GB1568907A - Planar resistance-heating elements - Google Patents
Planar resistance-heating elements Download PDFInfo
- Publication number
- GB1568907A GB1568907A GB15781/77A GB1578177A GB1568907A GB 1568907 A GB1568907 A GB 1568907A GB 15781/77 A GB15781/77 A GB 15781/77A GB 1578177 A GB1578177 A GB 1578177A GB 1568907 A GB1568907 A GB 1568907A
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- United Kingdom
- Prior art keywords
- resistor
- adhesive
- areas
- insulating material
- resistance
- 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.)
- Expired
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- 238000010438 heat treatment Methods 0.000 title claims description 27
- 239000011810 insulating material Substances 0.000 claims description 41
- 229920001296 polysiloxane Polymers 0.000 claims description 34
- 239000000853 adhesive Substances 0.000 claims description 32
- 230000001070 adhesive effect Effects 0.000 claims description 32
- 229920001971 elastomer Polymers 0.000 claims description 23
- 239000000806 elastomer Substances 0.000 claims description 22
- 239000000203 mixture Substances 0.000 claims description 19
- 239000011159 matrix material Substances 0.000 claims description 13
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 7
- 239000012790 adhesive layer Substances 0.000 claims description 7
- 239000010949 copper Substances 0.000 claims description 7
- 229910052802 copper Inorganic materials 0.000 claims description 7
- -1 polyethylene terephthalate Polymers 0.000 claims description 7
- 150000003961 organosilicon compounds Chemical class 0.000 claims description 6
- 229920000139 polyethylene terephthalate Polymers 0.000 claims description 6
- 239000005020 polyethylene terephthalate Substances 0.000 claims description 6
- 239000002245 particle Substances 0.000 claims description 5
- 239000004820 Pressure-sensitive adhesive Substances 0.000 claims description 4
- 125000003668 acetyloxy group Chemical group [H]C([H])([H])C(=O)O[*] 0.000 claims description 4
- 239000004033 plastic Substances 0.000 claims description 3
- 229920003023 plastic Polymers 0.000 claims description 3
- 125000004213 tert-butoxy group Chemical group [H]C([H])([H])C(O*)(C([H])([H])[H])C([H])([H])[H] 0.000 claims description 3
- 239000011248 coating agent Substances 0.000 claims description 2
- 238000000576 coating method Methods 0.000 claims description 2
- 238000000034 method Methods 0.000 description 4
- 239000004020 conductor Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 125000003342 alkenyl group Chemical group 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000004205 dimethyl polysiloxane Substances 0.000 description 2
- 235000013870 dimethyl polysiloxane Nutrition 0.000 description 2
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 description 2
- 229920000728 polyester Polymers 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- JJLKTTCRRLHVGL-UHFFFAOYSA-L [acetyloxy(dibutyl)stannyl] acetate Chemical compound CC([O-])=O.CC([O-])=O.CCCC[Sn+2]CCCC JJLKTTCRRLHVGL-UHFFFAOYSA-L 0.000 description 1
- TVJPBVNWVPUZBM-UHFFFAOYSA-N [diacetyloxy(methyl)silyl] acetate Chemical compound CC(=O)O[Si](C)(OC(C)=O)OC(C)=O TVJPBVNWVPUZBM-UHFFFAOYSA-N 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000004411 aluminium Substances 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
- 125000003277 amino group Chemical group 0.000 description 1
- CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000007646 gravure printing Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 150000003949 imides Chemical class 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 235000011837 pasties Nutrition 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229920000412 polyarylene Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000012744 reinforcing agent Substances 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 238000009958 sewing Methods 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 229910000679 solder Inorganic materials 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/20—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
- H05B3/34—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater flexible, e.g. heating nets or webs
- H05B3/36—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater flexible, e.g. heating nets or webs heating conductor embedded in insulating material
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
- H05B3/12—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material
- H05B3/14—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material the material being non-metallic
- H05B3/146—Conductive polymers, e.g. polyethylene, thermoplastics
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/20—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
- H05B3/22—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible
- H05B3/28—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible heating conductor embedded in insulating material
- H05B3/283—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible heating conductor embedded in insulating material the insulating material being an inorganic material, e.g. ceramic
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/20—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
- H05B3/22—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible
- H05B3/28—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible heating conductor embedded in insulating material
- H05B3/286—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible heating conductor embedded in insulating material the insulating material being an organic material, e.g. plastic
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
- H05B2203/011—Heaters using laterally extending conductive material as connecting means
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
- H05B2203/017—Manufacturing methods or apparatus for heaters
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Inorganic Chemistry (AREA)
- Surface Heating Bodies (AREA)
- Adhesives Or Adhesive Processes (AREA)
- Organic Insulating Materials (AREA)
- Insulating Bodies (AREA)
- Laminated Bodies (AREA)
Description
(54) PLANAR RESISTANCE-HEATING ELEMENTS
(71) We, WACKER-CHEMIE GMBH., a body corporate organised according to the laws of the Federal Republic of Germany, of 8 München 22, Prinzregentenstrasse 22, Federal
Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:
The present invention relates to planar resistance-heating elements and, more particularly, to a method of affixing an insulating material to a resistor comprising conductive particles dispersed in an organopolysiloxane elastomer matrix in such an element.
