RU2635097C2 - Polymeric composition for medical products manufacture - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: composition contains isotactic polypropylene and/or its copolymers, a modifier and, if necessary, a structurant. At that, the modifier is an organophosphazene and/or an organosiloxane. Dibenzylidene sorbitol or salts of alkali or alkaline-earth metals of dicarboxylic acids were used as the structurant. The total amount of additives is 0.001 to 2 parts by weight per 100 parts by weight of polymer.

EFFECT: obtaining of a material characterized by increased melt strength, improved optical characteristics, and reduced ability for the tribo-effect.

5 cl, 2 tbl, 7 ex

Description

The invention relates to polymeric composite materials based on polypropylene or its copolymers used for the manufacture of medical devices.

It is known that transparency is the most important characteristic of a polymer composite material. The optical characteristics of polyolefins, including polypropylene and its copolymers, strongly depend on the degree of crystallinity, while the crystallites should be small and uniformly distributed in the material.

For example, to obtain a transparent polypropylene-based material, additives are usually added with clarifiers, which, evenly distributed in the polymer melt during subsequent cooling, create crystallization centers, which makes polypropylene more transparent [US patent 8454891 B2].

The best results are achieved using complex formulations containing several types of structure formers.

So, in the patent [US 5856385] a mixture of dibenzylidene sorbitol or its derivatives with amidofunctional compounds is considered as structure-forming agents for polyethylene and polypropylene. With the introduction of these compounds, an increase in transparency is achieved.

In the patent [US patent 5,001,176, NKI 524/48, 1991] describes the use of a mixture of dibenzylidene sorbite in an amount of 0.01-1.0% and cyclodextrin in an amount of 0.01-1.0% as a structurant of polyolefins, such as a copolymer of ethylene with propylene or hexene, butene, polyethylene , polypropylene and others. An example of a copolymer of ethylene with propylene or ethylene with propylene and butene-1 shows an increase in transparency and a decrease in the turbidity of the composition.

The closest in technical essence is the technical solution described in the patent [RU, patent 2174526] (prototype). A mixture of dibenzylidene sorbitol, spatially-hindered phenol and spatially-hindered phosphite with a total amount of 1 wt. part per 100 wt. parts of polypropylene. The resulting material is characterized by a denser structure and improved optical characteristics.

The main common drawback of all of the listed technical solutions, including the prototype, is a change in the structure of sorbitol at high processing temperatures due to the occurrence of hydrolytic processes, which does not allow to achieve the optimal result in terms of transparency. In addition, the introduction of structure formers described in the above technical solutions, on the one hand, increases transparency, and on the other hand, leads to deterioration of mechanical properties and lowers the melt strength, which can lead to cracking of the surface of the material and lower transparency.

Other disadvantages of the prototype include:

- the tendency to accumulate electrostatic charge, which is critical for medical devices, since it causes the buildup of dust and other foreign particles;

- potential deterioration in product quality due to the occurrence of mechanical surface defects during continuous operation of the production cycle, caused by the deposition of the components of the composition on the internal elements of the extruder and / or injection mold.

The present invention is the development of a polymeric material based on polypropylene, characterized by increased melt strength, improved optical characteristics and reduced deposition of low molecular weight components of the composition on the elements of the extruder that do not accumulate electrostatic charge.

The problem is achieved by introducing into the composition based on isotactic polypropylene and / or its copolymers modifier in an amount of 0.001-1 wt. parts consisting of:

1) at least organophosphazene;

2) if necessary, organosiloxane;

and, if necessary, the builder in the amount of 0.01-1 wt. parts that can be used as:

- dibenzylidene sorbitol or its derivative (DBL);

- salts of alkali or alkaline earth metals of dicarboxylic acids (SDK);

or a mixture thereof.

The modifier has a complex effect. On the one hand, it serves as a structuring agent (increase transparency), and on the other hand, it increases the strength of the composition and helps to eliminate the above disadvantages.

Organophosphazene is an individual compound or a mixture of compounds of the general formula:

where x = 1 - 3, y = 1 - 3, z = 1 - 3, and x + y + z = 3,

R ¹ = Cl or O-Ar ¹ , where Ar ¹ is an aromatic hydrocarbon radical containing from 6 to 20 carbon atoms, which may also contain 1 or more halogen atoms (F, Cl or Br);

R ² = Ar ² -X, where Ar ² is an aromatic hydrocarbon radical containing from 6 to 20 carbon atoms, or a derivative thereof, X is an amine, carbonyl, carboxyl, epoxy, glycidyl or methacrylic group.

