High-strength low-warpage POK composite material, preparation method thereof and plastic part

Abstract

The invention discloses a high-strength low-warpage POK composite material, a preparation method thereof and a plastic part, and the high-strength low-warpage POK composite material provided by the invention is prepared from the following raw material components in parts by weight: 40 to 60 parts of POK resin, 10 to 15 parts of mineral filler, 30 to 40 parts of glass fiber, 0.1 to 0.3 part of antioxidant and 0.2 to 0.5 part of lubricant. The glass fibers are at least one of flat glass fibers and ground glass fibers. In a POK material system, specific types of glass fibers and mineral filler are added, and the combination ratio of the glass fibers to the mineral filler is adjusted, so that the comprehensive performance and warping resistance of the POK are greatly improved on the basis of not damaging the original wear resistance, chemical resistance and hydrolysis resistance of the POK.

Description

Technical Field

[0001] The present invention relates to the technical field of POK resin materials, and in particular, to a high-strength and low-warpage POK composite material, a preparation method thereof, and a plastic part. Background Art

[0002] Polyketone (POK) is a new type of green polymer material synthesized from carbon monoxide and olefins (ethylene, propylene). The main chain of the molecule is an engineering plastic formed by carbon and hydrogen through high crystallization to form a dense crystal structure, with high strength, excellent chemical resistance, impact resistance, friction performance, and high barrier properties. However, the strength of pure POK is relatively low. Although glass fiber-reinforced PK improves the strength, during the injection molding process of the material, it will be oriented along the fluid flow direction, inducing PK to crystallize around the glass fiber, restricting the resin shrinkage in the flow direction, making the shrinkage rate in the flow direction less than the longitudinal shrinkage rate, and causing serious warping of the product, which limits the scope of use of the material. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a high-strength and low-warpage POK composite material, a preparation method thereof, and a plastic part.

[0004] The present invention solves its technical problems by adopting the following technical solutions.

[0005] The present invention provides a high-strength and low-warpage POK composite material. By weight, the preparation raw materials of the high-strength and low-warpage POK composite material include the following components: 40 - 60 parts of POK resin, 10 - 15 parts of mineral filler, 30 - 40 parts of glass fiber, 0.1 - 0.3 parts of antioxidant, and 0.2 - 0.5 parts of lubricant;

[0006] The glass fiber is at least one of flat glass fiber and ground glass fiber.

[0007] The present invention also provides a preparation method of the above-mentioned high-strength and low-warpage POK composite material, including the following steps: extruding, cooling, pelletizing, and drying and injection molding the preparation raw materials mixed according to the ratio.

[0008] The present invention also provides a plastic part, which is made of the above-mentioned high-strength and low-warpage POK composite material.

[0009] The present invention has the following beneficial effects:

[0010] The present invention provides a high-strength low-warpage POK composite material and a preparation method thereof and a plastic part. By scientifically mixing POK resin, mineral filler, glass fiber, antioxidant and lubricant, and controlling the glass fiber and filler mineral in the POK system to be compounded in an appropriate proportion, a low-warpage POK composite material with excellent performance is obtained. Compared with the original POK composite material, the strength and stability of the composite material can be effectively improved, and the warpage deformation problem of the composite material can be reduced. DETAILED DESCRIPTION

[0011] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0012] A high-strength, low-warpage POK composite material, a preparation method thereof, and a plastic part provided by an embodiment of the present invention are described in detail below.

[0013] In a first aspect, an embodiment of the present invention provides a high-strength and low-warpage POK composite material. The raw materials for preparing the high-strength and low-warpage POK composite material include the following components by weight: 40-60 parts of POK resin, 10-15 parts of mineral filler, 30-40 parts of glass fiber, 0.1-0.3 parts of antioxidant, and 0.2-0.5 parts of lubricant;

[0014] The glass fiber is at least one of flat glass fiber and milled glass fiber.

[0015] Warping of thermoplastic products is the most common problem in injection molding. Currently, the commonly used improvement methods mainly include optimizing mold structure design and adding fillers. Improvement from the mold structure is mainly achieved by optimizing the cooling water channel design to balance cooling, rationalizing the gate design to ensure uniform pressure distribution and the initial structure of the product to preset anti-deformation compensation design, but mold design optimization may require higher mold manufacturing costs and longer cycles, and may also have more restrictions on product design. Improvement from adding anti-warping fillers is mainly achieved by selectively adding anti-warping fillers, but compatibility issues between resins and fillers may lead to performance degradation or even separation, which in turn affects other properties.

