JP4669573B1 - Thermally expandable joint material for fire protection - Google Patents

Abstract

It is possible to block smoke and heat by closing a gap even in a situation where the environmental temperature at the initial stage of a fire does not reach 200 ° C., and has excellent shape retention after expansion, and halogen during combustion. Provided are a thermally expandable resin composition for fire protection and a thermally expandable joint material for fire protection that does not generate harmful gases such as gas.
SOLUTION: To 100 parts by mass of a rubber component containing 25 to 80% by mass of butyl rubber, 5 to 60% by mass of butyl rubber and vulcanizable rubber, and 15 to 70% by mass of a styrenic thermoplastic elastomer. Thermally expandable graphite having an expansion start temperature of 130 to 150 ° C .: 20 to 75 parts by mass, aluminum hydroxide: 15 to 60 parts by mass, boric acid: 20 to 70 parts by mass, the aluminum hydroxide and boric acid Inorganic fillers other than: 20-60 parts by mass and a vulcanizing agent and a vulcanization accelerator: 0.02-5 parts by mass, respectively, are molded and processed without being vulcanized. A joint material with a degree of 10% or less is used.
[Selection figure] None

Description

The present invention relates to a fire protection thermally expandable joint material using heat-expandable resin composition. More specifically, the present invention relates to a fireproof material attached to a door, a gap portion, a vent hole, and the like of an opening such as a door and a shutter.

  In the event of a fire, the flame spreads rapidly through the connecting parts of residential buildings and ship corridors, vents, railway vehicles, etc., and promotes the spread of fire to the upper floors, adjacent rooms, and connected vehicles. In order to prevent such a situation, a fire door, a fire shutter, a fire barrier, or the like is installed. As these fire doors, fire shutters, and fire barriers, sandwich structures are generally used in which a heat insulating foam of synthetic resin is inserted between a surface material and a back material made of a thin plate metal. .

  In addition to such structures, joint materials have also been developed that are stuck around doors or shutters or around frame parts and that thermally expand to close the gap when a fire occurs and the temperature rises (for example, , See Patent Document 1). However, the conventional fireproofing material using a thermally expansible material expands when it reaches a high temperature of 200 ° C. or higher, and closes the gap to prevent the spread of fire. No expansion occurs at a temperature lower than 200 ° C. For this reason, there has been a drawback that it is not possible to prevent the intrusion of smoke at the early stage of the fire.

  Therefore, conventionally, a specific amount of thermally expandable graphite having a thermal expansion start temperature of 140 to 180 ° C. subjected to neutralization treatment and a phosphorus compound is blended to start expansion at a temperature lower than before. A fire-resistant sheet-like molded body has been proposed (see Patent Document 2).

JP 2005-98041 A Japanese Patent No. 3838780

  However, according to the technique described in Patent Document 2 described above, it is possible to expand at less than 200 ° C., but on the other hand, there is a problem that the shape retention after thermal expansion is poor. In order to solve this problem, Patent Document 2 proposes a recipe for blending a halogenated resin, but this method has a problem that halogen gas is generated in the combustion gas.

  Moreover, in the fire-resistant sheet-like molded object described in Patent Document 2, neutralized thermally expandable graphite is used, but in this case, a step of further neutralizing the acid-treated graphite is required. There is a problem that the manufacturing cost increases.

Therefore, the present invention is capable of blocking smoke and heat by closing the gap even in a situation where the environmental temperature at the initial stage of the fire does not reach 200 ° C., and has excellent shape retention after expansion, a main object to provide a harmful gas generated such Ibo fire heat expandable joint compound, such as halogen gas during combustion.

  In order to solve the above-described problems, the present inventor has conducted extensive experiments and has completed the following thermally expandable resin composition and joint material.

