CN111057316B

CN111057316B - Non-sticking ammonium polyphosphate flame-retardant modified polypropylene material and preparation method thereof

Info

Publication number: CN111057316B
Application number: CN201911338655.9A
Authority: CN
Inventors: 刘华夏; 谢思正; 左晓佛; 周侃; 李章武
Original assignee: Presafer Qingyuan Phosphor Chemical Co ltd
Current assignee: Chizhou Jushi Chemical Co ltd
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2022-03-29
Anticipated expiration: 2039-12-23
Also published as: CN111057316A

Abstract

The invention discloses a non-stick mold ammonium polyphosphate flame retardant modified polypropylene material, which is made of the following components in parts by weight: polypropylene resin: 58-70 parts; ammonium polyphosphate-based flame retardant masterbatch: 28-40 parts; acid binding agent: 0.1-1 part; main antioxidant 1010: 0.1-0.2 part; auxiliary antioxidant 168: 0.2-0.3 part; lubricant EBS: 0.1-1 part; anti-drip agent: 0.1 to 0.5 parts. The invention discloses a preparation method thereof, comprising the following steps: weighing and mixing the above-mentioned raw materials except an acid binding agent according to a set formula, using a twin-screw extruder for melt extrusion and granulation, and during the extrusion process, acid binding The agent is added from the exhaust port of the extruder through the liquid feeder, and is injected into a standard spline for various tests. The polypropylene material provided by the invention has the characteristics of halogen-free flame retardant and non-stick mold for injection molding, and provides a broader application prospect for the halogen-free flame retardant polypropylene with high cost performance.

Description

Non-sticking ammonium polyphosphate flame-retardant modified polypropylene material and preparation method thereof

Technical Field

The invention relates to the field of high polymer materials, in particular to a non-sticking ammonium polyphosphate flame-retardant modified polypropylene material and a preparation method thereof.

Background

Polypropylene (PP) is one of five general-purpose plastics, and is widely used in many fields such as injection molding and film and fiber production. However, as a plastic, PP itself has the flammability defect of most plastics, and PP needs to be modified in flame retardation to obtain a PP material with excellent performance and more safety.

Flame retardants for PP are classified into halogenated flame retardants and halogen-free flame retardants according to the presence or absence of halogen. With the increasing awareness of environmental protection, halogen flame retardants generate toxic substances when acting, and halogen-free flame retardants for PP are increasingly gaining attention. Among them, the most widely used halogen-free flame retardant is an intumescent flame retardant based on Ammonium polyphosphate (APP), which has the characteristics of low smoke, no halogen and environmental protection when used for combustion of PP products. But APP is a polymer, the polymerization degree distribution exists, a few of APP with low polymerization degree can be decomposed to generate ammonia gas and metaphosphoric acid at the polypropylene processing temperature, metaphosphoric acid remained in polypropylene can be separated out under the influence of temperature and pressure during injection molding, so that the sticking of a mold is caused, and the appearance of a product is seriously influenced. And the precipitate on the die has strong adhesion, so that the die is worn during cleaning.

At present, most of developers prevent decomposition during processing by coating or surface modifying ammonium polyphosphate. For example, the silicon-aluminum hydrogel double-layer coating modified ammonium polyphosphate flame retardant disclosed in Chinese patent CN201410606689.2 is used for modifying polypropylene, and the limit oxygen index, UL-94 vertical combustion grade, thermal stability, char forming ability and the like of the prepared polypropylene material are all remarkably improved. The principle of the methods is that the decomposition of the ammonium polyphosphate is reduced by improving the compatibility with a PP base material or reducing the heat generated by friction between the ammonium polyphosphate flame retardant and the screw and PP particles. However, ammonium polyphosphate is a polymer, and has a distribution of polymerization degree, and some ammonium polyphosphate with low polymerization degree still exists under the existing ammonium polyphosphate synthesis process conditions, and the ammonium polyphosphate with low polymerization degree has the characteristic of low thermal decomposition temperature, and the coating and surface treatment on the ammonium polyphosphate cannot change the property. At the temperature at which the PP is completely molten, the low degree of polymerization APP tends to decompose to produce metaphosphoric acid and ammonia.

Therefore, a novel non-sticking ammonium polyphosphate flame-retardant modified polypropylene material and a preparation method thereof are provided.

