Flame-retardant polyamide composition and preparation method thereof
阅读说明：本技术 阻燃聚酰胺组合物及其制备方法 (Flame-retardant polyamide composition and preparation method thereof ) 是由 潘凯 陈向阳 黄国桃 于 2019-10-28 设计创作，主要内容包括：本发明公开了一种阻燃聚酰胺组合物及其制备方法。本发明的阻燃聚酰胺组合物由包括己内酰胺、开环剂、抗氧剂和阻燃剂的原料反应得到。本发明的阻燃聚酰胺组合物阻燃性能好,且具有抗熔滴性。(The invention discloses a flame-retardant polyamide composition and a preparation method thereof. The flame-retardant polyamide composition is obtained by reacting raw materials comprising caprolactam, a ring-opening agent, an antioxidant and a flame retardant. The flame-retardant polyamide composition has good flame retardant property and melt-drip resistance.)
1. The flame-retardant polyamide composition is characterized by being obtained by reacting raw materials comprising caprolactam, a ring-opening agent, an antioxidant and a flame retardant;
wherein the flame retardant has a structure represented by formula (I):
R1is selected from alkyl of C1-C5, cycloalkyl of C3-C6 and aryl of C6-C10; r2、R3Are each independently selected from- (CH)2)x-NH2And- (CH)2)y-COOH, x and y are each independently selected from integers of 0 to 3; r4Selected from hydrogen atoms and alkyl groups of C1-C4; n is selected from 2An integer of 4.
2. Flame retardant polyamide composition according to claim 1, characterized in that R is1Selected from C2-C4 alkyl and C6-C8 aryl; r2、R3Are each independently selected from-NH2、-COOH；R4Selected from hydrogen atoms and alkyl groups of C1-C2; n is 2.
3. Flame retardant polyamide composition according to claim 1, characterized in that R is1Is phenyl, R2And R3Are each independently selected from-NH2、-COOH；R4Is a hydrogen atom; n is 2.
4. The flame retardant polyamide composition according to claim 1, wherein the flame retardant is a compound a represented by the following formula:
5. the flame-retardant polyamide composition according to claim 1, wherein the raw materials comprise 100 parts by weight of caprolactam, 0.1-15 parts by weight of a ring-opener, 0.1-5 parts by weight of an antioxidant and 0.1-15 parts by weight of a flame retardant.
6. The flame retardant polyamide composition of claim 1 wherein the ring opener is selected from at least one of water, aminocaproic acid; the antioxidant is at least one selected from antioxidant 1010 and antioxidant 168.
7. Process for the preparation of a flame retardant polyamide composition according to any of claims 1 to 6, characterized in that it comprises the following steps:
(1) reacting caprolactam, a ring-opening agent and an antioxidant to obtain a reaction product;
(2) adding a flame retardant into the reaction product, and continuously reacting to obtain the flame-retardant polyamide composition.
8. The method according to claim 7, wherein in the step (1), the caprolactam, the ring-opener and the antioxidant are reacted at a low temperature under an inert atmosphere and then at a high temperature; wherein the temperature of the low-temperature reaction is 60-100 ℃, the pressure of the low-temperature reaction is 0.1-0.4 MPa, the time of the low-temperature reaction is 0.3-2 h, the temperature of the high-temperature reaction is 200-250 ℃, the pressure of the high-temperature reaction is 1.5-3.0 MPa, and the time of the high-temperature reaction is 1-3 h.
9. The preparation method according to claim 7, wherein in the step (2), the flame retardant is added to the reaction product, and the high-pressure reaction is carried out first, and then the vacuum reaction is carried out; wherein the temperature of the high-pressure reaction is 220-280 ℃, the pressure of the high-pressure reaction is 2.5-5 MPa, the time of the high-pressure reaction is 1-3 h, the temperature of the vacuum reaction is 230-290 ℃, the pressure of the vacuum reaction is-1.1-0.6 MPa, and the time of the vacuum reaction is 2-6 h.
10. The method according to claim 9, wherein the high pressure reaction and the vacuum reaction are carried out under stirring in step (2) at a speed of 150 to 300 rpm.
