JPH09136959A - Wiper blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiper blade prevented from juddering during wiping. SOLUTION: This wiper blade 2 has an acetylene-terminated polyisoimide cover layer of 1 to 50μm. The cover layer may occasionally contain at most 50wt.%, based on the polyisoimide, of at least one kind of fine particles selected from among fine molybdenum disulfide particles, fine graphite particles, fine Teflon (R) particles, fine silicone rubber particles, and fine polyethylene particles to secure an effect of remarkably reducing juddering during wiping with the wiper for a long period of service.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a wiper blade which has excellent judder resistance and wear resistance and has a long life.

[0002]

2. Description of the Related Art As a conventional aliphatic nylon solution and a wiper blade coated with the same, for example, Japanese Patent Laid-Open No.
No. 309534 discloses a method of dissolving methoxymethylated nylon in an organic solvent and coating the solution on a wiper blade. Further, JP-A-5-77690 proposes a method in which a formic acid solution of low molecular weight aliphatic nylon is sprayed on a wiper blade.

[0003]

However, in such conventional aliphatic nylon solutions and wiper blades coated therewith, methoxymethylated nylon and low molecular weight aliphatic nylons have low mechanical properties and low Regarding the molecular weight aliphatic nylon, the low molecular weight aliphatic nylon was somewhat decomposed by the formic acid used as the solvent, and the molecular weight was further reduced, so that the wiper blade could not be provided with good wiping durability. Therefore, the conventional wiper blade coated with the aliphatic nylon solution has a problem that the coating layer is worn or missing during wiping durability and the coefficient of friction increases, causing judder during wiping.

[0004]

Means for Solving the Problems The present invention has been made in view of such conventional problems, and is characterized by having an acetylene-terminated polyisoimide (hereinafter abbreviated as polyisoimide) coating layer of 1 to 50 μm. A wiper blade, and in some cases, the coating layer contains one or more kinds selected from molybdenum disulfide fine particles, graphite fine particles, Teflon fine particles, silicon rubber fine particles, and polyethylene fine particles in an amount of up to 50% by weight based on polyisoimide. The purpose is to solve the above problems.

[0005]

EXAMPLES The present invention will be described below based on examples. Table 1 is a table showing examples of the present invention.

[Table 1]

Explaining the constitution of this table, for each example, the composition of the polyisoimide solution, the weight% of each component, the film thickness formed on the wiper blade, the visual observation of the film state, the evaluation of the judder property, and the rubber material Has been shown.

Next, the chemicals used in these examples will be described. Thermido (NSC manufactured by Kanebo Co., Ltd.) is used as the polyisoimide, and N-methyl-2-pyrrolidone, tetrahydrofuran, monoglyme, dioxane, diglyme, and methanol (special grade manufactured by Wako Pure Chemical Industries, Ltd.) are used as the modified nylon. Was methoxymethylated nylon (manufactured by Dainippon Ink and Chemicals, Inc.). Further, regarding fine particles, molybdenum disulfide fine particles (manufactured by Hitachi Powder Metallurgy Co., Ltd., average particle diameter 2 μm), graphite (manufactured by Hitachi Powder Metallurgy Co., Ltd., average particle diameter 2 μm), silicon rubber fine particles (Toshiba Silicon Co., Ltd.) Made, average particle size 4μ
m), polyethylene fine particles (made by Steel Chemical Co., Ltd., average particle size 4 μm), Teflon fine particles (made by Daikin Industries, Ltd.,
An average particle size of 4 μm) was used. As the rubber material for the wiper blade, natural rubber or a blend rubber of natural rubber and chloroprene rubber was used.

Hereinafter, examples of the present invention will be described.
Examples 1 to 6 show solvents that can be used to prepare the polyisoimide solution. Polyisoimide is soluble in ethers, aprotic solvents, and the like, and even if any solvent is used, a uniform and highly durable polyisoimide coating can be formed on the wiper blade, so that the judder property is evaluated better than in Comparative Example 1.

In Examples 7 to 9, the film thickness of the polyisoimide coating was shown. In Examples 7, 8 and 9, the polyisoimide film thicknesses of 2, 20 and 40 μm were evaluated, respectively, but all have excellent judder characteristics. However, when the film thickness was 0.5 μm as in Comparative Example 2, a uniform film was not formed on the wiper blade, and when the film thickness was 60 μm as in Comparative Example 3, cracks and wrinkles were generated in the wiper blade film. Therefore, the film thickness of the polyisoimide coating is preferably 1 μm to 50 μm.

Examples 10 to 11 show cases where molybdenum disulfide fine particles were added as an additive to the polyisoimide coating. The particle size of the fine particles is usually 1 to 4 μm, but the particle size is appropriately set according to the film thickness. As shown in Comparative Example 4, when the addition ratio of the molybdenum disulfide fine particles was 60% by weight or more based on the polyisoimide, the wiper blade coating film formed was cracked and wrinkled. Therefore, it is preferable that the addition amount of the molybdenum disulfide fine particles is 50% at the maximum with respect to the polyisoimide.

