Transparent pc tape carrier permanent material and its preparation method

Abstract

The application relates to the technical field of high polymer modified materials, and discloses a transparent PC carrier tape permanent antistatic material and a preparation method thereof. The material is made of bisphenol A polycarbonate resin, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, polyether ester block copolymer, potassium perfluorobutyl sulfonate, polymeric carbodiimide and an antioxidant. During preparation, the base and the compatibilizer are premelted, and then a premixed material containing an ionic salt, a crosslinking agent and polyether ester is added into the main melt through downstream side feeding. The open ring grafting reaction of the compatibilizer is used to reduce the interfacial tension, the dispersed phase is refined to maintain high light transmittance, a polyurea network formed through in-situ crosslinking of carbodiimide is used to form physical confinement, potassium ions are enclosed in the dispersed phase, the migration and catalytic degradation effect of the potassium ions are inhibited, and the material has the advantages of persistent antistatic property, high transparency and good mechanical strength.

Description

Technical Field

[0001] This invention relates to the field of polymer modified materials technology, specifically to a transparent PC carrier tape permanent protective material and its preparation method. Background Technology

[0002] Polycarbonate materials possess excellent light transmittance, dimensional stability, and mechanical strength, making them commonly used in packaging carriers for semiconductors and electronic components. Because electronic components are highly sensitive to static electricity, antistatic modification of the polycarbonate substrate is typically required in practical applications. Conventional modification methods mainly rely on adding small-molecule or high-molecular-weight antistatic agents.

[0003] When using small-molecule ionic antistatic agents, these substances tend to migrate outward from the polymer matrix, causing a significant decline in the material's antistatic properties after friction, washing, or long-term storage. Furthermore, these metal-ion-containing antistatic agents often exhibit catalytic activity under high-temperature melting conditions, easily initiating the breakage of polycarbonate macromolecular chains and transesterification reactions, leading to yellowing and a decrease in fundamental mechanical properties such as tensile strength and impact resistance. If switching to polymeric antistatic agents such as polyether esters, a larger addition amount is typically required to achieve surface resistivity at the electrostatic dissipation level. Due to the limited compatibility between polymeric antistatic agents and the polycarbonate matrix and the difference in refractive index, a large addition can cause phase separation within the system. The resulting microscopic rough interfaces cause internal light scattering, thereby compromising the original high light transmittance of polycarbonate and weakening the material's mechanical strength. Existing conventional blending methods struggle to achieve a durable and stable antistatic effect while maintaining high transparency and mechanical strength. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a transparent PC carrier tape permanent antistatic material and its preparation method. This solves the problems of conventional small-molecule antistatic agents being prone to surface migration, which often leads to poor antistatic performance and easy catalytic degradation of the matrix, causing yellowing and mechanical property degradation; while using high-molecular-weight antistatic agents alone requires a high amount, which will damage the transparency and mechanical strength of polycarbonate.

[0005] To address the above problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a transparent PC carrier tape permanent protective material, which adopts the following technical solution: A transparent PC carrier tape permanent protective material is made from the following raw materials in parts by weight: 88-92 parts of bisphenol A type polycarbonate resin, 1-2 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 5-8 parts of polyether ester block copolymer, 0.1-0.3 parts of potassium perfluorobutyl sulfonate, 0.3-0.5 parts of polymeric carbodiimide, and 0.2-0.4 parts of antioxidant composition.

[0006] In constructing the antistatic network, the polyether ester block copolymer is dispersed within the polycarbonate matrix, and the resulting microstructure provides ion transport channels to a certain extent; while potassium perfluorobutyl sulfonate tends to accumulate within the polyether phase. Through this microstructure of phase separation, electrostatic charges can be dissipated by the migration of ions within the polyether network, thereby achieving the antistatic purpose and reducing the shedding of ionic salts.

[0007] Interfacial reactions are equally crucial for microstructure control. During melt processing, the epoxy groups in the ethylene-methyl acrylate-glycidyl methacrylate terpolymer readily undergo ring-opening and addition reactions with the end groups of both polycarbonate resin and polyether ester block copolymer. This covalent bonding at the phase interface helps reduce interfacial tension, thereby controlling the micro-region size of the dispersed phase as much as possible below the visible light wavelength, which is essential for maintaining the macroscopic transparency of the material.

[0008] Furthermore, potassium perfluorobutyl sulfonate may catalyze the chain breakage of polycarbonate under certain conditions. When a polymeric carbodiimide is introduced into the system, the carbodiimide group (-N=C=N-) in its molecular structure reacts with trace amounts of moisture in the environment or raw materials to generate a -NH-CO-NH- structure to consume the moisture; moreover, this group can also react with the degradative carboxyl group of polycarbonate to generate a blocked N-acylurea derivative. This process largely blocks autocatalytic hydrolysis and plays a positive role in maintaining the molecular weight of the matrix.

[0009] Preferably, it is made from raw materials comprising the following parts by weight: 89-91 parts of bisphenol A type polycarbonate resin, 1.2-1.8 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 6-7 parts of polyether ester block copolymer, 0.15-0.25 parts of potassium perfluorobutyl sulfonate, 0.35-0.45 parts of polymeric carbodiimide, and 0.25-0.35 parts of antioxidant composition.

[0010] When using the above-mentioned preferred weight proportions, the degree of interfacial compatibilization and the connectivity of the antistatic network can often achieve a relatively better balance. At this time, the crosslinking density provided by the epoxy groups in the system can not only better control the phase region size of the polyether ester, but also usually avoid the sharp decline in melt fluidity caused by excessive crosslinking, thereby maintaining the rheological characteristics of the material suitable for extrusion processing.

[0011] Preferably, the antioxidant composition consists of tris(2,4-di-tert-butylphenyl) phosphite and tris(nonylphenol) phosphite, and the weight ratio of the two is 1.5:1 to 2.5:1.

[0012] In the aforementioned antioxidant composition, tris(2,4-di-tert-butylphenyl) phosphite possesses the structural characteristics of both hindered phenols and phosphites, tending towards hydroperoxides generated during decomposition and processing; while tris(nonylphenol) phosphite exhibits a certain free radical scavenging ability. When these two are combined in this ratio, a synergistic effect is often easily achieved under heating conditions, thereby effectively delaying the thermo-oxidative aging process of polycarbonate during processing and reducing the yellowing of the matrix.

[0013] Preferably, the polyether ester block copolymer is a block copolymer composed of alternating links of polybutylene terephthalate as hard segments and polytetrahydrofuran ether as soft segments.

[0014] The polybutylene terephthalate hard segments in this copolymer typically form crystalline microregions, acting as physical cross-linking points to help stabilize the antistatic network structure; the polytetrahydrofuran ether soft segments it contains, due to their relatively low glass transition temperature and flexible molecular chain movement, can promote the dissolution and ion migration of potassium perfluorobutyl sulfonate to a certain extent, thereby ensuring the charge dissipation efficiency.

[0015] Preferably, the melt flow rate of the bisphenol A type polycarbonate resin under test conditions of 300°C and 1.2kg is 10-15g / 10min; and the mass fraction of glycidyl methacrylate monomer in the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is 6%-10%.

[0016] Polycarbonates with end-group concentrations within this melt flow rate range often achieve a better reaction match with terpolymers containing a defined GMA content. Controlling the GMA mass fraction within this range provides an appropriate number of crosslinking sites while reducing the risk of localized gelation, making the compatibilization reaction at the interface more controllable.