A planar resistance-heating element of the type to which the invention relates comprises a sheet-form resistor comprising conductive particules dispersed in a matrix, and two electrodes, suitably in the form of copper strips, are secured to opposed edges of the resistor for connection to an electric current supply. A sheet-form insulating material, for example a polyester sheet, is arranged against one or both sides of the resistor.
When the matrix of the resistor is of an organic (as distinct from organosilicon) polymeric material, the insulating material may be secured in position against the resistor simply by means of a uniform adhesive layer between the insulating material and the resistor, the said layer of course being adhesive toward both the insulating material and the resistor. For example, an adhesive may be uniformly coated onto one side of the insulating material which may then be pressed against one side of the resistor, with the application of heat, if necessary, to cure the adhesive. The adhesive may, for example, be one based on polyethylene or on a monomeric or polymeric acrylate.
On the other hand, when the matrix of the resistor is an organopolysiloxane elastomer, the use of a uniform adhesive layer between the resistor and the insulating material generally causes an uncontrollable alteration in the resistance of the resistor, which is generally manifested in the form of a considerable increase in the resistance of the resistor. Planar resistance-heating elements in which the matrix is of an organopolysiloxane elastomer have therefore been manufactured by loosely sandwiching the resistor between two insulating sheets each slightly larger than the resistor and securing the two sheets together along their edges where they project beyond the edges of the resistor thus hermetically encapsulating the resistor between the two insulating sheets without actually securing the resistor to the insulating sheets (cf.British Patent Specification No. 1 455 376, Examples 3 and 4). Bends, breaks and other damage causing short-circuiting can, however, easily occur in planar resistance-heating elements insulated in this manner that are bigger than about 30 cm x 100 cm.
Another method by which a planar resistance-heating element in which the matrix of the resistor is of an organopolysiloxane elastomer may be manufactured is by sewing the insulating material to the resistor and covering the seams with insulating tape. The resulting planar resistance-heating elements, however, have a reduced tensile strength and tear resistance because of the holes in the seams and, moreover, when used at power densities of more than about 200 W/m2, they tend to burn through at the seams.
Attempts have also been made to manufacture a planar resistance-heating element in which the matrix of the resistor is of an organopolysiloxane elastomer by securing the insulating material to the resistor by means of strips adhesive on both sides arranged between the insulating material and the resistor in a direction perpendicular to the direction of the current when the resistor is in use. It was found, however, that, after a short period of operation, the resistors became destroyed in the regions where the adhesive strips lay.
The present invention provides a planar resistance-heating element, which comprises a sheet-form resistor comprising conductive particles dispersed in a matrix of an organopolysiloxane elastomer, with two electrodes secured to opposed edges of the resistor for connection to an electric current supply, and a sheet-form insulating material arranged against one or both sides of the resistor and adhesively secured thereto in a plurality of spaced-apart areas, the said areas being substantially circular or substantially equilateral polygonal or substantially in the form of strips lying in the direction in which the current will flow when the element is in use.
Planar resistance-heating elements according to the invention substantially overcome the respective disadvantages of planar resistance-heating elements in which the insulating material and the resistor are secured together by one of the methods mentioned above.
