A nylon composition and its preparation method and application

Abstract

The present invention belongs to the technical field of polymer material coloring, and in particular relates to a nylon composition, a preparation method thereof, and an application thereof. Specifically, the present invention discloses a nylon composition comprising the following components, by weight: 93-99 parts of nylon; 0.02-0.05 parts of pigment red; 0.5-5 parts of PE; 0.5-10 parts of EVA; and 0.1-2 parts of an additive. The present invention can be used to prepare power tool parts, has the effect of avoiding the pigment-dyeing phenomenon caused by hydrogen bond interaction between the pigment particles and the amide bonds of the nylon, solves the fluorescence problem of the pigment in nylon, and achieves color restoration. The technical solution of the present application can significantly reduce the amount of pigment used, save color matching costs, significantly improve cost-effectiveness, and also broaden the application range of other colorants in polar plastics.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material coloring, and in particular relates to a nylon composition, a preparation method and an application thereof. Background Art

[0002] Nylon, also known as polyamide (PA), is a material with high strength, wear resistance, light weight, good insulation, high temperature resistance, and chemical corrosion resistance. These properties make nylon widely used in various fields. In the industrial field, nylon is used to manufacture mechanical parts such as bearings, gears, and pipes due to its high strength and wear resistance. In the electrical and electronic industry, nylon is used in wire and cable insulation, electrical switches, and other components due to its good insulation and high temperature resistance. In the construction industry, nylon is often used to make architectural decorations and sealing materials due to its weather resistance and easy processing. In the aerospace field, nylon is used to manufacture lightweight, high-strength components due to its lightweight and high-strength properties.

[0003] During the nylon processing process, pigments are often added for dyeing to meet the diverse needs of the market and consumers. Through dyeing, nylon products can obtain a variety of colors and patterns, thereby enhancing their beauty and appeal.

[0004] However, many pigments will produce hydrogen bond interactions with the amide bonds of nylon during processing and cause pigment-dye phenomenon, changing the color of the pigment and accompanied by strong fluorescence [J. Colloid Interface Sci, 1999, 216(1):189], resulting in a significant decrease in the weather resistance and color stability of plastic products. Therefore, the choice of pigments in colored nylon is greatly limited. Currently, the red pigments commonly used in nylon composition color matching are DPP pigments and perylene pigments. Although these two types of pigments have a great advantage in terms of molecular structure stability, they still cannot completely avoid the pigment-dye phenomenon. According to public information, dissolved DPP dye single molecules can promote molecular aggregation through stimulation methods such as mechanical force and thermal annealing, achieving color change and fluorescence quenching. However, in the field of plastic coloring, due to the influence of polymer chain segment movement, it is difficult for pigment / dye molecules in this environment to achieve structural transformation. DPP molecules dissolved in nylon need to be heat-treated at a high temperature of 180°C for 5 hours to achieve molecular aggregation and restore the original red color. This method has a great impact on the mechanical properties of nylon itself.

[0005] A Chinese patent application with publication number CN 109735102 A discloses a non-fluorescent red nylon material and a method for preparing the same. The application suppresses the fluorescence of red nylon by significantly increasing the amount of DPP pigment. The DPP amount needs to be increased to above 1.5 wt %. This DPP content can damage the material's properties, waste pigment, and increase costs.

[0006] The prior art lacks a red nylon composition that can reduce the amount of color powder added, ensures no fluorescence, and can quickly achieve reverse conversion from pigment to dye. Summary of the Invention

[0007] The object of the present invention is to solve the above technical problems and provide a red nylon composition with a small amount of toner added and no fluorescence.

[0008] Another object of the present invention is to provide a method for preparing the above-mentioned nylon composition.

[0009] Another object of the present invention is to provide applications of the above nylon composition.

[0010] The present invention is achieved through the following technical solutions:

[0011] A nylon composition, characterized in that it contains the following components in parts by weight:

[0012] 93-99 parts of nylon;

[0013] Pigment red 0.02-0.05 parts;

[0014] PE 0.5-5 parts;

[0015] EVA 0.5-10 parts;

[0016] The sum of the weight parts of PE and EVA is greater than or equal to 2 parts.

