JP2001261385A - Laminated glass interlayer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an interlayer for laminated glass capable of providing a high-quality laminated glass, not causing a seal preceding phenomenon of peripheral part even without strictly controlling a degassing start temperature in a preliminary sticking process, exhibiting excellent degassing properties, not requiring a rise in heating temperature for sealing the peripheral part of a constituent unit and hardly causing quality defects by occurrence of foams even under severe conditions in an interlayer provided an uneven shape on the surface. SOLUTION: This interlayer for laminated glass is characterized in that the interlayer is provided with a great number of embosses consisting of main recessed parts and main projected parts on both sides of a thermoplastic resin sheet. The main recessed parts have a channel shape and the main projected parts have plane parts provided with auxiliary recessed parts and auxiliary projected parts finer than the main recessed parts and the main projected parts on the tops of the main projected parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interlayer film for laminated glass on which an embossed portion having fine concave portions and convex portions is formed.

[0002]

2. Description of the Related Art A laminated glass, which is formed by forming a thermoplastic resin such as a plasticized polyvinyl butyral resin between glass plates, is laminated and bonded together to form an integrated laminated glass for automobiles, aircrafts, and buildings. Widely used as window glass for objects.

[0003] In this type of laminated glass, usually, an interlayer is sandwiched between at least two glass plates, and the interlayer is handled by passing through a nip roll, or is put in a rubber bag and suctioned under reduced pressure, so that the glass plate and the interlayer are separated. It is manufactured by pre-compression bonding while degassing the air remaining in between, and then performing main compression by heating and pressurizing in an autoclave, for example.

[0004] The above-mentioned interlayer film has good basic performances such as transparency, adhesion, penetration resistance and weather resistance, as well as not blocking between interlayer films during storage and interlayer film between glass plates. Good handling work when sandwiching
Furthermore, in order to eliminate the generation of air bubbles due to entrainment of air,
Good deaeration in the pre-compression bonding step is required.

In order to satisfy the above requirements, usually,
Numerous embosses composed of fine concave portions and convex portions are formed on both surfaces of the intermediate film. As the form of the concave portion and the convex portion,
For example, various concave-convex patterns composed of a large number of convex portions and a large number of concave portions for these convex portions, various concave-convex patterns composed of a large number of convex portions and a large number of concave grooves for these convex portions, roughness, arrangement Embossed shapes having various values for various shape factors such as size, size, etc. are disclosed. However, when regular embosses are formed on both surfaces of the intermediate film, a striped diffraction image generally called a moire phenomenon appears due to interference between the diffraction surfaces.

The above-mentioned moiré phenomenon is not only unfavorable from the viewpoint of appearance, but also causes the eyes of the worker to be tired due to a change in interference fringes and the like at the time of cutting of 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.

For this reason, for example, Japanese Patent Application Laid-Open No. 9-50807
No. 8 discloses an intermediate film that eliminates the moiré phenomenon by regularly arranging grooves in the uneven shape and making the pattern at 25 ° or more, more preferably 90 °, on each surface. I have.

[0008] In the above-mentioned method, it is known that a shape provided with a 90 ° score line in order to eliminate the moire phenomenon is thermally transferred using a roll with a 45 ° score line. However, the transfer becomes less easy as the angle of the engraved line of the roll becomes larger. Generally, a vertical engraved line shape parallel to the transfer flow can be most easily formed, and the horizontal engraved line shape requires temperature control and high pressure during transfer.

In the above-mentioned method, if the temperature at the start of degassing in the pre-compression bonding step is not strictly controlled, the peripheral portion of the laminated glass structure (eg, glass / interlayer / glass) is sealed first. There is a problem that a leading edge phenomenon of the peripheral edge seal occurs and deaeration inside the structure is further insufficient.

As means for preventing the occurrence of the above-mentioned peripheral edge seal advance phenomenon, the temperature at the time of starting deaeration is controlled by the size of the concave and convex shape of the groove shape, and the seal advance at the time of crimping of the structure at the start of the deaeration. There are methods to prevent this phenomenon and to increase the roughness of the emboss.However, in this case, it is necessary to greatly increase the pre-compression temperature in the pre-compression step in order to securely seal the peripheral edge of the structure. There is a problem that occurs. Further, when the engraved lines on both surfaces of the intermediate film are made parallel from the viewpoint of moldability, there is a problem that the self-adhesiveness of the film, especially the self-adhesive force, becomes high.

