Use of a nucleating agent in the preparation of high gloss polyolefin resins

Abstract

The application relates to the technical field of plastic products, in particular to application of a nucleating agent in preparation of high-gloss polyolefin resin, 3-7 parts of the nucleating agent are added into 1000 parts of the polyolefin resin, the particle size D(97) of the nucleating agent is 1-7 mu m, and the nucleating agent is a phosphate nucleating agent. Through a large amount of experimental research, it is found that the particle size of the nucleating agent can be controlled to prepare the high-gloss polyolefin resin. The reason is that when the high-gloss polypropylene resin is prepared, the particle sizes of the nucleating agent and various processing aids are uniform, the meltability and dispersibility are good in the double-screw conveying process, the polypropylene resin is granulated, the surface is regular, and the glossiness is good; when the particle size difference between the processing aid and the nucleating agent is large, the meltability is not uniform in the double-screw conveying process due to the non-uniform particle size, small-particle-size aids may be agglomerated due to the intermolecular force, the dispersibility is poor, and finally the glossiness of the product is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastic products, in particular to application of a nucleating agent in preparation of high-gloss polyolefin resin. BACKGROUND

[0002] Polypropylene (PP) resin is the lightest resin among commonly used resins at present, and is a kind of excellent thermoplastic synthetic resin. It is a colorless and translucent thermoplastic lightweight general-purpose plastic, and has the characteristics of chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties, good high-wear processing performance, odorless, non-toxic, etc. It is widely used in various fields such as automobiles, household appliances, food, etc. With the development of technology and the improvement of public aesthetic requirements, higher requirements for the surface gloss of plastic products are gradually put forward in the current application fields of household appliances and daily necessities.

[0003] The high-gloss plastic in the prior art is mainly PC (polycarbonate) material. For example, CN112795166A discloses a polycarbonate composite material for high-gloss plastic products and a preparation method thereof. The preparation method is as follows (expressed by weight parts): polycarbonate (PC) 60-99 parts, polymethyl methacrylate (PMMA) 0-20 parts, polyvinylidene fluoride (PVDF) 1-20 parts, antioxidant 0.1-0.5 parts, lubricant 0.1-2 parts are put into a high-speed mixer at 300-1500 rpm, mixed for 3-15 minutes, then added into a twin-screw extruder, and melt granulated to obtain a high-gloss composite material. The preparation process does not need to add pearl powder or metal powder additionally, and high-gloss effect can also be achieved. However, PC material has poor toughness and is easily broken, and is not suitable for application in the field of household appliances.

[0004] In addition, a brightener is sprayed on the surface of the plastic product to form a thin film layer on the surface of the product, so that the surface gloss of the product is improved. For example, CN111113851A discloses a preparation method and device for high-gloss plastic products. The plastic is as follows by weight: resin: 98-99.9 parts; pearl resin: 0.1-2.0 parts. During the preparation process, the pearl resin is added from the pearl resin feeding device close to the metering section of the injection molding machine. Not only the size and integrity of the pearl resin are well preserved during the injection molding process, but also a considerable part of the pearl resin is selectively dispersed on the surface layer of the plastic, thereby increasing the content of the pearl resin on the surface layer of the product, and greatly improving the gloss of the plastic product.

[0005] For example, CN110194868A discloses a high-gloss polypropylene resin composition. The high-gloss polypropylene composition of the present application uses a prepared high-gloss polypropylene matrix resin as a raw material, supplemented with selected nucleating agents and brightener components. The preparation raw material includes the following mass content components: high-gloss polypropylene resin matrix 92-98 wt%; first nucleating agent 0.2-0.5 wt%; second nucleating agent 0.05-0.2 wt%; brightener 1-5 wt%; the first nucleating agent includes sorbitol nucleating agent; the second nucleating agent includes phosphate nucleating agent; an impact polypropylene resin with good gloss, impact resistance, rigidity, high rigidity and toughness balance, and low shrinkage is obtained.

[0006] However, such coating or brightener is often not completely compatible with polypropylene plastic, and the coating will fall off with repeated use of the product, making the product surface mottled and affecting the quality and appearance of the product.

[0007] Therefore, it has become one of the problems to be solved in the art to develop a polyolefin resin with more stable performance and high gloss. SUMMARY

[0008] The present application aims to provide an application of a nucleating agent in the preparation of a high-gloss polyolefin resin.

