JPH0822767B2 - Method for producing laminated safety glass having thermosetting polyurethane coating layer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing laminated safety glass having a novel thermosetting polyurethane coating layer on the surface of a glass plate, and a coating process of a thermosetting urethane liquid. The coating layer of the thermosetting polyurethane can be easily laminated on the glass plate surface by a series of steps including the defoaming / leveling process of the coating film, and the heating process for spraying the coating film with the solvent and thermosetting. It is intended to provide a novel method for producing a laminated safety glass, which is excellent in productivity and has no external appearance problem such as perspective distortion.

[Problems to be Solved by Conventional Techniques and Inventions] Laminated safety glass in which a conventionally known inorganic glass or the like and a synthetic resin film are laminated together prevents damage and scattering of fragments at the time of impact destruction of window glass or the like. It is intended to be used, and is used as window glass for automobiles and window glass for construction, which has improved safety.

There are various types of laminated safety glass, but the one with synthetic resin applied to the surface of the glass plate has the advantage that it is less damaged due to scattering of fragments when the glass is broken, and is lightweight. ing. Among them, those having a synthetic resin film made of urethane resin have sufficient impact resistance and penetration resistance, and have preferable characteristics.
No. 57, etc. In particular, since the thermosetting urethane resin has a self-repairing property, even if a deformation such as unevenness occurs on the film surface due to an external force, it has been noted as having a property when it is restored (Japanese Patent Publication No. 58-29815). JP-B-57-27050, JP-A-60-71252, JP-A-SHO
60-71253, JP 61-138671, JP 61
-138672 publication).

Conventionally, the production of such laminated safety glass is usually carried out by bulk casting without using a solvent, after forming a synthetic resin film once on the surface of a supporting substrate such as a polyester film or glass plate, and then peeling it off and adhering it to a glass plate or the like. A method of laminating on a body by vacuum pressure bonding, thermocompression bonding, or the like through an adhesive, a thermoplastic interlayer film, or the like is used. Since this is divided into a film forming process and a laminating process, the process is complicated and the productivity is poor. In addition, appearance problems such as smoothness and perspective distortion when combined with glass occur due to the inclusion of foreign matter in the lamination process and the difficulty of forming an adhesive thin film with a uniform thickness when using an adhesive. There is also a drawback that it is easy to do.

In order to improve the adhesiveness of thermosetting polyurethane without using an adhesive, an attempt to laminate it with thermoplastic polyurethane is shown in Japanese Patent Publication No. 63-28791, but the process is complicated and foreign matter is mixed. The problem of perspective distortion due to is similar.

Some laminated safety glasses are applied to window glasses for construction or automobiles, and it is required that there is no problem of perspective distortion as described above.

[Means for Solving the Problem] The inventors of the present invention have earnestly studied to solve the problems of the productivity in the production of conventional laminated safety glass and the problem of the perspective distortion. For example, the thermosetting polyurethane resin film can be formed and laminated on the glass plate surface by at least one coating operation by a series of processes including painting process, defoaming / leveling process, and heating process. That is, the present invention has been completed.

That is, the present invention is a thermosetting urethane liquid having an isocyanate, a polyol and a solvent on the surface of the glass plate in a method for producing a laminated safety glass comprising a laminate of a glass plate and a coating layer of thermosetting polyurethane. Then, a coating step of applying a thermosetting urethane liquid in which an adhesive for adhering the glass plate and the thermosetting polyurethane and a surface smoothing agent are further applied to the liquid, and degassing the gas in the coating liquid. And / or a coating process of thermosetting polyurethane characterized by having a defoaming / leveling process for uniforming the film thickness deviation, and a heating process for scattering the solvent of the thermosetting urethane liquid and curing the thermosetting urethane liquid. It is a manufacturing method of laminated safety glass having layers.

Explaining the present invention in detail, the thermosetting polyurethane solution used in the coating step of the method for producing a laminated safety glass comprising the thermosetting polyurethane coating layer of the present invention is a solution containing an isocyanate polyol and a specific solvent. Say.

Here, the isocyanate and the polyol are monomers that can form a thermosetting polyurethane, and the following are exemplified.

