JP5086736B2 - Laminated porous film, battery separator and battery using the same - Google Patents

Description

  The present invention relates to a laminated porous film, and can be used as a packaging product, sanitary product, livestock product, agricultural product, building product, medical product, separation membrane, light diffusing plate, battery separator, and particularly as a nonaqueous electrolyte battery separator. It can be used suitably.

Secondary batteries are widely used as power sources for portable devices such as OA, FA, household electric appliances and communication devices. In particular, portable devices using lithium ion secondary batteries are increasing because they have a high volumetric efficiency when mounted on devices, leading to a reduction in size and weight of the devices.
On the other hand, large-sized secondary batteries are being researched and developed in many fields related to energy / environmental issues, including road leveling, UPS, and electric vehicles. Therefore, the use of lithium ion secondary batteries, which are a kind of non-aqueous electrolyte secondary battery, is expanding.

The working voltage of a lithium ion secondary battery is usually designed with an upper limit of 4.1V to 4.2V. At such a high voltage, the aqueous solution causes electrolysis and cannot be used as an electrolyte. Therefore, so-called non-aqueous electrolytes using organic solvents are used as electrolytes that can withstand high voltages.
As the solvent for the non-aqueous electrolyte, a high dielectric constant organic solvent capable of making more lithium ions exist is used, and organic carbonates such as polypropylene carbonate and ethylene carbonate are mainly used as the high dielectric constant organic solvent. It is used. As a supporting electrolyte that becomes a lithium ion source in the solvent, a highly reactive electrolyte such as lithium hexafluorophosphate is dissolved in the solvent and used.

  In the lithium ion secondary battery, a separator is interposed between the positive electrode and the negative electrode from the viewpoint of preventing an internal short circuit. Of course, the separator is required to have insulating properties due to its role. Moreover, it is necessary to have a microporous structure in order to provide air permeability as a lithium ion passage and a function of diffusing and holding the electrolyte. In order to satisfy these requirements, a porous film is used as a separator.

  In addition, separators with appropriate shutdown characteristics have recently been used. The shutdown characteristic is a function of closing the micropores of the battery separator when the temperature becomes high, and the lowest temperature among the temperatures at which the micropores are closed is called a shutdown temperature. The shutdown characteristic is an important characteristic that contributes to safety when a battery separator is incorporated in a lithium ion secondary battery. For example, when the battery becomes abnormal due to abnormalities and becomes a high temperature state, the battery separator having a shutdown characteristic closes the micropores and blocks ion conduction inside the battery, thereby preventing a subsequent temperature rise inside the battery. . In particular, with the recent increase in capacity of batteries, the need for this characteristic has further increased as the importance of battery safety has increased.

  Another characteristic that contributes to the safety of battery separators is breakdown characteristics. This breakdown characteristic is a function in which heat generation does not stop due to the appearance of the shutdown characteristic, and the film does not break even when the temperature is higher (200 ° C. or higher) and keeps the positive electrode and the negative electrode separated. If it has breakdown characteristics, insulation can be maintained even at high temperatures and a wide range of short-circuits between electrodes can be prevented, so that accidents such as ignition due to abnormal heat generation of the battery can be prevented. For this reason, when used as a battery separator, it is preferable to have this breakdown characteristic, and the breakdown temperature is preferably higher.

In response to such a demand, Japanese Patent No. 2883726 (Patent Document 1) is characterized in that a laminated film of polyethylene and polypropylene is made porous by changing the temperature in one axial direction and stretching in two stages. A separator manufacturing method has been proposed.
However, the manufacturing method requires strict control of manufacturing conditions, and it is difficult to say that productivity is good. For example, when creating a laminated film before making it porous, film formation is performed while controlling the higher order structure with a high draft ratio, but it is very difficult to form a stable film with such a high draft ratio. Have difficulty. Further, in order to develop a porous structure, it is necessary to perform multi-stage stretching in two steps, a low temperature region and a high temperature region, at a small stretching speed, the stretching speed is greatly limited, and productivity is very poor. Furthermore, the separator manufactured by the manufacturing method is very weak against tearing in the same direction as the stretching direction, and has a problem that a tear is easily generated in the stretching direction.

On the other hand, as a method for obtaining a porous film by stretching a polypropylene sheet containing a large amount of β crystals, which is one of crystal forms, in order to increase the permeability of the porous film, Japanese Patent No. 2509030 (Patent Document 2), International Publication 2002/066233 (Patent Document 3) has been proposed.
JP-A-9-255804 (Patent Document 4) discloses a resin composition comprising polypropylene, polyethylene, and a β crystal type nucleating agent, wherein the crystal phase of the polypropylene component in the resin composition is substantially β crystal. There has been proposed a method for producing a microporous membrane characterized by melt-molding into a phase-like film-like material and then stretching the film-like material at 60 to 135 ° C.

However, when any porous film is used as a separator for a secondary battery, no consideration has been given to shutdown characteristics that greatly contribute to battery safety. Therefore, these porous films are used as battery separators. However, there is a problem in securing the safety of the battery.
Furthermore, with the recent increase in energy density of batteries, polypropylene has become less resistant to heat, so breakdown characteristics are not sufficient, and there is room to improve the breakdown temperature to be higher. .

Japanese Patent No. 2883726 Japanese Patent No. 2509030 International Publication No. 2002/066233 Pamphlet Japanese Patent Laid-Open No. 9-255804

  The present invention has been made in view of the above problems, and has a porous structure with sufficient strength while maintaining strength, and a laminated porous film having excellent shutdown characteristics and breakdown characteristics. The issue is to provide.

In order to solve the above problems, the present invention is a laminated porous film in which at least two porous layers are laminated,
A β crystal nucleating agent is blended in a composition including a mixed resin of a polypropylene resin and a resin having a crystal melting peak temperature lower than that of the polypropylene resin and a crystal melting peak temperature of 100 ° C. or higher and 150 ° C. or lower , The mixing mass ratio of the polypropylene resin and the resin having a crystal melting peak temperature of 100 ° C. or more and 150 ° C. or less is polypropylene resin / resin having a crystal melting peak temperature of 100 ° C. or more and 150 ° C. or less = 20-80 / 80. A first layer of ~ 20 ;
And a second layer crystal melting peak temperature of a composition containing a resin having the polypropylene-based resin by Ri have high 175 ° C. or higher,
The shutdown temperature for closing the hole is in the range of more than 100 ° C. and 160 ° C. or less, and the breakdown temperature, which is the temperature at which the film breaks, is 200 ° C. or more,
Provided is a laminated porous film having a porosity of 35 to 65% , a pin puncture strength of 1.5 N or more, and β activity and / or β crystal generation ability .

The first layer is composed of a polypropylene resin (hereinafter referred to as “resin (A)”), a resin having a crystal melting peak temperature lower than that of the polypropylene resin and having a crystal melting peak temperature of 100 ° C. or higher and 150 ° C. or lower (hereinafter referred to as “melting peak temperature”). , Which is referred to as “resin (B)”), it is lower than the conventional polypropylene porous film and can exhibit shutdown characteristics in an appropriate temperature range when used as a battery separator.
Since the second layer is made of a composition containing a resin having a crystal melting peak temperature higher than 175 ° C. (hereinafter referred to as “resin (C)”), which is higher than that of the polypropylene-based resin, the second layer is made of a conventional polypropylene porous film. Can exhibit breakdown characteristics in a high temperature range.
Thus, in a temperature range higher than the porous film formed only with the 1st layer which exhibits a shutdown characteristic in the temperature range lower than the porous film formed only with the polypropylene resin, and the polypropylene resin. In combination with the second layer exhibiting breakdown characteristics, a laminated porous film excellent in both shutdown characteristics and breakdown characteristics can be obtained.

The “resin (B) having a crystal melting peak temperature lower than that of polypropylene resin and having a crystal melting peak temperature of 100 ° C. or higher” is a resin different from the polypropylene resin (A), and is a differential scanning calorimeter. When the temperature is raised from 25 ° C. to 240 ° C. at a heating rate of 10 ° C./min, the temperature is lower than the crystal melting peak temperature of the polypropylene resin (A) and is from 100 ° C. to 150 ° C. A resin having a crystal melting peak temperature in the range . By the previous SL crystal melting peak temperature, it is possible to exhibit the shutdown function especially suitable temperature range as a battery separator.

On the other hand, “resin (C) whose crystal melting peak temperature is higher than that of the polypropylene resin” is a resin different from the polypropylene resin (A), and from 25 ° C. to 400 ° C. using a differential scanning calorimeter. A resin having a crystal melting peak temperature in a temperature range higher than that of the polypropylene resin when heated at a heating rate of 10 ° C./min.
The crystal melting peak temperature of the crystal melting peak temperature is higher than the polypropylene resin resin (C) Ru Der 175 ° C. or higher. More preferably, it is 200 degreeC or more. By setting it as the crystal melting peak temperature, the breakdown characteristics can be exhibited at a higher temperature, which is excellent as a battery separator. Although an upper limit is not specifically limited, It is 400 degrees C or less.

Laminated porous film of the present invention, the porous layer shutdown temperature is the temperature at which hole is closed of Ri Der range of 160 ° C. or less exceed 100 ° C., before Symbol temperatures porous layer is ruptured a break-down temperature is Ru der 200 ℃ or more.
Specifically, the crystal melting peak temperature of the composition of the first layer is set lower than the crystal melting peak temperature of the composition of the second layer, and is a temperature at which the pores of the first layer close. a shutdown temperature in the range of 160 ° C. or less exceed 100 ° C., breakdown temperature the second layer is a temperature at which rupture is Ru der 200 ° C. or higher.
In the present invention, the “shutdown temperature” refers to the lowest temperature at which micropores in the laminated porous film are blocked. Specifically, when the laminated porous film is heated by the method described in the examples, Is the lowest temperature among the temperatures at which the air permeation resistance becomes 10 times or more of the air permeation resistance before heating. The “breakdown temperature” is the lowest temperature among the temperatures at which the laminated porous film breaks.

Furthermore, the laminated porous film of the present invention has β activity and / or β crystal generation power. Both β activity and β crystal-forming ability can be regarded as one index indicating that the polypropylene resin produced β crystals in the film-like material before stretching, and the polypropylene-based resin in the film-like material before stretching. If the resin is producing β crystals, fine pores are formed by subsequent stretching, so that a laminated porous film having air permeability characteristics can be obtained.
The presence or absence of the “β activity” is determined to have β activity when the crystal melting peak temperature derived from the β crystal is detected by a differential scanning calorimeter described later.
In addition, the presence or absence of the “β crystal formation force” indicates that the β crystal formation force is present when a diffraction peak derived from the β crystal is detected by measurement of the β crystal formation force using an X-ray analyzer described later. Judging.
The β activity and / or β crystal generation force is laminated in both cases where the laminated porous film of the present invention is composed of only the first layer and the second layer, and when other porous layers are laminated. It is measured in the state of a porous film.

The laminated porous film, by incorporating β-crystal nucleating agent in the composition of the first layer, it is assumed to have the β activity and / or the β crystal generation power. Furthermore, it is preferable that a β-crystal nucleating agent is blended with the polypropylene resin (A) to obtain the β activity and / or the β-crystal forming power. It is preferable that it is 0.0001-5.0 mass parts with respect to 100 mass parts of type | system | group resin (A).

In the mixed resin of the first layer, the mixing mass ratio of the polypropylene resin (A) and the resin (B) having a crystal melting peak temperature of 100 ° C. or more and 150 ° C. or less is polypropylene resin (A) / crystal melting peak temperature. There has been a 100 ° C. or higher 0.99 ° C. or less is a resin (B) = 2 0~ 8 0 /8 0~ 2 0. Before SL resin (B) is preferably a polyethylene resin.

The resin (C) having a crystal melting peak temperature of 175 ° C. or higher in the second layer is at least one selected from the group consisting of polyester resins, polystyrene resins, fluorine resins, and polymethylpentene resins. Is preferred. It is preferable that 70 mass% or more of the resin (C) is contained in the composition of the second layer.
The composition of the second layer preferably contains a filler, preferably an inorganic filler.

  The laminated porous film of the present invention preferably has an air permeation resistance measured in accordance with JIS P8117 of 1 to 10,000 seconds / 100 ml, according to Japanese Agricultural Standard No. 1019, pin diameter 1.0 mm, tip The pin puncture strength measured under the conditions of 0.5R and a pin puncture speed of 300 mm / min is preferably 1.5 N or more.

Furthermore, the present invention provides a battery separator using the laminated porous film, the battery separator is air resistance was measured according to JIS P8117 is Ru 5-3000 sec / 100ml der.
Furthermore, the present invention provides a battery incorporating the battery separator, and the battery can ensure higher safety than before.

Laminated porous film of the present invention, the composition comprising a polypropylene resin, a mixed resin of the resin the polypropylene and the crystal melting peak temperature below the crystalline melting peak temperature of the resin is 0.99 ° C. or less 100 ° C. or higher β Since it has the 1st layer in which the crystal nucleating agent was mix | blended, and the 2nd layer which consists of a composition containing resin which is 175 degreeC or more whose crystal melting peak temperature is higher than the said polypropylene resin, it was used as a battery separator. In this case, the shutdown characteristic can be exhibited in an appropriate temperature range of more than 100 ° C. and 160 ° C. or less , and the breakdown temperature is 200 ° C. or more and higher than the conventional polypropylene porous film. Breakdown characteristics can be exhibited.
In addition, the laminated porous film of the present invention has β activity and / or β crystal generation power, and is excellent in mechanical strength such as pin puncture strength and tear strength while ensuring sufficient communication. It is also excellent from the viewpoint of structure maintenance and impact resistance.
Thus, the laminated porous film of the present invention has excellent air permeability characteristics, heat resistance and strength, and can have both characteristics of shutdown characteristics and breakdown characteristics, and as a battery separator. Especially excellent.

  Furthermore, since the laminated porous film of the present invention can have the above characteristics even with a small layer structure, it is extremely excellent in productivity and economy. In addition, there is an advantage that production can be easily and efficiently performed without requiring strict control of manufacturing conditions.

Hereinafter, embodiments of the laminated porous film of the present invention will be described in detail.
In any of the embodiments, the laminated porous film of the present embodiment is configured to include at least two porous layers of the first layer and the second layer.

The first layer is made of a composition containing a mixed resin of a polypropylene resin and a resin having a crystal melting peak temperature lower than that of the polypropylene resin and a crystal melting peak temperature of 100 ° C. or more, and the second layer is made of the resin It is composed of a composition containing a resin having a higher crystal melting peak temperature than polypropylene resin, and the crystal melting peak temperature of the first layer composition is set lower than the crystal melting peak temperature of the second layer composition. Yes.
Specifically, at least one of the crystal melting peak temperature of the composition of the first layer, Ri range near the 100 ° C. to 150 DEG ° C., and still more preferably in the range of 110 ° C. to 145 ° C..
On the other hand, the crystal melting peak temperature of the composition of the second layer state, and are 175 ° C. or more, more preferably in the 200 ° C. or higher.

The laminated porous film of the present embodiment exhibits a shutdown characteristic in which pores are closed at a temperature exceeding 100 ° C. and not exceeding 160 ° C. The shutdown temperature is preferably 110 ° C to 150 ° C, more preferably 120 ° C to 145 ° C.
The laminated porous film of the present invention may have a temperature close to 100 ° C. depending on the location, for example, when a lithium ion battery incorporated as a lithium ion battery separator is left in a car in summer. In such a case, if the shutdown temperature exceeds 100 ° C., the pores in the separator are retained at 100 ° C. or lower, and the lithium ion permeation function can be maintained as the separator, which is preferable. On the other hand, if the shutdown temperature is 160 ° C. or lower, for example, when the battery becomes abnormal and exceeds 100 ° C. and reaches a high temperature of 160 ° C. or lower, the micropores of the lithium ion battery separator are immediately closed, and the lithium ion Since the permeation of ions can be blocked and the subsequent temperature rise inside the battery can be prevented, the safety is excellent.
Here, the “shutdown temperature” means the lowest temperature at which the micropores in the laminated porous film are blocked. Specifically, when the laminated porous film is heated by the method described in the examples, Is the lowest temperature among the temperatures at which the air permeation resistance becomes 10 times or more of the air permeation resistance before heating.
The shutdown temperature is adjusted by using a first layer resin (B) using a thermoplastic resin having a crystal melting peak temperature close to a desired shutdown temperature as a resin (B) having a crystal melting peak temperature lower than that of the first layer polypropylene resin. ), Or by adjusting the stretching temperature to a temperature range described later.

Furthermore, the laminated porous film of the present embodiment has a breakdown characteristic that breaks at a high temperature of 200 ° C. or higher, that is, does not break below 200 ° C. The breakdown temperature is more preferably 220 ° C. or higher, and particularly preferably 240 ° C. or higher. On the other hand, the upper limit of the breakdown temperature is not particularly limited, but is preferably 400 ° C. or less in view of the processing temperature of raw materials.
As described above, when the breakdown temperature is 200 ° C. or higher, for example, when a laminated porous film is used as a battery separator, the battery is stored or heated, and the battery separator is exposed to a high temperature. The battery separator does not break and prevents direct contact between the positive electrode and the negative electrode, so that the battery does not easily explode or burn, and is extremely excellent in safety.
Here, the “breakdown temperature” refers to the lowest temperature among the temperatures at which the laminated porous film of the present invention breaks when heated by the method described in the examples.
The breakdown temperature can be adjusted by increasing the mass ratio of the resin (C) in the composition of the second layer.

