Polymer composition

 

The invention relates to the field of electrical engineering, in particular to polymeric compositions containing at least one essentially non-conductive polymer and at least one electrically conductive filler, in the form of granules, and the granules preferably have a size in the range up to 1 mm, more preferably between 0.04 and 0.2 mm at a volume ratio of the conductor and polymer preferably from 3:1 to 15:1. The technical result from the proposed use of the composition is the ability to control load positive temperature coefficient and the ability to transfer significant electric current. 21 C.p. f-crystals, 1 Il., table 1.

Technical field the Present invention relates to polymeric compositions containing finely ground electrical conductor, especially to such compositions useful in physical form.

The prior art that the compositions were asked to use the devices, regulating or switching the electric current for the exclusion or limitation of disadvantages such as the occurrence of transient or sparks, accompanying a conventional mechanical switches.

In particular, in finding the m WO 98/33193 disclosed the composition and switches on its basis. In this application first described granular composition comprising a polymer and conductive filler. The present invention relates to polymer compositions in such form and for further improvements.

In the publication DE-A-4315382, which corresponds to US-A-5589222, discloses a fluid hydrophobic granules containing hydrophilic inorganic powder and from 0.03 to 15% wt./weight. hydrophobic organic polysiloxane, as well as the retrieval method by mixing the powder into a pellet with an aqueous emulsion of the organic polysiloxane and drying the resulting product at elevated temperatures. Among these powders include metals and alloys. Granules, however, are designed for use in enamelling; in the description there are no indications that they could form part of an electric circuit or that they could be electrically insulating in the state of rest, but conductive when they are subjected to mechanical deformation or electrostatic fields.

Summary of the invention the Present invention provides a composite electrical conductor containing granules, each of which contains one or more electrically non-conductive polymers and particles real the seeds of the specified metals and alloys, characterized in that the particles of the electrically conductive filler are dendritic, fibrous or pointed structure, due to which these granules are electrically insulating at rest, but conductive under the influence of mechanical deformation or electrostatic charge.

Granules typically have a size in the range of from 0.04 to 0.2 mm, Thus, the smaller the granules are powders. These ranges are based on the measurement of larger diameter pellets, if they do not have the correct spherical shape. To meet the requirements of the consumer granules may have a size distribution, for example, is close to the distribution of the Poisson law, or can be sifted to achieve asymmetric distribution or a narrow distribution (for example, the large granules not more than twice the smallest granules), or fractionated so that the small granules fill the volume between the larger granules.

Inside the granule volumetric ratio of conductor: polymer (the amount of bulk material: the amount of solid carrier without voids) is preferably 3:1. For the ratio of the conducting medium to the polymer requires small changes for the local energies of various conductive oxides and other present solid materials. Changes in this ratio have an impact on the characteristics of the charge associated with the piezoelectric effect, the total interval resistance, recovery hysteresis and sensitivity of the granules to the pressure (the squeeze).

Typically, the conductive material may constitute one or more conductive or semi-conductive metals, metal alloys and oxides of these metals and alloys. Thus, the conductive material preferably is selected from powdered forms of metal elements or conductive alloy, or restored oxides separately and together. More specifically, it represents one or more elements from among titanium, tantalum, zirconium, vanadium, niobium, hafnium, aluminum, silicon, tin, chromium, molybdenum, tungsten, lead, manganese, beryllium, iron, cobalt, Nickel, platinum, palladium, osmium, iridium, rhenium, technetium, rhodium, ruthenium, gold, silver, cadmium, copper, zinc, germanium, arsenic, antimony, bismuth, boron, scandium and metals of the group of lanthanides and actinides. Conductive filler may be an essential element in the non-oxidized state; or it can represent a layer on the raw core of powder, granules, fibers or other defined establet a, for example, the titanium diboride.

The microstructure of the particles of the conductor is of great importance. That is, dendritic (tree-like), fiber and having pointed projections form conductive materials, as shown, provide formation is particularly sensitive granules when they are covered with a polymer, such as silicone. Typically, the surface of the particles of the conductor is made rough by using smaller and forming a pointed protrusions powders, providing more sensitive granules. Preferably, the particles contain a metal with at least one of the following characteristics: (1) surface structure with gabled projections and/or dendritic structure; (2) fibrous structure with three-dimensional capodanno mesh balls with pointed projections, and cross-section of the chain have an average of 2.5-3.5 µm and a length of more than 15-20 microns.

Usually the particles of the conductor have these characteristics before mixing with the polymer, and the mixture is adjusted to essentially save them.

As described below, the preferred particles of the conductor containing Nickel metal derived from carbonyl compounds. Another example is the dendritic is the limit, the polymer or its precursor must be available in sufficient mobile form to allow the introduction of the particles of the conductor. In extreme cases it can be a fully or partially utverzhdennuyu resin, such as formaldehyde condensate, epoxy resin, maleinimide resin or three-dimensional olefinic resin. Polymers having elasticity, such as linear thermoplastics, find more General application. Very suitable polymeric component is an elastomer. Since elastomers are preferred in some composites containing granules, they will be additionally described below.

