JPH02275193A - Heat insulating material for high temperature pressurizing device - Google Patents

Abstract

PURPOSE:To improve heat resistance and strength of a heat insulating material for high temperature pressurizing device by specifying the bulk density in a carbon porous body made by carbonizing phenol resin foaming substance. CONSTITUTION:In a heat generating device 3, a lower pressurizing member 4 and an upper pressurizing member 5 are opposed to each other and one side at least is installed so that it can slide. A carbon porous body made by carbonizing phenol resin foaming substance is used as the pressurizing members 4, 5 of a hot press device. The bulk density of the carbon porous body is made 0.2-0.8g/cm<3>. It is thus possible to make a heat insulating material for high temperature pressurizing device excellent in its heat resistance and strength and decrease its heat loss.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a heat insulating material suitable for a pressurizing member and a heat insulating layer of a high temperature pressurizing device.

<Prior art and its problems> High-temperature press equipment, such as hot press equipment and hot isostatic press equipment, are used for processing such as forming, sintering, and diffusion bonding of metals, fine ceramics, and carbon materials. has been done.

The structure of these devices, taking a hot press device as an example,
The explanation will be based on the drawings.

FIG. 1 is a schematic diagram showing a cross section of a hot press device. In this device, a heat insulating material layer 2 is provided inside a housing l. Further inside thereof, a heat generating device 3 is provided.

Note that the heat generating device 3 is a resistance heating heating element in the case of the resistance heating method, and an induction heating coil in the case of the induction heating method.

Further inside the heat generating device 3, a lower pressure member 4 and an upper pressure member 5 are provided facing each other, at least one of which is slidably provided. Lower pressure member 4 and upper pressure member 5
A mold member consisting of a male mold 6 and a female mold 7 is installed between the two. The object to be treated 8 is placed between the male die 6 and the female die 7.

To show an example of the treatment process, first, the inside of the system is heated by the heat generating device 3. The atmosphere at this time is pressurized, normal pressure, or reduced pressure. The heating temperature varies depending on the type of object 8 to be treated and the purpose of the treatment, but in the case of sintering fine ceramics, it exceeds 2000 ° C. Sometimes. When a predetermined temperature is reached, the lower pressure member 4 or the upper pressure member 5 is raised and lowered to pressurize the mold material, thereby pressing the workpiece 8.

That is, the desired treatment is performed by heating and pressurizing the hot press device. Of course, a method of heating in a pressurized state may also be adopted.

In the above process, heat and stress are applied to the lower pressure member 4 and the upper pressure member 5 each time the process is performed. Therefore, heat-resistant and strong materials such as graphite and ceramics are usually used for the member. However, ceramics soften at high temperatures and reduce their strength, so they are rarely used at present, and graphite is exclusively used.

Although graphite is an excellent material in terms of strength, it has the disadvantage of extremely high thermal conductivity and high heat loss. For this reason, conventionally, it has been difficult to increase the size of hot press equipment.

As a countermeasure for this, as shown in FIG. 2, only the parts where the temperature rises the most and the pressure is applied are placed using a graphite pressurizing member 4.
5, and the remaining back-up layer 9 is made of heat-insulating material, for example, ceramics, but as mentioned above,
Since graphite has extremely good thermal conductivity, heat is directly transmitted to the backup layer 9, and due to the above-mentioned problem with the heat resistance of ceramics, the temperature cannot be raised, and the problem has not been solved.

As described above, there is a need for a material that has both heat resistance and strength suitable for the pressurizing member of a high-temperature pressurizing device.

<Problems to be Solved by the Invention> The present invention attempts to solve the problems associated with the prior art as described above, and provides a high-temperature pressurizing device suitable for use in areas where stress and temperature are applied at the same time. The purpose is to provide insulation materials for

<Means for Solving the Problem> That is, the present invention provides a carbon porous body obtained by carbonizing a phenolic resin foam, which has a bulk density of 0.2 to 0.8 g/
This is a heat insulating material for a high temperature pressurizing device characterized by being ca+'.

