Some standard content:
Chemical Industry Standard of the People's Republic of China
Lead Stearate
(Light)
Main Content and Applicable Range
HG 2337-92
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of lead stearate. This standard is applicable to lead stearate obtained by saponification of industrial stearic acid and double decomposition of lead salt. The product is mainly used as stabilizer and lubricant for vinyl chloride
2 Reference Standards
GR 601
GB 6e3
GB 617
Chemical Reagents Preparation of Standard Solutions for Titration Analysis (Volume Analysis) Preparation of Preparations and Products Used in Test Methods Chemical Reagents
General Method for Determination of Melting Point of Chemical Reagents GB 6678
(B 6682
3 Technical requirements
General rules for sampling of chemical products
Specifications for laboratory water
3.1 Appearance: white powder, with obvious mechanical properties. 3.2 Technical indicators
Lead stearate shall meet the requirements of the following table:
Lead content, %
Free acid (calculated as stearic acid),
Heating loss, %
Melting point, c
Fineness (passing through c.075mm sieve), %
Test method
Superior product
27. 5±0. 5
103~110
100--116
Qualified product
27. 5-1. 5
98~110
The standard titration solutions, preparations and products used in this standard, unless otherwise specified, shall be prepared in accordance with the provisions of GB601 and GB 603.
The water used in this standard, unless otherwise specified, shall comply with the specifications of Grade 3 water in GB6682. 4.1 Appearance determination
Visual inspection.
4.2 Determination of lead content
4.2.1 Principle of the method
Approved by the Ministry of Chemical Industry of the People's Republic of China on June 1, 1992 and implemented on July 1, 1993
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HG 2337—92
The sample is decomposed into stearic acid and the corresponding lead salt in strong acid, and the lead content is determined by complexation with disodium ethylenediaminetetraacetic acid standard titration solution. 4.2.2 Reagents and solutions
Nitric acid (GB626) solution: 10+14:
Ammonia (GB631) solution: I+1)
Acetic acid-sodium acetate buffer solution: pH=5.5: Disodium ethylenediaminetetraacetic acid (EDTA) standard titration solution c(EDTA)=0.02mol/L Cresol orange indicator, 2g/l.
4.2.3 Analysis step
Weigh 0.2g sugar sample (accurate to 0.0001g) and place it in a 250ml conical flask, add 5ml nitrate solution and 2ml water, place it on an electric stove and heat it slightly until the oil layer becomes transparent, then stop heating. After cooling, neutralize it with ammonia solution to pH=5~6, add 10ml acetic acid-sodium acetate grade flushing solution, use 5 drops of phenol orange indicator solution, and titrate it with disodium ethylenediaminetetraacetic acid standard titration solution until the purple-red color of the solution changes to yellow. This is the final result. 4.2.4 Analysis Expression of results
The mass percentage of lead is calculated according to formula (1): =
Wherein: c-
actual concentration of disodium ethylenediaminetetraacetic acid standard titration solution, ml/L; volume of disodium ethylenediaminetetraacetic acid standard titration solution consumed, mL; mass of sample·g1
-the mass of 0.2072
lead equivalent to 1.00mL disodium ethylenediaminetetraacetic acid standard titration solution c(EDTA)=1.000mol/1.), expressed in grams.
4.2.5 Allowable error
The difference between two parallel determination results shall not exceed 0.2%. The arithmetic mean shall be taken as the lead content. 4. 3 Determination of free acid
4.3.1 Reagents and solutions
95% sodium hydroxide standard titration solution: c(Na0H)-0.05 mol/L: phenol indicator solution: 10 g/L,
4.3.2 Instrument
5 ml micro titration tube.
Analysis steps
Weigh 2g of the sample (accurate to 0.01g) and place it in a 250L flask, add 50mL of ethanol, shake for 10min, and filter. Wash the remaining residue twice with 30mL of ethyl acetate, filter dry, collect the filtrate and washing liquid, add 5 drops of phenol indicator solution, and titrate with sodium hydride standard solution until the solution turns slightly red and remains unfaded for 30%, which is the end point. At the same time, use equal amount of ethanol to do a blank test. 4.3.4 Expression of analytical results
The mass percentage of free acid 2 is calculated according to formula (2): C(VV,3X0.271
Wherein: c-
-actual concentration of sodium hydroxide standard titration solution, mol/L; volume of sodium hydroxide standard titration solution consumed, ml.; V--volume of sodium hydroxide standard titration solution consumed in blank, mL: 00
-mass of sample + name:
0.271-mass of industrial stearic acid equivalent to 1.00mL sodium hydroxide standard titration solution [c(NaOH)-1.000moi/L), expressed in grams.
