KR20110057210A - Surface-protective film and laminate - Google Patents

Abstract

The surface protective film of the present invention is a surface protective film having an adhesive layer on one side of the substrate, wherein the adhesive layer satisfies a predetermined relationship between the storage modulus at 150 ° C. and the storage modulus at 20 ° C., Moreover, tan delta maximum temperature is -5 degrees C or less. According to the present invention, when the adhesiveness is excellent in the initial adhesion to the surface of the to-be-protected object such as a metal plate, a decorative plate, a plastic plate, or a glass plate, and is used for heat treatment, especially high temperature heating, the adhesive force increases even after the heat treatment. It is possible to provide a surface protective film which is less likely to cause a residue to remain on the surface of the to-be-protected object upon peeling from the to-be-protected object, and does not cause peeling phenomenon such as lifting.

Description

Surface-protective film and laminate

The present invention is a surface protection film used to temporarily protect the surface when processing, transporting, storing or the like of a metal plate, a decorative plate, a plastic plate, a glass plate, and the like, and the surface protective film adhered to It relates to a laminate.

Generally, a surface protection film used to temporarily protect a surface of a metal plate, a decorative plate, a plastic plate, a glass plate, or the like when processing, transporting or storing a plastic plate, and a synthetic resin-based adhesive on a substrate such as a plastic film. It is known that the pressure-sensitive adhesive layer formed by adding a crosslinking agent and performing crosslinking treatment is known (see Patent Document 1).

Japanese Patent Laid-Open No. 63-225677 (Example)

However, although the adhesiveness of the initial stage of sticking is favorable such a surface protection film, the adhesiveness with time progress after sticking tends to increase. Therefore, the surface protection film after use cannot be peeled easily from the to-be-protected object, and it takes time for the peeling work, and in some cases, the surface protective film is left in a part of the adhesive layer of the surface protection film. This occurs, or there was a problem that the surface protection film is stretched and broken.

In particular, the to-be-protected material to which the surface protection film is affixed is exposed to the high temperature state of about 100-150 degreeC in the thermoforming process, the drying process after coating, etc., or it is preserved for a long time in the medium temperature state of about 40-60 degreeC. In the case, the adhesive force rises remarkably with time.

In addition, there is a problem that peeling phenomenon such as lifting occurs due to the heat treatment during the thermoforming processing or the drying step after coating (particularly in the case of the high temperature state as described above).

Therefore, the present invention is excellent in the initial adhesion to the surface of the protected material such as metal plate, decorative plate, plastic plate, glass plate, and also used in heat treatment, especially high temperature heating, the adhesive strength even after the heat treatment To provide a surface protective film which is less likely to remain on the surface of the to-be-protected object during peeling from the to-be-protected object and does not cause peeling phenomenon such as lifting, and a laminate having the surface protective film adhered thereto. The purpose.

The surface protective film of the present invention is a surface protective film having an adhesive layer on one side of the substrate, wherein the pressure difference between the storage modulus at 150 ° C. and the storage modulus at 20 ° C. satisfies Equation 1, In addition, the tan δ maximum temperature is -5 ° C or less.

[In formula, G '(150) is a storage modulus in 150 degreeC, G' (20) is a storage modulus in 20 degreeC. Tan δ is a value obtained by dividing the loss modulus by the storage modulus.]

Preferably, the pressure-sensitive adhesive layer is characterized in that tan δ at 100 ° C to 150 ° C is 0.1 or less.

Further, preferably, the surface protection film of the present invention bonds the surface having the pressure-sensitive adhesive layer of the surface protection film and a stainless steel plate (SUS304 steel plate specified in JIS G4305) to 30 ° C in an environment of 150 ° C. After leaving for a minute, the adhesive force (180-degree peeling adhesive force in JIS Z0237: 2000) of the surface protection film to the stainless steel plate is 0.1 N / 50 mm to 1 N / 50 mm.

In addition, when the response of the stress to the sinusoidal deformation of the viscoelastic body is represented by a complex number, it is defined as in Equation 2, where G 'is the storage modulus, G''is the loss modulus, and G ^* is the complex modulus.

[Wherein G 'represents an elastic component of G and G' 'represents a viscous component of G.]

In addition, the storage modulus referred to in the present invention relates to the storage of energy when strain is applied to the viscoelastic material, and the loss modulus relates to the loss due to heat of energy or the like. A complex elastic modulus is a physical property value which shows the relationship of the stress and strain in a viscoelastic body. These can be calculated | required by measuring dynamic viscoelasticity. In addition, the dynamic viscoelasticity here means viscoelastic behavior which appears when the regular vibration which has a sine change is provided.

In addition, tan-delta is a ratio with respect to the storage elastic modulus of a lost elastic modulus, and is a value shown by the lost elastic modulus / storage elastic modulus. In addition, tan delta maximum temperature is the temperature (degreeC) when tan delta takes the maximum value.

The laminated body of this invention is a surface which has the adhesion layer of the said surface protection film sticking on the hard-coat layer, It is characterized by the above-mentioned. The hard coat layer is characterized in that the contact angle to water is 110 degrees or less, and the contact angle to camellia oil is 50 degrees or less. In addition, the hard coat layer is characterized in that the contact angle to the water is 50 degrees or more, and the wet tension is 27 ~ 45 mN / m.

According to this invention, since it is a surface protection film which has the adhesion layer which shows specific physical property on one side of a base material, it is excellent in the initial stage adhesiveness to the surface of to-be-protected objects, such as a metal plate, a makeup board, a plastic board, and a glass plate, and heating When used for treatments, especially those involving high temperature heating, there is little increase in adhesive strength even after the heat treatment, and it is difficult to cause the glue to remain on the surface of the to-be-protected object when peeling from the to-be-protected object, and also cause peeling phenomenon such as lifting. The surface protection film which does not make it can be provided. In particular, even when affixed to a hard coat layer, and furthermore, to a hard coat layer having specific surface properties, it is possible to provide a surface protective film which is excellent in initial adhesiveness and hardly causes glue to remain on the hard coat layer even after heat treatment. .

