Silica sol binder for shell

Abstract

The invention discloses a silica sol binder for a shell. The silica sol binder comprises the following components in percentage by mass: 85-90% of alkaline silica sol, 0.6-1.2% of mesoporous silica nanospheres, 0.1-0.2% of calcium hydroxide, 0.3-0.5% of nano-crystalline cellulose, 0.15-0.25% of a dispersing auxiliary and the balance of water, wherein the dispersing auxiliary comprises sodium hexametaphosphate, poly(ethylene glycol) methyl ether-2000 and triethanolamine. The silica sol binder has higher drying speed, can shorten the interlayer drying time, improves the production efficiency ofthe shell, is short in shell manufacturing period and high in shell manufacturing efficiency, can improve the normal temperature strength of the shell, and is low in residual strength, easy to clean and suitable for producing castings with complicated geometrical shapes.

Description

technical field

[0001] The invention relates to the technical field of investment casting binders, in particular to a silica sol binder for mold shells. Background technique

[0002] The investment casting shell is composed of refractory materials, binders and some other additives. The binder directly affects the quality of the shell and castings, as well as the production cycle and cost, and plays a vital role. Silica sol adhesive has good cohesiveness, is easy to use, safe and environmentally friendly, and has been widely used. However, the shell-making drying speed of ordinary silica sol binder is relatively slow, and the strength of the molded shell at normal temperature is low, the shell-making cycle is long, and the production efficiency is low. Moreover, the residual strength of the molded shell made by ordinary silica sol binder is relatively high, and the molded shell is not easy to clean. These factors limit the popularization and application of silica sol binder...

Examples

Embodiment 1

[0022] A kind of silica sol binder for shell, its component and mass percent are:

[0023] 85% of alkaline silica sol, 0.6% of mesoporous silica nanospheres, 0.1% of calcium hydroxide, 0.3% of nanocellulose, 0.15% of dispersion aid, and the balance is water.

Embodiment 2

[0025] A kind of silica sol binder for shell, its component and mass percent are:

[0026] 85% of alkaline silica sol, 0.6% of mesoporous silica nanospheres, 0.1% of calcium hydroxide, 0.3% of nanocellulose, 0.15% of dispersion aid, and the balance is water.

[0027] The solid content of the alkaline silica sol is 30%, the particle diameter is 10nm, and the pH is 9.5.

[0028] Mesoporous silica nanospheres have a particle size of 100nm and a specific surface area of ​​500m 2 / g.

[0029] Nanocellulose has a diameter of 20 nm and a length of 200 nm.

[0030] Dispersion aids include sodium hexametaphosphate, polyethylene glycol monomethyl ether-2000, and triethanolamine, wherein the weight ratio of sodium hexametaphosphate, polyethylene glycol monomethyl ether-2000, and triethanolamine is 1:0.2:0.1.

[0031] The preparation method is as follows:

[0032] S1. First fully dissolve the dispersing aid in water, then add mesoporous silica nanospheres and nanocellulose, ultrasonic...

Embodiment 3

[0035] A kind of silica sol binder for shell, its component and mass percent are:

[0036] 88% of alkaline silica sol, 0.85% of mesoporous silica nanospheres, 0.15% of calcium hydroxide, 0.4% of nanocellulose, 0.6% of dispersion aid, and the balance is water.

[0037] The solid content of the alkaline silica sol is 32%, the particle diameter is 10nm, and the pH is 10.

[0038] Mesoporous silica nanospheres have a particle size of 100nm and a specific surface area of ​​600m 2 / g.

[0039] The nanocellulose has a diameter of 30 nm and a length of 450 nm.

[0040] The dispersion aid includes sodium hexametaphosphate, polyethylene glycol monomethyl ether-2000, and triethanolamine, wherein the weight ratio of sodium hexametaphosphate, polyethylene glycol monomethyl ether-2000, and triethanolamine is 1:0.25:0.15.

[0041] The preparation method is as follows:

[0042] S1. First fully dissolve the dispersing aid in water, then add mesoporous silica nanospheres and nanocellulose, ...

technical field

[0001] The invention relates to the technical field of investment casting binders, in particular to a silica sol binder for mold shells. Background technique

[0002] The investment casting shell is composed of refractory materials, binders and some other additives. The binder directly affects the quality of the shell and castings, as well as the production cycle and cost, and plays a vital role. Silica sol adhesive has good cohesiveness, is easy to use, safe and environmentally friendly, and has been widely used. However, the shell-making drying speed of ordinary silica sol binder is relatively slow, and the strength of the molded shell at normal temperature is low, the shell-making cycle is long, and the production efficiency is low. Moreover, the residual strength of the molded shell made by ordinary silica sol binder is relatively high, and the molded shell is not easy to clean. These factors limit the popularization and application of silica sol binder...

Examples

Embodiment 1

[0022] A kind of silica sol binder for shell, its component and mass percent are:

[0023] 85% of alkaline silica sol, 0.6% of mesoporous silica nanospheres, 0.1% of calcium hydroxide, 0.3% of nanocellulose, 0.15% of dispersion aid, and the balance is water.

Embodiment 2

[0025] A kind of silica sol binder for shell, its component and mass percent are:

[0026] 85% of alkaline silica sol, 0.6% of mesoporous silica nanospheres, 0.1% of calcium hydroxide, 0.3% of nanocellulose, 0.15% of dispersion aid, and the balance is water.

[0027] The solid content of the alkaline silica sol is 30%, the particle diameter is 10nm, and the pH is 9.5.

[0028] Mesoporous silica nanospheres have a particle size of 100nm and a specific surface area of ​​500m 2 / g.

[0029] Nanocellulose has a diameter of 20 nm and a length of 200 nm.

[0030] Dispersion aids include sodium hexametaphosphate, polyethylene glycol monomethyl ether-2000, and triethanolamine, wherein the weight ratio of sodium hexametaphosphate, polyethylene glycol monomethyl ether-2000, and triethanolamine is 1:0.2:0.1.

[0031] The preparation method is as follows:

[0032] S1. First fully dissolve the dispersing aid in water, then add mesoporous silica nanospheres and nanocellulose, ultrasonic...

Embodiment 3

[0035] A kind of silica sol binder for shell, its component and mass percent are:

[0036] 88% of alkaline silica sol, 0.85% of mesoporous silica nanospheres, 0.15% of calcium hydroxide, 0.4% of nanocellulose, 0.6% of dispersion aid, and the balance is water.

[0037] The solid content of the alkaline silica sol is 32%, the particle diameter is 10nm, and the pH is 10.

[0038] Mesoporous silica nanospheres have a particle size of 100nm and a specific surface area of ​​600m 2 / g.

[0039] The nanocellulose has a diameter of 30 nm and a length of 450 nm.

[0040] The dispersion aid includes sodium hexametaphosphate, polyethylene glycol monomethyl ether-2000, and triethanolamine, wherein the weight ratio of sodium hexametaphosphate, polyethylene glycol monomethyl ether-2000, and triethanolamine is 1:0.25:0.15.

[0041] The preparation method is as follows:

[0042] S1. First fully dissolve the dispersing aid in water, then add mesoporous silica nanospheres and nanocellulose, ...

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