The laminated porous film of the present invention is characterized by having at least one of the β activity and the β crystal generation force.
Both β activity and β crystal forming power can be regarded as one index indicating that the polypropylene resin has generated β crystals in the film-like material before stretching. If the polypropylene-based resin in the film-like material before stretching produces β crystals, fine pores are formed by subsequent stretching, and thus a laminated porous film having air permeability characteristics can be obtained.

The presence or absence of β activity of the laminated porous film can be determined by conducting a differential thermal analysis of the laminated porous film using a differential scanning calorimeter and detecting a crystal melting peak temperature derived from β crystals of polypropylene resin. Judgment is based on no.
Specifically, the laminated porous film is heated at a heating rate of 10 ° C./min from 25 ° C. to 240 ° C. for 1 minute with a differential scanning calorimeter, and then cooled from 240 ° C. to 25 ° C. at a cooling rate of 10 ° C. / When the temperature is lowered for 1 minute and held for 1 minute, and when the temperature is raised again from 25 ° C. to 240 ° C. at a heating rate of 10 ° C./min, the crystal melting peak temperature (Tmβ) derived from the β crystal of the polypropylene resin is detected. In that case, it is determined to have β activity.

In addition, the β activity of the laminated porous film is calculated by the following formula using the heat of crystal melting derived from the α crystal of the polypropylene resin (ΔHmα) and the heat of crystal melting derived from the β crystal (ΔHmβ). Yes.
β activity (%) = [ΔHmβ / (ΔHmβ + ΔHmα)] × 100
For example, when the polypropylene resin is homopolypropylene, the amount of heat of crystal melting derived from the β crystal (ΔHmβ) detected mainly in the range of 145 ° C. or more and less than 160 ° C., and mainly detected at 160 ° C. or more and 175 ° C. or less It can be calculated from the heat of crystal melting (ΔHmα) derived from the α crystal. Further, for example, in the case of random polypropylene copolymerized with 1 to 4 mol% of ethylene, the crystal melting heat amount (ΔHmβ) derived from the β crystal detected mainly in the range of 120 ° C. or more and less than 140 ° C., and mainly 140 It can be calculated from the crystal melting calorie (ΔHmα) derived from the α crystal detected in the range of from 0 ° C. to 165 ° C.

The β activity of the laminated porous film is preferably large, and the β activity is preferably 20% or more. More preferably, it is 40% or more, and particularly preferably 60% or more. If the laminated porous film has a β activity of 20% or more, it indicates that a large amount of β crystals of polypropylene resin can be produced in the film-like material before stretching, and fine and uniform pores are formed by stretching. Many layers are formed, and as a result, a laminated porous film having high mechanical strength and excellent air permeability can be obtained.
The upper limit of β activity is not particularly limited, but the higher the β activity, the more effective the effect is obtained.

The presence or absence of the β crystal generation force is determined by a diffraction profile obtained by wide-angle X-ray measurement of a laminated porous film subjected to a specific heat treatment.
Specifically, wide-angle X-ray measurement was performed on a laminated porous film that was heat-treated at 170 ° C. to 190 ° C., which is a temperature exceeding the melting point of the polypropylene resin (A), and slowly cooled to produce and grow β crystals. When the diffraction peak derived from the (300) plane of the β-crystal of the polypropylene resin is detected in the range of 2θ = 16.0 ° to 16.5 °, it is determined that there is a β-crystal forming power.
Details regarding the β crystal structure and wide angle X-ray diffraction of polypropylene resins can be found in Macromol. Chem. 187, 643-652 (1986), Prog. Polym. Sci. Vol. 16, 361-404 (1991), Macromol. Symp. 89, 499-511 (1995), Macromol. Chem. 75, 134 (1964), and references cited therein. A detailed evaluation method of the β crystal forming power will be described in the examples described later.

As a method for obtaining the β activity and / or β crystal generation force of the laminated porous film described above, a method in which a substance that promotes the formation of α crystal of a polypropylene resin is not added, or as described in Japanese Patent No. 3739481 The method of adding the polypropylene which performed the process which generate | occur | produces a peroxide radical in this, the method of adding a (beta) crystal nucleating agent to a resin composition, etc. are mentioned.
Of these, the first layer of the composition β crystal nucleating agent to β activity and / or β crystal rather it is particularly preferred that give the product strength additives, the resin composition of the first layer in the present invention Beta crystal nucleating agent is added .
By adding a β crystal nucleating agent, it is possible to promote the generation of β crystals of polypropylene resin more uniformly and efficiently, and for a battery having a porous layer having β activity and / or β crystal generation ability A separator can be obtained.

Hereinafter, the details of the first layer and the second layer will be described.
[Explanation of the first layer]
First, the first layer will be described.
The first layer is formed from a composition comprising a mixed resin of a polypropylene resin (A) and a resin (B) having a crystal melting peak temperature lower than that of the polypropylene resin and a crystal melting peak temperature of 100 ° C. or higher. It is a porous layer.

In the first layer, the total mass of the resin (A) and the resin (B) accounts for 70% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more with respect to the total mass of the first layer. .
Weight ratio of the resin (A) and the resin (B), the resin (A) / resin (B) = 2 0 to 80/80 to 20, further have preferably 30-70 / 70-30. Especially, the one with much content of resin (A) is preferable , and it is still more preferable that it is 60-70 / 40-30. When the content of the resin (B) is 20 % by mass or more in the total mass of 100% by mass of the resin (A) and the resin (B), it is possible to exhibit the shutdown characteristics at an appropriate temperature. On the other hand, if the content of the resin (B) is 80 % by mass or less of 100% by mass of the total mass of the resin (A) and the resin (B), the first layer is easily made porous, which is preferable.

When two or more first layers are present, the mixing mass ratio of the resin (A) and the resin (B) in at least one of the first layers may be within the specified range. The mixing mass ratio of the resin (A) and the resin (B) in the other first layer is preferably resin (A) / resin (B) = 10 to 99/90 to 1, and 30 to 99 / 70-1 are more preferable, 60-99 / 40-1 are still more preferable, and 60-90 / 40-10 are especially preferable.
Since it is sufficient that at least one first layer that exhibits the shutdown characteristic exists, the shutdown characteristic is not necessarily required for the other first layers. Therefore, content of resin (B) should just be 1 mass% or more in total mass 100 mass% of resin (A) and resin (B). Of course, there is no problem even if all of the first layer develops the shutdown characteristic, but it is preferable. On the other hand, if the content of the resin (B) is 90% by mass or less of the total mass of 100% by mass of the resin (A) and the resin (B), the first layer can be easily made porous.

In the present invention, a β crystal nucleating agent is blended with the composition of the first layer to obtain β activity and / or β crystal forming power . Further, the β crystal nucleating agent is preferably blended with a polypropylene resin.

In the present invention, the blending amount of the β crystal nucleating agent to be blended with the composition of the first layer needs to be appropriately adjusted depending on the type of the β crystal nucleating agent or the composition of the polypropylene resin (A). The ratio is preferably 0.0001 to 5.0 parts by mass, more preferably 0.001 to 3.0 parts by mass, and 0.01 to 1.0 parts by mass relative to 100 parts by mass of the polypropylene resin (A). Part by mass is more preferable. If it is 0.0001 part by mass or more, β-crystals of polypropylene resin can be sufficiently produced and grown during production, and sufficient β-activity and / or β-crystal-forming power can be ensured. can get. On the other hand, addition of 5.0 parts by mass or less is preferable because it is economically advantageous and there is no β crystal nucleating agent on the film surface.
In the present invention, when there are a plurality of layers containing a polypropylene resin (A) having β activity and / or β crystal generation ability, the amount of β crystal nucleating agent added may be the same or different. . The porous structure of each layer can be appropriately adjusted by changing the addition amount of the β crystal nucleating agent.

Below, the component which comprises a 1st layer is demonstrated in detail.
<Description of polypropylene resin (A)>
Specific examples of the polypropylene resin (A) in the present invention include homopropylene (propylene homopolymer), or propylene and ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1 -Random copolymer or block copolymer with α-olefin such as octene, 1-nonene or 1-decene. Among these, homopolypropylene is more preferably used from the viewpoint of the mechanical strength of the laminated porous film.

The polypropylene resin (A) preferably has an isotactic pentad fraction (mmmm fraction) exhibiting stereoregularity of 80 to 99%. More preferably, it is 83-98%, More preferably, it is 85-97%. If the isotactic pentad fraction is too low, the mechanical strength of the film may be reduced. On the other hand, the upper limit of the isotactic pentad fraction is defined by the upper limit value that can be obtained industrially at the present time. is not.
The isotactic pentad fraction (mmmm fraction) is the same direction for all five methyl groups that are side chains with respect to the main chain of carbon-carbon bonds composed of arbitrary five consecutive propylene units. Means the three-dimensional structure located at or its proportion. Signal assignment of the methyl group region is as follows. It conforms to Zambelli et al (Macromolecules 8,687, (1975)).

  Moreover, it is preferable that Mw / Mn which is a parameter which shows molecular weight distribution of a polypropylene resin (A) is 2.0-10.0. More preferably, it is 2.0-8.0, More preferably, it is 2.0-6.0. This means that the smaller the Mw / Mn is, the narrower the molecular weight distribution is. However, when the Mw / Mn is less than 2.0, problems such as a decrease in extrusion moldability occur, and it is difficult to produce industrially. . On the other hand, when Mw / Mn exceeds 10.0, low molecular weight components increase, and the mechanical strength of the laminated porous film tends to decrease. Mw / Mn is obtained by GPC (gel permeation chromatography) method.

  Further, the melt flow rate (MFR) of the polypropylene resin (A) is not particularly limited, but usually the MFR is preferably 0.5 to 15 g / 10 minutes, and preferably 1.0 to 10 g / 10. More preferably, it is minutes. When the MFR is less than 0.5 g / 10 min, the resin has a high melt viscosity at the time of molding and the productivity is lowered. On the other hand, if it exceeds 15 g / 10 minutes, the mechanical strength of the film is insufficient, and problems are likely to occur in practice. MFR is measured according to JIS K7210 under conditions of a temperature of 230 ° C. and a load of 2.16 kg.

  The production method of the polypropylene resin (A) is not particularly limited, and a known polymerization method using a known olefin polymerization catalyst, for example, a multisite catalyst represented by a Ziegler-Natta type catalyst or a metallocene. Examples thereof include a polymerization method using a single site catalyst typified by a system catalyst.

<Description of β crystal nucleating agent>
Examples of the β crystal nucleating agent used in the present invention include those shown below, but are not particularly limited as long as they increase the formation and growth of β crystals of polypropylene resin, and two or more types are mixed. May be used.
Examples of the β crystal nucleating agent include amide compounds; tetraoxaspiro compounds; quinacridones; iron oxides having a nanoscale size; potassium 1,2-hydroxystearate, magnesium benzoate or magnesium succinate, magnesium phthalate, etc. Alkali or alkaline earth metal salts of carboxylic acids represented by: aromatic sulfonic acid compounds represented by sodium benzenesulfonate or sodium naphthalenesulfonate; di- or triesters of dibasic or tribasic carboxylic acids; phthalocyanine blue Phthalocyanine pigments typified by: a two-component compound comprising component A which is an organic dibasic acid and a component B which is an oxide, hydroxide or salt of a Group IIA metal of the periodic table; a cyclic phosphorus compound; Made of magnesium compound And the like formed product, but shows a particularly preferred among them below.

Preferred β crystal nucleating agents include those represented by general formula (I);
R _Ib —NHCO—R _Ia —CONH—R _Ic (I)
General formula (II);
R _IIb -CONH-R _IIa -CONH-R _IIc (II)
Or general formula (III);
_{R IIIb -CONH-R IIIa -NHCO-} R IIIc (III)
(In each formula, R _Ia , R _IIa and R _IIIa are the same or different and each represents a divalent hydrocarbon group having 1 to 28 carbon atoms which may be substituted;
R _Ib , R _Ic , R _IIb , R _IIc , R _IIIb and R _IIIc are the same or different and each represents an optionally substituted hydrocarbon group having 1 to 18 carbon atoms. )
An amide compound represented by

下記式（ｂ）；

下記式（ｃ）；

または、下記式（ｄ）；

で示される基を表す。化学式１〜４において、Ｒ_４およびＲ_５は同一または異なって水素原子、炭素数１〜１２の直鎖状または分岐鎖状のアルキル基、Ｒ_６およびＲ_７は同一または異なって炭素数１〜１２の直鎖状または分岐状のアルキレン基を表す。）
で示される化合物である。 Among them, as the amide compound represented by the general formula (I), (II), or (III), an amide compound represented by the following general formula (1), (2), or (3) is particularly preferable. It is mentioned as one aspect | mode of an agent.
The amide compound represented by the general formula (1) included in the general formula (I) is:
R ₂ —NHCO—R ₁ —CONH—R ₃ (1)
(In the formula, R ₁ represents a saturated or unsaturated aliphatic, alicyclic or aromatic dicarboxylic acid residue having ₁ to 28 carbon atoms;
R ₂ and R ₃ may be the same or different, and a cycloalkyl group having 3 to 18 carbon atoms, a cycloalkenyl group,
The following formula (a);

Following formula (b);

Following formula (c);

Or the following formula (d);

Represents a group represented by In Chemical Formulas 1-4, R ₄ and R ₅ are the same or different and are a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, and R ₆ and R ₇ are the same or different and have 1 to 1 carbon atoms. 12 linear or branched alkylene groups are represented. )
It is a compound shown by these.

下記式（ｆ）；

下記式（ｇ）；

または、下記式（ｈ）；

で示される基を表す。化学式５〜８において、Ｒ_１１は水素原子、炭素数１〜１２の直鎖状もしくは分岐鎖状のアルキル基、アルケニル基、シクロアルキル基またはフェニル基を表し、Ｒ_１２は炭素数１〜１２の直鎖状もしくは分岐状のアルキル基、シクロアルキル基またはフェニル基を表す。Ｒ_１３およびＲ_１４は同一または異なって、炭素数１〜４の直鎖状または分岐鎖状のアルキレン基を表す。）
で示される化合物である。
なお、Ｒ_８で示される「アミノ酸残基」におけるアミノ酸としては、天然のアミノ酸に限らず非天然のアミノ酸であってもよく、Ｄ−体またはＬ−体のいずれでもよく、α−、β−、γ−、ε−型のいずれのものでもよい。 The amide compound represented by the general formula (2) contained in the general formula (II) is:
R ₉ - CONH- R ₈ - CONH-R ₁₀ (2)
(Wherein R ₈ represents a saturated or unsaturated aliphatic, alicyclic or aromatic amino acid residue having 1 to 28 carbon atoms,
R ₉ and R ₁₀ may be the same or different, and a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group,
Following formula (e);

The following formula (f);

Following formula (g);

Or the following formula (h);

Represents a group represented by In Chemical Formulas 5 to 8, R ₁₁ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, an alkenyl group, a cycloalkyl group, or a phenyl group, and R ₁₂ has 1 to 12 carbon atoms. A linear or branched alkyl group, a cycloalkyl group or a phenyl group is represented. R ₁₃ and R ₁₄ are the same or different and each represents a linear or branched alkylene group having 1 to 4 carbon atoms. )
It is a compound shown by these.
The amino acid in the “amino acid residue” represented by R ₈ is not limited to a natural amino acid but may be a non-natural amino acid, either a D-form or an L-form, and α-, β- , Γ-, and ε-types may be used.

下記式（ｊ）；

下記式（ｋ）；

または、下記式（ｌ）；

で示される基を表す。化学式９〜１２において、Ｒ_１８は水素原子、炭素数１〜４の直鎖状もしくは分岐鎖状のアルキル基、アルケニル基を示し、Ｒ_１９は炭素数１〜１２の直鎖状もしくは分岐状のアルキル基、シクロアルキル基またはフェニル基を表し、Ｒ_２０およびＲ_２１は同一または異なって、炭素数１〜３の直鎖状若しくは分岐鎖状のアルキレン基を表す。）
で示される化合物である。 The amide compound represented by the general formula (3) contained in the general formula (III) is:
R ₁₆ - CONH- R ₁₅ - NHCO-R ₁₇ (3)
(In the formula, R ₁₅ represents an aliphatic diamine residue having 1 to 24 carbon atoms, an alicyclic diamine residue or an aromatic diamino acid residue;
R ₁₆ and R ₁₇ may be the same or different and each is a C 3-12 cycloalkenyl group, cycloalkyl group,
Following formula (i);

Following formula (j);

Following formula (k);

Or the following formula (l);

Represents a group represented by In Chemical Formulas 9 to 12, R ₁₈ represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alkenyl group, and R ₁₉ is a linear or branched group having 1 to 12 carbon atoms. Represents an alkyl group, a cycloalkyl group or a phenyl group, and R ₂₀ and R ₂₁ are the same or different and each represents a linear or branched alkylene group having 1 to 3 carbon atoms. )
It is a compound shown by these.

