Polypropylene composition resistant to electroplating chemical liquid as well as preparation method and application of polypropylene composition

Abstract

The invention belongs to the technical field of high polymer materials, and discloses an electroplating chemical liquid resistant polypropylene composition as well as a preparation method and application thereof. The polypropylene composition comprises polypropylene resin, polyethylene wax, an amide lubricant, a glyceride lubricant, a nucleating agent and glass fibers, the isotacticity of the polypropylene resin is larger than or equal to 97.5%, and the nucleating agent is at least one of carboxylic acid metal salt or organic phosphoric acid metal salt. According to the polypropylene composition provided by the invention, the lubricant, the nucleating agent of a specific type and the optional glass fiber are added into the polypropylene with specific isotacticity for comprehensive modification, so that the obtained polypropylene composition not only keeps good mechanical properties, but also has the advantage of resistance to electroplating chemical liquid.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a polypropylene composition resistant to electroplating chemical liquid, a preparation method and application thereof. Background Art

[0002] Polypropylene (PP) has the advantages of low density, easy processing and excellent mechanical properties. It has been widely used in the automotive industry, home appliances and machinery.

[0003] In the electroplating industry, when electroplating aluminum alloys, magnesium alloys, copper alloys, titanium alloys and other original parts, in order to increase the efficiency of electroplating, large quantities of original parts are usually gathered together, fixed with brackets or trays, and then placed in the electroplating tank for batch continuous production. Finally, the brackets or trays are opened to take out the electroplated parts. During this process, the brackets or trays must not damage the parts, participate in the electroplating reaction, and affect the electroplating effect of the parts. If a metal bracket or tray is used, the poor chemical resistance of the metal will lead to a short service life, and it is easy to scratch the parts and affect the electroplating effect; if a plastic bracket or tray is selected, the chemical resistance of the material and the impact on the electroplating effect during the electroplating process must also be considered. In actual use, the tray made of ordinary polypropylene material also has problems of whitening, stratification, and different color spots on the surface of the electroplated parts after the chemical electroplating process.

[0004] The prior art discloses a corrosion-resistant glass fiber reinforced polypropylene material, which uses glass fiber and sorbitol nucleating agents to improve the product's impact strength, tensile strength, mechanical properties and heat resistance, but does not have data on improving the bending modulus. It only studies the corrosion resistance of polypropylene materials in ethylene glycol, covers a relatively small number of material types, and limits the application scope of the material.

[0005] Therefore, developing a polypropylene composition having both good mechanical properties and resistance to electroplating chemical solutions has important research significance and application value. Summary of the invention

[0006] In order to solve the technical problem that the polypropylene material in the prior art cannot have both good mechanical properties and resistance to electroplating chemical liquid, the present invention provides a polypropylene composition resistant to electroplating chemical liquid. The polypropylene composition resistant to electroplating chemical liquid provided by the present invention is comprehensively modified by adding PE wax, amide lubricant, glyceride lubricant and a specific type of nucleating agent to a specific isotactic polypropylene matrix material, so that the obtained polypropylene composite material not only maintains good mechanical properties, but also has good resistance to electroplating chemical liquid.

[0007] Another object of the present invention is to provide a method for preparing the polypropylene composition resistant to electroplating chemical liquid.

[0008] Another object of the present invention is to provide the use of the above-mentioned polypropylene composition resistant to electroplating chemical liquid in the preparation of accessories and hangers in electroplating tanks.

[0009] Another object of the present invention is to provide an electroplating tank and surrounding accessories prepared from the above-mentioned polypropylene composition.

[0010] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0011] A polypropylene composition resistant to electroplating chemical liquid comprises the following components in parts by weight: 90-100 parts of polypropylene resin, 0.3-1 parts of PE wax, 0.3-0.6 parts of amide lubricants, 0.3-0.6 parts of glyceride lubricants, 0.1-0.5 parts of nucleating agents, and 0-5 parts of glass fibers;

[0012] Wherein, the isotacticity of the polypropylene resin is ≥97.5%, and the nucleating agent is at least one of a carboxylic acid metal salt or an organic phosphate metal salt.

