Nylon material as well as preparation method and application thereof

Abstract

The invention provides a nylon material as well as a preparation method and application thereof. The nylon material is prepared from the following raw materials in parts by weight: 30-65 parts of PPA resin; 8-15 parts of a flame retardant; 0.1 to 0.5 part of organic acid stannous; 0.5 to 2 parts of talcum powder; 0.1 to 0.5 part of an antioxidant; 0.2 to 0.4 part of a heat stabilizer; and 25 to 50 parts of glass fiber. The organic acid stannous and the talcum powder are introduced into the nylon material, and through the synergistic effect of the organic acid stannous and the talcum powder, the acidic condition for inducing thermal degradation of the PPA resin is eliminated, so that the nylon material has excellent aging resistance, flame retardance and mechanical properties, and meanwhile, the nylon material is not greyed.

Description

Technical Field

[0001] This invention belongs to the field of polyamide technology, and particularly relates to a nylon material, its preparation method and application. Background Technology

[0002] Polyamide (PA) is widely used in the automotive, electronics, and small appliance industries due to its excellent mechanical, electrical, chemical, and processing properties. With technological advancements and evolving market demands, the electronics industry is trending towards miniaturization, integration, and higher power output. While this trend leads to enhanced functionality and reduced size, it also results in a sharp increase in the power density of electrical components and localized overheating issues. Common household appliances that directly generate high temperatures, such as hair dryers, hot air combs, and hair straighteners, have their core components constantly exposed to high-temperature environments. This exposure can easily cause thermal-oxidative aging of materials, leading to a decline in mechanical properties and affecting product lifespan. Such continuous or intermittent high-temperature conditions pose a serious challenge to the long-term reliability of the materials used.

[0003] To meet the demands of high-temperature environments, high-temperature nylon offers significant advantages over ordinary nylon. High-temperature nylons, represented by phthalamide (PPA), typically have melting points exceeding 300°C and long-term operating temperatures exceeding 150°C. However, in safety-sensitive fields such as electronics and electrical appliances, materials must also meet stringent flame-retardant standards (UL94 1.5mm V-0 rating). Nylon's inherent self-extinguishing properties are insufficient to achieve this level. Therefore, flame retardants must be added to improve flame retardancy. Traditional halogenated flame retardants (such as bromine-based and chlorine-based halogenated nylons) offer high flame-retardant efficiency, but they produce large amounts of dense smoke, corrosive gases, and toxic gases during combustion, posing environmental and personal safety hazards and limiting their application. Halogen-free flame-retardant systems, especially phosphorus-based and phosphorus-nitrogen-based flame retardants, have become the mainstream development direction for nylon flame retardancy due to their advantages of low smoke, low toxicity, and environmental friendliness.

[0004] Therefore, PPA materials, which combine high efficiency halogen-free flame retardancy with excellent long-term heat aging resistance, have become a key material for high-end electronic and electrical applications. However, this material still faces the following challenges in application: (1) The processing temperature of PPA is as high as 350°C. At this temperature, high efficiency halogen-free flame retardants such as aluminum diethyl phosphite (ADP) are easily decomposed to produce phosphoric acid, which will aggravate the thermal degradation and oxidation reaction of the molecular chain of PPA resin during melt processing; (2) The residual acidic catalysts that are difficult to completely remove during the synthesis of PPA resin will have a superimposed effect with the acidic environment generated by the decomposition of flame retardants, further aggravating the polymer chain breakage during processing; (3) The copper salt heat stabilizers added to improve heat aging resistance are inhibited in the high-temperature acidic environment formed by the decomposition of flame retardants (such as ADP). The complexation of copper ions with nylon amide groups not only fails to effectively stabilize the molecular chain under acidic conditions, but also intensifies the formation of alkyl free radicals by methylene groups bonded to nitrogen atoms. This leads to a rapid decrease in the molecular weight of the material, resulting in grayish plastic particles and a large number of aging "active sites" pre-embedded inside. After injection molding, the thermo-oxidative aging reaction is more intense, and the aging resistance cannot be effectively improved.

