Method for detecting content of carbon black in master batch

Abstract

The invention discloses a method for detecting the content of carbon black in master batch, which comprises the following steps: S1) weighing the master batch with the mass G into a reaction tube, adding methanol, a cosolvent and a catalyst, sealing, and heating for alcoholysis; s2) taking out the reaction tube, cooling to room temperature, opening a cover, pouring a solution in the reaction tube into filter paper with the mass of W0, flushing the reaction tube with ethanol, pouring the solution into the filter paper to completely transfer the solution, flushing filter residues with hot absolute ethanol, and drying the filter paper with the filter residues, wherein the mass of the dried filter paper and the filter residues is W1; s3) putting the dried filter paper with the filter residues into a crucible with the mass of W2, ashing, transferring the crucible into a muffle furnace, calcining, and weighing the mass of the crucible and the ash content as W3 after the weight is constant; and S4) calculating the carbon black content in the master batch according to the following formula: omega = (W1-W0) / G * 100%-(W3-W2) / G * 100%. According to the method, ash content in the detection result is removed, the accuracy is high, the test repeatability is good, the operation is simple, and the energy consumption in the detection process is low.

Description

Technical Field

[0001] The present invention relates to the technical field of masterbatch composition analysis, and particularly to a method for detecting the carbon black content in a masterbatch. Background Art

[0002] The carbon black content affects the mechanical, optical and other properties of black masterbatch. Too high or too low carbon black content may lead to differences in properties such as the dispersibility, tensile strength, and weather resistance of black masterbatch. In large-scale production, the carbon black content of different batches of black masterbatch must be stable and consistent to ensure uniform product quality. By detecting the carbon black content, the production process can be adjusted in a timely manner to ensure the quality stability of each batch of products, which is conducive to enterprises establishing a good brand image and enhancing market competitiveness.

[0003] In the prior art, for example, a method for detecting the carbon black content in a black masterbatch with the application number 201310016183.1 discloses that after alcoholysis of the masterbatch with methanol, 190# solvent oil is added to remove the liquid, and then the carbon black content is calculated after vacuum drying. However, the above detection method has a high alcoholysis temperature, a long time, and does not remove the ash content in the masterbatch, resulting in high detection energy consumption and inaccurate detection results. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for detecting the carbon black content in a masterbatch to solve the problems in the background art.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a method for detecting the carbon black content in a masterbatch, comprising the following steps: S1) Weigh a masterbatch with a mass of G into a reaction tube, add methanol, a co-solvent and a catalyst, seal and tighten it, and heat it in a multi-tube constant temperature heater for alcoholysis; S2) Take out the reaction tube, place it in flowing water to cool to room temperature, open the lid, pour the solution in the reaction tube onto a filter paper with a mass of W0, rinse the reaction tube with ethanol and pour it onto the filter paper to completely transfer the solution, rinse the filter residue with hot absolute ethanol 2-3 times until the dimethyl terephthalate crystals are completely dissolved, leaving carbon black filter residue. Place the filter paper with the filter residue in an oven for drying, and the mass of the dried filter paper and filter residue is W1; S3) Place the dried filter paper with the filter residue in a crucible with a mass of W2, and ash it on an electric furnace, then transfer the crucible to a muffle furnace for calcination. After constant weight, weigh the mass of the crucible and ash as W3; S4) Calculate the carbon black content in the masterbatch according to the following formula: ω=(W1 - W0) / G×100% - (W3 - W2) / G×100%, where: ω is the carbon black content in the masterbatch, Further, let (W1 - W0) / G×100% be the content ω1 of carbon black (including ash) in the sample, and (W3 - W2) / G×100% be the ash content ASH of the sample, then ω = ω1 - ASH.

