JPH10166531A - Hard coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contain two types of polyester resins having different glass transition points and crosslinker as main components in a laminated film in a laminate having a hard coating layer provided at least on one surface of a polyester film via the laminated film. SOLUTION: The hard coating film comprises a laminated polyester film having a laminated film containing two types of polyester resins having two types of different specific Tg (glass transition point) and crosslinker as main components. Thus, it has high surface hardness, excellent wear resistance, excellent adhesive properties of the hard coating layer and simultaneously develops excellent effect of adhesive properties even after wet heat treating. Accordingly, it can be used for wide applications such as display to be laminated on a touch panel, glass or metal plate, label, seal or OHP, or a card, cut form for a home delivery service, or an image receiving sheet for printer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard coat film, and more particularly, to a hard coat film having a high surface hardness and excellent abrasion resistance as well as excellent adhesion of a hard coat layer under moist heat. It is.

[0002]

2. Description of the Related Art Biaxially oriented polyester films have excellent properties such as mechanical properties, dimensional stability, heat resistance, transparency, and electrical insulation. It is widely used as a base film for many uses such as various photographic materials and graphic arts materials. However, the surface hardness of the film surface is low,
In addition, due to lack of abrasion resistance, the surface is easily damaged by contact with other hard objects, friction, scratching, etc. Or become unusable.

For this reason, a method is known in which a polyester film is used as a base film, and a hard coat layer having excellent scratch resistance and abrasion resistance is provided on the base film. Therefore, the adhesiveness to the hard coat layer is poor, and the hard coat layer is peeled off from the base film, which has a disadvantage of substantially inferior durability. Therefore, conventionally, studies have been made on imparting adhesiveness to the polyester film surface by various methods.

[0004] As a method for imparting adhesion, corona discharge treatment, ultraviolet irradiation treatment,
Surface activation method such as plasma treatment, acid, alkali,
A surface etching method using an agent such as an aqueous amine solution, and a method in which various resins such as an acrylic resin, a polyester resin containing a sulfonate group, and a urethane resin are provided as a primer layer on the film surface (JP-A-55-15825, JP-A-58-158). No. 77861, JP-A-60-24823
No. 2 is already known. In particular, as a method of providing the primer layer by application and imparting adhesiveness, a coating liquid containing the resin component is applied to a polyester film before completion of crystal orientation, dried, stretched, and subjected to heat treatment. A method for completing the crystal orientation (in-line coating method) is considered to be promising in terms of process simplification and manufacturing cost, and is being actively performed.

Further, a polyester resin laminated film in which a heat bonding layer composed of two types of polyester resins obtained by copolymerizing a softening component is laminated by a co-extrusion method or the above-described in-line coating method (Japanese Patent Laid-Open No. 2-16050).
Also, a method has been proposed in which a coating layer made of a urethane resin is provided on the surface of a polyester film, and a surface hardened layer is provided thereon (JP-A-62-263237).

[0006]

However, the above-mentioned prior art has the following problems.

[0007] When a base polyester film laminated with an acrylic resin or a urethane resin is used to impart adhesiveness, the laminated film has excellent adhesion to a hard coat layer as a coating material, Adhesion to the polyester film tends to be insufficient. Furthermore, recently, hard coat films have been used for various applications, and under severe conditions which could not be imagined, for example, in a state where the humidity is high and the ambient temperature is high (in the present invention) In this case, such a state is referred to as "under moist heat"), the adhesiveness of the hard coat layer is extremely insufficient, and a situation in which the function as a hard coat film cannot be satisfied often occurs.

Further, when a base polyester film laminated with a polyester resin is used, the laminated film has good adhesion to the base polyester film, but has insufficient adhesion to the hard coat layer. Adhesiveness is often not obtained, and, as a matter of course, as in the case of the acrylic resin or urethane resin, the adhesiveness with the hard coat layer under moist heat is further deteriorated.

As a method for improving the adhesiveness under wet heat described above, a method for improving the adhesiveness by crosslinking a resin is generally considered. For example, there is an acrylic resin, a urethane resin, or a polyester resin to which a melamine-based crosslinking agent, an isocyanate-based crosslinking agent, or an epoxy-based crosslinking agent is added. However, there has not been obtained a product which has both the adhesiveness under normal conditions and the adhesiveness under wet heat.

[0010] Further, as disclosed in Japanese Patent Application Laid-Open No. 2-16050, a laminated film composed of two types of polyester resins obtained by copolymerizing a softening component is provided on a base polyester film under normal conditions. Is extremely excellent, but no satisfactory adhesiveness under wet heat has been obtained.

The present invention has solved these drawbacks and has achieved not only the adhesion between the base polyester film and the laminated film, but also
It is an object of the present invention to provide a hard coat film having excellent adhesiveness with a hard coat layer and excellent adhesiveness under wet heat.

[0012]

According to the present invention, there is provided a hard coat film according to the present invention, wherein a hard coat layer is provided via a laminated film provided on at least one side of a polyester film. Has two types of polyester resins having different glass transition points and a crosslinking agent (C) as main components, and the polyester resin (A) having a high glass transition point has a glass transition point of 60 ° C. or more and 110 ° C. or less. The polyester resin (B) having a low glass transition point has a glass transition point of less than 60 ° C.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the polyester constituting the polyester film is a generic term for polymers having an ester bond as a main bonding chain of a main chain. Preferred polyesters include ethylene terephthalate and ethylene- 2,6-naphthalate, butylene terephthalate, ethylene-α, β-bis (2-chlorophenoxy)
Those having at least one component selected from ethane-4,4'-dicarboxylate and the like as a main component can be used. One of these components may be used alone or two or more of them may be used in combination. Among them, it is preferable to use a polyester containing ethylene terephthalate as a main component when comprehensively judging quality, economy and the like.

In general, an actinic ray-curable resin is used as a resin constituting the hard coat layer. In such a case, the resin often shrinks at the time of curing. Superior polyethylene-2,6-naphthalate is more preferred.

[0015] These polyesters may further contain some other dicarboxylic acid component or diol component, preferably 2 or more.
0 mol% or less may be copolymerized.

Further, various additives such as antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, and fillers are contained in the polyester. , An antistatic agent, a nucleating agent and the like may be added to such an extent that their properties are not deteriorated.

The intrinsic viscosity of the above-mentioned polyester (25 ° C.
Measured in o-chlorophenol) is 0.4-1.2.
dl / g is preferable, and more preferably 0.5 to 0.8 d
Those in the range of 1 / g are suitable for practicing the present invention.

The polyester film using the above polyester is preferably biaxially oriented when the laminated film is provided. The biaxially oriented polyester film generally means an unstretched polyester sheet or film in the longitudinal direction and the width direction.
It is stretched about 5 to 5 times, and then heat-treated to complete crystal orientation, and indicates a biaxially oriented pattern by wide-angle X-ray diffraction.

The thickness of the polyester film is not particularly limited, and is appropriately selected according to the use in which the hard coat film of the present invention is used.
From the viewpoint of handling properties and the like, preferably 1 to 500 μ
m, more preferably 5 to 300 μm. Further, the obtained films can be used by being bonded by various methods.