[0005] CN112574559B discloses a high heat-resistant halogen-free flame-retardant polyamide composite, prepared from the following raw materials in parts by weight: aliphatic polyamide: 10-60 parts; aromatic polyamide: 5-30 parts; halogen-free flame retardant: 10-30 parts; phenolic resin: 1-10 parts; glass fiber: 10-50 parts; antioxidant: 0.1-0.5 parts. Through the synergistic effect of multiple components—phenolic resin, antioxidant, aromatic nylon, and halogen-free flame retardant—the halogen-free flame-retardant polyamide composite possesses excellent aging resistance, flame retardancy, and mechanical properties. However, the main components of the polyamide composite are PA66, PA66 / 6I, and PA66 / 6T, which have much lower processing temperatures than PPA. Their thermal degradation reaction is also less severe than that of PPA, and the tensile strength decays slowly in thermal aging tests. Therefore, the tensile strength decay alone cannot fully reflect the material's heat aging resistance.

[0006] CN107903624B discloses a high-temperature aging-resistant halogen-free flame-retardant polyamide material, prepared from the following raw materials in parts by weight: PA6 resin 91%, nitrogen-based halogen-free flame retardant MC-25 8%, copper salt heat stabilizer H3336 0.3%, antioxidant 1098 0.15%, antioxidant PEPQ 0.2%, antioxidant 445 0.2%, and dispersant EBS 0.2%. By adjusting the flame retardant feeding method to side-feed the flame retardant, the thermal degradation of the flame retardant during processing can be reduced. However, the processing temperature is low, not exceeding 250℃. This method is only applicable to nylon materials with low processing temperatures. For high-temperature nylon, simply changing the flame retardant feeding method cannot significantly reduce flame retardant decomposition, let alone inhibit material thermal degradation.

[0007] Therefore, developing a nylon material with excellent aging resistance, flame retardancy, high whiteness, and high temperature resistance is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0008] In view of the shortcomings of the prior art, the purpose of this invention is to provide a nylon material, its preparation method and application. This invention introduces organic stannous acid and talc into the nylon material. Through the synergistic effect of the two, the nylon material has excellent aging resistance, flame retardancy and mechanical properties. At the same time, the nylon material does not turn gray.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a nylon material, wherein the raw materials for preparing the nylon material comprise the following components by weight:

[0011] 30-65 parts of PPA resin;

[0012] 8-15 parts flame retardant;

[0013] 0.1-0.5 parts of organic acid stannous;

[0014] Talc powder 0.5-2 parts;

[0015] Antioxidant 0.1-0.5 parts;

[0016] Heat stabilizer 0.2-0.4 parts;

[0017] 25-50 parts glass fiber.

[0018] This invention uses high-temperature resistant nylon resin (PPA resin), with a melting point generally above 300℃, short-term temperature resistance of 270-290℃, and long-term service temperature reaching above 150℃. PPA resin itself is yellow or white. After adding a copper salt heat stabilizer, it forms a complex structure with the -NH- group in the PPA resin. While this makes the material more stable overall, it also causes the methylene groups attached to the -NH- to become more reactive, easily generating free radicals under high-temperature acidic conditions, triggering a violent thermal degradation reaction, resulting in grayish-black particles. Therefore, this invention introduces the organic acid stannous, Sn. 2+As an effective stabilizing center, on the one hand, it can form stable complexes with residual catalysts in PPA resin, eliminating a large number of pre-embedded aging "active sites" in nylon materials, significantly reducing the thermal degradation reaction of PPA resin during processing, improving the stability and aging resistance of nylon materials, and preventing the extruded particles from turning gray. On the other hand, stannous organic acid has a lubricating effect, not only improving melt flowability and reducing viscosity, but also reducing friction between the material and processing equipment without the need for additional flow agents or lubricants, thereby reducing heat generation and inhibiting the production of acidic substances due to flame retardant degradation caused by local overheating. This eliminates the key conditions that trigger the thermal degradation of PPA resin, further improving the aging resistance of nylon materials. In addition, stannous organic acid has good temperature resistance and can maintain structural stability at high processing temperatures of PPA resin. Talc powder is alkaline and can neutralize residual acidic catalysts in PPA and acidic substances produced during decomposition, effectively inhibiting the thermal degradation behavior of PPA resin and preventing the extruded particles from turning gray.

