JP2009220316A - Laminated film and indicator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated film having excellent adhesiveness to the upper layer, e.g. a prism layer, and durability, e.g. water resistance, even in bad conditions, e.g. in hot water treatment. <P>SOLUTION: The laminated film 10 has a support 11 made of a polyester and a coating layer 14 formed on at least one side of the support 11. The coating layer 14 is disposed in position closest to the support 11 and consists of the first layer 12 comprising a polyester binder, a compound having a carbodiimide structure and a compound having an oxazoline group and the second layer 13 formed on the first layer 12 and containing a polyurethane resin. The content of the compound having a carbodiimide structure is 15-100 mass% to that of the polyester binder. The content of the compound having an oxazoline group is 10-65 mass% to that of the polyester binder. The first layer 12 is coated in a coating amount of 100-250 mg/m<SP>2</SP>. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laminated film excellent in adhesiveness and durability and a display device using the laminated film.

  A polyester film, particularly a biaxially oriented polyester film, has a support made of polyester (hereinafter simply referred to as “polyester support”), and exhibits excellent transparency, dimensional stability, chemical resistance, and low moisture absorption. It is widely used as various optical films. For example, base films such as prism sheets, antireflection sheets, light diffusion sheets, and hard coat sheets used in liquid crystal displays, IR absorption sheets, electromagnetic wave shielding sheets, toning sheets, antireflection sheets, antiglare sheets used in plasma displays It is used as a base film for sheets, hard coat sheets and the like.

  The base film used for the optical film as described above is required to have excellent transparency, and to a layer including a prism layer laminated thereon (hereinafter sometimes referred to as an upper layer). Excellent adhesion (easy adhesion) is required. However, it is difficult to directly bond the polyester support and the upper layer with sufficient strength. Therefore, generally, an application layer called an easy adhesion layer containing a material having high adhesiveness is provided on a polyester support.

For example, in Patent Document 1, a polyester resin and a carbodiimide compound are contained in the coating layer. Moreover, in patent document 2, the polyester resin and the acrylic resin are contained in the coating layer.
JP 2007-190817 A Japanese Patent No. 3773738

  However, the laminated film provided with the coating layer as in the above-mentioned patent document exhibits adhesiveness with the upper layer under a normal environment, but has poor adhesiveness under adverse conditions such as high heat and hot water treatment. May be.

  The present invention provides a laminated film and a display device that are excellent in adhesiveness with an upper layer and have durability such as water resistance and heat resistance even under adverse conditions such as high heat and hot water treatment. With the goal.

  In order to achieve the above object, the laminated film of the present invention is provided with a coating layer containing a polyester binder, a compound having a carbodiimide structure, and a compound having an oxazoline group on at least one surface of a support made of polyester. The compound having a carbodiimide structure is 15% by mass to 100% by mass with respect to the polyester binder, and the compound having an oxazoline group is 10% by mass to 65% by mass with respect to the polyester binder. And

The coating layer is provided in a first layer closest to the support, and includes a first layer containing the polyester binder, the compound having a carbodiimide structure, and the compound having an oxazoline group, and the first layer. It is preferable to consist of the 2nd layer which is provided on the top and contains a polyurethane resin. The first layer is preferably formed at a coverage of ^{100mg / m 2 ~250mg / m 2} .

  The laminated film of the present invention is used for the display device of the present invention.

  According to the present invention, a coating layer containing a polyester binder, a compound having a carbodiimide structure, and a compound having an oxazoline group is provided on at least one surface of a support made of polyester, and the compound having the carbodiimide structure is By making the compound having an oxazoline group 15% by mass to 100% by mass with respect to the polyester binder and 10% by mass to 65% by mass with respect to the polyester binder, the adhesiveness with the upper layer is excellent, and In addition, durability such as water resistance and heat resistance can be obtained even under adverse conditions such as high heat and hot water treatment.

  As shown in FIG. 1, the laminated film 10 of the present invention includes a support 11 made of polyester and a coating layer 14 formed on one surface of the polyester support. The coating layer 14 includes a first layer closest to the support 11 and a second layer provided on the first layer. The first layer 12 and the second layer 13 are both layers made of resin and containing a binder. In the present invention, the binder included in the first layer 12 is referred to as a first binder, and the binder included in the second layer 13 is referred to as a second binder.

[Polyester support]
The support 11 of the present invention is a polyester base film made of polyester. As the polyester, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, or the like can be used. Among these, polyethylene terephthalate is particularly preferable from the viewpoint of cost and mechanical strength. However, the polyester that can be used in the present invention is not particularly limited.

  In order to improve the mechanical strength, the support 11 is preferably stretched, and particularly preferably biaxially stretched. Although there is no restriction | limiting in particular in a draw ratio, 1.5-7 times are preferable, More preferably, it is about 2-5 times. In particular, biaxially stretched products that are stretched about 2 to 5 times in the vertical and horizontal directions are preferable. If the draw ratio is less than 1.5 times, sufficient mechanical strength cannot be obtained. Conversely, if it exceeds 7 times, it becomes difficult to obtain a uniform thickness.

