JP3889235B2 - Window for automobile and method for securing visibility of automobile using the window - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a window for an automobile having excellent water droplet fallability and a surface treatment method thereof.
[0002]
[Prior art]
Recently, the adoption of water-repellent windows for automobiles has spread, and in particular, as a higher-performance water-repellent glass, a water-sliding (sliding) window having drastically improved raindrop scattering properties has been developed.
[0003]
As an attempt to improve the water drop sliding property, a composition containing a silicone wax, an organopolysiloxane, a surfactant, etc. has been proposed based on a material that reduces the interaction (adhesion) between glass and water droplets. For example, JP-B-50-15473 discloses a composition comprising an alkylpolysiloxane and an acid, and JP-A-5-301742 discloses a composition containing an amino-modified silicone oil and a surfactant. In other words, a product that slides with a water droplet amount of about 15 μl at a 30 ° inclination is obtained. JP-A-11-181212 discloses a unit in which a group such as — (CH ₂ ) ₃ (CF ₂ ) ₇ CH ₃ is directly bonded to a silicon atom forming an organosiloxane unit, and — (CH ₂ ) _3. A surface treatment agent comprising a fluorine-containing silicone compound having a unit in which a group such as SiCl ₃ is directly bonded to a silicon atom forming an organosiloxane unit and / or a product obtained by partially hydrolyzing the compound. It is disclosed that 50 μl of water droplets slide down at an inclination of about 10 ° (the amount of water droplets required for the water droplets to slide down at 30 ° inclination corresponds to about 20 μl). JP-A-2000-144056 discloses a silicone compound having a hydrolyzable functional group at the end, or a silicone compound having a hydrolyzable functional group at the end and a fluoroalkyl group at the other end, an acid, The functional layer obtained by dissolving water in a solvent and then applying the mixed solution obtained by mixing and stirring to the substrate surface and then drying is chemically bonded to the substrate surface by a siloxane bond. A surface treatment substrate excellent in water droplet sliding property is disclosed, in which 50 μl of water droplet slides at an inclination of about 1 ° (the amount of water droplet required for water droplets to slide down at a 30 ° inclination) Is equivalent to about 5 μl). Such water-sliding (sliding) glass using a material having extremely small interaction with water droplets is expected to be applied to a front window for automobiles.
[0004]
[Problems to be solved by the invention]
However, a material having an extremely small interaction with water droplets described in the above Japanese Patent Publication No. 50-15473, Japanese Patent Laid-Open No. 5-301742, Japanese Patent Laid-Open No. 11-181212, and Japanese Patent Laid-Open No. 2000-1444056 was used. Since water slide glass has a small interaction (adhesion force) between the glass and water droplets, the adhesion force between the wiper blade (often made from natural rubber or a surface-coated material) and water droplets is low. If the raindrops on the window surface are wiped by sliding the wiper, the raindrops wiped off and wiped off the glass surface will remain on the glass surface of the reversal part. Without being attached to the wiper blade, it may return to the center of the window glass while dragging back (raindrop return phenomenon). A state, was not preferable in terms of ensuring good visibility in the rain.
[0005]
[Means for Solving the Problems]
The present invention has been made in view of these conventional problems, and when water droplets adhering to the surface of a window for an automobile are wiped by sliding the wiper, the water droplets collected on the reversing portion of the wiper are directly in the reversing portion. This invention relates to an automobile window that remains on the surface of the window glass and that does not return while being dragged to the center of the window surface while adhering to the wiper blade when the wiper reverses and slides again, and a surface treatment method thereof .
[0006]
Silanol in a window for an automobile in which a surface treatment agent having a lubricant agent for sliding water droplets attached to the glass surface is coated on the glass surface, and the glass surface is slid by a wiper to wipe off the attached water droplets. A water-sliding agent component selected from a hybrid composition comprising a terminal silicone and a silica sol as a matrix, a copolymer of a fluoroalkylsilane and a silanol-terminated polydimethylsiloxane, or a hybrid composition comprising the copolymer and a silica sol as a matrix Water droplet sliding off at the reversal part of the sliding portion of the wiper by cutting the Si—C bond or the C—C bond of the coating formed by fixing the glass on the glass substrate and partially degrading the coating. sex, reduce than other sliding parts, gas at the inverting portions of water droplet sliding property is reduced Adhesion between the scan and water droplets, characterized in that allowed greater than the adhesive force between the wiper blade and the water droplets.
