Modified polycarbonate composition, polycarbonate film as well as preparation method and application of polycarbonate film

Abstract

The invention discloses a modified polycarbonate composition, which is prepared from the following raw materials in parts by weight: 100 parts of polycarbonate, 20 to 25 parts of impact modifier, 15 to 20 parts of toughening modifier, 10 to 15 parts of filler, 0.1 to 0.5 part of lubricant and 0.1 to 0.5 part of slip agent, the slip agent is formed by mixing an amide slip agent and hyperbranched polysiloxane according to the weight ratio of 1: (0.5-1); the preparation method of the hyperbranched polysiloxane comprises the following steps: mixing water and polysiloxane in a molar ratio of 1: (0.7-0.9), dropwise adding a pH regulator to regulate the pH value to 1-2, pre-hydrolyzing the reaction system at 25-30 DEG C for 10-15 minutes while stirring, heating to 50-60 DEG C, carrying out reflux reaction for 5-8 hours, and drying the obtained liquid to obtain the hyperbranched polysiloxane. The modified polycarbonate composition has excellent wear resistance and is suitable for manufacturing a mouse or a touchpad. The invention correspondingly provides a polycarbonate film taking the composition as a raw material and a preparation method of the polycarbonate film.

Description

Technical Field

[0001] The present application relates to the field of polycarbonate materials, and in particular to a modified polycarbonate composition, a polycarbonate film, and a preparation method and application thereof. Background Art

[0002] Touchpads are widely used input devices in laptops, and are generally made of PC (Polycarbonate) materials. Users' fingers are greasey or dusty, and they swipe on the touchpad surface for a long time, so the performance of the touchpad is very high, especially the wear resistance. However, ordinary PC materials have poor wear resistance, and the middle area of ​​the laptop touchpad will become shiny after being used for a period of time.

[0003] To address this problem, the existing technology usually applies two layers of light-curing coating on the surface of the PC substrate to improve wear resistance. On the one hand, this method requires two coatings, which increases the complexity of the touch panel preparation process and material loss; on the other hand, ordinary light-curing coatings have poor wear resistance and the attenuation rate is too high with the increase of friction times. The wool felt performance test shows that the attenuation rate exceeds 30% after 400,000 times / 200g, which easily causes the touch panel surface coating to be scratched, affecting the use and appearance.

[0004] Therefore, a new solution is needed to address the problem of poor wear resistance of PC materials used to make touch panels. Summary of the invention

[0005] In order to solve the problem of poor wear resistance of PC materials used in touch panel manufacturing, the present invention provides a modified polycarbonate composition, a polycarbonate film, and a preparation method and application thereof.

[0006] In a first aspect, the present invention provides a modified polyester composition, which specifically adopts the following technical solution.

[0007] A modified polycarbonate composition comprises the following raw materials in parts by weight:

[0008] Polycarbonate 100 parts

[0009] Impact modifier 20-25 parts

[0010] Toughening modifier 15-20 parts

[0011] Filler 10-15 parts

[0012] Lubricant 0.1-0.5 parts

[0013] Slip agent 0.1-0.5 parts

[0014] The slip agent is prepared by mixing an amide slip agent and a hyperbranched polysiloxane in a weight ratio of 1:(0.5-1); wherein the hyperbranched polysiloxane is prepared according to the following steps:

[0015] Water and polysiloxane are mixed in a molar ratio of 1:(0.7-0.9), a pH adjuster is added dropwise to adjust the pH value to 1-2, and the reaction system is pre-hydrolyzed at 25-30° C. for 10-15 minutes while stirring, and then the temperature is raised to 50-60° C., and the resulting liquid is dried after reflux reaction for 5-8 hours to obtain hyperbranched polysiloxane.

[0016] By adopting the above technical scheme, the modified polycarbonate composition prepared by compounding and modifying the impact modifier, toughening modifier, filler, lubricant and slip agent has excellent wear resistance and is suitable for making mouse and touchpad products with high wear resistance requirements. The wool felt performance test can reach more than 400,000 times / 200g. At the same time, it can be found from the experimental results that the amide slip agent and the hyperbranched polysiloxane are compounded in a specific ratio, and the two can synergistically play a role in improving the wear resistance of the polycarbonate material.

[0017] Furthermore, the amide lubricant is a saturated fatty amide and / or an unsaturated fatty amide.

[0018] Furthermore, the amide lubricant is one or more of oleamide, erucamide and stearamide.