  The thickness of the support 11 is 30 μm or more and 500 μm or less. More preferably, they are 100 micrometers or more and 300 micrometers or less. When the thickness is less than 30 μm, it is not preferable because the waist is lost and it becomes difficult to handle. On the other hand, when the thickness exceeds 500 μm, it is difficult to reduce the size and weight of the display device, and it is disadvantageous in terms of cost.

[First layer]
The first layer 12 of the present invention is a layer that is directly laminated on the support 11. This layer must contain a polyester binder, a compound having a plurality of carbodiimide structures, and a compound having an oxazoline group. This layer may further contain other binders, fine particles, a surfactant, an antistatic agent and the like as required.

  In the first binder of the present invention, a polymer such as (a) an acrylic resin, (b) a polyurethane resin, and (c) a rubber-based resin can be preferably used mainly with a polyester binder. In addition, as a polymer used as a 1st binder, what has a carboxyl group in a molecule | numerator is preferable.

    The polyester binder is a polyester resin binder which is a general term for polymers having an ester bond in the main chain, and is usually obtained by a reaction between a polycarboxylic acid and a polyol. Examples of the polycarboxylic acid include fumaric acid, itaconic acid, adipic acid, sebacic acid, terephthalic acid, and isophthalic acid. Examples of the polyol include ethylene glycol, propylene glycol, glycerin, and hexanetriol. The polyester resin and its raw materials are described, for example, in “Polyester Resin Handbook” (Eiichiro Takiyama, Nikkan Kogyo Shimbun, published in 1988).

  (A) Acrylic resin is a polymer containing acrylic acid, methacrylic acid and derivatives thereof as components. Specific examples include acrylic acid, methacrylic acid, methyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, acrylamide, acrylonitrile, hydroxyl acrylate, and the like as main components, and monomers copolymerizable therewith (for example, styrene, And polymers obtained by copolymerization of divinylbenzene and the like.

    Among the above, (b) polyurethane resin is a general term for polymers having a urethane bond in the main chain, and is usually obtained by reaction of polyisocyanate and polyol. Examples of the polyisocyanate include TDI, MDI, NDI, TODI, HDI, and IPDI. Examples of the polyol include ethylene glycol, propylene glycol, glycerin, and hexanetriol. As the isocyanate of the present invention, a polymer obtained by subjecting a polyurethane polymer obtained by the reaction of polyisocyanate and polyol to chain extension treatment to increase the molecular weight can also be used. The polyisocyanate, polyol, and chain extension treatment described above are described in, for example, “Polyurethane Resin Handbook” (edited by Keiji Iwata, Nikkan Kogyo Shimbun, published in 1987).

  In the present invention, (c) rubber-based resin refers to diene-based synthetic rubber among synthetic rubbers. Specific examples include polybutadiene, styrene-butadiene copolymer, styrene-butadiene-acrylonitrile copolymer, styrene-butadiene-divinylbenzene copolymer, butadiene-acrylonitrile copolymer, and polychloroprene. The rubber-based resin is described in, for example, “Synthetic Rubber Handbook” (edited by Amane Kambara, published by Asakura Shoten Co., Ltd., 1967).

  Moreover, as said 1st binder, said polymer may be dissolved and used in an organic solvent, and an aqueous dispersion may be used. However, since the environmental load is small, it is preferable to perform aqueous coating using an aqueous dispersion. A commercially available polymer may be used as the aqueous dispersion. For example, Superflex 830, 460, 870, 420, 420NS (trade name: polyurethane manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Bondic 1370NS, 1320NS (trade name: Large) Polyurethane manufactured by Nippon Ink Chemical Co., Ltd.), Jurimer ET325, ET410, SEK301 (trade name: Nippon Pure Chemicals Co., Ltd. acrylic), Boncoat AN117, AN226 (trade name: Dainippon Ink Chemical Co., Ltd. acrylic) , Luck Star DS616, DS807 (trade name: Dainippon Ink and Chemicals Co., Ltd. styrene-butadiene rubber), Nippon LX110, LX206, LX426, LX433 (trade name: Nippon Zeon Co., Ltd. styrene-butadiene rubber), Nippon LX513, LX1551, L 550, LX1571 (trade name: Acrylonitrile-butadiene rubber manufactured by Nippon Zeon Co., Ltd.), Finetex Es650, Es2200 (trade name: polyester manufactured by Dainippon Ink & Chemicals, Inc.), Vironal MD1400, MD1480 (trade name: Toyobo ( Polyester Co., Ltd.), plus coat Z687 (trade name: Polyester manufactured by Kyoyo Chemical Co., Ltd.), and the like.