Disclosure of Invention

The invention aims to provide a non-sticking ammonium polyphosphate flame-retardant modified polypropylene material and a preparation method thereof, and particularly relates to a non-sticking ammonium polyphosphate flame-retardant modified polypropylene material which uses organic alkali as an acid-binding agent to neutralize generated metaphosphoric acid during processing, uses ammonium polyphosphate flame-retardant master batches to reduce friction heat generated by directly using powder, reduces metaphosphoric acid in final particles in two ways, and achieves the purpose that the prepared polymer particle material is not stuck to a mold during injection molding.

In order to achieve the purpose, the invention provides the following technical scheme:

a non-sticking ammonium polyphosphate flame-retardant modified polypropylene material is characterized in that: the composite material is prepared from the following components in parts by weight:

polypropylene resin: 58-70 parts of a solvent;

ammonium polyphosphate based flame retardant masterbatch: 28-40 parts;

acid binding agent: 0.1-1 part;

main antioxidant: 0.1-0.2 parts;

auxiliary antioxidant: 0.2-0.3 part;

lubricant: 0.1-1 part;

anti-dripping agent: 0.1 to 0.5 portion.

The ammonium polyphosphate based flame-retardant master batch is a halogen-free flame-retardant master batch with good dispersibility, and is specifically prepared by taking ammonium polyphosphate as an acid source, melamine as an air source, triazine derivatives as a carbon source, polypropylene as a carrier, a lubricant and an antioxidant as components, and adopting banburying, double-stage extrusion and water ring granulation processes.

Wherein the ammonium polyphosphate has a number average polymerization degree of 1000-1050, a density of 1.8-1.9 g/cm3, a pH value (25 ℃, 10% suspension) of 6.5-7.0, a viscosity (25 ℃, 10% suspension) of 45-50 mPa & s, a phosphorus content of 31-32% by weight and a nitrogen content of 14.5-15.5% by weight.

The preferable melamine has the pH value (25 ℃, 10% suspension) of 5.0-6.0, the particle size of 4-6 mu m, the phosphorus content of 12.0-13.0 wt% and the nitrogen content of 42.0-44.0 wt%.

The preferable triazine derivative has a molecular structure formula of one of the compounds shown in the following (1), (2) and (3):

wherein R is₁、R₂Is H, C₆H₅、C₆H₄OH, morpholine, piperidine, C_yH_2y—O—R₃Y is more than or equal to 1 and less than or equal to 8), R₃Is H, C₁-C₈Alkyl of (C)₂-C₆One of alkenyl groups of (a).

Wherein, the structural formula of X is (4) or (5), and in the structural formula (5), Z is more than or equal to 2 and less than or equal to 6.

The polypropylene melt refers to one or more of homo-polypropylene, block co-polypropylene and random co-polypropylene in a range of 0.5-60 g/10min (test standard: ASTM D1238, test condition: 230 ℃/2.16 Kg).

The preparation method of the ammonium polyphosphate based flame-retardant master batch comprises the following steps:

1) firstly, mixing polypropylene, a lubricant and an antioxidant according to a set formula proportion, stirring for 2-3 minutes by using a high-speed mixer, and then adding a flame retardant into the high-speed mixer and stirring for 3-5 minutes;

2) the uniformly stirred materials are put into a pressurized rolling internal mixer to be mixed until the materials are preliminarily plasticized, the internal mixer is operated to stop running, and the materials are poured into a lifter;

3) and (3) feeding the materials in the hoister into a double-screw extruder through a double-cone forced feeding machine, conveying and cooling the materials through a single-screw extruder, and pelletizing the materials by using a water ring pelletizing mode.

The main antioxidant is hindered phenol antioxidant: pentaerythritol tetrakis [ methyl- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] (antioxidant 1010), with phosphite antioxidant: tris (2, 4-di-tert-butylphenyl) phosphite (antioxidant 168); the hindered phenol antioxidant can terminate the tertiary carbon free radical in PP, and the phosphite antioxidant can decompose peroxide to prevent the generation of the tertiary carbon free radical in PP, and the hindered phenol antioxidant and the phosphite antioxidant have obvious synergistic effect in combination.

