1. An aqueous composition comprising a mixed aqueous solution containing a chelating agent having a pH of from 1 to 7 and a zirconium compound.
2. An aqueous composition according to claim 1, wherein the chelating agent is an amino carboxylic acid or its derivative.
3. An aqueous composition according to claim 1, wherein the amino carboxylic acid is a monoamino monocarboxylic acid or monoamino dicarboxylic acid.
4. An aqueous composition according to claim 1, wherein the zirconium compound is water soluble.
5. An aqueous composition according to claim 1, wherein the zirconium compound is an inorganic salt, an organic salt or a complex.
6. An aqueous composition according to claim 1, wherein the zirconium compound is selected from a group consisting of zirconyl hydroxy chloride, oxy zirconium chloride, zirconyl ammonium carbonate, zirconyl sulfate, and zirconyl nitrate.
7. An aqueous composition according to claim 1, wherein the molar ratio of the zirconium compound to the chelating agent is from 1:0.1 to 1:4.
8. An aqueous composition according to claim 1, which further contains a pH modifier.
9. An aqueous composition according to claim 1, wherein the pH of the mixed aqueous solution is from 1 to 10.
10. A crosslinking agent for a water-soluble polymer, which comprises a mixed aqueous solution containing a chelating agent having a pH of from 1 to 7 and a zirconium compound.
11. A crosslinking agent for a water-soluble polymer according to claim 10, wherein the chelating agent is an amino carboxylic acid or its derivative.
12. A crosslinking agent for a water-soluble polymer according to claim 10, wherein the amino carboxylic acid is a monoamino monocarboxylic acid or monoamino dicarboxylic acid.
13. A crosslinking agent for a water-soluble polymer according to claim 10, wherein the zirconium compound is water soluble.
14. A crosslinking agent for a water-soluble polymer according to claim 10, wherein the zirconium compound is an inorganic salt, an organic salt or a complex.
15. A crosslinking agent for a water-soluble polymer according to claim 10, wherein the zirconium compound is selected from a group consisting of zirconyl hydroxy chloride, oxy zirconium chloride, zirconyl ammonium carbonate, zirconyl sulfate, and zirconyl nitrate.
16. A crosslinking agent for a water-soluble polymer according to claim 10, wherein the molar ratio of the zirconium compound to the chelating agent is from 1:0.1 to 1:4.
17. A crosslinking agent for a water-soluble polymer according to claim 10, which further contains a pH modifier.
18. A crosslinking agent for a water-soluble polymer according to claim 10, wherein the pH of the mixed aqueous solution is from 1 to 10.
19. A crosslinking agent for a water-soluble polymer according to claim 10, wherein the water-soluble polymer has hydroxyl groups in its molecule.
20. A surface treating agent comprising a mixed aqueous solution containing a chelating agent having a pH of from 1 to 7 and a zirconium compound.
21. A water-soluble polymer composition obtained by mixing the aqueous composition according to claim 1 with a water-soluble polymer.
22. A water-soluble polymer composition obtained by mixing the crosslinking agent for a water-soluble polymer according to claim 11 with the water-soluble polymer.
23. A water-soluble polymer composition according to claim 22, which is obtained by mixing 100 parts by weight (dried amount) of the water-soluble polymer with from 1 to 50 parts by weight (dried amount) of the crosslinking agent.
24. A method of cross-linking a water-soluble polymer comprising cross-linking the water-soluble polymer composition according to claim 22.
25. A substrate coated with a cross-linked water-soluble polymer obtained by applying the water-soluble polymer composition according to claim 22 to a substrate.
26. A cross-linked water-soluble polymer film or sheet obtained by forming the water-soluble polymer composition according to claim 23 to a film or sheet and by cross-linking the film or sheet.
27. An adhesive composition obtained by mixing a water-soluble polymer with the aqueous composition according to claim 1.
28. A coating composition obtained by mixing a water-soluble polymer with the aqueous composition according to claim 1.
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 hydraulic regenerative drive system for a vehicle comprising:
an electronic controller receiving a nominal engine throttle signal, generating a time-variant torque signal therefrom, and outputting a modified engine throttle signal, and wherein said torque signal and the vehicle’s engine torque corresponding to the modified throttle signal are equal to the torque corresponding to the nominal engine throttle signal;
a hydraulic control circuit receiving controlling signals from the electronic controller;
a reservoir in fluid communication with said hydraulic control circuit for storing hydraulic fluid;
a pumpmotor unit having a controlled-angle swash plate element providing variable displacement said pumpmotor unit being in fluid communication with said hydraulic control circuit and adapted for connection to the drive train of a vehicle;
an accumulator in fluid communication with said hydraulic control circuit;
a pumpmotor unit speed sensor and a pumpmotor unit pressure sensor providing measured speed and measured pressure signals to the electronic controller;
wherein said electronic control further generates said torque signal and said modified engine throttle signal on the basis of a mathematical model of drive train elements between the engine of said vehicle and said drive train connection-point of said pumpmotor unit, converts said torque signal to a swash plate angle, and controls (i) a controlled-torque retard mode of operation, in which said swash plate angle is controlled by said torque signal to impart a dynamically calculated retarding torque to said drive train, and said pumpmotor unit pumps fluid from said reservoir to said accumulator via said hydraulic control circuit, and (ii) a controlled-torque propulsion mode of operation, in which said swash plate angle is controlled by said torque signal to impart a dynamically calculated propelling torque to said drive train, and said pumpmotor unit motors under influence of fluid from said accumulator passing to said reservoir via said hydraulic control circuit; and
wherein said electronic controller performs said conversion between said torque signal and swash plate angle on the basis of searching predetermined characteristics of torque versus pressure versus speed for a set of swash plate angles to locate one or more closest torque values for the predetermined pressure and speed closest to the measured pumpmotor unit pressure and pumpmotor unit speed, and deriving a swash plate angle from the angle values corresponding to said closest torque values.
2. The system according to claim 1, wherein said electronic controller further controls a standby mode of operation in which said pumpmotor unit neither pumps nor drives, and further wherein said electronic controller enables said retard mode to occur only as a transition from said standby state, and enables said propulsion mode to occur only as a transition from said standby state.
3. The system according to claim 2, wherein said electronic controller further controls transition states between said modes, including:
a pre-propulsion state between standby mode an propulsion mode in which said controller determines that said pumpmotor unit pressure exceeds a threshold value before causing said propulsion mode to occur; and
a pre-retard state between standby mode and retard mode in which said controller determines that said pumpmotor unit pressure is lower than a threshold value before causing said retard mode to occur.
4. The system according to claim 3, wherein said transition states further include:
a terminate propulsion state between propulsion mode and standby mode;
a terminate retard state between retard mode and standby mode;
and wherein said electronic controller further determines in said transition states that respective elements of said hydraulic control circuit have correctly changed condition in response to said controlling signals before causing a respective mode to occur.