  As the polymer used as the first binder, one type may be used alone, or two or more types may be mixed and used as necessary. The molecular weight of the polymer used as the first binder is not particularly limited, but it is usually preferable to use a polymer having a weight average molecular weight of about 3000 to 1000000. However, when the polymer having a weight average molecular weight of less than 3000 is used, the strength of the first layer 12 may be insufficient. On the other hand, when the polymer having a weight average molecular weight of more than 1000000 is used, the surface state of the first layer 12 is poor. There is.

  As the “compound having a plurality of carbodiimide structures in the molecule” (hereinafter referred to as a carbodiimide compound as appropriate) used in the present invention, any compound having a plurality of carbodiimide groups in the molecule can be used without particular limitation. be able to. Polycarbodiimide is usually synthesized by condensation reaction of organic diisocyanate, but the organic group of the organic diisocyanate used in this synthesis is not particularly limited, either aromatic or aliphatic, or a mixture thereof It can be used. However, aliphatic systems are particularly preferred from the viewpoint of reactivity. As the synthetic raw material, organic isocyanate, organic diisocyanate, organic triisocyanate and the like are used.

  As examples of organic isocyanates, aromatic isocyanates, aliphatic isocyanates, and mixtures thereof can be used. Specifically, 4,4'-diphenylmethane diisocyanate, 4,4-diphenyldimethylmethane diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, cyclohexane Diisocyanate, xylylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,3-phenylene diisocyanate, etc. are used, and organic monoisocyanates include isophorone isocyanate, phenyl isocyanate. Cyclohexyl isocyanate, butyl isocyanate, naphthyl isocyanate and the like are used. Moreover, the carbodiimide type compound which can be used for this invention is also available as commercial items, such as carbodilite V-02-L2 (brand name: Nisshinbo Co., Ltd. product).

  It is preferable to add the carbodiimide type compound of this invention in 15-100 mass% with respect to a 1st binder, More preferably, it is adding in 20-75 mass%. By adding the carbodiimide-based compound within the above range, the adhesion with the support 11 can be improved. On the other hand, when the addition amount is less than 15% by mass, the adhesion to the support 11 is deteriorated, and when the first layer 12 contains fine particles, prevention of fine particle peeling may be insufficient. There is. On the other hand, when the addition amount exceeds 100% by mass, there is no harmful effect, but the cost is excessive.

  Examples of the compound having an oxazoline group used in the present invention include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2- Oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline and the like, and one or two of these Mixtures of the above can be used. The compound having an oxazoline group used in the present invention is also available as a commercial product such as Epocross K2020E (trade name: manufactured by Nippon Shokubai Co., Ltd.).

  It is preferable to add the compound which has an oxazoline group of this invention in the range of 10-65 mass% with respect to a 1st binder, More preferably, it is adding in the range of 12-63 mass%. By adding a compound having an oxazoline group within the above range, high adhesiveness can be maintained without losing adhesiveness to the support 11 even under adverse conditions such as under high heat and hydrothermal treatment. Can do. On the other hand, when the addition amount is less than 10% by mass, the water resistance is poor, and the adhesiveness with the support 11 is lost in a high humidity environment. On the other hand, when the addition amount exceeds 65% by mass, liquid aggregation occurs.

  Moreover, you may use various additives, such as microparticles | fine-particles and surfactant other than the above, for the 1st layer 12 according to a use. As the fine particles that can be used in the first layer 12 of the present invention, either organic or inorganic fine particles can be used. For example, polymer fine particles such as polystyrene, polymethyl methacrylate, silicone resin, and benzoguanamine resin, and inorganic fine particles such as silica, calcium carbonate, magnesium oxide, and magnesium carbonate can be used. Among these, polystyrene, polymethyl methacrylate, and silica are preferable from the viewpoint of the effect of improving the slipperiness and cost.

The average particle size of the fine particles used in the present invention is preferably from 0.1 μm to 12 μm, more preferably from 0.2 μm to 9 μm. When the average particle size of the fine particles is less than 0.1 μm, the effect of improving the slipping property is insufficient. On the other hand, when the average particle size exceeds 12 μm, the display quality of the display device may be deteriorated. Further, the amount of the fine particles of the present invention varies depending on the average particle diameter, but is preferably 0.1 mg / m ² or more and 30 mg / m ² or less, more preferably 0.5 mg / m ² or more and 20 mg / m. ² or less. If the addition amount of the fine particles is less than 0.1 mg / m ² , the effect of improving the slip property may be insufficient. On the other hand, if the addition amount exceeds 30 mg / m ² , the transparency is lowered and the display of the display device is reduced. There is a risk of degrading quality. The average particle size of the fine particles referred to in the present invention is the particle size obtained for any 50 fine particles when the diameter of a circle having the same area as the fine particles when the fine particles were photographed with a scanning electron microscope was used as the particle size. Mean diameter.

