RU2552554C2 - Method of producing polyolefin oxygen-absorbing composition for sealing pads - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to production of a polyolefin oxygen-absorbing composition for making sealing pads for sealing polymer and glass bottles with liquid foodstuffs. A method of producing a polyolefin oxygen-absorbing composition for sealing pads by mixing, in a melt, a mixture of high-pressure polyethylene with a copolymer of ethylene and vinyl acetate with a melt flow index in the range of 5-10 g/10 m and weight ratio of vinyl acetate in the range of 10-14%, target additives and sodium sulphite as an oxygen absorbent in amount of 3.6-6.0 wt %. Sodium sulphite with average particle size of 70 mcm is added to the composition in the form of a melt-derived granular polymer concentrate based on a copolymer of ethylene and vinyl acetate with a melt flow index in the range of 5-15 g/10 min and weight ratio of vinyl acetate in the range of 10-17%, containing 20-40 pts.wt sodium sulphite and 79-59 pts.wt ethylene and vinyl acetate copolymer.

EFFECT: invention improves oxygen absorption efficiency.

4 tbl, 12 ex, 3 dwg

Description

The present invention relates to a technology for the production of polymer compositions based on polyolefins and oxygen-absorbing additives for the manufacture of sealing gaskets in closures for hermetically sealing polymer and glass bottles with food liquids (fruit juices, soft drinks, beer).

Known [Food Packaging / R. Coles, D. MacDowell, M.J. Kirvan. - Per. from English under the scientific. ed. L.G. Mahotina. - St. Petersburg: Profession, 2008, p.100, 344-350] the negative effect of oxygen on food products, including drinks and beer, due to undesirable oxidative reactions and microbiological (aerobic-bacterial) processes with its participation, and such general principles minimize this effect, such as the inclusion of oxygen absorbers in the polymer gaskets of crown caps and bottle caps, connecting oxygen from free space in the neck of the bottle and penetrating (diffusing) from the outside.

In particular, it is known [US No. 6086786, MKI ⁷ C01B 3/00, publ. 2000] an oxygen-absorbing composition intended for the manufacture of a gasket between the bottle body and its stopper (cap) and which is a thermoplastic polymer matrix based on a polymer selected mainly from the group: polyethylene (preferably low density polyethylene (LDPE) - according to domestic nomenclature, this , in accordance with the production method, high pressure polyethylene (LDPE) [GOST 16377-77. High pressure polyethylene. Technical conditions. - M .: Publishing house of standards, 2001, p.1]), copolymers of ethylene with vinyl Tat (EVA), block copolymer of styrene-butadiene-styrene, polyvinyl chloride (PVC), copolymers of vinyl chloride or a mixture of some of these polymers, as well as injected therein oxygenscavenging composition comprising zero-valent metal attached to capable of cation exchange material. As such material, zeolites, or clays, or various forms of silicon dioxide are used. The metal (selected from the group of calcium, magnesium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, tin, or mixtures of some of them) is fixed in ionic form by the cation exchange method; then the deposited metal is reduced to zero state.

In addition to the listed components, the polymer matrix of the composition may include filler, sliding and processing additives, pigments, stabilizers, antioxidants and other additives - in the most preferred total amount of less than 3% by weight of the entire composition if it does not contain PVC.

In addition to the indicated preference for the use of LDPE (from all types of polyethylene) when preparing the composition according to US No. 6086786, it also states that the used SEVA must have a melt index (temperature and load when determining it, as well as its dimensionality, are not indicated) in the range is preferably 5-10 (probably g / 10 min) (the melt index according to Russian terminology is a melt flow index [Encyclopedia of Polymers. Editorial board: V. A. Kargin (chapters, ed.), etc. T. 1. - M .: Soviet Encyclopedia, 1972, stb. 844); GOST 11645-73. Plastics. Method for determining the melt flow index of thermoplastics. - M .: Publishing house of standards, 1973, p. 1]) and preferably contain from 5 to 30% (probably wt.%) Vinyl acetate (VA). In accordance with a typical example 3 US No. 6086786 oxygen-absorbing composition is obtained by applying copper sulfate CuSO ₄ · 5H ₂ O from its aqueous solution on

Zeolite Y brand zeolite, isolation of a solid product (with a copper content of 8.8 wt.%) containing copper in the form of Cu ^{2+ ions} on the surface as a result of realized cation exchange, reduction of Cu ^{2+ with} hydrogen at a temperature of 300 ° C for 24 hours to the state of Cu ⁰ and the subsequent introduction of the prepared product Cu ⁰ / zeolite by compounding in a polymer melt (using a Brabender mixer) into a mixture of LDPE and SEVA containing 28 wt.% VA, with the following components in the resulting composition: Cu ⁰ / zeolite - 10 wt.%, LDPE - 54 wt.%, SEVA - 36 wt.%.

In US No. 6086786 use a convenient (including in the context of the present invention) method for determining the effectiveness of oxygen absorption of the resulting composition. Films are prepared from the composition by pressing on a heated hydraulic press, which are then tested for their oxygen-absorbing properties by placing in the upper part of packages (made of an effective oxygen-barrier polymer material) containing 90 ml of a carbonized 3% aqueous solution of ethanol. After filling the upper space of each bag with 150 ml of air (with a content of 20.6% O ₂ ) they are heated to 65 ° C for 50 minutes. After keeping the film in such a bag for two days at room temperature, a gas sample is taken from the upper space of the bag using a syringe and the oxygen concentration is determined on a MOCON LC-700F oxygen analyzer; based on the result of the analysis, the oxygen absorption index of the resulting composition is calculated. It is 0.37 mg O _2/200 mg formulation. After five days incubation same film in the same conditions, the figure is 0.39 mg O _2/200 mg formulation. Theoretical absorption capacity for oxygen of ⁰ Cu / zeolite-containing polyolefin composition is 0.44 mg O _2/200 mg formulation. The result obtained in example 3 of US No. 6086786 is interpreted as characterizing "rapid absorption of oxygen at room temperature by the material of the gasket under the cover (stopper) containing the Cu ⁰ / zeolite obtained by ion exchange". Thus, under these conditions, this composition is characterized by a relatively short time of oxygen absorption, in just a few days, almost exhausting its oxygen absorption resource.

The disadvantage of the method for producing a polymer, including polyolefin, oxygen-absorbing composition for gaskets according to US No. 6086786 is a rather complicated technology for the preparation of the oxygen-absorbing composition included in it, especially the presence in this technology of a stage of long-term (about 24 hours) hydrogen reduction (at a temperature of about 300 ° C) of the metal deposited on the zeolite by the ion exchange method to a zero valent state.

Also known [US No. 5075362, MKI ⁵ C08K 5/13, publ. 1991] a sealing composition for gasket bottle caps and caps, including a thermoplastic polymer matrix based on LDPE or SEVA with a content of 5 to 28% (probably wt.%) VA and a melt index of 3 to 15 (probably g / 10 min), or their mixture and introduced into it an oxygen scavenger based on sodium ascorbate in an amount of from 0.5 to 10 wt. parts per 100 wt. parts of the polymer mixture. In specific examples of this patent (for example, examples 2, 6, 10), a “mixed” oxygen scavenger is used, which contains sodium sulfite in addition to sodium ascorbate (2 parts by weight) - according to domestic nomenclature, it is sodium sulfate [GOST 195-77. Sodium sulfite. Technical conditions - M .: Publishing house of standards, 1996, p.1], and in larger quantities (5 wt. Parts), per 100 wt. parts of the polymer matrix. The composition may also contain a filler, sliding, lubricating and processing additives, pigments, stabilizers, antioxidants and other additives - in the most preferred total amount of less than 3% by weight of the composition not containing PVC. The fusibility of this composition noted in US No. 5075362, which allows molding gaskets from crown melt into crown caps and polypropylene caps of beer bottles, most likely suggests that the composition itself is prepared by mixing its components in a polymer melt.

