WO2010001959A1 - Pressure-sensitive adhesive film, laminate using the pressure-sensitive adhesive film and method for protecting molded article - Google Patents

Abstract

Provided is a pressure-sensitive adhesive film which scarcely generates wrinkles, peeling off or the like and scarcely causes any color change of a base material in the case of repeatedly bonding to a molded article comprising a synthetic resin. A pressure-sensitive adhesive film provided with a base material layer and a pressure-sensitive adhesive layer, wherein a resin composition forming the base material layer comprises an aromatic vinyl elastomer resin having a styrene content of 30 to 76 mol %.  When bonded to a molded article comprising a synthetic resin, the aforementioned pressure-sensitive adhesive film can protect the molded article while scarcely generating wrinkles, peeling off or the like and scarcely causing any color change of the base material.

Description

Adhesive film, laminate using the adhesive film, and method for protecting molded article

The present invention relates to an adhesive film. More specifically, the present invention relates to a pressure-sensitive adhesive film, a laminate using the pressure-sensitive adhesive film, and a method for protecting a synthetic resin molded body.

Passenger conveyors called escalators and moving walkways, which are examples of synthetic resin moldings, are installed in public facilities and various buildings such as department stores, stations, and airports for that purpose, and are used for many people. . For this reason, various methods have been proposed regarding a method for providing a display of advertisements, guidance, and the like on the conveyor handrail used as the moving handrail.

As an example of such a method, a method of adhering a resin adhesive film having information content printed on a conveyor handrail has been proposed. These adhesive films also function as a protective film that prevents a molded product made of synthetic resin such as a conveyor handrail from being soiled. The dirt can be easily removed by wiping, and if the protective film is appropriately replaced, the appearance of the synthetic resin molded article can be maintained over a long period of time.

Since the conveyor handrail rotates together with the conveyor, the film attached to the conveyor handrail is required to have flexibility to follow the movement of the conveyor handrail. Patent Document 1 is characterized in that a polyurethane film surface-treated with a ketone organic solvent or a halogenated hydrocarbon organic solvent is fixed on a decorative rubber layer of a conveyor handrail so that the surface-treated surface side is in contact with the polyurethane film. And a conveyor handrail with a pattern are disclosed.

Patent Document 2 discloses a pressure-sensitive adhesive sheet in which a thermoplastic polyurethane resin film and a pressure-sensitive adhesive layer are laminated, and the stress 0 strain when the thermoplastic polyurethane resin film is stretched by 5% is 0.4% or less. A pressure-sensitive adhesive sheet for conveyor handrails is disclosed.

Japanese Patent Laid-Open No. 10-305487 JP 2006-347648 A

However, the film according to Patent Document 1 and the pressure-sensitive adhesive sheet according to Patent Document 2 have a problem in that discoloration of the pressure-sensitive adhesive sheet occurs when it is attached to a molded body made of a synthetic resin made of a material containing an amine anti-aging agent. It was.

Therefore, the main object of the present invention is to provide a pressure-sensitive adhesive film that is less likely to cause wrinkling and peeling, and less susceptible to discoloration of the base material, even if it is stuck to a synthetic resin molding and repeatedly used.

In order to solve the above technical problem, the present invention first comprises a base material layer and an adhesive layer,
Provided is an adhesive film in which the resin composition forming the base material layer is an aromatic vinyl elastomer resin having a styrene content of 30 to 76 mol%. Since the adhesive film according to the present invention uses a specific aromatic vinyl elastomer resin for the base material layer, discoloration of the adhesive film occurs even if it is attached to a molded body made of a material containing an amine anti-aging agent. Hateful.
If the base material layer of the pressure-sensitive adhesive film according to the present invention is formed of an aromatic vinyl elastomer resin having a styrene content of 30 to 76%, the type of the aromatic vinyl elastomer resin is not particularly limited, but a styrene-butadiene random copolymer is used. A hydrogenated polymer and / or styrene-butadiene random copolymer is preferred.
The pressure-sensitive adhesive film according to the present invention preferably has a 2% extension strength of 1 to 10 N / 10 mm.
In addition, the 2% modulus of the pressure-sensitive adhesive film according to the present invention is preferably 0.5 to 8 MPa.
Furthermore, the pressure-sensitive adhesive film according to the present invention has a color difference ΔE ^* calculated by the following mathematical formula (1) between the hue measured in the Lab color system at 23 ° C. and 50% RH and the hue after 20 days ^. It is preferable that ab is 10 or less. Note that L ^*, a ^{*, and} b ^* in the mathematical formulas indicate the values of the L ^* , a ^* , and b ^* axes in the Lab color system, respectively. ΔL ^* , Δa ^* , and Δb ^* indicate differences between L ^* , a ^* , and b ^* measured immediately after sample preparation and 20 days later, respectively.

In the pressure-sensitive adhesive film according to the present invention, it is preferable that a light-transmitting protective film is laminated on the base material layer. By laminating such a protective film, the base layer can be prevented from being stained or worn.
In the pressure-sensitive adhesive film according to the present invention, the pressure-sensitive adhesive layer is preferably made of an acrylic pressure-sensitive adhesive.
The base layer of the pressure-sensitive adhesive film according to the present invention preferably contains 100 parts by mass of the resin composition and 0.08 to 3 parts by mass of particles having a volume average particle diameter of 4 to 25 μm. Thus, moderate unevenness | corrugation can be provided to the surface of an adhesive film by preparing containing particle | grains.
In this case, the difference in refractive index between the resin composition and the particles contained in the resin composition is preferably 0.04 or less. This is to maintain the transparency of the adhesive film.

Next, in the present invention, the pressure-sensitive adhesive film according to the present invention and a synthetic resin molded body laminated on the pressure-sensitive adhesive film,
Provided is a laminate in which the synthetic resin constituting the molded body contains an amine-based anti-aging agent.
The kind of the amine-based anti-aging agent used in the laminate according to the present invention is not particularly limited, but as an example, it is preferable to use a phenylenediamine-based anti-aging agent.

In the present invention, further, a method for protecting a molded body for protecting the molded body by sticking an adhesive film to a molded body made of synthetic resin,
The synthetic resin forming the molded body has a styrene butadiene rubber and an amine anti-aging agent,
Provided is a method for protecting a molded article using the adhesive film according to the present invention as the adhesive film.
The type of the amine-based anti-aging agent used in the molded article protected by the protection method according to the present invention is not particularly limited, but as an example, it is preferable to use a phenylenediamine-based anti-aging agent.

Here, terms relating to the present invention will be explained. In the present invention, “2% modulus” is a value obtained by reading the tensile strength at the time of elongation of 2% from the curve at the time of pulling a hysteresis curve with stress and strain as axes, and dividing by the total cross-sectional area of the adhesive film. .

