Radiation-resistant solvent-resistant polycarbonate composition as well as preparation method and application thereof

Abstract

The invention relates to an irradiation-resistant solvent-resistant polycarbonate composition as well as a preparation method and application thereof, and belongs to the technical field of compositions of high-molecular compounds. The radiation-resistant and solvent-resistant polycarbonate composition disclosed by the invention is prepared from the following components in parts by weight: 90 to 100 parts of polycarbonate, 0.05 to 1 part of polybutylene terephthalate, 0.05 to 1 part of a triazine ultraviolet light absorber and 0.02 to 1 part of a phosphite stabilizer, the melt mass flow rate of the polybutylene terephthalate under the conditions of 250 DEG C and 2.16 kg is greater than or equal to 12 g / 10 min. The polycarbonate composition has good mechanical properties and excellent solvent resistance after being subjected to UVC radiation.

Description

Technical Field

[0001] This invention relates to the field of polymer composition technology, and more particularly to a radiation-resistant and solvent-resistant polycarbonate composition, its preparation method, and its application. Background Technology

[0002] UVC radiation disinfection is a technology that uses electromagnetic radiation in the 200nm to 275nm wavelength range to kill microorganisms. It primarily works by disrupting the DNA or RNA structure of microorganisms, preventing them from replicating and multiplying, thus inactivating viruses, bacteria, and other pathogens. However, in the field of robotics, especially medical robots, their windows and other related transparent components are mostly made of polycarbonate. Polycarbonate undergoes photorearrangement and photooxidation reactions when exposed to short-wave radiation. Repeated UVC radiation disinfection not only leads to a decrease in the mechanical properties of robot components but also causes surface cracking when wiped with disinfectants such as alcohol, resulting in poor operational stability of the robot. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a radiation-resistant and solvent-resistant polycarbonate composition, its preparation method, and its application.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a radiation-resistant and solvent-resistant polycarbonate composition, comprising, by weight, the following components: 90-100 parts of polycarbonate, 0.05-1 part of polybutylene terephthalate, 0.05-1 part of triazine ultraviolet absorber, and 0.02-1 part of phosphite stabilizer; wherein the polybutylene terephthalate has a melt flow rate ≥12 g / 10 min under conditions of 250°C and 2.16 kg (test standard is ASTM D1238).

[0005] This invention combines polybutylene terephthalate (PET) with a triazine UV absorber at a specific melt flow rate. By controlling the melt flow rate of PET, it is uniformly dispersed in the continuous polycarbonate phase, while most of the triazine UV absorber is distributed in or around the PET phase. PET carries the triazine UV absorber to the surface of the polycarbonate composition, forming a protective film that effectively absorbs short-wave radiation and blocks solvent molecule penetration. Simultaneously, this film, combined with phosphite stabilizers mainly dispersed within the polycarbonate composition, further captures free radicals to inhibit photo-rearrangement and photo-oxidation reactions in polycarbonate, significantly mitigating its degradation and thus significantly improving the mechanical properties and solvent resistance of the polycarbonate composition.

[0006] It should also be noted that the polycarbonate in the above-mentioned radiation-resistant and solvent-resistant polycarbonate composition is the matrix resin, and its mass percentage is ≥90%.

[0007] In some embodiments, the weight parts of polycarbonate in the radiation-resistant and solvent-resistant polycarbonate composition may be, but are not limited to, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100 parts, or fall within the range of any two of the above values.

[0008] In some embodiments, the weight parts of polybutylene terephthalate in the radiation-resistant and solvent-resistant polycarbonate composition may be, but are not limited to, 0.05 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, or 1 part, or fall within the range of any two of the above values.

[0009] In some embodiments, the weight percentage of the triazine UV absorber in the radiation-resistant and solvent-resistant polycarbonate composition may be, but is not limited to, 0.05 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, or 1 part, or fall within the range of any two of the above values.

[0010] In some embodiments, the weight percentage of the phosphite stabilizer in the radiation-resistant and solvent-resistant polycarbonate composition may, but is not limited to, 0.02 parts, 0.05 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, or 1 part, or fall within the range of any two of the above values.

[0011] As a preferred embodiment of the radiation-resistant and solvent-resistant polycarbonate composition of the present invention, the polybutylene terephthalate has a melt mass flow rate of 22 g / 10 min to 35 g / 10 min at 250°C and 2.16 kg, preferably 26 g / 10 min to 32 g / 10 min. For example, but not limited to, it can be 22 g / 10 min, 23 g / 10 min, 24 g / 10 min, 25 g / 10 min, 26 g / 10 min, 27 g / 10 min, 28 g / 10 min, 29 g / 10 min, 30 g / 10 min, 31 g / 10 min, 32 g / 10 min, 33 g / 10 min, 34 g / 10 min or 35 g / 10 min, or within the range of any two of the above values.

