CN115740356A - Water-based release agent for aluminum alloy die casting and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of casting, and discloses a water-based release agent for aluminum alloy die casting and a preparation method thereof, wherein the preparation method comprises the following steps: solvent, composite emulsion, emulsifier, defoamer, phosphate compound and silicone oil; the release agent prepared by the invention can form a layer of compact and smooth protective film on the surface of the mold, and is used for isolating the metal liquid and the mold in molding processing.

Description

A kind of aluminum alloy die-casting water-based release agent and preparation method thereof

technical field

The invention relates to the technical field of casting, in particular to a water-based release agent for aluminum alloy die-casting and a preparation method thereof.

Background technique

As a metal forming method using a die, there are a casting method and a die forging method. Examples of the casting method include a low-pressure casting method, a pressure casting method, and the like.

Release agent, also known as release agent, is a product designed for special molding and forming. It is a chemical additive used for lubrication in metal processing production. When the release agent is used, it will form a mold on the surface of the mold. A dense smooth film.

The Chinese invention patent whose application publication number is CN107999692A discloses a water-based release agent for die-casting aluminum alloys, which is composed of mineral oil, lubricant, silicone oil, surfactant, preservative, wetting agent, stabilizer, Composed of thickener and water, the mass percentage of its components is: machine oil 20-30, silicone oil 10-15, silicon dioxide 1-5, stearic acid 5-7, polyoxyethylene fatty acid ester 8-10, Polyoxyethylene oleyl ether 4~6, organic molybdenum compound 0.5~1.5, beeswax 3~5, ethanol 0.5~1.5, sodium nitrite 0.5~1, triethanolamine 0.5~2, organosilicon wetting agent 0.5~2, Thickener 0.5-1, sodium benzoate 0.5-2, sodium phosphate 0.5-2, sorbic acid 0.5-1, water 25-35. The stability and release performance of the die-casting aluminum alloy water-based release agent of the invention need to be further improved.

Based on this, we propose a water-based release agent for aluminum alloy die-casting, hoping to solve the deficiencies in the prior art.

Contents of the invention

(1) Solved technical problems

Aiming at the deficiencies of the prior art, the invention provides a water-based release agent for aluminum alloy die-casting.

(2) Technical solution

To achieve the above object, the present invention provides the following technical solutions:

A water-based release agent for aluminum alloy die-casting, comprising: 80-90 parts of solvent, 10-20 parts of composite emulsion, 1-2 parts of emulsifier, 1-1.5 parts of defoamer, 2-5 parts by weight Phosphate ester compounds, 1-2 parts of silicone oil.

As a further technical solution, it includes 12-16 parts of composite emulsion and 1.2-1.6 parts of silicone oil, wherein the weight ratio of composite emulsion to silicone oil is 10:1.

As a further technical scheme, the preparation method of the composite emulsion is:

The raw material components are mixed together sequentially, and pre-emulsified to obtain a pre-emulsion;

Take 10% mass of pre-emulsion, add initiator solution to it, stir for 15 minutes, then gradually add the rest of the pre-emulsion, stir for 2 hours, and finally adjust the pH to 7.5 with ammonia water to obtain the product.

As a further technical solution: the raw material components include hydroxyethyl methacrylate, perfluoroalkyl ethyl methacrylate, styrene, butyl acrylate, isobutoxymethyl-acrylamide, acrylic acid, 4 - Styrenic acid, sodium dodecyl diphenyl ether disulfonate and deionized water.

As a further technical solution, the silicone oil is formed by ring-opening polymerization reaction using octamethylcyclotetrasiloxane and divinyltetramethyldisiloxane as raw materials under the action of an acid or alkali catalyst.

As a further technical solution, the catalyst is the hydroxide of alkali metal K and Na.

A preparation method of an aluminum alloy die-casting water-based release agent: comprising:

Mix the emulsifier, phosphate ester compound, and silicone oil together to obtain a mixture;

Add compound emulsion, solvent, and defoamer to the mixture in sequence, and mix evenly to obtain a water-based release agent.

