JP2002309109A - Process for producing film with high surface hardness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a film with a high surface hardness, wherein a finely divided filler having a modified surface can be prepared without producing hard agglomerated particles in modifying the surface of a filler for highly filling it in a resin so that the prepared filler can be uniformly dispersed in a resin, with the result of giving a transparent film having a high surface hardness. SOLUTION: The process for producing a film with a high surface hardness comprises melting and kneading a filler and a resin, and then extruding the kneaded material, which involves a step of spraying a surface modifier on to the filler while the filler in a powder form is agitated and fluidized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high surface hardness film having an improved elastic modulus by including a filler in a resin. The film is extruded after melt-kneading the filler and the resin. The present invention relates to a method for producing a high surface hardness film that is produced including steps. More specifically, the present invention relates to a method for producing a transparent substrate used for a hard coat film or an optical function film having excellent scratch resistance and surface hardness. The film produced according to the present invention is used for a surface protection film having an optical function such as a display such as a CRT, an LCD, a PDP, and an FED, a touch panel, and glass.

[0002]

2. Description of the Related Art It is generally known that when a filler is filled in a resin, the resin becomes high in hardness, but it is difficult to introduce the filler into a resin having a high viscosity. Intensive research is being done to obtain Furthermore, in order to impart not only hardness due to high filling, but also transparency of resin,
There is a demand for finer and higher dispersion fillers. Until now, surface modification of fillers has been accomplished by dissolving the surface modifier in a solvent,
By mixing, dispersing, and drying the filler therein, the surface-modified filler was produced, but when dried, the surface-modified filler creates hard agglomerated particles, deteriorating the optical characteristics, and as a result, The haze in the film was getting worse.

[0003]

The problem to be solved by the present invention is that when the surface is modified in order to highly fill the resin into the resin, hard coagulated particles are not generated, and the finely divided surface is modified. In some cases, a filler can be prepared and uniformly dispersed in a resin, and as a result, a film having a high hardness and transparency and a high surface hardness can be obtained.

[0004]

The above objects have been attained by the following means. 1) In a method for producing a high surface hardness film which is extruded after melt-kneading a filler and a resin, the filler in a powder state is sprayed with a surface modifier while stirring and flowing the filler. A method for producing a high surface hardness film, comprising the steps of: 2) The method for producing a high surface hardness film according to 1), wherein the concentration of the surface modifier with respect to the filler is 1% by mass to 90% by mass. 3) The surface modifier is sprayed as a solution diluted in a solvent, and the concentration of the surface modifier in the solution is 1% by mass or more and 9% by mass or more.
The method for producing a high surface hardness film according to 1) or 2), which is 0% by mass or less. 4) The method for producing a high surface hardness film according to 3), wherein the solvent has a boiling point of 100 ° C. or lower. 5) The resin is a polyester resin 1) to 4).
The method for producing a high surface hardness film according to any one of the above. 6) The method for producing a high surface hardness film according to any one of 1) to 5), wherein the filler is inorganic or organic fine particles. 7) The method for producing a high surface hardness film according to any one of 1) to 6), wherein the filler has a particle size of 1 nm or more and 400 nm or less. 8) The method for producing a high surface hardness film according to any one of 1) to 7), wherein the refractive index of the filler is the same as that of the resin, or the difference in the refractive index is 0.5 or less. 9) The method for producing a high surface hardness film according to any one of 1) to 8), wherein the resin contains a filler in an amount of 5% by mass to 50% by mass. A specific means for solving the problem in the present invention is to melt and knead a filler and a resin, and then, in a method for producing a high surface hardness film to be extruded, stirring and flowing the filler in a powder state, And a step of spraying a modifier with the filler. By using this surface-modified filler, it has become possible to improve the uniform dispersibility of the filler, which was insufficient with the conventional method. As a result, a resin satisfying a high surface height and optical characteristics can be obtained.

Hereinafter, the present invention will be described in detail. In the present invention, the concentration of the surface modifier with respect to the filler is preferably from 1% by mass to 90% by mass. 1 mass%
If it is smaller, the wettability with the resin is poor, and good dispersibility cannot be obtained. On the other hand, if it is more than 90% by mass, the fillers are remarkably aggregated with each other, which is not preferable.

