Acid-resistant PC + PCTG composite material applied to food and medical grade and good in TPE (thermoplastic elastomer) adhesion and preparation method of PC + PCTG composite material

Abstract

The invention relates to the technical field of medical materials, in particular to a PC + PCTG composite material applied to food and medical grade and good in acid resistance and TPE adhesion and a preparation method of the PC + PCTG composite material. The material is prepared from the following components in parts by weight: 60 to 70 parts of 1, 4-cyclohexanedimethanol ester (PCTG) resin, 30 to 40 parts of polycarbonate (PC) resin, 3 to 5 parts of styrene-acrylonitrile-maleic anhydride terpolymer, 5 to 10 parts of dimethyl silane polyhedral oligomeric silsesquioxane, 2 to 5 parts of silicon carbide whisker, 1 to 4 parts of tri [2.4-di-tert-butylphenyl] phosphite and 0.5 to 1 part of polyolefin wax. The PCTG resin and the PC resin are used as matrixes to form the composite material, and the composite material has excellent acid resistance through synergistic compounding of the dimethyl silane polyhedral oligomeric silsesquioxane and the silicon carbide whiskers, and has good application in food and medical industries.

Description

Technical Field

[0001] The present invention relates to the technical field of medical materials, and more specifically to a PC+PCTG composite material which is acid-resistant and has good TPE adhesion and is applied to food and medical grade, and a preparation method thereof. Background Art

[0002] PCTG is a high-performance transparent plastic material, and its full name is Poly(1,4-Cyclohexylene Dimethylene Terephthalate Glycol). It is an amorphous copolyester, which is made by polycondensing terephthalic acid (PTA), ethylene glycol (EG) and 1,4-cyclohexanedimethanol (CHDM) by ester exchange. It has good viscosity, transparency, color, chemical resistance and stress whitening resistance; it is highly transparent and has excellent impact resistance. It is particularly suitable for forming thick-walled transparent products and is widely used in the food packaging industry, daily necessities and cosmetics packaging, medical equipment and other fields.

[0003] Polycarbonate (PC) has good comprehensive properties, but it is prone to stress cracking, and its wear resistance and weather resistance (especially resistance to ultraviolet light aging) are poor, which limits the practical application of PC.

[0004] Patent CN 112724634 A discloses a PC / PCTG alloy, which is made from the following raw materials in parts by weight: 40-50 parts of PC, 30-50 parts of polyester PCTG, 10-20 parts of polysiloxane, 0.9-3 parts of antioxidant, and 0.5-1.0 parts of nano zirconium phosphate. It can be used for in-mold insert injection molding process, and has the advantages of high fluidity and low-temperature molding, and the yield rate of the plastic parts obtained by injection molding is high.

[0005] Patent CN 115612264 A discloses a PC / PCTG alloy and its preparation method and application. The material is prepared from the following raw materials by weight: 10-20 parts of modified carbon fiber, 55-65 parts of PCTG, 30-45 parts of PC, 5-8 parts of MBS, 1-3 parts of coupling agent, 1-3 parts of antioxidant, and 1-2 parts of lubricant. The PC / PCTG alloy can improve the bonding problem between carbon fiber and PC without the need for an interface modifier. The alloy has good flexibility and excellent mechanical and acoustic properties.

[0006] Overmolding is a technique that uses multiple injection molding in different mold cavities. It is usually used to make parts with a variety of different component structures and to produce products with rigid structures and flexible surfaces. Among them, considering the adhesion between the rigid structure and the flexible surface is an important aspect of examining the performance of composite materials.

[0007] Patent CN 113817283 A discloses a TPE alloy material for encapsulating PBT, characterized in that it comprises the following raw materials in parts by weight: hydrogenated styrene elastomer: 25-40 parts, two-block styrene polymer: 10-20 parts, plasticizer: 20-40 parts, polyester hot melt adhesive: 20-40 parts, compatibilizer: 3-6 parts, anti-aging agent: 0.1-0.6 parts. The TPE alloy material has good compatibility with PBT and strong adhesion.

