A high heat-resistant flame-retardant PC material with excellent paint resistance and its preparation method

Abstract

The present invention relates to a highly heat-resistant and flame-retardant PC material with excellent paint resistance, comprising polycarbonate, a paint-resistant modified masterbatch, a compatibilizer, a flame retardant, an antioxidant, and a lubricant. The paint-resistant modified masterbatch comprises polycaprolactam and epoxy resin, which are mixed in proportion and prepared by extrusion and granulation. The paint-resistant modified masterbatch of the present invention is prepared by cross-linking the amino groups of the polycaprolactam in the paint-resistant modified masterbatch with the highly reactive epoxy groups in the epoxy resin, and by using a specific compatibilizer. This not only improves the compatibility of the polycarbonate with the paint-resistant modified masterbatch, enhancing the material's toughness, but also improves the paint resistance of the polycarbonate. The addition of the flame retardant compensates for the effects of the paint-resistant modified masterbatch and the compatibilizer on the flame retardancy of the polycarbonate.

Description

Technical Field

[0001] The present invention belongs to the field of polymer materials, and in particular relates to a highly heat-resistant and flame-retardant PC material with excellent paint resistance and a preparation method thereof. Background Art

[0002] Polycarbonate (PC) is an amorphous thermoplastic engineering plastic with excellent optical clarity, impact toughness, and heat resistance. It is currently widely used in electronics, home appliances, automobiles, lighting equipment, medical devices, and other fields. Despite these advantages, many industrial PC products, such as wall switches, range hood panels, and medical device housings, often experience cracking after painting or contact with chemical reagents.

[0003] There are two common ways to improve PC's paintability: 1. Adding ABS, especially ABS with a high AN content, can improve PC's paintability. However, the addition of ABS significantly reduces PC's heat resistance and flame retardancy. 2. Blending with crystalline resins, such as PBT and PET, increases the added content. This not only reduces the PC's heat resistance and flame retardancy, but also increases shrinkage, leading to smaller products in actual production. Therefore, in applications requiring heat resistance and flame retardancy, such as painted switch panels, which require a heat ball pressure greater than 125°C and a GWFI (870°C 81.5mm), neither of the above methods can meet these requirements.

[0004] There are currently no reports on patents that simultaneously meet the above requirements of temperature resistance, flame retardancy, and sprayability. Therefore, it is very meaningful to develop a highly heat-resistant and flame-retardant PC with excellent paint resistance. Summary of the Invention

[0005] The purpose of the present invention is to provide a high heat-resistant and flame-retardant PC material with excellent paint resistance and a preparation method thereof in response to the problems existing in the prior art.

[0006] The purpose of the present invention can be achieved by the following solutions:

[0007] The present invention provides a high heat-resistant and flame-retardant PC material with excellent paint resistance, wherein the high heat-resistant and flame-retardant PC material comprises the following components in parts by weight:

[0008]

[0009]

[0010] The polycarbonate has a number average molecular weight of 18,000-36,000 g / mol and a melt flow rate of 3-20 g / 10 min (300° C. / 1.23 g).

[0011] The paint-resistant modified masterbatch is prepared by extruding and granulating a mixed resin including polycaprolactam and epoxy resin. The epoxy resin includes one or more of bisphenol A epoxy resin, aliphatic epoxy resin, and brominated epoxy resin.

[0012] Paint-resistant modified masterbatches contain PA6 resin, which inherently exhibits excellent solvent resistance. Directly blending polycaprolactam with PC results in poor compatibility. Therefore, the addition of epoxy resin allows amino groups to react with epoxy groups, forming a similar structure within the polycaprolactam: amino-epoxy-PC. This improves the compatibility between PC and PA, further enhancing spray paint resistance. Furthermore, the highly reactive epoxy resin groups can crosslink with PC, reacting with their terminal hydroxyl groups to enhance crosslinking and improve the material's spray paint resistance. Without a masterbatch, poor compatibility can occur.

[0013] The mass ratio of polycaprolactam to epoxy resin is 85-95:15-5, preferably 90:10; the extrusion temperature is 220-270°C. Too little polycaprolactam and a high number of epoxy groups can lead to uneven dispersibility during production; too much polycaprolactam requires the addition of a larger amount of paint-resistant modified masterbatch for improved paint resistance, which is detrimental to formulation design.