The amide compound represented by the general formula (1) can be prepared by amidating a dicarboxylic acid and a monoamine.
Examples of the dicarboxylic acid include malonic acid, diphenylmalonic acid, succinic acid, phenylsuccinic acid, diphenylsuccinic acid, glutaric acid, 3,3-dimethylglutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacin Acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, 1,18-octadecanedioic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-cyclohexanediacetic acid, p-phenylenediacetic acid, p-phenylenediethanoic acid, phthalic acid, 4-tert-butylphthalic acid, isophthalic acid, 5-tert-butylisophthalic acid, terephthalic acid, 1,8-naphthalic acid, 1,4-naphthalenedicarboxylic Acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diph Acid, 3,3′-biphenyldicarboxylic acid, 4,4′-biphenyldicarboxylic acid, 4,4′-binaphthyldicarboxylic acid, bis (3-carboxyphenyl) methane, bis (4-carboxyphenyl) methane, 2, 2-bis (3-carboxyphenyl) propane, 2,2-bis (4-carboxyphenyl) propane, 3,3′-sulfonyldibenzoic acid, 4,4′-sulfonyldibenzoic acid, 3,3′-oxydi Benzoic acid, 4,4′-oxydibenzoic acid, 3,3′-carbonyldibenzoic acid, 4,4′-carbonyldibenzoic acid, 3,3′-thiodibenzoic acid, 4,4′-thiodibenzoic acid, 4,4 '-(p-phenylenedioxy) dibenzoic acid, 4,4'-isophthaloyl dibenzoic acid, 4,4'-terephthaloyl dibenzoic acid, dithiosalicylic acid and the like.

  Examples of the monoamine include cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, 2-methylcyclohexylamine, 3-methylcyclohexylamine, 4-methylcyclohexylamine, 2-ethylcyclohexylamine, 4-ethylcyclohexylamine, 2-propylcyclohexylamine, 2-isopropylcyclohexylamine, 4-propylcyclohexylamine, 4-isopropylcyclohexylamine, 2-tert-butylcyclohexylamine, 4-n-butylcyclohexylamine, 4-isobutylcyclohexylamine, 4-sec- Butylcyclohexylamine, 4-tert-butylcyclohexylamine, 4-n-pentylcyclohexylamine, 4-isopepe Tilcyclohexylamine, 4-sec-pentylcyclohexylamine, 4-tert-pentylcyclohexylamine, 4-hexylcyclohexylamine, 4-heptylcyclohexylamine, 4-octylcyclohexylamine, 4-nonylcyclohexylamine, 4-decylcyclohexylamine, 4-undecylcyclohexylamine, 4-dodecylcyclohexylamine, 4-cyclohexylcyclohexylamine, 4-phenylcyclohexylamine, cycloheptylamine, cyclododecylamine, cyclohexylmethylamine, α-cyclohexylethylamine, β-cyclohexylethylamine, α-cyclohexyl Propylamine, β-cyclohexylpropylamine, γ-cyclohexylpropylamine, aniline o-toluidine, m-toluidine, p-toluidine, o-ethylaniline, p-ethylaniline, o-propylaniline, m-propylaniline, p-propylaniline, o-cumidine, m-cumidine, p-cumidine, o -Tert-butylaniline, pn-butylaniline, p-isobutylaniline, p-sec-butylaniline, p-tert-butylaniline, pn-amylaniline, p-isoamylaniline, p-sec-amylaniline P-tert-amylaniline, p-hexylaniline, p-heptylaniline, p-octylaniline, p-nonylaniline, p-decylaniline, p-undecylaniline, p-dodecylaniline, p-cyclohexylaniline, o -Aminodiphenyl, m-aminodiphenyl, p Diaminodiphenyl, p- aminostyrene, benzylamine, alpha-phenylethylamine, beta-phenylethylamine, alpha-phenylpropylamine, beta-phenylpropylamine, .gamma.-phenylpropyl amine.

The amide compound represented by the general formula (2) can be prepared by amidating an amino acid with a monocarboxylic acid and a monoamine.
Examples of the amino acid include aminoacetic acid, α-aminopropionic acid, β-aminopropionic acid, α-aminoacrylic acid, α-aminobutanoic acid, β-aminobutanoic acid, γ-aminobutanoic acid, and α-amino-α-methylbutane. Acid, γ-amino-α-methylenebutanoic acid, α-aminoisobutanoic acid, β-aminoisobutanoic acid, α-amino-n-pentanoic acid, δ-amino-n-pentanoic acid, β-aminocrotonic acid, α- Amino-β-methylpentanoic acid, α-aminoisopentanoic acid, 2-amino-4-pentenoic acid, α-amino-n-caproic acid, 6-aminocaproic acid, α-aminoisocaproic acid, 7-aminoheptanoic acid, α-amino-n-caprylic acid, 8-aminocaprylic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, 1- Minocyclohexanecarboxylic acid, 2-aminocyclohexanecarboxylic acid, 3-aminocyclohexanecarboxylic acid, 4-aminocyclohexanecarboxylic acid, p-aminomethylcyclohexanecarboxylic acid, 2-amino-2-norbornanecarboxylic acid, α-aminophenylacetic acid, α-amino-β-phenylpropionic acid, 2-amino-2-phenylpropionic acid, 3-amino-3-phenylpropionic acid, α-aminocinnamic acid, 2-amino-4-phenylbutanoic acid, 4-amino- 3-phenylbutanoic acid, anthranilic acid, m-aminobenzoic acid, p-aminobenzoic acid, 2-amino-4-methylbenzoic acid, 2-amino-6-methylbenzoic acid, 3-amino-4-methylbenzoic acid 2-amino-3-methylbenzoic acid, 2-amino-5-methylbenzoic acid, 4-amino No-2-methylbenzoic acid, 4-amino-3-methylbenzoic acid, 2-amino-3-methoxybenzoic acid, 3-amino-4-methoxybenzoic acid, 4-amino-2-methoxybenzoic acid, 4- Amino-3-methoxybenzoic acid, 2-amino-4,5-dimethoxybenzoic acid, o-aminophenylacetic acid, m-aminophenylacetic acid, p-aminophenylacetic acid, 4- (4-aminophenyl) butanoic acid, 4 -Aminomethylbenzoic acid, 4-aminomethylphenylacetic acid, o-aminocinnamic acid, m-aminocinnamic acid, p-aminocinnamic acid, p-aminohippuric acid, 2-amino-1-naphthoic acid, 3-amino- 1-naphthoic acid, 4-amino-1-naphthoic acid, 5-amino-1-naphthoic acid, 6-amino-1-naphthoic acid, 7-amino-1-naphthoic acid, 8-amino-1-naphthoic acid, 1 Amino-2-naphthoic acid, 3-amino-2-naphthoic acid, 4-amino-2-naphthoic acid, 5-amino-2-naphthoic acid, 6-amino-2-naphthoic acid, 7-amino-2-naphthoic acid Acid, 8-amino-2-naphthoic acid and the like.

  Examples of the monocarboxylic acid include cyclopropanecarboxylic acid, cyclobutanecarboxylic acid, cyclopentanecarboxylic acid, 1-methylcyclopentanecarboxylic acid, 2-methylcyclopentanecarboxylic acid, 3-methylcyclopentanecarboxylic acid, and 1-phenyl. Cyclopentanecarboxylic acid, cyclopentenecarboxylic acid, cyclohexanecarboxylic acid, 1-methylcyclohexanecarboxylic acid, 2-methylcyclohexanecarboxylic acid, 3-methylcyclohexanecarboxylic acid, 4-methylcyclohexanecarboxylic acid, 4-propylcyclohexanecarboxylic acid, 4- Butylcyclohexanecarboxylic acid, 4-pentylcyclohexanecarboxylic acid, 4-hexylcyclohexanecarboxylic acid, 4-phenylcyclohexanecarboxylic acid, 1-phenylcyclohexa Carboxylic acid, cyclohexenecarboxylic acid, 4-butylcyclohexenecarboxylic acid, cycloheptanecarboxylic acid, 1-cycloheptenecarboxylic acid, 1-methylcycloheptanecarboxylic acid, 4-methylcycloheptanecarboxylic acid, cyclohexylacetic acid, benzoic acid, o -Methyl-benzoic acid, m-methyl-benzoic acid, p-methyl-benzoic acid, p-ethyl-benzoic acid, p-propyl-benzoic acid, p-butylbenzoic acid, p-tert-butylbenzoic acid, p- Examples include pentylbenzoic acid, p-hexylbenzoic acid, o-phenylbenzoic acid, p-phenylbenzoic acid, p-cyclohexylbenzoic acid, phenylacetic acid, phenylpropionic acid, and phenylbutanoic acid.

  As said monoamine, the thing similar to the monoamine which is a raw material of the amide type compound represented by General formula (1) is mentioned.

The amide compound represented by the general formula (3) can be prepared by amidating a diamine and a monocarboxylic acid.
Examples of the diamine include 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,3-diaminopentane, 1,5-diaminopentane, 1,6-diaminohexane, , 2-diaminocyclohexane, 1,4-diaminocyclohexane, 4,4′-diaminodicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexylmethane, 1,3-bis (aminomethyl) cyclohexane, 1 , 4-bis (aminomethyl) cyclohexane, isophoronediamine, mensendiamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 1,5-diaminonaphthalene, 4,4'-diaminodiphenylmethane, 4,4 '-Diaminodiphenyl ether, 4,4'-diaminodiph Nirusurufon, and the like.
As said monocarboxylic acid, the thing similar to the monocarboxylic acid which is a raw material of the amide type compound represented by General formula (2) is mentioned.

（式中のＲ_４１およびＲ_４２は同一でも異なっても良く、水素原子または炭素数１〜１８の置換されていてもよい炭化水素基、好ましくは水素原子、アルキル基、シクロアルキル基またはアリール基を表すか、或いはＲ_４１、Ｒ_４２および窒素原子が共同して含窒素複素環基を表し、好ましくはＲ_４１およびＲ_４２はそれぞれの端で相互に結合して共同して炭素数２〜６のアルキレン基を表す。）
で示されるテトラオキサスピロ化合物が挙げられる。 As another aspect of the particularly preferred β crystal nucleating agent, the following general formula (4):

(In the formula, R ₄₁ and R ₄₂ may be the same or different, and may be a hydrogen atom or an optionally substituted hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group. R ₄₁ , R ₄₂ and a nitrogen atom jointly represent a nitrogen-containing heterocyclic group, and preferably R ₄₁ and R ₄₂ are bonded to each other at each end to jointly have 2 to 6 carbon atoms. Represents an alkylene group of
The tetraoxaspiro compound shown by these is mentioned.

  Specific examples of the tetraoxaspiro compound include 3,9-bis [4- (N-cyclohexylcarbamoyl) phenyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9- Bis {4- [N- (4-t-butylcyclohexyl) carbamoyl] phenyl} -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis {4- [N- ( 2,4-di-t-butylcyclohexyl) carbamoyl] phenyl} -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis {4- [N- (1-adamantyl) Carbamoyl] phenyl} -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis [4- (N-phenylcarbamoyl) phenyl] -2,4,8,10-tetra Oxaspiro [5.5] undecane, 3,9-bis {4- [N- (4-t-butylphenyl) carbamoyl] phenyl} -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis {4- [N- (2,4-di-t-butylphenyl) carbamoyl) phenyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9- Bis {4- [N- (1-naphthyl) carbamoyl] phenyl} -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis [4- (Nn-butylcarbamoyl) ) Phenyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis [4- (Nn-hexylcarbamoyl) phenyl] -2,4,8,10-tetra Oxaspiro [5.5] Unde 3,9-bis [4- (Nn-dodecylcarbamoyl) phenyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis [4- (N- n-octadecylcarbamoyl) phenyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis (4-carbamoylphenyl) -2,4,8,10-tetraoxaspiro [ 5.5] undecane, 3,9-bis [4- (N, N-dicyclohexylcarbamoyl) phenyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis [4 -(N, N-diphenylcarbamoyl) phenyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis [4- (Nn-butyl-N-cyclohexylcarbamoyl) Phenyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis [4- (Nn-butyl-N-phenylcarbamoyl) phenyl] -2,4,8, 10-tetraoxaspiro [5.5] undecane, 3,9-bis [4- (1-pyrrolidinylcarbonyl) phenyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 3 , 9-bis [4- (1-piperidinylcarbonyl) phenyl] -2,4,8,10-tetraoxaspiro [5.5] undecane and the like can be suitably used.

  Other particularly preferred β crystal nucleating agents include quinacridone type compounds such as quinacridone, dimethylquinacridone and dimethoxyquinacridone; for example, quinacridonequinone, 5,12-dihydro (2,3b) acridine-7-1,4- Mixed crystals of dione and quino (2,3b) acridine-6,7,13-1,4- (5H, 12H) -tetron, and quinacridonequinone type compounds such as dimethoxyquinacridonequinone: for example, dihydroquinacridone, dimethoxyhydroquinacridone and And dihydroquinacridone type compounds such as dibenzodihydroquinacridone.

（式中、ｎは１〜１２の自然数であり、
Ｒ_５１は水素原子、カルボキシル基、炭素数１〜１２の置換されていてもよい炭化水素基、好ましくは水素原子、カルボキシル基、炭素数１〜１２の直鎖状もしくは分岐鎖状のアルキル基、炭素数５〜８のシクロアルキル基または炭素数６〜１２のアリール基を表し、
Ｘは炭素数１〜１２の置換されていてもよい二価の炭化水素基、好ましくは置換されていてもよい炭素数６〜１２の二価の芳香族炭化水素基、より好ましくは炭素数１〜１２のアルキル基、炭素数５〜８のシクロアルキル基または炭素数６〜１２のアリール基で置換されていてもよい炭素数６〜１２の二価の芳香族炭化水素基を表す。）
で示されるイミド酸との塩が特に好ましい。
当該塩としては、例えば、フタロイルグリシン、ヘキサヒドロフタロイルグリシン、Ｎ−ナフタロイルアラニンまたはＮ−４−メチルフタロイルグリシンのカルシウム塩が例示できる。 Other particularly preferred β crystal nucleating agents include, for example, dicarboxylic acid salts of metals from group IIa of the periodic table, such as calcium salts of pimelic acid and calcium salt of suberic acid, and dicarboxylic acids and IIa of the periodic table Mention may be made of mixtures of metal salts from the group.
Among them, the metal from group IIa of the periodic table and the formula (5);

(In the formula, n is a natural number of 1 to 12,
R ₅₁ represents a hydrogen atom, a carboxyl group, an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, preferably a hydrogen atom, a carboxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms, A cycloalkyl group having 5 to 8 carbon atoms or an aryl group having 6 to 12 carbon atoms,
X is an optionally substituted divalent hydrocarbon group having 1 to 12 carbon atoms, preferably an optionally substituted divalent aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably 1 carbon atom. Represents a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms which may be substituted with an alkyl group having -12 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms or an aryl group having 6 to 12 carbon atoms. )
A salt with imide acid represented by is particularly preferred.
Examples of such salts include calcium salts of phthaloyl glycine, hexahydrophthaloyl glycine, N-naphthaloylalanine or N-4-methylphthaloyl glycine.

  As other aspects of the β crystal nucleating agent that is particularly preferred, the cyclic phosphorus compound represented by the general formula (6), fatty acid magnesium, aliphatic magnesium phosphate, magnesium oxide, magnesium hydroxide, magnesium carbonate, general formula (7) A composition comprising at least one magnesium compound selected from the group consisting of a magnesium salt of a cyclic phosphorus compound represented by formula (8) and a magnesium phosphinate compound represented by formula (8), or a formula (9) And a composition comprising the cyclic phosphorus compound shown and at least one magnesium compound selected from the group consisting of a magnesium phosphinate compound represented by the general formula (8), magnesium sulfate and talc.

（式中、Ａｒ_１およびＡｒ_２は同一または異なって、置換されていてもよい炭素数６〜１２の二価の芳香族炭化水素基、好ましくは置換されていてもよい炭素数１〜１８の炭化水素基で置換されていてもよいアリーレン基、より好ましくはアリーレン基、アルキルアリーレン基、シクロアルキルアリーレン基、アリールアリーレン基またはアラルキルアリーレン基を表す。）
で示される化合物である。 The cyclic phosphorus compound represented by the general formula (6) is

(In the formula, Ar ₁ and Ar ₂ are the same or different and may be substituted divalent aromatic hydrocarbon groups having 6 to 12 carbon atoms, preferably optionally substituted 1 to 18 carbon atoms. An arylene group which may be substituted with a hydrocarbon group, more preferably an arylene group, an alkylarylene group, a cycloalkylarylene group, an arylarylene group or an aralkylarylene group.
It is a compound shown by these.

（式中、Ａｒ_３およびＡｒ_４は同一または異なって、置換されていてもよい炭素数６〜１２の二価の芳香族炭化水素基、好ましくは置換されていてもよい炭素数１〜１８の炭化水素基で置換されていてもよいアリーレン基、より好ましくはアリーレン基、アルキルアリーレン基、シクロアルキルアリーレン基、アリールアリーレン基またはアラルキルアリーレン基を表す。） The magnesium salt of the cyclic phosphorus compound represented by the general formula (7) is

(In the formula, Ar ₃ and Ar ₄ are the same or different and may be substituted divalent aromatic hydrocarbon groups having 6 to 12 carbon atoms, preferably optionally substituted 1 to 18 carbon atoms. An arylene group which may be substituted with a hydrocarbon group, more preferably an arylene group, an alkylarylene group, a cycloalkylarylene group, an arylarylene group or an aralkylarylene group.