[0017] Secondly, this invention provides a method for preparing a transparent PC carrier tape permanent protective material, employing the following technical solution: A method for preparing a transparent PC carrier tape permanent protective material includes the following steps: Step S1: Add bisphenol A type polycarbonate resin, ethylene-methyl acrylate-glycidyl methacrylate terpolymer and part of antioxidant composition to a mixer and mix evenly. Then feed the mixture through the main feed port of a twin-screw extruder for melt extrusion. Step S2: The polyether ester block copolymer, potassium perfluorobutyl sulfonate, polymeric carbodiimide and the remaining antioxidant composition are put into a mixer with a heating jacket for low-speed hot mixing to obtain a pretreated mixture. Step S3: The pretreated mixture obtained in step S2 is quantitatively fed into the main melt through a forced side feeder downstream of the twin-screw extruder; Step S4: The material continues to enter the downstream section of the extruder. In this section, vacuum exhaust is turned on to remove low molecular weight volatiles, and forced cooling cycle is turned on at the same time to cool down the melt and increase its viscosity. Step S5: The melt is extruded through the die head to form a strip, which is then rapidly cooled and shaped in a water bath, dried by blowing off the surface moisture, and then granulated and dried to obtain a transparent PC carrier tape permanent protective material.

[0018] The aforementioned staged feeding and pretreatment operations are essentially for more precise control of the phase evolution of the multi-component system during extrusion processing: During the pretreatment of excipients, thanks to the heating conditions of the mixer, potassium perfluorobutyl sulfonate particles tend to adsorb onto the surface of polyether ester block copolymer particles and gradually penetrate them, while the outer layer may be moderately coated by polymeric carbodiimide. This not only initially establishes the aggregated form of the antistatic component, but also incidentally utilizes carbodiimide to remove trace amounts of adsorbed water hidden in the excipient system.

[0019] The matrix melting stage then begins, with the polycarbonate resin and terpolymer entering the melting zone first. Due to the mechanical shearing effect of the twin-screw extruder, the active epoxy groups in the terpolymer are exposed and dispersed within the polycarbonate melt, pre-arranging relatively uniform active sites for subsequent interfacial reactions.

[0020] As for the side-feeding and morphology-locking operations, they are mainly to shorten the residence time of excipients such as polyether esters in a high-temperature, high-shear environment. After the pretreated excipients enter the main fluid, their polyether ester phase will be stretched into microfibers or networks in the shear flow field; then, through the downstream cooling and thickening steps, this microscopic phase can be rapidly "frozen" to a large extent, preventing secondary agglomeration of the dispersed phase.

[0021] Preferably, in step S1, the mixing is carried out at room temperature for 3 to 5 minutes; the set temperature of the first to fourth zones of the twin-screw extruder is 265 to 275°C, the main screw speed is 350 to 400 rpm, and the screw in this zone is equipped with 2 to 3 sets of staggered kneading blocks.

[0022] Setting the barrel temperature to 265–275°C and coordinating it with the aforementioned screw speed facilitates the smooth transition of polycarbonate across the glass transition zone and its melting. The staggered kneading blocks configured in this section can forcibly untangle the macromolecular chain entanglements of polycarbonate through mechanical actions such as folding and shearing. This, to a certain extent, is beneficial to the deep dispersion of the terpolymer, laying the foundation for the uniformity of the subsequent grafting reaction.

[0023] Preferably, in step S2, the temperature of the mixer with the heating jacket is set to maintain the material at 70-80°C, and the low-speed stirring time is 15-20 minutes.

[0024] At a pretreatment temperature of 70–80°C, the thermal motion of the molecular chains in the polyether soft segments is significantly intensified. This change in physical state helps to promote the deeper diffusion and fusion of potassium perfluorobutyl sulfonate into the polyether phase, thereby reducing the probability of ionic salts migrating and precipitating to the surface during the use of the finished product, which is quite beneficial for extending the effective life of the antistatic function.

[0025] Preferably, in step S3, the forced side feeder is located in zone 5 of the twin-screw extruder, and the barrel temperature of this zone is set to 255–265°C.

[0026] The barrel temperature in Zone 5 is appropriately lowered compared to the previous section. This is to prevent the melt from backflowing at the side feed port and to slow down the premature consumption of the active groups of carbodiimide to some extent, in addition to preventing backflow of the melt.

[0027] Preferably, in step S4, the vacuum gauge pressure of the section where the exhaust port is located is maintained at -0.09MPa to -0.095MPa, and the barrel setting temperature of this section is gradually reduced to 250 to 255°C by forced cooling water circulation; in step S5, the setting temperature of the 8th zone of the extruder and the die head is 250 to 255°C, and the temperature of the circulating water in the water tank is 15 to 25°C.

[0028] Vacuum venting allows for the timely removal of reaction byproducts and other low-molecular-weight volatiles. Simultaneously, forced cooling gradually lowers the local barrel temperature to 250–255°C, resulting in a moderate increase in melt viscosity. This high-viscosity state spatially restricts the collision and fusion of the already formed fine polyether ester phases. Finally, the extruded strip is rapidly cooled and set in a water bath at 15–25°C, helping to quickly "lock" the polycarbonate matrix in a highly amorphous state, thereby ensuring the optical transmittance of the finished product.

[0029] This invention provides a transparent PC carrier tape permanent protective material and its preparation method. It has the following beneficial effects: 1. This invention introduces a polymeric carbodiimide, which undergoes a crosslinking reaction with residual end groups on the surface of the polyether ester dispersed phase, generating a micro-crosslinked polyurea network in situ. This network structure forms a physical confinement in space, restricting potassium perfluorobutyl sulfonate within the polyether ester phase region and inhibiting the migration of conductive ions to the polycarbonate matrix or the outside. This structural design reduces the loss of small molecule salts during contact with water or long-term use, allowing the material to maintain a surface resistivity of the same order of magnitude after washing, thus achieving relatively stable and durable antistatic properties. 2. This invention utilizes an ethylene-methyl acrylate-glycidyl methacrylate terpolymer for interface regulation. During melt extrusion, the epoxy groups on its molecular chain undergo a ring-opening reaction, forming chemical bonds with the end groups of both the matrix and the dispersed phase. This in-situ reaction effectively reduces the interfacial tension between the polycarbonate continuous phase and the polyether ester dispersed phase, promoting the refinement of the polyether ester phase under shear stress and controlling its droplet size below the visible light wavelength. The reduction in phase size weakens the scattering of incident light by the multi-component system, allowing the modified material to maintain high transmittance. 3. The material formulation of this invention, combined with the downstream feeding process, mitigates the damage to the mechanical properties of polycarbonate caused by antistatic modification. By feeding the potassium-containing polyether ester premix from the rear of the extruder, the heat exposure time of active metal ions in the high-temperature barrel is shortened; simultaneously, in conjunction with the aforementioned generated interfacial polyurea network, direct contact between potassium ions and the polycarbonate macromolecular chains is physically isolated. This mechanism inhibits matrix transesterification and chain-breaking degradation induced by ion catalysis during high-temperature processing, allowing the material to retain its basic tensile yield strength and impact toughness while possessing antistatic properties. Attached Figure Description

