Optical resin and preparation method thereof

Abstract

The invention discloses an optical resin and a preparation method thereof, and belongs to the technical field of polyester synthesis and preparation. The preparation method comprises the following steps: sequentially carrying out esterification reaction and polycondensation reaction on a mixture containing terephthalic acid, alcohol and a catalyst to obtain the optical resin, the alcohol is selected from at least one of ethylene glycol, 1, 4-cyclohexanedimethanol and camphor alcohol; the catalyst is a titanium catalyst. According to the invention, by introducing camphor alcohol, the light transmittance and heat resistance of the copolyester are greatly improved. The mechanical property and processability of the optical resin are superior to those of a traditional PCTG material. In addition, the preparation method provided by the invention does not need to change a traditional PCTG production line during large-scale production, and the product performance is stable.

Description

Technical Field

[0001] The present application relates to an optical resin and a preparation method thereof, and belongs to the technical field of polyester synthesis and preparation. Background Art

[0002] PCTG is a highly transparent copolyester resin. It has high transparency, good mechanical properties, excellent low-temperature toughness, high tear resistance and good processing properties. It can be processed by traditional extrusion, injection molding, blow molding and blister molding methods, and is widely used in the sheet material, high-performance shrink film, bottle and profile markets; it has passed the US FDA food contact standards and can be used in food, cosmetic packaging and medical devices. In the field of medical devices, PCTG injection molding products include filters, ear tubes, tube connectors, pump clamps, indwelling needles and dialysis equipment. Although the CHDM structural unit is introduced into PCTG, it does not essentially improve the rigidity of the molecular chain, resulting in the glass transition temperature (T g ) is still low, and it cannot withstand hot water cleaning and pasteurization, which increases the risk of bacterial and microbial growth during reuse. Moreover, during clinical use, it is prone to cracking and lacks transparency, which seriously affects its clinical effectiveness. Summary of the Invention

[0003] In order to solve the above-mentioned technical problems existing in the prior art of PCTG materials, the present application proposes a technical solution for the preparation of an optical resin, in which polyethylene terephthalate glycol-1,4-cyclohexanedimethanol copolyester (PCTG) is modified with camphor alcohol. The transmittance, haze, heat resistance, and impact resistance of the obtained modified copolyester are greatly improved. At the same time, it has excellent optical, mechanical properties, biosafety, and good processability.

[0004] This application adopts the following technical solutions:

[0005] According to a first aspect of the present application, a method for preparing an optical resin is provided, comprising the following steps:

[0006] subjecting a mixture containing terephthalic acid, alcohol, and a catalyst to esterification reaction and polycondensation reaction in sequence to obtain the optical resin;

[0007] The alcohol is selected from at least one of ethylene glycol, 1,4-cyclohexanedimethanol, and camphor alcohol;

[0008] The catalyst is a titanium-based catalyst.

[0009] Camphorol, a natural compound extracted from the camphor tree, possesses a distinctive odor and certain biological activities, such as mosquito repellent and antibacterial properties. Its natural origin aligns with current trends in environmental protection and sustainable development. Using camphorol in PCTG modification to create a medical-grade optical resin with high transparency and impact resistance significantly enhances PCTG's performance while imparting new functional properties, such as antibacterial and mosquito repellent properties, thereby expanding PCTG's application in a wider range of fields.

[0010] Optionally, the molar ratio of the alcohol to terephthalic acid is 1.2 to 1.7:1.

[0011] Optionally, the alcohol comprises the following components in molar parts:

[0012] 0-1 mol part of ethylene glycol;

[0013] 0 to 5 molar parts of 1,4-cyclohexanedimethanol;

[0014] 0.01 to 2 molar parts of camphor alcohol.

[0015] Optionally, the titanium-based catalyst includes defective nano-titanium dioxide.

[0016] The preparation method of defective nano-titanium dioxide in this application is not strictly limited, and those skilled in the art can prepare it according to existing technologies or purchase it as a commodity.

[0017] Optionally, the amount of the titanium-based catalyst used is 0.001‰ to 5‰ of the total mass of the terephthalic acid and alcohol.

[0018] Optionally, the esterification reaction conditions include: the reaction is carried out in an inert atmosphere, the reaction temperature is 180 to 245° C., and the reaction time is 0.5 to 6 hours.

[0019] Optionally, the esterification reaction is carried out under step-by-step temperature increase conditions.

[0020] Optionally, the inert atmosphere is selected from nitrogen and argon.

[0021] Optionally, the conditions for the polycondensation reaction include: the reaction is carried out under vacuum conditions, the reaction temperature is 180-270° C., and the reaction time is 0.5-8 h.

[0022] Optionally, the polycondensation reaction is carried out under step-by-step temperature increase conditions.

[0023] Optionally, the vacuum condition is: vacuum degree ≤ 200Pa.

