EP0330635A1 - Substantially inorganic fibrous material and method for the production thereof - Google Patents
Substantially inorganic fibrous material and method for the production thereof Download PDFInfo
- Publication number
- EP0330635A1 EP0330635A1 EP89850055A EP89850055A EP0330635A1 EP 0330635 A1 EP0330635 A1 EP 0330635A1 EP 89850055 A EP89850055 A EP 89850055A EP 89850055 A EP89850055 A EP 89850055A EP 0330635 A1 EP0330635 A1 EP 0330635A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- sheet material
- talc
- weight
- soapstone
- inorganic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/36—Inorganic fibres or flakes
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
- D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
- D21H23/04—Addition to the pulp; After-treatment of added substances in the pulp
- D21H23/06—Controlling the addition
- D21H23/08—Controlling the addition by measuring pulp properties, e.g. zeta potential, pH
- D21H23/10—Controlling the addition by measuring pulp properties, e.g. zeta potential, pH at least two kinds of compounds being added
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/10—Organic non-cellulose fibres
- D21H13/12—Organic non-cellulose fibres from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/10—Organic non-cellulose fibres
- D21H13/12—Organic non-cellulose fibres from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H13/16—Polyalkenylalcohols; Polyalkenylethers; Polyalkenylesters
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/36—Inorganic fibres or flakes
- D21H13/38—Inorganic fibres or flakes siliceous
- D21H13/40—Inorganic fibres or flakes siliceous vitreous, e.g. mineral wool, glass fibres
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
- D21H17/42—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups anionic
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
- D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/63—Inorganic compounds
- D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
- D21H17/68—Water-insoluble compounds, e.g. fillers, pigments siliceous, e.g. clays
Definitions
- the present invention relates to a substantially inorganic fibrous sheet material, to a method for the production of such a sheet material by paper technology, and to a filler for the production of such a sheet material.
- paper technology is meant the technology used for papermaking, i.e. preparing an aqueous suspension or stock of the different constituents and dewatering the suspension, to form a sheet which is then subjected to drying and, optionally, to subsequent treatment, such as calendering.
- cellulose fibres are the principal constituent.
- Cellulose fibres are disadvantageous in so far as they impart to the sheet material inferior dimensional stability and a tendency to mildew. The sheet material therefore is unsuitable for use in, for example, humid environments.
- DK patent application 5436/76 it is previously known to prepare a composite material containing cellulose fibres, film-forming particulate or fibrous polymer material, polyelectrolyte, and optionally an inorganic particulate or fibrous material. Also this material has a high content of cellulose fibres (15-40% by weight), because of which the material does not satisfy the requirements for dimensional stability and resistance to moisture and mildew.
- the cellulose fibres of the sheet material have been but partly replaced by inorganic fibres.
- the wet strength is provided by the cellulose fibres which have a bonding effect by hydrogen bonds during formation of the paper web. Consequently, a rapid wet strength development requires rapid formation and dewatering, which also is advantageous in so far as it affords an opportunity to increase the production capacity.
- wet room wallpaper i.e. vinyl plastic layers on a backing material.
- the present invention aims at obviating the disadvantages of prior art materials and providing a material which is substantially inorganic, i.e. it consists to at least 50% by weight of inorganic material, and which is dimensionally stable and resistant to temperature changes, moisture and mildew.
- the present invention provides a substantially inorganic fibrous sheet material which is characterised in that it comprises
- the invention also provides a method for producing, by paper technology, a substantially inorganic fibrous sheet material, said method being characterised by forming a stock of
- the invention also provides a filler for the production of a substantially inorganic fibrous sheet material which is characterised in that the filler consists of a mixture of talc and soapstone.
- the inorganic filler is an especially characteristic and significant constituent.
- the inorganic filler of the invention is cationic and includes a mixture of talc and soapstone. Besides acting as a filler, the mixture of talc and soapstone acts as a dewatering controller, more particularly in order to provide a controlled slow dewatering.
- the filler contributes to creating a product which is "dead", i.e. a product which is dimensionally stable and does not change under the action of moisture and temperature changes.
- the function of the filler as a dewatering controller is due to the fact that, in contrast to conventional sheet material production by paper technology, the present invention does not require maximum dewatering, but instead a slower and controlled dewatering.
- the reason for this is that, because inorganic fibrous materials do not themselves contribute any wet strength, the present invention utilises the water of the sheet material suspension as an initial contributor to the wet strength. To this end, the water of the sheet material suspension must be retained until the sheet material has developed a sufficient dry strength through the binders added.
- the mixture of talc and soapstone utilised by the present invention has been found to possess unique and extremely advantageous properties for this purpose. The reason for this has not been fully explained.
- talc usually includes (a) the mineral talc, (b) steatite, which is a compact variant of talc, and (c) the rock type soapstone.
- the mineral talc is a hydrated magnesium silicate of the ideal composition Mg3Si4O10(OH)2.
- the talc content of commercial talc is high and usually lies at about 97% by weight.
- talc mineral is crushed and comminuted and then purified by flotation to provide a talc product having a high talc content and whiteness.
- Soapstone is a natural product consisting mineralogically of talc in mixture with a high content of chlorite and minor amounts of carbonate and amphibole.
- soapstone from Handöl in Sweden has the following mineral composition talc about 67% by weight chlorite about 18% by weight carbonate about 8% by weight amphibole about 3% by weight ore material about 4% by weight
- the talc and the soapstone in the filler mixture of the invention should have different mean particle sizes.
- the talc is coarse grained and has a mean particle size of about 10-20 ⁇ m
- the soapstone is fine grained or micronised and has a mean particle size of about 5-10 ⁇ m.
- the relative proportions of talc and soapstone in the filler mixture of the invention may vary within wide limits, preferably from a weight ratio of about 30:70 to about 70:30, more preferred from about 40:60 to about 60:40, and most preferred about 50:50.
- the filler content in the sheet material of the invention may also vary within wide limits, but is preferably about 1-80% by weight, more preferred 45-70% by weight.
- the sheet material of the invention also contains cationic inorganic fibres.