[0019] This invention, through the compounding of various components, especially the synergistic effect of organic acid stannous acid and talc, fundamentally eliminates the acidic environment that promotes the thermal degradation of PPA resin, effectively inhibits the degree of thermal degradation of PPA resin during processing, and makes the nylon material have excellent aging resistance, flame retardancy and mechanical properties. At the same time, the nylon material does not turn gray.

[0020] The amount of PPA resin used can be 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, or 65 parts, etc.

[0021] The amount of the flame retardant can be 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, or 15 parts, etc.

[0022] The amount of the organic acid stannous can be 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, or 0.5 parts, etc.

[0023] The amount of talc powder used can be 0.5 parts, 0.8 parts, 1 part, 1.5 parts, 1.8 parts, or 2 parts, etc.

[0024] The amount of the antioxidant can be 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, or 0.5 parts, etc.

[0025] The amount of heat stabilizer can be 0.2 parts, 0.3 parts, or 0.4 parts, etc.

[0026] The amount of glass fiber used can be 25 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, or 50 parts, etc.

[0027] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0028] Preferably, the organic stannous acid has a carbon number of C12-C20, such as C12, C13, C14, C15, C16, C17, C18, C19 or C20. Alkyl molecules in this carbon number range have large molecular weights and can be firmly bonded through physical entanglement or polarity, resulting in better compatibility and significantly inhibiting their migration or precipitation, thus ensuring that the nylon material has long-lasting stability and aging resistance.

[0029] Preferably, the organic stannous acid comprises stannous stearate and / or stannous laurate.

[0030] Preferably, the talc powder has a mesh size of 10,000-12,000, such as 10,000, 10,500, 11,000, 11,500 or 12,000.

[0031] In this invention, the talc powder with the best compatibility with PPA resin is within this mesh size range. If the particle size of the talc powder is too large, its compatibility with PPA resin will deteriorate, resulting in poor dispersibility during processing and increased friction with PPA resin, glass fiber, and equipment, which will adversely affect the performance of nylon materials. If the particle size of the talc powder is too small, although it will increase the compatibility with the system, the talc powder is prone to flying during the production process, making feeding difficult and easily adhering to the inner wall of the hopper.

[0032] Preferably, the PPA resin includes any one or a combination of at least two of PA5T / 6T resin, PA6T / 66 resin, PA9T resin, or PA10T resin.

[0033] Preferably, the flame retardant comprises a halogen-free flame retardant.

[0034] Preferably, the flame retardant comprises aluminum diethylphosphite.

[0035] In this invention, aluminum diethyl hypophosphite (ADP) exhibits excellent thermal stability, maintaining structural stability at PPA resin processing temperatures (>300℃) without thermal decomposition. Simultaneously, it demonstrates good compatibility with PPA resin, achieving uniform dispersion within the matrix. This ensures stable processing while preventing significant degradation in the overall performance of the nylon material.

[0036] Common halogen-free flame retardants used in nylon materials include ADP-compounded aluminum phosphite or ammonium polyphosphate. However, aluminum phosphite has poor compatibility with resin, resulting in whitening of the injection-molded product surface, while ammonium polyphosphate is prone to decomposition at the processing temperature of PPA resin.

[0037] Preferably, the antioxidant comprises any one or a combination of at least two of the following: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine (antioxidant 1098), octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168), bis(2,4-dicumylphenyl) pentaerythritol diphosphite (antioxidant 9228), or bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite (antioxidant 626).

[0038] Preferably, the antioxidant includes antioxidant 9228 and / or antioxidant 626.

[0039] Preferably, the heat stabilizer comprises a copper salt heat stabilizer.

