JP2000319046A - Interlayer for laminated glass and laminated glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interlayer film for laminated glass which is excellent in deaeration in a pre-compression bonding step and is therefore suitable for obtaining a high-quality laminated glass which hardly causes poor quality due to generation of bubbles, and the interlayer film. An object of the present invention is to provide a laminated glass manufactured by using the method. SOLUTION: An interlayer film for laminated glass having a large number of embosses formed on at least one surface thereof, wherein a film thickness of a portion far from the peripheral portion is larger than a film thickness of a portion near the peripheral portion of the intermediate film. Or a difference between a film thickness (C) of a portion far from the peripheral portion of the interlayer film for laminated glass and a film thickness (E) of a portion near the peripheral portion of the interlayer film (E). a) satisfies the relationship of 0 μm <a ≦ 100 μm, and the interlayer film for laminated glass according to any one of the above is interposed between at least a pair of glasses and integrated. A laminated glass characterized by being formed by:

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 Conventionally, laminated safety glass (hereinafter simply referred to as "laminated glass") has been widely used as window glass for automobiles, buildings and the like. The laminated glass has, for example, an intermediate film formed of a transparent and flexible adhesive synthetic resin such as a plasticized polyvinyl butyral resin, a polyurethane resin, and a silicone resin interposed between at least a pair of glasses. It is produced by bonding and integrating. When such a laminated glass is shocked from the outside, the glass part is broken, but the interlayer film interposed between the glass is not easily broken,
In addition, since the broken glass is adhered to the interlayer film, the glass fragments are less likely to be scattered, and the human body in a vehicle such as a vehicle such as an automobile or a house or the like is injured by the glass fragments. It is possible to prevent it, and thus the security is high.

[0003] Generally, in the production of the above laminated glass, a laminated body having an interlayer film interposed between at least two pieces of glass is pre-pressed under reduced pressure to remove air remaining between the layers, and then heated. This is performed by applying pressure to the glass and bonding the interlayer and the interlayer together to integrate them.

[0004] The interlayer film used for the laminated glass should not block between the interlayer films during storage, should have good workability when laminating the glass and the interlayer film, Various performances such as excellent deaeration are strongly required.

[0005] The above-mentioned various properties required for the intermediate film depend not only on the type and viscoelastic properties of the adhesive synthetic resin which is the main component of the intermediate film, but also largely on the surface shape of the intermediate film. In order to enhance the degassing property during the pre-compression bonding under reduced pressure, it has been conventionally performed to provide a large number of fine irregularities generally called embosses on at least one surface of the intermediate film.

[0006] The conventional emboss is formed in a uniform shape on at least one surface of the intermediate film, and the bottom (recess) of the emboss is formed on the intermediate film in order to perform deaeration at the time of preliminary press-bonding more smoothly. It is made to communicate over the whole surface.

However, since the conventional intermediate film has the same thickness at all portions, the adhesion between the glass and the intermediate film by heating and pressing at the time of preliminary pressure bonding under reduced pressure is as follows. For example, due to the elasticity of the rubber constituting the rubber bag used in the pre-compression bonding, a portion closer to the periphery of the laminated glass is stronger than a portion farther from the periphery of the laminated glass, that is, a portion closer to the center of the laminated glass. Pressed.

Therefore, at a stage where air existing in a portion near the center of the laminated glass is not sufficiently degassed, the peripheral portion of the laminated glass or a portion near the peripheral edge is bonded first,
The degassing path is lost, and air existing in a portion near the center of the laminated glass tends to remain as residual air in the laminated glass. As a result, foaming occurs during the pre-compression bonding step or the final compression bonding step during heating or with the passage of time (elapsed time), resulting in poor appearance or penetration resistance and moisture resistance due to a change in the adhesive strength between the glass and the intermediate film. However, there is a problem that the durability and the like are lowered.

In order to cope with the above problems, various methods for sufficiently deaerating the laminated glass have been studied. For example, Japanese Patent Application Laid-Open No. 3-75246 discloses that "a thermoplastic intermediate resin is sandwiched between a pair of glass plates. When manufacturing a laminated body with a film interposed, the peripheral edge of the laminated body is sucked, and the laminated body is sequentially pressed outward from the center of the surface of the laminated body to increase the pressure, thereby bonding the laminated glass. In addition, a laminated glass bonding apparatus "has been proposed.