(3) Beneficial effects

Compared with the prior art, the present invention provides a water-based release agent for aluminum alloy die-casting, which has the following beneficial effects:

The release agent prepared by the present invention can form a dense and smooth protective film on the surface of the mold, which is used to isolate the molten metal and the mold during the molding process. The release agent of the present invention can be closely bonded to the surface of the mold. It is not easy to fall off and damage, and there will be no reaction or adhesion between the formed protective film and the metal, and the formed metal casting product can be peeled off very well.

In the present invention, by combining the prepared composite emulsion with silicone oil, the surface of the metal substrate can be oriented, and a static lubricating film layer can be formed through adsorption, thereby reducing the friction between them and forming an excellent mold release effect, and then It can improve the surface quality of metal casting products.

The mold release agent prepared by the invention has multiple characteristics such as rapid defoaming, long foam suppression time, and strong mold release properties, and can have good lubricating properties under high temperature conditions, thereby helping to improve the quality of castings and production efficiency. The friction between the casting and the mold is reduced, so that the direct contact between the casting and the mold can be reduced, the wear of the mold can be reduced, the life of the mold can be prolonged, and the surface quality of the casting can be improved.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the following description, a lot of specific details are set forth in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described here, and those skilled in the art can do it without departing from the meaning of the present invention. By analogy, the present invention is therefore not limited to the specific examples disclosed below.

A water-based release agent for aluminum alloy die-casting, comprising: 80-90 parts of solvent, 10-20 parts of composite emulsion, 1-2 parts of emulsifier, 1-1.5 parts of defoamer, 2-5 parts by weight Phosphate ester compounds, 1-2 parts of silicone oil.

The solvent that the present invention adopts is water;

The polyether type defoamer used in the defoamer used;

The emulsifier is a commercially available emulsifier OP-10; by using the emulsifier, the dispersed phase can be dispersed in the continuous phase in the form of micro-droplets (micron-sized) during the emulsification process, and the emulsifier reduces the concentration of each component in the mixed system. Interfacial tension, and form a stronger film on the surface of the droplet or form an electric double layer on the surface of the droplet due to the charge given by the emulsifier, preventing the droplets from aggregating with each other and maintaining a uniform emulsion.

Phosphate compounds are selected from one or more of diisopropyl phosphate, isopropyl phosphate, dioctyl phosphate phosphonate, octyl phosphate, dibutyl phosphate, and isodecyl phosphate;

It includes 12-16 parts of composite emulsion and 1.2-1.6 parts of silicone oil, wherein the weight ratio of composite emulsion to silicone oil is 10:1.

Described composite emulsion preparation method is:

The raw material components are mixed together sequentially, and pre-emulsified to obtain a pre-emulsion;

Take 10% mass of pre-emulsion, add initiator solution to it, stir for 15 minutes, then gradually add the remaining pre-emulsion, stir and react for 2 hours, and finally use ammonia water to adjust the pH to 7.5 to obtain; Agent solution is the ammonium persulfate solution that mass fraction is 5%;

In parts by weight, the raw material components include: 10 parts of hydroxyethyl methacrylate, 5 parts of perfluoroalkyl ethyl methacrylate, 15 parts of styrene, 6 parts of butyl acrylate, 3 parts of isobutoxymethacrylate base - acrylamide, acrylic acid, 2 parts 4-styrene acid, 4 parts sodium dodecyl diphenyl ether disulfonate, and 100 parts deionized water.

Table 1 composite emulsion performance index:

The silicone oil is formed by taking octamethylcyclotetrasiloxane and divinyltetramethyldisiloxane as raw materials through ring-opening polymerization under the action of an acid or alkali catalyst.

The catalyst is the hydroxide of alkali metal K and Na, and potassium hydroxide is preferably used in the present invention.

The concrete preparation method of silicone oil among the present invention is:

Add octamethylcyclotetrasiloxane to the reaction kettle, blow nitrogen into the reaction kettle, discharge the air in the reaction kettle, then adjust the temperature to 80°C, keep it warm for 10min, and then add divinyltetramethyldisilica oxane and potassium hydroxide, raise the temperature to 95°C, keep the temperature for 2.5 hours, then add 2,6-dinitro-p-cresol, adjust the pressure in the reactor to -0.05MPa, and keep the temperature at 152°C for 4.5 Hours, then cooled and filtered, that is.

