CA1113661A - Composite material - Google Patents

Abstract

COMPOSITE MATERIAL.

Abstract.

A composite material in semi-finished or finished form. Semi-finished material comprises cellulose fiber struc-ture, and evenly distributed throughout said structure, a polymer material being constituted by solid discrete part-icles or fibers having polymer at least at their surfaces, the polymer being a water-insoluble solid synthetic polymer which is film-forming at temperatures above 80°C, said particles or fibers of polymer material being bound in the composite mate-rial by means of a polyelectrolyte, and optionally inorganic particles or fibers of minerals or metals, including hydraulic binders. In finished form, film-forming properties of polymer have been elicited by application of energy. Finished products may be soft, elastic or hard materials or shaped articles.
Process for preparing the material comprises co-flocculating polymer material and optionally inorganic material with cellu-lose fiber pulp by means of polyelectrolyte, and de-watering resulting suspension on a paper making machine. Finished product is obtained from semi-finished product by application of heat and usually pressure.

Description

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This l.nvention concerns a composi.te material con--taining cellulose fibers, a process for preparing said material, certain materials for use in the composite material and processes for -their preparation.
The present invention is based upon -the concept of the uniform incorporation of a polymer material constituted by solid discrete particles or solid discrete ibers haviny polymer at least at their surfaces and optionally inorganic particles or fibers in a cellulose fiber structure through a wet process using polyelectroly-tes to obtain effec-tive flocculation of cellulose fibers, polymer particles or fibers and optionally inorganic particles or fibers to yield, after de-watering and drying, a product in which the said additives are uni-formly distributed in the cellulose fiber structure, and in which the cellulose fibers are substantially undenatured and are bonded together in the normal way like in paper or card-board. The polymer or polymers of the polymer material are such that the polymer material is non-sticky at room temperature and will substantially remain discrete part-icles or fibers upon incorporation in the cellulose fiber structure and drying. On the other hand, the polymers are such which are able to flow and bind or form film on ' '~' .~ ~

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application of enercJy in a suitable form, Eor example by heating.
The cellulose fiber struc-ture with the polymer material incorpora-ted therein as discrete elements and optionally with inorganic material incorporated therein constitutes a valuable semi-finished product which, depending upon its specific consti-tuents and their ratio, may be util-ized for a variety of importan-t purposes which make use of -the capability of the uniformly incorpora-ted polymer to flow and bind or form film on application of energy in a suitable form, for example by heating.
The form in which the polymer is incorporated is one in which it is chemically substantially inert to water and to cellulose fibers (in contrast to so-called "dispersions"
or "emulsions" often used as polymer forms for incorporation in cellulose pulp) whereby the inherent bondiny capabilities of the cellulose fibers are substantially undisturbed, and it is possible ~ to obtain coherent structures of the composite material with - even small contents of cellulose fibers. A wide variety of polymer forms already on the market for ot~er purposes, are available for very uniform incorporation into the cellulose fiber structure in accordance with the present inven-tion.
The polyelectrolytes contribute to the uniform distribution of polymer material and inorganic ' ' , ' . , ' , , ' , '' 3~

material in the cellulose fiber structure, and also contrlbute -to a high reten-tion when the process is per-formed on ~ paper making machine, thus contribu-ting -to maximum environmental accep-tability.
In the condition where the film-formation of the polymer has not been elici-ted, the composite materials of the invention may be in the form of paper- or cardboard--like sheet, web, plate, rod, profile, string or granulate materials,which through later applica-tion of heat or equi-valent forms of energy under sufficient conditions to elicit the bond- or film-forming properties of the polymer may be conver-ted in-to materials of many diEferent types, dependent upon the ratio be-tween cellulose fibers and polymer material, the kind and character of the polymer material, the content of optional additional materials (especially inorganic materials), and the performance and severity of the heat treatment and any pressure treatment, etc. The end products obtained by the final heat treatment may therefore vary Erom . .
` polymer-impregnated paper-, pasteboard- or cardboard-like materials -- to soft, elastic, or hard cellulose fiber-reinEorced polymer articles and even -to panels or shaped articles immediately appear-ing as having inorganic character, which to a large extent is de-termined by added inorganic materials such as minerals, including mineral or metal particles or Eibers. Common to all .. .~
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the end products in question, irrespective of the possible great difference in their charclcter, i5 that the~ contain cellulose fibers and a polymer as defined above, in which the : film-formation has been elici-ted, and tha-t, hence, they have been prepared from a semi-finished product or "plastic" which --contained cellulose fibers, the polymer material as defired above distributed evenly be-tween the cellulose fibers, and polyelectro-lyte, and which semi-finished product was, for most practical purposes, a continuous (that is bonded together -through the cellulose fibers) sheet-, web-, panel-, rod-, profile-or s-tring-shaped material. In some aspects of the present invention, -the cellulose fibers constitute a relatively large proportion of the end product and/or to a large extent contribute to the character of -the end product, where-as other end products prepared from the semi-product essentially show properties determined by the polymer material used and the additives used; in such cases, the cellulose fiber structure has primarily served as a carrier material in the semi-finished product and as an aid in obtaining an even distribution of polymer material and added inorganic material and to obtain further advantages which appear from the following.
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In one broad aspect, the inven-tion relates to a composite material comprising a cellulose fiber st:ructure in which the cellulose Eibers are bonded tc,ge-ther through bonds like in cardboard or paper, - ~

polymer material/ evenly distributed in the said struc-ture, the polymer material being constituted by solid discrete particles or fibers, said particles or fibers having polymer at least at their surfaces, the polymer or polymers of said polymer material being wa-ter-insoluble and water-non-swellable solid synthetic polymers which are non-sticky at room temperature and film-forming at tempera-o tures above 80 C, said particles or fibers of . polymer material being bound in the composite material by means of a polyelectrolyte, said polymers constituting at least 2% by weight of the composite material, ~'' and optionally inorganic material in the form of mineral or metal particles or fibers, said inorganic material being evenly distributed ` throughout the said cellulose fiber structure, and composite materials prepared from the above-defined compo-, ~ ~: S b . ~ ~

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;: site material through application of energy to elicit the .~ film-formation of the polymer.
,$ The process of -the :lnvention for preparing the above composite material comprises mixiny a polymer material constitutecl by solid, discrete particles or fibers, said particles-or fibers having polymer a-t least at -their surfaces, the polymer or polymers of said polymer material being synthetic water-insoluble and water-non-swellable solid synthetic polymers which are non-sticky at room temperature and film-forming at tempera-tures above 80C, wi-th a cellulose fiber pulp and optionally with inorganic material in the form of mineral or metal particles or fibers, co-flocculating the polymer material ~;~ with the cellulose fibers ancl with the inorganic material, if present, by means of a polyelectrolyte, and i~. thereafter de-watering the resulting suspension to form a coherent sheet, web, or extrudate material, drying the cohe-: `
rent material under conditions which do not elicit the film-i::
~:. -formation of the polymer, the polymer of the polymer material being such that the polymer material remains :f : .
substantially discrete particles or fibers upon said drying, and optionally subjecting the dry material to a treatment which will elicit the film-forming properties of the polymer, for example by application of heat and optionally pressure.
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The above-mentioned semi-flnished produc-t ob-tained upon drying under conditions which do not elicit the film--formin~ properties of the polymer may, if desired, be sub-jected to the treatment elicitlng the Eilm-formation of the polymer immediately subsequent to the drying, optionally in the same production line, for example through heat and optionally pressure trea-tment, or alternatively, it may be shipped as it is or af-ter gxanulation, in other - word~ as a "plastic" or semi-finished product for later preparation of end products from this semi-finished product through desired shaping or moulding and eliciting of the film-forming properties of the polymer.
In the present context, the term "film-forming at temperatures above 80C" is intended ~o characterize a polymer which, when applied, in the form of a dry powder, on a surface and heated to above 80C is capable of flowing to form a film wi-thin at the most 60 minutes. Preferably, the film--formation under the conditions mentioned will take place in the course of about 10 seconds or less to abou-t 15 minutes, and it is often preferred to use polymers, the film-formation of which within such shorter periods is only elicited at tempe-ratures above 120C. Because of the water-insoluble and water--non-swellable character of the polymers used according to this invention, they are able to form a film which is sub-stantially water-tight and water-resistant.
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Polymers comply1n~J with the above r~quire-ments are various thermoplastic polymers, which during the heat treatment may further polymerize, but will not neces-sarily further polymerize, and various thermoset-ting poly-mers, includlng such -thermoset-ting polymers which polymerize by a built-in curing or cross linking agent, the effect of which is released at a certain heat treatment, and the effect of which may have a more or less ~uick on-set.
Polymers which are in the form of "dispersions", "emulsions" or "sols" in which the particles coalesce wi-th each other to Eorm film upon evaporation of water are not contem-plated as polymer materials for the purpose og this invention. As indicated above, such "dispersions", "sols" or "emulsions" of more ., .
or less sticky resin ma-terials are widely used as additives to cellulose pulps prior to sheet formation, for example to impart a better wet strength to the paper ma-terial. Common to these resin materials is that they have at least a certain affinity to water and the wet cellulose fibers, but they also show a tendency to migrate with the water. Furthermore, tha processes , additives and modifications used to emulsify or disperse such polymer forms in water and/or to impart to them their emulsifiable or dispersible properties, at the same time tend to reduce their final strength properties, and they will generally not be capable of yielding as strong films or : .
bonds as the water-insoluble and water-non-swellable solid , .
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polymers used accordi.ng to the invention which will no-t coalesce under the incorpora-tion ancl drying conditions and : which can be characterized as chemically subs-tantially inert to water ancl cellulose fibers and, hence, will not disturb the pH conditions of the cellulose pulp or the hydrogen bonds between -the cellulose fibers.
Thus, the polymer forms used according to the present invention are mostly forms which have not been designed or adapted for incorporation in cellulose pulps, and yet, it has been found that by means of the polyelectrolytes, they may . be effectively distributed evenly and retained in the cellulose structure without mi~ration during the web formation. Only when the film-forming properties of the polymer is elicited, the polymer of these substantially inert elements will flow and form bonds or even a coherent film in the material.

As examples of polymers suitable for the purpose ~ of the present invention may be mentioned polyolefins such `~. as polyethylene and polypropylene, vinyl polymers such as .~ polyvinyl chloride, polyvinyl acetate and polystyrene, poly-imides, polyamides, polyacrylates, ABS, epoxy resins, epoxy/
phenol resins, phenol resins, urea resins, melamine, poly-ester resins, melamine polyester, cross-linked acrylic resins, silicone resins, polyurethane resins, and copolymerisates :
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thereof such as copolyamicles. Such polymers are available ln 501icl forms in which they may be converted in-to a coherent film -at temperatures above ~0C for periods from abou-t 10 seconds to abou-t 15 minutes. The heating -treatment may he performed by high frequency treatment, ultrasound -treatment, i.nfrared radiation, microwaves and/or conventional application of i heat.

