Low-temperature powder coating for compressor shell and preparation method of low-temperature powder coating

Abstract

The invention relates to the technical field of powder coatings, in particular to a compressor shell low-temperature powder coating and a preparation method thereof.According to an acrylic acid modified hydroxyl polyester component, by introducing an acrylic resin intermediate, the molecular structure of polyester resin can be optimized, so that the activation energy of curing reaction is reduced, and meanwhile, the low-temperature powder coating has the advantages that the heat resistance is improved; by adding the modified micaceous iron oxide and the modified barium sulfate, the leveling property and the dispersity of the coating can be improved, so that the coating can be quickly and uniformly cured at a relatively low temperature to form a compact coating, and therefore, the coating can be cured at a relatively low temperature, the energy consumption is reduced, and the production cost is reduced; meanwhile, adverse effects, such as deformation and strength reduction, caused by high temperature on compressor shell materials are avoided; secondly, the acrylic acid modified hydroxyl polyester component can react with the curing agent to form a three-dimensional network structure, so that good hardness and adhesive force are provided for the coating.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of powder coating, in particular to a low-temperature powder coating for compressor shell and a preparation method thereof. BACKGROUND

[0002] As the core component of refrigeration, air conditioning and other systems, the shell of the compressor is easily affected by corrosion, wear and mechanical impact when exposed to complex environments for a long time, resulting in performance degradation and shortened service life. Although the traditional solvent-based coating can provide certain protection, it has the problem of high volatile organic compound emissions, which does not meet the requirements of environmental protection regulations, and the curing temperature is relatively high, which is easy to cause thermal deformation or performance degradation of the compressor shell material.

[0003] The existing low-temperature powder coating has deficiencies in corrosion resistance, mechanical strength and low-temperature curing efficiency, and it is difficult to meet the long-term protection needs of the compressor shell under harsh working conditions. For example, some low-temperature curing coatings have poor adhesion and are prone to peeling due to incomplete curing. Some modified fillers have poor compatibility with the matrix, which affects the density and corrosion resistance of the coating. Therefore, it is a technical problem to be solved in the field to develop a powder coating that has environmental protection, low-temperature curing performance and excellent protection effect. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the present application provides a low-temperature powder coating for compressor shell and a preparation method thereof, which can effectively solve the problem of insufficient performance of the powder coating of the prior art.

[0005] To achieve the above object, the present application is realized by the following technical scheme: A low-temperature powder coating for compressor shell, which is composed of the following raw materials: acrylic acid modified hydroxyl polyester component, modified mica iron oxide, modified barium sulfate, curing agent, titanium white, leveling agent and benzoin. The acrylic acid modified hydroxyl polyester component is prepared using acrylic resin intermediate, terephthalic acid and neopentyl glycol as main raw materials; The modified mica iron oxide is prepared by first coating with silicon dioxide and then modifying with silane coupling agent; The modified barium sulfate is prepared by modifying barium sulfate with silane coupling agent.

[0006] Further, the preparation method of the acrylic resin intermediate is as follows: S201, weigh 450-500g of methyl methacrylate, 10-50g of lauryl methacrylate, 60-150g of butyl acrylate, 30-150g of glycidyl methacrylate, 70-90g of styrene, 8-14g of dodecyl mercaptan and 15-25g of tert-butyl peroxyacetate, and mix them. After mixing and stirring, the obtained mixture is marked as mixed component; S202, after putting 500-600g xylene into the reaction kettle, nitrogen was introduced and the temperature was raised to 120℃, then the mixed components were added dropwise within 3h, 2-5g tert-butyl hydroperoxide was added after dropping, and the temperature was kept for 4h, vacuum treatment was carried out after the temperature was raised to 150℃, and the material was discharged after the vacuum was released. The obtained is the acrylic resin intermediate.

[0007] Further, the method of mixing and stirring in S201 is stirring at a stirring speed of 400-500r / min for 30min, and the method of vacuum treatment in S202 is vacuuming at a vacuum degree of-0.098MPa for 3h.