известно также из научно-технической литературы [М.Е. Позин. Технология минеральных солей (удобрений, пестицидов, промышленных солей, окислов и кислот), ч. I, изд. 4-е, испр. - Л.: Химия, 1974, с. 506]. Полимерная матрица композиции, как отмечается в US №5075362, существенно защищает поглотитель кислорода от влаги в обычных условиях. В то же время, в условиях высокой влажности среды, в которой находится изготовленная из этой композиции уплотнительная прокладка сосуда (бутылки) с пивом или другой водосодержащей жидкостью, реализуется достаточное проникновение влаги в прокладку и, тем самым, удовлетворительная степень кислородопоглощения, что обусловливает увеличение срока хранения напитка. Реакция кислородопоглощения ускоряется в результате нагревания в присутствии влаги, например при пастеризации (при температуре 50-100°C) или стерилизации (при 100-150°C) после наполнения сосуда водосодержащей жидкостью и уплотнения его с использованием прокладки из запатентованной композиции.In the description of US No. 5075362 it is indicated that the oxygen scavenger used in the composition is preferably a reducing agent that reacts with gaseous oxygen in an anionic reaction, which requires the presence of moisture. The case of inorganic sulfites of this reaction in the presence of H ₂ O under the influence of O ₂ air: $$2\mathrm{<figure-callout\; id="3"\; label="S\; O"\; filenames="00000002.png,00000003.png"\; state="\{\{state\}\}">S\; </figure-callout>}{O}_{}^{}{}_3^{2-}+{\mathrm{<figure-callout\; id="2"\; label="O"\; filenames="00000003.png"\; state="\{\{state\}\}">O</figure-callout>}}_2=2S{O}_{\mathrm{four}}^{2-}$$

also known from the scientific and technical literature [M.E. Posin Technology of mineral salts (fertilizers, pesticides, industrial salts, oxides and acids), part I, ed. 4th, rev. - L .: Chemistry, 1974, p. 506]. The polymer matrix of the composition, as noted in US No. 5075362, significantly protects the oxygen scavenger from moisture under normal conditions. At the same time, in conditions of high humidity of the environment in which the gasket of the vessel (bottle) made from this composition is located with beer or other water-containing liquid, sufficient penetration of moisture into the gasket is realized and, thereby, a satisfactory degree of oxygen absorption, which leads to an increase in the period storage of the drink. The oxygen absorption reaction is accelerated by heating in the presence of moisture, for example, during pasteurization (at a temperature of 50-100 ° C) or sterilization (at 100-150 ° C) after filling the vessel with water-containing liquid and sealing it using a gasket from the patented composition.

Only two examples of US No. 5075362 - examples 5 and 6 - allow you to approximately quantify the effectiveness of oxygen absorption of the patented polyolefin gasket sealing composition.

In accordance with example 5, US No. 5075362 prepare thermoplastic compositions for gaskets based on LDPE - a composition containing 2 wt.% Sodium ascorbate, and a composition that does not contain it, and form gaskets into crown caps with which glass bottles containing water. After pasteurization at a temperature of 60 ° C for 20 minutes and storage of the bottles for two months, the oxygen content in their aqueous phase is measured (a method for determining the oxygen concentration in the patent is not indicated). In the case of bottles capped with gaskets without an oxygen scavenger, the oxygen content is 96 μg; in the case of bottles with oxygen-absorbing gaskets, it is zero. Taking the weight of the gasket in the crown plug equal to about 200 mg (it is known [SACMI. Complete lines for the production of crown caps. - www.sacmimoscow.com] that the maximum mass of the crown plug gasket with an inner diameter of 26.75 mm is 0.22 g), indicator kislorodopogloscheniya resulting composition is not less than 0.096 mg O _2/200 mg formulation.

In accordance with example 6 US No. 5075362 prepare a polyethylene composition containing 2% sodium ascorbate, and 5% sodium sulfite and formed from it gaskets. Four such pads with a total weight of 1 g were subjected to a pasteurization-like treatment by immersion in water at a temperature of 60 ° C for 20 minutes, and then were placed in a sealed flask containing 250 ml of water. After three days, the oxygen content in the aqueous phase of the flask is measured and it is established that it has decreased by 70% of the initial value. An approximate calculation assuming that the initial oxygen content in 250 ml of water was 48 μg (based on the fact that in Example 5 of this patent, 96 μg of O _{2 was} contained in 500 ml of H ₂ O, since crown caps with gaskets in this example are likely , standard sealing glass bottles) and taking into account the total weight of gaskets (1 g) to evaluate kislorodopogloscheniya component obtained in example 6, US №5075362 polyolefin composition as a 0.007 mg O _2/200 mg formulation. This rate in the case of the composition of Example 6 (containing besides sodium ascorbate, as in Example 5, also sodium sulfite) is implemented in three days operation the composition while in the case of the composition of Example 5 index 0.096 mg O _2/200 mg of the composition implemented for 20 times longer (2 months).

The disadvantage of the method of obtaining a polyolefin oxygen-absorbing composition for gaskets according to US No. 5075362 is the use for the preparation of this composition as an oxygen scavenger of an expensive substance - sodium ascorbate, and in significant quantities, at least 2 wt. % for all the examples of the patent. In addition, the efficiency of oxygen absorption by this composition is not high enough.

Closest to the claimed method for producing a polyolefin oxygen-absorbing composition for gaskets for the combination of essential features is the method according to CA No. 2782488 [MKI B65D 41/00, publ. 2011, the closest analogue], in accordance with which a PVC-free polymer oxygen-absorbing composition for the manufacture of gaskets in screw caps, in particular in unscrewed crown plugs, is obtained, judging by the use in the formulation of the composition of sliding, lubricating and improving processability additives by melt blending of such polyolefins as ethylene propylene copolymer (BEC) (preferably from 5 to 15%), LDPE (preferably from 10 to 20%) and linear low density polyethylene (LLDPE) (pre titelno from 15 to 25%), as well as thermoplastic elastomer (TPE), particularly a block copolymer of styrene-ethylene-butylene-styrene (SEBS) with a styrene content of 31%, i.e., containing the bulk by weight block of a polyolefin nature (TEP content is preferably from 20 to 30%), medical white (hydrocarbon) oil (preferably from 30 to 40%), thermal stabilizers, optionally pigments and an oxygen scavenger - sodium sulfite (from 1 to 10% , preferably from 4 to 8%) with a small particle size — an average size of preferably less than 12 microns, particularly preferably less than 7 microns. Thus, the characteristic features of the method for producing this composition are the introduction of TEP and medical white oil into the composition of the composition, the exclusion of SEA from the composition and the use of sodium sulfite (Na ₂ SO ₃ ) in the form of very small particles.