（式中、Ａｒ_５およびＡｒ_６は同一または異なって、置換されていてもよい炭素数６〜１２の二価の芳香族炭化水素基、好ましくは置換されていてもよい炭素数１〜１８の炭化水素基で置換されていてもよいアリーレン基、より好ましくはアリーレン基、アルキルアリーレン基、シクロアルキルアリーレン基、アリールアリーレン基またはアラルキルアリーレン基を表す。）
で示される化合物である。 The magnesium phosphinate compound represented by the general formula (8) is:

(In the formula, Ar ₅ and Ar ₆ are the same or different and may be substituted divalent aromatic hydrocarbon groups having 6 to 12 carbon atoms, preferably optionally substituted 1 to 18 carbon atoms. An arylene group which may be substituted with a hydrocarbon group, more preferably an arylene group, an alkylarylene group, a cycloalkylarylene group, an arylarylene group or an aralkylarylene group.
It is a compound shown by these.

（式中、Ａｒ_７およびＡｒ_８は同一または異なって、置換されていてもよい炭素数６〜１２の二価の芳香族炭化水素基、好ましくは置換されていてもよい炭素数１〜１８の炭化水素基で置換されていてもよいアリーレン基、より好ましくはアリーレン基、アルキルアリーレン基、シクロアルキルアリーレン基、アリールアリーレン基またはアラルキルアリーレン基を表す。）
で示される化合物である。 The cyclic phosphorus compound represented by the general formula (9) is

(In the formula, Ar ₇ and Ar ₈ are the same or different and may be substituted divalent aromatic hydrocarbon groups having 6 to 12 carbon atoms, preferably optionally substituted 1 to 18 carbon atoms. An arylene group which may be substituted with a hydrocarbon group, more preferably an arylene group, an alkylarylene group, a cycloalkylarylene group, an arylarylene group or an aralkylarylene group.
It is a compound shown by these.

Examples of the cyclic phosphorus compound represented by the general formula (6) include 10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1-methyl-10-hydroxy-9. , 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-methyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide 6-methyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 7-methyl-10-hydroxy-9,10-dihydro-9-oxa-10 -Phosphaphenanthrene-10-oxide, 8-methyl-10-hydroxy-9,10-dihydro-9-oxa-10- Phosphaphenanthrene-10-oxide, 6,8-dimethyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphophenanthrene-10-oxide, 2,6,8-trimethyl- 10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-ethyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenance Len-10-oxide, 6-ethyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 8-ethyl-10-hydroxy-9,10-dihydro- 9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-diethyl-10-hydroxy-9,10 Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-triethyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene-10- Oxide, 2-i-propyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-i-propyl-10-hydroxy-9,10-dihydro- 9-oxa-10-phosphaphenanthrene-10-oxide, 8-i-propyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 6, 8-di-i-propyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-o 2,6,8-tri-i-propyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-s-butyl-10-hydroxy- 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-s-butyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene- 10-oxide, 8-s-butyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 1,8-di-s-butyl-10-hydroxy- 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-tri-s-butyl-10-hydroxy-9, 0-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-t-butyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene-10- Oxide, 6-t-butyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 8-t-butyl-10-hydroxy-9,10-dihydro- 9-oxa-10-phosphaphenanthrene-10-oxide, 1,6-di-tert-butyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene-10- Oxide, 2,6-di-t-butyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxy 2,7-di-t-butyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,8-di-t-butyl-10- Hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-di-t-butyl-10-hydroxy-9,10-dihydro-9-oxa-10- Phosphaphenanthrene-10-oxide, 2,6,8-tri-t-butyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 2- t-amyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-t-amyl-10-hydroxy-9,10 -Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 8-t-amyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide 6,8-di-t-amyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-tri-t-amyl-10 -Hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-t-octyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphafe Nanthrene-10-oxide, 6-t-octyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10 Oxide, 8-t-octyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-di-t-octyl-10-hydroxy-9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-tri-t-octyl-10-hydroxy-9,10-dihydro-9-oxa-10-phospho Phenanthrene-10-oxide, 2-cyclohexyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-cyclohexyl-10-hydroxy-9,10- Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 8-cyclohexyl-10-hydroxy 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-dicyclohexyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphafenance Len-10-oxide, 2,6,8-tri-cyclohexyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-phenyl-10-hydroxy- 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-benzyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene-10- Oxide, 6-benzyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene -10-oxide, 8-benzyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-di-benzyl-10-hydroxy-9,10 -Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-tri-benzyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene -10-oxide, 2- (α-methylbenzyl) -10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6- (α-methylbenzyl) -10 -Hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 8- (α-methylbenzyl)- 0-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-di (α-methylbenzyl) -10-hydroxy-9,10-dihydro-9- Oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-tri (α-methylbenzyl) -10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene- 10-oxide, 2,6-di (α, α-dimethylbenzyl) -10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 6-t-butyl- 8-Methyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-benzyl-8-methyl-1 0-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-cyclohexyl-8-t-butyl-10-hydroxy-9,10-dihydro-9-oxa 10-phosphaphenanthrene-10-oxide, 6-benzyl-8-t-butyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 6- (Α-methylbenzyl) -8-t-butyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-t-butyl-8-cyclohexyl-10 -Hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-benzyl-8-cycl Hexyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-t-butyl-8-benzyl-10-hydroxy-9,10-dihydro-9- Oxa-10-phosphaphenanthrene-10-oxide, 6-cyclohexyl-8-benzyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphophenanthrene-10-oxide, 2, 6-di-t-butyl-8-benzyl-10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 2,6-dicyclohexyl-8-benzyl-10- Examples include hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. Yes.
These cyclic phosphorus compounds can be used alone, or two or more cyclic phosphorus compounds can be used in combination.

  Examples of the magnesium compound used in combination with the cyclic phosphorus compound represented by the general formula (6) as the β crystal nucleating agent used in the present invention include magnesium acetate, magnesium propionate, magnesium n-butyrate, magnesium i-butyrate, n- Magnesium valerate, magnesium i-valerate, magnesium n-hexanoate, magnesium n-octanoate, magnesium 2-ethylhexanoate, magnesium decanoate, magnesium laurate, magnesium myristate, magnesium myristate, magnesium palmitate, Magnesium palmitolate, magnesium stearate, magnesium oleate, magnesium linoleate, magnesium linolenate, magnesium arachidate, magnesium behenate, magnesium erucate, rig Magnesium serinate, magnesium serinate, magnesium montanate, magnesium melicinate, magnesium 12-hydroxyoctadecanoate, magnesium ricinoleate, magnesium cerebronate, magnesium (mono, dimixed) hexyl phosphate, (mono, dimixed) magnesium octyl phosphate, (Mono, dimixed) 2-ethylhexyl magnesium phosphate, (mono, dimixed) magnesium decyl phosphate, (mono, dimixed) magnesium lauryl phosphate, (mono, dimixed) magnesium myristyl phosphate, (mono, dimixed) magnesium palmitate (Mono, dimixed) magnesium stearyl phosphate, (mono, dimixed) magnesium oleyl phosphate, (mono, dimi Xdo) magnesium linoleate phosphate, (mono, dimixed) magnesium linoleyl phosphate, (mono, dimixed) magnesium docosyl phosphate, (mono, dimixed) magnesium erucyl phosphate, (mono, dimixed) magnesium tetracosyl phosphate, (mono, dimixed) Examples include magnesium hexacosyl phosphate, magnesium (mono, dimixed) octacosyl phosphate, magnesium oxide, magnesium hydroxide, and magnesium carbonate.

As the magnesium compound used in combination with the cyclic phosphorus compound represented by the above general formula (6) as the β crystal nucleating agent used in the present invention, the compound exemplified above as the cyclic phosphorus compound represented by the general formula (6) Magnesium salt, magnesium-bis (1′-hydroxy-2,2′-biphenylene phosphinate), magnesium-bis (5-methyl-1′-hydroxy-2,2′-biphenylene phosphinate), magnesium-bis (6-methyl-1′-hydroxy-2,2′-biphenylene phosphinate), magnesium-bis (1′-hydroxy-4′-methyl-2,2′-biphenylene phosphinate), magnesium-bis ( 1′-hydroxy-5′-methyl-2,2′-biphenylene phosphinate), magnesium-bis (1′-hydroxy) -6'-methyl-2,2'-biphenylene phosphinate), magnesium bis (1'-hydroxy-4 ', 6'-dimethyl-2,2'-biphenylene phosphinate), magnesium bis (5 , 4 ′, 6′-trimethyl-1′-hydroxy-2,2′-biphenylene phosphinate), magnesium-bis (5-ethyl-1′-hydroxy-2,2′-biphenylene phosphinate), magnesium -Bis (1'-hydroxy-4'-ethyl-2,2'-biphenylene phosphinate), magnesium-bis (1'-hydroxy-6'-ethyl-2,2'-biphenylene phosphinate), magnesium -Bis (1'-hydroxy-4 ', 6'-diethyl-2,2'-biphenylene phosphinate), magnesium-bis (5,4', 6'-triethyl) 1'-hydroxy-2,2'-biphenylene phosphinate), magnesium-bis (5-i-propyl-1'-hydroxy-2,2'-biphenylene phosphinate), magnesium-bis (1'-hydroxy -4′-i-propyl-2,2′-biphenylene phosphinate), magnesium bis (1′-hydroxy-6′-i-propyl-2,2′-biphenylene phosphinate), magnesium bis ( 1′-hydroxy-4 ′, 6′-di-i-propyl-2,2′-biphenylene phosphinate), magnesium-bis (5,4 ′, 6′-tri-i-propyl-1′-hydroxy -2,2'-biphenylene phosphinate), magnesium-bis (5-s-butyl-1'-hydroxy-2,2'-biphenylene phosphinate), magnesium Bis (1′-hydroxy-4′-s-butyl-2,2′-biphenylene phosphinate), magnesium-bis (1′-hydroxy-6′-s-butyl-2,2′-biphenylene phosphinate) ), Magnesium-bis (6,6′-di-s-butyl-1′-hydroxy-2,2′-biphenylene phosphinate), magnesium-bis (5,4 ′, 6′-tri-s-butyl) -1′-hydroxy-2,2′-biphenylene phosphinate), magnesium bis (5-tert-butyl-1′-hydroxy-2,2′-biphenylene phosphinate), magnesium bis (1′- Hydroxy-4′-t-butyl-2,2′-biphenylene phosphinate), magnesium-bis (1′-hydroxy-6′-t-butyl-2,2′-biphenylene phosphinate) Magnesium-bis (5,6′-di-t-butyl-1′-hydroxy-2,2′-biphenylene phosphinate), magnesium-bis (5,4′-di-t-butyl-1′-hydroxy -2,2'-biphenylene phosphinate), magnesium-bis (5,5'-di-t-butyl-1'-hydroxy-2,2'-biphenylene phosphinate), magnesium-bis (6,4 '-Di-t-butyl-1'-hydroxy-2,2'-biphenylene phosphinate), magnesium-bis (1'-hydroxy-4', 6'-di-t-butyl-2,2'- Biphenylene phosphinate), magnesium bis (5,4 ′, 6′-tri-t-butyl-1′-hydroxy-2,2′-biphenylene phosphinate), magnesium bis (5-t-amyl-) 1'-hydro Xy-2,2′-biphenylene phosphinate), magnesium bis (1′-hydroxy-4′-t-amyl-2,2′-biphenylene phosphinate), magnesium bis (1′-hydroxy-6) '-T-amyl-2,2'-biphenylene phosphinate), magnesium-bis (1'-hydroxy-4', 6'-di-t-amyl-2,2'-biphenylene phosphinate), magnesium -Bis (5,4 ', 6'-tri-t-amyl-1'-hydroxy-2,2'-biphenylene phosphinate), magnesium-bis (5-t-octyl-1'-hydroxy-2, 2'-biphenylene phosphinate), magnesium bis (1'-hydroxy-4'-t-octyl-2,2'-biphenylene phosphinate), magnesium bis (1'-hydride) Xy-6'-t-octyl-2,2'-biphenylene phosphinate), magnesium-bis (1'-hydroxy-4 ', 6'-di-t-octyl-2,2'-biphenylene phosphinate) ), Magnesium-bis (5,4 ′, 6′-tri-t-octyl-1′-hydroxy-2,2′-biphenylene phosphinate), magnesium-bis (5-cyclohexyl-1′-hydroxy-2) , 2′-biphenylene phosphinate), magnesium-bis (1′-hydroxy-4′-cyclohexyl-2,2′-biphenylene phosphinate), magnesium-bis (1′-hydroxy-6′-cyclohexyl-2). , 2'-biphenylene phosphinate), magnesium-bis (1'-hydroxy-4 ', 6'-di-cyclohexyl-2,2'-biphenylene phospho) Finate), magnesium-bis (5,4 ′, 6′-tri-cyclohexyl-1′-hydroxy-2,2′-biphenylene phosphinate), magnesium-bis (1′-hydroxy-4′-phenyl-2) , 2′-biphenylene phosphinate), magnesium-bis (5-benzyl-1′-hydroxy-2,2′-biphenylene phosphinate), magnesium-bis (1′-hydroxy-4′-benzyl-2, 2'-biphenylene phosphinate), magnesium bis (1'-hydroxy-6'-benzyl-2,2'-biphenylene phosphinate), magnesium bis (1'-hydroxy-4 ', 6'-di) -Benzyl-2,2'-biphenylene phosphinate), magnesium-bis (5,4 ', 6'-tri-benzyl-1'-hydroxy-2, '-Biphenylene phosphinate), magnesium-bis [5- (α-methylbenzyl) -1'-hydroxy-2,2'-biphenylene phosphinate], magnesium-bis [1'-hydroxy-4'-( α-methylbenzyl) -2,2′-biphenylene phosphinate], magnesium-bis [1′-hydroxy-6 ′-(α-methylbenzyl) -2,2′-biphenylene phosphinate], magnesium-bis [1′-hydroxy-4 ′, 6′-di (α-methylbenzyl) -2,2′-biphenylene phosphinate], magnesium-bis [5,4 ′, 6′-tri (α-methylbenzyl) -1′-hydroxy-2,2′-biphenylene phosphinate], magnesium-bis [5,4′-di (α, α-dimethylbenzyl) -1′-hydroxy-2,2′- Phenylene phosphinate], magnesium-bis (1′-hydroxy-4′-t-butyl-6′-methyl-2,2′-biphenylene phosphinate), magnesium-bis (1′-hydroxy-4′-) Benzyl-6′-methyl-2,2′-biphenylene phosphinate), magnesium-bis (1′-hydroxy-4′-cyclohexyl-6′-t-butyl-2,2′-biphenylene phosphinate), Magnesium-bis (1′-hydroxy-4′-benzyl-6′-t-butyl-2,2′-biphenylene phosphinate), magnesium-bis [1′-hydroxy-4 ′-(α-methylbenzyl) −6′-t-butyl-2,2′-biphenylene phosphinate], magnesium-bis (1′-hydroxy-4′-t-butyl-6′-cyclohexyl-2, '-Biphenylene phosphinate), magnesium-bis (1'-hydroxy-4'-benzyl-6'-cyclohexyl-2,2'-biphenylene phosphinate), magnesium-bis (1'-hydroxy-4'-) t-butyl-6′-benzyl-2,2′-biphenylene phosphinate), magnesium-bis (1′-hydroxy-4′-cyclohexyl-6′-benzyl-2,2′-biphenylene phosphinate), Magnesium-bis (5,4′-di-t-butyl-6′-benzyl-1′-hydroxy-2,2′-biphenylene phosphinate) and magnesium-bis (5,4′-dicyclohexyl-6′-) Benzyl-1′-hydroxy-2,2′-biphenylene phosphinate) and the like.
These magnesium compounds can be used alone or in combination of two or more magnesium compounds.

  The mass ratio of the mixture of the cyclic phosphorus compound represented by the general formula (6) and the magnesium compound is not particularly limited, but is usually 0.01 to 100 parts by mass of the magnesium compound with respect to 1 part by mass of the cyclic phosphorus compound. The ratio is preferably 0.1 to 10 parts by mass.