That is, the resin composition used in the thermally expandable joint material for fire protection according to the present invention is butyl rubber: 25 to 80% by mass, rubber co -vulcanizable with the butyl rubber: 5 to 60% by mass, and styrenic thermoplastic. Elastomer: Thermal expansion graphite having an expansion start temperature of 130 to 150 ° C .: 20 to 75 parts by mass with respect to 100 parts by mass of a rubber component containing 15 to 70% by mass, and aluminum hydroxide as a temperature rise inhibitor : 15-60 parts by mass , as a shape retention agent after thermal expansion, boric acid: 20-70 parts by mass, inorganic filler (excluding aluminum hydroxide and boric acid) : 20-60 parts by mass, vulcanizing agent and Vulcanization accelerator: each contains 0.02 to 5 parts by mass.

And the thermally expandable joint material for fire protection according to the present invention is obtained by molding the above-described thermally expandable resin composition without vulcanization, and the thermally expandable graphite is unexpanded. The rubber component is present in a state, and the rubber component has a vulcanization degree of 10% or less, and is naturally vulcanized in a use environment.
As the rubber that can be co-vulcanized with the butyl rubber blended in the joint material, for example, at least one rubber selected from the group consisting of natural rubber, ethylene-propylene-diene rubber, and styrene-butadiene rubber may be used. it can.
As the inorganic filler, for example, calcium carbonate can be used.
Furthermore, when the rubber component is naturally vulcanized by holding for 120 days at a temperature of 50 ° C., the rubber component may have a vulcanization degree of 70% or more .
Furthermore, for example, the expansion may be started under a temperature condition of 140 to 160 ° C.
And this joint material can be affixed on a door, a door frame part, the clearance gap between a door and a wall, or a vent hole, for example.

  According to the present invention, since expansion starts at a temperature of less than 200 ° C., the gap between doors, shutters, and vents is blocked at the initial stage when the environmental temperature after the fire has not reached 200 ° C. Realize a fire-proof material that can block fire and prevent fire spread, and that the expanded layer after thermal expansion has a sufficient shape and does not contain harmful components such as halogen in the generated combustion gas. Can do.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that the present invention is not limited to the embodiments described below.

(First embodiment)
First, a thermally expandable resin composition (hereinafter also simply referred to as a composition) according to the first embodiment of the present invention will be described. The composition of the present embodiment is used for fire-resistant applications, and is an expansion start temperature with respect to 100 parts by mass of a butyl rubber, a rubber component co -vulcanizable with the butyl rubber, and a styrene-based thermoplastic elastomer. Is obtained by blending specific amounts of 130-150 ° C. heat-expandable graphite, aluminum hydroxide, boric acid and other inorganic fillers, vulcanizing agents, and vulcanization accelerators.

[Butyl rubber: 25 to 80% by mass of the entire rubber component]
Butyl rubber is one of the rubber components of the composition of the present embodiment, and by blending this, the moldability of the composition is improved, and flexibility and waterproofness are imparted to the molded body (joint material). can do. Moreover, the adhesiveness of a molded object (joint material etc.) can also be adjusted by changing butyl rubber content.

  However, if the butyl rubber content is less than 25% by mass of the total rubber component, the moldability will deteriorate and the surface of the molded product (such as joint material) will become rough, or the molded product (such as joint material) will have flexibility and waterproofness. May be insufficient. On the other hand, when the butyl rubber content exceeds 80% by mass, there arises a problem that when a molded body (such as a joint material) is exposed to a high temperature environment such as in summer, it is easily deformed due to plasticization. Therefore, the butyl rubber content is 25 to 80% by mass of the entire rubber component.

  On the other hand, if the butyl rubber content in the rubber component is more than 60% by mass, the composition will exhibit tackiness. Therefore, when a molded body such as a joint material is used, without using an adhesive or a pin, It can be attached to the adherend by its own adhesive strength. In addition, when the content of butyl rubber in the rubber component is 25 to 60% by mass, the tackiness is reduced. Therefore, when mounting on an adherend after molding, use an adhesive seal, an adhesive, or a metal fitting such as a nail or a pin. It is desirable to use it.

