High-fluidity polyolefin / polyester master batch as well as preparation method and application thereof

Abstract

The high-fluidity polyolefin / polyester master batch comprises the following components in percentage by weight: 15-50% of polyolefin resin, 27-78% of polyester resin, 5-15% of modified inorganic particles, 1-5% of a toughening agent and 1-3% of a dispersing agent. The polyolefin / polyester master batch prepared by the invention not only has good flowability and is easy for continuous granulation production, but also does not reduce other properties of the reflective film when being added into the white reflective film.

Description

Technical Field

[0001] The present invention relates to a polyester masterbatch, in particular to a high-fluidity polyolefin / polyester masterbatch and a preparation method and application thereof. Background Art

[0002] As an important component in LCD displays, reflective film is generally placed at the bottom layer of the backlight module. It reflects the LED lamp beads or the light that is not directly utilized through the bottom or periphery of the light guide plate back to the front of the screen, thereby reducing the overall light loss in the process and improving the effective brightness of the display. Reflective film for LCD displays generally uses pores formed during the biaxial stretching process of incompatible resins (usually polyolefins) and PET polyester to provide sufficient reflective interfaces. Due to the large differences in polarity and melt index between polyolefins and PET polyester, it is very easy to break the film and the pores in the film are too large and unevenly distributed when the polyolefin and PET are simply mixed and melt-extruded. This is not conducive to the performance improvement and normal production of the reflective film. Therefore, it is usually necessary to use a twin-screw extruder to make polyolefin / PET masterbatch in advance from polyolefin and PET polyester. However, in the masterbatch preparation process, polyolefins and PET polyester are incompatible. After melt mixing, the melt strength of the mixture is low and the fluidity is poor. After being extruded through the extruder die, the Barus effect (when the polymer melt is extruded from the orifice, the melt swells at the orifice, so it is also called the orifice swell effect) is likely to occur. The material strips before entering the underwater cooling are very easy to break during the process of being pulled by the pelletizer, making it difficult to carry out continuous masterbatch production.

[0003] Currently, to address the challenges of continuous pelletizing of these masterbatches, a toughening agent is often added to the masterbatch formulation to increase the melt strength of the mixture and reduce the likelihood of strand breakage during the pelletizing process. However, excessive amounts of toughening agent can increase the difficulty of subsequent film stretching, reduce the effectiveness of the phase separation pore formation process (pore size and density within the film), and increase the cost of the film's raw materials.

[0004] Therefore, how to improve the flow properties of polyolefin / polyester masterbatch during the granulation production process so that it can enter the underwater cooling link in a shorter time, reduce the probability of material strip breakage, and achieve long-cycle continuous granulation production will directly affect the performance and production cost of such polyolefin / polyester masterbatch and the reflective film produced using such masterbatch. Summary of the Invention

[0005] In order to overcome the drawbacks of the prior art, the present invention provides a high-fluidity polyolefin / polyester masterbatch and a preparation method thereof. The prepared polyolefin / polyester masterbatch not only has good fluidity and is easy to be continuously granulated, but also can be added to a white reflective film without reducing other properties of the reflective film.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] A high-flow polyolefin / polyester masterbatch, comprising the following components in percentage by weight:

[0008]

[0009] The modified inorganic particles of the high-fluidity polyolefin / polyester masterbatch are nano-titanium dioxide particles that have been simultaneously modified by surface coating with aluminum oxide and surface wetting with a silane coupling agent, and have an average particle size of 200 to 500 nm.

[0010] The high-fluidity polyolefin / polyester masterbatch, the polyolefin resin includes one or more of polymethylpentene, polypropylene, and cycloolefin copolymer; the melt index of the polyolefin resin is 25-80 g / 10 min, and the test conditions are 260° C. and 5 kg.

[0011] The high-fluidity polyolefin / polyester masterbatch, wherein the polyester resin is polyethylene terephthalate chips, has an intrinsic viscosity of 0.68 to 1.0 dL / g.

