High-heat-resistance low-warpage nylon 6 reinforced material and preparation method thereof

Abstract

The invention provides a high-heat-resistance low-warpage nylon 6 reinforced material and a preparation method thereof, and the high-heat-resistance low-warpage nylon 6 reinforced material comprises the following components by mass: 45%-65% of nylon 6, 10%-20% of flat glass fiber, 20%-30% of mineral, 0.1%-0.5% of an antioxidant, 1%-5% of a compatilizer, and 0.3%-0.8% of a lubricant. According to the technical scheme, the flat glass fibers are adopted to replace traditional glass fibers with circular sections, more isotropic dispersions are provided, the orientation anisotropy of the material in all directions is small, and therefore warping of the thin-wall part is obviously improved, and the service life of the thin-wall part is prolonged. The technical problems that in the prior art, due to the fact that glass fibers are added, when the nylon 6 composite material is used for a thin-wall material, a product is prone to warping, and the local surface is distorted are solved.

Description

Technical Field

[0001] The invention relates to the technical field of nylon materials, and in particular to a nylon 6 reinforced material with high heat resistance and low warping and a preparation method thereof. Background Art

[0002] Nylon, also known as polyamide, is one of the most widely used and diverse engineering plastics. This material has excellent physical and chemical properties, such as good mechanical properties, heat resistance, wear resistance, chemical solvent resistance, self-lubrication and certain flame retardancy. At the same time, nylon material has good processing performance and has received increasing attention in the fields of electronic appliances, mechanical equipment, and household furniture.

[0003] However, ordinary nylon 6 also has some defects, such as easy water absorption, poor dimensional stability of products, relatively low strength, etc., so it is often necessary to modify it. Glass fiber reinforcement modification is one of the commonly used methods, which can give nylon materials excellent mechanical properties and surface state. After using circular cross-section glass fiber to reinforce and modify it, the rigidity of nylon 6 composite materials is greatly improved, and the water absorption is also improved. However, the addition of circular glass fiber leads to poor fluidity of the material, difficulty in product molding, and poor appearance; at the same time, due to the crystallinity of nylon 6 material and the orientation caused by the addition of glass fiber, the overall anisotropy of the material is more obvious, resulting in serious warping and deformation of the product. This phenomenon is called orientation effect warping, which refers to the situation where the shrinkage anisotropy of the material does not take into account the structural characteristics of the part itself and the external mold, resulting in different shrinkage rates in different areas of the part, and ultimately causing the part to warp and deform, causing the shape and size of the part product to fail to meet the design requirements, limiting its application, such as being unable to meet the use requirements of parts such as engine hoods. Summary of the invention

[0004] The purpose of the present invention is to provide a nylon 6 reinforced material with high heat resistance and low warping and a preparation method thereof, so as to solve the technical problem in the prior art that when nylon 6 composite materials are used to make thin-walled materials such as engine hoods, the products are prone to warping and local surface distortion due to the addition of glass fiber.

[0005] To achieve the above object, the present invention proposes the following technical solutions:

[0006] A high-heat-resistant and low-warping nylon 6 reinforced material comprises the following components by mass percentage: 45%-65% nylon 6, 10%-20% flat glass fiber, 20%-30% mineral, 0.1%-0.5% antioxidant, 1%-5% compatibilizer, and 0.3%-0.8% lubricant.

[0007] As a preferred technical solution of the present invention, the cross-sectional length of the flat glass fiber is 25 μm-32 μm, the cross-sectional width is 5 μm-10 μm, and the flatness is 3-5.

[0008] As a preferred technical solution of the present invention, the mineral includes talcum powder, glass microspheres or a mixture of the two or more thereof.

[0009] As a preferred technical solution of the present invention, the compatibilizer is one or a mixture of maleic anhydride grafted POE and grafted PP.

[0010] As a preferred technical solution of the present invention, the antioxidant is one or a mixture of several of an amine antioxidant, a phosphite, and a copper salt heat-resistant agent.

[0011] As a preferred technical solution of the present invention, the lubricant is one or a mixture of silicone lubricants, ethylene bisstearamide, and oleic acid amide.

