JP2020040350A - Laminated film roll - Google Patents

Abstract

To provide a laminated film roll which is suppressed in occurrence of scratch, is excellent in transparency and workability, and is excellent in uniform physical property of a film roll.SOLUTION: The laminated film roll is provided that is formed by winding a laminated film having a substrate layer and a resin layer, the resin layer contains 30 wt.% or more and 50 wt.% or less of alumina particles with respect to the resin layer, at a shrinkage start temperature Ts (°C) of five points of both ends of the laminated film roll on a line extending in a width direction of the laminated film roll, a point positioned 100 mm inside from both of the ends, and a center part in the width direction, the maximum change amount of the shrinkage start temperature Ts (°C) (difference between the highest shrinkage start temperature and the lowest shrinkage start temperature) is within 10°C, and both of the shrinkage start temperatures Ts (°C) are 140°C or higher. The shrinkage start temperature Ts (°C) of the laminated film is a temperature of a drop point which is measured after a temperature has been raised to 200°C from 25°C at a temperature rising rate of 10°C/min while applying a load of 40 g in the longitudinal direction of the film to the laminated film and is observed on the highest temperature side, in thermomechanical analysis (TMA).SELECTED DRAWING: None

Description

  The present invention relates to a laminated film roll in which scratches are suppressed, transparency and processability are excellent, and physical properties of the film roll are uniform.

  Thermoplastic resin films, especially biaxially stretched polyester films, have excellent properties such as mechanical properties, electrical properties, dimensional stability, transparency, and chemical resistance. Widely used in applications. In particular, in recent years, it has been used for various optical films including display members such as touch panels, liquid crystal display panels (LCD), plasma display panels (PDP), and organic electroluminescence (organic EL).

  In these optical films, a step of providing a hard coat layer, a step of providing an optical adjustment layer, and a step of providing a conductive layer are generally performed individually. In the step of providing a hard coat layer, after the hard coat layer is laminated on the polyester film, a hard coat is also provided on the back side to suppress adhesion (blocking) of the film surface when wound up as a film roll. ing. In the step of providing the optical adjustment layer, a layer having a different refractive index (hereinafter, an optical adjustment layer) is further laminated on the hard coat layer on the surface. In the step of providing a conductive layer, indium, tin, copper, and the like as a type of the conductive layer are deposited on a roll film by sputtering under a vacuum environment at a high temperature, or these metal oxide films are dispersed at a high temperature, and wet coating is performed. It is common that the optical film is finally used as a conductive film.

  Laminated films used for optical applications are required to have transparency in addition to scratch resistance obtained from a hard coat layer. Further, since it is often used on the surface of a display or the like, visibility and design are required for a laminated film used for optical applications.

  To cope with such a demand, Patent Document 1 discloses a laminated film having both transparency and scratch resistance by specifying the micro surface roughness and the macro surface roughness of a polyester film. Patent Document 2 discloses a laminated film in which fine particles having a Mohs hardness of 4 or more are added to a coating layer of a polyester film.

WO 2017/22765 pamphlet JP 2004-74682 A

  However, the method described in Patent Document 1 does not consider the uniformity of physical properties of the film roll, and thus cannot particularly satisfy variations in heat shrinkage and curl resistance, which are physical properties of the film in the width direction. Was. Also, in the method described in Patent Document 2, the coating layer containing a large amount of fine particles has a small heat shrinkage component, and the difference in heat shrinkage from the polyester film can satisfy the curl resistance of the film. Did not.

  An object of the present invention is to provide a laminated film roll in which scratches are suppressed, transparency and processability are excellent, and physical properties of the film roll are uniform.

The present invention employs the following means in order to solve such a problem. That is,
However, the shrinkage onset temperature Ts (° C.) is from 25 ° C. to 200 ° C. at a rate of 10 ° C./min by thermomechanical analysis (TMA) while applying a load of 40 g on the laminated film in the longitudinal direction of the laminated film. This is the temperature at the descent point observed on the hottest side, measured with increasing temperature.

  (2) The laminated film roll according to (1), wherein the width of the laminated film roll is 250 mm or more and 2500 mm or less.

  (3) The heat shrinkage in the longitudinal direction (MD direction) of the laminated film when heated at 150 ° C. for 60 minutes is such that the heat shrinkage is 100 mm inward from both ends of the laminated film on a line extending in the width direction of the laminated film. The laminated film roll according to (1) or (2), wherein each of the located point and the five points at the center in the width direction is 0.0% or more and 1.0% or less.

  (4) The heat shrinkage in the direction (TD direction) perpendicular to the longitudinal direction of the laminated film when heated at 150 ° C. for 60 minutes is such that both ends of the laminated film on a line extending in the width direction of the laminated film; The laminated film roll according to any one of (1) to (3), wherein each of the points located 100 mm inward from both ends and the five points at the center in the width direction is 0.0% or more and 1.0% or less. .

  ADVANTAGE OF THE INVENTION According to this invention, the laminated film roll which was excellent in the transparency and processability which was suppressed and which was excellent in the uniformity of the physical property of a film roll can be provided. More specifically, since it has excellent heat shrinkage variation in the width direction and excellent curl resistance, it can be suitably used for a hard coat film conventionally used for displays and a hard coat film used for molding and decoration.

  Hereinafter, the laminated film roll of the present invention will be described in detail.

  Here, the shrinkage onset temperature Ts (° C.) in the present invention refers to a temperature rising rate of 10 ° C./25° C. by thermomechanical analysis (TMA) while applying a load of 40 g on the laminated film in the longitudinal direction of the laminated film. It refers to the temperature of the drop point observed on the highest temperature side, measured by raising the temperature to 200 ° C. in minutes.

  The resin layer of the laminated film wound around the laminated film roll of the present invention needs to contain 30% by weight or more and 50% by weight or less of alumina particles with respect to the resin layer. Since alumina particles have high hardness, the scratch resistance of the laminated film can be improved. If the amount of the alumina particles is less than 30% by weight, the density of the alumina particles contained in the resin layer may decrease, and the scratch resistance may deteriorate. On the other hand, alumina particles have high thermal conductivity while having high hardness. Therefore, when the alumina particles are contained in an amount exceeding 50% by weight with respect to the resin layer, the laminated film becomes sensitive to heat, and the shrinkage start temperature Ts (° C.) in the width direction in the production process of the laminated film roll described later. The curl resistance is reduced by increasing the maximum change amount.

  The laminated film wound up on the laminated film roll of the present invention can be used for touch panels, protective films, window covering films, etc., and these applications are used as a post-process for providing a hard coat layer or conductivity. , For example, tin, indium, copper, silver or the like. At this time, if the laminated film is curled, problems such as poor flatness of a processed portion, poor dimensional processing at the time of cutting, poor transportability at the time of processing, and an adverse effect on yield are caused. Therefore, not only high scratch resistance is required, but also curl resistance is required.

  As described above, the shrinkage onset temperature Ts (° C.) is observed at the highest temperature, measured by thermomechanical analysis (TMA) by increasing the temperature from 25 ° C. to 200 ° C. at a rate of 10 ° C./min. It represents the temperature at the falling point. The temperature represents the temperature at which the film starts shrinking in the longitudinal direction when the laminated film is heated, and the higher the shrinkage start temperature Ts (° C.), the smaller the amount of shrinkage in the longitudinal direction of the laminated film during heating. Show a tendency to become When the shrinkage onset temperature Ts (° C.) is 140 ° C. or higher, it is difficult to shrink in the longitudinal direction even during the high-temperature heating described above. Become. Therefore, curl resistance can be improved. It is more preferably at least 150 ° C., even more preferably at least 160 ° C. The upper limit of the shrinkage initiation temperature Ts (° C.) is not particularly limited as long as the effect of the present invention is not hindered, but is preferably 180 ° C. or less from the viewpoint of dimensional stability.

