A polycarbonate composition, its preparation and use

Abstract

The present invention relates to a polycarbonate composition, its preparation method and application. The polycarbonate composition comprises the following components by weight: polycarbonate 55-75 parts, ultra-high molecular weight polyethylene 14-36 parts, diamond 2-9 parts, benzene ring-containing phosphate compound 1-9 parts, and compatibilizer 0.5-5 parts. The polycarbonate composition of the present invention has low flexural modulus, hardness and friction coefficient, and has high impact strength, good skin touch, and is very suitable for preparing skin-friendly materials.

Description

Technical Field

[0001] This invention relates to the field of polymer material modification technology, and more specifically, to a polycarbonate composition, its preparation method, and its application. Background Technology

[0002] Skin-friendly materials are those that provide a comfortable and pleasant feeling when in contact with the human body. Common applications include medical devices, children's toys, kitchenware, and bedding. Skin-friendly materials possess a certain degree of elasticity, flexibility, and friction reduction, and can minimize reactions upon contact with the skin.

[0003] Polycarbonate (PC) is a highly transparent amorphous thermoplastic and one of the five major engineering plastics, with a wide range of applications.

[0004] However, polycarbonate has a high flexural modulus of 2200-2500 MPa (ISO 178 standard), lacking elastic deformation capacity upon contact and easily forming localized pressure points on the skin. Simultaneously, polycarbonate has low toughness, high hardness, and insufficient flexibility, resulting in poor comfort when touched by human skin. Furthermore, while polycarbonate has a smooth surface, it is highly polar, with a dry friction coefficient of 0.3-0.5 (ASTM D1894) with skin, far exceeding that of skin-friendly materials such as silicone (0.1-0.2) or hydrogels (<0.1). This makes polycarbonate prone to causing micro-damage to the epidermis due to dynamic friction. All these factors make polycarbonate unsuitable as a skin-friendly material.

[0005] A Chinese patent titled "Copolyester Composition with Low Coefficient of Friction" incorporates additives such as waxes and organosiloxanes into the polymer composition to reduce the coefficient of friction, and uses impact modifiers to improve impact toughness, thus solving the problem of high coefficient of friction in existing polymer compositions. However, the hardness and flexural modulus of this patent are still relatively high, resulting in poor skin-friendly comfort when used as a skin-friendly material. Summary of the Invention

[0006] The primary objective of this invention is to overcome the problem that current PC materials are difficult to use as skin-friendly materials, and to provide a polycarbonate composition.

[0007] A further object of the present invention is to provide a method for preparing the above-described polycarbonate composition.

[0008] A further object of the present invention is to provide the use of the above-described polycarbonate composition in the preparation of skin-friendly parts.

[0009] A further objective of this invention is to provide a skin-friendly component.

[0010] The above-mentioned objective of the present invention is achieved through the following technical solution: A polycarbonate composition, characterized in that it comprises the following components in parts by weight: 55-75 parts polycarbonate 14-36 parts of ultra-high molecular weight polyethylene 2-9 parts diamond 1-9 parts of phosphate ester compounds containing benzene rings, Compatibilizer 0.5 to 5 parts.

[0011] Ultra-high molecular weight polyethylene (UHMWPE) can impart high impact strength and a low coefficient of friction to polycarbonate compositions; furthermore, the addition of UHMWPE can reduce the flexural modulus and stiffness of polycarbonate compositions. However, the coefficient of friction of polycarbonate compositions still needs to be further reduced to meet the requirements for their use as skin-friendly materials.

[0012] The inventors of this invention have discovered that by simultaneously adding diamond and a benzene-ring-containing phosphate ester compound, the low coefficient of friction of diamond and the protective effect of the benzene-ring-containing phosphate ester compound on ultra-high molecular weight polyethylene can synergistically and significantly reduce the coefficient of friction of the polycarbonate composition. At the same time, the benzene-ring-containing phosphate ester compound can also avoid the negative impact on impact strength caused by the addition of diamond, thus maintaining the impact strength of the polycarbonate composition.

[0013] The polycarbonate composition of the present invention has low flexural modulus, hardness and coefficient of friction, as well as high impact strength and good skin feel, making it very suitable for use in the preparation of skin-friendly materials.