4.4 Measurement of heating loss
4.4.1 Instruments and equipment
Weighing bottle: diameter 50mm, height 30mm; wwW.bzxz.Net
b. Electric heating temperature drying oven:
. Lower desiccator: contain appropriate desiccant, 4.4.2 Analysis steps
HG 2337-92
Adjust the electric constant temperature drying oven to 90±3, place the weighing bottle in the electric constant temperature drying oven and dry it to constant weight. Weigh 8g of the sample (accurate to 0.0001g) in the weighing bottle that has been weighed to a constant weight, place the weighing bottle around the mercury ball of the thermometer in the drying oven, open the weighing bottle cover, and turn it over next to the weighing bottle. When the temperature rises to 90±3℃, keep it for 2h, then cover the weighing bottle and move it into the desiccator, cool it for 30min, and weigh it. 4.4.3 Expression of analysis results
Heating weight loss percentage 2. Calculate C
according to formula (3) In the formula; n,
- weight of weighing bottle and sample before drying, R1
weight of weighing bottle and sample after drying P
weight of sample.g.
4.5 Determination of melting point
Determination shall be carried out in accordance with the provisions of GB617, and the temperature at which the sample is molten shall be the melting point. 4.6 Determination of fineness
4.6.1 Apparatus and equipment only
Test sieve (GB6003): $75mm×251mm/0.075mm; b
Soft brush, about 35mm long and 20mm wide; c. Industrial heptad,
1. Electric constant temperature drying box.
4.6.2: Analysis steps
Weigh 5g of the sample (accurate to 0.1g), place it in a 25mm conical flask, add 80ml of clarified unprocessed ethanol, shake the spoon, and then pour it into the test sieve for sieving. Take clarified industrial ethanol to rinse the sample in the flask and on the test sieve and sieve it. Put the test sieve together with the residual sample in the sieve in an electric constant temperature drying oven, dry it at 85-90℃ for 30min, take it out, and then gently brush it with a soft brush to make the wire sample left on the test sieve continue to sieve. Finally, weigh the sieve residue that cannot be sieved (accurate to 0.0001g). 4.6.3 Expression of analysis results
Fineness (passing 0.075mm sieve) mass percentage is calculated according to formula (4);:
In the formula, m—mass of sieve residue.;
mass of sample g.
5 Inspection rules
m-m1x100
5.1 This product is inspected by the quality supervision department of the manufacturer. The manufacturer guarantees that the products leaving the factory meet the requirements of this standard and shall be accompanied by a quality certificate in a certain format.
5.2 The consignee has the right to inspect and accept the received products in accordance with the provisions of this standard. 5.3 The product is considered as a batch based on the target production volume.
5.4 Determine the sampling number according to Table 2 in GB6678. For sampling, use a dry and clean sampling tube with both upper and lower hooks to take samples. The total sampling volume shall not be less than HG2337-92
250g·After mixing, divide it into two bottles, one bottle is sent to the quality inspection department for inspection, and the other bottle is kept for backup. 5.5 If any of the indicators in the inspection results do not meet the requirements of this standard, the samples shall be re-sampled in two packaging containers. If the re-inspection results still do not meet the requirements of this standard, the entire batch of products shall be unqualified. 5.6 When the supply and demand parties have a dispute over the product quality, they can agree to select an arbitration unit. The arbitration unit shall conduct arbitration inspections in accordance with the provisions of this standard.
6 Marking, packaging, transportation and storage
6.1 The product packaging bag shall be painted with a firm and clear mark, including the manufacturer's name, product name, standard code, trade name, production date, net weight, etc.
6.2 The product is packed in a sealed and clean package such as an iron barrel, wooden barrel, or woven bag lined with plastic film. Each bag (barrel) must be accompanied by a product certificate, including the manufacturer's name, product name, standard number, grade, index, batch number, inspection period, inspector, etc. 6.3 The product shall not come into contact with acid, alkali or other corrosive substances during transportation to prevent deterioration. 6.4 The product shall be stored in a cool, ventilated and dry warehouse for a period of 1 year. Additional remarks
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry. This standard is under the jurisdiction of the Shanxi Chemical Research Institute. This standard was drafted by Nanjing Jinling Chemical Plant and Shanxi Chemical Research Institute. The main drafters of this standard are Wei Liangjing and Guo Yanping. From the date of implementation of this standard, the former Ministry of Chemical Industry Standard HG2-1204-79≤Lead Stearate (Light) will be invalid.
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