CN114539701B

CN114539701B - High-impact-resistance and high-heat-resistance transparent optical material and preparation method thereof

Info

Publication number: CN114539701B
Application number: CN202210338570.6A
Authority: CN
Inventors: 胡树; 李东平; 李清平
Original assignee: Dongguan Tarry Electronic Co ltd
Current assignee: Dongguan Tarry Electronic Co ltd
Priority date: 2022-04-01
Filing date: 2022-04-01
Publication date: 2023-04-07
Anticipated expiration: 2042-04-01
Also published as: CN114539701A

Abstract

The application belongs to the technical field of modified high polymer materials, and provides a high-impact-resistance and high-heat-resistance transparent optical material and a preparation method thereof, wherein the melt blending preparation raw materials comprise: 60-80 parts of PMMA resin, 15-26 parts of PC resin, 4.5-12 parts of compatibilizer and 0.5-2 parts of lubricant; the compatibilizer is polymethyl methacrylate-polyarylate block copolymer. The optical material provided by the embodiment of the application has excellent optical characteristics and scratch resistance, good impact resistance, thermal stability and flame retardance, and has good toughness even if the optical material is not subjected to stretching orientation. The preparation of the optical material comprises the steps of pretreatment, mixing, melting and the like of raw materials, and the method has the advantages of cheap equipment, simple process, low energy consumption and easy realization of industrialization. The high-impact-resistance and high-heat-resistance transparent optical material has the light transmittance of more than or equal to 90% at 3mm and the haze of less than or equal to 1.0% at 3 mm.

Description

High-impact-resistance and high-heat-resistance transparent optical material and preparation method thereof

Technical Field

The application belongs to the technical field of modified high polymer materials, and particularly relates to a high-impact-resistance and high-heat-resistance transparent optical material and a preparation method thereof.

Background

Among many polymer materials, polymethyl methacrylate (PMMA) is widely used in the fields of optics, electronics, etc. due to its excellent optical properties and comprehensive mechanical properties. However, PMMA has the defects of small refractive index, poor impact resistance and the like, so that the application of PMMA in a specific field is limited. Polycarbonate (PC) has excellent properties such as good transparency, good heat resistance, and good toughness, but it has poor fluidity, is difficult to process, has low surface hardness, and has poor abrasion resistance (usually, surface treatment is required). Therefore, PMMA is an ideal hardening modification material of the PC optical material, and PC is a potential ideal heat-resistant toughening modification material of the PMMA optical material. Therefore, the PMMA/PC blend optical material not only has the basic characteristics of PMMA, but also has good heat-resistant stability and toughness (flexing resistance), and has wide application prospect.

In industrial production application, the preparation method of PMMA/PC blend material is mainly divided into a solution blending method and a melt blending method. Although PMMA and PC both contain ester groups, the solubility parameter, δ, of PC _PC About 20.3 (J/cm) ³ ) ^1/2 Solubility parameter delta of PMMA _PMMA About 18.8 (J/cm) ³ ) ^1/2 A difference of about 1.5, so that the two are partially compatible systems, resulting in polymerizationIn the microstructure of the blend, the interface tension between PMMA phase and PC phase is large, the interface compatibility is poor, and the two phases can be separated. On the other hand, the refractive index of PC is about 1.582, that of PMMA is 1.492, and if the compatibility of two phases is poor, light scattering inevitably occurs when light passes through the blend, the surface has pearl appearance, and the haze is large.

In the chinese patent document No. 202011371198.6, a PMMA/PC blend transparent optical material having excellent optical characteristics and thermal stability, and low haze and yellowness is prepared by a solution blending method, and does not undergo phase separation even in a high temperature environment. Although the optical film prepared by the solution method has excellent optical performance, the solvent recovery cost is high, the processing and forming equipment is expensive, the process is relatively complex, the dimensional stability is relatively poor, the production efficiency is low, and the industrialization is not facilitated. And relatively, the melt blending method has simple production equipment and process and high production efficiency, and is more suitable for industrial production of PMMA and PC blend materials. For example, in the Chinese patent document with the application number of 201410282352.0, a ternary graft copolymer (MMA-g-St/MAH) of MMA monomer, styrene and maleic anhydride is used as a main modifier, and is extruded and granulated in a double-screw extruder to prepare a PC/PMMA blend with good mechanical properties. However, the PC/PMMA blend is not a transparent material because the molecular level dispersion is not achieved, and the application is influenced.

Disclosure of Invention

In order to solve the above technical problems in the prior art, the present invention aims to provide a high impact resistant, high heat resistant transparent optical material and a preparation method thereof, wherein the optical material is a PC/PMMA blend material, has excellent optical characteristics, good impact resistance and thermal stability, and is easy to realize industrialization.

The invention provides a high-impact-resistance and high-heat-resistance transparent optical material, which is prepared by melt blending of the following raw materials: 60-80 parts of PMMA resin, 15-26 parts of PC resin, 4.5-12 parts of compatibilizer and 0.5-2 parts of lubricant; the compatibilizer is polymethyl methacrylate-polyarylate block copolymer; the lubricant has carbon atom numberC ₁₅ ～C ₃₈ A liquid saturated alkane mixture of (2).

Preferably, the raw materials for preparing the high-impact-resistant and high-heat-resistant transparent optical material comprise 70 to 75 parts by weight of PMMA resin, 17 to 20 parts by weight of PC resin, 6.5 to 9 parts by weight of compatibilizer and 1 to 1.5 parts by weight of lubricant.

