RU2028337C1 - Polymer composition - Google Patents

Abstract

FIELD: polymer compositions. SUBSTANCE: polymer composition contains, mas.part: fatty aromatic polyimide 100; copper sulfate or copper silicate or their mixture in ratio of from 1:99 to 99:1, and if need be, additionally 0.5-50 mas.part of polycarbonate, polysulfonate or fluorine-containing polymer or copolymer; 0.005-0.2 of heat-resistant filler. Material based on the polymer composition losses 12.5% of its mass after thermal aging at 250 C in the air for 1000 h, tensile strength loss at 200 C for 15 days 2.4%: melt flow index 2.0 at 320 C, pressure 10 kg and holding time of 10 min. EFFECT: higher efficiency. 3 cl, 1 tbl

Description

 The invention relates to the creation of compositions based on aromatic polyimides processed by injection molding.

 The proposed composition can find application in electronic, radio engineering fields of technology, as well as in machine and instrument making.

The composition is intended for the manufacture by injection molding of thin-walled, complex configurations of structural products with good electrical insulation or antifriction properties, operating up to 200 ^° C, in particular for parts of switching devices (single and double pole toggle switches) of "frames", "strips", etc. products.

Known fatty aromatic polyimides- (poly-1,12-dodecamethylene pyromellitimide, etc.) are heat-resistant thermoplastic polymers that have found application as electrical insulating coatings for wires and cables operating up to 150 ^° C [1].

Known compositions based on them, including fillers, have found application as electrical insulating and structural materials operating at temperatures up to 170-200 ^about [2].

A common drawback of aliphatic-aromatic polyamides and compositions based on them is insufficient thermal stability during processing by injection molding and extrusion, which is manifested in the evolution of gaseous products of thermal and thermo-oxidative degradation at temperatures above 320 ^{° C,} resulting in a substandard ( "silver" pores) products.

 The closest in technical essence and effect is a composition with increased thermal stability, consisting of a fatty-aromatic polyimide with an aliphatic chain length of 12 (poly-1,12-dodecamethylene pyromellitimide) and 13 (poly-1,13-tridecamethylene pyromellithimide) methylene groups, and organic phenolic or stabilizers amine type (3) in an amount of 0.5-2 wt.%, as well as a mixture of one of these stabilizers with organic phosphites [4] in an amount of 0.5-4 wt.% of polyimide.

 A common disadvantage of the known compositions based on aromatic polyimide and organic stabilizers is the lack of thermal stability to obtain monolithic (non-porous, without "silver") products, during the operation of which each percent reduction in weight loss due to thermal degradation of the material is extremely important for maintaining the performance of the products.

 The aim of the invention is to increase thermal stability while reducing the viscosity of the melt composition during processing by injection molding while maintaining mechanical properties at the level of known material.

The goal is achieved in that the composition, including aromatic polyimide and a stabilizer, as a stabilizer contains copper sulfate or copper silicate, or a mixture thereof in a ratio (parts by weight) from 1:99 to 99: 1 with the following components, wt. hours:
aromatic polyimide 100
copper sulfate, or sily
copper cat, or mixtures thereof
in a ratio from 1:99 to 99: 1 0.005-0.2
To improve processability by reducing the processing temperature, the composition may further comprise (0.5-50 parts by weight per 100 parts by weight of polyimide) of a thermoplastic heat-resistant polymer selected from the group consisting of polycarbonate, polysulfone, fluorine-containing polymers or copolymers, or mixtures these thermoplastic polymers in any ratio.

 To increase the strength, the composition may additionally contain (0.5-100 parts by weight per 100 parts by weight of polyimide) heat-resistant filler or mixture of fillers in any ratio.

As fatty aromatic polyimides, polyimides obtained by reacting aromatic tetracarboxylic acid dianhydrides (for example, pyromellitic, diphenyl oxide tetracarboxylic acids) such as pyromellitic, diphenyl oxide tetracarboxylic, etc., or mixtures thereof) and aliphatic diamines with at least ₂ carbon atoms between 6 (preferably 1,12-dodecamethylenediamine, 1,13-tridecamethylenediamine, 1,10-decamethylene diamine, 1,6-hexamethylene diamine, etc., or mixtures thereof).

 As thermoplastic heat-resistant polymers can be used polycarbonate, polysulfone, fluorine-containing polymers and copolymers - polytetrafluoroethylene, copolymer, tetrafluoroethylene with hexafluoropropylene, a copolymer of tetrafluoroethylene with vinylidene fluoride, a copolymer, tetrafluoroethylene with ethylene and other copolymers, any copolymers of this type, copolymers.

 As the filler, fiberglass, powdery glass filler, carbon or graphite fiber, graphite, molybdenum disulfide, talc, boron nitride, titanium dioxide, barium sulfate, etc. can be used. or mixtures of these excipients in any ratio.

