KR102704575B1 - Mold release agent for die casting - Google Patents

Abstract

The present invention relates to a water-soluble release agent composition for die casting, and more specifically, it is characterized by containing 50 to 60 wt% of edible vegetable oil, 5 to 10 wt% of fatty acid, 2 to 4 wt% of tertiary amine, and the remainder water. According to the present invention, there are advantages in that the composition has excellent adhesion, release properties, and cooling effect, excellent high-temperature workability, no attachment occurs on the surface of a mold cavity, almost no smoke, and no foul odor, thereby improving the work environment. In addition, it has the advantages of being economical because it is diluted with water and being environmentally friendly because it contains edible vegetable oil as a main component.

Description

{MOLD RELEASE AGENT FOR DIE CASTING}

The present invention relates to a water-soluble release agent composition for die casting, and more specifically, to a water-soluble release agent composition for die casting which contains edible vegetable oil as a main component, has excellent adhesive properties, release properties, and cooling effects, leaves no residue, and is environmentally friendly.

In die casting, a lubricant called a release agent is sprayed after opening the mold to properly separate the product from the mold cavity surface of the die casting machine, thereby forming an oil film on the surface of the mold cavity, and this oil film prevents non-ferrous metal molten metal such as aluminum, magnesium, and zinc from being soldered to the mold cavity, thereby enabling continuous casting.

In the past, these release agents were oil-based, containing solids, powders of graphite or aluminum, or lard that made the machine sticky after use, and were diluted by users with inexpensive solvents such as kerosene and applied.

However, since these release agents contain powder, the work environment is weakened due to the powder flying around the mold during casting, and it is deposited in the mold, requiring frequent cleaning. In addition, oil-based release agents mixed with kerosene with a low flash point have a high risk of fire, make it difficult to automate die casting, and are a cause of low production efficiency because they are applied manually. In addition, since the refining degree of kerosene is low and contains trace components such as sulfur, it has a negative effect on the human body and emits a strong oily odor.

For this reason, water-soluble release agents, which do not pose a fire risk, have been used in place of the past oil-based release agents for automation purposes, and this has continued to this day.

Among the release agents for water-soluble die-casting, silicone-based release agents are used. Representative components of these silicone-based mold casting release agents include dimethylsilicone, alkyl-modified silicone, alkylaralkyl-modified silicone, and alkylester-modified silicone.

Alkyl-modified silicone, alkyl-aralkyl co-modified silicone and alkyl ester co-modified silicone have side chain groups such as alkyl groups, aralkyl groups and ester groups, so they have lubricity, and furthermore, when heated on a mold, they gel to form a strong release film, so it is known that the release property of a release agent using them is improved. However, although these release agents can exhibit release property under low-temperature conditions, when the mold is heated, the silicone component decomposes and volatilizes, so there is a problem that sufficient release property is not obtained. In addition, although the dimethyl silicone is a very stable compound even under high-temperature conditions, it has high heat resistance and does not form a release film as described above even when heated on a mold, so there is a problem that the release property of the obtained release agent is insufficient.

In addition, development is being made to increase the viscosity of organo-modified silicone to improve the adhesion of the release agent to the mold, with the aim of increasing the release property under high-temperature conditions. As representative examples, a release agent using a condensation reaction product of diorganopolysiloxane having a hydrolyzable group in the side chain and a release agent using branched organo-modified silicone crosslinked with organo-modified silicones by a hydrocarbon group or a conjugated diene having double bonds at both terminals have been developed.

However, the former has a problem that since diorganopolysiloxane has a hydrolyzable group, it becomes unstable when used as a mold-casting release agent, and sufficient release properties are not obtained. In the latter case, since the branched organo-modified silicone has a high viscosity, the adhesion of the resulting release agent to the mold is improved, but its release properties are still insufficient, and especially when used as an oil-based mold-casting release agent, the release properties are further reduced.

In addition, most existing silicone release agents have good mold release properties, but they often cause adhesion to the mold, and these substances carbonize at high temperatures, leaving a lot of residual carbon, making them unusable for products requiring a precise surface, and incurring a lot of costs for secondary surface processing.