[0006] As a further optimization, the cosolvent described in S1 includes one or more of acetonitrile, dichloromethane, cyclohexane, and tetrahydrofuran. Compared with conventional methanol alcoholysis, the addition of the cosolvent can significantly reduce the reaction temperature and shorten the reaction time. It is preferred to use acetonitrile as the cosolvent, and 100% conversion of PET can be achieved at 120 °C for 2 h. The addition of acetonitrile can increase the specific surface area of PET, thereby increasing the mass transfer coefficient of methanol and strengthening the mass transfer process of the reaction, thus promoting the contact between methanol and PET and making the reaction easier to proceed.

[0007] As a further optimization, the catalyst described in S1 is zinc acetate.

[0008] As a further optimization, the ratio of the mass of the masterbatch described in S1 to the sum of the volumes of the methanol and the cosolvent is 1 g:(25 - 50) mL, and the mass of the catalyst is 0.1 - 1% of the mass of the masterbatch, preferably 0.5%.

[0009] As a further optimization, the alcoholysis temperature in S1 is 110 - 140 °C, preferably 120 °C, and the alcoholysis time is 1 - 4 h, preferably 2 h.

[0010] As a further optimization, the reaction tube described in S1 is made of 50 ml stainless steel.

[0011] As a further optimization, the temperature of the absolute ethanol described in S2 is 60 - 70 °C.

[0012] As a further optimization, the drying temperature in S2 is 100 - 105 °C, and the drying time is 1 - 2 h.

[0013] As a further optimization, the calcination temperature in S3 is 900 - 950 °C, and the calcination time is 1 - 2 h.

[0014] As a further optimization, during ashing in S3, it needs to be burned until there is no smoke, and during calcination, it needs to be burned until there is no carbon black.

[0015] As a further optimization, to ensure the accuracy of the experimental results, the filter paper, crucible, etc. used need to be weighed to a constant weight before use.

[0016] As a further optimization, in S4, the test results are taken as the arithmetic mean of two parallel samples, and the absolute error of parallelism does not exceed 1%.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. The test results have removed the ash content, with high accuracy and good test repeatability; 2. During the alcoholysis process, adding a co-solvent (such as acetonitrile) can increase the specific surface area of the masterbatch, improve the mass transfer coefficient of methanol, strengthen the mass transfer process of the reaction, promote the contact between methanol and the masterbatch, reduce the reaction temperature, and shorten the reaction time; 3. The operation of the present invention is simple, and the energy consumption during the detection process is low. Specific Embodiments

[0018] The following are specific embodiments of the present invention, which further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0019] The following further details the present invention through examples. All reagents used can be purchased commercially, and the test instruments used are an electronic analytical balance, an oven, a multi-tube constant temperature heater, an electric furnace, a muffle furnace, and a water bath heater. Examples

[0020] A method for detecting the carbon black content in a masterbatch includes the following steps: S1) Weigh 1.1000 g of PET-based black masterbatch and pour it into a stainless steel reaction tube. Add methanol, acetonitrile, and zinc acetate. After sealing and tightening, heat it in a multi-tube constant temperature heater at 120 °C for 2 h for alcoholysis. The volume of the methanol-acetonitrile mixed solution is 30 ml, the volume ratio of the two is 4:1, and the mass of zinc acetate is 0.005 g; S2) Take out the reaction tube and cool it to room temperature in flowing water. After opening the lid, pour the solution in the reaction tube onto a filter paper with a mass of W0. Rinse the reaction tube with ethanol and pour it onto the filter paper to completely transfer the solution. Rinse the filter residue with anhydrous ethanol at 60 °C 2 - 3 times. Place the filter paper with the filter residue in a drying oven and dry it at 105 °C for 1.5 h. The mass of the dried filter paper and filter residue is W1. Among them, W0 is 0.9735 g and W1 is 1.2572 g; S3) Place the dried filter paper with the filter residue in a crucible with a mass of W2, and perform ashing on an electric furnace until there is no smoke during combustion. Then transfer the crucible to a muffle furnace for calcination, calcine at 900 °C for 1 - 2 h until the carbon black disappears, cool it, and weigh the mass of the crucible and ash as W3 after constant weight. Among them, W2 is 56.7138 g and W3 is 56.7166 g; S4) Calculate the carbon black content in the masterbatch according to the following formula: ω=(W1 - W0) / G×100%-(W3 - W2) / G×100% = 25.54%, where: ω is the carbon black content in the masterbatch, (W1 - W0) / G×100% is the content of carbon black (including ash) in the sample ω1 = 25.79%, and (W3 - W2) / G×100% is the content of ash in the sample ASH = 0.25%. Example

