KR20130132181A - Compositions of silicone rubber for wiper blade - Google Patents

Abstract

The present invention relates to a coating composition applied to a silicon rubber wiper of an automobile and, more specifically, to a coating composition which is manufactured by adding a silicon binder, an additive, a solid lubricant, and a curing agent. The coating composition provides improved abrasion resistance, prevents chattering and noise, and maintains water repellency.

Description

≪ Desc / Clms Page number 1 > Composite of Silicone Rubber for Wiper Blade &

The present invention relates to a lubricating coating composition for application to a silicone rubber wiper used in automobiles.

Conventionally, a wiper blade used for cleaning an automobile glass surface is made of a rubber material. In general, a rubber composed of natural rubber and chloroprene rubber alone or in combination is used for surface treatment or lubricating coating for the purpose of reducing the friction coefficient Respectively.

For example, Japanese Unexamined Patent Publication No. 55-113545 discloses an attempt to improve the abrasion resistance by reducing the frictional coefficient of the rubber surface by modifying the surface by halogenating the surface of the rubber blade. However, due to the problem of surface hardening, Resulting in deterioration of the scrubbing performance with the passage of time. Accordingly, in order to solve the above problems, the inventors of the present invention have proposed a vinylidene fluoride hexafluoropropylene modified resin obtained by modifying a binder with a cellulose compound in Korean Patent Registration No. 10-0368172 and using an aminosilane compound as a curing agent Discloses a technique relating to a lubricant coating composition for a wiper blade that improves abrasion resistance and durability.

The inventors of the present invention have also found that, in order to reduce chattering and noise generation due to an increase in friction coefficient due to the formation of a water film due to hydrophobicity in a water-repellent automobile glass which is not a hydrophilic general glass, Patent Document No. 10-0403283 discloses a silicone rubber powder Discloses a technique relating to a wiper blade lubricating coating composition for a water-repellent coating glass which can improve chattering, noise, and durability by mixing silicone resin powder. The coating composition exhibits excellent properties in wiper blades made of common rubber such as natural rubber and chloroprene rubber. In recent years, however, silicon wipers made of silicone rubber with silicone oil added to dramatically improve the driver's visibility and can easily form water-repellent glass by operating only the wiper through the oil bleed of the rubber itself, have inherent inert and non- There is a problem in that it is not fundamentally adhered to the silicone rubber having the characteristics. Accordingly, Japanese Patent Application Laid-Open No. 2000-118361 discloses a water-repellent wiper blade capable of forming a water-repellent glass on a glass surface through an oil bleed by adding silicone oil to silicone rubber, and a silicone rubber excellent in heat resistance, chemical resistance, Discloses a technique of forming a water-repellent glass through an oil bleed of a silicone oil and using a fluororubber solution and a fluororesin solution as a binder of a lubricating coating composition on a silicone rubber surface. However, the fluorine rubber and the fluorine resin used as the lubricant coating binder of the above technique are effective for preventing chattering and preventing noise in the early stage by utilizing the low friction coefficient of the fluorine compound, but sufficient adhesive force can be obtained due to the difference in surface characteristics with silicone rubber There is a problem that the durability is drastically reduced in long-term use.

In addition, Korean Patent Registration No. 10-1006778 discloses a water-repellent coating composition for a water-repellent wiper blade applicable to a natural rubber surface, which is a rubber, using a polyester polyol and a urethane binder using a diisocyanate as a curing agent, The present invention is directed to a technique of using a silicone oil capable of improving the durability of a water-repellent film and a silicone oil capable of improving the durability of a water-repellent film. However, The silicone oil and wax must be added only to the coating film. Therefore, it is difficult to restore the water-repellent film formed on the glass surface, thereby causing durability problems. In addition, since the binder of the coating composition is basically not bonded to the silicone rubber, there is a problem that it is limited to the application of natural rubber.

Accordingly, the present inventors intend to provide a lubricating coating composition which has excellent abrasion resistance and does not generate chattering and noise even during long-term use. In order to solve such problems, the present invention uses a silicone rubber and a silicone resin as a binder , And a platinum catalyst is used as a curing agent. The present invention also provides a coating composition for a silicone rubber wiper blade.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention, claims and drawings.