A preparation method of an aluminum alloy die-casting water-based release agent: comprising:

According to each part by weight, add 1-2 parts of emulsifier OP-10, 2-5 parts of dioctyl phosphonic acid phosphate, and 1.2-1.6 parts of silicone oil into the stirring device in sequence, and stir at 150r/min for 30min at room temperature , to get a mixture;

Add 12-16 parts of composite emulsion, 80-90 parts of water, and 1-1.5 parts of defoamer to the mixture in sequence, and continue stirring at a speed of 200r/min for 1 hour to obtain a water-based release agent; the weight ratio of composite emulsion to silicone oil is 10:1.

The components in the introduced composite emulsion can provide hydrophobicity and permeability, and have a strong effect on reducing surface tension, and the introduction of the prepared silicone oil strengthens the release property of the release agent itself.

The following are specific examples:

Example 1

A preparation method of an aluminum alloy die-casting water-based release agent: comprising:

Add 1 part of emulsifier OP-10, 2 parts of dioctyl phosphonic acid phosphate, and 1.2 parts of silicone oil to the stirring device in sequence, and stir at 150 r/min for 30 minutes at room temperature to obtain a mixture;

Add 12 parts of composite emulsion, 80 parts of water, and 1 part of defoamer to the mixture in sequence, and continue to stir at 200 r/min for 1 hour to obtain a water-based release agent; the weight ratio of composite emulsion to silicone oil is 10:1.

Adhesion test

Before the aluminum alloy test piece is tested, the test piece is heated in an oven at 200°C for 30 minutes, and then cooled in a desiccator. Before the test, accurately measure the mass of the test piece, accurate to ±0.1mg.

The aluminum alloy test pieces coated with release agents with different weight ratios of composite emulsion and silicone oil (with the same quality of composite emulsion) were placed in an oven at 110°C for 30 minutes and then air-cooled. Cool in a desiccator for a certain period of time. Measure the mass of the aluminum alloy test piece, accurate to ±0.1mg, and calculate the adhesion amount from the difference between the mass before and after the test;

Table 2

由表2可以看出，通过采用不同的复合乳液与硅油重量份比的脱模剂，其附着力明显不同。

It can be seen from Table 2 that the adhesive force is obviously different by using the release agent with different weight ratios of composite emulsion and silicone oil.

Example 2

A preparation method of an aluminum alloy die-casting water-based release agent: comprising:

According to parts by weight, 1.2 parts of emulsifier OP-10, 3 parts of dioctyl phosphonate and 1.3 parts of silicone oil were sequentially added to the stirring device, and stirred at a speed of 150 r/min for 30 minutes at room temperature to obtain a mixture;

Add 13 parts of composite emulsion, 82 parts of water, and 1.4 parts of defoamer to the mixture in sequence, and continue to stir at 200 r/min for 1 hour to obtain a water-based release agent; the weight ratio of composite emulsion to silicone oil is 10:1.

Example 3

A preparation method of an aluminum alloy die-casting water-based release agent: comprising:

According to parts by weight, 1.6 parts of emulsifier OP-10, 4 parts of dioctyl phosphonate and 1.5 parts of silicone oil were sequentially added to the stirring device, and stirred at room temperature for 30 minutes at a speed of 150 r/min to obtain a mixture;

Add 15 parts of composite emulsion, 86 parts of water, and 1.2 parts of defoamer to the mixture in sequence, and continue to stir at 200 r/min for 1 hour to obtain a water-based release agent; the weight ratio of composite emulsion to silicone oil is 10:1.

Example 4

A preparation method of an aluminum alloy die-casting water-based release agent: comprising:

In parts by weight, 2 parts of emulsifier OP-10, 5 parts of dioctyl phosphonate and 1.6 parts of silicone oil were sequentially added to the stirring device, and stirred at room temperature for 30 minutes at a speed of 150 r/min to obtain a mixture;

Add 16 parts of composite emulsion, 90 parts of water, and 1.5 parts of defoamer to the mixture in sequence, and continue to stir at 200 r/min for 1 hour to obtain a water-based release agent; the weight ratio of composite emulsion to silicone oil is 10:1.

