JP3443934B2 - Stretched porous polypropylene resin and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a β-crystal polypropylene stretched product and a porous polypropylene resin stretched product produced by the method.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a polypropylene-based porous material, (1) a method of obtaining a porous film by adding an inorganic material or an incompatible resin to polypropylene, and then extruding and stretching 50-5016561
No.) or (2) polypropylene containing an inorganic or organic liquid, followed by extraction with a solvent or alkali, stretching, etc. to obtain a porous film (JP-A-58-590).
No. 72) is known.

However, the above method (1) has drawbacks such as precipitation of inorganic substances and reduction in elongation at break, and the above method (2) requires a complicated process such as extraction for a long time. It has the drawback of

Further, (3) a method of producing a porous film by utilizing a crystal modification (β crystal) peculiar to polypropylene is also known (Japanese Patent Publication No. 55-40411), but under practical conditions. Under the present circumstances, it is difficult to generate a sufficient amount of β crystal, and a porous film having a satisfactory porosity has not been obtained.

As a method for producing β crystals in polypropylene, a method of crystallizing molten polypropylene under a temperature gradient or a method of adding and mixing a small amount of β crystal nucleating agent (γ-quinacridone) (POLYMER LETTERS, 6, 539-546, (1968)) etc. have been proposed. However, the former takes a long time,
Moreover, it has a drawback that only a small amount of sample can be obtained. In addition, the latter method has a drawback that special equipment and operation are required for mixing with polypropylene. Further, in order to generate a certain amount or more of β crystal in the unstretched product, it is necessary to crystallize at a high temperature, which requires a long time for molding, which is impractical, and the product is colored red. There is a problem.

The present inventors have previously proposed various new β crystal nucleating agents as means for solving such problems (Japanese Patent Application No. 4-135892 and Japanese Patent Application No. 4-283689).
No. 4-324807).

[0007]

The present invention is based on the above (3).
It is an object of the present invention to improve the method according to (1) and to provide a novel and useful method for producing a polypropylene-based porous material having satisfactory properties under practical conditions.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that
It was found that the intended purpose can be achieved only by crystallizing a melt obtained by compounding a predetermined amount of an amide compound having a specific structure as a β crystal nucleating agent at a predetermined temperature and then stretching at a predetermined temperature. The present invention has been completed based on such findings.

That is, the method for producing a β crystal type polypropylene porous stretched product according to the present invention comprises a polypropylene resin 10
0.0001 to 5 parts by weight of one or two or more amide compounds selected from the group consisting of compounds represented by the general formula (1) or the general formula (2) is contained with respect to 0 part by weight. Melt the polypropylene-based resin composition to 15 to 14
It is characterized in that it is crystallized at 0 ° C. to obtain a solidified product containing β crystal, and then the solidified product is stretched at a temperature of 20 ° C. or higher to a temperature not higher than the melting point of β crystal in the solidified product.

R ² —NHCO—R ¹ —CONH—R ³ (1) [wherein, R ¹ is a saturated or unsaturated aliphatic dicarboxylic acid residue having 1 to 24 carbon atoms, saturated having 4 to 28 carbon atoms] Or an unsaturated alicyclic dicarboxylic acid residue or carbon number 6 to 28
Represents an aromatic dicarboxylic acid residue of. R ² and R ³ are the same or different and each represents a cycloalkyl group having 3 to 18 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, a general formula (a), a general formula (b), a general formula (c) or a general formula. It represents a group represented by the formula (d). ]

[0011] In the formula, R ⁴ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkenyl group having 2 to 12 carbon atoms, or a cycloalkyl having 6 to 10 carbon atoms. Represents an alkyl group or a phenyl group. R ⁵ has 1 carbon
To 12 straight chain or branched chain alkyl groups or 2 carbon atoms
Represents a straight-chain or branched-chain alkenyl group of ~ 12. R
⁶ and R ⁷ are the same or different and each represents a linear or branched alkylene group having 1 to 4 carbon atoms. ]

R ⁹ —CONH—R ⁸ —NHCO—R ¹⁰ (2) [wherein, R ⁸ is a saturated or unsaturated aliphatic diamine residue having 1 to 24 carbon atoms, and an alicyclic ring having 4 to 28 carbon atoms] It represents a group diamine residue, a heterocyclic diamine residue having 6 to 12 carbon atoms, or an aromatic diamine residue having 6 to 28 carbon atoms. R ⁹ and R ¹⁰ are the same or different and each represent a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, a general formula (e), a general formula (f), a general formula (g) or a general formula. Formula (h)
Represents a group represented by. ]