According to one aspect of the present invention, there is provided a coating composition for a wiper blade comprising an organic solvent, a silicone binder, a solid lubricant and an additive.

According to another aspect of the present invention, there is provided a silicone rubber for a wiper blade coated with a coating composition for a wiper blade.

The features and advantages of the present invention are as follows.

(i) The present invention relates to a coating composition for coating on a silicone rubber sheath of an automobile wiper blade.

(ii) When the wiper blade coating composition of the present invention is used, it has excellent adhesiveness, excellent abrasion resistance, water repellency, and excellent noise and chattering effect.

(iii) When the wiper blade coated with the composition of the present invention is used, the water repellent film formed on the automobile glass surface can be restored constantly, which is advantageous in durability.

Hereinafter, a method of manufacturing a sound absorbing material according to a preferred embodiment of the present invention with reference to the accompanying drawings will be described in detail.

According to one aspect of the present invention,

It provides a coating composition for a wiper blade comprising a silicone binder, a solid lubricant and an additive in an organic solvent.

The composition ratio of each composition is characterized by being composed of a composition as described below.

Organic solvent 70 - 80 wt%

Silicone binder 3 -10 wt%

Solid lubricant 10 - 15 wt%

Additive 3 -10 wt%

The silicone binder used in the present invention is characterized by mixing a silicone rubber and a silicone resin, and is characterized in that a silicone resin having flexibility and excellent adhesiveness is mixed with a silicone resin for the purpose of improving rigidity and abrasion resistance.

As the silicone rubber which can be used in the present invention, dimethyl silicone rubber, methyl vinyl silicone rubber, methylphenyl silicone rubber, methylhydrogen silicone rubber and the like can be used, and among them, methyl vinyl silicone rubber is the most preferable.

The average degree of polymerization of the methylvinyl silicone rubber that can be used as the binder is preferably about 1,000 to 20,000, more preferably about 7,000 to 8,000.

The vinyl group content is preferably in the range of 0.05 to 1.0 mol%, more preferably in the range of 0.35 to 1.0 mol% as the binder. When a methyl vinyl silicone rubber having a low vinyl group content is used, a desired performance can not be obtained due to a low crosslinking density. On the other hand, when methyl vinyl silicone rubber having a higher vinyl group content than necessary is used, Can fall.

On the other hand, the silicone resin to be mixed with the silicone rubber is characterized by a resin containing a vinyl group at both terminals of a polydimethylsiloxane and a hydrogensilane. When cured with a platinum catalyst, an addition reaction is caused to form a three-dimensional network structure A hard film can be obtained.

The degree of polymerization of the silicone resin is preferably about 50 to 200,000, more preferably 1,000 to 100,000.

The silicone resin used in the present invention can be cured by an addition reaction, a condensation reaction and an ultraviolet irradiation method. Among them, a method of inducing an addition reaction using a platinum catalyst is advantageous for co-crosslinking together with silicone rubber.

In addition, the silicone resin may be mixed alone, and in some cases, a silicone modified resin grafted to a silicone resin such as a silicone-modified urethane resin or a silicone-modified epoxy resin, a fluorine rubber, or a fluorine resin may be used.

The mixing ratio of the silicone rubber and the silicone resin is preferably 1: 0.1 to 1: 1, more preferably 1: 0.33 to 1: 1. If the mixing amount of the silicone resin is small, the coating is weak and the abrasion resistance is poor. On the other hand, if the mixing amount of the silicone resin is excessively large, the coating becomes too hard and is susceptible to bending resistance and tends to cause brittle fracture.

In the present invention, one or more of the above-mentioned solid lubricants may be used in combination. It is preferable to use a solid lubricant having an average particle size in the range of 1 탆 to 15 탆 and an average particle size of 3 탆 to 6 Mu] m is more preferably used.

The content of the solid lubricant used can be mixed with the binder in the ratio of 1: 9 to 5: 5 by weight. When the solid lubricant content is high, the introduction property is lacking. When the solid lubricant content is low, To increase effective lubricity can not be obtained.

