This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of water-emulsified polyurethane finishing agents for leather making. This standard applies to anionic and cationic aqueous emulsions made by self-emulsification with isocyanate as the base material, mainly used as finishing agents for pig, cattle, sheep and other leathers in the leather industry. QB/T 2415-1998 Water-emulsified polyurethane finishing agents for leather making QB/T2415-1998 Standard download decompression password: www.bzxz.net

QB/T2415
—1998
The technical indicators of this standard are formulated with reference to relevant foreign product indicators and user requirements and in combination with existing processes. This standard is proposed by the Industry Management Department of the State Bureau of Light Industry. This standard is under the jurisdiction of the National Fur Leather Standardization Center. The drafting units of this standard are: Anhui University Kezhao Fine Chemical Factory, Sichuan Union University, and Zhejiang Sanmen Polyurethane Products Factory. The main drafters of this standard are: Zeng Jun, Wang Wusheng, Ruan Deli, Chen Jiahua, and Yang Linqi. 414
Light Industry Industry Standard of the People's Republic of China
Water-emulsified polyurethane finishing agent for leather
QB/T 2415—1998
This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation, and storage of water-emulsified polyurethane finishing agents for leather.
This standard applies to anionic and cationic aqueous emulsions made by self-emulsification with isocyanate as the base material, mainly used as finishing agents for pig, cattle, sheep and other leathers in the leather industry.
2 Referenced 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, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T528—1992 Determination of tensile properties of vulcanized rubber and thermoplastic rubber GB/T9865.1—1996 Preparation of samples and test specimens of vulcanized rubber or thermoplastic rubber GB/T15256—1994 Determination of low-temperature brittleness of vulcanized rubber (multiple specimen method) QB/T2412—1998 Technical general rules for leather chemicals 3 Product classification
Part · Physical test
Products are classified according to the hardness of polyurethane film into soft finishing agents, medium-hard finishing agents and hard finishing agents. 4 Technical requirements
Technical requirements should comply with the provisions of Table 1.
Total solids, %
Film hardness, Shore A
Film tensile strength, MPa
Film elongation at break, %
Film cellular temperature, ℃
Test method
Cations
Anions
Soft finishing agent
Medium hard finishing agent
Emulsion without mechanical impurities and coagulants 17.0
The general rules for sampling and testing shall comply with the provisions of Chapters 3 and 4 of QB/T2412-1998. Approved by the State Bureau of Light Industry on 1998-11-25
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Hard finishing agent
Implemented on 1999-06-01
5.1 Appearance
QB/T2415-1998
Observe the emulsion visually for mechanical impurities and agglomerates. 5.2 Determination of total solid content
5.2.1 Instruments and equipment
a) Ground-mouth flat-bottom weighing bottle with cover: 40mm×25mm; b) Electric constant temperature oven: 0℃~200℃, c) Analytical balance: sensitivity 0.0001g,
d) Dryer: with effective desiccant inside.
5.2.2 Steps
Weigh 1g~~2g of the sample (accurate to 0.0001g) into a weighing bottle that has been dried to constant weight, and place it in a (105±2)℃ constant temperature oven for 4h. Take out the weighing bottle, cover the bottle cap, cool it in a desiccator for 30min, and weigh it. After drying for 30min, cool it and weigh it until constant weight (the difference between the two weighings is no more than 0.001g, take the smallest value). 5.2.3 Calculation
W—sample mass, g,
W,—weighing bottle mass, g;
W2---weighing bottle and dry mass.
The results of two parallel tests are no more than 0.3, and the average value is taken. 5.3 Determination of pH
5.3.1 Instruments
a) pH meter with glass electrode: measuring range is 0-14, minimum scale value is 0.02 unit, b) beaker: 200mL.
5.3.2 Procedure
Pour about 100mL of the sample into a 200mL beaker, wash the electrode carefully with distilled water and dry it with soft absorbent paper, rinse the glass electrode once or twice with the test water emulsion, insert the electrode into the beaker containing the sample, and measure the pH. The electrode should be cleaned carefully immediately after the test. 5. 3. 3 Calculation
The results of two parallel tests, with a difference of no more than 0.2pH units, are averaged. 5.4 Preparation of thin film
5.4.1 Equipment
a) Adjustable water platform; area 200mm×150mmb) Level ruler;
c) Template (polytetrafluoroethylene): 120mm×120mm×5mm, d) Glass,
e) Vacuum drying oven: equipped with vacuum gauge, thermometer graduation value is 1℃, f) Dryer: filled with effective desiccant.