[0040] Preferably, the heat stabilizer comprises a combination of cuprous iodide and potassium iodide.

[0041] In a second aspect, the present invention provides a method for preparing a nylon material as described in the first aspect, the method comprising the following steps:

[0042] (1) PPA resin is mixed with organic stannous acid, talc, antioxidant and heat stabilizer to obtain component A;

[0043] (2) The A component, flame retardant and glass fiber are melt-blended and extruded into granules to obtain the nylon material.

[0044] Preferably, the baking temperature is 115-125℃, such as 115℃, 117℃, 119℃, 121℃, 123℃ or 125℃.

[0045] Preferably, the baking time is 4-6 hours, such as 4 hours, 4.5 hours, 5 hours, 5.5 hours or 6 hours.

[0046] Preferably, the mixing speed is 80-120 rpm, such as 80 rpm, 90 rpm, 100 rpm, 110 rpm or 120 rpm.

[0047] Preferably, the mixing time is 4-6 minutes, such as 4 minutes, 5 minutes, or 6 minutes.

[0048] Preferably, the melt blending is carried out in a twin-screw extruder.

[0049] Preferably, component A is added from the main feed port, the flame retardant is added from the upstream feed port, and the glass fiber is added from the downstream feed port.

[0050] Preferably, the twin-screw extruder rotates at a speed of 300-350 rpm, such as 300 rpm, 310 rpm, 320 rpm, 330 rpm, 340 rpm, or 350 rpm.

[0051] Preferably, the processing temperatures of each zone of the twin-screw extruder are as follows: Zone 1: 300-320℃; Zone 2: 330-350℃; Zone 3: 330-350℃; Zone 4: 330-350℃; Zone 5: 300-320℃; Zone 6: 200-220℃; Zone 7: 200-220℃; Zone 8: 210-230℃; Zone 9: 190-210℃; and the die head temperature is 280-300℃.

[0052] Among them, 300-320℃ can be 300℃, 303℃, 306℃, 310℃, 313℃, 316℃ or 320℃, etc.

[0053] 330-350℃ can be 330℃, 333℃, 336℃, 340℃, 343℃, 346℃ or 350℃, etc.

[0054] 200-220℃ can be 200℃, 203℃, 206℃, 210℃, 213℃, 216℃ or 220℃, etc.

[0055] 210-230℃ can be 210℃, 213℃, 216℃, 220℃, 223℃, 226℃ or 230℃, etc.

[0056] 190-210℃ can be 190℃, 193℃, 196℃, 200℃, 203℃, 206℃ or 210℃, etc.

[0057] 280-300℃ can be 280℃, 283℃, 286℃, 290℃, 293℃, 296℃ or 300℃, etc.

[0058] Preferably, component A and the flame retardant are added before zone one, and the glass fiber is added in zone five.

[0059] Thirdly, the present invention provides an application of the nylon material as described in the first aspect in automobiles, electronic appliances, or home appliances.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] This invention, through the compounding of its components, especially the synergistic effect of the organic acid stannous acid and talc, fundamentally eliminates the acidic environment that promotes the thermal degradation of PPA resin, effectively inhibiting the thermal degradation of PPA resin. This results in nylon materials with excellent mechanical properties, flame retardancy, and aging resistance, while also preventing the nylon material from turning gray. Specifically, the nylon material prepared by this invention has a tensile strength >160MPa, tensile modulus >12000MPa, elongation >2.1%, flexural strength >230MPa, flexural modulus >9000MPa, and cantilever beam notched impact strength >10KJ / m. 2 Unnotched impact strength of cantilever > 50 KJ / m 2 After aging at 200℃ for 1000 hours, the tensile strength, flexural strength, and notched impact strength retention rate of the nylon material are all greater than 70%, while the unnotched impact strength retention rate is greater than 40%. Detailed Implementation

[0062] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0063] The source information of some raw materials in this embodiment of the invention is as follows:

[0064] PA5T / 6T resin: Chengdu Shenghong SH560;

[0065] PA6T / 66 resin: Chengdu Shenghong SH401;

[0066] PA66 resin: Huafeng EP158;

[0067] Diethylaluminum hypophosphite: Clariant OP-1230;

[0068] Stannous stearate: Ningbo Kemete HR506;

[0069] Stannous octoate: Hubei Chengfeng Chemical Co., Ltd.

