JPH08323935A - Dewing preventing laminated film or sheet and production thereof - Google Patents

Abstract

PURPOSE: To provide a dewing preventing film or sheet capable of preventing dewing under high humidity environment or on a boundary surface markedly different in humidity over along period of time and capable of being easily bonded or peeled without lowering water resistance. CONSTITUTION: A dewing prevent film or sheet 6 is obtained by laminating a water absorbable film or sheet 2 containing a polyvinyl alcohol resin (A) with a saponification value of 60mol% or more and a polymerization degree of 500-2,500 and an alkali hydrolysate (B) of an isobutylene/maleic anhydride copolymer wherein 25-50% of a carboxyl group is an alkali metal salt in a wt. ratio of (A)/B=99/1-70/30 and a water insoluble thermoplastic film or sheet 1 with haze of below 20% through an adhesive layer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applicable to a mirror surface of a bathroom, a window glass of an automobile, a train, a house, a glass plate in a greenhouse, a lens of eyeglasses, goggles or a curved mirror, etc., in a high humidity environment or under remarkable temperature. Condensation-preventing laminated film or sheet (hereinafter simply referred to as a film) that is useful for sticking to glass surfaces at different boundaries to prevent condensation for a long time
And a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, various proposals have been made and adopted in order to prevent dew condensation on transparent glass or plastic products. For example, the following methods are available. 1) Method of bringing the contact angle of water on the surface of the molded product as close as possible to 0 °: A surface modifier such as a surfactant is kneaded into the resin, and after molding, the surface of the molded product is considered to be compatible with the resin. To prevent dew condensation by bleeding it out or to prevent dew condensation by applying a surface modifier such as a surfactant to the surface of the molded product. 2) A method to make the contact angle of the surface of the molded product with water as close as possible to 180 °: A method in which a hydrophobic substance such as silicone oil, liquid paraffin, or vaseline is applied to the surface of the molded product so that water droplets flow down, and a fluorine-based method. Method for obtaining a molded article from a hydrophobic resin such as resin, JP-A-48-47939, JP-A-59-179684, JP-A-3
A method of modifying the water repellency of a resin with an organic silicon compound as described in JP-A-181586 to 181589, etc. 3) Method of providing a water absorbing layer on the surface of the molded product: a method of applying a resin having a high affinity for water to the surface of the molded product and absorbing water droplets adhering to the surface. 4) A method for preventing the dew condensation by keeping the surface of the molded product at a temperature always higher than the dew point: a method for attaching a heating element to the inner surface of the glass to heat the glass to prevent the dew condensation.

[0003]

However, in the method of 1) above, when the surfactant is repeatedly contacted with water,
The surfactant dissolves in water and flows out, so that the effect of preventing dew condensation is not exhibited. That is, the effect of preventing dew condensation by this method is only the initial effect and the durability is poor. The method 2) has no effect on fine water droplets. The method of 3) includes 1) and 2).
It is more durable than the method of preventing dew condensation,
The part in contact with the water droplets expands, causing wrinkles or peeling. Further, when the water-absorbent film is adhered to the surface of glass or the like with an adhesive, the appearance of the water-absorbent film is partially deteriorated when peeled off. The method 4) requires large initial investment and high power cost, and can be used only for special purposes. Therefore, the object of the present invention is to prevent dew condensation for a long period of time in a high humidity environment or at a boundary surface where the humidity is remarkably different, and can be easily attached or peeled without lowering the water resistance. PROBLEM TO BE SOLVED: To provide a laminated film and a manufacturing method thereof.

[0004]

Means for Solving the Problems The inventor of the present invention has disclosed in JP-A-59-6.
As a result of repeated research focusing on the water absorption capacity of the water-absorbent film described in each of the 4650 and 60-210444 publications, the adhesive portion between the water-absorbent film and the thermoplastic resin film absorbs moisture, absorbs water or discharges moisture, Shear strength that is stronger than the stretching force of the water-absorbent film accompanying drainage is given, one side of the thermoplastic resin film is laminated with this water-absorbent film, and the adhesive layer is provided on the other side of the thermoplastic resin film. The present invention has been accomplished by finding that, if provided, the obtained laminated film can be easily attached to the surface of glass or the like and a dew condensation preventing effect can be imparted, and the present invention has been achieved.

