Covering material and weather stripping

Abstract

To provide a technique that contributes to processability of a coated body material, slidability of a coated body, wear resistance and the like.SOLUTION: Extrusion molding is used to form a coated body 3 on a surface of an elastic contact part 2 of a substrate 10 that is in pressure contact with an object to be slid. A material of the coated body shall be at least a rubber material or a thermoplastic resin material and a plurality of kinds of oily substances. At least two of the plurality of kinds of oily substances shall have different viscosities and shall be encapsulated in microcapsules or mixed in microcapsules, respectively. In the one with low viscosity among the plurality of kinds of oily substances, a bleeding speed at which the oily substances bleed onto a coated body surface is relatively fast. On the other hand, when the viscosity of the oily substances is high, the bleeding speed is relatively slow. In addition, by encapsulating a volatile expander in the microcapsules that encapsulate the oily substance, an irregular rough surface is formed on the coated body surface after molding.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a covering body and a weather strip, and more particularly to a technique applicable to a molded body that requires slidability, such as a weather strip for an automobile. [Background technology]

[0002] For example, in the case of molded articles that require sliding properties, such as automobile weather strips, multilayer structures are known in which a sliding coating is formed on the surface of a substrate that constitutes the molded article (e.g., in a portion that requires sliding properties).

[0003] As a specific example, in a molded body having a base including a support part for mounting to a vehicle body (in the case of a glass run, a window frame such as a door panel) and an elastic contact part (lip part, etc.) that is provided on the support part and elastically presses against a sliding object such as a glass member (window glass, etc.), a coating is formed on the surface of the elastic contact part of the base (the side against which the sliding object is located).

[0004] For example, Patent Document 1 discloses that a coating material containing a polyolefin resin, an oily substance (organopolysiloxane in Patent Document 1), fatty acid amide, silica, etc. is used in a coating provided on the elastic contact surface of a base (a base made of an olefin-based thermoplastic elastomer in Patent Document 1).

[0005] Patent Document 2 discloses a configuration in which a base material and a covering material are extruded to form a covering on the surface of an elastic contact portion of a base. The covering material disclosed in Patent Document 2 is a blend of a rubber material or a thermoplastic resin material and microcapsules containing an oily substance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-176408 [Patent Document 2] Patent No. 3184299 Summary of the Invention [Problem to be solved by the invention]

[0007] In the case of Patent Document 1, the sliding property of the coating can be improved by increasing the amount of oily substance blended in the coating material. However, if the amount of oily substance blended is too large, the processability of the coating material may be reduced. On the other hand, by suppressing the amount of oily substance blended, it is possible to obtain the desired processability of the coating material, but the sliding property of the coating may be reduced, and the wear resistance may also be reduced accordingly.

[0008] In the case of Patent Document 2, microcapsules containing an oily substance are used in the coating material, so it is considered that the desired processability (processability related to extrusion molding) is easier to obtain compared to Patent Document 1. However, since the microcapsules of Patent Document 2 simply contain one type of oily substance, if the viscosity of the oily substance is low, the coating may easily achieve initial sliding properties, but it may be difficult to maintain the sliding properties for a long time, and the wear durability may be reduced. On the other hand, if the viscosity of the oily substance in the microcapsules is high, the sliding properties of the coating may be easily maintained for a long time, and the desired wear durability may be obtained, but the initial sliding properties may be reduced.

[0009] The present invention has been made in view of the above-mentioned problems, and aims to provide a technique that contributes to the workability of the coating material and the sliding properties and wear resistance of the coating. [Means for solving the problem]

[0010] The coating and weatherstrip of this invention are technical ideas created to solve the above-mentioned problems, and specifically, one embodiment of the coating of this invention is a coating formed on the surface of a base body by extrusion molding, characterized in that the material of the coating is a blend of at least a rubber material or a thermoplastic resin material and multiple types of oily substances, and at least two of the multiple types of oily substances have different viscosities and are each encapsulated in a microcapsule.