[0021] A method for detecting the carbon black content in masterbatch, comprising the following steps: S1) Weigh 0.9998 g of PET-based black masterbatch and pour it into a stainless steel reaction tube. Add methanol, acetonitrile and zinc acetate. After sealing and tightening, heat it in a multi-tube constant temperature heater at 120 °C for 2 h for alcoholysis. The volume of the methanol-acetonitrile mixture is 30 ml, and the volume ratio of the two is 3:1. The mass of zinc acetate is 0.005 g; S2) Take out the reaction tube and cool it to room temperature in flowing water. After opening the lid, pour the solution in the reaction tube onto a filter paper with a mass of W0. Rinse the reaction tube with ethanol and pour it onto the filter paper to completely transfer the solution. Rinse the filter residue with anhydrous ethanol at 60 °C 2-3 times. Place the filter paper with the filter residue in an oven and dry it at 105 °C for 1.5 h. The mass of the dried filter paper and filter residue is W1, where W0 is 0.9419 g and W1 is 1.2431 g; S3) Place the dried filter paper with the filter residue in a crucible with a mass of W2, and ash it on an electric furnace until there is no more smoke. Then transfer the crucible to a muffle furnace and calcine it at 900 °C for 1-2 h until the carbon black disappears. Cool it and weigh the mass of the crucible and ash as W3 after constant weight, where W2 is 55.7574 g and W3 is 55.7596 g; S4) Calculate the carbon black content in the masterbatch according to the following formula: ω=(W1 - W0) / G×100%-(W3 - W2) / G×100% = 29.91%, where: ω is the carbon black content in the masterbatch, (W1 - W0) / G×100% is the content of carbon black (including ash) in the sample ω1 = 30.13%, and (W3 - W2) / G×100% is the content of ash in the sample ASH = 0.22%. Example

[0022] A method for detecting the carbon black content in masterbatch, comprising the following steps: S1) Weigh 1.0004 g of PET-based black masterbatch and pour it into a stainless steel reaction tube. Add methanol, acetonitrile and zinc acetate. After sealing and tightening, heat it in a multi-tube constant temperature heater at 120 °C for 2 h for alcoholysis. The volume of the methanol-acetonitrile mixture is 30 ml, and the volume ratio of the two is 2:1. The mass of zinc acetate is 0.005 g; S2) Take out the reaction tube and cool it to room temperature in running water. After opening the lid, pour the solution in the reaction tube onto a filter paper with a mass of W0. Rinse the reaction tube with ethanol and pour it onto the filter paper to completely transfer the solution. Rinse the residue with absolute ethanol at 60 °C 2 - 3 times. Place the filter paper with the residue in an oven and dry it at 105 °C for 1.5 h. The mass of the filter paper and the residue after drying is W1, where W0 is 0.9807 g and W1 is 1.2575 g; S3) Place the dried filter paper with the residue in a crucible with a mass of W2, and ash it on an electric furnace until there is no more smoke. Then transfer the crucible to a muffle furnace and calcine it at 900 °C for 1 - 2 h until the carbon black disappears. Cool it, and after constant weighing, the mass of the crucible and the ash is W3, where W2 is 56.6814 g and W3 is 56.6842 g; S4) Calculate the carbon black content in the masterbatch according to the following formula: ω=(W1 - W0) / G×100%-(W3 - W2) / G×100% = 27.39%, where: ω is the carbon black content in the masterbatch, (W1 - W0) / G×100% is the carbon black (including ash) content ω1 = 27.67% in the sample, and (W3 - W2) / G×100% is the ash content ASH = 0.28% in the sample. Example