 Various target additives can be introduced into the composition: lubricants: pigments in an amount of 0.01-1 parts by weight per 100 parts by weight polyimide; flame retardants, thermostable at processing temperatures of fat-aromatic polyimides, in an amount of 1-15 wt.h. per 100 parts by weight polyimide.

Having a lower viscosity composition claimed well processed by injection molding at 320-330 ^{° C,} i.e. at temperatures significantly higher than the processing temperature of polycaprolactam, equal to 170 ^about C.

 The effect of viscosity reduction with the introduction of copper sulfate or copper silicate is characteristic only of aromatic polyimide, which belongs to the class of polyheteroarylenes.

 The proposed compositions are prepared by mixing powdered or granular fatty aromatic polyimide with a stabilizer, followed by homogenization, extrusion and granulation of the composition, or by mixing powdered or granular fatty aromatic polyimide with a stabilizer, polymer additives, fillers, followed by homogenization of the composition by extrusion and granulation.

Glass fibers in the form of glass roving and carbon fibers prior to blending with the polyimide may be pre-impregnated with a solution of polycarbonate or polysulfone in methylene chloride containing 5-20% of polycarbonate or polysulfone), followed by drying the impregnated glass roving or carbon fiber at 150-220 ^{° C} until complete removal of the solvent granulation (cutting) of the dried tow into pieces of 2-15 mm, which are used for mixing with powdered or granular polyimide. Glass roving can also be introduced directly into the polyimide melt during extrusion of the composition.

 The granular filled polyimide material obtained after extrusion can preferably be processed by injection molding, as well as extrusion and injection molding.

PRI me R 1. The composition, wt.h .: Polyimide-based dianhydride
pyromellitic acid and
1,2-dodecamethylene diamine 100
Copper Sulfate 0.005
Polyimide powder mixture with a powder stabilizer was stirred in a ball mill for 30 minutes, dried at 125-10 ^{° C} in a vacuum oven for 12 hr and is extruded on a laboratory extruder at an extrusion temperature of 320-330 ° ^C. The extrudate obtained was used to determine the thermal stability of the composition weight loss after heat aging for 1000 hours at 250 ^{° C} and for oxygen absorption at 270 ^{° C} for 90 min, the melt flow index at 320 ^{° C,} as well as for the manufacture of standard samples injection molded at ^about 320-330 C (type 5 vanes for determining tensile breaking stress).

 The test results are presented in the table.

PRI me R 2. The composition, wt.h .:
Dianhydride-based polyimide
pyromellitic acid and 1,12-dodecamethylene diamine 100 copper copper silicate 0.2
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1.

PRI me R 3. The composition, wt.h .:
Dianhydride-based polyimide
pyromellitic reeds and
diphenyl oxide tetracarbono-
howl of acids and 1,12-dodecamethi-
Lendiamine (granules) 100
A mixture of copper sulfate with silica
copper volume in ratios of 1:99 0.05
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1.

PRI me R 4. The composition, wt.h .:
Dianhydride-based polyimide
reed pyromellitic acid
lots and 1.12-dodecameth-
lendiamine 100
Copper Sulfate 0.05
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1.

PRI me R 5. The composition, wt.h .:
Dianhydride-based polyimide
reed pyromellitic acid
lots and 1,12-dodecamethylene
diamine 100
Copper Sulfate 0.2
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1.

PRI me R 6. The composition, wt.h .:
Diangi-based polyimide
drida pyromellitic
acids and 1,12-dodecamethylene
diamine 100
Copper Silicate 0.005
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1.

PRI me R 7. The composition, wt.h .:
Dianhydride-based polyimide
reed pyromellitic
acids and 1,12-dodecamethylene
diamine 100
Copper Silicate 0.05
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1.

PRI me R 8. Control. The composition, wt.h .: (the amount of stabilizer is outside the declared values)
Dianhydride-based polyimide
reed pyromellitic
acids and 1,12-dodecamethylene
diamine 100
Copper Sulfate 0.003
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1.

 PRI me R 9. Control. The composition, wt.h .: (the amount of stabilizer is outside the declared values).

Dianhydride-based polyimide
reed pyromellitic
acids and 1,12-dodecamethylene
diamine 100
Copper Sulfate 0.25
The preparation of the composition, extrudate, standard samples is produced as in example 1.

PRI me R 10. The composition, wt.h .:
Dianhydride-based polyimide
reed pyromellitic
acids and 1,12-dodecamethylene
diamine (granules) 100
Copper Sulfate 0.05
Polytetrafluoroethylene 0.5
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1.

Extrusion is carried out at 320-350 ^о С, casting of samples - at 315-325 ^о С.

