A cold box mold release agent with good mold release performance and its preparation method

Abstract

The present invention relates to the technical field of B22C3 / 00, and in particular to a cold box release agent with good demoulding properties and a preparation method thereof. A cold box release agent with good demoulding properties, in parts by weight, is prepared from raw materials including 8-12 parts of ethylene base oil, 0.01-0.5 parts of a catalyst, and 90-100 parts of a solvent. The cold box release agent provided by the present invention has the characteristics of being sprayed once and being reusable for many times, and the reusable times are many, which reduces the labor intensity, improves the performance of the product, is easy to operate, does not stick to sand, has no residue, has high smoothness, and has good demoulding properties, which improves the problems of few demoulding times at low temperatures and low surface flatness of processed products.

Description

Technical Field

[0001] The present invention relates to the technical field of B22C3 / 00, and particularly relates to a cold box release agent with good demolding property and a preparation method thereof. Background Art

[0002] In casting production, the commonly used core-making methods include self-hardening sand, cold box, hot box, and shell core, etc. At present, the cold box core-making process has the characteristics of high efficiency, high dimensional accuracy, and low consumption, and has been gradually widely applied. The commercially available cold box release agents currently on the market have defects such as poor demolding property, few usage times, and easy oil accumulation, and are prone to crystallization at low temperatures, which affects the normal use of cold box release agents in winter.

[0003] Chinese Patent with the patent application number CN201710786250.6 discloses a cold box release agent and a preparation method thereof, and discloses the use of epoxy-modified silicone oil, but does not disclose the technical problem of being able to be used normally multiple times at low temperatures.

[0004] Therefore, providing a cold box release agent with good stability and multiple mold-opening uses at low temperatures is the main technical problem to be solved at present. Summary of the Invention

[0005] To solve the above problems, the present invention provides a cold box release agent with good demolding property. Calculated by weight, the preparation raw materials include 8-12 parts of ethylene base oil, 0.01-0.5 part of catalyst, and 90-100 parts of solvent.

[0006] Preferably, the viscosity of the ethylene base oil at 25 °C is 500-15000 mm 2 / s.

[0007] Preferably, the viscosity of the ethylene base oil at 25 °C is 800-12000 mm 2 / s.

[0008] Preferably, the mass content of vinyl in the ethylene base oil is 0.05-1.1%.

[0009] Preferably, the ethylene base oil is vinyl silicone oil.

[0010] Further, as examples of the vinyl silicone oil, vinyl silicone oil 2#, vinyl silicone oil DELTA-3000, and vinyl silicone oil DELTA-5000 can be cited.

[0011] The manufacturer of the vinyl silicone oil 2# is Hubei Xinsihai Chemical Co., Ltd., and the viscosity of the vinyl silicone oil at 25 °C is 1000-10000 mm 2 / s, with a vinyl content of 0.07%, volatile matter (150 °C, 2 h) ≤ 2%. The manufacturer of the vinyl silicone oil is Hubei Xinsiha Chemical Co., Ltd., and the model is 2#.

[0012] The manufacturer of the vinyl silicone oil DELTA-3000 is Guangzhou Delta Organosilicon Technology Development Co., Ltd. The viscosity of the vinyl silicone oil DELTA-3000 is 3000 mm 2 / s, and the vinyl content is 0.56 - 0.60%.

[0013] The manufacturer of the vinyl silicone oil DELTA-5000 is Guangzhou Delta Organosilicon Technology Development Co., Ltd. The viscosity of the vinyl silicone oil DELTA-5000 is 5000 mm 2 / s, and the vinyl content is 0.45 - 0.50%.

[0014] The inventors found that by using a vinyl silicone oil with a viscosity of 500 - 15000 mm 2 / s at 25 °C, especially a vinyl silicone oil with a viscosity of 800 - 12000 mm 2 / s at 25 °C, and when the mass content of vinyl in the vinyl silicone oil is 0.05 - 1.1%, when mixed with a mixture of tetramethylammonium hydroxide, isooctane, and isooctane, a cold box release agent with good low-temperature resistance can be prepared. During use, spraying the cold box release agent once can perform demolding of multiple products, and there is no need to spray the release agent again in the middle; when the vinyl content in the used vinyl silicone oil is relatively high, it will affect the flexibility of the cold box release agent and reduce the number of demolding uses. The possible reason is that when the vinyl content is relatively high, it will increase the density of the bonding between the vinyl silicone oil molecular chains, reducing the flexibility of the cold box release agent, especially affecting the number of demolding uses at low temperatures and the surface flatness of the product.

[0015] Preferably, the catalyst is a basic organic compound.

[0016] Preferably, the basic organic compound is selected from one or more combinations of tetramethylammonium hydroxide, dodecyltrimethylammonium hydroxide, and platinum-tetramethyldivinyldisiloxane complex.

[0017] Furthermore, the basic organic compound is tetramethylammonium hydroxide.

[0018] Preferably, the solvent is selected from one or more combinations of isooctane, isohexane, isooctane, cyclohexane, and cyclopentane.