[0008] Further, the preparation method of the acrylic modified hydroxyl polyester component is: S401, 200-400g of neopentyl glycol, 40-80g of butanediol and 30-60g of ethyl butyl propylene glycol were added into the reaction kettle, nitrogen was introduced, and the temperature was raised to 160℃ under stirring. After complete melting, the obtained was marked as the molten component; S402, 10-60g of trimethylolpropane, 300-500g of terephthalic acid, 80-150g of isophthalic acid, 35-100g of adipic acid, 10-50g of pyromellitic anhydride and 5-10g of monobutyl tin oxide were added into the molten component, the temperature was raised to 250℃ and kept for 2h, the temperature was lowered to 210℃ after the acid value was 12-16mgKOH / g, and the obtained was marked as the reaction component; S403, 50-200g of acrylic resin intermediate was added into the reaction component, the acid value was tested after reacting at a temperature of 210℃ for 2h, vacuum treatment was carried out after the acid value was 7-10mgKOH / g, until the resin sample acid value was 1-4mgKOH / g and the hydroxyl value was 20-25mgKOH / g, then the vacuum was released and the material was discharged, and the obtained was the acrylic modified hydroxyl polyester component.

[0009] Further, the stirring speed of the stirring condition in S401 is 300-500r / min, and the method of vacuum treatment in S403 is vacuuming at a vacuum degree of-0.098MPa for 3h.

[0010] Further, the preparation method of the modified mica iron oxide is: S601, 0.1-0.2g of tetraethyl orthosilicate and 0.5-0.6g of silane coupling agent A-151 were added into 50-60mL of anhydrous ethanol, and the obtained was marked as the dropping component after being uniformly dispersed; S602, 2-3g of mica iron oxide and 50-80mL of anhydrous ethanol are weighed into a flask, stirring and dispersing under nitrogen protection, adding the components dropwise, adjusting the pH value to 8-9 with ammonia water, reacting at 40 DEG C for 6h, then removing the filtrate by vacuum filtration, washing the obtained product with anhydrous ethanol for 3 times, and then drying treatment, and the obtained product is modified mica iron oxide.

[0011] Further, the uniform dispersion method in S601 is stirring at a stirring speed of 400r / min for 10min, the drop speed in S602 is 1 drop / s, and the drying treatment method in S602 is drying at a temperature of 68 DEG C until the weight is constant.

[0012] Further, the preparation method of the modified barium sulfate is: 5g of silane coupling agent KH-550, 85g of anhydrous ethanol and 15g of deionized water are mixed, stirred at a stirring speed of 500r / min for 10min, then 1mol / L of acetic acid is added dropwise to adjust the pH value to 4.5, and then stirred for 1h, then sprayed on the surface of barium sulfate in a spray form according to a solid-liquid ratio of 2:1, and then dried at a temperature of 120 DEG C for 2h, and the obtained product is modified barium sulfate.

[0013] A preparation method of a compressor shell low-temperature powder coating, the preparation method of the compressor shell low-temperature powder coating is: 500 parts of acrylic modified hydroxyl polyester component, 40-50 parts of modified mica iron oxide, 150-170 parts of modified barium sulfate, 60-70 parts of curing agent, 90-110 parts of titanium white, 5-6 parts of leveling agent and 3-4 parts of benzoin are weighed according to weight parts, mixed, melt blended, extruded and crushed, sieved, and the obtained product is a compressor shell low-temperature powder coating.

[0014] Further, in the preparation method of the compressor shell low-temperature powder coating, the mesh number of sieving is 200 mesh.

[0015] The present application provides a compressor shell low-temperature powder coating and a preparation method thereof, compared with the prior art, the present application has the following beneficial effects: 1. The acrylic-modified hydroxyl polyester component in this invention optimizes the molecular structure of the polyester resin by introducing an acrylic resin intermediate, thereby reducing the activation energy of the curing reaction. Simultaneously, the addition of modified mica iron oxide and modified barium sulfate improves the leveling and dispersibility of the coating, enabling rapid and uniform curing at lower temperatures to form a dense coating. This allows for curing at relatively low temperatures, reducing energy consumption and production costs, while avoiding adverse effects on the compressor housing material caused by high temperatures, such as deformation and reduced strength. Furthermore, the acrylic-modified hydroxyl polyester component reacts with the curing agent to form a three-dimensional network structure, providing good hardness and adhesion for the coating.

