JPH11245349A - Laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lightweight laminated sheet which maintains flexibility equivalent to a vinyl chloride resin and is good in melt tension and adhesion. SOLUTION: A coating layer is formed on one side or both sides of a polyolefin resin fabric. The layer consists of a polypropylene resin composition having the following properties. (l) A component soluble in xylene at 25 deg.C is 40-80 wt.%. (2) At least one melting peak meassured by a differential scanning calorimeter exists in ranges of 130-170 deg.C and 100-120 deg.C, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated laminate sheet having excellent heat sealability, airtightness, water resistance and breaking strength, obtained by coating one or both surfaces of a polyolefin resin woven fabric with a thermoplastic resin. . More specifically, the present invention relates to a laminated laminate sheet suitable for applications such as a tent, a curing sheet, a flexible container, a leisure sheet, a loading hood, a blindfold sheet at a construction site, and an air duct.

[0002]

2. Description of the Related Art Tent-shaped materials such as conventional curing sheets, flexible containers, leisure sheets, hoods for loading, blind sheets at construction sites, air ducts, and the like include polyester-based synthetic resins and polyamide-based synthetic resins. Fiber,
A fabric made of a soft tarpaulin having a coating layer formed of a polyvinyl chloride resin or rubber on the surface of a woven fabric made of other fibers has been used. As the coating layer, polyvinyl chloride resin is most commonly used, but a large amount of a plasticizer is blended with the polyvinyl chloride resin for the purpose of improving thermal stability and flexibility. Therefore, liquid components bleed and migrate to the filling,
It is easy to get dirty, the specific gravity of the resin itself is heavy, workability is inferior, and toxic hydrogen chloride gas is generated during combustion,
Since it is a source of dioxin, which has become a problem in recent years, problems such as environmental hygiene, handling, and safety have been pointed out.

[0003] As a lightweight and flexible material containing no plasticizer, polyethylene, ethylene-vinyl acetate copolymer,
Ethylene modified materials such as ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer and ethylene-maleic acid copolymer, and polyolefin-based materials such as polypropylene have been receiving attention. Among them, a woven fabric made of a drawn yarn of polypropylene resin has been recently developed, and has a high strength,
It is advantageous in light weight and heat resistance. As its coating layer,
Low-density polyethylene and its modified material, ethylene-vinyl acetate copolymer, are considered, but these materials are inferior in tear strength and piercing strength and have a melting point of 70 to 1.
The heat resistance is as low as about 20 ° C., and there is a problem of odor. There is also a disadvantage that the adhesive strength between the polypropylene resin and the woven fabric is weak. Conventional polypropylene resins are considered to be unsuitable for extrusion lamination molding on a woven fabric substrate because they lack flexibility and melt tension.

[0004]

SUMMARY OF THE INVENTION The present invention uses a polyolefin resin which is lightweight and excellent in hygiene, and has excellent tear strength, piercing strength and heat resistance while maintaining the same flexibility as a vinyl chloride resin. It is an object of the present invention to provide a laminated sheet having excellent adhesive strength with a polyolefin resin woven fabric as a material and excellent suitability for extrusion lamination.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, can solve the above object by coating a woven fabric of polyolefin resin with a specific polypropylene resin. The present invention has been found, and the present invention has been completed. That is, the present invention is a laminated laminate sheet having a coating layer on one or both sides of a woven fabric of a polyolefin resin, wherein the coating layer is made of a polypropylene resin composition having the following characteristics. It is about a sheet. (1) 40-80% by weight of xylene solubles at 25 ° C
It is. (2) The melting peak measured by a differential scanning calorimeter is 13
At least one exists at each of 0 to 170 ° C and 100 to 120 ° C.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The woven fabric used in the present invention is composed of a polyolefin resin. The polyolefin resin used is not particularly limited as long as it is a polymer containing an olefin as a monomer, for example, a homopolymer or a copolymer, and various polyolefin resins can be used. Examples of such a polyolefin resin include a crystalline homopolymer of propylene and a copolymer of propylene and ethylene and / or an α-olefin of C4 to C8, for example, ethylene and / or C4
Propylene, containing, for example, 0.5 to 15% by weight of α-olefin of C4 to C8 and ethylene and / or α of C4 to C8.
-Crystalline copolymers with olefins and the like can be preferably mentioned.

