DE4007060A1 - Intumescent sheet useful in construction and as moulding material - is made from fibres and expandable graphite by paper process without binder - Google Patents

Abstract

Intumescent sheet, produced by a paper and board process, consists of a mixt. of fibres and expandable graphite. Pref. the sheet is produced by a water-based wet process. Pref. the graphite consists of SOx- and/or Nox-expanded graphite flakes with an average dia. of 0.1-5 mm and is used in an amt. of 1-98 wt.%. Cellulose and opt. other fibres, pref. glass and/or mineral fibres, are used. USE/ADVANTAGE - The sheet is claimed for use in 3D moulded form; as construction element for protection against fire; and as lightweight material produced by expanding the sheet. It can be made very easily, without using binders. In an example 5 g bleached hardwood pulp were dispersed in 1 l water and 50 g blown graphite (NOx-type) were stirred in. The suspension was made into a 22 cm square sheet on a wire mesh covered with filter paper. After removing from the wire mesh, the sheet was covered with filter paper and the sandwich was pressed to remove nearly all water. A flexible, dimensionally stable sheet was obtd., which was easy to handle. If the wet or dry sheet was exposed to a Bunsen flame, it expanded considerably in the area of the flame.

Description

The present invention relates to intumescence rende, d. H. with flaming expanding, cardboard or paper-like fabrics, consisting of paper capable fiber material and proportions from 1 to approx. 98% by weight expanded graphite, based on the total weight of the fabric.

Paper becomes on sheet formers or paper machines mostly in the aqueous process, sometimes in the case of poly olefin fibers also by water-free depositing of spinnfa star and then rolling, if necessary under Auf heat, manufactured.

Papers can be made from natural organic and inorganic fibers or mixtures thereof are produced, such as e.g. B. cellulose fibers or asbestos, calcium sulfate or Titanate fibers or synthetic fibers, such as. B. Polyacrylonitrile fibers, polyester fibers, polyamide fibers aliphatic or aromatic types, polyolefin fibers, but also glass fibers, kaolin fibers, aluminum oxide fibers or their mixtures.  

Albeit from all these fiber types or their mixtures Papers available are papers based on Cel loose fibers or glass fine fibers and if necessary Gypsum fibers are particularly well known. Most often contain papers, at least partially, cellulose fibers.

Paper manufacture mainly uses the aqueous one Process in which the fibers are made from aqueous slurry are placed on sieves to form fabrics.

As expanded graphite such modified graphites are understood to expand when heated to 150 to 600 ° C. Mostly, these are reaction products of graphite with fuming nitric or sulfuric acid. The blowing process of such expanded graphite is effected by expansion of the SO _x or NO _x stored in the interstitial planes. However, other blowing agents can also cause expansion of the expanded graphites, e.g. B. Halogens.

The expanded graphites are mainly in the form of powders before, whose particles consist of scales, that is flat are. Such dandruff have good swellability, though they average surface diameters from 0.1 to 5 mm, preferably 0.2 to 2 mm.

It is known to expandable graphite for fire protection purposes to use, for example as a powder or in polymers and Foam incorporated or as a coating on one Carrier material, with z. B. Polychloroprene resins be used, however, due to their Halogenge are considered to be of concern. Basically is  strive to use organic binders in applications of To minimize expanded graphite for fire protection purposes; anorga African systems such as B. water glass as a binder seem unsuitable due to their brittleness; quasi smoke-free, flexible materials with intumescence ability is therefore lacking.

It has now surprisingly been found that when exposed to flames, expanding fabrics on very simple way without the necessary use of binders can get if you in the process of papermaking lung, be it non-aqueous or preferably aqueous working processes, a mixture of fibers or fiber mix and expandable graphite.

This works surprisingly well using the aqueous process on usual sheet formers or paper machines or Cardboard machines if you have cellulosic fibers or fiber mixtures containing such fibers in admixture with Expandable graphite flake powder is used, the mixture made of expanded graphite and fibers surprisingly little too different tended sedimentation, but regardless of Differences in density connected relatively homogeneously remains.

Here can be obtained without further fabric those who have good cohesion and only 50 to 2% fibers, preferably 25 to 5% cellulose fibers hold. The content of expandable graphite is for example 50 to 98% of the total weight of the area educate. Of course, there are also papers and cardboards with bloat  graphite content from under 50 down to about 5 or even 1% possible and desired if necessary.