The lubricant is one of N, N' -Ethylene Bis Stearamide (EBS), polyethylene wax, stearic acid and oxidized polyethylene wax, has polar amide groups, can be inserted into the PP resin, reduces the interaction among the resin molecules, and plays a role in internal lubrication; or the resin melt is internally transferred to the surface, so that the mutual friction between the resin particle product and the melt and equipment is reduced, and the external lubrication effect is realized.

The acid-binding agent is organic alkali, and specifically is at least one of triethylamine, pyridine and triethanolamine.

The preparation method of the non-sticking ammonium polyphosphate flame-retardant modified polypropylene material is characterized by comprising the following steps of:

1) firstly, mixing polypropylene resin, ammonium polyphosphate-based flame-retardant master batch, a lubricant, a main antioxidant 1010, an auxiliary antioxidant 168 and an anti-dripping agent according to a set formula proportion, stirring for 3-5 minutes by using a high-speed mixer at the rotating speed of 1000-1500 revolutions per minute, and putting the uniformly stirred materials into a double-screw main feed;

2) feeding the coupling agent into the acid binding agent through a double-screw exhaust port by using a liquid feeder;

3) and (3) starting the double-screw extruder, adjusting the temperature and the rotating speed of the double screws, adjusting the feeding speeds of the main feeding device, the side feeding device and the liquid feeding device, starting vacuum, and extruding and granulating to obtain the non-sticking ammonium polyphosphate flame-retardant modified polypropylene material.

The liquid feeder used in the step 2) is a heat-preservation weightless scale liquid feeding device, the feeding precision is +/-0.5%, and the liquid dripping inlet is connected with the air outlet, so that the dripping inlet and the air outlet are in the same closed environment.

And 3) arranging air draft devices above the main feeding port, the liquid feeding port and the discharge port of the double-screw extruder used in the step 3).

The invention has the following beneficial effects:

1) the material provided by the invention has a reasonable formula, the acid-binding agent used by the invention is organic alkali, metaphosphoric acid generated by decomposing low-polymerization-degree ammonium polyphosphate can be neutralized during processing, the generated stable salt does not influence subsequent processing, and residual gas is extracted through a double-screw vacuum device;

2) the ammonium polyphosphate based flame-retardant master batch used by the material provided by the invention can reduce heat generated by friction with a screw, a gun barrel and resin particles when powder is directly used, is beneficial to dispersion of a flame retardant and is beneficial to improvement of flame-retardant efficiency.

3) The polypropylene material provided by the invention has the characteristics of halogen-free flame retardance and no sticking of injection molding, and provides a wider application prospect for the halogen-free flame retardant polypropylene with high cost performance.

4) The preparation method provided by the invention has the advantages of compact process and easy industrialization.

Drawings

FIG. 1 is a schematic view showing the state of a sample after thermal oxidative aging at 135 ℃ for 7 days of the material prepared in example 1 of the present invention;

FIG. 2 is a schematic view showing the state of a sample after thermal oxidative aging at 135 ℃ for 7 days of the material prepared in example 2 of the present invention;

FIG. 3 is a schematic view showing the state of a sample after thermal oxidative aging at 135 ℃ for 7 days of the material prepared in example 3 of the present invention;

FIG. 4 is a schematic view showing the state of a sample after thermal oxidative aging at 135 ℃ for 7 days of the material prepared in comparative example 1 of the present invention;

FIG. 5 is a schematic view showing the state of a sample after thermal oxidative aging at 135 ℃ for 7 days of the material prepared in comparative example 2 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-5, the non-stick molding ammonium polyphosphate flame-retardant modified polypropylene material provided by the invention is prepared from the following components in parts by weight: polypropylene resin: 58-70 parts of a solvent; ammonium polyphosphate based flame retardant masterbatch: 28-40 parts; acid binding agent: 0.1-1 part; main antioxidant: 0.1-0.2 parts; auxiliary antioxidant: 0.2-0.3 part; lubricant: 0.1-1 part; anti-dripping agent: 0.1 to 0.5 portion.

The ammonium polyphosphate based flame-retardant master batch is prepared by taking ammonium polyphosphate as an acid source, melamine as an air source, triazine derivatives as a carbon source and polypropylene as a carrier. Wherein:

the ammonium polyphosphate has a number average polymerization degree of 1000-1050, a density of 1.8-1.9 g/cm3, a pH value (25 ℃, 10% suspension) of 6.5-7.0, a viscosity (25 ℃, 10% suspension) of 45-50 mPa & s, a phosphorus content of 31-32% by weight, and a nitrogen content of 14.5-15.5% by weight.