[0017] Preferably, the sum of the weight parts of PE and EVA is 2-5 parts.

[0018] Preferably, the PE is selected from any one or more of HDPE and LDPE; preferably HDPE.

[0019] Preferably, the weight ratio of PE:EVA is 1:(0.1-10); more preferably 1:(1-7), and even more preferably 1:(2-4).

[0020] Preferably, the weight average molecular weight of the PE is preferably 50,000-250,000, more preferably 60,000-200,000.

[0021] Preferably, the melting point of the PE is preferably 90°C-150°C, more preferably 100°C-135°C.

[0022] Preferably, the weight percentage of VA in the EVA is preferably 15%-45%.

[0023] Preferably, the nylon is selected from any one or more of nylon 6, nylon 66, nylon 56, nylon 612, nylon 510, and nylon 12, more preferably nylon 6 and nylon 66, and even more preferably nylon 6.

[0024] The relative viscosity of the nylon is preferably 2.30-37.00, the melting point is preferably 170-270°C, and the density is preferably 0.60-1.20 g / cm 3 .

[0025] Preferably, the pigment is selected from bis(p-chlorophenyl)-1,4-diketopyrrolopyrrole, 2,9-dimethyl-5,12-dihydroquinolin-[2,3-B]acridine-7,14-dione, 2,9-dichloro-5,12-dihydroquinolin-[2,3-B]acridine-7,14-dione, 1-(4-chloro-o-sulfonic acid-5-methylphenylazo)-2-naphthol barium salt, 3-hydroxy-4-[(4-methyl-2-sulfonic acid phenyl)azo]-2-naphthoic acid calcium salt, N,N'-1,4-phenylene-bis[4-(2,5-dichlorophenyl)azo]-3-hydroxynaphthalene-2-carboxylic acid Any one or more of amine, 2,9-bis[4-(phenylazo)phenyl]anthracene[2,1,9-def:6,5,10-d'e'f']diisoquinoline-1,3,8,10(2H,9H)-tetraone, preferably any one or more of bis(p-chlorophenyl)-1,4-diketopyrrolopyrrole, 2,9-bis[4-(phenylazo)phenyl]anthracene[2,1,9-def:6,5,10-d'e'f']diisoquinoline-1,3,8,10(2H,9H)-tetraone, more preferably bis(p-chlorophenyl)-1,4-diketopyrrolopyrrole.

[0026] When the amount of pigment red used is too small, the fluorescence will be enhanced and it will be more difficult to restore the color; although excessive use can suppress fluorescence to a certain extent and help color control, it will lead to a significant increase in costs and cause appearance defects such as color powder spots on the surface of the colored plastic. In addition, the impact of fluorescence on weather resistance cannot be ignored.

[0027] Those skilled in the art can add 0.1-2 parts by weight of an auxiliary agent according to actual needs; the auxiliary agent is selected from any one or more of an antioxidant, a lubricant, and a light stabilizer.

[0028] Preferably, the antioxidant is selected from any one or more of hindered phenol antioxidants and aromatic amine antioxidants, and the lubricant is selected from any one or more of esters or sodium tannate.

[0029] The present invention also provides a method for preparing the above-mentioned nylon composition, comprising the following steps:

[0030] S1: Dry the nylon thoroughly;

[0031] S2: mixing the components uniformly and extruding the nylon composition through a screw extruder;

[0032] S3: Packing the nylon composition into bags.

[0033] Preferably, the drying temperature in S1 is 110-120° C., and the drying time is 2-4 hours.

[0034] The present invention also provides application of the nylon composition for preparing electric tool parts.

[0035] The present invention has the following beneficial effects: PE and EVA form a melt to encapsulate the pigment, thereby reducing the contact between the pigment and nylon and avoiding the pigment-dye phenomenon caused by hydrogen bond interaction between the pigment particles and the amide bonds of the nylon; the low polarity of PE and EVA helps to reduce the solubility of the pigment in nylon; the lubricity of PE and EVA helps to increase the mobility of nylon chain segments and reduce the heterogeneous nucleation of pigment molecules and nylon; and EVA helps to adjust its compatibility in the nylon composition and prevent precipitation failure.