5.4.2 Steps
Use a level ruler to adjust the adjustable water platform to level, and place the cleaned template on the water platform. Pour the sample (75±5)g on the template and distribute it evenly, and dry it at room temperature. When the emulsion film is transparent, put it in a vacuum drying oven with a vacuum degree of 0.0933MPa (700mmHg), raise the temperature to 60℃~62℃, and dry it for 4h. Then raise the temperature to 90℃~92℃ and continue drying for 2h. After the template cools down, gently remove the film and put it in a dryer (a layer of vinyl film can be laid on the porcelain plate in the dryer) for use. The film should be uniform and flat, without defects such as bubbles and cracks. 416
QB/T 2415--1998
Thickness of film: 0.6mm~~1.2mm [When the thickness of the film exceeds 1.2mm, release the emulsion to a total solid content of about (20±1)% and then re-film].
5.4.3 Sample pretreatment
Before the test, the sample should be placed in an environment with a temperature of (20±2)℃ and a relative humidity of 60%~~70% for 4h. The test is required to be carried out under this condition.
5.5 Determination of film hardness
5.5.1 Instrument
Rubber hardness tester: The measurement range requires hardness 0~100, and the minimum scale is 1 unit. Before the measurement, the pointer of the hardness tester should point to zero in a free state, and the pointer should point to 100 degrees when the hardness tester is pressed on the glass plate. 5.5.2 Steps
Cut the sample with a cutter and re-cut it in parallel to make its thickness exceed 6mm. Hold the hardness tester and press it flat on the sample until the bottom of the hardness tester is in full contact with the surface of the sample. Within 1s, read the scale indicated by the pointer of the hardness tester, which is the hardness value of the sample. Three points should be selected at different positions for each measurement, and the point distance should be greater than 6mm. The result is the median value. 5.6 Determination of film tensile strength
5.6.1 Principle
Tensile strength is the maximum tensile stress of the sample during the process of stretching to fracture. 5.6.2 Equipment
a) Dumbbell-shaped cutter: should comply with the provisions of GB/T9865.1, and the size should comply with the provisions of Type 2 in GB/T528-1992; b) Tensile machine: the speed must be uniform and can be adjusted as needed; the reading range must be between 15% and 85% of the full load range,
c) Thickness gauge
Measuring range: 0mm~10mm, graduation value 0.01mm; one measuring surface diameter: (10±0.1)mm, total pressure of the presser foot (100±5)g. 5.6.3 Steps
5.6.3.1 On the finished film, use the dumbbell-shaped cutter to take three samples in turn and number them. Mark a parallel line with a distance of 20mm in the middle of the sample, and each marking line should be equidistant from the center of the sample. 5.6.3.2 Use the thickness gauge to measure the thickness at different positions within the sample marking line. There should be no less than three measuring points, and take the average value. 5.6.3.3 Clamp the sample vertically between the upper and lower clamps of the tensile machine, the tensile speed is (500 ± 50) mm/min, start the switch, and record the load value when it breaks.
5.6.3.4 Calculation
Where: X—--tensile strength of the sample, MPa; F—load value when the sample is pulled apart, N;
S—average cross-sectional area of ​​the sample, mm2.
The median value is taken for the result.
5.7 Determination of elongation at break of film
5.7.1 PrincipleWww.bzxZ.net
Elongation at break is the ratio of the elongation of the sample when it is pulled apart on the tensile machine to the original length, expressed as a percentage. 5.7.2 The elongation at break of the sample
is determined during the process of determining the tensile strength, and no additional sampling is required. 5.7.3 Steps
(2)
During the process of measuring the tensile strength of the film, when the sample is stretched, measure the distance between the two markings at any time. When the sample breaks, the distance between the two markings is 417
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, which is the length of the sample when it breaks.
5.7.4 Calculation
Where: X is the elongation at break of the sample, %;
QB/T2415--1998
Li is the distance between the markings when the sample breaks, mm; L is the distance between the markings of the original sample, mm.
The median value is taken.
5. 8 Determination of the brittle temperature of the film
5.8.1 Principle
The brittle temperature is the lowest temperature at which the sample is impacted under the specified low temperature conditions without being damaged. 5.8.2 Equipment and Materials
(3)
a) Brittleness temperature measuring instrument: It consists of an electrical box, a low temperature box, a gearbox, a stirrer, a sample holder, and an impact head. The instrument should comply with the provisions of Chapter 4 of GB/T15256--1994;
b) Low temperature thermometer: The graduation value is 1°C, and the lowest temperature is -50°C; c) Heat transfer medium: industrial alcohol or silicone (with a kinematic viscosity of 5mm2/s at room temperature), d) Refrigerant: liquid nitrogen or dry ice.
