High-fastness color-marked laser-engravable polypropylene material and preparation method thereof

Abstract

The invention discloses a high-fastness color-marked laser-engravable polypropylene material and a preparation method thereof, and belongs to the technical field of high polymer material modification. The high-fastness color-marked laser-engravable polypropylene material is prepared from the following raw materials in parts by mass: 100 parts of polypropylene resin, 2 parts of a laser absorbent, 0.5-1.5 parts of carbon black, 0.3 part of a weather-resistant agent, 1 part of a scratch-resistant agent, 0.6-1.4 parts of a color coloring agent, 0.3 part of an antioxidant and 0.3 part of a lubricating agent, the laser absorbent is polystyrene grafted antimony trioxide; by means of the specific ratio of the carbon black and the color coloring agent and the self-made laser absorbent, color marks with high fastness can be carved, and excellent scratch resistance and weather resistance are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material modification, and in particular relates to a high-fastness color-marked laser-engravable polypropylene material and a preparation method thereof. Background Art

[0002] With the development of polymer materials, product patterns (trademarks, anti-counterfeiting marks, QR codes, etc.) are particularly important. At present, the patterns on the surface of products are mostly made using technologies such as ink and screen printing. However, these methods have problems such as high cost, organic solvent pollution, and long curing cycle. Laser marking is a new type of surface pattern technology. It uses the physical and chemical changes of polymer materials under the irradiation of lasers of a certain wavelength and energy to produce micro-nanostructure patterns on the surface of the material. However, the market is still dominated by light-colored and dark-colored marks, with fewer colored marks, and the contrast of the marks is not high, so they are easy to scratch off. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a high-fastness color-marked laser-engravable polypropylene material and a preparation method thereof, thereby solving the problems in the prior art.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A laser-engravable polypropylene material comprises the following raw materials in parts by weight:

[0006]

[0007]

[0008] The laser absorber is polystyrene grafted with antimony trioxide.

[0009] Furthermore, polystyrene grafted antimony trioxide is prepared by free radical polymerization, wherein the grafting rate of antimony trioxide is 2-5%.

[0010] Furthermore, the polypropylene resin is metallocene random copolymer PP, and the melt flow rate under the test conditions of 230° C. and 2.16KG is 5-20g / 10min.

[0011] Furthermore, the color colorant is one or more of yellow powder, green powder, blue powder and red powder.

[0012] Furthermore, the carbon black is one or more of acetylene black, conductive carbon black, channel black or furnace black.

[0013] Furthermore, the weathering agent is selected from hindered amines or hindered benzoates.

[0014] Furthermore, the anti-scratch agent is selected from amides or silicones.

[0015] Furthermore, the lubricant is selected from at least one of silicone, zinc stearate and calcium stearate.

[0016] The above-mentioned method for preparing a laser-engravable polypropylene material comprises the following steps:

[0017] Evenly mix the acrylic resin, laser absorber, carbon black, colorant, weathering agent, scratch resistant agent, antioxidant and lubricant according to parts by mass;

[0018] The mixed material is melt-extruded and granulated through a twin-screw extruder.

[0019] Furthermore, the process parameters of the twin-screw extruder are as follows: the temperature of zone one is 170-190°C, the temperature of zone two is 190-210°C, the temperature of zone three is 210-230°C, the temperature of zone four is 220-240°C, the temperature of zone five is 210-230°C, the temperature of zone six is ​​220-240°C, the temperature of zone seven is 220-240°C, the temperature of zone eight is 220-240°C, the die head temperature is 220-240°C, the screw speed is 200-500rpm, and the vacuum degree is -0.05-0.08MPa.

[0020] Beneficial effects of the present invention:

[0021] 1. The polypropylene material capable of high-fastness color marking and laser engraving of the present invention can be engraved with high-fastness color marking through a specific ratio of carbon black and color colorant and a homemade laser absorber, and has excellent scratch resistance and weather resistance.

[0022] 2. The present invention does not need to add additional laser engraving additives. Through a specific color powder ratio and a homemade laser absorber, a color mark can be directly formed, which has a great cost advantage. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solution of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] A high-fastness color-marked laser-engravable polypropylene material, comprising the following raw materials in parts by weight:

[0025]

[0026] The polypropylene resin is a metallocene random copolymer PP, which has the advantages of high transparency and low precipitation, and a melt flow rate of 5-20 g / 10 min under the test conditions of 230° C. and 2.16 kg.

[0027] The laser absorber is polystyrene grafted antimony trioxide. The addition of antimony trioxide (Sb2O3) can promote PP's absorption of laser energy. The more energy the material absorbs, the more heat is converted. Among them, styrene grafted antimony trioxide is prepared by free radical polymerization, and the grafting rate of antimony trioxide is 2-5%.

