Low-water-absorption nylon material as well as preparation method and application thereof

Abstract

The invention discloses a low-water-absorption nylon material which comprises 45-85 parts of polyamide, 10-55 parts of glass fibers, 0.1-5 parts of carboxylic acid modified filler and 0.5-5 parts of a coupling agent. The invention further provides a preparation method and application of the low-water-absorption nylon material. According to the low-water-absorption nylon material provided by the invention, the balance water absorption of the nylon material can be effectively reduced by adding a small amount of the modified filler, and the mechanical property of the nylon material can be improved, so that the nylon material has excellent strength and rigidity.

Description

Technical Field

[0001] The present invention relates to the technical field of nylon material preparation, and particularly to a low water absorption nylon material, a preparation method thereof, and an application thereof. Background Art

[0002] Nylon is an engineering plastic with early development and large production. It has characteristics such as high mechanical strength, wear resistance, corrosion resistance, and good processing fluidity, and has excellent properties. Therefore, it is widely used in fields such as automobiles, chemical engineering, machinery, and precision instruments.

[0003] However, due to the presence of amide bonds (-NHCO-) on the nylon molecular chain, it has strong hydrophilicity. The higher the content of amide bonds, the greater the water absorption rate of nylon. The mechanical properties and physical properties of the water-absorbed nylon products will be affected, and even deformation will occur, seriously affecting the service life and safety of the products. Summary of the Invention

[0004] In view of the above deficiencies in the prior art, the present invention provides a low water absorption nylon material. By adding a small amount of modified filler, the equilibrium water absorption rate of the nylon material can be effectively reduced, and the mechanical properties of the nylon material can be improved, making it have excellent strength and stiffness.

[0005] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0006] A low water absorption nylon material, comprising 45 - 85 parts of polyamide, 10 - 55 parts of glass fiber, 0.1 - 5 parts of carboxylic acid modified filler, and 0.5 - 5 parts of coupling agent.

[0007] According to one aspect of the present invention, the polyamide is nylon 6 or nylon 66.

[0008] According to one aspect of the present invention, the carboxylic acid modified filler is a highly polar organic filler containing hydroxyl and carboxyl groups.

[0009] According to one aspect of the present invention, the carboxylic acid modified filler molecule chain simultaneously contains multiple carboxyl groups and hydroxyl groups, and the molecular weight is between 84 - 260.

[0010] According to one aspect of the present invention, the low water absorption nylon material further comprises any one or a combination of toughening agents, antioxidants, and / or lubricants.

[0011] According to one aspect of the present invention, the toughening agent is 0.1 - 1 part.

[0012] According to one aspect of the present invention, the antioxidant is 0.01 - 5 parts.

[0013] According to one aspect of the present invention, the lubricant is 0.01 - 5 parts.

[0014] According to one aspect of the present invention, the preparation method of the above low water absorption nylon material comprises the following steps:

[0015] Melt and blend the components and extrude them.

[0016] According to one aspect of the present invention, the extrusion is carried out by melt blending and extruding with a twin-screw extruder. The temperature settings of the screw from zone 1 to zone 14 of the twin-screw extruder are as follows: the temperature of zone 1 is 30 - 230 °C, the temperature of zone 2 is 50 - 250 °C, the temperature of zone 3 is 80 - 260 °C, the temperature of zone 4 is 200 - 260 °C, the temperature of zone 5 is 200 - 260 °C, the temperature of zone 6 is 200 - 260 °C, the temperature of zone 7 is 200 - 260 °C, the temperature of zone 8 is 200 - 260 °C, the temperature of zone 9 is 200 - 260 °C, the temperature of zone 10 is 200 - 260 °C, the temperature of zone 11 is 210 - 280 °C, the temperature of zone 12 is 210 - 280 °C, the temperature of zone 13 is 210 - 280 °C, and the temperature of zone 14 is 210 - 280 °C.

[0017] According to one aspect of the present invention, the above low water absorption nylon material is used in automobiles, chemical industry, machinery, and precision instruments.

[0018] Advantages of the implementation of the present invention:

[0019] 1. The modified filler is a highly polar organic filler containing hydroxyl and carboxyl groups. When the modified filler is melt blended and extruded with glass fiber and nylon, the hydroxyl groups on the modified filler combine with the coupling agent, enabling the glass fiber to be evenly dispersed in the nylon matrix; the remaining hydroxyl and carboxyl groups on the modified filler form hydrogen bonds with the amide bonds of nylon, which can effectively inhibit the water absorption of the nylon material. Therefore, the addition of the modified filler can not only make the combination of the glass fiber and the nylon matrix closer, but also effectively reduce the water absorption rate of the material without the need to additionally add anti-moisture absorption aids.