In the present invention, the surface modifier is preferably diluted with a solvent and used as a solution in the spraying treatment. In this case, the concentration of the surface modifier in the solution is 1% by mass to 90% by mass. The following is preferred. In order to reduce the aggregation of the filler during drying, the addition of a solvent may be mentioned, but the above concentration is preferred from the viewpoint of viscosity and the like.

In the present invention, the boiling point of the solvent to be added to the surface modifier is 100 to reduce the aggregation of the filler during drying.
C. or lower, more preferably 40 to 90C. Examples of the solvent used in the present invention include ethers such as diisopropyl ether (boiling point 68.5 ° C.), dimethoxymethane (42.3 ° C.), and dimethoxyethane (85.2 ° C.). In addition, acetone (56.
Ketones such as methyl ethyl ketone (79.6 ° C.), cyclohexane (80.7 ° C.), and hexane (69
Hydrocarbons such as benzene (80.1 ° C), methanol (64.7 ° C), and ethanol (78.3).
C), 2-propanol (82.4C), and t-butanol (82.5C). These may be used in combination of two or more of them having good compatibility.

The resins used in the present invention include polyesters such as polyethylene terephthalate, polyethylene naphthalate, copolymers of polyethylene terephthalate and polyethylene naphthalate, polybutylene terephthalate, and mixtures thereof, polycarbonates, norbornene resins (cyclic olefin copolymers). ), Cellulose resins such as triacetyl cellulose and diacetyl cellulose, polyarylate, polymethyl methacrylate, and the like. Of these, polyethylene terephthalate is preferred for use as a film.

As the filler used in the present invention, silica,
Examples include inorganic fine particles such as alumina, titania, zirconia, mica, talc, calcium carbonate, barium sulfate, zinc oxide, magnesium oxide, calcium sulfate, kaolin and clay, and organic fine particles such as cross-linked polystyrene and cross-linked polyacrylate ester resin. . More preferred are silica, alumina, titania, zirconia, mica, talc and clay. The shape may be any of an irregular shape, a plate shape, a spherical shape, and a needle shape, and two or more kinds of fine particles may be mixed and used. Among these, inorganic fine particles having a Moh's hardness of 6 or more, such as silica, alumina, titania, and zirconia, are preferable.

The object of the present invention is to uniformly disperse an extremely small filler at a high concentration, and the particle diameter of the filler is preferably 1 nm or more and 400 nm or less. More preferably, it is 5 nm or more and 200 nm or less, and further preferably, 5 nm or more and 100 nm or less. Although it depends on the type of the filler having a particle diameter of 1 nm or less, dispersion is difficult and agglomerated particles are easily formed, and when the diameter is 400 nm or more, the haze tends to increase, and both tend to decrease transparency,
The above range is preferred.

[0011] The amount of the filler added is 5% by mass or more.
0 mass% or less is preferable. 7 mass% or more and 40 mass% or less, more preferably 10 mass% or more and 30 mass% or less. The added volume of the filler varies depending on the density (true specific gravity) of the filler.
Preferably at least 50% by volume, more preferably at least 3% by volume
The content is preferably at least 30% by volume.

In the present invention, it is desirable that the difference in the refractive index between the filler and the resin is smaller. The refractive index of the filler is the same as that of the resin, or the difference in the refractive index of the resin is 0.5 or less, more preferably 0 or less. .3 or less.

In order to disperse the filler uniformly in the resin,
It is preferable that the wettability with the resin is good, and it is preferable that the surface is modified.

In general, inorganic fine particles have a poor affinity for a binder polymer, so that the interface is easily broken by simply mixing the two, and it is difficult to improve the breaking strength. In order to improve the affinity between the inorganic fine particles and the polymer binder, it is preferable that the surface modifier forms a bond with the inorganic fine particles on the one hand and has a high affinity for the resin on the other hand.