[0014] In this invention, the amount of polycarbonate used can be 55, 57, 59, 61, 63, 65, 68, 70, 72, or 75 parts by weight, or any two of the above values ​​within a range; the amount of ultra-high molecular weight polyethylene used can be 14, 16, 18, 20, 23, 25, 28, 30, 32, 34, or 36 parts by weight, or any two of the above values ​​within a range; the amount of diamond used can be 2, 4, 6, 8, or 9 parts by weight, or any two of the above values ​​within a range; the amount of phosphate ester compound containing a benzene ring used can be 1, 2, 4, 6, 8, or 9 parts by weight, or any two of the above values ​​within a range; and the amount of compatibilizer used can be 0.5, 1, 2, 3, 4, or 5 parts by weight, or any two of the above values ​​within a range.

[0015] In this invention, polycarbonate is used as the main resin, and its content accounts for more than 40 wt% of the polycarbonate composition.

[0016] Preferably, the polycarbonate has a melt index of 3~30g / 10min measured at 300℃ and 1.2kg.

[0017] In this invention, the melt index of polycarbonate can be measured according to the GB / T3682.1-2018 standard.

[0018] Preferably, the polycarbonate is at least one of bisphenol A type polycarbonate or silicon copolymer polycarbonate.

[0019] More preferably, the polycarbonate comprises at least 30 wt% of silicon-copolymerized polycarbonate.

[0020] More preferably, the polycarbonate comprises 30-80% silicon copolymer polycarbonate.

[0021] More preferably, the polycarbonate comprises 40-80% silicon copolymer polycarbonate.

[0022] By controlling the content of silicon copolymer polycarbonate in polycarbonate within this range, the resulting polycarbonate composition has lower flexural modulus and hardness, higher impact strength, and lower surface friction coefficient.

[0023] Preferably, the weight-average molecular weight of the ultra-high molecular weight polyethylene is 1,200,000 to 3,500,000; specifically, it can be 1,200,000, 1,400,000, 1,500,000, 1,800,000, 2,000,000, 2,300,000, 2,500,000, 2,800,000, 3,000,000, 3,200,000, 3,500,000, or a range formed by any two of the above values.

[0024] In this invention, the weight-average molecular weight of the ultra-high molecular weight polyethylene can be measured according to ASTM D6474-2012, under the following conditions: the sample is dissolved in 1,2,4-trichlorobenzene at high temperature (>140℃), the molecular chains are separated by chromatographic column, and the weight-average molecular weight is calculated by combining the standard curve.

[0025] More preferably, the weight-average molecular weight of the ultra-high molecular weight polyethylene is 2,300,000 to 3,000,000.

[0026] By controlling the weight-average molecular weight of ultra-high molecular weight polyethylene within this range, the resulting polycarbonate composition exhibits lower hardness, higher impact strength, and a lower surface friction coefficient.

[0027] Preferably, the diamond is nanodiamond.

[0028] Preferably, the D50 particle size of the diamond is 10~150nm.

[0029] Preferably, the D50 particle size of the diamond is 25-40 nm. By controlling the particle size within this range, the polycarbonate composition exhibits lower flexural modulus, better impact strength, and a lower coefficient of friction.

[0030] In this invention, the D50 particle size of the diamond can be measured according to ISO22412:2024. Preferably, the benzene ring-containing phosphate compound is at least one of bisphenol A-bis(diphenyl phosphate) or tetraphenylresorcinol diphosphate.

[0031] More preferably, the benzene ring-containing phosphate compound is bisphenol A-bis(diphenyl phosphate).

[0032] The selected phosphate compound containing a benzene ring is bisphenol A-bis(diphenyl phosphate), which results in a polycarbonate composition with a lower flexural modulus, better impact strength, and a lower coefficient of friction.

[0033] Preferably, the compatibilizer is a maleic anhydride-grafted elastomer.

[0034] More preferably, the maleic anhydride-grafted elastomer is at least one of maleic anhydride-grafted SEBS or maleic anhydride-grafted POE.

[0035] Preferably, the polycarbonate composition further includes 0.1 to 3 parts of other additives.

[0036] More preferably, the other additives are at least one of lubricants and antioxidants.

[0037] More preferably, the amount of the lubricant used is 0.1 to 1 part, including but not limited to oxidized polyethylene wax.

