Nylon composite material and preparation method and application thereof

Abstract

This invention discloses a nylon composite material, its preparation method, and its applications, belonging to the field of polymer materials technology. The nylon composite material provided by this invention comprises the following components in parts by weight: 38-68 parts nylon, 18-42 parts glass fiber, 13-25 parts halogen-free flame retardant, and 1-6 parts toughening agent. The nylon includes at least one of PA6 and PA66, and the relative viscosity of the nylon is ≥2.3. In the glass fiber, the mass percentage of calcium oxide is ≤11.5%. The toughening agent includes at least one of ethylene-methacrylate-acrylate terpolymer and ethylene-acrylic acid copolymer. The nylon composite material provided by this invention exhibits excellent flame retardant properties, flexibility, and low-temperature toughness.

Description

Technical Field

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

[0002] Currently, most commonly used nylon toughening agents on the market are olefin-based materials, primarily PE, POE, and EPDM. Adding these toughening agents to halogen-free flame-retardant nylon systems leads to a significant decrease in the flame-retardant properties of the nylon composite material, while providing only a very limited improvement in toughness, failing to achieve a good balance between flame retardancy and toughness. Furthermore, existing nylon composite materials cannot achieve good toughness at low temperatures, resulting in limited application range. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a nylon composite material with excellent halogen-free flame retardant properties, excellent flexibility and low-temperature toughness, as well as its preparation method and application.

[0004] To achieve the above objectives, in a first aspect, the present invention provides a nylon composite material comprising the following components in parts by weight:

[0005] 38-68 parts nylon, 18-42 parts glass fiber, 13-25 parts halogen-free flame retardant, 1-6 parts toughening agent;

[0006] The nylon includes at least one of PA6 and PA66, and the relative viscosity of the nylon is ≥2.3;

[0007] The mass percentage of calcium oxide in the glass fiber is ≤11.5%;

[0008] The toughening agent includes at least one of ethylene-methacrylate-acrylate terpolymer and ethylene-acrylic acid copolymer.

[0009] The present invention provides a nylon composite material that, by selecting glass fibers with a calcium oxide mass percentage within a specific range and combining them with a specific type of toughening agent, can achieve excellent flexibility and good low-temperature toughness of the nylon composite material without compromising its halogen-free flame-retardant effect.

[0010] Specifically, glass fibers with a specific calcium oxide mass percentage range possess high modulus. During glass fiber processing, the addition of calcium oxide primarily acts as a flux, optimizing the production process. Simultaneously, calcium ions react with active groups such as hydroxyl groups on the glass fiber surface to form a dense protective layer, effectively blocking moisture and oxygen, thus extending the durability of the glass fiber. Calcium oxide is an essential raw material in glass fiber manufacturing. Selecting glass fibers with appropriate calcium oxide content and blending them with PA6 and / or PA66 within a specific relative viscosity range can effectively improve the flexibility and low-temperature toughness of nylon composites. Furthermore, the addition of this glass fiber does not adversely affect the flame-retardant effect of the halogen-free flame retardant. Choosing at least one of ethylene-methacrylic acid-acrylate terpolymer and ethylene-acrylic acid copolymer as a toughening agent provides flexibility and polarity through the introduction of ethylene segments, while acrylic and / or methacrylic acid segments react with the terminal amino groups on the nylon molecular chains, creating an interfacial bonding effect. This further assists the glass fiber in enhancing the mechanical properties of nylon composites, especially their low-temperature toughness. On the other hand, the acrylic acid and / or methacrylic acid segments in the two toughening agents mentioned above can also react with the metal ions in the halogen-free flame retardant to play a certain cross-linking role, thereby improving toughness and playing a certain anti-dripping effect during combustion. In addition, the carbon atoms in the toughening agent can also promote combustion into char, thus achieving a flame retardant synergistic effect. Therefore, choosing the toughening agent of the present invention can not only achieve the flame retardant effect without damaging it, but also help improve the halogen-free flame retardant effect of nylon composite materials.

[0011] For example, the nylon can be any point value or any two-point range value between 38 and 68 parts, such as 40-65 parts, or 38, 40, 42, 45, 48, 50, 52, 55, 58, 60, 62, 65, 68, etc.; the glass fiber can be any point value or any two-point range value between 18 and 42 parts, such as 20-40 parts, or 18, 20, 22, 25 parts, etc. 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, etc.; the halogen-free flame retardant can be any point value or any two-point range value between 13 and 25 parts, for example, it can be 15-23 parts, or 13 parts, 15 parts, 17 parts, 19 parts, 21 parts, 23 parts, 25 parts, etc.; the toughening agent can be any point value or any two-point range value between 1 and 6 parts, for example, it can be 2-5 parts, or 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, etc.

