WO2023109490A1 - Flame-retardant nylon composite material and preparation method therefor and application thereof - Google Patents

Abstract

A flame-retardant nylon composite material and a preparation method therefor and an application thereof. The flame-retardant nylon composite material comprises components such as a nylon resin and an aromatic dicarboxylic acid. In the flame-retardant nylon composite material provided by the present solution, a specific nylon resin is taken as a base material, and meanwhile, a small amount of aromatic dicarboxylic acids is added for flame-retardant modification, such that a stable flame-retardant V-2 grade can be reached, and negative influence on the mechanical property of the flame-retardant nylon composite material is also avoided.

Description

A kind of flame-retardant nylon composite material and its preparation method and application technical field

The invention belongs to the application field of engineering plastics, and in particular relates to a flame-retardant nylon composite material and a preparation method and application thereof.

Background technique

Nylon has the advantages of excellent electrical properties (CTI, electrical breakdown strength) and low price, and is widely used in electronic and electrical industries. Melamine cyanurate is a very effective flame retardant for nylon, but due to the interaction between melamine cyanurate and nylon, it affects the processing stability of nylon. Nylon materials are prone to changes in crystallinity when heated, which will also affect the flame-retardant stability of nylon materials.

Existing patents have disclosed a MAC flame-retardant nylon 66 composite material, using MAC (melamine cyanurate) as a flame retardant, and using a long carbon chain monobasic saturated carboxylic acid compound or a long carbon chain dibasic saturated carboxylic acid compound with a specific number of carbon atoms. As a flame retardant stabilizer, the carboxylic acid compound can reach the flame retardant V-0 grade; at the same time, it points out that if no flame retardant stabilizer is added, it can only reach the V-2 grade. But it still uses melamine cyanurate as a flame retardant, and its flame retardant stability is not good. Moreover, the addition of a long carbon chain monobasic saturated carboxylic acid compound or a long carbon chain dibasic saturated carboxylic acid compound with a specific number of carbon atoms will also have a negative impact on the mechanical properties of the nylon material.

Therefore, it is of great significance to develop a nylon material with better mechanical properties, flame retardant properties and flame retardant stability.

Contents of the invention

The purpose of the present invention is to overcome the defects or insufficiencies that the nylon material in the prior art uses melamine cyanurate as a flame retardant, and the compound flame retardant stabilizer has poor flame retardant stability and affected mechanical properties. Burning nylon composite. The flame-retardant nylon composite material provided by the present invention uses a specific nylon resin as the base material, and at the same time adds a small amount of aromatic dicarboxylic acid for flame-retardant modification. The mechanical properties of the nylon composites were not negatively affected.

Another object of the present invention is to provide a method for preparing the above flame-retardant nylon composite material.

Another object of the present invention is to provide the application of the flame-retardant nylon composite material in the preparation of 3D printing consumables.

In order to realize the above-mentioned purpose of the invention, the present invention adopts following technical scheme:

A flame-retardant nylon composite material, comprising the following components in parts by weight:

Nylon resin 97～99.95 parts;

Aromatic dicarboxylic acid 0.05-2 parts;

The oligomer content in the nylon resin is not higher than 1.6%.

The inventors of the present invention have found that if only C _{8 ~ 18} long carbon chain monobasic saturated carboxylic acid compounds or C _{8 ~ 18} long carbon chain dibasic saturated carboxylic acid compounds are added to modify the nylon material, although its flame retardant grade can be improved. It reaches the V-2 grade, but its flame retardancy is poor, and it cannot maintain the V-2 grade after being treated at 70°C for 168 hours, and has a relatively large negative impact on the mechanical properties.

After repeated research, it was found that when nylon resin with a low oligomer content is selected as the base material and aromatic dicarboxylic acid is added to modify the nylon material, only a small amount of addition can reach the flame retardant V-2 level. And after being treated at 70°C for 168 hours, it can still maintain the flame retardant V-2 grade, which has excellent flame retardant stability; in addition, the addition of a small amount of aromatic dicarboxylic acid has little negative impact on the mechanical properties. The reasons may be: (1) Nylon resin will contain a certain amount of oligomers (the content is generally 0.5-2.5%, mass content), too many oligomers, easy to appear wool during spinning, not only affect the nylon composite The mechanical properties of the material also affect the flame-retardant stability of V-2; (2) The aromatic dicarboxylic acid has a high melting point, which is relatively stable in the processing temperature range of nylon and is difficult to attack the amide bond, which has a negative impact on the mechanical properties Small; at the same time, during the combustion (600-700°C), the aromatic dicarboxylic acid decomposes and attacks the amide bond, and produces a dripping effect, which takes away a large amount of heat and prevents combustion, making the flame retardant stability better.

