AU625898B2

AU625898B2 - Process for the manufacture of insulating panels

Info

Publication number: AU625898B2
Application number: AU33720/89A
Authority: AU
Inventors: Yves Bonnaud; Lucien Bourson; Jean-Paul Guillaume
Original assignee: Atochem SA
Current assignee: Arkema France SA
Priority date: 1988-04-27
Filing date: 1989-04-27
Publication date: 1992-07-16
Anticipated expiration: 2009-04-27
Also published as: NO891728L; FR2630765A1; EP0342071B1; AU3372089A; KR930002667B1; ZA893091B; ES2038832T3; PT90378A; PT90378B; EP0342071A1; FI891991A; FR2630765B1; GR3004226T3; DK201489A; DK201489D0; JPH0214861A; FI891991A0; CN1020294C; NO891728D0; CN1037373A

Abstract

The invention relates to a method of making insulating panels used in building. These panels are made by filtering a suspension comprising rock wool, clay, starch and wastepaper, and to which a basic aluminium polychlorosulphate has been added before filtration.

Description

glass wool, clay, waste paper and starch and can be used to PaThe present invention relates to a proc2,17,601 describess for the manufacture of insulating panels comprising glass fibre fabrics. Thes e panels consist of a mixture of rock wool ormaking ig lass wool, clay, wast be paper and when istarch and canis being moulded to insulate structurese n t invention relates more particularly canto Sbe painted or a decorative coating canformed by filtering adhesively drying a suspension.

thereto; they can be employed as false ceilings.

Patent Application DE OS 2,17,601 describes the manufacture of insulating panels comprising glass fibre 0 fabrcnsists in suThe disadvantage of thier glass woolthat o rock woolmaking ee or waste cardboard and starch. This suspension is then 5tnsfiltered through a cloth and a kind of moist plaque or board severalup the panel have to be handled when it is being moulded.

in a tunnel oven. Rigid plaques which can be used as a construction material are thus obtained. one of the -oe fthe u is tendow panel t cohesion and rigidity. The disadvantage of a process of this kind is 5 processes in which the panel is formed by filtering and then "."the remaining. drying a suspension.

o 15 A process for the manufacture of these panels consists in suspending in water glass wool or rock wool fibres, clay or another inorganic filler, ground waste paper 1o°° or waste cardboard and starch. This suspension is then filtered through a cloth and a kind of moist plaque or board 20 several centimetrs in thickness is obtained, which is dried in a tunnel oven. Rigid plaques which can be used as a construction material are thus obtained. One of the sIJ purposes of the starch is to endow the panel with cohesion and rigidity. The disadvantage of a process of this kind is that the starch is only partly retained in the moist plaque, the remaining part leaving in suspension with the t I :I l L nous: Ina(tul U tratoior". 92800 PUIAUX a e .M che RCS Nantre a 319 632 790 TUL 49 0 8 0 Tele ATO 611 i922 F 3 -3filtering water under the cloth. A new process has now been found which makes it possible to fix the starch better in the moist plaque during the filtration such that under the filter cloth, the water contains very little starch and generally very little suspended matter.

The process according to the invention comprises adding a metal polysalt before filtration to a suspension containing: at least one fibrous material, an inorganic filler, and starch.

A water suspension of the above products in a more or less divided state can be produced by any known means and a metal polysalt is then added to this suspension and this 15 suspension is filtered, for example on a continuous band filter, so that a moist plaque a few centimetres in thickness (the filter cake) is obtained which can then be dried.

Any fibrous material, for example vegetable fibres, 20 glass fibres or waste textile fibres may be employed.

However, rock wool or glass wool is preferred.

Clay in any of its forms, kaolin or calcium S carbonate may, for example, be chosen as an inorganic filler. A mixture of two or more of these inorganic fillers may, of course, be employed. Clay or a product consisting essentially of clay is preferably employed.

L_1 i'1 4 All kinds of starch may be employed, such as, for example, natural, so-called "unmodified" corn starch, or modified starch, such as anionic or cationic starch.

All these components of the suspension may be introduced in the dry state or in aqueous suspension, in one or more portions and in any order.

The metal polysalt 'is generally a product of the formula: [Mn (OH) Cl3n-m in which M is a trivalent metal, m and n are positive 0o.. integers, 3n-m is 0 and z is greater than or equal to 1t o. o Such products are known and are employed as flocculants in 00 water treatment.

oo0 The product in which M denotes aluminium is 0 0 15 preferred.