[0019] Furthermore, the impact modifier is a mixture of one or more of ABS, PS, PBT and PA.

[0020] Furthermore, the toughening modifier is EPDM, POE or a mixture of the two.

[0021] Furthermore, the lubricant is a mixture of one or more of polytetrafluoroethylene, silicone oil and paraffin oil.

[0022] Furthermore, the filler is a powder filler and / or a fiber filler, the powder filler is molybdenum disulfide and / or graphite, and the fiber filler is one or more of carbon fiber, glass fiber, and aramid fiber.

[0023] In a second aspect, the present invention provides a polycarbonate film prepared from any of the above-mentioned modified polycarbonate compositions.

[0024] In a third aspect, the present invention provides a method for preparing a polycarbonate film, using any of the modified polycarbonate compositions described above as a raw material. The method for preparing a polycarbonate film provided by the present invention specifically comprises the following steps:

[0025] Granule drying: Dehumidifying and drying the modified polycarbonate composition until the water content does not exceed 0.1wt% to obtain a dry raw material; preferably, the water content does not exceed 0.08wt%, and more preferably, the water content does not exceed 0.05wt%;

[0026] Vacuum feeding: the dry raw materials are fed into the feeding hopper of the extruder by vacuuming;

[0027] Extrusion molding: The aforementioned dry raw materials are heated and melted by the extruder and then extruded, and then pass through the screen changer, melt pump and flow channel into the mold cavity, and then flow into the roller group for extrusion to form a polycarbonate film with a width of 1000-1500mm and a thickness of 0.1-0.5mm.

[0028] Among them, the pellet drying step can be carried out in a stainless steel material tank, and the drying time is generally 4-8h, depending on the moisture content of the material before drying; a screw extruder can be used in the extrusion molding step, and the extruder speed is 50-70r / min, preferably 55-65r / min, and further preferably 60r / min; the temperatures of the front, middle and rear parts of the extruder barrel are 230-250°C, 250-270°C, 265-280°C, preferably 235-245°C, 255-265°C, 270-275°C, and further preferably 240°C, 260°C, and 275°C; the roller group includes three rollers, the upper roller temperature is 25-35°C, the middle roller temperature is 130-140°C, and the lower roller temperature is 125-135°C, preferably the upper roller temperature is 30°C, the middle roller temperature is 135°C, and the lower roller temperature is 130°C.

[0029] In a fourth aspect, the modified polyester composition of the present invention can be used to manufacture a mouse or a touch pad. The mouse or the touch pad made from the modified polyester composition of the present invention has excellent wear resistance and can meet the increasingly stringent wear resistance requirements of the industry. DETAILED DESCRIPTION

[0030] The present application is described in further detail below.

[0031] [Preparation Example 1-3]

[0032] Preparation Examples 1-3 all relate to a method for preparing a hyperbranched polysiloxane, and the steps are as follows:

[0033] Water and polysiloxane are mixed in a molar ratio of 1:(0.7-0.9), hydrochloric acid is added dropwise to adjust the pH value to 1-2, and the reaction system is pre-hydrolyzed at 25-30° C. for 10-15 minutes while stirring, and then the temperature is raised to 50-60° C., and the resulting liquid is dried after reflux reaction for 5-8 hours to obtain hyperbranched polysiloxane.

[0034] The difference between Preparation Examples 1-3 is that the process parameters are different, see Table 1 for details.

[0035] Table 1. Process parameters of each preparation example

[0036]

[0037]

[0038] [Examples 1-7]

[0039] Examples 1-7 all relate to a modified polycarbonate composition, which is obtained by mixing and granulating raw materials in the proportions shown in Table 2.

[0040] Table 2. Raw material ratios of Examples 1-7

[0041] raw material Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Polycarbonate / kg 100 100 100 100 100 100 100 ABS / kg 20 22 25 25 25 25 25 EPDM / kg 20 18 15 15 15 15 15 Filler / kg 10 12 15 15 15 15 15 Paraffin oil / kg 0.1 0.3 0.5 0.5 0.5 0.5 0.5 Slip agent / kg 0.1 0.1 0.1 0.25 0.5 0.5 0.5

[0042] The fillers in Examples 1-7 all include molybdenum disulfide and glass fiber, and the weight ratio of the two is 1:1.