[0016] Through a large amount of research and practice, the inventor has proposed a high-strength and low-warpage POK composite material. By weight, the raw materials for preparing the high-strength and low-warpage POK composite material include the following components: 40-60 parts of POK resin, 10-15 parts of mineral filler, 30-40 parts of glass fiber, 0.1-0.3 parts of antioxidant, and 0.2-0.5 parts of lubricant, wherein: the glass fiber is at least one of flat glass fiber and ground glass fiber. The addition of the above glass fiber can reduce the warpage deformation caused by the uneven shrinkage in each direction due to molecular orientation or glass fiber orientation. The addition of the mineral filler can limit the mutual movement between the polymer chains in the POK resin matrix, reduce the crystallization ability of the substrate, reduce the crystallinity of the material, and thus reduce the shrinkage rate of the material. Through the combination of glass fiber and mineral filler above, on the basis of not damaging the original performance of POK, the strength and warpage resistance of POK are greatly improved.

[0017] In some optional embodiments, the POK resin is compounded from a low-viscosity resin and a medium-viscosity resin in a ratio of (1-1.5):1;

[0018] Preferably, the POK resin is compounded from a low-viscosity resin and a medium-viscosity resin in a ratio of (1.2-1.5):1;

[0019] Preferably, the medium-viscosity resin is a POK resin with a weight-average molecular weight of 170,000-190,000; the low-viscosity resin is a POK resin with a weight-average molecular weight of 120,000-140,000.

[0020] In some optional embodiments, the mineral filler includes nano calcium carbonate, talcum powder, wollastonite, mica, glass microspheres, calcium sulfate whiskers, heavy calcium carbonate, kaolin, barium sulfate, and is preferably nano calcium carbonate.

[0021] When a crystalline material cools after injection, the molecules begin to orient and crystallize. Especially for materials with high crystallinity and fast crystallization rate, internal stress will remain after crystallization, resulting in shrinkage and warpage after cooling and shaping. Adding inorganic fillers can limit the mutual movement between polymer chains, thereby reducing the crystallinity and shrinkage rate of the material. Due to the low thermal expansion coefficient of nano calcium carbonate, the stress concentration and warpage caused by thermal expansion and contraction are reduced. Its spherical particles with small particle size and large specific surface area are evenly dispersed in the plastic matrix, forming a three-dimensional network structure, further inhibiting the abnormal movement of molecular chains and enhancing the overall dimensional stability. Therefore, nano calcium carbonate is preferred.

[0022] In some optional embodiments, the flat ratio of the flat glass fiber is 1:(3-4), preferably 1:4; the length of the ground glass fiber is 0.1-0.3 mm, and the diameter is 5 μm-15 μm.

[0023] In some alternative embodiments, the glass fiber is selected from ground glass fiber and flat glass fiber with a mass ratio of 1:(2 - 3).

[0024] It should be noted that ordinary glass fiber refers to glass fiber with a cylindrical cross-section; flat glass fiber refers to glass fiber with an elliptical cross-section; ground glass fiber refers to glass fiber with a cylindrical cross-section. Through multiple experiments, the inventor found that when the above three types of glass fibers are added to the POK resin matrix, their warpage resistance capabilities are as follows: ground glass fiber > flat glass fiber > ordinary glass fiber. Therefore, in the embodiments of the present invention, ground glass fiber or flat glass fiber is preferably used as the reinforcing phase. Further, the difference in warpage resistance performance between flat glass fiber with a flat ratio of 1:4 and flat glass fiber with a flat ratio of 1:3 is not significant, but the warpage value is lower. Therefore, flat glass fiber with a flat ratio of 1:4 is preferably used as the reinforcing phase. In addition, after the flat glass fiber and the ground glass fiber are compounded, the warpage value is further reduced and the comprehensive performance is better. Therefore, it is more preferable to compound and use the flat glass fiber and the ground glass fiber.

[0025] In some alternative embodiments, the antioxidant includes at least one of antioxidant 1098, antioxidant 1076, antioxidant 1010, antioxidant DEOXS80, antioxidant 9228, antioxidant 608, antioxidant 168, and antioxidant MD697.

[0026] In some alternative embodiments, the lubricant includes at least one of silicone powder, calcium stearate, zinc stearate, pentaerythritol stearate, ethylene bis-stearamide, OP wax, TAF, talc powder, and PE wax.

[0027] In a second aspect, an embodiment of the present invention provides a method for preparing the above-mentioned high-strength and low-warpage POK composite material, including the following steps: extruding, cooling, pelletizing, and drying and injecting the prepared raw materials mixed according to the ratio.

