JP2021195481A - Polyolefin-based resin film, adhesive film, decorative film, and decorative adhesive film - Google Patents

Abstract

To provide a film which solves problems in rigidity, workability and handleability of the film.SOLUTION: A polyolefin-based resin film is a film formed of a resin composition containing a polyolefin-based resin and a nucleating agent, in which both of tensile elastic moduli before and after heating at 110°C for 60 minutes are within a range of 1,000 to 1,500 MPa, and tensile elongation at break after heating at 110°C for 60 minutes shows 100% or more.

Description

The present invention relates to an adhesive film (tape) used in a semiconductor manufacturing process, a cosmetic adhesive film (tape) such as a sticker, a label, a marking film, etc., which is attached to give a design to a signboard, an automobile, or the like. The present invention relates to a polyolefin-based resin film preferably used as a base material for a sheet or the like, an adhesive film in which an adhesive layer is laminated on the film, and a decorative film in which a printing layer is laminated.

Conventionally, cosmetic adhesive films (tapes) such as stickers, labels and marking films, which are conventionally attached to adhesive films (tapes), signs, automobiles, etc. to give them design, and decorative sheets, etc., are colored and processed. A film made of a polyvinyl chloride resin (hereinafter, also referred to as "PVC-based film") having excellent properties, scratch resistance, weather resistance and the like is often used as a base material.

The PVC-based film has rigidity by itself, but a plasticizer is added for the purpose of imparting flexibility so that it can function as an adhesive film. However, depending on the plasticizer used, there are problems that the compatibility with the pressure-sensitive adhesive is poor, the stability is poor when the pressure-sensitive adhesive film is used, and the bleed-out of the plasticizer becomes remarkable. There is also a tendency for regulations to be tightened on the use of plasticizers themselves.

Therefore, a polyolefin-based resin film has been widely used as a material in place of the PVC-based film.
Decorative films for interior and exterior of buildings using polyolefin resin film as a base material, marking films for interior and exterior of automobiles, etc. are known. Film technology and the like are disclosed.
The films using general polyolefin resins such as polypropylene and polyethylene described in these documents have an elastic modulus of 1000 MPa or less in order to improve workability, and are used for applications requiring high rigidity. Is not suitable.

Further, a technique relating to a film having a polyolefin resin and a nucleating agent is also disclosed (Patent Document 3).
However, in the technique described in Patent Document 3, although a nucleating agent is used, a highly flexible material having low crystallinity is often used, and it is presumed that the rigidity is inferior.

A patent relating to a film containing a nucleating agent and having high rigidity is also disclosed (Patent Document 4).
However, in the technique described in Patent Document 4, although a highly rigid film is obtained, the film is broken when the film is conveyed in the process of applying the print layer or the adhesive layer, which is the processability and handleability. The problem was not fully considered, and there was room for improvement in workability and handleability.

Therefore, it is considered that there is still room for improvement in providing a film that solves these problems such as film rigidity, processability, and handleability.

Japanese Unexamined Patent Publication No. 10-36590 Japanese Unexamined Patent Publication No. 11-172017 Japanese Unexamined Patent Publication No. 2018-39915 Japanese Patent No. 6386874

In view of such conventional problems, it is an object of the present invention to provide a polyolefin-based resin film having excellent film rigidity, processability, and handleability.

The present inventors have diligently studied a film made of a polyolefin-based resin having excellent film rigidity, processability, and handleability, and found that a film made of the resin composition of the present invention can be used to achieve these. The present invention was completed. It is also possible to obtain an adhesive film, a decorative film, or a cosmetic adhesive film by laminating an adhesive layer or a printing layer on the film, and these films can also be used for interior / exterior buildings, automobile interiors / exteriors, and automobile cosmetics. It can be suitably used.

That is, the gist of the present invention is as follows.
[1]
A film composed of a resin composition containing a polyolefin resin and a nucleating agent, the tensile elastic modulus before and after heating at 110 ° C. for 60 minutes is in the range of 1000 to 1500 MPa, and at 110 ° C. A polyolefin-based resin film having a tensile modulus at break of 100% or more after heating for 60 minutes.
[2]
The polyolefin-based resin film according to [1], which contains at least one selected from the group consisting of polyethylene-based resins, random polypropylenes, and olefin-based elastomers as the polyolefin-based resin, and also contains homopolypropylene. ..
[3]
The polyolefin according to [1] or [2], wherein the content of homopolypropylene is in the range of 70.0 to 95.0% by mass when the total weight of the polyolefin resin is 100% by mass. Polyolefin film.
[4]
The polyolefin-based resin film according to any one of [1] to [3], which contains 0.1 to 0.28 parts by mass of a nucleating agent with respect to 100 parts by mass of the polyolefin-based resin.
[5]
The polyolefin-based resin film according to any one of [1] to [4], which is composed of at least two or more layers, that is, an outer layer that does not contain a nucleating agent and a layer that contains a nucleating agent.
[6]
An adhesive film obtained by laminating an adhesive layer on at least one surface of the polyolefin-based resin film according to any one of [1] to [5].
[7]
A decorative film obtained by laminating a printing layer on at least one side of the polyolefin-based resin film according to any one of [1] to [5].
[8]
A cosmetic adhesive film obtained by further laminating an adhesive layer on the print layer side of the decorative film according to [7].

