JP2016040343A - Surface protective film, and hard coat film with surface protective film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface protective film without reducing finger slipperiness of a hard coat film having such finger slipperiness, and the hard coat film with the surface protective film.SOLUTION: There is provided a surface protective film for protecting a hard coat film. The surface protective film is obtained by forming an adhesive layer on one surface of a substrate. In the surface protective film, a friction force of the hard coat film after peeling the surface protective film therefrom is 0.8 to 1.5 times of the friction force of the hard coat film before adhering the surface protective film.SELECTED DRAWING: None

Description

  The present invention relates to a surface protective film for protecting a hard coat film having finger slip on the surface, and even if the surface protective film is attached to the hard coat film and then peeled off, the slip property of the hard coat film It is related with the surface protection film which does not inhibit this, and the hard coat film with the said surface protection film.

  In recent years, various functional films such as optical films and hard coat films, mobile phones, smartphones, PNDs, tablet PCs, slate PCs, and other electronic devices are manufactured, transported and stored. In order to prevent scratches on the surface of electronic equipment, adhesion of dirt, contamination, etc., a surface protective film with an adhesive layer on one side of the transparent resin film is applied to the surface of the panel functional film or electronic equipment. Temporary protection is generally done.

  In particular, regarding hard coat films, there is an increasing demand for hard coat films to which not only hard coat properties but also high functions such as fingerprint resistance and finger slip properties are added (Patent Document 1).

JP 2007-264281 A

  As an example of high functionality, when a hard coat film having finger slipperiness is shipped, a surface protective film is temporarily bonded to prevent the surface from being scratched. When peeled off, the function of finger slipping may be reduced.

  An object of this invention is to provide the surface protection film which does not reduce the finger slip property with which a hard coat film is provided, the hard coat film provided with the said surface protection film, and its manufacturing method.

  In order to solve such a problem, the present inventor uses a specific pressure-sensitive adhesive in the pressure-sensitive adhesive layer of the surface protective film, so that even if the film is applied for surface protection of a hard coat film having finger slipperiness, The present inventors have found that it is possible to prevent the slipperiness from being lowered, and have reached the present invention.

  That is, the surface protective film of the present invention is a surface protective film for protecting the hard coat film, and the surface protective film is formed by forming an adhesive layer on one surface of the base material. A protective film is stuck on a hard coat film, and the friction force of the hard coat film after peeling is within 0.8 to 1.5 times the friction force before sticking the surface protective film of the hard coat film. It is a feature.

  Further, the surface protective film of the present invention is for protecting the hard coat film, the hard coat film is provided with finger slipperiness, and the surface protective film is provided on one surface of the substrate. An adhesive layer is formed, and the adhesive layer of the surface protective film includes a two-component curable urethane-based adhesive composed of (a) a polyol and (b) an isocyanate-based curing agent.

  In the surface protective film of the present invention, the ratio of (b) isocyanate curing agent to (a) polyol in the adhesive layer is preferably (b) isocyanate curing agent based on 100 parts by weight of polyol. Is 10 to 25 parts by weight.

  In the hard coat film with a surface protective film of the present invention, the hard coat film is provided with finger slipperiness, and the surface protective film has (a) polyol and (b) isocyanate on one surface of the substrate. It is characterized in that an adhesive layer containing a two-component curable urethane-based adhesive composed of a system curing agent is formed.

  According to the surface protective film for protecting the hard coat film of the present invention, even if it is used for protecting the hard coat film having a finger slippery function, the hard coat film at the time of peeling of the surface protective film The finger slipperiness can be maintained. Moreover, even if it peels off a surface protective film at the time of use, the said hard coat film with a surface protective film will exhibit the finger-slip property of a hard coat film favorably.

FIG. 1 is a schematic diagram showing one method for evaluating slipperiness.

  Hereinafter, embodiments of the surface protective film and the hard coat film with the surface protective film of the present invention will be described.

  The surface protective film of the present invention is a surface protective film for protecting a hard coat film, and the surface protective film is formed by forming an adhesive layer on one surface of a substrate. In addition, the surface protective film has a frictional force due to the synthetic leather of the hard coat film after the surface protective film is adhered and peeled, and the frictional force before the surface protective film of the hard coat film is adhered is 0.8 to 1. It is preferable that it is within 5 times because the feeling of use does not change before and after the surface protective film is attached. More preferably, it is within 0.9 to 1.2 times.

  The frictional force by synthetic leather in the present application means that the hard coat film is fixed on the glass plate with the surface (hard coat layer surface) on which the frictional force is to be measured facing up, and synthetic leather, glass (6. 5 cm × 6.5 cm) and a weight (load 1 kg) in this order, and then the eyeball clip 25 was attached to the other end of the synthetic leather, and the hook of the spring balance 26 was hooked into the hole of the eyeball clip 25. Next, it is a value obtained by measuring the load when the spring scale 26 is pulled and the synthetic leather 22 starts moving on the hard coat layer. The smaller the frictional force (the force at which the synthetic leather starts to move), the better the finger slipping.

  The frictional force due to the synthetic leather of the hard coat film is preferably 2.5 to 6.0 N both before and after the surface protective film is attached and peeled off.

<Surface protection film>
The surface protective film of the present invention has an adhesive layer formed on one surface of a substrate. Although it does not specifically limit as a base material, A thing with high optical transparency is preferable. Examples thereof include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethylene, polypropylene, polystyrene, triacetyl cellulose, acrylic, polyvinyl chloride, and norbornene compounds. In particular, a biaxially stretched polyethylene terephthalate film is preferably used because of its excellent mechanical strength and dimensional stability. Moreover, you may use what performed easy adhesion processes, such as formation of a plasma process, a corona discharge process, a far-ultraviolet irradiation process, and formation of an undercoat easily bonding layer, to the said transparent resin film.

  Although the thickness of a base material is not specifically limited, When handling property, mechanical strength, etc. are considered, 10-500 micrometers is preferable and it is more preferable to set it as 25-300 micrometers.

  Next, the pressure-sensitive adhesive layer contains a two-component curable urethane pressure-sensitive adhesive composed of (a) a polyol and (b) an isocyanate-based curing agent. The pressure-sensitive adhesive layer is capable of being attached to the hard coat film having finger slipping property of the present invention, and fulfills a function of facilitating peeling after application.

  Examples of the polyol (a) include polyether polyol, polyester polyol, polyether polyol and / or polyurethane polyol which is a reaction product of polyester polyol and polyisocyanate, polyether adduct of polyhydric alcohol, and the like. In addition, as a polyether polyol, what has each repeating structure of alkylene oxide chains, such as a methylene oxide chain, an ethylene oxide chain, a propylene oxide chain, a butylene oxide chain, or two or more types can be used.

  (B) The isocyanate curing agent may be any polyfunctional compound having two or more isocyanate groups, such as diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, phenylene diisocyanate, 1 , 5-naphthylene diisocyanate, xylylene diisocyanate, toluylene diisocyanate, and the like; and aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate.