Technical Field
The invention relates to a flame-retardant polyamide composition and a preparation method thereof, in particular to an anti-dripping flame-retardant polyamide composition and a preparation method thereof.
Background
The polyamide is also called nylon, has excellent performances such as high strength, high wear resistance and the like, and is widely applied to the fields of buildings, textiles, military affairs and the like. However, polyamides are extremely flammable and, at present, the polyamide matrix is usually modified by blending with flame retardants to increase the flame retardant properties of the polyamides. The blending modification method needs to use a large amount of flame retardant, the dispersibility of the flame retardant in the polyamide matrix is poor, and the mechanical property of the modified polyamide is greatly reduced; the modified polyamide will show the phenomenon of flame retardant migration after long-term use, so that the flame retardant performance is reduced.
Compared with the traditional flame retardant, the Intumescent Flame Retardant (IFR) has the advantages of high efficiency, no halogen and environmental protection. However, the common intumescent flame retardant can not bear high temperature, so that the reports of modifying polyamide by adopting the intumescent flame retardant through a copolymerization modification method are rare.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a flame retardant polyamide composition having good flame retardant properties and anti-dripping properties.
The invention also aims to provide a preparation method for preparing the flame-retardant polyamide composition, which can prepare the flame-retardant polyamide composition with good flame-retardant property and anti-dripping property. The technical scheme is adopted to achieve the purpose.
In one aspect, the invention provides a flame retardant polyamide composition obtained by reacting raw materials comprising caprolactam, a ring-opening agent, an antioxidant and a flame retardant;
wherein the flame retardant has a structure represented by formula (I):
R1is selected from alkyl of C1-C5, cycloalkyl of C3-C6 and aryl of C6-C10; r2、R3Are each independently selected from- (CH)2)x-NH2And- (CH)2)y-COOH, x and y are each independently selected from integers of 0 to 3; r4Selected from hydrogen atoms and alkyl groups of C1-C4; n is an integer of 2 to 4.
According to the flame retardant polyamide composition of the invention, preferably R1Selected from C2-C4 alkyl and C6-C8 aryl; r2、R3Are each independently selected from-NH2、-COOH；R4Selected from hydrogen atoms and alkyl groups of C1-C2; n is 2.
According to the flame retardant polyamide composition of the invention, preferably R1Is phenyl, R2And R3Are each independently selected from-NH2、-COOH；R4Is a hydrogen atom; n is 2.
According to the flame retardant polyamide composition of the present invention, preferably, the flame retardant is a compound a represented by the following formula:
according to the flame-retardant polyamide composition, the raw materials preferably comprise 100 parts by weight of caprolactam, 0.1-15 parts by weight of ring-opening agent, 0.1-5 parts by weight of antioxidant and 0.1-15 parts by weight of flame retardant.
The flame retardant polyamide composition according to the present invention, preferably, the ring-opener is selected from at least one of water, aminocaproic acid; the antioxidant is at least one selected from antioxidant 1010 and antioxidant 168.
In another aspect, the present invention also provides a method for preparing the flame retardant polyamide composition, comprising the steps of:
(1) reacting caprolactam, a ring-opening agent and an antioxidant to obtain a reaction product;
(2) adding a flame retardant into the reaction product, and continuously reacting to obtain the flame-retardant polyamide composition.
According to the preparation method of the invention, preferably, in the step (1), caprolactam, a ring-opening agent and an antioxidant are subjected to low-temperature reaction under an inert atmosphere and then subjected to high-temperature reaction; wherein the temperature of the low-temperature reaction is 60-100 ℃, the pressure of the low-temperature reaction is 0.1-0.4 MPa, the time of the low-temperature reaction is 0.3-2 h, the temperature of the high-temperature reaction is 200-250 ℃, the pressure of the high-temperature reaction is 1.5-3.0 MPa, and the time of the high-temperature reaction is 1-3 h.
