JP2003138027A - Film having high surface hardness and its production process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film having a high surface hardness and excellent in transparency. SOLUTION: In the process for producing a film having a high surface hardness, including the steps of forming a layer containing a filler through a step of melting and kneading the filler and a resin and an extrusion step, the resin is used for the melting and kneading step after grinding. In the film with a high surface hardness, having a hard coat layer laminated on a filled layer prepared by melting and kneading a filler and a resin and extruding the kneaded material, the resin used for the melting and kneading comprises a ground resin.

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 a hard coat layer formed on a filler-containing layer having an improved elastic modulus by containing a filler in a resin. The containing layer relates to a high surface hardness film produced by a process including melt-kneading a filler and a resin and extruding. Further, it relates to a method for producing a high surface hardness film used for a hard coat film or an optical functional film having excellent scratch resistance and surface hardness, particularly, a step of melt-kneading a filler and a resin, and extrusion. The present invention relates to a method for producing a high surface hardness film having a filler-containing layer formed by a molding process. The film produced by the present invention is a CRT, L
It can be used for a display such as CD, PDP, FED, etc., a touch panel, a surface protective film having an optical function such as glass.

[0002]

2. Description of the Related Art It is generally known that when a resin is filled with a filler, the hardness becomes high, but it is difficult to introduce the filler into a high-viscosity resin, and the kneading property is improved. Earnestly research is done to obtain. Furthermore, when attempting to use it as a film having an optical function, it is necessary to impart transparency to the resin as well as the hardness due to high filling, and for that reason, high dispersion of the filler is required. ing. Up to now, the method of introducing the filler into the resin includes a method of melting the pelletized resin and filling the filler into the resin, but the melting at the time of kneading is slow, and therefore the filler is hard and coarse. Particles were formed, the dispersibility of the filler was poor, the optical characteristics were deteriorated, and as a result, the haze in the film was deteriorated. As an example of filling a resin with a filler, for example, Japanese Patent Application Laid-Open No. 6-155674 proposes a method of filling the resin with fine particles to diffuse the light and increase the translucency. The purpose of filling the fine particles is to diffuse light, and it is not a method for realizing a film having improved visibility and transparency. On the other hand, as a film having a high surface hardness, a film in which a hard coat layer is provided on a base made of a resin is generally known at present, but when a pencil hardness test, which is an index of surface hardness, is performed, Although the layer itself has sufficient hardness and does not change, the base itself plastically deforms and becomes a scratch, and it is difficult to say that the film as a whole has sufficient surface hardness.

[0003]

Kneading a resin and a filler,
In extrusion, when the desired filler concentration, uniformity is to be obtained, sufficient kneadability with the above-mentioned pelletized resin,
It is difficult to obtain uniformity. The present invention aims to obtain good uniformity of the filler in kneading the resin and the filler, and to obtain a high surface hardness film having high elasticity, high surface hardness, and transparency. To do.

[0004]

The solution to the problems in the present invention is to use finely pulverized resin when melt-kneading the resin and the filler, specifically, by the following means.
To be achieved. That is, (1) in a method for producing a high surface hardness film including a step of forming a filler-containing layer in a step including a step of melt-kneading a filler and a resin, and a step of extrusion molding, crushing the resin A method for producing a high surface hardness film, which is used in the step of melt-kneading. (2) The method for producing a high surface hardness film according to (1), which comprises a step of laminating a hard coat layer on the filler-containing layer. (3) The size of the crushed resin is 0.003 m
m or more and 3 mm or less, The manufacturing method of the high surface hardness film as described in (1) or (2) characterized by the above-mentioned. (4) The method for producing a high surface hardness film according to any one of (1) to (3), wherein the resin is a polyester resin. (5) The method for producing a high surface hardness film according to any of (1) to (4), wherein the filler is inorganic or organic fine particles. (6) The method for producing a high surface hardness film according to (5), wherein the particle size of the filler is 1 nm or more and 400 nm or less. (7) The method for producing a high surface hardness film according to any one of (1) to (6), wherein the difference in refractive index between the filler and the resin is 0.5 or less. (8) The method for producing a high surface hardness film according to any one of (1) to (7), wherein the filler is contained in an amount of 5% by mass or more and 50% by mass or less with respect to the resin. (9) In a high surface hardness film in which a filler and a resin are melt-kneaded and a hard coat layer is laminated on a filler-containing layer produced by extrusion molding, the resin used in the melt-kneading is crushed. A high surface hardness film characterized by having (10) The size of the crushed resin is 0.003
The high surface hardness film according to (9), which is not less than 3 mm and not more than 3 mm. (11) The high surface hardness film according to (9) or (10), which has a haze of 8% or less. (12) The high surface hardness film according to any one of (9) to (11), which has a transmittance of 85% or more.

