KR100988533B1 - Composition for coating a rubber of wiper blade, its coating method and a rubber for wiper blade prepared from the method - Google Patents

Abstract

The present invention relates to a composition and a coating method thereof for coating (painting) such rubber to improve the durability and resistance to friction of the rubber for wiper blades. This coating composition is for coating rubber for wiper blades, and is used in nanometer size PTFE (Teflon), polyurethane, silicone resin, graphite, tungsten, molybdenum, carbon lubricants and water-soluble resins, distilled water and paints used as solvents. It consists of additives used.

Wiper blade, wiper strip, teflon, urethane, silicone resin, water soluble resin, graphite, molybdenum, carbon, distilled water

Description

Composition for coating a rubber of wiper blade, its coating method and a rubber for wiper blade prepared from the method}

The present invention relates to a coating composition of rubber for wiper blades, and more particularly to a nanometer size composition for coating on rubber for wiper blades, to improve the durability and resistance to friction, the coating method and such a method It relates to a manufactured rubber for wiper blades.

In a typical car, a wiper strip rubber coupled to a wiper blade is driven by the wiper arm of the vehicle. The wiper strip rubber turns left and right on the glass surface of the vehicle while removing foreign substances such as rain, snow, and dust to secure the driver's view. Since the portion of the wiper blades in contact with the glass surface is strip-shaped, it is called a strip rubber for the wiper blade, and it is also abbreviated as a rubber for the wiper blade or a rubber for the wiper, and thus it will be used interchangeably here.

The wiper rubber used in combination with the frame of the wiper blade is composed of an elastic material, and the wiper rubber is a wiper blade wedge contacting the glass surface of the vehicle and the head part which is coupled to the frame of the wiper blade. Divided. These wiper heads and wedges are assembled together to fold in the opposite direction to the glass cleaning direction by the frictional force generated between the glass and the wiper rubber when cleaning the vehicle glass, so that the wiper rubber is uniform and as slip-free as possible Maintain functionality.

The material of such a wiper blade rubber requires complex requirements relating to its mechanical properties as well as its stability against external influences. The rubber material for the wiper must be flexible and able to slide smoothly over the vehicle windshield, and against external influences, in particular oxides (ozone decomposes), mineral oils and also chemicals contained in eg cleaning liquids. It must be durable.

Rubber materials for wipers are generally rubber, ie vulcanized natural rubber or synthetic rubber, but in order to improve the sliding properties of the rubber, for example, the surface of the rubber for wipers is coated, chlorinated or coated with a lubricating powder such as molybdenum sulfide Has been proposed.

The rubber for wipers specified in DE-C-35 27 093 consists mainly of ethylene propylene diene monomer (EPDM), but in the case of EPDM the unsaturated position lies outside the polymer ring. Thus, EPDM was not halogenated, and EPDM was also not resistant to chemicals contained in petroleum and cleaning liquids. In order to improve the sliding properties and durability of the rubber for wipers, which consists mostly of EPDM, chlorinated diene-types in a matrix composed of EPDM, at least in the area that slides on the surface of the glass window, in accordance with DE-C-35 27 093. The rubber piece is placed. Such a wiper rubber has the disadvantage of having a relatively complicated structure of different rubber material layers.

On the other hand, International Publication No. WO 1999/39948 (corresponding to Korean Patent Laid-Open Publication No. 10-2001-0015914) discloses a form in which the head and wedge materials of the wiper rubber are separated from each other. Here, the head portion of the diene-type rubber can be halogenated, so that the sliding property is good, the wiper blade is easily accessible to the region interlocking with the support strip and the metal support spring rail, and the surface is more firm. In addition, chloroprene (CR) rubber is used for the conversion bridges and wedges of the wiper blades, which combines excellent mechanical properties with high durability against bad weather, aging, chemicals and the effects of temperature. Good cleaning power could be achieved in an economical way. The chloroprene has high durability against bad weather, aging, chemicals, temperature, and the like, but has been limited in resistance to frictional force generated between the glass and the rubber for wipers.