[0013] [In the formula, R ¹¹ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkenyl group having 2 to 12 carbon atoms, or an alkyl group having 6 to 10 carbon atoms. Represents a cycloalkyl group or a phenyl group, and R ¹² has 1 to 12 carbon atoms
Linear or branched alkyl group having 2 to 12 carbon atoms
Represents an alkenyl group, a cycloalkyl group having 6 to 10 carbon atoms or a phenyl group. R ¹³ and R ¹⁴ represent a linear or branched alkylene group having 1 to 4 carbon atoms. ]

[0014]

The amide compound represented by the general formula (1) is
Amidating the aliphatic, alicyclic or aromatic dicarboxylic acid represented by the general formula (1a) and one or two alicyclic or aromatic monoamines represented by the general formula (1b). Therefore, it can be easily prepared.

HOOC-R ¹⁸ —COOH (1a) [In the formula, R ¹⁸ has the same meaning as R ¹ described above. ]

R ¹⁹ —NH ₂ (1b) [In the formula, R ¹⁹ has the same meaning as R ² and R ³ described above. ]

The aliphatic dicarboxylic acid has 3 to 10 carbon atoms.
26, preferably 3 to 14 saturated or unsaturated aliphatic dicarboxylic acids and the like, more specifically, malonic acid,
Diphenylmalonic acid, succinic acid, phenylsuccinic acid, diphenylsuccinic acid, glutaric acid, 3,3-dimethylglutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1 , 1
Examples include 4-tetradecanedioic acid and 1,18-octadecanedioic acid.

The alicyclic dicarboxylic acid has 6 to 6 carbon atoms.
30, preferably 8 to 12 alicyclic dicarboxylic acids and the like, and more specifically, 1,2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,
4-cyclohexanediacetic acid etc. are illustrated.

The aromatic dicarboxylic acid has 8 to 8 carbon atoms.
Examples of the aromatic dicarboxylic acid of 30 and preferably 8 to 22 include p-phenylenediacetic acid and 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 Acid, 2,7-naphthalenedicarboxylic acid, diphenic 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'-sulfonyldibenzo Acid, 3,3'-
Oxydibenzoic 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 Acid, 4,4'-isophthaloyldibenzoic acid, 4,
Aromatic dibasic acids such as 4′-terephthaloyldibenzoic acid and dithiosalicylic acid are exemplified.

The alicyclic monoamine has 3 to 1 carbon atoms.
Examples thereof include cycloalkylamines having 8 carbon atoms, cycloalkenylamines having 3 to 12 carbon atoms, compounds represented by the general formula (4) or the general formula (5), and more specifically, 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-amylcyclohexylamine, 4-isoamylcyclohexylamine, 4-sec-
Amylcyclohexylamine, 4-tert-amylcyclohexylamine, 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-cyclohexylpropylamine, β
-Cyclohexylpropylamine, γ-cyclohexylpropylamine and the like are exemplified.

[0022] [In the formula, R ²⁰ has the same meaning as the above R ⁵ . ]

[0023] [In the formula, R ²¹ has the same meaning as R ⁷ described above. ]

The aromatic monoamine is represented by the general formula (6)
Or the compound etc. which are represented by General formula (7) are illustrated, More specifically, 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-
Examples include aminodiphenyl, p-aminodiphenyl, p-aminostyrene, benzylamine, α-phenylethylamine, β-phenylethylamine, α-phenylpropylamine, β-phenylpropylamine, γ-phenylpropylamine and the like.

[0025] [In the formula, R ²² has the same meaning as R ⁴ described above. ]

[0026] [In the formula, R ²³ has the same meaning as R ⁶ described above. ]

Among the amide compounds represented by the general formula (1), particularly preferable compounds are N, N'-diphenylhexanediamide, N, N'-dicyclohexylterephthalamide or N, N'-dicyclohexyl-2. ，
6-naphthalene dicarboxamide and the like can be mentioned.

The amide compound represented by the general formula (2) includes an aliphatic, alicyclic or aromatic diamine represented by the general formula (2a) and an alicyclic compound represented by the general formula (2b). It can be easily prepared by amidating one or two aromatic monocarboxylic acids according to a conventional method.

