1. A composite utility knife blade, comprising:
a first edge, a second edge, a third edge located on an opposite side of the blade relative to the second edge, and a fourth edge defining at least one cutting edge located on an opposite side of the blade relative to the first edge;
first and second metal portions, wherein the first metal portion extends between the first edge and the second metal portion, extends between the second edge and the third edge, forms a backing extending from approximately one end of the at least one cutting edge to the other, and is formed of a steel heat treated to a hardness within the range of approximately 38 Rc to approximately 52 Rc, and the second metal portion defines the at least one cutting edge and extends between the second edge and the third edge, and is formed of a tool steel heat treated to a hardness within the range of approximately 60 Rc to approximately 75 Rc;
a weld region joining the first and second metal portions and extending throughout an interface between the first and second metal portions from approximately the second edge to approximately the third edge of the blade; and
further defining at least one notch formed in the first edge.
2. A composite utility knife blade, comprising:
a first edge, a second edge, a third edge located on an opposite side of the blade relative to the second edge, and a fourth edge defining at least one cutting edge located on an opposite side of the blade relative to the first edge;
first and second metal portions, wherein the first metal portion extends between the first edge and the second metal portion, extends between the second edge and the third edge, forms a backing extending from approximately one end of the cutting edge to the other, and is formed of a steel heat treated to a hardness within the range of approximately 38 Rc to approximately 52 Rc, and the second metal portion defines the cutting edge and extends between the second edge and the third edge, and is formed of a tool steel heat treated to a hardness within the range of approximately 60 Rc to approximately 75 Rc; and
a weld region joining the first and second metal portions and extending throughout an interface between the first and second metal portions from approximately the second edge to approximately the third edge of the blade;
wherein the at least one cutting edge defines a straight edge extending from approximately the second edge to approximately the third edge of the blade, and at least two facets formed on opposite sides of the blade relative to each other.
3. A composite utility knife blade comprising:
a first edge, a second edge, a third edge located on an opposite side of the blade relative to the second edge, and a fourth edge defining at least one cutting edge located on an opposite side of the blade relative to the first edge;
first means for forming a wear-resistant metal cutting edge defining a hardness within the range of approximately 60 Rc to approximately 75 Rc and extending from approximately the second edge to approximately the third edge;
second means for forming a metal backing to the first means and defining a hardness within the range of approximately 38 Rc to approximately 52 Rc, said second means extending between the first edge and the first means and extending from approximately the second edge to approximately the third edge; and
a weld region joining the first and second means and extending throughout an interface between the first and second means from approximately the second edge to approximately the third edge of the blade;
wherein the first means defines an approximately straight cutting edge extending from approximately the second edge to approximately the third edge of the blade; and
wherein the at least one cutting edge defines at least two facets located on opposite sides of the blade relative to each other.
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 producing a titania solution, comprising the steps of:
dissolving powder of titania in an acid solution and controlling a temperature of the titania-dissolved solution at 20\xb0 C. or below to produce a gel of amorphous titania;
mixing said gel of amorphous titania and an acid solution together to transform said gel of amorphous titania to a sol of amorphous titania; and
supplying an alkali solution to the solution containing said sol of amorphous titania to adjust a pH of the solution to 2 to 10.
2. The method according to claim 1, further comprising a step of heating the solution containing said sol of amorphous titania to crystallize said amorphous titania to thereby produce anatase titania.
3. The method according to claim 2, wherein the step of crystallizing said amorphous titania comprises a step of mixing particles of amorphous titania and water together, a step of applying ultrasonic waves to the particles of amorphous titania, and a step of heating the water containing the particles of amorphous titania applied with the ultrasonic waves, at a predetermined temperature to produce particles of anatase titania, and the step of mixing the particles of anatase titania into the solution containing said sol of amorphous titania, and then the step of heating said solution.
4. The method according to claim 1, wherein said titania solution is a material of a coating film formed as a film on the surface of a base material.
5. The method according to claim 4, wherein said titania solution contains silica.
6. A method of producing a titania solution, comprising the steps of:
mixing together titanium tetraalkoxide, alcohol, and water that is excessive in amount relative to said titanium tetraalkoxide, to produce particles of anatase titania and amorphous titania; then
separating said particles of anatase titania and said particles of amorphous titania from said solution and drying them; and thereafter
dissolving said particles of anatase titania and said particles of amorphous titania in an acid solution to obtain a dispersed liquid in which said anatase titania and said amorphous titania are dispersed.
7. The method according to claim 6, wherein a mixing mole ratio of said titanium tetraalkoxide relative to said water is 110\u02dc80.
8. The method according to claim 7, wherein said titanium tetraalkoxide is titanium tetraisopropoxide, and said alcohol is isopropanol.
9. The method according to claim 6, further comprising a step of heating said dispersed liquid to produce anatase-rutile titania.
10. The method according to claim 6, wherein said dispersed liquid contains the alcohol.
11. The method according to claim 6, wherein said dispersed liquid is a material of a coating film formed as a film on the surface of a base material.
12. The method according to claim 11, wherein said dispersed liquid contains silica.
13. The method according to claim 6, wherein a production ratio between said anatase titania and said amorphous titania is changed by changing a mixing mole ratio of said water relative to said titanium tetraalkoxide.
14. The method according to claim 6, wherein the step of dissolving said anatase titania and said amorphous titania in the acid solution is carried out while controlling a temperature of said acid solution at 20\xb0 C. or below.
15. The method according to claim 6, further comprising a step of supplying an alkali solution to said dispersed liquid to adjust a pH or said dispersed liquid to 2 to 10.