One interestiny polymer material for the purpose of the present inven-tion is finely divided polymer material prepared from waste, for example suitable thermoplastics - such as polyethylene ground at low temperature.
Also synthetic vulcanisable elastomers such as SBR in suitable forms are useful as the polymer for the purpose of the present invention.

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:; ` `' ' - ~or the preparation oL composi~ materials which, : in the:ir forrn as Ein:islled products or shaped articles are to be used for outdoor purposes, it is advantac3eous -to use inl^leren-tly weather-resisterlt polymers, for examp.Le single .
component addi-tion pol~mers such as cross-linked acrylic resins, polyesters, epoxy polyes-ters and polyurethanes, but also for example polyvinyl chloride, polypropylene and polyethylene are suitable polymers for preparing producs for outdoor application. For other purposes, for example containers for liqu.id products, including beverages such as milk or juice, polyethylene, polypropylene and copolymerized or otherwise hydrofobized melamine, for example melamine polyester, are preferred polymers.
It is within -the scope of the present invention ' ' ~ to use more than one polymer material. Thus, for example, j, a cross-linked synthetic polymer such as a polyester can be combined with a thermoplas-tic polymer such as polyethylene polyvinyl chloride, or polypropylene. It is also possible to ~ use the cross-linked polymer together with for example ?:: powder bitumen or bitumen emulsion which act as a cheap ~, ~
structure-filling, water--tightening component, preferably together with incorporation of a water film-~isrupting surface-active material such as a -tenside.
Another example of -the combination of two polymer materials is a combination of non-plasticized polyvinyl chloride and plasticized polyvinyl chloride. According to the invention, it has been found that the combination of an essentially non-plasticized polymer and a relatively highly plasticized polymer is often to be preferred over the use of one polymer plas-ticized to a lesser degree.

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When the polymer materia:l us~d accordiny to the invelltion is p~rticles cons.isting of polymer throucJhou-t, such powdery polymer mclterial has a particle ~.
size of the order of 1 - 500/u, preferably 1 - 200/u and especially 10 - 80/u. Al-ternatively, the polymer material may consist of polymer applied on an inorganic carrier, for example me-tal particles such as particles of brass,~
iron, zinc, aluminum, copper or bronze, or mineral or other inorganic particles such as TiO2, iron oxide, wollastonite, kaolin, de-glassed glass, calcium carbonate, quartz, including sand, silica, stea-ti-te, talk, aluminum silicate, Synopal, barytes, dia-tomaceous earth, or amorphous SiO2.
Such particles of polymer applied on an inorganic carrier -ty-pically have a particle size of 1 - 500 /u, preferably 1 -200 /u. Another polymer material is polymer applied on mine-ral fibers such as glass wool, rovings, s-tone wool, slag wool, kaolin wool, or metal fibers such as fibers of brass, copper, aluminum, bronze or iron. The length of such inorga-nic fibers with polymer applied thereon is ~typically from about 100 /u to about 3 mm, and -the -thickness is typically from about 5 to about 30 /u. Certain minerals are avail-able in par-ticles which are rather elonga~ted, for example wollastonite, but in the present context are considered particles and not ~ibers.
Some polymer materials with polymer applied on an inorganic carrier are commercial products manufactured, for example, for use in powder coating processes. The fraction of such products in the range below 30/u and above 30/u are usually considered as waste, but for the ,.

purpose of the present- inventloll, sllch fractlons, like the fractlon in the rancJe of 30 - ~0/u, are well suited~
Exam~les o~ such commercial powder coating materials are polyolefins or epoxy, polyes-ter, acrylic or polyamide resins applied on TiO2 particles, the amount of -the poly-mer belng 40 - 90~ by weight, calculated on -the total material, the hiyher weight amounts usually applying when the polymer is a polyolefin, a weight amoun-t of 40 - 60 by weight being the normal range when the polymer is an epoxy, polyester, acrylic or polyamide resin.
For the purpose of the present invention, a considerably smaller amount of polymer applied on the inorganic carrier will be sufficien-t for most purposes, for example 2 - 40% by weight, 2 - 20% by weight being typical values for fibrous carrier materials and 5 - 40%
by weight being typical values for particulate materials.
Particulate or fibrous polymer materials in which the polymer is applied on an inorganic carrier may be prepared in various ways. One way for preparing particulate polymer materials on an inorganic carrier is to extrude a mixture of carrier and the polymer and thereafter grind the mixture. When a thermosetting polymer is used in this operation, the extrusion should ta]ce place at a temperature at which the curing of the polymer is not elicited. The best compatibility between the polymer and the inorganic carrier material is obtained when one of these materials has a positive electrical surface potential and the other one has a negative elec-trical surface potential. Most polymers useful for the purpose of the present invention have inherently a negative surface potential, and most , - - , ~ -,:
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;' ~ ' ' carrier mat~r.Lals a].so have negat:ive surface potential, and when combin:iny such materials wh.ich both i.nherently have a negative surface potential, i-t may be suitable -to treat the carrier ma-terial with an ayen-t changing -the surface potential o:E the inorganic material from nega-tive to positive. Various so-called coupling agen-ts, i.e. com-pounds which are able -to combine with both polymer and inorganic materials and thereby increase -the compa-tibility between the polymer and the inorgani.c carrier or additive material have been found to have this property.
Such coupling agents are for example si.lanes (for example Silan A 1100, which is y-amino~ropyltri-e-thoxysilan from Union Carbide Corporation, New York, N.Y., U.S.A., and Dynasylan ~ MEMO (y-methacryloxypropyl trime-thoxysilan) or Dynasylan ~ GLYMO (y-glycidyloxy-propyltrimethoxysilan) from Dynamit Nobel, Germany, and chromium complexes (for example Volan ~ (a me-thacrylic chromium complex of Werner-type from Seppic, Paris, France)).

To ensure a particularly effective distribu-tion of the poly-mer on the carrier particles or fibres and to obtain a coherent polymer coating o~ maximum uniformity on the particles or fibres, a special process of the present invention for preparing polymer-coated particles or fibers comprises maintaining particles or fibers of carrier mate-rial under vigorous agitation while in dried and optionally heated condition, for example with stirring or in an air flow while t~e polymer is sprayed or added little by little in liquid or semi-liquid condition. (The polymer may also be added i:n solid state when the carrier material has a sufficiently high temperature during the application ' ' ' ~',' ' ' ' ' ' ~3~6~
process, us -the po]ymer, for example in -the form of solid par-ticles, wi:Ll then be converted by -the hea-t into the liquid or semi~liquid s-tElte necessary for the coa-ting.) For example, a powder of wollastoni-te par-ticles is hea-ted to about 350C for removal of wa-ter film on the surface, wherea~ter a-t a -tempera-ture of above lOO~C (-to ensure that no water film is re~established on -the particles~
during the process) a polymer in solid, liquid or semi-liquid sta-te may be added to the agita-ted powder, for example a polyester or a pas-te-~ormed solvent free single-componen-t epoxy resin such as "~raldit AV8"
(from Ciba-Geigy, Switzerland) which is a thermosetting epoxy resin pas-te, or polyethylene.

The agitation of the inorganic carrier par-ticles or fibers may be obtained in various ways, and i-t is wi~thin the scope of this invention to coa-t ~ibers in fluid bed with polymer, optionally with utilization of opposite electrostatic charge on fibers and polymer, and to apply the polymer (and optional processing aids, including tensides) immediately subsequent to the formation of glass wool fib-rs or stone wool fibers, and while these are being transported, by means of vacuum or an air flow, respectively, from the spinning elements where they were formed.
Mineral fib-rs with a coating of polymer which is film-forming at temperatures above 80C, especially a coating constituting 2 - 40% by weight of the combined materi-al, constitute an especially interesting polymer material which may be prepared as described above, and which, in addition . ~ j .
to the process of the invention and incorporation in the ;'` ' - ' .

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~3~ a products accorcling to the invent:i.on, may be use~ for many other purposes where a film-forminc3 polymer is to be used.
As such materials show a large exposed surface of film-forming polymer in comparison with -the amount of polymer, -they may be used as a very economical substitutes for polymer materials consisting solely of the polymer in question, for example in the preparation of various composite materials of otherwise known type. Apart from this, they may be used for the preparation of various novel products, the special properties of which depend upo~ the bonding between such mineral fibers with a coating of film-forming polymer.
Also fibers consisting solely of the film-forming polymer or a combination of film forming polymer may be used.
However, an advantage of polymer ma-terials comprising polymer applied upon particles or fibers, in addition to the factthat these may inherently, by their incorporation, incorporate a desired inorganic component of the composite material, is that polymer having an inherent density below 1 will result in polymer materials with a density above 1 when combined with the inorganic carrier in sufficient amount. Particles or fibers having a densi-ty above 1 are more efficiently co-flocculated with cellulose fibers.
In one special aspect of the invention, the polymer of the polymer material may contain a blowing agent which, under the temperature conditions at which the film-forming properties of the polymer are elicited, simul-taneously foams up the polymer to yield a cell structure, for example by vigorous evaporation or chemical reaction with evolution of a gas. Hereby, cellulose fiber-reinforced S17 ~ 7 ., ~., ` , : :
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composi-te ~laterials can be obtained. Polymers 7 ~or e~ample polystyrene, con-taining blowing agen-ts are cornmercially available. The blowing sys-tem of -the polymer selec-ted should be one which is only elicited a-t a sui-table high temperature so -tha-t there will not be any undesired foaming during the drying of the composite material.

