CN111303605B

CN111303605B - Polycarbonate composite material and preparation method thereof

Info

Publication number: CN111303605B
Application number: CN202010281449.5A
Authority: CN
Inventors: 熊唯诚; 赵天宝; 茹红光; 杨志; 陈宝书; 茹正伟
Original assignee: Changzhou Bbetter Film Technologies Co ltd
Current assignee: Changzhou Bbetter Film Technologies Co ltd
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2022-11-29
Anticipated expiration: 2040-04-10
Also published as: CN111303605A

Abstract

The invention discloses a polycarbonate composite material and a preparation method thereof, belonging to the technical field of electronic materials. It includes: 80-120 parts of polycarbonate, 10-50 parts of inorganic particles, 20-60 parts of organic toughening agent, 5-30 parts of compatilizer, 2-10 parts of lubricant and 1-10 parts of color master batch. The invention utilizes permeation toughening and rigid particle toughening mechanisms, selects a component system with proper compatibility with the components, and finally forms a novel microcapsule-type core-shell structure with a polycarbonate through segmented polymer phase processing control, the structure can absorb energy through molecular chain movement and special component intramolecular friction when being stressed, thereby improving the toughness and fatigue resistance of the material, when being subjected to cyclic stress, the molecular chain movement generates the intrinsic friction to enable a phase-built micro-area to generate a micro-phase liquid area, the size of the liquid pool is smaller than the critical size, the toughening effect is extremely obvious, cracks can be effectively prevented from sprouting, the accumulated damage of the micro-area in the material is reduced, and the toughness and fatigue resistance of the polycarbonate are greatly improved.

Description

Polycarbonate composite material and preparation method thereof

Technical Field

The invention relates to the technical field of electronic materials, in particular to a polycarbonate composite material and a preparation method thereof.

Background

Polycarbonates (PC for short) are high molecular polymers containing carbonate groups in the molecular chain, and are classified into various types, such as aliphatic, aromatic, aliphatic-aromatic, and the like, depending on the structure of the ester group. Among them, aliphatic and aliphatic-aromatic polycarbonates are limited in their application in engineering plastics due to their low mechanical properties, and the polycarbonates currently used as engineering plastics are mainly bisphenol a type. PC is yellowish, rigid and tough, and has good dimensional stability, creep resistance, heat resistance and electrical insulation. The molecule has a symmetrical structure, is simple and regular, has larger group volume and is difficult to crystallize, and under general molding conditions, PC has an amorphous structure, and the light transmittance can reach 90%. The ester group in the PC chain is a polar group, so that the moisture absorption and hydrolysis are easy. Meanwhile, the PC chain structure is a rigid and tough material with a flexible carbonate chain and a rigid benzene ring structure and mechanical properties, and can meet the impact or cyclic acting force of low stress. However, in a long cyclic stress environment, the polycarbonate product is easy to generate stress cracking, has a large friction coefficient, no self-lubrication, and low wear resistance and fatigue resistance, and thus has limited wide application in the fields of electronic card base materials, 5G transmission carriers, electronic smart cards and the like.

The traditional method for improving the toughness and the fatigue resistance of the polycarbonate is only to add components such as toughening particles, inorganic particles and color master batch into the polycarbonate, the toughening particles, the inorganic particles and the color master batch are not uniformly distributed, when the material is subjected to shear stress, the internal stress concentration of the material is easily caused, so that a large amount of silver lines are generated and developed to cracks, and particularly under the action of cyclic stress, the material is more easily failed, and the use requirement of an intelligent board card cannot be met.

Disclosure of Invention

The invention aims to provide a polycarbonate composite material and a preparation method thereof, and aims to solve the problems that the existing polycarbonate composite material is uneven in component distribution, so that the stress concentration in the material is easily caused, a large number of silver stripes are generated to develop into cracks, and finally the material is easily failed.

The technical scheme for solving the technical problems is as follows:

a polycarbonate composite, comprising: according to the weight portion, 80-120 portions of polycarbonate, 10-50 portions of inorganic particles, 20-60 portions of organic toughening agent, 5-30 portions of compatilizer, 2-10 portions of lubricant and 1-10 portions of color master batch.

Further, in a preferred embodiment of the present invention, the aliphatic polycarbonate comprises: one or more of an aliphatic-aromatic polycarbonate, a bisphenol a type polycarbonate, and a graft-modified polycarbonate.

The group for grafting and modifying the polycarbonate is acrylamide, acrylic acid, ester group, alkyl lithium, alkyl boron, vinyl, maleic anhydride, acrylonitrile, MMA grafting, carbonyl or epoxy anhydride.

Further, in a preferred embodiment of the present invention, the inorganic particles include one or more of talc, mica, whiskers, titanium dioxide, graphene, and carbon nanotubes, and the particle size of the inorganic particles is in a micrometer scale to a nanometer scale, the size distribution of the inorganic particles conforms to a normal distribution, and the kurtosis is less than 3.

Further, in a preferred embodiment of the present invention, the organic toughening agent includes: one or more of MBS, SEBS, ABS, polysiloxane, POE, PE, PS, rubber, PE and polyurethane, and the molecular weight of the polyurethane is more than 10 ten thousand.

Further, in a preferred embodiment of the present invention, the compatibilizer comprises: one or more of silicone, E wax, silane coupling agent, titanate coupling agent, higher fatty acid, fatty acid soap and molybdenum disulfide; the lubricant is: one or more of silicone, polyvinyl alcohol, cellulose acetate, fluoroplastics, fatty acids, fatty acid soaps, paraffin wax, or ethylene glycol.

Further, in a preferred embodiment of the present invention, the color masterbatch comprises: phthalocyanine pigment master batch, azo pigment master batch or quinacridone pigment master batch.

The preparation method of the polycarbonate composite material comprises the following steps:

(1) Drying the components in the proportion for 5-12h at 50-120 ℃ to obtain the dried component with the water content of less than 0.02%;

(2) Uniformly stirring and mixing the dried inorganic particles, the compatilizer and the lubricant in an anchor stirrer at the temperature of 100-120 ℃ at 100-200r/min, and then uniformly mixing at 300-400 r/min;

(3) Uniformly stirring and mixing the mixture obtained in the step (2) and the dried organic toughening agent in a turbine type stirrer at the temperature of 100-120 ℃;

(4) Stirring and mixing the dried polycarbonate and the color master batch uniformly at the temperature of 100-120 ℃;

(5) And (5) stirring and mixing the mixture obtained in the step (3) and the mixture obtained in the step (4) again, conveying the mixture into a double-screw extruder through a conveying device, wherein the temperatures of all sections of the extruder are respectively 150 ℃, 230 ℃, 245 ℃, 250 ℃, 265 ℃ and 250 ℃, the speed of a main machine of the extruder is 300-600r/min, and drying the mixture after extrusion granulation to obtain the polycarbonate composite material.

In the step (1) of the preparation method, all the components are dried firstly, so that the water content is reduced, and the polycarbonate can be prevented from being degraded due to overhigh water content in the subsequent operation of the material.

In the step (2), the compatilizer, the inorganic particles and the lubricant are subjected to non-constant-speed shearing mixing, the size distribution of the adopted inorganic particles conforms to normal distribution, the kurtosis is less than 3, the particles in the range have uniform particle size distribution and are not easy to agglomerate, and the inorganic particles can be well mixed with the compatilizer and the lubricant uniformly, so that the rigidity and the strength of the composite material are improved. The lubricant can further promote the inorganic particles to achieve micro-nano dispersion and form on the particle surface, and simultaneously, the reactive groups (such as anhydride, amino or carboxyl) on the compatilizer react with the reactive groups on the inorganic particle surface to form a primary core-shell structure. The core is mainly a blending shearing mode and the grading progressive increase of the rotating speed, and the three components are controlled to form a primary core-shell structure.

In the anchor stirrer adopted in the step, the shape of the outer edge of the paddle is consistent with that of the inner wall of the stirring tank, only a small gap is reserved between the outer edge of the paddle and the inner wall of the stirring tank, and the viscous reaction products attached to the tank wall or the solid matters accumulated at the tank bottom can be removed, so that a good heat transfer effect is kept.

In the step (3), an organic toughening agent is added, the molecular weight of the adopted organic solubilizing agent is large, a large number of branched structures exist on the molecular structure, and a certain cross-linked but incompletely cross-linked structure also exists, when the organic solubilizing agent is mixed with polyacetate, the branched structures can improve the compatibility with the polyacetate, and meanwhile, the cross-linked structures can also improve the toughness of the polyacetate. Through differential high-speed shearing and stirring, the temperature is controlled, and the toughening agent generates mechanochemical chain scission under the action of shearing force to generate free radicals which form a novel microcapsule type core-shell structure together with the primary core-shell structure. The toughening agent is partially melted by the energy of friction heat generation to form a thin film or be drawn and adhered in the particles formed in the step (2), and the main technical point is that the friction heat generation amount (temperature) can be controlled at a medium speed to just form a characteristic film to wrap the surfaces of the particles formed in the step (2).

In the step, a hinge type stirrer is adopted, and the corresponding stirrer is selected according to the physical properties, the capacity and the stirring purpose of different media, so that the chemical reaction speed is accelerated, and the production efficiency is improved.

In the step (4), the antioxidant and the polycarbonate are stirred and mixed, so that the antioxidant is promoted to be uniformly dispersed on the surface of the polycarbonate, and the degradation degree of the polycarbonate in the thermal processing process is protected. A turbine agitator was used in this step. It is composed of 2-3 propeller blades, and has high working speed, and the peripheral speed of blade outer edge is generally 5-15 m/s. Propeller stirrers mainly cause axial flow, resulting in a large circulation volume.

In step (5), the above components are thoroughly mixed and the polycarbonate is slightly degraded (small amount of molecular chains) by a certain low degree of shear to promote compatibility with other components.

In the steps 2-4 of the preparation method, the specific mixing temperature is selected according to the difference of raw materials in the mixing process, so that the surface reaction of each component is promoted under the temperature condition, the compatibility of each component is promoted, the dispersibility of each component is improved, and the toughness and the fatigue resistance of the final composite material are improved.

The invention considers the microstructure design of the polycarbonate, utilizes permeation toughening and rigid particle toughening mechanisms, selects a component system with proper compatibility, and finally forms a novel microcapsule-type core-shell structure with the polycarbonate ester through the processing control of segmented polymer phase states.

In the preparation process, the compatilizer, the inorganic particles and the lubricant are firstly mixed in a non-constant-speed shearing mode, so that the components are favorably dispersed ideally by means of inter-particle friction, the friction can enable the temperature of the components to rise rapidly to serve as a basic condition for next reaction, and the lubricant can further promote the inorganic particles to achieve micro-nano dispersion and form on the surfaces of the particles, and meanwhile, reactive groups (such as acid anhydride, amino, carboxyl and the like) on the compatilizer react with the reactive groups on the surfaces of the inorganic particles to form a primary core-shell structure. The core of the structure is inorganic particles, and the shell of the structure is a compatilizer and a flexibilizer. The size of the core-shell structure is small enough and is micron-sized, and the shell is very thin and is nanometer-sized in thickness. Generally, the structure is difficult to form by mixing, the structure is in a simple random dispersion form, and the corresponding structure is difficult to form by the inorganic particles and the toughening agent. Then adding a toughening agent, carrying out differential high-speed shearing and stirring, controlling the temperature, and leading the toughening agent to generate mechanochemical chain scission under the action of shearing force to generate free radicals and form a new microcapsule core-shell structure with the primary core-shell structure. And adding polycarbonate and color master batch components, carrying out certain physical blending with the structure, and then carrying out melting, plasticizing, extruding, grain-pumping, grain-cutting and drying by an extruder. The process prepares a novel microcapsule ' type ' core-shell ' structure through hierarchical physical-level dispersion and controllable chemical reaction, and the structure enables the polycarbonate composite material to have the advantages of ultrahigh fatigue resistance and high toughness even when high-content inorganic particles are added. The invention has the following beneficial effects:

1. compared with the prior art, the invention has the technical advancement, and the novel microcapsule core-shell structure can absorb energy through molecular chain movement and characteristic component intramolecular friction when the structure is stressed, so that the toughness and fatigue resistance of the material are improved, when the structure is subjected to cyclic stress, the movement of the molecular chain generates the intramolecular friction to enable a phase micro-area to generate a micro-phase liquid area, the size of the liquid pool is smaller than the critical size, the toughening effect is extremely obvious, cracks can be prevented from growing in a limited manner, and the toughness and fatigue resistance of polycarbonate are greatly improved. The notch impact of the cantilever beam is as high as 50-150KJ/m ² The fatigue resistance can reach 10-40 ten thousand times, the preparation process is efficient and convenient, the product can be widely popularized and applied to the fields of electronic card base materials, 5G transmission carriers, electronic smart cards and the like, and has higher requirements on the toughness and the fatigue resistance.

2. Through constructing a novel 'microcapsule' type 'core-shell' structure, this structure is when receiving stress, accessible molecular chain motion and characteristic component intramolecular friction absorbed energy to improve the toughness and the fatigue resistance of material, when receiving cyclic stress, the motion of molecular chain produces the internal friction and can make the phase put up the micro-zone and produce the microphase liquid district, and this liquid pond size is less than critical dimension, and the effect of toughening is very showing, can limit the crackle to sprout, thereby improves toughness, the fatigue resistance of polycarbonate by a wide margin.

3. The invention prepares a novel polycarbonate composite material with a microstructure by technological innovation and a hierarchical mechanochemical reaction, and the cantilever beam notch impact of the novel polycarbonate composite material is as high as 50-150KJ/m ² The fatigue resistance can reach 10-40 ten thousand times.

4. The preparation process is efficient and convenient, and the product can be widely popularized and applied to the fields of electronic card base materials, 5G transmission carriers, electronic smart cards and the like due to high fatigue resistance and excellent strength and toughness.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a scanning tunneling microscope photograph of a polycarbonate composite obtained in example 1 of the present invention;

FIG. 2 is a scanning tunneling microscope photograph of a polycarbonate composite obtained in comparative example 2 of the present invention.

Detailed Description

The principles and features of this invention are described below in conjunction with embodiments, which are included to explain the invention and not to limit the scope of the invention. The examples, in which specific conditions are not specified, were carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1:

the polycarbonate composite of this example comprises: the coating comprises, by weight, 100 parts of bisphenol A polycarbonate, 20 parts of talcum powder, 20 parts of MBS, 5 parts of silane coupling agent, 2 parts of fatty acid soap and 1 part of phthalocyanine pigment master batch, wherein the particle size of the talcum powder is 1 micrometer.

The preparation method of the polycarbonate composite material of the embodiment comprises the following steps:

(1) Drying the components in the proportion for 5 hours at 50 ℃ to obtain the dried components with the water content of less than 0.02%;

(2) Stirring the dried inorganic particles, the compatilizer and the lubricant in an anchor stirrer at 100 ℃ for 2min at 100r/min, and then stirring for 3min at 300r/min to mix uniformly;

(3) Stirring the mixture obtained in the step (2) and the dried organic toughening agent in a hinge type stirrer at the temperature of 100 ℃ for 5min at a speed of 200r/min, and uniformly stirring and mixing;

(4) Stirring the dried polycarbonate and the color master batch in a turbine type stirrer at 100 ℃ at a speed of 100 revolutions per minute for 5 minutes to mix uniformly;

(5) And (5) stirring and mixing the mixture obtained in the step (3) and the mixture obtained in the step (4) again, conveying the mixture into a double-screw extruder through a conveying device, wherein the temperatures of all sections of the extruder are respectively 150 ℃, 230 ℃, 245 ℃, 250 ℃, 265 ℃ and 250 ℃, the speed of a main machine of the extruder is 300r/min, and performing extrusion granulation and drying treatment to obtain the polycarbonate composite material.

Example 2:

the polycarbonate composite of this example comprises: according to parts by weight, 80 parts of bisphenol A polycarbonate, 30 parts of titanium dioxide, 20 parts of MBS, 20 parts of ABS, 15 parts of silane coupling agent, 6 parts of silicone, 6 parts of paraffin and 5 parts of phthalocyanine pigment master batch, wherein the particle size of the titanium dioxide is 0.1 micron.

(1) Drying the components in the proportion for 8 hours at the temperature of 80 ℃ to obtain the dried components with the water content of less than 0.02%;

(2) Stirring the dried inorganic particles, the compatilizer and the lubricant in an anchor stirrer at the temperature of 110 ℃ for 2min at the speed of 150r/min, and then stirring at the speed of 350r/min for 3min to mix uniformly;

(3) Uniformly mixing the mixture obtained in the step (2) and the dried organic toughening agent in a hinge type stirrer at the temperature of 110 ℃ for 5min by stirring at the speed of 200 r/min;

(4) Stirring the dried polycarbonate and the color master batch in a turbine type stirrer at the temperature of 110 ℃ for 5min at a speed of 100r/min to uniformly mix;

(5) And (4) stirring and mixing the mixture obtained in the step (3) and the mixture obtained in the step (4) again, conveying the mixture into a double-screw extruder through a conveying device, wherein the temperature of each section of the extruder is 150 ℃, 230 ℃, 245 ℃, 250 ℃, 265 ℃ and 250 ℃, the speed of a main machine of the extruder is 450r/min, and performing extrusion granulation and drying treatment to obtain the polycarbonate composite material.

Example 3:

the polycarbonate composite of this example comprises: the coating comprises, by weight, 105 parts of bisphenol A polycarbonate, 15 parts of aliphatic polycarbonate, 39 parts of mica, 1 part of carbon nano tube, 10 parts of polyurethane elastomer, 50 parts of silane coupling agent, 10 parts of silicone, 10 parts of paraffin and 3 parts of phthalocyanine pigment master batch, wherein the mica is 0.1 micrometer, the inner diameter of the carbon nano tube is 1-2 nanometers, the outer diameter is 3-4 nanometers and the length is 50 micrometers.

(1) Drying the components in the proportion for 12h at 120 ℃ to obtain the dried components with the water content of less than 0.02%;

(2) Stirring the dried inorganic particles, the compatilizer and the lubricant in an anchor stirrer at the temperature of 120 ℃ for 2min at 200r/min, and then stirring at the speed of 400r/min for 3min to mix uniformly;

(3) Stirring the dried organic toughening agent in a folding blade type stirrer at the temperature of 120 ℃ for 5min at a speed of 200r/min, and uniformly mixing;

(4) Stirring the dried polycarbonate and the color master batch in a turbine type stirrer at the temperature of 120 ℃ at a speed of 100 revolutions per minute for 5 minutes and uniformly mixing;

(5) And stirring and mixing the mixture again, conveying the mixture into a double-screw extruder through a conveying device, wherein the temperatures of all sections of the extruder are respectively 150 ℃, 230 ℃, 245 ℃, 250 ℃, 265 ℃ and 250 ℃, and the speed of a main extruder is 600r/min, and performing extrusion granulation and drying treatment to obtain the polycarbonate composite material.

Example 4:

the polycarbonate composite of this example comprises: the coating comprises, by weight, 90 parts of bisphenol A polycarbonate, 10 parts of aliphatic polycarbonate, 15 parts of titanium dioxide, 5 parts of mica, 10 parts of rubber, 5 parts of a silane coupling agent, 3 parts of molybdenum disulfide and 3 parts of azo pigment master batches, wherein the particle size of the titanium dioxide is 0.1 micrometer, and the particle size of the mica is 0.1 micrometer.

The preparation method of the polycarbonate composite material of this example is the same as that of example 1.

Comparative example 1

The polycarbonate composite material of the present comparative example includes: the coating comprises, by weight, 100 parts of bisphenol A polycarbonate, 20 parts of talcum powder, 20 parts of MBS and 3 parts of phthalocyanine pigment master batch, wherein the particle size of the talcum powder is 1 micron.

The preparation method of the polycarbonate composite material of this comparative example was identical to the preparation method of example 1.

Comparative example 2

The polycarbonate composite material of the comparative example is identical to that of example 1, except that the preparation method is different, and the preparation method of the comparative example comprises the following steps:

(1) Drying the components in the proportion for 5h at 50 ℃ to obtain the dried components with the water content of less than 0.02%, and then stirring and mixing uniformly at 100 ℃;

(2) And conveying the mixed mixture to a double-screw extruder through a conveying device, wherein the temperatures of all sections of the extruder are respectively 150 ℃, 230 ℃, 245 ℃, 250 ℃, 265 ℃ and 250 ℃, and the speed of a main machine of the extruder is 300r/min, and drying treatment is carried out after extrusion granulation, so as to obtain the polycarbonate composite material.

For the polycarbonate composite materials prepared in examples 1-4 and comparative examples 1-2, the flexural properties, impact properties, tensile strength and fatigue properties were measured according to GB/T9341-2008, GB/T21189-2007 and GB/T1040.2-2006, respectively, and the results were as follows:

TABLE 1 EXAMPLES 1-4 AND COMPARATIVE EXAMPLES 1-2

As can be seen from the above table, the polycarbonate composite material of the present invention has superior strength, impact toughness and high fatigue resistance compared to the comparative example, because the polycarbonate composite material prepared by using the formulation and the preparation method of the present invention has superior strength, impact toughness and high fatigue resistance.

The results of observation under a scanning tunnel microscope with respect to the polycarbonate composite material obtained in example 1 and the polycarbonate composite material obtained in comparative example 2 are shown in FIGS. 1 and 2.

As can be seen from the figure, the polycarbonate composite particles of example 1 are uniformly dispersed without agglomeration; the polycarbonate composite material of comparative example 2 had significant particle agglomeration, which further affected the mechanical properties of the final material.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the scope of the present invention, which is intended to cover any modifications, equivalents, improvements, etc. within the spirit and scope of the present invention.

Claims

1. The polycarbonate composite material is characterized by being prepared from the following components, by weight, 100 parts of bisphenol A polycarbonate, 20 parts of talcum powder, 20 parts of MBS (methyl methacrylate-butadiene-styrene), 5 parts of silane coupling agent, 2 parts of fatty acid soap and 1 part of phthalocyanine pigment master batch, wherein the particle size of the talcum powder is 1 micron; the polycarbonate composite material is prepared by the following steps:

(2) Stirring the dried talcum powder, silane coupling agent and fatty acid soap in an anchor stirrer at 100 ℃ for 2min at 100r/min, and stirring for 3min at 300r/min to mix uniformly;

(3) Stirring the mixture obtained in the step (2) and the dried MBS in a hinge type stirrer at the temperature of 100 ℃ for 5min at a speed of 200r/min, and uniformly mixing;

(4) Stirring the dried bisphenol A polycarbonate and phthalocyanine pigment master batch in a turbine type stirrer at 100 ℃ for 5min at a speed of 100r/min for uniformly mixing;

(5) And (4) stirring and mixing the mixture obtained in the step (3) and the mixture obtained in the step (4) again, conveying the mixture into a double-screw extruder through a conveying device, wherein the temperature of each section of the extruder is 150 ℃, 230 ℃, 245 ℃, 250 ℃, 265 ℃ and 250 ℃, the speed of a main machine of the extruder is 300r/min, and performing extrusion granulation and drying treatment to obtain the polycarbonate composite material.