[0011]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide an intermediate film having an irregular surface formed on the surface thereof without having to strictly control the deaeration start temperature during the pre-compression bonding step. No pre-sealing phenomena occur, demonstrating excellent degassing properties.Also, there is no need to raise the heating temperature to seal the peripheral edge of the component.Furthermore, even under severe conditions, air bubbles are generated. An object of the present invention is to provide an interlayer film for laminated glass that can obtain a high-quality laminated glass that hardly causes poor quality.

[0012]

The present invention relates to an interlayer film for laminated glass having a large number of embosses comprising a main concave portion and a main convex portion formed on both surfaces of a thermoplastic resin sheet. The main convex portion has a shape, and the main convex portion is an interlayer film for laminated glass having a flat portion in which a sub concave portion and a sub convex portion finer than the main concave portion and the main convex portion are formed at the top of the head. less than,
The present invention will be described in detail.

In the interlayer film for laminated glass of the present invention, a large number of embosses composed of main concave portions and main convex portions are formed on both surfaces of a thermoplastic resin sheet.

The thermoplastic resin sheet is not particularly limited, and examples thereof include a plasticized polyvinyl acetal resin sheet, a polyurethane resin sheet, an ethylene-vinyl acetate resin sheet, an ethylene-ethyl acrylate resin sheet, and a plasticized vinyl chloride. A thermoplastic resin sheet conventionally used for an intermediate film, such as a base resin sheet, may be mentioned. These thermoplastic resin sheets are excellent in basic performance required as an intermediate film such as adhesiveness, weather resistance, penetration resistance, and transparency, and are preferably used. Among them, plasticized polyvinyl butyral resin sheets are representative. Plasticized polyvinyl acetal-based resin sheet is more preferably used.

The thickness of the thermoplastic resin sheet may be set in consideration of the penetration resistance and the like required for a laminated glass, and is not particularly limited. It is preferably about 0.2 to 2 mm.

In the interlayer film for a laminated glass of the present invention, a large number of embosses composed of a main concave portion and a main convex portion are formed on both surfaces of the thermoplastic resin sheet, and the main concave portion has a groove shape. The convex portion has a flat portion on the top of which the main concave portion and the sub concave portion and the sub convex portion finer than the main convex portion are formed.

In the interlayer film for laminated glass of the present invention, the bottom of the main recess is continuous, and the main recess has a groove shape. The ease with which air is released when a laminated glass structure (laminate) composed of a combination of glass / interlayer / glass is degassed in the pre-compression bonding step is closely related to the continuity and smoothness of the bottom of the main concave portion. And there is almost no effect on the spacing or arrangement of the main projections. Therefore, by making the bottom side of the main concave portion of the intermediate film continuous, it is possible to effectively improve the deaeration in the preliminary pressure bonding step.

On the other hand, in the above-mentioned embossed shape, the volume of the main convex portion has a great influence on the crushability (crushability) of the emboss at the time of preliminary press bonding. The volume of the main projection is determined by the interval and arrangement of the main projections, the arrangement interval (pitch), and the area of the top of the main projection. The larger the area of the top of the main projection, the larger the volume. In the interlayer film for laminated glass of the present invention, the top of the main convex portion with respect to the main concave portion having the groove shape has a planar shape, that is, the cross section orthogonal to the extension direction of the main convex portion has a base. Due to the shape, the area of the top of the main projection increases, and the volume of the main projection also increases, thereby effectively suppressing the occurrence of the leading edge phenomenon of the peripheral edge seal of the glass structure in the pre-compression bonding step. be able to. Therefore, air existing near the center of the laminated glass structure in the pre-compression bonding step can also be effectively degassed. In addition, by increasing the volume of the main protrusion, the average surface roughness of the emboss can be relatively reduced. At the temperature required for the peripheral edge sealing in the pre-compression bonding step, the interlayer film for laminated glass is in a sufficiently fluid state, and if the surface roughness of the emboss is within a certain range, the peripheral edge sealing is sufficiently performed at a normal temperature. It becomes possible.

