Some standard content:
Chemical Industry Standard of the People's Republic of China
Percyanidin Resin for Coatings
Subject Content and Applicable Scope
HG 2002—91
This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, transportation, storage, etc. of perchloridin resin for coatings. This standard applies to perchloridin resin obtained by fluorination of polyvinyl fluoride resin with fluorine gas. 2 Reference Standards
GB602 Chemical Reagents
Preparation of Standard Solution for Impurity Determination
General Method for Colorimetric Determination of Chemical Reagents
GB 605
GB1723
GB2914
GB2917
GB 7139
3 Technical requirements
Determination of coating viscosity
Determination of volatile matter (including water) in polyvinyl chloride resin Test method for thermal stability of polyvinyl fluoride - Congo red method and PH method Determination of fluorine in fluoroethylene homopolymer and copolymer 3.1 Appearance: White or slightly light-colored loose granules or powder (loose lumps not larger than 30mm are allowed), without visible impurities. 3.2 The perfluoroethylene resin used in coatings shall meet the requirements of the following table: Item
Dissolution time, min
Viscosity (flow time of coating-4 viscosity cup), s
Transparency, cm
Chroma (Pt-Co), No.
Heating loss, %
Chlorine content, %
Ash content, %
Iron content, %
Thermal stability, min
Transparent particles of paint film
Test method
14. 0~20.0
Qualified products
14.0~28. 0
61.0~~65.0
The reagents and water used in this standard, unless otherwise specified, refer to analytical pure reagents and distilled water or water of corresponding purity. 4.1 Determination of dissolution time
4.1.1 Reagents and solvents
Approved by the Ministry of Chemical Industry of the People's Republic of China on June 28, 1991 and implemented on January 1, 1992
Acetone (GB686);
Toluene (GB684);
Ethyl acetate (HG3-1466);
HG 2002-91
Mixed solvent: The ratio of acetone, toluene and butyl acetate is 35+30+35 (mass ratio). d.
4.1.2 Determination procedure
Weigh 10g of the sample (accurate to 0.1g) in a 250mL conical flask with a ground stopper, and add 90g (about 110mL) of the mixed solvent. Put the stopper in place, and shake for 1min every 10min at a determination temperature of 20~25℃ until the resin is completely dissolved. Turn the conical flask upside down and observe the thin layer of solution flowing down the wall of the flask. There should be no colloid. Note the required time (min), which is the dissolution time. Save the obtained sample solution for viscosity measurement. 4.2 Determination of viscosity
4.2.1 Instrument
a. Tu-4 viscosity cup;
b. Stopwatch, accurate to 0.1s.
4.2.2 Determination conditions
The measurement temperature is 25±1℃.
4.2.3 Determination procedure
Use the sample solution obtained by measuring the dissolution time to measure according to the method specified in Article 3, Chapter 2 of GB1723. Save the obtained sample solution for transparency and chromaticity measurement. 4.3 Determination of transparency
4.3.1 Instrument and device
Colorimetric tube or colorless flat-bottomed test tube, diameter 25mm, height about 350mm; a.
b. Wooden box, as shown in the figure.
HG 2002—91
Diagram of transparency measurement device
1—colorimetric tube, 2—ground glass, 3—wooden box A partition is installed in the middle of the wooden box 130mm away from the top cover. A circular hole with a diameter of 50mm is opened in the center of the board. A piece of ground glass is covered on the hole. A small black dot with a diameter of 5mm is painted with matte black paint on the glass aligned with the center of the circular hole. A circular hole with a diameter of 30mm is opened in the center of the top cover of the box, and a 25W bulb is installed on the bottom. The bulb is about 60mm away from the middle partition. The inner wall of the box is completely painted matte black with matte black paint. 4.3.2 Measurement procedure
Insert the colorimetric tube into the box from the opening on the top of the box, place it on the ground glass, so that the small black dot is just in the center of the bottom of the colorimetric tube, turn on the light switch, slowly inject the sample solution after the viscosity is measured into the colorimetric tube, and observe carefully until the small black dot is invisible. The height of this solution is measured, which is the transparency.
4.4 Determination of chromaticity
4.4.1 Reagents and instruments
Standard platinum-cobalt colorimetric solution, prepared according to GB605; a.
Colorimetric tube, 50ml, with stopper.
4.4.2 Determination procedure
Inject the sample solution after viscosity determination into the colorimetric tube to the 50mL mark. Compare with the standard colorimetric solution of the same volume under the same conditions.
4.5 Determination of heating loss
Determine according to GB2914. The temperature of the electric constant temperature drying oven is controlled at 75±2℃, the sample heating time is 2h, and the sample is cooled to room temperature in the dryer and weighed.
4.6 Determination of chlorine content
4.6.1 Determination procedure
Determine according to method B in GB7139 and Appendix C.
HG 2002-91
Appendix C can also be replaced by the following steps: After the material in the beaker is cooled, use a microburette to accurately add c(AgNO): 0.1mol/l. 10.00mL of silver nitrate standard solution, add 2mL of dimethyl phthalate, add 1-2mL of ammonium ferric sulfate indicator, and titrate with c(NH.CNS) = 0.1mol/L ammonium thiocyanate standard solution under constant stirring until the solution turns slightly orange-red as the end point. 4.6.2 Expression of results
The difference between the single measurement value and the arithmetic mean value shall not exceed ±0.4%, and the arithmetic mean value of the two measurements shall be taken as the measurement result. 4.7 Determination of ash content
4.7.1 Instruments and equipment
Analytical balance, sensitivity 0.0001g;
Porcelain crucible, 50mL;
High temperature furnace,
d. Electric furnace.
