CN109135046B - Flame-retardant polyolefin composition and preparation method thereof - Google Patents

Abstract

The invention discloses a flame-retardant polyolefin composition which comprises the following components in parts by weight: 100 parts of polyolefin resin; 0.5-10 parts of brominated flame retardant; 0.5-10 parts of phosphorus flame retardant; 0.1-2 parts of flame-retardant synergist. The phosphorus flame retardant is at least one selected from hypophosphite, phosphate and polyphosphate. The flame-retardant polyolefin composition has the advantages of excellent flame retardance, surface gloss, transparency and the like.

Description

Flame-retardant polyolefin composition and preparation method thereof

Technical Field

The invention relates to the technical field of macromolecules, in particular to a flame-retardant polyolefin composition and a preparation method thereof.

Background

The polyolefin resin comprises polyethylene, polypropylene, polyvinyl acetate and various olefin copolymers, wherein the polypropylene is one of the most widely used general plastics due to excellent comprehensive performance, good cost performance and wider processing and forming conditions. Polyolefin resin is mostly flammable material, for example, polypropylene has a limited oxygen index of 17-18%, is extremely easy to burn, cannot be self-extinguished after being ignited, and the polyolefin resin such as polypropylene must be subjected to flame retardant modification along with the gradual increase of the safety requirement of the material.

The flame retardant for polyolefin is mainly divided into brominated flame retardant and halogen-free flame retardant, and in the existing flame-retardant modified polyolefin, in order to meet the requirement of non-halogenation, flame retardant containing phosphorus, nitrogen or a compound system of phosphorus and nitrogen is required to be added. At present, the most common phosphorus-containing flame retardant and the composition thereof mainly comprise an intumescent flame retardant system taking phosphate and ammonium polyphosphate as main bodies and the like. However, compared with the traditional bromine-antimony compound flame retardant system, the flame retardant system has the defects of large addition amount, poor physical properties and the like, and has great limitation in wide application.

Chinese patent 201010154587.3 discloses a flame retardant composition with phosphinate and melamine hydrobromide as main components, which can make polypropylene reach UL 94V-2 flame retardant level, but the flame retardant synergist in the components contains elements such as antimony, bismuth and the like, which can reduce the transparency of the material. Meanwhile, antimony and compounds thereof are used as typical heavy metal non-renewable mineral resources, so that the price is high, the problems of environmental pollution and health damage are easily caused in the processing process, and the antimony-free flame-retardant formula system effectively solves the problems.

Chinese patent 200980131213.5 discloses a polypropylene composition containing a mixture of tris (tribromoneopentyl) phosphate and a carbon-carbon initiator as a flame retardant component, which does not contain antimony trioxide, can meet the flame retardant rating of UL 94V-1 or V-0, but has a higher flame retardant addition amount.

With the continuous improvement of application requirements of downstream industries, besides the requirements on conventional performances such as flame retardant performance, physical performance and the like, more and more products are expected to have better surface gloss and transparency, and the performances of the conventional flame retardant systems such as bromine-antimony, halogen-free expansion and the like are difficult to satisfy in the aspects.

Disclosure of Invention

The invention aims to provide a flame-retardant polyolefin composition which has the advantages of excellent flame retardance, surface gloss, transparency and the like.

It is another object of the present invention to provide a method for preparing the above flame retardant polyolefin composition.

The invention is realized by the following technical scheme:

a flame-retardant polyolefin composition comprises the following components in parts by weight:

100 parts of polyolefin resin;

0.5-10 parts of brominated flame retardant;

0.5-10 parts of phosphorus flame retardant;

0.1-2 parts of flame-retardant synergist.

Preferably, the composition comprises the following components in parts by weight:

100 parts of polyolefin resin;

1-5 parts of brominated flame retardant;

1-5 parts of a phosphorus flame retardant;

0.15-1 part of flame-retardant synergist.

More preferably, the composition comprises the following components in parts by weight:

100 parts of polyolefin resin;

1-3 parts of a brominated flame retardant;

1-3 parts of a phosphorus flame retardant;

0.2 to 0.5 portion of flame retardant synergist.