Organosiloxane is an individual compound or a mixture thereof with the general formula:

where n + m = 3 - 20, R is an aromatic hydrocarbon radical containing 6 carbon atoms. The cis-trans position of the substituents at the phosphorus and silicon atoms does not significantly affect the technical result.

As a base polymer, practically any industrially produced polypropylene or its copolymers with a melt index from 1.0 to 50.0 g / 10 min, containing or not containing traditional well-known additives of thermal stabilizers from the class of phenols and / or phosphites, plasticizers or lubricants, and other target ones, can be used technological additives. It is preferable to use a copolymer of propylene and 0.1-5% ethylene, characterized by a reduced turbidity and yellowness index, in which case the effect of the invention will be maximum.

As DBS, compounds of the general formula can be used:

where R, R ¹ - N aromatic or aliphatic hydrocarbon radical containing from 1 to 20 carbon atoms, their derivatives or their mixture.

In addition, the composite material may contain other known additives, such as fillers, plasticizers, heat stabilizers, dyes, pigments.

When developing the proposed materials used industrially produced compounds:

- polypropylene grade BALEN 01130-15 (OJSC "Ufaorgsintez");

- DBS structurant - a product of Ciba Irgaclear DM;

- SDK structurant - norbornane-dicarboxylic acid disodium salt, product of Milliken Chemical Hyperform HPN-68;

(The use of other builders is also possible)

and specially synthesized compounds as a modifier:

- organophosphazene:

methacrylate-containing carboxyphosphazenes (MKF);

epoxy-containing aryloxyphosphazenes (FEO);

amino-containing aryloxyphosphazenes (ASF);

- organosiloxane.

Methods of obtaining these modifiers are given below.

The invention is illustrated by examples 4-7, in no way limiting the essence of the proposed technical solution, examples 1-3 are given for comparison.

Example 1

The composition for comparison, the composition corresponds to the prototype, in which a mixture of compounds is used as a builder:

- DBS structurant - Ciba Irgaclear D, Irgaclear DM products;

- Spatial-hindered phenol (PFL) structure-forming agent - products of Ciba Irganox 1076, Irganox 1010;

- a spatial-hindered phosphite structurant (PFT) - products from Ciba Irgafos 168, Irgafos 126.

Example 2

Composition for comparison, which includes 100 wt. parts of polypropylene and 0.15 wt. parts of the DBS structure former, which was used as the industrial Irgaclear DM structure former.

Example 3

Composition for comparison, which includes 100 wt. parts of polypropylene and 0.1 wt. part of the SDK structure former, which was used as the industrial Irgaclear DM structure former.

Example 4

In the composition per 100 wt. parts of polypropylene injected 0.3 wt. parts of the organophosphazene modifier, which is used as a mixture of three different aryloxyphosphazenes:

methacrylate-containing carboxyphosphazenes (MKF) 0.1 wt. parts epoxy-containing aryloxyphosphazenes (FEO) 0.1 wt. parts amino-containing aryloxyphosphazenes (ASF) 0.1 wt. parts builder absent

Example 5

In the composition per 100 wt. parts of polypropylene injected 0.5 wt. modifier parts consisting of:

organophosphazene 0.3 wt. parts

which is used as a mixture of three different aryloxyphosphazenes:

methacrylate-containing carboxyphosphazenes (MKF) 0.1 wt. parts epoxy-containing aryloxyphosphazenes (FEO) 0.1 wt. parts amino-containing aryloxyphosphazenes (ASF) 0.1 wt. parts and organosiloxane 0.2 wt. parts builder absent

Example 6

In the composition per 100 wt. parts of polypropylene injected 0.3 wt. parts of the organophosphazene modifier, which is used as a mixture of three different aryloxyphosphazenes:

methacrylate-containing carboxyphosphazenes (MKF) 0.1 wt. parts epoxy-containing aryloxyphosphazenes (FEO) 0.1 wt. parts amino-containing aryloxyphosphazenes (ASF) 0.1 wt. parts Irgaclear DM 0.15 wt. parts

Example 7

In the composition per 100 wt. parts of polypropylene injected 0.5 wt. modifier parts consisting of:

organophosphazene 0.3 wt. parts

which is used as a mixture of three different aryloxyphosphazenes:

methacrylate-containing carboxyphosphazenes (MKF) 0.1 wt. parts epoxy-containing aryloxyphosphazenes (FEO) 0.1 wt. parts amino-containing aryloxyphosphazenes (ASF) 0.1 wt. parts and organosiloxane 0.2 wt. parts SDK structurant 0.1 wt. parts

The composition of the formulations according to the above examples corresponds to the recipe number shown in table 1. The properties of the obtained compositions are shown in table 2.

