Vehicle wiper blades

Abstract

To provide a wiper blade for a vehicle, capable of stably exhibiting excellent wiping performance.SOLUTION: A wiper blade for a vehicle includes a blade support part and a lip part. The lip part includes a taper part in which a cross section in a direction orthogonal to the longitudinal direction of the wiper blade has a width gradually reduced from a side closer to the blade support part in a direction away from the blade support part. The lip part includes: a first taper surface and a second taper surface which constitute the taper part; and a tip surface. The average value of elastic modulus values obtained by measurement at a pitch of 0.1 μm in specific observation regions in the first taper surface and the second taper surface is 15 MPa-470 MPa, and the variation coefficient of the elastic modulus is 17.6% or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle wiper blade that wipes the surface of a member to be cleaned. [Background technology]

[0002] 2. Description of the Related Art Automobiles, trains, ships, and aircraft are equipped with cleaning members to wipe away water droplets and dirt adhering to glass surfaces such as windshields and rear windows to ensure visibility for the driver. Among these cleaning members, wiper blades, which have a wiper blade rubber attached to the portion that comes into contact with the glass surface, are well known. This wiper blade rubber moves in close contact with the glass surface, thereby wiping away water droplets and other debris adhering to the glass surface. From the perspective of ensuring good visibility for the driver, wiper blades with excellent wiping properties are desired, capable of thoroughly wiping away water droplets and dirt from the glass surface.

[0003] Patent Document 1 discloses that by forming a coating film containing carbon fibers on the surface of wiper blade rubber, it is possible to improve wiping quality over a required service life. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2011-518713 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, in order to ensure good visibility, glass surfaces have often been treated with water-repellent coatings or wax coatings. While this improves wiping performance in certain areas, it can cause uneven contact with the glass surface, resulting in chattering. The abnormal noise caused by the uneven contact is unpleasant for the driver, and the chattering itself can lead to a decrease in wiping performance. It was found that the wiper blade disclosed in Patent Document 1 had minute contact unevenness due to the dispersion state of the added carbon fibers and the state of the coating. When a vehicle wiper blade was used in such a state, contact unevenness could occur in wiping off water droplets. On the other hand, conventional wiper blades, such as those described in Patent Document 1, sometimes have difficulty in wiping away highly adhesive dirt such as fine particles contained in vehicle exhaust gases, dust particles from asphalt, and oil films that adhere to the glass surface. One aspect of the present disclosure is to provide a wiper blade for a vehicle that can stably exhibit excellent wiping performance, capable of effectively scraping off even highly adhesive dirt such as dust and oil film that adheres to a member to be cleaned. [Means for solving the problem]

[0006] The inventors have discovered that in order to improve the wiping ability of vehicle wiper blades to wipe away highly adhesive dirt such as dust and oil film, it is effective to control the elastic modulus and its coefficient of variation of a specific part of the tapered portion that comes into contact with the object to be cleaned within a specific range.

[0007] According to one aspect of the present disclosure, 1. A vehicle wiper blade for a vehicle windshield wiper device, comprising: a blade support; a lip portion pivotally connected to the blade support portion via a neck, The lip portion has a tapered portion in which a cross section in a direction perpendicular to the longitudinal direction of the wiper blade gradually decreases in width from a side closer to the blade support portion toward a direction away from the blade support portion, The lip portion is a first tapered surface and a second tapered surface that constitute the tapered portion; a tip end surface that, together with the first tapered surface and the second tapered surface, constitutes a first edge and a second edge on the side of the lip portion farthest from the blade support portion, Assuming that a first line segment is drawn on the first tapered surface parallel to the first edge and at a distance of 10 μm from the first edge, The length of the first line segment is L1, The points (1 / 8)L1, (1 / 2)L1, and (7 / 8)L1 from one end side on the first line segment are designated as P0, P1, and P2, respectively; the elastic modulus of the first tapered surface is measured at 70,000 points at a pitch of 0.1 μm using a scanning probe microscope for each of three rectangular observation regions on the first tapered surface, each of which has a center of gravity at each of the points P0, P1, and P2, one side of which is 70 μm long and parallel to the first line segment, and one side of which is 10 μm long and perpendicular to the first line segment; and the average value of the elastic modulus values ​​obtained for a total of 210,000 points is 15 MPa to 470 MPa, and the coefficient of variation of the elastic modulus is 17.6% or less; Assuming that a second line segment is drawn on the second tapered surface parallel to the second edge and at a distance of 10 μm from the second edge, The length of the second line segment is L2, The points (1 / 8)L2, (1 / 2)L2, and (7 / 8)L2 from one end side on the second line segment are designated as P3, P4, and P5, respectively; The elastic modulus of the second tapered surface is measured at 70,000 points at a pitch of 0.1 μm for each of three rectangular observation regions of the second tapered surface, each of which has a center of gravity at each of the points P3, P4, and P5, one side of which is 70 μm long and parallel to the second line segment, and one side of which is 10 μm long and perpendicular to the second line segment, using a scanning probe microscope. The average value of the elastic modulus values ​​obtained for a total of 210,000 points is 15 MPa to 470 MPa, and the coefficient of variation of the elastic modulus is 17.6% or less. the law of nature, the tapered portion contains polyurethane; The polyurethane is an isocyanate containing a diisocyanate and a trifunctional or higher polyfunctional isocyanate. a reactant of a raw material composition containing a socyanate compound, Assuming that a line segment is drawn on the first tapered surface and the second tapered surface of the tapered portion, parallel to the first edge and the second edge, respectively, and the distance between the first edge and the second edge is 0.5 mm, the length of the line segment is L', and points 1 / 8L', 1 / 2L', and 7 / 8L' from one end side on the line segment are P0', P1', and P2', respectively; The sample sampled at each of the P0', P1', and P2' points on the first tapered surface and the second tapered surface is heated and vaporized in an ionization chamber, and the sample molecules are ionized using a direct sample introduction mass spectrometer, and the sample is heated to 1000°C at a heating rate of 10°C / s. The detected amount of all ions is M1. the integrated intensity of the peak in the extracted ion thermogram corresponding to the m / z value range derived from the tri- or higher functional isocyanate is defined as M2; When the integrated intensity of the peak in the extracted ion thermogram corresponding to the range of m / z values ​​derived from the diisocyanate is M3, In the first tapered surface, M2 / M1 is 0.0010 to 0.0150, and M3 / M1 is 0.0200 to 0.1100, On the second tapered surface, M2 / M1 is 0.0010 to 0.0150, and M3 / M1 is 0.0200 to 0.1100. A wiper blade for a vehicle is provided. [Effects of the Invention]

[0008] According to one aspect of the present disclosure, a wiper blade for a vehicle can be provided that can stably exhibit excellent wiping performance, capable of effectively scraping off even highly adhesive dirt such as dust and oil film adhering to a member to be cleaned. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a wiper blade. [Figure 2] 2(a) and 2(b) are explanatory diagrams showing the state of the wiper blade during cleaning. [Figure 3] An enlarged view of the vicinity of the first edge. [Figure 4] An enlarged view of the vicinity of the first line segment. [Figure 5] An enlarged view of the vicinity of observation area 12 with P0 as the center of gravity. [Figure 6] 6(a) and (b) are schematic diagrams of the wiper blade and the vicinity of the contact point with the member to be cleaned. DETAILED DESCRIPTION OF THE INVENTION

[0010] In the present disclosure, unless otherwise specified, the expressions "XX or more and YY or less" and "XX to YY" representing a numerical range mean a numerical range including the endpoints, that is, the lower limit and the upper limit. When numerical ranges are stated in stages, the upper and lower limits of each numerical range can be combined in any way.

[0011] <Configuration of vehicle wiper blades> A vehicle wiper blade (hereinafter simply referred to as a wiper blade) according to one embodiment of the present disclosure can be used in equipment such as vehicles such as automobiles, transportation equipment such as airplanes and ships, and industrial machinery and equipment such as construction machinery. For example, as shown in Fig. 1, a vehicle wiper blade for a vehicle windshield wiper device includes a blade support portion 1 and a lip portion 3 pivotally connected to the blade support portion via a neck 2. The wiper blade is formed with a substantially uniform cross-sectional shape in the longitudinal direction. The lip portion 3 has a tapered portion 4 in which the cross section in the direction perpendicular to the longitudinal direction of the wiper blade gradually decreases in width from the side closer to the blade support portion 1 toward the direction away from the blade support portion 1. The wiper blade cleans the surface of a member to be cleaned, typically a glass surface, by bringing a part of the tapered portion into contact with the surface of the member to be cleaned. For example, the neck 2 may be configured so that its width is narrower than the blade support portion 1 and the lip portion 3 in a cross section perpendicular to the longitudinal direction of the wiper blade. As a result, as shown in FIG. 2, the lip portion 3 is inclined in the wiping direction, and a part of the tapered portion abuts against the surface of the member to be cleaned.

[0012] 2(a) and 2(b) in FIG. 2 are explanatory diagrams showing the state of the wiper blade during the cleaning process. In Figure 2(a), the lip portion 3 of the wiper blade has a first tapered surface 5 and a second tapered surface 6 opposite to the first tapered surface 5 that constitute the tapered portion 4 that contacts the member to be cleaned 10, and a tip surface 7 that, together with the first tapered surface 5 and the second tapered surface 6, constitutes a first edge 8 and a second edge 9 on the side of the lip portion 3 that is farthest from the blade support portion 1 (see Figures 1 and 3 for the first edge, second edge, and tip surface). In FIG. 2(b), the lip portion 3 of the wiper blade includes a second tapered surface 6 constituting the tapered portion 4 that contacts the member to be cleaned 10, a first tapered surface 5 opposite the second tapered surface 6, and a tip surface 7 that, together with the first tapered surface 5 and the second tapered surface 6, constitutes a first edge 8 and a second edge 9 on the side of the lip portion 3 farthest from the blade support portion 1 (see FIGS. 1 and 3 for the first edge, second edge, and tip surface). Arrow R indicates the cleaning direction of the wiper blade. When cleaning is switched from the direction of arrow R in FIG. 2(a) to the direction of arrow R in FIG. 2(b), the surface that contacts the member to be cleaned switches from the first tapered surface 5 to the second tapered surface 6.

