A pc composition, its preparation method and application

Abstract

The application discloses a PC composition and a preparation method and application thereof, and belongs to the technical field of high polymer materials. The product is obtained by optimizing the setting of inorganic fillers in components and compounding specific lubricants, and can realize high mechanical strength and low linear expansion coefficient under the condition of high filler filling amount, has small anisotropy, small difference between linear expansion coefficients in horizontal and vertical directions, good appearance and excellent comprehensive performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high molecular materials, in particular to a PC composition and a preparation method and application thereof. BACKGROUND

[0002] PC (polycarbonate) has excellent mechanical properties and flame retardant properties, and is theoretically an ideal thermoplastic engineering material, but in some application fields with high requirements for rigidity and dimensional stability, PC materials need to be compounded and modified by introducing inorganic materials (such as glass fiber, talc powder, etc.) to meet the requirements, but such practice will greatly increase the anisotropy of the product, especially after the introduction of glass fiber, although it can more effectively improve the mechanical properties of the product compared with other inorganic materials, but it will cause the product to have a larger difference in linear expansion degree in different directions during processing.

[0003] On the other hand, high inorganic filler filling amount will make the PC composite material have good dimensional stability and mechanical strength, but also cause appearance problems. SUMMARY

[0004] Based on the defects of the prior art, the purpose of the present application is to provide a PC composition, which can realize high mechanical strength and low linear expansion coefficient under high filler filling amount, small anisotropy, small difference in linear expansion coefficient between horizontal and vertical directions, good appearance and excellent comprehensive performance by optimizing the introduction of inorganic fillers in the components and compounding lubricants with a specific acid value.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A PC composition comprises the following components by weight:

[0007] PC resin 40-55 parts, flame retardant 5-15 parts, glass fiber 1-10 parts, inorganic filler particles 28-48 parts, lubricant 0.01-1 part;

[0008] The glass fiber and inorganic filler particles satisfy:

[0009] 0.4≤R / D≤1.8;

[0010] Wherein R is the retention aspect ratio of the glass fiber, and D is the retention average particle size of the inorganic filler particles, in units of μm;

[0011] The acid value of the lubricant is 15-32 mKOH / g.

[0012] Glass fiber composite high filling amount inorganic filler filled PC composite material is not uncommon in the market, the main reason is that glass fiber composite inorganic filler compared with other filling system for PC composite material mechanical properties (especially flexural modulus) and the improvement of dimensional stability is greater, but the fiber morphology of glass fiber will increase the anisotropy of PC composite material, and high inorganic filler filling may cause the problem of poor appearance, therefore, in the technical scheme of the application, the product introduces specific content of glass fiber and inorganic filler in PC resin matrix, and optimizes the size parameters of the two, so that the product can not only maintain the flexural modulus above 10000 MPa, high dimensional stability, low linear expansion coefficient, at the same time, the glass fiber is fully embedded in the inorganic filler particles to form uniform distribution effect, inhibit the anisotropy of glass fiber, so that the linear expansion coefficient difference of the product in different directions is small; If the size ratio of glass fiber and inorganic filler cannot meet the limited range, the product cannot maintain good isotropy and appearance under the condition of high filling amount; If the addition amount ratio of glass fiber and inorganic filler particles is not in the range, even if it meets the size parameter control range, the expected effect cannot be achieved.

[0013] On the other hand, under the setting of the inorganic material, the contact area of inorganic material and organic resin will increase significantly, which may cause the glass fiber, inorganic filler particles or the contained hydroxyl group to migrate out during the contact with PC resin or in the subsequent use process, and then catalyze the degradation of PC resin during high temperature processing or use, which not only leads to the decrease of mechanical strength of the product, but also may cause the difference of linear expansion coefficient in different directions to become larger and the appearance problem, therefore, it is necessary to introduce acidic lubricant to lubricate and acidify the inorganic filler material, but if the acidic lubricant is too high, it may have a great impact on the inorganic filler particles, leading to deformation or damage of the particles, so the acid value needs to be controlled within a certain range.

[0014] Preferably, the PC composition comprises the following components by weight:

[0015] PC resin 43-53 parts, flame retardant 8-12 parts, glass fiber 3-8 parts, inorganic filler particles 30-45 parts, lubricant 0.1-0.5 parts.