PRI me R 11. The composition, wt.h .:
Diangi-based polyimide
drida pyromellitic
acids and 1,12-dodecamethylene
diamine 100
A mixture of copper sulfate and
copper licate in ratios of 99: 1 0.05
Polysulfone 50.0
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1. Extrusion is carried out at a temperature of 300-320 ^about With, molding the sample at 300-310 ^about C.

PRI me R 12. The composition, wt.h .:
Dianhydride-based polyimide
pyromellitic acid and 1,12-dodecamethylene diamine 100 copper copper silicate 0.05
Powder glass filler 30.00 Titanium dioxide 20.00
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1.

The extrusion temperature of 320-340 ^about With casting at 320-325 ^about C.

 PRI me R 13. The composition, wt.h.

Dianhydride-based polyimide
reed pyromellitic
acids and 1,12-dodecamethylene
diamine 100
Copper Sulfate 0.05
Polycarbonate 5.0
Tetrafluoroethyl copolymer
Lena with vinylidene fluoride 5.0
Carbon fiber 30.0
Graphite 10.0
Barium Sulfate 5.0
Preparation of the extrudate composition, the standard samples and the test produced as in Example 1. The extrusion is conducted at 310-320 ^{° C,} molding - at 305-315 ° ^C.

PRI me R 14. The composition, wt.h .:
Dianhydride-based polyimide
reed pyromellitic
acids and 1,12-dodecamethylene diamine (granules) 100 Copper sulfate 0.05 Polysulfone 20.0 Fiberglass ruble. 55.0 Talc 3.0 Titanium Dioxide 2.0
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1. Extrusion is carried out at 300-315 ^about With, molding - at 310-320 ^about C.

PRI me R 15. The composition, wt.h .:
Dianhydride-based polyimide
reed pyromellitic
acids and 1,10-dodecamethylene diamine 100 Copper silicate 0.05 Polysulfone 50.0 Powder glass filler 97.0 Titanium dioxide 2.0 Boron nitride 1.0
The preparation of the composition, extrudate, standard samples and tests are carried out as in example 1. Extrusion is carried out at 300-320 ^about C, molding - at 310-320 ^about C.

 The properties of the proposed compositions were evaluated by thermal stability, a decrease in the melt flow rate, by a change in the tensile stress at break (operational properties), the appearance of the samples, and the temperature at which the samples were manufactured by injection molding.

The thermal stability of the present compositions consisting of aliphatic-aromatic polyimide, and a stabilizer, determining the loss in mass of the extrudate after extended (to 100 hours) heat aging at 250 ^C in an oven in air as well as oxygen uptake in the static vacuum apparatus at a temperature of 270 ^C and a pressure of oxygen 200 mmHg within 90 minutes

Mass losses under processing conditions were determined at temperatures of 320, 330, and 360 ^о С using an STA-781 thermal analyzer (Stenton Rederost, England).

Test conditions: weight of 20 mg, a heating rate before entering the mode ^-5 ° C / min, argon flow rate of 20 ml / min.

The melt flow of the compositions were determined in a capillary viscometer (IIRT unit) at 320 ^C and a load of 10 kg and heating the composition for 10 minutes.

 The mechanical properties were determined on samples obtained by injection molding. The tests were carried out according to GOST 11262-80.

The thermal stability of compositions comprising aliphatic-aromatic polyimide, a polymer stabilizer additive and a filler, was determined by the decrease in breaking stress under tension after heat aging at ²⁰⁰ ° C for 15 days.

 The data shown in the table show that the introduction of copper sulfate (or copper silicate) in aromatic polyimides in the amount of 0.005-0.2 wt. % increases the thermal stability of the composition - oxygen absorption is reduced and mass loss is reduced during the duration of thermal aging in air; at the same time, the melt flow rate increases (melt viscosity decreases, which facilitates the processing of the composition.

 The optimal concentration of stabilizer is 0.05 wt.%. With the introduction of the specified amount of stabilizer, the mass loss of the composition is reduced by 2 times in comparison with the original polyimide (base object) and 1.6 times in comparison with the prototype; oxygen absorption decreases by 2.0 and 1.5 times, respectively; the melt flow rate increases by 4.5 and 3.0 times, respectively. With the introduction of the proposed stabilizers in the claimed amounts, there is no noticeable change in mechanical properties (tensile stress) in comparison with the base object and the prototype before thermal aging.

Advantageously, the claimed compositions is particularly detected after extended heat aging 15 days of injection of samples from the present composition at a temperature of 200 ^{° C} in air (in an oven). Reduction of tensile breaking stress of samples of the inventive compositions 2.5 and 1.9 is smaller than the base object prototype and after heat aging at ²⁰⁰ ° C, which confirms well the inventive composition improved thermostability, which leads to an increase in operating properties of the composition.