[0013] FIG. 3 is an enlarged view of the vicinity of the first edge 8. As shown in FIG. 3, it is assumed that a first line segment 11 is drawn on the first tapered surface 5 at the tip of the wiper blade that contacts the member to be cleaned, parallel to the first edge 8 and at a distance of 10 μm from the first edge 8. The length of the first line segment is L1. 4 is an enlarged view of the vicinity of the first line segment 11. As shown in FIG. 4, points (1 / 8)L1, (1 / 2)L1, and (7 / 8)L1 from one end side on the first line segment 11 are designated as P0, P1, and P2, respectively. At this time, three rectangular observation areas 12 are set on the first tapered surface 5, with the centers of gravity being points P0, P1, and P2 on the first line segment 11, one side being 70 μm long and parallel to the first line segment, and one side being 10 μm long and perpendicular to the first line segment.

[0014] FIG. 5 shows an enlarged view of the vicinity of the observation area 12 with P0 as the center of gravity. As with P0 in Figure 5, including P1 and P2, the elastic modulus of the first tapered surface was measured at 70,000 points at a pitch (interval) of 0.1 μm for each of the three observation areas using a scanning probe microscope (hereinafter referred to as SPM). The average value of the elastic modulus values ​​of the 210,000 samples obtained is 15 MPa to 470 MPa, and the coefficient of variation of the elastic modulus is 17.6% or less.

[0015] Similarly to the measurement on the first tapered surface, it is assumed that a second line segment is drawn on the second tapered surface 6 at the tip of the wiper blade that contacts the member to be cleaned, parallel to the second edge 9 and at a distance of 10 μm from the second edge 9. The length of the second line segment is L2. The points (1 / 8)L2, (1 / 2)L2, and (7 / 8)L2 from one end side on the second line segment are designated as P3, P4, and P5, respectively. At this time, three rectangular observation areas are set on the second tapered surface 6, with the centers of gravity being points P3, P4, and P5 on the second line segment, one side being 70 μm long and parallel to the second line segment, and one side being 10 μm long and perpendicular to the second line segment. The elastic modulus of the second tapered surface was measured at 70,000 points at a pitch (interval) of 0.1 μm for each of the three observation regions using an SPM. The average value of the elastic modulus values ​​obtained for a total of 210,000 samples is 15 MPa or more and 470 MPa or less, and the coefficient of variation is 17.6% or less.

[0016] The behavior of the reciprocating wiper blade during cleaning was observed in detail. As a result, it was confirmed that the wiper blade contacts the object to be cleaned in a region of the first tapered surface and the second tapered surface, including a position about 10 μm from the first edge and the second edge, respectively. Furthermore, the wiper blade according to the present disclosure can prevent incomplete wiping or uneven wiping in the wiping portion of the object to be cleaned by satisfying predetermined specifications for the average value of the elastic modulus and its coefficient of variation in the longitudinal direction of the region that can form the contact portion with the object to be cleaned.

[0017] In one embodiment of the wiper blade of the present disclosure, the average value of the elastic modulus measured at predetermined locations in the longitudinal direction of the first tapered surface and the second tapered surface, which may form the contact portion that contacts the member to be cleaned, at positions 10 μm from the first edge and the second edge, respectively, is 15 MPa or more and 470 MPa or less, and the coefficient of variation of the elastic modulus is 17.6% or less. The average value of the elastic modulus is preferably 32 MPa or more and 62 MPa or less. The coefficient of variation of the elastic modulus is preferably 6.0% or less. Since a smaller coefficient of variation of the elastic modulus is preferable, there is no particular lower limit, but it may be, for example, 0.1% or more.

[0018] When the average value of the elastic modulus is within the above range, a portion of the tapered surface can be brought into contact with the object to be cleaned over a narrow width along the longitudinal direction of the wiper blade during cleaning. In other words, the contact portion can be brought into close to a line contact, and the pressing force is concentrated at the contact portion, so that the deposits can be reliably scraped off from the object to be cleaned, rather than simply wiped or spread. As a result, extremely high wiping performance can be achieved compared to conventional wiper blades. Furthermore, a coefficient of variation in the elastic modulus of 17.6% or less means that the elastic modulus of the contact portion of the tapered surface is more uniform or more homogeneous in its longitudinal direction. Therefore, the wiper blade can be brought into contact with the object to be cleaned over a narrow width along its longitudinal direction. As a result, the cleaning surface of the wiper blade does not undulate or become disordered in the longitudinal direction during cleaning, suppressing the occurrence of chattering and achieving uniform followability and contact with the object to be cleaned. As a result, the wiper blade has excellent wiping performance over the entire longitudinal direction, without leaving any residue or uneven wiping even when it comes to highly adhesive dirt such as dust and oil film adhering to the object to be cleaned. can be stably demonstrated.

[0019] The coefficient of variation of the elastic modulus is calculated by the following formula (1). Formula (1): Coefficient of variation (%) = standard deviation / average value of elastic modulus × 100

[0020] For example, when a wiper blade is pressed against a member to be cleaned using the measurement standards for an automobile, in the case of a conventional wiper blade for a vehicle, the contact angle near the contact point is approximately 25°, the width of the contact point with the member to be cleaned (nip width) is 20 to 30 μm, and the maximum contact pressure is 1.5 MPa. On the other hand, the wiper blade of the present disclosure has a contact angle of approximately 55°, a nip width of 5 to 6 μm, and a contact pressure of 6.0 MPa.

[0021] FIG. 6 is a schematic diagram showing the vicinity of the contact point between the wiper blade and the member to be cleaned. As shown in Figure 6(a), it has been confirmed that the tapered surface of a conventional wiper blade contacts the member to be cleaned in a belly contact state (surface contact).On the other hand, as shown in Figure 6(b), it is believed that the tapered surface of the wiper blade of the present disclosure contacts the member to be cleaned in an edge-to-edge contact state close to line contact.

[0022] The material constituting the tapered portion is not particularly limited as long as it can satisfy the above-mentioned requirements for the average value of the elastic modulus and the coefficient of variation of the elastic modulus at positions in the vicinity of 10 μm from the first edge and the second edge of the first tapered surface and the second tapered surface, which may be the contact portions that come into contact with the member to be cleaned. Specifically, for example, the tapered portion preferably contains polyurethane, which has excellent mechanical properties and can easily satisfy the above-mentioned requirements for the average value of the elastic modulus and the coefficient of variation. The polyurethane is preferably a polyurethane elastomer. Polyurethane elastomers are obtained mainly from raw materials such as polyols, chain extenders, polyisocyanates, catalysts, and other additives. The polyurethane elastomer is a block copolymer consisting of hard segments and soft segments. The hard segments are generally composed of polyisocyanates and chain extenders containing short-chain diols. On the other hand, the soft segments are generally composed of long-chain polyols such as polyester polyols, polyether polyols, and polycarbonate polyols and polyisocyanates.

[0023] In order to achieve the above-mentioned specifications regarding the average value of the elastic modulus and the coefficient of variation of the elastic modulus, for example, the properties of the block copolymer comprising the hard segment and the soft segment can be utilized. Conventional polyurethanes have hard segments formed by further aggregation of urethane bond aggregations due to interactions. The aggregated urethane bond segments further aggregate to form relatively large hard segments. Therefore, according to the inventors' studies, wiper blades manufactured using such polyurethanes do not satisfy at least one of the average elastic modulus value and the coefficient of variation of the elastic modulus according to the present disclosure. That is, because conventional polyurethanes have relatively large hard segments, it is difficult to achieve the coefficient of variation of the elastic modulus of 17.6% or less at 210,000 locations measured using a scanning probe microscope according to the present disclosure. Here, it is thought that polyurethanes with a low amount of hard segments themselves may suppress further aggregation of the aggregated urethane bonds, thereby reducing the coefficient of variation. However, in such cases, it is difficult to achieve an average elastic modulus value of 15 MPa or more.

[0024] A tapered portion satisfying the physical properties of the present disclosure can be formed, for example, by using polyurethane in which hard segments are finely and uniformly dispersed. Such polyurethane is described below. In other words, diisocyanates and polyfunctional isocyanates with three or more functional groups are used as urethane raw materials. By using the copolymer and the diol or tri- or higher functional alcohol in an appropriate concentration range, aggregation of the hard segments is suppressed, and a polyurethane in which the hard segments are finely and uniformly dispersed can be obtained.

[0025] Specifically, for example, it is preferable to use at least one of an alcohol containing a tri- or higher functional polyfunctional alcohol and an isocyanate compound containing a tri- or higher functional polyfunctional isocyanate as the urethane raw material. It is also preferable to use, as urethane raw materials, an alcohol containing at least one selected from diols and tri- or higher functional alcohols, and an isocyanate compound containing tri- or higher functional isocyanate. It is also preferable to use, as urethane raw materials, an alcohol containing a tri- or higher functional polyfunctional alcohol and an isocyanate compound containing a diisocyanate and a tri- or higher functional polyfunctional isocyanate. In particular, it is preferable to use a tri- or higher functional polyfunctional isocyanate and a tri- or higher functional polyfunctional alcohol as the urethane raw material.

