TWI772517B - Adhesive composition, adhesive sheet and optical member - Google Patents

Abstract

The present invention provides an adhesive composition, an adhesive sheet formed from the above-mentioned adhesive composition, and an optical member to which the above-mentioned adhesive sheet is adhered. , peeling and curl control, adhesion, light peeling (repeelability) and stain resistance (low stain) excellent. The adhesive composition of the present invention is characterized by containing an adhesive polymer and a fluorine-containing oligomer having a hydroxyl value of 1 or more.

Description

Adhesive composition, adhesive sheet and optical member

Field of Invention The present invention relates to an adhesive composition, an adhesive sheet and an optical member. In particular, the adhesive sheet obtained from the above-mentioned adhesive composition is suitable for applications such as being attached to plastic products that are prone to static electricity (for example, liquid crystal display panels, plasma display panels (PDP), organic electroluminescence (EL) displays, etc. ), which are especially used for the purpose of protecting the surface of optical components (such as polarizers, wave plates, retardation plates, optical compensation films, reflective sheets, brightness enhancement films used in liquid crystal displays, etc.), etc. Surface protection film.

Background of the Invention A surface protective film (also referred to as a surface protective sheet) generally has a structure in which an adhesive layer is provided on a film-like base film (support). The purpose of use of the protective film is to adhere to an adherend (protected body) through the above-mentioned adhesive layer, thereby protecting the adherend from damage or stains during processing and transportation. For example, the panel of a liquid crystal display is formed by bonding optical members, such as a polarizing plate and a wave plate, to a liquid crystal cell via an adhesive bond layer. In the manufacture of the liquid crystal display panel, the polarizing plate to be attached to the liquid crystal cell is first manufactured into a roll shape, then unrolled from the roll, and cut into a desired size corresponding to the shape of the liquid crystal cell for use . Here, in order to prevent the polarizing plate from being damaged by friction with a conveying roller or the like in an intermediate process, a countermeasure is taken to attach a surface protection film to one side or both sides (typically, one side) of the polarizing plate. The surface protection film will be peeled off at a stage where the surface protection film is no longer needed.

The surface protective film is required to have curl adjustment properties so that when it is adhered to the adherend (polarizing plate, etc.), unnecessary curling or unexpected curling does not occur in the adherend (polarizing plate, etc.) to which the surface protective film is adhered. Curling (curling refers to a phenomenon of warping, for example, a phenomenon in which a flat object is warped as a whole on either surface side, or a phenomenon in which the entire flat object is warped in an undulating manner). When unnecessary curling or unexpected curling occurs, workability is poor. For example, when an adherend such as a polarizing plate is adhered to a liquid crystal cell, problems such as entrainment of air bubbles occur.

When curling occurs in a flat adherend, in the adhesive layer of the surface protection film attached to the adherend, the force accompanying the curling acts in the shearing direction, and this force causes Since slippage (displacement) and the like gradually occur between the adherend and the adhesive layer, it is required to increase the shear force at the time of low-speed peeling.

In addition, in order to prevent the surface protective film from lifting, peeling, etc. during processing and transportation of the adherend (object to be protected), it is required to have an appropriate adhesive force and light peelability (repeelability) when peeling at a low speed. .

Therefore, in order to realize light peeling, various methods are implemented for the adhesive composition used for the surface protection film. For example, the following examples are reported: the polymer used in the adhesive composition contains a component with a high glass transition temperature (Tg), a reactive surfactant, etc.; and the adhesive composition is highly cross-linked. etc. (for example, see Patent Document 1).

However, in the above-mentioned method, even if the light peeling can be achieved, since additives such as surfactants are contained, the additives will ooze out at the interface between the adhesive layer and the adherend, causing contamination, which is easy to produce. Sliding (offset) worries. prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2002-221906

Summary of Invention The problem to be solved by the invention Therefore, in the present invention, as a result of intensive studies in view of the above-mentioned circumstances, an object of the present invention is to provide an adhesive composition which is less prone to sliding (shifting), lifting, and peeling of optical members such as polarizing plates. An adhesive layer and an adhesive sheet having excellent curl control properties, tackiness, light peelability (repeelability) during low-speed peeling, and stain resistance (low stainability), the present invention also provides an adhesive composed of the aforementioned adhesive composition. A sheet and an optical member to which the above-mentioned adhesive sheet is pasted.

means of solving problems That is, the adhesive composition of the present invention is characterized by containing an adhesive polymer and a fluorine-containing oligomer having a hydroxyl value of 1 or more.

In the adhesive composition of the present invention, preferably, the adhesive polymer is at least one selected from the group consisting of (meth)acrylic polymers, urethane polymers and polysiloxane polymers A sort of.

The adhesive sheet of the present invention preferably has an adhesive layer formed of the adhesive composition on at least one side of the base film, and the fluorine-containing oligomer is present in and/or on the surface of the adhesive layer.

In the pressure-sensitive adhesive sheet of the present invention, it is preferable that a separator is stuck on the surface opposite to the surface of the pressure-sensitive adhesive layer that is in contact with the base film.

In the pressure-sensitive adhesive sheet of the present invention, it is preferable that the fluorine-containing oligomer is present on the surface of the separator in contact with the pressure-sensitive adhesive layer.

It is preferable that the optical member of this invention is stuck with the said adhesive sheet or the adhesive sheet which peeled the said separator from the said adhesive sheet.

Invention effect In the present invention, by using an adhesive composition containing a specific fluorine-containing oligomer, after bonding an adhesive sheet having an adhesive layer formed of the adhesive composition to an optical member such as a polarizing plate, slippage (displacement) can be suppressed. ), lifting, and peeling, so the curl controllability is excellent, and the appropriate adhesive force (adhesion) until peeling can be maintained, and light peeling (repeelability) during low-speed peeling can be achieved. (Low contamination property) is also excellent, and thus is useful.

Form for carrying out the invention Hereinafter, embodiments of the present invention will be described in detail.

<Overall structure of adhesive sheet (surface protection film)> The adhesive sheet disclosed here is generally called an adhesive tape, an adhesive label, an adhesive film, or the like, and is particularly suitable as an optical component used as an optical component (for example, an optical component used as a component of a liquid crystal display panel such as a polarizer and a wave plate) ) surface protection film to protect the surface of optical parts during processing and transportation. The adhesive layer in the surface protective film is typically formed continuously, but is not limited to this form, and may be, for example, an adhesive layer formed in a regular or irregular pattern such as dots and stripes. In addition, the surface protection film disclosed here may be in the form of a roll, or may be in the form of a single sheet.

<Substrate film> The adhesive sheet (surface protection film) 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, properties such as transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, flexibility, and dimensional stability are preferably used. Excellent resin material. In particular, since the base film has flexibility, the adhesive composition can be applied by a roll coater or the like, and it can be wound into a roll shape, which is useful.

As the base film (base material, support), for example, a plastic film composed of a resin material having the following as the main resin component (main component of the resin component, typical In terms of components accounting for more than 50% by mass): polyester-based polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate; Cellulose polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate polymers; acrylic polymers such as polymethyl methacrylate. As other examples of the aforementioned resin materials, the following can be cited as examples of the resin materials: styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymer; polyethylene, polypropylene, cyclic or Olefin polymers such as polyolefins with norbornene structure and ethylene-propylene copolymers; vinyl chloride polymers; amide polymers such as nylon 6, nylon 6,6, and aromatic polyamides. Other examples of the aforementioned resin materials include amide-imide-based polymers, silo-based polymers, polyether s-series polymers, polyether ether ketone-based polymers, polyphenylene sulfide-based polymers, and vinyl alcohol-based polymers. Polymers, vinylidene chloride polymers, vinyl butyral polymers, aryl ester polymers, polyoxymethylene polymers, epoxy polymers, etc. A base film composed of a blend of two or more of the above-mentioned polymers may also be used.

As the aforementioned base film, a plastic film made of a transparent thermoplastic resin material can be preferably used. Among the aforementioned plastic films, it is more preferable to use a polyester film. Here, polyester film refers to a polymer having a main skeleton based on an ester bond, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, or the like. material (polyester resin) as the main resin component of the film. The polyester film has optical properties and excellent dimensional stability, which are desirable properties as a base film for an adhesive sheet (surface protective film). On the other hand, it has the property of being easily charged.