[0014] The compatibilizer is a maleic anhydride-grafted polyolefin, including one or more of maleic anhydride-grafted polypropylene and maleic anhydride-grafted polyethylene. Maleic anhydride groups react with the terminal hydroxyl groups in PC. Polyolefins are excellent for toughening PA, so maleic anhydride-grafted polyolefins are selected as the compatibilizer.

[0015] The flame retardant includes one or more of brominated polycarbonate, bromotriazine, brominated epoxy, and tetrabromobisphenol A.

[0016] The antioxidant includes one or more of the commercially available antioxidant 1076, antioxidant 168, antioxidant 245, and antioxidant 1010.

[0017] The lubricant includes one or more of pentaerythritol ester, silicone powder, and ethylene bisstearamide.

[0018] The present invention also provides a method for preparing the highly heat-resistant and flame-retardant PC material, comprising the following steps:

[0019] S1. Weigh the raw materials according to the following weight parts:

[0020]

[0021]

[0022] S2. Mix the above raw materials according to the proportions, stir them, melt and extrude them after mixing them evenly, and cool and granulate them to obtain the high heat-resistant and flame-retardant PC material.

[0023] In step S1, the specific preparation steps of the paint-resistant modified masterbatch are: polycaprolactam and epoxy resin are uniformly mixed in a mass ratio of 85-95:15-5, melt-extruded at 240-260° C., cooled and granulated to obtain the paint-resistant modified masterbatch.

[0024] In step S2, the temperature of the twin-screw extruder for melt extrusion from the feed port to the die is set to: 180-200°C in zones 1-2, 230-260°C in zones 3-5, and 250-270°C in zones 6-10. The materials are melted and mixed under the conveying, shearing and mixing of the screw; the screw speed is 300-700 r / min.

[0025] The present invention also provides an application of the high heat-resistant and flame-retardant PC material in the fields of wall switches for spray painting and medical equipment housings.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The present invention provides a highly heat-resistant and flame-retardant PC material with excellent paint resistance. The PC material is mainly composed of components such as polycarbonate, a paint-resistant modified masterbatch, a compatibilizer, and a flame retardant. The paint resistance is achieved by cross-linking the amino groups of the polycaprolactam in the paint-resistant modified masterbatch with the highly active epoxy groups in the epoxy resin.

[0028] (2) The use of a specific compatibilizer not only improves the compatibility of polycarbonate with the paint-resistant modified masterbatch and enhances the toughness of the material, but also improves the paint resistance of polycarbonate; the addition of the flame retardant compensates for the effects of the paint-resistant modified masterbatch and the compatibilizer on the flame retardancy of polycarbonate;

[0029] (3) The PC material of the present invention is particularly suitable for applications such as painted wall switches and medical equipment housings. DETAILED DESCRIPTION

[0030] The present invention is described in detail below with reference to specific embodiments. The following examples are implemented under the premise of the technical solution of the present invention, provide detailed implementation methods and specific operating procedures, and will help those skilled in the art to further understand the present invention. It should be pointed out that the protection scope of the present invention is not limited to the following embodiments, and a number of adjustments and improvements made under the premise of the concept of the present invention all fall within the protection scope of the present invention.

[0031] The paint-resistant modified masterbatch used in the examples and comparative examples of the present invention is self-made by Kumho Sunlight, and the specific steps are as follows: Guangzhou Xinhui Meida M2500 and Nanya NPES-907 are mixed evenly in a mass ratio of 90:10, melt-extruded at 250°C, cooled and granulated to obtain the paint-resistant modified masterbatch.

[0032] Example 1

[0033] A highly heat-resistant and flame-retardant PC material with excellent paint resistance, the method comprising the following steps:

[0034] (1) Weigh the raw materials according to the following weight parts:

[0035]

[0036] The polycarbonate is Lotte PC1100; the paint-resistant modified masterbatch is self-made by Kumho Sunny; the compatibilizer is 5805-SL from Sunny; the flame retardant is BC-58 from Lanxess; the antioxidants are hindered phenol antioxidant (1076) and antioxidant 168 tris (2,4-di-tert-butylphenyl) phosphite (mass ratio 1:1), commercially available; the lubricant is PETS, commercially available;

[0037] (2) The above raw materials are placed in a high-speed mixer according to the proportion and stirred. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder from the feed port to the die is set as follows: 180-200°C for zone 1-2, 230-260°C for zone 3-5, and 250-270°C for zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and mixed. The screw is melted and extruded at a speed of 500r / min, cooled and granulated to obtain a high heat-resistant and flame-retardant PC material with excellent paint resistance.