The PMMA resin comprises one or more of isotactic polymethyl methacrylate, syndiotactic polymethyl methacrylate and atactic polymethyl methacrylate. Preferably, the PMMA resin is syndiotactic polymethyl methacrylate.

For polymers with pseudochiral carbon, polymers with all repeating structural stereo configurations being the same are called isotactic polymers, and polymers with any adjacent repeating structural unit having the opposite configuration are called syndiotactic polymers. Wherein, the random polymethyl methacrylate is polymethyl methacrylate with irregular arrangement of substituents on the molecular chain of the central axis.

In the embodiment of the invention, the 3mm light transmittance of the PMMA resin is more than or equal to 92%, the 3mm haze is less than or equal to 0.5%, and the optical performance is excellent. Specifically, the PMMA resin: the light transmittance of 3mm is more than or equal to 92 percent, the haze of 3mm is less than or equal to 0.5 percent, the melt index is 1.0g/10 min-15 g/10min (230 ℃,3.8 kg), and the product can be sold in the market. Preferably, the 3mm light transmittance of the PMMA resin is more than or equal to 93 percent, the 3mm haze is less than or equal to 0.3 percent, and the melt index is 2.4g/10 min-10 g/10min (230 ℃,3.8 kg).

According to the invention, the PC resin is used for carrying out blending modification on the PMMA resin, so that the heat resistance and the impact resistance of the blend are improved; the PC resin can be used in 18 parts, 19 parts, 20 parts and the like. Preferably, the PC resin is an aromatic polycarbonate and/or an aromatic copolycarbonate. More preferably, the PC resin is an aromatic copolycarbonate.

In the embodiment of the invention, the aromatic copolycarbonate is a binary copolymer of 2,2-bis (4-hydroxyphenyl) propane structural unit and a specific structural unit, the mass fraction of the 2,2-bis (4-hydroxyphenyl) propane structural unit can be 70% to 95%, and the mass fraction of the specific structural unit is 5% to 30%. Preferably, in the aromatic copolycarbonate, the mass fraction of 2,2-bis (4-hydroxyphenyl) propane structural unit is 80 to 90%, and the mass fraction of the specific structural unit is 10 to 20%.

Wherein the specific structural units are mainly aromatic group diphenol structural units, specifically comprising 4,4-biphenol (structural formula shown below), 3,3', 5,5' -tetra-tert-butyl-2,2 ' -biphenol, 5,5',6,6' -tetramethyl-3,3 ' -di-tert-butyl-1,1 ' -biphenyl-2,2 ' -diol, S-1,1' -bi-2-naphthol, R-1,1' -bi-2-naphthol, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 9,9-bis (4-hydroxyphenyl) fluorene, 4,4' - (1-phenylethyl) bisphenol, 3625-dihydroxydiphenylsulfone, 1-bis (4-hydroxyphenyl) -5427-dichlorodiphenylethylene-8626-dichlorodiphenylene, and diisopropylphenylene-863883-trimethylhexylene-7427-bis (4-hydroxyphenyl) 8627-trimethylhexylene-8627-bis (3-phenylidene) 8627-bis (3-dichloroethylene-3825-dichloroethylene-8626, 3-bis (3-trimethylhexylene-7427-bis (diisopropylbenzene).

And 2,2-bis (4-hydroxyphenyl) propane (also known as bisphenol A) has the following structural formula;

4,4-biphenol; />

Bisphenol A.

Preferably, the PC resin has a melt index of 6 to 33g/10min at 330 ℃ under 1.2 kg. In the specific embodiment of the invention, the PC resin has the light transmittance of more than or equal to 87% at 3mm, the haze of less than or equal to 1.0% at 3mm and the melt index of 6g/10 min-33 g/10min (330 ℃,1.2 kg). Preferably, the PC resin: the light transmittance of 3mm is more than or equal to 88 percent, the haze of 3mm is less than or equal to 0.3 percent, and the melt index is 12g/10 min-25 g/10min (330 ℃,1.2 kg).

Because the addition of the PC resin easily causes the reduction of the rigidity (tensile strength) of the PMMA resin, and the PMMA and the PC are partial compatible systems, and the ideal high-impact-resistance high-heat-resistance transparent optical material cannot be obtained by directly blending.

The invention mainly adopts 4.5 to 12 weight parts of compatibilizer, preferably 6.5 to 9 weight parts; the compatibilizer is a polymethyl methacrylate (PMMA) -Polyarylate (PAR) block copolymer and comprises a methyl methacrylate structure, aromatic ester groups and the like. The compatibilizer added in the invention is a PMMA-PAR block copolymer which has natural compatibility with PMMA resin which is a main material. In the melt blending process, when the temperature is over 240 ℃, even if no catalyst is added, ester exchange reaction can occur between aromatic ester groups of the PAR component and carbonate groups of PC, and a PC-PAR-PMMA graft copolymer is formed at a PMMA/PC two-phase interface; the graft copolymer can play a role in compatibilization between PMMA and PC, so that the compatibility between PMMA and PC is effectively improved, and the optical material with high transparency, high light transmittance and low haze is obtained.

The PAR component in the compatibilizer disclosed by the embodiment of the invention has the advantages of high refractive index, good rigidity and wear resistance, excellent high temperature resistance and weather resistance (ultraviolet resistance) and self-extinguishing property. The PC resin can better improve the reduction of rigidity, weather resistance and wear resistance of the optical material caused by the introduction of the PC resin, further improve the heat resistance of the optical material and improve the flame retardance of the optical material. In addition, the preferable PMMA-PAR segmented copolymer main chain adopted by the compatibilizer contains cyano, so that the oil resistance of the optical material can be effectively improved.