[0043] The slip agents in Examples 1-7 are all obtained by mixing oleamide, stearamide and the hyperbranched polycarbonate prepared in Preparation Example 1. The weight ratio of oleamide, stearamide and hyperbranched polycarbonate in the slip agents of Examples 1-5 is 5:5:7, the weight ratio of oleamide, stearamide and hyperbranched polycarbonate in the slip agent of Example 6 is 5:5:8, and the weight ratio of oleamide, stearamide and hyperbranched polycarbonate in the slip agent of Example 7 is 5:5:9.

[0044] Lubricants are conventional components, and one or more of polytetrafluoroethylene, silicone oil and paraffin oil can be selected. The amount used is based on the conventional amount used in the art. In the embodiments of this application, only paraffin oil is used as an example. Similarly, fillers are conventional components, and powder fillers, fiber fillers or a mixture of the two can be selected; specifically, powder fillers can be molybdenum disulfide, graphite, etc., and fiber fillers can be carbon fibers, glass fibers, aramid fibers, etc.; in the embodiments of this application, only a mixture of molybdenum disulfide and glass fibers is used as an example of fillers. When implementing the present invention, the type of filler can be selected and the amount can be adjusted as needed.

[0045] [Examples 8-9]

[0046] Examples 8-9 all relate to a modified polycarbonate composition, and are based on Example 7, except that:

[0047] The hyperbranched polysiloxane in the slip agent of Example 8 is prepared by Preparation Example 2;

[0048] The hyperbranched polysiloxane in the slip agent of Example 9 is prepared by Preparation Example 3.

[0049] [Examples 10-14]

[0050] Examples 10-14 all relate to a modified polycarbonate composition, and are all based on Example 7, with the difference being that the selection of the impact modifier and the toughening modifier is different, as shown in Table 3 for details.

[0051] Table 3. Raw material ratio table of Examples 1-7

[0052] raw material Example 7 Example 10 Embodiment 11 Example 12 Embodiment 13 Embodiment 14 Polycarbonate / kg 100 100 100 100 100 100 ABS / kg 25 0 0 10 15 0 PS / kg 0 15 0 5 10 20 PBT / kg 0 10 25 0 0 5 PA / kg 0 0 0 10 0 0 EPDM / kg 15 10 5 10 5 0 POE / kg 0 5 10 5 10 15 Filler / kg 15 15 15 15 15 15 Paraffin oil / kg 0.5 0.5 0.5 0.5 0.5 0.5 Slip agent / kg 0.5 0.5 0.5 0.5 0.5 0.5

[0053] [Comparative Examples 1-4]

[0054] Comparative Examples 1-4 all relate to a modified polycarbonate composition, all based on Example 7, except that:

[0055] In Comparative Example 1, the lubricant is a mixture of oleic acid amide and stearic acid amide in a weight ratio of 1:1;

[0056] In Comparative Example 2, the slip agent contains only hyperbranched polysiloxane;

[0057] The weight ratio of oleamide, stearamide and hyperbranched polycarbonate in the slip agent in Comparative Example 3 is 1:1:1;

[0058] The weight ratio of oleamide, stearamide and hyperbranched polycarbonate in the slip agent in Comparative Example 4 is 1:1:2.

[0059] [Application Examples]

[0060] The modified polycarbonate compositions of Examples 1-16 and Comparative Examples 1-4 were used as raw materials to prepare polycarbonate films according to the following method. The specific steps are as follows:

[0061] Granule drying: the modified polycarbonate composition is subjected to dehumidification drying for 4-8 hours until the water content does not exceed 0.1 wt % to obtain a dry raw material;

[0062] Vacuum feeding: the dry raw materials are fed into the feeding hopper of the extruder by vacuuming;

[0063] Extrusion molding: the aforementioned dry raw materials are heated and melted by a screw extruder and then extruded. The speed of the extruder is 65r / min, and the temperatures of the front, middle and rear parts of the extruder barrel are 240°C, 260°C and 275°C respectively; they pass through the screen changer, melt pump and runner in turn into the mold cavity, and then flow into the three-roll roller group to extrude to form a polycarbonate film with a width of 1200mm and a thickness of 0.3-0.4mm. The upper roller temperature of the roller group is 30°C, the middle roller temperature is 135°C, and the lower roller temperature is 130°C.

[0064] The polycarbonate film prepared through the above steps has excellent wear resistance and is suitable for making a touch panel for a notebook computer.