Representative examples of these surface modifiers are listed below. 1) a silane coupling agent _{H 2 C = C (CH 3} ) COOC 3 H 6 Si (OCH 3)
₃ , H ₂ C = CHCOOC ₃ H ₆ Si (OCH ₃ ) ₃ ,
CH ₂ —CHCH ₂ OC ₃ H ₆ Si (OCH ₃ ) ₃ , ＼O / (glycidyl group) ClCH ₂ CH ₂ C ₃ H ₆ Si (OCH ₃ ) ₃ , ClC
H ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , R (OCH ₂ C
H ₂ ) _n OC ₃ H ₆ Si (OCH ₃ ) ₃ , R (OCH ₂
CH (CH ₃ )) _n OC ₃ H ₆ Si (OCH ₃ ) ₃ , R
OCO (CH ₂ ) _n Si (OCH ₃ ) ₃ (R represents a carbon atom of 1
To 18 alkyl groups, alkenyl groups, substituted alkyl groups, etc., n = 1 to 12), CH ₃ COCH ₂ COOC ₃ H
₆ Si (OCH ₃ ) ₃ , HSCH ₂ CH ₂ CH ₂ C ₃ H
₆ Si (OCH ₃ ) ₃ , (CH ₃ CH ₂ O) ₃ POC ₃
H ₆ Si (OCH ₂ CH ₃ ) ₃ 2) titanate-based coupling agent C ₁₇ H ₃₅ COOTi (OCH (CH ₃ ) ₂ ) _{3 and the} like (specifically, Planact (KRTT manufactured by Ajinomoto Co., Inc.)
S, KR46B, KR55, KR41B, KR38S,
KR138S, KR238S, 338X, KR44, K
R9SA)) 3) aluminum coupling agent PLENACT AL-M (Ajinomoto Co., Ltd.) and the like 4) unsaturated carboxylic acid _{(C n H 2n + 1 COOH} ) CH 3 COOH, etc. C ₂ H 5 COOH 5) unsaturated carboxylic acid oleate, etc. 6) hydroxycarboxylic acids citric acid, tartaric acid, etc. 7) dibasic acids oxalic acid, malonic acid, etc. 8) an aromatic carboxylic acid benzoic acid succinic 9) terminal carboxylic acid ester compound RCOO _{(C 5 H 10} COO) _n H, H ₂ C = CHCO
O (C ₅ H ₁₀ COO) _n H (R represents an alkyl group having 1 to 18 carbon atoms, an alkenyl group, a substituted alkyl group, and the like, and n represents 1, 2 or 3) 10) phosphoric acid monoester; Phosphodiester RCOOC ₂ H ₄ OCOC ₅ H ₁₀ OPO (OH) ₂ ,
(RCOOC ₂ H ₄ OCOC ₅ H ₁₀ O) ₂ POOH
(R is an alkyl group having 1 to 18 carbon atoms, an alkenyl group,
A substituted alkyl group, etc.) 11) Phosphonic acid, phenylphosphonic acid, etc. 12) Sulfuric acid monoester, sulfonic acid and sulfonic acid salt CH ₃ COOC ₂ H ₄ OSO ₃ H, benzenesulfonic acid, dodecylbenzenesulfonic acid, sodium dodecylbenzenesulfonic acid, 13) Polyoxyethylene aryl ether C ₁₂ H ₂₅ (OCH ₂ CH ₂ ) ₁₀ OH, C ₉ H ₁₉ , for example, sodium tri (isopropyl) naphthalene sulfonate
_{-C 6 H 4 - (OCH 2} CH 2) 12 OH, polyoxyethylene (polymerization degree 20) sorbitan monolaurate, etc. 14) polyoxyethylene derivatives, polyoxyethylene alkyl ethers, polyoxyethylene aryl esters, polyoxyethylene alkyl Esters, etc.