[0012] The present invention also provides a method for preparing a high-heat-resistant and low-warping nylon 6 reinforced material, comprising the following steps:

[0013] Step 1: drying the nylon 6, and then feeding the nylon 6, mineral, antioxidant, compatibilizer and lubricant into a mixer according to the mass percentage ratio and mixing them evenly to obtain a premix;

[0014] Step 2: feeding the premix from the main feeding port of a twin-screw extruder, feeding the flat glass fiber from the side feeding port of the twin-screw extruder, melting, extruding, drawing, granulating, and drying to obtain the nylon 6 reinforced material.

[0015] As a preferred technical solution of the present invention, the drying temperature of nylon 6 in step 1 is 110° C.-120° C., and the drying time is 3-5 hours.

[0016] As a preferred technical solution of the present invention, the extrusion temperature of the twin-screw extruder is 220°C-260°C, and the screw speed is 200-400r / min.

[0017] As a preferred technical solution of the present invention, the drying temperature in step 2 is 110°C-120°C.

[0018] The technical solution of the present invention provides a nylon 6 reinforced material with high heat resistance and low warpage and a preparation method thereof, wherein flat glass fibers are used instead of conventional round cross-section glass fibers to improve the performance of nylon composite materials that are prone to warpage when used to make thin-walled structural parts. Mainly, the flat glass fibers tend to flow in a planar state like mica, rather than rolling and tumbling like conventional round glass monofilaments, which helps to provide more isotropic dispersions, so the orientation anisotropy in each direction is small, thereby significantly improving the warpage of thin-walled parts, and because the fibers are more closely arranged, a higher fiber volume fraction can be achieved without affecting other properties of the material.

[0019] Compared with fillers such as glass beads, flake glass fibers, and mineral talc that improve warpage, their structures are all non-fibrous, so they have certain limitations in strength. In addition to the dimensional stability, flat glass fibers also have better mechanical properties. The cross-sectional perimeter of flat glass fibers is much higher than that of equivalent circular cross-sectional glass fibers, so it is beneficial to improve the bonding strength between glass fibers and resins, thereby improving mechanical properties.

[0020] In addition, flat glass fiber is flat and thin. Under the same performance conditions, it is conducive to processing into thin-walled parts. At the same time, flat glass fiber has better fluidity. By reducing the shear force of nylon 6 material, it has better fluidity (increasing spiral flow), reducing friction and viscosity, and reducing the way fibers are entangled and broken, which is beneficial to the processing and molding of parts, so that the same parts can be molded on an injection press with a smaller gate.

[0021] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, may be considered to be part of the inventive subject matter of the present disclosure, provided such concepts are not mutually inconsistent. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs.

[0023] The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular form of "a", "an" or "the" and similar words do not indicate a quantity limitation, but indicate the existence of at least one. "Include" or "comprises" and similar words mean that the elements or objects appearing before "include" or "comprises" include the features, wholes, steps, operations, elements and / or components listed after "include" or "comprises", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections.

[0024] In order to solve the technical problem in the prior art that when nylon 6 composite materials are used to make thin-walled materials such as engine hoods, the addition of glass fibers causes the product to be easily warped and the local surface to be distorted, the embodiment of the present invention provides a nylon 6 reinforced material with high heat resistance and low warpage, which includes the following components in terms of mass percentage:

[0025] Nylon 64 5%-65%, flat glass fiber 10%-20%, mineral 20%-30%, antioxidant 0.1%-0.5%, compatibilizer 1%-5%, lubricant 0.3%-0.8%.

[0026] In the embodiment of the present invention, preferably, the cross-sectional length of the flat glass fiber is 25 μm-32 μm, the cross-sectional width is 5 μm-10 μm, and the flatness is 3-5.

[0027] The mineral includes one or a mixture of talc and glass microspheres. The compatibilizer is one or a mixture of maleic anhydride grafted POE and grafted PP. The antioxidant is one or a mixture of amine antioxidants, phosphites, and copper salt heat resistant agents. The lubricant is one or a mixture of silicone lubricants, ethylene bis stearamide (TAF), and oleic acid amide.