[0008] Although there are many studies on PC+PCTG composite materials in the existing technology, there are few studies on the adhesion between them and TPE. Summary of the invention

[0009] Based on the deficiencies and needs of the prior art, the present invention provides a food and medical grade PC+PCTG composite material and a preparation method thereof. The PC+PCTG composite material has excellent acid resistance and high adhesion with thermoplastic elastomer (TPE), which provides a good guarantee for the application of the PC+PCTG composite material in overmolding technology.

[0010] In order to achieve the purpose of the present invention, the present invention provides the following technical solutions:

[0011] A PC+PCTG composite material with good acid resistance and TPE adhesion for food and medical grade, comprising the following components by weight:

[0012] 60-70 parts of polyethylene terephthalate glycol-1,4-cyclohexanedimethanol (PCTG) resin, 30-40 parts of polycarbonate (PC) resin,

[0013] 3-5 parts of styrene-acrylonitrile-maleic anhydride terpolymer,

[0014] 5-10 parts of dimethylsilyl cage-shaped polysilsesquioxane,

[0015] 2-5 parts of silicon carbide whiskers,

[0016] 1 to 4 parts of tris[2,4-di-tert-butylphenyl]phosphite,

[0017] 0.5-1 part of polyolefin wax.

[0018] Furthermore, the PC+PCTG composite material comprises the following components in parts by weight:

[0019] 64-66 parts of polyethylene terephthalate glycol-1,4-cyclohexanedimethanol (PCTG) resin, 33-37 parts of polycarbonate (PC) resin,

[0020] 4-5 parts of styrene-acrylonitrile-maleic anhydride terpolymer,

[0021] 7-8 parts of dimethylsilyl cage-shaped polysilsesquioxane,

[0022] 3-4 parts of silicon carbide whiskers,

[0023] 2-3 parts of tris[2,4-di-tert-butylphenyl]phosphite,

[0024] 0.7-0.8 parts of polyolefin wax.

[0025] Furthermore, the PC+PCTG composite material is composed of the following components in parts by weight:

[0026] 64-66 parts of polyethylene terephthalate glycol-1,4-cyclohexanedimethanol (PCTG) resin, 33-37 parts of polycarbonate (PC) resin,

[0027] 4-5 parts of styrene-acrylonitrile-maleic anhydride terpolymer,

[0028] 7-8 parts of dimethylsilyl cage-shaped polysilsesquioxane,

[0029] 3-4 parts of silicon carbide whiskers,

[0030] 2-3 parts of tris[2,4-di-tert-butylphenyl]phosphite,

[0031] 0.7-0.8 parts of polyolefin wax.

[0032] Furthermore, the silicon carbide whisker has a diameter of 20 to 100 nm and a length of 0.3 to 1 μm.

[0033] In the present invention, PCTG resin and PC resin are used as main components, and the content of PCTG resin is reasonably controlled to be significantly higher than that of PC resin, so that the basic mechanical properties of the composite material can be guaranteed and the defect of poor acid resistance of PC resin can be improved to the greatest extent.

[0034] In the present invention, dimethylsilyl cage-shaped polysilsesquioxane is added to the composite material, and during the overmolding process, when the thermoplastic elastomer is melted, the end group of the siloxane is grafted or block copolymerized with the reactive group (such as hydroxyl group, carboxyl group) of the TPE to chemically react, so that the molecular chain of the siloxane and the TPE are connected to form a covalent bond; in addition, the rigid three-dimensional skeleton of the cage-shaped polysilsesquioxane is also conducive to forming a stable and firm structure, providing a good foundation for improving the adhesion of the bonding interface treatment. At the same time, the dimethylsilyl cage-shaped polysilsesquioxane will not significantly reduce the mechanical properties of the composite material.

