Nylon composite material as well as preparation method and application thereof

Abstract

The invention discloses a nylon composite material as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The nylon composite material provided by the invention comprises the following components in parts by mass: 38-68 parts of nylon, 18-42 parts of glass fibers, 13-25 parts of a halogen-free flame retardant and 1-6 parts of a toughening agent, the nylon comprises at least one of PA6 and PA66, and the relative viscosity of the nylon is greater than or equal to 2.3; in the glass fiber, the mass percent of calcium oxide is less than or equal to 11.5%; the toughening agent comprises at least one of an ethylene-methacrylic acid-acrylate terpolymer and an ethylene-acrylic acid copolymer. The nylon composite material provided by the invention has excellent flame retardant property, deflection and low-temperature toughness.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a nylon composite material and a preparation method and application thereof. Background Art

[0002] At present, the commonly used nylon toughening agents in the market are mostly olefin materials, mainly PE, POE, and EPDM. The addition of such toughening agents in the halogen-free flame-retardant nylon system will cause the flame retardant properties of the nylon composite material to drop significantly, and the toughness improvement is very limited, which cannot achieve a good balance between flame retardancy and toughness. In addition, the nylon composite materials provided in the prior art cannot achieve good toughness at low temperatures, resulting in a limited application range. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a nylon composite material having excellent halogen-free flame retardancy, excellent flexibility and low-temperature toughness, and a preparation method and application thereof.

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

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

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

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

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

[0009] The nylon composite material provided by the present invention can achieve excellent deflection and good low-temperature toughness of the nylon composite material without damaging the halogen-free flame retardant effect of the nylon composite material by selectively adding glass fiber with a mass percentage of calcium oxide within a specific range and a specific type of toughening agent.

[0010] Specifically, the glass fiber within the specific calcium oxide mass percentage range has a higher modulus. In the glass fiber processing process, the addition of calcium oxide mainly plays the role of a flux, which can optimize the production process. At the same time, calcium ions can react with active groups such as hydroxyl groups on the surface of the glass fiber to form a dense protective layer, which plays a role in blocking moisture and oxygen, and prolongs the durability of the glass fiber. It is an indispensable raw material in the glass fiber manufacturing process. Selecting glass fibers with a suitable calcium oxide content and compounding them with PA6 and / or PA66 within a specific relative viscosity range can effectively help improve the deflection and low-temperature toughness of nylon composite materials, and the addition of the glass fiber will not have an adverse effect on the flame retardant effect of the halogen-free flame retardant. At least one of ethylene-methacrylic acid-acrylate terpolymer and ethylene-acrylic acid copolymer is selected as a toughening agent. On the one hand, the introduction of the ethylene segment in the above two toughening agents provides flexibility and polarity for the system, and the introduction of acrylic acid and / or methacrylic acid segments can react with the terminal amino groups on the nylon molecular chain to play a certain interface bonding role, thereby assisting the glass fiber to further improve the mechanical properties of the nylon composite material, especially the low-temperature toughness. On the other hand, the acrylic acid and / or methacrylic acid segments in the above two toughening agents can also react with the metal ions in the halogen-free flame retardant to play a certain cross-linking role, thereby improving the toughness and exerting a certain anti-dripping effect during the combustion process; in addition, the atomic C in the toughening agent can also promote combustion into carbon, that is, achieve a flame retardant synergistic effect; therefore, the selection of the toughening agent of the present invention can not only achieve the flame retardant effect without damaging it, but can also help improve the halogen-free flame retardant effect of the nylon composite material.

[0011] For example, the nylon may be any point value or any range value between 38-68 parts, such as 40-65 parts, or 38 parts, 40 parts, 42 parts, 45 parts, 48 ​​parts, 50 parts, 52 parts, 55 parts, 58 parts, 60 parts, 62 parts, 65 parts, 68 parts, etc.; the glass fiber may be any point value or any range value between 18-42 parts, such as 20-40 parts, or 18 parts, 20 parts, 22 parts, 25 parts, 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 13-25 parts, for example, it can be 15-23 parts, or it can be 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 1-6 parts, for example, it can be 2-5 parts, or it can be 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, in the nylon composite material, the mass percentage of nylon is 45-55%.

[0014] It should be noted that the relative viscosity of the nylon is obtained by testing with reference to ISO 307:2007.

[0015] Exemplarily, the relative viscosity of the nylon may be any point value or any two-point range value ≥2.3, such as 2.3-2.8, 2.3-3.2, 2.3-2.7, etc., 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 is obtained by testing using X-ray fluorescence spectroscopy.

[0017] Exemplarily, the mass percentage of calcium oxide in the high-performance glass fiber can be any point value ≤11.5% or any two-point range value, such as 1-11.0%, 4-11%, 8-11%, 8-10%, etc., or can be 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 is obtained by testing using a two-dimensional measurement technique, and the average diameter is obtained by testing using a metallographic microscope.

