1. A waterborne conductive composition comprising
(i) metal flakes or particles;
(ii) an alkali-soluble acrylic or methacrylic acid copolymer in an effective solvating amount of water and alkali to dissolve the (meth)acrylic acid copolymer;
(iii) a water-insoluble polymer dispersed in water; and
(iv) optionally, a coalescing agent, a plasticizer, or both.
2. The composition according to claim 1 in which the alkali-soluble (meth)acrylic acid copolymer is styrene-acrylic acid copolymer.
3. The composition according to claim 1 in which the water-insoluble polymer dispersed in water is selected from the group of polymers consisting of polyurethane, acrylic, polyester, and vinyl.
4. The composition according to claim 3 in which the water-insoluble polymer dispersed in water is poly(vinyl chloride).
5. The composition according to claim 1 in which the metal flakes or particles are selected from the group consisting of silver, copper, nickel, silver coated materials, copper coated materials, nickel coated materials, and mixtures thereof.
6. The composition according to claim 4 in which the metal flakes or particles are bimodal flakes coated with oleic acid.
7. The composition according to claim 5 in which the bimodal metal flakes are silver and have a mean mass diameter (D50) of 3 \u03bcm.
8. The composition according to claim 4 in which the bimodal metal flakes are silver and have a 90% diameter (D90) of 8.8 \u03bcm.
9. The composition according to claim 4 in which the ratio of metal flakes or particles to the remaining solids content of the composition ranges from about 8 to about 10.
10. The composition according to claim 1 in which the coalescing agent is present and is selected from the group consisting of ethylene glycol monobutyl ether, 1,3 butylene glycol; propylene glycol, and ethylene glycol.
11. The composition according to claim 1 in which the plasticizer is present and is selected from the group consisting of dipropyleneglycol dibenzoate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, di-iso-octyl phthalate, dinonyl phthalate, a mixture of C7-9 dialkyl phthalates, ditridecyl phthalate, butyl benzyl phthalate, dibutyl adipate, dihexyl adipate, dioctyl adipate, di-iso-octyl adipate, dibutyl sebacate and dioctyl sebacate.
12. The composition according to claim 1 in which the water insoluble polymer is dispersed in water and is a copolymer comprising styrene and 2-ethylhexyl acrylate monomers.
13. A conductive coating disposed on a flexible substrate formed by printing and drying the composition according to claim 1.
14. An RFID antenna comprising the conductive coating according to claim 12.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. Device for scanning a yarn that is moved in its longitudinal direction in a measuring gap with a light beam from a light source, comprising a receiver for light reflected at the yarn, a unit for processing electrical signals from the receiver, and a single light source for emitting light in at least two wavelength regions, the wavelength regions being determined by two main wavelengths, said unit for processing electrical signals from the receiver including a computer which forms a vector from the values for each of the at least two specified wavelength regions and forms a sum vector from the vectors.
2. Device according to claim 1, wherein the main wavelengths determine two colours in the region of wavelengths of visible light.
3. Device according to claim 2, wherein the main wavelengths relate to the colours red, green and blue.
4. Device according to claim 1, wherein the single light source is in the form of a light-emitting diode which is able separately to emit visible light in three colours in the visible range.
5. Device according to claim 1, wherein the single light source and a receiver have principal axes for the emission and reception of light which together span a plane that is transverse to the longitudinal direction of the yarn.
6. Device according to claim 1, wherein for the end point of the sum vector in a space a region is delimited which indicates whether the electrical signal from the receiver processed to form the sum vector indicates a foreign body in the yarn.
7. Device according to claim 6, wherein the space forms a cube which is formed by axes along which values for the intensity of three main wavelengths are plotted.