  Even if the adhesive layer is affixed to a hard coat film having finger slipperiness by using a two-component curable urethane-based adhesive composed of (a) polyol and (b) isocyanate-based curing agent in this way Even after the adhesive layer is peeled off, the finger slipperiness of the hard coat film is continuously exhibited without inhibiting the finger slipperiness of the hard coat film surface. In addition, by using the pressure-sensitive adhesive layer containing the urethane-based pressure-sensitive adhesive, bubbles are prevented from being mixed when affixed to the hard coat film, and further, due to the pressure-sensitive adhesive layer when peeling the surface protective film. Demonstrates the effect of preventing adhesive residue.

  Although the content ratio of (a) polyol and (b) isocyanate curing agent depends on the NCO group value of the isocyanate curing agent, etc., it cannot be said unconditionally, but (a) with respect to 100 parts by weight of polyol. (B) It is preferable to contain 10-25 weight part of isocyanate type hardening | curing agents. The above-mentioned content ratio is more preferably 12 parts by weight or more as a lower limit. Further, the upper limit is more preferably 20 parts by weight or less.

  Moreover, it is preferable that content of the NCO group in the isocyanate type hardening | curing agent mentioned above is 5 to 20% in the case of 75% of solid content.

  As long as the effect of the present invention is not hindered, the pressure-sensitive adhesive layer includes powders such as colorants, pigments, surfactants, plasticizers, tackifiers, low molecular weight polymers, surface lubricants, leveling agents, antioxidants, Corrosion inhibitors, light stabilizers, UV absorbers, polymerization inhibitors, silane coupling agents, inorganic or organic fillers, metal powders, particles, foils, etc., depending on the application used It may be included.

  The thickness of the adhesive layer is preferably 1-30 μm.

<Hard coat film>
Next, the hard coat film of the present invention is composed of at least a hard coat layer, and may be composed of, for example, a single hard coat layer or a laminated structure in which a hard coat layer is formed on a substrate. It may be.

  The thickness of the hard coat layer is not particularly limited, but is preferably 1 μm or more from the viewpoint of scratch resistance, and is preferably 50 μm or less from the viewpoint of preventing cracks and curling.

  From the viewpoint of preventing scratches, the hard coat layer preferably has a pencil hardness of JIS-K5400: 1990 of H or higher, more preferably 2H or higher, and even more preferably 3H or higher.

  The hard coat layer of the present invention is formed by curing a curable composition containing at least a coating material and a curable resin.

  The coating material is preferably composed of at least a reaction product of Compound A, Compound B, Compound C, and Compound D. In the present invention, compound A is an acrylic polymer having a hydroxyl group in the side chain, compound B is a diisocyanate, compound C is a polyether polyol, and compound D is a photopolymerizable compound having both a hydroxyl group and a photopolymerizable group. By using such a coating agent, finger slipping properties are exhibited, and at the same time, anti-fingerprint properties are also exhibited.

  Compound A (acrylic polymer having a hydroxyl group in the side chain) is composed of a polymer of a monomer composition. The monomer composition of this example contains (meth) acrylic acid alkyl ester as a main component, and further contains a hydroxyl group-containing vinyl monomer copolymerizable with (meth) acrylic acid alkyl ester.

  In addition, compound A will mainly contribute to the slidability of the hard coat film, but by using an adhesive layer composed of a two-component curable urethane-based adhesive as a surface protective film as in the present invention, Even if the surface protective film is attached to the hard coat film, the finger slip property of the hard coat film after the surface protective film is peeled is maintained without inhibiting the finger slip function.

Examples of (meth) acrylic acid alkyl esters include methacrylic acid alkyl esters and / or acrylic acid alkyl esters, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth ) Butyl acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic acid Nonyl, decyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentadienyl (meth) acrylate and the like can be mentioned. These alkyl (meth) acrylates can be used alone or in combination of two or more.
(Meth) acrylic acid alkyl ester is preferably methyl (meth) acrylate or butyl (meth) acrylate, more preferably methyl (meth) acrylate, particularly preferably methyl methacrylate (MMA). Is mentioned.

  The blending ratio of the (meth) acrylic acid alkyl ester is, for example, 40% by mass or more, preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass with respect to the total amount of the monomer composition. That is usually less than 100% by mass.

  If the blending ratio of alkyl (meth) acrylate (especially methyl (meth) acrylate) is in the above range, the glass transition temperature of compound A can be set high, and the coating surface obtained using the coating material Excellent finger slipperiness can be ensured.

The hydroxyl group-containing vinyl monomer is a (meth) acrylic acid alkyl ester containing a hydroxyl group, and specifically includes, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth ) 3-hydroxypropyl acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, (meta ) Acrylic acid 10-hydroxydecyl, (meth) acrylic acid 12-hydroxylauryl, (meth) acrylic acid 4-hydroxymethylcyclohexyl, (meth) acrylic acid N-hydroxymethylamide, and the like. These hydroxyl group-containing vinyl monomers can be used alone or in combination of two or more.
As the hydroxyl group-containing vinyl monomer, 2-hydroxyethyl (meth) acrylate is preferable, and 2-hydroxyethyl acrylate (2-HEA) is more preferable.

  The mixing ratio of the hydroxyl group-containing vinyl monomer is, for example, 50% by mass or less, preferably 40% by mass or less, and usually 5% by mass or more, based on the total amount of the monomer composition.

The monomer composition of the present invention can further contain a copolymerizable vinyl monomer copolymerizable with a (meth) acrylic acid alkyl ester and / or a hydroxyl group-containing vinyl monomer.
Examples of the copolymerizable vinyl monomer include an epoxy group-containing vinyl monomer, an amide group-containing vinyl monomer, a cyano group-containing vinyl monomer, an imide group-containing vinyl monomer, a carboxyl group-containing vinyl monomer, and an alkoxypolyalkylene glycol group-containing vinyl monomer. Examples thereof include functional group-containing vinyl monomers (excluding hydroxyl group-containing vinyl monomers). That is, a copolymer containing at least one functional group selected from a predetermined functional group group (for example, an epoxy group, an amide group, a cyano group, an imide group, a carboxyl group, an alkoxypolyalkylene glycol group, etc.) and no hydroxyl group Include vinyl monomers.

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

  Examples of the amide group-containing vinyl monomer include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and N-butyl (meth) acrylamide. N-methoxymethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-vinylcarboxylic acid amide, dimethylaminopropyl acrylamide, diacetone acrylamide, N-methylol acrylamide and the like. It is done. Among these, N, N-dialkyl (meth) acrylamide such as N, N-dimethyl (meth) acrylamide is preferable, and N, N-dimethylacrylamide (DMAA) is more preferable.

Examples of the cyano group-containing vinyl monomer include acrylonitrile and methacrylonitrile.
Examples of the imide group-containing vinyl monomer include maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; for example, N-methylitaconimide, N-ethylitaconimide, N -Itaconic imide monomers such as butyl itaconimide, N-octyl itaconimide, N-2-ethylhexylitaconimide, N-cyclohexyl itaconimide, N-lauryl itaconimide; N- (meth) acryloyloxymethylene succinimide, N- Examples thereof include succinimide monomers such as (meth) acryloyl-6-oxyhexamethylene succinimide and N- (meth) acryloyl-8-oxyoctamethylene succinimide.