[0012] In a preferred embodiment of the radiation-resistant and solvent-resistant polycarbonate composition of the present invention, the mass ratio of polybutylene terephthalate to triazine ultraviolet absorber is 0.3:1 to 3.5:1, for example, but not limited to 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1. The mass ratio of polybutylene terephthalate (PET) to triazine UV absorber within the above ranges can better achieve synergistic migration and surface enrichment, promoting the uniform dispersion of triazine UV absorbers within the PET film network, thereby better shielding and absorbing most incident UV radiation and blocking solvent penetration. This results in the best possible shielding and absorption of most incident UV radiation and preventing solvent penetration.

[0013] In some embodiments, the mass percentage of polybutylene terephthalate is from 0.02% to 1.2% based on the total mass of the radiation-resistant and solvent-resistant polycarbonate composition, for example, but not limited to 0.02%, 0.03%, 0.04%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, or 1.2%, or within the range of any two of the above values.

[0014] In some embodiments, the triazine UV absorber accounts for 0.02% to 1.2% of the total mass of the radiation-resistant and solvent-resistant polycarbonate composition, for example, but not limited to 0.02%, 0.03%, 0.04%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, or 1.2%, or falls within the range of any two of the above values.

[0015] In a preferred embodiment of the radiation-resistant and solvent-resistant polycarbonate composition of the present invention, the mass ratio of the phosphite stabilizer to the triazine UV absorber is 0.6:1 to 4:1, for example, but not limited to 0.6:1, 0.8:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, 3:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1, or 4:1, or within any range of two of the above values. A mass ratio of phosphite stabilizer to triazine UV absorber within the above range is more conducive to the triazine UV absorber located on the surface of the polycarbonate composition efficiently reducing UV penetration, thereby slowing down the consumption rate of the phosphite located internally, allowing the phosphite to function for a longer period. The synergistic effect of the two further improves the performance of the polycarbonate composition.

[0016] In a preferred embodiment of the radiation-resistant and solvent-resistant polycarbonate composition of the present invention, the number-average molecular weight of the polycarbonate is 20,000 to 50,000, for example, but not limited to 20,000, 22,000, 24,000, 26,000, 28,000, 30,000, 32,000, 34,000, 36,000, 38,000, 40,000, 42,000, 44,000, 46,000, 48,000, or 50,000, or within any range of two of the above values. The number-average molecular weight of the polycarbonate can be determined by gel permeation chromatography (GPC), using a cross-linked styrene-divinylbenzene column calibrated to a polycarbonate reference using a UV-VIS detector set to 254 nm. Samples can be prepared at a concentration of 1 mg / mL, and the sample is eluted at a flow rate of 1.0 mL / min.

[0017] As a preferred embodiment of the radiation-resistant and solvent-resistant polycarbonate composition of the present invention, the triazine-based ultraviolet absorber comprises a compound with the following chemical structural formula: R1 and R2 are each independently selected from hydrogen and phenyl.

[0018] As a preferred embodiment of the radiation-resistant and solvent-resistant polycarbonate composition of the present invention, the composition further includes processing aids, including at least one of lubricant and transesterification inhibitor.

[0019] In some embodiments, the processing aid in the radiation-resistant and solvent-resistant polycarbonate composition is 0.05 to 3 parts by weight, for example, but not limited to 0.05 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, or 3 parts, or within the range of any two of the above values.

[0020] In a second aspect, the present invention provides a method for preparing the above-mentioned radiation-resistant and solvent-resistant polycarbonate composition, comprising the following steps: mixing the components uniformly and melting and extruding to obtain the radiation-resistant and solvent-resistant polycarbonate composition.

[0021] Preferably, polybutylene terephthalate and triazine ultraviolet absorber are first mixed evenly and melt-extruded, and then melt-blended with the remaining components to obtain a radiation-resistant and solvent-resistant polycarbonate composition.

[0022] Optionally, the above preparation method can be carried out by melt extrusion using a twin-screw extruder, with a melt extrusion temperature of 250°C to 270°C and a screw speed of 600 rpm to 1000 rpm.

[0023] Thirdly, the present invention provides an application of the above-mentioned radiation-resistant and solvent-resistant polycarbonate composition in the preparation of robot parts.

[0024] In some embodiments, the robot component may be at least one of a quadruped robot or a humanoid robot; for example, the robot component may be the shell of a medical robot, a drug delivery system component, a camera protective cover and viewing window, etc.