Comparative example 1:

A preparation method of an aluminum alloy die-casting water-based release agent: comprising:

Add 1 part of emulsifier OP-10, 2 parts of dioctyl phosphonic acid phosphate, and 1.2 parts of silicone oil to the stirring device in sequence, and stir at 150 r/min for 30 minutes at room temperature to obtain a mixture;

Add 12 parts of polyacrylic acid emulsion, 80 parts of water, and 1 part of defoamer to the mixture in sequence, and continue to stir at 200 r/min for 1 hour to obtain a water-based release agent. The solid content of the polyacrylic acid emulsion is 32.6%.

test:

The demoulding performance test was carried out on the sample of the embodiment and the comparative example. The detection method was: dilute the die-casting release agent of the embodiment and the comparative example with deionized water at a ratio of 1:150, and spray the diluted solution evenly on a surface heated to 280°C. Polish the smooth steel plate, insert the part of the steel plate sprayed with release agent into the molten 7075 aluminum alloy within 5 seconds, and take it out after 15 seconds.

Evaluate the performance standard of the release agent: use the quality change of the steel plate after dipping to classify the release performance according to the grade. The release performance is good if the mass increase after dipping is small, and vice versa. The mass of the steel plate before dipping is m1, and the mass increases to m2 after dipping, then the percentage increase of the mass of the steel plate before and after dipping is W=(m2-m1)/m1×100%. When W≤0.1%, the performance is excellent; when 0.1%<W≤0.5%, the performance is good; when W≥0.5%, the performance is poor;

table 3

由表3可以看出，采用本发明制备的脱模剂具有优异的脱模性能。

As can be seen from Table 3, the release agent prepared by the present invention has excellent release performance.

stability test

Storage stability: Let the prepared release agent stand at room temperature for 30 days, and observe whether there is delamination.

Shear stability: After diluting the prepared release agent 145 times, stir with a high-speed stirrer at 3200rpm/min for 15min:

Table 4

由表3可以看出，本发明通过引入制备的复合乳液，能够提高脱模剂的储存稳定性和剪切稳定性。

As can be seen from Table 3, the present invention can improve the storage stability and shear stability of the release agent by introducing the prepared composite emulsion.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. and modifications, the scope of the invention is defined by the equivalents of the appended claims.

Claims (7)

1. A water-based release agent for aluminum alloy die-casting, characterized in that, in parts by weight, comprising: 80-90 parts of solvent, 10-20 parts of composite emulsion, 1-2 parts of emulsifier, 1-1.5 parts of defoaming agent agent, 2-5 parts of phosphate compounds, 1-2 parts of silicone oil. 2. a kind of aluminum alloy die-casting water-based release agent according to claim 1, is characterized in that, comprises 12-16 parts of composite emulsion and 1.2-1.6 part of silicone oil, and wherein, composite emulsion and silicone oil weight ratio are 10: 1. 3. a kind of aluminum alloy die-casting water-based release agent according to claim 2, is characterized in that, the preparation method of described composite emulsion is: The raw material components are mixed together sequentially, and pre-emulsified to obtain a pre-emulsion; Take 10% mass of pre-emulsion, add initiator solution to it, stir for 15 minutes, then gradually add the rest of the pre-emulsion, stir for 2 hours, and finally adjust the pH to 7.5 with ammonia water to obtain the product. 4. A water-based release agent for aluminum alloy die-casting according to claim 3, characterized in that: said raw material components include hydroxyethyl methacrylate, perfluoroalkyl ethyl methacrylate, styrene , butyl acrylate, isobutoxymethyl-acrylamide, acrylic acid, 4-styrene acid, sodium dodecyl diphenyl ether disulfonate, and deionized water. 5. A kind of aluminum alloy die-casting water-based release agent according to claim 2, is characterized in that, described silicone oil is to take octamethylcyclotetrasiloxane, divinyltetramethyldisiloxane as raw material , formed by ring-opening polymerization under the action of acid or base catalyst. 6. A water-based mold release agent for aluminum alloy die-casting according to claim 5, wherein the catalyst is an alkali metal K, Na hydroxide. 7. The preparation method of a water-based release agent for aluminum alloy die-casting according to claim 1, characterized in that: comprising: Mix the emulsifier, phosphate ester compound, and silicone oil together to obtain a mixture; Add compound emulsion, solvent, and defoamer to the mixture in sequence, and mix evenly to obtain a water-based release agent.