JP2001151574A - Method of producing glassy carbon pipe and glassy carbon pipe produced by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a glassy carbon pipe, which is suitable for obtaining a pipe having a small diameter and a long size or a pipe being linear, branched or bent in the whole form with a good precision, and to provide the glassy carbon pipe suitable for obtaining a pipe having a small diameter and a long size or a pipe being linear, branched or bent in the whole form with a good precision. SOLUTION: The method of producing the glassy carbon pipe is comprised of producing thermosetting resin cured materials, each having a form obtained by dividing a pipe, then bonding these materials to integrate and firing the jointed material to carbonize. The glassy carbon pipe obtained by this method is also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a glassy carbon pipe used as a pipe for transferring gas, liquid, and the like, and a glassy carbon pipe obtained by the method.

[0002]

2. Description of the Related Art Generally, for pipes used for piping, metal-based materials such as stainless steel and copper, and resin-based materials such as vinyl chloride resin, polyethylene resin, and fluorine-based resin are generally used. However, a metal-based material has relatively high heat resistance, but has poor chemical resistance, and thus has a problem of metal contamination, in which a metal component is eluted by being eroded by a transfer substance. In addition, resin-based materials have excellent chemical resistance but poor heat resistance. For example, the heat resistance of a commonly used fluororesin is at most 150-2.
It is about 50 ° C. One of the materials having excellent heat resistance and chemical resistance is glassy carbon.

[0003] Glassy carbon is a carbon material obtained by carbonizing and sintering a thermosetting resin, and has a very homogeneous and dense glassy structure. This material has heat resistance and chemical resistance as well as conductivity, chemical stability, which are characteristics of general carbon materials,
Excellent properties such as high purity, no falling off of constituent particles,
It has an excellent feature of impermeability. For this reason, it is considered that glassy carbon is suitable for a pipe for piping when a highly reactive gas or liquid is used, or when used in a high temperature environment.

Therefore, when a pipe is manufactured by using glassy carbon having characteristics such as chemical stability, chemical resistance, heat resistance, and high purity, a conventional known method requires (1) thermosetting resin. A method in which a cured product is machined into a pipe shape and carbonized and calcined. (2) A thermosetting resin cured product is carbonized and calcined. The lath-like carbon is used as a material and machined using a diamond tool or the like. To give a pipe shape,
(3) A method of pouring a thermosetting resin as a raw material into a mold, forming a pipe-shaped product, curing the material, and carbonizing and firing the same. (4) Thermosetting resin, injection molding, etc. Is formed into a pipe shape, and carbonized and baked. However, when a glassy carbon pipe is manufactured by these methods, it is difficult to cope with a small diameter or long shape, and it is also difficult to manufacture a branched or bent pipe.

[0005]

SUMMARY OF THE INVENTION The invention according to claim 1 is suitable for accurately obtaining not only small-diameter, long-length pipes, but also pipes whose entire shape is straight, branched or bent. A method for producing a glassy carbon pipe is provided. The invention according to claims 2 and 3 provides a glassy carbon pipe suitable for accurately obtaining a pipe whose entire shape is branched or bent, in addition to a pipe having a small diameter and a long shape. is there.

[0006]

According to the present invention, there is provided a vitreous glass characterized in that a cured product of a thermosetting resin having a shape obtained by dividing a pipe is produced, and then bonded and integrated, followed by carbonization and firing. The present invention relates to a method for manufacturing a carbon pipe. Further, the present invention relates to a glassy carbon pipe obtained by the above-mentioned production method. Furthermore, the present invention relates to the above-mentioned glassy carbon pipe, wherein the whole pipe has a straight, branched or bent shape.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The vitreous carbon referred to in the present invention is:
It is generally known, and is a hard amorphous carbon having a black glass appearance and a brilliant shell-like fracture surface.
Vitreous carbon is generally obtained by carbonizing and firing a cured thermosetting resin. The thermosetting resin used is not particularly limited, and examples thereof include a phenol resin, an epoxy resin, an unsaturated polyester resin, a furan resin, a melamine resin, an alkyd resin, and a xylene resin. Further, a mixture of these resins may be used, and a curing catalyst for the resin is used as needed.