[0028] The embodiment of the present invention also provides a method for preparing a high-heat resistant and low-warping nylon 6 reinforced material, comprising the following steps:

[0029] Step 1: drying the nylon 6, wherein the drying temperature is 110° C.-120° C., and the drying time is 3-5 hours, and then feeding the nylon 6, mineral, antioxidant, compatibilizer and lubricant into a mixer according to the mass percentage ratio and mixing them evenly to obtain a premix.

[0030] Step 2: feeding the premix from the main feeding port of the twin-screw extruder, feeding the flat glass fiber from the side feeding port of the twin-screw extruder, melting, extruding, drawing, granulating, and drying, wherein the drying temperature is 110°C-120°C, to obtain the nylon 6 reinforced material. Preferably, in the embodiment of the present invention, the extrusion temperature of the twin-screw extruder is 220°C-260°C, and the screw speed is 200-400r / min.

[0031] The component formula of the present invention is described in detail below with several groups of specific embodiments.

[0032] Example 1

[0033] A high-heat-resistant and low-warping nylon 6 reinforced material comprises the following components by mass percentage: 65% nylon 6, 10% flat glass fiber, 20% mineral, 0.1% antioxidant, 1% compatibilizer and 0.3% lubricant.

[0034] The preparation method of the embodiment of the present invention comprises the following steps:

[0035] Step 1: drying the nylon 6 at a drying temperature of 110° C. for a drying time of 5 hours, and then feeding the nylon 6, mineral, antioxidant, compatibilizer and lubricant into a mixer according to a mass percentage ratio and mixing them evenly to obtain a premix;

[0036] Step 2: feeding the premix from the main feeding port of the twin-screw extruder, feeding the flat glass fiber from the side feeding port of the twin-screw extruder, melting, extruding, drawing, granulating, and drying at a drying temperature of 120° C. to obtain the nylon 6 reinforced material. The extrusion temperature of the twin-screw extruder during operation is 230° C.-260° C., and the screw speed is 400 r / min.

[0037] Example 2

[0038] A high-heat-resistant and low-warping nylon 6 reinforced material comprises the following components by mass percentage: 55% nylon 6, 15% flat glass fiber, 25% mineral, 0.3% antioxidant, 3% compatibilizer and 0.5% lubricant.

[0039] The preparation method of the embodiment of the present invention comprises the following steps:

[0040] Step 1: drying the nylon 6 at a drying temperature of 115° C. for a drying time of 4 hours, and then feeding the nylon 6, mineral, antioxidant, compatibilizer and lubricant into a mixer according to a mass percentage ratio and mixing them evenly to obtain a premix;

[0041] Step 2: feeding the premix from the main feeding port of the twin-screw extruder, feeding the flat glass fiber from the side feeding port of the twin-screw extruder, melting, extruding, drawing, granulating, and drying at a drying temperature of 110° C. to obtain the nylon 6 reinforced material. The extrusion temperature of the twin-screw extruder during operation is 230° C.-260° C., and the screw speed is 400 r / min.

[0042] Example 3

[0043] A high-heat-resistant and low-warping nylon 6 reinforced material comprises the following components by mass percentage: 45% nylon 6, 20% flat glass fiber, 30% mineral, 0.5% antioxidant, 5% compatibilizer and 0.8% lubricant.

[0044] The present invention also provides a method for preparing a high-heat-resistant and low-warping nylon 6 reinforced material, comprising the following steps:

[0045] Step 1: drying the nylon 6 at a drying temperature of 120° C. for a drying time of 3 hours, and then feeding the nylon 6, mineral, antioxidant, compatibilizer and lubricant into a mixer according to a mass percentage ratio and mixing them evenly to obtain a premix;

[0046] Step 2: feeding the premix from the main feeding port of the twin-screw extruder, feeding the flat glass fiber from the side feeding port of the twin-screw extruder, melting, extruding, drawing, granulating, and drying at a drying temperature of 115°C to obtain the nylon 6 reinforced material. The extrusion temperature of the twin-screw extruder during operation is 230°C-260°C, and the screw speed is 400r / min.

[0047] Comparative Example 1

[0048] A high-heat-resistant and low-warping nylon 6 reinforced material comprises the following components by mass percentage: 45% nylon 6, 15% glass fiber, 25% mineral, 0.3% antioxidant, 3% compatibilizer and 0.5% lubricant.

