PA6 resin composite material as well as preparation method and application thereof

Abstract

The invention relates to a PA6 resin composite material as well as a preparation method and application thereof. The PA6 resin composite material is prepared from the following components in parts by weight: 40 to 90 parts of PA6 resin, 30 to 51 parts of glass fiber and 0.4 to 3.1 parts of epoxy resin. The glass fiber is added, and the intrinsic viscosity of the PA6 resin and the epoxy equivalent of the epoxy resin are regulated and controlled within a specific range, so that the obtained PA6 resin composite material has good freezing liquid aging resistance and flame retardance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and more specifically, to a PA6 resin composite material, a preparation method thereof, and an application thereof. Background Art

[0002] Nylon has a wide range of applications in water chambers, pipe joints, etc. of automotive cooling systems. Since these parts are in direct contact with the coolant and are in a relatively high operating temperature for a long time, high requirements are placed on hydrolysis resistance. Currently, the main material used is PA66 material.

[0003] PA6 has excellent processing performance and low cost, but its water absorption rate is higher than that of PA66, resulting in poor hydrolysis resistance. In addition, the coolant contains alcohol, which easily causes alcoholysis of PA6. Coupled with the high operating temperature (about 100°C), the combined effects make the anti-aging performance of PA6 in coolant poor, and it is difficult to replace PA66 for application in the above scenarios. If a PA6 material with anti-aging performance in coolant can be developed, it can further meet the development of the automotive industry.

[0004] In addition, as a component of an automobile, from a safety perspective, the nylon material is also required to have certain flame retardant properties. Summary of the Invention

[0005] The primary object of the present invention is to overcome the problem of poor anti-aging performance of PA6 materials in the current technology and provide a PA6 resin composite material.

[0006] A further object of the present invention is to provide a preparation method of the above PA6 resin composite material.

[0007] A further object of the present invention is to provide an application of the above PA6 resin composite material in the preparation of automotive cooling system parts.

[0008] The above objects of the present invention are achieved by the following technical solutions:

[0009] A PA6 resin composite material, comprising the following components in parts by weight:

[0010] 40 - 90 parts of PA6 resin,

[0011] 30 - 51 parts of glass fiber,

[0012] 0.4 - 3.1 parts of epoxy resin;

[0013] The relative viscosity of the PA6 resin is 3.2 - 4.5;

[0014] The epoxy equivalent of the epoxy resin ≤ 350 g / eq.

[0015] In the present invention, the relative viscosity of the PA6 resin can be measured under the condition of 96% concentrated sulfuric acid in accordance with ISO 307-2019.

[0016] The epoxy equivalent of the epoxy resin of the present invention can be measured according to the method of GB / T 4612-2008.

[0017] In the present invention, the addition of glass fiber can improve the strength of the PA6 resin composite material and is helpful to improve its resistance to freezing fluid aging.

[0018] The inventor of the present invention found through research that by selecting a PA6 resin with a specific relative viscosity (3.2 to 4.5) and adding an epoxy resin with a specific epoxy equivalent, the resistance of the PA6 resin composite material to freezing fluid aging can be effectively improved. The principle is that the PA6 resin with this specific relative viscosity has relatively good degradation resistance, and its terminal amino group and / or terminal carboxyl group can form a sufficient cross-linked structure with the epoxy resin with a specific epoxy equivalent, effectively resisting the molecular chain breakage caused by alcoholysis due to the freezing fluid, thereby significantly improving the resistance of the PA6 resin composite material to freezing fluid aging.

[0019] The relative viscosity of the PA6 resin cannot be too low, otherwise its molecular chain is easily degraded under the action of water, alcohol and high temperature, and the resistance of the PA6 resin composite material to freezing fluid aging is poor; the relative viscosity of the PA6 resin cannot be too high, otherwise the activity of its terminal amino group and / or terminal carboxyl group is insufficient to form a sufficient cross-linked structure to resist alcoholysis. The epoxy equivalent of the epoxy resin cannot be too high, otherwise the formed cross-linked structure is not sufficient to resist the reduction of the molecular chain caused by the freezing fluid environment, resulting in almost no improvement in the resistance to freezing fluid aging.