Specifically, the polymethyl methacrylate (PMMA) -Polyarylate (PAR) block copolymer preferably has a cyano group in the main chain, and the cyano group content is 0.1 to 0.65wt% based on the mass of the block polymer.

In a particular embodiment of the invention, the compatibilizer formula preferably comprises: a main chain first structure shown in formula 1 and a main chain second structure shown in formula 2. In the formula 1, a benzene ring structure connecting two ester groups is provided, and the benzene ring structure can be meta-position or para-position, and n is an integer; m in the formula 2 is an integer, and n is less than m.

The structure described in formula 1 is specifically as follows:

in an embodiment of the invention, the compatibilizer is a Polymethylmethacrylate (PMMA) -Polyarylate (PAR) block copolymer having a number average molecular weight Mn =8000 to 50000 g/mol. The number average molecular weight Mn of the polymethyl methacrylate-polyarylate block copolymer is =10000 g/mol-50000 g/mol, the mass fraction of PMMA is preferably 60% -80%, and the mass fraction of PAR is 20% -40%. Preferably, the Polymethylmethacrylate (PMMA) -Polyarylate (PAR) block copolymer: the number average molecular weight Mn is =20000 g/mol-40000 g/mol, the mass fraction of PMMA is 70% -75%, and the mass fraction of PAR is 25% -75%; the cyano group of the polymethyl methacrylate-polyarylate block copolymer compatibilizer is 0.1-0.65 wt%.

The compatibilizer specifically adopted in the embodiment of the invention can be a commercially available product or can be prepared by self; the following procedure for the preparation of the compatibilizer is exemplified:

(1) Preparation of hydroxyl-terminated polyphenyl ester (hydroxyl-terminated PAR)

Excessive bisphenol A (BPA) and p-phthaloyl chloride or m-phthaloyl chloride are subjected to polycondensation reaction in a chloroform solvent, and then a methanol precipitator is used for precipitating, washing and drying the polymer to obtain the hydroxyl-terminated PAR. Reference is made to the content of the paper published in the journal of Polymer, p.J.A.Brandt, 1990, on page 180.

(2) Preparation of 4,4' -azobiscyanopentane acyl chloride (ACPC)

In a 100mL three-necked flask equipped with a thermometer, a magnetic stirring device and a drying tube, 3.0g of 4,4' -azobiscyanoglutaric acid (ACPA) and 30mL of benzene were charged, and under ice-water bath conditions, 6.0g of PCl was added in portions ₅ (ii) a Stirred for 2h and then reacted at room temperature for 24h. Filtered and dried in vacuo to give a yellow solid. By usingSoaking and washing with mixed solution of anhydrous diethyl ether and n-hexane (volume ratio of 1: 3) for 2 times, adding dichloromethane to dissolve, and recrystallizing with n-hexane to obtain light yellow solid.

Or another technical route is adopted: ACPA was subjected to acid chlorination, and specific synthesis methods were described in A.Ueda et al, 1976, kobunshi Ronbunshu, page 131.

(3) Preparation of macromolecular azo initiator

The macromolecular azobenzene initiator is prepared by taking a molecular mixture of hydroxyl-terminated PAR, ACPC and the like as a raw material. The reference Jin Lijiang is equal to part 1.3 of a paper 4,4' -azobis (4-cyanopentanoic acid) polyethylene glycol ester macromolecular radical initiator synthesized and characterized in journal of polymer materials science and engineering published in 2007.

(4) Preparation of PMMA-PAR Block copolymer

0.150mol of MMA and a certain amount of macroazo initiator are added into a 1L three-necked flask equipped with a thermometer, a magnetic stirring device and a drying tube, then 600ml of chloroform is added, and the mixture is stirred for 24 hours at the temperature of 60 ℃ under the protection of nitrogen gas to carry out free radical polymerization. The reaction mixture was added to 10 times methanol, and the precipitated polymer was filtered and dried under reduced pressure to obtain a compatibilizer PMMA-PAR block copolymer.

In order to ensure the processability, the optical characteristics and the like, 0.5 to 2 parts by weight of lubricant is also adopted; the preparation raw material preferably comprises 1-1.5 parts of lubricant.

In an embodiment of the invention, the lubricant is C ₁₅ ～C ₃₈ The liquid saturated alkane mixture of (2) can be a commercially available product. Preferably, the lubricant has carbon atom number C ₂₀ ～C ₃₀ A mixture of saturated alkanes. The lubricant in the embodiment of the invention adopts an inert saturated alkane mixture (cycloalkane and straight-chain alkane) with low molecular weight and low boiling point, and in the PMMA/PC blend processing process, a part of the lubricant can permeate into a molecular chain to play a role in internal lubrication, improve the fluidity of PC resin and reduce the processing temperature of the blend. Due to the lower boiling point, another part will migrate to the resin surface, reducing the treesThe friction of the fat with the equipment generates heat and abrasion, and due to the low molecular weight, it is completely volatilized at the extruder die, leaving no residue in the blend, making the blend smooth on its surface.

In an embodiment of the invention, the liquid saturated alkane mixture comprises 60 to 80wt% of cycloalkanes and 20 to 40wt% of linear alkanes. Preferably, the liquid saturated alkane mixture comprises: 65 to 75 mass percent of naphthenic hydrocarbon and 25 to 35 mass percent of straight-chain alkane.