In the present invention, the “styrene content” represents the content of styrene and / or a styrene-substituted product in all monomers constituting the resin aromatic vinyl elastomer resin.

ADVANTAGE OF THE INVENTION According to this invention, even if it sticks to the synthetic resin molded object and it uses repeatedly, it can provide that it is hard to produce a wrinkle, peeling, etc., and to provide the adhesive film which does not produce discoloration of a base material easily. .

Hereinafter, preferred embodiments for carrying out the present invention will be described. In addition, embodiment described below shows an example of typical embodiment of this invention, and, thereby, the range of this invention is not interpreted narrowly.

<Adhesive film>
The pressure-sensitive adhesive film according to the present invention comprises a base material layer and a pressure-sensitive adhesive layer, and the base material layer is formed from an aromatic vinyl elastomer resin having a styrene content of 30 to 76 mol%. The pressure-sensitive adhesive film according to the present invention is characterized in that, when used by being attached to a molded body made of a synthetic resin, wrinkles and peeling are less likely to occur and discoloration of the substrate is less likely to occur. Hereinafter, the configuration will be described in detail.

The base material layer of the pressure-sensitive adhesive film according to the present invention is formed from an aromatic vinyl elastomer resin having a styrene content of 30 to 76 mol%.

The aromatic vinyl elastomer resin is a block copolymer composed of an aromatic vinyl hydrocarbon polymer block and an elastomeric polymer block, and the aromatic vinyl hydrocarbon polymer block comprises a hard segment, Elastomeric polymer blocks each constitute a soft segment.

Generally, the aromatic vinyl elastomer resin is an aromatic vinyl hydrocarbon polymer block-elastomeric polymer block or an aromatic vinyl hydrocarbon polymer block-elastomeric polymer block-aromatic vinyl hydrocarbon polymer. It has a copolymer structure represented by a block.

Examples of the aromatic vinyl hydrocarbon polymer block of the aromatic vinyl elastomer resin used as the base layer of the adhesive film according to the present invention include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p -Methylstyrene, 1,3-dimethylstyrene, vinylnaphthalene, vinylanthracene and the like. Among these, styrene and / or a styrene-substituted product is contained in an amount of 25 to 85 mol% in all monomers constituting the aromatic vinyl elastomer resin. Of styrene and styrene-substituted products, styrene and α-methylstyrene are preferably used. These polymer blocks can be used alone or in combination of two or more.

The elastomeric polymer block of the aromatic vinyl elastomer resin used as the base material layer of the pressure-sensitive adhesive film according to the present invention is not particularly limited as long as the elastomeric property is expressed, and the conjugated diene polymer block or other heavy polymer block. A combined block can be used, but a conjugated diene polymer block is preferred. Specific examples in this case include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and the like. Of these, 1,3-butadiene and isoprene are particularly preferably used.

An aromatic vinyl elastomer resin can be obtained by appropriately combining the above-mentioned aromatic vinyl hydrocarbon polymer block and an elastomeric polymer block. Specific examples include, for example, styrene-ethylene-butylene copolymer-styrene (SEBS), styrene-ethylene-propylene copolymer-styrene (SEPS), styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS). ABA block copolymers, random copolymers, tapered copolymers, star block copolymers, multiblock copolymers, and hydrogenated products thereof.

Also, AB block copolymers such as styrene-butadiene copolymers and styrene-isoprene copolymers, random copolymers, tapered copolymers, star block copolymers, multi-block copolymers And hydrogenated products thereof.

Of these, styrene-butadiene random copolymer and / or styrene-butadiene random copolymer hydrogenated product is preferable from the viewpoint of wear resistance, followability to a synthetic resin molded product, and transparency, and styrene-butadiene. A completely hydrogenated random copolymer is particularly preferred.

The styrene content in all the monomers constituting the aromatic vinyl elastomer resin is 30 to 76 mol%, preferably 50 to 76%. When the styrene content in the total monomer constituting the aromatic vinyl elastomer resin is less than 30 mol%, the abrasion resistance is poor, and scratches may occur when the product is attached to a molded product and the appearance may be impaired. There is. In addition, when the styrene content exceeds 76 mol%, the followability to a synthetic resin molded product is inferior. For example, when the molded product rotates with a conveyor such as a conveyor handrail, wrinkles and floats occur. However, the appearance may be impaired.

The styrene content in the aromatic elastomer resin body in the present invention is measured by the following method.
Device name: Superconducting nuclear magnetic resonance (NMR) device (trade name “α-500”, manufactured by JEOL Ltd.)
Test method: An analytical method for examining the properties of molecules such as the structure and motion state using nuclear magnetic resonance, and using a deuterated chloroform solvent or deuterated 1,1,2,2-tetrachloroethane solvent as a standard and a phenyl group based on TMS. The intensity of the proton-derived peak (6.5 to 7.5 ppm) and the alkyl group-derived proton peak (0.8 to 3 ppm) are compared.

The base layer of the adhesive film according to the present invention is not particularly limited as long as it contains an aromatic vinyl elastomer resin, and other resins can be freely mixed.

Specific examples of other resins blended in the base material layer of the pressure-sensitive adhesive film according to the present invention include, for example, olefin thermoplastic elastomer (TPO), polyurethane thermoplastic elastomer (TPU), polyester thermoplastic elastomer, and polyamide. Based thermoplastic elastomers, aromatic resins and the like. Of these, olefin-based thermoplastic elastomer (TPO) is particularly preferably blended.

Examples of the olefin thermoplastic elastomer include ethylene-propylene copolymers and those obtained by dispersing ethylene-propylene copolymers in polypropylene.

Polyurethane-based thermoplastic elastomers are manufactured using polyether or polyester and isocyanate (MDI, TDI, HDI) as raw materials. Polyether-based, polyester-based, MDI-based, TDI-based, and HDI-based polyurethane heat Classified as a plastic elastomer.

Polyester-based thermoplastic elastomers are produced from polyether or polyester and alkylene terephthalate or alkylene naphthalate as raw materials, and are classified into polyether-based and polyester-based polyester-based thermoplastic elastomers depending on the combination thereof.

Polyamide-based thermoplastic elastomers are produced from polyether or polyester and polyamide as raw materials, and are classified into polyether-based and polyester-based polyamide-based thermoplastic elastomers depending on the combination thereof.

The aromatic resin refers to a resin having one or more aromatic rings in the molecule. For example, aromatic polycarbonate resin, aromatic polyester resin, polyphenylene ether resin, aromatic vinyl resin, polyphenylene sulfide Examples thereof include resins, N-aromatic substituted maleimide resins, polyimide resins, aromatic epoxy resins and the like. These resins may be used alone or in combination of two or more. Of the aromatic resins, styrene resins are particularly preferably used.