[0011] Another aspect of the coating is a coating formed on the surface of a base by extrusion molding, characterized in that the material of the coating is a blend of at least a rubber material or a thermoplastic resin material and multiple types of oily substances, and at least two of the multiple types of oily substances have different viscosities and are encapsulated in a microcapsule in a mixed state.

[0012] Each oily substance encapsulated in the microcapsule may have a viscosity in the range of 200,000 to 1,000,000 cSt. A part of each oily substance encapsulated in the microcapsule may have a viscosity in the range of 20 to less than 1,000 cSt, and the other part of each oily substance may have a viscosity in the range of 1,000 to 1,000,000 cSt. The material of the covering body may have a blending amount of the microcapsules in the range of 0.5 to 50 parts by weight when the blending amount of the rubber material or the thermoplastic resin material is 100 parts by weight. The material of the covering body may have a blending amount of the microcapsules in the range of 10 to 80 parts by weight when the blending amount of the microcapsules blended in the rubber material or the thermoplastic resin material is 100 parts by weight. The microcapsules may have an average particle size of 70 μm or less.

[0013] The material of the covering body may be characterized in that a volatile expansion agent is encapsulated in the microcapsules (microcapsules encapsulating an oily substance). The weight ratio of the volatile expansion agent to the oily substance may be within a range of 1:9 to 9:1, and the volatile expansion agent may be blended in a range of 10 to 80 parts by weight with respect to 100 parts by weight of the microcapsules. The material of the covering body may be characterized in that the blending amount of the microcapsules is within a range of 0.5 to 10 parts by weight when the blending amount of the rubber material or thermoplastic resin material is 100 parts by weight. The microcapsules may have an average particle size of 70 μm or less, and the covering body may be characterized in that thermal expansion cells having an average cell size of 200 μm or less are formed by the expansion of the microcapsules by the extrusion molding. The volatile expansion agent may be a hydrocarbon having a carbon number of 8 to 15.

[0014] The coating material may further include a solid lubricant. The coating material may include a solid lubricant in an amount ranging from 0.1 to 5 parts by weight, based on 100 parts by weight of the rubber material or thermoplastic resin material. The solid lubricant may be a fatty acid amide.

[0015] The oily substance encapsulated in the microcapsules may be organopolysiloxane.

[0016] One aspect of the weatherstrip is a weatherstrip in which the covering body is formed on the surface of a base body by extrusion molding, and the covering body is pressed against a sliding object, and the sliding object is any one of a glass member (including resin glass), a door panel, and a body panel. Effect of the Invention

[0017] As described above, the present invention can contribute to the workability of the coating material, the sliding properties of the coating, and the wear resistance, etc. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is a schematic explanatory diagram showing an example of a weather strip provided with a covering body according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The coating of this embodiment and the weatherstrip on which the coating is formed are completely different from coatings made by extrusion molding, such as those in Patent Document 2, which simply use a coating material that encapsulates one type of oily substance in microcapsules.

[0020] That is, in this embodiment, the coating material to be extruded contains a plurality of oily substances, at least two of which have different viscosities, and the at least two oily substances are each encapsulated in a microcapsule, or encapsulated in a mixed state in a microcapsule.

[0021] According to this embodiment, at least two of the multiple types of oily substances contained in the coating material are encapsulated in microcapsules, making it easier to obtain the desired processability (processability for extrusion molding) of the coating material.

[0022] In addition, it is possible to make full use of the characteristics of the oily substances (at least two oily substances with different viscosities) contained in the microcapsules. That is, among the oily substances contained in the microcapsules, those with low viscosity (hereinafter simply referred to as low-viscosity oily substances) have a relatively fast bleeding speed at which the oily substance seeps out onto the surface of the coated body, making it easier to obtain the initial sliding properties of the coated body, for example. On the other hand, among the oily substances, those with high viscosity (hereinafter simply referred to as high-viscosity oily substances) have a relatively slow bleeding speed, making it easier to maintain the sliding properties of the coated body for a long time and obtain the desired wear resistance.

[0023] Therefore, according to this embodiment, compared to, for example, Patent Documents 1 and 2, it is possible to contribute to the workability of the coating material, the sliding properties of the coating, the wear resistance, and the like.

