JP3327990B2 - Interlayer for laminated glass - Google Patents

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. More specifically, the present invention relates to an interlayer film that is inserted between two glass plates to form a laminated glass, and particularly has good workability at the time of laminating processing, good sealing performance with glass, comprehensive deaeration such as prevention of advance of sealing. The present invention relates to an interlayer film for laminated glass.

[0002]

2. Description of the Related Art A laminated glass is a laminated glass comprising a laminated body in which an interlayer is inserted between two glass sheets. The laminated glass has an excellent feature that it is strong and hard to be broken. It is a safe glass material that does not shatter. For this reason, it is widely used as window glass for transportation equipment such as automobiles and aircraft, and buildings.

[0003] When manufacturing this laminated glass, an interlayer made of an adhesive thermoplastic resin is inserted between two glass plates, and the obtained laminate is pre-pressed to remove air remaining between the layers. After degassing, the laminate is completely pressure-bonded to completely adhere the laminate.

[0004] The interlayer used for the above laminated glass is
In addition to the fact that the interlayer films do not block each other during storage, the workability when laminating the glass and the interlayer film is good, and the deaeration in the preliminary pressure bonding step is required to be good. . In particular, the deaeration during pre-pressing affects the quality of the laminated glass.If the deaeration is insufficient, the transparency of the obtained laminated glass may be impaired, or bubbles may be generated when the accelerated test is performed. is there.

[0005] The overall performance of an interlayer including degassing properties as described above depends on the type of thermoplastic resin as a material and physical properties such as viscoelasticity. Is a major factor in determining its overall performance.

In particular, it is known that it is effective to form a large number of fine irregularities called embosses on the surface of an intermediate film, and an intermediate film having an embossed surface is conventionally used. Examples of the form of the emboss include, for example, those in which irregularities having random sizes and shapes are formed, and those in which a large number of lattice-shaped grooves are formed.

The conventional interlayer having such an embossed surface formed thereon is effective in preventing blocking between the layers and improving the workability when the interlayer is overlapped with the glass plate. In addition, a certain effect is also observed in the deaeration in the pre-compression bonding step. However, in recent years, for example, a conventional interlayer film has not been used in a conventional interlayer film due to an increase in a glass pair difference due to an increase in demand for difficult-shaped laminated glass such as a three-dimensional curved surface having a large radius of curvature, and an increase in a linear speed in a laminating process accompanying an improvement in productivity. Degassing has not always been satisfactory. For this reason, bubbles are left between the glass plate and the interlayer due to insufficient degassing properties, or a completely transparent laminated glass cannot be obtained due to insufficient adhesiveness (sealability), It had drawbacks such as foaming after the accelerated test.

The following prior arts have been proposed to improve the deaeration of such interlayer films for laminated glass. For example, in Japanese Patent Publication No. 1-32767,
As shown in FIG. 1, there is disclosed a laminated glass in which an intermediate film 5 having a large number of independent projections 2 formed on the surface of a sheet 1 and a glass plate 4 are laminated. In the interlayer film 5 of the laminated glass, the bottom sides of the concave portions 3 formed between the adjacent protrusions 2 are all at the same level, and the concave portions 3 are formed so as to be continuous. The invention described in the same publication is
By adopting such a configuration, the anti-blocking property between the interlayer films and the workability when overlapping the glass plate and the interlayer film are improved. The shape of the protrusion 2 is a weight or a pseudo weight.

Japanese Patent Publication No. 54-21209 (US Pat. No. 5,787,710) also discloses an intermediate film having a large number of independent projections formed on the surface of a sheet. In this intermediate film, irregularities are formed such that the depth of the concave portion formed between the projections is within a predetermined range.

[0010]

However, the conventional interlayer film as described above is still insufficient in deaeration in the pre-compression bonding step. In particular, in the intermediate film described in Japanese Patent Publication No. 54-21209, the depths of the recesses formed on the sheet surface are almost the same, and thus the deaeration during the production of laminated glass is good. It cannot be said that. This seems to be the result of not paying any attention to the shape of the irregularities formed on the surface of the intermediate film.

In addition, the above-mentioned conventional interlayer film has an insufficient degree of crushing of the emboss, and causes foaming and the like after the main pressure bonding step. That is, the step of pre-pressing the glass plate and the intermediate film tends to be performed at a considerably high speed in recent years. Particularly, when deaeration is performed by a nip roll, the projections formed on the sheet surface smoothly discharge air. It must be something that causes it. For this reason, in order to secure the adhesiveness (sealability) with glass, the embossed surface is easily crushed under pressure (about 5 to 10 kg / cm ² ) and temperature (about 50 to 100 ° C.) at the time of pre-pressing. It is required to have a shape.