That is to say, the present invention not only achieves a stable flame-retardant V-2 grade by selecting nylon resin with a lower oligomer content, but also adds a small amount of aromatic dicarboxylic acid to carry out flame-retardant modification, and is effective for flame-retardant nylon The mechanical properties of the composites were not negatively affected.

Preferably, the weight portion of the aromatic dicarboxylic acid in the flame-retardant nylon composite material is 0.1-1 part.

Common nylon materials in the art can be used in the present invention.

Preferably, the nylon resin is one or more of PA6, PA66 or PA66/6.

Preferably, the oligomer content in the nylon resin is 1.0-1.6%.

Preferably, the number average molecular weight of the oligomer is not higher than 1000.

Preferably, the aromatic dicarboxylic acid is one or more of naphthalene dicarboxylic acid or phthalic acid.

More preferably, the naphthalene dicarboxylic acid is one or more of 1,4-naphthalene dicarboxylic acid or 2,6-naphthalene dicarboxylic acid.

More preferably, the phthalic acid is one or more of terephthalic acid, isophthalic acid or phthalic acid.

More preferably, the aromatic dicarboxylic acid is one or both of naphthalene dioic acid (1,4-naphthalene dioic acid) or terephthalic acid.

Preferably, the flame-retardant nylon composite material also includes other processing aids.

More preferably, the other processing aids are one or more of antioxidants, lubricants, nucleating agents or antistatic agents.

Preferably, the antioxidant is one of hindered phenol antioxidants, copper salt antioxidants, aromatic amine antioxidants, phosphite antioxidants or thioester antioxidants or Several kinds.

Preferably, the weight part of the antioxidant is 0.05-1 part.

More preferably, the hindered phenolic antioxidant is N, N'-hexamethylene bis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide (Irganox 1098), tetrakis[1093,5 -Di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol (Irganox 1010), triethylene glycol bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate (Iragnox 259), n-octadecyl β-(4-hydroxy-3,5-di-tert-butylphenyl)propionate (Iragno 1076) or spiroethylene glycol bis[β-(3-tert-butyl-4 -Hydroxy-5-methylphenyl) propionate] (ADK AO-80) in one or more.

More preferably, the copper salt antioxidant is cuprous iodide.

More preferably, the aromatic amine antioxidant is one of 4,4'-bis(α(α(-dimethylbenzyl)diphenylamine (Naugard 445) or polyamine mixture (Flexamine Granular) or two.

More preferably, the phosphite antioxidant is 2,4-di-tert-butylphenol (Irganox 168), two (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol phosphite ( One or both of ADK PEP-36).

More preferably, the mercaptan antioxidant is bis(octadecyl)thiodipropionate (Irganox PS802) pentaerythritol tetrakis(3-lauryl thiopropionate) (THANOX 412S).

Preferably, the lubricant is one or more of amide lubricants, ester lubricants or fatty acid salt lubricants.

Preferably, the weight part of the lubricant is 0.2-1.5 parts.

More preferably, the amide lubricant is one or both of ethylene bis stearamide (EBS) or ethylene bis (12 hydroxymethyl) stearamide (TAF).

More preferably, the ester lubricant is pentaerythritol tetrastearate (PETS).

More preferably, the fatty acid salt lubricant is one or more of zinc stearate, calcium stearate or calcium montanate.

Further preferably, the nucleating agent is one or more of amide nucleating agents, silicate nucleating agents or phosphate nucleating agents.

Preferably, the weight part of the nucleating agent is 0.1-0.5 parts.

More preferably, the amide nucleating agent is polyethylenediamine oxalic acid, polydecanediamine terephthalic acid, polydecanediamine isophthalic acid, polynonanediamine terephthalic acid or polynonanediamine terephthalic acid. One or more of diamine isophthalic acid.

Even more preferably, the silicate nucleating agent is one or more of talc, kaolin or hydrotalcite.

More preferably, the phosphate nucleating agent is sodium phenylphosphinate, sodium phenylphosphite, 2,2'-methylene-di(4,6-di-tert-butylphenyl)sodium phosphate Or one or more of bis[2,2'-methylene-bis(4,6-di-tert-butylphenyl)]aluminum phosphate.

Preferably, the antistatic agent is one or more of polyethylene glycols.

Preferably, the weight part of the antistatic agent is preferably 10-30 parts.

Further preferably, the weight part of the antistatic agent is preferably 15-25 parts.