The surface of these fillers is modified by spraying with a spray nozzle or the like while uniformly stirring and flowing with a mixer.
A method of drying, a method of spraying and drying a processing liquid with a spray nozzle or the like while flowing a filler in a fluidized bed, a method of supplying a powder to be processed and a processing liquid into an air stream, and a method of supplying a powder and a processing liquid by an air stream. And pulverizing and dispersing the particles while colliding the powder particles with the processing liquid particles. Among these methods, a method of spraying and drying with a spray nozzle or the like while uniformly stirring and flowing with a mixer is more preferable. As a surface modification method, Mitsui Mining Co., Ltd.
It is preferable to carry out the treatment while stirring with a mixer such as a Henschel mixer manufactured by Kawata Corporation, a super mixer manufactured by Kawata Corporation, an axial mixer manufactured by Sugiyama Heavy Industries, Ltd., or a paddle mixer, and spraying the surface modifier. Any one of a one-fluid nozzle and a two-fluid nozzle can be used, but one that can make droplets finer is preferable. After the surface modification, a heat treatment can be performed, if necessary, to promote the reaction with the inorganic surface or to promote the formation of fine particles of the filler. Specifically, the surface modifier is diluted and adjusted to a desired concentration. After that, in the Henschel mixer, the non-surface-modified filler is fluidized, and the concentration-adjusted surface-modifier is sprayed onto the non-surface-modified filler,
It is highly preferred to obtain a surface-modified filler that dries quickly and does not generate hard agglomerated particles. Spray nozzles are widely used for reaction, granulation, cleaning in the chemical industry, humidity control, humidification in the food and printing industries, disinfection, cleaning and sterilization in medicine and pharmaceuticals. The spray shape includes a fan shape, a filled cone, an empty cone nozzle and the like, and a fan shape and a filled cone nozzle are preferable. On the other hand, surface modification in a solution using an ultrasonic wave, a stirrer, or a sand grinder is widely and generally performed, but is not preferable because coarse particles are generated by secondary aggregation during drying.

The surface-modified filler may be subjected to secondary agglomeration and may be pulverized. Therefore, it is preferable that the filler be pulverized by a method such as an air-flow pulverizer such as a jet mill or a ball mill.
Further, the coarse particles after crushing are preferably subjected to classification and separation sieving using an airflow classifier, a vibration sieving device, or the like.

The melt kneading of the resin and the filler is performed by a kneader, a single screw kneading extruder, a twin screw kneading extruder, a stone mill kneading extruder, a rotor type twin screw kneader,
A roll mill, a taper mill, or the like can be used.

It is preferable to mix the resin and the filler in advance. Specific methods of mixing include Henschel mixer, ribbon mixer, paddle mixer, V
Anything that can be dry-mixed, such as a mold mixer, a W mixer, or a shaker mixer, may be used. If the resin is polyethylene terephthalate, pellet the pellets at 100 ° C or higher and 25
0 ° C. or less, more preferably 130 ° C. or more and 200 ° C. or less, and 5 minutes or more and 5 hours or less, more preferably 10 minutes or more and 1 hour or less.
It is preferable to dry for not more than an hour.

The kneading temperature is preferably in the range of the temperature at which the resin softens and melts. If the temperature is too high, the surface modifier of the resin or the filler may be thermally decomposed, which is not preferable. For example, in the case of polyethylene terephthalate, the temperature is 200 ° C. or more and 350 ° C. or less, more preferably 23 ° C. or less.
The temperature is preferably from 0 ° C to 320 ° C, more preferably from 260 ° C to 300 ° C.

The kneading time is from 1 minute to 100 minutes,
More preferably, it is 2 minutes or more and 50 minutes or less, and still more preferably 3 minutes or more and 30 minutes or less. When kneading with various kneaders, it is preferable to perform kneading in an inert gas atmosphere or under reduced pressure or vacuum in order to prevent oxidation or thermal decomposition of the resin or the surface modifier of the filler. As the inert gas, nitrogen gas is preferable.

It is also possible to mix the resin and the filler at a high concentration, and further dilute the filler to a predetermined concentration while adding the resin. Examples of the dilution method include a single-screw extruder, a twin-screw extruder, a twin-screw kneading extruder, a Banbury mixer, a roll mill, and a taper mill. It is also preferable to combine dilution and additional kneading.

The composite resin obtained by kneading and mixing the filler can be injection-molded using an extruder, formed into a sheet through a die, or further stretched into a film.

