Shell mold structures and processes and compositions for forming the same

Claim 1

THE METHOD OF PREPARING A POROUS SHELL MOLD WHICH COMPRISES APPLYING TO A FROZEN MERCURY PATTERN OF AN OBJECT TO BE CAST A SLURRY-LIKE INVESTMENT COMPOSITION CAPABLE OF FORMING A THIN SHELL LAYER ADHERING TO SAID PATTERN AT VERY LOW TEMPERATURE BELOW THE FREEZING TEMPERATURE OF THE PATTERN MATERIAL, WHICH COMPOSITION CONSISTS ESSENTIALLY OF SOLID INGREDIENTS CONSISTING OF A PREDOMINANT AMOUNT OF REFRACTORY PARTICLES, AN IORGANIC BINDER FOR SAID REFRACTORY PARTICLES CONSTITUTING 0.25% TO 5% OF SAID SOLID INGREDIENTS ANDCOMPOSED OF A METAL FLUORIDE TOGETHER WITH A BORON COMPOUND SELECTED FROM THE GROUPS CONSISTING OF BORIC ACID, BORIC OXIDE AND METAL BORATES, AND WHICH INORGANIC BINDER IS PRESENT IN A SUFFICIENT AMOUNT AND IS EFFECTIVE UPON HEATING SAID SHELL LAYER TO RAISED TEMPERATURE OF AT LEAST 750*C. TO CAUSE SAID REFRACTORY PARTICLES AND SAID INORGANIC BINDER OF SAID SHELL LAYER TO COMBINE INTO A HARD SHELL LAYER, AN ORGANIC RESINOUS BINDER FOR SAID REFRACTORY PARTICLES AND SAID INORGANIC BINDER CONSTITUTING 0.25% TO 7% OF SAID SOLID INGREDIENTS, WHICH ORGANIC BINDER IS PRESENT IN SUFFICIENT AMOUNT AND HAS THE PROPERTY OF ADHERING TO SAID FROZEN PATTERN AND OF BINDING SAID REFRACTORY PARTICLES AND INORGANIC BINDER INTO A SELF SUPPORTING SHELL LAYER AT TEMPERATURES FROM SAID VERY LOW TEMPERATURES UP TO SAID RAISED TEMPERATURE AND OF CAUSING SAID ORGANIC BINDER TO BE MODIFIED AND DRIVEN OFF WHEN SAID SHELL LAYER IS HEATED TO SAID RAISED TEMPERATURE, AND A LIQUID CARRIER WHICH IS AT LEAST A COLLODIAL SOLVENT FOR SAID RESINOUS BINDER AT SAID VERY LOW TEMPERATURES AND HAS A BOILING POINT AT LOW TEMPERATURES AT MOST 50*C. HIGHER THAN SAID FREEZING TEMPERATURE, WHICH CARRIER IS PRESENT IN SUFFICIENT AMOUNT OF MAINTAIN IN AT LEAST COLLOIDAL SOLUTION AN AMOUNT OF SAID RESINOUS BINDER WHICH CONSTITUTES AT LEAST 0.25% OF SAID SOLID INGREDIENTS AND TO PROVIDE WITH SAID SOLID INGREDEINTS A SLURRY OF SUFFICIENTLY LOW VISCOITY TO ENBALE APPLICATION OF SAID SLURRY AS A COATING LAYER TO SAID FROZEN.

Claim 2

THE METHOD OF PREPARING A POROUS SHELL MOLD WHICH COMPRISES APPLYING TO A FROZEN MERCURY PATTERN OF AN OBJECT TO BE CAST A SLURRY-LIKE INVESTMENT COMPOSITION CAPABLE OF FORMING A THIN SHELL LAYER ADHERING TO SAID PATTERN AT VERY LOW TEMPERATURE BELOW THE FREEZING TEMPERATURE OF THE PATTERN MATERIAL, WHICH COMPOSITION CONSISTS ESSENTIALLY OF SOLID INGREDIENTS CONSISTING OF A PREDOMINANT AMOUNT OF REFRACTORY PARTICLES, AN IORGANIC BINDER FOR SAID REFRACTORY PARTICLES CONSTITUTING 0.25% TO 5% OF SAID SOLID INGREDIENTS ANDCOMPOSED OF A METAL FLUORIDE TOGETHER WITH A BORON COMPOUND SELECTED FROM THE GROUPS CONSISTING OF BORIC ACID, BORIC OXIDE AND METAL BORATES, AND WHICH INORGANIC BINDER IS PRESENT IN A SUFFICIENT AMOUNT AND IS EFFECTIVE UPON HEATING SAID SHELL LAYER TO RAISED TEMPERATURE OF AT LEAST 750*C. TO CAUSE SAID REFRACTORY PARTICLES AND SAID INORGANIC BINDER OF SAID SHELL LAYER TO COMBINE INTO A HARD SHELL LAYER, AN ORGANIC RESINOUS BINDER FOR SAID REFRACTORY PARTICLES AND SAID INORGANIC BINDER CONSTITUTING 0.25% TO 7% OF SAID SOLID INGREDIENTS, WHICH ORGANIC BINDER IS PRESENT IN SUFFICIENT AMOUNT AND HAS THE PROPERTY OF ADHERING TO SAID FROZEN PATTERN AND OF BINDING SAID REFRACTORY PARTICLES AND INORGANIC BINDER INTO A SELF SUPPORTING SHELL LAYER AT TEMPERATURES FROM SAID VERY LOW TEMPERATURES UP TO SAID RAISED TEMPERATURE AND OF CAUSING SAID ORGANIC BINDER TO BE MODIFIED AND DRIVEN OFF WHEN SAID SHELL LAYER IS HEATED TO SAID RAISED TEMPERATURE, AND A LIQUID CARRIER WHICH IS AT LEAST A COLLODIAL SOLVENT FOR SAID RESINOUS BINDER AT SAID VERY LOW TEMPERATURES AND HAS A BOILING POINT AT LOW TEMPERATURES AT MOST 50*C. HIGHER THAN SAID FREEZING TEMPERATURE, WHICH CARRIER IS PRESENT IN SUFFICIENT AMOUNT OF MAINTAIN IN AT LEAST COLLOIDAL SOLUTION AN AMOUNT OF SAID RESINOUS BINDER WHICH CONSTITUTES AT LEAST 0.25% OF SAID SOLID INGREDIENTS AND TO PROVIDE WITH SAID SOLID INGREDEINTS A SLURRY OF SUFFICIENTLY LOW VISCOITY TO ENBALE APPLICATION OF SAID SLURRY AS A COATING LAYER TO SAID FROZEN.