JP2010023710A - Manufacturing method of blade rubber and wiper blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a blade rubber excellent in wiping performance and capable of suppressing an increase of frictions under a semi dry condition. <P>SOLUTION: Two or more monomers having different properties are combined by graft polymerization from a radical active site generated by an irradiation process performed on a pair of blade rubber molding. The two or more monomers having different properties are attached to a surface of the blade rubber either before or after generation of the radical active site. By using a hydrophobic monomer and a hydrophilic monomer as the tow or more monomers having different properties, a hydrophobizing process can be performed with the hydrophobic monomer and a hydrophilizing process can be performed with the hydrophilic monomer. Thus manufactured blade rubber provides an excellent wiping performance because of improved contact with window glass under a wet condition, and inhibits the increase of frictions under the semi dry condition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technology of a blade rubber provided on a wiper blade for wiping a windshield of a vehicle, and is particularly effective when applied to a blade rubber subjected to a hydrophilic treatment.

  Cars such as passenger cars, buses, trucks, etc. are operated by wiping off dirt, snow, insects, and muddy water splashed by vehicles traveling in front of the windshield such as windshield and rear windshield. A wiper blade is used to secure a person's view.

  The blade rubber provided on this wiper blade is usually chlorinated in consideration of the friction between the blade rubber and the sliding surface of the glass, and the surface of the blade rubber is cured to lower the coefficient of friction with the glass surface. Yes.

  However, although the initial friction coefficient is reduced by chlorination, there is a problem in that when it is used for a long time, the cured portion is peeled off, the friction coefficient with the glass is increased, and the slidability is deteriorated. In other words, chlorination is a method of modifying the rubber surface by deteriorating the rubber with chlorine. For this reason, the modified rubber surface is gradually lost due to repeated sliding contact with the glass, wiping performance is reduced, the friction coefficient is increased, and the reduced friction coefficient is maintained over a long period of time. I couldn't do it. In addition, there has been a problem that chlorination places a burden on the environment due to halogen.

  Therefore, various techniques have been proposed in order to maintain the low friction property of the blade rubber surface over a long period of time. For example, in Patent Document 1, a water repellent component is gradually deposited from a wiper blade by kneading a support body containing a water repellent component into a wiper blade body made of a natural rubber composition and a coating layer formed on the surface of the lip portion. A wiper blade that can maintain water repellency over a long period of time has been proposed.

In addition, a wiper blade (see, for example, Patent Document 2) impregnated with an isocyanate treatment liquid to harden the rubber surface, or a radical monomer activated by irradiation treatment to graft polymerize a hydrophobic monomer to modify the surface. It has been proposed to perform a treatment in place of the chlorination treatment as in the blade rubber (for example, see Patent Document 3).
JP 2004-50974 A JP 2002-161154 A JP 2008-24091 A

  However, the proposal of Patent Document 2 is the same as chlorination in that the rubber surface is deteriorated, and therefore it is not sufficient to maintain the low friction property of the blade rubber surface over a long period of time. In the proposals of Patent Documents 1 and 3, since the hydrophobic treatment is performed, there is a problem that the glass is difficult to adhere to the glass in a wet state during raindrop wiping, and wiping unevenness is likely to occur in the glass.

  On the other hand, when the hydrophilization treatment is performed on the blade rubber surface, adhesion to the glass is good in a wet state, and wiping property is improved. Further, the surface hardness is improved, and the friction can be reduced in a dry state in which there is no water droplets on the glass, such as when the weather is clear or cloudy.

  However, the hydrophilization treatment alone has a problem that the friction becomes high in a state between the wet state and the dry state. That is, the wiper blade has the highest frictional resistance in a state called semi-dry in which only a part of the glass is wet, such as when the rain starts from the wet state when it rains and the glass starts to dry, or during drizzle. If the rubber surface has high hydrophilicity, adhesion to the glass becomes strong in this semi-dry state, and the frictional resistance increases.

  An object of the present invention is to make it possible to manufacture a blade rubber that has excellent wiping properties and can suppress an increase in friction in a semi-dry state.

  The blade rubber manufacturing method of the present invention is a blade rubber having a head part formed in a rectangular cross section, a lip part in contact with a surface of a windshield of a vehicle, and a neck part for coupling the head part and the lip part. A method of forming the blade rubber, a step of attaching two or more types of monomers having different properties to at least the lip portion of the molded blade rubber, and two or more types of different properties. A step of generating a radical active site on the surface of the portion to which the monomer is attached by irradiation treatment, and a step of bonding two or more monomers having different properties to the generated radical active site by graft polymerization It is characterized by having.

  The blade rubber manufacturing method of the present invention is a blade rubber having a head part formed in a rectangular cross section, a lip part in contact with a surface of a windshield of a vehicle, and a neck part for coupling the head part and the lip part. A method of forming the blade rubber, a step of attaching two or more types of monomers having different properties to at least the lip portion of the molded blade rubber, and two or more types of different properties. A step of irradiating a portion to which the monomer is attached to generate a radical active site on the surface of the portion, and combining the generated radical active site with two or more monomers having different properties by graft polymerization; It is characterized by having.

  The blade rubber manufacturing method of the present invention is a blade rubber having a head part formed in a rectangular cross section, a lip part in contact with a surface of a windshield of a vehicle, and a neck part for coupling the head part and the lip part. A method of forming the blade rubber, and a step of generating a radical active site on a surface of the portion subjected to the irradiation treatment by irradiating at least the lip portion of the molded blade rubber. And a step of attaching two or more types of monomers having different properties to the portion where the radical active site is generated, and a step of bonding the two or more types of monomers having different properties to the generated radical active site by graft polymerization It is characterized by having.