The invention provides a method of manufacturing granules by mixing particles of a conductor with a polymer in liquid form under the conditions of granulometry. The liquid form of the polymer may constitute, for example, the precursor is subjected to polymerization or cross-linking under granulometry or later. The liquid form means having fluidity sufficient for mixing with the particles of the conductor. The polymer may be very viscous. To modify the viscosity of the polymer as an auxiliary additive for mixing may be a liquid. It can be D. must be chemically inert with respect to the conductor and polymer. Preferably it is volatile, i.e. it has a boiling point at atmospheric pressure below 120oIn order to facilitate its removal during mixing or after mixing. For these purposes very well suited hydrocarbons, such as petroleum distillates. Before mixing or blending can be added gidrofobiziruyuschey agent. I believe that it works by replacing the absorbed water from the surface of the blend components, for example particles of the conductor, solid auxiliary additives, which are described below, particularly colloidal silicon dioxide, and perhaps newly-opened polymer and the newly formed granules. The agent can also act as a lubricating substance that reduces friction at the surfaces of the mixer. As it performs its function through the formation of a very thin monomolecular layers, the amount used is very small and is, for example, 10-1000 M. D. (weight/weight) based on the mixture. Examples of such agents are liquid hydrocarbons containing groups that promote chemisorption on metals, and fluorocarbons.

Granules are prepared by coating on the conductive particle layer of polymer in the controlled mixing to the Oia and eliminate extra effort which, as installed, has a damaging effect on the electrical properties of the final polymer composition. The ratio of filler, binder, mixing energy, time, shear rate, temperature and pressure determines the distribution of particle sizes and Electromechanical properties of the resulting granules. Apparently, the particles of the conductor act as nuclei for the formation of granules. Such a mixture preferably at low shifting effort so that the particles of the conductor remained structurally intact. Preferably can be used as pan granulator, pug mill, a coaxial cylindrical mixer (rotational ablation). During the formation of granules, as it turns out, the total shear load may be of the same order as in the production of bulk composition, but applied at a higher intensity for a shorter time.

The formation of granules preferably accompanied by some cross-linking of the polymer. The formulation of the polymer chosen, and the conditions of the mixture is adjusted to a gap of a mixture of granules was synchronized with the cross-linking of polymer sufficient to achieve non-stick sauce is the temperature (RTV-silicone). If necessary, the process can be adjusted to obtain a precursor granules, in which the polymer may be subjected to additional cross-linking for improved elastomeric properties. The use of silicone, cured at high temperature (HTV-silicone), provides more opportunities for making such precursors. A very suitable silicone is silicone, subjected to high shrinkage, for example, by 10-20% cross-linking. This allows us to obtain a relatively high volume ratio of the conductor to the polymer granules without uncomfortable high attitude at the beginning of mixing.

If increased content of silicone in the mix, the sensitivity decreases and increases agglomeration. If you want a high content of silicone, the silicone may be applied to a pre-obtained granules with low content of silicone. When a rotational ablation gap that defines the position of the gun relative to the mortar, and the pressure applied to the pistil, mechanically regulated to achieve the desired conditions. This pressure affects the time required to achieve a granular condition, and has a value for the thickness of the coating, the final granule size and degree of hypertension is

The resulting pellets may be crushed to the desired size. They can also be sorted to separate, if necessary, agglomerates of various sizes. Granules of different sizes exhibit different sensitivity; granules of different sizes can be separated and again mixed in different proportions to change the ultimate sensitivity of the composite granules. Also found it possible to combine different conductive materials, conductive, semi-conductive and non-conductive powders, to granulometry in the sintering process/coating to obtain the desired conductivity and other electrical and mechanical properties of the resulting granulated form.

The invention also provides a composite containing granules. Typically, the granules can be used by placing them in a device that restricts peripheral movement, but allows the input electrical or mechanical pressure to activate it. They can be mixed with other block or foamed polymers or put on them with the formation of solid, semi-stretch or elastic composite structures. For one type of structure of the pellets can be extruded or pressed into PNY or turned into powder by cryogenic method. The energy reported in the process of mixing and molding the polymer composition in the uncured state may, however, affect the physical and electrical properties of the composite.

For the second type of composite granules can be associated with the supporting means. This can be a fiber or fabric, for example a film of polymer fibers, plate or cloth, and they can support granules on one or both surfaces. The polymer sheet can already contain or support particles of the conductor, as described in example 7, located on the simultaneous consideration of the application. The canvas may contain or may be covered with glue pellets.

In another method of obtaining such a composite precursor granules (as described above) may be located on the surface or surfaces bearing polymer is not subjected to cross-linking, and can firmly be attached to the supporting polymer with cross-linking. While on the raw polymer forms a layer of pressure-sensitive, or electromagnetic shielding layer.

In the third type of composite granules associated with three-dimensional matrix. The matrix can be elektronoprovodyaschie, but may consist of, for example, from a polymer containing ke or in previously published documents. There are several variants of this type of composite, for example: (1) added to the granules, separate conductive or non-conductive or mixed; (2) the matrix material different from the polymer granules degree of cross-linkage; (3) the matrix material may enter the space between the granules, or may only support the bag.

