JP7010846B2 - Surface protective film - Google Patents

Description

The present invention relates to an optical surface protective film with a separator. In particular, an optical surface protective film with a separator used for protecting the surface of an optical member (for example, a polarizing plate used for a liquid crystal display, a wave plate, a retardation plate, an optical compensation film, a reflective sheet, a brightness improving film, etc.) The position can be accurately adjusted with respect to the surface of the optical member, and by peeling off the separator after the position adjustment, the optical surface protective film can be attached to the surface of the optical member at an accurate position, which is useful.

The surface protective film generally has a structure in which an adhesive layer is provided on a film-like base film (support). The surface protective film is attached to an optical member which is an adherend via the adhesive layer, and is used for the purpose of protecting the optical member from scratches and stains on the surface during processing, transportation, inspection, and the like. Be done. For example, a panel of a liquid crystal display is formed by bonding an optical member such as a polarizing plate or a wave plate to a liquid crystal cell via an adhesive layer. The pressure-sensitive adhesive layer is protected and stored by a release-treated separator or the like from the need to protect it from drying or the like until it is actually attached to the optical member (Patent Document 1).

Then, after the surface of the pressure-sensitive adhesive layer of the surface-protecting film is actually attached to the optical member and used, the surface-protecting film is peeled off and removed when it is no longer needed.

JP 2012-224811

Further, when the surface protective film with a separator is bonded to the surface of the optical member, only the surface protective film is cut to a desired size so as not to cut the separator in order to bond the surface protective film at an accurate position. A hole is made in the outer edge of the film, the perforated portion is detected by a sensor, the position is adjusted using an automatic bonding machine, and then the separator is peeled off and then bonded to the surface of the optical member.

However, even if an attempt is made to accurately adjust the position on the optical member using a surface protective film with a transparent separator that is normally used, the perforated portion cannot be accurately detected, causing misalignment, and the surface protective film with a separator. When the separator is peeled off and attached to the optical member, problems such as the inability to attach the separator at an accurate position occur, which causes a problem.

Therefore, as a result of diligent research in view of the above circumstances, the present inventors adjusted the position of the optical surface protective film with a separator on the optical member by using an automatic laminating machine, and after the separator was peeled off, on the surface of the optical member. It is an object of the present invention to provide an optical surface protective film with a separator, which has excellent position adjustability based on a separator and can be attached to the surface of an optical member at an accurate position at the time of bonding.

That is, the optical surface protective film with a separator of the present invention is an optical surface protective film having an adhesive layer on at least one side of the base film, and the surface of the pressure-sensitive adhesive layer opposite to the surface in contact with the base film . , An optical surface protective film with a separator having a separator, wherein the separator has a release layer and a base material, the haze of the separator is 90% or more, and the total light transmittance is 50% or less. It is characterized by that.

In the optical surface protective film with a separator of the present invention, it is preferable that the base film is a polyester film.

The optical surface protective film with a separator of the present invention is formed from a pressure-sensitive adhesive composition in which the pressure-sensitive adhesive layer contains at least one selected from an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive. It is preferable to be done.

In the present invention, by using a separator having specific optical characteristics, the position of the optical surface protective film with a separator is adjusted with respect to the surface of the optical member by using an automatic bonding machine, and after the separator is peeled off, the surface of the optical member is adjusted. It is useful because it is possible to obtain an optical surface protective film with a separator, which has excellent position adjustability based on a separator and can be attached to the surface of an optical member at an accurate position.

It is a schematic cross-sectional view which shows one structural example of the optical surface protection film with a separator which concerns on this invention. It is a schematic cross-sectional view which shows one structural example when the position of the optical surface protective film with a separator which concerns on this invention is adjusted on an optical member.

Hereinafter, embodiments of the present invention will be described in detail.

<Overall structure of optical surface protective film with separator>
The optical surface protective film with a separator disclosed herein (hereinafter, may be simply referred to as “surface protective film”) is generally referred to as an adhesive tape, an adhesive label, an adhesive film, or the like. Is protected by a separator, and in particular, surface protection that protects the surface of optical components during processing, inspection, and transportation of optical components (for example, optical components used as components of liquid crystal display panels such as polarizing plates and wavelength plates). Suitable as a film. The pressure-sensitive adhesive layer in the surface protective film is typically formed continuously, but is not limited to such a form, and is formed in a regular or random pattern such as a dot shape or a striped shape. It may be a pressure-sensitive adhesive layer. Further, the surface protective film disclosed herein may be in the form of a roll or may be in the form of a single leaf.

<Base film>
The optical surface protective film with a separator of the present invention is characterized by having a base film. In the technique disclosed herein, the resin material constituting the base film can be used without particular limitation, and for example, transparency, mechanical strength, thermal stability, moisture shielding property, isotropic property, etc. can be used. It is preferable to use one having excellent characteristics such as flexibility and dimensional stability. In particular, since the base film has flexibility, the pressure-sensitive adhesive composition can be applied by a roll coater or the like, and can be wound into a roll shape, which is useful.

As the base film (support), for example, polyester polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate; cellulose polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate polymers; The base material is a plastic film composed of a resin material containing an acrylic polymer such as polymethylmethacrylate; or the like as a main resin component (main component of the resin component, typically a component occupying 50% by weight or more). It can be preferably used as a film. Other examples of the resin material include styrene polymers such as polystyrene and acrylonitrile-styrene copolymers; olefin polymers such as polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, and ethylene-propylene copolymers; Examples thereof include those using a vinyl chloride polymer; an amide polymer such as nylon 6, nylon 6, 6 and aromatic polyamide; as a resin material. Still other examples of the resin material include imide-based polymers, sulfone-based polymers, polyether sulfone-based polymers, polyether ether ketone-based polymers, polyphenylene sulfide-based polymers, vinyl alcohol-based polymers, vinylidene chloride-based polymers, and vinyl butyral-based polymers. , Arilate-based polymer, polyoxymethylene-based polymer, epoxy-based polymer and the like. It may be a base film composed of two or more kinds of blends of the above-mentioned polymers.

As the base film, a plastic film made of a transparent thermoplastic resin material can be preferably adopted. Among the plastic films, it is more preferable to use a polyester film. Here, the polyester film mainly contains a polyester polymer material (polyester resin) having a main skeleton based on an ester bond such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate. Say something. Such a polyester film has preferable properties as a base film of a surface protective film, such as excellent optical properties and dimensional stability.

If necessary, the resin material constituting the base film may contain various additives such as antioxidants, ultraviolet absorbers, plasticizers, and colorants (pigments, dyes, etc.). For example, known or conventional surface treatments such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, and application of an undercoat agent may be applied. Such a surface treatment may be, for example, a treatment for enhancing the adhesion between the base film and the pressure-sensitive adhesive layer (the anchoring property of the pressure-sensitive adhesive layer).

As the base film, it is also possible to use a plastic film which has been subjected to antistatic treatment. It is preferable to use the base film because the charge of the surface protective film itself at the time of peeling is suppressed. Further, the base film is a plastic film, and by applying the antistatic treatment to the plastic film, it is possible to reduce the charge of the surface protective film itself and obtain an excellent antistatic ability to the adherend. The method for imparting the antistatic function is not particularly limited, and a conventionally known method can be used. For example, an antistatic resin, a conductive polymer, or a conductive substance composed of an antistatic agent and a resin component can be used. Examples thereof include a method of applying the contained conductive resin, a method of depositing or plating a conductive substance, and a method of kneading an antistatic agent or the like.