[0012] The high-fluidity polyolefin / polyester masterbatch, the toughening agent is a composition of POE grafted GMA and amorphous copolyester, and the weight ratio of the POE grafted GMA to the amorphous copolyester is 1: (1-2).

[0013] The high-fluidity polyolefin / polyester masterbatch, the amorphous copolyester is PETG resin.

[0014] The high-fluidity polyolefin / polyester masterbatch mentioned above, the dispersant includes one or more of polyethylene glycol, polyethylene wax, and polypropylene wax.

[0015] A method for preparing high-flow polyolefin / polyester masterbatch, the preparation method comprising the following steps:

[0016] a. Grinding the polyolefin resin and toughening agent separately by a pulverizer to obtain a powder mixture F1;

[0017] b. Mixing the powder mixture F1 obtained in step a with a compatibilizer and modified inorganic particles in a high-speed mixer to obtain a powder mixture F2;

[0018] c. The polyester resin and the powder mixture F2 obtained in step b are added to a twin-screw extruder through a loss-in-weight scale, and are fully mixed, plasticized, and melted to obtain a molten mixture;

[0019] d. The molten mixture obtained in step c is filtered, extruded through a die, cooled underwater, pelletized by a pelletizer, and dried to obtain a high-flowability polyolefin / polyester masterbatch.

[0020] The above-mentioned method for preparing high-flow polyolefin / polyester masterbatch, in step c, the temperature of each zone of the twin-screw extruder is 250-270°C, the screw speed is 200-300r / min, the vacuum degree is -0.08-0.04MPa, the filter mesh pore size is 40μm, the water tank temperature is 15-25°C, and the hot air drying temperature is 100-160°C.

[0021] An application of a high-flowability polyolefin / polyester masterbatch. The high-flowability polyolefin / polyester masterbatch obtained by any one of claims 1 to 9 is suitable for use in white polyester film. The high-flowability polyolefin / polyester masterbatch and polyester resin are mixed, melt-extruded, and biaxially stretched to prepare the white polyester film.

[0022] The beneficial effects of the present invention are:

[0023] (1) The addition of modified inorganic particles can provide a large number of nucleation cores, greatly increase the flow rate of polyolefin / PET resin, and reduce the phenomenon that the mixture melt is easily broken during the traction process of the pelletizer after being extruded through the extruder die due to poor fluidity, thereby facilitating continuous masterbatch production;

[0024] (2) The addition of modified inorganic particles that have been modified by surface coating with alumina and surface wetting with a silane coupling agent can utilize a large number of particles to be dispersed in the mixture melt, acting as "nodes" connecting the two incompatible resins, polyolefin resin and polyester resin, effectively increasing the dispersion uniformity of polyolefin resin in polyester resin, and helping to form a uniform, dense, and small interface separation phenomenon between polyolefin resin and polyester resin during subsequent melt extrusion and biaxial stretching, thereby improving the foaming effect inside the white polyester reflective film (the pore size and density of the pores in the film) and improving the reflective efficiency of the white reflective film;

[0025] (3) The modified inorganic particles are added simultaneously during the polyolefin / polyester masterbatch granulation stage. The separate addition of titanium dioxide masterbatch can be removed or reduced in the later white polyester film production process. Since part of the titanium dioxide granulation process is reduced, the cost of the final white polyester film can be effectively reduced and the production process can be simplified. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a state diagram of the die during the preparation process of the masterbatch prepared in Example 5 of the present invention and Comparative Example 2.

[0027] The left picture is Example 5, and the right picture is Comparative Example 2. DETAILED DESCRIPTION

[0028] The masterbatch of the present invention comprises modified inorganic particles, which are modified by coating the surface of aluminum oxide and impregnating the surface of a silane coupling agent. The silane coupling agent is γ-aminopropyltriethoxysilane, and the aluminum oxide and γ-aminopropyltriethoxysilane each account for 2% of the amount of titanium dioxide. This improves the dispersibility of the inorganic particles in the polyester resin, reduces agglomeration, and achieves a more uniform dispersion, thereby improving fluidity. Furthermore, an appropriate amount of inorganic particles can provide nucleation cores to promote flow during the cooling and crystallization stage of the mixture melt, increase the flow rate of the mixture melt, and reduce the phenomenon of the mixture melt being easily broken during the pelletizer pulling process due to poor fluidity.