[0012] In the nylon composite material, the mass percentage of nylon is ≥33%.

[0013] Preferably, the mass percentage of nylon in the nylon composite material is 45-55%.

[0014] It should be noted that the relative viscosity of the nylon was obtained by testing in accordance with ISO 307:2007.

[0015] For example, the relative viscosity of the nylon can be any point value or any two-point range value of ≥2.3, such as 2.3-2.8, 2.3-3.2, 2.3-2.7, or 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, etc.

[0016] It should be noted that the mass percentage of calcium oxide in the glass fiber was obtained by X-ray fluorescence spectroscopy.

[0017] For example, the mass percentage of calcium oxide in the high-performance glass fiber can be any point value or any two points within a range of ≤11.5%, such as 1-11.0%, 4-11%, 8-11%, 8-10%, etc., or 11.5%, 11.4%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, etc.

[0018] Preferably, the glass fiber has a length of 3.0-4.5 mm and an average diameter of 8-10 μm.

[0019] It should be noted that the length of the glass fiber was obtained by two-dimensional measurement technology, and the average diameter was obtained by metallographic microscopy.

[0020] This invention does not have special requirements for the length and average diameter of the glass fibers; the effects of this invention can be achieved within the range given in this invention.

[0021] It should be noted that the glass fiber contains 50-60% silicon dioxide and 2-3% aluminum oxide by mass.

[0022] This invention does not have any special requirements on the mass percentage content of substances such as silicon oxide and aluminum oxide in glass fibers; as long as it is within the range given in this invention, the effects of this invention can be achieved.

[0023] In a preferred embodiment of the nylon composite material of the present invention, the relative viscosity of the nylon is 2.5-2.8.

[0024] This invention has found that the relative viscosity of nylon affects its compatibility with glass fiber and toughening agent. When the relative viscosity of nylon is further selected to be 2.5-2.8, glass fiber and toughening agent can be better dispersed in the nylon matrix, thereby providing better support, flexibility and polarity to the system. It can also fully interact with the halogen-free flame retardant and the terminal amino groups in the nylon molecule, thus achieving a better overall effect for the nylon composite material.

[0025] As a preferred embodiment of the nylon composite material of the present invention, the nylon composite material comprises the following components in parts by weight: 45-60 parts nylon, 25-30 parts glass fiber, 15-20 parts halogen-free flame retardant, and 3-4 parts toughening agent.

[0026] The present invention has found that the proportions of nylon, glass fiber, halogen-free flame retardant and toughening agent in nylon composite materials affect the interaction between the components. When the proportions of nylon, glass fiber, halogen-free flame retardant and toughening agent are further selected within the above range, the resulting nylon composite material has better deflection and low-temperature toughness.

[0027] In a preferred embodiment of the nylon composite material of the present invention, the nylon includes PA6 and PA66, and the mass ratio of PA6 and PA66 is 1:(0.1-1.2).

[0028] For example, the mass ratio of PA6 and PA66 can be any point value or any two points between 1:(0.1-1.2), such as 1:0.1, 1:0.3, 1:0.5, 1:0.7, 1:0.9, 1:1.2, etc.

[0029] Preferably, the mass ratio of PA6 to PA66 is 1:(0.3-0.4).

[0030] This invention has found that when nylon contains PA66, introducing a certain amount of PA6 can effectively improve the overall performance of the product. Specifically, the ratio of PA6 to PA66 in nylon affects the strength and toughness of the nylon composite material, as well as its interaction with toughening agents, glass fibers, and halogen-free flame retardants. When the mass ratio of PA6 to PA66 is further selected to be 1:(0.1-1.2), especially 1:(0.3-0.4), the resulting product has better deflection and low-temperature toughness.

[0031] In a preferred embodiment of the nylon composite material of the present invention, the mass percentage of methacrylic acid in the ethylene-methacrylic acid-acrylate terpolymer is 3-12%.

[0032] For example, in the ethylene-methacrylic acid-acrylate terpolymer, the mass percentage of methacrylic acid can be any point value or any two points between 3 and 12%, such as 4-10%, 4-9.5%, 4-9%, or 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, etc.

[0033] In a preferred embodiment of the nylon composite material of the present invention, the mass percentage of acrylic acid in the ethylene-acrylic acid copolymer is 3-12%.