A woven fabric can be produced, for example, by weaving a drawn yarn of the above polyolefin resin. The drawn yarn can be easily obtained by spinning a polyolefin resin. The drawn yarn is not particularly limited, such as a flat yarn, a multifilament, or a monofilament, as long as sufficient strength can be obtained as a sheet woven fabric. Among them, the flat yarn is most preferably used because it is excellent in high-speed production efficiency and workability.
The flat yarn can be easily formed by using a known technique. The flat yarn is, for example, a film extruded by a T-die method or an inflation method, is slit into a predetermined width to form a tape, stretched in a longitudinal-axial direction by a hot plate or a hot roll to give an orientation, and then heat treated In addition can be obtained. The fineness of the flat yarn is
Usually 500-2000 denier, preferably 800-15
Suitably, it is 00 denier.

[0008] Such a drawn yarn of polyolefin resin can be used, for example, in a circular loom, a sluser type loom,
The fabric is woven using a known weaving machine such as a water jet loom to form a woven fabric. The woven fabric is, for example, using the above-described drawn yarn, and is, for example, a driving density of 10 × 10 to 30 × 3.
It is suitable to weave at 0 / inch, preferably 15 × 15 to 20 × 20 / inch. The coating layer used in the present invention is composed of a soft polypropylene resin. Specifically, the soft polypropylene resin, for example,
It is preferable to use a blend of a high-elastomer component-containing polypropylene obtained by a multi-stage polymerization method as disclosed in JP-A-61-42553 and a low-density polyethylene.

This multistage polymerization method comprises a first stage of homopolymerization of polypropylene or a random copolymerization stage of propylene and a small amount of ethylene, and then a copolymerization stage of a mixture of ethylene and a C3 or more polyolefin. It consists of a polymerization step. Since it is possible to blend at the molecular level in the reactor, unlike the conventional method of blending after polymerization, the ethylene and other components are finely dispersed, making it very flexible, tearing and piercing. A film having excellent strength can be obtained. Specifically, first, in the first-stage reactor, homopolymerization of a propylene monomer or random copolymerization of a propylene monomer and a small amount of ethylene is performed in the presence of a titanium compound catalyst and an aluminum compound catalyst to obtain a propylene polymer. . With the propylene polymer containing the titanium compound catalyst and the aluminum compound catalyst,
The mixture is transferred to the second-stage reactor, and ethylene, propylene, or a monomer having C4 or more is newly added, and a polymerization reaction is performed to obtain a second polyolefin polymer. A multi-stage copolymerization reaction is sequentially performed according to the purpose.

In the conventional block polypropylene copolymer, the content of the block portion copolymerized with propylene, that is, the rubber component composed of the propylene-ethylene and propylene-α-olefin copolymer, is originally determined due to its production process. Was limited to about 50% by weight of propylene. Therefore, it has been extremely difficult to realize flexibility such as plasticized vinyl chloride resin with a polypropylene resin. However, by performing the multi-stage polymerization blend as described above, it becomes possible to contain, for example, 50 to 80% by weight, preferably 60 to 70% by weight of the rubber component composed of the copolymerized portion,
A resin having the same physical properties as the plasticized vinyl chloride resin can be obtained, and it is possible to produce a blend composition that is impossible in terms of resin viscosity by a conventional blending method using an extruder or the like.

The thickness of the coating layer is generally from 10 to 200 μm.
m, preferably 30 to 100 μm. When the coating layer is thinner than 10 μm, the strength, pinhole suitability, and heat sealability of the obtained laminated laminate sheet tend to be poor. On the other hand, the thickness of the coating layer is 200 μm
When it is thicker, the laminated sheet tends to be inferior in flexibility and lightness. 25 of the coating layer used in the present invention
The xylene-soluble content at 0 ° C is 40 to 80% by weight, preferably 50 to 70% by weight. Xylene solubles
When it exceeds 80% by weight, the obtained coating layer is inferior in heat resistance and scratch resistance. On the other hand, when it is less than 40% by weight, the obtained laminated laminate sheet is hardened, the texture is impaired, and the workability is poor. Not preferred.