In the embodiment of the invention, the kinematic viscosity of the liquid saturated alkane mixture at 40 ℃ is 50-200 mm ² S, a number-average molecular weight Mn of 200g/mol to 500g/mol. It is further preferred that the alkane mixture has a kinematic viscosity (40 ℃) of 100mm ² /s～150mm ² (s) a number-average molecular weight Mn of 250 to 300g/mol.

In the embodiment of the invention, the high-impact-resistance and high-heat-resistance transparent optical material has the light transmittance of more than or equal to 90% at 3mm and the haze of less than or equal to 1.0% at 3 mm; preferably a yellowness index of < 1 and/or a certain flame retardancy.

The present invention provides a method for preparing a high impact, high heat resistant transparent optical material as described hereinbefore, comprising the steps of: drying the raw materials respectively, mixing the raw materials according to the weight ratio, and performing melt extrusion at the temperature of 210-270 ℃ to obtain the high-impact-resistance high-heat-resistance transparent optical material.

In the embodiment of the invention, raw material pretreatment is firstly carried out, and preferably:

pretreatment of PMMA resin: drying for 4-8 h at 90-110 ℃ in a blast oven for later use.

Pretreatment of PC resin: drying for 4-8 h in a blast oven at 100-130 ℃ for later use.

Pretreatment of the compatibilizer: drying for 4-8 h in a blast oven at 100-120 ℃ for later use.

The lubricant is not easy to absorb water, is sealed in time after being used, is shaded, dried and stored, and does not need special treatment before use.

Then, in the embodiment of the invention, the pretreated PMMA resin, PC resin, compatibilizer and lubricant are weighed according to the weight ratio of (60-80) to (15-26) to (4.5-12) to (0.5-2), and are added into a high-speed mixer, and are preferably mixed for 5-10 min at the normal temperature at the speed of 200-800 r/min, so that the raw materials are fully mixed for later use.

In the embodiment of the invention, the fully mixed raw materials are added into a hopper of a double-screw extruder, and the high-impact-resistance and high-heat-resistance transparent optical material is obtained through extrusion, melting and granulation. Wherein the melt extrusion temperature range is preferably 210 to 270 ℃. Specifically, the temperature of a first zone of the double-screw extruder is 210-230 ℃, the temperature of a second zone is 220-240 ℃, the temperature of a third zone is 225-245 ℃, the temperature of a fourth zone is 230-250 ℃, the temperature of a fifth zone is 235-255 ℃, the temperature of a sixth zone is 240-260 ℃, the temperature of a seventh zone is 245-265 ℃, and the temperature of a machine head is 250-270 ℃; the screw rotation speed can be 80-300 rpm.

Compared with the prior art, the transparent optical material can be obtained by melting and blending 60-80 parts of PMMA resin, 15-26 parts of PC resin, 4.5-12 parts of compatibilizer (PMMA-PAR block copolymer) and 0.5-2 parts of lubricant which are used as preparation raw materials. The components and the raw materials of the invention act together, thus simply and efficiently improving the heat resistance and the impact resistance of the PMMA/PC blend, and ensuring the characteristics of high transparency, high light transmittance, low haze and the like.

Preferably, the raw materials for preparing the high-impact-resistant and high-heat-resistant transparent optical material comprise 70-75 parts by weight of PMMA resin, 17-20 parts by weight of PC resin, 6.5-9 parts by weight of compatibilizer and 1-1.5 parts by weight of lubricant. The PMMA resin is isotactic polymethyl methacrylate and/or syndiotactic polymethyl methacrylate and/or atactic polymethyl methacrylate; the PC resin is aromatic polycarbonate and/or aromatic copolycarbonate; the compatibilizer is a polymethyl methacrylate (PMMA) -Polyarylate (PAR) block copolymer; the lubricant is C ₁₅ ～C ₃₈ A mixture of saturated alkanes. The high-impact-resistance high-heat-resistance transparent optical material provided by the embodiment of the application has excellent optical characteristics and scratch resistance, good impact resistance, thermal stability and flame retardance, and has good toughness even if the material is not subjected to stretching orientation. The high-impact-resistance and high-heat-resistance transparent optical materialThe preparation method of the material comprises the steps of pretreatment of raw materials, mixing and melting preparation of the raw materials and the like, and the method has the advantages of cheap equipment, simple process, low energy consumption and easy realization of industrialization.

Detailed Description

The technical solutions in the embodiments of the present application are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the embodiment of the present invention, the experimental and testing apparatus and the performance testing method adopted by the present invention are as follows:

(I) Experimental and testing apparatus

(1) Plastic injection molding machine: force group, high speed injection molding machine EFFECTA-S.

(2) Electronic tensile machine: nippon Shimadzu corporation, tensile tester AGS-X10KN.

(3) Cantilever beam notch impact tester: touch screen cantilever beam impact tester MK-1843, mike instruments and Equipment, inc. of Dongguan.

(4) A pencil hardness tester: shenzhen Shenyu instruments and equipments, full-automatic electric pencil hardness tester.

(5) Microcard softening temperature tester: jiangsu Zhengruibang electronic technology ltd, thermal deformation temperature tester, model ZB-909.

(6) Spectrophotometry measuring instrument: hunterLab corporation, usa, spectrophotometric measuring instrument Vista.

(7) And (3) air-blast drying oven: shanghai-Heng scientific instruments Co., ltd., forced air oven 9240A.

(8) Ultraviolet light weather resistance test box: kailan detection Instrument factory, kailan, thickness street, dongguan city, ultraviolet light weather resistance test box OM-847.

(9) Oxygen index tester: katel instruments, inc., suzhou, limited oxygen index Analyzer K-R2406S.

(10) UL94 burn test machine: shanghai additive industries, inc., UL94 flame tester.