[Rubber that can be vulcanized with butyl rubber: 5 to 60% by mass of the entire rubber component]
In the composition of the present embodiment, rubber that can be co -vulcanized with butyl rubber is used as a rubber component in order to ensure the mechanical strength of the molded body and to obtain suitable tackiness for use in, for example, fireproof joint materials. It is blended. Examples of such rubber include natural rubber, ethylene-propylene-diene rubber, and styrene-butadiene rubber. These rubbers may be used alone, but two or more kinds may be mixed and used in order to improve kneadability and moldability. Furthermore, among these, it is particularly preferable to use ethylene-propylene-diene rubber, whereby the kneadability and moldability can be further improved.

However, when the content of rubber that can be co -vulcanized with butyl rubber is less than 5% by mass of the entire rubber component, the strength is lowered, and deformation and breakage tend to occur during processing. Moreover, when it exceeds 60 mass%, a moldability will fall and the molded object obtained will be inferior in external appearance. Therefore, the content of rubber that can be co -vulcanized with butyl rubber is set to 5 to 60 mass% of the entire rubber component.

[Styrenic thermoplastic elastomer: 15 to 70% by mass of the entire rubber component]
Styrenic thermoplastic elastomers have the effect of improving moldability, strength, flexibility, dimensional stability, and the like. Specifically, the styrene resin portion, which is a hard segment in the thermoplastic elastomer, is melted during the molding process, exhibits fluidity, and exhibits an effect of improving moldability. Further, at normal temperature, the rubber part, which is a soft segment, exhibits rubber elasticity and exhibits an effect of improving strength and flexibility, and the hard segment improves the dimensional stability of the molded product.

  Furthermore, when a styrenic thermoplastic elastomer is added, the hard segment is melted by heat in the event of a fire, and the effect of temporarily holding the thermally expanded expandable graphite can be obtained. However, when the content of the styrenic thermoplastic elastomer is less than 15% by mass of the entire rubber component, the moldability deteriorates, the molded article has poor appearance, and the shape retention after expansion in a fire is low. It becomes. Similarly, when the content of the styrenic thermoplastic elastomer exceeds 70% by mass, the moldability is lowered and the processing becomes difficult.

  As the styrenic thermoplastic elastomer added to the composition of the present embodiment, for example, a block copolymer composed of a polymer block mainly composed of a vinyl aromatic compound and a polymer block mainly composed of a conjugated diene compound is used. be able to. Examples of the vinyl aromatic compound include styrene, p-methylstyrene, α-methylstyrene, vinylxylene, and the like. These may be used alone or in combination of two or more. Of these vinyl aromatic compounds, styrene is particularly preferable.

  On the other hand, examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and the like. It may be used in combination of more than one species. Of these conjugated diene compounds, 1,3-butadiene is particularly preferable.

  Moreover, 20 / 80-60 / 40 is preferable and, as for the ratio (hard segment / soft segment) of the hard segment and soft segment which comprise a styrene-type thermoplastic elastomer, More preferably, it is 25 / 75-40 / 60. If a styrene thermoplastic elastomer having a hard segment of less than 20% is used, moldability may be reduced, and if a styrene thermoplastic elastomer having a hard segment of more than 60% is used, flexibility may be reduced. Sometimes.

[Thermal expandable graphite: 20 to 75 parts by mass]
Thermally expandable graphite is a component that imparts thermal expandability to the composition of the present embodiment and its molded body, and is a crystal that maintains a graphite layered structure obtained by treating natural graphite powder with an inorganic acid and a strong oxidizing agent. A compound. Moreover, in the composition of this embodiment, the thing whose expansion start temperature is 130-150 degreeC is used especially.

  When this thermal expansion start temperature is less than 130 ° C., it is close to the kneading temperature and the molding temperature, so that a partial thermal expansion occurs during the kneading or molding process, and the resulting composition or molded body has a low coefficient of thermal expansion. . In addition, if a thermal expansion graphite having a thermal expansion start temperature exceeding 150 ° C. is used, the thermal expansion start temperature of the composition or the molded body is increased. It cannot be obtained.

  On the other hand, the particle size of the thermally expandable graphite is preferably about 20 to 400 mesh. If the particle size of the thermally expandable graphite is smaller than 400 mesh, the degree of thermal expansion when formed into a molded body may be insufficient. Further, when the particle size of the thermally expandable graphite is larger than 20 mesh, the dispersibility may be lowered when kneaded with rubber.