According to the preparation method of the invention, preferably, in the step (2), the flame retardant is added into the reaction product, and the high-pressure reaction and the vacuum reaction are firstly carried out; wherein the temperature of the high-pressure reaction is 220-280 ℃, the pressure of the high-pressure reaction is 2.5-5 MPa, the time of the high-pressure reaction is 1-3 h, the temperature of the vacuum reaction is 230-290 ℃, the pressure of the vacuum reaction is-1.1-0.6 MPa, and the time of the vacuum reaction is 2-6 h.
According to the preparation method of the present invention, preferably, in the step (2), the high pressure reaction and the vacuum reaction are performed under stirring at a speed of 150 to 300 rpm.
The flame-retardant polyamide composition is obtained by reacting raw materials including caprolactam, a ring-opening agent, an antioxidant and a flame retardant, and has good flame retardant performance and melt-drip resistance.
Detailed Description
The present invention will be further described with reference to the following specific examples, but the scope of the present invention is not limited thereto.
< flame retardant Polyamide composition >
The flame-retardant polyamide composition is obtained by reacting raw materials comprising caprolactam, a ring-opening agent, an antioxidant and a flame retardant. The flame retardant of the invention has a structure represented by formula (I):
wherein n is an integer of 2-4. Preferably, n is an integer of 2 to 3. More preferably, n is 2.
R1Is selected from alkyl of C1-C5, cycloalkyl of C3-C6 and aryl of C6-C10. Examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl. Examples of C3-C6 cycloalkyl include, but are not limited to, cyclopropyl, cyclopentyl, cyclohexane. Examples of aryl groups of C6 to C10 include, but are not limited to, the following structures:
in certain embodiments, R1Is selected from C2-C4 alkyl and C6-C8 aryl. Examples of C2-C4 alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl. Examples of aryl groups of C6 to C8 include, but are not limited to, the following structures:
in other embodiments, R1Is phenyl.
R2、R3Are each independently selected from- (CH)2)x-NH2And- (CH)2)y-COOH, x and y are each independently selected from integers of 0 to 3, such as 0, 1, 2, 3. Preferably, R2、R3Are each independently selected from-NH2-COOH. In certain embodiments, R2、R3Are all-NH2. In other embodiments, R2、R3Are all-COOH. In still other embodiments, R2is-NH2And R is3is-COOH.
R4Selected from hydrogen atoms and alkyl groups of C1-C4. Examples of C2-C4 alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl. In certain embodiments, R4Selected from hydrogen atoms and alkyl groups of C1-C2. Examples of C1-C2 alkyl groups include, but are not limited to, methyl, ethyl. In other embodiments, R4Is a hydrogen atom.
According to a specific embodiment of the present invention, the flame retardant is compound a. This results in a flame retardant polyamide composition with better flame retardancy and drip resistance.
The ring-opening agent may be 0.1 to 15 parts by weight, preferably 1 to 10 parts by weight, and more preferably 3 to 8 parts by weight, based on 100 parts by weight of caprolactam. The antioxidant may be 0.1 to 5 parts by weight, preferably 0.1 to 3 parts by weight, and more preferably 0.5 to 1 part by weight. The amount of the flame retardant is 0.1 to 15 parts by weight, preferably 1 to 10 parts by weight, and more preferably 3 to 8 parts by weight. This may lead to better flame retardancy of the flame retardant polyamide composition.
According to a specific embodiment of the invention, the raw materials comprise 100 parts by weight of caprolactam, 0.1-15 parts by weight of ring-opening agent, 0.1-5 parts by weight of antioxidant and 0.1-15 parts by weight of flame retardant. According to another specific embodiment of the invention, the raw materials comprise 100 parts by weight of caprolactam, 1-10 parts by weight of ring-opening agent, 0.1-3 parts by weight of antioxidant and 1-10 parts by weight of flame retardant. According to another specific embodiment of the invention, the raw materials comprise 100 parts by weight of caprolactam, 3-8 parts by weight of ring-opening agent, 0.5-1 part by weight of antioxidant and 3-8 parts by weight of flame retardant.