Here is the use of binders, retention with agents, sizing or dispersion aids and fillers fabrics in the form of scales, platelets, fibers, spheres or powders quite possible, e.g. B. to achieve special strength, hardness or moisture resistance speed, but not necessary.

Papers or cardboards produced in this way can be found in ge dried state thicknesses of, for example, 0.1 to 5 and have more millimeters and so in terms of their Expansion capacity to meet the needs of the Fire protection can be adjusted.

Accordingly, the present invention relates to:

In the case of flaming, expandable fabrics, thereby characterized in that in the process of papermaking Mixtures of fibers and expanded graphite are used;

• - In particular, that mixtures of fibers and expanded graphite in the aqueous papermaking process begins;
• - In particular, that cellulosic Fa ser or fiber mixtures, the cellulosic fibers included, used;  
• - In particular, that it is scaled as expanded graphite material with mean surface diameters of 0.1 to 5 mm used;
• - In particular, that such ver applies the glass fibers and / or mineral fibers son included type;
• - in particular that the fabrics are 1 to 98%, preferably 5 to 95% by weight, consist of expandable graphite,
• - as well as flat, intumescent, d. H. at Be expanding fire protection material Basis of the above procedure or fire protective devices containing this material.

Within the scope of the invention, such as flat structures according to the basic methods of paper production Manufactured structures understood the flat character have and resemble papers, cardboards or boxes. It can are flat structures, but also products that are comparable to corrugated cardboard, egg cartons, pods or honeycomb u. Ä. They can be constructed in one layer or multi-layered and also the character of sandwiches or have exchanged papers. Of course you can also coated, lacquered, laminated, impregnated, dyed, glued, bound or otherwise be treated. You can also look like plywood too Layer forms can be connected or part of Be laminates or in the manufacture or after sluggish in wet or dry condition too special  Shaped bodies, such as half shells, housings and. shaped who the. Also the deformation of the damp or dry Ge form by heat and / or pressure is with or without help of binders to consider.

The products of the invention can also be added subsequently or in the production of profiles, hollow bodies or spe target shaped fabrics are deformed, as well Adhesive layers, protective layers or imprints on one side, have multiple pages or a pattern. By combination with woods, papers, cardboards, foils, profiles, sheets, Wires, fibers and their processing forms can also reinforced structures according to the invention can be obtained.

The expansion can be brought about by heating the mostly flat structures according to the invention to temperatures above 150 ° C. By expansion with the shaping of the possibly preformed flat structures according to the invention, for example, lightweight moldings with densities between about 80 and 800, preferably 100 and 500 kg / m ³ can be produced. Expansion temperatures between 200 and 650 ° C are preferred, as are largely closed forms. The invention thus also relates to lightweight sol bodies.

Such flat structures are mostly not or too there are also pre-expanded or partially expanded Zu used for fire protection purposes. The fire Protection essentially consists in the fact that the expansion of the used ones Bands, plates, half-shells or other semi-finished products  the flat structures according to the invention possibly existing or joints, cracks, cavities or fire Openings for flames and flame gases ver closes, or by forming insulating layers and Closures prevent further heat entry. By beson whose advantage is that the Ge according to the invention make almost no smoke.

Special applications would be e.g. B. Deposits for firsts cable bulkheads or to secure cavities men; Protective plates made of a sandwich structure or Plywood-like structure from the surfaces according to the invention chengebilden and wire mesh and / or mineral fiber mat exist; flat, honeycomb or corrugated or egg-box-shaped inserts for safes and Fire doors made of wood, steel or laminates; ge if necessary self-adhesive and / or metal, textile, fu Laminated sealing and insulating strips for Fire doors, cable jackets, cable bulkheads, exhaust fans were etc. or components such. B. rolled plugs for thermally responsive closure devices for venting tion elements, climate shafts, fume cupboards, pipe sleeves for Squeezing metal and especially plastic lead in the event of fire or construction elements for ther actuation of switches, valves or Signals.

The inventive, preferably after the aqueous Paper making processes - d. H. from aqueous dis persion of the ingredients on a kind of sieve are stored - contain manufactured fabrics  1 to 98% by weight expanded graphite, preferably 5 to 95, ins particularly 15 to 85% by weight. They contain 2.0 to 99% by weight, preferably 5 to 95% by weight, especially before adds 10 to 85 wt .-% fiber material.