[0007]
Furthermore, in the automobile window of the present invention, it is preferable that a coating formed by immobilizing the lubricant agent component on the glass substrate is formed on the outer surface of the window.
[0008]
And the method for securing the field of view of the automobile according to the present invention is a method for securing the field of view of the automobile in the rain using the automobile window according to any one of the above, and reversing the wiper by sliding the wiper It remains in the part.
[0009]
Further, according to the method of securing the field of view of the automobile of the present invention, two wipers are attached on the driver side and the assist side, and the wiper reversing portion for reducing the water drop sliding property is provided on the driver side on the upper reversing portion and the lower reversing portion. It is preferable to use the lower inversion part on the side.
[0010]
The automotive window surface treatment method according to any one of claims 1 to 3, wherein the automotive window surface treatment method of the present invention is performed by the following steps. (1) A step of coating a surface treatment agent having a lubricant agent for sliding water droplets adhering to the glass surface of an automobile window to form a water-slidable coating , (2) In the reversing portion of the sliding portion of the wiper The process of deteriorating the coating by exposing the water-sliding coating to corona discharge or plasma .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the automobile window of the present invention, a surface treatment agent for sliding off water droplets attached to the glass surface is coated on the glass surface, and the glass surface is slid by a wiper attached to the glass to wipe off the attached water droplets. In the automobile window thus formed, the water drop sliding property at the reversal portion of the sliding portion of the wiper is reduced as compared with other sliding portions.
[0012]
As the surface treatment agent for coating the glass surface, for example, a water-sliding agent or a water-repellent agent can be used. The lubricant is not particularly limited. For example, a hybrid composition comprising a silanol-terminated silicone as a lubricant component and a silica sol as a matrix, a copolymer of fluoroalkyltrichlorosilane and silanol-terminated polydimethylsiloxane. (A) silica sol obtained by hydrolysis and polycondensation of alkoxysilane, (b) mixed sol consisting of silanol-terminated dimethyl silicone and (c) organotrialkoxysilane, and also disclosed in Japanese Patent Publication No. 50-15473 A composition comprising an alkylpolysiloxane and an acid, a composition containing an amino-modified silicone oil and a surfactant as disclosed in JP-A-5-301742, and disclosed in JP-A-11-181212 such as - (CH _{2) 3} ( F _{2) 7} CH _3, etc. units groups are bonded directly to the silicon atoms forming the organosiloxane units, and, - (CH ₂₎ groups, such as ₃ SiCl ₃ were bonded directly to the silicon atoms forming the organosiloxane units It is possible to use a fluorine-containing silicone compound having an essential unit and / or a partial hydrolyzate product of the compound. In particular, a hybrid composition comprising a silanol-terminated silicone as a lubricant agent and a silica sol as a matrix, a copolymer of fluoroalkylsilane and silanol-terminated polydimethylsiloxane, and a silica sol as the matrix and the matrix In the hybrid composition and the like, since the dispersibility of the lubricant agent and the silica matrix is high, the lubricant agent having a good water droplet sliding property can be firmly fixed on the glass substrate, and the It is possible and preferable to form a film having both aqueous and durability properties.
[0013]
The water drop sliding property (sliding property) is, for example, on the surface of the sample in a state where the window glass coated with the sliding coating film is inclined at 30 °, as described in the evaluation method of the examples below. When pure water is slowly dropped with a microsyringe, the amount (volume) of water droplets at the time when the water droplets move 2 cm or more in at least 10 seconds is expressed as “μl” as a sliding property, and is a parameter representing water droplet sliding properties.
[0014]
In addition, as the water repellent, for example, a predetermined amount of a water repellent component composed of a fluoroalkyl group-containing silane compound, a solvent for dilution, and an acidic aqueous solution as a catalyst are mixed, and then stirred for a predetermined time to perform a hydrolysis reaction. It can be obtained by terminating, then adding a dehydrating agent to the solution, performing a dehydration treatment for a predetermined time, and performing polycondensation.
