JPH07118039A - Transparent laminated body - Google Patents

Abstract

PURPOSE:To obtain a transparent laminated body having visual field selecting function and free from the change of cracked parts with the time elapsed, the deterioration of mechanical strength caused due to the cracked parts and the degradation of transparency due to wear. CONSTITUTION:A laminated film constituted by inserting a plastic film having plural cracks, which continuously spread in the width direction of the plastic film, penetrate in the thickness direction of the plastic film and exist at an almost equal interval in the longitudinal direction on the plastics, between at least tow intermediate films is held between two transparent plate-like body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent laminate, and more specifically, it has a visual field selecting function that is transparent when viewed from the front and opaque when viewed from an angle, and is used for construction, vehicles, store clothing, etc. The present invention relates to a transparent laminate used for openings, partitions and the like.

[0002]

2. Description of the Related Art Polyvinylidene fluoride (PVDF), polyvinyl butyral (PVB), polysulfone (PS
A plastic film such as F) is regularly and continuously cracked (= craze; small cracks (cracks) that scatter light) by passing it under a constant tension through a path accompanied by locally sharp bending. RIKEN 4th edition (Iwanami Shoten)]) can be generated. This cracked plastic film has a visual field selection function that makes it transparent when viewed from the front and opaque when viewed from an angle. For example, see Polymer Preprints, Japan Vol.4.
1, No. 4 (1992).

Since the cracks generated in the above plastic film penetrate the plastic film, changes in optical performance due to the inclusion of foreign matter into the cracked portion, deterioration due to local oxidation, enlargement / reduction of the cracked portion, and the like. However, there are drawbacks such that the function deteriorates or changes due to aging of the cracks, mechanical strength decreases due to the cracked portion, and the surface is worn to decrease transparency.

Further, even if the rotation axis is rotated in a direction perpendicular to the direction in which cracks extend on the plane of the plastic film, the plastic film remains transparent, and the visual field selection function is provided only in one direction. It had the drawback of not being able to have it.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, the present invention has a visual field selection function and changes in a cracked portion with time.
A transparent laminated body which does not have a decrease in mechanical strength caused by a cracked portion and a decrease in transparency due to abrasion of the surface, and
It is an object to provide a transparent laminate having a visual field selection function in two directions.

[0006]

The invention according to claim 1 is
At least 2 plastic films having a plurality of cracks that extend continuously in the width direction of the plastic film, penetrate through the thickness direction of the plastic film, and are present at substantially equal intervals in the longitudinal direction of the plastic film.
The laminated film sandwiched between the two intermediate films is a transparent laminated body sandwiched between the two transparent plate-shaped bodies.

The cracks block the rays of light entering from a certain direction, and the cracked plastic film has a visual field selection function. The state at this time is schematically shown in FIG.

As a method of causing cracks in a plastic film, for example, a method of passing a path such as a metal edge accompanied by locally sharp bending under constant tension can be mentioned. Even if the tension is small or large, proper cracking is less likely to occur, so 0.5 to 20 N
(Newton: kgm / sec ^-2 ) is preferable.

Examples of the plastic film include polyvinylidene fluoride (PVDF) film, polyvinyl butyral (PVB) film, polysulfone (PSF) film, polymethylmethacrylic acid film, acetal resin film, acrylic resin film,
Ethylene-vinyl acetate copolymer film, ionomer resin film, polyamide film, polyallyl ether film, polyallyl sulfone film, polyester film, polyethylene film, polyethylene terephthalate film, polyimide film, polyamideimide film, polypropylene film, polyether sulfone film , Polyvinyl chloride film, polyurethane film, polystyrene film, styrene-acrylonitrile resin film, polybutylene terephthalate film, etc., preferably polyvinylidene fluoride (PVDF) film, polyvinyl butyral (PVB) film, polysulfone (PSF) film. , Polystyrene film and polymethylmethacrylic acid film.

The thickness of the above-mentioned plastic film is 0.01 to 1.0 mm because the mechanical strength decreases as the thickness decreases, and the plastic film easily breaks when cracks occur, and cracks hardly occur when the thickness increases. preferable.