However, the emboss is too easily crushed,
If it collapses before reaching the above pre-pressing conditions, it will be in a peripheral part uneven adhesion state called a seal precedence, an air accumulation state will occur, and as a result, seal breakage will occur due to accumulated air, and foaming etc. after the final pressure bonding process Failure occurs.

[0013] Also, in the case of performing deaeration by vacuum pre-pressing due to decompression in the rubber bag, in order to avoid foaming due to a preceding peripheral seal, it is necessary to reduce the deaeration resistance and balance the crushability of the emboss. Need to take.

Accordingly, the present invention provides an interlayer film for a laminated glass capable of producing a laminated glass having a good balance of the ease of air escape and the ease of emboss collapse, excellent deaeration, and good transparency. The purpose is to:

[0015]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, a laminated glass having a large number of fine projections (embosses) provided on at least one surface of a film or sheet made of a thermoplastic resin. The above object was achieved by improving the shape of the emboss in the intermediate film for laminated glass, and an intermediate film for laminated glass excellent in comprehensive degassing was realized.

That is, the invention described in claim 1 of the present invention is an intermediate for laminated glass in which a large number of fine projections (embosses) are provided on at least one surface of a film or sheet made of a thermoplastic resin. In the film, the emboss is composed of a main emboss and a sub-emboss, and the main emboss has a relatively uniform shape, an area S [× 10 ⁻⁸ cm ² ] at the bottom of the protrusion, and an average distance P between the protrusions.
[Μm] and 1.5 ≦ P / S × 100 ≦ 5.5, and the average roughness of the sub-emboss is less than half of the main emboss.

Here, when the value of P / S × 100 is smaller than 1.5, the resistance to the movement of air at the time of preliminary press becomes large. Occurs. In addition, under these conditions, the protruding portion is less likely to be crushed, resulting in poor sealing, resulting in problems such as foaming and baking after the final pressure bonding. On the other hand, P / S × 100
Is greater than 5.5, the glass and the intermediate film adhere to each other before the internal air is exhausted in the peripheral portion of the glass (before the edge seal), and air bubbles remain even after the main compression. The value of P / S × 100 is preferably 2.5 to 4.
5 range.

[0018] Claim 2 of the present invention
The invention described in (1) is an interlayer film for laminated glass comprising a thermoplastic resin sheet or film having a large number of fine irregularities (embosses) on at least one surface, wherein the emboss is formed from a coarse main emboss and a fine sub-emboss. And the area S [×
10 ^-8 cm ² ], the average interval (apparent pitch) P [μm] of the protrusions, the average roughness R, and the area S ′ [× 10 ^-8 cm ² ] of the base of the protrusion of the sub-emboss. The average spacing (apparent pitch) P ′ [μm] and the average roughness R ′ of the protrusions are configured to satisfy the following relationships (1) to (3). 1/180 <S '/ S <1/2 (1) 1/11 <P' / P <2/5 (2) 1/6 <R '/ R <1/2 (3)

When the value of S '/ S is 1/180 or less, P' / P
When the value of R ′ / R is 2/5 or more or the value of R ′ / R is 1/6 or less, the glass and the interlayer come into close contact with each other around the glass before the internal air is discharged (the edge seal precedes). Air bubbles remain after departure and arrival. In addition, the self-adhesive force between the interlayer films and the sliding resistance between the glass and the interlayer film increase, which greatly impairs the workability in processing the laminated glass.

When the value of S '/ S is 1/2 or more, and P' / P is 1
When / 11 or less or R '/ R is 1/2 or more, air resistance is left particularly at the time of degassing at the time of roll pre-pressing because the resistance to movement of air at the time of pre-pressing is large. Also,
Since the protruding portion is hard to be crushed, poor sealing is caused, and defects such as foaming or baking foaming occur after the final pressure bonding. Furthermore,
The slip resistance between the glass and the film is too small, and the glass plate is easily displaced in the pre-pressing process of laminated glass processing.
Poor workability.

In the second aspect of the present invention, the value of P / S is preferably 2.2 or more and 7.0 or less.

