A low-odor polypropylene composite material for extruded pipes and its preparation method

Abstract

The invention belongs to the technical field of polymer materials, and relates to a low-odor polypropylene composite material for extruded pipes and a preparation method thereof. The low-odor polypropylene composite material for extruded pipes includes 100 parts of polypropylene and 8-30 parts of modified diatomite by weight; the modified diatomite is obtained by mixing diatomite with a mass ratio of 1:1-3 and nano-powder, and the nano-powder is obtained by mixing nano-calcium carbonate with HDPE with a mass ratio of 1:1-2, melt-extruding and grinding; the preparation method is: after mixing each component uniformly according to the ratio, melt-extrude from a twin-screw extruder, and obtain the low-odor polypropylene composite material for extruded pipes. The preparation method of the invention is simple, and the obtained polypropylene composite material will not break during the extrusion of the pipe, and has a low-odor effect.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials and relates to a low-odor polypropylene composite material for extruded pipes and a preparation method thereof. Background Art

[0002] As a general-purpose plastic, polypropylene is widely used in injection molding and extrusion products. People's environmental awareness and safety awareness are getting stronger and stronger. my country has issued the in-car air quality standard GB / T27630-2011 "Guidelines for Passenger Car In-car Air Quality Evaluation" to protect the health and safety of drivers and passengers. With the standardization of low-odor requirements for automotive interior materials, related industries are also shifting towards this trend.

[0003] Most existing technologies use chemical reactions, physical adsorption, vacuum volatilization and high-temperature baking to improve the odor and emission problems of polypropylene materials. Among them, chemical reactions, vacuum volatilization and high-temperature baking will bring dual pressures of cycle and cost. Relatively speaking, physical adsorption is the most economical low-odor treatment method, but it is limited to the injection molding industry.

[0004] Physical adsorption uses porous materials as odor adsorbents. Diatomaceous earth is a commonly used odor adsorbent with a loose porous structure, but at the same time, its specific surface area is too large, which will destroy the uniformity of the material. In the injection molding industry, qualified materials can be produced after mold characterization, pressure holding and cooling. However, compared with the polypropylene composite materials used in the injection molding industry, the polypropylene composite materials used in the extrusion industry have low fluidity and are more likely to generate shear heat during processing, causing the material to produce more odor, especially in extruded pipes. The material has not been shaped by mold pressure holding and cooling. During the extrusion traction process, it is easy to cause surface defects of the pipe, leading to pipe rupture. Summary of the invention

[0005] The purpose of the invention is to solve the problems existing in the prior art and provide a low-odor polypropylene composite material for extruded pipes.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A low-odor polypropylene composite material for extruded pipes, comprising 100 parts of polypropylene and 8-30 parts of modified diatomaceous earth by weight;

[0008] The modified diatomaceous earth is obtained by mixing diatomaceous earth and nanometer powder in a mass ratio of 1:1-3, and the nanometer powder is obtained by mixing nanometer calcium carbonate and HDPE in a mass ratio of 1:1-2, and then melting, extruding and grinding.

[0009] The pores of the modified diatomaceous earth of the present invention are filled with nano-calcium carbonate and HDPE; HDPE and polypropylene both belong to polyolefins and have similar compatibility, and the crystallinity of HDPE (80%-90%) is higher than that of polypropylene (40%-60%). Therefore, during the pipe extrusion process, HDPE will attract polypropylene to approach the diatomaceous earth, so that the extruded pipe will not break; nano-calcium carbonate has a spherical structure and it is difficult to completely fill the pores of the diatomaceous earth. Nano-calcium carbonate and HDPE are both located in the pores of the diatomaceous earth, which can prevent HDPE from completely filling the pores of the diatomaceous earth and ensure that the diatomaceous earth can play the role of odor adsorption.

[0010] The proportion of HDPE in the modified diatomaceous earth should not be too low, otherwise the extruded pipe will not be prevented from breaking, and the proportion of nano-calcium carbonate should not be too low either, otherwise it cannot be ensured that the diatomaceous earth can play the role of odor adsorption. The present invention controls the proportion of HDPE and the proportion of nano-calcium carbonate in the modified diatomaceous earth by controlling the mass ratio of diatomaceous earth to nano-powder and the mass ratio of nano-calcium carbonate to HDPE.