  Further, in the laminated film wound on the laminated film roll of the present invention, the above-mentioned shrinkage start temperature Ts (° C.) is 100 mm inward from both ends of the laminated film on a line extending in the width direction of the laminated film. It is necessary that the temperature be 140 ° C. or higher at any of the points located at the center position and the five points at the center in the width direction. Both ends in the width direction of the laminated film are more likely to be heated to a high temperature in the heat treatment step and the relaxation step in the longitudinal direction because the distance from the heating heat source is shorter than the center part in the width direction. Therefore, the shrinkage start temperature Ts (° C.) tends to be lower than that in the center in the width direction. This tendency is remarkable in a laminated film containing alumina particles having high thermal conductivity at a high concentration. Therefore, even if the shrinkage start temperature Ts (° C.) at the center in the width direction is 140 ° C. or more, the shrink start temperature Ts (° C.) at both ends in the width direction and at a point located 100 mm inside from both ends. ) May result in a laminated film having a temperature of less than 140 ° C. Such a laminated film cannot provide an effect of improving curl resistance. The method of controlling Ts (° C.) at both ends of the laminated film, points located 100 mm inward from both ends, and five points at the center in the width direction is not particularly limited. A method for controlling the difference in physical properties between the center and both ends in the width direction of the film may be used.

  The maximum change of the shrinkage start temperature Ts (° C.) of the laminated film wound around the laminated film roll of the present invention must be 10 ° C. or less. In recent years, it has been considered that processing of a touch panel, a protective film, and a window covering film is performed in a shorter time, and as a result, heating processing conditions have become more severe. Therefore, even if the shrinkage initiation temperature Ts (° C.) is 140 ° C. or more at any of the both ends in the width direction, the point located 100 mm inward from the both ends, and the five points at the center in the width direction, If the maximum change amount of the shrinkage start temperature Ts (° C.) (the difference between the highest shrinkage start temperature and the lowest shrinkage start temperature among the five points of shrinkage start temperature) is large, the curl is increased in the case of the heating processing under more severe conditions. Cannot be suppressed. In a laminated film containing alumina particles having high thermal conductivity at a high concentration, the maximum change amount of the shrinkage initiation temperature Ts (° C.) tends to be remarkably large. The maximum change amount of the shrinkage start temperature Ts (° C.) can be controlled even in the case of a laminated film containing a concentration. The maximum change amount of the contraction start temperature Ts (° C.) is more preferably 5 ° C. or less.

  Here, the maximum change amount of the shrinkage start temperature Ts (° C.) in the present invention refers to the difference in the curl amount in the width direction of the laminated film roll when processing at a temperature higher than the shrinkage start temperature Ts (° C.).

  The width of the laminated film roll of the present invention is preferably 250 mm or more from the viewpoint of productivity. Although the maximum width of the laminated film roll is not particularly limited, the maximum width of the shrinkage start temperature Ts (° C.) increases as the width increases, and therefore, it is preferably 2500 mm or less. More preferably, it is 500 mm or more and 2000 mm or less.

  The laminated film wound on the laminated film roll of the present invention has a heat shrinkage in the longitudinal direction (MD direction) of the film when heated at 150 ° C. for 60 minutes. It is preferable that all of the both ends of the film, points located 100 mm inward from both ends, and five points at the center in the width direction are 1.0% or less.

  The laminated film wound on the laminated film roll of the present invention has a heat shrinkage in the width direction (TD direction) of the laminated film when heated at 150 ° C. for 60 minutes on a line extending in the width direction of the laminated film. It is preferable that all of the both ends of the laminated film, the points located 100 mm inward from the both ends, and the five points at the center in the width direction are 1.0% or less.

  The heat shrinkage in the longitudinal direction and the width direction is 1 point at each of the 5 points at both ends of the laminated film on the line extending in the width direction of the laminated film, at a point located 100 mm inward from both ends, and at the center in the width direction. If it is 0.0% or less, dimensional stability during processing is good. Preferably, each is 0.8% or less, more preferably 0.7% or less. Further, since there is a correlation between the heat shrinkage in the MD direction and the heat shrinkage in the TD direction, the shrinkage start temperature Ts (° C.) is 140 ° C. by considering the balance between the heat shrinkage in the MD and TD directions. It becomes easy to do above. Therefore, the maximum value of the heat shrinkage in the longitudinal direction (the highest heat shrinkage of the five points) and the maximum value of the heat shrinkage in the width direction (the highest heat shrinkage of the five points) Ratio) is preferably 0.1 to 1.0%, and more preferably 0.2 to 0.7% or less.

  Further, the difference in the heat shrinkage in the longitudinal direction (MD direction) between the both ends of the laminated film on the line extending in the width direction of the laminated film, the point located 100 mm inward from the both ends, and the five central portions in the width direction. (The difference between the highest heat shrinkage and the lowest heat shrinkage among the five heat shrinkages) is preferably 0.5% or less, more preferably 0.2% or less.

  In addition, the difference between the heat shrinkage in the width direction (TD direction) of five points at both ends of the laminated film on the line extending in the width direction of the laminated film, a point located 100 mm inward from both ends, and a central part in the width direction. (The difference between the highest heat shrinkage and the lowest heat shrinkage among the five heat shrinkages) is preferably 0.5% or less, more preferably 0.2% or less.

  In the laminated film wound around the laminated film roll of the present invention, the resin layer preferably contains an acrylic resin. In particular, it is preferable to include at least one of acrylic resin (A), acrylic resin (C), and acrylic resin (D) described later. By using at least one of the acrylic resin (A), the acrylic resin (C), and the acrylic resin (D), the hardness of the resin layer surface can be improved while maintaining transparency. As a result, the scratch resistance of the laminated film can be improved.

  The acrylic resin (A) in the present invention is a cured composition composed of a monomer component (a) having an acryloyl group in a molecule. Among these, the monomer component (a) is preferably a polyfunctional acrylate having three or more acryloyl groups in the molecule. The polyfunctional acrylate is a monomer or oligomer having 3 (more preferably 4, more preferably 5 or more) (meth) acryloyl groups in one molecule. Examples of such a composition include compounds in which the hydroxyl group of a polyhydric alcohol having three or more alcoholic hydroxyl groups in one molecule is an esterified product of three or more (meth) acrylic acids. it can.

  Specific examples include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol triacrylate hexane methylene diisocyanate urethane polymer and the like can be used. These monomers can be used alone or in combination of two or more. Commercially available polyfunctional acrylic compositions include Mitsubishi Rayon Co., Ltd. (trade name "Diabeam" (registered trademark) series, etc.), Nagase & Co., Ltd .; (trade name "Denacol" (registered trademark) series) Etc.), Shin-Nakamura Co., Ltd. (trade name "NK Ester" series, etc.), Dainippon Ink & Chemicals, Inc .; (trade name "UNIDIC" (registered trademark), etc.), Toa Gosei Chemical Co., Ltd .; Nippon Oil & Fats Co., Ltd .; Kyoeisha Chemical Co., Ltd .; Nippon Kayaku Co., Ltd .; (Trade name “Light Ester” series, etc.), and these products can be used.

  In the present invention, it is preferable to use an acrylic resin (A) obtained by using an acrylic monomer component having an amide bond as the acrylic resin (A) because scratch resistance is particularly improved. The present inventors presume the reason for this as follows. When an acrylic monomer component having an acryloyl group is cured in the presence of an oxygen atom in the atmosphere, the radical polymerization reaction of the acryloyl group may be inhibited by the oxygen atom in the atmosphere, and as a result, Insufficient curing may result in poor scratch resistance. If the acrylic monomer component containing an acryloyl group has an amide bond, the oxygen atom in the atmosphere interacts with the amide bond, which is highly polar, so the curing inhibition of the radical polymerization reaction of the acryloyl group by the oxygen in the atmosphere is suppressed. As a result, it is presumed that the curing of the acrylic resin proceeds, and the scratch resistance is particularly improved. Examples of the acrylic monomer component having an amide bond include a compound having a structure represented by the following (formula 1).

The acrylic resin (C) in the present invention is a resin having a monomer unit (f ₁ ) represented by (Formula 2).

