CN113845731A - White polypropylene material capable of being marked by laser and preparation method and application thereof - Google Patents

Abstract

The invention discloses a white polypropylene material capable of being marked by laser, which comprises the following components in parts by weight: 900 portions and 990 portions of PP resin; 10-100 parts of white pigment; 0.01-0.1 part of toner mixture; the toner mixture is a mixture comprising acetylene black, ultramarine and ultramarine violet, wherein the acetylene black is 0.0002% -0.001%, the ultramarine is 0.001% -0.006%, the ultramarine violet is 0.002% -0.008%, and the total content of the ultramarine and the ultramarine violet is less than 0.01% based on the total weight of the polypropylene material. According to the invention, the white polypropylene material with high whiteness is prepared by adding the toner mixture consisting of the white pigment, the acetylene black, the ultramarine blue and the ultramarine violet, the laser marking of the white polypropylene material can show a yellow effect, the diversity of laser marking colors of the white polypropylene material is widened, the diversified appearance requirements of the market are met, and the white polypropylene material is free from adding a laser marking agent additionally and has economic cost.

Description

White polypropylene material capable of being marked by laser and preparation method and application thereof

Technical Field

The invention relates to the technical field of high polymer materials, in particular to a white polypropylene material capable of being marked by laser and a preparation method and application thereof.

Background

Polypropylene (PP) has the advantages of chemical resistance, heat resistance, electrical insulation, high-strength mechanical property, good high-wear-resistance processing property and the like, and is widely applied to the fields of automobiles, electronic and electric appliances, buildings, textiles, packaging, agriculture, forestry, fishery, food industry and the like. In practical applications, especially in the field of household appliances, in order to improve the identifiability and traceability of products, identification is usually performed on the surfaces of polypropylene products.

The laser marking is a marking method which utilizes high-energy-density laser to locally irradiate a workpiece so as to vaporize a surface layer material or generate a chemical reaction with color change, thereby leaving a permanent mark.

For white polypropylene materials, since white polypropylene does not substantially absorb laser beam energy, it cannot convert light energy into heat energy, and its laser marking performance is poor, generally only producing a faint, barely recognizable mark. The existing white polypropylene material capable of being marked by laser usually needs to be added with a laser marking agent, has high marking process parameter setting, can be marked with clear and identifiable marks, has limited marking effect and single color, can only show black marking effect, and cannot meet the diversified appearance requirements of the market.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a white polypropylene material which can be marked with clear yellow marks by laser without adding a laser marking agent additionally.

The invention also aims to provide a preparation method of the polypropylene material.

It is a further object of the present invention to provide the use of the polypropylene material described above.

The invention is realized by the following technical scheme:

a white polypropylene material capable of being marked by laser comprises the following components in parts by weight:

900 portions and 990 portions of PP resin;

10-100 parts of white pigment;

0.01-0.1 part of toner mixture;

the toner mixture is a mixture comprising acetylene black, ultramarine and ultramarine violet, wherein the acetylene black is 0.0002% -0.001%, the ultramarine is 0.001% -0.006%, the ultramarine violet is 0.002% -0.008%, and the total content of the ultramarine and the ultramarine violet is less than 0.01% based on the total weight of the polypropylene material.

The white pigment is selected from zinc sulfide.

According to research, a certain amount of zinc sulfide is added into polypropylene resin, and the zinc sulfide and a toner mixture consisting of acetylene black, ultramarine blue and ultramarine violet are cooperated to make a white polypropylene material mark yellow marks by laser. The zinc sulfide can enable the material to achieve higher whiteness, meanwhile, the zinc sulfide has certain transmission to infrared laser, energy is partially lost, the energy gathered on the surface of the PP material is reduced, the acetylene black, ultramarine blue and ultramarine blue toner mixture with certain content can adjust the shading degree and hue of the material, the pure positive of the white of the material is ensured, and the heat conductivity and the uniformity of the material are improved, so that the burning of the PP material by laser ablation can achieve a certain degree and is not thorough enough, and finally, clear yellow marking effect marks are displayed.

Generally, the white pigment is added in the amount required by the invention, namely the content of the white pigment is 1-10% based on the total weight of the polypropylene material, the material can have higher whiteness, and meanwhile, a better yellow laser marking effect can be realized; if the addition amount is too small, the whiteness of the material is low, and a yellow mark cannot be marked; if the addition amount is too much, the whiteness of the material is not obviously improved, the cost is increased, the marking effect is deteriorated, and the mechanical properties, particularly the impact strength, of the material are influenced. Preferably, the content of the white pigment is 2 to 8 percent based on the total weight of the polypropylene material; more preferably, the white pigment is present in an amount of 3% to 6% based on the total weight of the polypropylene material.