In the specific example of the third type polymer composition may be in bulk form, as described in located on the simultaneous consideration of the application, or preferably may be introduced in granular form as follows.

In a composite structure for generating, detecting and transmitting electrical signals internal connectivity is provided in the form of integrated electrically conductive element, such as a layer, such as a metal film or a painting, especially a fully metallized fabric, usually on the basis of a complex of the polyester. Fabric increases tactile sensitivity (increase in the incidence of resistance relative to the load by weight) of conductive polymer compositions by providing a hard fibrous anvils for elastomeric bias and provides an electronic bridge between zonama or formed on the conductive element.

Despite the fact that the composite can be a simple device for switching its deformation can be created more complex circuits on a layer, for example, metallic fabrics. Coated metal fabric is usually produced by applying a metal woven polyester fabric by vapour deposition, sputtering or similar ways.

Circuits similar to the circuits etched on a conventional printed circuit, can be created by applying a temporary protective coating and etching pre-metallized fabric or preferably by applying a temporary protective coating on the target tissue at the stage of metallization.

In the last example, the metallic coating is only where it allows the protective coating, and using this method can be obtained by conducting a contour map.

Composites, including contour fabric, showing the true flexibility, are in the solid state and can be made maximally sensitive to touch or to other work efforts. They can be used for keyboard or similar switching and regulation can control the load politically electric current.

Whatever type of composite was not considered particularly useful composite contains granules and includes means for introducing electrical and/or mechanical deformation to activate it. Therefore, the fabric or matrix must contain ohmic(s) conductor(s), electrically connecting together of the granules.

Granules can also be used as a component of other conductive and electromagnetic shielding materials or separately, or in combination with other powders or granules or other non-conductive, semi-conductive or conductive materials.

Coated granules surface can be particularly sensitive to applied pressure with increasing pressure sensitivity with increasing surface loading. The granules are essentially covered with granules surface can exhibit a decrease of electrical resistance of more than 1012Ohms when the applied force in the range from 0.01 to 6 N/cm2.

Regardless of the type manufactured composite, it preferably contains gidrofobiziruyuschey agent, as described above, which is present during the formation of the aggregate granules.

The composites containing granules in the form of a film or devicelost and linearity of the resistance changes than can be obtained in the case of large pressure-sensitive polymer compositions in accordance with the simultaneous consideration of the application. Similar bulk compositions granules are returned to the state characterized by the resistance of peace, when removing the load.

For granules and/or matrices (especially conductive) suitable polymeric component is an elastomer, in particular having the following General properties: 1) low surface energy, usually in the range of 15 to 50 Dyne/cm, but preferably in the range of 22-30 Dyne/cm;
2) surface energy wetting for the cured elastomer is higher than its uncured liquid;
3) low rotational energy (close to zero), which ensures a very high elasticity;
4) high stickiness when pressing as filler particles, and electrical contacts to which the composite can be attached, i.e. has a high ratio of viscous to elastic properties at intervals comparable to the binding time (seconds);
5) good triboelectric properties on the system as a carrier of positive charge (or, conversely, will not bear a negative charge on their surface);

The elastomer may be a mixture containing cured elastomers selected from the group comprising one, two or more silicone component, one, two or more polygermanes connection and polyphosphazene and at least one silicone agent. In such polymer mixtures of the silicone component is in excess relative to other polymer components.

Other auxiliary additives are included in the case for modification of physical and/or electrical properties of the uncured or utverzhdenii polymeric composition. Such additives may include at least one suitable modifier from the group comprising: alkyl - and hydroxyethylcellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropylcellulose, polyacrylamide, polyethylene glycol, poly(ethylene oxide), polyvinyl alcohol, polyvinylpyrrolidone, starch and its modifications, calcium carbonate, colloidal silica, silica gel and analogues of the strength of silicon dioxide is an example of a modifier, which is commonly used in elastomer technology. In the present invention when the ratio between 0.01-20 wt.% based on the final composition, it acts as a filler, reinforcing the recovery after deformation, i.e. it increases the elastic deformation of the polymeric composition to accelerate the return of a composition in a state of rest after removing any effort. Preferred silicone system is made of high-strength cured at room temperature (RTV) silicone polymer filled with colloidal silicon dioxide. In another example, use cured at high temperature (HTV) silicone content of colloidal silicon dioxide to obtain a structure for implementation, useful strength, stickiness when pressing and durability and crosslinked at elevated temperature in the presence of peroxide or other catalyst, which is typically, but not exclusively, can be a 2,4-dichloro-Dibenzoyl peroxide. Such cured at high temperatures, the products can be stored for a long period in the uncured state until processing in the canvas, a piece of foam, fiber, extruded shape or other shape is ogorodnya rubbers. Especially for matrix material such a rubber may be introduced in the form of a latex.