[0070] Heat stabilizer: Brügmann H320;

[0071] Glass fiber: Chongqing Composite Materials 301HP;

[0072] Talc A: Yirui Stone 3CA, D50 particle size 1.3μm;

[0073] Talc B: Yirui Stone T10D, D50 particle size 2.0μm;

[0074] Antioxidant 9228: Shanghai Haipu Chemical Co., Ltd.

[0075] Antioxidant 626: Shanghai Haipu Chemical Co., Ltd.

[0076] Example 1

[0077] This embodiment provides a nylon material and its preparation method. The raw materials for preparing the nylon material include the following components by weight:

[0078] PA5T / 6T resin: 58 parts;

[0079] Diethylaluminum hypophosphite: 10 parts;

[0080] Stannous stearate: 0.3 parts;

[0081] Talc powder A: 1 part;

[0082] Antioxidant 9228: 0.4 parts;

[0083] Heat stabilizer: 0.3 parts;

[0084] Fiberglass: 30 parts;

[0085] The method for preparing the nylon material includes the following steps:

[0086] (1) PA5T / 6T resin baked at 120℃ for 5h, stannous stearate, talc A, antioxidant 9228 and heat stabilizer are stirred in a mixing tank at 100rpm for 5min to obtain component A;

[0087] (2) Component A is added from the main feed port, flame retardant is added from the upstream feed port, and glass fiber is added from the downstream feed port. The processing temperatures of each zone of the twin-screw extruder are 310°C for zone 1, 340°C for zone 2, 340°C for zone 3, 343°C for zone 4, 310°C for zone 5, 210°C for zone 6, 208°C for zone 7, 220°C for zone 8, 200°C for zone 9, and 290°C for the die head. The speed of the twin-screw extruder is 320 rpm. The mixture is melt-blended, extruded and granulated to obtain the nylon material.

[0088] Example 2

[0089] This embodiment provides a nylon material and its preparation method. The raw materials for preparing the nylon material include the following components by weight:

[0090] PA5T / 6T resin: 63 parts;

[0091] Diethylaluminum hypophosphite: 10 parts;

[0092] Stannous stearate: 0.3 parts;

[0093] Talc powder A: 1 part;

[0094] Antioxidant 626: 0.4 parts;

[0095] Heat stabilizer: 0.3 parts;

[0096] Fiberglass: 25 parts;

[0097] The method for preparing the nylon material includes the following steps:

[0098] (1) PA5T / 6T resin baked at 115℃ for 6h, stannous stearate, talc A, antioxidant 626 and heat stabilizer are stirred in a mixing tank at 120rpm for 6min to obtain component A;

[0099] (2) Component A is added from the main feed port, flame retardant is added from the upstream feed port, and glass fiber is added from the downstream feed port. The processing temperatures of each zone of the twin-screw extruder are 320°C for zone 1, 345°C for zone 2, 348°C for zone 3, 350°C for zone 4, 320°C for zone 5, 220°C for zone 6, 218°C for zone 7, 230°C for zone 8, 210°C for zone 9, and 300°C for the die head. The speed of the twin-screw extruder is 350 rpm. The mixture is melt-blended, extruded and granulated to obtain the nylon material.