In order to ensure the whiteness of the material and better laser marking color presentation, preferably, based on the total weight of the polypropylene material, the content of the acetylene black is 0.0004 to 0.00085 percent, the content of the ultramarine blue is 0.002 to 0.004 percent, and the content of the ultramarine violet is 0.004 to 0.0065 percent.

More preferably, the acetylene black is contained in an amount of 0.0006% to 0.00075%, the ultramarine is contained in an amount of 0.0025% to 0.003%, and the ultramarine violet is contained in an amount of 0.005% to 0.006%, based on the total weight of the polypropylene material.

The invention mainly researches and uses the toner combination to improve the laser marking effect of the polypropylene material, and for PP resin, the effect of the invention can be realized by selecting homo-polypropylene or co-polypropylene.

According to the material performance requirement, the white polypropylene material capable of being marked by laser also comprises 1-5 parts of processing aid by weight; 2-6 parts of an antioxidant.

The processing aid is selected from any one or more of polyethylene wax, erucamide, ethylene bis stearamide or stearate; the antioxidant is selected from one or more of hindered phenol antioxidants or phosphite antioxidants. The invention has no requirement on the types and sources of the processing aid and the antioxidant, and technicians can select proper types of the processing aid and the antioxidant according to the requirements of actual conditions.

The invention also provides a preparation method of the white polypropylene material capable of being marked by laser, which comprises the following steps:

(1) adding the components into a high-speed mixer or an internal mixer according to the proportion and uniformly mixing to obtain a mixed material;

(2) and (2) feeding the mixed material obtained in the step (1) into an extruder or an internal mixer through a feeder, and mixing, extruding, cooling and granulating at the temperature of 60-220 ℃ to obtain the white polypropylene material capable of being marked by laser.

The invention also provides application of the white polypropylene material capable of being marked by laser in the field of household appliances.

Compared with the prior art, the invention has the following beneficial effects:

the invention researches and uses the toner combination to improve the laser marking performance of the polypropylene material, and the high-whiteness white polypropylene material capable of being marked by laser is prepared by adding the toner mixture consisting of white pigment, acetylene black, ultramarine blue and ultramarine violet, and the laser marking can show a yellow effect, thereby breaking the technical limitation that the traditional polypropylene material can only be marked by white and black during laser marking, widening the diversity of the laser marking colors of the white polypropylene material and meeting the diversified appearance requirements of the market.

The white polypropylene material capable of being marked by laser does not need to be additionally added with a laser marking agent, and is economical in cost.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way.

The raw materials used in the examples and comparative examples of the present invention are described below, but are not limited to these materials:

PP resin 1: copolypropylene, PP HP500N, medium sand;

PP resin 2: homo-polypropylene, PP T30S, daqing;

white pigment 1: zinc sulfide 1, universal energy recovery;

white pigment 2: zinc sulfide 2, hubei kunshun biotechnology limited;

white pigment 3: titanium dioxide, dupont;

white pigment 4: lithopone, pedicle blue chemical;

acetylene black: and the chemical industry is prosperous;

coloring carbon black: anhui black Yu pigment New Material Co., Ltd;

ultramarine: haigure;

ultramarine violet: haigure;

antioxidant: compounding an antioxidant 1010 and an antioxidant 168 according to the weight ratio of 1: 1;

processing aid: erucamide, commercially available.

Preparation of examples and comparative examples:

(1) adding the components into a high-speed mixer according to the proportion shown in the table 1 or the table 2, and uniformly mixing to obtain a mixed material;

(2) feeding the mixed material obtained in the step (1) into an extruder through a feeder, wherein the temperature is set as the following one region: 60 ℃, zone two: 160 ℃, three zones: 180 ℃, four zones: 200 ℃, five zones: 200 ℃, six zones: 210 ℃, seven zones: 200 ℃, zone 8: and (3) mixing, extruding, cooling and granulating at 220 ℃ to obtain the polypropylene material.

