1. A process for preparing an alkali metal or alkaline earth metal salt of an \u03b1,\u03b2-ethylenically unsaturated carboxylic acid, wherein
a) a transition metal-alkene complex is reacted with CO2 to give a metallalactone,
b) the metallalactone is reacted with a base to give an adduct of the alkali metal or alkaline earth metal salt of the \u03b1,\u03b2-ethylenically unsaturated carboxylic acid with the transition metal complex, the base being selected from alkali metal or alkaline earth metal hydroxides and alkali metal or alkaline earth metal superbases, and
c) the adduct is reacted with an alkene to release the alkali metal or alkaline earth metal salt of the \u03b1,\u03b2-ethylenically unsaturated carboxylic acid and regenerate the transition metal-alkene complex.
2. The process according to claim 1, wherein the alkali metal or alkaline earth metal superbase is selected from alkali metal or alkaline earth metal alkoxides, alkali metal or alkaline earth metal hydrides, alkali metal or alkaline earth metal azides, alkali metal or alkaline earth metal phosphides, alkali metal or alkaline earth metal silanolates, alkali metal or alkaline earth metal alkyls or alkali metal or alkaline earth metal aryls.
3. The process according to claim 1, wherein the transition metal complex comprises at least one metal of group 4, 6, 7, 8, 9 or 10 of the Periodic Table of the Elements.
4. The process according to claim 3, wherein the transition metal complex comprises a complex of Ni.
5. The process according to claim 1, wherein the transition metal complex comprises at least one ligand which comprises at least one phosphorus atom which coordinates to the transition metal andor a carbene group which coordinates to the transition metal.
6. The process according to claim 5, wherein the ligand comprises at least one phosphorus atom which coordinates to the transition metal and at least one radical is bonded to the phosphorus atom via a secondary or tertiary carbon atom.
7. The process according to claim 5, wherein the ligand comprises a bidentate P,P, P,N, P,O or P,carbene ligand.
8. The process according to claim 7, wherein the bidentate P,P, P,N, P,O or P,carbene ligand is coordinated to the transition metal to form a five-membered ring.
9. The process according to claim 8, wherein the ligand comprises 1,2-bis(di-tert-butylphosphino)ethane or bis(di-tert-butylphosphino)methane.
10. The process according to claim 1, wherein the alkene comprises ethene and the \u03b1,\u03b2-ethylenically unsaturated carboxylic acid comprises acrylic acid.
11. The process according to claim 1, wherein the reaction medium comprises a solvent selected from aromatic hydrocarbons, halogenated aromatic hydrocarbons, ethers, alcohols, dimethylformamide, dimethyl sulfoxide, water and mixtures thereof.
12. The process according to claim 1, wherein the alkali metal or alkaline earth metal salt of the \u03b1,\u03b2-ethylenically unsaturated carboxylic acid formed in step c) is removed from the reaction medium.
13. The process according to claim 12, wherein the removal comprises a liquid-liquid phase separation into a first liquid phase in which the salt of the \u03b1,\u03b2-ethylenically unsaturated carboxylic acid is enriched, and a second liquid phase in which the transition metal-alkene complex is enriched.
14. The process according to claim 13, wherein, after step c), the reaction medium is extracted with an aqueous phase and the first liquid phase obtained is an aqueous solution of the alkali metal or alkaline earth metal salt of the \u03b1,\u03b2-ethylenically unsaturated carboxylic acid.
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. A card cleaner assembly for use in an identification card printer comprising:
first and second cleaner pinch rollers adapted to receive a transported card therebetween;
first and second tape rollers supporting a cleaning tape loop, the cleaning tape loop sandwiched between the second cleaner pinch roller and the first tape roller and including debris-collecting exterior surface that engages the second cleaner pinch roller;
a first bracket for supporting the first and second cleaner pinch rollers and the first tape roller;
a second bracket supporting the second tape roller, wherein the first and second brackets are configured in sliding arrangement having a roller release position in which at least one of the first and second cleaner pinch rollers or the first tape roller is removable, and an operating position in which the first and second cleaner pinch rollers are set to clean a transported card; and
a biasing mechanism configured to bias the first and second brackets in the operating position.
2. The card cleaner roller assembly of claim 1, wherein the cleaner pinch rollers are coated with a debris-collecting material.
3. The card cleaner roller assembly of claim 1, wherein the biasing mechanism includes a spring coupled to both the first and second brackets.
4. The card cleaner roller assembly of claim 1, wherein either the first or second bracket includes a channel in which a portion of the other bracket can slide.
5. An identification card printer comprising:
a card supply containing a stack of cards;
a transport mechanism adapted to receive a card from the card supply and transport the card along a print path;
a card cleaner roller assembly including:
first and second cleaner pinch rollers adapted to receive a transported card therebetween;
first and second tape rollers
supporting a cleaning tape loop, the cleaning tape look sandwiched between the second cleaner pinch roller and the first tape roller;
a first bracket for supporting the first and second cleaner pinch rollers and the first tape roller;
a second bracket supporting the second tape roller, wherein the first and second brackets are configured in sliding arrangement having a roller release position in which at least one of the first and second cleaner pinch rollers or the first tape roller is removable, and an operating position in which the first and second cleaner pinch rollers are set to clean a transported card; and
a biasing mechanism configured to bias the first and second brackets in the operating position; and
a printhead positioned along the print path and adapted to deposit print material on a surface of the card.
6. The printer of claim 5, wherein the transport mechanism includes a cleaner roller driver adapted to drive at least one of the first and second cleaner pinch rollers or tape rollers to assist in the transport of the cards through the cleaner roller assembly.
7. The printer of claim 6, wherein the cleaner roller drive has a one-way clutch allowing the card to be pulled through the card cleaner roller assembly unhindered.
8. The printer of claim 5, wherein the transport mechanism includes a card feed roller adapted to receive a card passing through the cleaner pinch rollers of the card cleaner roller assembly.
9. The printer of claim 5, wherein the cleaner pinch rollers are coated with a debris-collecting material.
10. The printer of claim 5, wherein the biasing mechanism includes a spring coupled to both the first and second brackets.
11. The printer of claim 5, wherein either the first or second bracket includes a channel in which a portion of the other bracket can slide.