[0100] Example 3

[0101] This embodiment provides a nylon material and its preparation method. The raw materials for preparing the nylon material include the following components by weight:

[0102] PA5T / 6T resin: 38 parts;

[0103] Diethylaluminum hypophosphite: 10 parts;

[0104] Stannous stearate: 0.3 parts;

[0105] Talc powder A: 1 part;

[0106] Antioxidant 9228: 0.4 parts;

[0107] Heat stabilizer: 0.3 parts;

[0108] Fiberglass: 50 parts;

[0109] The method for preparing the nylon material includes the following steps:

[0110] (1) PA5T / 6T resin baked at 125℃ for 4h, stannous stearate, talc A, antioxidant 9228 and heat stabilizer were stirred in a mixing tank at 120rpm for 4min to obtain component A;

[0111] (2) Component A is added from the main feed port, flame retardant is added from the upstream feed port, and glass fiber is added from the downstream feed port. The processing temperatures of each zone of the twin-screw extruder are 300℃ for zone 1, 330℃ for zone 2, 332℃ for zone 3, 335℃ for zone 4, 300℃ for zone 5, 200℃ for zone 6, 205℃ for zone 7, 210℃ for zone 8, 190℃ for zone 9, and 280℃ for the die head. The speed of the twin-screw extruder is 300 rpm. The mixture is melt-blended, extruded and granulated to obtain the nylon material.

[0112] Example 4

[0113] The only difference from Example 1 is that PA5T / 6T resin is replaced with an equal amount of PA6T / 66, while the amounts of other components and the preparation methods are the same as in Example 1.

[0114] Example 5

[0115] The difference from Example 1 is that the raw materials for preparing the nylon material include the following components by weight:

[0116] PA5T / 6T resin: 58 parts;

[0117] Diethylaluminum hypophosphite: 10 parts;

[0118] Stannous stearate: 0.1 parts;

[0119] Talc powder A: 2 parts;

[0120] Antioxidant 9228: 0.5 parts;

[0121] Heat stabilizer: 0.2 parts;

[0122] Fiberglass: 30 parts;

[0123] The preparation method is the same as in Example 1.

[0124] Example 6

[0125] The difference from Example 1 is that the raw materials for preparing the nylon material include the following components by weight:

[0126] PA5T / 6T resin: 58 parts;

[0127] Diethylaluminum hypophosphite: 9 parts;

[0128] Stannous stearate: 0.5 parts;

[0129] Talc powder A: 0.5 parts;

[0130] Antioxidant 9228: 0.2 parts;

[0131] Heat stabilizer: 0.4 parts;

[0132] Fiberglass: 30 parts;

[0133] The preparation method is the same as in Example 1.

[0134] Example 7

[0135] The only difference from Example 1 is that stannous stearate is replaced with an equal amount of stannous octoate, while the amounts of other components and the preparation methods are the same as in Example 1.

[0136] Example 8

[0137] The only difference from Example 1 is that the talc powder has a mesh size of 7500 and a particle size of 2.0 μm (Yirui Stone T10D). The amounts of the other components and the preparation methods are the same as in Example 1.

[0138] Comparative Example 1

[0139] The only difference from Example 1 is that the PA5T / 6T resin is replaced with an equal amount of PA66 resin, while the amounts of other components and the preparation methods are the same as in Example 1.

[0140] Comparative Example 2

[0141] The only difference from Example 1 is that the PA5T / 6T resin is replaced with an equal amount of PA66 resin, and stannous stearate and talc are not added. The amounts of the remaining components and the preparation methods are the same as in Example 1.

[0142] Comparative Example 3

[0143] The only difference from Example 1 is that stannous stearate is not added, while the amounts of other components and the preparation methods are the same as in Example 1.

[0144] Comparative Example 4

[0145] The only difference from Example 1 is that talc is not added, while the amounts of the remaining components and the preparation methods are the same as in Example 1.

[0146] Comparative Example 5

[0147] The only difference from Example 1 is that no antioxidant is added, while the amounts of the remaining components and the preparation methods are the same as in Example 1.

[0148] Comparative Example 6

[0149] The only difference from Example 1 is that the amount of talc is 4 parts, while the amount of the other components and the preparation method are the same as in Example 1.

[0150] Comparative Example 7

[0151] The only difference from Example 1 is that the amount of talc is 0.3 parts, while the amounts of the other components and the preparation methods are the same as in Example 1.

[0152] Performance testing

[0153] (1) Tensile strength: Tested according to ISO 527-2, using type 1A specimens, at a test speed of 5 mm / min.

