Thermal aging and discoloration resistant polyphenylene sulfide material and preparation method thereof

Abstract

The invention provides a thermal aging discoloration resistant polyphenylene sulfide material and a preparation method thereof. The thermal aging discoloration resistant polyphenylene sulfide material is prepared from the following raw materials: an antioxidant and polyphenylene sulfide powder, the antioxidant is prepared from a combination of tetra [beta-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and bis (2, 6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite ester. The thermal aging and discoloration resistant polyphenylene sulfide material provided by the invention has good oxidation resistance, can resist thermal aging and discoloration, and can still maintain high whiteness after being exposed for a long time at a high temperature.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a heat-aging-resistant discoloration polyphenylene sulfide material and a preparation method thereof. Background Art

[0002] Polyphenylene sulfide (PPS) is a high-performance thermoplastic resin with excellent mechanical properties, electrical properties and heat resistance, and is widely used in electronic appliances, automobiles, machinery and other fields. However, during processing and use, polyphenylene sulfide is easily degraded and discolored due to the influence of factors such as heat, light and oxygen, which affects its appearance and performance. Therefore, the use of antioxidants is essential, which can effectively inhibit the oxidative degradation of polyphenylene sulfide and improve its stability.

[0003] CN104194337A discloses a polyphenylene sulfide composite material, which includes the following components by weight percentage: 40% to 80% polyphenylene sulfide, 20% to 50% glass fiber, 3% to 10% impact modifier and 1% to 3% antioxidant, wherein the antioxidant is a hindered phenol antioxidant. The technical solution prevents the oxidative degradation of polyphenylene sulfide by adding a hindered phenol antioxidant.

[0004] CN110643179A discloses a high-toughness wear-resistant polyphenylene sulfide composite material, which comprises, by weight, at least: 30-70 parts of polyphenylene sulfide, 0.2-0.5 parts of antioxidant, 1-3 parts of lubricant, 5-15 parts of toughening agent, 5-15 parts of wear-resistant additive and 20-40 parts of glass fiber, wherein the antioxidant is antioxidant 1010. The technical solution prevents the oxidative degradation of polyphenylene sulfide by adding antioxidant 1010.

[0005] In the existing technology, a single type of antioxidant is usually used to improve the stability of polyphenylene sulfide. Adding hindered phenol antioxidants can effectively prevent the oxidative degradation of polyphenylene sulfide, but adding hindered phenol antioxidants is not effective in improving the whiteness and yellowing of polyphenylene sulfide; adding thioester antioxidants can effectively improve the whiteness and yellowing of polyphenylene sulfide, but the antioxidant effect is not good, and yellowing is still prone to occur when exposed to high temperatures for a long time.

[0006] Therefore, it is necessary to develop a polyphenylene sulfide material with good antioxidant properties and resistance to thermal aging and discoloration. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention aims to provide a heat aging discoloration resistant polyphenylene sulfide material and a preparation method thereof. The heat aging discoloration resistant polyphenylene sulfide material has good antioxidant properties, can resist heat aging discoloration, and can maintain a high whiteness when exposed to a high temperature of 320°C for a long time.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a polyphenylene sulfide material that is resistant to heat aging and discoloration. The raw materials for preparing the polyphenylene sulfide material that is resistant to heat aging and discoloration include an antioxidant and polyphenylene sulfide powder; the antioxidant includes a combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester (antioxidant 1010) and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (antioxidant PEP-36).

[0010] In the present invention, the tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite are compounded as antioxidants to prepare a heat aging-resistant discoloration polyphenylene sulfide material having good antioxidant properties, being able to resist heat aging discoloration, and being able to maintain a high whiteness even when exposed to a high temperature for a long time.

[0011] Preferably, the mass ratio of the tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is (0.1-5):1, for example, 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1 or 4.5:1, and more preferably (0.1-0.3):1.

[0012] Preferably, the polyphenylene sulfide powder is a polymer with a linear structure.

[0013] Preferably, the melt index of the polyphenylene sulfide powder at 315° C. and 5 kg load is 200 to 900 g / 10 min, for example, 300 g / 10 min, 400 g / 10 min, 500 g / 10 min, 600 g / 10 min, 700 g / 10 min or 800 g / 10 min.

[0014] Preferably, the melting point of the polyphenylene sulfide powder is 255-280°C, for example, 258°C, 261°C, 264°C, 267°C, 270°C, 273°C, 276°C or 279°C.

