KR101999047B1 - Combined extrusion gasket and Method for manufacturing the same - Google Patents

Abstract

Provided in the present invention are a combined extrusion gasket and a manufacturing method thereof, the gasket comprising: a first gasket unit; and a second gasket unit. Therefore, hardening properties can be prevented from being reduced while flame retardancy is improved. In addition, harmful gas, which is produced when the gasket is melted by a fire, is prevented. Furthermore, a course through which the fire proceeds is prevented from being opened, and a condensation phenomenon can also be prevented.

Description

[0001] Combined extrusion gasket and method for manufacturing same [0002]

The present invention relates to a composite extrusion gasket and a method of manufacturing the same, and more particularly, to a composite extrusion gasket and a method of manufacturing the same, which comprises a first gasket portion made of a first silicone composition having a relatively low hardness and emphasizing airtightness and heat insulation, and a second silicone composition The second gasket portion can prevent the phenomenon of opening the path of the toxic gas and the flame generated when the gasket is burned in the fire and can prevent the reduction in the curability caused by the incombustible material, The present invention relates to a composite extrusion gasket capable of extrusion molding without use and capable of preventing condensation by improving airtightness and heat insulating property, and a method of manufacturing the same.

Generally, the gasket is made of elastic material such as rubber and is used to increase the easiness of work when fixing the glass to the chassis frame. In addition, gaskets used in conventional buildings are usually used for windows and door frames of construction sites and are mainly used for leakage and soundproofing, and are made of synthetic rubber or vinyl chloride (Polyvinyl Chloride).

If a fire occurs and the building is ignited, the gasket is also ignited. If the gasket is made of synthetic rubber or vinyl chloride as above, halogen-based toxic gas is generated. Such gas is harmful to the human body, Inhalation may cause serious injury to the body.

In addition, one of the reasons that the fire is transferred to the neighboring building when a fire occurs is because the path is opened so that the fire can move. When the gasket fails to withstand the heat caused by the fire, a gap is created thereby, The glass or door is broken due to the twist of the chassis frame or the door frame frame, and the course of the fire is opened. Thus, fire may be transmitted from the ignition point to the surrounding building, resulting in secondary damage.

In addition, when the chassis frame is installed on the outer wall, a gap generated due to the disappearance of such a gasket is a passage for introducing air (oxygen) into the inside of a building having a flame from the outside, As a result of the spreading of the flames, the flames can block the escape route, which can make life and property damage more serious.

Further, the gasket is manufactured mainly using silicone rubber, and the conventional gasket has a low tear strength and tends to be torn easily even to small external factors. Further, when the liquid silicone rubber is used as the main material of the gasket, since it is difficult to extrude due to poor viscosity, it is difficult to extrude the liquid silicone rubber, so that it must be manufactured using the mold frame. There is an increasing problem.

On the other hand, when the gasket is manufactured to have a too hard hardness, airtightness and heat insulation may be lowered when applied to a door frame frame, or a gap may be generated between the door frame frame and the door, resulting in poor installation stability, There may be a problem that a condensation phenomenon occurs.

Korean Patent Publication No. 10-2015-0007122 Japanese Patent Application Laid-Open No. 2000-54526

It is an object of the present invention to improve the fire resistance and fire resistance and to withstand the heat caused by the fire when a fire occurs so as to prevent the chassis frame or the frame frame from being twisted due to the disappearance of the toxic gas and gasket, A composite extrusion gasket capable of preventing escape of air from the outside to prevent the spread of flames and easily preventing an escape route and improving airtightness and heat insulation to prevent condensation, and a manufacturing method thereof .

It is also an object of the present invention to provide a composite extrusion gasket which is easy to extrusion-molded without using a mold and can improve tear strength and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a gasket comprising: a first gasket portion formed of a first silicone composition, the first gasket portion having a hollow having a pair of stepped portions formed on opposite sides of the inner surface thereof; And a second gasket portion formed of a second silicone composition, the second gasket portion being integrated on one surface of the first gasket portion in the first direction and having a plurality of protrusions formed on both surfaces in a second direction perpendicular to the first direction; Wherein the first silicone composition comprises 10 to 40 parts by weight of flame retardant silicone, 10 to 30 parts by weight of a flame retardant filler, 40 to 70 parts by weight of fired alumina, 3 to 10 parts by weight of a plasticizer, Wherein the second silicone composition comprises a second silicone rubber and a solid flame retardant silicone rubber comprising a first silicone rubber having a relatively higher softness than the second silicone rubber, heat-resistant agent, a flame retardant, aluminum hydroxide (Al (OH) ₃₎ and the expansion comprises a silicone rubber dough, apchulga ryuje and a curing agent containing graphite, wherein the expanded graphite is 40 to 60 parts by weight per 100 parts by weight of the silicone rubber kneading Wherein the curing agent is selected from the group consisting of a first curing agent comprising bis (2,4-dichlorobenzoyl) peroxide and a silicone oil, and a second curing agent including silica (silica), tetramethyl tetravinyl cyclotetrasiloxane , Octamethylcyclotetrasiloxane, a curing retarder, and a platinum catalyst.

