Some standard content:
Chemical Industry Standard of the People's Republic of China
Subject Content and Scope of Application
HG 2231-91
This standard specifies the product model, technical requirements, test methods, inspection rules and requirements for marking, packaging, transportation and storage of petroleum resin (PR).
This standard applies to aromatic petroleum resin produced by catalytic polymerization using the carbon nine fraction of petroleum cracking as raw material. 2 Reference standards
GB2294
GB2295
GB2895
GB4318
GB 6678
GB 6679
Preparation of standard solution for titration analysis (volumetric analysis) of chemical reagentsDetermination method for softening point of coal tar pitch
Determination method for ash content of coal tar pitch
Determination of acid value of unsaturated polyester resin
Determination method for pH value of solid coumarone-benedictory resinGeneral rules for sampling of chemical products
General rules for sampling of solid chemical products
GB 12007. 1
3 Product model
Determination method for color of epoxy resin
Gardner colorimetry
This product is classified according to its raw material pretreatment process and softening point. 3.1 Raw material pretreatment process
Raw material pretreatment process is divided into two categories:
PR1-distillation
PR2-crude distillation
3.2 Softening point
Softening point is represented by Arabic numerals, and its code and temperature range are shown in Table 1. Table 1 Softening point code and range
4 Technical requirements
4.1 Appearance
Light yellow to brown solid.
Softening point, C
>80～90
>90～100
>100～110
Approved by the Ministry of Chemical Industry of the People's Republic of China on December 27, 1991428
Softening point, ℃
>110～120
>120～130
>130～140
Implemented on July 1, 1992
4.2 Physical and chemical properties
The physical and chemical properties shall conform to the requirements of Table 2 and Table 3. PR 1-90
Softening point, C
Sample; Toluene=1:1
Color number
Sample: Toluene=1:8.5≤
Acid value, mgK()H/g
Ash content, %
Bromine value, gBr/100g
Softening point,
Color number
Acidity (pH)
Ash content, %
Resin: Toluene=11
Superior product
>80～90
HG 2231—91
PR1 Physical and chemical properties
PR 1-100
>90～100
PR1-110
Excellent!
>100～110
PR 1-120
Qualified
>110～120
PR1-130
>120～130
PR 1-140
>130～140
0.10.51.00. 10.51.00.10.51.00.10.51.00.10.51.00.1
According to user needs, negotiate and determine
Table 3 PR2 physical and chemical properties
PR 2-90
Qualified products
>80～90
Resin:toluene=1:8.5
5Test method
Appearance determination
Visual inspection.
5.2 Determination of softening point
The softening point shall be determined by the method specified in GB2294. 5.3 Determination of color
PR 2-100
Quality product
>90～100
PR 2-110
Quality product
>100～110
PR2-120
Quality product
>110～120
PR 2-130
Quality product
>120～130
The determination is carried out by the method specified in GB12007.1. The resin is dissolved in toluene to form a uniform solution. The mass ratio of the sample to toluene is 1:1 or 18.5. The mass ratio of the sample to toluene should be 1:1 during arbitration.5.4 Determination of acid value
The determination is carried out by the method specified in GB2895. 5.5 Determination of ash content
The method specified in GB2295 shall be used for determination. 5.6 Determination of pH
The method specified in GB 4318 shall be used for determination. 5.7 Determination of bromine value
HG 2231--91
The method specified in Appendix A of this standard shall be used for determination. 6 Inspection rules
6.1 The products uniformly mixed by continuous production on the same production line, under the same raw material ratio and the same process conditions shall be a batch, and each batch shall not exceed 5 days. The batch production by intermittent production shall be a batch of each kettle. 6.2 The sampling unit shall be in accordance with the provisions of GB6678, and the sampling method shall be in accordance with the provisions of GB6679. The sampling volume of each batch of products shall not be less than 5 kg.
6.3 Each batch of products must be inspected by the quality inspection department of the production, and it shall be ensured that all products leaving the factory meet the various technical requirements specified in this standard.
6.4 In this standard, softening point, color, acid value, pH value are factory inspection items, ash content and bromine value are random inspection items, and random inspection is conducted every three batches. Type inspection shall be carried out in accordance with the provisions of 6.6.1 of GB1.3. 6.5 If the user unit needs to inspect the received products, it shall be carried out in accordance with the provisions of this standard. Acceptance inspection shall be carried out within three months of receiving the products.