Various additives such as antioxidants, ultraviolet absorbers, plasticizers, colorants (pigments, dyes, etc.) can be blended into the resin material constituting the aforementioned base film as necessary. For example, known or conventional surface treatments such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, and application of a primer can also be carried out. Such surface treatment may be, for example, treatment for improving the adhesion between the base film and the adhesive layer (anchoring property of the adhesive layer).

The adhesive sheet (surface protection film) of the present invention can also use an antistatically treated plastic film as the aforementioned base film. By using the above-mentioned base film, it is possible to suppress the charging of the adhesive sheet itself at the time of peeling, which is preferable. In addition, the base film is a plastic film, and by applying antistatic treatment to the aforementioned plastic film, a base film with excellent ability to reduce the charge of the adhesive sheet itself and prevent the electrostatic charge of the adherend can be obtained. It should be noted that the method for imparting an antistatic function is not particularly limited, and conventionally known methods can be used. A method of forming a conductive resin of a material, a conductive material; a method of vapor deposition or plating of a conductive material; a method of kneading an antistatic agent, etc., and the like.

The thickness of the said base film is about 5 micrometers - 200 micrometers normally, Preferably it is about 10 micrometers - 100 micrometers. When the thickness of the said base film is in the said range, since the workability|operativity of sticking to an adherend and the peeling workability of peeling from an adherend are excellent, it is preferable.

The pressure-sensitive adhesive sheet disclosed herein can also be implemented by including other layers in addition to the base film and the pressure-sensitive adhesive layer. As said other layer, the primer layer (anchor layer) etc. which improve the anchoring property of an antistatic layer and an adhesive layer are mentioned.

<Adhesive composition> The adhesive composition of the present invention can be used without particular limitation as long as it is an adhesive composition containing an adhesive adhesive polymer, and an adhesive layer can be formed from the above-mentioned adhesive composition. As the above-mentioned adhesive composition, for example, acrylic adhesives, urethane-based adhesives, synthetic rubber-based adhesives, natural rubber-based adhesives, polysiloxane-based adhesives, etc. can be used, among which, the above-mentioned adhesives are more preferable. The adhesive polymer is at least one selected from the group consisting of (meth)acrylic polymers, urethane polymers and polysiloxane polymers, and it is more preferable to use (containing) selected from Consists of acrylic adhesive containing (meth)acrylic polymer, urethane adhesive containing urethane polymer, and polysiloxane adhesive containing polysiloxane At least one of the group, it is particularly preferable to use an acrylic adhesive, and the acrylic adhesive uses a (meth)acrylic polymer which is the aforementioned adhesive polymer.

In the case where an acrylic adhesive is used for the above-mentioned adhesive layer, the (meth)acrylic polymer which is an adhesive polymer constituting the above-mentioned acrylic adhesive may be a raw material monomer having a carbon number of 1. A (meth)acrylic monomer having an alkyl group of to 14 is used as the main monomer. As the aforementioned (meth)acrylic monomers, one or two or more kinds can be used. By using the aforementioned (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, the peeling force (adhesive force) to the adherend (to-be-protected body) can be easily controlled to be low, and light peeling can be obtained. Adhesive sheet (surface protective film) with excellent releasability and releasability. In addition, (meth)acrylic-type polymer in this invention means acrylic-type polymer and/or methacrylic-type polymer, and (meth)acrylate means acrylate and/or methyl group Acrylate.

Specific examples of the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, and (meth)acrylic acid, for example. n-Butyl, tertiary butyl (meth)acrylate, tertiary butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethyl (meth)acrylate Hexyl ester, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, (meth)acrylate base) isodecyl acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, and the like.

Among them, when the adhesive sheet of the present invention is used as a surface protective film, n-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylate Base) n-octyl acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate (methyl) esters, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, etc. (methyl) having an alkyl group having 4 to 14 carbon atoms base) acrylic monomers as suitable starting monomers. In particular, by using a (meth)acrylic monomer having an alkyl group having 4 to 14 carbon atoms, it is easy to control the peeling force (adhesive force) to a to-be-adhered body low, and it becomes an adhesive sheet excellent in releasability .

In particular, it is preferable to contain 50 mass % or more of (meth)acrylic monomers having an alkyl group having 1 to 14 carbon atoms with respect to 100 mass % of the total amount of monomer components constituting the (meth)acrylic polymer. , more preferably 80% by mass or more, still more preferably 85% by mass to 99.9% by mass, and most preferably 90% by mass to 99% by mass. When it is less than 50 mass %, the appropriate wettability of the adhesive composition and the cohesive force of the adhesive layer are deteriorated, which is not preferable.

Moreover, in the adhesive composition of this invention, it is preferable that the said (meth)acrylic-type polymer contains a hydroxyl group-containing (meth)acrylic-type monomer as a raw material monomer. The aforementioned hydroxyl group-containing (meth)acrylic monomers may be used alone or in two or more. By using the above-mentioned hydroxyl group-containing (meth)acrylic monomer, it becomes easy to control the crosslinking of the adhesive composition, etc., and further, it becomes easy to control the improvement of the wettability due to the flow and the reduction of the peeling force (adhesive force) at the time of peeling. balance.

As said hydroxyl group-containing (meth)acrylic monomer, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate can be mentioned. ester, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxydecyl (meth)acrylate) Methylol cyclohexyl) methyl ester, N-methylol (meth) acrylamide, etc. In particular, by using a hydroxyl group-containing (meth)acrylic monomer having an alkyl group of 4 or more carbon atoms, light peeling at the time of high-speed peeling becomes easy, which is preferable.

The hydroxyl group-containing (meth)acrylic monomer is preferably contained in an amount of 25% by mass or less, more preferably 20% by mass or less, based on 100% by mass of the total amount of monomer components constituting the (meth)acrylic polymer. It is preferably 0.1% by mass to 15% by mass, and most preferably 1% by mass to 10% by mass. When it exists in the said range, since it becomes easy to control the balance of the wettability of an adhesive composition and the cohesion force of the adhesive layer obtained, it is preferable.

In addition, as other polymerizable monomer components, from the viewpoint of easily achieving a balance of adhesive properties, those for adjusting the glass transition temperature and peeling of the (meth)acrylic polymer can be used within a range that does not impair the effects of the present invention. A specific polymerizable monomer, etc., is used so that the Tg is 0°C or lower (usually -100°C or higher).

Polymers other than the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms and the hydroxyl group-containing (meth)acrylic monomer used in the (meth)acrylic polymer As a functional monomer, a carboxyl group-containing (meth)acrylic monomer can be used. By using the above-mentioned carboxyl group-containing (meth)acrylic monomer, the time-dependent increase in the adhesive force of the adhesive sheet (adhesive layer) can be suppressed, and the re-peelability, the increase in the anti-adhesion force, and the workability are excellent. Both of the cohesion force and the shear force of the layer are excellent, so it is preferable.

As said carboxyl group-containing (meth)acrylic monomer, (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, etc. are mentioned, for example.

With respect to 100 mass % of the total amount of monomer components constituting the (meth)acrylic polymer, the carboxyl group-containing (meth)acrylic monomer is preferably 0 to 5 mass %, more preferably 0 mass % to 3 mass %, more preferably 0 to 2 mass %, and most preferably 0.001 to 1 mass %. When it exists in the said range, since it becomes easy to control the balance of the wettability of an adhesive composition and the cohesion force of the adhesive layer obtained, it is preferable.

In addition, when using the said hydroxyl group-containing (meth)acrylic monomer and carboxyl group-containing (meth)acrylic monomer in combination, the total amount of the monomer components constituting the (meth)acrylic polymer is 100 mass %, it is preferable to contain 0.005 mass % - 0.1 mass % of the said carboxyl group-containing (meth)acrylic monomer. By adjusting to the said range, the adhesive bond layer (adhesive sheet) which is more excellent in re-peelability and anti-adhesive force increase property can be obtained, which is effective.

