JP2007009038A - Foamed silicone rubber molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foamed silicone rubber molded article which enables molding to a shape intended in design even with the shape having hollow parts and does not cause the collapse of the shape in use. <P>SOLUTION: The foamed silicone rubber molded article 1 is in the form of a cylinder having hollow parts 2, and the hollow parts 2 have a partition wall 3 which is continued in the lengthwise direction. Further, the partition wall 3 positions nearly at the center of the hollow parts 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention mainly relates to a foamed silicone rubber molded body that can be used mainly as a packing, a gasket, a sealing material, etc., and in particular, it can be molded into a shape intended by design while having a hollow portion, It relates to those that do not collapse in shape when used.

  Conventionally, foamed silicone rubber moldings have excellent heat resistance and weather resistance, and are lightweight, so taking advantage of these properties, automotive parts such as gaskets and O-rings, packing for thermal equipment such as water heaters, and copying machine rolls. It is used as a construction gasket material such as a surface covering material, an airtight material, and a joint material, various sealing materials, various cushion materials, and the like.

  Among these, when using a foamed silicone rubber molded body as a relatively long member, in order to reduce the material cost and make the foamed silicone rubber molded body more flexible, a hollow part such as a hollow cylindrical shape is used. (For example, refer to Patent Document 1 and Patent Document 2).

JP 11-279312 A JP 2003-194229 A

  However, simply forming a shape having a hollow portion, when performing crosslinking or foaming at the time of manufacture, unless the conditions or equipment for crosslinking or foaming are set strictly, it becomes a deformed shape different from the shape intended by the design. End up. In addition, when the foamed silicone rubber molded body is crushed and used as a packing or the like, the shape is collapsed by having a hollow part, and the repulsive force as the foamed silicone rubber molded body is impaired because it collapses wide. This will reduce the sealing effect.

  The present invention has been made on the basis of such points, and the object of the present invention is to have a shape having a hollow portion, but it can be formed into a shape intended by design, and the shape is broken even during use. An object of the present invention is to provide a foamed silicone rubber molded body without any problems.

In order to achieve the above object, the foamed silicone rubber molded body according to claim 1 of the present invention is a cylindrical foamed silicone rubber molded body having a hollow portion, and the hollow portion has a partition wall continuous in the longitudinal direction. It is characterized by that.
Further, the foamed silicone rubber molded body according to claim 2 of the present invention is characterized in that the partition wall is located at a substantially central portion of the hollow portion.

According to the first aspect of the present invention, since the hollow portion has a continuous partition in the longitudinal direction, the hollow portion can be molded into the shape intended by the design. The shape does not collapse during use.
Further, according to the second aspect, since the partition wall is located at a substantially central portion of the hollow portion, it is possible to more effectively prevent the shape from being collapsed during use.

  Hereinafter, an example of an embodiment according to the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, there is a cylindrical foamed silicone rubber molded body 1 having a substantially bowl shape with a short diameter of 10 mm and a long diameter of 40 mm, and a hollow portion 2 having a thickness of 4 mm. In this hollow portion 2, there are three partition walls 3 having a thickness of 1 mm perpendicular to the major axis direction of the cross section, and these partition walls 3 are continuous in the longitudinal direction of the foamed silicone rubber molded body 1. Yes.

  As the material of the foamed silicone rubber molded body 1, various types of silicone rubbers are conventionally known, and these may be used alone or in combination of two or more. Moreover, you may mix | blend various additives, such as a filler, a pigment, a heat-resistant improver, a flame retardant, with this silicone rubber suitably as needed. As such, for example, silica, diatomaceous earth, titanium oxide, aluminum oxide, zinc oxide, iron oxide, cerium oxide, mica, clay, zinc carbonate, manganese carbonate, cerium hydroxide, glass beads, polydimethylsiloxane, alkenyl group Examples thereof include polysiloxane and polyorganosilsesquioxane. Further, for example, other rubber components such as ethylene-propylene rubber may be blended.