[0026] Polyurethanes obtained as reaction products of tri- or higher functional isocyanates and tri- or higher functional alcohols have steric hindrance that suppresses molecular orientation and more reliably suppresses aggregation of hard segments, making them suitable for achieving the elastic modulus and coefficient of variation of the present disclosure. Furthermore, when the soft segment portion has, for example, a linear alkylene structure, the soft segments stack together, increasing crystallinity. As a result, the hard segments also become difficult to disperse. Therefore, introducing an alkylene structure with a side chain into the soft segment portion is also effective in suppressing the aggregation of the hard segments. Specifically, for example, introducing a partial structure such as that shown in the following structural formulas (i) to (iv) into the soft segment portion between two urethane bonds is effective in miniaturizing the hard segments. -CH2-CH(CH3)-CH2-CH2-O- (i) -CH2-CH2-CH(CH3)-CH2-O- (ii) -CH2-CH(CH3)-O- (iii) -CH(CH3)-CH2-O- (iv)

[0027] The structures of structural formulas (i) and (ii) are substantially identical to each other and are generated by ring-opening polymerization of 3-methyltetrahydrofuran. Furthermore, the structures of structural formulas (iii) and (iv) are substantially identical to each other and are generated by ring-opening polymerization of 1,2-propylene oxide. Urethane resins having these structures between two adjacent urethane bonds can be obtained by reacting a polyether polyol or polyester polyol having these structures with an isocyanate. When a bifunctional alcohol (diol) and a bifunctional isocyanate (diisocyanate) are used as urethane raw materials, it is usually difficult to finely disperse the hard segments. However, by introducing the above partial structure into the soft segment, it is possible to finely disperse the hard segments, even when a diol and a diisocyanate are used as urethane raw materials. As a result, a polyurethane can be obtained that provides a wiper blade that satisfies the parameters of the present disclosure.

[0028] In addition to introducing a side chain into the soft segment portion as described above, another method for suppressing crystallization due to stacking of soft segments and preventing aggregation of hard segments is to use two or more alcohols with different numbers of carbon atoms in the linear chain portion as the alcohol of the urethane raw material. Polyurethane obtained by using two or more alcohols with different numbers of carbon atoms in the linear chain portion can suppress crystallization due to stacking of soft segments due to the difference in carbon numbers, even if the polyurethane has a linear alkylene structure in the soft segment portion. Furthermore, by varying the number of carbon atoms in the soft segment portions, aggregation of the urethane bond portions is suppressed, thereby preventing aggregation of the hard segments. Therefore, even when a diol and a diisocyanate having a linear alkylene structure in the molecule are used as urethane raw materials, the hard segments can be made finer by using multiple types of diols with different numbers of carbon atoms in the linear alkylene structure as the diol. As a result, a polyurethane can be obtained that provides a wiper blade that satisfies the parameters of the present disclosure. An example of multiple types of diols is the combined use of polybutylene adipate polyester polyol and polyhexylene adipate polyester polyol.

[0029] Examples of the alcohol include the following: Polyester polyols such as polyethylene adipate polyester polyol, polybutylene adipate polyester polyol, polyhexylene adipate polyester polyol, (polyethylene / polypropylene) adipate polyester polyol, (polyethylene / polybutylene) adipate polyester polyol, and (polyethylene / polyneopentylene) adipate polyester polyol; polycaprolactone-based polyols obtained by ring-opening polymerization of caprolactone; polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol; and polycarbonate diols. These can be used alone or in combination of two or more.

[0030] As mentioned above, it is preferable to use two or more polyols with different numbers of carbon atoms in the linear portion (alkylene chain) as the alcohol, because this suppresses crystallization of the soft segment and allows for the production of a urethane in which aggregation of the hard segment is suppressed. In this case, it is preferable to use at least two selected from the group consisting of polyester polyols such as polyethylene adipate polyester polyol, polybutylene adipate polyester polyol, polyhexylene adipate polyester polyol, (polyethylene / polypropylene) adipate polyester polyol, (polyethylene / polybutylene) adipate polyester polyol, and (polyethylene / polyneopentylene) adipate polyester polyol.

[0031] As the chain extender, diols capable of extending the polyurethane elastomer chain and polyfunctional alcohols having three or more functional groups can also be used. Examples of diols include the following: Ethylene glycol (EG), diethylene glycol (DEG), propylene glycol (PG), dipropylene glycol (DPG), 1,4-butanediol (1,4-BD), 1,6-hexanediol (1,6-HD), 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, xylylene glycol (terephthalyl alcohol), triethylene glycol. These can be used alone or in combination of two or more.

[0032] Examples of trifunctional or higher polyfunctional alcohols include trimethylolpropane (TMP), glycerin, pentaerythritol, and sorbitol, which can be used alone or in combination of two or more.

[0033] One method for improving the elastic modulus of polyurethane elastomers is to introduce a crosslinked structure. A preferred method for introducing crosslinks is to use a tri- or higher-functional polyfunctional alcohol as the chain extender. The introduction of a branched structure into polyurethane by using a tri- or higher-functional polyfunctional alcohol can suppress the crystallization of polyurethane and further suppress the aggregation of hard segments. A trifunctional alcohol is used as the polyfunctional alcohol from the viewpoint of suppressing an excessive increase in hardness due to an excessively high degree of crosslinking of polyurethane. It is preferable to use triols. Among them, triols, which have a methylene skeleton next to the hydroxyl group and can form a flexible crosslinked structure in terms of molecular structure, are preferable because they have an even greater effect of suppressing the crystallinity of the hard segment. Examples of such triols include trimethylolpropane (TMP) and glycerin.

[0034] Examples of the isocyanate compound include the following: 4,4'-Diphenylmethane Diisocyanate (4,4'-MDI), Polymeric MDI, 2,4-Tolylene Diisocyanate (2,4-TDI), 2,6-Tolylene Diisocyanate (2,6-TDI), Xylene Diisocyanate (XDI), 1,5-Naphthylene Diisocyanate (1,5-NDI), p-Phenylene Diisocyanate (PPDI), Hexamethylene Diisocyanate (HDI), Isophorone Diisocyanate (IPDI), 4,4'-Dicyclohexylmethane Diisocyanate (Hydrogenated MDI), Tetramethylxylene Diisocyanate (TMXDI), Carbodiimide-Modified MDI, Triphenylmethane-4,4',4''-Triisocyanate (TTI), Tris(phenylisocyanate)thiophosphate (TPTI).

[0035] Among these, 4,4'-MDI is preferred because the two isocyanate groups have equal reactivity and provide high mechanical properties. It is also preferable to use a tri- or higher-functional polyfunctional isocyanate in combination. The use of a tri- or higher-functional polyfunctional isocyanate allows for the introduction of a branched structure into the polyurethane, which is effective in further suppressing aggregation of hard segments. Furthermore, a denser crosslinked structure can be introduced into the polyurethane, which can more stably contact the elastic portion with the object to be cleaned. As a result, incomplete wiping and uneven wiping of the object to be cleaned can be more effectively suppressed.

[0036] The trifunctional or higher polyfunctional isocyanate may be at least one selected from the group consisting of triphenylmethane-4,4',4''-triisocyanate (TTI), tris(phenylisocyanate)thiophosphate (TPTI), and polymeric MDI. Among these, tris(phenylisocyanate)thiophosphate (TPTI) and polymeric MDI are more preferably used. These isocyanates have methylene groups or ether groups between multiple NCO groups, allowing the distance between multiple urethane bonds to be appropriately maintained. This is therefore advantageous in suppressing aggregation of hard segments.

[0037] Here, polymeric MDI is represented by the following chemical formula (1) and chemical formula (1)'. In chemical formula (1)', n is preferably 1 or more and 4 or less. Chemical formula (1) is the case where n is 1 in chemical formula (1)'.

[0038] [ka]

[0039] When the tapered portion according to the present disclosure contains polyurethane that is a reaction product of a raw material composition that contains an isocyanate compound including a diisocyanate and a tri- or higher functional isocyanate, and an alcohol including a tri- or higher functional alcohol, the tapered portion preferably has the following physical properties:

[0040] That is, suppose that a line segment is drawn on the first tapered surface and the second tapered surface of the tapered portion, parallel to the first edge and the second edge, respectively, at a distance of 0.5 mm from the first edge and the second edge. The length of the line segment is L', and the points 1 / 8L', 1 / 2L', and 7 / 8L' from one end of the line segment are P0', P1', and P2', respectively. The samples sampled at P0', P1', and P2' of the first and second tapered surfaces are heated and vaporized in an ionization chamber, and the sample molecules are ionized using a direct sample introduction mass spectrometer. The temperature is increased at a rate of 10°C / s to 1,000°C. The resulting detected amount of all ions is designated M1, and the integrated intensity of the peak in the extracted ion thermogram corresponding to the m / z range derived from the trifunctional or higher polyfunctional isocyanate is designated M2. In this case, M2 / M1 on the first and / or second tapered surfaces is preferably 0.0010 to 0.0150, and more preferably 0.0030 to 0.0150.

[0041] Furthermore, when M3 is the integrated intensity of the peak in the extracted ion thermogram corresponding to the range of m / z values ​​derived from the diisocyanate, M3 / M1 on the first tapered surface and / or the second tapered surface is preferably 0.0200 to 0.1100, and more preferably 0.0380 to 0.0760. By having M2 / M1 and M3 / M1 within the above ranges, the polyurethane incorporates an appropriate amount of a structure derived from a trifunctional or higher functional isocyanate, which has low crystallinity. This suppresses aggregation of the hard segments, resulting in finer and more uniform dispersion of the hard segments. Furthermore, excessive development of crosslinked structures in the polyurethane is suppressed, and the average elastic modulus can be more easily adjusted to a range of 15 MPa or more and 470 MPa or less.