Hereinafter, embodiment of each component is described.

As a base material used by this invention, it does not matter especially transparent and opaque, and what is necessary is just to select suitably according to a use, but as a material, if it is transparent, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethylene, poly And plastic films such as propylene, polystyrene, triacetyl cellulose, acryl, polyvinyl chloride, and norbornene compounds. Examples of the opaque include an opaque base such as paper and synthetic paper, an opaque compound by containing a pigment and the like inside the plastic film, and a colored layer having concealability on the plastic film. .

Although the thickness of a base material cannot be said uniformly because it changes with a use, in consideration of ease of handling etc., it is 2 micrometers or more as a minimum, Preferably it is 10 micrometers or more, and an upper limit is 300 micrometers or less, Preferably it is 125 micrometers or less I think that is common.

In order to improve the adhesiveness with the adhesive layer mentioned later, such a base material carries out two adhesion processes, such as a plasma process, a corona discharge process, an ultraviolet-ray irradiation process, and a sandblasting process, or an undercoat easy adhesion process. The floor may be provided.

Next, the adhesive layer is demonstrated. The pressure-sensitive adhesive layer has a difference between the storage modulus at 150 ° C. and the storage modulus at 20 ° C., and the tanδ maximum temperature is −5 ° C. or less, preferably −10 ° C. or less, and further − It is 20 degrees C or less.

Thus, when the difference of the storage modulus in 150 degreeC and the storage modulus in 20 degreeC satisfy | fills said Formula 1, and tan tan maximum temperature is -5 degrees C or less, an adhesion layer is accompanied by heat processing, especially high temperature heating. When used for the purpose of use, it is less likely to increase the tack even after the heat treatment, and it is difficult to cause the residue to remain on the surface of the to-be-protected object upon peeling from the to-be-protected object, and to be a surface protective film that does not cause peeling phenomenon such as lifting. Can be.

That is, in the pressure-sensitive adhesive layer, the difference between the storage modulus at 150 ° C. and the storage modulus at 20 ° C. satisfies Equation 1 above, so that the pressure-sensitive adhesive layer becomes excessively soft at high temperatures and is excessively fused with the surface to be protected. Since it can be prevented from becoming easy, even if it is used for heat processing, especially the use with high temperature heating of about 100 degreeC-150 degreeC, even if it raises adhesive force little after heat processing, it is avoided at the time of peeling from a to-be-protected object. It can be said that it is hard to produce glue remaining on the surface of a protector.

In addition, since the adhesive layer obtains moderate adhesiveness by setting the tanδ maximum temperature to -5 ° C. or lower, the adhesive layer is excellent in initial adhesiveness, and even when exposed to a high temperature of about 100 ° C. to 150 ° C., it is difficult to cause peeling phenomenon such as lifting. Can be.

Moreover, it is preferable that tan-delta in 100 degreeC-150 degreeC of an adhesion layer is 0.1 or less. By setting tan δ at 100 ° C. to 150 ° C. to 0.1 or less, the behavior of the elastic component in the adhesive layer is stronger than that of the viscous component. When peeling off, it can be said that it is hard to produce more residue on the surface of a to-be-protected object. Moreover, although it changes with the material and shape of a to-be-protected object, there exists a tendency which can prevent that initial stage adhesive force becomes too high.

Moreover, it is preferable for the adhesion layer to make the adhesive force with respect to the stainless steel plate after leaving to stand in 150 degreeC environment for 30 minutes to 0.1N / 50mm-1N / 50mm. By setting the adhesive force to the stainless steel plate after being left in an environment of 150 ° C. for 30 minutes to 0.1 N / 50 mm or more, further peeling phenomenon such as lifting occurs due to heat treatment during thermoforming processing or drying step after coating. By making it difficult, it is 1 N / 50mm or less, peeling property is favorable and workability and handleability can be improved.

As an adhesive which comprises such an adhesive layer, a natural resin adhesive, a synthetic resin adhesive, etc. are used, and synthetic resin adhesives, such as an acrylic adhesive, a silicone adhesive, and a urethane type adhesive, are used preferably. Among them, a crosslinkable pressure-sensitive adhesive is preferable because it is hard to cause cohesive failure due to weather resistance and can easily control the adhesive force, and the performance of re-peelability and re-adhesiveness can be adjusted. Acrylic adhesives are particularly preferably used. It does not specifically limit about the crosslinking agent used for an adhesion layer, For example, an isocyanate type crosslinking agent, an epoxy type crosslinking agent, an imine type crosslinking agent, a metal chelate, etc. can be used.

Although the thickness of an adhesion layer is not specifically limited, In consideration of adhesiveness, adhesive force, handleability, economical efficiency, etc. after an initial stage and heating, it is 1 micrometer-30 micrometers, Preferably it is 2 micrometers-10 micrometers.

In addition to the adhesive and the crosslinking agent, the adhesive layer includes pigments, dyes, colorants, matting agents, antistatic agents, flame retardants, mold inhibitors, antirust agents, antibacterial agents, ultraviolet absorbers, light stabilizers, heat stabilizers, antioxidants, plasticizers, leveling agents, and flowable fluids. You may add additives, such as a regulator, an antifoamer, a dispersing agent, a fluorescent brightener, a storage stabilizer, and a silane coupling agent. However, it is preferable that the addition amount of these additives is a range which does not inhibit the effect of an adhesion layer.

The surface protection film of the present invention as described above is prepared by dissolving or dispersing the above-mentioned pressure-sensitive adhesive agent, crosslinking agent, and additives as necessary in a solvent to prepare a coating liquid for a pressure-sensitive adhesive layer. Obtained by applying a bar coater, a die coater, a blade coater, a spin coater, a roll coater, a gravure coater, a flow coater, a spray, a screen printing, or the like onto the substrate described above, and drying and curing by heating to form an adhesive layer. Can be. In addition, from a viewpoint of handleability, after apply | coating and drying on a base material, after providing a separator in the surface of the exposed adhesion layer, you may harden | cure by heating and prepare.