[0049] The present invention also provides a method for preparing a high-heat-resistant and low-warping nylon 6 reinforced material, comprising the following steps:

[0050] Step 1: drying the nylon 6, and then feeding the nylon 6, mineral, antioxidant, compatibilizer and lubricant into a mixer according to the mass percentage ratio and mixing them evenly to obtain a premix;

[0051] Step 2: feeding the premix from the main feeding port of a twin-screw extruder, feeding the flat glass fiber from the side feeding port of the twin-screw extruder, melting, extruding, drawing, granulating, and drying to obtain the nylon 6 reinforced material.

[0052] In material mechanics, warpage is usually used to describe the flexibility and rigidity of a material. A larger warpage means that an object is more likely to bend or deform, while a smaller warpage means that the object is relatively rigid. Through experimental testing, it was found that the warpage of the products obtained in Examples 1-3 of the embodiments of the present invention was significantly smaller than that of the comparative example, showing its excellent low warpage, which greatly improved the warpage performance of the material.

[0053] The performance comparison of other aspects of the product of the embodiment of the present invention and the comparative example is shown in Table 1 below. It can be seen from Table 1 that under the same sample conditions, the mechanical properties of the product of the embodiment of the present invention are not much different from those of the comparative example, indicating that the technical solution of the present invention can significantly improve the warping performance of the material while also making other mechanical properties of the material unchanged, that is, it hardly affects the mechanical properties of the material, so that it can still meet its application requirements.

[0054] Table 1 Product performance results of Examples 1-3 and Comparative Example 1

[0055]

[0056] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A high heat-resistant and low-warping nylon 6 reinforced material, characterized in that: Calculated by mass percentage, the invention comprises the following components: 45%-65% nylon 6, 10%-20% flat glass fiber, 20%-30% mineral, 0.1%-0.5% antioxidant, 1%-5% compatibilizer and 0.3%-0.8% lubricant.

2. The high-heat-resistant and low-warping nylon 6 reinforced material according to claim 1, characterized in that: The flat glass fiber has a cross-sectional length of 25 μm-32 μm, a cross-sectional width of 5 μm-10 μm, and a flatness of 3-5.

3. The high-heat-resistant and low-warping nylon 6 reinforced material according to claim 1, characterized in that: The minerals include talc powder, glass microspheres or a mixture of the two or more thereof.

4. The high-heat-resistant and low-warping nylon 6 reinforced material according to claim 1, characterized in that: The compatibilizer is one or a mixture of maleic anhydride grafted POE and grafted PP.

5. The high-heat-resistant and low-warping nylon 6 reinforced material according to claim 1, characterized in that: The antioxidant is one or a mixture of amine antioxidants, phosphites, and copper salt heat-resistant agents.

6. The high-heat-resistant and low-warping nylon 6 reinforced material according to claim 1, characterized in that: The lubricant is one or a mixture of silicone lubricant, ethylene bis stearamide, and oleic acid amide.

7. A method for preparing a high-heat-resistant and low-warping nylon 6 reinforced material as claimed in claims 1 to 6, characterized in that: The following steps are involved: Step 1: drying the nylon 6, and then feeding the nylon 6, mineral, antioxidant, compatibilizer and lubricant into a mixer according to the mass percentage ratio and mixing them evenly to obtain a premix; Step 2: feeding the premix from the main feeding port of a twin-screw extruder, feeding the flat glass fiber from the side feeding port of the twin-screw extruder, melting, extruding, drawing, granulating, and drying to obtain the nylon 6 reinforced material.

8. The method for preparing a high-heat-resistant and low-warping nylon 6 reinforced material according to claim 7, characterized in that: The drying temperature of nylon 6 in the step 1 is 110° C.-120° C., and the drying time is 3-5 hours.

9. The method for preparing a high-heat-resistant and low-warping nylon 6 reinforced material according to claim 7, characterized in that: The extrusion temperature of the twin-screw extruder is 220° C.-260° C., and the screw speed is 200-400 r / min.

10. The method for preparing a high-heat-resistant and low-warping nylon 6 reinforced material according to claim 7, characterized in that: The drying temperature in the step 2 is 110°C-120°C.

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