[0016] More preferably, the mass content of PC resin in the PC composition is ≥30wt%.

[0017] Preferably, the glass fiber and inorganic filler particles satisfy one or any two of the following ranges: R / D = 0.4, 0.42, 0.45, 0.48, 0.49, 0.5, 0.6, 0.8, 1.0, 1.2, 1.4, 1.5, 1.55, 1.6, 1.8.

[0018] Preferably, the glass fiber and inorganic filler particles satisfy the following:

[0019] 0.6≤R / D≤0.9.

[0020] As described above, by adjusting the aspect ratio of the glass fiber and the particle size of the inorganic filler particles, the two inorganic materials can still be fully combined even at higher addition levels, and the inorganic filler particles can fully encapsulate the glass fiber, resulting in ideal isotropy. Within the above-mentioned preferred range, the difference in the linear expansion coefficient of the obtained product in the horizontal and vertical ranges is further reduced.

[0021] Preferably, the aspect ratio of the retained glass fiber is (20-42):1.

[0022] More preferably, the glass fiber has a retained average diameter of 9 to 15 μm and a retained average length of 280 to 460 μm.

[0023] Preferably, the inorganic filler particles are at least one of talc, kaolin, wollastonite, and mica.

[0024] Preferably, the inorganic filler particles have a retained average particle size of 15–80 μm.

[0025] More preferably, the inorganic filler particles are mica.

[0026] Mica has a layered structure at the microscopic level and theoretically has high anisotropy. However, when combined with glass fiber, based on the control of the size of both by the solution described in this invention, the glass fiber tends to be embedded in the mica powder when mixed with glass fiber to form an inorganic filler material. Based on the multi-faceted friction of these non-spherical particles, the glass fiber is anchored and will not slip relative to the mica powder, resulting in better structural stability and superior isotropy of the product.

[0027] Preferably, in the PC composition, the retained aspect ratio of the glass fibers and the average particle size of the inorganic filler particles are tested and confirmed in the following manner: The PC composition is fired in air, and the resulting ash is filtered and observed by scanning electron microscopy. Elemental analysis is used to confirm the glass fibers and inorganic filler particles. Subsequently, analytical mapping software (graphic recognition software such as Dragonfly) is used to test the length and diameter of the glass fibers and determine the average value. Then, the aspect ratio is calculated, and the particle size of the inorganic filler particles is tested. The number of glass fibers and inorganic filler particles selected is not less than 30. When calculating the average value, the maximum and minimum values ​​of the sample values ​​are removed. For example, if the particle size of 30 inorganic filler particles is tested, and the maximum value is 90 μm and the minimum value is 5 μm, then these two values ​​are removed, and the average value is calculated using the remaining 28 values.

[0028] Preferably, the number-average molecular weight of the PC resin is 15,000 to 30,000.

[0029] Furthermore, the molecular weight of the PC resin is a range of one or both of the following: 15,000, 16,000, 18,000, 20,000, 22,000, 25,000, 28,000, and 30,000.

[0030] Preferably, the number-average molecular weight of the PC resin can be directly detected by gel permeation chromatography.

[0031] Preferably, the flame retardant is a phosphorus-containing flame retardant;

[0032] More preferably, the phosphorus-containing flame retardant is at least one of bisphenol A diphenyl phosphate, resorcinol diphenyl phosphate, triphenyl phosphate, and 4,4'-(isopropylidene diphenyl)bis(diphenyl phosphate).

[0033] Preferably, the lubricant is oxidized polyethylene wax.

[0034] More preferably, the acid value of the lubricant is a range of one or any two of the following: 15mKOH / g, 16mKOH / g, 20mKOH / g, 22mKOH / g, 25mKOH / g, 28mKOH / g, 30mKOH / g, and 32mKOH / g.

[0035] Preferably, the acid value of the lubricant is obtained by testing according to ASTM D1386-15-2022.

[0036] Preferably, the ratio of the total mass of the glass fiber and inorganic filler particles to the mass of the lubricant is (150-225):1.

