JP2000319045A - Intermediate film for sandwich glass and sandwich glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate film for sandwich glass which obviates the appearance of a moire phenomenon even in the case of the regular arrangement and intervals of embossments, is consequently good in workability at cutting and sandwiching, is excellent in deaeratability in a preliminary press bonding stage and is, therefore, substantially free from the quality defect by the generation of the air bubbles and is suitable for obtaining the high-quality sandwich glass and the sandwich glass manufactured by using the intermediate film. SOLUTION: The intermediate film for the sandwich glass formed with a multiplicity of the embossments consisting of micro-ruggedness on both surfaces of a thermoplastic resin sheet is so formed that the arranging intervals of the embossments on the one surface vary from the arranging intervals of the embossments on another surface and is so formed that the recessed parts of the embossments of at least one surface are continuous. The sandwich glass is formed by interposing the intermediate film for the sandwich glass between at least a pair of glass and integrating the glass and the film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an interlayer film for laminated glass and a laminated glass using the interlayer film.

[0002]

2. Description of the Related Art An interlayer film for laminated glass formed by forming a plasticized thermoplastic resin such as a plasticized polyvinyl butyral resin between glass plates (hereinafter simply referred to as "intermediate film").
The laminated glass in which the glass is interposed, bonded and integrated is widely used as window glass for automobiles, aircraft, buildings and the like.

[0003] In this kind of laminated glass, an interlayer film is sandwiched between at least two glass plates, and the intermediate film is handled by passing through a nip roll (pressing roll) (handling deaeration method) or put in a rubber bag and suctioned under reduced pressure. (Depressurized degassing method) It is manufactured by performing pre-press bonding while degassing the air remaining between the glass plate and the intermediate film, and then performing heating and pressurization in an autoclave to perform main press bonding.

The above-mentioned interlayer film has good basic performances such as transparency, adhesiveness, penetration resistance and weather resistance. In addition, the interlayer film does not block each other during storage, and the interlayer film has a gap between glass plates. It is required to have good handling workability at the time of sandwiching and to have good deaeration in the pre-compression bonding step in order to eliminate the generation of air bubbles due to entrainment of air.

[0005] In order to satisfy such demands, a large number of embosses having fine irregularities are usually formed on both surfaces of the intermediate film. Examples of the form of the fine unevenness include, for example, various uneven patterns including a large number of convex portions and a large number of concave portions for these convex portions, and a large number of convex portions and a large number of concave grooves for these convex portions. Various irregular patterns are disclosed.

[0006] With respect to the shape of the emboss, various shape factors such as roughness, arrangement, size and the like have been studied. For example, in Japanese Patent Publication No. 1-37762, "a material made of a soft thermoplastic resin, At least one surface of a film or sheet having fine unevenness (embossed) surface shape used as an interlayer film for lamination has a large number of independent protrusions integrally formed with the film or sheet, and the protrusions , A thermoplastic resin intermediate film having a surface shape in which all the concave portions are continuously formed at the same level.

However, an interlayer film having embosses regularly arranged on both sides as disclosed in the above disclosure has a stripe-like shape generally called "moire phenomenon" due to interference of diffraction surfaces. A diffraction image appears.

The above-mentioned moiré phenomenon is not only unfavorable from the viewpoint of appearance, but also causes the eyes of the operator to be tired due to the change of interference fringes and the like at the time of cutting the interlayer film or at the time of the work of alignment. There is a problem that symptoms such as motion sickness are caused, and as a result, workability is reduced. Further, even when the regularly arranged emboss is an intermediate film provided only on one side, when a plurality of the embossed films are overlapped with each other, the moire phenomenon also appears, and the workability is similarly increased. There is a problem of a decline.

The moiré phenomenon is more likely to appear as the arrangement and spacing of the embosses formed on the surface of the intermediate film are more regular. For example, the distance between at least two points of the projections of each emboss becomes constant. In such an arrangement, or when the emboss arrangement on both surfaces of the intermediate film is the same, a moire phenomenon appears in most cases.