Examples of the cyclic phosphorus compound represented by the general formula (9) as the β crystal nucleating agent used in the present invention include 9,10-dihydro-9-oxa-10-phosphophenanthrene-10-oxide, 1- Methyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-methyl-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 6-methyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 7-methyl-9,10-dihydro-9-oxa-10-phosphenanthrene-10- Oxide, 8-methyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-dimethyl-9,10-di Dro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-trimethyl-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 2- Ethyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-ethyl-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 8-ethyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-diethyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene- 10-oxide, 2,6,8-triethyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2- i-propyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-i-propyl-9,10-dihydro-9-oxa-10-phosphenanthrene- 10-oxide, 8-i-propyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-di-i-propyl-9,10-dihydro-9- Oxa-10-phosphenanthrene-10-oxide, 2,6,8-tri-i-propyl-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 2- s-butyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-s-butyl-9,10-dihydro-9-oxa-1 -Phosphaphenanthrene-10-oxide, 8-s-butyl-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 1,8-di-s-butyl-9 , 10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-tri-s-butyl-9,10-dihydro-9-oxa-10-phosphenanthrene -10-oxide, 2-t-butyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-t-butyl-9,10-dihydro-9-oxa-10 -Phosphaphenanthrene-10-oxide, 8-t-butyl-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 1,6- -T-butyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6-di-t-butyl-9,10-dihydro-9-oxa-10-phos Phaphenanthrene-10-oxide, 2,7-di-t-butyl-9,10-dihydro-9-oxa-10-phosphophenanthrene-10-oxide, 2,8-di-t-butyl -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-di-t-butyl-9,10-dihydro-9-oxa-10-phosphenanthrene -10-oxide, 2,6,8-tri-t-butyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-t-amyl-9,10-dihydro -9-oxa-10-phosphaphenanthrene-10-oxide, 6-t-amyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 8-t-amyl -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-di-t-amyl-9,10-dihydro-9-oxa-10-phosphenanthrene -10-oxide, 2,6,8-tri-t-amyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-t-octyl-9,10-dihydro -9-oxa-10-phosphaphenanthrene-10-oxide, 6-t-octyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- X-oxide, 8-t-octyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-di-t-octyl-9,10-dihydro-9-oxa 10-phosphenanthrene-10-oxide, 2,6,8-tri-t-octyl-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 2-cyclohexyl- 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-cyclohexyl-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 8- Cyclohexyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-dicyclohexyl 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-tri-cyclohexyl-9,10-dihydro-9-oxa-10-phosphenanthrene- 10-oxide, 6-phenyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-benzyl-9,10-dihydro-9-oxa-10-phosphenance Len-10-oxide, 6-benzyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 8-benzyl-9,10-dihydro-9-oxa-10-phospho Phenanthrene-10-oxide, 6,8-di-benzyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene -10-oxide, 2,6,8-tri-benzyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2- (α-methylbenzyl) -9,10- Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6- (α-methylbenzyl) -9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 8 -(Α-Methylbenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-di (α-methylbenzyl) -9,10-dihydro-9- Oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-tri (α-methylbenzyl) -9,10-dihydro-9-oxa-10-phosphafena Nsulene-10-oxide, 2,6-di (α, α-dimethylbenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-t-butyl-8- Methyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-benzyl-8-methyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene- 10-oxide, 6-cyclohexyl-8-t-butyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-benzyl-8-t-butyl-9,10- Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6- (α-methylbenzyl) -8-t-butyl-9,10-dihydro-9-o Sa-10-phosphaphenanthrene-10-oxide, 6-t-butyl-8-cyclohexyl-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 6-benzyl- 8-cyclohexyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6-t-butyl-8-benzyl-9,10-dihydro-9-oxa-10-phospho Phenanthrene-10-oxide, 6-cyclohexyl-8-benzyl-9,10-dihydro-9-oxa-10-phosphophenanthrene-10-oxide, 2,6-di-t-butyl-8- Benzyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 2,6-dicyclohexyl And which may or may not be 8-benzyl-9,10-dihydro-9-oxa-10-phosphatonin phenanthrene-10-oxide.
These cyclic phosphorus compounds can be used alone, or two or more cyclic phosphorus compounds can be used in combination.

Examples of the magnesium compound used in combination with the cyclic phosphorus compound represented by the general formula (9) as the β crystal nucleating agent used in the present invention include the above-mentioned various magnesium phosphinate compounds, magnesium sulfate, and basic magnesium sulfate (magnesium). Examples thereof include oxysulfate) and talc. These magnesium compounds can be used alone or in combination of two or more magnesium compounds.
Although the mass ratio of the mixture of the cyclic phosphorus compound and the magnesium compound represented by the general formula (9) is not particularly limited, the magnesium compound is usually 0.01 to 100 parts by mass, preferably 0 with respect to 1 part by mass of the cyclic phosphorus compound. .1 to 10 parts by mass.

In the present specification, the “divalent hydrocarbon group” of the “optionally substituted divalent hydrocarbon group” includes a saturated linear divalent hydrocarbon group and an unsaturated linear group. Examples thereof include a divalent hydrocarbon group, a saturated cyclic divalent hydrocarbon group, and an unsaturated cyclic divalent hydrocarbon group.
Saturated linear divalent hydrocarbon groups include linear alkyl groups (eg, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl). C _1-10 alkyl group such as n-nonyl, etc.), and a group obtained by removing one terminal hydrogen atom, specifically, linear groups such as methylene, ethylene, propylene, butylene, pentylene, etc. And C _1-6 alkylene.
Examples of the unsaturated linear divalent hydrocarbon group include linear alkenyl groups (for example, vinyl, allyl, 1-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2- Pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl and other C _2-6 alkenyl groups, etc.) or a linear alkynyl group (eg ethynyl) 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, 4 - hexynyl, it includes C _2-6 1 or a group obtained by removing a hydrogen atom of the terminal alkynyl groups, etc.) and the like of 5-hexynyl and the like, in particular even Such as linear C _2-6 alkenylene or C _2-6 alkynylene and the like.

The saturated cyclic divalent hydrocarbon group may be any position such as a cycloalkyl group (eg, C _3-9 cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, etc.) A group obtained by removing one hydrogen atom (preferably a carbon atom different from a carbon atom having a bond, more preferably a carbon atom at the most distant position) (for example, C _5-7 cycloalkylene). .
Examples of the unsaturated cyclic divalent hydrocarbon group include cycloalkenyl groups (for example, 2-cyclopenten-1-yl, 3-cyclopenten-1-yl, 2-cyclohexen-1-yl, 3-cyclohexene-1- Yl, C _3-6 cycloalkenyl groups such as 1-cyclobuten-1-yl, 1-cyclopenten-1-yl, etc.), cycloalkanedienyl groups (for example, 2,4-cyclopentanedien-1-yl, 2 , 4-cyclohexanedien-1-yl, C _4-6 cycloalkanedienyl groups such as 2,5-cyclohexanedien-1-yl), aryl groups (eg, C _6-12 aryl groups such as phenyl, naphthyl, etc.) A group in which one hydrogen atom at any position (preferably a carbon atom different from a carbon atom having a bond, more preferably a carbon atom at the most distant position) is removed (example: For example, C _6-12 arylene).

  Examples of the substituent of the “optionally substituted divalent hydrocarbon group” include a hydroxyl group, a halogen atom (eg, fluorine, chlorine, bromine, iodine, etc.), a nitro group, a cyano group, and an optionally substituted group. Amino group, optionally substituted lower alkyl group, 1 to 5 halogen atoms (eg, fluorine, chlorine, bromine, iodine etc.) optionally substituted lower alkoxy group, esterified carboxyl Group, an optionally substituted carbamoyl group, and the like. These optional substituents may be substituted at 1 to 3 (preferably 1 to 2) at chemically acceptable positions.

In the present specification, examples of the hydrocarbon group of the “optionally substituted hydrocarbon group” include an aliphatic chain hydrocarbon group, an alicyclic hydrocarbon group, an aryl group, and an aralkyl group.
Examples of the “aliphatic chain hydrocarbon group” as an example of the hydrocarbon group include linear or branched aliphatic hydrocarbon groups such as an alkyl group, an alkenyl group, and an alkynyl group.
Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, 1-methylpropyl, n-hexyl, isohexyl, 1 , 1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 3,3-dimethylpropyl, 2-ethylbutyl, n-heptyl, 1-methylheptyl, 1-ethylhexyl, n-octyl, 1- _Examples thereof include C _1-10 alkyl groups (preferably C _1-6 alkyl etc.) such as methyl heptyl and nonyl.
Examples of the alkenyl group include vinyl, allyl, isopropenyl, 2-methylallyl, 1-propenyl, 2-methyl-1-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-ethyl-1-butenyl, 2 -Methyl-2-butenyl, 3-methyl-2-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 4-methyl-3-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl C _2-6 alkenyl groups such as 4-hexenyl and 5-hexenyl.
Examples of the alkynyl group include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1-hexynyl, 2- C _2-6 alkynyl groups such as hexynyl, 3-hexynyl, 4-hexynyl, 5-hexynyl and the like can be mentioned.

Examples of the “alicyclic hydrocarbon group” as an example of the hydrocarbon group include saturated or unsaturated alicyclic hydrocarbon groups such as a cycloalkyl group, a cycloalkenyl group, and a cycloalkanedienyl group.
Examples of the “cycloalkyl group” include C _3-9 cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl and the like.
Examples of the “cycloalkenyl group” include 2-cyclopenten-1-yl, 3-cyclopenten-1-yl, 2-cyclohexen-1-yl, 3-cyclohexen-1-yl, 1-cyclobuten-1-yl, 1 -C _3-6 cycloalkenyl groups such as -cyclopenten-1-yl and the like.
Examples of the “cycloalkanedienyl group” include C _4-6 such as 2,4-cyclopentanedien-1-yl, 2,4-cyclohexanedien-1-yl, 2,5-cyclohexanedien-1-yl and the like. And cycloalkanedienyl group.

Examples of the “aryl group” as an example of the hydrocarbon group include a monocyclic or condensed polycyclic aromatic hydrocarbon group, specifically, C _6- such as phenyl, naphthyl, anthryl, phenanthryl, acenaphthylenyl and the like. _{And 14} aryl group.
Examples of the “aralkyl group” as an example of the hydrocarbon group include benzyl, phenethyl, diphenylmethyl, 1-naphthylmethyl, 2-naphthylmethyl, 2,2-diphenylethyl, 3-phenylpropyl, 4-phenylbutyl, Examples thereof include C _7-19 aralkyl groups such as 5-phenylpentyl, 2-biphenylylmethyl, 3-biphenylylmethyl, 4-biphenylylmethyl, and the like.

  Examples of the substituent of the “optionally substituted hydrocarbon group” include an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, and optionally substituted. A good aryl group, an optionally substituted cycloalkyl or cycloalkenyl group, an optionally substituted heterocyclic group, an optionally substituted amino group, an optionally substituted imidoyl group, a substituted An amidino group, an optionally substituted hydroxyl group, an optionally substituted thiol group, an optionally esterified carboxyl group, an optionally substituted carbamoyl group, an optionally substituted thiocarbamoyl group Halogen atoms (eg fluorine, chlorine, bromine, iodine, etc., preferably chlorine, bromine, etc.), cyano groups, nitro groups, sulfonic acid Acyl group, and the like acyl group derived from a carboxylic acid. These optional substituents may be substituted at 1 to 3 (preferably 1 to 2) at chemically acceptable positions.

  Specific examples of these particularly preferable β crystal nucleating agents include β crystal nucleating agent “NJESTER NU-100” manufactured by Shin Nippon Rika Co., Ltd., and specific examples of polypropylene resins to which β crystal nucleating agents are added include polypropylene manufactured by Aristech. “Bepol B-022SP”, polypropylene manufactured by Borealis “Beta (β) -PP BE60-7032”, polypropylene manufactured by mayzo “BNX BETAPP-LN”, and the like.

<Description of Resin (B) having a Crystal Melting Peak Temperature Lower than that of Polypropylene Resin and a Crystal Melting Peak Temperature of 100 ° C. or More and 150 ° C. or Less >
By forming the first layer with a composition comprising a mixed resin obtained by mixing the resin (B) with the polypropylene resin (A), an appropriate shutdown characteristic is expressed in the laminated porous film.
The thermal characteristics of the resin (B) contained in the first layer are important. That is, it is necessary to select the resin (B) so that the crystal melting peak temperature of the composition constituting the first layer is lower than the crystal melting peak temperature of the polypropylene resin (A) and exceeds 100 ° C. . Therefore, the resin (B) has a crystal melting peak temperature is lower than the polypropylene resin (A) used in the composition of the first layer, and, upon the product layer porous film, as described above In order to express such preferable shutdown characteristics, the crystal melting peak temperature of the resin (B) is set to 100 ° C. or more and 150 ° C. or less.

  Here, the crystal melting peak temperature of the resin (B) is the crystal melting peak temperature detected when the temperature is raised from 25 ° C. to 240 ° C. at a heating rate of 10 ° C./min using a differential scanning calorimeter. Point to.

Types of polypropylene resins than the crystalline melting peak temperature is low and the crystal melting peak temperature of 100 ° C. or higher 0.99 ° C. or less der Ru resin (B) is particularly limited as long as it satisfies the requirement of the crystal melting peak temperature It is not a thing.
Specifically, for example, as resin (B) having a crystal melting peak temperature of 100 ° C. or higher and 150 ° C. or lower, low density polyethylene, high density polyethylene, linear low density polyethylene, ethylene vinyl acetate copolymer, polypropylene or poly Thermoplastic resins such as polyolefin resins such as methylpentene, polystyrene resins, polyacrylic resins, polyvinyl chloride, polyester resins, polyether resins, polyamide resins and the like can be mentioned.
Moreover, you may use the mixture of two or more types of thermoplastic resins as resin (B) as needed.
In addition, as long as the said thermal characteristic is satisfy | filled, the other polypropylene resin different from the said polypropylene resin (A) can also be used.

  Among them, as a resin (B) having a crystal melting peak temperature of 100 ° C. or higher and 150 ° C. or lower from the viewpoint of its chemical resistance and the like, a polyolefin resin, a mixture of polyolefin resins, or a polyolefin resin and other thermoplastic resins It is preferable to use a mixture. In particular, a polyethylene resin such as low density polyethylene, high density polyethylene or linear low density polyethylene, or a mixture of a polyethylene resin and another polyolefin resin is more preferable, and a polyethylene resin alone is more preferable. In particular, chemical resistance is important when considering use as a battery separator.

Density of the polyethylene resin is preferably 0.920~0.970g / cm ^3, more preferably 0.930~0.970g / cm ^3, 0.940~0.970g / cm ³ is more preferable. A density of 0.920 g / cm ³ or more is preferable because a first layer having an appropriate shutdown temperature can be formed. On the other hand, if it is 0.970 g / cm ³ or less, it is preferable in that a laminated porous film having a first layer having an appropriate shutdown temperature can be formed and that stretchability is maintained. The density can be measured according to JIS K7112 using a density gradient tube method.

Further, the melt flow rate (MFR) of the polyethylene resin is not particularly limited, but usually the MFR is preferably 0.5 to 15 g / 10 minutes, and 1.0 to 10 g / 10 minutes. It is more preferable. An MFR of 0.5 g / 10 min or more is preferable because the melt viscosity of the resin at the time of molding is sufficiently low, so that the productivity is excellent. On the other hand, if it is 15 g / 10 minutes or less, since it is close to the melt viscosity of the polypropylene resin to be mixed, dispersibility is improved, resulting in a homogeneous laminated porous film, which is preferable.
MFR is measured in accordance with JIS K7210 under conditions of a temperature of 190 ° C. and a load of 2.16 kg.

  In addition, the manufacturing method of resin (B) whose crystal melting peak temperature represented by polyethylene resin is 100 degreeC or more and 150 degrees C or less is not specifically limited, Well-known polymerization using a well-known olefin polymerization catalyst Examples of the method include a polymerization method using a multisite catalyst typified by a Ziegler-Natta type catalyst and a single site catalyst typified by a metallocene catalyst.

[Explanation of the second layer]
Next, the second layer will be described.
As described above, the second layer is a porous layer imparting breakdown characteristics to the laminated porous film of the present invention, and is formed from a composition containing a resin having a crystal melting peak temperature higher than that of the polypropylene resin. doing.

If the second layer is composed of a composition having a large number of fine pores communicating in the thickness direction and having a crystal melting peak temperature of 175 ° C. or higher that is higher than the composition of the first layer as described above. Any structure may be used. For example, it may have a structure in which fine pores are provided in a film-like material made of a thermoplastic resin composition, or a particulate or fibrous fine material aggregates to form a layer, and a gap between the fine materials. May be a structure in which the micropores are formed. The second layer of the present invention preferably has the former structure in which uniform fine pores can be formed and the porosity and the like can be easily controlled.

Below, the component which comprises a 2nd layer is demonstrated in detail.
<Description of Resin (C) with Higher Crystal Melting Peak Temperature than Polypropylene Resin (A)>
The thermal characteristics of the resin (C) contained in the second layer are important. That is, it is necessary to crystal melting peak temperature of the composition constituting the second layer to select the resin (C) so that the high have 175 ° C. or higher than the crystal melting peak temperature of the polypropylene resin (A). Upon the product layer porous film, for expressing the preferred breakdown characteristics as described above, the crystal melting peak temperature of the resin (C) is set to 175 ° C. or higher, good Mashiku is 180 ° C. or higher, more preferably 200 It is preferable to have a crystal melting peak temperature of at least ° C. The upper limit of the crystal melting peak temperature of the resin (C) is preferably 400 ° C.
The crystal melting peak temperature of the resin (C) is a peak value of the crystal melting temperature collected at a heating rate of 10 ° C./min using a differential scanning calorimeter in accordance with JIS K7121.

Specific examples of the resin (C) having a crystal melting peak temperature higher than that of the polypropylene resin include polyolefin resins such as polymethylpentene and ethylene-propylene-diene; polyester resins such as polyethylene terephthalate, polybutylene terephthalate and polyarylate. Polyether resin such as resin, polyacetal, polyphenylene ether, polyether ether ketone, polysulfone, polyether sulfone or polyphenylene sulfide; polyamide resin such as 6 nylon, 6-6 nylon or 6-12 nylon; polystyrene resin; Examples thereof include methacrylic resins; polyvinyl chloride resins; fluorine-based resins; polycarbonate-based resins; and heat-resistant thermoplastic resins such as aramid resins.
Among these, polyester resins, polystyrene resins, fluorine resins, polymethylpentene, and the like can be preferably used. In particular, when considering use as a battery separator, an olefin resin such as polymethylpentene or a fluorine resin is preferable as the resin (C) from the viewpoint of chemical resistance.

Examples of the polyester resin include a copolymer of a dicarboxylic acid and a dialcohol component. More specifically, in addition to the above-mentioned polyethylene terephthalate, polybutylene terephthalate, polyarylate, polytrimethylene terephthalate or polyethylene naphthalate, etc. are mentioned, but from the viewpoint of improving the heat resistance of the laminated porous film of the present invention. Polybutylene terephthalate having a high crystallinity and a high crystallization rate is more preferably used.
The polyester resin can be produced by a known method, or a commercially available product may be used. For example, as the polybutylene terephthalate, a trade name “Duranex” (manufactured by Polyplastics Co., Ltd.) and a trade name “Novaduran” (manufactured by Mitsubishi Engineering Plastics Co., Ltd.) are available as commercial products.