[0013] Polyethylene wax (PE wax), also known as polymer wax, is widely used due to its excellent cold resistance, heat resistance, chemical resistance and wear resistance. In normal production, this part of wax can be directly added to polyolefin processing as an additive, which can increase the gloss and processing performance of the product. As a lubricant, it has stable chemical properties and good electrical properties. Adding PE wax can improve the lubricity, hydrophobicity, and point insulation of the surface of polypropylene materials; adding nucleating agents can promote polypropylene to improve crystallinity and surface density, which is beneficial to prevent acidic, alkaline, copper salts, soaps, and other small molecules in the electroplating chemical solution from entering the material from the outside. In the process of PE wax and PP crystallization, amide lubricants will gradually precipitate to the surface, thereby forming a protective film that can block small molecules in the chemical solution.

[0014] Glycerol ester lubricants reduce the adsorption of bubbles on the surface of parts. Glycerol esters are polyol-type non-ionic surfactants with good surface activity. When parts enter the aqueous solution, the bubbles quickly detach from the surface of the parts.

[0015] Preferably, the isotacticity of the polypropylene resin is selected from one of 97.5%, 98%, 98.5% and 99%.

[0016] The polypropylene of the present invention is used as the basic raw material of the polypropylene composition resistant to electroplating chemical liquid. Its own isotacticity is crucial. The higher the isotacticity of the polypropylene, the better the crystallinity and the higher the density. Correspondingly, the better the resistance to electroplating chemical liquid is. The present invention selects polypropylene with an isotacticity of ≥97.5% to obtain a composition with good resistance to electroplating chemical liquid.

[0017] Preferably, the melt mass flow rate of the polypropylene resin at 230° C. and a load of 2.16 kg is 3 to 80 g / 10 min, preferably 10 to 60 g / 10 min.

[0018] Preferably, the melt mass flow rate of the PE wax at 190° C. and a load of 2.16 kg is 0.2 to 10 g / 10 min.

[0019] Preferably, the melting point of the PE wax is 135-155°C and the density is 0.955-0.960 g / cm 3 .

[0020] The PE wax described in the present invention includes conventional polyethylene wax and also includes ethylene acrylic acid copolymer wax powder.

[0021] Preferably, the amide lubricant is selected from at least one of erucamide, stearyl erucamide, oleamide or behenyl fatty amide.

[0022] Specifically, the carboxylic acid metal salt is selected from at least one of sodium benzoate, potassium benzoate or sodium p-toluenesulfonate, and the organic phosphate metal salt is selected from at least one of 2,2'-methylenebis(2.4-di-tert-butylphenoxy) sodium phosphate, 2.2'-methylenebis(4.6-di-tert-butylphenoxy)aluminum phosphate basic salt or sodium p-tert-butylphenoxy phosphate.

[0023] Preferably, the glyceride lubricant is selected from at least one of glyceryl monostearate, glyceryl laurate or fatty acid diglyceride.

[0024] Preferably, the glass fiber is selected from at least one of ESC-13-03-508C boulder glass fiber and ESC3F-03-508A boulder glass fiber.

[0025] More preferably, the average diameter of the glass fiber is 10-15 μm.

[0026] More preferably, the average diameter of the glass fiber is 13 μm.

[0027] Preferably, the polypropylene composition resistant to electroplating chemical liquid further comprises 0.4 to 1.6 parts of other additives.

[0028] More preferably, the other auxiliary agent is selected from at least one of an antioxidant, a light stabilizer or white mineral oil.

[0029] Specifically, the antioxidant is 0.1 to 0.6 parts, the light stabilizer is 0.1 to 0.5 parts, and the white mineral oil is 0.2 to 0.5 parts.

[0030] Specifically, the antioxidant is a compound antioxidant composed of a hindered phenol antioxidant and a phosphite antioxidant. More preferably, the compound antioxidant is composed of antioxidant 1010 and antioxidant 168, wherein the mass ratio of antioxidant 1010 to antioxidant 168 is 1 to 2: 1. More preferably, the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1.

[0031] Specifically, the light stabilizer is a hindered amine light stabilizer, selected from at least one of UV3808PP5, LA-402AF or UV770. More preferably, the relative molecular weight of the hindered amine light stabilizer is ≥800, and the melting point is 120-140°C.