[0015]
Examples of the starting material include a fluoroalkylalkoxysilane compound or a fluoroalkylhalogenated silane compound as a water repellent component. Examples of the compound include CF ₃ (CF ₂ ) ₁₁ CH ₂ CH ₂ Si (OR) _3. , CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ Si (OR) ₃ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OR) ₃ , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ Si (OR) ₃ , CF ₃ (CF ₂ ) ₁₁ CH ₂ CH ₂ SiR (OR) ₂ , CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ SiR (OR) ₂ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiR (OR) ) ₂ , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ SiR (OR) ₂ , CF ₃ CH ₂ CH ₂ SiCl ₃ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiCl ₃ , CF ₃ (CF ₂ ) _{7 CH 2 CH 2 SiRCl 2, CF} 3 (CF 2 _{9 CH 2 CH 2 SiCl 3,} CF 3 (CF 2) 9 CH 2 CH 2 SiRCl 2 , etc. can be used. In the above chemical formula, R represents CH ₃ , C ₂ H ₅ , C ₃ H ₇ .
[0016]
As the dilution solvent used above, in addition to isopropyl alcohol (hereinafter abbreviated as “i-PA”), lower alcohol solvents having 5 or less carbon atoms such as methyl alcohol and ethyl alcohol may be used. Ethers and ketones can be used in addition to alcohols, and alcohols containing isopropyl alcohol as the main component are particularly preferred as dilution solvents in the preparation of coating solutions.
[0017]
Further, the acidic aqueous solution as the catalyst uses an inorganic acid such as nitric acid, hydrochloric acid and sulfuric acid or an organic acid such as acetic acid and citric acid having a concentration of 0.01N or more, preferably about 0.1N to 13N. Can do. The water repellent component: diluting solvent: acidic aqueous solution is preferably in the range of 1: 5 to 50: 0.09 to 1.0 by weight, but is not limited to these ranges. As the dehydrating agent, silica gel, synthetic zeolite, activated alumina, or the like can be used, but is not limited thereto. In addition, the present invention is not particularly limited, for example, when polycondensation is performed after completion of hydrolysis, or when polycondensation starts in the middle of hydrolysis.
[0018]
The water repellent is not limited to the above-mentioned method, but a dimethyl silicone water repellent, a mixed water repellent of the water repellent and dimethyl silicone, and a fluororesin hybridized with a silica sol. Other methods such as forming a water film can also be used. For coatings with high water slidability, it is important to have an appropriate contact angle θ (°) and water slidability δ (μl). For example, generally when the contact angle increases, the slidability tends to decrease. θ is preferably 70 ° or more. However, the relationship between the contact angle and the water slidability does not always show such a positive correlation.
[0019]
In addition, as a method of applying a lubricant or water repellent to glass, hand coating (rubbing method), nozzle flow coating method, dipping method, spray method, river coating method, flexo method, printing method Various coating methods such as known coating means such as a flow coating method or a spin coating method, and a combination thereof can be appropriately employed.
[0020]
The conditions for applying the water repellent liquid to the surface of the glass substrate are preferably an atmospheric humidity of about 75% RH or less in order to activate the reaction between the silanol group of the water repellent component and the hydroxyl group of the substrate surface. However, it is not limited to these. It is preferable to modify the surface of the glass substrate to which the water repellent liquid is applied in advance by acid treatment because the strength of the coating film is increased.
[0021]
Next, a method for reducing the water drop sliding property at the reversal portion of the wiper sliding portion of the surface treatment agent coated on the surface of the automobile window as compared with other sliding portions will be described. As a method for reducing the water drop slidability, for example, the surface of the outer surface of the front window for an automobile is subjected to a surface treatment with the above-described water slidant or water repellent, and then the water slidability is reduced to another slidability. It is possible to carry out by partially deteriorating the film by a method such as an acid treatment, an alkali treatment, a corona discharge treatment, a plasma treatment or the like only in a region to be reduced from the moving portion. In this case, if necessary, mask the other parts with a protective film. Especially, dry methods such as corona discharge and plasma treatment do not require masking, and the processing time is short. It is effective as Alternatively, it is possible to mask the portion in advance before the surface treatment so that the surface treatment is not partially performed.
