DE1646790A1 - Process for the production of carbonated products - Google Patents

Description

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North American Aviation, Inc., El Segundo, California, V.St.A.

Process for the manufacture of carbonized products

The invention relates to a method for producing novel Compounds, in particular a process for the production of carbonized Products made from rigid polymeric structures composed of ßenzene rings.

It has hitherto generally been assumed that polyaromatic Compounds in which the benzene rings are all directly connected to one another, are rigid or stubborn. * P.h., it became not suspected that such compounds are of practical use. -αι. '·;

k "stai-r" in "drawing to

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Polynnerous substances indicates that the * formed substance. ' v / o <.: 'he c ^e ~ melted still dissolved in a solvent or treated on the same basis, so that design and shaping takes place from the base material powder, as from the Ur / .cetzung arises in order to produce the substance. Examples of polyalignic compounds that play a role here are polytoluene, polynaphthylene and polyphenylenes. In addition, the ience in these structures can have substituents such as halogenators, including chlorine, and the like.

However, it has been found that a cohesive mass is achieved can be, if one of the polyaromaticL compounds that normally in the form of a powder as it is manufactured, pressed together under pressure in a press. According to the invention this compact mass is then exposed to high temperatures in an oven, during which the material is pyrolyzed »the pyrolyzed Material has new and unusual properties and represents a new kind of cash register.

The present invention relates to polyaromatic compounds. It relates in particular to polymers in which the bond 'in the polymer chain runs from ring to ring. It is believed that when pressed together, the benzene rings that make up the structure arrange themselves in a regulated pattern, because it is present in a crystal-like substance. Weuer can do this with non-aromatic polymers or with aromatic polymers be achieved, "in which a compression does not occur, -iei

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pyrolysis of compressed polyamatic compounds the novel products according to the invention are obtained which have chemical properties similar to graphite. This However, the material is harder than graphite and has more distinctive features Features as shown below. The resulting pyolyzed product has layers as indicated ruk doors caused by the initial compression of the benzene rings erh '-. it ·· η be. . .

The material produced can be used wherever graphite is normally used, such as, for example, 3. as electrodes, flame tube inserts for rocket propulsion systems, rocket propulsion nozzles> a variety of fiber material and headlight carbon, to name just a few possible applications. Of the same or even greater significance is the fact that filler material can be incorporated with the aid of the method in accordance with the invention, below the pyrolyzed polymers according to the invention as an agent for this Resistant bodies (|:. produce carbon base by pressing the polymer before pyrolysis together with substances such as 3. the resulting coating pyvolysiertc material can be enhanced by metallic Le.-Amish and various polymeric fibers, and d ^ gl before pyrolysis uci ¹ Λ η, pressed -er matrix on the basis of the initial Zusarir; enp:.... -essens Irönneh products of different capital, uii ·: - l · '- " ¹ ■ .er. Can be formed. Examples can be chemically

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Resistant carbon-based building materials, such as pipes, bricks and the like, are made by mixing mixtures of the Powder, of carbon or graphite with the polymers according to of the invention with subsequent pyrolysis forms ,, presses or extruded. Other uses are in the manufacture of silicon carbide bodies that are manufactured by compressing powdered silicon with the polymers ir / suitable proportions, so that at the Kar ^ onisierung temperatures the body is converted into silicon carbide .. The above uses should be based on the following Description of the invention and the exemplary embodiments become even better understandable.

In describing the invention in greater detail, the polymer p-polyphenylene, wherein the phenylene rings are through the p-carbon atom are connected to each other, used to explain the rigid or stubborn polymeric substances that the invention form carbonaceous material. This material and its manufacturing process are known, described by Peter Kovacic and. Alexander Kyriakis in Journal of the American Chemical. Society, 85: 454 (1963). The polymer which is described according to this Process is obtained, is infusible and consists of benzene rings, which are connected to the p-positions. It contains only carbon-hydrogen in a weight ratio of 18: 1. In addition to its infusibility, the polymer is chemically inert with high thermal stability. This material as- ~ "o is referred to here as rigid. The polymer as it is from the