[0030] Figure 1 These are the infrared spectra and rheological property curves of Example 1 of the present invention and the comparative sample; Among them, (a) represents the samples at 4000 cm. -1 Up to 400cm -1 (a) Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectrum within the range; (b) Scan curve of dynamic rheological complex viscosity of each sample at 260℃ as a function of angular frequency (0.1~100rad / s); Figure 2 This is a comparison of the molecular weight distribution curves of the material in Example 1 of this invention and the comparative sample by gel permeation chromatography (GPC). Figure 3 These are DSC thermal transformation curves of the pure polycarbonate resin of the present invention, the material of Example 1, the material of Comparative Example 3, and the material of Comparative Example 4; wherein, (a) is the DSC exothermic curve of crystallization during the cooling process, and (b) is the DSC curve of the second heating. Figure 4 This is a flowchart of the method of the present invention. Detailed Implementation

[0031] The following are specific embodiments of the present invention, which further describe the technical solution of the present invention in conjunction with the embodiments. However, the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any modifications, equivalent substitutions, or improvements made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

[0032] The sources and specifications of the main raw materials and reagents used in the following examples and comparative examples are as follows. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0033] Bisphenol A type polycarbonate resin, CAS No. 25037-45-0, melt index 10g / 10min to 15g / 10min, test conditions 300℃ / 1.2kg.

[0034] The polyether ester block copolymer, CAS number 37282-12-5, has a structure consisting of hard segments made of polybutylene terephthalate and soft segments made of polytetrahydrofuran ether, with a mass ratio of hard segments to soft segments of 40:60 and a number average molecular weight of 15000 g / mol to 25000 g / mol.

[0035] The terpolymer of ethylene-methyl acrylate-glycidyl methacrylate, CAS No. 51540-39-7, wherein the mass fraction of glycidyl methacrylate unit is 8% to 10%, the melt index is 6 g / 10 min, and the test conditions are 190℃ / 2.16 kg.

[0036] Potassium perfluorobutyl sulfonate, CAS No. 29420-49-3, purity ≥99.0%.

[0037] Polymerized carbodiimide, CAS number 29961-43-1, chemical name poly(1,3,5-triisopropylbenzene-2,4-diimide), with an average degree of polymerization n of 4 to 6.

[0038] Example 1: This example provides a method for preparing a transparent PC carrier tape permanent protective material, specifically including the following steps: (1) Premixing and feeding of main materials: 90 parts of bisphenol A type polycarbonate resin, 1.5 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer and 0.2 parts of tris(2,4-di-tert-butylphenyl) phosphite were added to a high-speed mixer and mixed at room temperature for 4 minutes until uniform. Then the mixture was fed into the main feed port of a co-rotating parallel twin-screw extruder. The temperature of the first to fourth zones of the extruder was set to 270°C and the main screw speed was 380 rpm. Two sets of staggered kneading blocks were configured on the screw in this zone.

[0039] (2) Heating and premixing of auxiliary materials: 6.5 parts of polyether ester block copolymer, 0.2 parts of perfluorobutyl sulfonate potassium, 0.4 parts of polymeric carbodiimide and 0.1 parts of tris(nonylphenol) phosphite were put into a low-speed mixer with a heating jacket. The heating temperature was set to maintain the material at 75°C and the mixture was stirred at low speed for 18 minutes to obtain the pretreated mixture.

[0040] (3) Side feeding mixing: The pre-treated mixture obtained in step (2) is quantitatively fed into the main melt through the twin-screw forced side feeder in zone 5 of the twin-screw extruder, and the barrel temperature in zone 5 is set to 260°C.

[0041] (4) Vacuum exhaust and cooling: When the material enters the 6th and 7th zones of the extruder, the vacuum pump at the exhaust port is turned on to maintain the vacuum degree of the section where the exhaust port is located at -0.092MPa. The vacuum degree is the gauge pressure value. According to the standard atmospheric pressure of 0.101MPa, the corresponding absolute pressure is about 0.009MPa. At the same time, the forced cooling water circulation is turned on in this section to make the barrel set temperature drop slowly to 252℃. The screw configuration in this section adopts a large lead conveying thread element.

[0042] (5) Extrusion quenching and pelletizing: The temperature of the 8th zone of the extruder and the die head is set to 252°C. The melt is extruded through the multi-hole die head to form a continuous strip, which is drawn into a 20°C circulating water tank for quenching and shaping. After the residual moisture on the surface is blown off by a high-pressure air knife, it enters the pelletizer to cut into slices. After drying, transparent PC carrier tape permanent protective material is obtained.

[0043] Example 2: This example provides a method for preparing a transparent PC carrier tape permanent protective material, specifically including the following steps: (1) Premixing and feeding of main materials: 92 parts of bisphenol A type polycarbonate resin, 1 part of ethylene-methyl acrylate-glycidyl methacrylate terpolymer and 0.2 parts of tris(2,4-di-tert-butylphenyl) phosphite were added to a high-speed mixer and mixed at room temperature for 4 minutes until uniform. Then the mixture was fed into the main feed port of a co-rotating parallel twin-screw extruder. The temperature of the first to fourth zones of the extruder was set to 270°C and the main screw speed was 380 rpm. Two sets of staggered kneading blocks were configured on the screw in this zone.

[0044] (2) Heating and premixing of auxiliary materials: 5 parts of polyether ester block copolymer, 0.1 parts of perfluorobutyl sulfonate potassium, 0.3 parts of polymeric carbodiimide and 0.1 parts of tris(nonylphenol) phosphite were put into a low-speed mixer with a heating jacket. The heating temperature was set to maintain the material at 75°C. The mixture was stirred at low speed for 18 minutes to obtain the pretreated mixture.

[0045] (3) Side feeding mixing: The pre-treated mixture obtained in step (2) is quantitatively fed into the main melt through the twin-screw forced side feeder in zone 5 of the twin-screw extruder, and the barrel temperature in zone 5 is set to 260°C.

[0046] (4) Vacuum exhaust and cooling: When the material enters the 6th and 7th zones of the extruder, the vacuum pump at the exhaust port is turned on to maintain the vacuum degree of the section where the exhaust port is located at -0.092MPa. The vacuum degree is the gauge pressure value. According to the standard atmospheric pressure of 0.101MPa, the corresponding absolute pressure is about 0.009MPa. At the same time, the forced cooling water circulation is turned on in this section to make the barrel set temperature drop slowly to 252℃. The screw configuration in this section adopts a large lead conveying thread element.

[0047] (5) Extrusion quenching and pelletizing: The temperature of the 8th zone of the extruder and the die head is set to 252°C. The melt is extruded through the multi-hole die head to form a continuous strip, which is drawn into a 20°C circulating water tank for quenching and shaping. After the residual moisture on the surface is blown off by a high-pressure air knife, it enters the pelletizer to cut into slices. After drying, transparent PC carrier tape permanent protective material is obtained.

[0048] Example 3: This example provides a method for preparing a transparent PC carrier tape permanent protective material, specifically including the following steps: (1) Premixing and feeding of main materials: 88 parts of bisphenol A type polycarbonate resin, 2 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer and 0.2 parts of tris(2,4-di-tert-butylphenyl) phosphite were added to a high-speed mixer and mixed at room temperature for 4 minutes until uniform. Then the mixture was fed into the main feed port of a co-rotating parallel twin-screw extruder. The temperature of the first to fourth zones of the extruder was set to 270°C and the main screw speed was set to 380 rpm. Two sets of staggered kneading blocks were configured on the screw in this zone.