  Examples of the carboxy group-containing vinyl monomer include unsaturated carboxylic acids such as (meth) acrylic acid, fumaric acid, maleic acid, itaconic acid, crotonic acid and cinnamic acid; for example, fumaric anhydride, maleic anhydride, itaconic anhydride Unsaturated dicarboxylic acid anhydrides such as acids; for example, unsaturated dicarboxylic acid monoesters such as monomethyl itaconate, monobutyl itaconate, 2-acryloyloxyethylphthalic acid; for example, 2-methacryloyloxyethyl trimellitic acid, 2-methacryloyl Unsaturated tricarboxylic acid monoesters such as oxyethyl pyromellitic acid; for example, carboxyalkyl acrylates such as carboxyethyl acrylate and carboxypentyl acrylate;

  Examples of the alkoxypolyalkylene glycol group-containing vinyl monomer include methoxypolyethylene glycol (meth) acrylate.

  Further, examples of the copolymerizable vinyl monomer further include a polyfunctional monomer having a plurality of functional groups capable of radical polymerization.

  Examples of the polyfunctional monomer include (mono or poly) ethylene glycol di (meth) acrylate such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol di (meth) acrylate. (Mono or poly) alkylene glycol di (meth) acrylate such as (meth) acrylate and propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate , Pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tetramethylol methanetri (meth) acrylate DOO, dipentaerythritol hexa (meth) acrylate, and divinylbenzene.

  In addition to the copolymerizable vinyl monomer, examples of the copolymerizable vinyl monomer include vinyl esters such as vinyl acetate and vinyl propionate; for example, olefin monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene. For example, (meth) acrylic acid aryl esters such as phenyl (meth) acrylate; for example, aromatic vinyls such as styrene and vinyltoluene; for example, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, etc. For example, vinyl ether monomers such as vinyl ether; halogen atom-containing monomers such as vinyl chloride; for example, N-vinylpyrrolidone, N- (1-methylvinyl) pyrrolidone, N-vinylpyridine N-vinyl piperidone, N-vinyl pyrimidine, N-vinyl piperazine, N-vinyl pyrazine, N-vinyl pyrrole, N-vinyl imidazole, N-vinyl oxazole, N-vinyl morpholine, tetrahydrofurfuryl (meth) acrylate, (meta ) A vinyl group-containing heterocyclic compound such as acryloylmorpholine; for example, an acrylate monomer containing a halogen atom such as a fluorine atom;

The copolymerizable vinyl monomer is preferably a functional group-containing vinyl monomer, more preferably an amide group-containing vinyl monomer. These copolymerizable vinyl monomers can be used alone or in combination.
When a copolymerizable vinyl monomer is used, the blending ratio is, for example, 10 to 50% by mass, preferably 20 to 40% by mass, based on the total amount of the monomer composition.

  Compound A can be obtained by polymerizing the monomer composition described above. Examples of the polymerization method include emulsion polymerization (including suspension polymerization), solution polymerization, bulk polymerization, and the like, and preferably emulsion polymerization and solution polymerization.

  In emulsion polymerization, for example, a polymerization initiator, an emulsifier, and, if necessary, a chain transfer agent are blended and polymerized in water together with the monomer composition described above. More specifically, for example, known emulsion polymerization methods such as a batch charging method (batch polymerization method) and a split charging method (multistage polymerization method) can be employed. In addition, reaction conditions etc. are selected suitably.

  The polymerization initiator is not particularly limited, and a polymerization initiator usually used for emulsion polymerization is used. For example, organic peroxides such as benzoyl peroxide, lauroyl peroxide, caproyl peroxide, t-hexyl peroxyneodecanate, t-butyl peroxybivalate; for example, 2,2-azobis-iso-butyronitrile, 2,2-azobis-2,4-dimethylvaleronitrile, 2,2-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobis-2-methylbutyronitrile (ABN-E, manufactured by Nippon Hydrazine Kogyo Co., Ltd.) ) And the like; These polymerization initiators can be used alone or in combination of two or more. Of these polymerization initiators, an azo compound is preferable. The blending ratio of the polymerization initiator is appropriately selected and is, for example, 0.01 to 5 parts by mass with respect to 100 parts by mass of the monomer composition.

  The emulsifier is not particularly limited, and known emulsifiers commonly used for emulsion polymerization (for example, anionic emulsifiers, nonionic emulsifiers, etc.) are used. The blending ratio of the emulsifier is, for example, 0.1 to 5 parts by mass with respect to 100 parts by mass of the monomer composition.

  The chain transfer agent is blended as necessary, and adjusts the molecular weight of Compound A. Examples thereof include mercapters such as 1-dodecanethiol. These chain transfer agents can be used alone or in combination, and the blending ratio thereof is, for example, 0.1 to 1 part by mass with respect to 100 parts by mass of the monomer composition.

  Compound A obtained by emulsion polymerization is prepared as an emulsion (water dispersion type), that is, an aqueous dispersion of compound A. The solid content (nonvolatile content) concentration in the aqueous dispersion of Compound A is, for example, 5 to 50% by mass.

  In solution polymerization, together with the above-described monomer composition, the above-described polymerization initiator and, if necessary, a chain transfer agent are blended and polymerized in an organic solvent.

  The organic solvent only needs to dissolve the monomer composition described above. For example, ketone organic solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ester organic solvents such as methyl acetate, ethyl acetate and butyl acetate; dimethylformamide Polar solvents such as dimethyl sulfoxide, N-methyl-2-pyrrolidone; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol; aromatics such as toluene, xylene, “Solvesso 100” (manufactured by ExxonMobil Chemical) Hydrocarbon organic solvents: n-hexane, cyclohexane, methylcyclohexane, “Loose” (manufactured by Shell Chemicals), “Mineral Spirit EC” (manufactured by Shell Chemicals), and other aliphatic hydrocarbons / alicyclic hydrocarbons Organic Solvents; cellosolve organic solvents such as methyl cellosolve, ethyl cellosolve and butyl cellosolve; ether organic solvents such as tetrahydrofuran and dioxane; carbitol organic solvents such as n-butyl carbitol and iso-amyl carbitol; These organic solvents can be used alone or in combination of two or more. The mixing ratio of the organic solvent is appropriately set depending on the purpose and application.

In solution polymerization, the monomer composition described above is polymerized in an organic solvent in the presence of a polymerization initiator, for example, at 30 to 150 ° C. for 3 to 12 hours.
Compound A obtained by solution polymerization is prepared as an organic solvent solution (solution type), that is, an organic solvent solution of Compound A. The solid content concentration in the organic solvent solution of Compound A is, for example, 5 to 50% by mass, and preferably 10 to 40% by mass.

  The weight average molecular weight (Mw) of Compound A is, for example, 5000 to 150,000, preferably 10,000 to 120,000. Moreover, the number average molecular weight (Mn) of the obtained compound A is 1000-50000, for example, Preferably it is 5000-50000.

