RU2505554C1 - Method of producing functionalised polyolefins - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of producing functionalised polyolefins is carried out in a melt by grafting an unsaturated carboxylic acid or anhydride thereof on polyolefin in the presence of a free-radical initiator, co-agents of aromatic and aliphatic monomers, as well as chain-transfer agents based on amine and/or phosphate compounds, while extruding the mixture of reagents at temperature higher than the melting point of polyolefin in an extruder and conditioning the obtained polymer mixture by vacuum degassing. The method can also be continuous. The free-radical initiator used can be peroxide with half-life temperature of not less than 190°C per minute. The olefin polymer is selected from a group consisting of homopolymers, statistical copolymers and terpolymers of a linear or branched C2-8-alpha-olefin or copolymers of a linear or branched C2-8-alpha-olefin. The free-radical polymerised monomer is a vinyl monomer selected from a group consisting of vinyl-substituted aromatic, heterocyclic and alicyclic compounds, unsaturated aliphatic carboxylic acids and derivatives thereof, unsaturated aliphatic nitriles, vinly esters of aromatic and saturated aliphatic carboxylic acids, divinyl compound or mixtures thereof. The polymerisation co-agents used are polymers and/or monomers of the aromatic series based on styrene or butyl acrylate or aliphatic series based on octane-1 or hexane-1 or decene-1.

EFFECT: improved technology of the method.

7 cl, 4 tbl

Description

The invention relates to the chemistry of polymers, in particular, to methods for extruding and producing graft copolymers as components of an adhesive composition for insulating metal pipes. For example, such a material can be used as a compatibilizer (compatibilizer) in filled polyethylene compositions, with mineral fillers (chalk, talc, mica, wollastonite, etc.), flame retardant (Al2 (OH) 3, Mg (OH) 2), wood (DPKM).

A similar analogue is known from the prior art and EP 0086159. According to the method disclosed in European patent EP 0086159, cross-linking of α-olefin polymers and copolymers is proposed to improve the mechanical resistance characteristics when heated. The proposed solution consists in grafting a carboxylic acid in the presence of a radical generator and subsequent salt formation using metal compounds.

The closest known method for producing functionalized polyolefins RU 2243976, publ. 2003, according to which the method for producing polyolefins includes a) a step of grafting acid groups to polyolefins using a graftable monomer containing at least one functional group selected from carbonyl and an acid anhydride residue, if necessary, in the presence of another graftable monomer containing a vinyl unsaturated bond and, possibly, one or more aromatic nuclei, b) a purification step consisting in removing at least a portion of the graftable monomer that has not reacted with polyolefins, containing at least one functional group selected from carbonyl and an acid anhydride residue, and c) a step for neutralizing acid groups with at least one neutralizing agent, characterized in that the neutralization is carried out with zinc acetate to obtain polyolefins characterized by the presence of ionic clusters containing Zn ++ ions. The invention also relates to polyolefins obtained by this method, to their use and to a method for extrusion of polyolefins with foaming. The method allows to obtain polyolefins having an increase in viscosity at elongation depending on time and an increase in dynamic viscosity at low shear frequencies.

In addition, it should be noted that conventional polymer grafting technologies in the extrusion process have common disadvantages.

1) The reaction time is quite limited and is determined by the residence time of the material in the extrusion process.

2) The temperature of the extrusion process is higher than in the methods of solid-phase grafting or grafting in solution or suspension.

3) In the usual process of grafting in the melt, there are undesirable processes, the so-called "side reactions", namely: cross-linking for polyethylene or ethylene vinyl acetate, or a significant loss in molecular weight of betta-scissions for polypropylenes.

4) In conventional grafting extrusion processes, the conversion of grafted monomer is negligible and typically amounts to about 30%.

5) The presence of a significant amount of unreacted "free" acid in the polymer and, as a result, the polymer changes color from dark yellow to light brown in color and has an odor.

The claimed technology for the extrusion synthesis of graft polymers overcomes the above disadvantages.

The problem is solved by the method of obtaining functionalized polyolefins in the melt by grafting an unsaturated carboxylic acid or its anhydride onto a polyolefin in the presence of a free radical initiator, co-agents of aromatic and aliphatic monomers, as well as chain transfer agents based on amine and / or phosphate compounds, when extruding the mixture of reagents at a temperature above the melting point of the polyolefin in the extruder and conditioning the resulting polymer mixture by vacuum degassing.

Additionally, the method can be continuous, peroxides with a half-life of at least 190 ° C in one minute can be used as a free radical initiator, the olefin polymer is selected from the group consisting of homopolymers, random copolymers and ter-polymers of linear or branched C2-8- alpha olefin or linear or branched C2-8 alpha olefin copolymers; the monomer polymerized by free radicals is a vinyl monomer selected from the group consisting of vinyl substituted aromatic, heterocyclic and alicyclic compounds, unsaturated aliphatic carboxylic acids and their derivatives, unsaturated aliphatic nitriles, vinyl esters of aromatic and saturated aliphatic divides and carboxylic aliphatic divides mixtures; polymerization co-agents used are polymers and / or aromatic monomers based on styrene or butyl acrylate or an aliphatic series based on octene-1 or hexene-1 or gum-1, in an amount not exceeding 50% by weight of the grafted monomer of carboxylic acid or anhydride or mixtures thereof; as chain transfer agents, dimethylformamide and / or triphenyl phosphate are used in an amount not exceeding 10% of the weight content of the graftable carboxylic acid or anhydride monomer and mixtures thereof.

