GB2100188A - Laminated insulating paper and its use - Google Patents
Laminated insulating paper and its use Download PDFInfo
- Publication number
- GB2100188A GB2100188A GB8211545A GB8211545A GB2100188A GB 2100188 A GB2100188 A GB 2100188A GB 8211545 A GB8211545 A GB 8211545A GB 8211545 A GB8211545 A GB 8211545A GB 2100188 A GB2100188 A GB 2100188A
- Authority
- GB
- United Kingdom
- Prior art keywords
- paper
- laminated insulating
- oil
- insulating paper
- film
- 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
- 229920000098 polyolefin Polymers 0.000 claims description 30
- -1 polyethylene Polymers 0.000 claims description 7
- 239000004698 Polyethylene Substances 0.000 claims description 6
- 238000002844 melting Methods 0.000 claims description 6
- 230000008018 melting Effects 0.000 claims description 6
- 229920000573 polyethylene Polymers 0.000 claims description 6
- 229920003043 Cellulose fiber Polymers 0.000 claims description 5
- 239000004020 conductor Substances 0.000 claims description 5
- 150000004996 alkyl benzenes Chemical class 0.000 claims description 3
- 239000007788 liquid Substances 0.000 claims 2
- 239000000463 material Substances 0.000 claims 1
- 229920005672 polyolefin resin Polymers 0.000 abstract 1
- 239000000123 paper Substances 0.000 description 61
- 239000003054 catalyst Substances 0.000 description 8
- 238000004132 cross linking Methods 0.000 description 8
- 238000009833 condensation Methods 0.000 description 6
- 230000005494 condensation Effects 0.000 description 6
- 239000008188 pellet Substances 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- KWKXNDCHNDYVRT-UHFFFAOYSA-N dodecylbenzene Chemical compound CCCCCCCCCCCCC1=CC=CC=C1 KWKXNDCHNDYVRT-UHFFFAOYSA-N 0.000 description 5
- SCPYDCQAZCOKTP-UHFFFAOYSA-N silanol Chemical compound [SiH3]O SCPYDCQAZCOKTP-UHFFFAOYSA-N 0.000 description 5
- 230000015556 catabolic process Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 229920001903 high density polyethylene Polymers 0.000 description 4
- 239000004700 high-density polyethylene Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- XMNIXWIUMCBBBL-UHFFFAOYSA-N 2-(2-phenylpropan-2-ylperoxy)propan-2-ylbenzene Chemical compound C=1C=CC=CC=1C(C)(C)OOC(C)(C)C1=CC=CC=C1 XMNIXWIUMCBBBL-UHFFFAOYSA-N 0.000 description 3
- 239000004594 Masterbatch (MB) Substances 0.000 description 3
- UKLDJPRMSDWDSL-UHFFFAOYSA-L [dibutyl(dodecanoyloxy)stannyl] dodecanoate Chemical compound CCCCCCCCCCCC(=O)O[Sn](CCCC)(CCCC)OC(=O)CCCCCCCCCCC UKLDJPRMSDWDSL-UHFFFAOYSA-L 0.000 description 3
- 239000012975 dibutyltin dilaurate Substances 0.000 description 3
- NKSJNEHGWDZZQF-UHFFFAOYSA-N ethenyl(trimethoxy)silane Chemical compound CO[Si](OC)(OC)C=C NKSJNEHGWDZZQF-UHFFFAOYSA-N 0.000 description 3
- 229940063583 high-density polyethylene Drugs 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000002195 soluble material Substances 0.000 description 3
- 230000008961 swelling Effects 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000037303 wrinkles Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004709 Chlorinated polyethylene Substances 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229920005601 base polymer Polymers 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000005038 ethylene vinyl acetate Substances 0.000 description 1
- 229920006244 ethylene-ethyl acrylate Polymers 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 229920006262 high density polyethylene film Polymers 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000002655 kraft paper Substances 0.000 description 1
- 229920001684 low density polyethylene Polymers 0.000 description 1
- 239000004702 low-density polyethylene Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 125000003808 silyl group Chemical group [H][Si]([H])([H])[*] 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B27/10—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of paper or cardboard
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
-
- 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
- D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
- D21H27/30—Multi-ply
- D21H27/32—Multi-ply with materials applied between the sheets
- D21H27/34—Continuous materials, e.g. filaments, sheets, nets
- D21H27/36—Films made from synthetic macromolecular compounds
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2305/00—Condition, form or state of the layers or laminate
- B32B2305/72—Cured, e.g. vulcanised, cross-linked
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2457/00—Electrical equipment
- B32B2457/04—Insulators
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Organic Insulating Materials (AREA)
- Insulating Bodies (AREA)
- Laminated Bodies (AREA)
Abstract
This invention relates to laminated insulating paper found to be excellent in electrical properties, oil resistance and peel resistance prepared by sticking fibrous paper on at least one surface of a film of cross- linked silyl-modified polyolefin resin having 20-70% gel content. This invention also relates to oil-paper insulated electrical devices utilizing said laminated insulating paper. <IMAGE>
Description
SPECIFICATION
Laminated insulating paper and its use
The present invention relates to a laminated insulating paper and oil-paper insulated electrical devices in which the laminated insulating paper is utilised, and particularly to a laminated insulating paper having excellent electrical characteristics, oil resistance and peel resistance as well as oil-paper insulated electrical devices utilising such laminated insulating paper.