The high surface hardness film of the present invention comprises a filler-containing layer and a hard coat layer laminated thereon, and the filler-containing layer is formed by melt-kneading the filler and the resin and extruding. At this time, the resin used is pulverized. The crushed resin has a larger surface area than the pelletized resin, and the melting speed increases when kneading with the filler, which is preferable because the dispersibility of the filler is improved.
As a result, since the filler-containing layer itself has excellent optical properties and high surface hardness, it is possible to obtain a high surface hardness film satisfying high surface hardness and optical properties by further providing a hard coat layer. it can.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The present invention is described in detail below. First, as the resin used in the present invention, polyethylene terephthalate, polyethylene naphthalate, polyethylene terephthalate and polyethylene naphthalate copolymers, polybutylene terephthalate, polyesters such as mixtures thereof, polycarbonate, norbornene resins (cyclic olefin copolymers ), Cellulose resins such as triacetyl cellulose and diacetyl cellulose, polyarylate, polymethacrylic acid methyl ester and the like are preferable. Of these, polyethylene terephthalate is preferred for use as a film.

In forming the filler-containing layer in the present invention,
The resins listed above are finely crushed before use. It is preferable to dry the resin in advance, and heat drying, freeze-drying using dry ice, liquid nitrogen, or the like (freeze-drying) is used. As a means for crushing the resin, specifically, a crusher such as a centrifugal mill, an impeller mill, a hammer mill, a pin mill, a turbo mill, a Linrex mill or a freezer mill can be used. Usually, the pellet before crushing is larger than 3 mm and has a small surface area, so that the melting rate is slow. In order to increase the surface area and increase the melting rate, the size of the crushed resin is 0.003
mm or more and 3 mm or less, and more preferably 0.0
1 mm or more and 1 mm or less, more preferably 0.0
It is 5 mm or more and 0.5 mm or less.

The filler used in the present invention is silica,
Inorganic particles such as alumina, titania, zirconia, mica, talc, calcium carbonate, barium sulfate, zinc oxide, magnesium oxide, calcium sulfate, kaolin and clay, and organic particles such as crosslinked polystyrene and crosslinked polyacrylate ester resin. . More preferred are silica, alumina, titania, zirconia, mica, talc and clay. The shape may be any of an amorphous shape, a plate shape, a spherical shape, and a needle shape, and two or more kinds of fine particles may be mixed and used.

The present invention aims 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. It is more preferably 5 nm or more and 200 nm or less, and further preferably 5 nm or more and 100 nm or less. If the thickness is less than 1 nm, it is difficult to disperse and agglomerated particles are formed, and if the thickness is more than 400 nm, the haze becomes large, and both of them deteriorate the transparency of the film.

From the viewpoint of increasing the hardness of the film, the amount of the filler added is preferably 5% by mass or more and 50% by mass or less based on the resin. 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 from the viewpoint of hardness and transparency of the film,
The volume occupied by the filler is preferably 2% by volume or more and 50% by volume or less, more preferably 3% by volume or more and 30% by volume or less in the film.

The high surface hardness film of the present invention is transparent, and when used as an optical functional film, it is desirable that the difference in refractive index between the filler and the resin is small, and the refractive index between the filler and the resin is small. The difference in the refractive index is preferably 0.5 or less, more preferably 0.3 or less, further preferably 0.1 or less, and 0, that is, the filler and the resin have the same refractive index. Is particularly preferable.

Further, in the present invention, since the film has sufficient transparency, the transmittance of the film is preferably 85% or more, more preferably 87% or more and 98% or less, and further preferably 90%. It is above 95%.

To uniformly disperse the filler in the resin,
It preferably has good wettability with a resin and is preferably surface-modified. Generally, since the inorganic fine particles have a poor affinity with the binder polymer, it is difficult to improve the breaking strength by simply mixing the both, because the interface is easily broken. In order to improve the affinity between the inorganic fine particles and the polymer binder, the surface modifier preferably forms a bond with the inorganic fine particles on the one hand and has a high affinity with the resin on the other hand.

