JPH10109379A - Glass laminate and fluororesin sheet for laminating glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the transparency and achieve the strong adhesion by bonding glass to a fluororesin sheet with the held of an adhesive containing the specific weight ratio of a fluororesin component and an acrylic resin component. SOLUTION: An adhesive for bonding a fluororesin sheet to glass consists of 40-80wt.% of fluororesin component and 60-20wt.% of acrylic resin component. The fluororesin component is preferably of such a type that contains 50-100wt.% of vinylidene fluoride, 0-40wt.% of tetrafluoroethylene and 0-30wt.% of hexafluoropropylene. On the other hand, as a monomer of the acrylic resin component, methylmethacrylate is an essential component and therefore, it is necessary that methylmethacrylate be contained at a ratio of 90wt.% or more to the total content of the acrylic resin component. Further, to improve the adhesion of the fluororesin sheet with glass, it is preferable to add acid monomers such as acrylic acid, methacrylic acid, fumaric acid and itaconic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate of glass and a fluororesin sheet, and a fluororesin sheet having adhesiveness to glass for obtaining the laminate.

[0002]

2. Description of the Related Art A glass plate is a material having transparency and strength, but has low impact resistance, and as a method for compensating for this, safety glass bonded to a plastic sheet is generally used. However, general plastic sheets can prevent the fragments from being scattered when the glass breaks, but cannot satisfy the flame retardancy because the plastic sheets burn in a fire. Therefore,
As a glass that has fire and flame resistance and has a property of preventing fragments from being scattered even when it is normally broken, fire prevention safety glass in which a fluororesin sheet is adhered to a glass plate has been proposed.

[0003] However, since the fluororesin sheet has poor adhesion to other materials such as glass, it is necessary to use an adhesive in order to achieve strong adhesion, but this impairs the high transparency of glass. It was difficult to achieve a strong bond without using the same.

Conventionally, polyvinyl butyral, ethylene-vinyl acetate copolymer, and the like have been used as an intermediate film for producing a laminated glass, and these materials are applied to bonding between a fluororesin sheet and glass. However, it is not possible to achieve strong adhesion with good transparency.

[0005]

SUMMARY OF THE INVENTION The present invention is to provide a laminate in which glass and a fluororesin sheet are firmly adhered to each other and high transparency is maintained. Another object is to provide a bonding fluororesin sheet for obtaining such a laminate.

That is, the gist of the present invention is that a glass and a fluororesin sheet are mixed with 40 to 80% by weight of a fluororesin component.
A glass laminate characterized by being bonded by an adhesive containing 60 to 20% by weight of an acrylic resin component.

Another gist of the present invention is that at least one side of a fluororesin sheet contains 40 to 80% by weight of a fluororesin component.
And an adhesive coating containing 60 to 20% by weight of an acrylic resin component.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The fluororesin sheet in the present invention has a monomer component,
Vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, pentafluoropropylene, a homopolymer or copolymer of a fluorinated monomer such as hexafluoropropylene, or the fluorinated monomer, ethylene, It comprises a copolymer in which a vinyl monomer such as an alkyl vinyl ether is used in combination, or a mixture thereof. Any material that can be formed into a sheet, that is, a material that can be hot melt-molded, may be used.
Fluororesins other than E) can be used without particular limitation.

Specifically, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-vinylidene fluoride-hexafluoro Propylene copolymer, polyvinylidene fluoride,
And polyvinyl fluoride.

[0010] Then, when trying to obtain fireproof glass,
In order to ensure flame retardancy, it is preferable to select a fluorine content of 55% by weight or more, preferably 60% by weight or more.

The fluororesin sheet preferably contains vinylidene fluoride as a component for the reasons described below. Particularly preferred fluororesin sheets include terpolymers of vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene. The preferred copolymerization ratio of the terpolymer is 20% vinylidene fluoride.
-40 weight%, tetrafluoroethylene 20-60 weight%, hexafluoropropylene 5-20 weight%.

The copolymer sheet has low crystallinity and good transparency, is flexible and excellent in impact resistance, and has a relatively low melting point, so that it is suitable for heat fusion with glass.

The thickness of the fluororesin sheet is not particularly limited, but is preferably in the range of 50 to 2000 μm in consideration of the impact on the impact resistance when laminated with glass. The molding of the fluororesin sheet may be performed by a generally known method.For example, a fluororesin is dissolved in an organic solvent, applied uniformly on a peelable substrate, and then dried to remove the organic solvent. A method of peeling from a material to form a sheet, a method of drying water after uniformly applying an aqueous dispersion of a fluororesin on a peelable substrate, or a method of extrusion, a thermoplastic method such as a calendar method or the like. A method of forming a sheet is possible.

Various additives can be added to the fluororesin sheet within a range that does not impair the properties of the fluororesin sheet, especially transparency.

An adhesive film for bonding the fluororesin sheet to glass is provided on at least one side, preferably both sides, of the fluororesin sheet. Further, it may be formed on a glass surface.

