Halogen-free flame-retardant non-reinforced nylon material and preparation method thereof

Abstract

The invention provides a halogen-free flame-retardant non-reinforced nylon material and a preparation method thereof, and the halogen-free flame-retardant non-reinforced nylon material comprises the following components in percentage by mass: 78-82% of nylon 6I / 6T resin and 18-22% of a flame retardant, the preparation method comprises the following steps: weighing the nylon 6I / 6T resin and the flame retardant according to a formula ratio; uniformly mixing the weighed nylon 6I / 6T resin and flame retardant in a high-speed mixer to obtain a mixture; and putting the mixture into a double-screw extruder for extrusion and granulation to obtain the halogen-free flame-retardant non-reinforced nylon material. The novel flame retardant and the aromatic nylon material are compounded and modified, so that the modified nylon material can keep good impact resistance, and meanwhile, the nylon material can be ensured to have excellent flame retardance.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a halogen-free flame-retardant non-reinforced nylon and a preparation method thereof. Background Art

[0002] Polyamide, commonly known as nylon, is widely used in machinery manufacturing, electronic appliances, transportation and other fields due to its excellent mechanical properties and mature processing technology. Polyamide has a melting drop phenomenon during the combustion process, which plays a flame retardant role to a certain extent, but there is a risk of spreading fire. Therefore, when polyamide is used to prevent open flames, heat sources, electrical short circuits, electrical breakdown and other occasions, flame retardants need to be added to the components to make its flame retardancy and comprehensive performance meet the requirements.

[0003] At present, the flame retardants commonly used in polyamides mainly include halogen-containing flame retardants, phosphorus-based flame retardants, intumescent flame retardants and inorganic hydroxide flame retardants. Among them, phosphorus-based flame retardants have the advantages of low corrosiveness and less toxic gases, which is in line with the current development direction of flame retardants with high performance, low smoke and low toxicity.

[0004] The ratio of flame retardants and the dispersion of flame retardants in the nylon matrix are the direct reasons that affect the flame retardant effect of the material. In addition, the addition of flame retardants will lead to a decrease in the mechanical properties of nylon materials, such as impact strength and bending strength. At present, while meeting the flame retardant properties of products, various engineering plastics have increasingly higher requirements for mechanical properties. Therefore, it is necessary to modify the existing nylon materials to meet the flame retardant properties and have good mechanical properties. Summary of the invention

[0005] The present invention aims to provide a halogen-free flame-retardant non-reinforced nylon material and a preparation method thereof. The obtained nylon material has not only excellent flame-retardant properties but also good impact resistance.

[0006] To achieve the above object, the present invention proposes the following technical solutions:

[0007] A halogen-free flame-retardant non-reinforced nylon material, comprising the following components by mass percentage:

[0008] Nylon 6I / 6T resin 78%-82%, flame retardant 18%-22%.

[0009] As a preferred technical solution of the present invention, the viscosity of the nylon 6I / 6T resin is 2.4-2.8.

[0010] As a preferred technical solution of the present invention, the flame retardant is diisobutyl aluminum hypophosphite.

[0011] A method for preparing a halogen-free flame-retardant non-reinforced nylon material comprises the following steps:

[0012] Step 1: weighing the nylon 6I / 6T resin and the flame retardant according to the formula ratio;

[0013] Step 2: placing the nylon 6I / 6T resin and the flame retardant weighed in the step 1 in a high-speed mixer and mixing them evenly to obtain a mixture;

[0014] Step three: placing the mixed material in a twin-screw extruder for extrusion and granulation to obtain the halogen-free flame-retardant non-reinforced nylon material.

[0015] As a preferred technical solution of the present invention, the screw length-to-diameter ratio of the twin-screw extruder in step three is 32:1 or 24:1.

[0016] As a preferred technical solution of the present invention, the extrusion temperature of the twin-screw extruder in step three is 220° C.-290° C., and the screw speed is 200-500 rpm.

