Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
  • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
  • H01B3/48—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances fibrous materials
  • H01B3/52—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances fibrous materials wood; paper; press board
• • 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
  • D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
  • D21H11/02—Chemical or chemomechanical or chemothermomechanical pulp
  • D21H11/04—Kraft or sulfate pulp
• • 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
• • 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
  • D21H13/44—Flakes, e.g. mica, vermiculite
• • 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
  • D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/54—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen
  • D21H17/55—Polyamides; Polyaminoamides; Polyester-amides
• • 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
• • 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
• • 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
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
  • D21H21/18—Reinforcing agents
  • D21H21/20—Wet strength agents

Definitions

• the invention relates to a simple and inexpensive producible Elektroisolierpapier with improved electrical strength or dielectric strength and improved dielectric properties or impedance or permittivity, a method for its production and cables, transformers, capacitors or electrical equipment, with this Insulating material are equipped.
• Mica or talc in comparison to unfilled papers of the same type, have an increased dielectric strength at low electrical loss factor (tan ⁇ ).
• Insulation material established for high voltage applications.
• the basis weights of such papers are usually in the range of 70-120 g / m 2 and the density at 0.6 to 1.2 g / m 2 , the high densities being based on a compaction between pressure-loaded rollers (calenders).
• paper still plays a major role in the field of electrical insulation.
• the applications cover all types of transformers, cables and capacitors, in particular oil-filled transformers, cables and capacitors. With the rapid increase in power consumption in recent years, there is a demand for higher power transmission capacity through higher ones
• the dielectric loss factor tan ⁇ is an important factor for evaluating an insulating medium.
• the magnitude of the loss factor depends on the temperature, electrical frequency and voltage and is important for the use of a
• the dielectric loss factor tan ⁇ is defined as the ratio of active power to reactive power and is therefore a measure of how much energy an insulating material absorbs in the alternating electric field and converts it into heat loss. It is therefore desirable to keep the tan ⁇ as small as possible.
• the material sought for processing reasons a certain minimum strength and for impregnation with an electrically insulating impregnating agent, such as oil, the highest possible permeability for rapid penetration of the insulation
• the papers used for cable insulation must also allow due to their mechanical properties preferably the wrapping of the conductor in a technologically meaningful way. According to the prior art, such papers based on pulp are always unfilled and, if possible, made of pure kraft pulp. To extend the life of the paper while basic compounds for binding emerging acid can be incorporated as a buffer. Furthermore, resins or synthetic fibers to increase the mechanical strengths may be included.
• this object is achieved by the use of 15 to 95 wt.% Of synthetic resin fibers in the presence of polymer fibrils, synthetic resin powder and
• the object of the present invention is to at least partially overcome the drawbacks known in the prior art and in particular to provide a paper which, when manufactured inexpensively, has both a high and low cost
• This object of the invention is achieved by an electrical insulation paper according to claim 1.
• Preferred embodiments of the electrical insulation paper are the subject of the dependent claims.
• the object is also achieved by a method for producing the electrical insulation paper and its use.
• the electrical insulating paper according to the invention has an electrical
• Dielectric strength of greater than 40 kV / mm preferably greater than 60 kV / mm and in particular greater than 80 kV / mm, this being achieved in that the paper according to the invention contains 20 to 99% by weight of cellulose and 1 to 80% by weight.
• the mineral filler comprises at least one layered silicate, which preferably contains talc and / or mica.
• the proportion of cellulose according to a particularly preferred embodiment is in a range between 30 to 80 wt .-%, preferably 45 to 70 wt .-% and in particular about 65 wt .-%.
• the proportion of mineral fillers is moreover preferably in a range between 3 to 65 wt .-%, preferably 5 to 45 wt .-% and in particular about 30 wt .-%.
• Talcum is a hydrophobic mineral that has many applications due to its chemical and thermal stability and its lamellar morphology. Talc can be used as a kind of inorganic polymer
• Talcum can have different amounts of associated minerals include, among which chlorites (hydrous aluminum and magnesium silicates), magnesite (magnesium carbonate), calcite (calcium carbonate) and dolomite (calcium and magnesium carbonate) prevail. Due to its low dissipation factor, the good dielectric properties, the high thermal conductivity and low electrical conductivity, as well as the comparatively high oil absorption and at the same time a low tendency to absorb water combined with relative chemical inertness, talcum is particularly suitable as a filler according to the invention. Besides talc, the mineral filler may also contain mica as a constituent, the proportion of which is preferably between 1% and 80%, in particular between 10 and 50%, and particularly preferably greater than 20%. It is also within the meaning of the present invention to use as mineral filler exclusively mica. Mica is a clear transparent material (aluminosilicate) with a high electrical resistance. It is resistant to a constant