It is also possible to employ a product of formula: M (OH) X 3 n in which M is a metal which may be a tri- or polyvalent metal, X is an anion which may be Cl, NO, or CH 3 COO, 3n is S 20 greater than m with a basicity (m/3n x 100) of approximately from 30 to 83%, a polyvalent anion (called Y) having been S chemically introduced into the said basic salt, the quantity of anion Y being such that the ratio Y/M is 0.015 0.4.

This product is described in French Patent 2,036,685. The product in which M is aluminium, X is chlorine and Y is a sulphate is preferably employed. It is

I.

also possible to employ the product of the formula: Alm(OH)n

X

3 m-n- 2 k (SO4)k in which X denotes Cl or NO 3 k, m and n are positive numbers respectively, 3m n+2k, the basicity (n x 100)/3m is from 30 to 70% and k/m is from 0.01 to 0.3.

It can be manufactured by a process which consists in mixing a water-soluble sulphate or a solution containing

SO

4 ions, a solution containing Al and X and a solution of an alkali metal aluminate at a temperature below 40 0 C so as to produce a gel, and then maintaining the whole mixture at from 50 to 80 0 C so as to allow the gel to dissolve and thus :o o to obtain a solution of a basic aluminium salt.

oThis product is described in French patent 0"1 0 2,226,361.

15 The product of formula Al (CH) Cl in which x is o P2 Y from 1 to 3.5 and y from 5 to 2.5, may also be employed; S.:0o this product is described in US Patent 3,909,439.

It is also possible to employ basic aluminium 0:00 polychlorosulphates corresponding to the general formula: [Al (OH) (SO Cl n 3 n -m-2p 4 p E M in which: (3n-m-2p)/3n is from 0.4 to 0.7 nu_ be rp is from 0.04 n to 0.25 n m/p is from 8 to 35, and z is greater than or equal to 1.

This product may be prepared by the action of basic o i e o B 1 CT t banaslto o ai lmnu at 6 aluminium chloride on basic aluminium sulphate.

This process is described in French Patent 2,534,897.

It is also possible to employ the basic aluminium polychlorosulphates described in European Patent Application EP 218,487: Al OH (SO 4 )Cl 3 _m_ 2 k m 4 k 3-mn- -2k in which the basicity or the ratio (m x 100)/3n is from approximately 40% to approximately 65% and which has an Al equivalent/Cl equivalent ratio of from 2.8 to 5, an apparent o molecular mass AM, measured by conventional light scattering and apparent hydrodynamic diameters 0 Z and 0 W, measured by quasielastic light scattering, with the following values: AM 7,000 35,000 e o 15 *Z 350 2,500 *W 200 1,200 or such that: 00 0 MW 10,000 -300,000 z 90 450 *W 50 300 or else basic aluminium polychlorosulphate comprising the o• •product of general formula: Al OH (SO 4 )kC13n- 2 k which may, for example, be obtained by a process of the type comprising a step of preparation of a slurry of calcium chloride and of calcium carbonate (chlorocarbonate slurry), i 7 a step or bringing the chlorocarbonate slurry into contact with aluminium sulphate, then a step of separation of the reaction mixture thus obtained, enabling a calcium sulphate cake to be separated from a filtrate containing basic aluminium chlorosulphate, the quantities of chlorocarbonate slurry and of aluminium sulphate being such that in the case of the basic aluminium chlorosulphate obtained there is a ratio (m x 100)/3n of from approximately 40% to approximately 65% and an Al equivalent/Cl equivalent ratio of from 2.8 to It is also possible to employ basic aluminium o* polychlorosulphates comprising products having a certain degree of polymerization and of composition represented by the expression: 15 AlnCl (OH)3n+2km 2p (SO 4 )pXk o 0 in which: X denotes an alkaline-earth element, preferably 'tC calcium t C C n, m, p and k denote the molar concentrations (mol/1) of the components in solution 2fewer than 20% of the SO 2 ions can be C'C precipitated by the reaction with barium chloride at ambient s .1 temperature, whose basicity: (3n 2k m 2p) x 100/3n is from 45 to ;1 1- 8 These products may be manufactured according to a process which consists in preparing an aqueous solution containing the aluminium ion, the chloride ion and the sulphate ion, and in then bringing this solution into contact with an alkaline-earth metal compound and, lastly, in removing the alkaline-earth metal sulphate formed.

One or more of these metal salts may be employed.

It is preferable to add the metal polysalt to the suspension just before the filtration. It may also be added in several portions.

