1. The black master batch for the biodegradable plastic is characterized by comprising the following raw materials in parts by weight:

30-60 parts of carbon black;

20-40 parts of polyethylene resin;

5-10 parts of a lubricant;

1-3 parts of an antioxidant;

1-5 parts of a dispersing agent.

2. The black master batch for biodegradable plastics according to claim 1, which is prepared from the following raw materials in parts by weight:

45 parts of carbon black;

30 parts of polyethylene resin;

7 parts of a lubricant;

2 parts of an antioxidant;

3 parts of a dispersing agent.

3. The black master batch for biodegradable plastics according to claim 1, wherein: the carbon black has a diameter of less than 20 microns.

4. The black master batch for biodegradable plastics according to claim 1, wherein: the dispersing agent adopts polyethylene low molecular wax.

5. The method for preparing the black master batch for the biodegradable plastics according to claim 1, which is characterized by comprising the following steps:

step 1, placing 40 parts of carbon black and 30 parts of polyethylene resin into a high-speed stirrer, heating to 120 ℃, and stirring for 5-10 min;

step 2, after stirring, sequentially adding 7 parts of lubricant, 2 parts of antioxidant and 3 parts of dispersant, and stirring for 1-3min at the temperature of 120-130 ℃;

step 3, putting the uniformly stirred materials into a double-screw extruder, stirring for 10-30min in the environment with the rotating speed of 100-;

step 4, cutting the plastic strips into black master batches after cooling;

and 5, putting the black master batch and water into a separation barrel, carrying out solid-liquid separation, and filtering to remove impurities to finally obtain the black master batch.

Background

As is well known, with the rapid development of social economy, the requirements of various industries on plastic products are higher and higher, and the application range of the plastic products is rapidly expanded. At present, plastic base materials on the market are mainly classified into general plastics, engineering plastics and special plastics according to purposes, wherein the general plastics have very wide purposes due to the characteristics of high yield, good formability, high cost performance and the like. Polyethylene and polypropylene are used as common general plastics, have great similarity in properties and purposes, can be used as plastic films, injection molding products, plastic pipes and the like, and are also used as matrix resins for preparing various color master batches due to good compatibility with similar resins.

For example, the patent publication "CN 103709660A" is named as: the patent of ' a PBT black master batch and a preparation method thereof ' discloses ' the invention discloses a PBT black master batch and a preparation method thereof. The PBT black master batch comprises the following components in percentage by mass: 10 to 20 percent of PBT resin, 30 to 60 percent of carbon black, 10 to 40 percent of filler, 3 to 5 percent of dispersant, 0.5 to 3 percent of coupling agent and 0.1 to 1 percent of antioxidant. The black master batch prepared by the invention has the beneficial effects of good blackness, good dispersibility, small using amount, low cost, simple process, convenient use, environmental pollution avoidance and the like when being applied to PBT coloring. The preparation method provided by the invention is simple and practical, and has a wide application prospect.

The existing PBT black master batch and the preparation method thereof find that the black master batch has poor oxidation resistance, is inconvenient to produce and manufacture, does not remove impurities, and has poor product quality, so that the application limitation is high.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides the black master batch which is used for biodegradable plastics and has strong oxidation resistance and convenient processing and the preparation method thereof.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: a black master batch for biodegradable plastics is composed of the following raw materials in parts by weight:

30-60 parts of carbon black;

20-40 parts of polyethylene resin;

5-10 parts of a lubricant;

1-3 parts of an antioxidant;

1-5 parts of a dispersing agent.

The invention has the improvement that the invention is composed of the following raw materials by weight:

45 parts of carbon black;

30 parts of polyethylene resin;

7 parts of a lubricant;

2 parts of an antioxidant;

3 parts of a dispersing agent.

In an improvement of the present invention, the carbon black has a diameter of less than 20 microns.

The invention improves that the dispersant adopts polyethylene low molecular wax.

