Novel anti-shrinkage polypropylene material

Abstract

The invention belongs to the field of high polymer materials, and particularly relates to a novel anti-shrinkage polypropylene material which comprises the following components in parts by weight: 70-90 parts of polypropylene resin; 5-20 parts of an inorganic filler; 3 to 10 parts of a compatilizer; 0.05 to 1 part of a nucleating agent; 0.5-2 parts of a dispersant; the nucleating agent is prepared from an organic phosphoric acid metal salt compound and bis (4-tert-butylphenyl) amine. The invention further discloses a preparation method of the flame retardant. The polypropylene material disclosed by the invention has extremely excellent shrinkage resistance, and compared with a polypropylene material prepared by singly using organic phosphoric acid metal salt as a nucleating agent, the shrinkage resistance is greatly improved.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to a novel shrinkage-resistant polypropylene material. Background Art

[0002] Polypropylene (PP) is an important thermoplastic with low density, excellent mechanical properties, good chemical corrosion resistance, etc. It is widely used in automobiles, home appliances, packaging materials, injection molded products and other fields. However, polypropylene is prone to shrinkage and deformation during the molding process, resulting in defects such as poor dimensional accuracy and product cracking, which limits its application in high-demand fields.

[0003] At present, in order to solve the shrinkage problem of polypropylene materials, inorganic fillers, nucleating agents or anti-shrinkage agents are usually added. Nucleating agents are substances that can promote the formation and growth of crystal nuclei during the crystallization process of polypropylene. Their main function is to increase the crystallization rate and crystal density of the material, thereby improving the comprehensive performance of the polymer material. Organophosphate metal salt nucleating agents are an important class of polymer additives, which are widely used in polyolefins (such as polypropylene, polyethylene) and other polymers to improve the crystallization properties of materials, improve mechanical properties and optical properties. However, a single nucleating agent has limited effect on improving the anti-shrinkage properties of polypropylene materials. Therefore, there is an unmet need for composite nucleating agents in the art. Summary of the invention

[0004] In order to solve the above problems, in the first aspect, the present invention provides a novel shrinkage-resistant polypropylene material, which comprises the following components in parts by weight: 70-90 parts of polypropylene resin; 5-20 parts of inorganic filler; 3-10 parts of compatibilizer; 0.05-1 part of nucleating agent; 0.5-2 parts of dispersant; 0.5-1 part of lubricant and 0.3-1 part of antioxidant.

[0005] Furthermore, the nucleating agent consists of an organic phosphate metal salt compound and bis(4-tert-butylphenyl)amine.

[0006] Furthermore, the molar ratio of the organic phosphoric acid metal salt to bis(4-tert-butylphenyl)amine is 1:1-2.

[0007] Furthermore, the organophosphate metal salt compound is an organophosphate metal salt nucleating agent NA-11 (2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate sodium salt).

[0008] Among them, the structure of NA-11 is as follows:

[0009] The structure of bis(4-tert-butylphenyl)amine is shown below:

[0010] Furthermore, the polypropylene resin is homopolymer polypropylene, copolymer polypropylene or both.

[0011] Furthermore, the inorganic filler is selected from one or more of talc, calcium carbonate, wollastonite or glass fiber.

[0012] Furthermore, the compatibilizer is maleic anhydride grafted polypropylene.

[0013] Furthermore, the dispersant is ethylene stearamide.

[0014] Furthermore, the lubricant is at least one of calcium stearate, stearic acid, pentaerythritol stearate, silicone powder, and polyethylene wax.

[0015] Furthermore, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (antioxidant 1010) and / or tris[2,4-di-tert-butylphenyl]phosphite (antioxidant 168).

[0016] The present invention also provides a method for preparing the novel shrinkage-resistant polypropylene material as described herein, which comprises the following steps: mixing polypropylene resin, inorganic filler, compatibilizer, nucleating agent, dispersant, lubricant and antioxidant in proportion, and then using a twin-screw extruder to perform melt extrusion granulation in a temperature range of 190-230°C to obtain the shrinkage-resistant polypropylene material.