Moreover, the surface protection film of this invention can also be obtained by apply | coating and drying on the separator in the same manner to the above-mentioned adhesive layer as mentioned above, after bonding to a base material, and hardening by heating.

As an example of the use method of the surface protection film of this invention, the protection at the time of manufacture of optical members, such as a polarizing plate, the printing process, the manufacture of an electronic circuit board, the manufacture of electronic components, such as a ceramic capacitor, etc. are mentioned, for example. Can be.

As described above, the surface protective film of the present invention is a surface protective film having an adhesive layer on one side of the substrate, wherein the adhesive layer has a difference in storage modulus at 150 ° C. and storage modulus at 20 ° C. 1 satisfies and tan δ maximum temperature is -5 ℃ or less, excellent initial adhesion to the surface of the object to be protected, such as metal plate, decorative plate, plastic plate, glass plate, and also accompanied by heat treatment, especially high temperature heating When used for the purpose, the increase in the adhesive strength is small even after the heat treatment, and it is difficult to cause the residue to remain on the surface of the to-be-protected object during peeling from the to-be-protected object, and to make it difficult to generate a peeling phenomenon such as lifting.

As for the laminated body of this invention, the surface which has the adhesion layer of the said surface protection film is affixed on the sticking object.

Hereinafter, as a sticking object, it demonstrates and demonstrates the hard-coat layer used by various fields. The hard coat layer as an example can be obtained by preparing a curable composition (paint), apply | coating this to the target to-be-coated object, and hardening it.

The curable composition which can be used by this example contains a resin component. The resin component includes one or both of thermosetting resin or ionizing radiation curable resin. The thermosetting resin and the ionizing radiation curable resin are, for example, polyester resins, acrylic resins, acrylic urethane resins, polyester acrylate resins, polyurethane acrylate resins, epoxy acrylate resins, urethane resins and epoxy resins. Resin, polycarbonate resin, melamine resin, phenol resin, silicone resin, fluorine resin and the like.

In particular, the resin component preferably contains at least an ionizing radiation curable resin from the viewpoint of excellent film hardness (hard coatability) after curing. As the ionizing radiation curable resin, a photopolymerizable prepolymer crosslinked and cured by irradiation with ionizing radiation (ultraviolet or electron beam) can be used. In this example, the photopolymerizable prepolymer mentioned later may be used independently and can also be used in combination of 2 or more type.

Photopolymerizable prepolymers include a cationic polymerization type and a radical polymerization type. Examples of the cationic polymerization type photopolymerizable prepolymers include epoxy resins, vinyl ether resins, and the like. As an epoxy resin, a bisphenol-type epoxy resin, a novolak-type epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin, etc. are mentioned, for example. As the radical polymerization type photopolymerizable prepolymer, an acrylic prepolymer (hard prepolymer) having two or more acryloyl groups in one molecule and crosslinking to be a three-dimensional network structure is particularly preferably used from the viewpoint of hard coatability.

Examples of the acrylic prepolymers include urethane acrylate, polyester acrylate, epoxy acrylate, melamine acrylate, polyfluoroalkyl acrylate, silicone acrylate, and the like. A urethane acrylate type prepolymer can be obtained by esterifying the polyurethane oligomer obtained by reaction of a polyether polyol, polyester polyol, and polyisocyanate, for example by reaction with (meth) acrylic acid. As polyester acrylate type prepolymer, the hydroxyl group of the polyester oligomer which has a hydroxyl group in the both terminal obtained by condensation of polyhydric carboxylic acid and a polyhydric alcohol, for example, is esterified by (meth) acrylic acid, or it is made to polyhydric carboxylic acid, It can obtain by esterifying the hydroxyl group of the oligomer terminal obtained by adding an alkylene oxide with (meth) acrylic acid. An epoxy acrylate type prepolymer can be obtained by esterifying by the reaction of the oxirane ring of a bisphenol-type epoxy resin or novolak epoxy resin of a comparatively low molecular weight, and (meth) acrylic acid, for example.

An acrylic prepolymer can be suitably selected according to the kind, application, etc. of a to-be-coated member. In addition, although an acryl-type prepolymer can be used independently, it is preferable to add a photopolymerizable monomer in order to provide various performances, such as the improvement of crosslinking | hardenability and adjustment of hardening shrinkage.

As a photopolymerizable monomer, a monofunctional acrylic monomer (for example, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, butoxyethyl acrylate, etc.), a bifunctional acrylic monomer (for example For example, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, hydroxy pivalic acid ester neopentyl glycol diacrylate, etc.), trifunctional or more acrylic A monomer (for example, dipentaerythritol hexaacrylate, trimethylol propane triacrylate, pentaerythritol triacrylate, etc.) is mentioned. In addition, in addition to literal acrylate, "acrylate" also includes methacrylate. These photopolymerizable monomers may be used independently and can also be used in combination of 2 or more type.

The total content (solid content conversion) of the photopolymerizable prepolymer and the photopolymerizable monomer in the curable composition is preferably 40 to 99% by weight, more preferably 60 to 95% by weight, still more preferably in the total resin component. Is 80 to 90% by weight.

When forming the hard coat layer mentioned above, when hardening | curing by ultraviolet irradiation and using, it is preferable to mix | blend additives, such as a photoinitiator, a photoinitiator, and a sensitizer, in a curable composition. The compounding quantity of these additives is normally selected in the range of 0.2-10 weight part with respect to a total of 100 weight part of the photopolymerizable prepolymer and photopolymerizable monomer mentioned above.

As the resin component, a thermosetting resin may be contained in the resin component instead of or in combination with the ionizing radiation curable resin. When the thermosetting resin is contained in the resin component, a thermopolymerizable monomer or a prepolymer is used alone or in combination, and as desired, a thermal polymerization initiator, that is, a compound that generates active radical species by heating, is contained.

Moreover, as resin component, you may contain other resins, such as a thermoplastic resin, as long as it is a range which does not impair the effect of this invention other than the above-mentioned thermosetting resin and ionizing radiation curable resin.

