DE2546413A1 - INJECTABLE SWELLING FASTENER - Google Patents

Description

IBERLlN 33 8 MUNICH

Auguste-Viktoria-StraBeS » _n RIIOrHKFAPARTNFR PtenzenauerstraBe2

Pat-Anw. Dr. Ing. Ruschke Ul ". KUbUHIVt & ΓΑΚ I NtK Pat.-Anw.Dipl.-ing.

Pat. Dipl.-fng. PATCNTAMWSl TF ^{Hans E} " ^Ruechke

Olaf Ruschke Γ ft I C Ν I Λ IN VV η L I C 9803 24

Teiefon; 030 / £ gjg§f BERLIN - MÖNCHEN «/ eitaes

Telegram address: Telegwmm-Adre «» .:

Quadrature Beriin Quadrature Munich TELEX: Ϊ83786 TELEX: 522767

36 32

Minnesota Mining and Manufacturing Company, St. Paul "Minn"

V ₀ at »A,

Injectable swelling fastening material

The present invention relates to a composition which is useful to define v ^ n objects in üehälx'n and in particular to placing of catalyst supports in the housings of canisters, which are used as part of the exhaust systems of motor vehicles «Primarily, the invention relates to malleable masses with swelling particles that expand in situ to form a catalyst * - supports to be fixed in the canister housing.

is now recognized that one catalytic devices needs to air pollution to vern.inderri by the exhaust gases of motor vehicles, firstly to oxidize carbon monoxide and hydrocarbons, and secondly, to reduce nitrogen oxides ,, due to the required for this Keaktionen relatively high temperatures, the catalyst substrate must have relatively high temperatures and repeated thermal shocks

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and can also withstand mechanical vibrations «, ceramics Catalyst supports are excellent for such substrates Suitable as large surface areas for heterogeneous catalysis Required are ceramic substrates such as those of the US Pat RE 2? Ο747 desired.

Ceramic bodies are by their nature quite brittle and have coefficients of thermal expansion, which differ considerably from those of metals such as, for example, “. The way in which the ceramic body contained in the canister as a catalyst carrier is attached is of fundamental importance for the success of such catalytic arrangements; Shocks and vibrations cause mechanical shock loads, the cyclic thermal processes cause heat shock loads _e Both mechanical and thermal shock loads can lead to considerable wear and tear on the ceramic catalyst carrier; Since this wear and tear progresses faster and faster over time, the catalytic device quickly becomes unusable O

As the operation of the engine continues to fluctuate in the catalytic Causes reactions and the composition of the exhaust gases from the engine has an influence on the life of the catalytic converter, it must be possible to renew the catalyst body without also Replacing the metal case ”, consequently, is a simple one and convenient method of fixing the catalyst coated Substrates or supports very desirable,

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It is an object of the present invention to be a simple method to specify a substrate coated with a catalyst in a housing or other container, Es Another object is to provide a composition for securing a substrate coated with a catalyst in a container. Other goals result from the following description «,

In accordance with these and other objects of the present invention, it has been found to be a very desirable process to fix catalyst supports in containers consists in placing a swelling agent in the space between the supports and injecting the container and then letting it expand in situ. In particular, it is the swelling agent according to the invention, which has been found to be particularly useful, to an injectable plastic compound that has a swelling Flake material, an inorganic binder and a liquid Contain carrier and, if necessary, a plasticizer and / or fiber materials and fillers Compounds according to the invention preferably have a window putty-like consistency, but can also be thicker or thinner as desired be.