  The blade rubber manufacturing method of the present invention is a blade rubber having a head part formed in a rectangular cross section, a lip part in contact with a surface of a windshield of a vehicle, and a neck part for coupling the head part and the lip part. A method of forming the blade rubber, a step of irradiating at least a lip portion of the molded blade rubber to generate a radical active site on the surface of the lip portion, and the radical active site Attach two or more types of monomers with different properties to the part where the product is formed, and bond the two or more types of monomers with different properties by graft polymerization to the radical active site to which two or more types of monomers with different properties are attached And a step of making it.

  The blade rubber manufacturing method of the present invention is a blade rubber having a head part formed in a rectangular cross section, a lip part in contact with a surface of a windshield of a vehicle, and a neck part for coupling the head part and the lip part. A method of forming a blade rubber intermediate body in which a pair of the lip portions face each other, and a step of attaching two or more types of monomers having different properties to at least the lip portion of the molded blade rubber intermediate body Irradiating a portion where two or more types of monomers having different properties are attached to generate radical active sites on the surface of the portion, and generating the radical active sites by graft polymerization on the generated radical active sites. Separating two or more different types of monomers from each other by cutting the blade rubber intermediate at the lip And having a degree, the.

  The blade rubber manufacturing method of the present invention is a blade rubber having a head part formed in a rectangular cross section, a lip part in contact with a surface of a windshield of a vehicle, and a neck part for coupling the head part and the lip part. A method of forming a blade rubber intermediate body in which a pair of the lip portions face each other, and a step of attaching two or more types of monomers having different properties to at least the lip portion of the molded blade rubber intermediate body In addition, the portion where two or more kinds of monomers having different properties are attached is irradiated to generate radical active sites on the surface of the portions, and the properties are different by graft polymerization on the generated radical active sites. Separating two or more types of monomers by cutting the blade rubber intermediate at the lip portion And having a step.

  The blade rubber manufacturing method of the present invention is a blade rubber having a head part formed in a rectangular cross section, a lip part in contact with a surface of a windshield of a vehicle, and a neck part for coupling the head part and the lip part. A method of forming a blade rubber intermediate body in which a pair of lip portions face each other, and at least the lip portion of the formed blade rubber intermediate body is irradiated with a radical activity on the surface of the portion. A step of generating a point, a step of attaching two or more types of monomers having different properties to the portion where the radical active site is generated, and two or more types of different properties of the generated radical active site by graft polymerization. A step of combining monomers, and a step of separating the blade rubber intermediate by cutting at the lip portion. The features.

  The blade rubber manufacturing method of the present invention is a blade rubber having a head part formed in a rectangular cross section, a lip part in contact with a surface of a windshield of a vehicle, and a neck part for coupling the head part and the lip part. A method of forming a blade rubber intermediate body in which a pair of lip portions face each other, and at least the lip portion of the formed blade rubber intermediate body is irradiated with a radical activity on the surface of the portion. A step of generating a point, and two or more types of monomers having different properties are attached to the portion where the radical active point is generated, and the radical active point to which two or more types of monomers having different properties are attached by graft polymerization By combining two or more monomers having different properties, and cutting the blade rubber intermediate at the lip. Characterized in that it and a step of separating Te.

  The wiper blade of the present invention is a wiper blade for wiping a windshield of a vehicle, the head portion formed in a rectangular cross section, a lip portion in contact with the surface of the windshield of the vehicle, the head portion and the lip portion And a radical active point formed on the surface of the blade rubber by being irradiated on the blade rubber and being attached to the surface of the lip portion of the blade rubber. And two or more monomers having different properties bonded to each other by graft polymerization.

  The wiper blade of the present invention is a wiper blade for wiping a windshield of a vehicle, the head portion formed in a rectangular cross section, a lip portion in contact with the surface of the windshield of the vehicle, the head portion and the lip portion And a radical formed on the surface of the blade rubber by being irradiated with the blade rubber and being attached to both sides of the surface of the lip portion of the blade rubber. And two or more types of monomers having different properties bonded to the active site by graft polymerization.

  The wiper blade of the present invention is characterized in that the two or more types of monomers having different properties include a hydrophobic monomer and a hydrophilic monomer.

In the wiper blade of the present invention, the hydrophobic monomer includes a vinyl group (CH ₂ ═CH—), an isopropenyl group (CH ₂ ═C (CH ₃ ) —) and an allyl group (CH ₂ ═CHCH ₂ —) in the molecule. And a polymerizable monomer having at least one of the following.

  In the wiper blade of the present invention, the hydrophobic monomer has a hydrophobic structure of hydrocarbon, organosilicon, or fluorine at the molecular end, or a functional group that can impart hydrophobicity by a secondary reaction after graft polymerization It is characterized by comprising.

  In the wiper blade of the present invention, the hydrophobic monomer is ethyl methacrylate, vinyl methacrylate, styrene, cyclohexyl methacrylate, dodecyl methacrylate, ethyl acrylate, vinyl acrylate, cyclohexyl acrylate, dodecyl acrylate, trimethylsilyl methacrylate. , Trimethoxysilylpropyl methacrylate, 3- (methacryloyloxy) propyltris (trimethylsiloxy) silane, trimethylsilyl acrylate, trimethoxysilylpropyl acrylate, 3- (acryloyloxy) propyltris (trimethylsiloxy) silane, methacrylic acid 1H , 1H, 3H-tetrafluoropropyl, 2,2,2-trifluoroethyl methacrylate, 2- (perfluorobutyl) ethyl methacrylate, 1H acrylic acid IH, 3H-tetrafluoropropyl, characterized in that it comprises at least one of acrylic acid 2,2,2-trifluoroethyl and methacrylic acid 2- (perfluorobutyl) ethyl and derivatives thereof.