When the content of this heat-expandable graphite is less than 20 parts by mass per 100 parts by mass of the rubber component, the thermal expansion ratio at the time of fire is reduced, and when it exceeds 75 parts by mass, the thermal expansion ratio is increased, While the intensity | strength of the formulation to be reduced falls, a moldability falls and a surface state worsens. Therefore, the content of the thermally expandable graphite is 100 parts by mass of the rubber component.
20 to 75 parts by mass.

[Aluminum hydroxide: 15-60 parts by mass]
Aluminum hydroxide has an effect of suppressing temperature rise by an endothermic reaction due to a dehydration reaction during heating. However, when the content per 100 parts by mass of the rubber component is less than 15 parts by mass, the flame retardancy is reduced, and when it exceeds 60 parts by mass, the moldability is reduced. Therefore, in the composition of the present embodiment, the aluminum hydroxide content is 15 to 60 parts by mass with respect to 100 parts by mass of the rubber component.

  The particle size of aluminum hydroxide is not particularly limited, but is preferably 1 to 50 μm from the viewpoint of dispersibility.

[Boric acid: 20 to 70 parts by mass]
Boric acid acts as a shape retention agent after thermal expansion. The boric acid content can be appropriately set depending on the amount of expansive graphite used, but when it is less than 20 parts by mass per 100 parts by mass of the rubber component, the shape retention after thermal expansion is lowered. Moreover, when content of boric acid exceeds 70 mass parts per 100 mass parts of rubber components, the hardness of a composition will become high and flexibility will fall. Therefore, content of boric acid shall be 20-70 mass parts with respect to 100 mass of rubber components.

  As boric acid to be blended in the composition of the present embodiment, those obtained by a known production method can be used. Either orthoboric acid or metaboric acid may be used, but orthoboric acid is usually used. Further, this boric acid is usually used in a powder state. In this case, the particle size of the powder is not particularly limited, but a powder having a relatively small particle size, specifically, about 100 μm or less, preferably about 20 μm or less is preferable.

[Inorganic filler (excluding aluminum hydroxide and boric acid): 20 to 60 parts by mass]
Inorganic fillers other than aluminum hydroxide and boric acid are added to maintain the expanded shape as an aggregate of the thermally expanded body after combustion. However, when the content of the inorganic filler is less than 20 parts by mass with respect to 100 parts by mass of the rubber component, the strength of the foam after thermal expansion is insufficient, resulting in insufficient heat resistance and flame retardancy. If the amount exceeds 60 parts by mass, the workability decreases. Therefore, the content of the inorganic filler other than aluminum hydroxide and boric acid is 20 to 60 parts by mass per 100 parts by mass of the rubber component.

  The kind is not specifically limited, A well-known inorganic filler can be employ | adopted. Examples include alumina, zinc oxide, titanium oxide, metal oxides such as calcium oxide and magnesium oxide, hydrous minerals such as calcium hydroxide, magnesium hydroxide and hydrotalcite, basic magnesium carbonate, magnesium carbonate, calcium carbonate, Metal carbonates such as zinc carbonate and barium carbonate, calcium salts such as calcium sulfate and calcium silicate, silica, diatomaceous earth, barium sulfate, talc, mica, clay, bentonite, activated clay, sepiolite, glass fiber, glass beads, graphite, Examples thereof include carbon fiber, carbon fiber, and various metal powders.

  In addition, the inorganic filler mentioned above may be used independently, or may use 2 or more types together. Of these inorganic fillers, calcium carbonate is particularly preferable. Furthermore, the particle size is desirably 1 to 50 μm from the viewpoint of dispersibility in the rubber component.

[Vulcanizing agent and vulcanization accelerator: 0.02 to 5 parts by mass for each]
Vulcanization and a vulcanization accelerator are blended in order to impart natural vulcanizability to the composition of the present embodiment and the molded body thereof. Here, “natural vulcanization” refers to vulcanization that occurs in the environment of use, not by heat generated by a kneading process or by artificial heating but by radiant heat of sunlight.

