JP2010168440A - Thermally expansible and fire-resistant composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop a thermally expansible and fire-resistant composition that expands at high temperatures and covers or protects a part in need of protection by covering a construct, a steel structure, and other articles requiring flame retardancy and heat-resistance or by being inserted into junction. <P>SOLUTION: The thermally expansible and fire-resistant composition is composed of polymer cement comprising cement and a resin composition for cement admixing, and thermally expansible graphite and uses one selected from the group consisting of natural rubber latex, a thermoplastic resin emulsion, a thermosetting resin emulsion, and a re-emulsifiable powdery resin as the resin composition for cement admixing. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention covers buildings or steel structures, and other articles that require flame retardancy and heat resistance, or is inserted into a joint so as to expand at a high temperature to cover or protect a protection required portion. The present invention relates to a thermal expansion refractory composition suitable for the purpose.

  Polymers such as thermosetting resins and thermoplastic resins are widely used in electrical appliances, automotive parts, building materials, everyday products, etc., but these products are highly flame retardant from the viewpoint of safety. May be required. As a method for imparting flame retardancy to these polymers, in the building materials, the outer surface is coated with a non-flammable material. When the covering material is not integral and connection is required, it is necessary to protect the connection portion with a heat-resistant sealing member in order to make the connection portion nonflammable. In such a case, the connection portion is protected using a heat-resistant sealing member containing thermally expandable graphite.

  Most of the thermally expandable graphite in the market has a thermal expansion start temperature of around 200 ° C. If the processing temperature of synthetic rubber and synthetic resin containing this is high, 200 ° C is required. The release of sulfuric acid gas starts from before and after, causing corrosion of kneaders and molding machines. For this reason, conventional heat-expandable graphite is blended with polyethylene, polypropylene having a melting point of 200 ° C. or lower, polyurethane liquid at room temperature, etc. Could not be applied.

On the other hand, several treatment methods have been proposed for increasing the thermal expansion start temperature as thermally expandable graphite to be blended with a high melting point polymer.
For example, a thermally expandable graphite is proposed in which sulfuric acid and an oxidizing agent are used to react with graphite, phosphoric acid is added, and after washing and drying, the thermal expansion start temperature is 250 ° C. or higher (Patent Document 1). .

  In addition, without adding phosphoric acid to the reaction solution, the thermal expansion starts by mixing the solid neutralizer with the graphite that has been treated in a mixture of sulfuric acid and oxidant and then washed with an alkaline aqueous solution or water. There is a proposal of a thermally expandable graphite having a temperature of 270 ° C. or higher and a thermal expansion degree of 1000 ° C. of 70 to 99 cc / g (Patent Document 2).

Furthermore, as a method for producing thermally expandable graphite, after treating graphite in a mixture of sulfuric acid and an oxidizing agent, a solid neutralizing agent is mixed without washing with an alkaline aqueous solution or water that requires treatment of waste liquid. Thus, it has been proposed that a thermally expandable graphite having a thermal expansion start temperature of 300 ° C. or higher and a thermal expansion degree of 1000 ° C. of 50 to 150 cc / g can be produced (Patent Document 3).
As described above, the thermally expandable graphite requires a troublesome process to increase the thermal expansion start temperature, which causes an increase in cost.

On the other hand, a resin composition containing thermally expandable graphite is easily processed into a molded product such as a fireproof expansion sheet by a processing method used in ordinary resin molded products, for example, injection molding or extrusion molding. .
However, since the above-mentioned unfired thermally expandable graphite starts to expand at about 200 ° C., it may expand during kneading with the thermoplastic resin.
When used as a binder, these flame retardant resin compositions not only have low adhesion to concrete structures and the like, but also have poor workability and could not exhibit sufficient fire resistance. Furthermore, when it was constructed by a wet or semi-dry method, it took a long time to cure, resulting in poor work efficiency. Moreover, the biggest problem has been that the binder itself is in most cases a flammable material and is still insufficient to impart incombustibility.

  By the way, there is a polymer cement in which a large amount of resin is mixed with cement. If the kind of resin composition for cement admixture and the cement ratio are selected, the resin composition itself has good flame retardancy. These have extremely high strength and high toughness, and many have been proposed that achieve a large tensile strain capability and dramatically improve toughness. Polymer cement has the advantages of being heat resistant, impact resistant, wear resistant and flexible.