[0016] 2. The modified mica iron oxide and modified barium sulfate in this invention, as fillers, can be uniformly dispersed in the polyester matrix, thereby enhancing the strength and toughness of the coating and enabling it to withstand certain external impacts and friction. After being coated with silica and modified with a silane coupling agent, the surface properties of the modified mica iron oxide are improved, and it can form a dense shielding layer in the coating, thereby effectively blocking the penetration of corrosive media. After being modified with a silane coupling agent, the modified barium sulfate can improve its compatibility with the polyester matrix, thereby enhancing the density and corrosion resistance of the coating. In addition, the addition of titanium dioxide can further improve the hiding power and weather resistance of the coating, helping to resist the erosion of the external environment. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] The present invention will be further described below with reference to embodiments.

[0019] Example 1

[0020] This embodiment of a low-temperature powder coating for a compressor housing is composed of the following raw materials: acrylic modified hydroxyl polyester component, modified mica iron oxide, modified barium sulfate, curing agent, titanium dioxide, leveling agent and benzoin; The acrylic-modified hydroxyl polyester component is prepared from acrylic resin intermediates, terephthalic acid, and neopentyl glycol as the main raw materials. The preparation method of acrylic resin intermediate is as follows: S201, 450 g of methyl methacrylate, 10 g of lauryl methacrylate, 60 g of butyl acrylate, 30 g of glycidyl methacrylate, 70 g of styrene, 8 g of dodecyl mercaptan and 15 g of tert-amyl peroxyacetate were weighed and mixed, and then stirred at a stirring speed of 400 r / min for 30 min, and the obtained product was recorded as a mixed component; S202, 500 g of dimethylbenzene was put into a reaction kettle, and then nitrogen was introduced and the temperature was raised to 120℃, then the mixed component was added dropwise within 3 h, 2 g of tert-amyl peroxyacetate was added after the dropping was completed, and the temperature was kept for 4 h, then the temperature was raised to 150℃, and vacuum was drawn at a vacuum degree of-0.098 MPa for 3 h, then the vacuum was released, and the product was discharged, and the obtained product was an acrylic resin intermediate.

[0021] The preparation method of the acrylic modified hydroxyl polyester component is as follows: S401, 200 g of neopentyl glycol, 40 g of butanediol and 30 g of ethyl butyl propylene glycol were added into a reaction kettle, nitrogen was introduced, and then the temperature was raised to 160℃ under stirring at a stirring speed of 300 r / min, and then the obtained product was recorded as a molten component; S402, 10 g of trimethylolpropane, 300 g of terephthalic acid, 80 g of isophthalic acid, 35 g of adipic acid, 10 g of pyromellitic anhydride and 5 g of monobutyl tin oxide were added into the molten component, the temperature was raised to 250℃, and then kept for 2 h, then the temperature was lowered to 210℃ after the acid value was 12 mgKOH / g, and the obtained product was recorded as a reaction component; S403, 50 g of the acrylic resin intermediate was added into the reaction component, and then reacted at a temperature of 210℃ for 2 h, and then the acid value was tested, and then vacuum was drawn at a vacuum degree of-0.098 MPa for 3 h after the acid value was 7 mgKOH / g, until the resin sample acid value was 1 mgKOH / g and the hydroxyl value was 20 mgKOH / g, then the vacuum was released and the product was discharged, and the obtained product was an acrylic modified hydroxyl polyester component.

[0022] The modified mica iron oxide was prepared by coating with silicon dioxide and then modified by a silane coupling agent, and the specific preparation method was as follows: S601, 0.1 g of tetraethyl orthosilicate and 0.5 g of silane coupling agent A-151 were added into 50 mL of anhydrous ethanol, and then stirred at a stirring speed of 400 r / min for 10 min, and the obtained product was recorded as a dropping component; S602, 2 g of mica iron oxide and 50 mL of anhydrous ethanol were poured into a flask, and then stirred and dispersed under nitrogen protection, and then the dropping component was added dropwise at a dropping speed of 1 drop / s, and then the pH value was adjusted to 8 with ammonia water, and then reacted at a temperature of 40℃ for 6 h, and then the filtrate was removed by vacuum filtration, and then the obtained product was washed with anhydrous ethanol for 3 times, and then dried at a temperature of 68℃ until the weight was constant, and the obtained product was a modified mica iron oxide.