H ₂ N—R ²⁴ —NH ₂ (2a) [In the formula, R ²⁴ has the same meaning as the above R ⁸ . ]

R ²⁵ —COOH (2b) [In the formula, R ²⁵ has the same meaning as the above R ⁹ and R ¹⁰ . ]

The aliphatic diamine has 1 to 2 carbon atoms.
4, preferably 1 to 12 aliphatic diamines are exemplified, and more specifically, 1,2-diaminoethane, 1,2
-Diaminopropane, 1,3-diaminopropane, 1,
4-diaminobutane, 1,3-diaminopentane, 1,
5-diaminopentane, 1,6-diaminohexane,
Examples include 1,8-diaminooctane, 1,10-diaminodecane, and 1,11-diaminoundecane.

The alicyclic diamine has 4 to 2 carbon atoms.
8, preferably 6 to 15 alicyclic diamines are exemplified, and more specifically, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, 4,4′-diaminodicyclohexyl, 4,4′- Diamino-3,3 '
-Dimethyldicyclohexyl, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'-
Examples include dimethyldicyclohexylmethane, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, isophoronediamine, menthenediamine, and the like.

The heterocyclic diamine is a 5- or 6-membered ring containing one or two nitrogen atoms or sulfur atoms in its ring structure, and examples thereof include heterocyclic diamines having 4 to 14 carbon atoms. More specifically, 2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, o-tolidine sulfone and the like are exemplified.

The aromatic diamine has 6 to 2 carbon atoms.
8, preferably 6 to 15 aromatic diamines are exemplified, and more specifically, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,3-
Diaminotoluene, 2,4-diaminotoluene, 2,6
-Diaminotoluene, 3,4-diaminotoluene, 4,
6-dimethyl-m-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, 4,5-dimethyl-o
-Phenylenediamine, o-xylylenediamine, m-
Xylylenediamine, p-xylylenediamine, 2,4
-Diaminomesitylene, 1,5-diaminonaphthalene,
1,8-diaminonaphthalene, 2,3-diaminonaphthalene, 2,7-diaminonaphthalene, 9,10-diaminophenanthrene, 3,3 ′, 5,5′-tetramethylbenzidine, 3,3′-dimethyl -4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,4'-diaminodiphenylmethane,
3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-methylenedi-o-toluidine, 4,4'-methylenedi-2,6-xylidine, 4,4'-methylenedi-2,6 -Diethylaniline, 4,4'-diamino-1,2-diphenylethane,
4,4'-diamino-2,2'-dimethylbibenzyl,
4,4'-diaminostilbene, 3,4'-diamino-
2,2-diphenylpropane, 4,4'-diamino-
2,2-diphenylpropane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-thiodianiline, 2,2'-dithiodianiline, 4,4'-dithiodianiline, 3, 3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone,
4,4'-diaminobenzophenone, 4,4'-diaminobenzanilide, 2,7-diaminofluorene, 3,
7-diamino-2-methoxyfluorene, bis-p-aminophenylaniline, 1,3-bis (4-aminophenylpropyl) benzene, 1,4-bis (4-aminophenylpropyl) benzene, 1,3-bis (4-Aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ether, bis Examples include [4- (4-aminophenoxy) phenyl] sulfone and 9,9-bis (4-aminophenyl) fluorene.

The alicyclic monocarboxylic acid has 4 carbon atoms.
To cycloalkanecarboxylic acid having 13 to 13 carbon atoms, cycloalkenecarboxylic acid having 4 to 13 carbon atoms, compounds represented by the general formula (8) or the general formula (9), and the like, more specifically, cyclopropanecarboxylic acid. , Cyclobutanecarboxylic acid, cyclopentanecarboxylic acid, 1-methylcyclopentanecarboxylic acid, 2-methylcyclopentanecarboxylic acid, 3-methylcyclopentanecarboxylic acid, 1-phenylcyclopentanecarboxylic 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-phenylcyclohexanecarboxylic acid, cyclohexenecarboxylic acid, 4-butylcyclohexenecarboxylic acid, cycloheptanecarboxylic acid, 1-cycloheptenecarboxylic acid Acid, 1-methylcycloheptanecarboxylic acid, 4-methylcycloheptanecarboxylic acid, cyclohexylacetic acid and the like are exemplified.