  In addition, when silicone rubber is used as a molded article, it is necessary to crosslink, so a crosslinking agent is blended in the silicone rubber, and this crosslinking agent is generally used for crosslinking silicone rubber. Anything may be used as long as it is used, and it is not particularly limited. Examples thereof include organic peroxides such as 2,5 dimethyl-2,5-bis (t-butylperoxy) hexane, di-t-butyl peroxide, and dicumyl peroxide. These are appropriately selected in consideration of the type of silicone rubber to be used.

  As the bubbles included in the foamed silicone rubber molded body 1, there are closed cells in which each bubble is present almost alone and open cells in which the bubbles communicate with each other. Some are preferred. If it is a closed cell, since the repulsive force as the foaming silicone rubber molded object 1 will increase, when it uses for packing, a gasket, etc., reliable sealing can be aimed at. Moreover, since waterproofness improves, it becomes more useful as waterproof packing. Moreover, since vibration-proof property improves, it can be preferably used also as a vibration-proof material.

  As a foaming method of silicone rubber, for example, a foaming agent that generates gas by decomposing or vaporizing at a predetermined temperature in advance is blended in silicone rubber, and this is heated and foamed. Examples include a method of foaming by dissolving gas in rubber and then reducing the pressure. These are appropriately selected in consideration of the intended purpose of the foamed silicone rubber molding to be obtained.

  In the case of a method of foaming with a foaming agent, examples of the foaming agent used include azobisisobutyronitrile (AIBN) and azodicarbonamide (ADCA). Although the compounding quantity of a foaming agent is not specifically limited, It is preferable to set it as 1-10 weight part with respect to 100 weight part of silicone rubber. If the blending amount of the foaming agent is less than 1 part by weight, there is a fear that foaming hardly occurs, and if it exceeds 10 parts by weight, it is considered that adjacent bubbles communicate with each other to form continuous cells.

  For molding the foamed silicone rubber molded body 1, various conventionally known molding methods may be used. For example, there is no particular limitation such as injection molding, press molding, extrusion molding, etc., but by extrusion molding from the viewpoint of excellent productivity. It is preferable to mold. In addition, a skin layer is formed on the surface of the foamed silicone rubber molded body 1 by molding, but if this skin layer is left, the waterproofness is improved and dust and dirt are difficult to adhere, Furthermore, the tensile strength can be improved.

  After being molded into a predetermined shape as described above, it is crosslinked by heating to obtain a foamed silicone rubber molded body 1. Among the foaming methods described above, in the case of foaming with a foaming agent, it is conceivable that foaming is performed together by heating during this crosslinking.

  In the present invention, as described above, since the partition wall 3 is present in the hollow portion 2 of the foamed silicone rubber molded body 1, when the resin is crosslinked or foamed by heating after molding, The shape can be maintained. Therefore, the shape is not deformed when crosslinking or foaming, and it can be formed into the shape intended by the design.

  As shown in FIG. 9, the end surface and the other end surface are joined with an adhesive or the like as shown in FIG. It can also be used.

  FIG. 10 is an example in which the above-described ring-shaped foamed silicone rubber molded body 1 is applied as a packing used in the outdoor unit 10 of a water heater. The outer surface of the outdoor unit 10 of the water heater is covered with an exterior plate 11, and a hole for passing the exhaust pipe 12 is formed in the upper portion of the exterior plate 11. In order to prevent rainwater, dust, etc. from entering the interior of the outdoor unit 10 of the water heater from the gap between the exterior plate 11 and the exhaust pipe 12, a ring-shaped foamed silicone rubber molded body is disposed around the exhaust pipe 12 1 is wound.

  In actual use, the foamed silicone rubber molded body 1 is placed on the packing holding plate 13 provided in the exhaust pipe 12, and the foamed silicone rubber molded body 1 is pressed against the packing holding plate 13 by the exterior plate 11. Thus, the foamed silicone rubber molded body 1 is compressed by about 50% in the major axis direction of the cross section, and the exterior plate 11 and the exhaust pipe 12 are sealed. In the case of the foamed silicone rubber molded body 1 according to the present invention, since the partition wall 3 is present in the hollow portion 2, it is supported by the partition wall 3 even when compressed in the major axis direction of the cross section. Will not spread. Therefore, the repulsive force as packing is not impaired, and reliable sealing as intended by the design can be achieved.