By using the polyolefin-based resin film of the present invention, a film having excellent rigidity, processability, and handleability can be obtained. It is also possible to obtain an adhesive film, a decorative film or a cosmetic adhesive film by laminating an adhesive layer or a printing layer on the film, and these films can also be used for interior / exterior buildings, interior / exterior automobiles and their cosmetic applications. Can be suitably used

The present invention will be described in detail below, but the present invention is not limited to the following embodiments, and can be variously modified and carried out within the scope of the gist thereof. In addition, when the expression "~" is used in this specification, it shall be used as an expression including numerical values or physical property values before and after the expression.

The present invention is a film made of a resin composition containing a polyolefin-based resin and a nucleating agent, and the tensile elastic modulus before and after heating at 110 ° C. for 60 minutes is in the range of 1000 to 1500 MPa. The present invention relates to a polyolefin-based resin film having a tensile modulus at break of 100% or more after heating at 110 ° C. for 60 minutes (hereinafter, also referred to as “polyolefin-based resin of the present invention”).

<Polyolefin resin>
The resin composition used for producing the polyolefin-based resin film of the present invention contains a polyolefin-based resin as an essential component. Polyolefin-based resins are preferably used from the viewpoints of easy availability, flexibility, handleability, economy, and having an appropriate melting point.
Examples of the polyolefin-based resin include polyethylene-based resin, polypropylene-based resin, olefin-based elastomer, and cyclic olefin-based resin.
Among the polyolefin-based resins, polyethylene-based resins, polypropylene-based resins, and olefin-based elastomers are preferable from the viewpoint of easy availability and imparting flexibility to the obtained film.

Examples of the polyethylene-based resin include homopolymers of ethylene, copolymers of ethylene containing ethylene as a main component and other monomers copolymerizable (low density polyethylene (LDPE), high pressure method low density polyethylene, and the like. Linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), ethylene-based copolymer (metallocene-based polyethylene) obtained by polymerization using a metallocene-based catalyst, ethylene-vinyl acetate copolymer, ethylene- (meth). ) Methyl acrylate copolymer, ethylene- (meth) ethyl acrylate copolymer, ethylene- (meth) butyl acrylate copolymer, ethylene- (meth) acrylate copolymer, ethylene- (meth) acrylate copolymer Examples thereof include a metal ion cross-linking resin (ionomer) of a polymer.
Among them, low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) are preferably used from the viewpoint of easy availability, handleability of the resin, and imparting flexibility to the obtained film.

Examples of the polypropylene-based resin include a homopolymer of propylene (homopolypropylene), a copolymer of propylene containing propylene as a main component and another monomer copolymerizable with the copolymer, and a mixture thereof.
Examples of the copolymer of propylene containing propylene as a main component and a copolymerizable other monomer include a random copolymer (random polypropylene) of propylene and ethylene or another α-olefin, or a block copolymer. (Block polypropylene), a block copolymer containing a rubber component, a graft copolymer and the like can be mentioned.

The α-olefin used as the other monomer copolymerizable with propylene is preferably one having 4 to 12 carbon atoms, and for example, 1-butene, 1-pentene, 1-hexene, 1-hexene. , 1-octene, 4-methyl-1-pentene, 1-decene and the like, and one or a mixture of two or more thereof is used.

The olefin-based elastomer is a soft resin containing a polyolefin-based resin and a rubber component, and the rubber component may be dispersed in the polyolefin-based resin or may be copolymerized with each other.
Specific examples of the olefin-based elastomer include ethylene-propylene copolymer elastomer, ethylene-1-butene copolymer elastomer, ethylene-propylene-1-butene copolymer elastomer, and ethylene-1-hexene copolymer elastomer. , Ethylene-1-octene copolymer elastomer, ethylene-styrene copolymer elastomer, ethylene-norbornen copolymer elastomer, propylene-1-butene copolymer elastomer, ethylene-propylene-non-conjugated diene copolymer elastomer, ethylene Atypical elastic copolymers mainly composed of olefins such as -1-butene-non-conjugated diene copolymer elastomer and ethylene-propylene-1-butene-non-conjugated diene copolymer elastomer, derivatives thereof and acid modification. Derivatives and the like can be mentioned.

The melt flow rate of the above-mentioned polyethylene-based resin, polypropylene-based resin, olefin-based elastomer, etc. is appropriately selected depending on the molding method and application to which it is applied, but is measured under a temperature condition of 190 ° C. or 230 ° C. under a load of 2.16 kg. The value is preferably 0.1 to 50 g / 10 minutes. If it is 0.5 g / 10 minutes or more, the formability of the film becomes good, and if it is 50 g / 10 minutes or less, the thickness accuracy of the film can be kept good. It is more preferably 0.5 to 40 g / 10 minutes, still more preferably 1.0 to 30 g / 10 minutes.