According to another aspect of the present invention, there is provided a gasket comprising: a first gasket portion made of a second silicone composition, the first gasket portion having a cavity with a pair of stepped portions formed on opposite sides of the inner surface, And a second gasket portion formed of a first silicone composition, the second gasket portion being integrated on one surface of the first gasket portion in a first direction and having a plurality of protrusions formed on both surfaces in a second direction perpendicular to the first direction; Wherein the first silicone composition comprises 10 to 40 parts by weight of flame retardant silicone, 10 to 30 parts by weight of a flame retardant filler, 40 to 70 parts by weight of fired alumina, 3 to 10 parts by weight of a plasticizer, Wherein the second silicone composition comprises a second silicone rubber and a solid flame retardant silicone rubber comprising a first silicone rubber having a relatively higher softness than the second silicone rubber, heat-resistant agent, a flame retardant, aluminum hydroxide (Al (OH) ₃₎ and the expansion comprises a silicone rubber dough, apchulga ryuje and a curing agent containing graphite, wherein the expanded graphite is 40 to 60 parts by weight per 100 parts by weight of the silicone rubber kneading Wherein the curing agent is selected from the group consisting of a first curing agent comprising bis (2,4-dichlorobenzoyl) peroxide and a silicone oil, and a second curing agent including silica (silica), tetramethyl tetravinyl cyclotetrasiloxane , Octamethylcyclotetrasiloxane, a curing retarder, and a second curing agent comprising a platinum catalyst.

According to a preferred feature of the present invention, the first silicone composition comprises at least one of polyalkylalkenyl siloxane, silica and silicon dioxide, and titanium oxide, Wherein the flame retardant filler comprises quartz, dimethyl siloxane, dimethylvinyl-terminated and titanium dioxide, wherein the plasticizer is dimethyl siloxane, Hydroxyl-terminated, dimethylcyclosiloxanes, methylcyclopentasiloxane and octamethylcycloterasiloxane, wherein the heat-resistant agent is selected from the group consisting of ceric hydroxide, Dimethyl siloxane, hydroxyl-terminated, octamethyl cyclotetrasiloxane, and the like. cycloterasiloxane, cerium hydrate impurities, methylcyclopentasiloxane, water, and dimethylcyclosiloxanes.

According to a preferred feature of the present invention, the second silicone composition is characterized in that the silicone rubber dough comprises 0.001 to 0.04 parts by weight of the plasticizer, 0.5 to 1.5 parts by weight of the heat resistant agent, 100 parts by weight of the flame retardant 1.5 to 4.5 parts by weight of the aluminum hydroxide and 10 to 100 parts by weight of the aluminum hydroxide, wherein the second silicone composition comprises, based on 100 parts by weight of the flame-retardant silicone rubber, 5 to 7 parts by weight of the extruded product, 5 to 10 parts by weight of the first curing agent And 5 to 10 parts by weight of the second curing agent.

According to a preferred aspect of the present invention, the second silicone composition may have a weight ratio of the first curing agent and the second curing agent of 0.9: 1 to 1: 0.9, and the weight ratio of the second silicone rubber and the first silicone rubber The weight ratio may be from 0.9: 1 to 1: 0.9.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a solid flame-retardant silicone rubber including a first silicone rubber having a relatively higher softness than a second silicone rubber; Preparing a silicone rubber dough by mixing a plasticizer, a heat resistant agent, a flame retardant, aluminum hydroxide, and expanded graphite in the solid flame-retardant silicone rubber; Mixing the silicone rubber dough with an extruder and a curing agent, and then compounding expanded expanded graphite to form a second sheet of a second silicone composition; A first silicone containing 10 to 40 parts by weight of flame-retardant silicone, 10 to 30 parts by weight of a flame-retardant filler, 40 to 70 parts by weight of fired alumina, 3 to 10 parts by weight of a plasticizer, and 1 to 5 parts by weight of a heat- Forming a first sheet of a composition; The first sheet is processed into a first gasket portion having a concave portion on its outer surface with a hollow having a pair of stepped portions formed on the inner surface thereof facing each other using an extruder, To a second gasket portion in which a plurality of projections are formed, respectively; And integrating a first gasket portion in a direction perpendicular to both sides of the second gasket portion; And 40 to 60 parts by weight based on 100 parts by weight of the silicone rubber dough, wherein the curing agent is bis (2,4-dichlorobenzoyl) peroxide and silicone oil, And a second curing agent comprising silica, silica, tetramethyl tetravinyl cyclotetrasiloxane, octamethylcyclotetrasiloxane, a curing retarder, and a platinum catalyst.

According to a preferred aspect of the present invention, the step of machining the first and second gasket portions comprises: a first vulcanizing step performed at 600 to 700 ° C; A secondary vulcanizing step carried out at 210 to 290 占 폚 and carried out in a horizontal rail having a length of 7 to 8 m; And a tertiary vulcanization step performed at 180 to 220 캜 and performed in an oven for 3.5 to 4.5 hours; And the first and second gasket portions may be a double bond hardening structure.

The composite extrusion gasket according to an embodiment of the present invention is characterized in that the second gasket portion includes expanded graphite to improve the fire resistance and fire resistance of the gasket and the expanded graphite plays a role of a filler preventing the crack propagation, have. In addition, since the second gasket portion contains a certain amount of the second curing agent containing platinum as a curing agent, there is an effect that it is possible to prevent decrease in curing due to expanded graphite that occurs during the manufacturing process. In addition, since the first gasket portion does not contain expanded graphite, the airtightness and the heat insulating property are improved, thereby improving the installation stability between the glass and the chassis frame or preventing a gap between the door frame and the door frame frame, There is an effect that it can be prevented.

In addition, the composite extrusion gasket according to an embodiment of the present invention is resistant to fire or deformation due to flames when a fire occurs, so that the occurrence of toxic gas generated when a conventional gasket is burned is suppressed, It is possible to prevent the frame or the frame frame from being twisted and to prevent the air from flowing into the inside of the building from the outside due to the occurrence of a gap due to the disappearance of the gasket, It has the effect of reducing property damage.