Meanwhile, Korean Patent Publication No. 10-2005-006677 discloses a wiper blade coating composition and a coating method thereof. The coating composition used herein includes a resin selected from a polyol resin, a urethane resin, a hydroxyl-containing fluorine resin, an epoxy resin, and a silicone resin in the presence of a solvent having graphite and dimethyl sulcon oil as essential components. When the wiper blade coated with the coating composition is operated in a vehicle, it is possible to form a durable water repellent coating on the windshield of the vehicle, and to prevent the occurrence of noise and tremor of the wiper blade. However, the solvent used in the prior invention is selected from organic solvents such as methyl ethyl ketone, toluene, xylene and butyl acetate, and there is a problem causing environmental pollution because the resin used is not limited to a water-soluble resin. .

The present invention is to provide an environment-friendly Teflon coating composition for coating on the rubber for wipers for improving the resistance to friction while having a high durability against adverse weather, chemicals and temperature. In addition, the particles of the coating composition of the present invention has a coating effect is superior to the coating composition described in the Korean Patent Publication No. 10-2005-006677 by coating using nanoparticles of smaller particles than the conventional one and a long-term water repellent performance It is to provide a coating composition that can sustain.

An object of the present invention is a composition for coating the rubber for wiper blades, in the presence of a solvent, 3.5 to 15% by weight of Teflon, 3.2 to 9.6% by weight of urethane resin, 1.6 to 6.0% by weight of silicone resin, 5.0 to These components, Teflon, urethane resins, silicone resins and water-soluble resins, are all achieved by coating compositions containing 50 to 500 nanometers, while containing 25.0% by weight of water-soluble resins, and it is particularly preferable to use distilled water as a solvent. .

As an aspect of the present invention, the coating composition of the present invention may comprise 0.16 to 0.24% by weight of silver, or 3.5 to 15% by weight of graphite (graphite) or carbon black, or both of these silver and graphite These components can all be used in sizes of 50 to 500 nanometers.

The rubber used in the present invention may be a general rubber, that is, a vulcanized natural rubber or a synthetic rubber, but is preferably a diene-type-rubber or chloroprene rubber exemplified in the above-mentioned prior art. In particular, the diene-type-rubber is more preferably natural rubber or butadiene rubber, styrene-butadiene rubber, EPDM (Ethylene Propylene Diene Monomer) rubber, silicone rubber may be used if necessary.

On the other hand, the object of the present invention is further achieved by a method for coating the rubber for the wiper blade with the coating composition as described above and a wiper blade manufactured therefrom. In particular, such a coating is a secondary coating after the first coating with an intermediate medium in order to improve water repellency and durability. At the time of secondary coating, it is preferable to preheat it to a temperature which can expand the surface of the used rubber and to apply the spray method in the expanded state of the rubber.

Teflon, which is used as a core component in the present invention, is a trade name of a representative polytetrafluoroethylene (PTFE) among fluoropolymers, which is a crystalline resin, which is heat resistant to long-term use at 260 ° C, and has chemical resistance, electrical insulation, non-adhesiveness, Low friction coefficients are known as unusual synthetic resins. In particular, the PTFE is a crystalline polymer having a melting point of 327 ° C, and the continuous use temperature is 260 ° C, and it is known that it can be used stably from low temperature (-268 ° C) to high temperature.

In addition, Teflon's chemical resistance is best known among organic materials. In particular, Teflon is not deformed at all in acid, alkali, and various solvents, and is only deformed under severe conditions in special chemicals such as fluorine gas and molten alkali metal. It is used for etc. In addition, the greatest characteristic in mechanical properties is that the friction coefficient is small and is reinforced with various fillers, and the non-adhesive property is also known as the best synthetic resin for coating of frying pans and various steel pipes.

According to the present invention, when wiper rubber is coated with a composition containing Teflon by using the physical, chemical and mechanical properties of Teflon, the rubber for wiper gives high durability against such bad weather, aging, chemicals and temperature effects. The present invention has been completed in view of the fact that the resistance to frictional force generated between the glass and the rubber for wipers can be improved.

Such teflon can be used in the coating composition in the range of 3.5 to 15% by weight based on the total weight of the composition, outside of this range can not achieve the desired coating effect, the preferred component ratio is 7 to 8% by weight.

Polyurethane used in the present invention is a synthetic high molecular compound produced by a polyaddition reaction of diisocyanate and dialcohol repeating the urethane bond, having a urethane bond in the main chain, any commercially available water-soluble polyurethane Can be used.