That is, the dew condensation preventing laminated film according to the present invention has a saponification degree of 60 mol% or more and a polymerization degree of 500 to 2,500.
Of polyvinyl alcohol resin (A) and an alkali hydrolyzate (B) of an isobutylene-maleic anhydride copolymer in which 25 to 50% of carboxyl groups are alkali metal salts, in a weight ratio (A) / (B ) = 99/1 to 70/30, and a water-insoluble thermoplastic resin film having a haze of less than 20% are laminated via an adhesive layer. Yes, and its manufacturing method is
Polyvinyl alcohol resin (A) having a saponification degree of 60 mol% or more and a polymerization degree of 500 to 2,500, and a carboxyl group of 25 to 50
% Of an alkali metal salt of an isobutylene-maleic anhydride copolymer hydrolyzate (B) are mixed at a weight ratio (A) / (B) = 99/1 to 70/30. After the film is formed, the water-absorbent film obtained by heat treatment at a surface temperature of 130 to 200 ° C for 1 to 60 seconds has a water-insoluble haze of 20.
%, The thermoplastic resin film is pressure-bonded via an adhesive layer.

An embodiment of the dew condensation preventing laminated film according to the present invention will be described below with reference to FIG. 1 which is a longitudinal sectional view. The anti-condensation laminated film according to the present invention comprises a thermoplastic resin film 1 having a water-insoluble haze of less than 20%, the water-absorbent film 2 and the adhesive layer 3,
In practice, as shown in the drawing, the pressure-sensitive adhesive layer 4 and the release paper 5 are further stacked and used on the opposite surface of the thermoplastic resin film 1.

If the haze of the thermoplastic resin film 1 is 20% or more, the transparency is poor and, particularly when applied to glass or the like, it becomes difficult to see the image from the inner surface to the outer surface of the glass. It is unsuitable as a constituent material of a laminated film. Examples of the thermoplastic resin film 1 suitable for this purpose include transparent synthetic resins such as polyester, polyethylene, polyvinyl chloride, and polymethylmethacrylate. These thermoplastic resin films have a thickness of 10
If the thickness is less than μm, wrinkles are likely to occur due to expansion and contraction due to moisture absorption / exhaust of the water absorbing layer, and if it exceeds 800 μm, the construction tends to be difficult and the cost increases, so a thickness in the range of 10 to 800 μm is usually used. .

The water-absorbent film 2 is an alkaline hydrolyzate of a polyvinyl alcohol resin (A) having a saponification degree of 60 mol% or more and a polymerization degree of 500 to 2,500, preferably 1,000 to 2,000, and an isobutylene-maleic anhydride copolymer. (B) and the weight ratio (A) / (B) = 99/1 to 70/30. The polyvinyl alcohol resin (A)
When the saponification degree is less than 60 mol%, the solubility of the polyvinyl alcohol resin in water is remarkably poor, which is not preferable. In general, the upper limit of saponification degree is 99.99%. When the degree of polymerization is less than 500, the strength of the thin film is reduced and cracks occur on the film surface, and when it exceeds 2,500, the viscosity is remarkably increased and it becomes difficult to form a water absorbing layer. Such a polyvinyl alcohol resin can be obtained by hydrolyzing a polymer obtained by polymerizing a vinyl ester such as vinyl acetate or vinyl formate or a vinyl ether such as t-butyl ether or trimethylsilyl vinyl ether with an acid or an alkali.
Generally, a film produced from a polyvinyl alcohol resin obtained by hydrolyzing a polymer obtained by polymerizing vinyl acetate is suitable in terms of cost.