Further, since the second silicone composition contains as its main component a second silicone rubber having excellent heat resistance and a solid silicone rubber having a consistency higher than that of the second silicone rubber, Since the gasket can be manufactured by extrusion molding, the moldability can be improved and the manufacturing cost and time can be reduced.

1 is a perspective view schematically showing a gasket according to an embodiment of the present invention.
2 is a sectional view taken along the line I-I 'in Fig.
3 is a perspective view schematically showing a gasket according to another embodiment of the present invention.
4 is a sectional view taken along line II-II 'of FIG.

The embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the following embodiments. Further, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art.

However, the present invention is not limited to this, and can be applied to gaskets for fixing glass and chassis frames, gaskets for medical and food applications, and the like.

Referring to FIGS. 1 and 2, the gasket 100 of the present embodiment includes a first gasket 120 and a second gasket portion 120 which is double-cured and integrated with the first gasket 120 in the Z- 110). 1, the Y direction represents the longitudinal direction of the first and second gaskets 120,

The first gasket part 120 is a part that protrudes to be exposed to the outside when installed on the door frame frame, and closes the door when the door is closed, thereby blocking the gap between the door frame and the door. In this embodiment, The first body 121 is made of a first silicone composition having a cavity inside the first body 121 to prevent foreign matter from entering the room.

The first gasket 120 is formed by extrusion molding and the cross section of the first body 121 and the shape of the hollow 122 may be substantially circular. The shape of the cross section of the first body 121 is not limited thereto.

The hollow 122 of the first gasket 120 serves to contract the first body 121 of the first gasket 120 when the door is closed, A pair of stepped portions 121b are formed at two portions of the surface facing each other in the X direction. Therefore, when the door is closed, the upper portion of the first body 121 in the Z direction is supported while being hung from the step 121b with respect to the first gasket 120, It is possible to prevent the door from being closed hard.

The first gasket part 120 is free from changes in shape due to the external pressure due to the characteristics of the hollow part 122 and the first silicone composition and provides a superior restoring force. When the outer surface of the first body 121 is installed to protrude outwardly from the door frame frame when the door 120 is closed, it is possible to effectively prevent foreign matter from flowing through the gap between the door frame and the door frame frame.

Also, since the first gasket 120 improves the airtightness and the heat insulating property due to the characteristics of the first silicone composition, the first gasket 120 can prevent the condensation from occurring. At this time, a concave / convex portion 121a is formed on the outer surface (upper surface in the Z direction) of the first gasket portion 120 to improve adhesion and airtightness with the door when the door is closed, The effect of preventing development can be further improved.

The second gasket portion 110 is a portion which is embedded in the frame of the door frame and which emphasizes the fire resistance. The second gasket portion 110 is formed by extrusion molding. The second gasket portion 110 is formed by pressing the first gasket portion 120 And is made of a second silicone composition which will be described later, which is harder than the first silicone rubber.

The second gasket 110 has a hollow 112 inside the second body 111 and is fixed to the door frame on both sides in the X direction perpendicular to the Z direction integrated with the first gasket 120 A plurality of coupling protrusions 113 may be respectively formed in order to increase the tight contact force and the airtightness so as to be more firmly fixed.

The second silicone composition applied to the second body 111 of the second gasket portion 110 of the present embodiment includes a silicone rubber dough, an extrusion-flowable agent and a curing agent.

Wherein the silicone rubber paste comprises a solid flame retardant silicone rubber, a plasticizer, a heat resisting agent, a flame retardant, aluminum hydroxide (Al (OH) ₃ ), and a second silicone rubber including a second silicone rubber and a first silicone rubber having a higher concentration than the second silicone rubber And expanded graphite.

At this time, the first silicone rubber can not be used in the evaluation criteria of UL (Underwriter Laboratory) 94 flame retardancy and can be extinguished within 30 seconds, and V-2 grade containing wet silica can be used. The first silicone rubber may play a role in mixing the components of the silicone rubber dough.

Also, it is preferable that the second silicone rubber is subjected to UL (Underwriter Laboratory) 94 flame retardancy evaluation criterion and C.I. is not allowed and is extinguished within 30 seconds, and V-1 grade containing dry silica is used. The second silicone rubber has a relatively higher flame retardancy than the first silicone rubber. Here, C.I. is an abbreviation of Cotton Ignition, which means that the burning away from the burned specimen is ignited to a cotton lying about 30 cm below the burned specimen.

The silicone rubber paste may contain 0.001 to 0.04 parts by weight of the plasticizer, 0.5 to 1.5 parts by weight of the heat-resistant agent, 1.5 to 4.5 parts by weight of the flame retardant, 10 to 100 parts by weight of the aluminum hydroxide, And 40 to 60 parts by weight of the expanded graphite.

The second silicone composition may further comprise 5 to 7 parts by weight of the extrusion chargeable agent and 10 to 20 parts by weight of the curing agent, based on 100 parts by weight of the silicone rubber.

Wherein the curing agent is selected from the group consisting of a first curing agent comprising bis (2,4-dichlorobenzoyl) peroxide and a silicone oil, and a second curing agent comprising silica, tetramethyl tetravinyl cyclotetrasiloxane, octamethylcyclotetrasiloxane, And a hardening agent.