The thickness of the base film is usually about 5 to 200 μm, preferably about 10 to 100 μm. When the thickness of the base film is within the above range, it is preferable because it is excellent in the workability of attaching to the adherend, the peelability from the adherend, and the workability.

The surface protective film disclosed herein may be implemented in an embodiment including a base film, an adhesive layer, and a separator in addition to the other layers. Examples of the other layer include an antistatic layer and an undercoat layer (anchor layer) that enhances the anchoring property of the pressure-sensitive adhesive layer.

<Adhesive layer>
The pressure-sensitive adhesive layer used in the present invention can be used without particular limitation as long as it is formed of a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive polymer having adhesiveness. As the pressure-sensitive adhesive composition, for example, an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a synthetic rubber-based pressure-sensitive adhesive, a natural rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, and the like can be used. , Acrylic adhesives, urethane adhesives, and silicone adhesives are preferably used (containing) at least one selected from the group, and particularly preferably the adhesive polymer (meth). It is to use an acrylic adhesive that uses an acrylic polymer.

When the pressure-sensitive adhesive layer uses an acrylic pressure-sensitive adhesive, the (meth) acrylic-based polymer, which is a pressure-sensitive adhesive polymer constituting the acrylic pressure-sensitive adhesive, is an alkyl having 1 to 14 carbon atoms as a raw material monomer constituting the (meth) acrylic polymer. A (meth) acrylic monomer having a group can be used as the main monomer. As the (meth) acrylic monomer, one kind or two or more kinds can be used. By using the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms, it becomes easy to control the peeling force (adhesive force) to the adherend (protected body) to be low, and light peeling becomes possible. A surface protective film having excellent properties and removability can be obtained. The (meth) acrylic polymer in the present invention means an acrylic polymer and / or a methacrylic polymer, and the (meth) acrylate means an acrylate and / or a methacrylate.

Specific examples of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and s-butyl (meth). ) Acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl ( Examples include meta) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, and n-tetradecyl (meth) acrylate. Be done.

In particular, in the surface protective film of the present invention, n-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, and isooctyl (meth) acrylate , N-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth). ) A (meth) acrylic monomer having an alkyl group having 4 to 14 carbon atoms such as acrylate is preferable. In particular, by using a (meth) acrylic monomer having an alkyl group having 4 to 14 carbon atoms, it becomes easy to control the peeling force (adhesive force) to the adherend to be low, and the material has excellent re-peelability. Will be.

In particular, it is preferable to contain 65% by weight or more of the (meth) acrylic monomer having an alkyl group having 1 to 14 carbon atoms with respect to 100% by weight of the total amount of the monomer components constituting the (meth) acrylic polymer. , More preferably 75% by weight or more, still more preferably 85 to 99.9% by weight, and most preferably 90 to 99% by weight. If it is less than 65% by weight, the appropriate wettability of the pressure-sensitive adhesive composition and the cohesive force of the pressure-sensitive adhesive layer are deteriorated, which is not preferable.

Further, as the (meth) acrylic polymer, a hydroxyl group-containing (meth) acrylic monomer can be used as the raw material monomer. As the hydroxyl group-containing (meth) acrylic monomer, one kind or two or more kinds can be used. By using the hydroxyl group-containing (meth) acrylic monomer, it becomes easier to control cross-linking of the pressure-sensitive adhesive composition, and by extension, a balance between improvement of wettability due to flow and reduction of peeling force (adhesive force) in peeling is achieved. It becomes easier to control.

Examples of the hydroxyl group-containing (meth) acrylic monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxyhexyl (meth) acrylate. , 8-Hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl acrylate, N-methylol (meth) acrylamide, and the like. ..

The hydroxyl group-containing (meth) acrylic monomer is preferably contained in an amount of 25% by weight or less, more preferably 15% by weight or less, based on 100% by weight of the total amount of the monomer components constituting the (meth) acrylic polymer. More preferably, it is 0.1 to 10% by weight. When it is within the above range, it is easy to control the balance between the wettability of the pressure-sensitive adhesive composition and the cohesive force of the obtained pressure-sensitive adhesive layer, which is preferable.

In addition, as other polymerizable monomer components, the Tg is set to 0 ° C. or lower (usually -100 ° C. or higher) so that the adhesive performance can be easily balanced, and the glass transition temperature and peeling of the (meth) acrylic polymer are set. A polymerizable monomer for adjusting the property can be used as long as the effect of the present invention is not impaired.

Further, as the (meth) acrylic polymer, a carboxyl group-containing (meth) acrylic monomer can be used as the raw material monomer. By using the carboxyl group-containing (meth) acrylic monomer, it is possible to suppress an increase in the adhesive force of the pressure-sensitive adhesive layer (surface protective film) over time, and it is possible to suppress the increase in the adhesive force over time, and the re-peelability, the property of preventing the increase in the adhesive force, and the work. Excellent in sex. Further, it is preferable because it has excellent shearing force as well as cohesive force of the pressure-sensitive adhesive layer.

Examples of the carboxyl group-containing (meth) acrylic monomer include (meth) acrylic acid, carboxylethyl (meth) acrylate, and carboxylpentyl (meth) acrylate.

The amount of the carboxyl group-containing (meth) acrylic monomer is preferably 10% by weight or less, preferably 0 to 8% by weight, based on 100% by weight of the total amount of the monomer components constituting the (meth) acrylic polymer. Is more preferable, and 0 to 6% by weight is further preferable. When it is within the above range, it is easy to control the balance between the wettability of the pressure-sensitive adhesive composition and the cohesive force of the obtained pressure-sensitive adhesive layer, which is preferable.

Further, as the (meth) acrylic polymer, other polymerizable monomers other than the raw material monomer can be used without particular limitation as long as the characteristics of the present invention are not impaired. For example, as the other polymerizable monomer, a cohesive force / heat resistance improving component such as a cyano group-containing monomer, a vinyl ester monomer, and an aromatic vinyl monomer, an amide group-containing monomer, an imide group-containing monomer, an amino group-containing monomer, and an epoxy A group-containing monomer, N-acryloylmorpholine, vinyl ether monomer and other components having a functional group that acts as an improvement in peeling power (adhesive power) and a cross-linking base point can be appropriately used. Among them, it is preferable to use a cyano group-containing monomer, an amide group-containing monomer, an imide group-containing monomer, an amino group-containing monomer, and a nitrogen-containing monomer such as N-acryloylmorpholine. By using the nitrogen-containing monomer, it is possible to secure an appropriate peeling force (adhesive force) that does not cause floating or peeling, and it is possible to obtain a surface protective film having excellent shearing force, which is useful. As these polymerizable monomers, one kind or two or more kinds can be used.

Examples of the cyano group-containing monomer include acrylonitrile and methacrylonitrile.

Examples of the amide group-containing monomer include acrylamide, methacrylamide, diethylacrylamide, N-vinylpyrrolidone, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N, N-diethylacrylamide, N, N-diethyl. Examples thereof include methacrylamide, N, N'-methylenebisacrylamide, N, N-dimethylaminopropylacrylamide, N, N-dimethylaminopropylmethacrylamide, and diacetoneacrylamide.

Examples of the imide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, and itaconimide.

Examples of the amino group-containing monomer include aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate and the like.

Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, vinyl laurate and the like.

Examples of the aromatic vinyl monomer include styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene, and other substituted styrenes.

Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, and allyl glycidyl ether.

Examples of the vinyl ether monomer include methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether and the like.