Indicators of weight loss after heat aging in air for 1000 hours at 250 ^C, oxygen absorption at 270 ^{° C} for 30-90 min, the melt flow index, tensile breaking stress and the appearance of the samples after heat aging at ²⁰⁰ ° C for 15 day fully characterize the material in relation to its use as a structural material.

 The mechanical properties were determined on samples obtained by injection molding. The tests were carried out according to GOST 11262-80.

The thermal stability of compositions comprising aliphatic-aromatic polyimide, a stabilizer, a filler and the polymeric additive was determined to reduce failure stress in tension after heat aging at ²⁰⁰ ° C for 15 days.

 The data shown in table 1 show that the introduction of copper sulfate (or copper silicate) in the aromatic polyimide in an amount of 0.005-0.2 wt. % increases the thermal stability of the composition - oxygen absorption is reduced and mass loss is reduced during prolonged thermal aging in air: at the same time, the melt flow rate increases, the melt viscosity decreases, which facilitates the processing of the composition.

 The optimal concentration of stabilizer is 0.05 wt.%. With the introduction of the specified amount of stabilizer, the mass loss of the composition is reduced by 2 times in comparison with the initial polyimide (the base object and 1.6 times in comparison with the prototype, the oxygen absorption decreases by 2.0 and 1.5 times, respectively; the melt flow rate increases by 4.5 and 3.0 times, respectively, with the introduction of the proposed stabilizers in the claimed amounts, there is no noticeable change in the mechanical properties (tensile breaking stress) in comparison with the base object and the prototype before thermal aging.

The advantage of the claimed compositions is particularly detected after prolonged (15 day) heat aging the samples molded from the inventive composition at ²⁰⁰ ° C in the air (in an oven). Reduction of tensile breaking stress of samples of the inventive compositions 2.5 and 1.9 is smaller than the base object prototype and after heat aging at ²⁰⁰ ° C, which confirms well the inventive composition improved thermostability, which leads to an increase in operating properties of the composition.

Indicators of weight loss after heat aging in air for 1000 hours at 250 ^C, oxygen absorption at 270 ^{° C} for 30-90 min, the melt flow index, tensile breaking stress and the appearance of the samples after heat aging at ²⁰⁰ ° C for 15 day fully characterize the material in relation to its use as a structural material.

An additional introduction to the proposed composition of known thermoplastic polymer additives (polycarbonate, polysulfone, fluorine-containing polymers and copolymers) in an amount of from 0.5-50 wt.h. per 100 parts by weight polyimide improves the processability of the composition by reducing the processing temperature at 10-15 ^{° C} while maintaining a high level of heat resistance and strength after heat aging at elevated temperatures (see. Examples 10, 11, 13-15).

 An additional introduction to the composition of the composition of heat-resistant fillers in an amount of 0.5-100 wt.h. per 100 parts by weight polyimide increases the strength level of the claimed composition in 1.5 - 2.0 times while maintaining the level of strength after thermal aging is 3 times greater than the prototype.

 Such compositions are processed by injection molding.

 The introduction of fillers and polymer additives in quantities greater than the claimed, it is possible, but this leads to a deterioration of processability by injection molding, and in quantities less than declared, does not have a practical effect on the properties of the material.

 The introduction of a stabilizer in smaller quantities than the claimed does not provide the necessary thermal stability and a decrease in the viscosity of the melt during processing, and in quantities larger than the stated leads to a deterioration in processability (the melt viscosity of the composition increases).

 The data presented show that only the combination of aromatic polyimide and the proposed stabilizer-copper sulfate and / or copper silicate or mixtures thereof in the claimed range from 0.005 to 0.2 m.h. per 100 parts by weight polyimide, provides the necessary maximum effect on thermal stability and improved processability (lowering the melt viscosity) by injection molding while maintaining tensile strength at the level of the base object and prototype, which ensures the processing of the proposed composition into complex, thin-walled high-quality (without silver) products.

Claims (2)

A POLYMER COMPOSITION containing a fatty aromatic polyimide and a stabilizer, characterized in that it contains copper sulfate or silicate or a mixture thereof in a mass ratio of 1: 99 to 99: 1 in the following ratio, wt.h .:
Fatty Aromatic Polyimide - 100
The specified stabilizer is 0.005 - 0.2
2. The composition according to claim 1, characterized in that it further comprises 0.5 to 50 parts by weight per 100 parts by weight a polyimide of a thermoplastic heat-resistant polymer selected from the group consisting of polycarbonate, polysulfone, fluorine-containing polymer or copolymer, or mixtures of these polymers in any ratio.  3. The composition according to claims 1 and 2, characterized in that it additionally contains 0.5 to 100 parts by weight. per 100 parts by weight polyimide heat-resistant filler or a mixture of fillers.

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