[0015] Preferably, based on the total mass of the polyphenylene sulfide powder and the antioxidant as 100%, the mass of the antioxidant is 0.05% to 3%, for example, 0.1%, 0.3%, 0.5%, 0.7%, 0.9%, 1.1%, 1.3%, 1.5%, 1.7%, 1.9%, 2.1%, 2.3%, 2.5%, 2.7% or 2.9%, etc., and more preferably 0.3% to 0.12%.

[0016] In a second aspect, the present invention provides a method for preparing the heat aging resistant discoloration polyphenylene sulfide material as described in the first aspect, the preparation method comprising the following steps:

[0017] (1) mixing an antioxidant and a solvent to obtain a mixed solution;

[0018] (2) The mixed solution obtained in step (1) and the polyphenylene sulfide powder are mixed, dried, and granulated to obtain the heat-resistant aging discoloration polyphenylene sulfide material.

[0019] In the present invention, by preparing a mixed liquid of an antioxidant and a solvent and then mixing it with polyphenylene sulfide powder, the dispersion uniformity of a low-content antioxidant in a polyphenylene sulfide matrix is ​​improved, and the utilization rate of the antioxidant is increased. In addition, the preparation method is suitable for mass production and is safe, the solvent is easily volatile, and almost no impurities that affect the performance are introduced.

[0020] Preferably, the solvent comprises tetrahydrofuran.

[0021] Preferably, the mass ratio of the antioxidant to the solvent is (0.5-5):100, for example, 1:100, 1.5:100, 2:100, 2.5:100, 3:100, 3.5:100, 4:100 or 4.5:100, etc.

[0022] Preferably, the mixing in step (2) specifically comprises adding the polyphenylene sulfide powder into a high-speed mixer for a first stirring, and simultaneously atomizing the mixed solution obtained in step (1) and adding it to the polyphenylene sulfide powder, and then performing a second stirring.

[0023] Preferably, the first stirring speed is 200-500 rpm, for example, 230 rpm, 260 rpm, 290 rpm, 320 rpm, 350 rpm, 380 rpm, 410 rpm, 440 rpm or 470 rpm.

[0024] Preferably, the first stirring time is 10 to 120 s, such as 30 s, 50 s, 70 s, 90 s, 110 s or 110 s.

[0025] Preferably, the rotation speed of the second stirring is 800-1000 rpm, for example, 820 rpm, 840 rpm, 860 rpm, 880 rpm, 900 rpm, 920 rpm, 940 rpm, 960 rpm or 980 rpm.

[0026] Preferably, the second stirring time is 30 to 600 s, for example, 50 s, 100 s, 150 s, 200 s, 250 s, 300 s, 350 s, 400 s, 450 s, 500 s or 550 s.

[0027] Preferably, the drying temperature in step (2) is 110-130°C, for example, 112°C, 114°C, 116°C, 118°C, 120°C, 122°C, 124°C, 126°C or 128°C.

[0028] Preferably, the drying time in step (2) is 6 to 8 hours, for example, 6.2 hours, 6.4 hours, 6.6 hours, 6.8 hours, 7.0 hours, 7.2 hours, 7.4 hours, 7.6 hours or 7.8 hours.

[0029] Preferably, the granulation in step (2) is carried out in a twin-screw extruder.

[0030] Preferably, the granulation temperature is 260-280°C, for example, 262°C, 264°C, 266°C, 268°C, 270°C, 272°C, 274°C, 276°C or 278°C.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The invention prepares a polyphenylene sulfide material resistant to heat aging discoloration by compounding tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite as antioxidants. The material has good antioxidant performance, can resist heat aging discoloration, can maintain high whiteness when exposed to a high temperature of 320°C for a long time, and the polyphenylene sulfide color plate obtained by injection molding after short-time residence (4 minutes of residence) has an L value of ≥90, and the polyphenylene sulfide color plate obtained by injection molding after extreme residence (12 minutes of residence) can still have an L value of ≥69. Preferably, the polyphenylene sulfide color plate obtained by injection molding after short-time residence (4 minutes of residence) has an L value of ≥95, and the polyphenylene sulfide color plate obtained by injection molding after extreme residence (12 minutes of residence) can still have an L value of ≥74, and the material can be used to develop polyphenylene sulfide products with bright colors and high whiteness. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0034] Some of the components in the following examples and comparative examples are as follows:

[0035] Polyphenylene sulfide powder A: The melt index is 300 g / 10 min at 315° C. and 5 kg load, and the melting point is 271° C. It is a polymer with a linear structure.

[0036] Polyphenylene sulfide powder B: The melt index is 450 g / 10 min at 315° C. and 5 kg load, and the melting point is 265° C. It is a polymer with a linear structure.

