1. Polymer material which is obtainable by a process comprising:
homogenizing a mixture comprised of:
40 to 85 wt. % of starch andor starch derivative,
15 to 55 wt. % of plasticizer, and
0.01 to 7 wt. % of an epoxide group-containing polymer having a molecular weight (Mw) of 1,000 to 25,000,
said homogenizing being performed by supplying thermal andor mechanical energy to the mixture and setting the water content of the mixture to less than approximately 7 wt. %.
2. Polymer material which is obtainable by a process comprising:
homogenizing a mixture comprised of:
50 wt. % to 85 wt. % of starch andor starch derivative,
15 to 50 wt. % of plasticizer, and
0.01 to 7 wt. % of an epoxide group-containing polymer,
said homogenizing being performed by supplying thermal andor mechanical energy to the mixture and setting the water content of the mixture to less than approximately 7 wt. %.
3. Polymer material according to claim 2, wherein the mixture comprises 50 to 80 wt. % of the starch andor starch derivative.
4. Polymer material according to claim 2, wherein the mixture comprises 20 to 50 wt. % of the plasticizer.
5. Polymer material according to claim 2, wherein the mixture comprises contains 0.01 to 5 wt. % of the epoxide group-containing polymer.
6. Polymer material according to claim 2, wherein the polymer material is biologically degradable in accordance with EN 13432.
7. Polymer material according to claim 2, wherein the plasticizer is selected from the group consisting of ethylene glycol, propylene glycol, glycerol, 1,4-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6hexanediol, 1,2,6-hexanetriol, 1,3,5-hexanetriol, neopentyl glycol, sorbitol acetate, sorbitol diacetate, sorbitol monoethoxylate, sorbitol diethoxylate, sorbitol hexaethoxylate, sorbitol dipropoxylate, aminosorbitol, trihydroxymethylaminomethane, glucosePEG, the reaction product of ethylene oxide with glucose, trimethylol propane monoethoxylate, mannitol monoacetate, mannitol monoethoxylate, butylglucoside, glucose monoethoxylate, \u03b1-methylglucoside, the sodium salt of carboxymethyl sorbitol, polyglycerol monoethoxylate, erythritol, pentaerythritol, arabitol, adonitol, xylitol, mannitol, iditol, galactitol, allitol, sorbitol, polyvalent alcohols in general, glycerol esters, formamide, N-methylformamide, DMSO, mono-and diglycerides, alkylamides, polyols, trimethyl propane, polyvinyl alcohol having 3 to 20 repeat units, polyglycerols having 2 to 10 repeat units, derivatives thereof, and mixtures thereof.
8. Polymer material according to claim 2, wherein the plasticizer has a solubility parameter (Hildebrand parameter) d(SI) of 30 to 50 MPa12 within a temperature range of approximately 150 to 300\xb0 C.
9. Polymer material according to claim 2, wherein the mixture contains glycerol andor sorbitol as the plasticizer.
10. Polymer material according to claim 2, wherein the water content of the mixture is set to 1 to 7 wt. %.
11. Polymer material according to claim 2, wherein the epoxide group-containing polymer is a copolymer.
12. Polymer material according to claim 2, wherein the epoxide group-containing polymer is a glycidyl (meth)acrylate-containing polymer.
13. Polymer material according to claim 12, wherein the glycidyl (meth)acrylate-containing polymer is a copolymer comprised of (a) styrene andor ethylene andor methyl methacrylate andor methyl acrylate and (b) glycidyl (meth)acrylate.
14. Polymer material according to claim 12, wherein the glycidyl (meth)acrylate-containing polymer is an epoxide group-containing copolymer based on styrene, ethylene, acrylic ester andor methacrylic ester.
15. Polymer material according to claim 12, wherein the glycidyl (meth)acrylate-containing polymer is a copolymer selected from the group consisting of styrene-methyl methacrylate-glycidyl methacrylate, ethylene-methyl acrylate-glycidyl methacrylate and ethylene-glycidyl methacrylate.
16. Polymer material according to claim 12, wherein the glycidyl (meth)acrylate-containing polymer contains glycidyl (meth)acrylate in a quantity of 1 to 60 wt. % based on the total composition of the glycidyl (meth) acrylate-containing polymer.
17. Polymer material according to claim 12, wherein the glycidyl (meth)acrylate-containing polymer contains glycidyl (meth)acrylate in a quantity of 5 to 55 wt. % based on the total composition of the glycidyl (meth) acrylate-containing polymer.
18. Polymer material according to claim 12, wherein the glycidyl (meth)acrylate-containing polymer contains glycidyl (meth)acrylate in a quantity of 45 to 52 wt. % based on the total composition of the glycidyl (meth) acrylate-containing polymer.
19. Polymer material according to claim 2, wherein the epoxide group-containing polymer has a molecular weight (Mw) of 1,000 to 25,000.
20. Polymer material according to claim 2, wherein the mixture is homogenised by dispersing, stifling, kneading andor extruding.