• mica is resistant to almost all media, e.g. Alkalis, chemicals, gases, oils and acids.
• Mica are a mineral group monoclinic or
• pseudohexagonal, complex silicates which are characterized by a perfect basal cleavage. They are very easy to split into thin, flexible and elastic leaflets. Under mica according to the present
• Muscovite mica and phlogopite mica Muscovite mica and phlogopite mica.
• the mineral filler in particular also the phyllosilicates to be used, preferably have an average particle size distribution of 0.5 to 400 ⁇ m and in particular from 1 to 200 ⁇ m and / or flakes with an average thickness of 0.01 to 100 ⁇ m and in particular from 0.1 to 50 ⁇ .
• native or modified starch in proportions of from 0.1 to 10% by weight, in particular from 2 to 8% by weight, and more preferably about 4 wt.%, or other polyols, such as native or modified guar.
• polyols can also be used in combination with each other.
• the proportion of modified or unmodified guar according to a preferred embodiment between 0.1 to 5 wt.%, In particular 2 to 4 wt.% And in particular about 2.5 wt.% Are.
• organic binders may be used in combination or alone, the proportion of which may be between 0.1 to 20% by weight, in particular 3 to 12% by weight and preferably about 5 to 8% by weight.
• a further additive may further in combination or alone the inventive electrical insulating paper in a further preferred
• % By weight, in particular from 0.1 to 3% by weight, and preferably about 0.5% by weight, is within the meaning of the present invention.
• the electrical insulating paper according to the invention nitrogen-containing basic
• Another improvement can be the addition of polymers with binder or
• Cobinder capabilities offer, such as the addition of 0.1 to 10 wt.%, In particular 1 to 6 wt.% Of polyvinyl alcohol (PVA).
• PVA polyvinyl alcohol
• the dielectric strength is measured according to DIN 53481 of
• Hot water extract measured according to TAPPI Standard T 252 is less than 5 mS / m, preferably less than 3 mS / m and in particular less than 1 mS / m. Also the conductivity 53481 of the electrical insulating paper according to the invention in
• Hot-water extract according to TAPPI Standard T 252 is preferably less than 5 mS / m, in particular 3 mS / m and in particular less than 1 mS / m.
• Polysaccharides are used. Due to the higher comparable mechanical strength and electrical breakdown strength, kraft pulps are preferred here. The degree of fibrillation is hereby for the sake of
• Isolation effect on the one hand be as high as possible, that is, the pulp is highly milled before with a Schopper Riegler value of preferably 40 to 80 ° SR.
• a highly ground pulp forms a denser paper with a lower penetration rate of the oil required for isolation, so that the rate of penetration of the oil into the paper becomes too slow for the purposes of economically meaningful production.
• the expert will adjust the grinding of the pulp from the above point of view and settle as possible in a range of 20 to 60 ° SR, preferably at 25 to 40 ° SR.
• the pulps used can also be mixed with other plastic fibers in order either to increase the mechanical strength of the end product or to produce the end product for marketing or other reasons
• Phyllosilicates such as mica or talc with the highest possible
• Layer silicates in particular two- or three-layer silicates, are in particular mineral substances such as mica, talc, serpentine and clay minerals such as vermiculite, muscovite (a three-layer silicate) (KAI 2 [(OH) 2
• Two-layer silicate Al [(OH) 8
• phlogopite or artificial phyllosilicates such as Na 2 Si 2 O 5 .
• the added starch can be used in the chemically unmodified form as gelatinized or unverkleisterte starch. But chemically modified starches, hydrolytic or oxidative or enzymatic or degraded by physical agents starches can be used here.
• the starches may also be in modified form, hydrophobically or ionically modified. Low degrees of substitution are preferred in the case of ionically modified starches, since otherwise the dielectric loss factor may deteriorate.
• hemicelluloses or polyols such as native or modified guar, may be added to the strength enhancer or, if desired, completely replace it. These may also be hydrophobic or ionically modified, and here again analogously to starch, a low average degree of substitution is preferred.
• polymers having binder or cobinder capabilities can be added to the known in papermaking or paper finishing organic polymeric binder systems or latexes here the addition of 0.1 to 5 wt.% (Based on the finished dried final product) of polyvinyl alcohol (PVA) is preferred.
• PVA polyvinyl alcohol
• the polyvinyl alcohols can in this case both fully hydrolyzed as well
• Chain lengths are present as homopolymers or copolymers.
• the dissolution behavior of polyvinyl alcohols is known to be highly dependent on both its structure and the degree of branching, the molecular weight, as well as the degree of hydrolysis. Of particular importance here are the dissolution temperature, the stirring speed and the stirring time and the geometric design of the mixing vessel, stirrer and possibly existing Flow resistances. The person skilled in the art will adapt his procedure to the respective product.
• a sizing agent may be added to the paper during production or else optionally in a separate step.
• Particularly suitable for this purpose are the already known products such as alkyl ketene dimers (AKD) with different chain lengths. But alkenylsuccinic anhydrides (ASA) and also, for example, paraffins can be used for this purpose.
• Strength increases in electrical insulating paper can also by the addition of wet strength agents such as melamine or urea-formaldehyde resins, amidoamine or polyamine-epichlorohydrin resins or wet strength agents based on hemiacetal and acetal bonds, such as glyoxal be achieved.
• wet strength agents such as melamine or urea-formaldehyde resins, amidoamine or polyamine-epichlorohydrin resins or wet strength agents based on hemiacetal and acetal bonds, such as glyoxal be achieved.