Japanese Patent Laid-Open No. 10-330108 JP 2006-69809 A JP 2007-45676 A

The present invention covers the surface of buildings, steel structures, and other flame retardant and fire resistant materials, or is inserted into a connection location to protect the location requiring fire resistance. It is a fire-resistant composition that is easy to handle and construct, and is effective as a heat-resistant sealing member that expands and expands the thermally expandable graphite when exposed to high temperatures in the event of a fire, etc. A thermal expansion refractory composition is provided.
These adhere well to various materials such as concrete, steel, cement, stone, steel, tile, and the mixing of polymer cement and thermally expandable graphite that expands at high temperatures is not only easy at room temperature, The premix can be handled as a slurry state by simply adding water, and can be molded using an injection mold or the like, and is a material excellent in workability. Further, the sheet-like cured body can be easily processed into a joint ring or the like by punching or the like.

The present invention
[1] A thermal expansion refractory composition comprising a polymer cement comprising a cement and a resin composition for admixture with cement, and thermal expansion graphite,
[2] The thermal expansion fire resistance according to [1], wherein the resin composition for admixture with cement is selected from the group consisting of natural rubber latex, thermoplastic resin emulsion and thermosetting resin emulsion. Sex composition,
[3] The thermoplastic resin emulsion is selected from the group consisting of an ethylene-vinyl acetate resin, a vinyl acetate-vinyl versatate resin, a styrene-acrylate resin, and a polyacrylate resin. The thermal expansion refractory composition as described in [2] above,

[4] The thermal expansion refractory composition according to the above [1], wherein the cement-mixing resin composition is a re-emulsifying powder resin.

[5] The thermally expanded refractory composition as described in any one of [1] to [3] above, which is used as a heat-resistant sealing member,
[6] The thermal expansion refractory composition as described in [4] above, wherein the heat-resistant sealing member is a joint ring of a joint portion of an outer tube of a refractory double-layer tube,

[7] The thermal expansion refractory composition according to any one of the above [1] to [3], which is used for filling and closing a void portion of a fire prevention compartment,
By solving this problem, the above problems were solved.

Select the type of thermal expansion refractory composition using thermal expansion graphite because it is necessary that the thermal expansion graphite does not expand at the processing temperature of the synthetic resin and synthetic rubber normally used as a binder for the refractory composition. However, since the thermal expansion refractory composition of the present invention uses polymer cement as a binder, it can be molded at room temperature, and the quality of the thermal expansion graphite (the thermal expansion start temperature is high). Is not necessary.)
Further, the polymer cement itself has excellent heat resistance as compared with a synthetic resin or the like, but the heat resistance is further improved by blending the heat-expandable graphite.
Therefore, the polymer cement blended with thermally expandable graphite has heat resistance, is flexible, and has advantages in terms of workability and workability.
The thermal expansion refractory composition of the present invention adheres well to various materials such as concrete, cement, stone, steel, tile, etc., so it is excellent in molding rings and mortar for filling voids in fire prevention compartments. It can be used as a refractory composition. In particular, even when exposed to high temperatures, since no halogen compounds harmful to the human body are contained, harmful gases are hardly generated.
In addition, the heat-resistant sealing member obtained by molding the thermal expansion refractory composition of the present invention is easy to manufacture and can be used as a thermal expansion sealing member.

Hereinafter, the present invention will be described in more detail.
The thermal expansion refractory composition of the present invention is not only used as a cured molded product, but may be prepared in situ, or may be used in the form of a premix.
The polymer cement used in the present invention is a hydraulic cement mixed with a considerably large amount of a resin composition for admixture of cement, and has various effects even when the mortar is fresh or cured. Cement. Specifically, even if long-term curing is not performed, it is excellent in strength expression. Particularly, unlike ordinary cement, tensile strength and bending strength are large, and elongation ability is also increased. The cement has a significant increase in long-term strength as hydration proceeds. The obtained polymer cement has good workability and a low water cement ratio to obtain slump and flow. Further, the blended resin composition for admixture of cement is excellent in impact resistance and wear resistance after being cured, and contributes to the development of strength and the reduction of drying shrinkage.

When the cement hardens, it reacts with and absorbs moisture in the cement-mixing resin composition and hardens. The resulting polymer cement contains a resin composition for admixture with cement, but has the advantage of being heat-resistant and flexible, and various materials such as concrete, cement, stone, steel, and tile. Adhere well.
Polymer cement can maintain good flame retardancy and non-flammability by selecting the type of resin composition for admixture of cement and the blending ratio with cement, but it must contain heat-expandable graphite. This further improves the heat resistance.

  The hydraulic cement used in the present invention is an inorganic powder that is hardened by a hydration reaction in the presence of water. Specifically, ordinary portland cement, early-strength Portland cement, ultra-early-strength Portland cement, intermediate Various Portland cements such as hot Portland cement, sulfate-resistant Portland cement, fly ash, siliceous mixed materials, and various Portland cement based mixed cements such as blast furnace slag (for example, fly ash cement, silica cement) , Blast furnace cement, etc.), alumina cement, and various fast-curing cements. Considering the curing time after construction and the effect of the present invention, those having excellent strength development characteristics in a short period of time, such as early strong Portland cement and ultra-early strong Portland cement, are preferable.