The blending amount of the resin composition blended in the base material layer of the pressure-sensitive adhesive film according to the present invention is not particularly limited, but is preferably 100 parts by mass of the aromatic vinyl elastomer resin and 5 to 20 parts by mass of the styrene resin. is there. The blending of the aromatic resin in an amount of 5 to 20 parts by mass is desirable because the resulting film has a strong strain and is excellent in workability when attached to a synthetic resin molded body.

The 2% tensile strength of the pressure-sensitive adhesive film according to the present invention is preferably 1 to 10 N / 10 mm, more preferably 2 to 7 N / 10 mm. It is because it is difficult to reduce the wear resistance of the pressure-sensitive adhesive film and the followability with respect to a synthetic resin-made molded product within this range.

The measuring method of 2% elongation strength is measured by the following method.
Device name: Tensilon tensile testing machine (Orientec Co., Ltd., trade name “UCT-500”)
Measurement method: When an adhesive film sample having a horizontal length of 20 mm and a vertical grip interval of 100 mm is stretched in the vertical direction at a speed of 300 mm / min, the tensile strength at the time of 2% elongation is converted to 10 mm width. Define the value as

The 2% modulus of the pressure-sensitive adhesive film according to the present invention is preferably 0.5 to 8 MPa, more preferably 0.8 to 5 MPa, and particularly preferably 0.8 to 3 MPa. By setting the 2% modulus to 0.5 to 8 MPa, the adhesive film expands and contracts with the expansion and contraction of the molded body made of synthetic resin. Therefore, the wear resistance and followability when adhered to the molded body are good. It is preferable because peeling and twisting are less likely to occur. In addition, the measuring method of 2% modulus is shown in the below-mentioned Example.

The 2% modulus and 2% tensile strength of the pressure-sensitive adhesive film according to the present invention can be controlled by appropriately setting the type and content of the resin blended in the pressure-sensitive adhesive film.

The color difference ΔE ^* ab calculated by the formula (1) between the hue measured in the Lab color system of the pressure-sensitive adhesive film according to the present invention and the hue after 20 days is 23 ° C., 50% RH measurement condition, It is preferable to adjust so that it may become 10 or less. This is to prevent discoloration of the adhesive sheet. Note that a method of calculating the color difference Δ ^* ab will be described in an example described later.

The pressure-sensitive adhesive film according to the present invention can be provided with a light-transmitting protective layer on the surface of the base material layer. The protective layer protects the surface of the base material layer and improves the weather resistance of the base material layer. Specific examples of the protective layer include, for example, olefin-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, resin compositions of vinylidene fluoride resin and methacrylate ester-based resins. And a laminated film of the resin composition having different compositions. Among these, particularly in the present invention, a vinylidene fluoride-based resin that is less likely to be contaminated by continuous operation of a synthetic resin molded body such as a conveyor handrail can be suitably used.

The vinylidene fluoride resin is not particularly limited as long as it is a vinyl polymer having a vinylidene fluoride monomer unit, and may be, for example, a homopolymer of vinylidene fluoride, or a single amount of vinylidene fluoride and another vinyl compound. It may be a body copolymer. Examples of vinyl compound monomers that can be used in combination with vinylidene fluoride include fluorinated vinyl compounds such as vinyl fluoride, tetrafluoroethylene, ethylene trifluoride, and hexafluoropropylene, styrene, ethylene, Examples thereof include vinyl monomers such as butadiene and propylene.

A cross-linked acrylic resin, cross-linked polystyrene resin, cross-linked styrene-acrylic copolymer resin, antibacterial agent and the like can be added to the vinylidene fluoride resin as necessary. An adhesive layer may be formed between the base material layer and the protective layer.

The thickness of the protective layer is not particularly limited, but is preferably 1 to 1000 μm, preferably 10 to 500 μm, particularly preferably 30 to 300 μm.

The base material layer of the pressure-sensitive adhesive film according to the present invention preferably contains a predetermined amount of particles having a predetermined size. By containing particles, the surface of the pressure-sensitive adhesive film can be provided with irregularities, and the stain resistance of the surface of the pressure-sensitive adhesive film can be improved.

The material for forming the particles is not particularly limited. For example, a cross-linking made of a thermoplastic resin such as methyl methacrylate polymer, methyl methacrylate-methyl acrylate copolymer, methyl methacrylate-styrene copolymer, styrene polymer, etc. In addition to particles, talc, glass beads, silicone particles, and the like can be used.

The particle size is 4 to 25 μm in volume average particle size. The thickness is preferably 6 to 20 μm, more preferably 8 to 12 μm. If the volume average particle diameter of the particles is less than 4 μm, sufficient unevenness is not imparted to the surface of the adhesive film, so that the stain resistance of the adhesive film may be lowered. On the other hand, if it exceeds 30 μm, the transparency of the pressure-sensitive adhesive film may be impaired, and the design of a synthetic resin molded body such as a conveyor handrail may become unclear.

The base material layer of the pressure-sensitive adhesive film according to the present invention may contain 100 parts by mass of the resin composition and 0.08 to 3 parts by mass of particles. The range is preferably 0.5 to 2.5 parts by mass, more preferably 1.0 to 2 parts by mass. When the content of the particles is less than 0.08 parts by mass, sufficient unevenness is not imparted to the surface of the adhesive film, so that the stain resistance of the adhesive film may not be obtained. On the other hand, if it exceeds 3 parts by mass, the transparency of the pressure-sensitive adhesive film may be impaired, and the design of a synthetic resin molded body such as a conveyor handrail may become unclear.

The difference in refractive index of the particles from the refractive index of the resin composition (ΔR) is preferably 0.04 or less. When ΔR exceeds 0.04, the transparency of the pressure-sensitive adhesive film may be impaired, and the design of a molded body made of a synthetic resin such as a conveyor handrail may become unclear. The refractive index of the particles depends on the material used. For this reason, it is desirable to appropriately select the material of the particles in accordance with the refractive index of the resin composition to be employed.

Furthermore, the base material layer of the pressure-sensitive adhesive film according to the present invention can contain various additives as long as the physical properties thereof are not impaired. Specific examples of the additive include an antibacterial agent, a colorant, an antioxidant, a filler, an antiblocking agent, an antistatic agent, a flame retardant, an ultraviolet absorber, a lubricant, and a light stabilizer.

Specific examples of the antibacterial agent that can be added to the base material layer of the pressure-sensitive adhesive film according to the present invention include, for example, a mixed composite of silver, zinc, aluminum, other metals or alloys, metal oxide particles, and ceramic particles. And particles.