The melting point of the polyethylene resin, polypropylene resin, olefin elastomer or the like is preferably in the range of 70 ° C. or higher and 170 ° C. or lower as a value measured by differential scanning calorimetry. Having a melting point in the range of 70 ° C. or higher and 170 ° C. or lower makes it possible to improve the processability of the obtained film at a temperature of 200 ° C. or lower.
Here, as a condition for measuring the differential scanning calorimetry, the temperature is usually raised from 25 ° C. to 250 ° C. at a heating rate of 10 ° C./min, then lowered to 25 ° C. at a cooling rate of 10 ° C./min, and then raised again. The temperature is raised to 250 ° C. at a speed of 10 ° C./min.

Regarding the strength of polyethylene-based resins, polypropylene-based resins, olefin-based elastomers, etc., it is preferable that the tensile elastic modulus of the film obtained by these resins alone is in the range of 100 to 2000 MPa. When the tensile elastic modulus is in the range of 100 to 2000 MPa, it is possible to impart appropriate flexibility to the film of the present invention. It is more preferably in the range of 150 to 1900 MPa, still more preferably in the range of 200 to 1800 MPa.

Further, from the viewpoint of imparting rigidity to the obtained film, it is preferable to contain homopolypropylene among the polyolefin-based resins. The content of homopolypropylene is preferably in the range of 70.0 to 95.0% by mass when the total weight of the polyolefin resin is 100% by mass. By setting the amount of homopolypropylene to 70.0 to 95.0% by mass or more, it is possible to impart sufficient rigidity and processability of the obtained film. It is more preferably 71.0 to 94.0% by mass or more, and further preferably 72.0 to 93.0% by mass or more.
Here, when the film is a laminated film, the total weight of the polyolefin-based resin of the entire laminated film is set to 100% by mass, and the total weight of the homopolypropylene of the entire laminated film is calculated.

Further, for the purpose of adjusting the rigidity of the obtained film and imparting sufficient elongation at break, one or more of polyethylene-based resin, random polypropylene, and olefin-based elastomer shall be used as the polyolefin-based resin other than the homopolypropylene. Is preferable.

Further, as a resin other than the above-mentioned polyethylene-based resin, polypropylene-based resin, and olefin-based elastomer, a styrene-based elastomer, cyclic olefin-based resin, polymethylpentene-based resin, and the like can be added, if necessary.

The styrene-based elastomer is preferably a block copolymer represented by the following formula (I) or (II).
X- (Y-X) n ... (I)
(XY) n ... (II)
X in the general formulas (I) and (II) is an aromatic vinyl polymer block typified by styrene, and in the formula (I), the degree of polymerization may be the same or different at both ends of the molecular chain. May be good. In addition, Y is a butadiene polymer block, an isoprene polymer block, a butadiene / isoprene copolymer block, a hydrogenated butadiene polymer block, a hydrogenated isoprene polymer block, and a hydrogenated butadiene / isoprene co-weight. At least one selected from coalesced blocks, partially hydrogenated butadiene polymer blocks, partially hydrogenated isoprene polymer blocks and partially hydrogenated butadiene / isoprene copolymer blocks. Further, n is an integer of 1 or more.

Examples of the cyclic olefin-based resin include norbornene-based polymers, vinyl alicyclic hydrocarbon polymers, and cyclic conjugated diene polymers. Among these, norbornene-based polymers are preferable. Examples of the norbornene-based polymer include a ring-opening polymer of a norbornene-based monomer, a norbornene-based copolymer obtained by copolymerizing a norbornene-based monomer and an α-olefin such as ethylene. Moreover, these hydrogenated additives can also be used.

<Nucleating agent>
In the resin composition used in the present invention, a nucleating agent is used as an essential component for the purpose of imparting rigidity to the obtained film.
The type of nucleating agent used in the present invention is not particularly limited as long as it has the effect of improving the transparency of the polypropylene-based resin. For example, metal salts of benzoic acids such as sodium benzoate, aluminum-p-tert-butylbenzoate, lithium-p-tert-butylbenzoate, 2,2-methylenebis (4,6-ditertiary butylphenyl) phosphate ester lithium and 2,2-Methylenebis (4,6-ditertiary butylphenyl) phosphate ester metal salts such as sodium phosphate, dibenzylidene sorbitol, bis (4-methylbenziliden) sorbitol, bis (4-ethylbenzylidene) sorbitol, Benzylidene sorbitols such as bis (dimethylbenziliden) sorbitol, metal alcoholates such as zinc glycerin; amino acid metal salts such as zinc glutamate; aliphatic dibasic acids having a bicyclo structure such as bicycloheptanedicarboxylic acid or salts thereof and metal salts thereof. , Kinakridones, talc, etc. Above all, from the viewpoint of improving transparency, it is preferable to use benzylidene sorbitols.