In label applications, a white polyester film can be suitably used as a base film in addition to a transparent polyester film.
The white polyester film is not particularly limited as long as it is a white-colored polyester film, and preferably has a whiteness of 85 to 150%, more preferably 90 to 130%, and an optical density of preferably 0 to 130%. .5
To 5, more preferably 1.2 to 3. For example, when a base film having a small whiteness is used, the pattern or coloring on the opposite surface is transmitted and the appearance of the printed layer on the surface is easily impaired.On the other hand, when the optical density is small, sufficient light reflection is not obtained. However, when viewed with the naked eye, whiteness is reduced and the opposite surface is affected, which is not preferable as a white polyester film.

The method for obtaining such optical density and whiteness is not particularly limited, but can usually be obtained by adding a resin incompatible with inorganic particles or polyester. The amount to be added is not particularly limited, but is preferably 5 to 35% by weight, more preferably 8 to 2% in the case of inorganic particles.
5% by weight. On the other hand, when an incompatible resin is added, it is preferably 5 to 35% by volume, more preferably 8 to 2% by volume.
5% by volume.

The inorganic particles are not particularly limited, but preferably have an average particle size of 0.1 to 4 μm, more preferably 0.3 to 4 μm.
1.5 μm inorganic particles and the like can be used as typical examples. Specifically, barium sulfate, calcium carbonate, calcium sulfate, titanium oxide, silica, alumina, talc, clay and the like or a mixture thereof can be used.These inorganic particles are other inorganic compounds, for example,
It may be used in combination with calcium phosphate, titanium oxide, mica, zirconia, tungsten oxide, lithium fluoride, calcium fluoride and the like. Further, among the above-mentioned inorganic particles, those having a Mohs hardness of 5 or less, preferably 4 or less are more preferable because the whiteness is further increased.

The resin incompatible with the above-mentioned polyester is not particularly limited. For example, in the case of mixing with polyethylene terephthalate or polyethylene-2,6-naphthalate, acrylic resin, polyethylene, polypropylene, modified olefin resin , Polybutylene terephthalate resin, phenoxy resin, polyphenylene oxide, and the like may be used, and may be used in combination with the above-described inorganic particles. For example, in particular, a white polyester film having a specific gravity of 0.5 to 1.3, which is obtained by mixing a resin incompatible with inorganic particles or polyester and biaxially stretching and having a cavity inside, is preferable because the printing characteristics are improved. .

Polyester resin (glass transition point (hereinafter abbreviated as Tg)) which is a component of the laminated film according to the present invention
The polyester resin having a higher Tg is referred to as a polyester resin (A), and the polyester resin having a lower Tg is referred to as a polyester resin (B).

In the present invention, two kinds of polyester resins having different Tg are used. The two kinds of polyester resins have different Tg, and the Tg of the polyester resin (A) is different.
g is 60 ° C. or more and 110 ° C. or less, and if the Tg of the polyester resin (B) satisfies that it is less than 60 ° C., the dicarboxylic acid component of the polyester resin (A) and the polyester resin (B) The same component can be used as the copolymer component such as the diol component.

The polyester resin which is a component of the laminated film according to the present invention has an ester bond in a main chain or a side chain. Such a polyester resin is obtained by polycondensation from a dicarboxylic acid and a diol. Can be done.

As the carboxylic acid component constituting the polyester resin, aromatic, aliphatic and alicyclic dicarboxylic acids and trivalent or higher polycarboxylic acids can be used. As aromatic dicarboxylic acids, terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 2,5-dimethylterephthalic acid,
1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bisphenoxyethane-p, p'-dicarboxylic acid, phenylindanedicarboxylic acid, and the like can be used. These aromatic dicarboxylic acids are preferably 30 mol% or more of all dicarboxylic acid components in view of strength and heat resistance of the laminated film.
It is more preferable to use 35 mol% or more, most preferably 40 mol% or more. Examples of the aliphatic and alicyclic dicarboxylic acids include succinic acid, adipic acid, sebacic acid, dodecandioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and 1,4-cyclohexane. Dicarboxylic acids and the like and ester-forming derivatives thereof can be used.

When the polyester resin is used as a coating solution containing an aqueous resin, a compound containing a sulfonate group or a carboxylic acid group may be used to improve the adhesiveness of the polyester resin or to make the polyester resin water-soluble. It is preferable to copolymerize a compound containing an acid base.

Examples of the compound containing a sulfonate group include sulfoterephthalic acid, 5-sulfoisophthalic acid,
4-sulfoisophthalic acid, 4-sulfonaphthalene-2,
7-dicarboxylic acid, sulfo-p-xylylene glycol, 2-sulfo-1,4-bis (hydroxyethoxy)
Benzene or the like, or an alkali metal salt, an alkaline earth metal salt, or an ammonium salt thereof can be used, but is not limited thereto.

Examples of the compound containing a carboxylate group include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tricarboxylic acid, trimesic acid, ,
2,3,4-butanetetracarboxylic acid, 1,2,3,4
-Pentanetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-cyclohexene-
1,2-dicarboxylic acid, cyclopentanetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid,
1,2,5,6-naphthalenetetracarboxylic acid, ethylene glycol bistrimellitate, 2,2 ', 3,3'
-Diphenyltetracarboxylic acid, thiophene-2,3
4,5-Tetracarboxylic acid, ethylenetetracarboxylic acid and the like, or alkali metal salts, alkaline earth metal salts, and ammonium salts thereof can be used, but are not limited thereto.

The diol component of the polyester resin includes ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3
-Butanediol, 1,4-butanediol, 1,5-
Pentanediol, 1,6-hexanediol, 1,7
-Heptanediol, 1,8-octanediol, 1,
9-nonanediol, 1,10-decanediol, 2,
4-dimethyl-2-ethylhexane-1,3-diol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3 -Methyl-1,5
-Pentanediol, 2,2,4-trimethyl-1,6
-Hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-
Cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4′-thiodiphenol, bisphenol A, 4,4′-methylenediphenol, 4,4 ′-(2 -Norbornylidene)
Diphenol, 4,4′-dihydroxybiphenol,
o-, m-, and p-dihydroxybenzene, 4,4 '
-Isopropylidenephenol, 4,4'-isopropylidenebindiol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, bisphenol A and the like can be used.

As the preferred polyester resin (A), polyester is used. As an acid component, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, phenylindanedicarboxylic acid, trimellitic acid, pyromellitic acid,
-(2,5-dioxotetrahydrofurfuryl) -3-
Methyl-3-cyclohexene-1,2-dicarboxylic acid,
Examples of the diol component include a copolymer selected from ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, and bisphenol A.

As the polyester resin used in the present invention, a modified polyester copolymer, for example, a block copolymer or a graft copolymer modified with acryl, urethane, epoxy or the like can be used.

The polyester resin used for the laminated film according to the present invention can be produced by the following production method. For example, a polyester resin composed of terephthalic acid, isophthalic acid, 5-sodium sulfoisophthalic acid as a dicarboxylic acid component, ethylene glycol as a diol component, and neopentyl glycol,
Terephthalic acid, isophthalic acid, 5-sodium sulfoisophthalic acid and ethylene glycol, neopentyl glycol directly esterification reaction, or terephthalic acid,
Isophthalic acid, 5-sodium sulfoisophthalic acid and ethylene glycol, a first step of transesterification with neopentyl glycol, and a method of producing by the second step of a polycondensation reaction of the reaction product of the first step, etc. Can be manufactured.