In addition, as long as it is a range which does not inhibit the effect of this invention, you may mix | blend an additive component suitably with curable composition. As the additive component, for example, inorganic fine particles, resin fine particles, surface modifiers, lubricants, colorants, pigments, dyes, fluorescent brighteners, flame retardants, antibacterial agents, fungicides, ultraviolet absorbers, light stabilizers, heat stabilizers Antioxidants, plasticizers, leveling agents, flow regulators, antifoaming agents, dispersants, storage stabilizers, crosslinking agents and the like. In particular, by adding inorganic fine particles or resin fine particles of a desired size, a mat hard coat layer of a desired shape can be formed. Such a hard coat layer is protected by another surface protection film, for example, by heat treatment (for example, 150 ° C., 90 minutes) or the like under the influence of the residual monomer component or the various additive components described above. There exists a tendency for pool remnants to occur more easily than the case where it stuck to water.

In particular, when the adhesiveness of the adhesive layer is high with respect to the unevenness of the mat hard coat layer, the mat hard coat layer has a large surface area with the adhesive layer in contact with the mat hard coat layer. There is a tendency for pool residues to occur more easily than layers. Moreover, when the adhesiveness of an adhesion layer is low with respect to the unevenness | corrugation of a mat hard-coat layer, since a mat hard coat layer becomes small in surface area with the contacting adhesive layer, there exists a tendency which is more likely to arise than a clear hard coat layer. However, the surface protective film of the present invention, since the adhesive layer has specific physical properties, even if the adhesive layer is attached to the mat hard coat layer, it is difficult to cause the remaining of the glue even after the heat treatment, and it is hard to cause the lifting.

In addition, even if the surface characteristic of the hard-coat layer as an example of a sticking object was a specific thing, the surface protection film of this invention can be made to remain hard even after heat processing. Specifically, as a hard coat layer, the contact angle with respect to water is adjusted smaller than a specific value, and the contact angle with camellia oil is adjusted smaller than a specific value.

For example, when fingerprints are attached to the surface of the hard coat layer, in order to make the attached fingerprints less noticeable (improvement of fingerprint visibility), water repellency and oil repellency are not strongly imparted to the coating surface. It is effective to impart proper hydrophilicity and lipophilicity. By adjusting the surface properties of the hard coat layer so that each of the contact angle with respect to water and the contact angle with camellia oil is smaller than a specific value, appropriate hydrophilicity and lipophilicity can be expressed. If proper hydrophilicity and lipophilicity can be expressed on the surface of the hard coat layer, the contact area of the fingerprint component (which becomes an aqueous component and an oily component) to the coating surface does not become too small, and the fingerprint component is appropriately applied on the coating surface. Can get wet. As a result, even when a stake is attached to the surface of the hard coat layer, the attached fingerprint can be made less noticeable (improvement of difficulty in fingerprint recognition).

In addition to the above-described adjustments, the contact angle with respect to water is adjusted to a predetermined angle or more, and the wet tension is adjusted to a predetermined range, thereby providing the function of improving the difficulty of fingerprint recognition and preventing the hard coat property from decreasing. In addition, the wiping property of the fingerprint after fingerprint attachment can be improved, and the fingerprint component after wiping can also be made less noticeable.

In this example, it is preferable that the contact angle with respect to the water of a hard-coat layer is adjusted to 110 degrees or less. More preferably, it is adjusted to 100 degrees or less. By adjusting the contact angle with respect to water to 110 degrees or less, the contact area with water does not become small too much, and it becomes difficult to make an attached fingerprint stand out (improving the difficulty of fingerprint recognition).

In this example, it is preferable that the contact angle with the camellia oil of a hard-coat layer is adjusted to 50 degrees or less. More preferably, it is adjusted to 40 degrees or less. By adjusting the contact angle with camellia oil to 50 degrees or less, the oily component in a fingerprint becomes wet and spread. For this reason, the attached fingerprint becomes hard to be outstanding (improvement of the difficulty of fingerprint recognition), and also the fingerprint component after wiping can become hard to be outstanding.

In this example, it is preferable that the contact angle with respect to the water of a hard-coat layer is adjusted to 50 degrees or more. More preferably, it is 60 degree or more, More preferably, it is 70 degree or more, Especially preferably, it adjusts to 80 degree or more. By adjusting the contact angle with respect to water 50 degree or more, the contact area with water does not become large too much. As a result, the aqueous component in a fingerprint becomes easy to isolate, and the wiping property of a fingerprint improves. That is, in this example, by adjusting the contact angle with respect to the water of a hard-coat layer to a predetermined range, in addition to the improvement of the difficulty of fingerprint recognition, the wiping property of a fingerprint can also be improved.

In addition, the value of the contact angle with respect to water and the contact angle with camellia oil are the values measured by the method based on JIS-R3257 (1999).

In this example, it is preferable that the wet tension of the hard coat layer is adjusted to 27 mN / m or more. More preferably, it is adjusted to 30 mN / m or more. Moreover, it is preferable that the wet tension of a hard-coat layer is adjusted to 45 mN / m or less. More preferably, it is 40 mN / m or less, More preferably, it is adjusted to 38 mN / m or less. By adjusting the wet tension of the hard coat layer to a predetermined range, the wiping property of the fingerprint can be enhanced.

In addition, the value of wet tension is the value measured by the method based on JIS-K6768 (1999).

The hard coat layer which has such a surface physical property can be obtained by mix | blending the compound (nonionic compound) of the HLB value by the Griffin method with a predetermined range as an addition component to the curable composition of the hard coat layer mentioned above. As such a compound, the HLB value by the Griffin method is 2 or more, Preferably it is 5 or more, More preferably, it is 10 or more, For example, 18 or less, Preferably 15 or less nonionic compound etc. Can be mentioned. By mix | blending the nonionic compound whose HLB value was adjusted suitably, it becomes easy to adjust the contact angle with respect to the water of a hard coat layer, the contact angle with camellia oil, and a wet tension to the predetermined range mentioned above.

A nonionic compound is a compound which melt | dissolves in water and does not show ionicity, but consists of the combination of a combination of a hydrophobic group (lipophilic group) and a hydrophilic group.