Examples of the polystyrene resins include styrene homopolymers and copolymers with monomers copolymerizable with styrene. More specifically, atactic polystyrene, syndiotactic polystyrene, styrene-conjugated diene copolymers, hydrogenated derivatives thereof, and the like can be given. Examples of the styrene-conjugated diene copolymer include acrylonitrile-styrene resin (AS resin) or acrylonitrile-butadiene-styrene resin (ABS resin).
Among these, syndiotactic polystyrene with high crystallinity is more preferably used from the viewpoint of improving the heat resistance of the laminated porous film of the present invention.
The polystyrene resin can be produced by a known method, or a commercially available product may be used. For example, as syndiotactic polystyrene, the trade name “Zarek” (manufactured by Idemitsu Kosan Co., Ltd.) is available as a commercial product.

Examples of the fluororesin include polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer, and polyvinylidene fluoride. It is done. Among these, polyvinylidene fluoride is preferably used from the viewpoint of moldability.
The fluororesin can be produced by a known method, or a commercially available product may be used. For example, the trade name “Fluon” (manufactured by Asahi Glass Co., Ltd.) is available as an ethylene-tetrafluoroethylene copolymer, and “Polyfluorone” (manufactured by Daikin Co., Ltd.) is commercially available as polytetrafluoroethylene.

Moreover, you may use the mixture of 2 or more types of resin in a 2nd layer as needed. In this case, it is preferable to mix two or more of the aforementioned resins (C) or a mixture of the resin (C) and another thermoplastic resin as long as the heat resistance characteristics of the laminated porous film, specifically, the BD characteristics are not impaired. In particular, a mixture of two or more of the resins (C) is preferable.
However, in the second layer, the mass of the resin (C) (the total mass when plural kinds of resins (C) are used) occupies 70% by mass or more with respect to the total mass of the resin component of the second layer. Is preferred. More preferably, it is 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 100%.

  Other thermoplastic resins that can be mixed with the resin (C) include thermoplastic resins such as polyolefin resins such as low density polyethylene, high density polyethylene, linear low density polyethylene, and ethylene vinyl acetate copolymer. It is done. Among these, when considering use as a battery separator, it is preferable to use a polyolefin-based resin as another thermoplastic resin from the viewpoint of chemical resistance and the like.

  The composition of the second layer may contain a substance that promotes porosity. In particular, a filler is preferably added to the composition of the second layer. By inserting a filler, a porous structure can be obtained more efficiently and the shape of the pores can be easily controlled.

<Description of filler blended in composition of second layer>
As the filler, any inorganic or organic filler can be used, and one or a combination of two or more can be used. Especially, it is preferable to use an inorganic filler from the viewpoint of heat resistance and the like.

  Examples of inorganic fillers include carbonates such as calcium carbonate, magnesium carbonate and barium carbonate; sulfates such as calcium sulfate, magnesium sulfate and barium sulfate; chlorides such as sodium chloride, calcium chloride and magnesium chloride; aluminum oxide, oxidation In addition to oxides such as calcium, magnesium oxide, zinc oxide, titanium oxide, and silica, silicates such as talc, clay, and mica can be used. Among these, barium sulfate is preferable from the viewpoint of chemical resistance.

  As the organic filler, resin particles having a crystal melting peak temperature higher than the stretching temperature are preferable so that the filler does not melt at the stretching temperature, and crosslinked resin particles having a gel fraction of about 4 to 10% are more preferable. Examples of organic fillers include ultra high molecular weight polyethylene, polystyrene, polymethyl methacrylate, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polysulfone, polyethersulfone, polyetheretherketone, polytetrafluoroethylene, polyimide, polyether. Examples thereof include thermoplastic resins such as imide, melamine, and benzoguanamine, and thermosetting resins. Among these, cross-linked polystyrene and the like are particularly preferable.

  As an average particle diameter of the said filler, it is 0.1-50 micrometers, for example, Preferably it is 0.3-10 micrometers, More preferably, it is 0.5-5 micrometers. When the average particle size is less than 0.1 μm, the dispersibility decreases due to aggregation of fillers, and it becomes difficult to uniformly disperse in the thermoplastic resin composition. Also, when the fine pores are formed by peeling the interface between the filler and the thermoplastic resin by stretching, the dispersibility of the filler decreases when the average particle size of the filler is less than 0.1 μm, When interfacial peeling is performed, the starting point of the porosity is insufficient, and it is difficult to efficiently obtain a laminated porous film. On the other hand, when the average particle diameter exceeds 50 μm, it is difficult to make the film thin, and the mechanical strength of the film is remarkably lowered.

  The blending amount of the filler is, for example, 50 with respect to 100 parts by mass of the total thermoplastic resin contained in the second layer when the interface between the filler and the thermoplastic resin containing the resin (C) is peeled to form micropores. -400 mass parts, More preferably, it is 50-300 mass parts. When the amount of the filler is less than 50 parts by mass, the effect of blending such a filler that the desired good porous structure is hardly expressed cannot be obtained sufficiently. On the other hand, if the amount of filler exceeds 400 parts by mass, not only will it be liable to cause problems in the process such as resin burning during molding, but molding stability will be reduced.

A plasticizer may be added to the composition constituting the second layer. In particular, when a filler is blended in the composition, it is preferable to add a plasticizer for the purpose of improving the dispersibility of the filler.
Examples of the plasticizer include ester compounds, amide compounds, alcohol compounds, amine compounds, epoxy compounds, ether compounds, mineral oils, waxes, liquid silicones, fluorine oils, liquid polyethers, liquid polybutenes, liquid polybutadienes, and carboxylates. , Carboxylic acid compounds, sulfonates, sulfone compounds, amine salts, fluorine compounds, and the like.

  Specifically, plastic compounding agents [published by Taiseisha Co., Ltd., November 30, 1987, second edition issued] P31-P64, P83, P97-P100, P154-P158, P178-P182, P271-P275, P283-294 And the like. Further, the surfactant compounds listed in the new surfactant introduction [published by Sanyo Kasei Kogyo Co., Ltd., August 1992, third edition] can also be suitably used as the plasticizer.

More specifically,
Examples of the ester compound include tetraglycerin tristearate, glycerin tristearate, stearyl stearate, ethylene carbonate, distearyl carbonate, dioctyl naphthalate, and the like.
Examples of the amide compound include ethylene bis stearamide and hexamethylene bis stearamide.
Examples of the alcohol compound include stearyl alcohol, oleyl alcohol, dodecylphenol and the like.

Examples of the amine compound include dihydroxyethyl stearylamine and laurylamine.
Examples of amine salt compounds include stearyl dimethyl betaine and lauryl trimethyl ammonium chloride.
Examples of the epoxy compound include epoxy soybean oil.
Examples of the ether compound include triethylene glycol.
Mineral oil includes kerosene and naphthenic oil.
Examples of the wax include paraffin wax.
Examples of the carboxylate include calcium stearate and sodium oleate.
Examples of carboxylic acid compounds include stearic acid and caproic acid.
Examples of the sulfonate include sodium dodecylbenzenesulfonate.
Examples of the sulfone compound include sulfolane and dipropyl sulfone.

In view of the use of the laminated porous film of the present invention, the plasticizer is preferably a plasticizer having a melting point of 25 ° C. or higher and a boiling point of 140 ° C. or higher.
Here, the melting point of 25 ° C. or higher is defined as one having a crystal melting peak temperature of 25 ° C. or higher by differential scanning calorimetry, or a kinematic viscosity at 25 ° C. of 100,000 mm ² / sec or higher.
The boiling point of 140 ° C. or higher means that the boiling point is clearly 140 ° C. or higher, or the mass after heating at 140 ° C. for 1 hour does not decrease by 10% or more with respect to the mass before heating.

  The blending amount of the plasticizer is 0.1 to 30 parts by weight, preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the total thermoplastic resin contained in the second layer. Part. When the blending amount of the plasticizer is less than 0.1 parts by mass, the effect of blending the plasticizer such that the desired good stretchability is hardly expressed and the non-uniform porous structure is likely to be sufficiently obtained. I can't get it. Moreover, when the compounding quantity of a plasticizer exceeds 30 mass parts, it will become easy to raise | generate the malfunction on processes, such as resin baking and eye-gearing, when shape | molding a film-form thing.

[Description of other components of first layer and second layer]
In the composition for forming the first layer and the second layer, in addition to the components described above, additives generally blended in the resin composition can be added as appropriate within a range that does not significantly impair the effects of the present invention. Examples of the additive include recycling resin, silica, talc, kaolin, carbonic acid, etc., which are added for the purpose of improving / adjusting the processability, productivity, and various physical properties of the laminated porous film. Inorganic particles such as calcium, pigments such as titanium oxide and carbon black, flame retardants, weathering stabilizers, heat stabilizers, antistatic agents, melt viscosity improvers, crosslinking agents, lubricants, nucleating agents, plasticizers, anti-aging agents And additives such as antioxidants, light stabilizers, ultraviolet absorbers, neutralizers, antifogging agents, antiblocking agents, slip agents, and coloring agents. Specifically, the interfaces as antioxidants described in P154 to P158 of PLASTICS compounding agents, UV absorbers described in P178 to P182, and antistatic agents described in P271 to P275 Activators, lubricants described in P283-294, and the like.

  Further, if necessary, the first layer and the second layer do not impair the thermal characteristics of the laminated porous film, specifically the SD characteristics and the BD characteristics, which are called rubber components such as thermoplastic elastomers. You may add in the range. Examples of the thermoplastic elastomer include styrene / butadiene, polyolefin, urethane, polyester, polyamide, 1,2-polybutadiene, polyvinyl chloride, and ionomer.

[Description of Laminated Structure of Laminated Porous Film]
Next, the laminated structure of the laminated porous film of the present invention will be described.
If the laminated porous film of the present invention is provided with two layers of the first layer and the second layer which are the basic structure, it has excellent air permeability characteristics and mechanical strength, but also has shutdown characteristics and breakdown characteristics. Can also be used. Therefore, as long as the function of the laminated porous film is not hindered, the first layer and the second layer may each have two or more layers.
The simplest structure is a two-layer structure of a first layer and a second layer, and the next simple structure is a two-kind three-layer structure of both outer layers and an intermediate layer, which are preferable structures. In the case of two types and three layers, the first layer / second layer / first layer or the second layer / first layer / second layer may be used. Moreover, it can also be set as the laminated structure of 2 types 5 layers like 2nd layer / 1st layer / 2nd layer / 1st layer / 2nd layer. The number of layers may be 4 layers, 5 layers, 6 layers, and 7 layers, as necessary.
Above all, the second layer / first layer / second layer three-layer structure has excellent air permeability characteristics and mechanical strength, and has a high performance laminated porous film having shutdown characteristics and breakdown characteristics. Is particularly excellent because it can be produced more efficiently and economically.

Regarding the stacking ratio between the first layer and the second layer, the value of the first layer (the total thickness when there are two or more layers) / the second layer (the total thickness when there are two or more layers) is 0. It is 1-10, Preferably it is 0.3-5, More preferably, it is 0.5-3. When it is smaller than 0.1, the shutdown layer is not sufficiently exhibited since it is substantially the same as the first layer, and it is difficult to ensure the safety of the battery when applied to the battery, for example. On the other hand, when it is larger than 10, the breakdown characteristics are not sufficiently exhibited as in the case where the second layer is substantially absent, and it is difficult to ensure the safety of the battery when applied to the battery, for example.
Even in the case of the second layer / first layer / second layer type 3 layer, the value of the layer ratio of the first layer to the second layer is 0.1 to 10, preferably 0.3 to 5. Yes, more preferably 0.5 to 3, for the same reason as described above.

In addition, it is possible to adopt a form of three types and three layers in combination with layers having other functions as required. Other layers may be laminated or may be appropriately treated, and is not particularly limited to a laminated structure including only the first layer and the second layer.
When other layers other than the first layer and the second layer exist, the other layers need to be provided so that the relationship between the first layer and the second layer does not deviate from the relationship described above. It is preferable that the total thickness of the other layers is 0.1 to 0.5, preferably 0.1 to 0.3, with respect to the total thickness 1.

[Description of shape and physical properties of laminated porous film]
The form of the laminated porous film to be obtained may be either a flat shape or a tube shape, but it is possible to take several products as products in the width direction, so that the productivity is good, and the inner surface is treated with a coat or the like. The planar shape is more preferable from the viewpoint of being able to perform the above.
The thickness of the laminated porous film of the present invention is 1 to 500 μm, preferably 5 to 300 μm, and more preferably 7 to 100 μm. When using as a battery separator especially, 1-50 micrometers is preferable and 10-30 micrometers is more preferable. When used as a battery separator, if the thickness is 1 μm or more, preferably 10 μm or more, substantially necessary electrical insulation can be obtained. For example, even when a large voltage is applied, it is difficult to short-circuit and is safe. Excellent. Further, if the thickness is 50 μm or less, preferably 30 μm or less, the electric resistance of the laminated porous film can be reduced, so that the battery performance can be sufficiently ensured.

  The physical properties of the laminated porous film of the present invention can be freely adjusted by the composition of the first layer or the second layer, the number of laminated layers and the lamination ratio, combinations with layers having other properties, and the production method.

The air permeability resistance of the laminated porous film of the present invention is preferably 1 to 10000 seconds / 100 ml, more preferably 5 to 3000 seconds / 100 ml, and particularly preferably 10 to 2000 seconds / 100 ml.
If the air resistance is greater than 10,000 seconds / 100 ml, the numerical value of the air resistance will be obtained in the measurement, but it means that the structure is quite poor in communication, so there may be substantially no communication. Many. On the other hand, if it is less than 1 second / 100 ml, the porous structure becomes rough and the pore diameter becomes too large, which is not preferable.
The air permeation resistance represents the difficulty of air passage in the film thickness direction, and is specifically expressed in the number of seconds required for 100 ml of air to pass through the film. Therefore, it means that the smaller the numerical value is, the easier it is to pass through, and the higher numerical value is, the more difficult it is to pass. That is, a smaller value means better communication in the thickness direction of the film, and a larger value means poor communication in the thickness direction of the film. Communication is the degree of connection of holes in the film thickness direction. If the air permeability resistance of the laminated porous film of the present invention is low, it can be used for various applications. For example, when used as a separator of a lithium ion secondary battery, a low air permeability resistance means that lithium ions can be easily transferred, which is preferable because the battery performance is excellent.
The air resistance is measured by the method described in the examples.

In the laminated porous film of the present invention, the porosity is 35 to 65 %. The porosity is an important factor for defining the porous structure. If the porosity is less than 35 %, it is difficult to substantially obtain communication. On the other hand, if the porosity is larger than 65 %, it becomes difficult to handle from the viewpoint that the mechanical strength of the film becomes weak.
The porosity is measured by the method described in the examples.

In the laminated porous film of the present invention, the pin penetration strength is 1 . 5N or more, more preferably 2.0N or more, and further preferably 3.0N or more.
The pin puncture strength is a value of breaking strength when a needle is pierced into the surface of the film, and serves as an index of the mechanical strength of the film. In particular, when the laminated porous film of the present invention is used as a battery separator, it greatly contributes to short-circuiting and productivity during battery production. If the pin puncture strength is lower than 1.5N, the probability of occurrence of a short circuit due to film breakage due to foreign matter or the like during battery production is increased, which is not preferable.
On the other hand, the upper limit value of the pin puncture strength is not particularly specified, but usually 10N or less is used.
The pin puncture strength is measured by the method described in the examples.

Moreover, in the laminated porous film of this invention, it is preferable that the anisotropy is small from a viewpoint of film physical property. As an anisotropy index, it can be expressed by a ratio of tensile strength in the MD direction (take-off (flow) direction) and TD direction (perpendicular to MD) or a ratio of tear strength in the MD direction and TD direction.
For example, taking tensile strength as an example, the lower limit value of the “MD strength / TD strength ratio” is 0.05 or more, preferably 0.1 or more, more preferably 0.3 or more as a ratio of the ratio. . If the “MD strength / TD strength ratio” is 0.05 or more, the physical properties are balanced, and in addition to handling, the porous structure finally has a smaller anisotropy film. Further, the upper limit value of the “MD strength / TD strength ratio” is 20 or less, preferably 10 or less, more preferably 7 or less. If the “MD strength / TD strength ratio” is 20 or less, the physical properties are balanced, and in addition to handling, the porous structure finally has a smaller anisotropy film.

The measuring method of the tensile strength is measured according to JIS K7127. Specifically, the width of both MD and TD is 15 mm, the distance between chucks is 40 mm, and the crosshead speed is 200 mm / min.
The MD tensile strength is 50 MPa or more, preferably 100 MPa or more, more preferably 120 MPa or more. If it is 50 MPa or more, it is sufficient strength when handling the film. Although there is no particular upper limit, a range in which the balance with TD tensile strength does not deviate from the above range is preferable.
The TD tensile strength is 50 MPa or more, preferably 100 MPa or more, more preferably 120 MPa or more. If it is 50 MPa or more, it is sufficient strength when handling the film. Although there is no particular upper limit, a range in which the balance with the MD tensile strength does not deviate from the above range is preferable.