The preparation method of the above-mentioned flame-retardant nylon composite material includes the following steps: uniformly mixing each component to obtain a mixture, then melting and extruding the mixture, and granulating to obtain the flame-retardant nylon composite material.

Preferably, the preparation method of the flame-retardant nylon composite material includes the following steps: mixing each component uniformly in a high-speed mixer to obtain a compound, then adding the compound to a twin-screw extruder for melt extrusion, and granulating , to obtain the flame-retardant nylon composite material; wherein, the screw length-to-diameter ratio of the twin-screw extruder is 40-48:1, the temperature of the screw barrel is 250-320° C., and the screw speed is 200-550 rpm.

The application of the above-mentioned flame-retardant nylon composite material in the preparation of electronic appliances (such as connectors, switch panels) is also within the protection scope of the present invention.

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

The flame-retardant nylon composite material provided by the present invention uses a specific nylon resin as the base material, and at the same time adds a small amount of aromatic dicarboxylic acid for flame-retardant modification. The mechanical properties of the nylon composites were not negatively affected.

Detailed ways

The present invention is further set forth below in conjunction with embodiment. These examples are only for illustrating the present invention and are not intended to limit the scope of the present invention. The experimental method that does not indicate specific conditions in the following example embodiment, usually according to the conventional conditions in this field or according to the conditions suggested by the manufacturer; used raw materials, reagents, etc., if no special instructions, are available from commercial channels such as conventional markets Raw materials and reagents obtained. Any insubstantial changes and substitutions made by those skilled in the art on the basis of the present invention all belong to the scope of protection claimed by the present invention.

The partial reagents that each embodiment of the present invention and comparative examples select are described as follows:

Nylon material 1#, 50BWFS, PA66, ASCEND company, the content of oligomers with number average molecular weight less than 1000 is 1%;

Nylon material 2#, 88X, PA66/6, ASCEND company, the content of the oligomer whose number average molecular weight is lower than 1000 is 1.6%;

Nylon material 3#, M2400, PA66, Xinhui Meida Chemical Co., Ltd., the content of oligomers with a number average molecular weight lower than 1000 is 1.3%;

Nylon material 4#, EP-158, PA66, Huafeng Group Co., Ltd., the content of oligomers with a number average molecular weight lower than 1000 is 2.6%;

Aromatic dicarboxylic acid 1#: 1,4-naphthalene dicarboxylic acid, chemically pure, Aladdin;

Aromatic dicarboxylic acid 2#: isophthalic acid, chemically pure, Aladdin;

Aromatic dicarboxylic acid 3#: phthalic acid, chemically pure, Aladdin;

Aromatic monocarboxylic acids: benzoic acid, chemically pure, Aladdin;

Long carbon chain dibasic saturated carboxylic acid: sebacic acid, chemically pure, Aladdin;

Melamine cyanurate: melamine cyanurate, commercially available;

Other processing aids: antistatic agent, polyethylene glycol, 3600, commercially available.

It should be understood that, if not specified otherwise, a certain component (such as aromatic dicarboxylic acid 1～3#, melamine cyanurate, antioxidant, lubricant, nucleating agent) included in the examples or comparative examples agent, antistatic agent) are the same commercially available products.

The preparation method of the nylon composite material of each embodiment and comparative example of the present invention is: take each raw material according to the proportion, premix in a high mixer to obtain a premix; then put the premix into a twin-screw extruder Melt and mix, and extrude and granulate to obtain a nylon composite material; wherein, the aspect ratio of the twin-screw extruder is 36:1; the temperature of the screw barrel is set as 250-260-270-280 -290-290-290-300-320°C; the screw speed is 350 rpm.

Each embodiment of the present invention and the nylon composite material of comparative example carry out following test:

(1) Flame retardant performance test: clamp the sample strip 6mm from the upper end, the length direction is downward, and the lower end of the sample is kept at a distance of 300±10mm from the surface of the prefabricated cotton layer. The thickness of the cotton is not more than 6mm, the size is 50mm×50mm, and the weight About 0.08g. The burning appliance adopts the methane flow rate of 105ml/min, the pressure is 0.1kpa, and the flame height is 20±1mm. The center of the flame is placed at the midpoint of the lower edge of the sample. The distance from the top of the burning appliance to the lower end of the sample is 10±1mm, and it is maintained for 10±0.5 seconds. If there is a change in shape and position during the combustion process, the burning appliance needs to be adjusted. When the molten material drips, tilt the burner to 45°, move the burner away at a speed of 300mm/min for at least 150mm after burning for 10±0.05 seconds, and start recording the afterflame time t1 at the same time, and burn again immediately after the afterflame stops. 0.5 seconds, record afterflame time t2 after removing. Before the test, the following pretreatments were carried out: 48 hours at 23°C and 50% RH; 5 samples were tested for each group of samples;

(2) Flame retardant stability test: The prepared sample was treated at 70° C. for 168 hours, then at 23° C. and 50% humidity for 48 hours, and then tested for UL94 flame retardancy.