Modifiers and, if necessary, structure-forming agents can be introduced into polypropylene either at the compounding stage, or at the stage of extrusion molding, or during molding of products. They can be introduced both in the form of a powdery mixture of the starting components, and in the form of a pre-prepared 10-30% concentrate on polypropylene. To obtain a 10-30% concentrate, modifiers and, if necessary, structurants are mixed with polypropylene granules and then extruded. Extrusion is carried out at temperature conditions in the zones 210-240º C.

The introduction of a mixture of additives is carried out at the injection molding stage of polypropylene products. Polypropylene granules are pre-mixed, “dusted” with pre-mixed additives or mixed with a pre-made 10-30% concentrate of additives on polypropylene. The resulting mixture is placed in the hopper of an injection machine for manufacturing products. When pre-mixing additives with the polymer, one should bear in mind the irreversible losses due to the sticking of additives on the mixing equipment and the hopper of the injection machine. Therefore, with the introduction of modifiers and, if necessary, builders at the stage of casting products, it is more efficient to use a concentrate.

Temperature casting 220-260º C. The temperature of the mold 80º C.

To assess the optical and physico-mechanical properties, standard samples are made by injection molding.

* the content of additives is given in mass parts per 100 mass parts of polypropylene and / or its copolymer

* Physical and mechanical tests are carried out according to the following standards:

Tensile strength - according to GOST 11262. Charpy impact strength - according to GOST 4647. Light transmission is evaluated at a wavelength of 425 nm.

The crystallization temperature and thermal effect during melting are estimated by the method of differential scanning calorimetry.

The density of the structure of the molded samples was evaluated by the method of mercury porosimetry according to the indicator "Specific pore volume". This method allows you to evaluate the structure of the sample, quantitatively determine the "density-solidity" of the polymer material. The decrease in porosity, compaction of the structure leads to a decrease in the permeability of gases and other condensing compounds, for example, water vapor, volatile solvents. The use of materials with such properties in the manufacture of vacuum packaging, for example, food products or parts-products that are not resistant to oxidation, is quite effective.

The results shown in table 2 show that, in comparison with the prototype, the material obtained according to the invention of polypropylene is characterized by improved optical characteristics (increase in light transmission to 56.1% against the prototype 46%). The material has a smaller pore size.

In addition, the introduction of a modifier and, if necessary, a structure-forming agent, allows to reduce the working cycle of casting products due to the acceleration of crystallization processes and helps to reduce wear of equipment, and the tendency to deterioration of product quality over time, by reducing the amount of deposits on the elements of the extruder. Composite materials containing the proposed structure-forming agent are characterized by higher physical and mechanical characteristics, melt strength, and do not accumulate a static charge.

All commercial additives offered are hygienic certified and approved for contact with food. Derivatives of organophosphazenes and organosiloxanes are highly stable, completely biologically inert, do not stand out from composite materials and can be used in the manufacture of medical devices.

The method of obtaining methacrylate-containing carboxyphosphazenes (hereinafter referred to as MKF)

MKF was obtained in 2 stages.