  In the wiper blade of the present invention, the hydrophilic monomer may be hydroxyethyl methacrylate (HEMA), hydroxyethyl acrylate (HEA), glycidyl methacrylate (GMA), or acrylamide. It is a polymerizable monomer having at least one of methacrylic acid, acrylic acid and metal salts thereof.

  The wiper blade of the present invention is characterized in that two or more types of monomers having different properties are not attached to the tip surface of the lip portion of the blade rubber.

  According to the present invention, at least the lip portion of the blade rubber is bonded with two or more monomers having different properties by graft polymerization starting from the radical active site generated by the electron beam irradiation treatment, so that the blade rubber surface is hydrophilized. By performing the hydrophobization treatment, the advantages of both treatments can be imparted. That is, in the wet state, the adhesion with the window glass is improved and excellent wiping property is obtained, and in the semi-dry state, the blade rubber surface exhibits water repellency (hydrophobicity), thereby suppressing an increase in friction.

  As a result, it is possible to manufacture a blade rubber that has excellent wiping properties and can suppress an increase in friction in a semi-dry state.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a perspective view showing a wiper blade provided with a blade rubber according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA in FIG. (B) is explanatory drawing which shows the detail of the holding | maintenance part shown in FIG. 1, respectively.

  As shown in FIG. 1, the wiper blade 11 is attached to the tip of a wiper arm 13 of a vehicle 12, and when the wiper arm 13 swings by driving a wiper motor (not shown), the wiper blade 11 swings together with the wiper arm 13 and windshield glass 14 ( Hereinafter, the wind glass 14 is wiped off.

  The wiper blade 11 has a blade rubber 15 that directly contacts the surface of the wind glass 14 and a rubber holder 16 that holds the blade rubber 15. A pair of covers 17 are provided on both sides of the rubber holder 16 in the longitudinal direction. It has been.

  As shown in FIG. 2, the blade rubber 15 is formed in a rod shape having a substantially uniform cross section in the longitudinal direction, which includes a head portion 21 having a rectangular cross section, a lip portion 22, and a neck portion 23. It contacts the surface of the wind glass 14. The neck portion 23 is formed with a narrow width in the wiping direction with respect to the head portion 21 and the lip portion 22, whereby the lip portion 22 is coupled to the head portion 21 so as to be tiltable in the wiping direction.

  Between the head portion 21 and the neck portion 23, there are formed holding grooves 24 that open on both side surfaces in the wiping direction and extend in the longitudinal direction, and mounting grooves 21a are formed in the longitudinal direction on both side surfaces of the head portion 21, respectively. It is extended and formed. A leaf spring member 25 is mounted in each of the mounting grooves 21a.

  The plate spring member 25 is formed into a flat plate shape having a length similar to that of the blade rubber 15 by punching a plate material such as a steel plate, and is elastically deformable in a direction perpendicular to the wind glass 14. That is, the blade rubber 15 to which the leaf spring member 25 is attached is elastically deformable in a direction perpendicular to the window glass 14, that is, a direction in which the degree of curvature thereof is changed integrally with the leaf spring member 25. Further, in the natural state, the leaf spring member 25 is curved more strongly than the curvature of the window glass 14 in the elastically deformable direction, whereby the blade rubber 15 to which the leaf spring member 25 is attached is also bent. It is curved more strongly than the wind glass 14 in a state away from the window.

  In the illustrated case, the leaf spring member 25 is formed of a steel plate. However, the present invention is not limited to this. For example, the leaf spring member 25 may be elastically deformable in a direction perpendicular to the wind glass 14 such as a hard resin. That's fine.

  The rubber holder 16 is formed in a U-shaped cross section including a top wall portion 16a extending in the longitudinal direction by a resin material and a pair of side wall portions 16b extending from both side portions of the top wall portion 16a toward the wind glass 14, The length of the blade rubber 15 is approximately half. An intermediate portion of the blade rubber 15 is disposed inside the rubber holder 16 and is covered with the rubber holder 16, and only the lip portion 22 is exposed to the outside. Further, as shown in FIG. 1, a mounting portion 26 is fixed to a substantially middle portion of one side wall portion 16 b in the longitudinal direction, and the rubber holder 16 is attached to the tip of the wiper arm 13 at the mounting portion 26. . Further, fins 27 are integrally formed on the top wall portion 16a, and the aerodynamic characteristics of the wiper blade 11 are improved by the fins 27.

  As shown in FIG. 1, a holding portion 31 is provided at one end of the rubber holder 16 in the longitudinal direction (the side closer to the swing center of the wiper arm 13 when the wiper blade 11 is attached to the wiper arm 13). . As shown in FIG. 3A, the holding part 31 includes a pair of holding claws 32 (in the figure, only one side is shown, but the other side is also provided with similar holding claws). These holding claws 32 are formed in the shape of a rectangular cross section protruding from the side wall portion 16b in a direction perpendicular to the longitudinal direction of the blade rubber 15 and parallel to the wiping direction, and engage with the holding grooves 24, respectively. The blade rubber 15 is held. Further, the blade rubber 15 is provided with a pair of stopper portions 33a and 33b that sandwich the holding claws 32 from the longitudinal direction, and the holding claws 32 with respect to the blade rubber 15 are held in the holding grooves 24 by the stopper portions 33a and 33b. Movement in the direction along is restricted. That is, the blade rubber 15 is held by the rubber holder 16 in a state where the holding portion 31 is positioned in the longitudinal direction.