Isocyanates: for example, 1,6-hexanediisocyanate, 2,2,4- and 2,4,4-trimethyl-1,6-hexanediisocyanate, 1,3-bis (isocyanatomethyl) benzene, bis (4-isocyanatocyclohexyl) ) Methane, bis (3-methyl-4-isocyanatocyclohexyl) methane, 2,2-bis (4-isocyanatocyclohexyl) propane, and bifunctional isocyanates such as 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, Alternatively, these tri- or polyfunctional burette modified products, isocyanurate modified products, prepolymer modified products and the like.

Polyol: For example, 1,2,3-propanetriol [glycerol], 2,2-bis (hydroxymethyl)-
1-propanol [trimethylolethane], 2,2-bis (hydroxymethyl) -1-butanol [trimethylolpropane], 1,2,4-butanetriol, 1,2,6-hexanetriol, 2,2- Bis (hydroxymethyl)-
1,3-propanediol [pentaerythritol], 1,
Polyfunctional alcohols such as 2,3,4,5,6-hexanehexol [sorbitol] and malonic acid, succinic acid,
Aliphatic dibasic acids and polyesters such as glutaric acid, adipic acid, suberic acid, and sebacic acid, the above polyfunctional alcohols, aliphatic dibasic acids, and cyclic structures such as ethylene oxide, 1,2-propylene oxide, and tetrahydrofuran. Polyester obtained by reacting with ether, or polyether polyol. The molecular weight of the polyol is preferably in the range of about 250 to 4000, preferably about 450 to 2000. Mixtures of different polyisocyanates and polyol monomers can also be used.

The specific solvent is composed of a diluting solvent for the thermosetting polyurethane liquid, and certain additives such as an adhesive and a surface smoothing agent.

The diluting solvent is used to make the viscosity of the thermosetting polyurethane liquid suitable for a flow coater, and an organic solvent that does not hinder the progress of the urethane reaction and film formation, for example, a benzene solvent is used. For example, xylene, butyl acetate, cellosolve acetate, methyl isobutyl ketone, etc. are used.

The viscosity of the thermosetting urethane liquid adjusted by the diluting solvent needs to be 50 cp to 150 cp. That is, if the viscosity is higher than this, curtain breakage will occur during so-called flow coating and it is not appropriate. If the viscosity is lower than this, thermosetting polyurethane liquid is applied to a predetermined film on the glass plate surface by a flow coater. It is difficult to apply a film having a thickness of, for example, about 300 μm to 700 μm, and it is difficult to produce a useful laminated safety glass having high impact resistance with sufficient impact resistance by one-time flow coating. This is because it is disadvantageous in manufacturing.

The adhesive is a coating of at least one layer of thermosetting polyurethane, which is added to provide satisfactory adhesiveness to glass, and the silane coupling agent is optimally applied. The amount of such adhesive added is 0.1%
.About.0.5%, more preferably 0.15% to 0.2%. That is, if it is less than this, the adhesiveness cannot be improved and it is not appropriate, and if it is more than this, the shock absorbing property is lowered.

The surface smoothing agent is added in order to improve the smoothness of the thermosetting urethane film and to exhibit a high degree of optical characteristics without perspective distortion. For example, a silicon-based surface smoothing agent is optimally used. The amount of such surface smoothing agent added is 0.1% to
It is desirable to be 0.5%, more preferably 0.15% to 0.2%. That is, if it is less than this, smoothness cannot be achieved, and if it is more than this, appearance defects such as haze occur due to compatibility problems.

In order to apply the thermosetting polyurethane liquid having the above composition onto the glass plate surface, it is desirable to use a flow coater. This is because the coating liquid can be applied uniformly and the smoothness of the coated surface can be achieved. When the flow coater is operated, the viscosity of the thermosetting urethane liquid increases due to the natural volatilization of the solvent in the thermosetting urethane liquid. Therefore, it is necessary to adjust for the change in film thickness due to the change in viscosity. In this case, either adjust the line speed to keep the set film thickness constant, or continuously add the volatile solvent to keep the liquid viscosity constant. Should be kept constant.

The film thickness of the coating liquid is appropriately selected according to the required impact resistance or the number of times of coating with a flow coater. For example, when it is desired to obtain sufficient impact resistance with one coating. Is a coating liquid film thickness of 300 μm or more, more preferably 4
It is desirable that it is from 00 μm to 600 μm. If it is less than this, the synthetic resin film becomes too thin, and it is difficult to produce a useful laminated safety glass with one coating. If it is more than this range, the spill of the liquid from the glass plate or the difference in the solvent volatilization speed between the inside of the coating liquid and the surface becomes too large, and appearance defects such as wrinkles occur on the surface.

