JP2002234963A - Extractant composition for porous molded product made of thermoplastic resin and method for producing porous molded product made of thermoplastic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extractant composition which is used for producing a porous molded product made of a thermoplastic resin suitable for battery separators or filters, and a method for producing the porous molded product made of a thermoplastic resin. SOLUTION: The extractant composition for a thermoplastic resin porous molded product comprises (A) 5-50 mass% anionic surface active agent, (B) 5-90 mass% alkylene oxide derivative represented by formula (I): R-(R1O)m-R2 (wherein R is a 1-10C alkyl group or an alkenyl group; R1 is a 2-4C alkylene group; m is a number of 1-8; and R2 is a hydrogen atom or a 1-3C alkyl group), and (C) 5-45 mass% water. The method for producing a thermoplastic resin porous molded product comprises treating a gelled molded product obtained by melt kneading a thermoplastic resin and a plasticizer with the above extractant composition heated at a temperature of not lower than the melting point of the plasticizer to remove the above plasticizer and to obtain a porous molded product. Accordingly, the plasticizer can be efficiently and surely removed without using an organic solvent or the like. Further, efficient thermoplastic resin porous molded products can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extractant composition used in a process for producing a thermoplastic resin porous molded article suitable for a battery separator, a filter, and the like, and a method for producing a thermoplastic resin porous molded article.

[0002]

2. Description of the Related Art Conventionally, porous molded articles of thermoplastic resins have been used for battery separators, diaphragms for electrolytic capacitors, separation membranes, water treatment membranes, reverse osmosis membranes, ultrafiltration membranes, microfiltration membranes, moisture-permeable waterproof clothing. It is used for various applications such as.

Generally, a porous molded article of a thermoplastic resin is
A film or sheet is formed from a resin composition comprising a thermoplastic resin and a plasticizer such as paraffin oil, and then the plasticizer contained in the film or sheet is methylene chloride,
It is manufactured by treating with an organic solvent such as isopropyl alcohol, ethanol, and hexane, and extracting and removing it.

However, the organic solvents used in the conventional plasticizer removal process are flammable, harmful to the human body, cause air pollution of these solvents, and cause environmental pollution such as ozone destruction. There is a problem in that respect. Therefore, safety and hygiene handling equipment for handling is required. In particular, recovery of the solvent after extraction is indispensable for environmental measures, and therefore, a large amount of equipment accompanying production is required.

On the other hand, JP-A-6-256559 discloses paraffin wax, stearyl alcohol, etc., which are hardly soluble in water, have a melting point of 100 ° C. or less, and are compatible with the matrix resin under the conditions of melt-kneading the matrix resin. By adding a compound (plasticizer) to the matrix resin and molding, and treating the resulting molded article with an aqueous solution of a surfactant heated to a temperature equal to or higher than the melting point of the compound,
A method for producing a porous resin molded article, which comprises removing the compound from the molded article to obtain a porous molded article, is disclosed. Examples of the surfactant include sodium carboxylate and an anion such as sodium sulfonate. Anionic surfactants forming amino groups, imide groups, quaternary ammonium bases, etc., and nonionic surfactants such as polyoxyethylene glycol type and polyhydric alcohol type are used. In Examples 1 and 2, an aqueous solution containing 4% or 2% sodium alkylbenzenesulfonate is used.

However, the aqueous solution of a surfactant species disclosed in the above publication has a problem in that the removal efficiency of a compound (plasticizer) such as paraffin wax or stearyl alcohol is poor, and a desired porous resin molded article cannot be obtained. There is little practicality.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has been made to solve the problem. An object of the present invention is to provide an extractant composition for efficiently and surely removing a plasticizer without using it, and to provide a method for efficiently producing a thermoplastic resin porous molded article using the extractant composition.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on the above-mentioned problems of the prior art and the like, and as a result, as an extractant composition used in the production process of a thermoplastic resin porous molded article, a specific composition has been developed. By using a surfactant type or a combination thereof as an aqueous solution or a water emulsion in a specific amount range, respectively, it is excellent in stability over time, and is also found to be excellent in removing efficiency of a plasticizer. The present invention has been completed by finding that a thermoplastic resin porous molded article can be efficiently produced by using this extractant composition. That is, the present invention provides the following [1] to
[4]. [1] An extractant composition for a thermoplastic resin molded article, comprising the following (A) to (C): (A); 5 to 50% by mass of anionic surfactant (B); 5 to 90% by mass of alkylene oxide derivative represented by the following formula (I)