[0049] (2) Heating and premixing of auxiliary materials: 8 parts of polyether ester block copolymer, 0.3 parts of perfluorobutyl sulfonate, 0.5 parts of polymeric carbodiimide and 0.1 parts of tris(nonylphenol) phosphite were put into a low-speed mixer with a heating jacket. The heating temperature was set to maintain the material at 75°C. The mixture was stirred at low speed for 18 minutes to obtain the pretreated mixture.

[0050] (3) Side feeding mixing: The pre-treated mixture obtained in step (2) is quantitatively fed into the main melt through the twin-screw forced side feeder in zone 5 of the twin-screw extruder, and the barrel temperature in zone 5 is set to 260°C.

[0051] (4) Vacuum exhaust and cooling: When the material enters the 6th and 7th zones of the extruder, the vacuum pump at the exhaust port is turned on to maintain the vacuum degree of the section where the exhaust port is located at -0.092MPa. The vacuum degree is the gauge pressure value. According to the standard atmospheric pressure of 0.101MPa, the corresponding absolute pressure is about 0.009MPa. At the same time, the forced cooling water circulation is turned on in this section to make the barrel set temperature drop slowly to 252℃. The screw configuration in this section adopts a large lead conveying thread element.

[0052] (5) Extrusion quenching and pelletizing: The temperature of the 8th zone of the extruder and the die head is set to 252°C. The melt is extruded through the multi-hole die head to form a continuous strip, which is drawn into a 20°C circulating water tank for quenching and shaping. After the residual moisture on the surface is blown off by a high-pressure air knife, it enters the pelletizer to cut into slices. After drying, transparent PC carrier tape permanent protective material is obtained.

[0053] Example 4: This example provides a method for preparing a transparent PC carrier tape permanent protective material, specifically including the following steps: (1) Premixing and feeding of main materials: 90 parts of bisphenol A type polycarbonate resin, 1.5 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer and 0.2 parts of tris(2,4-di-tert-butylphenyl) phosphite were added to a high-speed mixer and mixed at room temperature for 3 minutes until uniform. Then the mixture was fed into the main feed port of a co-rotating parallel twin-screw extruder. The temperature of the first to fourth zones of the extruder was set to 265°C and the main screw speed was 350 rpm. Two sets of staggered kneading blocks were configured on the screw in this zone.

[0054] (2) Heating and premixing of auxiliary materials: 6.5 parts of polyether ester block copolymer, 0.2 parts of perfluorobutyl sulfonate potassium, 0.4 parts of polymeric carbodiimide and 0.1 parts of tris(nonylphenol) phosphite were put into a low-speed mixer with a heating jacket. The heating temperature was set to maintain the material at 70°C. The mixture was stirred at low speed for 15 minutes to obtain the pretreated mixture.

[0055] (3) Side feeding mixing: The pre-treated mixture obtained in step (2) is quantitatively fed into the main melt through the twin-screw forced side feeder in zone 5 of the twin-screw extruder, and the barrel temperature in zone 5 is set to 255°C.

[0056] (4) Vacuum exhaust and cooling: When the material enters the 6th and 7th zones of the extruder, the vacuum pump at the exhaust port is turned on to maintain the vacuum degree of the section where the exhaust port is located at -0.09MPa. The vacuum degree is the gauge pressure value. According to the standard atmospheric pressure of 0.101MPa, the corresponding absolute pressure is about 0.011MPa. At the same time, the forced cooling water circulation is turned on in this section to make the barrel set temperature drop slowly to 250℃. The screw configuration in this section adopts a large lead conveying thread element.

[0057] (5) Extrusion quenching and pelletizing: The temperature of the 8th zone of the extruder and the die head is set to 250°C. The melt is extruded through the multi-hole die head to form a continuous strip, which is drawn into a 15°C circulating water tank for quenching and shaping. After the residual moisture on the surface is blown off by a high-pressure air knife, it enters the pelletizer to cut into slices. After drying, transparent PC carrier tape permanent material is obtained.

[0058] Example 5: This example provides a method for preparing a transparent PC carrier tape permanent protective material, specifically including the following steps: (1) Premixing and feeding of main materials: 90 parts of bisphenol A type polycarbonate resin, 1.5 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer and 0.2 parts of tris(2,4-di-tert-butylphenyl) phosphite were added to a high-speed mixer and mixed at room temperature for 5 minutes until uniform. Then the mixture was fed into the main feed port of a co-rotating parallel twin-screw extruder. The temperature of the first to fourth zones of the extruder was set to 275°C and the main screw speed was 400 rpm. Three sets of staggered kneading blocks were configured on the screw in this zone.

[0059] (2) Heating and premixing of auxiliary materials: 6.5 parts of polyether ester block copolymer, 0.2 parts of perfluorobutyl sulfonate potassium, 0.4 parts of polymeric carbodiimide and 0.1 parts of tris(nonylphenol) phosphite were put into a low-speed mixer with a heating jacket. The heating temperature was set to maintain the material at 80°C and the mixture was stirred at low speed for 20 minutes to obtain a pretreated mixture.

[0060] (3) Side feeding mixing: The pre-treated mixture obtained in step (2) is quantitatively fed into the main melt through the twin-screw forced side feeder in zone 5 of the twin-screw extruder, and the barrel temperature in zone 5 is set to 265°C.

[0061] (4) Vacuum exhaust and cooling: When the material enters the 6th and 7th zones of the extruder, the vacuum pump at the exhaust port is turned on to maintain the vacuum degree of the section where the exhaust port is located at -0.095MPa. The vacuum degree is the gauge pressure value. According to the standard atmospheric pressure of 0.101MPa, the corresponding absolute pressure is about 0.006MPa. At the same time, the forced cooling water circulation is turned on in this section to make the barrel set temperature drop slowly to 255℃. The screw configuration in this section adopts a large lead conveying thread element.

[0062] (5) Extrusion quenching and pelletizing: The temperature of the 8th zone of the extruder and the die head is set to 255°C. The melt is extruded through the multi-hole die head to form a continuous strip, which is drawn into a 25°C circulating water tank for quenching and shaping. After the residual moisture on the surface is blown off by a high-pressure air knife, it enters the pelletizer to cut into slices. After drying, transparent PC carrier tape permanent material is obtained.

[0063] Comparative Example 1: Compared with Example 1, the difference is that potassium perfluorobutyl sulfonate was not added in this comparative example, and it was made up with an equal part by weight of bisphenol A type polycarbonate resin, that is, the amount of bisphenol A type polycarbonate resin was adjusted to 90.2 parts, so that the total weight of the formulation is consistent with that of Example 1. Apart from the above differences, the amount of other components and the preparation process conditions are the same.

[0064] Comparative Example 2: Compared with Example 1, the difference is that no polymeric carbodiimide was added in this comparative example, and it was made up with an equal weight of bisphenol A type polycarbonate resin, that is, the amount of bisphenol A type polycarbonate resin was adjusted to 90.4 parts, so that the total weight of the formulation is consistent with that of Example 1. Apart from the above differences, the amount of other components and the preparation process conditions are the same.

[0065] Comparative Example 3: Compared with Example 1, the difference is that this comparative example does not add ethylene-methyl acrylate-glycidyl methacrylate terpolymer, but makes up the difference with an equal part by weight of bisphenol A type polycarbonate resin, that is, the amount of bisphenol A type polycarbonate resin is adjusted to 91.5 parts, so that the total weight of the formulation is consistent with that of Example 1. Apart from the above differences, the amount of other components and the preparation process conditions are the same.