On the other hand, the alkali hydrolyzate (B) of the isobutylene-maleic anhydride copolymer contains isobutylene-
A maleic anhydride copolymer hydrolyzed with an aqueous solution of an alkali metal compound or an alkaline earth metal salt compound is used. Here, examples of the alkali metal compound or the alkaline earth metal salt compound include sodium hydroxide, potassium hydroxide, lithium hydroxide and magnesium hydroxide. The proportion of the carboxyl groups in the hydrolyzate forming an alkali metal salt (hereinafter referred to as the degree of neutralization) is 25 to 50%, preferably 30 to 50%. Generally, isobutylene-maleic anhydride is hydrolyzed with an alkali metal compound or an alkaline earth metal compound to give a neutralization degree of 25.
It is very difficult to make an isobutylene-maleic anhydride copolymer of less than%. When the degree of neutralization exceeds 50%, the compatibility with the polyvinyl alcohol resin becomes poor, and it becomes difficult to obtain a film, and the polyvinyl alcohol-based resin and the alkali hydrolyzate of isobutylene-maleic anhydride copolymer Since the crosslinking reaction is remarkably suppressed, when water drops adhere to the film surface, the film expands and further the film dissolves and flows out. The weight average molecular weight of this isobutylene-maleic anhydride copolymer is 5.5 ×
10 ^{4 to} 17 × 10 ⁴ are preferable.

The mixing ratio of the polyvinyl alcohol resin (A) and the alkali hydrolyzate of isobutylene-maleic anhydride copolymer (B) is 99 / (B) / (B).
It is preferably in the range of 1 to 70/30, and particularly preferably in the range of 90/10 to 75/25. When the weight composition ratio of the polyvinyl alcohol resin is more than 99/1, the function as a water absorbing film cannot be sufficiently exerted, and when the mixing ratio of the polyvinyl alcohol resin is less than 70/30, the water absorbing film becomes hard and brittle. I will end up. The thickness of the water absorbent film is preferably 5 to 100 μm, particularly preferably 20 to 50 μm. 5
The formation of films below μm and above 100 μm is extremely difficult. The method for forming the water-absorbent film may be any method as long as it can form an independent thin film, but the casting method is generally preferred.

In the production of a water-absorbent film, a polyvinyl alcohol resin and an alkali hydrolyzate of isobutylene-maleic anhydride are mixed in the above proportions to form a film, and the film obtained is subjected to a surface temperature of 130 to 200. 1 at ℃
The method of heat treatment is employed for -60 seconds, preferably 150-180 ° C for 10-30 seconds. At this time, the surface temperature of the film
If the heat treatment is performed at a temperature of less than 130 ° C. for less than 1 second, the crosslinking reaction between the polyvinyl alcohol-based resin and the alkali hydrolyzate of the isobutylene-maleic anhydride copolymer becomes insufficient, and the film after water absorption and drying becomes cloudy. If heat treatment is performed at a surface temperature of the film exceeding 200 ° C, the polyvinyl alcohol-based resin is decomposed and discolored. For the heat treatment of the water-absorbent film, any method of hot air, infrared rays, heating rolls or a combination of these may be used.

In addition to the above-mentioned components, the water-absorbent film contains cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, starch or derivatives thereof, xanthan gum and carrageenan, in addition to the above components, if necessary. Polysaccharides, polyacrylic acid or its derivatives, water-soluble resins such as water-soluble polymers such as polyacrylamide, poly-N-vinylpyrrolidone and polyethylene oxide, plasticizers such as glycerin, polyethylene glycol and ethanolamine, nonionic or anionic Surfactants, acetylene alcohol, various cross-linking agents for polyvinyl alcohol resins, isobutylene-
Various crosslinking agents, antifoaming agents, preservatives and the like of alkaline hydrolysates of maleic anhydride copolymer can be added.