Examples of the surfactant that can be used for the first layer 12 include known anionic, nonionic, and cationic surfactants. The surfactant is described in, for example, “Surfactant Handbook” (Nishi Ichiro, Imai Junichiro, Sho Kasai edited by Sangyo Kasho Co., Ltd., 1960). Further, the addition amount of the surfactant is preferably 0.1 mg / m ² or more and 30 mg / m ² or less, more preferably 0.2 mg / m ² or more and 10 mg / m ² or less. If the addition amount of the surfactant is less than 0.1 mg / m ² , repelling may occur. On the other hand, if it exceeds 30 mg / m ² , the surface state of the first layer 12 may be deteriorated.

An antistatic agent can also be used for the first layer 12. The type of the antistatic agent is not particularly limited. For example, an electron transmission polymer such as polyaniline or polypyrrole, an ion transmission polymer having a carboxyl group or a sulfonic acid group in the molecular chain, conductive fine particles, etc. Is mentioned. Among these, the conductive tin oxide fine particles described in JP-A-61-20033 can be preferably used from the viewpoints of conductivity and transparency. The addition amount of the antistatic agent is preferably added so that the surface resistivity of the first layer 12 measured in an atmosphere of 25 ° C. and 30% RH is 1 × 10 ⁵ Ω or more and 1 × 10 ¹³ Ω or less. If the surface resistivity is less than 1 × 10 ⁵ Ω, the addition amount of the antistatic agent increases and the transparency of the laminated film may be lowered. If the surface resistivity exceeds 1 × 10 ¹³ Ω, the antistatic effect is insufficient. On the other hand, there is a risk of inconvenience such as dust adhering.

  The thickness of the first layer 12 is set to be 10 nm or more and 500 nm or less in order to develop easy adhesion to the support 11. More preferably, the thickness of the first layer 12 is 30 nm or more and 150 nm or less. If the film thickness of the first layer 12 is less than 10 nm, the adhesion to the polyester support becomes insufficient, while if the film thickness exceeds 500 nm, the surface state may be deteriorated.

The coating amount of the first layer 12 is preferably in the range of ^{100mg / m 2 ~250mg / m 2} , more preferably in the range of ^{120mg / m 2 ~230mg / m 2} . By setting the coating amount of the first layer 12 within the above range, the adhesion with the support 11 can be kept constant without causing coating unevenness. On the other hand, when the coating amount of the first layer 12 is less than 100 mg / m ² , the adhesive material such as a polyester binder is insufficient, and thus the adhesiveness with the support 11 is weakened. On the other hand, when the coating amount of the first layer 12 exceeds 250 mg / m ² , coating unevenness occurs, and the optical characteristics are affected.

[Second layer]
The second layer 13 is a layer coated at a position farther from the support 11 than the first layer 12. The second layer 13 is preferably the outermost layer of the laminated film 10. The second layer 13 includes a predetermined second binder. In addition to the binder, the second layer 13 may contain additives such as fine particles, a slip agent, a surfactant, and an antistatic agent as necessary. .

  In the present invention, a resin selected from an acrylic resin, a polyurethane resin, and a rubber resin is used as the second binder. Note that the details of these resins are the same as those described in the description of the first binder, and a description thereof is omitted here. Among these, it is particularly preferable to use a polyurethane resin from the viewpoint of adhesiveness in addition to excellent transparency, and as the polymer used as the second binder, a polymer having a carboxyl group in the molecule is particularly preferable.

  As the second binder, the above polymer may be used by dissolving in an organic solvent, or an aqueous dispersion may be used. However, since the environmental load is small, it is preferable to perform aqueous coating using an aqueous dispersion. As the aqueous dispersion, the aforementioned commercially available polymer may be used.

  One type of polymer used as the second binder may be used alone, or two or more types may be mixed and used as necessary. Although there is no restriction | limiting in particular in the molecular weight of the polymer used as a 2nd binder, The thing of about 3000-1 million is usually preferable in a weight average molecular weight. When the weight average molecular weight is less than 3,000, the strength of the coating layer may be insufficient, and when the weight average molecular weight exceeds 1,000,000, the coated surface may be poor.

  You may make the 2nd layer 13 contain an additive suitably according to a use. About the kind and quantity of microparticles | fine-particles, surfactant, and antistatic agent which can be used for the 2nd layer 13, the thing similar to the above-mentioned 1st layer can be used. The details of the various additives are the same as those of the first layer 12, and thus the description thereof is omitted.

When a slipping agent is used as an additive for the second layer 13, the type of the slipping agent is not particularly limited, but as a slipping agent that can be suitably used, for example, a synthetic or natural wax, a silicone compound, Compound represented by R—O—SO ₃ M (where R represents a substituted or unsubstituted alkyl group (C _n H _{2n + 1} —; n is an integer of 3 to 20), M represents a monovalent metal atom) Etc.