Here, the xylene-soluble content at 25 ° C. is measured according to the method described in FDA 177.1520 (d) (4) (ii). Further, the coating layer is at least one each at 130 to 170 ° C, preferably 140 to 160 ° C, and 100 to 120 ° C, preferably 105 to 115 ° C, as measured by a differential scanning calorimeter. It is necessary that a melting peak be present. As described above, in each of the two temperature ranges, one melting peak is generated, so that both heat resistance and extrusion lamination suitability can be achieved. Differential scanning calorimeter (D
SC) is a calorimeter used for differential scanning calorimetry,
The differential scanning calorimetry is a method of quantifying a thermal change generated when a sample is heated and lowered at a constant speed as a heat energy amount. The melting peak curve was obtained by dissolving about 3 to 5 mg of a sample at 230 ° C. for 5 minutes using a differential scanning calorimeter.
It is obtained by lowering the temperature to 30 ° C. at a rate of 0 ° C./min, keeping the temperature constant for 5 minutes, and then increasing the temperature to 230 ° C. at a rate of 20 ° C./min.

The coating layer used in the present invention has a melting energy ΔHm (J / g) of a melting peak at 130 to 170 ° C. measured by a differential scanning calorimeter.
It is preferably from 10 to 80 J / g, more preferably from 20 to 50 J / g. Melting energy at this time ΔHm (J / g)
Means the total amount of the area within the range of 130 to 170 ° C. in the area of the portion on the straight line connecting the baselines before and after the peak. The melting energy ΔHm is
It is measured according to JIS K7122. When the melting energy ΔHm (J / g) is less than 10 J / g, the heat resistance and scratch resistance of the coating layer and the adhesive strength to the woven fabric are likely to be inferior. On the other hand, when the melting energy ΔHm (J / g) exceeds 80 J / g, the laminated laminate sheet becomes hard, the texture is easily damaged, and the workability is easily deteriorated.

The peak between 100 and 120 ° C. gives the melt tension required for extrusion lamination suitability.
The melt tension is a tension generated when a resin is uniaxially stretched in a molten state. This melt tension indicates the tension applied to the molten film when the resin extruded as a molten film at the time of extrusion lamination is nipped by a cooling roll and a pressure roll and elongated at a high speed.
Materials such as ordinary linear polypropylene, which lacks melt tension, have a phenomenon called surging or draw resonance in which the film thickness becomes uneven because the force transmitted to the film at the time of elongation is weak, and at a high speed of 100 m / min or more Cannot be extruded and laminated. Such 100-1
Various resin materials can be used as long as they give a peak between 20 ° C. As such a material, for example, low-density polyethylene having a long-chain branching component in the molecular chain and excellent in melt tension is suitable. It is preferable that such low-density polyethylene is added, for example, in an amount of 3 to 40% by weight, preferably 10 to 20% by weight. Such addition provides suitable extrusion lamination suitability. For example, if the amount of the low-density polyethylene is less than 3% by weight, the effect of improving the suitability for extrusion lamination is small, and if it exceeds 40% by weight, the heat resistance and the adhesion to the polyolefin resin woven fabric tend to be poor.

The density of low-density polyethylene is, for example,
880 ~0.925 g / cm ^3, preferably, 0.900 ~0.920g / cm ³
It is. Preferred polypropylene resins are those comprising a multistage polypropylene copolymer and low density polyethylene. Since the multi-stage polypropylene copolymer contains a high proportion of an ethylene component, it has good compatibility with low-density polyethylene and is sufficiently dispersed even in a dry blend.
The components are uniformly dispersed by mixing in a blender such as a Henschel mixer, and then the mixture is subjected to a single screw extruder, a twin screw extruder,
The polypropylene resin used for the coating layer can also be prepared by a conventional method such as forming a mixed composition using a Banbury mixer, a kneader or the like, and pelletizing. The polypropylene resin used for the coating layer may further include, if necessary, conventional additives such as pigments, antioxidants, ultraviolet stabilizers, lubricants, antiblocking agents, antistatic agents, neutralizing agents, flame retardants, and the like. May be included.

The density of the coating layer is, for example, 0.880 to 0.920 g.
/ cm ³ , preferably 0.890 to 0.910. The elastic modulus of the coating layer is, for example, 600 to 1000 kg / cm ² , preferably 700 to 900 kg / cm ² .