[0022]
Next, the case where corona discharge and plasma treatment are performed will be specifically described. First, a blocking member such as a masking material or a blocking plate for blocking a portion not to be removed is disposed so that only the portion where the water-slidable coating or the water-repellent coating is to be removed can be exposed to corona discharge or plasma. The shielding member may be arranged immediately above the substrate that is the object to be exposed, or may be provided in the vicinity of the discharge wire. The masking material is not particularly limited as long as it can effectively block corona and ion plasma due to discharge, and a masking material such as a plastic film can be used without removing the coating. The part can be directly covered with a masking material. It is also possible to switch the application of the voltage of the discharge wire to ON / OFF and expose the corona discharge or plasma only to the portion where the water slidable film is desired to be deteriorated .
[0023]
For the corona discharge exposure conditions (output, output frequency, output waveform, exposure time, distance to the coating, etc.), the optimum conditions can be selected as appropriate depending on the type of substrate, the quality of the functional film, the film thickness, etc. . The output of the corona discharge is 0.1 to 2.0 kW, the output frequency is 35 kHz ± 5 kHz, the output waveform is a sine wave, and the scanning speed during exposure can be adjusted as appropriate within the range of 2 to 50 mm / s. Further, the distance between the discharge electrode and the ground electrode plate needs to be about 10 mm or less, and the distance between the discharge electrode and the coating is in the range of 2 to 5 mm in consideration of the thickness of the glass, and about 2.5 mm. preferable.
[0024]
On the other hand, when plasma is exposed, the output can be 0.1 to 2.0 kW, and the scanning speed during exposure can be 2 to 50 mm / s. The distance between the discharge gun and the coating is preferably 2 to 30 mm, particularly about 8 to 10 mm. Further, the plasma jet apparatus does not require a ground electrode, and is more suitable for a two-dimensional or three-dimensional molded product such as bent glass.
[0025]
By exposing corona discharge or plasma to the surface of a functional coating made of an organic compound, for example, fluoroalkylsilane compounds (FAS) and polydimethylsiloxane in the water slidable coating have a very high energy state. These electrons and ions (corona, plasma) break the Si—C bond and C—C bond in the FAS and decompose or degrade them. At this time, it is appropriate to minimize the exposure time, and unnecessarily long treatment not only reduces productivity, but also abnormally increases the temperature of the substrate glass and generates harmful ozone. This is undesirable because the amount increases .
[0026]
The window for automobiles of the present invention is provided with a wiper. By operating the wiper in the rain, raindrops adhering to the window surface can be collected on the upside down portion of the wiper. A wiper blade made of natural rubber or a material coated with natural rubber is attached to the tip of the wiper, and water droplets adhering to the glass surface are wiped off by the wiper blade when the wiper slides and are collected on the reversing portion. .
[0027]
At this time, in an automobile window in which a surface treatment agent such as a lubricant or a water repellent is uniformly coated on the entire surface of the window, the interaction (adhesion) between the raindrop and the window surface is caused by the raindrop and the wiper blade. The raindrops, which are smaller than that and scraped by the wiper, do not remain on the wiper reversal when sliding again after the wiper is flipped, and are attached to the wiper and dragged. This is not preferable in that the raindrops reversely occur, and the forward visibility is kept better. In the present invention, the surface treatment agent is not coated on the entire surface of the window, but it is necessary to reduce the water drop sliding property at the inversion portion of the wiper sliding portion as compared with other sliding portions. Moreover, it is preferable that the water droplets scraped by the wiper slide remain on the reversing part of the wiper.
[0028]
In an automobile window to which only one wiper is attached, the water drop sliding property of the left and right (up and down in some cases) reversing portions where the wiper is reversed is reduced as compared with other sliding portions. In addition, when there are two wipers, a wiper on the driver's seat side and a wiper on the passenger's seat side, the reversing part that reduces the water drop sliding property than the other sliding parts is the upper reversing part and the bottom reversing part on the driver side. It is better that the assist side upper inversion part does not reduce the water drop sliding property from the viewpoint of ensuring a good field of view.
[0029]
The automobile window of the present invention is suitable for a front window or a rear window to which a wiper is attached, but is not particularly limited to the window of that part, and is also used for a window of another part to which a wiper is attached. be able to. Further, the window is not particularly limited to colorless or colored, and its kind or color tone, shape, etc. Further, as a bent plate glass, it can be used in various tempered glass, strength-enhanced glass, flat plate and single plate. Needless to say, it can also be used as laminated glass. Furthermore, the glass wheel inner surface may be formed with various coatings such as an ultraviolet shielding film, a heat ray shielding film, and a conductive film.