The adhesive for forming the adhesive film is 40 to 80% by weight, preferably 50 to 70% by weight, of the fluororesin component.
And an acrylic resin component of 60 to 20% by weight, preferably 5
0 to 30% by weight. If the fluororesin component is less than 40% by weight, the adhesion to the fluororesin sheet is impaired, and if the fluororesin component exceeds 80% by weight (the acrylic resin component is less than 20% by weight), the adhesion to glass is impaired. .

The form of the two components is a block copolymer having a block of a fluorine-containing monomer and a block of a (meth) acrylate, or a graft copolymer in which one resin is grafted with the other resin component. May be
Practically, a blend of a fluororesin and an acrylic resin is preferable from the viewpoint of the production efficiency and cost of the resin.

As the fluororesin component, a monomer component mainly composed of vinylidene fluoride is used.
Specifically, those containing 50 to 100% by weight of vinylidene fluoride, 0 to 40% by weight of tetrafluoroethylene and 0 to 30% by weight of hexafluoropropylene are preferable.

On the other hand, monomers of the acrylic resin component include (meth) acrylic acid methyl, ethyl, propyl,
Examples include esters such as butyl, isobutyl, n-hexyl, 2-ethylhexyl, lauryl, and stearyl, but methyl methacrylate is an essential component and must be contained in a proportion of 90% by weight or more in the acrylic resin component. . If the amount is less than 90% by weight, the adhesion to glass becomes insufficient when the glass is adhered.

As other alkyl (meth) acrylate monomers, methyl acrylate, butyl acrylate, butyl methacrylate, isobutyl methacrylate and the like can be preferably used.

Further, it is preferable to add an acid monomer such as acrylic acid, methacrylic acid, fumaric acid, and itaconic acid in order to improve the adhesion to glass.

When the adhesive is a blend of a fluororesin component and an acrylic resin component, good compatibility between the two components is important in terms of transparency and adhesive strength. In this respect, it is preferable to use, as the fluororesin component, one containing vinylidene fluoride having good compatibility with the acrylic resin as a main monomer component.

The compatibility can be adjusted by incorporating the above-mentioned copolymer components into both resin components and adjusting the molecular weight of both components. Generally, the number average molecular weight Mn of the fluororesin component is preferably in the range of 40,000 to 150,000, and the number average molecular weight Mn of the acrylic resin component is preferably in the range of 2,000 to 50,000.

As described above, it is preferable to include a vinylidene fluoride-based fluororesin as the adhesive component. Therefore, if a fluororesin sheet containing the common component vinylidene fluoride is used, the adhesiveness between the sheet and the adhesive is high. It is preferable.

The adhesive film is formed by dissolving the above-mentioned adhesive containing the fluororesin component and the acrylic resin component in an organic solvent, uniformly applying the solution on the surface of the glass or fluororesin sheet, and then drying by heating. A method of directly forming a film or a method of uniformly applying and drying an adhesive solution on a releasable substrate, and then transferring the film by heat fusion with a fluororesin sheet, and the like can be used.

In this solution, as a third component, an ultraviolet absorber, a pigment, a plasticizer, a surfactant, a silane coupling agent, an impact modifier, and the like are added as long as the adhesiveness and transparency are not impaired. It is possible.

When an adhesive film is formed on the fluororesin sheet, if there is a possibility of wrinkling on the surface of the fluororesin sheet, a peelable base material is laminated on the back surface of the fluororesin sheet to give a "stiffness". There is also a method in which a peelable substrate is peeled off after forming an adhesive film. If a peelable substrate is used in forming a fluororesin sheet, it can be used as it is.

In forming the adhesive coating on the surface of the fluororesin sheet, the surface of the fluororesin sheet is subjected to a corona discharge treatment, a plasma discharge treatment, and a sodium discharge treatment in order to improve the adhesion between the fluororesin sheet and the adhesive coating. −
Etching or oxidation may be performed by a method such as ammonia treatment.

In order to obtain the glass laminate of the present invention, the above-mentioned adhesive film is formed on the surface of glass, and is bonded to the fluororesin sheet by heating and pressure bonding. It can be formed by heat-pressing and fusing this to glass. Then, the obtained glass laminate is excellent in transparency and adhesive strength, and can also produce a laminate having high flame retardancy.

[0030]

The present invention will be described below with reference to examples. (Example 1) 40% by weight of vinylidene fluoride, 20% by weight of hexafluoropropylene, tetrafluoroethylene 4
A 0 wt% copolymerized fluororesin was extruded by an extruder to obtain a 200 μm thick fluororesin sheet.