[0028] In some alternative embodiments, the extrusion is carried out using a twin-screw extruder. The twin-screw extruder has 11 temperature zones, and the temperatures of the 11 temperature zones are 100°C - 110°C, 225°C - 230°C, 225°C - 230°C, 210°C - 220°C, 210°C - 220°C, 210°C - 220°C, 210°C - 220°C, 210°C - 220°C, 210°C - 220°C, 210°C - 220°C, and 220°C - 230°C in sequence. The rotation speed of the twin-screw extruder is 200 rpm - 300 rpm;

[0029] Preferably, the temperatures of the 11 temperature zones of the twin-screw extruder are 100°C, 230°C, 230°C, 220°C, 220°C, 220°C, 220°C, 215°C, 215°C, 210°C, and 220°C in sequence, and the rotation speed of the twin-screw extruder is 240 rpm.

[0030] In a third aspect, an embodiment of the present invention provides a plastic part, which is made of the above-mentioned high-strength and low-warpage POK composite material.

[0031] The present invention will be further described below with reference to embodiments.

[0032] The manufacturers and grades of the high-viscosity POK resin, high-viscosity POK resin, ordinary glass fiber, flat glass fiber (flat ratio 1:3), flat glass fiber (flat ratio 1:4), and ground glass fiber used in the following examples and comparative examples are as follows:

[0033] The medium-viscosity POK resin, with the grade of M330F and a number-average molecular weight in the range of 170,000 - 190,000, is purchased from SK Chemicals;

[0034] The low-viscosity POK resin, with the grade of M930F and a number-average molecular weight in the range of 120,000 - 140,000, is purchased from SK Chemicals;

[0035] The ordinary glass fiber, with the grade of ECS301HP-3-H, is purchased from Chongqing International Composite Co., Ltd.;

[0036] The flat glass fiber (flat ratio 1:3), with the grade of ECS3F-03-568H, is purchased from China National Bluestar (Group) Co., Ltd.;

[0037] The flat glass fiber (flat ratio 1:4), with the grade of ECS4F-03-568H, is purchased from China National Bluestar (Group) Co., Ltd.;

[0038] The ground glass fiber, with the grade of EMG11-200, is purchased from Chongqing International Composite Co., Ltd.;

[0039] The nano calcium carbonate, with the grade of XM-NC103, is purchased from Guangdong Xinmei Nano Technology Co., Ltd.;

[0040] The heavy calcium carbonate, with the grade of C-9185, is purchased from Suzhou Yousu Minerals New Materials;

[0041] The talcum powder, with the grade of 8510, is purchased from Suzhou Yousu Minerals New Materials;

[0042] The wollastonite, with the grade of FG-10, is purchased from Suzhou Yousu Minerals New Materials;

[0043] The mica powder, with the grade of 200FG, is purchased from Suzhou Yousu Minerals New Materials;

[0044] The barium sulfate, with the grade of B-4800, is purchased from Suzhou Yousu Minerals New Materials;

[0045] The kaolin, with the grade of G9422, is purchased from Suzhou Yousu Minerals New Materials;

[0046] Calcium sulfate whiskers, grade DL-40H, were purchased from Chizhou Guangwei New Materials.

[0047] Examples 1-9

[0048]

[0049] Weigh the raw materials in Examples 1-9 except for glass fiber and mineral filler (filled ore powder), add them to a high-speed mixer and mix evenly, then add them to the main feeding port. Glass fiber and filled ore powder are added from the side feeding port. After melting and extruding through an extruder, granulation is carried out to obtain the product.

[0050] Inject the products prepared in Examples 1-9 into flat plates with dimensions of 100*150 mm and a thickness of 2 mm, place them in a constant temperature and humidity laboratory for 48 h, and then test the maximum height after warping to evaluate their warping performance. The test methods for basic physical properties refer to ISO international standards. The warping degree and basic physical property results are shown in the following table:

[0051]

[0052] By comparing the data of Examples 1-9, it can be seen that after adding mineral filler nano-calcium carbonate to the high-strength and low-warp POK composite material, the warping value of the system can be further reduced. In addition, from the perspective of glass fiber types, adding ordinary glass fiber results in the largest warping degree. Flat glass fiber has much less warping than ordinary glass fiber, and its physical properties are similar to those of ordinary glass fiber. Milled glass fiber has the best flatness, but its physical properties are too poor. In addition, although the flatness of flat glass fiber is slightly worse than that of milled glass fiber, its strength and rigidity are better. The flat glass fiber with a flatness ratio of 1:4 has little difference in performance from the flat glass fiber with a flatness ratio of 1:3, but its warping value is lower. And after being compounded with milled glass fiber, its warping value is further reduced. Therefore, flat glass fiber and milled glass fiber are selected for compounding and used as subsequent comparison samples.

