High-flame-retardant burnthrough-resistant PC alloy and preparation method thereof

Abstract

The invention provides a high-flame-retardant burnthrough-resistant PC alloy and a preparation method thereof. The PC alloy comprises the following components: branched PC resin with a special blocking rate, 4-10 parts of aryl p-toluenesulfonate and glycidyl ester, wherein the blocking rate of the branched PC resin is 85-95%. The heat resistance, melt strength and burnthrough resistance of the PC alloy are remarkably improved, the heat deformation temperature is increased to 132 DEG C from 122 DEG C, the needle flame S.2 burnthrough time is increased to 150 s or above from 15 s, high flame retardance and burnthrough resistance of a PC product are achieved, and meanwhile the original mechanical performance and thermal performance of PC resin are not affected.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of polycarbonate, and particularly relates to a high-flame-retardant burn-through-resistant PC alloy and a preparation method thereof. BACKGROUND

[0002] Polycarbonate (PC) is a very widely used engineering plastic, because it has a vertical burning V2 flame retardant level, and is widely used in wall opening, lighting, converter, adapter and other fields. However, with the continuous iteration and upgrading of products, the industry's increasing demand for safety has also put forward higher requirements for the flame retardant performance of materials. In addition to the original 1.5mm-850℃ glowing wire and 1.5mm-V0, new safety needle flame S.2 performance requirements have been added, focusing on adjusting the burn-through resistance of the material. However, the heat resistance and melt strength of the current PC material cannot meet the S.2 requirements, and the commercially available products that improve the flame retardant performance by improving the shrinkage performance are also prone to shrinkage and form perforations in the S.2 test. Therefore, it is very important to achieve the original flame retardant performance while significantly improving the burn-through resistance of the PC material.

[0003] CN119875342A discloses a burn-through-resistant PC composite material and a preparation method thereof, which forms a B-Si glass protection layer by adding a bromine flame retardant, a silicon flame retardant and a boron flame retardant, thereby improving the melt strength of the PC composite material, preventing burn-through and having excellent burn-through resistance. However, bromine flame retardants have a greater impact on the environment, and boron flame retardants have a greater impact on the mechanical properties of PC, making it difficult to be commercialized on a large scale. CN105246976B discloses a filled polycarbonate composition, which adds glass fibers, aluminum oxide particles and wollastonite particles to the polycarbonate composition to improve the burn-through resistance of the material. However, the introduction of a large amount of inorganic substances has a great impact on the mechanical properties and processing fluidity of the PC material, greatly limiting the application of the final product.

[0004] In summary, the current art cannot simultaneously improve the burn-through resistance and glowing wire performance of PC resin through modification technology without affecting the original performance of the resin. SUMMARY

[0005] In view of the deficiencies in the prior art, one of the purposes of the present application is to provide a high-flame-retardant burn-through-resistant PC alloy, which significantly improves the heat resistance, melt strength and burn-through resistance of the PC alloy without affecting the original performance of the resin.

[0006] To achieve the above-mentioned purposes of the application, the following technical solutions are adopted:

[0007] A PC alloy, which is prepared from the following components in parts by mass:

[0008] branched PC resin with special end-capping rate 85-95 parts, preferably 90-94 parts,

[0009] p-toluene sulfonic acid aryl ester 4-10 parts, preferably 6-8 parts;

[0010] glycidyl ester 0.65-3 parts, preferably 1-2 parts.

[0011] In the present application, the branched PC and p-toluene sulfonic acid aryl ester resin are cross-linked by introducing glycidyl ester, which greatly improves the heat resistance and melt strength of the PC resin; at the same time, the ester bond of glycidyl ester is broken first during combustion, which makes the cross-linked product produce SO2 rapidly at high temperature to promote the formation of a dense carbon layer, thereby improving the burn-through resistance of the PC alloy. The method significantly improves the heat resistance, melt strength, and burn-through resistance of the PC alloy without affecting the original performance of the resin. The related reactions of the branched PC resin with special end-capping rate forming the alloy are shown in the accompanying drawings Figure 1 .

[0012] In an embodiment of the present application, the PC base resin of the branched PC resin with special end-capping rate is aromatic polycarbonate, preferably bisphenol A type polycarbonate.