The sheet-form resistor used in a planar resistance-heating element according to the invention may be any such resistor including a matrix of an organopolysiloxane elastomer as could be used in previous planar resistance-heating elements. The resistor comprises an organopolysiloxane elastomer in which is dispersed finely divided electrically conductive material, which may be a pulverulent metal (for example, silver, copper, aluminium or iron) or another pulverulent electrically conductive substance (for example, silicon, silicon carbide, graphite or carbon black) or a mixture of two or more such pulverulent materials. The resistor is, of course, electrically conductive.The organopolysiloxane elastomer containing the electrically conductive material may be self-supporting, or the sheet-form resistor may additionally comprise a reinforcing agent, for example a glass-fibre fabric or fleece.
Two electrodes are secured to opposed edges of the resistor and this may be effected in a conventional manner. The electrodes may be copper strips and they may be secured to the resistor by means of an electrically conductive organopolysiloxane composition curable to an elastomer, for example a composition such as that described and claimed in British Patent
Specification No. 1 455 376. The said edges must, of course, not be firmly secured to the insulating material. When the element is in use, the electric current will generally flow in a direction perpendicular to that in which the electrodes extend.
The sheet-form insulating material used in a planar resistance-heating element according to the invention may be any such insulating material as could be used in previous planar resistance-heating elements. The insulating material is preferably a plastics sheet of, for example, a polyester (for example, polyethylene terephthalate), a polyarylene imide, an organopolysiloxane or polyhydantoin.
The adhesive securement of the insulating material to the resistor may be achieved simply by applying an adhesive layer to appropriate areas of the insulating material and/or the resistor, placing the insulating material and the resistor together and curing the adhesive. The application of the adhesive layer to the insulating material and/or to the resistor may be effected in any manner conventional for the application of a liquid or pasty substance to a plurality of spaced-apart local areas, for example by gravure printing, by silk-screen printing, or by hand.
The adhesive securement may, alternatively, be effected by means of a plurality of carrier sheets, such as carrier strips, coated on both sides with a pressure-sensitive adhesive and arranged between the insulating material and the resistor.
The adhesive - whether applied directly to the insulating material and/or the resistor or whether present on a carrier sheet as a pressure-sensitive adhesive - advantageously comprises an organopolysiloxane composition curable to form an elastomer. The organopolysiloxane may be one in which all organic radicals bonded to silicon atoms via a silicon bond are unsubstituted or substituted hydrocarbon radicals having up to 18 carbon atoms or it may be a modified organopolysiloxane, which may, for example, have been manufactured in a conventional manner by grafting one or more aliphatically unsaturated monomers, for example a mixture of styrene and n-butyl acrylate, onto an organopolysiloxane by means of free-radical polymerisation.
Various types of organopolysiloxane compositions curable to elastomers are known and may be used as the adhesive. The organopolysiloxane composition is preferably one containing an organosilicon compound having at least three hydrolysable groups per molecule (for example acetoxy groups, alkoxy groups and amino groups), especially one containing an organosilicon compound having a total of at least three tert-butoxy and acetoxy groups, because such a composition is readily available and generally gives adhesion to both the resistor and the insulating material. The curing of such a composition may be effected at room temperature in the presence of water, normal atmospheric moisture generally being sufficient for this purpose. The organopolysiloxane composition may, however, alternatively be one containing silicon-bonded hydrogen atoms, silicon-bonded alkenyl groups (especially vinyl groups) and a catalyst promoting the addition of silicon-bonded hydrogen atoms to alkenyl groups (especially a catalyst comprising platinum or a compound or complex thereof). Such a composition may be cured at a temperature within the range of from room temperature to 1500C. A further alternative is for the organopolysiloxane to be one that is curable by means of free radicals, for example by heating the composition to a temperature within the range of from 100 to 2000C or by subjecting the composition to high-energy radiation, for example gamma -radiation.
The adhesive may contain a finely divided electrically conductive material in order to render it electrically conductive, examples of such materials being those mentioned above, especially carbon black.
The adhesive is preferably free or substantially free of solvent.
The insulating material and the resistor are secured together in a plurality of spaced-apart areas, which are preferably substantially circular areas or substantially equilateral polygonal areas (for example, substantially equilateral triangular, quadrilateral, pentagonal or hexagonal areas). These substantially circular or polygonal areas preferably are arranged uniformly (that is, substantially equidistant from one another) over the entire surface of the resistor or are arranged at intervals along a plurality of lines, which lines extend in the direction in which the current will flow when the element is in use. The said spaced-apart areas may, alternatively, be substantially in the form of strips lying in the direction in which the current will flow when the element is in use. Such strips may be straight or wavy.
