JP2013163276A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film that can be subjected to a bag forming process by a heat fusion bonding method, is lightweight and solid, can be inexpensively manufactured, especially is effective as a substrate for a flexible container, or substrate for a waterproof sheet, and is well balanced in adhesiveness and heat resistance between layers.SOLUTION: A laminated film includes at least a polypropylene polymer, and has three layers comprising: a layer comprised of a resin composition whose melting point and flexural modulus are in specific ranges; a layer comprised of a base cloth; and a layer comprised of a resin composition including at least two specific propylene-ethylene copolymers.

Description

  The present invention relates to a laminated film excellent in interlayer adhesion, heat resistance, heat seal processability, and the like.

  Conventionally, as a laminated film in which a thermoplastic resin film is laminated on the surface of a woven fabric such as a flexible container, the surface of the woven fabric made of synthetic resin fibers such as polyester, polyamide, polyolefin, and vinylon, and other fibers is used. A bag made from a soft tarpaulin having a coating layer formed of polyvinyl chloride resin, rubber or the like as a base material has been used. The polyvinyl chloride resin used as the coating layer contains a large amount of plasticizer for the purpose of improving thermal stability, flexibility, etc., so the plasticizer elutes (bleeds out) and moves to the filler. In addition, the resin itself has a high specific gravity and inferior workability, and toxic hydrogen chloride gas is generated at the time of combustion.

  Therefore, ethylene-vinyl acetate copolymer has recently been used in place of polyvinyl chloride resin, but this resin is relatively lightweight and excellent in safety, but has excellent heat resistance, durability, and wear resistance. There are problems such as inferiority and odor.

  In addition, as a material that is easy to mold, lightweight, and inexpensive, a base material in which a low-density polyethylene resin is coated on the surface of a woven fabric made of polyolefin fibers such as polypropylene and high-density polyethylene has also been proposed. The strength of the base material is likely to decrease, and there are disadvantages such as the fusion strength and peel strength of the seal portion are not sufficiently developed.

  In view of this, the following are known as characteristic features of the resin of the coating layer. Specifically, (1) a tarpaulin in which an inorganic substance is mixed with an ethylene-vinyl acetate copolymer and bonded and integrated on both sides of a coarse base fabric, and (2) a mixture of the ethylene copolymer is bonded to the fabric. A tarpaulin, (3) a laminate sheet obtained by laminating an ethylene resin on a fabric made of drawn polyolefin resin yarn, and (4) a composition comprising an ethylene-α, β-unsaturated carboxylic acid ester copolymer and a tackifier. Laminate sheet coated on woven fabric made of drawn polyolefin yarn, (5) Raw material for flexible containers with ethylene-α-olefin copolymer coated on fiber base material, (6) Ethylene-vinyl acetate copolymer with olefin Tarpaulin in which a composition kneaded with a polymer is coated on a fabric, (7) A linear low-density polyethylene as a main component in a woven fabric made of synthetic resin flat yarn Polyethylene cross the like in which the resin coating.

  In addition, the following are known as characteristic of the texture of the woven fabric and the yarn used. Specifically, (8) a tarpaulin in which an ethylene-vinyl acetate copolymer is coated on a mesh fabric using a multifilament made of isotactic polypropylene, (9) polypropylene in the core layer, and high-density polyethylene in the outer layer. A flexible container base material in which a resin layer is laminated on a woven fabric composed of a multilayer tape, (10) a tarpaulin coated with an ethylene-vinyl acetate copolymer on a woven fabric composed of a polyolefin-based stretched yarn, and the like. It is done. In recent years, (11) as a flexible container woven fabric excellent in heat-resistant creep resistance, an ethylene-vinyl acetate resin laminated on a woven fabric made of mixed multifilaments of polypropylene multifilament and polyethylene multifilament (for example, patents) Document 1) is disclosed. Further, a laminated film laminated with a metallocene polyolefin (for example, Patent Document 2), a film using a lubricant to prevent inner surface blocking (for example, Patent Document 3), and the like are disclosed.

JP 07-054239 A JP 09-201924 A JP 2001-293831 A

  However, in any of the above methods, the interlayer adhesion, heat resistance, blocking properties of the inner layer of the film are insufficient, and the formation of the woven fabric, the covering method, the bag making method, etc. are complicated and the productivity is poor. Further improvements are desired. Furthermore, as in Patent Document 3, if a lubricant is used, there is a concern of shifting to the contents.

  The present invention eliminates the above-mentioned conventional drawbacks, enables bag-making by the heat seal method, is lightweight and robust, and can be manufactured at a low cost. An object of the present invention is to provide a laminated film that is particularly suitable as a material and has an excellent balance of adhesion between layers and heat resistance.

  As a result of extensive studies by the present inventors, it has been found that the above-mentioned problems can be solved by a laminated film of a base fabric and a specific resin composition, and the present invention has been completed. That is, the gist of the present invention resides in the following [1] to [5].

[1] A laminated film having at least three layers of the following A layer, B layer and C layer.
Layer A: Layer component (A-1) comprising at least the following component (A-1), and having a melting point of 145 ° C. or higher and 165 ° C. or lower and a flexural modulus of 30 to 500 MPa (A-1): melting point Polypropylene polymer B layer having a temperature of 150 ° C. or more and 170 ° C. or less: layer C comprising a base fabric: 10 to 90% by weight of the following component (C-1) and 90 to 10% by weight of the following component (C-2) Layer component (C-1) comprising the resin composition (2) containing:% of propylene unit content of more than 93% by weight and 99% by weight of the total content of propylene unit content and ethylene unit content Propylene-ethylene copolymer component (C-2) having a melt flow rate (measurement temperature 230 ° C., measurement load 21.18 N) of 0.1 to 50 g / 10 min: content of propylene unit and ethylene Unit content and Propylene-ethylene copolymer having a propylene unit content of 80 to 93% by weight and a melt flow rate (measuring temperature 230 ° C., measuring load 21.18 N) of 0.1 to 50 g / 10 min based on the total amount. Coalescence

[2] The resin composition (1) includes the component (A-1) and the following component (A-2), and the total amount of the component (A-1) and the component (A-2) is as follows. The laminated film according to [1], comprising 10% by weight to 90% by weight of the component (A-2).
Component (A-2): Olefin elastomer and / or styrene elastomer

[3] The resin composition (2) includes the following component (C-3), and the component (C-1), the component (C-2), and the component (C-3) with respect to the total amount of the component (C-3) 3) The laminated film according to [1] or [2], containing 5 to 70% by weight.
Component (C-3): Olefin-based elastomer and / or styrene-based elastomer

[4] The laminated film according to any one of [1] to [3], wherein the base fabric includes at least one of polyester fiber, polyamide fiber, and vinylon fiber.