In the defoaming / leveling step in the method for producing a laminated safety glass comprising the thermosetting polyurethane coating layer of the present invention, the coating film applied by the flow coater includes the bubbles entrained in the circulation of the flow coater, and the coating liquid is glass. This is done in order to remove the bubbles that are entrained when they fall into the surface, and to promote smoothing because they do not have a perfect smooth surface immediately after being applied. That is, the inclusion of bubbles in the coating film causes a defect in appearance during film formation, making it impossible to achieve high optical properties of safety glass. Also, the film strength may be lowered depending on the amount of bubbles. Further, promotion of smoothing is preferable for facilitating manufacturing and achieving high optical characteristics.

It is desirable to use an ultrasonic wave transmitter for the defoaming / leveling process. By applying such a device,
The defoaming rate can be accelerated about 10 times.

Specifically, defoaming leveling is performed by placing the vibrator plate on the opposite side of the glass plate from the coated surface. The frequency of the oscillator plate is
It is desirable that the frequency is higher than that of an ordinary ultrasonic cleaner and is 50 kHz to 65 kHz, more preferably 60 kHz to 65 kHz, but it is not limited to this range. The time for applying ultrasonic vibration is preferably about 1 to 10 minutes. This is because if it is less than this, promotion of defoaming and leveling cannot be sufficiently achieved.

The heating step in the method for producing a laminated safety glass having a thermosetting polyurethane coating layer of the present invention includes the first heating for the purpose of leveling and solvent scattering of the coating film of the thermosetting urethane liquid, and the thermosetting reaction of urethane. And second heating for the purpose of forming a resin film.

The first heating is performed at an ambient temperature of 60 ° C or higher, preferably 65 to 90 ° C, and the second heating is 110 ° C or higher, more preferably 1
Perform at an ambient temperature of 15 ° C to 140 ° C. As a heating device,
It is preferable to use a far-infrared heater for ease of use on the device surface, but it is not limited to these. Further, the interval between the coating film as the object to be heated and the heater is not particularly limited, but an example is a range of 100 mm or more, preferably about 200 to 300 mm. The heating time is also the heating temperature,
Although it depends on the thickness of the coating film and other conditions, a range of 20 minutes to 45 minutes in the first heating step and a range of 5 minutes to 20 minutes in the second step can be given as an example.

The film thickness of the thermosetting urethane liquid applied to a thickness of, for example, about 500 μm by the above heating process is about
It becomes a polyurethane resin film with a thickness of 300 μm.

Such a resin film is a thermosetting polyurethane single layer film, and is directly laminated and adhered onto the glass plate surface by the series of steps described above. That is, according to the present invention, the thermosetting polyurethane film can be formed and the resin film can be laminated and adhered to the glass plate surface at the same time by a single coating operation. It is possible to efficiently manufacture a laminated safety glass consisting of. Even though it is a single coating layer, the laminated safety glass produced is a useful laminated safety glass that has excellent adhesiveness, smoothness, energy absorption, debris scattering prevention, internal protection and self-healing properties. Is. If a polyurethane resin film having a required film thickness cannot be obtained by coating once, the same process can be repeated to repeat coating twice or three times.

However, it goes without saying that the above description is intended to help understanding of the present invention and does not limit the present invention in any way.

Next, the present invention will be described more specifically with reference to the present invention. In the text, parts or% are based on weight. In addition,
As the apparatus, the coating apparatus shown in Fig. 1 was used.

Example 1 A thermosetting urethane monomer having the following composition was diluted with a benzol solvent having the following composition to obtain a liquid viscosity.
It was set to 70 cp.

Urethane monomer composition Polycaptolactone polyol 26.5 parts Neopentyl glycol 4.0 parts Nurate modified hexamethylene diisocyanate 34.5
Part Diluent Butyl acetate 11.7% Cellosolve acetate 11.7% Xylene 11.7% To this, a silane coupling agent 0.2% and a silicon-based surface smoothing agent 0.2% were added as an adhesive.

The thermosetting urethane solution 2 having the above composition was applied to a glass plate 1 surface (thickness 6 mm, vertical dimension: 183 by a flow coater 3).
0, lateral dimension: 91.5 mm) was applied under the following conditions.