However, the method for bonding laminated glass according to the above proposal requires a special bonding device having a large number of pressure chambers, and it is necessary to sequentially press outward from the center of the surface of the laminate to increase the pressure and bond the laminate. There is a problem that the bonding work is complicated and the workability is not good.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention is to provide a high-quality laminated glass which is excellent in deaeration in a pre-compression bonding step and therefore hardly causes poor quality due to generation of bubbles. An object of the present invention is to provide an interlayer film for laminated glass suitable for obtaining, and a laminated glass manufactured using the interlayer film.

[0012]

An interlayer film for laminated glass according to the invention described in claim 1 (hereinafter referred to as "first invention") has a laminated film in which a large number of embosses are formed on at least one surface. The intermediate film for glass is characterized in that the thickness of a portion far from the peripheral portion is thicker than that of a portion near the peripheral portion of the intermediate film.

The invention according to claim 2 (hereinafter referred to as “second
The interlayer film for laminated glass according to the present invention is a film thickness (C) at a portion far from the peripheral portion of the interlayer film and a film thickness (E at a portion near the peripheral portion of the interlayer film according to the first invention. ) Satisfies the relationship of 0 μm <a ≦ 100 μm.

Further, the invention according to claim 3 (hereinafter referred to as "the invention")
The laminated glass according to the "third invention") is formed by interposing the interlayer for laminated glass according to any one of the first invention and the second invention between at least a pair of glasses and integrating them. It is characterized by.

The first invention and the second invention (hereinafter referred to as "the present invention")
Is used as the main component, a transparent adhesive synthetic resin is used as a main component, and the kind of the adhesive synthetic resin is not particularly limited. For example, polyvinyl butyral resin, polyvinyl Formal resin, polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, polyurethane resin, silicone resin, and the like are preferably used. Among them, the average degree of polymerization of 1,000 to 2,000, which is plasticized by adding a plasticizer, is used.
Polyvinyl butyral resin having an average degree of butyralization of about 50 to 70 mol% is more preferably used.

The above-mentioned adhesive synthetic resins may be used alone or in combination of two or more.

The type of the plasticizer added as needed to plasticize the adhesive synthetic resin is not particularly limited, but, for example, triethylene glycol-di-2-ethylbutyrate Monobasic acid ester plasticizers such as triethylene glycol-di-2-ethylhexanoate, triethylene glycol-dicapronate, triethylene glycol-di-n-octoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol A polybasic acid ester-based plasticizer such as adipate can be used, and is preferably used.

The above plasticizers may be used alone or in combination of two or more.

The amount of the plasticizer is not particularly limited. For example, when the adhesive synthetic resin is the polyvinyl butyral resin, 30 to 70 parts by weight of the plasticizer is added to 100 parts by weight of the polyvinyl butyral resin. It is preferred that If the added amount of the plasticizer is less than 30 parts by weight based on 100 parts by weight of the polyvinyl butyral resin, the penetration resistance of the laminated glass produced by using the obtained intermediate film may be insufficient, and conversely, polyvinyl butyral If the amount of the plasticizer exceeds 70 parts by weight based on 100 parts by weight of the resin, the plasticizer bleeds out of the obtained intermediate film, and the adhesiveness to glass and the transparency of the laminated glass may be reduced.

The interlayer film for laminated glass according to the present invention may contain, if necessary, an ultraviolet absorber, a light stabilizer, an antioxidant, an adhesion regulator, a surfactant, as long as the object of the present invention is not hindered. One or more of various additives such as a coloring agent and a coloring agent may be added.

The method for producing an interlayer film for a laminated glass according to the present invention is not particularly limited. For example, one or more of polyvinyl butyral resin, a plasticizer, and various additives which are added as necessary. After uniformly kneading a mixture containing the above-mentioned components, a conventional method of forming a film into a sheet by an extrusion molding method, a calendar molding method, a press molding method, or the like may be used.

The thickness of the intermediate film is not particularly limited, but is preferably about 0.1 to 1 mm, more preferably about 0.3 to 0.8 mm.

The average height of a large number of embosses formed on at least one surface of the interlayer film for laminated glass according to the present invention is not particularly limited, but may be 10 to 50 μm.
m, more preferably 20 to 4
It is about 0 μm.