KR 10-2017-0041497 A KR 10-1993-0009729 A

Accordingly, the purpose of the present invention is to overcome the shortcomings of conventional water-soluble silicone-based release agents, and to provide a water-soluble release agent composition for die casting which has excellent adhesion, release properties and cooling effect, as well as excellent working performance at high temperatures, and does not cause attachment on the surface of a mold cavity.

Another object of the present invention is to provide a water-soluble release agent composition for die casting which enables uniform product production without forming a silicone oil film, protects a mold cavity, and has excellent economic efficiency.

The water-soluble release agent composition for die casting of the present invention to achieve the above-mentioned purpose is characterized by containing 50 to 60 wt% of edible vegetable oil, 5 to 10 wt% of fatty acid, 2 to 4 wt% of tertiary amine, and the remainder of water.

The above edible vegetable oil is at least one of soybean oil, corn oil, grape seed oil, olive oil, coconut oil, cacao oil, palm oil, avocado oil, and sunflower oil, the fatty acid is oleic acid at a molar concentration of 4 to 10, and the tertiary amine is at least one of trimethylamine, dimethylaniline, and N-methylpiperidine.

It is characterized by further containing 1 to 5 wt% of fermented oil.

It is characterized by further containing 1 to 2 wt% of liquid konjac.

According to the present invention, there are advantages in that the adhesiveness, release properties, and cooling effect are excellent, high-temperature workability is excellent, no attachment occurs on the surface of the mold cavity, there is almost no smoke, and there is no foul odor, thereby improving the work environment. In addition, there are advantages in that it is economical because it is diluted with water and used, and it is environmentally friendly because it contains edible vegetable oil as its main ingredient.

Hereinafter, the present invention will be described in detail.

The water-soluble release agent composition for die casting of the present invention is intended to solve various problems of conventional silicone-based water-soluble release agent compositions, and is environmentally friendly by using edible vegetable oil as a main component, and does not generate gas or odor during work, thereby improving the work environment. In addition, it can be used at high temperatures, has excellent release properties and adhesion properties, and has the greatest characteristics of not forming adhesion on the surface of the mold cavity.

The water-soluble release agent composition for die casting of the present invention is an emulsion type water-soluble release agent composition containing 50 to 60 wt% of edible vegetable oil, 5 to 10 wt% of fatty acid, 2 to 4 wt% of tertiary amine, and the remainder of water.

First, the edible vegetable oil is the main component of the release agent composition, and while it provides excellent release and adhesion performance, it does not generate gas or odor when used, thus improving the working environment and has the advantage of being environmentally friendly.

As these vegetable oils, one or more of soybean oil, corn oil, grapeseed oil, olive oil, coconut oil, cacao oil, palm oil, avocado oil, and sunflower oil can be used, and it is more preferable to use oils containing 70% or more of triglycerides of monounsaturated or polyunsaturated C10 to C22 fatty acids, because this is because they are easy to crystallize at low temperatures, thereby further improving release performance. However, the present invention is not limited to the type of these vegetable oils, and it goes without saying that various edible vegetable oils that can be purchased commercially can all be used.

It is preferable that the above vegetable oil be included in the composition at 50 to 60 wt%. If the content is less than 50 wt%, sufficient releasing properties cannot be achieved, and if it exceeds 60 wt%, it becomes excessive and is not economical.

The above fatty acids not only enable the vegetable oil to disperse in water, but also play a role in improving adhesive properties, etc.

Any of animal, vegetable, saturated fatty acids, and unsaturated fatty acids containing at least one double bond and/or triple bond can be used as these fatty acids. In addition, the carbon number is preferably 12 to 24, because if it is out of this range, the dispersibility is poor and the surface properties of the die-casting product are affected. As these fatty acids, one or more of oleic acid, linoleic acid, linolenic acid, arachidonic acid, erucic acid, palmitic acid, and plamitic acid can be used, and most preferably, oleic acid is used at a concentration of 4 to 10 molar.

It is preferable that the above fatty acid be included in the release agent composition at 5 to 10 wt%. If the content is less than 5 wt%, dispersibility and stability deteriorate, and if it exceeds 10 wt%, release property deteriorates.

The above tertiary amine acts as a surfactant together with the above fatty acid to enable the vegetable oil to be dispersed in water, thereby improving the overall properties of the release agent composition.

It is preferable to use at least one of trimethylamine, dimethylaniline, and N-methylpiperidine as the tertiary amine, and trimethylamine is most preferably used.