With the recent increase in demand for electric power, an OF cable of the 500 Kv class has been developed. In such an extra-high voltage OF cable, the use of a conventional insulating paper consisting of cellulose papers alone results in marked dielectric loss, and there is a problem where such an OF cable is utilised as a long distance power transmission cable. For this reason, the use of such laminated insulating paper in which cellulose fibre papers are welded to both sides of a high-density polyethylene film has been studied.
However, when such laminated insulating paper is used in an insulating oil at a high temperature (for instance, in alkylbenzene at 1 000C), 2.58.0% of its base resin in the film layer dissolves in the insulating oil. Further, the film layer swells by 59% in the direction of the thickness, so that there is a danger of increasing its oil flow resistance or lowering the peel strength with respect to the cellulose fibre paper, resulting in wrinkles and buckling.
In this respect, the present inventors have previously developed a laminated insulating paper which is prepared by welding a cellulose fibre paper or papers to at least one side of a silyl-modified polyolefin film, and then crosslinking the film thus welded; a patent application therefor is now on file (UK Patent Application GB 2,002,684A).
The laminated insulating paper according to the previous invention has characteristic features in that the peel strength thereof is very remarkable due to the effects of the silyl group in the silyl-modified polyolefin, and the oil resistance thereof is also favourable, because the silyl-modified polyolefin has been cross-linked.
However, since such a silyl-modified polyolefin after cross-linking has usually 70% or less gel content (treated with xylene at 1 300C x 24 hours; which conditions also apply to gel content as quoted hereinafter), there is a considerable amount of soluble part. In such circumstances, there are disadvantages in that the soluble part dissolves in an insulating oil, resulting in rise of viscosity of the insulating oil to increase the oil flow resistance thereof, and the crosslinked silyl-modified polyolefin film portion of the laminated insulating paper swells in the insulating oil, resulting in a lowering of flexibility of an OF cable in the case where, for example, such laminated insulating paper is utilised in the OF cable.
As a result of the present inventors' study for overcoming such disadvantages in conventional laminated insulating films, it has been found that when a crosslinked silyl-modified polyolefin film is stretched under certain conditions, the amount of soluble matter, as well as the degree of swelling with respect to an insulating oil, can be decreased markedly. Further, shrinkage of the film at the time of heating the same, which is generally observed when stretching a crosslinked plastic film, can also be reduced markedly.
Accordingly, the present invention seeks to provide a laminated insulating paper composed of a fibrous paper or papers and at least one sheet of a crosslinked silyl-modified polyolefin film having a gel content of 2070% and a thickness of 0.07-0.8 mm, the polyolefin film being stretched at a temperature of 800C or more and lower than the melting point of the polyolefin film at a draw ratio of a value equal to or more than that at the yield point thereof, and the thus stretched polyolefin film being laminated onto at least one side of the fibrous paper or papers. The melting point of the polyolefin is given herein as the temperature of the principal peak measured by differential scanning calorimeter (D.S.C.).
The present invention also seeks to provide oil-paper insulated electrical devices in which the resulting laminated insulating paper is utilised.
The present invention will now be further explained by way of example in the following description of embodiments thereof when taken together with the accompanying drawings, wherein:
Figure 1 is a cross sectional view showing an OF cable utilised in an embodiment of an oil-paper insulated electrical device according to the present invention;
Figure 2 is a graphical representation illustrating a relationship between a draw ratio and a rate of change of dimensions in oil as well as that between the draw ratio and oil absorption in respect of a crosslinked silyl-modified polyethylene film used in the laminated insulating paper according to the present invention; and
Figure 3 is a side view showing a sample for measuring oil flow resistance of the OF cable according to the present invention.