The intermediate film used in the invention of claim 1 is not particularly limited, and examples thereof include plasticized polyvinyl butyral type, polyvinyl chloride type, urethane type and ethylene-type.
An intermediate film such as a vinyl acetate copolymer system may be used.

The thickness of the intermediate film is preferably 50 μm to 1 mm because the impact resistance of the transparent laminate decreases as the thickness decreases, and the transparency of the transparent laminate decreases as the thickness increases.

Examples of the transparent plate used in the invention of claim 1 include inorganic glass, organic glass and the like. The above-mentioned inorganic glass is not particularly limited, and a commonly used plate glass is used, and a processed plate glass such as heat-reflecting glass that has been vapor-deposited or sputtered with metal, conductive glass, and a pattern plate glass having a pattern is given. It may be used.

The organic glass is not particularly limited as long as it has rigidity and transparency, and examples thereof include polycarbonate, acrylic resin such as polymethylmethacrylate, polystyrene, polyvinyl chloride, polyester, and the like. Examples include plastic glass such as celluloid and cellulose derivatives.

In the method for producing the transparent laminate of the present invention, for example, a cracked plastic film is sandwiched between two intermediate films to obtain a laminated film, and the obtained laminated film is divided into two. It is sandwiched between transparent plate-like bodies, laminated, put in a vacuum bag, deaerated at a vacuum degree of 0 to 20 torr, then taken out from the vacuum bag, and the temperature is 100 to 1 in an autoclave.
A method of obtaining a transparent laminate by holding at 50 ° C. for 10 to 60 minutes can be mentioned.

According to a second aspect of the present invention, in the transparent laminate, a laminate film in which at least two plastic films are sandwiched between at least two intermediate films is sandwiched between two transparent plate-like bodies, It is a transparent laminate in which plastic films are laminated so that the cracks of the respective plastic films do not extend in the same direction.

The plastic film used in the transparent laminate of the invention of claim 2 is the same as the plastic film of claim 1, and 2
The sheets may be made of the same material or different materials.

The difference in the extending direction of the cracks generated in each of the two plastic films is such that the two plastic films are superposed so that the extending directions of the cracks are the same, and one is fixed and the other is fixed. It is represented by the rotation angle when rotated, and this rotation angle is 70 to 11
0 ° is preferable, and 80 to 100 ° is more preferable.

Examples of the intermediate film and the transparent plate used in the transparent laminate of the invention of claim 2 are the same as those used in the transparent laminate of the invention of claim 1. Further, as a method for producing the transparent laminate of the invention described in claim 2, the same method as the method for producing the transparent laminate of the invention described in claim 1 can be mentioned. The adhesive used for adhering the two plastic films is not particularly limited as long as it is an adhesive having good transparency, and an intermediate film is further sandwiched between the two plastic films. Good.

[0020]

According to the first aspect of the present invention, a plurality of plastic films extending continuously in the width direction of the plastic film, penetrating in the thickness direction of the plastic film and existing at substantially equal intervals in the longitudinal direction of the plastic film. A laminated film is formed in which a cracked plastic film is sandwiched by at least two intermediate films. The formed laminated film is sandwiched between two transparent plate-like bodies to form a transparent laminated body. The formed transparent laminate has a visual field selection function due to cracks in the sandwiched plastic film.

The plastic film is encapsulated inside the transparent laminate, and the surface hardness of the transparent laminate is high and it is mechanically and chemically stable. Therefore, the plastic film is stable against chemical changes such as functional deterioration due to foreign substances mixed in from the outside, deterioration due to oxidation, etc., is less susceptible to external force, and strength reduction due to mechanical influences and surface abrasion are less likely to occur.

In the invention described in claim 2, the two plastic films described in claim 1 are stacked so that the cracks do not extend in the same direction. A transparent laminate is formed using the laminated plastic films in the same manner as in the first aspect of the invention. In the formed transparent laminate, the directions in which the cracks of the two included plastic films extend are not the same,
When the visual field selection function is generated in two directions and, for example, they are orthogonal to each other, as illustrated in FIG. A field-of-view selection function is generated by rotation about an axis that bisects the longitudinal direction). Here, the results are shown in Table 1 in comparison with the case where there is only one cracked plastic film. In addition,
The transparent laminate of the invention described in claim 2 has a high surface hardness and is mechanically and chemically stable, like the transparent laminate of the invention described in claim 1.