The resulting composites can exhibit the effect of the charge due to the piezoelectric effect, and will change their internal electrical resistance in response to both the pressure (pressure), and deforming efforts. The working resistance is approximately in the range from 1012up to 10-1Ohms, and the composite has excellent conductive capacity; usually the composite sample thickness of 2 mm on the heat sink can control AC or DC current of 3 A/cm2. The initial application of pressure or force to the composite sample with high resistance leads to the generation of electrostatic charge; increasing the pressure or force lowers the electrical resistance of the composite. Composites can be resilient and can recover after removal of the pressure or force. Once this happens, the electrical resistance will increase to values at rest, and will arise a certain electrostatic charge. Electrostatic effect can provide a digital indication of the switch or to create a voltage source. The change in electrical resistance is t to be used to provide digital switching, in particular, but not necessarily, the upper and lower boundaries of the interval. Sensitive variants of the composite, which is close to the conductivity can be converted to a fully conductive state by application of an electrostatic charge, which is usually generated by a piezoelectric spark generator and is more than 0.5 kV.

The composite may consist of granules held within the matrix. Inside the granules are conducting particles in this size distribution to obtain a dense Packed structure with the filling of the intermediate particles. The voids present in the amount of powder guide, filled with elastomer during mixing, and the particles of the conductor are located in close proximity in the curing process. To obtain such a structural configuration, the elastomer should have a low surface energy relative to the powder phase and surface energy uncured liquid is less than the surface energy of the cured elastomer. Such polymeric compositions will contain silicones, polygermanes connection and polyphosphazene. In the deformed state is distorted, so that the average distance between to the, for other types of particles may have other effects (change of ferromagnetism, piezoelectricity, ionic conductivity, and others).

For compositions filled with metal, the transition from the undeformed to the deformed state of the bulk conductivity will change the conductivity of the elastomer to the conductivity of the trapped particles of the conductor. At some level of distortion, the number of tracks open circuit from particle to particle provides the conductivity close to the conductivity, defined as the specific volume resistance of the metal. Because of this effect, ultimately, is associated with distortion of the volume of the composite and as bulk material is highly elastic and, therefore, absorbing energy, low metallic conductivity can be achieved only for thin sections (less than 2 mm in the horizontal dimension) of the composite material or the application of a large external deformation or strain, or torque. When removing the external force, the material returns to its original structure, and the captured particles are held separately within the elastic insulating structure.

Unexpected is that the set of granules of prami 2 x 2 cm in a compressed state. This unique property can be explained by the fact that in the compressed state, the conductivity is mainly implemented through the metal bridges described above. So, to explain the conductivity of the material is best described in terms of a heterogeneous mixture, in which an insulating sealant dominates in determining the electrical properties at rest; and committed to the electrical properties of conductive bridges (with local resistivity seeking specific resistance of the conductor is typically 1-1000 µohm-cm) in a compressed state (usually having a specific resistance more than 1 mω-cm). Electronic conductivity is also limited conductive filler due to the inability of sealant to keep the negative electronic charge (usually sealant is a medium optimum positive triboelectric charge). For a fixed composition, the statistical probability of formation of a bridge directly related to the thickness of the composite. Therefore, as a sensitivity to the distortion, and the ability to transfer current increases with decreasing thickness and the smallest thickness of the films is limited by the distribution of filler in size. D0-40 microns.

By introducing particles of zirconium (or other ion conducting materials) in the silicone elastomer, granules and/or between the granules may be made of a composite material, which provides both the conduction electrons and in the presence of gaseous oxygen ions of oxygen. By regulating the deformation of the bulk material (for example, by introducing a bulk composition is static or externally tuned on resonance "deformation grids) conduction electrons and oxygen can be implemented so that it takes place in different planes or in different parts of the volumetric structure. Such properties may be of particular interest in creating systems of fuel cells. It was also established that the internal ohmic heating can affect the internal structure of the composite. For example, for compositions containing Nickel as a conductive filler, cured at room temperature silicone sealant and as a skeletal modifier colloidal silicon dioxide, found that differential expansion of the sealant relative to the conductor occurs in this ratio (usually sealant expands up to 40 times faster than providersite changes the strain/stress in dependence of the transition resistance. This effect may be caused at low differential temperatures (usually less than 100oC). This effect (causing positive temperature coefficient of resistance (phase transition) in the phase of the composite) can conveniently be used to control the electric current. The beginning of phase transition can be adjusted by raising or lowering the mechanical pressure of the polymer composition. On the other hand, composites, which have a low electrical resistance (typically <100 Ohms) at rest, ohmic heating is switched due to the effect of phase transition between conducting and insulating States of the composition, which is under a small compressive force, or without it. This effect enables the use of these polymeric composition as switches or fuses, which abruptly become the state with high resistance in response to excessive current flow and which, because of their elastomeric nature will be returned to the conducting state without removing power when the current returns to the set value. This effect of phase transition can also be used in self-regulating heating elements, where the levels of heat m the e point of phase transition at the required temperature. The polymer composition will maintain a relatively stable temperature due to cyclic transition in phase and out of phase transition. The composition has a wide temperature tolerance and good thermal conductivity.