[0013] In an embodiment of the present application, the branched PC resin with special end-capping rate is end-capped by p-toluene sulfonic acid aryl ester decomposition products; preferably, the end-capping rate of the branched PC resin is 85-95%, preferably 88-92%.

[0014] In an embodiment of the present application, the p-toluene sulfonic acid aryl ester is a compound with a carbon number of 13-16, preferably one or more of p-toluene sulfonic acid benzyl ester, o-methyl p-toluene sulfonic acid phenyl ester, and p-toluene sulfonic acid phenyl ester.

[0015] In an embodiment of the present application, the glycidyl ester is a glycidyl ester with two or more epoxy groups, preferably the glycidyl ester has a molecular weight of 200-2000, more preferably 250-1000.

[0016] In an embodiment of the present application, the PC alloy comprises an antioxidant, and the antioxidant is one or more of hindered phenol, benzofuran, and hydroxylamine antioxidants, preferably hindered phenol, more preferably one or more of Irganox 1076, Irganox 1010, and Irganox 168; preferably, the mass fraction of the antioxidant is 0.05-1 parts, preferably 0.1-0.3 parts.

[0017] In an embodiment of the present application, the PC alloy contains a lubricant, the lubricant is one or more of fatty acid esters, saturated hydrocarbons, polyolefin waxes, montanic acid and its derivatives, organosilicon and silicone powder, preferably fatty acid esters; preferably, the mass fraction of the lubricant is 0.3-1 parts, preferably 0.5-0.8 parts.

[0018] Another object of the present application is to provide a preparation method of a PC alloy.

[0019] A preparation method of a PC alloy, the preparation method is used for preparing the PC alloy described above, and the preparation method comprises the following steps:

[0020] S1: branched PC resins with special end-capping rate, p-toluenesulfonic acid aryl ester, antioxidant, lubricant are fed from the main feeding of the extruder;

[0021] S2: glycidyl ester is fed from the side feeding of the extruder;

[0022] S3: the extruder is extruded and granulated to obtain a PC alloy material.

[0023] In an embodiment of the present application, the temperature of the extruder in the extruder extrusion granulation of S3 is 250-300℃, and the screw rotation speed is 300-800 rpm.

[0024] Still another object of the present application is to provide a use of a PC alloy material.

[0025] A use of a PC alloy material, the material is the PC alloy described above, or is a PC alloy prepared by the preparation method described above, and the material is used for a high flame-retardant and burn-through-resistant PC product, preferably a PC product with new regulatory needle flame S.2 flame-retardant requirements.

[0026] Compared with the prior art, the scheme of the present application has the following positive effects:

[0027] The heat resistance, melt strength and burn-through resistance of the PC alloy are significantly improved (the heat distortion temperature is increased from 122℃ to 132℃, and the needle flame S.2 burn-through time is increased from 15s to more than 150s), and the high flame-retardant and burn-through-resistant PC product is realized without affecting the original mechanical properties and thermal properties of the PC resin. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A schematic diagram of the reaction of forming an alloy of branched PC resins with special end-capping rate. DETAILED DESCRIPTION

[0029] The present application will be further described below through specific examples, and the examples described in the present application are only used to illustrate the present application and do not limit the scope of the present application.

[0030] The main raw material sources in the examples and comparative examples are shown in Table 1 below:

[0031] Table 1 Raw material source information

[0032]

[0033] Other raw materials and reagents were purchased commercially unless otherwise specified.

[0034] In the examples and comparative examples, the performance test parameters and corresponding test methods of the PC alloy are as follows:

[0035] The processing equipment used is: a twin-screw extruder: Krausmafi ZE28 x 40D BD, length-diameter ratio of 40, screw diameter of 28 mm;

[0036] The performance test parameters and corresponding test methods of the PC alloy are as follows:

[0037] New safety needle flame S.2: tested according to GB / T 5169.5-2020 "Electrical and electronic products - Fire hazard tests - Part 5: Test flame needle flame test method";

[0038] Thermal deformation temperature (℃): tested according to ISO 75 / B "Plastics - Heat distortion temperature test method", heating rate of 120℃ / h;

[0039] Impact strength (MPa): tested according to ISO 180-2000 "Determination of Izod impact strength of plastics", test temperature 23℃, pendulum 5.5J.

[0040] Infrared test: tested according to GB / T 6040 "General infrared spectroscopy analysis method", test equipment Thermofisher, scanning range 400-4000cm -1 , scanning times 32 times.