Specific examples of the colorant that can be added to the base material layer of the pressure-sensitive adhesive film according to the present invention include inorganic pigments, organic pigments, dyes, and the like.

Specific examples of the antioxidant that can be added to the base layer of the pressure-sensitive adhesive film according to the present invention include antioxidants such as hindered phenol compounds, phosphite compounds, and thioether compounds.

Specific examples of the ultraviolet absorber that can be added to the base material layer of the pressure-sensitive adhesive film according to the present invention include a benzophenone-based ultraviolet absorber and a benzotriazole-based ultraviolet absorber.

Specific examples of the lubricant that can be added to the base material layer of the pressure-sensitive adhesive film according to the present invention include, for example, fatty acid amides, paraffins, hydrocarbon resins, and fatty acids.

As a specific example of the light stabilizer that can be added to the base material layer of the pressure-sensitive adhesive film according to the present invention, for example, low basicity that can reduce and suppress the generation of a product due to an acid-base reaction with an ethylenically unsaturated carboxylic acid, Or a neutral high molecular weight type is mentioned.

The method for producing the base material layer of the pressure-sensitive adhesive film according to the present invention is not particularly limited, and a known method can be used. For example, each component is mixed using melt kneading and various mixing devices (single screw or twin screw extruder, roll, Banbury mixer, various kneaders, etc.), and the mixture is subjected to an inflation method, a T-die method, a calendar processing method. Etc., and can be formed on the film. When storing a base material layer in roll shape, it is preferable to provide a separator layer in order to prevent blocking between films.

The thickness of the base material layer of the pressure-sensitive adhesive film according to the present invention is not particularly limited, but is preferably 20 to 300 μm, particularly preferably 30 to 200 μm. By setting the thickness of the base material layer to 20 μm or more, sufficient wear resistance and discoloration resistance can be obtained. Moreover, it can be set as the film excellent in the construction workability | operativity to a molded object by the thickness of a base material layer being 300 micrometers or less.

The substrate layer of the pressure-sensitive adhesive film according to the present invention may be a single layer or may be laminated with another resin layer to form a multilayer film. Specific examples of the resin layer to be laminated include polyolefin resins such as polyethylene resins and polypropylene resins, such as styrene thermoplastic elastomers, olefin thermoplastic elastomers, polyester thermoplastic elastomers, polyurethane thermoplastic elastomers, and polyamides. Thermoplastic elastomers such as thermoplastic thermoplastic elastomers, vinylidene fluoride resins and the like.

The base material layer of the pressure-sensitive adhesive film according to the present invention can be provided with displays such as advertisements and guidance. By providing such a display, it can be affixed to a molded body to serve as an advertising medium or an information providing medium. For example, in order to provide the display on the base material layer, it is possible to perform printing on one side of the base material layer.

The printing method when printing on one side of the base material layer is not particularly limited, and printing methods such as gravure printing, offset printing, screen printing, flexographic printing, and image formation such as inkjet method, electrostatic toner method, thermal transfer method, etc. The method can be used. Further, the ink used is not particularly limited.

At this time, for example, a white pigment can be added to the base layer of the adhesive film. Specific examples of white pigments include titanium-based white pigments such as titanium oxide, zinc-based white pigments such as zinc oxide and zinc sulfide, composite white pigments such as lithopone, magnesium silicate, magnesium oxide, calcium carbonate, and barium sulfate. Extender pigments and the like. These white pigments can be used alone or in combination of two or more.

Of these white pigments, titanium oxide is preferred. The crystal type of titanium oxide is not particularly limited, but a rutile type having a large refractive index and excellent concealability is more preferable.

The pressure-sensitive adhesive layer of the pressure-sensitive adhesive film according to the present invention is formed in order to make the pressure-sensitive adhesive film adhere to a molded body made of synthetic resin. The material of the pressure-sensitive adhesive layer is not particularly limited as long as the pressure-sensitive adhesive film according to the present invention can be brought into close contact with the molded body, but includes, for example, a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a butyl-based pressure-sensitive adhesive and the like. It can be. Among these, acrylic pressure-sensitive adhesives are suitable because they are easy to design for tackiness and removability. Moreover, when a butyl-type adhesive is stuck on the molded object which consists of a material containing an amine type anti-aging agent, discoloration of a base material layer can further be suppressed. Moreover, you may mix | blend various additives, such as a tackifier, anti-aging agent, and a hardening | curing agent, as needed.

Specific examples of the acrylic pressure-sensitive adhesive include a homopolymer of (meth) acrylic acid ester or a copolymer with a copolymerizable monomer. Specific examples of (meth) acrylic acid esters include (meth) acrylic acid alkyl esters such as methyl ester, ethyl ester, butyl ester, 2-ethylhexyl ester, octyl ester, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, etc. (Meth) acrylic acid alkylaminoalkyl ester, (meth) acrylic acid glycidyl ester, (meth) acrylic acid, itaconic acid, maleic anhydride, (meth) acrylic acid amide, (meth) acrylic acid N-hydroxyamide, etc. Can be mentioned. Specific examples of the copolymerizable monomer include vinyl acetate, styrene, acrylonitrile and the like.

Among these, as the main monomer, those having a glass transition temperature of −50 ° C. or lower of the homopolymer are preferable, and examples thereof include alkyl acrylate.

The tackifier can be selected in consideration of the softening point, compatibility with each component, etc., for example, terpene resin, rosin resin, hydrogenated rosin resin, coumarone / indene resin, styrenic resin, aliphatic And petroleum oil resins, alicyclic petroleum resins, terpene-phenol resins, xylene resins, other aliphatic hydrocarbon resins, and aromatic hydrocarbon resins. The softening point of the tackifier is preferably 65 to 130 ° C., particularly preferably an alicyclic saturated hydrocarbon resin of petroleum resin having a softening point of 65 to 130 ° C., a polyterpene resin having a softening point of 80 to 130 ° C., softening A glycerin ester of hydrogenated rosin having a point of 80 to 130 ° C. is preferable.

Examples of the curing agent used for the acrylic pressure-sensitive adhesive include an isocyanate curing agent, an epoxy curing agent, and an amine curing agent. These may be used singly or in combination of two or more.

Specific examples of the isocyanate curing agent include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4,4′-diisocyanate, Polyvalent isocyanate compounds such as diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, lysine isocyanate Is mentioned.