  Similarly, a holding portion 34 is provided at the other end of the rubber holder 16 in the longitudinal direction. As shown in FIG. 3B, the holding portion 34 has a pair of holding claws each having a rectangular cross section. 35 (only one side is shown in the figure, but the other side is provided with similar holding claws). These holding claws 35 are engaged with the holding grooves 24, thereby holding the blade rubber 15. . Further, the blade rubber 15 is not provided with a stopper portion at a portion where the holding claw 35 is engaged, and the holding claw 35 is movable along the holding groove 24. That is, the blade rubber 15 is held by the holding portion 34 so as to be movable in the axial direction with respect to the rubber holder 16.

  As described above, in the wiper blade 11, the pair of holding portions 31 and 34 are provided at both ends in the longitudinal direction of the rubber holder 16, and the blade rubber 15 is held at two points of the holding portions 31 and 34. . Therefore, when the pressing force from the wiper arm 13 is applied to the rubber holder 16 via the mounting portion 26, the pressing force is applied to the blade rubber 15 from two points at both ends of the rubber holder 16, that is, from the holding portions 31 and 34. As a result, the blade rubber 15 elastically contacts the window glass 14.

  Next, the manufacturing method of the blade rubber of this invention is demonstrated. FIGS. 4A to 4D are schematic procedure diagrams schematically showing the procedure of the blade rubber manufacturing method of the present invention. As shown in FIGS. 4A to 4D, the blade rubber 15 described above includes a step of forming the blade rubber, a step of generating radical active sites by irradiation treatment on the blade rubber, and a graft starting from the radical active points. It is manufactured through a step of bonding monomers by polymerization and a step of cutting the lip portion of the blade rubber in the longitudinal direction.

  The rubber used for forming the blade rubber in the step shown in FIG. 4A may be any of the conventionally known rubbers. For example, natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), acrylonitrile-butadiene copolymer rubber (NBR), chloroprene rubber (CR), fluorine rubber (FKM) ), Butyl rubber (IIR), ethylene-propylene copolymer rubber (EPM), ethylene-propylene-diene terpolymer rubber (EPDM), hydrogenated nitrile rubber (hydrogenated NBR), silicone rubber, epichlorohydrin rubber (CO) , ECO), polysulfide rubber (T), urethane rubber (U) and the like. These may be used alone or in combination of two or more.

  These rubber materials contain commonly known additives such as vulcanizing agents (crosslinking agents), vulcanization accelerating aids, softeners, anti-aging agents, fillers, silane coupling agents, silica, and carbon black. Then, it can be formed into a brate rubber by a conventionally known method such as press molding.

  Examples of the irradiation process for generating radical active sites on the blade rubber formed in the step shown in FIG. 4B include, for example, an electron beam irradiation process, an ultraviolet irradiation process, a plasma irradiation process, radiation (α rays, β rays, Examples include irradiation treatment with a radiation source that induces activation such as γ-ray, X-ray) irradiation treatment, laser beam irradiation treatment, ion beam irradiation treatment, corona discharge irradiation treatment, etc. Electron beam irradiation treatment is particularly preferable. By performing such irradiation treatment, radical active sites are generated in the blade rubber, and the graft polymerization reaction proceeds from the radical active sites as a starting point in the step shown in FIG.

  5 (a) and 5 (b) are explanatory views showing the reaction modes of the irradiation process, respectively. 5A and 5B show only the lip portion of the blade rubber formed before the blade rubber is cut, that is, the lip portions of the pair of blade rubbers face each other. As shown in FIGS. 5 (a) and 5 (b), there are two methods for the irradiation treatment for promoting the graft polymerization reaction starting from the generated radical active site.

  In the treatment shown in FIG. 5A, a radical active site is generated by irradiating rubber with an electron beam and the like, and then a monomer is attached to the blade rubber surface, and then a reactant (monomer) is bonded by graft polymerization. That is, it is a pre-irradiation process in which a radical active point is generated by performing an irradiation process in advance. In the pre-irradiation treatment, both the irradiation treatment and the graft polymerization reaction are preferably performed in a nitrogen atmosphere. The absorbed dose of the pre-irradiation treatment is preferably 50 to 500 kGy in a deoxygenated state. In FIG. 5A, the monomer is attached after the radical active point is generated. However, the present invention is not limited to this, and the radical active point may be generated after the monomer is attached to the blade rubber.

  The process shown in FIG. 5B is a simultaneous irradiation process in which the generation of radical active sites and graft polymerization are simultaneously performed. In the simultaneous irradiation treatment, for example, irradiation with an electron beam or the like for generating the above-described radical active site is performed in a state in which a reactant used for graft polymerization is attached to the surface of the blade rubber by coating or dipping. The absorbed dose of the simultaneous irradiation treatment is preferably 10 to 100 kGy. In the present invention, the blade rubber can be manufactured by any of the pre-irradiation process and the simultaneous irradiation process. In FIG. 5B, the radical active point is generated after the monomer is attached to the surface of the blade rubber. However, the present invention is not limited thereto, and the monomer may be attached after the radical active point is generated. Good.

  In the step shown in FIG. 4C, graft polymerization can be performed by a generally known method, but two or more types of monomers having different properties are used as the polymerizable monomer used in the graft polymerization. Examples of the two or more types of monomers having different properties include a hydrophobic monomer and a hydrophilic monomer. That is, the surface of the blade rubber is subjected to a hydrophobic treatment with a hydrophobic monomer and a hydrophilic treatment with a hydrophilic monomer.

