Purified terephthalic acid for industrial use (SH/T1612.1-2005) This standard specifies the technical requirements, test methods, inspection rules, packaging, marking, transportation, storage and safety requirements of PTA for industrial use.
This standard is applicable to industrial PTA made from petroleum p-xylene by oxidation refining. This product is mainly used as raw material for producing polyester chips, long and short polyester fibers and chemical products.
Molecular formula: C8H6O4
Simple structure:
Relative molecular mass: 166. 13 (according to international relative atomic mass 200 1). The clauses in the following documents constitute the clauses of this standard by referring to this standard. All subsequent modifications (excluding errata) or revisions of dated reference documents are not applicable to this standard. However, parties who have reached an agreement according to this standard are encouraged to study whether the latest versions of these documents can be used. For undated reference documents, the latest edition is applicable to this standard.
The expression method and rebellious method of GB/T 1250 limit value
GB/T3 134 method for color determination of liquid chemical products (hazen unit-platinum cobalt color number)
General rules for sampling chemical products
General rules for sampling solid chemical products
GB/T753 1 determination of ash in organic chemical products
SH/T1612.2-1995 Determination of acid value of purified terephthalic acid for industrial use
SH/T1612.3-1995 Determination of metal content in purified terephthalic acid for industrial use-Atomic absorption spectrophotometry.
SH/T1612.4-1995 Purified terephthalic acid for industrial use-Determination of water content-Karl Fischer volumetric method.
SH/T1612.5-1995 Determination of titanium content in purified terephthalic acid for industrial use-Diantipyrine methane spectrophotometric method.
Determination of p-carboxybenzaldehyde and p-toluic acid in purified terephthalic acid for industrial use by HPLC
SH /T 1687-2000 Determination of p-carboxybenzaldehyde and p-toluic acid in purified terephthalic acid for industrial use (HPCE)
SH /T 16 12.8-2005 Determination of particle size distribution of purified terephthalic acid for industrial use-Laser diffraction method
SH/T1612.10-2005 Determination of t* value of purified terephthalic acid for industrial use, colorimetric method.
Table of technical requirements and test methods
PTA for industrial use shall meet the technical requirements in Table 2. 1
2. 1 quality indicators and inspection methods
Test method of project index
First-class products
Appearance white powder Visual inspection of white powder A
Acid value, mg KOH/g 675 2 675 2 sh/t1612.2.
P-carboxybenzaldehyde mg/kg ≤ 25 25 sh/t1612.7 (arbitration method), SH/T 1687.
Ash content, mg/kg ≤ 815 GB/t7531.
Total amount of heavy metals (molybdenum, chromium, nickel, cobalt, manganese, titanium and iron), mg/kg ≤ 510sh/t12.3, SH/T 16 12.5.
Iron, mg/kg ≤12sh/t1612.3.
Water content,% (mass fraction) ≤ 0.20.5 sh/t1612.4.
5g/ 100mL DMF chromaticity b, platinum and cobalt color number ≤1010 GB/t 3143.
P-toluic acid, mg/kg ≤150 200 sh/t1612.7 (arbitration method),
SH/T 1687
B* Supply and demand agreement SH/T1612.10
particle size distribution
Above 250 microns,% (volume fraction)
Less than 45 microns,% (volume fraction)
D50, micron supply and demand agreement SH/T 16 12.8 or above 250 microns,% (mass fraction) and below 45 microns,% (volume fraction).
Average particle size, μm Both parties agree to Appendix A.
A. Evenly distribute appropriate samples on white utensils or filter paper for visual inspection.
B, firstly, prepare the sample into 5g/ 100mL dimethylformamide (DMF) solution and filter it. Take the filtrate and determine it according to GB/T3 143. (1) The items specified in Table 2. 1 of this standard are all type test items, except for the chromaticity of 5g/ 100mL DMF, all other items are ex-factory inspection items. During normal production, at least once a month.
Type inspection.
(2)PTA products are grouped by batches with the same quality and uniformity, and can be grouped by production cycle, production shift or product storage warehouse.
(3)PTA products shall be sampled according to GB/T 6678 and GB/T 6679. The sample size is 1 kg-2 kg, and the sample is divided into two parts, one for inspection and the other for retention.
(4) Industrial purified terephthalic acid shall be inspected by the quality inspection department of the manufacturer and qualified according to GB/T 1250. The manufacturer shall ensure that the quality of all ex-factory products meets the requirements of this standard.
Beg. Each batch of ex-factory products shall be accompanied by a quality certificate, which includes: manufacturer's name, product name, grade, batch number, net content, production date and code number of this standard, etc.
(5) If the test results do not meet the requirements of this standard, double the representative samples for reinspection. As long as one index of the reinspection results does not meet the requirements of this standard, this batch of products cannot be accepted according to this standard.
(6) The product receiving unit has the right to accept the quality of the PTA products received according to this standard, and the acceptance period shall be agreed by both parties. When the supplier and the supplier have any objection to the product quality, they can settle it through negotiation, or * * * submit it to an arbitration institution for arbitration inspection according to this standard. (1) The bagged products are packed with plastic film, and the net weight of each bag is 1000g. The name, address, trademark, product name, grade, batch number, net content and code number of this standard shall be printed on the packaging bag.
(2)PTA products can also be shipped in stainless steel tank cars. Check whether the tank car is clean and dry before loading. After loading, the entrance should be sealed and sealed with lead.
(3)PTA products should be fireproof, moistureproof and antistatic during transportation. Bagged products should be handled with care to prevent packaging damage; When loading and unloading tank cars, attention should be paid to controlling the loading and unloading speed to prevent static electricity.
(4)PTA products should be stored in a cool, ventilated and dry warehouse, away from fire and heat sources, and stored separately from oxidants, acids and alkalis, and should be protected from sun and rain, and should not be piled up in the open air. (1)PTA is a flammable substance, which is in danger of burning in case of high heat, open flame or contact with oxidant. PTA dust is explosive. Therefore, the production and loading and unloading process of products should pay attention to closed operation and labor.
The workplace should take necessary ventilation and protective measures to prevent product leakage and dust accumulation.
(2)PTA is a low toxic substance, which can stimulate skin and mucous membrane. For allergic people, contact with this product may lead to rash and bronchitis. The maximum allowable concentration in the air is 0. 1mg/m3.