(In Formula 2, R ₃ represents a hydrogen atom or a methyl group. R ₅ represents a hydroxyl group, a carboxyl group, a tertiary amino group, a quaternary ammonium base, a sulfonic acid group, or a phosphoric acid group. Represents a group.)
When an acrylic resin having a monomer unit in which the R ₅ group in Formula 2 does not have any of a hydroxyl group, a carboxyl group, a tertiary amino group, a quaternary ammonium group, a sulfonic acid group, and a phosphoric acid group is used, Becomes insufficient in the aqueous solvent, and the acrylic resin (C) is unevenly present in the resin composition. As a result, a portion of the resin layer has poor scratch resistance, which is not preferable.

  In addition, the pressure on the resin layer when rubbing is locally increased by coagulation or sedimentation of the alumina particles (B) to be described later or coagulation of the alumina particles (B) in the drying step. The layer may be broken, leading to scratching.

Furthermore, since such agglomerates are larger than the wavelength of visible light, a laminated film having good transparency may not be obtained in some cases. In order for the acrylic resin (C) in the present invention to have the monomer unit (f ₁ ) represented by the following (Formula 2), the (meth) acrylate monomer (f ₁ ′) represented by (Formula 3) Need to be used as a raw material for polymerization.

The following compounds are exemplified as the (meth) acrylate monomer (f ₁ ′) represented by (Formula 3).

  As the (meth) acrylate monomer having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene Monoesters of polyhydric alcohols such as glycol mono (meth) acrylate and (meth) acrylic acid, and compounds obtained by ring-opening polymerization of ε-caprolactone with the monoesters, and particularly 2-hydroxyethyl ( (Meth) acrylate and 2-hydroxypropyl (meth) acrylate are preferred.

  Examples of the (meth) acrylate monomer having a carboxyl group include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and maleic acid, or hydroxyalkyl (meth) acrylate and acid anhydride. And the like, and particularly preferred are acrylic acid and methacrylic acid.

  Examples of the tertiary amino group-containing monomer include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, and N, N-dimethylaminopropyl (meth) acrylate. N, N-dialkylamino such as dialkylaminoalkyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide Alkyl (meth) acrylamide and the like are mentioned, and N, N-dimethylaminoethyl (meth) acrylate is particularly preferable.

  The quaternary ammonium group-containing monomer is preferably a monomer obtained by allowing a quaternizing agent such as epihalohydrin, benzyl halide, or alkyl halide to act on the tertiary amino group-containing monomer, and specifically, 2- (methacryloyloxy). ) Ethyltrimethylammonium chloride, 2- (methacryloyloxy) ethyltrimethylammonium bromide, (meth) acryloyloxyalkyltrialkylammonium salts such as 2- (methacryloyloxy) ethyltrimethylammonium dimethylphosphate, methacryloylaminopropyltrimethylammonium chloride, methacryloyl (Meth) acryloylaminoalkyltrialkylammonium salts such as aminopropyltrimethylammonium bromide, tetrabutylamine Tetra (meth) acrylates such as bromide (meth) acrylate, and tri-alkyl benzyl ammonium (meth 9 acrylates such as trimethylbenzylammonium (meth) acrylate. In particular 2- (methacryloyloxy) ethyl trimethyl ammonium chloride are preferred.

  Examples of the sulfonic acid group-containing monomer include (meth) acrylamide-alkanesulfonic acid such as butylacrylamidesulfonic acid and 2-acrylamido-2-methylpropanesulfonic acid, and sulfoalkyl (meth) such as 2-sulfoethyl (meth) acrylate. Acrylate and the like can be mentioned, and 2-sulfoethyl (meth) acrylate is particularly preferable.

  Examples of the phosphoric acid group-containing acrylic monomer include acid phosphooxyethyl (meth) acrylate, and particularly preferred is acid phosphooxyethyl (meth) acrylate.

Among them, the acrylic resin (C) is a resin having the monomer unit (f ₁ ) represented by the above (Formula 2), and the R ₅ group in (Formula 2) is a hydroxyl group or a carboxyl group. This is preferable in that the adsorbing power with the alumina particles (B) described later is increased, a stronger film can be formed, and the scratch resistance is improved. As a method of using the acrylic resin (C) to have a macro surface roughness of 1 nm or more and 50 nm or less, a method of giving fine stretching unevenness by performing a stretching process on a resin layer in a state where the acrylic resin is not yet cured. At this time, it is important that the thickness of the resin layer is 300 nm or more. With the above thickness, fine stretching unevenness expresses an appropriate height, and the anti-blocking property can be improved.

  The content of the acrylic resin in the resin layer in the present invention is preferably 10% by weight or more and 90% by weight or less, and by setting the content in this range, the scratch resistance of the resin layer can be improved.

  In particular, when the acrylic resin (A) is used as the acrylic resin, the content of the acrylic resin (A) is more preferably 40% by weight or more and 90% by weight or less based on the entire resin layer, The content of the acrylic resin (A) is preferably 40% by weight or more and 80% by weight or less, more preferably 45% by weight or more and 70% by weight or less.

  When the acrylic resin (C) is used as the acrylic resin, the content of the acrylic resin (C) in the resin layer is preferably 20% by weight or more and 80% by weight or less based on the entire resin layer, more preferably. Is from 40% by weight to 80% by weight, more preferably from 45% by weight to 70% by weight.

  In addition, in this invention, the content in a resin layer represents the content in the solid content ([(weight of resin composition)-(weight of solvent)]) of the resin composition which forms a resin layer.

  The alumina particles (B) in the present invention are a composition (B-2) obtained by bonding the alumina particles (B-1) and a resin component containing an acryloyl group, or a part of the surface of the alumina particles (B-1). Alternatively, it is preferable to use the composition (B-3) having the acrylic resin (D) in all. Here, the bond may be a covalent bond or a non-covalent bond (physical adsorption).

  As an example of the resin composition (B-2) obtained by bonding the alumina particles (B-1) and the resin component containing an acryloyl group, the resin composition containing the alumina particles (B-1) and the acryloyl group is bonded (surface). Modified). By binding the alumina particles (B-1) and the resin component containing an acryloyl group, the alumina particles can be prevented from falling off when a force is applied to the resin layer, and the scratch resistance can be improved.

  As a specific method of bonding the alumina particles (B-1) and the resin component containing an acryloyl group, the resin component containing an acryloyl group is a resin component having a silanol group, or a resin component generating a silanol group by hydrolysis. Is preferred.

  Next, the resin component containing an acryloyl group contained in the resin composition (B-2) containing the alumina particles (B) will be described. The resin component containing an acryloyl group is a compound having an acryloyl group and a hydrolyzable silyl group. The hydrolyzable silyl group is a group that reacts with water to generate a silanol group. For example, one or more methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group An alkoxy group, an aryloxy group, an acetoxy group, an amino group, or a compound in which a halogen atom is bonded.

  The particles obtained by bonding the alumina particles (B-1) and the resin component containing an acryloyl group are obtained by mixing the resin component (B-2) containing an acryloyl group having a hydrolyzable silyl group with the alumina particles (B-1). Then, it is hydrolyzed, and the two can be bonded to each other. Since the particles thus obtained have reacted with the acrylic resin (A), the alumina particles are less likely to fall off when the resin layer is rubbed, so that the scratch resistance becomes excellent.

  The ratio of the alumina particle (B-1) to the resin component containing an acryloyl group contained in the resin composition (B-2) containing the alumina particle (B) is such that the resin composition contains the alumina particle (B-1) and the acryloyl group. When the amount of the component is 100 parts by weight, the amount of the resin component (B-2) containing an acryloyl group is preferably 0.1 to 50 parts by weight. Within this range, both scratch resistance, transparency and anti-blocking properties can be achieved without the alumina particles falling off. When the resin component containing an acryloyl group exceeds 50 parts by weight, the density of the alumina particles contained in the resin layer decreases, and the scratch resistance may deteriorate.