[0017] As a preferred technical solution of the present invention, the halogen-free flame-retardant non-reinforced nylon material is used to prepare flame-retardant products in the fields of automobiles, machinery and chemical industry.

[0018] The technical scheme of the present invention provides a halogen-free flame-retardant non-reinforced nylon material and a preparation method thereof. By using diisobutyl aluminum hypophosphite and nylon 6I / 6T resin for compounding and modification, the problem of flame retardant dispersion in the preparation process can be effectively solved, thereby meeting the flame retardant performance requirements and ensuring that the nylon material has excellent impact resistance. The molecular structure and mechanical properties of nylon 6I / 6T have certain similarities with nylon 6, but due to the different molecular structures of the two, there are still substantial differences between nylon 6I / 6T and nylon 6. The molecular structure of nylon 6I / 6T introduces an aromatic ring structure, and the benzene ring and amide bond in the aromatic ring structure are arranged alternately. The benzene ring itself has rigidity and has a conjugated effect with the amide group, and the hydrogen on the amide group can combine with the oxygen on the carbonyl group of another molecular amide group to form a hydrogen bond. The formation of hydrogen bonds makes the structure of polyamide easy to crystallize, and the hydrogen bond force between molecules is large, so that the heat resistance and other properties of the nylon material are significantly improved. At the same time, the melting point of diisobutyl aluminum hypophosphite is around 250℃-275℃, and it is easier to mix evenly with nylon 6I / 6T resin during processing, so the combination of the two can effectively improve the flame retardant properties of the material while ensuring its excellent impact resistance.

[0019] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, may be considered to be part of the inventive subject matter of the present disclosure, provided such concepts are not mutually inconsistent. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs.

[0021] The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular form of "a", "an" or "the" and similar words do not indicate a quantitative limitation, but indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" include the features, wholes, steps, operations, elements and / or components listed after "include" or "comprise", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] The sources of the main raw materials in the following embodiments and comparative examples of the present invention are as follows:

[0023] Nylon 6I / 6T resin: relative viscosity 2.7, purchased from Shandong Guangyin New Materials Co., Ltd.;

[0024] Flame retardant (diisobutyl aluminum hypophosphite): brand D-13, purchased from Hebei Xinxinyuan Energy Co., Ltd.;

[0025] The testing standards used in the performance testing of the corresponding products in the embodiments and comparative examples of the present invention are as follows:

[0026] The testing standard for flexural strength and flexural modulus is: ASTM790.

[0027] The testing standard for simply supported beam unnotched impact strength is: ASTM256.

[0028] The testing standard for flame retardancy is UL94.

[0029] Example 1

[0030] A method for preparing a halogen-free flame-retardant non-reinforced nylon material comprises the following steps:

[0031] Step 1: Weigh each component according to the following weight percentage:

[0032] Nylon 6I / 6T resin is 82%, and flame retardant diisobutyl aluminum hypophosphite is 18%;

[0033] Step 2: Put the nylon 6I / 6T resin and diisobutyl aluminum hypophosphite weighed in step 1 into a high-speed mixer, and mix them evenly at 23° C. to obtain a mixture;

[0034] Step 3: Put the mixed material into a twin-screw extruder for extrusion and granulation to obtain the halogen-free flame-retardant non-reinforced nylon material 1.

[0035] Wherein, in the step 3, the screw aspect ratio selected for the twin-screw extruder is 32:1; the extrusion temperature of the twin-screw extruder is set to 150°C in zone 1, 230°C in zone 2, 250°C in zone 3, 250°C in zone 4, 250°C in zone 5, 250°C in zone 6, 240°C in zone 7, 240°C in zone 8, 230°C in zone 9, 230°C in zone 10, 250°C in zone 11, and 250°C in zone 12, and the die temperature is 250°C; the screw speed is 350 rpm.