The resin containing a filler in the present invention is used in the form of a sheet or a film. These may be formed in a single layer, but can also be used in a laminate. When making such a laminate, the components are laminated by a feed block method or a multi-manifold die method, and extruded into a sheet shape from the die. This is 4
It can be solidified on a casting drum of 0 ° C to 100 ° C to produce an unstretched film. A resin layer containing a filler (layer B) is a resin layer containing less filler than the layer B
(B / A) may be laminated on one side of (A layer), and a resin layer (B ′ layer) having less filler content than B layer is laminated on A layer on the opposite side of B layer (B / A / B). ') You can.

In the case of polyester terephthalate, it is preferable to further stretch after preparing an unstretched film. Improves the flatness of the film by increasing the adhesion to the casting drum by using an electrostatic application method or a water film formation method (to improve the adhesion between the melt and the drum by applying a fluid such as water on the casting drum). It is preferable. This is peeled off to form an unstretched sheet. Next, the unstretched sheet is stretched in the machine direction (MD). The preferred stretching ratio is 2.5 times or more and 4 times or less, more preferably 3 times or more and 4 times or less. The stretching temperature is preferably from 70 ° C to 160 ° C, more preferably from 80 ° C to 150 ° C, and even more preferably from 80 ° C to 140 ° C. The preferred stretching speed is 10% / sec or more and 300% / sec or less, more preferably 30% / sec or more and 250% / sec, and further preferably 50% / sec.
/ Sec or more and 200% / sec or less. Such MD stretching can be performed by transporting between a pair of rolls having different peripheral speeds. After stretching in the longitudinal direction, the film is stretched in the width direction (TD). The stretching ratio in the width direction is preferably 2.5 times or more and 5 times or less, more preferably 3 times or more and 4.5 times or less, and even more preferably 3.3 times or more and 4.3 times or less. Stretching temperature is 7
The temperature is preferably from 5 ° C to 165 ° C, more preferably 80 ° C or less.
℃ to 160 ° C, more preferably 85 ° C to 155
It is below ° C. The preferred stretching speed is 10% / second or more and 30% or more.
0% / sec or less, more preferably 30% / sec or more and 250%
/ Sec, more preferably 50% / sec or more and 200% / sec or less. TD stretching can be achieved by chucking both ends of the film, transporting the film into a tenter, and increasing the width. After stretching, the film is preferably heat-set. The heat setting temperature is 190 ° C to 275 ° C, more preferably 210 ° C to 270 ° C, and further preferably 230 ° C.
Or more and 270 ° C. or less, and a preferable treatment time is 5 seconds or more and 180 seconds or less, more preferably 10 seconds or more and 120 seconds or less, and further preferably 15 seconds or more and 60 seconds or less. It is preferable to relax in the width direction between 0% and 10% during heat setting. It is more preferably 0% or more and 8% or less, and further preferably 0% or more and 6% or less. Such heat setting and relaxation can be achieved by chucking both ends of the film, transferring the film to the heat setting zone, and reducing the width thereof. The trimming of the film end is also performed.

As a preferred mode of use, a film form is preferred. The thickness of the film is 50 μm or more and 30
It is preferably 0 μm or less, more preferably 80 μm or more and 260 μm or less. In the case of a laminated film, the thickness of the B layer and the B ′ layer is preferably 5 μm or more and 100 μm or less, more preferably 15 μm or more and 80 μm or less, and further preferably 2 μm or less.
It is 0 μm or more and 60 μm or less.

The film of the present invention is preferably subjected to a surface treatment in order to improve the adhesion when providing the functional layer. Surface treatments include UV treatment, corona discharge treatment, glow discharge treatment, flame treatment, high frequency treatment, active plasma treatment, laser treatment, mechanical treatment, mixed acid treatment, ozone oxidation treatment and other surface activation treatments. Among the surface treatments, ultraviolet irradiation treatment, corona treatment, glow treatment, and flame treatment are preferable.

A film using a resin containing a filler may be provided with at least one undercoat layer. The structure of the undercoat layer used in the present invention has been devised in various ways. It is sufficient to provide only a layer that adheres well to the substrate as a single layer, and two or more constituent layers are further provided thereon. There is a so-called multilayer method in which a resin layer is applied. In the single layer method or the multilayer method, a resin layer containing both a hydrophobic group and a hydrophilic group may be applied.