[0036]

[0037] [In the formula, R ²⁷ has the same meaning as R ¹⁴ described above. ]

Examples of the aromatic monocarboxylic acid include compounds represented by the general formula (10) or the general formula (11), and more specifically, 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-pentylbenzoic acid, p-hexylbenzoic acid, o-phenylbenzoic acid, p-phenylbenzoic acid , P-cyclohexylbenzoic acid, phenylacetic acid, phenylpropionic acid, phenylbutyric acid and the like.

[0039] [In the formula, R ²⁸ has the same meaning as R ¹¹ described above. ]

[0040]

Among the diamide compounds obtained from the above diamine and monocarboxylic acid, more preferable compounds are N, N'-dicyclohexanecarbonyl-p-phenylenediamine and N, N'-dibenzoyl-1,5-diaminonaphthalene. , N, N'-dibenzoyl-1,4-
Examples include diaminocyclohexane, N, N′-dicyclohexanecarbonyl-1,4-diaminocyclohexane and the like.

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

Among the amide compounds represented by the general formula (1) and the general formula (2) , the amide compound represented by the general formula (1) is particularly effective.

The polypropylene resin according to the present invention is a polymer containing propylene as a main constituent component,
Specifically, a propylene homopolymer, a copolymer of propylene as a main component with ethylene and / or one or more 1-alkenes (including both random and block), and a propylene / ethylene multi-component copolymer (5- Examples include ethylidene-2-norbornene, 5-methylene-2-norbornene or 1,4-hexadiene), propylene-styrene copolymer, and the like. Further, a blend polymer of the above polypropylene and a small amount of a thermoplastic resin, for example, high density polyethylene, polybutene-1, poly-4-methylpentene-1, etc. is exemplified.

Melt flow rate of the polypropylene resin (hereinafter abbreviated as "MFR". JIS K 6758-1981)
Is determined appropriately according to the molding method to be applied, and is usually in the range of about 0.1 to 100 g / 10 minutes, preferably 0.5 to 50 g / 10 minutes. It is preferable in terms of physical properties and processability.

The applied amount of the amide compound according to the present invention is
0.000 to 100 parts by weight of polypropylene resin
1 to 5 parts by weight, more preferably 0.001 to 1 part by weight. If the amount is less than 0.0001 parts by weight, β crystals are less likely to be formed, and even if the amount is more than 5 parts by weight, no significant difference in effect is observed, and the elongation at break and strength at break decrease. There are drawbacks.

The amide compound may be added at the time of preparing the polypropylene resin, or may be added to and mixed with a resin prepared separately.

The melting temperature of the polypropylene resin composition is usually about 190 to 300 ° C, more preferably about 200 to 280 ° C.

The crystallization temperature (cooling temperature) of the resin melt in the method of the present invention is 15 to 140 ° C., preferably 20 to 120 ° C., more preferably 70 to 120 ° C. is recommended. Generally, β in the unstretched product obtained at this time
The crystal content ratio (K value) is about 0.5 to 1.0, which is a practical property.

The unstretched polypropylene (solidified product) containing β crystals prepared by the above method is stretched according to a conventional method at a temperature of 20 ° C. or higher and a temperature not higher than the melting point of β crystals in the unstretched product. The melting point of the β crystal in the unstretched material can be easily found by DSC, but it varies depending on the type of raw material resin and is as high as about 150 ° C. Furthermore, in order to obtain a higher porosity, it is more preferable to stretch at a temperature lower by 10 ° C. or more than the melting point of β crystal in the unstretched material. From the standpoint of workability of stretching, it is recommended that the stretching temperature be 70 ° C or higher, preferably 90 ° C or higher.

That is, the stretched product having a sufficient porosity (for example, 10% or more, preferably about 20 to 80%) according to the present invention is crystallized in the above temperature range and then stretched in the above predetermined temperature range. It can be obtained only by doing.

The stretching method may be either uniaxial stretching and simultaneous or sequential biaxial stretching.

Both uniaxial stretching and simultaneous or sequential biaxial stretching can be carried out by a commonly used method. Specifically, in the case of biaxial stretching, the degree of stretching is not particularly limited, but is, for example, about 1.2 to 5.0 times in the longitudinal direction and about 1.2 to 5.0 times in the lateral direction. It is preferable to stretch. Also in the case of uniaxial stretching, the degree of stretching is not particularly limited, but it is preferable to stretch in the longitudinal direction by, for example, about 1.5 to 6.0 times.

Further, as the pressure condition at the time of processing, not only normal pressure but also any condition under pressure or under pressure can be appropriately adopted.

