IE61832B1 - Paper, cardboard or paperboard-like material and a process for its production - Google Patents

Abstract

A paper-like or cardboard-like raw material containing inorganic fibres, particulate inorganic additives and organic binders or flocculents is characterized in that (1) the particulate inorganic additives comprise 40-80 wt. % of the dry mass of the raw material; (2) the particulate inorganic additives contain (2.1) a basic filler of which at least 20 wt. % has a particle size < 2 mu m and not more than 20 wt. % has a particle size > 20 mu m and < 0.5 mu m, and (2.2) an anionic flocculating active pigment of which at least 50 wt. % has a primary particle size < 2 mu m; (3.1) the organic flocculant is a cationic polymeric carbohydrate with a mean molecular weight between 100 000 and 2 000 000 and a degree of substitution between 0.01 and 0.3 and amounts to 0.5 to 6 wt. % of the dry mass of the raw material; (3.2) 1000 g of basic filler may bind, with floc formation, not more than 0.1 mmol of cationic carbohydrate and 1000 g of anionic flocculating active pigment binds, with floc formation, at least 0.1 mmol of cationic carbohydrate.

Description

The present invention relates to a non-combustible paper, cardboard or paperboard-like material with a very high portion of inorganic constituents, namely inorganic fibres and inorganic particulate additives, i.e. fillers and pigments.

It is generally known that the strength of paper based on organic fibres is dependent on the formation of hydrogen bonds between the organic fibres. It is also know that by mechanically separating the fibres from one another the inorganic fillers reduce the fibre surfaces available for binding with hydrogen bonds or block the sites on the fibre capable of binding and replace them with weaker fibre-fillerfibre bonds, fine fillers reducing the strength very considerably.

Thus, if only inorganic fibres and fillers are used during manufacture of paper or paperboard-like materials, i.e. substances that are not capable of binding by hydrogen bonds, then the strength of the materials obtained is low.

Paper-like materials containing inorganic fibres, such as glass fibres or mineral wool fibres, inorganic particulate fillers, such as clay and bentonite, and hydrolysed starch as the organic binder are known from EP-A-0109782 and EP-A-0027705.

However, organic fibres are also used to improve strength and reduce brittleness.

DE-A-0109782 discloses the addition of at least 2% by weight of cellulose fibres but in which the proportion of the combustible constituents should not be higher than 10% by weight.

A process for the continuous manufacture of formed parts containing inorganic fibres, a silica sol and anionic starch is known from DE-A-26O6487.

However, these formed parts do not contain any inorganic particulate fillers.

EP-B-0080986 (AT-E-13777) discloses a process for manufacturing paper, according to which a product containing organic fibres, i.e. cellulose fibres, mineral fillers, anionic colloidal silicic acid and cationic guar is obtained. Mineral fillers are also understood to include glass fibres. On account of the high proportion of organic fibres, such a product is combustible and therefore is not suitable for high temperature applications.

A process for producing a porous inorganic sheet containing inorganic fibres and/or larger flock(s), an anionic silica sol and cationic starch is known from US-A—3253978. However, such a sheet does not contain any fine inorganic fillers and its strength is inadequate.

A fibrous material with low density which contains inorganic fibres, inorganic fillers and a high proportion of cationic guar is known from GB—A—2127867. The inorganic fillers are standard fillers that are used in relatively small quantities. Furthermore, borax is added to precipitate guar on the inorganic fibres.

A fibrous sheet material which contains inorganic fibres in a matrix of plastic clay (ball clay) is know from GB-A-2031043. To control the speed of dewatering, the material can also contain bentonite. Hydrolysable starch is used as the binder. Furthermore, the material contains a relatively high proportion of cellulose fibres.

Production of a thermal insulating material is known from US-A-3702279, in which inorganic fibres are mixed with a binder of an inorganic sol, whereupon the sol gels. This material does not contain any particulate inorganic additives. No organic binders are used. The material is sintered following drying.