21. Polymer material according to claim 2, wherein the mixture is homogenised by extrusion.
22. Polymer material according to claim 2, wherein the mixture is homogenized by shear forces acting on the mixture.
23. Polymer material according to claim 2, wherein during homogenization or subsequent extrusion the mixture is heated to a temperature of 90 to 200\xb0 C.
24. Polymer material according to claim 2, wherein the water content of the mixture is set to less than 5 wt. %.
25. Polymer material according to claim 2, wherein the water content of the mixture is set during homogenization.
26. Polymer material according to claim 2, wherein the water content of the mixture is set by degassing the mixture.
27. Polymer material according to claim 2, wherein the water content of the mixture is set by drying the mixture during homogenization or subsequent extrusion.
28. Polymer material according to claim 2, wherein the polymer material can be thermoplastically processed.
29. Polymer material according to claim 2, wherein the polymer material is a film having a tensile strength in accordance with DIN 53455 of 2 to 10 Nmm2.
30. Polymer material according to claim 2, wherein the polymer material is a film having an elongation at break in accordance with DIN 53455 of 80 to 200%.
31. Polymer material according to claim 2, wherein the polymer material is in the form of an article of manufacture selected from the group consisting of molded parts, films, and fibers.
32. Polymer material according to claim 2, wherein the mixture comprises 50 to 75 wt. % of the starch andor starch derivative.
33. Polymer material according to claim 2, wherein the mixture comprises 55 to 72 wt. % of the starch andor starch derivative.
34. Polymer material according to claim 2, wherein the mixture comprises 59 to 67 wt. % of the starch andor starch derivative.
35. Polymer material according to claim 2, wherein the mixture contains 25 to 45 wt. % of the plasticizer.
36. Polymer material according to claim 2, wherein the mixture contains 28 to 42 wt. % of the plasticizer.
37. Polymer material according to claim 2, wherein the mixture contains 30 to 40 wt. % of the plasticizer.
38. Polymer material according to claim 2, wherein the mixture contains 35 to 38 wt. % of the plasticizer.
39. Polymer material according to claim 2, wherein the mixture contains 0.05 to 3 wt. % of the epoxide group-containing polymer.
40. Polymer material according to claim 2, wherein the mixture contains 0.1 to 2 wt. % of the epoxide group-containing polymer.
41. Polymer material according to claim 2, wherein the water content of the mixture is set to 1.5 to 6 wt. %.
42. Polymer material according to claim 2, wherein the water content of the mixture is set to 1.5 to 3 wt %.
43. Polymer material according to claim 2, wherein the epoxide group-containing polymer has a molecular weight (Mw) of 3,000 to 10,000.
44. Polymer material according to claim 2, wherein during homogenization or subsequent extrusion the mixture is heated to a temperature of 120 to 180\xb0 C.
45. Polymer material according to claim 2, wherein during homogenization or subsequent extrusion the mixture is heated to a temperature of 130 to 160\xb0 C.
46. Polymer material according to claim 2, wherein the water content of the mixture is set to less than 3 wt. %.
47. Polymer material according to claim 2, wherein the water content of the mixture is set by degassing the mixture while in the form of a melt.
48. Polymer material according to claim 2, wherein the polymer material is a film having a tensile strength in accordance with DIN 53455 of 4 to 8 Nmm2.
49. Polymer material according to claim 2, wherein the polymer material is a film having an elongation at break in accordance with DIN 53455 of 120 to 180%.
50. Method for producing a polymer material comprising:
(a) producing a mixture comprised of:
45 wt. % to 85 wt. % of starch andor starch derivative;
15 to 55 wt. % of plasticizer; and
0.01 to 7% wt. of an epoxide group-containing polymer,
(b) homogenizing the mixture by supplying thermal andor mechanical energy; and
(c) setting the water content of the mixture to less than approximately 7 wt. %.
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 method of manufacturing a resistance variable element comprising:
a first electrode forming step of forming a first electrode on a substrate;
a first resistance variable layer forming step of forming a first resistance variable layer comprising transition metal oxide, on the first electrode;
an interlayer insulating layer forming step of forming an interlayer insulating layer on the first resistance variable layer;
a through-hole forming step of forming a through-hole on the first resistance variable layer such that the through-hole penetrates the interlayer insulating layer;
a second resistance variable layer forming step of forming a second resistance variable layer comprising transition metal oxide such that the second resistance variable layer is in contact with the first resistance variable layer only in the one of the openings of the through-hole, inside the through-hole, the second resistance variable layer being different in resistivity from the first resistance variable layer; and
a step of forming a second electrode on the second resistance variable layer; wherein
an electric resistance between the first electrode and the second electrode changes by application of an electric pulse between the first electrode and the second electrode.
2. The method of manufacturing the resistance variable element according to claim 1, wherein the first resistance variable layer covers entire of the one of the openings of the through-hole and protrudes outward over the one of the openings.