The weight ratio of the first curing agent to the second curing agent may be 0.9: 1 to 1: 0.9, and the weight ratio of the first silicone rubber and the second silicone rubber may be 0.9: 1 to 1: 0.9. That is, 5 to 10 parts by weight of the first curing agent and 5 to 10 parts by weight of the second curing agent may be mixed with 100 parts by weight of the flame-retardant silicone rubber.

The first silicone composition to be applied to the first gasket portion 120 of the present embodiment comprises 10 to 40 parts by weight of flame-retardant silicone, 10 to 30 parts by weight of a flame-retardant filler, 40 to 70 parts by weight of fired alumina, 3 To 10 parts by weight of a plasticizer, and 1 to 5 parts by weight of a heat resistant agent.

Here, the flame-retardant silicone may be the same as the solid flame-retardant silicone rubber of the second silicone composition. This first silicone composition does not include expanded graphite so that the first gasket portion 120 has soft hardness compared to the second gasket portion 110 so that the fire resistance is partially degraded but the airtightness and heat insulation are relatively improved .

At this time, the first silicone composition may include at least one of polyalkylalkenylsiloxane, silica and silicon dioxide, and titanium oxide. The first silicone composition is not easily burned because the content of hydrocarbons in the molecular structure is less than that of a general organic rubber, and no toxic gas is generated during combustion.

The flame-retardant filler may include quartz, dimethyl siloxane, dimethylvinyl-terminated, and titanium dioxide to improve flame retardancy. .

Further, the fired alumina may be alpha alumina. The alpha-alumina has a melting point of 600 DEG C and is supplied for heat blocking reinforcement.

The plasticizer is for improving the flexibility and processability of the first gasket portion 120. The plasticizer may be selected from the group consisting of dimethyl siloxane, hydroxyl-terminated, dimethylcyclosiloxanes, Methylcyclopentasiloxane and octamethylcycloterasiloxane. The term " methylcyclopentasiloxane "

The heat-resistant agent may be at least one selected from the group consisting of ceric hydroxide, dimethyl siloxane, hydroxyl-terminated, octamethylcycloterasiloxane, cerium hydrate impurities, Methylcyclopentasiloxane, water, and dimethylcyclosiloxanes. ≪ Desc / Clms Page number 7 >

In the composite extrusion gasket 100 constructed as described above, the fire resistance of the second gasket portion 110 is enhanced, and the first gasket portion 120 is improved in airtightness and heat insulation. Thus, the gasket is not easily lost by heat It is possible to prevent the occurrence of toxic gases and flames from occurring due to the ignition of existing gaskets as well as the occurrence of toxic gas, and it is possible to improve the installation stability of the doors installed on the frame and frame, Can be effectively prevented. In addition, it is possible not only to suppress the decrease in the curability caused by the incombustible material but also to perform extrusion molding without using a mold.

3 and 4, the first body 121 'of the first gasket 120' may be made of a second silicone composition and the second gasket 110 ' 'May be made of the first silicone composition to produce the composite extrusion gasket 100'. Reference numeral 121a 'designates a concave-convex portion, and 121b' designates a step.

Hereinafter, a method of manufacturing a composite extrusion gasket according to an embodiment of the present invention will be described in detail.

First, a second sheet of a second silicone composition is provided. To this end, a solid flame-retardant silicone rubber comprising a first silicone rubber and a second silicone rubber having a higher softness than the first silicone rubber is provided.

The solid flame-retardant silicone rubber may be formed by mixing at least two kinds of silicone rubbers. In this embodiment, the flame-retardant silicone rubber is formed by mixing the first and second silicone rubbers.

The second silicone rubber may be a commercially available silicone rubber, which is excellent in refractoriness, heat resistance, flame retardancy and fire resistance. In addition, the second silicone rubber can utilize a silicone rubber having strong heat resistance, good thermal stability, and high insulation properties.

The properties of the materials required to be used for such second silicone rubbers are those having a specific gravity of 1.08 to 1.10, a durometer measurement of 32 to 37 Durometer Shore A, a tensile strength of 8 to 11 MPa, an elongation at fracture of 740 To 910%, a tear strength of 24.0 to 31.0 kN / m, and a compression set ratio (22 hours, 177 ° C) of 31 to 41%.

The second silicone rubber may serve as a base component in the second silicone composition according to one embodiment of the present invention.

The first silicone rubber can use silicone rubber having a higher flake than the second silicone rubber. The term "softness" refers to the state of hardness of an object in the middle of a conductor and liquid, which means the degree of fluidity of the silicone rubber.

The properties of the material required to be used for such a first silicone rubber may be plasticity of 240 or more. The material that can be used for the first silicone rubber is a silicone rubber having a density of 1.1 to 1.2 g / cm 3, a hardness (JIS type A) of 48 to 50, a tensile strength of 9.1 to 9.5 MPa, an elongation ) Is 510 to 550%, and the tear strength is 20 to 25 N / mm.

In the case of the liquid silicone rubber, since the viscosity is low, extrusion can not be performed, and the shape of the gasket is limited because it is required to be manufactured in a desired shape by using a mold frame, which is disadvantageous in manufacturing process and cost.

However, the second silicone composition according to the present embodiment uses a second silicone rubber satisfying the above-mentioned characteristics as a base material, and a silicone rubber having a higher softness than the second silicone rubber as the first silicone rubber And a solid flame-retardant silicone rubber to be formed is used.

Therefore, the gasket can be easily formed by the extruding device, and the manufacturing process and cost can be reduced, and it becomes possible to more easily form the gasket of the desired shape.