[0008] The glassy carbon pipe of the present invention comprises:
Create a thermosetting resin cured product in the shape of a divided pipe,
Next, these are adhered, cured, integrated, and then carbonized and fired. There is no particular limitation on the method of forming the pipe into a divided shape, but in order to form a pipe, it is necessary to form a hollow portion, a so-called channel, in the center (inner surface). In the case of forming by processing, a method of forming grooves in a shape obtained by dividing the final pipe shape on a flat plate of a cured thermosetting resin, and then bonding and curing them to integrate them is easy to process. It is preferable because it is possible. Hereinafter, a method for producing a glassy carbon pipe will be described in detail.

The thermosetting resin used as a raw material of the cured thermosetting resin may be a powdery or liquid thermosetting resin, and is not particularly limited. As the thermosetting resin used for bonding, it is preferable to use a liquid or paste thermosetting resin from the viewpoint of easy handling. When a powdery thermosetting resin is used, it is used after being made into a liquid or paste form by a method such as dissolution in an organic solvent. Furthermore, it is preferable to use the same type of thermosetting resin to be used for bonding and the same type of thermosetting resin to be used for bonding, from the viewpoint of preventing cracking and peeling due to a difference in shrinkage during firing. From these viewpoints, preferred examples of the thermosetting resin include a furan resin, a resol-type phenol resin, and a mixed resin thereof.

The above-mentioned thermosetting resin can be molded by various molding methods in order to obtain a desired glassy carbon pipe. The shape of the groove on the outer surface (outer periphery) and the inner surface of the pipe is not particularly limited, and examples thereof include a circular shape, a substantially circular shape, and a square shape (a polygonal shape such as a triangular shape, a square shape, and a pentagonal shape). The shape is preferably a square or a circle in terms of ease of handling. Although the angle of the groove may be a corner (edge), it is preferable to provide R (R) of 0.2 mm or more from the viewpoints of crack prevention, chipping prevention, workability and the like.

The method for molding the thermosetting resin is not particularly limited. For example, (1) molding into a flat plate by casting; To one place, and unfold it into a flat plate,
(3) A method of forming the pipe into a shape close to a desired pipe in advance is exemplified. In addition, since glassy carbon greatly shrinks during carbonization and firing, it is preferable to manufacture a molded body with a size that allows for this shrinkage.

After being formed into a flat plate by the above method, 50 to 50
Heat treatment is performed at 150 ° C. to sufficiently cure the thermosetting resin. In order to easily remove volatile components contained in the resin at the stage of the thermosetting resin molded product in the rubber state, it is preferable to perform rough processing such as a preliminary groove to reduce the thickness. 5
At the stage where the heat treatment at 0 to 150 ° C. has been completed, machining is performed using NC machining or the like in a size in consideration of the shrinkage ratio during firing to obtain a thermosetting resin cured product having a divided pipe shape.

In the present invention, it is preferable that a cured product of a thermosetting resin is formed in a shape obtained by dividing a pipe in advance, and then bonded using a liquid or paste-like thermosetting resin. After the bonding, heat treatment at 50 to 150 ° C. is preferably performed again to cure the resin in the bonded portion. After the heat treatment of the bonded portion, it is preferable to further perform a heat treatment at a maximum temperature of 150 to 300 ° C. to promote the entire curing. here,
Insufficient curing of the thermosetting resin causes defects in the structure during firing, and if it is severe, foaming and cracking occur, making it impossible to obtain sound glassy carbon.

The method of dividing the pipe is not particularly limited, but may be divided into two to five in the longitudinal direction of the pipe, or as shown in FIGS. 1, 2 and 3, in the longitudinal direction of the pipe. It is preferable to divide the pipe into two parts in a direction parallel to the direction, that is, to divide the pipe into two parts vertically, from the viewpoint of easiness of processing, simplicity of bonding and the like. In addition, with respect to the length direction of the pipe,
The division may be performed in both the parallel and vertical directions.