According to a preferred embodiment of the invention, the starting material comprises 100 parts by weight of caprolactam, 1 part by weight of antioxidant, 5 parts by weight of ring-opener and 5 parts by weight of flame retardant. According to another preferred embodiment of the invention, the starting material comprises 100 parts by weight of caprolactam, 1 part by weight of antioxidant, 5 parts by weight of ring-opener and 7.5 parts by weight of flame retardant. According to a further preferred embodiment of the invention, the starting material comprises 100 parts by weight of caprolactam, 1 part by weight of antioxidant, 5 parts by weight of ring-opener and 10 parts by weight of flame retardant.
The ring-opening agent of the present invention may be selected from at least one of deionized water and aminocaproic acid. Preferably, the ring-opener is water. According to a specific embodiment of the present invention, the ring-opener is deionized water. This may lead to better flame retardancy of the flame retardant polyamide composition.
The antioxidant of the present invention may be at least one selected from the group consisting of antioxidant 1010 (pentaerythritol tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate) and antioxidant 168 (tris [2, 4-di-tert-butylphenyl ] phosphite). Preferably, the antioxidant is a mixture of antioxidant 1010 and antioxidant 168. More preferably, the mass ratio of the antioxidant 1010 to the antioxidant 168 is 1: 0.5-2. According to a specific embodiment of the present invention, the antioxidant of the present invention is antioxidant 1010 and antioxidant 168 in a mass ratio of 1: 1. This may lead to better flame retardancy of the flame retardant polyamide composition.
< preparation method >
The preparation method of the flame-retardant polyamide composition comprises the following steps: (1) reacting caprolactam, a ring-opening agent and an antioxidant to obtain a reaction product; (2) adding a flame retardant into the reaction product, and continuously reacting to obtain the flame-retardant polyamide composition.
In the step (1), caprolactam, a ring-opening agent and an antioxidant are subjected to low-temperature reaction in an inert atmosphere, and then high-temperature reaction is carried out. Examples of inert atmospheres include, but are not limited to, nitrogen, helium.
In the step (1), the pressure of the low-temperature reaction may be 0.1 to 0.4MPa, preferably 0.1 to 0.3MPa, and more preferably 0.15 to 0.25 MPa. The temperature of the low-temperature reaction is 60-100 ℃, preferably 70-90 ℃, and more preferably 75-85 ℃. The time of the low-temperature reaction is 0.3-2 h, preferably 0.3-1.5 h, and more preferably 0.5-1 h. This may lead to better flame retardancy of the flame retardant polyamide composition.
In the step (1), the pressure of the high-temperature reaction may be 1.5 to 3.0MPa, preferably 2 to 3MPa, and more preferably 2 to 2.5 MPa. The temperature of the high-temperature reaction is 200-250 ℃, preferably 210-240 ℃, and more preferably 220-230 ℃. The high-temperature reaction time is 1-3 h, preferably 1.5-2.5 h, and more preferably 2-2.5 h. This may lead to better flame retardancy of the flame retardant polyamide composition.
In the step (2), the flame retardant is added into the reaction product, and high-pressure reaction and vacuum reaction are carried out firstly. For example, the flame retardant is added to the reaction product under normal pressure, and the temperature of the high-pressure reaction may be 220 to 280 ℃, preferably 230 to 270 ℃, and more preferably 230 to 250 ℃. The pressure of the high-pressure reaction can be 2.5-5 MPa, preferably 3-5 MPa, and more preferably 3.5-4.5 MPa. The high-pressure reaction time can be 1-3 h, preferably 1.5-2.5 h, and more preferably 2-2.5 h. This may lead to better flame retardancy of the flame retardant polyamide composition.
In the step (2), the temperature of the vacuum reaction can be 230-290 ℃, preferably 240-280 ℃, and more preferably 260-280 ℃. The pressure of the vacuum reaction may be-1.1 to-0.6 MPa, preferably-1.0 to-0.7 MPa, more preferably-0.8 to-0.7 MPa. The vacuum reaction time can be 2-6 h, preferably 3-5 h, and more preferably 4-5 h. This may lead to better flame retardancy of the flame retardant polyamide composition.