Melamine, pH value (25 ℃, 10% suspension) is 5.0-6.0, particle size is 4-6 μm, phosphorus content is 12.0-13.0% wt, and nitrogen content is 42.0-44.0% wt.

Triazine derivatives, the structural formula of which is one of the compounds shown in the following figures (1), (2) and (3),

Polypropylene, wherein the melt index is one or more of homo-polypropylene, block copolymerization polypropylene and random copolymerization polypropylene within 0.5-60 g/10min (test standard: ASTM D1238, test condition: 230 ℃/2.16 Kg);

1) firstly, mixing polypropylene, a lubricant and an antioxidant according to a set formula proportion, stirring for 2-3 minutes by using a high-speed mixer, and then adding a flame retardant into the high-speed mixer to stir for 3-5 minutes.

2) And (3) putting the uniformly stirred materials into a pressurized rolling internal mixer for internal mixing until the materials are preliminarily plasticized, operating the internal mixer to stop operating, and pouring the materials into a lifter.

The polypropylene resin, the lubricant and the antioxidant used in the preparation of the ammonium polyphosphate flame-retardant master batch are consistent with a formula of a non-stick ammonium polyphosphate flame-retardant modified polypropylene material.

The acid-binding agent is an organic base and comprises at least one of triethylamine, pyridine and triethanolamine;

the anti-dripping agent is a pure powder type anti-dripping agent.

The primary antioxidant is a preferred hindered phenol antioxidant: pentaerythritol tetrakis [ methyl- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] (antioxidant 1010), with the preferred phosphite antioxidant: tris (2, 4-di-tert-butylphenyl) phosphite (antioxidant 168). The hindered phenol antioxidant can stop the tertiary carbon free radical in the PP, and the phosphite antioxidant can decompose the peroxide to prevent the generation of the tertiary carbon free radical in the PP, and the hindered phenol antioxidant and the phosphite antioxidant have obvious synergistic effect in combination.

The lubricant is preferably N, N' -Ethylene Bis Stearamide (EBS) which has polar amide groups and can be inserted into PP resin to reduce the interaction between resin molecules and play a role in internal lubrication. And the resin melt can also migrate to the surface from the inside of the resin melt, so that the mutual friction between a resin particle workpiece and the melt and equipment is reduced, and the external lubrication effect is realized. In addition, polyethylene wax, stearic acid and oxidized polyethylene wax can be selected as the lubricant, and the effect is similar to that of the N, N' -ethylene bis stearamide.

The invention provides a preparation method of the non-sticking ammonium polyphosphate flame-retardant modified polypropylene material, which comprises the following steps:

1) firstly, mixing polypropylene resin, ammonium polyphosphate flame-retardant master batch, a lubricant EBS, a main antioxidant 1010, an auxiliary antioxidant 168 and an anti-dripping agent according to a set formula proportion, stirring for 5-8 minutes by using a high-speed mixer at the rotating speed of 500-800 revolutions per minute, and putting the uniformly stirred materials into a double-screw main feed;

2) feeding an acid binding agent from a double-screw exhaust port by using a liquid feeder;

3) starting the double-screw extruder, adjusting the temperature and the rotating speed of the double screws, adjusting the feeding speeds of the main feeding device, the side feeding device and the liquid feeding device, and starting vacuum;

4) and (4) using a water tank for water cooling, cooling by a blower, and granulating by a granulator to obtain the final finished product particle material.

Wherein, the liquid feeder is a weightlessness scale liquid feeding device, and the feeding precision is +/-0.5%.

Wherein the liquid feed inlet is connected with the exhaust port, and the whole connecting position is in a closed environment.

The double screws used in the method are parallel co-rotating double screw extruders with the length-diameter ratio of 40: 1-55: 1.

The temperature of the extruder of the double-screw extruder is set to be 170-180 ℃ in the first zone, 180-185 ℃ in the second-fourth zone, 170-175 ℃ in the fifth-sixth zone, 190-195 ℃ in the seventh-ninth zone, 180-185 ℃ in the tenth-eleventh zone, 170-180 ℃ in the nose, 150-350 r/min in rotation speed and-0.05-2.0 MPa in vacuum degree.