The structure of the bonding portion is not particularly limited. For example, a structure in which planes are simply joined to each other, FIG.
As shown in (1), there is a fitting structure in which the fitting portions 3 are formed and the fitting portions 3 are fitted to each other. However, in the present invention, a large bonding area can be obtained, the bonding strength and the displacement prevention at the time of bonding can be achieved. In view of the above, it is preferable to adopt a fitting structure.

The pipe-shaped thermosetting resin which is bonded, cured and integrated by the above-mentioned method is placed in an inert atmosphere (usually, an inert gas such as helium, argon or the like, nitrogen, hydrogen, halogen gas or the like). An oxygen-free atmosphere composed of at least one non-oxidizing gas, under reduced pressure or vacuum,
Temperature of about 900 ° C. or more, preferably 1 ° C. in an atmosphere in which the atmosphere is blocked by being buried in graphite powder, carbon powder, or the like.
Carbonization and firing at a temperature of 000 ° C or higher. Thereafter, high-temperature heat treatment is preferably performed at 1300 ° C. to 3000 ° C. to obtain a glassy carbon pipe.

It is preferable to use a jig for preventing deformation during carbonization firing and high-temperature heat treatment in order to prevent deformation of the obtained pipe. The jig material is not particularly limited as long as it is not deformed or deteriorated at each processing temperature, but graphite material, preferably graphite material having an ash content of 20 ppm or less is preferable in terms of workability, thermal expansion coefficient, prevention of metal impurity contamination, and the like. It is preferred to use

The overall shape of the glassy carbon pipe according to the present invention may be a straight shape or a shape branched or bent from the middle, and is not particularly limited. The term "bend" means both a state of being bent at a right angle and a state of being bent in a meandering manner.

The size of the glassy carbon pipe according to the present invention, that is, the total length, the wall thickness, the size of the groove which becomes a cavity, the size of the so-called inner surface, and the like are not particularly limited. From the viewpoint of preventing deformation during heat treatment, etc.
00 mm or less is preferable, and 800 mm or less is more preferable,
The range of 100 to 500 mm is more preferable. The thickness is preferably in the range of 0.5 to 10 mm, more preferably in the range of 0.8 to 7 mm, from the viewpoint of curing of the resin, workability, and the like.
The range of mm is more preferred. The dimension or diameter of one side of the inner surface of the groove portion to be a cavity is 1 to 30 from the viewpoint of workability and the like.
The range of mm is preferable, the range of 2 to 20 mm is more preferable, and the range of 3 to 10 is further preferable.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. Example 1 Furan resin precondensate (trade name V, manufactured by Hitachi Chemical Co., Ltd.)
F-302) 1.0 part by weight of a curing agent consisting of 30 parts by weight of paratoluenesulfonic acid and 70 parts by weight of ethylene glycol was added to 100 parts by weight, and after sufficiently mixing, the mixture was degassed under vacuum and centrifuged. A cylindrical molded body in a rubber state was molded at a temperature of 40 ° C. with a machine. This cylindrical molded body is cut at one place in the vertical direction, and it is developed to have a length of 400 mm.
A flat molded body having a width of 160 mm and a thickness of 8 mm was obtained.
This molded body was divided into four parts each having a width of 40 mm in the rubber state.

Thereafter, they are kept at 40 ° C. for 5 days at 60 ° C.
For 10 days and at 100 ° C. for 5 days to obtain a flat resin cured product. Next, each flat resin cured product is processed by NC machining to a required size in consideration of the shrinkage rate in firing and high-temperature treatment, and the pipe is vertically divided as shown in FIG. 1 and FIG. (Resin direction) was obtained.