  In addition, the values of Mw and Mn are obtained by measuring the molecular weight distribution of Compound A using a gel permeation chromatograph (GPC) equipped with a differential refractive index detector (RID), for example, and the resulting chromatogram (chart). From this, standard polystyrene can be calculated as a calibration curve (the same applies hereinafter).

  The glass transition temperature (Tg) calculated | required by the Fox formula of the compound A is 23 degreeC or more, for example, Preferably it is 30 degreeC or more, More preferably, it is 45 degreeC or more, and is 120 degrees C or less normally. When the glass transition temperature of Compound A is at least the above lower limit, excellent finger slipping properties can be secured on the coating surface obtained using the coating material.

  When preparing the compound A as a solution, the viscosity (25 degreeC) is 2-200 mPa * s, for example, Preferably it is 5-150 mPa * s. The viscosity is measured using a cone / plate viscometer (JIS K 5600-2-3: 1999), “Paint General Test Method—Part 2: Properties and Stability of Paint—Section 3: Viscosity (Cone / Plate Viscometer Method) ”(hereinafter the same shall apply).

  Hydroxyl value of Compound A (JIS K 1557-1: 2007 (ISO 14900: 2001), “Plastics—Polyurethane raw material polyol test method—Part 1: Method of obtaining hydroxyl value”) For example, it is 5-70 mgKOH / g, Preferably it is 10-50 mgKOH / g, More preferably, it is 10-45 mgKOH / g. If the hydroxyl value of the compound A is in the above range, excellent hardness can be secured on the coating surface obtained by using the coating material, and finger slipping can be improved.

Examples of the compound B (diisocyanate) include aromatic diisocyanate (for example, tolylene diisocyanate (2,4- or 2,6-tolylene diisocyanate or a mixture thereof), phenylene diisocyanate (m-, p-phenylene diisocyanate or a mixture thereof). ), 1,5-naphthalene diisocyanate, diphenylmethane diisocyanate (4,4′-, 2,4′- or 2,2′-diphenylmethane diisocyanate or mixtures thereof), 4,4′-toluidine diisocyanate, etc.); Araliphatic diisocyanates (eg, xylylene diisocyanate (1,3- or 1,4-xylylene diisocyanate or mixtures thereof), tetramethyl xylylene diisocyanate (1,3- or 1,4-tetramethyl xylene) ), Aliphatic diisocyanates (eg, 1,3-trimethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate); Cyclic diisocyanates (eg, cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorodiisocyanate), methylene bis (cyclohexyl isocyanate), norbornane diisocyanate, bis (isocyanatomethyl) cyclohexane, etc .; Can be mentioned. These compounds B can be used alone or in combination of two or more.
The compound B is preferably an aliphatic diisocyanate or an alicyclic diisocyanate from the viewpoints of light resistance and yellowing resistance.

Compound C (polyether polyol) is, for example, ethylene oxide with a low molecular weight polyol (for example, ethylene glycol, propylene glycol, glycerin, etc.) or an aromatic / aliphatic polyamine (for example, ethylenediamine, tolylenediamine, etc.) as an initiator. And / or an addition reaction of alkylene oxide such as propylene oxide. For example, polyethylene polyol, polypropylene polyol, polyethylene polypropylene polyol (random or block copolymer) and the like can be mentioned. Examples of the polyether polyol include polytetramethylene ether glycol obtained by ring-opening polymerization of tetrahydrofuran.
These compounds C can be used alone or in combination of two or more.

The hydroxyl value of compound C (according to method B of JIS K1557-1 (2007)) is, for example, 3 to 600 mgKOH / g, preferably 5 to 300 mgKOH / g.
The average number of functional groups of compound C is, for example, 1 to 8, preferably 2 to 6. In addition, the average number of functional groups of the compound C can be calculated | required from the kind and mixture ratio of an initiator.
Mn of the compound C is, for example, 300 to 30000, preferably 700 to 20000. In addition, Mn of the compound C can also be calculated | required from the above-mentioned hydroxyl value and average functional group number.

  In compound D (a photopolymerizable compound having both a hydroxyl group and a photopolymerizable group), the photopolymerizable group is a photopolymerizable functional group, and specifically includes, for example, a (meth) acryloyl group, an alkenyl group. , Cinnamoyl group, cinnamylideneacetyl group, benzalacetophenone group, styrylpyridine group, α-phenylmaleimide group, phenylazide group, sulfonylazide group, carbonylazide group, diazo group, o-quinonediazide group, furylacryloyl group, coumarin Group, pyrone group, anthracene group, benzophenone group, stilbene group, dithiocarbamate group, xanthate group, 1,2,3-thiadiazole group, cyclopropene group, azadioxabicyclo group and the like. The photopolymerizable group is preferably a (meth) acryloyl group.

  In compound D, the number of hydroxyl groups and photopolymerizable groups is not particularly limited, and may be one (single) or two or more (plural). When compound D has a plurality of photopolymerizable groups, each photopolymerizable group may be the same or different from each other.

  Examples of the compound D include photopolymerizable compounds having one hydroxyl group and one photopolymerizable group in one molecule, such as the above-mentioned hydroxyl group-containing vinyl monomer, such as pentaerythritol tri (meth) acrylate, dipenta Photopolymerizable compounds having one hydroxyl group and two or more photopolymerizable groups in one molecule, such as erythritol penta (meth) acrylate, such as pentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate , 1 molecule such as 2,2-dihydroxyethyl acrylate, photopolymerizable compound having two or more hydroxyl groups and two or more photopolymerizable groups in one molecule, such as dipentaerythritol tetra (meth) acrylate And photopolymerizable compounds having two or more hydroxyl groups and one photopolymerizable group. That. These compounds D can be used alone or in combination of two or more.

  If necessary, compound D1 (a photopolymerizable compound having no hydroxyl group and having a photopolymerizable group) can be used in combination with compound D.

  Examples of the compound D1 include alkylene glycol di (meth) acrylates such as ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and neopentyl glycol di (meth) acrylate; for example, diethylene glycol di (meth) acrylate, Polyalkylene glycol di (meth) acrylates such as tetraethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate and tripropylene glycol di (meth) acrylate; for example, 1,4-butanediol di (meth) acrylate 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, dicyclopentadiene di (meth) acrylate, neopentylglyco Adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, dicyclopentanyl di (meth) acrylate; for example, bisphenol AEO addition diacrylate, caprolactone modified di Cyclopentenyl di (meth) acrylate, ethylene oxide-modified phosphoric acid di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate or alkylene oxide modified products thereof, divinylbenzene, butanediol-1,4 -Divinyl ether, cyclohexane dimethanol divinyl ether, diethylene glycol divinyl ether, dipropylene glycol divinyl ether dipro Lenglycol divinyl ether, hexanediol divinyl ether, triethylene glycol divinyl ether, phenylglycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer (AH-600, manufactured by Kyoeisha Chemical Co., Ltd.), phenylglycidyl ether acrylate toluene diisocyanate urethane prepolymer (AT-600) A photopolymerizable polyfunctional compound having two photopolymerizable groups in one molecule; such as trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, or their Photopolymerizable polyfunctional having three photopolymerizable groups in one molecule such as modified alkylene oxide and isocyanuric acid alkylene oxide modified tri (meth) acrylate Compound; for example, photopolymerizable polyfunctional compound having four photopolymerizable groups in one molecule, such as ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, or a modified alkylene oxide thereof; , Dipentaerythritol hexa (meth) acrylate, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer (UA-306H, manufactured by Kyoeisha Chemical Co., Ltd.), caprolactone-modified dipentaerythritol hexa (meth) acrylate, or alkylene oxide modified products thereof And a photopolymerizable polyfunctional compound having six photopolymerizable groups in one molecule thereof. These compounds D1 can be used alone or in combination of two or more.