[0023] The modified barium sulfate is prepared by modifying barium sulfate with a silane coupling agent, and the specific preparation method is as follows: 5g of silane coupling agent KH-550, 85g of anhydrous ethanol and 15g of deionized water are weighed and mixed, stirred at a stirring speed of 500r / min for 10min, then 1mol / L of acetic acid is added dropwise to adjust the pH value to 4.5, and then stirred for 1h, then sprayed on the surface of barium sulfate in the form of spray at a liquid ratio of 2:1, dried at a temperature of 120℃ for 2h, and then the obtained modified barium sulfate is obtained.

[0024] A preparation method of a compressor shell low-temperature powder coating, the preparation method of the compressor shell low-temperature powder coating is as follows: 500 parts of an acrylic modified hydroxyl polyester component, 40 parts of modified mica iron oxide, 150 parts of modified barium sulfate, 60 parts of a curing agent, 90 parts of titanium white powder, 5 parts of a leveling agent and 3 parts of benzoin are weighed and mixed according to weight parts, melt blended, extruded and crushed, and then sieved through a 200 mesh sieve, and the obtained is the compressor shell low-temperature powder coating.

[0025] Example 2

[0026] The compressor shell low-temperature powder coating of the present embodiment is composed of the following raw materials: an acrylic modified hydroxyl polyester component, modified mica iron oxide, modified barium sulfate, a curing agent, titanium white powder, a leveling agent and benzoin. The acrylic modified hydroxyl polyester component is prepared with acrylic resin intermediate, terephthalic acid and neopentyl glycol as main raw materials. The preparation method of the acrylic resin intermediate is as follows: S201, 500g of methyl methacrylate, 50g of lauryl methacrylate, 150g of butyl acrylate, 150g of glycidyl methacrylate, 90g of styrene, 14g of dodecyl mercaptan and 25g of tert-amyl peroxy acetate are weighed and mixed, stirred at a stirring speed of 500r / min for 30min, and then the obtained is denoted as a mixed component; S202, 600g of dimethylbenzene is put into a reaction kettle, nitrogen is introduced and the temperature is raised to 120℃, then the mixed component is added dropwise within 3h, 5g of tert-amyl peroxy acetate is added after the dropwise addition is completed, and the temperature is kept for 4h, then the temperature is raised to 150℃, a vacuum degree of-0.098MPa is maintained for 3h, and then the vacuum is released and the material is discharged, and the obtained is the acrylic resin intermediate.

[0027] The preparation method of the acrylic modified hydroxyl polyester component is as follows: S401, 400g of neopentyl glycol, 80g of butanediol and 60g of ethyl butyl propylene glycol are added into a reaction kettle, nitrogen is introduced, and the temperature is raised to 160℃ under stirring at a stirring speed of 500r / min, and then the obtained is denoted as a molten component after complete melting; S402, 60 g of trimethylolpropane, 500 g of terephthalic acid, 150 g of isophthalic acid, 100 g of adipic acid, 50 g of pyromellitic dianhydride and 10 g of monobutyl tin oxide are added to the molten component, heated to 250 DEG C and kept for 2 h, and after the acid value is 16 mgKOH / g, the temperature is lowered to 210 DEG C, and the obtained is denoted as the reaction component; S403, 200 g of acrylic resin intermediate is added to the reaction component, and after reaction at a temperature of 210 DEG C for 2 h, the acid value is tested, and after the acid value is 10 mgKOH / g, vacuum is drawn at a vacuum degree of -0.098 MPa for 3 h until the resin sample acid value is 4 mgKOH / g and the hydroxyl value is 25 mgKOH / g, then the vacuum is released and discharged, and the obtained is the acrylic modified hydroxyl polyester component.

[0028] The modified mica iron oxide is prepared by coating with silicon dioxide and then modified by silane coupling agent, and the specific preparation method is as follows: S601, 0.2 g of tetraethyl orthosilicate and 0.6 g of silane coupling agent A-151 are added to 60 mL of anhydrous ethanol, stirred at a stirring speed of 400 r / min for 10 min, and then denoted as the dropping component; S602, 3 g of mica iron oxide and 80 mL of anhydrous ethanol are weighed into a flask, stirred and dispersed under nitrogen protection, and then the dropping component is added at a dropping speed of 1 drop / s, and the pH value is adjusted to 9 with ammonia water, and then reacted at a temperature of 40 DEG C for 6 h, and then vacuum filtered to remove the filtrate, and then the obtained product is washed with anhydrous ethanol for 3 times, and then dried at a temperature of 68 DEG C until the weight is constant, and then the obtained is the modified mica iron oxide.