Embedded image (C); 5 to 45% by mass of water [2] An extractant composition for a thermoplastic resin porous molded body, which comprises the following (D) and (E). (D); 65 to 95% by mass of a nonionic surfactant represented by the following formula (II)

Embedded image (E); water 5 to 35% by mass [3] The gel-like molded body obtained by melting and kneading a thermoplastic resin and a plasticizer is heated to a temperature equal to or higher than the melting point of the plasticizer. ] The extractant composition according to the present invention, or a thermoplastic resin obtained by treating the composition with a water diluent to remove the plasticizer from the molded article to obtain a porous molded article. A method for producing a molded article. [4] The method for producing a porous thermoplastic resin article according to [3], wherein the remaining plasticizer is removed before and / or after stretching the gel-like molded article. A method for producing a porous molded body.

[0009]

Embodiments of the present invention will be described below in detail. The extractant composition for a thermoplastic resin porous molded article of the present invention includes a battery separator, a diaphragm for an electrolytic capacitor, a separation membrane, a water treatment membrane, a reverse osmosis membrane, an ultrafiltration membrane, a microfiltration membrane, a moisture-permeable waterproof clothing, and the like. An extractant composition used in a manufacturing process of a thermoplastic resin molded article used for various applications of the present invention, and contains the following components (A) to (C) as the extractant composition of the first invention. In addition, the extractant composition of the second invention comprises the following components (D) and (E). (A); 5 to 50% by mass of anionic surfactant (hereinafter abbreviated as mass) (B); 5 to 90% of alkylene oxide derivative represented by the following formula (I)

Embedded image (C); water 5-45% (D); nonionic surfactant represented by the following formula (II) 65-95%

Embedded image (E); water 5 to 35% A method for producing the thermoplastic resin porous molded article of the present invention (hereinafter, referred to as “the present invention method”), a gel obtained by melt-kneading the thermoplastic resin and the plasticizer. The plasticizer is treated with the extractant composition of the first or second invention heated above the melting point of the plasticizer or with a water diluent of each of the above-mentioned plasticizers, whereby the plasticizer is molded. , To obtain a porous molded body.

The anionic surfactant used as the component (A) in the extractant composition of the first invention of the present invention includes, for example, alkyl benzene sulfonate, alkyl ether sulfate, polyoxyethylene alkyl sulfate, alkyl sulfate Salt, alkenyl sulfate, amino acid surfactant, α
-Olefin sulfonate, α-sulfo fatty acid salt, α-
Examples include at least one of sulfo fatty acid ester salts, alkyl ether carboxylate salts, alkenyl ether carboxylate salts, alkyl phosphate ester salts, sulfosuccinate ester salts, paraffin sulfonate salts, soaps, and the like. Sulfosuccinate and paraffin sulfonate are preferred from the viewpoint of their removability from water. It is desirable that the content of these anionic surfactants is 5 to 50%, preferably 10 to 40%, based on the total amount of the extractant composition (100%, the same applies hereinafter). If the content of the anionic surfactant is less than 5%, the removability of the plasticizer from the molded product is insufficient, which is not preferable.
If it exceeds 0%, the viscosity of the extractant composition becomes large, which is not preferable.

