JPH0269338A - Production of window glass for vehicle - Google Patents

Abstract

PURPOSE:To obtain the title glass capable of desirably removing deposits generated depending on conditions of weather or running, etc., by applying and baking a siloxane type polymer on one surface of a glass plate plural times, and forming thus a transparent thin film having high slipping characteristic and weather resistance. CONSTITUTION:A siloxane type polymer is coated plural times on one surface of a window glass for vehicle comprising general soda lime glass, and baked thereon. Suitable siloxane type polymer is one having 500-1000cSt viscosity and comprising, for example, polydimethyl siloxane, etc. The glass plate to be coated with the polymer is preferred to be wiped with dil. HCl, etc., before applying the polymer thereto in order to improve the adhesion and the weather resistance. The coating and baking Are pref. performed 2 4 times, and preferred baking temp. is 250-350 deg.C. By the above described method, a window glass for vehicle causing hardly scratches on the surface and maintaining satisfactory field of view is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing vehicle window glasses such as windshield glasses and back window glasses.

[Prior Art] A typical vehicle window glass has a structure in which soda lime glass or the like is exposed as is.

In addition, in order to remove water droplets that adhere to vehicle windshields, we use a glass plate that serves as the base material of the windshield, a transparent film attached to its outer surface, and a highly water-repellent liquid that is applied on top of the glass plate. A vehicle windshield comprising an oil-absorbing layer impregnated with
Publication No. 813).

[Problems to be Solved by the Invention] The above-mentioned general vehicle window glass has a problem that the sliding property is not sufficient and the surface is easily damaged. In other words, muddy water splashed up by other vehicles adheres to the windshield when driving after rain, and it freezes in the winter.
When it snows, snow adheres to it, and when it melts, water droplets, muddy water, small bits of asphalt scraped by spiked tires, etc. adhere to it, and in some areas, dust such as volcanic ash adheres to it. In these cases, the driver sprays washer fluid onto the windshield and operates the wiper in an attempt to remove the deposits. However, the washer
The amount of liquid sprayed may be insufficient, or the washer may not be spraying enough water.
If the liquid is used up while driving, the deposits will adhere to the windshield, forcing the wipers to operate. As a result, the surface of the windshield may be damaged by sand from the muddy water caught between the wiper blade rubber and the windshield itself, and visibility may be blocked.

Further, the vehicle window glass described in the above-mentioned publication is not practical due to its wear resistance.

The present invention has been made with attention to the above-mentioned problems, and is a vehicle-use product that can suitably remove deposits that adhere due to weather, driving conditions, etc., has a surface that is less likely to be damaged, and can maintain good visibility. The purpose of the present invention is to provide a method for manufacturing window glass.

[Means for Solving the Problems] The method for manufacturing a vehicle window glass of the present invention involves coating a glass plate with a siloxane polymer multiple times and baking it to produce transparent 1i1111 with excellent sliding properties and abrasion resistance. It is characterized by forming.

Here, the glass plate is glass used in conventional vehicle window glasses, and is made of soda lime glass or the like. Further, tempered glass, laminated glass, etc. may also be used. One side of the glass plate to which the siloxane-based polymer is applied and baked is the outer surface when installed on the vehicle.

As the siloxane polymer, polydimethylsiloxane, polyphenylmethylsiloxane, etc. are preferably used. This siloxane polymer has a viscosity of 500 to 1
The concentration is preferably about 0QQcs, and when diluting with a solvent such as hexane, the concentration is preferably 0.1 to 5 wt%. This is because it has excellent adhesion to glass plates, sliding properties, water repellency, and abrasion resistance.

Adhesion and abrasion resistance can be improved by wiping the glass plate with dilute hydrochloric acid or the like before application.

Coating and baking are preferably carried out 2 to 4 times. one application,
Baking does not provide sufficient abrasion resistance, so applying it more than 5 times,
On the contrary, baking may worsen wear resistance.