In addition, as the (meth)acrylic monomer, the hydroxyl group-containing (meth)acrylic monomer, and the carboxyl group-containing (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms used in the (meth)acrylic polymer Other polymerizable monomers other than the (meth)acrylic monomer can be used without particular limitations as long as they do not impair the characteristics of the present invention. For example, components that improve cohesion and heat resistance, such as cyano group-containing monomers, vinyl ester monomers, aromatic vinyl monomers, etc.; Monomers, epoxy group-containing monomers, N-acryloylmorpholine, vinyl ether monomers, etc. improve peeling force (adhesion) and have functional groups that function as crosslinking bases. Among them, nitrogen-containing monomers such as cyano group-containing monomers, amide group-containing monomers, amide imine group-containing monomers, amine group-containing monomers, and N-acryloylmorpholine are preferably used. The use of a nitrogen-containing monomer is useful because it is possible to secure an appropriate peeling force (adhesive force) that does not cause lifting, peeling, or the like, and to obtain an adhesive sheet (surface protective film) with more excellent shear force. One or two or more of these polymerizable monomers can be used.

As said cyano group containing monomer, acrylonitrile and methacrylonitrile are mentioned, for example.

Examples of the above-mentioned amide group-containing monomers include acrylamide, methacrylamide, diethylacrylamide, N-vinylpyrrolidone, and N,N-dimethylacrylamide. , N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N,N'-methylenebisacrylamide , N,N-dimethylaminopropyl acrylamide, N,N-dimethylaminopropyl methyl acrylamide, diacetone acrylamide, etc.

Examples of the aforementioned imidimide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, itaconicimide, and the like.

Examples of the above-mentioned amino group-containing monomer include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N- (meth)acrylate Dimethylaminopropyl ester, etc.

As said vinyl ester monomer, vinyl acetate, vinyl propionate, vinyl laurate, etc. are mentioned, for example.

As said aromatic vinyl monomer, styrene, chlorostyrene, chloromethylstyrene, (alpha)-methylstyrene, other substituted styrene etc. are mentioned, for example.

As said epoxy group-containing monomer, glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, allyl glycidyl ether, etc. are mentioned, for example.

As said vinyl ether monomer, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, etc. are mentioned, for example.

In the present invention, with respect to 100% by mass of the total amount of the monomer components constituting the (meth)acrylic polymer, the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, a hydroxyl group-containing ( It is preferable that it is 0 mass % - 50 mass %, and, as for other polymerizable monomers other than a meth)acrylic monomer and a carboxyl group-containing (meth)acrylic monomer, it is more preferable that it is 0 mass % - 20 mass %. In order to obtain desired properties, the aforementioned other polymerizable monomers can be appropriately adjusted.

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

In addition, the average number of moles of oxyalkylene units added to the alkylene oxide group-containing reactive monomer is preferably 1 to 40, more preferably 3 to 40, still more preferably 4 to 35, and particularly preferably 5 to 30. When the said average added mole number is 1 or more, there exists a tendency for the effect of reducing the contamination of a to-be-adhered body (to-be-protected body) to be obtained efficiently. Moreover, when the said average added mole number exceeds 40, since the viscosity of an adhesive composition becomes high and it tends to become difficult to coat, it is unpreferable. It should be noted that the terminal of the oxyalkylene chain may be a hydroxyl group itself, or may be substituted with other functional groups or the like.

The above-mentioned reactive monomer containing an alkylene oxide group may be used alone or in combination of two or more, and the total content is preferably 0% by mass in the total amount of the monomer components of the (meth)acrylic polymer. to 20% by mass, more preferably 0 to 10% by mass. When the content of the alkylene oxide group-containing reactive monomer is more than 20 mass %, the low contamination property to the adherend is deteriorated, which is not preferable.

As the oxyalkylene unit of the above-mentioned alkylene oxide group-containing reactive monomer, an oxyalkylene unit having an alkylene group having 1 to 6 carbon atoms can be mentioned, for example, an oxymethylene group can be mentioned. , oxyethylene, oxypropyl, oxybutyl, etc. The hydrocarbon group of the oxyalkylene chain may be straight or branched.

In addition, it is more preferable that the aforementioned alkylene oxide group-containing reactive monomer is a reactive monomer having an ethoxide group. By using a (meth)acrylic polymer containing a reactive monomer having an ethoxide group as a base polymer, the compatibility between the base polymer and the fluorine-containing oligomer is improved, and it is possible to appropriately suppress the It is possible to obtain an adhesive composition with stain resistance (low stain property) due to bleed-out to the adherend.

Examples of the above-mentioned reactive monomer containing an alkylene oxide group include: (meth)acrylic acid alkylene oxide adduct; a molecule having an acryl group, a methacryloyl group, an alkene Reactive surfactants of reactive substituents such as propyl group, etc.

Specific examples of the above-mentioned (meth)acrylic acid alkylene oxide adduct include, for example, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, polyethylene glycol- Polypropylene glycol (meth)acrylate, polyethylene glycol-polybutylene glycol (meth)acrylate, polypropylene glycol-polybutylene glycol (meth)acrylate, methoxy polyethylene glycol (meth) Acrylates, Ethoxy polyethylene glycol (meth)acrylate, Butoxy polyethylene glycol (meth)acrylate, Octyloxy polyethylene glycol (meth)acrylate, Lauryloxy polyethylene Glycol (meth)acrylate, stearyloxy polyethylene glycol (meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, Octyloxy polyethylene glycol-polypropylene glycol (meth)acrylate, etc.

Moreover, as a specific example of the said reactive surfactant, the anionic reactive surfactant which has a (meth)acryloyl group or an allyl group, a nonionic reactive surfactant, a cationic surfactant, for example is mentioned. type reactive surfactants, etc.

The weight average molecular weight (Mw) of the (meth)acrylic polymer is preferably 100,000 to 5,000,000, more preferably 200,000 to 4,000,000, still more preferably 300,000 to 3,000,000, and most preferably 300,000 to 950,000 . When the weight-average molecular weight is less than 100,000, the cohesive force of the adhesive layer tends to be small, and there is a tendency for glue residue to occur. On the other hand, when the weight average molecular weight exceeds 5 million, the fluidity of the polymer decreases, the wetting of the adherend (such as a polarizing plate) is insufficient, and the adherend and the adhesive sheet (surface protective film) become insufficient. ) tend to be the cause of the bulge that occurs between the adhesive layers. In addition, the weight average molecular weight means the weight average molecular weight measured by GPC (gel permeation chromatography).

In addition, the glass transition temperature (Tg) of the (meth)acrylic polymer is preferably 0°C or lower, and more preferably -10°C or lower (usually -100°C or higher). When the glass transition temperature is higher than 0°C, the polymer is not easy to flow, for example, the wetting of the polarizing plate as an optical member is insufficient, and the polarizing plate and the adhesive layer of the adhesive sheet (surface protection film) are formed between the polarizing plate and the adhesive layer (surface protection film). Tendency to cause bulge between. In particular, by adjusting the glass transition temperature to -61° C. or lower, an adhesive layer excellent in wettability to a polarizing plate and light peelability can be easily obtained. In addition, the glass transition temperature of a (meth)acrylic-type polymer can be adjusted to the said range by suitably changing the monomer component and composition ratio used.

The polymerization method of the aforementioned (meth)acrylic polymer is not particularly limited, and the polymerization can be carried out by known methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. From the viewpoint of properties such as low contamination properties of the protector), solution polymerization is a more preferable method. In addition, the obtained polymer may be any of random copolymers, block copolymers, alternating copolymers, graft copolymers, and the like.

When using a urethane-based adhesive for the aforementioned adhesive layer, any appropriate urethane-based adhesive can be used. As such a urethane type adhesive, the urethane type adhesive which consists of a urethane type polymer which is an adhesive polymer obtained by making a polyol and a polyisocyanate compound react is mentioned preferably. As a polyol, a polyether polyol, a polyester polyol, a polycarbonate polyol, a polycaprolactone polyol, etc. are mentioned, for example. As a polyisocyanate compound, diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, etc. are mentioned, for example.