[0009] To solve the above technical problems, the present application provides the following technical solutions:

[0010] An application of a nucleating agent in the preparation of a high-gloss polyolefin resin, specifically: 3-7 parts of the nucleating agent are added to 1000 parts of the polyolefin resin, and the particle size D(97) of the nucleating agent is 1-7 μm. It is found through experiments that when the particle size of the nucleating agent is selected as 1 μm

[0011] Further, the nucleating agent is a phosphate nucleating agent.

[0012] Further, the particle size D(97) of the nucleating agent is 5.0±0.2 μm.

[0013] Further, 5 parts of the nucleating agent are added to 100 parts of the polyolefin resin.

[0014] Further, the polyolefin resin further comprises an antioxidant and / or an acid absorbent, and the particle size D(97) of the antioxidant and the acid absorbent is 5.0±0.2 μm. It is found through a large number of experimental studies that the particle size of other additives also affects the surface gloss of the sample, and therefore the optimal particle size D(97) is selected as 5.0±0.2 μm.

[0015] The antioxidant is a phenolic antioxidant and / or a phosphite antioxidant.

[0016] The phenolic antioxidant is phenolic antioxidant 1076 or phenolic antioxidant 1010.

[0017] The phosphite antioxidant is phosphite antioxidant 168 or phosphite antioxidant 618.

[0018] The acid absorber is calcium stearate and / or zinc stearate.

[0019] Compared with the prior art, the application of the nucleating agent in preparing high-gloss polyolefin resin has at least the following beneficial effects:

[0020] Through a large number of experimental researches, it is found that the nucleating agent particle size can be used to prepare high-gloss polyolefin resin by controlling the particle size. The possible reason is that when preparing high-gloss polypropylene resin, the particle sizes of the nucleating agent and various processing aids are uniform, the meltability and dispersibility are good in the conveying process of the double screw, the surface of the prepared polypropylene resin is regular, and the gloss is good. When the particle sizes of various processing aids and the nucleating agent are greatly different, the meltability is not uniform due to the non-uniform particle sizes in the conveying process of the double screw, and the dispersibility becomes worse due to the agglomeration of small particle size aids caused by intermolecular forces, so that the gloss of the product is reduced. It is found by the present application that when the nucleating agent particle size D(97) is 5 μm±0.2 μm, the surface gloss of the sample is the best, which is 83.1°.

[0021] The application of the nucleating agent in preparing high-gloss polyolefin resin will be further described below in combination with specific examples. DETAILED DESCRIPTION

[0022] Example 1

[0023] The application of a nucleating agent in preparing high-gloss polyolefin resin, wherein the specific formula is as follows:

[0024] Polypropylene resin: Dushanzi Petrochemical, model K9928H, 1000 parts;

[0025] Nucleating agent: Shanghai Qilin, QSZ-9512, phosphate nucleating agent, D(97) is 5 μm±0.2 μm, 5 parts;

[0026] Antioxidant 1010: commercially available, further crushed, D(97) is 5 μm±0.2 μm, 10 parts;

[0027] Antioxidant 168: commercially available, further crushed, D(97) is 5 μm±0.2 μm, 10 parts;

[0028] Antacid agent calcium stearate: commercially available, after crushing, D(97) is 5 pm ± 0.2 pm, 8 parts.

[0029] Sample preparation process: the above polypropylene resin, nucleating agent, antioxidant, acid absorbent are compounded and mixed according to the proportion, placed in a high-speed mixer and uniformly mixed for 10-20 min, the mixed material reaches the feeding bin of the twin-screw extruder through the feeding port, the twin-screw extruder is preheated, after completion, the material is conveyed to the twin-screw extruder for extrusion and granulation, and the temperature control of the twin-screw extruder is as shown in Table 1.

[0030] Table 1

[0031] warm zone zone 1 zone 2 zone 3 zone 4 zone 5 zone 6 zone 7 zone 8 zone 9 zone 10 zone 11 temperature, °c 160 170 180 190 195 190 185 175 180 185 190

[0032] Then, the test sample bar is injected into the injection molding machine (injection molding machine temperature 260℃), the sample bar is conditioned in an environment with a temperature of 23±2℃ and a humidity of 50±5%, the conditioning time is more than 48h, and then the performance test is carried out.

[0033] The aging test is tested according to the test method of method A in GB / T 16422.3-2022, and then the gloss of the exposed sample is tested.