  Hereinafter, other embodiments according to the present invention are illustrated in FIGS. 3 to 8 show cross-sectional views taken along a plane perpendicular to the longitudinal direction of the foamed silicone rubber molded body 1. Of course, the present invention is not limited to these examples.

  In the form shown in FIGS. 1 and 2, the cross-sectional shape is substantially bowl-shaped, but the cross-sectional shape is not particularly limited as long as the foamed silicone rubber molded body 1 has a cylindrical shape having a hollow portion 2. For example, a circle as shown in FIGS. 3 and 4, an ellipse as shown in FIG. 5, a substantially quadrangle as shown in FIG. 6, a substantially triangle as shown in FIG. 7, a shape as shown in FIG. It is done.

  The partition 3 may be singular as shown in FIGS. 6 and 8, or may be plural as shown in FIGS. The shape of the partition wall 3 is not limited, and a plurality of partition walls 3 may be crossed as shown in FIGS. 5 and 6, or a plurality of partition walls 3 may be coupled as shown in FIGS. It may be in the form. The number and thickness of the barrier ribs 3 are appropriately set according to the purpose of use and the like because it becomes more difficult to be deformed if the barrier ribs 3 are thicker or thicker and the material cost can be reduced if the barrier ribs 3 are smaller or thinner. It will be. Although there is no limitation also about the position of the partition 3, if the partition 3 exists in the approximate center part of the hollow part 2 as shown to FIGS. 4-8, it will prevent more effectively that a shape collapses in use. Can do. Also, as shown in FIGS. 4, 5, and 7, when the plurality of partition walls 3 are crossed, when the foamed silicone rubber molded body 1 is crushed and used as a packing or the like, it is crushed from various directions. However, it is preferable because the shape does not collapse and it does not collapse widely. Also, as shown in FIGS. 3 and 5 to 8, if the cross-sectional shape of the partition wall 3 is a single straight line or a combination of a plurality of straight lines, the shape collapses while further reducing the material cost. Can be effectively prevented.

  As described above in detail, according to the present invention, there is provided a foamed silicone rubber molded body that can be molded into a shape intended by design even though it has a hollow portion, and the shape does not collapse even when used. can do. Therefore, the foamed silicone rubber molded body according to the present invention can be suitably used mainly as a packing, a gasket, a sealing material and the like. In addition, it can be preferably used as various cushions and vibration-proof materials.

It is a figure which shows embodiment of this invention and is a perspective view of a foaming silicone rubber molded object. It is a figure which shows embodiment of this invention and is sectional drawing of a foaming silicone rubber molded object. It is a figure which shows other embodiment of this invention, and is sectional drawing of a foaming silicone rubber molded object. It is a figure which shows other embodiment of this invention, and is sectional drawing of a foaming silicone rubber molded object. It is a figure which shows other embodiment of this invention, and is sectional drawing of a foaming silicone rubber molded object. It is a figure which shows other embodiment of this invention, and is sectional drawing of a foaming silicone rubber molded object. It is a figure which shows other embodiment of this invention, and is sectional drawing of a foaming silicone rubber molded object. It is a figure which shows other embodiment of this invention, and is sectional drawing of a foaming silicone rubber molded object. It is a figure which shows other embodiment of this invention, and is a perspective view which shows the example which made the foaming silicone rubber molded object the ring shape. It is a figure which shows the actual use example of the foaming silicone rubber molded object of this invention, (a) is a perspective view of the outdoor unit of a water heater, (b) is a BB 'perspective view in (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Foamed silicone rubber molded body 2 Hollow part 3 Partition 4 Joint part 10 Outdoor unit 11 of water heater 11 Exterior plate 12 Exhaust pipe 13 Packing holding plate

Claims (2)

A cylindrical foamed silicone rubber molded body having a hollow portion, wherein the hollow portion includes a partition wall continuous in a longitudinal direction. The foamed silicone rubber molded article according to claim 1, wherein the partition wall is located at a substantially central portion of the hollow portion.

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