JPH08283542A - Stretched resin film - Google Patents

Abstract

PURPOSE: To obtain a translucent or opaque stretched resin film which is suitable for synthetic paper and is excellent in heat resistance. CONSTITUTION: This stretched resin film having a void content of 5-50vol.% and an opacity of 35-100% is obtd. from a resin compsn. comprising 100 pts.wt. thermoplastic polyester resin (A), 50-800 pts.wt. crystalline propylene resin (B), and 10-100 pts.wt. modified olefin resin (C), and the sum of the amts. of components B and C is the same as or higher than the amt. of component A. Component C, a modified olefinic resin, is produced by grafiting 0.01-20 pts.wt. α,Β-unsatd. carboxyic ester and 0.01-50 pts.wt. arom. vinyl compd. onto 100 pts.wt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretched resin film having excellent heat resistance, writability and printability, which is particularly suitable for use as synthetic paper. This stretched resin film does not undergo heat shrinkage at a temperature of about 100 ° C. and is strong, so that it does not curl even if heat is applied during printing. Therefore, outdoor poster paper, label paper, drafting paper, sticker paper, etc., as well as support for bar code paper, photographic paper, thermal recording paper, and thermal transfer image receiving paper using hot melt adhesive at 80-100 ° C. It is useful as a body. In particular, it is suitable for an electrophotographic system and a printing system by toner heat fixing such as a laser printer and an LED printer.

[0002]

2. Description of the Related Art Conventionally, electrophotographic printing and printing by thermal fixing of toner in laser printers, LED printers and the like have been used as high-quality processed paper (pulp-making paper ) Was mainly used. On the other hand, with the increasing use of management adhesive labels that use bar codes for production management and product management, and computerization and speeding up, laser printers and LED printers that are excellent in quietness and high speed have become printers. The use of etc. is becoming popular. These pressure-sensitive adhesive labels for management require strength such as water resistance and abrasion resistance and stain resistance depending on the application, and it is difficult to apply them to conventional labels based on pulp paper.

For this reason, attempts have been made to use water-resistant plastic films or polyolefin resin synthetic papers. However, for toner thermal fixing of electrophotographic systems, laser printers, LED printers, etc., it is necessary to melt the low melting point polyester used as the binder of the toner, so the fixing roll is heated at a high temperature (about 150 to 200 ° C.) depending on the printing speed. become.

Therefore, the melting point of the conventional polyolefin resin synthetic paper (Japanese Patent Publication No. 46-40794) is 17
Stretching temperature below 120C and below melting point (120-163
Since it is highly stretched at (° C.), it is exposed to a temperature higher than the stretching temperature or a temperature near the stretching temperature for a short time, but after the toner is fixed, a large curl occurs on the inner surface of the print, There was a problem that was difficult to handle. On the other hand, a polyethylene terephthalate-based resin biaxially stretched film containing a polyolefin-based resin polymer is known as a plastic film having excellent heat resistance (JP-A-57-49648). However, this polyethylene terephthalate-based resin film has excellent heat resistance, but since it contains a small amount of the polyolefin-based resin, it does not feel as soft as the above-mentioned polyolefin-based synthetic paper, and also has paper feeding / discharging properties. There was a problem that it was inferior to.

In order to solve this problem, a polypropylene resin is used as a matrix, a small amount of a polyester resin is added, and maleic anhydride or the like is added as a compatibilizing agent. , A biaxially stretched film having excellent heat resistance has been proposed (JP-A-2-2).
76841). However, since such a compatibilizer lacks compatibility between polypropylene and polyester, the recrystallization temperature of the blended polyester resin is lower than (120 to 130).
Since it is difficult to stretch the polyester resin in a non-crystalline state at (° C.), the above resin composition was stretched at the recrystallization temperature of the polyester resin or higher. In this method, since the polyester resin is crystallized, the polyester resin cannot be highly stretched, and a stretched film having sufficiently high heat resistance cannot be obtained.

[0006]

The present invention makes it possible to stretch at a temperature not higher than the recrystallization temperature of the polyester resin by blending a more excellent compatibilizing agent, and at a temperature not lower than the recrystallization temperature of the polyester resin. By heat-treating at a temperature lower than the melting point of the matrix polyolefin resin to crystallize the highly stretched polyester resin in the amorphous state, it has excellent heat resistance and the softness of the polyolefin-based synthetic paper. The purpose is to provide a synthetic paper that has a feeling.