The adhesive forming the adhesive layer 3 interposed between the thermoplastic resin film 1 and the water absorbent film 2 has the ability to prevent the expansion / contraction of the moisture absorption / exhaust layer due to moisture absorption / exhaustion. Adhesive strength with greater shear strength is required, so urethane-based two-liquid reaction type (reaction type of polyester having hydroxyl group, amino group or carboxyl group at both ends and polyisocyanate) adhesive, epoxy resin type adhesive Agents are preferred. These adhesives are water resistant,
Excellent resistance to high temperature and humidity. Further, if necessary, an additive such as an ultraviolet absorber may be added. When the water-absorbent film and the thermoplastic resin film are adhered to each other with an adhesive capable of obtaining only a shear strength equal to or lower than the stretching force of the thermoplastic resin film, wrinkles are likely to occur.

The dew condensation preventing laminated film according to the present invention is
The water-absorbent film thus obtained and the thermoplastic resin film are laminated via an adhesive layer. A dry lamination method is preferable as the stacking method. The dry lamination method in the present invention is preferably toluene, after dissolving the adhesive in an organic solvent such as ethyl acetate or a mixed solvent thereof, usually on one surface of the thermoplastic resin film, a gravure coater, An adhesive is applied by a wire bar or other known means, and the solvent is volatilized to form an adhesive-applied surface. Then, a water-absorbent film is placed on the adhesive surface and heat-pressed.
The conditions for thermocompression bonding at this time are that the temperature is 15 ° C. or higher, the melting point of the thermoplastic resin or lower, and the pressure is 2 kg / cm 2 or more in linear pressure. In addition, as shown in FIG. 1, the dew condensation preventing laminated film is usually used by providing a pressure-sensitive adhesive layer on the opposite surface of the thermoplastic resin film and attaching a release paper thereto. Examples of the pressure-sensitive adhesive used for forming this pressure-sensitive adhesive layer include polyacrylic acid ester-based pressure-sensitive adhesives and silicone-based pressure-sensitive adhesives. These are preferably used in the form of being dissolved in an organic solvent such as toluene or ethyl acetate, and usually, on the release agent coated surface of release paper, wire bar, gravure coater, die coater, comma coater, knife coater, etc., or other After the pressure-sensitive adhesive is applied by a known means to vaporize the solvent to form an adhesive-coated surface, the thermoplastic resin film side of the dew condensation-preventing laminated film is superposed on this adhesive surface and pressure-bonded for lamination. By providing the pressure-sensitive adhesive layer in this manner, it can be easily attached to or peeled from glass or the like.

[0015]

The dew condensation-preventing laminated film according to the present invention has a function of preventing dew condensation on the surface by the water-absorbing film made of a mixture of polyvinyl alcohol resin on the surface and alkali hydrolyzate of isobutylene-maleic anhydride copolymer. is there. Further, the crosslinking reaction between the polyvinyl alcohol resin and the alkali hydrolyzate of the isobutylene-maleic anhydride copolymer can prevent expansion during water absorption and dissolution and outflow of the water absorbent film. Further, the water-absorbent film, in combination with the adhesive force such as an adhesive having a shear strength greater than the stretching force due to this moisture absorption and drainage, moisture absorption, water absorption or moisture removal, for suppressing the dimensional change when performing drainage. Acts as a support.

[0016]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these descriptions without departing from the gist of the present invention. (A: Production of Water-Absorbing Film) Examples 1 to 5 A polyvinyl alcohol-based resin having a saponification degree and a polymerization degree shown in Table 1 (referred to as PVA resin in the table) was placed in ion-exchanged water and heated to 80 ° C or higher. It was heated and melted. After the dissolution, the concentration of the polyvinyl alcohol-based resin aqueous solution was adjusted to 10% by weight. On the other hand, the degree of neutralization is 0.45, 0.40 and 0.30, and the molecular weight is
An aqueous solution of 16 × 10 ^{4 to} 17 × 10 ⁴ isobutylene-maleic acid sodium hydroxide hydrolyzate (manufactured by Kuraray Co., Ltd., referred to as a copolymer in the table) was adjusted to a concentration of 10% by weight. As shown in Table 1, various compositional weight ratios of the polyvinyl alcohol-based resin and the sodium hydroxide hydrolyzate of the isobutylene-maleic anhydride copolymer were prepared to prepare solutions having different thicknesses.
Apply it on a 125 μm polyethylene terephthalate film with a wire bar to a dry thickness of 25 μm.
After drying at 110 ° C. for 10 hours, it was peeled from the polyethylene terephthalate film, and the obtained film was heat-treated in an oven at a film surface temperature of 160 ° C. for 10 seconds. With respect to the obtained water-absorbent film, the water absorption amount and the elution amount of organic substances after being immersed in warm water at 60 ° C. for 30 minutes were determined by the following methods, and the respective results are also shown in Table 1.