[0036] Example 2

[0037] A method for preparing a halogen-free flame-retardant non-reinforced nylon material comprises the following steps:

[0038] Step 1: Weigh each component according to the following weight percentage:

[0039] Nylon 6I / 6T resin is 78%, and flame retardant diisobutyl aluminum hypophosphite is 22%;

[0040] Step 2: Put the nylon 6I / 6T resin and diisobutyl aluminum hypophosphite weighed in step 1 into a high-speed mixer, and mix them evenly at 23° C. to obtain a mixture;

[0041] Step 3: Put the mixed material into a twin-screw extruder for extrusion and granulation to obtain the halogen-free flame-retardant non-reinforced nylon material 2.

[0042] Wherein, in the step 3, the screw aspect ratio selected for the twin-screw extruder is 32:1; the extrusion temperature of the twin-screw extruder is set to 150°C in zone 1, 230°C in zone 2, 250°C in zone 3, 250°C in zone 4, 250°C in zone 5, 250°C in zone 6, 240°C in zone 7, 240°C in zone 8, 230°C in zone 9, 230°C in zone 10, 250°C in zone 11, and 250°C in zone 12, and the die temperature is 250°C; the screw speed is 350 rpm.

[0043] Comparative Example 1

[0044] A method for preparing a nylon material comprises the following steps:

[0045] Step 1, weigh an appropriate amount of nylon 6I / 6T resin (100%);

[0046] Step 2: Place the nylon 6I / 6T resin weighed in step 1 into a twin-screw extruder for extrusion granulation to obtain nylon material 1.

[0047] Among them, the screw aspect ratio selected for the twin-screw extruder is 32:1, the extrusion temperature of the twin-screw extruder is set to 150°C in zone 1, 230°C in zone 2, 250°C in zone 3, 250°C in zone 4, 250°C in zone 5, 250°C in zone 6, 240°C in zone 7, 240°C in zone 8, 230°C in zone 9, 230°C in zone 10, 250°C in zone 11, and 250°C in zone 12, the die temperature is 250°C, and the screw speed is 350 rpm.

[0048] Comparative Example 2

[0049] A method for preparing a nylon material comprises the following steps:

[0050] Step 1: Weigh each component according to the following weight percentage:

[0051] Nylon 6 is 82%, diisobutyl aluminum hypophosphite is 18%;

[0052] Step 2, putting the nylon 6 and diisobutyl aluminum hypophosphite weighed in step 1 into a high-speed mixer, and mixing them uniformly at 23° C. to obtain a mixture;

[0053] Step 3: Put the mixed material into a twin-screw extruder for extrusion and granulation to obtain nylon material 2.

[0054] Wherein, in the step 3, the screw aspect ratio selected for the twin-screw extruder is 32:1, and the extrusion temperature of the twin-screw extruder is set to 150°C in zone 1, 230°C in zone 2, 250°C in zone 3, 250°C in zone 4, 250°C in zone 5, 250°C in zone 6, 240°C in zone 7, 240°C in zone 8, 230°C in zone 9, 230°C in zone 10, 250°C in zone 11, and 250°C in zone 12, the die temperature is 250°C, and the screw speed is 350 rpm.

[0055] Comparative Example 3

[0056] A method for preparing a nylon material comprises the following steps:

[0057] Step 1: Weigh an appropriate amount of nylon 6 (100%);

[0058] Step 2: Put the nylon 6 weighed in step 1 into a twin-screw extruder for extrusion and granulation to obtain nylon material 3.

[0059] Among them, the screw aspect ratio selected for the twin-screw extruder is 32:1, the extrusion temperature of the twin-screw extruder is set to 150°C in zone 1, 230°C in zone 2, 250°C in zone 3, 250°C in zone 4, 250°C in zone 5, 250°C in zone 6, 240°C in zone 7, 240°C in zone 8, 230°C in zone 9, 230°C in zone 10, 250°C in zone 11, and 250°C in zone 12, the die temperature is 250°C, and the screw speed is 350 rpm.