[0007]

According to the present invention, a resin composition containing the following (A), (B) and (C) as a base material has a porosity of 5 to 50% by weight and an opacity of 35-10
It is intended to provide a 0% stretched resin film. (A)
(B) based on 100 parts by weight of the thermoplastic polyester resin
50 to 800 parts by weight of a crystalline propylene-based resin, and
(C) A resin composition in which a modified olefin resin obtained by the following production method is mixed in a proportion of 10 to 100 parts by weight, and the sum of the components (B) and (C) is the component (A). Or more.

Production method of component (C): olefin resin 10
A modified olefin is obtained by subjecting 0.01 to 20 parts by weight of an α, β-unsaturated carboxylic acid ester monomer having a hydroxyl group to 0 part by weight and 0.01 to 50 parts by weight of an aromatic vinyl compound to a graft polymerization step. A system resin is manufactured.

[0009]

[Detailed Description of the Invention]

(1) Constituent Component (A) Component: Thermoplastic Polyester Resin The thermoplastic polyester resin used in the present invention includes one or more dicarboxylic acids or lower alkyl diesters thereof, for example, terephthalic acid, isophthalic acid, 2,
5-, 2,6- or 2,7-naphthalenedicarboxylic acid,
Succinic acid, sebacic acid, adipic acid, azelaic acid, biphenyl-4,4'-dicarboxylic acid, hexahydroterephthalic acid, bis-p-carboxyphenoxyethane, etc.
And one or more glycols such as ethylene glycol, 1,3-propanediol, neopentyl glycol, and 1,4-cyclohexanedimethanol can be produced by condensation with an oxycarboxylic acid, if necessary. The preferred resin is polyethylene terephthalate. The polyester resin used in the present invention may be a polyester copolymer containing a mixed hydroxyl group and / or an ester-forming acid group, or may be a block copolymer composed of different polyesters.

Component (B): Crystalline propylene-based resin The crystalline propylene-based resin used in the present invention is a resin mainly containing propylene, specifically, a propylene homopolymer and propylene as a main component. , Ethylene, butene-1, hexene-1, heptene-1, 4-methylpentene-1, 3-methylpentene-1, etc., and a copolymer with one or more α-olefins. This copolymer may be a random copolymer or a block copolymer.

Among these crystalline propylene resins, propylene homopolymer and propylene / ethylene copolymer are particularly preferable. Melt flow rate of these crystalline propylene-based resins (JIS K-7210; 230 ° C., 2.
16 kg load) is 0.3 to 50 g / 10 minutes, especially 0.6
-12 g / 10 min, melting point 130-190 ° C, especially 14
It is preferably 5 to 178 ° C. The crystallinity is 2
0 to 75%. It is also possible to use a mixture of propylene homopolymer and propylene-based copolymer.

Component (C): Modified Olefin Resin The modified olefin resin used in the present invention is a graft copolymer of an α, β-unsaturated carboxylic acid ester monomer having a hydroxyl group and an aromatic vinyl compound with an olefin resin. It is polymerized. Further, the ratio of the hydroxyl groups contained in the modified olefin resin to the total amount of the hydroxyl groups contained in the graft-polymerized α, β-unsaturated carboxylic acid ester-based monomer, that is, the hydroxyl group residual rate is 0.3 to 1. Modified products in the range of 0 are preferred. A specific method for measuring the residual ratio of hydroxyl groups will be described in the section of Examples below.

Examples of the α, β-unsaturated carboxylic acid ester-based monomer having a hydroxyl group for modifying the olefin resin include 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 2,3-dihydroxypropyl methacrylate, 2,3-dihydroxypropyl acrylate, 2
-Hydroxymethyl-3-hydroxypropyl methacrylate, 2-hydroxymethyl-3-hydroxypropyl acrylate, 2,2-dihydroxymethyl-3-hydroxypropyl methacrylate, 2,2-dihydroxymethyl-3-hydroxypropyl acrylate, carbon number 4 -40 to 40 ethylene glycol or propylene glycol oligomer methacrylic acid ester or acrylic acid ester; bis (2-hydroxyethyl) malate, bis (2-hydroxyethyl) fumarate, bis (2-hydroxypropyl) malate, bis (2- Hydroxypropyl) fumarate, bis (2,3-hydroxypropyl) malate, bis (2,3-hydroxypropyl) fumarate, bis (2-hydroxymethyl-3-)
Hydroxypropyl) malate, bis (2-hydroxymethyl-3-hydroxypropyl) fumarate, bis (2,2-hydroxymethyl-3-hydroxypropyl) malate, bis (2,2-hydroxymethyl-3-)
Examples thereof include hydroxypropyl) fumarate, maleic acid ester or fumaric acid ester of an oligomer of ethylene glycol or propylene glycol having 4 to 40 carbon atoms.

