A self-lubricating high-toughness flame-retardant SAS composition, and a preparation method and application thereof

Abstract

The application discloses a self-lubricating high-toughness flame-retardant SAS composition and a preparation method and application thereof. The SAS composition adopts SAS resin as a base resin, selects expanded graphite with an expansion ratio of 220-430 or a phosphoric acid ester compound as a flame retardant, and the expanded graphite expands rapidly during heating to form a hollow carbon layer, so that good flame retardation can be achieved with less amount of the flame retardant, and the SAS composition prepared has good toughness; meanwhile, the expanded graphite has a lamellar structure and can slide between the lamellas, so that the friction coefficient of the SAS composition can be reduced, the SAS composition has good self-lubricating performance, and the service life of the composition is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of modified engineering plastics technology, and more specifically, relates to a self-lubricating, high-toughness, flame-retardant SAS composition, its preparation method, and its application. Background Technology

[0002] ABS resin is widely used in household appliances, textiles, and building materials due to its good mechanical and processing properties. However, its solvent resistance is poor, limiting its application in environments with harsh solvent requirements, such as kitchen appliances that frequently use cooking oils and detergents. Styrene-acrylonitrile-silicone resin (SAS resin) has better solvent resistance than ABS resin.

[0003] As consumers increasingly prioritize safety, household appliances require flame-retardant modifications to their materials. However, directly adding flame retardants to SAS resin reduces the material's toughness, increases the coefficient of friction, and affects its lifespan. Furthermore, a higher coefficient of friction leads to increased energy consumption. Therefore, there is a need in this field to develop a flame-retardant SAS composition that simultaneously possesses good toughness and a low coefficient of friction. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects or deficiencies in the prior art and provide a self-lubricating, high-toughness, flame-retardant SAS composition with good flame-retardant properties, as well as good toughness and self-lubricating properties.

[0005] Another object of the present invention is to provide a method for preparing the self-lubricating, high-toughness, flame-retardant SAS composition.

[0006] Another object of the present invention is to provide the application of the self-lubricating, high-toughness, flame-retardant SAS composition.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] A self-lubricating, high-toughness, flame-retardant SAS composition comprising the following components in parts by weight:

[0009]

[0010] The total amount of flame retardant A and flame retardant B is 15% to 20% of the SAS composition.

[0011] Flame retardant A is expanded graphite with an expansion ratio of 220 to 430 times; flame retardant B is a phosphate ester compound.

[0012] In this invention, by selecting SAS resin as the matrix resin and using expanded graphite with an expansion ratio of 220-430 times, or in combination with phosphate ester compounds, as a flame retardant, the resulting flame-retardant SAS composition exhibits good flame-retardant properties, as well as good toughness and self-lubricating properties. The inventors speculate that this may be because expanded graphite expands rapidly upon heating during combustion, forming a hollow carbon layer, thus achieving a higher flame-retardant rating with a smaller amount compared to other flame retardants. If the expansion ratio of expanded graphite is too small, fewer carbon layers are formed during heating, resulting in a poorer flame-retardant effect; if the expansion ratio of expanded graphite is too large, the formed carbon layer is not dense enough, leading to a poorer flame-retardant effect.

[0013] Furthermore, the addition of phosphate esters to the system allows them to decompose upon heating, producing phosphoric acid and metaphosphoric acid. These catalyze the carbonization of the material and combine with the carbon layers of expanded graphite, making them more compact. The inert gases generated by the phosphate esters and matrix resin during heating fill the hollow voids in the carbon layers, further isolating oxygen and inhibiting combustion. The addition of phosphate esters allows for better flame retardancy with a smaller amount of flame retardant. Simultaneously, the layered structure of expanded graphite allows for slippage between layers, reducing the coefficient of friction in the SAS composition and providing good self-lubricating properties.

[0014] In this invention, the expansion ratio of the expanded graphite is 220 to 430 times, for example, but not limited to, 230 times, 240 times, 250 times, 260 times, 270 times, 280 times, 290 times, 300 times, 310 times, 320 times, 330 times, 340 times, 350 times, 360 times, 370 times, 380 times, 390 times, 400 times, 410 times, 420 times, etc., all of which can achieve the present invention. Furthermore, the expansion ratio of the expanded graphite is 275 to 370 times.

[0015] Furthermore, the mass ratio of flame retardant A to flame retardant B is (1-2):1. Using flame retardants A and B in combination allows the resulting SAS composition to exhibit better overall performance with a smaller total amount of flame retardants.

[0016] It should be noted that the content of SAS resin in the SAS composition of the present invention is not less than 30 wt.%.

[0017] Furthermore, the melt flow rate of the SAS resin at 220°C and a 10kg load is 2–25 cm⁻¹. 3 / 10min.