Therefore, for example, an emboss formed in a lattice pattern, a striated pattern, a radial pattern having a spread at a certain interval, or the like can be said to be an example of a typical emboss in which the moire phenomenon easily appears.

In order to cope with the problem of the appearance of the moiré phenomenon and the reduction of workability, for example, Japanese Patent Application Laid-Open
JP-A-294679 discloses a method in which a large number of protrusions having a prescribed arrangement are provided on the surface of an intermediate film, and an emboss having a finer protrusion than the protrusions is irregularly applied.

However, according to the method disclosed in the above disclosure, although the appearance of the moire phenomenon is considerably improved, embossing having finer projections than projections is applied to the projection surface and the surface where the projections are not located. Therefore, there is a problem that air is trapped in the concave portion of the emboss having the fine convex portion, and the deaeration in the pre-compression bonding step becomes insufficient.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention eliminates the appearance of the moire phenomenon even when the arrangement and the interval of the embossment are regular. And an interlayer for laminated glass suitable for obtaining a high-quality laminated glass that has good deaeration property in the pre-compression bonding step, and therefore hardly causes poor quality due to the generation of bubbles, and It is an object to provide a laminated glass manufactured using the same.

[0014]

The interlayer film for laminated glass according to the invention described in claim 1 (hereinafter referred to as "first invention") comprises a large number of embosses having fine irregularities on both surfaces of a thermoplastic resin sheet. In the laminated glass intermediate film in which is formed, the embossing arrangement interval on one surface and the embossing arrangement interval on the other surface are formed so as to be different, and at least the embossed concave portion on one surface is It is characterized by being formed so as to be continuous.

Further, the invention according to claim 2 (hereinafter referred to as “second
The laminated glass according to the "invention") is characterized in that the interlayer film for a laminated glass according to the first invention is interposed between at least a pair of glasses and integrated.

The thermoplastic resin sheet used in the first invention is not particularly limited, but examples thereof include a plasticized polyvinyl acetal resin sheet, a polyurethane resin sheet, an ethylene-vinyl acetate resin sheet, and an ethylene-vinyl acetate resin sheet. A thermoplastic resin sheet conventionally used for an intermediate film, such as an ethyl acrylate-based resin sheet or a plasticized vinyl chloride-based resin sheet, is preferably used. These thermoplastic resin sheets have adhesive,
Excellent basic performance required for interlayers such as weather resistance, penetration resistance, and transparency.

Among the above thermoplastic resin sheets, a plasticized polyvinyl acetal resin sheet represented by a plasticized polyvinyl butyral resin sheet is particularly preferably used. The thickness of these thermoplastic resin sheets may be set in consideration of the penetration resistance and the like required as a laminated glass, and is not particularly limited. It is preferably from 2 to 2 mm.

The interlayer film for laminated glass according to the first invention comprises:
In the intermediate film in which a large number of embosses composed of fine irregularities are formed on both surfaces of the thermoplastic resin sheet, the emboss arrangement intervals on one surface and the emboss arrangement intervals on the other surface are formed so as to be different from each other. In addition, it is necessary that the concave portion of the emboss on at least one surface is formed so as to be continuous.

By forming the emboss arrangement interval on one surface of the intermediate film different from the emboss arrangement interval on the other surface, even if the emboss arrangement and interval are relatively regular. Thus, the appearance of the moire phenomenon can be effectively suppressed.

In general, the appearance of the moire phenomenon is more likely to occur as the emboss arrangements and intervals on both surfaces of the intermediate film are closer to each other. Therefore, by making the arrangement interval of the emboss on one surface different from the arrangement interval of the emboss on the other surface, in other words, the arrangement interval of the emboss on one surface and the arrangement interval of the emboss on the other surface are different. Arbitrarily, it is possible to effectively suppress the appearance of the moire phenomenon even when the emboss arrangement and the interval on each surface are regular. In this case, the greater the difference between the emboss arrangement interval on one surface and the emboss arrangement interval on the other surface, the greater the effect of suppressing the appearance of the moire phenomenon.