[0024] As described above, the covering body and weather strip of this embodiment may be such that at least two of the multiple types of oily substances blended in the covering body material have different viscosities and are encapsulated in microcapsules (or are encapsulated in a microcapsule in a mixed state). That is, it is possible to appropriately apply technical common sense in various fields (for example, the field of automobile parts, the field of extrusion molding, the field of rubber materials, the field of thermoplastic resins, the field of microcapsules, etc.) and appropriately refer to prior art documents, etc. as necessary to modify the design, and the following examples are given as examples.

[0025] Example <Example of the structure of a molded body provided with a covering by extrusion molding> A weatherstrip A in FIG. 1 shows an example of a molded body having a covering body 3 according to this embodiment, and shows a configuration example applicable to weatherstrips for automobiles.

[0026] This weatherstrip A is configured as a base 10 comprising a long support part 1 with a U-shaped cross section formed so that it can be assembled into a window frame (for example, within a groove whose inner wall surface is U-shaped in cross section) in a vehicle body panel not shown, and a plurality of lip-shaped elastic contact parts 2 (in Figure 1, two protruding in opposite directions from the opening end of support part 1) protruding from the inner wall surface of support part 1 so as to maintain the desired glass sealing properties (watertightness, airtightness, etc.) between the window frame and a window glass not shown (for example, window glass that can be moved in the direction of arrow Y in the figure and freely inserted and removed from the inner wall surface side of support part 1).

[0027] Reference numerals 1a and 1b denote locking claws protruding from the outer wall of the support part 1, and serve to prevent the base 10 assembled to the window frame from slipping out of the window frame. A cover 3 is formed on at least the contact surface side with the window glass of the elastic contact part 2, and on the inner wall surface side of the bottom wall 1c of the support part 1 (a portion requiring slidability).

[0028] Such weatherstrip A can be formed by appropriately using an extrusion molding machine to extrude the base material to be applied to the base 10 and the covering material to be applied to the covering 3. Furthermore, according to the multi-layer structure in which the covering 3 is formed on the base 10, the elastic contact part 2 (covering 3) elastically contacts the window glass and can slide freely, making it possible to maintain the desired glass sealing performance.

[0029] The types and amounts of the various components blended in the base material and coating material can be appropriately set according to the manner in which the weatherstrip A is used, and can be set, for example, as shown below.

[0030] <Base material> The substrate material may be any material that can be used to form the substrate 10 by extrusion molding, and an example of such a material is one that is primarily made of a rubber material or a thermoplastic resin material.

[0031] Specific examples of rubber materials include natural rubber (e.g., NR), diene rubber (e.g., SBR, NBR), non-diene rubber (e.g., EP, EPM, EPDM), blended rubber (e.g., EP / SBR, NBR / PVC), etc. These rubber materials may be used alone or in combination of two or more types.

[0032] Specific examples of thermoplastic resin materials include polyamide-based elastomers, polyester-based elastomers, thermoplastic urethane-based elastomers, olefin-based elastomers, styrene-based elastomers, and olefin / styrene-based elastomers. These thermoplastic resin materials may be used alone or in combination of two or more types.

[0033] <Coating material> The covering material is a blend of at least a rubber material or a thermoplastic resin material and multiple types of oily substances (described in detail below), with at least two of the multiple types of oily substances having different viscosities and encapsulated in microcapsules (described in detail below) or encapsulated in a microcapsule in a mixed state. By extruding such a covering material together with a base material, a covering 3 can be formed on the surface of the base 10 (in FIG. 1, the contact surface side of the elastic contact part 2 with the window glass and the inner wall surface side of the bottom wall 1c of the support part 1).

[0034] The rubber material or thermoplastic resin material to be blended in the covering material is not particularly limited, and for example, the same materials as those used in the base material may be used.

[0035] <Multiple types of oily substances> As for the multiple types of oily substances, they may be blended in the coating material (at least two of them may be encapsulated in microcapsules (either encapsulated individually or encapsulated in a mixed state) as described below) and may impart sliding properties to the coating 3 obtained by extrusion molding of the coating material, and various embodiments may be applied. Specific examples of the oily substance include organopolysiloxane, alkyl alkylate, ester oil, wax, etc.