4.7.2 Determination procedure
Weigh 2-3g of sample (accurate to 0.0002g) in a constant-weight porcelain, first carbonize on an electric furnace until smokeless, then transfer to a high-temperature furnace and burn at 800-900℃ to constant weight. Save the ash residue for determination of iron content.
4.7.3 Calculation and expression of results
The percentage of ash (X1) is calculated according to formula (1): X1=m=2mo×100
Wherein: mo-
mass of the porcelain crucible with constant weight, g
m1——mass of sample and porcelain, g
m2——mass of ash and porcelain crucible after calcination, g. 4.8 Determination of iron content
4.8.1 Reagents and instruments
Hydrochloric acid (GB622) 20% solution;
Nitric acid (GB626) 20% solution;
Sulfuric acid (GB625) 20% solution;
Ammonium thiocyanate (GB660) 10% solution,bZxz.net
Iron standard solution (1mL contains 0.00001g iron), prepared according to GB602 and diluted 10 times: microburette, 2mL,
Colorimetric tube, 50mL.
4.8.2 Determination procedure
(1)
Add 5~10mL20% hydrochloric acid to the ash after the ash content is determined, dissolve the ash residue, and then transfer it to a 250mL volumetric flask, dilute to scale with water, shake well, draw 10mL from it, inject it into a 50mL colorimetric tube, add 0.5mL20% nitric acid solution, 0.5mL20% sulfuric acid solution and 5mL10% ammonium thiocyanate solution, and dilute to scale with water. In another colorimetric tube of the same size, add the same amount of reagents and solutions as before, dilute to scale with water as a blank, and drip the iron standard solution from the microburette into the blank colorimetric tube until the colors of the solutions in the two colorimetric tubes are the same. 4.8.3 Calculation and expression of results
The percentage of iron in the resin (X2) is calculated according to formula (2): 240
HG 2002--91
_VX0. 000 01
X 100:
m×250
Wherein: V is the volume of the iron standard solution consumed in titration, mL; the mass of the sample taken when determining the carbon content, g. m
4.9 Determination of thermal stability
4.9.1 Instruments and materials
V×0. 000 01X25 ×100
General laboratory instruments and instruments and materials specified in GB2917. 4.9.2 Determination procedure
Weigh about 5g of the sample in a beaker, add water at a temperature of 50±10℃ in a ratio of 1+20, stir with a glass rod for 2~3min, filter and dry, heat in an electric constant temperature drying oven at 75±2℃ for 2h, and cool to room temperature. Then determine according to GB2917 Chapter 4 Method A---Congo Red Method, and control the temperature at 90±1℃. 4.10 Determination of transparent particles in paint film
4.10.1 Test materials
Glass sheet, size: 30mm×90mm×3mm. 4.10.2 Determination procedure
Immerse the clean glass sheet vertically in the solution after the viscosity is measured at a slow and uniform speed, stay for 30s, take it out at the same speed, place it in a clean place to drip dry, and observe the transparent particles against the light after the surface is dry (about 3min). 5 Inspection rules
5.1 This product shall be inspected by the quality inspection department of the manufacturer. The manufacturer shall ensure that the perchloroethylene resin shipped from the factory meets the requirements of this standard. 5.2 The user has the right to inspect and accept the received products in accordance with the provisions of this standard. 5.3 The resin obtained from one drying is regarded as a batch, and samples are taken from 20% of the total number of bags of each batch of resin. The total amount of samples taken from each batch shall not be less than 150g.
5.4 Mix the samples evenly, put them in a dry and clean glass bottle (or plastic film bag) with a ground stopper, and label them with the product name, batch number, etc. for measurement. 5.5 Ash content, iron content and thermal stability are type inspection items. Under continuous normal production conditions, random inspections are conducted 1 to 2 times a month. However, when restarting production after stopping, each batch shall be inspected until the three indicators of the resin produced for a week meet the requirements of this standard, and then random inspections can be conducted under normal conditions.
5.6 When determining the chlorine content, it is allowed to take mixed samples of the resin obtained by single chlorination and batch drying. The measured results represent the fluorine content of each batch of resin in the single chlorination.
5.7 If one of the indicators in the test results does not meet the requirements of this standard, samples should be taken from double the number of sampling bags of the same batch of resin for re-testing of the indicator. If the re-test results still do not meet the requirements of this standard, the entire batch of products cannot be processed as products of that grade. 6 Marking, packaging, transportation and storage
6.1 Each batch of resin leaving the factory should be accompanied by a quality certificate in a certain format. Each bag of resin should have a certificate of conformity, which should indicate: manufacturer name, product name, grade, batch number, net weight, etc. The packaging bag should have obvious markings indicating the manufacturer name, product name, and trademark. 6.2 This product can be packaged in cloth bags or polypropylene woven bags lined with plastic film, with a net weight of 15kg or 20kg per bag. 6.3 This product should be covered during transportation to prevent sun and rain. 6.4 This product should be stored in a dry and clean warehouse to prevent exposure to sunlight or moisture. 241
Additional Notes:
HG200291
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Polyvinyl Chloride Resin Product Sub-Technical Committee of the National Plastic Standardization Technical Committee. This standard was drafted by the Electrochemical Plant of Shanghai Chlor-Alkali General Plant. The main drafters of this standard are Xu Demin and Bao Aili. From the date of implementation of this standard, the former standard HG2-344-66 "Perchloroethylene Resin (for Coatings)" issued by the Ministry of Chemical Industry of the People's Republic of China will be invalid.
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