In the description of CA No. 2782488 it is emphasized that with a decrease in the particle size of sodium sulfite, accompanied by an increase in the internal (specific) surface of the oxygen scavenger, an increased activity of the agent (Na ₂ SO ₃ ) is realized, since sodium sulfate formed by the reaction (the reaction recorded in general form as: 2Na ₂ SO ₃ + O ₂ = 2Na ₂ SO ₄ ), which flows on the outer surface of the absorber particle, creates a barrier effect for further diffusion of oxygen to its absorber. Thus, by reducing the particle size of Na ₂ SO ₃ (increasing their total surface), it is possible to minimize the required amount of oxygen scavenger.

To determine the efficiency of oxygen absorption in SA No. 2782488 using the method of non-destructive testing, using

which measures the total oxygen concentration in bottles filled with beer analogue (pH value and CO ₂ content), sealed with crown caps with gaskets, respectively, from a patented composition containing sodium sulfite and not containing it. The oxygen-absorbing composition has the following specific composition: BEP - 8%, LDPE - 10%, erucamide (erucic acid amide) - 0.5%, stabilizer - 0.1%, antioxidant - 0.1%, SEBS (31% styrene) - 25%, white oil - 34%, sodium sulfite (anhydrous) - 6%, LLDPE - 16.3% (any characteristics of the (co) polymers used, for example, their density, melt flow rate (MFR) (melt index) and others are not given). In a bottle with a pasteurized beer analogue (conditions not indicated), sealed with a crown plug with a gasket from a composition containing sodium sulfite, the total oxygen content is determined, which is 635 ppm after 94 days, 0.383 ppm after 94 days, and after 181 days - 1.168 ppm less than in a bottle with also a pasteurized beer analog, sealed with a crown plug with a gasket from a composition that does not contain sodium sulfite. An approximate calculation with the assumption that the mass of the beer analog in a standard crown-cork bottle is ~ 500 g and the liner mass is ~ 200 mg leads to the following oxygen absorption efficiency of the composition obtained in accordance with CA No. 2782488: 0.0175 mg O ₂ / 200 mg of the composition to 6 days, 0.1915 mg O _2/200 mg of the composition for 94 days and 0.584 mg O _2/200 mg of composition per 181 hours.

The disadvantage of the method for producing a polyolefin oxygen-absorbing composition for gaskets according to CA No. 2782488 is the use of anhydrous sodium sulfite with a small average particle size (less than 7 microns) as its oxygen scavenger, which requires a special technology for producing such a product and, probably, leads to it rise in price in comparison with "usual" commercial anhydrous sodium sulfite. In addition, the efficiency of oxygen absorption by this composition is not high enough.

The technical result, the achievement of which the claimed method provides, is to use commercial sodium sulfite (a powder with an average particle size of about 70 microns) and to increase the oxygen absorption efficiency of the obtained composition to obtain a polyolefin oxygen-absorbing composition for gaskets.

The specified technical result is achieved due to the fact that in the method for producing a polyolefin oxygen-absorbing composition for gaskets by melt-mixing a mixture of high-pressure polyethylene with a copolymer of ethylene with vinyl acetate with a melt flow rate in the range of 5-10 g / 10 min and a mass fraction of vinyl acetate in the range 10-14%, target additives in a total amount of 0.62-0.80 wt. %, as well as sodium sulfite as an oxygen scavenger, introduced into the composition in an amount of 3.6-6.0 wt. %, sodium sulfite with an average particle size of 70 μm is used and it is introduced into the composition in the form of a granular polymer concentrate obtained from a melt based on a copolymer of ethylene and vinyl acetate with a melt flow rate of 5-15 g / 10 min and a vinyl acetate mass fraction in the range 10-17%, containing 20-40 wt. parts of sodium sulfite 79-59 wt. parts of a copolymer of ethylene with vinyl acetate.

Achieved according to the claimed method, the technical result is unexpected and does not follow from known sources of information. This result is unexpected due to the following.

The use of the claimed method in the composition as a scavenger of oxygen as an oxygen scavenger in the form of a powder with sufficiently large particles with an average size of about 70 microns, an order of magnitude greater than the average particle size of Na ₂ SO ₃ (less than 7 microns) used in the method according to CA No. 2782488 - the closest analogue, it would seem, should have led to lower oxygen absorption efficiency compared to that in the compared method due to the lower specific surface area of larger particles of Na ₂ SO ₃ and greater therefore, the role of the barrier effect for the diffusion of oxygen created by sodium sulfate formed on the outer surface of the Na ₂ SO ₃ particle, as cited above from CA No. 2782488. In fact, the efficiency of oxygen absorption by the composition according to the claimed method is higher than that of the composition obtained by the method - the closest analogue.

It is likely that upon preparation of the composition by mixing all its components in a highly viscous polymer melt, and using sodium sulfate introduced into the composition of the composition as a separate ingredient (in this case, a filler), its particles agglomerate, largely leveling the use of precisely finely dispersed particles filler, as in the case of the method is the closest analogue (CA No. 2782488). Known [Polymeric composite materials: structure, properties, technologies / M.L. Kerber, V.M. Vinogradov, G.S. Golovkin et al .; under the editorship of A.A. Berlin - St. Petersburg: Profession, 2008, p. 74] surface treatment of powdered fillers with surface-active substances (surfactants) in order to reduce the tendency of filler particles to agglomerate. This kind of “treatment” of the surface of Na ₂ SO ₃ particles probably takes place in the preparation of its concentrate based on a matrix of ethylene vinyl acetate copolymer; In this case, SEVA plays the role of a surfactant (it is known [Abramzon A.A. Surfactants: Properties and Applications. - 2nd ed., Revised and additional - L .: Chemistry, 1981, p.241], which is close to CEVA by its chemical nature, thermoplastics, also containing vinyl acetate groups - polyvinyl acetate, is an effective high molecular weight surfactant).

We also consider it probable that when a polymeric composition containing both LDPE (non-polar polymer) and SEA (copolymer containing polar acetate groups) and sodium sulfite (ionic compound) are introduced into the composition, their best distribution is realized as a result of preliminary combination of the polar components - Na ₂ SO ₃ and parts of the used SEVA (or SEVA of close composition and average molecular weight, that is, close PTR) in the composition of their concentrate, the formation of which in the polymer melt may form a “complex” of These components are due to their specific electrostatic interaction. From the composition of such a “complex”, sodium sulfide is more efficiently distributed (and less agglomerated) in the main (co) polymer matrix (LDPE and SEVA) of the composition, since the polymer basis of this “complex” is SEVA, whose macromolecules are built from a significant number of ethylene units, more compatible with LDPE than sodium sulphate.

The number of BA units, as well as the number of ethylene units in the SEVA macromolecules in the composition of the Na ₂ SO ₃ polymer concentrate, should be quite definite, since not only the possible electrostatic interaction of acetate groups with sodium sulfide molecules introduced into the composition in a specific, significant enough ( to ensure effective oxygen absorption), the amount, but also good compatibility of the obtained concentrate as with the main amount of SEVA with a given vinyl acetate content in the whole oliolefinovoy oxygen-scavenging composition, and a LDPE in its composition. To achieve a good distribution of the components in the composition of the composition, in our opinion, the closeness of the values of the MFI (average molecular weight) of its (co) polymer components — SEVA in the composition of the Na ₂ SO ₃ polymer concentrate, the bulk of SEVA in the composition and LDPE in it, is also important. composition. This is important for a good distribution of sodium sulfite, distributed from the obtained polymer concentrate, in which, according to our proposal, it is in the form of a “complex” with SEVA with the corresponding (specified) MFI value.

