EA031761B1 - Polyolefin-based fire-resistant structural polymer composition - Google Patents

Abstract

The invention is related to fire-proof compositions intended for production of strong and hard polymer materials having a load-bearing capacity. The objective of the disclosed technical solution is development of a polyolefin-based fire-resistant structural polymer composition having burning resistance category V-0 while retaining physical and mechanical properties. Said objective is attained by provision of a polyolefin-based fire-resistant structural polymer composition comprising high-density polyethylene or polypropylene and including ammonium polyphosphate as a fire retardant, wherein the fire retardant includes additionally melamine, pentaerithrite, magnesium hydroxide, the composition further includes stearic acid as a modifier, and Richvin 944 as a heat stabilizer, with the following proportion of components, wt.%: ammonium polyphosphate - 15-25, magnesium hydroxide - 1-10, melamine - 2-6.5, pentaerithrite - 1.5-6, stearic acid - 0.5-1, heat stabilizer (Richvin 944) - 0.5-1, high-density polyethylene or polypropylene - the balance.

Description

The invention relates to flame retardant compositions intended for the manufacture of durable and solid polymeric materials with bearing capacity. The objective of the proposed technical solution is to develop a fire-resistant structural polymer composition based on polyolefins, having the category of resistance to combustion PV-0 while maintaining physical and mechanical characteristics. This object is achieved in that in a fire-retardant structural polymer composition based on polyolefins containing high density polyethylene or polypropylene, and as a combustion retardant, ammonium polyphosphate, the combustion retardant additionally contains melamine, pentaerythritol, magnesium hydroxide, contains stearic acid as a modifier, and in as thermostabilizer Richvin 944 in the following ratio of components, wt.%: ammonium polyphosphate - 15-25, magnesium hydroxide - 1-10, melamine - 2-6.5, pentaerythritol - 1.5-6, stear oic acid - 0.5-1, a heat stabilizer (944 Richvin) - 0,5-1, high density polyethylene or polypropylene rest.

031761 B1

The invention relates to flame retardant compositions intended for the manufacture of durable and solid polymeric materials with bearing capacity.

The composition is granules and is made on the basis of high density polyethylene or polypropylene with the introduction of modifying additives that regulate fire resistance and physico-mechanical properties.

Materials based on polyethylene and polypropylene are the most widely used polymeric materials. They have high mechanical strength, high resistance to shock loads, resistance to aggressive media and moisture, electrical insulation properties. One of the main disadvantages that inhibit the use of polyolefin materials is their high combustibility. These polymers burn, forming a melt, which can be sprayed in the form of burning droplets. In accordance with modern requirements, it is necessary to use materials with reduced flammability, not forming toxic products of thermal decomposition and combustion. As combustion retardants for the manufacture of structural materials, as a rule, organic and inorganic compounds of nitrogen and phosphorus, oxides and hydroxides of divalent and trivalent metals are used [1].

However, the use of expensive organic compounds leads to a sharp rise in the cost of materials, and the introduction of inorganic flame retardants leads to a decrease in physical and mechanical characteristics.

Known molding composition and products made of it, manufactured by extrusion molding [2], relating to polymeric materials with reduced combustibility, based on polypropylene. Reducing the flammability of polypropylene without compromising the physicomechanical properties of the resulting polypropylene granulate with reduced flammability provides the following content of components (wt.%): Polypropylene granulate - 85.2; m-phenylenediamine - 0.24; SiO ₂ 0.45; Fe ₂ O ₃ - 0.35; CaO 0.80; MgO - 0.79; Na ₂ O - 0.70; K ₂ O - 0.75; Sb ₂ O ₃ - 0.41; paraffin - 1.03; soot - 2.44; antioxidant - 1.0; dye 4.0; talc - the rest. The disadvantage of this composition is the use of antimony oxide, which in a heated polymer layer forms toxic products when exposed to fire. The efficiency of reducing combustibility is determined by the value of the oxygen index obtained during testing of a material made by extrusion molding of polypropylene granulate. This method is not indicative enough to obtain the fire retardant characteristics of the test material due to the tendency to melt formation and its attenuation due to entrapment.