When a polysiloxane-based adhesive is used in the aforementioned adhesive layer, any suitable polysiloxane-based adhesive can be used. As such a polysiloxane-based adhesive, a polysiloxane-based adhesive obtained by blending or agglomerating a polysiloxane-based polymer, which is an adhesive polymer, can be preferably used.

In addition, as the aforementioned polysiloxane-based adhesive, an addition reaction-curable polysiloxane-based adhesive and a peroxide-curable polysiloxane-based adhesive can be exemplified. Among these polysiloxane-based adhesives, addition-reaction-curable polysiloxane-based adhesives are preferred because no peroxide (benzyl peroxide, etc.) is used and no decomposition products are produced.

As the curing reaction of the aforementioned addition reaction-curable polysiloxane-based adhesive, for example, in the case of obtaining a polyalkyl polysiloxane-based adhesive, in general, the use of a platinum catalyst to make polyalkylhydrogensiloxane A method of curing an alkane composition.

<Fluorine-containing oligomer> The adhesive composition of the present invention is characterized in that it contains an adhesive polymer and a fluorine-containing oligomer having a hydroxyl value of 1 or more. By including a fluorine-containing oligomer having a hydroxyl value of 1 or more in the above-mentioned adhesive composition, when the obtained adhesive layer (adhesive sheet) is bonded to an optical member such as a polarizing plate, it is possible to exert the advantages of containing The light peeling effect due to the low surface free energy of the fluorine moiety in the fluorine-type oligomer, in addition, when the hydroxyl value is 1 or more, the interaction between the fluorine-type oligomer and the adhesive polymer is strengthened, and the adhesion to the adherend is enhanced. The transfer amount of the adhesive sheet (surface protection film) is reduced, and the slip (offset), lift-up, peeling, etc. of the adhesive sheet (surface protection film) can be suppressed, in other words, light peelability (repeelability) and adhesiveness can be achieved, which is a preferable form. Further, the adhesive sheet of the present invention preferably has an adhesive layer formed of the adhesive composition on at least one side of the base film, and the fluorine-containing oligomer is present in and/or on the surface of the adhesive layer. It should be noted that the “inside” of the pressure-sensitive adhesive layer, for example, when the pressure-sensitive adhesive layer is formed using the pressure-sensitive adhesive composition blended with the fluorine-containing oligomer, refers to being included in the pressure-sensitive adhesive layer. Case. In addition, the "surface" of the adhesive layer, for example, when the fluorine-containing oligomer contained in the adhesive layer in which the fluorine-containing oligomer is blended is present (exposed) on the surface of the adhesive layer, Or when the surface of the separator pasted to protect the surface of the adhesive layer is pre-coated (laminated) with the fluorine-containing oligomer and the separator is pasted on the adhesive layer, the fluorine-containing oligomer refers to the In the case where the substance is transferred (transferred) from the surface of the separation member to the surface of the adhesive layer.

The hydroxyl value of the fluorine-containing oligomer is 1 or more, preferably 5 or more, more preferably 10 or more, still more preferably 20 or more, and particularly preferably 40 or more. When the hydroxyl value of the fluorine-containing oligomer is 1 or more, the interaction between the fluorine-containing oligomer and the adhesive polymer is strengthened, the transfer amount to the adherend is reduced, and the adhesive sheet (surface protection film) can be suppressed. of sliding (offset), lifting, peeling, etc. Furthermore, when the hydroxyl value is 20 or more, it is more excellent in contamination resistance (low contamination property), which is preferable. In addition, the hydroxyl value of the fluorine-containing oligomer is preferably 500 or less, and more preferably 400 or less. When the hydroxyl value of the aforementioned fluorine-containing oligomer exceeds 500, the reaction between the fluorine-containing oligomer and the cross-linking agent will proceed preferentially, the reaction between the original cross-linking agent and the adhesive polymer will be hindered, and the cohesion may be reduced. Therefore it is not preferable.

Specific examples of the aforementioned fluorine-containing oligomers include, for example, commercially available trade names Megafac F-477, F-556, F-559, F-562, F-563, F-569, F- 571 (the above are manufactured by DIC Corporation), etc. These compounds may be used alone or in combination of two or more.

With respect to 100 parts by mass of the adhesive polymer (which is a base polymer, such as (meth)acrylic polymer, urethane polymer, polysiloxane polymer, etc.) constituting the aforementioned adhesive composition, the aforementioned The content of the fluorine-containing oligomer is preferably 0.01 to 10 parts by mass, more preferably 0.02 to 8 parts by mass, still more preferably 0.04 to 7 parts by mass, and most preferably 0.06 to 6 parts by mass . When it exists in the said range, after bonding the adhesive sheet of this invention to an optical member etc., since it can suppress sliding (shift), a lift, peeling, etc., and it is excellent in the light peeling effect, it is preferable. In addition, in order to satisfy the appearance as an adhesive sheet (surface protection film), the content of the fluorine-containing oligomer is preferably 0.01 to 5.5 parts by mass relative to 100 parts by mass of the adhesive polymer.

＜Crosslinking agent＞ In the pressure-sensitive adhesive sheet (surface protection film) of the present invention, the pressure-sensitive adhesive composition preferably contains a crosslinking agent. Moreover, in this invention, the said adhesive composition can be used as an adhesive layer. For example, when the aforementioned adhesive composition is an acrylic adhesive containing the aforementioned (meth)acrylic polymer, the constituent units, constituent ratios, and crosslinking agents of the aforementioned (meth)acrylic polymer are appropriately adjusted. The selection and addition ratio of , and cross-linking can obtain an adhesive sheet (adhesive layer) with more excellent heat resistance.

As the crosslinking agent used in the present invention, isocyanate compounds, epoxy compounds, melamine-based resins, aziridine derivatives, metal chelate compounds, and the like can be used, and in particular, isocyanate compounds are preferably used. In addition, these compounds may be used alone or in combination of two or more.

二

三酮鍵等將前述異氰酸酯化合物改質後的多異氰酸酯改質體。以市售品為例，可以列舉商品名Takenate 300S、Takenate 500、Takenate 600、Takenate D165N、Takenate D178N(以上為三井化學公司製造)；Sumidur T80、Sumidur L、Desmodule N3400(以上為住化拜耳胺甲酸乙酯公司製造)；Millionate MR、Millionate MT、Coronate L、Coronate HL、Coronate HX(以上為東曹公司製造)等。這些異氰酸酯化合物可以單獨使用，也可以混合使用兩種以上，也可以並用二官能的異氰酸酯化合物與三官能以上的異氰酸酯化合物。通過並用交聯劑，能夠兼顧黏著性與耐回彈性(對曲面的接著性)，能夠得到接著可靠性更優異的黏著片。Examples of the isocyanate compound include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), and dimer acid diisocyanate; cyclopentylene diisocyanate; Alicyclic isocyanates such as isocyanate, cyclohexylene diisocyanate, isophorone diisocyanate (IPDI), 1,3-bis(isocyanatomethyl)cyclohexane; 2,4-toluene diisocyanate, 4 ,4'-diphenylmethane diisocyanate, stubble diisocyanate (XDI) and other aromatic isocyanates; using allophanate bond, biuret bond, isocyanurate bond, uretdione bond, Urea bond, carbodiimide bond, uretonimide bond,

two

A modified polyisocyanate obtained by modifying the aforementioned isocyanate compound with a triketone bond or the like. Taking commercially available products as examples, there are trade names Takenate 300S, Takenate 500, Takenate 600, Takenate D165N, Takenate D178N (the above are manufactured by Mitsui Chemicals); Sumidur T80, Sumidur L, Desmodule N3400 (the above are Sumika Bayeramic Acid Ethyl Ester Co., Ltd.); Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (the above are manufactured by Tosoh Corporation), etc. These isocyanate compounds may be used alone or in combination of two or more, or a difunctional isocyanate compound and a trifunctional or more isocyanate compound may be used in combination. By using a crosslinking agent in combination, both adhesiveness and resilience resistance (adhesion to a curved surface) can be achieved, and an adhesive sheet having more excellent adhesive reliability can be obtained.