Next, two of the above resin cured products are used, and they are opposed to each other in a pipe shape shown in FIG.
Furan resin initial condensate (trade name V, manufactured by Hitachi Chemical Co., Ltd.)
F-302) To 100 parts by weight, 1.0 part by weight of a curing agent consisting of 30 parts by weight of paratoluenesulfonic acid and 70 parts by weight of ethylene glycol was added, and a well-mixed mixture was used as an adhesive to bond. As shown in FIG. 2, the bonding portion was a fitting structure in which the fitting portions 3 were fitted together, and the corners of the groove 2 were processed to have a radius of 0.2 mm when completed. After the bonding, in order to cure the resin at the bonding portion, two days at 40 ° C., three days at 60 ° C., and one day at 100 ° C.
Daily heat treatment was performed. Further, heat treatment was performed at 150 ° C. for 2 days to obtain a cured resin having a square inner and outer surfaces.

A jig made of graphite material for preventing deformation is installed on the resin cured product having a square inner and outer surface obtained above, placed in an electric furnace, and heated to 1000 ° C. in a nitrogen stream at a rate of 2 ° C./hour. The temperature was raised at a rate, and the temperature was kept at 1000 ° C. for 2 hours to perform carbonization and firing. Thereafter, the temperature was raised to 2000 ° C. at a rate of 10 ° C./hour in an inert atmosphere using a graphite deformation preventing jig having an ash content of 20 ppm or less.
A high-temperature treatment was carried out by holding at a temperature of 000 ° C. for 3 hours to obtain a glass-like carbon pipe having a square shape on the inner and outer surfaces with a dimension of one side of the outer surface of 10 mm, a size of one side of the inner surface of 4 mm, and a total length of 250 mm.

In the same manner, a total of four glass-like carbon pipes having a square inner and outer surface were manufactured. In order to check the soundness of the pipes, one side of all four pipes was plugged, and acetone was poured to check for leaks. No liquid leak was found from the adhesive portion or the like. A pressure resistance test was performed at a pressure of 0.2 MPa (2 kgf / cm ² ) using helium gas, and no leakage was observed. Further, when one of them was cut to check the bonded portion, it was confirmed that the bonded portion was completely integrated.

Example 2 The resin mixture obtained in Example 1 was degassed under vacuum and cast on a tray to obtain a flat molded body having a length of 350 mm, a width of 350 mm and a thickness of 6 mm. Thereafter, the plate-shaped molded body is sandwiched between graphite plates, and heat-treated at 40 ° C. for 6 days, 70 ° C. for 5 days, and 100 ° C. for 4 days, and curing proceeds to obtain a plate-shaped resin cured product. Was. Next, processing was performed using NC machining to a required size in consideration of the shrinkage rate in firing and high-temperature treatment, and a resin cured product in which a cross-shaped pipe branched in the middle was vertically divided into two parts was obtained. .

Next, two of the above-mentioned cured resin materials were used, and they were opposed to each other so as to form a pipe, and were bonded using the adhesive obtained in Example 1. The bonding portion was a fitting structure in which the fitting portions were fitted together in the same manner as in Example 1, and the corners of the groove were processed to have a radius of 0.3 mm when completed. After the bonding, in order to harden the resin at the bonded portion, a heat treatment was performed at 40 ° C. for 2 days, at 60 ° C. for 3 days, and at 100 ° C. for 1 day, sandwiched between graphite jigs. 150 ° C
And a heat treatment was performed for 2 days to obtain a cross-shaped resin cured product in which the inner and outer surfaces were each square and the whole branched in the middle.

The inner and outer surfaces obtained above are square, and a cross-shaped groove-shaped graphite-made deformation-preventing jig is installed on the cross-shaped resin cured product which is branched in the middle, and the electric furnace is installed in the electric furnace. Get in,
Through the same steps as in Example 1, the dimension of one side of the outer surface is 8 mm,
A glass-like carbon pipe having an overall shape of a cruciform shape with an inner side dimension of 4 mm and a tip of each pipe branched from the center of the cruciform shape of 120 mm was manufactured.

Next, in order to confirm the soundness of the pipe, three places at the opening of the pipe were closed, and acetone was poured to check for leakage. No liquid leakage from the adhesive portion or the like was observed. Further, a pressure resistance test was performed in the same manner as in Example 1, but no leakage was observed.