[0037] Example 1

[0038] This embodiment provides a heat-resistant aging discoloration polyphenylene sulfide material and a preparation method thereof. The preparation method of the heat-resistant aging discoloration polyphenylene sulfide material comprises the following steps:

[0039] (1) pouring an antioxidant into a container containing a solvent, wherein the mass ratio of the antioxidant to the solvent is 1:100, and dispersing the antioxidant using a multifunctional agitator to obtain a mixed solution;

[0040] (2) placing the polyphenylene sulfide powder into a high-speed mixer for a first stirring, and during the stirring process, atomizing the mixed solution prepared in step (1) and adding it to the polyphenylene sulfide powder, the speed of the first stirring being 300 rpm, the time being 10 s, so that the mixed solution is fully coated on the surface of the polyphenylene sulfide powder, and after the mixed solution is completely added, increasing the speed for a second stirring, the speed of the second stirring being 900 rpm, the time being 120 s, and then placing in a vacuum dryer for drying, the drying temperature being 120° C., the time being 7 h, and finally using a twin-screw extruder for granulation, the temperature of the twin-screw extruder being 270° C., the screw speed being 350 rpm, to obtain the heat aging resistant discoloration polyphenylene sulfide material;

[0041] The antioxidant is a combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite in a mass ratio of 0.5:1;

[0042] The above solvent is tetrahydrofuran;

[0043] The polyphenylene sulfide powder is polyphenylene sulfide powder A;

[0044] Based on the total mass of the antioxidant and the polyphenylene sulfide powder being 100%, the mass percentage of the antioxidant is 0.3%.

[0045] Example 2

[0046] This embodiment provides a polyphenylene sulfide material that is resistant to heat aging and discoloration and a preparation method thereof. The difference between this embodiment and embodiment 1 is that the mass ratio of the combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is adjusted to 1:1, and other conditions are the same as those in embodiment 1.

[0047] Example 3

[0048] This embodiment provides a polyphenylene sulfide material that is resistant to heat aging and discoloration and a preparation method thereof. The difference between this embodiment and embodiment 1 is that the mass ratio of the combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is adjusted to 2:1, and other conditions are the same as those in embodiment 1.

[0049] Example 4

[0050] This embodiment provides a polyphenylene sulfide material that is resistant to heat aging and discoloration and a preparation method thereof. The difference between this embodiment and embodiment 1 is that the mass ratio of the combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is adjusted to 5:1, and other conditions are the same as those in embodiment 1.

[0051] Example 5

[0052] This embodiment provides a polyphenylene sulfide material that is resistant to heat aging and discoloration and a preparation method thereof. The difference between this embodiment and Example 1 is that the mass ratio of the combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is adjusted to 0.1:1, and other conditions are the same as those in Example 1.

[0053] Example 6

[0054] This embodiment provides a polyphenylene sulfide material that is resistant to heat aging and discoloration and a preparation method thereof. The difference between this embodiment and Example 1 is that the mass ratio of the combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is adjusted to 0.2:1, and other conditions are the same as those in Example 1.

[0055] Example 7

[0056] This embodiment provides a polyphenylene sulfide material that is resistant to heat aging and discoloration and a preparation method thereof. The difference between this embodiment and Example 1 is that the mass ratio of the combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is adjusted to 0.3:1, and other conditions are the same as those in Example 1.

[0057] Example 8

[0058] This embodiment provides a polyphenylene sulfide material resistant to heat aging and discoloration and a preparation method thereof. The difference between this embodiment and embodiment 1 is that the mass percentage of the antioxidant is 0.06%, based on the total mass of the antioxidant and the polyphenylene sulfide powder being 100%, and other conditions are the same as those in embodiment 1.

[0059] Example 9

[0060] This embodiment provides a polyphenylene sulfide material resistant to heat aging and discoloration and a preparation method thereof. The difference between this embodiment and embodiment 1 is that the mass percentage of the antioxidant is 0.12%, based on the total mass of the antioxidant and the polyphenylene sulfide powder being 100%, and other conditions are the same as those in embodiment 1.

[0061] Example 10

[0062] This embodiment provides a heat-resistant aging discoloration polyphenylene sulfide material and a preparation method thereof. The preparation method of the heat-resistant aging discoloration polyphenylene sulfide material comprises the following steps:

[0063] (1) pouring an antioxidant into a container containing a solvent, wherein the mass ratio of the antioxidant to the solvent is 0.5:100, and dispersing the antioxidant using a multifunctional agitator to obtain a mixed solution;