The interlayer film for laminated glass according to the first invention comprises:
It is necessary that the thickness of a portion far from the peripheral portion is thicker than that of a portion near the peripheral portion of the intermediate film.

By making the film thickness of the part far from the peripheral part thicker than that of the part near the peripheral part of the intermediate film, in the pre-compression bonding step at the time of producing a laminated glass using the intermediate film, It is possible to prevent the peripheral portion of the glass or a portion near the peripheral portion from being bonded earlier. Therefore, the degassing path of the air existing in the part far from the peripheral edge of the laminated glass, that is, in the part near the central part of the laminated glass is not lost, and the air existing in the part near the central part of the laminated glass is also smooth. Can be degassed.

The interlayer film for a laminated glass according to the second invention is the interlayer film for a laminated glass according to the first invention, wherein the film thickness at a portion far from the peripheral portion of the interlayer film and the film at a portion near the peripheral portion are different. The difference (a) from the thickness (E) is 0 μm <a
It is necessary to satisfy the relationship of (ie CE) ≦ 100 μm.

When the a (CE) is 0 μm or less,
When the effect of improving the deaeration property in the pre-compression bonding step cannot be obtained, and when the above-mentioned a (CE) exceeds 100 μm, it takes a long time to bond the peripheral portion of the laminated glass or a portion close to the peripheral portion in the pre-compression bonding step. As a result, the productivity in the pre-compression bonding step may decrease.

Film thickness (C) at a portion far from the peripheral edge of the intermediate film
A (C−E) between the thickness and the film thickness (E) of the portion near the periphery
However, by satisfying the relationship of 0 μm <a (C−E) ≦ 100 μm, degassing of air existing in a portion near the center of the laminated glass can be performed more smoothly without lowering the productivity in the pre-compression bonding step. Can be performed.

Next, the laminated glass according to the third aspect of the present invention provides the laminated glass according to the first aspect of the present invention or the second aspect of the present invention as described above, between at least a pair of glasses.
It is necessary that the interlayer film for laminated glass according to any of the inventions be interposed and integrated.

The method for manufacturing a laminated glass according to the third invention is not special, and an interlayer for laminated glass according to any one of the first invention and the second invention is sandwiched between at least a pair of glasses. As in the case of the glass manufacturing method, first, pre-press bonding is performed to perform deaeration and temporary bonding, and then main pressing is performed to obtain a desired laminated glass.

As an interlayer for laminated glass according to the first or second invention, for example, when an interlayer formed of a polyvinyl butyral resin plasticized with a plasticizer is used, The preliminary compression and the final compression may be performed as described above.

That is, in the pre-compression bonding, for example, the interlayer film for laminated glass according to either the first invention or the second invention is sandwiched between two transparent inorganic glass plates, and this laminate is put in a vacuum bag made of rubber, for example. The vacuum bag is connected to an exhaust system, and the temperature is increased while reducing the suction pressure so that the degree of decompression is, for example, about -400 to -750 mmHg (absolute pressure 360 to 10 mmHg). A pressure bonding method (vacuum deaeration method) or a method in which the laminate is passed through a nip roll (pressing roll), for example, at a pressure of about 2 to 10
It may be carried out by a method of pre-compression bonding while handling and degassing at a temperature of about 50 to 100 ° C. under a condition of kg / cm ² (handling deaeration method). The advantage obtained by using the intermediate film for use is more remarkable in the case of the vacuum degassing method.

Next, the pre-compressed laminate is subjected to a regular press using an autoclave or a press at a temperature of, for example, about 120 to 150 ° C. and a pressure of about ^{2 to} 15 kg / cm ² , to produce a laminated glass. Is done.

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 composed of a glass plate / intermediate film / glass plate, but also a multilayer structure composed of, for example, glass plate / intermediate film / glass plate / intermediate film / glass plate. There may be.

[0035]

The interlayer film for a laminated glass according to the first invention is an interlayer film for a laminated glass having a large number of embosses formed on at least one surface thereof. Since the thickness of the part far from the peripheral part (that is, the part close to the center part of the intermediate film) is made thicker, in the pre-compression bonding step, the part near the peripheral part or the peripheral part of the laminated glass is better. It is not bonded before the center portion of the intermediate film or a portion near the center portion. Therefore, the escape route of the air existing in the central part or the part near the central part of the laminated glass is not lost, and the air existing in the above-mentioned part can be smoothly deaerated. As a result, it is possible to obtain a high-quality laminated glass that hardly generates bubbles (foaming) due to residual air.