Example 3 A resole type phenolic resin (trade name: VP-13N, manufactured by Hitachi Chemical Co., Ltd.) was degassed under vacuum, cast into a tray, and had a length of 200 mm, a width of 200 mm and a thickness of 200 mm. A 6 mm flat molded product was obtained. Thereafter, the flat molded body was sandwiched between graphite plates, and was placed at 40 ° C. for 5 days, at 70 ° C. for 4 days, and at 10 ° C.
Heat treatment was carried out at 0 ° C. for 3 days to proceed with curing to obtain a flat resin cured product. Next, processing is performed using NC machining to a required size in consideration of the shrinkage rate in firing and high-temperature treatment, and a cured resin product is obtained in which an L-shaped pipe bent in the middle is vertically divided into two parts. Was.

Next, two of the above resin cured products were used, faced in a pipe shape, and bonded using the above-mentioned resole type phenol resin as an adhesive. The bonding portion was a fitting structure in which the fitting portions were fitted together in the same manner as in Example 1, and the corners of the groove were processed to have a radius of 0.3 mm when completed. After bonding, sandwiched between graphite jigs to cure the resin at the bonded part,
At 60 ° C. for 3 days and at 100 ° C. for 1 day. Further, a heat treatment was performed at 150 ° C. for 2 days to obtain a resin cured product in which the inner and outer surfaces were each square and the whole was L-shaped.

The inner and outer surfaces obtained above are square and the whole is L
An L-shaped grooved graphite-made jig for preventing deformation is installed in the resin-cured resin-shaped product, placed in an electric furnace, and subjected to the same process as in Example 1 so that the dimension of one side of the outer surface is 8 mm. An L-shaped glassy carbon pipe having an L-shaped overall shape was manufactured, in which the length from one side of the inner surface was 4 mm and bent from 90 degrees to the tip of each pipe was 120 mm.

Next, in order to confirm the soundness of the pipe, one side of the opening of the pipe was closed, and acetone was poured to check the leakage. No leakage of liquid from the adhesive portion or the like was observed. Further, a pressure resistance test was performed in the same manner as in Example 1, but no leakage was observed.

COMPARATIVE EXAMPLE 1 The resin mixture obtained in Example 1 was evacuated under vacuum, cast into a tray, and was 350 mm long, 350 mm wide and 11 mm thick.
Was obtained. After sandwiching this compact between graphite plates,
Heat treatment was performed at 40 ° C. for 6 days, at 70 ° C. for 5 days, and at 100 ° C. for 4 days to proceed with curing to obtain a plate-shaped cured resin. This resin cured product was machined into a cylindrical shape, and a lathe was used to machine a round hole at the center of the diameter. However, the hole diameter was small and the hole was deep, so a thin and long tool vibrated. It was impossible to process it and production was suspended.

[0034]

The pipe made of glassy carbon obtained by the method of claim 1 is a pipe made of glassy carbon whose entire shape is straight, branched or bent in addition to a small-diameter and long pipe. Is easily and accurately obtained. The pipe made of glassy carbon according to claims 2 and 3,
In addition to small diameter and long pipes, the whole shape can be straight, branched or bent, and is industrially extremely suitable.

[Brief description of the drawings]

FIG. 1 is a longitudinally divided resin cured product of a glassy carbon pipe used in one embodiment of the present invention.

FIG. 2 is a plan view showing a structure in which an adhesive portion of a thermosetting resin cured product having a divided shape is fitted.

FIG. 3 shows a resin cured product obtained by vertically dividing a glassy carbon pipe used in another embodiment of the present invention into two parts.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin hardened material 2 Groove 3 Fitting part

Claims (3)

[Claims] 1. A thermosetting resin cured product having a shape obtained by dividing a pipe is produced, and then these are adhered and integrated.
A method for producing a glassy carbon pipe, which comprises carbonizing and firing. 2. A glassy carbon pipe obtained by the method according to claim 1. 3. The glassy carbon pipe according to claim 2, wherein the entire shape of the pipe is a straight, branched or bent shape.