As such a compound, at least 1 type of hydrophilic group (for example, polyalkylene oxide, hydroxyl group, carboxyl group, sulfonyl group, phosphate, amino group, isocyanate group, glycidyl group, alkoxysilyl group, ammonium salt, various metal salts, etc.) is used. Examples of the compound having a ethoxylated glycerine triacrylate, ethoxylated bisphenol A diacrylate, polyethylene glycol diacrylate, polyether modified acrylate, polyhydroxy modified acrylate, and the like. Especially, it is preferable to use polyethyleneglycol acrylate from a viewpoint of the solubility to a solvent and handleability.

Moreover, fatty acid ester, a polyether, etc. can also be used as a nonionic compound.

Examples of the fatty acid esters include fatty acid esters by condensation of monohydric alcohols or dihydric polyhydric alcohols with fatty acids, and examples thereof include propylene glycol monostearic acid esters, propylene glycol monolauric acid esters, and diethylene glycol monostearate. Acid esters, diethylene glycol monolauric acid esters, glycerol monostearic acid esters, sorbitan sesquioleic acid esters, sorbitan monooleic acid esters, sorbitan monostearic acid esters, sorbitan monopalmitic acid esters, sorbitan monola Uric acid ester and the like. Moreover, polyoxyalkylene addition fatty acid ester is also mentioned as fatty acid ester.

Moreover, you may mix | blend the nonionic compound which carried out addition polymerization of the alkylene oxide with fatty acid ester. As the alkylene oxide to be polymerized by addition, ethylene oxide or propylene oxide is very suitable. Ethylene oxide or propylene oxide may be each independently polymerized or copolymerized.

As polyoxyalkylene addition fatty acid ester, For example, polyoxyethylene hardened castor oil, monostearic acid polyoxyethylene glycerine, polyoxyethylene (4) sorbitan monostearic acid ester, polyoxyethylene (20) sorbitan mono Stearic acid ester, polyoxyethylene (4) sorbitan tristearic acid ester, polyoxyethylene (5) sorbitan monooleic acid ester, polyoxyethylene (5) sorbitan monooleic acid ester, polyoxyethylene (20) sorbitan tree Oleic acid ester, polyoxyethylene (4) sorbitan monolauric acid ester, polyoxyethylene glycol 400 monooleic acid ester, polyoxyethylene glycol 400 monostearic acid ester, polyethylene glycol 400 monolauric acid ester, polyoxyethylene (4 ) Sorbitan monolauric acid ester, and the like.

In addition, in this example, you may use polyoxyethylene cholesteryl ether, polyoxyethylene decyl tetradecyl ether, etc. as compounds other than a fatty acid ester or a polyether.

Content of the compound whose HLB value by a griffin method is a predetermined range becomes like this. Preferably it is 0.05 weight part or more, More preferably, it is 0.1 weight part or more, More preferably, it is 1 weight part or more with respect to 100 weight part of resin components, Preferably it is 60 weight part or less, More preferably, it is 15 weight part or less, More preferably, it is 10 weight part or less. By setting the lower limit of the content of this compound to 0.1 part by weight, the contact angle with respect to water, the contact angle with camellia oil, and the wet tension of the hard coat layer can be easily adjusted to the above-mentioned predetermined ranges. Moreover, when the upper limit of content of this compound is 60 weight part, the hardness (hard coat property) of the surface of a hard-coat layer can be prevented from falling. By blending the appropriate amount, it is expected that the fingerprint wiping property of the hard coat layer is further improved.

It is preferable that the pencil scratch value of the hard coat layer is further adjusted to H or more. More preferably, it is adjusted to 2H or more. By adjusting the pencil scratch value to a predetermined value or more, it is possible to effectively prevent scratches on the surface of the hard coat layer without improving the fingerprint visibility difficulty or decreasing the fingerprint wiping property. In addition, a pencil scratch value is the value measured by the method based on JIS-K5600-5-4 (1999).

It is preferable that the value of the refractive index of the hard coat layer is further adjusted to 1.45 to 1.65. More preferably, it is adjusted to 1.46-1.52. By adjusting the value of the refractive index within a predetermined range, the difference between the refractive index of the hard coat layer and the refractive index of the fingerprint component can be reduced. As a result, when fingerprints are attached to the hard coat layer, the attached fingerprints become less noticeable (additional improvement in the difficulty of fingerprint recognition), and further, the fingerprint component after wiping may also be difficult to be noticeable.

It is preferable that the hard-coat layer is about 0.1 micrometer or more and about 30 micrometers in thickness. By making thickness of a hard-coat layer into 0.1 micrometer or more, it can be set as the film which has sufficient hardness. On the other hand, even if the thickness of the hard coat layer exceeds 30 µm, the film hardness does not further improve. In addition, when the thickness of the hard coat layer becomes thick, curling due to shrinkage of the coating tends to occur. Therefore, it is preferable to set it as thickness of 30 micrometers or less from a viewpoint of economical efficiency and a curl prevention property. In addition, in this example, it is also possible to make the thickness of a hard-coat layer into thin film about 10 micrometers or less, Furthermore, about 5 micrometers or less. Even a thin film ensures necessary performance.

In addition, in order to obtain the above-described surface characteristics, the surface of the hard coat layer may be subjected to surface treatment such as plasma treatment, corona discharge treatment, far ultraviolet irradiation treatment or the like.

Since the hard coat layer having such surface properties is more susceptible to addition components, surface treatment, and the like than the above-described hard coat layer, when the heat treatment or the like is performed, it is more likely to cause pool residue than the aforementioned hard coat layer. There is a tendency. However, the surface protective film of the present invention, since the adhesive layer has a specific physical property, even if it is adhered to a hard coat layer having such a specific surface property, it can be said that it is difficult to leave glue even after heat treatment.

The curable composition is usually realized in the form of a paint. What is necessary is just to select suitably according to the kind of resin component, when using as an organic-solvent paint, After melt | dissolving or disperse | distributing the above-mentioned resin component (additional component additionally as needed) with diluent solvents, such as an organic solvent, if necessary, By adding an additive, a curable composition can be manufactured.