The interlayer film for a laminated glass according to the second invention is the same as the interlayer film for a laminated glass according to the first invention, except that the film thickness at a portion far from the peripheral portion of the interlayer film (a portion near the center portion of the interlayer film) is different from the film thickness. Since the difference from the film thickness at a portion near the peripheral portion is set to be in a specific range, the above-described more remarkable effect of improving the deaeration can be obtained without lowering the productivity in the pre-compression bonding step.

Further, the laminated glass according to the third invention is:
Since it is manufactured using the interlayer film for laminated glass according to any one of the first and second aspects of the present invention, it is of high quality with almost no defective quality due to generation of bubbles.

[0038]

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)

(1) Preparation of interlayer film for laminated glass Polyvinyl butyral resin (average degree of polymerization 1700, butyralization degree 65 mol%, residual vinyl alcohol group content 34 mol%, residual acetyl group content 1 mol%) as an adhesive synthetic resin ) 40 parts by weight of triethylene glycol di-2-ethylbutyrate as a plasticizer, 0.04 parts by weight of magnesium acetate as an adhesion modifier and 2 parts by weight of 100 parts by weight.
0.02 parts by weight of ethyl butyric acid, an ultraviolet absorber and an antioxidant were further added, and the mixture was supplied to a mixing roll and kneaded. Next, using a press molding machine, the kneaded material obtained above was subjected to press molding at a temperature of 150 ° C. and a pressure of 100 kg / cm ² for 30 minutes to form an interlayer film for laminated glass having a large number of embosses formed on both surfaces. Produced. The film thickness in the vicinity of the center and the periphery of the obtained intermediate film is adjusted over a wide range using an electronic micrometer (model "K-306A", manufactured by Anritsu Electric Co., Ltd.).
As a result, the film thickness near the center was 750 μm.
m, and the film thickness near the periphery was 730 μm.

(2) Production of Laminated Glass The interlayer film for laminated glass obtained above, on which a large number of embosses are formed on both sides, is mounted on glass at room temperature immediately after the embossing is formed. When the temperature became lower than or equal to ° C., a glass at room temperature was laminated on the intermediate film and inserted into a rubber vacuum bag. Then, the air was suctioned and deaerated through the suction port of the vacuum bag to reduce the pressure to 500 mmHg.
After the temperature was raised to 0 ° C. in 5 minutes, it was held at 80 ° C. for 10 minutes while continuing suction and deaeration, and pre-compression bonding was performed. afterwards,
After cooling the vacuum bag to 50 ° C. or lower, the reduced pressure was released, and the laminate was taken out of the vacuum bag to produce a laminated glass semi-finished product. Then, the obtained laminated glass semi-finished product was heated and pressurized in an autoclave by a conventional method and subjected to final pressure bonding to produce a laminated glass.

(3) Evaluation The semi-finished laminated glass obtained above was evaluated for the visible light transmittance and the heat resistance (baking test) of the laminated glass by the following methods. The results were as shown in Table 1.

Visible light transmittance: JIS R-3212
The visible light transmittance (%) near the center of the semi-finished laminated glass was measured in accordance with the “Test Method for Safety Glass for Automobiles”. The measurement was performed at n = 9, and the average value was calculated.

Heat resistance (bake test): JIS R-
In accordance with 3205 “Laminated Glass”, laminated glass 5
After leaving 0 sheets in an atmosphere of 120 ° C. for 2 hours, the sheets were taken out, visually observed for the presence or absence of foaming, and the number of foaming sheets out of 50 sheets was regarded as heat resistance (number of foamed sheets / 50 sheets).

(Example 2) In the production of an interlayer film for laminated glass, the film thickness was set so as to be 760 μm near the center of the interlayer and 720 μm near the periphery. Except for the above, an interlayer film for laminated glass, a semi-finished laminated glass product and a laminated glass were obtained in the same manner as in Example 1.

(Example 3) In the production of an interlayer film for laminated glass, the film thickness was set so as to be 770 μm near the center portion of the interlayer film and 710 μm near the peripheral portion. Except for the above, an interlayer film for laminated glass, a semi-finished laminated glass product and a laminated glass were obtained in the same manner as in Example 1.

