JPH0644811U - 2-layer structure gasket - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a gasket that closes the joint between adjacent building exterior materials and exhibits excellent air-tightness and water-tightness, and that is easy to handle and does not contaminate the exterior material. . [Structure] A low-stress sponge layer 12 is provided on the surfaces of the gasket bodies 11, 13, and 14.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is a gasket that closes the gap between the joints of adjacent building exterior materials, and uses a low-stress sponge (high-foam sponge) provided on the surface of the gasket to follow the unevenness of the contact surface, for example, the concrete panel surface, and to achieve excellent The present invention relates to a two-layer structure gasket that ensures airtightness and watertightness.

[0002]

[Prior art]

 When building exterior materials are installed on the wall of a building, the gap between adjacent exterior materials is covered with a sealing material to prevent rainwater from entering.However, conventional sponge gaskets alone are not airtight and watertight. As shown in Fig. 2, the sponge gasket 23 is inserted and bonded at the boundary between the adjacent concrete panels 21 and 22, and the sealing material 24 for sealing is provided in the space outside this as shown in FIG. It is adhesively cured on top of 25.

[0003]

[Problems to be solved by the device]

 However, in this method, since the sealing material 24 is of a type that is usually moisture-cured, it takes a long time of 2-3 weeks to complete the curing, so the maintenance labor during that time is very difficult. In addition, since the sealant of the sealing material contains a large amount of low-molecular siloxane, there is a problem that the low-molecular siloxane leached after curing hardens the outer wall.

[0004]

[Means for Solving the Problems]

 The present invention proposes a novel gasket that solves such a disadvantage, and is based on a two-layer structure gasket characterized in that a low stress sponge layer is provided on the surface of the gasket body. For example, the gasket body is made of a high-stress sponge (low-foam sponge) made of a heat-vulcanized silicone rubber containing less low-molecular siloxane, and a low-stress sponge is provided on the surface.

FIG. 1A shows a typical example of a two-layer structure gasket of the present invention, in which 11 is a high stress gasket body and 12 is a low stress sponge layer. This is a form in which a low-stress sponge layer is provided on the top surface of a conventional type hollow gasket. FIG. 2B shows a low stress sponge layer 12 provided on the top surface of the solid gasket body 13. Further, FIG. 7C shows the case where the deformation type gasket body 14 of FIG.

For the purpose of the present invention, the gasket body is not limited to a sponge but may be a solid. If it is solid, a material with a rubber hardness of 40 to 80 ° is good, and the hardness of a molded product is adjusted by its wall thickness. On the other hand, in the case of a sponge, a foaming ratio of about 1.5 to 2 is suitable as a high-stress sponge, a holder for a low-sponge sponge, and a stress-applying body. The point is that the low-stress sponge part needs to be a support member for it so that it can be deformed sufficiently, and when a certain amount of stress is applied, it can also be deformed. The low-stress sponge preferably has a foaming ratio of 4 to 6 times, which allows high followability to the uneven surface of the panel. The low-stress sponge has a stress of about 3/4 to 1/4 that of the high-stress sponge.

As a foaming agent for obtaining such a sponge, for example, azo type azodicarbonamide, azobisisobutyronitrile, nitroso type N, N′-dimethyl N 2, N′-dinitrosoterephthalamide, N , N'-dinitrosopentamethylene methylenetetramine, which decomposes to generate nitrogen gas, is preferably an organic foaming agent, and the kind of these foaming agents is appropriately selected in consideration of decomposition temperature, amount of generated gas, etc. However, the addition amount is preferably in the range of 1 to 10 parts by weight with respect to 100 parts by weight of organopolysiloxan according to the required expansion ratio of the sponge.

In order to manufacture this gasket, the gasket body and the low-stress sponge layer are co-extruded so that the gasket body and the low-stress sponge layer are simultaneously bonded and integrated, or extruded and vulcanized. RTV that foams and cures at room temperature may be applied to the surface of the formed gasket body. The silicone rubber used here has an extremely low residual low molecular weight siloxane content compared to the sealant, but it is possible to almost eliminate leaching by using a lesser type.

This silicone rubber is preferably a methyl vinyl siloxane compound having a hardness of 20 to 80 °, which is represented by the average unit formula RaSiO _4-a , in which a = 1.90 to 2.05, R is a methyl group, an ethyl group, Alkyl group such as propyl group, butyl group, alkenyl group such as vinyl group and allyl group, aryl group such as phenyl group and tolyl group, or part or all of hydrogen atoms bonded to these carbon atoms are halogen atoms, Same or different unsubstituted or substituted monovalent hydrocarbon groups such as chloromethyl group substituted by cyano group, preferably 80 mol% thereof is methyl group, 0.1-0.5 mol% of which is vinyl group Organopolysiloxane having a viscosity at 25 ° C. of 100 CS or more, preferably 1,000 CS or more, may be used as a base. The terminal of this organopolysiloxane is preferably capped with a silanol group, a methyl group or a vinyl group, and particularly preferably a terminal capped with a vinyl group.

This silicone rubber composition is generally a mixture of the above-mentioned organopolysiloxane and a silica-based filler, and as the filler, fumed silica, wet silica, quartz powder, and diatomaceous earth are used. As typical examples, those having a particle size of 50 μm or less are preferable, and the addition amount may be in the range of 20 to 200 parts by weight with respect to 100 parts by weight of organopolysiloxane. The composition may contain a silane containing an alkoxy group, a silanol group or the like as a silica dispersant, and an inorganic pigment for coloring.

Further, this silicone rubber composition is supposed to contain a cross-linking agent for curing it, and benzoyl peroxide, monochlorobenzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, or a combination thereof is used. The thing is illustrated. Further, this silicone rubber composition is obtained by combining the organopolysiloxane with an organohydrogenpolysiloxane containing an aliphatic unsaturated group such as an alkenyl group and chloroplatinic acid, chloroplatinic acid and an alcohol, an aldehyde, an olefin, or vinyl siloxane. It may be of an addition reaction type such as a complex salt.

[0012]

[Action]

 If a heat-vulcanized silicone rubber with a low content of low-molecular weight is used for the gasket body, the amount of low-molecular weight leaching from the inside can be minimized and wall contamination can be minimized. To improve the airtightness and watertightness.

[0013]

[Effect of device]

 Since the conformability to the contact part with the exterior material for construction such as concrete panel is very good, an excellent sealing effect can be expected, the casting of sealant is not required, and the man-hours are significantly reduced. Since it is a small amount compared to the above, the effect such as wall contamination is extremely small, and so on.

[Brief description of drawings]

1A, 1B and 1C are sectional views showing various embodiments of a two-layer structure gasket according to the present invention.

FIG. 2 is an explanatory view of mounting a conventional gasket.

[Explanation of symbols]

11, 13, 14: Gasket body, 12: Low stress sponge layer,
21, 22: Concrete panel, 23: Sponge gasket, 24: Sealing material, 25: Backup material

Claims (1)

[Scope of utility model registration request] 1. A two-layer structure gasket, wherein a low-stress sponge layer is provided on the surface of the gasket body.