The nucleating agent is preferably 0.1 to 0.28 parts by mass with respect to 100 parts by mass of the polyolefin resin. By using 0.1 part by mass or more of the nucleating agent, it is possible to promote the crystallization of the obtained film and impart sufficient rigidity. By using 0.28 parts by mass or less of the nucleating agent, there is no problem in film formation and the amount of the film added can be suppressed, which is preferable from the viewpoint of economy. It is more preferably 0.1 to 0.26 parts by mass, and even more preferably 0.1 to 0.24 parts by mass.
Here, when the film is a laminated film, the content of the nucleating agent is calculated with the polyolefin resin in the layer containing the nucleating agent as 100 parts by mass.

<Other ingredients>
In addition to the above-mentioned polyolefin-based resin and nucleating agent, various additives can be added to the resin composition used for the polyolefin-based resin film of the present invention in order to impart heat resistance, weather resistance, and the like.
Specific examples include, for example, antistatic agents, antioxidants, neutralizers, lubricants, antiblocking agents, plasticizers, heat stabilizers, light stabilizers, dyes and pigments, ultraviolet absorbers, fillers, and rigidity. Inorganic fillers and elastomers other than those described above for imparting flexibility may be used as long as the effects of the present invention are not impaired.

As the ultraviolet absorber, known ones can be used, and examples thereof include a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, and a triazine-based ultraviolet absorber.

As the light stabilizer, known ones can be used, and examples thereof include hindered amine-based light stabilizers.

As the antistatic agent, known ones can be used, but a polymer type antistatic agent may be used in order to impart long-term antistatic properties to the film and suppress defects caused by bleeding out to the surface. preferable. As a specific example of the polymer antistatic agent, known ones can be used, for example, a block copolymer of a hydrophobic block and a hydrophilic block can be used, and a hydrophobic block and a hydrophilic block can be used. However, examples thereof include those in which a block copolymer is formed by an ester bond, an ether bond, an amide bond, an imide bond, a urethane bond, a urea bond, or the like.

As a lubricant or anti-blocking agent, it has excellent compatibility with the above-mentioned polyolefin resin, and it enables defects due to bleed-out to the surface of the obtained film and long-term scratch resistance and slipperiness. It is preferable to use a silicone-olefin copolymer.

<Polyolefin resin film>
The polyolefin-based resin film of the present invention refers to a single-layer or multi-layer film obtained by molding a resin composition containing the above-mentioned polyolefin-based resin and a nucleating agent. Further, the obtained film has a tensile elastic modulus in the range of 1000 to 1500 MPa before and after heating at 110 ° C. for 60 minutes, and a tensile elongation at break after heating at 110 ° C. for 60 minutes is 100% or more. It is a film characterized by being.

The thickness of the film is 50 to 200 μm, and within this range, even the highly rigid film obtained in the present invention is sufficient in the step of laminating the adhesive layer and the step of laminating the printing layer, which will be described later. It is possible to maintain workability. It is more preferably 60 to 190 μm, still more preferably 70 to 180 μm.

Further, it is necessary that both the tensile elastic modulus before heating and the tensile elastic modulus after heating when the film is heated at 110 ° C. for 60 minutes are in the range of 1000 to 1500 MPa. When the tensile elastic modulus before heating is 1000 MPa or more, it is possible to suppress the deformation and the thickness change of the film even in the step of laminating the adhesive layer and the step of laminating the printing layer, which will be described later. When the tensile elastic modulus before heating is 1500 MPa or less, it is possible to suppress the decrease in elongation at break while maintaining the rigidity of the film. It is more preferably 1000 to 1450 MPa, still more preferably 1000 to 1400 MPa.
Further, it is necessary that the tensile elastic modulus after heating is also in the range of 1000 to 1500 MPa. When the tensile elastic modulus after heating is 1000 MPa or more, it can be judged that even when the crystallization of the polyolefin resin with time of the film is promoted, there is little significant change in rigidity and the stability with time is excellent. It will be possible. When the tensile elastic modulus after heating is 1500 MPa or less, it is possible to suppress the decrease in elongation at break while maintaining the rigidity of the film. It is more preferably 1000 to 1450 MPa, still more preferably 1000 to 1400 MPa.

From the viewpoint of the stability of the film over time, it is also necessary that the tensile elongation at break of the film after heating at 110 ° C. for 60 minutes is 100% or more. If the tensile elongation at break of the film after heating is 100% or more, the film will not break during processing even if the crystallization of the olefin resin is promoted over time, and the adhesive layer or Even in the step of laminating the print layer, since there is an appropriate elongation, the film does not break and it is possible to maintain good passability in these steps. The tensile elongation at break after heating is more preferably 200% or more, still more preferably 300% or more. The greater the tensile elongation at break, the lower the risk of fracture.

The polyolefin-based resin film of the present invention may be a single-layer film or a multi-layer film.
In the case of a multi-layer film, it is preferable that the film is composed of at least two or more layers, that is, an outer layer that does not contain the above-mentioned nucleating agent and a layer that contains the nucleating agent. Since the layer containing no nucleating agent has a low crystallinity after film formation and is excellent in flexibility, it is necessary to improve the tensile elongation at break of the film and maintain good processability in the process of laminating the adhesive layer and the printing layer. Is preferable because it enables. From the viewpoint of suppressing breakage of the film, it is more preferable to use a layer containing no nucleating agent for both the front and back outer layers of the film.