Typical examples of these surface modifiers include H₂
C = C (CH₃) COOC₃H₆Si (OCH₃)₃, H₂C
= CHCOOC₃H₆Si (OCH₃)₃, CH₂\ O /-
CHCH₂(Glycidyl group) OC₃H₆Si (OC
H₃)₃, ClCH₂CH₂C₃H₆Si (OCH₃)₃, Cl
CH₂CH₂CH₂Si (OCH₃)₃, R (OCH₂C
H₂) NOC₃H₆Si (OCH₃)₃, R (OCH₂CH
(CH₃)) NOC₃H₆Si (OCH ₃)₃, ROCO
(CH₂) NSi (OCH₃)₃(R is carbon number 1 to 18
N alkyl group, alkenyl group, substituted alkyl group, etc.
= 1 to 12), CH₃COCH₂COOC₃H₆Si (OC
H₃)₃, HSCH₂CH₂CH₂C₃H₆Si (OC
H₃)₃, (CH₃CH₂O)₃POC₃H₆Si (OCH₂C
H₃)₃Silane coupling agent such as C₁₇H₃₅COOT
i (OCH (CH₃)₂)₃Titanate represented by
-Based coupling agents (specifically Plane manufactured by Ajinomoto Co., Inc.)
Act (KRTTS, KR46B, KR55, KR41
B, KR38S, KR138S, KR238S, 338
X, KR44, KR9SA)), Planeact AL-M
Aluminum-based coupling resins such as those manufactured by Ajinomoto Co., Inc.
Agent, CH₃COOH, C₂H_FiveC such as COOH_nH_{2n + 1}C
Saturated carboxylic acid represented by OOH, oleic acid, etc.
Saturated carboxylic acid, citric acid, tartaric acid, etc.
Dibasic acid such as rubic acid, oxalic acid, malonic acid, succinic acid
Acids, aromatic carboxylic acids such as benzoic acid, RCOO (C_Five
H_TenCOO)_nH, H₂C = CHCOO (C_FiveH_TenCO
O)_nH (R is an alkyl group having 1 to 18 carbon atoms,
Nyl group, substituted alkyl group, etc., such as n = 1, 2, 3)
Terminal carboxylic acid ester compound, RCOOC₂H_FourOCO
C_FiveH_TenOPO (OH)₂, (RCOOC₂H_FourOCOC_Five
H_TenO)₂POOH (R is alkyl having 1 to 18 carbons
Groups, alkenyl groups, substituted alkyl groups, etc.)
Ester, phosphonic acid such as phenylphosphonic acid, CH
₃COOC₂H_FourOSO₃Sulfonic acid esters such as H,
Benzene sulfonic acid, dodecyl benzene sulfonic acid
Acid, sodium dodecylbenzene sulfonate, tri (iso
Propyl) Naphthalene Sulfonate and other sulfites
Acid, sulfonate, C₁₂H_{twenty five}(OCH₂CH₂)_Ten
OH, C₉H₁₉-C₆H_Four‐ (OCH₂CH₂)₁₂OH, PO
Li (degree of polymerization 20) Oxyethylene sorbitan monolauri
Polyoxyethylene arylate such as acid ester
Polyoxyethylene alkyl ether, polyoxy
Ethylene aryl ester, polyoxyethylene alk
And polyoxyethylene derivatives such as ruester
To be

The surface modification of these inorganic fine particles is preferably performed in a liquid layer or a solid layer. When modifying the surface with a liquid layer, add inorganic fine particles to the solution in which the surface modifier is dissolved, and use ultrasonic waves, stirrers, homogenizers, dissolvers, agitators, planetary mixers, paint shakers, sand grinders, kneaders, colloid mills, etc. It is preferable to use or to stir or disperse. The solution for dissolving the surface modifier is preferably an organic solvent having a large polarity, and specific examples thereof include known solvents such as alcohols, ketones and esters. After the surface modification, the organic solvent is preferably filtered or distilled off, and dried by a spray dryer or vacuum drying.

When the surface is modified with a solid layer, inorganic fine particles are used as a Henschel mixer, paddle mixer, V-type mixer, W
It can be carried out by a method of treating while adding a surface modifier while stirring with a mold mixer, shaker mixer or the like. After the surface modification, heat treatment can be carried out as necessary to promote the reaction with the inorganic surface.

The surface-treated fine particles may be secondary aggregated and may be crushed. Therefore, they may be crushed by a method such as an air flow type crusher such as a jet mill or a ball mill.

The melt-kneading of the filler and the resin may be carried out by adding them from different feeders at the time of melting without mixing them in advance, or by mixing them in advance and melt-kneading. . When the filler and the resin are mixed in advance, specific mixing means include Henschel mixer, ribbon mixer, paddle mixer, V-type mixer, and W mixer.
A mold mixer, a shaker mixer, etc. may be mentioned, and any device capable of dry mixing may be used. If the resin is polyethylene terephthalate, before mixing with the filler, 1
It is preferable to dry at 00 ° C. or more and 250 ° C. or less, more preferably 130 ° C. or more and 200 ° C. or less, 5 minutes or more and 5 hours or less, and more preferably 10 minutes or more and 1 hour or less.