In this case, the weight ratio of the second silicone rubber and the first silicone rubber may be 0.9: 1 to 1: 0.9 in order to maintain the refractory characteristics and the workability of the silicone composition at a desired level. If the weight ratio of the second silicone rubber and the first silicone rubber is out of the range of 0.9: 1 to 1: 0.9, there may arise a problem that the refractory characteristics are reduced or the processability of the composition is decreased.

For example, when the weight ratio of the second silicone rubber and the first silicone rubber is out of the range of 0.9: 1 to 1:09, the heat resistance is reduced. Thus, the fire resistance test C-2 of the Ministry of Land, It is not possible to satisfy the condition of 120 minutes fire resistance. In this embodiment, the weight ratio of the second silicone rubber and the first silicone rubber is set to 0.9: 1 to 1: 0.9, and the excellent shading property that satisfies the fire resistance characteristic of 120 minutes in the fire resistance test (C-2) Can be provided.

Next, a silicone rubber paste is prepared by mixing a plasticizer, a heat-resistant agent, a flame retardant, aluminum hydroxide, and expanded graphite into a solid flame-retardant silicone rubber.

The plasticizer improves the processability of the flame-retardant silicone rubber during the process of preparing the composition and imparts flexibility to the produced gasket.

Such a plasticizer may include polydimethylsiloxane or octamethyltetrasiloxane, and more preferably octamethyltetrasiloxane. The plasticizer may include, for example, polydimethylsiloxane or octamethyltetrasiloxane.

When the flame-retardant silicone rubber is contained in an amount of 100 parts by weight, the amount of the plasticizer may be 0.001 to 0.04 part by weight. If the content of the plasticizer is less than 0.001 parts by weight or more than 0.04 parts by weight, the processability of the flame-retardant silicone rubber may be greatly reduced or become too thin, so that it may be difficult to produce the silicone rubber dough in a sheet form suitable for extrusion molding.

The heat resisting agent imparts high heat-resistant properties to the gasket to prevent the gasket from easily burning or generating toxic gas. The heat resistant agent may be included in an amount of 0.5 to 1.5 parts by weight based on 100 parts by weight of the flame-retardant silicone rubber. If the heat resistant agent is less than 0.5 part by weight, the heat resistance is low, so that even if the flame is exposed to the flame at a low temperature for a certain period of time, the gasket may easily be ignited or deformed. If the heat resistant agent exceeds 1.5 parts by weight, the improvement in the fire resistance hardly changes. Therefore, the upper limit of the heat resistant agent is preferably 1.5 parts by weight for the purpose of reducing the production cost.

The flame retardant improves the flame retardancy of the gasket so that it does not burn well and prevents the gasket from easily burning or generating toxic gas when a fire occurs. The flame retardant of the present embodiment is not a halogen flame retardant used in organic rubber but a non-halogen flame retardant such as FR-1, FR-2 and FR-3 which are inorganic rubber flame retardants.

The flame retardant may be contained in an amount of 1.5 to 4.5 parts by weight based on 100 parts by weight of the flame-retardant silicone rubber. If the content of the flame retardant is less than 1.5 parts by weight, flame retardancy is low, so that the gasket may easily melt at a low temperature. If the amount of the flame retardant exceeds 4.5 parts by weight, the flame retardancy of the flame retardant does not substantially improve. Therefore, the upper limit of the flame retardant is preferably 4.5 parts by weight in order to reduce the production cost.

Since the aluminum hydroxide causes an endothermic reaction when a fire occurs, it functions to reduce the temperature rise and to suppress the movement of the combustion, and thus functions to improve the heat resistance of the gasket by assisting the function of the flame retardant. The structure of the aluminum hydroxide is a structure in which water molecules are mixed between silica and the water molecules are released from the gap of silica when heated and thus the aluminum hydroxide is a water- It is possible to block the contact of oxygen which is a cause of combustion and further improve the fire resistance of the gasket.

The aluminum hydroxide may be included in an amount of 10 to 100 parts by weight based on 100 parts by weight of the flame-retardant silicone rubber. At this time, if the amount of the magnesium hydroxide is less than 10 parts by weight, improvement in heat resistance may not be realized properly. If the amount of the flame retardant exceeds 100 parts by weight, physical properties such as tear strength, stretch and tensile may be drastically deteriorated. Since the heat resistance is not improved any more, the aluminum hydroxide The upper limit value is preferably 100 parts by weight.

On the other hand, if a gasket is manufactured using a solid silicone rubber, the tear strength of the second silicone rubber may be relatively low. As a result, the produced gasket is easily torn by an external impact, and the torn portion may be further damaged by a small force.

However, the silicone composition according to one embodiment of the present invention can increase the tear strength of a gasket produced by the expansion graphite serving as a filler of the solid flame-retardant silicone rubber by foaming or expansion characteristics.

The expanded graphite may be obtained through oxidation of natural or synthetic graphite, and the oxidizing agent used for the oxidation of graphite may be sulfuric acid or nitric acid. When the expanded graphite is heated at room temperature to about 800 ° C for a short period of time as in the case of a fire, the non-volatile change (based on the c-axis direction of the crystal) of the expanded graphite may be 100 ml / g or more.

In addition, the average particle size D ₅₀ of the expanded graphite may be several tens to several thousands of micrometers. If the average particle size of the expanded graphite is too small, the flame retarding effect is remarkably reduced. If the average particle size of the expanded graphite is too large, the physical properties of the produced gasket may be reduced. In the present embodiment, the preferred density of expanded graphite may be 0.4 to 2 g / cm < 3 >, but the present invention is not limited thereto.