[0036] Further specific examples of organosiloxanes include dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, and the like, as well as modified polysiloxanes such as epoxy-modified, alkyl-modified, amino-modified, carboxyl-modified, alcohol-modified, fluorine-modified, alkylaralkylpolyether-modified, epoxypolyether-modified, and polyether-modified polysiloxanes, which may be used alone or in combination of two or more kinds.

[0037] In addition, as long as at least two of the multiple types of oily substances can be encapsulated in microcapsules described below, substances of various viscosities can be applied, and as an example, substances with a viscosity in the range of 200,000 to 1,000,000 cSt each can be applied (low viscosity oily substance, high viscosity oily substance).As a specific example, a low viscosity oily substance with a viscosity in the range of 20 to less than 1,000 cSt can be applied to a portion of each oily substance encapsulated in a microcapsule, and a high viscosity oily substance with a viscosity in the range of 1,000 to 1,000,000 cSt can be applied to the other portion of each oily substance.

[0038] The low-viscosity oily substance as described above makes it easier to obtain, for example, the initial sliding properties of the coating 3. In addition, the high-viscosity oily substance as described above makes it easier to maintain the sliding properties of the coating 3 for a long time and obtain the desired wear resistance.

[0039] <Microcapsules> The method of encapsulating an oily substance in a microcapsule can be applied in various modes, one example of which is the application of an in-situ polymerization method in which a target oily substance is mixed with a monomer (a monomer that can be polymerized to form the shell wall of the microcapsule; for example, an acrylic monomer, vinylidene chloride, etc.), a dispersant, a catalyst, etc. to obtain a mixed solution, and the mixed solution is polymerized in a desired aqueous solution. Other examples include the application of an interfacial polycondensation method known for nylon, etc., and a coacervate method in which an oily substance is emulsified and mixed in a gelatin solution, and then gum arabic is added to form a film.

[0040] Furthermore, the microcapsules may simply encapsulate one type of oily substance, or may encapsulate a mixture of multiple types of oily substances.

[0041] The shape of the microcapsules can be appropriately set, but for example, they can be set so that the average particle size is about 70 μm or less (preferably within the range of 1 to 50 μm) when mixed with the coating material.

[0042] In the weatherstrip A obtained by applying a coating material containing such microcapsules, for example, as the coating 3 slides repeatedly against a window glass, the shell walls of the microcapsules are successively destroyed, causing the oily substance in the microcapsules to seep out onto the surface of the coating 3.

[0043] The amount of microcapsules in the coating material can also be set appropriately. For example, if the amount of thermoplastic resin material or rubber material in the coating material is 100 parts by weight, the amount of the microcapsules is 0.5 to 50 parts by weight, and the amount of each oily substance encapsulated in the microcapsules is 0.05 to 40 parts by weight (if the amount of the microcapsules is 100 parts by weight, the amount of each oily substance encapsulated in the microcapsules is 10 to 80 parts by weight).

[0044] <Thermal expansion of microcapsules> In the microcapsules, various materials may be mixed and encapsulated together with the oily substance as described above. One example of such a mixture is the inclusion of a volatile swelling agent such as a hydrocarbon.

[0045] When the coating material containing the microcapsules encapsulating the oily substance and the volatile expansion agent is extruded, the volatile expansion agent volatilizes (generates gas) due to the heat of extrusion, and the microcapsules thermally expand. As a result, thermal expansion cells (air bubbles) having a shape corresponding to the degree of thermal expansion of the microcapsules are formed in the coating 3. The surface of the coating 3 is then formed with an uneven rough surface resulting from the thermal expansion cells.

[0046] The rough surface formed on the surface of the coating 3 as described above reduces the contact area between the coating 3 and the window glass, reducing the frictional resistance between them and making it easier to obtain good sliding properties. Also, the shell walls of the thermally expanded microcapsules become thinner and more easily broken, making it easier to obtain the initial sliding properties of the coating 3, for example.

