DE1930713A1 - Process for the production of carbon molded bodies - Google Patents

Description

Pdfenicmwotlt

Fiankiuri / Main-l

13 5959

Kureha Kagaku Kogyo Kabiishiki Kaisha, Tokyo , Japan

Process for the production of carbon molded bodies

The invention relates to a method for producing carbon molded bodies with excellent mechanical strength .

Charcoal moldings are generally produced by that granules or powder aggregates of coke are mixed with pitches or synthetic resins as binders. mixture is brought into the desired shape by extrusion or casting and then the shaped mixture at a temperature of about 1000 C in a non-oxidizing atmosphere is sintered. For the production of electrodes, collector brushes or the like, the sintered carbon bodies are grounded then heat-treated again at temperatures of 2500 C and more, to graphitize them. The graphitized materials are either used as they are or for Adaptation to the intended use further processed in various ways.

Carbon moldings such as electrodes have been used in many branches of industry found a wide application, which has led to their production being carried out in large companies today. The reason for the wide field of application of carbon bodies is to be seen in the fact that they have various excellent properties, although they also have some disadvantages exhibit.

A disadvantage of the carbon moldings is, for example, that they are fragile and have a low mechanical strength.

909882/1274 I.

ν BAD ORIGINAL

point. Since they are also produced in the manner described above ve earthen., will, in the libodax-n not only during the Shaping, but also still slightly during sintering Foam is formed, which is a liquid and thus a Loss of considerable amounts of binding agent as a consequence, so that it is difficult to obtain bodies of high density. Although carbon itself has fairly good mechanical properties, it is difficult to find a suitable one To find the manufacturing process, and when it is used, the End products have these good properties. "

Although these difficulties in some cases by choice "of the raw materials and by improving the factory ax tion processes, for example in the production of molded articles of low gross odor of special items, eliminated they are especially useful in the case of manufacture large moldings or not yet eliminated for those cases in which, for economic reasons, the Costs need to be kept low. It is therefore still difficult to use carbon moldings with sufficient mechanical properties Establish strength.

The invention is therefore based on the problem of avoiding of the disadvantages described indicate a method that can be carried out technically simply and cheaply and molded carbon bodies with high mechanical strength leads.

The invention consists in that a pitch-like mass spun by melt spinning and the spun material by heat treatment in an oxidizing atmosphere, etc. is made meltable and that the infusible fiber material with a mixture of a grain or Powder aggregate and a binder from a pitch or a synthetic resin mixed and then the entire mass into the brought to the desired shape and then charred.

909882/1274

An essential feature of the invention consists in the use of the above-mentioned, unscrewed fiber material, which is obtained from pitch, as a stiffening material for a shaped carbon body and in the advantage achieved thereby *

The stiffening fiber material according to the invention is produced by first; Pitch spun by Sclinielzspinnen which ' ) are easy to spin, Z) can be easily made infusible after spinning and 3) are easy to collapse.

There are a large number of well-spinnable pitches, but these can only be used in the invention if they also include the above-mentioned oi {; c; ischc-.f: Lr. 2) and '_)) own. A very suitable material is rerrolasphalt, whereas normal pure asphalt or tfclasener asphalt in its original state are not suitable for the purposes of the invention if they are not pretreated in such a way that they also receive the other properties mentioned above at the same time.

In general, pitches with the three properties given above are organic compounds which contain condensed polycyclic compounds and / or acyclic compounds as the main constituent, vr ^ cL between r ^ -l. black or dark brown pitches with a carbon junction of £ K> C and more, if one refers to ^ the total n ^ close to Xch.lenstG.Tf and "(lasserstoff, and with an initiate. Mole-lculargev.'iciit of 400 and more, ge _t measure after dex · locking method with Kar-.jier as a solvent. However, Ea may be, also to selche pitchy or resinous substances obtained from dc ~ hydrogenation of condensed polycyclic aromatic compounds represented by pyrolytic table decomposition or heat treatment at high temperature is produced from any hydrocarbon compound and has a softening point of 30 C and more,

909882/1274

BATH ORIGINAL

a Schinelz viscosity of 0.4 poise and more within the have a temperature range set during molding and a carbonization yield of $ 70 and more, with under, " Carbonization yield is understood to mean the yield in the carbonization of the fiber material. «

A melt spinning process is used to spin this pitch applied, which includes extrusion spinning and centrifugal spinning. Both types of spinning are for the inventive Purpose suitable. .