(II) characterization of Properties of high impact, high Heat resistant transparent optical Material

The high-impact-resistance and high-heat-resistance transparent optical material is injected into specified sample bars of various standards by using a plastic injection molding machine, and the following tests are respectively carried out to characterize the performance:

physical and mechanical properties:

(1) Tensile strength and elongation at break

The Tensile strength and elongation at break of the specimens were measured by using an electronic Tensile machine with reference to ASTM D638-2014 Standard Test Method for Tensile Properties of Plastics. Type I specimen, test speed 500mm/min.

(2) Impact performance

The Impact properties of the specimens were measured using a notched Izod Impact tester, in accordance with ASTM D256-2018 Standard Test Methods for Determining the Izod Impact Resistance of Plastics. The sample type is II type, A type gap, the thickness of the sample strip is 3.0mm +/-0.2 mm, and the test temperature is 23 +/-0.5 ℃.

(3) Surface hardness

The scratch resistance of the sample is measured using a pencil Hardness tester, according to the ASTM D3363-2005 Standard Test Method for Film Hardness by Penciltest. The specimens had a thickness of 3.2mm, a scratch speed of 1cm/s and a load of 1kg.

Thermal properties:

(4) Softening temperature of microcard

Vicat softening temperature (B50): the measurement was carried out in accordance with ASTM D1525-2017Standard Test Method for visual software testing of Plastics, the weight was 10. + -. 0.2N, the Temperature rise rate was 50. + -. 5 ℃/h, and the Vicat Softening Temperature was recorded as the Temperature at which the needle was inserted into the specimen at 1. + -. 0.01 mm.

Optical properties:

(5) Light transmittance and haze

The measurement of the light transmittance and haze of the sample was carried out at a wavelength of 550nm using a spectrophotometric measuring instrument with reference to ASTM D1003-2013 transparent plastic light transmittance and haze. The specimen thickness was 3.0mm.

(6) Weathering resistance aging test

And (3) placing the sample in an ultraviolet light weather-proof test box, performing light ageing treatment for 24 hours, and taking out. The yellowness index YI values of the samples before and after the light treatment were determined using a spectrophotometric measuring instrument. The lower the YI value, the better the weather resistance.

Flame retardant property:

(7) Limiting oxygen index test

And (4) carrying out limit oxygen index test by using a limit oxygen index analyzer according to ASTM D2863-2013.

(8) Test of Combustion Performance

The combustion test was carried out using a UL94 combustion tester by the horizontal method in accordance with GB/T2408-1996 test methods for Plastic Combustion Performance horizontal and vertical methods.

In order to more clearly explain the process flow of the high impact resistant, high heat resistant transparent optical material and the method for preparing the same provided by the present application, the following examples are provided for corresponding explanation. In the following examples, the starting materials are mainly commercial products.

Wherein the compatibilizer is obtained according to the preparation steps of the PMMA-PAR block copolymer and comprises the following steps: preparing hydroxyl-terminated polyphenyl ester (hydroxyl-terminated PAR); preparation of 4,4' -azobiscyanopentane acyl chloride (ACPC); preparing a macromolecular azo initiator, and preparing a PMMA-PAR block copolymer; the structural formula is as follows, wherein the mass fraction of PMMA is 70-75%, and the mass fraction of PAR is 25-75%; the polymethyl methacrylate-polyarylate block copolymer contains a cyano group, and the cyano group content is 0.1 to 0.65wt%.

Example 1

The preparation method of the high-impact-resistance and high-heat-resistance transparent optical material comprises the following specific steps:

pretreatment of PMMA resin: drying for 4h in a forced air oven at 110 ℃ for later use.

Pretreatment of PC resin: drying for 4h in a forced air oven at 130 ℃ for later use.

Pretreatment of the compatibilizer: drying for 4h at 120 ℃ in a blast oven for later use.

The PMMA resin is commercially available optical-grade syndiotactic polymethyl methacrylate, and the light transmittance of SP-01,3mm produced by Nippon Coli is 93%, the haze of 3mm is 0.3%, and the melt index is 1.0g/10min (230 ℃/load is 3.8 kg).

The PC resin is a commercial aromatic copolycarbonate, apec 2097,3mm light transmittance produced by Kestewa of Belgium is 88%,3mm haze is 0.5%, and melt index is 8.0g/10min (330 ℃/load is 2.16 kg).

The compatibilizer is a block copolymer of formulas 1-1 and 2, mn is about 8000g/mol, n =1,m =60, the mass fraction of the pmma component is about 75%, the mass fraction of the PAR component is about 25%, and the cyano group in the compatibilizer is about 0.65wt%.

The lubricant is commercial liquid C ₁₅ ～C ₂₂ Saturated alkane mixture, 80wt% of cycloalkanes and 20wt% of linear alkanes. The kinematic viscosity at 40 ℃ of the liquid saturated alkane mixture is 50mm ² (s) has a number average molecular weight of 200g/mol.

In the embodiment of the invention, the pretreated PMMA resin, PC resin, compatibilizer and lubricant are weighed according to the weight ratio of 80.

In the embodiment of the invention, the fully mixed raw materials are added into a hopper of a double-screw extruder, and the high-impact-resistance and high-heat-resistance transparent optical material is obtained through extrusion, melting and granulation.

Wherein the temperature of a first zone of the double-screw extruder is 230 ℃, the temperature of a second zone is 240 ℃, the temperature of a third zone is 245 ℃, the temperature of a fourth zone is 250 ℃, the temperature of a fifth zone is 255 ℃, the temperature of a sixth zone is 260 ℃, the temperature of a seventh zone is 265 ℃ and the temperature of a machine head is 270 ℃; the screw speed was 80rpm.