  In addition, the composition (B-3) having the acrylic resin (D) on part or all of the surface of the alumina particles (B-1) of the present invention refers to a part or all of the surface of the alumina particles (B-1). It is preferable that the particles have the acrylic resin (D) described above.

The acrylic resin (D) here is a resin having a monomer unit (g ₁ ) represented by (Formula 4) and a monomer unit (g ₂ ) represented by (Formula 5).

(In (Formula 4), the R ₁ group represents a hydrogen atom or a methyl group, and n represents an integer of 9 to 34).

(In (Formula 5), the R ₂ group represents a hydrogen atom or a methyl group. The R ₄ group represents a group containing two or more saturated carbon rings.)

The acrylic resin (D) in the present invention is preferably a resin having a monomer unit (g ₁ ) represented by (Formula 4). When the acrylic resin (D) has the monomer unit (g ₁ ) represented by (Equation 4), the surface energy of the resin layer is reduced, so that the friction coefficient applied to the resin layer when subjected to the rubbing treatment is small. Thus, the scratch resistance can be improved.

  Further, in Formula 4, when an acrylic resin having a monomer unit in which n is less than 9 is used, the dispersibility of the alumina particles (B) in an aqueous solvent (the details of the aqueous solvent will be described later) is unstable. Becomes When an acrylic resin having a monomer unit in which n in Formula 4 is less than 9 is used, the alumina particles (B) aggregate or settle in the resin composition, or the alumina particles (B) aggregate in the drying step. Sometimes. As a result, the transparency of the laminated film may be impaired, or the scratch property may be poor. On the other hand, an acrylic resin having a monomer unit in which n exceeds 34 in (Formula 4) has remarkably low solubility in an aqueous solvent, so that the acrylic resin easily aggregates in the aqueous solvent. Since such aggregates are larger than the wavelength of visible light, a laminated film having good transparency may not be obtained in some cases.

In order for the acrylic resin (D) in the present invention to have the monomer unit (g ₁ ) represented by (Formula 4), the (meth) acrylate monomer (g ₁ ′) represented by the following (Formula 6) Need to be used as a raw material for polymerization.

As the (meth) acrylate monomer (g ₁ ′), a (meth) acrylate monomer in which n in (Formula 6) is an integer of 9 or more and 34 or less is preferable, and more preferably 11 or more and 32 or less of (meth) Acrylate monomers, more preferably 13 to 30 (meth) acrylate monomers.

The (meth) acrylate monomer (g ₁ ′) is not particularly limited as long as n in Formula 6 is a (meth) acrylate monomer in which n is 9 or more and 34 or less. Specifically, decyl (meth) acrylate, dodecyl ( (Meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, 1-methyltridecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, eicosyl (meth) acrylate, docosyl (meth) acrylate, Examples thereof include tetracosyl (meth) acrylate and triacontyl (meth) acrylate, and particularly preferred are dodecyl (meth) acrylate and tridecyl (meth) acrylate. These may be used alone or as a mixture of two or more.

The acrylic resin (D) in the present invention is preferably a resin having a monomer unit (g ₂ ) represented by the above (Formula 5). When the acrylic resin (D) has the monomer unit (g ₂ ) represented by (Formula 5), the resin layer becomes rigid under the influence of the steric hindrance of the saturated carbon ring, and the scratch resistance can be improved. .

  Further, in Formula 5, when an acrylic resin having a monomer unit containing only one saturated carbon ring is used, the function as steric hindrance becomes insufficient, and the alumina particles (B) aggregate or form in the resin composition. The alumina particles (B) may settle or agglomerate in the drying step.

Since such aggregates are larger than the wavelength of visible light, a laminated film having good transparency may not be obtained in some cases. In order for the acrylic resin (D) in the present invention to have a monomer unit (g ₂ ) represented by (Formula 5), a (meth) acrylate monomer (g ₂ ′) represented by the following (Formula 7) Need to be used as a raw material for polymerization.

As the (meth) acrylate monomer (g ₂ ′) represented by (Formula 7), a cross-linked condensed cyclic compound (having a structure in which two or more rings share two atoms each and are bonded) And various cyclic structures such as spirocyclic (having a structure in which two cyclic structures are bonded by sharing one carbon atom), specifically, compounds having a bicyclo, tricyclo, tetracyclo group and the like. Among them, a (meth) acrylate containing a bicyclo group is particularly preferable from the viewpoint of compatibility with the binder.

  Examples of the (meth) acrylate containing a bicyclo group include isobornyl (meth) acrylate, bornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, adamantyl (meth) acrylate, and dimethyladamantyl. (Meth) acrylate and the like can be mentioned, and isobonyl (meth) acrylate is particularly preferable.

  By having the acrylic resin (D) on the surface of the alumina particles (B-1), the interfacial adhesion between the alumina particles (B-1) and the acrylic resin (D) in the resin layer becomes strong, so that the rubbing treatment is performed. Particle dropout when applied is suppressed, and excellent in scratch resistance. Furthermore, the aggregation of the alumina particles (B) in the drying process can be suppressed, and the micro surface roughness and the macro surface roughness of the resin layer can be set in a predetermined range.

  The method for producing the alumina particles (B-1) is not particularly limited, and examples thereof include a method of subjecting the alumina particles (B-1) to a surface treatment with an acrylic resin (D). Are exemplified by the following methods (i) to (iv). In the present invention, the surface treatment refers to a treatment for adsorbing and attaching the acrylic resin (D) to all or a part of the surface of the alumina particles (B-1).

  (I) A method in which a mixture obtained by previously mixing alumina particles (B-1) and an acrylic resin (C) is added to a solvent and then dispersed.

  (Ii) A method in which alumina particles (B-1) and an acrylic resin (D) are sequentially added and dispersed in a solvent.

  (Iii) A method in which alumina particles (B-1) and acrylic resin (D) are dispersed in a solvent in advance, and the obtained dispersion is mixed.

  (Iv) A method of dispersing the alumina particles (B-1) in a solvent and then adding an acrylic resin (D) to the obtained dispersion.

  The desired effect can be obtained by any of these methods.

  In addition, as a device for performing dispersion, a dissolver, a high-speed mixer, a homomixer, a meader, a ball mill, a roll mill, a sand mill, a paint shaker, an SC mill, an annular mill, a pin mill, and the like can be used.

  As a dispersing method, the rotating shaft is rotated at a peripheral speed of 5 to 15 m / s using the above device. The rotation time is between 5 and 10 hours.

  Further, at the time of dispersion, it is more preferable to use dispersed beads such as glass beads from the viewpoint of enhancing dispersibility. The bead diameter is preferably 0.05 to 0.5 mm, more preferably 0.08 to 0.5 mm, and particularly preferably 0.08 to 0.2 mm.

  The method of mixing and stirring can be performed by shaking the container by hand, using a magnetic stirrer or a stirring blade, performing ultrasonic irradiation, vibration dispersion, and the like.

  The presence / absence of adsorption / adhesion of the acrylic resin (D) to all or part of the surface of the alumina particles (B-1) can be confirmed by the following analysis method. The object to be measured (for example, the composition (B-3) containing the alumina particles (B-1)) is centrifuged with a Hitachi tabletop ultracentrifuge (CS150NX, manufactured by Hitachi Koki Co., Ltd.) (rotation speed 3, 0000 rpm, separation time 30 minutes), and after sedimentation of the alumina particles (B-1) (and the acrylic resin (D) adsorbed on the surface of the alumina particles (B-1)), the supernatant was removed and the sediment was removed. Concentrate to dryness. The concentrated and dried precipitate is analyzed by X-ray photoelectron spectroscopy (XPS) to confirm the presence or absence of the acrylic resin (C) on the surface of the alumina particles (B-1). When it is confirmed that 1% by weight or more of the acrylic resin (D) is present on the surface of the alumina particles (B-1) with respect to 100% by weight of the alumina particles (B-1) in total, the alumina particles (B-1) It is assumed that the acrylic resin (D) is adsorbed and adhered to the surface of -1).