[0023] A method for detecting the carbon black content in a masterbatch, comprising the following steps: S1) Weigh 1.0000 g of PET - based black masterbatch and pour it into a stainless - steel reaction tube. Add methanol, acetonitrile, and zinc acetate. After sealing tightly, heat it in a multi - tube constant - temperature heater at 120 °C for 2 h for alcoholysis. The volume of the methanol - acetonitrile mixed solution is 25 ml, the volume ratio of the two is 3:1, and the mass of zinc acetate is 0.005 g; S2) Take out the reaction tube and cool it to room temperature in running water. After opening the lid, pour the solution in the reaction tube onto a filter paper with a mass of W0. Rinse the reaction tube with ethanol and pour it onto the filter paper to completely transfer the solution. Rinse the residue with absolute ethanol at 60 °C 2 - 3 times. Place the filter paper with the residue in an oven and dry it at 105 °C for 1.5 h. The mass of the filter paper and the residue after drying is W1, where W0 is 0.9476 g and W1 is 1.2391 g; S3) Place the dried filter paper with the residue in a crucible with a mass of W2, and ash it on an electric furnace until there is no more smoke. Then transfer the crucible to a muffle furnace and calcine it at 900 °C for 1 - 2 h until the carbon black disappears. Cool it, and after constant weighing, the mass of the crucible and the ash is W3, where W2 is 56.6801 g and W3 is 56.6829 g; S4) Calculate the carbon black content in the masterbatch according to the following formula: ω = (W1 - W0) / G × 100% - (W3 - W2) / G × 100% = 28.87%, where: ω is the carbon black content in the masterbatch, (W1 - W0) / G × 100% is the carbon black (including ash) content ω1 = 29.15% in the sample, and (W3 - W2) / G × 100% is the ash content ASH = 0.28% in the sample. Example

[0024] A method for detecting the carbon black content in a masterbatch, comprising the following steps: S1) Weigh 1.0007 g of PET-based black masterbatch and pour it into a stainless steel reaction tube. Add methanol, acetonitrile, and zinc acetate. After sealing and tightening, heat it in a multi-tube constant temperature heater at 130 °C for 2 h for alcoholysis. The volume of the methanol-acetonitrile mixture is 30 ml, the volume ratio of the two is 3:1, and the mass of zinc acetate is 0.005 g; S2) Take out the reaction tube and cool it to room temperature in flowing water. After opening the lid, pour the solution in the reaction tube onto a filter paper with a mass of W0. Rinse the reaction tube with ethanol and pour it onto the filter paper to completely transfer the solution. Rinse the filter residue 2 - 3 times with absolute ethanol at 60 °C. Place the filter paper with the filter residue in an oven and dry it at 105 °C for 1.5 h. The mass of the dried filter paper and filter residue is W1, where W0 is 0.9520 g and W1 is 1.2542 g; S3) Place the dried filter paper with the filter residue in a crucible with a mass of W2, and place it on an electric furnace for ashing until it burns without smoke. Then transfer the crucible to a muffle furnace and calcine it at 900 °C for 1 - 2 h until the carbon black disappears. Cool it and weigh the mass of the crucible and ash as W3 after constant weight, where W2 is 56.7131 g and W3 is 56.7161 g; S4) Calculate the carbon black content in the masterbatch according to the following formula: ω = (W1 - W0) / G × 100% - (W3 - W2) / G × 100% = 29.90%, where: ω is the carbon black content in the masterbatch, (W1 - W0) / G × 100% is the carbon black (including ash) content ω1 = 30.20% in the sample, and (W3 - W2) / G × 100% is the ash content ASH = 0.30% in the sample. Example