In the pressure-sensitive adhesive film according to the present invention, means for forming the pressure-sensitive adhesive layer on the base material layer is not particularly limited. For example, a pressure-sensitive adhesive solution composed of a pressure-sensitive adhesive, a tackifier, an anti-aging agent and the like is applied to one side of the base material layer. And a means for drying and a method in which a pressure-sensitive adhesive solution is previously applied to one side of a separator to be described later and dried and bonded to the base material layer.

The thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film according to the present invention can be appropriately set within a range not impairing the pressure-sensitive adhesiveness and handleability, but is preferably 5 to 50 μm, preferably 10 to 30 μm.

It is preferable to provide a separator layer on the surface of the adhesive layer of the adhesive film according to the present invention. By providing a separator layer on the surface of the adhesive layer, shrinkage of the base material layer can be prevented, and wrinkles and peeling during coating can be prevented. Moreover, the handling at the time of constructing an adhesive film to a molded object becomes easy, and workability improves.

<Laminated body>
The laminated body which concerns on this invention has the adhesive film which concerns on this invention mentioned above, and the synthetic resin molded object laminated | stacked on this adhesive film.

The molded body is not particularly limited as long as the adhesive film can be attached thereto, and examples thereof include a rod shape, a plate shape, and a housing. Specific examples include handrails in hallways, conveyor handrails, home appliances, and automobiles.

Synthetic resins constituting the molded body include SBR rubber, urethane rubber, chlorosulfonated rubber, blended rubber of ethylene propylene diene rubber and styrene butadiene rubber, and blend rubber of ethylene propylene diene rubber and chlorosulfonated polyethylene rubber. Although it can be used, a resin containing an amine-based anti-aging agent as an anti-aging agent is particularly preferable. This is because the adhesive film according to the present invention is particularly difficult to cause discoloration when attached to a molded body containing an amine-based anti-aging agent.

The type of amine-based anti-aging agent used in the molded body of the laminate according to the present invention is not particularly limited, and any known amine-based anti-aging agent can be freely selected and used. For example, amine-ketone aging such as 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, a reaction product of diphenylamine and acetone Inhibitors: phenyl-1-naphthylamine, alkylated diphenylamine, octylated diphenylamine, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, p- (p-toluenesulfonylamido) diphenylamine, N, N′-di -2-Naphtyl-p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N- (1,3-dimethylbutyl) -N'- Phenyl-p-phenylenediamine, N-phenyl-N ′-(3-methacryloylio Aromatic secondary amine type antioxidants such as xyl-2-hydroxypropyl) -p-phenylenediamine; 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl- And monophenol-based anti-aging agents such as 4-ethylphenol and mono (or di- or tri) (α-methylbenzyl) phenol.

Of these, phenylenediamine-based antioxidants are particularly suitable in the present invention. This is because the adhesive film according to the present invention is particularly difficult to cause discoloration when attached to a molded body containing a phenylenediamine-based antioxidant. The pressure-sensitive adhesive film used in the present invention is excellent in discoloration resistance with respect to a p-phenylenediamine-based antioxidant, among other phenylenediamine-based antioxidants. Among the p-phenylenediamine-based anti-aging agents, the color fastness to 6C, 6DP, and 810NA is excellent, and particularly the color fastness to 6C is excellent.

The method of sticking the pressure-sensitive adhesive film according to the present invention to the molded body is not particularly limited, for example, a simple sticking jig for pressure-bonding to a conveyor handrail with a rubber roll, squeegee, etc. while peeling the separator layer provided on the surface of the pressure-sensitive adhesive layer It can be stuck by using.

<Method for protecting molded article>
The protection method according to the present invention is a method of protecting the molded body by adhering the above-described adhesive film according to the present invention to a molded body made of synthetic resin.

The molded body that can be protected by the protection method according to the present invention is not particularly limited as long as it is formed from the above-described synthetic resin. However, the protection method according to the present invention has a styrene-butadiene rubber and an amine-based anti-aging agent. Those formed from a synthetic resin can be particularly suitably protected.

In this case, it is possible to freely select and use the above-mentioned known amine-based anti-aging agent as the type of amine-based anti-aging agent. However, in the protection method according to the present invention, as the amine-based anti-aging agent, The molded body using the phenylenediamine-based antiaging agent can be particularly suitably protected.

Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to the following examples.

1. Study on resin to be contained in base material layer <Example 1: Production of adhesive film>
As an aromatic vinyl elastomer resin, a completely hydrogenated styrene-butadiene block copolymer (manufactured by Asahi Kasei Chemicals Corporation, Tuftec H1041: styrene content 30 mol%, conjugated diene monomer 70 mol%, hydrogenation rate 100%) 100 After dry blending parts by weight and 5 parts by weight of a white masterbatch (PEONY WHITEF-11060, manufactured by Dainippon Ink & Chemicals, Inc.), both sides were used using a single-screw T-die extruder having a laminating equipment with a screw diameter of 100 mm. A PET separator (manufactured by Toray Film Processing Co., Ltd., therapy _“ WD _” 110 μm) and a transparent aromatic vinyl elastomer resin film having a thickness of 80 μm were laminated to obtain a laminated film. An acrylic water-based pressure-sensitive adhesive and an epoxy-based cross-linking agent were previously applied to the aromatic vinyl elastomer resin side of the laminated film so that the thickness after drying was 20 μm, and dried paper separator 110 μm (manufactured by Sumika Kogyo Co., Ltd., SL- 80KCD7), a composite film having a double-sided PET separator 110 μm in the first layer, an aromatic vinyl elastomer resin film adhesive film 80 μm in the second layer, an acrylic water-based adhesive 20 μm in the third layer, and a paper separator 110 μm in the fourth layer Got. The 2% modulus of the pressure-sensitive adhesive film obtained by peeling off the first layer and the fourth layer, which are separators of the approximate composite film, was 0.8 MPa. Using this adhesive film, discoloration resistance, followability, and abrasion resistance were evaluated.

<Measurement of 2% modulus>
For the 2% modulus, a Tensilon tensile tester (Orientec, UCT-500) was used to stretch an adhesive film sample having a length of 25 mm in the horizontal direction and an interval of 100 mm in the vertical direction at a speed of 300 mm / min in the vertical direction. The tensile strength at an elongation of 2% was divided by the cross-sectional area of the sample.