  Here, the number average particle diameter of the alumina particles (B-1) will be described. Here, the number average particle diameter refers to a particle diameter determined by a transmission electron microscope (TEM). The magnification is 500,000, and the outer diameter of 10 particles present on the screen is the number average particle diameter obtained by measuring a total of 100 particles in 10 visual fields. Here, the outer diameter refers to the maximum diameter of the particle (that is, the longest diameter of the particle and indicates the longest diameter in the particle). Similarly, in the case of a particle having a cavity inside, the maximum diameter of the particle Represent.

  When the number average particle diameter of the alumina particles (B) is smaller than 1 nm, van der Waals force between the particles increases, and as a result of the particles agglomerating, light scattering occurs and the transparency may decrease. On the other hand, when the number average particle diameter of the alumina particles (B) is larger than 100 nm, from the viewpoint of transparency, it may be a starting point of light scattering and the transparency may be deteriorated. In addition, the filling of the alumina particles in the coating film may not proceed sufficiently, and the scratch resistance may decrease. Therefore, the alumina particles (B) preferably have a number average particle diameter of 5 nm or more and 100 nm or less. Preferably it is 10 nm or more and 80 nm or less, more preferably 20 nm or more and 60 nm or less.

  The alumina particles (B-1) contained in the resin layer in the present invention preferably have a range of 30 to 50 parts by weight, more preferably 40 to 50 parts by weight, based on 100 parts by weight of the acrylic resin (A). . When the content is in the above range, both transparency and scratch resistance can be achieved.

  In the present invention, the amount of the alumina particles (B) contained in the resin layer is preferably in the range of 40 to 100 parts by weight with respect to the total of 100 parts by weight of the acrylic resin (C) and the acrylic resin (D). By setting the content within the above range, it is possible to achieve both transparency and scratch resistance while improving the uniformity of physical properties in the width direction of the film.

  The resin constituting the base layer in the laminated film wound around the laminated film roll of the present invention is preferably a thermoplastic resin such as polyester, polyamide, polyolefin, polyether, polyphenylene sulfide, and polyimide. Among them, polyester is preferably used from the viewpoints of transparency and film forming properties. Hereinafter, a case where polyester (hereinafter, a polyester layer used as a base layer may be referred to as a polyester film) is used as a resin constituting the base layer will be described.

  First, polyester is a generic term for polymers having an ester bond in the main chain, and includes ethylene terephthalate, propylene terephthalate, ethylene-2,6-naphthalate, butylene terephthalate, propylene-2,6-naphthalate, ethylene-α, β -Bis (2-chlorophenoxy) ethane-4,4'-dicarboxylate and at least one component selected therefrom can be preferably used.

  The polyester film using the polyester is preferably biaxially oriented. The biaxially oriented polyester film is generally stretched by about 2.5 to 5 times in a longitudinal direction and a width direction orthogonal to the longitudinal direction, respectively, of an unstretched polyester sheet or film, and then subjected to a heat treatment to obtain a crystal. This means that the orientation has been completed and shows a biaxial orientation pattern in wide-angle X-ray diffraction. When the polyester film is biaxially oriented, thermal stability, especially dimensional stability and mechanical strength are sufficient, and flatness is also good.

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

  The thickness of the polyester film in the present invention is not particularly limited, and is appropriately selected depending on the application and type.However, from the viewpoint of mechanical strength and handling properties, it is usually preferably 10 to 500 μm, more preferably It is 15 to 250 μm, most preferably 20 to 200 μm. Further, the polyester film may be a composite film obtained by co-extrusion or a film obtained by laminating the obtained films by various methods.

  Examples will be shown below for the method of manufacturing the resin layer of the laminated film roll of the present invention, but the materials, usage amounts, ratios, processing details, processing procedures, and the like shown below may be appropriately changed without departing from the spirit of the present invention. Can be. Therefore, the scope of the present invention should not be construed as limited by the following examples.

  When the resin layer of the present invention contains an acrylic resin selected from at least one of an acrylic resin (A) and / or an acrylic resin (C) and inorganic particles (B), the resin layer has transparency, scratch resistance, Excellent in anti-blocking properties, preferred.

  In the resin layer, if necessary, other compounds other than (A), (C) and (B), for example, polymer resins such as polyester resin, acrylic resin and urethane resin, carbodiimide compounds, oxazoline compounds , Aziridine compounds, titanate-based coupling agents such as titanium chelates, and methylolated or alkylolated melamine compounds. Further, various additives, for example, an organic lubricant, organic or inorganic fine particles, an antistatic agent and the like may be added to such an extent that their properties are not deteriorated.

  Particularly, as the compound other than (A), (C) and (B), an oxazoline compound and / or a melamine compound are preferable, and it is particularly preferable to contain a melamine compound.

  Examples of the melamine-based compound include melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, a compound partially or completely etherified by reacting a lower alcohol with methylolated melamine, and a mixture thereof. Can be used. Specifically, a compound having a triazine and a methylol group is particularly preferable. Further, the melamine-based compound may be any of condensates comprising a monomer, a dimer or higher, or a mixture thereof. As the lower alcohol used for the etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like can be used. Examples of the group include an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group in one molecule, and include an imino group-type methylated melamine resin, a methylol group-type melamine resin, and a methylol group-type methyl group. Melamine resins, fully alkylated methylated melamine resins, 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 compound.

  When such a melamine compound is used, not only the scratch resistance is improved due to an increase in the hardness of the coating film due to self-condensation of the melamine compound, but also the reaction between the melamine compound and a hydroxyl group or a carboxylic group contained in the acrylic resin proceeds. , A stronger resin layer can be obtained, and a film having excellent scratch resistance can be obtained. Furthermore, the effect of suppressing the falling of the inorganic particles (B) in the resin layer can prevent the protrusions of the uneven structure required for exhibiting the antiblocking property from being scraped.

  The method for manufacturing a laminated film roll of the present invention will be described below with reference to examples, but the materials, usage amounts, ratios, processing details, processing procedures, and the like shown below may be appropriately changed without departing from the spirit of the present invention. Can be. Therefore, the scope of the present invention should not be construed as limited by the following examples.

  The laminated film roll of the present invention applies an acrylic monomer (a) constituting the acrylic resin (A) and a resin composition (b) containing inorganic particles (B) onto a polyester film, and the resin composition is dissolved in a solvent. When it contains, it can obtain by forming a resin layer on a polyester film by drying a solvent.

  When an acrylic monomer (C) constituting the acrylic resin (C) and a resin composition (b) containing inorganic particles (B) are applied on a polyester film, and the resin composition contains a solvent, It can be obtained by forming a resin layer on a polyester film by drying the solvent.

  In the present invention, when a solvent is contained in the resin composition, it is preferable to use an aqueous solvent as the solvent. By using an aqueous solvent, rapid evaporation of the solvent in the drying step can be suppressed, and not only can a uniform composition layer be formed, but also the environmental load is excellent.

  Here, the aqueous solvent is soluble in water or water such as alcohols such as methanol, ethanol, isopropyl alcohol and butanol; ketones such as acetone and methyl ethyl ketone; glycols such as ethylene glycol, diethylene glycol and propylene glycol. Refers to those in which the organic solvent is mixed at an arbitrary ratio.

  In the present invention, when an aqueous solvent is used, it contains an acrylic monomer (a) constituting the acrylic resin (A), an acrylic monomer (C) constituting the acrylic resin (C), and inorganic particles (B). It is preferable to apply a water-based coating agent containing the resin composition (b). This is applied as a water-based coating agent, compared to an organic solvent-based coating agent, because the water dispersant or emulsifier is arranged in the surface layer of the coating film when the solvent is dry, so that the above-described radical polymerization reaction of the acryloyl group is performed. This is because the inhibition of curing is suppressed and the scratch resistance is excellent even when the thickness of the resin layer is thin.

  As a method for converting the acrylic monomer (a) constituting the acrylic resin (A) or the resin composition (b) containing the inorganic particles (B) into an aqueous coating, the acrylic resin (A) constituting the acrylic resin (A) is used. Examples include a method in which a hydrophilic group such as a carboxylic acid and a sulfonic acid is contained in the resin composition (b) containing the monomer (a) and the inorganic particles (B), and a method in which the resin composition is emulsified using an emulsifier.