[0029] Modified inorganic particles are composited with polyolefin resins and polyester resins (carrier resins). Alumina, as an inorganic oxide, has surface hydroxyl groups (-OH) that can form hydrogen bonds or chemical bonds with hydroxyl groups on the surface of TiO2, forming a uniform Al2O3 coating. The surface polarity of the Al2O3 coating lies between that of TiO2 (high polarity) and PET (low polarity). This "transition layer" mitigates the polarity difference between the two, reducing interfacial tension. Simultaneously, weak interactions (such as van der Waals forces or coordination) with the ester groups (-COO-) in PET enhance interfacial adhesion. Silane coupling agents form covalent bonds (such as -Si-O-Ti bonds and -CONH- bonds) between TiO2 and PET, directly connecting the inorganic and organic phases. This enhances the compatibility of the inorganic particles with the polyolefin and polyester resins, and can improve the melt strength of the mixed material melt. At the same time, the melt strength of the mixture is significantly improved, preventing strand breakage caused by melt fracture during the process from extrusion through the extruder to underwater cooling, facilitating the continuous production of masterbatches. The modified inorganic particles are approximately spherical in shape, lacking sharp corners that could cause stress concentration. Their smooth surface quickly disperses and effectively absorbs external forces, providing a certain toughening effect on the mixture melt.

[0030] In addition, the interfacial adhesion of the modified inorganic particles and the particle size of the modified inorganic particles also have varying degrees of influence on the toughening effect. The nano-titanium dioxide inorganic particles selected by the present invention, which have been modified by both alumina surface coating and silane coupling agent surface infiltration, can improve interfacial adhesion. A large number of particles are dispersed in the mixture melt. The particle surfaces have been modified by alumina surface coating and silane coupling agent surface infiltration, and have good interfacial adhesion with both organic polyolefin resins and polyester resins. The modified inorganic particles can serve as a "connection point" to serve as a "node" connecting the two incompatible resins, polyolefin resin and polyester resin, effectively increasing the uniformity of the dispersion of polyolefin resin in polyester resin, helping to form a uniform, dense, and small interfacial separation phenomenon between polyolefin resin and polyester resin during subsequent melt extrusion and biaxial stretching processes, thereby improving the foaming effect inside the white polyester reflective film (the pore size and density of the pores in the film) and improving the reflective efficiency of the white reflective film.

[0031] The addition of modified inorganic particles in the present invention also has a certain degree of toughening effect on the mixture melt. This is the result of the combined effect of the modified inorganic particles and the matrix resin between adjacent particles. The amount of modified inorganic particles used has a significant impact on the toughening effect. The present invention limits the addition amount of modified inorganic particles to 5-15%, preferably 8-12%. If the amount is too small, the dispersion concentration is too low, and the ability of the modified inorganic particles to absorb internal stress is very small, and no significant toughening effect is achieved. If the amount is too large, the particles are too close together, the overall system viscosity of the mixture melt is greatly reduced, and a large number of small cracks generated under internal stress develop into internal cracks in the melt, which also fails to achieve a toughening effect.

[0032] The preparation process of modified inorganic particles is as follows:

[0033] 1. Titanium dioxide pretreatment: Place the titanium dioxide powder in an oven and dry it at 120°C for 2 hours to remove surface moisture. Then, add 0.5 kg of the dried titanium dioxide powder to 9.5 kg of anhydrous ethanol and ultrasonically disperse it in an ultrasonic cleaner for 30 minutes to form a uniform suspension.

