This standard specifies the determination of the solubility of water-soluble dyes in water at 25°C (without preheating). This method does not measure absolute solubility. GB/T 3671.2-1996 Determination of cold water solubility of water-soluble dyes GB/T3671.2-1996 Standard download decompression password: www.bzxz.net

GB/T 3671.21996
This standard is a comprehensive revision of GB/T3671-83 "Determination of solubility of water-soluble dyes - Decompression filtration method" according to ISO 105-Z09:1995 (Determination of water solubility of water-soluble dyes) of the International Organization for Standardization. It is equivalent to the international standard in terms of technical content and writing rules. ISO 105-Z09 stipulates two specifications of filter paper to be used. Because there is no supply of the same type of filter paper in China, the quality indicators of filter paper in my country are not completely consistent with the filter paper specifications in the international standard. During the drafting of this standard, it was verified and compared that the use of domestic rapid qualitative filter paper of a certain specification can achieve satisfactory results. Appendix A is a suggestive appendix.
This standard will replace GB/T3671-83 from the date of entry into force. This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the technical jurisdiction of Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry, and this standard is under the technical jurisdiction of Shanghai Dyeing Industry Bureau. The main drafters of this standard are Hu Changtu, Su Zhuping and Ling Peijiang. This standard was first issued on May 14, 1983. GB/T3671.2-1996
ISO Foreword
ISO (International Organization for Standardization) is a worldwide federation of national standardization bodies (ISO member bodies). The formulation of international standards is carried out through ISO technical committees. Each member body has the right to send representatives to participate in the committee if it is interested in the subject of the established technical committee. Related governmental or non-governmental international organizations may also participate in the work. ISO and the International Electrotechnical Commission IEC work closely on relevant electrotechnical standards. Draft international standards adopted by the technical committee should be circulated to the member groups for voting before being approved as international standards. At least 75% of the member groups vote or approve the international standard ISO105-Z09 is developed by ISO/TC38 Textile Technical Committee, SC1 Textile Color Fastness and Dye Test Technical Committee.
ISO105 published from 1978 to 1985 is divided into thirteen parts, each part specifies a Each part is indicated by a letter (e.g. *Part A\) and the date of publication. Each part contains several chapters, each of which is designated by its own letter and two-digit number (e.g. \Part A01\). These sections are now republished in separate documents, each of which is called a "part", but retains their original letter designation. A complete list of parts is given in ISO105-A01.
Appendix A of this standard is for reference only.
1 Scope
National Standard of the People's Republic of China
Determination of cold water solubility of water-soluble dyes
Determination of cold water solubllftyof water-soluble dyes
GB/T 3671.21996
Idt IsO.105-z09.1995
Replaces GB/T 3671-83
This standard specifies the determination of the solubility of water-soluble dyes in 25°C water (without preheating). This method does not measure the absolute solubility.
Note: Appendix A lists several factors that may affect the test results. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised. Parties using this standard should explore the possibility of using the new versions of the following standards. GB/T6682-92 Specifications and test methods for analytical laboratory water (eqvISO3696,1987) ZBN64001-87 Laboratory glassware - beaker ZBN64002-87 Laboratory glassware narrow-necked flask 3 Preparation
Prepare a set of dye solutions of known concentration including solubility limit at 25℃, then filter the solution with filter paper using a heated Buchner funnel at this temperature, and determine the solubility limit by visually inspecting the residue on the filter paper and measuring the filtration time. 4 Filling and reagents
4.1 Beaker
Capacity is 400 mL.
4.2 Heating bath
A thermostatically controlled heating bath with an electromagnetic stirrer, the temperature is controlled to 25℃±2℃, the stirring rod is 40mm long, the true diameter is 6mm, and the stirring speed is 500~~600 r/min.
4.3 Buchner funnel
Heated Buchner funnel made of glass, stainless steel or porcelain, with an inner diameter of 72 mm, a volume of not less than 200 mL, more than 100 holes, evenly distributed, and a total area of ​​not less than 200 mm2. 4.4 Constant temperature control device
A constant temperature control device with a circulation pump to adjust the temperature of the Buchner funnel. 4.5 Vacuum device
4.5.1 Filter bottle, with a volume of 1 to 2 L.
4.5.2 Piston pump or membrane pump
A piston-type membrane pump that can produce a high vacuum degree, with a vacuum degree of at least 50 kPs. Guohao Technical Supervision Bureau approved on August 22, 1996, implemented on March 1, 1997
CB/T 3671,2-1996
4.5.3 Pressure regulating device used to adjust and maintain the specified vacuum degree, preferably connected to a vacuum gauge. 4.6 Stopwatch
Used to measure the filtration time.