In the present invention, the other polymerizable monomer is preferably 0 to 30% by weight, preferably 0 to 10% by weight, based on 100% by weight of the total amount of the monomer components constituting the (meth) acrylic polymer. Is more preferable. The other polymerizable monomers can be appropriately adjusted to obtain the desired properties.

The (meth) acrylic polymer may further contain an alkylene oxide group-containing reactive monomer as a monomer component.

The average number of moles of oxyalkylene units added to the alkylene oxide group-containing reactive monomer is preferably 1 to 40, preferably 3 to 40, from the viewpoint of compatibility with the oxyalkylene group-containing compound. Is more preferable, 4 to 35 is more preferable, and 5 to 30 is particularly preferable. When the average number of added moles is 1 or more, the effect of reducing contamination of the adherend (protected body) tends to be efficiently obtained. Further, when the average number of added moles is larger than 40, the interaction with the oxyalkylene group-containing compound is large, and the viscosity of the pressure-sensitive adhesive composition tends to increase, which tends to make coating difficult, which is not preferable. The terminal of the oxyalkylene chain may remain as a hydroxyl group or may be substituted with another functional group or the like.

The alkylene oxide group-containing reactive monomer may be used alone or in combination of two or more, but the total content is the total amount of the monomer components of the (meth) acrylic polymer. Medium, 0 to 20% by weight is preferable, and 0 to 10% by weight is more preferable. If the content of the alkylene oxide group-containing reactive monomer exceeds 20% by weight, the contamination with the adherend deteriorates, which is not preferable.

Examples of the oxyalkylene unit of the alkylene oxide group-containing reactive monomer include those having an alkylene group having 1 to 6 carbon atoms, and examples thereof include an oxymethylene group, an oxyethylene group, an oxypropylene group and an oxybutylene group. Be done. The hydrocarbon group of the oxyalkylene chain may be linear or branched.

Further, it is more preferable that the alkylene oxide group-containing reactive monomer is a reactive monomer having an ethylene oxide group. By using a reactive monomer-containing (meth) acrylic polymer having an ethylene oxide group as the base polymer, the compatibility between the base polymer and the oxyalkylene group-containing compound is improved, and bleeding to the adherend is suitably suppressed. A low-contamination pressure-sensitive adhesive composition is obtained.

Examples of the alkylene oxide group-containing reactive monomer include a (meth) acrylic acid alkylene oxide adduct and a reactive surfactant having a reactive substituent such as an acryloyl group, a methacryloyl group, or an allyl group in the molecule. can give.

Specific examples of the (meth) acrylic acid alkylene oxide adduct include polyethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, and polyethylene glycol-polybutylene glycol (meth). ) Acrylic, Polyethylene Glycol-Polybutylene Glycol (Meta) Acrylic, methoxypolyethylene Glycol (Meta) acrylate, ethoxypolyethylene Glycol (Meta) acrylate, Butoxypolyethylene Glycol (Meta) acrylate, Octoxypolyethylene glycol (Meta) acrylate, Lauroxypolyethylene Glycol (meth) acrylate, stearoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, octoxypolyethylene glycol-polypropylene glycol (meth) acrylate and the like can be mentioned.

Specific examples of the reactive surfactant include, for example, an anionic reactive surfactant having a (meth) acryloyl group or an allyl group, a nonionic reactive surfactant, a cationic reactive surfactant, and the like. Can be given.

The (meth) acrylic polymer preferably has a weight average molecular weight (Mw) of 100,000 to 5 million, more preferably 200,000 to 4 million, still more preferably 300,000 to 3 million, and most preferably 300,000 to 1.2 million. Is. When the weight average molecular weight is less than 100,000, the cohesive force of the pressure-sensitive adhesive layer becomes small, which tends to cause adhesive residue. On the other hand, when the weight average molecular weight exceeds 5 million, the fluidity of the polymer is lowered, the wettability to the adherend (for example, a polarizing plate) is insufficient, and the adherend and the pressure-sensitive adhesive layer of the surface protective film are formed. Tends to cause blisters that occur during. The weight average molecular weight is obtained by measuring by GPC (gel permeation chromatography).

The glass transition temperature (Tg) of the (meth) acrylic polymer is preferably 0 ° C. or lower, more preferably −10 ° C. or lower (usually −100 ° C. or higher). When the glass transition temperature is higher than 0 ° C., the polymer does not easily flow, for example, the polarizing plate, which is an optical member, is not sufficiently wetted, and the blisters generated between the polarizing plate and the pressure-sensitive adhesive layer of the surface protective film. Tends to be the cause. In particular, the glass transition temperature is preferably −40 ° C. or lower, more preferably −70 ° C. or lower, so that a pressure-sensitive adhesive layer having excellent wettability to a polarizing plate and light peelability can be easily obtained. The glass transition temperature of the (meth) acrylic polymer can be adjusted within the above range by appropriately changing the monomer component and the composition ratio to be used.

The polymerization method of the (meth) acrylic polymer is not particularly limited and can be polymerized by known methods such as solution polymerization, emulsion polymerization, bulk polymerization and suspension polymerization, but in particular from the viewpoint of workability and subject matter. Solution polymerization is a more preferable embodiment from the viewpoint of characteristics such as low contamination of the body (protected body). Further, the obtained polymer may be any of a random copolymer, a block copolymer, an alternate copolymer, a graft copolymer and the like.

When a urethane-based pressure-sensitive adhesive is used for the pressure-sensitive adhesive layer, any suitable urethane-based pressure-sensitive adhesive may be adopted. Examples of such urethane-based pressure-sensitive adhesives include those made of urethane-based polymers, which are adhesive polymers obtained by reacting a polyol with a polyisocyanate compound. Examples of the polyol include a polyether polyol, a polyester polyol, a polycarbonate polyol, a polycaprolactone polyol, and the like. Examples of the polyisocyanate compound include diphenylmethane diisocyanate, tolylene diisocyanate, and hexamethylene diisocyanate.

When a silicone-based pressure-sensitive adhesive is used for the pressure-sensitive adhesive layer, any suitable silicone-based pressure-sensitive adhesive may be adopted. As such a silicone-based pressure-sensitive adhesive, preferably, one obtained by blending or aggregating a silicone-based polymer which is an adhesive polymer can be adopted.

Examples of the silicone-based pressure-sensitive adhesive include addition reaction-curable silicone-based pressure-sensitive adhesives and peroxide-curable silicone-based pressure-sensitive adhesives. Among these silicone-based pressure-sensitive adhesives, addition reaction-curable silicone-based pressure-sensitive adhesives are preferable because they do not use peroxides (benzoyl peroxide or the like) and do not generate decomposition products.

As the curing reaction of the addition reaction curing type silicone-based pressure-sensitive adhesive, for example, in the case of obtaining a polyalkyl silicone-based pressure-sensitive adhesive, a method of curing a polyalkyl hydrogen siloxane composition with a platinum catalyst can be generally mentioned.

<Oxyalkylene group-containing compound>
The pressure-sensitive adhesive composition used in the present invention can also contain an oxyalkylene group-containing compound. By containing an oxyalkylene group-containing compound, it is possible to further develop light peelability. Examples of the oxyalkylene group-containing compound include an organopolysiloxane having an oxyalkylene chain and an oxyalkylene group-containing compound containing no organopolysiloxane.