[0038] Example 2

[0039] A highly heat-resistant and flame-retardant PC material with excellent paint resistance, the method comprising the following steps:

[0040] (1) Weigh the raw materials according to the following weight parts:

[0041]

[0042] The polycarbonate is Lotte PC1100; the paint-resistant modified masterbatch is self-made by Kumho Sunny; the compatibilizer is preferably 5805-SL from Sunny; the flame retardant is preferably BC-58 from Lanxess; the antioxidants are hindered phenol antioxidant (1076) and antioxidant 168 tris (2,4-di-tert-butylphenyl) phosphite (mass ratio 1:1), which are commercially available; the lubricant is PETS, which is commercially available;

[0043] (2) The above raw materials are placed in a high-speed mixer according to the proportion and stirred. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder from the feed port to the die is set as follows: 180-200°C for zone 1-2, 230-260°C for zone 3-5, and 250-270°C for zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and mixed. The screw is melted and extruded at a speed of 500r / min, cooled and granulated to obtain a high heat-resistant and flame-retardant PC material with excellent paint resistance.

[0044] Example 3

[0045] A highly heat-resistant and flame-retardant PC material with excellent paint resistance, the method comprising the following steps:

[0046] (1) Weigh the raw materials according to the following weight parts:

[0047]

[0048] The polycarbonate is Lotte PC1100; the paint-resistant modified masterbatch is self-made by Kumho Sunny; the compatibilizer is preferably 5805-SL from Sunny; the flame retardant is preferably BC-58 from Lanxess; the antioxidants are hindered phenol antioxidant (1076) and antioxidant 168 tris (2,4-di-tert-butylphenyl) phosphite (mass ratio 1:1), which are commercially available; the lubricant is PETS, which is commercially available;

[0049] (2) The above raw materials are placed in a high-speed mixer according to the proportion and stirred. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder from the feed port to the die is set as follows: 180-200°C for zone 1-2, 230-260°C for zone 3-5, and 250-270°C for zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and mixed. The screw is melted and extruded at a speed of 500r / min, cooled and granulated to obtain a high heat-resistant and flame-retardant PC material with excellent paint resistance.

[0050] Example 4

[0051] A highly heat-resistant and flame-retardant PC material with excellent paint resistance, the method comprising the following steps:

[0052] (1) Weigh the raw materials according to the following weight parts:

[0053]

[0054] The polycarbonate is Lotte PC1100; the paint-resistant modified masterbatch is self-made by Kumho Sunny; the compatibilizer is preferably 5805-SL from Sunny; the flame retardant is preferably BC-58 from Lanxess; the antioxidants are hindered phenol antioxidant (1076) and antioxidant 168 tris (2,4-di-tert-butylphenyl) phosphite (mass ratio 1:1), which are commercially available; the lubricant is PETS, which is commercially available;

[0055] (2) The above raw materials are placed in a high-speed mixer according to the proportion and stirred. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder from the feed port to the die is set as follows: 180-200°C for zone 1-2, 230-260°C for zone 3-5, and 250-270°C for zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and mixed. The screw is melted and extruded at a speed of 500r / min, cooled and granulated to obtain a high heat-resistant and flame-retardant PC material with excellent paint resistance.

[0056] Example 5

[0057] A highly heat-resistant and flame-retardant PC material with excellent paint resistance, the method comprising the following steps:

[0058] (1) Weigh the raw materials according to the following weight parts:

[0059]

[0060] The polycarbonate is Lotte PC1100; the paint-resistant modified masterbatch is self-made by Kumho Sunny; the compatibilizer is preferably 5805-SL from Sunny; the flame retardant is preferably BC-58 from Lanxess; the antioxidants are hindered phenol antioxidant (1076) and antioxidant 168 tris (2,4-di-tert-butylphenyl) phosphite (mass ratio 1:1), which are commercially available; the lubricant is PETS, which is commercially available;

[0061] (2) The above raw materials are placed in a high-speed mixer according to the proportion and stirred. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder from the feed port to the die is set as follows: 180-200°C for zone 1-2, 230-260°C for zone 3-5, and 250-270°C for zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and mixed. The screw is melted and extruded at a speed of 500r / min, cooled and granulated to obtain a high heat-resistant and flame-retardant PC material with excellent paint resistance.

