Environment-friendly low-temperature wax material and preparation method thereof

Abstract

The invention relates to an environment-friendly low-temperature wax material and a preparation method thereof, and is characterized in that the environment-friendly low-temperature wax material is composed of a main material and an ethylene-vinyl acetate copolymer accounting for 0.4-0.6% of the mass of the main material, and the main material is composed of 50% of 62-64 DEG C paraffin, 45% of 56-58 DEG C paraffin and 5% of polyethylene wax. According to the environment-friendly low-temperature wax material disclosed by the invention, paraffin wax at different temperatures is selected and matched with a proper amount of polyethylene wax and ethylene-vinyl acetate polymer, so that the obtained environment-friendly low-temperature wax material is in a pasty temperature interval and has relatively high softening point, melting point and toughness, and deformation of a wax mold in a processing process is avoided. According to the method, stearic acid is omitted, hydrochloric acid does not need to be added during wax recovery, only water boiling treatment is needed, and the method is environmentally friendly and can be widely applied to the field of precision investment casting.

Description

Technical Field

[0001] The invention belongs to the technical field of precision casting, and in particular relates to an environmentally friendly low-temperature wax material and a preparation method thereof. Background Art

[0002] With the development of modern science and technology, the application of investment casting is becoming more and more extensive. Wax is a key material used in investment casting process, and the quality of wax directly affects the quality of precision castings.

[0003] At present, the domestic low-temperature wax precision casting industry still widely uses low-temperature wax materials prepared with paraffin wax and stearic acid, which are prepared in a 1:1 ratio of paraffin wax and stearic acid. The advantage is the simple preparation process, and the disadvantage is the low softening point, the wax parts are easy to deform, and because the wax contains stearic acid, hydrochloric acid is required for wax recycling, which is not in line with environmental protection policies.

[0004] In view of the above defects, researchers in this field have carried out targeted research, and a technical solution of replacing stearic acid with polyethylene wax and ethylene-vinyl acetate polymer has emerged. For example, CN 116694090A discloses an environmentally friendly low-temperature mold material and a preparation method thereof, comprising the following components by weight: paraffin wax, 75-95 parts, paraffin wax is a C25-30 alkane with short branches, wherein the total degree of substitution of the short branches is 0.3-0.5; polyethylene wax 0.1-5 parts; ethylene-vinyl acetate copolymer 0.2-4 parts; petroleum resin 0.5-8 parts, although it is claimed to be a low-temperature mold material, the melting point is above 70°C, belonging to the category of medium-temperature wax material. CN1123418929A discloses a modulated wax for precision casting wax pattern and a preparation method thereof. The wax for precision casting wax patterns includes, by mass percentage: microcrystalline wax, 42-44 parts; polyethylene wax, 3-5 parts; petroleum resin, 34-36 parts; ethylene-vinyl acetate copolymer, 2-4 parts; and paraffin wax No. 64, 13-17 parts. Its heating melting temperature is 120-140°C, which still does not belong to the category of low-temperature wax. Considering that the production conditions of medium-temperature wax are more stringent than those of low-temperature wax, it is easy to produce dents and has high costs.

[0005] In view of this, it is urgent to invent a kind of environmentally friendly low-temperature wax material. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects in the prior art, provide an environmentally friendly low-temperature wax material, and provide a preparation method thereof.

[0007] To achieve the above object, the technical solution adopted by the present invention is: On the one hand, the present invention provides an environmentally friendly low-temperature wax material, which consists of a main material and ethylene-vinyl acetate copolymer equivalent to 0.4-0.6% of the mass of the main material, wherein the main material consists of 50% of 62-64°C paraffin, 45% of 56-58°C paraffin and 5% of polyethylene wax.

[0008] As a further improvement of the present invention, the specification of the polyethylene wax is PE100 (melting point 100±5°C).

[0009] As a further improvement of the present invention, the specification of the ethylene-vinyl acetate copolymer is 28 / 250.

[0010] Another aspect of the present invention provides a method for preparing the above-mentioned environmentally friendly low-temperature wax material: S1: Melt 62~64℃ paraffin and 56~58℃ paraffin at 120~150℃, and pour into the paste barrel at 80~85℃ after melting; S2: Melt the polyethylene wax at 120-150°C and pour it into the paste barrel of step S1 after melting; S3: Melting the vinyl acetate copolymer at 140-170° C., and pouring it into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 80-85℃ and stir for 6-8h.

[0011] The beneficial effects of adopting the above technical solution are: The present invention selects paraffin wax of different temperatures, and combines appropriate amounts of polyethylene wax and ethylene-vinyl acetate polymer, so that the obtained environmentally friendly low-temperature wax material is in a paste temperature range, and has a high softening point, melting point and toughness, thereby avoiding deformation of the wax mold during processing. The present invention eliminates stearic acid, and does not need to add hydrochloric acid when the wax material is recovered. It only needs to be treated by boiling water. The melting temperature of the obtained wax material is 65-70°C. Compared with the existing medium-temperature wax material, it has low cost, controllable quality, and is environmentally friendly, and can be widely used in the field of precision investment casting. DETAILED DESCRIPTION

[0012] The specific implementation of the present invention is further described below in conjunction with the examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that if there are processes that are not particularly described in detail below, they can be implemented or understood by those skilled in the art with reference to the prior art. If the manufacturer of the reagents or instruments used is not indicated, it is regarded as a conventional product that can be purchased commercially.