[5] The laminated film according to any one of [1] to [4], wherein the melting point of the resin composition (1) is higher by 10 ° C. or more than the melting point of the resin composition (2). .

  ADVANTAGE OF THE INVENTION According to this invention, the laminated | multilayer film excellent in the adhesiveness between layers, heat resistance, heat seal workability, etc., the base material for flexible containers, and the base material for waterproof sheets consisting thereof are provided.

  The embodiments of the present invention will be described in detail below. However, the description of the constituent elements described below is an example of the embodiments of the present invention, and the present invention is described below unless the gist of the present invention is exceeded. It is not limited to. In the present specification, when a numerical value or physical value is inserted before and after using the expression “to”, it is used as an expression including the numerical value or physical value before and after that.

<Laminated film>
The laminated film of the present invention is characterized by having at least three layers of the following A layer, B layer and C layer.
Layer A: Layer component (A-1) comprising at least the following component (A-1), and having a melting point of 145 ° C. or higher and 165 ° C. or lower and a flexural modulus of 30 to 500 MPa (A-1): melting point Polypropylene polymer B layer having a temperature of 150 ° C. or more and 170 ° C. or less: layer C comprising a base fabric: 10 to 90% by weight of the following component (C-1) and 90 to 10% by weight of the following component (C-2) Layer component (C-1) comprising the resin composition (2) containing:% of propylene unit content of more than 93% by weight and 99% by weight of the total content of propylene unit content and ethylene unit content Propylene-ethylene copolymer component (C-2) having a melt flow rate (measurement temperature 230 ° C., measurement load 21.18 N) of 0.1 to 50 g / 10 min: content of propylene unit and ethylene Unit content and Propylene-ethylene copolymer having a propylene unit content of 80 to 93% by weight and a melt flow rate (measuring temperature 230 ° C., measuring load 21.18 N) of 0.1 to 50 g / 10 min based on the total amount. Coalescence

  The laminated film of the present invention uses a layer composed of the resin composition (1) having the above-described configuration having a high melting point as the A layer, and uses a layer composed of the resin composition (2) having the above configuration as the C layer. When heat sealing is performed with the A layer as an outer layer facing each other, the balance of the flexibility of the laminated film is good, and the layers to be bonded, that is, the A layer-B layer, B layer-C Peeling strength is high between each of the interlayers and between the C layers, and heat sealing can be performed between the C layers without the A layer being fused to the seal bar when heat sealing is performed.

For the above reasons, in the laminated film of the present invention, when heat sealing is performed in the above-described manner, the resin composition (1) of the A layer and the resin composition (2) of the C layer are combined with the resin composition (1 ) Is preferably a material having a higher melting point than the resin composition (2). More specifically, the resin composition (1) for the A layer and the resin composition (2) for the C layer The melting point difference is preferably 10 ° C. or more, more preferably 15 ° C. or more. Although there is no restriction | limiting in particular about the upper limit of the melting | fusing point difference of the resin composition (1) and resin composition (2) of A layer, In the resin composition (1) and resin composition (2) used for this invention Usually 50 ° C or lower. Resin composition (
The melting points of 1) and the resin composition (2) are both melting peak temperatures determined by differential scanning calorimetry (DSC) measurement.

  Each layer constituting the laminated film of the present invention will be described in detail below. The layer A, the layer B, and the layer C are included in this order, and other layers may be included as necessary. .

  The thickness of the A layer is usually 5 μm or more, preferably 10 μm or more, and is usually 300 μm or less, preferably 250 μm or less. Further, the thickness of the C layer is preferably 5 μm or more, more preferably 10 μm or more, and on the other hand, 300 μm or less is preferable, and more preferably 250 μm or less. It is preferable at the point of the intensity | strength of a multilayer film that thickness is more than the said lower limit. Moreover, it is preferable at the flexible point of a multilayer film that it is below the said upper limit.

1. A layer In the laminated film of the present invention, the A layer comprises the resin composition (1) containing at least the component (A-1), having a melting point of 145 ° C. or higher and 165 ° C. or lower and a flexural modulus of 30 to 500 MPa. Is a layer.

1-1. Resin composition (1)
The resin composition (1) satisfies the conditions of a melting point of 145 ° C. or more and 165 ° C. or less and a flexural modulus of 30 to 500 MPa. The resin composition (1) may be composed of the propylene polymer alone as the component (A-1) as long as the melting point and the flexural modulus satisfy these conditions.

  Melting | fusing point of the resin composition (1) of A layer is 145 degreeC or more, Preferably it is 150 degreeC or more, More preferably, it is 155 degreeC or more, More preferably, it is 160 degreeC or more. When the melting point of the resin composition (1) is not less than the above lower limit value, the A layer is excellent in heat resistance, and when the heat sealing process is performed in the above-described form, the A layer hardly adheres to the heat seal bar. Further, it is possible to give a feature that the heat seal processability is excellent. On the other hand, the melting point of the resin composition (1) is 165 ° C. or lower.

