JPS61273941A - Porous resin laminated film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a porous resin laminate film having surface strength and an excellent air permeability ratio useful for disposable diapers, sanitary napkins, electrolytic diaphragms, and the like.

[Prior art]

Polyolefin porous wood with breathable and waterproof properties for sanitary napkins and disposable diapers! ”,1
Greasy film is used as an anti-corrosion material.

9. Such a porous single-resin film is made of high-density polyethylene, linear polyethylene, or a mixture of both as the resin material, and is coated with calcium carbonate, titanium oxide, fired clay, and diatomaceous earth. R4,4 fine powder such as polyethylene wax, liquid butadiene rubber, liquid imbutylene rubber, liquid polyethylene rubber, liquid polyethylene wax, liquid hydrogenated castor oil, etc., as required. - Melt the blended composition into a film using an extruder, melt-form it, and then stretch-form it using a mandrel and a circumferential speed difference between the roll groups using a stretching device or a tenter.
It is manufactured by
%Opening 1985-47□ ltu, 33"3・0゛-203520@・l
'q5B-15゛・, No. 538, 5B
-149925, 5B-14 page.

19303, No. 59-62117, No. 59-14, No. 0235, No. 60-6442).

゛ [Problems with conventional technology]′
This porous resin film has a core of inorganic fine powder; it has a large number of fine continuous pores, and the surface has pores communicating with the atmosphere, making it an air permeable single-layer l-axis stretched film or two layers. This axially stretched film is useful as a waterproof cover sheet for disposable diapers.

When this porous resin film is used as a waterproof cover sheet for disposable diapers, the surface of the porous resin film has a female-patterned paper layer of 61 mm.
-77, □ゎ,. □Yes.゛After attaching the disposable diaper to the baby's crotch, peel off the release paper on the surface of the double-sided adhesive tape and use the exposed adhesive to fix the disposable diaper.

If this adhesive tape is pasted on the wrong position of the porous resin film, or when you want to slightly remove the pasted position, if you peel it off from the diaper to re-stick the adhesive tape, it will work better than the conventional porous resin 2. In the axially stretched film, the inorganic fine powder protrudes from the surface and is exposed either freely or attached to the resin film base material9, and the pores are circular or elliptical and the inorganic fine powder easily falls off. This inorganic fine powder may migrate to the adhesive surface of the adhesive tape, causing a decrease in the adhesive strength of the adhesive tape, or the surface of the porous resin film may peel off like paper flakes due to its low surface strength. be.

On the other hand, in the -axially stretched film, the pores are elongated, and the stretching area magnification is also lower than that of the biaxially stretched film.
Since it is small, the shedding of inorganic fine powder is less than that of a biaxially stretched film, and the surface strength is also stronger than that of a biaxially stretched film. Due to the poor diaper cover, it stretches and loosens during use, making it impossible to satisfy leak-proof properties. In particular, those whose tensile elongation at break exceeds 500% are not preferred.

[Specific means for solving the problem] In the present invention, the porous resin film is made of a double I-groove structure of a biaxially stretched film and a uniaxially stretched film, and the biaxially stretched film of equal material layers is made to The surface layer to which the adhesive tape is attached is made of a porous resin-axially stretched film containing a potless fine powder, thereby improving the surface strength and reducing the electric charge of the inorganic fine powder that transfers to the adhesive tape. This solves the above problems.

That is, the present invention includes a biaxially stretched porous film (4) of polyolefin containing 50 to 75% by weight+t% of inorganic fine powder as a base layer;
A porous resin laminated film comprising a surface layer made of a uniaxially stretched porous film containing polyolefin at a ratio of 1% by weight, the porous resin laminated film comprising:
The air permeability at °C is 40-7.000 seconds, and at 20 °C
The moisture permeability is 100 to 10,000 t/rr?
The present invention provides a porous resin laminate film characterized in that the pressure is 1J11 atm at 0.024 hours.

(Resin) In the practice of the present invention, the polyolefin as the resin material for each layer and (day) 1 includes high density polyethylene, linear polyethylene, low density polyethylene, polyflopylene, ethylene/furopylene copolymer, polybutene, etc. Polyolefins or mixtures of two or more of these can be cited, and in particular, when considering waterproof cover sheets for industrial fabrics, polyolefins have a specific gravity of 0.92 to 0.97 and a melt index (MI) of 0.06 to 1 f/. High-density polyethylene for 10 minutes (190℃): 65-30% polyethylene
, specific gravity is 0.91-0.94, MI is 0.1-10
When a mixture of linear polyethylene with an f/I of 0 minutes and 35% to 0% of heavy failures is used, the resulting porous resin film has a good texture and touch.