[0035] In the present invention, silicon carbide whiskers are added to the composite material. Silicon carbide can usually be used as a thermal conductive filler in polymer materials. Since the main purpose of the present application is to improve the adhesion, silicon carbide whiskers are selected. By utilizing the characteristics of their long diameter, they can form a network interface with the thermoplastic elastomer when it is melted during the overmolding process, which can significantly improve the adhesion between the composite material and TPE.

[0036] The present invention has found that by adding dimethylsilyl cage-shaped polysilsesquioxane and silicon carbide whiskers into the composite material, the adhesion can be improved synergistically.

[0037] In the present invention, styrene-acrylonitrile-maleic anhydride terpolymer (SAM) is used as a compatibilizer, which can form a chemical or physical bond with a polymer matrix through its polar group to improve the compatibility between different polymers; SMA can be used as a surfactant to increase the bonding strength between two polymers to form a stable structure.

[0038] A method for preparing a PC+PCTG composite material with good acid resistance and TPE adhesion for food and medical grade, characterized by comprising the following steps:

[0039] (1) Weigh the components in proportion for later use;

[0040] (2) mixing parts by weight of polyethylene terephthalate-1,4-cyclohexanedimethanol ester resin and polycarbonate resin uniformly, adding the mixture into an internal mixer for melt blending and granulation to obtain material group A;

[0041] (3) Pour parts by weight of ethylene-acrylonitrile-maleic anhydride terpolymer, dimethylsilyl cage-shaped polysilsesquioxane, silicon carbide whisker, tris[2,4-di-tert-butylphenyl]phosphite, tris(2,4-di-tert-butylphenyl)phosphite, and polyolefin wax into a stirring device and stir evenly to form material group B;

[0042] (3) Material group A is fed from the main feed of a twin-screw extruder, and material group B is fed from the side feed of the twin-screw extruder, and the mixture is melted, mixed, and extruded through the twin-screw extruder to obtain a PC+PCTG composite material.

[0043] Furthermore, the set temperature of the twin-screw extruder is: section one: 250-260°C, section two: 255-265°C, section three: 260-270°C, section four: 265-275°C, section five: 265-275°C, section six: 250-260°C, section seven: 250-260°C, section eight: 255-265°C, section nine: 260-270°C, and die head: 265-275°C.

[0044] Furthermore, the rotation speed of the twin-screw extruder is 300-350 rpm.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The present invention uses PCTG resin and PC resin as a matrix to form a composite material. By adopting a synergistic compounding of dimethylsilyl cage-shaped polysilsesquioxane and silicon carbide whiskers, the adhesion of the composite material to the TPE material during overmolding is greatly improved, which provides a good guarantee for the application of PC+PCTG composite materials in overmolding technology.

[0047] (2) The PC+PCTG composite material provided by the present invention has excellent acid resistance and has good application in the food and medical industries. DETAILED DESCRIPTION

[0048] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0049] The main materials used in the embodiments and comparative examples of the present invention are, but not limited to, the following materials: PCTG resin is American Eastman food grade PCTG, brand TX1001;

[0050] PC resin is Korean LG Chemical food-grade PC, brand 1201-15;

[0051] SAM is a product of Jiayirong Polymer (Shanghai) Co., Ltd., brand name SAM-010;

[0052] Dimethylsilyl cage-shaped polysilsesquioxane is a product of Suzhou Kaifa New Material Technology Co., Ltd.;

[0053] The silicon carbide whisker is Brofos-SiC-X500, a product of Brofos Nano-Tech (Ningbo) Co., Ltd.

[0054] Example 1

[0055] A PC+PCTG composite material with good acid resistance and TPE adhesion for food and medical grade, composed of the following components by weight:

[0056] 64 parts of polyethylene terephthalate glycol-1,4-cyclohexanedimethanol (PCTG) resin, 33 parts of polycarbonate (PC) resin,

[0057] 4 parts of styrene-acrylonitrile-maleic anhydride terpolymer,

[0058] 7 parts of dimethylsilyl cage-shaped polysilsesquioxane,

[0059] 3 parts of silicon carbide whiskers,

[0060] 2 parts of tris[2,4-di-tert-butylphenyl]phosphite,

[0061] Polyolefin wax 0.7 parts.