In addition, when using the above-mentioned isocyanate compound (a difunctional isocyanate compound and a trifunctional or higher isocyanate compound) in combination, the blend ratio (mass ratio) of the two compounds is preferably [difunctional isocyanate compound]/[ Trifunctional or higher isocyanate compound] (mass ratio) is blended at 0.1/99.9 to 50/50, more preferably 0.1/99.9 to 20/80, still more preferably 0.1/99.9 to 10/90, particularly preferably 0.1/ 99.9 to 5/95, most preferably 0.1/99.9 to 1/99. By adjusting and blending within the aforementioned range, it is a preferable aspect to obtain an adhesive layer excellent in adhesiveness and repulsion resistance.

Examples of the epoxy compound include N,N,N',N'-tetraglycidyl-m-xylylenediamine (trade name TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.), 1,3- Bis(N,N-diglycidylaminomethyl)cyclohexane (trade name TETRAD-C, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and the like.

As said melamine type-resin, hexamethylol melamine etc. are mentioned. As an aziridine derivative, the trade name HDU, TAZM, and TAZO (the above are made by Mutual Pharmaceutical Co., Ltd.) which are commercially available products, for example, can be mentioned.

As said metal chelate compound, as a metal component, aluminum, iron, tin, titanium, nickel, etc. are mentioned; As a chelate component, acetylene, methyl acetoacetate, ethyl lactate, etc. are mentioned.

The content of the crosslinking agent used in the present invention is, for example, preferably 0.01 to 20 parts by mass, and more preferably 0.1 to 15 parts by mass with respect to 100 parts by mass of the (meth)acrylic polymer. , more preferably 0.5 parts by mass to 10 parts by mass, particularly preferably 1 part by mass to 6 parts by mass. When the content is less than 0.01 parts by mass, the formation of crosslinking by the crosslinking agent becomes insufficient, and the cohesive force of the obtained adhesive layer tends to be reduced, and sufficient heat resistance may not be obtained, And become the cause of glue residue. On the other hand, when the content exceeds 20 parts by mass, the cohesive force of the polymer is large, the fluidity is lowered, and there is a tendency that the wetting of the adherend (for example, the polarizing plate) is insufficient, and the adherend and the adhesion The cause of the bulge between the adhesive layers (adhesive composition layers). In addition, these crosslinking agents may be used alone or in combination of two or more.

The adhesive composition may further contain a crosslinking catalyst for making any of the above-mentioned crosslinking reactions proceed more efficiently. As the crosslinking catalyst, for example, tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate; tris(acetylacetonato)iron, tris(hexane-2,4-dione ) iron, tris(heptane-2,4-dione)iron, tris(heptane-3,5-dione)iron, tris(5-methylhexane-2,4-dione) Iron, Tris(octane-2,4-diketone)iron, Tris(6-methylheptane-2,4-diketonato)iron, Tris(2,6-dimethylheptane-3, 5-diketone)iron, tris(nonane-2,4-diketone)iron, tris(nonane-4,6-diketonato)iron, tris(2,2,6,6-tetramethyl) base heptane-3,5-dione)iron, tris(tridecane-6,8-dione)iron, tris(1-phenylbutane-1,3-dione)iron, tris(1-phenylbutane-1,3-dione)iron (Hexafluoroacetylacetonate)iron, tris(ethylacetate)iron, tris(acetate-n-propylacetate)iron, tris(acetoacetate-isopropyl)iron, tris(acetoacetate-n-butyl) ) iron, tris(tertiary butylacetate) iron, tris(tertiary butylacetate) iron, tris(methyl propylacetate) iron, tris(ethyl acetoxyacetate) iron, n-Propyl acetate) iron, tris (propionyl acetate isopropyl) iron, tris (propionate n-butyl acetate) iron, tris (propionyl acetate secondary butyl) iron, tris (propionyl acetate tertiary butyl) ester) iron, tris(acetoxybenzyl acetate) iron, tris(dimethylmalonate) iron, tris(diethylmalonate) iron, trimethoxy iron, triethoxy iron, triisopropyl Iron oxide catalysts such as ferric oxide and ferric chloride. These crosslinking catalysts may be used alone or in combination of two or more.

The content of the crosslinking catalyst is not particularly limited, but for example, relative to 100 parts by mass of the (meth)acrylic polymer, it is preferably about 0.0001 part by mass to about 1 part by mass, more preferably 0.001 part by mass to 0.5 part by mass . When it exists in the said range, the rate of the crosslinking reaction at the time of forming an adhesive agent layer becomes high, and the pot life of an adhesive agent composition also becomes long, and it is a preferable aspect.

Moreover, the compound which produces keto-enol tautomerism may be contained in the said adhesive composition. For example, in an adhesive composition containing a cross-linking agent or an adhesive composition in which a cross-linking agent can be blended and used, it is preferable to adopt an aspect that contains the compound that produces the keto-enol tautomerism. Thereby, excessive viscosity increase and gelation of the adhesive composition after blending of the crosslinking agent can be suppressed, and the effect of prolonging the pot life of the adhesive composition can be achieved. In the case where at least an isocyanate compound is used as the aforementioned crosslinking agent, it is particularly meaningful to contain a compound which produces keto-enol tautomerism. For example, this technique can be preferably applied when the adhesive composition is in the form of an organic solvent solution or a solvent-free form.

As the aforementioned keto-enol tautomerism compound, various β-dicarbonyl compounds can be used. Specific examples include acetone acetone, 2,4-hexanedione, 3,5-heptanedione, 2-methylhexane-3,5-dione, 6-methylheptane β-diketones such as alkane-2,4-dione, 2,6-dimethylheptane-3,5-dione; methyl acetonitrile, ethyl acetate, isopropyl acetoacetate , Acetyl acetates such as tertiary butyl acetyl acetate; Acetyl acetates such as ethyl acetate, ethyl acetate, isopropyl acetate, tertiary butyl acetate, etc.; Isobutyl acetate Isobutyryl acetates such as ethyl acetate, ethyl isobutyrate, isopropyl isobutyrate acetate, tertiary butyl isobutyrate acetate, etc.; propylene glycol such as methyl malonate and ethyl malonate acid esters; etc. Among them, acetylacetone and acetoacetate are mentioned as preferable compounds. The compounds that generate keto-enol tautomerism may be used alone or in combination of two or more.

With respect to 100 parts by mass of the (meth)acrylic polymer, the content of the compound that produces keto-enol tautomerism can be, for example, 0.1 parts by mass to 20 parts by mass, and usually 0.5 parts by mass to 15 parts by mass (for example, 1 part by mass to 10 parts by mass) is suitable. When the amount of the compound is too small, it may be difficult to exhibit a sufficient use effect. On the other hand, when the above-mentioned compound is used in an unnecessarily large amount, it may remain in the adhesive layer and reduce the cohesion force.

In addition, the adhesive composition may contain other known additives, for example, powders such as lubricants, colorants, pigments, plasticizers, tackifiers, low molecular weight polymers, surface Lubricant, leveling agent, antioxidant, corrosion inhibitor, light stabilizer, ultraviolet absorber, polymerization inhibitor, silane coupling agent, inorganic or organic filler, metal powder, particles, foil, etc.

<Adhesive layer and adhesive sheet (surface protection film)> The pressure-sensitive adhesive sheet of the present invention is obtained by forming the pressure-sensitive adhesive layer on at least one side of the base film. In this case, the cross-linking of the pressure-sensitive adhesive composition is usually performed after the application of the pressure-sensitive adhesive composition. The adhesive layer containing the adhesive composition after crosslinking is transferred to a base film or the like.

In addition, the method of forming the adhesive layer on the base film is not particularly limited. For example, it can be produced by applying the above-mentioned adhesive composition (solution) to the base film, drying and removing the polymerization solvent, etc. An adhesive layer is formed on the material film. Thereafter, curing may be performed for the purpose of adjusting the component transfer of the adhesive layer, adjusting the crosslinking reaction, and the like. In addition, when the adhesive composition is coated on the base film to produce an adhesive sheet, one or more solvents other than the polymerization solvent may be newly added to the adhesive composition so that the adhesive composition can be uniformly coated on the base film. superior.