The Nickel powder used in the invention, is an INCO Type 287, which has the following properties: beads with the cross-section average of 2.5-3.5 µm; length of chain may be more than 15-20 microns. It is a fibrous powder with a three-dimensional capodanno spatial structure of the bulbs with the pointed protrusions, having a considerable surface area. In accordance with this structure bulk density of 0.75-0.95 g/cm2.

The size of all particles essentially are below 100 microns, preferably at least 75% weight/weight is in the range from 4.7 to 53 microns.

In a particular example, the distribution of particle size (in microns and weight) as follows (rounded%): 2,4 - 3%, 3,4 - 5%, 4,7 - 7%, 6,7 - 10%, 9,4 - 11%, 13,5 - 12%, 19 - 15%, 26,5 - 15%, 37,5 - 11%, 53 - 8%, 75-4%, 107 - less than 1%.

Other powders of Nickel, obtained using carbonyl way and are applicable in the invention are:
Type 123: bulk density of 1.6-2.6 g/cm2; equiaxial shape; the 0.5 g/cm2; fibrous powder with an average particle size of 0.5-1.0 μm.

Type 255: bulk density of 0.5-0.65 g/cm2; fibrous powder with a three-dimensional capodanno spatial structure of the balls with a very sharp protrusions with a cross-section of 2-3 microns;
chain length 20-25 microns;
91% is less than 100 microns.

The above data quoted in the trade literature INCO Speciality Powder Products London GB - SW1H OXB.

Usually the particles of the conductor have a bulk density less than one third of their density in the solid state.

The composition can be successfully used in combination with the anode or cathode design electrochemical cell based on lithium, manganese, Nickel, cobalt, zinc, mercury, silver, or other chemical battery, including organic. Either or both electrodes may be received by the exchange or coating of the polymer composition to obtain the following advantages:
(1) the element could include its integral (built-in) pressure switch, which, for example, could work due to the pressure normally used to hold the element in place in the battery cell. Using this tool, the self-discharge or short-circuit element could be reduced to that one my switch could simplify the design of the circuit and to provide new applications by eliminating the need for external switches;
(3) as the polymer composition can be made without metal, you can create a fully plastic electrochemical element.

Polymer composition, pressure-sensitive, can also be used without the direct intervention in the chemistry of the element, by placing the composition on the outer shells or areagirls surfaces of the electrodes. Switching polymeric composition can be initiated by externally applied mechanical pressure, for example by pressing with a finger or by spring pressure inside the battery cell. As a result you can get the switch to control external circuits, including circuits battery test.

Other examples of applications of the composition are:
Mechanical transducers both relative and absolute for measuring pressure, load, displacement, torque, elongation, changes in mass and volume, acceleration, flow, vibration, and other mechanical caused changes.

Current sensors.

The sensors of electric and magnetic fields.

The sensors of thermal energy.

Magnetostrictive devices.

Galvanomagnetic devices.

The magnetic resonance device.

Obnarujennaya sound waves.

The relay contacts and transitions.

Electrical conductors and inductors for microcomponents.

Temperature control.

The shielding of the electric and magnetic waves.

Device for protection against voltage and current.

Switch.

Power regulation.

A brief description of the drawing
In the drawing, options a and b, presents graphs showing the change of impedance versus applied pressure for pellets in accordance with the present invention.

Detailed description of the invention
Example 1
Pellets were made from the following components:
INCO Nickel powder 287 - 28
RTV silicone type 2000, ALFAS Industries - 4
[This ratio corresponds to the approximate volume ratio of Nickel: polymer 70:1 based on bulk volume occupied Nickel:the amount of silicone without voids].

The silicone in the form of a soft lump was placed on the bottom of the drive RETSCH mixer RM100, which has a steel mortar and porcelain rotating pestle. The Nickel powder was placed around the lump of silicone. The pestle was lowered, handling manual, about the gap from the walls mortar 1 mm, this product mixture is subjected to a rotational ablation. Approximately 5 min the silicone covering is, weight/weight in microns:
+ 152 - 32
152-75 - 33
75-45 - 32
- 45 - Less than 3
About the end of the granule formation testified changing colors and patterns of the mixture. In the process of mixing due to the reaction of the crosslinking silicone noted the smell of acetic acid; optionally, the mixture can be continued, but it was stopped when it was formed granules or immediately after their formation, to avoid damage of Nickel particles in the granules under the action of shearing forces.

The granules are non-conducting in the quiescent state, but are very sensitive to applied pressure.

Example 2
Repeat the procedure according to example 1 using the following components:
RTV silicone type 1000, ALFAS Industries - 6
INCO Nickel powder 287 - 30
which corresponds to the approximate volume ratio of Nickel:the polymer is 50: 1. Although this ratio is lower than in example 1, the characteristic shrinkage variety of cross-linked silicone led to the granules, conducting electricity without applied pressure. Shrinkage, apparently, was the result of loss of volatile components during the stitching. ALFAS 1000 contains 12% volatile matter. ('ALFAS 2000 contains 4% volatiles).