Examples of the melt-kneading machine for the resin and the filler include a twin screw type kneading extruder, a stone mill type kneading extruder, a roll mill and a batch kneader. 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, 200 ° C or higher 35
0 ° C or lower, more preferably 230 ° C or higher and 320 ° C or lower,
More preferably, it is 260 ° C. or higher and 300 ° C. or lower.

The kneading time is from 1 minute to 100 minutes,
It is more preferably 2 minutes or more and 50 minutes or less, still more preferably 3 minutes or more and 30 minutes or less. When kneading with a twin-screw kneading extruder, it is preferable to carry out in an inert gas atmosphere in order to prevent the resin and the surface modifier of the filler from being oxidized or thermally decomposed. Nitrogen gas is preferable as the inert gas. A kneader, such as a roll mill, which can set the roll clearance smaller and can obtain high shear due to its effect is particularly preferable.

It is also preferable to melt-knead the filler-containing resin once melt-kneaded once in order to improve the dispersibility of the filler. It is also possible to mix the resin and the high-concentration filler and further dilute it to a predetermined filler concentration while adding the resin. As a diluting method, a single-screw extruder,
There are a twin-screw extruder, a twin-screw kneading extruder, a Banbury mixer, and the like. It is also preferable to combine the dilution and the additional kneading.

The composite resin prepared by kneading and mixing the fillers by melt-kneading is extruded using an extruder and injection-molded, or formed into a sheet through a die, and further stretched to form a film. Thus, the filler-containing layer is formed.

In the high surface hardness film of the present invention, the filler-containing layer made of the resin containing the filler may be formed as a single layer, but may be formed as a laminate. When making such a laminated body, each component is extruded using a T-die (multi-manifold die or the like) having a laminated structure. This can be solidified on a casting drum at 40 ° C to 100 ° C to prepare an unstretched film. Although the laminated structure is not particularly limited, for example, a resin layer (B layer) containing a filler may be used as a resin layer (A layer) containing less filler than the B layer.
(B / A) may be laminated on one side of the layer (B / A), and a resin layer (B ′ layer) having a smaller filler content than the B layer is laminated (B / A) on the side opposite to the B layer. / B '). However, the B and B ′ layers may be layers made of a resin containing no filler.

When polyethylene terephthalate is used as the resin, it is preferable to prepare an unstretched film and then further stretch it. The polyethylene terephthalate melt-kneaded and extruded from the die can be formed into a film on a casting drum to produce an unstretched sheet. At this time, first of all, the electrostatic application method, the water film forming method (coating a fluid such as water on the casting drum to improve the close contact between the melt and the drum) and the like are used to increase the close contact with the casting drum. Is preferable because it can improve the flatness. Next, the unstretched sheet is stretched in the machine direction (MD). Such MD stretching can be carried out by conveying between a pair of rolls having different peripheral speeds. The preferred draw 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 70 ° C or higher and 160 ° C or lower, more preferably 80 ° C or higher and 150 ° C or lower, and further preferably 80 ° C or higher and 140 ° C or lower. A 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 or more and 200% / sec or less. After stretching in the longitudinal direction, stretching in the width direction (TD) is performed. The TD stretching can be achieved by chucking both ends of the sheet and transporting the sheet into a tenter to widen the width. The draw 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 further preferably 3.3 times or more and 4.3 times or less. The stretching temperature is preferably 75 ° C or higher and 165 ° C or lower, more preferably 80 ° C or higher and 160 ° C or lower, and further preferably 85 ° C or higher and 155 ° C or lower. Preferred stretching speed is 1
0% / sec or more and 300% / sec or less, more preferably 30%
/ Sec or more and 250% / sec or more, more preferably 50% / sec or more and 200% / sec or less. After stretching, the film is preferably heat-fixed. The heat setting temperature is 190 ° C. or higher and 275 ° C. or lower, more preferably 210 ° C. or higher and 270 ° C. or lower, further preferably 230 ° C. or higher and 270 ° C. or lower, and the preferable treatment time is 5 seconds or longer and 180 seconds or shorter, and more preferably 10 seconds or longer. 120 seconds or less, more preferably 1
It is 5 seconds or more and 60 seconds or less. It is preferable to relax 0% or more and 10% or less in the width direction during heat setting. It is more preferably 0% or more and 8% or less, still more preferably 0% or more and 6% or less. Such heat setting and loosening can be achieved by chucking both ends of the sheet, conveying the sheet to the heat setting zone, and narrowing the width. Also trim the edges.