[0064] (2) placing the polyphenylene sulfide powder into a high-speed mixer for a first stirring, and during the stirring process, atomizing the mixed solution prepared in step (1) and adding it to the polyphenylene sulfide powder, the speed of the first stirring being 250 rpm, the time being 15 s, so that the mixed solution is fully coated on the surface of the polyphenylene sulfide powder, and after the mixed solution is completely added, increasing the speed for a second stirring, the speed of the second stirring being 800 rpm, the time being 120 s, and then placing in a vacuum dryer for drying, the drying temperature being 120° C., the time being 8 h, and finally using a twin-screw extruder for granulation, the temperature of the twin-screw extruder being 270° C., the screw speed being 350 rpm, to obtain the heat aging resistant discoloration polyphenylene sulfide material;

[0065] The antioxidant is a combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite in a mass ratio of 0.2:1;

[0066] The above solvent is tetrahydrofuran;

[0067] The polyphenylene sulfide powder is polyphenylene sulfide powder B;

[0068] Based on the total mass of the antioxidant and the polyphenylene sulfide powder being 100%, the mass percentage of the antioxidant is 1.2%.

[0069] Comparative Example 1

[0070] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that no antioxidant is added, and other conditions are the same as those of Example 1.

[0071] Comparative Example 2

[0072] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester is not added, the antioxidant is bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, and the mass percentage of the antioxidant is maintained at 0.3%, based on the total mass of the antioxidant and the polyphenylene sulfide powder as 100%, and the other conditions are the same as those in Example 1.

[0073] Comparative Example 3

[0074] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is not added, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and the mass percentage of the antioxidant is maintained at 0.3%, based on the total mass of the antioxidant and the polyphenylene sulfide powder as 100%. Other conditions are the same as those in Example 1.

[0075] Comparative Example 4

[0076] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is replaced with tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168) of the same mass, and other conditions are the same as those in Example 1.

[0077] Comparative Example 5

[0078] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is replaced with bis(2,4-dicumylphenyl)pentaerythritol diphosphite (antioxidant 9228) of the same mass, and other conditions are the same as those in Example 1.

[0079] Comparative Example 6

[0080] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is replaced with the same mass of 4,4'-[1,1'-biphenyl]diphosphonic acid-tetrakis[2,4-di-tert-butylphenyl]ester (antioxidant PEPQ), and other conditions are the same as those in Example 1.

[0081] Comparative Example 7

[0082] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] is replaced with triethylene glycol bis(3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate) (antioxidant 245) of the same mass, and other conditions are the same as those in Example 1.

[0083] Comparative Example 8

[0084] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that the antioxidant is a combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, triethylene glycol bis(3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate) and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite in a mass ratio of 0.25:0.25:1, and other conditions are the same as those in Example 1.

[0085] Comparative Example 9

[0086] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that the antioxidant is a combination of triethylene glycol bis(3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate) and tris(2,4-di-tert-butylphenyl) phosphite in a mass ratio of 0.5:1, and other conditions are the same as those in Example 1.

[0087] Comparative Example 10

[0088] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that the antioxidant is a combination of triethylene glycol bis(3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate) and bis(2,4-dicumylphenyl) pentaerythritol diphosphite in a mass ratio of 0.5:1, and other conditions are the same as those in Example 1.

[0089] Comparative Example 11

[0090] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that the antioxidant is tris(2,4-di-tert-butylphenyl) phosphite, and other conditions are the same as those in Example 1.

[0091] Comparative Example 12

[0092] This comparative example provides a polyphenylene sulfide material and a preparation method thereof. The difference between the comparative example and Example 1 is that the antioxidant is triethylene glycol bis(3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate), and other conditions are the same as those in Example 1.

[0093] Comparative Example 13

[0094] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which differs from Example 1 in that the antioxidant is bis(2,4-dicumylphenyl)pentaerythritol diphosphite, and other conditions are the same as those in Example 1.

[0095] Comparative Example 14

[0096] This comparative example provides a polyphenylene sulfide material and a preparation method thereof, which is different from Example 1 in that the antioxidant is 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, and other conditions are the same as those in Example 1.

[0097] Comparative Example 15

[0098] This comparative example provides a polyphenylene sulfide material and a preparation method thereof. The difference between the comparative example and Example 1 is that the antioxidant is 4,4'-[1,1'-biphenyl]diphosphonic acid-tetrakis[2,4-di-tert-butylphenyl] ester, and other conditions are the same as those in Example 1.

[0099] The heat-aging-resistant discoloration polyphenylene sulfide materials provided in the above-mentioned embodiments 1 to 10 and the polyphenylene sulfide materials provided in comparative examples 1 to 15 were respectively subjected to color plate injection molding at 320°C using a 110T Nissin injection molding machine. The color difference values ​​(L values) of the polyphenylene sulfide color plates obtained with injection molding residence times of 4 min, 8 min and 12 min were tested. The color difference values ​​were measured using a colorimeter. The test results are shown in Table 1 below.

