JPH1044352A - Laminated film - Google Patents

Abstract

(57) Abstract: A polyalkylene naphthalate copolymer containing sulfonic acid and / or a salt thereof is provided on one surface of a laminated film provided with an ultraviolet absorbing layer on at least one surface of a thermoplastic film. A laminated film, comprising a layer having a main component laminated. The laminated film of the present invention is excellent in transparency, weather resistance, anti-fogging property, and dripping property, and is required for these functions, for example, agricultural green house, coating for indoor and outdoor building materials. Materials, indoor and outdoor overlays (display materials, illuminated signs, etc.), white boards, window coverings (buildings, vehicles, etc.)
Can be suitably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film, and more particularly, to a laminated film having excellent weather resistance, transparency, anti-fogging property, and dripping property.

[0002]

2. Description of the Related Art Conventionally, as a means for imparting weather resistance to a thermoplastic film, an ultraviolet absorbent is kneaded into a polyester film, or an ultraviolet absorbent is mixed in an acrylic resin, and the resultant is applied to the surface of the polyester film and dried. (Japanese Patent Publication No. 4-2101) and a polyethylene terephthalate film in which a layer containing metal oxide particles having an ultraviolet absorbing ability or an ultraviolet shielding ability is laminated on the surface thereof (JP-A-7-223293). Japanese Patent Application Laid-Open No. 53-40627), and those in which the refractive index and density of a polyethylene terephthalate film are in specific ranges. Further, a specific acrylic resin layer is provided on the opposite side of the surface provided with the ultraviolet absorbing layer or on one side of the base film containing the ultraviolet absorbing agent for the purpose of imparting anti-fog properties (Japanese Patent Application Laid-Open No. 63-153134). Japanese Patent Application Laid-Open No. 61-53038), and those provided with a layer composed of an alumina sol or a silica sol and a surfactant.

[0003]

However, the above-mentioned prior art has the following problems. In other words, the kneading of an ultraviolet absorber is effective for the so-called elongation degradation of the polyester film itself due to the weather resistance, but the deterioration of the surface layer is promoted due to insufficient weather resistance of the film surface, and the surface has cracks. This causes a problem that haze increases and transparency decreases. When a layer containing an ultraviolet absorber is provided on one side, the weather resistance of that surface is improved, but the other surface is inferior in weather resistance. Therefore, when it is provided on both sides, there is a defect that the antifogging property and the dropping property when spread on an agricultural house or the like become insufficient, and fogging occurs. The inner surface of the house when stretched to provide anti-fogging properties is subjected to anti-fog processing, but this layer does not have weather resistance, so when exposed to ultraviolet rays in the situation of opening and closing the house, the inner surface deteriorates. There are problems that arise. The present invention improves the above-mentioned drawbacks, that is, provides a laminated film having excellent weather resistance, and excellent in antifogging property, flowability and weather resistance of the inner surface when spread.

[0004]

The present invention relates to a polyalkylene naphthalate containing a sulfonic acid and / or a salt thereof on one side of a laminated film provided with an ultraviolet absorbing layer on at least one side of a thermoplastic film. The main feature is a laminated film characterized by laminating layers mainly composed of a polymer.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic film referred to in the present invention is a general term for a film which is melted or softened by heat and is not particularly limited, but typical examples are polyester films, polyolefins such as polypropylene and polyethylene. Films, polyamide films typified by nylon, polyvinyl chloride films, polyurethane films, polycarbonate films, acrylic films, fluorine films and the like can be used. Of these, in recent years, in many cases, polyester films are used for agricultural greenhouses and building material surface coating films due to their mechanical strength, dimensional stability, transparency, and the like.