After the end of spinning, the fiber material has the same softening temperature as its raw material, which means that a treatment to render it infusible is necessary in order to maintain its shape, ie to prevent it from melting during subsequent heating. ^: Such a treatment is generally an oxidation of the fiber material in an oxidizing atmosphere. For example, the fiber material is treated in ozone-containing air at a temperature of less than 100 C and then further heat-treated in air by gradually increasing the temperature up to about 260 C, whereby satisfactory results are achieved. In most cases the treatment with ozone can be omitted _; and sometimes chlorine, bromine, SO2 or a nitrogen oxide can also be used instead of ozone in a mixing ratio of 0.5 to almost 100%. Even if the air is completely replaced by one of these gases or a mixture of these gases, the infusibilization treatment will not be affected thereby.

The treatment becomes unschneizbarnachen at a rate of temperature rise from 0.1 to 10 C / min for about 30 minutes to 10 hours.

When the fiber material is heated to close to 260 ° C, is experiments show that it is sufficiently strong

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BATH ORIGINAL '

infusible in that it is used as a stiffening material can be. Since, however, the fiber material during this If the stage of the heat treatment is not yet sufficiently firm, further heating in air or an inactive one Atmosphere preferred up to the range around 500 C, i.e. up to to a temperature just below the carbonization point to to increase its strength.

Although, according to the above description, the infusible threads still have to be carbonized, due to their high carbonizability they can also be carbonized in the course of the sintering of the mixture of the infusible threads with the carbon material, giving them sufficient mechanical strength. Therefore, even if their strength appears to be low after the infusibilization treatment is completed, a remarkable stiffening effect is obtained after the carbon material is sintered. Surprisingly, such a stiffening material has a better effect compared to the case in which carbonized fibers are used. The reason for the better strength is that the fiber material made infusible still has active functional groups, on the basis of which it can be compared with the peclien or · lüiiu? Tliarzen easily connects chemically, whereas the carbonized fibers are chemically inactive, so that they. merely stiffen the end product mechanically. In addition, it is assumed that the lowest tension remains in the carbon molding, since the infusible fiber material maps one of the contraction of the carbon material (mainly due to && x · contraction, of the binding agent) during four sintering.

When using the infusible can barrels of Erwimsc-lr ^ er length he-rges.te4.lt- uiid the with Kohlemarte ^ ia ;! like; - Kgks ^ & n and; Ä

-. with binding ^ e ^ lii wi _; §

BATH

- ο -

or rait the two mixed together at normal or elevated temperatures will. The fiber material can, however, also in the form of woven or non-woven fabrics or mats or in Form of fiber bundles or the like can be used in which the binder is impregnated. The shape of the fiber material , "its mixing ratio with the base material and the mixing process can vary depending on the Moldings can be chosen freely. In general. is the mixing ratio of the infusible Fiber material between 1 and 8p percent by weight,. based on the total amount of the. Basic inte rials.

When shaping the carbon molded bodies according to the invention can use the same equipment and processes as in the manufacture of ordinary carbon bodies or as in the shaping in the Resin technology can be used. In particular, are Extrusion, pressing and impregnation processes, which accordingly can be selected according to the circumstances.