The melt flow rate (MFR) of the samples of modifiers made on the basis of PE was determined according to GOST 11645 at a temperature of 190 ° C and a load of 2.16 kg.

The density of injection samples was determined according to GOST 15139.

The selection of basic materials and reagents is shown in Table 1.

Table 1 Title The properties LLDPE 318B Density - 0.918 g / cm3 PTR (190С, 2.16 kg) - 2.8 g / 10 min Tensile Strength - 18.5 MPa Elongation - 610% LLDPE MG200024 Density - 0.924 g / cm3 PTR (190С, 2.16 kg) - 20 g / 10 min Tensile Strength - 12 MPa Elongation> 500% LLDPE M500026 Density - 0.924 g / cm3 PTR (190С, 2.16 kg) - 50 g / 10 min Tensile Strength - 12.4 MPa Elongation 120% HDPE IM 59/64 Density - 0.96-0.964 g / cm3 PTR (190С, 2.16 kg) - 13-21 g / 10 min Tensile Strength - 30 MPa Elongation> 1000% HDPE Shurtan I-1561 Density - 0.96 g / cm3 PTR (190С, 2.16 kg) - 15.5 +/- 2.5 g / 10 min Tensile Strength - 26 MPa Elongation> 500% Maleic anhydride (briquettes) The degree of purification 99.81 min Ash content 0.0007% Maleic anhydride (flakes) The degree of purification 99.5 min Ash content 0.005% Organic DTBP Peroxide (Ditretbutyl Peroxide) Description: A colorless mobile fluid containing technically pure ditretbutyl peroxide. Half-life - 10 h / 1 h / 1 min 125/146 / 190C DBM (Maleic Acid Dibutyl Ether) Description: colorless mobile fluid containing dibutyl ether of fumaric and maleic brushes. Purity min 98.5% Styrene (Phenylethylene) Description: transparent homogeneous liquid Mass fraction of styrene> 99.8% Acetone (Dimethylketone) Description: colorless clear liquid Mass fraction of acetone > 99.75% Alpha Olefins Octen-1, Decen-1, Hexen-1 Description: colorless clear liquid Molar fraction of alpha olefins> 94%

The essence of the invention lies in the fact that in addition to the functional monomer that is grafted onto the polymer, 2 types of co-monomers are used, of which:

One of a number of aliphatic di-olefins is alpha-olefins, preferably: 1-octene, 1-decene or 1-hexene.

Another is from a series of aromatic vinyl monomers or acrylates, preferably: butyl acrylate or styrene (preferably para-methyl styrene).

The total content of co-monomers ranges from 0.1-10% by weight, based on the amount of polymer.

Functional Monomer Selection

Functional monomers are preferably from a number of unsaturated carboxylic acids, for example: maleic anhydride or functional epoxy-amino-hydroxy-acrylates, for example: glycidyl methacrylate.

Maleic anhydride can preferably be dissolved in solvents (acetone or methyl ethyl ketone).

The development of technology for the production of graft copolymers was carried out using NTL equipment of CJSC Metaclay, namely:

We used the MKS 30 BUSS extrusion line with strand granulation, evacuation, dry (powders, granules) and liquid dosing.

The formulations were developed and tested on batches of 3-5 kg.

Example No. 1 The formulation of the graft copolymer for use in adhesives for pipe insulation is shown in Table 2 (using liquid input)

table 2 HDPE Shurtan 1-1561 granules 37.90% LLDPE Sabic 200024M granules 55.45% Maleic Anhydride Powder 3.00% Styrene liquid 0.50% Acetone liquid 3.00% Peroxide DTDP Liquid 0.10% Solvent DBM Liquid 0.05%

Previously, HDPE and LLDPE polyethylene were mixed and introduced by the dispenser through the main loading port.

Dimethylformamide and triphenylphosphate were added as chain transfer agents in an amount of 9.5% of the weight content of the graftable carboxylic acid monomer (it is also possible of the weight content of the anhydride or mixtures thereof).

The monomer (MLN) was dissolved in acetone and DBM, DTBP, styrene were introduced. The liquid “cocktail” was introduced both separately (into the melt in Z2) and through the main port (together with the polymers).

Example No. 2 The formulation of the graft copolymer for use in adhesives for pipe insulation is shown in Table 3.

In addition, dimethylformamide was added as a chain transfer agent in an amount of 10% of the weight content of the graftable carboxylic acid monomer.