Such expanding graphite has a characteristic that carbonized layer is formed by foaming when exposed to heat at a high temperature such as a fire accident, and the carbonized layer is made of porous graphite, which is a non-combustible material, and does not catch fire. That is, the silicone composition according to one embodiment of the present invention can greatly improve the fire resistance or the flame retardancy of the gasket due to the expanded graphite.

In the present embodiment, when 100 parts by weight of the silicone rubber is contained, 40 to 60 parts by weight of expanded graphite may be included. If the amount of expanded graphite is less than 40 parts by weight, the produced gasket may have insufficient fire resistance or flame retardancy. If the amount of expanded graphite exceeds 60 parts by weight, the workability of the silicone composition may decrease and the ductility of the produced gasket may decrease.

Therefore, in order to ensure the processability of the second silicone composition of the present embodiment and ensure ductility of the produced gasket, when the second silicone composition according to the present embodiment contains 100 parts by weight of the solid flame-retardant silicone rubber, Is contained in an amount of 40 to 60 parts by weight.

Next, the above-mentioned solid flame-retardant silicone rubber, plasticizer, heat-resistant agent, flame retardant, aluminum hydroxide and expanded graphite are kneaded and kneaded in a kneader to prepare a silicone rubber dough.

Next, the step of mixing the extruding agent and the curing agent into the silicone rubber dough in an open roller and forming the silicone rubber dough into a second sheet form of the second silicone composition is carried out.

At this time, the extruded flowability agent enhances elasticity and stability, and may be included in an amount of 5 to 7 parts by weight based on 100 parts by weight of the flame-retardant silicone rubber. If the extruder flow rate is less than 5 parts by weight, elasticity, stability and flame retardancy may be deteriorated. If the extruder flow rate exceeds 7 parts by weight, there may occur a problem in curing during the production of the gasket.

The curing agent is added to perform the curing process of the silicone rubber dough.

Silicone rubber generally performs curing by crosslinking a siloxane chain by addition reaction of a polysiloxane containing a vinyl group and a polysiloxane having Si-H bonds. At this time, the silicone rubber paste of the present embodiment may not be cured properly due to the curing agent generally used because of expanded graphite.

That is, since there is a problem that the silicon hydride (Si-H) is hardly adhered to the unsaturated carbon-carbon bond by a generally used hardening agent, the silicone composition of the present embodiment requires a method for improving the hardenability including the expanded graphite Do.

To this end, the second silicone composition according to the present embodiment may contain not only a first curing agent including bis (2,4-dichlorobenzoyl) peroxide and silicone oil but also silica, tetramethyl tetravinyl cyclotetrasiloxane, octamethylcyclotetrasiloxane, And a second curing agent comprising a curing retarder and a platinum catalyst.

The first curing agent plays a role in cross-linking the silicon hydrides of the solid flame-retardant silicone rubber which is the main component of the silicone rubber dough during the curing reaction.

The second silicone composition of the present embodiment contains expanded graphite. Since graphite has a strong hindrance to curing property, the first curing agent is used as a main curing agent. However, as described later, the second curing agent In addition, the curing can be performed well even in low heat, and the problem that the first curing agent is not completely cured by the expanded graphite can be solved.

Since the second curing agent of the present embodiment includes a platinum catalyst and a curing retardant, the silicone hydride (Si-H) of the silicone rubber paste during the curing reaction is attached to the unsaturated carbon- Thereby improving the overall curability of the product. In addition, platinum may serve to increase the tensile force and the cohesive force of the second gasket portion manufactured using the second silicone composition according to an embodiment of the present invention.

The second silicone composition according to an embodiment of the present invention may further comprise a first curing agent and a second curing agent so as to improve crosslinking between the silicon hydride and the crosslinking between the silicon hydride and the unsaturated carbon- The weight ratio of the curing agent can be adjusted to 0.9: 1 to 1: 0.9. At this time, the content of the second curing agent may be 5 to 10 parts by weight based on 100 parts by weight of the flame-retardant silicone rubber. If the content of the second curing agent is less than 5 parts by weight, the curing property may be decreased and the curing may not be performed properly. If the content of the curing agent exceeds 10 parts by weight, the fire resistance is decreased. The curing may proceed first and the composition may be hardened.

The flame-retardant silicone resin composition according to the present invention comprises 10 to 40 parts by weight of flame-retardant silicone, 10 to 30 parts by weight of a flame-retardant filler, 40 to 70 parts by weight of fired alumina, 3 to 10 parts by weight of a plasticizer, and 1 to 5 parts by weight of a heat- 1 < / RTI > silicone composition.

Next, the completed first and second sheets are put into an extruder and extruded and processed in the form of first and second gasket portions of a desired size.

Wherein the processing of the first and second gasket portions is performed at a first curing step performed at 600 to 700 캜, a second curing step performed at 210 to 290 캜, a second curing step performed at a horizontal rail having a length of 7 to 8 m, Lt; RTI ID = 0.0 > 220 C < / RTI > and performed in an oven for 3.5 to 4.5 hours. If the primary and secondary curing conditions do not satisfy the above conditions, the composition is not completely cured during the manufacture of the gasket, resulting in a poor stability of the finished gasket, and an uncured cured product can be produced.

Then, the first gasket portion is integrated with one surface of the second gasket portion in a direction perpendicular to both sides thereof. At this time, the first and second gasket portions may have a double bond curing structure.