(3) Elongation at break test: perform a tensile test on the injection molded strip according to the ISO527 standard at a tensile speed of 50 mm/min, and record the elongation at break.

Examples 1-10

This example provides a series of flame-retardant nylon composite materials, and the dosage of each component in the formula is shown in Table 1.

The formula (part) of table 1 embodiment 1～10

Comparative example 1～7

This comparative example provides a series of nylon composite materials, and the dosage of each component in the formula is shown in Table 2.

The test results of the nylon composite materials provided in each embodiment and comparative example are shown in Table 3.

The performance test result of the nylon composite material that table 3 embodiment and comparative example provide

From the above test results, it can be seen that the flame-retardant nylon composite materials provided by each example can reach the flame-retardant V-2 grade, and after being treated at 70°C for 168 hours, it can still maintain the flame-retardant V-2 grade, and has excellent flame-retardant stability; In addition, there is basically no negative effect on the mechanical properties. In Comparative Example 1, no flame retardant modification was performed, and the flame retardant grade was gradeless; in Comparative Example 2, a small amount of melamine cyanurate was added as a flame retardant, and the flame retardancy was gradeless, and the elongation at break decreased significantly; Comparative Example 3 A relatively large amount of melamine cyanurate was added as a flame retardant, although the flame retardant grade can reach the V-0 grade, but the flame retardant stability is not good, and the elongation at break is significantly reduced; in comparative example 4, aromatic monoaryl Carboxylic acid is modified, although the flame retardant grade can reach V-2, but the flame retardant stability is not good, and the mechanical properties decline more seriously; comparative example 5 is modified by adding a small amount of long carbon chain dibasic saturated carboxylic acid, Although the flame retardant grade can reach V-2, the flame retardant stability is poor, the mechanical properties are poor, and the elongation at break drops significantly; comparative example 6 is modified by adding a large amount of long carbon chain dibasic saturated carboxylic acid, but the flame retardant The flame stability is also not good, the mechanical properties are poor, and the elongation at break is significantly obvious; Comparative Example 7 selects the nylon material with higher oligomer content, the mechanical properties are not good, the elongation at break is low, and the flame retardant stability is not good.

Those skilled in the art will appreciate that the embodiments herein are to help readers understand the principles of the present invention, and it should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical revelations disclosed in the present invention without departing from the essence of the present invention, and these modifications and combinations are still within the protection scope of the present invention.

Claims (10)

A flame-retardant nylon composite material is characterized in that it comprises the following components in parts by weight: Nylon resin 97～99.95 parts; Aromatic dicarboxylic acid 0.05-2 parts; The oligomer content in the nylon resin is not higher than 1.6%. The flame-retardant nylon composite material according to claim 1, characterized in that, the weight portion of the aromatic dicarboxylic acid in the flame-retardant nylon composite material is 0.1-1 part. The flame-retardant nylon composite material according to claim 1, wherein the nylon resin is one or more of PA6, PA66 or PA66/6. The flame-retardant nylon composite material according to claim 1, characterized in that the oligomer content in the nylon resin is 1.0-1.6%. The flame-retardant nylon composite material according to claim 1, wherein the aromatic dicarboxylic acid is one or more of naphthalene dicarboxylic acid or phthalic acid. According to the described flame retardant nylon composite material of claim 5, it is characterized in that, described naphthalene dicarboxylic acid is one or both in 1,4-naphthalene dicarboxylic acid or 2,6-naphthalene dicarboxylic acid; One or more of terephthalic acid, isophthalic acid or phthalic acid. The flame-retardant nylon composite material according to claim 1, wherein the number average molecular weight of the oligomer is not higher than 1000. The flame retardant nylon composite material according to claim 1, characterized in that the flame retardant nylon composite material further comprises other processing aids. The preparation method of the flame-retardant nylon composite material according to any one of claims 1-8, characterized in that it comprises the following steps: uniformly mixing each component to obtain a mixture, then melting and extruding the mixture, and granulating to obtain the obtained Said flame retardant nylon composite material. The use of the flame-retardant nylon composite material in any one of claims 1-8 in the preparation of electronic appliances.