Such urethane resins can be used in the coating composition in the range of 3.2 to 9.6 wt% based on the total weight of the composition, outside the range can not achieve the desired coating effect, the preferred component ratio is 5 to 7 wt% .

The silicone resin used in the present invention is also referred to as silicon resin as a polymer of an organic derivative of silicone. Its molecular structure is a thermoplastic synthetic resin in which silicon is in the form of a siloxane bond (Si-O bond) in which silicon and oxygen are alternated, and methyl, phenyl, and hydroxy groups are added to silicon. Such silicone resins have a great effect of removing bubbles from most solvents, and in particular, they are used in the composition of the present invention because they have water repellency in water or inorganic substances. As the silicone resin used in the present invention, any commercially available silicone resin can be used.

Such a silicone resin may be used in the coating composition, in the range of 1.6 to 6.0 wt% based on the total weight of the composition, and when the silicone resin is used in an amount of 6 wt% or more, a white film may appear on the glass surface, thereby achieving the object to be developed. The same is true when the weight is less than 1.6 wt%. Preferred component ratios are from 2 to 3% by weight.

On the other hand, a silicone resin is used to enhance the water repellency of the coating composition of the present invention, but in addition to such water repellency, commercially available water soluble resin (water soluble resin) in order to give the other physical and chemical properties required for the wiper blade. If it can be added to a thermosetting water-soluble resin, a urethane resin is especially preferable.

Such water-soluble resins can be used in the coating composition in the range of 5 to 25% by weight based on the total weight of the composition, outside of this range can not achieve the desired effect of the invention, the preferred component ratio is in the range of about 20% by weight Mine

In addition, commercially available graphite or carbon black may be added to the coating composition of the present invention in order to give the coating composition of the present invention not only good mechanical properties but also high durability against external influences.

In addition, silver (silver) is known to enhance the chemical properties in addition to antimicrobial, sterilization, increase durability, the properties of the silver can be used in the present invention because it is necessary in the wiper blade of the present invention. Such silver may be used in the coating composition in a small amount, so that it may be used in the range of 0.16 to 0.5% by weight based on the total weight of the composition, and beyond this range, the desired effect may not be achieved or the economy may be inferior.

In the present invention, the addition of graphite or carbon black in addition to the silicone resin means that the silicone component in the coated wiper blade rubber transfers the water-repellent component to the automobile glass while moving left and right by the wiper first so that the glass has a water-repellent function. do. However, the water-repellent component is to produce a coating composition by adding a graphite or carbon black to reduce the friction coefficient in order to prevent noise or tremor during wiping of the wiper to increase the friction coefficient. Such graphite or carbon black components may be used in the coating composition in the range of 3.5 to 15% by weight, based on the total weight of the composition, outside of this range may not achieve the desired effect or may be less economical.

The coating composition of the present invention may further include additives for coating functions such as stabilizers, desiccants, thickeners, antifoaming agents, as well as dispersants having a role of making the composition or actively helping the composition to dry well. These dispersants and additives are sufficient in small amounts and can therefore be used in the range of 0.5% by weight, respectively, based on the total weight of the composition.

Finally, although various organic solvents can be used as the solvent for preparing the coating liquid composition, since the organic solvent generates environmental pollutants, it is preferable to use water, which is environmentally friendly distilled water. However, if distilled water alone cannot sufficiently dissolve each of the above components in a short time, a mixture of a small amount of lacquer thinner and distilled water may be used. The lacquer thinner used in the present invention is generally used as a mixed solvent used for lowering the viscosity of a paint during coating and can be easily purchased on the market.

Particles of the coating composition of the present application is to be coated using small particles in nanometers smaller than the conventional one, in order to prepare such a nanometer particle coating composition, each component used is 50 to 500 nanometer fine particles Prepared by dissolving in distilled water as a solvent to prepare a coating composition. It is preferable to use a product of about 300 nanometers or less for the Teflon component, and to use a size of about 400 nanometers for the remaining components.