[0020] The present invention has no special requirements on the length and average diameter of the glass fiber, and the effects of the present invention can be achieved within the range given by the present invention.

[0021] It should be noted that the mass percentage of silicon oxide in the glass fiber is 50-60%, and the mass percentage of aluminum oxide is 2-3%.

[0022] The present invention has no special requirements on the mass percentage content of silicon oxide, aluminum oxide and other substances in the glass fiber. As long as it is within the range given by the present invention, the effect of the present invention can be achieved.

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

[0024] The present 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, the glass fiber and toughening agent can be better dispersed in the nylon matrix, thereby providing better support, flexibility and polarity for the system, and can also fully interact with the halogen-free flame retardant and the terminal amino group in the nylon molecule, thereby achieving a more excellent comprehensive effect of 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 of nylon, 25-30 parts of glass fiber, 15-20 parts of halogen-free flame retardant, and 3-4 parts of toughening agent.

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

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

[0028] Exemplarily, the mass ratio of PA6 to PA66 may be any point value or any range value 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] The present invention has found that when nylon contains PA66, the introduction of a certain amount of PA6 can effectively improve the comprehensive performance of the product; specifically, the proportion of PA6 and PA66 in nylon will affect the strength and toughness of the nylon composite material, and will also affect its interaction with the toughening agent, glass fiber and halogen-free flame retardant. When the mass ratio of PA6 and PA66 is further selected to be 1: (0.1-1.2), especially 1: (0.3-0.4), the deflection and low-temperature toughness of the obtained product are better.

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

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

[0033] As 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 are obtained by mass spectrometry.

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

[0036] The present invention has been found to have no particular limitation on the mass percentage of methacrylic acid in the ethylene-methacrylic acid-acrylate terpolymer and the mass percentage of acrylic acid in the ethylene-acrylic acid copolymer, and 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] Exemplarily, 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 comprises diethylphosphinate 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 hypophosphite to aluminum phosphite is (3-5):1.

[0043] Exemplarily, the mass ratio of diethyl hypophosphite and melamine polyphosphate can be any point value or any two point range values ​​between (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] Exemplarily, the mass ratio of diethyl hypophosphite to aluminum phosphite may be any point value or any range value between (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 comprises the following components in parts by weight: 0.1-2 parts of an antioxidant and 0.1-2 parts of a lubricant.

[0046] Illustratively, the antioxidant may be at least one of a hindered phenol antioxidant, a hindered amine antioxidant, a thioester antioxidant, a phosphite antioxidant, and an inorganic phosphate.

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

[0048] In the second aspect of the present invention, the present invention also provides a method for preparing the nylon composite material, the preparation method comprising the following steps: mixing the components and melt-extruding 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: the aspect ratio of the twin-screw extruder is (36-48):1, the screw speed is 250-450rpm, and the extrusion temperature is 220-300°C.

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

[0051] For example, nylon composite materials are used in the preparation of high-voltage connectors, industrial connectors, circuit breaker housings, switches and other materials.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The nylon composite material provided by the present invention can achieve excellent deflection and good low-temperature toughness of the nylon composite material without damaging the halogen-free flame retardant effect of the nylon composite material by selectively adding glass fiber within a specific calcium oxide mass percentage range and a specific type of toughening agent; specifically, the flame retardant grade of the obtained product is V0 grade, and the tensile strength is above 117MPa, the bending strength is above 178MPa, the deflection is above 6.7mm, and the cantilever notched impact strength at room temperature (23°C) is 11.5KJ / m 2 Above, the cantilever notch impact strength at low temperature (-30℃) is 8.0KJ / m 2 At the same time, the preparation method of the nylon composite material provided by the present invention is simple to operate and is conducive to actual production. DETAILED DESCRIPTION

[0054] In order to better illustrate the purpose, technical solutions 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 the present invention are all conventional reagents, methods and equipment in the art; and unless otherwise specified, the raw materials used in parallel experiments are from the same batch of raw materials.

[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 mass percentage of calcium oxide is 11%, Taishan fiberglass;

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

[0066] Toughener 1: Ethylene-methacrylic acid-acrylate copolymer, AN4228C, methacrylic acid mass percentage is 4%, DuPont;

[0067] Toughener 2: Ethylene-acrylic acid copolymer, EAA3990, acrylic acid mass percentage is 9.5%, DuPont;

[0068] Toughener 3: ethylene-acrylic acid copolymer, EAA5070, acrylic acid mass percentage is 10%, ExxonMobil;

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

[0070] Halogen-free flame retardant 1: a compound of diethyl aluminum phosphinate and melamine polyphosphate in a mass ratio of 6:1.6;

[0071] Halogen-free flame retardant 2: a compound formed by a mass ratio of aluminum diethylphosphinate: melamine polyphosphate: zinc borate = 6:1:0.5;

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

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

[0074] Lubricant: montan ester, commercially available.