[0066] Comparative Example 4: Compared with Example 1, the difference lies in the order of feeding materials in this comparative example. Specifically, the bisphenol A type polycarbonate resin, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, tris(2,4-di-tert-butylphenyl) phosphite, polyether ester block copolymer, potassium perfluorobutyl sulfonate, polymeric carbodiimide, and tris(nonylphenol) phosphite are mixed uniformly at room temperature in one go and then fed into the main feed port of the extruder. The side feeding process is not used. Except for the above differences, the dosage of other components and the preparation process conditions are the same.

[0067] Comparative Example 5: Compared with Example 1, the difference lies in the exhaust and cooling process of the latter stage in this comparative example. Specifically, when the material is in Zone 6 and Zone 7 of the extruder, the exhaust port vacuum pump is not turned on (it is under normal pressure), and the forced cooling water circulation is not turned on to cool it down (the barrel temperature in Zone 6 and Zone 7 is maintained at 260°C). Apart from the above differences, the dosage of other components and the preparation process conditions are the same.

[0068] Test Example 1: The experimental steps are as follows: (1) Weigh 5.0 g each of the material particles from Example 1, the material particles from Comparative Example 3, and the physically mixed reference powder, and place them in a vacuum drying oven. Dry them at 80°C for 12 hours to reduce the influence of adsorbed moisture in the samples on the test results. After drying, each sample was cryogenically pulverized with liquid nitrogen to obtain test powders with similar particle sizes. Considering that dichloromethane may have a dissolving or swelling effect on the polycarbonate matrix, this test uses the attenuated total reflectance mode of Fourier transform infrared spectroscopy to directly test each sample to obtain the changes in the relative absorption intensity of characteristic groups.

[0069] (2) Place the above test powders on the ATR accessory of the Fourier transform infrared spectrometer for testing, and test at least 3 different sampling points for each sample. The polycarbonate groups are located at approximately 1775 cm⁻¹. -1 The characteristic absorption peak at 910 cm⁻¹ was used as an internal standard peak. -1 Characteristic peak of epoxy group at 2130 cm⁻¹ -1 Characteristic peaks of the carbodiimide group and 1650 cm⁻¹ -1 The absorbance of the characteristic peaks containing urea structures was normalized. The infrared measurement scan range was 4000 cm⁻¹. -1 Up to 400cm -1 The resolution is 4cm. -1 The number of scans was 32.

[0070] (2) The dynamic rheological properties of the materials were tested using a rotational rheometer. The material particles from Example 1 and Comparative Example 3 were injection molded into discs with a diameter of 25 mm and a thickness of 1.5 mm, respectively. The physically mixed reference powder was rapidly hot-pressed into discs with a diameter of 25 mm and a thickness of 1.5 mm at 260°C under nitrogen protection. The hot-pressing time was controlled within 2 minutes to reduce the influence of the sample preparation process on the reaction state of the physically mixed reference powder. The rheometer was equipped with a 25 mm parallel plate fixture, the test temperature was 260°C, the strain amplitude was 1%, and the angular frequency scan range was 0.1 rad / s to 100 rad / s. The complex viscosity at different angular frequencies was recorded, and the complex viscosity at 0.1 rad / s was extracted for comparative analysis.

[0071] .

[0072] Based on the data in Table 1 and the appendix Figure 1 It can be seen that, compared with the physically mixed reference powder, the 910cm in the material of Example 1 -1 Characteristic peaks of epoxy groups and 2130 cm⁻¹ -1The normalized absorption intensities of the characteristic peaks of the carbodiimide group at 1650 cm⁻¹ all decreased significantly. -1 The normalized absorption intensity of the characteristic peak of the urea-containing structure increased accordingly. These results indicate that after twin-screw extrusion processing, the characteristic absorption peaks of the epoxy group-containing component and the carbodiimide component in Example 1 changed, suggesting that processes such as epoxy group ring-opening reaction, carbodiimide consumption, and urea-containing structure formation may have occurred during processing. Considering the structural characteristics of each component, this change is consistent with the judgment that a certain degree of grafting, coupling, or micro-crosslinking reaction occurred at the interface.

[0073] Based on the dynamic rheological test results, the complex viscosity of the material in Example 1 at 0.1 rad / s is 8145.6 Pa·s, which is higher than that of the material in Comparative Example 3 and the physically mixed reference powder. Low-frequency complex viscosity is generally related to polymer chain relaxation, molecular chain entanglement, and interfacial interactions of the dispersed phases. The increased low-frequency complex viscosity of the material in Example 1 indicates that its melt has a stronger viscoelastic response in the low-frequency region. This phenomenon is consistent with the judgment that the system exhibits enhanced interfacial interactions, restricted molecular chain motion, or the formation of local network structures.

[0074] Although the material in Comparative Example 3 is at 1650cm -1 A certain intensity of urea-containing structural characteristic peaks was detected, but its complex viscosity at 0.1 rad / s was significantly lower than that of the material in Example 1. This result indicates that, even without the addition of the ethylene-methyl acrylate-glycidyl methacrylate terpolymer, the interfacial interactions and low-frequency viscoelastic response of the system are still weaker than those of the material in Example 1, even with a certain degree of carbodiimide-related reaction. These results, based on both the changes in infrared characteristic peaks and the low-frequency rheological response, support the conclusion that a strong interfacial interaction and local network structure exist in the system of Example 1.

[0075] Test Example 2: The experimental steps are as follows: (1) Weigh 0.15 g each of bisphenol A type polycarbonate resin raw material, material particles of Example 1 and material particles of Comparative Example 2, and place them into glass sample bottles containing 15 mL of chromatographic grade tetrahydrofuran. Place them on a shaker at room temperature and shake to dissolve for 12 hours. After dissolution, filter the sample solution using a polytetrafluoroethylene microporous membrane with a pore size of 0.22 μm to remove any undissolved components or particles. Collect the filtrate for later use.

[0076] (2) The above filtrate was tested using a gel permeation chromatograph equipped with a differential refractive index detector. The mobile phase of the test system was tetrahydrofuran, the injection volume was 50 μL, the elution flow rate was 1.0 mL / min, and the column and detector temperatures were both set to 35 °C.

[0077] (3) A calibration curve was plotted using narrow-distribution polystyrene standards. The relative number-average molecular weight and relative weight-average molecular weight of each sample were calculated based on the standard curve and elution time. The molecular weight distribution index was also calculated.

[0078] .

[0079] Based on the data in Table 2 and the appendix Figure 2 It can be seen that the relative weight-average molecular weight of the unprocessed polycarbonate raw material is 28741 g / mol, and the molecular weight distribution index is 2.02. After processing by twin-screw extrusion, the relative weight-average molecular weight of the polycarbonate matrix of the material in Example 1 is 27318 g / mol, and the molecular weight distribution index is 2.03. Compared with the polycarbonate raw material, the relative weight-average molecular weight of the material in Example 1 only decreased slightly, and the molecular weight distribution index did not increase significantly, indicating that it still maintained a good molecular weight level after processing.

[0080] Comparative Example 2, without the addition of polymeric carbodiimide, showed a decrease in relative weight-average molecular weight to 16489 g / mol, a decrease in relative number-average molecular weight to 6734 g / mol, and an increase in molecular weight distribution index to 2.45. These results indicate that the molecular weight of the polycarbonate matrix in Comparative Example 2 decreased significantly after processing, and the molecular weight distribution broadened, suggesting an increase in the proportion of low molecular weight components in the system.