[0011] As a preferred technical solution:

[0012] For a low-odor polypropylene composite material for extruded pipes as described above, a high-speed mixer is used when mixing diatomaceous earth and nano-powder, the mixing time is 3-5 min, and the mixing speed is 400 rpm.

[0013] For a low-odor polypropylene composite material for extruded pipes as described above, the diatomaceous earth has a porous structure with a pore diameter of 50-3000 nm.

[0014] For a low-odor polypropylene composite material for extruded pipes as described above, the particle size of the nano-powder is 50-100 nm.

[0015] For a low-odor polypropylene composite material for extruded pipes as described above, the melt index of polypropylene at 230°C and 2.16 kg is 0.2-3 g / 10 min.

[0016] For a low-odor polypropylene composite material for extruded pipes as described above, by weight, it further includes 1 part of antioxidant and 1 part of processing aid.

[0017] For a low-odor polypropylene composite material for extruded pipes as described in any one of the above, the odor grade of the low-odor polypropylene composite material for extruded pipes measured according to the public odor detection standard PV3900 is 3.0. It can be seen that this composite material has a low-odor effect; for an extruded pipe made of the low-odor polypropylene composite material for extruded pipes, a section with a length of 50 cm is intercepted, both ends are sealed, and it is placed in water. After filling the section with gas, no bubbles are generated in the water. It can be seen that the extruded pipe does not break.

[0018] The present invention also provides a method for preparing a low-odor polypropylene composite material for extruded pipes as described in any one of the above. After mixing each component evenly according to the ratio, it is melt-extruded from a twin-screw extruder to obtain the low-odor polypropylene composite material for extruded pipes.

[0019] Beneficial effects:

[0020] (1) The present invention overcomes the problem that the low-odor polypropylene material prepared by using diatomite adsorption means in the prior art is prone to cracking during the extrusion of pipes. The diatomite used belongs to inorganic filler and is cheap, and has great economic benefits compared with means such as vacuum adsorption, chemical reaction, and high-temperature drying of materials.

[0021] (2) The present invention can save energy to a certain extent, reduce carbon emissions, has great significance for achieving the goals of carbon peak and carbon neutrality, and is beneficial to environmental protection. Specific embodiments

[0022] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0023] The following are the test methods for the performance in the embodiments:

[0024] Odor grade: Determined in accordance with the general odor detection standard PV3900.

[0025] Whether the extruded pipe made of the low-odor polypropylene composite material for extruded pipes is cracked or not: The low-odor polypropylene composite material for extruded pipes in the embodiment is made into an extruded pipe, a section with a length of 50 cm is intercepted, both ends are sealed, placed in water, and after filling the section with gas, observe whether there are bubbles in the water. If there are no bubbles, the extruded pipe is not cracked.

[0026] In the following embodiments, the manufacturers of the antioxidant and processing aids have no obvious influence on the performance of the low-odor polypropylene composite material for extruded pipes of the present invention, so they will not be elaborated below.

[0027] Example 1

[0028] A method for preparing a low-odor polypropylene composite material for extruded pipes, the specific steps are as follows:

[0029] (1) Preparation of raw materials;

[0030] Nano calcium carbonate: The manufacturer is Quanzhou Xufeng Powder Raw Material Co., Ltd., and the grade is NC-90A;

[0031] HDPE: Manufacturer is Korea Petrochemical Industry Co., Ltd., grade is B502;

[0032] Diatomaceous earth: Manufacturer is Shengzhou Huali Diatomaceous Earth Products Co., Ltd., grade is CD06, pore diameter is 50 - 700 nm;

[0033] Polypropylene: Manufacturer is Formosa Plastics Corporation, Taiwan, China, grade is 3003;

[0034] Antioxidant: Antioxidant 1010;

[0035] Processing aid: EBS;

[0036] (2) After mixing nano - calcium carbonate and HDPE evenly, melt - extrude and grind to obtain nano - powder with a particle size of 50 - 100 nm; among them, the mass ratio of nano - calcium carbonate to HDPE is 1:1;

[0037] (3) Use a high - speed mixer to mix diatomaceous earth and nano - powder evenly to obtain modified diatomaceous earth; among them, the mass ratio of diatomaceous earth to nano - powder is 1:1, the mixing time is 3 min, and the rotation speed is 400 rpm;

[0038] (4) By weight, mix 100 parts of polypropylene, 8 parts of modified diatomaceous earth, 1 part of antioxidant and 1 part of processing aid evenly, and then melt - extrude from a twin - screw extruder to obtain a low - odor polypropylene composite material for extruded pipes.