When an inorganic material in -the ~orm of mineral or metal par-ticles or fibers is -to be incorporated in -the composite ma-terial, such particles or fibers are prefe rably -the same particles or fibers as are men-tioned above as possible carriers in polymer materials, tha-t is, me-tal particles such as par-ticles of brass, iron, zinc, aluminum, copper, or bronze, or mineral or other inor-ganic particles such as TiO2, iron oxide, wollas-tonite, kaolin, de-glassed glass, calcium carbonate, quartz, including sand, silica, steatite, talc, aluminum silicate, Synopal, barytes, diatomaceous earth, or amorphous SiO2, the particle size of such inorganic particles typically being 1 - 500 /u, or mineral fibers such as glass wool, ~-rovings, stone wool, slag wool, kaolin wool, or metal fibers such as ~ibers o~ brass, copper, aluminum, bronze, or iron. A special type of inorganic material which may be incorporated is a hydraulic binder such as cement or kaolin cement. To improve the compatibili-ty between polymer and added inorganic material when the film-forming properties o~ the polymer are later on elicited, a "coupling agent" of the type mentioned above, for example a silan, may be used. The inorganic material may pre-viously be treated with the coupling agent, or the coupling ,~
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agen-t may be a~decl to -the cellulose pulp, for example simuL-taneously with the inorganic ma-terial.
In -the process of the inven-tion, -the polymer ma--terial is incorpora-ted in an a~ueous suspension of cel-lulose ~ibers, also called a cellulose fiber pulp, opti-onally -toge-ther wi-th inorganic ma-terial as discussed above. The cellulose fiber pulp may be prepared in the~
usual manner from for example sulphate or long-fibered sulphite cellulose, waste paper and waste cardboard, straw cellulose, -thermomechanic cellulose fibers and op-tionally synthe-tic cellulose fibers such as rayon fibers. Waste cardboard is an especially suitable s-tarting material.
Cardboard may be converted in-to a cellulose fiber pulp by treatment in a pulper, optionally at an elevated tem-perature of up to 60C. The cellulose fiber concen-tration in the resulting cellulose pulp may, for example, be 1/2 - 4% by weight, usually at the most about 2~o by weight . .
and in ordinary paper making machines often 1/2 - 1,~ by weight. The cellulose fiber pulp may be treated according to conventional paper technology methods, for example by ;
treatment in a hydrocyclone and in deflakers.
At a suitable point during or after pulping and prior to web formation, tensides, for example non-ionic -tensides, antifoaming agents, aluminum hydroxide, ammonium phospha-te, -diphosphate or -polyphospha-te may be added. The non-ionic tensides reduce the interface activity, break molecular water film on particles and fibers and contribute :~:
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to removal. oE mlnor alr bubbles fxom polymer ma-terial and the optional inorcJanic material and may also contribute to the obtainment of a more compact final product. ~luminum hydroxide imparts greater fire resistance to the resulting material, and the ammonium phospha-te materials ~nentioned are known defibrating agents used in paper industry and contribute to make the material more fire resistant. Also other fire inhibitiny age:nts for example antimony trioxide or halogen-containing compounds, may be added at -this stage.
The suspension to be floccula-ted should conform with such conditions with respect to pH value and zeta potential which are known within paper technology to yield a good retention. The pH is usually in the range of 5 - 8 but may also be higher, for example up to 9. ~he zeta poten-tial is preferably kept at a low numerical value which is between +20 and -20 millivolts, preerably in the range of about +10 to -10 millivolts and especially in the range between +5 and -5 millivolts. It is well known that changes of the pH and/or ionic strength of the suspension will -change the zeta potential. Also, for example addition of strongly cationic or strongly anionic tensides will sub-stantially change the zeta potential and may in certain cases even convert the zeta potential from positive-to negative or vice versa. Silanes and polyelectrolytes have also been found to have a considerable influence upon ~he zeta potential of suspensions of the present kind.
In order to further improve the flocculation, opposite electric surface potential of cellulose fibers 20:

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a~d polyrner material m~y ~e utili~ed. Cellulose fibers inherently h~ve a relatively hi~h nec3a-tive sur~ace potential, and -the same applies to certain polymer ma-terials such as polyesters an~ epoxy resin. I-t may be suitable in such cases -to "convert" the surface potential of the polymer-material, Eor example using a cationic tenside o~ a type which, when it has been applied on -the polymer with sub-sequent dryin~, canno-t be re-dissolved in water, ~or example Fintex 577 which is dealt with in greater de-tail in the examples. Also treatment with silanes and subsequent drying to build up a monomolecular layer may convert an inherently negative surface potential on polymers into positive. The treatment of polymer materials with cationic tensides can be performed for example by adding the cationic tenside to an aqueous suspension of the polymer material and thereafter drying the polymer material. Another possibility is to treat dried, heated polymer particles with cationic tenside A third possibility is -to incorporate cationic tenside in the polymer proper.
The Schopper Riegler degree of the cellulose fibers in the cellulose pulp may ~ary within wide limits, for example from about 15 to about 80. Often, the Schopper Riegler degree will be in the range of 3Q - 60, for exam-ple 30 - 40 or especially 40 - 60. When the cellulose fi-bers are thermomechanic fibers, the Schopper Riegler de-gree is preferably lower, for example about 15.

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Accordirlg -to the inventlon, the polymer material is incorporate~ by co-flocculation by means of a poly-electroly-te. Polye]ectroly-tes are macromolecules with "buil~t-in" ionic groups, vide for example, Rompps Chemie-Lexikon, 7th Edi-tion 3 Stuttgart, 1975, page 2755 - 2756.
The polyelectrolytes preferred for -the purpose of this invention are syn-thetic wa-ter soluble polyelec-trolytes adapted for flocculation purposes, but are no-t necessari ly polyelectrolytes which have previously been suggested for use in cellulose pulps. The bes-t resul-ts are often ob-tained with cationic polyelectrolytes, but also anionic .
polyelectrolytes may be used, and in certain cases, both an anionic and a ca-tionic polyelectrolyte may be useful to ensure co-floccula-tion of all components. Examples of suitable polyelectrolytes are Prodefloc ~ AC (a water soluble anionic flocculan-t, polyelec-trolyte, aluminum chlorohydrate, from Prodeco, San Donato Milanese, Italy, and Prodefloc N/2M (a high molecular, water soluble an-ionic polymer flocculant). Examples of cationic polyelec-trolytes are Prodefloc CL2, Prodefloc Cl, Prodefloc C4, Prodefloc C6 and Prodefloc C8, all of which are water soluble cationic polyelectrolyte flocculants. Prodefloc Cl has been found to be a very suitable polyelectrolyte for the purpose of this invention. Other ca-tionic polyelec-trolytes are Hercufloc 829.~ (strongly cationic) and Hercufloc 859, both polyacryl amides, from Hercules Pow-der Company.
The polyelectrolyte is usually added in a concen-tration of 0.005 - 2% by weight, e.g. O.Ol - 2% by weigh-t, calculated on dry weight of the constituents of the sus-S22 ~ ~2 : .

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pension -to be floccula-ted. Often, very satisfac-tory re-sul-ts are obtainecl with abou-t O.l - 0.25% o~ a ca-tionic polyelec-troly~te such as Prodefloc Cl.
The polyelec-trolyte or polyele~-troly-tes are prefe-rably added to the mixed suspension immediately prior to subjec-ting -the suspension to the de-watering, and it is preferred to avoid vigourous agi-tation a~ter addition ~f -the polyelectroly-te.
In some cases, the retention is impro~ed when a conventional cellulose fiber floccula-ting agent such as alum and1or a silan is added -to the cellulose fiber pulp prior to addi-tion of -the polyelectroly-te. ~f a silan is added, the concentration thereof is usually O.l 2% by weight, preferably O. 2 - 1% by weight, calculated on the dry weigh-t of -the components of the suspension. In addi--tion -to assis-ting in improved floccula-tion in systems where an inorganic material is added, the silan will al-so later on~ upon elici-ting of the film-forming proper-ties of the polymer, be advantageous in that it functions as a coupling agent.
When silan and conven-tional cellulose fiber floccu-lating agents such as alum are added, these are usually added before or during -the mixing of the components of the suspension.
The optimum flocculation in a particular system may be assessed by the skilled art worker by means of easily performed introductory model experimen-ts.
The polymer ma-terial may be combined with the cellulose pulp in the machine chest where effective mix-ing of these components and the op-tional inorganic mate-S23 ~ 3 . ~ ` ; , .... ..

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rial may be per~`ormecl with suitable mixing means such asa stirrer, the polye~ec-trolyte being -therea~ter added immeclia-tely prior -to passing -the suspension -to the dehy-drating s-tage.
I-t is of-ten preferred -to add the polymer material to cellulose pulp as an aqueous suspension ra-ther -than as a dry ma-terial. Such suspension may suitably be pre-pared in a high concentration, for example a solid content, of 30 - 90%, by vigorous agi-tation, using, for example, surface active agents such as Berol 373, -the data o~
which are stated in connec-tion with the examples. Also, thixotropy agen-ts may be added to -the suspension to avoid sedimentation. The suspension of the polymer material is suitably main-tained at room temperature. l~hen an inorga-nic material is -to be added, this may be either added separately, in dry form or in aqueous suspension, or'it may be included in the suspension containing the polymer material.
When the polymer material and/or the inorganic material comprises fibers, it is desired -that they are in defibrilated form before they are combined with -the cel-lulose pulp. Effective defibrilation may be obtained by beating the fibers in the presence of a suitable tenside, and it has also been found according to the invention that agitation, for short periods of at the most 1 minu-te, of the fibers with a polyelectrolyte results in an effi-cient defibrilation of fibers. Fiber materials are prefe-rably defibrilated in aqueous suspension of a concentra-tion of less than 1%, for example, an effective method of defibrilating glass wool is to beat glass wool in a con-S24 , 2 ~
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cerl-tration oE 0.5(~o in wa-ter, for a period of a-t the most 1 minute in the presence of a cationic pol~elec--trolyte such as Prodefloc Cl in a concentra-tion of for example 0.01%
When the composite material is to be used for articles which, ln their end use, are to be stable for long periods under conditions involving exposure to mois-ture, the cellulose fibers may be protected against de-terioration by addi-tion of an antimicrobial agen-t, for example a fungicide. The antimicrobial agen-t may be applied on the surface of -the finished articles subsequent -to -~heir final heat treatment, for example in the form of antimicrobial sprays or as cons-tituen-ts of a paint coating or other coating.

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:[n the prepara-tion of composite materials for ar--ticles which are -to be exposed -to moisture, f'or example, roofing panels or bui:Lding panels, it may also be suitable to add an an-ti-mois-ture impregna-ting agen-t, for example one of ~the known "wood protecting oils" such as Pinotex ~, Goriol ~, or Bondex ~ , preferably in colourless forrn.
These wood protecting oils may easily be emulsified and co floccula-ted wi-th the cellulose pulp. Bi-tumen emulsion and parafin emulsion are o-ther sui-table impregnating agents which may be added -to the cellulose pulp prior to -the flocculation. ~n in-teresting impregnating agent is an oil emulsion with an added ca-tionic tenside which is decomposed at temperatures of abou-t 100C. By addition of such emulsion, the following function can be obtained:
Firs-t, the emulsion is co-flocculated with the cellulose ' pulp, and in the web formation, the cellulose fibers are bonded through hydrogen bonds. In the drying opera-tion, the tenside from the oil emulsion is decomposed due to the drying heat, and through -this, the cellulose fibers are effectively impregnated with the oil which has a ten-dency to penetrate into the ends of the cellulose fibers.
On the subsequent eliciting of the film-forming proper-ties of the polymer, a strong, water-resistent material is obtained.
'With respect to -the wa-ter resistence of the ar-ticles prepared from the composite material, it may be suitable to use tensides and polyelectrolytes which are decomposed during the heat -trea-tment~ as tensides and polyelectrolytes ~' tend to be hygroscopic.