[0023]

[Table 1]

[0024]

EXAMPLES Next, examples of the present invention will be described. In the following, "parts" means "parts by weight". Example 1 (1) Preparation of cracked plastic film Polyvinylidene fluoride resin (“Kainer # manufactured by Mitsubishi Petrochemical Co., Ltd.”
720 ") was formed into a film by an extrusion molding machine and had a thickness of 25μ.
A polyvinylidene fluoride film of m, width of 10 cm and length of 1 m was regularly and continuously cracked by passing a metal edge accompanied by a sharp bend of 135 ° locally at a tensile speed of 30 mm / min under a constant tension of 10 N. Was generated. The outline of the above route is shown in FIG.

The structure of the obtained plastic film having cracks was examined by a scanning electron microscope (SEM / scanning e).
When observed with a lectron microscope), the width of the cracks was about 5 μm, and the interval between the cracks was about 12 μm. Also, the crack penetrated the plastic film.

(2) Evaluation of optical characteristics of cracked plastic film Using the obtained cracked plastic film, the relationship between the angle with respect to the light ray and the haze value was investigated. The haze values were measured when the angle between the light beam and the cracked plastic film was 70 ° and 90 °, respectively. Here, a low haze value means that a light beam in a vertical direction can pass through a cracked plastic film, and an image on the opposite side of the cracked plastic film can be clearly recognized through the cracked plastic film. Indicates what can be done. The evaluation results are shown in Table 2. In addition, the haze value was measured at a temperature of 23 ° C. and a humidity of 50% by using “Integral turbidity meter” manufactured by Tokyo Denshoku Co., Ltd.

[0027]

[Table 2]

(3) Preparation of transparent laminated body The obtained crazing-treated film has a thickness of 0.38 mm.
Polyvinyl butyral interlayer film (STEP manufactured by Sekisui Chemical Co., Ltd.
The film was sandwiched between two sheets to obtain a laminated film, and the obtained laminated film was sandwiched between float glasses having a thickness of 3 mm to obtain a transparent laminated body.

The obtained transparent laminate was placed in a rubber bag, the vacuum degree was reduced to 10 torr, the whole system was heated to 120 ° C. and held for 30 minutes, and then cooled to release the reduced pressure to obtain a transparent laminate body. Removed from rubber bag. Put the taken out transparent laminate in an autoclave, 140 ℃, 13kg
The sample was kept under a constant temperature and constant pressure of / cm ² for 20 minutes, cooled, released, and taken out. The transparent laminate taken out was in a transparent state without foaming, and the adhesion state of each layer was also good.

(4) Evaluation of Transparent Laminated Body Using the obtained transparent laminated body, haze value measurement, Panmel test, light resistance test, heat resistance test, moisture resistance test and abrasion resistance test were carried out and evaluated. did. The evaluation results are shown in Table 3.

In the Panmel test, the transparent laminate was -18
It is allowed to stand for 16 ± 4 hours at a temperature of ± 0.6 ° C, adjusted with a hammer, and the exposed degree of the laminated film after the crushed transparent plate is partially peeled It was judged by a sample.

The above light resistance test and heat resistance test are based on JIS
Performed according to R 3205. In the light resistance test, the rate of change in light transmittance after irradiation with ultraviolet rays for 1000 hours was measured.

In the above moisture resistance test, the transparent laminated body is heated at a temperature of 50.
Observed at ℃, 100% relative humidity for 2 weeks. Passed if there is no abnormality such as whitening, peeling, foaming, etc. in the part excluding the part up to 0.5 inches from the end, and reject if there is any abnormality. And

In the above abrasion resistance test, the surface of the outermost layer of the transparent laminate was rubbed 10 times with # 0000 steel wool in a circular motion and the surface condition was observed.

[0035]

[Table 3]

Example 2 Instead of the polyvinylidene fluoride film, the thickness is 25 μm.
A laminated film and a transparent laminated body were obtained in the same manner as in Example 1 except that a polyvinyl butyral film (polymerization degree: 1700) having a length of m, a width of 10 cm, and a length of 1 m was used. Was evaluated in the same manner as in Example 1. The evaluation results are shown in Tables 2 and 3.