With a decrease in the content of vinyl acetate in SEVA in the composition of the polymer concentrate of sodium sulfite and a melt flow index of this SEVA below the corresponding declared lower limits (less than 10 wt.% And 5 g / 10 min) and an increase in the content of vinyl acetate in this SEVA and its PTR above the corresponding declared upper limits (above 17 wt.% and 15 g / 10 min) with average of the declared range of sodium sulfite and SEVA in the composition of the polymer concentrate (30 wt. parts of sodium sulfide 69 wt. parts of SEVA) oxygen absorption composition is significantly reduced (see. our Control Examples 8 and 9).

A decrease in the proportion of Na ₂ SO ₃ in the composition of its polymer concentrate below the declared lower limit and a simultaneous increase in the share of SEVA with almost average of the declared values of vinyl acetate (13 wt.%) And MFI (9 g / 10 min) above the declared upper limit (respectively, less than 20 parts by weight of Na ₂ SO ₃ more than 79 parts by weight of SEVA), but while providing the oxygen scavenger (Na ₂ SO ₃ ) content typical of the present method (and the method closest to CA No. 2782488) in the composition ( 6.0 wt.%), Leads to a significant decrease in eff injective oxygen absorption composition (see. our control example 10).

With an increase in the proportion of Na ₂ SO ₃ in the composition of its polymer concentrate above the declared upper limit and a simultaneous decrease in the share of SEVA with practically average of the declared values of vinyl acetate (13 wt.%) And MFI (9 g / 10 min) below the declared lower limit (respectively more than 40 wt. parts of Na ₂ SO ₃ less than 59 wt. parts of SEVA), but while providing the oxygen scavenger content (Na ₂ SO ₃ ) typical of the present method (and the method closest to CA No. 2782488) in the composition (6.0 wt.%), Leads to a significant reduction y efficiency of oxygen absorption by the composition (see our control example 11).

When introducing into the composition of the polyolefin oxygen-absorbing composition for gaskets of sodium sulfate not from the composition of its previously prepared in a melt mode polymer concentrate (polymer concentrate of sodium sulfide is not prepared), but as a result of obtaining a dry mixture of all components of the composition and its subsequent mixing in the mode of polymer melt, significantly (several times) the efficiency of oxygen absorption decreases, and its physicomechanical properties also noticeably decrease (control example 12).

The polyolefin oxygen-absorbing composition for gaskets in accordance with the claimed method is obtained by mixing in the polymer melt components, namely LDPE, SEVA, pre-prepared polymer concentrate of sodium sulfite based on SEVA and the required target additives (antioxidants, sliding and lubricating additives), on mixing equipment - micro-mixer "Brabender" in laboratory conditions and an industrial twin-screw extruder in a production environment. The polymer concentrate Na ₂ SO ₃ used to obtain the composition is prepared on the same micro-mixer in laboratory conditions and a heavy-type mixer, followed by granulation of the mixture on an extrusion unit in an industrial environment.

As raw material components for preparing the inventive method of a polyolefin oxygen-absorbing composition for gaskets, LDPE of the commercial brand 11503-070 (GOST 16337-77), SEVA of the commercial brand Sevilen 11306-075 (TU 6-05-1636-97), and also SEVA of the above are used brand or commercial brand Sevilen 11407-027 (TU 6-05-1636-97) specifically for the preparation of a polymer concentrate of sodium sulfite, commercial sodium sulfite (sodium sulfite) qualification analytical grade (GOST 195-77) and target additives are commercial brand antioxidants, namely Irganox 1010 is the primary phenolic type antioxidant, its chemical name is tetrakis [methylene-3- (3'5) di-tert-butyl-4'- hydroxyphenyl] propionate methane (manufactured by Ciba) and Irgafos 168 is a phosphite-type secondary antioxidant, its chemical name is tris (2,4-di-tert-butylphenyl) phosphite (manufactured by Ciba), a slip additive erucamide (erucic acid amide) ( manufactured by Olefine Organics), a lubricating additive of calcium stearate (TU 6-22-05800165-722-93).

The above GOST 195-77 does not regulate the particle size of the sodium sulfite powder produced in accordance with it. According to our data obtained using an optical microscope of the MBS-9 model, the average particle size of this Na ₂ SO ₃ powder is 70 μm. All examples of the present invention use sodium sulfide in powder form with the indicated average particle size (70 μm).

In the examples of the present invention, a polyolefin oxygen-absorbing composition for gaskets by the claimed method is obtained in laboratory conditions - on a Brabender laboratory micro-mixer with four-blade rotors having a free volume of the mixing chamber of 0.094 l, equipped with electric heating and indication systems for the number of revolutions of the driving rotor, measurement and regulation temperature of the mixing chamber, as well as measuring the temperature of the mixture, with the output of these parameters to a computer monitor; in production conditions - on a twin-screw extruder ZSE-40 MAXX-28D (with a maximum capacity of up to 300 kg / h) manufactured by Leistritz.

The sodium sulfite polymer concentrate used to prepare the composition under laboratory conditions is prepared using a Brabender laboratory micro-mixer, and under production conditions, using a Banbury two-blade mixer heated with silicone oil with a mixing chamber volume of 2.5 l and a productivity of 3 kg / h s subsequent granulation of the mixture on a single-screw extruder "ШМ-90" of the same capacity.

The resulting oxygen-scavenging composition for polyolefin gaskets characterized optimum properties - specific kislorodopogloscheniem within (0,49-0,62) mg O _2/200 mg of the composition and (0,84-1,39) mg O _2/200 mg of the composition, respectively for 6 days and 6 months (181 days) when keeping the gasket models made from the composition in a humid atmosphere, as well as a PTR of about 7.3-8.4 g / 10 min, tensile strength 10.1-10.6 MPa, elongation at break 530-565%.

The characteristics and properties of the obtained polyolefin composition are determined as follows:

1. Melt flow rate (MFR), g / 10 min - at a temperature of 190 ° C and a load of 2.16 kg - according to GOST 11645-73;

2. Tensile strength (σ _p ), MPa, and elongation at break (ε _p ),% - according to GOST 11262-80;

3. Specific kislorodopogloschenie mg O _2/200 mg of the composition - according to the developed within the inventive method a procedure consisting in the following. From the resulting composition, models of sealing gaskets of two-component caps of plastic (polyethylene terephthalate) bottles and crown caps of glass bottles are made. These models are obtained in the form of film-circles with diameters of 26 mm, a thickness of 0.3 mm, and a mass of the order of 0.22-0.23 g as a result of melting the material of the samples of the composition in the corresponding aluminum mold, from the top and bottom laid with a fluorocarbon film (on based on fiberglass and polytetrafluoroethylene) mounted on a steel plate on a hotplate, and subsequent pressing of the molten material in a closed mold on a hand press. Measurement of oxygen absorption by manufactured models of gaskets is carried out on a laboratory installation, the scheme of which is shown in the drawing.

Description of the laboratory installation shown in the drawing.

The installation is a glass flask 1 (actually, as part of the installation of 12 pcs.) With a volume of ~ 300 ml, containing 150 ml of distilled water and 150 ml of air, which usually contains 20.9 vol.% O ₂ before oxygen absorption begins. The flask is closed with a removable steel cap 2 with a thread that is screwed onto the lower steel part 3 with a thread located on the neck of the flask (Fig. 1).