The fiber material is preferably cellu Loose fiber material, be it from waste paper, wood ground, bleached or unbleached, from needle or Hardwoods, straw, pulp, regenerated pulp, Cotton, other natural or partially or fully syn synthetic fibers. But there are also, especially in Combination with each other and / or with cellulosic Fibers, all organic or preferably anorga natural fibers and technology, be it z. B. polyolefin fibers, polyacrylic fibers, poly ester fibers, polyamide fibers aliphatic or aromatic shear types, polyurethane fibers, polyimide fibers, metal fibers, ceramic fibers based on chamotte, Ge stones, basalts, kaolin, aluminum oxide, glass of ver various types, asbestos, gypsum, titanate, carbide fibers or nitride fibers and C fibers.

Such fibers also preferably come out as mixtures Cellulose and glass fibers, being considered, in a mixture also all accessible length / diameter ratios in Are to be considered, including fibers with extreme ge ring diameter or relatively short length.

The transition to the fillers, which can also be used if necessary, is fluid here. Such fillers can be in the form of crystals, fibers, leaves, dumbbells, dumbbells (hollow) balls, powders or flakes and are mostly mineral in nature, e.g. B. ashes, glass, kaolin, enamel frits, chalk, gypsum, talcum, mica, coal, metal oxides, calcium silicates, phosphates and polyphosphates, such as NH ₄ polyphosphate, ethylenediamine phosphate, calcium phosphates and others, borates, graphite or paint pigments.

But there are also pentaerythritol, melamine, wood flour, Starch, polymer powder, powdered sugar residues or making cellulose or processing fruit into consideration.

The fillers can optionally also be intumescent Have properties, such as perlite or vermiculite, they can be water of crystallization or hy have hydroxyl groups, or water of hydration, such as Gypsum hydrate, Al hydroxide, Mg hydroxide, Ettringite or optionally hydrated alkali silicates.

In addition to expanded graphite and the fiber content, the inventions fabric according to the invention 0 to 80, preferably 0 to Contain 55% by weight of such fillers.

Naturally, the use of auxiliary means is Paper industry, such as sizing agents, retention agents, Wet strength agents, dyes, biocides, dispersants etc. to consider.

Although it can easily be dispensed with, is it is quite possible for special purposes, even dissolved, dis  Pearled or emulsified binders, be they art fabric latices, formaldehyde resins, rosins, alka lisilicates, binders based on modified cellulo starches, molasses, sugar or protein or optionally water-soluble phosphates, Bora silicates for the purpose of additional fire protection effects.

For example, the use of phosphates and phosphonates of ammonia or amines such as ethylenedi amine, urea or melamine, or of metals 1st-3rd Main group of particular interest because this ver the willingness to oxidize the expandable graphite are able to reduce.

Of course, the fabrics according to the invention even after the actual manufacturing process, e.g. B. by Impregnation, soaking, spraying, coating with one Many of the aids mentioned are equipped, for example, if you still have a water repellent or want to achieve phosphate finishing.

It is also of interest to start with the manufacturing process zeß as an insert, overlay or underlay a fleece, fabric or To use knitted or scrim, be it a rigid one or flexible material, which is then an integral part part of the fabric according to the invention and this if necessary additional deformability, dimensional dimension stability, mechanical resistance or rigidity or tensile strength.  

Those according to the invention are of particular interest Flat structures which (whether in the form of preferably Fa sern, from z. B. flakes, balls or hollow balls and pul vern) contain 20 to 80 wt .-% glass, since they are good Ability to produce particularly little smoke and combustion gases containing constituents.

The following examples are intended to illustrate the subject matter of the invention explain, but not limit. The specified parts are parts and percentages by weight, unless otherwise it is said.  

example 1

5 g of bleached hardwood paper stock were dispersed in 1 l of water and stirred well with 50 g of expanded graphite (NO _x type 9550250, Posehl Erzkontor). The suspension was then placed on a sheet former, square, edge length 22 cm, and suctioned off to form a stable sheet, a filter paper being selected as the base on the sieve. After removal from the screen, the top of the sheet formed was also covered with filter paper. Then the resulting sandwich was pressed between two felt mats on the press with the water portion largely removed.

A flexible, dimensionally stable sheet was obtained which was good was manageable. This sheet was made damp state or in the dried state of a bunsen exposed to burner flame, causing significant expansion occurred in the flame area.