The process of coating by the nanometer size composition is preheated at 60 to 100 ℃ to spray the coating composition in the state of expanding the surface of the rubber. The preheating temperature varies depending on the nature of the rubber, but generally 80 ° C. is suitable as the temperature at which the surface of the used rubber can be expanded. Unlike the conventional coating method, the preheating process sprays using a nanometer material, so that the coating component penetrates into the rubber surface as well as the coating on the rubber surface. Therefore, the coating composition of the present invention has an advantage of excellent coating effect than the conventional coating composition and can maintain a water-repellent performance for a long time.

The rubber for the wiper blades according to the present invention can be produced by conventional methods, but it is advantageous to produce by coextrusion of diene-elastic rubber and chloroprene-elastic rubber as described in the above-mentioned prior document, In this case, first, an unvulcanized strip of the specified cross-sectional shape is produced. It is then preferable to vulcanize the rubber for the wiper blades, if necessary, such as hypochlorite or trichlorocyanic acid.

In the coating composition of the present invention, since both graphite (graphite) or carbon black and silicon components are included, a coating method capable of achieving a dual effect such as performing a graphite coating with a coating at a time and then applying a silicon coating, and Since the adhesive strength is weak due to the component, and there is a problem in durability, there is a method of coating the top coat after the primer (pretreatment) treatment.

Since the Teflon-coated wiper blade of the present invention is excellent in wiping performance (wiper operating performance) and also has a low coefficient of friction, less noise is generated by the wiper and less chattering is caused by the wiper. Could be. In order to more specifically confirm this effect, the coating composition obtained in the following examples will be examined in the wiping performance test, the water repellent coating test, and the friction test.

Hereinafter, a coating composition will be prepared with reference to specific examples, and then the coating process will be described briefly.

Example 1

To the distilled water used as a solvent, 25% by weight of Teflon, 25% by weight of urethane resin, 1% by weight of silicone resin, 1% by weight of carbon black, and 2% by weight of silver are added the remaining weight% of the paint additive. At 300 nanometers in size, the remaining components were made into fine particles of about 400 nanometers in size to create a nanometer-sized coating liquid composition.

1 is a cross-sectional view of a conventional wiper rubber in which a head portion 13 having an inner elastic rail 10 and a wedge portion 15 in contact with a vehicle glass surface are coupled through a switching bridge 17. On the other hand, Figure 2 is weakly connected to the connecting portion 40 while the two rubber for the wiper is integrally integrated with the head portion 33 having an outer elastic rail 30 and the wedge portion 35 in contact with the vehicle glass surface. The cross section of the rubber for two wipers according to the invention in form.

In the present invention, the conventional wiper rubber of the form of Figure 1 may be coated with the coating composition prepared above. Although not shown, of course, the case of the wiper strip for a conventional wiper blade is coupled or integrally coupled to the head portion having an outer elastic rail and the wedge portion in contact with the vehicle glass surface through the switching bridge may be equally applicable.

However, in the present invention, as shown in Figure 2, the two wiper rubbers are formed in the bonded state in the connecting portion 40, the intermediate medium for cutting the smoothly after the cutting portion of the connecting portion 40 without cutting completely Pretreatment is carried out with. The coating is then sprayed with a composition already prepared throughout the rubber for the wiper blades. After that, cut the rubber part in the middle of the connection portion 40 with a knife, each of which is used as rubber for two wiper blades.

Example 2

To the distilled water used as a solvent, 18% by weight of Teflon, 20% by weight of urethane resin, 7% by weight of graphite, and 2% by weight of silver are added the remaining weight% of various paint additives.The Teflon used is about 300 nanometers in size, The remaining components were made from fine particles of about 400 nanometers in size to form a nanometer-sized coating liquid composition.

The coating method on the wiper blade rubber by the coating composition obtained in Example 2 may be applied in the same manner as described in Example 1.

Example 3

To the distilled water used as a solvent, 8% by weight of Teflon, 9% by weight of urethane resin, 9% by weight of graphite, and 2% by weight of silver are added with the remaining weight% of various paint additives. The Teflon used is about 300 nanometers in size. The components were made from fine particles of about 400 nanometers in size to create a nanometer-sized coating liquid composition.

The method of coating on the wiper blade rubber by the coating composition obtained in Example 3 may also be applied in the same manner as described in Example 1.