Furthermore, the polyolefin resin stretched product according to the present invention may be used in combination with a conventionally known modifier for polyolefin as long as it does not impair the effects of the present invention, depending on the purpose of use and its application. .

As such a modifier for polyolefin,
Examples thereof include various additives described in "Positive List of Additives" (October 1990) edited by the Council for Hygiene of Polyolefins, and more specifically, stabilizers (metal compounds, epoxy compounds, nitrogen). Compounds, phosphorus compounds, sulfur compounds, etc.), ultraviolet absorbers (benzophenone compounds, benzotriazole compounds, etc.), antioxidants (phenolic compounds, phosphite compounds, sulfur compounds, etc.), surfactants, Lubricants (aliphatic hydrocarbons such as paraffin and wax, higher fatty acids having 8 to 22 carbon atoms, higher fatty acid metals having 8 to 22 carbon atoms (Al, Ca, M
g, Zn) salt, fatty acid having 8 to 18 carbon atoms, 8 to 2 carbon atoms
2 aliphatic alcohols, polyglycols, 4 to 2 carbon atoms
Esters of 2 higher fatty acids and aliphatic monohydric alcohols having 4 to 18 carbon atoms, higher fatty acid amides having 8 to 22 carbon atoms, silicone oil, rosin derivatives, etc., fillers (talc, hydrotalcite, mica, zeolite) , Perlite, diatomaceous earth, calcium carbonate, glass fiber, etc.), foaming agents, foaming aids, polymer additives, plasticizers, crosslinking agents,
Crosslinking accelerator, antistatic agent, neutralizing agent, antiblocking agent, antifogging agent, polymer alloy component (rubber such as block SBR or random SBR and their hydrides, polystyrene, etc.), flame retardant, dispersant, organic Alternatively, various additives such as inorganic pigments or dyes and processing aids are exemplified.

The polypropylene-based resin stretched product thus obtained forms a porous opaque film having excellent whiteness, hiding power, printability and writability, or a porous film having a large number of penetrating fine pores. The opaque film is a printing paper,
Widely used as a material for tracing paper and food packaging films. Further, the porous membrane is a film,
Filters and separation membranes in the form of hollow fibers used for moisture and waterproof applications, air purification, water treatment, etc., as well as plasma separation membranes, medical materials such as artificial lungs, batteries or battery separators for electrolysis, etc. Widely used in such fields.

[0064]

EXAMPLES The present invention will be described in detail below with reference to Examples and Comparative Examples. The β crystal content and the porosity were determined by the following methods.

[Measurement of β Crystal Content] (1) X-ray Method: The polypropylene raw film was subjected to X-ray diffraction, and the K value was calculated from the following formula. K value = H (β ₁ ) / [H (β ₁ ) + H (α ₁ ) + H (α ₂ )
+ H (α ₃ )] H (β ₁ ): β crystal (300) plane diffraction intensity (height) H (α ₁ ): α crystal (110) plane diffraction intensity (height) H (α ₂ ): Diffraction intensity (height) of α crystal (040) plane H (α ₃ ): Diffraction intensity (height) of α crystal (130) plane

(2) DSC method: Approximately 5 mg of polypropylene original film was set in a DSC sample holder and heated at 20 ° C./min in a nitrogen atmosphere to obtain the DSC obtained at this time.
From the melting peak area of α-type crystal and β-crystal of the thermogram, β
The crystal content (area%, DSC%) was determined.

[Porosity] A unit volume of the stretched film was impregnated with salad oil (ρ = 0.925 g / cm ³ ) and determined by the following formula. α = (Vo / Vf) × 100 α: Porosity (%) Vo: Volume of impregnated salad oil Vf: Apparent volume of film

Examples 1 to 7 With respect to 100 parts by weight of propylene homopolymer powder having an MFR of 14 g / 10 min (hereinafter abbreviated as "PP (1)"), N, N'-dicyclohexyl was used as a β crystal nucleating agent. −
0.1 part by weight of 2,6-naphthalene dicarboxamide (hereinafter abbreviated as "main nucleating agent 1") is mixed with a Henschel mixer and pelletized at 240 ° C. Then, it was extruded into a sheet at a resin temperature of 240 ° C. using a T-die extruder, and cooled and solidified by a chill roll maintained at a predetermined temperature to obtain a polypropylene raw film having a thickness of 200 μm. Β crystal content of the obtained unstretched film (K value and D
SC%) is shown in Table 1.