[0017]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited by these Examples. The polypropylene material (A) used in the examples is Cataloy KS-3, a reactor-made polypropylene polymer manufactured by Montell.
57P (MFR = 25, 230 ° C.) was used. This is obtained by random copolymerizing propylene and ethylene in the first stage and copolymerizing ethylene and propylene in the second stage. As the low-density polyethylene (B) used in the examples, laminate grade L170 (MFR = 7, 190 ° C.) manufactured by Japan Polyolefin Co., Ltd. was used. As the ethylene-vinyl acetate copolymer used in the comparative example, EVA laminate grade FL14-1 manufactured by Japan Polyolefin Co., Ltd. having a vinyl acetate content of 20% by weight was used.

The polyolefin resin woven fabric used as the base material is a homopolypropylene (MFR = 1.0 g / 10 min),
After the film was formed by the T-die method after being put into an extruder, the film was cut into tapes, and flat denier 1000 denier flat yarn drawn at a draw ratio of 5 times by a hot plate contact drawing method was used as warp and weft. And implantation density 16 ×
A 16 / inch plain weave fabric was produced. Examples 1 and 2 and Comparative Examples 1 to 3 The components indicated by type and blending amount in Table 1 below were dry blended, and an L / D = 24 extruder having a dalmage type screw and a diameter of 65 mm, and an extruder of 600 mm Into a laminating machine having a coat hanger type T-die having a width of 60 μm on both sides of the polypropylene resin woven fabric.
Extrusion lamination was performed at m. Various molding conditions are as follows. Cylinder temperature (℃): 200 ℃ / 240 ℃ / 260 ℃ / 270 ℃ / 280 ℃ adapter, head temperature: 280 ° C. die temperature: 280 ° C. Air gap: 120 mm chill roll temperature: 25 ° C. nip pressure: 3 kg / cm ² was used Table 1 shows the composition and properties of the coating layer and the properties of the obtained woven fabric.

[0019]

Table 1 Table 1 Example Comparative Example 1 1 2 3 2 3 Coating resin (% by weight) KS-357P 90 80 50 100 L170 10 20 50 FL14-1 (Reference) 100 Melting point 106/140 106/140 106/140 140 82 (Peak temperature (° C)) Xylene solubles 55 49 30 60 15 ΔHm (J / g) 28 22 15 30 Peak (peak at 130-170 ° C) Density (g / cm ³ ) 0.902 0.904 0.908 0.900 0.940 Elastic modulus (kg / cm ² ) 750 720 700 780 700 Draw-down property of woven fabric 130 150 180 60 100 (m / min) Adhesive strength (g / 15mm) 850 750 300 900 500 It is shown below. <Elastic modulus> According to ASTM-D790. <Density> According to ASTM-D792. <Adhesive strength> A sample having a molding speed of 100 m / min was used. Only in Comparative Example 2, the molding speed was 60 m / min.

A T-peel test was performed on the woven fabric and the coating layer on the laminate sheet cut to a width of 15 mm in the T direction. The peel rate was 300 mm / min. <Drawdown property during extrusion lamination (DD property)> When the extrusion rate is kept constant at 40 kg / hour and the line speed is gradually increased, molding can be performed without surging, ear breakage, or extreme uneven thickness phenomenon. The maximum speed that can be achieved is the drawdown property. <Xylene solubles> Measured according to the method described in FDA 177.1520 (d) (4) (ii).

[0021]

From the above Table 1, it can be seen that by coating a specific soft polypropylene resin on a woven fabric of a polyolefin resin such as polypropylene, which is lightweight and excellent in hygiene, it is flexible, excellent in heat resistance, and adheres to the woven fabric. It can be seen that a laminated sheet having excellent strength and excellent suitability for extrusion lamination can be obtained.

Claims (3)

[Claims] 1. A laminated laminate sheet having a coating layer on one or both sides of a woven fabric of a polyolefin resin, wherein the coating layer is made of a polypropylene resin composition having the following characteristics. . (1) 40-80% by weight of xylene solubles at 25 ° C
It is. (2) The melting peak measured by a differential scanning calorimeter is 13
At least one exists at each of 0 to 170 ° C and 100 to 120 ° C. 2. The laminated sheet according to claim 1, wherein the polyolefin resin is a polypropylene resin. 3. The polypropylene resin composition according to claim 1,
(A) The content of the ethylene-propylene elastomer and / or the ethylene-butene elastomer is 50 to 70% by weight.
The laminated laminate sheet according to claim 1, comprising 60 to 97% by weight of the multi-staged polypropylene copolymer, and (B) 40 to ³ % by weight of a low-density polyethylene having a density of 0.880 to 0.925 g / cm3.