 As a to-be-coated object, it is a base material to which provision of the improvement effect of hard-coat property (scratch resistance) and the difficulty of fingerprint recognition is desired. The aspect of the base material which can be used by this example is not specifically limited, What kind of thickness, such as a film form, a sheet form, or a plate form, may be sufficient. In addition, the base material may be an uneven shape, for example, or the three-dimensional shape which has a three-dimensional curved surface may be sufficient as it.

There is no restriction | limiting in particular also in the material of a base material, Although hard substrates, such as a glass plate, may be sufficient, In this example, it is preferable that it is a resin base material which has flexibility. The kind of resin which comprises a resin base material is not specifically limited. For example, acrylic, polycarbonate, polyvinyl chloride, polyester, polypropylene, polyethylene, acetyl cellulose, cycloolefin etc. are mentioned as resin in the case of forming a resin base material in a film form or a sheet form. On the other hand, for example, acrylic, polycarbonate, polyvinyl chloride, etc. are mentioned as resin in the case of forming a resin base material in plate shape.

Moreover, the easily bonding process may be performed to the base material surface in order to improve the adhesiveness with the hard-coat layer which consists of hardened | cured material of a curable composition. Examples of the easy adhesion treatment include plasma treatment, corona discharge treatment, far ultraviolet ray irradiation treatment, and formation of an undercoat easily adhesive layer.

What is necessary is just to apply | coat (coating) of the curable composition to a to-be-applied object, for example, bar coat, die coat, blade coat, spin coat, roll coat, gravure coat, flow coat, dip coat, spray Coat, screen printing, brushing, and the like. After drying and hardening mentioned later, the thickness of the coating film after application | coating is apply | coated so that it may become about 0.1 micrometer or more and about 30 micrometers or less preferably. When apply | coating curable composition to a to-be-coated object, it is preferable to dry the coating film after application | coating at about 50-120 degreeC.

Curing of a curable composition can be performed by irradiating curing by heat and / or ionizing radiation (light) with respect to the coating film after application | coating.

In the case of heat, an electric heater, an infrared lamp, a hot air etc. can be used as the heat source, for example. In the case of ionizing radiation (light), the source is not particularly limited as long as the curable composition applied to the substrate can be cured in a short time. For example, a lamp, a resistance heating plate, a laser, etc. are mentioned as an infrared ray source. As a source of visible light, daylight, a lamp, a fluorescent lamp, a laser, etc. are mentioned. As a source of ultraviolet (Ionizing radiation), an ultra high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp, etc. are mentioned. Ultraviolet rays in a wavelength range of 100 nm to 400 nm, preferably 200 nm to 400 nm emitted from such a source of ultraviolet rays are irradiated. As a source of an electron beam (ionizing radiation), a scanning type or curtain type electron beam accelerator etc. are mentioned. The electron beam of a wavelength range of 100 nm or less emitted from such an electron beam accelerator is irradiated.

Although the irradiation amount of ionizing radiation changes with kinds of ionizing radiation, about 100-500 mJ / cm <2> is preferable for light quantity, for example, in the case of an ultraviolet-ray, and about 10-1000 krad is preferable for an electron beam.

The hard coat layer manufactured as mentioned above is used for the application of the hard coat property (scratch resistance) and the improvement effect of the difficulty of fingerprint recognition, especially various displays (for example, plasma display panel PDP, CRT, liquid crystal display). LCD, electro luminescence display ELD, etc.); For showcases, watches or glass cover; For touch surfaces of electronic devices of the touch panel type represented by ATMs and ticket vending machines of banks; It is used suitably as a hard coat of these.

In addition, the electronic devices include, of course, information processing apparatuses such as mobile phones having the various displays (including personal digital assistants including PDAs) and personal computers. .

Example

Hereinafter, the present invention will be further described by way of examples. In addition, "part" and "%" are taken as a basis of weight unless there is particular notice.

[Examples 1-3 and Comparative Examples 1-4]

As a base material, the coating liquid for adhesion layers (Examples 1-3, Comparative Examples 1-4) of the prescription of Table 1 was applied to one side of the 25-micrometer-thick polyethylene terephthalate film (Lumera S28: Toray Corporation). It applied, respectively, and it dried at 90 degreeC for 1.5 minute, formed the adhesion layer of 2.5 micrometers of dry film thickness, and bonded together with a separator (MRF: Mitsubishi Kagaku polyester film company) in order to improve handleability. Subsequently, 48 hours of curing was performed in 60 degreeC environment, and the surface protection films of Examples 1-4 and Comparative Examples 1-4 were produced.

About the adhesion layer obtained by the Example and comparative example of Table 1, it measured about (1) 150 degreeC, storage elastic modulus of 20 degreeC, tan-delta maximum temperature, and tan-delta in 100 degreeC-150 degreeC. Moreover, about the surface protection film obtained by the Example and the comparative example, evaluation was performed about (2) initial stage adhesive force, (3) adhesive force after heating, (4) glue remaining, and (5) lifting. The results are shown in Table 2.

(1) Storage modulus at 150 ° C, 20 ° C, tanδ maximum temperature, tanδ at 100 ° C to 150 ° C

The adhesive, the hardening | curing agent, and the solvent of the prescription of Table 1 were mixed after predetermined amount weighing, and it fully stirred. It moved to another container so that the coating film thickness after drying might be about 1 mm, and drying and curing were performed at 40 degreeC for 4 days. Then, only the coating film was taken out from the container, and the measurement sample was produced.

By measuring the dynamic viscoelasticity of the measurement sample using a viscoelasticity measuring device (Physica MCR301: Anton Paar), the storage modulus at 150 ° C and 20 ° C, the maximum temperature at tanδ, and tanδ at 100 ° C to 150 ° C were determined. . Measurement conditions were 0.1% strain, frequency 1 Hz, and the temperature range -30 degreeC-160 degreeC.