[0034] 2. Alumina Coating: 0.01 kg of alumina sol was dropwise added to the titanium dioxide suspension while stirring at 50 rpm. Stirring was continued for 2 hours after the addition was complete. The mixture was then centrifuged at 3000 rpm for 10 minutes to obtain a precipitate. The precipitate was washed three times with deionized water to remove residual impurities, and then dried in an oven at 80°C for 6 hours to obtain alumina-coated titanium dioxide particles.

[0035] 3. Silane Coupling Agent Modification: Add 0.5 kg of dried alumina-coated titanium dioxide particles to 9.5 kg of anhydrous ethanol and sonicate for 20 minutes to form a uniform suspension. Then, add 0.01 kg of γ-aminopropyltriethoxysilane. Heat the suspension to 70°C while stirring at 50 rpm and maintain the temperature for 2 hours. After the reaction, centrifuge the mixture at 3000 rpm for 10 minutes to obtain a precipitate. Wash the precipitate three times with anhydrous ethanol to remove unreacted silane coupling agent, then dry it in an oven at 80°C for 4 hours to obtain the modified titanium dioxide particles.

[0036] The present invention uses a polyester resin (PET) mixed with a polyolefin resin, and limits the polyolefin resin content to 15-50%, ensuring that the prepared masterbatch forms sufficient pores during the subsequent stretching process of the white polyester film used, thereby enhancing the reflective effect of the white polyester film. The present invention uses a low-melt index polyolefin resin with a melt index of 25-80g / 10min. If the melt index of the polyolefin resin is too high, the melt strength of the mixed melt of the polyolefin and PET is too low during the masterbatch pelletizing process, and the material strands of the melt before entering underwater cooling are extremely easy to break during the process of being pulled by the pelletizer, making it difficult to continuously produce the masterbatch. If the melt index of the polyolefin resin is too low, the number of sufficient pores formed during the stretching process of the white polyester film is insufficient, and the size of the pores is too large, which is not conducive to improving the reflectivity of the white polyester film.

[0037] The present invention will be further described below with reference to the embodiments.

[0038] The preparation method of the high-flow polyolefin / polyester masterbatch of the present invention comprises the following steps:

[0039] a. Grinding the polyolefin resin and toughening agent separately by a pulverizer to obtain a powder mixture F1;

[0040] b. Mixing the powder mixture F1 obtained in step a with a compatibilizer and modified inorganic particles in a high-speed mixer to obtain a powder mixture F2;

[0041] c. The polyester resin and the powder mixture F2 obtained in step b are added to a twin-screw extruder through a loss-in-weight scale, and are fully mixed, plasticized, and melted to obtain a molten mixture;

[0042] d. The molten mixture obtained in step c is filtered, extruded through a die, cooled underwater, pelletized by a pelletizer, and dried to obtain a high-flowability polyolefin / polyester masterbatch.

[0043] The temperature of each zone of the twin-screw extruder is 250-270°C, the screw speed is 200-300r / min, the vacuum degree is -0.08-0.04MPa, the filter mesh aperture is 40μm, the water tank temperature is 15-25°C, and the hot air drying temperature is 100-160°C.

[0044] The high-flow polyolefin / polyester masterbatch prepared according to the above method was mixed with a polyester resin in a suitable proportion, melt-extruded through a twin-screw extruder, and biaxially stretched using a biaxial tensile testing machine to form a 150μm white polyester film. The white polyester film had an A / B / A or A / B structure, with the B layer comprising 40-70% of the polyester resin and 30-60% of the high-flow polyolefin / polyester masterbatch. The thickness of the white polyester film ranged from 50 to 350μm.

[0045] The white polyester film layer A can be added with polyester resin and corresponding functional materials, including but not limited to one or more combinations of anti-blocking masterbatch, matte masterbatch, antistatic masterbatch, and flame-retardant masterbatch, depending on the function and production requirements. The white polyester film layer B can also be added with corresponding functional materials, such as one or more combinations of amorphous polyester, additional titanium dioxide masterbatch, and toughening resin, depending on the function and production requirements.

[0046] The ratio of the biaxial stretching is 330%*380%.