[0036] In addition to increasing the mobility of nylon chain segments through lubricity, PE and EVA can also promote the movement of nylon chain segments by affecting the thermal annealing temperature. PE and PA have poor compatibility, and adding only PE is detrimental to the mechanical properties of the nylon composition. Adding only EVA results in a system melting point below 100°C, which, while promoting movement, does not reach the optimal motion state for the nylon chain segments themselves.

[0037] Through the combined effect of PE powder and EVA, the fluorescence problem of pigments in nylon is solved and color restoration is achieved; the technical solution of the present application can greatly reduce the amount of pigments used, save color matching costs, achieve better results through the compounding of PE and EVA, while also reducing costs, significantly improving cost-effectiveness, and broadening the application range of other colorants in polar plastics. DETAILED DESCRIPTION

[0038] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0039] The raw materials used in the present invention are from:

[0040] Nylon 6: purchased from Jiangsu Haiyang Technology Co., Ltd., brand HY-2500A, relative viscosity 2.45±0.04, melting point 215-220℃, density 1.135-1.145g / cm 3 .

[0041] Nylon 66: purchased from INVISTA Nylon Chemical (China) Co., Ltd., brand PA66 U3200, relative viscosity 30.0-35.0, melting point 263°C, density 0.65-0.70 g / cm 3 .

[0042] Nylon 56: purchased from Shanghai Cathay Biotechnology Co., Ltd., brand E-6631, relative viscosity 2.37 ± 0.05, melting point 265 ± 3 °C, density 1.17 g / cm 3 .

[0043] Nylon 612: purchased from DuPont, brand Zytel-158, melting point 218°C, density 1.06 g / cm 3

[0044] Nylon 12: purchased from Shandong Dongchen Ruisen New Material Technology Co., Ltd., brand PA1212, melting point 178-185 °C, density 1.01-1.03 g / cm 3 .

[0045] PE1: HDPE, purchased from Dow Chemical, brand ELITE™ AT 6900, weight average molecular weight 200,000, melting point 134°C.

[0046] PE2: LDPE, purchased from Sinopec Chemical Sales (Guangdong) Co., Ltd., brand LDPE MG70, weight-average molecular weight 60,000, melting point 102°C.

[0047] EVA1: purchased from Taiwan Plastics Industry Co., Ltd., brand EVA 7350M, VA content 18%.

[0048] EVA2: purchased from Sinochem Quanzhou Petrochemical Co., Ltd., brand EVA UL00628, VA content 28%.

[0049] PP: purchased from CNOOC Shell Petrochemical Co., Ltd., brand PP EP548R, melting point 164-170℃, density 0.9g / cm 3 .

[0050] Pigment 1: Bis(p-chlorophenyl)-1,4-diketopyrrolopyrrole, purchased from BASF under the brand name Irgazin® RedK 3840 SQ (Pigment Red 254).

[0051] Pigment 2: 2,9-dimethyl-5,12-dihydroquinolin-[2,3-B]acridine-7,14-dione, purchased from Zhejiang Yongquan Chemical Co., Ltd., brand 122B (R203) (Pigment Red 122).

[0052] Pigment 3: 2,9-dichloro-5,12-dihydroquinolin-[2,3-B]acridine-7,14-dione, purchased from Titanium Sun Chemical, brand R252 (Pigment Red 202).

[0053] Pigment 4: 3-hydroxy-4-[(4-methyl-2-sulfonylphenyl)azo]-2-naphthoic acid calcium salt, purchased from Shenzhen Dingtai Chemical Co., Ltd., brand L4B (R216) (Pigment Red 57:1).

[0054] Pigment 5: N,N'-1,4-phenylene-bis[4-(2,5-dichlorophenyl)azo]-3-hydroxynaphthalene-2-carboxamide, purchased from BASF, brand K3540 (Pigment Red 166).