[0032] The method for preparing the polypropylene composition resistant to electroplating chemical liquid comprises the following steps:

[0033] S1. The polypropylene resin, PE wax, amide lubricant, glyceride lubricant, nucleating agent, optional glass fiber and other additives are mixed to obtain a mixture;

[0034] S2. The mixture is melt-kneaded and extruded into pellets to obtain the polypropylene composition.

[0035] Preferably, the melt-kneading is carried out in a twin-screw extruder.

[0036] Preferably, the mixing temperature is 170-220° C., and the screw speed is 350-450 rpm.

[0037] The use of the polypropylene composition resistant to electroplating chemical liquid in the preparation of accessories and hangers in electroplating tanks is also within the protection scope of the present invention.

[0038] The present invention also protects a kind of accessory parts in and around the electroplating tank, which are prepared from the above polypropylene composition.

[0039] Preferably, the electroplating chemical resistant polypropylene part comprises at least one of a tray, a bracket or a hook.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The polypropylene composition resistant to electroplating chemical liquid provided by the present invention is prepared by adding PE wax, amide lubricant, glyceride lubricant, phosphoric acid metal salt or carboxylic acid metal salt nucleating agent to comprehensively modify the polypropylene resin, so that the obtained polypropylene composition maintains good mechanical properties and good electroplating chemical liquid resistance, and can be used to prepare accessories in and around the electroplating tank, such as a material tray, a bracket, a hook, etc.

[0042] The polypropylene composition resistant to electroplating chemical liquid provided by the present invention maintains good mechanical properties and has no distortion, stratification, melting, cracking, whitening, discoloration or dirtiness after being immersed in the electroplating chemical liquid. The discoloration level is 4 to 5, and it has good electroplating chemical liquid resistance and mechanical properties. DETAILED DESCRIPTION

[0043] The present invention is further described below in conjunction with examples. These examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually carried out according to conventional conditions in the art or according to the conditions recommended by the manufacturer; the raw materials, reagents, etc. used, unless otherwise specified, are all raw materials and reagents that can be obtained from commercial channels such as conventional markets. Any non-substantial changes and substitutions made by those skilled in the art on the basis of the present invention belong to the scope of protection claimed by the present invention.

[0044] Some of the reagents selected in the embodiments and comparative examples of the present invention are described as follows:

[0045] Polypropylene 1: brand PP 225 (STL), manufacturer Satellite Petrochemical, according to GB / T 2412-2008 standard, isotacticity is 98.8; according to ISO1133-2022 standard, the melt mass flow rate at 230°C and 2.16kg is 29g / 10min;

[0046] Polypropylene 2: brand K1118, manufacturer Sinopec, according to GB / T 2412-2008 standard, isotacticity is 96.5; according to ISO1133-2022 standard, the melt flow rate at 230°C and 2.16kg (same test conditions) is 17g / 10min;

[0047] Polypropylene 3: Brand CJS700H, manufacturer Sinopec, according to GB / T 2412-2008 standard, isotacticity is 98.3; according to ISO1133-2022 standard, the melt mass flow rate at 230°C and 2.16kg is 10g / 10min;

[0048] Polypropylene 4: brand P901, manufacturer SCG, according to GB / T 2412-2008 standard, isotacticity is 98.5; according to ISO1133-2022 standard, the melt mass flow rate at 230°C and 2.16kg is 60g / 10min;

[0049] Polypropylene 5: brand P401S, manufacturer SCG, according to GB / T 2412-2008 standard, isotacticity is 98.1; according to ISO1133-2022 standard, the melt mass flow rate at 230°C and 2.16kg is 3g / 10min;

[0050] Polypropylene 6: Brand K7100, manufacturer Sinopec, according to GB / T 2412-2008 standard, isotacticity is 98.1; according to ISO1133-2022 standard, the melt mass flow rate at 230°C and 2.16kg is 80g / 10min;

[0051] Polypropylene 7: Brand CS820, manufacturer Sinopec, according to GB / T 2412-2008 standard, isotacticity is 97.5; according to ISO1133-2022 standard, the melt flow rate at 230℃ and 2.16kg is 24g / 10min;