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In connectiorl with the ~preparatiorl of cornposite materials comprising cement;, it has been found -tha-t the op-timum floccu:La-tion and reten-tion is obtained by first adding a ca-tionic polyelectroly-te and subsequen-tly adding a po-lyelectro~Lyte, vide Examples 50 - 54.
In the following descrip-tion of the process, the paper making machine is clescribed as a machine of -the endless wire type, but -the process may also be performed --on any o-ther type of paper making machine, or other ma-chine adapted for de-watering a floccula-ted suspension -to form a web or sheet, for example -the hydroformer or roto-former type ("non-woven"-type).

~ successful co-flocculation manifests itself in ~at the added par-ticles or fibers of polymer ma-terial and op-tionally other additions, especially inorganic material, are re-tained practically completely in the flocks on the wire and are not entrained with the wa-ter passing the wire, not even when ver~ small particles of for example 5 /u or less are concerned. The de-watering treatment is performed in a manner known per se and with a wire velocity adapted to the character of the cellulose pulp, the content of added materials, the efficiency of suction, the de-sired web -thickness, etc. In some embodiments of the present invention, it is desired to prepare relatively thick sheets or webs with sheet weigh-ts up to for example 2 - 3 kg/m2 (dry weight), and in these cases it may be suitable to keep the wire velocity small at certain types of paper making machines. Normally, the wire velocities ~7 . . ~

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ln ordinar~J paper ma~ing machines are between 10 an~ 500 meters per minute, ~ut when i-t is desired to prepare webs with high sheet weights up to for e~ample 2 - ~ kg, wire veloci-ties as low as 2 - 10 me-ters per minute may be used.
Therea~ter, -the web forme~ by the bonding between cellulose fibers (hydrogen bonds) ma~ be passe~ from the wire to drying and rolling up stages in a ~lanner known per se, for example through passage between the conve~ti-onal wet press rollers and over he~-ted drums, optionally with a cooling drum immediately prior to -the winding up.
It is important -tha-t -the drying is performed under time temperature conditlons which will not elici-t the film~
forming proper-ties of the polymer material. Suitable drying temperatures are in the range up to abou-t 110C, for example in the range of 80 - 100C. To obtain good re-sults in the later eliciting of -the ~onding or film-forming properties of -the polymer, it is necessary that the web has previously been effectively dried, preferably to a water content of at the rnost 5% by weight or most preferably to constant weight. It mi~ht in principle be possible to ship the semi-finished product with a higher water content, for example up to 50% by weight, and the further drying could then be performed in connection with any shaping treatment prior to the final heat treat~
ment. However, the most suitable "dry" semi-finished product will be one having a water content of at the most 25, especially at the most 15, ~ by weight and preferably at the most 5~ by weight.
The composite material of the invention in the form of the semi-finished product may be shipped in the form of rolls, sheets or stripes, or,if the de-watering ` .

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has been per~ormed in an extruder, in the form of an extrudate, but it may also, in the man~facturing station, be punched or cut to desired shapes and sizes corresponding to the produc-ts or articles to which it i5 to be converted in the final heat treatment. The was-te material resulti~g from the cutting or punching operation may be recycled; it may si~ply be beaten in t;he pulper and can constitute part of the startiny material i~or a later production.
~ ~hen it is desired to subject the semi-finished product to the final heat treatment in the factory where the semi-finished product is produced, the dried web can suitably proceed directly to the further treatment where the temperature is elevated from drying temperature to film-forming temperature. Prior to or simultaneously with the elevation of the temperature to the film-forming temperature, the web or sheet may be subjected to a forming or shaping operation, usually under pressure. This shaping operation may also be performed at a stage where the web has not been totally dried, the further drying being then performed in a later stage.
As mentioned above, the composite material in the form of the semi-finished product may also be prepared in the form of an extrudate in that the wet material is subjected to extruding in a manner known per se, the drying being performed simultaneously with or subsequent to extruding. The extruding techni~ue may be used for pre-paring even very thick materials in large plate or tube dimensions.

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3~1 Wherl the semi-Elnished product of the invention is -to be in lamina~ted, possibly cross-larnina-ted form, -this may either be prepared by ]amina-ting mois-t webs on or after the wire of the paper malcin~ machine, or dry sheets or webs may be moistened a little, for example with steam, and thereby brough-t to adhere through the hydroyen bonds of the cellulose fibers.
The composite material oE the inven-tion can easi-ly be adhered to limitin~ surfaces, for example metal or glass surfaces, as the polymer, on eliciting of the film--forming properties, will serve as adhesive to the limiting surfaces in question. In this way, both a cohesive and an adhesive effect are obtained in the heat treatment.
This may for example be utilized in the preparation of electrically isolating components which are to be arranged between limiting surfaces of metal, for example in the pre-paration of commutators in which the isolating material may be introduced in the form of a material of the invention and adhered to the metal limiting surfaces in a very simple and efficient way. ~nother utilization is the preparation of sandwich materials in which the composite materials of the invention may be used as "binder sheet" between for example two metal or glass plates.
When a hydraulic binder is incorporated as inorga-nic material in the composite material, it is us~ally not preferred to perform any pressing operation af-ter the hydraulic binder has hardened. Composite materials containing hydraulic binder may, according to the inven-S30 3 ~ -, ... . .
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tion, be -treated in -two dif~erent ways subsequent -to web formatiorl: Ei-the~, the cornposi-te ma-terial is drîed only to a stage which leaves sufficien-t water in the ma-terial for hardening -the hydraulic binder, and the harde-ning of the hydraulic binder is allowed to proceed, -the heat trea-tment being per~ormed subse~uen-t to the hardening of the hydraulic binder, bu-t wi-thou-t any substantial pressure applied during the heat -treatment, or the com-posite material is dried and hea-t-treated before the hydraulic binder hardens, whereaf-ter the hardening of the hydraulic binder is allowed to take place, ei-ther simply by exposing the composi-te ma-terial to ambient humidi-ty, or by posi-tively applying wa-ter to the compo-site material subsequen-t to the heat trea-tment.
In the products of -the present invention, the proportion of cellulose fibers may vary within wide li-mi-ts, from about 5% by weight to about 95% by weight, calcula-ted on dry weight of the material.
The produc-ts having a cellulose fiber content in the upper part of the interval, for example 95% cellulose fibers and 5% polymer material, may be paper- or cardboard-like materials, the streng-th and water resistence pro-perties of which are improved by the incorporated polymer material. If the polymer is one which easily fills all ca~ities, for example low density polyethylene, such composite materials, af-ter the heat treatment, may be used as water resis-tent or liquid-tigh-t packaging materi-als, for example for containers for beverages such as milk or juice. With proper selection of polymer, for example low density polyethylene, these ma-terials may be .: . , ~ , , ........... . . : .

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hea-t-~teldable, and b~ :incorporatlon of poly~ler ma-terials :improving -the s-treng-th proper-ties, for example polyester-coated fibers, very strong packaging materials may be ob-tained. ~lo~ther example of an in-teres-ting material for milk containers wi-th improved rigidity proper-ties is a composite ma-terial of -the inven~tion ln -the form of a la-minate with cemen-t and polymer ma-terial in the outer lay-ers thereof. If ma-terials of -this kind are to be coloured,~
a colour pigmen-t may be incorporated as an inorganic ma-terial in the way described above, or the polymer material may consis-t of a polymer applied on an inorganic colour pigmen-t as carrier, but the colouring may also be per-formed in conventional way af-ter -the sheet or web forma--tion. However, any colouring of the cellulose fibers should be performed prior -to -the final heat treatment, as the cellulose fibers would o-therwise become wholly or partially unavailable to the colouring treatmen-t. Any printing of the ma-terials should also prefereably be per-formed prior to the final heat treatment.
From webs having a high content of cellulose fibers, it is also possible to prepare products having propertias resembling of wood or hard wood fiber boards by subjecting one thick layer or several superimposed layers of the semi-finished product with a polymer suitable for this purpose to heat and pressure treatment. The material be-comes more compact and rigid, the higher pressure is ap-plied. Strength properties of a laminate of this type may be fur-ther improved by arranging the layers with alterna-ting fiber direction, that is, al-terna-ting manufacturing direction, like plywoodj and layers of other materials , . .
,~ . .