  In order to make the melting point of the resin composition (1) within the above range, in the polypropylene polymer of the component (A-1), the ratio of propylene units and the component (A-1) used for the resin composition (1) Control is possible by appropriately selecting the type and blending amount. Here, melting | fusing point of the resin composition (1) of A layer is melting | fusing point obtained by a differential scanning calorimeter (DSC) measurement.

  Further, the resin composition (1) of the A layer has a flexural modulus based on JIS K7203 in the range of 30 to 500 MPa, preferably 50 MPa or more, more preferably 100 MPa or more, on the other hand, preferably 450 MPa or less. More preferably, it is 400 MPa or less. When the flexural modulus of the resin composition (1) is not less than the above lower limit value, the outer layer A layer adheres to the seal bar when the laminated films are heat sealed with the A layer of the laminated film as the outer layer and the C layer as the inner layer. In addition, the surface of the laminated film can be prevented from being damaged by the pressure of the seal bar. Moreover, when the bending elastic modulus of a resin composition (1) is below the said upper limit, it can prevent that a crease and a pinhole generate | occur | produce in a laminated | multilayer film.

  In addition to the polypropylene polymer of the above component (A-1), by blending the olefin elastomer and / or styrene elastomer of the component (A-2) described later, flexibility and impact resistance are imparted and laminated. Since it becomes difficult to generate pinholes when the film is bent and the impact strength is increased, it is preferable for use as a base material for flexible containers or a base material for waterproof sheets. In order to improve these, it is preferable to blend the olefin elastomer and / or styrene elastomer of component (A-2).

1-2. Ingredient (A-1)
In the present invention, the propylene polymer of component (A-1) means one containing 90% by weight or more of propylene, and may be either a propylene homopolymer or a propylene-α-olefin copolymer. . These propylene polymers may be used alone or in combination of two or more different types.

  When the propylene-based polymer of the component (A-1) is a propylene-α-olefin copolymer, a known material can be used. For example, propylene random copolymers, propylene block copolymers, and mixtures thereof of propylene and one or more selected from the group consisting of ethylene and α-olefins other than propylene. Examples of the α-olefin (excluding propylene) include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1- Examples include α-olefins having 4 to 20 carbon atoms such as hexadecene, 1-octadecene, 1-eicosene and the like.

  These propylene polymers can be appropriately selected according to the use and purpose, but in the laminated film of the present invention, the melting point is high in order to obtain the heat resistance necessary for the resin composition (1) of the A layer. For this purpose, propylene homopolymers or propylene random copolymers with a higher propylene content are preferred. The content of propylene units is preferably 92 mol% or more, more preferably 95 mol% or more.

  The propylene polymer of the component (A-1) has a melting point (Tm) obtained by differential scanning calorimetry (DSC) measurement of 150 to 170 ° C, preferably 155 to 165 ° C. Further, the heat of fusion (ΔH) simultaneously analyzed by differential scanning calorimeter (DSC) measurement is usually 30 to 150 J / g, preferably 40 to 100 J / g, more preferably 50 to 80 J / g.

  The stereoregularity of the propylene-based polymer of the component (A-1) is not particularly limited, and for example, any of an isotactic structure, a syndiotactic structure, and the like can be used.

  Further, the melt flow rate (MFR) at a measurement temperature of 230 ° C. and a load of 21.18 N of the propylene-based polymer of the component (A-1) can be appropriately selected according to the purpose and use, but is usually 0.1 to 100 g. / 10 minutes. In order to adjust to such MFR value, it can be controlled by various reaction conditions such as reaction temperature, reaction pressure, reaction time, etc., or an organic peroxide is added to a propylene polymer having a low MFR, It is also possible to increase the MFR by melt mixing under.

  The catalyst used for obtaining the polypropylene polymer of component (A-1) is not particularly limited, and a known catalyst can be used. For example, a Ziegler-Natta catalyst formed by combining a titanium compound and an organic aluminum, a metallocene catalyst, or the like can be given.

  As the component (A-1) polypropylene polymer, commercially available products can be appropriately selected and used. Specific examples of commercially available products include Zelas (registered trademark) series manufactured by Mitsubishi Chemical Corporation, Novatec PP (registered trademark) series manufactured by Nippon Polypro.

1-3. Ingredient (A-2)
In order to impart flexibility to the A layer of the laminated film of the present invention, the resin composition (1) contains the following component (A-2) with respect to the total amount of the component (A-1) and the component (A-2). 10 to 90% by weight is preferable.
Component (A-2): Olefin elastomer and / or styrene elastomer

  In the present invention, the olefin elastomer in the component (A-2) is a copolymer of ethylene and α-olefin, and the amount of ethylene is 20% by weight with respect to the total amount of ethylene and α-olefin. That means the above.

  In order to further improve the flexibility of the film, the component (A-2) is more preferably at least 15% by weight, more preferably 20%, based on the total amount of the component (A-1) and the component (A-2). On the other hand, from the viewpoint of maintaining the strength of the film, it is more preferably 85% by weight or less, still more preferably 80% by weight or less.

  When an olefinic elastomer is used as the component (A-2), the olefinic elastomer is preferably contained in an amount of 20 to 90% by weight based on the total amount of the component (A-1) and the component (A-2). More preferably, it is contained at 80% by weight. Moreover, when using a styrene-type elastomer as a component (A-2), it is preferable that 10-70 weight% of styrene-type elastomers are included with respect to the total amount of a component (A-1) and a component (A-2). More preferably, it contains 15 to 60% by weight.

  In the olefin elastomer of component (A-2), comonomer copolymerized with ethylene includes α-olefins having 3 to 20 carbon atoms, specifically 1-octene, 1-pentene, 1-butene, 1- Propylene etc. are mentioned, These alpha-olefins do not need to be 1 type, and the mixture of 2 or more types of ethylene-alpha-olefin copolymer rubber may be sufficient. The content of α-olefin in the ethylene-α-olefin-based elastomer is 80% by weight or less, preferably 10 to 60% by weight, and more preferably 20 to 50% by weight.