The case where graphite, silicon rubber fine particles, polyethylene fine particles, and Teflon fine particles are added as additives to Examples 12 to 15 is shown. In this case, an addition amount of less than 50% was used with respect to the maximum addition amount of polyisoimide of the above-mentioned molybdenum disulfide fine particles. Further, here, the case where the heat treatment is applied to the wiper blade having the polyisoimide film formed thereon is shown in Example 16. Here, the heating causes the polyisoimide to undergo a crosslinking reaction to form a stronger coating. The heating temperature condition is preferably 200 ° C. or higher, and the heating time is appropriately set according to the film thickness. Also in Example 17, as in Example 16, a film having excellent judder characteristics is formed.

Next, the judder property evaluation will be described. FIG. 1 is a schematic diagram relating to wind-glass and wiper wiping durability. 1 is a laminated glass for automobiles, 2 is a wiper blade coated with polyisoimide, and 3 is a wiper arm. Using this device, the judder property during wiping durability was evaluated. When the judder could be visually confirmed, it was recorded in the judder property evaluation column of Table 1 as the chatter vibration direction.

Next, the procedure of the examples and comparative examples shown in Table 1 will be described. <Example 1> 5 g of polyisoimide and 95 g of the solvent of each example were placed in an Erlenmeyer flask and sufficiently mixed with stirring to obtain a transparent homogeneous solution. This solution was injected into a spray gun, uniformly sprayed on a wiper blade, and dried at room temperature for 2 hours to obtain a wiper blade 2 having a polyisoimide coating.
Next, the state of the coating film on the wiper blade 2 is visually evaluated, and if there is no crack or wrinkle, this is attached to the wiper arm 3 and the wiper blade 2 is placed on the windshield 1.
And the judderability was evaluated.

<Examples 7 to 9> Predetermined amounts of polyisoimide and N-methyl-2-pyrrolidone were placed in an Erlenmeyer flask and thoroughly mixed with stirring to form a transparent homogeneous solution, which was sprayed and dried with this solution. By repeating the above, a wiper blade 2 having a predetermined film thickness was obtained. The subsequent operations are the same as in Example 1.

<Examples 10 to 11> After the solution was prepared by using a predetermined amount of molybdenum disulfide fine particles, polyisoimide and N-methyl-2-pyrrolidone, the same operation as in Example 1 was performed.

<Examples 12 to 15> The same as Example 10 except that the molybdenum disulfide fine particles of Example 10 were replaced by the fine particles of each Example.

<Examples 16 and 17> Examples 1 and 10
The wiper blade 2 produced in 1 above was further heat-treated at 200 ° C. for 5 minutes to form a polyisoimide cured film. After that, the same operation as in Example 1 was performed.

<Comparative Example 1> The same operation as in Example 1 was performed using a predetermined methoxymethylated nylon solution.

<Comparative Examples 2 and 3> Predetermined amounts of polyisoimide and N-methyl-2-pyrrolidone were placed in an Erlenmeyer flask and thoroughly mixed with stirring to form a transparent homogeneous solution, which was sprayed and dried with this solution. Was repeated to obtain a wiper blade having a predetermined film thickness.

<Comparative Example 4> After preparing a solution containing a predetermined amount of molybdenum disulfide fine particles, polyisoimide and N-methyl-2-pyrrolidone, the same operation as in Example 1 was performed to form a film.

[0021]

As described above, according to the present invention, the constitution is a wiper blade having an acetylene-terminated polyisoimide coating layer 1 to 50 μm, and in some cases, the coating layer has a maximum of 50 relative to polyisoimide. By adding up to 1% by weight or more selected from molybdenum disulfide fine particles, graphite fine particles, Teflon fine particles, silicon rubber fine particles, and polyethylene fine particles, the effect of significantly reducing the judder at the time of wiper wiping can be obtained.

In addition to the common effects described above, each of the embodiments has the following effects. Since a film of polyisoimide, which is a cross-linkable heat-resistant polymer, is formed on the surface of the wiper blade, solvent resistance and abrasion resistance are greatly improved, and the life of the wiper blade can be extended.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of judder property evaluation of a wiper blade of an example.

[Explanation of symbols]

 1 Wind glass 2 Wiper blade 3 Wiper arm

Claims (2)

[Claims] 1. A wiper blade having an acetylene-terminated polyisoimide coating layer of 1 to 50 μm. 2. A molybdenum disulfide microparticle, a graphite microparticle, a Teflon microparticle, a silicon rubber microparticle, and a polyethylene microparticle, at least 50% by weight of the acetylene-terminated polyisoimide is contained in one or more kinds. The described wiper blade.