Hereinafter, regarding the heat insulating material for high temperature pressurizing equipment according to the present invention,
I will explain in detail.

The carbon porous body constituting the heat insulating material for a high temperature pressurizing device according to the present invention is obtained by carbonizing a phenolic resin foam.

This phenol resin foam is obtained by foaming and curing a phenol resin, and a resol type phenol resin is used as such a phenol resin.

A resol type phenolic resin is obtained by reacting phenols and aldehydes in the presence of an alkali catalyst according to a known method.

Specifically, phenols include phenol, cresol, xylenol, resorcinol, and the like.

Specifically, formaldehyde, acetaldehyde, furfural, and the like are used as the aldehydes.

As the alkali catalyst, specifically, KOH, NaOH% NH, NH4OH, r-tanolamine, ethylenediamine, etc. are used.

As the foaming agent for foaming the resol type phenolic resin, various conventionally known decomposition type foaming agents and evaporation type foaming agents can be used. Among these, evaporative blowing agents are preferred, and specific examples include paraffinic hydrocarbons, alcohols, ethers, halogenated hydrocarbons, etc. Among them, halogenated hydrocarbons are most preferably used. be able to.

Specifically, halogenated hydrocarbons include chloroform, carbon tetrachloride, trichloromonofluoromethane (Freon gas R11), dichloromonofluoromethane (Freon gas R11), and dichloromonofluoromethane (Freon gas R11).
21), tetrachlorodifluoroethane (same R112)
, )-lichlorotrifluoromethane (R113), dichlorotetrafluoroethane (R114), dibromotrifluoroethane (R114B2), and the like are preferably used.

Among these, especially fluorocarbon gas R11, fluorocarbon gas R113,
Those having a boiling point at room temperature or slightly higher temperature, such as R114B2, are preferably used. The blowing agent is 1 part by weight per 100 parts by weight of the resol type phenolic resin.
It is preferable to use ~30 parts by weight.

In order to foam and harden resol type phenolic resin,
A curing agent is used together with the foaming agent, and various conventionally known curing agents are selected and used depending on the type of prepolymer. in particular,
Examples include sulfuric acid, hydrochloric acid, phosphoric acid, phenolsulfonic acid, benzenesulfonic acid, toluenesulfonic acid, metacresolsulfonic acid, resorcinolsulfonic acid, butylsulfonic acid, and propylsulfonic acid.

Such a curing agent is usually used in an amount of 3 to 30 parts by weight per 100 parts by weight of the resol type phenolic resin.

Further, in the present invention, other components such as foam stabilizers and fillers may be used in combination as necessary.

The production of a phenolic resin foam from a resol-type phenolic resin, a blowing agent, and a curing agent as described above involves mixing and stirring these raw materials all at once or sequentially to produce a creamy phenolic resin prepolymer composition. is supplied, for example, into a heated mold or onto a 21i belt conveyor, and the phenolic resin prepolymer composition is foamed.
It is done by curing. The obtained resin foam may be cut as necessary.

The molded phenolic resin foam thus obtained is carbonized by being fired in a non-oxidizing or slightly oxidizing atmosphere, either directly or after being cut into a desired shape.

That is, the firing is performed under reduced pressure or in Ar gas, He gas, N2 gas, halogen gas, ammonia gas, hydrogen gas, carbon oxide, etc., preferably at a temperature of 600° C. or higher, more preferably 900° C. or higher. In this way,
The foam is carbonized to obtain a carbon porous body with excellent strength.

If the firing temperature is less than 600°C, a carbon porous body is often obtained which is not sufficiently carbonized and undergoes dimensional changes again during use. In carbonization, if you want to intentionally advance to graphitization, the firing temperature should be set to 1800℃.
This is possible by doing the above. Graphitized carbon porous bodies are particularly excellent in terms of oxidation resistance and mechanical strength.

Further, although there is no particular restriction on the rate of temperature increase during firing, it is preferable to increase the temperature gradually around 200 to 600°C, where decomposition of the resin generally starts.