In the present invention, a hard coat layer is laminated on the unstretched sheet-shaped or stretched film-shaped filler-containing layer formed as described above to prepare a high surface hardness film. By providing the hard coat layer, excellent scratch resistance and high hardness can be imparted to the film, the pencil hardness of the film is increased, and high surface hardness can be realized. The pencil hardness is a value obtained by the pencil hardness evaluation method defined by JIS-K-5400 and is an index for measuring the surface hardness of the film. If the pencil hardness is 4H or more, it can be said that the film has a sufficient surface hardness,
It is preferably at least 5H. The filler and the resin are melt-kneaded by the production method of the present invention, and the filler-containing layer obtained by extrusion molding also has a high surface hardness, and plastic deformation as a base of the film with a hard coat layer is obtained. It can be hard to wake up. Further, it is possible to increase the hardness of the film by thickening the hard coat layer instead of kneading the filler with the resin. However, if the hard coat layer is thickened, the curl becomes large or the hard coat layer film itself There are problems such as becoming brittle. In the present invention, the hard coat layer can be made thin by kneading the resin with the filler and increasing the hardness of the resin layer itself, and the above problems can be avoided.

In the high surface hardness film of the present invention, a hard coat layer is provided on the filler-containing layer in order to increase the surface hardness. An active energy ray curable resin or the like is used as the hard coat material. Examples of the active energy ray curable resin include polyfunctional monomers, preferably active energy represented by polyfunctional acrylates or methacrylates (for example, pentaerythritol tetra (meth) acrylate and dipentaerythritol hexa (meth) acrylate). Ray-curable compounds are mentioned. It is preferable to add a polymerization initiator to these compounds, if necessary. Further, in order to increase hardness and scratch resistance in the hard coat layer, it is particularly effective to include a filler, for example, silica, alumina, fine particles of oxides such as zirconia and colloidal particles. You can The particle size of the fine particles as the filler is preferably 1 to 100 nm, and the addition amount thereof is preferably 5% by volume or more and 50% by volume or less of the curable resin. If it is 50% by volume or more, the film becomes brittle, and if it is too small, the effect of addition cannot be obtained. The thickness of the hard coat layer is preferably 2 to 50 μm, particularly preferably 4 to 30 μm. Further, if necessary, anionic, cationic or nonionic surfactants are added, or surface treatment such as corona treatment or glow treatment is performed to improve the hydrophilicity and adhesion of the hard coat surface,
The coatability of the conductive layer and the adhesion with the conductive layer can be enhanced.

The thickness of the high surface hardness film of the present invention is preferably 50 μm or more and 300 μm or less, more preferably 80 μm or more and 260 μm or less. Among these, the thickness of the hard coat layer is preferably 2 μm or more and 50 μm or less, and more preferably 4 μm or more and 30 μm or less. The thickness of the filler-containing layer is preferably 10 μm or more and 80 μm or less, more preferably 20 μm or more and 50 μm or less. When the filler-containing layer is a laminate, the thickness of the B layer and B'layer is 5
It is preferably from 100 μm to 100 μm, more preferably 15 μm
μm or more and 80 μm or less, more preferably 20 μm or more 6
It is 0 μm or less. The thickness of layer A is set to B, B '
Depending on the layer thickness, the total filler-containing layer thickness A + B + B '
Is 15 μm or more and 300 μm or less, and further 60 μm or more 1
The thickness is preferably set to 80 μm or less.

The high surface hardness film of the present invention may be provided with a functional layer, and in that case, it is preferable to carry out a surface treatment in order to improve the adhesion between the film and the functional layer. As the surface treatment, ultraviolet treatment, corona discharge treatment, glow discharge treatment, flame treatment, high frequency treatment, active plasma treatment,
There are surface activation treatments such as laser treatment, mechanical treatment, mixed acid treatment, and ozone oxidation treatment. Among these surface treatments, ultraviolet irradiation treatment, corona treatment, glow treatment, and flame treatment are preferable.

The high surface hardness film of the present invention may be provided with at least one undercoat layer. The constitution of the undercoat layer used in the present invention has been variously devised, and it is possible to provide only a layer that adheres well to the substrate as a single layer, and a so-called multi-layer method in which a resin layer that adheres further is applied Two or more constituent layers may be provided. In the single-layer method or the multi-layer method, it is more preferable to apply a resin layer containing both a hydrophobic group and a hydrophilic group.