[0047] The test standards and methods for the various properties of high-flow polyolefin / PET masterbatch experimental samples are as follows:

[0048] Strip forming performance: extrude the material through a twin-screw extruder, cool it underwater, maintain the pelletizer cutting speed at 300 rpm, observe whether the material strips can be continuously and stably formed into strips, and observe the number of strip breakages during the pelletizing process within 10 minutes. The fewer the number, the better the strip forming performance.

[0049] Flowability: According to ASTM D 1238, the masterbatch was dried at 120°C for 4 hours and then tested at 260°C at 2.16 kg using a melt indexer. The higher the melt index, the better the flowability of the masterbatch.

[0050] The test standards and methods for the various properties of white polyester film experimental samples are as follows:

[0051] Foaming efficiency: According to ASTM D792 standard, the density of the white polyester film sample was tested using an electronic density meter produced by Japan's ALFA MIRAGE company. The lower the density, the higher the foaming efficiency.

[0052] Reflectivity: In accordance with HG / T 4915-2016, the reflectivity was tested using a Konica Minolta CM-5 spectrophotometer under D65 light source using an integrating sphere with a d / 8 configuration. The reflectivity data is at a wavelength of 550nm. The higher the reflectivity, the better.

[0053] Example 1

[0054] According to the above method, high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 1 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 250 r / min to obtain the high-flow polyolefin / PET masterbatch M1.

[0055] Table 1 Masterbatch formula

[0056]

[0057]

[0058] Example 2

[0059] According to the above method, high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 2 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 250 rpm to obtain the high-flow polyolefin / PET masterbatch M2.

[0060] Table 2 Masterbatch formula

[0061]

[0062]

[0063] Example 3

[0064] According to the above method, high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 3 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 250 rpm to obtain the high-flow polyolefin / PET masterbatch M3.

[0065] Table 3 Masterbatch formula

[0066]

[0067] Example 4

[0068] According to the above method, high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 4 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 250 rpm to obtain the high-flow polyolefin / PET masterbatch M4.

[0069] Table 4 Masterbatch formula

[0070]

[0071] Example 5

[0072] According to the above method, high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 5 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 250 rpm to obtain the high-flow polyolefin / PET masterbatch M5.

[0073] Table 5 Masterbatch formula

[0074]

[0075]

[0076] Example 6

[0077] According to the above method, high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 6 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 230 rpm to obtain the high-flow polyolefin / PET masterbatch M6.

[0078] Table 6 Masterbatch formula

[0079]

[0080] Example 7

[0081] According to the above method, high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 7 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 250 rpm to obtain the high-flow polyolefin / PET masterbatch M7.

[0082] Table 7 Masterbatch formula

[0083]

[0084] Example 8

[0085] According to the above method, high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 8 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 270 rpm to obtain the high-flow polyolefin / PET masterbatch M8.

[0086] Table 8 Masterbatch formula

[0087]

[0088]

[0089] Example 9

[0090] According to the above method, high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 9 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 250 rpm to obtain the high-flow polyolefin / PET masterbatch M9.

[0091] Table 9 Masterbatch formula

[0092]

[0093] Example 10

[0094] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 10 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 210 rpm to obtain the high-flowability polyolefin / PET masterbatch M10.

[0095] Table 10 Masterbatch formula

[0096]

[0097] Example 11

[0098] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 11 below were added to a twin-screw extruder. The barrel temperature in the melting section of the extruder was 250°C and the screw speed was 200 rpm to obtain the high-flowability polyolefin / PET masterbatch M11.

[0099] Table 11 Masterbatch formula

[0100]

[0101]

[0102] Example 12

[0103] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 12 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 260°C and the screw speed was 250 rpm to obtain the high-flowability polyolefin / PET masterbatch M12.

[0104] Table 12 Masterbatch formula

[0105]

[0106] Example 13

[0107] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 13 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 260°C and the screw speed was 250 rpm to obtain the high-flowability polyolefin / PET masterbatch M13.