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Process of its manufacture, it is evident, represents a flaky brown powder, which has a very large surface area having. The polymers according to the invention are at pressures compressed by at least 70 kg / cm "". But iCs can too

pressures as high as 84.6 kg / cm can be used. It is clear that the pressure used to compact the powder affects the density of the final compacted mass. However, it is pointed out that solid, coherent masses which can be pyrolyzed can be achieved over the entire specified range. For various of the specified types of use, more strongly compressed masses - or, in other words, higher pressures - are desirable. The compression can be carried out by any of the usual procedures, including mechanical or isostatic methods, which, as such, do not belong to the scope of the present invention. The compression can take place at room temperature and results in a solid, tight body within the specified ranges. But the compression can also be done \ at higher temperatures. The compressed material has considerable lubricity so that removal from the mold is very easy. The p-polyphenylene, for example, shows a strength of up to 140 kg / cm in the compressed green state. In addition, X-ray diffraction studies show a high degree of anisotropy.

The compressed powder is then placed in an oven, whereby the compressed mass is pyrolyzed »During the

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In pyrolysis, hydrogen and other atoms are removed from the carbon present in the structure as volatile constituents, whereby a relatively pure carbonaceous mass remains. The material is kept at that temperature until pyrolysis of the entire mass occurs. The Py ^ Tolysetemperaturen can vary in the range from 650 to 2500 ⁰ C. The annealing or dwell time of the compressed mass in the temperature environment depends on the temperatures. However, it has been found that for practical purposes a residence time of 1 hour at the specified temperature ranges is sufficient to carry out the pyrolysis. . .

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1.68 g of p-polyphenylene polymer were poured into a steel mold given two stamps. The material was in a press case

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a pressure of 2356 kg / cm. The sample obtained was a band of 6.0 × 0.8 × 0.28 cm. The compressed bar was

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.then placed in a ceramic tube furnace with an electric Resistance was heated. The. The temperature of the furnace was 1000 ° C. The residence time of the ingot in an argon atmosphere in the Oven was 1 hour. After removal from the furnace, the rafter became checked and it was found that it had been completely pyrolysed.

Example 2 ■. .. ■ '

The above procedure was repeated using 0 _s ^! ! -8 g

2 p-polyphenyleno The pressing pressure was 8577 kg / cm. Instead of one

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Barrens 'a cylinder with the dimensions 1.2J cm diameter>: 0.305 cm length was produced' according to the mold used in the press device. The heating ^{temperature was 1000 °} C. with a residence time in the furnace of 1 hour. This sample was also kept in an argon atmosphere.

Example j) ■ '

The procedure of Example 2 was repeated, one of the same size Cylinder was made using the same amount of polymer. In the present example, however, a Pressing pressure of 703 kg / cm. I would be here again obtained a carbon-containing product according to the invention.

example

In order to explain the application of the products according to the invention, the gem'dss. Example 1 Ingots produced in a dry Λ -ellenbatterie used. A commercially available size D flashlight battery with a value of 1-1 / 2 volts was used. The carbon electrode in the dry cell was removed and replaced by the kiln from Example 1. The battery was then checked using a voltmeter and the output voltage of 1 1/2 volts was maintained «

Example 5

To the . To determine the effect of the pyrolysis temperature on the modulus of rupture, following the procedure of Example 1 were four

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Pattern made. Table 1 shows the results of the sample production in relation to the modulus of rupture. Of the The break test carried out was a three-point load test. It should be noted that the modulus is proportional to the condition temperature is. In all cases the residence time of the material was at the specified pyrolysis temperature 1 hour.

Table 1

Gexiicht pressure - size of the sample heating module of the (g) (kg / cm ² ) (cm) temperature rupture test

(° C) (kg / cmr)

1.75 * 2365 6.0 χ 0.8 χ .0.305

(Bars)

1.47 2365 6.0 χ 0/8 χ 0.25

(Bars)

1.67 2365 6.0 χ 0.8 χ 0.28

(Bars)

1.56 2365 6.0 χ 0.8 χ 0.28

The carbonaceous product resulting from the pyrolysis of the compressed polyphenylene material in the above examples ergabi was obtained by optical microscopy and by X-ray suction techniques analyzed. Optical microscopy showed that the pyrolyzed product had a layered structure, the so-called layers of carbonaceous material, so that the thermal and electrical conductivities ces pyrolyzed material were anisotropic. The structure of the Carboniferous materials within the> layers can cause