The brominated flame retardant is selected from at least one of organic brominated flame retardants; the organic brominated flame retardant is selected from at least one of decabromodiphenylethane, tetrabromobisphenol A bis (2, 3-dibromopropyl) ether, tris (tribromoneopentyl) phosphate, tris (2, 3-dibromopropyl) isocyanurate, brominated imine, brominated epoxy resin, tris (tribromophenoxy) triazine, tetrabromobisphenol A and tetrabromobisphenol S bis (2, 3-dibromopropyl) ether.

The average grain diameter of the brominated flame retardant is 1-10 microns; preferably, the average particle size of the brominated flame retardant is 1-5 microns. The particle size is too large, the dispersing effect of the flame retardant is poor, and the surface gloss and transparency of the product are reduced more.

The phosphorus flame retardant is at least one selected from hypophosphite, phosphate and polyphosphate; the hypophosphite is selected from at least one of aluminum hypophosphite, calcium hypophosphite, dimethyl aluminum hypophosphite, diethyl aluminum hypophosphite and methyl ethyl aluminum hypophosphite; the phosphate is selected from at least one of triphenyl phosphate, resorcinol bis (diphenyl phosphate), bisphenol A-bis (diphenyl phosphate) and oligomeric aryl phosphate; the polyphosphate is selected from at least one of ammonium polyphosphate, melamine phosphate, melamine pyrophosphate and melamine polyphosphate. Wherein the polymerization degree of the oligomeric aryl phosphate is 2-10.

The average grain diameter of the phosphorus flame retardant is 1-10 microns; preferably, the average particle size of the phosphorus flame retardant is 1-5 microns. The particle size is too large, the dispersing effect of the flame retardant is poor, and the surface gloss and transparency of the product are reduced more.

The flame retardant synergist is selected from at least one of a compound (I) and/or at least one of a compound (II);

the general formula of the compound (I) is

Wherein R1, R2, R3 or R4 are respectively any one of C1-12 alkyl, C1-12 alkoxy, C6-12 aryl or C6-12 aryloxy; preferably C1-12 alkyl; more preferably C1-4 alkyl; x or Y is any one of H, C1-12 alkyl, C1-12 alkoxy, C6-12 aryl, C6-12 aryloxy, halogen, nitro, sulfonic group or polysubstituted aryl; preferably H or C1-12 alkyl;

the compound (II) has the general formula

Wherein R5 is any one of C1-12 alkyl, C1-12 alkoxy, C6-12 aryl or C6-12 aryloxy; preferably C1-12 alkyl; more preferably C1-4 alkyl; n is 2 to 20; preferably 2 to 10; more preferably 3-6.

Flame retardant synergist such as poly (1, 4-diisopropylbenzene) (n is 3-10), 2, 3-dimethyl-2, 3-diphenylbutane.

The polyolefin resin is at least one selected from polyethylene resin and polypropylene resin. Such as random copolymer polypropylene, homo-polypropylene, high density polyethylene, etc.

0-1 part of antioxidant and 0-1 part of processing aid are also included according to the parts by weight; the antioxidant is selected from at least one of phenols, amines, phosphites, semi-hindered phenols, calixarenes and dilauryl thiodipropionate; the processing aid is at least one of low molecular weight lipid, metal soap, stearic acid composite ester and amide. Such as: the processing aid can be lubricant calcium stearate; the antioxidant can be antioxidant 1010 and antioxidant 168.

The flame-retardant polyolefin composition has the surface gloss of more than or equal to 70 degrees, the light transmittance of more than or equal to 68 percent and the haze of less than or equal to 92 percent, wherein the surface gloss adopts the GB 8807-1988 standard, the light transmittance adopts the GB/T2410-2008 standard, and the haze adopts the GB/T2410-2008 standard.

Preferably, the flame-retardant polyolefin composition has the surface gloss of more than or equal to 77 ℃, the light transmittance of more than or equal to 74 percent and the haze of less than or equal to 88 percent, the surface gloss adopts GB 8807-1988 standard, the light transmittance adopts GB/T2410-2008 standard and the haze adopts GB/T2410-2008 standard.

According to the flame-retardant polyolefin composition, the particle size of the flame retardant in the product has a large influence on the surface gloss, the light transmittance and the haze, the particle size of the flame retardant is large, and the dispersion of the flame retardant in the product is nonuniform, so that the surface gloss and the light transmittance are reduced, and the haze is increased.

