JPH06198809A - Intermediate film for safety glass - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] Providing an interlayer film that can produce laminated glass with good degassing properties and good transparency, with a balance of ease of air escape and crushing of embossing. . [Structure] In an interlayer film for laminated glass, which is made of a thermoplastic resin sheet or film having a large number of fine irregularities (embossing) on one surface, the embossing consists of main embossing and sub-embossing, and the protruding portion that constitutes the main embossing. The area S [× 10 ⁻⁸ cm ² ] of the bottom of the and the average interval (apparent pitch) P [μm] of the protrusions is 1.5 ≦ P / S × 10
The average roughness of the sub-emboss is 1/2 or less of the average roughness of the main emboss. Also,
The area S of the bottom of the protrusion of the main emboss, the apparent pitch P, and the average roughness R, and the area S'of the bottom of the protrusion of the sub-emboss, the apparent pitch P ', and the average roughness R'have a specific relationship. Be satisfied.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an interlayer film for laminated glass. More specifically, the present invention relates to an interlayer film which is inserted between two glass plates to form a laminated glass, and particularly has good workability during the laminating process, sealing property with glass, and comprehensive degassing property such as seal leading prevention. The present invention relates to an interlayer film for laminated glass.

[0002]

2. Description of the Related Art Laminated glass is a laminated glass composed of a laminated body in which an intermediate film is inserted between two plate glasses, and has an excellent feature that it has high strength and is not easily broken. It is a safe glass material that does not scatter. Therefore, it is widely used as window glass for transportation equipment such as automobiles and airplanes, and for buildings.

When manufacturing this laminated glass, an interlayer film made of an adhesive thermoplastic resin is inserted between two glass plates, and the obtained laminate is pre-pressed to eliminate air remaining between the layers. After (degassing), the main body is press-bonded to completely adhere the laminate.

The intermediate film used for the laminated glass is
It is required that the interlayer films do not block each other during storage, the workability when stacking the glass and the interlayer film is good, and that the degassing property in the preliminary pressure bonding step is good. . In particular, degassing during pre-pressing affects the quality of the laminated glass, and if degassing is inadequate, the resulting laminated glass may have poor transparency, or bubbles may form when an accelerated test is performed. is there.

The overall performance of the interlayer film including the above-described deaeration depends on the type of the thermoplastic resin as the raw material and the physical properties such as viscoelasticity. If these physical properties are fixed and considered, the interlayer film The surface shape of the is a major factor in determining its overall performance.

Particularly, it is known that it is effective to form a large number of fine irregularities called embosses on the surface of the intermediate film, and the intermediate film having the embossed surface is conventionally used. Examples of the form of the emboss include, for example, one in which unevenness having a random size and shape is formed, and one in which a large number of grid-like grooves are formed.

The conventional interlayer film having such an embossed surface is effective in terms of preventing blocking between the films and improving workability when laminating the glass plate and the interlayer film. In addition, a certain degree of effect can be recognized regarding the deaeration property in the preliminary pressure bonding step. However, in recent years, conventional interlayer films have been used because of an increase in the glass pair difference due to an increase in demand for difficult-to-shape laminated glass such as a three-dimensional curved surface having a large radius of curvature and an increase in the linear speed of the laminating process accompanying the improvement in productivity. Degassing is not always satisfactory. Therefore, due to insufficient degassing properties, air bubbles may remain between the glass plate and the intermediate film, or because the adhesiveness (sealing property) is insufficient, a completely transparent laminated glass may not be obtained, It had a defect that foaming occurred after the accelerated test.

Regarding the improvement of the degassing property of such an interlayer film for laminated glass, the following prior arts have been proposed so far. For example, Japanese Patent Publication No. 1-32776 discloses that
As shown in FIG. 1, a laminated glass is disclosed in which an intermediate film 5 having a large number of independent projections 2 formed on a surface of a sheet 1 and a glass plate 4 are laminated. In the interlayer film 5 of this laminated glass, the bottoms of the recesses 3 formed between the adjacent protrusions 2 are all at the same level, and the recesses 3 are continuous with each other. The invention described in the above publication is
By adopting such a configuration, the blocking prevention property between the interlayer films and the workability in stacking the glass plate and the interlayer film are improved. The shape of the protrusion 2 is a cone or a pseudo cone.