Air draft devices are arranged above a main feeding port, a liquid feeding port, a vacuum port and a discharge port of the double-screw extruder;

the mechanical test of the invention refers to the ASTM D638 plastic tensile property test method, and the sample strips which meet the standard are prepared and the tensile property test is carried out. With reference to the standard ASTM D790 for the flexural strength of unreinforced and reinforced plastics and electrical insulation materials, standard-compliant test bars were prepared and tested for flexural properties. With reference to the standard ASTM D256 plastic impact test method, test bars meeting the standard were prepared and subjected to impact test. Density measurements were made with reference to the standard ASTM D792 Plastic Density and relative Density test method. The melt index is measured by reference to the test method of measuring the flow rate of thermoplastics melt with extruded plastics according to the standard ASTM D1238.

The flame retardant test of the invention refers to the UL94 plastic material flammability standard to carry out flame retardant performance test, the sample strip is prepared according to the UL94 standard, the thickness is 1.5 +/-0.2 mm and 3.0 +/-0.1 mm, so as to verify the performance of the material.

The thermal oxidation aging test of the invention refers to a GB-T7141-2008 plastic thermal aging test method to verify the performance of the material.

Example 1

The non-stick molding ammonium polyphosphate flame-retardant modified polypropylene material provided by the embodiment is prepared from the following components in parts by weight:

the polypropylene resin is copolymerized polypropylene: 60.5 parts; ammonium polyphosphate based flame retardant masterbatch: 38 parts of (B); the acid-binding agent is triethylamine: 0.5 part; the main antioxidant is hindered phenol antioxidant 1010: 0.1 part; the auxiliary antioxidant is phosphite ester antioxidant 168: 0.3 part; the lubricant is ethylene bis stearamide EBS: 0.5 part; the anti-dripping agent is a pure powder type anti-dripping agent M532: 0.3 part.

60.5Kg of a polypropylene copolymer (trademark EP300M, Mediterranean Shell) having a melt index of 8.8g/10min (test standard ASTM D1238, test conditions 230 ℃/2.16Kg) was accurately weighed, and an acid-binding agent: 0.1-1 part of hindered phenol antioxidant (brand 1010, Shandong Sanfeng chemical Co., Ltd.) 0.1Kg as a main antioxidant, 0.2Kg as a subsidiary antioxidant as a phosphite antioxidant (brand 168, Shandong Sanfeng chemical Co., Ltd.), 0.5Kg as a lubricant of ethylene bis stearamide (EBS, Japan king), 0.3Kg as a pure powder type anti-dripping agent (brand M532, Japan Dajin), and 38Kg as an ammonium polyphosphate based flame-retardant master batch (100DMB75PP, Qingyuan Puseofu phosphorus chemical Co., Ltd.).

The polypropylene melt refers to one or more of homo-polypropylene, block co-polypropylene and random co-polypropylene in a range of 0.5-60 g/10min (test standard: ASTM D1238, test condition: 230 ℃/2.16 Kg). The polypropylene copolymer in this example is a homopolypropylene.

The main antioxidant is one of the following hindered phenol antioxidants: pentaerythritol tetrakis [ methyl- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] (antioxidant 1010), with phosphite antioxidant: tris (2, 4-di-tert-butylphenyl) phosphite (antioxidant 168); the hindered phenol antioxidant can terminate the tertiary carbon free radical in PP, and the phosphite antioxidant can decompose peroxide to prevent the generation of the tertiary carbon free radical in PP, and the hindered phenol antioxidant and the phosphite antioxidant have obvious synergistic effect in combination.

The acid-binding agent is an organic base, specifically triethylamine in this embodiment.