The silyl-modified polyolefin utilised in the present invention may be obtained as follows. A device having heating and kneading functions, such as an extruder, is charged with a mixture prepared by adding 0.5-10 parts per 100 parts of resin (PHR) of trialkoxysilane such as vinyltrimethoxysilane (VTMOS) and 0.01--2.0 PHR of a radical generating agent such as dicumyl peroxide (DCP) to a polyolefin, and the mixture is heated and kneaded at a temperature of about 200 C in the device.
As a base polymer for the silyl-modified polyolefin, high or low-density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-propylene copolymer, chlorinated polyethylene or the like may be employed, and particularly preferable is highdensity polyethylene.
The cross-linked silyl-modified polyolefin film used in the present invention is obtained in such manner that a film with a thickness of 0.07-8.00 mm is prepared from the aforesaid silyl-modified polyolefin in accordance with the T-die method or inflation method, and then the resulting film is subjected to crosslinking by reacting with water in the presence of a silanol condensation catalyst, such as dibutyltin dilaurate (DBTDL).
The silanol condensation catalyst may be applied to the film in either a manner in which the catalyst is admixed with silyl-modified polyolefin pellets at the time of extrusion molding of the film in accordance with a masterbatching procedure and then the admixture supplied to an extruder, or a manner in which a film is formed from the silyl-modified polyolefin, and the condensation catalyst is then contacted with the surface of the resulting film to permit the catalyst to penetrate into the film.
The film is crosslinked by passing it through a hot water or water vapour atmosphere with a high temperature. Such crosslinking proceeds also in the case where the film is allowed to merely stand in a room, although a considerable period of time is required. The degree of crosslinking of the film is adjusted to give a range of gel content of 2070%, preferably 4565%.
Cases where the crosslinking of the film is less than 20% or where the crosslinking is more than 70% are not preferable, because the oil resistance becomes insufficient in the former case, while the workability becomes inferior in the latter case.
According to the present invention, the crosslinked silyl-modified polyolefin film thus obtained is stretched with a draw ratio equal to or more than that at the yield point thereof at a temperature of 800C or more and lowerthan the melting point of the film.
If the temperature at the time of stretching the film is less than 800 C, the stretching thereof is difficult, while, on the contrary, if the temperature exceeds the melting point of the film, the effects of the stretching are reduced, so that such conditions are not preferable. The draw ratio is generally adjusted to 2.8 times or more, and preferably 3 times or more.
Stretching of the film may be carried dut by drawing the film off, for example, a pair of parallel capstan rollers, the follow-up of which is adjusted to be driven at a faster rate than that of the preceding roll.
The film thus obtained has a very low solubility as well as degree of swelling with respect to a synthetic insulating oil as indicated in the following examples. Further, shrinkage of the film in an oil at a high temperature is scarcely observed.
Examples of the fibrous paper used in the present invention include cellulose fibre papers such as kraft paper, condenser paper and the like, or synthetic papers prepared from polyester nonwoven fabric and the like.
The thickness of the fibrous paper employed is suitably within a range of around 10-1 50ju.
The laminated insulating paper according to the present invention is obtained by means of the adhesion of a fibrous paper or papers to at least one side of the aforesaid crosslinked silyl-modified polyolefin film which is subjected to the stretching operation as mentioned above.
Such adhesion of the fibrous paper or papers to the crosslinked silyl-modified polyolefin film is effected by, for example, pressing the paper or papers together with the film by the use of heating rolls at a temperature equal to or higher than the melting point of the crosslinked modified polyolefin.
A thickness of the laminated insulating paper consisting of the crosslinked silyl-modified polyolefin ?ilm and the fibrous paper or papers may suitably be selected within a range of 70-250,L after their adhesion together.
The laminated insulating paper thus obtained in the present invention is excellent in electrical and mechanical characteristics as well as in oil resistance, and is applicable for cable insulating layers, connecting portions or insulation reinforcing layers for the terminal portions of OF cables and POF cables, as well as for insulating layers and the like of high voltage condensers, or high voltage transformers in electrical apparatus.