At this time, as a reaction catalyst, for example, an alkali metal, an alkaline earth metal, manganese, cobalt, zinc, antimony, germanium, a titanium compound or the like is used.

As a method for obtaining a polyester resin having a large amount of carboxylic acid at the terminal and / or side chain,
JP-A-54-46294, JP-A-60-2090
No. 73, JP-A-62-240318, JP-A-53-26828, JP-A-53-26829, JP-A-53-98336, JP-A-56-11
No. 6,718, JP-A-61-124684, JP-A-62-240318, etc. can be produced with a resin obtained by copolymerizing a trivalent or higher polycarboxylic acid. It may be a method.

The intrinsic viscosity of the polyester resin of the laminated film according to the present invention is not particularly limited, but is preferably at least 0.3 dl / g, more preferably at least 0.35 dl / g, from the viewpoint of adhesiveness. Most preferably 0.4 dl
/ G or more.

Here, in the present invention, it is essential that the Tg of the polyester resin (A) is not lower than 60 ° C. and not higher than 110 ° C., whereby excellent adhesiveness can be obtained under normal conditions. In addition, it is possible to achieve both adhesiveness under wet heat. Furthermore, according to the findings of the present inventors,
The polyester resin (A) has a Tg of at least 65 ° C.
C. or lower, more preferably 70 ° C. or higher and 90 ° C. or lower.

The polyester resin (B) has a different Tg from the above-mentioned polyester resin (A).
Is less than 60 ° C., the above-mentioned polyester resin (A)
The same copolymer components as the dicarboxylic acid component and the diol component can be used. Furthermore, according to the findings of the present inventors, the Tg of the polyester resin (B) is preferably from -10 ° C to 50 ° C, more preferably from 0 ° C to 40 ° C.

In the present invention, from the viewpoint of adhesiveness, it is preferable that 1,4-butanediol, neopentyl glycol and polyethylene glycol are copolymerized as the diol component of the polyester resin (B). It is preferable that pentyl glycol is copolymerized. In addition, sebacic acid, adipic acid, and azelaic acid are preferably copolymerized as a dicarboxylic acid component from the viewpoint of adhesiveness.

The copolymerization ratio of neopentyl glycol in the diol component is preferably 35 to 90 mol%, more preferably 40 to 70 mol%.

The copolymerization of polyethylene glycol is effective for making the polyester resin water-soluble.
Among them, those having a molecular weight of 600 to 20,000 are preferable, more preferably 1000 to 6000, and the copolymerization ratio is preferably 0.2 to 10 mol% in the diol component, more preferably 0.4 to 5 mol%. Mol%. Further, since the above-mentioned copolymerization ratio changes greatly depending on the molecular weight of polyethylene glycol even if the copolymerization ratio is the same, the copolymerization amount of polyethylene glycol is preferably 1 to 20% by weight in terms of% by weight in the polyester resin. , More preferably 2 to 15% by weight.

Polyester is preferred as the polyester resin (B). Terephthalic acid, isophthalic acid, sebacic acid, adipic acid, trimellitic acid, pyromellitic acid, 5- (2,5-dioxotetrahydrofurfuryl)- 3-methyl-3-cyclohexene-1,2-dicarboxylic acid, ethylene glycol as a diol component,
And copolymers selected from diethylene glycol, 1,4-butanediol, neopentyl glycol, and polyethylene glycol.

In the laminated film according to the present invention, the polyester resin (A) and the polyester resin (B) are
By adding the cross-linking agent (C), the adhesiveness under normal conditions is improved, and the adhesiveness under wet heat is dramatically improved.

The cross-linking agent referred to in the present invention is not particularly limited, but can cross-link with a functional group present in the polyester resin, for example, a hydroxyl group or a carboxyl group. Urea, melamine, acrylamide, polyamide resins, epoxy compounds, isocyanate compounds, oxazoline compounds, aziridine compounds, various silane coupling agents, various titanate coupling agents, etc. . In particular, it has been found that the addition of a melamine-based crosslinking agent dramatically improves the adhesiveness particularly under wet heat.

The melamine cross-linking agent used is not particularly limited, but is partially or completely etherified by reacting a lower alcohol with melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, or a methylolated melamine. Compounds and mixtures thereof can be used. Further, as a melamine-based cross-linking agent, a monomer, a condensate comprising a multimer of a dimer or more,
Alternatively, a mixture thereof or the like can be used. As the lower alcohol used for the etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like can be used. As the functional group, an imino group, a methylol group,
Alternatively, those having an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group in one molecule, an imino group type methylated melamine resin, a methylol group type melamine resin,
Methylol group type methylated melamine resin, fully alkyl type methylated melamine resin and the like. Among them, a methylolated melamine resin is most preferable. Further, an acidic catalyst such as p-toluenesulfonic acid may be used in order to promote the thermal curing of the melamine-based crosslinking agent.

The polyester resin (A), the polyester resin (B), and the crosslinking agent (C) can be used in a mixture at an arbitrary ratio. To make the effect of the present invention more remarkable, the following is required. It is advisable to mix them in a ratio. The polyester resin (A) / polyester resin (B) preferably has a solid content weight ratio of 10/90 to 70/30 in terms of adhesiveness under normal conditions, and more preferably 15/85 to 5/50.
0/50, most preferably 20/80 to 40/60.

Further, the cross-linking agent not only has an adhesive property under normal conditions but also has an adhesive property under a high temperature and a high humidity. The amount is preferably 0.5 to 20 parts by weight, more preferably 1 to 15 parts by weight, and most preferably 2 to 10 parts by weight. When the amount of the melamine-based cross-linking agent is less than 0.5 part by weight, the effect of the addition is small, and when it exceeds 20 parts by weight, the adhesiveness tends to decrease.

The laminated film of the present invention comprises the above-mentioned two kinds of polyester resins having different Tg and a cross-linking agent as main constituent components. It means that it occupies more than weight%. In particular, in the present invention, the ratio of the two components is preferably 80% by weight or more, more preferably 90% by weight or more.

In the laminated film, other resins such as a polyester resin other than the above-mentioned polyester resin, an acrylic resin, a urethane resin, an epoxy resin, and the like, as long as the effects of the present invention are not impaired. A silicone resin, a urea resin, a phenol resin or the like may be blended.

Further, various additives such as an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, an organic lubricant, and the like may be contained in the laminated film within a range that does not impair the effects of the present invention.
Pigments, dyes, organic or inorganic fine particles, fillers, antistatic agents, nucleating agents and the like may be blended.

In particular, those obtained by adding inorganic particles to the laminated film are more preferable because the lubricity and the blocking resistance are improved.

In this case, as the inorganic particles to be added, silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate and the like can be used. The inorganic particles used have an average particle size of 0.0
1-5 μm is preferable, and more preferably 0.05-3 μm
m, most preferably 0.08 to 2 μm, and the mixing ratio with respect to the resin in the laminated film is not particularly limited, but is preferably 0.05 to 8 parts by weight, more preferably 0.1 to 3 parts by weight in terms of solid content weight ratio. Parts by weight.