Example 2

pretreatment of PMMA resin: drying for 8h in a forced air oven at 90 ℃ for later use.

Pretreatment of PC resin: drying for 8h in a forced air oven at 100 ℃ for later use.

Pretreatment of the compatibilizer: drying for 8h in a forced air oven at 100 ℃ for later use.

The PMMA resin was commercially available isotactic polymethyl methacrylate, LG2 manufactured by Nippon Sumitomo chemical Co., ltd., light transmittance at 3mm of 93%, haze at 3mm of 0.5%, and melt index of 15g/10min (230 ℃/load of 3.8 kg).

The PC resin is a commercial aromatic copolymerization type polycarbonate and LEXAN PC CXT17 which is a Saber basic innovation plastic, the light transmittance of 3mm is 87%, the haze of 3mm is 1.0%, and the melt index is 33g/10min (330 ℃/load is 2.16 kg).

The compatibilizer is a block copolymer of formula 1-2 and formula 2, mn is about 50000g/mol, n =1,m =60, the mass fraction of the pmma component is about 60%, the mass fraction of the PAR component is about 25%, and the cyano groups on the compatibilizer backbone are about 0.10wt%.

The lubricant is commercial liquid C ₃₁ ～C ₃₈ Saturated alkane mixture, 60wt% of cycloalkane and 40wt% of linear alkane. The kinematic viscosity at 40 ℃ of the liquid saturated alkane mixture is 200mm ² (s) has a number average molecular weight of 500g/mol.

In the embodiment of the invention, the pretreated PMMA resin, PC resin, compatibilizer and lubricant are weighed according to the weight ratio of 60 to 12, and are added into a high-speed mixer to be mixed for 10min at the speed of 200r/min at normal temperature for later use.

Wherein the temperature of a first area of the double-screw extruder is 210 ℃, the temperature of a second area is 220 ℃, the temperature of a third area is 225 ℃, the temperature of a fourth area is 230 ℃, the temperature of a fifth area is 235 ℃, the temperature of a sixth area is 240 ℃, the temperature of a seventh area is 245 ℃, and the temperature of a machine head is 250 ℃; the screw speed was 300rpm.

Example 3

pretreatment of PMMA resin: drying for 6h in a blast oven at 95 ℃ for later use.

Pretreatment of PC resin: drying for 6h in a forced air oven at 110 ℃ for later use.

Pretreatment of the compatibilizer: drying for 6h in a forced air oven at 110 ℃ for later use.

The PMMA resin is commercially available optical-grade syndiotactic polymethyl methacrylate, HR1000R produced by Nippon Coli, the light transmittance of 3mm is 92%, the haze of 3mm is 0.3%, and the melt index is 2.4g/10min (230 ℃/load is 3.8 kg).

The PC resin was a commercially available aromatic polycarbonate, S-3000VR (version without flame retardant added) from Mitsubishi engineering plastics corporation, 3mm light transmittance was 87%,3mm haze was 1.0%, and melt index was 15g/10min (330 ℃/load was 2.16 kg).

The compatibilizer is a block copolymer of formula 1-1 and formula 2, mn is about 20000g/mol, n =19,m =108, the mass fraction of the pmma component is about 65%, the mass fraction of the PAR component is about 35%, and the cyano group in the compatibilizer is about 0.26wt%.

The lubricant is commercial liquid C ₂₀ ～C ₂₇ Saturated alkane mixture, 65% by weight of cycloalkanes and 35% by weight of linear alkanes. The kinematic viscosity at 40 ℃ of the liquid saturated alkane mixture is 100mm ² (s) a number average molecular weight of 250g/mol.

In the embodiment of the invention, the pretreated PMMA resin, PC resin, compatibilizer and lubricant are weighed according to the weight ratio of 75.

Wherein the temperature of a first area of the double-screw extruder is 220 ℃, the temperature of a second area is 230 ℃, the temperature of a third area is 235 ℃, the temperature of a fourth area is 240 ℃, the temperature of a fifth area is 245 ℃, the temperature of a sixth area is 250 ℃, the temperature of a seventh area is 255 ℃, and the temperature of a machine head is 260 ℃; the screw speed was 150rpm.

Comparative example 3-1

In this comparative example, no PC resin, compatibilizer and lubricant were added, and an optical material was prepared according to the formulation and procedure of example 3.

Comparative examples 3 to 2

In this comparative example, no PMMA resin, compatibilizer and lubricant were added, and the optical material was prepared according to the formulation and procedure of example 3.

Comparative examples 3 to 3

In this comparative example, no compatibilizer and lubricant were added, and the formulation and procedure of example 3 were otherwise followed to prepare an optical material.

Example 4

pretreatment of PMMA resin: drying for 5h in a forced air oven at 100 ℃ for later use.

Pretreatment of PC resin: drying for 5h at 120 ℃ in a blast oven for later use.

Pretreatment of the compatibilizer: drying for 5h in a forced air oven at 115 ℃ for later use.

The PMMA resin is commercially available optical grade isotactic polymethyl methacrylate, GH-S produced by Nippon Korea, the light transmittance of 3mm is 92%, the haze of 3mm is 0.3%, and the melt index is 10g/10min (230 ℃/load is 3.8 kg).

The PC resin is a commercial aromatic copolycarbonate, and Apec 1803,3mm produced by Kestewa, belgium has the light transmittance of 88%, the haze of 0.5% and the melt index of 10g/10min (330 ℃/load of 2.16 kg).