<Evaluation of discoloration resistance>
Amine-based anti-aging agent 1 (manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., Nocrack 6C), amine-based anti-aging agent 2 (manufactured by Ouchi Shinsei Chemical Co., Ltd., No-Crack 6DP), amine-based anti-aging agent 3 (Ouchi Shinsei Chemical Industry Co., Ltd.) 80 μm-thick LDPE film prepared by dissolving 100 parts by weight and 25 parts by weight of acetone, respectively, and an amine-based anti-aging agent 4 (manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., No-Crack PA) and coating them to a thickness of 8 μm. Produced. Adhesive film samples from which the first and fourth layers, which are the separators of the composite film, are peeled off, are bonded to the LDPE film, and the fluorescence for 10 hours a day is placed in an evaluation test room at 23 ± 2 ° C. and 50 ± 5% RH It was left for 20 days under lamp irradiation. The change in color before and after standing was measured using a spectrocolorimeter (Konica Minolta, CM-2500D). The color difference ΔE ^* ab was calculated based on Equation (1) from L ^* (lightness), a ^* (chromaticity), and b ^* (chromaticity) measured in the Lab color system.

Also, the superiority or inferiority was evaluated according to the criteria shown in Table 1 below.

<Evaluation of trackability>
A laminated adhesive film obtained by further laminating a light-transmitting protective layer on the adhesive film sample from which the first and fourth layers, which are separators of the composite film, are peeled off, and an SBR conveyor handrail as an example of a synthetic resin molding. The surface condition after 30 days of operation was visually observed, and the superiority or inferiority was evaluated according to the criteria shown in Table 2 below.
The light-transmitting protective layer is a transparent adhesive film obtained by laminating a base film and an adhesive film, and one prepared by the following procedure was used.

(1) Production of Base Film Aromatic vinyl elastomer resin used for the base layer is a completely hydrogenated styrene-butadiene random copolymer (S.O.S. SS9000 made by Asahi Kasei Chemicals Co., Ltd .: 70 mol styrene content) %, Conjugated diene monomer 30 mol%, hydrogenation rate 100%) A transparent substrate film having a thickness of 50 μm was prepared by the T-die method. When producing a film by the T-die method, a desired base film was laminated on one side of a separator made of polyethylene terephthalate (manufactured by Toray Film Processing Co., Ltd., therapy “WD” 38 μm) for the purpose of preventing blocking.

(2) Preparation of pressure-sensitive adhesive film As the pressure-sensitive adhesive composition, an acrylic water-based pressure-sensitive adhesive and an epoxy-based cross-linking agent were adopted, and the base film prepared above and a paper separator (manufactured by Sumika Kogyo Co., Ltd., SL-80KCD7 110 μm) were used. A pressure-sensitive adhesive film having a pressure-sensitive adhesive layer thickness of 20 μm was produced by the transfer coating method used.
When actually used as a protective layer, the pressure-sensitive adhesive film was used as an example of a synthetic resin-made molded body, after being attached to an SBR conveyor handrail, and then used by peeling off the polyethylene terephthalate separator described in (1).

<Abrasion resistance>
A laminated adhesive film obtained by further laminating a light-transmitting protective layer on the adhesive film sample from which the first and fourth layers, which are separators of the composite film, are peeled off. Affixed to the rail, the surface state after 30 days of operation was visually observed, and the superiority or inferiority was evaluated according to the criteria in Table 3 below.

<Example 2>
As an aromatic vinyl elastomer resin, a completely hydrogenated product of a styrene-butadiene random copolymer (manufactured by Asahi Kasei Chemicals Corporation, SOE SS9000: styrene content 70 mol%, conjugated diene monomer 30 mol%, hydrogenated) A pressure-sensitive adhesive film was obtained in the same manner as in Example 1 except that the rate was 100%. The 2% modulus was 0.8 MPa.
About the obtained adhesive film, it carried out similarly to Example 1, and evaluated discoloration resistance, followable | trackability, and abrasion resistance.

<Example 3>
500 kg of cyclohexane containing 150 ppm of tetrahydrofuran and 8 kg of styrene monomer were added to a reaction vessel having a volume of 1.3 m 3. Next, 1520 ml of a cyclohexane solution containing 10% of n-butyllithium was added. While maintaining the inside of the container at 80 ° C., 52.0 kg of styrene monomer and 10.0 kg of butadiene were added at a constant charging rate of 84 kg / h and 20 kg / h, respectively. Further, 54.0 kg of styrene monomer and 38.0 kg of butadiene were added at a constant charging rate of 60.5 kg / h and 40.3 kg / h, respectively. After the addition, the inside of the container was brought to 75 ° C., 63.6 kg of styrene monomer was added all at once, and the reaction was continued for 30 minutes while cooling. After completion of the reaction, the inside of the container was brought to 70 ° C., and the polymer solution was transferred to another container. 110 g of water was added thereto to deactivate the active end of anionic polymerization, and a polymer liquid containing a block copolymer was obtained.

Sumitizer GS manufactured by Sumitomo Chemical Co., Ltd. and IL manufactured by Chiba Specialty Chemicals Co., Ltd. were added as stabilizers to Knox 1076, and 0.40 parts by weight and 0.20 parts by weight per 100 parts by weight of the block copolymer, respectively. Dissolved. This was pre-concentrated and further degassed and extruded by a twin screw Oda type with a vacuum vent to obtain a styrene-butadiene random copolymer having a styrene content of 76 mol%. An adhesive film having a 2% modulus of 5 MPa was obtained in the same manner as in Example 1 except that this resin was used.
About the obtained adhesive film, it carried out similarly to Example 1, and evaluated discoloration resistance, followable | trackability, and abrasion resistance.

<Comparative Example 1>
A pressure-sensitive adhesive film as in Example 1 except that a styrene-butadiene copolymer (manufactured by Denki Kagaku Kogyo Co., Ltd., 12RN: styrene content 88 mol%, conjugated diene monomer 12 mol%) was used as the aromatic vinyl elastomer resin. Got. The 2% modulus was 12 MPa.
About the obtained adhesive film, it carried out similarly to Example 1, and evaluated discoloration resistance, followable | trackability, and abrasion resistance.

<Comparative example 2>
As an aromatic vinyl elastomer resin, a completely hydrogenated styrene-butadiene block copolymer (Asahi Kasei Chemicals, Tuftec H1221: Styrene content 12 mol%, conjugated diene monomer 88 mol%, hydrogenation rate 100%) An adhesive film was obtained in the same manner as in Example 1 except that it was used. The 2% modulus was 0.3 MPa.
About the obtained adhesive film, it carried out similarly to Example 1, and evaluated discoloration resistance, followable | trackability, and abrasion resistance.

<Comparative Example 3>
As a base material layer, a white polyurethane film (manufactured by Nippon Matai Co., Ltd., ESMER URS) is coated with an acrylic water-based pressure-sensitive adhesive and an epoxy-based cross-linking agent so that the thickness after drying is 20 μm and dried to 2% modulus. An adhesive film having a pressure of 0.8 MPa was obtained.
About the obtained adhesive film, it carried out similarly to Example 1, and evaluated discoloration resistance, followable | trackability, and abrasion resistance.

