High glass fiber reinforced PA6 / PA6I6T alloy material and preparation method thereof

Abstract

The invention discloses a high glass fiber reinforced PA6 / PA6I6T alloy material and a preparation method of the high glass fiber reinforced PA6 / PA6I6T alloy material. The high glass fiber reinforced PA6 / PA6I6T alloy material is prepared from the following components in parts by weight: 35 to 45 parts of PA6 resin, 3 to 10 parts of PA6I6T resin, 50 to 60 parts of flat glass fiber, 3 to 8 parts of a grafting toughening agent, 0.2 to 0.5 part of a coupling agent and 0.1 to 0.5 part of an antioxidant, wherein the length-width ratio of the flat glass fibers ranges from 10: 1 to 20: 1. The PA6 resin is used as a base material, a certain proportion of PA6I6T resin is compounded, MBS-g-MAH is added for toughening, flat S-grade glass fibers are compounded for reinforcement, and the finally obtained alloy material has great advantages in the aspects of physical performance, warping resistance and weather resistance.

Description

Technical Field

[0001] The present invention relates to a high-glass-fiber-reinforced PA6 material, and in particular to a high-glass-fiber-reinforced PA6 / PA6I6T alloy material and a preparation method thereof. Background Art

[0002] PA6 is the earliest developed type of engineering plastic and currently one of the most produced polyamide plastics, boasting excellent overall performance. Glass fiber reinforcement significantly improves PA6's rigidity, but at the expense of impact toughness. Furthermore, as the glass fiber content of the composite increases, high-glass-fiber PA6 composites are more susceptible to molding defects such as "floating fibers" on the surface of molded parts. With increasingly stringent material requirements in the automotive, electronics, and aviation industries, there is a growing demand for lightweight materials with high strength, toughness, and weather resistance.

[0003] Current research on high-glass-fiber-reinforced PA6 is generally limited to optimizing the surface treatment of the glass fiber, such as using silane coupling agents to increase the surface bonding between the glass fiber and the resin. Research on anti-floating fiber systems often involves adding lubricants, such as PETS and silicone masterbatches, to enhance the material's internal lubrication. Therefore, developing a composite material with high toughness, low water absorption, and good dimensional stability, while also offering improved overall physical properties, chemical resistance, and weather resistance compared to standard glass-fiber-reinforced PA6 materials, is crucial. Summary of the Invention

[0004] To overcome the above-mentioned shortcomings and deficiencies of the prior art, the present invention aims to provide a high-glass-fiber-reinforced PA6 / PA6I6T alloy material. Flat glass fibers require more energy when breaking, reducing extreme stress and significantly improving the impact strength of the material. At the same time, flat glass fibers are more easily oriented along the flow direction during injection molding, reducing anisotropy and significantly reducing the warping degree of the composite material.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned high glass fiber reinforced PA6 / PA6I6T alloy material.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] The present invention provides a high glass fiber reinforced PA6 / PA6I6T alloy material, which comprises, by weight:

[0008] 35-45 parts of PA6 resin,

[0009] 3-10 parts of PA6I6T resin,

[0010] 50-60 parts of flat glass fiber,

[0011] 3-8 parts of graft toughening agent,

[0012] 0.2-0.5 parts of coupling agent,

[0013] 0.1-0.5 parts of antioxidant;

[0014] Wherein, the aspect ratio of the flat glass fiber is between 10:1 and 20:1.

[0015] Preferably, the flat glass fiber is a flat S-grade glass fiber with a length of 50-200 μm and a thickness of 5-10 μm; more preferably, the S-grade flat glass fiber has a length of 80 μm, a thickness of 7 μm, and an aspect ratio of 12:1.

[0016] Preferably, the viscosity of the PA6 resin is 2.0-3.2; more preferably, the viscosity of the PA6 resin is in the range of 2.0-2.8.

[0017] Preferably, the PA6I6T resin has a melt index range of 10-25 g / 10 min under the test conditions of 325° C. and 5 kg weight.

[0018] Preferably, the graft toughening agent is maleic anhydride grafted MBS.

[0019] Preferably, the coupling agent is bisaminosilane.