Fixation of the cap 2 and the lower part 3 on the flask 1 is provided by a fluoroplastic ring 4. The tight connection of the cap 2 with the upper edge of the neck of the flask 1 is achieved using a rubber gasket 5 6 mm thick, cut from a rubber plate for vacuum systems (TU 38.105116-81). An aluminum hook 6 is fixed to the gasket 5 with models (5 pcs.) Of gaskets 7 suspended on it. Cover 2 has an opening 8 (10 mm in diameter) for sampling the gas medium from flask 1 when the sampler pierces the rubber gasket 5 (Fig. 2) . After sampling by slightly twisting the lid 2 and compressing, thereby, the rubber gasket 5, the structure is sealed for further sampling.

Periodic sampling (at predetermined time intervals) of a gas medium sample having a volume of 150 ml, flask 1 is carried out using the OXYBABY M + gas analyzer (introduced by WITT-GASETECHNIK GmbH & Co) introduced into the flask of the sampler (sampling needle) 9 KG), having control keys 10 and a display 11 showing the oxygen content (vol.%) In the analyzed sample (figure 3).

Before starting the process of oxygen absorption (and analysis of its effectiveness), the flask 1 with the models of gaskets installed inside it (and with 150 ml of water) is subjected to heating from room temperature to 60 ° C (for 30 min) and then kept at this temperature for 20 min in the thermostat. Then remove the flask from the thermostat; Further, the process of oxygen absorption in the flask during the entire time of the analyzed process proceeds at room temperature.

Specific oxygen absorption by the sample of the obtained composition for a given time is calculated based on the absorption values for this time by the models of gaskets made from this sample of the composition, oxygen according to the gas analyzer, conversion of values in vol.% O ₂ in mg O ₂ taking into account the analyzed volume of the gas phase (150 ml), oxygen density at 20 ° C, equal to 1,429 mg / ml [Physical quantities: Reference book / A.P. Babichev, N.A. Babushkina, A.M. Bratkovsky and others; under the editorship of I.S. Grigoryeva, E.Z. Meilikhova. - M .: Energoatomizdat, 1991, p.99] and the subsequent assignment of the amount of absorbed O ₂ to the entire mass of the taken models of gaskets and then to 200 mg of the composition.

The following examples illustrate the present invention.

Example 1

1. Preparation of a polymer concentrate of sodium sulfite

In a glass beaker with a volume of 0.8 l for 10 min, 55.2 g (69.0 wt.%) Of Sevilen grade 11306-075 SEVA granules with a content of 12 wt.% VA and PTR equal to 6.5 g / 10 min are mixed. 24.0 (30.0 wt.%) Sodium sulfide powder, 0.20 g (0.25 wt.%) Irganox 1010 antioxidant powder, 0.20 g (0.25 wt.%) Irgafos 168 antioxidant powder and 0.40 g (0.50 wt.%) Of erucamide powder.

The resulting dry mixture in an amount of 80.0 g is loaded (for 3 minutes) into a Brabender micro-mixer, previously heated to a temperature of 150 ° C, and mixed in the mode of polymer melt at the same temperature and the speed of rotation of the driving rotor of 60 rpm within 20 minutes After mixing, the prepared sodium sulfate polymer concentrate is discharged from the micro-mixer and crushed to particles with sizes in any direction of 2-5 mm. The prepared polymer concentrate contains 30 wt. parts of sodium sulfite 69 wt. parts of SEVA, its PTR is 6.9 g / 10 min.

Characteristics of the polymer concentrate of sodium sulfite in example 1 and all of the following examples are shown in table 1.

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

In a glass beaker with a volume of 0.8 l for 10 min, 25.0 g (31.2 wt.%) Of HDPE pellets of grade 11503-070 are mixed with a PTR of 6.9 g / 10 min, 38.6 g (48, 3 wt.%) SEVA granules of the Sevilen brand 11306-075 with a content of 12 wt.% VA and PTR equal to 6.5 g / 10 min, 16.0 g (20.0 wt.%) Of sodium sulfite polymer concentrate prepared according to In this example, 0.08 g (0.1 wt.%) Irganox 1010 antioxidant powder, 0.08 g (0.1 wt.%) Irgafos 168 antioxidant powder, 0.16 g (0.2 wt.%) powder erucamide and 0.08 g (0.1 wt.%) of calcium stearate powder.

The resulting dry mixture in an amount of 80.0 g is loaded (within 3 minutes) into a Brabender micro-mixer, preheated to a temperature of 150 ° C, and mixed in the mode of polymer melt at this temperature and the speed of rotation of the driving rotor of 60 rpm for 20 minutes. After mixing, the obtained polyolefin oxygen-absorbing composition is discharged from the micro-mixer and crushed to particles with sizes in any direction of 2-5 mm.

The content of LDPE in the resulting composition is 31.2 wt.%, SEVA - 62.1 wt.% (Of which 13.8 wt.% - SEVA from the composition of the polymer concentrate of sodium sulfite), Na ₂ SO ₃ - 6.0 wt. %, antioxidant Irganox 1010 - 0.15 wt.%, antioxidant Irgafos 168 - 0.15 wt.%, erucamide - 0.30 wt.%, calcium stearate - 0.10 wt.%.

The characteristics and properties of the resulting composition are determined; to determine the specific oxygen absorption of the composition, 5 models of gaskets with a total weight of 1.1562 g are made from it. The resulting composition is characterized by MFI = 7.5 g / 10 min, σ _p = 10.4 MPa, ε _p = 540% and specific oxygen absorption 0, 45 mg O _2/200 mg of the composition, 0.61 mg O _2/200 mg of the composition, 1.14 mg O _2/200 mg of the composition, 1.39 mg O _2/200 mg of the composition, respectively, for 2 days, 6 days, 94 days and 181 days.

The composition, as well as the characteristics and properties of the polyolefin oxygen-absorbing composition for the gaskets of example 1 and all of the following examples are shown in tables 2, 3 and 4, respectively.

Example 2

1. Preparation of a polymer concentrate of sodium sulfite

A sodium sulfate polymer concentrate is prepared under conditions similar to those of Example 1, but an SEVA of the same grade of Sevilen 11306-075 with a content of 10 wt.% VA and a MFI of 5.1 g / 10 min (rounded 5 g / 10 min) is used.

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

A polyolefin oxygen-absorbing composition for gaskets is prepared under conditions similar to the conditions of Example 1, but a polymer concentrate of sodium sulfide prepared according to this example is used, and SEVA of the same grade Sevilen 11306-075 with a content of 10 wt.% VA and an MFR of 5.1 g / 10 min (rounded 5 g / 10 min). The resulting composition contains 6.0 wt.% Na ₂ SO ₃ . The characteristics and properties of the resulting composition are determined; To determine the specific oxygen absorption of the composition, 5 models of gaskets with a total mass of 1.1607 g are made from it.

Example 3

1. Preparation of a polymer concentrate of sodium sulfite

A sodium sulfate polymer concentrate is prepared under conditions similar to those of Example 1, but Sevilen 11407-027 grade SEVA is used with a content of 17 wt.% VA and PTR equal to 14.8 g / 10 min (rounded 15 g / 10 min).

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

A polyolefin oxygen-absorbing composition for gaskets is prepared under conditions similar to those of Example 1, but a sodium sulfite polymer concentrate prepared according to this example is used, and SEVA of the same grade Sevilen 11306-075 with a content of 14 wt.% VA and PTR equal to 9.7 g / 10 min (rounded 10 g / 10 min). The resulting composition contains 6.0 wt.% Na ₂ SO ₃ . The characteristics and properties of the resulting composition are determined; to determine the specific oxygen absorption of the composition, 5 models of gaskets with a total weight of 1.1423 g are made from it.