(2) initial adhesion

The test piece was produced by cutting the surface protection film of an Example and a comparative example into the magnitude | size of width 50mm x length about 200mm so that a longitudinal direction might become a coating direction. Subsequently, after attaching a test piece to a stainless steel plate (SUS304 steel plate prescribed | regulated to JIS G4305), and leaving it to stand at 23 degreeC and 50% RH environment for 1 hour, according to JIS ZO237: 2000, a tensilone universal tensile tester (tensilon HTM) -100: Orientec Co., Ltd.), 180-degree peel adhesion was measured.

(3) adhesive force after heating

In the same manner as in (2), a test piece was prepared, affixed to a stainless steel plate, left for 30 minutes in an environment of 23 ° C and 50% RH, and then left in an environment of 150 ° C for 30 minutes, and further subjected to 23 ° C and 50% RH. After leaving for 30 minutes in the environment, it carried out similarly to (2), and measured 180 degree peel adhesive force.

(4) pool left

After measuring the adhesive force after the heating of (3), the remainder of the paste was evaluated by visually observing the state of the stainless steel plate. Evaluation showed that there was no glue remaining in the stainless steel plate at all, and that "○" and a part of the stainless steel plate had glue remaining, "(triangle | delta)" causes cohesive failure between a stainless steel plate and a base material, and a glue remains on almost the entire surface of the stainless steel plate. What was discarded was made into "x".

(5) lifting

In the measurement of the adhesive force after heating of (3), after leaving the stainless steel plate which affixed the test piece for 30 minutes in 150 degreeC environment, and leaving for 30 minutes in 23 degreeC and 50% RH environment, it lifts from a stainless steel plate. It was visually evaluated whether this occurred. "○" that the test piece is bonded to the stainless steel plate and no lifting occurs at all, and the area where the test piece is in close contact with the stainless steel plate is larger than the area where the test piece is peeled off, and the area where the test piece is peeled off from the stainless steel plate is in close contact. The one larger than the area was made into "x".

From Table 2, in the surface protection film of the Example, the difference between the storage modulus at 150 ° C. and the storage modulus at 20 ° C. of the adhesive layer is greater than 0, satisfies Equation 1 above, and tanδ maximum temperature is −5. ℃ or less. For this reason, it was excellent in initial stage adhesiveness, there was little increase of adhesive force even after 150 degreeC and the heat processing for 30 minutes, and there was no glue left to the surface at the time of peeling from a stainless steel plate, and it became hard to generate | occur | produce. Moreover, since adhesiveness (180 degree peeling adhesive force in JIS Z0237: 2000) after heating was 0.1 N / 50 mm-1 N / 50 mm, peelability was favorable.

In the surface protective films of Comparative Examples 1 and 2, the tanδ maximum temperature of the adhesive layer was -5 ° C or lower, but tanδ at 100 ° C to 150 ° C was greater than 0.1, and the storage modulus at 150 ° C and 20 ° C Since the difference in storage elastic modulus in the case was smaller than 0 and did not satisfy the above formula (1), no floating occurred, but the initial adhesiveness was high, and the adhesive force increased even after the heat treatment at 150 ° C. for 30 minutes, resulting from the stainless plate. It became what remained of a paste on the surface at the time of peeling. Moreover, since it was adhesive force (180 degree peeling adhesive force in JIS Z0237: 2000) after heating, and 1 N / 50 mm or more, peelability became bad.

In the surface protection film of Comparative Example 3, the difference between the storage modulus at 150 ° C. and the storage modulus at 20 ° C. was smaller than 0, but the tanδ maximum temperature of the adhesive layer was higher than −5 ° C., so that the surface protective film was lifted. For this reason, there was no pool remaining.

In the surface protective film of Comparative Example 4, since the tanδ maximum temperature of the pressure-sensitive adhesive layer was -5 ° C or lower, and the tanδ at 100 ° C to 150 ° C was 0.1 or lower, no lifting occurred, and the initial adhesiveness did not become too high. Good results have been obtained. However, since the difference between the storage modulus at 150 ° C. and the storage modulus at 20 ° C. was smaller than 0 and did not satisfy the above formula (1), the adhesive force after the heat treatment increased, and at the time of peeling from the stainless plate The grass remained on the surface.

Example 4

A hard coat film (KB film GN7B: Kimoto Co., Ltd.) having a clear hard coat layer of an ionizing radiation curable resin on one side of the substrate and a mat hard coat layer of silica fine particles and an ionizing radiation curable resin on the other side were prepared. . Next, the surface which has the adhesion layer of the surface protection film of Example 1 was stuck on the clear hard coat layer of the prepared hard coat film, and the laminated body of Example 4 was produced. In addition, the clear hard coat layer had a contact angle with water of 62 degrees, a contact angle with camellia oil of 31 degrees, and a wet tension of 23 mN / m or less.

Example 5

On the mat hard coat layer of the hard coat film of Example 4, the surface which has the adhesion layer of the surface protection film of Example 1 was stuck, and the laminated body of Example 5 was produced. In addition, the matte hard coat layer has a contact angle of water of 79 degrees, a contact angle of camellia oil of 34 degrees, a wet tension of 23 mN / m or less, and an arithmetic mean roughness of JIS B0601: 2001 of 0.12 ± 0.04 μm. It was.

Example 6

On one side of the substrate, a hard coat film (KB film AFP: Kimoto Co., Ltd.) having a hard coat layer having a contact angle of water of 76 degrees, a contact angle of camellia oil of 36 degrees, and a wet tension of 32 mN / m was prepared. . Next, the surface which has the adhesion layer of the surface protection film of Example 1 was stuck on the hard-coat layer of the prepared hard coat film, and the laminated body of Example 6 was produced.

[Comparative Examples 5-7]

The laminated body of Comparative Examples 5-7 was carried out similarly to Examples 4-6 except having changed into the surface protective film of Comparative Example 4 instead of the surface protective film of Example 1 with the laminated body of Examples 4-6. Was produced.

About the lamination | stacking agent obtained in Examples 4-6 and Comparative Examples 5-7, (6) initial stage adhesive force, (7) adhesive force after heating, and (8) paste remainder when peeling surface protection film from a hard-coat layer , (9) The evaluation was carried out. The results are shown in Table 3.