[0154] (2) Tensile modulus: Tested according to ISO 527-2, using type 1A specimens, at a test speed of 5 mm / min.

[0155] (3) Elongation at break: Tested according to ISO 527-2, using type 1A specimens, at a test speed of 5 mm / min.

[0156] (4) Bending strength: Tested according to ISO 178, with a sample size of 80mm×10mm×4mm and a test speed of 2mm / min.

[0157] (5) Flexural modulus: Tested according to ISO 178, with a sample size of 80mm×10mm×4mm and a test speed of 2mm / min.

[0158] (6) Impact strength of cantilever beam with notch: Tested according to ISO 180, with a sample size of 80mm×10mm×4mm, a notch of 2mm, and an impact energy of 2.75J.

[0159] (7) Unnotched impact strength of cantilever beam: Tested according to ISO 180, with a sample size of 80mm×10mm×4mm and an impact energy of 5.5J.

[0160] (8) Flame retardancy: Tested according to UL 94, with sample size of 125mm×13mm and thickness of 1.5mm and 3.0mm.

[0161] (9) Aging resistance: The nylon material was aged in an environment of 200℃ for 1000h and the above mechanical properties were tested again.

[0162] The nylon materials provided in the examples and comparative examples were tested according to the above performance testing methods, and the results are shown in Tables 1-4:

[0163] Table 1. Basic properties of nylon materials in Examples 1-8

[0164]

[0165] Table 2 Basic properties of nylon materials in Comparative Examples 1-7

[0166]

[0167] Table 3. Retention rate of thermal aging properties of nylon materials in Examples 1-8

[0168]

[0169] Table 4. Retention rate of thermal aging properties of nylon materials in Comparative Examples 1-7

[0170]

[0171] As shown in the table above, this invention, through the compounding of various components, especially the synergistic effect of the organic acid stannous acid and talc, fundamentally eliminates the acidic environment that promotes the thermal degradation of PPA resin, effectively inhibiting the thermal degradation of PPA resin. This results in nylon materials with excellent aging resistance, flame retardancy, and mechanical properties, while also preventing the nylon materials from turning gray. The nylon materials prepared in Examples 1-6 of this invention have tensile strength > 160 MPa, tensile modulus > 12000 MPa, elongation > 2.1%, flexural strength > 230 MPa, flexural modulus > 9000 MPa, and cantilever beam notched impact strength > 10 KJ / m. 2 Unnotched impact strength of cantilever > 50 KJ / m 2 After aging at 200℃ for 1000 hours, the tensile strength, flexural strength, and cantilever beam notched impact strength retention rate of the nylon material are all greater than 70%, while the cantilever unnotched impact strength retention rate is greater than 40%.

[0172] As can be seen from the comparison between Example 1 and Example 7, if the carbon chain of the organic stannous acid is too short, its compatibility with the system is poor, which makes stannous octoate easy to precipitate or migrate, and cannot effectively inhibit the generation of acidic environment in the system, resulting in a decrease in mechanical properties and heat aging resistance. At the same time, stannous octoate does not have the lubricating properties of stannous stearate, and the excessive frictional heat between resins and shear heat with equipment during processing causes the particles to turn yellow.

[0173] As can be seen from the comparison between Example 1 and Example 8, if the mesh size of talc is too small, that is, the particle size is too large, its compatibility with PPA resin becomes poor, its dispersibility is poor during processing, and the talc generates additional heat while grinding the glass fiber into smaller pieces, resulting in a decrease in the strength of the material and yellowing of the particles, as well as a decrease in heat aging resistance.

[0174] The comparison between Example 1 and Comparative Examples 1-2 shows that when PA5T / 6T resin was replaced with an equal amount of PA66 resin in Comparative Example 1, the overall mechanical strength of the nylon material decreased. After aging at 200℃ for 1000h, the retention rate of mechanical properties was significantly lower than that of the nylon material prepared with PPA resin, and the heat aging resistance was poor. Comparative Example 2 shows that the nylon material prepared with PA66 will not turn gray even without the addition of stannous stearate and talc. This is because the PA66 synthesis process is mature, there are very few residual substances during the synthesis process, and the processing temperature is not high. At this temperature, less acidic substances are generated and the thermal degradation is more gradual than that of the PPA processing process.