[0041] Example 1

[0042] The high flame-retardant and burn-through-resistant PC alloy was prepared using the following raw material formulation:

[0043]

[0044] The preparation method is:

[0045] a. The branched PC resin 2030B-90 with special end-capping rate, p-hydroxy diphenyl sulfone, antioxidant, lubricant were put into the main feeding of the extruder;

[0046] b. 4,5-epoxyhexane-1,2-diglycidyl ester was put into the fourth segment of the side feeding of the extruder;

[0047] c. extruding and granulating the extruder to obtain the PC alloy material. The extrusion conditions are: controlling the vacuum degree of the vacuum device of the metering section of the twin-screw to 0.08 MPa, the screw rotation speed to 300 rpm, and the screw temperature from the discharge port to the die head to be set in sections as 250℃, 270℃, 270℃, 270℃, 270℃, 260℃, 260℃, 260℃; cooling the extruded material in the water tank of the extruder at 50℃ and cutting the material into particles to obtain the PC alloy.

[0048] The PC alloy can be seen by infrared analysis that: there is no epoxy symmetric stretching vibration peak at 910-880 cm -1 , no asymmetric stretching vibration peak of epoxy ring at 1260-1230 cm -1 , no glycidyl ester ring epoxy group reaction; there is the stretching vibration of aliphatic ether bond at 1120-1080 cm -1 , the ester bond offset vibration peak appears at 1770-1740 cm -1 (the introduction of new ester bond leads to the shift of the carbonate group peak), and it can be seen that the polycarbonate reacts with the glycidyl ester epoxy group; in addition, there are strong absorption peaks of sulfonic acid group S=O at 1350-1330 cm -1 (asymmetric) and 1160-1140 cm -1 (symmetric), indicating the introduction of sulfonic acid group.

[0049] Example 2

[0050] The following raw material formula is used to prepare the high-flame-retardant and burn-through-resistant PC alloy:

[0051]

[0052] The preparation method is:

[0053] a. The branched PC resin 2030B-85 with a specific end-capping rate, o-hydroxybenzene sulfone, antioxidant, and lubricant are fed from the main feeder of the extruder;

[0054] b. The 4,5-epoxyhexane-1,2-dicarboxylic acid diglycidyl ester is fed from the fourth section of the side feeder of the extruder;

[0055] c. The extruder is extruded and granulated to obtain the PC alloy material;

[0056] d. The extrusion conditions are: controlling the vacuum degree of the vacuum device of the metering section of the twin-screw to 0.08 MPa, the screw rotation speed to 500 rpm, and the screw temperature from the discharge port to the die head to be set in sections as 255℃, 280℃, 280℃, 280℃, 280℃, 265℃, 265℃, 265℃;

[0057] e. The extruded material is cooled in the extruder tank at 50°C, and pelletized to obtain the PC alloy.

[0058] Example 3

[0059] The high flame-retardant and burn-through-resistant PC alloy is prepared using the following raw material formulation:

[0060]

[0061] The preparation method is as follows:

[0062] a. The branched PC resin 2030B-95 with a specific end-capping rate, hydroxybenzodisulfone, antioxidant, and lubricant are fed from the main feeder of the extruder;

[0063] b. The 1,2-cyclohexane dicarboxylic acid diglycidyl ester is fed from the fourth section of the side feeder of the extruder;

[0064] c. The extruder is extruded and pelletized to obtain the PC alloy material;

[0065] d. The extrusion conditions are as follows: the vacuum degree of the double-screw metering section vacuum device is controlled at 0.08 MPa, the screw rotation speed is 800 rpm, and the screw temperature is set in sections from the discharge port to the die head as follows: 260°C, 300°C, 300°C, 300°C, 300°C, 270°C, 270°C, and 270°C;

[0066] e. The extruded material is cooled in the extruder tank at 50°C, and pelletized to obtain the PC alloy.

[0067] Comparative Example 1

[0068] Compared with Example 1, the difference is that the branched PC resin 2030B-99 with a conventional end-capping rate (end-capping rate 99%) is directly added as the main feeder instead of the branched PC resin 2030B-90 with a special end-capping rate.