The maleic acid ester or fumaric acid ester is not only the one in which two carboxyalkyl groups are both esterified with a hydroxyalkyl group as described above, but a half ester in which only one is esterified. However, it can be exemplified as a similar monomer. The above unsaturated carboxylic acid esters having a hydroxyl group can be used alone or in combination of two or more. Among these, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, methacrylic acid ester or acrylic acid ester of oligomer of ethylene glycol or propylene glycol having 4 to 40 carbon atoms is preferable. .

Examples of the aromatic vinyl compound for modifying the olefin resin include styrene, α-methoxystyrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, dimethylstyrene and 2,4,6-trimethyl. Styrene, chlorostyrene, dichlorostyrene, bromostyrene, nitrostyrene, chloromethylstyrene,
Aromatic vinyl-based monomers such as cyanostyrene, t-butylstyrene, and vinylnaphthalene can be used.
Among these, styrene, α-methoxystyrene, α-
Methylstyrene is preferred. These are either alone or 2
They can be used in combination of two or more kinds.

As the olefin resin modified with the α, β-unsaturated carboxylic acid ester monomer having a hydroxyl group and the aromatic vinyl compound, the same crystalline propylene resin as the above component (B) is used. it can. Also, high density polyethylene, branched polyethylene, linear polyethylene,
Poly (4-methylpentene-1), styrene / butadiene / styrene block copolymers and hydrogenated products thereof,
Styrene / isoprene / styrene block copolymers and hydrogenated products thereof, ethylene / vinyl acetate copolymers, ethylene / glycidyl methacrylate copolymers, ethylene / vinyl acetate / glycidyl methacrylate copolymers and the like can also be used. These may be used alone or in combination of two or more.

Examples of the method for modifying an olefin resin with the above-mentioned α, β-unsaturated carboxylic acid ester monomer having a hydroxyl group and an aromatic vinyl compound include, for example, an α, β-unsaturated resin having an olefin resin and a hydroxyl group. A method in which a saturated carboxylic acid ester-based monomer and an aromatic vinyl compound are allowed to coexist and reacted in the presence or absence of a radical generator such as an organic peroxide, a method of irradiating ultraviolet rays or radiation, or oxygen or There is a method of contacting with ozone.

A method for producing a modified olefin resin in which the residual ratio of the hydroxyl groups of the α, β-unsaturated carboxylic acid ester having a hydroxyl group graft-polymerized to the olefin resin is in the range of 0.3 to 1.0 is Any method can be used as long as the α, β-unsaturated carboxylic acid ester system having a hydroxyl group, which is graft-polymerized with the olefin resin, does not lose the hydroxyl group that can effectively react with the thermoplastic polyester resin. Good.

The amount of the α, β-unsaturated carboxylic acid ester monomer having a hydroxyl group introduced into the olefin resin is
0.01 to 20 relative to 100 parts by weight of olefin resin
Parts by weight, preferably 0.05 to 10 parts by weight. If the amount of the α, β-unsaturated carboxylic acid ester monomer having a hydroxyl group is less than 0.01 part by weight, the effect of improving the compatibility is small, and if it exceeds 20 parts by weight, there is a problem in moldability due to gelation or the like. It is not preferred.

The amount of the vinyl compound introduced into the olefin resin is 0.0 based on 100 parts by weight of the olefin resin.
It is 1 to 50 parts by weight, preferably 0.05 to 20 parts by weight. If the amount of the aromatic vinyl compound is less than 0.01 part by weight, the effect of improving the compatibility is small, and if it exceeds 50 parts by weight, the appearance of the product may be deteriorated or the mechanical strength may be deteriorated, which is not preferable. In addition, the ratio (a) :( b) of the α, β-unsaturated carboxylic acid ester monomer having a hydroxyl group (a) and the aromatic vinyl compound (b) is 1:99 by weight.
The range is preferably from 99 to 1 and more preferably from 10 to 9
It is in the range of 0 to 90:10. If the amount is out of these ranges, the effect of improving the compatibility becomes small, making it difficult to stretch or making the stretched film brittle.