In addition, specific examples of the slip agent include cellosol 524, 428, 732-B, 920, B-495, hydrin P-7, D-757, Z-7-30, E-366, F-115, D-336, D-337, Polylon A, 393, H-481, Himicron G-110F, 930, G-270 (trade name: manufactured by Chukyo Yushi Co., Ltd.), Chemipearl W100, W200, W300, W400, Wax type such as W500, W950 (trade name: manufactured by Mitsui Chemicals), KF-412, 413, 414, 393, 859, 8002, 6001, 6002, 857, 410, 910, 851, X-22 162A, X-22-161A, X-22-162C, X-22-160AS, X-22-164B, X-22-164C, X-22-170B, X-2 -800, X-22-819, X- 22-820, X-22-821: and silicone, such as (trade name by Shin-Etsu Chemical Co., _{Ltd.), C 16 H 33 -O-} SO 3 Na, C ₁₈ H _{37 -O-SO} 3 Na compound represented by formula such as and the like. The addition amount of these slip agent is preferably to 0.1 mg / ^{m 2} or more 50 mg / ^{m 2} or less, more preferably 1 mg / ^{m 2} or more 20 mg / ^{m 2} or less. However, when the addition amount is less than 0.1 mg / m ² , the slip property of the second layer 13 may be insufficient. On the other hand, when it exceeds 50 mg / m ² , the planar shape of the second layer 13 may be obtained. May get worse.

  Although there is no restriction | limiting in particular in the thickness of the 2nd layer 13, In order to implement | achieve easy adhesiveness, ensuring excellent transparency, it is preferable that they are 10 nm or more and 5000 nm or less, More preferably, they are 20 nm or more and 1500 nm or less. . If the thickness of the second layer 13 is less than 10 nm, the adhesiveness with the upper layer may be insufficient. On the other hand, if the thickness exceeds 5000 nm, the surface state may be deteriorated.

  When forming the coating layer 14, it is preferable to provide the first layer 12 and the second layer 13 by coating. However, the method for forming the coating layer 14 is not particularly limited, and a known method such as bar coater coating or slide coater coating can be used. At this time, the first layer 12 and the second layer 13 may be formed by applying the same method or different methods. Moreover, when forming the 2nd layer 13, you may dry after apply | coating simultaneously with the 1st layer 12, and you may apply | coat after applying and drying the 1st layer 12.

  When applying both the first layer 12 and the second layer 13, a solvent (coating solvent) can be used. As the coating solvent, water, toluene, methyl alcohol, isopropyl alcohol, methyl ethyl ketone, and the like, and aqueous and organic solvent based coating solvents such as a mixed system thereof can be used. Among these, the method using water as a coating solvent is preferable in view of cost and ease of production. In addition, the coating solvent used for the 1st layer 12 and the 2nd layer 13 may be the same, and may differ.

  Moreover, application | coating may be performed after extending | stretching to a uniaxial direction, and may be performed after extending biaxially. However, in order to enable recovery of the base ear after lateral stretching, it is preferable to apply after biaxial stretching. The coating layer 14 may be formed not only on one side but also on the other side of the support 11.

    The laminated film of the present invention can be used as an optical film for use in liquid crystal displays, plasma displays, organic EL displays, and CRT displays. About these display devices, for example, “Display Advanced Technology” (published by Chizuka Tani, Kyoritsu Publishing Co., Ltd. 1998), “EL, PDP, LCD Display” (Toray Research Center Co., Ltd. issued in 2001), It is described in detail in “Color LCD” (Shunsuke Kobayashi, Sangyo Tosho Publishing Co., Ltd., published in 1990).

  In addition, an optical sheet having a laminated film obtained by the present invention and at least one of a prism layer, an antireflection layer, a light diffusion layer, an antiglare layer, and a hard coat layer exhibits excellent optical properties. Specific examples of these include prism sheets, antireflection sheets, light diffusion sheets, hard coat sheets, plasma display IR absorption sheets, electromagnetic wave shield sheets, toning sheets and the like used in liquid crystal displays. For example, In addition to the literature, it is described on page 74 of the August 2002 issue of Electric Journal.

  Hereinafter, the laminated film of the present invention will be specifically described with reference to the following Examples 1 to 6 and Comparative Examples 1 to 6. Each example and comparative example do not limit the present invention.

[Example 1]

  A laminated film support was formed by the following procedure. First, a polyethylene terephthalate (hereinafter referred to as PET) resin having an inherent viscosity of 0.66 polycondensed using Ge as a catalyst was dried to a moisture content of 50 ppm or less and melted in an extruder having a heater temperature of 280 to 300 ° C. . The melted PET resin was discharged from a die part onto a chill roll electrostatically applied to obtain an amorphous base. The obtained amorphous base was stretched 3.3 times in the base traveling direction, and then stretched 3.8 times in the width direction to obtain a support having a thickness of 100 μm.