[0018] Specifically, the standard for determining the melt flow rate of the SAS resin is ISO 1133-1-2011.

[0019] In a specific embodiment, the acrylonitrile content in the SAS resin is 15-35 wt.%.

[0020] Furthermore, the expansion ratio of the expanded graphite is determined by the volumetric method.

[0021] Specifically, the volume change of expanded graphite before and after expansion is measured. The ratio of the volume after expansion (V) to the volume before expansion (V0) is the expansion ratio (V / V0). The volume after expansion is determined by placing the sample in a box-type resistance furnace at 950-1000℃ without closing the furnace door until it stops expanding, then immediately removing it, pouring it into a graduated cylinder, and reading the volume of the sample after expansion, which is recorded as V. Three samples are taken from each group for measurement, and the average value is taken.

[0022] Furthermore, the expanded graphite can be purchased or made in-house.

[0023] In a specific embodiment, the expanded graphite is prepared as follows:

[0024] Natural graphite was placed in a mixture of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1, and after stirring, washing, and drying, it was treated at 850–1150℃ for 10–20 seconds.

[0025] Specifically, the higher the processing temperature, the greater the expansion ratio of the expanded graphite; the longer the processing time, the greater the expansion ratio of the expanded graphite.

[0026] Furthermore, the expansion ratio of the expanded graphite is 330 to 370 times.

[0027] Specifically, the phosphate ester compound is one or a mixture of several of resorcinol bis(diphenyl phosphate), polybisphenol A bis(diphenyl phosphate), or triphenyl phosphate.

[0028] Furthermore, the toughening agent is one or more of ASA-type high-polymer powder, butadiene-type high-polymer powder, or MBS.

[0029] Furthermore, the compatibilizer is styrene-N-phenylmaleimide.

[0030] Furthermore, the self-lubricating, high-toughness, flame-retardant SAS composition comprises the following components in parts by weight:

[0031]

[0032] Furthermore, the SAS composition further includes 0.5 to 10 parts of inorganic filler and 0.1 to 3 parts of additives.

[0033] In this invention, commonly used inorganic fillers can be selected according to existing technology, such as, but not limited to, one or more of talc, barium sulfate or kaolin.

[0034] Furthermore, the additive is one or more of the following: lubricant, antioxidant, colorant, or weathering agent.

[0035] In this invention, commonly used antioxidants can be selected according to existing technology, such as, but not limited to, one or more of hindered phenolic antioxidants, phosphite antioxidants, metal alkyl thiophosphate antioxidants, carbamic acid antioxidants, and organosulfur antioxidants.

[0036] Specifically, the hindered phenolic antioxidant is one or more of N,N'-hexamethylene bis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide) (Irganox 1098), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 1010), 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 259), octadecyl β-(4-hydroxy-3,5-di-tert-butylphenyl)propionate (Irganox 1076), or 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acrylic acid]-1,1-dimethyl}-2,4,8,10-tetraoxaspirocycloundecane (ADK AO-80).

[0037] The phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl) phosphite (Irganox 168), bis(2,6-di-tert-butyl-4-tolyl) pentaerythritol phosphite (PEP-36), or 627A.

[0038] In this invention, commonly used lubricants can be selected according to existing technology, such as, but not limited to, one or more of polysiloxane, calcium stearate, magnesium stearate, zinc stearate or PE wax.

[0039] In this invention, commonly used weathering agents can be selected according to existing technology, such as, but not limited to, hindered amine light stabilizers, benzotriazole light stabilizers, or benzophenone light stabilizers.

[0040] This invention also protects a method for preparing the above-mentioned self-lubricating, high-toughness, flame-retardant SAS composition, comprising the following steps:

[0041] The above components are mixed evenly in proportion, and then melt-blended and extruded into granules by an extruder to obtain a self-lubricating, high-toughness, flame-retardant SAS composition.

[0042] Furthermore, the extruder is a twin-screw extruder.

[0043] Furthermore, the temperature of the twin-screw extruder in zones one to two is 240℃~250℃; the temperature of zones three to five is 250℃~265℃; and the temperature of zones six to ten is 265℃~280℃.

[0044] The application of the above-mentioned self-lubricating, high-toughness, flame-retardant SAS composition in the manufacture of kitchen appliances is also within the scope of protection of this invention.

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

[0046] This invention provides a self-lubricating, high-toughness, flame-retardant SAS composition. By using SAS resin as the base resin and selecting 220 to 430 times expanded graphite as a flame retardant or compounding it with phosphate esters as a flame retardant, a SAS composition with good flame-retardant properties can be prepared with a small amount of flame retardant. At the same time, it also has good toughness and self-lubricating properties, making it particularly suitable for applications in kitchen appliances and the like. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to specific embodiments. These embodiments are only used to explain the present invention and are not intended to limit the scope of the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used are commercially available unless otherwise specified.