[Description of manufacturing method]
Next, although the manufacturing method of the laminated porous film of this invention is demonstrated, this invention is not limited only to the laminated porous film manufactured by this manufacturing method.
The manufacturing method of the laminated porous film of this invention is divided roughly into the following two by the order of porous formation and lamination.
(A) a porous film SD comprising a polypropylene resin (A) and a composition containing a thermoplastic resin (B) having a crystal melting peak temperature lower than that of the polypropylene resin and a crystal melting peak temperature of 100 ° C. or higher; A porous film HR made of a composition containing a resin (C) having a crystal melting peak temperature higher than that of the polypropylene resin (A) is prepared, and then at least the porous film SD and the porous film HR are laminated, and the first layer And a method for forming a laminated porous film having a second layer.
(B) a polypropylene resin (A), a layer containing a thermoplastic resin (B) having a crystal melting peak temperature lower than that of the polypropylene resin and a crystal melting peak temperature of 100 ° C. or higher, and the polypropylene resin (A) A method of producing a laminated nonporous film-like material comprising at least two layers of a composition comprising a resin (C) having a higher crystal melting peak temperature, and then making the nonporous film-like material porous.

Examples of the former method include a method of laminating the porous film SD and the porous film HR, and a method of laminating with an adhesive or the like.
The latter method includes a non-porous film comprising a polypropylene resin (A) and a composition containing a thermoplastic resin (B) having a crystal melting peak temperature lower than that of the polypropylene resin and a crystal melting peak temperature of 100 ° C. or higher. A non-porous film-like material HR made of a composition comprising a resin SD and a resin (C) having a higher crystal melting peak temperature than the polypropylene resin (A). There is a method of making a porous material after laminating the product HR, or a method of making the laminated nonporous film-like material directly by coextrusion and then making it porous.
In the present invention, a method using coextrusion is particularly preferred from the viewpoint of simplicity of the process and productivity.

The production method of the laminated porous film of the present invention can be classified by the second layer porosification method separately from the above classification.
That is, since the first layer contains a polypropylene resin (A) having β activity and / or β crystal generation ability, it is possible to easily form micropores by stretching the interface between β crystal and amorphous by stretching. Can do. On the other hand, as a method for making the second layer porous, a known method such as a filler method, a phase separation method, an extraction method, a chemical treatment method, an irradiation etching method, a foaming method, or a combination of these techniques can be used. . Of these, the filler method is preferably used in the present invention.

The filler method is a method in which a non-porous layer or a non-porous film-like material is formed using a composition in which a filler is mixed with a resin, and the interface between the resin and the filler is peeled off to form micropores. is there.
The phase separation method is a technique called a conversion method or a microphase separation method, and forms micropores based on a phase separation phenomenon of a polymer solution. Specifically, it is roughly classified into (a) a method of forming micropores by phase separation of a polymer, and (b) a method of forming pores while forming micropores during polymerization. As the former method, there are a solvent gelation method using a solvent and a hot melt rapid solidification method, and either method may be used.

In the extraction method, an additive that can be removed in a subsequent step is mixed with the thermoplastic resin composition constituting the second layer, and after forming a nonporous layer or a nonporous film, the additive is extracted with a chemical or the like. This is a method for forming fine holes. Examples of the additive include a polymer additive, an organic additive, and an inorganic additive.
As an example using a polymer additive, a non-porous layer or a non-porous film-like material is formed using two types of polymers having different solubility in an organic solvent, and only one of the two types of polymers is used. A method of extracting the one polymer by dipping in a dissolving organic solvent can be mentioned. More specifically, a method of forming a nonporous layer or a nonporous film made of polyvinyl alcohol and polyvinyl acetate, and extracting polyvinyl acetate using acetone and n-hexane, or a block or graft copolymer And a method of forming a non-porous layer or a non-porous film-like material by containing a hydrophilic polymer and removing the hydrophilic polymer with water.

As an example using an organic substance additive, a non-porous layer or a non-porous film-like material is formed by blending a soluble substance in an organic solvent in which the thermoplastic resin constituting the second layer is insoluble, and the organic solvent And a method of extracting and removing the substance by immersing in water.
Examples of the substance include higher aliphatic alcohols such as stearyl alcohol or seryl alcohol, n-alkanes such as n-decane or n-dodecane, paraffin wax, liquid paraffin, or kerosene. These include isopropanol, ethanol, It can be extracted with an organic solvent such as hexane. In addition, water-soluble substances such as sucrose and sugar can also be mentioned as the substances, and these have the advantage of reducing the burden on the environment because they can be extracted with water.

The chemical treatment method is a method of forming micropores by chemically cleaving a part of a polymer substrate or conversely performing a binding reaction. More specifically, a method of forming micropores by chemical treatment such as redox agent treatment, alkali treatment, acid treatment, and the like can be mentioned.
The irradiation etching method is a method of forming minute holes by irradiating with neutron beam or laser.
The fusion method is a method of using a polymer fine powder such as polytetrafluoroethylene, polyethylene, or polypropylene and sintering the polymer fine powder after molding.
Examples of the foaming method include a mechanical foaming method, a physical foaming method, and a chemical foaming method, and any of them can be used in the present invention.

  As a method for producing a laminated porous film of the present invention, mixing a polypropylene resin (A) and a thermoplastic resin (B) having a crystal melting peak temperature lower than that of the polypropylene resin and having a crystal melting peak temperature of 100 ° C. or higher. A thermoplastic resin composition forming a first layer composed of a resin-containing composition, and a second layer in which a filler is blended with a thermoplastic resin (C) having a crystal melting peak temperature higher than that of the polypropylene resin (A). A laminated nonporous film-like material composed of at least two layers of a first layer and a second layer is produced using the thermoplastic resin composition that forms the film, and the laminated nonporous film-like material is stretched in the thickness direction. A method for producing a laminated porous film characterized in that a large number of fine pores having communication properties are formed.

The production method of the laminated non-porous film is not particularly limited, and a known method may be used. For example, the thermoplastic resin composition is melted using an extruder, coextruded from a T die, and cooled and solidified with a cast roll. The method is mentioned. Moreover, the method of cutting open the film manufactured by the tubular method and making it flat is also applicable.
Regarding the stretching method of the laminated non-porous film-like material, there are methods such as a roll stretching method, a rolling method, a tenter stretching method, and a simultaneous biaxial stretching method. Do. Among these, biaxial stretching is preferable from the viewpoint of controlling the porous structure.

  Next, as a more preferable production method, a mixed resin of a polypropylene resin (A) and a thermoplastic resin (B) having a crystal melting peak temperature lower than that of the polypropylene resin and a crystal melting peak temperature of 100 ° C. or higher is included. The thermoplastic resin composition constituting the first layer and the second layer in which the filler is blended with the thermoplastic resin (C) having a higher crystal melting peak temperature than the polypropylene resin (A) are constituted. A laminated nonporous film-like material having a two-layer / three-layer structure is produced by T-die coextrusion so that the thermoplastic resin composition to be made porous by the filler method. A method for producing a laminated porous film that becomes porous by biaxial stretching will be described below.

The thermoplastic resin composition constituting the first layer has a crystal melting peak temperature lower than that of at least the polypropylene resin (A), the β crystal nucleating agent and the polypropylene resin (A), and a crystal melting peak temperature of 100 ° C. or higher and 150 ° C. ℃ it containing a thermoplastic resin (B) is less. These raw materials are preferably mixed using a Henschel mixer, a super mixer, a tumbler type mixer or the like, or mixed by hand blending with all ingredients in a bag, and then preferably a single screw or twin screw extruder, a kneader, etc. Is pelletized after melt-kneading with a twin screw extruder.

  The thermoplastic resin composition constituting the second layer is made of the raw material such as resin (C), filler, plasticizer and other additives as described in the explanation of the second layer, Henschel mixer, super mixer, tumbler type mixer Are mixed using a single screw or twin screw extruder, kneader, etc., preferably melt kneaded with a twin screw extruder, and then pelletized.

The pellets of the resin composition for the first layer and the pellets of the resin composition for the second layer are put into an extruder and extruded from a die for T-die coextrusion. The type of T-die may be a multi-manifold type for type 2 and 3 layers or a feed block type for type 2 and 3 layers.
The gap of the T die to be used is determined from the final required film thickness, stretching conditions, draft rate, various conditions, etc., but is generally about 0.1 to 3.0 mm, preferably 0.5. -1.0 mm. If it is less than 0.1 mm, it is not preferable from the viewpoint of production speed, and if it is larger than 3.0 mm, the draft rate is increased, which is not preferable from the viewpoint of production stability.

In the extrusion molding, the extrusion processing temperature is appropriately adjusted depending on the flow characteristics and moldability of the resin composition, but is generally preferably 180 ° C to 300 ° C, and more preferably in the range of 200 ° C to 280 ° C. A temperature of 180 ° C. or higher is preferable because the melted resin has a sufficiently low viscosity and excellent moldability. On the other hand, at 300 ° C. or lower, the deterioration of the resin composition can be suppressed.
The cooling and solidification temperature by the cast roll is very important in the present invention, and β-crystals of polypropylene resin can be generated and grown, and the ratio of β-crystals in the film-like material can be adjusted. The cooling and solidification temperature of the cast roll is preferably 80 ° C to 150 ° C, more preferably 90 ° C to 140 ° C, and still more preferably 100 ° C to 130 ° C. By setting the cooling and solidifying temperature to 80 ° C. or higher, the ratio of β crystals in the film-like material cooled and solidified can be sufficiently increased, which is preferable. Further, it is preferable to set the temperature to 150 ° C. or lower because troubles such as the extruded molten resin sticking to and wrapping around the cast roll hardly occur and the film can be efficiently formed into a film.

It is preferable that the β crystal ratio of the polypropylene resin (A) of the obtained film-like product before stretching is adjusted to 30 to 100% by setting a cast roll in the temperature range. 40-100% is more preferable, 50-100% is still more preferable, and 60-100% is the most preferable. By setting the β crystal ratio of the polypropylene resin (A) in the film-like material before stretching to 30% or more, a porous porous film can be easily formed by a subsequent stretching operation and has good air permeability. be able to. The β crystal ratio before stretching is derived from the α crystal of polypropylene detected when the film-like material is heated from 25 ° C. to 240 ° C. at a heating rate of 10 ° C./min using a differential scanning calorimeter. Is calculated by the following formula using the heat of crystal fusion (ΔHmα) and the heat of crystal fusion derived from β crystal (ΔHmβ).
β crystal ratio (%) = [ΔHmβ / (ΔHmβ + ΔHmα)] × 100

  Next, the obtained laminated nonporous membrane is biaxially stretched. Biaxial stretching may be simultaneous biaxial stretching or sequential biaxial stretching. In the case of producing a laminated porous film excellent in shutdown characteristics, which is the object of the present invention, sequential biaxial stretching is more preferable because the stretching conditions can be selected in each stretching step and the porous structure can be easily controlled. In addition, stretching in the film take-up (flow) direction is referred to as “longitudinal stretching”, and stretching in the perpendicular direction is referred to as “lateral stretching”.

When using sequential biaxial stretching, the stretching temperature needs to be selected as appropriate depending on the composition of the resin composition used, the crystal melting peak temperature of the resin (B) and the resin (C), the degree of crystallinity, etc. The stretching temperature is generally controlled in the range of 20 ° C to 130 ° C, preferably 40 ° C to 120 ° C, more preferably 60 ° C to 110 ° C. The longitudinal draw ratio is preferably 2 to 10 times, more preferably 3 to 8 times, and still more preferably 3 to 7 times. By performing longitudinal stretching within the above range, it is possible to develop an appropriate pore starting point while suppressing breakage during stretching. On the other hand, the stretching temperature in transverse stretching is generally 100 to 160 ° C, preferably 110 to 150 ° C, and more preferably 120 to 140 ° C. The transverse draw ratio is preferably 2 to 10 times, more preferably 3 to 8 times, and further preferably 3 to 7 times. By transversely stretching within the above range, the pore starting point formed by longitudinal stretching can be appropriately expanded, and a porous film having fine pores and a high strength of the fiber skeleton can be obtained. In addition, it has an air permeability characteristic and mechanical strength, and can make it easy to exhibit a shutdown characteristic.
The stretching speed in the stretching step is preferably 500 to 12000% / min, more preferably 1500 to 10,000% / min, and further preferably 2500 to 8000% / min.

  The laminated porous film thus obtained is preferably heat-treated at a temperature of about 100 ° C. to 170 ° C., preferably about 120 ° C. to 170 ° C. for the purpose of improving dimensional stability. During the heat treatment step, a relaxation treatment of 1 to 15% may be performed as necessary. The laminated porous film of the present invention can be obtained by uniformly cooling and winding after this heat treatment.

  The laminated porous film of the present invention can be applied to various uses that require air permeability. Battery separators; Sanitary materials such as disposable paper diapers and sanitary items such as pads and bed sheets for absorbing body fluids; Medical materials such as surgical clothing or base materials for hot compresses; Materials for clothing such as jumpers, sportswear, and rainwear ; Building materials such as wallpaper, roof waterproofing material, heat insulating material, sound absorbing material; desiccant; moisture-proofing agent; oxygen scavenger; disposable body warmer; can be used very suitably as a material for packaging materials such as freshness preservation packaging or food packaging .

Especially, the lamination | stacking porous film of this invention is used suitably as a separator for nonaqueous electrolyte batteries, such as a lithium ion secondary battery utilized as power supplies, such as various electronic devices.
When used as the battery separator, the air permeability resistance is preferably 5 to 3000 seconds / 100 ml, more preferably 20 to 2000 seconds / 100 ml, still more preferably 50 to 1000 seconds / 100 ml, Most preferably, it is 50 to 500 seconds / 100 ml.
If the air resistance is larger than 3000 seconds / 100 ml, the numerical value of air resistance is obtained in the measurement, but it indicates that the structure is quite poor in communication, so it can be practically used as a lithium ion battery separator. There is often no degree of connectivity. That is, it is preferable that the air permeation resistance is 3000 seconds / 100 ml or less because ion conductivity can be secured and sufficient battery characteristics can be obtained. On the other hand, if the air permeation resistance is 5 seconds / 100 ml or more, it is preferable because the pore diameter is appropriately small and the mechanical strength of the separator can be maintained.
In the case of using the laminated porous film of the present invention as a battery separator, a porosity Ru 3 5 to 65% der. If the porosity is 35 % or more, ion permeability can be secured and sufficient battery performance can be obtained. On the other hand, Ru der porosity of 65% or less from the viewpoint of safety of the battery.

[Explanation of battery separator]
Next, a non-aqueous electrolyte battery containing the laminated porous film of the present invention as a battery separator will be described with reference to FIG.
Both electrodes of the positive electrode plate 21 and the negative electrode plate 22 are wound in a spiral shape so as to overlap each other via the battery separator 10, and the outside is stopped with a winding tape to form a wound body. When winding in this spiral shape, the battery separator 10 preferably has a thickness of 5 to 40 μm, particularly preferably 5 to 30 μm. When the thickness is 5 μm or more, the battery separator is not easily broken, and when the thickness is 40 μm or less, the battery area when wound in a predetermined battery can can be increased, thereby increasing the battery capacity. Can do.

  A wound body in which the positive electrode plate 21, the battery separator 10 and the negative electrode plate 22 are integrally wound is housed in a bottomed cylindrical battery case and welded to the positive and negative electrode lead bodies 24 and 25. Next, the electrolyte is injected into the battery can, and after the electrolyte has sufficiently penetrated into the battery separator 10 or the like, the positive electrode lid 27 is sealed around the opening periphery of the battery can via the gasket 26, and precharging and aging are performed. A cylindrical non-aqueous electrolyte battery is manufactured.

As the electrolytic solution, an electrolytic solution in which a lithium salt is used as an electrolytic solution and is dissolved in an organic solvent is used. The organic solvent is not particularly limited, but for example, propylene carbonate, ethylene carbonate, butylene carbonate, γ-butyrolactone, γ-valerolactone, esters such as dimethyl carbonate, methyl propionate or butyl acetate, and nitriles such as acetonitrile. 1,2-dimethoxyethane, 1,2-dimethoxymethane, dimethoxypropane, 1,3-dioxolane, ethers such as tetrahydrofuran, 2-methyltetrahydrofuran or 4-methyl-1,3-dioxolane, or sulfolane These may be used alone or in combination of two or more.
Among them, an electrolyte obtained by dissolving lithium hexafluorophosphate (LiPF ₆₎ at a rate of 1.4 mol / L in a solvent obtained by mixing 2 parts by mass of methyl ethyl carbonate relative to ethylene carbonate 1 part by weight is preferred.

As the negative electrode, an alkali metal or a compound containing an alkali metal integrated with a current collecting material such as a stainless steel net is used. Examples of the alkali metal include lithium, sodium, and potassium. Examples of the compound containing an alkali metal include an alloy of an alkali metal and aluminum, lead, indium, potassium, cadmium, tin or magnesium, a compound of an alkali metal and a carbon material, a low potential alkali metal and a metal oxide, and the like. Or a compound with a sulfide or the like.
In the case of using a carbon material for the negative electrode, the carbon material may be any material that can be doped and dedoped with lithium ions. Mesocarbon microbeads, carbon fibers, activated carbon and the like can be used.