[0065] [Performance test]

[0066] 1. Wool felt resistance

[0067] Cut the polycarbonate film obtained in the application example of A4 size as a sample, fix the sample on the abrasion tester, add the weight and the rod weight to 200g, and use the special wool felt for abrasion test. The abrasion tester rotates 30 times / minute, the distance is 4cm, and the test is 300,000 times / 400,000 times / 500,000 times respectively. After the test is completed, wipe the abrasion marks with alcohol cotton pads. After the alcohol evaporates, visually check whether there are scratches or luminous areas on the surface of the sample. If there are luminous areas or scratches on the surface of the sample, it means that the test fails. Record the pass or fail as the test result (pass: ○, fail: ×). The test results are detailed in Table 4.

[0068] 2. Wear test

[0069] Cut a 10mm*6mm*20mm polycarbonate film as a sample and perform a wear test on a wear tester, and record the wear amount as the test result. Test conditions: wear disc diameter 122mm, rotation speed 190rpm, hardness 60HRC, surface roughness Ra=0.4μm, grinding time 3h, load 30kg. The test results are detailed in Table 4.

[0070] Table 4. Performance test results

[0071]

[0072]

[0073] It can be seen from the experimental results that the polycarbonate film prepared by the modified polycarbonate composition of the present invention has excellent wear resistance, and the wool felt resistance performance test is qualified at 400,000 times / 200g, and the preferred solution wool felt resistance performance test is qualified at 500,000 times / 200g, and the wear loss does not exceed 3.4g. At the same time, it can be seen from the experimental results that the blend of amide slip agent and hyperbranched polysiloxane in the weight ratio range of 1: (0.5-1) as a slip agent can significantly improve the wear resistance of the polycarbonate film. When only amide slip agent or hyperbranched polysiloxane is added, or the weight ratio of the two exceeds the aforementioned range, the effect of improving the wear resistance is significantly reduced. It can be seen that amide slip agent and hyperbranched polysiloxane have the effect of synergistically improving the wear resistance of polycarbonate materials.

[0074] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A modified polycarbonate composition, characterized in that: The invention comprises the following raw materials in parts by weight: The slip agent is prepared by mixing an amide slip agent and a hyperbranched polysiloxane in a weight ratio of 1:(0.5-1); wherein the hyperbranched polysiloxane is prepared according to the following steps: Water and polysiloxane are mixed in a molar ratio of 1:(0.7-0.9), a pH adjuster is added dropwise to adjust the pH value to 1-2, and the reaction system is pre-hydrolyzed at 25-30° C. for 10-15 minutes while stirring, and then the temperature is raised to 50-60° C., and the resulting liquid is dried after reflux reaction for 5-8 hours to obtain hyperbranched polysiloxane.

2. The modified polycarbonate composition according to claim 1, characterized in that: The amide lubricant is a saturated fatty amide and / or an unsaturated fatty amide.

3. The modified polycarbonate composition according to claim 2, characterized in that: The amide lubricant is one or more of oleamide, erucamide and stearamide.

4. The modified polycarbonate composition according to any one of claims 1 to 3, characterized in that: The impact modifier is a mixture of one or more of ABS, PS, PBT and PA.

5. The modified polycarbonate composition according to any one of claims 1 to 3, characterized in that: The toughening modifier is EPDM, POE or a mixture of the two.

6. The modified polycarbonate composition according to any one of claims 1 to 3, characterized in that: The lubricant is a mixture of one or more of polytetrafluoroethylene, silicone oil and paraffin oil.

7. The modified polycarbonate composition according to any one of claims 1 to 3, characterized in that: The filler is a powder filler and / or a fiber filler, the powder filler is molybdenum disulfide and / or graphite, and the fiber filler is one or more of carbon fiber, glass fiber, and aramid fiber.

8. A polycarbonate film, characterized in that The polycarbonate composition is prepared from the modified polycarbonate composition according to any one of claims 1 to 7.

9. A method for preparing a polycarbonate film, characterized in that: The steps include: Granule drying: dehumidifying and drying the modified polycarbonate composition according to any one of claims 1 to 7 until the water content does not exceed 0.1 wt % to obtain a dry raw material; Vacuum feeding: the dry raw materials are fed into the feeding hopper of the extruder by vacuuming; Extrusion molding: The aforementioned dry raw materials are heated and melted by an extruder and then extruded, and then pass through a screen changer, a melt pump and a flow channel to enter the mold cavity, and then flow into a roller group for extrusion to form a polycarbonate film.

10. Use of the modified polycarbonate composition according to any one of claims 1 to 7 in the manufacture of a mouse or a touch pad.

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