Figure 1 is a cross sectional view showing an OF cable in which the aforesaid laminated insulating paper is used, wherein the OF cable 1 is manufactured in such manner that an inner semiconductive layer 3, an insulating layer 4 formed by winding the inner semiconductive layer 3 with the laminated insulating paper according to the present invention, an outer semiconductive layer 5, a shielding layer 6 composed of a wound metal tape, a wound layer 7 for suppression and a metal corrugated sheath 8 are successively disposed on a conductor 2, and at the same time the metal corrugated sheath 8 is filled with an insulating oil 9, e.g., alkylbenzene. When the OF cable thus manufactured is compared with a conventional OF cable in which the insulating layer is composed of a laminated insulating paper wherein such silyl-modified polyolefin film which has not been stretched is employed, the laminated insulating paper of this invention in the former OF cable has a high oil resistance, so that that OF cable has only a small change in its characteristics with time in respect of dielectric constant or dielectric loss tangent as well as due to bending and the like.
The following examples are presented to illustrate non-limiting embodiments of the invention.
EXAMPLE 1
Preparation of silyl-mo dified polyethylene pellets
High density polyethylene 100 parts by weight
(specified gravity: 0.965, melt index: 14)
VTMOS 2 parts by weight
DCP 0.1 parts by weight
The above ingredients were admixed with each other in a tumbler and the resulting admixture was introduced into an extruder, from which a string was extruded at a temperature of 180-1 850C, and then the string was shaped into pellets.
Preparation of master batch pellets containing a silanol condensation catalyst
High density polyethylene 100 parts by weight
(specified gravity: 0.965, melt index: 14)
DBTDL 1.0 parts by weight
Age resisting agent 1.0 parts by weight
Master batch pellets containing a silanol condensation catalyst were prepared from a mixture of the above ingredients.
Preparation of film
The silyl-modified polyethylene pellets were mixed with the master batch containing a silanol condensation catalyst in a ratio of 9 1. After completing the mixing, the mixture was immediately extruded in accordance with the T-die method to prepare several types of films having different thicknesses from each other. Each film was subjected to crosslinking by reacting with water until the gel content became 3040%. Thereafter the crosslinked film was subjected to monoaxial stretching at 1 00C by changing the draw ratio to obtain a specimen to be tested.
Properties of the sample films are as shown in the following Table 1.
TABLE 1
Heat Shrinkage ( /0) *3 Amount of '1 Degree of *2 Heat Shrinkage (O/o) Gel Sample Draw Soluble Material Swelling Content No. Ratio (%) (%) Length Breadth (ego) .~ .~ .
1 1.8 1.6 4.5 6.4 - 0.6 50 2 2.0 2.8 4.0 7.5 - 1.4 52 3 3.0 1.5 2.8 1.7 - 0.1 52 4 3.5 0.9 2.7 1.3 - O. 4 52 5 40 0.8 1.5 1.5 - 0.3 54 * 1: 100"C x 168 hrs. in dodecylbenzene
* 2: 100"C x 168 hrs., 1 kg/cm2 load in dodecylbenzene
* 3 : 100"C x 24 hrs. in atmosphere
For a number of samples, the rate of change in dimensions as well as the oil absorption in dodecylbenzene for each draw ratio thereof were measured.As a result, it was ascertained that shrinkage of a sample in the longitudinal direction disappeared at about 2.8 times the draw ratio as indicated in the accompanying Figure 2.
Preparation oflaminated insulating paper
Each of the stretched silyl-modified polyethylene films of the aforesaid samples Nos. 2, 3 and 4 was selected. Condenser papers each having a thickness of 50 L were placed on both sides of each sample film and they were pressed by means of heating rolls to become integrally affixed to each other, whereby a laminated insulating paper having a thickness of 1 80 flt was prepared.
The amounts of soluble material in the resulting laminated insulating papers with respect to dodecylbenzene is as indicated in Table 2.
TABLE 2
I Example 1 Sample Sample Sample Comparative No. 2 No. 3 No. 5 Example 1 Amount of Soluble Material (%) 100etc x 168 hrs. 1.9 1.2 0.7 2.3 (In Comparative Example 1, a laminated insulating paper in which an
unstretched, crosslinked silylnodiiied polyethylene film is utilized
was adopted.)
EXAMPLE 2
A 275 Kv class OF cable having the construction as shown in Figure 1 and detailed below was fabricated by the use of the laminated insulating paper of Example 1 prepared by utilizing the film of sample No. 5.