Test 1 (wipe performance or wiper operation test)

The wiping performance test of the wiper blades prepared above was expressed in wiping (evaluation) scores using a test apparatus corresponding to the test apparatus used for the wiper blade performance evaluation specified in KS R 3015 and RS R 0031. This evaluation method is an emotional evaluation method that evaluates based on a score of 10 points based on a score table by driving a wiper after spraying water on a car glass.

First of all, the coating composition prepared in Example 1 was selected, and Hyundai Motor's 'EF Sonata' vehicle was selected to evaluate the wiping performance based on 10 points under weather conditions of 28.3 ° C and 74% humidity. Each score is shown in Table 1 below the experimental results using the (1-1) uncoated wiper rubber, and (1-2) the experimental results using the coated wiper rubber are shown in Table 2 below.

Table 1 (Experimental results before rubber coating)

One 2 3 4 5 6 7 8 9 10 11 12 13 14 Average up 6 6 7 6 5 7 5 4 6 6 5 7 6 6 5.9 down 7 7 7 6 5 6 4 5 5 6 5 5 5 6 5.6

Table 2 (Experimental Result after Rubber Coating)

One 2 3 4 5 6 7 8 9 10 11 12 13 14 Average up 9 9 9 9 8 10 8 8 9 9 10 9 10 10 9.1 down 9 9 9 9 9 9 8 8 9 9 10 8 9 10 8.9

When comparing Table 1 and Table 2, the rubber for wiper blades before rubber coating had an average of 5.9 when the wiper was up in the wiping performance, while an average of down was 5.6, whereas the coating was The rubber for the wiper blades afterwards showed that the average of the wiper up was 9.1 and the average of the down was 8.9 in the wiping performance. In the sensitivity evaluation of the wiping performance, it can be seen that the rubber for wiper blades after coating is about twice as good as the rubber for wiper blades before rubber coating.

Test 2 (water repellent coating test)

Water repellent durability (water repellency = water repellent area of the wiper / total working area of the wiper * 100,%) was carried out under the conditions specified in the JIS D5710 standard, the water repellent test by coating the wiper blade (1) in Example 1 When the water-repellent test was performed as it is with the wiper blade coated with the obtained coating composition, it was divided into the case where the water-repellent test was carried out with (2) the wiper blade coated with the coating composition of Example 1 after applying it in advance with water-repellent tissue. Here, the water repellent tissue is simply wiped off with a commercial water repellent tissue, and since the water repellent tissue has a water repellent solution on it, if you apply it first, the water repellent fluid can be added to the glass to get an additional water repellent effect. .

The test comparison target was a commercially available product of 'Carex' water repellent coating wiper (denoted as 'commercial product'), and the product of the present invention was designated as 'NTP815', and in 'commercial product' toluene as a solvent and a water-soluble resin Although harmful substances such as xylene were used as the present invention, 'NTP815' of the present invention is an environmentally friendly product using urethane resin as a water-soluble resin and distilled water harmless to the human body.

(2-1) Water repellency test without water repellent tissue

Four of 114 rounds, 228 rounds, 380 rounds, and 5,380 rounds were selected as the number of round trips of the wiper, and the results are shown in Table 3 below. Actual test result photographs are shown in FIGS. 4 and 5.

(Table 3)

division Water repellency rate (%) Number of tests 114 228 380 5,380 Commercial product 85.0 95.0 100.0 100.0 NTP815 98.0 100.0 100.0 100.0

When analyzing the results of Table 3, without the water repellent tissue construction, the initial water repellency test results, the initial water repellency of the product of the present invention increases the area of about 12% further increases the initial water repellency of the present invention It was found to be improved.

(2-2) Water repellency rate test after applying water repellent tissue beforehand

A total of 15 times were selected as the number of round trip tests of the wiper, and the results thereof are shown in Table 4, and a graph of their water repellency rate x test times is shown in FIG. 6, and actual test results are shown in FIGS. 7 to 9. It was.

(Table 4)

division Water repellency rate (%) Number of tests 114 228 380 5,380 10,380 20,380 30,380 40,380 Commercial product 100.0 100.0 100.0 100.0 100.0 97.0 95.0 93.0 NTP815 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Number of tests 50,380 60,380 70,380 80,380 90,380 100,380 110,380 Commercial product 90.0 87.0 85.0 81.0 78.0 73.0 70.0 NTP815 97.0 97.0 95.0 93.0 93.0 90.0 88.0

In analyzing the results of Table 4, after the water repellent tissue construction, as a result of the water repellency test, it was found that the durability of the present invention is improved because the durability of the water repellency of the product of the present invention is increased by about 18%.