[0013] The various raw materials used in this embodiment are described as follows: Example 1 An environmentally friendly low-temperature wax material is prepared by weighing, by weight percentage, 50% of 62°C refined paraffin wax, 45% of 58°C refined paraffin wax and 5% of polyethylene wax PE100 to form a main material, and weighing 0.5% of the total weight of the main material of 28 / 250 ethylene-vinyl acetate polymer for standby use; the preparation method is as follows: S1: Melt 62℃ refined paraffin and 58℃ refined paraffin at 135±2℃, and pour into the paste barrel at 82±2℃ after melting; S2: Melt the polyethylene wax at 135±2°C and pour it into the paste barrel of step S1 after melting; S3: Melt ethylene-vinyl acetate polymer at 160±2°C, and pour into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 82±2℃ and stir for 8h to obtain the paste.

[0014] Example 2 An environmentally friendly low-temperature wax material is prepared by weighing, by weight percentage, 50% of 64°C refined paraffin wax, 45% of 56°C refined paraffin wax and 5% of polyethylene wax PE100 to form a main material, and weighing 0.5% of the total weight of the main material of 28 / 250 ethylene-vinyl acetate polymer for standby use; the preparation method is as follows: S1: Melt 64℃ refined paraffin and 56℃ refined paraffin at 135±2℃, and pour into the paste barrel at 82±2℃ after melting; S2: Melt the polyethylene wax at 135±2°C and pour it into the paste barrel of step S1 after melting; S3: Melt ethylene-vinyl acetate polymer at 160±2°C, and pour into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 82±2℃ and stir for 8h to obtain the paste.

[0015] Example 3 An environmentally friendly low-temperature wax material is prepared by weighing, by weight percentage, 50% of 63°C refined paraffin wax, 45% of 57°C refined paraffin wax and 5% of polyethylene wax PE100 to form a main material, and weighing 0.5% of the total weight of the main material of 28 / 250 ethylene-vinyl acetate polymer for standby use; the preparation method is as follows: S1: Melt 63℃ refined paraffin and 57℃ refined paraffin at 135±2℃, and pour into the paste barrel at 82±2℃ after melting; S2: Melt the polyethylene wax at 135±2°C and pour it into the paste barrel of step S1 after melting; S3: Melt ethylene-vinyl acetate polymer at 160±2°C, and pour into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 82±2℃ and stir for 8h to obtain the paste.

[0016] Comparative Example 1 An environmentally friendly low-temperature wax material is prepared by weighing, by weight percentage, 45% of 62°C refined paraffin wax, 50% of 58°C refined paraffin wax and 5% of polyethylene wax PE100 to form a main material, and weighing 0.5% of the total weight of the main material of 28 / 250 ethylene-vinyl acetate polymer for standby use; the preparation method is as follows: S1: Melt 62℃ refined paraffin and 58℃ refined paraffin at 135±2℃, and pour into the paste barrel at 82±2℃ after melting; S2: Melt the polyethylene wax at 135±2°C and pour it into the paste barrel of step S1 after melting; S3: Melt ethylene-vinyl acetate polymer at 160±2°C, and pour into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 82±2℃ and stir for 8h to obtain the paste.

[0017] Comparative Example 2 An environmentally friendly low-temperature wax material is prepared by weighing, by weight percentage, 48% of 62°C refined paraffin wax, 47% of 58°C refined paraffin wax and 5% of polyethylene wax PE100 to form a main material, and weighing 0.5% of the total weight of the main material of 28 / 250 ethylene-vinyl acetate polymer for standby use; the preparation method is as follows: S1: Melt 62℃ refined paraffin and 58℃ refined paraffin at 135±2℃, and pour into the paste barrel at 82±2℃ after melting; S2: Melt the polyethylene wax at 135±2°C and pour it into the paste barrel of step S1 after melting; S3: Melt ethylene-vinyl acetate polymer at 160±2°C, and pour into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 82±2℃ and stir for 8h to obtain the paste.

[0018] Comparative Example 3 An environmentally friendly low-temperature wax material is prepared by weighing, by weight percentage, 50% of 62°C refined paraffin wax, 45% of 58°C refined paraffin wax and 5% of polyethylene wax PE120 to form a main material, and weighing 0.5% of the total weight of the main material of 28 / 250 ethylene-vinyl acetate polymer for standby use; the preparation method is as follows: S1: Melt 62℃ refined paraffin and 58℃ refined paraffin at 135±2℃, and pour into the paste barrel at 82±2℃ after melting; S2: Melt the polyethylene wax at 135±2°C and pour it into the paste barrel of step S1 after melting; S3: Melt ethylene-vinyl acetate polymer at 160±2°C, and pour into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 82±2℃ and stir for 8h to obtain the paste.