Also, in the present invention, silicone rubber powder and silicone resin powder, which are effective for chattering, noise reduction, and abrasion resistance improvement in water-repellent glass, can be used as an additive. Smooth, flexible and smooth Silicone rubber powder and siloxane bonds, which are effective in chattering stability, are spread in three dimensions. A smooth, very hard and durable silicone resin powder with a methylene group at the end is used as an additive.

The combined total content of the silicone rubber powder and the silicone resin powder used as the additive was set to 30 to 70 parts by weight based on the total weight of the coating containing volatile components.

In the coating composition, a curing agent is used for curing the binder, and a platinum catalyst, a peroxide, and a silane coupling agent may be used as the curing agent that can be used. Examples of the peroxide include benzoyl peroxide, dicumyl peroxide, Butyl peroxide, dimethylbisbutylperoxyhexane, t-butylcumyl peroxide, paramethylbenzoyl peroxide, vinyl silane coupling agents such as vinyltrimethoxysilane and vinyltriethoxysilane may be used alone as the silane coupling agent Or may be used in combination.

In the case of using a peroxide as a curing agent, there is a problem in surface hardening of the coating layer, and in the case of using a silane coupling agent, a platinum catalyst having a good reactivity and a good adhesion and durability, As a curing agent.

The addition reaction mechanism using the above-mentioned platinum catalyst is shown below.

The platinum catalyst used as a curing agent in the present invention is preferably used in an amount of 1 to 2% by weight based on the weight of the mixed binder,

When the binder is used in an amount of less than 1% by weight, hardening of the binder does not progress sufficiently and desired performance can not be obtained. When the binder is added in an amount of 2% by weight or more, the resulting coating may become hard and brittle.

The coating composition having the above composition may be used alone or as a mixture of solid lubricants such as graphite, polytetrafluoroethylene, molybdenum disulfide, and tungsten disulfide having an average particle size of 1 탆 to 15 탆, and usually 3 Mu m to 6 mu m is mainly used.

Further, an organic solvent for dissolving the silicone rubber and the silicone resin may be used. In the present invention, solid lubricants including silicon rubber and silicone resin are dissolved in organic solvents before use.

Examples of the organic solvent that can be used include toluene, benzene, xylene, methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl acetate, butyl acetate, cellulose acetate, ethyl cellosolve, butyl cellosolve, Or an amount of the organic solvent is not particularly limited, but is usually used in the range of 75 to 90% by weight of the coating composition.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood that the scope of the present invention is not limited by these examples in accordance with the gist of the present invention, and it is to be understood by those skilled in the art that the present invention is not limited thereto It will be obvious.

1. Manufacturing and Example

(One) Manufacturing example  1: Wiper rubber Blade's  making

Silicone rubber was prepared by adding 100 parts by weight of a reinforcing agent, a silicone oil, a heat resistance improver, a pigment and a peroxide to prepare a wiper rubber blade to be coated with the coating composition, as shown in Table 1 below.

The silicone rubber was blended as shown in Table 1, molded by press vulcanization at 170 ° C for 10 minutes, and then vulcanized at 200 ° C for 4 hours to prepare a wiper blade molded article.

(2) Example  1-7: Wiper rubber On blade  The lubricating coating composition to be coated

Table 1 < tb >< tb >< tb > First, the silicone rubber and the silicone resin were dissolved in toluene and methyl ethyl ketone, which were organic solvents, and then the solid lubricant and the additives were mixed in a container and dispersed using a stirrer to prepare a subject as shown in Table 2. The curing agent was added to the topcoat immediately before coating the silicone rubber molded wiper blade, and the coated product was thermally cured at 135 ° C for 5 minutes to form a coating. In Examples 1 to 7, a coating composition was synthesized by differently mixing the silicone rubber and the silicone resin constituting the binder.

Table 3 below shows the use of a platinum catalyst for forming a hard coating through induction of addition reaction by a heat curing treatment of a coating film with a curing agent for co-crosslinking a silicone rubber and a silicone resin, which are coating binders of Table 2.

(3) Comparative Example  1-2: Composition using a silicone rubber or silicone resin alone as a coating binder

Comparative Example 1-2 was used as a silicon binder formed by adding a silicone rubber or a silicone resin alone to prepare a coating composition for lubricating, and the procedure was the same as that of Example 1-7.