[0042] Furthermore, it is preferable that M2 / M3 is 0.0130 or more and 0.3000 or less. M2 / M3 is a parameter that represents the ratio of the structural portion derived from diisocyanate to the structural portion derived from trifunctional or higher polyfunctional isocyanate in the isocyanate-derived structure of the polyurethane. By setting M2 / M3 within the above range, an excessive increase in the elastic modulus can be suppressed and a polyurethane in which aggregation of hard segments is further suppressed can be obtained.

[0043] Here, when the polyurethane is a polyurethane produced using polymeric MDI represented by the above chemical formula (1)' as a tri- or higher functional polyfunctional isocyanate, M2 may be the sum of the integrated intensities of peaks in the extracted ion thermogram obtained by the above mass spectrometry, where the m / z value due to n=1 in the structure represented by chemical formula (1)' is in the range of 380.5 to 381.5, the m / z value due to n=2 is in the range of 511.5 to 512.5, the m / z value due to n=3 is in the range of 642.5 to 643.5, and the m / z value due to n=4 is in the range of 773.5 to 774.5.

[0044] Furthermore, when the polyurethane is one in which 4,4'-MDI represented by chemical formula (2) is used as one of the raw materials as a diisocyanate, M3 may be defined as the integrated intensity of a peak corresponding to an m / z value in the range of 249.5 to 250.5 derived from the structure represented by chemical formula (2) in the ion thermogram obtained by the above-described mass spectrometry. [ka]

[0045] Furthermore, when the tapered portion of the wiper blade according to one embodiment of the present disclosure includes polyurethane, which is a reaction product of a raw material composition including an isocyanate compound containing a trifunctional or higher polyfunctional isocyanate and an alcohol containing a trifunctional or higher polyfunctional alcohol, the tapered portion preferably has the following physical properties: Assuming that a line segment is drawn on the first and second tapered surfaces of the tapered portion parallel to the first and second edges, respectively, and 0.5 mm away from the first and second edges, the length of the line segment is L', and points 1 / 8L', 1 / 2L', and 7 / 8L' from one end of the line segment are designated P0', P1', and P2', respectively. Samples taken at P0', P1', and P2' on the first and second tapered surfaces are measured by pyrolysis GC / MS (gas chromatography and mass spectrometry). The concentration of the component derived from a trifunctional or higher polyfunctional alcohol in the polyurethane is preferably 0.04 mmol / g to 0.39 mmol / g, more preferably 0.14 mmol / g to 0.39 mmol / g, and even more preferably 0.22 mmol / g to 0.39 mmol / g.

[0046] When the concentration of the tri- or higher functional alcohol-derived component is 0.04 mmol / g or higher, the polyurethane can be one in which aggregation of hard segments is more reliably suppressed. Furthermore, when the concentration of the tri- or higher functional alcohol-derived component is 0.39 mmol / g or lower, excessive development of crosslinked structures in the polyurethane can be suppressed, preventing the modulus of elasticity from becoming too high. Therefore, a tapered portion having the above physical properties can more easily satisfy the requirements for the average modulus of elasticity (15 to 470 MPa) and the coefficient of variation of the modulus of elasticity (17.6% or lower). The concentration of the tri- or higher functional alcohol in the polyurethane can be calculated using the following formula (2):

[0047] Equation (2): Concentration of trifunctional or higher polyfunctional alcohol (mmol / g) = [Amount of tri- or higher functional alcohol (g) / Molecular weight of tri- or higher functional alcohol x 1000] / [Mass of polyurethane (g)]

[0048] The urethane raw material contains a catalyst to promote the reaction of isocyanate compounds and alcohol. The catalyst may contain a catalyst commonly used for curing polyurethane elastomers, such as a tertiary amine catalyst. Specific examples include: amino alcohols such as dimethylethanolamine, N,N,N'-trimethylaminopropylethanolamine, and N,N'-dimethylhexanolamine; trialkylamines such as triethylamine; tetraalkyldiamines such as N,N,N'N'-tetramethyl-1,3-butanediamine; triethylenediamine, piperazine compounds, and triazine compounds. Organic acid salts of metals such as potassium acetate and potassium alkali octylate may also be used. Furthermore, metal catalysts typically used in urethanization, such as dibutyltin dilaurate, may also be used. These may be used alone or in combination of two or more.

[0049] The raw material constituting the tapered portion of the wiper blade may contain additives such as pigments, plasticizers, waterproofing agents, antioxidants, ultraviolet absorbers, and light stabilizers, as needed, within a range that does not affect the elastic modulus and its coefficient of variation.

[0050] <Surface treatment> The tapered portion of the wiper blade may be surface-treated. Preferred surface treatment methods in the present disclosure include, for example, (i) a method including a step of irradiating an object to be treated with ultraviolet light, and (ii) a method including a step of applying a material for forming a hardened region to the object to be treated and hardening the material.

[0051] (i) The conditions for irradiating ultraviolet light are not particularly limited. The ultraviolet light may have a wavelength of 400 nm or less, but preferably 200 nm or more. A wavelength of 200 nm or more can effectively increase the elastic modulus. The wavelength of the maximum emission peak of the light emitted by the light source is preferably 200 nm or more and 400 nm or less. It is particularly preferable that the wavelength of the maximum emission peak be near 254 nm, for example, in the range of 254±1 nm. This is because ultraviolet light in the above wavelength range or with the above wavelength can efficiently generate active oxygen that modifies the surface of the tapered portion of the wiper blade. When there are multiple ultraviolet light emission peaks, it is preferable that one of them be near 254 nm.

[0052] The intensity of light emitted from the light source is not particularly limited, and values ​​measured using a spectroradiometer (trade name: USR-40V / D, manufactured by Ushio Inc.), an ultraviolet integrating actinometer (trade name: UIT-150-A, UVD-S254, VUV-S172, VUV-S365, manufactured by Ushio Inc.), or the like can be used. The integrated amount of ultraviolet light irradiated to the tapered portion of the wiper blade in the surface treatment step may be appropriately selected depending on the effect of the surface treatment to be obtained. This can be determined by adjusting the irradiation time of light from the light source, the output of the light source, the distance from the light source, and the like, and may be, for example, 10,000 mJ / cm. 2 It is sufficient to determine the amount of light so as to obtain the desired cumulative amount of light.

[0053] The cumulative amount of ultraviolet light irradiated onto the tapered portion of the wiper blade can be calculated by the following method. UV cumulative light intensity (mJ / cm 2 ) = UV intensity (mW / cm 2 ) x irradiation time (sec)

[0054] As a light source that emits ultraviolet light, for example, a high-pressure mercury lamp or a low-pressure mercury lamp can be suitably used. These light sources are preferred because they can stably emit ultraviolet light of a suitable wavelength that is little attenuated over the irradiation distance and can uniformly irradiate the entire surface.

[0055] (ii) The conditions for applying and curing the material for forming the hardened region are not particularly limited. The hardened region in the tapered portion can be formed by applying and curing the material for forming the hardened region. This treatment can effectively increase the modulus of elasticity of the hardened portion by applying the material for forming the hardened region. It is preferable that the hardened region is formed on at least both the first tapered surface and the second tapered surface of the lip portion that come into contact with the member to be cleaned.

[0056] The material for forming the hardened region is diluted with a diluent solvent as needed and can be applied by known means such as dipping, spraying, using a dispenser, brushing, or roller coating. Furthermore, after applying the material for forming the hardened region, a further treatment such as heat treatment may be performed. The material for forming the hardened region may be impregnated into the polyurethane contained in the elastic member. Since impregnation is promoted by making the material for forming the hardened region high-concentration and low-viscosity, the material for forming the hardened region may be heated and impregnated without dilution. The degree of hardening may be adjusted by the temperature of the material for forming the hardened region, the impregnation or immersion time, the temperature and time of heat treatment after impregnation or immersion, and the subsequent standing time.

[0057] The temperature of the material for forming the cured region should be about 60°C to 90°C. The impregnation or immersion time is preferably about 10 to 180 seconds, although this cannot be generalized. After applying the material for forming the cured region to the cured region, a heat treatment may be carried out. The heat treatment reduces the viscosity of the material for forming the cured region present on the surface of the polyurethane, facilitating its penetration and diffusion into the polyurethane.

[0058] The heating method includes, but is not limited to, passing the material through a heating furnace, blowing heated air onto the material, etc. For example, the heating furnace may be a radiation heating furnace or a circulating air heating furnace, and the device for generating heated air may be a hot air blower or a far-infrared heater. The cured region can be widened by using a higher temperature and / or a longer heating time. As for the heating conditions, the surface temperature of the treated surface is preferably set to, for example, 90° C. to 110° C. Furthermore, the heating time is preferably set to, for example, 10 minutes to 60 minutes.

[0059] Furthermore, the amount of residual isocyanate during polyurethane molding tends to gradually decrease over time after molding. Therefore, the formation of the cured region should be carried out promptly after polyurethane molding, but is not particularly limited. For example, it is recommended to carry out the formation within 3 hours. The amount of residual isocyanate can also be adjusted by the mixing ratio of the composition used during polyurethane formation.

[0060] The material for forming the hardened region is not particularly limited as long as it is capable of hardening polyurethane or forming a hardened region on the surface of polyurethane. Examples of the material include an isocyanate compound and an acrylic compound. The material for forming the cured region may be diluted with a solvent or the like. The solvent used for dilution is not particularly limited as long as it dissolves the material used, and examples thereof include toluene, xylene, butyl acetate, methyl isobutyl ketone, and methyl ethyl ketone.

