RU2678273C1 - Composition on basis of polycarbonate and basalt fiber, method of manufacturing composition material and composition material produced therewith - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to the chemical industry, in particular to the manufacture of reinforced composite materials with a polymer matrix. Composite material is intended for use in the field of electrical engineering, in the automotive industry, railway transport, in power tools, in household and mobile equipment for the manufacture of body products, as well as in medicine, veterinary medicine and in other areas. Composition based on polycarbonate and basalt fiber includes in wt. %: basalt fiber 4.5–60, fluoroplast 0.05–0.6, cyclic oligomer butylene terephthalate 0.05–0.6, dispersant 0.1–0.60, heat stabilizer 0.1–0.60, polycarbonate – the rest. Method of manufacturing a composite material based on polycarbonate reinforced with basalt fiber and a composite material obtained by this method are also described.

EFFECT: technical result of the invention is to improve the technological properties of the composition while increasing the complex of physical and mechanical properties of the composite material obtained from the claimed composition by the claimed method.

11 cl, 6 tbl

Description

The invention relates to the chemical industry, in particular to the manufacture of reinforced composite materials with a polymer matrix.

Composite material is intended for use in the field of electrical engineering, in the automotive industry, in railway transport, in power tools, in household and mobile appliances for the manufacture of cabinet products, as well as in medicine, veterinary medicine and in other fields.

The widespread use of polycarbonate in various industries is based on the variety of properties of this polymer, the availability of raw materials, a wide range of processing methods at a low cost of the starting material.

However, polycarbonate has a relatively low modulus of elasticity in tension and bending, which limits its use in the manufacture of products of increased strength, for example, body products, etc.

The problem of increasing the tensile and bending elastic modulus is solved by filling the polymer with fibrous reinforcing materials. Composite materials with a polymer matrix filled with various types of fibers, for example: glass, basalt and carbon fibers, are one of the most promising materials, due to the combination of high strength properties and low specific gravity in them.

Basalt fibers are of particular interest as a filler, since the mineral basalt is widespread in Russia. Unlike glass, basalt is a ready-made raw material for fiber production. Due to the wide distribution of the mineral in our country, in recent years, new plants have been opened with modern technologies for the processing of basalt, which helped to reduce the cost of production technology and, as a result, reduce the cost of basalt fibers.

Currently, there is a huge interest in fibers from basalt rocks, which is associated with a number of factors:

- basalt fibers in many respects exceed the properties of glass fibers;

- the raw material base for the production of basalt fibers is practically unlimited;

- Technological advances in recent years have significantly reduced the cost of fiber production;

- basalt fiber has hypoallergenic properties.

The study of the prior art provides the following examples of the use of basalt fiber, mainly discrete, to obtain composite materials for various purposes.

From the description of application US US 2009053960, published February 26, 2009, (IPC: B29C 51/00), a composite material based on a polymer matrix reinforced with basalt fiber is known, as well as a method for its manufacture and an article made from this material. The composite material contains basalt fiber in an amount of 20 to 80 mass. %, thermoplastic polymer matrix - the rest. The matrix of polymeric material may be made of polypropylene, polystyrene, or polycarbonate.

A method of producing a composite material involves mixing a discrete basalt fiber with polymer granules with the addition of solvent, heating the mixture and feeding it onto a perforated conveyor belt with a vacuum to form a non-woven sheet material. Sheets of composite material are formed into blanks to obtain the inner lining of the roof of the passenger compartment.

A disadvantage of the known material is the low strength of the product, since during thermomechanical molding of the product, the reinforcing fibers are damaged.

From the description of Japanese application JP 2011140545, published July 21, 2011 (IPC: C08K 3/36), a composite material based on polycarbonate reinforced with basalt fiber is known using the composition in the following ratio of components to weight. hours:

Aromatic Polycarbonate Resin one hundred Basalt fiber 1-100 Fire retardant component (flame retardant) 0.01-30.

The specified material is intended for the manufacture of thin-walled hull products. A disadvantage of the known material is its low manufacturability with insufficient resistance to ultraviolet radiation and to the effects of other natural factors.

As the closest analogue (prototype) can be selected composite material based on polycarbonate, disclosed in the publication of application US US 2011071246, 03.24.2011. The composition for producing said material contains reinforcing elements, which can be used basalt fiber, preferably 5-30 mm long, in the amount of 1-70 parts, per 100 parts of polycarbonate, which corresponds to the content of the reinforcing element in the range of 1-70 wt. % In addition, the composition may also contain additives in the form of a UV stabilizer and a heat stabilizer (their contents are not indicated).

However, the known composite material has an insufficient level of manufacturability, as well as low strength, resistance to burning and frost resistance.

The description of this patent discloses the use of chopped basalt fiber and a multi-stage production scheme: first, a basalt fiber superconcentrate based on a low molecular weight polycarbonate is prepared, then the resulting superconcentrate is mixed with a high molecular weight polycarbonate to the required basalt fiber content in the composite. The two-stage processing of the composition, in turn, significantly reduces the strength characteristics of the finished material, due to more intense destruction of basalt fiber during processing.

The claimed invention is aimed at solving the problem of increasing the complex of physico-mechanical properties characterizing a composite material while increasing the manufacturability of manufacturing a composite material.

The technical result of the invention is to improve the technological properties of the composition while increasing the complex of physico-mechanical properties of the composite material obtained from the claimed composition by the claimed method.

To solve this problem, a composition based on polycarbonate and basalt fiber, containing a thermal stabilizer, which additionally contains fluoroplastic, a cyclic oligomer of butylene terephthalate and a dispersant in the following ratio, in mass. %:

Basalt fiber 4,5-60 Ftoroplast 0.05-0.6 Cyclic butylene terephthalate oligomer 0.05-0.6 Dispersant 0.1-0.60 Thermal stabilizer 0.1-0.60 Polycarbonate rest.

The composition as a dispersant contains a mixture of paraffin waxes or a mixture of paraffin and montan waxes.

As a reinforcing component of the claimed composition contains a continuous basalt fiber in the form of roving.

The composition may further comprise a light stabilizer (UV stabilizer) in an amount of not more than 1.5 masses. %

The composition may additionally contain in its composition compatibilizer in an amount of not more than 0.05 to 3 mass. %

A method of manufacturing a composite material based on polycarbonate reinforced with basalt fiber is carried out using the composition of the starting ingredients described above. The claimed method includes the preparation of the composition of the starting components and its processing into composite material. In this case, before mixing the starting components, the polycarbonate granules are dried, and then the polycarbonate granules are mixed with additives, including a thermal stabilizer, fluoroplast, a cyclic butylene terephthalate oligomer and a dispersant. The specified mixture may include additional ingredients mentioned above in the composition.

The resulting mixture is fed into an extruder, in which the melt components are melted and homogenized, and the composition is filled with basalt fiber by introducing continuous basalt fiber into the extruder barrel, after which the finished material is removed from the forming head and cooled.

Melting and homogenization of the components of the melt in the extruder is carried out at a temperature of 260-280 ° C.

The finished material is removed from the extruder forming head in the form of strands or rods. Further strands are cut on a granulator. The granules of the obtained composite material can then be processed by casting to obtain, for example, thin-walled body products for the manufacture of devices, mobile phones and other devices.

Depending on the shape of the exit slit of the extruder head, a different configuration may be imparted to the finished composite material.

For example, the finished material can be removed from the forming head of the extruder in the form of a strip, tape or tubular product.

The claimed composite material based on polycarbonate reinforced with basalt fiber can be made as described above using the specified composition in the following ratio of components to mass. %:

Basalt fiber 4,5-60 Ftoroplast 0.05-0.6 Cyclic butylene terephthalate oligomer 0.05-0.6 Dispersant 0.1-0.60 Thermal stabilizer 0.1-0.60 Polycarbonate rest.

As indicated above, the composition for producing a composite material may further include a UV stabilizer in an amount of not more than 1.5 mass. % and compatibilizer in an amount of not more than 0.05 - 3 mass. %

The claimed composition has the following differences from the prototype.

The composition further includes ftoroplast in the amount of 0.05-0.6 wt. % This component is introduced to give the composition resistance to burning. The introduction of fluoroplastic in the indicated amount made it possible to obtain the effect of eliminating dropping during the combustion of the composite material.

In addition, the introduction of fluoroplastic provides the best surface quality, and also improves the frost resistance of the composite material, which increases its strength characteristics at low temperatures. The percentage of fluoroplastic input depends on the content of basalt fiber in the composition and the desired result, for example, with a higher content of basalt fiber, a lower content of fluoroplastic is required to eliminate dropping and more to achieve better results when tested for frost resistance.

The composition further includes a cyclic oligomer of butylene terephthalate in an amount of 0.05-0.6 wt. %

The cyclic butylene terephthalate oligomer was introduced to lower the melt viscosity and to better wet the filler, which is basalt fiber. Since polycarbonate is inherently an amorphous thermoplastic, and filling amorphous polymers usually does not lead to an improvement in strength characteristics, a cyclic butylene terephthalate oligomer, for example, SVT-100, was introduced to improve the interaction of the fiber with the matrix. Due to the extremely low viscosity, the SVT-100 is distributed throughout the composition, wetts the elementary fibers of the basalt filament and crystallizes instantly during cooling, due to this a more ordered structure is formed in amorphous regions and the basalt fiber has greater adhesion to the polymer matrix. Accordingly, with a greater degree of filling, since the melt viscosity in this case increases and the load on the equipment increases, a larger input of this component is necessary to reduce the melt viscosity.

Introduction to the composition of a cyclic oligomer of butylene terephthalate in an amount of 0.05-0.5 wt. % also made it possible to increase the spillability of the composite material into the mold during the manufacture by casting of thin-walled body products with a wall wall thickness of up to 0.1 mm.

The composition further comprises a mixture of paraffin waxes in an amount of 0.1-0.6 wt. %

The mixture of paraffin waxes in this composition is introduced in the specified amount to better disperse all the components in the mixture, respectively, with more additives, more waxes are needed.

The composition further comprises a compatibilizer in an amount of 0.05 -3 wt. % The introduction of the specified component in the claimed amount provides an increase in the adhesion of polycarbonate and basalt fiber in the resulting material. Moreover, with a greater degree of filling of the composition, a greater amount of compatibilizer is necessary.

UV stabilizer (light stabilizer) and a heat stabilizer are introduced into the composition in an amount of 0-1.5 wt. % and 0.1-0.6 wt. %, respectively, to increase the durability of the composite material in various operating conditions.

A UV stabilizer is introduced to prevent degradation of the material when operating the product in open sunlight. The amount of UV stabilizer depends on the region and the conditions of use. So, for example, in the southern latitudes, where the intensity of solar radiation is greater - it is necessary to add more light stabilizer.

The developed composition combines a unique set of functional and technological additives that have a mutual influence in the manufacture of composite material, which provides high manufacturability and an exceptional level of performance in the final product.

The implementation of the claimed method of manufacturing a composite material based on polycarbonate reinforced with basalt fiber, involves before mixing the starting components, the operation of drying granules of polycarbonate. Next, polycarbonate, additives and filler are fed to a weighing device, where the components are weighed according to the recipe of the claimed composition. Next, the polycarbonate granules and additives fall into the mixer, where it is mixed until a homogeneous mixture.

At the next stage, from the mixer, the mixture, including polycarbonate granules and additives, is fed by a screw feeder into the hopper of the extruder, and then enters the body of the extruder, in which the melt is mixed and homogenized at a temperature of 250-280 ° C. It should be noted that the temperature is heterogeneous in the zones of the extruder body and depends on the resulting composition of the material. Basalt roving is fed directly into the material cylinder of the extruder in an amount according to the formulation of the composition.

The finished material leaves the forming head, preferably in the form of strands, is cooled in a cooling bath and enters the granulator.

The possibility of obtaining a composite material using the claimed composition is illustrated by the following examples 1-4.

Example 1

A polymer composition based on polycarbonate and basalt fiber was obtained according to the following scheme.

From the storage warehouse, polycarbonate in granules of the RS-007 grade was loaded into heated silos to dry the material. Fluoroplast F-4MB grade, cyclic oligomer butylene terephthalate, grade SVT-100, heat stabilizer, grade B900, and a mixture of paraffin waxes, grade SPC 750U, were used as additives. Additionally used the additive of a UV stabilizer brand Carbomix MD.

Basalt fiber was used as a roving. As the basalt fiber used continuous basalt fiber brand NRB17-4800-KV-42A.

Next, polycarbonate and additives were fed to a weighing device, where portions of each component were weighed to formulate the composition in the following mass ratio. %:

polycarbonate RS-007 65,037 ftoroplast F-4MB 0.133 cyclic oligomer butylene terephthalate SVT-100 0.0665 UV stabilizer Carbomix MD 0.665 thermostabilizer B900 0.3325 basalt fiber NRB17-4800-KV-42A 33,50 paraffin wax mixture SPC 750U 0.266

Next, samples of polycarbonate and additives were fed into the mixer. At the next stage, from the mixer, the mixture of polycarbonate and additives was fed into the hopper of the extruder, from which the mixture is dosed into the material cylinder of the extruder, where the melt melts, mixes and homogenizes at a temperature in the range of 260-280 ° С. The composition is filled with basalt fiber directly in the material cylinder of the extruder by introducing continuous basalt roving into it.

The finished composite material based on polycarbonate reinforced with continuous basalt fiber leaves the opening of the forming head in the form of strands, then it is cooled in a cooling bath and enters the granulator.

Products such as various cases and parts for electrical devices that are traditionally made of glass-filled polyamide can be made from this material. However, products obtained using the claimed invention will have several advantages, for example, increased values of dielectric characteristics (material resistance is higher) and will be non-combustible, with low water absorption, as well as stability of properties at high humidity, and high shockproof characteristics. In addition, products used in road construction can be manufactured, for example, such as sheets for noise screens, the advantages are non-combustible, high resistance to shock loads, and also higher noise insulation properties. And other products that are subject to increased requirements for strength and dielectric indicators.

Table 1 shows the composition used to make a composite material based on polycarbonate reinforced with continuous basalt fiber, and table 2 presents the properties of a composite material based on polycarbonate reinforced with continuous basalt fiber.

Examples 2-4.

Examples 2-4 were carried out according to the same technology as example 1.

Table 1 shows the composition used for the manufacture of composite material based on polycarbonate reinforced with continuous basalt fiber, obtained according to examples 2-4, and tables 3-5 show the properties of the composite material based on polycarbonate reinforced with continuous basalt fiber, obtained according to examples 2-4. Moreover, in example 3, as an additional additive, a XERAN M63 brand compatibilizer was introduced into the composition, which is a maleized styrene polymer with an average molecular weight and high reactivity. (Instead, it is possible to use a similar compatibilizer of the brand - XERAN M19 in the same amount).

As can be seen from the presented examples, the developed materials differ in the following set of characteristics:

- An insignificant level of water absorption, which, by comparison, is an order of magnitude lower than that of glass-filled polyamide 6;

- The material is not combustible and corresponds to the flammability category V0 according to UL94;

- The highest level of rigidity in combination with high resistance to shock loads, including at low and high temperatures;

- The temperature interval of long-term operation is from -60 to + 135 ° C, short-term heating to + 155 ° C is allowed without applying a load;

- Excellent formability;

- High dimensional stability, which allows the use of this material in precision casting;

- Excellent chemical resistance, especially in acidic environments and salt solutions, which in turn allows the use of this material in aggressive environments;

- High resistance to aging under the influence of UV and heat;

- The developed materials have increased vibration resistance;

- The temperature range for processing these materials does not practically differ from the interval for unfilled polycarbonate and ranges from 260 to 300 ° C.

A comparison of the strength properties of a composite material based on basalt fiber reinforced polycarbonate, obtained according to the claimed invention, with the properties of the composite material presented in the examples of the invention selected for the prototype (US 2011071246), shows the following.

According to the claimed invention, bending stress at maximum load when the content of basalt fiber in the composite material is from 20 to 30 wt. % is 113-189 MPa, that is, it is much higher than in the examples of the prototype, where the bending stress at maximum load with the same content of the reinforcing component was 54-110 MPa, from which we can conclude that such physical and mechanical characteristics, as the elastic modulus and tensile strength in the material made using the claimed invention will also be significantly higher than in the prototype. A comparison of the properties is presented in table 6.

That is, we can conclude that with the introduction of a complex of additives included in the composition of the claimed composition, the strength characteristics of the composite material are significantly higher at the same basalt fiber content as in the prototype.

In addition, judging by the examples from the prototype, no antipyretic components were introduced into the composition that would inhibit the material’s ability to burn. Therefore, we can conclude that the material from the prototype is combustible, in contrast to the material according to the invention.

In comparison with the prototype, the problem of increasing the complex of physical and mechanical properties characterizing strength, resistance to burning and frost resistance has been solved.

Properties of the composite material according to example No. 2:

Properties of the composite material according to example No. 3:

The properties of the composite material according to example No. 4:

Comparison of the properties of the composite material according to the claimed invention and

prototype

Claims (13)

1. A composition based on polycarbonate and basalt fiber, containing a thermal stabilizer, characterized in that it contains continuous basalt fiber as a basalt fiber and additionally contains fluoroplastic, a cyclic butylene terephthalate oligomer and a dispersant in the following ratio of components, wt. %: Basalt fiber 4,5-60 Ftoroplast 0.05-0.6 Cyclic butylene terephthalate oligomer 0.05 - 0.6 Dispersant 0.1-0.60 Thermal stabilizer 0.1-0.60 Polycarbonate rest 2. The composition according to p. 1, characterized in that as a dispersant it contains a mixture of paraffin waxes. 3. The composition according to p. 1, characterized in that as a dispersant it contains a mixture of paraffin and montan waxes. 4. The composition according to p. 1, characterized in that as a reinforcing component it contains a continuous basalt fiber in the form of a roving. 5. The composition according to p. 1, characterized in that it further comprises a UV stabilizer in an amount of not more than 1.5 wt. % 6. The composition according to p. 1, characterized in that it further comprises a compatibilizer in an amount of not more than 3.0 wt. % 7. A method of manufacturing a composite material based on polycarbonate reinforced with basalt fiber, comprising composing the composition of the starting components and processing it into a composite material, characterized in that before mixing the starting components, the polycarbonate is dried, then the polycarbonate is mixed with additives including a thermal stabilizer, fluoroplastic , a cyclic oligomer of butylene terephthalate and a dispersant, the resulting mixture is fed to an extruder, in which melt and homogenization of the components of the melt at a temperature of 260-280 ° C, and filling with basalt fiber is carried out by introducing a continuous basalt fiber into the material cylinder of the extruder, after which the finished material is removed from the forming head and cooled. 8. The method according to p. 7, characterized in that the finished material is removed from the forming head of the extruder in the form of strands or rods. 9. The method according to p. 8, characterized in that the finished material is sent to a granulator. 10. The method according to p. 7, characterized in that the finished material is removed from the forming head of the extruder in the form of a strip or tape. 11. A composite material based on polycarbonate reinforced with basalt fiber, characterized in that it is made using the composition in the following ratio of components, wt. %: Basalt fiber 4,5-60 Ftoroplast 0.05-0.6 Cyclic butylene terephthalate oligomer 0.05 - 0.6 Dispersant 0.1-0.60 Thermal stabilizer 0.1-0.60 Polycarbonate rest