  In addition, when using compound D and compound D1 together, those compounding ratios are 10-90 mass parts, for example, preferably 50-70 mass parts for compound D with respect to 100 mass parts of total amounts of compound D and compound D1. Compound D1 is, for example, 10 to 90 parts by mass, preferably 30 to 50% by mass.

And in manufacture of a coating material, the compounding ratio of each above-mentioned raw material component (namely, compound A, BC, and D) shall be as follows with respect to those 100 mass parts in total.
Compound A: For example, 5-90 parts by mass, preferably 10-80 parts by mass,
Compound B: For example, 1 to 40 parts by mass, preferably 5 to 30 parts by mass,
Compound C: For example, 1 to 60 parts by mass, preferably 5 to 40 parts by mass,
Compound D: For example, 5-70 parts by mass, preferably 10-50 parts by mass.

  When the blending ratio of each raw material component is within the above range, it is possible to improve the antifouling property of the coating surface obtained using the coating material and to ensure excellent wiping off of dirt.

  On the other hand, if the compounding ratio of the compound A is less than the lower limit, the coating surface obtained using the coating material is inferior in finger slipperiness and may not be able to sufficiently secure the ease of wiping off dirt. Moreover, when the compounding ratio of the compound A exceeds the above upper limit, the antifouling property of the coating surface obtained using the coating material cannot be sufficiently ensured, and for example, fingerprints may be easily attached.

  If the compounding ratio of the compound B is less than the above lower limit, the antifouling property of the coating surface obtained using the coating material cannot be sufficiently secured, and for example, fingerprints may be easily attached. Also, when the blending ratio of compound B exceeds the above upper limit, the antifouling property of the coating surface obtained using the coating material cannot be sufficiently ensured, for example, when fingerprints are likely to adhere. There is.

  If the compounding ratio of compound C is less than the above lower limit, the antifouling property of the coating surface obtained using the coating material cannot be sufficiently ensured, and, for example, fingerprints may easily adhere. Moreover, when the compounding ratio of the compound C exceeds the above upper limit, the slipperiness of the coating surface obtained using the coating material is inferior, and the ease of wiping off the dirt may not be ensured sufficiently.

  If the compounding prescription of compound D is less than the above lower limit, the slipperiness of the coating surface obtained using the coating material is inferior, and the ease of wiping off dirt may not be ensured sufficiently. Moreover, when the compounding prescription of the compound D exceeds the said upper limit, it may be inferior to the slipperiness | lubricity of the coating surface obtained using a coating material, and may not fully ensure the ease of wiping off of dirt.

In the reaction of each component described above, for example, a known method such as a one-shot method or a prepolymer method is employed, and a prepolymer method is preferably employed.
In the prepolymer method, first, compounds B, C, and D are reacted to synthesize a prepolymer having both an isocyanate group and a photopolymerizable group at the molecular end, and then the isocyanate group of the obtained prepolymer and compound A Is reacted with a hydroxyl group in the side chain. Specifically, first, the equivalent ratio of the isocyanate group in the compound B to the hydroxyl group in the compound C and D (NCO / hydroxyl group) is more than 1, for example, the compound B and the compounds C and D exceed 1.1, for example 1.1. It is formulated (mixed) so as to be 10 to 10, preferably 1.5 to 4.5, and is urethanated in a reaction vessel, for example, at room temperature to 150 ° C., for example, for 0.5 to 24 hours.

  In the urethanization reaction, an organic solvent can be blended if necessary. Examples of the organic solvent include the organic solvents described above. These organic solvents can be used alone or in combination of two or more. The mixing ratio of the organic solvent is appropriately set depending on the purpose and application.

  In the urethanization reaction, a urethanization catalyst can be added as necessary. Examples of the urethanization catalyst include dimethyltin dilaurate, dibutyltin dilaurate, dioctyltin laurate, dioctyltin dilaurate, and bismuth catalyst. These urethanization catalysts can be used alone or in combination of two or more.

  In the said urethanation reaction, a polymerization inhibitor can be further mix | blended as needed. Examples of the polymerization inhibitor include quinones such as p-benzoquinone, p-methoquinone, naphthoquinone, phenanthraquinone, toluquinone, and 2,5-diphenyl-p-benzoquinone, such as hydroquinone, p-t-butylcatechol, Hydroquinones such as 2,5-di-t-butylhydroquinone, mono-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, for example, p-methoxyphenol, di-t-butyl paracresol hydroquinone monomethyl And phenols such as ether. These polymerization inhibitors can be used alone or in combination of two or more. Of these, phenols are preferable, and p-methoxyphenol is more preferable.

Furthermore, if necessary, the unreacted compound B may be removed from the obtained prepolymer by a known removing means such as distillation or extraction. In the prepolymer, the average number of functional groups of the isocyanate group is, for example, 1 to 3.0, preferably 1 to 2.5.
Mw of the obtained prepolymer is, for example, 4000 to 40000, preferably 8000 to 25000. Mn of the prepolymer obtained is 1000-15000, for example, Preferably it is 2000-10000.

  Moreover, a prepolymer can also be prepared as a solution of an above-mentioned organic solvent, In that case, the solid content concentration is 10-90 mass%, for example, Preferably it is 20-80 mass%.

  When preparing a prepolymer as a solution, the viscosity (25 degreeC) is 2-20 mPa * s, for example, Preferably it is 5-10 mPa * s.

  Next, in this method, the obtained prepolymer and compound A are mixed, for example, in an organic solvent as described above, in which the equivalent ratio of isocyanate groups in the prepolymer to hydroxyl groups in compound A (NCO / hydroxyl group) is, for example, 0. 0.7-1.3, preferably 0.9-1.1, formulated (mixed), and urethanated in a reaction vessel, for example, at room temperature to 150 ° C., for example, for 0.5-24 hours Let In the urethanization reaction, as described above, the above-described urethanization catalyst and further a polymerization inhibitor can be added as necessary.

  According to the coating material obtained by such a prepolymer method, the antifouling property of the coating surface can be improved, and excellent ease of wiping off dirt can be ensured.

  A known additive such as an ultraviolet absorber, an antioxidant, a light stabilizer, a heat stabilizer, an antistatic agent, and an antifoaming agent can be added to the coating material of this example as necessary. .

  Such an additive can be added in advance to at least one of the above-described raw material components (that is, compounds A, B, C and D) and / or the above-mentioned prepolymer, and the prepolymer and the compound can be added in advance. It can be added separately during the reaction with A, and can also be added directly to the coating material obtained by the reaction between the prepolymer and compound A. In addition, the mixture ratio of an additive is suitably set according to the objective and use.