Moreover, as the formation method of the adhesive bond layer at the time of manufacture of the adhesive sheet of this invention, the well-known method used for manufacture of adhesive tapes can be used. Specifically, a roll coating method, a gravure coating method, a reverse coating method, a roll brushing method, a spray coating method, an air knife coating method, an extrusion coating method using a die coater, etc. are mentioned, for example.

The pressure-sensitive adhesive sheet of the present invention is usually produced so that the thickness of the pressure-sensitive adhesive layer may be about 3 μm to about 100 μm, preferably about 5 μm to about 50 μm. When the thickness of the adhesive layer is within the above-mentioned range, it is easy to obtain an appropriate balance between releasability and adhesiveness, which is preferable.

In addition, the adhesive sheet of the present invention preferably has a total thickness of 8 μm to 300 μm, more preferably 10 μm to 200 μm, and most preferably 20 μm to 100 μm. When it exists in the said range, adhesive property (repeelability, adhesiveness, etc.), workability|operativity, and an external appearance property are excellent, and it is a preferable aspect. In addition, the said total thickness means the sum total of the thickness of all layers, such as a base film, an adhesive bond layer, and other layers.

＜Separate parts＞ In the pressure-sensitive adhesive sheet of the present invention, it is preferable that a separator is adhered to the surface opposite to the surface of the pressure-sensitive adhesive layer that is in contact with the base film. For the separator, the separator can be attached to the surface of the adhesive layer for the purpose of protecting the adhesive surface as required.

As a material constituting the separator, there are paper and a plastic film, and a plastic film is preferably used from the viewpoint of excellent surface smoothness. The film is not particularly limited as long as it can protect the adhesive layer, and examples thereof include polyethylene films, polypropylene films, polybutene films, polybutadiene films, and polymethylpentene. Film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, urethane film, ethylene-vinyl acetate copolymer film, etc.

The thickness of the separator is usually about 5 μm to about 200 μm, preferably about 10 μm to about 100 μm. When it is in the said range, since the workability|operativity of sticking to an adhesive bond layer and peeling workability from an adhesive bond layer are excellent, it is preferable. The separation part can also be subjected to mold release and antifouling treatment using polysiloxane-based, fluorine-containing, long-chain alkyl or fatty acid amide-based mold release agents, silica powder, etc.; coating type , kneading type, evaporation type and other antistatic treatment.

Further, in the adhesive sheet of the present invention, it is preferable that the fluorine-containing oligomer is present (coated/laminated) on the surface of the separator in contact with the adhesive layer (see FIG. 1 ). By the presence of the fluorine-containing oligomer on the surface of the separator in contact with the adhesive layer, when the separator is adhered to the adhesive layer, the fluorine-containing oligomer is removed from the surface of the separator. It is transferred (transferred) to the surface of the aforementioned adhesive layer, and after the adhesive layer is attached to the adherend (such as a polarizing plate), a light peeling effect due to the low surface free energy of the fluorine site can be achieved. , and acts as a tackifier resin to improve adhesiveness, and can realize the suppression of sliding (offset), lifting, and peeling of the adhesive sheet (surface protective film) (both re-peelability and tackiness), which is a more preferred method. .

<Optical components> The optical member of the present invention is preferably attached (protected) by the adhesive sheet or the adhesive sheet from which the separator has been peeled off. Since the above-mentioned pressure-sensitive adhesive sheet is excellent in curl controllability and light releasability (repeelability), it can be used for surface protection applications (surface protection films) during processing, transportation, shipping, etc. boards, etc.) are useful.

Example Hereinafter, several embodiments related to the present invention will be described, but the present invention is not intended to be limited to the scope shown by the specific examples. In addition, "part" and "%" in the following description are based on mass unless otherwise specified.

In addition, each characteristic in the following description was measured or evaluated by the following methods, respectively.

<Measurement of weight average molecular weight (Mw)> The weight average molecular weight (Mw) of the polymer used was measured using a GPC apparatus (HLC-8220GPC) manufactured by Tosoh Corporation. The measurement conditions are as follows. Sample concentration: 0.2 mass % (tetrahydrofuran (THF) solution) Injection volume: 10μl Developing solution: THF Flow rate: 0.6ml/min Measurement temperature: 40℃ column: Sample column; TSKguardcolumn SuperHZ-H (1) + TSKgel SuperHZM-H (2) Reference column; TSKgel SuperH-RC (1 piece) Detector: Differential Refractometer (RI) In addition, the weight average molecular weight was calculated|required by polystyrene conversion value.

<Theoretical value of glass transition temperature (Tg)> The glass transition temperature Tg (° C.) was determined from the following formula using the following literature value as the glass transition temperature Tgn (° C.) of the homopolymer of each monomer.

Formula: 1/(Tg+273)=Σ[Wn/(Tgn+273)] [wherein, Tg(°C) represents the glass transition temperature of the copolymer, Wn(-) represents the mass fraction of each monomer, Tgn(°C) represents the glass transition temperature of the homopolymer formed from each monomer, n represents the kind of each monomer. ] Literature value: 2-ethylhexyl acrylate (2EHA): -70°C 4-Hydroxybutyl acrylate (4HBA): -32°C Acrylic (AA): 106℃

It should be noted that, as the above-mentioned literature values, "Synthesis, Design and New Application Development of Acrylic Resins" (published by the Central Business Development Center Publishing Department) and "Polymer Handbook" (John Wiley & Sons) were referred to.

<Measurement of hydroxyl value> 25 g of acetic anhydride was taken into a 100 ml volumetric flask, pyridine was added to adjust the total amount to 100 ml, and the mixture was stirred sufficiently to prepare an acetylation reagent. Next, 2 g of the sample (fluorine-containing oligomer) was weighed into a flat-bottomed flask, and a total amount of 5 ml of the acetylating reagent was added thereto. The above flask was heated in a 100°C bath for 70 minutes and then cooled naturally. A few drops of phenolphthalein solution were added to this as an indicator, and titration was performed with a 0.5 mol/l potassium hydroxide ethanol solution, and the end point was the time when the light red color of the indicator continued for about 30 seconds. The hydroxyl value was calculated from the following formula. Hydroxyl value (mgKOH/g)=[(B-C)×f×28.05]/S+D B: The amount of 0.5mol/L potassium hydroxide ethanol solution used in the blank test (mL) C: Amount (mL) of 0.5 mol/L potassium hydroxide ethanol solution used in the sample f: factor of 0.5mol/L potassium hydroxide ethanol solution S: weight of the sample (g) D: acid value 28.05: 1/2 of the molecular weight of potassium hydroxide 56.11

＜Production of acrylic film＞ (Manufacture of resin composition) The resin was produced using a tandem reaction extruder in which two extrusion reactors were arranged in series. As for the tandem reaction extruder, a coaxial meshing type having a diameter of 75 mm and an L/D (ratio of the length L to the diameter D of the extruder) of 74 was used together with the first extruder and the second extruder. The twin-screw extruder used a constant feeder (manufactured by Kubota Corporation) to supply the raw material resin to the raw material supply port of the first extruder. In addition, the decompression degree of each vent in the first extruder and the second extruder was adjusted to -0.095 MPa. In addition, the 1st extruder and the 2nd extruder are connected by a pipe with a diameter of 38mm and a length of 2m, and the internal pressure control mechanism of the parts connecting the resin discharge port of the 1st extruder and the raw material supply port of the 2nd extruder is used. Constant flow pressure valve. The resin (strand) discharged from the second extruder is cooled in a cooling conveyor, and then cut into pellets in a pelletizer. Here, in order to confirm the internal pressure regulation or extrusion fluctuation of the parts connecting the resin discharge port of the first extruder and the raw material supply port of the second extruder, the first extruder outlet, the first extruder and the second extruder A resin pressure gauge is installed at the center of the extruder connection part and at the exit of the second extruder. For the first extruder, an imide resin intermediate 1 was produced using polymethyl methacrylate resin (Mw: 105,000) as a raw material resin and monomethylamine as an imidizing agent. At this time, the temperature of the highest temperature part of the extruder was set to 280° C., the screw rotation speed was set to 55 rpm, the feed rate of the raw resin was set to 150 kg/hour, and the addition amount of monomethylamine was set to 100 parts by mass of the raw resin. 2.0 parts by mass. In addition, a constant flow pressure valve was installed in front of the raw material supply port of the second extruder, and the pressure of the monomethylamine injection part of the first extruder was adjusted to 8 MPa. Next, the imide intermediate 1 was supplied to the second extruder, and the imidization reaction reagent and by-products remaining in the rear exhaust port and the vacuum exhaust port were devolatilized, and then added as an esterification agent The mixed solution of dimethyl carbonate and triethylamine to produce imide resin intermediate 2. At this time, the temperature of each barrel of the extruder was set to 260° C., the rotational speed of the screw was set to 55 rpm, and the addition amount of dimethyl carbonate was set to 3.2 parts by mass relative to 100 parts by mass of the raw resin, based on 100 parts by mass of the raw resin parts The addition amount of triethylamine was set to 0.8 parts by mass. Further, with regard to the imide intermediate 2, the esterification agent was removed through the exhaust port, then extruded from the strand die, cooled in a water tank, and then granulated in a granulator, thereby obtaining resin composition. The imidization rate of this resin composition was 3.7%, and the acid value was 0.29 mmol/g.