Further, Japanese Patent Publication No. 54-21209 (US Pat. No. 578710) also discloses an intermediate film in which a large number of independent projections are formed on the surface of a sheet. In this intermediate film, unevenness is formed so that the depth of the recess formed between the protrusions falls within a predetermined range.

[0010]

However, the conventional interlayer film as described above is still insufficient in deaerating property in the pre-compression bonding step. In particular, in the interlayer film described in Japanese Patent Publication No. 54-21209, the depths of the recesses formed on the surface of the sheet are almost the same, which is excellent in deaeration during the production of laminated glass. It cannot be said that. This seems to be a result that no consideration has been given to the shape of the uneven portion formed on the surface of the intermediate film.

Further, the conventional intermediate film as described above does not have an appropriate degree of crushing of the emboss, which causes foaming or the like after the main pressure bonding step. That is, the step of pre-compressing the glass plate and the intermediate film tends to be performed at a considerably high speed in recent years, and particularly when degassing by a nip roll, the projections formed on the sheet surface smoothly discharge air. It has to be something that makes it happen. Therefore, in order to secure the adhesiveness (sealing property) with the glass, the embossment is a surface that is easily crushed at the pressure (about 5 to 10 kg / cm ² ) and the temperature (about 50 to 100 ° C.) during the preliminary pressing. It is required to have a shape.

However, the embossing is apt to be crushed,
If it is crushed before reaching the preliminary press conditions, it will be in a peripherally-unbalanced adhesive state called seal leading, and an air trapped state will occur, resulting in seal breakage due to the accumulated air, such as foaming after the main pressure bonding step. Defect occurs.

Further, even when deaeration is performed by a vacuum preliminary press by depressurizing the inside of the rubber bag, the deaeration resistance is reduced and the crushing balance of the embossing is balanced in order to avoid foaming due to the peripheral seal leading. Need to take.

Therefore, the present invention provides an interlayer film for laminated glass, which can balance the ease of air escape and the crushing of embossing, is excellent in deaeration, and can produce laminated glass having good transparency. The purpose is to

[0015]

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, a laminated glass in which a large number of fine protrusions (embosses) are provided on at least one surface of a film or sheet made of a thermoplastic resin. In the intermediate film for use in glass, the above object was achieved by improving the shape of the emboss, and an intermediate film for laminated glass excellent in comprehensive degassing could be 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 embossing is composed of a main embossing and a sub-embossing, and the main embossing has a relatively uniform shape, and the area S [× 10 ^-8 cm ² ] of the bottom of the protruding portion and the average spacing P between the protruding portions.
[Μm] satisfies the relationship of 1.5 ≦ P / S × 100 ≦ 5.5, and the average roughness of the sub-emboss is half or less of the main emboss.

Here, when the value of P / S × 100 is smaller than 1.5, the resistance against the movement of air during the prepress becomes large, so that the residual air remains especially during deaeration during the roll prepress. Occurs. In addition, under these conditions, the protrusions are less likely to be crushed, resulting in poor sealing, resulting in problems such as foaming and bake foaming after main pressure bonding. On the other hand, P / S x 100
When the value of is larger than 5.5, the glass and the interlayer film adhere to each other before the internal air is exhausted in the peripheral portion of the glass (edge seal precedent), and bubbles remain after the main pressure bonding. The value of P / S × 100 is preferably 2.5 to 4.
The range is 5.

Further, claim 2 of the present invention
In the intermediate film for laminated glass comprising a thermoplastic resin sheet or film having a large number of fine irregularities (emboss) on at least one surface, the emboss is composed of a coarse main emboss and a fine sub-emboss. And the area S [x of the bottom of the protrusion of the main embossing]
10 ⁻⁸ cm ² ], average spacing (apparent pitch) P [μm] of the protrusions, average roughness R, and area S ′ [× 10 ⁻⁸ cm ² ] of the bottom of the protrusion of the sub-emboss, The average pitch (apparent pitch) P ′ [μm] of the protrusions and the average roughness R ′ 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)

The value of S '/ S is 1/180 or less, P' / P
When the value of is 2/5 or more or the value of R '/ R is 1/6 or less, the glass and the interlayer film adhere to each other around the glass (edge seal precedent) before the internal air is exhausted. Bubbles remain even after arrival and departure. Further, the self-adhesive force between the interlayer films and the sliding resistance between the glass and the interlayer film are increased, which causes a great hindrance to workability during processing of the laminated glass.