[0060] Comparative Example 4

[0061] A method for preparing a nylon material comprises the following steps:

[0062] Step 1: Weigh each component according to the following weight percentage:

[0063] Nylon 56 is 82%, flame retardant is 18%;

[0064] Step 2, putting the nylon 56 and flame retardant diisobutyl aluminum hypophosphite weighed in step 1 into a high-speed mixer, and mixing them evenly at 23° C. to obtain a mixture;

[0065] Step 3: Put the mixed material into a twin-screw extruder for extrusion and granulation to obtain nylon material 4.

[0066] Wherein, in the step 3, the screw aspect ratio selected for the twin-screw extruder is 32:1, and the extrusion temperature of the twin-screw extruder is set to 150°C in zone 1, 230°C in zone 2, 260°C in zone 3, 260°C in zone 4, 260°C in zone 5, 260°C in zone 6, 250°C in zone 7, 250°C in zone 8, 240°C in zone 9, 240°C in zone 10, 250°C in zone 11, and 260°C in zone 12, the die temperature is 260°C, and the screw speed is 350 rpm.

[0067] Comparative Example 5

[0068] A method for preparing a nylon material comprises the following steps:

[0069] Step 1, weigh an appropriate amount of nylon 56 (100%);

[0070] Step 2: Put the nylon 56 weighed in step 1 into a twin-screw extruder for extrusion and granulation to obtain nylon material 5.

[0071] Among them, the screw aspect ratio selected for the twin-screw extruder is 32:1, the extrusion temperature of the twin-screw extruder is set to 150°C in zone 1, 230°C in zone 2, 260°C in zone 3, 260°C in zone 4, 260°C in zone 5, 260°C in zone 6, 250°C in zone 7, 250°C in zone 8, 240°C in zone 9, 240°C in zone 10, 250°C in zone 11, and 260°C in zone 12, the die temperature is 260°C, and the screw speed is 350 rpm.

[0072] Comparative Example 6

[0073] A method for preparing a nylon material comprises the following steps:

[0074] Step 1: Weigh each component according to the following weight percentage:

[0075] Nylon 66 is 82%, flame retardant is 18%;

[0076] Step 2, putting the nylon 66 and flame retardant diisobutyl aluminum hypophosphite weighed in step 1 into a high-speed mixer, and mixing them evenly at 23° C. to obtain a mixture;

[0077] Step 3: Put the mixed material into a twin-screw extruder for extrusion and granulation to obtain nylon material 6.

[0078] Wherein, in the step 3, the screw aspect ratio selected for the twin-screw extruder is 32:1, and the extrusion temperature of the twin-screw extruder is set to 150°C in zone 1, 230°C in zone 2, 260°C in zone 3, 260°C in zone 4, 260°C in zone 5, 260°C in zone 6, 250°C in zone 7, 250°C in zone 8, 240°C in zone 9, 240°C in zone 10, 250°C in zone 11, and 260°C in zone 12, the die temperature is 260°C, and the screw speed is 350 rpm.

[0079] Comparative Example 7

[0080] A method for preparing a nylon material comprises the following steps:

[0081] Step 1, weigh an appropriate amount of nylon 66 (100%);

[0082] Step 2: Place the nylon 66 weighed in step 1 into a twin-screw extruder for extrusion granulation to obtain nylon material 7.

[0083] Among them, the screw aspect ratio selected for the twin-screw extruder is 32:1, the extrusion temperature of the twin-screw extruder is set to 150°C in zone 1, 230°C in zone 2, 260°C in zone 3, 260°C in zone 4, 260°C in zone 5, 260°C in zone 6, 250°C in zone 7, 250°C in zone 8, 240°C in zone 9, 240°C in zone 10, 250°C in zone 11, and 260°C in zone 12, the die temperature is 260°C, and the screw speed is 350 rpm.