[0061] When the tapered portion of the wiper blade is made of polyurethane, it is preferable to use an isocyanate compound, which is a polyurethane constituent material, as the material for forming the cured region, taking into consideration compatibility with the tapered portion material and impregnation ability. The isocyanate compound can be one having one or more isocyanate groups in the molecule.

[0062] As the isocyanate compound having one isocyanate group in the molecule, an aliphatic monoisocyanate such as octadecyl isocyanate (ODI), an aromatic monoisocyanate such as phenyl isocyanate (PHI), or the like can be used. As an isocyanate compound having two isocyanate groups in the molecule, polyisocyanate is usually used. Those used in the production of urethane resins can be used, specifically, the following can be mentioned: 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4'-diphenylmethane diisocyanate (MDI), m-phenylene diisocyanate (MPDI), tetramethylene diisocyanate (TMDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), etc.

[0063] Furthermore, examples of isocyanate compounds having three or more isocyanate groups in the molecule include 4,4',4"-triphenylmethane triisocyanate, 2,4,4'-biphenyl triisocyanate, and 2,4,4'-diphenylmethane triisocyanate. In addition, modified derivatives and polymers of isocyanate compounds having two or more isocyanate groups can also be used. To efficiently increase the elastic modulus of the cured region, MDI with high crystallinity, i.e., MDI with a symmetric structure, is preferred. Furthermore, MDI containing modified compounds is liquid at room temperature, making it easy to work with.

[0064] <Wiper blade manufacturing method> The method for manufacturing a wiper blade is not particularly limited and can be selected from known methods. For example, a lip portion having a tapered portion can be obtained by injecting, for example, a polyurethane elastomer raw material composition into a cavity in a wiper blade mold and heating and curing it. The tip of the tapered portion may be cut to form a shape. This is preferable because it allows the first edge and the second edge to be molded with high smoothness. Alternatively, a wiper blade may be manufactured by producing a pair of tandem-shaped molded bodies formed with tapered portions abutting each other and cutting them longitudinally. The blade support portion and neck may be manufactured using conventionally known materials and manufacturing methods.

[0065] <The entire process, including the wiper arm> The wiper blade of the present disclosure can be used in various types of wiper devices, such as tandem and opposing wiping types. [Example]

[0066] The present disclosure will be described below with reference to Production Examples, Examples, and Comparative Examples, but the present disclosure is not limited to these Examples. Reagents or industrial chemicals were used as raw materials other than those indicated in the Examples and Comparative Examples. Note that "parts" in the Examples and Comparative Examples are all by mass unless otherwise specified.

[0067] In the examples and comparative examples, wiper blades were manufactured and evaluated. The formulations and evaluation results of the examples and comparative examples are shown in Tables 3 to 9.

[0068] Example 1 <Preparation of raw materials for wiper blades> 352.6 g of 4,4'-diphenylmethane diisocyanate (trade name: Millionate MT, manufactured by Tosoh Corporation) (hereinafter referred to as 4,4'-MDI, and simply referred to as "MDI" in the table), 10.0 g of triphenylmethane-4,4',4''-triisocyanate (trade name: Ultite Super CA, manufactured by Toho Chemical Industry Co., Ltd.) (hereinafter referred to as TTI) as a trifunctional or higher polyfunctional isocyanate, 637.4 g of polybutylene adipate polyester polyol (trade name: Nipporan 3027, manufactured by Tosoh Corporation) (hereinafter referred to as PBA2500) having a number average molecular weight of 2500 was reacted at 80° C. for 3 hours to obtain a prepolymer having an NCO content of 10.0 mass %.

[0069] Next, the components in Table 1 below were mixed to prepare a curing agent. [Table 1]

[0070] This curing agent was added to the prepolymer and mixed to obtain a raw material composition. This raw material composition was poured into a mold for forming a wiper blade and cured at 130°C for 2 minutes. The mold was then demolded to obtain a polyurethane molded product. The inside of the mold for forming a wiper blade had been coated with release agent A in advance. Release agent A was a mixture of the materials listed in Table 2 below. [Table 2] The lip tip of the obtained polyurethane molded article was cut to obtain a wiper blade according to this example. The distances in the thickness direction and the length direction of the lip tip were 0.6 mm and 450 mm, respectively. The obtained wiper blade was evaluated by the following method.

[0071] [Method for measuring polyfunctional alcohol species and concentration] Polyfunctional alcohols were detected by pyrolysis GC / MS (gas chromatography and mass spectrometry) under the following measurement conditions: Sampling position: Assuming that a line segment is drawn parallel to the first edge and the second edge on the first tapered surface and the second tapered surface of the tapered portion, respectively, with a distance of 0.5 mm from the first edge and the second edge, the length of the line segment is L', and one end side of the line segment The points 1 / 8L', 1 / 2L', and 7 / 8L' were designated as P0', P1', and P2', respectively. The samples taken at P0', P1' and P2' of the first tapered surface and the second tapered surface were measured by the following method. For sampling, a member such as polyurethane was cut out with a biocutter. Device: Thermal decomposition equipment: Product name: EGA / PY-3030D, manufactured by Frontier Labs Gas chromatography equipment: TRACE1310 gas chromatograph, Thermo Fisher Scientific Mass spectrometer: ISQLT, manufactured by Thermo Fisher Scientific ·Thermal decomposition temperature: 500℃ GC column: 0.25mm inner diameter x 30m stainless steel capillary column Stationary phase: 5% phenylpolydimethylsiloxane Heating conditions: Hold at 50°C for 3 minutes, then heat to 300°C at 8°C / min. ·MS conditions: Mass number range m / z10~650 Scan speed: 1 second / scan

[0072] The polyfunctional alcohol species were characterized by GC / MS. A calibration curve was created by GC analysis of known concentrations of the characterized polyfunctional alcohol species, and quantification was performed from the GC peak area ratio. The arithmetic mean values ​​of the values ​​obtained from the samples P0', P1', and P2' of the first tapered surface and the second tapered surface were used as the polyfunctional alcohol concentrations of the first tapered surface and the second tapered surface, respectively.

[0073] [Measurement of M1, M2 and M3] Measurements of M1 to M3 were carried out using the direct sample introduction method (DI method), in which the sample was introduced directly into the ion source without passing through a gas chromatograph (GC). The equipment used was an ion trap GC / MS (trade name: POLARIS Q, Thermof A direct exposure probe (DEP) was used as the direct introduction probe. Assuming that a line segment is drawn on the first tapered surface and the second tapered surface of the tapered portion, parallel to the first edge and the second edge, respectively, with a distance of 0.5 mm from the first edge and the second edge, the length of the line segment is L', and the points 1 / 8L', 1 / 2L', and 7 / 8L' from one end side on the line segment are designated as P0', P1', and P2', respectively. The samples taken at P0', P1' and P2' of the first tapered surface and the second tapered surface were measured by the following method. For sampling, a member such as polyurethane was cut out with a biocutter. Approximately 0.1 μg of the sample sampled at each of the P0′, P1′, and P2′ points on the first and second tapered surfaces was fixed to a filament at the tip of the probe and directly inserted into the ionization chamber. The sample was then rapidly heated from room temperature to 1000°C at a constant heating rate (approximately 10°C / s), and the vaporized gas was detected by a mass spectrometer.

[0074] The detected amount M1 of all ions is the sum of the integrated intensities of all peaks in the obtained total ion current thermogram, When the sum of the integrated intensities of the peaks in the extracted ion thermogram of the m / z values ​​derived from the trifunctional or higher polyfunctional isocyanate is defined as M2, (M2 / M1) was calculated using the values ​​of M1 and M2. When the sum of the integrated intensities of the peaks in the extracted ion thermogram of the m / z values ​​derived from the diisocyanate is defined as M3, (M3 / M1) was calculated using the values ​​of M1 and M3. Then, the arithmetic mean values ​​of the values ​​obtained from the samples of P0', P1', and P2' of the first tapered surface and the second tapered surface were used as the arithmetic mean values ​​of the values ​​obtained from the samples of P0', P1', and P2' of the first tapered surface and the second tapered surface. The values ​​of (M2 / M1) and (M3 / M1) were taken as the respective values ​​of the second tapered surface.

[0075] In this example, TTI used as the trifunctional or higher polyfunctional isocyanate has a structure represented by the following chemical formula (3). In the extracted ion thermogram obtained in this evaluation, a peak derived from the cationized product of TTI was detected, with a peak top at m / z 366.5 to 367.5. Therefore, in this example, the integrated intensity of this peak was designated M2.

[0076] [ka]

[0077] In other examples described later, for an elastic portion made of polyurethane synthesized using polymeric MDI as a tri- or higher functional isocyanate, peaks derived from cationized polymeric MDI were detected in the extracted ion thermogram obtained in this evaluation, with peaks having peak tops at m / z values ​​in the range of 380.5 to 381.5 indicating n = 1 in the structure represented by chemical formula (1)', m / z values ​​in the range of 511.5 to 512.5 indicating n = 2, m / z values ​​in the range of 642.5 to 643.5 indicating n = 3, and m / z values ​​in the range of 773.5 to 774.5 indicating n = 4. Therefore, in these examples, the sum of the integrated intensities of these peaks was defined as M2.

[0078] Similarly, in the examples described below, tris(phenylisocyanate)thiophosphate (TPTI) used as a trifunctional or higher polyfunctional isocyanate has a structure represented by chemical formula (4). In the extracted ion thermogram obtained in this evaluation, a peak derived from the cationized product of TPTI was detected, with a peak top at m / z 464.5 to 465.5. Therefore, in these examples, the integrated intensity of this peak was designated M2.