Exam 3 (friction test)

The friction test was not conducted according to any standard test standard, but was evaluated to determine the magnitude of the friction force large and small by the amount of current. Here, the resistance value used as a measure of frictional force was used as a comparison measure to compare the frictional force of the wiper rubber, rather than to mean a quantitative resistance value. In other words, the amount of current changes while a constant voltage is flowing when driving the wiper, which is based on the principle that a small amount of current flows when the surface friction is small and a large amount of current flows when the friction is large.

The coefficient of friction is tested for the comparative product ('commercial product') and the product of the present invention ('NTP815') in the dry state (DRY) and the wet state (WET) without applying water repellent tissue in relation to the initial water repellency test. These results are shown in FIGS. 10 and 11.

As a result of this test, the coefficient of friction is not quantitative, and can only be used to determine the relative friction by comparing the amount of current. I could see that.

In addition, when the test composition is selected and carried out in the coating compositions prepared in Examples 2 and 3, the results are similar to the above, so the specific comparison table is omitted.

1 is a cross-sectional view of a conventional wiper rubber combined with a head portion having an inner elastic rail and a wedge portion in contact with the vehicle glass surface.

FIG. 2 is a cross-sectional view of two wiper rubbers according to the present invention in which two wiper rubbers in which a head portion having an outer elastic rail and a wedge portion in contact with the vehicle glass surface are integrally facing each other are weakly connected.

Figure 3 is a graph showing the water repellency test results of the water repellency test (%) and the number of test times for the wiper blade coated in a state not previously constructed with a water repellent tissue.

4 and 5 are photographs of the windshield of the vehicle showing the initial water repellency of the comparison product (commercial product) and the product of the present invention (NTP815) according to the number of round trips.

Figure 6 is a graph showing the water repellency rate (%) and the number of test times of the water repellent test results after the construction in advance with a water repellent tissue.

7 is a photograph of the windshield of the vehicle showing the durability water repellency rate of the comparative product (commercial product) according to the number of round trip after the construction in advance with a water repellent tissue.

8 and 9 is a picture of the windshield of the car showing the durability of the water repellency rate of the product of the present invention (NTP815) according to the number of round trip after the construction in advance with water repellent tissue.

10 is a graph photograph showing the coefficient of friction of the comparative product (commercial product) in the dry (DRY) and wet (WET) states, respectively, without prior construction with a water repellent tissue.

11 is a graph photograph showing the coefficient of friction of the product of the present invention (NTP815) in the dry (DRY) and wet (WET) state, respectively, without prior construction with a water repellent tissue.

Claims (8)

In the wiper blade coating composition containing Teflon, water-soluble urethane resin, silicone resin in a solvent, in order to coat the rubber for vehicle wiper blades, (1) the content of the components in the range of 3.5 to 15% by weight of teflon, 5.0 to 25.0% by weight of water-soluble urethane resin, 1.6 to 6.0% by weight of silicone resin, (2) further comprising 0.16 to 0.5% by weight of silver and 3.5 to 15% by weight of graphite (graphite) or carbon black, (3) The coating composition, wherein the solvent is distilled water, and all the constituents are present in the distilled water in the size of 50 to 500 nanometers (nm). delete The coating composition of claim 1, wherein all of the components are present in the distilled water in a size of 300 to 400 nanometers (nm). delete The composition according to claim 1 or 3, wherein the rubber is natural rubber, butadiene rubber, styrene-butadiene rubber, EPDM rubber, chloroprene rubber or silicone rubber. A method of coating rubber for wiper blades with the coating composition prepared according to claim 1. The method of claim 6, wherein the rubber is natural rubber, butadiene rubber, styrene-butadiene rubber, EPDM rubber, chloroprene rubber or silicone rubber. The method of claim 6, wherein the coating is pre-treated with an intermediate medium to facilitate the coating, and then preheated to a temperature capable of expanding the surface of the used rubber to spray the composition in a state in which the surface of the rubber is expanded. Method for coating with.

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