The compatibilizer is a block copolymer of formulas 1-2 and 2, mn is about 40000g/mol, n =833, m =233, the mass fraction of the pmma component is about 70%, the mass fraction of the PAR component is about 30%, and the cyano group in the compatibilizer is about 0.13wt%.

The lubricant is commercial liquid C ₂₃ ～C ₃₀ Saturated alkane mixture, 75wt% of cycloalkanes and 25wt% of linear alkanes. The kinematic viscosity at 40 ℃ of the mixture of liquid saturated alkanes is150mm ² (s) a number average molecular weight of 350g/mol.

In the embodiment of the invention, the pretreated PMMA resin, PC resin, compatibilizer and lubricant are weighed according to the weight ratio of 70.

According to the embodiment of the invention, the fully mixed raw materials are added into a hopper of a double-screw extruder, and the high-impact high-heat-resistance transparent optical material is obtained through extrusion, melting and granulation.

Wherein the temperature of a first zone of the double-screw extruder is 225 ℃, the temperature of a second zone is 235 ℃, the temperature of a third zone is 240 ℃, the temperature of a fourth zone is 245 ℃, the temperature of a fifth zone is 250 ℃, the temperature of a sixth zone is 255 ℃, the temperature of a seventh zone is 260 ℃ and the temperature of a machine head is 265 ℃; the screw speed was 240rpm.

Comparative example 4-1

In this comparative example, no compatibilizer was added, and the formulation and procedure of example 4 were otherwise followed to prepare an optical material.

Comparative example 4 to 2

In this comparative example, the compatibilizer was replaced with maleic anhydride compatibilizer (MMA-g-St/MAH), and the preparation method was conducted in accordance with example 1 of CN201410282542.2, which is a Chinese patent, while the optical material was prepared according to the formulation and procedure of example 4.

Comparative examples 4 to 3

In this comparative example, the compatibilizer was replaced with a hyperbranched PMMA compatibilizer, and the preparation method was performed according to Wu Shengkun, sample 4-1 synthesized from hyperbranched polymethylmethacrylate and rheological properties thereof, mn = 2400g/mol, and kinematic viscosity (30 ℃) was 12000cp, while the optical material was prepared according to the formulation and procedure of example 4.

Comparative examples 4 to 4

In this comparative example, no lubricant was added, and the optical material was prepared according to the formulation and procedure of example 4.

Comparative examples 4 to 5

The lubricant in this comparative example was changed to a commercially available liquid C ₂₃ ～C ₃₀ Alkane mixtures, 65wt% of cycloalkane, 15wt% of linear alkane, 10wt% of cycloalkane aromatic hydrocarbon and 10wt% of alkyl aromatic hydrocarbon. The kinematic viscosity at 40 ℃ of the liquid alkane mixture is 150mm ² (s) a number average molecular weight of 350g/mol. And the other optical materials were prepared according to the formulation and procedure of example 4.

The performance indexes of the high impact resistant and high heat resistant transparent optical materials prepared in the examples and the comparative examples are as follows:

TABLE 1 comparison of Performance indices of examples 1-4 with comparative examples

As can be seen from tables 1 and 2, the high impact resistant, high heat resistant transparent optical material of the present invention (examples 1 to 4) not only has excellent optical characteristics and scratch resistance of the conventional PMMA material, but also has good impact resistance, heat resistance stability and certain flame retardancy, and has good toughness even without stretch orientation. The conventional PMMA material (comparative example 3-1) was not only flammable but also had very poor impact resistance and toughness if it was not biaxially stretched. The PC resin having excellent heat resistance and impact resistance (comparative example 3-2) is an ideal heat-resistant toughening modifier for PMMA resin. However, simple blend modification of PMMA resin using PC resin (comparative examples 3-3 and 4-1) is not able to improve the heat resistance and impact resistance of the blend directly and efficiently, and the addition of PC resin results in a decrease in rigidity (tensile strength) of PMMA resin. Secondly, PMMA and PC are partial compatible systems, and are directly blended to generate a phase separation phenomenon, so that the ideal high-impact high-heat-resistance transparent optical material cannot be obtained. The compatibilizer added in the invention is a PMMA-PAR block copolymer, and has natural compatibility with PMMA resin which is a main material. At temperatures above 240 ℃ during melt blending, transesterification occurs between the aromatic ester groups of the PAR component and the carbonate groups of the PC, even without the addition of a catalyst, to form a PC-PAR-PMMA graft copolymer at the PMMA/PC two-phase interface. The graft copolymer can play a role of a compatibilizer between PMMA and PC, so that the compatibility between PMMA and PC is effectively improved, and the high-transparency high-transmittance low-haze optical material is obtained. Thus avoiding the addition of the catalyst, and not causing the degradation of the components in the system and the reduction of the molecular weight, thereby causing serious influence on the mechanical property and the heat resistance of the blend.

Table 2 results of performance test of example 4 and comparative examples

As can be seen from Table 2, compared with the PMMA/PC blend without the compatibilizer (comparative example 4-1), when the maleic anhydride compatibilizer (comparative example 4-2) or the hyperbranched PMMA modifier (comparative example 4-3) is used, the compatibility of the PMMA/PC blend is improved to different degrees, the mechanical property is obviously improved, and the heat resistance is slightly improved, but the interface is only improved, the molecular-level compatibility is not achieved, the improvement effect is not obvious with the PMMA-PAR block high polymer of the invention, so the haze (> 10%) and the weather resistance improvement effect of the PMMA/PC blend are not ideal, and the flame resistance is not improved at all. The PAR component using the compatibilizer of the invention has high refractive index, good rigidity and wear resistance, excellent high temperature resistance and weather resistance (ultraviolet resistance) and self-extinguishing property. Not only can better improve the reduction of rigidity, weather resistance and wear resistance of the optical material caused by the introduction of PC resin, but also can further improve the heat resistance of the optical material and improve the flame retardance of the optical material. Secondly, the PMMA-PAR segmented copolymer adopted in the compatibilizer contains cyano on the main chain, so that the oil resistance of the optical material can be effectively improved.

