GB2493492A

GB2493492A - A building material comprising a conductive polymer core and an outer metallic layer

Info

Publication number: GB2493492A
Application number: GB1110808.1A
Authority: GB
Inventors: Mark Stephen Jones
Original assignee: KARM CONDUCTIVES GROUP Ltd
Current assignee: KARM CONDUCTIVES GROUP Ltd
Priority date: 2011-06-27
Filing date: 2011-06-27
Publication date: 2013-02-13
Also published as: EP2723953A1; WO2013001286A1; AU2012277587A1; GB201110808D0; US20140329045A1

Abstract

A building material 1 comprising: a conductive polymer core 3 and an outer metallic layer 2. The outer metallic layer 2 may completely surround the core, or partially surround the core. A method of making a building material is also provided where the building material comprises a conductive polymer core and an outer metallic layer, and said method comprises forming a core comprising a conductive polymer and electroplating the outer layer over the core (figure 3). The core may be used as the cathode in the process. The outer metallic layer can comprise a metal alloy or zinc, copper, nickel, bronze, brass, solder, chrome, lead, tin, gold or silver. The conductive polymer may be made conductive through the addition of conductive particles such as carbon black, graphite carbon nanotubes or metal powder. The building materials may be used for placement on the outside of buildings, such as panels, guttering, tiles or fascia.

Description

Title; Buuqing: mateHals DescrlntiOh of Invention The prep ent invention relatea to building materials. In partit4iiar, the present ltxiepn relates ling flTi$ tot placeMent, on the e4eriar of buildings. The present lhvention San relates to meth ds of producing such bUikiin9 snatettais.

Mg,,e, building methods caD bra Vadettof building r,,tetiaiS tQJnter ails suit aestheSpreferenc.and provideweatber resistance over a: numt:ofyears.

Vatious different materials have been used in the past tp pro dde desired finishes to buildings. Common building materials inclqde bric4cs and mortar for ssIls an4 slates for rOofs Metá1Ii panels for exterior walls aS/br tiles for roofS are: quite re9ulwly used to provids hard wearing buddng Materials whráh can: come in a variety of olba Pans and dies can be provided With niatdiiñg fta&1ngs and anciffalies.: to provide a desired flnish. Examples of metallib panels are provided in the UK by Kingspan Bend ark and by j(M' in addition, RókWoóI174 sell imitation metallic panelt Vulcan Supply iirpJM sell tooling pSuctL e.g. roof flies, wl4jbh oOrrsist of copper. the topper Is said to provide aesthetic propetties to roofs, be waterptoof and be environmentally ftkdiy.

AIthough.knon1!e*alIio building materials, S4. those rStidned abtand UP. *0. stroflg: wather çQ7T$qps, they use a large amount of rnsrt täw niatedai. This results in high: raw rn:aterial cost, when: compared to, for examplo, ceramic tiles, and general high densIty, leading to higher transport 3G cS, Win, compared to, for exienpl ceranic tiles. The iflciusiøn of large amounts of metal: raw rn Ø'W means that metallit building rnate4ali are heavy thr theit size, relath'e to piasttc pacs for example, because metais generally have a high density. Heavier panels for roofing, for exarnpl, place limits on design freedom in buildings, increases transportation costs and places tough limits on structures, e.g. with a particularly heavy roof walls would have to be thicker and foundations built to be more robust.

It would, therefore, be preferable to have building materials which provide the aesthetic and weather resistant properties of known metallic bLulding matenals whilst using less metal.

According to a first aspect of the present invention, there is provided a building material, comprising: a core comprising a conductive polymer, and, an outer layer, wherein the outer layer is metallic.

Preferably, wherein the outer layer surrounds the core.

Further preferably, wherein the outer layer partially surrounds the core.

Advantageously, wherein the conductive polymer comprises an electrically conductive thermoplastic, a conductive thermoset plastic a conductive elastomer, and/era conductive polymer blehd.

Preferably, wherein the core comprising a conductive polymer further comprises a non-conductive material.

Further preferably, wherein the conductive polymer blend is one or more polymers filled and/or mixed with conductive particles.

Advantageously, wherein the conductive particles are one or more of carbon black, graphite, carbon nanotubes and metal powders.

Preferably, wherein the outer layer is zinc, copper. nickel, bronze, brass., solder. chrome, tin, lead, gold, silver and any other metallic metal or alloy, or combination of metallic metal and/or aHoy, preferably, wherein the pjter layer is copper.

Further preferably, wherein the building material is a panel, a façade panel, a rainscreeri, a tile, a door, a fascia a soffit a weatherboard, ,a garage door, door furniture, fencing, a building detailing, a flashing., guttering, piping, a window.frame or an ancillary of any shape and/or size for a particular building function..