It is preferable that the above tertiary amine be included in the release agent composition at 2 to 4 wt%. This is because if the content is less than 2 wt%, dispersibility is poor, and if it exceeds 4 wt%, there are problems such as reduced release property.

In addition, the dispersant composition of the present invention may further include one or more additives selected from the group consisting of an emulsifier, a nonionic surfactant, an anti-foaming agent, an antioxidant, and a dispersing agent, but is not limited thereto.

At this time, the amount of the additive to be used is sufficient if it is a level known in the art, and if its type is known and commercially sold, it can be used regardless of its type.

These additives can be used by appropriately adjusting them within the range of 0.1 to 5 wt% in the heterogeneous composition.

And the water is used to disperse the edible vegetable oil, fatty acid and tertiary amine mentioned above to prepare an emulsion type water-soluble release agent composition, and is included as a remainder in the composition.

The water-soluble release agent composition according to the present invention is used by diluting it with a large amount of water. At this time, the dilution amount is 1:100 to 200 volume ratio of the release agent composition and water, which provides excellent sprayability and economy.

In addition, the water-soluble release agent composition according to the present invention has excellent adhesiveness and release properties as described above, and also has an excellent cooling effect. In addition, no residue remains, and since there is no film formation due to silicone oil, uniform product production by die casting is possible, and it effectively protects the mold. In addition, it has the advantages of being easy to work with because there is almost no smoke, improving the work environment because there is no foul odor, and being harmless to the human body and being environmentally friendly.

Meanwhile, it is preferable that the heterogeneous composition according to the present invention further contains fermented oil.

The above fermented oil is manufactured by incubating the edible vegetable oil described above with a Candida genus strain. As the Candida genus strain, Candida bombicola, etc. can be used. At this time, the incubation temperature is not particularly limited, but it is preferably about 15 to 30°C. The reason for using the Candida genus strain in the present invention is that the heterotypic performance is further improved when the Candida genus strain is used than when other strains are used.

The above fermented oil further improves the release performance of the release agent composition, and is preferably included in the range of 1 to 5 wt% in the release agent composition. This is because if the fermented oil is less than 1 wt%, the effect is minimal, and if it exceeds 5 wt%, it is not economical and the adhesion may be relatively reduced.

In addition, it is preferable that the heterogeneous composition of the present invention further contains liquid konjac.

The above liquid konjac also improves the adhesive performance and release performance of the release agent composition and improves high-temperature usability.

The above liquid konjac may be manufactured by a conventionally disclosed method, or it may be sufficient to use a commercially available one. For example, it may be sufficient to manufacture a liquid konjac having low viscosity by dissolving konjac powder in water, treating it with alkali, and treating it with an enzyme.

The above liquid konjac is preferably included in the release agent composition at 1 to 5 wt%. If the content is less than 1 wt%, the effect of improving release properties is minimal, and if it exceeds 5 wt%, the overall physical properties of the release agent composition deteriorate and the surface of the product is affected, so it is included within the above range.

Hereinafter, the present invention will be described in detail through examples.

(Examples 1 to 4)

A homogeneous emulsion composition was prepared by mixing the composition as shown in Table 1 below in a dissolution tank equipped with a mechanical stirrer.

Composition of Examples 1 to 4 division Corn oil Oleic acid (6M) Trimethylamine Corn fermented milk Liquid Konjac water Example 1 50 7 3 - - to 100 Example 2 50 7 3 3 - to 100 Example 3 50 7 3 - 3 to 100 Example 4 50 7 3 3 3 to 100

At this time, the corn fermented milk was manufactured as follows, and the liquid konjac was purchased and used as a commercial product.

For the culture of the spawn, Candida bombicola Y36 was inoculated at a concentration of 1× ¹⁰⁶ cells/ml on the YM medium, a basic medium for yeast microorganisms, and the spawn was cultured for 24 hours under aerobic conditions of 25°C and 150 rpm. Then, 88.76 wt% of corn oil, 1.24 wt% of medium additives (yeast extract 10.47 wt%, KH2PO4 10.47 wt%, _MgSO4 7.33 wt%, _CaCl2 3.14 _wt %, NaCl 0.52 wt%, _NH4Cl 15.71 wt%, _NaNO3 52.36 wt%), and 10 wt% of the spawn culture were mixed and cultured at 25°C and 1vvm at 300 rpm for 96 hours. Then, the medium layer and the oil layer were separated to obtain a fermented oil layer.