The preparation method of the flame-retardant polyolefin composition comprises the following steps:

A) weighing polyolefin resin, a brominated flame retardant, a phosphorus flame retardant and a flame retardant synergist in proportion, and uniformly mixing the weighed materials by a high-speed mixer;

B) and melting, extruding, granulating and drying at 180-200 ℃ by a double-screw extruder to obtain the flame-retardant polyolefin composition.

Antioxidants and processing aids can also be added in the step A).

The invention has the following beneficial effects:

according to the invention, the brominated flame retardant, the phosphorus flame retardant and the flame retardant synergist are compounded, so that the flame retardant polyolefin composition can have the flame retardant grade of UL-94V-2 (0.8-3.2 mm) under the condition of only adding a small amount of flame retardant, and has the advantages of excellent surface gloss and transparency.

Detailed Description

The present invention is further illustrated by the following specific examples, which are, however, not intended to limit the scope of the invention.

The raw materials used in the examples and comparative examples are the following, but the present invention is not limited to the following:

high density polyethylene: dow chemical company;

homo-polypropylene: exxon Mobil corporation;

random copolymerized polypropylene: exxon Mobil corporation;

2, 3-dimethyl-2, 3-diphenylbutane: tanzhou Zhufeng Fine chemical Co., Ltd;

poly 1, 4-diisopropylbenzene: n is 3-10, Tanzhou Zhufeng Fine chemical Co., Ltd;

poly 1, 4-diisopropylbenzene: n is 3-6, Tanzhou Zhufeng Fine chemical Co., Ltd;

decabromodiphenylethane a: the average particle size was 2.5 microns;

decabromodiphenylethane B: the average particle size was 6.0 microns;

aluminum hypophosphite A: the average particle size was 1.5 microns;

aluminum hypophosphite B: the average particle size was 5.5 microns;

tris (2, 3-dibromopropyl) isocyanurate: the average particle size was 2.0 microns;

melamine pyrophosphate: the average particle size was 2.0 microns.

The rest of the raw materials are commercially available.

Examples, comparative examples preparation of flame retardant polyolefin compositions: weighing polyolefin resin, a brominated flame retardant, a phosphorus flame retardant, a flame-retardant synergist, an antioxidant and a processing aid in proportion, uniformly mixing the materials through a high-speed mixer, then carrying out melt extrusion at 200 ℃ through a double-screw extruder, granulating and drying to obtain the flame-retardant polyolefin composition.

The performance test method comprises the following steps:

(1) UL-94, 3.2 mm: according to the UL-94 standard, the thickness of the test sample strip is 3.2 mm;

(2) UL-94, 1.6 mm: according to the UL-94 standard, the thickness of the test sample strip is 1.6 mm;

(3) UL-94, 0.8 mm: according to the UL-94 standard, the thickness of the test sample strip is 0.8 mm;

(4) surface gloss: the angle is tested to be 60 degrees according to the GB 8807-1988 standard;

(5) light transmittance: according to the GB/T2410-2008 standard, the thickness of a test sample is 1.0 mm;

(6) haze: according to the GB/T2410-2008 standard, the thickness of the test sample is 1.0 mm.

Note: the criterion for transparency includes both light transmittance and haze, the higher the light transmittance and the lower the haze the better the transparency.

(7) The detection method of the average particle size of the flame retardant comprises the following steps: preparing the compound into a sample wafer, freezing the sample wafer in liquid nitrogen for 5 minutes, then brittle fracture, observing the shape and size of the flame retardant with the section of 50 x 50 microns by adopting SEM, and counting the average particle size of the flame retardant within the range.

Table 1: EXAMPLES 1 to 11 respective component ratios (parts by weight) and respective results of performance tests

	Practice of Example 1	Practice of Example 2	Practice of Example 3	Practice of Example 4	Practice of Example 5	Practice of Example 6	Practice of Example 7	Practice of Example 8	Practice of Example 9	Practice of Example 10	Practice of Example 11
												Homo-polypropylene	100	100	100	100	100	100	100	100	-	-	100
Random copolymerized polypropylene	-	-	-	-	-	-	-	-	100	-	-
												High density polyethylene	-	-	-	-	-	-	-	-	-	100	-
Decabromodiphenylethane A	0.5	1	2	5	10	1	1	-	1	1	1
												Decabromodiphenylethane B	-	-	-	-	-	-	-	1	-	-	-
Aluminium hypophosphite A	1	1	1	1	1	5	10	-	1	1	1
												Aluminum hypophosphite B	-	-	-	-	-	-	-	1	-	-	-
Poly 1, 4-diisopropyl Benzene (n is 3-10)	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.6
												Antioxidant 1010	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1
Antioxidant 168	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2
												Lubricant calcium stearate	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2
UL-94,3.2mm	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2
												UL-94,1.6mm	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2
UL-94,0.8mm	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2	V-2
												Surface gloss, degree	83	83	80	77	70	83	80	82	85	77	83
Light transmittance%	82	80	78	74	68	76	74	77	86	80	79
												Haze%	78	80	83	88	92	84	89	83	52	77	82