In producing the hard coat film of the present invention, preferred methods for providing a laminated film include:
The method of applying during the production process of the polyester film and stretching together with the base film is most preferred. For example, the melt-extruded polyester film before crystal orientation is stretched about 2.5 to 5 times in the longitudinal direction, and a coating liquid is continuously applied to the uniaxially stretched film. The applied film is dried while passing through a stepwise heated zone, and is stretched about 2.5 to 5 times in the width direction. Furthermore, continuously 1
It can be obtained by a method (in-line coating method) of being guided to a heating zone of 50 to 250 ° C. and completing the crystal orientation. The coating solution used in this case is preferably an aqueous solution in view of environmental pollution and explosion-proof properties.

In the present invention, before applying the coating liquid,
The surface of the base film (in the case of the above example, the uniaxially stretched film) is subjected to a corona discharge treatment or the like, and the wetting tension of the surface is preferably 47 mN / m or more, more preferably 50 mN / m or more.
mN / m or more can be preferably used because the adhesiveness of the laminated film to the base film can be improved.

The thickness of the laminated film is not particularly limited, but is usually preferably in the range of 0.01 to 5 μm, more preferably 0.02 to 2 μm, and most preferably 0.05 μm to 0.2 μm.
5 μm. If the thickness of the laminated film is too small, poor adhesion may occur.

Various coating methods such as a reverse coating method, a gravure coating method, a rod coating method, a bar coating method, a die coating method, a spray coating method and the like can be used as a coating method on the substrate film.

The hard coat layer according to the present invention includes acrylic, urethane, melamine, organic silicate,
It can be configured as one composed of a silicone-based or metal oxide. In particular, a silicone type and an acrylic type are preferable in terms of hardness and durability, and an acrylic type, particularly an active ray-curable acrylic type is preferable in terms of curability, flexibility and productivity.

The actinic ray-curable acrylic system contains an acrylic oligomer as an actinic ray polymerization component and a reactive diluent, and, if necessary, a photoinitiator, a photosensitizer,
Those containing a modifying agent may be used.

The acrylic oligomer includes polyester acryl, urethane acryl, epoxy acryl, polyether acryl, and the like, including those in which a reactive acryl group is bonded to an acrylic resin skeleton, and melamine and isocyanuric acid. A rigid skeleton having an acrylic group bonded thereto may be used, but the present invention is not limited thereto.

The reactive diluent is used as a solvent for a coating agent in the coating step and functions as a solvent in the coating step, and itself has a group that reacts with a monofunctional or polyfunctional acrylic oligomer. It becomes a copolymer component.

Particularly, in the case of crosslinking by ultraviolet rays, since the light energy is small, it is preferable to add a photopolymerization initiator and / or a photosensitizer in order to promote the conversion and initiation of the light energy.

Specific examples of these acrylic oligomers, reactive diluents, photopolymerization initiators, photosensitizers, crosslinking devices, etc. are described in Shinzo Yamashita, Tosuke Kaneko, "Handbook of Crosslinking Agents",
Taiseisha, published in 1981, pages 267 to 275, and pages 562 to 593, can be referred to.
It is not limited to these. Mitsubishi Rayon Co., Ltd. as a multifunctional acrylic UV curable paint as a commercial product,
Use products of Fujikura Kasei Co., Ltd., Dainichi Seika Kogyo Co., Ltd., Dainippon Ink & Chemicals Co., Ltd., Toa Gosei Chemical Co., Ltd., Nitto Kasei Co., Ltd., Nippon Kayaku Co., Ltd. However, the present invention is not limited to these.

As a modifier for the hard coat layer, a coating improver, an antifoaming agent, a thickener, an antistatic agent, an inorganic particle, an organic particle, an organic lubricant, an organic polymer, a dye, a pigment, Stabilizers and the like can be used, and these are used as a composition of the coating layer within a range that does not impair the reaction by actinic rays,
The properties of the hard coat layer can be improved depending on the application.

Among these, in particular, at least one monomer having three or more (meth) acryloyloxy groups in one molecule and one to two ethylenically unsaturated double bonds in one molecule. A hard coat layer made of an actinic ray-cured material mainly composed of an actinic ray-curable monomer mixture composed of at least one kind of a monomer having a bond has hardness, curability, wear resistance, and wear resistance. It is preferable because it has excellent flexibility.

In the present invention, three or more (meth) acryloyloxy groups in one molecule (however, in the present invention, (meth) acryloyloxy group is an abbreviation of acryloyloxy group and methacryloyloxy group). As a monomer having three or more alcoholic hydroxyl groups in one molecule, wherein the hydroxyl group is an esterified product of three or more (meth) acrylic acids. Can be used.

As specific examples, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate ) Acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate and the like can be used. These monomers may be used alone or in combination of two or more.

The proportion of the monomer having three or more (meth) acryloyloxy groups in one molecule is preferably 20 to 90% by weight, more preferably 30 to 90% by weight, based on the total amount of the polymerizable monomer. ~ 80% by weight, most preferably 30 ~
70% by weight.

When the proportion of the above-mentioned monomer is less than 20% by weight, it may not be sufficient in that a cured film having sufficient abrasion resistance is obtained, and the amount exceeds 90% by weight. In such a case, it is not preferable because the shrinkage due to polymerization is large, and the cured film may be left with distortion, the flexibility of the film may be reduced, or the cured film may be greatly curled.

The monomer having one or two ethylenically unsaturated double bonds in one molecule as used in the present invention is not particularly limited as long as it is an ordinary monomer having radical polymerizability. be able to.

As the compound having two ethylenically unsaturated double bonds in the molecule, the following (meth) acrylates (a) to (f) can be used.

(A) (Meth) acrylic acid diesters of alkylene glycols having 2 to 12 carbon atoms: ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) (B) (meth) acrylate diesters of polyoxyalkylene glycol such as acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate;
Diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, etc. (C) (meth) acrylic acid diesters of polyhydric alcohols: (d) (meth) acrylic acid diesters of ethylene oxide and propylene oxide adducts of bisphenol A or hydrogenated bisphenol A, such as pentaerythritol di (meth) acrylate Classes: 2,2'-bis (4-acryloxyethoxyphenyl) propane, 2,2'-bis (4-
Acryloxypropoxyphenyl) propane,
(E) a diisocyanate compound and a terminal isocyanate group-containing compound obtained by previously reacting two or more alcoholic hydroxyl group-containing compounds with an alcoholic hydroxyl group-containing (meth) acrylate, and two or more molecules in a molecule obtained by reacting the compound. Urethane (meth) acrylates having a (meth) acryloyloxy group, (f) two or more molecules in a molecule obtained by reacting acrylic acid or methacrylic acid with a compound having two or more epoxy groups in the molecule; (Meta)
Epoxy (meth) acrylates having an acryloyloxy group can be used, and as the compound having one ethylenically unsaturated double bond in the molecule, methyl (meth) acrylate, ethyl (meth) acrylate, n- and i-propyl (meth) acrylate, n
-, Sec-, and t-butyl (meth) acrylate;
2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, hydroxyethyl (meth)
Acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, N-hydroxyethyl (meth) acrylamide, N-vinylpyrrolidone, N-vinyl- 3-methylpyrrolidone, N-vinyl-
5-methylpyrrolidone and the like can be used. These monomers may be used alone or in combination of two or more.

The proportion of the monomer having one or two ethylenically unsaturated double bonds in one molecule is preferably from 10 to 80% by weight, more preferably from 20 to 80% by weight, based on the total amount of the monomer. ７０70% by weight. If the proportion of the monomer exceeds 80% by weight, it is not preferable because a cured film having sufficient abrasion resistance is hardly obtained. Also,
If the use ratio is less than 10% by weight, the flexibility of the coating film may be reduced, or the adhesiveness to the laminated film provided on the base polyester film may be reduced, which is not preferable.