The resin composition for admixture of cement used in the present invention is obtained by dispersing various polymers in an aqueous medium. In the present invention, there is no particular limitation, and known ones can be used as appropriate.
The resin composition for admixture with cement greatly affects the flexibility, moldability, and shape retention of the resulting thermal expansion refractory composition.

Specifically, natural rubber latex, thermoplastic resin emulsion, and thermosetting resin emulsion can be used as the synthetic resin composition for cement admixture used in the present invention.
For premix, re-emulsifying powder resin is suitable, for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate. , Fluoroplastics, thermoplastic acrylic resins, thermoplastic polyesters, thermoplastic polyamides, thermoplastic urethane resins, acrylonitrile-butadiene copolymers, styrene-butadiene copolymers, acrylonitrile-butadiene-styrene copolymers, etc. Curable resin such as urethane resin, melamine resin, thermosetting acrylic resin, urea resin, phenol resin, epoxy resin, thermosetting polyester; urethane resin prepolymer, epoxy resin prepolymer, melamine resin prepolymer, urea resin The Polymers, phenolic resin prepolymer, diallyl phthalate prepolymer, acrylic oligomer, polyisocyanate, methacrylic ester monomers, prepolymers such as diallyl phthalate monomer; oligomer, a synthetic resin precursor monomers, and the like.

  When the resin composition for admixture of the present invention is rubber-based, it is natural (natural rubber), recycled rubber or synthetic rubber (acrylonitrile butadiene rubber, styrene butadiene rubber, chloroprene rubber, butyl rubber, urethane rubber, as an aqueous polymer dispersion. And methyl methacrylate butadiene rubber) latex. These may be used alone or in combination of two or more.

The mixing method of the resin composition for admixture with cement is not particularly limited, but for example, it is preferably used after being dispersed in cement or water in advance.
Therefore, when preparing a mortar for a thermally expandable refractory composition from cement and thermally expandable graphite, it is possible to use an aqueous polymer dispersion instead of the re-emulsifying powder resin. In this case, it is necessary to add the aqueous polymer dispersion together with the water-based polymer dispersion without adding it to the premix mortar for building materials in advance.

The polymer cement used in the present invention has an optimum blending depending on the use, but the resin composition for cement admixture is usually 10 to 70 parts by weight in terms of solid content with respect to 100 parts by weight of powder such as hydraulic cement. 10 to 50 parts by weight is more preferable. If the amount is less than 10 parts by weight, the mortar may not be expected to be rebounded or the adhesion strength may not be improved. On the other hand, if the amount exceeds 60 parts by weight, further improvement in the effect may not be expected.
It is necessary to change the amount of water to be blended in the thermal expansion refractory composition of the present invention depending on the intended use and purpose.

Thermally expandable graphite is a powder of natural graphite, pyrolytic graphite, etc., treated with an inorganic acid such as sulfuric acid or nitric acid and a strong oxidizing agent such as concentrated nitric acid or permanganate. It is a maintained crystalline compound. These are thermally expanded 100 times or more when exposed to temperatures of about 200 ° C. or higher.
In addition to the deoxidation treatment, these natural graphite and pyrolytic graphite powders can be used in various varieties other than the neutralized type.
The particle size of the thermally expandable graphite is preferably about 20 to 400 mesh. When the particle size is smaller than 400 mesh, the flexibility of the thermally expandable refractory composition is increased, but the degree of expansion of the thermally expandable graphite is decreased, and the resulting thermally expandable refractory composition does not expand sufficiently in the event of a fire. On the other hand, if the particle size is larger than 20 mesh, the degree of expansion increases, but the dispersibility deteriorates, and the elasticity of the obtained thermally expandable refractory composition may be lowered.

  The content of the heat-expandable graphite can be appropriately set depending on the composition of the polymer cement, the desired expansion ratio, etc., but is usually 5 to 30 parts by weight, preferably 10 to 25 parts per 60 parts by weight of the polymer cement. Good use of parts by weight. When the content of the thermally expandable graphite is less than 10 parts by weight, the obtained thermally expanded refractory composition may not be sufficiently thermally expanded at the time of fire, while when it exceeds 30 parts by weight, the thermal expansion ratio becomes large. However, physical properties such as strength of the obtained thermal expansion refractory composition tend to decrease.

