FR2581057A1 - Fluid composition for the production of protective layers which can be used as a coating or mulching and for the production of panels, and products produced - Google Patents

Abstract

This composition is noteworthy in that it comprises, as base constituent, slurries from the paper-making industry which are rich in cellulose fibres and in various inorganic fillers to which it is sufficient to add common adjuvants and, optionally, additional fillers to obtain an inexpensive composition which easily lends itself to the production of agricultural mulching, coatings and roughcast plasterings, or panels having various uses.

Description

 The subject of the invention is a particularly economical fluid composition which is easily adaptable to various uses where it serves as a protective layer either permanently or temporarily.

 Numerous compositions are already known which are intended for making coatings in the construction of buildings; the role of a plaster is to fill the surface of a rough wall to give it a smooth and geometrically perfect appearance or almost; it is also to protect this rough wall and, again, to correct some of its properties such as, for example, the insulating power from the thermal or sound point of view, the resistance to heat, etc.

 Owing to the various qualities which a composition of this kind must possess, sometimes to a high degree, it has always been accepted that it must contain a basic constituent of good quality, therefore of high price, to which certain additives are added. to promote certain properties or to facilitate application.

 For example, document FR-A-1 244 344 describes a composition essentially comprising plaster to which is added wood flour (up to 2.5%), vermiculite or perlite (up to 1, 5%).

 Document FR-A- 1 359 041 relates to a composition containing as a basic constituent a mixture of gypsum molding (40%), calibrated quartz sand (O to 0.7 mm) (44%), lime hydrated (10%), fiber in the form of asbestos fibers (2.5%) and wood pulp (1.5%).

 Document FR-A- 1 466 597 relates to a composition for producing plaster or plaster consisting essentially of a ground mineral material (30 kg), Meudon white (10 kg), perlite (25 l), and also, frequently, plaster (up to 20 kg).

 Document FR-A- 1 506 413 describes a composition intended for the manufacture of panels and loose-fill insulation, the basic component of which comprises up to 70 parts by weight of perlite, up to 35 parts of a cellulosic component. fibrous and up to 40 parts of a clay binder. This fibrous cellulosic component is obtained from newsprint, kraft paper, wood chips, shredded wood, rags, etc.

 In all of these known examples, the basic constituent is made up entirely or substantially of materials which are sometimes expensive, sometimes considered to be economical (such as recovered paper) but which require the initial manufacture of an expensive finished product. These examples also show that the use of fibers in these compositions was known, but that their percentage did not exceed 5% in plasters and plasters and 35% in compositions for insulating use; moreover, it is important to note that the fibers, when they are used, are in an apparently economical form but which requires the prior existence of an expensive finished product which must then be recovered and, in addition, treated for be suitable for its use, for example by shredding.

 The merit of the invention is to have understood that the same basic constituent, which is in the first place richer in cellulose fibers (up to 60%) is admissible for the production of panels and loose insulation and especially for the production of protective layers such as plasters or plasters and agricultural mulch, which is secondly richer also in fillers (up to 60%) of various natures (in particular but not exclusively of powdered mineral matter such as kaolin, chalk, talc, etc.) is also admissible in admixture with cellulose fibers for the production of protective and insulating layers; furthermore, such a basic constituent is capable, according to the invention, of being amended by appropriate additives according to its final destination.

 In accordance with a preferred aspect of the invention, a particularly advantageous basic constituent rich in cellulose fibers and in various mineral fillers is.

made up of stationery sludge, considered until now as waste which could not be disposed of except by rejecting it, after an expensive treatment, in order to avoid harming the environment.

It is known that, according to the paper mills, according to their supply of starting materials and of the final product produced, the sludges are different although still comparably rich in cellulose fibers and in various fillers. However, it has been found that these sludges are still usable as a basic constituent of a fluid composition capable of being adapted to a desired production in the field of coatings, plasters, mulching, panels, loose insulation; preferably a gorilla
tion of suitable adjuvants in moderate quantity not exceeding
not 20% by weight of the total weight of dry matter is practiced.

In this way, from this constituent of
base, an extremely economical composition is obtained since its main component is a product considered until now as a waste without useful use and requiring no special treatment prior to preparation for use.

 In the context of the invention, it is possible to use stationery sludges which are simply dehydrated, that is to say free of part of their water until they have a dry matter content of 30 to 50% by weight, but these sludges can be used without prior dewatering, with a dry matter content of 5 to 10% by weight.

It is possible to add additional charges
to the basic constituent in addition to those which the latter already contains, for example silica, calcium carbonate, but also, advantageously, other wastes
like sawdust, crushed chalk, black smoke, etc.