In the present invention, a polyester film will be described below as a preferred example of the thermoplastic film. The polyester film is a general term for a polymer film having an ester bond as a main bonding chain, and particularly preferable polyester films are polyethylene terephthalate film, polyethylene-2,6-naphthalate film, polybutylene terephthalate film, Polybutylene-2,6-naphthalate film and the like can be used, and among these, polyethylene terephthalate film and polyethylene-2,6-naphthalate film are most preferable in terms of quality and economy. In particular, a polyethylene-2,6 naphthalate film can be preferably used because it does not ooze out oligomers or the like and can maintain a high level of transparency. In the above-mentioned preferred polyester film, it is desirable that each main constituent component is preferably at least 80 mol%, more preferably at least 90 mol%, preferably less than 20 mol%, more preferably less than 10 mol%. Other dicarboxylic acid components and diol components may be copolymerized.

In the present invention, the thermoplastic film used as the base film preferably has a surface roughness of 0.01.
To 0.3 μm, more preferably 0.03 to 0.2 μm
m, more preferably 0.05 to 0.1 μm, in that blocking can be prevented and transparency can be maintained.

The surface roughness of the base thermoplastic film is organic,
A particle-containing resin obtained by a method such as polymerization of inorganic particles or kneading of a polymer and particles can be obtained by a usual film forming method. In order to further improve transparency, it can be obtained by a method such as laminating a particle-containing resin by a coextrusion method on the surface of a thermoplastic resin film containing substantially no particles or internally formed particles, and is particularly limited. Not something.

The base film may be a single-layer film or a composite film. As the composite film, a film in which a polyethylene-2,6-naphthalate film is composited on one or both sides of a polyethylene terephthalate film by coextrusion or lamination is preferable. Of course, it is more preferable that the base film contains an ultraviolet absorber.

In the present invention, an ultraviolet absorbing layer is provided on the thermoplastic film.
A material in which an ultraviolet absorber is dispersed in a binder and a material in which an ultraviolet absorbing monomer is copolymerized can be arbitrarily selected. As the ultraviolet absorber, for example, benzophenone type, benzotriazole type, salicylic acid type, and cyanoacrylate type are preferably used. Of these, benzotriazoles are preferred in terms of transparency and absorption wavelength. Specifically, 2,4-dihydroxybenzophenone, 2-hydroxy-4, -methoxybenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, 2- (2, -hydroxy-5, tert-butylphenyl) benzotriazole , 2- (2, -hydroxy-5, -methylphenyl) benzotriazole, 2- (2, -hydroxy-
3,5, ditertiary-butylphenyl) benzotriazole and the like are used. Also, if necessary, a light stabilizer,
It is also preferable to use an antioxidant, a heat resistant agent and the like in combination.

As a composition obtained by copolymerizing an ultraviolet absorbing monomer, an ultraviolet absorbing monomer containing an unsaturated bond, for example, a benzotriazole type ultraviolet absorbing compound having an unsaturated double bond added thereto, specifically preferred monomers As 2
-(2, -Hydroxy-5, -methacryloxyethylphenyl) -2H-benzotriazole can be used, and acrylic monomers copolymerized with this monomer are alkyl acrylates and alkyl methacrylates (alkyl groups are methyl groups, Ethyl group, n-propyl group,
Isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, lauryl group, stearyl group, cyclohexyl group, etc.) and a monomer having a crosslinkable functional group, such as a carboxyl group, a methylol group,
It is possible to use a monomer having an acid anhydride group, a sulfonic acid group, an amide group, or a methylolated amide group, an amino group (including a substituted amino group), an alkylolated amino group, a hydroxyl group, an epoxy group, or the like. it can. Examples of the monomer having the above functional group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, vinylsulfonic acid, styrenesulfonic acid, acrylamide, methacrylamide, N-methylmethacrylamide, methylolated acrylamide, Methylolated methacrylamide, diethylaminoethyl vinyl ether, 2
-Aminoethyl vinyl ether, 3-aminopropyl vinyl ether, 2-aminobutyl vinyl ether, dimethylaminoethyl methacrylate and those obtained by methylating the above amino group, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β -Hydroxypropyl methacrylate β-hydroxyvinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, glycidyl acrylate, glycidyl methacrylate, and the like can be used, but are not necessarily limited thereto. Not something.