In addition, by making the embossed concave portions of at least one surface of the intermediate film continuous, the embossed concave portions are communicated with each other, so that the deaeration in the pre-compression bonding step can be remarkably improved. The laminated glass is of high quality with almost no poor quality due to the generation of bubbles.

In general, the ease with which air is evacuated during degassing in the pre-compression bonding step is greatly affected by the continuity and smoothness of the concave portions of the emboss, and has little effect on the arrangement and spacing of the convex portions of the emboss. I do not receive. Therefore, by making the embossed recesses of at least one surface of the intermediate film continuous, the embossed recesses communicate with each other, and it is possible to effectively improve the deaeration in the preliminary pressure bonding step. As a result, it is possible to obtain a high-quality laminated glass that hardly causes poor quality due to the generation of bubbles.

The method of forming a large number of embosses made of fine irregularities on both surfaces of the thermoplastic resin sheet is not particularly limited. For example, an embossing roll method,
Conventionally known methods such as a calender roll method and a profile extrusion method are mentioned, and are preferably employed. Among them, the emboss roll method capable of obtaining a large number of embosses composed of constant fine irregularities is more preferable. Adopted to.

The embossing roll used in the embossing roll method is not particularly limited. For example, a blast treatment is performed on the surface of a metal roll using an abrasive such as aluminum oxide or silicon oxide, and then the surface of the metal roll is oversized. By performing lapping by vertical grinding etc. to reduce the peak, a roll with a fine uneven pattern formed on the roll surface, using an engraving mill (mother mill)
By transferring this uneven pattern to the metal roll surface,
A roll having a fine uneven pattern formed on the roll surface, a roll having a fine uneven pattern formed on the roll surface by etching (etching), and the like are used, and are preferably used.

The embossed concavo-convex pattern may be any pattern as long as it satisfies the above two conditions specified in the first invention, may be distributed regularly and regularly, or may be irregularly and irregularly. Although it may be distributed uniformly, it is generally preferable that the main embossed protrusions are regularly distributed. Also, the height of the projections of each embossment may be the same or different, and the depths of the depressions corresponding to these projections are also the same. Or different depths.

The shapes of the convex and concave portions of the embossment are the first.
Any shape may be used as long as it satisfies the two conditions specified in the present invention, and is not particularly limited. In general, triangular pyramids, quadrangular pyramids, cones such as cones,
Truncated cones such as truncated triangular pyramids, truncated quadrangular pyramids, and truncated cones, as well as a large number of convex parts such as pseudo pyramids with a mountain-shaped or hemispherical head, and these convex parts It is preferable that the surface has an uneven shape composed of a large number of concave portions.

Further, the dimensions of the convex and concave portions of the emboss are
Any size may be used as long as it satisfies the two conditions specified in the first invention, and is not particularly limited. Generally, the interval between the convex portions is 10 to 2000.
μm, more preferably 50 μm.
１０００1000 μm. The height of the convex portion is 5 to 5
It is preferably in the range of 00 μm, more preferably in the range of 20 to 100 μm. Furthermore, it is preferable that the length of the base of the convex portion is in the range of 30 to 1000 μm.

Next, the laminated glass according to the second invention needs to be formed by integrating the above-mentioned interlayer film for laminated glass between at least a pair of glasses.

The method for manufacturing a laminated glass according to the second invention is not special, and the interlayer film for a laminated glass according to the first invention is sandwiched between at least a pair of glasses.
As in the case of the ordinary method of manufacturing a laminated glass, first, a pre-compression bonding is performed to perform deaeration and temporary bonding, and then a final compression bonding is performed to obtain a desired laminated glass.

When a laminated glass is produced using an interlayer composed of, for example, a plasticized polyvinyl butyral resin sheet as the interlayer for a laminated glass according to the first invention, the pre-compression bonding and the final compression bonding are performed as follows. Do.