As a film forming method, a known method can be used, but it is preferable to use a melt extrusion molding method. Among the melt extrusion molding methods, the T-die molding method in which a resin in a molten state is extruded from an extruder having a T-die and cooled and solidified to obtain a film is more preferable.

In order to obtain a film, it is preferable to use a coextrusion T-die molding method using a plurality of extruders. By using the coextrusion T-die molding method using multiple extruders, it is possible to obtain a multi-layer film, and by extruding the same resin from all the extruders, all the layers are the same resin. It is also possible to obtain a substantially single layer film composed of the composition.
As a coextrusion T-die molding method, a method of forming a plurality of resin layers into a film by using a multi-manifold die and then contacting the resin layers in the T-die to form a multi-layered film, and a melting method called a feed block. Examples thereof include a method of obtaining a multi-layer film after merging and adhering a plurality of resins using a device for merging the resins in the state.
If necessary, the film may be surface-treated on one or both sides by a method such as plasma treatment, corona treatment, ozone treatment, and flame treatment. Depending on the application of the obtained film, it is possible to select whether to perform surface treatment on one side or both sides.
Further, in the case of a multi-layer film, it is preferable that the thickness of the outer layer is within the range of 5 to 40% of the total thickness. When it is 5% or more, it is possible to fully express the performance of the additive when various additives are added only to the outer layer, and when it is 40% or less, it is possible to form a film when obtaining a multi-layer film. It is preferable because it is possible to maintain good sex and economic efficiency. It is more preferably in the range of 5 to 35%, still more preferably in the range of 5 to 30%.

<Adhesive film>
The polyolefin-based resin film of the present invention can be made into an adhesive film by laminating an adhesive layer on at least one surface (hereinafter, also referred to as "adhesive film of the present invention").
The pressure-sensitive adhesive used as the pressure-sensitive adhesive layer is not particularly limited, and for example, various pressure-sensitive adhesives such as natural rubber-based resin, acrylic-based resin, styrene-based resin, silicon-based resin, and polyvinyl ether-based resin are used. Further, a functional layer such as an adhesive layer or a thermosetting resin layer may be further provided on the pressure-sensitive adhesive layer.

In the pressure-sensitive adhesive film of the present invention, one or both sides of the film before laminating the pressure-sensitive adhesive layer may be subjected to the above-mentioned surface treatment. Further, a primer layer may be provided between the base film, which is the polyolefin resin film of the present invention, and the adhesive layer, if necessary.
The thickness of the adhesive layer and the primer layer can be appropriately determined as needed.

<Cosmetic film>
The polyolefin-based resin film of the present invention can be formed into a decorative film by laminating a printing layer on at least one side thereof (hereinafter, also referred to as "decorative film of the present invention").
The print layer constituting the decorative film can be formed by a known method. For example, a known printing method such as an offset printing method, a gravure rotary printing method, and a screen printing method, a known coating method such as a roll coating method and a spray coating method, a flexographic printing method, and the like can be mentioned. Further, a thin-film deposition method can also be used.
Examples of the printed pattern include a pattern consisting of wood grain, stone grain, cloth grain, sand grain, geometric pattern, characters, solid surface, metallic, and the like.
The thickness of the print layer can be appropriately determined as needed.
In the decorative film of the present invention, the above-mentioned surface treatment may be applied to one or both sides of the film before laminating the print layer. Further, a primer layer may be provided between the base film and the printing layer, if necessary.
The thickness of the print layer and the primer layer can be appropriately determined as needed.

<Adhesive film for cosmetics>
The decorative film of the present invention can be made into a cosmetic adhesive film by further laminating an adhesive layer on the printed layer, if necessary.
By attaching the cosmetic adhesive film to the adherend, it is possible to give a beautiful appearance to the adherend, and it is possible to give a beautiful appearance to the adherend, and it is used for cosmetics for interior and exterior of automobiles, other molded bodies and laminates, and applications for interior and exterior of buildings. It can be used for such purposes.

The polyolefin-based resin film of the present invention has excellent rigidity, processability, and handleability. Further, it is also possible to obtain an adhesive film or a decorative film by laminating an adhesive layer or a printing layer on the film, and these films can be suitably used for automobile cosmetic applications.

Hereinafter, examples and comparative examples of the present invention will be shown and specifically described, but the present invention is not limited to these examples. The materials used in the following examples and comparative examples, the method for measuring the evaluated characteristics, and the like are as follows.

