JPH029075B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a fire-resistant packing material.

The fire-resistant packing material is, for example, a glazing gasket. A glazing gasket is a type of packing material that comes into contact around the glass plate and supports the glass plate within the metal sash when the glass plate is fitted into the sash.

Glazing gaskets are required to have various properties. For example, it is required to be flexible, have appropriate mechanical strength, have excellent weather resistance, and be easy to mold. Furthermore, recently there has been a demand for fire resistance and shape retention during heating.

Shape retention during heating refers to the property that when a glazing gasket comes into contact with flame, it will not burn or deform and flow, but will remain in its original shape and turn black. This property is effective in the event of a fire. Therefore, this property is referred to as fire resistance here.

Further explanation of fire resistance is as follows. If a glazing gasket is exposed to high temperatures or comes into contact with a fire,
Easily deforms and flows when heated. If the gasket flows, gas will circulate around the gasket, increasing the fire's strength. However, if the gasket simply turns black, gas will not circulate through the gasket, which will help prevent the spread of fire. that's why,
Glazing gasket materials have come to be required to have shape retention properties when heated.

However, it is not easy to find a material that satisfies the various properties described above. Until now, polyvinyl chloride has been exclusively used as the material for glazing gaskets, but it has not been possible to make polyvinyl chloride that retains its shape well when heated.

On the other hand, as an improved version of polyvinyl chloride,
Vinyl chloride-based graft polymers are known. It is also known that vinyl chloride-based graft polymers can be used for packing. It is described in, for example, Japanese Patent Publication No. 48-29630 and Japanese Patent Publication No. 48-25421. Among them, special public service in 1977
Publication No. 25421 describes that a packing made of a vinyl chloride graft polymer is a heat-resistant packing. However, these publications
Both of them state that the vinyl chloride-based graft polymer has the property of becoming a soft resin without adding a plasticizer, so it can be interpreted that they teach packing without adding a plasticizer. There is no information on what should be added to the vinyl chloride graft polymer and in what proportion to make packing.

The inventor set out to create a packing material that is not only excellent as a packing material in terms of flexibility, weather resistance, mechanical strength, and formability, but also excellent in shape retention when heated. It was. He then conducted tests on various materials. As a result, a known graft polymer obtained by graft polymerizing vinyl chloride to a copolymer resin of ethylene and vinyl acetate was used, and a plasticizer and an inorganic filler were blended in a specific ratio to form a composition. It has been found that this composition satisfies the above requirements. This invention was made based on such knowledge.

This invention is a graft polymer obtained by graft polymerizing vinyl chloride to a copolymer resin of ethylene and vinyl acetate, the copolymer resin containing the copolymer resin therein.
Graft polymer 100 containing 10 to 60% by weight
The present invention relates to a fire-resistant packing material made of a composition containing 30 to 100 parts by weight of a plasticizer and 10 to 100 parts by weight of an inorganic filler.

The graft polymer used in this invention is made from a copolymer resin of ethylene and vinyl acetate as one raw material. The properties of this copolymer resin vary depending on the copolymerization ratio of ethylene and vinyl acetate, the degree of polymerization, and the manufacturing method, but the graft polymer of the present invention has different properties. It may be used as a raw material. Among these, it is preferable to use a copolymer resin manufactured by a high-pressure method, and a copolymer resin having a high degree of polymerization, that is, a copolymer resin having a small melt index is preferable. In addition, the copolymer resin contains 40 to 90 mol% of ethylene and vinyl acetate.
It is preferable to use one containing 60 to 10 mol%.

The graft polymer used in this invention is obtained by graft-polymerizing vinyl chloride onto the above copolymer resin. This graft polymer is
It is known from No. 29630 and Japanese Patent Publication No. 48-25421. The properties of this graft polymer vary depending on the method of graft polymerization, the ratio of graft polymerization, etc. Among these, there is a limitation only on the ratio of graft polymerization, but there is no particular limitation on the polymerization method. The ratio of graft polymerization is 10 to 60% of the copolymer resin of ethylene and vinyl acetate.
It must contain 90 to 40% by weight of vinyl chloride. The reason for this is that if the copolymer resin is less than 10% by weight, the graft polymer will not have good shape retention during heating, whereas if the copolymer resin is more than 60% by weight, the flexibility and This is because weather resistance and fire resistance become inferior. Regardless of the method of graft polymerization, any product obtained by this method can be used.

As the plasticizer used in this invention, all plasticizers that are generally considered to be usable for polyvinyl chloride can be used. For example, phthalates,
Various plasticizers such as phosphoric acid type, fatty acid type, epoxy type, polyester type, etc. can be used. Among these plasticizers, it is preferable to use phosphoric acid-based plasticizers since the object of the present invention is fire resistance. To give a specific example, it is preferable to use tricresyl phosphate, trioctyl phosphate, or the like.