The residual ratio of the hydroxyl group of the α, β-unsaturated carboxylic acid ester having a hydroxyl group graft-polymerized to the olefin resin is preferably in the range of 0.3 to 1.0, more preferably 0.4 to 1. The range is 0. When the residual ratio of hydroxyl groups is less than 0.3, the improvement effect becomes small, which is not preferable. The modified olefin resin has an MFR measured according to JIS K7201 of preferably 0.01 to 200 g / 10 minutes, more preferably 0.1 to 100 g / 10 minutes.

(D) Additional Components The film-forming resin component of the present invention may contain a stabilizer, an ultraviolet absorber, a dispersant, a dye, a pigment and the like in addition to the above components. If necessary, 30% by weight or less of the propylene resin (B) may be replaced with high density polyethylene, linear low density polyethylene, nylon 6, nylon 66, or the like.

Resin composition The resin composition of the base material is such that (A) 100 parts by weight of the thermoplastic polyester resin, and (B) the crystalline propylene resin 5
0-800 parts by weight, preferably 80-600 parts by weight,
(C) Modified olefin resin 10 to 100 parts by weight, preferably 35 to 100 parts by weight, and the sum of the amounts of the components (B) and (C) of the olefin resin is the amount of component (A). Or more.

The compounding amount of the component (A) is defined as the compounding amount of the component (B) and the component (C) in order to give a soft feeling to the film by using the olefin resin as a matrix of the biaxially stretched film. is there. When the sum of the blending amounts of the components (B) and (C) with respect to 100 parts by weight of the component (A) exceeds 900 parts by weight, the amount of minute voids (microvoids) generated inside the film due to stretching is small, and the pencil Writability and opacity are impaired. On the other hand, if the amount of the component (A) is too large, the stretchability is impaired and the heat resistance of the biaxially stretched film is lowered. When the blending amount of the component (C) is less than 10 parts by weight, the compatibility between the component (A) and the component (B) is insufficient and the proper temperature range for stretching is narrowed. On the contrary, when the amount exceeds 100 parts by weight, the amount of microvoids generated is small, and the drying property, opacity and heat resistance of the ink of the biaxially stretched film are impaired.

(2) Production of Stretched Film In the stretched film of the present invention, a resin composition containing (A) a thermoplastic polyester resin, (B) a propylene resin, and (C) a modified olefin resin is used in an extruder. A temperature above the melting point of the polyester resin used, eg 260 to 30
The thermoplastic polyester resin is dispersed in the propylene-based resin by kneading at 0 ° C., and the thermoplastic polyester resin is extruded into a film form from the die while the thermoplastic polyester resin is present in the amorphous state. At a recrystallization temperature or lower (for example, 60 to 120 ° C.), 3.5 to 12 times in at least one direction, preferably 3.5 to 5.5 times in the extrusion direction (MD) and 4 to 4 times in the width direction (TD).
Stretch 12 times. Furthermore, the recrystallization temperature of the polyester resin or higher (for example, in the case of polyethylene terephthalate, 13
It is obtained by performing heat setting at 0 to 170 ° C.) to recrystallize the polyester resin.

If desired, when the stretched film of the present invention is produced, it may be laminated with another resin layer. Examples of the other resin layer include olefin resins such as ethylene resin and propylene resin, saturated polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins such as nylon 6 and nylon 6,6, polyvinyl chloride, polystyrene. Etc. can be mentioned. Such other resin layers include calcium carbonate, titanium dioxide,
50% filler such as clay and barium sulfate in the resin composition.
The resin composition may contain 2% by weight or less of a UV agent, antioxidant and the like. At this time, the stretched film using the resin composition of the present invention as a base material may be a biaxially stretched film or a uniaxially stretched film.

(3) Stretched Film The stretched film of the present invention has a porosity of 5 calculated by the following equation.
.About.50%, preferably 12 to 35%, with opacity (JI
SP-8138) is 35 to 100%, preferably 65
~ 100%.

[0028]

[Equation 1]

Stretching causes microvoids inside the film, which reduces the weight of the stretched film and makes it semi-transparent.
It is made opaque, and the surface of the stretched film is roughened (matted). The degree of the rough surface is determined by the Beck index (JI
SP-8119) is about 800 to 6,000 seconds, preferably 1,000 to 4,500 seconds. The thickness of the stretched film is 20 to 300 μm, preferably 40 to 150 μm when the stretched film is a single layer of the substrate of the present invention. 1 to 1 when used as a laminated film of two or more layers
50 μm, preferably 3 to 120 μm, and another thickness is filled with another layer so that the thickness of the laminated film is 30 to 3
It is set to be 00 μm.