[0025] A method for detecting the carbon black content in a masterbatch, comprising the following steps: S1) Weigh 1.0007 g of PET-based black masterbatch and pour it into a stainless steel reaction tube. Add methanol, acetonitrile and zinc acetate. After sealing and tightening, heat it in a multi-tube constant temperature heater at 120 °C for 3 h for alcoholysis. The volume of the methanol-acetonitrile mixture is 30 ml, and the volume ratio of the two is 3:1. The mass of zinc acetate is 0.005 g; S2) Take out the reaction tube and cool it to room temperature in flowing water. After opening the lid, pour the solution in the reaction tube onto a filter paper with a mass of W0. Rinse the reaction tube with ethanol and pour it onto the filter paper to completely transfer the solution. Rinse the filter residue with anhydrous ethanol at 60 °C 2 - 3 times. Place the filter paper with the filter residue in an oven and dry it at 105 °C for 1.5 h. The mass of the dried filter paper and filter residue is W1. Among them, W0 is 0.9327 g and W1 is 1.2313 g; S3) Place the dried filter paper with the filter residue in a crucible with a mass of W2, and place it on an electric furnace for ashing until it burns without smoke. Then transfer the crucible to a muffle furnace and calcine it at 900 °C for 1 - 2 h until the carbon black disappears. Cool it and weigh the mass of the crucible and the ash as W3 after constant weight. Among them, W2 is 55.7557 g and W3 is 55.7584 g; S4) Calculate the carbon black content in the masterbatch according to the following formula: ω=(W1 - W0) / G×100%-(W3 - W2) / G×100% = 29.57%, where: ω is the carbon black content in the masterbatch, (W1 - W0) / G×100% is the carbon black (including ash) content ω1 = 29.84% in the sample, and (W3 - W2) / G×100% is the ash content ASH = 0.27% in the sample. Example

[0026] A method for detecting the carbon black content in a masterbatch, comprising the following steps: S1) Weigh 1.0011 g of PET-based black masterbatch and pour it into a stainless steel reaction tube. Add methanol, acetonitrile and zinc acetate. After sealing and tightening, heat it in a multi-tube constant temperature heater at 120 °C for 2 h for alcoholysis. The volume of the methanol-acetonitrile mixture is 30 ml, and the volume ratio of the two is 3:1. The mass of zinc acetate is 0.005 g; S2) Take out the reaction tube and cool it to room temperature in flowing water. After opening the lid, pour the solution in the reaction tube onto a filter paper with a mass of W0. Rinse the reaction tube with ethanol and pour it onto the filter paper to completely transfer the solution. Rinse the filter residue with anhydrous ethanol at 60 °C 2 - 3 times. Place the filter paper with the filter residue in an oven and dry it at 105 °C for 1.5 h. The mass of the dried filter paper and filter residue is W1. Among them, W0 is 0.9370 g and W1 is 1.2387 g; S3) Place the dried filter paper with filter residue in a crucible with a mass of W2, and place it on an electric furnace for ashing until it burns without smoke. Then transfer the crucible to a muffle furnace and calcine it at 900 °C for 1 - 2 h until the carbon black disappears. After cooling and constant weighing, the mass of the crucible and the ash is W3, where W2 is 56.6820 g and W3 is 56.6835 g; S4) Calculate the carbon black content in the masterbatch according to the following formula: ω = (W1 - W0) / G × 100% - (W3 - W2) / G × 100% = 29.99%, where: ω is the carbon black content in the masterbatch, (W1 - W0) / G × 100% is the carbon black (including ash) content ω1 = 30.14% in the sample, and (W3 - W2) / G × 100% is the ash content ASH = 0.15% in the sample.

[0027] Comparative Example 1: Use the method for measuring the carbon black content in a black masterbatch as described in Application No. 201310016183.1 for detection. The specific steps are as follows: Weigh 1.0022 g of PET substrate black masterbatch (this PET substrate black masterbatch was weighed synchronously when weighing in Example 1 and reserved for later use), add it to a stainless steel reaction tube, add 5 mL of methanol solvent, cover the tube, heat it to 230 °C in a multi-tube constant temperature heater and keep it for 4 h, then rinse the reaction tube with cold water, cool it to room temperature, open the tube plug, and pour out the liquid in the reaction tube; Add No. 190 solvent oil to the container to completely immerse the sample in No. 190 solvent oil, cover the tube, heat it in a boiling water bath at 95 °C for 2 minutes and then pour out the liquid 4 times repeatedly. Then place the container in a vacuum drying oven, control the vacuum temperature at 0.001 MPa, set the temperature at 90 °C, dry it for 2 h, pour out the solid in the container, and weigh it as 0.274 g; According to the above data, the carbon black content in the PET substrate black masterbatch measured in Comparative Example 1 is 0.274 g / 1.0022 g × 100% = 27.34%.

[0028] The carbon black content in the same kind of black masterbatch measured by the method for measuring the carbon black content in a black masterbatch as described in Application No. 201310016183.1 is 27.34%, and the carbon black content in the same kind of black masterbatch measured by the method for detecting the carbon black content in a masterbatch of this application is 25.54%. From the comparison of the above two data, it can be seen that on the premise of the same kind of masterbatch, the carbon black content detected by this application is lower. This is mainly because the ash content is removed in the detection result, making the detection result more accurate. The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains may make various modifications or supplements to the described specific embodiments or use similar methods for substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A method for detecting the carbon black content in a masterbatch, characterized in that, It includes the following steps: S1) Weigh masterbatch with a mass of G into a reaction tube, add methanol, co-solvent and catalyst, seal and heat for alcoholysis; S2) Take out the reaction tube and cool it to room temperature. Pour the solution in the reaction tube onto a filter paper with a mass of W0. Rinse the reaction tube with ethanol and pour it onto the filter paper. Rinse the filter residue with hot absolute ethanol 2 - 3 times. Dry the filter paper with the filter residue. The mass of the dried filter paper and filter residue is W1; S3) Place the dried filter paper with the filter residue in a crucible with a mass of W2, carry out ashing, then transfer the crucible to a muffle furnace for calcination. Weigh the mass of the crucible and the ash as W3 after constant weight; S4) Calculate the carbon black content in the masterbatch according to the following formula: ω=(W1 - W0) / G×100%-(W3 - W2) / G×100%, where: ω is the carbon black content in the masterbatch.

2. The method for detecting the carbon black content in the masterbatch according to claim 1, characterized in that, The co-solvent described in S1 includes one or more of acetonitrile, dichloromethane, cyclohexane and tetrahydrofuran.

3. The detection method of the carbon black content in the masterbatch according to claim 1, characterized in that, The catalyst described in S1 is zinc acetate.

4. The method for detecting the carbon black content in the masterbatch according to claim 1 or 2 or 3, characterized in that, The ratio of the mass of the masterbatch described in S1 to the sum of the volumes of the methanol and co-solvent is 1g:(25 - 50) mL, and the mass of the catalyst is 0.1 - 1% of the mass of the masterbatch.

5. The method for detecting the carbon black content in the masterbatch according to claim 1, characterized in that, The alcoholysis temperature in S1 is 110 - 140°C, and the alcoholysis time is 1 - 4h.

6. The method for detecting the carbon black content in the masterbatch according to claim 1, characterized in that, The reaction tube described in S1 is made of stainless steel.

7. The method for detecting the carbon black content in the masterbatch according to claim 1, wherein The temperature of the absolute ethanol described in S2 is 60 - 70°C.

8. The method for detecting the carbon black content in the masterbatch according to claim 1 or 7, characterized in that, The drying temperature in S2 is 100 - 105°C, and the drying time is 1 - 2h.

9. The method for detecting the carbon black content in the masterbatch according to claim 1, wherein The calcination temperature in S3 is 900 - 950°C, and the calcination time is 1 - 2h.

10. The method for detecting the carbon black content in the masterbatch according to claim 1 or 9, characterized in that, During ashing in S3, it needs to be burned until there is no smoke, and during calcination, it needs to be burned until there is no carbon black.