The swelling injectable mass according to the invention can; with advantage as mounting material, for example, _e in catalytic converters for automotive exhaust systems use. With this use, a lot of the putty-like mass is in the space between the

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injected ceramic catalyst carrier and the inner wall of the housing. This space is preferably not too large, since the expansion of large quantities of the swelling material can lead to the breakage of the relatively fragile ceramic pieces. The material can be introduced by flowing in or by injection under pressure; however, introduction under pressure is preferred since it ensures that the cavities are filled. After drying, in order to remove the volatile carrier liquid from the fastening material, the entire canister arrangement is carefully heated to expand the corrugated component of the fastening compound. The swollen compound holds the ceramic core structure in the canister. The elasticity of the compound The swelling compensates for differences in thermal expansion between the metal housing and the ceramic substrate and dampens the vibrations transmitted to the fragile structure by mechanical shaking movements. which prevents the bypassing of the catalyst, and isolates the ceramic catalyst carrier thermally against the housing _o a further advantage of the compositions according to the present invention is their insulating value of a temperature difference of 2oo to 35o C over a thickness of 1 cm allowed

The swelling fastener material of the present invention is useful and effective in that it is easy to use and very effective in solving the problems that the

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thermal and mechanical shock loads raise, which are exposed to such devices "£ '> s is to create cheap and can be used to define irregularly shaped or varying in size catalyst support. If desired, several catalyst carriers can also be fixed at the same time. Furthermore, it is largely superior to other fastening methods, in particular with regard to ease of use, low costs and the variety of possible uses -PS 3ob92 _e 477, which is not nux ¹ expensive and difficult to use, but is also gas-permeable and therefore offers no help in preventing the emergence of harmful gases.

The swellable constituent of the injectable swelling masses according to the present invention are unswollen and usually enriched or concentrated blocks of vermiculite or equivalent materials such as iiydx * obäotit or coarse, water-swelling mica of the tetrasilicate fluorine type i, "tetrasilicic fluorine"), such as described in U.S. Patent 3oOo1 _o 571, employed, to about 3o to about 80 wt .-% Peststoffanteil to this swelling ingredients verwendet.Vermiculit, hydrobiotite or tetra silicate mica ( "tetrasilicic mica") separately or in SiCN as a combination of two or three of these substances in the wet list _Q In general, unswollen vermiculite is preferred because it is cheap and easily available.

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Änordganische binders are from about 1o to about 5o wt, -% Peststoffanteil used in the preparation of the swelling material as claimed aer present invention "such Binaemittel are, for example micro-flakes of jvunstglimraer (according to US-PS 3 oo _e 1,571).". to a small particle size in aqueous suspension of ground and swollen to give a paste vermiculite, hontmorillonit (bentonite, hectorite or saponite), Kalonit (Kogelton) OAER low-melting glass "As can be seen, the mica can serve a dual purpose ₀

A sufficient amount of a volatile carrier liquid - preferably water - is used to give the mass a workable consistency. The exact amount used depends on the properties of the solids used 70 % of the weight of the dry material is sufficient to produce a mass that is soft enough for processing and injection, but does not contain so much water that it is difficult to dry % of the total amount of the carrier liquid of a water-compatible plasticizer may be required - e.g. glycerine, methyl cellulose, corn syrup or molasses. 'One fiber substance to ο up to about 25 of the dry weight at _o Here “it can be, for example, chrysolite or hornblende asbestos, glass fibers of different composition, which under different

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Trade names are available (such as linear spun fibers bspwo glass wool and blown fibers - for example, "" Kaowool ") temperature resistant threads (crystalline alumina fibers), or metal filaments hand, a preferable to add both straight and blown fibers in combination improve a _c i ^ hese fiber materials the cohesion of the swellable fastening material. It may be necessary to refrain from using asbestos, as this material can be harmful to health, although asbestos fibers are cheaper than others. With fiberglass materials or temperature-resistant (glass-like or crystalline) threads or "whiskers", a useful reinforcement of the final fastening compound can be achieved _o

Furthermore, fillers such as magnesia, clay, silica or ground but not pulped, coarse, exfoliated swellable material are added in an amount of from ο to about 40 % of the dry weight in order to change the properties of the final fastening material - e.g. to reduce the expansion forces that occur when the fastening material swells «,

The "procedures in preparing the ingredients is not." critical In general, the swellable material, the binder and, if necessary, the plasticizer are thoroughly mixed with a sufficient amount Mix the amount of liquid carrier - for example “water” - to form a putty-like mass. Should the mass be a fiber material usually use excess water for