Furthermore, in the interlayer film for laminated glass of the present invention, the main concave portion and the sub concave portion and the sub convex portion finer than the main convex portion are formed on the flat portion at the top of the main convex portion. By making the top of the main convex portion a planar shape, the self-adhesiveness of the intermediate film may be increased, but the main concave portion and the sub concave portion and the sub convex portion finer than the main convex portion are formed in the flat portion. By doing
The self-adhesiveness of the obtained intermediate film can be suppressed, and the film handling property is improved.

FIG. 1 is a schematic view showing an embossed pattern (pattern of an uneven portion) of an intermediate film obtained in Examples 1 and 2 described later. In FIG. It represents the arrangement interval (pitch), and b represents the width of the flat portion of the top of the main convex portion.

In the interlayer film for laminated glass of the present invention, the ratio (b / a) of the width (b) of the flat portion of the top of the main projection to the arrangement interval {pitch (a)} of the main projection is 20% or more. It is preferred that

If the ratio b / a is less than 20%, the effect of increasing the volume of the main projection and the effect of preventing the occurrence of the leading edge seal phenomenon may not be sufficiently obtained. B /
When a becomes 100%, the main concave portion substantially disappears.
b / a is preferably less than 100%, more preferably 90% or less. The width (b) of the flat portion of the top of the main convex portion may be a constant width over the entire area of the intermediate film, or may be a partially different width, that is, a random width.

In the interlayer film for laminated glass according to the present invention, it is preferable that the interval between the main irregularities on one surface is not the same as the interval between the main irregularities on the other surface. If the intervals between the main concave and convex shapes on both surfaces are the same, the moiré phenomenon may easily occur.

In the interlayer film for a laminated glass of the present invention, the average surface roughness (Ra) of the flat portion at the top of the main convex portion is preferably 2.5 μm or more, and more preferably, the Ra is 3. 0 μm or more. The Ra is 2.
When the thickness is 5 μm or more, the contact area between the intermediate films can be reduced even when the intermediate films are combined and stored by a conventional method, so that the self-adhesiveness is at a level at which there is no problem.

However, if the area and surface roughness of the plane portion are simply increased, an air pocket is formed in the sub-concave portion in the sub-convex / convex shape formed on the plane portion, and a small amount of air remains during preliminary degassing. The small amount of residual air may cause a decrease in transmittance, that is, a decrease in transparency. Since the interlayer film has a sufficient ability to dissolve air, a decrease in the transmittance itself does not pose a significant problem, but the higher the transparency, the better from the viewpoint of management of the pre-compression bonding step. In order to ensure sufficient transparency during pre-compression bonding, it is preferable not to provide an unnecessary sub-recess on the flat portion of the top of the main protrusion.

In the interlayer film for laminated glass of the present invention, the relationship between the average surface roughness (Ra: B) of the main concave portion and the average surface roughness (Ra: A) of the main convex portion is B / A = 0. 5-2.
It is preferable to satisfy 0. The above Ra: A and R
a: B is the surface roughness defined on the average line of the roughness curve defined in JIS B-0601 “Surface roughness—definition and display”, for example, a digital stylus electric surface roughness. Total (for example, product name "Perthometer S3
P ", manufactured by Feinpuff Perthen GMBH, or a digital stylus electric surface roughness meter (for example, trade name" SE-2000 ", manufactured by Kosaka Laboratory Co., Ltd.). In the present invention, the digital stylus electric surface roughness meter “Performet”
er S3P ”, in the case of Ra: A, the tip width of the stylus is 200 μm, the facing angle is 90 °, and Ra: B
In the case of the above, the measurement was carried out by moving the stylus in a direction perpendicular to the tip width under the conditions of a tip width of the stylus of 5 μm and a facing angle of 90 °.

If the B / A is less than 0.5, it may be necessary to strictly control the deaeration start temperature at the time of preliminary press-fitting. In other words, it is possible to relax the sealing conditions at the time of preliminary press-fitting. On the contrary, if the above B / A exceeds 2.0, the deaeration at the time of preliminary press bonding may be insufficient.