Example 2

In 1 l of water, 5 parts of softwood pulp were bleached, suspended and formed into a sheet on the sheet former used in Example 1. A suspension of 100 parts of Sigraflex A expanded graphite (SO _x type) and 15 parts of softwood paper stock was then added to this sheet and, after the sheet had formed, another suspension of 5 parts of softwood paper stock in approx. 1 liter of water. In this way, a sandwich was formed in the sheet former, the approx. 2 mm thick central area of which contained expanded graphite.

The sandwich was easy to remove from the sheet former and press largely dry between felts.

It was then relatively flexible and held its shape well. The press-moist material was bent into a half-shell and so fully dried in a convection oven. This created one dimensionally stable half-shell, which may have multiple layers for covering of cables in cable bulkheads can be used.

A flat-dried sandwich of this type had a thickness of about 2.2 mm. It was placed in a preheated press, the plates of which were talcum-coated and hot at 600 ° C. The plates were set at a distance of 1 cm. In a few minutes the sandwich was expanded and filled the gap between the plates flush. It was then cooled and removed from the press. A dimensionally stable foam-like plate with smooth cover surfaces and a density of approx. 0.12 g / cm ^{3 had} formed.

Example 3

A mixture of the same was made on a Lödige mixer Parts of the expanded graphite and used in Example 1 Short glass fibers (type MF 7901, Bayer AG) manufactured.

Then the procedure was as in Example 1, except that now in addition to the wood pulp fibers (5 parts) 50 parts of the obi  mixture was used instead of expanded graphite. In turn, a dimensionally stable sheet was obtained which was used in the Flame showed vivid intumescence.

Example 4

Like example 3, but instead of short glass fibers same amount of so-called glass flakes used. It han This is a matter of very thin glass scales whose flanks sizing was similar to expandable graphite (flake glass, type C, from Owens Corning Fiberglas, USA).

It again became a dimensionally stable, mother-of-pearl-colored sheet get a lively intumescence on flame showed, and analogous to the materials from Example 1-3 showed no smoke formation.

Example 5

10 parts of unbleached softwood and 10 parts Glass fibers (see Example 3) were in 2500 parts of water with 10 parts of expanded graphite (see Example 3) and 5 parts Glass flakes (see Example 4) suspended. Then was on a continuously running laboratory paper machine made a sheet and pressed this wet. The press damp sheet had a thickness of about 2.9 mm and in tumescent lively when exposed to flame. It was flexible and dimensionally stable. The press-damp flexible sheet was between two toothed rollers pressed into a shaft and corrugated Condition dried. Here the waveform was fixed. Ribbons were cut from the corrugated material  the shaft had to lie across the axis and therefore very much good for wrapping pipes or cables in fire bulkheads are suitable. With such intumescent corrugated cardboard can also the interior of fire doors be dressed. In the event of a fire, the expansion of these works Lining against heat transfer through the door.

The sheet formed here or also according to Examples 1-4 can also be painted, laminated or coated the, e.g. B. with aluminum foil, and then forms, if necessary cut into a ribbon, a decorative one and against moisture as well as damage protected fire barrier in door joints, Wall joints or as a lining for switch boxes, Safes or cable bulkheads.

Example 6

5 parts of paper pulp, bleached, were mixed with 20 parts Expandable graphite suspended in about 1000 parts of water and on processed the sheet former into a sheet. That was pressed between felts and was then dimensionally stable. So then was from the flexible sheet in a press-moist condition a sleeve molded and dried. One received after Drying a dimensionally stable sleeve that lives when exposed to flame arrested intumescent.

Example 7

A filter paper was first placed in the sheet former then a fine-meshed iron wire net ("Flies wire mesh "). Then a suspension of 10 parts  Softwood ground paper and 100 parts expandable graphite (Example 1) abandoned, then again a layer of fine-mesh wire mesh. After suction was between pressed felts. One received a dimensionally stable Sandwich that folded into a small box and then was dried. When exposed to flame, the Wandma expanded material of the box, so that there is an insulating expan Formation layer on the flame side that formed the Effectively prevented access to heat inside the box.