[0034] It should be noted that the mass percentages of methacrylic acid in the ethylene-methacrylic acid-acrylate terpolymer and acrylic acid in the ethylene-acrylic acid copolymer were obtained by mass spectrometry.

[0035] For example, in the ethylene-acrylic acid copolymer, the mass percentage of acrylic acid can be any point value or any two points between 3 and 12%, such as 4-10%, 4-9.5%, 4-9%, etc., or 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, etc.

[0036] The present invention has found that it does not impose any particular limitation on the mass percentage of methacrylic acid in the ethylene-methacrylic acid-acrylate terpolymer or on the mass percentage of acrylic acid in the ethylene-acrylic acid copolymer. The corresponding effects of the present invention can be achieved within the range of 3-12% given in the present invention.

[0037] As a preferred embodiment of the nylon composite material of the present invention, the halogen-free flame retardant includes at least one of diethyl hypophosphite, melamine polyphosphate, zinc borate, and aluminum phosphite.

[0038] For example, the diethyl hypophosphite includes at least one of diethyl aluminum hypophosphite, diethyl zinc hypophosphite, and diethyl titanium hypophosphite.

[0039] Preferably, the halogen-free flame retardant includes diethylphosphonate and melamine polyphosphate.

[0040] Preferably, the halogen-free flame retardant comprises diethyl hypophosphite and aluminum phosphite.

[0041] More preferably, the mass ratio of the diethyl hypophosphite to the melamine polyphosphate is (5-7):(1.2-1.8).

[0042] More preferably, the mass ratio of the diethyl phosphite to aluminum phosphite is (3-5):1.

[0043] For example, the mass ratio of diethyl hypophosphite to melamine polyphosphate can be any point value or any two points within the range of (5-7):(1.2-1.8), such as 5:1.2, 6:1.2, 7:1.2, 5:1.4, 6:1.4, 7:1.4, 5:1.6, 6:1.6, 7:1.6, 5:1.8, 6:1.8, 7:1.8, etc.

[0044] For example, the mass ratio of diethyl hypophosphite to aluminum phosphite can be any point value or any two points within the range of (3-5):1, such as 3:1, 3.5:1, 4:1, 4.5:1, 5:1, etc.

[0045] As a preferred embodiment of the nylon composite material of the present invention, the nylon composite material further includes the following components in parts by weight: 0.1-2 parts antioxidant and 0.1-2 parts lubricant.

[0046] For example, the antioxidant may be at least one of hindered phenolic antioxidants, hindered amine antioxidants, thioester antioxidants, phosphite antioxidants, and inorganic phosphates.

[0047] For example, the lubricant may be at least one of silicone masterbatch, polyethylene wax, stearate, and ethylene bis-fatty acid amide.

[0048] In a second aspect, the present invention also provides a method for preparing the nylon composite material, the method comprising the following steps: mixing and melting the components and extruding them to obtain the nylon composite material.

[0049] As a preferred embodiment of the preparation method of the present invention, the parameters of the twin-screw extruder are as follows: the length-to-diameter ratio of the twin-screw extruder is (36-48):1, the screw speed is 250-450 rpm, and the extrusion temperature is 220-300℃.

[0050] In a third aspect, the present invention also provides the application of the nylon composite material in the preparation of devices for new energy and low-voltage electrical applications.

[0051] Examples include the application of nylon composite materials in the manufacture of high-voltage connectors, industrial connectors, circuit breaker housings, switches, and other materials.

[0052] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0053] This invention provides a nylon composite material that, by selectively adding glass fibers within a specific mass percentage range of calcium oxide and a specific type of toughening agent, achieves excellent flexibility and good low-temperature toughness of the nylon composite material without compromising its halogen-free flame-retardant properties. Specifically, the resulting products all have a V0 flame retardant rating, a tensile strength above 117 MPa, a flexural strength above 178 MPa, a deflection above 6.7 mm, and a cantilever notched impact strength of 11.5 KJ / m at room temperature (23℃). 2 The above indicates that the cantilever notched impact strength at low temperature (-30℃) is 8.0 KJ / m. 2 That's all. Furthermore, the preparation method of the nylon composite material provided by this invention is simple to operate and beneficial for actual production. Detailed Implementation

[0054] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0055] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in the field; and unless otherwise specified, the raw materials used in parallel experiments are from the same batch.