[0037] Acidic lubricants also have a certain impact on the dispersibility of mixed inorganic fillers and the structural stability after mixing / embedding. Under the above-mentioned preferred ratio, the resulting product can achieve better mechanical strength, dimensional stability and isotropy based on the stability of PC resin and the dispersibility and tight bonding stability of inorganic filler structure.

[0038] Preferably, the PC composition further includes 0.1 to 5 parts of functional additives;

[0039] More preferably, the functional additives include, but are not limited to, at least one of antistatic agents, antibacterial agents, hydrolysis-resistant agents, antioxidants, UV stabilizers, and pigments. Those skilled in the art can add various functional additives as needed without affecting the intended performance of the PC composition of the present invention. For example, to give the PC composition antistatic properties during application, those skilled in the art can add an antistatic agent to the product; to give the PC composition different colors, those skilled in the art can add a small amount of inorganic or organic pigments to the product for dyeing.

[0040] Another object of the present invention is to provide a method for preparing the PC composition, comprising the following steps:

[0041] The components are added to a screw extruder for melt extrusion and granulation to obtain the PC composition.

[0042] Preferably, the temperature zones of the screw extruder are set as follows: Zone 1 220-240℃, Zone 2 220-240℃, Zone 3 220-240℃, Zone 4 240-260℃, Zone 5 240-260℃, Zone 6 240-260℃, Zone 7 240-260℃, Zone 8 240-260℃, Zone 9 240-260℃, Zone 10 240-260℃, and Zone 11 240-260℃; the screw speed is 250-600 rpm; and the screw length-to-diameter ratio is (40-60):1.

[0043] Another object of the present invention is to provide the use of the PC composition in the manufacture of office equipment parts.

[0044] Preferably, the office equipment components include at least one of the following: printer internal support, printer ink cartridge, and equipment housing.

[0045] The PC composition described in this invention is based on the optimized design of the selection and combination of inorganic fillers, and is used in combination with lubricants of specific acid values. This allows the product to have ideal dimensional stability and mechanical strength. At the same time, the product has a small difference in the linear expansion coefficient in the horizontal and vertical directions and good isotropy. Therefore, it is very suitable for office equipment with high requirements for dimensional stability and mechanical strength.

[0046] The beneficial effects of the present invention are that it provides a PC composition that, by optimizing the introduction of inorganic fillers into the components and compounding with specific types of lubricants, can achieve not only high mechanical strength and low linear expansion coefficient with high filler content, but also low anisotropy, small difference in linear expansion coefficient in the horizontal and vertical directions, good appearance, and excellent overall performance. Detailed Implementation

[0047] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments and comparative examples. The purpose of this description is to provide a detailed understanding of the invention, not to limit its scope. All other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention. Unless otherwise specified, the experimental reagents and instruments involved in the implementation of this invention are commonly used reagents and instruments.

[0048] Examples 1-15

[0049] An embodiment of the PC composition, its preparation method and application described in this invention, wherein the components of the PC composition are shown in Table 1.

[0050] The method for preparing the PC composition includes the following steps:

[0051] The components are mixed evenly, and then melt-extruded and granulated in a twin-screw extruder to obtain the PC composition.

[0052] During melt extrusion of the component, the temperature zones of the twin-screw extruder are set as follows: Zone 1 220℃, Zone 2 220℃, Zone 3 230℃, Zone 4 240℃, Zone 5 240℃, Zone 6 250℃, Zone 7 250℃, Zone 8 255℃, Zone 9 260℃, Zone 10 260℃, and Zone 11 260℃. The screw speed is 300 rpm. The screw length-to-diameter ratio is 48:1.

[0053] Comparative Examples 1-9

[0054] The only difference between each comparative example and the embodiment is the type and ratio of components, as shown in Table 2.

[0055] In the components described in each embodiment and comparative example,

[0056] PC resin 1 is 1300-22NP produced by LG Korea, with a number average molecular weight of 22,000.

[0057] PC resin 2 is 1300-10NP produced by LG in South Korea, with a molecular weight of 26,500.

[0058] The flame retardant is FP600, 4,4'-(isopropylidene diphenyl)bis(diphenyl phosphate), manufactured by Idico Japan.