[0062] Example 6

[0063] A highly heat-resistant and flame-retardant PC material with excellent paint resistance, the method comprising the following steps:

[0064] (1) Weigh the raw materials according to the following weight parts:

[0065]

[0066]

[0067] The polycarbonate is Lotte PC1100; the paint-resistant modified masterbatch is self-made by Kumho Sunny; the compatibilizer is preferably 5805-SL from Sunny; the flame retardant is preferably BC-58 from Lanxess; the antioxidants are hindered phenol antioxidant (1076) and antioxidant 168 tris (2,4-di-tert-butylphenyl) phosphite (mass ratio 1:1), which are commercially available; the lubricant is PETS, which is commercially available;

[0068] (2) The above raw materials are placed in a high-speed mixer according to the proportion and stirred. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder from the feed port to the die is set as follows: 180-200°C for zone 1-2, 230-260°C for zone 3-5, and 250-270°C for zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and mixed. The screw is melted and extruded at a speed of 500r / min, cooled and granulated to obtain a high heat-resistant and flame-retardant PC material with excellent paint resistance.

[0069] Comparative Example 1

[0070] A highly heat-resistant and flame-retardant PC material, the method comprising the following steps:

[0071] (1) Weigh the raw materials according to the following weight parts:

[0072]

[0073] The polycarbonate is Lotte PC1100; the compatibilizer is preferably 5805-SL from Nichisei; the flame retardant is preferably BC-58 from Lanxess; the antioxidants are hindered phenol antioxidant (1076) and antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (mass ratio 1:1), which are commercially available; the lubricant is PETS, which is commercially available;

[0074] (2) The above raw materials are placed in a high-speed mixer according to the proportion and stirred. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder from the feed port to the die is set to: 180-200°C for zone 1-2, 230-260°C for zone 3-5, and 250-270°C for zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and mixed, and melt extrusion is carried out at a screw speed of 500r / min. The materials are cooled and granulated to obtain a highly heat-resistant and flame-retardant PC material.

[0075] Comparative Example 2

[0076] A highly heat-resistant and flame-retardant PC material, the method comprising the following steps:

[0077] (1) Weigh the raw materials according to the following weight parts:

[0078]

[0079]

[0080] The polycarbonate is Lotte PC1100; the flame retardant is preferably BC-58 from Lanxess; the antioxidants are hindered phenol antioxidant (1076) and antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (mass ratio 1:1), which are commercially available; the lubricant is PETS, which is commercially available;

[0081] (2) The above raw materials are placed in a high-speed mixer according to the proportion and stirred. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder from the feed port to the die is set to: 180-200°C for zone 1-2, 230-260°C for zone 3-5, and 250-270°C for zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and mixed, and melt extrusion is carried out at a screw speed of 500r / min. The materials are cooled and granulated to obtain a highly heat-resistant and flame-retardant PC material.

[0082] Comparative Example 3

[0083] A flame retardant PC / ABS material with excellent paint resistance, the method comprising the following steps:

[0084] (1) Weigh the raw materials according to the following weight parts:

[0085]

[0086] The polycarbonate is Lotte PC1100; the ABS is Takahashi 8391; the flame retardant is preferably BC-58 from Lanxess; the antioxidants are hindered phenol antioxidant (1076) and antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (mass ratio 1:1), which are commercially available; the lubricant is PETS, which is commercially available;

[0087] (2) The above raw materials are placed in a high-speed mixer according to the proportion and stirred. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder from the feed port to the die is set to: 180-200°C for zone 1-2, 230-260°C for zone 3-5, and 250-270°C for zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and mixed, and melt extrusion is carried out at a screw speed of 500r / min. The materials are cooled and granulated to obtain a flame-retardant PC / ABS material with excellent paint resistance.

[0088] Comparative Example 4

[0089] This comparative example prepared a flame retardant PC material with excellent paint resistance, the steps are basically the same as in Example 3, except that: no paint resistance modified masterbatch is used, and an equal amount of polycaprolactam is used.

[0090] Comparative Example 5

[0091] In this comparative example, a flame-retardant PC material with excellent paint resistance was prepared. The steps were basically the same as those in Example 3, except that the paint-resistant modified masterbatch was not used and an equal amount of epoxy resin was used.

[0092] Comparative Example 6

[0093] In this comparative example, a flame-retardant PC material with excellent paint resistance was prepared. The steps were basically the same as those in Example 3, except that no paint-resistant modified masterbatch was prepared, and the polycaprolactam and epoxy resin were directly mixed and stirred with the other components.