The preparation method of the non-sticking ammonium polyphosphate flame-retardant modified polypropylene material comprises the following steps:

1) firstly, mixing weighed polypropylene resin EP300M, ammonium polyphosphate flame-retardant master batch 100DMB75PP, lubricant EBS, main antioxidant 1010, auxiliary antioxidant 168 and anti-dripping agent M532 according to a set formula proportion, stirring for 3 minutes by using a high-speed mixer at the rotating speed of 600 revolutions per minute, and putting the uniformly stirred materials into a double-screw (Nanjing Keya, the diameter of a screw is 36mm, the length-diameter ratio of 48:1) main feed;

2) acid-binding agent triethylamine (Shandong Dehua) was added to a weightlessness scale liquid feeding apparatus (model: LF-DL-50, Zhengzhou Batt melt Pump, Inc.);

3) starting an air draft device, starting a double-screw extruder, setting the temperature of the extruder to be 170-190 ℃, the rotating speed to be 250 rpm and the vacuum degree to be-1.0 MPa, and adjusting the feeding speeds of a main feeding device, a side feeding device and a liquid feeding device;

4) cooling the mixture by a water tank with the water temperature of 25 +/-5 ℃, cooling the mixture by a blower, and granulating the mixture by a granulator to obtain the final product of the granular non-sticking ammonium polyphosphate flame-retardant modified polypropylene material.

5) Drying the granular material at 85 ℃ for 3 hours, setting the injection molding temperature to be 180-195 ℃ by using a horizontal injection molding machine (HS-1200, sea stone plastic machine), performing injection molding to obtain a standard sample strip, standing at 23 ℃ and 50% humidity for 48 hours, and testing.

Examples 2 and 3

The non-stick molding ammonium polyphosphate flame-retardant modified polypropylene material and the preparation method thereof provided by the embodiment are basically the same as the embodiment 1, except that the material is prepared from the following components in parts by weight, and the details are shown in table 1.

Example 4

The non-stick molding ammonium polyphosphate flame-retardant modified polypropylene material and the preparation method thereof provided by the embodiment are basically the same as those in the embodiments 1 to 3, and the difference is that the material is prepared from the following components in parts by weight:

the polypropylene resin is copolymerized polypropylene: 70 parts of (B); ammonium polyphosphate based flame retardant masterbatch: 40 parts of a mixture; the acid-binding agent is triethanolamine: 1 part; the main antioxidant is hindered phenol antioxidant: 0.2 part; the auxiliary antioxidant is phosphite ester antioxidant: 0.2 part; the lubricant is ethylene bis stearamide EBS: 1 part; the anti-dripping agent is a pure powder type anti-dripping agent M532: 0.5 part.

Wherein the polypropylene copolymer is selected from block polypropylene copolymer and random polypropylene copolymer

Wherein the acid-binding agent is triethanolamine (TEA 99, Asia-Dong petrochemical).

Example 5

The non-stick molding ammonium polyphosphate flame-retardant modified polypropylene material and the preparation method thereof provided by the embodiment are basically the same as those in the embodiments 1 to 4, and the difference is that the material is prepared from the following components in parts by weight:

the polypropylene resin is copolymerized polypropylene: 58 parts of a mixture; ammonium polyphosphate based flame retardant masterbatch: 28 parts of (1); the acid-binding agent is pyridine: 0.1 part; the main antioxidant is hindered phenol antioxidant: 0.15 part; the auxiliary antioxidant is phosphite ester antioxidant: 0.25 part; the lubricant is ethylene bis stearamide EBS: 0.1 part; the anti-dripping agent is a pure powder type anti-dripping agent M532: 0.1 part.

Wherein the copolymerized polypropylene is random copolymerized polypropylene.

Wherein the acid-binding agent is pyridine (brand 110-86-1, chemical industry of Minnan Chuangshi).

Comparative example 1

The procedure was followed as described in example 1, except that no acid-binding agent was added.

Comparative example 2

The procedure was carried out in accordance with the formulation and preparation method described in example 1, except that ammonium polyphosphate based halogen-free flame retardant powder (100D, manufactured by Puseofur chemical Co., Ltd., Qingyuan) was used in an amount of 28 parts.

Examples 1 to 3, and comparative examples 1 to 3, the formulations had the following compositions in Table 1:

for the materials prepared in examples 1-3, the following results of the flame retardant tests of comparative examples 1-2 are shown in Table 2:

table 2 flame retardant test results are compared.

The results of the physical property tests of the materials prepared in examples 1-3 and comparative examples 1-2 are shown in the following Table 3:

table 3 comparison of physical Property test results

The samples obtained in examples 1 to 3 were aged by thermal oxidation at temperatures of from 1 to 2135 ℃ for 21 days, and the conditions of the samples are shown in FIG. 1.