[0047] The volatile expansion agent may be any agent that can be encapsulated in microcapsules together with the oily substance as described above and that can form thermal expansion cells in the coating 3 by extrusion molding. A specific example of such an agent is a hydrocarbon having a carbon number of about 8 to 15.

[0048] The amount of the volatile swelling agent, the shape of the microcapsules when the volatile swelling agent is added, and the amount of the volatile swelling agent can be appropriately set. For example, the weight ratio of the volatile swelling agent to the oily substance is set to within a range of 1:9 to 9:1, and the amount of the volatile swelling agent is set to within a range of 10 to 80 parts by weight per 100 parts by weight of the microcapsules. In addition, the shape of the microcapsules is set to an average particle size of about 70 μm or less (preferably within a range of 1 to 50 μm), and the amount of the microcapsules is set to within a range of 0.5 to 10 parts by weight.

[0049] The size of the thermal expansion cells can be appropriately set by, for example, the type and amount of the volatile expansion agent, and for example, the average cell diameter can be set within the range of 200 μm or less.

[0050] <Solid lubricants> The coating material may contain a solid lubricant, for example, fatty acid amide.

[0051] Specific examples of fatty acid amides include monoamides of higher fatty acids such as stearamide, oxystearoamide, oleylamide, erucylamide, laurylamide, palmitylamide, and behenamide; amides of higher fatty acids such as methylolamide, methylene bis-stearamide, ethylene bis-stearoamide, ethylene bis-oleylamide, and ethylene bis-laurylamide; composite amides such as stearyl oleylamide, N-stearyl erucamide, and N-oleyl palmitamide; and special fatty acid amides commercially available under the trade names Plastrodin and Plastrodin S (Fujisawa Pharmaceuticals). These may be used alone or in combination of two or more types.

[0052] The amount of solid lubricant can also be set appropriately. For example, when the amount of thermoplastic resin material or rubber material in the coating material is 100 parts by weight, the amount of the solid lubricant can be set within the range of 0.1 to 5 parts by weight (preferably 0.5 to 5 parts by weight).

[0053] If the amount of solid lubricant is small (e.g., less than 0.1 parts by weight), the effects (sliding properties, wear resistance) of the solid lubricant may not be fully obtained. Also, if the amount of solid lubricant is large (e.g., more than 5 parts by weight), slippage may easily occur, for example, during the step of compounding the coating material (e.g., the step of mixing with other compounds) or during the extrusion molding step, and sufficient processability may not be obtained.

[0054] According to the weatherstrip A obtained by applying the coating material containing a solid lubricant as described above, the solid lubricant can seep out onto the surface of the coating 3 even before the oily substance in the microcapsules seeps out from the coating 3 (for example, before the shell wall of the microcapsule is destroyed), making it easier to obtain initial sliding properties of the coating 3.

[0055] <Other> In addition to the various components mentioned above, the coating material and base material may contain carbon black, processing aids, liquid polymers (liquid rubber), antioxidants, anti-aging agents, dehydrating agents, heat stabilizers, light stabilizers, UV absorbers, sliding powders (e.g. PMMA, fluororesin (Teflon (registered trademark), etc.) powders, acrylic powders, silicone rubber powders, silicone resin powders, polycarbonate powders, ultra-high molecular weight polyethylene powders, etc.), anti-fog agents, anti-blocking agents, slip agents, dispersants, and flame retardants. Examples of such additives include antistatic agents, conductive agents, tackifiers, crosslinking aids, colorants (titanium oxide, etc.), metal powders (ferrite, etc.), glass fibers, carbon fibers, organic fibers (aramid fibers, etc.), composite fibers, glass balloons, glass flakes, graphite, carbon nanotubes, fullerenes, black powder, various types of rubber, organic foaming agents, thermal expansion capsules, wax, recycled rubber, etc., and any one or more types may be combined and appropriately blended to the extent that the desired properties of the coating 3 or base 10 are not significantly impaired.

[0056] Although the present invention has been described in detail above only with respect to the specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope of the technical concept of the present invention, and it is natural that such modifications and variations fall within the scope of the claims.