[0056] Nylon 1: PA66, PA66 U3600 NC01, relative viscosity 2.4, Invista;

[0057] Nylon 2: PA6, HY-2500A, relative viscosity 2.5, Haiyang Chemical Fiber;

[0058] Nylon 3: PA6, HY-2800A, relative viscosity 2.8, Haiyang Chemical Fiber;

[0059] Nylon 4: PA6, PA6 M3400, relative viscosity 3.4, Xinhui Meida;

[0060] Nylon 5: PA6, HY-2000A, relative viscosity 2.0, Haiyang Chemical Fiber;

[0061] Nylon 6: PA66, PA66 U2501 NC01, relative viscosity 2.0, Invista;

[0062] Glass fiber 1: E7CS10-03-568H, calcium oxide mass percentage is 10%, China Jushi;

[0063] Glass fiber 2: E8CS10-03-568H, calcium oxide mass percentage is 8%, China Jushi;

[0064] Glass fiber 3: S-1HM TM The calcium oxide content is 11% by mass, and the fiberglass is made from Taishan fiberglass.

[0065] Glass fiber 4: DCS10-3.0-116A, calcium oxide mass percentage is 15%, Changhai Shares;

[0066] Toughening agent 1: Ethylene-methacrylic acid-acrylate copolymer, AN4228C, 4% methacrylic acid by mass, DuPont;

[0067] Toughening agent 2: Ethylene-acrylic acid copolymer, EAA3990, acrylic acid content 9.5% (by weight), DuPont;

[0068] Toughening agent 3: Ethylene-acrylic acid copolymer, EAA5070, acrylic acid 10% by mass, ExxonMobil;

[0069] Toughening agent 4: Maleic anhydride grafted ethylene-octene copolymer, KT-915, Shenyang Ketong;

[0070] Halogen-free flame retardant 1: A compound formed by aluminum diethylphosphinate and melamine polyphosphate in a mass ratio of 6:1.6;

[0071] Halogen-free flame retardant 2: A compound formed by aluminum diethylphosphinic acid, melamine polyphosphate, and zinc borate in a mass ratio of 6:1:0.5;

[0072] Halogen-free flame retardant 3: A compound of aluminum diethylphosphinate and aluminum phosphite in a 4:1 mass ratio, Exoplit OP1400, Clariant;

[0073] Antioxidant: A commercially available mixture of IRGANOX 1098 and Revonox 608 in a 1:1 mass ratio;

[0074] Lubricant: Mondan ester, commercially available.

[0075] The antioxidants, lubricants, aluminum diethylphosphonate, and melamine phosphate used in the parallel experiments of the examples and comparative examples were consistent.

[0076] Examples 1-16 and Comparative Examples 1-6

[0077] The present invention provides a nylon composite material in the embodiments and comparative examples, wherein the component content (parts by weight) of the nylon composite material is shown in Tables 1-3;

[0078] Table 1

[0079]

[0080] Table 2

[0081]

[0082]

[0083] Table 3

[0084] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Nylon 2 / / 48 48 48 48 Nylon 5 48 / / / / / Nylon 6 / 48 / / / / Fiberglass 1 25 25 / 25 65 25 Fiberglass 4 / / 25 / / / Toughening agent 1 4 4 4 / 4 10 Toughening agent 4 / / / 4 / / Halogen-free flame retardant 1 18 18 18 18 18 18 antioxidants 0.2 0.2 0.2 0.2 0.2 0.2 lubricant 0.5 0.5 0.5 0.5 0.5 0.5

[0085] The preparation method of the nylon composite material provided in Example 1 is as follows:

[0086] After drying, the raw materials are weighed and mixed, then fed into a twin-screw extruder. After extrusion, stranding, cooling, pelletizing, and drying, nylon composite material is obtained.

[0087] The parameters of the twin-screw extruder are as follows: the length-to-diameter ratio of the twin-screw extruder is 40:1, the screw speed is 350 rpm, and the extrusion temperature is 250℃.

[0088] The preparation methods of the nylon composite materials provided in Examples 2-16 and Comparative Examples 1-6 are consistent with those in Example 1, except that the relevant components are not added.

[0089] Example of effect

[0090] The performance of the products prepared in the embodiments and comparative examples of this invention is verified by the following test items:

[0091] 1. Deflection: After drying the prepared nylon composite material in an oven at 120℃ for 4 hours, a standard bending specimen was injection molded according to ISO standard, and tested according to ISO 178:2010.

[0092] 2. -30℃ cantilever beam notched impact strength: The prepared nylon composite material was dried in an oven at 120℃ for 4 hours, and then a standard cantilever beam notched impact specimen was injection molded according to ISO standard. It was then frozen at -30℃ for 4 hours and tested within 10 seconds after being taken out. The test was conducted according to ISO180:2019.