As a method for curing the actinic ray-curable composition of the present invention, a method of irradiating ultraviolet rays can be used. When this method is used, it is desirable to add a photopolymerization initiator to the composition. Specific examples of the photopolymerization initiator include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, 4,4′-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, methylbenzoylformate, p
-Isopropyl-α-hydroxyisobutylphenone,
carbonyl compounds such as α-hydroxyisobutylphenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone And sulfur compounds such as benzoyl peroxide and di-t-butyl peroxide. These photopolymerization initiators may be used alone or in combination of two or more.

The photopolymerization initiator is suitably used in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the polymerizable monomer composition. When electron beam or gamma ray is used as the curing means, it is not always necessary to add a polymerization initiator.

The actinic ray-curable composition used in the present invention includes:
Hydroquinone, hydroquinone monomethyl ether, to prevent thermal polymerization during production and dark reaction during storage
It is desirable to add a thermal polymerization inhibitor such as 2,5-t-butylhydroquinone. The addition amount is preferably 0.005 to 0.05% by weight based on the total weight of the polymerizable compound.

The actinic ray-curable composition used in the present invention includes:
For the purpose of improving workability at the time of coating and controlling the coating film thickness, an organic solvent may be blended as long as the effects of the present invention are not impaired.

The organic solvent has a boiling point of 50 to 150 ° C.
Are easy to use in terms of workability during coating and dryness before and after curing. Specific examples include alcohol solvents such as methanol, ethanol, and isopropyl alcohol; acetate solvents such as methyl acetate, ethyl acetate and butyl acetate; ketone solvents such as acetone and methyl ethyl ketone; and aromatic solvents such as toluene. And a cyclic ether-based solvent such as dioxane.
These solvents can be used alone or in combination of two or more.

The actinic ray-curable composition used in the present invention includes:
Various additives can be blended as needed as long as the effects of the present invention are not impaired. For example, stabilizers such as antioxidants, light stabilizers, and ultraviolet absorbers, surfactants, leveling agents, and antistatic agents can be used.

The actinic ray-curable composition used in the present invention includes:
For the purpose of reducing the brightness and clarity of the reflected image of the external light source, a matting agent such as silicon oxide particles or an organic filler can be blended within a range that does not impair the effects of the present invention.
The surface of the surface hardening layer may be provided with irregularities by, for example, an embossing method, a sand matting method, or the like.

As means for applying the actinic ray-curable composition,
Conventional coating methods such as brush coating, dip coating, knife coating, roll coating, spray coating, flow coating, and spin coating (spinner, wheyer, etc.) can be used. Each method has its own characteristics, the required characteristics of the laminate,
The application method may be appropriately selected depending on the intended use.

Here, the actinic ray means an electromagnetic wave such as an ultraviolet ray, an electron beam, or a radiation (α ray, β ray, γ ray, etc.) which polymerizes an acrylic vinyl group. Is preferable. As the ultraviolet source, an ultraviolet fluorescent lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a carbon arc lamp, and the like can be used. In addition, the electron beam method requires an expensive apparatus and requires operation under an inert gas, but is advantageous in that it does not need to contain a photopolymerization initiator or a photosensitizer in the coating layer. .

The thickness of the hard coat layer may be determined according to the intended use, and is usually preferably 0.5 μm to 10 μm.
More preferably, it is 1 μm to 5 μm. When the thickness of the hard coat layer is less than 0.5 μm, the surface hardness is insufficient and the surface is easily scratched. On the other hand, when the thickness exceeds 10 μm, the cured film tends to be brittle, and when the laminate is folded, It is not preferable because cracks easily occur in the cured film.

A print layer such as a design may be provided as the outermost layer of the hard coat layer as long as the effects of the present invention are not impaired.

Further, the hard coat film of the present invention is
It can also be used by attaching it to a mating material using various adhesives on the surface opposite to the surface where the hard coat layer is provided, and imparting a function of the hard coat layer such as abrasion resistance and scratch resistance to the mating material. .

The pressure-sensitive adhesive used at this time is not particularly limited as long as the two objects are adhered to each other by their adhesive action, and those made of rubber, acrylic, silicone, polyvinyl ether, etc. may be used. Can be. Above all, rubber-based materials are generally used, and silicone-based materials have good heat resistance and have a disadvantage that they are sticky to fluororesins and the like, but are expensive. Acrylic resins are preferred because they also have heat resistance, have a large adhesive strength, and do not have the oxidative deterioration of rubber.

Further, the pressure-sensitive adhesive is roughly classified into a solvent-type pressure-sensitive adhesive and a solvent-free pressure-sensitive adhesive. Solvent-based pressure-sensitive adhesives excellent in drying property, productivity, and processability are still mainstream, but in recent years, they have been shifted to solvent-free pressure-sensitive adhesives in terms of pollution, energy saving, resource saving, safety, and the like. Among them, it is preferable to use an active ray-curable pressure-sensitive adhesive, which is a pressure-sensitive adhesive that cures in seconds by irradiation with actinic rays and has excellent properties such as flexibility, adhesion, and chemical resistance.

For specific examples of the actinic ray-curable acrylic pressure-sensitive adhesive, reference can be made to “Adhesive Data Book” edited by The Adhesive Society of Japan, published by Nikkan Kogyo Shimbun, 1990, pages 83 to 88. However, the present invention is not limited to these. Hitachi Chemical Polymer Co., Ltd., Toho Kasei Kogyo Co., Ltd.
Products such as Three Bond Co., Ltd., Toa Gosei Chemical Industry Co., Ltd., Cemedine Co., Ltd., and Nippon Kayaku Co., Ltd. can be used, but not limited thereto.

When this type of pressure-sensitive adhesive is applied to a normal biaxially stretched polyester film, the adhesion becomes insufficient, and various types of primer treatment, for example, acrylic resin,
By providing a laminated film made of a polyester resin, a urethane resin, or the like, the adhesiveness between the polyester film and the pressure-sensitive adhesive layer can be improved. Needless to say, a laminated film composed of two kinds of polyester resins and a cross-linking agent according to the present invention may be provided.

Next, the method for producing a hard coat film of the present invention will be described with reference to polyethylene terephthalate (hereinafter abbreviated as PET) as a substrate film, but the present invention is not limited to this.

The hard coat film of the present invention having a high surface hardness, excellent abrasion resistance and excellent durability has a specific Tg on at least one side of the polyester film and has a different Tg. It can be manufactured by providing a laminated film composed of various kinds of polyester resins and a crosslinking agent, and providing a hard coat layer composed of an actinic radiation cured material on one surface.

More specifically, the PET pellets are sufficiently dried in a vacuum, and then supplied to an extruder.
It is melt-extruded into a sheet at a temperature of ° C. and solidified by cooling to produce an unstretched PET sheet. This sheet is 70-120
The film is stretched 2.5 to 5 times in the longitudinal direction with a roll heated to 0 ° C. to obtain a uniaxially oriented PET film. At least one surface of the film is subjected to a corona discharge treatment, and a coating liquid for forming a laminated film having a predetermined concentration is applied to the treated surface. After coating, the end of the film is gripped with a clip and guided to a hot-air zone heated to 70 to 150 ° C., dried, and then 2.5 to 5 in the width direction.
Stretch twice. Subsequently, it is led to a heat treatment zone of 160 to 250 ° C. and heat treated for 1 to 30 seconds to complete the crystal orientation. During this heat treatment step, a relaxation treatment of 1 to 12% may be performed in the width direction or the longitudinal direction as necessary.
In this case, the coating solution to be used is preferably an aqueous solution in view of environmental pollution and explosion-proof properties.