Then, this film was uniaxially or biaxially stretched at a predetermined temperature shown in Table 1 to obtain a white opaque stretched film. The stretching temperature is below the melting point of the β crystal in the unstretched material (from the DSC results, PP
The melting point of β crystal in (1) was 152 ° C). When this film was impregnated with salad oil, all became translucent films, and it was confirmed that they were porous films having excellent continuous through-hole properties. The porosity (%) of the stretched film obtained from the thickness of the stretched film and the oil impregnation amount is shown in Table 1.
Indicates.

Example 8 A stretched film was prepared in the same manner as in Example 3 except that propylene homopolymer powder (hereinafter abbreviated as "PP (2)") having an MFR of 4.3 g / 10 min was used. The obtained stretched film was a porous film having excellent continuous through-hole properties. Β crystal content of unstretched film (K value and DS
C%) and the thickness and porosity of the stretched film are shown in Table 1. The melting point of the β crystal in PP (2) was 147 ° C.

Example 9 A stretched film was prepared in the same manner as in Example 3 except that propylene homopolymer powder (hereinafter abbreviated as "PP (3)") having an MFR of 1.4 g / 10 min was used. The obtained stretched film was a porous film having excellent continuous through-hole properties. Β crystal content of unstretched film (K value and DS
C%) and the thickness and porosity of the stretched film are shown in Table 1. The melting point of the β crystal in PP (3) was 148 ° C.

Example 10 A film was prepared in the same manner as in Example 6 except that PP (3) was used, and then this film was uniaxially stretched at 90 ° C. to obtain a stretched film. The obtained stretched film was a porous film having excellent continuous through-hole properties. Table 1 shows the β crystal content (K value and DSC%) of the unstretched film, and the thickness and porosity of the stretched film.

Examples 11 to 12 Stretched films were prepared in the same manner as in Example 1 except that the addition amount of the present nucleating agent 1 was changed. The obtained stretched film was a porous film having excellent continuous through-hole properties. Table 1 shows the β crystal content (K value and DSC%) of the unstretched film, and the thickness and porosity of the stretched film.

Example 13 A film was prepared in the same manner as in Example 1 except that N, N'-dicyclohexylterephthalamide (hereinafter abbreviated as "main nucleating agent 2") was applied as the β crystal nucleating agent. Table 1 shows the β crystal content (K value and DSC%) of the obtained unstretched film, and the thickness and porosity of the stretched film.

Example 14 A film was prepared in the same manner as in Example 1 except that N, N'-diphenylhexanediamide (hereinafter abbreviated as "main nucleating agent 3") was applied as the β crystal nucleating agent. Table 1 shows the β crystal content (K value and DSC%) of the obtained unstretched film, and the thickness and porosity of the stretched film.

Example 15 A film was prepared in the same manner as in Example 1 except that N, N'-dicyclohexanecarbonyl-p-phenylenediamine (hereinafter abbreviated as "main nucleating agent 4") was used as the β crystal nucleating agent. Was prepared. Table 1 shows the β crystal content (K value and DSC%) of the obtained unstretched film, and the thickness and porosity of the stretched film.

Example 16 N, N′-dibenzoyl-1,4-diaminocyclohexane as a β crystal nucleating agent (hereinafter abbreviated as “main nucleating agent 5”)
A film was prepared in the same manner as in Example 1 except that Β crystal content of the obtained unstretched film (K value and D
SC%) and the thickness and porosity of the stretched film are shown in Table 1.

[0078]

Comparative Example 1 A film was prepared in the same manner as in Example 1 except that it was cooled and solidified by a chill roll maintained at 10 ° C. The β crystal content (K value and DSC%) of the obtained unstretched film was first
Shown in the table. Next, this film was uniaxially stretched at 130 ° C. to obtain a stretched film. The obtained film was translucent and the porosity showed only a small value as shown in Table 1.

Comparative Example 2 A film was prepared in the same manner as in Example 1 except that the film was cooled and solidified by a chill roll maintained at 20 ° C. The β crystal content (K value and DSC%) of the obtained unstretched film was first
Shown in the table. Then, this film was uniaxially stretched at 155 ° C. to obtain a stretched film. The obtained film was almost transparent and no impregnation with salad oil was observed.