[0020] Preferably, the antioxidant is a combination of a hindered phenol antioxidant and a phosphite auxiliary antioxidant; more preferably, the mass ratio of the hindered phenol antioxidant to the high temperature resistant phosphite auxiliary antioxidant is 1:1-3.

[0021] The present invention also provides a method for preparing the high glass fiber reinforced PA6 / PA6I6T alloy material, comprising the following steps:

[0022] Add PA6 resin and PA6I6T resin into the blender, then add MBS-g-MAH, coupling agent and antioxidant, and stir evenly at room temperature;

[0023] The evenly stirred material is placed in a co-rotating twin-screw extruder, and is melt-plasticized, extruded, cooled, and pelletized to obtain a high-glass fiber reinforced PA6 / PA6I6T alloy material; the flat glass fiber is added as a side feed in the extrusion process.

[0024] Preferably, the co-rotating twin-screw extruder adopts a barrier-type screw; the aspect ratio of the barrier-type screw is between 40:1-48:1, the compression ratio is between 2.5:1-3.0:1, the barrier section length is between 4D-5D, and the barrier gap is between 0.3-0.5mm; more preferably, the co-rotating twin-screw extruder has a aspect ratio of 45:1, a compression ratio of 2.5:1, a barrier section length of 4D, and a barrier gap of 0.4mm.

[0025] Preferably, the temperature of the melt plasticization is set to 250℃-290℃ in the first section, 250℃-290℃ in the second section, 250℃-290℃ in the third section, 250℃-290℃ in the fourth section, 250℃-290℃ in the fifth section, 250℃-280℃ in the sixth section, 250℃-280℃ in the seventh section, 250℃-280℃ in the eighth section, 270℃-290℃ in the ninth section, and 270℃-290℃ in the tenth section. The melt temperature is 270℃-290℃ and the head temperature is 270℃-300℃.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] (1) The high glass fiber reinforced PA6 / PA6I6T alloy material of the present invention is reinforced with flat S-grade glass fiber, and the glass fiber content is controlled between 50-60%. The flat S-grade glass fiber requires more energy when breaking, reduces the extreme stress, and can greatly improve the impact strength of the material; at the same time, the flat glass fiber is easier to orient along the flow direction during injection molding, reduces anisotropy, and can greatly reduce the warping degree of the composite material.

[0028] (2) The high glass fiber reinforced PA6 / PA6I6T alloy material suitable for the present invention adopts an alloy system of PA6 and PA6I6T compound, which not only retains the processing convenience and cost advantage of PA6, but also greatly improves the temperature resistance, dimensional stability and mechanical strength of the material; at the same time, the crystallization rate of PA6I6T is slower than that of PA6, and it is easy to be coated on the surface of the material during injection molding to form a protective layer, making it difficult for moisture to enter the interior of the material, thereby improving dimensional stability and also improving the surface gloss of the injection molded part.

[0029] (3) The high glass fiber reinforced PA6 / PA6I6T alloy material of the present invention uses MBS-g-MAH as a toughening agent. After being grafted with maleic anhydride, the polarity is significantly improved. Maleic anhydride can react with the terminal amino groups in PA6 and PA6I6T to form chemical bonds, significantly improving the interfacial bonding strength. At the same time, its core-shell structure also gives it higher toughening efficiency and lower rigidity loss.

[0030] (4) The high glass fiber reinforced PA6 / PA6I6T alloy material of the present invention uses bisaminosilane as a coupling agent, which has a higher functional group density, higher reactivity and stronger interface bonding ability. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through practice of the present invention. It should be understood that the following description is only used to explain the present invention and is not intended to limit the present invention.

[0032] As used herein, the terms "comprises," "including," "having," "containing" or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a listed element is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0033] The conjunction "consisting of" excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim, rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0034] When amount, concentration or other value or parameter is represented with range, preferred range or the range that a series of upper preferred value and lower preferred value limit are expressed, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value and any range lower limit or preferred value, no matter whether this range is disclosed separately.For example, when disclosing scope "1 to 5", described scope should be interpreted as including scope "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5" etc.When numerical range is described in this article, unless otherwise stated, otherwise this scope is intended to include its end value and all integers and fractions within this range.

[0035] The singular includes plural references unless the context clearly dictates otherwise. "Optional" or "either" means that the subsequently described event or incident can or cannot occur, and that the description includes instances where the event occurs and instances where it does not.