The diameter of the substantially circular areas, the average diameter of the substantially equilateral polygonal areas (that is, the average distance from edge to edge through the centre point), and the width of the strip-shaped areas is advantageously within the range of from 0.1 to 100 mm, preferably from 1 to 10 mm. The distance between the edges of adjacent spaced-apart areas is preferably not less than 5 mm, although the actual distance used in any particular element, as well as the number of spaced-apart areas per unit surface area, will depend on the desired degree of securement of the insulating material to the resistor. The thickness of the adhesive layer is preferably within the range of from 20 to 1000 ,am.
A planar resistance-heating element according to the invention may be operated by either direct or alternating current. It is suitable for all uses to which previous planar resistanceheating elements could be put, for example for heating cylindrical water heaters.
Two forms of planar resistance-heating elements according to the invention will now be described, by way of example only, with reference to the accompanying drawings, in which
Fig. 1 shows a schematic perspective view of one form of planar resistance-heating element according to the invention with the insulating material partly peeled back and
Fig. 2 shows a similar view of a second form of planar resistance-heating element according to the invention.
Each resistance-heating element (Figs. 1 and 2) comprises a sheet-form resistor 1, comprising conductive particules dispersed in a matrix of an organopolysiloxane elastomer, sandwiched between a folded single sheet of insulating material 4. Two copper strips 3,3', serving as electrodes, are secured to opposed edges of the resistor 1 and are connectable to an electric current supply via wires 6 joined thereto by solder joints 5. In the element shown in Fig. 1, the insulating material 4 is adhesively secured to the resistor 1 in a plurality of substantially circular spaced-apart areas 2a; whereas in the element shown in Fig. 2, the insulating material 4 is adhesively secured to the resistor 1 in a plurality of spaced-apart areas 2b in the form of strips lying in the direction in which the current will flow when the element is in use.
The following Example 1 illustrates the manufacture of a planar resistance-heating element according to the invention and the properties thereof, and Examples 2 and 3 illustrate, for comparison purposes, the manufacture of prior-art planar resistance-heating elements.
The sheet-form resistor used in all examples comprised conductive particles dispersed in a matrix of an organopolysiloxane elastomer, and measured 30 cm x 150 cm. It had a square resistance of 75 ohms. A copper strip was secured to each of the two longer edges of the resistor to serve as an electrode, and the resulting resistor had a resistance of 14.8 ohms.
Adhesive was applied by hand to the resistor or to the insulating material in the manner described in the respective examples, whereafter a sheet of polyethylene terephthalate (insulating material) was immediately pressed against each side of the resistor by means of a rubber roller. The adhesive was cured for 24 h at room temperature. The resistance of the insulated element was then measured.
The adhesive used in each case consisted of an organopolysiloxane composition produced by mixing 100 g of a dimethylpolysiloxane having a silicon-bonded hydroxy group in each terminal unit (viscosity 74 000 cP at 25"C); 35 g of a trimethylsiloxy-terminated dimethylpolysiloxane (viscosity 33 cP at 25"C); 6 g of the reaction product of 85 g of methyltriacetoxysilane and 15 g of a liquid consisting of a mixture of compounds with the average formula [(CH3)3co]asi(ooccH3)4 a in which a is approximately 1.5; and 2 drops of di-n-butyltin diacetate.
Example 1
In this example, the adhesive was applied to a plurality of substantially circular areas on both sides of the resistor, each having a diameter of about 3 to 5 mm and each spaced about 5 cm from adjacent areas. The thickness of the adhesive coating was about 400 ,um.
Immediately after the curing of the adhesive, the sheets of polyethylene terephthalate were fold-free and firmly secured to the resistor. The insulated element had a resistance of 14.8 ohms and a power of about 3.2 kW. After 500 h of operation at 220 volts, no changes were detectable in the element.
Example 2
In this example, the adhesive was uniformly applied to the whole of one side of each of the two sheets of polyethylene terephthalate.
Immediately after the curing of the adhesive, the insulated element had a resistance of 42 ohms.
Example 3
In this example, the adhesive was applied on each side of the resistor in a strip 1 cm wide, parallel to the copper electrodes (that is perpendicular to the direction of the current) and in the middle of the resistor approximately equidistant from each electrode.
Immediately after the curing of the adhesive, the insulated element had a resistance of 15.3 ohms and, after only 30 h of operation at 220 volts, this had increased to about 30 ohms.