[0108] Table 13 Masterbatch formula

[0109]

[0110] Example 14

[0111] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 14 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 260°C and the screw speed was 250 rpm to obtain the high-flowability polyolefin / PET masterbatch M14.

[0112] Table 14 Masterbatch formula

[0113]

[0114]

[0115] Example 15

[0116] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 15 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 250°C and the screw speed was 200 rpm to obtain the high-flowability polyolefin / PET masterbatch M15.

[0117] Table 15 Masterbatch formula

[0118]

[0119]

[0120] Example 16

[0121] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 16 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 250 rpm to obtain the high-flowability polyolefin / PET masterbatch M16.

[0122] Table 16 Masterbatch formula

[0123]

[0124] Example 17

[0125] According to the above method, a high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 17 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 250°C and the screw speed was 270 rpm to obtain the high-flow polyolefin / PET masterbatch M17.

[0126] Table 17 Masterbatch formula

[0127]

[0128]

[0129] Example 18

[0130] According to the above method, a high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 18 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 250°C and the screw speed was 200 rpm to obtain the high-flow polyolefin / PET masterbatch M18.

[0131] Table 18 Masterbatch formula

[0132]

[0133]

[0134] Example 19

[0135] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 19 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 250 rpm to obtain the high-flowability polyolefin / PET masterbatch M19.

[0136] Table 19 Masterbatch formula

[0137]

[0138] Example 20

[0139] According to the above method, a high-flow polyolefin / PET masterbatch was prepared. The raw materials of the formula in Table 20 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 250 rpm to obtain the high-flow polyolefin / PET masterbatch M20.

[0140] Table 20 Masterbatch formula

[0141]

[0142] Comparative Example 1

[0143] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 21 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 280°C and the screw speed was 250 rpm to obtain the high-flowability polyolefin / PET masterbatch M21.

[0144] Table 21 Masterbatch formula

[0145]

[0146]

[0147] Comparative Example 2

[0148] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 22 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 240°C and the screw speed was 190 rpm to obtain the high-flowability polyolefin / PET masterbatch M22.

[0149] Table 22 Masterbatch formula

[0150]

[0151] Comparative Example 3

[0152] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 23 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 260°C and the screw speed was 250 rpm to obtain the high-flowability polyolefin / PET masterbatch M23.

[0153] Table 22 Masterbatch formula

[0154]

[0155] Comparative Example 4

[0156] High-flowability polyolefin / PET masterbatch was prepared according to the above method. The raw materials of the formula in Table 24 below were added to a twin-screw extruder. The barrel temperature of the extruder melt section was 270°C and the screw speed was 310 rpm to obtain the high-flowability polyolefin / PET masterbatch M24.

[0157] Table 24 Masterbatch formula

[0158]

[0159]

[0160] The performance test results of the products of various embodiments and comparative examples are shown in Table 25.

[0161] Table 25 Performance test results

[0162]

[0163]

[0164] As shown in Table 25, the test data from Example 5 and Comparative Example 1 indicate that when the polyolefin resin content is too low and the polyolefin melt index is too high, the strand forming performance of the masterbatch during pelletization is reduced. The white polyester film samples made from the masterbatch exhibit low foaming efficiency and reflectivity. The excessive addition of modified inorganic particles in Comparative Example 1 results in low melt viscosity and strength, and increased strand breakage.

[0165] The test data of Example 5 and Comparative Example 2 show that when the polyolefin resin content is too high, the melt viscosity and strength of the masterbatch are too low, the strip-forming performance of the masterbatch during granulation is extremely poor, the dispersibility of the polyolefin resin in the carrier resin is poor, and the reflectivity of the white polyester film experimental sample made from the masterbatch is also low.

[0166] The test data from Example 19, Comparative Examples 3, and Comparative Examples 4 show that when the polyolefin melt index is too low, the polyolefin resin has poor dispersion in the carrier resin, resulting in low reflectivity of white polyester film samples made from the masterbatch. The addition of ordinary inorganic particles in Comparative Example 3, which were not modified, resulted in poor dispersibility in the white polyester film sample, resulting in low reflectivity of the film sample. In Comparative Example 4, where no modified inorganic particles were added, the masterbatch had insufficient melt flow properties, resulting in increased breakage. Furthermore, the lack of modified inorganic particles also resulted in low reflectivity of the film sample.