may also be :inc~ decl, f`or exarn~ple aluminum ~oil, lead foil, or composite ~a-teria:ls o:f dif-feren-t content, also sui-tably prepared acco-rding -to -the lnvention. The bonding be-tween -the layers of such laminate may be ob-tained sole-ly by the heat and pressure -treatment, -the polymer bonding toge-ther the layers. Lamination may also be utilized for preparing o-ther types of composite ma-terials of -the inven-tion, and a laminate be shipped as such for later hea~
treatment. A suitable composi-tion for a wood- or wood fiber panel-like produc-t is, for example, 85% o~ cellulose fi-bers and 15% of polypropylene particles or polyvinyl chlo-.
ride particles. If desired, part of -the cellulose fiber conten-t may be replaced with wood shavings or straw par-ticles, for example, -the composition may instead be 15%
of polypropylene particles, 60% of cellulose fibers and 25% of wood shavings or straw particles.
The products which, in addition -to cellulose fi-bers and polymer, con-tain an inorganic material, either incorporated as such or as the carrier in the polymer ma-terial, often have cellulose fiber contents in the ' range of 15 - ~5% by weight. Such materials are interes-ting semi-finished products for preparing a wide spec-trum of end products. Examples of these and similar materials are:
A composite material for preparing various ar-ticles which are conventionally prepared from polymer throughout or from other materials, for example system toy bricks or other shaped articles such as dishes, dispensable cutlery, rice bowls, serving trays, cartridge cases, packaging drums, district heating tubes, etc., may consist of about 30 ~ '70/0 by ~eight o~ cellulose fibers, about 40% by weigh-t ~f mineral wool fibers, and about 30/0 by weight of polymer ma-terial in which -the film-forming polyme~-is applied in an amount of about 15 - 40% by weight on mineral wool fibers. Thiis composite ma-terial as a single layer 3 a laminate, a wound-up s-tripe or an extrudate, may be conver-ted to the above-mentioned shaped articles by compressing with hea-t, for example at a pressure of 2 kg/c~2 - 10,000 kg/cm2, and a tempera-ture of abou-t 100C. (I-t applies quite generally -tha-t when eliciting the film-forming proper-ties of -the polymer materials, one should not employ temperatures above 170C for any longer period when it is desired to avoid any damaging of the cellulose fibers. However, brief (for example up to 60 seconds) heating to higher tempera-tures such as 250C
is usually tolerated.) When the shaped articles are to be coloured, pigment particles may be incorporated instead of part of the mineral wool fibers, or the polymer proper may be coloured. Surface smoothness and material strength of the finished shaped articles depend to a large extent on the shaping conditions: the higher pressure, the smoother surface and the better strength. Typical pres-sures are from 10 - 100 kg/cm2 and up to pressures of 1000 - 10,000 kg/cm2. By suitable selection of polymer, for example heat-curing polyester resin or melamin po-lyester with short curing time, a very short cyclus time in the die may be obtained. For system toy bricks, a suitable polymer will, for example, be ABS, epoxy or polyester, and a suitable polymer for dishes and rice bowls is a copolymerisate of melamin. A suitable polymer '. : - : . ~ ' . ~ , ' .
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for e ~g~ spectac~.e :r:rarnes, kn:i:f~ han~ s and ar-tificial -tee-th are for exarnpl~ ox~/ polyes-ter, po].yester or acrylic resin.
A s-trong struc-tura:L ma-terial for preparing for example lamina-te panels, boats, drums~ boards, chairs or automobile bodies may be composed of 15% by weight of cellulose fibers and 85% by weight o~ mineral wool fibers, covered by about 15% by weigh-t of polyester. The lamin~te-panels may be prepared in -the same way as described above, and they may be used for -the same purpose of ordinary commercial laminate panels, for example for in-terior walls, ki-tchen table tops, bathroom wall cover, etc. and they are advantageous in -that they are most simply prepared from cheaper star~ting ma~terials -than the conventional la-minate panels. For the preparation of for example boats, sheets or stripes of the semi-finished produc-t of -the invention in moistened condition may be shaped in the de-sired configuration, whereaf~er the eliciting of the film-forming properties of the polymer is performed under pressure (for example 100 kg/cm2) and heat.
A fibrous material, for example suitable for roo-fing felt and floor felt, may consist of 1~ - 20% by weight of cellulose fibers, 50 - 70% by weight of mineral wool fibers and 15 - 25% by weight of a polymer material which is, for example, glass, s-tone or slag wool fibers of lengths about 3 mm, or rovings with a coating of 15 - 20 % by weight of film-forming polymer or which is inorganic particles~ for example o`f sand or wollas-tonite, having a coating of 20 - 40% by weight of film-forming polymer.
Alternatively, the film-forming polymer could be present ~ .J

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as par-ticles consis^ting solely of -the polymer, the inor-ganic ma-terials mentioned -then being added per se, in which case the amoun-t of polymer will preferably be 5 - 10% higher.
A wear-resisting flooring ma-terial of -the inven-tion may consist of 15% by we:igh-t of cellulose fibers, 50% by weight of glass fibers and, as the polymer ma-terial, for example a combination of 20% by weight of polyvinyl chlo- --ride and 50% by weigh-t of polymer-coated mineral wool fibers.
A composite material for preparing hard, strong and electrical.ly insulating shaped ar-ticles, ~or example electrical isola-tors, including commutator materials, hair curlerbodies, printed circuits, etc., may, for exam-ple, contain about 15% by weight of cellulose fibers, suitably s-traw cellulose, and 85% of polymer material con-sisting of wollastonite particles of 5 - 200 /u with a coating of 10 - 50% by weight of polymer, for example a polyester or an epoxy polyester resin. On heat -treatment with or after high pressure, that is, pressures above 1000 kp/cm2, preferably above 4000 kp/cm2, an almost mi-neral- or stoneware-like, compact produc-t with high streng-th is obtained. Similar products may also be obtain-ed if -the wollas-tonite par-ticles and the polymer are in-corporated separately. Composite materials resembling these may also be prepared from powders of the mineral and polymer components in question, but the use of the composite material of the invention avoids all problems involving incompatibility or de-mixing. Also, the sheet or plate form blank of the composite material is easy to 3 ~

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- ~ - . . . -hand:Le, ar~ ror preparatiorl of shaped articles of greater thi.ckness, the co~npo~site ma-terial may be used in lamina-ted form, including rolls, or as an extru~ate. Also granu-lates may be used. Similar ma-terial ~or -the same field o~ use may, ~or example, consis-t of 20% by weigh-t of cel-lulose fibers 5 about 60% by weight of wollastonite powder having a par-ticle size ln the range of abou-t 5 - 200 /u (all powders used accord.ing -to -the in~en-tion preferabIy show a par-ticle size characteris-tic corresponding to -the grain curve of concrete) and 20% by weigh-t of a commercial particulate powder coating material consisting of epoxy.
resin on 43% TiO2 and 2% BaSOL~.
Hard, weather-proof and durable panel materials, for example for use as exterior panels on buildings, such as roof panels, may be prepared from a composite material..
containing 15 - 40% by weight of cellulose, the remainder being inorganic material and polymer, the polymer content being 15 - 40% b~ weight, and the content of inorganic material being 20 - 70% by weight. One example is a compo-site material having 35% by weight of cellulose fibers and 65% by weight of polymer material consisting of mineral wool fibers having a coating of 15% by weight of polyes-ter.
Various other composite materials suitable for this pur-pose are illustrated in Rxamples 1 - 24 and 45 - 54. One preferred roofing panel material comprises about 20% by weight of cellulose fibers, for example from cardboard, about 40 - 50% by weigh-t of inorganic particulate material, for example wollastonite or sand having a particle size below 300 /u, and about 30 - 40% by weight of polymer particles. The polymer particles may, for example, com-prise a relatively rigid polymer and a softer, to a grea-ter extent struc-ture-filling polymer. For example, the rela- 3 7 C' 7~ 7 ^. ~

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-tively rigid polymer rna~J be non-plasticized polyvinyl chlor~ide, and the other polymer in the combination may be pl~sticized polyvinyL chloride. Cross linked polye-thylene ls ano-ther good polymer for use in such roofing panel. In the preparation of roofing panels, -the composite material, either a single layer or a lamina-te of several layers (for example formed by web lamination of several webs, suitably by running suspension from several -tanks on one and the same wire, in which case there is suita-bly a larger content of polymer in the bo-ttom and top layers) is shaped in the desired configuration while still we-t, for example through corrugated rollers -to form corruga-ted roofing panels, whereafter the shaped panels may be dried, either in oven or between drying rollers, and thereaf-ter subjec-ted -to a temperature eli-citing -the film-forma-tion of -the polymer, for example 170C, if necessary or if desired under pressure, either between rollers or in a platen press.
A composite material which is suitable as backing for flooring materials, for example as backing for flooring e.g., polyvinyl chloride foam flooring,may beprepared from . ., ,, _ . . .
e.g. about 15 - 25, preferably about 20, % by weight of cellulose fibers, about 40 - 60~o by weight, preferably about 50% by weight, of mineral fibers, for example glass wool or stone wool, and about 30 - 40% by weight, preferably about 30 - 35% by weight, of polymer. Such backings have previously been prepared of asbestos fibers, but due to the health hazards associated wi-th asbestos fibers, it is necessary to find substitutes for asbestos-containing products. The present backing constitutes a , S38 3g ::
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: " ` ' ' ' climension-sta'ble, acceptable ancl compa-tible backing for polyvinyl chloride floorings. Examples of suitable poly-mers for -the purpose are polye-thylene, for example cross-linking polye-thylene, and polyvinyl chloride.
When the polymer is polyvinyl chloride, the backing may be "welded'i to -the remaining components of the polyvinyl chloride flooring concomi-ttantly with -the eliciting of the film-forming properties.
The composite ma-terial of -this inven-tion may also be used for preparing friction materials, for example brake linings. For this purpose, ma-terials are i.ncorpo-rated which are known to be suita'ble in friction mate- ~-rials, for example brass powder, barium sulphate, gra-phite, bronze powder, and wollastonite and Synopal or slag wool fibers. Composite materials suitable for brake linings are illus-trated in Examples 33 - 36. When prepa-ring materials for brake linings, it is especially pre-ferred that the fiber direction of the finished brake linings or brake bodies are, to the extent possible, perpendicular to their con-tact face. To this end 9 a laminate of several layers of friction ma-terial-con-taining composite ma-terial is made, -the fiber direc-tion being -the same in all the layers, the laminate is subjected to heat and pressure to elicit the film-forming properties of the polymer, and the resulting material is thereafter cut out into brake linings in a direction perpenclicular to the fiber orientation.

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In t~le below exanlples, perCe~nta~JeS are by we:igh-t unless othervise indicated.

Example A.

In a kneacler, 25% by weight o-f wollastonite powder (FW200 from Pargas, Finland) of par-ticle size 1 - 200/u were mixed with 75% by weight of a liquid polyester containing cross-linking agen-t and accelerator. The resulting mixture was extruded in a conventional plas-tic extruder which makes the polyester solidify. Thereaf-ter, the resulting material was treated in a hammer mill until 80% of the material had a par-ticle size of less than 70/u.
In a corresponding manner and from the same starting materials, powdery wollastonite/polyester materials were prepared with a content of 35% of wollastonite and 65% of the poly-ester, 45% of the wollastonite and 55% of the poly-ester, 70% of wollastonite and 30% of epoxypolyester, and 70% of wollastonite and 30% of polyurethane, respectively.

Example B.

In a mixer, 75% by weight of wollastonite powder (FW200 from Pargas, Finland) and 25% of particulate solid polyester of such particle size that 80% of the particles have a size of less than 70/u, were mixed. The energy appliecl through the mixing softened the polyester particles to such an .
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extent tlla~ part of them adhered to the wollastonl-te par-ticles.

Example C.

Flocculation in various sys-tems.

Flocculation experimen-ts were per~ormed with the below two starting recipes:

Recipe No. 1:
70 g cardboard (2% aqueous suspension, beaten to 38SR) 10 g polypropylene particles, particle siæe below 100/u 30 g wollastonite/polyester material, polyester content 75%, prepared as described in Example A
30 g wollastonite/polyester material, polyester content 65%, prepared as described in Example A
30 g wollastonite/polyester material, polyester content 55%, prepared as described in Example A.