The test results of the materials prepared in examples 1-3 after thermal oxidative aging in comparative examples 1-2 are shown in Table 4 below:

TABLE 4 comparison of thermo-oxidative aging test results

As can be seen from the data in Table 2, the flame retardant effects of the first, second, and third examples and the first comparative example are similar, and the second comparative example shows a longer flame retardant time in the UL941.5mm V-0 test. The reason may be that the dispersion effect is inferior to that of the flame-retardant master batch using the powdery flame retardant.

As can be seen from the data in Table 3, the mechanical data of the second comparative example is lower than those of the first, second, third and first comparative examples in that the tensile property, elongation at break and impact strength of the formulation using the powder flame retardant are not as good as those of the flame retardant masterbatch, which is mainly due to the fact that the difference between the polarity of the ammonium polyphosphate flame retardant and that of PP is large and the compatibility is poor. Meanwhile, the powder flame retardant is not as uniform as the flame-retardant master batch in dispersion, and has larger damage to the integrity of the base material, so that the mechanical property is seriously reduced.

As can be seen from FIG. 1, the precipitates of the first, second and third examples are minimal, and the precipitate of the first example is severe when the second example is compared with the first example. Ammonium polyphosphate having a low degree of polymerization decomposes at the complete melting temperature of PP, and the generated metaphosphoric acid remains in the final particles, and is inevitably precipitated with time at a certain temperature. The experimental result of fig. 1 shows that the acid-binding agent can neutralize the excessive metaphosphoric acid generated by the thermal decomposition of ammonium polyphosphate with low polymerization degree. Compared with a powder flame retardant, the flame-retardant master batch has the advantages of small friction heat in the processing process and relatively less decomposition of ammonium polyphosphate. The comprehensive beneficial effects of the modified polypropylene with the ammonium polyphosphate-based flame retardant are applied to the injection molding process of PP, so that the modified polypropylene with the ammonium polyphosphate-based flame retardant is not adhered to a mold during injection molding, the appearance of a finished piece is not affected, and a wider application prospect is provided for the halogen-free flame retardant polypropylene with high cost performance.

As can be seen from the data in Table 4, the ammonium polyphosphate-based halogen-free flame retardant is not ideal for the thermo-oxidative stability of polypropylene, because ammonium ions in the ammonium polyphosphate can be converted into ammonia and overflow out of the system in the continuous heating process, so that the reaction process is carried out in the reverse direction to the negative reaction, and as the time is prolonged, the flame retardant is decomposed and the flame retardant effect disappears. The experimental result also shows that the acid-binding agent has no obvious effect on the thermal oxygen stability of the finished product.

It should be noted that, in the above embodiments of the present invention, each component and specific ingredient are not listed, and within the scope of the present invention, the components can be specifically selected according to the needs, and all technical effects described in the present invention can be achieved.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents, and the invention is not limited to the embodiments described above, and various modifications and changes may be made without departing from the spirit and scope of the invention, and it is intended that all changes and modifications that fall within the scope of the invention are embraced in the appended claims.

Claims

1. a non-stick mold ammonium polyphosphate flame retardant modified polypropylene material, is characterized in that: it is made of the component of following weight portion ratio:

Polypropylene resin: 58~70 parts;

Ammonium polyphosphate flame retardant masterbatch: 28~40 parts;

Acid binding agent: 0.1~1 part;

Main antioxidant: 0.1~0.2 parts;

Auxiliary antioxidant: 0.2~0.3 parts;

Lubricant: 0.1~1 part;

Anti-drip agent: 0.1~0.5 parts;

The acid binding agent is an organic base, specifically at least one of triethylamine, pyridine and triethanolamine.

2. The non-stick ammonium polyphosphate flame retardant modified polypropylene material according to claim 1, wherein the ammonium polyphosphate flame retardant master batch is a halogen-free flame retardant master batch with good dispersibility, Specifically, ammonium polyphosphate is used as acid source, melamine is used as gas source, triazine derivatives are used as carbon source, polypropylene is used as carrier, lubricant and antioxidant are used as components. Made by dicing process;

Among them, ammonium polyphosphate has a number-average degree of polymerization of 1000-1050 and a density of 1.8-1.9 g/cm3. At 25°C, the pH value of a 10% suspension is 6.5-7.0, and the viscosity is 45-50 mPa·s. The phosphorus content is 31~32%wt, and the nitrogen content is 14.5~15.5%wt;

