A colored nylon composition and its preparation method and application

Abstract

This application relates to the field of polymer materials technology, specifically disclosing a colored nylon composition, its preparation method, and its application. The colored nylon composition comprises the following components by weight: 53-72 parts aliphatic PA resin, 3-12 parts transparent nylon, 25-35 parts modified glass fiber, 0.1-0.5 parts antioxidant, 0.3-1 parts lubricant, 0.3-1 parts light stabilizer, 0.5-1 parts colorant, and 1-3 parts metal halide. The modified glass fiber is a color-fixing agent-coated modified glass fiber. This application utilizes a technical solution combining transparent nylon, modified glass fiber, and metal halide to improve the grayscale level of the colored nylon composition and enhance the UV resistance of the colored material.

Description

Technical Field

[0001] The present application relates to the technical field of polymer materials, and in particular to a colored nylon composition, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous development of the economy in recent years, the automotive industry has gradually developed towards intelligence, networking, and comfort. At present, people have higher and higher requirements for automobile safety and comfort, and the requirements for automotive materials are also getting higher and higher. At the same time, the demand for material color is also increasing. Currently, in the field of automotive interiors and automotive connectors, black is no longer the mainstream color. More and more bright colors are gradually being presented to customers. Color stability has become an important research direction.

[0003] Nylon, also known as polyamide (PA), is a general term for thermoplastic resins containing repeating amide groups (-NHCO-) ​​in the main chain of the molecule. It includes aliphatic nylon, aromatic nylon, semi-aromatic nylon, and new varieties of specialty nylon. Nylon materials themselves have excellent mechanical properties and are widely used in the automotive industry. However, nylon materials themselves are prone to yellowing, and color-matched products are prone to discoloration under high temperature, light, and other environments. Colored nylons have poor UV resistance, and the UV resistance of colored nylon materials needs to be improved to meet the current automotive industry's requirements for grayscale levels of brightly colored plastic products. In addition, research on the color stability of nylon materials has primarily focused on the textile field. In the automotive industry, there has been more research on black or dark nylon products, while research on bright colors (orange, red, and blue) is relatively limited. This cannot meet the current requirements of automotive OEMs for UV-resistant colored nylon materials. Summary of the Invention

[0004] The purpose of this application is to overcome the shortcomings of the above-mentioned prior art and provide a colored nylon composition and its preparation method and application. The colored nylon composition prepared in this application has the advantages of good UV resistance and high grayscale, meeting the color and grayscale requirements of the main engine manufacturers.

[0005] To achieve the above objectives, the technical solutions adopted in this application are:

[0006] The present application provides a colored nylon composition, comprising the following components in parts by weight:

[0007] Aliphatic PA resin 53-72 parts, transparent nylon 3-12 parts, modified glass fiber 25-35 parts, antioxidant 0.1-0.5 parts, lubricant 0.3-1 parts, light stabilizer 0.3-1 parts, color powder 0.5-1 parts and metal halide 1-3 parts;

[0008] The modified glass fiber is a glass fiber modified by coating with a color fixing agent.

[0009] The present application adopts a technical solution combining transparent nylon, modified glass fiber, and metal halide to improve the grayscale level of the colored nylon composition and enhance the UV resistance of the colored material. The modified glass fiber is a glass fiber coated with a color fixing agent. The color fixing agent on the surface of the modified glass fiber contains many sulfonic acid groups that can combine with the amino groups of nylon, so that the prepared colored nylon composition has good compatibility. At the same time, the color fixing agent is coated on the fiber, and the color fixing agent acts like a bridge between the nylon and the glass fiber, making it difficult for the color powder to precipitate, thereby contributing to the improvement of the UV resistance of the colored nylon composition.

[0010] At the same time, the addition of transparent nylon and metal halide disrupts the crystallization of the aliphatic PA resin. Transparent nylon contains benzene rings, which restrict the movement of the nylon molecular chains in the colored nylon composition and hinder nylon crystallization. At the same time, the metal halide can form a complex with the nylon molecular chain, restricting the movement of the molecular chain, reducing the formation of hydrogen bonds between amide bonds, affecting the arrangement of the molecular chains into the crystal lattice, reducing the crystallinity of the aliphatic PA resin, and slowing crystallization. This helps more toner enter the amorphous region of the aliphatic PA resin and better disperse in the colored nylon composition, reducing toner precipitation during light aging, and helping to improve the UV resistance of the colored nylon composition.

[0011] In some specific embodiments, the mass percentage of the aliphatic PA resin in the colored nylon composition is not less than 48%.