Synthesis of hexakis- (n-carboxyphenoxy) cyclotriphosphazene . 4.6 g (0.0054 mol) of hexakis- (n-carbonylphenoxy) cyclotriphosphazene, 3.7 g (0.0234 mol) of potassium permanganate, 1.95 g (0.035 mol) of potassium hydroxide and 15 ml of water were placed in a flat-bottomed flask equipped with a magnetic stirrer. The reaction was carried out at room temperature and stirring for 30 hours. At the end of the process, ethanol was added dropwise to the reaction mixture until the solution became colorless. The MnO ₂ precipitate was filtered off and washed with water. 6 ml of concentrated hydrochloric acid was precipitated from the aqueous solution. The precipitate was filtered off, washed with plenty of water and dried in vacuo at 60 ° C. The yield of product is 94%. Mp = 320 ° C; NMR spectra: δP = 9.2 ppm. (from); δH = 6.9 ppm (d-arom), 7.7 ppm (d-aroma). hexakis- (n-carbonylphenoxy) cyclotriphosphazene was preliminarily prepared by reacting hexachlorocyclotriphosphazene and a 7-fold excess of n-hydroxybenzaldehyde in tetrahydrofuran in the presence of a base at a temperature of 66 ° C for 8 hours.

Synthesis of MKF . In a 20 ml round bottom flask equipped with a magnetic stirrer, 1 g (0.001 mol) of hexakis- (p-carboxyphenoxy) cyclotriphosphazene was loaded, 5 ml of dimethyl sulfoxide was added and stirred until complete dissolution, after which 0.42 ml (0.003 mol) of glycidyl methacrylate was introduced. The synthesis was carried out at 100 ° C for 24 hours in a stream of argon. At the end of the process, the product was poured into 50 ml of distilled water with stirring and left to stand for 3 hours. The mother liquor was separated by decantation. The product is a viscous liquid, dried in vacuum at 40 ° C to constant weight. Yield 88%. NMR spectra: δ _P = 9.2 ppm (from).

The method of obtaining epoxy-containing aryloxyphosphazenes (FEO)

The synthesis of FEO was carried out in 2 stages.

Synthesis of chlorophenol-based oligomers. 5 g (0.0144 mol) of HCF in 70 ml of THF were dissolved in a 3-necked flask with a magnetic stirrer, reflux condenser, calcium chloride tube, and thermometer, after which a solution of 8.67 g of sodium phenolate of chlorphenol (0.0576 mol) in 80 ml of THF was added dropwise. The reaction mixture was stirred for 1 h at room temperature, and then a suspension of 14.4 g (0.0576 mol) of diphenolpropane sodium monophenolate in 70 ml of THF was poured into the flask and the reaction was continued at the boiling point of the solvent for another 12 hours. The progress of the reaction was monitored using ³¹ P NMR spectroscopy. At the end of the process, the mixture was filtered, the solvent was distilled off, and the residue was dried in vacuo for 5 h at 60 ° С. The dry residue was dissolved in chlorobenzene and frozen at -10 ° C for 2 hours to separate the excess diphenylol propane and its phenolate, the mother liquor was filtered off, chlorobenzene was evaporated, and the product was dried in vacuum at 80 ° C for 5 hours. The yield was 13.6 g (85-87% ) The ¹ H NMR spectrum of a chlorine-containing epoxy oligomer (acetone-d6) contains the following signals, ppm: 7.40-7.20 (d, broad, 6H, aromatic ring of the chlorophenol radical); 6.94 (d, 12H, aromatic ring of the DPP radical); 6.84-6.70 (m, broad, 12H, aromatic rings of DPP and chlorophenol radicals); 6.61 (d, 6H, aromatic ring of the DPP radical); 4.31-3.98 (dm, 6H, CH ₂ ); 3.31-3.21 (m, 3H, CH), 2.82-2.60 (dm, 6H, CH _{2 of} the epoxy group); 1.57 (s. 18H, CH ₃ ). ³¹ P NMR (DMSO-d6): s, 8.24 ppm. MS (MALDI-TOF) m / z main: 1056, 1156, 1212 and 1310 [M + H] ⁺ .