 A fluid composition in accordance with the invention composed almost exclusively of the basic constituent constituted by stationery sludge is well suited for agricultural mulching, with or without moderate dehydration; however, as this sludge does not spread easily in the natural state, it is preferable to add a little dispersant such as a surfactant known in the trade under the name dispersant GX in a proportion of less than 2 per thousand. by weight, and a little plasticizer known per se. This composition is a natural, biodegradable product which maintains humidity and which provides mineral sets to plants; naturally, insecticides or selective fertilizers or herbicides can also be added.

 This mulch composition is naturally absorbed into the soil over a period of several months. Its duration can be extended by adding a binder in proportion up to 5% by weight of the total weight; for example, from sludge which has been dewatered to have a dry matter content of approximately 50%, a binder can be added in a proportion reaching approximately 5% by weight. This composition can be molded and dried in rings or in flat rings which are perfectly suitable for the protection of trees and other plants; these washers are split and placed on the ground around the plants or trees to be protected; of course they are previously impregnated with products deemed desirable: bactericide, fungicide, insecticide, fertilizer, etc.

 Stationery sludge can also constitute an economic basic constituent for the production of plasters or plasters in buildings, mainly indoors, or in parts sheltered from the rain. It should be added, in moderate proportions, a binder and various auxiliary adjuvants such as fungicides, bactericides, dyes; preparation is easier if a dispersant is incorporated first. The binder may include glue, for example potato starch or carboxymethylcel lu lose.

 Contrary to what one might believe, stationery sludge is a basic constituent already so well suited to this use that the products to be added to it need not exceed a proportion of approximately 20% by weight of the total weight ; often a total proportion of additives of around 12% by weight is sufficient; the substance to be incorporated in the highest amount, from approximately 14% to approximately 7% by weight of the total weight, is the binder. The latter is, for example, a 50% aqueous dispersion of an acrylate copolymer which is commercially available under the acronal name 290 D from the German company BASF.

 One could, of course, increase the percentages indicated above, but without additional advantage and at the expense of the cost of the coating or plaster. The latter, having the general composition indicated above, can be applied against a surface by any known means, in particular by projection using a spraying machine, of a suitable known type. It suffices to adjust the consistency of the composition to the desired degree by adding water.

 It is also possible to add additional fillers, in particular lime, or finely ground calcium carbonate (hydrocarb) to the fluid composition containing the basic constituent. It has been found that the additional charge can reach approximately 30 to 40% by weight of the total weight of dry matter. However, insofar as this additional load is more costly than the basic constituent of the invention, it increases the cost of the plaster or plaster.

We will now give, by way of illustration of
the invention, an example of a fluid composition comprising as a basic constituent stationery sludge and usable as an interior coating giving complete satisfaction.
Example: The preparation of the composition is done as follows
In a stainless steel tank with a capacity of 100 liters, we introduced
Quantity a) of stationery sludge beforehand
dehydrated to a dryness of 50%
approximately (this sludge contained 50% of 27.5 kg
fibers and 50% of various loads); b) with stirring, the mixture was added
water 2 kg
dispersant GX (surfactant of
load dispersion) 0.2 kg
Urécoll S (urea-formaldehyde resin of 0.5 kg
German company BASF)
then we homogenized by stirring for
About 10 minutes; c) by continuing the agitation, the
fungicidal and bactericidal mixture
butylglycol 1.2 kg
dioctylphthalate 0.6 kg
water 0.6 kg
0.2 kg methylethanolamine d) still with stirring,
8% potato starch 4 kg
(alternatively you can replace the starch
by carboxymethylcellulose); e) was then added, several times, the
following mixture, maintaining agitation
water 27 kg
acronal 290 D at 50% 5 kg
stirring was continued for 10 minutes
to obtain good dispersion.

Quantity f) after addition of additional charges
following shouts
hydrocarbon CaC03 31.4 kg
lime 3 kg
kneaded for 15 to 20 minutes; g) we then proceeded to viscosity
suitable for addition projection
water in small quantities; possibly 20 to 30 kg
an anti-foam can be added.

It is better at this stage to shake again
for a period of 15 to 20 minutes.

h) if necessary, adjust the shade using
an aqueous paste of the desired color.

 There was thus obtained about 125 kg of plaster, having a dry extract of 40 to 42%.

 This composition is ready to use; it can be applied on all surfaces: plaster, iron, wood, paint, etc. It can be used at a temperature between 7 "and 40" C; the drying time is short, from 12 to 48 hours depending on the thickness of the layer and the humidity of the surrounding medium. The coating produced is economical and has good sound and thermal insulation properties; it has a pleasant appearance from an aesthetic point of view. Stationery sludge has more or less gray or white tints; you can choose sludges with a whiteness level greater than 70 if you want to obtain a plaster with a completely pleasant natural appearance.