[0053] Examples 10-15

[0054]

[0055]

[0056] Weigh the raw materials in Examples 10-15 except for glass fiber and filled ore powder, add them to a high-speed mixer and mix evenly, then add them to the main feeding port. Glass fiber and ore powder are added from the side feeding port. After melting and extruding through an extruder, granulation is carried out to obtain the product.

[0057] Inject the products prepared in Examples 10-15 into flat plates with dimensions of 100*150 mm and a thickness of 2 mm, place them in a constant temperature and humidity laboratory for 48 h, and then test the maximum height after warping to evaluate their warping performance. The test methods for basic physical properties refer to ISO international standards. The warping degree and basic physical property results are shown in the following table:

[0058] Test Items Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Tensile Strength MPa 134 138 120 150 132 123 Flexural Modulus MPa 8334 8664 6853 8805 8124 7623 <![CDATA[Notched impact strength KJ / m 2 > 14.2 14.8 14.4 15.6 13.5 12.3 Warpage Height mm 0.94 1.15 0.75 1.12 1.12 1.04

[0059] By comparing the data of Examples 10 - 15, an increase in the filling amount of nano - calcium carbonate can slightly improve its mechanical properties and also has a certain improvement in reducing warpage. However, exceeding a certain amount will instead reduce its performance. When using a compound of flat glass fiber and milled glass fiber, if the content of milled glass fiber is high, although the warpage value is low, the performance is low. If the content of milled glass fiber is low, the performance is maintained, but the warpage value becomes larger. In Example 10, an appropriate proportion compound of flat glass fiber with a flatness ratio of 1:4 and milled glass fiber can obtain a composite material with both mechanical properties and a low warpage value.

[0060] Examples 16 - 23

[0061]

[0062]

[0063] Weigh the raw materials in Examples 16 - 23 except for glass fiber and filled mineral powder, add them to a high - speed mixer and mix evenly, then add them to the main feeding port. Glass fiber and mineral powder are added from the side feeding port. After melting and extruding through an extruder, granulation is carried out to obtain the product.

[0064] Inject the products prepared in Examples 16 - 23 into flat plates with a size of 100 * 150 mm and a thickness of 2 mm. After placing them in a constant - temperature and constant - humidity laboratory for 48 h, test the maximum height after warpage to evaluate their warpage performance. The test methods for basic physical properties refer to ISO international standards. The warpage degree and basic physical property results are shown in the following table:

[0065]

[0066] By comparing the data of Examples 10, 16 - 23, it can be seen that compared with not adding mineral fillers, adding mineral fillers can effectively reduce the warpage value of POK composite materials. However, among them, the warpage value of adding nano - calcium carbonate in the system is the lowest. Due to its low coefficient of thermal expansion, it can reduce stress concentration and warpage caused by thermal expansion and contraction. Its spherical particles with small particle size and large specific surface area are evenly dispersed in the plastic matrix, forming a three - dimensional network structure, further inhibiting the abnormal movement of molecular chains and enhancing the overall dimensional stability.

[0067] Comparative Examples 1 - 5

[0068] Formulation (by weight) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 M930F 40 40 40 30 30 M330F 29.2 29.2 29.2 24.2 24.2 Nano Calcium Carbonate 15 15 Common Glass Fiber 22.5 22.5 Flat Glass Fiber (Aspect Ratio 1:3) 22.5 22.5 Flat Glass Fiber (Aspect Ratio 1:4) 22.5 Milled Glass Fiber 7.5 7.5 7.5 7.5 7.5 Antioxidant 168 0.3 0.3 0.3 0.3 0.3 Lubricant Silicone Powder 0.5 0.5 0.5 0.5 0.5

[0069] Weigh the raw materials in Comparative Examples 1 - 5 except for glass fiber and filled mineral powder, add them to a high - speed mixer and mix evenly, then add them to the main feeding port. Glass fiber and mineral powder are added from the side feeding port. After melting and extruding through an extruder, granulation is carried out to obtain the product.

[0070] The products prepared in Examples 1-5 were injection molded into flat plates with dimensions of 100*150 mm and a thickness of 2 mm. After being placed in a thermostatic and humid laboratory for 48 h, the maximum height after warping was measured to evaluate their warping performance. The test methods for basic physical properties refer to ISO international standards. The warping degree and basic physical property results are shown in the following table:

[0071] Test Items Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Tensile Strength MPa 130 131 133 131 133 Flexural Modulus MPa 8384 8464 8382 8205 8324 <![CDATA[Notched impact strength KJ / m 2 > 14.8 14.6 14.5 13.8 13.5 Warpage Height mm 4.74 3.65 3.15 1.67 1.12

[0072] By comparing the data of Example 10 with those of Comparative Examples 1-5, it can be seen that when flat glass fiber with an aspect ratio of 1:4, ground glass fiber, and nano-calcium carbonate are used in combination, while ensuring mechanical properties, the warping value can be better reduced.