(Example 5)

The same procedure as Example 2 was performed, but Bacillus subtilis was cultured and used instead of Candida bombicola Y36.

(Comparative Example 1)

A commercially available silicone-based release agent composition containing methylhydrogen-modified polysiloxane, an allyl monomer, and an emulsifier was prepared.

(Example 1)

The release agent compositions for die casting of the above-mentioned examples and comparative examples were evaluated for release properties, adhesion properties, and paintability according to the following methods.

Disintegration: The lubricating properties of the disintegrant were evaluated by the friction coefficient obtained by testing according to the ring compression method as follows.

The die was 100 mm in diameter × 10 mm in thickness and was made of SKD 61, a hot-work alloy tool steel, and two dies were used for the test. The die was heated to approximately 200°C, and a 10 ml sample diluted 100 times with water was uniformly applied to one side of the die. An aluminum ring test piece (material A5052, outer diameter 54 mm × inner diameter 27 mm × height 18 mm) preheated to approximately 500°C was placed between the surfaces of the two dies, and compressed at a compression ratio of 50% using a 100-ton oil compression machine. The friction coefficient was calculated from the compression ratio and the change in inner diameter after compression, and when the friction coefficient was 0.12 or less, the releasability was evaluated as good.

Adhesion: The sample was diluted 10 times with water, and 10 ml of the diluted release agent was sprayed onto a heated steel plate by an automatic sprayer to observe the adhesion. The steel plate had a diameter of 100 mm and a thickness of 10 mm, and the material was SKD 61, a hot-work alloy tool steel. The steel plate temperatures were 200°C and 400°C, and the spray air pressure was 4 kg/cm ² .

And the adhesion was evaluated according to the following criteria.

A: Thick and evenly attached.

B: Thin and evenly attached.

C: Almost no attachment.

Paintability: A line was drawn with a magic marker on the surface of an aluminum ring test piece that was subjected to a deformation test, and the extent of spreading of the line was evaluated.

And the paintability was evaluated according to the following criteria.

A: The lines are clear and not blurred at all.

B: Ink is observed with clear lines but partially blurred.

C: The lines are blurred and the ink doesn't transfer.

Test Example 1 Results division Heterogeneity
Adhesiveness Dojo Castle 200℃ 400℃ Example 1 0.09 0.13 A A Example 2 0.08 0.10 A A Example 3 0.08 0.11 A A Example 4 0.07 0.09 A A Example 5 0.09 0.12 A A Comparative Example 1 0.10 0.25 B B

As can be confirmed in Table 2 above, it was confirmed that Examples 1 to 5 of the present invention had superior release properties, adhesion properties, and paintability compared to Comparative Example 1.

(Example 2)

The release agent compositions of Examples 1 to 5 were diluted with water in a volume ratio of 1:100 and applied to the moulds of two different die casting machines for aluminum, with a pressure application time of 5 seconds, a mould temperature of 260° C. and a spray pressure of 9-10 bar. The release agent compositions were applied by automatic spraying, followed by die casting of aluminum with 500 recycles. The compositions were automatically stirred before each application.

As a result, all of Examples 1 to 5 allowed easy removal of the cast parts, no degradation of the release agent composition was observed (no smoke or odor), the molds showed no oily residue, and small oily marks on the parts were easily removed by a normal washing step.

Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims (4)

Containing 50 to 60 wt% of edible vegetable oil, 5 to 10 wt% of fatty acid, 2 to 4 wt% of tertiary amine and the remainder of water.
A water-soluble release agent composition for die casting, characterized in that it further contains 1 to 5 wt% of fermented oil.
In the first paragraph,
A water-soluble release agent composition for die casting, characterized in that the edible vegetable oil is at least one of soybean oil, corn oil, grape seed oil, olive oil, coconut oil, cacao oil, palm oil, avocado oil, and sunflower oil, the animal or vegetable fatty acid is oleic acid at a concentration of 4 to 10 molar, and the tertiary amine is at least one of trimethylamine, dimethylaniline, and N-methylpiperidine.
delete In paragraph 1 or 2,
A water-soluble release agent composition for die casting, characterized in that it further contains 1 to 2 wt% of liquid konjac.