The plasticizer is used for 100 parts by weight of the graft polymer.
Add at a rate of 30 to 100 parts by weight. The reason is,
If the amount of plasticizer is less than 30 parts by weight per 100 parts by weight of the graft polymer, the resulting product will have poor flexibility.
On the other hand, if the amount exceeds 100 parts by weight, the resulting product will be too flexible, resulting in poor mechanical properties and poor fire resistance. The appropriate amount of plasticizer is specifically determined depending on the properties of the plasticizer used.

In this invention, an inorganic filler is blended into a graft polymer. As the inorganic filler, most of those commonly used in rubber or plastics can be used. Specific examples include fine powders of calcium oxide, magnesium oxide, calcium hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, and the like. In addition, fine powders such as talc, clay, asbestos, mica, dawsonite, and aluminum hydroxide can also be used. Among these, particularly preferred are calcium or magnesium oxides, carbonates, and silicates. Moreover, aluminum hydroxide is preferable in that it imparts flame retardancy to the graft polymer. All of these materials are used as fine powders as possible.

The inorganic filler is blended in a ratio of 10 to 100 parts by weight with respect to 100 parts by weight of the graft polymer. The reason for this is that if the inorganic filler is less than 10 parts by weight, the resulting product will have poor fire resistance and shape retention during heating, and conversely, if it is more than 100 parts by weight, the product obtained This is because it becomes less flexible. In order to blend the inorganic filler into the graft polymer, it is desirable to treat the inorganic filler with stearic acid, a silane coupling agent, a titanium coupling agent, etc. in advance. This is because by pre-treating with these materials, the polymer obtained by blending them becomes easier to mold, has an improved appearance, and has good mechanical properties.

The composition obtained by mixing the graft polymer with a plasticizer and an inorganic filler exhibits satisfactory properties such as flexibility, weather resistance, and mechanical strength, and also has good shape retention when heated. It also has good fire resistance. However, the fire resistance alone may not be completely satisfactory. In such cases, it is preferable to add a flame retardant or a flame retardant aid.

Any flame retardant or flame retardant aid that is commercially available for use in rubber or plastics can generally be used. However, since the packing material to which this invention is directed is often used outdoors, it is desirable to select and use a flame retardant or flame retardant aid that has good weather resistance. Examples of flame retardants include brominated polyols, phosphorus-containing polyols, halogen-containing phosphate esters, halogenated phthalic anhydrides, monoammonium phosphates, and boric acid. Other flame retardants include plasticizers such as tricresyl phosphate, triphenyl phosphate and chlorinated paraffin, and inorganic fillers such as antimony oxide.

The appropriate amount of these flame retardants is determined depending on the specific properties of the composition when it is blended with the graft polymer to form a composition. For example, in the case of a brominated organic compound with a bromine content of 7.7% by weight, 3 to 30 parts by weight of the brominated organic compound should be used for 100 parts by weight of the ethylene-vinyl acetate copolymer resin in the graft polymer. is desirable.

In order to improve the elasticity or mechanical properties of the graft polymer, an ethylene-vinyl acetate copolymer resin or a chlorinated polyethylene resin may be added to the composition used in the present invention. In particular, chlorinated polyethylene resin is advantageous because it also improves flame retardancy.

Furthermore, processing aids may be added to the composition used in the present invention in order to improve moldability. For example, there is a processing aid sold under the trade name Kane Ace by Kanebuchi Chemical Industry Co., Ltd., and Metablane, a trade name sold by Mitsubishi Rayon Co., Ltd.
A processing aid sold as P700 can be used.

The composition used in this invention is prepared by blending the above-mentioned ingredients in a predetermined proportion and then mixing thoroughly.
Thereafter, the mixture is sufficiently kneaded and molded into a desired shape.
In this way, the fire-resistant packing material of this invention is manufactured. For molding, machines generally used for processing soft vinyl chloride resin can be used as is.

The packing material according to the present invention is superior to conventional packing materials in flexibility, weather resistance, mechanical strength, ease of processing, etc., and has excellent fire resistance and shape retention when heated. In particular, when the packing material of this invention was used as a glazing gasket and a glass plate was actually fitted and fixed to a sash, the material was heated and the deformation state observed. It is excellent as a fire-resistant packing material because it only hardens and leaves almost no gaps.

Hereinafter, details of the packing material according to the present invention will be explained with reference to Examples. In the following examples, parts simply represent parts by weight.