[0020] In addition, the inventor of the present invention also found that the combination of a PA6 resin with a specific relative viscosity (3.2 to 4.5) and an epoxy resin with a specific epoxy equivalent can improve the flame retardancy of the PA6 resin composite material.

[0021] In the present invention, the dosage of the PA6 resin can specifically be 40, 42, 45, 48, 50, 52, 55, 58, 60, 62, 65, 68, 70, 72, 75, 78, 80, 82, 85, 88 or 90 parts by weight; the dosage of the glass fiber can specifically be 30, 35, 38, 40, 42, 45, 48, 50 or 51 parts by weight; the dosage of the epoxy resin can specifically be 0.4, 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.2, 2.5, 2.8, 3.0 or 3.1 parts by weight.

[0022] In the present invention, as the main resin, the content of the PA6 resin accounts for more than 30 wt% of the PA6 resin composite material.

[0023] In the present invention, the relative viscosity of the PA6 resin may specifically be 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4 or 4.5.

[0024] Preferably, the content of terminal amino groups and / or terminal carboxyl groups of the PA6 resin is 60 Meq / kg or more, more preferably 60 - 110 Meq / kg. The content of terminal amino groups and terminal carboxyl groups of the PA6 resin can be measured according to the standard of GB / T38138 - 2019.

[0025] In the present invention, the epoxy equivalent of the epoxy resin may specifically be 100, 120, 150, 170, 200, 220, 250, 280, 300, 320, 340 or 350 g / eq.

[0026] Preferably, the epoxy equivalent of the epoxy resin is 100 - 350 g / eq.

[0027] Preferably, the epoxy equivalent of the epoxy resin is 160 - 260 g / eq. By selecting the epoxy resin within this epoxy equivalent range, the PA6 resin composite material has better resistance to freezing fluid aging.

[0028] Preferably, the mass percentage of the epoxy resin in the PA6 resin composite material is 0.45 - 3.00%.

[0029] More preferably, the mass percentage of the epoxy resin in the PA6 resin composite material is 1.15 - 2.90%. Within this mass range, the PA6 resin composite material has better resistance to freezing fluid aging.

[0030] Preferably, the epoxy resin includes but is not limited to at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin or phenolic type epoxy resin.

[0031] Preferably, the glass fiber is chopped glass fiber.

[0032] Preferably, the elastic modulus of the glass fiber is ≥75 GPa, more preferably 75 - 95 GPa.

[0033] The elastic modulus of the glass fiber can be measured according to ASTM E1876 - 15.

[0034] Preferably, the average cross-sectional diameter of the glass fiber is 6 - 15 μm.

[0035] Preferably, the average length of the glass fiber is 2 - 6 mm.

[0036] In the present invention, the average cross-sectional diameter and average length of the glass fiber can be measured by the optical microscope method.

[0037] Preferably, the PA6 resin composite further comprises 0.1 - 2 parts of other additives.

[0038] More preferably, the other additives are at least one of a colorant, a lubricant or an antioxidant.

[0039] Optionally, the colorant is a black colorant, including but not limited to carbon black.

[0040] Optionally, the lubricant includes but is not limited to ester lubricants, including but not limited to at least one of EBS, stearamide or erucamide.

[0041] Optionally, the antioxidant is at least one of antioxidant 1010, antioxidant 1018 and antioxidant 168.

[0042] The preparation method of the above PA6 resin composite comprises the following steps: mixing each component, melt-extruding, and pelletizing to obtain the PA6 resin composite.

[0043] Preferably, the temperature of the melt-extrusion is 180 - 240 °C; the length-diameter ratio of the screw of the extruder for the melt-extrusion is 40 - 48:1, and the rotation speed of the screw is 400 - 800 r / min.

[0044] The application of the above PA6 resin composite in the preparation of an automotive cooling system is also within the protection scope of the present invention.

[0045] An automotive cooling system component is made of the above PA6 resin composite.

[0046] Preferably, the automotive cooling system component is a water chamber or a pipe joint.

[0047] Preferably, the automotive cooling system component is a component in contact with the coolant; the coolant is an alcohol aqueous solution; the volume ratio of alcohol to water in the alcohol aqueous solution is 0.8 - 1.2:1; the alcohol is ethylene glycol.