The invention further provides a preparation method of the black master batch for biodegradable plastics, which comprises the following steps:

step 1, placing 40 parts of carbon black and 30 parts of polyethylene resin into a high-speed stirrer, heating to 120 ℃, and stirring for 5-10 min;

step 2, after stirring, sequentially adding 7 parts of lubricant, 2 parts of antioxidant and 3 parts of dispersant, and stirring for 1-3min at the temperature of 120-130 ℃;

step 3, putting the uniformly stirred materials into a double-screw extruder, stirring for 10-30min in the environment with the rotating speed of 100-;

step 4, cutting the plastic strips into black master batches after cooling;

and 5, putting the black master batch and water into a separation barrel, carrying out solid-liquid separation, and filtering to remove impurities to finally obtain the black master batch.

(III) advantageous effects

Compared with the prior art, the invention provides the black master batch for the biodegradable plastic and the preparation method thereof, and the black master batch has the following beneficial effects:

according to the black master batch for the biodegradable plastic and the preparation method thereof, during preparation, raw materials are uniformly stirred and are fully combined, the black master batch has good oxidation resistance, and the product quality is good after filtration and impurity removal.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The first embodiment is as follows:

30 parts of carbon black;

20 parts of polyethylene resin;

5 parts of a lubricant;

1 part of an antioxidant;

1 part of a dispersant.

The preparation method comprises the following steps:

step 1, placing 30 parts of carbon black and 20 parts of polyethylene resin into a high-speed stirrer, heating to 120 ℃, and stirring for 5-10 min;

step 2, after stirring, sequentially adding 5 parts of lubricant, 1 part of antioxidant and 1 part of dispersant, and stirring for 1-3min at the temperature of 120-130 ℃;

step 3, putting the uniformly stirred materials into a double-screw extruder, stirring for 10-30min in the environment with the rotating speed of 100-;

step 4, cutting the plastic strips into black master batches after cooling;

and 5, putting the black master batch and water into a separation barrel, carrying out solid-liquid separation, and filtering to remove impurities to finally obtain the black master batch.

Example two:

45 parts of carbon black;

30 parts of polyethylene resin;

7 parts of a lubricant;

2 parts of an antioxidant;

3 parts of a dispersing agent.

The preparation method comprises the following steps:

step 1, placing 40 parts of carbon black and 30 parts of polyethylene resin into a high-speed stirrer, heating to 120 ℃, and stirring for 5-10 min;

step 2, after stirring, sequentially adding 7 parts of lubricant, 2 parts of antioxidant and 3 parts of dispersant, and stirring for 1-3min at the temperature of 120-130 ℃;

step 3, putting the uniformly stirred materials into a double-screw extruder, stirring for 10-30min in the environment with the rotating speed of 100-;

step 4, cutting the plastic strips into black master batches after cooling;

and 5, putting the black master batch and water into a separation barrel, carrying out solid-liquid separation, and filtering to remove impurities to finally obtain the black master batch.

Example three:

60 parts of carbon black;

40 parts of polyethylene resin;

10 parts of a lubricant;

3 parts of an antioxidant;

5 parts of a dispersing agent.

The preparation method comprises the following steps:

step 1, placing 60 parts of carbon black and 40 parts of polyethylene resin into a high-speed stirrer, heating to 120 ℃, and stirring for 5-10 min;

step 2, after stirring, sequentially adding 10 parts of lubricant, 3 parts of antioxidant and 5 parts of dispersant, and stirring for 1-3min at the temperature of 120-130 ℃;

step 3, putting the uniformly stirred materials into a double-screw extruder, stirring for 10-30min in the environment with the rotating speed of 100-;

step 4, cutting the plastic strips into black master batches after cooling;

and 5, putting the black master batch and water into a separation barrel, carrying out solid-liquid separation, and filtering to remove impurities to finally obtain the black master batch.

According to the test, the method comprises the following steps:

	example one	Example two	EXAMPLE III
				Carbon black dispersibility	< 2 th level	< 2 th level	< 2 th level
Melt index	25g/10min	30g/10min	37g/10min
				Colouring	Uniformity	Uniformity	Uniformity

In summary, the black master batch for the biodegradable plastic and the preparation method thereof have the advantages that the proportion of the carbon black to the polyethylene resin is large, the larger the melt index is, the more uniform the dispersibility of the carbon black is, the more stable the coloring is, and the good performance is realized.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.