The material that can be used for the undercoat layer is not particularly limited, but examples thereof include vinyl chloride, vinylidene chloride, butadiene, methacrylic acid, acrylic acid, itaconic acid, maleic anhydride, vinyl acetate, acrylonitrile, (meth) acrylic acid ester, and styrene. Examples thereof include copolymers using monomers selected from the above as starting materials, hydroxyl group-containing resins such as polyvinyl alcohol and polyvinyl butyral, and halogenated synthetic resins such as chlorinated polyethylene.

The high surface hardness film of the present invention can impart known functions such as 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 characteristic of having a hard surface. In particular, it is suitable for use as a high hardness functional film having an optical functional thin film such as an antireflection layer on the hard coat layer.

FIG. 1 shows a preferred constitutional example of the high surface hardness film and the functional film of the present invention. The so-called A / of the filler-containing layer (A layer) 1 and the non-filler-containing layer (B layer) 2
A high surface hardness film having a laminated structure of B, a hard coat layer 4 provided on the filler-containing layer 1, and an adhesive layer 3
And the functional layer 5 according to the function to be added is provided on the hard coat layer. The adhesive layer can increase the adhesion to the material to be protected.

[0033]

EXAMPLES 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 terephthalic acid dimethyl ester, 58 parts of ethylene glycol, 0.029 parts of manganese acetate tetrahydrate, 0.028 parts of antimony trioxide are added and stirred to 200
Heated to ° C. 235 while removing by-product methanol
The temperature was raised to ° C. After completion of the by-product of methanol, 0.03 part of trimethyl phosphoric acid was added, and the temperature was raised to 285 ° C. and the pressure was reduced to 0.3 Torr to polymerize PET having an intrinsic viscosity of 0.62. Then, the mixture was melt-extruded into noodles and cut with a cutter to obtain polyethylene terephthalate pellets of about 4 mm. The produced polyethylene terephthalate was vacuum dried at 130 ° C. for 1 hour. The intrinsic viscosity was measured by the following method. Phenol / 1,1,2,2-tetrachloroethane mixed solvent
Polyethylene terephthalate is dissolved in (weight ratio: 60/40) to prepare solutions of 0.2 g / dl, 0.6 g / dl and 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 concentration = 0 is taken as the intrinsic viscosity.

2. Pulverization of polyethylene terephthalate The polyethylene terephthalate resin obtained previously was pulverized using a CUM centrifugal mill CUM300 manufactured by Mitsui Mining Co., Ltd. (R-1). As the crushing conditions, the resin supply rate was 100 kg / hr, the clearance between the rotating disk and the fixed disk was 0.5 mm, the rotation speed of the rotating disk was 7,000 rpm, and the blower air rate for conveying the crushed resin was 1300 m ³ / hr. The average diameter of the obtained pulverized resin was about 300 μm.

3. Surface modification of filler Shin Nakamura Chemical Co., Ltd. NK ESTER CB-1 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., which is a filler, was weighed and charged into a Henschel mixer FM20 C / I manufactured by Mitsui Mining Co., Ltd. Y0 on the upper blade
The S0 blade was used as the blade and the lower blade. Henschel mixer rotation speed is set to 1170 rpm, aluminum oxide C is well agitated and fluidized while flowing aluminum oxide C Ikeuchi Co., Ltd. nozzle 1 / 4MKB60063S303
Using W, the surface modification liquid was sprayed, stirred, and mixed for 5 minutes at a pressure of 4 kg / cm ² . After that, the rotation speed is 640
After adjusting the rpm to 110 ° C. and drying for 12 minutes, a desired surface-modified filler was obtained. The above procedure was repeated to obtain 2 kg of the surface-modified filler (P-1).

3. Kneading of filler and polyethylene terephthalate The crushed polyethylene terephthalate (R-1) 9
kg and 1 kg of the surface-treated filler (P-1) were mixed by a Henschel mixer, and then kneaded and mixed using Kneedex manufactured by Mitsui Mining Co., Ltd. (R-2). In addition, kneading is
Roll rotation speed Front roll 50 rpm, Rear roll 40 rp
m, set temperature of each zone Front roll input side 270 ° C,
The conditions were 260 ° C. on the take-out side, 200 ° C. on the post-rolling side, 210 ° C. on the take-out side, and a processing rate of 11 kg / hr.

4. Formation of Filler-Containing Layer The filler-containing resin pellet prepared by the above method is heated to 130 ° C.
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 separate extruders, filtered through a 5 μm mesh filter, and then laminated. A film was prepared from a T-die (multi-manifold die) having a structure and extruded so that the R-2 (filler-containing resin) side hits a casting drum to which static electricity was applied at 50 ° C. This is MD stretched (ratio 3.
5 times, 105 ° C.), TD stretching (4.0 times, 110 ° C.),
Heat setting (245 ℃), heat relaxation is performed, and the filler containing layer (F
-1) was produced. The total thickness of the filler-containing layer is 175 μm, R
-1 and R-2 layers are 125 μm (A) and 50 μm, respectively
(B).