[0079] [ka]

[0080] On the other hand, in the case of 4,4'-MDI, which is a diisocyanate, When the m / z of the structure represented by the chemical formula (2) was in the range of 249.5 to 250.5, the structure represented by the chemical formula (2) was detected as a cationized structure. The integrated intensity of the peak in the extracted ion thermogram corresponding to this structure was designated as (M3).

[0081] [Method for measuring elastic modulus] The elastic modulus was measured by SPM using a scanning probe microscope (SPM) (trade name: MFP-3D-Origin, manufactured by Oxford Instruments) using the following method. First, samples were prepared as follows. For the obtained wiper blade, a first edge formed by the first tapered surface and the tip surface was set as shown in FIG. 3. A first line segment with a length L1 was drawn parallel to the first edge, with a distance of 10 μm from the first edge. Three 2 mm square measurement samples with one side parallel to the first line segment were cut out, with the centers of gravity set at points P0, P1, and P2, respectively, at 1 / 8L, 1 / 2L, and 7 / 8L from one end of the line segment. Next, a 100 μm square, 1 μm thick polyurethane slice was cut out from each measurement sample at −50°C using a cryomicrotome (UC-6 (product name), manufactured by Leica Microsystems). The center of gravity was set at P0, P1, or P2, with one side parallel to the first line segment. Three measurement samples were prepared in this manner. Each of the obtained measurement samples was placed on a smooth silicon wafer and left to stand for 24 hours in an environment at room temperature of 25°C and humidity of 50%.

[0082] Next, the silicon wafer with the measurement sample mounted on it was set on the SPM stage and observed using the SPM. The spring constant and proportionality constant of the silicon cantilever (product name: OMCL-AC160, manufactured by Olympus, tip curvature radius: 8 nm) were previously confirmed to be as follows using the thermal noise method installed in this SPM device: spring constant: 30.22 nN / nm, proportionality constant: 82.59 nm / V. The cantilever was tuned in advance to determine its resonance frequency (285 KHz (first order) and 1.60 MHz (higher order)). The SPM measurement mode was AM-FM mode, the cantilever free amplitude was 3 V, the set point amplitude was 2 V (first order) and 25 mV (higher order), and the field of view was 70 μm × 70 μm. The scan speed was 1 Hz, and the number of scan points was 256 vertically and 256 horizontally to obtain phase images. The field of view was selected so that P0, P1, and P2 of each measurement sample were located in the center of the field of view and one side was parallel to the first line segment. From the obtained phase image, the locations on the measurement sample where the elastic modulus was measured by force curve measurement were designated. Specifically, as shown in Figures 4 and 5, in the 70 μm × 70 μm phase image, the measurement locations were designated as 70,000 positions corresponding to 70,000 points at a pitch (interval) of 0.1 μm in a rectangular region having the centers of gravity at points P0, P1, and P2, one side of which is 70 μm long and parallel to the first line segment, and the other side of which is 10 μm long and perpendicular to the first line segment.

[0083] After that, a force curve measurement was performed once in contact mode at each point. The force curves were obtained under the following conditions. In the force curve measurement, the piezoelectric element that drives the cantilever is controlled so that it turns back when the deflection reaches a certain value due to the tip of the cantilever coming into contact with the sample surface. The turning point at this time is called the trigger value, and it indicates how much the voltage must increase from the deflection voltage at the start of the force curve to make the cantilever turn back. In this measurement, the trigger value was set to 0.2 V and the force curve measurement was performed. Other force curve measurement conditions were as follows: the distance from the tip position of the cantilever in the standby state to the turning back at the trigger value was 500 nm, and the scan speed was 1 Hz (the speed at which the probe makes one round trip). After that, fitting was performed on each of the obtained force curves based on Hertz theory to calculate the elastic modulus. The elastic modulus according to Hertz theory was (Young's modulus) is calculated using the following formula (*1).

[0084] Calculation formula (*1) F=(4 / 3)E * R 1 / 2 d 3 / 2 where F is the force exerted by the cantilever on the sample at the point where the cantilever turns back, E * is the composite elastic modulus, R is the radius of curvature of the tip of the cantilever (8 nm), and d is the deformation of the sample at the point where the cantilever turns back.

[0085] Then, d was calculated using the following formula (*2). Calculation formula (*2) Calculated as d=Δz-D. Δz is the displacement of the piezoelectric element from when the tip of the cantilever contacts the sample until it bends back, and D is the amount of warping of the cantilever at the point where it bends back. D was calculated using the following formula (*3).

[0086] Calculation formula (*3) D=α·ΔVdeflection In the calculation formula (*3), α is the proportionality constant (Invols constant) of the cantilever, and ΔVdeflection represents the change in deflection voltage from when the cantilever starts to contact the sample to when it turns back.

[0087] Furthermore, F was calculated using the following formula (*4). Calculation formula (*4) F=κ·D κ is the spring constant of the cantilever. Since ΔVdeflection and Δz are actual measured values, E in formula (*1) can be calculated from formulas (*1) to (*4). * Furthermore, the elastic modulus (Young's modulus) Es was calculated using the following formula (*5).

[0088] Calculation formula (*5) 1 / E * =[(1-Vs 2 ) / Es]-[(1-Vi 2 ) / Ei] Vs: Poisson's ratio of the sample (fixed at 0.33 in this example); Vi: Poisson's ratio of the cantilever tip (in this example, the value for silicon is used); Ei: Young's modulus of the cantilever tip (in this example, the value for silicon is used).

[0089] The elastic modulus was measured at 70,000 points at a pitch (interval) of 0.1 μm in both the vertical and horizontal directions in a rectangular observation area (three 10 μm × 70 μm observation areas) with each of the centers of gravity at P0, P1, and P2, one side of which was 70 μm long and parallel to the first line segment, and the other side of which was 10 μm long and perpendicular to the first line segment. The average value of the elastic modulus values ​​calculated from the force curves at a total of 210,000 points was taken as the elastic modulus of the first tapered surface. The standard deviation was calculated from the elastic modulus at a total of 210,000 points. The coefficient of variation of the elastic modulus of the first tapered surface was calculated from the average value and standard deviation of the elastic modulus values ​​using the following formula 1. Formula (1): Coefficient of variation (%) = standard deviation / average value of elastic modulus × 100

[0090] The average value of the elastic modulus of the second tapered surface and the coefficient of variation of the elastic modulus of the second tapered surface were calculated in the same manner as above. The results are shown in Table 3.

[0091] <Evaluation of wiping performance> Using the testing equipment for the wiping performance test described in the Japanese Industrial Standards (JIS) D5710:1998 (Automobile parts - Wiper arms and wiper blades), the wiping performance of the wiper blade was measured. The wiper blade was attached, and silicone oil (product name: KF-96-50cs, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the entire surface to be wiped to simulate an oil film on the glass surface to be cleaned, and cleaning was performed under the following conditions. After one reciprocal wipe of the wiper blade, the remaining part of the glass surface was observed from the back side of the cleaned surface, and the unevenness of gloss and the influence on visibility were visually confirmed. The results were calculated as the ratio of the area of ​​the part where the silicone oil film was removed to the area of ​​the surface wiped by the wiper blade (hereinafter referred to as the silicone oil film removal area rate (%)). The wiping performance was evaluated based on the calculated oil film removal area ratio according to the following criteria. The results are taken as the initial wiping performance. Furthermore, the wiper blade was reciprocated under the durability conditions described below, and after 100,000 and 500,000 reciprocations, the wiping performance after durability was confirmed in the same manner as in the evaluation of the initial wiping performance described above. The results of the initial and post-durability evaluations are shown in Table 3 as the wiping performance of the wiper blade.

[0092] [Wipe-off conditions] Load applied to wiper blade: 10N / m Wiper blade reciprocating speed: 50 times / min [Durability conditions] Water application rate: 100-500 mL / min Wiper blade load: 18N / m Wiper blade reciprocating speed: 50 times / min [Evaluation criteria] Rank A: Silicone oil film removal area rate is 95% or more Rank B: Silicone oil film removal area rate is 90% or more but less than 95% Rank C: Silicone oil film removal area rate is 85% or more but less than 90% Rank D: Silicone oil film removal area rate is 80% or more but less than 85% Rank E: Silicone oil film removal area rate is less than 50%

[0093] Examples 2 to 10 A wiper blade was produced and evaluated in the same manner as in Example 1, except that the types and amounts of various materials for the prepolymer and the types and amounts of various materials for the curing agent were as shown in Table 3. In Example 3, tris(phenylisocyanate)thiophosphate (trade name: Ultite Super CAII, manufactured by Toho Chemical Industry Co., Ltd.) (hereinafter referred to as TPTI) was used as the tri- or higher functional isocyanate for the prepolymer. In Example 5, polymeric MDI (trade name: Millionate MR-400, manufactured by Tosoh Corporation) (hereinafter referred to as MR400) was used as the tri- or higher functional isocyanate for the prepolymer. In Example 6, glycerin (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the polyfunctional alcohol for the curing agent.