  In this embodiment, as a negative electrode, a carbon material having an average particle size of 10 μm is mixed with a solution in which vinylidene fluoride is dissolved in N-methylpyrrolidone to form a slurry, and this negative electrode mixture slurry is passed through a 70-mesh net. After removing the large particles, uniformly apply to both sides of the negative electrode current collector made of a strip-shaped copper foil having a thickness of 18 μm and dry, and then compression-molded with a roll press machine, cut, strip-shaped negative electrode plate and We use what we did.

  As the positive electrode, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, manganese dioxide, metal oxide such as vanadium pentoxide or chromium oxide, metal sulfide such as molybdenum disulfide, etc. are used as active materials. , These positive electrode active materials are combined with conductive additives and binders such as polytetrafluoroethylene as appropriate, and finished with a current collector material such as a stainless steel mesh as a core material. It is done.

In the present embodiment, a strip-like positive electrode plate produced as follows is used as the positive electrode. That is, lithium graphite oxide (LiCoO ₂ ) is added with phosphorous graphite as a conductive additive at a mass ratio of 90: 5 (lithium cobalt oxide: phosphorous graphite) and mixed, and this mixture and polyvinylidene fluoride are mixed with N -Mix with a solution dissolved in methylpyrrolidone to make a slurry. This positive electrode mixture slurry is passed through a 70-mesh net to remove large particles, and then uniformly applied to both sides of a positive electrode current collector made of an aluminum foil having a thickness of 20 μm, dried, and then compressed by a roll press. After forming, it is cut into a strip-like positive electrode plate.

[Description of Examples]
Next, although an Example and a comparative example are shown and it demonstrates in detail about the laminated porous film of this invention, this invention is not limited to these.
The take-up (flow) direction of the laminated porous film is referred to as a “longitudinal” direction, and the direction perpendicular thereto is referred to as a “lateral” direction.

Each raw material of the first layer shown in Table 1 was placed in a unidirectional twin screw extruder (caliber: 30 mmφ, L / D = 30) manufactured by Technobel, and the pellets for the second layer shown below were manufactured by Toshiba Machine Co., Ltd. Throw in a twin-screw extruder in the same direction (caliber 40mmφ, L / D = 32), melt and mix at 280 ° C, then extrude from a T-die through a single-layer, 2-type 2-layer or 2-type 3-layer feed block. The film was taken up with a cast roll and solidified by cooling to obtain a film-like product having a width of 300 mm and a thickness of 180 μm.
The obtained film-like material was subjected to longitudinal stretching at a temperature and a stretching ratio between rolls using a roll longitudinal stretching machine, and then stretched at a temperature and a stretching ratio in a film tenter facility manufactured by Kyoto Machine Co., Ltd. Then, thermal relaxation was performed to obtain a laminated porous film.

The raw material for the first layer is specifically as follows.
In addition, about each polypropylene resin (PP-1, (beta) PP-1, (beta) PP-2), it heats from 25 degreeC to 240 degreeC using the differential scanning calorimeter (DSC-7) by Parkin Elmer. The temperature is raised at a rate of 10 ° C./min and held for 1 minute, then the temperature is lowered from 240 ° C. to 25 ° C. at a cooling rate of 10 ° C./min. Whether or not a crystal melting peak (Tmβ) derived from the β crystal is detected in the range of 145 ° C. or higher and lower than 160 ° C. when the temperature is increased again is described.

(A) Polypropylene resin / PP-1: “Prime PP F300SV (trade name)” manufactured by Prime Polypro Co., Ltd. (MFR 3.0 g / 10 min)
At the time of reheating, only the crystal melting peak temperature (Tmα) derived from polypropylene α crystal was detected at 166 ° C., and the crystal melting peak temperature (Tmβ) derived from β crystal was not detected. That is, PP-1 alone did not have β activity.
・ ΒPP-1
N, N′-dicyclohexyl-2,6-naphthalenedicarboxylic acid amide (β1), which is a β crystal nucleating agent, is added to the polypropylene resin (PP-1) in a mass ratio of PP-1 / β1 = 100 / 0.1. Blended at a ratio, put into a twin-screw extruder manufactured by Toshiba Machine Co., Ltd. (caliber 40 mmφ, L / D = 32), melted and mixed at a set temperature of 280 ° C., cooled and solidified in a water tank, and then solidified with a pelletizer The strand was cut to produce a mixed pellet of polypropylene resin (PP-1) and β crystal nucleating agent.
At the time of reheating, a crystal melting peak temperature (Tmβ) derived from polypropylene β crystal was detected at 154 ° C., and a crystal melting peak temperature (Tmα) derived from α crystal was detected at 168 ° C.
That is, βPP-1 has β activity, and the β activity calculated from the following formula was 80%.
β activity (%) = [ΔHmβ / (ΔHmβ + ΔHmα)] × 100
ΔHmβ: Crystal heat of fusion derived from β crystal detected in a range of 145 ° C. or higher and lower than 160 ° C. ΔHmα: Crystal heat of fusion derived from α crystal detected from 160 ° C. or higher and 175 ° C. or lower; βPP-2: β crystal nucleating agent Pellets of “Bepol B-022SP (trade name)” (MFR 0.3 g / 10 min) manufactured by Aristech, which is a blended polypropylene resin, were used.
At the time of reheating, the crystal melting peak temperature (Tmβ) derived from the β crystal of polypropylene was detected at 151 ° C., and the crystal melting peak temperature (Tmα) derived from the α crystal was detected at 169 ° C.
That is, βPP-2 has β activity, and the β activity calculated from the above formula was 78%.
(B) Resin having a crystal melting peak temperature lower than that of polypropylene resin and having a crystal melting peak temperature of 100 ° C. or higher. PE-1: High-density polyethylene “Hi-Zex HZ2200J (trade name)” manufactured by Prime Polymer Co., Ltd. (MFR 5.2 g) / 10 min, Tm 134 ° C., density 0.964 g / cm ³ )
PE-2: Ube Industries, Ltd. linear low density polyethylene “Umerit 3540F (trade name)” (MFR 4.0 g / 10 min, Tm 123 ° C., density 0.931 g / cm ³ )
PE-3: linear low density polyethylene “Carnel KF260 (trade name)” manufactured by Nippon Polyethylene Co., Ltd. (MFR 2.0 g / 10 min, Tm 93 ° C., density 0.903 g / cm ³ )
PP-2: Metallocene polypropylene “Wintech WFX6 (trade name)” manufactured by Nippon Polypro Co., Ltd. (MFR 2.0 g / 10 min, Tm 125 ° C., density 0.900 g / cm ³ )

The following materials were used as raw materials for the second layer.
(C) Resin having higher crystal melting peak temperature than polypropylene resin HR-1: Polymethylpentene “TPX RT-18 (trade name)” (MFR 26 g / 10 min, density 0.833 g / cm ³ , manufactured by Mitsui Chemicals, Inc.) Tm237 ° C)
(D) Filler, FL-1: Barium sulfate “B55 (trade name)” manufactured by Sakai Chemical Co., Ltd.
(Average particle size 0.66μm)
(E) Plasticizer / PL-1: “High Castor Wax HCOP (trade name)” manufactured by Toyokuni Seiyaku Co., Ltd.

(Preparation of pellet for second layer)
The above-mentioned raw materials are hand blended so that the mass ratio is HR-1 / FL-1 / PL-1 = 47.5 / 50 / 2.5, and the same-direction twin-screw extruder (caliber) manufactured by Technobel Co., Ltd. 30 mmφ, L / D = 30) and kneaded at 280 ° C. to prepare pellets for the second layer.
In Table 1, the pellet was designated as HR-CPD1.

  The obtained films of Examples and Comparative Examples were measured and evaluated for various properties as follows, and the results are summarized in Tables 1 and 2.

(1) Shutdown characteristics The obtained film was cut into 60 mm × 60 mm square, and as shown in FIG. 2 (A), an aluminum plate (material: JIS standard A5052, Size: 60 mm long, 60 mm wide, 1 mm thick) sandwiched between two sheets and restrained by a clip (made by KOKYO Corporation, double clip “Kuri-J35 (trade name)”) as shown in FIG. 2 (B) .
Put the sample restrained by two aluminum plates into an oven set at 100 ° C or 160 ° C (Tabay Espec, Tabai Gear Oven "GPH200", damper closed), and the oven internal temperature rises to each temperature Then, after being held for 3 minutes, it was immediately taken out and cooled in an atmosphere at 25 ° C. for 30 minutes in a restrained state. Then, the sample was taken out from the aluminum plate, and the air resistance of the laminated porous film was measured in accordance with JIS P8117 for the central circular portion of 40 mmΦ.
The case where the air resistance after the high-temperature heat treatment was 10 times or more of the air resistance before the heating was marked with ●, and the case where it was less than 10 times was marked with ○.
The preferred shutdown temperature range in the present invention is more than 100 ° C. and not more than 160 ° C. Therefore, in this evaluation, the air resistance does not increase at 100 ° C., and the air resistance increases at 160 ° C. due to the shutdown. ● is preferred.
When the film piece cannot be cut into a 60 mm × 60 mm square, the sample may be prepared by adjusting so that the film is placed in a circular hole of 40 mmΦ in the center.

(2) Breakdown characteristics An oven (Tabai gear spec "GPH200" manufactured by Tabay Espec Co., Ltd.) with a film constrained by two aluminum plates set at 200 ° C in the same manner as in Figs. The damper was in a closed state), and after 2 minutes after the oven set temperature reached 200 ° C. again, the film was taken out and the state of the film was confirmed to determine the shape maintenance performance.
When the film was broken, it was evaluated as “X”, and when the shape was maintained, it was evaluated as “◯”.

(3) Layer ratio A cross section of the laminated porous film was cut out and observed with a scanning electron microscope (S-4500, manufactured by Hitachi, Ltd.), and the layer ratio was measured from the layer configuration and thickness.

(4) Thickness A thickness of 1/1000 mm was used to measure 30 in-plane thicknesses unspecified, and the average was taken as the thickness.

(5) Air permeability resistance (Gurley value)
The air resistance (second / 100 ml) was measured according to JIS P8117. In addition to the measurement values, the evaluation was performed according to the following criteria.
A: Air permeability resistance is 500 seconds / 100 ml or less. ○: Air resistance exceeds 500 seconds / 100 ml and is 10,000 seconds / 100 ml or less. X: Air resistance exceeds 10,000 seconds / 100 ml.

(6) Pin puncture strength According to Japanese Agricultural Standards Notification No. 1019, the pin puncture strength was measured under the conditions of a pin diameter of 1.0 mm, a tip portion of 0.5R, and a pin puncture speed of 300 mm / min. In addition to the measurement values, the evaluation was performed according to the following criteria.
◎: Pin puncture strength is 3.0N or more ○: Pin puncture strength is 1.5N or more and less than 3.0N ×: Pin puncture strength is less than 1.5N

(7) Porosity The porosity is a numerical value indicating the proportion of the space portion in the film. The porosity was determined by measuring the substantial amount W1 of the film, calculating the mass W0 when the porosity was 0% from the density and thickness of the resin composition, and calculating from these values based on the following formula.
Porosity Pv (%) = {(W0−W1) / W0} × 100

(8) β activity Using a differential scanning calorimeter (DSC-7) manufactured by Perkin Elmer Co., Ltd., the temperature was raised from 25 ° C. to 240 ° C. at a heating rate of 10 ° C./min and held for 1 minute. Then, the temperature was lowered from 240 ° C. to 25 ° C. at a cooling rate of 10 ° C./min and held for 1 minute, and further heated from 25 ° C. to 240 ° C. at a heating rate of 10 ° C./min. The presence or absence of β activity was evaluated as follows depending on whether or not a peak was detected at 145 ° C. to 160 ° C. which is the crystal melting peak temperature (Tmβ) derived from the β crystal of polypropylene at the time of reheating.
○: When Tmβ is detected within the range of 145 ° C to 160 ° C (with β activity)
X: When Tmβ is not detected within the range of 145 ° C to 160 ° C (no β activity)
Note that the β activity was measured with a sample amount of 10 mg and the atmosphere gas as nitrogen.

(9) β Crystal Forming Power As in the case of the measurement of the shutdown characteristics and breakdown characteristics, the film was cut into a 60 mm × 60 mm square and fixed as shown in FIGS.
The film in a state of being restrained by two aluminum plates is placed in a ventilation constant temperature thermostat (model DKN602, manufactured by Yamato Kagaku Co., Ltd.) having a set temperature of 180 ° C. and a display temperature of 180 ° C., and held for 3 minutes. The temperature was changed and gradually cooled to 100 ° C. over 10 minutes. When the display temperature reaches 100 ° C., the film is taken out and cooled in an atmosphere of 25 ° C. for 5 minutes while being restrained by two aluminum plates. Wide-angle X-ray measurement was performed on a 40 mmφ circular portion.
-Wide-angle X-ray measuring device: manufactured by Mac Science Co., Ltd. Model No. XMP18A
X-ray source: CuKα ray, output: 40 kV, 200 mA
Scanning method: 2θ / θ scan, 2θ range: 5 ° to 25 °, scanning interval: 0.05 °, scanning speed: 5 ° / min
About the obtained diffraction profile, the presence or absence of the β crystal generation force was evaluated from the peak derived from the (300) plane of the β crystal of polypropylene as follows.
◯: When a peak is detected in the range of 2θ = 16.0 to 16.5 ° (with β-crystal forming power)
X: When a peak is not detected in the range of 2θ = 16.0 to 16.5 ° (no β crystal formation ability)
When the film piece cannot be cut into a 60 mm × 60 mm square, the sample may be prepared by adjusting so that the film is placed in a circular hole of 40 mmΦ in the center.

As shown in Table 2, Comparative Example 1 using polyethylene having a crystal melting peak temperature of 93 ° C. closed the pores at 100 ° C., and exhibited shutdown characteristics in a temperature range exceeding 100 ° C. and below 160 ° C. I did not. Furthermore, it was not possible to achieve sufficient porosity, and the air resistance was extremely large.
In Comparative Example 2 in which the resin (B) was not blended and the second layer was not further laminated, the pores were not blocked even at 160 ° C., and the shutdown characteristics were exhibited in the temperature range of 100 ° C. to 160 ° C. There wasn't. In addition, the heat resistance was poor, the film was broken at 200 ° C., and the breakdown characteristics were not sufficient.
In Comparative Example 3 in which the second layer was not laminated, the heat resistance was poor, the film was broken at 200 ° C., and the breakdown characteristics were not sufficient. Furthermore, the pin puncture strength was as low as less than 1.5N, and the strength was insufficient.
On the other hand, Examples 1 to 5 of the present invention have air permeability resistance suitable as a battery separator, and also have moderate strength, and have both shutdown characteristics and breakdown characteristics. It was excellent.

  Since the laminated porous film of the present invention has excellent air permeability and mechanical strength, and has shutdown characteristics and breakdown characteristics, it can be suitably used as a battery separator.

It is a partially broken perspective view of the nonaqueous electrolyte battery which has stored the lamination porous film of the present invention as a battery separator. (A) (B) is a figure explaining the restraint method of the film in the measurement of the shutdown characteristic in the Example, a breakdown characteristic, and (beta) crystal formation power.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Battery separator 20 Nonaqueous electrolyte battery 21 Positive electrode plate 22 Negative electrode plate

Claims (9)

A laminated porous film in which at least two porous layers are laminated,
A β crystal nucleating agent is blended in a composition including a mixed resin of a polypropylene resin and a resin having a crystal melting peak temperature lower than that of the polypropylene resin and a crystal melting peak temperature of 100 ° C. or higher and 150 ° C. or lower , The mixing mass ratio of the polypropylene resin and the resin having a crystal melting peak temperature of 100 ° C. or more and 150 ° C. or less is polypropylene resin / resin having a crystal melting peak temperature of 100 ° C. or more and 150 ° C. or less = 20-80 / 80. A first layer of ~ 20 ;
And a second layer crystal melting peak temperature of a composition containing a resin having the polypropylene-based resin by Ri have high 175 ° C. or higher,
The shutdown temperature for closing the hole is in the range of more than 100 ° C. and 160 ° C. or less, and the breakdown temperature, which is the temperature at which the film breaks, is 200 ° C. or more,
A laminated porous film having a porosity of 35 to 65% , a pin puncture strength of 1.5 N or more, and β activity and / or β crystal generation ability . The resin of the second layer is a thermoplastic resin, and 50 parts by mass or more of an inorganic filler having an average particle size of 0.5 to 5 μm is blended with 100 parts by mass of the resin of the second layer. The laminated porous film described . The β crystal nucleating agent is blended at a ratio of 0.0001 to 5.0 parts by mass with respect to 100 parts by mass of the polypropylene resin, and has the β activity and / or the β crystal generation power. 3. The laminated porous film according to 1 or 2. The laminated porous film according to any one of claims 1 to 3, wherein the resin having a crystal melting peak temperature of 100 ° C or higher and 150 ° C or lower is a polyethylene resin . The resin having a crystal melting peak temperature of 175 ° C or higher is at least one selected from the group consisting of polyester resins, polystyrene resins, fluorine resins, and polymethylpentene resins . The laminated porous film according to any one of the above. 6. The laminate according to claim 1, which is a two-layer structure in which the first layer and the second layer are stacked, or a three-layer stack in which the first layer is sandwiched between the second layers. Laminated porous film. The laminated porous film according to any one of claims 1 to 6, which has an air permeability resistance of 1 to 10,000 seconds / 100 ml . A battery separator comprising the laminated porous film according to any one of claims 1 to 7, wherein the air permeability resistance is 5 to 3000 seconds / 100 ml . A battery comprising the battery separator according to claim 8 incorporated therein .

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