[0039] The odor level of the finally obtained low - odor polypropylene composite material for extruded pipes is 3, and the extruded pipes made of the low - odor polypropylene composite material for extruded pipes do not rupture.

[0040] Comparative Example 1

[0041] A preparation method of a polypropylene composite material for extruded pipes is basically the same as that of Example 1, the only difference being that: in step (2), the mass ratio of nano - calcium carbonate to HDPE is 2:1.

[0042] Prepare the finally obtained polypropylene composite material for extruded pipes into extruded pipes, and the extruded pipes rupture.

[0043] Comparing Comparative Example 1 and Example 1, it can be seen that due to the too small addition amount of HDPE in Comparative Example 1, the amount of HDPE existing in the pores of diatomaceous earth is too small, and the acting force on polypropylene is relatively small, resulting in the rupture of the extruded pipes.

[0044] Comparative Example 2

[0045] A preparation method of a polypropylene composite material for extruded pipes is basically the same as that of Example 1, the only difference being that: in step (2), the mass ratio of nano - calcium carbonate to HDPE is 1:3.

[0046] The odor grade of the finally obtained polypropylene composite material for extruded pipes is 4.0.

[0047] Comparing Comparative Example 2 with Example 1, it can be seen that the odor grade of the polypropylene composite material for extruded pipes in Comparative Example 2 is poor because the excessive addition amount of HDPE blocks the porous structure of diatomite, resulting in poor adsorption capacity of diatomite.

[0048] Comparative Example 3

[0049] A preparation method of a polypropylene composite material for extruded pipes is basically the same as that of Example 1, except that: in step (3), the mass ratio of diatomite to nano powder is 2:1.

[0050] The finally obtained polypropylene composite material for extruded pipes was made into an extruded pipe, and the extruded pipe burst.

[0051] Comparing Comparative Example 3 with Example 1, it can be seen that due to the excessive addition amount of diatomite in Comparative Example 3, the homogeneity of the material is severely damaged, resulting in the rupture of the pipe.

[0052] Comparative Example 4

[0053] A preparation method of a polypropylene composite material for extruded pipes is basically the same as that of Example 1, except that: in step (3), the mass ratio of diatomite to nano powder is 1:4.

[0054] The odor grade of the finally obtained polypropylene composite material for extruded pipes is 4.0.

[0055] Comparing Comparative Example 4 with Example 1, it can be seen that the odor grade of the polypropylene composite material for extruded pipes in Comparative Example 4 is poor because the excessive filling amount of nano powder results in poor adsorption capacity of modified diatomite.

[0056] Example 2

[0057] A preparation method of a low-odor polypropylene composite material for extruded pipes is as follows:

[0058] (1) Preparation of raw materials;

[0059] Nano calcium carbonate: The manufacturer is Quanzhou Xufeng Powder Raw Material Co., Ltd., and the grade is NC-90A;

[0060] HDPE: The manufacturer is China Petroleum & Chemical Corporation Shanghai Petrochemical Company Limited, and the grade is 5502;

[0061] Diatomite: The manufacturer is Shengzhou Huali Diatomite Products Co., Ltd., and the grade is CD07, with a pore diameter of 50 - 1500 nm;

[0062] Polypropylene: Manufacturer is Formosa Plastics Corporation, Taiwan, China, grade is 3009;

[0063] Antioxidant: Antioxidant 168;

[0064] Processing aid: Calcium stearate;

[0065] (2) After uniformly mixing nano calcium carbonate and HDPE, melt extrude and grind to obtain nano powder with a particle size of 50 - 100 nm; among them, the mass ratio of nano calcium carbonate to HDPE is 1:1;

[0066] (3) Use a high-speed mixer to uniformly mix diatomite and nano powder to obtain modified diatomite; among them, the mass ratio of diatomite to nano powder is 1:1, the mixing time is 3 min, and the rotation speed is 400 rpm;

[0067] (4) By weight, uniformly mix 100 parts of polypropylene, 10 parts of modified diatomite, 1 part of antioxidant and 1 part of processing aid, and then melt extrude from a twin-screw extruder to obtain a low-odor polypropylene composite material for extruded pipes.