Recipe No. 2:
70 g cardboard (2% aqueous suspension, beaten to 38SR) 10 g polypropylene particles, particle size below 100/u 30 g wollastonite/polyester material, polyester content 75%, prepared as described in Example A
30 g wollastonite/polyester material, polyester content 65%, prepared as described in Example A

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30 g wol]astonite/polyes-ter material, polyester content 55%, prepared as described in Example A
104 y wollastonite powder.

The above suspensions were used in a concentration of 0.2% in wa~er.
The experiments were perEormed in a 1000 ml graduated cylinder as follows:

1. Measure 1000 ml suspension.
2. Add flocculating agent.
3. Shake thoroughly.

4. Allow to s-tand on table, start timing.

5. Withdraw sample (at surface) and measure zeta potential and pH.

6. Record time (t400) when "precipitate" passes 400 ml line.

7. Record time (t200) when "precipitate" passes 200 ml line.
If 200 ml line is not passed within 10 minutes, the volume oE the precipitate is measured.

8. At t = 5 minutes, sample is withdrawn at 900 ml line for optical determination of water clarity (percentage trans-mission) in Beckman photometer. The first samples were not measured in photometer, for which reason no value for their percentage transmission is stated in the below table.

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Example D.

0.7 g Fintex 577, an "irreversible" cationic tens-ide of the -type quarternary ammonium compound, was mixed with 100 ml of water, and 10 g of a powder polymer ma-terial consisting of 55~ pol~ester applied on ~3% TiO2/2~ BaSO~, particle size ... . . _ .... . . .. ..
distribution 0.1/u - 30/u, was added. The resulting suspension was allowed to stand for 10 minutes. Thereafter, the aqueous phase was fil-tered off, and -the polymer material was dried in an oven at about 60C. The resulting polymer material coated with the irreversible tenside was added to 1.5 liter of an 1.5~ suspension of cellulose fibers in water. It was evident that a considerable attraction between the cellulose fibers and the polymer material was obtained, as the particles of the polymer materi~l flocculated together with the cellulose fibers.
The resulting suspension was applied on a sieve, 100 mesh.
The flocculate was retained on,the sieve, and the water passing the sieve was substantially free of polymer paxticles.

In the below examples terms not previously defined have the following meaning:

: :

Newspaper: Cellulose pulp prepared by beatiny old newspapers.
Cardboard: Cellillose pulp prepared by beating was-te cardboard.
Sulphate: Sulphate cellulose pulp.
Sulphite. Sulphite cellulose pulp.
SR: Schopper Riegler degree.
Wollastonite FW50: Wollastonite powder having a particle size of 1 ~ 500/u, from Pargas, Finland.
Wollastonite FW200: Wollastonite powder having a particle size of 1 - 200/u, from Pargas, Finland.
Synopal: Synopal (a synthetic mineral made from sand, dolomite, chalk, and aluminum-containing mineral) clust, par- i ticle size below 100/u.
Slag fiber, glass fiber RockwoOl ~ : In all cases fibers having a diameter of 5/u logarithmically distributed down to l/u and up to 30/u, length from 1 mm up to 10 mm, predominantly about 3 mm.
Polyester: Polyester powder from Emser Werke, Switzerland, 70% of the particles having a size below 80/u, the rest up to 200/u.
Polyester on ~'iO2/BaSO4: A co~mercial product from Pulver-coat, Germany, consisting of 559O of polyester applied on ~3% of TiO2/2% of BaSO2, particle size 30 -80/u.
Polypropylene: Particle size below 100/u.
Epoxy polyester: From Emser Werke, Switzerland, 80% of the part-icles have a size below 70/u, the remainder have a size of up to 200/u.
PVC: 80% of the particles have a size below 70/u, the re-mainder have a size of up to 200/u.

:, : .

~ .

' Urethane: Isonate ~ 123 P (caprolactame-blocked polymeric isocyanate), the Upjohn Company, Kalamazoo, Michigan.
Copo]yamide: Gril~tex ~ 2P, melt:ing temperature 120 - 130 C, a copolyamide with monolneric units of polyamide 12, poly-amide 6 and polyamide 6.6, from Emser Werke.
Particle size below 80/u.
Berol 373: A non-ionic tenside consisting of an alkylene oxide adduct based upon normal primary alcohol; the tenside has hydrophilic (water soluble) character. The pro-duct is a clear liquid with 100% active content.
From Berol Kemi AB, 4~01 Stenungsund 1, Sweden.

Instead of Berol 373 may also be used Triton CF10:

Triton CF10: Alkylphenoxypolyethoxyethanol from Rohm & Haas, Philadelphia, USA.
Nopco, NXZ: Antifoaming agent containing non-ionic emulsifier, from Nopco Chemical Company, 60 Bark Place, New Ark, New Jersey, USA.
Fintex 577: A cationic tenside of the type quaternary ammonium compound from Berol Kemi AB. This tenside is of "irreversible" character, that is, after having be-come attached to its substrate (single layer structure), it cannot be re-dissolved with water.

E9 ~ 8 - .

: .

Sancl: Danish beach sand, particle size below 300/u.
Cement, white: White Portland cernen-t; Blaine: 3400 cm2/g;
77 ~ 83~ C3S-Polyethylene, crosslinked: A product from Sigma, 67,3% of particles have size above 200/u.
PVC 3107/11/2: A plasticized produc-t (32% plas-ticizer -~ carbon black)-PVC 3085/92A/l: A non-plasticized (rigid) product.
PVC 3085/9lA/3: A plasticized produc-t (32% plasticizer).
PVC O-VI-107-1: A non-plasticized (rigid) product.
PVC 5 wsw 67-951: A plasticized product.

The above PVC products are all from British Industrial Plastics Limited, Darlington, England.
Retention: Assessed visually.
Water absorption, ~, day: Percentage weight increase after about 24 hours.

Examples l - 23 were all performed on a laboratory "sheet former", and all components were admixed in the vessel of the sheet former prior to starting the suction. The holding time in -the vessel after the mixing was about 5 minutes.
After sheet formation, the sheets were dried in a ventilated oven, and thereafter, the sheets were heet treated in a heated press.

ElO ~ 9 .. . . . , .;
. . . . . . . . .

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Example No. 1 2 3 4 5 Newspaper, %, 60 SR 30 Cardboard, ~, ~0 SR 25 Sulphate, %, 35 SR 15 15 Sulphite, ~, 35 SR 15 Wollastonite FW50, % 65 Wollastoni-te FW200, % 40 50 65 65 Polyester, ~ 30 25 20 20 20 Silan A 1100, % of inorg. 0.5 0.5 Dynasylan ~ GLY~O, ~ of inorg. 0.5 Volan, % of inorg. 0.5 Triethylamine % of inorg. 0.5 Prodefloc AC, % 0.5 0.5 0.5 0.5 0-5 Sheet weight g/m2 2000 2000 2000 2000 2000 Retention, % ......... 97-98 pH (adjusted) 6 6 6 6 6 Drying temperature, C 80 80 80 80 80 Heating temperature, C 190 190 190 190 190 Heating time, minutes 4 4 4 4 4 Heating pressure, kg/cm 40 40 40 40 40 Density, g/cm3 1.1 1.2 1.3 1.3 1.2 Annealing residue, % 41 51 66 66 66 Tensile strength, kg/cm 30 42 42 43 43 Water absorption, %, day 10 8 4 4 5 Water vapour absorption 6 5 2 2 3 at 85% relative moisture, %

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Example No. 6 7 8 9 10 _ Cardboard, ~, 40 SR 25 25 25 25 25 Wollastonite FW50, % 50 50 50 50 50 Polyester, % 25 20 20 o~o o Polypropylene, ~ 5 Epoxy polyester, % 25 PVC, %
_ _ Urethane, % 25 Silan A 1100, % of inory. 0.5 0.5 0.5 0.5 0.5 Prodefloc AC, % 0.5 0.5 0.5 0-5 0-5 Sheet weight, g/m2 2000 2000 2000 2000 2000 Retention, % ......... 97-98 pH (adjusted~ 5.5 5.5 5.5 5.5 5.5 Drying temperature, C 80 80 80 80 80 Heating temperature, C 190 190 200 190 200 Heating time, minutes 4 4 4 4 4 Heating pressure, kg/cm 40 40 40 40 40 Density, g/cm 1.3 1.3 1.3 1.3 1.3 Annealing residue, % 51 51 51 51 51 Tensile strength, kg/cm 42 45 50 36 48 Water absorption, %, day 9 6 9 8 6 . :

'~$~3~

Exc~mple No. ll 12 13 14 15 .
Cardboard, %, 40 SR 20 20 20 20 20 Wollastoni-te FW200, % 60 Synopal, % 60 Mineral wool, slag fibers, % 60 Mineral wool, glass fibers, % 60 Mineral wool, Rockwool, % 60 Polyester, % 20 20 20 20 20 Silan A llO0, % of inorg. 0.5 0.5 0.5 0.5 0.5 Prodefloc AC, % 0.5 0.5 0.5 0.5 (3.5 Sheet weight, g/m2 2000 2000 2000 2000 2000Retention, % 97 '-37 98 9~ '38 pH (adjusted) 5.5 5.5 5.5 5.5 6.5 Drying temperature, C 80 80 80 80 80 Heating temperature, C l90 190 l90 190 190 Heating time, minutes 4 4 4 4 4 Heating pressure, kg/cm 40 40 40 40 40 Densityj g/cm3 1.3 1.3 1.1 1.1 1.1 Annealing residue, % 61 61 61 61 61 Tensile strength, kg/cm 42 38 52 68 50 Water absorption, %, day 7 6 8 10 7 El3 . . .
~ ... . . . .
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Example No. 16 17 18 l9 20 . . _ Cardboard, %, 50 SR 20 20 20 20 20 Wollastonite FW50, ~ 43 43 43 43 43 Mineral wool, slag fibers,% 15 15 15 15 15 o\o Polyester, % 20 20 20 17 15 Polypropylene, % 3 5 Aluminum hydroxi.de, %
Ammonium phosphate, %
Berol 373, % 0.1 0.1 0.1 Nopco, NXZ, % 0.2 0.2 0.2 0.2 Silan A llO0, % oE inorg. 0.5 0.5 0.5 0.5 0.5 Triethylamine % oE inorg. 0.4 0.4 0.4 0.4 0.4 Prodefloc AC, % 0.4 0.4 0.4 0.4 0.4 Sheet weight, g/m 2000 2000 2000 2000 2000 Retention, % ......... 97-98 pH (adjusted) 5.5 5.5 5.5 5.5 5.5 Drying temperature, C 80 80 80 80 80 Heating temperature, C 190 190 190 190 190 Heating time, minutes 4 4 4 4 4 Heating pressure, kg/cm 40 40 40 40 40 Density, g/cm 1.3 1.3 1.3 1.3 1.3 Annealing residue, % 60 60 60 60 60 Tensile strength, kg/cm 44 44 46 46 47 Water absorption, %, day 7 7 6 6 6 . . . _ . . . _ . _ _ _ .