That is, in the pre-compression bonding, for example, an interlayer film for laminated glass according to the first invention is sandwiched between two transparent inorganic glass plates, and the laminate is passed through a nip roll (pressing roll), for example, at a pressure of about 2 to 10 kg. / Cm ² , temperature about 50
A method of pre-compression bonding while handling and degassing under conditions of １００100 ° C. (handling deaeration method), or placing the above-mentioned laminate in a rubber bag and connecting the rubber bag to an exhaust system to about −400 to −7
Decompression degree of 50 mmHg (absolute pressure 360 to 10 mmH
g), a method of raising the temperature while reducing the pressure by suction and pre-compression bonding at a temperature of about 50 to 100 ° C. (a vacuum degassing method) or the like is adopted.

Next, the pre-compressed laminated body is fully press-compressed by an ordinary method using an autoclave or a press at, for example, a temperature of about 120 to 150 ° C. and a pressure of about ^{2 to} 15 kg / cm ² , and a laminated glass is obtained. Manufactured.

The glass plate is not limited to an inorganic glass plate, but may be an organic glass plate such as a polycarbonate plate or a polymethyl methacrylate plate, or a combination of an inorganic glass plate and an organic glass plate. Is also good. Further, the laminated structure of the laminated glass is not only a normal three-layer structure of a glass plate / interlayer / glass plate, but also a multilayer structure of, for example, a glass plate / interlayer / glass plate / interlayer / glass plate. There may be.

[0034]

The interlayer film for laminated glass according to the first invention is an interlayer film for laminated glass in which a large number of embosses having fine irregularities are formed on both surfaces of a thermoplastic resin sheet.
Since the arrangement interval of the emboss on one surface and the arrangement interval of the emboss on the other surface are formed differently,
Since there is an arbitrary difference between the embossing arrangement interval on one surface and the embossing arrangement interval on the other surface, even when the embossing arrangement and interval are regular, there is no appearance of the moire phenomenon, and therefore, Workability at the time of cutting and joining is improved.

Further, the interlayer film for laminated glass according to the first invention is formed so that the concave portion of the embossment on at least one surface is continuous, so that the concave portion of the emboss is communicated, and the pre-compression is performed during the processing of the laminated glass. Excellent degassing in the process. Therefore, the obtained laminated glass is of high quality with almost no quality defects due to the generation of bubbles.

The laminated glass according to the second invention is characterized in that
Since it is manufactured using the interlayer film for laminated glass according to the present invention, there is almost no poor quality due to the generation of air bubbles, and the basic performance required for laminated glass such as transparency, adhesion, penetration resistance, weather resistance, etc. Excellent high quality.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 100 parts by weight of a polyvinyl butyral resin (average degree of polymerization 1700, residual acetyl group 1 mol%, butyralization degree 65 mol%) was used as a plasticizer for triethylene glycol di-2-ethyl butyrate. A rate (3GH) of 40 parts by weight was added and mixed, and the mixture was melt-kneaded by an extruder and extruded into a sheet shape from an extrusion die to obtain a polyvinyl butyral resin sheet (PVB sheet) having a thickness of 0.76 mm.

An embossing mill (mother mill) having a hemispherical embossed pattern is pressed against one metal roll surface of a pair of embossed rolls, and the metal roll and the engraving mill are rotated to change the embossed pattern of the engraving mill to a metal. Transferred to roll. Next, the engraving mill is sequentially moved in the axial direction of the metal roll in the arrangement unit of the embossing pattern, and the embossing pattern of the engraving mill is transferred to the metal roll by the same operation as described above, so that the hemispherical emboss is regularly formed. The formed embossing roll was manufactured. The emboss arrangement interval of the engraving mill was 200 μm.

Further, of the pair of embossing rolls, an engraving mill (mother mill) having a hemispherical embossed pattern is pressed against the surface of the other metal roll, and the embossing mill is embossed by rotating the metal roll and the engraving mill. The pattern was transferred to a metal roll. Next, the engraving mill is sequentially moved in the axial direction of the metal roll in the arrangement unit of the embossing pattern, and the embossing pattern of the engraving mill is transferred to the metal roll by the same operation as described above, so that the hemispherical emboss is regularly formed. The formed embossing roll was manufactured. The embossing arrangement interval of the engraving mill was 300 μm.