[0062] Wherein, the diameter of the silicon carbide whisker is 20-100 nm and the length is 0.3-1 μm.

[0063] The preparation method of the above-mentioned PC+PCTG composite material is characterized in that it comprises the following steps:

[0064] (1) Weigh the components in proportion for later use;

[0065] (2) mixing parts by weight of polyethylene terephthalate-1,4-cyclohexanedimethanol ester resin and polycarbonate resin uniformly, adding the mixture into an internal mixer for melt blending and granulation to obtain material group A;

[0066] (3) Pour parts by weight of ethylene-acrylonitrile-maleic anhydride terpolymer, dimethylsilyl cage-shaped polysilsesquioxane, silicon carbide whisker, tris[2,4-di-tert-butylphenyl]phosphite, tris(2,4-di-tert-butylphenyl)phosphite, and polyolefin wax into a stirring device and stir evenly to form material group B;

[0067] (3) Material group A is fed from the main feed of a twin-screw extruder, and material group B is fed from the side feed of the twin-screw extruder, and the mixture is melted, mixed, and extruded through the twin-screw extruder to obtain a PC+PCTG composite material.

[0068] Among them, the set temperatures of the twin-screw extruder are: section one: 250°C, section two: 255°C, section three: 260°C, section four: 265°C, section five: 265°C, section six: 250°C, section seven: 250°C, section eight: 255°C, section nine: 260°C, and die head: 265°C.

[0069] Wherein, the rotation speed of the twin-screw extruder is 300 rpm.

[0070] Example 2

[0071] A PC+PCTG composite material with good acid resistance and TPE adhesion for food and medical grade, composed of the following components by weight:

[0072] 66 parts of polyethylene terephthalate glycol-1,4-cyclohexanedimethanol (PCTG) resin, 37 parts of polycarbonate (PC) resin,

[0073] 5 parts of styrene-acrylonitrile-maleic anhydride terpolymer,

[0074] 8 parts of dimethylsilyl cage-shaped polysilsesquioxane,

[0075] 4 parts of silicon carbide whiskers,

[0076] 3 parts of tris[2,4-di-tert-butylphenyl]phosphite,

[0077] 0.8 parts of polyolefin wax.

[0078] Wherein, the diameter of the silicon carbide whisker is 20-100 nm and the length is 0.3-1 μm.

[0079] The preparation method of the above-mentioned PC+PCTG composite material is characterized in that it comprises the following steps:

[0080] (1) Weigh the components in proportion for later use;

[0081] (2) mixing parts by weight of polyethylene terephthalate-1,4-cyclohexanedimethanol ester resin and polycarbonate resin uniformly, adding the mixture into an internal mixer for melt blending and granulation to obtain material group A;

[0082] (3) Pour parts by weight of ethylene-acrylonitrile-maleic anhydride terpolymer, dimethylsilyl cage-shaped polysilsesquioxane, silicon carbide whisker, tris[2,4-di-tert-butylphenyl]phosphite, tris(2,4-di-tert-butylphenyl)phosphite, and polyolefin wax into a stirring device and stir evenly to form material group B;

[0083] (3) Material group A is fed from the main feed of a twin-screw extruder, and material group B is fed from the side feed of the twin-screw extruder, and the mixture is melted, mixed, and extruded through the twin-screw extruder to obtain a PC+PCTG composite material.

[0084] Among them, the set temperatures of the twin-screw extruder are: section one: 260°C, section two: 265°C, section three: 270°C, section four: 275°C, section five: 275°C, section six: 260°C, section seven: 260°C, section eight: 265°C, section nine: 270°C, and die head: 275°C.

[0085] Wherein, the rotation speed of the twin-screw extruder is 350rmp.