(Amount of Water Absorption) A water-absorbent film was cut into 5 cm square pieces, immersed in ion-exchanged water at 23 ° C. for 1 hour, taken out, and the water adhering to both surfaces was sufficiently removed with a filter paper, and the weight (W ₁ ) Was measured. Next, this water-absorbent film
After drying at 110 ° C. for 3 hours, the weight (W ₂ ) in an absolutely dry state was measured. From these measured values, the water absorption amount was calculated by the following formula. Water absorption _{= (W 1 -W 2) /} 25 × 10 -3

(Organic substance elution test) 10.0% water absorbent film
It was cut into a size of cm × 6.25 cm and immersed in distilled water at a ratio of 2 ml per cm ^{2 at} 60 ± 2 ° C. for 30 ± 0.5 minutes and taken out. The remaining solution was used as a test solution. This test solution is 100
5 ml of dilute sulfuric acid prepared by diluting 1 ml of 96% sulfuric acid with 2 of ion-exchanged water was added, 10 ml of N / 100 potassium permanganate solution was added, and the mixture was heated and boiled for 5 minutes. Next, the heating was stopped, 10 ml of N / 100 sodium hydrobromide solution was immediately added to decolorize, and then the N / 100 potassium permanganate solution was titrated until the deep red color remained and remained. Separately, a blank test was carried out by the same method, and the consumption amount of potassium permanganate was determined by the following formula, which was taken as the organic substance elution amount.・ Potassium permanganate consumption = [(ab) x 1,000
× f / 100] × 0.316 where a: potassium permanganate titer ml of this test ml b: potassium permanganate titer ml of blank test f: N / 100 normality coefficient of potassium permanganate solution (f
= 0.9901)

[0019]

[Table 1] The water-absorbent films obtained in Examples 1 to 3 all had an organic substance elution amount of 10 ppm or less, and had excellent water resistance.

Comparative Examples 1 to 8 Polyvinyl alcohol resins having a saponification degree and a polymerization degree shown in Table 2 and a molecular weight of 16 × 10 6 having a neutralization degree shown in Table 2.
The composition weight ratio of ^{4 to} 17 × 10 ⁴ isobutylene-maleic anhydride to sodium hydroxide hydrolyzate is shown in Table 2, respectively.
Example 1 except that various solutions were used as shown in FIG.
When the production and evaluation of the water-absorbent film were attempted in the same manner as in Examples 1 to 5, the following results were obtained.

[0021]

[Table 2]

(Results) In Comparative Examples 1 and 2, the polyvinyl alcohol resin could not be completely dissolved, even though the mixture was stirred in hot water at 80 ° C. or higher for 5 hours. In Comparative Example 3,
No water absorbent film was obtained. In Comparative Example 4, the polyvinyl alcohol resin-copolymer mixed solution had a high viscosity and a film having a smooth surface could not be obtained. Therefore, the concentration of the mixed solution was further diluted to 1% by weight, but a film having a smooth surface could not be obtained. In Comparative Example 5, no water absorbent film was obtained. In Comparative Example 6, the water absorption amount of the water absorbent film was 37 g / m ² and the elution amount of organic substances was 480 ppm. In Comparative Examples 7 and 8, the water-absorbent film was cloudy. The water absorption of the film could not be measured because the film gelled during immersion in ion-exchanged water.