Example 4

1. Preparation of a polymer concentrate of sodium sulfite

A sodium sulfate polymer concentrate is prepared under conditions similar to those of Example 1, but 63.2 g (79.0 wt.%) Of SEVA pellets of the same grade of Sevilen 11306-075 with a content of 13 wt.% VA and PTR equal to 8.8 are used. g / 10 min (rounded 9 g / 10 min) and 16.0 g (20.0 wt.%) of sodium sulfide powder (antioxidants Irganox 1010 and Irgafos 168, as well as erucamide are used in the same quantities as in example 1 ) The prepared polymer concentrate contains 20 wt. parts of sodium sulfite 79 wt. parts of SEVA.

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

A polyolefin oxygen-absorbing composition for gaskets is prepared under the conditions of Example 1, but using a sodium sulfite polymer concentrate prepared according to this example in an amount of 24.0 g (30.0 wt.%) And SEVA of the same grade Sevilen 11306-075 with a content of 12 wt. % VA and PTR equal to 6.5 g / 10 min, in an amount of 30.6 g (38.3 wt.%) (Use the same LDPE, the same antioxidants, sliding and lubricating additives, and in the same quantities as in example 1). The resulting composition contains 6.0 wt. % Na ₂ SO ₃ . The characteristics and properties of the resulting composition are determined; to determine the specific oxygen absorption of the composition, 5 models of gaskets with a total weight of 1.1598 g are made from it.

Example 5

1. Preparation of a polymer concentrate of sodium sulfite

A polymer sodium sulfate concentrate is prepared under conditions similar to the conditions of example 1, but 47.2 g (59.0 wt.%) Of SEVA pellets of the same brand of Sevilen 11306-075 with a content of 13 wt. %) VA and PTR equal to 8.8 g / 10 min (rounded 9 g / 10 min) and 32.0 g (40 wt.%) Of sodium sulfide powder (antioxidants Irganox 1010 and Irgafos 168, as well as erucamide are used in the same quantities as in example 1). The prepared polymer concentrate contains 40 wt. parts of sodium sulfite 59 wt. parts of SEVA.

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

A polyolefin oxygen-absorbing composition for gaskets was prepared under the conditions of Example 1, but using a polymer concentrate of sodium sulfite prepared according to this example in an amount of 12.0 g (15.0 wt.%) And SEVA of the same grade Sevilen 11306-075 with a content of 12 wt. % VA and PTR equal to 6.5 g / 10 min, in the amount of 42.68 g (53.35 wt.%) (Use the same LDPE, the same antioxidants, sliding and lubricating additives and in the same quantities as in example 1). Received

the composition contains 6.0 wt.% Ns ₂ SO ₃ . The characteristics and properties of the resulting composition are determined; to determine the specific oxygen absorption of the composition, 5 models of gaskets with a total weight of 1.1419 g are made from it.

Example 6 (production)

1. Preparation of a polymer concentrate of sodium sulfite

In a two-blade mixer of the heavy type “Banbury” (heated by silicone oil) with a working (mixing) chamber of 2.5 l in the mode of polymer melt at a temperature of 125-130 ° C for 20 minutes they mix (the speed of the mixer blades is 40 rpm ) 2070 g (69.0 wt.%) SEVA of the Sevilen brand 11306-075 with a content of 12 wt.% VA and PTR equal to 6.5 g / 10 min, 900 g (30.0 wt.%) Sodium sulfite, 7 5 g (0.25 wt.%) Of the antioxidant Irganox 1010; 7.5 g (0.25 wt.%) Of the antioxidant Irgafos 168; and 15 g (0.50 wt.%) Of erucamide. The resulting hot mixture (in the amount of 3.0 kg) is discharged from the mixer and loaded into a ShM-90 single screw extruder and processed into strands at a temperature in the extruder zones of about 130-135 ° C. After cooling, the obtained strands are subjected to cutting on a granulator into granules 2-5 mm in size.

Under conditions strictly identical to the above (by mixing in the melt mode in a heavy mixer of the same components taken in the same quantities, processing the resulting hot mixture in an extruder, etc.), one more batch (3.0 kg) of similar granules is obtained; both batches (6.0 kg) of granules are combined and thoroughly mixed (the indicated amount of the prepared sodium sulfite polymer concentrate is necessary to obtain a production batch of polyolefin oxygen-absorbing composition on an industrial twin-screw extruder). The prepared polymer concentrate contains 30 wt. parts of sodium sulfite 69 wt. parts of SEVA.

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

In a “drunk barrel” type mixer with a volume of 48 l at a temperature of the production room for 5 min, 4.680 kg (31.2 wt.%) Of HDPE pellets of grade 11503-070 are mixed with an MFR equal to 6.9 g / 10 min, 7.245 kg (48.3 wt.%) Of SEVA pellets of the Savilen brand 11306-075 with a content of 12 wt. % VA and PTR equal to 6.5 g / 10 min, and 3,000 (20.0 wt.%) Granules of a polymer concentrate of sodium sulfite, prepared according to this example. Get a mixture of granules with a total mass of 14.925 kg, a component of 99.5 wt. % of the composition 15,000 kg. Under conditions strictly identical to the above, another batch of 14.925 kg of a similar granular mixture is obtained.

Both batches of the obtained dry granule mixture (in a total amount of 29.85 kg) are loaded into the main dispenser of an industrial twin-screw extruder ZSE-40 MAXX-28D (D = 41.4 mm, L / D = 28, where D is the diameter and L is screw length) and is processed at a temperature in the zones of the extruder 150-170ºC, a screw rotation speed of 500 rpm and an extruder productivity of 250 kg / h. During the entire processing time (about 7 min) of this granule mixture from one of the other batchers (the extruder is equipped with four gravimetric batchers operating according to a computer program) 0.15 kg of dry (powder) powder previously prepared in the Anger high-speed mixer is uniformly fed into the extruder cylinder ) a mixture comprising 0.03 kg (0.1 wt.%) of the antioxidant Irganox 1010, 0.03 kg (0.1 wt.%) of the antioxidant Irgafos 168, 0.06 kg (0.2 wt.%) of erucamide and 0.03 kg (0.1 wt.%) Calcium stearate (indicated percentages of target additives respectively they are introduced into the amounts introduced into the resulting composition during processing in an extruder of 29.85 kg of the above granular mixture). As a result of the processing carried out, with the exception of ordinary waste at the beginning and end of the extrusion process, a batch of a polyolefin oxygen-absorbing composition for sealing gaskets weighing 27.2 kg in the form of granules 2-5 mm in size is isolated. The resulting composition contains 6.0 wt.% Na ₂ SO ₃ . The characteristics and properties of the resulting composition are determined; to determine the specific oxygen absorption of the composition, 5 models of gaskets with a total mass of 1.1678 g are made from it.

Example 7 (production)

1. Preparation of a polymer concentrate of sodium sulfite

A polymer concentrate of sodium sulfite is prepared under conditions similar to the conditions of example 6, but receive not two, but one batch (in the amount of 3.0 kg) of the concentrate. The prepared polymer concentrate contains 30 wt. parts of sodium sulfite 69 wt. parts of SEVA.