The baking temperature is 250℃ for excellent adhesion and wear resistance.
~350°C is preferred.

In addition, from the viewpoint of wear resistance, it is preferable to wipe off the uncured siloxane polymer during the baking stage.

[Effect 1: The transparent idI film formed on one side of the glass plate is made of a siloxane-based polymer with a small coefficient of friction, so it has excellent sliding properties.Since this siloxane-based polymer is coated and baked multiple times, it has excellent wear resistance. Excellent. Therefore, water droplets, muddy water, and other substances adhering to the surface of the windshield can be easily removed without sticking to the windshield, and the surface is less likely to be damaged by, for example, operating a wiper.

[Example] Hereinafter, embodiments embodying the present invention will be described.

First, a glass plate 1, which is used for mounting on a windshield glass of a vehicle, was prepared. This glass plate 1 is made of soda lime glass. This glass plate 1 was subjected to alkaline ultrasonic cleaning, water washing, and fluorocarbon ultrasonic cleaning. Further, a silicone solution was prepared by diluting polydimethylsiloxane having a viscosity of 1000 cs with an n-hexane solvent to a concentration of 0.5 wt%.

Approximately 10 g/m' of this silicone solution was applied to the outer surface of the washed glass plate 1 using a roll coater and dried at approximately 70°C for 15 minutes. Thereafter, the glass plate 1 coated with the silicone solution was kept in the dark at 300° C. for 20 minutes to bake the silicone solution.

When the baked silicone solution was checked, it was found that it had hardened at the glass interface, but the surface was still unhardened. Therefore, the uncured silicone solution was wiped off using 0.01N diluted hydrochloric acid, and then the silicone solution was applied and baked two more times. In this way, windshield glass was manufactured.

A cross section of this windshield glass is shown in FIG. This windshield glass consists of a glass plate 1 and a transparent thin film 2 formed on the outer surface of the glass plate 1 as described above. The thickness of the transparent thin film 2 was 0.03 μm.

In the figure, reference numeral 21 indicates the first transparent thin film, reference numeral 22 indicates the second transparent thin film, and reference numeral 23 indicates the third transparent SS. This windshield glass was then attached to a vehicle as shown in FIG.

Next, an evaluation test was conducted on this windshield glass. Evaluation tests were conducted using a vehicle equipped with this windshield glass and a vehicle equipped with a TC-bonded windshield glass that uses the soda lime glass in the shell as it is. This was done by comparing driving in areas with a lot of volcanic ash.

(Driving during the snow-melting period) With the windshield glass of this example, the muddy water splashed up by the vehicle in front and attached to the surface while driving becomes fine water droplets that flow straight downward when the vehicle is stopped, removing dirt. It didn't stick. Furthermore, water drained well even when a wiper was used. Additionally, when the vehicle was running, wind pressure and vibrations caused muddy water to easily flow toward the rear of the vehicle, preventing dirt from sticking.

On the other hand, with conventional windshield glass, muddy water that adheres to the surface forms large droplets that stick together and are difficult to flow away. Therefore, the vehicle dries with heavy soiling, forcing frequent use of wipers and washer fluid. As a result, the full washer tank became empty within an hour of driving.

(Driving during snowfall) In the windshield glass of this example, the adhering snow was melted by the defroster device, turned into fine water droplets, and flowed straight over the surface in a short time.

Therefore, good visibility could be ensured without using the wipers.

On the other hand, with conventional windshield glass, even if the snow that adheres to the windshield is melted by the defroster device, it becomes thick (irregular water droplets) that adhere tightly to the surface and is difficult to flow away.Also, even when the vehicle is stopped, the water droplets do not flow straight down. , I had to follow an irregular path and use the wipers frequently.

(Icing condition) In the winter, after raising the indoor temperature of each vehicle under the same conditions, turn off the engine at the same time, leave each vehicle outside overnight, and remove the snow that has accumulated in the early morning to check the icy condition of each windshield glass. compared.