[0028] The color colorant is one or more of yellow powder, green powder, blue powder and red powder;

[0029] The carbon black is one or more of acetylene black, conductive carbon black, channel black or furnace black;

[0030] The weathering agent is selected from hindered amines (HALS) or hindered benzoates;

[0031] The scratch-resistant agent is selected from amides or silicones;

[0032] The lubricant is selected from at least one of silicone, zinc stearate and calcium stearate.

[0033] The preparation process of the high-fastness color-marked laser-engravable polypropylene material includes:

[0034] S1, mixing propylene resin, laser absorber, carbon black, colorant, weathering agent, scratch resistant agent, antioxidant and lubricant uniformly according to weight parts;

[0035] S2, the mixed material is melt-extruded and granulated by a twin-screw extruder;

[0036] Among them, the process parameters of the twin-screw extruder are as follows: the temperature of zone 1 is 170-190°C, the temperature of zone 2 is 190-210°C, the temperature of zone 3 is 210-230°C, the temperature of zone 4 is 220-240°C, the temperature of zone 5 is 210-230°C, the temperature of zone 6 is 220-240°C, the temperature of zone 7 is 220-240°C, the temperature of zone 8 is 220-240°C, the die head temperature is 220-240°C, the screw speed is 200-500rpm, and the vacuum degree is -0.05-0.08MPa;

[0037] The ratio L / D of the screw length L and the diameter D of the twin-screw extruder is 35-50; the screw is provided with more than 1-2 meshing block areas and more than 1-2 reverse thread areas.

[0038] The following examples are used to illustrate the preparation method of the fastness color-marked laser-engravable polypropylene material of the present invention. The sources of the raw materials in the examples and comparative examples are as follows:

[0039] The polypropylene resin is metallocene random copolymer PP, and the melt flow rate is 5-20 g / 10 min under the test conditions of 230° C. and 2.16 KG.

[0040] Laser absorber: polystyrene grafted antimony trioxide (homemade).

[0041] Color colorant 1 is selected from GR red, color colorant 2 is selected from 114 yellow, and color colorant 3 is selected from 5B green.

[0042] The carbon black is selected from channel carbon black;

[0043] The weathering agent is selected from hindered amine 770, purchased from BASF, Germany;

[0044] The scratch-resistant agent is mesoamide, purchased from Tianjin Lianlong;

[0045] The antioxidants were a mixture of antioxidant 1010 and antioxidant 168 in a ratio of 1:3, purchased from Jinhai Yabao;

[0046] Calcium stearate was selected as the lubricant and was purchased from Zibo Ruifeng Plastic Additive Factory.

[0047] The raw material ratios in Examples 1-3 and Comparative Examples 1-3 are shown in Table 1 below:

[0048] Table 1 Raw material ratios of Examples 1-3 and Comparative Examples 1-3

[0049] Components Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Polypropylene resin 100 100 100 100 100 100 Laser absorber 2 2 2 2 2 2 Carbon Black 0.5 1 1.5 1.5 1.5 1.5 Color colorant 1 0.2 0.5 0.7 0.7 0.7 Color colorant 2 0.5 0.1 0.5 0.5 0.5 Color colorant 3 0.2 0.2 0.2 Weathering agent 0.3 0.3 0.3 0.1 0.3 Scratch resistant agent 2 1 1 1 1 1 Antioxidants 0.3 0.3 0.3 0.3 0.3 0.3 Lubricants 0.3 0.3 0.3 0.3 0.3 0.3

[0050] The method for preparing the polypropylene material in Examples 1-3 and Comparative Examples 1-3 comprises the following steps:

[0051] S1, according to the raw material ratio in Table 1, propylene resin, laser absorbent, carbon black, color colorant, weathering agent, scratch resistant agent, antioxidant, and lubricant are mixed uniformly using a high-speed mixer, and the speed of the high-speed mixer is 1200 rpm; wherein, no weathering agent is added in Comparative Example 2, and no color colorant is added in Comparative Example 3;

[0052] S2, adding the mixed raw materials into a parallel twin-screw extruder through a main feeder, and melt-extruded and granulated by the twin-screw extruder, the process parameters are as follows: the temperature of zone 1 is 170°C, the temperature of zone 2 is 210°C, the temperature of zone 3 is 210°C, the temperature of zone 4 is 220°C, the temperature of zone 5 is 210°C, the temperature of zone 6 is 220°C, the temperature of zone 7 is 220°C, the temperature of zone 8 is 220°C, the die head temperature is 220°C, the screw speed is 500rpm, and the vacuum degree is -0.05MPa;

[0053] Under the above process conditions, a twin-screw extruder is used for melt extrusion and granulation to obtain a granular polypropylene material for preparing a high-fastness color-marked laser-engravable material.