Conductor: 1 x 2000 mm2 (without oil path spiral tube)
Inner semiconductive layer : Carbon paper shielding 1 mm
Thickness of insulating paper wound layer: 6.5 mm
Outer semiconductive layer
Metallized shielding paper
Wound layer
Thickness of corrugated aluminum sheath :2.6 mm Flexibie vinyl chloride resin corrosion-resistant layer: 6 mm
Insulating oil : dodecylbenzene
The characteristics of the resulting OF cable were as indicated in the following Table 3.
TABLE 3
Characteristics Measured Value Insulation Resistance 1.10 x 105 (MQ.Km) Dielectric Loss Tangent 0.099.
(280 Kv, room temp.) (%) Dielectric Constant 272 A (Breakdown Voltage (Kv) 610 Impulse Breakdown Voltage C)1750 (Kv) Next, a sample as shown in Figure 3 was fabricated from the aforesaid OF cable, and the oil flow resistance of the cable was measured. In Figure 3, reference numerals 9a and 9b designate hardening resin molds, 10 an oil path, 11 a and 1 b partitions for insulating oil, and 12 a measuring cylinder.
The oil flow resistance Z was determined in accordance with the following equations:
wherein l: effective length of cable p : oil pressure Q: flow rate TI: viscosity r,: diameter of conductor r2 : outer diameter of insulating material The results measured are as shown in the following Table 4.
It is to be noted that Comparative Example 2 in Table 4 relates to an OF cable sample having the same construction as that of Example 3 which was fabricated by the use of the laminated insulating paper utilized in Comparative Example 1.
TABLE 4
Comparative Example 3 Example 2 Oil Flow Resistance 25 C 2.7 x 1011 3.2 x 1011 (cm") 100 or xafter 3.9 x 10ill 6.3 x 10 4 days As apparent from the above examples, the laminated insulating paper according to the present invention has a low dielectric constant and dielectric loss tangent, whereas it has a high dielectric breakdown strength, besides excellent oil resistance.
Accordingly, in oil-filled electrical devices, for example an OF cable in which the aforesaid laminated insulating paper of the invention is utilized, viscosity build-up of the insulating oil is small, and the insulating oil instantly moves to prevent dielectric breakdown even when the temperature of the insulating oil rises abnormally, due to short-circuiting and the like. Furthermore such an OF cable can prevent the occurence of wrinkles and buckling during bending thereof due to ply separation of the laminated insulating paper, so that the OF cable according to the present invention exhibits excellent electrical characteristics.
The embodiments described are intended to be mereiy exemplary and those skilled in the art will be able to make variations and modifications in them without department from the spirit and scope of the invention. All such modifications and variations are contemplated as falling within the scope of the
Claims (12)
1. A laminated insulating paper comprising a fibrous paper or papers and at least one sheet of a crosslinked silyl-modified polyolefin film having a gel content of 2070%, said polyolefin film having been stretched at a temperature of 800C or more and lower than the melting point thereof at a draw ratio of a value equal to or more than that at the yield point thereof, and the thus stretched polyolefin film being affixed to at least one side of said fibrous paper or papers.
2. A laminated insulating paper as defined in claim 1, said crosslinked silyl-modified polyolefin film having a gel content of 4555%.
3. A laminated insulating paper as defined in claim 1 or 2, wherein said crosslinked silyl-modified polyolefin film is stretched at a draw ratio of 2.8 times or more.
4. A laminated insulating paper as defined in any one of claims 1 to 3, wherein the thickness of said laminated insulating paper is within the range of 70-250 fll.
5. A laminated insulating paper as defined in any one of claims 1 to 4, wherein said crosslinked silyi-modified polyolefin film is a crosslinked silyl-modified polyethylene film.
6. A laminated insulating paper as defined in any one of the preceding claims wherein the fibrous paper is of cellulose fibre.
7. An oil-paper insulated electrical device comprising a conductor, a laminated insulating paper wound layer disposed on the outer circumference of said conductor, and a liquid tight sheath covering the outer circumference of said laminated insulating paper wound layer, said laminated insulating paper wound layer being of a material as claimed in any one of the preceding claims and said liquid tight sheath being filled with an insulating oil.
8. An oil-paper insulated electrical device as defined in claim 7, wherein said insulating oil is alkylbenzene.
9. An oil-paper insulated electrical device as defined in claims 7 or 8 in the form of an OF cable.
1 0. A laminated insulating paper according to claim 1 substantially as described herein with reference to Example 1.
11. An oil-paper insulated electrical device substantially as described herein with reference to
Figure 1.