[0052] PE wax 1: brand AC-504A, manufacturer Honeywell;

[0053] PE wax 2: brand LP1040P, manufacturer SCG, Thailand;

[0054] Amide lubricant 1: oleic acid amide, commercially available;

[0055] Amide lubricant 2: erucic acid amide, commercially available;

[0056] Amide lubricant 3: stearyl erucic acid amide, commercially available;

[0057] Non-amide lubricant 1: stearic acid, commercially available;

[0058] Glyceride lubricant 1: glyceryl monostearate, commercially available;

[0059] Glyceride lubricant 2: fatty acid diglyceride, commercially available;

[0060] Nucleating agent 1: carboxylic acid metal salt, sodium benzoate, manufacturer Chenghe Technology;

[0061] Nucleating agent 2: phosphoric acid metal salt, 2,2'-methylenebis(2,4-di-tert-butylphenoxy) sodium phosphate, brand NA-11, manufacturer Aidico;

[0062] Nucleating agent 3: sorbitol, brand name Millad 3988, manufacturer Milliken;

[0063] Nucleating agent 4: sorbitol acetal, 1,2,3,4-dibenzylidene sorbitol, brand name Millad 3905, manufacturer Milliken;

[0064] Glass fiber: brand ESC3F-03-508A, manufacturer Jushi Glass Fiber;

[0065] Antioxidant 1: hindered phenol antioxidant, antioxidant 1010, commercially available;

[0066] Antioxidant 2: phosphite antioxidant, antioxidant 168, commercially available;

[0067] Light stabilizer: hindered amine light stabilizer, brand LA-402AF, manufacturer Aidico;

[0068] White mineral oil: 10# white mineral oil, Shanghai Daliang Chemical;

[0069] The polypropylene compositions of the embodiments and comparative examples of the present invention are prepared by the following process:

[0070] S1. The components of the formula of each embodiment and comparative example are mixed uniformly to obtain a mixture;

[0071] S2. Add the mixture into a twin-screw extruder, melt-mix, set the extruder temperature at 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, the die at 210°C, the feed rate at 30 kg, the vacuum degree at -0.08, the screw speed at 380 rpm, and extrude and granulate to obtain the polypropylene composition.

[0072] The performance test methods and standards of the polypropylene compositions of the embodiments and comparative examples of the present invention are as follows:

[0073] Electroplating chemical liquid resistance test: Soak the test board in 20% citric acid, acetic acid, malic acid, hydrogen peroxide, polyoxyethylene alcohol, sodium phytate, glycerol, triethanolamine, sulfonamide, chromium oxidant, imidazoline, and fatty alcohol surfactants for 24 hours, drain the surface, and use pure water to clean the surface of the test board. Judgment method: Check whether there is distortion, delamination, melting, cracking, whitening, discoloration, dirt, etc. after the test; use a 30x microscope to observe whether there is crack or delamination on the surface.

[0074] Color change grade: Tested in accordance with GB / T 250-2008 and graded according to color difference changes.

[0075] Table 1 Color difference rating GB / T 250-2008

[0076] Fastness grade CIELAB color difference Tolerance 5 0 0.2 (4-5) 0.8 ±0.2 4 1.7 ±0.3 (3-4) 2.5 ±0.35 3 3.4 ±0.4 (2-3) 4.8 ±0.5 2 6.8 ±0.6 (1-2) 9.6 ±0.7 1 13.6 ±1.0

[0077] Impact property determination: Tested based on ISO 179, with a pendulum energy of 2J at 23°C.

[0078] Determination of flexural modulus: Tested based on ISO 178, loading speed: 2 mm / min.

[0079] Examples 1 to 22

[0080] This embodiment provides a series of polypropylene compositions, the weight fractions of the components in the formulations, the electroplating chemical liquid resistance, the impact properties and the flexural modulus are shown in Tables 2 and 3.

[0081] Table 2 Examples 1 to 14 formulations (parts)

[0082]

[0083] Table 3 Examples 15 to 22 formulations (parts)

[0084]

[0085]

[0086] Comparative Examples 1 to 10

[0087] This comparative example provides a series of polypropylene compositions, the weight proportions of the components in the formulation, the electroplating chemical liquid resistance, the impact properties and the flexural modulus are shown in Table 4.