  In the present invention, a flame retardant added to a synthetic rubber, a synthetic resin or the like can be used in combination as necessary. Such flame retardants include halogen-based, phosphorus-based, and inorganic-based flame retardants, but inorganic flame retardants that do not generate harmful gases (such as carcinogenic substances) even in the event of a fire are preferable. Examples of the inorganic flame retardant include aluminum hydroxide, calcium hydroxide, boric acid compound, and the like, and may be appropriately selected from the temperature required from the fire resistance and the expansion start temperature of the thermally expandable graphite.

  The above-mentioned thermally expanded refractory composition can be produced into a shape suitable for use to produce a heat-resistant sealing member. For example, a plate-like elastic body having heat resistance can be produced by spreading the thermally expanded refractory composition as a slurry into a plate shape and curing it. This can be punched into a necessary shape such as a joint ring and used as a heat-resistant sealing member. Further, after forming into a Baumkuchen shape, it may be sliced into round slices. Furthermore, the slurry may be press-fitted into a molding die and molded to form a heat-resistant sealing member.

  As an application, the outer surface of the inner tube made of synthetic resin is covered with an outer tube having fire resistance and heat insulation, each consisting of a straight tube and a joint configured as a fire-resistant double-layer tube, and the joint side end of the straight tube In the joint structure of the refractory double-layer pipe inserted into the inner pipe of the joint, when the refractory double-layer pipe is joined, a joint ring provided at the outer pipe end of the refractory double-layer pipe joint, It can be used as a void filler or the like penetrating through a fire prevention section (fireproof floor, wall, etc.) of a building.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not restrict | limited by the following Example.
[Examples 1 and 2]
As polymer cement, “Ceretat (registered trademark) G: Cement mortar powder and acrylic-EVA emulsion (solid content concentration 56%)”, expandable graphite for non-halogen flame retardant (grade: SYZR 801; Sanyo Trading Co., Ltd.) It was confirmed that the thermal expansion refractory composition consisting of was mixed in a sufficiently uniform manner, placed in a sheet form in a sheet form, cured at room temperature for 4 days, and cured.
The sheet was cut into 10 mm × 10 mm and used as a sample. The sample was heat-treated in an oven at 150 ° C., and then evaluated by visual observation and finger touch. The results are shown in Table 1.

[Comparative example]
Portland cement, sand and water were mixed in the proportions shown in Table 1, and were made into a sheet-like cured body in the same manner as in the Examples, and then cut into 10 mm × 10 mm to obtain samples. The sample was heat-treated as in the example. The results are shown in Table 1.

The thermal expansion refractory composition of the present invention adheres well to various materials such as concrete, steel, cement, stone, steel, tile, etc., and the mixture of polymer cement and thermally expandable graphite that expands at high temperatures, In addition to being easy at room temperature, the premix can be handled as a slurry by simply adding water, and can be cast, molded using a mold, etc., and is extremely excellent in workability. Further, the sheet-like cured body can be easily processed into a joint ring or the like by punching or the like. In addition, since it does not contain halogen compounds that are harmful to the human body, it generates almost no harmful gases even when exposed to high temperatures.
In addition, the heat-resistant sealing member obtained by molding the thermal expansion refractory composition of the present invention is easy to manufacture and can be used as a thermal expansion sealing member.
Therefore, the thermal expansion refractory composition of the present invention expands at a high temperature by inserting a building, a steel structure, or other articles that require flame resistance and heat resistance into a covering or joining portion, It can be widely used as a refractory composition and a heat-resistant sealing member for covering or protecting the protection part.

Claims (7)

  A thermal expansion refractory composition comprising a polymer cement comprising a cement and a resin composition for admixture with cement, and thermal expansion graphite.   2. The thermal expansion refractory composition according to claim 1, wherein the resin composition for admixture of cement is selected from the group consisting of natural rubber latex, thermoplastic resin emulsion and thermosetting resin emulsion.   The thermoplastic resin emulsion is selected from the group consisting of an ethylene-vinyl acetate resin, a vinyl acetate-vinyl versatate resin, a styrene-acrylate resin, and a polyacrylate resin. The thermal expansion refractory composition according to claim 2.   The thermal expansion refractory composition according to claim 1, wherein the resin composition for admixture with cement is a re-emulsifying powder resin.   It is used as a heat resistant sealing member, The thermal expansion fireproof composition in any one of Claims 1-3 characterized by the above-mentioned.   The thermal expansion refractory composition according to claim 4, wherein the heat-resistant sealing member is a joint ring of a joint portion of the outer tube of the refractory double-layer tube.   The thermal expansion refractory composition according to any one of claims 1 to 3, wherein the thermal expansion refractory composition is used for filling and closing a void portion of a fire prevention compartment.