In the first or second aspect of the present invention, the form and roughness of the main emboss are not particularly limited. For example, as the shape of the protruding portion, a cone such as a cone or a pyramid, a pseudo cone, a prism such as a prism, a cylinder, or the like can be used. The roughness of the main emboss is generally 10 to 7
It can be used in the range of 0 μm. Further, the arrangement of the protrusions may be random or regular, and if the average interval (pitch) and the average bottom area of the protrusions do not vary greatly and the surface shape of the intermediate film satisfies the above-mentioned relational expressions, excellent degassing properties are obtained. Can be demonstrated.

If the sub-embossing is not performed, the self-adhesive force between the films and the glass-film sliding resistance increase, which greatly impairs the workability in processing the laminated glass. Further, by providing the sub-emboss, a remarkable effect is also exerted on prevention of leading edge seal during pre-pressing. The shape of the sub-emboss is not particularly limited as long as the average roughness is equal to or less than half of the average roughness of the main emboss. In particular, regarding the intermediate film according to the second aspect, S ′, P ′,
Each value of R ′ may be such that the average value satisfies the above-mentioned relational expressions, and there is no problem even if the values vary.

The heat shrinkage of the intermediate film is not particularly limited, and the effect can be recognized as long as the surface emboss shape satisfies the above-described embossing condition. That is, the intermediate film shrinks in the heating furnace during the pre-press for the laminating process, resulting in poor appearance, deformation of the glass due to significant shrinkage of the intermediate film, transformation into laminated glass, and / or shrinkage accompanying shrinkage of the intermediate film. It is sufficient that the pre-sealing due to partial thickening of the intermediate film inside the glass does not occur, and for example, an intermediate film having a heat shrinkage of 5% or less at 50 ° C. and 1 hr. Can be used.

The interlayer film for laminated glass in the present invention comprises:
[Glass / interlayer / glass], [glass / interlayer / glass / interlayer / thermoplastic layer], [glass / interlayer / thermoplastic layer], [thermoplastic layer / interlayer / glass /
Intermediate film / thermoplastic resin layer] or the like, but is not particularly limited thereto.

Examples of the thermoplastic resin include polyvinyl butyral, polyurethane, polyvinyl chloride-ethylene copolymer, vinyl chloride-ethylene-glycidyl methacrylate copolymer, vinyl chloride-ethylene-glycidyl acrylate copolymer, and vinyl chloride. -Glycidyl methacrylate copolymer, vinyl chloride-glycidyl acrylate copolymer, polyvinylidene chloride, polyvinylidene chloride-acrylonitrile copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl acetal-
Polyvinyl butyral mixtures and the like can be mentioned.

Of these, polyvinyl butyral, polyurethane and vinyl chloride-ethylene-glycidyl methacrylate copolymer are particularly preferably used.

Next, the plasticizer to be kneaded into such a vinyl resin composition is not particularly limited, but includes, for example, dioctyl phthalate, dibutyl phthalate, adipic acid-di-2-ethylhexyl, adipic acid Examples thereof include diisododecyl, epoxy fatty acid monoester, triethylene glycol-di-2-ethylbutyrate, triethylene glycol-di-2-ethylhexoate, dibutyl sebacate, and dibutyl sebacate. The amount of the plasticizer is 20 to the vinyl resin.
The range of ~ 45% by weight is preferred.

As a method of forming the above-mentioned thermoplastic resin composition into an interlayer film for laminated glass, any known method can be adopted as long as the above-mentioned embossing conditions are satisfied. For example, it can be formed by a calender roll method, an extrusion method, a casting method, an inflation method, or the like. The embossed shape on the surface of the intermediate film may be provided by a method such as embossing on a lip surface or a molding die such as an embossing roll or a die roll, but is not particularly limited. In forming the sheet, a heat stabilizer, an antioxidant and the like may be added to the sheet as required.
Further, in order to give high penetration resistance, an adhesive force adjuster, for example, a metal salt may be blended.

[0030]

By providing an embossment that satisfies the above-mentioned embossing condition on at least one side of the intermediate film, the air interposed between the glass plate and the intermediate film can be smoothly exhausted and sufficiently degassed during the pre-compression bonding. And no prior sealing occurs, and excellent adhesion (sealability) of the glass-interlayer film is obtained. As a result, even if the linear speed in the assembling process is significantly increased, there is no lack of deaeration. In addition, it demonstrates excellent degassing even when manufacturing difficult-shaped laminated glass with a large glass pair difference, and efficiently manufactures laminated glass that is completely transparent even after final compression bonding and does not cause problems such as bake foaming. Becomes possible.