[0093] 3. UL94 Vertical Burning @ 1.6mm: After drying the prepared nylon composite material in an oven at 120℃ for 4 hours, a 1.6mm thick UL flame-retardant sample was injection molded and tested according to the UL94 standard.

[0094] The test results are shown in Table 4.

[0095] Table 4

[0096]

[0097]

[0098] As can be seen from Table 4, when the technical solution of this invention is adopted, the obtained product has excellent flexibility and low-temperature toughness, and also has good flame retardancy; specifically, the flame retardancy rating of the obtained product is V0, the flexibility is above 6.7 mm, and the cantilever notched impact strength at low temperature (-30℃) is 8.0 KJ / m. 2 above;

[0099] As can be seen from Examples 2-5 and Comparative Examples 5-6, the mass fraction of the components has a significant impact on the performance of the product. When the amount of glass fiber added in Comparative Example 5 is too large, the deflection of the obtained product decreases significantly, reaching only 4.2 mm. When the amount of toughening agent added in Comparative Example 6 is too large, the obtained product cannot meet the V0 flame retardant rating.

[0100] As can be seen from Examples 1, 3, and 8-10, the mass ratio of PA6 to PA66 in the nylon selection also affects the product performance. When the mass ratio of PA6 to PA66 is further selected within the range given in this invention, the overall performance of the obtained product is better. As can be seen from Examples 3, 6-7, and Comparative Examples 1-2, the relative viscosity of nylon affects the product performance. When the relative viscosity of nylon in Comparative Examples 1-2 is too low, the overall mechanical properties of the obtained product are low, which is reflected in the significant decrease in deflection and the notched impact strength of the cantilever beam at low temperature.

[0101] As can be seen from Examples 3, 11-12 and Comparative Example 3, the mass percentage of calcium oxide in glass fiber can affect the overall performance of the product to a certain extent; when the mass percentage of calcium oxide in the glass fiber added in Comparative Example 3 is not within the range given in this invention, the low-temperature toughness of the obtained product decreases significantly.

[0102] As can be seen from Examples 3, 13-14 and Comparative Example 4, the choice of toughening agent also affects the performance of the product. When the toughening agent added in Comparative Example 4 is not of the type given in this invention, the flame retardancy of the obtained product cannot meet the V0 flame retardancy rating.

[0103] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A nylon composite, characterized by, The nylon composite material comprises the following components in parts by weight: 38-68 parts nylon, 18-42 parts glass fiber, 13-25 parts halogen-free flame retardant, 2-6 parts toughening agent; The nylon includes at least one of PA6 and PA66, and the relative viscosity of the nylon is ≥2.3; The mass percentage of calcium oxide in the glass fiber is ≤11.5%; The toughening agent includes at least one of ethylene-methacrylate-acrylate terpolymer and ethylene-acrylic acid copolymer.

2. The nylon composite of claim 1, wherein, The relative viscosity of the nylon is 2.5-2.

8.

3. The nylon composite material according to claim 1, characterized in that, The nylon composite material comprises the following components in parts by weight: 45-60 parts nylon, 25-30 parts glass fiber, 15-20 parts halogen-free flame retardant, and 3-4 parts toughening agent.

4. The nylon composite material according to claim 1, characterized in that, The nylon includes PA6 and PA66, and the mass ratio of PA6 to PA66 is 1:(0.1-1.2).

5. The nylon composite material according to claim 1, characterized in that, The halogen-free flame retardant includes at least one of diethyl hypophosphite, melamine polyphosphate, zinc borate, and aluminum phosphite.

6. The nylon composite material according to claim 5, characterized in that, The halogen-free flame retardant comprises diethyl hypophosphite and melamine polyphosphate, wherein the mass ratio of diethyl hypophosphite to melamine polyphosphate is (5-7):(1.2-1.8). And / or, the halogen-free flame retardant comprises diethyl hypophosphite and aluminum phosphite, wherein the mass ratio of diethyl hypophosphite to aluminum phosphite is (3-5):

1.

7. The nylon composite material according to claim 1, characterized in that, The nylon composite material also includes the following components in parts by weight: 0.1-2 parts antioxidant and 0.1-2 parts lubricant.

8. The method for preparing the nylon composite material according to any one of claims 1-7, characterized in that, The preparation method includes the following steps: mixing and melting the components and extruding them to obtain a nylon composite material.

9. The application of the nylon composite material as described in any one of claims 1-7 in the preparation of devices for new energy and low-voltage electrical applications.

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