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, resistance to air movement during prepress is large, and air remains especially during deaeration during roll prepress. Also,
Since the protruding portion is less likely to be crushed, a sealing failure occurs, and foaming or bake foaming occurs after the main pressure bonding. Furthermore,
The slip resistance between the glass and the film becomes too small, and the glass plate easily shifts in the preliminary pressing process for processing laminated glass,
Workability is poor.

Also in the invention described in claim 2, the value of P / S is preferably not less than 2.2 and not more than 7.0.

In the invention described in claim 1 or 2, the shape and roughness of the main emboss are not particularly limited. For example, as the shape of the protrusion, a cone such as a cone or a pyramid, a pseudo-cone, a prism such as a prism, or a cylinder can be used. In addition, the roughness of the main emboss is generally 10-7.
It can be used in the range of 0 μm. Furthermore, the arrangement of the protrusions may be random or regular arrangement, and if the average spacing (pitch) and the average bottom surface of the protrusions do not vary greatly and the interlayer surface shape that satisfies each of the above relational expressions, excellent degassing property is obtained. Can be demonstrated.

When sub-embossing is not applied, the self-adhesive force between the films and the glass-film slip resistance increase, which causes a great hindrance to workability during the processing of laminated glass. Further, by providing this sub-embossing, a remarkable effect can be exhibited also in the edge seal leading prevention at the time of preliminary pressing. Regarding the sub-embossing, the shape is not particularly limited as long as the average roughness is half or less of the average roughness of the main embossing, and even if there are variations, the effect is sufficiently exhibited. Further, particularly regarding the intermediate film corresponding to claim 2, S ′, P ′,
It suffices for each value of R ′ to have an average value satisfying each of the above-mentioned relational expressions, and there is no problem even if they vary.

The heat shrinkage rate of the intermediate film is not particularly limited, and the effect can be recognized as long as the surface embossed shape satisfies the embossing conditions described above. In other words, the interlayer film shrinks in the heating furnace during the pre-press for laminating process, resulting in poor appearance, and the deformation of the glass due to the large shrinkage of the interlayer film, the transformation into laminated glass and / or the contraction of the interlayer film. It suffices that the sealing does not occur before the sealing due to the partial thickening of the intermediate film inside the glass. For example, an intermediate film having a heat shrinkage ratio of 5% or less at 50 ° C. and 1 Hr may be used. Can be used.

The interlayer film for laminated glass in the present invention is
[Glass / interlayer film / glass], [glass / interlayer film / glass / intermediate film / thermoplastic resin layer], [glass / intermediate film / thermoplastic resin layer], [thermoplastic resin layer / intermediate film / glass /
The interlayer film / thermoplastic resin layer] and the like are used for the laminate, but the combination 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, vinyl chloride. -Glycidyl methacrylate copolymer, vinyl chloride-glycidyl acrylate copolymer, polyvinylidene chloride, polyvinylidene chloride-acrylonitrile copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl acetal-
A polyvinyl butyral mixture etc. can be mentioned.

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

Next, the plasticizer to be kneaded with such a vinyl resin composition is not particularly limited, but 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 blending amount of the plasticizer is 20 with respect to the vinyl resin.
A range of up to 45% by weight is preferred.

As a method of forming the interlayer film for laminated glass from the above thermoplastic resin composition, any known method can be adopted as long as the above-mentioned embossing conditions are satisfied. For example, it can be formed by a calendar roll method, an extrusion method, a casting method, an inflation method, or the like. The embossed shape may be imparted to the surface of the intermediate film by using a molding die such as an embossing roll or a die roll, or embossing on the lip surface, but the embossing shape is not particularly limited. Further, at the time of forming the sheet, a heat stabilizer, an antioxidant and the like may be added to the sheet, if necessary.
Further, in order to provide high penetration resistance, an adhesive force adjusting agent, for example, a metal salt may be added.