  MFR (190 degreeC, 21.2N load) of the olefin type elastomer of a component (A-2) is 0.1-100 g / 10min normally, Preferably it is 0.5-50 g / 10min, More preferably, it is 0.5. ~ 30 g / 10 min.

Moreover, the density of the olefin type elastomer of a component (A-2) is 0.85-0.90 g / cm < ³ > normally, Preferably it is 0.86-0.88 g / cm < ³ >.

  The olefin elastomer of component (A-2) can be polymerized using a known titanium catalyst or metallocene catalyst.

  Moreover, the olefin type elastomer of a component (A-2) can also be obtained as a commercial item. Examples of commercially available products include Dow Chemical Co., Ltd., Engage (registered trademark) series, Mitsui Chemicals, Inc. Toughmer (registered trademark) series, and the like.

The styrene elastomer of component (A-2) is a styrene / conjugated diene block copolymer and / or a hydrogenated product thereof. The preferred conjugated diene in the styrene / conjugated diene block copolymer and / or its hydrogenated product is butadiene, isoprene or a mixture thereof. For example, a styrene-butadiene block copolymer (hereinafter sometimes simply referred to as “SBS”) and / or a hydrogenated product thereof (hereinafter simply referred to as “hydrogenated SBS”). Styrene / ethylene / butylene / styrene copolymer (SEBS) or hydrogenated styrene / isoprene block copolymer (hereinafter simply abbreviated as “hydrogenated S-I-S”). Styrene / ethylene / propylene / styrene copolymer (SEPS) and hydrogenated styrene / butadiene / isoprene block copolymer (hereinafter simply referred to as “hydrogenated S-BI-S”). ).

  The styrene content of the styrene / conjugated diene block copolymer and / or hydrogenated product thereof is not particularly limited, but is preferably 5% by weight or more, more preferably 8% by weight or more from the viewpoint of strength and heat resistance. More preferably, it is 10% by weight or more. The styrene content is preferably 50% by weight or less, more preferably 45% by weight or less, and still more preferably 40% by weight or less from the viewpoints of flexibility and impact resistance.

  The conjugated diene of the styrene / conjugated diene block copolymer and / or its hydrogenated product has a 1,2-microstructure analyzed by NMR method of preferably 60% or less, more preferably 45% or less. If the 1,2-microstructure is 60% or less, it tends to be good in terms of moldability and flexibility. From the viewpoint of weather resistance, the styrene elastomer of component (A-2) is preferably a hydrogenated product of styrene / conjugated diene block copolymer, and the hydrogenation rate is preferably 90% or more, and 95% or more. Is more preferable.

The weight ratio (isoprene / butadiene) when the conjugated diene in the styrene / conjugated diene block copolymer and / or its hydrogenated product is a mixture of isoprene and butadiene is generally 99/1 to 1/99, preferably 90/10. ~ 30/70, particularly preferably 80/2
0-40 / 60.

From the viewpoint of product gloss and mechanical strength, the weight average molecular weight of the hydrogenated styrene / conjugated diene block copolymer and / or the hydrogenated product thereof is preferably 50,000 or more, more preferably 80,000 or more. More preferably, it is 100,000 or more. The weight average molecular weight is preferably 1,000,000 or less, more preferably 800,000 or less, and still more preferably 500,000 or less, from the viewpoint of the appearance of the molded body.

  As a method for producing these styrene / conjugated diene block copolymers, for example, a styrene / conjugated diene block copolymer is produced in an inert solvent using a lithium catalyst by the method described in Japanese Patent Publication No. 40-23798. The styrene / conjugated diene block copolymer hydrogenated product may be synthesized as described above, and the styrene / conjugated diene block copolymer is synthesized as described above, and then, for example, Japanese Patent Publication No. 42-008704, Examples include the method of hydrogenation in the presence of a hydrogenation catalyst in an inert solvent by the methods described in JP-A-43-006636, JP-A-59-133203, and JP-A-60-079005. be able to. Hydrogenated S-BI-S is synthesized by, for example, a method described in JP-A-03-188114.

  The styrene / conjugated diene block copolymer and / or a hydrogenated product thereof can be obtained as a commercial product. Examples of the styrene / conjugated diene block copolymer include Clayton (registered trademark) D series manufactured by Kraton Polymer Co., Ltd. Examples of hydrogenated styrene / conjugated diene block copolymers include Clayton (registered trademark) G series manufactured by Kraton Polymer Co., Ltd., Septon (registered trademark) series manufactured by Kuraray Co., Ltd., and Tuftec (registered trademark) series manufactured by Asahi Kasei Corporation. Etc.

1-4. Other components Furthermore, in the resin composition (1) used for the A layer of the laminated film of the present invention, the effects of the present invention are not significantly impaired in addition to the above components (A-1) and (A-2). Within the range, the following additives and optional components such as resins other than the component (A-1) and the component (A-2) (hereinafter referred to as “other resins”) are blended depending on various purposes. Can do.

Additives include flame retardants, colorants, antioxidants, heat stabilizers, light stabilizers, UV absorbers, neutralizers, lubricants, anti-clouding agents, anti-blocking agents, slip agents, flame retardants, dispersants, Examples thereof include an antistatic agent, a conductivity imparting agent, a metal deactivator, a molecular weight adjusting agent, a fungicide, and a fluorescent brightening agent.

  Other resins include polyolefin resins other than the above-mentioned polyolefin resin components, polyester resins, polyamide resins, styrene resins, acrylic resins, polycarbonate resins, polyvinyl chloride resins and other thermoplastic resins, the above olefin elastomers, and styrene resins. Examples include elastomers other than elastomers. Other resins mentioned above may contain only one type or two or more types. The resin other than the component (A-1) and the component (A-2) is usually used in an amount of 15 parts by weight or less with respect to 100 parts by weight in total of the component (A-1) and the component (A-2). .

2. B layer B layer of the laminated | multilayer film of this invention is a layer which consists of base fabrics.

  The base fabric may be any of woven fabric, knitted fabric, and these resin-impregnated fabrics, and knitted fabric is particularly preferable.