6.6 When a certain inspection result does not meet the requirements of this standard, samples shall be taken from twice the amount of packaging of the batch of products, and the unqualified items shall be re-inspected, and the grade shall be determined based on the re-inspection results. 6.7 When the supply and demand parties have objections to the product quality, the two parties shall negotiate to resolve the dispute or the statutory quality inspection department shall conduct arbitration. 7 Marking, packaging, transportation, storage
7.1 Marking
Each batch of products shall have a quality inspection report. Each package shall have a clear and firm mark indicating the product name, trademark, model, grade, net weight and production unit. bzxz.net
7.2 Packaging
This product should be packed in woven bags lined with plastic bags, with a net weight of 25kg, 40kg, and 50kg per bag. Each package should be accompanied by a certificate of conformity, indicating the batch number, production date, and the number of this standard. 7.3 Transportation
This product should be protected from sunlight and rain during transportation. This product is non-dangerous.
7.4 Storage
This product should be stored in a ventilated, cool, and dry place, with a storage period of 1 year. If the storage period exceeds the limit, it can be retested according to the provisions of this standard. If the retest results meet the requirements of this standard, it can still be used. 430
Method".
HG 2231—91
Appendix A
Test method for bromine value of petroleum resin (PR)
(Supplement)
This appendix adopts the international standard ISO3839—78 "Petroleum products and commercial fatty olefins—Determination of bromine value—Potentiometric titration" A1 Terminology
Bromine value—The mass of bromine in grams that reacts with 100g of sample under certain test conditions. A2 Method summary
Dissolve the sample in carbon tetrachloride, add glacial acetic acid and excess bromine standard titration solution at room temperature, reduce the excess bromine with potassium iodide, and then titrate the free iodine with sodium thiosulfate standard titration solution to calculate the amount of bromine that reacts with the sample. A3 Reagents and solutions
A3.1 Carbon tetrachloride (GB688).
A3.2 Glacial acetic acid (GB 676).
A3.3 Bromine standard titration solution: c(1/6KBrO)=0.5mol/L. Prepare and calibrate using the method specified in GB601. A3.4 Sodium thiosulfate standard titration solution: c(Na2S,O.)=0.1mol/L, prepare and calibrate using the method specified in GB 601. A3.5 Potassium iodide solution: Dissolve 15.0g potassium iodide in water and dilute to 1L. A3.6 Starch indicator solution: 5g/L starch aqueous solution, prepare using the method specified in GB603. A4 Instruments
A4.1 Erlenmeyer flask: 50mL.
A4.2 Iodine volume flask: 500mL.
A4.3 Measuring cylinder: 50mL, 100mL.
A4.4 Burette: 50mL, 10mL.
A4.5 Analytical balance: sensitivity 0.1mg.
A4.6 Pan balance: sensitivity 0.1g.
A5 Analysis steps
A5.1 Weigh about 0.4g of powdered sample, accurate to 0.0001g, and put it into a 500mL iodine volumetric flask. Add 10mL of carbon tetrachloride to dissolve it, then add 50mL of glacial acetic acid and place it in a water bath at 25±1℃ away from sunlight. While shaking, add 6~7mL of bromine standard titration solution at a rate of 1~2 drops per second. After the addition is completed, quickly cover the bottle with a stopper and seal the bottle with 2mL of potassium iodide solution. After oscillating in a water bath for 40~50s, loosen the bottle stopper to allow the potassium iodide solution to flow into the bottle. Rinse the bottle stopper with 3mL of potassium iodide solution. After covering the bottle stopper and oscillating vigorously for 1min, rinse the bottle stopper, bottle mouth and inner wall with 100mL of water, and then back-titrate with sodium thiosulfate standard titration solution. When approaching the end point, add 1mL of starch indicator solution and continue titration. The titration end point is when the color disappears and does not return to color within 1min. Record the amount of sodium thiosulfate standard titration solution used.
A6 Expression of analysis results
The bromine value of the sample is calculated according to formula (A1):
X=(GVt-c,V2)×0. 079 92
（A1）
Wherein: X-
Br value of the sample, gBr/100g;
HG2231-91
Actual concentration of bromine standard titration solution, mol/L; Vi
-Amount of bromine standard titration solution, mL
C2Actual concentration of sodium thiosulfate standard titration solution, mol/L; V. Amount of sodium thiosulfate standard titration solution, mL; m
Mass of the sample, g;
0.07992--The mass of bromine in grams equivalent to 1.00mL sodium thiosulfate standard titration solution (c(NazS,O,)=1.000mol/L).
The difference between the results of two parallel determinations shall not exceed 2gBr/100g. The results shall be expressed as the arithmetic mean and retained to one decimal place. Additional Notes:
This standard was 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 Plastic Resin Products Branch (SC4) of the National Plastic Standardization Technical Committee. This standard was drafted by Anshan Chemical Plant No. 1 and Qingdao Qinbo Chemical Plant. The main drafters of this standard are Cao Fengxin, Gong Xiangqin, Zhao Tingshu, Yuan Yushu, Zhang Yun, Zhang Kezhi, Wu Xiaobin and Liu Jie. 132
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