[0036] The indefinite articles "a" and "an" before the elements or components of the present invention do not limit the quantity requirement (i.e. the number of times they appear). Therefore, "a" or "an" should be interpreted as including one or at least one, and elements or components in the singular also include plural forms, unless the quantity clearly refers to only the singular form.

[0037] In addition, the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" described below mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the technical features involved in the various embodiments of the present invention may be combined with each other as long as they do not conflict with each other.

[0038] Examples 1-5

[0039] A high glass fiber reinforced PA6 / PA6I6T alloy material, comprising the following components in parts by weight:

[0040]

[0041] The viscosity of the PA6 resin is 2.4. The PA6I6T resin is a high-performance semi-aromatic nylon, whose Chinese name is poly(hexamethylene terephthalamide / isophthalamide). Its melt index range is between 10-25 g / 10 min (325° C., 5 kg). The glass fiber is an S-grade flat glass fiber with a length of 80 μm, a thickness of 7 μm, and an aspect ratio of 12:1.

[0042] The graft toughening agent is MBS-g-MAH, the coupling agent is bisaminosilane, and the antioxidant is a combination of a high-performance hindered phenol antioxidant and a high-temperature resistant phosphite auxiliary antioxidant. Preferably, the mass ratio of the high-performance hindered phenol antioxidant to the high-temperature resistant phosphite auxiliary antioxidant is 1:1-3.

[0043] Examples 1-5 were prepared according to the following method, which is suitable for high glass fiber reinforced PA6 / PA6I6T alloy materials:

[0044] (1) Weigh PA6 resin, PA6I6T resin, MBS-g-MAH, wear-resistant agent, coupling agent, antioxidant and glass fiber according to the required weight parts and set aside;

[0045] (2) Add PA6 resin and PA6I6T resin into a blender, then add MBS-g-MAH, bisaminosilane, and antioxidant, and stir evenly at room temperature;

[0046] (3) placing the material uniformly stirred in step (2) in a co-rotating twin-screw extruder, and performing melt plasticization, extrusion, cooling, and pelletizing to obtain a high-glass fiber reinforced PA6 / PA6I6T alloy material. During this process, glass fiber is added in the form of side feed in the extrusion section process.

[0047] Furthermore, in some embodiments of the present invention, the co-rotating twin-screw extruder uses a barrier screw, preferably with an aspect ratio of 45:1, a compression ratio of 2.5:1, a barrier section length of 4D, and a barrier gap of 0.4 mm.

[0048] Further, in some embodiments of the present invention, the temperature of the melt plasticization is set to 250℃-290℃ in the first section, 250℃-290℃ in the second section, 250℃-290℃ in the third section, 250℃-290℃ in the fourth section, 250℃-290℃ in the fifth section, 250℃-280℃ in the sixth section, 250℃-280℃ in the seventh section, 250℃-280℃ in the eighth section, 270℃-290℃ in the ninth section, and 270℃-290℃ in the tenth section. The melt temperature is 270℃-290℃, and the head temperature is 270℃-300℃.

[0049] Comparative Examples 1-4

[0050] The glass fiber reinforced PA6 composite materials of Comparative Examples 1-4 are the same as those of Examples 1-5 except for the different properties or amounts of the components shown in Table 1.

[0051] Table 1 Raw materials and dosage of Examples 1-5 and Comparative Examples 1-4 (in kg)

[0052]

[0053] Performance Testing

[0054] 1. The PA6 / PA6I6T composite materials obtained in the examples and comparative examples were dried in an oven at 120°C and then injection molded into standard performance test specimens. The injection molding temperature was as follows:

[0055] Feeding section: 280℃; second section: 290℃; third section: 300℃; nozzle: 300℃.

[0056] Finally, the injection molded strips were placed in a desiccator for conditioning: the temperature was adjusted to 23±2° C. for 24 hours. The performance test results of the materials of each embodiment and comparative example are shown in Table 2 below.

[0057] Table 2 Performance test results of materials in various embodiments and comparative examples

[0058]

[0059]

[0060] The test results of Examples 1-5 and Comparative Example 1 demonstrate that the addition of PA6I6T to the alloy composite material of the present invention improves the material's physical properties, such as rigidity and impact toughness, while also increasing the heat distortion temperature and surface gloss of the finished product. This is because PA6I6T crystallizes more slowly than PA6. Therefore, during melt cooling, PA6 preferentially contracts internally, while PA6I6T readily coats the material surface, enhancing surface gloss.