Synthesis of FEO . In a 3-necked flask with a reflux condenser and a magnetic stirrer, 10 g (0.0091 mol) of oligomer I (x = 4) in 70 ml of THF were dissolved, after which a solution of 0.73 g (0.0182 mol) of sodium hydroxide was added in 40 ml of ethanol. After 20 minutes, 2.52 g (0.0273 mol) of epichlorohydrin was added dropwise to the reaction mixture and stirred in the cold for 1 h, then it was heated to 50 ° С and stirring continued for another 6 h. After the reaction was completed, the mixture was filtered, the solvents and residual epichlorohydrin were distilled off in vacuo , the residue was dissolved in chloroform and washed with water until neutral. The organic layer was dried with calcium chloride, chloroform was distilled off, and the obtained product was dried in vacuum at 50 ° C for 5 hours. The yield was 9.15 g (83%). The ¹ H NMR spectrum of a chlorine-containing epoxy oligomer (acetone-d6) contains the following signals, ppm: 7.40-7.20 (d, broad, 6H, aromatic ring of the chlorophenol radical); 6.94 (d, 12H, aromatic ring of the DPP radical); 6.84-6.70 (m, broad, 12H, aromatic rings of DPP and chlorophenol radicals); 6.61 (d, 6H, aromatic ring of the DPP radical); 4.31-3.98 (dm, 6H, CH ₂ ); 3.31-3.21 (m, 3H, CH), 2.82-2.60 (dm, 6H, CH _{2 of} the epoxy group); 1.57 (s, 18H, CH ₃ ). ³¹ P NMR (DMSO-d6): s, 8.24 ppm. MS (MALDI-TOF) m / z main: 1056, 1156, 1212 and 1310 [M + H] ⁺ .

The synthesis of amino-containing aryloxyphosphazenes (ASF)

3.0 g (0.0086 mol) HCF, 150 ml THF, 55.3 g (0.2069 mol) cuamine and 12 ml triethylamine were charged into a 250 ml three-necked flask equipped with a mechanical stirrer, thermometer and reflux condenser.

The synthesis was carried out at a temperature of 66 ° C for 24 hours with stirring. At the end of the reaction, the solution was filtered from the resulting salt. The solvent was removed by distillation on a vacuum rotary evaporator. The resulting product was dissolved in chloroform and washed many times, first with acidified water and then with an aqueous solution of sodium carbonate. After washing, the solution in chloroform was dried using magnesium sulfate and then magnesium sulfate was removed by filtration. Chloroform was removed on a vacuum rotary evaporator at a temperature of 50 ° C. The product was dried in a vacuum oven to constant weight.

The method of obtaining organosiloxanes

29.3 g (0.12 mol) of dimethoxyphenylsiloxane, 12.7 g (0.21 mol) of glacial acetic acid, 0.1 were added successively into a three-necked flask equipped with a stirrer, a Dean-Stark trap and a reflux condenser with a calcium chloride tube. g (0.001 mol) of hydrochloric acid and the reaction mixture was stirred at 95 ° C for 10 hours. At the end of the process (the degree of completion was controlled by the amount of liquid released in the Dean-Stark receiver-trap, as well as by the method of sampling the reaction mixture and analyzing their NMR ¹ H spectra) the reaction mixture for Rouge a single neck flask was distilled off low molecular weight products on a vacuum rotary evaporator and finally dried in a vacuum hood.

Claims (13)

1. The polymer composition intended for the manufacture of medical devices containing isotactic polypropylene and / or its copolymer with a melt flow index of from 0.1 to 50 g / 10 min, in an amount of 0.001-1 wt. including modifier and, if necessary, 0.01-1 wt. including the builder per 100 wt. including polypropylene and / or its copolymer, and the modifier is at least one organophosphazene and, if necessary, at least one organosiloxane. 2. The polymer composition according to claim 1, wherein organophosphazene of the general formula (individual compound or mixture of compounds) is used as a modifier:

where x = 1-3, y = 1-3, z = 1-3, with x + y + z = 3; R ^l = Cl or O-Ar ¹ , where Ar ¹ is an aromatic hydrocarbon radical containing from 6 to 20 carbon atoms, which may also contain 1 or more halogen atoms (F, Cl or Br); R ² = Ar ² -X, where Ar ² is an aromatic hydrocarbon radical containing from 6 to 20 carbon atoms, or a derivative thereof, X is an amine, carbonyl, carboxyl, epoxy, glycidyl or methacrylic group. 3. The polymer composition according to p. 1, where as the modifier of organosiloxane use individual compounds or a mixture of the General formula:

where n + m = 3-20, R is an aromatic hydrocarbon radical containing 6 carbon atoms. 4. The polymer composition according to claim 1, where dibenzylidene sorbitol or its derivatives of the general formula are used as a structural agent:

where R, R ¹ - N aromatic or aliphatic hydrocarbon radical containing from 1 to 20 carbon atoms and their derivatives, or a mixture thereof. 5. The polymer composition according to claim 1, wherein alkaline or alkaline earth metal salts of dicarboxylic acids are used as a structurant.