4.7 Rapid qualitative filter paper
The diameter is 70tmm±2mm.
Note: The filter paper should meet the following requirements: Under a vacuum degree of 3 kPa, the time for double reading reduction with 200 mL of 85°C~95°C water should be 5~7 B. The type of filter paper used and the name of the manufacturer shall be indicated in the test report. 4.8 Water
The water used as dye dissolving agent shall comply with the provisions of Grade 3 water in GB/T6682--92. Generally, 200 mL of water is used for dissolving. If more water is added to the solution, the amount added must be stated in the report together with the cold water solubility value of the dye.
Note: The volume change caused by temperature can be ignored. 5 Preparation of solution
5.1 The concentration level of the prepared dye solution will be selected according to the expected cold water solubility limit of the dye. Estimated solubility range
1 g/L~10 g/L
10 g/L~50 g/L
50 g/L~100 g/L
100 g/L and above
For dyes approaching the solubility limit, the solubility increases by 1 g/h
10 g/L
5.2 Sprinkle a known weight of the dye under stirring in a beaker (4.1) containing 200 mL of water (4.8) in a thermostatically controlled heating bath adjusted to 25°C ± 2°C. The total stirring time is 2 min or 5 min. Immediately filter the solution (see Chapter 6). The stirring time must be stated in the test report together with the cold water solubility limit. Repeat this operation for each concentration of the dye under test. 6 Filtration of the falling solution
To avoid the effects of sudden temperature changes, the apparatus for filtering the hot solution must be heated to the same temperature as the falling solution under test. A jacketed Büchner funnel is ideal, but satisfactory results can also be obtained by using a preheated funnel. The funnel is immersed in water or placed in an oven or water preheated to the test temperature is passed through the filtration apparatus before the test. When the preheating method is used, the amount of water used for preheating is determined by the amount of water that can heat the filter funnel to the same temperature, regardless of the geometry of the load and the surrounding conditions. In the case of preheating, more care should be taken than when using a jacketed full funnel. The test solution and filter must be filtered immediately after being removed from the heating medium. 6.1 Preheat the Büchner funnel (4.3) to the 25°C dissolution temperature (see 4.4) and maintain this temperature throughout the filtration operation. 6.2 Before filtering, moisten the double-layer filter paper (4.7) in the Buchner funnel with at least 50 mL of water at 25°C. 6.3 Adjust the vacuum to 3~4 kPa, which is equivalent to a vacuum of 300~400 mm of water column. 6.4 Filter the dye solution (5.2) at 25±2°C and measure the filtration time with a stopwatch (4.6). 6.5 If the dye solution cannot be filtered within 2 min under the specified vacuum, it can be filtered under full vacuum, but the time shall not exceed 2 min (see 4.5.2).
6.6 After the solution is filtered, open the vacuum and filter for dehydration for 1 min. 6.6.1 Before rating, let the filter paper dry completely at room temperature. 7 Rating
7.1 Visually evaluate the dry filter paper that has been filtered through various known dye solutions. The concentration at which leakage can be seen on the filter paper is taken as the cold water solubility limit. Sometimes, the paper can be gently rubbed with the fingertips to find the residue that is not easy to see. GB/T 3671.2-1996
7.2 Filtration time can also be used as a basis for further rating. When the filtration time jumps with the increase of dye liquid concentration, it means that the cold water solubility limit has been exceeded. www.bzxz.net
Test report
The test report should include the following contents:
a) State the number and year of this standard:
b) The full name of the dye to be tested:
c) The type of filter paper used and the name of the manufacturer d) The stirring time when preparing the dye solution (2 min or 5 min) (see 5.2); e) The solubility limit of cold water (25°C) expressed in g/L: () The corresponding filtration time (see 7.2);
8) Special circumstances in the test or assessment process; h) Differences from this method (for example, the amount of solvent is not 200 mL, etc.) GB/T 3671.21996
(Appendix of Tips
Causes of Results
For many years, the above test method has obtained good test results. However, it should be pointed out that if the test conditions are slightly different from the provisions of this method, the results will be affected. a) Use filter paper of other specifications. The selection of the leaching paper must be considered comprehensively based on the permeability and actual conditions. b) When water with different hardness or electrolytes is used
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