[0034] The test standard of gloss is GB / T 8807-1988 "Plastic mirror surface gloss test method". The sample is selected to have smooth and flat surface, no dirt, scratch and other defects. The surface gloss of the sample is tested at an incident angle of 60°, and the gloss ≥70.0° is high gloss.

[0035] Example 2

[0036] The application of a nucleating agent in the preparation of high-gloss polyolefin resin, the difference from example 1 is only that the addition amount of nucleating agent is 3 parts, and the rest of the conditions and preparation process are the same as example 1.

[0037] Example 3

[0038] The application of a nucleating agent in the preparation of high-gloss polyolefin resin, the difference from example 1 is only that the addition amount of nucleating agent is 7 parts, and the rest of the conditions and preparation process are the same as example 1.

[0039] Example 4

[0040] The application of a nucleating agent in the preparation of high-gloss polyolefin resin, the difference from example 1 is only that:

[0041] The nucleating agent is selected to have 6 pm < D(97) < 7 pm;

[0042] Antioxidant 1010: commercially available, after crushing, selected to have 6 pm < D(97) < 7 pm;

[0043] Antioxidant 168: commercially available, and then crushed, and selected 6 μm < D(97) < 7 μm;

[0044] Antioxidant 168: commercially available, and then crushed, and selected 6 μm < D(97) < 7 μm;

[0045] The remaining conditions and the preparation process are the same as those of Example 1.

[0046] Example 5

[0047] The application of a nucleating agent in the preparation of high-gloss polyolefin resin, which is only different from Example 1 in that:

[0048] The nucleating agent is selected to be 1 μm < D(97) < 2 μm;

[0049] Antioxidant 168: commercially available, and then crushed, and selected 6 μm < D(97) < 7 μm;

[0050] Antioxidant 168: commercially available, and then crushed, and selected 6 μm < D(97) < 7 μm;

[0051] Antioxidant 168: commercially available, and then crushed, and selected 6 μm < D(97) < 7 μm;

[0052] The remaining conditions and the preparation process are the same as those of Example 1.

[0053] Example 6

[0054] The application of a nucleating agent in the preparation of high-gloss polyolefin resin, which is only different from Example 1 in that:

[0055] The nucleating agent is selected to be 1 μm < D(97) < 2 μm;

[0056] Antioxidant 168: commercially available, and then crushed, and selected 6 μm < D(97) < 7 μm;

[0057] Antioxidant 168: commercially available, and then crushed, and selected 6 μm < D(97) < 7 μm;

[0058] Antioxidant 168: commercially available, and then crushed, and selected 6 μm < D(97) < 7 μm;

[0059] The remaining conditions and the preparation process are the same as those of Example 1.

[0060] In order to highlight the beneficial effects of the present application, the following comparative examples are given.

[0061] Comparative Example 1

[0062] Raw materials:

[0063] Polypropylene resin: Dushanzi Petrochemical, grade K9928H, 1000 parts;

[0064] Antioxidant 1010: commercially available and used directly, D(97) of which was tested as 185 μm, 10 parts;

[0065] Antioxidant 168: commercially available and used directly, D(97) of which was tested as 132 μm, 10 parts;

[0066] Acid-adsorbing agent calcium stearate: commercially available and used directly, D(97) of which was tested as 89.3 μm; 8 parts.

[0067] The sample preparation process and related parameters were the same as those of Example 1.

[0068] Comparative Example 2

[0069] Raw materials:

[0070] Polypropylene resin: Dushanzi Petrochemical, grade K9928H, 1000 parts;

[0071] Nucleating agent: Shanghai Qilin, QSZ-9512, a phosphate nucleating agent, the finished product was produced without crushing treatment, D(97) of which was tested as 44.9 μm, 5 parts

[0072] Antioxidant 1010: commercially available and used directly, D(97) of which was tested as 185 μm, 10 parts;

[0073] Antioxidant 168: commercially available and used directly, D(97) of which was tested as 132 μm, 10 parts;

[0074] Acid-adsorbing agent calcium stearate: commercially available and used directly, D(97) of which was tested as 89.3 μm; 8 parts.

[0075] The sample preparation process and related parameters were the same as those of Example 1.

[0076] Comparative Example 3

[0077] In comparison with Example 1, the only difference was that the nucleating agent with D(97) <1 μm was used, and the rest of the conditions and the preparation process were the same as those of Example 1.