The hard coat film of the present invention can be obtained by providing a hard coat layer on one surface of the above-mentioned laminated polyester film. The hard coat layer can be obtained by applying a composition containing an actinic ray-curable monomer mixture as a main component, drying the composition if necessary, and then curing the composition with actinic radiation.

In the above example, the base film on which the laminated film is provided may contain at least one selected from the group consisting of polyester resins, melamine-based crosslinking agents, and reaction products thereof. In this case, there are effects that the adhesiveness between the laminated film and the base film is improved, and the lubricity of the laminated polyester film is improved. When a polyester resin, a melamine-based cross-linking agent, or a reaction product thereof is contained, one kind or a plurality of kinds, the total amount of addition of which is 5 ppm or more and less than 20% by weight, It is preferable in terms of lubricity. of course,
The polyester resin, the melamine-based cross-linking agent, or a reaction product thereof may be a laminated film forming composition (including a recycled pellet of the laminated polyester film according to the present invention) provided on the base film.

The hard coat film thus obtained has a high surface hardness, excellent abrasion resistance, and excellent durability of the hard coat layer, so that it can be used for a wide range of applications.

More specifically, touch panels, displays for bonding to glass or metal plates, displays for electronic whiteboards and whiteboards, labels, stickers, OHP, cards,
It can be used for home delivery slips, printer receiving paper, and various surface protection materials, such as covers for calculators and instruments. In addition, for a coated metal plate, it can be used for home appliances, office equipment, building materials, vehicles, steel furniture, and the like.

[0097]

[Method for measuring characteristics and method for evaluating effects] The method for measuring characteristics and the method for evaluating effects in the present invention are as follows.

(1) Thickness of Coating Layer The thickness was determined from a photograph obtained by observing a cross section of a biaxially oriented polyester film provided with a laminated film using a transmission electron microscope HU-12 manufactured by Hitachi, Ltd. Thickness is 30 within the field of view
The average value was used.

(2) Adhesion-1 Under normal conditions (23 ° C., relative humidity 65%), 100 1 mm ² cross cuts were put on the hard coat layer of the hard coat film of the present invention, and were manufactured by Nichiban Co., Ltd. A cellophane tape is stuck on it and a load of 1
After reciprocating three times at 9.6 N, pressing, peeling in the direction of 90 degrees, and four-level evaluation based on the number of remaining hard coat layers (◎: 100, ○: 80 to 99, Δ: 50 to 79, ×:
0-49). (A) and (B) were evaluated as having good adhesiveness.

(3) Adhesiveness-2 The hard coat film of the present invention was subjected to heat and humidity (80
C., 90% relative humidity) for 2 hours. After the treatment, it was taken out immediately, left for 5 minutes under normal conditions (23 ° C., 65% relative humidity), and evaluated in the same manner as in the above (2).

(4) Pencil hardness Pencils of various hardnesses were applied to the hard coat layer at an angle of 90 degrees according to JIS-K5400, scratched with a load of 9.8 N, and indicated by the hardness of the pencil when scratches occurred. And used as an index of surface hardness.

(5) Abrasion resistance The surface of the hard coat layer was rubbed with steel wool # 0000, and the degree of scratching was evaluated according to the following criteria. (○),
(△) is a level that is practically acceptable.

：: scarcely scratched even when rubbed △: slightly scratched when rubbed ×: scratched

(6) Glass transition point (Tg) “Robot” DSC (differential scanning calorimeter) RDC220 manufactured by Seiko Electronic Industry Co., Ltd.
The measurement was performed with an SC5200 disk station connected. The measurement conditions of DSC are as follows. That is, sample 1
After adjusting 0 mg to an aluminum pan, it is set in a DSC device (reference: an aluminum pan of the same type without a sample), heated at a temperature of 300 ° C. for 5 minutes, and then quenched in liquid nitrogen. This sample is
The temperature is raised at 0 ° C./min, and the glass transition point (Tg) is detected from the DSC chart.

[0105]

Next, the present invention will be described with reference to examples, but is not necessarily limited thereto.

Example 1 PET pellets containing 0.015% by weight of colloidal silica having an average particle diameter of 0.4 μm and 0.005% by weight of colloidal silica having an average particle diameter of 1.5 μm (intrinsic viscosity: 0.63 dl / g) ) Is sufficiently vacuum-dried, supplied to an extruder, melted at 285 ° C., extruded into a sheet shape from a T-shaped die, and subjected to a surface temperature of 25 using an electrostatic application casting method.
It was wrapped around a mirror-surfaced casting drum at ℃ to be cooled and solidified. This unstretched film was heated to 95 ° C. and stretched 3.5 times in the longitudinal direction to obtain a uniaxially stretched film. The film was subjected to a corona discharge treatment in air, the wet tension of the substrate film was set to 52 mN / m, and the following coating liquid for forming a laminated film was applied to the treated surface. While holding the applied uniaxially stretched film with a clip, it is led to a preheating zone,
After that, the film was continuously stretched 3.5 times in the width direction in a heating zone at 125 ° C., and further subjected to a heat treatment in a heating zone at 230 ° C. to obtain a laminated PET film in which crystal orientation was completed. At this time, the thickness of the base PET film was 188 μm.
m, and the thickness of the laminated film was 0.15 μm.

Next, on this laminated PET film, 70 parts by weight of dipentaerythritol hexaacrylate, N
A composition obtained by stirring and mixing 30 parts by weight of vinylpyrrolidone and 4 parts by weight of 1-hydroxycyclohexylphenyl ketone was cured with a bar coater to a thickness of 3 μm.
Was applied uniformly. 9c from the coated surface
Ultraviolet rays were irradiated for 15 seconds with a high-pressure mercury lamp having an irradiation intensity of 80 W / cm set at a height of m and cured to obtain a hard coat film having a hard coat layer on the laminated PET film. Table 1 shows the results.

"Laminated film forming coating liquid" (A): polyester resin ・ acid component 88 mole% terephthalic acid 12 mole% 5-sodium sulfoisophthalic acid ・ diol component ethylene glycol 100 mole% Polyester comprising the above acid component and diol component Water-soluble coating liquid of resin (Tg: 82 ° C).

(B): polyester resin acid component 50 mole% terephthalic acid 49 mole% isophthalic acid 1 mole% 5-sodium sulfoisophthalic acid diol component ethylene glycol 55 mole% neopentyl glycol 44 mole% polyethylene glycol (molecular weight: 4000) 1 mol% A water dispersion of a polyester resin (Tg: 29 ° C.) comprising the acid component and the diol component.

(C): Crosslinking agent: A coating solution prepared by diluting methylolated melamine in a mixed solvent of isopropyl alcohol and water (25/75 (weight ratio)).

(A) / (B) / (C) = 40/60/5
(Solid content weight ratio) to obtain a coating liquid for forming a laminated film.