The present invention is based on the object of providing paper, cardboard or paperboard-like material which, on the one hand, is non-combustible and, on the other hand, has high strength and flexibility and can be processed easily. Until now these properties were incompatible, i.e. until now it was considered necessary to use a relatively high proportion of Τθ organic fibres to manufacture fibrous materials of high strength and flexibility as well as good processibility, which of course increased the combustibility.

To achieve this object, the invention proposes non-combustible paper, cardboard or paperboard-like materials containing inorganic fibres, inorganic particulate additives and organic binders or flocculating agents, characterised in that (1) the particulate inorganic additives constititue 40-80% by weight of the material; (2) the inorganic particulate additives are composed of (2.1) a base filler of which at least 20% by weight has a particle size of <2μΐη and not more than 20% by weight has a particle size of >20μΐη, on the one hand, and <0.5pm on the other hand, and (2.2) an anionic flocculating active pigment of which at least 50% by weight has a primary particle size of <2μΐη, (3.1) the organic flocculating agent is a cationic polymeric carbohydrate with an average molecular weight of 100,000 to 2,000,000 and a degree of substitution of 0.01 to 0.3 and is present in a quantity of 0.5 to 6% by weight, based on the dry weight of the material, and (3.2) 1000 g of the base filler is unable to bind more than 0.1 mMol and 1000 g of anionic flocculating active pigment is able to bind at least 0.1 mMol cationic carbohydrate while flocculation is taking place.

The materials according to the invention are not combustible. They meet the requirements of DIN 4102, Class A. On account of their good strength properties the materials according to the invention can be easily processed further on the basis of cellulose fibres similar to paper, cardboard and paperboard. . The materials can be manufactured on conventional paper, cardboard or paperboard machines.

The good strength properties are surprising since the view was hitherto held that the strength values decrease drastically with high filler contents and increasing particle fineness. By comparison, the strength values of the materials according to the invention increase within wider limits with increasing quantities and increasing particle fineness of the particulate inorganic additives.

According to the invention no fibrous additives are included under particulate inorganic additives since the length of the fibres is generally in the order of millimeters. Particle size is understood to mean the largest dimension of a particle, which is important, for example, with flattened particles. The particles of the anionic flocculating active pigment sometimes tend to form relatively large agglomerates. According to the invention, particle size is therefore understood to mean the size of the primary particle.

The improvement in the strength properties presumably depends on the fact that the anionic flocculating active pigment and the cationic polymeric carbohydrate are absorbed; on the one hand, by the inorganic fibres and, on the other hand, by the inorganic particulate base fillers. The base filler particles settle on the surfaces of the fibres and in this way prevent the inherently smooth inorganic, fibres from sliding on one another, whereby a non-slip non-woven fabric is obtained. Inorganic fibres are incapable of developing strength either by binding with hydrogen bonds or through cross-linkage in combination with shrinkage, as is the case with plant fibres. The strength of a sheet made from purely inorganic fibres is based on '’adhering the individual fibres together at the contact points of the fibres with the aid of organic binders. A non-woven fabric of this type has relatively few fibre-fibre points of contact on account of the low flexibility of the inorganic fibres and in addition the retention of organic binder during dewatering in the conventional paper-making process is extremely low. The strength of the finished product is thus low.

On account of their surface size and structure as well as on account of their charge properties the base fillers used according to the invention can form flocks together with a suitable cationic * carbohydrate. The inorganic fibres are embedded by the filler during flocculation in the aqueous system. Consequently, according to the invention the number of contact points (fibre-fibre; filler-fibre; 3q filler-filler) as well as the retention of the carbohydrate is increased by the addition of the filler. Good structural strength is only achieved if all fibre-fibre intersection points possible are embedded by the filler completely and without defects oc and if the flocculating agent is evenly distributed.

This is only possible with suitably formed flocks. According to the invention, flocculation is controlled with the aid of the flocculating active pigments.

They can displace the point of flocculation on account of their anionic charge potential and, moreover, through formation of a microflock contribute together with the cationic carbohydrate to good distribution thereof. The anionic flocculating active pigments can, in addition, close defects in the filler-filler and fibre-filler bond.