The material which can be used for the undercoat layer is not particularly limited. For example, vinyl chloride, vinylidene chloride, butadiene, methacrylic acid, acrylic acid, itaconic acid, maleic anhydride, vinyl acetate, acrylonitrile, (meth) acrylic ester, styrene Examples thereof include a copolymer using a monomer selected from the above as a starting material, a hydroxyl group-containing resin such as polyvinyl alcohol and polyvinyl butyral, and a halogenated synthetic resin such as chlorinated polyethylene.

The film of the present invention can have known functions such as a hard coat layer, an antireflection layer, an antiglare layer, a selective absorption layer, an ultraviolet absorption layer, an infrared absorption layer, a conductive layer and an adhesive layer. It can be used as a functional film having a feature that the surface hardness is hard. In particular, it is suitable for use as a high-hardness functional film having a hard coat layer and an optically functional thin film such as an antireflection layer on the hard coat layer.

[0031]

The present invention will be further described below with reference to examples in which the resin is polyethylene terephthalate, but the present invention is not limited thereto. (Example 1) (1) Preparation of polyethylene terephthalate (PET) resin 80 parts of dimethyl terephthalate, 58 parts of ethylene glycol, 0.029 part of manganese acetate tetrahydrate, and 0.028 part of antimony trioxide were added and stirred. While 200
Heated to ° C. 235 while removing by-product methanol
The temperature was raised to ° C. After the by-product of methanol was completed, 0.03 part of trimethyl phosphoric acid was added, and the pressure was reduced to 0.3 Torr while the temperature was raised to 285 ° C. to polymerize PET having an intrinsic viscosity of 0.62. Then, it was melt-extruded into noodles and cut with a cutter to obtain polyethylene terephthalate pellets, which were further pulverized (R-1). The produced polyethylene terephthalate was vacuum-dried at 130 ° C. for 1 hour. The refractive index was 1.66. In addition, the intrinsic viscosity was measured by the following method. Polyethylene terephthalate was dissolved in a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio: 60/40), and 0.2 g / dl, 0.6 g / dl,
Make a solution of 1.0 g / dl. This is measured at 20 ° C. using an Ubbelohde viscometer. The viscosity is plotted against the concentration, and the viscosity extrapolated to the concentration = 0 is defined as the intrinsic viscosity.

2. NK ESTER CB-1 manufactured by Shin-Nakamura Chemical Co., Ltd.
0.05 kg was dissolved in 0.15 kg of acetone to prepare a surface modification liquid. 0.5 kg of aluminum oxide C manufactured by Nippon Aerosil Co., Ltd. as a filler was weighed and charged into a Henschel mixer FM20 C / I manufactured by Mitsui Mining Co., Ltd. The Y0 blade was used for the upper blade, and the S0 blade was used for the lower blade. Henschel mixer rotation speed 1170rpm
, And while the aluminum oxide C is being well stirred and fluidized, the surface reforming liquid is applied to the flowing aluminum oxide C at a pressure of 4 kg / cm ² for 5 minutes using a nozzle 1/4 MKB60063S303W manufactured by Ikeuchi Co., Ltd. Spraying,
Stirring and mixing were performed. After that, the rotation speed was adjusted to 640 rpm, the temperature was set to 110 ° C., and after drying for 12 minutes, a desired surface-modified filler was obtained. Repeating the above, 2
kg of the surface-modified filler (P-1) was obtained. The refractive index is 1.
70.

3. Kneading of filler and polyethylene terephthalate The above dried polyethylene terephthalate pellets (R
-1) 9 kg of the surface-treated filler (P-1) was mixed with 1 kg of the surface-treated filler (P-1) using a Henschel mixer, followed by kneading and mixing using Kneedex manufactured by Mitsui Mining Co., Ltd. (R-2). The kneading was performed at a roll rotation speed of 50 rpm before the roll and 4 rolls after the roll.
0 rpm, set temperature of each zone Front roll input side 27
0 ° C, take-out side 260 ° C, post-roll input side 200
C., 210 ° C. on the take-out side, and a processing speed of 11 kg / hr.