Furthermore, in addition to the above, the following monomers such as acrylonitrile, methacrylonitrile, styrene, butyl vinyl ether, mono- or dialkyl esters of maleic acid and itaconic acid, methyl vinyl ketone,
Vinyl chloride, vinylidene chloride, vinyl acetate, vinylpyridine, vinylpyrrolidone, alkoxysilane having a vinyl group, polyester having an unsaturated bond, and the like may be used as the copolymerization component.

In the ultraviolet absorbing layer, a coatability improving agent, an antifoaming agent, a thickener, an antistatic agent, inorganic particles, organic particles, organic lubricant, dyes and pigments as long as the effects of the present invention are not impaired. And stabilizers.

It is preferable to use an organic solvent as appropriate for improving workability during coating and controlling the film thickness.

The ultraviolet absorbing layer of the present invention is laminated on a substrate film as an organic solvent or an aqueous dispersion, and the laminated thickness is preferably in the range of 0.3 to 10 μm, more preferably 0.6 to 7 μm. , More preferably 1.5 to 6
μm is desirable. If the coating thickness is thinner than necessary, the effect of weather resistance is reduced. If the coating thickness exceeds 10 μm, curling or cracking due to bending or the like may occur depending on the thickness of the base film. It is desirable.

In the present invention, in order to improve the transparency of the laminated film, it is preferable that fine particles and the like are not added to the ultraviolet absorbing layer, but fine inorganic and organic particles which do not lower the transparency are added. Is also good. The fine particles to be added as required are not particularly limited, and can be selected from inorganic particles, organic particles, and the like. As the inorganic particles, calcium carbonate, silica, alumina and the like can be used, and as the organic particles, particles such as acryl, polyester and cross-linked acryl can be used.

The above ultraviolet absorbing layer can be provided on one side or both sides, but is preferably provided on both sides from the viewpoint of weather resistance. The present invention is characterized in that a layer mainly composed of a polyalkylene naphthalate copolymer containing sulfonic acid and / or a salt thereof is laminated on one surface of a substrate film. When the ultraviolet absorbing layer is provided on one side, the laminated film is provided on the surface where the ultraviolet absorbing layer is not laminated, and when the ultraviolet absorbing layer is provided on both surfaces, it is provided on one surface via the ultraviolet absorbing layer. Can be

It is more preferable that the layer mainly composed of the polyalkylene naphthalate copolymer contains an ultraviolet absorber, and it is desirable to add the ultraviolet absorber in the range of 0.5 to 30% by weight. The term “main component” as used herein refers to a component in the constituent laminated film that is preferably at least 50% by weight, more preferably at least 70% by weight, and even more preferably at least 80% by weight.

The polyalkylene naphthalate copolymer is a polyester copolymer having an alkylene naphthalate segment in the molecule. Specifically, 2,6-naphthalenedicarboxylate, its ester, and its isomer It is a copolymer containing as an acid component. The diol component is not particularly limited, but is preferably an aliphatic or alicyclic diol having 2 to 8 carbon atoms. Specifically, ethylene glycol, diethylene glycol, propylene glycol,
1,4-butanediol, cyclohexanedimethanol and the like can be preferably used. The alkylene naphthalate segment occupying in the polyalkylene naphthalate copolymer is such that the naphthalenedicarboxylate copolymerized as the acid component is preferably 2 to 90 mol%, more preferably 5 to 80 mol%, of the total acid component. . Other dicarboxylic acids to be copolymerized can be arbitrarily selected from aromatic and aliphatic dicarboxylic acids.

Here, the sulfonic acid and / or
Alternatively, as a method for obtaining a polyalkylene naphthalate copolymer containing a salt thereof, a compound having sulfonic acid and / or a salt thereof as one component of an acid component is copolymerized as an acid component of the polyalkylene naphthalate. Is preferred. Examples of the compound having a sulfonic acid and / or a salt thereof include sulfoisophthalic acid, 5-sulfoisophthalic acid, 2-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4-sulfonaphthalene-2,6-dicarboxylic acid, and alkali metals thereof. Salts (such as lithium, sodium and potassium) and ammonium salts can be used.
Among them, 4-sulfonaphthalene-
More preferably, 2,6-dicarboxylate is used.