[0020] 2. Due to the addition of the modified filler, the combination of the glass fiber and the nylon matrix becomes closer, so the mechanical properties of the material are further improved, with excellent strength and stiffness, and the water absorption rate is lower than that of ordinary nylon materials and other types of glass fiber reinforced nylon materials.

[0021] 3. The preparation of the low water absorption nylon material adopts a twin-screw extrusion process, which is simple and can reduce production costs. Specific embodiments

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] A low water absorption nylon material, comprising 45 - 85 parts of polyamide, 10 - 55 parts of glass fiber, 0.1 - 5 parts of carboxylic acid modified filler, and 0.5 - 5 parts of coupling agent.

[0024] In practical applications, the polyamide is nylon 6 or nylon 66.

[0025] In practical applications, the modified filler is a highly polar organic filler containing hydroxyl and carboxyl groups. Specifically, the carboxylic acid modified filler has multiple carboxyl and hydroxyl groups on its molecular chain and a molecular weight between 84 - 260.

[0026] In practical applications, the low water absorption nylon material further includes any one or a combination of a toughening agent, an antioxidant, and / or a lubricant. Specifically, the toughening agent is 0.1 - 1 part, the antioxidant is 0.01 - 5 parts, and the lubricant is 0.01 - 5 parts.

[0027] In practical applications, the toughening agent is one or a combination of polyvinyl formal, polyvinyl butyral, mercaptan - terminated nitrile rubber, polyurethane rubber, and maleic anhydride - grafted ethylene - octene copolymer. The antioxidant is one or a combination of octadecyl 3-(3,5 - di - tert - butyl - 4 - hydroxyphenyl) propionate, pentaerythritol tetrakis [3-(3,5 - di - tert - butyl - 4 - hydroxyphenyl) propionate], N,N'-bis [3-(3,5 - di - tert - butyl - 4 - hydroxyphenyl) propionyl] hexanediamine, bis(2,4 - di - tert - butylphenyl) pentaerythritol, zinc pentaerythritol, 2,6 - di - tert - butyl - 4 - methylphenol, and tris(2,4 - di - tert - butylphenyl) phosphite. The lubricant is one or a combination of OP wax, rosin ester wax, ethylene bisstearamide, calcium stearate, zinc stearate, and aluminum stearate.

[0028] In practical applications, the preparation method of the above - mentioned low water absorption nylon material includes the following steps:

[0029] Melt - blend and extrude each component.

[0030] In practical applications, the extrusion is carried out by melt blending extrusion using a twin-screw extruder. The temperatures of the first to fourteenth zones of the screws of the twin-screw extruder are set as follows: the temperature of the first zone is 30 - 230 °C, the temperature of the second zone is 50 - 250 °C, the temperature of the third zone is 80 - 260 °C, the temperature of the fourth zone is 200 - 260 °C, the temperature of the fifth zone is 200 - 260 °C, the temperature of the sixth zone is 200 - 260 °C, the temperature of the seventh zone is 200 - 260 °C, the temperature of the eighth zone is 200 - 260 °C, the temperature of the ninth zone is 200 - 260 °C, the temperature of the tenth zone is 200 - 260 °C, the temperature of the eleventh zone is 210 - 280 °C, the temperature of the twelfth zone is 210 - 280 °C, the temperature of the thirteenth zone is 210 - 280 °C, and the temperature of the fourteenth zone is 210 - 280 °C. The temperatures of the twenty-first and seventy-first zones of the die head are set as follows: the temperature of the twenty-first zone is 210 - 280 °C, and the temperature of the seventy-first zone is 210 - 280 °C.

[0031] In practical applications, the above low water absorption nylon material is applied in automobiles, chemical industry, machinery, and precision instruments.

[0032] The advantages of the present invention will be further elaborated through more specific embodiments below, but the protection scope of the present invention is not limited only to the following embodiments.

[0033] Table 1 gives the formulations of Examples 1 - 6 and Comparative Examples 1 - 5 of the low water absorption nylon material of the present invention. Among them, the modified filler used in Comparative Example 5 is maleic anhydride grafted polyolefin elastomer, and the carboxylic acid-based organic filler of the present application is used in Examples 1 - 5. Each nylon material is obtained by melt blending extrusion according to the components and their contents given in Table 1.