The reaction mechanism described makes it clear that this is a very complex system in which synergistic effects can also occur. The individual components of the material according to the invention, i.e. fibres, base filler, anionic flocculating active pigment and cationic carbohydrate, must therefore be matched exactly to one another with respect to type and quantity added.

There are no limitations with respect to the inorganic fibres. It is the aim of the invention, however, to provide fibrous materials in which the potentially carcinogenic asbestos fibres are replaced by fibres unharmful to health. These include, among others, glass fibres, mineral fibres, silicic acid fibres, basalt fibres and/or aluminium oxide fibres. The thickness and length of the inorganic fibres can fluctuate within wide ranges. Preferably at least 80% of the inorganic fibres have a length in the range of approximately 1 to 6 mm. Mixtures of inorganic fibres which differ from one another with respect to composition, length and thickness can also be used.

There are also no limitations with respect , to the particulate inorganic base fillers. For example, SiO2, kaolin, aluminium oxide, fuller's earth, gypsum, calcium carbonate, titanium dioxide, zinc & oxide, perlite, vermiculite and/or other per se known paper fillers or fillers for synthetic materials and paints are suitable.

Some of these base fillers, such as gypsum and fuller's earth, give off water of crystallisation or adsorption water during heating and are in this way fire-retardant. Calcium carbonate, which gives off carbon dioxide at relatively high temperatures, has a comparable effect.

The content of inorganic base fillers generally amounts to 35 to 75% by weight, preferably 55 to 70% by weight, based on the dry weight of the material.

Preferably 35 to 99% by weight of the inorganic base filler has a particle size of <2^m and not more than 10% by weight has a particle size of >20pm.

The anionic flocculating active pigment is preferably aluminium hydroxide, bentonite or colloidal amorphous SiO2. The content of active pigments generally amounts to approximately 1 to 15, preferably 2 to 10% by weight, based on the dry weight of the material.

If an anionic colloidal amorphous SiO^ is used, then it is preferably used in the form of a 30-40% aqueous dispersion. Preferably anionic silica sols, which were obtained through contact of a diluted water glass solution with an acidic cation exchanger and ageing of the sol obtained, are used. They are dispersed in an alkaline medium which reacts with the silicon dioxide surface and there generates a negative charge. The particles repel one another on account of the negative charge and thus bring about stabilisation of the product. Suitable commercial products are available, for example, under the name Ludox (Trade Mark of the firm Du Pont), although other products can also be used.

If aluminium hydroxide is used as the active pigment, then it can be produced in status nascendi from an alkali aluminate and an acid, preferably sodium aluminate and sulphuric acid, or from an aluminium salt and alkali, preferably aluminium sulphate and caustic soda.

If bentonite is used as the active pigment, then alkali bentonite capable of swelling is preferred.

The ratio between inorganic particulate additives and cationic polymeric carbohydrate is preferably chosen so that there is no excess charge so that an optimum floe forms.

Preferred polymeric carbohydrates include cationic starch, cationic amylopectin, cationic galactomannan (for example, guar or cassia) and/or cationic carboxymethylcellulose. The carbohydrates can be cationised in a per se known manner in that the optionally hydrolysed initial carbohydrates are quaternised with quaternary ammonium compounds. The carbohydrates can, however, also be cationised following the dry cationisation process. Polyvinyl alcohols can also be added to the cationic carbohydrates.

The content of polymeric cationic carbohydrate as a rule amounts to 1 to 5, preferably 1 to 3% by weight, based on the dry weight of the material. This depends essentially on the desired field of application. If materials with a high temperature stability are to be produced, then small quantities of polymeric cationic carbohydrate are used. Materials for use at high temperatures include, for example, sealing materials used in chemical engineering and engine construction, as well as temperature-stable filter materials for hot gases and liquids.