[0048] Raw materials used in each embodiment and comparative example:

[0049] Styrene-acrylonitrile-silicone copolymer (SAS resin)

[0050] SAS resin 1: S351, melt flow rate of 21 cm⁻¹ at 220°C and 10 kg load. 3 / 10min, acrylonitrile content 20%, purchased from UMG Corporation, Japan;

[0051] SAS resin 2: TW15G, melt flow rate is 3 cm at 220℃ and 10 kg load. 3 / 10min, acrylonitrile content 30%, purchased from UMG Corporation, Japan;

[0052] ABS resin: ABS KF-730, with a melt flow rate of 20g / 10min at 220℃ and 10kg load, and an acrylonitrile content of 20%, purchased from Liaoning Kingfa Science & Technology Co., Ltd.

[0053] Toughening agent: ASA type high-rubber powder, Q-350, purchased from Anqiu Donghai Plastics Co., Ltd.;

[0054] Compatibilizer: Styrene-N-phenylmaleimide, HW-330, purchased from Jiaxing Huawen Chemical Co., Ltd.;

[0055] Flame retardant:

[0056] Natural graphite was placed in concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1. After stirring, washing and drying, the expansion ratio was controlled by controlling the processing temperature and time to obtain expanded graphite with different expansion ratios.

[0057] Flame retardant A-1: ​​Expanded graphite, self-made, treated at 950℃ for 15s, the expansion ratio was measured to be 300±20 times;

[0058] Flame retardant A-2: Expanded graphite, self-made, treated at 900℃ for 15s, the expansion ratio was measured to be 250±20 times;

[0059] Flame retardant A-3: Expanded graphite, self-made, treated at 1000℃ for 15s, the expansion ratio was measured to be 350±20 times;

[0060] Flame retardant A-4: Expanded graphite, self-made, treated at 850℃ for 15s, the expansion ratio was measured to be 150±20 times;

[0061] Flame retardant A-5: Expanded graphite, self-made, treated at 1150℃ for 20s, the expansion ratio was measured to be 500±20 times;

[0062] Flame retardant A-6: Expanded graphite, EG-E300, with an expansion ratio of 300±20 times, purchased from Qingdao Yanhai Carbon Materials Co., Ltd.

[0063] It should be noted that the method for determining the expansion ratio of the expanded graphite mentioned above is as follows:

[0064] The volume change of expanded graphite before and after expansion is measured. The ratio of the volume after expansion to the volume before expansion is the expansion ratio. The volume after expansion is determined by placing the sample in a box-type resistance furnace at 950-1000℃, leaving the furnace door open, and observing until expansion stops. The sample is then immediately removed, poured into a graduated cylinder, and the volume after expansion is read. The average value is calculated after three measurements.

[0065] Flame retardant B1: Resorcinol bis(diphenyl phosphate), FP-600, purchased from Idico Japan;

[0066] Flame retardant B2: Bisphenol A bis(diphenyl phosphate), WSFR-BDP-N2, purchased from Zhejiang Wansheng Company.

[0067] Flame retardant C: Bromotriazine flame retardant, FR-245, purchased from Dead Sea Bromine Company, Israel;

[0068] Inorganic filler: Talc powder, 3000 mesh, commercially available;

[0069] Additives: The antioxidants were a mixture of hindered phenolic antioxidant RIANOX 1010 and phosphite antioxidant RIANOX 168 in a mass ratio of 1:1; both were commercially available; the same additives were used in the parallel experiments of the examples and comparative examples.

[0070] The SAS compositions described in the examples and comparative examples were prepared according to the formulations in Tables 1-2 by the following method, including the following steps:

[0071] The components are mixed evenly according to the proportions, and then melt-blended and extruded by a twin-screw extruder to obtain a self-lubricating, high-toughness, flame-retardant SAS composition.

[0072] Specifically, the temperature of the twin-screw extruder in zones one to two is 215°C; the temperature in zones three to five is 225°C; and the temperature in zones six to ten is 230°C.

[0073] The components in each embodiment and comparative example are shown in Tables 1-2.

[0074] Examples 1-15 and Comparative Examples 1-6

[0075] Table 1. Amounts of each component in the self-lubricating, high-toughness, flame-retardant SAS compositions in Examples 1-8 (unit: parts by weight)

[0076]

[0077] Table 2. Amounts of each component in the SAS compositions of Examples 9-15 and Comparative Examples 1-6 (unit: parts by weight)

[0078]

[0079] Performance testing:

[0080] The performance of the SAS compositions prepared in the above examples and comparative examples was tested. The specific test items and test methods are as follows:

[0081] 1. Testing Method

[0082] (1) Flame retardant performance test: The SAS compositions prepared in the examples and comparative examples were tested according to UL-94 standard with thicknesses of 3.2 mm and 2.5 mm, respectively.