[0025] Fourthly, the present invention provides a shell for a medical robot, which is made of the above-described radiation-resistant and solvent-resistant polycarbonate composition.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention combines polybutylene terephthalate (PET) with a triazine UV absorber at a specific melt flow rate. By controlling the melt flow rate of PET, it is uniformly dispersed in the continuous polycarbonate phase, while most of the triazine UV absorber is distributed in or around the PET phase. PET carries the triazine UV absorber to the surface of the polycarbonate composition, forming a protective film that effectively absorbs short-wave radiation and blocks solvent molecule penetration. Simultaneously, this film, combined with phosphite stabilizers mainly dispersed within the polycarbonate composition, further captures free radicals to inhibit photo-rearrangement and photo-oxidation reactions in polycarbonate, significantly mitigating its degradation and thus significantly improving the mechanical properties and solvent resistance of the polycarbonate composition. Attached Figure Description

[0027] Figure 1 This is a schematic structural diagram of the fixture used for solvent resistance testing of the radiation-resistant and solvent-resistant polycarbonate composition of the present invention. Detailed Implementation

[0028] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0029] Unless otherwise specified, all other materials, reagents, etc. used in the examples and comparative examples are commercially available.

[0030] 1. Raw materials and reagents 1) Polycarbonate (PC) PC-1, with a number-average molecular weight of 26,000, brand name PC 2100, manufactured by Wanhua Chemical; PC-2, with a number average molecular weight of 28,000, brand name PC 2070, manufactured by Wanhua Chemical; PC-3, with a number average molecular weight of 30,000, grade PC 7030PJ, is manufactured by Wanhua Chemical.

[0031] 2) Polybutylene terephthalate (PBT) PBT-1, melt flow rate of 30g / 10min, grade PBT GX121, manufacturer: China Petrochemical Corporation; PBT-2, melt flow rate of 26 g / 10 min, grade PBT TH6100, manufacturer: Xinjiang Lanshan Tunhe Polyester Co., Ltd. PBT-3, melt flow rate of 32 g / 10 min, grade PBT 1100A, manufacturer Nantong Xingchen Synthetic Materials Co., Ltd.; PBT-4, melt flow rate of 8 g / 10 min, grade PBT GL236, manufacturer: Sinopec Yizheng Chemical Fiber Co., Ltd.

[0032] 3) Ultraviolet absorbers Triazine UV absorber 1 is 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol, brand name UV-1577, manufacturer: Lianlong; Triazine UV absorber 2 is 2,4-bis(4-biphenyl)-6-(2,4-dihydroxy)phenyl-1,3,5-triazine, brand name TNUVIN 1600, manufacturer BASF; The benzotriazole UV absorber is 2-[2'-hydroxy-3',5'-bis(α,α-dimethylbenzyl)phenyl]benzotriazole, brand name DSUNSORB UV-234, manufacturer: Disheng.

[0033] 4) Stabilizer Phosphite stabilizer 1 is bis(2,4-diisopropylphenyl) pentaerythritol diphosphite, brand name Revonox 608, manufactured by Chi-Ti Corporation, Taiwan, China. Phosphite stabilizer 2 is tri-tert-butyl-p-hydroxyphenylpropane, brand name SONOX 168, manufacturer Mitutoyo; The hindered amine antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester, brand name SONOX 1076, manufactured by Mitutoyo.

[0034] 2. Preparation method of the radiation-resistant and solvent-resistant polycarbonate composition of the present invention According to the formula, polybutylene terephthalate and triazine UV absorber are first mixed evenly and melt-extruded, and then mixed evenly with the remaining components. The mixture is then added to a twin-screw extruder and melt-extruded and granulated at 250°C to 270°C to obtain a radiation-resistant and solvent-resistant polycarbonate composition. The screw speed of the twin-screw extruder is 800 rpm.

[0035] Table 1 shows the weight parts of each component in the radiation-resistant and solvent-resistant polycarbonate compositions of Examples 1 to 7. Table 2 shows the weight parts of each component in the radiation-resistant and solvent-resistant polycarbonate compositions of Examples 8 to 11. In Tables 1 and 2, “ / ” indicates no relevant parameters, “a” represents the mass ratio of PBT to triazine UV absorber, and “b” represents the mass ratio of phosphite stabilizer to triazine UV absorber.

[0036] Table 3 shows the weight parts of each component in the radiation-resistant and solvent-resistant polycarbonate compositions of each comparative example. In Table 3, " / " indicates that there are no relevant parameters.