As a specific example of the organopolysiloxane having an oxyalkylene chain, as a specific example of an organopolysiloxane having an oxyalkylene chain in the main chain, for example, as a commercial product, the trade names are X-22-4952 and X-22. -4272, X-22-6266, KF-6004, KF-889 (above, manufactured by Shin-Etsu Chemical Co., Ltd.), BY16-201, SF8427 (above, manufactured by Toray Dow Corning), IM22 (manufactured by Asahi Kasei Wacker), etc. Can be given. Examples of the organosiloxane having an oxyalkylene chain on the side chain include commercially available products with trade names KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, and KF-945. , KF-640, KF-642, KF-643, KF-6022, X-22-6191, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017, X-22-2516 (The above is manufactured by Shin-Etsu Chemical Co., Ltd.) SF8428, FZ-2162, SH3749, FZ-77, L-7001, FZ-2104, FZ-2110, L-7002, FZ-2122, FZ-2164, FZ-2203, FZ -7001, SH8400, SH8700, SF8410, SF8422 (all manufactured by Toray Dow Corning), TSF-4440, TSF-4441, TSF-4445, TSF-4450, TSF-4446, TSF-4452, TSF-4460 (momentive) Performance Materials), BYK-333, BYK-307, BYK-377, BYK-UV3500, BYK-UV3570 (manufactured by Big Chemie Japan) and the like. These compounds may be used alone or in combination of two or more.

Specific examples of the oxyalkylene group-containing compound containing no organopolysiloxane include polyoxyalkylene alkylamine, polyoxyalkylenediamine, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, and polyoxyalkylene alkylphenyl ether. , Polyoxyalkylene alkyl ether, polyoxyalkylene alkyl allyl ether, polyoxyalkylene alkyl phenyl allyl ether and other nonionic surfactants; polyoxyalkylene alkyl ether sulfate ester salt, polyoxyalkylene alkyl ether phosphate ester salt, poly Anionic surfactants such as oxyalkylene alkyl phenyl ether sulfate ester salts and polyoxyalkylene alkyl phenyl ether phosphate ester salts; in addition, cationic surfactants having a polyoxyalkylene chain (polyalkylene oxide chain) and amphoteric Examples thereof include a surfactant, a polyether compound having a polyoxyalkylene chain (including a derivative thereof), an acrylic compound having a polyoxyalkylene chain (including a derivative thereof), and the like. Further, the polyoxyalkylene chain-containing monomer may be blended as the polyoxyalkylene chain-containing compound. The polyoxyalkylene chain-containing compound may be used alone or in combination of two or more.

Specific examples of the polyether compound (polyether component) having a polyoxyalkylene chain include a block copolymer of polypropylene glycol (PPG) -polyethylene glycol (PEG), a block copolymer of PPG-PEG-PPG, and the like. Examples thereof include a block copolymer of PEG-PPG-PEG. Examples of the derivative of the polyether compound having a polyoxyalkylene chain include an oxypropylene group-containing compound having an etherified terminal (PPG monoalkyl ether, PEG-PPG monoalkyl ether, etc.) and an oxypropylene having an acetylated terminal. Group-containing compounds (terminal acetylated PPG, etc.), and the like can be mentioned.

Further, specific examples of the acrylic compound having a polyoxyalkylene chain include a (meth) acrylate polymer having an oxyalkylene group. As the oxyalkylene group, the number of added moles of the oxyalkylene unit is preferably 1 to 50, more preferably 2 to 30, and even more preferably 2 to 20. Further, the terminal of the oxyalkylene chain may remain as a hydroxyl group or may be substituted with an alkyl group, a phenyl group or the like.

The (meth) acrylate polymer having an oxyalkylene group is preferably a polymer containing (meth) acrylate alkylene oxide as a monomer component, and specific examples of the (meth) acrylate alkylene oxide are ethylene. Examples of the glycol group-containing (meth) acrylate include methoxy-polyethylene glycol (meth) acrylate type such as methoxy-diethylene glycol (meth) acrylate and methoxy-triethylene glycol (meth) acrylate, ethoxy-diethylene glycol (meth) acrylate, and ethoxy. -Ethoxy-polyethylene glycol (meth) acrylate type such as triethylene glycol (meth) acrylate, butoxy-polyethylene glycol (meth) acrylate type such as butoxy-diethylene glycol (meth) acrylate, butoxy-triethylene glycol (meth) acrylate, phenoxy -Phenoxy-polyethylene glycol (meth) acrylate type such as diethylene glycol (meth) acrylate and phenoxy-triethylene glycol (meth) acrylate, 2-ethylhexyl-polyethylene glycol (meth) acrylate, nonylphenol-polyethylene glycol (meth) acrylate type, methoxy -Methoxy-polypropylene glycol (meth) acrylate type such as dipropylene glycol (meth) acrylate can be mentioned.

Further, as the monomer component, other monomer components other than the (meth) acrylic acid alkylene oxide can also be used. Specific examples of other monomer components include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, and isobutyl (meth) acrylate. , Hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate , Isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate and other acrylates having an alkyl group having 1 to 14 carbon atoms and / or methacrylate. Be done.

Further, as other monomer components other than the (meth) acrylic acid alkylene oxide, a carboxyl group-containing (meth) acrylate, a phosphoric acid group-containing (meth) acrylate, a cyano group-containing (meth) acrylate, vinyl esters, and aromatic vinyl compounds. , Acid anhydride group-containing (meth) acrylate, hydroxyl group-containing (meth) acrylate, amide group-containing (meth) acrylate, amino group-containing (meth) acrylate, epoxy group-containing (meth) acrylate, N-acryloyl morpholine, vinyl ethers Etc. can be used as appropriate.

In a more preferred embodiment, the polyoxyalkylene chain-containing compound containing no organopolysiloxane is a compound having at least a part (poly) ethylene oxide chain. By blending the (poly) ethylene oxide chain-containing compound, the compatibility with the base polymer is improved, bleeding to the adherend is suitably suppressed, and a low-contamination pressure-sensitive adhesive composition can be obtained. Above all, when a block copolymer of PPG-PEG-PPG is used, a pressure-sensitive adhesive having excellent low contamination property can be obtained. As the polyethylene oxide chain-containing compound, the weight of the (poly) ethylene oxide chain in the entire polyoxyalkylene chain-containing compound containing no organopolysiloxane is preferably 5 to 90% by weight, more preferably 5 to 85%. By weight%, more preferably 5 to 80% by weight, most preferably 5 to 75% by weight.

Further, as commercially available products of the polyoxyalkylene chain-containing compound containing no organopolysiloxane, for example, ADEKA PLRONIC 17R-4, ADEKA PLLONIC 25R-2 (all manufactured by ADEKA), Latemul PD-420, Latemul PD. -420, Latemuru PD-450, Emargen 120 (manufactured by Kao), Aqualon HS-10, KH-10, Neugen EA-87, EA-137, EA-157, EA-167, EA-177 (above, Daiichi) (Manufactured by Industrial Pharmaceutical Co., Ltd.) and the like.

The content of the oxyalkylene group-containing compound is 100 parts by weight of the adhesive polymer (main polymer, for example, (meth) acrylic polymer, urethane polymer, silicone polymer, etc.) constituting the pressure-sensitive adhesive composition. It is preferably 0.01 to 5 parts by weight, more preferably 0.02 to 2 parts by weight, still more preferably 0.03 to 1.6 parts by weight, and most preferably 0.1 to 0.8 parts by weight. It is a department. When it is within the above range, the pressure-sensitive adhesive layer (surface protective film) used in the present invention is likely to exhibit light peelability (removability), which is preferable.