- the content of inorganic fibres in the sheet material may vary within wide limits, but is preferably about 1-80% by weight, more preferred about 20-40% by weight.
- the inorganic fibres may be freely selected among existing inorganic fibres, provided that they are cationic, i.e. have a positive charge. If the inorganic fibre is not cationic in itself, it can be made cationic by subjecting the fibre in per se known manner to a surface treatment such that the fibre will obtain a positive surface charge.
- the inorganic fibres are mineral fibres, and most preferred are glass fibres.
- the fibre length and diameter are not critical, but it is preferred that the mean fibre diameter is within the range 1-20 ⁇ m, and that the mean fibre length is in the range 2-20 mm, preferably 5-15 mm.
- the sheet material according to the invention may comprise, as a further cationic constituent, a cationic polyelectrolyte in a content of up to about 2% by weight.
- a polyelectrolyte is a polymer having the character of an electrolyte, which means that, like an electrolyte, it is dissociated in aqueous solution in ions and is electrically conductive. Depending on whether the polymer main chain is positively or negatively charged upon dissociation, the polyelectrolyte is said to be cationic or anionic, respectively.
- the starting material of cationic polyelectrolytes are derivatives of esters and amides.
- a characteristic feature of these polyelectrolytes is an ammonium group which may be present in the form of a salt of tertiary amine, or as a quaternary ammonium group.
- the starting material for anionic polyelectrolytes usually is acrylic and methacrylic acid.
- the cationic polyelectrolyte together with the remaining cationic constituents, i.e. the inorganic filler and the inorganic fibres, serves to balance the negative charges of the anionic constituents of the sheet material.
- balancing of the positive and negative charges to obtain charge neutrality can be attained by suitable adjustment of the amounts of inorganic filler and inorganic fibres, and the cationic polyelectrolyte therefore is no indispensable constituent of the sheet material according to the invention.
- the cationic polyelectrolyte is preferably added in repeated doses.
- the cationic polyelectrolyte can be selected among any available polyelectrolytes of this type, and since these are per se well known, no detailed enumeration would here seem necessary.
- the sheet material also contains anionic constituents in an amount such that they form, together with the cationic constituents, a charge-neutral system.
- the anionic constituents include a binder comprising an anionic polyelectrolyte and, optionally, also cellulose fibres.
- anionic polyelectrolytes as dispersing and flocculating agents is previously known, but the inventor is not aware that they have been used before as a binder or, as in the present invention, added to an aqueous suspension or stock in order to develop dry strength in the sheet material formed.
- the anionic polyelectrolytes are in the form of diluted aqueous solutions having a concentration of about 10-35% by weight. Since anionic polyelectrolytes are per se well known, a detailed enumeration thereof would not seem necessary. As examples, however, mention may be made of the flocculating polymers commercially available under the trade name Prestol, for example Prestol 2935/74 which is manufactured by Stockhausen, and of the anionic polyelectrolyte Prodefloc N2M from the company Prodeco in Italy, and PLEX 4911 from the company Röhm GmbH. In the sheet material according to the invention, the content of anionic polyelectrolyte suitably is 3-20% by weight, preferably about 5-10% by weight.
- the sheet material according to the invention may optionally contain cellulose fibres to improve the dry strength of the material.
- a high content of cellulose has a negative effect on the dimensional stability of the sheet material and its resistance to moisture and mildew, for which reason the cellulose fibre content of the invention is maintained as low as possible, such as at most about 8% by weight, preferably at most about 5% by weight.
- the cellulose fibres are preferably added in a content of about 2-5% by weight, more preferred about 4-5% by weight.
- the cellulose fibres can be left out completely. This is different from prior art technique which generally uses cellulose fibres in contents of 30% by weight and more.
- the cellulose fibres of the present invention furthermore are not long, but have preferably been thoroughly beaten to a dewatering resistance of about 75-100° Schopper-Riegler (°SR).
- the sheet material of the invention also contains a strength-improving additive including thermoplastic polymer particles.
- a strength-improving additive including thermoplastic polymer particles.
- particles are here meant not only granules, but also flakes and fibres.
- the strength-improving additive is intended to impart dry strength to the sheet material in that the thermoplastic polymer particles during sheet production in, for example, the drying section or in a hot-calender are heated to cause them to sinter or fuse together at their contact or crossing points, while substantially maintaining their original configurations, such that the particles form a coherent three-dimensional network structure or reinforcement imparting dry strength to the sheet material.
- thermoplastic polymer particles are preferably included in a content of about 2-20% by weight in the sheet material according to the invention.
- thermoplastic polymer particles are not especially critical, and they may be for example anionic or nonionic, but it is especially preferred that they are nonionic.
- the thermoplastic polymer particles can be freely selected among available thermoplastic polymer particles or mixtures thereof. However, since the temperature in the drying section of the paper machine used for the production of the sheet material, and also in the hot-calender, lies at about 70-120°C, the thermoplastic polymer particles should be allowed to soften within this temperature range, preferably at about 70-80°C.
- An especially preferred thermoplastic polymer in the context of the invention is polyvinyl alcohol. Among other useful thermoplastic polymers, mention may be made of polyethylene, polypropylene, polyvinyl chloride, polyester and polycarbonate.
- thermoplastic polymer particles may be in the form of fibres.
- the fibre dimensions are not critical, but it is preferred that they have a mean length of about 0.6-12 mm, preferably about 1-6 mm, and a weight length of about 0.5-10 dtex, preferivelyably about 1-6 dtex.
- the sheet material according to the invention normally has a thickness of about 0.1-1.5 mm, preferably about 0.1-0.5 mm, and most preferred about 0.15-0.25 mm, but greater thicknesses can be obtained without difficulty by multi-layer techniques (using for example several head boxes).
- the sheet material is produced by paper technology, and since paper technology is a well-known and well-established technique, it would not seem necessary to give a detailed description of this technique and the equipment utilised. Instead, the description hereinafter is drawn to the characteristic features of the invention, i.e. the method by which the components are combined to form the sheet material, and the sequence in which this is done.