[0094] The components of each example and comparative example are shown in Table 1

[0095] Table 1

[0096]

[0097] The above examples were tested for performance according to the standards in Table 2:

[0098] Table 2

[0099] performance Test standards Test conditions unit Izod notched impact strength GB / T 1843 23℃ <![CDATA[3j / m 2 ]]> Heat-resistant ball pressure temperature GB / T 5169 / ℃ Glow wire performance IEC 60695-2-11 870℃81.5mm / Paint resistance (impact performance) See Note 1

[0100] Note 1: The materials of Examples 1 to 6 and Comparative Examples 1 to 3 were injection molded into notched impact bars according to GB / T 1843. The bars were immersed in ethyl acetate for 5 minutes, immediately removed and rinsed with deionized water, dried at 80°C for 1 hour, and naturally cooled for 24 hours before testing the notched cantilever beam impact strength.

[0101] The performance of each example product is shown in Table 3:

[0102] Table 3

[0103]

[0104] From the experimental results of Comparative Example 1-4, it can be seen that with the increase of the content of the paint-resistant modified masterbatch, the paint resistance is improved. This may be due to the reaction between the amino group in the polycaprolactam in the paint-resistant modified masterbatch and the epoxy group in the epoxy resin. When the addition amount is 9 phr, further increasing the content of the paint-resistant modified masterbatch does not significantly improve the performance. From the experimental data of Comparative Examples 3, 5, and 6, it can be seen that with the increase of the compatibilizer content, the paint resistance is better. This may be because the compatibilizer not only plays a compatibilizing role to improve the toughness of the material, but also can further improve the material's resistance to spray paint. Comparing Example 1 with Comparative Examples 1-3, the paint resistance without the use of the paint-resistant modified masterbatch and the compatibilizer is very poor. The paint resistance of the paint-resistant modified masterbatch and the compatibilizer is very excellent, which is significantly better than the paint-resistant flame-retardant PC / ABS solution.

[0105] The above is a detailed introduction to the preparation method of a highly heat-resistant and flame-retardant PC material with excellent paint resistance provided by the present invention. Specific examples are used herein to illustrate the principles and implementation of the present invention. For those skilled in the art, several improvements can be made without departing from the principles of the present invention, and these improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A highly heat-resistant and flame-retardant PC material with excellent paint resistance, characterized in that: The high heat-resistant and flame-retardant PC material comprises the following components in parts by weight: The paint-resistant modified masterbatch is prepared by extruding and granulating a mixed resin including polycaprolactam and epoxy resin, wherein the mass ratio of polycaprolactam to epoxy resin is 85-95:15-5; The compatibilizer is maleic anhydride grafted polyolefin, and the maleic anhydride grafted polyolefin includes one or more of maleic anhydride grafted polypropylene and maleic anhydride grafted polyethylene.

2. The high heat-resistant and flame-retardant PC material according to claim 1, characterized in that: The polycarbonate has a number average molecular weight of 18,000-36,000 g / mol and a melt flow rate of 3-20 g / 10 min under the conditions of 300° C. / 1.23 g.

3. The high heat-resistant and flame-retardant PC material according to claim 1, characterized in that: The flame retardant includes one or more of brominated polycarbonate, bromotriazine, brominated epoxy, and tetrabromobisphenol A.

4. The high heat-resistant and flame-retardant PC material according to claim 1, characterized in that: The antioxidant includes one or more of the commercially available antioxidant 1076, antioxidant 168, antioxidant 245, and antioxidant 1010.

5. The high heat-resistant and flame-retardant PC material according to claim 1, characterized in that: The lubricant includes one or more of pentaerythritol ester, silicone powder, and ethylene bisstearamide.

6. A method for preparing a highly heat-resistant and flame-retardant PC material according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Weigh the raw materials according to the following weight parts: S2. Mix the above raw materials according to the proportions, stir them, melt and extrude them after mixing them evenly, and cool and granulate them to obtain the high heat-resistant and flame-retardant PC material.

7. The preparation method according to claim 6, characterized in that In step S2, the temperatures of the twin-screw extruder for melt extrusion from the feed port to the die are set to: 180-200°C in zone 1-2, 230-260°C in zone 3-5, and 250-270°C in zone 6-10.

8. Use of the highly heat-resistant and flame-retardant PC material according to claim 1 in the fields of spray-painted wall switches and medical equipment housings.

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