(4) Uses The stretched resin film of the present invention is used as a poster paper, a drawing paper, a label paper itself, or as a film alone or laminated with paper, polyester, etc. By providing a heat-sensitive recording coating layer and an image-receiving recording layer, it is useful as a support for use as photographic paper, heat-sensitive recording paper and thermal transfer image-receiving paper. In particular, it is suitable for an electrophotographic method and a printing method by toner heat fixing such as a laser printer and an LED printer.

[0031]

EXAMPLES The present invention will be described in more detail with reference to the following experimental examples. The evaluations in Examples and Comparative Examples were evaluated by the evaluation methods shown below. [I] Evaluation method Opacity : JIS-P8138 Surface smoothness : JIS-P8119 Stability of stretching : When 10 test pieces were carried out, breakage or detachment of the chuck did not occur during stretching, and stretching was completed to the end. The score of the test piece is measured.

After the heat shrinkage test piece was left in the terminal-free state for 30 minutes and 10 minutes in the circulation type constant temperature bath at 120 ° C. and 150 ° C., respectively, the dimensional change (original length) of the test piece was measured. L ₀ and the length L) after standing were measured, and the heat shrinkage rate was calculated by the following formula.

[0033]

[Equation 2]

Tensile Elastic Modulus Tensilon manufactured by Orientec Co., Ltd. was measured at a tension rate of 20 mm / min under the conditions of a temperature of 23 ° C. and a relative humidity of 50%. Curl height stretched film is cut into 200 mm length and 200 mm width,
The test piece was used. The test piece was test-printed with a laser printer (Cannon A404GII), and face-up paper was passed (printed surface was facing upward). The average value (mm) of the floating heights (4 corners) when this was placed on a flat surface for 1 minute under the conditions of a temperature of 23 ° C. and a relative humidity of 50% was obtained.

The pencil writing property Toyo Seiki Co., Ltd. pencil hardness tester (scratch tester)
Using a pencil, apply a load of 200 g to a pencil of hardness H set so as to be perpendicular to the obtained synthetic paper, and apply 200
A line segment is drawn at a speed of sec / m, and this line segment is visually observed and judged as follows. ○: Can be read clearly. Δ: Written but thin and difficult to read. X: Almost not written.

[II] Example Reference Example 1 : Method for producing modified olefin resin Propylene homopolymer powder (MFR at 230 ° C. is 1 g /
10 minutes, DSC peak temperature 164 ° C, melting end temperature 1
76 ° C.) 2,000 g, 2-hydroxyethyl methacrylate 60 g, styrene 40 g and t-butyl peroxybenzoate 20 g were mixed with a super mixer, and then a cylinder temperature of 180 ° C. was obtained using a twin-screw extruder (manufactured by Japan Steel Works). Then, the mixture was kneaded under reduced pressure at a screw rotation speed of 250 rpm to obtain modified olefin resin pellets.

0.3 g of this pellet was added to 20 ml of xylene.
After completely dissolving in 110 ° C at a temperature of 150 ° C, methanol
The mixture was poured into a mixture, the product was precipitated, and filtration and washing were performed twice. Then, the product was dried under reduced pressure to obtain a purified modified olefin resin. The content of 2-hydroxyethyl methacrylate obtained by the following method in this purified modified olefin resin was 31% by IR method and 0.94% by NMR method, and the residual ratio of hydroxyl group was 0.72. . Similarly, the styrene content of this purified modified olefin resin was determined by using the peak at 700 cm ^-1 derived from monosubstituted benzene by the IR method. The result was 0.80%.

Method for measuring residual rate of hydroxyl group: (1) Infrared spectroscopy (hereinafter referred to as "IR method"): A purified modified olefin resin is formed into a film by using a press, and an infrared spectroscopy spectrum is measured to obtain carbonyl. The content of α, β-unsaturated carboxylic acid ester was determined from the absorption at 1724 cm ⁻¹ derived from a calibration curve prepared in advance.