[0175] The comparison between Example 1 and Comparative Examples 3-5 shows that only when stannous stearate and talc are used together can the nylon material have excellent mechanical properties and not turn gray or yellow. In Comparative Example 5, no antioxidant was added, and the nylon material turned yellow but not gray. The performance retention rate after thermal aging was also close to that of Example 1, which fully demonstrates that the antioxidant only plays a role in inhibiting yellowing. Stannous stearate and talc can inhibit the thermal degradation of PPA resin, so that the nylon material does not turn gray.

[0176] As can be seen from the comparison between Example 1 and Comparative Examples 6-7, the use of more talc powder leads to a decrease in mechanical properties, especially impact strength. The use of less talc powder cannot fully consume the acidic substances in the system, resulting in severe thermal degradation during processing, graying of nylon materials, and a decrease in heat aging resistance.

[0177] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A nylon material, characterized by, The raw materials for preparing the nylon material include the following components in parts by weight: PPA resin 30-65 parts; Flame retardant 8-15 parts; Stannous organic acid 0.1-0.5 parts; Talc 0.5-2 parts; Antioxidant 0.1-0.5 parts; Thermal stabilizer 0.2-0.4 parts; Glass fiber 25-50 parts.

2. The nylon material of claim 1, wherein, The stannous organic acid has a carbon number of C12-C20; Preferably, the stannous organic acid includes stannous stearate and / or stannous laurate.

3. The nylon material according to claim 1 or 2, characterized in that, The talc has a mesh number of 10000-12000; Preferably, the PPA resin includes any one or a combination of at least two of PA5T / 6T resin, PA6T / 66 resin, PA9T resin or PA10T resin.

4. The nylon material according to any one of claims 1-3, wherein, The flame retardant is a halogen-free flame retardant; Preferably, the flame retardant includes aluminum diethyl phosphinate.

5. The nylon material according to any one of claims 1-4, wherein, The antioxidant includes any one or a combination of at least two of tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, n-octadecanol β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite or bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite. Preferably, the thermal stabilizer includes a copper salt thermal stabilizer; Preferably, the thermal stabilizer includes a combination of cuprous iodide and potassium iodide.

6. A process for the production of a nylon material as claimed in any one of claims 1 to 5, characterised in that, The preparation method includes the following steps: (1) mixing PPA resin with stannous organic acid, talc, antioxidant and thermal stabilizer to obtain component A; (2) melt blending the component A, flame retardant and glass fiber, extruding and granulating to obtain the nylon material.

7. The production method according to claim 6, characterized by, The PPA resin is subjected to baking treatment; Preferably, the baking temperature is 115-125℃; Preferably, the baking time is 4-6h; Preferably, the rotation speed of the mixing is 80-120rpm; Preferably, the mixing time is 4-6min.

8. The production method according to claim 6 or 7, characterized by, The melt blending is performed in a twin-screw extruder; Preferably, the component A is added from a main feeding port, the flame retardant is added from an upstream side feeding port and the glass fiber is added from a downstream side feeding port.

9. The method of any one of claims 6-8, wherein, The rotation speed of the twin-screw extruder is 300-350rpm; Preferably, the processing temperature of each zone of the twin-screw extruder is zone 1 temperature 300-320℃, zone 2 temperature 330-350℃, zone 3 temperature 330-350℃, zone 4 temperature 330-350℃, zone 5 temperature 300-320℃, zone 6 temperature 200-220℃, zone 7 temperature 200-220℃, zone 8 temperature 210-230℃, zone 9 temperature 190-210℃ and die temperature 280-300℃; Preferably, the component A and flame retardant are added before zone 1 and the glass fiber is added at zone 5.

10. Use of the nylon material according to any one of claims 1-5 in automobiles, electronic appliances or household appliances.

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