[0081] In blends containing potassium perfluorobutylsulfonate, potassium ions or strongly polar ion pairs may promote the exchange, hydrolysis, alcoholysis, or chain scission of carbonate bonds in the polycarbonate backbone under high-temperature melt processing conditions. The significant decrease in molecular weight in Comparative Example 2 is consistent with the conclusion that the system's resistance to degradation decreases after the absence of polymeric carbodiimide.

[0082] The material in Example 1 maintained a high relative molecular weight, indicating that the addition of polymeric carbodiimide helps improve the molecular weight retention of the polycarbonate matrix during processing. Considering the potential reaction of polymeric carbodiimide with trace amounts of moisture, end groups, or components at the dispersed phase interface, the above results support its role in reducing the influence of moisture or active end groups and slowing down the decrease in the molecular weight of the polycarbonate matrix. These test results, from the perspective of molecular weight change, support the good processing stability of the system of this invention.

[0083] Test Example 3: The experimental steps are as follows: (1) Cut test samples from the center area of ​​the injection molded specimens of pure bisphenol A type polycarbonate resin and each example and comparative example. Weigh 6.5 mg to 7.5 mg of the sample using a micro balance with an accuracy of 0.01 mg, place it in a standard aluminum crucible and seal it.

[0084] (2) Differential scanning calorimetry (DSC) was used for thermal analysis. The entire test was conducted under high-purity nitrogen protection, with the nitrogen purging flow rate set to 50 mL / min. The heating and cooling program was set as follows: First, the sample was heated from room temperature to 280°C at a rate of 10°C / min and held at 280°C for 5 minutes to eliminate the processing thermal history of the sample as much as possible; then, it was cooled to room temperature at a rate of 10°C / min, and the exothermic crystallization curve during the cooling process was recorded, and the crystallization temperature Tc of the polyether ester block copolymer dispersed phase was extracted; after cooling, it was heated to 280°C again at a rate of 10°C / min, and the second heating curve was recorded, and the glass transition temperature Tg of the polycarbonate continuous phase and the melting temperature Tm of the polyether ester block copolymer dispersed phase were extracted.

[0085] (3) The sample was then cooled to room temperature at a rate of 10 °C / min. The exothermic crystallization curve of the cooling process was recorded, and the crystallization temperature of the dispersed polyether ester block copolymer was extracted. After cooling, the sample was heated to 280 °C again at a rate of 10 °C / min. The second heating curve was recorded, and the glass transition temperature of the polycarbonate continuous phase and the melting temperature of the dispersed phase were extracted.

[0086] .

[0087] Based on the data in Table 3 and Figure 3 It is known that the glass transition temperature of pure polycarbonate resin is 148.5℃. The material in Comparative Example 3, without the addition of the ethylene-methyl acrylate-glycidyl methacrylate terpolymer, has a polycarbonate phase glass transition temperature of 146.8℃, and its polyether ester phase crystallization and melting temperatures are 113.2℃ and 156.4℃, respectively. The polycarbonate phase glass transition temperature of the material in Example 1 decreased to 142.3℃, while its polyether ester phase crystallization and melting temperatures decreased to 104.7℃ and 150.1℃, respectively.

[0088] Generally, changes in the glass transition temperature, crystallization temperature, and melting temperature of polymer blends are usually related to changes in inter-component interactions, chain segment mobility, and dispersed phase crystallization behavior. In Example 1, the glass transition temperature of the polycarbonate phase shifts towards lower temperatures, indicating a change in the chain segment mobility state within the system compared to Comparative Example 3. Combined with the aforementioned infrared and rheological test results, this change is consistent with the conclusion that interfacial interactions are enhanced and inter-component compatibility is improved in the system of Example 1.

[0089] Furthermore, the crystallization and melting temperatures of the polyether ester phase in Example 1 were lower than those in Comparative Example 3 and Comparative Example 4, indicating that the crystallization behavior of the polyether ester dispersed phase was affected to some extent. This phenomenon suggests that the regular arrangement of polyether ester segments and the crystallization process in the Example 1 system may be interfered with by the interfacial structure or interfacial interactions. Due to changes in the feeding sequence and process conditions, Comparative Example 4 exhibited a characteristic thermal transition temperature closer to that of Comparative Example 3. These results support the conclusion that a strong interfacial interaction exists in the Example 1 system, demonstrating a certain trend towards improved compatibility.

[0090] Test Example 4: The experimental steps are as follows: (1) Pure bisphenol A type polycarbonate resin and the material particles prepared in each example and comparative example were placed in a forced-air drying oven and dried at 120°C for 4 hours. Then, an optical test sample with a size of 50mm×50mm and a thickness of 2.0mm was prepared by injection molding machine. The barrel temperature was set to 280°C and the mold temperature was set to 80°C during injection molding.

[0091] (2) Place the injection-molded test sample in a standard environment with a temperature of 23±2℃ and a relative humidity of 50±5% for 48 hours. Before the test, wipe the surface of the sample with a lint-free cloth dampened with a small amount of isopropyl alcohol to remove dust or other residues adhering to the surface.

[0092] (3) The transmittance and haze of the test samples were determined using an integrating sphere haze meter according to ASTM D1003 standard. During testing, the sample was placed close to the instrument's test window, and a standard C light source was used for measurement. Five independent samples were prepared for each formulation, and the transmittance and haze data were recorded at five locations on each sample, including the central area and the four corners. Data points with obvious abnormalities were removed after verification; the final result was the arithmetic mean of the valid test data, and the standard deviation was recorded.

[0093] .

[0094] According to the data in Table 4, the transmittance of pure polycarbonate resin was 89.6%, and the haze was 0.8%. The transmittance of the materials in Examples 1 to 5 ranged from 85.9% to 87.2%, and the haze ranged from 1.8% to 2.5%. Compared with pure polycarbonate resin, the transmittance of the materials in each example decreased and the haze increased, but overall they still exhibited high transmittance and low haze. The transmittance of the material in Comparative Example 3 was 74.3%, and the haze was 18.6%; the transmittance of the material in Comparative Example 5 was 78.5%, and the haze was 12.4%.

[0095] Generally speaking, the transmittance and haze of a multi-component polymer blend system are related to factors such as the difference in refractive index between the components, the size of the dispersed phase, and its distribution. When the size of the dispersed phase increases or there are more interfacial defects in the system, the scattering of incident light by the material usually increases, resulting in a decrease in transmittance and an increase in haze.

[0096] Comparative Example 3, without the addition of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, exhibited significantly lower light transmittance and a markedly higher haze than the materials in the examples, indicating a higher degree of light scattering in its system. Comparative Example 5, without vacuuming and subsequent cooling treatment, also showed significantly lower light transmittance and haze than the materials in the examples, suggesting that changes in processing conditions may adversely affect the optical properties of the materials.

[0097] The materials in Examples 1 to 5 all maintained high light transmittance and low haze, indicating that under the formulation and process conditions of this invention, the materials can maintain good optical transparency after the introduction of polyether ester block copolymers and other components. Based on the aforementioned test results, it can be concluded that the addition of the terpolymer and the corresponding processing conditions help improve the interfacial state of the system and have a positive effect on reducing light scattering.