From the example given above it appears that the preparation is generally carried out as follows: after homogeneous dispersion of the sludge in water, if necessary by adding a dispersant and a little water if the sludge has been previously dehydrated, at least one binder is added, possibly additional fillers (silica, C03Ca, ...) then additives: plasticizers, dispersants, bactericides, fungicides, defoamers, dyes
Stationery sludge has a density close to 1.2. It follows that the fluid composition obtained which contains this sludge as a basic constituent itself has a high density; the same applies to the final product obtained.

This situation is sometimes an advantage, for example for the mulch which remains better in place, of itself, on the fool.

When it comes to a plaster or plaster, a high density which corresponds to greater hardness and greater resistance is also an advantage.

 However, in other circumstances, it is desirable for the final product to have a lower density to which corresponds an alleviation making transport less expensive, or better resistance to the transmission of heat giving the product qualities of insulation.

 It has been found that the sludge serving as a basic constituent in accordance with the invention is perfectly compatible with a lightening and insulating product such as vermiculite or similar materials such as perlite.

 The vermiculite can be added to the fluid composition in an amount sufficient to lower the density of the final product obtained after drying to a value of about 0.3 to 0.5; however, the final product retains good cohesion and good mechanical strength.

Vermicutite is preferred because it is economical and because it is easy to dose and add to
The fluid composition. Preferably your preparation thereof is done as in the example given above but, after the last operation, slowly added and during continuous stirring, The charge intended to lower the density.

Vermiculite is preferred but can be replaced by analogous products such as grains or particles of expanded materials. At the same time as they lower the density, these materials increase the insolating power.

 This composition is then treated in a manner known per se to remove the water therefrom, to calibrate it in dimensions, with a view to obtaining panels or insulation in bulk. The washers mentioned above for the protection of trees can be shaped from this lightened composition to the degree deemed desirable; after drying they are then impregnated with suitable active products.

 The addition of vermiculite can reach up to 20% by weight of the total dry matter weight of the composition, the panels produced retaining sufficient rigidity. The effect of this addition lowers the density well below the average of the densities when the vermiculite is added by stirring and aerating the composition which then tends to form a foam.

 The panels obtained in the context of the invention also include what are commonly called false ceiling tiles or sound and thermal insulation tiles even when these tiles are not applied directly against a wall.

Claims (9)

 1. Fluid composition for the production of protective layers which can be used as a coating or mulch, containing cellulose fibers and fillers, with suitable adjuvants, characterized in that it contains a basic constituent comprising dry fibers of cellulose fibers in proportion of 40 to 60% by weight of this constituent and various fillers of finely divided mineral materials in proportion of 60 to 40% by weight of this constituent.  2. Fluid composition according to claim 1 characterized in that the basic constituent consists of stationery sludge composed in the dry state of at least 40% of cellulose fibers and various fillers comprising kaolin, chalk , talc.  3. Fluid composition according to any one of claims 1, 2 characterized in that it contains, in addition to the basic constituent, essentially dispersant and plasticizer as well as active products (insecticides,  fertilizers, selective herbicides) making it suitable for use as agricultural mulch.  4. Fluid composition according to any one of claims 1, 2 characterized in that it contains in addition to the basic constituent essentially dispersant, plasticizer and binder up to 5% by weight of the total weight of dry matter intended for the manufacture of plant and tree protection rings after impregnation with active products (bactericides, fungicides, insecticides, fertilizers, selective herbicides).  5. Composition for producing a plaster or plaster, characterized in that it comprises on the one hand a fluid composition according to any one of claims 1, 2 with suitable adjuvants comprising at least one dispersant, a binder, a plasticizer, on the other hand at least one additional charge of finely divided mineral matter, this additional charge representing approximately 30 to 40% of the total dry matter weight of the composition.  6. Composition according to claim 5 characterized in that the additional filler consists of lime and calcium carbonate  7. Composition for the production of panels, loose insulation and protection rings for plants and trees, characterized in that it comprises on the one hand a fluid composition according to any one of claims 1, 2, with suitable adjuvants comprising at least one dispersant, a binder, a plasticizer, on the other hand at least one additional charge of granular material with low density, preferably vermicutite.  8. Composition seton claim 7 characterized in that the additional filler is ta vermiculite in proportion up to 20% by weight of the total dry matter-of the composition.  9. Agricultural mulch, plant and tree protection rings, plasters, plasters, construction panels, characterized in that they consist of a composition comprising a basic constituent according to claims 1 or 2.