The shaped bodies are charred by conventional sintering methods or, if necessary, ■ graphitized. It is today generally so that in the manufacture of carbon thread the Heat treatment during graphitization is the most expensive process step is because the treatment takes a very long time and large equipment costs are necessary. Although carbon threads various advantageous properties in terms of strength, de.s modulus of elasticity, etc., their industrial use is relative because of the manufacturing cost limited. According to the method according to the invention, however, filaments made infusible are used before they are carbonized, which reduces the manufacturing costs of the shaped carbon bodies in comparison ζμ the case that used expensive carbon thread be, essence-tliph less

BAD OBIÖiNAL

The KohlcforinkSrpcr, who, according to the erf indues ^ omäs s en Processes can result in a wide variety of coal products , e.g. to electrodes, blocks, bricks, and the like processed and also used as intermediate products.

The invention is described in more detail below with the aid of a few examples, which were included in the application with the intention of being patented, but to which the invention is not limited.

Example T

Petrol pitch (manufactured by Daikyo Sekiyu Go., Ltd., Japan) is dry-distilled in a nitrogen atmosphere for two hours at a temperature of 3 ^ 0 C, whereby a black, pitch-like mass with a carbon content of 90.45b, an average molecular weight of 550 and gloss at room temperature. This pitch-like mass is melted and poured into a cylindrical vessel which rotates at a speed of 100 rpm and with which the spinning into fiber material takes place at a temperature of 160 to 180.degree . Ils a mattenf ür.iiigcr, composed of different length Fasermatcrial article is prepared.

This article is is then for three hours at a tem perature of 70 C in air with a -Ozongehait 1.3 $ be, and is then in άατ air with a rose at speed of 1 C per minute / a temperature of 26Q C increases , during which the object is then treated for an hour so that the mat-like structure finally consists of completely infusible , non-melting fibers . .

; In the mat-like object then phenol-formaldehyde \, resin is einimprügniert, "to about 1 to Gewicivcsverhältnis the two substances: 1 is set, the object is Aaschliessend CBX * curing under heat pressed, thereby obtaining an approximately

% I 909882/1274

^: - ^{':' r.} BATH ORIGINAL

5 mm thick plate obtained The cured plate is mounted in nitrogen initially ¹ OO a temperature of 600 C and a ramp rate of 2 C per minute and then .more at a temperature of 1000 C and a rate of rise

charred by 5 C per minute. ■ "'"

The mechanical properties of the finished carbon plate that in Table 1 are significantly better compared to a normal carbon plate.

Table 1 ■ = '.

■ carbon plate with; infusible
! threads made bar as · '- "
} Stiffening material tensile strenght
(kg / cm) 407
- Carbon plate
i normal
quality t - -. ■
Flexural Strength ^: 750
(ke / cnT.),
I · 97 ! ■ - ■
Compressive strength I 1-530
(kg / cm ² ) '
I. 189 370

Example 2

2 parts by weight of coal pitch with a softening point of about 80 ° C. (manufactured by Kawasaki Seitetsu Co., Ltd.) and 1 part by weight of petroleum pitch (manufactured by Daikyo Sekiyu Co., Ltd.) are mixed and heated at a temperature of 380 ° C. in nitrogen for one hour _if 3 dry distilled. This is followed by a treatment for three hours at 300 ° C. under reduced pressure of 10 mm Hg in order to distill off all components with a low molecular weight and to obtain a pitch-like mass with a carbon content of 93.5%. '

909882/127

This, Mass-e; is at eXnep temperature, of 280 C through a nozzle ν, ρη -0.3; mm in air sprayed; "whereby a nitrogen pressure of 2.0 ram. Hg is applied in addition to the pressure of the pressure, while the, ex-t.ruded. mass with a reel gcsclwindxfjkoxi ;. of 300 m / ittin {yeapo.nn.cn The thread obtained in this way is heat-treated for two hours at 40 ° C. in air with an ozone content of 10.4 s / m 2. Subsequently. the T.oniperatxir is raised in. Air with an ". Anstie £ iSiiGschyiildifikoit. 1Q C / h to 20 () C, at what temperature the. thread to. him. completely, mis c hm el ssb a, r to make an hour is kept long. After i. "nitrogen is heated at a Ans.tie.gsgeschwindigkeit 3-5 ° C per minute to 500 ⁰ C.