The alkylene oxide derivative represented by the above formula (I) as the component (B) used in the extractant composition of the first invention of the present invention includes, for example, ethyl diethylene glycol, ethyl triethylene glycol, ethyl dipropylene glycol , Ethyl tripropylene glycol,
Ethyl dibutylene glycol, ethyl tributylene glycol, dimethyl diethylene glycol, dimethyl triethylene glycol, dimethyl dipropylene glycol, dimethyl tripropylene glycol, dimethyl dibutylene glycol, dimethyl tributylene glycol,
Propyl diethylene glycol, propyl triethylene glycol, isopropylene diethylene glycol, isopropyl dipropylene glycol, isopropyl tripropylene glycol, isopropyl dibutylel glycol, isopropyl tributylene glycol, butyl diethylene glycol, butyl triethylene glycol,
Butyl tetrabutylene glycol, butyl dipropylene glycol, butyl tripropylene glycol, isobutyl diethylene glycol, isobutyl triethylene glycol, isobutyl dipropylene glycol, isobutyl tripropylene glycol, isobutyl dibrene glycol, dibutyl diethylene glycol, dibutyl triethylene glycol, hexyl diethylene glycol, hexyl Triethylene glycol, hexyl tetraethylene glycol, hexyl pentaethylene glycol, hexyl heptaethylene glycol, hexyl octaethylene glycol, hexyl dipropylene glycol, hexyl tripropylene glycol, 2 ethyl hexyl diethylene glycol, 2 ethyl hexyl triethylene glycol, Hexyl tetraethylene glycol, 2-ethylhexyl pentaethylene glycol,
2-ethylhexyl heptaethylene glycol, 2 ethylhexyl octaethylene glycol, 2 ethylhexyl dipropylene glycol, 2 ethylhexyl tripropylene glycol, allyl diethylene glycol, allyl triethylene glycol, allyl dipropylene glycol, allyl tripropylene glycol, ethylene glycol dipropylene glycol butyl ether, diethylene glycol At least one of monopropylene glycol butyl ether, diethylene glycol dipropylene glycol hexyl ether, dipropylene glycol diethylene glycol hexyl ether and the like can be mentioned. Among them, particularly, R is an alkyl group having 1 to 8 carbon atoms, R ₁ is ethylene or propylene, m is a number of 1 to 6, and R _{2 is}
Is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

It is desirable that the content of these alkylene oxide derivatives is 5 to 90%, preferably 10 to 60%, based on the total amount of the extractant composition. If the content of the alkylene oxide derivative is less than 5%, the viscosity of the extractant composition becomes large, which is not preferable. If it exceeds 90%, the removability of the plasticizer from the molded article becomes poor, which is not preferable.

The water used as the component (C) used in the extractant composition of the first invention of the present invention includes, for example, purified water, ion-exchanged water and pure water. The water content is
5-45% with respect to the total amount of the extractant composition, preferably
It is desirable to set it to 10 to 30%. If the water content is less than 5%, the removability of the plasticizer from the molded article becomes poor, which is not preferable. If it exceeds 45%, the removability of the plasticizer from the molded article becomes poor, which is not preferable. .

The nonionic surfactant used as the component (D) in the extractant composition of the second invention of the present invention is represented by the above formula (II)
And an alkylene oxide adduct of a long-chain alcohol. Specifically, polyoxyethylene (8) lauryl ether, polyoxyethylene (9) secondary alkyl (C12-14) ether, polyoxyethylene (15) secondary alkyl (C1
2-14) Polyoxyalkylene alkyl ether such as ether, polyoxyethylene (20) polyoxypropylene (7) tridodecyl ether, polyoxyethylene (9) polyoxypropylene (5) secondary alkyl (C12-14) And polyoxyethylene polyoxypropylene alkyl ethers such as ether.

The content of the nonionic surfactant represented by the above formula (II) is 6 to the total amount of the extractant composition.
It is desirably 5 to 95%, preferably 75 to 95%. If the content of the nonionic surfactant is less than 65%, the removability of the plasticizer from the molded article becomes poor, which is not preferable. If it exceeds 95%, the viscosity of the extractant composition becomes large, which is not preferable. .

