JPH049196B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a gasket composition for a fire door, the main components of which are a nonflammable inorganic compounding agent, powdered rubber, and a polyvinyl chloride resin. The object of the present invention is to create a composition containing as main components a nonflammable inorganic compounding agent, powder rubber, and polyvinyl chloride resin suitable for fire doors that can be easily extruded, injected, or calendered. It can be molded and used as a gasket for fire doors. Conventional gaskets for fire doors include: (1) The most common method is to mix flame retardants into putty and use it for fire doors, but with this method, the workability of fitting the glass is poor, and the putty falls off before it dries. There are many problems such as damage to the glass due to expansion and contraction cycles after drying. (2) Another possibility is to mix flame retardants into rubber such as chloroprene, mold and vulcanize it, and use it for fire doors, but this method requires relatively high raw material costs;
Moreover, since it is necessary to take the troublesome steps of extrusion molding and vulcanization, the processing cost is high, so it is hardly put into practical use. (3) In addition, there are so-called soft PVC gaskets made of conventional polyvinyl chloride resin mixed with ordinary plasticizers and fillers, and soft PVC gaskets containing flame retardants made by simply adding a flame retardant to it.
Does not satisfy JIS A-1302 "Fire protection test method for noncombustible structural parts of buildings". This is because the polyvinyl chloride resin softens and flows due to heat, so it cannot hold the glass and the glass may fall, or a gap may be created through which the fire can spread to the back. As a result of various studies, the present inventor found that a resin composition whose main components are a nonflammable inorganic compound, powdered rubber, and polyvinyl chloride resin can be easily molded and used for gaskets for fire doors. Heading The present invention has been arrived at. This composition does not require the troublesome vulcanization process unlike ordinary rubber, and therefore can be easily gasket-molded by simply passing the compound through an extruder fitted with a designated mold at the tip, just like ordinary soft PVC compounds. You can get things. Additionally, this gasket completely passes the aforementioned JISA-1302 ``Fire protection test method for noncombustible structural parts of buildings''. That is, the present invention uses polyvinyl chloride resin 100
30 to 500 parts by weight of powdered rubber and 50 to 500 parts by weight
This is a gasket composition for fire doors characterized by containing 500 parts by weight of a nonflammable inorganic compounding agent as a main component. In the present invention, as the polyvinyl chloride resin, so-called straight vinyl chloride made by polymerizing only vinyl chloride monomers is mainly used, but vinyl acetate, α
Copolymerized PVC obtained by copolymerizing -olefin or other comonomers, grafted PVC obtained by graft polymerizing vinyl chloride onto other polymers, chlorinated PVC obtained by chlorinating polyvinyl chloride, and the like may also be used. As the powdered rubber, unvulcanized rubber such as acrylonitrile-butadiene copolymer rubber, chloroprene rubber, styrene-butadiene copolymer rubber, natural rubber, or a powdered product of vulcanized rubber is used. Particularly suitable are acrylonitrile-butadiene copolymer rubber or chloroprene rubber. These powdered rubbers are required in an amount of 30 parts by weight or more per 100 parts by weight of the polyvinyl chloride resin. If the amount of powdered rubber is less than 30 parts by weight, due to the thermal softening property of polyvinyl chloride resin, a gasket molded from the composition will soften when exposed to flame, causing the gasket to lose its shape. If the glass comes off or the fire spreads to the back, it will no longer meet the requirements of JIS-A-1302. It is preferable that the powdered rubber is 30 parts by weight or more because the gasket will not lose its shape due to curing due to crosslinking reaction when exposed to flame. However, if the amount of powdered rubber exceeds 500 parts by weight, the good shapeability characteristic of polyvinyl chloride resin during extrusion molding is lost, and gasket molding becomes impossible. Examples of nonflammable inorganic compounding agents (hereinafter simply referred to as inorganic compounding agents) include calcium carbonate, clay, aluminum hydroxide, magnesium hydroxide, and antimony trioxide, which also has the effect of being a flame retardant. The amount of the inorganic compounding agent added is 50 to 500 parts by weight per 100 parts by weight of the polyvinyl chloride resin. If it is less than 50 parts by weight, there will be less inorganic chaff left in the position after combustion and its shape retention will be poor, and if it exceeds 500 parts by weight, the processability of the composition will be reduced. In addition to polyvinyl chloride resins, powdered rubber, and inorganic compounding agents, we also process plasticizers such as DOP and TCP, lubricants, stabilizers, and ethylene/vinyl acetate resins used as compounding agents for polyvinyl chloride resins. Auxiliary agents, anti-aging agents, extender oils, fillers and the like which are often used as compounding agents for rubber may also be added as appropriate. Of course, inorganic flame retardants can also be added in addition to the usual brominated flame retardants. The gasket composition for fire doors of the present invention is manufactured by almost conventional methods for producing polyvinyl chloride resin compounds, except for using the above-mentioned various compounding agents, and by molding methods such as extrusion molding, injection molding, and glow molding. It can be molded. According to the present invention, 100 parts by weight of polyvinyl chloride resin,
When manufacturing a gasket for a fire door from a composition containing 30 to 500 parts by weight of powdered rubber and 50 parts by weight or more of an inorganic compounding agent, the materials used can be easily molded using known thermoplastic plastic molding methods. It can be used stably for a long period of time without impairing its physical properties. This gasket for fire doors can be fitted with glass, making it much easier to fit the glass in than with conventional putty. Examples will be explained below. All parts are by weight. Example 1 Polyvinyl chloride (Denkavinyl #SS-110)
100 (parts) Powdered NBR (acrylonitrile butadiene copolymer rubber) 100 DOP (dioctyl phthalate) 100 Antimony trioxide 50 Calcium carbonate 250 Epoxidized soybean oil 3 Barium stearate/zinc stearate = 1/
1 Mixture 3 The above raw materials were mixed and kneaded at 160°C. This was extruded using an extrusion molding machine at 180°C to obtain a gasket for a fire door. Examples 2 to 7 were prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1.
Tests of Comparative Examples 1 to 3 were conducted. The results are shown in Table 1. If the amount of powdered rubber is too small (Comparative Example 1)
Fire prevention performance is poor, and if too much (Comparative Example 2), workability becomes poor. It is also seen that when the amount of the inorganic compounding agent is less than 50 parts by weight (Comparative Example 3), the fireproof performance deteriorates. On the other hand, Examples 1 to 7 are preferable because they all satisfy both fire prevention performance and moldability.

【table】

【table】

Claims (1)

[Claims] 1. 100 parts by weight of polyvinyl chloride resin and powdered rubber
30-500 parts by weight and 50-500 parts by weight of nonflammable inorganic compounding agents
A gasket composition for a fire door, characterized in that the main component is part by weight. 2. The gasket composition for a fire door according to claim 1, wherein the powdered rubber is acrylonitrile-butadiene copolymer rubber or chloroprene rubber. 3 The nonflammable inorganic compounding agent is antimony trioxide,
The gasket composition for a fire door according to claim 1, which is aluminum hydroxide or calcium carbonate. 4. The gasket composition for fire doors according to claim 1, which contains an ethylene/vinyl acetate resin as a subcomponent. 5. The gasket composition for a fire door according to claim 1, which contains tricresyl phosphate as a subcomponent.