[0055] Pigment 6: 2,9-bis[4-(phenylazo)phenyl]anthracene[2,1,9-def:6,5,10-d'e'f']diisoquinoline-1,3,8,10(2H,9H)-tetraone, purchased from BASF, brand K3911 (Pigment Red 178).

[0056] Pigment 7: 1-(4-chloro-o-sulfonic acid-5-methylphenylazo)-2-naphthol barium salt, purchased from Shenzhen Tianlaibao Pigment Co., Ltd., brand Graphtol Red LC-CN09 (Pigment Red 53:1).

[0057] Antioxidant 1: purchased from Tianjin Li'anlong New Materials Co., Ltd., hindered phenol antioxidant, brand RIANOX1098.

[0058] Antioxidant 2: purchased from CBITEC, spirophosphite antioxidant, brand name REVONOX® 608.

[0059] Lubricant 1: available from Emery Oleochemicals, brand LOXIOL G 32.

[0060] Lubricant 2: available from Clariant, brand Licomont NAV101 PWD.

[0061] Light stabilizer: purchased from Cyanotec Surface Technology (Shanghai) Co., Ltd., brand CYASORB® UV-3808PP5.

[0062] The preparation method of the nylon composition of the embodiment and comparative example is as follows: the nylon is fully dried at a drying temperature of 120° C. for 2 hours; the components are uniformly mixed according to a ratio, and plastic particles are extruded through a screw extruder; and the plastic particles are packaged into bags.

[0063] Various test methods:

[0064] (1) Fluorescence intensity: Plastic particles were injection molded into color plates for testing. Fluorescence intensity was measured using a Horiba Jobin Yvon LabRAMHR800 fluorescence spectrometer, with the slit set to 1 nm, the excitation wavelength to 400 nm, and the color plate positioned at 45°.

[0065] (2) Hue: Plastic particles are injection molded into color plates for testing. Hue is measured using an X-rite Color-Eye 7000A spectrophotometer. Hue h represents color information, that is, the position of the spectral color. This parameter is expressed as an angle, ranging from 0 to 360°: starting from red and counting counterclockwise, red is 0°, green is 120°, and blue is 240°. Their complementary colors are: yellow is 60°, cyan is 180°, and violet is 300°. The smaller the value, the redder the color.

[0066] (3) Two-month outdoor simulated weathering test color difference: Place the color plates evenly in the aging box and use 0.80 W / (m 2 Artificial weathering tests were conducted using a xenon lamp with an irradiation intensity of 100 nm for two months. Samples were collected every seven days for color testing. Color difference (∆E) was measured using a spectrophotometer (X-rite Color-Eye 7000A).

[0067] Table 1: Weight parts of each component of nylon composition and test results of Examples 1-10

[0068]

[0069] It can be seen from Examples 4-9 that when nylon 6 is used as nylon, the prepared nylon composition has better performance in the three test results of fluorescence intensity, hue, and color difference of simulated weathering test.

[0070] It can be seen from Examples 4 and 10 that when HDPE is selected as PE, the prepared nylon composition has better performance in various performance tests.

[0071] Table 2: Weight of each component of nylon composition of Examples 11-20 and test results

[0072]

[0073] It can be seen from Examples 4 and 11-14 that the present application can achieve better results by adding a small amount of PE and EVA.

[0074] It can be seen from Examples 4 and 15-20 that the present application is versatile in terms of pigment selection, and the choice of specific pigments has little impact on the technical effect of achieving non-fluorescence in the present application.

[0075] Table 3: Weight parts of each component of nylon composition of comparative examples 1-4 and test results

[0076]

[0077] Comparative Example 1 only adds PE without adding EVA, and the sum of the weight parts of PE and EVA does not reach 2 parts. Its fluorescence intensity is greater than 0.4, and its hue is greater than 35. The color difference of the simulated weathering test is greater than 20.

[0078] It can be seen from Comparative Example 2 that by replacing EVA with PP, the test results of the nylon composition are within an acceptable error range, and PP has no effect on achieving the technical effects of the present application.

[0079] Comparative Example 3 is a blank control group without adding PE and EVA.