- the inorganic fibres preferably surface-treated glass fibres according to the above, are slushed in water.
- the glass fibre concentration preferably is about 1% by weight since the fibres in higher concentrations, for example above about 3% by weight, tend to form lumps.
- the inorganic filler which includes a mixture of talc and soapstone according to the above, is added to the glass fibres suspension, and preferably cellulose fibres are added as well to contribute to the strength of the material.
- anionic polyelectrolyte is added to the resulting slurry or stock.
- charge neutrality can be achieved in principle by relative adjustment of, on the one hand, the amounts of the anionic polyelectrolyte and any cellulose fibres present and, on the other hand, of the cationic inorganic filler and the cationic inorganic fibres. Such adjustment can be conveniently carried out during batchwise production of the sheet material according to the invention.
- the first batch is preferably added to the stock after the anionic polyelectrolyte has been added, whereupon the second batch is added immediately ahead of the head box.
- the major part of the cationic polyelectrolyte for example 60-95% by weight, preferably about 85-95% by weight, is added with the first batch.
- nonionic thermoplastic polymer particles such as the nonionic polyvinyl alcohol particles preferred according to the invention, the system must be charge-neutral if one is to obtain uniform distribution of the nonionic thermoplastic polymer particles.
- one or more additives known in paper technology such as hydrophobating agents, antifoaming agents, colourants, optical brightening agents, retention agents and lubricants, may be added as well.
- the aqueous suspension or stock has a suitable ionic strength that can be controlled by means of alkali or alkaline earth salts, such as sodium, magnesium or calcium salts, of which calcium salts, such as calcium chloride, give the best result.
- alkali or alkaline earth salts such as sodium, magnesium or calcium salts, of which calcium salts, such as calcium chloride, give the best result.
- the salt addition reduces the repulsion of the electric double layer between the less charged surfaces of the upper and lower sides of the filler particles.
- the calcium ion content is supplied by the water hardness which should be about 18-26° dH (German hardness), but if the water hardness is unsuitable, it is adjusted by adding a calcium salt so that the calcium content will be about 7-18 mol/m3 H2O, which corresponds to about 0.4-1.0 kg CaCl2/m3 H2O.
- the stock is run through the head box onto the wire and conducted through the press and drying sections of the paper machine in conventional manner.
- the first part of the drying section is heated to maximum temperature (about 90-120°C) to quickly achieve dry strength of the sheet material.
- the second part of the drying section should have a lower temperature (about 60-70°C).
- the strength-improving thermoplastic polymer of the sheet material should be selected such that it begins to soften on the surface at about 70°C, whereby the thermoplastic particles are bonded together at the crossing points during treatment in the drying section and the hot-calender.
- the thermoplastic particles should not, however, melt completely and flow into each other at the temperatures used in the drying section and the hot-calender, respectively.
- the sheet material according to the invention has a variety of applications, for example in wall, floor and roof covering materials (e.g. in roofing felt), and in foamed products, such as polyurethane, polyvinyl chloride and phenol plastics.
- the sheet material according to the invention may be included as a carrier or backing material, but may also be included as, for example, an intermediate layer, or be used separately.
- the sheet material according to the invention contains, as mentioned above, at least 50% by weight of inorganic material.
- the sheet material contains 70-80% by weight or more of inorganic material, and so far as the inventor is aware it has not previously been possible, by using paper technology, to produce sheet materials with these high contents of inorganic fibres and fillers.
- the soapstone used in the Examples was of type H340 from Handöl, Sweden. This is a micronised soapstone having a mean diameter of 5-10 ⁇ m.
- the talc content is about 67% by weight, and the loss on ignition about 8% by weight.
- the oil absorption value is 55 g oil/100 g soapstone, and the melting point is 1500°C.
- the talc used in the Examples was of the type Finntalk P40 from Outokumpu Oy, Finland, which has a mean diameter of about 10-20 ⁇ m, a talc content of about 97% by weight, a loss on ignition of 7% by weight, and an oil absorption value of 32 g oil/100 g talc.
- the melting point is 1375°C.
- thermoplastic particles used in the Examples were polyvinyl alcohol flakes of the type Moviol from Hoechst and polypropylene fibres of the type Pulpex P from Herkules. TABLE 1 Examples 1 2 3 Glass fibres (cationic, length 10 mm, diameter 3 ⁇ m) 20 35 29 Soapstone 40 33 25 Talc 28 13 25 Cellulose (long-fibre pine sulphate cellulose which has been beaten and bleached, 95°SR) 4 6 - Cationic polyelectrolyte (ROHAFLOC KL 925 from Röhm) 0.5 1.0 - Anionic polyelectrolyte (PLEX 4911 from Röhm) 5 7 10 Thermoplastic particles (PVA) 2.5 5 11
- the anionic polyelectrolyte is added, and the system now begins to turn into a charge-neutral system.
- the cationic polyelectrolyte is added in several (two) doses.
- the thermoplastic particles are added to the charge-neutral system.
- the resulting slurry or stock is supplied to the paper machine, and the water is sucked off immediately ahead of the drying section.
- the first part of the drying section has been heated to maximum temperature (about 90-120°C) to rapidly increase the dry strength of the sheet. After the drying section, the sheet is hot-calendered at a pressure of 23 N/mm.
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Paper (AREA)
- Inorganic Fibers (AREA)
- Reinforced Plastic Materials (AREA)
Abstract
- (a) cationic inorganic fibres,
- (b) a cationic inorganic filler including a mixture of talc and soapstone,
- (c) an anionic binder including an anionic polyelectrolyte and, optionally, cellulose fibres, and
- (d) strength-improving additives including thermoplastic polymer particles.
Description
- The present invention relates to a substantially inorganic fibrous sheet material, to a method for the production of such a sheet material by paper technology, and to a filler for the production of such a sheet material.
- By "paper technology" is meant the technology used for papermaking, i.e. preparing an aqueous suspension or stock of the different constituents and dewatering the suspension, to form a sheet which is then subjected to drying and, optionally, to subsequent treatment, such as calendering.