[0075] The antioxidant, lubricant, aluminum diethylphosphinate and melamine phosphate used in the parallel experiments of the embodiments and comparative examples remain consistent.

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

[0077] The present invention provides a nylon composite material according to the embodiment and comparative example. The component contents (parts by weight) of the nylon composite material are shown in Table 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 / / / / Glass fiber1 25 25 / 25 65 25 Glass Fiber 4 / / 25 / / / Toughener 1 4 4 4 / 4 10 Toughener 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 Lubricants 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:

[0086] The dried raw materials are weighed, mixed and fed into a twin-screw extruder, and subjected to extrusion, strand drawing, cooling, pelletizing and drying to obtain a nylon composite material;

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

[0088] The preparation methods of the nylon composite materials provided in Examples 2-16 and Comparative Examples 1-6 are consistent with that in Example 1, except that no relevant components are added.

[0089] Effect example

[0090] The effect examples of the present invention verify the performance of the products prepared in the embodiments and comparative examples; the test items include the following aspects:

[0091] 1. Deflection: After drying the prepared nylon composite material in an oven at 120°C for 4 h, the standard bending specimens were injection molded according to ISO standards and tested according to ISO 178:2010;

[0092] 2. -30℃ Izod notched impact strength: After drying the prepared nylon composite material in a 120℃ oven for 4 hours, injection mold a standard Izod notched impact specimen according to ISO standard, freeze at -30℃ for 4 hours, take out and test within 10 seconds, test according to ISO180:2019;

[0093] 3. UL94 vertical burning @1.6mm: After the prepared nylon composite material was dried in an oven at 120°C for 4 hours, 1.6mm thick UL flame retardant specimens were injection molded and tested according to the UL94 standard;

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

[0095] Table 4

[0096]

[0097]

[0098] It can be seen from Table 4 that when the technical solution of the present invention is adopted, the obtained products have excellent deflection and low-temperature toughness, and also have good flame retardancy; specifically, the flame retardancy grade of the obtained products is V0 grade, and the deflection is above 6.7mm, and the cantilever notched impact strength at low temperature (-30°C) is 8.0KJ / m 2 above;

[0099] It can be seen from Examples 2-5 and Comparative Examples 5-6 that the mass fraction of the components will have a significant impact on the performance of the product. When the amount of glass fiber added in Comparative Example 5 is too much, the deflection of the obtained product decreases significantly, only 4.2 mm; when the amount of toughening agent added in Comparative Example 6 is too much, the obtained product cannot meet the V0 flame retardant grade;

[0100] It can be seen from Examples 1, 3 and 8-10 that the mass ratio of PA6 and PA66 in the selection of nylon will also affect the performance of the product. When the mass ratio of PA6 and PA66 is further selected within the range given in the present invention, the comprehensive performance of the obtained product is better. It can be seen from Example 3, Examples 6-7 and Comparative Examples 1-2 that the relative viscosity of nylon will affect the performance of the product. 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 obvious downward trend of the deflection and the notched impact strength of the cantilever beam at low temperature.

[0101] It can be seen from Example 3, Examples 11-12 and Comparative Example 3 that the mass percentage of calcium oxide in the glass fiber will also affect the comprehensive 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 the present invention, the low-temperature toughness of the obtained product decreases significantly;

[0102] It can be seen from Example 3, Examples 13-14 and Comparative Example 4 that the selection of toughening agent will also affect the performance of the product. When the toughening agent added in Comparative Example 4 is not of the type given in the present invention, the flame retardancy of the obtained product cannot meet the V0 flame retardancy grade.

[0103] Finally, it should be noted that the above embodiments are intended to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A nylon composite material, characterized in that: The nylon composite material comprises the following components in parts by weight: 38-68 parts of nylon, 18-42 parts of glass fiber, 13-25 parts of halogen-free flame retardant, 1-6 parts of 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-methacrylic acid-acrylate terpolymer and ethylene-acrylic acid copolymer.

2. The nylon composite material according to claim 1, characterized in that: 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 of nylon, 25-30 parts of glass fiber, 15-20 parts of halogen-free flame retardant, and 3-4 parts of 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, and the mass ratio of the diethyl hypophosphite to the melamine polyphosphate is (5-7): (1.2-1.8); And / or, the halogen-free flame retardant comprises diethyl hypophosphite and aluminum phosphite, and the mass ratio of the diethyl hypophosphite to the aluminum phosphite is (3-5):

1.

7. The nylon composite material according to claim 1, characterized in that: The nylon composite material further comprises the following components in parts by weight: 0.1-2 parts of an antioxidant and 0.1-2 parts of a lubricant.

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

9. Use of the nylon composite material according to any one of claims 1 to 7 in the preparation of new energy and low-voltage electrical equipment.

Images