[0098] Test Example 5: The experimental steps are as follows: (1) Place each group of test objects in a vacuum drying oven at 110℃ and dry for 6 hours. Use an injection molding machine to inject the dried granules into square test specimens with a size of 100mm×100mm and a thickness of 3.0mm.

[0099] (2) The injection-molded samples were conditioned for 48 hours in a constant temperature and humidity environment of 23±2℃ and 50±5% relative humidity. The initial surface resistivity of the samples was measured using a high-resistivity meter equipped with concentric ring electrodes according to ASTM D257 standard. A DC voltage of 500V was applied during the test, and the value was read after 60 seconds. Five samples were tested for each formulation, and the geometric mean was calculated and recorded as the initial surface resistivity.

[0100] (3) Subsequently, a water washing retention test was conducted. The sample that had completed the initial test was immersed in an ultrasonic cleaning tank containing deionized water and ultrasonically cleaned for 30 minutes at room temperature. After removing the sample, the surface residual moisture was dried using compressed nitrogen.

[0101] (4) After drying, the sample was placed again in a constant temperature and humidity environment of 23±2℃ and 50±5% for 48 hours. After the conditioning was completed, the surface resistivity was measured near the original test area of ​​the sample using the same instrument and test conditions. The geometric mean was calculated and recorded as the surface resistivity after water washing.

[0102] .

[0103] According to the data in Table 5, the initial surface resistivity of pure polycarbonate resin is 1.58 × 10⁻⁶. 15 Ω / sq, surface resistivity after water washing is 2.13×10 Ω / sq. 15 Ω / sq. Comparative Example 1, without the addition of potassium perfluorobutyl sulfonate, had an initial surface resistivity and a surface resistivity after water washing of 6.23 × 10⁻⁶ Ω / sq. 12 Ω / sq and 7.48×10 12 Ω / sq. Comparative Example 4 changed the feeding and pretreatment methods, and its initial surface resistivity and surface resistivity after water washing were 8.74×10 Ω / sq. 10 Ω / sq and 1.15×10 11 Ω / sq. The initial surface resistivity of the materials in Examples 1 to 5 is 2.56 × 10⁻⁶ Ω / sq. 8 Ω / sq up to 8.35×10 8 Ω / sq, surface resistivity after water washing is 3.02×10 Ω / sq. 8 Ω / sq up to 9.41×10 8 Ω / sq.

[0104] The above results indicate that the materials of Examples 1 to 5 have lower surface resistivity compared to pure polycarbonate resin, Comparative Example 1, and Comparative Example 4. After ultrasonic cleaning with deionized water, the surface resistivity of the materials of Examples 1 to 5 only changed slightly and did not increase by an order of magnitude, indicating that their antistatic properties are well maintained after water washing.

[0105] Comparative Example 1, without the addition of potassium perfluorobutyl sulfonate, exhibited a significantly higher surface resistivity than the examples, indicating that the addition of potassium perfluorobutyl sulfonate helps reduce the surface resistivity of the material in this system. Although Comparative Example 4 contained potassium perfluorobutyl sulfonate and a polyether ester block copolymer, its surface resistivity remained significantly higher than the examples due to changes in its feeding and pretreatment methods, suggesting that the side-feeding and pretreatment processes have a certain impact on the formation of antistatic properties.

[0106] In the system of this invention, the polyether ester block copolymer provides a favorable phase environment for ion conduction, and potassium perfluorobutyl sulfonate provides an ionicly conductive component. The surface resistivity of the materials in the examples is at a low level and remains within the same order of magnitude after washing, indicating that the above components and processing methods contribute to the formation of a relatively stable antistatic system. Combined with the aforementioned infrared, rheological, and molecular weight test results, it can be considered that the polymeric carbodiimide may participate in the interfacial reaction and inhibit the migration of ionic components, thereby helping to improve the retention of the material's antistatic properties.

[0107] Test Example 6: The experimental steps are as follows: (1) The fully dried pure bisphenol A type polycarbonate resin and the granules of each example and comparative example were injection molded into optical colorimetric test samples with a size of 60mm×60mm and a thickness of 3.0mm using a precision injection molding machine. After injection molding, the samples were placed in a light-proof environment with a temperature of 23±2℃ for 24 hours.

[0108] (2) According to ASTM E313 standard, the initial yellowness index (YI) of each sample was determined in transmission mode using a spectrophotometer equipped with a transmission test accessory. Before testing, zero-point calibration and 100% transmittance calibration were performed using the instrument's transmission calibration accessory. A D65 standard light source and a 10° field of view were selected. Five independent samples of each formulation were tested, and the readings in the central area were taken and the arithmetic mean was calculated, which was recorded as the initial yellowness index.

[0109] (3) The samples that have completed the initial test are suspended in the forced convection hot air aging test chamber and aged at 120°C for 168 hours. Sufficient spacing is maintained between the samples to ensure uniform hot air circulation in the chamber.

[0110] (4) After aging, the sample was removed and cooled in a dark environment at room temperature for 24 hours. Using the same colorimeter, transmission test mode and measurement conditions, the yellowness index after aging was measured in the original test area, and the difference in yellowness index before and after aging (ΔYI) was calculated to characterize the degree of yellowing of the material.

[0111] .

[0112] According to the data in Table 6, the initial yellowness index of pure polycarbonate resin was 1.25. After aging in hot air at 120°C for 168 hours, the yellowness index increased to 2.87, and the ΔYI was 1.62. The initial yellowness indices of the materials in Examples 1 to 5 were 2.18 to 2.51, and the yellowness indices after aging were 3.96 to 4.39, with ΔYI ranging from 1.78 to 1.88. The initial yellowness index of Comparative Example 2 was 8.76, and the yellowness index after aging increased to 21.43, with ΔYI reaching 12.67.

[0113] As can be seen from the above results, the changes in yellowness index before and after aging in Examples 1 to 5 are relatively similar, and there is no significant abnormal increase compared with pure polycarbonate resin; while the initial yellowness index and the yellowness index after aging in Comparative Example 2 are significantly higher than those in Examples 1 to 5, and its ΔYI is significantly increased, indicating that the color stability of this formulation system is relatively poor under the test conditions.

[0114] Under normal circumstances, polycarbonate materials may undergo a certain degree of thermo-oxidative aging under high-temperature and aerobic conditions, accompanied by an increase in the yellowness index. Based on the aforementioned molecular weight test and other performance test results of this application, it can be inferred that in Comparative Example 2, due to the absence of polymeric carbodiimide, the stabilizing effect on the polycarbonate matrix during processing and subsequent aging is relatively insufficient, thus making it more prone to a significant increase in the yellowness index.

[0115] In contrast, the changes in yellowness index in Examples 1 to 5 were smaller, indicating that the formulation and process conditions used in the embodiments of the present invention help improve the color stability of the material under hot air aging conditions. Based on the aforementioned test results, it is speculated that the polymeric carbodiimide may have participated in the interfacial reaction in the system and had a certain inhibitory effect on the migration of ionic components to the polycarbonate continuous phase, thereby mitigating the color degradation trend of the continuous phase matrix during processing and aging to a certain extent.

[0116] Test Example 7: The experimental steps are as follows: (1) The pure bisphenol A type polycarbonate resin and the material particles of each example and comparative example were placed in a 120°C forced-air drying oven and dried for 4 hours to remove moisture.