[0031]

Next, an embodiment of the present invention will be described. An intermediate film was prepared by setting the emboss pitch, the shape of the protrusion, the bottom area of the protrusion, and the roughness under various conditions, and the blocking property was examined. Observation of the surface emboss shape, the pitch of the main emboss (average distance between the peaks of the protrusions) P (= [observation area / number of protrusions] ^1/2 ) and the bottom area of the protrusions of the main emboss are determined by stereoscopic microscope observation. Measured.

The roughness was measured with a non-contact laser type measuring machine (manufactured by Pelten) and a surface shape analyzer (Meishin Koki). Furthermore, the blocking property is that the interlayer film is 10
It is cut into a size of 0 mm x 25 mm, two of them are stacked, a load of 2 kg is placed thereon, and after standing for 24 hours, a 180 ° peeling force (n = 5) is obtained by a tensile test.
Was measured and evaluated. The larger the value, the higher the adhesive strength, indicating that the workability is poor.

First, Examples 1 and 2 corresponding to the invention described in claim 1 were compared with Comparative Examples 1 to 3.
A description will be given in comparison with Comparative Example 3.

Example 1 An emboss was formed on both surfaces of a plasticized polyvinyl butyral sheet using an emboss roll to produce an intermediate film. A main emboss and a random sub-emboss having a surface emboss shape satisfying the above-described emboss condition of the present invention (the condition according to claim 1) are applied. Table 1 shows the embossed shape and the like.

Example 2 The surface embossed shape satisfying the above-mentioned embossing condition of the present invention (the condition described in claim 1), and as shown in Table 1, Example 1 An intermediate film was produced under the same conditions as in Example 1 except that the numerical values differ from the above.

Comparative Example 1 An intermediate film was produced under the same conditions as in Example 1 except that the embossing was completely random embossing and the embossing shape and numerical values were different as shown in Table 1.

[Comparative Example 2] As shown in Table 1, an intermediate film was produced under the same conditions as in Example 1 except that the embossed shapes and numerical values were different, and no sub-emboss was applied.

Comparative Example 3 As shown in Table 1, an intermediate film was produced under the same conditions as in Example 2 except that no sub-emboss was applied.

Next, laminated glasses were produced by the following methods (a) and (b) using the intermediate films obtained in the above Examples and Comparative Examples.

(A) Pre-compression bonding by roll method and final compression bonding An intermediate film is inserted between two glass sheets, and the protruding portion is cut out. This laminate was heated at 50 ° C.
Heat to 60 ° C, 70 ° C, 80 ° C, 90 ° C, and 100 ° C and pass through a nip roll at a linear speed of 10 m / min.
Pre-compression bonding was performed by a roll method. The laminated body after the pre-compression bonding was held in an autoclave under the conditions of a pressure of 14 kg / cm ² and a temperature of 140 ° C. for 10 minutes, and then the temperature was reduced to 50 ° C. and the pressure was released to complete the actual bonding.

(B) Pre-compression bonding by pressure reduction method and final compression bonding The intermediate film is inserted between two glass sheets, and the protruding portion is cut out. This laminate is put into a rubber bag, the inside of the rubber bag is connected to a reduced pressure system, and the temperature is 60 ° C., 80 ° C., 100 ° C.
And -600 mmH for 10 minutes at 120 ° C. outside air heating temperature
g, and the pressure was returned to the external pressure to complete the preliminary pressure bonding. The final pressure bonding was performed by the same method as in the above (a).

[0042]

[Table 1]

The obtained laminated glass was heated to check for the occurrence of bubbles. That is, ten laminated glasses each using the same kind of interlayer film were placed in an oven at 135
After heating at 2 ° C. for 2 hours and gradually cooling to room temperature, the number of samples having bubbles in the laminated glass was examined. The results are shown in Table 2 for the laminated glass manufactured by the roll method.
Table 3 shows laminated glass produced by the vacuum method.
Respectively.

[0044]

[Table 2]

[0045]

[Table 3]

Next, Examples 3 and 4 corresponding to the invention described in claim 2 will be described in comparison with Comparative Examples 4 and 5.

Example 3 An emboss was formed on both surfaces of a plasticized polyvinyl butyral sheet using an emboss roll to produce an intermediate film. A main emboss and a random sub-emboss having a surface emboss shape satisfying the above-described emboss condition of the present invention (the condition described in claim 2 of the claims) are applied. Table 4 shows the embossed shape and the like.