As the water used as the component (E) used in the extractant composition of the second invention of the present invention, purified water, ion-exchanged water, pure water and the like can be mentioned as in the case of the component (C). . The water content of the component (E) is desirably 5 to 35%, preferably 5 to 25%, based on the total amount of the extractant composition. If the water content is less than 5%, the viscosity of the extractant composition becomes large, which is not preferable.
Exceeding the range is not preferred because the plasticizer has poor removability from the molded article. In addition, the range of the content of water of the component (E) used in the extractant composition of the second invention of the present invention and the range of the content of the component (C) used in the extractant composition of the first invention are described. The difference is based on the difference in the compound type and the compound composition.

The extractant composition of the first or second invention forms a low-viscosity, uniformly transparent liquid or a uniform microemulsion. The viscosity of the extractant composition in the first invention and the second invention is preferably 25 ° C.
In this case, it is preferable that the pressure be 2000 mPa · s or less. In addition, in addition to the above components, for example, solvents such as ethanol, isopropanol, ethylene glycol, and propylene glycol can be appropriately added to the present extractant compositions as long as the object of the present invention is not impaired.

Next, examples of the thermoplastic resin used in the method of the present invention include polyolefin resins such as polyethylene and polypropylene, polyester resins, polyamide resins and the like. Preferably, a polyolefin resin is desirable in view of moldability and performance of the obtained porous molded article as a battery separator. These resins may be used alone or as a composition in which two or more kinds are mixed.

The polyolefin composition that can be used in the method of the present invention includes, for example, a polyolefin having a weight average molecular weight of 500,000 or more or a polyolefin composition containing a polyolefin having a weight average molecular weight of 500,000 or more. When a polyolefin having a mass-average molecular weight of 500,000 or more is not contained, it is difficult to obtain a suitable porous molded article because the sheet is likely to break during stretching. Although the upper limit of the mass average molecular weight is not particularly limited, melt extrusion can be facilitated by setting the upper limit to 15,000,000 or less.

As the polyolefin having a mass average molecular weight of 500,000 or more, ultrahigh molecular weight polyethylene is preferably used. Examples of the polyolefin composition containing a polyolefin having a mass average molecular weight of 500,000 or more include a composition comprising a polyolefin having a mass average molecular weight of 500,000 or more and a polyolefin having a mass average molecular weight of 10,000 to less than 500,000. The polyolefin having a weight average molecular weight of 10,000 or more and less than 500,000 is not particularly limited, but polyethylene is preferred. As the type of polyethylene,
For example, high-density polyethylene, low-density polyethylene, and medium-density polyethylene are mentioned. These may be not only a homopolymer of ethylene but also a copolymer containing a small amount of another α-olefin. Further, as other α-olefins other than ethylene, for example, propylene, butene-1, hexene-1, pentene-1, 4-methylpentene-1, octene, vinyl acetate, methyl methacrylate, and styrene are preferable. . In addition, mass average molecular weight 50
10,000 or more polyolefin and mass average molecular weight 10,000 or more 50
Most preferred as the composition comprising less than 10,000 polyolefins is a composition comprising ultra high molecular weight polyethylene and high density polyethylene.

When used for a battery separator, it is preferable to add polypropylene to improve the meltdown temperature. As the type of polypropylene, a block copolymer, a random copolymer, or the like can be used in addition to the homopolymer. This block copolymer and random copolymer include α other than propylene.
-It can contain a copolymerization component with an olefin, and ethylene is preferred as the other α-olefin.

Further, in the method of the present invention, the above-mentioned low-density polyethylene can be used as a polyolefin having a shutdown function in order to improve the characteristics as a battery separator. Examples of the low-density polyethylene include branched low-density polyethylene (LDPE) and linear low-density polyethylene (LLDP).
E), ethylene
At least one or more polyolefins selected from the α-olefin copolymers can be added. Also,
Similarly to the above, in order to improve the characteristics as a battery separator application, as a polyolefin having a shutdown function, a weight average molecular weight of 1000 to 400
Zero low molecular weight polyethylene may be added. However,
If the addition amount is large, the film is likely to break when stretched. Therefore, the addition amount is preferably 20 parts by mass or less based on the entire thermoplastic resin.