[0094] Examples 11 to 20 A wiper blade was produced and evaluated in the same manner as in Example 1, except that the types and amounts of various materials for the prepolymer and the types and amounts of various materials for the curing agent were as shown in Table 4. In Example 13, trimethylolpropane (manufactured by Tokyo Chemical Industry Co., Ltd.) (hereinafter referred to as TMP) was used as the polyfunctional alcohol for the curing agent. In Example 14, polymeric MDI (trade name: Millionate MR-200, manufactured by Tosoh Corporation) (hereinafter referred to as MR200) ​​was used as the polyfunctional isocyanate for the prepolymer. In Example 18, polybutylene adipate was used as the polyol for the curing agent. A polyester polyol (trade name: Nipporan 4009, manufactured by Tosoh Corporation) (hereinafter referred to as PBA1000) was used. Furthermore, in Example 19, polyhexylene adipate polyester polyol (trade name: Nipporan 136, manufactured by Tosoh Corporation) (hereinafter referred to as PHA2600) having a number average molecular weight of 2600 was used as the polyol for the prepolymer.

[0095] Examples 21 to 28 A wiper blade was produced and evaluated in the same manner as in Example 1, except that the types and amounts of various materials for the prepolymer and the types and amounts of various materials for the curing agent were as shown in Table 5.

[0096] Example 29 304.0 g of 4,4'-MDI, 20.0 g of polymeric MDI (trade name: Cosmonate M-200, manufactured by Mitsui Chemicals, Inc.) (hereinafter referred to as M200), and 676.0 g of polytetramethylene ether glycol (trade name: PTG-2000SN, manufactured by Hodogaya Chemical Co., Ltd.) (hereinafter referred to as PTG2000SN) having a number average molecular weight of 2000 were reacted at 80°C for 3 hours to prepare a prepolymer with an NCO content of 7.9 mass%. A curing agent was prepared by mixing 39.6 g of pentaerythritol, 290.3 g of polytetramethylene ether glycol (trade name: PTG-1000SN, manufactured by Hodogaya Chemical Co., Ltd.) having a number average molecular weight of 1000 (hereinafter referred to as PTG1000SN), 0.13 g of Polycat 46, and 0.55 g of No. 25. The prepolymer prepared above and a curing agent were mixed to obtain a raw material composition. This raw material composition was then poured into a mold for a wiper blade and cured at 130°C for 6 minutes. The mold was then demolded to obtain a polyurethane molded article. The obtained polyurethane molded article was processed in the same manner as in Example 1 to produce wiper blades, which were then evaluated.

[0097] Examples 30 to 32 Wiper blades were produced and evaluated in the same manner as in Example 1, except that the types and amounts of various materials for the prepolymer and the types and amounts of various materials for the curing agent were as shown in Tables 5 and 6.

[0098] Example 33 349.5 g of 4,4'-MDI and 650.5 g of polybutylene adipate polyester polyol (trade name: Nipporan 4010, manufactured by Tosoh Corporation) (hereinafter referred to as PBA2000) having a number average molecular weight of 2000 without adding any trifunctional or higher polyfunctional isocyanate were reacted at 80°C for 3 hours to prepare a prepolymer with an NCO content of 9.0 mass%. A curing agent was prepared by mixing 40.4 g of 1,4-BD, 5.0 g of glycerin, 5.0 g of PHA1000, 0.05 g of Polycat 46, and 0.25 g of No. 25. This curing agent was mixed with the previously prepared prepolymer to obtain a raw material composition. This raw material composition was poured into a mold for forming a wiper blade and cured at 130°C for 10 minutes. The mold was then demolded and secondary cured at 130°C for 60 minutes to obtain a polyurethane molded product. The resulting polyurethane molded product was processed in the same manner as in Example 1 to produce a wiper blade, which was then evaluated.

[0099] Example 34 A wiper blade was produced in the same manner as in Example 1, except that the types and amounts of various materials for the prepolymer and the types and amounts of various materials for the curing agent were as shown in Table 6. Next, an ultraviolet integrated light dose of 492 mJ / cm was applied to the lip portion of this wiper blade. 2 The wiper blade according to this example was obtained by irradiating the wiper blade with ultraviolet light so that the maximum emission wavelength peak was at 254 nm. Slump (manufactured by Toshiba Lightech Corp.) was used. This wiper blade was evaluated in the same manner as in Example 1.

[0100] Examples 35 and 36 Wiper blades were produced in the same manner as in Example 1, except that the types and amounts of various materials for the prepolymer and the types and amounts of various materials for the curing agent were as shown in Table 6. Furthermore, the obtained wiper blades were irradiated with ultraviolet light in the same manner as in Example 34, except that the integrated light amount was changed to the values ​​shown in Table 6, to obtain wiper blades according to Examples 35 and 36. These wiper blades were evaluated in the same manner as in Example 1.

[0101] Example 37 296.6 g of 4,4'-MDI, no tri- or higher functional isocyanate was added, and 703.4 g of PBA2000 was used, and the mixture was reacted at 80°C for 3 hours to obtain a prepolymer with an NCO content of 7.0 mass%. A curing agent was prepared by mixing 52.0 g of 1,4-BD, 19.2 g of glycerin, 0.05 g of Polycat 46 without PHA1000, and 0.25 g of No. 25. This curing agent was mixed with the previously prepared prepolymer to obtain a raw material composition. This raw material composition was poured into a mold for a wiper blade and cured at 130°C for 10 minutes. The mold was then demolded and secondary cured at 130°C for 60 minutes to obtain a polyurethane molded body. The resulting polyurethane molded body was processed in the same manner as in Example 1 to produce a wiper blade. This wiper blade was irradiated with ultraviolet light in the same manner as in Example 34 to obtain the wiper blade of this example. However, the ultraviolet light irradiation was performed at an integrated light dose of 1968 mJ / cm. 2 The obtained wiper blade was evaluated in the same manner as in Example 1.

[0102] Example 38 A wiper blade was produced and evaluated in the same manner as in Example 1, except that the types and amounts of various materials for the prepolymer and the types and amounts of various materials for the curing agent were as shown in Table 6.

[0103] Examples 39 and 40 Wiper blades were produced in the same manner as in Example 1, except that the types and amounts of various materials for the prepolymer and the types and amounts of various materials for the curing agent were as shown in Table 6. Furthermore, the obtained wiper blades were irradiated with ultraviolet light in the same manner as in Example 34, except that the integrated light amount was changed to the values ​​shown in Table 6, to obtain wiper blades according to Examples 39 and 40. These wiper blades were evaluated in the same manner as in Example 1.

[0104] Example 41 The types and amounts of various materials used for the prepolymer are shown in Table 7. These materials were mixed and reacted at a temperature of 80°C for 3 hours to prepare a prepolymer with an NCO content of 9.0 mass%. In addition, various materials for the curing agent as shown in Table 7 were mixed in the amounts shown in Table 7 to prepare a curing agent. The above prepolymer and curing agent were mixed to obtain a raw material composition. This raw material composition was poured into a mold for a wiper blade and cured at a temperature of 130°C for 10 minutes. Thereafter, the mold was removed and secondary curing was carried out at a temperature of 130°C for 60 minutes to obtain a polyurethane molded product. The obtained polyurethane molded product was processed in the same manner as in Example 1 to produce a wiper blade according to this example. The obtained wiper blade was evaluated in the same manner as in Example 1.

[0105] Examples 42 to 44 The types and amounts of various prepolymer materials used were as shown in Table 7. Prepolymers were prepared in the same manner as in Example 41. The NCO content of the prepolymer according to Example 42 was 8.2% by mass, the NCO content of the prepolymer according to Example 43 was 15.0% by mass, and the NCO content of the prepolymer according to Example 44 was 18.0% by mass. In addition, curing agents were prepared in the same manner as in Example 41, except that the various materials for the curing agent and the amounts used were as shown in Table 7. Wiper blades were produced and evaluated in the same manner as in Example 41, except that these prepolymers and curing agents were used.

[0106] Examples 45 and 46 The wiper blade obtained in Example 44 was irradiated with ultraviolet light in the same manner as in Example 34, except that the integrated light amount was set to the value shown in Table 6, to obtain wiper blades according to Examples 45 and 46. The obtained wiper blades were evaluated in the same manner as in Example 1.

[0107] Examples 47 to 50 Prepolymers were prepared in the same manner as in Example 41, except that the types and amounts of various materials for the prepolymers were as shown in Table 7. The NCO content of the prepolymer according to Example 47 was 10.0% by mass, the NCO content of the prepolymer according to Example 48 was 9.6% by mass, the NCO content of the prepolymer according to Example 49 was 9.3% by mass, and the NCO content of the prepolymer according to Example 50 was 9.2% by mass. In addition, curing agents were prepared in the same manner as in Example 41, except that the various materials for the curing agents and the amounts used were as shown in Table 7. Wiper blades according to Examples 47 to 50 were produced and evaluated in the same manner as in Example 41, except that these prepolymers and curing agents were used.

[0108] Example 51 The tip of the lip of a wiper blade manufactured in the same manner as in Example 37 was immersed in 4,4'-MDI dissolved at a temperature of 80°C for 1 minute. The wiper blade was wiped with a sponge to remove the 4,4'-MDI adhering to the surface of the immersed portion. The wiper blade was then aged for 24 hours in an environment at a temperature of 23°C and a relative humidity of 50%, forming a hardened region at the tip of the lip portion. Thus, a wiper blade according to this example was obtained. This wiper blade was evaluated in the same manner as in Example 1.

[0109] Example 52 A wiper blade according to this example was produced in the same manner as in Example 51, except that the 4,4'-MDI adhering to the surface of the immersion-treated wiper blade was wiped off and then the wiper blade was heated at a temperature of 100°C for 30 minutes. This wiper blade was evaluated in the same manner as in Example 1.

[0110] Example 53 A wiper blade according to this example was obtained by surface treatment in the same manner as in Example 51, except that the wiper blade produced in the same manner as in Example 4 was immersed in 4,4'-MDI for 3 minutes. This wiper blade was evaluated in the same manner as in Example 1.