Known fire-resistant material [3] related to structural composite materials based on ultra-high molecular weight polyethylene used for industrial production of fire-resistant products by pressing. The fire-resistant material contains ultra-high molecular weight polyethylene (80 wt.%), Taken in powder form with a powder particle size of 20-50 microns, and ammonium polyphosphate (20 wt.%) With a powder particle size of not more than 10 microns. The manufacture of fire-resistant material is a technologically laborious and expensive process due to the need to obtain polyethylene in powder form. In addition, it does not ensure uniformity of the resulting composite.

The closest technical solution to the claimed invention is a flame retardant composition [4] based on polyolefins (HDPE, HDPE or polypropylene), containing ammonium polyphosphate and urea block copolymer with diethylene glycol bis (4-methyl-3-isocyanatophenyl) carbamate, additionally contains polyamide and styrene-butadiene thermoplastic elastomer with a content of bound styrene of 27-47%. Assessment of resistance to burning for the PV-0 category consists in determining the time of self-combustion of the sample, which should not exceed 10 s. The disadvantage of this composition is the low fire resistance of the resulting polypropylene and polyethylene compositions - mainly PV-2. According to GOST 28157, with this category of fire resistance, the formation of burning droplets is allowed, and the time of self-burning of the sample after application of the flame can be 30 s. For the use of structural polymer materials in products for various purposes, materials with a fire resistance category PV-0 are required - the absence of burning droplets, the time of self-burning of the sample should not exceed 10 s.

The objective of the proposed technical solution is to develop a fire-resistant structural polymer composition based on polyolefins, having the category of resistance to combustion PV-0 while maintaining physical and mechanical characteristics.

This object is achieved in that the fire-resistant structural polymer composition based on polyolefins containing high density polyethylene or polypropylene, as a moderator of combustion - ammonium polyphosphate, a moderator of combustion additionally contains melamine, pentaerythritol, magnesium hydroxide, as a modifier contains stearic acid, and as thermostabilizer - Richvin 944 in the following ratio of components, wt.%:

- 1 031761

ammonium polyphosphate 15-25 magnesium hydroxide 1-10 melamine 2-6.5 pentaerythritol 1,5-6 stearic acid 0.5-1 thermostabilizer (Richvin 944) 0.5-1 high density polyethylene rest

or polypropylene

Example 1. A fire-resistant structural polymer composition is prepared by mixing powdered components with a particle size not exceeding 100 microns, with the following content, wt.%: Ammonium polyphosphate - 25 (TU 6-47-15); magnesium hydroxide - 1 (TU 6-09-3759); melamine - 6.5 (GOST 7579); pentaerythritol - 6 (GOST 9286), stearic acid - 1 (GOST 6484) and heat stabilizer (Richvin 944 - poly [[6 - [(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazine- 2,4-diyl] [(2,2,6,6-tetramethyl-4piperidinyl) imino] -1,6-hexanediyl [(2,2,6,6-tetramethyl-4-piperidinyl) imino]] - 0, 5 (Rich Yu Chemical Co., Ltd., Taiwan) on any mixing equipment, such as a concrete mixer, at a stirring speed of 40 rpm - the mixing time is 5-10 minutes and then combining the resulting mixture with a polypropylene melt 60 (GOST 26996) in a twin-screw extruder Further processing of the composition is carried out in an ex ruder in the temperature range 190-210 ° C for 5-7 minutes, the resulting composition is a uniform throughout the volume of the mass of material that is subjected to granulation at the exit of the extruder. 10 mm wide and 3 mm thick.

Other examples of formulations of polymer compositions obtained analogously to example 1 are presented in table. one.

Table 1

Composition components The content of components in the composition, mass. % Proto- type of Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 ammonium polyphosphate fifteen 25 twenty fifteen fifteen twenty 25 magnesium hydroxide one 5.5 10 10 5.5 one melamine 6.5 4.25 2 2 4.25 6.5 pentaerythritol 6 3.75 1,5 1,5 3.75 6 stearic acid - one 0.75 0.5 0.5 0.75 one heat stabilizer (Richvin 944) - 0.5 0.75 one one 0.75 0.5 polyamide 6 urea block copolymer with diethylene glycolbis- (4-methyl-3isocyanatophenyl) carbamate fifteen styrene butadiene thermoplastic elastomer four - - - - - - polypropylene 60 60 65 70 high density polyethylene - - - - 70 65 60

The burning resistance category of polymer compositions was determined according to GOST 28157 (method B).