Comparative Example 9 A polyvinyl alcohol resin having a saponification degree of 99.9 mol% and a polymerization degree of 1,700 was placed in ion-exchanged water and heated to 80 ° C. or higher to dissolve it. After the dissolution, the concentration of the polyvinyl alcohol-based resin aqueous solution was adjusted to 10% by weight. The degree of neutralization 0.4
5, an aqueous solution of sodium hydroxide hydrolyzate of isobutylene-maleic anhydride having a molecular weight of 16 × 10 ^{4 to} 17 × 10 ⁴ was added at a concentration of 10
Adjusted to wt%. A composition weight ratio (polyvinyl alcohol resin) / (isobutylene-maleic anhydride copolymer sodium hydroxide hydrolyzate) is used, in which the polyvinyl alcohol resin aqueous solution and the sodium hydroxide hydrolyzate aqueous solution of isobutylene-maleic anhydride copolymer are combined. ) = 90/10, and then coated on a polyethylene terephthalate film having a thickness of 125 μm with a wire bar so that the dry thickness becomes 25 μm, and dried at 110 ° C. for 10 minutes. When the water absorption amount and the organic substance elution test were performed on the obtained water absorbent film, the water absorption amount was excellent at 80 g / m ² , but the water absorbent film was dissolved during the organic substance elution test. At 110 ° C
For the water-absorbent film that had been dried for 10 minutes and then heat-treated for 90 seconds at a film surface temperature of 200 ° C,
It was markedly discolored.

(B: Production of Dew Condensation Preventing Laminated Film) Examples 6 to 9, Comparative Example 10 75 μm thick polyethylene terephthalate film HSW-
75 (Teijin Co., haze: 1.3%), urethane-based two-liquid reaction type (polyester having hydroxyl groups at both ends, isocyanate reaction type) adhesive (main agent: Takeda Pharmaceutical Company Limited, Takelac A610, curing agent: the same company) Manufactured by Takenate A10, blending ratio by weight: Takelac A610 / Takelac A10 = 9/1),
After coating and drying with a wire bar to a thickness of the adhesive solid of 5 μm, each of the water-absorbent films obtained in Examples 1 to 3 and 5 and Comparative Example 6 was applied to the nip portion.
The laminate film was nipped by a roll of 60 ° C. and aged at 40 ° C. for 3 days to obtain each laminated film of Examples 6 to 9 and Comparative Example 10. Next, on the polyethylene terephthalate side of each laminated film, a polyacrylic acid ester-based adhesive (main ingredient SK Dyne 1811L: manufactured by Soken Chemical Co., Ltd., curing agent D-90: manufactured by the same company) has a solid thickness of 20 μm. After coating with a wire bar and drying as described above, release paper (thickness 20 μm) was stuck using a nip roll, and aging was performed at 35 ° C. for 3 days. The laminated film thus obtained, 10
It was cut into cm squares, attached to an acrylic resin plate having a thickness of 5 mm, and a dew condensation prevention test was conducted by the following method. The results are shown in Table 3.

Example 10 The same as Example 6 except that a vinyl chloride sheet having a thickness of 250 μm and a haze of 18% was used in place of the polyethylene terephthalate film, and this was laminated with the water-absorbent film obtained in Example 1. To produce a laminated film,
A similar test was conducted.

(Dew Condensation Prevention Test) The temperature of the constant temperature and humidity chamber side was measured using a fitting dew prevention performance tester manufactured by Fuji Tester:
The initial dew condensation prevention effect was defined as the dew condensation prevention effect when left for 30 minutes (A operation) under the conditions of 20 ° C., humidity: 70% RH, and temperature on the temperature-controlled room side: 3 ° C. Next, it was left for 23 hours and 30 minutes (B operation) under the conditions of the temperature of the constant temperature and humidity chamber side: 25 ° C., the humidity: 50% RH, and the temperature of the constant temperature chamber side: 25 ° C. This A operation, B
After the operation was repeated 30 times, the anti-condensation effect of the operation A was defined as the durability anti-condensation effect. The anti-condensation effect of each was visually observed according to the following evaluation criteria. It should be noted that ⊚ and ◯ are determined to have a dew condensation prevention effect. At the same time, the presence or absence of wrinkles was also observed. ⊚: No water droplets are attached to the film surface. ◯: Water droplets with a diameter> 10 mm adhered to a part of the film. Δ: Water drops having a diameter of 2 to 10 mm adhered to the entire surface of the film. X: A large number of water drops having a diameter of <2 mm adhered to the entire surface of the film.