Furthermore, with relatively high carbohydrate concentrations the materials according to the present invention can also be used as insulating materials during construction, particularly during dry construction, for example as cable routes and fire protection insulations, for fire doors, wall and ceiling panelling, support layers for heat-insulating materials, as well as fireproof displays for advertising purposes (in department stores). The construction of motor vehicles is another important field of application since, in addition to temperature stability, the materials according to the. invention have a low specific weight. Even with a relatively high content of cationic carbohydrate, the material does not ignite since the cationic carbohydrate merely carbonises.

The cationic polymeric carbohydrate generally has an average molecular weight of 200,000 to 1,000,000, preferably 300,000 to 800,000 and a degree of substitution of 0.15 to 0.02.

The materials according to the present invention can also contain cationic, anionic or non—ionogenic retention aids. As a rule, these retention aids are common in the paper industry and are preferably added in quantities of approximately 0.02 to 0.2% by weight, based on the dry weight of the material.

A cationic polyacrylamide with a molecular weight of approximately 1 to 10 million or a polyethylene imine with a molecular weight of approximately 80,000 to 300,000 can be used as the retention aid.

The materials according to the invention can also contain wet strength agents, preferably in a quantity of approximately 0.2 to 5% by weight, based on the dry weight of the material. Suitable wet strength agents are, for example urea formaldehyde or melamine formaldehyde resins, polyamide amine epichlorohydrin resins and the like.

The formation of materials according to the present invention as three-dimensional moulded bodies also forms the subject-matter of the present invention. These include tubes, casting shells, filter bodies, insulating walls, packing elements, etc.

The materials according to the invention are preferably manufactured by'· mixing an agueous dispersion of inorganic fibres and the particulate inorganic base fillers with an aqueous suspension of the active pigment and adding cationic polymeric carbohydrate to this mixture shortly before shaping. Shaping can be carried out, for example, on a paper or cardboard machine. This is referred to as sheet-making. The three-dimensional moulded bodies are preferably produced according to the fibrous casting process. It is also possible, however, to deposit the still damp sheet in a three-dimensional mould and dry it.

Shaping is preferably carried out after flocks have formed in the aqueous mixture following the addition of cationic polymeric carbohydrate.

Shaping is preferably carried out at the end of at least 10 seconds following the addition of cationic polymeric carbohydrate. The retention aid is preferably added following the addition of the cationic polymeric carbohydrate.

To obtain homogeneous products, the inorganic fibres and the inorganic base fillers are preferably subjected separately to wet dispersing prior to production of the dispersion, whereupon the separate dispersions are mixed with one another. Selection of a suitable stirring speed, duration of stirring, etc. ensures that each constituent is optimally dispersed. The dispersing parameters depend, for example, on the nature, length and thickness of the inorganic fibres or on the nature, particle size and specific weight of the base filler particles.

The aqueous dispersion of active pigments is then added to the mixed dispersion of inorganic fibres and inorganic base filler particles, whereupon the cationic carbohydrate is added shortly (approximately 10 to 30 seconds) before sheet-making. The retention agent is added subsequently.

The present invention will be explained on the basis of the following examples.

Examples 1 to 6 Glass fibres with long fibres (2-6 mm) is pre-dispersed in water. A separate pre-dispersion is then produced from mineral fibres with a fibre length of up to approximately 3 mm. The commercial product Inorphil (Trade Mark for the firm Laxa, Sweden) is used as the mineral fibre. The percentages by weight between glass fibres and mineral fibres are given in Table I. A dispersion of kaolin (base filler) is subsequently produced. The particle size and the percentages by weight of the types of kaolin used are likewise given in Table I.

The three pre-dispersions are thoroughly mixed with a dispersion of colloidal amorphous Sic>2. The water content of the dispersion amounts to approximately 60-70% by weight.

A solution of cationic starch (commercial product Amijel, Q-Tak 210 of the firm Cerestar) is then added (solids content of the solution = 1% by weight).· The percentages by weight of colloidal SiO2 and cationic starch are likewise given in Table I.

Flocks form following the addition of cationic starch. According to Example 6, a cationic polyacrylamide is also added as retention agent (Nalco 47-32; Trade Mark of the firm Nalco Chemical Co.) in the quantity given in Table I.