[0019] Preferably, the solvent is a mixture of isooctane and isooctane, and the weight ratio of isooctane to isooctane is 1:(1 - 1.5).

[0020] In order to improve the stability of the cold box release agent at low temperatures, the inventors found in experiments that by using a mixture of isooctane and isooctane as the solvent, and when the weight ratio of isooctane to isooctane is 1:(1 - 1.5), the prepared cold box release agent does not show stratification, does not crystallize when used at low temperatures, and has good demoulding properties. The possible reason is that the mixture of isooctane and isooctane as the solvent provides a liquid environment in which the ethylene base oil and the catalyst can be fully mixed and react sufficiently. This is related to the arrangement of methyl groups on the molecular chain segments of isooctane and isooctane, which can fully disperse tetramethylammonium hydroxide and the ethylene base oil evenly for the linking reaction, improving the stability and good demoulding properties of the prepared cold box release agent, and can extend the number of demoulding times. Moreover, there will be no problem that the solvent volatilizes slowly and affects the health of personnel, and the demoulding performance at low temperatures is not affected, with high smoothness.

[0021] The second aspect of the present invention provides a method for preparing a cold box release agent with good demoulding properties, including the following steps:

[0022] Add the ethylene base oil, catalyst, and solvent to a stirring device in sequence, stir, heat up, and keep warm to obtain a cold box release agent with good demoulding properties.

[0023] Preferably, the heating temperature is 60 - 80 °C and the heat preservation is 30 - 60 min.

[0024] The inventors found that when the mixture of vinyl silicone oil, tetramethylammonium hydroxide, isooctane and isooctane is stirred and heated up, and the heating temperature is 60 - 80 °C and the heat preservation is 30 - 60 min, the vinyl silicone oil can be better emulsified with the mixture of isooctane and isooctane, and a linking reaction occurs under the catalytic action of tetramethylammonium hydroxide, so that the prepared cold box release agent does not show stratification and has good demoulding properties.

[0025] Beneficial effects

[0026] 1. In the present invention, by limiting the viscosity of the vinyl silicone oil and the content of vinyl groups, the problems of few demoulding times at low temperatures and low surface flatness of the processed products are improved.

[0027] 2. In the present invention, by limiting the type of solvent used, the stability of the cold box release agent at high and low temperatures is improved, and the problem that the cold box release agent has slow volatility and affects the health of personnel is improved, reducing the pollution to the atmosphere.

[0028] 3. The cold box release agent provided by the present invention has the characteristics of being sprayable once and having a high number of reusable times. With a high number of reusable times, it reduces the labor intensity, improves the product performance, and is easy to operate, non-adhesive to sand, residue-free, with high smoothness and good demoulding property.

[0029] 4. The cold box release agent provided by the present invention has good low-temperature stability, without crystallization or stratification problems at low temperatures. Detailed implementation mode

[0030] Example 1

[0031] A cold box release agent with good demoulding property, calculated by weight, the preparation raw materials include 10 parts of ethylene base oil, 0.05 part of catalyst, and 95 parts of solvent.

[0032] The ethylene base oil is vinyl silicone oil.

[0033] The vinyl silicone oil is purchased from Guangzhou Delta Organosilicon Technology Development Co., Ltd., with the model DELTA-5000.

[0034] The catalyst is tetramethylammonium hydroxide.

[0035] The solvent is a mixture of isooctane and isooctane, and the weight ratio of isooctane to isooctane is 1:1.2.

[0036] The second aspect of this example provides a preparation method of a cold box release agent with good demoulding property, including the following steps:

[0037] Add the ethylene base oil, catalyst, and solvent into the stirring device in sequence for stirring, heating, and heat preservation to obtain a cold box release agent with good demoulding property.

[0038] The heating temperature is up to 70°C and keep warm for 40 min.

[0039] Example 2

[0040] A cold box release agent with good demoulding property, calculated by weight, the preparation raw materials include 8 parts of ethylene base oil, 0.03 part of catalyst, and 90 parts of solvent.

[0041] The ethylene base oil is vinyl silicone oil.

[0042] The vinyl silicone oil is purchased from Guangzhou Delta Organosilicon Technology Development Co., Ltd., with the model DELTA-3000.

[0043] The catalyst is tetramethylammonium hydroxide.

[0044] The solvent is a mixture of isooctane and isooctane, and the weight ratio of isooctane to isooctane is 1:1.

[0045] In the second aspect of this embodiment, a preparation method of a cold box release agent with good demoulding property is provided, including the following steps:

[0046] Add ethylene base oil, catalyst, and solvent into a stirring device in sequence, stir, heat up, and keep warm to obtain a cold box release agent with good demoulding property.

[0047] Heat up to 60 °C and keep warm for 60 min.

[0048] Example 3

[0049] A cold box release agent with good demoulding property, calculated by weight, the raw materials for preparation include 12 parts of ethylene base oil, 0.07 part of catalyst, and 100 parts of solvent.

[0050] The ethylene base oil is vinyl silicone oil.