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

In the same “drunk barrel” type mixer and under the same conditions as in Example 6, 5.3625 kg (42.9 wt.%) Of HDPE pellets of grade 11503-070 with a MFR of 6.9 g / 10 are mixed min, 5.5750 kg (44.6 wt.%) of SEVA pellets of the Savilen brand 11306-075 with a content of 12 wt.% VA and PTR equal to 6.5 g / 10 min. Get a mixture of granules with a total weight of 10.9375 kg, comprising 87.5 wt.% Of the amount of the composition 12,500 kg Under conditions strictly identical to the above, another batch of 10.9375 kg of a similar granular mixture is obtained.

Both batches of the obtained dry granule mixture (in a total amount of 21.875 kg) are loaded into the main dispenser of the same industrial twin-screw extruder, and processed under the same conditions as in Example 6. During the entire processing time (about 6 min) of this granule mixture from 3.0 kg granules of polymer sodium sulfide polymer concentrate prepared according to this example are evenly fed into another extruder barrel, and 0.125 kg dry (powders) previously prepared in an Anger high-speed mixer from another dispenser i) a mixture comprising 0.025 kg (0.1 wt.%) of the antioxidant Irganox 1010, 0.025 kg (0.1 wt.%) of the antioxidant Irgafos 168, 0.050 kg (0.2 wt.%) of erucamide and 0.025 kg (0, 1 wt.%) Calcium stearate (the indicated percentages of the target additives correspond to the amounts introduced into the resulting composition when processing in the extruder 21.875 kg of the above polymer granular mixture and 3.0 kg of granular polymer concentrate of sodium sulfate). As a result of the processing carried out, excluding ordinary waste at the beginning and end of the extrusion process, a batch of polyolefin oxygen-absorbing composition for gaskets weighing 22.4 kg in the form of granules 2-5 mm in size. The resulting composition contains 3.6 wt. % Na ₂ SO ₃ . The characteristics and properties of the resulting composition are determined; to determine the specific oxygen absorption of the composition, 5 models of gaskets with a total mass of 1.1454 g are made from it.

Example 8 (control)

1. Preparation of a polymer concentrate of sodium sulfite. A polymer concentrate of sodium sulfite is prepared under conditions similar to the conditions of example 1, but use SEVA brand Savilen 11205-040 with a content of 8 wt. % VA and PTR equal to 3.6 g / 10 min.

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

A polyolefin oxygen-absorbing composition for gaskets is prepared under conditions similar to the conditions

example 1, but using a polymer concentrate of sodium sulfite prepared according to this example. The resulting composition contains 6.0 wt.% Na ₂ SO ₃ . The characteristics and properties of the resulting composition are determined; to determine the specific oxygen absorption of the composition, 5 models of gaskets with a total mass of 1.1617 g are made from it.

Example 9 (control)

1. Preparation of a polymer concentrate of sodium sulfite

A sodium sulfate polymer concentrate is prepared under conditions similar to those of Example 1, but an SEVA grade of Savilen 11607-040 is used with a content of 20 wt.% VA and PTR equal to 23.4 g / 10 min.

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

A polyolefin oxygen-absorbing composition for gaskets is prepared under conditions similar to the conditions of Example 1, but a polymer sodium sulfate concentrate prepared according to this example is used. The resulting composition contains 6.0 wt.% Na ₂ SO ₃ . The characteristics and properties of the resulting composition are determined; To determine the specific oxygen absorption of the composition, 5 models of gaskets with a total mass of 1.1649 g are made from it.

Example 10 (control)

1. Preparation of a polymer concentrate of sodium sulfite

A sodium sulfate polymer concentrate is prepared under conditions similar to those of Example 1, but 71.2 g (89.0 wt.%) Of SEVA pellets of the same grade of Sevilen 11306-075 with a content of 13 wt.% VA and PTR equal to 8.8 are used g / 10 min (rounded 9 g / 10 min), and 8.0 g (10.0 wt.%) of sodium sulfide powder (antioxidants Irganox 1010 and Irgafos 168, as well as erucamide are used in the same amounts as in the example one). The prepared polymer concentrate contains 10 wt. parts of sodium sulfite 89 wt. parts of SEVA.

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

A polyolefin oxygen-absorbing composition for gaskets is prepared under conditions similar to the conditions of Example 1, but using sodium sulfide polymer concentrate prepared according to this example in an amount of 48.0 g (60.0 wt.%) And SEVA of the same grade Sevilen 11306-075 with a content of 12 wt. % VA and PTR equal to 6.5 g / 10 min, in the amount of 6.6 g (8.3 wt.%) (Use the same LDPE, the same antioxidants, sliding and lubricating additives and in the same quantities as in example 1). The resulting composition contains 6.0 wt. % Na ₂ SO ₃ . The characteristics and properties of the resulting composition are determined; To determine the specific oxygen absorption of the composition, 5 models of gaskets with a total weight of 1.1584 g are made from it.

Example 11 (control)

1. Preparation of a polymer concentrate of sodium sulfite

A polymer concentrate of sodium sulfite is prepared under conditions similar to the conditions of example 1, but using 39.2 g (49.0 wt.%) Of SEVA pellets of the same brand of Sevilen 11306-075 with a content of 13 wt. % In A and PTR equal to 8.8 g / 10 min (rounded 9 g / 10 min), and 40.0 g (50.0 wt.%)) Of sodium sulfide powder (antioxidants Irganox 1010 and Irgafos 168, and erucamide is used in the same quantities as in example 1). The prepared polymer concentrate contains 50 wt. parts of sodium sulfite 49 wt. parts of SEVA.

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

A polyolefin oxygen-absorbing composition for gaskets is prepared under conditions similar to the conditions of example 1, but using a polymer concentrate of sodium sulfite prepared according to this example in the amount of 9.6 g (12.0 wt.%) And SEVA of the same brand Sevilen 11306-075 with a content of 12 wt. % VA and PTR equal to 6.5 g / 10 min, in an amount of 45.0 g (56.3 wt.%) (Use the same LDPE, the same antioxidants, sliding and lubricating additives and in the same quantities as in example 1). The resulting composition contains 6.0 wt. % Na2SO3. The characteristics and properties of the resulting composition are determined; to determine the specific oxygen absorption of the composition, 5 models of gaskets with a total weight of 1.1531 g are made from it.

Example 12 (control)

1. Preparation of a polymer concentrate of sodium sulfite A polymer concentrate of sodium sulfate is not prepared.

2. Obtaining a polyolefin oxygen-absorbing composition for gaskets

A polyolefin oxygen-absorbing composition for gaskets is prepared under conditions similar to the conditions of Example 1, but a pre-prepared dry mixture comprising 25.0 g (31.2 wt.%) Of HDPE pellets of grade 11503-070 with an MFR equal to 6.9 g / 10 min, 49.64 g (62.1 wt.%) Of SEVA granules of the Savilen brand 11306-075 with a content of 12 wt. %) VA and PTR equal to 6.5 g / 10 min, 4.8 g (6.0 wt.%) Of sodium sulfite powder, 0.12 g (0.15 wt.%) Of the antioxidant Irganox 1010, 0.12 g (0.15 wt.%) of the antioxidant Irgafos 168, 0.24 g (0.30 wt.%) of erucamide powder and 0.08 g (0.10 wt.%) of calcium stearate powder. The resulting composition contains 6.0 wt. % Na2SO3. The characteristics and properties of the resulting composition are determined; To determine the specific oxygen absorption of the composition, 5 models of gaskets with a total weight of 1.1660 g are made from it.