[0054] The linear expansion coefficient of the laser-engravable polypropylene material obtained in Examples 1-3 and Comparative Examples 1-3 was tested according to the following standards;

[0055] The test standards are as follows:

[0056] 1) The tensile strength was tested using dumbbell-shaped strips in GB / T1040 “Determination of Tensile Properties of Plastics” with a total length L0 of 170 mm, a length L1 of the narrow parallel portion of 80 mm, an end width b2 of 20 mm, a narrow portion width b1 of 10 mm, and a thickness of 4 mm at a test speed of 50 mm / min.

[0057] 2) The flexural strength and modulus were tested using a strip with a length of 80 mm, a width of 10 mm, and a thickness of 4 mm at a span of 64 mm and a test speed of 2 mm / min in accordance with GB / T9341 “Determination of Flexural Properties of Plastics”.

[0058] 3) Impact strength GB / T1843 "Determination of cantilever beam impact strength of plastics" uses a length of 80mm, a width of 10mm, a thickness of 4mm, and an A-notched spline for testing at a pendulum energy of 2.75J.

[0059] The colorimeter is used to evaluate the laser engraving clarity by measuring the change in the △L value of the marking area. The clarity is marked as 1, 2, 3, and 4 from poor to good. The weather resistance standard is in accordance with DIN EN ISO 4892-2:2013.

[0060] The performance test results are shown in Table 2;

[0061] Table 2 Performance test results of polypropylene materials prepared in Examples 1-3 and Comparative Examples 1-3

[0062] performance Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Tensile Strength 28 27 26 27 28 26 Bending Strength 30 29 27 28 32 29 Flexural modulus 1200 1300 1100 1300 1250 1150 Impact strength 5.5 5.2 4.5 5.5 5.2 4.8 Laser engraving clarity 4 4 4 3 3 3 Laser Engraving Color red yellow green green green gray Weather resistance △E 1.2 1.5 1.3 3.2 1.4 0.98 Scratch Resistant DE 2.1 2.8 3.4 3.2 2.9 3.0

[0063] From the data in the above table, it can be seen from Examples 1-3 that the present invention can carve clear color laser engraving marks under the action of laser through a specific color powder ratio and a self-made laser absorber; by comparing the data of Example 1 with that of Comparative Example 1, the generated color mark has excellent scratch resistance and weather resistance.

[0064] In summary, the high-fastness color-marked laser-engravable polypropylene material of the present invention can be engraved with color marks under the action of laser, and has excellent scratch resistance and weather resistance.

[0065] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0066] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A laser-engravable polypropylene material, characterized in that: Including the following raw materials by mass: The laser absorber is polystyrene grafted with antimony trioxide.

2. The laser-engravable polypropylene material according to claim 1, characterized in that: The polystyrene grafted antimony trioxide is prepared by free radical polymerization, wherein the grafting rate of antimony trioxide is 2-5%.

3. The laser-engravable polypropylene material according to claim 1, characterized in that: The polypropylene resin is a metallocene random copolymer PP, and has a melt flow rate of 5-20 g / 10 min under the test conditions of 230° C. and 2.16 kg.

4. The laser-engravable polypropylene material according to claim 1, characterized in that: The color colorant is one or more of yellow powder, green powder, blue powder and red powder.

5. The laser-engravable polypropylene material according to claim 1, characterized in that: The carbon black is one or more of acetylene black, conductive carbon black, channel black or furnace black.

6. The laser-engravable polypropylene material according to claim 1, characterized in that: The weathering agent is selected from hindered amines or hindered benzoates.

7. The laser-engravable polypropylene material according to claim 1, characterized in that: The anti-scratch agent is selected from amides or silicones.

8. The laser-engravable polypropylene material according to claim 1, characterized in that: The lubricant is selected from at least one of silicone, zinc stearate and calcium stearate.

9. The method for preparing a laser-engravable polypropylene material according to any one of claims 1 to 8, characterized in that: The following steps are involved: Evenly mix the acrylic resin, laser absorber, carbon black, colorant, weathering agent, scratch resistant agent, antioxidant and lubricant according to parts by mass; The mixed material is melt-extruded and granulated through a twin-screw extruder.

10. The method for preparing a laser-engravable polypropylene material according to claim 9, characterized in that: The process parameters of the twin-screw extruder are as follows: the temperature of zone one is 170-190°C, the temperature of zone two is 190-210°C, the temperature of zone three is 210-230°C, the temperature of zone four is 220-240°C, the temperature of zone five is 210-230°C, the temperature of zone six is ​​220-240°C, the temperature of zone seven is 220-240°C, the temperature of zone eight is 220-240°C, the die head temperature is 220-240°C, the screw speed is 200-500rpm, and the vacuum degree is -0.05-0.08MPa.

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