(Example 4) In the production of the interlayer film for laminated glass, the film thickness was set so as to be 790 μm near the center of the interlayer and 690 μm near the periphery. Except for the above, an interlayer film for laminated glass, a semi-finished laminated glass product and a laminated glass were obtained in the same manner as in Example 1.

(Comparative Example 1) In the production of an interlayer film for laminated glass, the thickness was set so that the thickness near the center of the interlayer was 720 μm, and the thickness near the periphery was 760 μm. Except for the above, an interlayer film for laminated glass, a semi-finished laminated glass product and a laminated glass were obtained in the same manner as in Example 1.

(Comparative Example 2) In the production of the interlayer film for laminated glass, the film thickness in the vicinity of the center portion and the film thickness in the vicinity of the periphery of the interlayer film were both set to 740 μm. In the same manner as in the above, an interlayer film for a laminated glass, a semi-finished product of a laminated glass, and a laminated glass were obtained.

The visible light transmittance of the five types of laminated glass semi-finished products obtained in Examples 2 to 4 and Comparative Examples 1 and 2, and the heat resistance (baked) of the five types of laminated glass obtained above Test) was evaluated in the same manner as in Example 1. The results were as shown in Table 1.

[0051]

[Table 1]

As is clear from Table 1, the laminated glass semi-finished products of Examples 1 to 4 manufactured using the interlayer films for laminated glass of Examples 1 to 4 according to the present invention are all visible near the center. Light transmittance was high. This indicates that air existing near the center was sufficiently degassed in the pre-compression bonding step.

Further, the laminated glasses of Examples 1 to 4 produced using the interlayer films for laminated glass of Examples 1 to 4 according to the present invention can be used even after the baking test which is left in an atmosphere of 120 ° C. for 2 hours. No foaming occurred, and in each case, the heat resistance was extremely excellent. This indicates that the deaeration in the preliminary pressure bonding step was sufficiently and smoothly performed.

On the other hand, the film thickness near the center (720 μm)
m) was smaller than the film thickness (760 μm) in the vicinity of the peripheral portion, and the interlayer film of Comparative Example 1 in which the film thickness in the vicinity of the center portion and the periphery was the same (740 μm). Comparative Example 1 manufactured using an interlayer film for glass
The semi-finished laminated glass of Comparative Example 2 had a low visible light transmittance near the center. This indicates that the air existing near the central portion was not sufficiently degassed in the preliminary pressure bonding step.

The laminated glass of Comparative Example 1 and Comparative Example 2 similarly produced using the interlayer film for laminated glass of Comparative Example 1 and Comparative Example 2 was subjected to a bake test left for 2 hours in an atmosphere of 120 ° C. Later, 4% per sheet (Comparative Example 2)
To about 10% (Comparative Example 1). This indicates that the degassing in the preliminary pressure bonding step was insufficient.

[0056]

As described above, in the interlayer film for laminated glass according to the present invention, the film thickness of a portion far from the peripheral portion (that is, a portion near the center portion) is larger than that of a portion near the peripheral portion. Since it is made thick, it exhibits excellent degassing properties without reducing productivity in the pre-compression bonding step. Therefore, it is suitable for obtaining a high-quality laminated glass that hardly causes poor quality due to generation of bubbles (foaming) during heating or over time.

The laminated glass according to the present invention produced using the interlayer film for laminated glass is of high quality and is suitably used as window glass for automobiles, vehicles, aircraft, buildings and the like.

Claims (3)

[Claims] 1. An intermediate film for laminated glass having a large number of embosses formed on at least one surface thereof, wherein the intermediate film has a film thickness at a portion farther from the peripheral portion than at a portion closer to the peripheral portion of the intermediate film. An interlayer for laminated glass, characterized in that it is thicker. 2. The difference (a) between the film thickness (C) of a portion far from the peripheral portion of the intermediate film and the film thickness (E) of a portion near the peripheral portion.
Satisfies the relationship of 0 μm <a ≦ 100 μm, wherein the interlayer film for laminated glass according to claim 1, wherein 3. The method according to claim 1, wherein at least between the pair of glasses.
A laminated glass characterized by being interposed and integrated with the interlayer film for laminated glass according to claim 2.