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Formation of a slurry, which is concentrated by filtering to a water content of about 15 to 20 wt the filter cake with water and ggff _β the plasticizer, in order to form the composition into a syringeable composition, which appears in their consistency as modeling clay or & itt. the injectable composition is, for example, _e with a pressure gun or by hand into the space between the fragile and rigid parts The arrangement is pressed in ». By carefully heating the arrangement with the swellable mass in it, it is first dried and expanded or swelled at around 300 to 65o ° G, creating a thermally resistant, elastic, but nevertheless robust and permanent attachment for the system forms »

The properties - such as the bond strength, the fastening or expansion force and the elasticity - depend on the composition of the mass and the dimensions of the fastening-s The speed and extent of expansion of the swelling mixture depend on the heating rate, the applied retention forces and the composition ₀ The higher the proportion of the swelling material in the composition, the higher the volume percentage expansion _β The higher the heating rate and / or the lower the retention forces, the greater the volume percentage expansion - of course within certain limits of usually around 25o volume- '

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percentage ^ s at this point it is important to visualize that the forces occurring during the expansion of the swelling material can be so high that the ceramic substrate is crushed Hence one must consider the size of the space between the pay some attention to the ceramic substrate and the housing, when choosing the composition of the swellable material Smaller gaps should not be filled with a mass that with the l'esten without back contents a very none volume percentage Showed expansion

The integrity of the attachment is checked with a hot shake test ("hot-shake test") ο - ^ he test arrangement consists of one mechanical shaker and a hot gas source

A cylindrical, coated with the catalyst is used ceramic substrate with an outside diameter of 11.3 cm and 7.6 cm long into a round metal case with an inner diameter of 12.4 cm and a length of 8.9 cm with a A steel end ring that is 1.6 mm thick and 9.5 mm wide and has an outside diameter of slightly less than 12.33 cm and is welded into the end of the canister around the catalyst carrier to hold, which he centers in the housing and carries »i) he The catalyst used can be any conventional catalyst - for example platinum, platinum and palladium or copper, cobalt, chromium or vanadium with catalysts for oxidation, reduction or other catalytic reactions with the constituents of the ab-, Exhaust or reactive gases passing through the carrier

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- 1ο -

durchströmmerio Lie swellable composition according to the present invention Invention (or the one to be tested) is in the king room between The inner wall of the housing and the outer wall of the ceramic substrate are then welded into the opposite one A second ring at the end of the canister to hold the ceramic substrate in place and the swellable mass expands Metal closure ring contacts the face of the ceramic substrate, but the inner wall of the housing is not in direct contact Touching the outer surface of the substrate »

The mechanical shaker is an air piston vibrator (Model 12oo VMS from ia, Cleveland Vibrator Oo ■ „) with a device that holds the canister horizontally (~ est ä) or vertical (test B) holds «, In test B the shaker is on four 2.5 x 15 cm elastic bands suspended from a rigid frame The unit operated with about 4.22 kg / cm of air pressure generates an average acceleration of about 30 g at one frequency of 55 Hz, the peak acceleration being 100 g The deflection when swinging is about 3

The hot gas source is essentially a propane burner which is connected to the canister inlet via metal hoses. Lie flanme is supplied with a gas mixture of 793 liters / ötd. Propane and 16 / joo liters / hr, "air at normal temperature and ignited iMormaldruck" after the catalyst substrate has been warmed up (after about 3 min _0), passing secondary air to 85oo liters / STDO before the access to the catalyst substrate

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to oxidize in the Abgasstrorn a to the residual propane in the catalyst zone ,, The! emperature of the catalyst substrate gases leaving is determined with a thermocouple arrangement and varies between 600 and 7oo C ₀ is a xemperatur of about 600 ⁰ C is reached, it switches the shaker with an air pressure of 6twa 4.22 kg / cm in "the relative movement between the container and the core is observed by means of a device" Strobotac "of Pa ₀ General radio Corp _o the service life of attachment is the time from the start of shaking up to The time elapses when the core has been pushed 1.5 mm out of the canister's end ring. "The hot shake test is used as a convenient test for extremely high acceleration. At the moment there are no documents with which the test duration on a hot shaking test facility can be equated with the mileage during normal driving. Tests A and B do not result necessarily in identical canisters also identical .Ergebnisse, and the purpose of the test is more of a comparison, but can hardly results expected, be in proportion with the in real driving operation displayed! Efficiency _β Thus packs made of wire gauze is quite durable due to the elasticity of the wire, but can fail for other reasons.