In the interlayer film for laminated glass of the present invention, it is preferable that the shape of the sub-projections and depressions formed on the flat portion of the top of the main projections satisfy the relationship of 0 <Rvk / Rz ≦ 0.35. Here, Rvk means the average roughness of the valley portion falling from the central region of the sub-irregularities, and Rz means the average depth of the sub-irregularities.

When the above Rvk / Rz exceeds 0.35,
A phenomenon in which the transparency of the laminated glass laminate after the pre-compression bonding in the pre-compression bonding step is reduced may easily occur.

In the present invention, the method for forming a large number of embosses on both sides of the interlayer film for laminated glass is not particularly limited, and examples thereof include an emboss roll method, a calender roll method, and a profile extrusion method. In particular, the embossing roll method capable of quantitatively forming an embossment composed of constant fine concave portions and convex portions is preferable.

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 an excessive peak on the surface is reduced. By performing lapping using vertical grinding or the like, a fine embossed pattern (irregular pattern) is formed on the roll surface, and an engraving mill (mother mill) is used. Examples include those in which a fine uneven pattern is formed on the roll surface by transfer, and those in which a fine uneven pattern is formed on the roll surface by etching (etching).

The embossed pattern (pattern of the main concave and convex portions) in the interlayer film for laminated glass of the present invention is not particularly limited, and examples thereof include a line shape, a lattice shape, a radial shape, and a hemispherical shape.

The arrangement (distribution) of the main concave portion and the main convex portion is not particularly limited, and may be regularly distributed.
It may be distributed irregularly, but is preferably distributed regularly.

The heights of the main projections may be the same or different. Also, the depth of the main concave portion with respect to the main convex portion may be the same or different.

The original shape of the main convex portion (the shape before the flat portion is provided on the crown) is not particularly limited. For example, a triangular pyramid, a quadrangular pyramid, a cone such as a cone, a truncated triangular pyramid, Examples include truncated pyramids such as truncated pyramids and truncated cones, and pseudopyramids having a mountain-shaped or hemispherical head. Examples of the shape of the main concave portion include a shape corresponding to the main convex portion.

The dimensions of the main projections and the main recesses are not particularly limited, and the arrangement interval (pitch) of the main projections is 10 to 200.
0 μm, more preferably 50 to 1 μm.
000 μm. The height of the main projection is 5 to 500 μm.
And more preferably 20 to 100 μm
m. Further, the length of the base of the main convex portion is 30 to 1000.
μm is preferred.

In the production of the interlayer film for laminated glass of the present invention, it is preferable to form the main concavo-convex portion at a temperature lower than the temperature for forming the sub-concavo-convex portion on the flat portion at the top of the main protruding portion.

In order to obtain the interlayer film for laminated glass of the present invention, the method for forming the main concave and convex portions on both sides of the thermoplastic resin sheet is not particularly limited. By using a roll, it is only necessary to transfer onto a thermoplastic resin sheet on which sub-projections and depressions are formed in advance, but if the transfer conditions (temperature and pressure) of the main projections and depressions are too high,
The sub-projections and projections may disappear when the main projections and depressions are transferred. However, by making the formation temperature (transfer temperature) of the main uneven portion lower than the formation temperature (transfer temperature) of the sub uneven portion, the main uneven portion remains on the flat portion of the top of the main uneven portion even after the formation (transfer) of the main uneven portion. Finer sub-irregularities can be left.

The interlayer film for laminated glass of the present invention is suitably used for laminated glass. The configuration of the laminated glass is not particularly limited as long as the interlayer film for a laminated glass of the present invention is sandwiched between at least a pair of glass plates. If only a normal three-layer structure of glass plate / intermediate film / glass plate is used. Instead, a multilayer structure composed of a glass plate / interlayer / glass plate / interlayer / glass plate may be used.

The glass plate used for the laminated glass is not particularly restricted but includes, for example, ordinary inorganic glass plates and organic glass plates such as polycarbonate plates and polymethyl methacrylate plates.

The method for manufacturing a laminated glass using the interlayer film for a laminated glass of the present invention is not particularly limited, and an intermediate film is formed between at least a pair of glass plates in the same manner as in a normal method for manufacturing a laminated glass. After sandwiching and first performing pre-press bonding to perform deaeration and temporary bonding, for example, by performing main pressing in an autoclave, a desired laminated glass can be obtained.