Hereinafter, examples and comparative examples will be described in order to examine excellent characteristics and effects of the second silicone composition applied to the second gasket portion of the gasket according to the present invention.

[Example]

30 kg of the product name RBB-2400-30 Base of XIAMETER Co., Ltd. is provided by the second silicone rubber and 30 kg of the product name SH 52 U by DOW CORNING is provided by the first silicone rubber.

The product name RBB-2400-30 Base, manufactured by XIAMETER, which is used as the second silicone rubber, has a specific gravity of 1.08 to 1.10, a durometer measurement value of 32 to 37 Durometer Shore A, a tensile strength of 8 to 11 MPa, 740 to 910%, a tear strength of 24.0 to 31.0 kN / m, and a compression set ratio (22 hours, 177 ° C) of 31 to 41%.

The product SH 52 U of DOW CORNING used as the first silicone rubber has a plasticity of 240 or more, a density of 1.1 to 1.2 g / cm 3, a hardness (JIS type A) of 48 to 50, a tensile strength Of 9.1 to 9.5 MPa, an elongation (JIS # 3) of 510 to 550% and a tear strength of 20 to 25 N / mm.

Next, 750 g of PMX-0930 SILANOL FLUID manufactured by XIAMETER Co., Ltd. was mixed with a solid silicone rubber containing the first and second silicone rubbers as a plasticizer, and further 50 kg of expanded graphite (expanded graphite) Knead in Kneader to prepare silicone rubber dough.

Next, 5 kg of the extrusion-flowable agent and 10 kg of the curing agent are mixed in an open roller in the silicone rubber dough and provided in a sheet form. 5 kg of PERKADOX PD-50S-PS containing bis (2,4-dichlorobenzoyl) peroxide and silicone oil of Akzo Noble Polymer Chemical was used as the first curing agent and the platinum catalyst was used as the second curing agent 5 kg of RD-27 from DOW CORNING is used.

Next, a silicone rubber dough produced in a sheet form is extruded from an extruder to produce a gasket.

Table 1 below shows the tensile strength, elongation and tear strength of Samples 1 to 4 prepared through the examples of the present invention, respectively. Referring to Table 1, it can be seen that the present embodiment satisfies all the results of measuring the fire resistance characteristics for 120 minutes under the fire resistance test (C-2) test of the Ministry of Land, Transport and Maritime Affairs Notice No. 2014-200. At this time, the curing agent mixed the first curing agent and the second curing agent at a ratio of 1: 1.

Sample Tensile strength (kgf / cm2) Elongation (%) Tear strength (kgf / cm) One 21.8 351.7 9.26 2 20.4 356.4 9.04 3 19.6 359.3 9.48 4 19.2 335.7 9.85

[Comparative Example 1]

The gasket of Comparative Example 1 uses a liquid silicone rubber instead of the solid silicone rubber, and the other conditions are the same as those of the embodiment.

In the case of Comparative Example 1, since the liquid silicone rubber is used, it is difficult to use an extruder or a molding machine since a silicone rubber dough can not be produced in a sheet form. Further, even if the silicone rubber dough is produced in the form of a sheet, there is a problem that the silicone rubber dough does not have a proper thickness to maintain the fire resistance after extrusion or molding, or holes are generated.

[Comparative Example 2]

The gasket of Comparative Example 2 does not contain expanded graphite, and other conditions are the same as those of the embodiment. Comparative Example 2, which does not contain expanded graphite, has a problem of not only reducing the fire resistance but also significantly lowering the tear strength as compared with the examples. That is, in the case of the gasket according to the present invention, the expanded graphite has excellent fire resistance and tear strength, and the reliability of the product is improved.

[Comparative Example 3]

The gasket of Comparative Example 3 uses only the first curing agent as the curing agent and does not use the second curing agent, and the other conditions are the same as those of the embodiment. The gasket of Comparative Example 3 is insufficiently cured due to the expanded graphite, so that the overall characteristics are reduced compared with the embodiment. That is, in the case of the gasket according to the present invention, the physical properties of the gasket are improved by including the expanded graphite but by improving the hardenability of the second curing agent.

On the other hand, changes in properties were confirmed while changing the total content of the curing agent to 10 to 30 parts by weight based on 100 parts by weight of the solid silicone rubber. According to the second silicone composition of the present invention, since the solid silicone rubber is used, when the total amount of the curing agent is insufficient, the curability is decreased and the characteristics of the produced gasket are deteriorated.

On the contrary, when the curing agent is excessively contained in the silicone composition, the proportion of the solid silicone rubber is relatively decreased, and it is confirmed that the characteristics of the gasket are lowered.

In the present invention, when the content of the curing agent is 5 to 10 parts by weight based on 100 parts by weight of the solid silicone rubber, the characteristics of the gasket to be produced can be improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. something to do.