[0051] The purchasing manufacturer of the vinyl silicone oil is Hubei Xinsihai Chemical Industry Co., Ltd., and the model is 2#.

[0052] The catalyst is tetramethylammonium hydroxide.

[0053] The solvent is a mixture of isooctane and isooctane, and the weight ratio of isooctane to isooctane is 1:1.5.

[0054] In the second aspect of this embodiment, a preparation method of a cold box release agent with good demoulding property is provided, including the following steps:

[0055] Add ethylene base oil, catalyst, and solvent into a stirring device in sequence, stir, heat up, and keep warm to obtain a cold box release agent with good demoulding property.

[0056] Heat up to 80 °C and keep warm for 30 min.

[0057] Example 4

[0058] Example 4 provides a cold box release agent with good demoulding property. The difference from Example 1 is that the vinyl silicone oil used in Example 4 has a viscosity of 3000 mm at 25 °C 2 / s, and the mass content of vinyl is 10%. The purchasing manufacturer of the vinyl silicone oil is Jinjinle Chemical Co., Ltd.

[0059] Example 5

[0060] Example 5 provides a cold box release agent with good demoulding property. The difference from Example 1 is that the solvent in Example 5 does not contain isooctane.

[0061] Example 6

[0062] Example 6 provides a cold box release agent with good demoulding property. The difference from Example 1 is that in Example 6, methyl silicone oil is used to replace vinyl silicone oil, and the viscosity of the methyl silicone oil at 25 °C is 8000 mm 2 / s;

[0063] The manufacturer from which the methyl silicone oil was purchased is Shenzhen Jipeng Silicon Fluoride Materials Co., Ltd., and the model is JP-201.

[0064] Example 7

[0065] Example 7 provides a cold box release agent with good demoulding property. The difference from Example 1 is that in Example 7, the solvent contains 15% by mass of kerosene.

[0066] Performance Testing

[0067] 1. Odor Test

[0068] Volunteers were selected to judge the volatile odor of the cold box release agents prepared in Examples 1-7. A total of 7 groups of volunteers were selected, with 20 volunteers aged 18-40 without rhinitis or other nasal conditions in each group. After spraying the cold box release agents prepared in Examples 1-7 onto the mold for 2 minutes, the volunteers were asked to smell for 5 seconds each, and the results after smelling were recorded. If 98% or more of the volunteers did not smell the volatile odor, it was recorded as A; if more than 90% and less than 98% of the volunteers did not smell the volatile odor, it was recorded as B; if more than 80% and less than or equal to 90% of the volunteers did not smell the volatile odor, it was recorded as C; if more than 60% and less than or equal to 80% of the volunteers did not smell the volatile odor, it was recorded as D.

[0069] 2. Stability Test

[0070] The cold box release agents prepared in Examples 1-7 were placed in an oven at 45 °C for 24 hours, then taken out and placed at -10 °C for 10 hours. After taking them out, the stability state of the cold box release agents was observed, and whether there was any stratification was recorded. The test results are shown in Table 1.

[0071] 3. Spraying Property Test

[0072] The non-stratified cold box release agents prepared in Examples 1-7 were applied to the demoulding of metal parts with dimensions of 30*30*1.5 cm, and the surface uniformity of the processed products after spraying the cold box release agents on the mold surface was recorded. The number of times the metal parts could be continuously processed after one spraying at 0 °C (the number of times the release agent was sprayed once onto the mold, and the metal parts could be continuously processed to prepare metal parts with a flat surface, no sand sticking, and no dimensional defects) was recorded. The test conditions are shown in Table 1.

[0073] Table 1

[0074]

Claims

1. A cold box release agent with good demoulding property, characterized in that, By weight, the raw materials for preparation include 8 - 12 parts of ethylene base oil, 0.01 - 0.5 parts of catalyst, and 90 - 100 parts of solvent; The viscosity of the ethylene base oil at 25 °C is 500 - 15000 mm 2 / s; The mass content of vinyl groups in the ethylene base oil is 0.05 - 1.1%; The catalyst is a basic organic compound; The solvent is a mixture of isoheptane and isooctane, and the weight ratio of isoheptane to isooctane is 1:(1 - 1.5).

2. The cold box release agent with good demoulding property according to claim 1, characterized in that, The viscosity of the ethylene base oil at 25 °C is 800 - 12000 mm 2 / s.

3. The cold box release agent with good demoulding property according to claim 1, characterized in that, The basic organic compound is selected from one or a combination of more of tetramethylammonium hydroxide, dodecyltrimethylammonium hydroxide, and platinum - tetramethyldivinyldisiloxane complex; 4. A preparation method of the cold box release agent with good demoulding property according to any one of claims 1-3, characterized in that, It includes the following steps: Sequentially add the ethylene base oil, catalyst, and solvent into a stirring device, stir, heat up, and keep warm to obtain a cold box release agent with good release property.

5. The preparation method of the cold box release agent with good demoulding property according to claim 4, characterized in that, The heating temperature is 60 - 80°C, and the heat preservation time is 30 - 60 min.

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