E14 ~ 3 .

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.

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Example No. 21 22 23 Cardboard, Q ~ 50 SR 20 20 25 Wollastonlte FW50, 'o 43 4~ 35 Mineral wool, slag fibers, 6 15 Polyester, 6 15 Polyester on TiO2 and BaSO~ 36 Copolyamide, 6 5 PVC, % 4 Aluminum hydroxide, ~ 1 Ammonium phosphate, %
Berol 373, % 0.1 Nopco, NXZ, % 0.2 Silan A 1100, % of inorg. 0. 50 . 5 Triethylamine, ~ of inorg. 0. 4 Prodefloc AC, 6 0 . 4 0 . 5 Prodefloc Cl % 0.1 Sheet weight, g/m2 2000 2000 Retention, % ... 97-98 pH (adjusted) 5.5 5.5 5.5 Drying temperature, C 80 80 80 Heating temperature, C 190 190 190 Heating time, minutes 4 4 4 Heating pressure, kg/cm 40 40 40 Density, g/cm 1.3 1.2 Annealing residue, ~O 60 59 Tensile strength, kg/cm 52 40 . _ . .. . . _ . . .
, . , ~' ''' ' ''' ', ., ~,~, ' ` " : ' ' ' , , Exc~mple 24.

In a full scale experiment on a paper making machine, the mixture use~ consisted of ~00 kg cardboard cellulose, beaten to 25SR, 500 kg o~ polyester material consisting of 55%
polyester applied on 43% TiO2/2% saSO~, particle size 30 - 80/u, 100 kg wollastonite ~'W200 and 5 liters of silan 1100. Prodefloc AC was continuously added in an amount cor-responding to 0.5%, calculated on the dry matter oE the recipe, and the point of addition for Prodefloc AC was in the tube from the overflow chest to the inlet chest. The vira of the paper making machine was from Nordiskafilt AB, "Vatvira" quality 6050/0 (double plastic vira), and vira velocity was 8 meters/
minute.
The cellulose was beaten in the normal way, and the polyester was added together with the wollastonite powder in the machine chest (100 m3) which was equipped with a powerful stirrer. The temperature of the cellulose pulp was about 50C, and its dry matter content was 2%. The dry matter content in the final sheet prior to rolling up was 50 - 55%. Sheet weights from 1200 g/m2 to 2000 g/m2 were prepared. An investigation of the final material by means of surface microscope showed that the wollastonite was evenly distributed in the sheet. The vira side did not have any greater content of wollastonite than the upper side. A
sample of this cardboard-like composite material was shaped ~: .
`
''' ' '.` `"

` : :
-and dried in corrucJated shape in a profile dryer, and the driedmaterial was compressed into corruga-ted panels in a smaller die a-t a pressure of about ~ kg/cm2 at a tempera-ture of about 170 C for 15 minutes. The resulting panel is excellently suited for use as a roof coating panel.

Example 25.

In a bakelite die, three layers of -the cardboard--like composite material prepared according to Example 24 were arranged on top of each other. At a pressure of 200 kg/cm2 and a temperature of 170C for about 15 minutes, there was prepared an excellent dish with sharp contours, good die release properties and a material character resembling that of glass fiber-reinforced polyester.

Examples 26 - 36.

These examples were performed on a pilot plant paper making machine. The same procedure as in Examples 1 - 24 was followed, that is, in the machine chest, cellulose pulp, polymer material and any inorganic additives were mixed, and the processing aids stated, except the flocculation ~6 ''~: , ' ' ' , . ~ ' ~: `
.' ':

ac3ents, were also added at this stacJe. The flocculating agents were added immecliately prior to the transfer of the suspension to the vlra. The data for these examples appear from the below table in whlch the various designations have the same meaning as in Examples 1 - 23. The barium sulphate ma-terial is barium sulphate powder having a particle size below 100/u, the brass powder has a particle size below 200/u. Instead of Hercufloc 829.3, also, for example, Hercufloc 853 may be used.

Example No. 26 27 28 29 30 31 32 33 34 35 36 Straw cellulose, 25 15 Sulphate, 80 20 17 20 15 2010 Sulphite, 90 15 Thermomechanic 95 cellulose fibers, G;ass flbers, % 60 55 Slag fibers, % 51.5 20 20 10 15 Rockwool fibers, 60 Wollastonite 15 10 10 FW200, %

: .`, . ~,.. ,~ . ., Example No. 2~ 27 28 29 30 31 32 33 34 35 36 ¦ Synopal, ~ 10 ¦ Barium sulphate, 25 10 10 o Brass powder, % 22 23 25 25 Polyester on 20 30 18 18 12 20 15 TiO2/BaS04 Polypropylene, % 5 20 Copolyamide, ~ 1020 3.5 10 Ammonium poly- 0.20.2 0.2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 phosphate Ammonium hy- 1.5 droxide Triton CF10 0.10.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Silan A 1100, 0.4 0.6 0.6 0.6 0.6 0.7 0.7 0.7 0.7 % of inorganic Nopco NXZ, 0.20.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 % of inorganic Alum, % 2.1 2.1 2 0.5 0.4 0.5 0.5 0.4 0.5 006 0.6 Prodefloc AC 0.50.3 0.5 0.6 0.7 0.4 0.5 0.5 0.4 0.6 0.5 Hercufloc 829.3 0.05 0.1 Prodefloc CL 2 0.5 .

While the materials prepared according to Examples 1 - 24 all show a relatively hard and plate-like character, subsequent to the release of the film-forming properties of the polymer, the materials prepared according to Examples 26 -28 show a pasteboard-like character subsequent to the film--formation of the polymer, but they show a better wet-strength ~J

El9 . . ~ , .
. ::

~',~ . ' ' than ordinary pasteboard. The materials prepared according to Examples 29 - 32 show a charac-ter like non-woven fabric (vlles), whereas the ma-terials prepared according to Examples 33 - 36 are suitable for ~Ise as ~riction ma-terials, especially for brake linings.
Instead of brass powder, bronze powder could be used, and instead of polyester applied on the inorganic carrier, non-carrier-containing polyester particles may be used and also epoxy polyester could be used. Instead of polypropylene, polyethylene can be used.

Example 37.

In the same manner as described in Examples 26 - 36, a composite material was prepared using 20% sulphate cellulose and 80% of a polymer material consisting of Rockwcol fibers having a coating of phenol formaldehyde resin polymerized to an extent of 80%, the resin constituting 3 - ~% of the po-lymer material. The resulting product is suitable for preparing hard boardlike panels and shaped articles by heat treatment at a pressure of 200 kg/cm2.
In another experiment, the same resin-covered Rockwool fibers were used in an amount of 85%, the amount of sulphate cellulose being 15%. A similar material suitable for the same purpose as above was obtained.

E20 ~ 9 :

, Example 38.

In the manner described in Examples 26 - 36, a composite material was prepared from -the following recipe:

About 200 liters of water 1350 g of sulphate cellulose 300 g of polyethylene powder (SA65), particle size about 300 - 500/u 0.2 ~ (3 g) oE Prodefloc Cl.

The sheet weight of the product was 228 g/m2. After drying, the product has slightly uneven, pasteboard-like character, . . .
and after releasing of the film-formation of the polymer under a pre~sure of 50 kg/cm2 for about 2 minutes, a uniform, parchment--like material of a good watertight cha.racter was obtained.

Example 39.

The procedure as described in Examples 26 - 36 was followed using the following recipe:

About 200 liters of water 1350 g of sulphate cellulose 300 g of pol~propylene (LM229), particle size 300 - 500/u J
~ .

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5 - 10% of a 1 solut:ion o:E Prodefloc AC
0.2~ (3 g) of Prodefloc C6.

The zeta poten-tial of -the resulting suspension was -6.0 millivolts, and the shee-t weight of the product was 268 g/m2. The product resembled the composite material prepared according to Example 33.

Example 40.

The procedure as described in Examples 26 - 36 was followed using the following recipe:

lO0 liter of water 675 g of sulphate cellulose ~` 150 g of polypropylene (LM229) about 5 % of 1% solution of Prodefloc AC
0.2 % (1.5 g) of Prodefloc C6 l/2 ml of Silan A llO0.

The sheetweight of the product was 316 g/m2.

Example 41.

The procedure as described in Examples 26 - 36 was followed using the following recipe:

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About 200 liter oE water lO00 g oE sulphate cellulose lO00 g of glass wool 800 g of polyester resin ~Polyester-Lack, 861-0984) 0.11 % (1.65 g) of Prodefloc Cl 0.89 % (1.35 g) of Prodefloc C4.

The suspension of water, sulphate cellulose, glass wool and polyester resin was initially run through a deflaker.
The pH of the suspension was 6.5, and the zeta potential was +4.6 millivolts. The sheet weight of the product was 330 g/m2.

Example 42.

The procedure as described in Example 41 was followed using the following recipe:

A~out 200 liters of water 500 g of sulphate cellulose 1500 g of glass wool ; 800 g of polyester resin (Polyester-Lack, 861-0984).

The above mixture was finely distributed in a deflaker.
Thereafter, 0.15~ (2.25 g) of Prodefloc Cl was added.

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The p~l of the suspension was 6.5, and the zeta potential was from -~4.0 millivolts to -9.2 millivolts.
The sheet weight of the product was 310 g/m .
The produc-t is, as the product preparecl according to Example 41, nice and uniform.

Example 43.

The same procedure as described in Examples 26 - 36 was followed using the following recipe:

About 200 liters of water 500 g o~ sulphate cellulose 1500 g of Rockwool ~ fibers, to which mixture was added a mixture of:
.. . .
800 g of grey epoxy powder (epoxy on 45% TiO2) 0.15 ~ or Prodefloc Cl (2.25 g) lO ml of Fintex 577 l liter of water.

The pH was 6.5, and the zeta potential was +6.8 millivolts.
The sheetweight of the product was 432 g/m2.