[0030]

By applying embossing that satisfies the above-mentioned embossing conditions to at least one side of the intermediate film, the air existing between the glass plate and the intermediate film can be smoothly discharged and fully degassed during pre-press bonding. It is possible to obtain a glass-intermediate film having excellent adhesiveness (sealability) without the need for sealing. As a result, degassing does not become insufficient even if the linear velocity in the alignment process is increased significantly. Further, it is possible to efficiently produce a laminated glass that exhibits excellent deaeration even when manufacturing a difficult-to-shape laminated glass with a large difference in glass pair, is completely transparent even after main pressure bonding, and does not cause defects such as bake foaming. Is possible.

[0031]

EXAMPLES Next, examples of the present invention will be described. The embossing pitch, the shape of the protrusions, the bottom area of the protrusions, and the roughness were set under various conditions to prepare an intermediate film, and the blocking property was examined. Observation of the surface embossed shape, main emboss pitch (average distance between peaks of protrusions) P (= [observation area / number of protrusions] ^1/2 ) and bottom area of protrusions of main embossing were observed by a stereoscopic microscope. Actually measured.

The roughness was measured by a non-contact laser type measuring machine (manufactured by Pelten Co.) and a surface shape analyzer (Meishing Machine). Furthermore, the blocking property is 10
Cut into a size of 0 mm × 25 mm, stack two sheets, put a load of 2 kg on it, leave it for 24 hours, and then pull it for 180 ° peeling force (n = 5)
Was measured and evaluated. The larger the value, the larger the adhesive force and the poorer the workability.

First of all, Comparative Examples 1 to 2 are used for Example 1 and Example 2 corresponding to the invention described in claim 1 of the claims.
This will be described in comparison with Comparative Example 3.

[Example 1] Embossing was performed using embossing rolls on both surfaces of a plasticized polyvinyl butyral sheet to prepare an interlayer film. The main embossing and the random sub-embossing are formed so as to satisfy the above-mentioned embossing conditions of the present invention (the conditions described in claim 1 of the claims). Table 1 shows the embossed shape and the like.

[Embodiment 2] A surface embossed shape satisfying the above-mentioned embossing conditions of the present invention (conditions described in claim 1 of the appended claims), and as shown in Table 1, Example 1 was used. An intermediate film was produced under the same conditions as in Example 1 except that the numerical values were different from.

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

[Comparative Example 2] An interlayer film was produced under the same conditions as in Example 1 except that the emboss shape and numerical values were different as shown in Table 1 and sub-embossing was not performed.

[Comparative Example 3] As shown in Table 1, an interlayer film was produced under the same conditions as in Example 2 except that sub-embossing was not performed.

Next, using the interlayer films obtained in each of the above Examples and Comparative Examples, laminated glass was prepared by the following methods (a) and (b).

(A) Pre-pressing and main-pressing by roll method The intermediate film is inserted between two plate glasses, and the protruding portion is cut off. This laminated body is heated in a hot oven at 50 ° C.
Heated to each temperature of 60 ° C, 70 ° C, 80 ° C, 90 ° C and 100 ° C, and passed through a nip roll at a linear velocity of 10 m / min,
Pre-bonding was performed by the roll method. The pre-press-bonded laminate 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 lowered to 50 ° C. and the pressure was released to complete the main adhesion.

(B) Pre-compression bonding and main compression bonding by decompression method The interlayer film is inserted between two plate glasses, and the protruding portion is cut off. This laminated body is put in a rubber bag, and the inside of the rubber bag is connected to a decompression system, and the temperature is 60 ° C, 80 ° C, 100 ° C.
And -600 mmH for 10 minutes at 120 ° C outside air heating temperature
The pressure was maintained under a reduced pressure of g, and the pressure was returned to the atmospheric pressure to complete the preliminary pressure bonding. The main pressure bonding was performed by the same method as the above (a).