4. Film formation of high surface hardness film
The resin (R-2) dried under reduced pressure for 1 hour and the resin (R-1) containing no filler were melted at 300 ° C. using different extruders, respectively, filtered through a 5 μm mesh filter, and then laminated. A film was prepared by extruding a T-die (multi-manifold die) having the above on a casting drum to which static electricity of 50 ° C. was applied so that the R-2 (filler-containing resin) side came into contact therewith.

This was subjected to MD stretching (3.5 times magnification, 105 times
° C), TD stretching (4.0 times, 110 ° C), heat setting (24
(5 ° C.) and thermal relaxation to prepare a film (F-1). The total film thickness is 175 μm, and the R-1 and R-2 layers are 125 μm (A) and 50 μm (B), respectively.

5. Corona treatment Corona discharge treatment is performed using a solid surface corona treatment machine 6KVA model manufactured by Pillar Co., Ltd., and a high surface hardness film (F-
1) was processed at 20 m / min. At this time, the processing is 0.3
The treatment was performed at 75 KV · A · min / m ² . The discharge frequency during the treatment was 9.6 KHz, and the gap clearance between the electrode and the dielectric roll was 1.6 mm.

6. Preparation and Application of Undercoat Liquid An undercoat liquid for imparting adhesion between the corona-treated high surface hardness film and the hard coat layer was prepared and applied using the following materials. UV3300B (Nippon Synthetic Chemical Industry Co., Ltd. terminal acrylic-modified urethane oligomer) 5 parts by weight _{p-C 9 H 19 -C 6} H 4 - (OCH 2 CH 2) 12 OH 0.05 parts by weight of toluene / methyl acetate (1 / 1) 94.95 parts by mass These undercoat liquids were mixed at 7 ml / m using a bar coater.
² was applied to the R-2 (filler-containing layer) side, and heated and dried at 160 ° C. for 5 minutes in a heating zone while being transported. Immediately before the winding, the film was cooled to 30 ° C. or lower with a cooling roller, and the prepared undercoated high surface hardness film was wound.

7. Preparation of Hard Coat Layer Coating Solution and Preparation of Hard Coat Layer As described below, a hard coat layer coating solution containing inorganic particles is prepared, subjected to coating, drying, and ultraviolet curing, and is subjected to R-2 (filler-containing layer) side. To form a hard coat layer. 7-1 Preparation of Inorganic Particle Dispersion (M-1) Methyl Isobutyl Ketone 234 g Aronix M5300 (oligoester acrylate polymer manufactured by Toagosei Co., Ltd.) 36 g AKP-G015 (Alumina manufactured by Sumitomo Chemical Co., Ltd.) 180 g Mixed solution of the above Mill with ceramic coating (1/4
G was finely dispersed at 1600 rpm for 10 hours using a sand mill and a medium of 1 mmφ zirconia beads.

7-2 Preparation of Coating Solution for Hard Coat Layer M-1 Dispersion 3 containing 40% by mass of alumina fine particles
63 g of methanol and 124 g of isopropanol
280 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) was added to and dissolved in the mixed solution to which g and 113 g of butyl acetate were added. Further, 16.8 g of a photopolymerization initiator (Irgacure 184, manufactured by Ciba Geigy) and 300 g of methyl isobutyl ketone were added to the obtained solution. After stirring the mixture for 30 minutes, the mixture was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a hard coat layer.

7-3 Preparation of Hard Coat Film On a hard resin film (F-1) provided with an undercoat layer, a hard coat coating solution prepared in 7-2 using a bar coater was applied on the surface of the resin film (F-1). A hard coat layer was prepared by applying and drying to 12 μm and irradiating with ultraviolet rays.

(Examples 2 to 6, and Comparative Example 1) Films were prepared by using the fillers shown in Table 1 and performing the same operations as in the examples. (Comparative Example 2) Aronix M5300 manufactured by Toagosei Co., Ltd.
0.4 kg was dissolved in 5 kg of methyl ethyl ketone, and alumina (aluminum oxide C, Nippon Aerosil Co., Ltd.)
Was mixed with a planetary mixer, and then dispersed using a horizontal sand mill (media: zirconia beads having a diameter of 1 mm). The dispersion was dried with a spray drier to prepare a surface-modified filler (P-1 ′). Except for the surface modification of the filler, the same operation as in Example 1 was performed to prepare a film.