As an adhesive, vinylidene fluoride 6
A fluororesin consisting of 1% by weight, 24% by weight of tetrafluoroethylene and 15% by weight of hexafluoropropylene,
95% by weight of methyl methacrylate, ethyl methacrylate
And a 5% by weight acrylic resin in a weight ratio of 70: 3.
The mixture was dissolved in a mixed solvent of butyl acetate and methyl isobutyl ketone (weight ratio: 75:25), and the mixture was applied to a fluororesin sheet with a coater. And the solvent was dried and removed to obtain a bonding sheet having a 1 μm-thick adhesive film on one surface of the fluororesin sheet.

Using this sheet, (a) adhesion and (b) transparency shown below were evaluated. Table 1 shows the results.

(A) Adhesive strength 1) Preparation of a sample A soda glass sheet having a thickness of 3 mm (150 mm × 50 mm) and a fluororesin sheet are superimposed on each other so that the adhesive film is directed to the glass surface, and the resultant is pressed with a hot press machine. ° C, 2Kg / cm ²
Under the conditions described above, pressure and heat were applied for 5 minutes to perform bonding.

2) Normal strength Two notches are made at an interval of 18 mm on the surface of the bonded fluororesin sheet, and the fluororesin sheet between the notches is parallel to the notch direction at an angle of 180 ° at 23 ° C. Peeling was performed at a speed of 5 mm / min, and the adhesive strength (gf / 18 mm) at that time was defined as normal strength.

3) Boil strength After laminating under the above conditions, 2
It was taken out after soaking for a time, and the adhesive force measured in the same manner was defined as the boil strength.

(B) Transparency The materials bonded under the conditions of (a) were visually observed, and the level of transparency was evaluated on a three-point scale.

: Transparent △: slightly cloudy

×: cloudy

Example 2 20% by weight of vinylidene fluoride, tetrafluoroethylene 6
Evaluation was performed in the same manner as in Example 1 except that a sheet of a copolymerized fluororesin of 0% by weight and 20% by weight of hexafluoropropylene was used.

Example 3 As an adhesive, a fluororesin composed of 100% by weight of vinylidene fluoride and an acrylic resin composed of 100% by weight of methyl methacrylate were used in a weight ratio of 5%.
Evaluation was performed in the same manner as in Example 1 except that the one blended at 5:45 was used.

Comparative Example 1 Evaluation was performed in the same manner as in Example 1 except that a fluororesin sheet having no adhesive film was used.

Comparative Example 2 As an adhesive, an acrylic copolymer comprising 95% by weight of methyl methacrylate and 5% by weight of ethyl methacrylate was used, and the thickness of the adhesive film was 1.5 μm. Other than that, evaluation was performed in the same manner as in Example 1.

Comparative Example 3 As adhesives, 61% by weight of vinylidene fluoride, 24% by weight of tetrafluoroethylene,
Evaluation was performed in the same manner as in Example 1 except that a fluororesin composed of 15% by weight of hexafluoropropylene was used, and the thickness of the adhesive film was 1.5 μm.

(Comparative Example 4) A tetrafluoroethylene-vinyl ester copolymer (manufactured by Central Glass Co., Ltd .; Cefuralcoat A-402B) was used as an adhesive, and the thickness of the adhesive film was 1.5 μm. Except for the above, evaluation was performed in the same manner as in Example 1.

Comparative Example 5 A partially saponified ethylene-vinyl acetate copolymer resin (Takeda Pharmaceutical Co., Ltd.) was used as an adhesive.
Manufactured by Takemelt SD-181), the thickness of the adhesive film was set to 2 μm, and the other conditions were evaluated in the same manner as in Example 1.

Comparative Example 6 Evaluation was performed in the same manner as in Example 1 except that the thickness of the adhesive film was 2 μm using polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd.).

(Comparative Example 7) As an adhesive, an epoxy adhesive (manufactured by Ciba-Geigy; Araldite AER280)
The evaluation was performed in the same manner as in Example 1 except that the thickness of the adhesive film was 5 μm.

(Comparative Example 8) As an adhesive, a silicone-based adhesive (manufactured by Konishi Co., Ltd .; Bond MOS-7) was used.
Evaluation was performed in the same manner as in Example 1 except that the thickness of the adhesive film was 5 μm. Table 1 shows the results of these evaluations.

[0049]

[Table 1]

As is clear from the results shown in Table 1, in the examples using the adhesive containing the fluorine resin component and the acrylic resin component, a laminate having excellent transparency and adhesive strength was obtained.

[0051]

According to the present invention, glass and a fluororesin sheet can be laminated firmly and with high transparency, and the resulting laminate has flame retardancy. it can.

Claims (2)

[Claims] 1. A method according to claim 1, wherein the glass and the fluororesin sheet are combined with a fluororesin component of 40 to 80% by weight and an acrylic resin component of 60 to
A glass laminate, wherein the glass laminate is bonded by an adhesive containing 20% by weight. 2. At least one side of a fluororesin sheet,
A fluororesin sheet for bonding glass, comprising an adhesive film containing 40 to 80% by weight of a fluororesin component and 60 to 20% by weight of an acrylic resin component.