Flow coating conditions Viscosity: 150cp Conveyance speed of glass plate: 14m / min Film thickness of applied urethane liquid: 500μm (film thickness before curing) Flow coater circulation rate (effective width = 2100mm): 15Kg / min Next, Guide the glass plate 1 coated with the above-mentioned thermosetting urethane solution 2 onto the vibrator plate 5 of the ultrasonic transmitter 4, and 63
Vibration was performed at 5 kHz for 5 minutes to perform defoaming and leveling.

Next, the first heating device 6 having the far infrared heater 8
To an atmosphere of 70-80 ° C (average W density 0.20-0.25W / cm
^It was placed in ² ) for 20 to 30 minutes to smooth the coating surface and to scatter the solvent.

The thing which was touch-cured by the first heating was introduced to the second heating device 7 having the far infrared heater 8 and was put in an atmosphere of 120 to 130 ° C. (average W density 0.35 to 0.40 W / cm ² ) for 10 to 15 minutes. Every
The urethane was cured. The distance between the object to be heated and the far infrared heater 8 is 250 mm in both the first step and the second step.
And

As a result, after the coating step (a), the defoaming / leveling step (b), and the heating step (c), a film thickness of 325 μ was formed on the glass plate surface.
It has a thermosetting urethane film. The laminated safety glass was excellent in adhesiveness and smoothness, energy absorption, fragment scattering prevention, internal protection and self-healing.

Comparative Example 1 Among the thermosetting urethane liquids of Example 1, those in which an adhesive and a surface smoothing agent were not added were coated on a glass plate surface with a film thickness of 500 μm by a flow coater, followed by defoaming / leveling process and heating process. Was carried out in the same manner as in Example 1 to obtain a laminated safety glass.

When this product was exposed to moisture, the bond between the thermosetting polyurethane and the glass weakened, and it was not put to practical use.

Comparative Example 2 A laminated safety glass was obtained by performing the coating process and the heating process in the same manner as in Example 1 without passing through the defoaming / leveling process.

This product contained air bubbles in the thermosetting polyurethane resin film and was inferior in smoothness, and was not put to practical use.

Comparative Example 3 The second heating step of the first embodiment except the first heating step
A laminated safety glass was obtained in the same manner as in Example 1 except that the heating was performed for a long time to deal with the problem.

Not only was this film unable to obtain sufficient film surface smoothness, but it also contained bubbles in the film, which was a defect in appearance. Further, since the solvent was not sufficiently volatilized and the resin was cured, a thinner component remained in the film and the film strength was lowered, and the above-mentioned characteristics were obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view showing one embodiment of the present invention. The numbers in the figure indicate the following, respectively. 1: Glass plate 2: Thermosetting urethane liquid 3: Flow coater 4: Ultrasonic transmitter 5: Transducer 6: First heating device 7: Second heating device 8: Far infrared heater a): Painting process b) : Defoaming / leveling process c): Heating process

Claims (5)

[Claims] 1. A method for producing a laminated safety glass comprising a laminate of a glass plate and a thermosetting polyurethane coating layer, which is a thermosetting urethane liquid having an isocyanate, a polyol and a solvent on the surface of the glass plate. hand,
Further, a coating step of applying a thermosetting urethane liquid in which an adhesive for adhering the glass plate and the thermosetting polyurethane and a surface smoothing agent are added to the liquid, and degassing and / or degassing the gas in the coating liquid. Alternatively, a laminate having a coating layer of thermosetting polyurethane characterized by having a defoaming / leveling step for equalizing the film thickness deviation and a heating step for scattering the solvent of the thermosetting urethane solution and curing the thermosetting urethane solution. Method for manufacturing safety glass. 2. The method for producing a laminated safety glass having a thermosetting polyurethane coating layer according to claim 1, wherein the coating step comprises applying a thermosetting urethane liquid by a flow coater. 3. A method for producing a laminated safety glass having a thermosetting polyurethane coating layer according to claim 1, wherein the thermosetting urethane liquid has a viscosity of 50 to 150 cp and a solid content of 60 to 70%. . 4. The method for producing a laminated safety glass having a thermosetting polyurethane coating layer according to claim 1, wherein the defoaming / leveling step uses an ultrasonic transmitter. 5. The heating step is performed for the purpose of scattering the solvent to 70-80.
The thermosetting polyurethane according to claim 1, comprising a first heating step at an ambient temperature of ℃ and a second heating step at an ambient temperature of 120 to 130 ° C for the purpose of a thermosetting reaction of urethane. A method for producing a laminated safety glass having a coating layer.