[0012] As a preferred embodiment of the colored nylon composition described in the present application, the color fixing agent is an acidic color fixing agent, the color fixing agent is a high molecular weight aromatic sulfonic acid condensate, and the pH value of the color fixing agent is 6-7.

[0013] The color fixing agent of the present application is selected from high molecular weight aromatic sulfonic acid condensates, which can better improve the UV resistance of the colored nylon composition at the same time.

[0014] As a preferred embodiment of the colored nylon composition described in the present application, in the modified glass fiber, the weight ratio of the glass fiber to the color fixing agent is 100:(1-5).

[0015] Preferably, in the modified glass fiber, the weight ratio of the glass fiber to the color fixing agent is 100:(1-3) for modification, and the modified glass fiber can further improve the UV resistance of the colored nylon composition.

[0016] As a preferred embodiment of the colored nylon composition described in the present application, the average length of the glass fiber is 3 to 4.5 mm, and the average diameter of the glass fiber is 8 to 11 μm.

[0017] As a preferred embodiment of the colored nylon composition described in the present application, the relative viscosity of the aliphatic PA resin is 2.4 to 3.4, preferably 2.5 to 2.8.

[0018] The relative viscosity of aliphatic PA resin is determined according to ISO 307-2007. PA resin is dissolved in 96% concentrated sulfuric acid to prepare a 1% g / ml nylon solution, and then the viscosity of the material is tested using an Ubbelohde viscometer.

[0019] The present application uses the aliphatic PA resin with the above viscosity to prepare a colored nylon composition, which can effectively improve the grayscale level of the colored nylon composition.

[0020] As a preferred embodiment of the colored nylon composition described in the present application, the aliphatic PA resin includes at least one selected from polycaprolactam, polyhexamethylene adipamide, polydecamethylenediamine, polydodecanediamide and polyhexamethylenediamine.

[0021] As a preferred embodiment of the colored nylon composition described in the present application, the transparent nylon is PA6I polymerized from hexamethylenediamine and isophthalic acid, with a relative viscosity of 1.8-2.0.

[0022] The relative viscosity of transparent nylon is determined according to ISO 307-2007. PA resin is dissolved in 96% concentrated sulfuric acid to prepare a 1% g / ml nylon solution. The viscosity of the material is then tested using an Ubbelohde viscometer.

[0023] In the technical solution of the present application, transparent nylon is added to the colored nylon composition, which effectively improves the grayscale level of the colored nylon composition.

[0024] As a preferred embodiment of the colored nylon composition described in the present application, the metal halide includes calcium chloride.

[0025] As a preferred embodiment of the colored nylon composition described in the present application, the antioxidant is a hindered phenol antioxidant and / or a phosphite; the lubricant is at least one of silicones, esters, montanates, ethylene bisstearamide, and polyethylene wax;

[0026] The light stabilizer is a mixture of benzotriazoles and hindered amines. The combination of ultraviolet absorber and light stabilizer can effectively improve the UV resistance of the material. The mass ratio of ultraviolet absorber to light stabilizer is (0.8-1.2): (0.8-1.2), preferably a mass ratio of 1:1, such as a mixture of UV-234 and UV-944;

[0027] The toner is an acid dye, and the color of the toner can be selected from at least one of orange toner, yellow toner, red toner, and brown toner.

[0028] The acid dyes include azo acid dyes.

[0029] The present application also provides a method for preparing the colored nylon composition, comprising the following steps:

[0030] 1) mixing and diluting a color fixing agent and water to obtain a color fixing agent solution, spraying the color fixing agent solution onto the surface of the glass fiber, and then drying the glass fiber to obtain a modified glass fiber;

[0031] 3) Adding aliphatic PA resin, transparent nylon, antioxidant, lubricant, light stabilizer, color powder, and metal halide into a premixer and mixing to obtain a mixture;

[0032] 2) The mixed material is fed into a twin-screw extruder from a main feed port, and the modified glass fiber is added into the twin-screw extruder through a side feed, melted, extruded and granulated to obtain a colored nylon composition.

[0033] Preferably, in step 1), the drying temperature is 90-110° C., and the drying time is 12-16 hours.

[0034] The present application also provides the use of the above-mentioned colored nylon composition in wiring harnesses, bayonets, low-voltage connectors, high-voltage connectors, and electric control boxes and automotive accessories.