[0061] The test results of Example 4 and Comparative Example 2 demonstrate that the use of flat S-grade glass fibers in the alloy composite material of the present invention significantly improves the material's warpage resistance and also significantly enhances its physical properties. This is because flat glass fibers are more easily oriented along the flow direction during injection molding, reducing anisotropy and significantly reducing warpage in the composite material.

[0062] The test results of Example 2 and Comparative Example 3 show that the glass fiber content in the alloy composite material of the present invention is controlled between 50% and 60%. Compared with a glass fiber content of about 30%, the physical properties are significantly improved, and the heat deformation temperature is also slightly increased.

[0063] It can be seen from the test results of Example 4 and Comparative Example 4 that the alloy composite material of the present invention uses bisaminosilane as a coupling agent. Compared with the monoaminosilane coupling agent, its higher reactivity and stronger interfacial bonding ability enable the composite material to have better physical properties.

[0064] It will be easily understood by those skilled in the art that the above description is merely an embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high glass fiber reinforced PA6 / PA6I6T alloy material, characterized in that: Calculated by weight, comprising: 35-45 parts of PA6 resin, 3-10 parts of PA6I6T resin, 50-60 parts of flat glass fiber, 3-8 parts of graft toughening agent, 0.2-0.5 parts of coupling agent, 0.1-0.5 parts of antioxidant; Wherein, the aspect ratio of the flat glass fiber is between 10:1 and 20:

1.

2. The high glass fiber reinforced PA6 / PA6I6T alloy material according to claim 1, characterized in that: The flat glass fiber is a flat S-grade glass fiber with a length of 50-200 μm and a thickness of 5-10 μm.

3. The high glass fiber reinforced PA6 / PA6I6T alloy material according to claim 1, characterized in that: The viscosity of the PA6 resin is 2.0-3.

2.

4. The high glass fiber reinforced PA6 / PA6I6T alloy material according to claim 1, characterized in that: The PA6I6T resin has a melt index range of 10-25 g / 10 min under the test conditions of 325° C. and 5 kg weight.

5. The high glass fiber reinforced PA6 / PA6I6T alloy material according to claim 1, characterized in that: The graft toughening agent is MBS grafted with maleic anhydride.

6. The high glass fiber reinforced PA6 / PA6I6T alloy material according to claim 1, characterized in that: The coupling agent is bisaminosilane.

7. The high glass fiber reinforced PA6 / PA6I6T alloy material according to claim 1, characterized in that: The antioxidant is a combination of a hindered phenol antioxidant and a phosphite auxiliary antioxidant.

8. The method for preparing the high glass fiber reinforced PA6 / PA6I6T alloy material according to any one of claims 1 to 7, characterized in that: The following steps are involved: Add PA6 resin and PA6I6T resin into the blender, then add MBS-g-MAH, coupling agent and antioxidant, and stir evenly at room temperature; The evenly stirred material is placed in a co-rotating twin-screw extruder, and is melt-plasticized, extruded, cooled, and pelletized to obtain a high-glass fiber reinforced PA6 / PA6I6T alloy material; the flat glass fiber is added as a side feed in the extrusion process.

9. The preparation method according to claim 8, characterized in that The co-rotating twin-screw extruder adopts a barrier-type screw; the aspect ratio of the barrier-type screw is between 40:1-48:1, the compression ratio is between 2.5:1-3.0:1, the barrier section length is between 4D-5D, and the barrier gap is between 0.3-0.5mm.

10. The preparation method according to claim 8, characterized in that The temperature of the melt plasticization is set to 250℃-290℃ in the first section, 250℃-290℃ in the second section, 250℃-290℃ in the third section, 250℃-290℃ in the fourth section, 250℃-290℃ in the fifth section, 250℃-280℃ in the sixth section, 250℃-280℃ in the seventh section, 250℃-280℃ in the eighth section, 270℃-290℃ in the ninth section, and 270℃-290℃ in the tenth section. The melt temperature is 270℃-290℃ and the die head temperature is 270℃-300℃.

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