The molecular weight distribution Mw / Mn of the polyolefin or polyolefin composition in the method of the present invention is not particularly limited, but is preferably from 5 to 300, more preferably from 10 to 100. When the molecular weight distribution Mw / Mn is less than 5, the amount of the high molecular weight component becomes too large, so that the melt extrusion becomes difficult.
When w / Mn exceeds 300, the low molecular weight component becomes too large, which leads to a decrease in strength.

As the plasticizer used in the method of the present invention, those having a melting point of 100 ° C. or less are preferable, but paraffin wax which is solid at ordinary temperature, higher alcohol such as stearyl alcohol and cetyl alcohol, n-liquid which is liquid at ordinary temperature is preferable. N-Alkanes such as decane, liquid paraffin, kerosene and the like can be suitably used. Preferably, in order to obtain a gel-like molded product having a stable solvent content, it is desirable to use a non-volatile solvent such as liquid paraffin.
Further, in addition to this, -OH group,-
A water-soluble linear polymer having a COOH group, a -CONH ₂ group, or the like, for example, polyethylene glycol, polypropylene glycol, polyacrylic acid, or polyvinyl alcohol may be used.

In the method of the present invention, the thermoplastic resin /
The mass ratio of the plasticizer is not particularly limited, but is 1/99 to 5
0/50, preferably 20/80 to 40/60. If the mass fraction of the thermoplastic resin is less than 1%, the swell or neck-in becomes large at the die exit when molding the gel-like molded product, and the moldability and self-supporting property of the gel-like molded product are reduced. . On the other hand, if it exceeds 50%, the moldability of the gel-like molded product will decrease.

In the method of the present invention, the above-mentioned thermoplastic resin and plasticizer are uniformly kneaded by a known single-screw or twin-screw extruder, and are melt-extruded to form a film or sheet-like gel-like molded product. The melt extrusion temperature varies depending on the resin used, but in the case of a polyolefin or a composition containing a polyolefin, 160 to 230 ° C, preferably 160 to 230 ° C.
220 ° C. The melt-extruded film or sheet-like gel-like molded product is cooled according to a conventional method, and then the plasticizer in the gel-like molded product is mixed with the extractant composition of the first invention or the second invention of the present invention. By performing the extraction treatment, the desired porous molded body can be obtained. Furthermore, in the method of the present invention, a stretching step may be provided between the step of extracting the plasticizer after the cooling, and a heat treatment or the like may be performed after the extraction processing. Further, it is desirable that the extraction treatment is performed before and / or after stretching the gel-like molded body, preferably after stretching. The stretching step is preferably performed at a temperature within the range of the melting point + 10 ° C. or lower, more preferably within the range of the crystal dispersion temperature to the melting point. Here, the crystal dispersion temperature refers to the temperature determined by measuring the temperature characteristics of dynamic viscoelasticity based on ASDM D 4065, and the melting point refers to the temperature determined by differential scanning calorimetry (DSC) based on JIS K 7121-1987. Refers to the required value. In the heat treatment, any of heat shrinkage, heat fixing, and heat stretching may be used.

In the method of the present invention, the above-mentioned extraction treatment is carried out by melt-kneading a mixture of a thermoplastic resin and a plasticizer, and then extruding the film or sheet-like gel-like molded product into the above-mentioned components (A) to (C). Or an extractant composition comprising the above components (D) and (E),
Immerse for 10 seconds or more, preferably for about 30 seconds to 30 minutes. In addition, the immersion temperature at that time needs to be lower than the melting point of the thermoplastic resin and higher than the melting point of the plasticizer. In particular,
The reaction is carried out at 0 to 100 ° C, preferably 30 to 80 ° C. At this time, if mechanical vibration such as ultrasonic waves or stirring is applied, the removal efficiency can be further improved. Then
The immersion liquid is changed to water or a mixture of water and a lower alcohol-based solvent, and the same immersion operation is repeated to reduce the remaining amount of the plasticizer to a target amount, followed by drying. The drying method is a usual method of hot air drying or reduced pressure drying at a constant temperature as required. The porous molded article of the thermoplastic resin thus obtained has a porosity of 30 to 95% and an air permeability of 20 to 15%.
00 sec / 100cc, piercing strength 4900mN / 25μm
As described above, it is particularly suitable as a battery separator.