For example, when manufacturing a laminated glass using an intermediate film made of a plasticized polyvinyl butyral resin sheet as an intermediate film for a laminated glass, specifically, pre-compression bonding and final compression bonding are performed as follows. Good.

In the pre-compression bonding, the interlayer for laminated glass of the present invention is sandwiched between two transparent inorganic glass plates, and the laminate is passed through a nip roll.
0 kPa, temperature of about 50 to 100 ° C., and pre-press bonding while degassing (handling degassing method), or placing the above-mentioned laminate in a rubber bag, connecting the rubber bag to an exhaust system, Decompression degree of 40 to -75 kPa (absolute pressure 36 to 1
kPa) by raising the temperature while reducing the pressure by suction, and pre-compression bonding at a temperature of about 60 to 100 ° C (vacuum degassing method).
And so on.

Next, the pre-pressed laminate is subjected to a conventional method using an autoclave or a press, for example, at a temperature of about 120 to 150 ° C. and a pressure of about 200 to 150 ° C.
The final compression bonding is performed under the condition of 1500 kPa to produce a laminated glass.

[0045]

The interlayer film for laminated glass of the present invention has the above-mentioned structure, and exhibits excellent degassing properties in the pre-compression bonding step. In addition, the occurrence of the phenomenon of preceding the peripheral edge seal of the laminated glass structure in the pre-compression bonding step is effectively suppressed. Therefore, air existing near the center of the laminated glass structure is also effectively degassed.

[0046]

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.

(Examples 1 to 5) (1) Production of interlayer film for laminated glass Various emboss rolls were prepared so that various emboss shapes could be given. DX as a thermoplastic resin sheet
N film (plasticized polyvinyl butyral resin sheet, Ra:
3.5 μm, Rz: 42.5 μm, Rvk: 9.8 μ
m, manufactured by Sekisui Chemical Co., Ltd.). Using a pair of rolls composed of an embossing roll and a rubber roll as a concavo-convex shape transfer device, the DXN film was passed through the concavo-convex shape transfer device under the following transfer conditions to produce an interlayer film for laminated glass having embossed shapes on both surfaces. [Transfer conditions] Temperature of DXN film: normal temperature, transfer temperature of sub uneven portion of DXN film: 130 ° C, emboss roll temperature: 130 ° C, linear velocity:
10m / min, press linear pressure: 500kPa

Table 1 shows the shapes of the embosses (shapes of the irregularities) of the interlayer films for laminated glass obtained in Examples 1 to 5. FIG. 1 shows an embossed pattern (pattern of an uneven portion) of the interlayer film for laminated glass obtained in Example 1 and Example 2, and FIG. 2 shows a laminated pattern obtained in Example 3 and Example 4. Embossed pattern of glass interlayer (pattern of irregularities)
FIG. 3 schematically shows an embossed pattern (a pattern of an uneven portion) of the interlayer film for a laminated glass obtained in Example 5.

Comparative Example 1 As a thermoplastic resin sheet,
An intermediate film for laminated glass having an embossed shape on both surfaces was prepared by performing the same operation as in the example except that a non-embossed plasticized polyvinyl butyral resin sheet having no irregularities was used.

Table 1 shows the shape of the emboss (shape of the uneven portion) of the interlayer film for laminated glass obtained in Comparative Example 1.
FIG. 4 schematically shows an embossed pattern (a pattern of an uneven portion) of the interlayer film for a laminated glass obtained in Comparative Example 1.

With respect to the six types of interlayer films for laminated glass obtained in Examples 1 to 5 and Comparative Example 1, Ra: A, Rz and Rvk were measured by the following methods. Further, the self-adhesive force of the interlayer film for laminated glass was measured to evaluate the handling workability. The results were as shown in Table 1.

[Method of measuring Ra: A, Rz and Rvk]
The digital stylus electric surface roughness meter "Perthom
eter S3P ”and a surface shape analyzer (trade name“ SAS-2010 ”, manufactured by Meishin Koki Co., Ltd.) of the above-mentioned surface roughness meter specification, in accordance with JIS B-0601, a tip width of a stylus of 200 μm, Ra: A, R under the condition of a facing angle of 90 °
z and Rvk were measured.