Materials classified as PV-0 according to GOST 28157 (method B) must satisfy the following requirements:

the burning time of the sample should not exceed 10 s after each application of the flame;

the total burning time of a series of five samples after a double application of flame should not exceed 50 s;

none of the samples should burn or smolder before clamping;

Absorbent surgical cotton wool 300 mm below the specimen must not

- 2 031761 ignited by falling particles of a substance;

no sample should burn or smolder for more than 30 s after the second removal of the flame.

The results of determining the category of resistance to burning and physico-mechanical characteristics of polymer compositions are presented in table. 2.

The data presented in table. 2, confirm that the proposed fire-resistant structural composition based on polyolefins in terms of resistance to combustion belongs to the category PV-0 according to GOST 28157 (method B).

Thus, the claimed technical solution allows to produce a composition that meets the category of resistance to combustion PV-0 while maintaining physical and mechanical characteristics (yield strength under tension and elongation).

Information sources.

1. Aseeva P.M. Combustion of polymer materials / R.M. Aseeva, G.E. Zaikov // M. Science, 1981, p. 255, 259.

2. Patent RU No. 2483922, IPC B29C 70/62, C09K 21/14, B29C 47/00, 06/10/2013.

3. Patent RU No. 2350642, IPC C09K 21/14, C09K 21/04, C08L 23/06, 03/27/2009.

4. Patent BY No. 5296. IPC C08L 23/06, 23/12, 75/02, 77/00, C09K 21/14, 06/30/2003 (prototype).

table 2

Characteristics Samples Proto type Example 1 (5 samples) Example 2 (5 samples) Example 3 (5 samples) Example 4 (5 samples) Example 5 (5 samples) Example 6 (5 samples) one 2 3 four 5 one 2 3 four 5 one 2 3 four 5 one 2 3 four 5 one 2 3 four 5 one 2 3 four 5 Burning time after the first application of flame, s 0 0 one one 0 0 0 0 one 0 2 one one one one 0 one one 0 0 2 one 2 one 0 0 one 2 one one Burning time after the second application of flame, s one 2 one 0 2 2 2 one 0 one four 5 0 one 5 3 2 four one 2 5 3 2 one 3 2 four four 3 2 Smoldering time after the second application of flame, s 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 The total burning time of a series of five samples, s 8 7 21 fourteen 22 twenty Samples burnt to clamp no no no no no no no no no no no no no no no no no no no no no no no no no no no The presence of falling particles igniting cotton no no no no no no no no no no no no no no no no no no no no no no no no no no Resistance Category burning by GOST 28157 PV-2 PV-0 PV-0 PV-0 PV-0 PV-0 PV-0 Yield strength at stretching MPa 23.9 29.2 32.8 37.5 25.3 22.8 23,4 Elongation at break,% 49.8 37 42 48 350 328 335

Claims (1)

CLAIM Fire-resistant polyolefin-based polymer construction composition containing high-density polyethylene or polypropylene, and ammonium polyphosphate as a flame retardant, characterized in that the flame retardant further contains melamine, pentaerythritol, magnesium hydroxide, as a modifier contains stearic acid, and as a heat stabilizer poly [[6 - [(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazin-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidinyl) imino] -1,6-hexanediyl [(2,2,6,6-tetramethyl-4-piperidinyl) imino]] (Richvin 944) with the following ratio of components, wt.%: ammonium polyphosphate - 15-25, magnesium hydroxide - 1-10, melamine - 2-6.5, pentaerythritol - 1.5-6, stearic acid - 0.5-1, poly [[6 - [(1.1, 3,3-tetramethylbutyl) amino] -1,3,5-triazin-2,4-diyl] [(2,2,6,6-tetramethyl-4piperidinyl) imino] -1,6-hexanediyl [(2.2 , 6,6-tetramethyl-4-piperidinyl) imino]] - 0.5 (heat stabilizer - Richvin 944) - 0.5-1, high-density polyethylene or polypropylene - the rest.