[0024] According to a second aspect of the present application, an optical resin obtained by the above preparation method is provided, wherein the optical resin has at least one of the following performance characteristics:

[0025] The chromaticity b of the optical resin is ≤ 2.0;

[0026] The optical resin has a light transmittance of ≥92%;

[0027] The haze of the optical resin is ≤0.5;

[0028] The intrinsic viscosity of the optical resin is 0.60 to 1.5 dL / g;

[0029] The tensile strength of the optical resin is ≥50MPa;

[0030] The elongation at break of the optical resin is ≥50%;

[0031] The in vitro cytotoxicity of the optical resin after 72 hours of extraction with culture medium is ≤ Grade 1;

[0032] The hemolysis rate of the optical resin is ≤5%.

[0033] The beneficial effects of this application include:

[0034] The optical resin preparation method provided in this application utilizes camphor alcohol to modify PCTG materials, significantly improving the optical and mechanical properties of conventional PCTG optical resins. The use of highly active nano-defective titanium dioxide as a catalyst further enhances the optical properties of conventional PCTG optical resins. The resulting optical resin exhibits no biotoxicity. The mechanical properties and processability of the optical resin obtained in this application are superior to those of conventional PCTG materials. Furthermore, the preparation method provided in this application eliminates the need to modify conventional PCTG production lines for large-scale production, resulting in stable product performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the structural formula of the optical resin of this application.

[0036] Figure 2 This is a schematic diagram of the structural formula of the nano-defective TiO2 catalyst used in this application. DETAILED DESCRIPTION

[0037] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0038] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0039] Camphor alcohol was purchased from Beijing Inokai Technology Co., Ltd., and the nano-defective TiO2 catalyst was homemade.

[0040] Unless otherwise specified, conventional methods were used for testing, and the instrument settings were those recommended by the manufacturer.

[0041] The colorimeter (CS-826) used in the embodiments of the present application for measuring chromaticity, transmittance, and haze, and the Zhongwang Ubbelohde viscometer (IVS100) used for measuring intrinsic viscosity, all use the test method in the GB / T 14190-2008 standard. The Instron electronic universal material testing machine (Instron-1121) used for measuring tensile strength and elongation at break was used to perform tensile tests at 25°C according to ASTM D638 requirements. The tensile speed was 5 mm / min. A dumbbell-shaped sample with a width of 3.18 mm and a thickness of 3.2 mm was prepared by injection molding using an injection molding machine, and the tensile strength and elongation at break of the sample were obtained.

[0042] Example 1

[0043] 0.1 mol of terephthalic acid, 0.07 mol of ethylene glycol, 0.035 mol of 1,4-cyclohexanedimethanol and 0.035 mol of camphor alcohol were used as raw materials (the molar ratio of alcohol to alcohol was 1.4), and 0.005‰ of nano-defective TiO2 catalyst was added and mixed evenly. Esterification reaction was carried out under nitrogen protection with gradient temperature increase at 200-240°C for 3.5h, and polycondensation reaction was stopped at 260°C for 2h. The obtained product polyester S1 was subjected to viscosity, optical, mechanical and biological tests. The results are shown in Table 1.

[0044] The structural diagram of the product polyester is as follows Figure 1 shown.

[0045] Example 2

[0046] 0.1 mol of terephthalic acid, 0.08 mol of ethylene glycol, 0.04 mol of 1,4-cyclohexanedimethanol and 0.04 mol of camphor alcohol were used as raw materials (the molar ratio of alcohol to acid was 1.6), and 0.005‰ of nano-defective TiO2 catalyst was added and mixed evenly. Esterification reaction was carried out under nitrogen protection with gradient temperature increase at 200-240°C for 3.5h, and polycondensation reaction was stopped at 260°C for 2h. The obtained product polyester S2 was subjected to viscosity, optical, mechanical and biological tests. The results are shown in Table 1.

[0047] Example 3

[0048] 0.1 mol of terephthalic acid, 0.07 mol of ethylene glycol, 0.035 mol of 1,4-cyclohexanedimethanol and 0.035 mol of camphor alcohol were used as raw materials (the molar ratio of alcohol to acid was 1.4), and 0.001‰ of nano-defective TiO2 catalyst was added and mixed evenly. The esterification reaction was carried out under nitrogen protection, with a gradient temperature increase of 200-240°C for esterification for 3.5h, and the polycondensation reaction was stopped at 260°C for 2h. The obtained product polyester S3 was subjected to viscosity, optical, mechanical and biological tests. The results are shown in Table 1.

[0049] Example 4

[0050] 0.1 mol of terephthalic acid, 0.02 mol of ethylene glycol, 0.1 mol of 1,4-cyclohexanedimethanol and 0.04 mol of camphor alcohol were used as raw materials (the molar ratio of alcohol to alcohol was 1.6), and 0.005‰ of nano-defective TiO2 catalyst was added and mixed evenly. Esterification reaction was carried out under nitrogen protection with gradient temperature increase at 180-240°C for 3.0 h, and polycondensation reaction was stopped at 240-260°C for 2 h. The obtained product polyester S4 was subjected to intrinsic viscosity, optical, mechanical and biological tests. The results are shown in Table 1.