[Embodiment 4] A surface embossed shape satisfying the above-mentioned embossing condition of the present invention (the condition described in claim 2 of the present invention), and as shown in Table 4, Embodiment 3 An intermediate film was produced under the same conditions as in Example 3 except that the numerical values were different.

Comparative Example 4 As shown in Table 4, an intermediate film was produced under the same conditions as in Example 3 except that the values of the sub-emboss were different.

Comparative Example 5 As shown in Table 4, an intermediate film was produced under the same conditions as in Example 4 except that the numerical value of the sub-emboss was different.

Next, using the intermediate films obtained in the above Examples and Comparative Examples, laminated glasses were produced by the following methods (c) and (d).

(C) Pre-compression bonding by roll method and final compression bonding An intermediate film is inserted between two glass sheets, and the protruding portion is cut out. This laminate was heated at 50 ° C.
Heat to each temperature of 90 ° C and 100 ° C, linear velocity 15m / m
The sheet was passed through a nip roll at a linear pressure of 2.5 kg / cm and pre-compressed by a roll method. The laminated body after the pre-compression bonding was held in an autoclave under the conditions of a pressure of 14 kg / cm ² and a temperature of 140 ° C. for 10 minutes, and then the temperature was reduced to 50 ° C. and the pressure was released to complete the actual bonding.

(D) Pre-compression bonding by pressure reduction method and final compression bonding The intermediate film is inserted between two glass sheets, and the protruding portion is cut out. This laminate was placed in a rubber bag, and the inside of the rubber bag was connected to a reduced pressure system.
It was kept at a heating temperature of 0 ° C. in the outside air for 10 minutes under a reduced pressure of −600 mmHg, returned to the outside air pressure, and completed the pre-compression bonding. The final pressure bonding was performed by the same method as in the above (c).

[0054]

[Table 4]

The obtained laminated glass was heated to check whether bubbles were generated. That is, ten laminated glasses each using the same kind of interlayer film were placed in an oven at 135
After heating at 2 ° C. for 2 hours and gradually cooling to room temperature, the number of samples having bubbles in the laminated glass was examined.

The results are shown in Table 5 for laminated glass produced by the roll method, and in Table 6 for laminated glass produced by the reduced pressure method.

[0057]

[Table 5]

[0058]

[Table 6]

[0059]

As is apparent from the above description, according to the interlayer film for a laminated glass of the present invention, when manufacturing a difficult-shaped laminated glass having a large difference between glass pairs or in a laminating step in order to improve productivity. Even when the speed is increased, it is possible to provide a laminated glass excellent in deaeration and excellent in transparency, which balances the ease of air escape and the ease of emboss collapse. In the pre-compression bonding step, degassing can be performed in a wide temperature range and in a short time,
Workability is also improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a laminated glass using a conventional interlayer film for laminated glass.

[Description of Signs] 1 sheet 2 protrusion 3 recess 4 glass plate 5 interlayer

Claims (2)

(57) [Claims] 1. An interlayer film for a laminated glass comprising a thermoplastic resin sheet or film having a large number of fine irregularities (embosses) on at least one side, wherein the emboss comprises a main emboss and a sub-emboss. The area S of the bottom of the protruding portion constituting [× 10 ^-8 cm]
² ] and the average interval (apparent pitch) P [μ
m] and 1.5 ≦ P / S × 100 ≦ 5.5, and the average roughness of the sub-emboss is not more than の of the average roughness of the main emboss. Interlayer for laminated glass. 2. An interlayer film for laminated glass comprising a thermoplastic resin sheet or film having a large number of fine irregularities (embosses) on at least one side, wherein the emboss comprises a coarse main emboss and a fine sub-emboss. ,
The area S [× 10 ^-8 ] of the bottom of the protrusion of the main emboss
cm ² ], average spacing (apparent pitch) P of the protrusions
[Μm], average roughness R, area S ′ [× 10 ⁻⁸ cm ² ] of the bottom of the protrusion of the sub-emboss, average distance (apparent pitch) P ′ [μm] of the protrusion, average roughness R ′ satisfies the following relations (1) to (3): an interlayer film for laminated glass. 1/180 <S '/ S <1/2 (1) 1/11 <P' / P <2/5 (2) 1/6 <R '/ R <1/2 (3)