Although the suspension may contain the fibrous material, the inorganic filler and starch in any Qa o proportions, advantageously the fibrous material represents o 0808 from 50 to 80% by weight of the solids content of the 0 0o 8 15 suspension.

With regard to the inorganic filler, this is introduced in a proportion of 10 to 20% relative to the weight of the solids content of the suspension.

From 5 to 10% by weight of starch is usually Ore8 20 sufficient.

The quantity of metal polysalt is immaterial, but I it is usually sufficient to introduce a quantity of less I t than and preferably from 0.1 to 0.6% by weight of the solids content of the suspension, the sum of these proportions adding up to 100%.

f hmh Q I i IL l A cellulose-based material, such as waste timber, shavings, sawdust, waste paper or cardboard may also be added to this suspension.

It is preferred to add waste paper or waste cardboard to this suspension. Advantageously, this paper and cardboard is milled or shredded before being suspended, and it can also be put into the suspension partially milled and the suspension may be milled.

Advantageously, the quantity of paper or of cardboard or a mixture of paper and cardboard does not exceed 10% by weight of the solids content of the tt suspension, and is preferably from 2 to 7%.

It would not be a departure from the scope of the invention to add to the suspension expanded materials such 15 as vermiculite or perlite. It is also possible to add either hydrocarbon products such as bitumen or tars, which may be optionally dispersed in the suspension by means of surfactants. These expanded materials are used as a partial substitute for the fibrous material. Advantageously, up to 30% by weight of fibrous material may be replaced by perlite or vermiculite.

I

t would not be a departure from the scope of the invention to combine the metal polysalts with one or more synthetic flocculating agents.

These are, for example, poly(alkylene polyamines), poly(hydroxyalkylene polyamines) and polyacrylamides.

I-i 10 it would not be a departure from the scope of the invention to add to the suspension dyes, flame retardants and, in general, any products employed for making panels of this kind.

The following Examples further illustrate the invention.

0 0 o0 o SQ o 0 0 00 00 0 e o 00 6 t C L r:c i i ;ij

I

-'11 EXAMPLE 1 An aqueous suspension containing the following is prepared: rock wool 59% clay 13% starch :7% waste paper 4% scraps from previous panels (broken) 17% These percentages are by weight of the solids content of the suspension. This suspension is an aqueous solution containing between 25 and 30 g/l of solids content.

p on

I

'i'i Pooo o op o oa o p 6 O Pp 1 S0 0 «P ZI

I

Before filtration, a basic aluminium polychlorosulphate is added to the suspension, its formula 15 being such as described in FR 2,036,685, in which M is aluminium, X is chlorine, the basicity is 50% 5, and the anion Y is S04, such that Y/M 0.16 in a proportion of 0.5% relative to the fibrous composition, on a machine of the papermaking machine type. A moist panel 15 mm in thickness is obtained by filtration and is dried for 2 hours in a tunnel at 115 0

C.

The fire rating of the panels obtained according to French Standards CSTB 92501 and 92510 is MO.

The suspended matter (SM) content of the water collected under the filter cloth is 200 mg/l.

EXAMPLE 2 (Comparative) When operating as in Example 1, but employing a flocculant of an anionic polyacrylamide type without an aluminium salt instead of the above aluminium salt, the

L

K 12same panels are obtained; the SM content of the water under the clcth is 3,400 mg/i.

EXAMPLE 3 The operation is as in Example 1, but with of the rockwool replaced by perlite. The same results a~re obtained.

Claims

1. Process for the manufacture of a panel which comprises forming a moist plaque by filtering a suspension containing at least one fibrous material, an inorganic filler, starch, and a metal polysalt; and drying the moist plaque to form a panel.

2. Process according to claim 1 in which the Imetal polysalt is a metal polychloride.

3. Process according to claim 1 or 2 in which the fibrous material is glass wool or rock wool.

4. Process according to any one of claims 1 to 3, in which the inorganic filler consists essentially of clay.

5. Process according to any one of claims 1 to 4, in which the suspension also comprises a cellulose-based material.

6. Process according to any one of claims 2 to in which the metal polychloride is a basic aluminium p, lychlorosulphate.

7. Process according to claim 1 substantially as described in either of Examples 1 and 3.

8. A panel manufactured by a process as claimed Sin any one of claims 1 to 7. Dated this 29th day of April, 1992 ATOCHEM, By its Patent Attorneys DAVIES COLLISON CAVE :i l-o 3 t u