[Material used]
<Polyolefin resin>
Homopolypropylene (A):
"MA3U" manufactured by Japan Polypropylene Corporation (homopolypropylene, melt flow rate at 230 ° C., 2.16 kg: 15.0 g / 10 minutes, melting point: 168 ° C., tensile modulus of elasticity of a single film: 900 MPa)
Homopolypropylene (B):
"FLX80E4" manufactured by Sumitomo Chemical Co., Ltd. (homopolypropylene, melt flow rate at 230 ° C., 2.16 kg: 8.0 g / 10 minutes, melting point: 163 ° C., tensile modulus of elasticity of a single film: 900 MPa)

Random polypropylene:
"PC630A" manufactured by SunAllomer Ltd. (random polypropylene, melt flow rate at 230 ° C., 2.16 kg: 7.5 g / 10 minutes, melting point: 135 ° C., tensile modulus of elasticity of a single film: 600 MPa)
Olefin elastomer:
"Wellnex RFX4V" manufactured by Japan Polypropylene (olefin elastomer, melt flow rate at 230 ° C., 2.16 kg: 6.0 g / 10 minutes, melting point: 127 ° C., tensile modulus of elasticity of a single film: 250 MPa)

Low density polyethylene:
Made by Japan Polyethylene Corporation, "Novatec LC500, 190 ° C, 2.16 kg melt flow rate: 4.0 g / 10 minutes, melting point: 106 ° C, tensile modulus of single film: 140 MPa)
Linear low density polyethylene:
Ube-Maruzen Polyethylene Co., Ltd., "Umerit 0540F, 190 ° C, 2.16 kg melt flow rate: 4.0 g / 10 minutes, melting point: 87 and 111 ° C, tensile modulus of single film: 80 MPa)

<Nucleating agent>
Masterbatch of nucleating agent:
"Clearmaster PP-RM-SKZ H8020" manufactured by Dainichiseika Kogyo Co., Ltd. (Homopolypropylene-based nucleating agent masterbatch containing 20% by mass of nucleating agent)

<Preparation of resin composition>
Using the above-mentioned polyolefin resin, the layers are blended so that the total amount of each layer is 100 parts by mass based on the description in Table 1, and the nucleating agent is further added to 100 parts by mass of the polyolefin resin as shown in Table 1. Was added and mixed by dry blending. After visually confirming that the mixture was uniformly mixed, a resin composition for film molding was prepared.

<Method of forming a multi-layer film>
For each hopper of three Toshiba Machine single-screw extruders (for outer layer: 35φmm, L / D = 25mm, for intermediate layer: 50φmm, L / D = 32, for outer layer: 35φmm, L / D = 25mm) The dry-blended raw material is put in, the extruder temperature for each of the outer layer and the intermediate layer is set to 210 to 230 ° C, and the extruder is merged into the three-layer structure of the outer layer / intermediate layer / outer layer at the feed block portion to have a width of 650 mm. Extruded from a T-die (temperature setting 230 ° C., lip opening 0.5 mm). As for the thickness configuration, each extruder rotation speed was set so as to be 16.5 μm / 132 μm / 16.5 μm.
The extruded molten resin is cooled and solidified by a winder equipped with a mirror-shaped cooling roll (cooling roll 700 mm width x φ350 mm, roll temperature of about 30 ° C.), and then corona-treated on both sides to perform winding. A film composed of two types and three layers having a thickness of about 165 μm and a substantially single resin layer having one type and three layers was obtained.

[Content of homopolypropylene]
The blending amount of polypropylene contained in both outer layers and the intermediate layer was calculated and calculated using the thickness and total thickness of each layer.

[Film thickness]
The thickness of the central part of the film was measured with a contact thickness gauge.

[Tension modulus (before heating)]
A dumbbell-shaped test piece was collected from the obtained film using a dumbbell "SDK-600" prepared according to JIS K6732. For the obtained dumbbell-shaped test piece, refer to JIS K7127, collect the No. 1 dumbbell test piece from the obtained film, and under an atmosphere of 23 ° C. and 50% RH, Autograph (AGS-X manufactured by Shimadzu Corporation). The tensile elastic modulus (MPa) was measured at a tensile speed of 50 mm / min with a chuck-to-chuck distance of 40 mm.
The test piece was collected and the tensile elastic modulus was measured in the direction orthogonal to the extrusion direction of the film (TD direction).

[Tension modulus (after heating)]
The obtained film was cut into A4 size, and the film was allowed to stand in a hot air circulation type dryer set at 110 ° C. for 60 minutes for heat treatment. After the heat treatment, a dumbbell-shaped test piece was collected using a dumbbell "SDK-600" prepared according to JIS K6732. The obtained dumbbell-shaped test piece was subjected to an atmosphere of 23 ° C. and 50% RH with reference to JIS K7127, and an autograph (AGS-X manufactured by Shimadzu Corporation) was used to set the distance between chucks to 40 mm and a tensile speed of 50 mm /. The tensile modulus (MPa) was measured in minutes.
The test piece was collected and the tensile elastic modulus was measured in the direction orthogonal to the extrusion direction of the film (TD direction).

[Tension breaking elongation (before heating)]
A dumbbell-shaped test piece was collected from the obtained film using a dumbbell "SDK-600" prepared according to JIS K6732. For the obtained dumbbell-shaped test piece, refer to JIS K7127, collect the No. 1 dumbbell test piece from the obtained film, and in an atmosphere of 23 ° C. and 50% RH, a small tabletop tester (EZ- manufactured by Shimadzu Corporation). Using L), the distance between the chucks was set to 40 mm, and the tensile elongation at break (%) was measured at a tensile speed of 300 mm / min.
The test piece was collected and the tensile elongation at break was measured in the direction orthogonal to the extrusion direction of the film (TD direction).