Melamine, at 25℃, the pH value of 10% suspension is 5.0~6.0, the particle size is 4~6μm, the phosphorus content is 12.0~13.0%wt, and the nitrogen content is 42.0~44.0%wt;

Triazine derivatives, the molecular structure is one of the compounds shown in the following (1), (2), (3):

Wherein, R ₁ and R ₂ are one of H, C ₆ H ₅ , C ₆ H ₄ OH, morpholine, piperidine, C _y H _2y —O—R ₃ , 1≤y≤8; R ₃ is One of H, C ₁ -C ₈ alkyl, C ₂ -C ₆ alkenyl;

Wherein, the structural formula of X is (4) or (5), and in structural formula (5), 2≤Z≤6;

The polypropylene has one or more of homopolymerized polypropylene, block copolymerized polypropylene and random copolymerized polypropylene with a melting point of between 0.5 and 60 g/10min.

3. The non-stick ammonium polyphosphate flame retardant modified polypropylene material according to claim 2, wherein the preparation method of the ammonium polyphosphate flame retardant master batch comprises the following steps:

1) First, mix the polypropylene, lubricant and antioxidant according to the set formula ratio, use a high-speed mixer to stir for 2~3 minutes, and then add the flame retardant to the high-speed mixer and stir for 3~5 minutes;

2) Put the well-stirred material into the pressurized tumbling mixer to refine the material until the material is initially plasticized, operate the mixer to stop the operation and pour the material into the elevator;

3) The material in the elevator is fed into the twin-screw extruder through the double-cone forced feeder, and then conveyed through the single-screw extruder to cool down, and pelletized by water ring pelletizing.

4. The non-stick mold ammonium polyphosphate flame retardant modified polypropylene material according to claim 1, wherein the main antioxidant is a hindered phenolic antioxidant: tetrakis[methyl-(3.5-dicarbonate]) tert-Butyl-4-hydroxyphenyl)propionic acid] pentaerythritol ester (antioxidant 1010), with phosphite antioxidant: tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168); wherein the hindered phenolic antioxidant can terminate the tertiary carbon free radicals in PP, while the phosphite antioxidant can decompose peroxides and prevent the generation of tertiary carbon free radicals in PP. synergistic effect.

5. The non-stick mold ammonium polyphosphate flame retardant modified polypropylene material according to claim 1, wherein the lubricant is N,N'-ethylenebisstearamide (EBS), polyethylene One of wax, stearic acid, oxidized polyethylene wax, which has polar amide group, which can be inserted into PP resin to reduce the interaction between resin molecules and play the role of internal lubrication; or by resin melt The inside migrates to the surface, reducing the mutual friction between resin particle parts, melt and equipment, and plays the role of external lubrication.

6. The preparation method of the non-stick mold ammonium polyphosphate flame retardant modified polypropylene material according to one of claims 1-5, characterized in that, it comprises the steps:

1) First, mix polypropylene resin, ammonium polyphosphate flame retardant masterbatch, lubricant, main antioxidant 1010, auxiliary antioxidant 168, and anti-drip agent according to the set formula ratio, and use a high-speed mixer to stir 3 ~5 minutes, the speed of the mixer is 1000~1500 rpm, and the mixed material is put into the twin-screw main feeder;

2) Then use the liquid feeder to feed the acid binding agent through the twin-screw exhaust port;

3) Turn on the twin-screw extruder, adjust the twin-screw temperature and screw speed, adjust the feeding speed of the main feeding, side feeding, and liquid feeding device, turn on the vacuum, extrude and granulate, and obtain a non-stick mold polymer. Ammonium phosphate flame retardant modified polypropylene material.

7. The method for preparing non-stick ammonium polyphosphate flame retardant modified polypropylene material according to claim 6, wherein the liquid feeder used in step 2) is a heat-insulating loss-in-weight scale liquid feeding device, and the feeding accuracy is ±0.5%, the liquid droplet inlet is connected to the exhaust port, so that the droplet inlet and the exhaust port are in the same closed environment.

8. The preparation method of non-stick ammonium polyphosphate flame retardant modified polypropylene material according to claim 6, characterized in that: the twin-screw extruder used in step 3) is in the main feeding port, liquid feeding port, Above the discharge port is equipped with a ventilation device.