[0030]
【Example】
Next, an embodiment of the present invention will be described with reference to FIGS. However, the present invention is not limited to this embodiment.
[0031]
Example (Preparation of water treatment solution)
As shown in FIG. 1, the synovial water treatment liquid has a perfluoroalkyltrichlorosilane (CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiCl ₃ : hereinafter referred to as C8FASC) and an average polymerization degree of 10 A silanol group-terminated polydimethylsiloxane (hereinafter referred to as “N10SOL”) was used to proceed with these copolymerization reactions. FIG. 1 shows the procedure for preparing the synovial fluid and the mixing ratio (weight ratio) of each component. When mixing C8FASC, N10SOL was diluted with a non-aqueous solvent to a predetermined concentration, and then slowly added dropwise with stirring.
[0032]
[Cleaning and coupling of glass substrates]
In order to firmly fix the lubricant agent on the glass surface, it is effective not only to form a hybrid film made of silica as a matrix but also to perform a coupling treatment as follows.
[0033]
As shown in FIG. 2, the surface of the glass substrate 1 for an automobile front window was polished with a polishing liquid and a brush polisher, washed with water and dried with a washing machine. The polishing liquid used here was a suspension obtained by mixing approximately 1 wt% of an abrasive for glass, Mirake A (manufactured by Mitsui Kinzoku Kogyo Co., Ltd.) with water. Next, a 0.1N aqueous nitric acid solution was added to TEOS diluted to 1 wt% with echinene (a mixture of 90 wt% ethanol and 10 wt% isopropyl alcohol), and stirred for about 2 h at room temperature to form a coating solution. The film formation is performed by spraying with a discharge rate of 50 g / pc, and the film forming film is formed by applying a coating solution for coupling treatment to the entire surface of the outside of the glass substrate 1 on the condition that the humidity during film formation is 30% RH or less. Then it was air dried.
[0034]
[Sliding water treatment]
Next, the glass substrate 1 subjected to the coupling treatment by impregnating the above-prepared slick water treatment solution (about 10 ml) into a cotton cloth (product name: Bencott / Asahi Kasei) After hand-coating on the entire surface, heat treatment was performed at 80 ° C. for 10 minutes. Subsequently, the surplus water-sliding agent component was wiped off with a paper towel to obtain a water-sliding window 2 whose entire surface was subjected to water-sliding treatment.
[0035]
[Partial reduction method of water drop sliding property]
Next, a part of the coated film was removed using a plasma jet apparatus. A plasma head of a plasma jet apparatus (PJ-01: manufactured by COROTEC) is manually or by a robot arm on a sliding window 2 that has been subjected to water sliding treatment on the entire surface of the glass substrate 1. The region of the lower inversion portion 5 of the assist-side wiper was exposed to plasma. In addition, the upper reversal part on the assist side was not subjected to the exposure treatment.
[0036]
In this case, the exposure treatment conditions were as follows: the electrode voltage of the exposure treatment was 0.5 kW, the distance between the plasma head and the surface of the glass substrate 1 was maintained at about 10 mm, and the plasma head was moved at 5 to 100 mm / s. A voltage was applied only to the inversion portions 3, 4, and 5 to be removed. In this case, it is not necessary to apply a masking material in other areas where film removal is not performed. The processing takes about 30 seconds, and the obtained window 6 for an automobile has only the upper reversing portion 3 and the lower reversing portion 4 of the driver-side wiper and the lower reversing portion 5 of the assist-side wiper after the film is removed by plasma treatment. The water-sliding film is selectively deteriorated or removed, and other wiper sliding portions (the glass peripheral portion 9 excluding the driver side sliding portion 7, the assist side sliding portion 8, and the wiper sliding portion are covered with the coating as it is. Note that the region of the inversion portion from which the film was removed was a region having a length of about 50 cm and a width of about 3 cm.
[0037]
As a result of measuring the in-plane contact angle and water slidability of the glass surface of the automobile window 6 with partially reduced water slidability, a slid water treated part (not plasma treated, for example, wiper sliding part 7, In 8), the contact angle was 100 ° and the water sliding property was as high as 8 μl, but the water droplet sliding property was maintained. However, in the part exposed through the plasma head (for example, the inversion parts 3, 4, 5) As the angle was about 54 ° and the water slidability was about 50 μl, the water slidability was partially lowered, and it was confirmed that the slidable film was efficiently removed. In addition, evaluation was measured by the following method.