The hydrophobic monomer has at least one of a vinyl group (CH ₂ ═CH—), an isopropenyl group (CH ₂ ═C (CH ₃ ) —) and an allyl group (CH ₂ ═CHCH ₂ —) in the molecule. Examples of the polymerizable monomer include a compound having a hydrophobic structure of hydrocarbon, organosilicon, or fluorine at the molecular terminal, or a functional group that can impart hydrophobicity by a secondary reaction after graft polymerization.

  Examples of such hydrophobic monomers include ethyl methacrylate, vinyl methacrylate, styrene, cyclohexyl methacrylate, dodecyl methacrylate, ethyl acrylate, vinyl acrylate, cyclohexyl acrylate, dodecyl acrylate, trimethylsilyl methacrylate, methacrylic acid. Trimethoxysilylpropyl acid, 3- (methacryloyloxy) propyltris (trimethylsiloxy) silane, trimethylsilyl acrylate, trimethoxysilylpropyl acrylate, 3- (acryloyloxy) propyltris (trimethylsiloxy) silane, methacrylic acid 1H, 1H , 3H-tetrafluoropropyl, 2,2,2-trifluoroethyl methacrylate, 2- (perfluorobutyl) ethyl methacrylate, acrylic acid 1H, 1H 3H- tetrafluoropropyl, 2,2,2-trifluoroethyl acrylate, methacrylic acid 2- (perfluorobutyl) ethyl, and derivatives thereof. These hydrophobic monomers may be used alone or in combination of two or more.

  Examples of the hydrophilic monomer include hydroxyethyl methacrylate (HEMA), hydroxyethyl acrylate (HEA), glycidyl methacrylate (GMA), acrylamide, and methacrylic acid. And metal salts thereof. These hydrophilic monomers may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  As the order of the hydrophobization treatment and the hydrophilization treatment, either may be performed first. However, the hydrophobization treatment may be performed after the hydrophilization treatment first, so that the rubber surface does not repel the reaction solution or water. It is preferable because it can be easily subjected to a hydrophilic treatment. Moreover, it is preferable to perform a hydrophobization process and a hydrophilization process simultaneously from a viewpoint of processing efficiency.

  Here, when the hydrophilization treatment and the hydrophobization treatment are performed separately, after generating the radical active site through the process shown in FIG. 4B, one process is performed by the process shown in FIG. 4C. If so, the process returns to the step shown in FIG. 4B again to generate radical active sites, and then the other process is performed in the step shown in FIG. 4C. In the case where the hydrophilization treatment and the hydrophobization treatment are performed at the same time, both treatments are performed by a single step shown in FIGS. 4B and 4C.

  The blade rubber described above is manufactured as a pair of blade rubber molded bodies (blade rubber intermediate bodies) formed so that the lip portions face each other. The pair of blade rubber molded bodies are cut in the longitudinal direction at the lip portion in the step shown in FIG. 4D to form a blade rubber.

  6A is an enlarged view showing a state where the monomer is bonded only to the lip portion of FIG. 2, and FIG. 6B is an enlarged view showing a state where the monomer is bonded to the entire blade rubber of FIG. is there. In FIGS. 6A and 6B, the portion where the monomer is bonded is indicated by hatching. Since the pair of rubber moldings is cut with the graft-polymerized monomer attached, as shown in FIGS. 6 (a) and 6 (b), the monomer is attached to the cutting surface (tip surface) 36 of the blade rubber. Not done. Since the blade rubber 15 normally wipes the wind glass at the edge portion that becomes the boundary between the side surfaces 37a and 37b of the lip portion 22 and the cut surface 36, the window glass is wiped by the side surfaces 37a and 37b to which the monomer is bonded. The window glass is not wiped by the cut surface 36 to which no monomer is attached. Further, the above-described irradiation and graft polymerization treatment for generating radical active sites such as an electron beam need not be performed on a portion of the blade rubber molded body that does not come into contact with the window glass, such as a head portion. Therefore, the portions that are not irradiated with the electron beam or the like are masked in advance, and only the necessary portions such as the lip portion 22 of the blade rubber molded body are irradiated with the electron beam or the like as in the example shown in FIGS. 6 (a) and 6 (b). May be performed.

  As described above, in the present invention, two or more types of monomers having different properties are bonded to the blade rubber surface by graft polymerization starting from the radical active site generated by the irradiation treatment. For example, the hydrophilic treatment and the hydrophobic treatment are performed. By performing a plurality of surface modification treatments, the advantages of both treatments can be imparted to the blade rubber.

  That is, water absorption is imparted to the blade rubber surface by the hydrophilic treatment, and water is absorbed and softened in the wet state at the time of raindrop wiping, so that the adhesion to the wind glass is increased and precise wiping with little wiping unevenness can be performed. Further, in a dry state where there is no water droplets on the glass, such as when the weather is sunny or cloudy, the blade rubber surface is dried to increase the hardness, and friction with the wind glass can be reduced.

  And since the contact angle with water is greatly increased due to the hydrophobization treatment, it shows high water repellency, so only a part of the wind glass gets wet when it rains and the glass starts to dry or during drizzle It becomes easy to prevent water absorption in the semi-dry state where the frictional resistance is the highest. In other words, if there is water absorption in the semi-dry state, the blade rubber surface adheres to the wind glass and friction increases, but high water repellency prevents water absorption in the semi-dry state and suppresses an increase in friction with the wind glass on the blade rubber surface. It can be done.

  In addition, since the radical is activated on the surface of the blade rubber and the monomer is bonded by graft polymerization starting from the radical active site, the surface treatment layer is difficult to peel off from the rubber used for forming the blade rubber and has excellent durability. Rubber is obtained.