The copolymerization ratio of the dicarboxylic acid containing sulfonic acid and / or a salt thereof is such that the contact angle of water on the surface of the laminated film formed with the copolymer is 50 degrees or less. It is preferred to copolymerize in a ratio. Specifically, the content is preferably from 7 to 60 mol%, more preferably from 15 to 50 mol%, and even more preferably from 20 to 45 mol%, of all the acid components forming the polyalkylene naphthalate copolymer. When the copolymerization ratio is less than 7 mol%, the anti-fogging effect on the surface tends to be insufficient, and when it exceeds 60 mol%, troubles such as easy blocking of the laminated surface and thickening during polymerization are caused. Is easy to occur. It is preferable to copolymerize the copolymer with polyoxyalkylene glycol as another copolymer component from the viewpoint of making the surface more hydrophilic.

The polyalkylene glycol has a molecular weight of 400
It is preferable to copolymerize in a range of 1 to 20% by weight of the copolymer in a range of 1 to 20,000. Further, a polyalkylene glycol may be used as a mixture with the above copolymer. The production of such a copolymer can be obtained by a polyester polymerization method. For example, it can be obtained by subjecting 2,6-naphthalenedicarboxylic acid dimethyl ester and sodium 5-sulfoisophthalate dimethyl ester as an acid component and ethylene glycol and diethylene glycol as a diol component to a transesterification reaction followed by polycondensation. At this time, as the reaction catalyst, for example, an alkali metal,
Alkaline earth metals, manganese, cobalt, zinc, antimony, germanium, compounds such as titanium are used,
Further, if necessary, a phosphorus compound may be added to prevent coloring.

The copolymerized polyalkylene naphthalate can be dissolved or dispersed in water or an organic solvent and laminated on a substrate film, or laminated by any method such as composite extrusion and extrusion lamination.
In the case of the application method, there are a method of applying and drying on a base film, a method of in-line coating, and the like.
Either method may be used. The in-line coating method is a method of stretching a melt-extruded base film in the longitudinal direction, applying the copolymer on one surface of the film, drying, stretching in the transverse direction, and further performing a heat treatment to obtain a laminate. It is.

In the layer containing the copolymerized polyalkylene naphthalate as a main component, various additives such as pigments, dyes, organic and inorganic fine particles, as long as the effects of the present invention are not impaired,
An antistatic agent, a heat resistant agent, and the like may be added.

Although the thickness of the laminated film of the layer containing the copolymerized polyalkylene naphthalate as a main component is not particularly limited, it is preferably 0.05 to 5 μm, more preferably 0.1 to 5 μm.
The layers are laminated in a range of 2.5 μm.

Next, a preferred embodiment of the present invention will be described, but the present invention is not limited thereto.

An acrylic resin containing an ultraviolet absorber is applied to both surfaces of the biaxially oriented polyethylene terephthalate film by a gravure coating method so that the thickness after drying becomes 5 μm, and then dried. One side of the laminated film is subjected to a corona discharge treatment, and the treated surface is dried with an aqueous solution of polyethylene naphthalate containing a metal sulfonate group having a thickness of 1 μm.
And dried to obtain the laminated film of the present invention. The laminated film obtained by the present invention can be used for applications requiring transparency, weather resistance, anti-fogging property, and dripping property, for example, agricultural greenhouses, indoor and outdoor coating materials for building materials, indoor and outdoor overlays (display materials, electric materials). It can be suitably used for decorative signs, etc.), white boards, window coverings (buildings, vehicles, etc.), touch panels, electric appliance coating materials, and the like.

[0028]

[Method of measuring characteristics and evaluating effect]

(1) Haze value The laminated film was measured using a haze meter SEP-H-2 manufactured by Nippon Seimitsu Kogaku Co., Ltd. according to JIS-K-6714.