The both sides of the support having a thickness of 100 μm formed as described above are conveyed at a conveyance speed of 105 m / min, subjected to corona discharge treatment under the condition of 730 J / m ² , and then the following [First layer coating solution] is bar coated. It was applied by the method. And after drying this at 180 degreeC for 1 minute and forming a 1st layer, the coating amount was set to 96.25 mg / m < ² > on both 1st layers continuously, and the following [2nd layer coating liquid] was barred. After coating by the coating method, the laminated film in which the first layer and the second layer were coated on both surfaces of the support was obtained by drying at 170 ° C. for 1 minute.
[First layer coating solution]
45.1 parts by mass of polyester binder (amount applied: 80 mg / m ² , ratio to 100 parts by mass of polyester binder: 100%)
(Plus Coat Z687, solid content 25%, manufactured by Kanayo Chemical Co., Ltd.)
Carbodiimide compound 15.8 parts by mass (coating amount: 45 mg / m ² , ratio to 100 parts by mass of polyester binder: 56.3%)
(Carbodilite V-02-L2 solid content 40% by Nisshinbo Co., Ltd.)
7.0 parts by mass of oxazoline compound (amount applied: 20 mg / m ² , ratio to 100 parts by mass of polyester binder: 25%)
(Nippon Shokubai Co., Ltd. Epocross K2020E solid content 40%)
Surfactant A 15.5 parts by mass (amount applied: 1.1 mg / m ² , ratio to 100 parts by mass of polyester binder: 1.4%)
(1% aqueous solution of NAROACTY CL-95 manufactured by Sanyo Chemical Industries)
Surfactant B 12.7 parts by mass (coating amount: 0.9 mg / m ² , ratio to 100 parts by mass of polyester binder: 1.1%)
(1% aqueous solution of Rapisol B-90 manufactured by Nippon Oil & Fats Co., Ltd.)
Add so that the total amount of distilled water is 1000 parts by mass [2nd layer coating solution]
22.8 parts by mass of polyurethane binder (amount applied: 61.5 mg / m ² )
(Orestar UD-350, solid content 38%, manufactured by Mitsui Chemicals, Inc.)
Acrylic binder 2.6 parts by mass (application amount: 5 mg / m ² )
(EM48D, solid content 27.5%, manufactured by Daicel Chemical Industries, Ltd.)
Carbodiimide compound 4.7 parts by mass (coating amount: 13.35 mg / m ² )
(Nisshinbo Co., Ltd. Carbodilite V-02-L2 solid content 40%)
Surfactant A 15.5 parts by mass (application amount: 1.1 mg / m ² )
(1% aqueous solution of NAROACTY CL-95 manufactured by Sanyo Chemical Industries)
Surfactant B 12.7 parts by mass (coating amount: 0.9 mg / m ² )
(1% aqueous solution of Rapisol B-90 manufactured by Nippon Oil & Fats Co., Ltd.)
Matting agent A 3.5 parts by mass (application amount: 10 mg / m ² )
(Nissan Chemical Industry Co., Ltd. Snowtex XL solid content 40.5%)
Matting agent B 1.6 parts by mass (application amount: 1.1 mg / m ² )
(Nippon Aerosil Co., Ltd. Aerosil OX-50 aqueous dispersion solid content 10%)
1.6 parts by weight of slip agent (application amount: 3.3 mg / m ² )
(Chankyo Oil Co., Ltd. Carbana Wax Dispersion Cellosol 524 Solid 30%)
Add distilled water to 1000 parts by mass

[Example 2]
The same as Example 1 except that the oxazoline compound in the first layer coating solution of Example 1 was changed to 3.5 parts by mass (coating amount: 10 mg / m ² , ratio to 100 parts by mass of polyester binder: 12.5%). .

[Example 3]
Example 1 except that the oxazoline compound of the first layer coating solution of Example 1 was changed to 17.5 parts by mass (coating amount: 50 mg / m ² , ratio to 100 parts by mass of polyester binder: 62.5%). .

[Example 4]
The same procedure as in Example 1 was conducted, except that the carbodiimide compound in the first layer coating solution of Example 1 was changed to 5.6 parts by mass (coating amount: 16 mg / m ² , ratio to 100 parts by mass of polyester binder: 20%). .

[Example 5]
The same procedure as in Example 1 was followed, except that the carbodiimide compound in the first layer coating solution of Example 1 was changed to 28.1 parts by mass (coating amount: 80 mg / m ² , ratio to 100 parts by mass of polyester binder: 100%). .

[Example 6]
The polyester binder of the first layer coating liquid of Example 1 was added to 73.3 parts by mass (coating amount: 130 mg / m ² , ratio to 100 parts by mass of polyester binder: 100%). The carbodiimide compound was 24.6 parts by mass (coating amount: 70 mg / m ² , the ratio to 100 parts by mass of the polyester binder: 53.8%), and 12.3 parts by mass of the oxazoline compound of the first layer coating solution of Example 1 ( Application amount: 35 mg / m ² , ratio to 27 parts by mass of polyester binder: 27%)

[Comparative Example 1]
Example 1 was changed except that the oxazoline compound in the first layer coating solution of Example 1 was changed to 1.8 parts by mass (coating amount: 5 mg / m ² , ratio to 100 parts by mass of polyester binder: 6.3%). .