[Tension breaking elongation (after heating)]
The obtained film was cut into A4 size, and the film was allowed to stand in a hot air circulation type dryer set at 110 ° C. for 60 minutes for heat treatment. After the heat treatment, a dumbbell-shaped test piece was collected using a dumbbell "SDK-600" prepared according to JIS K6732. The obtained dumbbell-shaped test piece was subjected to a chuck-to-chuck distance of 40 mm using a small tabletop tester (EZ-L manufactured by Shimadzu Corporation) in an atmosphere of 23 ° C. and 50% RH with reference to JIS K7127, and a tensile speed. The tensile elongation at break (%) was measured at 300 mm / min.
The test piece was collected and the tensile elongation at break was measured in the direction orthogonal to the extrusion direction of the film (TD direction).

[Example 1]
Homopolypropylene (A) and random polypropylene were used as the polyolefin resins used for the outer layer and the intermediate layer, and the nucleating agent masterbatch was blended only in the intermediate layer to obtain a film consisting of two types and three layers. The various polyolefin resins, the nucleating agent masterbatch, and the nucleating agents in the masterbatch are as shown in Table 1.
The content of homopolypropylene in the polyolefin resin used for the multilayer film was 74.0% by mass.
The film obtained was 165 μm. The tensile elastic modulus before heating was 1020 MPa and the tensile elongation at break was 820%, the tensile elastic modulus after heating was 1220 MPa, and the tensile elongation at break was 600%.
Since the tensile elastic modulus is in the range of 1000 to 1500 MPa before and after heating and the tensile elongation at break after heating is 100% or more, a film having both good rigidity and workability can be obtained. Was done.

[Example 2]
The same procedure as in Example 1 was carried out except that the amounts of homopolypropylene (B) and olefin elastomer were used in Table 1.
The content of homopolypropylene in the polyolefin resin used for the multilayer film was 84.0% by mass.
The film obtained was 165 μm. The tensile elastic modulus before heating was 1070 MPa and the tensile elongation at break was 840%, the tensile elastic modulus after heating was 1180 MPa, and the elongation at break was 670%.
Since the tensile elastic modulus is in the range of 1000 to 1500 MPa before and after heating and the tensile elongation at break after heating is 100% or more, a film having both good rigidity and workability can be obtained. Was done.

[Example 3]
The same procedure as in Example 2 was carried out except that the amounts of homopolypropylene (B) and olefin elastomer were used in Table 1.
The content of homopolypropylene in the polyolefin resin used for the multilayer film was 94.0% by mass.
The film obtained was 165 μm. The tensile elastic modulus before heating was 1280 MPa and the tensile elongation at break was 830%, the tensile elastic modulus after heating was 1310 MPa, and the tensile elongation at break was 570%.
Since the tensile elastic modulus is in the range of 1000 to 1500 MPa before and after heating and the tensile elongation at break after heating is 100% or more, a film having both good rigidity and workability can be obtained. Was done.

[Comparative Example 1]
The polyolefin-based resin was only homopolypropylene (A), and no nucleating agent was added, to obtain a substantially single-layer film of one type and three layers in which both outer layers and intermediate layers were made of the same resin.
The content of homopolypropylene in the polyolefin resin used for the multilayer film was 100% by mass.
The obtained film was 165 μm, and the tensile elastic modulus before heating was 900 MPa. Since there is no nucleating agent, the tensile elastic modulus is below the range of 1000 to 1500 MPa, so it was confirmed that the film is inferior in rigidity.

[Comparative Example 2]
The procedure was the same as in Comparative Example 1 except that a nucleating agent was used for the intermediate layer.
The content of homopolypropylene in the polyolefin resin used for the multilayer film was 100% by mass.
The film obtained was 165 μm. The tensile elastic modulus before heating was 1190 MPa and the tensile elongation at break was 730%, the tensile elastic modulus after heating was 1530 MPa, and the elongation at break was 10%.
This multi-layer film had a tensile elastic modulus in the range of 1000 to 1500 MPa before heating and a tensile elongation at break of 100% or more, but the tensile elastic modulus after heating exceeded the range of 1000 to 1500 MPa. Further, the tensile modulus at break was 100% or less.
Therefore, the film has a high possibility of being inferior in processability due to a large change in elastic modulus and breaking elongation over time.

[Comparative Example 3]
The procedure was carried out in the same manner as in Example 1 except that the blending amounts of the homopolypropylene (A) and the random polypropylene in the intermediate layer were as shown in Table 1.
The content of homopolypropylene in the polyolefin resin used for the multilayer film was 66.0% by mass.
The obtained film was 165 μm, and the tensile elastic modulus before heating was 940 MPa. Since the amount of homopolypropylene compounded was small and the tensile elastic modulus was below the range of 1000 to 1500 MPa, it was confirmed that the film was inferior in rigidity.