The PVB sheet obtained above (0.76 m
m thickness) is passed through the pair of embossing rolls obtained above, so that hemispherical embosses are regularly formed on both sides, and the embossing arrangement interval on one surface and the embossing arrangement interval on the other surface are determined. Was manufactured. FIG. 1 shows the embossed patterns on the front surface, the back surface, and the cross section of the obtained intermediate film.

(Example 2) The embossed pattern of the engraving mill (mother mill) was inscribed, and the embossing interval of one engraving mill was 250 μm, and the embossing interval of the other engraving mill was 300 μm. Except for this, in the same manner as in Example 1, the embossed lines are formed regularly on both surfaces, and the embossing arrangement interval on one surface is different from the embossing arrangement interval on the other surface. An interlayer for glass was manufactured. FIG. 2 shows the embossed patterns on the front surface, the back surface, and the cross section of the obtained intermediate film.

(Example 3) The embossing pattern of the engraving mill (mother mill) was made into a lattice shape, the embossing range interval of one engraving mill was set to 200 μm, and the embossing interval of the other engraving mill was set to 400 μm. Other than the above, in the same manner as in Example 1, lattice-shaped embosses are regularly formed on both surfaces, and the embossing arrangement interval on one surface is different from the embossing arrangement interval on the other surface. An intermediate film was manufactured. FIG. 3 shows the embossed patterns on the front surface, the back surface, and the cross section of the obtained intermediate film.

(Example 4) The embossed pattern of one engraving mill (mother mill) was formed into a line shape with an arrangement interval of 220 μm, and the embossed pattern of the other engraving mill was arranged with an interval of 320.
Except for having a lattice shape of μm, in the same manner as in Example 1, a ruled emboss is regularly formed on one surface, and a lattice emboss is regularly formed on the other surface. In addition, an interlayer film for laminated glass was manufactured in which the emboss arrangement interval on one surface and the emboss arrangement interval on the other surface were different.

(Comparative Example 1) Except that the embossed patterns of both engraving mills (mother mills) were engraved with an arrangement interval of 210 μm, the engraved embossed pattern was embossed on both sides. An interlayer film for laminated glass was manufactured in which the embosses on both surfaces were regularly formed and the spacing between the embosses was the same. FIG. 4 shows the embossed patterns on the front surface, the back surface, and the cross section of the obtained intermediate film.

With respect to the five types of interlayer films obtained in Examples 1 to 4 and Comparative Example 1, the average surface roughness (Rz) and average arrangement interval (Sm) of the embosses on each surface were determined by the following method. It was measured. The results were as shown in Table 1.

[Measurement of Rz] A conical stylus (tip radius 5 μm, radius of curvature: 5 μm, using a digital stylus electric surface roughness meter (trade name “SE-2000”, manufactured by Kosaka Laboratory Co., Ltd.))
Using an apex angle of 90 °), the ten-point average surface roughness {Rz (μm)} of the emboss on each surface of the intermediate film was measured according to JIS B-0601.

[Measurement of Sm] Observing with a microscope, the average arrangement interval ΔSm (μm)
m)｝ was measured.

The presence or absence of the moire phenomenon was evaluated for the above five types of intermediate films by the following method. The results were as shown in Table 1.

[Presence of Moiré Phenomenon] While the intermediate film was slowly and continuously moved, it was visually observed to confirm the presence of moiré phenomenon.

Next, using each of the above five types of intermediate films, pre-compression bonding is performed by the following two methods (handling deaeration method and reduced pressure deaeration method), and then final compression bonding is performed to obtain the five types of intermediate films. A laminated glass was produced.

(A) Handling and deaeration method The interlayer film is made of two transparent float glass plates (length 30 cm ×
30 cm wide x 3 mm thick), cut off the protruding part, and in a heating oven, the obtained laminate was heated at a temperature (preliminary compression temperature) of 60 ° C, respectively.
After heating to 70 ° C. and 80 ° C., pre-press bonding was performed by passing through a nip roll (air cylinder pressure 3.5 kg / cm ² , linear velocity 10 m / min).