Example 8

From a suspension of 2.5 parts of bleached paper fabric and 5 parts of micro glass fibers from Bayer AG (type: MGF-ATF 3101 [5005]) was on the sheet former (from approx. 1500 parts of water). This was before pressing with a sheet of 5 parts of paper material and 50 parts of expanded graphite (Example 1), and then both sheets were put together between felts pressed, with a firm connection between the two Scroll emerged. The resulting press moist and dimensionally stable laminate was cut into strips. An electrical cable was wrapped with these tapes in such a way that the graphite-free layer was on the outside. Besides, was the winding made so that several layers of Ban that came to lie on top of each other. When flame was applied due to the expansion of the wrapping, the cable is effective fully protected against the flame attack.  

Example 9

A fine-mesh wire network that spatially looks like a Egg boards or egg cartons was deformed, was under on the back reduced pressure on the front with a Sus pension made of 5 parts paper pulp and 40 parts expanded graphite (Example 1) applied, so that it with a sheet (layer) of solids which is broken up covering the entire surface of the suspension. After a layer thickness of about 3.5 mm on the net became sharp vacuumed and dried. You got one like one Egg boards spatially deformed cardboard plate from very good stability, lively intum with flame escaped. Such plates can be used as a filling for one steel fire door can be used. In the event of a fire the cavity in the door leaf fills up the expanded material of the honeycomb panel and hampered the heat transfer.

Example 10

The procedure was analogous to Example 9, but one was used Suspension of 5 parts paper pulp, 35 parts micro glass fiber (Example 8), 5 parts of reinforcing glass fiber cut (approx. 10 mm length), 25 parts of short glass fiber (case game 3) and 30 parts of expanded graphite (example 1) in 2500 Share water to make the egg-box-like plat te. The advantage of the high glass content is that with flames a good cohesion of the expansion body pers is achieved.  

Example 11

A sheet was made on a sheet former (Example 1) a suspension of 60 parts of micro glass fiber (example 8) and 20 parts of expanded graphite (Example 1) and 20 parts Expandable graphite (Example 2). That sheet was after pressing, dimensionally stable and intumescent at Be Flaming violent with extensive cohesion of the ex expansion body.

This sheet was dried out with a solution 5 parts sec. Ammonium phosphate and 45 parts of hexamethy lol-melamine impregnated and saturated in 50 parts of water dries. After drying, the sheet was placed on a Heat press condensed out at 130 ° C. This created a mechanically stable veneer board that is waterproof and was impermeable to water and lively intumescent when exposed to flame escaped while largely keeping the expansion together body.

Such panels can be used as fire-resistant veneers Laminate or chipboard in laboratory and plant construction Find use.

Example 12

The procedure was as in Example 1. Except the 5 Tei len paper stock has now become a mixture of 27 parts of glass fiber (Example 3) and 11.5 parts of swell graphite (Example 1) and 13.5 parts of neutral ethylenedi amine phosphate used as an aqueous suspension.  

After pressing, a dimensionally stable sheet was obtained, the wet wound into a sleeve and ge was dried. After drying, the sleeve shape was sta bil.

The sleeve intumesced violently when exposed to flame. she can for securing switching elements against the effects of flame be used. The phosphate does more than 3 hourly resistance of the intumescent body to oxi dative removal in air at 700 ° C.

Claims (9)

1. In the case of flaming, expandable or intumescent fabrics made by the process of producing paper and cardboard, characterized in that mixtures of fibers and expandable graphite are used in the process of papermaking. 2. Fabric according to claim 1, characterized net that mixtures of fibers and expanded graphites used in the aqueous process of papermaking. 3. Flat structure according to claims 1 and 2, characterized in that one uses as expanded graphite SO _x - and / or NO _x expandable graphite with scale-like particles with average surface diameters of 0.1 to 5 mm ver. 4. fabric according to claims 1 and 2, characterized ge indicates that cellulosic fibers or Fa serum mixtures containing cellulosic fibers, starts. 5. fabric according to claims 1 to 4, characterized ge indicates that such fiber mixtures are ver uses the glass fibers and / or mineral fibers ent hold.   6. fabric according to claims 1 to 5 thereby ge indicates that it contains 1 to 98% by weight of expanded graphite contain. 7. fabric according to claims 1 to 6, characterized ge indicates that it is in three-dimensional form mung available. 8. Intumescent construction elements for the front preventive fire protection, manufactured using of the fabrics according to claims 1 to 7. 9. Light molded body, produced by thermal Ex expansion of fabrics according to claims 1 to 7.