[0042]

[Table 1]

In each of the examples, the characteristics of the produced films and hard coat films were evaluated as follows.

(1) Measurement of Film Surface Elastic Modulus The surface elastic modulus in the present invention is the value of the elastic modulus obtained by using a micro surface hardness meter (Fisher Instruments H100VP-HCU, manufactured by Fisher Instruments Co., Ltd.). . Specifically, a diamond pyramid indenter (tip-to-face angle: 136 °) was used to measure the indentation depth under a test load, and the test load was applied to the geometric shape of the indenter generated by the test load. It is a value obtained from the universal hardness divided by the surface area of the indentation calculated from the above, and is a value at an indentation depth of 1 μm.

(2) The transmittance of the film was measured using a haze haze meter (Model 1001DP, manufactured by Nippon Denshoku Industries Co., Ltd.).

(3) Pencil hardness test of film The hardness of the pencil scratch test is defined by JIS-S-6006 after conditioning the prepared hard coat film at a temperature of 25 ° C and a relative humidity of 60% for 2 hours. Using a pencil for test, in accordance with the pencil hardness evaluation method defined by JIS-K-5400, the value of the hardness of a pencil that does not show scratches under a load of 1 kg.

[0047]

As can be seen from the table, in the production method comprising a step of spraying and drying a surface modifier on the filler by a spray nozzle or the like while uniformly stirring and flowing the filler of the present invention with a mixer. It is clear that the produced film has a high surface hardness without deteriorating optical characteristics such as transmittance, and that the film provided with the hard coat layer has an excellent surface hardness.

[Brief description of the drawings]

FIG. 1 is an example of a preferred configuration of a high surface hardness film and a functional film according to one embodiment of the present invention.

[Explanation of symbols]

 1. Functional layer 2. Hard coat layer 3. Filler-containing layer Filler-free layer 5. Adhesive layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akihiro Matsufuji 210 Nakamura, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Photo Film Co., Ltd. (72) Inventor Tadahiro Kegasawa 200 Onakazato, Fujinomiya City, Shizuoka Prefecture Fuji Photo Film Co., Ltd. (Reference) 4F071 AA01 AA43 AA46 AB01 AB18 AB26 AD02 AD06 AE17 AF20 AF25 AF30 AF31Y AH12 BA01 BB06 BB08 BC01 4J002 AB021 BC032 BG022 BG061 BK001 CF061 CF071 CF081 CF161 CG001 DE076 DE096 DE106 DG001 016 DG001 FB166 FB232 FB236 FB262 FB266 GQ00

Claims (9)

[Claims] 1. A method for producing a high surface hardness film which is extruded after melt-kneading a filler and a resin, wherein a surface modifier is added to the filler while stirring and flowing the filler in a powder state. A method for producing a high surface hardness film, comprising a step of spraying. 2. The method according to claim 1, wherein the concentration of the surface modifier to the filler is 1
The method for producing a high surface hardness film according to claim 1, wherein the content is at least 90 mass%. 3. The method according to claim 1, wherein the surface modifier is sprayed as a solution diluted with a solvent, and the concentration of the surface modifier in the solution is 1% by mass to 90% by mass. Method for producing high surface hardness film. 4. The method for producing a high surface hardness film according to claim 3, wherein the solvent has a boiling point of 100 ° C. or lower. 5. The method for producing a high surface hardness film according to claim 1, wherein the resin is a polyester resin. 6. The method for producing a high surface hardness film according to claim 1, wherein the filler is inorganic or organic fine particles. 7. The filler has a particle diameter of 1 nm or more and 400 n.
The method for producing a high surface hardness film according to any one of claims 1 to 6, wherein the thickness is not more than m. 8. The method for producing a high surface hardness film according to claim 1, wherein the refractive index of the filler is the same as that of the resin, or the difference in the refractive index is 0.5 or less. 9. The method for producing a high surface hardness film according to claim 1, wherein the resin contains a filler in an amount of 5% by mass or more and 50% by mass or less.