  The fiber of the base fabric of the B layer may be woven with any of synthetic fibers, naturally derived fibers, semi-synthetic fibers, inorganic fibers, or mixed fibers composed of two or more of these. Specifically, synthetic fibers such as vinylon fibers, polyester fibers, nylon fibers, aromatic polyamide fibers, acrylic fibers; natural fibers such as cotton, cotton, rayon, hemp; glass fibers, silica fibers, alumina fibers, carbon Inorganic fibers such as fibers can be mentioned, but in consideration of processability and versatility, synthetic fibers are preferable, and in particular, a laminated film from which polyester fibers, polyamide fibers, and vinylon fibers can be obtained is preferable because the heat resistance strength is increased. The base fabric fibers mentioned above may be used alone or in combination of two or more. These fibers can be used in any shape such as multifilament yarns, short fiber spun yarns, monofilament yarns, split yarns, tape yarns, etc. The fiber yarns used in the present invention are multifilament yarns, short yarns, etc. A fiber spun yarn is preferable because of excellent strength and dimensional stability of the base fabric.

  The fiber diameter of the base fabric is usually preferably from 139 to 2222 dtex (125 to 2000 denier), particularly preferably from 278 to 1111 dtex (250 to 1000 denier).

When the base fabric used for the B layer is a knitted fabric, the mesh is preferably 0.5 to 20 mm, more preferably 1 to 15 mm. When the mesh of the base fabric is not less than the above lower limit value, the laminate strength of the thermoplastic resin film tends to be high, and when it is not more than the above upper limit value, the heat resistance of the laminated film tends to be improved.

  A commercially available product can be used as it is as the base fabric used for the B layer. Commercial products are available from, for example, Toyobo Co., Ltd., Toray Industries, Inc., Asahi Kasei Chemicals Corporation, and the like.

3. C layer In the laminated film of the present invention, the C layer is a layer comprising the resin composition (2) containing 10 to 90% by weight of the component (C-1) and 90 to 10% by weight of the component (C-2). is there. In the resin composition (2), the component (C-1) is a component that imparts strength to the material and suppresses stickiness, and the component (C-2) is a component that lowers the melting point and imparts flexibility. By blending these components within the above composition range, a material that is flexible, has a low melting point, and is less sticky can be obtained. Therefore, the molding processability is excellent and the effect of easy heat sealing can be obtained.

3-1. Resin composition (2)
The resin composition (2) constituting the C layer preferably contains 20 to 80% by weight of the component (C-1) with respect to the total amount of the component (C-1) and the component (C-2). More preferably, the component (C-2) is contained in an amount of 80 to 20% by weight. When the blending amount of the component (C-1) and the component (C-2) is in the above range, the heat sealability is improved.

  The melting point of the resin composition (2) is preferably 100 ° C. or higher, more preferably 110 ° C. or higher, and further preferably 120 ° C. or higher. When the melting point of the resin composition (2) is equal to or higher than the above lower limit, when the laminated film is heat-sealed in the above-described form with the A layer as the outer layer and the C layer as the inner layer, the C layer is formed on the heat seal bar. Can be imparted with the feature that it is difficult to adhere and heat seal processability is excellent. On the other hand, the melting point of the resin composition (2) is usually 160 ° C. or lower, but it is preferably 150 ° C. or lower because the melting point is preferably lower than the resin composition (1) of the A layer for the reasons described above. The temperature is preferably 140 ° C. or lower.

  In order to set the melting point of the resin composition (2) within the above range, the propylene content, the ethylene content and the component (C-) of the components (C-1) and (C-2) used in the resin composition (2) are used. It can be controlled by appropriately selecting the blending ratio of 1) and (C-2). Here, melting | fusing point of the resin composition (2) of C layer is melting | fusing point obtained by a differential scanning calorimeter (DSC) measurement.

  The resin composition (2) preferably has high flexibility. Specifically, at least one of the range of the flexural modulus based on JIS K7203 and the range of the duro A hardness based on JIS K7203 is in the following range. It is preferable.

  The flexural modulus of the resin composition (2) is preferably 400 MPa or less, more preferably 300 MPa or less. Although it does not restrict | limit about the minimum of a bending elastic modulus, it is 40 Mpa. For those having a flexural modulus of less than 40 MPa, the following Duro A hardness values are adopted.

  The duro A hardness of the resin composition (2) is not particularly limited, but is preferably 30 or more from the viewpoint of ensuring molding processability. On the other hand, although the upper limit of the durometer A hardness is not limited, the value of the flexural modulus is adopted for those having a durometer A hardness of 90 or more.

3-2. Ingredient (C-1)
Component (C-1) has a propylene unit content of more than 93% by weight and not more than 99% by weight with respect to the total amount of propylene unit content and ethylene unit content, and ethylene unit content. Is a propylene-ethylene copolymer having a melt flow rate (measurement temperature 230 ° C., measurement load 21.18 N) of 0.1 to 50 g / 10 min.

  When the resin composition (2) of the C layer contains the component (C-1) in the above range, mechanical strength is imparted to the C layer. In addition, the content of the propylene unit and the content of the ethylene unit in the polypropylene-ethylene copolymer of the component (C-1) can be obtained by infrared spectroscopy.

  The propylene-ethylene copolymer of component (C-1) has a measurement temperature of 230 ° C. and a measurement load of 21.18 N and a melt flow rate (MFR) of 0.1 g / 10 minutes, preferably 0.5 g / 10. On the other hand, it is preferably 50 g / 10 min or less, preferably 30 g / 10 min or less. When the MFR of the component (C-1) is not less than the above lower limit value, it is preferable from the viewpoint of mechanical strength, and when it is not more than the above upper limit value, it is preferable from the viewpoint of film appearance.