<Comparative example 4>
An adhesive film was obtained in the same manner as in Example 1 except that an olefinic thermoplastic elastomer (R-110E, manufactured by Prime Polymer Co., Ltd.) was used for the base material layer. The 2% modulus was 1.0 MPa.
About the obtained adhesive film, it carried out similarly to Example 1, and evaluated discoloration resistance, followable | trackability, and abrasion resistance.

<Comparative Example 5>
An adhesive film was obtained in the same manner as in Example 1 except that a vinyl chloride tape (manufactured by Denki Kagaku Kogyo Co., Ltd., harness tape white) was used as the base material layer. The 2% modulus was 1.0 MPa.
About the obtained adhesive film, it carried out similarly to Example 1, and evaluated discoloration resistance, followable | trackability, and abrasion resistance.

Table 4 shows the results of each example and comparative example.

The pressure-sensitive adhesive film according to the present invention is excellent in followability and abrasion resistance when adhered to a molded article, and even when adhered to a molded article made of a material containing an amine-based antioxidant, It was shown that it hardly occurs.

On the other hand, in Comparative Example 1 using an aromatic vinyl elastomer resin having a styrene content exceeding 76 mol%, as shown in Table 1, the followability was inferior.

Conversely, in Comparative Example 2 using an aromatic vinyl elastomer resin having a styrene content of less than 30 mol%, as shown in Table 1, the abrasion resistance was slightly inferior.

Further, in Comparative Examples 3 to 5 using a polyurethane film, an olefin-based thermoplastic elastomer, and a vinyl chloride tape, as shown in Table 1, the discoloration resistance, wear resistance, and followability were inferior, respectively.

From the above results, it was found that the adhesive film according to the present invention is preferably formed using an aromatic vinyl elastomer resin having a styrene content of 30 to 76 mol%.

2. Study on Particles to be Included in Base Material Layer A study was made on the particles to be contained in the base material layer of the adhesive film.

<Example 4>
(1) Preparation of base film As a aromatic vinyl elastomer resin used for the base layer, a completely hydrogenated styrene-butadiene random copolymer similar to Example 2 (manufactured by Asahi Kasei Chemicals, S.O.E. SS9000: Styrene content 70 mol%, conjugated diene monomer 30 mol%, hydrogenation rate 100%, refractive index 1.555) 100 parts by mass, refractive index 1.545, refractive index difference ΔR with soft resin is 0 1 part by mass of particles having a volume average particle diameter of 5 μm (manufactured by Sekisui Plastics Co., Ltd., Techpolymer MBX-S series) and transparent base having a thickness of 50 μm by the T-die method A material film was prepared. When producing a film by the T-die method, a separator made of polyethylene terephthalate (manufactured by Toray Film Processing Co., Ltd., therapy “WD” 38 μm) was laminated on one side of the base film for the purpose of preventing blocking.

(2) Preparation of pressure-sensitive adhesive film An acrylic water-based pressure-sensitive adhesive and an epoxy-based cross-linking agent were adopted as the pressure-sensitive adhesive composition, and a paper separator (SL-80KCD7 110 μm, manufactured by Sumika Kogyo Co., Ltd.) was applied to the base film prepared above. A pressure-sensitive adhesive film having a pressure-sensitive adhesive layer thickness of 20 μm was produced by the transfer coating method used.

The 2% elongation strength of the obtained adhesive film was 3.2 N / 10 mm. Using this pressure-sensitive adhesive film, stain resistance and transparency were evaluated and ten-point average roughness was measured by the methods described below.

<Stain resistance>
The obtained pressure-sensitive adhesive film was laminated with a pressure-sensitive adhesive film for printing, and the stain resistance when applied to a molded body was examined as follows. In addition, the adhesive film for printing used what was produced in the following procedures.

As an aromatic vinyl elastomer resin, a completely hydrogenated product of styrene-butadiene block copolymer (manufactured by Asahi Kasei Chemicals, S.O.S. SS9000: styrene content 70 mol%, conjugated diene monomer 30 mol%, hydrogenated) 100 parts by mass) and 1 part by mass of a white masterbatch (manufactured by Dainippon Ink & Chemicals, Inc., PEONY WHITE F-11060) were melt-kneaded. Then, using a double-sided PET separator (Toray Film Processing Co., Ltd., “WD”), the thickness after drying in advance is applied to one side of a transparent aromatic vinyl elastomer resin film having a thickness of 80 μm obtained by T-die molding. An acrylic water-based pressure-sensitive adhesive and an epoxy-based crosslinking agent were applied so as to have a thickness of 20 μm, and a dried paper separator 110 μm (SL-80KCD7, manufactured by Sumika Kogyo Co., Ltd.) was bonded to obtain a pressure-sensitive adhesive film for printing.

The obtained adhesive film was laminated with an adhesive film for printing, and this was adhered to a conveyor handrail of an escalator made by Hitachi. The color difference (ΔE ^* ab) after 3 weeks was measured for the white part by a spectrocolorimeter (Konica Minolta). CM-2500d), and the superiority or inferiority was evaluated according to the criteria shown in Table 5 below.

<Transparency>
"Transparency" measured the haze of the obtained adhesive film using the haze meter (NDH2000 by Nippon Denshoku Industries Co., Ltd.), and evaluated the superiority or inferiority according to the criteria shown in Table 6 below.

<10-point average roughness>
The “ten-point average roughness” was measured according to JIS B0601, using an adhesive film from which a surf coder manufactured by Kosaka Laboratory was obtained.

<Example 5>
A pressure-sensitive adhesive film was prepared in the same manner as in Example 4 except that Sekisui Plastics Kogyo Kogyo Co., Ltd. and Techpolymer MBX-S series having a volume average particle diameter of 5 μm were used as the particles for the base material layer. Using the obtained adhesive film, the stain resistance and transparency were evaluated and the ten-point average roughness was measured in the same manner as in Example 4.

<Example 6>
A pressure-sensitive adhesive film was produced in the same manner as in Example 4 except that Sekisui Plastics Kogyo Kogyo Co., Ltd. and Techpolymer MBX-S series having a volume average particle size of 20 μm were used as the particles for the substrate layer. Using the obtained adhesive film, the stain resistance and transparency were evaluated and the ten-point average roughness was measured in the same manner as in Example 4.

<Example 7>
A pressure-sensitive adhesive film was produced in the same manner as in Example 4 except that the amount of particles used in the base material layer was 0.1 parts by mass. Using the obtained adhesive film, the stain resistance and transparency were evaluated and the ten-point average roughness was measured in the same manner as in Example 4.