類紫外線吸收劑(艾迪科公司製造，商品名：T-712)0.62質量份在220℃下混合，從而製作了樹脂顆粒。將所得到的樹脂顆粒在100.5kPa、100℃下乾燥12小時，利用單螺桿擠出機在模頭溫度270℃下從T型模頭擠出，從而成形為薄膜狀(厚度160μm)。 進一步地，將前述薄膜沿其運送方向在150℃的氣體環境下拉伸(厚度80μm)，接著，沿與薄膜運送方向正交的方向在150℃的氣體環境下拉伸，從而得到了厚度40μm的丙烯酸薄膜(丙烯酸類樹脂薄膜)。(Manufacture of Acrylic Film) Using a twin-screw kneader, 100 parts by mass of the aforementioned resin composition and three

0.62 parts by mass of an ultraviolet absorber-like absorber (manufactured by Adico Corporation, trade name: T-712) was mixed at 220° C. to prepare resin pellets. The obtained resin pellets were dried at 100.5 kPa and 100° C. for 12 hours, and extruded from a T-die at a die temperature of 270° C. with a single-screw extruder to form a film (thickness 160 μm). Further, the aforementioned film was stretched in a gas atmosphere at 150° C. along the transport direction (thickness of 80 μm), and then stretched in a gas atmosphere at 150° C. in a direction orthogonal to the transport direction of the film to obtain a thickness of 40 μm. acrylic film (acrylic resin film).

<Preparation of acrylic polymer (1)> 91 parts by mass of 2-ethylhexyl acrylate (2EHA), 9 parts by mass of 4-hydroxybutyl acrylate (4HBA), and acrylic acid (AA) were put into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction pipe, and a cooler. 0.02 parts by mass, 0.2 parts by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 150 parts by mass of ethyl acetate were introduced while stirring slowly, and the liquid temperature in the flask was kept at about 65 The polymerization reaction was carried out at °C for 6 hours to prepare an acrylic polymer (1) solution (40% by mass). The weight average molecular weight (Mw) of the said acrylic polymer (1) was 540,000, and the glass transition temperature (Tg) was -67 degreeC.

<Preparation of acrylic polymer (2)> 98.5 parts by mass of 2-ethylhexyl acrylate (2EHA), 1.5 parts by mass of 4-hydroxybutyl acrylate (4HBA), and acrylic acid (AA) were put into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction pipe, and a cooler. 0.006 part by mass, 0.2 part by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 150 parts by mass of ethyl acetate, nitrogen gas was introduced while stirring slowly, and the liquid temperature in the flask was kept at about 65°C And the polymerization reaction was performed for 6 hours, and the acrylic polymer (2) solution (40 mass %) was prepared. The weight average molecular weight (Mw) of the said acrylic polymer (2) was 480,000, and the glass transition temperature (Tg) was -70 degreeC.

<Example 1> [Preparation of acrylic adhesive solution] The above-mentioned acrylic polymer (1) solution (40 mass %) was diluted to 20 mass % with ethyl acetate, and ethyl acetate was added to 500 mass parts of the solution (solid content 100 mass parts) to prepare a fluorine-containing oligomer. 50 parts by mass (5 parts by mass of solid content) of a solution (Megafac F-563, manufactured by DIC Corporation) diluted to 10%, isocyanuric acid of hexamethylene diisocyanate which is a trifunctional isocyanate compound as a crosslinking agent 3 parts by mass of ester (Coronate HX, manufactured by Tosoh Corporation) (3 parts by mass of solid content), and 3 parts by mass of dioctyltin dilaurate (1 mass % ethyl acetate solution) as a crosslinking catalyst (3 parts by mass of solid content) 0.03 parts by mass), mixed and stirred to prepare an acrylic adhesive solution.

[Production of antistatic treatment film] Poly(3,4-ethylenedioxythiophene) ( PEDOT)/polystyrenesulfonic acid (PSS) (Baytron P, manufactured by H.C. Starck Co., Ltd.) was 100 parts by mass in terms of solid content, and 10 parts by mass of hexamethylol melamine as a crosslinking agent was added to water in terms of solid content. /ethanol (1/1) mixed solvent, stir for about 20 minutes, and then mix well. In this way, a solution for an antistatic layer having an NV (non-volatile component) of about 0.4% was prepared. The obtained antistatic agent solution was coated on a polyethylene terephthalate (PET) film (thickness: 38 μm) using a Meyer bar, and dried at 130° C. for 1 minute to remove the solvent to form an antistatic layer ( thickness: 0.2 μm), thereby producing an antistatic treatment film.

[Production of adhesive sheet (surface protection film)] The said acrylic pressure-sensitive adhesive solution was apply|coated to the surface opposite to the antistatic processing surface of the said antistatic treatment film, and it heated at 130 degreeC for 2 minutes, and formed the pressure-sensitive adhesive layer with a thickness of 15 micrometers. Next, the polysiloxane-treated surface of the polyethylene terephthalate film (separator, thickness 25 μm), which had been polysiloxane-treated on one side, was pasted on the surface of the above-mentioned adhesive layer, thereby producing an adhesive sheet ( surface protection film) (see Figure 2).

<Examples 2 to 6> The fluorine-containing oligomer described in Table 1 was used instead of the fluorine-containing oligomer Megafac F-563 used in Example 1, and the blending amount described in Table 1 was used by the same method as in Example 1. adhesive sheet.

<Example 7> An acrylic polymer (2) was used in place of the acrylic polymer (1) used in Example 2, and Megafac F-562 was used, and an adhesive sheet was produced in the same manner as in Example 2 at the blending amount shown in Table 1. .

<Example 8> Using the Megafac F-569 used in Example 3, an adhesive sheet was produced by the same method as in Example 3 at the blending amount described in Table 1.

<Examples 9 to 11> The Megafac F-562 used in Example 2 was used in combination with other fluorine-containing oligomers, and an adhesive sheet was produced by the same method as in Example 2 in the blending amount shown in Table 1.

<Example 12> The fluorine-containing oligomer described in Table 1 was used instead of Megafac F-562 used in Example 7, and an adhesive sheet was produced in the same manner as in Example 7 in the blending amount described in Table 1.

<Examples 13 and 14> The Megafac F-562 used in Example 7 was used in combination with other fluorine-containing oligomers, and an adhesive sheet was produced by the same method as in Example 7 in the blending amount described in Table 1.

<Examples 15 and 16> Using the Megafac F-562 used in Example 2, an adhesive sheet was produced by the same method as in Example 2 at the blending amount described in Table 1.

<Examples 17 and 18> Using the Megafac F-569 used in Example 3, an adhesive sheet was produced by the same method as in Example 3 at the blending amount described in Table 1.

<Comparative Examples 1 to 2> An adhesive sheet was produced by the same method as in Example 1, except that the fluorine-containing oligomer described in Table 1 was used instead of the fluorine-containing oligomer used in Example 1.

<Comparative Example 3> An adhesive sheet was produced in the same manner as in Example 1, except that the fluorine-containing oligomer used in Example 1 was not used.