Example 2 The coating liquid for forming a laminated film of Example 1 was prepared using the polyester resin (B)
Was obtained in the same manner as in Example 1 except that the following polyester was used. Table 1 shows the results.

(B): polyester resin acid component 50 mole% terephthalic acid 29 mole% isophthalic acid 20 mole% 5-sodium sulfoisophthalic acid 1 mole% diol component ethylene glycol 55 mole% neopentyl glycol 44 mole% Polyethylene glycol (molecular weight: 4000) 1 mol% A water dispersion of a polyester resin (Tg: -4 ° C) comprising the above acid component and diol component.

Example 3 Example 2 was repeated except that the mixture ratio of (A) / (B) was changed to 25/75 (weight ratio of solid content) in the coating liquid for forming a laminated film of Example 2.
A hard coat film was obtained in the same manner as described above. Table 1 shows the results
Shown in

Example 4 With the coating liquid for forming a laminated film of Example 3, the total of (A) and (B) was 1
A hard coat film was obtained in the same manner as in Example 3, except that 10 parts by weight of the crosslinking agent (C) was mixed with 00 parts by weight. Table 1 shows the results.

Example 5 The coating liquid for forming a laminated film of Example 3 was prepared using the polyester resin (A)
A hard coat film was obtained in the same manner as in Example 3 except that the following was used as the copolymerized polyester. Table 1 shows the results.

(A): Polyester resin Acid component Naphthalene dicarboxylic acid 75 mol% Isophthalic acid 24 mol% 5-sodium sulfoisophthalic acid 1 mol% Diol component Ethylene glycol 55 mol% Neopentyl glycol 44 mol% Polyethylene glycol (molecular weight) : 4000) 1 mol% A water dispersion of a polyester resin (Tg: 95 ° C) comprising the acid component and the diol component.

Example 6 In the coating liquid for forming a laminated film of Example 1, the crosslinking agent (C) was changed to an aqueous oxazoline group-containing water-soluble polymer “Epocross” WS-500 (manufactured by Nippon Shokubai Co., Ltd.) as an aqueous crosslinking agent. A hard coat film was obtained in the same manner as in Example 1 except for the above. Table 1 shows the results.

Example 7 In Example 4, the polyester film was changed from polyethylene terephthalate film to polyethylene-2,6-
A hard coat film was obtained in the same manner as in Example 4, except that the film was changed to a naphthalate (hereinafter abbreviated as "PEN") film. Table 1 shows the results.

Example 8 On the laminated PET film of Example 4, 60 parts by weight of pentaerythritol triacrylate and 2,2′-bis (4
-Acryloxydiethoxyphenyl) propane 10 parts by weight, N-vinylpyrrolidone 30 parts by weight, 1-hydroxycyclohexylphenyl ketone 4 parts by weight, toluene 90
A composition obtained by stirring and mixing parts by weight, 70 parts by weight of butyl acetate, and 70 parts by weight of isopropyl alcohol was uniformly applied using a bar coater so that the cured film thickness became 3 μm. This was dried at 80 ° C. for 20 seconds. A hard coat film was obtained in the same manner as in Example 4 except that this was irradiated with ultraviolet light in a nitrogen atmosphere. Table 1 shows the results.

Example 9 PE containing 14% by weight of titanium dioxide having an average particle size of 0.2 μm and 0.5% by weight of silica having an average particle size of 1 μm
T pellets (intrinsic viscosity: 0.63 dl / g) are sufficiently dried in vacuum, then supplied to an extruder and melted at 285 ° C.
The sheet was extruded into a sheet shape from a letter-shaped die, wound around a mirror-surface casting drum having a surface temperature of 25 ° C. using an electrostatic application casting method, and cooled and solidified. This unstretched film is
The film was heated to 5 ° C. and stretched 3.2 times in the longitudinal direction to obtain a uniaxially stretched film. This film is subjected to a corona discharge treatment in the air, and the wetting tension of the base film is set to 52 mN / m.
The same coating liquid for forming a laminated film as in Example 4 was applied to the treated surface. The coated uniaxially stretched film is guided to a preheating zone while being gripped with clips, dried at 110 ° C., and then continuously stretched 3.2 times in the width direction in a 125 ° C. heating zone, and further in a 230 ° C. heating zone. Heat treatment was performed to obtain a white laminated PET film provided with a laminated film whose crystal orientation was completed. At this time, the thickness of the base white PET film was 25
The optical density was 1.5 μm, the whiteness was 85%, and the thickness of the laminated film was 0.15 μm.

A hard coat layer was provided on the obtained white laminated PET film in the same manner as in Example 4 to obtain a hard coat film. Table 1 shows the results.

Example 10 Polytetramethylene glycol was previously prepared by adding polytetramethylene glycol at the time of polymerization of polybutylene terephthalate so that the weight ratio of polybutylene terephthalate to polytetramethylene glycol (molecular weight: 4000) was 1: 1. 1% by weight of butylene terephthalate-polytetramethylene glycol copolymer and polymethylpentene (TPX, DX820, manufactured by Mitsui Petrochemical Co., Ltd.)
Wt% PET pellet (intrinsic viscosity 0.63d
1 / g) is sufficiently dried in vacuum, and then supplied to an extruder A heated to 285 ° C. In addition, the same PET pellets as described above are sufficiently dried in vacuum, and then supplied to an extruder B heated to 285 ° C. The polymers extruded from the extruders A and B are laminated by co-extrusion so as to have a three-layer structure of B / A / B, extruded into a sheet shape from a T-shaped die, and the surface temperature is determined using an electrostatic application casting method. It was wound around a mirror casting drum at 25 ° C. and solidified by cooling.
This unstretched film is heated to 95 ° C. and moved in the longitudinal direction.
The film was stretched four times to obtain a uniaxially stretched film. This film was subjected to a corona discharge treatment in air, the wet tension of the substrate film was set to 52 mN / m, and the same coating solution for forming a laminated film as in Example 4 was applied to the treated surface. The coated uniaxially stretched film is guided to a preheating zone while being gripped with clips, and
After drying at ℃, continuously stretched 3.4 times in the width direction in a heating zone at 125 ℃, further heat-treated in a heating zone at 230 ℃, to provide a white laminated PET film having a crystal orientation-completed laminated film I got At this time, the base material white PET
Film thickness is 125 μm (thickness ratio is B / A / B = 5 /
90/5), the optical density was 1.2, the whiteness was 70%, and the thickness of the laminated film was 0.15 μm.

The obtained white laminated PET film was provided with a hard coat layer in the same manner as in Example 4 to obtain a hard coat film. Table 1 shows the results.

Comparative Example 1 Table 2 shows the results obtained in the case of Example 1 except that the laminated film was not provided and the hard coat layer was provided.

Comparative Example 2 The coating liquid for forming a laminated film of Example 1 was prepared using the polyester resin (A)
A hard coat film was obtained in the same manner as in Example 1, except that the polyester resin (B) was a copolymerized polyester resin shown below, and the crosslinking agent (C) was not mixed. Table 2 shows the results.

(A): Polyester resin-Acid component 99% by mole of terephthalic acid 1% by mole of 5-sodium sulfoisophthalic acid-Diol component 70% by mole of ethylene glycol 30% by mole of neopentyl glycol Polyester resin comprising the above acid component and diol component (Tg: 66 ° C) water dispersion.