During the following 50 h of operation, the power input of the element dropped continuously and, after about 100 h of operation, the element had been completely destroyed.
WHAT WE CLAIM IS:
1. A planar resistance-heating element, which comprises a sheet-form resistor comprising conductive particles dispersed in a matrix of an organopolysiloxane elastomer, with two electrodes secured to opposed edges of the resistor for connection to an electric current supply, and a sheet-form insulating material arranged against one or both sides of the resistor and adhesively secured thereto in a plurality of spaced-apart areas, the said areas being substantially circular or substantially equilateral polygonal or substantially in the form of strips lying in the direction in which the current will flow when the element is in use.
2. An element as claimed in claim 1, wherein the insulating material is a plastics sheet.
3. An element as claimed in claim 1 or claim 2, wherein the diameter of the substantially circular areas, the average diameter (as hereinbefore defined) of the substantially equilateral polygonal areas or the width of the strip-shaped areas, as the case may be, is within the range of from 0.1 to 100 mm.
4. An element as claimed in claim 3, wherein the diameter of the substantially circular areas, the average diameter (as hereinbefore defined) of the substantially equilateral polygonal areas or the width of the strip-shaped areas, as the case may be, is within the range of from 1 to 10 mm.
5. An element as claimed in any one of claims 1 to 5, wherein the distance between the edges of adjacent spaced-apart areas is not less than 5 mm.
6. An element as claimed in any one of claims 1 to 5, wherein the insulating material is adhesively secured to the resistor by means of an adhesive layer having a thickness within the range of from 20 to 1000 ijm.
7. An element as claimed in any one of claims 1 to 5, wherein the insulating material is adhesively secured to the resistor by means of a plurality of carrier sheets each coated on both sides with a pressure-sensitive adhesive.
8. An element as claimed in any one of claims 1 to 7, wherein the insulating material is adhesively secured to the resistor by means of an adhesive comprising an organopolysiloxane elastomer.
9. An element as claimed in claim 8, wherein the organopolysiloxane elastomer has been produced by curing an organopolysiloxane composition containing an organosilicon compound having at least three hydrolysable groups per molecule.
10. An element as claimed in claim 9, wherein the organopolysiloxane elastomer has been produced by curing an organopolysiloxane composition containing an organosilicon compound having a total of at least three tert-butoxy and acetoxy groups per molecule.
11. An element as claimed in claim 1, substantially as described herein with reference to, and as shown in, Fig. 1 or Fig. 2 of the accompanying drawings.
12. An element as claimed in claim 1, substantially as described in Example 1 herein.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (12)
1. A planar resistance-heating element, which comprises a sheet-form resistor comprising conductive particles dispersed in a matrix of an organopolysiloxane elastomer, with two electrodes secured to opposed edges of the resistor for connection to an electric current supply, and a sheet-form insulating material arranged against one or both sides of the resistor and adhesively secured thereto in a plurality of spaced-apart areas, the said areas being substantially circular or substantially equilateral polygonal or substantially in the form of strips lying in the direction in which the current will flow when the element is in use.
2. An element as claimed in claim 1, wherein the insulating material is a plastics sheet.
3. An element as claimed in claim 1 or claim 2, wherein the diameter of the substantially circular areas, the average diameter (as hereinbefore defined) of the substantially equilateral polygonal areas or the width of the strip-shaped areas, as the case may be, is within the range of from 0.1 to 100 mm.
4. An element as claimed in claim 3, wherein the diameter of the substantially circular areas, the average diameter (as hereinbefore defined) of the substantially equilateral polygonal areas or the width of the strip-shaped areas, as the case may be, is within the range of from 1 to 10 mm.
5. An element as claimed in any one of claims 1 to 5, wherein the distance between the edges of adjacent spaced-apart areas is not less than 5 mm.
6. An element as claimed in any one of claims 1 to 5, wherein the insulating material is adhesively secured to the resistor by means of an adhesive layer having a thickness within the range of from 20 to 1000 ijm.
7. An element as claimed in any one of claims 1 to 5, wherein the insulating material is adhesively secured to the resistor by means of a plurality of carrier sheets each coated on both sides with a pressure-sensitive adhesive.
8. An element as claimed in any one of claims 1 to 7, wherein the insulating material is adhesively secured to the resistor by means of an adhesive comprising an organopolysiloxane elastomer.