Table 2: examples 12 to 18 and comparative examples 1 to 4 were each in the component ratio (parts by weight) and the results of each performance test

	Practice of Example 12	Practice of Example 13	Practice of Example 14	Practice of Example 15	Practice of Example 16	Practice of Example 17	Practice of Example 18	Comparison of Example 1	Comparison of Example 2	Comparison of Example 3	Comparison of Example 4
												Homo-polypropylene	100	100	100	100	100	100	100	100	100	100	100
Decabromodiphenylethane A	-	-	-	-	1	1	1	5	-	2	1
												Tetrabromobisphenol a bis (2, 3-dibromopropyl) ether	1	-	-	-	-	-	-	-	-	-	-
Tris (tribromoneopentyl) Phosphoric acid esters	-	1	-	-	-	-	-	-	-	-	-
												Tris (2, 3-dibromopropane) Alkyl) isocyanurate Esters	-	-	1	1	-	-	-	-	-	-	-
Aluminium hypophosphite A	1	-	1	-	-	1	1	-	10	-	1
												Bisphenol A-bis (diphenyl) Radical phosphate ester)	-	1	-	1	-	-	-	-	-	-	-
Melamine pyrophosphoric acid Salt (salt)	-	-	-	-	1	-	-	-	-	-	-
												Antimony trioxide	-	-	-	-	-	-	-	-	-	1	-
Poly 1, 4-diisopropyl Benzene (n is 3-10)	0.2	0.2	0.2	0.2	0.2	-	-	0.2	0.2	0.2	-
												2, 3-dimethyl-2, 3-diphenylbutane	-	-	-	-	-	0.2	-	-	-	-	-
Poly 1, 4-diisopropyl Benzene (n is 3-6)	-	-	-	-	-	-	0.2	-	-	-	-
												Antioxidant 1010	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1
Antioxidant 168	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2
												Lubricant calcium stearate	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2
UL-94,3.2mm	V-2	V-2	V-2	V-2	V-2	V-2	V-2	NR	NR	NR	NR
												UL-94,1.6mm	V-2	V-2	V-2	V-2	V-2	V-2	V-2	NR	NR	NR	NR
UL-94,0.8mm	V-2	V-2	V-2	V-2	V-2	V-2	V-2	NR	NR	NR	NR
												Surface gloss, degree	86	83	83	81	81	83	83	71	80	81	83
Light transmittance%	83	82	80	82	78	80	81	82	76	45	80
												Haze%	73	70	77	78	83	82	79	78	87	98	80

Note: NR means that the lowest level is not reached

As can be seen from examples 1-7, the present invention achieves a flame retardant rating of UL-94V-2 with a lower amount of flame retardant and has high surface gloss and transparency, wherein the lower the amount of flame retardant used, the higher the surface gloss and transparency; from example 2 and example 8, it can be seen that when the average flame-retardant particle size of the brominated flame retardant and the phosphorus flame retardant is 1 to 5 μm, the surface gloss and the transparency are better. From example 2 and example 11, it can be seen that the flame retardant synergist amount exceeds 0.5 parts, which does not improve the flame retardant performance, but reduces the transparency. As can be seen from examples 2 and 18, the clarity of the examples using poly (1, 4-diisopropylbenzene) (n is 3 to 6) is better.

Claims (16)

1. The flame-retardant polyolefin composition is characterized by comprising the following components in parts by weight:

100 parts of polyolefin resin;

0.5-10 parts of brominated flame retardant;

0.5-10 parts of phosphorus flame retardant;

0.1-2 parts of flame-retardant synergist;

the flame retardant synergist is selected from a compound (II) with a general formula

Wherein R5 is any one of C1-12 alkyl, C1-12 alkoxy, C6-12 aryl or C6-12 aryloxy; n is 2 to 20;

the average grain diameter of the brominated flame retardant is 1-10 microns; the average grain diameter of the phosphorus flame retardant is 1-10 microns.