[0048] Compared with the prior art, the beneficial effects of the present invention are:

[0049] The present invention adds glass fiber and regulates the intrinsic viscosity of the PA6 resin and the epoxy equivalent of the epoxy resin within a specific range, and the obtained PA6 resin composite has good antifreeze aging performance and flame retardant performance. Detailed implementation manners

[0050] To more clearly and completely describe the technical solution of the present invention, the following further details the present invention through specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Various changes can be made within the scope defined by the claims of the present invention.

[0051] The descriptions of some of the reagents selected for each embodiment and comparative example of the present invention are as follows:

[0052] PA6 Resin 1#: The manufacturer is Xinhui Meida, the grade is M3400, and the relative viscosity is 3.4;

[0053] PA6 Resin 2#: The manufacturer is BASF, and the grade is B40 01, and the relative viscosity is 4.0;

[0054] PA6 Resin 3#: The manufacturer is Xinhui Meida, the grade is M2800, and the relative viscosity is 2.8;

[0055] PA6 Resin 4#: The manufacturer is Baling Petrochemical, the grade is BL5400H, and the relative viscosity is 5.4;

[0056] Epoxy Resin 1#: The manufacturer is Westlake, and the grade is EPON TM Resin 834, bisphenol A type, and the epoxy equivalent is about 250 g / eq;

[0057] Epoxy Resin 2#: The manufacturer is Westlake, and the grade is EPON TM Resin 161, phenolic type, and the epoxy equivalent is about 170 g / eq.

[0058] Epoxy Resin 3#: The manufacturer is Westlake, and the grade is EPON TM Resin 8021, bisphenol A type, and the epoxy equivalent is about 320 g / eq;

[0059] Epoxy Resin 4#: The manufacturer is Westlake, and the grade is EPON TM Resin 1001-B-80, bisphenol A type, and the epoxy equivalent is about 500 g / eq;

[0060] Epoxy Resin 5#: The manufacturer is Westlake, and the grade is EPON TM Resin 1002F, bisphenol A type, and the epoxy equivalent is about 650 g / eq;

[0061] Phenolic resin crosslinking agent: Bakelite PF 2400, Hexion;

[0062] Glass fiber: China National Bluestar (Group) Co., Ltd., E7CS10-03-568H glass fiber chopped strand; average length is 3 mm, average diameter of the cross-section is 10 μm, elastic modulus is 90 GPa;

[0063] Other additive 1#: ethylene bisstearamide, lubricant, commercially available;

[0064] Other additive 2#: pentaerythritol tetrakis [β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], antioxidant, commercially available;

[0065] Other additive 3#: colorant, carbon black, commercially available.

[0066] Unless otherwise specified, the components selected in each parallel example and comparative example (such as glass fiber, other additive 1#, other additive 2#) are all the same commercially available products.

[0067] The PA6 resin composites of the examples and comparative examples of the present invention are prepared by the following preparation method:

[0068] (1) Weigh each component according to the ratio, put each component into a high-speed mixer, and mix evenly to obtain a mixture.

[0069] (2) Put the mixture into a twin-screw extruder. The temperatures of each zone of the extruder are set as follows: 180 °C, 220 °C, 230 °C, 240 °C, 230 °C, 230 °C, 220 °C, 220 °C, 220 °C, 210 °C, the rotation speed is 400 r / min, and the screw length-diameter ratio is 40:1; after mixing, melting, and homogenizing, it is extruded and pelletized to obtain the PA6 resin composite.

[0070] The PA6 resin composites provided by each example and comparative example of the present invention are subjected to performance determination according to the following test methods:

[0071] Freezing fluid aging resistance test: Test the initial tensile strength of the tensile specimen and the tensile strength of the tensile specimen after freezing fluid aging treatment. The process of freezing fluid aging treatment is as follows: Put the tensile specimen into an autoclave, add an ethylene glycol solution (the volume ratio of ethylene glycol to water is 50:50), seal it, and put it into an oven at 120 °C for 500 h, and then test the tensile strength. Divide the tensile strength of the tensile specimen after freezing fluid aging treatment by the initial tensile strength of the tensile specimen to obtain the tensile strength retention rate. The higher the tensile strength retention rate, the better the freezing fluid aging resistance performance.