[0017] Advantageous Effects of the Invention

[0018] The present invention combines bis(4-tert-butylphenyl)amine with the commonly used organic phosphate metal salt nucleating agent NA-11 and adds it to the polypropylene matrix. It is unexpectedly found that the obtained polypropylene material has extremely excellent anti-shrinkage performance, which is greatly improved compared with the effect of NA-11 alone. This may be because both NA-11 and bis(4-tert-butylphenyl)amine have a V-shaped structure formed by two benzene rings, and the amino group in bis(4-tert-butylphenyl)amine forms hydrogen bond interactions with the oxygen atom of the phosphoric acid group in NA-11 and the amino group in other bis(4-tert-butylphenyl)amines, and forms a clover-like structure through steric hindrance, thereby forming a stable nucleation site and being able to entangle with more polypropylene molecular chains to quickly crystallize, making the grains more refined, thereby reducing the shrinkage rate. DETAILED DESCRIPTION

[0019] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0020] The polypropylene resin used in the following examples is a homopolymer polypropylene of 1040TE grade produced by Ningxia Coal Industry Co., Ltd. of the State Energy Group.

[0021] Embodiment 1:

[0022] A novel shrinkage-resistant polypropylene material comprises the following components in parts by weight: 80 parts of polypropylene resin; 15 parts of calcium carbonate; 5 parts of maleic anhydride grafted polypropylene; 1 part of an organic phosphate metal salt nucleating agent NA-11 and bis(4-tert-butylphenyl)amine in a molar ratio of 1:2; 1 part of ethylene stearamide; 0.5 parts of polyethylene wax, 0.5 parts of antioxidant 1010 and 0.5 parts of antioxidant 168.

[0023] The above components are mixed evenly with a high-speed mixer, and then loaded into a twin-screw extruder for extrusion, granulation and drying; the extrusion process of the twin-screw extruder is as follows: the temperatures of the five temperature zones are 190°C, 200°C, 210°C, 220°C and 230°C, the die temperature is 225°C, and the screw speed is 120r / min.

[0024] Example 2

[0025] A novel shrinkage-resistant polypropylene material comprises the following components in parts by weight: 70 parts of polypropylene resin; 5 parts of calcium carbonate; 3 parts of maleic anhydride grafted polypropylene; 1 part of an organic phosphate metal salt nucleating agent NA-11 and bis(4-tert-butylphenyl)amine in a molar ratio of 1:2; 1 part of ethylene stearamide; 0.5 part of polyethylene wax, 0.5 part of antioxidant 1010 and 0.5 part of antioxidant 168.

[0026] The above components are mixed evenly with a high-speed mixer, and then loaded into a twin-screw extruder for extrusion, granulation and drying; the extrusion process of the twin-screw extruder is as follows: the temperatures of the five temperature zones are 190°C, 200°C, 210°C, 220°C and 230°C, the die temperature is 225°C, and the screw speed is 120r / min.

[0027] Example 3

[0028] A novel shrinkage-resistant polypropylene material comprises the following components in parts by weight: 90 parts of polypropylene resin; 20 parts of calcium carbonate; 10 parts of maleic anhydride grafted polypropylene; 0.8 parts of an organic phosphate metal salt nucleating agent NA-11 and bis(4-tert-butylphenyl)amine in a molar ratio of 1:2; 2 parts of ethylene stearamide; 0.5 parts of pentaerythritol stearate, 0.5 parts of an antioxidant 1010 and 0.5 parts of an antioxidant 168.

[0029] The above components are mixed evenly with a high-speed mixer, and then loaded into a twin-screw extruder for extrusion, granulation and drying; the extrusion process of the twin-screw extruder is as follows: the temperatures of the five temperature zones are 190°C, 200°C, 210°C, 220°C and 230°C, the die temperature is 225°C, and the screw speed is 120r / min.

[0030] Example 4

[0031] Same as Example 1, except that the molar ratio of NA-11 to bis(4-tert-butylphenyl)amine was 1:1.

[0032] Comparative Example 1

[0033] Same as Example 1, except that the molar ratio of NA-11 to bis(4-tert-butylphenyl)amine was 1:0.5.

[0034] Comparative Example 2

[0035] Same as Example 1, except that the molar ratio of NA-11 to bis(4-tert-butylphenyl)amine was 1:3.

[0036] Comparative Example 3

[0037] The same as Example 1, except that the nucleating agent is only the organophosphate metal salt nucleating agent NA-11.

[0038] Comparative Example 4

[0039] Same as Example 1, except the nucleating agent was bis(4-tert-butylphenyl)amine only.

[0040] Comparative Example 5

[0041] The same as Example 1, except that the nucleating agent is an organophosphate metal salt nucleating agent NA-11 and 3,5-di-tert-butylaniline in a molar ratio of 1:2.