  As the propylene-ethylene copolymer of component (C-1), a known polypropylene material can be used, for example, one or two selected from the group consisting of propylene and ethylene or α-olefin (excluding propylene). These are propylene random copolymers, propylene block copolymers, and mixtures thereof. As the α-olefin (excluding propylene), 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene , 1-octadecene, 1-eicosene and the like, such as α-olefin having 4 to 20 carbon atoms.

  The catalyst used for obtaining the propylene-ethylene copolymer of component (C-1) is not particularly limited, and a known catalyst can be used. For example, a Ziegler-Natta catalyst formed by combining a titanium compound and an organic aluminum, a metallocene catalyst, or the like can be given.

  As the component (C-1) propylene-ethylene copolymer, commercially available products can be appropriately selected and used. Specific examples of commercially available products can be selected and used from Wintec (registered trademark) series, Novatec PP (registered trademark), etc., manufactured by Nippon Polypro.

3-3. Ingredient (C-2)
Component (C-2) has a propylene unit content of 80 to 93% by weight and an ethylene unit content of 20 to 7% by weight relative to the total content of propylene units and ethylene units. Yes, a propylene-ethylene copolymer having a melt flow rate (measuring temperature 230 ° C., measuring load 21.18 N) of 0.1 to 50 g / 10 min.

  The content of propylene units is 80% by weight or more, preferably 82% by weight, based on the total content of propylene units and ethylene units in the propylene-ethylene copolymer of component (C-2). On the other hand, the content of propylene units is 93 parts by weight or less, preferably 90% by weight or less. When the content of the propylene unit is not less than the above lower limit value, poor fusion due to blocking is reduced, and when the content is not more than the above upper limit value, the heat sealability of the laminated film becomes good.

  The content of the ethylene unit is 7% by weight or more, preferably 10% by weight, based on the total amount of the propylene unit content and the ethylene unit content of the propylene-ethylene copolymer of the component (C-2). Above, more preferably 12% by weight or more, on the other hand, 20% by weight or less, preferably 18% by weight or less. When the content of the ethylene unit is not less than the above lower limit value, the heat sealability of the laminated film becomes good, and when it is not more than the above upper limit value, poor fusion due to blocking is reduced. In addition, the content of the propylene unit and the content of the ethylene unit in the polypropylene-ethylene copolymer of the component (C-2) can be obtained by infrared spectroscopy.

  The propylene-ethylene copolymer of component (C-2) has a melt flow rate (MFR) at a temperature of 230 ° C. and a measurement load of 21.18 N of 0.1 g / 10 min or more, more preferably 2 g / 10 min. It is above, More preferably, it is 5 g / 10min or more. On the other hand, MFR is 50 g / 10 min or less, preferably 40 g / 10 min or less, more preferably 30 g / 10 min or less, and further preferably 20 g / 10 min or less. When the melt flow rate of the polypropylene-ethylene copolymer of the component (C-2) is not less than the lower limit, the molded appearance is good, and when it is not more than the upper limit, the mechanical strength is good. The melt flow rate is measured according to JIS K7210 under the conditions of a measurement temperature of 230 ° C. and a measurement load of 21.18N.

Propylene component (C-2) - the density of the ethylene copolymer is usually at 0.890 g / cm ³ or less, preferably 0.885 g / cm ³ or less, more preferably 0.880 g / cm ³ or less More preferably, it is 0.875 g / cm ³ or less. When the density of the polypropylene-ethylene copolymer of the component (C-2) is not more than the above upper limit value, the low-temperature impact resistance of the molded product tends to be good. Further, the lower limit of the density of the propylene-ethylene copolymer of component (C-2) is not particularly limited, but is usually 0.850 g / cm ³ or more, preferably 0.855 g / cm ³ or more, Preferably it is 0.860 g / cm ³ or more.

  As a method for producing the propylene-ethylene copolymer of component (C-2), for example, a slurry polymerization method using a nonmetallocene complex catalyst such as a heteroaryl ligand catalyst described in JP-T-2005-508416, Examples include a solution polymerization method, a bulk polymerization method, and a gas phase polymerization method. Moreover, it is also possible to appropriately select and use appropriate products from commercially available products such as Versify (registered trademark) series manufactured by Dow Chemical Co., Ltd. and Welnex (registered trademark) series manufactured by Nippon Polypro.

3-4. Ingredient (C-3)
The resin composition (2) constituting the C layer of the laminated film of the present invention includes the following component (C-3), and the component (C-1), the component (C-2) and the component (C-3). In order to give a softness | flexibility to a laminated | multilayer film, it is preferable that the following component (C-3) is included 5 to 70weight% with respect to the total amount. In order to further improve the softening effect, the component (C-3) is more preferably 10 relative to the total amount of the component (C-1), the component (C-2) and the component (C-3). ~ 60% by weight.
Component (C-3): Olefin-based elastomer and / or styrene-based elastomer

  The olefin elastomer in the component (C-3) is a copolymer of ethylene and α-olefin, and contains more than 20 wt% and less than 80 wt% of ethylene with respect to the total amount of ethylene and α-olefin. Is.

  In the olefin elastomer of component (C-3), comonomer copolymerized with ethylene includes α-olefins having 3 to 20 carbon atoms, specifically 1-octene, 1-pentene, 1-butene, 1- Propylene etc. are mentioned, These alpha-olefins do not need to be 1 type, and the mixture of 2 or more types of ethylene-alpha-olefin copolymer rubber may be sufficient. The content of α-olefin in the ethylene-α-olefin-based elastomer is 80% by weight or less, preferably 10 to 60% by weight, and more preferably 20 to 50% by weight.

  MFR (190 degreeC, 21.2N load) of the olefin type elastomer of a component (C-3) is 0.1-100 g / 10min normally, Preferably it is 0.5-50 g / 10min, More preferably, it is 0.5. ~ 30 g / 10 min.

Moreover, the density of the olefin elastomer of a component (C-3) is 0.85-0.90 g / cm < ³ > normally, Preferably it is 0.86-0.88 g / cm < ³ >.

  The olefin elastomer of component (C-3) can be polymerized using a known titanium catalyst or metallocene catalyst.