  The method of applying the resin composition to the polyester film is preferably an in-line coating method. The in-line coating method is a method of performing application in a process of manufacturing a polyester film. Specifically, it refers to a method in which coating is performed at any stage from melt extrusion of a polyester resin to biaxial stretching, heat treatment, and winding, and is generally substantially non-reflective obtained by melt extrusion and quenching. Unstretched (unoriented) polyester film (A film) in a crystalline state, then uniaxially oriented (uniaxially oriented) polyester film (B film) stretched in the longitudinal direction, or biaxially stretched in the width direction before heat treatment It is applied to any one of stretched (biaxially oriented) polyester films (C film).

  In the present invention, the resin composition is applied to any one of the A film and the B film before the completion of the crystal orientation, and thereafter, the polyester film is stretched in a uniaxial direction or a biaxial direction, and the solvent It is preferable to adopt a method of performing a heat treatment at a temperature higher than the boiling point to complete the crystal orientation of the polyester film and provide a resin layer. According to this method, the production of the polyester film and the application and drying of the resin composition (that is, the formation of the resin layer) can be performed at the same time. Further, since the stretching is performed after the application, it is easy to further reduce the thickness of the resin layer.

  Among them, a method in which a resin composition is applied to a film (B film) uniaxially stretched in a longitudinal direction, and then stretched in a width direction and heat-treated is excellent. After applying to an unstretched film, since the stretching step is one time less than the method of biaxial stretching, it is difficult to generate defects and cracks in the composition layer due to stretching, and a composition layer excellent in transparency and smoothness is formed. This is because it can be formed.

  Further, by providing the resin layer by the in-line coating method, the resin layer can be stretched before the resin layer is completely cured, and a gentle uneven structure can be easily formed. Further, in the uneven structure, when the thickness of the resin layer is 300 nm or more, a more prominent uneven structure can be formed. As a result, the anti-blocking property of the film can be exhibited without forming large projections on the resin layer. In addition, this gentle uneven structure means that the macro surface roughness measured using a three-dimensional roughness meter manufactured by Kosaka Laboratory is 5 to 50 nm.

  In the present invention, the resin layer is preferably provided by an inline coating method from the above various advantages. Here, as a method of applying the resin composition to the polyester film, any known method such as a bar coating method, a reverse coating method, a gravure coating method, a die coating method, and a blade coating method can be used.

  Therefore, the best method of forming a resin layer in the present invention is a method of applying a resin composition using an aqueous solvent onto a polyester film by using an inline coating method, followed by drying and heat treatment. More preferably, a method of in-line coating the resin composition on the B film after uniaxial stretching. In the method for producing a laminated film of the present invention, drying can be performed at a temperature in the range of 80 to 130 ° C. in order to complete the removal of the solvent from the resin composition. In addition, the heat treatment is preferably performed at a maximum temperature of 230 to 250 ° C. in order to complete the crystal orientation of the polyester film, complete the thermosetting of the resin composition, and complete the formation of the resin layer. More preferably, it is carried out in a temperature range of 235 to 240 ° C. If the heat treatment temperature is lower than 230 ° C., the shrinkage initiation temperature Ts (° C.) is lowered, and the curl resistance is lowered.

  Next, the method for producing a laminated film roll of the present invention will be described with reference to an example in which a polyethylene terephthalate (hereinafter, PET) film is used as a polyester film, but the present invention is not limited thereto. First, PET pellets are sufficiently dried in a vacuum, fed to an extruder, melt-extruded into a sheet at about 280 ° C., and cooled and solidified to produce an unstretched (unoriented) PET film (A film). This film is preferably stretched 2.5 to 3.5 times in the longitudinal direction with a roll heated to 80 to 120 ° C. to obtain a uniaxially oriented PET film (B film). More preferably, it is 2.7 to 3.3 times, and still more preferably, it is 2.7 to 3.1 times. If it is less than 2.5 times, the flatness may be reduced. If it exceeds 3.5 times, the maximum change in the shrinkage start temperature Ts (° C.) becomes large, so that the curl resistance may decrease. One side of the B film is coated with the resin composition of the present invention prepared at a predetermined concentration.

  At this time, a surface treatment such as a corona discharge treatment may be performed on the application surface of the PET film before the application. By performing surface treatment such as corona discharge treatment, the wettability of the resin composition to the PET film is improved, repelling of the resin composition is prevented, and a resin layer having a uniform coating thickness can be formed. After the application, the end of the PET film is gripped with a clip and guided to a heat treatment zone (preheating zone) at 80 to 130 ° C. to dry the solvent of the resin composition. After drying, the laminated film is preferably stretched 3.0 to 5.0 times in the width direction. When the transverse stretching ratio is less than 3.0 times, the maximum change amount of the shrinkage initiation temperature Ts (° C.) becomes large, so that the curl resistance may be reduced. More preferably, it is 3.3 to 4.5 times, and still more preferably, it is 3.5 to 4.3 times.

  Thereafter, it is preferable that the crystal orientation is completed by conducting the heat treatment to a heat treatment zone (heat fixing zone) at a temperature higher than 230 ° C. and lower than 250 ° C. for 10 to 30 seconds. More preferably, the temperature is 235 to 245 ° C. When the temperature is 230 ° C. or less, the shrinkage initiation temperature Ts (° C.) in both the longitudinal direction and the width direction decreases, and curling resistance decreases. If the temperature exceeds 250 ° C., the flatness may deteriorate.

  During this heat treatment step (heat fixing step) or in a step after the heat treatment step (heat fixing step), it is preferable to perform a 2.5-6.0% relaxation treatment in the width direction. If the relaxation treatment in the width direction is less than 2.5%, the heat shrinkage in the width direction may increase, and the dimensional stability may decrease. On the other hand, when the relaxation in the width direction exceeds 6.0%, the effect of the relaxation in the longitudinal direction described later cannot be sufficiently obtained, so that the shrinkage start temperature Ts (° C.) becomes low, and the curl resistance may decrease. . Further, it is preferable to perform a relaxation treatment of 0.1 to 3.0%, more preferably 0.5 to 2.0% in the longitudinal direction. If the relaxation treatment in the longitudinal direction is not performed, the shrinkage start temperature Ts (° C.) may decrease, and the curl resistance may decrease. Further, if the relaxation treatment in the longitudinal direction is 3.0% or more, unevenness occurs in the relaxation rate in the width direction of the laminated film, and the maximum change amount of the shrinkage initiation temperature Ts (° C.) becomes large. May decrease. When the difference between the above-described relaxation process (%) in the width direction and the relaxation process (%) in the longitudinal direction is in the range of 0.5 to 5.5%, the shrinkage start temperature Ts (° C.) in the width direction of the laminated film. ) Is preferable because the temperature difference can be reduced. More preferably, it is 1.5 to 5.0%. When performing the relaxation treatment after the heat treatment step (the heat setting step), it is preferable to perform the relaxation treatment at 80 to 160 ° C.

  The laminated film roll thus obtained is a laminated film having excellent transparency, scratch resistance and curl resistance.

  In the laminated film roll of the present invention, an intermediate layer may be provided between the resin layer and the base material layer. In the process up to providing the resin layer of the invention, the film may be scratched. Therefore, in the present invention, it is preferable that the resin layer and the base material layer are directly laminated.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In addition, various characteristics were measured by the following methods.