[Comparative Example 4]
Homopolypropylene (A), low-density polyethylene, and linear low-density polyethylene are used as the polyolefin resin used for the outer layer and the intermediate layer, and the nucleating agent masterbatch is blended only in the intermediate layer to form a film consisting of two types and three layers. Got The various polyolefin resins, the nucleating agent masterbatch, and the nucleating agents in the masterbatch are as shown in Table 1.
The content of homopolypropylene in the polyolefin resin used for the multilayer film was 95.2% by mass.
The film obtained was 165 μm. The tensile elastic modulus before heating was 1020 MPa and the tensile elongation at break was 560%, the tensile elastic modulus after heating was 1250 MPa, and the tensile elongation at break was 20%.
The tensile elastic modulus before and after heating of this multi-layer film was in the range of 1000 to 1500 MPa, but the result was that the tensile elongation at break after heating was 100% or less due to the large amount of homopolypropylene.
Therefore, although the film had good rigidity, the film had a large change in elongation at break with time and was highly likely to be inferior in processability.

[Example 4]
An acrylic pressure-sensitive adhesive (SK Dyne 1502C manufactured by Soken Kagaku Co., Ltd.) was applied on a separator on the mirror-like cooling roll side surface of the film obtained in Example 1 by a comma-coating method, and the pressure-sensitive adhesive layer was dried. After coating to a thickness of 25 μm and drying in a hot air dryer at 80 ° C. for 5 minutes, an adhesive layer is formed, and the adhesive layer is attached to the mirror-shaped cooling roll side. An adhesive film was obtained.

[Example 5]
The ink manufactured by DIC Graphics Co., Ltd. described below was applied to the mirror-shaped cooling roll side surface of the film obtained in Example 1 by Kurashiki Spinning Co., Ltd., a gravure printing tester "GP-2". The film was coated using the printing plate "54L6 gradation". The coated film was aged at 40 ° C. for 5 days to obtain a decorative film on which a printing layer with ink was laminated.
<Ink manufactured by DIC Graphics Co., Ltd.>
95% by mass of "VTP-NT40 yellow (A)" and 5% by mass of "AT-NT solvent"
Was mixed and stirred to prepare an ink.
"VTP-NT40 Yellow (A)": Paint consisting of a mixture of vinyl chloride / vinyl acetate copolymer and acrylic resin and methyl isobutyl ketone as a solvent "AT-NT solvent": Mixture of butyl acetate / ethyl acetate / methyl ethyl ketone

[Example 6]
An acrylic pressure-sensitive adhesive (SK Dyne 1502C manufactured by Soken Kagaku Co., Ltd.) was applied on the separator of the decorative film obtained in Example 5 by a comma-coating method, and the thickness of the pressure-sensitive adhesive layer after drying was 25 μm. After coating for 5 minutes in a hot air dryer at 80 ° C., an adhesive layer is formed, and the adhesive layer is attached to the surface of the decorative film obtained in Example 5 on the print layer side. By combining them, a cosmetic adhesive film was obtained.

[Industrial applicability]
By using a film made of a resin composition using the polyolefin-based resin and the nucleating agent of the present invention, it is possible to obtain a film that solves these problems such as rigidity, processability, and handleability of the film. Further, it is also possible to obtain an adhesive film or a decorative film by laminating an adhesive layer or a printing layer on the film, and these films can be suitably used for interior / exterior of buildings, interior / exterior of automobiles, and cosmetic applications. ..

Claims (8)

A film composed of a resin composition containing a polyolefin resin and a nucleating agent, the tensile elastic modulus before and after heating at 110 ° C. for 60 minutes is in the range of 1000 to 1500 MPa, and at 110 ° C. A polyolefin-based resin film having a tensile modulus at break of 100% or more after heating for 60 minutes. The polyolefin-based resin film according to claim 1, wherein the polyolefin-based resin contains at least one selected from the group consisting of polyethylene-based resins, random polypropylenes, and olefin-based elastomers, and contains homopolypropylene. .. The polyolefin-based resin according to claim 1 or 2, wherein the content of homopolypropylene is in the range of 70.0 to 95.0% by mass when the total weight of the polyolefin-based resin is 100% by mass. the film. The polyolefin-based resin film according to any one of claims 1 to 3, which contains 0.1 to 0.28 parts by mass of a nucleating agent with respect to 100 parts by mass of the polyolefin-based resin. The polyolefin-based resin film according to any one of claims 1 to 4, wherein the polyolefin-based resin film is composed of at least two or more layers, that is, an outer layer that does not contain a nucleating agent and a layer that contains a nucleating agent. An adhesive film obtained by laminating an adhesive layer on at least one surface of the polyolefin-based resin film according to any one of claims 1 to 5. A decorative film obtained by laminating a printing layer on at least one side of the polyolefin-based resin film according to any one of claims 1 to 5. A cosmetic adhesive film obtained by further laminating an adhesive layer on the print layer side of the decorative film according to claim 7.