[0068] The odor level of the finally prepared low-odor polypropylene composite material for extruded pipes is 3, and the extruded pipes made of the low-odor polypropylene composite material for extruded pipes do not rupture.

[0069] Example 3

[0070] A preparation method of a low-odor polypropylene composite material for extruded pipes, the specific steps are as follows:

[0071] (1) Preparation of raw materials;

[0072] Nano calcium carbonate: Manufacturer is Quanzhou Xufeng Powder Material Co., Ltd., grade is NC-90A;

[0073] HDPE: Manufacturer is Daqing Petrochemical Company, PetroChina Company Limited, grade is 5000S;

[0074] Diatomite: Manufacturer is Shengzhou Huali Diatomite Products Co., Ltd., grade is CD08, pore diameter is 50 - 2500 nm;

[0075] Polypropylene: Manufacturer is Formosa Plastics Corporation, Taiwan, China, grade is 3015;

[0076] Antioxidant: Antioxidant 1010;

[0077] Processing aid: EBS;

[0078] (2) After uniformly mixing nano calcium carbonate and HDPE, melt extrude and grind to obtain nano powder with a particle size of 50 - 100 nm; among them, the mass ratio of nano calcium carbonate to HDPE is 1:1;

[0079] (3) Use a high-speed mixer to uniformly mix diatomaceous earth and nano powder to obtain modified diatomaceous earth; among them, the mass ratio of diatomaceous earth to nano powder is 1:2, the mixing time is 4 min, and the rotation speed is 400 rpm;

[0080] (4) By weight, uniformly mix 100 parts of polypropylene, 20 parts of modified diatomaceous earth, 1 part of antioxidant and 1 part of processing aid, and then melt extrude from a twin-screw extruder to obtain a low-odor polypropylene composite material for extruded pipes.

[0081] The odor level of the finally obtained low-odor polypropylene composite material for extruded pipes is 3, and the extruded pipes made of the low-odor polypropylene composite material for extruded pipes do not rupture.

[0082] Example 4

[0083] A preparation method of a low-odor polypropylene composite material for extruded pipes, the specific steps are as follows:

[0084] (1) Preparation of raw materials;

[0085] Nano calcium carbonate: The manufacturer is Quanzhou Xufeng Powder Raw Material Co., Ltd., and the grade is NC-90A;

[0086] HDPE: The manufacturer is Shandong Qilu Petrochemical Engineering Co., Ltd., and the grade is 1158P;

[0087] Diatomaceous earth: The manufacturer is Shengzhou Huali Diatomaceous Earth Products Co., Ltd., and the grade is CD09, with a pore diameter of 50 - 3000 nm;

[0088] Polypropylene: The manufacturer is China Petroleum & Chemical Corporation Shanghai Petrochemical Company Limited, and the grade is M180R;

[0089] Antioxidant: Antioxidant 168;

[0090] Processing aid: Calcium stearate;

[0091] (2) After uniformly mixing nano calcium carbonate and HDPE, melt extrude and grind to obtain nano powder with a particle size of 50 - 100 nm; among them, the mass ratio of nano calcium carbonate to HDPE is 1:2;

[0092] (3) Use a high-speed mixer to uniformly mix diatomaceous earth and nano powder to obtain modified diatomaceous earth; among them, the mass ratio of diatomaceous earth to nano powder is 1:3, the mixing time is 5 min, and the rotation speed is 400 rpm;

[0093] (4) By weight, 100 parts of polypropylene, 30 parts of modified diatomaceous earth, 1 part of antioxidant and 1 part of processing aid are mixed evenly and then melt-extruded from a twin-screw extruder to obtain a low-odor polypropylene composite material for extruded pipes.