  Moreover, the olefin type elastomer of a component (C-3) can also be obtained as a commercial item. Applicable commercial products can be appropriately selected from the Dow Chemical Co., Ltd. Engage (registered trademark) series, Mitsui Chemicals, Inc. Toughmer (registered trademark) series, and the like.

  As the styrene elastomer in the component (C-3), the same styrene elastomer as the component (A-2) described above can be used.

  Although the compounding quantity of a component (C-3) is as above-mentioned, especially when using an olefin type elastomer as a component (C-3), a component (C-1), a component (C-2), and a component ( The total amount of C-3) is preferably 20% by weight or more, more preferably 25% by weight or more, more preferably 70% by weight or less, and more preferably 65% by weight or less. Moreover, when using a styrene-type elastomer as a component (C-3), a styrene-type elastomer is 10 weight% with respect to the total amount of a component (C-1), a component (C-2), and a component (C-3). The above is preferable, 15% by weight or more is more preferable, while 70% by weight or less is preferable, and 65% by weight or less is more preferable.

3-4. Other components In addition to the component (C-1), component (C-2), and component (C-3), the resin composition (2) used for the C layer of the laminated film of the present invention has the effects of the present invention. The following additives and other optional components such as other resins can be blended in accordance with various purposes.

  Additives include flame retardants, colorants, antioxidants, heat stabilizers, light stabilizers, UV absorbers, neutralizers, lubricants, anti-clouding agents, anti-blocking agents, slip agents, flame retardants, dispersants, Examples thereof include an antistatic agent, a conductivity imparting agent, a metal deactivator, a molecular weight adjusting agent, a fungicide, and a fluorescent brightening agent.

  Other resins include polyolefin resin, polyester resin, polyamide resin, styrene resin, acrylic resin, polycarbonate resin, polychlorinated resin other than the components (C-1), (C-2) and (C-3). Examples thereof include thermoplastic resins such as vinyl resins, and elastomers other than the olefin elastomers and styrene elastomers. Other resins mentioned above may contain only one type or two or more types. The resin other than the component (C-1), the component (C-2) and the component (C-3) is usually used in an amount of 15 parts by weight or less with respect to 100 parts by weight of the total.

<Other layers>
The laminated film of the present invention may have a barrier layer, an antistatic layer, a flame retardant layer, and the like as long as the effects of the present invention are not significantly impaired.

<Method for producing laminated film>
The method of the manufacturing method is not limited as long as it can be formed into a laminated film. For example, the A layer and the C layer are each formed in advance by a T-die forming method, an inflation forming method, a calendar forming method, etc., and the B layer is sandwiched between them. The method of manufacturing by using a heat roll etc. and laminating by laminating, the resin composition (1) of the A layer melted directly on the base fabric of the B layer, and the resin composition (2) of the C layer And the like, and the like.

<Application>
The laminated film of the present invention is cut into various shapes and heat-sealed by a hot air heat sealing device, thereby allowing a flexible container base material used for a flexible container bag for transporting grains, feed, resin pellets, and the like, It can be used after being processed into a waterproof sheet base material for the purpose of protecting waterproofing equipment and construction equipment.

EXAMPLES Hereinafter, although this invention is demonstrated still in detail using an Example, this invention is not limited by a following example, unless the summary is exceeded. The values of various production conditions and evaluation results in the following examples have meanings as preferred values of the upper limit or lower limit in the embodiment of the present invention, and the preferred range is the upper limit or lower limit described above. It may be a range defined by a combination of a value and a value in the following example or a value between examples.

[material]
In the examples and comparative examples described later, the following raw materials were used.
<Polypropylene polymer>
Polypropylene polymer 1: Novatec PP (registered trademark) MA8 (MFR: 0.8, ethylene content: 0% by weight, propylene content: 100% by weight, density: 0.90 g / cm ³ ), manufactured by Nippon Polypro Co., Ltd .: 162 ° C (measured with DSC)
Polypropylene polymer 2: Wintec (registered trademark) WFX4T (MFR: 7, ethylene content: 3% by weight, propylene content 97% by weight, density: 0.90, manufactured by Nippon Polypro Co., Ltd.
g / cm ³ )
Polypropylene polymer 3: Versify (registered trademark) 2300 manufactured by Dow Chemical Company (MFR: 2, ethylene content: 14% by weight, propylene content: 86% by weight, density: 0.8)
7 g / cm ³ )

  In addition, the propylene content and ethylene content in said polypropylene polymers 1-3 were calculated | required by the infrared spectroscopy (FT / IR-60 by JASCO). The melt flow rate (MFR, unit: g / 10 minutes) was measured under the conditions of a measurement temperature of 230 ° C. and a measurement load of 21.18 N according to JIS K7210.

<Olefin-based elastomer>
Olefin-based elastomer: DuPont Chemical Engage (registered trademark) 8100 (MFR: 2, ethylene content: 60% by weight, octene content: 40% by weight, density: 0.87 g /
cm ³ )

  The ethylene content and the octene content were determined by infrared spectroscopy (FT / IR-60 manufactured by JASCO). The melt flow rate (MFR, unit: g / 10 minutes) was measured under the conditions of a measurement temperature of 190 ° C. and a measurement load of 21.18 N according to JIS K7210.

<Styrene elastomer>
Styrenic elastomer: KRATON (registered trademark) G1645MO manufactured by Kraton (hydrogenated product of styrene-butadiene block copolymer, with a hydrogenation rate of 98% or more)

<Base fabric>
Base fabric 1: Commercial polyester fiber knitted fabric (resin impregnation, mesh: 1 mm square)
Base fabric 2: commercially available knitted fabric of vinylon fiber (mesh: 1 mm square)

[Evaluation method of resin composition and laminated film]
The laminated films produced in Examples 1 and 2 and Comparative Examples 1 to 4 described below were evaluated as described in each of the following 1) to 4).