[0035] Compared with the prior art, this application has the following beneficial effects:

[0036] The present application provides a colored nylon composition, a preparation method, and an application thereof. The present application adopts a technical solution combining transparent nylon, modified glass fiber, and metal halide to improve the grayscale level of the colored nylon composition and enhance the UV resistance of the colored material. At the same time, the addition of transparent nylon and metal halide disrupts the crystallization of the aliphatic PA resin. The transparent nylon contains benzene rings, which restrict the movement of the nylon molecular chains in the colored nylon composition and hinder the nylon crystallization. At the same time, the metal halide forms a complex with the nylon molecular chain, restricting the movement of the molecular chain, reducing the formation of hydrogen bonds between amide bonds, affecting the arrangement of the molecular chains into the crystal lattice, reducing the crystallinity of the aliphatic PA resin, and slowing crystallization. This helps more toner enter the amorphous region of the aliphatic PA resin and better disperse in the colored nylon composition, reducing the precipitation of toner during light aging, and helping to improve the UV resistance and color of the colored nylon composition. DETAILED DESCRIPTION

[0037] In order to better illustrate the purpose, technical solutions and advantages of this application, this application will be further described below in conjunction with specific embodiments.

[0038] In the following examples and comparative examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0039] The sources of raw materials for the following examples and comparative examples are as follows:

[0040] PA6 resin 1: viscosity 2.5, from Haiyang Chemical Fiber, brand HY-2500A;

[0041] PA6 resin 2: viscosity 2.8, from Haiyang Chemical Fiber, brand HY2800A;

[0042] PA6 resin 3: viscosity 2.4, from polymer, brand J2400;

[0043] PA6 resin 4: viscosity 3.4, from Haiyang Chemical Fiber, brand HY-3400A;

[0044] Transparent nylon PA6I: from Shandong Dongchen Ruisen, brand TM01;

[0045] Transparent nylon PA6I / 6T: from Shandong Guangyin, brand TM126;

[0046] Glass fiber: from Jushi Glass Fiber, brand ECS10-03-568H;

[0047] Light stabilizer: a mixture of UV-234 and UV-944 (1:1), from BASF;

[0048] Metal halide: commercially available, calcium chloride;

[0049] Metal halide: commercially available, sodium chloride;

[0050] Fixing agent 1: high molecular weight aromatic sulfonic acid condensate, sourced from Suzhou Yisite, brand EST-506;

[0051] Fixing agent 2: quaternary ammonium salt fixing agent, from Jiande Baisha Chemical Co., Ltd., brand TD-2;

[0052] Antioxidant: Hindered phenol antioxidant, antioxidant 1010, from Lionlong, brand SONOX 1010;

[0053] Lubricant: silicone lubricant, commercially available, brand MB50-002;

[0054] Orange color powder: methyl orange, commercially available;

[0055] In the examples and comparative examples, transparent nylon, glass fiber, light stabilizer, antioxidant, lubricant, and orange toner are all the same commercially available products.

[0056] The preparation method of modified glass fiber comprises the following steps:

[0057] The fixing agent and dewatering agent are diluted in a weight ratio of 1:2, and then different diluted fixing agent solutions are evenly sprayed onto the surface of the glass fiber in different proportions (weight ratio of the fixing agent to the glass fiber). The glass fiber is then placed in an oven at 100°C and dried for 12-16 hours to prepare modified glass fibers, which are divided into modified glass fibers 1-5.

[0058] The mass ratio of modified glass fiber 1: fixing agent 1 and glass fiber is 1:100;

[0059] The mass ratio of modified glass fiber 2: fixing agent 1 and glass fiber is 2:100;

[0060] The mass ratio of modified glass fiber 3: fixing agent 1 and glass fiber is 3:100;

[0061] The mass ratio of modified glass fiber 4: fixing agent 1 and glass fiber is 5:100;

[0062] The mass ratio of modified glass fiber 5: fixing agent 2 and glass fiber is 1:100;

[0063] Examples 1-12: A colored nylon composition and its preparation method

[0064] Examples 1 to 12 provide a method for preparing a colored nylon composition. The weight ratio of the composition is shown in Table 1. The preparation method is as follows:

[0065] 1) Weigh the raw materials by weight;

[0066] 2) Aliphatic PA resin, transparent nylon, antioxidant, lubricant, light stabilizer, colorant, and metal halide are added to a premixer and mixed to obtain a mixture. The mixture is fed into a twin-screw extruder through the main feed port. Modified glass fiber (or glass fiber not treated with a color fixative) is side-fed into the twin-screw extruder. After pulling, cooling, pelletizing, and drying, a colored nylon composition is obtained. The twin-screw extruder is set at a temperature of 240-280°C, and the temperatures of the heating zones from the feed port to the die are set at 240, 250, 260, 265, 265, 270, 275, and 270, respectively. The screw speed is 300-400 rpm.