<Crosslinking agent>
In the surface protective film of the present invention, it is preferable that the pressure-sensitive adhesive composition contains a cross-linking agent. Further, in the present invention, the pressure-sensitive adhesive composition can be used to form a pressure-sensitive adhesive layer. For example, when the pressure-sensitive adhesive composition is an acrylic pressure-sensitive adhesive containing the (meth) acrylic polymer, the constituent units, the constituent ratios, the selection and addition ratio of the cross-linking agent, etc. of the (meth) acrylic polymer are appropriately selected. By adjusting and cross-linking, a pressure-sensitive adhesive layer (surface protective film) having higher heat resistance can be obtained.

As the cross-linking agent used in the present invention, an isocyanate compound, an epoxy compound, a melamine-based resin, an aziridine derivative, a metal chelate compound and the like may be used, and the use of an isocyanate compound and an epoxy compound is particularly preferable. Further, these compounds may be used alone or in combination of two or more.

Examples of the isocyanate compound include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), dimerate diisocyanate, cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate (IPDI), 1, Alicyclic isocyanates such as 3-bis (isocyanatomethyl) cyclohexane, aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate (XDI), and the isocyanate compounds. Examples thereof include polyisocyanate modified products modified by allophanate bond, biuret bond, isocyanate bond, uretdione bond, urea bond, carbodiimide bond, uretonimine bond, oxadiazine trione bond and the like. For example, as commercial products, trade names Takenate 300S, Takenate 500, Takenate 600, Takenate D165N, Takeda D178N (above, manufactured by Takeda Pharmaceutical Company Limited), Sumijuru T80, Sumijuru L, Death Module N3400 (above, Sumika Bayer Urethane). , Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (all manufactured by Nippon Polyurethane Industry Co., Ltd.) and the like. These isocyanate compounds may be used alone or in combination of two or more, or a bifunctional isocyanate compound and a trifunctional or higher isocyanate compound may be used in combination. By using a cross-linking agent in combination, it is possible to achieve both adhesiveness and resilience resistance (adhesiveness to a curved surface), and it is possible to obtain an adhesive layer (surface protective film) having higher adhesive reliability.

Examples of the epoxy compound include N, N, N', N'-tetraglycidyl-m-xylene diamine (trade name: TETRAD-X, manufactured by Mitsubishi Gas Chemical Company, Inc.) and 1,3-bis (N, N-diamine). Examples thereof include glycidylaminomethyl) cyclohexane (trade name: TETRAD-C, manufactured by Mitsubishi Gas Chemical Company, Inc.).

Examples of the melamine resin include hexamethylol melamine and the like. Examples of the aziridine derivative include commercial products such as HDU, TAZM, and TAZO (all manufactured by Mutual Pharmaceutical Co., Ltd.).

Examples of the metal chelate compound include aluminum, iron, tin, titanium, nickel and the like as metal components, and acetylene, methyl acetoacetate, ethyl lactate and the like as chelate components.

The content of the cross-linking agent used in the present invention is, for example, preferably 0.01 to 20 parts by weight, preferably 0.1 to 15 parts by weight, based on 100 parts by weight of the (meth) acrylic polymer. It is more preferably 0.5 to 10 parts by weight, and most preferably 1 to 8 parts by weight. If the content is less than 0.01 parts by weight, the cross-linking by the cross-linking agent may be insufficient, the cohesive force of the obtained pressure-sensitive adhesive layer may be small, and sufficient heat resistance may not be obtained. It tends to cause adhesive residue. On the other hand, when the content exceeds 20 parts by weight, the cohesive force of the polymer is large, the fluidity is lowered, and the wettability to the adherend (for example, a polarizing plate) is insufficient, so that the adherend and the pressure-sensitive adhesive are not sufficiently wetted. It tends to cause blisters that occur between the layer (adhesive composition layer). Further, these cross-linking agents may be used alone or in combination of two or more.

<Crosslink catalyst>
The pressure-sensitive adhesive composition may further contain a cross-linking catalyst for more effectively advancing any of the above-mentioned cross-linking reactions. Examples of such cross-linking catalysts include tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate, tris (acetylacetonato) iron, tris (hexane-2,4-dionat) iron, and tris (heptane-2,4-dionat). ) Iron, Tris (Heptane-3,5-Zionato) Iron, Tris (5-methylhexane-2,4-Zionato) Iron, Tris (Octane-2,4-Zionato) Iron, Tris (6-methylheptane-2) , 4-Zionato) Iron, Tris (2,6-dimethylheptane-3,5-Zionato) Iron, Tris (Nonan-2,4-Zionato) Iron, Tris (Nonan-4,6-Zionato) Iron, Tris ( 2,2,6,6-Tetramethylheptane-3,5-Zionato) Iron, Tris (Tridecane-6,8-Zionato) Iron, Tris (1-phenylbutane-1,3-Zionato) Iron, Tris (Hexa) Fluoroacetylacetonato) iron, tris (ethylacetate) iron, tris (acetoacetate-n-propyl) iron, tris (isopropylacetate isopropyl) iron, tris (acetoacetate-n-butyl) iron, tris (acetoacetate- sec-butyl) iron, tris (acetoacetic acid-tert-butyl) iron, tris (propionylmethylacetate) iron, tris (propionylethylacetate) iron, tris (propionylacetate-n-propyl) iron, tris (propionylacetate isopropyl) Iron, Tris (propionyl acetate-n-butyl) iron, Tris (propionyl acetate-sec-butyl) iron, Tris (propionyl acetate-tert-butyl) iron, Tris (benzyl acetoacetate) iron, Tris (dimethyl malonate) iron , Tris (diethyl malonate) iron, trimethoxy iron, triethoxy iron, triisopropoxy iron, ferric chloride and other iron-based catalysts can be used. These cross-linking catalysts may be used alone or in combination of two or more.

The content of the cross-linking catalyst is not particularly limited, but is preferably, for example, about 0.0001 to 1 part by weight, preferably 0.001 to 0.5 parts by weight, based on 100 parts by weight of the (meth) acrylic polymer. The weight part is more preferable. When it is within the above range, the rate of the crosslinking reaction is high when the pressure-sensitive adhesive layer is formed, and the pot life of the pressure-sensitive adhesive composition is long, which is a preferable embodiment.

Further, the pressure-sensitive adhesive composition may contain other known additives such as lubricants, colorants, powders such as pigments, plasticizers, pressure-sensitive adhesives, low-molecular-weight polymers, and surface lubrication. Agents, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, UV absorbers, polymerization inhibitors, silane coupling agents, antioxidants, inorganic or organic fillers, metal powders, particles, foils It can be added as appropriate depending on the intended use of the substance.

<Optical surface protection film with separator>
The optical surface protective film (surface protective film) with a separator of the present invention is formed by forming the pressure-sensitive adhesive layer on at least one side of the base film, and at that time, the cross-linking of the pressure-sensitive adhesive composition is adhesive. It is generally performed after the application of the agent composition, but it is also possible to transfer the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition after cross-linking to a base film or the like.

The method for forming the pressure-sensitive adhesive layer on the base film is not particularly limited. For example, the pressure-sensitive adhesive composition (solution) is applied to the base film, and a polymerization solvent or the like is dried and removed to form the pressure-sensitive adhesive layer. It is produced by forming it on a base film. After that, curing may be performed for the purpose of adjusting the component transfer of the pressure-sensitive adhesive layer, adjusting the cross-linking reaction, and the like. Further, when the pressure-sensitive adhesive composition is applied onto the base film to prepare a surface protective film, one or more kinds other than the polymerization solvent may be contained in the pressure-sensitive adhesive composition so that the pressure-sensitive adhesive composition can be uniformly applied on the base film. A new solvent may be added.