  That is, the composition of the present embodiment is not vulcanized at the stage of molding into a joint material or the like, but the molded body remains unvulcanized, even though it contains a vulcanizing agent and a vulcanization accelerator. Manufactured. Then, the molded body is attached to the adherend utilizing its excellent flexibility and adhesiveness, and is fixed to the adherend surface by natural vulcanization in an environment.

  In order to optimize the characteristics based on the natural vulcanizability, the content ratio of the vulcanizing agent and the vulcanization accelerator is set in the range of 0.02 to 5 parts by mass with respect to 100 parts by mass of the rubber component. When the content of the vulcanizing agent or vulcanization accelerator is less than 0.02 parts by mass with respect to 100 parts by mass of the rubber component, the natural vulcanization property is not exhibited or the progress of natural vulcanization is too slow. As a result, the fixing speed of the molded body such as the joint material becomes insufficient. Further, when the vulcanizing agent and the vulcanization accelerator are used in an amount exceeding 5 parts by mass per 100 parts by mass of the rubber component, the natural vulcanization rate is increased and the stability during storage is lowered.

  The kind of vulcanizing agent mix | blended with the composition of this embodiment is not specifically limited, A well-known vulcanizing agent is employable. Examples include sulfur compounds such as sulfur and polysulfides, oxime compounds such as p-quinone dioxime and p-p-dibenzoylquinone oxime, t-butyl hydroperoxide, acetylacetone peroxide, cumene hydroperoxide, and the like. An organic peroxide type compound is mentioned. Among these, a particularly preferable vulcanizing agent is a sulfur compound. Further, for example, two or more vulcanizing agents can be used in combination, such as a combination of a sulfur compound and other vulcanizing agents.

  On the other hand, the type of vulcanization accelerator is not particularly limited, and a known vulcanization accelerator can be employed. Examples thereof include thiuram compounds such as tetramethyl thiuram disulfide, tetrabutyl thiuram disulfide, tetramethyl thiuram monosulfide, dipentamethylene thiuram tetrasulfide, thiazole compounds such as 2-mercaptobenzothiazole and dibenzothiazole disulfide, dimethyldithiocarbamine. Aldehyde amine compounds such as zinc oxide, zinc diethyldithiocarbamate, n-butyraldehydeaniline, sulfenamide compounds such as N-cyclohexyl-2-benzothiazylsulfenamide, diortholyl guanidine, diorthonitrile guanidine, etc. Guanidine compounds, diethylthiourea, thiourea compounds such as topylmethylthiourea, zinc white, and the like.

  Among these, particularly preferred vulcanization accelerators are dithiocarbamate compounds such as zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, and zinc di-n-butyldithiocarbamate. These compounds may be used alone or in combination of two or more.

[Other ingredients]
In the composition of the present embodiment, a plasticizer, a softening agent, an anti-aging agent, a processing aid, a lubricant and the like can be used in combination as long as the effect is not inhibited. Examples of softeners and plasticizers that are effective in adjusting processability include paraffinic and naphthenic process oils, liquid paraffin and other paraffins, waxes, phthalic acid, adipic acid, sebacic acid and phosphorus. Examples thereof include ester plasticizers such as acid series, stearic acid and esters thereof.

[Production method]
Next, the manufacturing method of the thermally expansible resin composition of this embodiment is demonstrated. The composition of the present embodiment can be obtained by kneading the aforementioned components in an unvulcanized state. The kneading method is not particularly limited, but it is desirable to knead each component at 60 to 110 ° C. Thereby, since the vulcanization reaction during kneading can be controlled, the composition after kneading can be brought into a state in which it can be naturally vulcanized.

  In addition, when the kneading process is performed at a temperature exceeding 110 ° C., the vulcanization reaction proceeds during the kneading, and the flexibility of the obtained composition is reduced, or the appropriate natural vulcanizability is obtained. It may not be demonstrated. When the kneading temperature is less than 60 ° C., the melting temperature of the styrenic thermoplastic elastomer has not been reached, so that the unmelted styrenic elastomer is dispersed in the composition, resulting in insufficient strength. In addition, appearance defects may occur in the molded product.