[0084] For the convenience of comparison, the composition ratios of the above embodiments and comparative examples are summarized in the following Table 1:

[0085] Table 1 Formula ratio of each embodiment and comparative example

[0086]

[0087]

[0088] Performance testing

[0089] In order to verify the mechanical properties and flame retardant properties of the nylon materials obtained in the above embodiments and comparative examples, the nylon materials obtained in the above embodiments and comparative examples are tested for bending strength, bending modulus, simply supported beam unnotched impact strength and UL94 (0.8 mm and 1.6 mm) flame retardant properties. The test results are shown in Table 2 below:

[0090] Table 2 Performance test results of the material products obtained in each embodiment and comparative example

[0091]

[0092] It can be seen from the test data of Examples 1 and 2 and Comparative Examples 1-7 in the above table that the flame-retardant non-reinforced nylon material prepared by the method of the present invention can obtain excellent flame retardant properties and still has good impact resistance compared with other comparative examples. The details are as follows:

[0093] From the test data of Comparative Examples 1, 3, 5 and 7, it can be seen that without adding flame retardants, the flame retardancy of PA6I / 6T and PA56 is only V-2 (0.8mm), which is poor, while PA6 and PA66 do not reach the flame retardancy level specified by UL94.

[0094] It can be seen from the test data of Example 1 and Comparative Example 1 that adding the flame retardant diisobutyl aluminum hypophosphite can significantly improve the flame retardant properties of the material, so that the flame retardant properties of the material are improved from V-2 (0.8 mm) to V-0 (0.8 mm).

[0095] It can be seen from the test data of Example 1 and Comparative Examples 2 and 4 that when nylon resin is modified by diisobutyl aluminum hypophosphite, compared with other resins, the flame retardant properties of the material can be significantly improved by compounding PA6I / 6T with diisobutyl aluminum hypophosphite, so that the flame retardant properties of the material are directly improved from V-2 to V-0. At the same time, the material still has good impact resistance.

[0096] It can be seen from the test data of Example 1 and Comparative Example 6 that when the resin is modified by diisobutyl aluminum hypophosphite, the flame retardant properties of PA66 and PA6I / 6T can reach V-0 (0.8mm). However, the compounding of PA6I / 6T and diisobutyl aluminum hypophosphite still has good impact resistance.

[0097] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A halogen-free flame-retardant non-reinforced nylon material, characterized in that: According to mass percentage, it includes the following components: Nylon 6I / 6T resin 78%-82%, flame retardant 18%-22%.

2. The halogen-free flame-retardant non-reinforced nylon material according to claim 1, characterized in that: The viscosity of the nylon 6I / 6T resin is 2.4-2.

8.

3. The halogen-free flame-retardant non-reinforced nylon material according to claim 1, characterized in that: The flame retardant is diisobutyl aluminum hypophosphite.

4. A method for preparing a halogen-free flame-retardant non-reinforced nylon material as claimed in any one of claims 1 to 3, characterized in that: The steps include: Step 1: weighing the nylon 6I / 6T resin and the flame retardant according to the formula ratio; Step 2: placing the nylon 6I / 6T resin and the flame retardant weighed in the step 1 in a high-speed mixer and mixing them evenly to obtain a mixture; Step three: placing the mixed material in a twin-screw extruder for extrusion and granulation to obtain the halogen-free flame-retardant non-reinforced nylon material.

5. The method for preparing the halogen-free flame-retardant non-reinforced nylon material according to claim 4, characterized in that: The screw length-to-diameter ratio of the twin-screw extruder in step three is 32:1 or 24:

1.

6. The method for preparing the halogen-free flame-retardant non-reinforced nylon material according to claim 4, characterized in that: The extrusion temperature of the twin-screw extruder in step three is 220° C.-290° C., and the screw speed is 200-500 rpm.

7. The use of the halogen-free flame-retardant non-reinforced nylon material according to any one of claims 1 to 3, characterized in that: The halogen-free flame-retardant non-reinforced nylon material is used for preparing flame-retardant products in the fields of automobiles, machinery and chemicals.

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