(Inorganic fine powder) Inorganic fine powder has an average particle size of 20 microns or less,
Preferably, those having a diameter of 3 microns or less are used, and examples thereof include calcium carbonate, diatomaceous earth, calcined clay, aluminum silicate, and talc.

(Optional ingredients) In addition to polyolefin and inorganic fine powder, stabilizers, pigments, dispersants, plasticizers, antistatic agents, liquid butadiene rubber, polyethylene wax, liquid imbutylene rubber,
Attack polypropylene, dibutyl phthalate, liquid hydrogenated castor oil, etc. may be blended.

(Laminated film) The porous laminated film contains 50 to 75% of inorganic fine powder.
Polyolefin (containing 2%) is melt-kneaded using an extruder, extruded into a sheet through a trowel, cooled to a temperature much lower than the melting point of the polyolefin, and then heated to a temperature at which it can be stretched, usually 3 to 35°C above the melting point. low 1ulf
), after stretching the longitudinally stretched film 1.3 to 7 times, preferably 1.8 to 5 times, using the peripheral speed difference between the roll groups, inorganic fine powder is applied to one or both sides of the longitudinally stretched film. 55-75
Melt-laminate a molten film of polyolefin (B) containing polyolefin (B), and after cooling the film to a temperature lower than the melting point of the polyolefin, use a tenter to obtain a film of 1.2 to 1.
It is produced by stretching in the transverse direction by 0 times, preferably 1.2 to 3.5 times, followed by heat treatment if necessary, cooling, and slitting the edges.

Other manufacturing examples include using resin or inorganic fine powder for the base layer film and/or surface layer film.
It is also possible to produce a laminated film of a composition having a different blending amount.
1゜This porous resin laminated film is JISZ-
At 20℃ due to +0208, moisture permeability is 100~
to, ooor/-・24 hours・1 atm, preferably 2
00~5.0OOf/r#・24 hours #1 atm,
and the air permeability at 20°C measured by the following method is 40 to 7,000 seconds, preferably 1
00 to 4.000 seconds.

1. Measuring method of air permeability: 5', earthenware made in accordance with JIS P-8117) Pa° type air permeability (smoothness tester (Asahi Seiko #)
If the air permeability and moisture permeability are out of the above range, the pores, - ゛・: The elastic layer film can be used as a waterproof cover for diapers or as a one-time history 3゛・“:・□・ When used as a leak-proof material for sanitary napkins, it tends to get stuffy or is not liquid-proof.

,( 1. (Effect) □.

Since the porous laminated film of the present invention includes a biaxially stretched film base material layer, it has excellent strength balance and less creep elongation and tearing. In addition, the inorganic fine powder of the per-axially stretched film (6) on the surface layer protrudes, giving a matte finish (rough surface).
Therefore, when this porous resin laminated film is embossed, the outer film is similar to cloth and has a good feel. In addition, the protruding (uniformly layered inorganic fine powder is the surface layer (6)
Since it is a -axially stretched film, it is less likely to fall off from the film surface, and since the degree of fibrillation on the surface is low, the surface strength is stronger than that of a biaxially stretched film, and the surface does not peel off like paper flakes. Paper dust problems (adhesion failure of adhesive tape) are less likely to occur.

Example 1 (1) Density 0.92y/d, melt index 1
, 20 parts by weight of or/lo linear polyethylene V, density 0
．． 95 t/cril, melt index 0.089
A resin composition (4) consisting of 20 parts by weight of high-density polyethylene of 710 min and 60 parts by weight of calcium carbonate with an average particle size of 1.8 microns was melt-kneaded using an extruder.
Extrude it into a sheet from a die at ℃, and heat this sheet to 70℃.
After cooling to 110°C, the film was heated to 110°C and stretched 2.5 times in the longitudinal direction using the difference in circumferential speed between the roll groups to obtain a longitudinally stretched film.