Further, as a method for forming the pressure-sensitive adhesive layer when manufacturing the surface protective film of the present invention, a known method used for manufacturing pressure-sensitive adhesive tapes is used. Specific examples thereof include a roll coat, a gravure coat, a reverse coat, a roll brush, a spray coat, an air knife coat method, and an extrusion coat method using a die coater or the like.

The surface protective film of the present invention is usually prepared so that the thickness of the pressure-sensitive adhesive layer is about 3 to 100 μm, preferably about 5 to 50 μm. When the thickness of the pressure-sensitive adhesive layer is within the above range, it is easy to obtain an appropriate balance between removability and adhesiveness, which is preferable.

The total thickness of the surface protective film of the present invention is preferably 8 to 300 μm, more preferably 10 to 200 μm, and most preferably 20 to 100 μm. Within the above range, the adhesive properties (removability, adhesiveness, etc.), workability, and appearance characteristics are excellent, which is a preferable embodiment. The total thickness means the total thickness including all layers such as the base film, the pressure-sensitive adhesive layer, the separator, and other layers.

<Separator>
The surface protective film of the present invention has a pressure-sensitive adhesive layer on at least one surface of the base film, and has a separator on the surface opposite to the surface of the pressure-sensitive adhesive layer in contact with the base film , and the separator is It has a release layer and a base material, and the separator has a haze of 90% or more and a total light transmittance of 50% or less. The separator is for attaching a separator to the surface of the pressure-sensitive adhesive layer for the purpose of protecting the pressure-sensitive surface of the pressure-sensitive adhesive layer, and in particular, the separator has optical properties such as specific haze and total light transmittance. The optical surface protective film with a separator can be accurately positioned on the optical member, and after the position adjustment, the optical surface protective film from which the separator has been peeled off can be attached (laminated) to the surface of the optical member, which is a preferable embodiment. ..

The haze of the separator is 90% or more, the total light transmittance is 50% or less (0 to 50%), preferably the haze is 92% or more, and the total light transmittance is 5 to 50%, more preferably haze. Is 94% or more, the total light transmittance is 8 to 48%, more preferably the haze is 96% or more, and the total light transmittance is 10 to 45%. Since the haze of the separator is 90% or more and the total light transmittance is 50% or less, the position adjustment property of the optical surface protective film with a separator with respect to the surface of the optical member is excellent, and the separator is peeled off after the position adjustment. This is a preferable embodiment because it can be bonded to the surface of the optical member at an accurate position. In particular, the total light transmittance is 50% or less (0 to 50%), preferably 48% or less, more preferably 45% or less, still more preferably 40% or less. Particularly preferably, it is 30% or less. Since the total light transmittance is low, it becomes easy to adjust the position with respect to the surface of the optical member of the optical surface protective film with a separator, and the position adjustability and workability are excellent, which is preferable.

<Base material>
Paper or a plastic film is preferably used as the base material. The film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer, and is, for example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, and a vinyl chloride co-weight. Examples thereof include coalesced film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, and in particular, polyethylene terephthalate (PET) film and polyethylene naphthalate which are polyester films. It is preferable to use a film, a polybutylene terephthalate film, or the like.

As a method for adjusting the haze of the separator to 90% or more and the total light transmittance to 50% or less, a known method can be used without particular limitation. For example, a cavity is provided in the base material constituting the separator. It can also be prepared by adding a coloring material, roughening the surface of the base material, or the like. Specifically, the method described in JP-A-9-12759 can be mentioned.

The thickness of the base material is usually about 5 to 200 μm, preferably about 10 to 100 μm. When it is within the above range, it is preferable because it is excellent in the workability of bonding to the pressure-sensitive adhesive layer and the peelability and workability of the separator with respect to the pressure-sensitive adhesive layer.

The surface of the base material may be subjected to various surface treatments such as corona discharge treatment and various surface treatments such as embossing, if necessary. In addition, if necessary, fillers (inorganic fillers, organic fillers, etc.), antioxidants, antioxidants, UV absorbers, antistatic agents, lubricants, plasticizers, colorants (pigments, dyes, etc.), etc. Various additives may be blended.

Examples of commercially available products of the base material include Diafoil W100, Diafoil W400 (all manufactured by Mitsubishi Plastics Co., Ltd.), Lumirror # 50-EA3S (manufactured by Toray Industries, Inc.), CQ952 (manufactured by KOLON Co., Ltd.) and the like.

<Release layer>
The release layer has adhesion to the base material and is removable from the pressure-sensitive adhesive layer, and can be formed from the release agent composition. The release agent composition is not particularly limited, and for example, a silicone compound such as dimethylsiloxane or diphenylsiloxane, a long-chain alkyl compound such as a silicone resin, a fluororesin, or asioresin can be used.

Further, the release agent composition may contain other known additives, such as antistatic agents, colorants, powders such as pigments, surfactants, plasticizers, and tackifiers. , Low molecular weight polymers, surface lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, UV absorbers, polymerization inhibitors, silane coupling agents, inorganic or organic fillers, metal powders, particulates, etc. Can be appropriately added depending on the intended use.

<Making a separator>
The separator is formed on the substrate by using the release agent composition.

The method for forming the release layer on the base material is not particularly limited, but for example, the solution of the release agent composition is applied to the base material, the polymerization solvent and the like are dried and removed, and the release layer is placed on the base material. It is produced by forming in. After that, curing may be performed for the purpose of adjusting the component transfer of the release layer. Further, when the release agent composition is applied onto a base material to prepare a release layer, one or more types other than the polymerization solvent may be contained in the release agent composition so that the release agent composition can be uniformly applied onto the base material. A new solvent may be added.

Further, as the method for forming the release layer, a known method used for producing the release layer is used. Specific examples thereof include a roll coat, a gravure coat, a reverse coat, a roll brush, a spray coat, an air knife coat method, and an extrusion coat method using a die coater or the like.

The thickness of the release layer is typically 1 to 200 nm, preferably 5 to 100 nm, and more preferably 10 to 50 nm. If the thickness of the release layer is too small, it becomes difficult to peel off the separator, which may make it difficult to attach the optical surface protective film. On the other hand, if it is too thick, it may affect the contaminating property of the pressure-sensitive adhesive layer of the optical surface protective film.

Examples of commercially available products of the separator include Crisper K7211-50 μm, Crisper K7211-38 μm, Crisper K7011-50 μm, Crisper K7011-38 μm (all manufactured by Toyobo Co., Ltd.) and the like.

<Lasting of optical surface protective film and separator (manufacturing of optical surface protective film with separator)>
The optical surface protective film with a separator of the present invention is in the form of laminating the pressure-sensitive adhesive layer of the optical surface protective film and the release layer of the separator. A known method is used for bonding, and examples thereof include a method of bonding an optical surface protective film and a separator using a laminator (MRK-600, manufactured by MCC Co., Ltd.).

<Optical member>
In the present invention, the optical surface protective film from which the separator is peeled off from the surface of the pressure-sensitive adhesive layer of the optical surface protective film with a separator can be attached to the optical member to protect the optical member. Since the separator has excellent cushioning properties, dents are less likely to occur, and the optical surface protective film has excellent appearance quality (appearance), so that it is used for surface protection (surface) during processing, transportation, shipping, etc. Since it can be used as a protective film), it is useful for protecting the surface of the optical member (polarizing plate or the like).