  Furthermore, since the surface treatment can be performed without using halogen by irradiation treatment, a blade rubber can be produced without imposing a burden on the environment.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments and examples, but the present invention is not limited to the embodiments and examples, and is within the scope not departing from the gist thereof. It goes without saying that various changes can be made.

  For example, in the present embodiment, the blade rubber 15 is manufactured as a pair of blade rubber molded bodies formed such that the lip portions 22 face each other, and the blade rubber 15 is cut in the longitudinal direction at the lip portions 22. However, the present invention is not limited to this, and the blade rubber 15 may be separately formed from the beginning, and the cutting step may be omitted.

  In the present embodiment, the wiper blade 11 wipes the front window glass 14 of the vehicle 12. However, the present invention is not limited to this, and the wiper blade 11 may wipe the rear window glass of the vehicle 12. Good.

  Further, in the present embodiment, the leaf spring member 25 is attached to the attachment groove 21a of the blade rubber 15. However, the structure is not limited to this, and the leaf spring member 25 is directly fixed to the blade rubber 15 by adhesion or the like. Also good.

  Furthermore, the present invention can be applied to wiper blades used in various types of wiper apparatuses such as a tandem type and a counter wiping type.

Hereinafter, based on an Example, this invention is demonstrated in detail.
[Experiment 1] Confirmation of water absorption A pair of blade rubber moldings were molded by press molding by blending 100 phr of EPDM with 5 phr of vulcanizing agent, 5 phr of zinc oxide, 2 phr of stearic acid, 1 phr of vulcanization accelerator, and 50 phr of carbon black.

  Radical activity by electron beam irradiation is performed by immersing this blade rubber molded body in an aqueous solution having a HEMA concentration of 50% by weight as a hydrophilic monomer and performing simultaneous irradiation treatment with an electron beam of 20 kGy shown in FIG. The surface of the blade rubber molded body was subjected to a hydrophilization treatment by simultaneously performing point generation and graft polymerization of HEMA. Next, the blade rubber molding was immersed in a 50% by weight methanol solution of trimethoxysilylpropyl methacrylate (MPTS) as a hydrophobic monomer. By simultaneously irradiating this methanol solution with a 10 kGy electron beam at 25 ° C. as shown in FIG. 5B, radical active sites by electron beam irradiation and MPTS graft polymerization are performed, thereby forming a blade rubber. The body surface was hydrophobized.

  The blade rubber molded body of each of the untreated stage before the hydrophilization treatment, the stage where only the hydrophilization treatment was performed, and the stage where both the hydrophilization treatment and the hydrophobization treatment were performed was in a dry state with no water droplets on the surface. The surface hardness of the blade rubber surface in a wet state where the surface was sufficiently wet was measured with a micro hardness meter manufactured by Kobunshi Keiki Co., Ltd. The results are shown in Table 1 and the graph of FIG.

表１および図７の結果より、親水化処理を行ったブレードラバー成形体の表面にさらに疎水化処理を行っても、ドライ状態およびウエット状態の双方で未処理段階からの表面硬度変化がおこることがわかった。つまり、親水化処理を行ったブレードラバー成形体の表面上に疎水化処理を行っても、表面処理層の吸水性が維持されてウエット状態で水を吸って軟化する。これにより、降雨時にブレードラバーが軟化して払拭対象のガラスに対する追従性が向上し、高い払拭性を示すことが期待できる。

From the results of Table 1 and FIG. 7, even if the surface of the blade rubber molded body subjected to the hydrophilization treatment is further hydrophobized, the surface hardness changes from the untreated stage in both the dry state and the wet state. I understood. That is, even if the hydrophilization treatment is performed on the surface of the blade rubber molded body, the water absorption of the surface treatment layer is maintained and water is absorbed in a wet state to be softened. Thereby, it can be expected that the blade rubber is softened during the rain and the followability to the glass to be wiped is improved, and high wiping property is exhibited.

[Experiment 2] Confirmation of water repellency 2 μl of ion-exchanged water was dropped on the surface-treated surface with a microburette for each untreated, hydrophilized, and hydrophobized blade rubber molded body of Experiment 1 above. The contact angle was measured from the shape of the droplet. The results are shown in Table 2 and FIG.

表２および図８の結果より、ブレードラバー成形体表面の水の接触角は、親水化処理により大きく低下するが、さらに疎水化処理を行うと大幅に上昇して高い撥水性を示すことがわかった。このことよりセミドライ状態での摩擦上昇抑制が期待できる。

From the results shown in Table 2 and FIG. 8, it can be seen that the water contact angle on the surface of the blade rubber molded body is greatly reduced by the hydrophilization treatment, but is further increased by the hydrophobization treatment to show high water repellency. It was. This can be expected to suppress the increase in friction in the semi-dry state.

[Experiment 3] Evaluation of wiping property The blade rubber molded body subjected to the hydrophilization treatment and the hydrophobic treatment in Experiment 1 was cut to produce a blade rubber. Also, a blade rubber was produced in the same manner even with a blade rubber molded body that was different in that it was not hydrophilized. About each blade rubber, the wiper blade shown in FIG. 1 was assembled and the wiping property was evaluated according to JIS D5710.

  In other words, of the sliding area of the blade rubber, the remaining wipes of various widths in the sliding area (M zone) of each quarter from the center point to both ends and the sliding area other than the M zone (S zone) Numerical values were measured. Leftover wipes of various widths are left as follows: very fine streak-like wipes with a width of 0.5 mm or less (hair line), fine streak-like residues with a width of 1 mm or less (heavy line), and strip-like leftovers with a width of about 1 to 20 mm (wide) Line).