(2) Preparation of Laminated Glass Using each of the above six types of interlayer films for laminated glass, pre-compression bonding was performed by a vacuum degassing method as described below, followed by final compression bonding. Various kinds of laminated glass were produced.

[Vacuum method under reduced pressure]
Pieces of transparent float glass plate (30cm × 30cm)
× thickness 30cm), cut off the protruding part,
A laminated glass laminate was produced. The obtained laminated glass laminate was transferred to a rubber bag. Connect the rubber bag to the suction decompression system, and heat at the outside air heating temperature and at the same time, -60 kP
a (absolute pressure 16 kPa) under reduced pressure for 10 minutes,
After heating so that the temperature (preliminary pressure bonding temperature) of the laminated glass laminate was 70 ° C., the pressure was returned to the atmospheric pressure, and a laminated glass laminate having completed the preliminary pressure bonding was produced. In addition, the deaeration start temperature at the time of preliminary press bonding was performed under three conditions of 40 ° C, 50 ° C, and 60 ° C.

The light transmittance of the laminated glass laminate pre-compressed by the above method was measured using a trade name of Adhesion Photometer TA-707 manufactured by Tokyo Denshoku Co., Ltd. to evaluate the transparency. The results were as shown in Table 1.

[Main Compression] The laminated glass laminate pre-compressed by the above method is placed in an autoclave,
After maintaining the temperature for 10 minutes at a temperature of 1300 kPa and a temperature of 1300 kPa, the temperature was lowered to 50 ° C., and the pressure was returned to the atmospheric pressure to complete the final pressure bonding to produce a laminated glass.

(3) Evaluation A bake test was performed on the six types of laminated glass obtained above by the following method to evaluate the deaeration in the preliminary pressure 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. The number of test sheets was 100 each.

[0059]

[Table 1]

(Examples 6 to 10) An interlayer film for laminated glass was prepared in the same manner as in Examples 1 to 5 except that the embossing roll temperature at the time of producing the interlayer film for laminated glass was set to 125 ° C. Was prepared.

With respect to the five types of interlayer films for laminated glass obtained in Examples 6 to 10, R
a: A, Rz, and Rvk were measured, and Ra: B was measured under the condition that the tip width of the stylus was 5 μm and the facing angle was 90 °.
Further, the self-adhesive force of the interlayer film for laminated glass was measured to evaluate the handling workability. The results were as shown in Table 2.

Using the five types of interlayer films for laminated glass obtained above and setting the temperature (preliminary compression temperature) of the laminated glass laminate to 65 ° C. in the preliminary compression bonding step by the vacuum degassing method, In the same manner, a laminated glass laminate and a laminated glass for which pre-compression bonding was completed were produced.

The light transmittance of the laminated glass laminate obtained above was measured in the same manner as described above, and the transparency was evaluated. The laminated glass obtained above was subjected to a bake test in the same manner as described above to evaluate the deaeration. The results were as shown in Table 2.

[0064]

[Table 2]

As is clear from Tables 1 and 2, the interlayer films for laminated glass of Examples 1 to 10 all had low self-adhesive force and were excellent in handling workability. Further, the laminated glass laminates of Examples 1 to 10 produced using the above intermediate film all had high light transmittance after completion of the pre-compression bonding, and were excellent in transparency. Further, all of the laminated glasses of Examples 1 to 10 produced using the above intermediate film had a deaeration start temperature of 40 during pre-compression bonding by a reduced pressure deaeration method.
C, 50 ° C., and 60 ° C., the number of foams (defective number) due to bubbles during the bake test was small. This is because, in the pre-compression bonding step, excellent degassing properties were exhibited even if the deaeration start temperature was not strictly controlled and the normal pre-compression bonding temperature (70 ° C) was not particularly increased. Is shown. In addition, R of the plane part of the top of the main convex part
The interlayer films for laminated glass of Examples 4, 5, 9, and 10 in which a was less than 2.5 μm were the laminated glass of Examples 1 to 3 and Examples 6 to 8. Although the self-adhesive force was slightly higher than that of the intermediate film for use, it was judged that the level was not a problem in practical use.