The extractant composition of the first invention or the second invention constituted as described above can be used in the same or similar manner as these organic solvents without using a conventionally used air-permeable organic solvent. It has the same or higher extractability to plasticizers, has extremely low flammability, has excellent usability, and has excellent stability over time. Further, in the method of the present invention configured as described above, by using the extractant composition of the first or second invention, it is possible to efficiently obtain a porous molded body having excellent physical properties, In particular, an excellent manufacturing method for a battery separator can be provided. Further, the battery separator produced by the method of the present invention has effective gas permeability, porosity, and mechanical strength required for the separator, and sufficiently satisfies battery characteristics.

[0029]

Next, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not particularly limited to the following examples.

[Examples 1 to 11 and Comparative Examples 1 to 9] (Preparation of Extractant Composition) The extractant compositions having the composition shown in Tables 1 and 2 below were used. The stability over time of each extractant composition was evaluated by the following evaluation method. The results are shown in Tables 1 and 2 below.

(Production of Thermoplastic Resin Porous Molded Article) (Examples 1 to 11) 20% of ultra high molecular weight polyethylene having a mass average molecular weight of 2.0 × 10 ⁸ and high density polyethylene of 3.5 × 10 ⁵ 80%, molecular weight distribution Mw / M
Polyethylene composition with n = 16.8 (melting point 135)
0.37 parts by mass of tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) -propionate] methane as an antioxidant was added per 100 parts by mass of (C, crystal dispersion temperature 90 ° C). A polyethylene composition was obtained. 30 parts by mass of the obtained polyethylene composition was charged into a twin-screw extruder (58 mmφ, L / D = 42, strong kneading type), and 70 parts by mass of liquid paraffin was supplied from a side feeder of the twin-screw extruder, and 200 ° C, 20
The mixture was melt-kneaded at 0 rpm to prepare a polyethylene solution in an extruder. Then, the T installed at the tip of the extruder
The stretched film was extruded from the die so as to have a thickness of about 60 μm, and was taken up by a cooling roll adjusted to 50 ° C. to prepare a gel-like sheet. Subsequently, the gel-like sheet of
Using a batch stretching machine, simultaneous biaxial stretching was performed at 115 ° C. to 5 × 5 to obtain a stretched film. The obtained stretched film is 30 cm ×
It was fixed on a 30 cm stainless steel fixing frame and added to 3 L of the extractant composition having the composition shown in Tables 1 and 2 below at 60 ° C. while stirring with 40 kHz ultrasonic wave from the lower part of the film.
Soak for minutes. Next, the immersion liquid was changed to ion-exchanged water and rinsed twice under the same conditions.
Warm air drying was performed for minutes. Then, at 120 ° C for 10 minutes,
A heat-setting treatment was performed to obtain a porous molded body of polyethylene.

Comparative Examples 1 to 3 and 5 to 9 Using a biaxially stretched film produced in the same manner as in the above examples, the same treatment as in the examples was performed to obtain a porous molded article of polyethylene. [Comparative Example 4] A biaxially stretched film obtained by the same method as in the above example was fixed to a fixed frame in the same manner as in the example, immersed in 3 L of methylene chloride for 5 minutes, and liquid paraffin was extracted and removed. And dried with warm air at 50 ° C. for 20 minutes. afterwards,
A heat-setting treatment was performed at 120 ° C. for 10 minutes to obtain a porous molded body of polyethylene.