[0059] Glass fiber 1 is ECS13-4.5-534A produced by Jushi Group, with a fiber diameter of 12-15μm and a length of 4300-4600μm;

[0060] Glass fiber 2 is ECS13-03-534A produced by Jushi Group, with a fiber diameter of 12-15μm and a length of 2800-3200μm;

[0061] The glass fiber 3 is a custom-made ECS10-03-568H produced by Jushi Group, with a fiber diameter of 9-11μm and a length of 2800-3200μm;

[0062] Glass fiber 4 is ECS13-4.5-560A produced by Jushi Group, with a fiber diameter of 11-14μm and a length of 4300-4600μm;

[0063] Inorganic filler particle 1 is 325 mesh wet-process mica powder produced by Lingshou County Chuanshi Mineral Products Processing Plant, with an average particle size of 46μm;

[0064] Inorganic filler particles 2 are 325-mesh talc powder produced by Foshan Jinlinda Chemical Co., Ltd., with an average particle size of 45μm;

[0065] Inorganic filler particles 3 are 325-mesh wollastonite produced by Lingshou County Xiangxin Mineral Products Processing Plant, with an average particle size of 45μm.

[0066] Inorganic filler particles 4 are 325-mesh wet-process mica powder produced by Lingshou County Chuanshi Mineral Products Processing Plant. They are ground before use and have an average particle size of 20μm.

[0067] Inorganic filler particles 5 are type 200 wet-process mica powder produced by Lingshou County Chuanshi Mineral Products Processing Plant, with an average particle size of 70μm;

[0068] Inorganic filler particles 6 are 325 mesh talc powder produced by Foshan Jinlinda Chemical Co., Ltd., which are ground before use and have an average particle size of 20μm.

[0069] Lubricant 1 is Honeywell A-C392, an oxidized polyethylene wax with an acid value of 30mKOH / g;

[0070] Lubricant 2 is Honeywell A-C325, an oxidized polyethylene wax with an acid value of 25mKOH / g;

[0071] Lubricant 3 is Honeywell A-C316A, an oxidized polyethylene wax with an acid value of 16mKOH / g;

[0072] Lubricant 4 is Honeywell A-C395, an oxidized polyethylene wax with an acid value of 41mKOH / g;

[0073] Lubricant 5 is Honeywell A-C307, an oxidized polyethylene wax with an acid value of 7.0 mg KOH / g.

[0074] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0075] It should be noted that the aspect ratio of glass fibers and the average particle size of inorganic filler particles in the PC compositions of the various embodiments and comparative examples of the present invention were confirmed by direct testing after the product preparation was completed using the method mentioned above, and the corresponding parameter values ​​of the raw materials used were not adopted.

[0076] Table 1

[0077]

[0078]

[0079]

[0080] Table 2

[0081]

[0082] To verify the performance of the PC composition described in this invention, the products prepared in each embodiment and comparative example were subjected to the following performance tests, with the specific steps as follows:

[0083] (1) Bending modulus test: conducted according to ASTM D790-2010, bending rate 2 mm / min;

[0084] (2) Horizontal / vertical linear expansion coefficient test: The test shall be conducted in accordance with ISO 11359-2-1999, where the horizontal direction is the direction of glue flow and the vertical direction is the direction of glue flow.

[0085] (3) Appearance test: The products of each embodiment and comparative example are injection molded into samples of 80*20*4mm. Then observe whether there are defects such as material spots or floating fibers on the surface of the sample. If they appear, they are recorded as appearance defects.

[0086] The test results are shown in Tables 3 and 4.

[0087] Table 3

[0088]

[0089] Table 4

[0090]

[0091]