[0019] Comparative Example 4 An environmentally friendly low-temperature wax material is prepared by weighing, by weight percentage, 50% of 62°C refined paraffin wax, 45% of 58°C refined paraffin wax and 5% of polyethylene wax PE100 to form a main material, and weighing 0.5% of the total weight of the main material of 35 / 250 ethylene-vinyl acetate polymer for standby use; the preparation method is as follows: S1: Melt 62℃ refined paraffin and 58℃ refined paraffin at 135±2℃, and pour into the paste barrel at 82±2℃ after melting; S2: Melt the polyethylene wax at 135±2°C and pour it into the paste barrel of step S1 after melting; S3: Melt ethylene-vinyl acetate polymer at 160±2°C, and pour into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 82±2℃ and stir for 8h to obtain the paste.

[0020] Comparative Example 5 An environmentally friendly low-temperature wax material is prepared by weighing, by weight percentage, 50% of 62°C refined paraffin wax, 45% of 58°C refined paraffin wax and 5% of polyethylene wax PE100 to form a main material, and weighing 0.8% of the total weight of the main material of 28 / 250 ethylene-vinyl acetate polymer for standby use; the preparation method is as follows: S1: Melt 62℃ refined paraffin and 58℃ refined paraffin at 135±2℃, and pour into the paste barrel at 82±2℃ after melting; S2: Melt the polyethylene wax at 135±2°C and pour it into the paste barrel of step S1 after melting; S3: Melt ethylene-vinyl acetate polymer at 160±2°C, and pour into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 82±2℃ and stir for 8h to obtain the paste.

[0021] Comparative Example 6 An environmentally friendly low-temperature wax material is prepared by weighing, by weight percentage, 50% of 66°C refined paraffin wax, 45% of 56°C refined paraffin wax and 5% of polyethylene wax PE100 to form a main material, and weighing 0.5% of the total weight of the main material of 28 / 250 ethylene-vinyl acetate polymer for standby use; the preparation method is as follows: S1: Melt 66℃ refined paraffin and 56℃ refined paraffin at 135±2℃, and pour into the paste barrel at 82±2℃ after melting; S2: Melt the polyethylene wax at 135±2°C and pour it into the paste barrel of step S1 after melting; S3: Melt ethylene-vinyl acetate polymer at 160±2°C, and pour into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 82±2℃ and stir for 8h to obtain the paste.

[0022] Comparative Example 7 An environmentally friendly low-temperature wax material is prepared by weighing, by weight percentage, 50% of 64°C refined paraffin wax, 45% of 54°C refined paraffin wax and 5% of polyethylene wax PE100 to form a main material, and weighing 0.5% of the total weight of the main material of 28 / 250 ethylene-vinyl acetate polymer for standby use; the preparation method is as follows: S1: Melt 64℃ refined paraffin and 54℃ refined paraffin at 135±2℃, and pour into the paste barrel at 82±2℃ after melting; S2: Melt the polyethylene wax at 135±2°C and pour it into the paste barrel of step S1 after melting; S3: Melt ethylene-vinyl acetate polymer at 160±2°C, and pour into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 82±2℃ and stir for 8h to obtain the paste.

[0023] Effect example The wax materials for precision investment casting provided by Examples 1-3 and Comparative Examples 1-7 were tested for performance, and the test standards were as follows: softening point: GB / T 14235.1-2018; needle penetration: GB / T 14235.2-2018; flexural strength: GB / T14235.2-2018; ash content: GB / T 14235.1-2018; linear shrinkage: GB / T 14235.1-2018. The results are shown in Table 1: Table 1 Wax properties Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An environmentally friendly low-temperature wax material, characterized in that: The invention comprises a main material and ethylene-vinyl acetate copolymer which is equivalent to 0.4-0.6% of the mass of the main material. The main material comprises 50% of 62-64°C paraffin, 45% of 56-58°C paraffin and 5% of polyethylene wax.

2. The environmentally friendly low-temperature wax material according to claim 1, characterized in that: The specification of the polyethylene wax is PE100.

3. The environmentally friendly low-temperature wax material according to claim 1, characterized in that: The specification of the ethylene-vinyl acetate copolymer is 28 / 250.

4. A method for preparing an environmentally friendly low-temperature wax material according to any one of claims 1 to 3, characterized in that: The following steps are included: S1: Melt 62~64℃ paraffin and 56~58℃ paraffin at 120~150℃, and pour into the paste barrel at 80~85℃ after melting; S2: Melt the polyethylene wax at 120-150°C and pour it into the paste barrel of step S1 after melting; S3: Melt ethylene-vinyl acetate copolymer at 140-170°C, and pour into the paste barrel of step S2 after melting; S4: Keep the materials in the paste barrel at 80-85℃ and stir for 6-8h.

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