  More specifically, the composition of the present embodiment is kneaded for 5 minutes at a rotation speed of 40 rotations / minute at 85 ° C. using, for example, a two-rotor kneading apparatus, and then the vulcanizing agent and vulcanization accelerator are added. It is obtained by adding and kneading at 100 ° C. for 5 minutes at the above rotational speed. The two-rotor kneading apparatus used in this kneading treatment step is not particularly limited, and a known apparatus can be used. Specifically, any apparatus capable of kneading at a rotational speed of 40 rotations / minute at 85 ° C. to 100 ° C. may be used. For example, a Banbury mixer and a kneader mixer can be used.

  As described above in detail, the thermally expandable resin composition of the present embodiment is a combination of a specific inorganic filler and a thermally expandable graphite having a specific expansion start temperature. In addition, a molded article (thermally expandable fireproofing material such as a joint material) having shape retention after expansion and exhibiting excellent fire resistance is obtained. In addition, since it does not contain components that generate harmful gases such as halogen compounds, it is excellent in safety during combustion.

  Furthermore, since the composition of this embodiment combines a rubber component with a specific composition including butyl rubber, a vulcanizing agent and a vulcanization accelerator, when the composition has adhesive properties, the molded product is pasted. At the construction stage to be applied, it has adhesiveness, and vulcanization progresses with time, and it is possible to realize a pasting performance that finally becomes an adhesive state. On the other hand, when the formulation is low in tackiness, the molded product can be attached with an adhesive or a pin along the shape of the adherend, and the material strength increases with time, so it functions as a strong fireproof material To do.

(Second Embodiment)
Next, a thermally expandable joint material for fire protection (hereinafter also simply referred to as joint material) according to a second embodiment of the present invention will be described. The joint material of the present embodiment is obtained by molding the above-described fire-expandable thermally expandable resin composition into a predetermined shape without being vulcanized, and the degree of vulcanization is 10% or less. If the degree of vulcanization after molding exceeds 10%, the subsequent vulcanization rate becomes faster, and the storage stability of the joint material decreases.

  The joint material of the present embodiment is more preferably vulcanized to 70% or more when held for 120 days in a 50 ° C. atmosphere. Thereby, even after a lapse of a certain period, the joint material can have sufficient adhesiveness and strength. Of course, this self-vulcanization rate can be evaluated at different temperatures and periods.

  Furthermore, it is preferable that the joint material of this embodiment starts thermal expansion under a temperature condition of 140 to 160 ° C. Thereby, since expansion starts at a lower temperature than before, it becomes possible to block the gap and block the smoke and heat even in a situation where the environmental temperature at the initial stage of the fire does not reach 200 ° C.

  On the other hand, the shape of the joint material of the present embodiment is not particularly limited, and can be appropriately designed according to the shape of the adherend. For example, if it is formed into a tape shape, it can be affixed to a door frame or the like, and if it is formed into a sheet shape, the surface of the door can be covered. Also, the molding method is not particularly limited, and various molding methods such as conventional press molding, extrusion molding and calendar molding can be freely employed.

  And the joint material of this embodiment is attached to adherends, such as a door, a door frame part, and an air vent part, without going through a vulcanization process, making use of its excellent flexibility and adhesiveness, And fixed to the adherend surface by natural vulcanization.

  As described above in detail, the thermally expandable joint material for fire protection according to the present embodiment includes a rubber component, thermally expandable graphite, boric acid, aluminum hydroxide, other inorganic filler components, a vulcanizing agent, and a vulcanizing agent. Since the unvulcanized composition containing the accelerator in the specific ratio described above is used and molded without being vulcanized, it has good flexibility and adhesiveness.

  In addition, this jointing material has a natural vulcanization property and exhibits an appropriate vulcanization speed and sufficient strength after vulcanization, so that it maintains a strong mounting state over time when mounted on a building member or the like. be able to. In addition, since thermal expansion starts at a lower temperature than before, the ambient temperature after the fire has not reached 200 ° C, the gaps such as doors, shutters and vents are closed to block the smoke and heat and spread the fire. Can be prevented. Furthermore, since the joint material of this embodiment does not contain a halogen compound, no harmful gas is generated even if it is burned.