[0057] For example, in the examples, a weather strip attached to a window frame of a vehicle body panel is given, and a window glass is given as a sliding object, but the weather strip and the sliding object are not particularly limited, and various embodiments can be applied. Specific examples of sliding objects include glass members (including resin glass), door panels, body panels, etc., and in these cases, it is also possible to achieve the same effects as those shown in the examples. [Explanation of symbols]

[0058] A…Weather strip 1...Support part 1a, 1b...Latching claw part 1c…Bottom wall 10…Matrix 2…Elastic joint 3…Covered body

Claims

1. A coating formed on a surface of a substrate by extrusion molding, The material of the coating is At least a rubber material or a thermoplastic resin material and a plurality of types of oily substances are blended, At least two of the plurality of types of oily substances have different viscosities and are encapsulated in microcapsules, Each oily substance encapsulated in the microcapsules has a viscosity in the range of 200,000 to 1,000,000 cSt; A part of the oily substances encapsulated in the microcapsules has a viscosity in the range of 20 to less than 1000 cSt, and the other part of the oily substances has a viscosity in the range of 1000 to 1,000,000 cSt. A coating body characterized by:

2. A coating formed on a surface of a substrate by extrusion molding, The material of the coating is At least a rubber material or a thermoplastic resin material and a plurality of types of oily substances are blended, At least two of the plurality of types of oily substances have different viscosities and are encapsulated in a microcapsule in a mixed state; Each oily substance encapsulated in the microcapsules has a viscosity in the range of 200,000 to 1,000,000 cSt; A part of the oily substances encapsulated in the microcapsules has a viscosity in the range of 20 to less than 1000 cSt, and the other part of the oily substances has a viscosity in the range of 1000 to 1,000,000 cSt. A coating body characterized by:

3. The coating body according to claim 1 or 2, characterized in that the material of the coating body has a compounding amount of the microcapsules in the range of 0.5 to 50 parts by weight when the compounding amount of the rubber material or thermoplastic resin material is 100 parts by weight.

4. The coating according to claim 1 or 2, characterized in that, when the amount of the microcapsules mixed into the rubber material or thermoplastic resin material is 100 parts by weight, the amount of each oily substance encapsulated in the microcapsules is within the range of 10 to 80 parts by weight.

5. 5. The coated body according to claim 1, wherein the microcapsules have an average particle size of 70 μm or less.

6. 3. The coated body according to claim 1, wherein the material of the coated body is such that a volatile expanding agent is encapsulated in the microcapsules.

7. The coating material according to claim 6, characterized in that the weight ratio of the volatile expansion agent to the oily substance is within the range of 1:9 to 9:1, and the volatile expansion agent is blended in the range of 10 to 80 parts by weight per 100 parts by weight of the microcapsules.

8. The coating body according to claim 6 or 7, characterized in that the amount of the microcapsules contained in the coating body is within the range of 0.5 to 10 parts by weight when the amount of the rubber material or thermoplastic resin material contained in the coating body is 100 parts by weight.

9. The microcapsules have an average particle size of 70 μm or less, 9. The coated body according to claim 6, wherein the coated body has thermal expansion cells having an average cell diameter of 200 μm or less formed by the expansion of the microcapsules during the extrusion molding.

10. 10. The coated body according to claim 6, wherein the volatile expanding agent is a hydrocarbon having 8 to 15 carbon atoms.

11. 11. The coating according to claim 1, wherein the material of the coating further contains a solid lubricant.

12. The coating according to claim 11, characterized in that the material of the coating contains the solid lubricant in an amount ranging from 0.1 to 5 parts by weight when the amount of the rubber material or the thermoplastic resin material is 100 parts by weight.

13. 13. The coating according to claim 11, wherein the solid lubricant is a fatty acid amide.

14. 14. The coated body according to claim 1, wherein each of the oily substances encapsulated in the microcapsules is an organopolysiloxane.

15. A weather strip comprising a coating according to any one of claims 1 to 14 formed on a surface of a substrate by extrusion molding, the coating being pressed against a sliding object, A weather strip, wherein the sliding object is any one of a glass member (including resin glass), a door panel, and a body panel.

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