On the other hand, the ratio of the width of the flat portion of the top of the main projection to the spacing (pitch) of the main projections (b / a) was less than 20% without the sub-projections and depressions. The interlayer film for laminated glass had an extremely high self-adhesive force and was poor in handling workability. In the case of the laminated glass of Comparative Example 1 produced using the interlayer film for laminated glass, when the degassing start temperature in the pre-compression bonding step is 50 ° C. or more, the number of bubbles (defective number) due to bubbles during the bake test is extremely low. There were many. This is because, in the pre-compression bonding step, unless the deaeration start temperature is strictly controlled to at least less than 50 ° C., a peripheral edge precedence phenomenon of the laminated glass laminate occurs, and air existing near the center of the laminated glass laminate is generated. Does not degas enough.

[0067]

As described above, the interlayer film for laminated glass according to the present invention causes a peripheral edge precedent phenomenon even though it is not necessary to strictly control the deaeration start temperature in the pre-compression bonding step. Demonstrate excellent deaeration without any. Therefore, it is possible to obtain a high-quality laminated glass which is excellent in workability at the time of producing a laminated glass and hardly causes poor quality due to generation of bubbles even under severe conditions. Further, the interlayer film for laminated glass of the present invention is excellent in handling workability since the self-adhesive force is suppressed low, and also excellent in transparency after pre-compression bonding.

The laminated glass produced using the interlayer film for laminated glass of the present invention is of high quality which hardly causes poor quality due to generation of bubbles even under severe conditions. Used for window glass of aircraft, aircraft, buildings and the like.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embossed pattern (a pattern of an uneven portion) of an interlayer film for laminated glass obtained in Example 1 and Example 2.

FIG. 2 is a schematic diagram showing an embossed pattern (a pattern of an uneven portion) of an interlayer film for laminated glass obtained in Example 3 and Example 4.

FIG. 3 is a schematic diagram showing an embossed pattern (a pattern of an uneven portion) of an interlayer film for laminated glass obtained in Example 5.

FIG. 4 is a schematic diagram showing an embossed pattern (a pattern of an uneven portion) of an interlayer film for a laminated glass obtained in Comparative Example 1.

[Description of Signs] a Interval (pitch) of arrangement of main projections b Width of flat portion at the top of main projection c Width of main depression

Claims (7)

[Claims] 1. An interlayer film for laminated glass having a large number of embosses comprising a main concave portion and a main convex portion formed on both surfaces of a thermoplastic resin sheet, wherein the main concave portion has a groove shape, and An intermediate film for laminated glass, characterized in that the portion has a flat portion on the top of which a sub-recess and a sub-projection smaller than the main depression and the main projection are formed. 2. The interlayer film for laminated glass according to claim 1, wherein the ratio of the width of the flat portion of the top of the main projection to the arrangement interval (pitch) of the main projection is 20% or more. 3. The average surface roughness (R) of the flat portion of the top of the main convex portion.
2. The method according to claim 1, wherein a) is at least 2.5 μm.
Or the interlayer film for laminated glass according to claim 2. 4. The average surface roughness (R) of the flat portion of the top of the main convex portion
2. The method according to claim 1, wherein a) is not less than 3.0 μm.
Or the interlayer film for laminated glass according to claim 2. 5. The relationship between the average surface roughness of the main concave portion (Ra: B) and the average surface roughness of the main convex portion (Ra: A) is B / A = 5.
The interlayer film for laminated glass according to any one of claims 1 to 4, wherein the interlayer film satisfies 0.5 to 2.0. 6. The method according to claim 1, wherein the shape of the sub-projections and depressions formed on the plane portion of the top of the main projections satisfies the relationship of 0 <Rvk / Rz ≦ 0.35. The interlayer film for laminated glass according to 1. 7. The method according to claim 1, wherein, in producing the interlayer film for laminated glass, the main uneven portion is formed at a temperature lower than a temperature at which the sub uneven portion is formed on the flat portion at the top of the main convex portion. Item 7. The interlayer film for laminated glass according to any one of Items 6.