[0117] (2) The dried granules were injection molded into Type I dumbbell-shaped tensile test specimens conforming to ASTM D638 and rectangular cantilever beam notched impact test specimens conforming to ASTM D256 using an injection molding machine. During the injection molding process, the barrel temperature was set to 265℃ to 280℃ and the mold temperature was controlled at 80℃.

[0118] (3) Place the injection-molded test specimen in a standard environment with a temperature of 23±2℃ and a relative humidity of 50±5% for 48 hours.

[0119] (4) The tensile yield strength of dumbbell-shaped tensile specimens was tested using a computer-controlled electronic universal testing machine. Following ASTM D638, the tensile speed was set to 50 mm / min, and the stress changes during the tensile process were recorded to obtain the tensile yield strength data of the material. Five independent specimens were tested for each formulation, and the arithmetic mean was taken as the test result.

[0120] (5) The impact strength of rectangular test specimens was tested using a cantilever beam notched impact testing machine. A V-shaped notch was machined in the middle of the specimen using a standard notching machine according to ASTM D256, with a bottom radius of 0.25 mm. A pendulum was used to impact the notched area, and the impact energy absorbed when the material fractured was recorded and converted into the cantilever beam notched impact strength. Five independent specimens were tested for each formulation, and the arithmetic mean was taken as the test result.

[0121] .

[0122] According to the data in Table 7, the tensile yield strength of pure polycarbonate resin is 61.2 MPa, and the notched impact strength of the cantilever beam is 785.4 J / m. The tensile yield strength of the materials in Examples 1 to 5 ranges from 57.6 MPa to 59.4 MPa, which is slightly lower than that of pure polycarbonate resin; the notched impact strength of the cantilever beam ranges from 798.1 J / m to 824.6 J / m, which is higher than that of pure polycarbonate resin. The tensile yield strength of Comparative Example 2 is 41.3 MPa, and the notched impact strength of the cantilever beam is 162.8 J / m, both of which are significantly lower than those of the materials in the examples and pure polycarbonate resin.

[0123] The above results indicate that, under the formulation and process conditions corresponding to the embodiments of this application, the material can improve the impact performance to a certain extent while basically maintaining the strength level of the polycarbonate matrix. Comparative Example 2, without the addition of polymeric carbodiimide, showed a more significant decrease in mechanical properties. This result is consistent with the test results showing a decrease in the molecular weight of its matrix, indicating that this component may play a role in maintaining the mechanical properties of the material.

[0124] Based on the aforementioned test results, polymeric carbodiimide may participate in interfacial reactions during processing and exert a certain inhibitory effect on ion migration and polycarbonate matrix degradation, thereby helping to mitigate the deterioration of the material's mechanical properties. Furthermore, the ethylene-methyl acrylate-glycidyl methacrylate terpolymer may improve the interfacial bonding between the continuous and dispersed phases, allowing the polyether ester block copolymer dispersed phase to not only perform antistatic functions but also, to a certain extent, play a role in stress transfer and energy dissipation. Therefore, the materials in the examples exhibited improved impact strength while only slightly decreasing tensile yield strength.

[0125] Based on the data in Table 7, it can be concluded that the component combination and process conditions in the embodiments of this application have a positive effect on maintaining the comprehensive mechanical properties of the material.

[0126] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A transparent PC carrier tape permanent protective material, characterized in that, Made from the following ingredients in parts by weight: Bisphenol A type polycarbonate resin: 88-92 parts; Ethylene-methyl acrylate-glycidyl methacrylate terpolymer: 1-2 parts; Polyether ester block copolymer: 5-8 parts; Potassium perfluorobutyl sulfonate: 0.1–0.3 parts; Polymerized carbodiimide: 0.3–0.5 parts; Antioxidant composition: 0.2 to 0.4 parts.

2. The transparent PC carrier tape permanent protective material according to claim 1, characterized in that, Made from the following ingredients in parts by weight: Bisphenol A type polycarbonate resin: 89-91 parts; Ethylene-methyl acrylate-glycidyl methacrylate terpolymer: 1.2–1.8 parts; Polyether ester block copolymer: 6-7 parts; Potassium perfluorobutyl sulfonate: 0.15–0.25 parts; Polymerized carbodiimide: 0.35–0.45 parts; Antioxidant composition: 0.25 to 0.35 parts.

3. The transparent PC carrier tape permanent protective material according to claim 1, characterized in that, The antioxidant composition consists of tris(2,4-di-tert-butylphenyl) phosphite and tris(nonylphenol) phosphite, with a weight ratio of 1.5:1 to 2.5:

1.

4. The transparent PC carrier tape permanent protective material according to claim 1, characterized in that, The polyether ester block copolymer is a block copolymer composed of alternating links of polybutylene terephthalate as hard segments and polytetrahydrofuran ether as soft segments.

5. The transparent PC carrier tape permanent protective material according to claim 1, characterized in that, The bisphenol A type polycarbonate resin has a melt flow rate of 10-15 g / 10 min under test conditions of 300℃ and 1.2 kg; the mass fraction of glycidyl methacrylate monomer in the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is 6%-10%.

6. A method for preparing a transparent PC carrier tape permanent protective material according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Bisphenol A type polycarbonate resin, ethylene-methyl acrylate-glycidyl methacrylate terpolymer and part of antioxidant composition are added to a mixer and mixed evenly. Then, the mixture is fed into the main feed port of a twin-screw extruder for melt extrusion. S2. The polyether ester block copolymer, potassium perfluorobutyl sulfonate, polymeric carbodiimide and the remaining antioxidant composition are put into a mixer with a heating jacket for low-speed hot mixing to obtain a pretreated mixture. S3. The pretreated mixture obtained in S2 is quantitatively fed into the main melt through the forced side feeder downstream of the twin-screw extruder; S4. The material continues to enter the downstream section of the extruder. In this section, vacuum exhaust is activated to remove low molecular weight volatiles, and forced cooling circulation is activated simultaneously to cool the melt and increase its viscosity. S5. The melt is extruded through the die head to form a strip. After being rapidly cooled and shaped in a water bath and the surface moisture is dried, it is cut into pellets and dried to obtain transparent PC carrier tape permanent protective material.

7. The method for preparing a transparent PC carrier tape permanent protective material according to claim 6, characterized in that, In S1, the mixing is carried out at room temperature for 3 to 5 minutes; the set temperature of the first to fourth zones of the twin-screw extruder is 265 to 275°C, the main screw speed is 350 to 400 rpm, and the screw in this zone is equipped with two to three sets of staggered kneading blocks.

8. The method for preparing a transparent PC carrier tape permanent protective material according to claim 6, characterized in that, In S2, the temperature of the mixer with the heating jacket is set to maintain the material at 70-80℃, and the low-speed mixing time is 15-20 minutes.

9. The method for preparing a transparent PC carrier tape permanent protective material according to claim 6, characterized in that, In S3, the forced side feeder is located in zone 5 of the twin-screw extruder, and the barrel temperature of this zone is set to 255-265°C.

10. The method for preparing a transparent PC carrier tape permanent protective material according to claim 6, characterized in that, In S4, the vacuum gauge pressure of the section where the exhaust port is located is maintained at -0.09MPa to -0.095MPa, while the barrel setting temperature of this section is gradually reduced to 250 to 255℃ through forced cooling water circulation; in S5, the setting temperature of the 8th zone of the extruder and the die head is 250 to 255℃, and the temperature of the circulating water in the water tank is 15 to 25℃.

Images