[0067] The preparation methods of Comparative Examples 1 to 4 are the same as those of Examples 1 to 12, and the weight proportions are shown in Table 2.

[0068] Table 1

[0069]

[0070]

[0071] Table 2

[0072] Group Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 PA6 resin 1 63 63 63 63 Transparent nylon 5 / 5 5 Modified glass fiber 1 30 30 30 fiberglass 30 antioxidants 0.2 0.2 0.2 0.2 lubricant 0.3 0.3 0.3 0.3 Light stabilizers 0.5 0.5 0.5 0.5 calcium chloride / 2 2 5 Orange toner 1 1 1 1

[0073] The performance of the colored nylon compositions prepared in Examples 1 to 12 and Comparative Examples 1 to 4 was tested, and the results are shown in Table 3.

[0074] Tensile strength: The sample was injection molded into a 170mm*10mm*4mm dumbbell-shaped specimen and tested according to ISO 527-2012 at a tensile rate of 5mm / min.

[0075] Charpy notched impact strength: The sample is injection molded into a 80mm*10mm*4mm spline with a notch thickness of 8mm. The test is performed according to ISO179-2020 with a pendulum energy of 4J.

[0076] UV resistance color evaluation (grayscale): Based on the requirements of automotive exteriors and in accordance with SAE J2527-2004, 50*70mm samples were prepared and placed in a xenon lamp aging chamber for 1000 hours of light aging. The color changes and color stability of the samples were then evaluated, and the changes in grayscale were recorded. The highest grayscale level is 5, and the lowest is 1. The higher the value, the smaller the color change after xenon lamp aging, indicating a more stable color.

[0077] Table 3

[0078] Group Tensile strength / MPa <![CDATA[Notch impact strength / KJ / m 2 > Grayscale Example 1 186 10.2 5.0 Example 2 190 10.6 4.5 Example 3 178 9.6 4.0 Example 4 180 9.8 4.0 Example 5 180 9.0 4.5 Example 6 181 9.2 4.5 Example 7 176 8.8 4.5 Example 8 175 8.8 4.0 Example 9 170 8.1 3.5 Example 10 180 8.3 4.0 Example 11 177 8.2 4.0 Example 12 188 9.8 4.0 Comparative Example 1 172 9 3.0 Comparative Example 2 165 8 2.5 Comparative Example 3 166 8.1 2.5 Comparative Example 4 173 8.0 3.0

[0079] From the results in Table 3, it can be seen that the grayscale grade of the colored nylon compositions prepared in Examples 1-12 is 3.5-5.0, the tensile strength is 170-190 MPa, and the notched impact strength is 8.1-10.6 KJ / m 2 The use of PA6 resins of different viscosities in Examples 1-4 has an impact on the grayscale of the colored nylon composition. When the PA6 resin of the corresponding viscosity in Example 1-2 is used, the grayscale of the colored nylon composition can be improved. The grayscale of the colored nylon composition of Example 1-2 is 4.5-5.0, and the grayscale of the colored nylon composition of Example 3-4 is 4.0. The effect of Example 1-2 is better than that of Example 3-4. At the same time, the mechanical properties of Example 1-2 are better, with a tensile strength of 186-190 MPa and a notched impact strength of 10.2-10.6 KJ / m 2 .

[0080] In Examples 5-7, the modified glass fibers formed by using different mass ratios of the color fixing agent 1 and the glass fibers have a significantly improved grayscale grade of the prepared colored nylon compositions, a tensile strength of 176-181 MPa, and a notched impact strength of 8.8-9.2 KJ / m 2 , indicating that the addition of fixing agent 1 can improve the UV resistance of the colored nylon composition; Example 8 uses fixing agent 2 to modify the glass fiber, and the UV resistance of the prepared colored nylon composition is not as good as that of Examples 5-7, but the mechanical properties are not much different.

[0081] Comparative Example 1 does not contain calcium chloride, and the grayscale level of the colored nylon composition is significantly reduced, indicating that the addition of the metal halide calcium chloride significantly improves the grayscale level of the material and enhances the UV resistance of the colored nylon composition.

[0082] Comparative Example 2 does not contain transparent nylon, and the grayscale level of the colored nylon composition prepared therefrom is relatively low, indicating that the addition of transparent nylon such as PA6I helps to improve the grayscale level of the material.

[0083] In Comparative Example 3, ordinary glass fiber was used, and the grayscale level of the colored nylon composition was significantly lower than that of the glass fiber modified with the color fixing agent.