Table 1 and Table 2 show the results of the above-mentioned blending contents and various measurements and evaluations of the adhesive sheets of Examples and Comparative Examples. In addition, the compounding quantity in Table 1 represents an active ingredient. In addition, in Examples and Comparative Examples other than Example 1, the crosslinking agent and the crosslinking catalyst whose blending amounts are not described in Table 1 were blended in the same amounts as those in Example 1. In addition, the abbreviation in Table 1 is demonstrated below.

[Fluorine-containing oligomer] F-563: Fluorine-containing oligomer, hydroxyl value: 120 mgKOH/g, manufactured by DIC Corporation, trade name: Megafac F-563 F-562: Fluorine-containing oligomer, hydroxyl value 56 mgKOH/g, manufactured by DIC Corporation, trade name: Megafac F-562 F-569: Fluorine-containing oligomer, hydroxyl value of 59 mgKOH/g, manufactured by DIC Corporation, trade name: Megafac F-569 F-477: Fluorine-containing oligomer, hydroxyl value: 18 mgKOH/g, manufactured by DIC Corporation, trade name: Megafac F-477 F-556: Fluorine-containing oligomer, hydroxyl value: 14 mgKOH/g, manufactured by DIC Corporation, trade name: Megafac F-556 F-559: Fluorine-containing oligomer, hydroxyl value 11 mgKOH/g, manufactured by DIC Corporation, trade name: Megafac F-559 F-565: Fluorine-containing oligomer, hydroxyl value 0mgKOH/g, manufactured by DIC Corporation, trade name: Megafac F-565 R-40: Fluorine-containing oligomer, hydroxyl value 0mgKOH/g, manufactured by DIC Corporation, trade name: Megafac R-40

Table 1

<Shearing force> The adhesive sheet of each example was cut into a size of 10 mm in width and 100 mm in length, the separator was peeled off, and the adhesive layer of the adhesive sheet was attached to the above-mentioned acrylic film so that the bonding area of the adhesive layer of the above-mentioned adhesive sheet was 1 cm ² . (width: 25 mm, length: 100 mm), and stretched in the shearing direction at a tensile speed of 0.06 mm/min at 23°C, and the maximum load (N/cm ² ) at this time was taken as the shearing force.

In the adhesive sheet of the present invention, it is preferable that the shear force of the adhesive layer used in the adhesive sheet to the above-mentioned acrylic film (for example, a polarizing plate formed of an acrylic film) at 23° C.×50% RH is 5 N/cm ² Above, more preferably 5 N/cm ² to 50 N/cm ² , and still more preferably 7 N/cm ² to 40 N/cm ² . By adjusting the shearing force to be 5 N/cm ² or more, after sticking to the adherend, sliding (offset), lifting, peeling, etc. can be suppressed, and curl controllability is excellent, which is a preferable aspect.

<Measurement of low-speed peel force> The adhesive sheet, which was left to stand in an environment of 23° C.×50% RH for 24 hours and then cut into a width of 25 mm and a length of 100 mm, was laminated to the above-mentioned acrylic film (width: 70 mm, 0.25 MPa pressure and 0.3 m/min speed). length: 100 mm), thereby producing an evaluation sample. After the above lamination, it was left to stand in an environment of 23°C x 50%RH for 30 minutes, and then the low-speed peeling at a peeling speed of 0.3 m/min (low-speed peeling) and a peeling angle of 180° was measured using a universal tensile tester. Peel force (N/25mm). The measurement was performed in an environment of 23°C x 50% RH.

The pressure-sensitive adhesive sheet of the present invention preferably has a 180° peel adhesion force (stretching) of the pressure-sensitive adhesive layer used in the pressure-sensitive adhesive sheet to the above-mentioned acrylic film (for example, a polarizing plate formed of an acrylic film) at 23° C.×50% RH. Speed 0.3 m/min: low-speed peeling force) is 0.15 N/25 mm or less, more preferably 0.01 N/25 mm to 0.15 N/25 mm, still more preferably 0.02 N/25 mm to 0.14 N/25 mm. By adjusting the aforementioned peeling adhesive force (tensile speed 0.3 m/min) to 0.15 N/25 mm or less, the peeling operation becomes easy (repeelability) without the need for an adhesive sheet (surface protection film), and the It is a preferable aspect because it can prevent the damage of the to-be-adhered body and the like.

<Presence of contamination (contamination resistance)> The adhesive sheet of each example was cut into a size of 50 mm in width and 80 mm in length, the separator was peeled off, and the acrylic film (width: 70 mm, length: 100 mm) was press-bonded with a hand roll while blowing air bubbles to produce evaluated samples. The said evaluation sample was left to stand in the environment of 70 degreeC for 120 hours, and then the adhesive sheet was peeled off from the adherend by hand, and the traces of air bubbles on the surface of the adherend at this time were visually observed. In addition, for evaluation, the case where no bubble trace was observed was evaluated as ○ (no problem in actual use), and the case where bubble trace was observed only under a fluorescent lamp in a dark room was evaluated as △ (actual use). No problem), and the case where bubble traces were observed under a normal indoor fluorescent lamp was evaluated as × (problem in practical use).

Table 2

From the above Table 2, it was confirmed that in all the examples, the shear force and the low-speed peeling force were the expected results, and the curl controllability, the light peelability (repeelability) were excellent, and the stain resistance was excellent. In addition, it was confirmed that in the case of the Examples using the fluorine-containing oligomer having a hydroxyl value of 20 or more, the shear force and contamination resistance were more excellent.

On the other hand, it was confirmed from Table 2 above that in Comparative Example 1 and Comparative Example 2, since a fluorine-containing oligomer having a hydroxyl value of less than 1 (hydroxyl value of 0) was used, the shear force and contamination resistance were poor, In Comparative Example 3, since the fluorine-containing oligomer was not used, the low-speed peeling force was high, and the light peelability (repeelability) was poor.

industrial availability The pressure-sensitive adhesive sheet disclosed herein is suitable as a surface protection film used in the manufacture, transportation of optical members used as constituent elements of liquid crystal display panels, plasma display panels (PDPs), organic electroluminescence (EL) displays, and the like protect the optical member from time to time. In particular, it is useful as a surface protection film (optical surface protection film) applied to optical members such as polarizers, wave plates, retardation plates, optical compensation films, brightness enhancement films, light diffusion sheets, and reflective sheets for liquid crystal display panels. .

1‧‧‧Adhesive Sheet (Surface Protection Film) with Separator 2‧‧‧Antistatic treatment film 11‧‧‧Separator 12‧‧‧Fluorine-containing oligomer coating film 13‧‧‧Adhesive layer 14‧‧‧Substrate film 15‧‧‧Antistatic layer

FIG. 1 is a schematic cross-sectional view showing a configuration example of an adhesive sheet (surface protective film) of the present invention. 2 is a schematic cross-sectional view showing a configuration example of the adhesive sheet (surface protective film) of the present invention.

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Claims (5)

An adhesive composition is characterized in that: it contains an adhesive polymer and a fluorine-containing oligomer with a hydroxyl value of 1 or more, the aforementioned adhesive polymer is a (meth)acrylic polymer; the aforementioned (meth)acrylic acid The polymer contains a hydroxyl group-containing (meth)acrylic monomer as a raw material monomer; and the (meth)acrylic polymer is polymerized relative to 100% by mass of the total amount of monomer components constituting the (meth)acrylic polymer. The product contains 0.1 to 25% by mass of the aforementioned hydroxyl group-containing (meth)acrylic monomer. An adhesive sheet, characterized in that: at least one side of the base film has an adhesive layer formed by the adhesive composition of claim 1, and the aforementioned fluorine-containing low-temperature polymer. The pressure-sensitive adhesive sheet according to claim 2, wherein a separator is stuck on the opposite surface of the surface of the pressure-sensitive adhesive layer that is in contact with the base film. The pressure-sensitive adhesive sheet according to claim 3, wherein the fluorine-containing oligomer is present on the surface of the separator that is in contact with the pressure-sensitive adhesive layer. An optical member characterized in that: the adhesive sheet according to claim 2 or the adhesive sheet obtained by peeling off the separation piece from the adhesive sheet according to claim 3 or claim 4 is affixed.

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