  As a result, the blade rubber of the present invention produced by cutting a hydrophilized and hydrophobized blade rubber molded body has less wiping residue as compared to a blade rubber that has not been hydrophilized, It was found that the wiping property was excellent.

  The blade rubber produced in the same manner except that the hydrophilic monomer and the hydrophobic monomer are respectively replaced with each other in the case where the hydrophilic treatment and the hydrophobic treatment are performed and the case where the hydrophilic treatment is not performed. Was evaluated. It was found that the blade rubber of the present invention that was both hydrophilized and hydrophobized had less wiping residue and superior wiping performance compared to the blade rubber that was not hydrophilized. .

[Experiment 4] Friction suppression increase evaluation in semi-dry state For each blade rubber of the present invention subjected to both the hydrophilization treatment and the hydrophobization treatment evaluated for wiping property in the experiment 1 above, the friction resistance while sliding under the following conditions The change with time was examined. Further, different blade rubbers were produced only in that each blade rubber was not hydrophobized, and the change in the coefficient of friction with time was similarly examined.

Sample width: 10 mm
Load: 15gf
Sliding radius: 70mm
Rotation speed: 173.5 rpm
Sliding speed: 1.3m / s
Sliding state: wet → dry Humidity: 25 ° C 70%
Counterpart material: glass plate As a result, the blade rubber of the present invention subjected to the hydrophilization treatment and the hydrophobization treatment showed an extremely small increase in frictional resistance even in the semi-dry state from the wet state to the dry state. On the other hand, the blade rubber that was not hydrophobized had a large increase in frictional resistance in the semi-dry state. From this, it was found that the blade rubber of the present invention subjected to the hydrophilization treatment and the hydrophobization treatment is extremely excellent in the effect of suppressing the increase in friction in the semi-dry state.

  The present invention can be used for a blade rubber provided on a wiper blade for wiping a windshield of a vehicle.

It is a perspective view which shows the wiper blade provided with the blade rubber which is one embodiment of this invention. It is sectional drawing which follows the AA line of FIG. (A), (b) is explanatory drawing which shows the detail of the holding | maintenance part shown in FIG. 1, respectively. (A)-(d) is a schematic procedure figure which shows roughly the procedure of the manufacturing method of the blade rubber of this invention. (A), (b) is explanatory drawing which shows the reaction form of an irradiation process, respectively. (A) is an enlarged view showing a state where the monomer is bonded only to the lip portion of FIG. 2, and (b) is an enlarged view showing a state where the monomer is bonded to the entire blade rubber of FIG. 6 is a graph showing the water absorption confirmation result of Experiment 1. 6 is a graph showing the results of confirmation of water repellency in Experiment 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Wiper blade 12 Vehicle 13 Wiper arm 14 Front window glass 15 Blade rubber 16 Rubber holder 16a Top wall part 16b Side wall part 17 Cover 21 Head part 21a Mounting groove 22 Lip part 23 Neck part 24 Holding groove 25 Leaf spring member 26 Attachment part 27 Fin 31 Holding part 32 Holding claw 33a, 33b Stopper part 34 Holding part 35 Holding claw 36 Cutting surface (tip surface)
37a Both sides 37b Both sides

Claims (16)