[0038]
(1) Contact angle The angle formed by the water droplet and the sample surface when about 2 μl of pure water was placed on the sample was measured with a contact angle meter. In addition, it measured in air | atmosphere (about 25 degreeC) using Kyowa Interface Science CA-X type for a contact angle meter.
[0039]
(2) Sliding water With the sample inclined at 30 °, pure water is slowly dropped onto the sample surface with a microsyringe, and the amount (volume) of water droplets at the time when the water droplets move 2 cm or more in at least 10 seconds is slid. Aqueous (μl) was used as a parameter representing water drop sliding properties. In addition, when the water slidability is 20 μl or less, a “return phenomenon of raindrops” is observed when a natural rubber wiper blade is used, and moreover, when the water slidability is 10 μl or less. A remarkable phenomenon was observed.
[0040]
Next, as a result of assembling the automobile window 6 obtained as described above on the test vehicle and performing a simulated wiper wiping test, the regions 3, 4 and 5 in the wiper reversing part are partially When the wiper is reversed, the raindrops collected by the deterioration of the water-sliding film remain on the window glass of the wiper reversal part, and do not adhere to the wiper blade and drag the raindrops. Later, good visibility was ensured.
[0041]
Comparative Example Compared with the example, all the same operations were performed as in the example except that the water-slidable coating was not removed. As a result, in the case where the entire surface was subjected to water sliding treatment, when the wiper was reversed, the raindrops collected by the scrape adhered to the wiper blade and many raindrops were pulled back to the center of the window surface.
[0042]
【The invention's effect】
The present invention relates to an automobile window in which when water droplets on the surface of an automobile window are wiped by wiper sliding, the water droplets scraped by the wiper remain in the reversing portion of the wiper. The wiped water droplets are not pulled back to the center of the window, exhibiting excellent effects such as good transparency and sufficient visibility, and safe driving.
[Brief description of the drawings]
FIG. 1 is a diagram showing a procedure for preparing a synovial fluid.
FIG. 2 is a view from the inside of a vehicle showing a front window for an automobile partially having reduced water slidability.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Sliding window 3 Driver side upper inversion part 4 Driver side lower inversion part 5 Assist side lower inversion part 6 Automotive window 7 Driver side wiper sliding part 8 Assist side wiper sliding part 9 Glass peripheral part

Claims (5)

Silanol in a window for an automobile in which a surface treatment agent having a lubricant agent for sliding water droplets attached to the glass surface is coated on the glass surface, and the glass surface is slid by a wiper to wipe off the attached water droplets. A water-sliding agent component selected from a hybrid composition comprising a terminal silicone and a silica sol as a matrix, a copolymer of a fluoroalkylsilane and a silanol-terminated polydimethylsiloxane, or a hybrid composition comprising the copolymer and a silica sol as a matrix Water droplet sliding off at the reversal part of the sliding portion of the wiper by cutting the Si—C bond or the C—C bond of the coating formed by fixing the glass on the glass substrate and partially degrading the coating. sex, reduce than other sliding parts, gas at the inverting portions of water droplet sliding property is reduced Automotive window adhesion between the scan and water droplets, characterized in that allowed greater than the adhesive force between the wiper blade and the water droplets. The window for automobiles according to claim 1, wherein a film formed by immobilizing a lubricant agent on a glass substrate is formed on an outer surface of the window . It is a method of ensuring visibility in the rain of an automobile using the automobile window according to claim 1 or 2, wherein water droplets remain in the reversing part of the wiper by sliding of the wiper blade. To ensure the visibility of your car . The two wipers are attached to the driver side and the assist side, and the wiper reversing portion for reducing the water drop sliding property is an upper reversing portion and a lower reversing portion on the driver side, and a lower reversing portion on the assist side. 3. A method for securing the field of view of a vehicle in rainy weather according to 3 . The surface treatment method for an automobile window according to claim 1, wherein the treatment is performed by the following steps. (1) A step of coating a surface treatment agent having a lubricant agent for sliding water droplets adhering to the glass surface of an automobile window to form a water-slidable coating , (2) In the reversing portion of the sliding portion of the wiper The process of deteriorating the coating by exposing the water-sliding coating to corona discharge or plasma .

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