The carbon porous body obtained in this way has a bulk density of 0,
It is in the range of 2 to 0.8 g/cm', preferably 0.25 to 0.5 g/cm'.

If the bulk density is less than 0.2 g/cm3, the strength will be poor;
It cannot withstand stress during pressurizing operations, and on the other hand, if the bulk density exceeds 0.8 g/cm', the insulation performance will be poor.

For example, the specific carbon material as explained above is
When used as the pressure member 4.5 of the hot press device shown in the figure, the carbon porous material not only can sufficiently withstand stress during pressurization, but also has almost no permanent deformation due to stress, so it is sufficient as a structural material. In addition, the carbon material has heat resistance and heat insulation properties that conventional products did not have, resulting in less heat loss in the equipment and therefore reducing the press area, which was previously limited in terms of heat loss. This has the advantage of being able to increase the size.

Note that this specific carbon material can also be used as a material for the heat insulating layer 2.

<Examples> Next, the effects of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way unless the gist thereof is exceeded.

(Example 1) (Production of porous carbon material) 100 parts by weight of resol, 10 parts by weight of para-toluenesulfonic acid as a hardening agent, and fluorocarbon gas (as a blowing agent)
Thoroughly stir 2 parts by weight of Freon 11) with a high-speed mixer.
After mixing, pour the mixture into a wooden mold, cover it, and
By leaving it in an air oven at 0℃ for 30 minutes,
A phenolic resin foam having a bulk density of 0.30 g/cm' was obtained.

From this foam, measure 20cm long and 20cm wide.

A board with a thickness of 5 cm was cut out.

This plate was placed in a Matsufuru furnace, and after replacing the atmosphere with N2, the temperature was raised to a temperature of aOO°C at a heating rate of 60°C/min, and then transferred to a graphitization furnace and treated at 2000°C under the same <N2 atmosphere. A porous carbon material having a bulk density of 0.29 g/cm'' was obtained.

[Performance evaluation]

From the carbon porous body produced by the above method, 50 x 50 x 25
A mm test piece was cut out. This test piece was repeatedly subjected to a stress of 50 kg/cff12 using a compression testing machine for 200
The load was applied 0 times, and the dimensional change of the test piece before and after the test was shown as permanent strain. Further, the thermal conductivity of the carbon porous body at aOO°C was measured using a hot wire method thermal conductivity measuring device. The results are shown in Table 1.

(Comparative Example 1) In Example 1, the amount of blowing agent was increased, and the bulk density was 0.12 g.
/cm' was produced.

The same performance evaluation as in Example 1 was performed on this carbon porous body. The results are shown in Table 1.

(Comparative Example 2) The same performance evaluation as in Example 1 was performed using a commercially available graphite material with a bulk density of 1.8 g and 7 cm3. The results are shown in Table 1.

Table 1 When used as a device, the heat loss of the device is small.

Therefore, it is possible to increase the press area of the high-temperature press device, which has hitherto been limited due to heat loss.

<Effects of the Invention> According to the present invention, a heat insulating material for a high temperature pressurizing device having excellent heat resistance and strength is provided.

The heat insulating material for high temperature pressurizing equipment of the present invention has a bulk density of 0.2 to 0.
．． Since it is made of 8g/cm3 carbon porous material, it can not only sufficiently withstand stress during pressurization, but also has almost no permanent deformation due to stress, and can be fully used as a structural material.In addition,
This porous carbon material has heat resistance and heat insulation performance not found in conventional products, so this type of heat insulation material can be used as a pressurizing member.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a cross section of a hot press device. FIG. 2 is a schematic diagram showing a cross section of another hot press device. Explanation of symbols 1...Housing, 2...Insulating material layer, 3...Heating device, 4...(Lower) pressure member, 5-(Upper) pressure member, 6...Male type , 7... Female mold, 8... Processing object, 9... Barracup layer FIG, 1

Claims (1)

[Claims] (1) A heat insulating material for a high-temperature pressurizing device, which is a porous carbon material obtained by carbonizing a phenolic resin foam, and has a bulk density of 0.2 to 0.8 g/cm^3.