[0038] More preferably, the amount of the antioxidant is 0.1 to 1 part, including but not limited to octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and at least one of tris(2,4-di-tert-butylphenyl) phosphite or pentaerythritol tetra(3-dodecylthiopropionate) as a co-antioxidant.

[0039] The preparation method of the above polycarbonate composition includes the following steps: mixing the components, melt extruding, and granulating to obtain the polycarbonate composition.

[0040] Preferably, the temperature of the melt extrusion is 140~270℃; the screw speed of the extruder for the melt extrusion is 300~600RPM, and the length-to-diameter ratio of the screw is 36~48:1.

[0041] The application of the above-mentioned polycarbonate composition in the preparation of skin-friendly parts is also within the scope of protection of this invention.

[0042] A skin-friendly component is prepared from the above-mentioned polycarbonate composition.

[0043] Preferably, the skin-friendly component is a robot hand component, a robot head component, an earphone case, or an eyeglass case.

[0044] Compared with the prior art, the beneficial effects of the present invention are: The polycarbonate composition of the present invention has low flexural modulus, hardness and coefficient of friction, as well as high impact strength and good skin feel, making it very suitable for use in the preparation of skin-friendly materials. Detailed Implementation

[0045] To more clearly and completely describe the technical solution of the present invention, the present invention will be further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Various changes can be made within the scope of the claims of the present invention.

[0046] The reagents used in the various embodiments and comparative examples of this invention are described below: Polycarbonate 1#: Bisphenol A type polycarbonate, grade PC CH9115LT, manufacturer: Cangzhou Dahua, MFR=9g / 10min; Polycarbonate 2#: Silicon copolymer polycarbonate, grade PC A1050, manufacturer Wanhua Chemical, MFR=5g / 10min; Polycarbonate 3#: Bisphenol A type polycarbonate, grade PC CH8225, manufacturer: Cangzhou Dahua, MFR=20g / 10min; The MFR of the above polycarbonate was tested at 300℃ and 1.2 kg. Ultra-high molecular weight polyethylene 1#: Grade UH150P, manufacturer Celanese, weight average molecular weight is approximately 1,500,000; Ultra-high molecular weight polyethylene #2: Grade SEU-250E, manufacturer Yanshan Petrochemical, weight average molecular weight is approximately 2,500,000; Ultra-high molecular weight polyethylene #3: Grade 9300CG, manufacturer: Yanshan Petrochemical, weight average molecular weight is 3,000,000; Ordinary polyethylene: grade DGDA6098, Sinopec, weight average molecular weight approximately 100,000; Diamond 1#: DND-30, GRISH, D50 particle size 35nm; Diamond #2: DND-100, GRISH, D50 particle size 90nm; Compatibilizers: FG1901, Kraton, maleic anhydride-grafted SEBS; Benzene ring-containing phosphate ester compound 1#: Bisphenol A-bis(diphenyl phosphate), WSFR-BDP-N2, Zhejiang Wansheng; 2# Phosphate esters containing benzene rings: Tetraphenylresorcinol diphosphate, STAB PFR, Idico; Triethyl phosphate: Commercially available; Other additives #1: Antioxidant, Revonox 608, commercially available; Other additives #2: Lubricant, LICOWAXPED 521, commercially available; Unless otherwise specified, all components (e.g., compatibilizer, other additive 1#, other additive 2#) used in each parallel embodiment and comparative example are the same commercially available products.

[0047] The polycarbonate compositions provided in the embodiments and comparative examples of the present invention were subjected to performance testing according to the following test methods: (1) Flexural modulus test: ISO 178-2019; (2) Notched impact strength: ISO 180-2023, notch type is Type A notch; (3) Hardness Shore D: ISO 7619-1-2010; (4) Coefficient of friction: According to ASTM D1894-2014: the polycarbonate composition was injection molded into a test plate of 63.5mm×63.5mm, the test speed was controlled at 150±30mm / min, and a standard slider (stainless steel material) with a mass of 200±5g was used. The coefficient of friction was calculated by the ratio of frictional force to vertical normal force. Five test plates were tested for each example and the proportion of the comparison, and then the average value was calculated.