[0084] In Comparative Example 4, the amount of calcium chloride in the colored nylon composition is excessive. Excessive CaCl2 reduces the crystallization of nylon. When the content is too high, it can destroy the hydrogen bond structure of nylon, restrict the movement of molecular chains, reduce material properties, and increase the difficulty of processing and dispersion. Therefore, the mechanical properties and grayscale grade of the colored nylon composition are lower than those of Example 1.

[0085] The present application adopts a technical solution combining transparent nylon, modified glass fiber, and metal halide to improve the grayscale level (3.5 to 5.0) of the colored nylon composition and enhance the UV resistance of the colored material. The modified glass fiber is a glass fiber coated with a color fixing agent. The color fixing agent on the surface of the modified glass fiber contains many sulfonic acid groups that can combine with the amino groups of nylon, so that the prepared colored nylon composition has good compatibility and forms a network structure, which makes it difficult for the color powder to precipitate, thereby helping to improve the UV resistance and color of the colored nylon composition.

[0086] At the same time, the addition of transparent nylon and metal chlorides disrupts the crystallization of the nylon material. Transparent nylon contains benzene rings, which restrict the movement of the nylon molecular chains in the colored nylon composition and hinder nylon crystallization. Calcium chloride also easily forms complexes with the nylon molecular chains, restricting their movement and reducing the formation of hydrogen bonds between amide bonds. This affects the arrangement of the molecular chains into the crystal lattice, reducing the crystallinity of the aliphatic PA resin and slowing crystallization. This helps more toner enter the amorphous region of the nylon material and better disperse in the colored nylon composition, reducing toner precipitation during light aging and helping to improve the UV resistance and color of the colored nylon composition.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A colored nylon composition, characterized in that: The composition comprises the following components in parts by weight: Aliphatic PA resin 53-72 parts, transparent nylon 3-12 parts, modified glass fiber 25-35 parts, antioxidant 0.1-0.5 parts, lubricant 0.3-1 parts, light stabilizer 0.3-1 parts, color powder 0.5-1 parts and metal halide 1-3 parts; The modified glass fiber is a glass fiber coated with a color fixing agent; The color fixing agent is an acidic color fixing agent, and the color fixing agent is a high molecular weight aromatic sulfonic acid condensate; The metal halide is calcium chloride or sodium chloride; The transparent nylon is PA6I or PA6I / 6T.

2. The colored nylon composition according to claim 1, wherein In the modified glass fiber, the weight ratio of the glass fiber to the color fixing agent is 100:(1-5).

3. The colored nylon composition according to claim 1, wherein The average length of the glass fiber is 3 to 4.5 mm, and the average diameter of the glass fiber is 8 to 11 μm.

4. The colored nylon composition according to claim 1, wherein The relative viscosity of the aliphatic PA resin is 2.4 to 3.4; The relative viscosity of the aliphatic PA resin is measured according to ISO 307-2007. The PA resin is dissolved in 96% concentrated sulfuric acid to prepare a 1% g / ml nylon solution, and then the viscosity of the material is tested using an Ubbelohde viscometer.

5. The colored nylon composition according to claim 4, wherein The relative viscosity of the aliphatic PA resin is 2.5-2.

8.

6. The colored nylon composition according to claim 4, wherein The aliphatic PA resin includes at least one selected from polycaprolactam, polyhexamethylene adipamide, polydecamethylene sebacamide, polyhexamethylene dodecanoamide and polyhexamethylene sebacamide.

7. The colored nylon composition according to claim 1, wherein The antioxidant is a hindered phenol antioxidant and / or a phosphite; the lubricant is at least one of silicones, esters, montanates, ethylene bisstearamide, and polyethylene wax; the light stabilizer is a mixture of benzotriazoles and hindered amines; and the toner is an acid dye.

8. A method for preparing the colored nylon composition according to any one of claims 1 to 7, characterized in that: The following steps are involved: 1) mixing and diluting a color fixing agent and water to obtain a color fixing agent solution, spraying the color fixing agent solution onto the surface of the glass fiber, and then drying the glass fiber to obtain a modified glass fiber; 2) Adding aliphatic PA resin, transparent nylon, antioxidant, lubricant, light stabilizer, color powder, and metal halide into a premixer and mixing to obtain a mixture; 3) The mixed material is fed into a twin-screw extruder from a main feed port, and the modified glass fiber is added into the twin-screw extruder through a side feed, melted, extruded and granulated to obtain a colored nylon composition.

9. Use of the colored nylon composition according to any one of claims 1 to 7 in wiring harnesses, bayonets, low-voltage connectors, high-voltage connectors, and electric control boxes and automotive accessories.

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