According to a further aspect of the present invention, there is provided a method of making a building material, for use on the exterior ofa building, the building material comprising a core comprising a conductive polymer, and, an outer layer, wherein the outer layer is metallic, wherein the method comprises: forming a core comprisIng a conductive polymer, and electroplating the outer layer over the core.

Preferably, wherein the step of electroplating the outer layer over the core is by electrochernical means.

Further preferably, wherein the conductive polymer is an electrically conductive thermoplastic, a conductive thermoset plastic, a cond Lictive elastorner, or a conductive palymer blend.

Advantageously, wherein the core conipri&n.g a conductive polymer is frrned by a polymer manufacturing processes, preferably, compression moulding, extrusion or injection moulding.

Preferably wherein the step Of forming a core comprising a conductive polymer comprises the step of over moulding the conduotive potymer over another material, optionally wherein the other material is a non-conductive polymer.

Further preferably, further comprising the step of, after forming th core and be±ore electroplating the outer layerover the core, working the core so that it adopts a suitable shape.

Advantageously, wherein electroplating the outer layer over the core by electrochenhical means comprises: placing the. core in a solution of metal ions, the core being configured to act as a cathode, placing an anode comprising metal atoms, the metal atom being for the outer layer, in the solution, and, providing a voltage across the core and the anode so that there is a not movement of metal atoms from the anode to the cathode to form the outer layer.

Preferably, wherein the method comprises the further step of affixing a blocking structure to the core prior to electroplating, so as to prevent formation of an outer layer at one or more postions on the core.

Further preferably, further comprising a washing step at any point.

Advantageously, further comprising a working step after electroplating the core to work the outer layer into a desired shape.

In a further aspect of the present invention, there is provicCd a uildin.g material obtainable by a method according to the above mentioned methods.

Embodiments of the invenlion are described below with reference to the accompanying drawings, in which: Figure 1 is a schematic representation of a building material according to the present invention.

Figure 2 is a ccoss*section alongline A-A of Figure t.

Figure. 3 is a schematic representation of.a method of manufacturing a building material according to the present invention.

Referring to Figure 1, a building material 1 is shown. In the embodiment shown ri Fiqure 1, the building material I is a tile which could be placed on a roof or on an external surface of a building. In other embodiments, the building material item could be a panel (optionally, a façade panel), a rainscreen, a tile, a door. a fascia, a soffit. a weatherboard, a garage door, door furniture, fencing, a building detailing, a flashing, gutteririg, piping a window frame or an anciflary of any shape and/or size foi a particular building function.

Figure 2 shows the building m2terial 1 in cross section along the line A-A.

Figure 2 shows that the building material 1 has a core.3 and an outer layer 2 surrounding the core 3. The core 3 comprises a conductive polyrher, for example an electrically conductive thermoplastic. The. outer layer 2 is a metallic layer.

Examples of bonductive polymers which in.diffetent embodirnent can make up the core 3, either siflgly, in combination or in cwtibination With other materials, include intrinsically conducting polymers (i e organic polymers that conduct electricity), e.g. electrically conductive thermopJastics, conductive thermoset plastics or conductive elastomers; and1 conductive polymer blends, namely, polymers which are not necessarily conducting, filled and/or mixed with conductive particles, where the conductive. particles can optionafly be one or more of carbon black, graphite, carbon nanotubes and melal powders (e.g. products currently available from RTP Company RIP 0195 X 125727 or from Premix Group: PRE-ELECR PP 1380).

In one embodiment, the conductive polymer at the core 3 may be ovei moulded over another polymer or material, which may not he electhcally conductive In this embodiment, the core 3 is formed by initially forming a composite part from a first polymer; e.g. a non-electrically conductive polymer (which may be relatively cheaper and/or lighter than the electrically conductive polymer, e.g.. epoxy resin) and subsequently forming the electrkally condubtivë polymer over the composite pail formed of the first polymeE Examples Of metals and alloys which in different embodiments make up the outer layer 2 include zinc, copper, nickel, bronze, brass, solder, chrome, tin, lead, gold, silver arid any other metallic metal or alloy, or a combination of metifilid metal and/or alloy.

The presence of the core 3 reduces the amount of metal required in the building material item 3, as compared witn building materials made enhrely of metal.

The building material 1 can, in one embodiment, be made by a method as discussed with reference to Figure 3.

Figure 3 shows electroplating of a metallic, outer layer 2 on top of a core 3, the core 3 being made of conductive polymer, e.g. electrically conductive thermoplastic(s) The core 3 of conductive polymer can be made by known polymer manufacturing processes, such as compression moulding, extrLision or injection moulding. Using these known processes, the core 3 can be shaped for its desired function.