1000 436 870 309 760 231 650 176

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there will be through the. Choice of procedural conditions. For example, V7urde a microstructure ', which was that of graphite very similar to Table 2, achieved in that the polyphenylene at 5'620 kg / cm "" and pressed for 1 hour in argon at 1000 ° C

was heated. On the other hand, pressing at 70J gave kg / cm and heating to 1000 ° C, Table 2, a structure different from that of graphite. It is obvious to a person skilled in the art that through appropriate selection of the procedural conditions, at temperatures well below normal graphitization temperatures, a graphite product composed of graphite layers or that a product can be obtained achievable is the anisotropic electrical and thermal properties possesses, as they usually appeared, M graphite, and which is made up of carbon layers and at the same time the Has advantages of carbon, e.g. high hardness and processability at low temperature.

Table 2

"d" -spaces, 8

Graphite 1.68 2, o4 3, JJ

Pyrolysis polyphenylene.

(5620 kg / cm, 1000 C) 1.69 2.12 5.39

Py <rolyzed polyphenylene ■

(703 kg / cm, iooo ° c) 1.21 2.10 3A ^

One of the salient advantages of the material described here and its manufacturing process compared to common ones

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Graphite materials consists of other substances containing carbon Mass of the invention can be incorporated. In other words, the pyrolyzed polymers of the invention can serve as binders for = various other Ctoffe. As indicated above, virtually any material that is not influenced by the pyrolysis temperature can be added to the polymer incorporated during the compression process, will. Furthermore, the almost complete retention of the carbon present in the polyphenylene gives an unusual result high percentage yield of carbonaceous residue for a carbonation binder. The yield of carbonized Backlog is in the range between 84.94 and 87.18; '. With binders for a common application, the carbon yield from carbonization seldom exceeds 6 $ p. As the polyphenylene also does not melt or soften when the temperature is up is increased to a point where pyrolysis is complete ..- occurs for bodies made with polyphenylene as a binder have practically no softening, deformation or warping compared to the geometric shape into which they were originally pressed, eliminating the need for the Wrapping bodies in coke or otherwise during pyrolysis to support. As can be seen, the incorporated material mixed with the powdered polymer before pressing resulting in a homogeneous mixture, which is then the Is subjected to pyrolysis. As indicated above, the fillers in such a composition can be in the range of Metal borides, carbides and nitrides up to metallic,

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ceramic tmu 3or powders and fibers as well as powdered Koiilenctof. C. or move graphite. Listed below are some specific examples of composite masses made using four products according to the invention have been produced.

Example 6

A mixture was prepared from 2 g of ATJ graphite which passed through a 270 mm sieve, 0.1 g of boron powder which passed through a .m J525 mesh sieve, and 0.2 g of p-polyphenylene. After thorough mixing of the constituents, a cylinder was pressed which had a dimension of 1.27 cm in diameter χ 0.30.5 cm in length and had a weight of 1.40 g. The pressing pressure was 3520 kg / cm '". The compressed mass was then placed in an oven and heated for 1/2 hour at 1000 ° C. A dense, solidified body was obtained.

Example 7 ". *

A mixture was prepared from 2.25 g of zirconium boride in the form (J. of a 325P powder, 0.5 g of 600 grit silicon carbide, and 2.11 g p-polyphenylene. The one used to compress the mixture

2
The pressing pressure was 7030 kg / cm. It xmirde a Z5 ^r relieving of 1 * 27 CSS Dia-isser χ ^ S 0.5 cm length made "with a G-eWicht of. Ί 1.71 g. Γ-er viurde compressed cylinder in a furnace brought to 1 hour heated for a long time at 1000 ° C. The pyrolysed end product VfU- de then exposed to an oxyacetylene burner flame and showed excellent resistance to oxidation.

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. Example 8

A mixture was made from 4 g of ATJ graphite with a Particle size of -270 mesh, 0.75 g of iridium powder with a particle size of -80 mesh and 1.2 g of p-polyphenylene.