[0034] Table 1

[0035]

[0036] Performance test:

[0037] Tensile property: The elongation at break (%) and tensile strength (MPa) of the material are tested according to the method in ISO 527-2;

[0038] Flexural property: The flexural modulus (MPa) and flexural strength (MPa) of the material are tested according to the method in ISO 178;

[0039] Impact strength: Tested according to ISO 179-1e / A;

[0040] Equilibrium water absorption: The water absorption of the material is tested according to ISO 62 at 23 °C and a relative humidity of 50% RH.

[0041] The nylon materials provided in Examples 1 - 6 and Comparative Examples 1 - 5 are tested according to the above test methods, and the test results are shown in Table 2:

[0042] Table 2

[0043]

[0044]

[0045] From the results of Comparative Examples 1-4 and Examples 1-6 in Table 2, it can be seen that after adding the carboxylic acid-modified filler to the method of the present invention, the equilibrium water absorption rate of the nylon material can be effectively reduced, and the mechanical properties of the nylon material are improved, making it have excellent strength and stiffness.

[0046] It can also be seen from the results of Examples 1-6 that the comprehensive performance of Example 5 is the strongest.

[0047] From Comparative Example 5 and Example 3, it can be seen that in terms of the equilibrium water absorption rate of the nylon material, Example 3 using the carboxylic acid-modified filler described in the present application shows significant advantages. Specifically, the equilibrium water absorption rate of Example 3 is only 1.4%, far lower than the 2.9% equilibrium water absorption rate of the maleic anhydride-grafted polyolefin elastomer used in Comparative Example 5. It can be seen that the carboxylic acid-modified filler of the present application has a significant effect on reducing the equilibrium water absorption rate of the nylon material.

[0048] Advantages of the implementation of the present invention:

[0049] 1. The carboxylic acid-modified filler uses a highly polar organic filler containing hydroxyl and carboxyl groups. When the carboxylic acid-modified filler is melt-blended and extruded with glass fiber and nylon, the hydroxyl groups on the modified filler combine with the coupling agent, enabling the glass fiber to be evenly dispersed in the nylon substrate; the remaining hydroxyl and carboxyl groups on the modified filler form hydrogen bonds with the amide bonds of the nylon, which can effectively inhibit the water absorption of the nylon material. Therefore, the addition of the modified filler can not only make the combination of the glass fiber and the nylon matrix closer, but also effectively reduce the water absorption rate of the material without the need to additionally add anti-humidity agents.

[0050] 2. Due to the addition of the carboxylic acid-modified filler, the combination of the glass fiber and the nylon matrix becomes closer, so the mechanical properties of the material are further improved, having excellent strength and stiffness, and the water absorption rate is lower than that of ordinary nylon materials and other types of glass fiber-reinforced nylon materials.

[0051] 3. The preparation of the low water absorption nylon material adopts a twin-screw extrusion process, which is simple in method and reduces production costs.

[0052] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims described above.

Claims

1. A nylon material with low water absorption, characterized in that: The invention comprises 45-85 parts of polyamide, 10-55 parts of glass fiber, 0.1-5 parts of carboxylic acid modified filler and 0.5-5 parts of coupling agent.

2. A nylon material with low water absorption according to claim 1, characterized in that: The polyamide is nylon 6 or nylon 66.

3. The low water absorption nylon material according to claim 1, characterized in that: The carboxylic acid modified filler is a highly polar organic filler containing hydroxyl groups and carboxyl groups.

4. A nylon material with low water absorption according to claim 3, characterized in that: The carboxylic acid modified filler has multiple carboxyl groups and hydroxyl groups on its molecular chain, and its molecular weight is between 84 and 260.

5. The low water absorption nylon material according to claim 1, characterized in that: It also includes any one or a combination of a toughening agent, an antioxidant and / or a lubricant.

6. The low water absorption nylon material according to claim 5, characterized in that: The toughening agent is 0.1-1 part.

7. The low water absorption nylon material according to claim 5, characterized in that: The antioxidant is 0.01-5 parts.

8. The low water absorption nylon material according to claim 5, characterized in that: The lubricant is 0.01-5 parts.

9. A method for preparing a nylon material with low water absorption according to any one of claims 1 to 8, comprising the following steps: The components are melt blended and extruded.

10. Application of the low water absorption nylon material according to any one of claims 1 to 8 in automobiles, chemicals, machinery, and precision instruments.

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