(B): polyester resin acid component terephthalic acid 50 mol% isophthalic acid 29 mol% sebacic acid 20 mol% 5-sodium sulfoisophthalic acid 1 mol% diol component ethylene glycol 55 mol% neopentyl glycol 44 mol% Polyethylene glycol (molecular weight: 4000) 1 mol% A water dispersion of a polyester resin (Tg: -4 ° C) comprising the above acid component and diol component.

Comparative Example 3 The coating liquid for forming a laminated film of Example 1 was prepared using the polyester resin (A)
A hard coat film was obtained in the same manner as in Example 1, except that the polyester resin (B) was a copolymerized polyester resin shown below, and the crosslinking agent (C) was not mixed. Table 2 shows the results.

(A): polyester resin acid component 50 mole% terephthalic acid 49 mole% isophthalic acid 1 mole% 5-sodium sulfoisophthalic acid 1 mole component diol component ethylene glycol 55 mole% neopentyl glycol 44 mole% polyethylene glycol (molecular weight: 4000) 1 mol% A water dispersion of a polyester resin (Tg: 29 ° C.) comprising the acid component and the diol component.

(B): polyester resin ・ acid component 56 mole% terephthalic acid 18 mole% isophthalic acid 20 mole% sebacic acid 6 mole% ・ glycol component ethylene glycol 30 mole% neopentyl glycol 36 mole% 1,4 -Butanediol 34 mol% An ammonium salt-type aqueous dispersion of a polyester resin (glass transition point: 20 ° C) comprising the above acid component and glycol component.

Comparative Example 4 The coating liquid for forming a laminated film of Comparative Example 3 was used in a total of 1 for (A) and (B).
A hard coat film was obtained in the same manner as in Comparative Example 3, except that 5 parts by weight of a methylolated melamine was used as a crosslinking agent with respect to 00 parts by weight. Table 2 shows the results.

Comparative Example 5 The coating liquid for forming a laminated film of Example 1 was prepared using the polyester resin (A)
A hard coat film was obtained in the same manner as in Example 1, except that the polyester resin (B) was changed to the following copolymerized polyester resin. Table 2 shows the results.

(A): Polyester resin ・ Acid component 88% by mole of terephthalic acid 12% by mole of 5-sodium sulfoisophthalic acid ・ Diol component 100% by mole of ethylene glycol Polyester resin comprising the above acid component and diol component (Tg: 82 ° C.) Water-soluble coating liquid.

(B): Polyester resin ・ Acid component 50% by mole of terephthalic acid 49% by mole of isophthalic acid 1% by mole of 5-sodium sulfoisophthalic acid ・ Diol component 82% by mole of ethylene glycol 18% by mole of neopentyl glycol 18% by weight of the above acid component and diol Water dispersion of polyester resin (Tg: 70 ° C.) composed of components.

Comparative Example 6 A hard coat film was obtained in the same manner as in Example 1, except that only the following polyester resin was used as the coating liquid for forming a laminated film. Table 2 shows the results.

Polyester resin ・ Acid component 56 mol% terephthalic acid 18 mol% Trimellitic acid 20 mol% Sebacic acid 6 mol% ・ Diol component ethylene glycol 30 mol% neopentyl glycol 36 mol% 1,4-butanediol 34 Mol% An aqueous ammonium salt type dispersion of a polyester resin (Tg: 20 ° C.) comprising the acid component and the diol component.

Comparative Example 7 Comparative Example 6 was repeated except that the following coating liquid was used as the crosslinking agent in the laminated film forming coating liquid of Comparative Example 6 at a polyester resin / crosslinking agent = 100/3 (weight ratio of solid content). A hard coat film was obtained in the same manner as described above. Table 2 shows the results.

Crosslinking agent: A coating solution obtained by diluting methylolated melamine in a mixed solvent of isopropyl alcohol and water (25/75 (weight ratio)).

Comparative Example 8 A hard coat film was obtained in the same manner as in Comparative Example 6, except that the polyester resin was changed to the following polyester resin in the coating liquid for forming a laminated film of Comparative Example 6. Table 2 shows the results.

Polyester resin-Acid component 84% by mole of terephthalic acid 16% by mole of 5-sodium sulfoisophthalic acid-Diol component 94% by mole of ethylene glycol 6% by mole of diethylene glycol Polyester resin composed of the above acid component and diol component (Tg: 72 ° C) Water dispersion.

Comparative Example 9 Comparative Example 8 was repeated except that the following coating liquid was used as a crosslinking agent in the laminated film forming coating liquid of Comparative Example 8 at a polyester resin / crosslinking agent = 100/3 (weight ratio of solid content). A hard coat film was obtained in the same manner as described above. Table 2 shows the results.

Crosslinking agent: A coating solution obtained by diluting methylolated melamine in a mixed solvent of isopropyl alcohol and water (25/75 (weight ratio)).

Example 11 The same procedure as in Example 1 was carried out except that the laminated PET film obtained in Example 1 was pulverized and pelletized, and 20% by weight of polyethylene terephthalate was added thereto and melt-extruded. To obtain a hard coat film. Table 2 shows the results.

[0145]

[Table 1]

[Table 2]

[0146]

The hard coat film of the present invention uses a laminated polyester film having a specific Tg and having a laminated film mainly composed of two kinds of polyester resins having different Tg and a crosslinking agent. Thereby, the surface hardness is high, the abrasion resistance is excellent, and the adhesiveness of the hard coat layer is excellent, and at the same time, the effect of excellent adhesiveness is exhibited even after the treatment under wet heat.

Claims (7)

[Claims] 1. A laminate in which a hard coat layer is provided via a laminated film provided on at least one surface of a polyester film, wherein the laminated films have different glass transition points.
A polyester resin having a high glass transition point of 60 ° C. or higher and 110 ° C. or lower and a low glass transition point of a polyester resin containing, as main components, various kinds of polyester resins and a crosslinking agent (C). A hard coat film, wherein the glass transition point of the resin (B) is less than 60 ° C. 2. In the laminated film, the cross-linking agent (C) is used in a solid content weight ratio to a total of 100 parts by weight of the polyester resin (A) having a high glass transition point and the polyester resin (B) having a low glass transition point. The hard coat film according to claim 1, wherein the hard coat film is contained in an amount of 0.5 to 20 parts by weight. 3. The hard coat film according to claim 1, wherein a neopentyl glycol compound is contained as a diol component of the polyester resin (B) having a low glass transition point. 4. A hard coat layer comprising at least one monomer having three or more (meth) acryloyloxy groups in one molecule and one or two ethylenically unsaturated double bonds in one molecule. 4. An actinic ray-cured product comprising an actinic ray-curable monomer mixture comprising at least one kind of a monomer having a bond as a main component. Hard coat film. 5. The polyester film according to claim 1, wherein the polyester film is a polyethylene terephthalate film or a polyethylene-2,6-naphthalate film.
The hard coat film according to claim 4. 6. The method according to claim 1, wherein a coating liquid for forming a multilayer film is applied to at least one surface of the polyester film before crystal orientation is completed, and then stretched and heat-treated in at least one direction. The hard coat film according to any one of claims 1 to 5. 7. A polyester film comprising a polyester resin, a melamine-based cross-linking agent, or at least one selected from the reaction products thereof in a total of 5 ppm or more.
The hard coat film according to any one of claims 1 to 6, comprising a composition containing less than 0% by weight.