Approximately 20 seconds after the cationic starch is added, the aqueous substance is brought to a Rapid-Kothen laboratory sheet-making plant, whereupon the aqueous phase is sucked off. A sheet having a thickness of approximately 0.3 mm after drying is obtained. The tensile strengths of the test sheets are given in Table I.

Examples 1 to 6 show that, surprisingly and contrary to the level of knowledge in the paper, industry today, the strength increases sharply with the increasing base filler content and greater particle fineness with at the same, time very good retention values.

The comparative examples 1 and 3 already show the influence of the particle fineness, whereas comparative examples 3 and 4 show the influence of the filler content on mechanical strength.

Examples 2, 5 and 6 according to the invention show the increases in strength caused by the addition of the anionic flocculating active pigment, wherein the increased strength according to Example 5 over Example 2 is also caused by the higher proportion and the greater particle fineness of the base filler.

Example 6 shows that the strength can be increased even further compared with the material of the next comparable Example 5 by using a retention aid.

Examples 7 to 10 The fibre and filler pre-dispersions are produced according to Examples 1 to 6, the substances and weight ratios given in Table II being used.

Mixture of the pre-dispersions with the other constituents as well as sheet-making are likewise carried out according to Examples 1 to 6.

In Example 7 an aluminium hydroxide dispersion, which was produced in situ as aluminium sulphate and sodium hydroxide, is used as the active pigment instead of the colloidal amorphous silicic acid.

Bentonite is used as the active pigment in Example 8. Example 9 has been included as a comparative example (without active pigment).

Examples 7 to 10 are intended to illustrate the influence of the various flocculating active pigments on the strength properties of the non-combustible, inorganic materials according to the invention. The selection and quantity of flocculating active pigment depends to a large extent on the properties of the base filler. The requirements for non-combustibility sharply limit the quantity of organic auxiliary agents, such as carbohydrates, used. By adding active pigments to the base filler, the suspension is pushed into the most favourable flocculation range in each case and acceptable mechanical strength is only achieved thereby.

This is demonstrated by comparing the strengths of the materials according to Examples 1, 3 (Table I) and 9, in which no active pigment was used, with the respective values of the remaining examples.

Examples 11 to 15 Production of the pre-dispersions, mixture of the dispersions as well as sheet-making are carried out according to Examples 1 to 6. The individual substances and their percentages by weight are given in Table III. The Examples given in this Table show that various cationic carbohydrates can be used if they have a suitable degree of substitution (DS) and a suitable molecular weight.' In Example 15 a combination of two different carbohydrates is used which likewise results in suitable strength values.

Corresponding sheets in any thickness can also be manufactured on suitable paper or paperboard machines (endless wire or cylinder machine).

Depending on the formulation and the type of machine the total retention amounts to between 85 and 95%.

The specific weight can vary in the range of 500 to 3 1000 kg/m depending on the type and quantity of fibrous materials and fillers used. The insulating capacity and thus the range of applications depends primarily on the specific weight of the material produced, whereas the temperature stability is first of all directed to the melting point of the fibres.

In the formulation examples given, the glass fibres could be replaced by other fibres with a higher temperature stability without any difficulty and without detrimental effects on the mechanical properties.