  Hereinafter, the effects of the present invention will be specifically described with reference to Examples and Comparative Examples of the present invention. In addition, these Examples do not limit this invention.

In this example, a joint material is prepared using the thermally expandable compositions of Examples 1 and 2 within the scope of the present invention and the thermally expandable compositions of Comparative Examples 1 to 8 that deviate from the scope of the present invention. Its characteristics were evaluated.

Each compounding component used in this example is as follows.
(1) Rubber: Butyl rubber ("Butyl 268" manufactured by JSR)
Ethylene-propylene-diene rubber ("EP-51" manufactured by JSR)
SBS (JSR Shell “Clayton D1101”)
(2) Expandable graphite A: expansion start temperature 130 to 150 ° C. (“ACT671” manufactured by BAC)
Expandable graphite B: expansion start temperature 200 to 230 ° C. (“SS-3” manufactured by Air Water)
(3) Aluminum hydroxide (“C-301R” manufactured by Sumitomo Chemical Co., Ltd.)
(4) Boric acid (BOR)
(5) Inorganic filler: Calcium carbonate (Bihoku Flour & Chemical Co., Ltd. “Whiteon SB”)
(6) Vulcanizing agent: Powdered sulfur (made by Hosoi Chemical Co., Ltd.)
(7) Vulcanization accelerator A: Zinc dimethyldithiocarbamate (“Noxeller PZ” manufactured by Ouchi Shinsei Chemical Co., Ltd.)
Vulcanization accelerator B: zinc di-n-butyldithiocarbamate (“Noxeller BZ” manufactured by Ouchi Shinsei Chemical Co., Ltd.)
(8) Softener: Naphthenic oil (“NP-24” manufactured by Idemitsu Kosan Co., Ltd.)

  In addition, a pressure kneader (mixed volume 3 liters / DS3-10MWB-S type) was used for kneading each composition described above, and the kneading temperatures in Examples 1 and 2 and Comparative Examples 1 to 8 were as follows. The mixture was kneaded for 5 minutes at 100 ° C and 130 ° C in Comparative Example 9 at a rotation speed of 40 rotations / minute. Furthermore, the molding of the joint material was performed by using a 60 m / m single screw extruder (/ 60K-16D-HB, manufactured by Mitsuba Seisakusho Co., Ltd.), and the cylinder temperature was 90 ° C. in Examples 1 and 2 and Comparative Examples 1 to 8. In Comparative Example 9, extrusion molding was performed at 130 ° C.

  On the other hand, evaluation items and evaluation methods for joint materials of Examples and Comparative Examples are shown below. For evaluation, a test piece having a thickness of 2 mm, a width of 20 mm, and a length of 50 mm was cut out from each joint material processed into a tape shape and used.

<Thermal expansion start temperature>
The test piece cut out from each joint material of Examples and Comparative Examples was placed in a gear oven where the ambient temperature could be continuously changed, held at each temperature for 0.5 hour, and then removed and the temperature at which the volume change occurred. Was measured.

<Thermal expansion ratio>
The expansion rate after the test piece cut out from each joint material of an Example and a comparative example was left for 0.5 hour in the atmosphere hold | maintained at 300 degreeC was measured.

<Processability>
A 60m / m single-screw extruder ("60K-16D-HB" manufactured by Mitsuba Manufacturing Co., Ltd.) was used to extrude a tape-shaped fireproof joint material having a thickness of 2mm and a width of 20mm. Or those with uneven discharge performance were evaluated as “impossible”.

<Shape retention>
The test piece after the above-described measurement of the thermal expansion ratio was evaluated by visual observation and finger touch. At that time, those that did not lose shape and did not collapse even when touched with a finger were evaluated as “good”, and those that immediately collapsed by touch or that had already collapsed were determined as “impossible”.