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Example 44, The procedure as described in -the previous examples was followed using the fol.lowincJ recipe:

About 100 liters of water 75 g of cellulose fibers (old cardboard, 42SR) 375 g of glass wool 519 g of polyester having a content of 35% w of wolla-stonite 606 g of ~ollastoniteFW50 10 g of tensideWKT
15 ml oE 1% Prodefloc Cl.

The pH was 7.0, and the zeta potential was -10.1 millivolts.

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, a Examples ~5 - 5~.

Examples 45 - 54 were all perEormed on a labora-tory "sheet former" as follows: Cardboard cellulose was beatenl sand was added to the resulting pulp, and thereafter polymer was added, said polymer havin~ been passed -through a sieve (430/u) in wet condition, and the resulting mixture was stirred for 2 minutes at 1000 r.p.m. Flocculating agent was added, and the stirring was continued for 15 - 20 seconds at 200 - 400 r.p.m. After this flocculation, the batch was poured into a vessel of a sheet former and was stirred for approximately 1/2 minute, and the suction was started. Aftex sheet formation, the sheets were dried in a ventilated oven and thereafter treated in a heat press.

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Example No. 45 46 47 48 49 .. ..... .
Cardboard, %, 50 SR 20 20 20 20 20 Sand, % 45 45 45 45 45 PVC (3107/11/2), % 85)* 80)~ 75)~ 70)* 65)*
)35 )35 )35 )35 )35 PVC (3085/92A/1), % 15) 20) 25) 30) 35) Prodefloc Cl, 0.125 0.125 0.125 0.125 0.125 % of inorg.
Sheet wëight, g/m2 3000 3000 3000 3000 3000 Retention, % ~100 ~100 ~100 ~100 ~100 Drying temperature, C 60 60 60 60 60 Hea-ting temperature, C 250 250 250 250 250 Heating time, minutes 1/2 1/2 1/2 1/2 1/2 Heating pressure, kg/cm 40 40 40 40 40 . . . _ .
~ Addition of 35% of a mixture of the two PVC's in the weight ratio indicated.

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Example No. 50 51 52 53 54 . Cardboard, ~, 50 SR 20 20 20 20 20 Sand, % 45 30 45 45 30 Cement, white 30 15 15 30 Polyethylene, cross- 15 20 20 O -linked, %
o r ~ PVC (3085/9lA/3), % 85) 85) )20 )20 PVC (O-VI-107-1), % 10 15) 15) . PVC (5WSW67-951), % 10 Prodefloc Cl, 0.125 2)~ 2)~ 2)~ 2)~
% of inorg. )0.125 )0.125 )0.125 )0.125 Prodefloc N2M 1) 1) 1) 1) Sheet weight, g/m 3000 3000 3000 3000 3000 Retention, % ~100 ~90 ~90 ~90 ~90 Drying temperature, C 60 60 60 60 60 Heating temperature, C 250 250 250 250 250 Heating time, minu-tes 1/2 1/2 1/2 1/2 1/2 Heating pressure, kg/cm2 40 40 40 40 40 ~ Addition of 20% of a mixture of the two PVC's in the weight percentage ratio indicated.

Addition of a total of 0.125% of the two polyelectrolytes in the weight ratio indicated. First, the two parts by weight of Prodefloc Cl was added, and thereafter, the one part by weight of Prodefloc N2M was added.

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Example 55.

A material for use as backing for polyvinylchloride flooring was made from cellulose fibers (20 - 40 SR) 20%
glass wool 50%
polyvinyl chloride (10 - 70/u) 30%
The cellulose fibers and the ylass wool were de-fibrila-ted separately in a beater.(me glass wool was beaten up to a 0.5% suspension in water with 0~01% of Prodefloc Cl added. Stirring was limi-ted to maximum 1 minute.) The suspen-sions were combined, and the polyvinyl chloride is added. Jwst before the inlet chest of the paper machine, 0.2% Prodefloc Cl was added, and the resulting flocculate was de-watered and the web was dried. The web is suitable for application of the polyvinyl chloride foam and the upper finishing coat of the flooring. The backing is able to suspend itself during the manufacturing, and the heat applied when combining the polyvinylchloride foam and upper finish bonds the backing `~ intimately to the foam.

Example 56.

Using the same procedure as in Example 55, a composite material was made from cellulose fibers 20% by weight glass wool 45% by weight PVC (3107/11/2) 80%) "' ) 35% by weight PVC (3085/92A/1) 20%J
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~3~1 Example 57.

Analogously to the procedu.re in Example 55, a composite material was made from cellulose 20%
glass wool 45%
cross-linking 35%
polyethylene Example 58.

Analogously to Examples 45 - 54, a material suitable for use as roofing panel was made from cellulose 20% by weight sand 45% by weight polyethylene, cross- 35% by weight.
linked Example 59.
.
A composite material suitable for preparation of roof plates was made as described in Example 45 ~ 54, from .
cellulose 4.8~ by weight glass wool 23.8% by weight wollastonite FW50 38.4% by weight polyester 33 % by weight.
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Example ~0.

Analoqously to Examples 45 - 54, a ma-terial suitable for use as a roofinq panel was made from cellulose 20% by weight sand 40% by weight PVC (3107/11/2) 85%) PVC (3085/92A/1) 15%) 40% by weight.

Example 61.

Analogously to Examples 44 - 53, a material suitable for use as a roofing panel was made from cellulose 20% by weight cement, white 20% by weight Sand 25% by weight PVC (3085/91A/3) 85%) PVC (0-VI-107/1) 15%) 35% by weight.

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Claims (23)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for preparing a composite material having a cellulose fiber structure in which the cellulose fibers are bonded together through hydrogen bonds, comprising preparing an aqueous suspension containing, in a non-flocculated state, a polymer material in the form of solid, discrete particles or fibers, having polymer at least at their surfaces, the polymer comprising one or more synthetic water-insoluble and water-non-swellable solid polymers which are non-sticky at room temperature and which fuse and are film-forming at temperatures above 80°C, and a cellulose fiber pulp; co-flocculating the polymer material and cellulose fibers by addition of a water-soluble synthetic polymeric polyelectrolyte flocculating agent, and immediately thereafter de-watering the resulting suspension to form a coherent material, and drying the coherent material under conditions which do not elicit the fusion of the polymer, the polymer of the polymer material being such that the polymer material remains in the form of substantially unfused discrete particles or fibers upon drying.

2. A process as claimed in Claim 1 and comprising the further step of subjecting the dried material to heat or to heat and pressure to fuse the polymer.

3. A process as claimed in Claim 1, in which an inorganic material in the form of mineral or metal particles or fibers is added to the aqueous suspension prior to co-flocculation.

4. A process as claimed in Claim 1, in which the polyelec-trolyte is added in an amount of 0.005 - 2% by weight of the constituents of the suspension to be flocculated.

5. A process according to Claim 3, in which an inorganic binder which hardens on absorption of water is incorporated as inorganic material and which further comprises subjecting C-l the dried material to conditions which fuse the polymer or which fuse the polymer and harden the inorganic binder.

6. A process according to Claim 1, in which the polymer material comprises 1) particles of the polymer having a particle size of 1-500/u, 2) particles of an inorganic carrier coated with the polymer, said particles having a particle size of about 1-500/u, 3) fibers of the polymer, or 4) inorganic fibers coated with the polymer.

7. A process according to Claim 1, in which the polymer is a polyolefin, vinyl polymer, polystyrene, polyimide, polyamide, polyacrylate, ABS Polymer, epoxy resin, epoxy/phenol resin, phenol resin, urea resin, melamine resin, polyester resin, melamine polyester resin, cross-linked acrylic resin, silicone resin, polyurethane resin or a copolymer thereof, or a synthetic vulcanizable elastomer.

8. A process according to Claim 7, in which the polymer is a synthetic vulcanizable elastomer SBR.

9. A process according to Claim 7, in which the polymer is a cross-linked synthetic polymer and a thermoplastic synthetic polymer or a cross-linked synthetic polymer, powdered bitumen or emulsion.

10. A process according to Claim 7, in which the polymer is a combination of a non-plasticized polymer and a plasticized polymer.

11. A process according to Claim 1, in which the polymer material comprises particles or fibers of an inorganic carrier material coated with the polymer.

12. A process according to Claim 11, in which said inorganic carrier material is selected from the class consisting of metal particles of brass, iron, zinc, aluminum, copper, or bronze;
and mineral particles of titanium dioxide, iron oxide, wollastonite, kaolin, de-glassed glass, calcium carbonate, quartz, silica, steatite, talc, aluminum, silicate, Synopal, barytes, diatomaceous earth, or amorphous silica.

13. A process according to Claim 11, in which the inorganic carrier material is selected from the class consisting of mineral fibers of glass wool, rovings, stone wool, slag wool, or kaolin wool and metal fibers of brass, copper, aluminum, bronze, or iron.

14. A process according to Claim 11, in which the polymer constitutes 2-20% by weight when the carrier is fibrous and 5-40% by weight when the carrier is particulate.

15. A process according to Claim 2, in which the polymer material contains a blowing agent which, under the temperature condi-tions at which the polymer is fused, simultaneously foams up the polymer to yield a cellular structure.

16. A process according to Claim 1, in which the composite material contains an anti-moisture impregnating agent which is a wood-protecting oil, a bitumen emulsion, a paraffin emulsion, or an oil emulsion containing a cationic tenside which is decomposed at temperatures of about 100°C.

17. A process according to Claim 3, in which the suspension comprises 15-40% by weight of cellulose fibers, 14-40% by weight of the polymer, and 20-70% by weight of inorganic material.

18. A process according to Claim 3, in which the inorganic material comprises metal particles selected from brass, iron, zinc, aluminum, copper, and bronze and mineral particles selected from TiO2, wollastonite, kaolin, de-glassed glass, calcium carbonate, quartz, including sand, silica, steatite, talc, aluminum, silicate, Synopal, barytes, diatomaceous earth, and amorphous SiO2.

19. A process according to Claim 18, wherein the polymer is polyvinyl chloride, a polyolefin, polyvinyl acetate or a polyamide.

20. A process according to Claim 17, in which the material used is a synthetic mineral fiber selected from glass wool, rovings, stone wool, slag wool, kaoline wool and calcium silicate wool or a metal fiber selected from brass, copper, aluminum, bronze and iron.

21. A process according to Claim 20, in which glass fibers are used as mineral wool fibers and polyvinyl chloride is used as the polymer.

22. A process according to Claim 3, in which the inorganic material is an inorganic binder capable of hardening on the absorption of water.

23. A process according to Claim 22, in which the inorganic binder is cement or kaolin cement.