TABLE I i 5 - Example No. 1 2 3 % 4 5 6 % by weigh t Mineral fibre (- 3 mm) 32.5 26.5 32.5 18.5 18.5 18.5 10 Glass fibre (2-6 mm) 15 .0 11.0 15 .0 9 .0 9.0 9.0 . Kaolin No. 1 Sheet structure ( 46% < 2 /im) 50.0 54.5 --- — — — — 15 Kaolin No. 2 Sheet structure (71% < 2 pi) ” — — 50.0 70.0 64.5 64.5 Colloidal amorphous SiO2 (particle size 15 - 20 nm) 5.5 5.5 5.5 20 Cationic starch Molecular weight 800,000 - 1 million DS: 0.05 2.5 2 -5 2.5 2.5 2.5 2.45 25 Cationic polyacrylamide (Nalco 47-32) 0.05 Tensile strength (MPa) 0-9 3 .8 2.3 4-0 5.3 5.6 TABLE II Example No. 7 8 9 10 % by weight Mineral fibre (- 3 mm) 26.5 26.5 26.5 26.5 Glass fibre (2-6 mm ) 11.0 11.0 11.0 11.0 Kaolin No. 2 Sheet structure (71% <2 /xm) 56.6 58.0 “* — Kaolin No. 3 Sheet structure (45% <2 /xm) 60.0 54.5 Aluminium sulphate 2.0 — -- — Sodium hydroxide 1 .4 — __ -- Bentonite — 2.0 — — Colloidal amorphous SiO2 (particle size 15 - 20 nm)· 5.5 Cationic starch Molecular weight 800,000 - 1 million DS: 0.05 2.5 2.5 2.5 2.5 Tensile strength 4.2 4.4 1.3 4.2 (MPa ) TABLE III Λ Example No. 11 12 13 14 % by weight Mineral fibre (- 3 mm) 19.0 27.0 27.0 18.5 Glass fibre (2—6 mm) 9.5 11.5 11 .5 9.0 Kaolin No. 2 Sheet structure ( 71% < 2 μτα) — — 54.5 54.5 — Calcium carbonate (99% <2 μ«ι) 68.0 — — 64.5 Alkali activated bentonite 2.0 -- __ -- Colloidal amorphous SiO2 (particle size 15 - 20 nm) 5.5 5.5 5.5 Cationic guar No. 1 DS; 0.11 1.5 — — — Cationic guar No. 2 DS : 0.02 -- 1.5 — — Cationic guar No. 3 DS : 0.1 — 1.5 — Cationic cassia Molecular weight 400,000 — — — — —. 2-5 Cationic starch Molecular weight 800,000 - 1 million DS: 0.05 Tensile strength (MPa ) 4.0 4.1 4.0 4.7 27.0 -Ο .0 .5 .0 .0 4.2

Claims (28)

1. A non-combustible paper, cardboard or paperboard-1 ike material containing inorganic fibres, inorganic particulate additives and organic binding or flocculating agents, characterised in that (1) the particulate inorganic additives constitute 40-80% by weight of the dry matter of the material;

2. (2) the inorganic particulate additives are composed of (2.1) a base filler, of which at least 20% by weight has a particle size of <2pm and not more than 20% by weight has a particle size of >20pm, on the one hand, and <0.5pm, on the other hand, and (2.2) an anionic flocculating active pigment of which at least 50% by weight has a primary particle size of <2pm. (3.1) the organic flocculating agent is a cationic polymeric carbohydrate with an average molecular weight of 100,000 to 2,000,000 and a degree of substitution of 0.01 to 0.3 and is present in a quantity of 0.5 to 6% by weight, based on the dry matter of the material, and (3.2) 1000 g of base filler is unable to bind more than 0.1 mMol and 1000 g of anionoic flocculating active pigment is able to bind at least 0.1 mMol cationic carbohydrate while flocculation is taking place.

2. A material according to Claim 1, characterised in that the quantity of particulate inorganic additives (1) amounts to approximately 50 to 75% by weight, preferably approximately 60 to 70% by weight, based on the dry matter of the material.

3. A material according to Claim 1 or 2, characterised in that the inorganic fibres are glass fibres, mineral fibres, silicic acid fibres, basalt fibres and/or aluminium oxide fibres.

4. A material according to any of Claims 1 to 3, characterised in that at least 80% of the inorganic fibres have a length in the range of 1 to 6 mm.

5. A material according to any one of Claims 1 to 4, characterised in I - 19 that the particulate inorganic base fillers (2.1) are SiC^, kaolin, aluminium oxide, fuller's earth, gypsum, calcium carbonate, titanum dioxide, zinc oxide, perlite, vermiculite and/or other per se known paper fillers or fillers for synthetic substances and paints.

6. A material according to any one of Claims 1 to 5, characterised in that the content of inorganic base fillers (2.1) amounts to 35 to 75, preferably 55 to 70% by weight, based on the dry matter of the material.