Mw of the coating material of this invention is 5000-100000, for example, Preferably it is 10000-80000. Mn of a coating material is 1000-50000, for example, Preferably it is 4000-40000.
The coating material of the present invention can also be prepared as a solution of the above-mentioned organic solvent. In that case, the solid content concentration is, for example, 10 to 90% by mass, preferably 20 to 80% by mass. When preparing a coating material as a solution, the viscosity (25 degreeC) is 1-100 mPa * s, for example, Preferably it is 5-80 mPa * s.

  And according to this coating material, while being able to aim at the improvement of the antifouling property of a coating surface, the outstanding wiping property and sliding property can be ensured.

Next, examples of the curable resin include a thermosetting resin and an ionizing radiation curable resin.
Examples of the thermosetting resin include melamine resin, phenol resin, and urethane resin. These thermosetting resins can be used alone or in combination of two or more. As the ionizing radiation curable resin, a photopolymerizable prepolymer that is crosslinked and cured by irradiation with ionizing radiation (ultraviolet rays or electron beams) can be used. The photopolymerizable prepolymer is preferably an acrylic prepolymer having two or more acryloyl groups in one molecule and having a three-dimensional network structure by crosslinking and curing.

Specific examples of the acrylic prepolymer include urethane acrylate, polyester acrylate, epoxy acrylate, melamine acrylate, polyfluoroalkyl acrylate, and silicone acrylate. These acrylic prepolymers can be used alone or in combination of two or more. As the acrylic prepolymer, preferably, urethane acrylate is used.
The photopolymerizable prepolymer can be used alone as an ionizing radiation curable resin. However, from the viewpoint of improving cross-linking curability and hardness, a photopolymerizable monomer can be used in combination with the photopolymerizable prepolymer.

  Examples of the photopolymerizable monomer include monofunctional acrylic monomers such as 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and butoxyethyl acrylate; for example, 1,6-hexanediol diacrylate, neopentyl glycol Bifunctional acrylic monomers such as diacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, hydroxypivalate ester neopentyl glycol diacrylate; for example, polyfunctional (such as dipentaerythritol hexaacrylate, trimethylpropane triacrylate, pentaerythritol triacrylate) Trifunctional or more) acrylic monomers; and the like. These photopolymerizable monomers can be used alone or in combination of two or more. The blending ratio of the photopolymerizable monomer is not particularly limited, and is appropriately set according to the purpose and application.

In the present invention, for example, an ionizing radiation curable organic-inorganic hybrid resin may be used as the ionizing radiation curable resin. Unlike conventional composites typified by glass fiber reinforced plastic (FRP), ionizing radiation curable organic / inorganic hybrid resins are closely mixed in organic and inorganic materials, and the dispersion state is at or near the molecular level. Therefore, the film can be formed by the reaction between the inorganic component and the organic component by irradiation with ionizing radiation.
Examples of the inorganic component in the hybrid resin include metal oxides such as silica and titania, and preferably silica. Examples of the silica include reactive silica in which a photosensitive group having photopolymerization reactivity is introduced on the surface. Reactive silica having an average particle diameter of preferably 1 nm or more, preferably 100 nm or less, more preferably 10 nm or less is used. By using reactive silica having an average particle diameter in a predetermined range, it becomes easy to maintain transparency when formed into a film. The content of the inorganic component in the hybrid resin is preferably 65% by weight or less, more preferably 40% by weight or less. By setting the content of the inorganic component to 65% by weight or less, it becomes easy to maintain transparency when formed into a film.

  The organic component in the hybrid resin includes a compound having a polymerizable unsaturated group polymerizable with the inorganic component (preferably reactive silica) (for example, a polyvalent compound having two or more polymerizable unsaturated groups in the molecule). Unsaturated organic compounds, or monounsaturated organic compounds having one polymerizable unsaturated group in the molecule).

  These curable resins can be used alone or in combination of two or more.

  As the curable resin, an ionizing radiation curable resin is preferably used. If an ionizing radiation curable resin is used as the curable resin, excellent scratch resistance can be imparted to the resulting cured product.

  The ionizing radiation curable resin can be obtained as a commercially available product. Specifically, for example, Unidic 17-813 (urethane acrylate, solid content 80%, manufactured by DIC), purple light UV 7600BA (urethane acrylate, solid content) 80%, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.).

  The curable resin can also be prepared as a solution of the organic solvent described above. In that case, the solid content concentration is, for example, 10 to 90% by mass, preferably 20 to 80% by mass.

  The curable composition of this invention can be obtained by mixing and stirring the above-mentioned coating material and curable resin.

In the curable composition, the blending ratio of the coating material and the curable resin is such that the blending ratio of the coating material (solid content) is preferably 2 parts by mass or more, more preferably 5 masses, with respect to the total amount of 100 parts by mass. Part or more, more preferably 10 parts by weight or more, preferably 40 parts by weight or less, more preferably 30 parts by weight or less.
Further, the blending ratio of the curable resin (solid content) is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, preferably 98 parts by mass or less, more preferably 95 parts by mass or less, and still more preferably 90 parts by mass. It is below mass parts.

  In the present invention, if the coating material is contained in the curable composition even in a small amount, improvement in fingerprint resistance and finger slipping can be expected. Therefore, in the present invention, the blending ratio of the coating material is not particularly limited. However, as a preferred embodiment, when the blending ratio of the coating material is equal to or more than the lower limit (2 parts by mass), the anti-fingerprint property and finger slip property can be further improved. Moreover, if the mixture ratio of a coating material is below the said upper limit (40 mass parts), it can prevent that moisture resistance and abrasion resistance fall.

  In the present invention, even when a large amount of the curable resin is contained in the curable composition, both anti-fingerprint properties and slipperiness can be achieved. Therefore, in the present invention, the blending ratio of the curable resin is not particularly limited. However, as a preferred embodiment, when the blending ratio of the curable resin is not more than the above upper limit (98 parts by mass), it is possible to easily prevent the anti-fingerprint property and the finger slipping property from being lowered. Moreover, if the mixture ratio of curable resin is more than the said minimum (60 mass parts), moisture resistance and scratch resistance can be made favorable.

  When using an ionizing radiation curable resin as the curable resin and curing the ionizing radiation curable resin by ultraviolet irradiation, in addition to the above-mentioned photopolymerizable prepolymer and photopolymerizable monomer, if necessary, photopolymerization is started. Additives such as an agent and a photopolymerization accelerator can be blended in the curable composition.

  As photopolymerization initiators, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, acetophenone, benzophenone, Michler ketone, benzoin, benzylmethyl ketal, benzoylbenzoate, α -Acyl oxime ester, thioxanthone, etc. are mentioned. These photopolymerization initiators can be used alone or in combination of two or more. When the photopolymerization initiator is blended, the blending ratio is, for example, 3 to 7 parts by mass with respect to 100 parts by mass of the total amount (solid content) of the coating material and the curable resin.