[0042]

[Table 1]

The obtained laminated glass was heated to examine whether bubbles were generated. That is, 10 laminated glasses each using the same type of interlayer film are placed in an oven for 135
After heating at 0 ° C. for 2 hours and gradually cooling to room temperature, the number of samples in which bubbles were generated in the laminated glass was examined. The results are shown in Table 2 for the laminated glass produced by the roll method,
Table 3 shows the laminated glass produced by the reduced pressure method.
Respectively shown.

[0044]

[Table 2]

[0045]

[Table 3]

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

Example 3 Embossing was performed using embossing rolls on both surfaces of a plasticized polyvinyl butyral sheet to prepare an interlayer film. The main embossing and the random sub-embossing having a surface embossing shape satisfying the above-described embossing conditions of the present invention (conditions described in claim 2 of the claims) are provided. Table 4 shows embossed shapes and the like.

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

[Comparative Example 4] An interlayer film was produced under the same conditions as in Example 3 except that the values of sub-embossing were different as shown in Table 4.

[Comparative Example 5] As shown in Table 4, an interlayer film was produced under the same conditions as in Example 4 except that the values of sub-embossing were different.

Next, using the interlayer films obtained in each of the above Examples and Comparative Examples, laminated glass was prepared by the following methods (c) and (d).

(C) Pre-pressing and main-pressing by roll method The interlayer film is inserted between two plate glasses, and the protruding portion is cut off. This laminated body is heated in a hot oven at 50 ° C.
Heated at each temperature of 90 ℃ and 100 ℃, linear velocity 15m / m
In, a linear pressure of 2.5 kg / cm was passed through a nip roll, and pre-compression bonding was performed by a roll method. The pre-press-bonded laminate 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, then the temperature was lowered to 50 ° C. and the pressure was released to complete the main adhesion.

(D) Pre-compression bonding and main compression bonding by decompression method The intermediate film is inserted between two plate glasses, and the protruding portion is cut off. This laminated body was put in a rubber bag, and the inside of the rubber bag was connected to a decompression system, and the temperature was 60 ° C, 100 ° C and 12 ° C.
It was kept under reduced pressure of -600 mmHg for 10 minutes at the outside air heating temperature of 0 ° C., and returned to the outside air pressure to complete the preliminary pressure bonding. The main pressure bonding was performed by the same method as the above (c).

[0054]

[Table 4]

The obtained laminated glass was heated to examine whether bubbles were generated. That is, 10 laminated glasses each using the same type of interlayer film are placed in an oven for 135
After heating at 0 ° C. for 2 hours and gradually cooling to room temperature, the number of samples in which bubbles were generated in the laminated glass was examined.

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

[0057]

[Table 5]

[0058]

[Table 6]

[0059]

As is clear from the above description, according to the interlayer film for laminated glass of the present invention, the line in the laminating step is used for producing a difficult-shaped laminated glass having a large difference in glass pair and for improving productivity. Even when the speed is increased, it is possible to provide a laminated glass having a good balance of air easiness and crushing of embossing, excellent degassing property, and good transparency. Also, in the pre-bonding process, deaeration in a wide temperature range and in a short time becomes possible,
Workability is also improved.

[Brief description of drawings]

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

[Explanation of reference numerals] 1 sheet 2 protrusions 3 recesses 4 glass plate 5 intermediate film

Claims (2)

[Claims] 1. An intermediate film for laminated glass, which comprises a thermoplastic resin sheet or film having a large number of fine irregularities (embossing) on at least one surface, wherein the emboss comprises a main emboss and a sub emboss. Area S of the bottom of the protruding portion that constitutes the S [× 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 1/2 or less of the average roughness of the main emboss. Intermediate film for laminated glass. 2. An intermediate 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 fine sub-embosses. ,
The area S of the bottom of the protruding portion of the main emboss S [× 10 ⁻⁸
cm ² ], the average spacing (apparent pitch) P of the protrusions
[Μm], average roughness R, area S ′ [× 10 ⁻⁸ cm ² ] of the bottom side of the protrusion of the sub-emboss, average spacing (apparent pitch) P ′ [μm] of the protrusions, average roughness An interlayer film for laminated glass, characterized in that R'and the following relations (1) to (3) are satisfied. 1/180 <S '/ S <1/2 (1) 1/11 <P' / P <2/5 (2) 1/6 <R '/ R <1/2 (3)