5. Corona treatment For the corona discharge treatment, a solid state corona treatment machine 6KVA model manufactured by Pillar Co. was used, and the filler-containing layer (F-1) was treated at 20 m / min. At this time, the processing is 0.375K
The treatment was V · 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 Using the following materials, an undercoat liquid for imparting adhesion between the corona-treated filler-containing layer and the hard coat layer was prepared and applied. - UV3300B (Nippon Synthetic Chemical Industry Co., Ltd. terminal acrylic-modified urethane oligomer) 5 parts by mass _{· C 9 H 19 -C 6 H} 4 - (OCH 2 CH 2) 12 OH 0.05 part by mass Toluene / methyl acetate (1 / 1) 94.95 parts by mass of these undercoat liquids, using a bar coater, 7 ml / m
^It was applied to the R-2 (filler-containing layer) side so as to be ² , and was heated and dried in a heating zone at 160 ° C. for 5 minutes while being conveyed. Immediately before winding, it was cooled to 30 ° C. or lower with a cooling roller, and the prepared filler-containing layer with an undercoat was wound up.

7. Preparation of Hard Coat Layer Coating Liquid and Preparation of Hard Coat Layer As described below, a hard coat layer coating liquid containing inorganic particles was prepared, and coating / drying / ultraviolet curing treatments were carried out on the R-2 (filler containing layer) side. A hard coat layer was formed on. 7-1 Preparation of Inorganic Particle Dispersion (M-1) -Methyl Isobutyl Ketone 234g-Aronix M5300 (Toagosei Co., Ltd. Oligoester Acrylate Polymer) 36g-AKP-G015 (Sumitomo Chemical Alumina) 180g The above mixture Ceramic-coated sand mill (1/4
The sand mill of G and the medium were 1 mmφ zirconia beads) and finely dispersed at 1600 rpm for 10 hours.

7-2 Preparation of coating liquid for hard coat layer M-1 dispersion 3 containing 40% by mass of alumina fine particles
To 00 g, methanol 63 g, isopropanol 124
g and 113 g of butyl acetate were added and dissolved in a mixture of 280 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.). 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. The mixture was stirred for 30 minutes and then filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for hard coat layer.

7-3 Preparation of High Surface Hardness Film (Hard Coat Film) On the filler-containing layer (F-1) provided with an undercoat layer, a hard coat prepared on 7-2 by using a bar coater on its surface. A coating solution was applied and dried so as to have a layer thickness of 12 μm, and was irradiated with ultraviolet rays to form a hard coat layer, thereby producing a high surface hardness film (hard coat film).

(Examples 2 to 6 and Comparative Example 1) Using the filler, addition amount, and filler-containing layer structure shown in Table 1, the same operation as in Example 1 was performed to prepare a film. (Example 7) Using the fillers, addition amounts, and filler-containing layer constitutions shown in Table 1, the same operations as in Example 1 were performed except for the step of forming a hard coat layer, to prepare a film. (Comparative Examples 2 and 3) Unmilled polyethylene terephthalate pellets were used in place of the pulverized polyethylene terephthalate, the filler, the addition amount, and the filler-containing layer structure shown in Table 1 were used, and the same operation as in Example 1 was performed. And made a film. (Comparative Example 4) Unmilled polyethylene terephthalate pellets were used, and they were directly subjected to melt film formation to prepare a film without providing an undercoat layer and a hard coat layer.

[0044]

[Table 1]

In each of the examples, the film characteristics were evaluated as follows.

(1) Measurement of Surface Elastic Modulus of Film The surface elastic modulus in the present invention is a value of elastic modulus obtained by using a fine surface hardness meter (Fischer Scope H100VP-HCU manufactured by Fisher Instruments Co., Ltd.). is there. Specifically, a diamond quadrangular pyramid indenter (tip facing angle; 136 °) is used to measure the indentation depth under a test load, and the test load is 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, and is the value when the indentation depth is 1 μm.

(2) Film transmittance was measured using a haze haze meter (1001DP type, manufactured by Nippon Denshoku Industries Co., Ltd.).

(3) Pencil hardness test of film The hardness of the pencil scratch test is specified by JIS-S-6006 after the prepared hard coat film is conditioned for 2 hours at a temperature of 25 ° C. and a relative humidity of 60%. It is the hardness value of a pencil in which no scratches are observed under a load of 1 kg according to the pencil hardness evaluation method defined in JIS-K-5400 using a test pencil.