[0037] 3. Performance Testing 1) Tensile strength test before and after irradiation: The irradiation-resistant and solvent-resistant polycarbonate compositions of each example and comparative example were injection molded into ASTM 1A type tensile test strips, and the test strips of each example or comparative example were randomly divided into two groups, A and B: Group A: Tensile test was performed directly according to standard ASTM D638 (tensile rate of 50 mm / min) to obtain the tensile strength a before irradiation. Group B: First subjected to UVC irradiation (irradiation wavelength 254nm, irradiation intensity 1mW / cm²). 2 The irradiation time was 1000h, and then a tensile test was performed according to the standard ASTM D638 to obtain the tensile strength b after irradiation. The tensile strength retention rate was calculated as b / a × 100%.

[0038] 2) Solvent resistance test after irradiation: The irradiation-resistant and solvent-resistant polycarbonate compositions from each example and comparative example were injection molded into US standard tensile test strips, and then subjected to UVC irradiation (irradiation wavelength of 254 nm, irradiation intensity of 1 mW / cm²). 2 Irradiation time is 1000h), and then it is placed on a fixture with a fixed strain of 1% (e.g. Figure 1 As shown in the figure, anhydrous ethanol was coated on the middle part of the sample, and the solvent resistance effect was evaluated by comparing the cracking time and crack size.

[0039] The rating criteria are shown in Table 4. The higher the rating, the better the solvent resistance. Within the same rating, the higher the score, the better the solvent resistance.

[0040] Table 4 Rating Criteria Table 5. Performance of the radiation-resistant and solvent-resistant polycarbonate compositions in each example and comparative example. According to the data in Table 5, the tensile strength of the radiation-resistant and solvent-resistant polycarbonate compositions in Examples 1 to 11 all reached 54.5 MPa or higher, and the tensile strength retention rate after UVC irradiation all reached 80% or higher. At the same time, the solvent resistance test scores were all greater than or equal to 80 points, indicating that the polycarbonate compositions of the present invention have both good mechanical properties and excellent solvent resistance after UVC radiation.

[0041] As can be seen from Example 1 and Comparative Example 1, when the melt flow rate of PBT is too low, although it has little effect on the initial tensile strength of the polycarbonate composition, it is difficult to effectively improve its radiation resistance, resulting in a low tensile strength retention rate after UVC radiation. As can be seen from Comparative Examples 2 to 5, replacing triazine UV absorbers with benzotriazole UV absorbers, replacing phosphite stabilizers with hindered amine antioxidants, or adding PBT or triazine UV absorbers alone, cannot improve the tensile strength retention rate and solvent resistance of the polycarbonate composition after UVC radiation. As can be seen from Comparative Examples 6 and 7, when the amount of polybutylene terephthalate or triazine UV absorbers added is too high, it will reduce the mechanical properties and solvent resistance of the polycarbonate composition after UVC radiation.

[0042] 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 radiation resistant, solvent resistant polycarbonate composition characterized in that, The composition comprises the following components by weight: polycarbonate 90-100 parts, polybutylene terephthalate 0.05-1 part, triazine ultraviolet absorber 0.05-1 part, and phosphite stabilizer 0.02-1 part; the polybutylene terephthalate has a melt mass flow rate of ≥12 g / 10 min at 250°C under a load of 2.16 kg.

2. The radiation resistant, solvent resistant polycarbonate composition of claim 1, wherein, The polybutylene terephthalate has a melt mass flow rate of 22 g / 10 min to 35 g / 10 min at 250°C under a load of 2.16 kg.

3. The radiation resistant, solvent resistant polycarbonate composition of claim 1, wherein, The mass ratio of the polybutylene terephthalate to the triazine ultraviolet absorber is 0.3:1 to 3.5:

1.

4. The radiation resistant, solvent resistant polycarbonate composition of claim 1, wherein, The mass ratio of the phosphite stabilizer to the triazine ultraviolet absorber is 0.6:1 to 4:

1.

5. The radiation and solvent resistant polycarbonate composition of claim 1, wherein, The polycarbonate has a number average molecular weight of 20,000 to 50,000.

6. The radiation and solvent resistant polycarbonate composition of claim 1, wherein, The triazine ultraviolet absorber comprises a compound represented by the following chemical structure: R1and R2are each independently selected from any one of hydrogen, phenyl.

7. The radiation and solvent resistant polycarbonate composition of claim 1, wherein, The processing aid in the components of the radiation-resistant and solvent-resistant polycarbonate composition comprises at least one of a lubricant and a transesterification inhibitor.

8. A process for the preparation of the radiation resistant, solvent resistant polycarbonate composition according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: The components are mixed uniformly, melted and extruded to obtain the radiation-resistant and solvent-resistant polycarbonate composition.

9. Use of the radiation-resistant and solvent-resistant polycarbonate composition according to any one of claims 1 to 7 in the preparation of a robot part.

10. A housing for a medical robot, characterized in that The robot part is made of the radiation-resistant and solvent-resistant polycarbonate composition according to any one of claims 1 to 7.

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