(B) Vacuum degassing method The interlayer film is made of two transparent float glass plates (length 30 cm ×
(Weight 30 cm x thickness 3 mm), cut off the protruding part, transfer the thus obtained laminate into a rubber bag, connect the rubber bag to a suction decompression system, and heat at the outside air heating temperature and simultaneously -600 mmHg. (Absolute pressure 160m
The temperature was maintained for 10 minutes under a reduced pressure of mHg), and the laminate was heated so that the temperature (preliminary pressure bonding temperature) became 60 ° C., 80 ° C., and 100 ° C., respectively, and then returned to the atmospheric pressure to complete the preliminary pressure bonding.

Each of the laminates preliminarily pressed by the methods (a) and (b) was heated at a temperature of 14 ° C. in an autoclave.
After maintaining the temperature at 0 ° C. and the pressure of 13 kg / cm ² for 10 minutes, the temperature was lowered to 50 ° C. and returned to the atmospheric pressure to complete the final pressure bonding, thereby producing a laminated glass.

Each of the five types of laminated glass obtained above was subjected to a bake test by the following method to evaluate the deaeration in the pre-compression bonding step. The results were as shown in Table 1.

[Bake test of laminated glass] The laminated glass was heated in an oven at 140 ° C for 2 hours. Next, after taking out from the oven and allowing to cool for 3 hours, the appearance of the laminated glass was visually observed, the number of foams (bubbles) generated in the laminated glass was examined, and the degassing property was evaluated. Note that the number of test sheets was 100 each.

[0057]

[Table 1]

As is clear from Table 1, the interlayer films for laminated glass of Examples 1 to 4 according to the present invention did not show any moire phenomenon. This indicates that the workability at the time of cutting and laminating was good. Further, the laminated glass of Examples 1 to 4 produced using the above intermediate film was subjected to the baking test for both the pre-compression temperature in the handling deaeration method and the pre-compression temperature in the vacuum deaeration method. The number of foams (defective number) due to air bubbles was small. This indicates that the deaeration in the preliminary pressure bonding step was excellent.

On the other hand, in Comparative Example 1 manufactured using a pair of embossing rolls produced by two engraving mills (mother mills) having the same embossed pattern (cut line shape) and the same arrangement interval (210 μm). Although the interlayer film for laminated glass had excellent degassing properties in the pre-compression bonding step, the appearance of a moire phenomenon was observed. This indicates that the workability at the time of the cutting or the joining processing was poor.

[0060]

As described above, the interlayer film for laminated glass according to the present invention has no appearance of the moire phenomenon even when the arrangement and the interval of the emboss are regular. Therefore, workability at the time of cutting or joining processing is good. Further, since it is excellent in deaeration in the pre-compression bonding step, it is suitable for obtaining a high-quality laminated glass that hardly causes poor quality due to generation of bubbles. Therefore, the laminated glass produced using the above intermediate film is of high quality and is suitably used as a window glass of an automobile, a vehicle, an aircraft, a building or the like.

[0061]

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embossed pattern of an interlayer film for laminated glass according to Example 1.

FIG. 2 is a schematic view showing an embossed pattern of an interlayer film for laminated glass according to Example 2.

FIG. 3 is a schematic view showing an embossed pattern of an interlayer film for laminated glass according to Example 3.

FIG. 4 is a schematic diagram showing an embossed pattern of an interlayer film for laminated glass according to Comparative Example 1.

Claims (2)

[Claims] 1. In a laminated glass intermediate film in which a large number of embosses having fine irregularities are formed on both surfaces of a thermoplastic resin sheet, an emboss arrangement space on one surface and an emboss arrangement space on the other surface are determined. Are formed so as to be different from each other, and are formed so that embossed concave portions on at least one surface are continuous. 2. The method according to claim 1, further comprising the step of:
A laminated glass characterized by being integrated with an interlayer film for laminated glass as described in 1 above.