[0092] As can be seen from Tables 3 and 4, the PC composition of this invention possesses ideal comprehensive performance. Not only can the flexural modulus be maintained above 10000 MPa, but the horizontal linear expansion coefficient can also be maintained at 33 μm / (m·℃) or below, and the vertical linear expansion coefficient at 45 μm / (m·℃) or below, with the difference between the two maintained at 13 μm / (m·℃) or below. Furthermore, no appearance defects are observed. This is mainly attributed to the special selection of the glass fiber and inorganic filler particles, which gives the product excellent isotropy. When the glass fiber and inorganic filler particles satisfy 0.4 ≤ R / When D ≤ 1.8, the product can meet the standard dimensional stability requirements. Furthermore, when 0.6 ≤ R / D ≤ 0.9, the difference in the linear expansion coefficient of the product in different directions is even smaller, reaching the range of 10-11 μm / (m.℃). However, if the R / D ratio is too high or too low, as shown in Comparative Examples 1 and 2, the product not only has a high linear expansion coefficient, but also a large difference in the linear expansion coefficient in the horizontal and vertical directions, resulting in large anisotropy. It may also fail to meet the bending strength standard. Even if different types of fillers are replaced, as shown in Comparative Example 6, compared to Comparative Example 2, the product still does not show significant performance improvement. On the other hand, the aforementioned limitation needs to be maintained at a specific ratio of glass fiber and inorganic filler. Otherwise, as shown in Comparative Example 3, if the amount of glass fiber is excessive, the product system will not be able to maintain a stable inorganic material skeleton, and the linear expansion coefficient and the difference in linear expansion coefficient in different directions will be unsatisfactory. Furthermore, the acidic lubricant used in the product of this invention is also a key factor in performance. As can be seen in Examples 1 and 16-18, with the introduction of an acidic lubricant with a specific acid value, the difference in linear expansion coefficient in different directions of the product gradually decreases, and the mechanical strength also increases slightly. This is mainly due to the surface of the glass fiber and inorganic filler particles or their contents... The hydroxyl groups may migrate out upon contact with PC resin or during subsequent use, catalyzing the degradation of PC resin during high-temperature processing or use. Using an acidic lubricant can simultaneously lubricate and acid-modify the inorganic materials, inhibiting their effect on the PC resin. However, if a lubricant with too low an acid value is used, as shown in Comparative Example 5, the product not only fails to achieve ideal flexural strength and has a high coefficient of linear expansion, but may also exhibit poor appearance. Conversely, if too much acidic substance is introduced, as shown in Comparative Example 4, the acid value of the used acidic lubricant is too high, causing excessive corrosion of the inorganic materials in the product, resulting in unsatisfactory product performance. However, the filler matching rules described in this invention only apply to products with a high filler content. As shown in Comparative Example 7, in products with a low filler content, the flexural modulus is low, and the coefficient of linear expansion is high, with significant differences in the coefficient of linear expansion at different values.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A PC composition, characterized in that, The components include the following parts by weight: 40-55 parts PC resin, 5-15 parts flame retardant, 1-10 parts glass fiber, 28-48 parts inorganic filler particles, and 0.01-1 part lubricant; The glass fiber and inorganic filler particles satisfy the following: 0.4 ≤ R / D ≤ 1.8; Where R is the retained aspect ratio of the glass fiber, and D is the retained average particle size of the inorganic filler particles, in μm; The acid value of the lubricant is 15~32mKOH / g.

2. The PC composition according to claim 1, characterized in that, The glass fiber and inorganic filler particles satisfy the following: 0.6≤R / D≤0.

9.

3. The PC composition according to claim 1, characterized in that, The aspect ratio of the glass fiber is (20~42):

1.

4. The PC composition according to claim 3, characterized in that, The glass fibers have an average retained diameter of 9-15 μm and an average retained length of 280-460 μm.

5. The PC composition according to claim 1, characterized in that, The inorganic filler particles are at least one of talc, kaolin, wollastonite, and mica.

6. The PC composition according to claim 5, characterized in that, Preferably, the inorganic filler particles have a retained average particle size of 15~80μm.

7. The PC composition according to claim 1, characterized in that, The number average molecular weight of the PC resin is 15,000 to 30,000.

8. The PC composition according to claim 1, characterized in that, The lubricant is oxidized polyethylene wax.

9. The PC composition according to claim 1, characterized in that, The ratio of the total mass of the glass fiber and inorganic filler particles to the mass of the lubricant is (150~225):

1.

10. A method for preparing the PC composition according to any one of claims 1 to 9, characterized in that, Includes the following steps: The components are added to a screw extruder for melt extrusion and granulation to obtain the PC composition.

11. The use of the PC composition according to any one of claims 1 to 9 in the preparation of office equipment parts.

12. The application as described in claim 11, characterized in that, The office equipment components include at least one of the following: printer internal support, printer ink cartridge, and equipment casing.

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