  The photopolymerization accelerator is one that can reduce polymerization damage due to air during curing and increase the curing speed, and examples thereof include p-dimethylaminobenzoic acid isoamyl ester and p-dimethylaminobenzoic acid ethyl ester. . These photopolymerization accelerators can be used alone or in combination of two or more. In the case where the photopolymerization accelerator is blended, the blending ratio is not particularly limited, and is appropriately set according to the purpose and application.

  In the curable composition, in the range that does not inhibit the above-described performance, for example, surfactants such as leveling agents and antifoaming agents, for example, additives such as antioxidants and ultraviolet absorbers, Known additives such as pigments for imparting antiglare properties and antiblocking properties can also be blended. In addition, the mixture ratio of an additive is not restrict | limited in particular, According to the objective and a use, it sets suitably.

  Moreover, the curable composition can also be prepared as a solution of the above-mentioned organic solvent. In that case, the solid content concentration is, for example, 10 to 90% by mass, preferably 20 to 80% by mass.

  As the base material in the case where the hard coat layer is formed on the base material, the same materials as those used in the surface protective film described above are used.

An example of a method for producing a hard coat film is as follows.
After apply | coating the above-mentioned curable composition to the base-material surface and making it dry as needed, it hardens | cures by irradiation of an ionizing radiation, or a heating, for example. Thereby, the hard coat film in which the hard coat layer was formed on the surface of the substrate can be produced.

  Examples of the coating method include coating by a dip coating method, a spray coating method, a roll coating method, a doctor blade method, a screen printing method, and the like, casting using a bar coater, an applicator, and the like.

  Moreover, a hard coat film can also be obtained by methods other than the above method, for example, a transfer method. In the transfer method, for example, first, the above-described curable composition is applied to the surface of a known release paper, and after drying as necessary, for example, is cured by irradiation with ionizing radiation or heating to form a hard coat layer. . Thereafter, after the obtained hard coat layer is pressure-bonded to the substrate, the release paper is peeled off (transferred) to obtain a hard coat film.

  The hard coat film with the surface protective film of the present invention can be produced by bonding the surface protective film of the present invention to the hard coat film (hard coat layer) thus obtained through the adhesive layer. . Further, by using the surface protective film of the present invention, it is possible to improve the antifouling property of the surface even after the surface protective film is peeled off, and to have excellent wiping properties and slipperiness. Can be secured.

  The hard coat film with a surface protective film of the present invention, after peeling the surface protective film as necessary, for example, the surface of a display device in an electronic device main body, a cover glass of a clock or a meter, a window glass, a showcase, etc. And is preferably used for protecting the surface thereof. Preferably, it can be used for the surface protection use of the electronic device main body.

Next, although this invention is demonstrated based on a synthesis example, a preparation example, an Example, and a comparative example, this invention is not limited by the following Example. In this example, “parts” and “%” are based on mass unless otherwise specified.
In addition, the measuring method of the physical property used in a synthesis example etc. is shown below.

<Measurement of Mw and Mn by gel permeation chromatography>
About 0.2 mg of a sample was collected, dissolved in 10 mL of tetrahydrofuran, and measured by GPC equipped with RID to obtain a molecular weight distribution of the sample. Thereafter, Mw of the sample was calculated from the obtained chromatogram (chart) using standard polystyrene as a calibration curve. The measurement apparatus and measurement conditions are shown below.
-Data processing device: product number HLC-8220GPC (manufactured by Tosoh Corporation)
-RID: RI detector built in the product number HLC-8220GPC-Column: 3 product numbers TSKgel GMHXL (manufactured by Tosoh Corporation)-Mobile phase: tetrahydrofuran-Column flow rate: 0.5 mL / min
・ Injection volume: 20μL
・ Measurement temperature: 40 ℃
Standard polystyrene molecular weight: 1250, 3250, 9200, 28500, 68000, 165000, 475000, 950000, 1900000

<Viscosity>
The viscosity at 25 ° C. of the sample was measured according to JIS K 5600-2-3: 1999 using a cone plate viscometer.

<Hydroxyl value>
The hydroxyl value of the sample was measured in accordance with method B (phthalation method) of JIS K1557-1 (2007).

[Synthesis of Compound a]
<< Synthesis Example A-1 >>
In a reaction vessel, 233 parts of methyl ethyl ketone (hereinafter, MEK) was charged as a solvent, and the temperature was raised to 85 ° C. Meanwhile, 4 parts of azobis-2-methylbutyronitrile (ABN-E, manufactured by Nippon Hydrazine Kogyo Co., Ltd.) as a polymerization catalyst was added to a monomer composition consisting of 90 parts of methyl methacrylate and 10 parts of 2-hydroxyethyl acrylate. A monomer mixture was prepared by stirring and mixing. Next, the monomer mixture is dropped into the above solvent at 85 ° C. over 2 hours, and after completion of the dropwise addition, the mixture is aged for 4 hours, whereby a solution of an acrylic polymer (compound A) having a hydroxyl group in the side chain (solid content 30%) Got.
Mw of the obtained compound A was 18000, Mn was 9500, Tg was 88 degreeC, the viscosity (25 degreeC) was 7 mPa * s, and the hydroxyl value was 17 mgKOH / g. Mw, Mn, viscosity and hydroxyl value were determined by the above methods. The glass transition temperature was calculated by Fox's equation.

[Prepolymer synthesis]
<< Synthesis Example B-1 >>
In a reaction vessel, 233 parts of MEK was charged as a solvent, and the temperature was raised to 80 ° C. Next, 15 parts of diisocyanate (compound B: hexamethylene diisocyanate) in a reaction vessel, polyether polyol (compound C: polyoxyethylene polyoxypropylene glycol, Epan U-105, Mn: 6400, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) ), 30 parts of a photopolymerizable compound (a mixture of a compound D having both a hydroxyl group and a photopolymerizable group and a photopolymerizable compound D1 having no hydroxyl group and having a photopolymerizable group: dipentaerythritol pentaacrylate and dipenta 55 parts of erythritol hexaacrylate mixture, Aronix M-403, pentaerythritol pentaacrylate content 50-60%, NCO / OH equivalent ratio 2.9, manufactured by Toagosei Co., Ltd.), and dimethyltin dilaurate 0 as a catalyst .1 part and p-methoxyphene as a polymerization inhibitor 0.05 parts of diol was added and mixed at 80 ° C. for 3 hours.

Thereby, a solution (solid content 30%) of a prepolymer (reaction product of compounds B, C, D and D1) having both an isocyanate group and a photopolymerizable group at the molecular end was obtained.
Mw of the obtained prepolymer was 12000, Mn was 4000, and the viscosity (25 ° C.) was 7 mPa · s. In addition, Mw, Mn, and viscosity were calculated | required by said method.

[Preparation of coating material]
<< Synthesis Example C-1 >>
In a reaction vessel, 20 parts of the compound A solution obtained in Synthesis Example A-1 and 80 parts of the prepolymer solution obtained in Synthesis Example B-1 were charged, and dimethyltin dilaurate was added as a catalyst. 1 part and 0.05 part of p-methoxyphenol as a polymerization inhibitor were added and mixed at 80 ° C. for 3 hours to obtain a coating material solution (solid content 30%). Mw of the obtained coating material was 19000, Mn was 6000, and the viscosity (25 ° C.) was 7 mPa · s. In addition, Mw, Mn, and viscosity were calculated | required by said method.