In the step (2), the high pressure reaction and the vacuum reaction may be performed under stirring. The stirring speed may be 150 to 300rpm, preferably 150 to 250rpm, and more preferably 200 to 250 rpm. This accelerates the reaction.
Preparation example 1 Compound a
Phenylphosphonium dichloride (5.85g, 0.03mol) was added dropwise over 2h to a mixture of 1, 4-phenylenediamine (3.348g, 0.031mol) and triethylamine (6.06g, 0.06mol) at 5 ℃ to form a reaction mixture. The reaction mixture was stirred at 80 ℃ for 5h to give the reaction product. The reaction product was filtered and then dried at 100 ℃ for 12h to give compound a.
Example 1
Reacting 100 parts by weight of caprolactam, 0.5 part by weight of antioxidant 1010, 0.5 part by weight of antioxidant 168 and 5 parts by weight of deionized water in a nitrogen atmosphere at 0.2MPa and 80 ℃ for 0.5h, and then reacting at 2.2MPa and 220 ℃ for 2h to obtain a reaction product. Adding 5 parts by weight of flame retardant (compound a) into the reaction product under normal pressure, reacting for 2h at the temperature of 3.9MPa and 250 ℃ under the stirring condition of the rotating speed of 200rpm, and then reacting for 4h at the temperature of-0.8 MPa and 260 ℃ to obtain a melt reactant. And cooling and pelletizing the melt reactant to obtain the flame-retardant polyamide composition.
Example 2
Reacting 100 parts by weight of caprolactam, 0.5 part by weight of antioxidant 1010, 0.5 part by weight of antioxidant 168 and 5 parts by weight of deionized water in a nitrogen atmosphere at 0.2MPa and 80 ℃ for 0.5h, and then reacting at 2.2MPa and 220 ℃ for 2h to obtain a reaction product. 7.5 parts by weight of a flame retardant (compound a) was added to the reaction product under normal pressure, and the mixture was reacted at 3.9MPa and 250 ℃ for 2 hours and then at-0.8 MPa and 260 ℃ for 4 hours under stirring at a rotation speed of 200rpm to obtain a melt reactant. And cooling and pelletizing the melt reactant to obtain the flame-retardant polyamide composition.
Example 3
Reacting 100 parts by weight of caprolactam, 0.5 part by weight of antioxidant 1010, 0.5 part by weight of antioxidant 168 and 5 parts by weight of deionized water in a nitrogen atmosphere at 0.2MPa and 80 ℃ for 0.5h, and then reacting at 2.2MPa and 220 ℃ for 2h to obtain a reaction product. 10 parts by weight of a flame retardant (compound a) was added to the reaction product under normal pressure, and the mixture was reacted at 3.9MPa and 250 ℃ for 2 hours and then at-0.8 MPa and 260 ℃ for 4 hours under stirring at a rotation speed of 200rpm to obtain a melt reactant. And cooling and pelletizing the melt reactant to obtain the flame-retardant polyamide composition.
Examples of the experiments
The flame-retardant polyamide compositions obtained in the above examples were subjected to the limiting oxygen index, UL-94 rating, dripping property and self-extinguishing time tests, and the results are shown in Table 1. The test method is as follows:
1. limiting Oxygen Index (LOI) test
The limit oxygen index test refers to the standard GB/T2405.2-2009 combustion behavior determination by oxygen index method for plastics, and the limit oxygen index is determined by a limit oxygen index determinator at room temperature. Spline specification: 80mm by 10mm by 4 mm.
UL-94 testing
The vertical combustion test refers to the standard of GB/T2408-2008 'Plastic combustion Performance test method horizontal method and vertical method', and is carried out at room temperature by adopting a CFZ-5 vertical combustion tester. Spline specification: 125mm by 3.2 mm.
TABLE 1
Serial number
LOI
UL-94
Molten drop
Self-extinguishing time/s
Example 1
29
V-0
Without dripping
5
Example 2
31
V-0
Without dripping
5
Example 3
32
V-0
Without dripping
4
The present invention is not limited to the above-described embodiments, and any variations, modifications, and substitutions which may occur to those skilled in the art may be made without departing from the spirit of the invention.