(1) Shrinkage start temperature Ts
As for the measurement sample, the longitudinal direction of the film roll becomes the length direction at the both ends of the laminated film on the line extending in the width direction of the laminated film, the points located 100 mm inside from the both ends, and the five points at the center in the width direction. 5 mm (width) x 20 mm (length). Using a thermomechanical device (TM-9300) manufactured by ULVAC-RIKO Co., Ltd., a TMA dimensional change curve in which the X-axis is temperature and the Y-axis is expansion ratio is measured in the length direction of the measurement sample under the following measurement conditions. . The temperature at which the value of the expansion ratio observed on the highest temperature side starts to decrease is defined as the shrinkage start temperature (° C.).
[Measurement condition]
Load: 40g (8kgf / m)
Heating rate: 10 ° C / min
Measurement range: 25 ° C to 230 ° C
(2) Heat Shrinkage The measurement sample was prepared by measuring 300 mm in the width direction at the two ends of the laminated film on the line extending in the width direction of the laminated film, the points located 100 mm inward from the both ends, and the five points at the center in the width direction. It was cut out to have a length of 300 mm. A pair of marks was provided at the center of each sample in the longitudinal direction so as to have an interval of 200 mm as the original length (L0). The sample was treated in an oven at 190 ° C. for 60 minutes, cooled to room temperature, the distance between a pair of marks was measured, and the length after the treatment was defined as the length (L1). Then, the heat shrinkage in the longitudinal direction was calculated according to 100 × (L0−L1) / L0.

(4) Alumina particle content The aluminum element was measured from the polyester composition with a fluorescent X-ray elemental analyzer (manufactured by HORIBA, Ltd., type MESA-500W), and the content of alumina particles was determined by a previously determined calibration curve.
[Temperature rising condition]
Starting temperature: 25 ° C
Ultimate temperature: 600 ° C
Heating rate: 10 ° C / min.

(4) Transparency (haze)
In a normal state (23 ° C., 65% relative humidity), after leaving the film for 2 hours, the measurement was performed using a fully automatic direct reading haze computer “HGM-2DP” manufactured by Suga Test Instruments Co., Ltd. The average of three measurements was taken as the haze value of the sample.

The transparency was evaluated in four steps based on the haze value. X is a practically problematic level, Δ is a practical level, and A and S are good.
S: less than 1.0% A: 1.0% or more and less than 1.5% B: 1.5% or more and less than 2.0% C: 2.0% or more.

(5) Scratch resistance Steel wool (Bonstar # 0000, manufactured by Nippon Steel Wool Co., Ltd.) was rubbed back and forth with a load of 200 g / cm ² for 10 times, and the presence or absence of scratches on the surface of the laminated film was visually checked. An evaluation was performed.
S: No scratch A: 1 to 5 scratches B: 6 to 10 scratches C: 11 or more scratches

(6) Curling Resistance The measurement sample was cut out so as to have a width of 100 mm and a length of 100 mm. The sample was treated in an oven at 150 ° C. for 30 minutes, cooled to room temperature, and when placed on a flat plate, the height from the flat plate where the film edge was most raised from the flat plate was measured.
S: 0.03 mm or less A: More than 0.03 mm and 0.07 mm or less B: More than 0.07 mm and 0.11 mm or less C: More than 0.11 mm

(Reference Example 1) Emulsion (EM-10) containing composition (B-1) having acrylic resin (D) on the surface of alumina particles (B) and acrylic resin (C)
A normal acrylic resin reaction tank equipped with a stirrer, a thermometer, and a reflux condenser was charged with 100 parts of isopropyl alcohol as a solvent, heated and stirred, and maintained at 100 ° C.

  In this, 50 parts of nonadecyl methacrylate (n = 19) as (meth) acrylate (g′1) and 50 parts of isobonyl methacrylate having two rings as (meth) acrylate (g′2) were added for 3 hours. It dripped over. After completion of the dropwise addition, the mixture was heated at 100 ° C. for 1 hour, and then an additional catalyst mixed solution consisting of 1 part of t-butylperoxy-2-ethylhexaate was charged. Next, the mixture was heated at 100 ° C. for 3 hours and then cooled to obtain an acrylic resin (D).

  Further, 100 parts of isopropyl alcohol as a solvent was charged into a usual acrylic resin reaction tank equipped with a stirrer, a thermometer, and a reflux condenser, heated and stirred, and maintained at 100 ° C. As a (meth) acrylate (f'3) having a hydroxyl group, 40 parts of 2-hydroxyethyl acrylate, 20 parts of other ethyl (meth) acrylate, and 20 parts of methyl methacrylate were added dropwise thereto over 3 hours. After completion of the dropwise addition, the mixture was heated at 100 ° C. for 1 hour, and then an additional catalyst mixed solution consisting of 1 part of t-butylperoxy-2-ethylhexaate was charged. Next, the mixture was heated at 100 ° C. for 3 hours and then cooled to obtain an acrylic resin (C).

Alumina particles (B) (“NanoTek” Al ₂ O ₃ slurry (manufactured by C-I Kasei Co., Ltd., number average particle diameter: 30 nm)) and the acrylic resin (D) are sequentially added to an aqueous solvent, and dispersed by the following method. Thereafter, an acrylic resin (C) was added to obtain an emulsion (EM-1) containing a mixed composition (B-3) of the particles (B), the acrylic resin (D), and the acrylic resin (C) (see ((1) above). Method ii).)
The addition amount ratio (weight ratio) of the alumina particles (B), the acrylic resin (C), and the acrylic resin (D) was (B) / (C) / (D) = 45/46/9 (the weight ratio Was rounded off to the first decimal place). The dispersion treatment was performed by using a homomixer, and rotating at a peripheral speed of 10 m / s for 5 hours.

  The obtained composition (B-1) was centrifuged (Hitachi Koki Co., Ltd .: CS150NX) by centrifugation (rotation speed 3000 rpm, separation time 30 minutes), and alumina particles (B) were obtained. After the sediment (and the acrylic resin (C) adsorbed on the surface of the alumina particles (B)), the supernatant was removed and the sediment was concentrated to dryness. The concentrated and dried precipitate was analyzed by X-ray photoelectron spectroscopy (XPS). As a result, it was confirmed that the acrylic resin (C) was present on the surface of the alumina particles (B). In other words, the acrylic resin (C) is adsorbed and adhered to the surface of the alumina particles (B), and the obtained composition (B-1) applies the acrylic resin (C) to the surface of the alumina particles (B). It was found that the particles corresponded to particles having the same.

(Reference Example 2) Emulsion (EM-2) containing composition (B-1) having acrylic resin (D) on the surface of alumina particles (B) and acrylic resin (C)
Same as Reference Example 1 in which the addition ratio (weight ratio) of the alumina particles (B), the acrylic resin (C) and the acrylic resin (D) was (B) / (C) / (D) = 50/40/10. By the method described above, an emulsion (EM-2) containing the mixed composition (B-1) of the particles (B) and the acrylic resin (C) was obtained.

(Reference Example 3) Emulsion (EM-3) containing composition (B-1) having acrylic resin (D) on the surface of alumina particles (B) and acrylic resin (C)
Same as Reference Example 1 in which the addition ratio (weight ratio) of the alumina particles (B), the acrylic resin (C) and the acrylic resin (D) was (B) / (C) / (D) = 35/58/7. By the method described above, an emulsion (EM-3) containing the mixed composition (B-1) of the particles (B) and the acrylic resin (C) was obtained.

(Reference Example 4) Emulsion (EM-4) containing composition (B-1) having acrylic resin (D) on the surface of alumina particles (B) and acrylic resin (C)
Same as Reference Example 1 in which the addition ratio (weight ratio) of the alumina particles (B), the acrylic resin (C) and the acrylic resin (D) was (B) / (C) / (D) = 70/16/14. By the method described above, an emulsion (EM-4) containing the mixed composition (B-1) of the particles (B) and the acrylic resin (C) was obtained.

(Reference Example 5) Emulsion (EM-5) containing composition (B-1) having acrylic resin (D) on the surface of alumina particles (B) and acrylic resin (C)
Same as Reference Example 1 in which the addition ratio (weight ratio) of the alumina particles (B), the acrylic resin (C) and the acrylic resin (D) was (B) / (C) / (D) = 10/89/1. By the method described above, an emulsion (EM-5) containing the mixed composition (B-1) of the particles (B) and the acrylic resin (C) was obtained.