<< Synthesis Example C-2 >>
In a reaction vessel, 40 parts of the compound a solution obtained in Synthesis Example A-1 and 60 parts of the prepolymer solution obtained in Synthesis Example B-1 were charged, and dimethyltin dilaurate was added as a catalyst. 1 part and 0.05 part of p-methoxyphenol as a polymerization inhibitor were added and mixed at 80 ° C. for 3 hours to obtain a coating material solution (solid content 30%). Mw of the obtained coating material was 19000, Mn was 8000, and the viscosity (25 ° C.) was 7 mPa · s. In addition, Mw, Mn, and viscosity were calculated | required by said method.

[Preparation of hard coat layer paint]
A curable composition was prepared by mixing and stirring the following components.
-6.67 parts of coating material solution (solid content 30%) obtained in Synthesis Example C-1 (solid content of coating material: 2 parts)
・ Ionizing radiation curable resin (solid content 80%) 122.5 parts (Unidic 17-813: urethane acrylate, manufactured by DIC Corporation)
(Urethane acrylate solid content: 98 parts)
Photopolymerization initiator 3 parts (1-hydroxy-cyclohexyl-phenyl-ketone)
(Irgacure 184, manufactured by Ciba Japan)
・ Dilute solvent (butyl acetate) 200 parts

[Manufacture of hard coat film]
The hard coat layer paint is applied to one side of a 100 μm polyester film (Cosmo Shine A4300: Toyobo Co., Ltd.), dried and cured by ultraviolet irradiation to form a hard coat layer having a thickness of 5 μm. Was made.

  Instead of the coating material solution obtained in Synthesis Example C-1, the coating material solution obtained in Synthesis Example C-2 (solid content 30%) was used, and the amount added was 50 parts (solid content 15 parts). A hard coat film B was produced in the same manner as in Example 1 except that the amount of ionizing radiation curable resin was changed to 106.25 parts (solid content: 85 parts).

[Production of surface protective film]
[Example 1]
The following adhesive layer coating material was applied and dried on one surface of a 100 μm polyester film (ester film: Toyobo Co., Ltd.) to form an adhesive layer having a thickness of 5 μm, and the surface protective film of Example 1 was produced.
<Adhesive layer paint>
・ Polyol-containing urethane adhesive 100 parts by weight (Olivein EXK13-565: Toyochem, solid content 64.2%)
・ Isocyanate-based curing agent 15 parts by weight (Siavine T-501B: Toyochem, solid content 75.0%)
・ 150 parts by weight of diluting solvent

[Comparative Example 1]
The following adhesive layer coating material was applied and dried on one surface of a 100 μm polyester film (ester film: Toyobo Co., Ltd.) to form an adhesive layer having a thickness of 5 μm, and the surface protective film of Example 1 was produced.
<Adhesive layer paint>
・ Acrylic adhesive 100 parts by weight (Cooponyl N7600: Nippon Synthetic Chemical Co., Ltd., solid content 30%)
・ 3 parts by weight of curing agent (Coronate HX: Nippon Polyurethane, solid content 100%)
・ 10 parts by weight of diluted solvent

  Example 1, surface protective film of Comparative Example 1, and commercially available surface protective film A (Puretect VL29G: Tohello), surface protective film B (Puretect VL27HR: Tohoku), surface protective film C (Sanitet MS14L: Sanei Kaken) ) The adhesive layer of D and the hard coat film A or the hard coat layer of the hard coat film B were bonded together, left at room temperature for 1 day, the surface protective film was peeled off, and the following items were evaluated.

[Friction force by synthetic leather]
Example 1, Comparative Example 1, hard coat film 1 after peeling off commercially available surface protective films A to D, fixed on glass plate 21 with the hard coat layer facing up, The synthetic leather 22, glass 23 (6.5 cm × 6.5 cm), weight 24 (load 1 kg) are arranged in this order, and then an eyeball clip 25 is attached to the other end of the leatherette, and a spring balance is placed in the hole of the eyeball clip 25. 26 hooks were hooked. Next, the spring balance 26 was pulled, and the load when the synthetic leather 22 started to move on the hard coat layer was measured. Moreover, it measured similarly about the hard-coat layer before sticking the surface protection film of each test piece.
The frictional force after peeling the surface protective film is within 0.8 to 1.5 times the frictional force before sticking the surface protective film, “O”, smaller than 0.8, or larger than 1.5 times The thing was made into "x". The results are shown in Table 1 together with the frictional force of the hard coat layer before the surface protective film is adhered / the value of the frictional force of the hard coat layer after the surface protective film is peeled off.

[Finger slipperiness]
Example 1, Comparative Example 1, and commercially available surface protective films A to D were fixed with the hard coat film on the glass so that the hard coat layer would be on top, and touched with a finger to attach the surface protective film. It was evaluated whether there was a difference in finger slipperiness compared to the hard coat layer before wearing. “○” indicates that 3 or more of 5 people felt that there was no change, and “X” indicates that 3 or more of 5 people felt that there was a change. The results are shown in Table 1.

  In the surface protective film of Example 1, the frictional force of the hard coat film after peeling the surface protective film is within 0.8 to 1.5 times the frictional force before sticking the surface protective film of the hard coat film. The finger slipperiness was not different.

  Since the surface protective film of Example 1 includes a two-component curable urethane-based pressure-sensitive adhesive composed of a polyol and an isocyanate-based curing agent, the frictional force due to the synthetic leather is within 0.8 to 1.5 times, and finger sliding There was no difference in sex.

DESCRIPTION OF SYMBOLS 1 ... Hard coat film, 21, 23 ... Glass, 22 ... Synthetic leather, 24 ... Weight, 25 ... Eye clip, 26 ... Spring balance

Claims (4)

A surface protective film for protecting a hard coat film,
The surface protective film has an adhesive layer formed on one surface of the substrate,
The surface protective film is obtained by sticking the surface protective film to the hard coat film, and the friction force of the hard coat film after peeling is 0.8 to 1.% of the friction force before sticking the surface protective film of the hard coat film. A surface protective film characterized by being 5 times or less. A surface protective film for protecting a hard coat film,
The hard coat film is provided with finger slipperiness,
The surface protective film has an adhesive layer formed on one surface of the substrate,
The pressure-sensitive adhesive layer of the surface protective film comprises a two-component curable urethane pressure-sensitive adhesive comprising (a) a polyol and (b) an isocyanate-based curing agent.   The ratio of the (b) isocyanate curing agent to the (a) polyol in the adhesive layer is characterized in that (b) the isocyanate curing agent is 10 to 25 parts by weight with respect to 100 parts by weight of the polyol. The surface protective film according to claim 1. A hard coat film with a surface protective film,
The hard coat film is provided with finger slipperiness,
The surface protective film is formed by forming a pressure-sensitive adhesive layer containing a two-component curable urethane pressure-sensitive adhesive composed of (a) a polyol and (b) an isocyanate-based curing agent on one surface of a substrate. Hard coat film.

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