[0078] Comparative Example 4

[0079] In comparison with Example 1, the only difference was that the nucleating agent with 7 μm < D(97) <10 μm was used, and the rest of the conditions and the preparation process were the same as those of Example 1.

[0080] Comparative Example 5

[0081] In comparison with Example 1, the only difference was that the amount of the nucleating agent was adjusted to 10 parts, and the rest of the conditions and the preparation process were the same as those of Example 1.

[0082] Comparative Example 6

[0083] Comparative Example 6

[0084] Comparative Example 7

[0085] Comparative Example 7

[0086] The nucleating agent was selected as 6 μm < D(97) < 7 μm;

[0087] Antioxidant 1010: commercially available, and then crushed, and selected as 10 μm < D(97) < 12 μm;

[0088] Antioxidant 168: commercially available, and then crushed, and selected as 10 μm < D(97) < 12 μm;

[0089] Antioxidant 168: commercially available, and then crushed, and selected as 10 μm < D(97) < 12 μm;

[0090] Comparative Example 7

[0091] The above examples and comparative examples were tested for performance, and the test results are shown in Table 2.

[0092] Table 2

[0093]

[0094] From the above experimental results, it can be seen that in the process of preparing high-gloss polypropylene resin, the particle size of the nucleating agent and other processing aids should be strictly controlled. A particle size that is too large or too small will affect the gloss of the product. The reason may be that when the particle size of the nucleating agent or other processing aids is too large, the meltability in the twin-screw conveying and extruding process will be poor, affecting the regularity of the polypropylene resin surface. When the particle size of the nucleating agent or other processing aids is too small, the nucleating agent and other processing aids will agglomerate due to the intra- or intermolecular forces during the mixing and dispersion process, which will further reduce the regularity of the polypropylene resin surface, thereby significantly reducing the gloss of the product.

[0095] Secondly, when testing the gloss of the product after the aging test, it is found that the effect of the aging test on the gloss is not large when the nucleating agent and other processing aids and the amount of addition and particle size are within a certain range, and when the particle size of the nucleating agent and other processing aids is too large or too small, it will obviously have a great effect on the gloss after aging, which may be because the nucleating agent and other processing aids have poor meltability and dispersibility due to the particle size being too large or too small, which further affects the quality of the product after the aging test. Moreover, it can be seen from Comparative Examples 5-6 that if the amount of addition of the nucleating agent is too high, the nucleating agent will not be uniformly dispersed in the polypropylene resin, and the phenomenon of nucleating agent agglomeration will occur, resulting in uneven particle size and affecting the gloss; if the amount of addition of the nucleating agent is too low, the crystal cell of the nucleating agent will be too dispersed, which will cause the surface gloss to be uneven, ultimately affecting the quality of the product.

[0096] The above-described embodiments are merely preferred embodiments of the present application and are not intended to limit the scope of the present application. Various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art without departing from the design spirit of the present application shall fall within the scope of protection of the present application as defined by the claims.

Claims

1. The application of a nucleating agent in the preparation of high-gloss polyolefin resin, characterized in that: 3-7 parts of nucleating agent are added to every 1000 parts of polyolefin resin. The nucleating agent is a phosphate nucleating agent with a particle size D (97) of 5 ± 0.2 μm. Antioxidant and / or acid scavenger are also added to the polyolefin resin. The particle size D (97) of the antioxidant and acid scavenger is 5 ± 0.2 μm. The antioxidant is a phenolic antioxidant and / or a phosphite antioxidant.

2. The application of the nucleating agent according to claim 1 in the preparation of high-gloss polyolefin resin, characterized in that: Add 5 parts nucleating agent to every 1000 parts of polyolefin resin.

3. The application of the nucleating agent according to claim 1 in the preparation of high-gloss polyolefin resin, characterized in that: The phenolic antioxidant is phenolic antioxidant 1076 or phenolic antioxidant 1010.

4. The application of the nucleating agent according to claim 1 in the preparation of high-gloss polyolefin resin, characterized in that: The phosphite antioxidant is phosphite antioxidant 168 or phosphite antioxidant 618.

5. The application of the nucleating agent according to claim 1 in the preparation of high-gloss polyolefin resin, characterized in that: The acid absorber is calcium stearate and / or zinc stearate.

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