[0048] The preparation processes of the polycarbonate compositions in the various embodiments and comparative examples of the present invention are as follows: Weigh each component according to the formula, mix them, and then add them to a twin-screw extruder for melt extrusion and granulation to obtain a polycarbonate composition. The temperature settings of each zone of the screw extruder are 140℃, 200℃, 240℃, 260℃, 250℃, 250℃, 250℃, 260℃, 250℃, and 270℃, respectively; the screw speed is 500 rpm; and the screw length-to-diameter ratio is 40:1.

[0049] Examples 1-11 Examples 1-11 provide a series of polycarbonate compositions, the formulations of which are shown in Tables 1 and 2.

[0050] Table 1. Formulations (parts by weight) for Examples 1-7

[0051] Table 2. Formulations (parts by weight) for Examples 8-11

[0052] Comparative Examples 1-7 Comparative Examples 1-7 provide a series of polycarbonate compositions, the formulations of which are shown in Table 3.

[0053] Table 3. Formulations (parts by weight) for Comparative Examples 1-7

[0054] The properties of the polycarbonate compositions of each embodiment and comparative example were determined according to the test methods mentioned above, and the test results are shown in Table 4. Table 4 Performance results of the polycarbonate compositions of each example and comparative example

[0055] As can be seen from Table 4: The polycarbonate compositions of Examples 1-11 all have a flexural modulus of 1752 MPa or less and an impact strength of 50 kJ / m. 2 All have a Shore hardness of 95 or below and a surface friction coefficient of 0.18 or below.

[0056] Comparative Example 1, without the addition of ultra-high molecular weight polyethylene and replaced with an equal amount of ordinary polyethylene, showed that the polycarbonate composition had too high a flexural modulus, too low an impact strength, too high a hardness, and too high a coefficient of friction.

[0057] Comparative Example 2, without the addition of ultra-high molecular weight polyethylene, exhibits a polycarbonate composition with a high flexural modulus, low impact strength, high hardness, and a high coefficient of friction.

[0058] Comparative Example 3, without the addition of diamond or phosphate compounds containing benzene rings, showed a high surface friction coefficient in the polycarbonate composition.

[0059] In Comparative Example 4, without the addition of diamond, the coefficient of friction of the polycarbonate composition was still relatively high.

[0060] Comparative Example 5, without the addition of phosphate compounds containing benzene rings, resulted in a polycarbonate composition with low impact strength and a high coefficient of friction.

[0061] Comparative Example 6, without diamond and instead using an equal amount of talc, showed that the polycarbonate composition had low impact strength and a high coefficient of friction.

[0062] Comparative Example 7, which did not include any benzene ring-containing phosphate esters and instead used an equal amount of triethyl phosphate, showed that the polycarbonate composition had low impact strength and a high coefficient of friction.

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A polycarbonate composition, characterized in that, The components include the following parts by weight: 55-75 parts polycarbonate 14-36 parts of ultra-high molecular weight polyethylene 2-9 parts diamond 1-9 parts of phosphate ester compounds containing benzene rings, Compatibilizer 0.5 to 5 parts.

2. The polycarbonate composition according to claim 1, characterized in that, The polycarbonate measured at 300℃ and 1.2kg had a melt index of 3~30g / 10min.

3. The polycarbonate composition according to claim 1, characterized in that, The polycarbonate comprises at least 30 wt% silicon-copolymerized polycarbonate.

4. The polycarbonate composition according to claim 1, characterized in that, The weight-average molecular weight of the ultra-high molecular weight polyethylene is 1,200,000 to 3,500,000.

5. The polycarbonate composition according to claim 1, characterized in that, The diamond is nanodiamond.

6. The polycarbonate composition according to claim 1, characterized in that, The benzene ring-containing phosphate compound is at least one of bisphenol A-bis(diphenyl phosphate) or tetraphenylresorcinol diphosphate.

7. The polycarbonate composition according to claim 1, characterized in that, The polycarbonate composition also includes 0.1 to 3 parts of other additives.

8. A method for preparing the polycarbonate composition according to any one of claims 1 to 7, characterized in that, The process includes the following steps: mixing the components, melt extruding, and granulating to obtain the polycarbonate composition.

9. The use of the polycarbonate composition according to any one of claims 1 to 7 in the preparation of skin-friendly parts.

10. A skin-friendly component, characterized in that, It is prepared from the polycarbonate composition according to any one of claims 1 to 7.

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