(6) initial adhesion

About the laminated body obtained in Examples 4-6 and Comparative Examples 5-7, it cuts into the magnitude | size of width 50mm x length about 200mm, produces a test piece, and is left to stand in 23 degreeC and 50% RH environment for 1 hour, According to JIS Z0237: 2000, the surface protection film was peeled from the hard-coat layer using the tensilon universal tensile tester (Tensilon HTM-100: Orientec Co., Ltd.), and 180 degree peeling adhesive force was measured.

(7) adhesive force after heating

A test piece was prepared in the same manner as in (6), left for 30 minutes in an environment of 23 ° C. and 50% RH, and then left for 30 minutes in an environment of 150 ° C., and further left for 30 minutes in an environment of 23 ° C. and 50% RH. Then, 180 degree peel adhesive force was measured similarly to (6).

(8) pool left

About the laminated bodies of Examples 4-6 and Comparative Examples 5-7, it cut | disconnected to the magnitude | size of A-4, produced a test piece, and left it for 30 minutes in 23 degreeC and 50% RH environment, and then 90 degreeC in 150 degreeC environments. It was left to stand for an additional 30 minutes in an environment of 23 ° C. and 50% RH, and then the surface protective film was peeled off from the hard coat layer by hand. Evaluation was observed with the naked eye, and it was hard to know that "×" which left the remainder on the whole surface on the hard-coat layer, and "X" that left the left | surface remained in various places on the hard coat layer, but the loupe (25) (X25 times), and there is a fine paste residue (dot of about 10 占 퐉 x 20 占 퐉) on the hard coat layer with "△", and there is almost no point paste. It was set as.

(9) lifting

In the measurement of the adhesive force after heating in (7), when the test piece was left for 30 minutes in an environment of 150 ° C. and then left for 30 minutes in an environment of 50% RH at 23 ° C., whether or not lifting occurred from the hard coat layer. Was evaluated visually. “○” indicates that the test piece and the hard coat layer were bonded together, and no lifting occurred. The area where the test piece was in close contact with the hard coat layer was larger than the peeled area. And larger than the area in close contact with each other were "x".

From Table 3, all the laminated bodies of the Example were excellent in initial stage adhesiveness with respect to a hard-coat layer, there was little increase of adhesive force even after heat processing of 150 degreeC and 30 minutes, and it became the thing which arose no lifting.

In addition, in the laminates of Examples 4 and 5, when the surface protective film was peeled off from the hard coat layer after heat treatment at 150 ° C. for 90 minutes, the hard coat layer was not visible to the naked eye. There was little fine grass remaining.

In addition, since the hard coat layer was a specific physical property, when the laminated body of Example 6 peeled off the surface protection film from the hard coat layer after 150 degreeC and 90-minute heat processing, the laminated body of Examples 4 and 5 was carried out. In comparison with the hard coat layer of, the evaluation of the remaining of the pool was decreased, but the remaining of the pool was not seen by the naked eye, and it became a degree which can confirm the fine pool remaining by the loupe.

On the other hand, in the laminate of the comparative example, since the tanδ maximum temperature of the pressure-sensitive adhesive layer was -5 ° C or less, and tanδ at 100 ° C to 150 ° C was 0.1 or less, no lifting occurred and the initial adhesiveness was not too high. The result was obtained. However, since the difference of the storage modulus in 150 degreeC and the storage modulus in 20 degreeC was less than 0, and the adhesion layer of a surface protection film did not satisfy said Formula (1), lamination of Comparative Examples 5 and 6 When the sieve peeled off the surface protective film from the hard coat layer after 150 degreeC and 90-minute heat processing, the remainder of the paste which became clear to the naked eye became various places on the hard coat layer.

In addition, since the hard coat layer was of specific physical properties, the laminate of Comparative Example 7 was clearly identified by the naked eye when peeling the surface protective film from the hard coat layer after heat treatment at 150 ° C. for 90 minutes. Remaining became what happened in the whole surface on a hard-coat layer.

Thus, the surface protection film used for the laminated body of an Example compares with the surface protection film used for the laminated body of a comparative example, even if a to-be-protected object is various hard-coat layers, moderate initial stage adhesiveness and the adhesive force after heat processing raise it. It has shown very good performances such as the suppression of anti-freeze, anti-lift property, and anti-remaining property of pool.

Claims (6)

A surface protective film having a pressure-sensitive adhesive layer on one side of a substrate, wherein the pressure difference between the storage modulus at 150 ° C. and the storage modulus at 20 ° C. satisfies Equation 1, and the tanδ maximum temperature is −5 ° C. FIG. Surface protection film characterized in that the following.
[Equation 1]

[In formula, G '(150) is a storage modulus in 150 degreeC, G' (20) is a storage modulus in 20 degreeC. Tan δ is a value obtained by dividing the loss modulus by the storage modulus.] The surface protective film according to claim 1, wherein the adhesive layer has a tan δ of 0.1 or less at 100 ° C. to 150 ° C. The surface protection film of Claim 1 or 2 WHEREIN: The surface which has the adhesion layer of the said surface protection film, and the stainless steel plate (SUS304 steel plate prescribed | regulated to JIS G4305) are bonded together, and it is carried out to the environment of 150 degreeC in 30 degreeC. After leaving for a minute, the adhesive force (180 degree peel adhesive force in JIS Z0237: 2000) of the surface protection film to the stainless steel plate is 0.1 N / 50 mm-1 N / 50 mm, The surface protection film characterized by the above-mentioned. The surface which has the adhesion layer of the surface protection film in any one of Claims 1-3 is stuck on the hard-coat layer, The laminated body characterized by the above-mentioned. The method of claim 4, wherein
The hard coat layer has a contact angle with water of 110 degrees or less and a contact angle with camellia oil of 50 degrees or less. The method of claim 5,
The hard coat layer is a laminate, characterized in that the contact angle to water is 50 degrees or more, and the wet tension is 27 ~ 45 mN / m.