[0073] In summary, due to the flattening treatment of flat glass fiber, the anisotropy in the longitudinal and transverse directions of the material is greatly reduced, and the warping degree of the product is significantly reduced. At the same time, it still maintains a very high mechanical strength. The anisotropy of ground glass fiber is smaller than that of flat glass fiber, and the shrinkage difference in the longitudinal and transverse directions is smaller. Due to its fine structure, nano-fillers can fill into the voids of the composite material to form a dense structure, further reducing the warping value. Therefore, when flat glass fiber and ground glass fiber are used in combination and nano-fillers are added at the same time, the anisotropy of the material can be further improved, and the warping degree can be further reduced. A product with a small warping degree and balanced physical properties can be obtained, that is, it can improve the strength to meet the requirements of structural parts and has a low warping degree, thus meeting the actual use requirements of the product and broadening the application of POK materials in various fields.

[0074] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-strength and low-warpage POK composite material, characterized in that: The raw materials for preparing the high-strength and low-warpage POK composite material include the following components by weight: 40-60 parts of POK resin, 10-15 parts of mineral filler, 30-40 parts of glass fiber, 0.1-0.3 parts of antioxidant, and 0.2-0.5 parts of lubricant; The glass fiber is at least one of flat glass fiber and milled glass fiber.

2. The high-strength and low-warpage POK composite material according to claim 1, characterized in that: The POK resin is prepared by compounding a low-viscosity resin and a medium-viscosity resin in a ratio of (1-1.5):1; Preferably, the POK resin is compounded by low viscosity resin and medium viscosity resin in a ratio of (1.2-1.5):1; Preferably, the low-viscosity resin is a POK resin with a weight average molecular weight of 120,000-140,000, and the medium-viscosity resin is a POK resin with a weight average molecular weight of 170,000-190,000.

3. The high-strength and low-warpage POK composite material according to claim 1, characterized in that: The flatness ratio of the flat glass fiber is 1:(3-4), preferably 1:4; the length of the ground glass fiber is 0.1-0.3 mm, and the diameter is 5 μm-15 μm.

4. The high-strength and low-warpage POK composite material according to claim 1, characterized in that: The glass fiber is selected from a mixed glass fiber of milled glass fiber and flat glass fiber in a mass ratio of 1:(2-3).

5. The high-strength and low-warpage POK composite material according to claim 1, characterized in that: The mineral filler includes nano calcium carbonate, talc, wollastonite, mica, glass microspheres, calcium sulfate whiskers, heavy calcium carbonate, kaolin, barium sulfate, preferably nano calcium carbonate.

6. The high-strength and low-warpage POK composite material according to claim 1, characterized in that: The antioxidant includes at least one of antioxidant 1098, antioxidant 1076, antioxidant 1010, antioxidant DEOXS80, antioxidant 9228, antioxidant 608, antioxidant 168, and antioxidant MD697.

7. The high-strength and low-warpage POK composite material according to claim 1, characterized in that: The lubricant includes at least one of silicone powder, calcium stearate, zinc stearate, pentaerythritol stearate, ethylene bis stearamide, OP wax, TAF, talc, and PE wax.

8. A method for preparing a high-strength, low-warpage POK composite material according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: extruding, cooling, granulating, drying and injection molding the raw materials mixed according to a certain ratio.

9. The preparation method according to claim 8, characterized in that: The extrusion is carried out by a twin-screw extruder, the twin-screw extruder has 11 temperature zones, the temperatures of the 11 temperature zones are 100°C-110°C, 225°C-230°C, 225°C-230°C, 210°C-220°C, 210°C-220°C, 210°C-220°C, 210°C-220°C, 210°C-220°C, 210°C-220°C, 210°C-220°C, 210°C-220°C and 220°C-230°C, and the speed of the twin-screw extruder is 200rpm-300rpm; Preferably, the temperatures of the 11 temperature zones of the twin-screw extruder are 100°C, 230°C, 230°C, 220°C, 220°C, 220°C, 215°C, 215°C, 210°C and 220°C respectively, and the rotation speed of the twin-screw extruder is 240rpm.

10. A plastic part, characterized in that: Made of the high-strength and low-warpage POK composite material described in any one of claims 1 to 7.

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