These granules are of value, for example, is based on the granules:
The test conductor is produced by loading a sample of the granules obtained in example 1, the test element consisting of a strip of silicone rubber sponge with a diameter of 12 mm, thickness 3 mm with a hole diameter of 6 mm, based on a conductive surface that is used as the bottom electrode. The top strip was placed a conductive plate for receiving the upper electrode. The electrodes were United through the constant current source 10 and a buffer amplifier with high impedance 20 Mω to the signal processor Picoscope ADC 100 and the recording device. To measure the amount of effort applied to the subject an item, it was placed on a table device for determining the load Lloyd Instruments LRX, equipped with a countably decisive instrument to the maximum force of 100 N. The item was made slowly increasing the pressure and resistance were recorded and represented graphically by a signal processor. Experiments were performed at two values of the current ( see drawing options a and b):
a - 10 mA (resistance in ohms102and
b - 1 µa (resistance in ohms106).

Load and resistance plotted on the graph is ALOS and caused the change in the potential difference at the element.

Example 4
Nonohmic conductivity:
the subject element of the dreamer 3 was compressed using a static load of approximately 3 H, through the element passed a current of 10 μa; its resistance, calculated from the potential difference of the item was 100 kω. Keep the tension and the applied pressure constant, increased the current to 100 µa. Measured in this case, the potential difference was shown that the resistance of the element is decreased to 50 ohms.

Example 5
Repeated dreamer 1, but with the difference that it used the following source materials:
INCO Nickel powder 287 - 30
HTV silicone (20 Shore, Dow Corning) - 6
The oil below the 50oWith (light fuel oil) - 2
2,4-Dichlorobenzophenone, mg - 200
Pellets were formed in approximately 5 min, during which the oil had evaporated, and there was reasonable (but incomplete) cross-linked silicone. The pellets were subjected to full-linking by heating at 120oC for 20 min and then tested in accordance with examples 3 and 4.

Example 6
Repeating example 1, but with the difference that before adding to the mixer Nickel powder was sprayed aerosol gidrofobiziruyuschih agent WD40 (RTM). The pellets were tested in accordance with examples 3 and 4. Installed, cvii with example 1, preparing the following composition, g:
Fraction of 45-75 μm - 0,225
Fraction 75-152 μm - 0,225
25% in water chloride of hexadecyltrimethylammonium - 0,1
Natural rubber latex (60% weight/weight) - 0,12
Water - 0,15
All the ingredients, except latex, mixed with the formation of the paste. Added latex and optionally mixed with gel formation. The gel was divided into two parts and applied through the stencil to:
(a) copper-plated polyimide printed circuit, and
(b) Nickel-plated printed circuit from polyester.

The resulting structure was dried at 80-90oC for 30 min or dry.

Similar results were obtained when using instead of the chloride of hexadecyltrimethylammonium of dodecylbenzensulfonate.


Claims

1. Composite electrical conductor containing granules, each of which contains one or more electrically non-conductive polymers and particles of one or more electrically conductive fillers selected from metals, metal alloys and oxides of these metals and alloys, characterized in that the particles of the electrically conductive filler are dendritic, fibrous or pointed structure, receiving mechanical deformation or electrostatic charge.

2. The composite under item 1, characterized in that the granules are associated with the supporting material, which limits the peripheral movement of the granules, but can enter into granules electrostatic charge or mechanical stress.

3. The composite under item 1 or 2, characterized in that the granules are mixed with other volumetric or foamed polymers or put on them with the formation of solid, semi-stretch or elastic structures.

4. The composite under item 1, characterized in that the granules are extruded or pressed in the form of paintings, tablets or fiber, or molded in a mold.

5. The composite under item 2, characterized in that the support material is a fiber, foil, leaf, plate or cloth and supports granules on one or both surfaces.

6. The composite according to any one of paragraphs.1-5, characterized in that in order to ensure coupling with an external circuit, it contains an integrated electrically conductive element, such as a metal film or fabric, in particular a continuous metallized fabric.

7. The composite according to any one of paragraphs.1-6, characterized in that the electrically conductive polymer in said pellets is stitched polymer, with granules connected with stitched polymer sewn together.

8. The composite under item 2, characterized in that the support material is a three-dimensional matrix.

9. The composite under item 2, characterized in that the support material is elastomeric.

10. The composite under item 9, characterized in that the elastomeric supporting material is a silicone rubber or a hydrocarbon rubber.

11. The composite according to any one of paragraphs.1-10, characterized in that it is the product of the mixing of these granules with the elastomer in the form of a latex.

12. The composite according to any one of paragraphs.1-11, characterized in that the granules are a product of mixing of the particles of the electrically conductive filler with a liquid form of the polymer in the formation of granules with low shift effort, resulting in particles of a conductive filler remain essentially structurally intact.

13. The composite under item 12, wherein the blending is conducted in the presence of a volatile liquid.

14. The composite under item 12 or 13, wherein the blending is conducted in the presence of the lubricant that reduces friction on the surfaces of the mixer.

15. The composite according to any one of paragraphs.12-14, characterized in that such mixing and the formation of granules was accompanied by p is asrav mixture into granules was synchronized with the cross-linking of the polymer, sufficient to achieve a non-sticky state.