The residual amount of liquid paraffin, the porosity, and the air permeability of each of the porous molded articles of polyethylene thus prepared were measured by the following test methods. The results are shown in Tables 1 and 2 below.

[Evaluation Method of Stability of Extractant Composition over Time]
Each of the obtained extractant compositions was placed in a 100-ml transparent bottle, allowed to stand in a constant temperature room at 25 ° C. for one week, and the liquid stability over time was visually determined according to the following evaluation criteria. Evaluation criteria: ○: uniform transparent liquid ×: liquid with high viscosity, or remarkable two-layer separation

[Method of Measuring Liquid Paraffin Remaining Amount] Each of the obtained porous molded bodies was cut into about 10 cm × 10 cm, each test piece was weighed, and the remaining plasticizer was extracted with carbon tetrachloride. Then, carbon tetrachloride was removed from this extract under reduced pressure, the amount of liquid paraffin extracted was measured by mass, and this mass was divided by the mass of the test piece before carbon tetrachloride extraction to calculate a ratio (%).

[Method of measuring porosity] The porosity was measured by a mass method. The film thickness required for the calculation was measured using a stylus-type film thickness meter Mitutoyolitematic manufactured by Mitutoyo Corporation.

[Method of measuring air permeability] JIS P 811
It was measured according to 7-1980.

[0038]

[Table 1]

[0039]

[Table 2]

As is clear from the results of Tables 1 and 2, the extractant compositions of Examples 1 to 11 which fall within the scope of the present invention are compared with Comparative Examples 1 to 7 which fall outside the scope of the present invention. It was found to be excellent in liquid stability, small in residual amount of liquid paraffin, and excellent in porosity and air permeability.

[0041]

According to the present invention, according to the present invention,
Without using air-permeable organic solvents, etc., it has the same or higher extractability to plasticizers as those organic solvents, etc., and also has extremely low flammability, excellent usability, and stability over time. The present invention provides an extractant composition for a thermoplastic molded article having excellent heat resistance. Further, according to the method of the present invention, by using the extractant composition of the present invention, a method for producing a porous molded article having excellent physical properties, particularly a thermoplastic resin porous molded article suitable for a battery separator. Is provided. In particular, if the thermoplastic resin porous molded article obtained by the method of the present invention is used for a battery separator, it has the effective gas permeability and porosity required for the separator, and mechanical strength, and sufficiently satisfies the battery characteristics. It will be.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Satoshi Fukasawa 1-3-7 Honjo, Sumida-ku, Tokyo F-term in Lion Corporation (reference) 4F074 AA17 AA18 AA19 AA20 AA22 AA23 AA24A AA24B AA65 AA71 AD01 AD04 CB03 CB16 CB28 CB34 CB45 CC02X CC22X CC42 DA49 4F212 AA04 AA11 AB07 AG20 AH03 UA15 UH18

Claims (4)

[Claims] 1. An extractant composition for a porous molded article of a thermoplastic resin, which comprises the following (A) to (C). (A); 5 to 50% by mass of an anionic surfactant (B); 5 to 90% by mass of an alkylene oxide derivative represented by the following formula (I) (C); water 5 to 45% by mass 2. An extractant composition for a porous molded article of a thermoplastic resin, comprising the following (D) and (E). (D); 65 to 95% by mass of a nonionic surfactant represented by the following formula (II): (E); water 5 to 35% by mass 3. The extractant composition according to claim 1, wherein a gel-like molded product obtained by melt-kneading a thermoplastic resin and a plasticizer is heated to a melting point of the plasticizer or higher, or A process for producing a porous molded article of a thermoplastic resin, which comprises removing the plasticizer from the molded article by treating the composition with a water diluent of each composition to obtain a porous molded article. 4. The method for producing a porous thermoplastic resin article according to claim 3, wherein the gel-like molded article is stretched before and / or after stretching.
Alternatively, a method for producing a thermoplastic resin porous molded body, comprising removing a residual plasticizer after stretching.