[0029] The modified barium sulfate is prepared by modifying barium sulfate with silane coupling agent, and the specific preparation method is as follows: 5 g of silane coupling agent KH-550, 85 g of anhydrous ethanol and 15 g of deionized water are mixed, stirred at a stirring speed of 500 r / min for 10 min, then 1 mol / L acetic acid is added to adjust the pH value to 4.5, and then stirred for 1 h, and then sprayed on the surface of barium sulfate in the form of spray at a liquid ratio of 2:1, and then dried at a temperature of 120 DEG C for 2 h, and then the obtained is the modified barium sulfate.

[0030] A preparation method of a compressor shell low-temperature powder coating, the preparation method of the compressor shell low-temperature powder coating is as follows: 500 parts of acrylic modified hydroxyl polyester component, 50 parts of modified mica iron oxide, 170 parts of modified barium sulfate, 70 parts of curing agent, 110 parts of titanium white, 6 parts of leveling agent and 4 parts of benzoin are weighed according to weight parts, mixed, melt blended, extruded and pulverized, and then screened through a 200 mesh screen, and then the obtained is the compressor shell low-temperature powder coating.

[0031] Example 3

[0032] The low-temperature powder coating of the compressor housing of the embodiment is composed of an acrylic modified hydroxyl polyester component, modified mica iron oxide, modified barium sulfate, a curing agent, titanium white, a leveling agent, and benzoin. The acrylic modified hydroxyl polyester component is prepared from an acrylic resin intermediate, terephthalic acid, and neopentyl glycol as main raw materials. The preparation method of the acrylic resin intermediate is as follows: S201, 480 g of methyl methacrylate, 30 g of lauryl methacrylate, 100 g of butyl acrylate, 80 g of glycidyl methacrylate, 80 g of styrene, 11 g of dodecyl mercaptan, and 20 g of t-amyl peroxy acetate are mixed, and the obtained mixture is stirred at a stirring speed of 500 r / min for 30 min and is recorded as a mixed component; S202, 600 g of dimethylbenzene is put into a reaction kettle, nitrogen is introduced, and the temperature is raised to 120℃, then the mixed component is added dropwise within 3 h, 4 g of t-amyl peroxy acetate is added after the dropping is completed, and the temperature is kept for 4 h, the temperature is raised to 150℃, vacuum is drawn at a vacuum degree of -0.098 MPa for 3 h, the vacuum is released after the discharge, and the obtained product is the acrylic resin intermediate.

[0033] The preparation method of the acrylic modified hydroxyl polyester component is as follows: S401, 300 g of neopentyl glycol, 60 g of butanediol, and 45 g of ethyl butyl propylene glycol are added into a reaction kettle, nitrogen is introduced, and the temperature is raised to 160℃ under the stirring condition of a stirring speed of 400 r / min, the obtained product is recorded as a molten component after complete melting; S402, 35 g of trimethylolpropane, 400 g of terephthalic acid, 110 g of isophthalic acid, 65 g of adipic acid, 30 g of pyromellitic anhydride, and 8 g of monobutyl tin oxide are added into the molten component, the temperature is raised to 250℃, and kept for 2 h, the temperature is lowered to 210℃ after the acid value is 14 mgKOH / g, and the obtained product is recorded as a reaction component; S403, 120 g of the acrylic resin intermediate is added into the reaction component, the reaction is carried out at a temperature of 210℃ for 2 h, the acid value is tested, vacuum is drawn at a vacuum degree of -0.098 MPa for 3 h after the acid value is 8 mgKOH / g, the vacuum is released after the resin sample acid value is 3 mgKOH / g and the hydroxyl value is 22 mgKOH / g, and the obtained product is discharged, which is the acrylic modified hydroxyl polyester component.

[0034] The modified mica iron oxide is prepared by coating with silicon dioxide and then modifying with a silane coupling agent, and the specific preparation method is as follows: S601, 0.2 g of tetraethyl orthosilicate and 0.6 g of silane coupling agent A-151 are added into 55 mL of anhydrous ethanol, stirred at a stirring speed of 400 r / min for 10 min, and recorded as a dropping component; S602. Weigh 3g of mica iron oxide and 70mL of anhydrous ethanol into a flask. Stir and disperse the mixture under nitrogen protection. Add the components dropwise at a rate of 1 drop / s. Adjust the pH to 9 with ammonia. React at 40℃ for 6 hours. Remove the filtrate by vacuum filtration. Wash the obtained product three times with anhydrous ethanol and dry it at 68℃ to constant weight. The obtained product is modified mica iron oxide.