3. The method of manufacturing the resistance variable element according to claim 1, further comprising:
an etching stopper layer forming step of forming an etching stopper layer on the first resistance variable layer, between the first resistance variable layer forming step and the interlayer insulating layer forming step, the etching stopper layer having a resistance to etching using an etching gas containing a fluorine compound gas;
wherein in the interlayer insulating layer forming step, the interlayer insulating layer is formed on the first resistance variable layer and the etching stopper layer.
4. The method of manufacturing the resistance variable element according to claim 3, wherein in the through-hole forming step, the interlayer insulating layer is etched using an etching gas containing a fluorine-compound gas, and the etching stopper layer is etched using an inactive gas.
5. A resistance variable element comprising:
a substrate;
a first electrode formed on the substrate;
a second electrode; and
an interlayer insulating layer;
wherein a through-hole is formed to penetrate the interlayer insulating layer;
a first resistance variable layer comprising transition metal oxide is formed outside the through-hole such that the first resistance variable layer is connected to the first electrode located outside the though-hole;
a second resistance variable layer comprising transition metal oxide is formed inside the through-hole;
the second electrode is formed on the second resistance variable layer;
the first resistance variable layer is different in resistivity from the second resistance variable layer;
the first resistance variable layer and the second resistance variable layer are in contact with each other only in one of openings of the through-hole, which opening is closer to the substrate; and
an electric resistance between the first electrode and the second electrode changes by application of an electric pulse between the first electrode and the second electrode.
6. The resistance variable element according to claim 5,
wherein the resistivity of the transition metal oxide of the first resistance variable layer is higher than the resistivity of the transition metal oxide of the second resistance variable layer.
7. The resistance variable element according to claim 5,
wherein the second resistance variable layer covers a bottom portion and a side wall of the through-hole, the resistance variable element further comprising:
an electrode filled inside the through-hole such that the electrode is located on the second resistance variable layer.
8. The resistance variable element according to claim 5,
wherein the first resistance variable layer covers entire of the opening of the through-hole which is closer to the substrate and protrudes outward over the entire opening when viewed from a thickness direction of the interlayer insulating layer; and
the second resistance variable layer covers entire of the one of the openings of the through-hole and does not protrude outward over the one of the openings when viewed from the thickness direction of the interlayer insulating layer.
9. The resistance variable element according to claim 5,
wherein each of the transition metal oxide of the first resistance variable layer and the transition metal oxide of the second resistance variable layer is an oxide of at least one transition metal which is selected from a group consisting of Ta, Hf and Zr.
10. The resistance variable element according to claim 1,
wherein the transition metal oxide of the first resistance variable layer and the transition metal oxide of the second resistance variable layer are tantalum oxides, respectively;
when one of the tantalum oxides is expressed as TaOx, 0.8\u2266x\u22661.9 is satisfied; and
when the other tantalum oxide is expressed as TaOy, x<y is satisfied.
11. The resistance variable element according to claim 5,
wherein the resistivity of the transition metal oxide of the first resistance variable layer is lower than the resistivity of the transition metal oxide of the second resistance variable layer.
12. The resistance variable element according to claim 5,
wherein the resistivity of the transition metal oxide of the first resistance variable layer is higher than the resistivity of the transition metal oxide of the second resistance variable layer; comprising:
an etching stopper layer formed between the interlayer insulating layer and the first resistance variable layer, the etching stopper layer having a resistance to etching using an etching gas containing a fluorine compound gas, the through-hole penetrating the interlayer insulating layer and the etching stopper layer.
13. The resistance variable element according to claim 12,
wherein the etching stopper layer comprises at least one material selected from a group consisting of silicon nitride (SiN), silicon oxynitride (SiON) and silicon carbon nitride (SiCN).
14. The resistance variable element according to claim 12 or 13,
wherein the etching stopper layer has a thickness which is not less than 5 nm.
15. A resistance variable memory device comprising:
a substrate;
a plurality of first wires formed within a first plane parallel to a main surface of the substrate to extend in parallel with each other in a first direction;
a plurality of second wires formed within a second plane parallel to the first plane to extend in parallel with each other in a second direction and three-dimensionally cross the plurality of first wires, respectively; and
memory cells respectively formed at three-dimensional cross-points of the first wires and the second wires;
each of the memory cells including the resistance variable element as recited in claim 5 and a current controlling element connected in series with the resistance variable element; and
the interlayer insulating layer being formed between the first plane and the second plane.
16. The resistance variable memory device according to claim 15,
wherein the current controlling element covers one of openings of the through-hole corresponding to the resistance variable element constituting a memory cell, which opening is not covered with the first resistance variable layer, the memory cell including the current controlling element and the resistance variable element.
17. The resistance variable memory device according to claim 15,
wherein the current controlling element is formed at one of both sides of the interlayer insulating layer, where the first resistance variable layer of the resistance variable element constituting a memory cell is provided, the memory cell including the current controlling element and the resistance variable element.
18. The resistance variable memory device according to claim 15,
wherein the current controlling element is at least one element selected from a group consisting of a MIM diode, a MSM diode, and a varistor.