Example 1 A graft polymer obtained by graft polymerizing vinyl chloride to an ethylene and vinyl acetate copolymer resin and containing 40% by weight of the copolymer resin was used as the graft polymer. To 100 parts of this graft polymer, 30 parts of dioctyl phthalate, 30 parts of tricresyl phosphate, 60 parts of calcium carbonate, and antimony trioxide.
20 parts and 3 parts of a calcium-zinc composite stabilizer, and after mixing this mixture, knead it to make a press sheet with a thickness of 1.5 mm, a width of 12 mm, and a length of 120 mm, and separately form a glazing channel. It was molded into.

The press sheets were tested for fire resistance.
The test method was to hang the above press sheet vertically, touch the flame obtained by burning propane with a Bunsen burner to the bottom end for 10 seconds, and then
After 10 seconds of separation and 10 seconds of contact, the flame was removed and the combustion state of the test piece during this period and shape retention during combustion were examined. These properties were divided into four levels based on the following evaluation criteria.

1 The shape does not change. Dimensional change is 1.2 times or less.

2 The shape does not change. It foams and becomes more than 1.2 times the size.

3 No dripping occurs, but the shape changes significantly.

4 It drips and its shape changes completely.

Furthermore, a practical test was conducted regarding the glazing channel. That is, a 3mm thick glass plate was fitted into the glazing channel, fixed to an aluminum sash, and heated in this state to 300℃ for 2 hours.
Subsequent changes in shape were observed. Shape retention was divided into two levels according to the following criteria.

A: It blackens while retaining its molded shape, and there is no gap between the aluminum sash and the glass plate.

B: Does not retain its molded shape. The glass plate used for the flow falls below the aluminum sash, creating a gap between the top of the glass plate and the sash.

In terms of flame resistance, the material of this example is self-extinguishing and is in the above 2nd stage, and in the practical test it was in the above A stage and was recognized as an excellent fire resistant packing material. .

Example 2 The same graft polymer as in Example 1 was used,
To 100 parts of this graft polymer, 70 parts of tricresyl phosphate, 30 parts of calcium carbonate, 30 parts of aluminum hydroxide, and a brominated flame retardant (bromine content 7.7
(% by weight) and 3 parts of a Ca-Zn composite stabilizer were blended, and this blend was processed in the same manner as in Example 1 to form a press sheet and a glazing channel, and each was tested for flame resistance. and a practical test.

In the flame resistance test, it was found to be self-extinguishing and in the grade 1, and in the practical test it was found to be in the grade A, making this material an excellent fire-resistant packing material.

Example 3 In this example, the same graft polymer as in Example 1 was used, and to 100 parts of this graft polymer, 30 parts of dioctyl phthalate, 30 parts of tricresyl phthalate, 60 parts of calcium carbonate, and a Ca-Zn-based composite were added. 3 parts of stabilizer were blended and the formulation was treated exactly as in Example 1 for flame resistance tests and practical tests.

In the flame resistance test, it was found to be combustible, but in the 2nd stage, and in the practical test, it was found to be in the A stage, and even though it does not contain flame retardants, it is considered a fire-resistant packing material. It was excellent.

Comparative Example 1 In this comparative example, polyvinyl chloride with a degree of polymerization of 1400 is used, and 10 parts of polyvinyl chloride, 80 parts of dioctyl phthalate, 60 parts of calcium carbonate, Ca-Zn
3 parts of a composite stabilizer were blended, and this blend was treated in exactly the same manner as in Example 1 to conduct a flame resistance test and a practical test.

In the fire flame resistance test, it was found to be combustible and at grade 4, and in the practical test it was found to be at grade B, indicating that it was inferior as a fire resistant packing material.

Comparative Example 2 In this comparative example, the same polyvinyl chloride as in Comparative Example 1 was used, in which 100 parts of polyvinyl chloride, 40 parts of dioctyl phthalate, 55 parts of tricresyl phosphate, 60 parts of calcium carbonate, and 100 parts of polyvinyl chloride were added. 30 parts of the brominated flame retardant used and 3 parts of the Ca--Zn composite stabilizer were blended, and this blend was treated in exactly the same manner as in Example 1 to conduct a flame resistance test and a practical test.

In the flame resistance test, it was recognized to be in the 3rd grade in terms of self-extinguishing properties, and in the practical test, it was recognized to be in the B grade, indicating that it was inferior as a fire resistant packing material.

Claims (1)

[Claims] 1 A graft polymer obtained by graft polymerizing vinyl chloride to a copolymer resin of ethylene and vinyl acetate, which contains 10 to 60% by weight of the copolymer resin.
A fire-resistant packing material made of a composition in which 30 to 100 parts by weight of a plasticizer and 10 to 100 parts by weight of an inorganic filler are mixed with 100 parts by weight of a graft polymer.