5.8.3 Steps
5.8.3.1 Sample preparation
Specifications: Strip sample with a length of 25mm~40mm, a width of (6±1)mm, and a thickness of (0.8±0.2)mm. Requirements: Smooth surface, free of foreign impurities and defects. 5.8.3.2 Add heat transfer medium to the low temperature tank. Start stirring, slowly add refrigerant, and adjust the medium to the temperature specified in Table 1. 5.8.3.3 Fix the five cut specimens (as a group) on the sample clamp, diffuse into the medium of the low temperature tank, time for 3 minutes, record the temperature, and apply the impact to the specimen.
5.8.3.4 Take out the specimens. If three or more specimens in a group do not break, they are considered qualified. On the contrary, if three or more specimens in a group break, they are considered unqualified. Determine whether the sample is broken according to 7.1.1.4 of GB/T15256--1994. 5.8.3.5 Determination of brittle temperature shall be carried out according to GB/T15256-1994. Note: A new piece should be used for each impact.
6 Inspection rules
6.1 Batch
Products produced at one time with the same raw materials and the same process are considered as a batch. Samples are taken for inspection according to the production batch, and each batch is not less than 500g. 6.2 Factory inspection
6.2.1 Products must be inspected batch by batch before leaving the factory, and can only leave the factory after passing the inspection. 6.2.2 Inspection items: The serial numbers 1, 2, and 3 in Table 1 should be inspected. 6.2.3 Qualification judgment
If all three indicators are qualified, it is deemed qualified. 6.3 Type inspection
6.3.1 Type inspection should be carried out in any of the following situations. a) When there are major changes in product structure, process, and materials; b) When the product is resumed after a long period of suspension; c) When the national quality supervision agency proposes a requirement for type inspection; d) When production is normal, type inspection is carried out once a month. 418
6.3.2 Sampling quantity
QB/T 2415-1998
3 to 5 packaging units are randomly selected from each batch of products, and 150g to 200g is taken from each package. 6.3.3 Qualification judgment
In Table 1, serial numbers 2, 4, 5, 6, and 7 are the main items, and the rest are minor items. If only one minor item index fails in the test result, the product is judged to be qualified. If two (or more) item indexes fail, the sample should be doubled again and the unqualified items should be retested. If the retest results still show that two (or more) item indexes fail, the product is judged to be unqualified.
7 Marking, packaging, transportation, and storage
7.1 Marking
Each package should be painted or affixed with a firm mark, which includes: product name, model (specify soft, medium hard, hard), batch number, production date, shelf life, factory name, factory address, trademark, net weight, standard number, and stamped with the manufacturer's inspection qualified mark or attached with a certificate of compliance. 7.2 Packaging
Products are packaged in clean, pollution-free, well-sealed containers that are easy to transport. 7.3 Transportation
When shipping, the product should be loaded and unloaded with care, avoid severe impact, prevent the packaging from being damaged and causing leakage, and prevent exposure to sunlight, freezing, moisture, and fire. 7.4 Storage
7.4.7 The product should be stored in a ventilated and cool warehouse at a storage temperature of 5℃~~35℃, and should be protected from exposure to sunlight, freezing, moisture, and fire. 7.4.2 The product in the original packaging (original, sealed, original label intact without abnormality) should be stored and transported according to the specified conditions, and the shelf life is one year from the date of production.
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When shipping, the product should be loaded and unloaded with care, avoid severe impact, prevent the packaging from being damaged and causing leakage, and prevent exposure to sunlight, freezing, moisture, and fire. 7.4 Storage
7.4.7 The product should be stored in a ventilated and cool warehouse at a storage temperature of 5℃~~35℃, and should be protected from exposure to sunlight, freezing, moisture, and fire. 7.4.2 The product in the original packaging (original, sealed, original label intact without abnormality) should be stored and transported according to the specified conditions, and the shelf life is one year from the date of production.
HiiKAoNniKAca=3 Transportation
When shipping, the product should be loaded and unloaded with care, avoid severe impact, prevent the packaging from being damaged and causing leakage, and prevent exposure to sunlight, freezing, moisture, and fire. 7.4 Storage
7.4.7 The product should be stored in a ventilated and cool warehouse at a storage temperature of 5℃~~35℃, and should be protected from exposure to sunlight, freezing, moisture, and fire. 7.4.2 The product in the original packaging (original, sealed, original label intact without abnormality) should be stored and transported according to the specified conditions, and the shelf life is one year from the date of production.
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