[Comparative Example 2]
The carbodiimide compound of the first layer coating solution of Example 1 is 5.6 parts by mass (coating amount: 16 mg / m ² , ratio to 100 parts by mass of the polyester binder: 20%). The procedure was the same as Example 1 except that the oxazoline compound was changed to 24.5 parts by mass (coating amount: 70 mg / m ² , ratio to 100 parts by mass of the polyester binder: 87.5%).

[Comparative Example 3]
The same procedure as in Example 1 was conducted except that the carbodiimide compound in the first layer coating solution of Example 1 was changed to 3.5 parts by mass (coating amount: 10 mg / m ² , ratio to 100 parts by mass of polyester binder: 12.5%). .

[Comparative Example 4]
The carbodiimide compound of the first layer coating solution of Example 1 was 28.1 parts by mass (coating amount: 80 mg / m ² , ratio to 100 parts by mass of polyester binder: 100%), and 1.8 parts by mass of oxazoline compound (coating). Amount: 5 mg / m ² , ratio to 100 parts by mass of polyester binder: 6.3%).

[Comparative Example 5]
The polyester binder of the first layer coating liquid of Example 1 is 28.2 parts by mass (coating amount: 50 mg / m ² , ratio to 100 parts by mass of polyester binder: 100%). The carbodiimide compound was 9.5 parts by mass (coating amount: 27 mg / m ² , the ratio with respect to 100 parts by mass of the polyester binder: 54%), and the oxazoline compound of the first layer coating solution of Example 1 was 4.2 parts by mass ( Application amount: 12 mg / m ² , ratio to the polyester binder 100 parts by mass: 24%)

[Comparative Example 6]
The polyester binder of the first layer coating solution of Example 1 was added to 81.7 parts by mass (coating amount: 145 mg / m ² , ratio to 100 parts by mass of polyester binder: 100%). The carbodiimide compound was 28.1 parts by mass (coating amount: 80 mg / m ² , the ratio to 100 parts by mass of the polyester binder: 55.2%), and 12.6 parts by mass of the oxazoline compound of the first layer coating solution of Example 1 ( Application amount: 36 mg / m ² , ratio to 100 parts by mass of polyester binder: 24.8%)

[Evaluation]
The following evaluation was performed about the laminated | multilayer film obtained by the said Examples 1-6 and Comparative Examples 1-6.

[Evaluation of adhesion]
A UV curable resin (Desolite Z7410B) manufactured by JSR was applied to the laminated film so that the dry film thickness was 5 μm. Next, 11 scratches were formed in each of the vertical and horizontal razors with a single-blade razor to form 100 squares, and then a polyester adhesive tape (NO31B) was attached. Then, after the tape was rubbed with an eraser and completely adhered, the height of the adhesion strength with the UV curable resin was determined from the following A to E by obtaining the number of squares peeled off in a 90-degree direction with respect to the horizontal plane. Evaluation was made in the following five stages.
A: When there is no peeling B: When the number of peeled squares is 1 or more and less than 5 C: When the number of peeled squares is 5 or more and less than 15 D: When the number of peeled squares is 15 or more and less than 30 E: When the number of peeled cells is 30 or more, the above A and B are at a level that does not cause a problem on the product.

[Evaluation of water adhesion]
A UV curable resin (Desolite Z7410B) manufactured by JSR was applied to the laminated film so that the dry film thickness was 5 μm. The laminated film coated with the UV curable resin was immersed in hot water at 100 ° C. for 10 minutes, and then the water was wiped off and left in an environment of 25 ° C. and 60% RH for 3 hours or more. Then, the water-resistant adhesiveness was evaluated in five stages of A to E in the same manner as the tape adhesion evaluation.

[Surface evaluation method]
Place the sample coated with black paint on the back of the laminated film with black paint and the sample not treated with black paint on a desk with a black doskin cloth attached, with the coating layer surface facing up, and a milky white acrylic plate The surface of the coating layer was irradiated with diffused light from a fluorescent lamp. And the reflected light reflected on the coating layer surface was observed visually, and the coating nonuniformity was judged on the following three-step criteria of AC.
A: Coating unevenness was not visually confirmed in both the blackened sample and the untreated sample.
B: Coating unevenness can be visually confirmed in the blackened sample, but not in the untreated sample.
C: Coating unevenness was visually confirmed in both the blackened sample and the untreated sample.
In addition, said A and B are a level which does not have a problem on a product.

[Liquid aggregation state]
The state of the aggregates when the coating solution was applied to a transparent PET base with a # 5 hand-painted bar was visually evaluated according to the following three-stage criteria AC.
A: There was no aggregate.
B: Although there were very small aggregates, there was almost no problem on the product.
C: Aggregates could be clearly confirmed.