Tests on ceramic honeycomb structures with expanded injectable yuell masses in canisters show that the attachment is much more durable than if you just pour a dry swellable material and then let it swell _o Attachments made of dry vermiculite according to US-PS 1 _O 912,544 build extremely quickly.

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- sometimes in less than five minutes - from.

Having thus generally described the invention, this will now be illustrated by the following examples of the type and V / else meet, is being held for the invention than the applicable best ₀

Example I.

Exfoliated vermiculite with a mean diameter of 0.8 to 1.2 mm (6o g) was placed in a large Waring blender to 2ooo ml of water and about 1o g min ₀ stirred at high speed to form a homogeneous dispersion of glass fiber material 5 ( "fiberglass" Fa ₀ Johns Manville Co _0, type JM 1o6) and 15 g of glass fiber material ( "Kaowoöl" from ₀ Babcock and Wilcox) were added and thoroughly mixed and then vermiculite ore, d _o h _o unaufgeblättertes vermiculite (I8o g of the product Zonolite No ₀ 4 from Fa ₀ W ₀ R ₀ Grace and Co ₀ , sieved particles of about 0.1 to 0.5 mm), bentonite (40 g as Bentolite H from Fa ₀ Georgia Kaiin Co ₀ ) and 20 ml of a 1% strength solution of partially hydrolyzed polyacrylamide ( "Separan NP-Io Fa ₀ Dow Chemical Company) was added as a flocculating agent and thoroughly mixed in. the resulting mixture was filtered in a large Buchner funnel through filter paper of the standard type No. ₀ 4 and the filter cake again with a blade mixer ( fa brikat Sigma) kneaded with a 2% aqueous methyl cellulose solution to form a plastic swellable composition according to the invention, which contained 50 % water and 50 % solids.

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This plastic mass was poured into a conventional sealing gun and placed in the approximately 3 now wide ring space between a circular cylindrical ceramic catalyst carrier in a honeycomb structure and a cylindrical housing with a retaining ring at one end, as described above.The gap volume of 89 ml requires 55 g (dry weight) of the swellable composition until it was completely filled ", then a metal holder was welded into the other end and the arrangement was heated to 600 ° C. for two hours, the swellable mass expanding and filling the annular space under pressure." The entire arrangement was in a horizontal position mounted and connected via tubing to an exhaust simulator, wherein the vibrations at right angles to the gas flow were carried out (test a), as described above ,, the system was made after 45 min of _o ©

A corresponding system with a dry mix was used for comparison of 60 g vermiculite ore (0.1 to 0.5 mm), 20 g defoliated vermiculite (0.8 to 1.2 mm) and 20 g bentonite as packing material in the annular space between the ceramic honeycomb structure and A portion of the above mixture (58 g) was carefully packed into the annulus (89 ml) and onto the housing a sealing ring welded on, the entire arrangement two hours heated to 600 U for a long time and then into the exhaust gas simulator as above Under essentially the same conditions as above, this system failed after two minutes «

Further tests were carried out with the proportions listed in the following ■ ■

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-H-

Table are given, and according to the procedure outlined above. Results of 35 minutes and less in the hot shake test indicate usefulness for many applications which do not experience excessive vibrations.