[0083] (2) Self-lubricating performance test: The SAS compositions prepared in the examples and comparative examples were tested according to ISO 8295-2004.

[0084] (3) Impact performance test: The SAS compositions prepared in the examples and comparative examples were tested according to ISO 180-2019 standard, A-type notch, 23°C, 50% humidity.

[0085] 2. Test Results

[0086] The test results for each embodiment and comparative example are shown in Table 3.

[0087] Table 3. Measurement results of each embodiment and comparative example.

[0088]

[0089]

[0090] As can be seen from Table 3, the self-lubricating, high-toughness flame-retardant SAS compositions prepared in the various embodiments of the present invention have good flame-retardant properties, as well as good toughness and self-lubricating properties. Specifically, the SAS compositions can all achieve a V-0 flame retardancy of 3.2 mm, a dynamic friction coefficient of no more than 0.3, and an impact strength of no less than 15 kJ / m. 2 .

[0091] As can be seen from Examples 1 to 3, when the expansion ratio of expanded graphite is 275 to 370 times, the overall performance of the prepared SAS composition is better, achieving a V-0 flame retardancy of 2.5 mm and higher toughness.

[0092] As can be seen from Examples 1 and 4-7, when the mass ratio of flame retardant A to flame retardant B is (1-2):1, a SAS composition with comparable or better overall performance can be obtained with less flame retardant.

[0093] As can be seen from Comparative Example 1, if ABS resin is used to replace SAS resin, the resulting composition has better flame retardant properties, but it cannot provide good self-lubricating properties and has poor solvent resistance during application.

[0094] As can be seen from Comparative Example 2, if expanded graphite is used alone as a flame retardant, increasing its dosage can make the SAS composition achieve a better flame retardant effect, but the toughness will decrease significantly, affecting its application.

[0095] As can be seen from Comparative Example 3, if a single phosphate ester compound is used as a flame retardant, the resulting SAS composition has poor flame retardant properties.

[0096] As can be seen from Comparative Example 4, if expanded graphite is compounded with other types of flame retardants, it cannot achieve a good flame retardant effect at the same addition amount.

[0097] Comparative Examples 5 and 6 show that if the expansion ratio of the expanded graphite used is too small or too large, it will not achieve a good flame retardant effect and will affect its self-lubricating properties.

[0098] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A self-lubricating high toughness flame retardant SAS composition characterized in that, It comprises the following components by weight: The total amount of the flame retardant A and the flame retardant B is 15% to 20% of the SAS composition. The flame retardant A is expanded graphite with an expansion ratio of 220 to 430; the flame retardant B is a phosphoric acid ester compound.

2. The self-lubricating, high-tenacity, flame-retardant SAS composition of claim 1, wherein, The mass ratio of the flame retardant A to the flame retardant B is (1 to 2) to 1.

3. The self-lubricating, high-tenacity, flame-retardant SAS composition of claim 1, wherein, The expansion ratio of the expanded graphite is 275 to 370.

4. The self-lubricating, high-tenacity, flame-retardant SAS composition of claim 1, wherein, The phosphoric acid ester compound is one or a mixture of several of resorcinol bis(diphenyl phosphate), polybisphenol A bis(diphenyl phosphate) and triphenyl phosphate.

5. The self-lubricating, high-tenacity, flame-retardant SAS composition of claim 1, wherein, The toughening agent is one or a mixture of several of ASA type high glue powder, butadiene type high glue powder and MBS.

6. The self-lubricating, high-toughness, flame-retardant SAS composition of claim 1, wherein, The compatibilizer is styrene-N-phenyl maleimide.

7. The self-lubricating, high toughness, flame retardant SAS composition of claim 1, wherein, The melt flow rate of the SAS resin is 2 to 25 cm3 / 10 min at 220°C under a load of 10 kg 3 / 10 min.

8. The self-lubricating, high-toughness, flame-retardant SAS composition of claim 1, wherein, The SAS composition further comprises 0.5 to 10 parts of inorganic filler and 0.1 to 3 parts of auxiliary agent.

9. A process for the preparation of the self-lubricating high toughness flame retardant SAS composition according to any one of claims 1 to 8, characterized in that, It comprises the following steps: The above components are mixed uniformly in proportion, then melt blended, extruded and granulated by an extruder to obtain the self-lubricating high-toughness flame-retardant SAS composition.

10. Use of the self-lubricating high-toughness flame-retardant SAS composition according to any one of claims 1 to 8 in the preparation of materials for kitchen appliances.

Images