[0167] The test results shown in Table 25 above indicate that the polyolefin / PET masterbatch provided by the present invention exhibits good strip-forming properties and flowability during the masterbatch pelletizing process; the white polyester film produced from the masterbatch exhibits excellent foaming efficiency and high reflectivity. The masterbatch provided in Examples 5-7 exhibits good strip-forming properties, and the resulting white polyester films exhibit excellent foaming efficiency and emissivity, resulting in superior overall performance.

[0168] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description is not intended to limit the present invention. Those skilled in the art will appreciate that, based on the teachings of this specification, modifications or adjustments may be made to the present invention. Such modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A high-flow polyolefin / polyester masterbatch, characterized by: The masterbatch comprises the following components in percentage by weight: Polyolefin resin 15~50% Polyester resin 27~78% Modified inorganic particles 5~15% Toughener 1~5% Dispersant 1~3%.

2. The high-flowability polyolefin / polyester masterbatch according to claim 1, characterized in that: The modified inorganic particles are nano-titanium dioxide particles that have been simultaneously modified by surface coating with aluminum oxide and surface infiltration with a silane coupling agent, and have an average particle size of 200-500 nm.

3. The high-flowability polyolefin / polyester masterbatch according to claim 1, characterized in that: The polyolefin resin includes one or more of polymethylpentene, polypropylene, and cycloolefin copolymer; the melt index of the polyolefin resin is 25-80 g / 10min, and the test conditions are 260°C and 5kg.

4. The high-flowability polyolefin / polyester masterbatch according to claim 1, characterized in that: The polyester resin is polyethylene terephthalate chips, and its intrinsic viscosity is 0.68-1.0 dL / g.

5. The high-flowability polyolefin / polyester masterbatch according to claim 1, characterized in that: The toughening agent is a composition of POE grafted GMA and amorphous copolyester, and the weight ratio of the POE grafted GMA to the amorphous copolyester is 1: (1-2).

6. The high-flowability polyolefin / polyester masterbatch according to claim 5, characterized in that: The amorphous copolyester is PETG resin.

7. The high-flowability polyolefin / polyester masterbatch according to claim 1, characterized in that: The dispersant includes one or more of polyethylene glycol, polyethylene wax, and polypropylene wax.

8. A method for preparing a high-flowability polyolefin / polyester masterbatch according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: a. Grinding the polyolefin resin and toughening agent separately by a pulverizer to obtain a powder mixture F1; b. Mixing the powder mixture F1 obtained in step a with a compatibilizer and modified inorganic particles in a high-speed mixer to obtain a powder mixture F2; c. The polyester resin and the powder mixture F2 obtained in step b are added to a twin-screw extruder through a loss-in-weight scale, and are fully mixed, plasticized, and melted to obtain a molten mixture; d. The molten mixture obtained in step c is filtered, extruded through a die, cooled underwater, pelletized by a pelletizer, and dried to obtain a high-flowability polyolefin / polyester masterbatch.

9. The method for preparing high-flow polyolefin / polyester masterbatch according to claim 8, characterized in that: In the step c, during the melt extrusion process, the temperature of each zone of the twin-screw extruder is 250-270°C, the screw speed is 200-300 r / min, the vacuum degree is -0.08-0.04 MPa, the filter mesh pore size is 40 μm, the water tank temperature is 15-25°C, and the hot air drying temperature is 100-160°C.

10. An application of a high-flow polyolefin / polyester masterbatch, characterized by: The high-fluidity polyolefin / polyester masterbatch obtained according to any one of claims 1 to 9 is suitable for use in white polyester film, and the high-fluidity polyolefin / polyester masterbatch and polyester resin are mixed, melt-extruded, and biaxially stretched to prepare the white polyester film.

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