Hereinafter, some examples related to the present invention will be described, but the present invention is not intended to be limited to those shown in such specific examples. In addition, "part" and "%" in the following description are based on weight unless otherwise specified. In addition, the blending amount (addition amount) in the table is shown.

In addition, each characteristic in the following description was measured or evaluated as follows.

<Measurement of haze>
The haze was measured using a haze meter (HM-150 type manufactured by Murakami Color Technology Research Institute) according to the method specified in JIS K7136 "Plastic-How to obtain haze of transparent material".

<Measurement of total light transmittance>
The total light transmittance is measured using a haze meter (Murakami Color Technology Research Institute, HM-150 type) according to the method specified in JIS K7361 "Plastic-Test method for total light transmittance of transparent materials". rice field.

<Measurement of (meth) acrylic polymer glass transition temperature (Tg)>
The glass transition temperature (Tg) (° C.) was determined by the following formula using the following literature values as the glass transition temperature Tgn (° C.) of the homopolymer by each monomer.
Equation: 1 / (Tg + 273) = Σ [Wn / (Tgn + 273)]
(In the formula, Tg (° C.) is the glass transition temperature of the copolymer, Wn (-) is the weight fraction of each monomer, Tgn (° C.) is the glass transition temperature of the homopolymer by each monomer, and n is the type of each monomer. Represents.)
Reference value:
2-Ethylhexyl acrylate (2EHA): -70 ° C
Butyl acrylate (BA): -55 ° C
2-Hydroxyethyl acrylate (HEA): -15 ° C.
Acrylic acid (AA): 106 ° C
As the literature values, we referred to "Acrylic resin synthesis / design and new application development" (published by the Publishing Department of the Central Management Development Center).

<Measurement of weight average molecular weight (Mw) of (meth) acrylic polymer>
The weight average molecular weight (Mw) of the (meth) acrylic polymer used was measured using a GPC apparatus (HLC-8220 GPC) manufactured by Tosoh Corporation. The measurement conditions are as follows.
Sample concentration: 0.2% by weight (THF solution)
Sample injection volume: 10 μl
Eluent: THF
Flow velocity: 0.6 ml / min
Measurement temperature: 40 ° C
column:
Sample column; TSKguardcolum SuperHZ-H (1) + TSKgel SuperHZM-H (2)
Reference column; TSKgel SuperH-RC (1)
Detector: Differential Refractometer (RI)
The weight average molecular weight was determined by the polystyrene conversion value. Further, when measuring the number average molecular weight (Mn), it was measured in the same manner as the weight average molecular weight (Mw).

<Availability of automatic bonding>
Only the surface protective film was cut to 100 mm × 110 mm so as not to cut the separator of the optical surface protective film with a separator. Subsequently, a hole having a diameter of 5 mm was made in the separator so as to be in contact with each corner of the cut surface protective film.
An optical surface protective film with a separator made by the above method is used as a separator on one of the adsorption plates (hereinafter referred to as adsorption plate 1) of a precision sheet-fed bonding machine (SE650naa manufactured by Climb Products Co., Ltd.). The glass was installed so that the side was facing up, and 100 mm × 110 mm glass was installed on the other suction plate (hereinafter referred to as suction plate 2). The suction plate 1 was rotated and superposed on the suction plate 2, and the position of the suction plate 2 was adjusted so that the hole of the optical surface protective film with a separator and the glass did not overlap with the CCD camera attached to the precision sheet-fed bonding machine. After adjusting the position (see FIG. 2), the suction plate 1 is temporarily floated from the suction plate 2, the separator is peeled off, the suction plate 1 is moved onto the suction plate 2 again, and the optical surface protective film is rolled at a roll pressure of 8 kgf / cm ² . , Laminated on the glass surface at a roll speed of 5 mm / sec.
Whether or not automatic bonding is possible (evaluation) is ○ when the optical surface protection film can be automatically and accurately adjusted and bonded, and when the optical surface protection film cannot be automatically and accurately positioned. Was set to x.

<Preparation of (meth) acrylic polymer (A)>
100 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA), 2, as a polymerization initiator, in a four-flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. Add 0.2 parts by weight of 2'-azobisisobutyronitrile (AIBN) and 205 parts by weight of ethyl acetate, introduce nitrogen gas with gentle stirring, and keep the liquid temperature in the flask at around 63 ° C. The polymerization reaction was carried out for 4 hours to prepare a (meth) acrylic polymer (A) solution (about 35% by weight). The weight average molecular weight (Mw) of the (meth) acrylic polymer (A) was 650,000, and the glass transition temperature (Tg) was −68 ° C.

<Preparation of (meth) acrylic polymer (B)>
95 parts by weight of butyl acrylate (BA), 5 parts by weight of acrylic acid (AA), 2,2'-azo as a polymerization initiator in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. 0.1 part by weight of bisisobutyronitrile and 234 parts by weight of ethyl acetate were charged, nitrogen gas was introduced while gently stirring, and the liquid temperature in the flask was maintained at around 65 ° C. to carry out the polymerization reaction for 6 hours. A (meth) acrylic polymer (B) solution (30% by weight) was prepared. The weight average molecular weight (Mw) of the (meth) acrylic polymer (B) was 1.1 million, and the glass transition temperature (Tg) was −47 ° C.

[Acrylic adhesive (1) Preparation of solution]
The above (meth) acrylic polymer (A) solution (35% by weight) was diluted with ethyl acetate to 29% by weight, and 500 parts by weight (solid content 100 parts by weight) of this solution was added with a trifunctional isocyanate compound as a cross-linking agent. Isocyanurate of a certain hexamethylene diisocyanate (coronate HX: C / HX, manufactured by Nippon Polyurethane Co., Ltd.) 4 parts by weight (solid content 4 parts by weight), dibutyltin dilaurate as a cross-linking catalyst (“Sn” in Table 2, 1% by weight) (Ethyl acetate solution) 1.5 parts by weight (solid content 0.015 parts by weight) was added, and the mixture was mixed and stirred at around 25 ° C. for about 1 minute to prepare an acrylic pressure-sensitive adhesive (1) solution.

[Preparation of acrylic adhesive (2) solution]
The above (meth) acrylic polymer (A) solution (35% by weight) is diluted with ethyl acetate to 29% by weight, and an isocyanate-based cross-linking agent (isocyanate-based cross-linking agent) is added to 500 parts by weight (solid content 100 parts by weight) of this solution. Hexamethylene diisocyanate isocyanurate (trade name "Coronate HX": C / HX, manufactured by Nippon Polyurethane Co., Ltd.) 5 parts by weight (solid content 5 parts by weight), dibutyltin dilaurate (1 wt% ethyl acetate solution) 3 as a cross-linking catalyst 0.3 parts by weight (solid content 0.03 part by weight), polyoxyalkylene chain-containing compound (Aqualon HS-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) containing no organopolysiloxane as an additive, 0.3 part by weight (solid content 0) .3 parts) was added, and the mixture was mixed and stirred to prepare an acrylic pressure-sensitive adhesive (2) solution.

[Preparation of acrylic adhesive (3) solution]
The above (meth) acrylic polymer (B) solution (30% by weight) was diluted with ethyl acetate to 29% by weight, and an epoxy-based cross-linking agent (an epoxy-based cross-linking agent) was added to 500 parts by weight (solid content 100 parts by weight) of this solution. 1,3-Bis (N, N-dilutionidylaminomethyl) cyclohexane, epoxy equivalent: 110, number of functional groups: 4, trade name "TETRAD-C": T / C, manufactured by Mitsubishi Gas Chemicals, Inc.) 6 parts by weight (solid) 6 parts by weight) was added, and the mixture was mixed and stirred to prepare a solution of the acrylic pressure-sensitive adhesive (3).