[0086] Example 3

[0087] A PC+PCTG composite material with good acid resistance and TPE adhesion for food and medical grade, composed of the following components by weight:

[0088] 65 parts of polyethylene terephthalate glycol-1,4-cyclohexanedimethanol (PCTG) resin, 35 parts of polycarbonate (PC) resin,

[0089] 4.5 parts of styrene-acrylonitrile-maleic anhydride terpolymer,

[0090] 7.5 parts of dimethylsilyl cage-shaped polysilsesquioxane,

[0091] 3.5 parts of silicon carbide whiskers,

[0092] 2.5 parts of tris[2,4-di-tert-butylphenyl]phosphite,

[0093] Polyolefin wax 0.7 parts.

[0094] Wherein, the diameter of the silicon carbide whisker is 20-100 nm and the length is 0.3-1 μm.

[0095] The preparation method of the above-mentioned PC+PCTG composite material is characterized in that it comprises the following steps:

[0096] (1) Weigh the components in proportion for later use;

[0097] (2) mixing parts by weight of polyethylene terephthalate-1,4-cyclohexanedimethanol ester resin and polycarbonate resin uniformly, adding the mixture into an internal mixer for melt blending and granulation to obtain material group A;

[0098] (3) Pour parts by weight of ethylene-acrylonitrile-maleic anhydride terpolymer, dimethylsilyl cage-shaped polysilsesquioxane, silicon carbide whisker, tris[2,4-di-tert-butylphenyl]phosphite, tris(2,4-di-tert-butylphenyl)phosphite, and polyolefin wax into a stirring device and stir evenly to form material group B;

[0099] (3) Material group A is fed from the main feed of a twin-screw extruder, and material group B is fed from the side feed of the twin-screw extruder, and the mixture is melted, mixed, and extruded through the twin-screw extruder to obtain a PC+PCTG composite material.

[0100] Among them, the set temperatures of the twin-screw extruder are: section one: 255°C, section two: 260°C, section three: 265°C, section four: 270°C, section five: 270°C, section six: 255°C, section seven: 255°C, section eight: 260°C, section nine: 265°C, and die head: 270°C.

[0101] Wherein, the rotation speed of the twin-screw extruder is 330 rpm.

[0102] Comparative Example 1

[0103] Comparative Example 1 is substantially the same as Example 3, except that dimethylsilyl cage-shaped polysilsesquioxane is not added in Comparative Example 1.

[0104] Comparative Example 2

[0105] Comparative Example 2 is substantially the same as Example 3, except that silicon carbide whiskers are not added in Comparative Example 2.

[0106] The properties of the PC+PCTG composite materials prepared in Examples 1-3 and Comparative Examples 1-2 were tested. Specifically:

[0107] 1. Tensile strength: measured according to the national standard: GB / T 1040.1-2006 "Determination of tensile properties of plastics Part 1: General principles";

[0108] 2. Bending strength: Test the bending strength according to the national standard: GB / T 9341-2000 "Test method for bending properties of plastics";

[0109] 3: Acid and alkali resistance: The samples were immersed in an acidic solution (10wt.% HCl) and an alkaline solution (15wt.% NaOH) for 128h, and the surface conditions were observed.

[0110] 4: Adhesion test: Referring to the standard GB / T 7760-2003 "Determination of the bond strength between vulcanized rubber or thermoplastic rubber and hard plate material - 90 degree peeling method", the PC+PCTG composite material of the present application and ethylene-vinyl acetate copolymer are formed into a test sample by overmolding; one end is fixed and the other end is stretched at a rate of 50 mm / min until the two materials are separated, so as to measure the bonding strength.

[0111] The specific test data are recorded in Table 1.

[0112] Table 1

[0113]

[0114] The above tests show that the PC+PCTG composite materials prepared in the embodiments and comparative examples of the present invention have excellent acid and alkali resistance. After being immersed in acid and alkali solutions for 128 hours, the surface remains smooth without any corrosion defects such as cracks and pits.

[0115] The PC+PCTG composite material prepared in the embodiment of the present invention has good mechanical properties such as tensile strength and flexural strength; the addition of dimethylsilyl cage-shaped polysilsesquioxane and silicon carbide whiskers can improve its mechanical properties to a certain extent.