The threads which are made inaccessible are then to; short threads from 3 to 5 cm length processed .. "30 g hier'votx are with 1000 g of powdered, palcined petroleum coke and 300 g Coal tar mixed, and the mixture is in a löiWei kneaded at a temperature of 1όΟ to 180 C. the kneaded Maase becomes a round stick with a diameter of 3 µm extruded.

The molded body is then carbonized in the usual way and ansciili.tssend graphed by heating to 2800 C. ■

In comparison to a molding that is not infusible

ent & a & t, e, r give the following t /

BAP ORIGINAL

Table 2

Pr ob Erköi ^ - ^ ~ - ~ - ^^
per ■ - ~~~ —-. . 5pe ζ ifi cal
Rubble weight -.- ■■ - · '· -i; ΐ i. . ? .i ίΐ <'Ί
... strength.
· ■. (ke / bWJT ' ¹ ^
- ". · - - · - ■; -. ' el "O ttöv not stiffened by,
made unpalatable
Threads .... _T ^ ₉ - ■ - ■ - · ■ - ■■
■ ; '■ ■ - ■ ■ ^ li ^ .üv / ifjj.-Sg
'■: ' - ". ■. ■ -" Ci- Μ.-ν -: ./ ■ ".. ·« ■ .;
195 stiffened by un
fusible
Threads - · ■■ - - - ...... 1, 60 298

Example 3 ■ - .. "" _., ..,.,. ''.,. "'

A tar-like mass, which is obtained by puffing petrol naphtha at a temperature of 105 ° C., is made into a pecha-like mass: ". light. », components can be removed by distillation under a reduced pressure of 5 π" ²¹ Hg at 300 C. The pecharti ^ e ^ Mäss ^ e has a carbon content of> 9I >> 2 / £ and · Z "7% chlorine ^ publicly insoluble.

This mass is formed into long threads with a diameter of 9 to 13 microns and then in air by raising the temperature to 260 ° C ^{in the same way T} .v-ie in Example 2 at a Texperätur between 320 and 3 ^ 0 0 subjected to a first heat treatment at a rate of increase of 1 to 30 / min. This is followed by a second heat treatment in nitrogen by raising the temperature to 430 ° C. Danäcli a portion OCE threads weiterbehändelt by heating to 10OQ ⁰ C, thereby siöh a braid "results," which both atrs - arr & chmel2bar- made .-- Fjidei a-ls also of carbon-efRdon jew & ils great length i

lift M

dies & sV

ύ & έ,

BATHROOM 0RK3INAL

Then the bundle becomes oii: em stick gnTorir. j, \ .v. ^: iirenrl the material is heated ". Dec * Forii.lcürpcr is ;; crJ.: il, en ;, indei.i the temperature" is sufficient with, an ai.atie'iaiyesciv.-.- indi ^ kei of 0.5 C per min.ite to 500 C and then at an analogue rate of £ 5 per minute to 1000 C ar ., Resulting in a carbon tab.

Tc.b? Lle

^ ruc.c

Specimen

(kg / cm )

stiffened dui * cli unmeltable c thread

2. 1 00

stiffened with carbon thread

53.6

example H

In located at 1800 C D. rr.T3f yird for pyrolytic decomposition seria Roh'Jl ^ cseOen wherein eir.e tar-like mass results, the v / is eiterdestillicrc, ur. to separate the compartments distilling below 25O C and to produce a pitch-like mass that is extremely aromatic. This pitch-like mass is placed together with 5 percent by weight of a Niclcelsystenkatalyst in an autoclave, in which a reaction with vase material is initiated at a temperature of 300 C , in which 23O 1 hydrogen are added per kilogram of the pitch.