In figure 3, the cathode is tte core 3. The anode 4 is a metallic elei-nent made up of metal atoms which are to be layered on top of the core 3, The cathode and the anode 4 are both connected to an external supply of direct current S. e.g. a battery or a rectifier. The anOde 4 is connected to. the positive terminal of the external supply of direct current 5 and the cathode is connected to the negative terminal. When the external supply of direct current 5 is turned on, the metal at theanode is oxidised to form cations which have a positive char9e and go into the solution 6. which has a meniscus 7. The cations M9 associate with anions A in solution. The cations are reduced at the cathode and deposit in the metallic state In oTher words by way of this electroplating process, a metãlhd outer layer 2 forms over the core a.

In the above process, the cathode can be made from any conductive polymer, e.g. electrically conductive thermoplastic. Examples of electrically conductive therrnoplastics include, but are not limited to, Cool Polymers, Inc's series polymers, such as E2 and E5101.

in an alternative embodiment, the core 3 mentioned above can.addiiionally include injection moulding metal powders to make a conductive polymer/thermoplastic and metal matrix Examples of injection moulding metal powders include, but are not limited to, bronze granules (e g type F, as currently sold by AVL Metal Powders NV, Kortrijk Belgium) and flake metal copper powder (e.g. type 2500, as currently sold by AVL Metal Powders NV, Kortrijk, Belgium).

in the above process, the anode can be. made from any metal or alloy, ia. an alloy w. hich can undergo the electroplating process, from which it is desired to form the outer layer 2 over the core & Examples of metals and. alloys which can form the anode include, but are not limited to: zinc, copper, nickel: bronze, brass, solder, chrome, tin, lead, gold, silver and any other metallic meta.l or alloy, or combination of metaiho metal and/or alloy. a

In the above process, the solUtion 6 contatn5 a dissolved mixture of metallic salt which: is complementary to.the metal forming the anode 4. For example, when the anode is copper, the solution 6 can be a solution of CuSO4, so the anion, A. is Sot and the copper ions in solution are Ou2. Another example, when the anode is zinc, the solution 6' can be a solution of ZnSO4, so the anion, A', is SOt and the zinc ions in solution are Another example, when the anode is nickel, the solution 6 can be a solution of NiSO4, so the anion, A, is SOt and the nickel ions in solution are Ni24.

As with known electroplating processes, the anode is often of the same metal to be deposited but not always. The anode can consist of a, non-c: onsumable alternative metal. For example., lead can be used as the anode when it is desired to reduce the gil of copper content in the copper plating solution. In another example, tin-lead alloy anodes ban be employed for chromium, plating, for example With chrome flakes directl9 added according to the usage of the bath as opposed to a reduction of the anode.

Generally, the conductive polymer which makes up. the bore 3 is selebted to.

aflow sufficient electrodeposition of.. the chosen metal or allay. The conductive polymer will have an electrical resistance of 10000 per square or less, nciuding each and every integer below 100011 per square, preferably an electrical resistance of 400 per square or less'. The units, of per square are commonly used when referring to sheet resistance. Referrih to sheet resistance as simply Cl could be taken out of context. and misinterpreted as bulk te'sistan'ce.

In the example shown in Figure 3, only part of the core 3 is shown in the solutionS. ln.a preferred embodiment, the.wh:ole of the core.3 is cc.vered with the metalflc outer layer 2. In other embodiments, only part of the core 3 is covered with the metallic outer layer 2, e.g. only the part of the building material 1 which is tO be exposed to the elerhénts when the build ing material is in use.

An alternative method of covering the core with a metal and/or alloy is by way of electroless plating. EJe.ctroless plating is an auto-catalytic process for depositing a metal and/or aNoy on an Dbject, for example, a plastic object.

Electroless plating ut'lises a reducing agent to react with metal ions in solution to deposit metal on the object.

A further alternative method of covering the core is by direct plating. i.e. taking an object, e g the plastic object making up the core, and pIecing the metal and/or alloy around the core Optionally the metal and/or alloy is attached to the core by way of an adhesive.

The building mterials according. to the present invention provide building materials with similar wear properties to known metallic building materials with at least the advantage that the building materials of the present invention use less raW metallic materiaL This saves on raw material cost and also reduces the weight of the building matehals, thereby reducing, for example, transportation cost.

When used in this.speSlicaticn and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the. following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, sepatately. or in any tbrnbin*i 0! such teat tea. be qtiiied fqr realising the invenjqn in diverse font's the p ft