(2) Weather resistance-1 UV deterioration promotion tester "I-Super" SUV-W13
An irradiation deterioration test was performed using Type 1 (manufactured by Iwasaki Electric Co., Ltd.). The evaluation was performed for each 8 hours of irradiation / condensation / pause,
It was evaluated as one cycle, and the degree of coloring (visual) of the film and the change in haze after eight cycles of evaluation were measured. The degree of coloring is ◎ (no abnormality in 10 cycles or more), ○ (slightly yellowish in 8 cycles or more), Δ (yellowish in 5 cycles or more), × (yellowish in less than 5 cycles) ), And ○ or more was judged as good.

(3) Weather resistance-2 The elongation half-life of the substrate film was measured using the device of the above (2). Irradiation is performed by irradiating one cycle on one side and then irradiating the opposite side for one cycle.
The irradiation cycle up to 0% was measured. The elongation was measured using a "Tensilon" UTM-III type (manufactured by Toyo Baldwin Co., Ltd.) at a speed of 200 mm / min.

(4) Contact angle with water Using a CA-D contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.)
The contact angle of the water droplet when the water droplet was dropped on the measurement surface was measured.

(5) Antifogging property 200 cc of hot water at 80 ° C. was charged into a 500 cc beaker, and the film was covered thereon, and the degree of fogging of the film was visually observed.

◎: No fogging for 3 minutes or more ： １: No fogging for 1 minute or more Δ: Water droplets adhered in less than 1 minute and fogging occurred X: Fogging occurred instantaneously.

(6) Dropping property Water is charged into a water tank kept at 25 ° C., and a film is set thereon at an angle of 30 ° from the water surface and sealed. The film surface is left in a constant temperature room set at 5 ° C. so as to be exposed to an atmosphere of 5 ° C. The time (days) during which the water droplets attached to the film surface flowed along the slope and the transparency of the film was maintained was observed.

◎: 3 months or more ○: 1 month or more and less than 3 months Δ: 0.5 months or more and less than 1 month ×: less than 0.5 months

[0036]

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

Example 1 A corona discharge treatment was performed in air on both surfaces of a transparent biaxially oriented polyethylene terephthalate film having a thickness of 150 μm (“Lumirror” T60 manufactured by Toray Industries, Inc.). ) Was applied with a gravure coater so as to have a thickness of 5 μm per side. After application, the coating was dried at 120 ° C. for 3 minutes. One surface of this laminated film was subjected to corona discharge treatment in air, and the following coating agent (B) was applied to the treated surface by a gravure coating method so that the thickness after drying was 1 μm. After coating, the coating was dried at 120 ° C. for 3 minutes to obtain a laminated film. Table 1 shows the results.

Coating agent (A) Acrylic copolymer of methyl methacrylate / ethyl acrylate / acrylic acid (60/35/15% by weight) 80 parts by weight Benzotriazole-based ultraviolet absorber (“tinuvin” -326 (Ciba Geigy Co., Ltd.) 20 parts by weight of toluene / methyl ethyl ketone (mixing weight ratio 7
/ 3) to give a 15% by weight solution.

Coating (B) 2,6-naphthalenedicarboxylic acid 80 mol% (in all acid components) Sodium 5-sulfoisophthalate 20 mol% (in all acid components) Ethylene glycol 95 mol% (in all diol components) Diethylene glycol 5 mol% (of all diol components) 12.5 wt% of polyethylene glycol (molecular weight 1000) was prepared as a copolymer by a polyester polycondensation method.
This polymer was dissolved in a 90 ° C. water / butyl cellosolve (mixing weight ratio: 9/1) mixed solvent with stirring under reflux to prepare a solution having a solid concentration of 7% by weight.

Comparative Example 1 A laminated film was prepared in the same manner as in Example 1 except that the coating agent (B) was not provided. Table 1 shows the results.

Example 2 A laminated film was prepared in the same manner as in Example 1 except that the coating material (A) of Example 1 was provided on one surface and the coating material (B) was provided on the other surface. Table 1 shows the results.