The mixture was then put under a pressure of 7030 kg / cm

subjected to form a cylinder 1.5 cm in diameter and 3 * 3 cm length; the cylinder weighed 0.83 g · the compressed ^ Mass was then placed in an oven and left on for 1 hour

Heated to 1000 ° C. The same process steps and components were used to make another sexton, but using a heating temperature in the oven of 24-00 ° C for 1 hour. Both samples produced showed V / resistance- ■■■ - ■; "· ability to. Oxidation in the presence of an oxyacetylene burner flame *

Example 9

A mixture consisting of 0.75 g ATJ graphite powder passed through a 270 mesh sieve, 0.005 g boron fibers 0.13 mm in diameter chopped to lengths from 6.35 mm to 3.18 mm, and 0 , 2 g of polyphenylene powder, was pressed into a cylinder 1.27 cm in diameter and 0.305 cm in height, weighing 0.66 g. This was heated to 1000 C for 1 hour in an argon atmosphere. A solidification into a hard, compact fiber-reinforced body was achieved. There was no discernible physical or chemical effect between the boron fibers and. the pyroIytic. Residue or volatile products found.

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As can be seen from the preceding examples, composite fabrics can be made using the pyrolytic

It should be noted that the amount of binder present, as well as the filler material used, will depend on the end result desired. It has been shown in the examples, may serve as a binder for various types of small amounts of polyphenylene to the press accessories and masses of the invention herzustel- m len. As little as 2% by weight of polyphenylene can be used to form these compound substances.

It is evident that the particle size of the particulate fillers and the diameters of the reinforcing fibers do not. have a significant influence on the solidification of these composite masses by pressing and heating, as long as the amount of polyphenylene is sufficient to fill the cavities between the particles or fibers Fillers or fibers are formerly compatible with hydrogen and carbon up to the Pyro'lyse temperature, one of the most promising areas in the application of the invention consists in the formation of compounds jtarch actual former reaction of the pyrolysed product with a filler * This was shown when Silieiua before was incorporated into the compressing the powder during heating ß-SilisJLumea / was r- ,, hiü erzeilfc, ms following specific example; the formation of the silicon alloy Sj,

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Example · IQ

3.4 g of silicon having a size of -325 mesh and 2 g of p-polyphenylene were mixed thoroughly. The mixture was subjected to a pressing pressure of 84/5 kg / cm, a cylinder measuring 1j , 27 cm in diameter χ 0.4 cm in length being formed. The compressed cylinder weighed ö> 87 g. This cylinder was then subjected to a heating temperature of 1400 ° C. The product obtained was β-silicon carfoid as determined by X-ray diffraction experiments.

Although the invention has been described and illustrated in detail the examples do not represent any limitation of the invention The scope of the invention is only through the appended Patent rights limited.

- patent claims -

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Claims (10)

1S46790 - 15 - "K 425 patent claims-: 1. Pyrolyzed densified polycarbocyciisohe. Connection, characterized in that the phenyl and naphthy! Rings are directly connected to one another. ., _: 2.- Compressed connection according to claim Ij, characterized in that that the polycarbocyclic compound with solid in one piece Filler "is mixed. p. Verdichteta compound according to claim 2, characterized -NET gekennzeich ^1., P ^ ljearbocyclische compound cass at least 2 wt ;. ' which has a mixture of filling material " ; A. Compacted connection according to claim 1, 2 or 5, characterized characterized in that the po ^ carbocyclic compound is polyphenylene is. ,: 5 «Process for the production of a novel * carbonaceous fcf ^ .. «lfa. ^ rf _w g ^ .... -n. ... _n " BATH ORIGINAL ; ■ - ιβ - n 425; Materials, characterized in that one has a solid, single-part, polyearboeyelisehe compound in which the phenyl and Naphthyl rings are directly connected to each other, compressed into a solid coherent mass and the compressed Connection then pyrolyzed. '- ■ - ■ 6. The method according to claim 5, characterized in that when compressing a pressure of at least 70 kg / cm · ■ used. 7. The method according to claim 5 or 6, characterized in that that one uses polyphenylene as a polyearboeyelisehe compound. 8. The method according to claim 5 to 7, characterized in that that solid, individual filler material is mixed with the polycarbocyclic compound prior to compression. ', 9 · The method according to claim 8, characterized in that one used as filler material silicon. 10. .The method according to claim 9, characterized in that "one stoichiometric amounts of a polycarboeyclic compound and of silicon mixed together. 109833/0403 BATH ORIGINAL