(Reference Example 6) Emulsion (EM-6) containing composition (B-2) having acrylic resin (D) on the surface of silicon oxide particles (B) and acrylic resin (C)
Acrylic resin (A) was applied to the surface of the particles (B) in the same manner as in Reference Example 1 except that an aqueous dispersion of colloidal silica (“Snowtech OL” manufactured by Nissan Chemical Industries, particle diameter 40 nm) was used as the alumina particles (B). An emulsion (EM-6) containing the composition (B-2) of the composition (B) having the composition (D) and the acrylic resin (C) was obtained.

  The properties and the like of the laminated films obtained in the following Examples and Comparative Examples are shown in the table.

(Example 1)
First, a resin composition 1 was prepared as follows.

(Resin composition)
The above emulsion was mixed with the aqueous solvent at the ratio shown in the table to obtain a resin composition 1.
Emulsion (EM-1) containing composition (B-3) having acrylic resin (D) on the surface of alumina particles (B) and acrylic resin (C): 100 parts by weight (laminated film)
Next, PET pellets substantially containing no particles (intrinsic viscosity: 0.63 dl / g) are sufficiently vacuum-dried, supplied to an extruder, melted at 285 ° C., extruded into a sheet shape from a T-shaped die, and squeezed. It was wound around a mirror casting drum having a surface temperature of 25 ° C. by the application of an electric voltage and cast to be cooled and solidified. This unstretched film was heated to 90 ° C. and stretched 3.1 times in the longitudinal direction to obtain a uniaxially stretched film (B film).

  Next, the resin composition 1 was applied to one surface of the uniaxially stretched film with a coating thickness of about 1 μm using a bar coat. Both ends in the width direction of the uniaxially stretched film coated with the resin composition were gripped with clips and led to a preheating zone in an oven. At an atmospheric temperature of 120 ° C., the resin composition was dried to form a resin layer. Subsequently, the film was continuously stretched 3.8 times in the width direction in a heating zone (stretching zone) at 120 ° C., and then subjected to a heat treatment in a heat treatment zone (heat setting zone) at 240 ° C. for 15 seconds to complete the crystal orientation. Furthermore, a relaxation step of 0.5% in the longitudinal direction was performed by reducing the gap between clips adjacent in the longitudinal direction of the film at 120 ° C. At the same time, the gap between the clips facing in the blade direction was reduced, thereby completing the 5% relaxation process in the width direction. Thereafter, the clips holding both ends in the width direction of the film were separated to take out the film from the oven, and both ends in the width direction were cut off to obtain a laminated film intermediate product having a width of 3500 mm.

  The obtained laminated film intermediate product was cut into a width of 1600 mm × 2 (both ends 150 mm × 2) with a slitter to obtain a laminated film roll. The thickness of the laminated film was 50 μm, and the thickness of the resin layer was 600 nm.

  The properties and the like of the obtained laminated film roll are shown in the table.

  It was excellent in transparency, scratch resistance and curl resistance.

(Example 2)
A laminated film was obtained in the same manner as in Example 1, except that the resin composition in the coating liquid was changed as described below. The properties and the like of the obtained laminated film are shown in the table.
Emulsion (EM-2) containing composition (B-3) having acrylic resin (D) on the surface of alumina particles (B) and acrylic resin (C): 100 parts by weight (Example 3)
A laminated film was obtained in the same manner as in Example 1, except that the resin composition in the coating liquid was changed as described below. The properties and the like of the obtained laminated film are shown in the table.
Emulsion (EM-3) containing composition (B-3) having acrylic resin (D) on the surface of alumina particles (B) and acrylic resin (C): 100 parts by weight (Examples 4, 5)
A laminated film was obtained in the same manner as in Example 1 except that the relaxation ratio in the width direction and the longitudinal direction in the relaxation step was changed. The properties and the like of the obtained laminated film are shown in the table.

(Examples 6 and 7)
A laminated film was obtained in the same manner as in Example 1 except that the heat treatment temperature in the heat treatment zone was changed. The properties and the like of the obtained laminated film are shown in the table.

(Examples 8 and 9)
A laminated film was obtained in the same manner as in Example 1, except that the stretching ratio in the width direction of the stretching zone was changed. The properties and the like of the obtained laminated film are shown in the table.

(Examples 10 and 11)
A laminated film was obtained in the same manner as in Example 1, except that the stretching ratio in the longitudinal direction of the unstretched film was changed. The properties and the like of the obtained laminated film are shown in the table.

(Examples 12 and 13)
A laminated film was obtained in the same manner as in Example 1, except that the roll width of the laminated film roll was changed. The properties and the like of the obtained laminated film are shown in the table.

(Comparative Example 1)
A laminated film was obtained in the same manner as in Example 1, except that the resin composition in the coating liquid was changed as described below. The properties and the like of the obtained laminated film are shown in the table.
Emulsion (EM-4) containing composition (B-3) having acrylic resin (D) on the surface of alumina particles (B) and acrylic resin (C): 100 parts by weight (Comparative Example 2)
A laminated film was obtained in the same manner as in Example 1, except that the resin composition in the coating liquid was changed as described below. The properties and the like of the obtained laminated film are shown in the table.
Emulsion (EM-5) containing composition (B-3) having acrylic resin (D) on the surface of alumina particles (B) and acrylic resin (C): 100 parts by weight (Comparative Example 3)
A laminated film was obtained in the same manner as in Example 1, except that the resin composition in the coating liquid was changed as described below. The properties and the like of the obtained laminated film are shown in the table.
Emulsion (EM-6) containing composition (B-3) having acrylic resin (D) on the surface of alumina particles (B) and acrylic resin (C): 100 parts by weight (Comparative Examples 4 and 5)
A laminated film was obtained in the same manner as in Example 1 except that the relaxation ratio in the width direction and the longitudinal direction in the relaxation step was changed. The properties and the like of the obtained laminated film are shown in the table.

(Comparative Example 6)
A laminated film was obtained in the same manner as in Example 1 except that the heat treatment temperature in the heat treatment zone was changed. The properties and the like of the obtained laminated film are shown in the table.

The laminated film roll of the present invention is excellent in transparency, scratch resistance, handling properties, and anti-blocking properties, and thus is preferably used as, for example, a hard coat film used for display applications or a hard coat film used for molding and decoration applications. be able to.

Claims (4)

A laminated film roll formed by winding a laminated film having a base material layer and a resin layer, wherein the resin layer contains 30% by weight or more and 50% by weight or less of alumina particles with respect to the resin layer. The shrinkage start temperature Ts (° C) at the shrinkage start temperature Ts (° C) at the two ends of the laminated film on the line extending in the width direction of the film, at a point located 100 mm inside from both ends, and at five points at the center in the width direction. The maximum change amount (difference between the highest shrinkage start temperature and the lowest shrinkage start temperature) is within 10 ° C, and any shrinkage start temperature Ts (° C) is 140 ° C or higher.
However, the shrinkage onset temperature Ts (° C.) is from 25 ° C. to 200 ° C. at a rate of 10 ° C./min by thermomechanical analysis (TMA) while applying a load of 40 g on the laminated film in the longitudinal direction of the laminated film. This is the temperature at the descent point observed on the hottest side, measured with increasing temperature. The laminated film roll according to claim 1, wherein the width of the laminated film roll is 250 mm or more and 2500 mm or less. The heat shrinkage in the longitudinal direction (MD direction) of the laminated film when heated at 150 ° C. for 60 minutes is located at both ends of the laminated film on a line extending in the width direction of the laminated film and 100 mm inside from both ends. 3. The laminated film roll according to claim 1, wherein all of the points and the five central points in the width direction are 0.0% or more and 1.0% or less. The heat shrinkage in the direction (TD direction) perpendicular to the longitudinal direction of the laminated film when heated at 150 ° C. for 60 minutes is such that both ends of the laminated film and both ends on a line extending in the width direction of the laminated film The laminated film roll according to any one of claims 1 to 3, wherein all of the points located 100 mm inward from the center and five points at the center in the width direction are 0.0% or more and 1.0% or less.