The pitchy, blackish brown mass obtained has "inen softening point of 8O to 100 C and a viscosity of about 1.2 Poise at 25? C, and takes sicia excellent pulled into threads. It is melted and from the upper middle

909882 / 127A

BATH

part lier placed in a rotating cylinder nozzle, the one Inside diameter of 150 mm, a depth of 10 mm and im. Sheath has twenty small holes 0.5 mm in diameter. After spinning the pitch-like material at a temperature

temperature of 23O to 25O C with the help of this cylinder nozzle, which rotates at a speed of 2o00 rpm, the mass obtained is first treated in air containing 17 g / m ^{J of} chlorine for three hours at 30 to 40 C and then infusible made by increasing the temperature first in air at a rate of 1 to 2 C / min to Z60 C and then in nitrogen to 450fc. Some of the threads are heated up to 1000 C.

The threads made infusible in this way are processed into a mat into which a pitch of the same type as the pitch used as the starting material for the infusible threads is impregnated up to a weight ratio of about 1: 1. The mat is then pressed into a plate. The plate is carbonized by increasing the temperature to TOOO ⁰ C at a rate of increase of 3 to 5 ° C in nitrogen, whereby a carbon plate is obtained, the properties of which are given in Table 4. Table 4 also shows that the influence of the pitch made infusible according to the invention on the product is considerable.

Table h

Pr ob e kö rp e r "" "- * - ^^^ I.
Flexural strength
(kg / cm ² ) Compressive
speed (kg / cm ² ) stiffened with
260 C infusible
made threads 260
* 480 stiffened with
45O ⁰ C infusible
made threads ■
■
280 540 verfiteiri; ta Lt
Carbon thread
! - '. 220 410
■ it

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ORIGINAL

Claims (1)

Claims 1. A method for producing coal farm bodies, characterized in that a pitch-like Mass spun by melt spinning and the spun material by heat treatment in an oxidizing Atmosphere is made infusible and that the infusible fiber material with a mixture of one Grain or powder aggregate and a binder made of a pitch or a synthetic resin mixed and the whole The mass is then brought into the desired shape and then charred. 2 .. The method according to claim 1, characterized in that that the carbonized molded body is graphite. 3. The method according to claim 1, characterized in that an organic compound is used as the pitch-like mass which contains at least one condensed polycyclisch.es aromatic or an alicyclic compound as the main component, a carbon content of more than 90 percent by weight based on the total amount of carbon and hydrogen and has an average molecular weight of more than 400. 4. The method according to claim!, Characterized in that that a condensed polycyclic compound is used as the pitch-like mass, in which aromatic See and alicyclic components exist side by side, which is produced by heat treatment of a hydrocarbon compound at high temperature and subsequent hydrogenation of the same and which has a softening temperature of 30 ° C. and more, a melt viscosity of 0.4 poise and more within that used in the molding Temperature range and a carbonization yield of? 0 $ and more. '909882/1274 193G713 5. Procedure according to. Claim 1, d a d u r c h g -e k e η "η draws, that the fiber material is made infusible at around 260 C. 6. The method according to claim 5 characterized in _t that the Fasermaierial is further made infusible characterized in that the treatment in an oxidizing atmosphere 'is continued at a temperature of about 500 C, from <below the carbonization temperature. 7 · The method according to claim 6, characterized η e t that it is carried out in an inactive gas atmosphere. 8. The method according to claim 5 | characterized thereby- { records that it is in with ozone, chlorine, bromine, sulfuric acid hydride or air mixed with nitrogen oxide. 9. The method according to claim 8, characterized geke.nnz e i c h η e t that the air through one of the said Gases is replaced. . 10. A method according to claim 8, characterized the air two of the said gases is replaced gekennz ei ch η et _f that by a mixture of at least ^v. 11. Method · according to claim 5 »marked thereby e i ch ne t that treatment 30 minutes to 10 hours is carried out at a temperature rise rate of 0.1 to 5 C per minute. 12. The method according to claim 1, characterized! shows that the infusible fiber material is added in a proportion of 1 to 85 percent by weight of the mixture of aggregate and binder. i 909882/1274 - Λ-j - 13 · Procedure according to. Claim, characterized in that the Faserr.iaterial in a 4 -! ^ - ^acne form accommodated and / wove a cloth or fiber nonwoven cloth is processed for example to a Filzraatte. RevS / Schl June 16, 1969 127 A . BAD ORlGlNAl-