<Degree of vulcanization>
Torque was measured with a curast meter type III (manufactured by JSR Trading Co., Ltd.) by the method prescribed in JIS K6300, and the degree of vulcanization was calculated by the following formula 1. In the following formula 1, MX is the torque value of the material after a certain period, ML is the minimum torque value in the measurement curve, and MM is the maximum torque value in the measurement curve.

<Tensile strength>
The press-molded sheet was punched out into a No. 3 dumbbell from a 5 mm thick sheet and pulled at a speed of 500 mm / min to obtain the maximum stress.

<T-type peel adhesion strength>
The adhesion strength was measured in accordance with the peel adhesion strength test method specified in JIS K6854. Specifically, the T-type peel adhesion strength was measured for each of a SUS plate having a thickness of 2 mm, a length of 25 mm, and a width of 150 mm with a test piece sandwiched between and immediately after application and after being left in a 50 ° C. oven for 120 days. It was measured. At that time, the peeling speed was 50 mm / min.

  The above results are summarized in Table 1 below.

  As shown in Table 1 above, the joint material of Comparative Example 1 using the thermally expandable graphite having an expansion start temperature exceeding 200 ° C. has a high expansion start temperature and is expected to have fireproof performance in an environment below 200 ° C. It was not. On the other hand, since the joint material of Comparative Examples 2 and 3 does not contain a vulcanizing agent and a vulcanization accelerator, the joint material strength remains low in the non-adhesive type and the adhesive strength remains low in the adhesive type. There was a high possibility of breakage or peeling due to the change.

  Moreover, since the joint material of Comparative Example 4 has a heat-expandable graphite content of 20 parts by mass, a sufficient thermal expansion ratio could not be obtained. The joint material of Comparative Example 5 was inferior in workability because the content of aluminum hydroxide exceeded 60 parts by mass. Since the joint material of Comparative Example 6 had a boric acid content of less than 20 parts by mass, the shape retention was poor.

Furthermore, since the joint material of Comparative Example 7 had a boric acid content of more than 70 parts by mass, the shape retention was excellent, but the expansion coefficient was suppressed, and the flexibility was lowered and the tensile strength was lowered. . The joint material of Comparative Example 8 had low processability because the content of the inorganic filler exceeded 60 parts by mass .

  On the other hand, the joint materials of Examples 1 and 2 were superior to the joint materials of Comparative Examples 1 to 9 in all items.

Claims (6)

Butyl rubber: 25-80% by mass, Rubber co -vulcanizable with the butyl rubber: 5-60% by mass and Styrenic thermoplastic elastomer: 15-70% by mass
Thermal expansion graphite having an expansion start temperature of 130 to 150 ° C .: 20 to 75 parts by mass;
Aluminum hydroxide as a temperature rise inhibitor : 15-60 parts by mass,
Boric acid: 20-70 parts by mass as a shape retention agent after thermal expansion ;
No machine filler (excluding aluminum hydroxide and boric acid) and 20 to 60 parts by weight,
Vulcanizing agent and vulcanization accelerator: 0.02 to 5 parts by mass,
Is obtained by molding and processing a thermally expandable resin composition for fire protection without vulcanization,
A heat-expandable joint material for fire protection, wherein the heat-expandable graphite exists in an unexpanded state, and the vulcanization degree of the rubber component is 10% or less, and is naturally vulcanized in a use environment. The fire-proof according to claim 1, wherein the rubber vulcanizable with the butyl rubber is at least one rubber selected from the group consisting of natural rubber, ethylene-propylene-diene rubber and styrene-butadiene rubber. Thermally expandable joint material. The thermally expandable joint material for fire protection according to claim 1 or 2, wherein the inorganic filler contains at least calcium carbonate. When allowed to spontaneously vulcanized held for 120 days at a temperature of 50 ° C., according to any one of claims 1 to 3 vulcanization degree is characterized by comprising 70% or more of the rubber component Thermally expandable joint material for fire protection. 140 to 160 ° C. Fire heat expandable joint compound according to any one of claims 1 to 4, characterized in that to start the expansion at a temperature of. The heat-expandable joint material for fire prevention according to any one of claims 1 to 5 , wherein the heat-expandable joint material is applied to a door, a door frame, a gap between the door and a wall, or a vent.