[0111] Example 54 A wiper blade according to this example was produced in the same manner as in Example 53, except that after wiping off the 4,4'-MDI adhering to the surface of the immersion-treated wiper blade, the wiper blade was heated at a temperature of 100°C for 30 minutes. This wiper blade was evaluated in the same manner as in Example 1.

[0112] Comparative Example 1 The types and amounts of various materials used for the prepolymer are shown in Table 9. These materials were mixed and reacted at a temperature of 80°C for 3 hours to prepare a prepolymer with an NCO content of 14.0 mass%. In addition, various materials for the curing agent shown in Table 9 were mixed in the amounts shown in Table 9 to prepare a curing agent. The above prepolymer and curing agent were mixed to obtain a raw material composition. This raw material The composition was poured into a mold for a wiper blade and cured at 130°C for 10 minutes. The composition was then demolded and secondary cured at 130°C for 60 minutes to obtain a polyurethane molded article. The obtained polyurethane molded article was processed in the same manner as in Example 1 to produce a wiper blade according to this example. The obtained wiper blade was evaluated in the same manner as in Example 1.

[0113] Comparative Example 2 A prepolymer having an NCO content of 9.0% by mass was prepared in the same manner as in Comparative Example 1, except that the types and amounts of various materials for the prepolymer were as shown in Table 9. Furthermore, a curing agent was prepared in the same manner as in Comparative Example 1, except that the types and amounts of various materials for the curing agent were as shown in Table 9. A wiper blade according to this comparative example was produced and evaluated in the same manner as in Comparative Example 1, except that this prepolymer and curing agent were used.

[0114] Comparative Example 3 A prepolymer having an NCO content of 7.0% by mass was prepared in the same manner as in Comparative Example 1, except that the types and amounts of various materials for the prepolymer were as shown in Table 9. A curing agent was also prepared in the same manner as in Comparative Example 1, except that the types and amounts of various materials for the curing agent were as shown in Table 9. A wiper blade was produced in the same manner as in Comparative Example 1, except that this prepolymer and curing agent were used. The obtained wiper blade was exposed to an accumulated light dose of 8200 mJ / cm. 2 Except for the above, ultraviolet light was irradiated in the same manner as in Example 34 to obtain a wiper blade according to this comparative example. The obtained wiper blade was evaluated in the same manner as in Example 1.

[0115] Comparative Example 4 For 100 parts by mass of natural rubber, 48.0 parts by mass of carbon black (product name: Toka Black #7360SB, manufactured by Tokai Carbon Co., Ltd.), 5.0 parts by mass of zinc oxide (product name: Zinc oxide type 2, manufactured by Sakai Chemical Industry Co., Ltd.), 1.0 part by mass of zinc stearate (product name: SZ-2000, manufactured by Sakai Chemical Industry Co., Ltd.), and 20 parts by mass of calcium carbonate (product name: Nanox #30, manufactured by Maruo Calcium Co., Ltd.) were added and kneaded for 15 minutes in an internal mixer adjusted to 50°C. To this mixture, 1.2 parts by mass of sulfur and 4.5 parts by mass of tetrabenzyl thiuram sulfide (TBzTD) (product name: Percasit TBzTD, manufactured by Frekins Co., Ltd.) were added as vulcanizing agents. Next, the mixture was kneaded for 10 minutes in a two-roll mill cooled to a temperature of 25°C to obtain a rubber composition. The obtained rubber composition was placed in a mold for forming a wiper blade and heated at a temperature of 170°C for 20 minutes to be vulcanized. The mixture was then demolded to obtain a wiper blade according to this comparative example. The obtained wiper blade was evaluated in the same manner as in Example 1.

[0116] Tables 3 to 9 show the evaluation results of the wiper blades according to the examples and comparative examples. [Table 3]

[0117] [Table 4]

[0118] [Table 5]

[0119] [Table 6]

[0120] [Table 7]

[0121] [Table 8]

[0122] [Table 9] [Explanation of symbols]

[0123] 1: blade support portion, 2: neck, 3: lip portion, 4: tapered portion, 5: first tapered surface, 6: second tapered surface, 7: tip surface, 8: first edge, 9: second edge, 10: member to be cleaned, 11: first line segment, 12: observation area

Claims

1. 1. A vehicle wiper blade for a vehicle windshield wiper device, comprising: a blade support; a lip portion pivotally connected to the blade support portion via a neck, The lip portion has a tapered portion in which a cross section in a direction perpendicular to the longitudinal direction of the wiper blade gradually decreases in width from a side closer to the blade support portion toward a direction away from the blade support portion, The lip portion is a first tapered surface and a second tapered surface that constitute the tapered portion; a tip end surface that, together with the first tapered surface and the second tapered surface, constitutes a first edge and a second edge on a side of the lip portion farthest from the blade support portion, Assuming that a first line segment is drawn on the first tapered surface parallel to the first edge and at a distance of 10 μm from the first edge, The length of the first line segment is L1, The points (1 / 8)L1, (1 / 2)L1, and (7 / 8)L1 from one end side on the first line segment are designated as P0, P1, and P2, respectively; the elastic modulus of the first tapered surface is measured at 70,000 points at a pitch of 0.1 μm using a scanning probe microscope for each of three rectangular observation regions on the first tapered surface, the observation regions having centers of gravity at points P0, P1, and P2, one side of which is 70 μm long and parallel to the first line segment, and one side of which is 10 μm long and perpendicular to the first line segment; the average value of the elastic modulus values ​​obtained for a total of 210,000 points is 15 MPa to 470 MPa, and the coefficient of variation of the elastic modulus is 17.6% or less; Assuming that a second line segment is drawn on the second tapered surface parallel to the second edge and at a distance of 10 μm from the second edge, The length of the second line segment is L2, The points (1 / 8)L2, (1 / 2)L2, and (7 / 8)L2 from one end side on the second line segment are designated as P3, P4, and P5, respectively; The second tapered surface has three rectangular observation areas, each of which has a center of gravity at each of the points P3, P4, and P5, one side of which is 70 μm long and parallel to the second line segment, and one side of which is 10 μm long and perpendicular to the second line segment, and the three rectangular observation areas are spaced 70 μm apart at a 0.1 μm pitch. the average value of the elastic modulus of a total of 210,000 points obtained when measuring the elastic modulus of the second tapered surface at 0,000 points using a scanning probe microscope is 15 MPa to 470 MPa, and the coefficient of variation of the elastic modulus is 17.6% or less; the tapered portion contains polyurethane; The polyurethane contains a reaction product of a raw material composition containing an isocyanate compound including a diisocyanate and a trifunctional or higher polyfunctional isocyanate, Assuming that a line segment is drawn on the first tapered surface and the second tapered surface of the tapered portion, parallel to the first edge and the second edge, respectively, and the distance between the first edge and the second edge is 0.5 mm, the length of the line segment is L', and points 1 / 8L', 1 / 2L', and 7 / 8L' from one end side on the line segment are P0', P1', and P2', respectively; a sample sampled at each of the P0', P1', and P2' points on the first tapered surface and the second tapered surface is heated and vaporized in an ionization chamber, and the sample molecules are ionized using a direct sample introduction mass spectrometer, the sample being heated to 1000°C at a heating rate of 10°C / s; The detected amount of all ions is M1, the integrated intensity of the peak in the extracted ion thermogram corresponding to the m / z value range derived from the tri- or higher functional isocyanate is defined as M2; When the integrated intensity of the peak in the extracted ion thermogram corresponding to the range of m / z values ​​derived from the diisocyanate is defined as M3, In the first tapered surface, M2 / M1 is 0.0010 to 0.0150, and M3 / M1 is 0.0200 to 0.1100, A wiper blade for a vehicle, wherein, on the second tapered surface, M2 / M1 is 0.0010 to 0.0150, and M3 / M1 is 0.0200 to 0.1100.

2. The vehicle wiper blade according to claim 1, wherein the raw material composition contains an alcohol including a trifunctional or higher polyfunctional alcohol and a diol.

3. The raw material composition contains an alcohol including a trifunctional or higher polyfunctional alcohol, When samples sampled at P0′, P1′, and P2′ of the first tapered surface and the second tapered surface are measured by pyrolysis GC / MS, a concentration of a tri- or higher functional alcohol in polyurethane in the first tapered surface is 0.04 mmol / g to 0.39 mmol / g; 3. The vehicle wiper blade according to claim 1, wherein the concentration of the tri- or higher functional alcohol in the polyurethane on the second tapered surface is 0.04 mmol / g to 0.39 mmol / g.

4. 4. The vehicle wiper blade according to claim 2, wherein the tri- or higher functional alcohol includes at least one selected from the group consisting of trimethylolpropane and glycerin.

5. The wiper blade for a vehicle according to any one of claims 1 to 4, wherein the trifunctional or higher polyfunctional isocyanate is at least one selected from the group consisting of triphenylmethane-4,4',4''-triisocyanate (TTI), tris(phenylisocyanate)thiophosphate (TPTI), and polymeric MDI.

6. In measuring the elastic modulus of the first tapered surface, The average value of the elastic modulus is 32 MPa or more and 62 MPa or less, In measuring the elastic modulus of the second tapered surface, 6. The method according to claim 1, wherein the average value of the elastic modulus is 32 MPa or more and 62 MPa or less. The wiper blade for a vehicle according to any one of claims 1 to 4.

7. In measuring the elastic modulus of the first tapered surface, The coefficient of variation of the elastic modulus is 6.0% or less, In measuring the elastic modulus of the second tapered surface, 7. The wiper blade for a vehicle according to claim 1, wherein the coefficient of variation of the elastic modulus is 6.0% or less.

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