[0094] The odor level of the finally obtained low-odor polypropylene composite material for extruded pipes is 3, and the extruded pipes made of the low-odor polypropylene composite material for extruded pipes do not rupture.

[0095] Example 5

[0096] A preparation method of a low-odor polypropylene composite material for extruded pipes, the specific steps are as follows:

[0097] (1) Preparation of raw materials;

[0098] Nano calcium carbonate: The manufacturer is Quanzhou Xufeng Powder Raw Material Co., Ltd., and the grade is NC-90A;

[0099] HDPE: The manufacturer is China Petroleum & Chemical Corporation Shanghai Petrochemical Company Limited, and the grade is SH400;

[0100] Diatomaceous earth: The manufacturer is Shengzhou Huali Diatomaceous Earth Products Co., Ltd., the grade is CD09, and the pore diameter is 50 - 3000 nm;

[0101] Polypropylene: The manufacturer is Dushanzi Petrochemical Company, PetroChina Company Limited, and the grade is K8003;

[0102] Antioxidant: Antioxidant 168;

[0103] Processing aid: Calcium stearate;

[0104] (2) After mixing nano calcium carbonate and HDPE evenly, melt-extrude and grind to obtain nano powder with a particle size of 50 - 100 nm; among them, the mass ratio of nano calcium carbonate to HDPE is 1:2;

[0105] (3) Use a high-speed mixer to mix diatomaceous earth and nano powder evenly to obtain modified diatomaceous earth; among them, the mass ratio of diatomaceous earth to nano powder is 1:1, the mixing time is 5 min, and the rotation speed is 400 rpm;

[0106] (4) By weight, 100 parts of polypropylene, 30 parts of modified diatomaceous earth, 1 part of antioxidant and 1 part of processing aid are mixed evenly and then melt-extruded from a twin-screw extruder to obtain a low-odor polypropylene composite material for extruded pipes.

[0107] The odor level of the finally obtained low-odor polypropylene composite material for extruded pipes is 2.5, and the extruded pipes made of the low-odor polypropylene composite material for extruded pipes do not rupture.

Claims

1. A low-odor polypropylene composite material for extruded pipes, characterized in that, By weight parts, it includes 100 parts of polypropylene and 8 - 30 parts of modified diatomite; The modified diatomite is obtained by mixing diatomite and nano - powder in a mass ratio of 1:1 - 3. The nano - powder is obtained by mixing nano - calcium carbonate and HDPE in a mass ratio of 1:1 - 2, followed by melt - extrusion and grinding.

2. The low-odor polypropylene composite material for extruded pipes according to claim 1, characterized in that, When mixing diatomite and nano - powder, a high - speed mixer is used, the mixing time is 3 - 5 min, and the mixing rotation speed is 400 rpm.

3. The low-odor polypropylene composite material for extruded pipes according to claim 1, wherein The diatomite has a porous structure with a pore diameter of 50 - 3000 nm.

4. The low-odor polypropylene composite material for extruded pipes according to claim 3, wherein, The particle size of the nano - powder is 50 - 100 nm.

5. The low-odor polypropylene composite material for extruded pipes according to claim 1, wherein, The melt index of polypropylene at 230 °C and 2.16 kg is 0.2 - 3 g / 10 min.

6. The low-odor polypropylene composite material for extruded pipes according to claim 1, wherein By weight parts, it also includes 1 part of antioxidant and 1 part of processing aid.

7. An odorless polypropylene composite material for extruded pipes according to any one of claims 1 to 6, characterized in that, The low - odor polypropylene composite material for extruded pipes has an odor grade of 3.0 measured according to the Volkswagen odor detection standard PV3900; for an extruded pipe made of the low - odor polypropylene composite material for extruded pipes, a section with a length of 50 cm is intercepted, both ends are sealed, and it is placed in water. After filling the section with gas, no bubbles are generated in the water.

8. A method for preparing a low-odor polypropylene composite material for extruded pipes according to any one of claims 1 to 7, characterized in that, After mixing each component evenly according to the ratio, it is melt - extruded from a twin - screw extruder to obtain the low - odor polypropylene composite material for extruded pipes.