[0027]

[Table 3] In Examples 6 to 10, an excellent dew condensation preventing effect was recognized.
No wrinkles were observed. In Comparative Example 10, a large number of water droplets having a diameter of less than 2 mm adhered to the entire surface of the film, but no wrinkles were observed.

Comparative Example 11 Using the water-absorbent film obtained in Example 1 and the polyethylene terephthalate film of the previous example, a polyacrylic acid ester-based adhesive was used instead of the urethane two-component reactive adhesive to obtain a solid content. The pieces were laminated so that the thickness was 20 μm. Further, a similar pressure-sensitive adhesive layer was provided on the polyethylene terephthalate surface side, and release paper was attached. Other than this, a laminated film was prepared in the same manner as in the previous example, and a dew condensation prevention test was conducted in the same manner.As a result, many wrinkles were observed in the water-absorbing film during the durability test, and a part peeled from the polyethylene terephthalate film was also observed. Was given.

Comparative Examples 12 to 13 The water absorbent film obtained in Example 1 was used,
As a thermoplastic resin film, the haze with a thickness of 200 μm is 40.
% Polypropylene film and 200 μm thick haze
A laminated film was prepared in the same manner as in Example 6 except that a 25% vinyl chloride film was used, and a polypropylene acrylate adhesive layer and release paper were provided on the polypropylene film side and the polyvinyl chloride side, respectively. It was made. This laminated film was cut into a 10 cm square piece and attached to a window glass. When the outside was viewed from the inside, the outside image could not be confirmed.

[0030]

The anti-condensation laminated film according to the present invention has the function of preventing the dew condensation on the surface by the water-absorbing film on the surface; generation of wrinkles and water absorption due to swelling when water drops adhere to the surface of the water-absorbing film. It is possible to prevent dissolution and outflow of the water-absorbent film; wrinkles caused by swelling and expansion and contraction of the water-absorbent film due to moisture absorption, water absorption and dehumidification, and drainage by adhesively applying the water-absorbent film to the surface layer of glass, etc. Can be completely prevented; the pressure-sensitive adhesive layer can be easily attached to or peeled from the surface of glass or the like;

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of one embodiment of a dew condensation-preventing laminated film of the present invention.

[Explanation of symbols]

1 ... Thermoplastic resin film, 2 ... Water absorbing film, 3 ... Adhesive layer,
4 ... Adhesive layer, 5 ... Release paper,
6 ... Dew condensation preventing laminated film.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B29L 9:00

Claims (2)

[Claims] 1. A saponification degree of 60 mol% or more and a polymerization degree of 500 to 2,5.
Polyvinyl alcohol resin (A) of 00 and isobutylene in which 25 to 50% of the carboxyl groups are alkali metal salts
A water-absorbent film or sheet containing an alkaline hydrolyzate of a maleic anhydride copolymer (B) in a weight ratio (A) / (B) = 99/1 to 70/30 and a water-insoluble haze of 20.
% Of a thermoplastic resin film or sheet is laminated via an adhesive layer, and a dew condensation preventing laminated film or sheet is provided. 2. A saponification degree of 60 mol% or more and a polymerization degree of 500 to 2,5.
Polyvinyl alcohol resin (A) of 00 and isobutylene in which 25 to 50% of the carboxyl groups are alkali metal salts
The alkali hydrolyzate (B) of the maleic anhydride copolymer was mixed at a weight ratio (A) / (B) = 99/1 to 70/30 to form a film, and the surface temperature was 130 to 200. Characterized in that the water-absorbent film or sheet obtained by applying a heat treatment at 1 ° C. for 1 to 60 seconds is pressure-bonded to a thermoplastic resin film or sheet having a water-insoluble haze of less than 20% via an adhesive layer. A method for producing a dew condensation preventing laminated film or sheet.