- In the conventional production of fibrous sheet materials, cellulose fibres are the principal constituent. Cellulose fibres are disadvantageous in so far as they impart to the sheet material inferior dimensional stability and a tendency to mildew. The sheet material therefore is unsuitable for use in, for example, humid environments.
- It is known to partly replace the cellulose fibres of such sheet materials by inorganic fibres and fillers. The constituents are bonded together in conventional manner by stock sizing or by application of a binder in a size press, or by a combination thereof.
- Thus, it is previously known from European patent application 78850011.4 (Publication No. 1539) to produce a carrier material in the form of a fibrous mat by proceeding from mineral fibres and cellulose fibres in an aqueous suspension which also contains an acrylate binder. After the suspension has been dewatered on a wire, the sheet thus formed is pressed and dried, whereupon a binder in the form of a styrene-butadiene latex is added. One disadvantage of this known material is that the styrene-butadiene latex splits off formalin, and furthermore the high cellulose fibre content of the material makes it unstable against moisture and mildew.
- From DK patent application 5436/76 it is previously known to prepare a composite material containing cellulose fibres, film-forming particulate or fibrous polymer material, polyelectrolyte, and optionally an inorganic particulate or fibrous material. Also this material has a high content of cellulose fibres (15-40% by weight), because of which the material does not satisfy the requirements for dimensional stability and resistance to moisture and mildew.
- In the above-mentioned prior art technique, the cellulose fibres of the sheet material have been but partly replaced by inorganic fibres. One reason why a relatively high content of cellulose fibres in the sheet material was retained, in spite of the disadvantages in respect of inferior dimensional stability and resistance to moisture and mildew, is that the material must have a given wet strength to make its production by paper technology possible. In conventional papermaking, the wet strength is provided by the cellulose fibres which have a bonding effect by hydrogen bonds during formation of the paper web. Consequently, a rapid wet strength development requires rapid formation and dewatering, which also is advantageous in so far as it affords an opportunity to increase the production capacity.
- However, this aspiration for a rapid dewatering has caused difficulties in the production of sheet materials containing inorganic fibres, such as glass fibres because inorganic fibrous materials do not develop hydrogen bonds and therefore do not themselves contribute any bonding strength. Rapid dewatering thus gives an inferior wet strength, and to set this right it has therefore been necessary to retain, in prior art technique, a relatively high content of cellulose fibres in the material, and furthermore wet strength agents in the form of, for example, melamine resins were added.
- One application where the requirements placed on the material are especially high are wall materials for bathrooms or laundry-rooms, so-called wet room wallpaper, i.e. vinyl plastic layers on a backing material.
- This type of wall material is difficult because it is set up with the lengths in edge-to-edge relationship and welded by means of a joint sealing liquid. After that, the wallpaper is not allowed to move under the action of moisture and/or heat because the wallpaper will then bulge out and detach itself from the wall so that the joint opens out in an unattractive manner, permitting moisture to penetrate behind the wallpaper. Earlier backing materials consisted of paper, but this has now been replaced by nonwoven glass fibre materials resistant to moisture and mildew. Nonwoven glass fibre material, on the other hand, suffers from the disadvantage that the vinyl plastic must be applied in at least two steps - priming (sealing) and finishing - because the vinyl plastic will otherwise flow through the nonwoven glass fibre material. The two-step application means a considerable rise in price. Besides, many people dislike working with nonwoven glass fibre materials since they are apt to cause skin irritations.
- The present invention aims at obviating the disadvantages of prior art materials and providing a material which is substantially inorganic, i.e. it consists to at least 50% by weight of inorganic material, and which is dimensionally stable and resistant to temperature changes, moisture and mildew.
- This is achieved, in accordance with the invention, by a unique combination of constituents and steps for making a sheet material therefrom.
- More particularly, the present invention provides a substantially inorganic fibrous sheet material which is characterised in that it comprises
- (a) cationic inorganic fibres;
- (b) a cationic inorganic filler including a mixture of talc and soapstone;
- (c) an anionic binder including an anionic polyelectrolyte and, optionally, cellulose fibres; and
- (d) strength-improving additives including thermoplastic polymer particles.
- The invention also provides a method for producing, by paper technology, a substantially inorganic fibrous sheet material, said method being characterised by forming a stock of
- (a) cationic inorganic fibres;
- (b) a cationic inorganic filler including a mixture of talc and soapstone;
- (c) an anionic binder including an anionic polyelectrolyte and, optionally, cellulose fibres; and
- (d) strength-improving additives including thermoplastic polymer particles,
- The invention also provides a filler for the production of a substantially inorganic fibrous sheet material which is characterised in that the filler consists of a mixture of talc and soapstone.
- Further characteristic features of the invention will appear from the following description and the appended claims.
- Among the constituents of the sheet material according to the invention, the inorganic filler is an especially characteristic and significant constituent. The inorganic filler of the invention is cationic and includes a mixture of talc and soapstone. Besides acting as a filler, the mixture of talc and soapstone acts as a dewatering controller, more particularly in order to provide a controlled slow dewatering. Moreover, the filler contributes to creating a product which is "dead", i.e. a product which is dimensionally stable and does not change under the action of moisture and temperature changes.
- The function of the filler as a dewatering controller is due to the fact that, in contrast to conventional sheet material production by paper technology, the present invention does not require maximum dewatering, but instead a slower and controlled dewatering. The reason for this is that, because inorganic fibrous materials do not themselves contribute any wet strength, the present invention utilises the water of the sheet material suspension as an initial contributor to the wet strength. To this end, the water of the sheet material suspension must be retained until the sheet material has developed a sufficient dry strength through the binders added. The mixture of talc and soapstone utilised by the present invention has been found to possess unique and extremely advantageous properties for this purpose. The reason for this has not been fully explained.
- The generic term "talc" usually includes (a) the mineral talc, (b) steatite, which is a compact variant of talc, and (c) the rock type soapstone.