Table 1: example 1~10 Each component ratio (by weight parts)

	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6	Example 7	Example 8	Example 9	Example 10
											PP resin 1	990	980	970	940	920	900	970	970	/	950
PP resin 2	/	/	/	/	/	/	/	/	960	/
											White pigment 1	10	20	30	60	80	100	30	30	40	/
White pigment 2	/	/	/	/	/	/	/	/	/	50
											Acetylene black	0.003	0.003	0.003	0.003	0.003	0.003	0.006	0.0075	0.01	0.004
Ultramarine blue	0.01	0.01	0.01	0.01	0.01	0.01	0.02	0.025	0.035	0.015
											Ardisia purpurea (Var. Ceratopteris Fr.) Ohwi	0.02	0.02	0.02	0.02	0.02	0.02	0.04	0.05	0.05	0.03
Antioxidant agent	/	/	/	/	/	/	/	/	2	2
											Processing aid	/	/	/	/	/	/	/	/	2	2

Table 2: comparative examples 1 to 10 the proportions (in parts by weight) of the respective components

	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4	Comparative example 5	Comparative example 6	Comparative example 7	Comparative example 8	Comparative example 9	Comparative example 10
											PP resin 1	990	990	990	990	990	995	850	1000	990	990
White pigment 1	/	/	10	10	10	5	150	/	10	10
											White pigment 3	10	/	/	/	/	/	/	/	/	/
White pigment 4	/	10	/	/	/	/	/	/	/	/
											Acetylene black	0.003	0.003	/	0.03	0.003	0.003	0.003	0.003	/	0.003
Colored carbon black	/	/	0.003	/	/	/	/	/	/	/
											Ultramarine blue	0.01	0.01	0.01	0.01	0.1	0.01	0.01	0.01	0.01	/
Ardisia purpurea (Var. Ceratopteris Fr.) Ohwi	0.02	0.02	0.02	0.02	0.2	0.02	0.02	0.02	0.02	/

The polypropylene materials prepared in the above examples and comparative examples were injection molded into flat square plates (100 mm x 100 mm) by an injection molding machine; the injection molding machine is a horizontal extruder, and the injection molding temperature is 200 +/-5 ℃; and then, carrying out laser marking on the obtained square plate by using special infrared laser marking equipment for plastics, carrying out color test by using a color-Eye color measuring instrument, and analyzing the colors of the material and the marking font by using a Lab color model, wherein an L value represents the shade of the color (the larger the L value is, the higher the whiteness is, the better the whiteness of the material is more than 90), an a value represents the red and green color (the larger the a value is, the red is), a b value represents the yellow and blue color (the larger the b value is, the yellow is), and the test result is shown in a table 3/4.

Evaluation of yellow effect of marking characters: the larger the b value of the marking font is, the better the yellow phase of the marking font is (the better the yellow effect is), and when the L value is 60< L value <90 and the b value >7.0, the marking font can present obvious yellow.

Evaluating the definition of the marking characters: calculating the absolute value of lightness change | Delta L | = | L before and after marking material_Material－L_{Marking characters}The larger the | Δ L | value, the more marked the marking effect. The marking font definition is recognized by naked eyes, the more O, the higher the definition of the marking font is, the more X, the lower the definition of the marking font is, and the more fuzzy: (1) "OOO" means that the marking font is recognizable and very clear; (2) "OO" indicates that the marking font can be recognized and is clear; (3) the 'O' indicates that the marking characters can be identified and are clearer; (4) "X" indicates that the marking font is fuzzy and still recognizable; (5) "XX" indicates that the marking font is blurred and difficult to recognize.

Table 3: examples 1-10 test results of laser marking effect of polypropylene Material

Table 3 is shown below:

table 3 is shown below:

table 4: comparative example 1-10 polypropylene material laser marking effect test result

Table 4 is shown below:

table 4 is shown below:

as can be seen from the above examples and comparative examples, the white polypropylene material obtained by adding a certain amount of the white pigment and the toner mixture consisting of acetylene black, ultramarine blue and ultramarine violet has high whiteness (L value of color test reaches more than 90), clear laser marking font (lightness change | Delta L | before and after marking > 7), and good yellow effect of the marking color.

In comparison with examples 1 to 6, in a certain range, the higher the content of zinc sulfide, the higher the whiteness of the material (the higher the L value), and the higher whiteness and the better marking effect can be obtained at a content of 3%, at this time, the increase of the addition amount of zinc sulfide is not obvious to improve the whiteness of the material, and the higher addition amount of zinc sulfide adversely affects the marking effect.