2. Experimental results

(1) Abrasion resistance test

The wiper blade rubber specimens were cut at intervals of 50 mm and fixed to the abrasion test equipment (manufactured by KCW), and abrasion marks were observed and evaluated after 30,000 reciprocating operations in the dry state on the flat glass surface. The environment set on the wear test equipment is as follows.

Pressing pressure: 15 g / cm

Travel distance: 100 mm

Evaluation method: ○ Almost no abrasion, △ 10% abrasion, × 50% abrasion,

In Table 4, three tests were performed for the example and the comparative example, respectively, and the initial performance and the post-durability performance (after 100,000 operation) were measured as numerical values.

(2) water repellency evaluation

The initial water repellency was evaluated by visually observing the water-repellent film remaining on the glass surface after spraying the water after operating the wiper blade for 5 minutes in a dry state on the surface of the automobile glass and visually observing the water- Based on the judgment criteria described above.

(3) Chattering (Tremor) evaluation

The wiper blades produced according to the above-described Examples and Comparative Examples were operated to observe the chattering on the basis of the criteria shown in Table 6 below. The higher the score, the better the chattering stability.

(4) Noise evaluation

The wiper blades produced according to the above-described Examples and Comparative Examples were operated to visually observe and evaluate the noise according to the criteria shown in Table 7 below. The higher the score, the better the prevention of noise.

It was confirmed that the best results were obtained in the water repellency, chattering degree and noise evaluation test using the wiper blade coated with the coating composition prepared in Example 3 and Example 4. (Table 4)

Claims (17)

Coating composition for wiper blades comprising an organic solvent, a silicone binder, a solid lubricant and additives.
70-80 wt% of organic solvent
Silicone binder 3 -10 wt%
Solid lubricant 10 -15 wt%
Coating composition for wiper blades comprising additive 3-10% by weight.
The method according to claim 2, wherein the organic solvent is a single organic solvent selected from the group consisting of toluene, methyl ethyl ketone, benzene, xylene, acetone, methyl isobutyl ketone, ethyl acetate, cellulose acetate, ethyl cellosolve, and butyl cellosolve; Wherein the organic solvent is a mixture of two or more solvents.
The composition of claim 2, wherein the silicone binder comprises a silicone rubber and a silicone resin.
The composition of claim 4, wherein the silicone rubber is a single or two or more rubber mixtures selected from the group consisting of dimethyl silicone rubber, methylvinyl silicone rubber, methylphenyl silicone rubber, and methylhydrogen silicone rubber.
The composition according to claim 4, wherein the silicone resin is used alone or in combination of polydimethyl siloxane resin and hydrogen silane.
[7] The method of claim 6, wherein the silicone resin is selected from the group consisting of a polydimethylsiloxane resin and a hydrogen-modified silane-modified urethane resin, a silicon-modified epoxy resin, ≪ / RTI > wherein said composition is additionally added.
The composition according to claim 4, wherein the silicone rubber is a rubber having an average degree of polymerization of 1,000 to 20,000.
The composition according to claim 4, wherein the vinyl group content contained in the silicone rubber is 0.05-1.0 mol% relative to the total silicone rubber.
The composition of claim 4, wherein the silicone resin has an average degree of polymerization of 50 to 200,000.
The composition according to claim 4, wherein the silicone rubber and silicone resin constituting the silicone binder are co-crosslinked.
12. The composition of claim 11, wherein the co-crosslinking is formed using a platinum catalyst, peroxide or silane coupling agent.
The composition of claim 4, wherein the mixing ratio of the silicone rubber and the silicone resin is 1: 0.1 to 1: 1 by weight.
The composition of claim 2, wherein the solid lubricant is a single or two or more solid lubricant mixtures selected from the group consisting of graphite, polytetrafluoroethylene, molybdenum disulfide, tungsten disulfide and boron nitride.
15. The composition according to claim 14, wherein the solid lubricant has an average particle size of from 1 to 15 mu m.
The composition of claim 2 wherein the additive is silicone rubber powder, silicone resin powder or a mixture of silicone rubber powder and silicone resin powder.
Silicone rubber for wiper blades coated with the coating composition of any one of claims 1 to 16.