12. An oil-paper insulated electrical device substantially as described herein with reference to
Example 2.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56065550A JPS57180814A (en) | 1981-04-30 | 1981-04-30 | Laminated insulating paper and oil paper insulated electric equipment using same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2100188A true GB2100188A (en) | 1982-12-22 |
| GB2100188B GB2100188B (en) | 1984-10-31 |
Family
ID=13290228
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8211545A Expired GB2100188B (en) | 1981-04-30 | 1982-04-21 | Laminated insulating paper and its use |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS57180814A (en) |
| GB (1) | GB2100188B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2132554A (en) * | 1982-12-17 | 1984-07-11 | British United Shoe Machinery | Shoe insole and the manufacture thereof |
| WO1984003240A1 (en) * | 1983-03-07 | 1984-08-30 | Neste Oy | Compound film containing olefin |
| GB2146290A (en) * | 1983-02-17 | 1985-04-17 | Neste Oy | Compound film containing olefin |
| WO1999033071A1 (en) * | 1997-12-22 | 1999-07-01 | Abb Ab | A method for manufacturing an electric device having an insulation system impregnated with a dielectric fluid |
-
1981
- 1981-04-30 JP JP56065550A patent/JPS57180814A/en active Pending
-
1982
- 1982-04-21 GB GB8211545A patent/GB2100188B/en not_active Expired
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2132554A (en) * | 1982-12-17 | 1984-07-11 | British United Shoe Machinery | Shoe insole and the manufacture thereof |
| GB2146290A (en) * | 1983-02-17 | 1985-04-17 | Neste Oy | Compound film containing olefin |
| WO1984003240A1 (en) * | 1983-03-07 | 1984-08-30 | Neste Oy | Compound film containing olefin |
| US4639398A (en) * | 1983-03-07 | 1987-01-27 | Neste Oy | Compound film containing olefin |
| WO1999033071A1 (en) * | 1997-12-22 | 1999-07-01 | Abb Ab | A method for manufacturing an electric device having an insulation system impregnated with a dielectric fluid |
| US6391447B1 (en) * | 1997-12-22 | 2002-05-21 | Abb Ab | Method for manufacturing an electric device having an insulation system impregnated with a dielectric fluid |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57180814A (en) | 1982-11-08 |
| GB2100188B (en) | 1984-10-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3683104A (en) | Heat resistant cable | |
| US4029830A (en) | Method of manufacturing insulated electric power cables | |
| US4096346A (en) | Wire and cable | |
| US4322575A (en) | Flame retardant compositions | |
| US3793476A (en) | Insulated conductor with a strippable layer | |
| US4237334A (en) | Laminated insulating paper and oil-filled cable insulated thereby | |
| US4469539A (en) | Process for continuous production of a multilayer electric cable | |
| US4520230A (en) | Cross-linked polyethylene insulated power cable with improved electric breakdown strength and method for manufacturing the same | |
| US4554173A (en) | Method for manufacturing flame-retardant insulated wire and cable for nuclear power stations | |
| US4469538A (en) | Process for continuous production of a multilayer electric cable and materials therefor | |
| GB2100188A (en) | Laminated insulating paper and its use | |
| GB2059140A (en) | Flame retardant electric cables | |
| US3717522A (en) | Method for forming a cross-linked polyethylene insulator | |
| US4220615A (en) | Method for the manufacture of a power cable | |
| JPS6054732B2 (en) | Insulator for oil-immersed insulation | |
| DE3312794A1 (en) | Polymer-insulated electrical power cable, in particular high-voltage cable | |
| DE2753866A1 (en) | INSULATION FOR ELECTRIC BODIES, IN PARTICULAR FOR ELECTRIC CABLES | |
| JPS58103714A (en) | Laminated insulating paper and oil paper insulated electric device using same | |
| US4215086A (en) | Method of making flame retardant EPR unipass telephone drop wire | |
| JPH0765633A (en) | Dc cable | |
| JP3157416B2 (en) | Silicone-grafted polyolefin resin and heat-resistant electric wire coated with silicone-grafted polyolefin resin as insulator | |
| JP3021541B2 (en) | Rubber / plastic insulated power cable | |
| JPH10264174A (en) | Vulcanizing coating material and vulcanizing method using the material | |
| JPS5951413A (en) | Laminated insulating paper and oil-immersed insulated electric device using same | |
| JPS5918507A (en) | Sheet-like electric insulator and insulated wire |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19990421 |