Comparative Example 2 A laminated film was prepared in the same manner as in Example 2, except that only the coating agent (A) was applied to one surface and the coating agent (B) was not applied. Table 1 shows the results.

Examples 3 and 4 Example 1 except that the base film was a biaxially oriented polyethylene-2,6-naphthalate film having a thickness of 150 μm.
A laminated film was prepared in the same manner as in (Example 3) and in Example 2 (Example 4). Table 1 shows the results.

Examples 5 to 8 In Example 1, the copolymerization ratio of sodium 5-sulfoisophthalate in the coating agent (B) was 10 mol% (Example 5),
A laminated film was prepared in the same manner as in Example 1 except that the mol% (Example 6), 30 mol% (Example 7) and 50 mol% (Example 8) were used. Table 1 shows the results.

Comparative Example 3 A polymer was prepared in which sodium 5-sulfoisophthalate in the coating composition (B) of Example 1 was 0 mol%, and this polymer was laminated on polyethylene terephthalate by a coextrusion method. The laminated film was stretched 3.5 times in the longitudinal direction and the width direction by the stretching method, and heat-treated at 210 ° C. while performing a 5% relaxation treatment in the width direction. This laminated film had a laminated thickness of 1 μm and a total thickness of 150 μm. A coating film (A) of Example 1 was applied on the opposite surface of the laminating surface in the same manner as in Example 1 to prepare a laminated film. Table 1 shows the results.

Example 9 A laminated film was produced in the same manner as in Example 1 except that sodium 4-sulfonaphthalene-2,6-dicarboxylate was used instead of sodium 5-sulfoisophthalate of the coating composition (B) in Example 1. It was created. Table 1 shows the results.

Example 10 Polyethylene terephthalate pellets were sufficiently vacuum-dried at 180 ° C., supplied to a melt extruder, melt-extruded into sheets at 290 ° C., solidified by cooling with a mirror cooling drum at 25 ° C., and unstretched sheets were obtained. Created. This sheet was stretched 3.5 times in the longitudinal direction at 95 ° C., and one surface of the sheet was subjected to a corona discharge treatment in air, and the treated surface was coated with the coating material (B) of Example 1 at 0.2 μm after biaxial orientation. It was applied so that After the application, it was led to a preheating zone of 120 ° C. while continuously gripping with clips, and after evaporating water, it was stretched 3.5 times in the width direction at 105 ° C. This film is continuously stretched in the width direction for 5
% Heat treatment at 210 ° C. for 15 seconds. The obtained laminated film had a laminated thickness of 0.2 μm and a total thickness of 150 μm. The coating agent (A) of Example 1 was applied to the opposite side of the laminated film from the laminated surface to prepare a laminated film. Table 1 shows the results.

[0048]

[Table 1]

[0049]

The laminated film formed according to the present invention is excellent in weather resistance, transparency, anti-fogging property and dropping property.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B32B 27/30 B32B 27/30 A C08J 7/04 CFD C08J 7/04 CFDB // C08L 67:03

Claims (5)

[Claims] 1. The method according to claim 1, wherein at least one side of the thermoplastic film has
A laminated film comprising a layer having a polyalkylene naphthalate copolymer containing sulfonic acid and / or a salt thereof as a main component laminated on one surface of a laminated film provided with an ultraviolet absorbing layer. 2. The laminated film according to claim 1, wherein the ultraviolet absorbing layer contains a benzotriazole-based ultraviolet absorbing agent. 3. The laminated film according to claim 1, wherein the thermoplastic film is a polyester film. 4. The method according to claim 1, wherein the surface of the layer containing the polyalkylene naphthalate copolymer as a main component has a contact angle with water of 50 degrees or less. Laminated film. 5. An ultraviolet absorbing layer is provided on both surfaces of a thermoplastic film, and a polyalkylene naphthalate copolymer containing a sulfonic acid and / or a salt thereof is mainly provided on one surface of the thermoplastic film via the ultraviolet absorbing layer. The laminated film according to any one of claims 1 to 4, wherein a layer to be formed is laminated.