A manufacturing method of a blade rubber having a head portion formed in a rectangular cross section, a lip portion in contact with a surface of a window glass of a vehicle, and a neck portion for connecting the head portion and the lip portion,
Forming the blade rubber;
Attaching two or more types of monomers having different properties to at least the lip portion of the molded blade rubber;
A step of generating a radical active site on the surface of the part by irradiating the part to which two or more kinds of monomers having different properties are attached;
A step of bonding two or more monomers having different properties by graft polymerization to the generated radical active site;
A method for producing a blade rubber, comprising: A manufacturing method of a blade rubber having a head portion formed in a rectangular cross section, a lip portion in contact with a surface of a window glass of a vehicle, and a neck portion for connecting the head portion and the lip portion,
Forming the blade rubber;
Attaching two or more types of monomers having different properties to at least the lip portion of the molded blade rubber;
Irradiation treatment is performed on a portion to which two or more types of monomers having different properties are attached to generate radical active sites on the surface of the portions, and two types of different properties are generated by graft polymerization on the generated radical active sites. Combining the above monomers;
A method for producing a blade rubber, comprising: A manufacturing method of a blade rubber having a head portion formed in a rectangular cross section, a lip portion in contact with a surface of a window glass of a vehicle, and a neck portion for connecting the head portion and the lip portion,
Forming the blade rubber;
A step of generating a radical active site on the surface of the irradiated portion by performing irradiation treatment on at least the lip portion of the molded blade rubber; and
Attaching two or more types of monomers having different properties to the portion where the radical active site is generated;
A step of bonding two or more monomers having different properties by graft polymerization to the generated radical active site;
A method for producing a blade rubber, comprising: A manufacturing method of a blade rubber having a head portion formed in a rectangular cross section, a lip portion in contact with a surface of a window glass of a vehicle, and a neck portion for connecting the head portion and the lip portion,
Forming the blade rubber;
A step of generating a radical active site on the surface of the lip by subjecting at least the lip of the molded blade rubber to irradiation treatment;
Two or more types of monomers having different properties are attached to the portion where the radical active site is generated, and two or more types having different properties are obtained by graft polymerization on the radical active site to which two or more types of monomers having different properties are attached. Combining the monomers of:
A method for producing a blade rubber, comprising: A manufacturing method of a blade rubber having a head portion formed in a rectangular cross section, a lip portion in contact with a surface of a window glass of a vehicle, and a neck portion for connecting the head portion and the lip portion,
Forming a blade rubber intermediate body in which the pair of lip portions face each other;
Attaching two or more types of monomers having different properties to at least the lip portion of the molded blade rubber intermediate;
A step of generating a radical active site on the surface of the part by irradiating the part to which two or more kinds of monomers having different properties are attached;
A step of bonding two or more monomers having different properties by graft polymerization to the generated radical active site;
Separating the blade rubber intermediate by cutting at the lip portion;
A method for producing a blade rubber, comprising: A manufacturing method of a blade rubber having a head portion formed in a rectangular cross section, a lip portion in contact with a surface of a window glass of a vehicle, and a neck portion for connecting the head portion and the lip portion,
Forming a blade rubber intermediate body in which the pair of lip portions face each other;
Attaching two or more types of monomers having different properties to at least the lip portion of the molded blade rubber intermediate;
Irradiation treatment is performed on a portion to which two or more types of monomers having different properties are attached to generate radical active sites on the surface of the portions, and two types of different properties are generated by graft polymerization on the generated radical active sites. Combining the above monomers;
Separating the blade rubber intermediate by cutting at the lip portion;
A method for producing a blade rubber, comprising: A manufacturing method of a blade rubber having a head portion formed in a rectangular cross section, a lip portion in contact with a surface of a window glass of a vehicle, and a neck portion for connecting the head portion and the lip portion,
Forming a blade rubber intermediate body in which the pair of lip portions face each other;
Subjecting at least the lip part of the molded blade rubber intermediate to irradiation treatment to generate radical active sites on the surface of the part; and
Attaching two or more types of monomers having different properties to the portion where the radical active site is generated;
A step of bonding two or more monomers having different properties by graft polymerization to the generated radical active site;
Separating the blade rubber intermediate by cutting at the lip portion;
A method for producing a blade rubber, comprising: A manufacturing method of a blade rubber having a head portion formed in a rectangular cross section, a lip portion in contact with a surface of a window glass of a vehicle, and a neck portion for connecting the head portion and the lip portion,
Forming a blade rubber intermediate body in which the pair of lip portions face each other;
Subjecting at least the lip part of the molded blade rubber intermediate to irradiation treatment to generate radical active sites on the surface of the part; and
Two or more types of monomers having different properties are attached to the portion where the radical active site is generated, and two or more types having different properties are obtained by graft polymerization on the radical active site to which two or more types of monomers having different properties are attached. Combining the monomers of:
Separating the blade rubber intermediate by cutting at the lip portion;
A method for producing a blade rubber, comprising: A wiper blade for wiping a window glass of a vehicle, a head portion formed in a rectangular cross section, a lip portion in contact with a surface of a vehicle wind glass, and a neck portion that couples the head portion and the lip portion A blade rubber having
Two or more types having different properties that are attached to the surface of the lip portion of the blade rubber and bonded by radical polymerization to radical active sites formed on the surface of the blade rubber by being irradiated with the blade rubber. A wiper blade characterized by comprising: A wiper blade for wiping a window glass of a vehicle, comprising: a head portion formed in a rectangular cross section; a lip portion that contacts a surface of the vehicle wind glass; and a neck portion that connects the head portion and the lip portion. A blade rubber having,
Attached to both sides of the surface of the lip portion of the blade rubber, and has different properties of being bonded by radical polymerization to radical active sites formed on the surface of the blade rubber by being irradiated with the blade rubber. A wiper blade comprising two or more types of monomers.   The wiper blade according to claim 9 or 10, wherein the two or more types of monomers having different properties include a hydrophobic monomer and a hydrophilic monomer. The wiper blade according to claim 11, wherein the hydrophobic monomer includes a vinyl group (CH ₂ ═CH—), an isopropenyl group (CH ₂ ═C (CH ₃ ) —) and an allyl group (CH ₂ ═) in the molecule. A wiper blade, which is a polymerizable monomer having at least one of CHCH ₂ —).   The wiper blade according to claim 11 or 12, wherein the hydrophobic monomer has a hydrophobic structure of hydrocarbon, organosilicon or fluorine at the molecular end, or can be imparted with hydrophobicity by a secondary reaction after graft polymerization. A wiper blade comprising a compound having a functional group.   The wiper blade according to any one of claims 11 to 13, wherein the hydrophobic monomer is ethyl methacrylate, vinyl methacrylate, styrene, cyclohexyl methacrylate, dodecyl methacrylate, ethyl acrylate, vinyl acrylate, acrylic. Cyclohexyl acid, dodecyl acrylate, trimethylsilyl methacrylate, trimethoxysilylpropyl methacrylate, 3- (methacryloyloxy) propyltris (trimethylsiloxy) silane, trimethylsilyl acrylate, trimethoxysilylpropyl acrylate, 3- (acryloyloxy) propyl Tris (trimethylsiloxy) silane, 1H, 1H, 3H-tetrafluoropropyl methacrylate, 2,2,2-trifluoroethyl methacrylate, 2- (Perf) Orobutyl) ethyl, 1H, 1H, 3H-tetrafluoropropyl acrylate, 2,2,2-trifluoroethyl acrylate, 2- (perfluorobutyl) ethyl methacrylate and derivatives thereof Wiper blade characterized by.   The wiper blade according to any one of claims 11 to 14, wherein the hydrophilic monomer includes hydroxyethyl methacrylate (HEMA), hydroxyethyl acrylate (HEA), glycidyl methacrylate. A wiper blade, which is a polymerizable monomer having at least one of acrylate (Glycyl methacrylate: GMA), acrylamide, methacrylic acid, acrylic acid and metal salts thereof. The wiper blade according to any one of claims 11 to 15, wherein two or more types of monomers having different properties are not attached to a tip surface of a lip portion of the blade rubber. .

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