In comparison with example 4 of the present invention, when no lubricant was added (comparative examples 4 to 4), there was a remarkable decrease in physical and mechanical properties, and the optical properties and surface abrasion resistance (surface hardness) were also deteriorated. This is because the melt viscosity and processing process difference of PMMA and PC are large, the melting point of PC resin is high, and the fluidity of PC resin is poor under the PMMA processing temperature condition. In order to ensure complete melting and plasticizing of the PC resin, the processing temperature conditions are higher than those of PMMA. At the moment, the PMMA component has a certain degradation phenomenon, a small amount of bubbles are generated, the compatibility of a blending system is deteriorated, the physical property is sharply reduced, and the appearance of the blend is semitransparent. These can have a severe impact on the overall mechanical and optical properties of the blend article and also limit the use of PMMA/PC blends in transparent optics applications. The lubricant of the invention adopts the inert saturated alkane mixture (cycloalkane and straight-chain alkane) with low molecular weight and low boiling point, and in the PMMA/PC blend processing process, part of the lubricant can permeate into the molecular chain to play the role of internal lubrication, improve the fluidity of PC resin and reduce the processing temperature of the blend. Due to the lower boiling point, another part can migrate to the surface of the resin, the frictional heat and abrasion of the resin and equipment are reduced, and due to the lower molecular weight, the resin is completely volatilized at the die head of the extruder, no residue is left in the blend, and the surface of the blend is smooth. When unsaturated naphthenic, alkylaromatic or polycyclic aromatic hydrocarbons are added to the lubricant (comparative examples 4 to 5), the overall properties of the PMMA/PC blend, particularly the physical and mechanical properties and the weather resistance, are reduced due to the aromatic components, which have relatively high boiling points (trace amounts of residues in the blend), poor thermal stability and less desirable low temperature properties.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The high-impact-resistance high-heat-resistance transparent optical material is characterized in that the melt blending preparation raw materials comprise:

60-80 parts of PMMA resin, 15-26 parts of PC resin, 4.5-12 parts of compatibilizer and 0.5-2 parts of lubricant;

the compatibilizer is a polymethyl methacrylate-polyarylate block copolymer, and the structural formula of the compatibilizer comprises a main chain first structure shown in a formula 1 and a main chain second structure shown in a formula 2; the lubricant is C ₁₅ ~C ₃₈ A liquid saturated alkane mixture of (a);

formula 1;

and (3) formula 2.

2. The high impact, high heat resistant transparent optical material as claimed in claim 1, wherein the compatibilizer is polymethyl methacrylate-polyarylate block copolymer having number average molecular weight Mn =8000 to 50000g/mol.

3. The high-impact high-heat-resistant transparent optical material as claimed in claim 2, wherein the polymethyl methacrylate-polyarylate block copolymer contains cyano groups in the main chain, and the cyano group content is 0.1 to 0.65wt% based on the mass percentage of the block copolymer.

4. The high-impact high-heat-resistant transparent optical material according to claim 1, wherein the liquid saturated alkane mixture comprises 60 to 80wt% of cycloalkane and 20 to 40wt% of linear alkane.

5. The high-impact-resistant high-heat-resistant transparent optical material as claimed in claim 4, wherein the kinematic viscosity at 40 ℃ of the liquid saturated alkane mixture is 50 to 200mm ² /s。

6. The high-impact high-heat-resistant transparent optical material as claimed in claim 1, wherein the PMMA resin has a light transmittance of not less than 92% at 3mm and a haze of not more than 0.5% at 3 mm.

7. The high-impact high-heat-resistant transparent optical material as claimed in claim 6, wherein the PMMA resin has a melt index of 1.0g/10min to 15g/10min at 230 ℃ and 3.8 kg.

8. The high impact, high heat resistant transparent optical material according to claim 1, wherein the PC resin is an aromatic polycarbonate and/or an aromatic copolycarbonate.

9. The high-impact high-heat-resistant transparent optical material as claimed in claim 8, wherein the PC resin has a melt index of 6 to 33g/10min at 330 ℃ under 1.2 kg.

10. The high-impact high-heat-resistant transparent optical material as claimed in claim 8, wherein the PC resin has a light transmittance of 87% or more at 3mm and a haze of 1.0% or less at 3 mm.

11. The high impact and high heat resistant transparent optical material as claimed in any one of claims 1 to 10, wherein the high impact and high heat resistant transparent optical material has a light transmittance of 90% or more at 3mm and a haze of 1.0% or less at 3 mm.

12. The high impact, high heat resistant transparent optical material of claim 11, wherein the high impact, high heat resistant transparent optical material has a yellowness index < 1 and/or has a certain flame retardancy.

13. The method for preparing a high impact, high heat resistant transparent optical material according to any one of claims 1 to 12, comprising the steps of:

drying the raw materials respectively, mixing the raw materials according to the weight ratio, and performing melt extrusion at the temperature of 210-270 ℃ to obtain the high-impact-resistance high-heat-resistance transparent optical material.