表１の「塗布量」は各実施例及び比較例で使用する素材の塗布量（ｍｇ／ｍ^２）を、「合計塗布量」は各実施例及び比較例で使用する素材の合計の塗布量（ｍｇ／ｍ^２）を、「質量％」はポリエステルバインダー１００質量部に対する比率を示している。 Table 1 shows the production conditions of the above Examples and Comparative Examples and the evaluation results thereof.

“Coating amount” in Table 1 is the coating amount (mg / m ² ) of the material used in each example and comparative example, and “Total coating amount” is the total coating amount of the material used in each example and comparative example. “Mass%” of (mg / m ² ) indicates a ratio with respect to 100 parts by mass of the polyester binder.

  As shown in Table 1, in Examples 1 to 6, although the adhesiveness, water-resistant adhesiveness, surface state, and liquid aggregation state were slightly different depending on the mass of the binder and the compound, all showed good evaluation results. .

  On the other hand, compared with Examples 1-6, since the mass% of the carbodiimide compound with respect to the polyester binder was low in the comparative example 3, not only adhesiveness but water-resistant adhesiveness was not good. Moreover, in Comparative Examples 1 and 4, compared with Examples 1-6, since the mass% of the oxazoline compound with respect to the polyester binder was low, water-resistant adhesiveness was not good. Moreover, in the comparative example 2, compared with Examples 1-6, the mass% of the oxazoline compound with respect to a polyester binder is large. Therefore, as in Examples 1 to 6, while water-resistant adhesion was good, liquid aggregates were generated.

  Moreover, in the comparative example 5, since the total application amount was small compared with Examples 1-6, adhesive materials, such as a polyester binder, were insufficient, and adhesiveness and water-resistant adhesiveness were not good. Further, in Comparative Example 6, since the total application amount was large as compared with Examples 1 to 6, application unevenness occurred and the surface condition deteriorated.

  Moreover, on the laminated film produced in each Example 1-6, when the light-diffusion layer was formed and the light-diffusion sheet was produced according to Example 1 described in Unexamined-Japanese-Patent No. 2001-324609, lamination | stacking was carried out. Adhesiveness between the film and the light diffusion layer was practically satisfactory, and a light diffusion sheet having excellent optical characteristics could be obtained.

Moreover, according to Example 1 described in Unexamined-Japanese-Patent No. 2001-114831 on the laminated film produced in each Example 1-6, the 25-micrometer-thick photocurable resin composition was apply | coated by the bar-coat method. After that, a prototype with a very small prismatic pattern (prism angle 90 degrees, prism pitch 50 μm, manufactured by Fuji Photo Film Co., Ltd.) was placed and left in an oven at 80 ° C. for 3 minutes. After that, using a metal halide lamp as a light source from the coating layer side, UV irradiation of 1.0 J / cm ² is performed by a UV irradiation device with an irradiation intensity of 250 mW / cm ² , and further, the prototype with a microscopic prism-like pattern is separated, When a prism sheet was produced, the adhesive property between the laminated film and the prism layer was practically satisfactory, and a prism sheet excellent in optical characteristics could be obtained.

  Moreover, according to the Example described in Unexamined-Japanese-Patent No. 2001-323087 on the laminated film produced in each Example 1-6, the active energy ray hardening layer (hard-coat layer) coating liquid was applied by the bar coat method. After coating so that the dry film thickness becomes 8 μm, this was cured by ultraviolet irradiation to form a hard coat layer to produce a hard coat sheet. The adhesion between the laminated film and the hard coat layer was A hard coat sheet having good optical properties was obtained.

In addition, a hard coat layer, a silver colloid layer, and an antireflection layer were laminated in this order on the laminated film produced in each of Examples 1 to 6 according to Example 1 described in JP-A-2002-098803. When an antireflection sheet was produced, the adhesion between the laminated film and the hard coat layer was good, and an antireflection sheet excellent in optical properties could be obtained. The coating thickness of the hard coat layer was 12 μm, the coating amount of the silver colloid layer was 70 mg / m ^2, and the coating thickness of the antireflection layer was 85 nm.

It is principal part sectional drawing of a laminated | multilayer film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Laminated film 11 Support body 12 1st layer 13 2nd layer 14 Application layer

Claims (4)

A coating layer containing a polyester binder, a compound having a carbodiimide structure, and a compound having an oxazoline group is provided on at least one surface of a support made of polyester,
The compound having a carbodiimide structure is 15% by mass to 100% by mass with respect to the polyester binder, and the compound having an oxazoline group is 10% by mass to 65% by mass with respect to the polyester binder. A laminated film.   The coating layer is provided on the first layer closest to the support, and includes a first layer containing the polyester binder, the compound having a carbodiimide structure, and the compound having the oxazoline group, and the first layer. The laminated film according to claim 1, wherein the laminated film is formed on a second layer containing a polyurethane resin. The laminated film of claim 2 wherein said first layer being formed by coating amount of ^{100mg / m 2 ~250mg / m 2} .   A display device comprising the laminated film according to claim 1.

Images