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Example.) Mon. 2 3 4 5 6 2 8 9. \ o

Solids

Total weight 3oo 3oo 3oo 3oo 32o 3oo 3oo 32o 3oo

yuell component (%) 6o 6o 6o 8o 47 33 6o 56 6o

Vermiculite (a) (g) 18o 18o 18o 24o 15o 1oo 18ο 18o 18o

Binder (%) '13 .3 ο 6 _β 7 2o 25 13 »3 13o3 12.5 13.3

Bentonite Cg) 4o -. 2o 6o 8o - 4.0 40 4o

13.3
4o O 2o 2o
60 25th
80 2o
60 26 ₀ 7
80 2o
60 O 25th
80

Fillers (%) 2o 26 _O 7 2o 0 25 4o 2o 13o3 2o Vermiculite (b) (g) 60 80 60 -—- 80 80 60 4o 60 cn Magnesia (g) —-- - <—— - ~ - .- 4o --—

S straight fibers (%) 1.7 1.7 1.7 0 3 1.7 1.7 1.6 6.7

O ₀ fiberglass Cg) 5 5 5 1o 5 5 5 5

_v Inorganic (c) (g) ^ non-straight fibers (%) _o "Kaowool ^ grägerlö solvent

^M water

5
15th 11.7
35 11.7
35 O O 11.7
35 5
15th 18 "3
55 10
O IV) 3 3 2 IV) 1I2
2oo 2o5 2 2oo 2oo 2oo 23o 25th 2oo
25o 2oo ! I.
IV) 1 I.
VJl! I. 2o 2o

^ω ethanol '(I)

Plasticizers ,

Methyl cellulose (d) (cm ^) glycerine

Flocculants

Separan Ce) ^^ - ^ --— - - · Js ₀

Hot shake test (min) 39o "143 35o 175 35 I06 15o 357 80 ^ ¹

(a) unswollen vermiculite 0.2 to 0.5 mm except 0.2 to 0.8 mm in example 4. ⁰ ^

(b) flaked, vermiculite ⁴ ^ "

(c) US Pat. No. 3,795 »524 _ω

(d) as a 2% solution

(e) as a 1% solution "Still functional when the test is aborted

Claims (1)

Claims ^: 1 ο Kneaded mass, which can be filled between the object and a container in which it is to be set, and expanded between the object and container, characterized in that the mass is about 3o to about 50 % swellable material and at least ο to about Contains 3o % of an inorganic binder or ο to about 4o % of a filler or both binder and filler in the specified amounts, in each case dry weight percent, with a carrier liquid also being present in an amount of 10 to about 55% of the weight of the combination, 2 ₀ mass according to claim 1, characterized by 5 to about 2b dry weight percent of a fibrous inorganic filler " 3o mass according to claim 1, characterized by a plasticizer component from 0.5 to 1o percent by volume compared to the total amount of carrier liquid 4o mass according to claim 1, characterized in that the swellable material is non-exfoliated vermiculite a particle size of about 0.1 to about 2 mm. 5ο method for setting a ceramic catalyst substrate in a container, characterized in that a kneaded mass of a carrier liquid and solids, which - in proportions of the dry weight - about 3o to about 8o % swellable material with a particle size of 0.1 up to about 2 mm as well 609818/0983 at least ο up to about 3c % of an inorganic! binder or ο up to about 40 % of a filler or the binder and the filler in the specified amounts in a wenge H
introduces sufficient to fill the cavity between αem substrate and the container substantially by continuing to dry the kneading mass to remove volatile constituents of the carrier liquid, and then expanding the swellable material in situ 6ο method according to claim 5, characterized in that aas The swellable material is expanded by heating to a Temperature of more than about 300 ° above sea level takes place » 7. Method according to.-Claim 6, characterized in that maxi uses nicut-exfoliated vermiculite as the swellable material and heated ^{at 300 to ObO 0 C.} 8 “Canister with a .catalyst for the catalytic conversion of one or more components of gases, with a housing, and a catalyst carrier inside the housing, which has the! about 8o 70 swellable material mm in a particle size of o, 1 to about 2 and at least ο to about 3o% of an inorganic binder or at least ο to about 4o% of a filler, or both the binder also contains the filler in the amounts indicated, wherein the expanded swellable mass the catalyst carrier in the housing in ■ ' 609818/0983 Position brings una determined and a movement of the Zatalysato: carrier relative to the housing prevented » Cl / Se 609818/098 3