[0035] Modified barium sulfate is prepared by modifying barium sulfate with a silane coupling agent. The specific preparation method is as follows: Weigh out 5g of silane coupling agent KH-550, 85g of anhydrous ethanol and 15g of deionized water and mix them. Stir at 500r / min for 10min, then add 1mol / L acetic acid to adjust the pH to 4.5. Continue stirring for 1h, then spray the mixture onto the surface of barium sulfate at a material-to-liquid ratio of 2:1. Dry the mixture at 120℃ for 2h to obtain modified barium sulfate.

[0036] A method for preparing a low-temperature powder coating for a compressor housing, the method comprising: Weigh out 500 parts by weight of acrylic modified hydroxyl polyester component, 45 parts by weight of modified mica iron oxide, 160 parts by weight of modified barium sulfate, 65 parts by weight of curing agent, 100 parts by weight of titanium dioxide, 6 parts by weight of leveling agent and 4 parts by weight of benzoin, mix them, melt and blend them, then extrude and crush them, and pass them through a 200-mesh sieve. The result is the low-temperature powder coating for compressor housing.

[0037] Comparative Example 1 The low-temperature powder coating for compressor housing and its preparation method provided in this comparative example are largely the same as those in Example 1, except that the acrylic-modified hydroxyl polyester component in Example 1 is replaced with polyurethane in this comparative example.

[0038] Comparative Example 2 The low-temperature powder coating for compressor housing and its preparation method provided in this comparative example are generally the same as those in Example 1. The main difference is that the modified mica iron oxide in Example 1 is replaced with unmodified mica iron oxide in this comparative example.

[0039] Comparative Example 3 The low-temperature powder coating for compressor housing and its preparation method provided in this comparative example are largely the same as those in Example 1. The main difference is that the modified barium sulfate in Example 1 is replaced with unmodified barium sulfate in this comparative example.

[0040] Performance testing The compressor shell low-temperature powder coatings prepared in Examples 1-3 and Comparative Examples 1-3 are respectively marked as Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2 and Comparative Example 3, and the performances of Examples 1-3 and Comparative Examples 1-3 are detected, and the obtained data are recorded in the following table.

[0041] It can be seen from the data in the above table that the impact strength and acid and alkali corrosion resistance of the compressor shell low-temperature powder coatings in Examples 1-3 are obviously superior to those of Comparative Examples 1-3, which indicates that using the acrylic modified hydroxyl polyester component, modified mica iron oxide and modified barium sulfate as raw materials in the preparation of the compressor shell low-temperature powder coating can make the prepared compressor shell low-temperature powder coating have more excellent performance.

[0042] It should be noted that, in this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0043] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for part of the technical features; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A low-temperature powder coating for a compressor housing, characterized in that, It is composed of the following raw materials: acrylic modified hydroxyl polyester component, modified mica iron oxide, modified barium sulfate, curing agent, titanium dioxide, leveling agent and benzoin; The acrylic-modified hydroxyl polyester component is prepared using acrylic resin intermediates, terephthalic acid, and neopentyl glycol as main raw materials. The modified mica iron oxide is prepared by first coating it with silica and then modifying it with a silane coupling agent; The modified barium sulfate is prepared by modifying barium sulfate with a silane coupling agent.

2. The low-temperature powder coating for a compressor housing according to claim 1, characterized in that, The preparation method of the acrylic resin intermediate is as follows: S201. Weigh 450-500g of methyl methacrylate, 10-50g of lauryl methacrylate, 60-150g of butyl acrylate, 30-150g of glycidyl methacrylate, 70-90g of styrene, 8-14g of dodecyl mercaptan and 15-25g of tert-amyl acetate peroxide and mix them. The mixture obtained after stirring is called the mixed component. S202. After adding 500-600g of xylene into the reactor, nitrogen gas is introduced and the temperature is raised to 120℃. Then, the mixed components are added dropwise over 3 hours. After the addition is complete, 2-5g of tert-amyl acetate peroxide is added and the temperature is maintained for 4 hours. After raising the temperature to 150℃, a vacuum treatment is performed. After the vacuum is released, the material is discharged. The resulting product is the acrylic resin intermediate.