2. The flame retardant polyolefin composition according to claim 1, comprising the following components in parts by weight:

100 parts of polyolefin resin;

1-5 parts of brominated flame retardant;

1-5 parts of a phosphorus flame retardant;

0.15-1 part of flame-retardant synergist.

3. The flame retardant polyolefin composition according to claim 2, comprising the following components in parts by weight:

100 parts of polyolefin resin;

1-3 parts of a brominated flame retardant;

1-3 parts of a phosphorus flame retardant;

0.2 to 0.5 portion of flame retardant synergist.

4. A flame retardant polyolefin composition according to any of claims 1-3 wherein the brominated flame retardant is selected from at least one of organic brominated flame retardants; the organic brominated flame retardant is selected from at least one of decabromodiphenylethane, tetrabromobisphenol A bis (2, 3-dibromopropyl) ether, tris (tribromoneopentyl) phosphate, tris (2, 3-dibromopropyl) isocyanurate, brominated imine, brominated epoxy resin, tris (tribromophenoxy) triazine, tetrabromobisphenol A and tetrabromobisphenol S bis (2, 3-dibromopropyl) ether.

5. The flame retardant polyolefin composition according to claim 4 wherein the brominated flame retardant has an average particle size of 1 to 5 μm.

6. A flame retardant polyolefin composition according to any of claims 1-3 wherein the phosphorus based flame retardant is selected from at least one of hypophosphite salts, phosphate esters, polyphosphate salts; the hypophosphite is selected from at least one of aluminum hypophosphite, calcium hypophosphite, dimethyl aluminum hypophosphite, diethyl aluminum hypophosphite and methyl ethyl aluminum hypophosphite; the phosphate is selected from at least one of triphenyl phosphate, resorcinol bis (diphenyl phosphate), bisphenol A-bis (diphenyl phosphate) and oligomeric aryl phosphate; the polyphosphate is selected from at least one of ammonium polyphosphate, melamine phosphate, melamine pyrophosphate and melamine polyphosphate.

7. The flame retardant polyolefin composition according to claim 6, wherein the phosphorus-based flame retardant has an average particle size of 1 to 5 μm.

8. A flame retardant polyolefin composition according to any of claims 1-3 wherein in compound (ii) n is 2-10.

9. Flame retardant polyolefin compositions according to claim 8 wherein in compound (II) n is 3 to 6.

10. Flame retardant polyolefin composition according to any of claims 1-3, wherein R5 is a C1-12 alkyl group.

11. Flame retardant polyolefin composition according to claim 10, wherein R5 is a C1-4 alkyl group.

12. The flame retardant polyolefin composition according to any one of claims 1 to 3, wherein the polyolefin resin is at least one selected from the group consisting of polyethylene resins and polypropylene resins.

13. The flame retardant polyolefin composition according to any of claims 1 to 3, further comprising 0 to 1 part by weight of an antioxidant, 0 to 1 part by weight of a processing aid; the antioxidant is selected from at least one of phenols, amines, phosphites, semi-hindered phenols, calixarenes and dilauryl thiodipropionate; the processing aid is at least one of low molecular weight lipid, metal soap, stearic acid composite ester and amide.

14. The flame retardant polyolefin composition according to any one of claims 1 to 13, wherein the flame retardant polyolefin composition has a surface gloss of 70 ℃ or higher, a light transmittance of 68% or higher and a haze of 92% or lower, the surface gloss being in accordance with GB 8807-.

15. The flame retardant polyolefin composition according to any of claims 2-13, wherein the flame retardant polyolefin composition has a surface gloss of 77 ℃ or higher, a light transmittance of 74% or higher and a haze of 88% or lower, the surface gloss being determined by GB 8807-.

16. A process for the preparation of a flame retardant polyolefin composition according to any of claims 1 to 15, characterized in that it comprises the following steps:

A) weighing polyolefin resin, a brominated flame retardant, a phosphorus flame retardant and a flame retardant synergist in proportion, and uniformly mixing the weighed materials by a high-speed mixer;

B) and melting, extruding, granulating and drying at 180-200 ℃ by a double-screw extruder to obtain the flame-retardant polyolefin composition.