For example 3, triphenyl phosphate was added as a chain transfer agent in an amount of 8.5% of the weight content of the graftable carboxylic acid monomer (using peroxy-polymer masterbachey, dry technology)

Table 3 HDPE Shurtan I-1561 Granules 37.90% LLDPE Sabic 200024M granules 55.45% Maleic Anhydride Powder 3.00% Peroxy polymer masterbatch - 2% Masterbatch (* LLDPE Sabic 200024M granules (96%) + DTDP Peroxide (3%) + DBM Solvent) (1%)

The peroxy polymer masterbatch is prepared in advance. (* according to the specified recipe) at an extrusion temperature of 120-135C.

A mixture of HDPE and LLDPE polyethylenes and a Peroxy polymer masterbatch were introduced by the dispenser through the main loading port.

Monomer (MAN) pre-ground into a powder was introduced through a powder dispenser into the main loading port (together with polymers)

A comparison of 2 technological processes for the production of grafted (graft) copolymers is shown in Table 4.

Table 4 Technological process Recipe 1 Recipe 2 Wet way Dry way Melt Flow Index (MFR) at 190 ° C and a load of 2.16 kg 0.6 1,0 % Grafted MAN 1,2 1.8-1.9 Chemical Titration confirms confirms IR spectroscopy confirms confirms Color yellowish natural (white) Smell residual styrene odor no smell

Samples of graft copolymers were tested at the Polymer Modification Laboratory of NIISPM named after Yenikolopova, in the Central Laboratory of Clinics of CJSC Metaclay, in the company BYK / Kometra GmbH (Germany).

FTIR spectral analysis was performed at NTL CJSC Metaclay

Physico-chemical methods of analysis.

Fourier transform infrared spectroscopy. To identify the chemical composition of the samples, the Fourier-IR method was used.

The IR spectra of the samples were recorded at the NIISP im. Enikolopova and NTL ZAO Metaklay using: Fourier-IKS Avatar 370 m. Thermo Nicolet (USA), equipped with Smart Performer self-adjusting ATR with ZnSe crystal (penetration depth 2.01 μm).

The spectra were identified using the instrument database.

The FT-IR spectrometer from the German company Bruker Optics TENSOR 27 is a compact Fourier-IR spectrometer. Powerful mid-IR spectrometer with sealed and drained optics for routine laboratory applications.

Equipment Parameters:

Spectral range 7500-370 cm-1

Standard Resolution 1 cm-1

Wave number accuracy <0.01 cm-1

Air-cooled MIR source

Constantly Adjustable Interferometer

KBR multilayer beam splitter

Non-friction mechanical scanner (no compressed gas required)

Highly Sensitive DTGS Detector

The optical bench is controlled by a micro-processor, automatic preamp selection, 32 bit A / D converter.

OPUS 6.5 software

Chemical titration. It was carried out according to the methodology of NIISPM them. Enikolopova (Russia) and the methodology of BYK / Kometra GmbH (Germany).

Differential Scanning Calorimetry (DSC). Thermograms of DSC samples were taken using a Pyris 6 DSC instrument f. PerkinElmer at a heating / cooling rate of 20 ° C / min in nitrogen atmosphere according to ISO 11357. The determination of the induction period of oxidation of samples was determined according to ISO 11357-6 at 200 ° C (for PE-based samples).

Claims (7)

1. A method for producing functionalized polyolefins in a melt by grafting an unsaturated carboxylic acid or its anhydride onto a polyolefin in the presence of a free radical initiator, coagents of aromatic and aliphatic monomers, as well as chain transfer agents based on amine and / or phosphate compounds, by extruding the mixture of reagents at a temperature higher than the melting temperature of the polyolefin in the extruder and conditioning the resulting polymer mixture by vacuum degassing. 2. The method according to claim 1, characterized in that the method is continuous. 3. The method according to claim 1 and 2, characterized in that as a free radical initiator use peroxides with a half-life of at least 190 ° C in one minute. 4. The method according to claim 1, characterized in that the olefin polymer is selected from the group consisting of homopolymers, random copolymers and terpolymers of a linear or branched C2-8 alpha olefin or copolymers of a linear or branched C2-8 alpha olefin. 5. The method according to claim 1, characterized in that the monomer polymerized by free radicals is a vinyl monomer selected from the group consisting of vinyl substituted aromatic, heterocyclic and alicyclic compounds, unsaturated aliphatic carboxylic acids and their derivatives, unsaturated aliphatic nitriles, complex vinyl esters of aromatic and saturated aliphatic carboxylic acids, divinyl compounds and mixtures thereof. 6. The method according to claim 1, characterized in that as polymerization coagents polymers and / or monomers of the aromatic series based on styrene or butyl acrylate or an aliphatic series based on octene-1 or hexene-1 or gum-1 are used in an amount not in excess of 50% by weight of the graftable monomer of carboxylic acid or anhydride or mixtures thereof. 7. The method according to claim 1, characterized in that dimethylformamide and / or triphenyl phosphate are used as chain transfer agents in an amount not exceeding 10% by weight of the graftable graft carboxylic acid or anhydride monomer and mixtures thereof.