7. A material according to any one of Claims 1 to 6, characterised in that 35 to 99% by weight of the inorganic base filler (2.1) has a particle size of <2 pm and not more than 10% by weight has a particle size of >20 pm.

8. A material according to any one of Claims 1 to 7 characterised in that the anionic flocculating active pigment (2.2) is aluminium hydroxide, bentonite or colloidal amorphous SiC^.

9. A material according to Claim 8, characterised in that the aluminium hydroxide was obtained in status nascendi from a alkali aluminate and an acid, preferably from sodium aluminate and sulphuric acid, or from an aluminium salt and alkali, preferably from aluminium sulphate and caustic soda.

10. A material according to any one of Claims 1 to 9, characterised in that the ratio between the inorganic particulate additives (2) and the cationic polymeric carbohydrate (3) is such that there is no excess charge.

11. A material according to any one of Claims 1 to 10, characterised in that the cationic polymeric carbohydrate (3) is cationic starch, cationic amylopectin, a cationic galactomannan and/or cationic carboxymethyl cellulose.

12. A material according to any one of Claims 1 to 11, characterised in that the content of cationic polymeric carbohydrate (3) is 1 to 5, preferably 1 to 3% by weight, based on the dry matter of the material.

13. A material according to any one of Claims 1 to 12, characterised - 20 in that the cationic polymeric carbohydrate (3) is obtained by reacting the initial carbohydrate with a quaternary ammonium compound.

14. A material according to any one of Claims 1 to 13, characterised in that the cationic polymeric carbohydrate (3) has an average molecular weight of 200,000 to 1,000,000, preferably 300,000 to 800,000, and a degree of substitution of 0.15 to 0.02.

15. A material according to any one of Claims 1 to 14, characterised in that, in addition, it contains cationic anionic or non-ionic retention aids.

16. A material according to any one of Claims 1 to 15, characterised in that the retention aid is present in a quantity of approximately 0.02 to 0.2% by weight, based on dry matter of the material.

17. A material according to Claim 15 or 16, characterised in that the retention aid is a cationic polyacrylamide with a molecular weight of approximately 1 to 10 million or a cationic polyethylene imine with a molecular weight of approximately 80,000 to 300,000.

18. A material according to any one of Claims 1 to 17, characterised in that, in addition, it contains wet strength agents.

19. A material according to any one of Claims 1 to 18 in the form of a three-dimensional moulded body.

20. A method of preparing a material according to any one of Claims 1 to 14, characterised in that an aqueous dispersion of inorganic fibres and particulate inorganic base fillers (2.1) is mixed with an aqueous suspension of the active pigment (2.2) and the cationic polymeric carbohydrate (3) is added to this mixture shortly before shaping.

21. A method according to Claim 20, characterised in that the shaping is carried out after flocks have formed in the aqueous mixture following the addition of the cationic polymeric carbohydrate (3).

22. A method according to Claim 20 or 21, characterised in that the shaping is carried out at the end of at least 10 seconds following the - 21 addition of cationic polymeric carbohydrate (3).

23. A process according to any one of Claims 20 to 22, characterised in that a retention aid according to any one of Claims 15-17 is added 5 following the addition of the cationic polymeric carbohydrate (3).

24. A process according to any one of Claims 20 to 23, characterised in that the inorganic fibres and the inorganic base fillers (2.1) and active pigments (2.2) are subjected separately to wet dispersing prior 10 to production of the dispersion.

25. A process according to any one of Claims 20 to 24, characterised in that the material is prepared on a per se known paper, cardboard or paperboard machine or, if a three-dimensional moulded body is involved, 15 is manufactured according to the fibrous casting process or by deformation of a still moist fibrous web.

25. A method of preparing a material as claimed in Claim 20 substantially as hereinbefore described by way of Example.

27. A material whenever produced by a process as claimed in any of Claims 20 to 26.

28. A non-combustible paper, cardboard or paperboard-like material as 25 claimed in Claim 1 substantially as described herein with reference to the Examples.