Example 3 Instead of the polyvinylidene fluoride film, the thickness was 25 μm.
m in the same manner as in Example 1 except that a polysulfone film having a width of 10 cm and a length of 1 m (polymerization degree: 1000) was used.
A laminated film and a transparent laminated body were obtained, and the obtained laminated film and transparent laminated body were used and evaluated in the same manner as in Example 1. The evaluation results are shown in Tables 2 and 3.

Comparative Example 1 The polyvinylidene fluoride film having cracks obtained in Example 1 was used as it was without forming a transparent laminate, and evaluation was carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

Comparative Example 2 The polyvinyl butyral film having cracks obtained in Example 2 was used as it was without forming a transparent laminate, and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

Comparative Example 3 The cracked polysulfone film obtained in Example 3 was used as a film without forming a transparent laminate and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

Example 4 Two polyvinylidene fluoride films having cracks obtained in Example 1 were laminated so that the directions in which the cracks extend were orthogonal to each other, and a 250 μm thick ethylene-vinyl acetate film was placed between them. A laminated film was obtained by sandwiching the polymer intermediate film, and the obtained laminated film was used to obtain a transparent laminated body in the same manner as in Example 1. Using the obtained laminated film and transparent laminated body,
Evaluation was performed in the same manner as in Example 1, and the results are shown in Tables 4 and 5.

The visual field selection function of the transparent laminate is as follows.
The axis bisecting the transparent laminate in the crack extension direction is defined as the x-axis, and the axis bisecting the transparent laminate in the direction perpendicular to the crack extension is defined as the y-axis. The haze value when the angle between the light ray and the transparent laminate was 90 ° and 70 ° by rotating the transparent laminate was measured and evaluated.

[0043]

[Table 4]

[0044]

[Table 5]

Example 5 A laminated film and a transparent laminated body were obtained in the same manner as in Example 4 except that the two polyvinyl butyral films having cracks obtained in Example 2 were used, and the obtained laminated film and transparent laminated body were obtained. The body was used and evaluated in the same manner as in Example 4, and the results are shown in Tables 4 and 5.

Example 6 A laminated film and a transparent laminated body were obtained in the same manner as in Example 4 except that the two polysulfone films having cracks obtained in Example 3 were used, and the obtained laminated film and transparent laminated body were obtained. Was evaluated in the same manner as in Example 4, and the results are shown in Tables 4 and 5.

[0047]

Since the structure of the transparent laminate of the present invention is as described above, the invention according to claim 1 has a function of selecting a visual field in one direction and the function is deteriorated due to the inclusion of foreign matter from the outside. It is possible to obtain a transparent laminate that is stable against chemical changes such as deterioration due to oxidation, is less likely to receive an external force, and is less likely to suffer strength reduction or surface abrasion due to mechanical influences.

Further, in the invention according to claim 2, the visual field selection function is generated in two directions, and it is stable against chemical changes such as deterioration of function due to mixing of foreign substances from the outside and deterioration due to oxidation. It is possible to obtain a transparent laminate that is less likely to be subjected to an external force and is less likely to suffer strength reduction or surface abrasion due to mechanical influences.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a transparent laminate showing a state of a light ray to be inserted and a crack.

FIG. 2 shows a plastic film having a crack, x
It is a schematic diagram showing the state rotated about the axis and the y-axis, respectively.

FIG. 3 is a schematic cross-sectional view showing a process of causing cracks in a plastic film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent plate-like body 2 Intermediate film 3 Plastic film having cracks 4 Cracks 5 Rays 6 y-axis 7 x-axis 8 Practic film 9 Metal edge 10 Tensile direction

Claims (2)

[Claims] 1. A plastic film having a plurality of cracks which continuously extends in the width direction of the plastic film, penetrates in the thickness direction of the plastic film, and is present at substantially equal intervals in the longitudinal direction of the plastic film. A transparent laminated body, wherein a laminated film sandwiched by at least two intermediate films is sandwiched by two transparent plate-like bodies. 2. A laminated film in which at least two plastic films are sandwiched by at least two intermediate films are sandwiched by two transparent plate-like bodies, and cracks in each plastic film extend. A transparent laminated body, in which plastic films are laminated so that the directions are not the same.