• nitrogen-containing compounds such as dicyandiamides, melamine-containing compounds, urea-containing compounds or amino-containing polymers or
• Insulation papers a significantly higher porosity and a significantly increased Penetration speed compared to oleophilic liquids.
• Insulating paper is classified into a wide variety of types and grades, including coil insulating paper, condenser tissue paper, high voltage capacitor paper, cable insulating paper, high voltage cable insulating paper, and the like. Papers of all these types can be treated according to the invention to increase the dielectric strength and to reduce the loss factor and the aging processes.
• the electrical insulating papers according to the invention are produced according to the methods customary in the paper industry.
• the fibrous or powdery starting materials are slurried in water and produce a suspension having a solids content of preferably 0.1 to 10 wt .-%. This process takes place in conventional papermaking processes in the range of pH 4 to 10, preferably pH 7 to 9.
• the resulting suspension is prepared on conventional paper machines, e.g. Four-wire or rotary screening machines or gap former machines are applied, where they are distributed over a large area and the majority of the water is dewatered and removed by pressing and drying. The fibrils hold the paper fibers together, so that the resulting base paper receives sufficient initial wet strength.
• conventional paper machines e.g. Four-wire or rotary screening machines or gap former machines are applied, where they are distributed over a large area and the majority of the water is dewatered and removed by pressing and drying. The fibrils hold the paper fibers together, so that the resulting base paper receives sufficient initial wet strength.
• the strength of the paper can be increased even more by strength-increasing additives such as native or modified starch, natural or organic binders and polyvinyl alcohols.
• This base paper is then dried at temperatures between 100 and 180 ° C, preferably between 80 and 180 ° C, by e.g. over heated cylinders leads. Then it is at elevated
• Temperature optionally smoothed under pressure and compacted This can be done on conventional smoothing rollers and / or rolling mills, wherein a relatively high pressure is exerted on the paper.
• the temperatures in this smoothing or pressing are according to the invention in a range of greater than 80 ° C or 100 ° C, preferably greater than 160 ° C or 180 ° C.
• the paper may also be further solidified by subsequent impregnation with resins, e.g. with epoxy, formaldehyde, polyester, silicone, phenolic or acrylate resins or with polyimides or
• the paper according to the invention can be made after the production by means of a compression and
• the invention also encompasses the use of the electrical insulating paper according to the invention for the electrical insulation of components or electric current-carrying products such as
• Table 1 shows the influence of different pulp fibers and compositions on the dielectric strength and mechanical strengths;
• Table 2 shows a comparison between papers of the prior art with
• the tensile strength or resistance to breakage was determined according to EN ISO 1924-2.
• the determination of the conductivity was based on a hot water extract according to the TAPPI Standard T 252.
• the parts and percentages given in the examples are by weight.
• the pulp used was ground to a Schopper-Riegler value of 32 to 34 "SR prior to use.
• Examples 1 to 32 in Table 1 relate to the evaluation of various papers to blank samples, which from the specified pulp with / without addition of
• Alkylketene dimer in the form of a commercial dispersion for use.
• a polyamidoamine-epichlorohydrin resin was used.
• Examples 33 to 35 in Table 1 show measurement results of commercially available electrical insulating papers.
• OS means the top of the paper and SS the side facing the wire in papermaking.
• transverse measurement means transverse to the direction of the paper machine and along the paper machine direction.
• the reference papers produced on a Rapid-Köthen lab-sheet former omit this indication, since there is no preferred direction of movement and fiber orientation.
• the pulp may also be fibrillated with any other suitable equipment, such as a Dutchman or a refiner.
• any other suitable equipment such as a Dutchman or a refiner.
• the pulp can subsequently be further freed of impurities and charge carriers by means of a centrifuge, for example.
• Comparative prior art paper from kraft pulp (# 36) is shown.
• the comparative paper is made with papers of the invention made with modified fabric formulations, i. compared with / without the addition of fillers (talcum and / or mica) and with or without the addition of additives. These papers were all carefully dried and conditioned in a desiccator over a desiccant at a constant temperature of 25 ° C.
• FIG. 1 shows the oil transfer history for different papers in

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• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Dispersion Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Paper (AREA)
• Organic Insulating Materials (AREA)
• Insulating Bodies (AREA)

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• 2012
  • 2012-04-27 DE DE102012103775A patent/DE102012103775A1/de not_active Withdrawn
• 2013
  • 2013-04-29 WO PCT/EP2013/058910 patent/WO2013160484A1/de not_active Ceased
  • 2013-04-29 US US14/396,834 patent/US20150083353A1/en not_active Abandoned
  • 2013-04-29 IN IN9318DEN2014 patent/IN2014DN09318A/en unknown
  • 2013-04-29 BR BR112014026694A patent/BR112014026694A2/pt not_active IP Right Cessation
  • 2013-04-29 RU RU2014144899A patent/RU2014144899A/ru unknown
  • 2013-04-29 CN CN201380027330.3A patent/CN104334797A/zh active Pending
  • 2013-04-29 EP EP13724178.2A patent/EP2841650B1/de active Active
  • 2013-04-29 CA CA2871206A patent/CA2871206A1/en not_active Abandoned

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