[0088] Table 4 Formulas of Comparative Examples 1 to 10 (parts)

[0089]

[0090]

[0091] It can be seen from Table 2 and Table 3 that the polypropylene compositions prepared in Examples 1 to 22 of the present invention all have the characteristics of being resistant to electroplating chemical liquids, and the impact strength can reach 3.1 KJ / m 2 The above-mentioned bending modulus can reach above 1765 MPa, among which the comprehensive performance of Example 1 is the best, maintaining good mechanical properties and electroplating resistance. As can be seen from Table 4, in Comparative Example 1, polypropylene with an isotacticity lower than 97.5% is used as the matrix, and microcracks appear after chemical resistance; in Comparative Examples 2 and 3, the weight of PE wax is not within the range set by the present invention, and the polypropylene material appears microcracks, whitening, deformation, cracks or stratification after chemical resistance; the amide lubricant in Comparative Example 4 exceeds the range set by the present invention, and stratification occurs; Comparative Example 5 is modified with a non-amide lubricant, and microcracks appear after chemical resistance; Comparative Example 6 adds too much nucleating agent, resulting in warping and deformation, and the discoloration level increases, indicating that the number of nucleating agents needs to be within a certain range; Comparative Examples 7-8 use non-carboxylic acid metal salts or non-phosphoric acid metal salts as nucleating agents for modification, and white precipitates appear after chemical resistance; Comparative Example 9 adds 0 amide lubricant, and the surface of the chemical resistance appears whitening; Comparative Example 10 adds 0 nucleating agent, and the surface expands after chemical resistance.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A polypropylene composition resistant to electroplating chemical liquid, comprising the following components in parts by weight: 90-100 parts of polypropylene resin, 0.3-1 parts of PE wax, 0.3-0.6 parts of amide lubricants, 0.3-0.6 parts of glyceride lubricants, 0.1-0.5 parts of nucleating agents, and 0-5 parts of glass fibers; in, The isotacticity of the polypropylene resin is ≥97.5%, and the nucleating agent is at least one of a carboxylic acid metal salt or an organic phosphate metal salt.

2. The polypropylene composition according to claim 1, characterized in that The melt mass flow rate of the polypropylene resin at 230° C. and a load of 2.16 kg is 10 to 60 g / 10 min.

3. The polypropylene composition according to claim 1, characterized in that The amide lubricant is selected from at least one of erucamide, stearyl erucamide, oleamide or behenyl fatty amide.

4. The polypropylene composition according to claim 1, characterized in that The glyceride lubricant is selected from at least one of glyceryl monostearate, glyceryl laurate or fatty acid diglyceride.

5. The polypropylene composition according to claim 1, characterized in that The carboxylic acid metal salt is selected from at least one of sodium benzoate, potassium benzoate or sodium p-toluenesulfonate.

6. The polypropylene composition according to claim 1, characterized in that The organic phosphoric acid metal salt is selected from at least one of 2,2'-methylenebis(2.4-di-tert-butylphenoxy) sodium phosphate, 2.2'-methylenebis(4.6-di-tert-butylphenoxy) aluminum phosphate basic salt or sodium p-tert-butylphenoxy phosphate.

7. The polypropylene composition according to claim 1, characterized in that The polypropylene composition resistant to electroplating chemical liquid also includes 0.4 to 1.6 parts of other auxiliary agents.

8. The method for preparing the polypropylene composition according to any one of claims 1 to 7, comprising the following steps: S1. The polypropylene resin, amide lubricant, glyceride lubricant, PE wax, nucleating agent, optional glass fiber and other additives are mixed to obtain a mixture; S2. The mixture is melt-kneaded and extruded into pellets to obtain the polypropylene composition.

9. Use of the polypropylene composition according to any one of claims 1 to 7 in the preparation of accessories and hanging parts in electroplating tanks.

10. An accessory part for an electroplating tank and its surroundings, prepared from the polypropylene composition according to any one of claims 1 to 7.

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