100, 100 ': Composite extrusion gasket
110, 110 ': a second gasket portion
111, 111 ': second body
112: hollow
113: engaging projection
120, 120 ': a first gasket portion
121, 121 ': first body
122: hollow

Claims (7)

A first gasket portion made of a first silicone composition, the first gasket portion having hollows having a pair of stepped portions formed on opposite sides of the inner surface, the recessed portions being formed on the outer surface; And
A second gasket portion formed of a second silicone composition, the second gasket portion being integrated on one surface of the first gasket portion in the first direction and having a plurality of protrusions formed on both surfaces in a second direction perpendicular to the first direction; Lt; / RTI >
Wherein the first silicone composition comprises a flame-retardant silicone, a flame-retardant filler, a fired alumina, a plasticizer, and a heat-
The second silicone composition may be a solid flame retardant silicone rubber comprising a second silicone rubber and a first silicone rubber having a relatively higher softness than the second silicone rubber, a plasticizer, a heat resisting agent, a flame retardant, an aluminum hydroxide Wherein the expanded graphite comprises 40 to 60 parts by weight based on 100 parts by weight of the silicone rubber dough, and the curing agent is Bis ((Al (OH) ₃ ) and expanded graphite, 2, 4-dichlorobenzoyl) peroxide and a silicone oil, and a second curing agent comprising silica, tetramethyl tetravinyl cyclotetrasiloxane, octamethylcyclotetrasiloxane, a curing retarder and a platinum catalyst, . A first gasket portion made of a second silicone composition, the first gasket portion having hollows having a pair of stepped portions formed on opposite sides of the inner surface, the recessed portions being formed on the outer surface; And
A second gasket portion formed of a first silicone composition, the second gasket portion being integrated on one surface of the first gasket portion in the first direction and having a plurality of projections on both surfaces in a second direction perpendicular to the first direction; Lt; / RTI >
Wherein the first silicone composition comprises a flame-retardant silicone, a flame-retardant filler, a fired alumina, a plasticizer, and a heat-
The second silicone composition may be a solid flame retardant silicone rubber comprising a second silicone rubber and a first silicone rubber having a relatively higher softness than the second silicone rubber, a plasticizer, a heat resisting agent, a flame retardant, an aluminum hydroxide Wherein the expanded graphite comprises 40 to 60 parts by weight based on 100 parts by weight of the silicone rubber dough, and the curing agent is Bis ((Al (OH) ₃ ) and expanded graphite, 2, 4-dichlorobenzoyl) peroxide and a silicone oil, and a second curing agent comprising silica, tetramethyl tetravinyl cyclotetrasiloxane, octamethylcyclotetrasiloxane, a curing retarder and a platinum catalyst, . The method of claim 1 or 2, wherein the first silicone composition comprises at least one of polyalkylalkenylsiloxane, silica and silicon dioxide, and titanium oxide. and,
Wherein the flame-retardant filler comprises quartz, dimethyl siloxane, dimethylvinyl-terminated and titanium dioxide,
Wherein the plasticizer comprises a polymer selected from the group consisting of dimethyl siloxane, hydroxyl-terminated, dimethylcyclosiloxanes, methylcyclopentasiloxane and octamethylcycloterasiloxane, ,
The heat-resistant agent is selected from the group consisting of ceric hydroxide, dimethyl siloxane, hydroxyl-terminated, octamethylcycloterasiloxane, cerium hydrate impurities, Characterized in that it comprises methylcyclopentasiloxane, water and dimethylcyclosiloxanes. The silicone rubber composition according to any one of claims 1 to 3, wherein the silicone rubber paste comprises 0.001 to 0.04 parts by weight of the plasticizer, 0.5 to 1.5 parts by weight of the heat-resistant agent, 1.5 to 4.5 parts by weight of the flame retardant and 10 to 100 parts by weight of the aluminum hydroxide,
The second silicone composition is characterized by comprising 5 to 7 parts by weight of the extrusion chargeable agent, 5 to 10 parts by weight of the first curing agent, and 5 to 10 parts by weight of the second curing agent, based on 100 parts by weight of the flame- Composite extrusion gasket. The method of claim 1 or 2, wherein the weight ratio of the first curing agent to the second curing agent is 0.9: 1 to 1: 0.9, and the weight ratio of the second silicone rubber to the first silicone rubber And a weight ratio of from 0.9: 1 to 1: 0.9. Providing a solid flame-retardant silicone rubber comprising a first silicone rubber, a second silicone rubber and a first silicone rubber having a relatively higher softness than the second silicone rubber;
Preparing a silicone rubber dough by mixing a plasticizer, a heat resistant agent, a flame retardant, aluminum hydroxide, and expanded graphite in the solid flame-retardant silicone rubber;
Mixing the silicone rubber dough with an extruder and a curing agent, and then compounding expanded expanded graphite to form a second sheet of a second silicone composition;
Forming a first sheet of a first silicone composition comprising a flame retardant silicone, a flame retardant filler, a fired alumina, a plasticizer, and a heat resistant agent;
The first sheet is processed into a first gasket portion having a concave portion on its outer surface with a hollow having a pair of stepped portions formed on the inner surface thereof facing each other using an extruder, To a second gasket portion in which a plurality of projections are formed, respectively; And
Integrating a first gasket portion in a direction perpendicular to both sides of the second gasket portion; Lt; / RTI >
In the second silicone composition, expanded graphite is contained in an amount of 40 to 60 parts by weight based on 100 parts by weight of the silicone rubber dough, and the curing agent includes bis (2,4-dichlorobenzoyl) peroxide and silicone oil 1 < / RTI > curing agent and a second curing agent comprising silica, tetramethyl tetravinyl cyclotetrasiloxane, octamethylcyclotetrasiloxane, a curing retarder and a platinum catalyst. 7. The method of claim 6, wherein machining the first and second gasket portions comprises:
A primary vulcanization step carried out at 600 to 700 캜;
A secondary vulcanizing step carried out at 210 to 290 占 폚 and carried out in a horizontal rail having a length of 7 to 8 m; And
A tertiary vulcanization step carried out at 180 to 220 캜 and performed in an oven for 3.5 to 4.5 hours; Lt; / RTI >
Wherein the first and second gasket portions are double bond hardened structures.

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