[0051] Example 5

[0052] 0.1 mol of terephthalic acid, 0.04 mol of ethylene glycol and 0.08 mol of camphor alcohol were used as raw materials (the molar ratio of alcohol to alcohol was 1.2), and 0.005‰ of nano-defective TiO2 catalyst was added and mixed evenly. Esterification reaction was carried out under nitrogen protection with gradient temperature increase at 180-245°C for 3.0 h, and polycondensation reaction was stopped at 240-265°C for 2 h. The obtained product polyester S5 was subjected to viscosity, optical, mechanical and biological tests. The results are shown in Table 1.

[0053] Example 6

[0054] 0.1 mol of terephthalic acid, 0.1 mol of 1,4-cyclohexanedimethanol and 0.07 mol of camphor alcohol were used as raw materials (the molar ratio of alcohol to alcohol was 1.7), and 0.005‰ of nano-defective TiO2 catalyst was added and mixed evenly. Esterification reaction was carried out under nitrogen protection with gradient temperature increase at 180-235°C for 3.0 h, and polycondensation reaction was stopped at 240-245°C for 2 h. The obtained product polyester S6 was subjected to viscosity, optical, mechanical and biological tests. The results are shown in Table 1.

[0055] Comparative Example 1

[0056] 0.1 mol of terephthalic acid, 0.07 mol of ethylene glycol and 0.07 mol of 1,4-cyclohexanedimethanol were used as raw materials (the molar ratio of alcohol to acid was 1.4), and 0.005‰ of the total mass of the acid and alcohol feed was added as a nano-defective TiO2 catalyst. The mixture was mixed evenly, and the esterification reaction was carried out under nitrogen protection. The temperature was increased gradually, and the esterification reaction was carried out at 200-240°C for 3.5 hours. The condensation reaction was stopped at 260°C for 2 hours. The obtained product polyester D1 was subjected to viscosity, optical, mechanical and biological tests. The results are shown in Table 1.

[0057] Comparative Example 2

[0058] 0.1 mol of terephthalic acid, 0.07 mol of ethylene glycol and 0.07 mol of 1,4-cyclohexanedimethanol were used as raw materials (the molar ratio of alcohol to acid was 1.4), and 0.005‰ of tetrabutyl titanate catalyst was added to the total mass of the acid and alcohol feed. The mixture was evenly mixed, and the esterification reaction was carried out under nitrogen protection. The temperature was increased gradually, and the esterification reaction was carried out at 200-240°C for 3.5 hours. The polycondensation reaction was stopped at 260°C for 2 hours. The obtained product polyester D2 was subjected to viscosity, optical, mechanical and biological tests. The results are shown in Table 1.

[0059] Table 1

[0060]

[0061] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing an optical resin, characterized in that: The steps include: subjecting a mixture containing terephthalic acid, alcohol, and a catalyst to esterification reaction and polycondensation reaction in sequence to obtain the optical resin; The alcohol is selected from at least one of ethylene glycol, 1,4-cyclohexanedimethanol, and camphor alcohol; The catalyst is a titanium-based catalyst.

2. The preparation method according to claim 1, characterized in that The molar ratio of the alcohol to terephthalic acid is 1.2-1.7:

1.

3. The preparation method according to claim 1, characterized in that The alcohol comprises the following components in molar parts: 0-1 mol part of ethylene glycol; 0 to 5 molar parts of 1,4-cyclohexanedimethanol; 0.01 to 2 molar parts of camphor alcohol.

4. The preparation method according to claim 1, characterized in that The titanium-based catalyst includes defective nano-titanium dioxide.

5. The preparation method according to claim 1, characterized in that The amount of the titanium catalyst used is 0.001‰ to 5‰ of the total mass of the terephthalic acid and alcohol.

6. The preparation method according to claim 1, characterized in that The conditions of the esterification reaction include: the reaction is carried out in an inert atmosphere, the reaction temperature is 180-245° C., and the reaction time is 0.5-6 hours.

7. The preparation method according to claim 6, characterized in that The inert atmosphere is selected from nitrogen and argon.

8. The preparation method according to claim 1, characterized in that The conditions of the polycondensation reaction include: the reaction is carried out under vacuum conditions, the reaction temperature is 180-270° C., and the reaction time is 0.5-8 hours.

9. The preparation method according to claim 8, characterized in that The vacuum condition is: vacuum degree ≤ 200Pa.

10. The optical resin obtained by the preparation method according to any one of claims 1 to 9, characterized in that: The optical resin has at least one of the following performance characteristics: The chromaticity b of the optical resin is ≤ 2.0; The optical resin has a light transmittance of ≥92%; The haze of the optical resin is ≤0.5; The intrinsic viscosity of the optical resin is 0.60 to 1.5 dL / g; The tensile strength of the optical resin is ≥50MPa; The elongation at break of the optical resin is ≥50%.

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