With the windshield glass of this example, there was very little icing on the surface, and the vehicle could be driven by simply brushing off the accumulated snow.

On the other hand, with conventional windshield glass, ice builds up irregularly on the surface, and even when the snow is removed, it remains firmly attached to the surface, making it impossible to drive until it is scraped off with a scriber.

(Driving in areas with a lot of volcanic ash) In areas with a lot of volcanic ash and other dust, it is common practice to use a broom or other play equipment to brush off the dust that has accumulated on the windshield glass, spray it with washer fluid, or use plenty of water. Then, I used the wiper to remove it.

Since the windshield glass of this example has excellent surface sliding properties, good visibility was easily obtained without dust accumulating on the windshield glass due to wind pressure and vibration during driving.

On the other hand, with conventional windshield glass, dust easily accumulates, and good visibility cannot be obtained unless it is removed by blowing or using sufficient water.

From the results of the evaluation tests in (g) below, it is clear that the windshield glass of this example does not allow muddy water, water droplets, snow, ice, or dust to stick to the surface of the windshield glass, and does not require frequent application of wiper or washer fluid. There is no need to use a scriber, broom, etc. to remove deposits. Therefore, the windshield glass manufactured in this example is
Because it has excellent sliding properties, deposits can be easily removed, and as a result, it has excellent abrasion resistance, so the surface is less likely to be damaged and good visibility can be maintained.

In addition, although the examples have been explained using a windshield glass in which a wiper is used, the functions and effects of the present invention can also be obtained when manufacturing a back window glass, a side window glass in which a wiper is not used, etc. be.

Next, in order to compare and examine the abrasion resistance between a conventional window glass in which soda lime glass is exposed as it is and a window glass manufactured by the method of the present invention, an abrasion resistance test was conducted according to the automotive safety glass test method LJISR3212>. I did it. The abrasion resistance test was carried out using - Specimen A made of soda lime glass used in the shell and Specimen B manufactured using this soda lime glass in the same manner as in the above example.
Five flat test pieces were used, and the difference between the f# value (light scattering transmittance/total transmittance) after 1000 revolutions of abrasion and the haze value before abrasion was determined. The results are shown in the table below. In addition, the haze value of both specimens △ and B before abrasion was almost 0.
．． It was 2.

From the table, sample A, which corresponds to conventional window glass, is
Because the surface is damaged + S due to wear, light is easily scattered,
It can be seen that the wear resistance is inferior. On the other hand, it can be seen that sample B, which corresponds to the window glass manufactured by the method of the present invention, has a surface that is less likely to be damaged by abrasion, so it is less likely to scatter light, and has excellent abrasion resistance.

(Left below) [Advantageous Effects of the Invention 1] The method for manufacturing a vehicle window glass of the present invention coats and bakes a siloxane polymer multiple times on one surface of a glass plate to form a transparent thin film with excellent sliding properties and abrasion resistance. As a result, it is possible to suitably remove deposits that adhere due to weather, driving conditions, etc., and to manufacture a vehicle window glass whose surface is less likely to be damaged and which can maintain good visibility.

Furthermore, in the manufacturing method of the present invention, there is no need to frequently operate the washer fluid and wipers while driving, and since light is less likely to be scattered, a vehicle windshield that provides comfortable and safe driving performance can be manufactured. can.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a vehicle windshield glass manufactured according to an embodiment of the present invention. FIG. 2 is a sectional view showing a state in which a vehicle windshield glass is attached to a ψ vehicle. 1...Glass plate 2...Transparent thin film patent applicant Toyota Motor Corporation Toyota Central Research Laboratory Co., Ltd.

Claims (1)

[Claims] (1) A method for producing a vehicle window glass, which comprises forming a transparent thin film with excellent sliding properties and wear resistance by coating and baking a siloxane-based polymer multiple times on one surface of a glass plate.