<Example 8>
A pressure-sensitive adhesive film was produced in the same manner as in Example 4 except that the amount of particles used in the base material layer was 2.5 parts by mass. Using the obtained adhesive film, the stain resistance and transparency were evaluated and the ten-point average roughness was measured in the same manner as in Example 4.

<Example 9>
A pressure-sensitive adhesive film was produced in the same manner as in Example 4 except that particles having a refractive index of 1.525 and a refractive index difference ΔR with a soft resin of 0.03 were used as the particles for the base material layer. Using the obtained adhesive film, the stain resistance and transparency were evaluated and the ten-point average roughness was measured in the same manner as in Example 4.

<Example 10>
A pressure-sensitive adhesive film was produced in the same manner as in Example 4 except that Sekisui Plastics Kogyo Kogyo Co., Ltd. and Techpolymer MBX-S series having a volume average particle diameter of 2 μm were used as the particles for the substrate layer. Using the obtained adhesive film, evaluation of stain resistance and transparency and measurement of 10-point average roughness were carried out in the same manner as in Example 4.

<Example 11>
A pressure-sensitive adhesive film was prepared in the same manner as in Example 4 except that Sekisui Plastics Kogyo Kogyo Co., Ltd. and Techpolymer MBX-S series having a volume average particle size of 30 μm were used as the particles for the substrate layer. Using the obtained adhesive film, the stain resistance and transparency were evaluated and the ten-point average roughness was measured in the same manner as in Example 4.

<Example 12>
A pressure-sensitive adhesive film was produced in the same manner as in Example 4 except that the amount of particles used in the base material layer was 0.05 parts by mass. Using the obtained adhesive film, the stain resistance and transparency were evaluated and the ten-point average roughness was measured in the same manner as in Example 4.

<Example 13>
A pressure-sensitive adhesive film was produced in the same manner as in Example 4 except that the amount of particles used in the base material layer was 4 parts by mass. Using the obtained adhesive film, the stain resistance and transparency were evaluated and the ten-point average roughness was measured in the same manner as in Example 4.

<Example 14>
A pressure-sensitive adhesive film was produced in the same manner as in Example 4 except that particles having a refractive index of 1.525 and a refractive index difference ΔR with a soft resin of 0.05 were used as particles used for the base material layer. Using the obtained adhesive film, the stain resistance and transparency were evaluated and the ten-point average roughness was measured in the same manner as in Example 4.

Table 7 shows the results of each example.

As shown in Table 7, pressure-sensitive adhesive films according to Examples 4 to 9 in which 0.08 to 3 parts by mass of particles having a volume average particle diameter of 4 to 25 μm and a difference from the refractive index of the soft resin of 0.04 or less are added. All of transparency, stain resistance and belt followability were good.

In contrast, the adhesive film according to Example 10 in which the added beads had an average particle diameter of less than 4 μm resulted in poor stain resistance.

Conversely, the pressure-sensitive adhesive film according to Example 11 in which the average particle diameter of the added beads exceeded 25 μm resulted in poor transparency.

Moreover, the adhesive film according to Example 12 in which the amount of beads added was less than 0.08 parts by mass resulted in poor stain resistance.

Conversely, the pressure-sensitive adhesive film according to Example 13 in which the amount of beads added exceeds 3 parts by mass resulted in poor transparency.

Furthermore, the adhesive film according to Example 14 in which the difference between the refractive index of the added beads and the refractive index of the soft resin exceeded 0.04 resulted in slightly inferior transparency.

From the above results, the volume average particle size of the added particles is preferably 4 to 25 μm, the added amount is preferably 0.08 to 3 parts by mass, and the refractive index of the added particles is It was found that the difference between the refractive index and the resin composition is preferably 0.04 or less.

The pressure-sensitive adhesive film according to the present invention is less likely to cause wrinkles or peeling by being attached to a synthetic resin molded body provided in a handrail in a corridor, a conveyor handrail, a home appliance, an automobile, etc. It is possible to protect the molded body in a state in which the base material hardly undergoes discoloration.

Claims (13)

1. A base layer and an adhesive layer;
   The pressure-sensitive adhesive film, wherein the resin composition forming the base material layer is an aromatic vinyl elastomer resin having a styrene content of 30 to 76 mol%.
2. The pressure-sensitive adhesive film according to claim 1, wherein the aromatic vinyl elastomer resin is a styrene-butadiene random copolymer and / or a styrene-butadiene random copolymer hydrogenated product.
3. The pressure-sensitive adhesive film according to claim 1 or 2, wherein the pressure-sensitive adhesive film has a 2% elongation strength of 1 to 10 N / 10 mm.
4. The pressure-sensitive adhesive film according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive film has a 2% modulus of 0.5 to 8 MPa.
5. The color difference ΔE ^* ab calculated by the following formula (1) between the hue measured in the Lab color system and the hue after 20 days under 23 ° C. and 50% RH measurement conditions of the adhesive film is 10 or less. The pressure-sensitive adhesive film according to any one of claims 1 to 4.
   

   

   (L ^* , a ^* , b ^* indicate the values of the L ^* , a ^* , b ^* axes in the Lab color system, respectively.
   ΔL ^* , Δa ^* , and Δb ^* indicate differences between L ^* , a ^* , and b ^* measured immediately after sample preparation and 20 days later, respectively. )
6. The pressure-sensitive adhesive film according to any one of claims 1 to 5, wherein a light-transmitting protective layer is provided on the surface of the base material layer.
7. The pressure-sensitive adhesive film according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive layer is made of an acrylic pressure-sensitive adhesive.
8. The pressure-sensitive adhesive film according to any one of claims 1 to 7, wherein the base material layer contains 100 parts by mass of a resin composition and 0.08 to 3 parts by mass of particles having a volume average particle diameter of 4 to 25 µm.
9. The pressure-sensitive adhesive film according to claim 8, wherein a difference in refractive index between the resin composition and particles contained in the resin composition is 0.04 or less.
10. The pressure-sensitive adhesive film according to any one of claims 1 to 9, and a synthetic resin-made molded body laminated on the pressure-sensitive adhesive film,
    A laminate in which an amine anti-aging agent is contained in the synthetic resin constituting the molded body.
11. The laminate according to claim 10, wherein the amine-based antioxidant is a phenylenediamine-based antioxidant.
12. A method for protecting a molded body for protecting the molded body by sticking an adhesive film to a molded body made of synthetic resin,
    The synthetic resin forming the molded body has a styrene butadiene rubber and an amine anti-aging agent,
    The protection method of the molded object whose said adhesive film is an adhesive film as described in any one of Claims 1-11.
13. The method for protecting a molded article according to claim 12, wherein the amine-based antioxidant is a phenylenediamine-based antioxidant.