3. The low-temperature powder coating for a compressor housing according to claim 2, characterized in that, The mixing method in S201 is to stir at a stirring speed of 400-500 r / min for 30 min, and the vacuum treatment method in S202 is to vacuum at a vacuum degree of -0.098 MPa for 3 h.

4. The low-temperature powder coating for a compressor housing according to claim 1, characterized in that, The preparation method of the acrylic-modified hydroxyl polyester component is as follows: S401. Add 200-400g neopentyl glycol, 40-80g butanediol and 30-60g ethyl butyl propylene glycol to the reactor. After purging with nitrogen, heat to 160℃ under stirring. The result after complete melting is recorded as the molten component. S402. Add 10-60g of trimethylolpropane, 300-500g of terephthalic acid, 80-150g of isophthalic acid, 35-100g of adipic acid, 10-50g of pyromellitic anhydride and 5-10g of monobutyltin oxide to the molten component. Heat to 250℃ and hold for 2 hours. When the acid value is 12-16mgKOH / g, cool to 210℃. The result is recorded as the reaction component. S403. Add 50-200g of acrylic resin intermediate to the reaction components, react at 210℃ for 2 hours, and then test the acid value. When the acid value is 7-10mgKOH / g, vacuum treatment is performed until the acid value of the resin sample is 1-4mgKOH / g and the hydroxyl value is 20-25mgKOH / g. Then the vacuum is released and the material is discharged. The result is the acrylic modified hydroxyl polyester component.

5. The low-temperature powder coating for a compressor housing according to claim 4, characterized in that, The stirring speed in S401 is 300-500 r / min, and the vacuum treatment method in S403 is to evacuate at a vacuum level of -0.098 MPa for 3 hours.

6. The low-temperature powder coating for a compressor housing according to claim 1, characterized in that, The method for preparing the modified mica iron oxide is as follows: S601. Add 0.1-0.2g of tetraethyl orthosilicate and 0.5-0.6g of silane coupling agent A-151 to 50-60mL of anhydrous ethanol, disperse evenly, and record as the dropwise component; S602. Weigh 2-3g of mica iron oxide and 50-80mL of anhydrous ethanol into a flask. Stir and disperse the mixture under nitrogen protection. After adding the components dropwise, adjust the pH value to 8-9 with ammonia. React at 40℃ for 6 hours, then remove the filtrate by vacuum filtration. Wash the obtained product three times with anhydrous ethanol and then dry it. The result is modified mica iron oxide.

7. The low-temperature powder coating for a compressor housing according to claim 6, characterized in that, The method for uniform dispersion in S601 is to stir at a stirring speed of 400 r / min for 10 min. The dropping rate in S602 is 1 drop / s. The drying method in S602 is to dry at a temperature of 68℃ until constant weight.

8. The low-temperature powder coating for a compressor housing according to claim 1, characterized in that, The method for preparing the modified barium sulfate is as follows: Weigh out 5g of silane coupling agent KH-550, 85g of anhydrous ethanol and 15g of deionized water and mix them. Stir at 500r / min for 10min, then add 1mol / L acetic acid to adjust the pH to 4.

5. Continue stirring for 1h, then spray the mixture onto the surface of barium sulfate at a material-to-liquid ratio of 2:

1. Dry the mixture at 120℃ for 2h to obtain modified barium sulfate.

9. A method for preparing a low-temperature powder coating for a compressor housing according to any one of claims 1-8, characterized in that, The method for preparing the low-temperature powder coating for the compressor housing is as follows: Weigh out 500 parts by weight of acrylic modified hydroxyl polyester component, 40-50 parts of modified mica iron oxide, 150-170 parts of modified barium sulfate, 60-70 parts of curing agent, 90-110 parts of titanium dioxide, 5-6 parts of leveling agent and 3-4 parts of benzoin, mix them, melt and blend them, then extrude and crush them. The result after sieving is the low-temperature powder coating for compressor housing.

10. The method for preparing a low-temperature powder coating for a compressor housing according to claim 9, characterized in that, In the preparation method of low-temperature powder coating for compressor housing, the sieve mesh size is 200 mesh.

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