16. The composite according to any one of paragraphs.12-15, characterized in that the polymer component of the composite is subjected to shrinkage in the process of mixing with the conductive filler.

17. The composite according to any one of paragraphs.1-16, characterized in that the volume ratio of the conductive filler: polymer is at least 3:1.

18. The composite according to any one of paragraphs.1-17, characterized in that the filler contains Nickel metal derived from carbonyl compounds.

19. The composite according to any one of paragraphs.1-18, characterized in that the polymer composition is elastically deformable from a rest state and contains at least one electrically conductive filler dispersed in non-conductive elastomer and an encapsulated non-conductive elastomer, and the nature and composition of the filler is such that the electrical resistivity of the composition changes in response to deforming forces in the direction of decreasing up to a value essentially equal to the specific resistance of the conductive jumpers filler, the composition further comprises a modifier, which accelerates the elastic return of the composition in its state of rest after satyamev based on agglomerated and the individual particles of the conductive filler, covered elastomeric capsule, and are the product of granulating a mixture of a conductive filler with RTV-silicone by using a rotational ablation of the surface of the polymer in the polymerization process.

21. The composite according to any one of paragraphs.1-20, characterized in that initially it is in a conducting state and provides the effect of positive temperature coefficient of resistance by switching to an insulating state in response to thermal expansion due to excess current.

22. The composite according to p. 21, characterized in that initially brought into a conductive state due to the shrinkage of the polymer during the preparation of granules.

 

Same patents:

The invention relates to electronic devices and can be used in particular for the manufacture of positron

The invention relates to the field of radio electronics and can be used in the development and industrial production thermoresistive elements of high power with a positive temperature coefficient of resistance

The invention relates to electronic devices and can be used for the manufacture of thermistors with a positive coefficient of resistance (phase transition) position

The invention relates to semiconductor technology and can be used in devices for measuring temperature, flow rates, velocities, composition of gases and liquids

Posistor // 2043670
The invention relates to electrical engineering, and more specifically to the thermistors with positive temperature coefficient of resistance psistorm

The invention relates to the resistive device to control the rotation speed of the fan motor used in an air conditioning system installed, for example, in the car

The invention relates to the resistive device to control the rotation speed of the fan motor used in an air conditioning system installed, for example, in the car

Capacitor // 2012934

FIELD: electronic engineering including thin-film microelectronics.

SUBSTANCE: proposed method includes evaporation of resistive layers on flexible insulating substrate and formation of strain-sensing elements of resistive-strain sensor using photolithography method, their resistance being measured in the course of adjusting temperature-compensated resistance of resistive-strain sensor by means of ohmmeter connected to respective contact pads. Resistive-strain sensor is manufactured from two resistive materials differing in value and sign of temperature-compensated resistance; two series-connected strain-sensing elements are formed on substrate, their integrated leads are connected to contact pad disposed on one end of substrate, and two remaining leads are connected to contact pads disposed in immediate proximity on other end of substrate; temperature compensation is effected by laser adjustment of resistance ratios of sensing elements having previously determined method for electrical connection of different strain-sensing elements. After that contact pads disposed in immediate proximity are connected by resistance welding or soldering for their parallel connection and use is made of two leads connected to contact pads disposed close to substrate on one end as resistive-strain sensor leads for their series connection.

EFFECT: enhanced precision of temperature compensation; facilitated manufacture Of temperature-compensated resistive-strain sensor.

1 cl, 1 dwg

FIELD: thermometry; low-temperature measurements.

SUBSTANCE: sensing element of resistance thermometer designed for measuring low temperatures is made of easy-to-machine alloy of nickel and manganese taken in definite mass proportions.

EFFECT: small size of sensing element, enlarged low-temperature measurement range.

1 cl, 2 dwg

Analytic device // 2289173

FIELD: analytic devices such as sensors for detecting and measuring quantity of materials in fluid state.

SUBSTANCE: sensor responding to chemical or biological material, particle, or radiation has polymeric composition body of first level of electric conductivity in quiescent state and can be transferred to second state of other level of electric conductivity due to variations in mechanical stress applied to body by means of extension or compression, or by means of electric field; it also has electrodes connected to mentioned body for connection to electric circuit responding to variations in mentioned body conductivity. Sensor has channel component for organizing channel therein to pass fluid medium under test. Mentioned body is permeable for mentioned fluid medium and stretches crosswise of channel so that fluid medium flows through mentioned body. The latter is made in the form of layer of granules which is supported within channel between two electrode-forming perforated lattices. Body can be made in the form of sheet incorporating foam or textile with granules of mentioned polymeric composition dispersed therein.

EFFECT: ability of sensor to afford static and dynamic contact and of real-time system variation.

9 cl, 32 dwg

FIELD: electricity.

SUBSTANCE: film planar voltage variable capacitor comprises a dielectric substrate, on the surface of which there is a layer of a ferroelectric material, working electrodes and contact sites arranged on the basis of the multi-layer metal structures from sputtered and galvanically grown layers of metals, the working electrodes of the voltage variable capacitor are made in the sputtered layer of aluminium applied onto the layer of the ferroelectric material.

