Patent Description:
Polycarbonate (PC) has excellent heat resistance and relatively high impact resistance, and it is widely used in external material fields such as electrical/electronic products and automotive parts. In recent years, wall-thinning of articles molded by resin compositions has received a development, and requirements for improving various physical properties of the articles are continuously increasing.

The polycarbonate may obtain a better rigidity by adding a filler in the polycarbonate, but a ductility will be greatly decreased. In order to improve an impact strength of the materials, the impact strength of the composition is improved by adding an impact modifier in a present technology, but a thermal deformation temperature and a flowing property of product will be influenced. There is also a technology that improves the impact strength by selecting a filler size and a surface treatment, but a range of the improvement is rather small and the effect isn't obvious.

Besides, the filler added will inevitably bring alkaline metal ions. The presence of the alkaline metal ions will not only influence the color of the filler, but also cause rapid decreases in a molding tenacity and a molding use stability of the PC product.

<CIT> describes a polycarbonate composition containing inorganic material with an anisotropic particle geometry and with an iron content of less than about <NUM> ppm.

The present invention found in surprise that in a polycarbonate composite material containing the filler, by adding a trace amount of iron element and copper element, not only a pretreatment for filler powders can be avoided, but also the alkaline ions in a system can be stabilized, so that the polycarbonate composite material prepared has an obviously improved impact strength and an obviously improved molding tenacity, and can also combine the rigidity brought by the filler, with a stable long-term property.

The present invention is defined in and by the appended claims. An object of the present invention is to provide a polycarbonate composite material. By adding a trace amount of iron element and copper element in the polycarbonate composite material, the polycarbonate composite material can be enabled to have a molding tenacity, an impact strength and a flexural modulus that are obviously improved, and also to combine a rigidity brought by a filler, having an excellent molding use stability and color stability.

The present invention is accomplished by the following technical solution:
A polycarbonate composite material, comprises the following components:.

In the polycarbonate composite material, a better rigidity can be obtained by adding a certain amount of fillers. A small amount of metal ions (such as Mg<NUM>+, Al<NUM>+, Cu<NUM>+, Fe<NUM>+) that show an alkalinity are more or less contained in most of the fillers. The presence of these alkaline metal ions will not only influence the color of the fillers, but also cause rapid decreases in the molding tenacity and the molding use stability. In the present invention, controlling a content of copper element in the composite material between <NUM> ppm and <NUM> ppm and controlling a content of iron element in the composite material between <NUM> ppm and <NUM> ppm by adding a small amount of a copper-containing compound and an iron elementary substance or an iron-containing compound into the composite material, and by reducing or avoiding an addition of other copper-containing compounds and other iron-containing compounds, can not only avoid a pretreatment for filler powders, but also stabilize the alkaline ions in the system and reduce a darkened color and a property damage caused by an introduction of a screw or other metal ions. The polycarbonate composite material prepared is enabled to have obviously improved molding tenacity, flexural modulus and impact strength, and also to combine the rigidity brought by the filler and to have excellent molding use stability and excellent color stability. A suitable additive amount of the copper-containing compound is that the content of copper element in the composite material is controlled between <NUM> ppm and <NUM> ppm. A suitable additive amount of the iron elementary substance or the iron-containing compound is that the content of iron element in the composite material is controlled between <NUM> ppm and <NUM> ppm. Since a polycarbonate composite resin is sensitive to metal ions, if the content of iron element and the content of copper element are too high, the composite material will degrade during the production and processing, the properties will be attenuated, and meanwhile the color stability will be decreased.

Based on the total weight of the polycarbonate composite material, the weight content of iron element is <NUM> ppm-<NUM> ppm, preferably <NUM> ppm-<NUM> ppm, and the weight content of copper element is <NUM> ppm-<NUM> ppm, more preferably <NUM> ppm-<NUM> ppm.

Particularly, the iron element is derived from the iron elementary substance or the iron-containing compound, and specifically selected from one or more of ferric chloride, ferrous chloride, ferric nitrate, ferric sulfate, ferrous sulfate, and an iron complex.

Particularly, the copper element is derived from the copper-containing compound, and specifically selected from one or more of cupric chloride, cupric nitrate, cupric sulfate, a copper complex, a cupric ion ionomer and the like.

The polycarbonate is selected from a homo-polycarbonate or a co-polycarbonate that contains a repeating structural unit of carbonate.

The polycarbonate may have a weight-average molecular weight of about <NUM>-<NUM>, and the weight-average molecular weight may be measured by a method well known in the art. A processing flowability and a mechanical property can be combined while the polycarbonate within such range of weight-average molecular serves as a modifying component. If the weight-average molecular weight is less than <NUM>, the modified composition will lose tenacity and can't satisfy a use requirement for product. If the weight-average molecular weight is greater than <NUM>, the processing will be difficult, and a rejection rate and an energy consumption will be increased.

Meanwhile, the polycarbonate has a PDI coefficient ranging from <NUM> to <NUM>. The PDI coefficient is a polydispersity index, which is measured based on a BPA polycarbonate standard gel chromatography method. If a PDI value is greater than or equal to <NUM>, the PDI value represents a uniformity of a polymer molecular chain.

According to ASTM D1238, a melt flow rate of the polycarbonate measured at <NUM> under a load of <NUM> is <NUM>/<NUM>-<NUM>/<NUM>; and a general molding temperature of the composition is <NUM>. At this processing temperature, if the flow rate of the polycarbonate is too low, a viscosity will be too large, and a compatibility of the polycarbonate with other components in the composition will be poor, finally resulting in an increase of instability of the product properties. If the flow rate of the polycarbonate is greater than <NUM>/<NUM>, it indicates a relatively high content of terminal groups of the molecular chains with a high activity, and the mechanical property and the color stability of the product tend to fail due to an intrusion of heat and oxygen during the processing.

The ABS is an acrylonitrile-butadiene-styrene graft copolymer, which is prepared by a method well known in the art, and it may prepared by an emulsion method or a solution method. Specifically, first providing a main polymer chain to prepare a graft copolymer by a polymerization of a conjugated diene such as butadiene or other monomers that can be copolymerized, such as styrene; after the main polymer chain is formed, polymerizing at least one kind of graft monomers, and specifically polymerizing two kinds of graft monomers in the presence of the main polymer chain to obtain the graft copolymer.

The ABS may be obtained by an emulsion polymerization method or a bulk polymerization method.

The ABS copolymer has an average particle size ranging from <NUM> to <NUM>, preferably has an average particle size ranging from <NUM> to <NUM>, and more preferably an average particle size ranging from <NUM> to <NUM>. If the average particle size is greater than <NUM>, dispersion of the ABS in a substrate will be largely reduced; if the average particle size is less than <NUM>, requirements for synthesis processing will be strict, and a yield is relatively low that can't satisfy the requirements for industrialization.

A glass transition temperature of the ABS copolymer is greater than <NUM>, preferably greater than <NUM>, and more preferably greater than <NUM>. While the glass transition temperature is too low, a content of a rubber will be too high and the compatibility will be influenced; while the glass transition temperature is too high, a polarity of the ABS will be high and a surface energy will be large, increasing a difficulty of dispersion.

The filler is a mineral filler, and specifically may be a talcum powder, a wollastonite, a kaolin, a clay, a whisker, a kieselguhr and so on. A volume surface area value of the filler may range from <NUM> to <NUM>.

The filler may be without any surface treatment, or a coating treatment may also be performed on the filler, such as an alkyl surface coating, an epoxy surface treatment, an amide surface treatment, a hydroxyl silicone oil treatment, an alkylsilane treatment, a methoxylsilane treatment, a sulfonate group treatment and the like.

According to different needs of use, the polycarbonate composite material of the present invention may further comprise <NUM>-<NUM> parts by weight of an antioxidant, a light stabilizer, an impact modifier, a fire retardant, a fluorescent brightener, a lubricant, a plasticizer, a flexibilizer, an antistatic agent, a releasing agent, a pigment and the like.

The antioxidant is selected from one or more of a hindered amines antioxidant, a hindered phenols antioxidant and a phosphite esters antioxidant, and specifically one or a mixture of two or more of <NUM>, <NUM>, <NUM>, <NUM> and <NUM>, may be listed.

The flexibilizer is one or a mixture of an EVA type flexibilizer, an EMA type flexibilizer, an ASA type flexibilizer, an AES type flexibilizer, a SAS type flexibilizer, an acrylate flexibilizer and an organic silicon flexibilizer.

The light stabilizer is one or a mixture of a hindered amines absorbent and an ultraviolet absorbent, and specifically one or a mixture of two or more of UV-<NUM>, UV-<NUM>, 770DF, <NUM>, <NUM> and <NUM>, may be listed.

The impact modifier is one or a mixture of two of PTW and a styrene-ethylene/butylene-styrene block copolymer SEBS.

The fire retardant is a phosphate based fire retardant, and specifically may be one or a mixture of two or more of bisphenol A-bis(diphenyl phosphate) BDP, red phosphorus, OP1240 and OP1230.

The fluorescent brightener is one or a mixture of bis(triazinylamino)stilbene and titanium dioxide.

The lubricant is one of or a mixture of two or more of a talcum powder, an ethylene bis stearamide EBS, an erucyl amide, a zinc stearate and a silicon oil.

The plasticizer is one or a mixture of two or more of a glycerinum, a citric acid, a butyl citrate and an epoxidized soybean oil.

The antistatic agent is a permanent antistatic agent, and specifically one or a mixture of two or more of PELESTAT-<NUM>, PELESTAT-<NUM> and SUNNICO ASA-<NUM>, may be listed.

The releasing agent is one or a mixture of two or more of a silicon oil, a paraffin, a white mineral oil and a vaseline.

The pigment is one or a mixture of two or more of a carbon black, a black masterbatch, a titanium oxide, zinc sulfide, a phthalocyanine blue and a fluorescent orange.

A way of acquiring the iron element and the copper element of the present invention, may be directly adding the iron elementary substance or the iron-containing compound and the copper-containing compound during the processing of the polycarbonate composite material. The suitable additive amounts of the iron elementary substance or the iron-containing compound and the copper-containing compound are that the content of iron element in the composite material reaches <NUM> ppm-<NUM> ppm, and the content of copper element in the composite material reaches <NUM> ppm-<NUM> ppm.

The flexural modulus of the polycarbonate composite material of the present invention is greater than <NUM> MPa at the temperature of <NUM> in a sample strip with a size of <NUM> × <NUM> and a length greater than <NUM>.

A notch impact strength of the polycarbonate composite material of the present invention is greater than <NUM> J/m at a temperature of <NUM> by using a <NUM> J pendulum bob in a sample strip with a size of <NUM> × <NUM> × <NUM>.

The molding tenacity of the polycarbonate composite material of the present invention is rated A grade with a thickness of <NUM> and a length and a width of <NUM> × <NUM>.

The polycarbonate composite material of the present invention not only has excellent flexural modulus, impact strength and molding tenacity, but also can combine the rigidity brought by the filler, and has excellent molding use stability and excellent color stability. The polycarbonate composite material of the present invention can be used in thin-wall products having a reinforcement characteristic in fields that require relatively high rigidity such as shells of laptops and housing of household appliances.

Compared with the prior art, the present invention has the following advantageous effects:
it has been surprisingly found that controlling a content of copper element in the composite material between <NUM> ppm and <NUM> ppm and controlling a content of iron element in the composite material between <NUM> ppm and <NUM> ppm by adding a small amount of a copper-containing compound and an iron elementary substance or an iron-containing compound into the composite material, and by reducing or avoiding an addition of other copper-containing compounds and other iron-containing compounds, can not only avoid a pretreatment for the filler powders, but also stabilize the alkaline ions in the system and reduce a darkened color and the property damage caused by an introduction of a screw and other metals. The polycarbonate composite material prepared is enabled to have obviously improved molding tenacity, flexural modulus and impact strength, and also to combine the rigidity brought by the filler, and to have excellent molding use stability and color stability.

The present invention will be further described below by detailed implementations. The following embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited by the following embodiments.

Blending a polycarbonate, the ABS resin, the copper-containing compound and the iron elementary substance, the iron-containing compound, and the filler in a high-speed mixer in accordance with formulas shown in Table <NUM> to obtain a pretreated resin substrate; after weighing the pretreated resin substrate and other aids in proportion, blending via the high-speed mixer or a mixer, with an extruding temperature of <NUM>, cooling by means of water, and pelletizing to obtain a columnar particulate polycarbonate composite material. Ratios of each component and property test results are shown as Table <NUM>.

The polycarbonate composite material was injection molded under an injection temperature of <NUM>, and a mold temperature was <NUM>. A sample strip was a test sample piece with a size of <NUM> × <NUM> and a length greater than <NUM>. The flexural modulus of <NUM> was tested by using a universal testing machine Autogragf made by Shimadzu Corporation, and a speed of a pressure sensing rod of a sensor was <NUM>/min.

The polycarbonate composite material was injection molded under an injection temperature of <NUM>, and a mold temperature was <NUM>. A size of a sample strip was <NUM> × <NUM> × <NUM>, and the notch impact strength of <NUM> was tested by using a <NUM> J pendulum bob.

Particles of the polycarbonate composite material was put into a <NUM> × <NUM> × <NUM> stainless steel box which was cushioned with <NUM> of a teflon film, taken out after being placed in a constant temperature-humidity instrument (the temperature was <NUM>, and the humidity was <NUM>%) for <NUM> hours, then pretreated for <NUM> hours in a vacuum dryer at a predetermined temperature of <NUM>, and performed a flowing test on a melt index instrument of <NUM> applied with a <NUM> weight.

The polycarbonate composite material was injection molded under an injection temperature of <NUM>, and a mold temperature was <NUM>. A size of a sample strip was <NUM> × <NUM> × <NUM>. After being placed at room temperature for <NUM> hours, the sample strip was bent for <NUM> degrees back and forth, and a bending times was recorded once a crack appeared. The polycarbonate composite material was evaluated as A+ grade while the bending times was greater than <NUM>; the polycarbonate composite material was evaluated as A grade while the bending times was less than <NUM> and greater than <NUM>; the polycarbonate composite material was evaluated as A- grade while the bending times was less than <NUM> and greater than <NUM>; the polycarbonate composite material was evaluated as B grade while the bending times was less than <NUM> and greater than <NUM>; the polycarbonate composite material was evaluated as C grade while the bending times was less than <NUM> and greater than <NUM>; and the polycarbonate composite material was evaluated as D grade while the bending times was less than <NUM>.

<NUM> of particles of the polycarbonate composite material were put into a <NUM> cc flask, and <NUM> cc of deionized water was poured into the flask. An acid base titration was performed after the flask was immerged into a <NUM> water bath for <NUM> hours, because the presence of alkaline substances in the polycarbonate composite material may cause a change in the pH of the deionized water. The polycarbonate composite material was evaluated as excellent while the pH ranges from <NUM> to <NUM>; the polycarbonate composite material was evaluated as very good while the pH was greater than <NUM> and less than <NUM>; the polycarbonate composite material was evaluated as good while the pH was greater than <NUM> and less than <NUM>; and the polycarbonate composite material was evaluated as bad while the pH was greater than <NUM>;.

<NUM> of particles of the polycarbonate composite material were accurately weighed in an analytical balance, and were poured into a <NUM> digestion bottle, and then <NUM> of <NUM>% concentrated sulfuric acid were added. The digestion bottle was heated for <NUM> minutes in an iron plate heating instrument at a predetermined temperature of <NUM>, and then <NUM> of <NUM>% nitric acid was added, and the digestion bottle was remained heated for <NUM> minutes. After the particles were totally resolved, they were cooled to room temperature. The above-described liquid was diluted with the deionized water after <NUM> of hydrogen peroxide were added to neutralize an acidity until the pH was <NUM>. The liquid was introduced into an ICP detecting instrument through an injection tube to determine a concentration of the iron element and a concentration of the copper element.

The polycarbonate composite material was injection molded to produce a plate with a thickness of <NUM>, a width of <NUM> and a length of <NUM>. Particularly, a mold temperature was set as <NUM>, and the injection plates were performed a color difference test after being adjusted for <NUM> hours at room temperature of <NUM> and the humidity of <NUM>%; at the same time, a plate with a thickness of <NUM>, a width of <NUM> and a length of <NUM> was produced according to the injection conditions of (<NUM>). Particularly, the mold temperature was set as <NUM>, and the injection plates were performed the color difference test after being adjusted for <NUM> hours at room temperature of <NUM> and the humidity of <NUM>%. A difference between these two test plates (ΔE) was calculated. The smaller the difference, the smaller the variation of a hue.

Claim 1:
A polycarbonate composite material, characterized in that, it comprises the following components:
<NUM>-<NUM> parts by weight of a polycarbonate;
<NUM>-<NUM> parts by weight of an ABS;
<NUM>-<NUM> parts by weight of a filler;
wherein,
based on a total weight of the polycarbonate composite material, a weight content of iron element is <NUM> ppm-<NUM> ppm, and a weight content of copper element is <NUM> ppm-<NUM> ppm;
the polycarbonate has a PDI coefficient ranging from <NUM> to <NUM>;
a melt flow rate of the polycarbonate measured according to ASTM D1238 at <NUM> under a load of <NUM> is <NUM>/<NUM>-<NUM>/<NUM>;
the ABS copolymer has an average particle size ranging from <NUM> to <NUM>;
a glass transition temperature of the ABS copolymer is greater than <NUM>; and
the filler is a mineral filler.