Comparative Example 3 An unstretched film was prepared in the same manner as in Example 1 except that the β crystal nucleating agent was not used. Table 1 shows the β crystal content (K value and DSC%) of the obtained unstretched film. Next, this film was biaxially stretched at 125 ° C. to obtain a stretched film. The obtained film was almost transparent and no impregnation with salad oil was observed.

[Table 1]

[0082]

EFFECTS OF THE INVENTION By applying the amide compound according to the present invention as a β crystal nucleating agent, a polypropylene-based porous stretched product can be easily industrially produced under practical conditions. The stretched product is a useful material for printing paper, filtration membranes, separation membranes and the like.

Continuation of front page (56) Reference JP-A-7-118429 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08J 9/00

Claims (5)

(57) [Claims] 1. 0.0001 of one or two or more amide compounds selected from the group consisting of compounds represented by the general formula (1) or (2) per 100 parts by weight of a polypropylene resin. ˜5 parts by weight of the polypropylene resin composition melt is crystallized at 15 to 140 ° C. to obtain a solidified product containing β crystals, and the solidified product is then heated to 20 ° C.
A method for producing a stretched porous polypropylene-based resin, which comprises stretching at a temperature not higher than the melting point of β crystal in the solidified product. ^{R 2 -NHCO-R 1 -CONH-} R 3 (1) [ wherein, ^{R 1} represents an aliphatic dicarboxylic acid residue of a saturated or unsaturated 1 to 24 carbon atoms, saturated or unsaturated 4 to 28 carbon atoms Alicyclic dicarboxylic acid residue of 6 to 28 carbon atoms
Represents an aromatic dicarboxylic acid residue of. R ² and R ³ are the same or different and each represents a cycloalkyl group having 3 to 18 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, a general formula (a), a general formula (b), a general formula (c) or a general formula. It represents a group represented by the formula (d). ] [In the formula, R ⁴ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a linear or branched alkenyl group having 2 to 12 carbon atoms, and 6 to 10 carbon atoms. Represents a cycloalkyl group or a phenyl group. R ⁵ has 1 carbon
To 12 straight chain or branched chain alkyl groups or 2 carbon atoms
Represents a straight-chain or branched-chain alkenyl group of ~ 12. R
⁶ and R ⁷ are the same or different and each represents a linear or branched alkylene group having 1 to 4 carbon atoms. ^{] R 9 -CONH-R 8 -NHCO} -R 10 (2) [ wherein, ^{R 8} is an aliphatic diamine residue of a saturated or unsaturated 1 to 24 carbon atoms, alicyclic diamines of 4 to 28 carbon atoms It represents a residue, a heterocyclic diamine residue having 6 to 12 carbon atoms or an aromatic diamine residue having 6 to 28 carbon atoms. R ⁹ and R ¹⁰
Are the same or different, and are a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, a general formula (e), a general formula (f), a general formula (g) or a general formula (h).
Represents a group represented by. ] [In the formula, R ¹¹ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkenyl group having 2 to 12 carbon atoms, or an alkyl group having 6 to 10 carbon atoms. Represents a cycloalkyl group or a phenyl group, R ¹² has 1 to 1 carbon atoms
12 straight-chain or branched-chain alkyl groups having 2 to 2 carbon atoms
It represents a 12 alkenyl group, a cycloalkyl group having 6 to 10 carbon atoms, or a phenyl group. R ¹³ and R ^{14 each} have 1 to C carbon atoms.
4 represents a linear or branched alkylene group. ] 2. The method for producing a stretched porous polypropylene resin product according to claim 1, wherein the amide compound is a compound represented by the general formula (1). 3. The amide compound is N, N′-diphenylhexanediamide, N, N′-dicyclohexylterephthalamide, N, N′-dicyclohexyl-2,6-
Naphthalene dicarboxamide, N, N'-dicyclohexanecarbonyl-p-phenylenediamine, N, N '
-Dibenzoyl-1,5-diaminonaphthalene, N,
N'-dibenzoyl-1,4-diaminocyclohexane
Or N, N'-dicyclohexanecarbonyl-1,4-
The method for producing a polypropylene-based resin stretched product according to claim 1, which is one kind or two or more kinds of compounds selected from the group consisting of diaminocyclohexane . 4. The method for producing a porous polypropylene-based resin stretched product according to claim 1, wherein the stretching temperature is 70 to 150 ° C. 5. A porous polypropylene-based resin stretched product produced by the method according to any one of claims 1 to 4.