EFFECT: improved durable stability of voltage variable capacitors.

6 dwg, 1 tbl

FIELD: physics.

SUBSTANCE: invention relates to positive temperature coefficient (PTC) devices, having a PTC element, particularly a polymer PTC element and an electrical device having said PTC device. The PTC device (10) has a multilayer base (14) which operates as a heat-conducting medium and a polymer PTC element (12) situated on the base, wherein the polymer PTC element is situated on one surface (15) of the multilayer base (in a thermally coupled state) and the polymer PTC element and the multilayer base are brazed into a resin such that the other surface (15') of the multilayer base remains outside.

EFFECT: fast detection and prevention of heating up of the substrate to an extremely high temperature.

11 cl, 7 dwg

FIELD: monomolecular electronic devices.

SUBSTANCE: proposed monomolecular electronic device has plurality of monomolecular conductors chemically bonded with at least one insulating group. At least one of mentioned molecular conductors is chemically bonded with doping substituent to form inherent bias across ends of mentioned insulating group. Second insulating group is chemically bonded with mentioned molecular conductor and current conducting complex is chemically bonded with mentioned second insulating group to generate separate molecule. Various alternatives of monomolecular electronic devices, monomolecular transistors, and monomolecular logic inverters are proposed.

EFFECT: developing of monomolecular switching device displaying power gain.

36 cl, 12 dwg

FIELD: microtechnology; manufacture of microchip electrode systems for microanalytical devices.

SUBSTANCE: proposed conducting composite incorporates elastomer, conducting polymer, and conducting carbon filler in the form of polymethyl methacrylate. Proportion of components is as follows, mass percent: conducting carbon filler, 95-97; elastomer, 1-2; polymethyl methacrylate, the rest. It is most reasonable to use glass-reinforced carbon or granular graphite as conducting carbon filler and polydimethyl siloxane, as elastomer. To facilitate its use conducting composite may be transformed to suspension in volatile concentrated solution or hexane or cyclohexane in dichloroethane. Resistivity of dried composite is 0.05 - 0.14 Ohm-cm.

EFFECT: facilitated preparation and use, enhanced chemical and biological inertness of composite.

5 cl, 1 dwg, 1 tbl

FIELD: semiconductor engineering; biology, ecology, and medicine.

SUBSTANCE: proposed electric-wave oscillator producing relaxation oscillations whose frequencies can be varied within wide range without changing supply voltage or current has its semiconductor structure built around liquid solutions of p and n organic materials with needle electrodes immersed in n-type liquid organic semiconductor and electrode immersed in p-type semiconductor. Liquid p semiconductor may be 1-20% aqueous solution of fuchsin triphenyl methane die or aqueous solution of methylene blue organic die of 1-20% concentration, or aqueous solution of glucose of 1-50% concentration. Aniline can be used as n-type liquid semiconductor.

EFFECT: ability of producing relaxation oscillations close in their parameters to those noted in biological objects.

5 cl 1 dwg, 3 tbl

FIELD: liquid semiconductors for biology, ecology, and medicine.

SUBSTANCE: proposed method for generating electric oscillations at frequencies close to those noted in biological specimens includes passage of electric current between electrodes immersed in n-type liquid organic semiconductor and placed at potential difference of 5-70 V. Current of 1 to 500 μA is passed between electrode placed at positive potential and that immersed in p-type liquid semiconductor.

EFFECT: ability of generating electric oscillations at frequencies close to those noted in biological specimens.

5 cl, 1 dwg

FIELD: photodiodes responding to ultraviolet spectrum region.

SUBSTANCE: proposed ultraviolet photodetector characterized in reduced sensitivity in visible region of spectrum has transparent hole-injection layer that functions as anode applied to solid transparent substrate, organic semiconductor layer, and electron-injection metal layer that functions as cathode. Organic semiconductor layer has active photosensitive layer of 3-(4-biphenyl)-(4-tertiary-butyl phenyl)-(4-dimethyl amino phenyl)-1,2,4-triazole (DA-BuTAZ) that abuts against cathode and organic hole-conducting layer that abuts against anode.

EFFECT: maximized photosensitivity in ultraviolet spectrum region at reduced sensitivity in visible region.

3 cl, 2 dwg

FIELD: physics.

SUBSTANCE: invention relates to the method of generating electric oscillations using semiconductor and liquid dielectrics, and can be used biology, ecology, medicine and other fields, related to biological objects. The method involves exposure of a liquid medium, placed between two electrodes to an electric field. The liquid medium used is in form of protein solutions, based on substances with hydrogen bonds, extracted from biological objects and containing nano- and microclusters. The protein solutions are exposed to an alternating electric field with intensity 10-100 V/m and frequency 1-90 Hz. The protein solutions used are aqueous or aqueous-alcohol solutions.

EFFECT: design of an efficient and non-toxic method of generating electric oscillations of a wide frequency range, imitating oscillations of biological objects, which allows for simulating biophysical and biochemical processes in them.

2 cl, 1 dwg,1 tbl, 2 ex

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