- The mineral talc is a hydrated magnesium silicate of the ideal composition Mg₃Si₄O₁₀(OH)₂. The talc content of commercial talc is high and usually lies at about 97% by weight. For the production of commercial talc, talc mineral is crushed and comminuted and then purified by flotation to provide a talc product having a high talc content and whiteness.
- Soapstone is a natural product consisting mineralogically of talc in mixture with a high content of chlorite and minor amounts of carbonate and amphibole. For example, soapstone from Handöl in Sweden has the following mineral composition
talc about 67% by weight chlorite about 18% by weight carbonate about 8% by weight amphibole about 3% by weight ore material about 4% by weight - For maximum results in respect of dewatering and wet strength, the talc and the soapstone in the filler mixture of the invention should have different mean particle sizes. Thus, it is preferred that the talc is coarse grained and has a mean particle size of about 10-20 µm, while the soapstone is fine grained or micronised and has a mean particle size of about 5-10 µm. The relative proportions of talc and soapstone in the filler mixture of the invention may vary within wide limits, preferably from a weight ratio of about 30:70 to about 70:30, more preferred from about 40:60 to about 60:40, and most preferred about 50:50. The filler content in the sheet material of the invention may also vary within wide limits, but is preferably about 1-80% by weight, more preferred 45-70% by weight.
- In addition to the especially characteristic cationic, inorganic filler described above, the sheet material of the invention also contains cationic inorganic fibres. The content of inorganic fibres in the sheet material may vary within wide limits, but is preferably about 1-80% by weight, more preferred about 20-40% by weight. In principle, the inorganic fibres may be freely selected among existing inorganic fibres, provided that they are cationic, i.e. have a positive charge. If the inorganic fibre is not cationic in itself, it can be made cationic by subjecting the fibre in per se known manner to a surface treatment such that the fibre will obtain a positive surface charge. It is preferred, in the present invention, that the inorganic fibres are mineral fibres, and most preferred are glass fibres. The fibre length and diameter are not critical, but it is preferred that the mean fibre diameter is within the range 1-20 µm, and that the mean fibre length is in the range 2-20 mm, preferably 5-15 mm.
- The sheet material according to the invention may comprise, as a further cationic constituent, a cationic polyelectrolyte in a content of up to about 2% by weight.
- A polyelectrolyte is a polymer having the character of an electrolyte, which means that, like an electrolyte, it is dissociated in aqueous solution in ions and is electrically conductive. Depending on whether the polymer main chain is positively or negatively charged upon dissociation, the polyelectrolyte is said to be cationic or anionic, respectively. The starting material of cationic polyelectrolytes are derivatives of esters and amides. A characteristic feature of these polyelectrolytes is an ammonium group which may be present in the form of a salt of tertiary amine, or as a quaternary ammonium group. The starting material for anionic polyelectrolytes usually is acrylic and methacrylic acid.
- The cationic polyelectrolyte, together with the remaining cationic constituents, i.e. the inorganic filler and the inorganic fibres, serves to balance the negative charges of the anionic constituents of the sheet material. In principle, such balancing of the positive and negative charges to obtain charge neutrality can be attained by suitable adjustment of the amounts of inorganic filler and inorganic fibres, and the cationic polyelectrolyte therefore is no indispensable constituent of the sheet material according to the invention. However, it has proved to be both simpler and more practicable, especially in the continuous production of the sheet material of the invention, to effect the said balancing and achieve charge neutrality by adding a cationic polyelectrolyte, and the invention therefore prefers to do so. As will be discussed in more detail hereinafter, the cationic polyelectrolyte is preferably added in repeated doses.
- The cationic polyelectrolyte can be selected among any available polyelectrolytes of this type, and since these are per se well known, no detailed enumeration would here seem necessary.
- As examples, however, mention may be made of the cationic polyelectrolytes commercially available from the company Stockhausen under the trade names Prestol 436k and Prestol 521k, and from the company Röhm GmbH, Federal Republic of Germany, under the trade name ROHAFLOC KL 925.
- In addition to the cationic constituents mentioned above, the sheet material also contains anionic constituents in an amount such that they form, together with the cationic constituents, a charge-neutral system. As has been mentioned before, the anionic constituents include a binder comprising an anionic polyelectrolyte and, optionally, also cellulose fibres. The use of anionic polyelectrolytes as dispersing and flocculating agents is previously known, but the inventor is not aware that they have been used before as a binder or, as in the present invention, added to an aqueous suspension or stock in order to develop dry strength in the sheet material formed. Generally, the anionic polyelectrolytes are in the form of diluted aqueous solutions having a concentration of about 10-35% by weight. Since anionic polyelectrolytes are per se well known, a detailed enumeration thereof would not seem necessary. As examples, however, mention may be made of the flocculating polymers commercially available under the trade name Prestol, for example Prestol 2935/74 which is manufactured by Stockhausen, and of the anionic polyelectrolyte Prodefloc N2M from the company Prodeco in Italy, and PLEX 4911 from the company Röhm GmbH. In the sheet material according to the invention, the content of anionic polyelectrolyte suitably is 3-20% by weight, preferably about 5-10% by weight.
- As mentioned above, the sheet material according to the invention may optionally contain cellulose fibres to improve the dry strength of the material. However, a high content of cellulose has a negative effect on the dimensional stability of the sheet material and its resistance to moisture and mildew, for which reason the cellulose fibre content of the invention is maintained as low as possible, such as at most about 8% by weight, preferably at most about 5% by weight. The cellulose fibres are preferably added in a content of about 2-5% by weight, more preferred about 4-5% by weight. For the production of sheets on a pick-up felt paper machine, the cellulose fibres can be left out completely. This is different from prior art technique which generally uses cellulose fibres in contents of 30% by weight and more. In contrast to prior art technique, the cellulose fibres of the present invention furthermore are not long, but have preferably been thoroughly beaten to a dewatering resistance of about 75-100° Schopper-Riegler (°SR).
- In addition to the above-mentioned cationic and anionic constituents, the sheet material of the invention also contains a strength-improving additive including thermoplastic polymer particles. By "particles" are here meant not only granules, but also flakes and fibres. The strength-improving additive is intended to impart dry strength to the sheet material in that the thermoplastic polymer particles during sheet production in, for example, the drying section or in a hot-calender are heated to cause them to sinter or fuse together at their contact or crossing points, while substantially maintaining their original configurations, such that the particles form a coherent three-dimensional network structure or reinforcement imparting dry strength to the sheet material.
- The thermoplastic polymer particles are preferably included in a content of about 2-20% by weight in the sheet material according to the invention.
- In principle, the charge of the thermoplastic polymer particles is not especially critical, and they may be for example anionic or nonionic, but it is especially preferred that they are nonionic. The thermoplastic polymer particles can be freely selected among available thermoplastic polymer particles or mixtures thereof. However, since the temperature in the drying section of the paper machine used for the production of the sheet material, and also in the hot-calender, lies at about 70-120°C, the thermoplastic polymer particles should be allowed to soften within this temperature range, preferably at about 70-80°C. An especially preferred thermoplastic polymer in the context of the invention is polyvinyl alcohol. Among other useful thermoplastic polymers, mention may be made of polyethylene, polypropylene, polyvinyl chloride, polyester and polycarbonate. As has been mentioned, the thermoplastic polymer particles may be in the form of fibres. The fibre dimensions are not critical, but it is preferred that they have a mean length of about 0.6-12 mm, preferably about 1-6 mm, and a weight length of about 0.5-10 dtex, preferably about 1-6 dtex.
- The sheet material according to the invention normally has a thickness of about 0.1-1.5 mm, preferably about 0.1-0.5 mm, and most preferred about 0.15-0.25 mm, but greater thicknesses can be obtained without difficulty by multi-layer techniques (using for example several head boxes).
- The production of the substantially inorganic fibrous sheet material according to the invention will now be described. As has been mentioned in the introduction, the sheet material is produced by paper technology, and since paper technology is a well-known and well-established technique, it would not seem necessary to give a detailed description of this technique and the equipment utilised. Instead, the description hereinafter is drawn to the characteristic features of the invention, i.e. the method by which the components are combined to form the sheet material, and the sequence in which this is done.
- In the method according to the invention, the inorganic fibres, preferably surface-treated glass fibres according to the above, are slushed in water. The glass fibre concentration preferably is about 1% by weight since the fibres in higher concentrations, for example above about 3% by weight, tend to form lumps.
- Then the inorganic filler which includes a mixture of talc and soapstone according to the above, is added to the glass fibres suspension, and preferably cellulose fibres are added as well to contribute to the strength of the material.
- Then the anionic polyelectrolyte is added to the resulting slurry or stock.
- After the anionic polyelectrolyte has been added, a charge-neutral system must be established, and if necessary the desired charge neutrality is adjusted by adding cationic material. As has been mentioned before, charge neutrality can be achieved in principle by relative adjustment of, on the one hand, the amounts of the anionic polyelectrolyte and any cellulose fibres present and, on the other hand, of the cationic inorganic filler and the cationic inorganic fibres. Such adjustment can be conveniently carried out during batchwise production of the sheet material according to the invention. In continuous sheet production utilising conventional paper technology, for example on a fourdrinier, or a Yankee machine, such controlled adjustment is not readily achieved, and it is therefore preferred to add cationic polyelectrolyte, whereby a charge-neutral system is quickly established.
- All of the requisite cationic polyelectrolyte can be added in one go, but it has surprisingly been found that it is to advantage if the cationic polyelectrolyte is added in several, preferably two doses. Thus, it was found that adding the cationic polyelectrolyte in one go gives an about 60-70% precipitation of the remaining anionically charged constituents of the sheet material, whereas a 95-100% precipitation is obtained if the cationic polyelectrolyte is added in two doses. The higher precipitation is readily observable visually in that the initially slightly milky suspension becomes limpid upon precipitation. When the cationic polyelectrolyte is added in batches, the first batch is preferably added to the stock after the anionic polyelectrolyte has been added, whereupon the second batch is added immediately ahead of the head box. The major part of the cationic polyelectrolyte, for example 60-95% by weight, preferably about 85-95% by weight, is added with the first batch. If use is made of nonionic thermoplastic polymer particles, such as the nonionic polyvinyl alcohol particles preferred according to the invention, the system must be charge-neutral if one is to obtain uniform distribution of the nonionic thermoplastic polymer particles.
- Besides the above-mentioned principal components of the sheet material according to the invention, one or more additives known in paper technology, such as hydrophobating agents, antifoaming agents, colourants, optical brightening agents, retention agents and lubricants, may be added as well.
- Care should be taken that the aqueous suspension or stock has a suitable ionic strength that can be controlled by means of alkali or alkaline earth salts, such as sodium, magnesium or calcium salts, of which calcium salts, such as calcium chloride, give the best result. The salt addition reduces the repulsion of the electric double layer between the less charged surfaces of the upper and lower sides of the filler particles. Normally, the calcium ion content is supplied by the water hardness which should be about 18-26° dH (German hardness), but if the water hardness is unsuitable, it is adjusted by adding a calcium salt so that the calcium content will be about 7-18 mol/m³ H₂O, which corresponds to about 0.4-1.0 kg CaCl₂/m³ H₂O.
- When all constituents have been supplied to the stock, the stock is run through the head box onto the wire and conducted through the press and drying sections of the paper machine in conventional manner. According to the invention, it is preferred that the first part of the drying section is heated to maximum temperature (about 90-120°C) to quickly achieve dry strength of the sheet material. To avoid fibre rising, the second part of the drying section should have a lower temperature (about 60-70°C). Furthermore, it is preferred to calender the sheet material after the drying section at a temperature of about 70-120°C and at a pressure of about 18-25 N/mm. As has been mentioned before, the strength-improving thermoplastic polymer of the sheet material should be selected such that it begins to soften on the surface at about 70°C, whereby the thermoplastic particles are bonded together at the crossing points during treatment in the drying section and the hot-calender. The thermoplastic particles should not, however, melt completely and flow into each other at the temperatures used in the drying section and the hot-calender, respectively.
- The sheet material according to the invention has a variety of applications, for example in wall, floor and roof covering materials (e.g. in roofing felt), and in foamed products, such as polyurethane, polyvinyl chloride and phenol plastics. The sheet material according to the invention may be included as a carrier or backing material, but may also be included as, for example, an intermediate layer, or be used separately.
- The sheet material according to the invention contains, as mentioned above, at least 50% by weight of inorganic material. Preferably, the sheet material contains 70-80% by weight or more of inorganic material, and so far as the inventor is aware it has not previously been possible, by using paper technology, to produce sheet materials with these high contents of inorganic fibres and fillers.
- To further illustrate the invention, the following nonrestrictive Examples are given.
- Three pieces of sheet material were produced, using the constituents and the contents (% by weight) indicated in Table 1.
- The soapstone used in the Examples was of type H340 from Handöl, Sweden. This is a micronised soapstone having a mean diameter of 5-10 µm. The talc content is about 67% by weight, and the loss on ignition about 8% by weight. The oil absorption value is 55 g oil/100 g soapstone, and the melting point is 1500°C.
- The talc used in the Examples was of the type Finntalk P40 from Outokumpu Oy, Finland, which has a mean diameter of about 10-20 µm, a talc content of about 97% by weight, a loss on ignition of 7% by weight, and an oil absorption value of 32 g oil/100 g talc. The melting point is 1375°C.
- The thermoplastic particles used in the Examples were polyvinyl alcohol flakes of the type Moviol from Hoechst and polypropylene fibres of the type Pulpex P from Herkules.
TABLE 1 Examples 1 2 3 Glass fibres (cationic, length 10 mm, diameter 3 µm) 20 35 29 Soapstone 40 33 25 Talc 28 13 25 Cellulose (long-fibre pine sulphate cellulose which has been beaten and bleached, 95°SR) 4 6 - Cationic polyelectrolyte (ROHAFLOC KL 925 from Röhm) 0.5 1.0 - Anionic polyelectrolyte (PLEX 4911 from Röhm) 5 7 10 Thermoplastic particles (PVA) 2.5 5 11 - First about 1.0 kg CaCl₂/m³ H₂O is added to the stock water to give a water hardness of 23° dH. Then the cationic glass fibre is added and slushed to a slurry having a concentration of about 1.0% by weight. To the slurry, the cationic soapstone and the talc are admixed. The soapstone is greyish-green, and the talc practically white. In those cases where the composition includes cellulose fibres, these are also supplied to the slurry.
- Then the anionic polyelectrolyte is added, and the system now begins to turn into a charge-neutral system. To ensure that the system is indeed a charge-neutral system, the cationic polyelectrolyte is added in several (two) doses. Finally, the thermoplastic particles are added to the charge-neutral system.
- The resulting slurry or stock is supplied to the paper machine, and the water is sucked off immediately ahead of the drying section. The first part of the drying section has been heated to maximum temperature (about 90-120°C) to rapidly increase the dry strength of the sheet. After the drying section, the sheet is hot-calendered at a pressure of 23 N/mm.
- The properties of the sheet materials thus produced were then tested, and the results obtained are indicated in Table 2.
TABLE 2 Examples 1 2 3 Grammage, g/m² 130 135 132 Thickness, mm 0.163 0.151 0.175 Density, g/dm³ 798 894 754 Air resistance No. (Gurley), s 5 4 2 Tensile index, machine direction 15.2 18.3 33.9 Tensile index, cross direction 7.9 8.9 16.2 Elongation, machine direction, % 2.1 1.6 4.2 Elongation, cross direction, % 1.5 1.7 4.6 Bending force, mN 59 53 91 Dimensional stability, machine direction % * 0.13 0.14 0.12 Dimensional stability, cross direction % * 0.16 0.16 0.14 Z-strength, kPa 183 158 222 Coal ash % 88 81 79 * The values of dimensional stability are the difference in per cent in the machine and cross directions, respectively, of the dimensions of the material before and after soaking in water for 10 min.
and forming a sheet from the stock.
Claims (20)
1-80% by weight of inorganic filler,
1-80% by weight of inorganic fibres,
3-20% by weight of anionic polyelectrolyte,
2-20% by weight of thermoplastic polymer particles.
(a) cationic inorganic fibres;
(b) a cationic inorganic filler including a mixture of talc and soapstone;
(c) an anionic binder including an anionic polyelectrolyte, and
(d) strength-improving additives including thermoplastic polymer particles,
the charge of the stock being controlled such that a substantially charge-neutral system is obtained
and forming a sheet from the stock.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT89850055T ATE95860T1 (en) | 1988-02-26 | 1989-02-20 | PRINCIPALLY INORGANIC FIBROUS MATERIALS AND THEIR PRODUCTION PROCESSES. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE8800661 | 1988-02-26 | ||
SE8800661A SE466110B (en) | 1988-02-26 | 1988-02-26 | FIBER CONTAINER, ESSENTIAL INORGANIC SHEET MATERIAL, MADE TO MANUFACTURE ANY SUCH AND FILLER FOR USE THEREOF |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0330635A1 true EP0330635A1 (en) | 1989-08-30 |
EP0330635B1 EP0330635B1 (en) | 1993-10-13 |
Family
ID=20371494
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP89850055A Expired - Lifetime EP0330635B1 (en) | 1988-02-26 | 1989-02-20 | Substantially inorganic fibrous material and method for the production thereof |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP0330635B1 (en) |
AT (1) | ATE95860T1 (en) |
DE (1) | DE68909810T2 (en) |
FI (1) | FI890861A (en) |
SE (1) | SE466110B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1995027825A1 (en) * | 1994-04-12 | 1995-10-19 | Korea Research Institute Of Chemical Technology | Preparation process of paper for increasing filler contents and enhancing scott internal bond strength |
EP1816258A1 (en) * | 2004-11-24 | 2007-08-08 | Nippon Sheet Glass Company, Limited | Inorganic fiber paper |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102009036551A1 (en) * | 2009-08-10 | 2011-02-17 | J. Rettenmaier & Söhne Gmbh + Co. Kg | Pulp-containing cellulose-based material |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0003214A1 (en) * | 1978-01-24 | 1979-08-08 | Gaf Corporation | A method of manufacturing glass fibre mats from an aqueous dispersion of glass fibres and a method of forming said dispersion |
GB2031475A (en) * | 1978-09-08 | 1980-04-23 | Dalle & Lecomte Papeteries | Paper product having a high filler content |
GB1597369A (en) * | 1976-12-03 | 1981-09-09 | Holbek Kjeld Aps | Composite material |
-
1988
- 1988-02-26 SE SE8800661A patent/SE466110B/en not_active IP Right Cessation
-
1989
- 1989-02-20 DE DE68909810T patent/DE68909810T2/en not_active Expired - Fee Related
- 1989-02-20 EP EP89850055A patent/EP0330635B1/en not_active Expired - Lifetime
- 1989-02-20 AT AT89850055T patent/ATE95860T1/en not_active IP Right Cessation
- 1989-02-23 FI FI890861A patent/FI890861A/en not_active IP Right Cessation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1597369A (en) * | 1976-12-03 | 1981-09-09 | Holbek Kjeld Aps | Composite material |
EP0003214A1 (en) * | 1978-01-24 | 1979-08-08 | Gaf Corporation | A method of manufacturing glass fibre mats from an aqueous dispersion of glass fibres and a method of forming said dispersion |
GB2031475A (en) * | 1978-09-08 | 1980-04-23 | Dalle & Lecomte Papeteries | Paper product having a high filler content |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1995027825A1 (en) * | 1994-04-12 | 1995-10-19 | Korea Research Institute Of Chemical Technology | Preparation process of paper for increasing filler contents and enhancing scott internal bond strength |
AU687132B2 (en) * | 1994-04-12 | 1998-02-19 | Korea Research Institute Of Chemical Technology | Preparation process of paper for increasing filler contents and enhancing scott internal bond strength |
EP1816258A1 (en) * | 2004-11-24 | 2007-08-08 | Nippon Sheet Glass Company, Limited | Inorganic fiber paper |
EP1816258A4 (en) * | 2004-11-24 | 2010-04-21 | Nippon Sheet Glass Co Ltd | Inorganic fiber paper |
Also Published As
Publication number | Publication date |
---|---|
DE68909810T2 (en) | 1994-05-19 |
SE466110B (en) | 1991-12-16 |
FI890861A (en) | 1989-08-27 |
SE8800661L (en) | 1989-08-27 |
DE68909810D1 (en) | 1993-11-18 |
ATE95860T1 (en) | 1993-10-15 |
FI890861A0 (en) | 1989-02-23 |
EP0330635B1 (en) | 1993-10-13 |
SE8800661D0 (en) | 1988-02-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR101861529B1 (en) | Cellulose-reinforced high mineral content products and methods of making the same | |
CA1055292A (en) | Manufacture of paper | |
US5139615A (en) | Composite sheet made from mechanically delaminated vermiculite | |
DE60311378T2 (en) | Surface-treated heat-bondable fiber-containing paper products, and process for their preparation | |
US5294299A (en) | Paper, cardboard or paperboard-like material and a process for its production | |
DE2516097A1 (en) | PAPER FILLER | |
WO2004015200A1 (en) | Method for the production of paper, paperboard, and cardboard | |
JPS6323318B2 (en) | ||
MXPA02005271A (en) | Soft tissue products containing particulate fillers. | |
CA1113661A (en) | Composite material | |
US4352719A (en) | Method for producing combustion resistant fibrous products | |
EP0330635B1 (en) | Substantially inorganic fibrous material and method for the production thereof | |
US4680223A (en) | Fibrous inner web for sheet vinyl flooring goods | |
CA2194680C (en) | A process for the production of paper | |
EP0331656B1 (en) | Coating method and coating slip for fibrous sheet material | |
EP0406354B2 (en) | Process of manufacture of composite fiberboard | |
CA1203056A (en) | Fibre product-manufacture | |
US4609433A (en) | Sheet composites containing crystalline phosphate fibers | |
FI80742B (en) | Method for the manufacture of paper containing clay or other filler | |
CA2001784A1 (en) | Paper, cardboard or paperboard-like material and a process for its production | |
CA1147541A (en) | Glass fiber mat | |
JP4214495B2 (en) | Separator paper for air conditioning filter | |
US4806205A (en) | Process for preparing sheet composites containing crystalline phosphate fibers | |
CA1228703A (en) | Use of serpentinite as an additive | |
KR101904437B1 (en) | Manufacturing method of corrugated fiberboard |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH DE ES FR GB GR IT LI LU NL SE |
|
17P | Request for examination filed |
Effective date: 19890826 |
|
17Q | First examination report despatched |
Effective date: 19910704 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE CH DE ES FR GB GR IT LI LU NL SE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED. Effective date: 19931013 Ref country code: NL Effective date: 19931013 Ref country code: LI Effective date: 19931013 Ref country code: AT Effective date: 19931013 Ref country code: CH Effective date: 19931013 Ref country code: ES Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY Effective date: 19931013 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 19931013 Ref country code: BE Effective date: 19931013 |
|
REF | Corresponds to: |
Ref document number: 95860 Country of ref document: AT Date of ref document: 19931015 Kind code of ref document: T |
|
REF | Corresponds to: |
Ref document number: 68909810 Country of ref document: DE Date of ref document: 19931118 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 19940114 Year of fee payment: 6 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 19940216 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 19940218 Year of fee payment: 6 |
|
ET | Fr: translation filed | ||
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19940228 |
|
NLV1 | Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act | ||
RAP2 | Party data changed (patent owner data changed or rights of a patent transferred) |
Owner name: MINOVERT AB |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 19940331 Year of fee payment: 6 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
EAL | Se: european patent in force in sweden |
Ref document number: 89850055.8 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19950220 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Effective date: 19950221 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19950220 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Effective date: 19951031 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19951101 |
|
EUG | Se: european patent has lapsed |
Ref document number: 89850055.8 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |