JPH1087351A - Glass laminated body and sheet for lamination - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glass laminated body excellent in flame resistance, transparency and adhesive strength and to obtain a sheet for lamination used for the glass laminated body. SOLUTION: Glass is stuck to a fluororesin sheet having >=55wt.% fluorine content with an adhesive coating film to obtain the objective glass laminated body. The total light transmissivity of the fluororesin sheet is >=90% and the thickness of the adhesive coating film is 0.003-10μm. When the refractive index of the adhesive coating film and that of the fluororesin sheet are represented by Na and Nb, respectively, the absolute value of (Na-Nb), that is, |Na-Nb| |is <=0.13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluororesin sheet for bonding which has a good appearance when bonded to glass,
And a laminated body obtained by laminating glass and a fluororesin sheet, more specifically, a flame-retardant laminating sheet and a glass laminated body which do not impair the characteristics of transparent glass even when laminating a fluororesin sheet and glass. To provide.

[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.

In order to ensure flame retardancy, it is necessary to use a fluorine resin sheet having a fluorine content of 55% by weight or more, preferably 60% by weight or more. Because of poor adhesion to materials, it is necessary to use an adhesive to achieve strong adhesion.

In such a case, it is necessary to perform bonding so as not to impair the high transparency of the glass. Conventionally, a bonding sheet that can be bonded to glass with high transparency while maintaining flame retardancy is not available. Had not been proposed.

[0005]

SUMMARY OF THE INVENTION The present invention provides a laminated sheet and a glass laminate which enable the production of a laminated glass having both flame retardancy and high transparency. Is a glass laminate in which glass and a fluorine resin sheet having a fluorine content of 55% by weight or more are bonded by an adhesive film, and the total light transmittance Tb (%) of the fluorine resin sheet is 90 or more, Film thickness D
a (μm) is 0.003 to 10, the refractive index of the adhesive film is Na, and the refractive index of the fluororesin sheet is Nb.
The absolute value of (Na-Nb), | Na-Nb |, is 0.13 or less.

The gist of another invention is that the fluorine content is 5%.
5% by weight or more of a fluororesin sheet for bonding to glass having an adhesive film provided on the surface thereof, wherein the total light transmittance Tb (%) of the fluororesin sheet is 90 or more, and the thickness of the adhesive film is Da (μm) is 0.003 to 10, the refractive index of the adhesive film is Na, and the refractive index of the fluororesin sheet is Nb.
When represented by the absolute value of (Na-Nb), | Na-Nb
| Is 0.13 or less.

In this laminating sheet, Da
(Μm) is 0.01 or more and Da × | Na−
It is preferable that Nb | ≦ 0.1. Furthermore, it is particularly preferable that Da (μm) is in the range of 0.05 to 0.5 and that Da × │Na-Nb│ ≦ 0.03.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The fluororesin sheet used in the present invention is a monomer.
The component is a homopolymer or copolymer of a fluorinated monomer such as vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, pentafluoropropylene, hexafluoropropylene, or the fluorinated monomer. A copolymer in which vinyl monomers such as ethylene and acryl vinyl ether are used in combination,
Alternatively, a mixture of these materials having a fluorine content of 55% by weight or more, preferably 60% by weight or more is selected in order to ensure flame retardancy.

[0009] Any material having a heat melting property capable of being formed into a sheet shape may be used, and a fluorine resin other than a homopolymer of tetrafluoroethylene (PTFE) can be used.

Specifically, a tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer,
Examples thereof include a tetrafluoroethylene-vinylidene fluoride-hexafluoropropylene copolymer and polyvinylidene fluoride.

This fluororesin sheet has a total light transmittance T
It is necessary that b (%) is 90% or more. 90%
If it is less than the above, transparency is impaired when bonded to glass. Total light transmittance Tb of fluororesin sheet
Can be adjusted by the composition of the fluororesin, the thickness of the sheet, the conditions for forming the sheet, the type and amount of the additive, and the like.

Although the thickness of the fluororesin sheet is not particularly limited, the thickness of the fluororesin sheet satisfies the above condition of the total light transmittance and the effect on the impact resistance when laminated with glass is taken into consideration.
A range of 50 to 2000 μm is preferred.

The fluororesin sheet may be formed 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 off from the base material to form a sheet, a method of drying water after uniformly applying a water-based dispersion of a fluororesin on a removable base material, or
A method of forming a sheet by thermoplastic molding such as an extrusion method and a calendar method 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. The adhesive coating is provided on at least one side, preferably both sides, of the fluororesin sheet.
The thickness of the adhesive film (the thickness of one surface when provided on both surfaces of the fluororesin sheet) is Da (μm), the refractive index of the adhesive film is Na, and the refractive index of the fluororesin sheet is Nb. At this time, it is necessary that 0.003 ≦ Da ≦ 10 | Na-Nb | ≦ 0.13.

Here, the thickness Da of the adhesive film is 0.00
If it is less than 3 μm, a sufficient adhesive force cannot be obtained between the glass and the fluororesin sheet, and if it exceeds 10 μm, the transparency will be impaired when laminated with glass.

In the relationship between the fluororesin sheet and the adhesive film, when the refractive index of the fluororesin sheet is represented by Nb and the refractive index of the adhesive film is represented by Na, the absolute value of (Na-Nb), | Na-Nb | must be 0.13 or less. When | Na-Nb | exceeds 0.13, when adhered to glass, due to the difference in refractive index,
Cloudiness increases.

Preferably, Da is 0.01 μm or more, and the product of Da and | Na-Nb |
It is desirable that a-Nb | is 0.1 or less.

Within this range, the adhesive strength between the glass and the fluororesin sheet is ensured, and the transparency of the laminate is maintained. As the value of Da × | Na-Nb | exceeds 0.1, the transparency of the laminate gradually decreases.

Particularly preferably, Da (μm) is 0.0
It is in the range of 5 to 0.5, and Da × | Na-Nb | ≦ 0.03.

The material of the adhesive film is not particularly limited as long as it satisfies the above conditions. For example, silane coupling agents, epoxy adhesives, rubber adhesives, polyurethane adhesives, polyester adhesives, acrylic adhesives, silicone adhesives, polyamide adhesives,
Polyolefin-based adhesives, polyvinyl ether-based adhesives and the like can be used alone or as a mixture of two or more.

Since the adhesive film is subsequently bonded to the glass by heating, it is desirable that the adhesive film is thermoplastic or latent thermosetting in which polymerization and curing proceed by heating.

The method for forming the adhesive coating on the fluororesin sheet can be a generally known method, and is not particularly limited. For example, a method in which an adhesive material is uniformly applied on a peelable substrate, dried to form an adhesive film, and then heated and transferred to a fluororesin sheet, and the adhesive material is directly applied directly to the fluororesin sheet. Then, a method of directly forming an adhesive film by drying after drying is possible. The adhesive for forming a film is preferably in a low-viscosity form from the viewpoint of obtaining a thin film, and a solution system, a solvent system, an emulsion system, a reactive monomer-dilution system and the like are used.

In the case of forming an adhesive film on the glass side, a generally known method can be applied, and there is no particular limitation. Various additives can be added to the adhesive coating as long as the above-mentioned properties of the adhesive coating are not impaired.

In forming the adhesive film on the surface of the fluororesin sheet, the surface of the fluororesin sheet is previously subjected to corona discharge treatment, plasma discharge treatment, sodium discharge for the purpose of improving the adhesion between the fluororesin and the adhesive film. It is also possible to perform etching or oxidation by a method such as ammonia treatment.

In the present invention, it is preferable to emboss the surface of the fluororesin sheet provided with the adhesive film having the above-mentioned properties. Embossing allows air between the glass and the adhesive coating to escape during bonding to the glass, thereby reducing the remaining bubbles.

By sandwiching the above-described bonding sheet between two or more transparent glass plates and applying heat and pressure, a laminated glass having high transparency and excellent flame retardancy can be obtained. Similarly, the same laminated glass can be obtained by forming an adhesive film on the glass surface, heating and pressing with a fluororesin sheet interposed therebetween.

[0027]

The present invention will be described below in detail with reference to examples. In addition, the test evaluation of each characteristic was performed by the following method. (A) Fluorine content From the monomer composition of the fluororesin, the weight% of the total weight of fluorine atoms relative to the total weight of the fluorine resin constituent atoms was calculated. (B) Total light transmittance (Tb) of fluororesin sheet Measured according to JIS K 7105.

(C) Refractive index Nb, Na Using an Abbe refractometer, measurements were made using the D line of Na as a light source.

The refractive index Nb of the fluororesin sheet was measured as it was, while the Na of the adhesive film was separately coated with an adhesive on a 100 μm sheet of polytetrafluoroethylene and dried. It was measured as a film of the agent alone.

(D) Adhesive Coating Thickness Tb The cross section of the bonding sheet (the cross section of glass in Example 6) was observed with a scanning electron microscope, and the thickness of the adhesive coating was measured.

(E) Transparency of laminated glass The laminated sheet is sandwiched between two 3 mm-thick soda glass plates (50 mm × 150 mm) at a temperature of 130 mm.
Attachment was performed by pressing at a temperature of 5 ° C. and a pressure of 5 kg / cm ² for 10 minutes, and the transparency of the obtained laminate was visually evaluated in four steps.

◎ Transparent ○ Almost transparent △ Slightly cloudy × Cloudy (f) Adhesive strength of laminated glass Soda glass having a thickness of 3 mm (50 mm × 150 mm) /
Laminating sheet / polytetrafluoroethylene 1
The layers were laminated in the order of a 00 μm film, pressed at a temperature of 140 ° C. under a pressure of 2 kg / cm 2 for 5 minutes, laminated, and then the polytetrafluoroethylene film was peeled off to obtain a laminated body of a glass / laminate sheet. Then, two notches are inserted into the bonding sheet at an interval of 18 mm, and the sheet between the notches is peeled at a speed of 5 mm / min at 23 ° C. at an angle of 180 ° parallel to the notch direction, and the peel strength at that time (Normal strength).

After lamination, the pieces were immersed in boiling water at 100 ° C. for 2 hours, taken out, and subjected to a peeling test under the same conditions. The strength at that time was defined as the boiling strength. The unit is gf / 1
8 mm.

Example 1 A copolymerized fluororesin consisting of 40% by weight of vinylidene fluoride, 40% by weight of tetrafluoroethylene and 20% by weight of hexafluoropropylene was extruded at 180 ° C. by an extruder to obtain a fluororesin having a thickness of 200 μm. I got a sheet.

On both sides of the fluororesin sheet, a solution comprising a mixture of a fluororesin containing vinylidene fluoride as a main component and an acrylic resin containing methylmethacrylate as a main component as an adhesive (Novafuso PF) -250
C-2: Dainippon Color Material Co., Ltd.) was directly applied and dried to form an adhesive film having a thickness of 0.4 μm.

The fluorine content, the total light transmittance Tb and the refractive index Nb of the obtained fluororesin sheet were measured, and the refractive index Na of the adhesive film alone was measured.
And the thickness Db of the adhesive film was measured. Further, a laminated glass was manufactured using the bonding sheet, and its transparency and adhesive strength were evaluated.

Example 2 The thickness of the adhesive film was 0.1 μm.
The same test as in Example 1 was performed except that m was used.

(Example 3) Example 3 was repeated except that a solution of an acrylic resin containing methyl methacrylate as a main component (trade name: Acridic BZ-1161, manufactured by Dainippon Ink and Chemicals, Inc.) was used as the adhesive. The same test as in No. 2 was performed.

Example 4 The thickness of the adhesive film was set to 1.0 μm.
The same test as in Example 1 was performed except that m was used.

Example 5 The thickness of the adhesive film was 0.03
The same test as in Example 1 was performed except that the thickness was set to μm.

(Example 6) A silane coupling agent layer (γ-aminopropyltriethoxysilane) having a thickness of 0.005 μm was formed as an adhesive film on two sheets of glass, and the fluororesin sheet of Example 1 was interposed between the two layers. Then, the same test as in Example 1 was performed.

Example 7 The same test as in Example 1 was performed except that the thickness of the adhesive film was 6 μm.

Example 8 The same test as in Example 3 was conducted except that an adhesive film having a thickness of 2 μm was formed with the adhesive used in Example 3.

(Comparative Example 1) The same test as in Example 1 was conducted except that a solution of an equal weight mixture of polyvinyl chloride and polymethyl methacrylate was used as the adhesive to be used.

(Comparative Example 2) The thickness of the adhesive film was 12 μm
The same test as in Example 1 was performed except that the test was performed. (Comparative Example 3) The same test as in Example 1 was performed except that an ethylene-tetrafluoroethylene copolymer sheet was used as the fluororesin sheet.

The above results are shown in Tables 1 and 2.

[0047]

[Table 1]

[0048]

[Table 2]

As is clear from the results shown in Tables 1 and 2,
Those within the specified range of the present invention are excellent in overall evaluation of △ or more. In particular, Examples 1 to 3 had high levels of transparency and adhesive strength, and were extremely excellent.

[0050]

According to the present invention, it is possible to obtain a glass laminate having flame retardancy, high transparency, and strong adhesive strength, and a laminating sheet therefor.

Claims (4)

[Claims] 1. A glass laminate in which glass and a fluororesin sheet having a fluorine content of 55% by weight or more are bonded by an adhesive film, and the total light transmittance Tb (%) of the fluororesin sheet is 90 or more. , The thickness Da of the adhesive film (μ
m) is 0.003 to 10, the refractive index of the adhesive film is Na,
When the refractive index of the fluororesin sheet is represented by Nb, (Na
The absolute value of -Nb), | Na-Nb |, is 0.13 or less. 2. A sheet for bonding to a glass having a fluorine content of 55% by weight or more provided with an adhesive film on the surface of a fluororesin sheet having a total light transmittance Tb (%) of the fluororesin sheet. 90 or more, the thickness Da (μ
m) is 0.003 to 10, the refractive index of the adhesive film is Na,
When the refractive index of the fluororesin sheet is represented by Nb, (Na
-Nb), wherein the absolute value | Na-Nb | is 0.13 or less. 3. The bonding sheet according to claim 2, wherein Da (μm) is 0.01 or more and Da × | Na-Nb | ≦ 0.1. 4. The laminating sheet according to claim 2, wherein Da (μm) is in the range of 0.05 to 0.5 and Da × | Na−Nb | ≦ 0.03. .