(2) Density o, tazt/ad, melt index 1
, o t/20 parts by weight of linear polyethylene for 1 o,
Density 0.95 t/ad, melt index 0.089": / 20 parts by weight of high-density polyethylene for one layer and 60 parts by weight of calcium carbonate with an average particle size of 1.8 microns. Yoshinaru resin composition (melt mixed using an extruder, l
ij, i, j, kneaded, extruded into a sheet form from a die, and laminated on both sides of the longitudinally stretched film obtained in 111. (1) above,
Cool it to 60℃, then introduce it into a heated open, and heat it for about 1 hour.
``'''t After heating to 14℃, it was stretched 2.51 times in the transverse 1' direction using a tenter, heat treated at about 118℃, and then cooled to 50℃. Then, slit the ears to make (6)\゛53(/(2)/■ each thickness 10μ740μ/10μ
No.3,゛・1,,Pa 1 Remains 1-I got the film.

The air permeability (20℃) and moisture permeability of this laminated film (20℃)
℃) Paper powder trub degree and creep degree (JIS P-
Tensile failure groan measured at 8132. )8,
are shown in Table 1.

゛The degree of paper dust trouble is measured by the following method. , 61 ,, Ta.

゛ Adhesive tape, center, 7a, tape” (=
After adhering LP-18 (trade name, manufactured by Chih Ng) to the film surface and rubbing it 5 times with the pad of the thumb, the adhesive tape was peeled off at a speed of 200+w+/min using Tensilon (manufactured by Toyo Boldbowin).

The amount of light transmitted through this adhesive tape was measured using a color meter (manufactured by Suga Test Instruments).

In advance, the amount of light transmitted through the adhesive tape before adhesion was measured as one blank, and the value divided by this was taken as the light transmittance (the larger the value, the fewer problems with paper dust).
.

Those with a light transmittance of 80% or less were noted as having some problems with the light transmittance, and those with a light transmittance of 70% or less were noted as defective.

In addition, when the surface layer of the porous resin film was broken during peeling, and the light transmittance could not be measured, it was described as a defective film.

Examples 2-7, Comparative Examples 1-a
i=change the ratio or stretching ratio of each composition as shown in Table 1, or change the thickness of each layer as shown in the table.Ike was a two-layer or three-layer laminated film in the same manner as in Example 1. Obtained.

□ The air permeability, moisture permeability, paper dust resistance, and creep degree of these laminated films are shown in the same table.

Comparative Example 4 Density o, 92 t/cd% Melt index 1. 20 parts by weight of linear polyethylene of/10 minutes, density '2 O, 95f/Cj, melt index o, o s t/1°11, 201 parts of high density polyethylene of minutes and average particle size '
A resin composition consisting of 60 parts by weight of calcium carbonate with a diameter of 1.8 microns was melt-kneaded using an extruder and heated to 220°C.
The mixture was extruded from a die into a sheet, and this sheet was cooled to 70°C.

This sheet was heated to 110° C. and stretched 2.5 times in the longitudinal direction using the difference in circumferential speed between the 9-l groups to obtain a longitudinally stretched film.

Table 1 shows the physical properties of this axially stretched film.

□ Comparative Example 5 The longitudinally stretched film of Comparative Row 4 was further heated by 56...
After heating it to about 114°C, it was stretched twice in the transverse direction using a tenter.
After the heat treatment at ℃, it was cooled to 50 ℃, and the edges were slit to obtain a 50μ two-sleeved stretched film tL%.

Table 1 shows the physical properties of this film.

(Margin below)

Claims (1)

[Scope of Claims] 1) A biaxially stretched porous film (A) of polyolefin containing 50 to 75% by weight of inorganic fine powder as a base layer, and 55 to 75% by weight of inorganic fine powder. A porous resin laminated film comprising a surface layer (B) made of a uniaxially stretched porous film of polyolefin containing , a porous resin laminate film having a moisture permeability of 100 to 10,000 g/m^2 at 1 atm for 24 hours at 20°C. 2) The porous resin laminate according to claim 1, characterized in that the tensile elongation at break measured at 20°C based on JIS-P-8132 is 500% or less in both the longitudinal and transverse directions. film. 3) The material resin of the base layer (A) or surface layer (B) has a specific gravity of 0.92 to 0.97 and a melt index of 0.06 to
1g/10min high density polyethylene 65-30% by weight, specific gravity 0.91-0.94, melt index 0.1
~10g/10min linear polyethylene 35-70% by weight
Claim 1 characterized in that it is a mixture of
The porous resin laminate film described in 2. 4) The porous resin laminate film according to claim 1, wherein the film (B) is a uniaxially stretched film with a stretching ratio of 1.2 to 3.5 times.