[0069] Comparative Example 2

[0070] Compared with Example 1, the difference is that the p-toluenesulfonic acid and benzyl alcohol with the same mass fraction as the p-toluenesulfonic acid benzyl ester are directly added as the main feeder instead of the p-toluenesulfonic acid benzyl ester, and the addition ratio of the p-toluenesulfonic acid to the benzyl alcohol is 1:1.

[0071] Comparative Example 3

[0072] Compared with Example 1, the difference is that the p-toluenesulfonic acid benzyl ester is not added.

[0073] Comparative Example 4

[0074] Compared with Example 1, the difference is that the glycidyl ester is not added.

[0075] The PC alloy materials obtained from Examples 1-3 (S1-S3) and Comparative Examples 1-5 (D1-D4) were subjected to injection molding evaluation in an injection molding machine, the screw temperature was set to 300℃, and the samples after injection molding were subjected to performance test, and the relevant performance was as shown in Table 2.

[0076] Table 2 Product performance test results of Examples 1-3 (S1-S3) and Comparative Examples 1-5 (D1-D5)

[0077]

[0078] As can be seen from Comparative Examples 1-5 and Examples 1-3, the PC alloy in the examples has higher burn-through resistance and thermal performance, and the mechanical properties of the PC alloy are also well maintained. However, the comparative examples have the disadvantages of easy burn-through and decreased impact strength.

[0079] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, without departing from the method of the present application, a number of improvements and supplements can also be made, which should also be considered as the protection scope of the present application.

Claims

1. A PC alloy, characterized in that, The PC alloy is prepared by comprising the following components in parts by weight: 85-95 parts, preferably 90-94 parts, of branched PC resin with a special end-capping ratio. 4-10 parts of p-toluenesulfonate aryl ester, preferably 6-8 parts; 0.65-3 parts of glycidyl ester, preferably 1-2 parts.

2. The PC alloy according to claim 1, characterized in that, The PC matrix resin of the branched PC resin with the special end-capping ratio is an aromatic polycarbonate, preferably a bisphenol A type polycarbonate. And / or, the branched PC resin with the special end-capping ratio is end-capped by the decomposition product of aryl p-toluenesulfonate. Preferably, the branched PC resin has a capping rate of 85-95%, more preferably 88-92%.

3. The PC alloy according to claim 1 or 2, characterized in that, The aryl p-toluenesulfonate compound having 13 to 16 carbon atoms is preferably one or more of methyl p-toluenesulfonate, o-methyl p-toluenesulfonate, and p-toluenesulfonate.

4. The PC alloy according to any one of claims 1-3, characterized in that, The glycidyl ester is a glycidyl ester with two or more epoxy groups, preferably a glycidyl ester with a molecular weight of 200-2000, more preferably 250-1000.

5. The PC alloy according to any one of claims 1-4, characterized in that, The PC alloy contains an antioxidant, which is one or more of hindered phenolic, benzofuran, and hydroxylamine antioxidants, preferably hindered phenolic, and more preferably one or more of Irganox 1076, Irganox 1010, and Irganox 168; preferably, the antioxidant is 0.05-1 part by weight, more preferably 0.1-0.3 parts by weight.

6. The PC alloy according to any one of claims 1-5, characterized in that, The PC alloy contains a lubricant, which is one or more of fatty acid esters, saturated hydrocarbons, polyolefin waxes, lignite acid and its derivatives, organosilicon and silicone powders, preferably fatty acid esters; Preferably, the lubricant is present in a mass fraction of 0.3-1 parts, more preferably 0.5-0.8 parts.

7. A method for preparing a PC alloy, said method being used to prepare the PC alloy according to any one of claims 1-6, characterized in that, The preparation method includes the following steps: S1: The branched PC resin with a special end-capping ratio, aryl p-toluenesulfonate, antioxidant, and lubricant are fed into the main feeder of the extruder; S2: Add glycidyl ester from the extruder side feeder; S3: Extrusion granulation using an extruder to obtain PC alloy material.

8. The preparation method according to claim 7, characterized in that, The extrusion granulation temperature of the extruder described in S3 is 250-300℃, and the screw speed is 300-800rpm.

9. The use of a PC alloy material, wherein the material is the PC alloy according to any one of claims 1-6, or is a PC alloy prepared by the preparation method according to claim 7 or 8, characterized in that, The material is used in PC products with high flame retardancy and burn-through resistance, and is preferably used in PC products that meet the new safety standard needle flame S.2 flame retardancy requirements.

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