9. An element as claimed in claim 8, wherein the organopolysiloxane elastomer has been produced by curing an organopolysiloxane composition containing an organosilicon compound having at least three hydrolysable groups per molecule.
10. An element as claimed in claim 9, wherein the organopolysiloxane elastomer has been produced by curing an organopolysiloxane composition containing an organosilicon compound having a total of at least three tert-butoxy and acetoxy groups per molecule.
11. An element as claimed in claim 1, substantially as described herein with reference to, and as shown in, Fig. 1 or Fig. 2 of the accompanying drawings.
12. An element as claimed in claim 1, substantially as described in Example 1 herein.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2616855A DE2616855C3 (en) | 1976-04-15 | 1976-04-15 | Process for isolating organopolysiloxane elastomer as a binder-containing resistor material from surface heating resistors |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1568907A true GB1568907A (en) | 1980-06-11 |
Family
ID=5975564
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB15781/77A Expired GB1568907A (en) | 1976-04-15 | 1977-04-15 | Planar resistance-heating elements |
Country Status (5)
| Country | Link |
|---|---|
| AT (1) | ATA263077A (en) |
| DE (1) | DE2616855C3 (en) |
| FR (1) | FR2361034A1 (en) |
| GB (1) | GB1568907A (en) |
| SE (1) | SE7704320L (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2196818A (en) * | 1986-10-13 | 1988-05-05 | Herush Electrical | Heating pad |
| EP1398996A1 (en) * | 2002-09-13 | 2004-03-17 | Bleckmann GmbH | Flat heating element for the direct heating of a medium |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4523085A (en) * | 1980-08-28 | 1985-06-11 | Flexwatt Corporation | Electrical heating device |
| US4656339A (en) * | 1980-08-28 | 1987-04-07 | Flexwatt Corporation | Electrical resistance heater |
| DE3703939A1 (en) * | 1987-02-09 | 1988-08-18 | Ruthenberg Gmbh Waermetechnik | AREA HEATING ELEMENT FOR INSTALLATION IN VEHICLE SEATS |
| DE3717540A1 (en) * | 1987-05-25 | 1988-12-15 | Autz & Herrmann Maschf | Heat exchanger to be arranged on a wall or door of a switch cabinet |
| DE19714018A1 (en) * | 1997-04-04 | 1998-10-08 | Schittko Gert | Flexible heating floor-mat to provide underfoot heating for cold places e.g. public buildings |
| US6489595B1 (en) | 2001-03-12 | 2002-12-03 | Check Corporation | Electric heater for a seat assembly |
| DE10130511C5 (en) * | 2001-06-25 | 2011-04-14 | Bleckmann Gmbh & Co. Kg | Heating device for heating a liquid or gaseous medium |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3344385A (en) * | 1965-01-04 | 1967-09-26 | Dow Corning | Flexible resistance element with flexible and stretchable terminal electrodes |
| DE2307776C3 (en) * | 1973-02-16 | 1979-08-30 | Wacker-Chemie Gmbh, 8000 Muenchen | Use of mixtures based on organopolysuoxanes as adhesives |
-
1976
- 1976-04-15 DE DE2616855A patent/DE2616855C3/en not_active Expired
-
1977
- 1977-04-14 AT AT0263077A patent/ATA263077A/en not_active Application Discontinuation
- 1977-04-14 SE SE7704320A patent/SE7704320L/en unknown
- 1977-04-14 FR FR7711246A patent/FR2361034A1/en active Granted
- 1977-04-15 GB GB15781/77A patent/GB1568907A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2196818A (en) * | 1986-10-13 | 1988-05-05 | Herush Electrical | Heating pad |
| GB2196818B (en) * | 1986-10-13 | 1990-03-28 | Herush Electrical | Electrical heaters |
| EP1398996A1 (en) * | 2002-09-13 | 2004-03-17 | Bleckmann GmbH | Flat heating element for the direct heating of a medium |
Also Published As
| Publication number | Publication date |
|---|---|
| ATA263077A (en) | 1982-03-15 |
| DE2616855A1 (en) | 1977-11-03 |
| SE7704320L (en) | 1977-10-16 |
| DE2616855B2 (en) | 1981-02-26 |
| DE2616855C3 (en) | 1981-11-12 |
| FR2361034A1 (en) | 1978-03-03 |
| FR2361034B1 (en) | 1981-01-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |