WO2016188475A1

WO2016188475A1 - Polycarbonate composition and preparation method therefor

Info

Publication number: WO2016188475A1
Application number: PCT/CN2016/083624
Authority: WO
Inventors: 岑茵; 何继辉; 孙东海; 佟伟; 谢湘; 郭唐华
Original assignee: 金发科技股份有限公司
Priority date: 2015-05-27
Filing date: 2016-05-27
Publication date: 2016-12-01
Also published as: CN104877329A; CN104877329B

Abstract

Disclosed is a polycarbonate composition, comprising the following components in parts by weight: a. 30-87 parts of a polycarbonate; b. 8-50 parts of an ABS resin; c. 2-25 parts of a flame retardant; d. 0-10 parts of other additives. The sum of the parts by weight of a, b, c and d is 100 parts. On the basis of the total weight of the polycarbonate composition, a phenol substance in a polycarbonate composition formulation does not exceed 20 ppm, and on the basis of the total weight of the polycarbonate composition, the total compounding amount of a metal zinc element and a manganese element does not exceed 200 ppm. The obtained polycarbonate composition has excellent high temperature high humidity performance stability and mechanical properties, and is particularly suitable for use in a situation having relatively high environmental requirements. The structural formula of the phenol substance is shown in formula (1), wherein R₁ and R₅ represent hydrogen groups, alkyl groups, alkoxy groups, hydroxy groups, carboxyl groups or carbonyl groups, with the exception of hindered groups, or ester groups, and R₂, R₃ and R₄ represent hydrogen atom-containing substituents, preferably hydrogen atoms.

Description

Polycarbonate composition and preparation method thereof

Technical field

The invention relates to the technical field of engineering plastics, in particular to a polycarbonate composition and a preparation method thereof.

Background technique

Polycarbonate PC has high impact resistance and heat resistance. In order to improve its processing properties and sensitivity to notch impact, it is usually added to rubber-modified polymers such as ABS, MBS, etc., especially PC. PC/ABS alloy with ABS as the main raw material is an important engineering plastic, which can combine the excellent performance of both, and improve the physical properties and processing performance. However, due to the addition of ABS, the double bond in the system will bring long-term Thermal oxygen aging performance and weathering performance hazards, especially where the use environment is relatively high.

WO 99/11713 A1 discloses an improved moisture resistance and at the same time a high mechanical level of flame retardant PC/ABS, characterized in that the graft polymer has an alkali metal content of less than 1 ppm.

WO 2007/009622 A1 discloses a composition containing polycarbonate and ABS and having a low lithium ion content with impact modification with improved hydrolysis resistance, which is added with low lithium ions in a graft polymer prepared by bulk or emulsion method. The composition of the composition has significantly better hydrolysis resistance than the higher lithium ion content composition.

However, up to now, the total amount of the phenolic substance and the total amount of the metal zinc element and the manganese element has been reported to be stable in the high temperature and high humidity environment of the polycarbonate composition.

The inventors have surprisingly found through extensive experimentation that the addition of a phenolic substance to the polycarbonate composition formulation is not more than 20 ppm based on the total weight of the polycarbonate composition, and the total amount of the metal zinc element and the manganese element is based on the total amount of the compound. When the total weight of the polycarbonate composition is not more than 200 ppm, the obtained polycarbonate composition has excellent high-temperature and high-humidity stability and mechanical properties, and is particularly suitable for applications where the use environment is relatively high.

Summary of the invention

In order to overcome the disadvantages and disadvantages of the prior art, it is an object of the present invention to provide a polycarbonate composition having excellent high temperature and high humidity performance stability and mechanical properties.

Still another object of the present invention is to provide a process for the preparation of the above polycarbonate composition.

The invention is achieved by the following technical solutions:

A polycarbonate composition comprising, by weight, the following composition:

a, 30 parts - 87 parts of polycarbonate;

b, 8 parts - 50 parts of ABS resin;

c, 5 parts - 25 parts of flame retardant;

d, 0-10 parts of other auxiliary agents;

Wherein, the sum of the weight components of the four components a, b, c, and d is 100 parts.

Preferably, a polycarbonate composition, by weight, comprises the following composition:

a, 44 parts - 75 parts of polycarbonate;

b, 8 parts to 30 parts of ABS resin;

c, 5 parts - 18 parts of flame retardant;

d, 0.1-8 parts of other auxiliary agents;

Wherein, the sum of the weight components of the four components a, b, c, d is 100 parts;

The content of the phenolic substance in the total weight of the polycarbonate composition is 1 ppm or more and 20 ppm or less;

The total amount of metal zinc element and manganese element in the total weight of the polycarbonate composition is not more than 200 ppm;

The structural formula of the phenolic substance is as shown in formula (1):

Wherein R ₁ and R ₅ represent a hydrogen group other than a hindered group, an alkyl group, an alkoxy group, a hydroxyl group, a carboxyl group or a carbonyl group, and an ester group, and R ₂ , R ₃ and R ₄ represent a substituent having a hydrogen atom, preferably hydrogen. atom.

Among them, the test method for the content of phenolic substances: weighing 2 g of polycarbonate combination with an electronic balance After the object, the sample was placed in a constant temperature oven at a preset temperature of 120 ° C and the temperature was uniformly stabilized, and then placed in a Soxhlet extraction device for methanol extraction, the extraction temperature was 85 ° C, the time was 48 h, and the extract was extracted. After being placed at a constant temperature, 20 ul was withdrawn through the filter, and the extract was injected into the adsorption column of C18 by means of a mobile phase (methanol: purified water = 90:10) at a flow rate of 10 ml/min for separation and quantification. After establishing a standard curve for standard solutions of 1 ppm, 5 ppm, 10 ppm and 20 ppm, the content of phenols can be calculated by the specific effluent time of the standard and the extrapolation method;

Test method for the content of metallic zinc and manganese metal elements: ICP-MS mixed standard method.

Preferably, the content of the phenolic substance in the total weight of the polycarbonate composition is 10 ppm or more and 2 ppm or more; more preferably 8 ppm or more and 3 ppm or more.

If the residual amount of the phenolic substance is too large, especially in the case of more than 20 ppm, there is a hidden danger that the viscosity changes greatly during the subsequent processing, which causes a large decrease in the performance.

Preferably, the total amount of the metal zinc element and the manganese element in the total weight of the polycarbonate composition is not more than 100 ppm, more preferably not more than 50 ppm. When the total amount of the metal zinc element and the manganese element is more than 200 ppm based on the total weight of the polycarbonate composition, coloring is introduced, which affects the color of the light colored article and limits its application to light colored articles.

Wherein the compounding weight ratio of the metal zinc element to the manganese element in the total weight of the polycarbonate composition is from 0.2 to 20; preferably from 1 to 10; more preferably from 1.5 to 5.

The polycarbonate is selected from one or more of an aromatic polycarbonate, an aliphatic polycarbonate, an aromatic-aliphatic polycarbonate, a branched polycarbonate, and a siloxane copolycarbonate; preferably Aromatic polycarbonate.

The aromatic polycarbonate is an aromatic polycarbonate having a viscosity average molecular weight of 13,000 to 40,000, and preferably an aromatic polycarbonate having a viscosity average molecular weight of 16,000 to 28,000. When the viscosity average molecular weight is within the above range, the mechanical strength is good and excellent moldability can be maintained. Among them, the viscosity average molecular weight was calculated by using a solution of dichloromethane as a solvent at a test temperature of 25 ° C.

The above polycarbonate can be produced by an interfacial polymerization method and a transesterification method, and the terminal hydroxyl group content can be controlled in the process.

Wherein, the ABS resin is selected from one or more of ABS resins prepared by bulk polymerization, bulk-suspension polymerization, and emulsion polymerization; wherein the bulk polymerization ABS particle size is preferably 0.1 um to 2 um, and the emulsion polymerization method is ABS. The particle size is preferably 0.05 um to 0.2 um.

Bulk polymerization: including sol, prepolymerization, polymerization, devolatilization and granulation in five steps: dissolving the rubber In ethylbenzene and styrene, the monomer is formulated into a raw material liquid according to the formula amount, and the prepared raw material liquid is input into the pre-polymerization kettle for pre-polymerization. In the polymerization process, the rubber grafting monomer and the monomer are copolymerized. Separated from the solution to form a discontinuous phase dispersed in the continuous phase of the raw material liquid. When there is enough monomer to polymerize, the discontinuous phase of the copolymer becomes a continuous phase, and the grafted rubber forms a discontinuous phase dispersion. In the continuous copolymer phase, the phase transition is completed, and finally further polymerization, vacuum degassing, extrusion, cooling and pelletizing to obtain the final product;

Bulk-suspension polymerization method: adjust the rubber and monomer solution according to the formulation, and notify the addition of a polymerization regulator and a radical initiator, and carry out bulk polymerization of the monomer mixture at 80 ° C - 120 ° C, stirring constantly during the polymerization, and going Ionic water and a suspending agent are added to the mixture to disperse the mixture, and then suspension polymerization is carried out by using a radical catalyst to obtain a certain degree of polymerization, followed by agglomeration, filtration, washing, dehydration and drying, and then granulating to obtain a product;

Emulsion polymerization method: the rubber is grafted by adding the monomer mixture to the rubber latex at a polymerization temperature of 50 ° C to 80 ° C in an initiator, deionized water, an emulsifier and a crosslinking agent, and finally washing, dehydrating and drying. After granulation, the product is obtained.

Wherein the flame retardant is selected from the group consisting of a halogen-based flame retardant or a halogen-free flame retardant, preferably a halogen-free flame retardant; the halogen-based flame retardant is selected from the group consisting of brominated polystyrene, brominated polyphenylene ether, and bromine Bisphenol A type epoxy resin, brominated styrene-maleic anhydride copolymer, brominated epoxy resin, brominated phenoxy resin, decabromodiphenyl ether, decabromobiphenyl, brominated polycarbonate Or one or more of perfluorotricyclopentadecane or brominated aromatic crosslinked polymer, preferably brominated polystyrene; the halogen-free flame retardant is selected from the group consisting of nitrogen-containing flame retardants and phosphorus-containing resistors One or more of a flammant or a flame retardant containing nitrogen and phosphorus is preferably a phosphorus-containing flame retardant.

Preferably, the phosphorus-containing flame retardant is selected from the group consisting of triphenyl phosphate, tricresyl phosphate, tolyl diphenyl phosphate, trimethylphenyl phosphate, and tris(2,4,6-trimethyl phosphate). Phenyl) ester, tris(2,4-di-tert-butylphenyl) phosphate, tris(2,6-di-tert-butylphenyl) phosphate, resorcinol bis(diphenyl phosphate) , hydroquinone bis(diphenyl phosphate), bisphenol A-bis(diphenyl phosphate), resorcinol bis(2,6-di-tert-butylphenyl phosphate), p-phenylene One or more of phenol bis(2,6-dimethylphenyl phosphate).

The other auxiliary agent in the polycarbonate composition is selected from the group consisting of a toughening agent, a stabilizer, a flame retardant synergist, an anti-drip agent, a lubricant, a mold release agent, a plasticizer, a filler, a colorant or Several.

Suitable stabilizers include organic phosphites such as triphenyl phosphite, tris-(2,6-dimethylphenyl) phosphite, tri-decylphenyl phosphite, dimethylphenylphosphonic acid Ester, trimethyl phosphate, etc., organic phosphite, alkylated monohydric or polyhydric phenol, alkylation reaction product of polyhydric phenol and diene, p-cresol or The butylated reaction product of dicyclopentadiene, alkylated hydroquinones, hydroxylated thiodiphenyl ethers, alkylene-bisphenols, benzyl compounds, polyol esters, benzo One or more combinations of triazoles, benzophenones.

A suitable plasticizer is a phthalate.

Suitable release agents include metal stearates, alkyl stearates, pentaerythritol stearate, paraffin, montan wax, and the like.

Suitable colorants include various pigments, dyes.

The preparation method of the above polycarbonate composition comprises the following steps:

1) a manganese-containing compound and a zinc-containing compound and a phenylsiloxane are formulated into a phenylsiloxane solution having a mass fraction of from 0.15 ppm to 300 ppm;

2) blending the phenylsiloxane solution with a polycarbonate containing 8 ppm to 60 ppm of a phenolic substance in a high-mixer to obtain a pretreated polycarbonate;

3) The pretreated polycarbonate, graft copolymer, flame retardant, and other auxiliary agents are weighed according to the ratio, and then blended by high mixing machine or mixer, extruded, cooled by water, and granulated to obtain a columnar shape. Granular polycarbonate composition.

Wherein the manganese-containing compound is one or more selected from the group consisting of manganese dioxide, manganese chloride, manganese nitrate, manganese carbonate, and manganese sulfate; and the zinc-containing compound is selected from the group consisting of zinc chloride, zinc sulfate, and zinc nitrate. One or more of zinc carbonate and zinc sulfide.

The polycarbonate containing a phenolic substance can obtain a polycarbonate resin containing a different content of a phenolic substance by a different synthesis method, thereby realizing a residual phenolic substance content in the final polycarbonate composition. Wherein, the content of the residual phenolic substance in the final polycarbonate composition is calculated as: mass percentage of the polycarbonate formulation * phenolic content of the polycarbonate containing the phenolic substance = residual phenolic of the polycarbonate composition Material content.

The polycarbonate composition of the invention has excellent long-term heat and humidity aging resistance, processing stability and mechanical properties, can be used for a long time under high temperature and high humidity without failure, and can be used for outdoor and indoor applications, such as various types. And size housing components, household appliances such as televisions, printers, modem housings, display housings, etc., or automotive components for outdoor use, enclosures or covers for architectural applications, and electrical appliance housings and bezels.

Compared with the prior art, the invention has the following beneficial effects:

The phenolic material in the polycarbonate composition formulation of the present invention is based on the total of the polycarbonate composition. Not more than 20 ppm by weight, and the total amount of metal zinc element and manganese element is not more than 200 ppm based on the total weight of the polycarbonate composition, passing trace amounts of phenolic substances and trace amounts of metallic zinc and manganese The synergistic effect of the compounding provides the polycarbonate composition with excellent high-temperature and high-humidity stability and mechanical properties, and is particularly suitable for applications where the use environment is relatively high.

detailed description

The invention is further illustrated by the following detailed description of the preferred embodiments of the invention, but the embodiments of the invention are not limited by the following examples.

Test criteria or methods for each performance:

Method for determining the content of phenolic substances: After weighing 2 g of the polycarbonate composition with an electronic balance, the sample was placed in a constant temperature oven at a preset temperature of 120 ° C and the temperature was uniformly stabilized, and then placed in a Soxhlet extraction apparatus. Methanol extraction, extraction temperature is 85 ° C, time is 48h, the extract is placed at a constant temperature, 20ul is withdrawn through the filter, at a flow rate of 10ml / min, by mobile phase (methanol: purified water = 90:10) The extract is injected into the adsorption column of C18 for separation and quantification. After establishing the standard curve by establishing standard solutions of 1 ppm, 5 ppm, 10 ppm and 20 ppm, the phenol can be calculated by the specific effluent time of the standard and the extrapolation method. The content of the substance;

Test method for metal zinc content and metal manganese content: ICP-MS mixed standard method;

Determination method of viscosity ratio (100h, 500h) after double 85 test: GB/T1632 weighs the pellets and puts in a constant temperature and humidity aging box with a humidity of 85% and a temperature of 85 °C. 2g is taken at intervals and dissolved with chloroform. After the viscosity was measured by an Ubbelohde viscometer, the viscosity ratio was calculated according to the following formula:

(N1-N2)/N1

N1 represents the intrinsic viscosity of 0h before aging; N2 represents the intrinsic viscosity measured after a certain period of time (100h, 500h) of double 85 damp heat aging. The larger the viscosity ratio value, the worse the stability is. On the contrary, the smaller the value, the stability. The better.

Measurement method of 150 ° C impact performance retention rate (500 h): The test sample was obtained by an 80-ton injection molding machine manufactured by Nissei Resin Co., Ltd. under the conditions of a cylinder temperature of 280 ° C and a mold temperature of 100 ° C, in accordance with ASTM D265. The Izod impact tester (manufactured by Toyo Seiki Co., Ltd.) was used to measure the notched Izod impact value, and the sample was aged in a constant temperature oven at a preset temperature of 150 ° C for 500 hours, according to the foregoing. The test method measures the Izod impact value after aging, according to the retention rate The formula yields a 150°C impact performance retention rate. The larger the value, the better the performance.

Polycarbonate used in the present invention:

Component a-1: PC phenolic substance content is 8 ppm, preparation method: adding a quantitative aqueous solution of NaOH to the liquid phase phenolic substance for interfacial polymerization to obtain intermediate product DPC, and then controlling the residual amount of phenolic substance by washing to 8 ppm and Bisphenol A is obtained by melt transesterification to give the final product.

Component a-2: PC phenolic substance content is 18 ppm, preparation method: adding a quantitative aqueous solution of NaOH to the liquid phase phenolic substance for interfacial polymerization to obtain intermediate product DPC, and then controlling the residual amount of phenolic substance by washing to 18 ppm and Bisphenol A is obtained by melt transesterification to give the final product.

Component a-3: PC phenolic substance content is 60 ppm, preparation method: adding a quantitative aqueous solution of NaOH to the liquid phase phenolic substance for interfacial polymerization to obtain intermediate product DPC, and then controlling the residual amount of phenolic substance by washing to 60 ppm and Bisphenol A is obtained by melt transesterification to give the final product.

The phenolic substances used therein:

Phenol: (Shanghai TCI);

P-methylphenols: (Aladdin);

Dimethylphenols: (Aladdin);

ABS resin used in the present invention:

Component b-1: ABS 8391 (Shanghai Gaoqiao)

Component b-2: ABS 757 (Taiwan Chi Mei)

Flame retardant used in the present invention:

Component c-1: BDP (bisphenol A-bis (triphenyl phosphate), Edico;

Component c-2: RDP (resorcinol-bis(diphenyl phosphate), Zhejiang Wansheng;

Component c-3: TPP (triphenyl phosphate), Tianjin Beyond;

Other auxiliaries used in the present invention:

Component d-1: AO168: tris[2.4-di-tert-butylphenyl]phosphite as stabilizer; (BASF)

Component d-2: PETS: as a lubricant (Longsha, USA)

Component d-3: PTFE: Polytetrafluoroethylene as an anti-drip agent (Guangzhou entropy energy).

Examples 1-9 and Comparative Examples 1-11: Preparation of Polycarbonate Compositions

The manganese-containing compound and the zinc-containing compound and the phenylsiloxane are formulated into a phenylsiloxane solution having a mass fraction of 0.15 ppm to 300 ppm; and the phenylsiloxane solution is contained in an amount of 8 ppm to 60 ppm. Polycarbonate of phenolic substance is blended in a high-mixer to obtain a pretreated polycarbonate; after pre-treated polycarbonate, graft copolymer, flame retardant, and other auxiliary agents are weighed in proportion, Blending, extrusion, water cooling, granulation to obtain columnar granules of polycarbonate composition by high mixer or mixer; viscosity ratio (100h, 150h) to polycarbonate composition and impact performance retention rate ( 150h) Test, the data is shown in Table 1.

Table 1 Specific ratios (parts by weight) of Examples 1-9 and Comparative Examples 1-11 and test performance results thereof

Continued Table 1

It can be seen from the comparison of the examples of Table 1 and the comparative examples that the phenolic substance in the polycarbonate composition formulation is not more than 20 ppm based on the total weight of the polycarbonate composition, and the complex of the metal zinc element and the manganese element. When the total amount is not more than 200 ppm based on the total weight of the polycarbonate composition, the obtained polycarbonate composition has excellent high-temperature and high-humidity stability and mechanical properties.

Claims

A polycarbonate composition comprising, by weight, the following composition:

a, 30 parts - 87 parts of polycarbonate;

b, 8 parts - 50 parts of ABS resin;

c, 2 parts - 25 parts of flame retardant;

d, 0-10 parts of other auxiliary agents;

Wherein, the sum of the weight components of the four components a, b, c, and d is 100 parts.
A polycarbonate composition according to claim 1 comprising, by weight, the following composition:

a, 44 parts - 75 parts of polycarbonate;

b, 8 parts to 30 parts of ABS resin;

c, 5 parts - 18 parts of flame retardant;

d, 0.1-8 parts of other auxiliary agents;

Wherein, the sum of the weight components of the four components a, b, c, d is 100 parts;

The content of the phenolic substance in the total weight of the polycarbonate composition is 1 ppm or more and 20 ppm or less;

The total amount of metal zinc element and manganese element in the total weight of the polycarbonate composition is not more than 200 ppm;

The structural formula of the phenolic substance is as shown in formula (1):

Wherein R 1 and R 5 represent a hydrogen group other than a hindered group, an alkyl group, an alkoxy group, a hydroxyl group, a carboxyl group or a carbonyl group, and an ester group, and R 2 , R 3 and R 4 represent a substituent having a hydrogen atom, preferably hydrogen. atom.
The polycarbonate composition according to claim 2, wherein the content of the phenolic substance in the total weight of the polycarbonate composition is 10 ppm or more and 2 ppm or more; preferably 8 ppm or less and 3 ppm or more.
The polycarbonate composition according to claim 2, wherein the total amount of the metal zinc element and the manganese element in the total weight of the polycarbonate composition is not more than 100 ppm, preferably not more than 50 ppm.
The polycarbonate composition according to any one of claims 2 to 4, wherein the compounding weight ratio of the metal zinc element to the manganese element in the total weight of the polycarbonate composition is from 0.2 to 20; preferably 1-10; more preferably 1.5-5.
The polycarbonate composition according to claim 1 or 2, wherein the polycarbonate is selected from the group consisting of an aromatic polycarbonate, an aliphatic polycarbonate, an aromatic-aliphatic polycarbonate, and a branched poly One or more of a carbonate or a siloxane copolycarbonate; preferably an aromatic polycarbonate.
The polycarbonate composition according to claim 6, wherein the aromatic polycarbonate is an aromatic polycarbonate having a viscosity average molecular weight of 13,000 to 40,000, preferably an aromatic polycondensation having a viscosity average molecular weight of 16,000 to 28,000 Carbonate.
The polycarbonate composition according to claim 1 or 2, wherein the ABS resin is one or more selected from the group consisting of a bulk polymerization method, a bulk-suspension polymerization method, and an emulsion polymerization method; The bulk polymerization method ABS particle size is preferably 0.1 um to 2 um, and the emulsion polymerization method ABS particle diameter is preferably 0.05 um to 0.2 um.
The polycarbonate composition according to claim 1 or 2, wherein the flame retardant is selected from a halogen-based flame retardant or a halogen-free flame retardant, preferably a halogen-free flame retardant; The flammable agent is selected from the group consisting of brominated polystyrene, brominated polyphenylene ether, brominated bisphenol A type epoxy resin, brominated styrene-maleic anhydride copolymer, brominated epoxy resin, brominated phenoxy resin, One or more of decabromodiphenyl ether, decabromobiphenyl, brominated polycarbonate, perbromotricyclopentadecane or brominated aromatic crosslinked polymer, preferably brominated polystyrene; The halogen-free flame retardant is selected from one or more of a nitrogen-containing flame retardant, a phosphorus-containing flame retardant, and a nitrogen and phosphorus-containing flame retardant, preferably a phosphorus-containing flame retardant.
The polycarbonate composition according to claim 9, wherein the phosphorus-containing flame retardant is selected from the group consisting of triphenyl phosphate, tricresyl phosphate, tolyl diphenyl phosphate, and trimethyl xylene phosphate. Base ester, tris(2,4,6-trimethylphenyl) phosphate, tris(2,4-di-tert-butylphenyl) phosphate, tris(2,6-di-tert-butylphenyl) phosphate Ester, resorcinol bis(diphenyl phosphate), hydroquinone bis(diphenyl phosphate), bisphenol A-bis (phosphorus) One or more of diphenyl 2,6-di-tert-butylphenyl phosphate Kind.
The polycarbonate composition according to claim 1 or 2, wherein the other auxiliary agent is selected from the group consisting of a toughening agent, a stabilizer, a flame retardant synergist, an anti-drip agent, a lubricant, and a release agent. One or more of plasticizers, fillers, and colorants.
A method of preparing a polycarbonate composition according to any one of claims 1 to 11, comprising the steps of:

1) a manganese-containing compound and a zinc-containing compound and a phenylsiloxane are formulated into a phenylsiloxane solution having a mass fraction of from 0.15 ppm to 300 ppm;

2) blending the phenylsiloxane solution with a polycarbonate containing 8 ppm to 60 ppm of a phenolic substance in a high-mixer to obtain a pretreated polycarbonate;

3) The pretreated polycarbonate, graft copolymer, flame retardant, and other auxiliary agents are weighed according to the ratio, and then blended by high mixing machine or mixer, extruded, cooled by water, and granulated to obtain a columnar shape. Granular polycarbonate composition.
The method for preparing a polycarbonate composition according to claim 12, wherein the manganese-containing compound is one or more selected from the group consisting of manganese dioxide, manganese chloride, manganese nitrate, manganese carbonate, and manganese sulfate. The zinc-containing compound is selected from one or more of zinc chloride, zinc sulfate, zinc nitrate, zinc carbonate, and zinc sulfide.