[0100] Table 1

[0101]

[0102]

[0103] It can be seen from the contents of Table 1 that the heat aging resistant color-changing polyphenylene sulfide materials obtained in Examples 1 to 10 have an L value of ≥90 for the polyphenylene sulfide color plate obtained by injection molding after a short residence time (4 min residence), and an L value of ≥69 for the polyphenylene sulfide color plate obtained by injection molding after an extreme residence time (12 min residence), have a high whiteness, can effectively inhibit the degradation of polyphenylene sulfide, inhibit the generation of color bases, and have good long-term aging resistance.

[0104] Compared with Examples 1 to 7, it can be seen that when the mass ratio of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is (0.1 to 0.3):1, the prepared heat aging-resistant color-discoloration polyphenylene sulfide material has better aging-resistant color-discoloration performance.

[0105] Compared with Example 1, if no antioxidant is included (Comparative Example 1), the L value of the polyphenylene sulfide color plate obtained by injection molding is lower.

[0106] Compared with Example 1, if the antioxidant is bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite (Comparative Example 2), the L value after the extreme residence (retention 12 min) is 70, which is relatively low; if the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Comparative Example 3), the L value of the polyphenylene sulfide color plate obtained by injection molding after a short residence time (retention 4 min) is as high as 93, but the L value of the polyphenylene sulfide color plate obtained by injection molding after the extreme residence (retention 12 min) is lower. It can be seen that the performance of the polyphenylene sulfide material resistant to heat aging and discoloration prepared by compounding tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite as an antioxidant is better.

[0107] Compared with Example 1, Comparative Examples 4 to 15 use other two antioxidant combinations or one antioxidant to prepare polyphenylene sulfide materials, and the L values ​​of the polyphenylene sulfide color plates obtained by extreme retention (retention 12 minutes) injection molding are all low. It can be seen that the thermal aging-resistant discoloration polyphenylene sulfide material prepared by compounding tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite as antioxidants has better performance.

[0108] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate a heat-resistant aging discoloration polyphenylene sulfide material and its preparation method, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A polyphenylene sulfide material resistant to heat aging and discoloration, characterized in that: The raw materials for preparing the heat aging resistant discoloration polyphenylene sulfide material include an antioxidant and polyphenylene sulfide powder; the antioxidant includes a combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite.

2. The heat-aging-resistant discoloration polyphenylene sulfide material according to claim 1, characterized in that: The mass ratio of the tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester to bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is (0.1-5):1, and more preferably (0.1-0.3):

1.

3. The heat-resistant aging discoloration polyphenylene sulfide material according to claim 1 or 2, characterized in that: The polyphenylene sulfide powder is a polymer with a linear structure; Preferably, the melt index of the polyphenylene sulfide powder at 315° C. and 5 kg load is 200 to 900 g / 10 min; Preferably, the melting point of the polyphenylene sulfide powder is 255-280°C.

4. The preparation method according to any one of claims 1 to 3, characterized in that: Based on the total mass of the polyphenylene sulfide powder and the antioxidant being 100%, the mass of the antioxidant is 0.05% to 3%.

5. A method for preparing the heat-resistant aging discoloration polyphenylene sulfide material according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: (1) mixing an antioxidant and a solvent to obtain a mixed solution; (2) The mixed solution obtained in step (1) and the polyphenylene sulfide powder are mixed, dried, and granulated to obtain the heat-resistant aging discoloration polyphenylene sulfide material.

6. The preparation method according to claim 5, characterized in that: The solvent includes tetrahydrofuran.

7. The preparation method according to claim 5 or 6, characterized in that: The mass ratio of the antioxidant to the solvent is (0.5-5):

100.

8. The preparation method according to any one of claims 5 to 7, characterized in that: The mixing in step (2) specifically comprises adding the polyphenylene sulfide powder into a high-speed mixer for a first stirring, and simultaneously atomizing the mixed solution obtained in step (1) and adding it to the polyphenylene sulfide powder, and then performing a second stirring; Preferably, the first stirring speed is 200-500 rpm; Preferably, the first stirring time is 10 to 120 seconds; Preferably, the second stirring speed is 800-1000 rpm; Preferably, the second stirring time is 30 to 600 seconds.

9. The preparation method according to any one of claims 5 to 8, characterized in that: The drying temperature in step (2) is 110-130° C. Preferably, the drying time in step (2) is 6 to 8 hours.

10. The preparation method according to any one of claims 5 to 9, characterized in that: The granulation in step (2) is carried out in a twin-screw extruder.

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