Comparative example 1/2 compared with example 1, while comparative example 1 uses titanium dioxide, a white material with higher whiteness can be prepared, but the L value of the laser marking font is less than 30, the color is black, and the yellow effect cannot be presented; comparative example 2 Using lithopone, the material was low in whiteness and off-white, and the laser marked fonts had L values less than 30 and were black in color and did not exhibit a yellow effect.

Comparative example 3 compared with example 1, the use of colored carbon black instead of acetylene black was chosen to produce a material with low whiteness, off-white color, yellow contrast of laser marking fonts, gray yellow color, fuzzy marking fonts and poor definition.

Comparative example 4/5 compared to example 1, the toner mixture content was too high, the material whiteness was low, was light gray or light blue, and its laser marked font was yellow-contrast and the marked font was hazy and poorly defined.

Comparative example 6/7 the zinc sulfide content was either too low or too high to achieve a clear yellow marking compared to example 1.

Comparative example 8, no white pigment was added, the material was low in whiteness, and its laser marking font was gray in color and was indistinct.

Comparative example 9, a white material with higher whiteness was obtained without the addition of acetylene black, but the laser marked font was gray and indistinct.

Compared with the comparative example 10, the material is not added with ultramarine blue and ultramarine blue, has low whiteness and higher yellow phase, is yellow-white, can not meet the whiteness requirement of an appearance workpiece on a white material, and has fuzzy laser marking fonts and poor yellow phase, thereby showing a gray-yellow effect.

It will be appreciated by those of ordinary skill in the art that the examples provided herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited examples and embodiments. Those skilled in the art can make various other specific changes and combinations based on the teachings of the present invention without departing from the spirit of the invention, and these changes and combinations are within the scope of the invention.

Claims (10)

1. A white polypropylene material capable of being marked by laser is characterized by comprising the following components in parts by weight:

900 portions and 990 portions of PP resin;

10-100 parts of white pigment;

0.01-0.1 part of toner mixture;

the toner mixture is a mixture comprising acetylene black, ultramarine and ultramarine violet, wherein the acetylene black is 0.0002% -0.001%, the ultramarine is 0.001% -0.006%, the ultramarine violet is 0.002% -0.008%, and the total content of the ultramarine and the ultramarine violet is less than 0.01% based on the total weight of the polypropylene material.

2. The laser-markable white polypropylene material according to claim 1, wherein the white pigment is present in an amount of 1% to 10% based on the total weight of the polypropylene material; preferably, the content of the white pigment is 2 to 8 percent based on the total weight of the polypropylene material; more preferably, the white pigment is present in an amount of 3% to 6% based on the total weight of the polypropylene material.

3. The laser-markable white polypropylene material according to claim 1, wherein the white pigment is selected from zinc sulfide.

4. The laser markable white polypropylene material according to claim 1 wherein the acetylene black is present in an amount of 0.0004% to 0.00085%, the ultramarine blue is present in an amount of 0.002% to 0.004%, and the ultramarine violet is present in an amount of 0.004% to 0.0065%, based on the total weight of the polypropylene material.

5. The laser-markable white polypropylene material according to claim 1, wherein the acetylene black is present in an amount of 0.0006% to 0.00075%, the ultramarine blue is present in an amount of 0.0025% to 0.003%, and the ultramarine violet is present in an amount of 0.005% to 0.006%, based on the total weight of the polypropylene material.

6. The laser-markable white polypropylene material according to claim 1, wherein the PP resin is selected from any one or more of homo-polypropylene and co-polypropylene.

7. The laser-markable white polypropylene material according to claim 1, further comprising 1 to 5 parts by weight of a processing aid; 2-6 parts of an antioxidant.

8. The laser-markable white polypropylene material according to claim 7, wherein the processing aid is selected from any one or more of polyethylene wax, erucamide, ethylene bis-stearamide or stearate; the antioxidant is selected from one or more of hindered phenol antioxidants or phosphite antioxidants.

9. The method for preparing the white polypropylene material capable of being marked by laser according to any one of claims 1 to 8, which is characterized by comprising the following steps:

(1) adding the components into a high-speed mixer or an internal mixer according to the proportion and uniformly mixing to obtain a mixed material;

(2) and (2) feeding the mixed material obtained in the step (1) into an extruder or an internal mixer through a feeder, and mixing, extruding, cooling and granulating at the temperature of 60-220 ℃ to obtain the white polypropylene material capable of being marked by laser.

10. Use of a laser markable white polypropylene material according to any of the claims 1 to 8 in the field of household appliances.