[0042] Comparative Example 6

[0043] Same as Example 1, except no nucleating agent was used.

[0044] Test Case

[0045] The samples of the embodiments and comparative examples were tested for molding shrinkage and mechanical properties according to the following test methods:

[0046] Flow horizontal shrinkage is tested according to ASTM D955-2008 standard;

[0047] The shrinkage in the direction perpendicular to the flow is tested according to ASTM D955-2008;

[0048] Tensile strength, tested according to ASTM D638-2003;

[0049] Impact strength is tested according to ASTM D256-2010 standard.

[0050] The results are shown in Table 1

[0051] Table 1

[0052]

[0053] From the results in Table 1, it can be seen that in the process of increasing the molar ratio of NA-11 and bis(4-tert-butylphenyl)amine from 1:0.5 to 1:3 (Example 1, Example 4 and Comparative Examples 1-2), the shrinkage rate of the polypropylene material continues to decrease. When it reaches 1:3, the shrinkage rate is almost unchanged, but the mechanical properties are weakened, indicating that the appropriate molar ratio of NA-11 and 3,5-di-tert-butylaniline is 1:1-2. From the results of Comparative Example 3, it can be seen that the nucleating agent composed only of NA-11 can only reduce the shrinkage rate to 0.98 / 1.06, while according to Example 1, it can be seen that the nucleating agent composed of NA-11 and bis(4-tert-butylphenyl)amine greatly reduces the shrinkage rate to 0.57 / 0.60. From Comparative Example 4, it can be seen that when only bis(4-tert-butylphenyl)amine is used as a nucleating agent, the shrinkage rate of polypropylene decreases very weakly, indicating that bis(4-tert-butylphenyl)amine needs to be matched with NA-11 to work. It can be seen from Comparative Example 5 that when 3,5-di-tert-butylaniline is used instead of bis(4-tert-butylphenyl)amine, it is unable to increase the shrinkage-reducing effect of organic phosphates on polypropylene.

[0054] It should be noted that the preferred embodiments of the present invention are given in the specification of the present invention, but the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments are not intended to be additional limitations on the content of the present invention. The purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. In addition, the above-mentioned technical features continue to be combined with each other to form various embodiments not listed above, which are all considered to be within the scope of the present invention specification; further, for ordinary technicians in this field, they can be improved or transformed according to the above description, and all these improvements and transformations should belong to the protection scope of the claims attached to the present invention.

Claims

1. A novel shrinkage-resistant polypropylene material, characterized in that: The material comprises the following components in parts by weight: 70-90 parts of polypropylene resin; 5-20 parts of inorganic filler; Compatibilizer: 3-10 parts; Nucleating agent: 0.05-1 part; Dispersant: 0.5-2 parts; lubricant 0.5-1 parts and antioxidant 0.3-1 parts.

2. The material according to claim 1, characterized in that The nucleating agent consists of an organic phosphoric acid metal salt compound and bis(4-tert-butylphenyl)amine.

3. The material according to claim 1, characterized in that The molar ratio of the organic phosphoric acid metal salt to bis(4-tert-butylphenyl)amine is 1:1-2.

4. The material according to claim 1, characterized in that The polypropylene resin is homopolymer polypropylene, copolymer polypropylene or both.

5. The material according to claim 1, characterized in that The inorganic filler is selected from one or more of talc, calcium carbonate, wollastonite or glass fiber.

6. The material according to claim 1, characterized in that The compatibilizer is maleic anhydride grafted polypropylene.

7. The material according to claim 1, characterized in that The dispersant is ethylene stearamide.

8. The material according to claim 1, characterized in that The lubricant is at least one of calcium stearate, stearic acid, pentaerythritol stearate, silicone powder and polyethylene wax.

9. The material according to claim 1, characterized in that The antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1010) and / or tris[2,4-di-tert-butylphenyl]phosphite (antioxidant 168).

10. The method for preparing the novel shrinkage-resistant polypropylene material according to any one of claims 1 to 9, characterized in that: The following steps are involved: After polypropylene resin, inorganic filler, compatibilizer, nucleating agent, dispersant, lubricant and antioxidant are mixed in proportion, a twin-screw extruder is used to perform melt extrusion granulation at a temperature range of 190-230 DEG C to obtain an anti-shrinkage polypropylene material.

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