[0072] Flame retardant performance: According to the UL94 standard, horizontal and vertical combustion tests are carried out respectively, with a thickness of 1.6 mm, and the experimental results are recorded.

[0073] Examples 1-9

[0074] Examples 1 to 9 provide a series of PA6 resin composites, and their formulations are shown in Table 1.

[0075] Table 1 Formulations of Examples 1 to 9 (parts by weight)

[0076]

[0077]

[0079] Comparative Examples 1 to 6

[0080] Comparative Examples 1 to 6 provide a series of PA6 resin composites, and their formulations are shown in Table 2.

[0081] Table 2 Formulations of Comparative Examples 1 to 6 (parts by weight)

[0082]

[0084] The properties of the PA6 resin composites of each example and comparative example were measured according to the above-mentioned test methods, and the test results are shown in Table 3.

[0085] Table 3 Test Results of the Properties of the PA6 Resin Composites of Each Example and Comparative Example

[0086] Test results Freezing fluid aging resistance test Flame retardancy Example 1 86％ V2 Example 2 80％ V2 Example 3 85％ V2 Example 4 92％ V2 Example 5 93％ V2 Example 6 80％ V2 Example 7 79％ V2 Example 8 91％ V2 Example 9 94％ V2 Comparative example 1 38％ V2 Comparative example 2 41％ HB Comparative example 3 37％ HB Comparative example 4 35％ HB Comparative example 5 30％ HB Comparative example 6 42％ HB

[0087] As can be seen from Table 3:

[0088] The tensile strength retention rates of the PA6 resin composites of Examples 1 to 9 in the antifreeze aging test are all 79% or above, and the flame retardant properties are all V-2, indicating that the PA6 resin composites of the present invention have good antifreeze aging properties and flame retardant properties.

[0089] The viscosity of the PA6 resin added in Comparative Example 1 is too low, and the antifreeze aging of the PA6 resin composite is poor. The viscosity of the PA6 resin added in Comparative Example 2 is too high, and the properties of the PA6 resin composite are poor. The epoxy equivalent of the epoxy resin added in Comparative Examples 3 and 4 is too large, Comparative Example 5 does not add epoxy resin, and Comparative Example 6 adds other cross-linking agents, and the properties of the PA6 resin composite are all poor.

[0090] Obviously, the above examples of the present invention are merely illustrations for clearly explaining the present invention, and are not limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A PA6 resin composite material, characterized in that, Comprising the following components in parts by weight: 40 - 90 parts of PA6 resin, 30 - 51 parts of glass fiber, 0.4 - 3.1 parts of epoxy resin; The relative viscosity of the PA6 resin is 3.2 - 4.5; The epoxy equivalent of the epoxy resin is ≤350 g / eq.

2. The PA6 resin composite material according to claim 1, wherein The relative viscosity of the PA6 resin is 3.9 - 4.

1.

3. The PA6 resin composite material according to claim 1, wherein The epoxy equivalent of the epoxy resin is 100 - 350 g / eq.

4. The PA6 resin composite material according to claim 1, wherein The elastic modulus of the glass fiber is ≥75 GPa.

5. The PA6 resin composite material according to claim 1, wherein The PA6 resin composite further comprises 0.1 - 2 parts of other additives.

6. The PA6 resin composite material according to claim 1, wherein The other additives are at least one of a colorant, a lubricant or an antioxidant.

7. The preparation method of the PA6 resin composite material according to any one of claims 1 to 6, characterized in that, Comprising the following steps: mixing the components, melt - extruding, and pelletizing to obtain the PA6 resin composite.

8. Use of the PA6 resin composite according to any one of claims 1 - 6 in the preparation of automotive cooling system parts.

9. An automotive cooling system component, characterized in that, Prepared from the PA6 resin composite according to any one of claims 1 - 6.

10. The automotive cooling system component according to claim 9, characterized in that, The automotive cooling system part is a part in contact with the coolant; the coolant is an alcohol - aqueous solution; the volume ratio of alcohol to water in the alcohol - aqueous solution is 0.8 - 1.2:1; the alcohol is ethylene glycol.

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