From Table 1, the film prepared by using the filler-containing resin obtained by kneading the pulverized polyethylene terephthalate of the present invention and the filler has a high elastic modulus and an excellent surface without deteriorating the optical characteristics such as transmittance and haze. It is clear that it has hardness (pencil hardness). Further, it can be seen that the film obtained by the production method of the present invention has excellent optical characteristics and high surface hardness of the filler-containing resin itself.

[0050]

According to the present invention, good homogeneity of the filler can be obtained by melt-kneading the filler and the crushed resin, resulting in high surface hardness and transparency. And a high surface hardness film that can be used for optical functional films and the like, and a method for producing the same.

[Brief description of drawings]

FIG. 1 is an example of a preferable constitution of a high surface hardness film and a functional film of the present invention.

[Explanation of symbols]

1 Filler-containing layer 2 Non-filler containing layer 3 Adhesive layer 4 Hard coat layer 5 Functional layers

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B32B 27/20 B32B 27/20 Z 4F201 31/30 31/30 4J002 C08J 5/18 CER C08J 5/18 CER 7/04 7/04 K C08K 3/00 C08K 3/00 C08L 101/00 C08L 101/00 G02B 1/04 G02B 1/04 1/10 B29K 67:00 // B29K 67:00 105: 16 105: 16 G02B 1/10 Z (72) Inventor Akihiro Matsufuji 210 Nakamura, Minamiashigara City, Kanagawa Prefecture Fuji Photo Film Co., Ltd. F-term (reference) 2K009 AA15 BB24 BB28 CC09 CC21 DD02 DD09 4F006 AA02 AA22 AA31 AA35 AA36 AB43 AB74 AB76 BA02 CA08 EA02 CA08 EA02 4F070 AA02 AA32 AA47 AA48 AA50 AA68 AC13 AC14 AC15 AC16 AC20 AC23 AC27 AC76 AC83 AC88 AD01 AD02 AD06 AE01 AE30 BB08 DA41 DC07 FA01 FC05 FC06 4F071 AA22X AA31X AA 33 AA39 AA45 AA45X AA46 AA46X AA48 AA50 AA69 AA73 AB18 AB24 AB26 AD01 AD02 AD05 AD06 AF25 AF30 AH16 BA01 BB06 BB07 BC01 BC17 4F100 AA01A AK01A AK01A12 JN12A01 JN12A08J12A81J12A81J12A81J12A81J12A81A12A81A12A81A12A81A02A81A06A02 AR20 BA01 BA04 BC13 BC15 BC37 BD05 BK02 BK13 BN30 4J002 AB021 BG061 BK001 CF031 CF071 CF081 CF161 CG011 DE096 DE136 DE146 DJ016 DJ036 DJ046 DJ056 FB086 FB096 FB236 FB266 FD016 FD206 GQ00

Claims (12)

[Claims] 1. A step of melt-kneading a filler and a resin,
In a method for producing a high surface hardness film including a step of forming a filler-containing layer in a step including an extrusion molding step,
A method for producing a high surface hardness film, characterized in that the resin is crushed and then used in the step of melt-kneading. 2. The method for producing a high surface hardness film according to claim 1, comprising a step of laminating a hard coat layer on the filler-containing layer. 3. The crushed resin has a size of 0.
It is 003 mm or more and 3 mm or less, The manufacturing method of the high surface hardness film of Claim 1 or 2 characterized by the above-mentioned. 4. The method for producing a high surface hardness film according to claim 1, wherein the resin is a polyester resin. 5. The method for producing a high surface hardness film according to claim 1, wherein the filler is inorganic or organic fine particles. 6. The particle size of the filler is 1 nm or more and 400 n
The method for producing a high surface hardness film according to claim 5, wherein the film has a thickness of m or less. 7. The difference in refractive index between the filler and the resin is 0.5.
It is the following, The manufacturing method of the high surface hardness film in any one of Claims 1-6. 8. The filler is contained in an amount of 5% by mass or more and 50% by mass or less with respect to the resin.
8. The method for producing a high surface hardness film according to any one of 7. 9. A high surface hardness film in which a filler and a resin are melt-kneaded and a hard coat layer is laminated on a filler-containing layer produced by extrusion molding, and the resin used in the melt-kneading is crushed. A high surface hardness film characterized by being used. 10. The size of the crushed resin is
The high surface hardness film according to claim 9, wherein the film has a thickness of 0.003 mm or more and 3 mm or less. 11. The high surface hardness film according to claim 9, which has a haze of 8% or less. 12. The high surface hardness film according to claim 9, which has a transmittance of 85% or more.