[Preparation of urethane adhesive (4) solution]
As a polyol, Preminol S3011 (Mn = 10000, manufactured by Asahi Glass Co., Ltd.), which is a polyol having three hydroxyl groups, 85 parts by weight, and Sanniks GP3000 (Mn = 3000, manufactured by Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups, 13 By weight, 2 parts by weight of Sanniks GP1000 (Mn = 1000, manufactured by Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups, and as a cross-linking agent, an isocyanurate form of hexamethylene diisocyanate, which is a trifunctional isocyanate compound (Coronate HX:). C / HX, manufactured by Nippon Polyurethane Co., Ltd.) 18 parts by weight, as a catalyst, iron (III) acetylacetonate (tris (acetylacetonato) iron, "Fe" in Table 3, manufactured by Tokyo Kasei Kogyo Co., Ltd.) 0.04 weight 30 parts by weight of isopropyl myrstate (EXPEAL IPM, manufactured by Kao) as a wettability improver, 0.5 part by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, and 210 parts by weight of ethyl acetate as a diluting solvent. , Urethane-based pressure-sensitive adhesive (4) solution was obtained.

[Preparation of Silicone Adhesive (5) Solution]
As a silicone-based adhesive, "X-40-3229" (solid content 60% by weight, manufactured by Shin-Etsu Chemical Co., Ltd.) is 100 parts by weight in solid content, and as a platinum catalyst, "CAT-PL-50T" (Shin-Etsu Chemical Co., Ltd.) (Manufactured by) 0.5 parts by weight and 100 parts by weight of toluene as a solvent were blended to obtain a silicone-based pressure-sensitive adhesive (5) solution.

[Separators I, II and VII]
As shown in Table 5, a commercially available product using a base material with a release layer provided on the base material (PET film) as a separator was used.

[Preparation of Separator III]
Add 100 parts by weight of silicone release agent (KS-847H, manufactured by Shinetsu Chemical Industry Co., Ltd.), 3.3 parts by weight of silicone curing catalyst (CAT-PL-50T, manufactured by Shinetsu Chemical Industry Co., Ltd.), and toluene (manufactured by Idemitsu Petrochemical Co., Ltd.). Hexane (manufactured by Maruzen Petrochemical, normal hexane) and methyl ethyl ketone (manufactured by Idemitsu Kosan, MEK) were diluted to 0.3% by weight with a solvent having a weight ratio of 1: 2: 1 to obtain a release agent composition. This mold release agent composition was applied to a PET film (manufactured by Mitsubishi Plastics, Diafoil W100) as a base material having a thickness of 50 μm, and dried at 130 ° C. for 1 minute to prepare a separator III. The thickness of the release layer after drying was 20 nm.

[Preparation of Separator IV-VI and VIII]
As shown in Table 5, the PET film having the trade name shown in Table 5 was used instead of the PET film used in Separator III, but the same method as in the preparation of Separator III was used.

<Example 1>
[Preparation of antistatic film]
Antistatic agent (manufactured by Solvex, Microsolver RMd-142, mainly composed of tin oxide and polyester resin) 10 parts by weight is diluted with a mixed solvent consisting of 30 parts by weight of water and 70 parts by weight of methanol to prevent antistatic. An agent solution was prepared.
The obtained antistatic agent solution was applied onto a polyethylene terephthalate (PET) film (thickness: 38 μm) as a base film using a Meyer bar, and dried at 130 ° C. for 1 minute to remove the solvent. An antistatic layer (thickness: 0.2 μm) was formed to prepare an antistatic treated film.

[Manufacturing of optical surface protective film with separator]
The acrylic pressure-sensitive adhesive (1) solution was applied to the surface of the antistatic treatment film opposite to the antistatic treatment surface, and heated at 130 ° C. for 2 minutes to form a pressure-sensitive adhesive layer having a thickness of 15 μm. .. Next, a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., trade name: Crisper K7211-38 μm, haze: 99.3%, total light transmittance: 13.), which is a separator having a silicone treatment on one side of the surface of the pressure-sensitive adhesive layer. A silicon-treated surface of 6% (thickness 50 μm) was bonded to prepare an optical surface protective film with a separator.

<Examples 2 and 3>
As shown in Table 2, it was carried out except that the acrylic pressure-sensitive adhesive (2) solution or the acrylic pressure-sensitive adhesive (3) solution was used instead of the acrylic pressure-sensitive adhesive (1) solution used in Example 1. An optical surface protective film with a separator was produced in the same manner as in Example 1.

<Examples 4 and 5>
As shown in Tables 3 and 4, instead of the acrylic pressure-sensitive adhesive (1) solution used in Example 1, a urethane-based pressure-sensitive adhesive (4) solution or a silicone-based pressure-sensitive adhesive (5) solution was used. Except for this, an optical surface protective film with a separator was produced by the same method as in Example 1 in which the heating conditions and the like and the thickness of the obtained adhesive layer were adjusted.

<Examples 6 to 10, Comparative Examples 1 and 2>
As shown in Table 6, an optical surface protective film with a separator was produced in the same manner as in Example 1 except that separators II to VIII were used instead of the separator I used in Example 1.

Tables 1 to 6 show the above-mentioned compounding contents, various measurements and evaluation results of the optical surface protective film with a separator according to Examples and Comparative Examples. The blending amount in the table indicates the active ingredient.

注）表５中のセパレータを構成する基材は全てＰＥＴフィルムである。

Note) The base materials constituting the separator in Table 5 are all PET films.

From Table 6 above, it was confirmed that automatic bonding can be performed at the correct position in all the examples. In Comparative Example 1 and Comparative Example 2, since the haze of the separator and the total light transmittance were out of the desired range, the position of the optical surface protective film with a separator could not be automatically adjusted with respect to the surface of the optical member, and after the separator was peeled off. It was confirmed that the optical surface protective film could not be attached to the surface of the optical member at an accurate position.

The optical surface protective film with a separator disclosed herein is used during manufacturing, transportation, etc. of an optical member used as a component of a liquid crystal display panel, a plasma display panel (PDP), an organic electroluminescence (EL) display, or the like. It is suitable as a surface protective film for protecting an optical member. In particular, it is useful as an optical surface protective film applied to optical members such as polarizing plates (polarizing films) for liquid crystal display panels, wave plates, retardation plates, optical compensation films, brightness improving films, light diffusion sheets, and reflective sheets. Is.

1: Separator 2: Optical surface protective film 3: Optical surface protective film with separator 10: Optical member 11: Base material 12: Release layer 21: Adhesive layer 22: Base material film

Claims (3)

An optical surface protective film having an adhesive layer on at least one side of the base film, and an optical surface protective film with a separator having a separator on the surface opposite to the surface of the pressure-sensitive adhesive layer in contact with the base film. ,
The separator has a release layer and a substrate and has
The base material is a polyester-based film.
An optical surface protective film with a separator, characterized in that the haze of the separator is 90% or more and the total light transmittance is 50% or less.
The optical surface protective film with a separator according to claim 1, wherein the base film is a polyester film. Claim 1 or 2 characterized in that the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition containing at least one selected from an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive. Optical surface protective film with separator as described in.

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