As can be seen from the data presented hereinabove in Tables 1-4, the claimed method provides oxygen scavenging polyolefin composition for gaskets with improved efficiency kislorodopogloscheniya, namely in the range 0,49-0,62 mg O _2/200 mg of composition per 6 days and 0,84-1,39 mg O _2/200 mg of composition per 6 months (181 days). In a typical content in the composition of oxygen absorbing agent -. Sodium sulfite, was 6.0 wt%, the efficiency obtained by the claimed method kislorodopogloscheniya composition is 1,08-1,39 mg O _2/200 mg formulation for 181 hours, 1.8 -2,4 times kislorodopogloscheniya efficiency for the same time (0.584 mg O _2/200 mg formulation) oxygen scavenging polyolefin composition for sealing gaskets on the basis of the same oxygen absorber (Na ₂ SO ₃₎ and at the same its content in the composition ( 6.0 wt.%), Gender learn by the method - the closest analogue. Compared with the latter, the polyolefin composition of oxygen-scavenging composition of gaskets obtained by the claimed method also has a much higher "speed" kislorodopogloscheniya - whereas its efficiency kislorodopogloscheniya 6 days is 0,51-0,62 mg O _2/200 mg composition kislorodopogloscheniya efficiency for the same time of the composition obtained by the process - closest analog does not exceed 0.02 mg O _2/200 mg formulation (at a content of 6.0 wt% Na ₂ SO ₃ in the composition of both the compared. Songs).

The polyolefin oxygen-absorbing composition for sealing gaskets obtained by the claimed method is promising for the manufacture of sealing gaskets in closures, in particular in two-component caps made of polymeric materials and in tin crown caps, for hermetically sealing polymeric and glass bottles with food liquids (fruit juices, non-alcoholic drinks, beer), which also provide effective absorption of oxygen from the volume of corked bottles and, thereby, prolonging rock shelf (preserving quality) packed in their food liquids.

Table 1 CHARACTERISTICS OF POLYMER CONCENTRATE OF SODIUM SODIUM * Example No. CMEA indicators The content of Na ₂ SO ₃ , wt. parts The content of SEVA, wt. parts PTR, g / 10 min The content of VA, wt.% PTR, g / 10 min one 12 6.5 thirty 69 6.9 2 10 5.1 thirty 69 5.3 3 17 14.8 thirty 69 16,4 four 13 8.8 twenty 79 9.5 5 13 8.8 40 59 8.2 6 (production) 12 6.5 thirty 69 6.8 7 (production) 12 6.5 thirty 69 6.8 8 (counter) 8 3.6 thirty 69 3.6 9 (counter) twenty 23,4 thirty 69 21.9 10 (count.) 13 8.8 10 89 9.8 11 (counter) 13 8.8 fifty 49 7.3 12 (counter) Sodium sulfate polymer concentrate not prepared * Note: the polymer concentrate of sodium sulfite in all examples also contains 0.25 wt. parts of the antioxidant Irganox 1010, 0.25 wt. parts of the antioxidant Irgafos 168 and 0.50 wt. parts of erucamide.

table 2 COMPOSITION OF POLYOLEFIN OXYGEN-ABSORBING COMPOSITION FOR SEALING GASKETS Example No. LDPE, wt.% SEVA, wt.% Indicators of CMEA mixed with LDPE and concentrate Na ₂ SO ₃ , wt.% The total content of target additives, wt.% from the concentrate Total VA content, wt.% PTR, g / 10 min one 31,2 13.8 62.1 12 6.5 6.0 0.70 2 31,2 13.8 62.1 10 5.1 6.0 0.70 3 31,2 13.8 62.1 fourteen 9.7 6.0 0.70 four 31,2 23.7 62.0 12 6.5 6.0 0.80 5 31,2 8.8 62.15 12 6.5 6.0 0.65 6 (production) 31,2 13.8 62.1 12 6.5 6.0 0.70 7 (production) 42.9 8.28 52.88 12 6.5 3.6 0.62 8 (counter) 31,2 13.8 62.1 12 6.5 6.0 0.70 9 (counter) 31,2 13.8 62.1 12 6.5 6.0 0.70 10 (count.) 31,2 53,4 61.7 12 6.5 6.0 1.10 11 (counter) 31,2 5.88 62.18 12 6.5 6.0 0.62 12 (counter) 31,2 - 62.1 12 6.5 6.0 0.70

Table 3 TYPE AND CONTENT OF TARGET ADDITIVES IN THE COMPOSITION OF POLYOLEFIN OXYGEN-ABSORBING COMPOSITION FOR SEALING GASKETS Example No. Antioxidants, wt.% Erucamide, wt.% Calcium stearate, wt.% The total content, wt.% Irganox 1010 Irgafos 168 one 0.15 0.15 0.30 0.10 0.70 2 0.15 0.15 0.30 0.10 0.70 3 0.15 0.15 0.30 0.10 0.70 four 0.18 0.18 0.34 0.10 0.80 5 0.14 0.14 0.27 0.10 0.65 6 (production) 0.15 0.15 0.30 0.10 0.70 7 (production) 0.13 0.13 0.26 0.10 0.62 8 (counter) 0.15 0.15 0.30 0.10 0.70 9 (counter) 0.15 0.15 0.30 0.10 0.70 10 (count.) 0.25 0.25 0.50 0.10 1.10 11 (counter) 0.13 0.13 0.26 0.10 0.62 12 (counter) 0.15 0.15 0.30 0.10 0.70

Table 4 CHARACTERISTICS AND PROPERTIES OF POLYOLEFIN OXYGEN-ABSORBING COMPOSITION FOR SEALING GASKETS Example No. PTR, g / 10 min σ _p , MPa ε _p ,% Specific kislorodopogloschenie mg O _2/200 mg of the composition in 2 days in 6 days in 94 days For 181 days one 7.5 10,4 540 0.45 0.61 1.14 1.39 2 7.3 10.6 565 0.42 0.57 1,04 1.17 3 8.2 10,2 550 0.42 0.56 1,07 1.30 four 7.8 10.3 555 0.40 0.51 0.96 1,08 5 7.4 10.3 530 0.47 0.62 1.05 1,11 6 (production) 8.4 10.1 535 0.43 0.60 1.09 1.31 7 (production) 8.4 10,2 530 0.38 0.49 0.73 0.84 8 (counter) 7.1 9.8 490 0.29 0.34 0.49 0.56 9 (counter) 9.7 9.1 515 0.28 0.36 0.48 0.53 10 (count.) 8.0 9.3 505 0.25 0.32 0.45 0.53 11 (counter) 7.6 9.6 490 0.29 0.35 0.42 0.50 12 (counter) 7.3 8.4 410 0,07 0.16 0.29 0.37

Claims (1)

A method of obtaining a polyolefin oxygen-absorbing composition for gaskets by melt-mixing a mixture of high-pressure polyethylene with a copolymer of ethylene and vinyl acetate with a melt flow rate of 5-10 g / 10 min and a mass fraction of vinyl acetate in the range of 10-14%, target additives in the total amount 0.62-0.80 wt.%, As well as sodium sulfite as an oxygen scavenger introduced into the composition in an amount of 3.6-6.0 wt.%, Characterized in that sodium sulfite with an average particle size of 70 m is used km and introduce it into the composition in the form of a granular polymer concentrate obtained from a melt based on a copolymer of ethylene with vinyl acetate with a melt flow rate of 5-15 g / 10 min and a vinyl acetate mass fraction in the range of 10-17%, containing 20-40 parts by weight sodium sulfate 79-59 parts by weight copolymer of ethylene with vinyl acetate.

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