypropylene resin (a) has a density of 0.905 g / cm ³ or more and an MFR of 0.1 to 5. Next, a resin composition to be molded into a battery case.