[0116] The PC+PCTG composite material prepared in the embodiment of the present invention has excellent adhesion to TPE, indicating that the PC+PCTG composite material and TPE can form a strong bonding interface, significantly improving the bonding performance of the two; compared with Comparative Examples 1-2, it can be explained that the degree of improvement of the adhesion by silicon carbide whiskers is higher than that of dimethylsilyl cage-shaped polysilsesquioxane, but the two can work synergistically to improve the adhesion between the PC+PCTG composite material and TPE.

[0117] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A PC+PCTG composite material with good acid resistance and TPE adhesion for food and medical grade, characterized in that: By weight, it includes the following components: 60-70 parts of polyethylene terephthalate (PCTG) resin, 30-40 parts of polycarbonate (PC) resin, 3-5 parts of styrene-acrylonitrile-maleic anhydride terpolymer, 5-10 parts of dimethylsilyl cage-shaped polysilsesquioxane, 2-5 parts of silicon carbide whiskers, 1 to 4 parts of tris[2,4-di-tert-butylphenyl]phosphite, 0.5-1 part of polyolefin wax.

2. The PC+PCTG composite material according to claim 1, characterized in that: By weight, it includes the following components: 64-66 parts of polyethylene terephthalate (PCTG) resin, Polycarbonate (PC) resin 33-37 parts, 4-5 parts of styrene-acrylonitrile-maleic anhydride terpolymer, 7-8 parts of dimethylsilyl cage-shaped polysilsesquioxane, 3-4 parts of silicon carbide whiskers, 2-3 parts of tris[2,4-di-tert-butylphenyl]phosphite, 0.7-0.8 parts of polyolefin wax.

3. The PC+PCTG composite material according to claim 1, characterized in that: By weight, it is composed of the following components: 64-66 parts of polyethylene terephthalate (PCTG) resin, Polycarbonate (PC) resin 33-37 parts, 4-5 parts of styrene-acrylonitrile-maleic anhydride terpolymer, 7-8 parts of dimethylsilyl cage-shaped polysilsesquioxane, 3-4 parts of silicon carbide whiskers, 2-3 parts of tris[2,4-di-tert-butylphenyl]phosphite, 0.7-0.8 parts of polyolefin wax.

4. The PC+PCTG composite material according to any one of claims 1 to 3, characterized in that: The silicon carbide whisker has a diameter of 20 to 100 nm and a length of 0.3 to 1 μm.

5. A method for preparing a PC+PCTG composite material with good acid resistance and TPE adhesion for food and medical use as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: (1) Weigh the components in proportion for later use; (2) mixing parts by weight of polyethylene terephthalate-1,4-cyclohexanedimethanol ester resin and polycarbonate resin uniformly, adding the mixture into an internal mixer for melt blending and granulation to obtain material group A; (3) Pour parts by weight of ethylene-acrylonitrile-maleic anhydride terpolymer, dimethylsilyl cage-shaped polysilsesquioxane, silicon carbide whisker, tris[2,4-di-tert-butylphenyl]phosphite, tris(2,4-di-tert-butylphenyl)phosphite, and polyolefin wax into a stirring device and stir evenly to form material group B; (3) Material group A is fed from the main feed of a twin-screw extruder, and material group B is fed from the side feed of the twin-screw extruder, and the mixture is melted, mixed, and extruded through the twin-screw extruder to obtain a PC+PCTG composite material.

6. The method for preparing the PC+PCTG composite material according to claim 5, characterized in that: The set temperatures of the twin-screw extruder are: first section: 250-260°C, second section: 255-265°C, third section: 260-270°C, fourth section: 265-275°C, fifth section: 265-275°C, sixth section: 250-260°C, seventh section: 250-275°C 260℃, stage 8: 255~265℃, stage 9: 260~270℃, machine head: 265~275℃.

7. The method for preparing the PC+PCTG composite material according to claim 5, characterized in that: The rotation speed of the twin-screw extruder is 300-350 rpm.

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