(2) Proton nuclear magnetic resonance method (hereinafter referred to as "NM
R method): 50 m of purified modified olefin resin
g was dissolved in about 2 ml of o-dichlorobenzene with heating at 130 ° C., a sample was prepared using deuterated benzene as a standard substance, and the NMR spectrum was measured to determine the hydrogen group-bonded methylene (chemical shift: 3.7 ppm). And the content of α, β-unsaturated carboxylic acid ester was quantified using the absorption of methylene (chemical shift: 4.2 ppm) bound thereto. Using the ratio of the contents obtained by these two kinds of measuring methods, the residual ratio of hydroxyl groups was calculated from the following formula.

[0040]

(Equation 3)

Example 1 100 parts by weight of polyethylene terephthalate "Belpet PBK-1" (trade name) manufactured by Kanebo Co., Ltd. and propylene homopolymer "TA3" (trade name: M) manufactured by Mitsubishi Chemical Co., Ltd.
FR 1.6 g / 10 minutes, crystallinity 67%, DSC melting end temperature 174 ° C.) and propylene homopolymer “TA-8”
(Product name: MFR 8g / 10 minutes, crystallinity 60%, DS
A resin composition obtained by mixing 232 parts by weight of a 1: 1 mixture having a C melting end temperature of 172 ° C.) and 100 parts by weight of the modified olefin resin obtained in the above-mentioned Reference Example with a tumbler was loaded on a twin-screw extruder (manufactured by Japan Steel Works) Using the cylinder set temperature 270
° C, screw rotation speed 250 rpm, discharge amount 20 kg /
Melt and knead at a certain time and extrude into a strand from the die, 3
After cooling to 0 to 40 ° C, cutting was performed to obtain pellets.

The obtained pellets were melted and kneaded by a single-screw extruder (manufactured by Japan Steel Works) set at 260 ° C., extruded into a sheet form from a die, and immediately cooled to a temperature of 80 ° C. to have a thickness of 1. A 5 mm sheet was obtained. This sheet, 120
mm and 120 mm in width were cut out to obtain test pieces. This test piece was heated to 120 ° C. with a small biaxial stretching machine (manufactured by Iwamoto Seisakusho) and preheated for 1 minute, and then at a stretching speed of 10 mm / sec,
At the same time, it was stretched 4 × 4 times in the biaxial direction. Next, at 155 ° C., an annealing treatment was carried out for 15 minutes with the terminals fixed to obtain a stretched film.

Table 1 shows the density, porosity, opacity, Bekk smoothness, tensile modulus, stretching stability, heat shrinkage rate, and curl height of the obtained stretched film. Examples 2 to 5 and Comparative Examples 1 to 3 A stretched film was prepared in the same manner as in Example 1 except that the blending and stretching temperatures in Example 1 were changed to the blending and stretching temperatures shown in Table 1. Evaluation was carried out in the same manner as in Example 1. Table 1 shows the evaluation results.

[0044]

[Table 1]

The stretched resin film of the present invention is a film excellent in heat resistance and softness.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location // B29K 67:00 B29L 7:00 (72) Inventor Yasumitsu Uno 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Co., Ltd. Yokkaichi Research Institute (72) Inventor Kayo Ito, Tokamachi, Yokkaichi, Mie Prefecture Mitsubishi Chemical Co., Ltd. Yokkaichi Research Institute

Claims (2)

[Claims] 1. A porosity of 5 to 50% by weight based on a resin composition containing the following (A), (B) and (C):
A resin stretched film having an opacity of 35 to 100%. (A)
(B) based on 100 parts by weight of the thermoplastic polyester resin
50 to 800 parts by weight of a crystalline propylene-based resin, and
(C) A resin composition in which a modified olefin resin obtained by the following production method is mixed in a proportion of 10 to 100 parts by weight, and the sum of the components (B) and (C) is the component (A). Or more. Production method of component (C): 0.01 to 20 parts by weight of an α, β-unsaturated carboxylic acid ester monomer having a hydroxyl group in 100 parts by weight of an olefin resin and an aromatic vinyl compound of 0.
A modified olefin resin is manufactured by subjecting 01 to 50 parts by weight to a graft polymerization step. 2. The component (C) comprises a crystalline propylene resin as an olefin resin, 2-hydroxyethyl methacrylate as an α, β-unsaturated carboxylic acid ester monomer having a hydroxyl group, and an aromatic vinyl compound. The stretched resin film according to claim 1, which is produced by subjecting styrene to a graft polymerization step and has a hydroxyl group residual ratio of 0.3 to 1.0.