[0080] Comparative Example 4, in which the pigment addition level was 0.01, showed significant differences in all three test results compared to Example 4. This indicates that the lower limit of pigment addition significantly impacts fluorescence intensity, hue, and color difference in the simulated weathering test. This is presumably due to the aggregation and reddening of pigment red. When the pigment red addition level is low, the pigment red is largely dissolved in the resin. Therefore, the lower the addition level, the stronger the fluorescence, making color restoration more difficult.

Claims

1. A nylon composition, characterized in that By weight, it contains the following ingredients: 93-99 parts of nylon; Pigment red 0.02-0.05 parts; PE 0.5-5 parts; EVA 0.5-10 parts; The sum of the weight parts of PE and EVA is greater than or equal to 2 parts; The pigment red is selected from bis(p-chlorophenyl)-1,4-diketopyrrolopyrrole, 2,9-dimethyl-5,12-dihydroquinolin-[2,3-B]acridine-7,14-dione, 2,9-dichloro-5,12-dihydroquinolin-[2,3-B]acridine-7,14-dione, 1-(4-chloro-o-sulfonic acid-5-methylphenylazo)-2-naphthol barium salt, 3-hydroxy-4-[(4-methyl- Any one or more of: calcium salt of [2-sulfonic acid phenyl)azo]-2-naphthoic acid, N,N'-1,4-phenylene-bis[4-(2,5-dichlorophenyl)azo]-3-hydroxynaphthalene-2-carboxamide, and 2,9-bis[4-(phenylazo)phenyl]anthracene[2,1,9-def:6,5,10-d'e'f']diisoquinoline-1,3,8,10(2H,9H)-tetraone.

2. A nylon composition according to claim 1, characterized in that: The PE is selected from any one or more of HDPE and LDPE.

3. A nylon composition according to claim 2, characterized in that: The PE is selected from HDPE.

4. A nylon composition according to claim 1, characterized in that: The weight ratio of PE:EVA is 1:(0.1-10).

5. A nylon composition according to claim 4, characterized in that: The weight ratio of PE:EVA is 1:(1-7).

6. A nylon composition according to claim 5, characterized in that: The weight ratio of PE:EVA is 1:(2-4).

7. The nylon composition according to claim 1, characterized in that: The nylon is selected from any one or more of nylon 6, nylon 66, nylon 56, nylon 612, nylon 510, and nylon 12.

8. A nylon composition according to claim 7, characterized in that: The nylon is selected from nylon 6 and nylon 66.

9. A nylon composition according to claim 8, characterized in that: The nylon is selected from nylon 6.

10. The nylon composition according to claim 1, characterized in that: The pigment red is selected from any one or more of bis(p-chlorophenyl)-1,4-diketopyrrolopyrrole and 2,9-bis[4-(phenylazo)phenyl]anthracene[2,1,9-def:6,5,10-d'e'f']diisoquinoline-1,3,8,10(2H,9H)-tetraone.

11. A nylon composition according to claim 10, characterized in that: The pigment red is selected from bis(p-chlorophenyl)-1,4-diketopyrrolopyrrole.

12. The nylon composition according to claim 1, characterized in that: The invention further comprises 0.1-2 parts of auxiliary agents by weight; the auxiliary agents are selected from any one or more of antioxidants, lubricants and light stabilizers.

13. A nylon composition according to claim 12, characterized in that: The antioxidant is selected from any one or more of hindered phenol antioxidants and aromatic amine antioxidants, and the lubricant is selected from any one or more of esters and sodium tannate.

14. The method for preparing a nylon composition according to any one of claims 1 to 13, characterized in that: The following steps are involved: S1: Dry the nylon thoroughly; S2: mixing the components uniformly and extruding the nylon composition through a screw extruder; S3: Packing the nylon composition into bags.

15. The preparation method according to claim 14, characterized in that The drying temperature in S1 is 110-120°C and the drying time is 2-4 hours.

16. Use of a nylon composition according to any one of claims 1 to 13, characterized in that: Used to prepare power tool components.

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