1) Interlayer adhesion / heat resistance: delamination test A sample of a laminated film was cut into a width of 10 mm and used for an delamination test. In the delamination test, a precision universal testing machine (Autograph (registered trademark) AG2000 manufactured by Shimadzu Corporation) was used.
-Laminating interlayer strength An interlayer peeling test was performed at a speed of 200 mm / min in an atmosphere of 23 ° C. The peel strength in an atmosphere at 23 ° C. was defined as “laminate strength”. The higher the value of the laminate strength, the better the adhesion between the layers, and 10N / 10 mm or more was evaluated as acceptable.
-Film heat-resistant strength The delamination test was implemented in the 85 degreeC atmosphere at the speed of 200 mm / min. The peel strength in an 85 ° C. atmosphere was defined as “film heat resistant strength”. The higher the value of the film heat resistance strength, the better the heat resistance, and 30 N / 10 mm or more was evaluated as acceptable.

2) Heat seal processability: Fusing test to seal bar The heat seal tester (manufactured by Sagawa Seisakusho Co., Ltd.) adjusted the temperature to a certain temperature by matching the two laminated films so that the C layer surfaces overlap each other. Place between the seal bars, seal under the conditions of pressure 0.29 MPa and time 2 seconds, and evaluate the fusion to the seal bar in the following two stages under the seal bar temperature conditions when the seal strength is 20 N / 10 mm or more I went there.
○: The laminated film was not fused to the seal bar during heat sealing, and the heat sealing processability was good.
X: The laminated film was fused to the seal bar during heat sealing.

3) Flexural modulus (unit: MPa)
Each of the following resin compositions 1 and 2 was measured in accordance with JIS K7203 under the conditions of a span interval of 64 mm and a bending speed of 1 mm / min.

4) Melting point About each of the following resin compositions 1 and 2, using a differential scanning calorimeter (DSC), it heated up from 40 degreeC to 200 degreeC with the temperature increase rate of 100 degree-C / min, and hold | maintained for 3 minutes, and then 40 After cooling to 10 ° C. at a cooling rate of 10 ° C./min, the temperature of the melting peak when the temperature was raised again to 200 ° C. at a heating rate of 10 ° C./min was determined.

[Production of Resin Compositions 1 and 2]
Each raw material was melt-kneaded at a set temperature of 200 ° C. by a twin screw extruder (“TEX-30αII” manufactured by Nippon Steel Works, Ltd., cylinder diameter 30 mm) based on the blending ratio (parts by weight) shown in Table-1. The pellets of the resin compositions 1 and 2 used for the A layer and / or the C layer were obtained.

  Using the above resin composition, single-layer films each having a thickness of 100 μm were obtained using a T-die molding machine manufactured by GSI Creos. The molding conditions were set to a molding temperature of 210 ° C. and a molding speed of 10 m / min.

<Example 1>
The single-layer films of the resin compositions 1 and 2 obtained above were each cut to A4 size, overlapped so that the base fabric was sandwiched between the resin composition 1 and the resin composition 2, and then heated to 170 ° C. A laminated film was obtained by laminating with two rolls. About the obtained laminated | multilayer film, said delamination test was implemented and laminate strength and film heat resistant strength were evaluated. The results are shown in Table-2.

<Examples 2 to 6>
Evaluation was performed in the same manner as in Example 1 except that the layer structure of the laminated film was as shown in Table-2. The evaluation results are shown in Table-2.

[Evaluation of results]
The laminated films of Examples 1 and 2 were all excellent in interlayer adhesion, heat resistance, and heat seal processability. On the other hand, the laminated films of Comparative Examples 1 and 3 were inferior in interlayer adhesion, and the laminated films of Comparative Examples 2 and 4 were poor in heat seal processability.

  The laminated film of the present invention is excellent in interlayer adhesion, heat resistance, heat seal processability, and the like. In particular, it can be suitably used for applications such as a base material for flexible containers used for flexible container bags and a base material for waterproof sheets for the purpose of protecting water-stopping / construction equipment.

Claims (5)

A laminated film having at least three layers of the following A layer, B layer and C layer.
Layer A: Layer component (A-1) comprising at least the following component (A-1), and having a melting point of 145 ° C. or higher and 165 ° C. or lower and a flexural modulus of 30 to 500 MPa (A-1): melting point Polypropylene polymer B layer having a temperature of 150 ° C. or more and 170 ° C. or less: layer C comprising a base fabric: 10 to 90% by weight of the following component (C-1) and 90 to 10% by weight of the following component (C-2) Layer component (C-1) comprising the resin composition (2) containing:% of propylene unit content of more than 93% by weight and 99% by weight of the total content of propylene unit content and ethylene unit content Propylene-ethylene copolymer component (C-2) having a melt flow rate (measurement temperature 230 ° C., measurement load 21.18 N) of 0.1 to 50 g / 10 min: content of propylene unit and ethylene Unit content and Propylene-ethylene copolymer having a propylene unit content of 80 to 93% by weight and a melt flow rate (measuring temperature 230 ° C., measuring load 21.18 N) of 0.1 to 50 g / 10 min based on the total amount. Coalescence The resin composition (1) includes the component (A-1) and the following component (A-2), and the component (A
The laminated film of Claim 1 which contains the following component (A-2) 10weight% or more and 90 weight% or less with respect to the total amount of -1) and a component (A-2).
Component (A-2): Olefin elastomer and / or styrene elastomer The resin composition (2) includes the following component (C-3), and the component (C-3) with respect to the total amount of the component (C-1), the component (C-2) and the component (C-3) The laminated film according to claim 1 or 2, comprising 5 to 70% by weight.
Component (C-3): Olefin-based elastomer and / or styrene-based elastomer   The laminated film according to any one of claims 1 to 3, wherein the base fabric includes at least one of polyester fiber, polyamide fiber, and vinylon fiber.   The laminated film according to any one of claims 1 to 4, wherein a melting point of the resin composition (1) is higher by 10 ° C or more than a melting point of the resin composition (2).