Some standard content:
Chemical Industry Standard of the People's Republic of China
Binder for Rubber A
1 Subject Content and Applicable Scope
HG/T2191-91
This standard specifies the technical requirements, test methods, inspection rules and product marking, packaging, transportation and storage requirements of binder A.
This standard applies to hexamethoxymethylmelamine type methyl donor binder, which is prepared by hydroxylation and etherification of melamine. This binder is combined with resorcinol donor binder for bonding rubber to skeleton materials, where skeleton materials include brass-plated or galvanized steel cords, steel ropes and gold-skinned plates, as well as cords or fabrics such as nylon, polyester, vinylon, viscose fiber, glass fiber or cotton.
2 Reference standards
GB601 Preparation of standard solutions for titration analysis (containment and dish analysis) of chemical reagents GB603 Preparation of preparations and products used in chemical reagent test methods GB4472: Determination of density and relative density of chemical products 3. Technical requirements
3.1 Product name and structure
Chemical name: Hexamethoxymethylmelamine
Molecular formula: C1H0N0%
Relative molecular mass: 390.291
3.2 Physical and chemical properties
Crystal soluble in water, alcohol, acetic acid, ether and saturated hydrocarbon solvents, 3.3 Control items and indicators
Adhesive A should meet the following control items and indicators requirements, Item
Chain-free formaldehyde content, %
Bound formaldehyde content, %
Density, g/cm
4 Test method
4.1 Appearance
Test sample should be colorless transparent liquid or waxy body, approved by the Ministry of Chemical Industry of the People's Republic of China from 1991 to 12-23
Colorless transparent liquid or waxy body
1. 205-1, 220
1992-05-01Implementation
w.bzsoso. com4.2 Determination of free formaldehyde and bound formaldehyde content4.2.1 Principle
HG/T 2191 -91
Iodine can be converted to oxidized sodium iodine in alkaline solution: I+2NaOH-NaOI+NaI+H,C
The free formaldehyde in the sample is oxidized by sodium hypoiodite to form stable sodium formate HCHO+NaOI+NaOHHCOONa+NaI+H,OUnder acidic conditions, the iodine released from the remaining sodium hypoiodite can be titrated with sodium thiosulfate standard solution to determine the free formaldehyde
2Na,S,O,+I-Na,S,O,+2Nal
For example, the methoxyl groups on the sample molecules are first completely hydrolyzed into methanol under acidic conditions, and then further oxidized into stable sodium formate in an alkaline solution of iodine. The iodine released from the remaining sodium hypoiodite in the system is titrated with sodium thiosulfate standard solution to determine the content of bound formaldehyde in the sample.
4.2.2 Reagents and Materials
4.2.2. 1 Sodium hydroxide solution (GB 629): (NaOH) = 2 mol/ 1 Weigh 80g of sodium hydroxide, dissolve it in 600mL of water, cool and dilute to 1000mL4. 2.2.2 Iodine standard solution (GB 675)cPrepare and calibrate according to GB 601
4.2.2.3 Sulfuric acid solution (GB625):c.
-I,) 0. 1 mol / L.
-HSO,) = 2mol/I
Measure 60L of sulfuric acid, slowly add it into water, cool, shake well, and dilute to 1000㎡L, 4.2.2.4 Sodium thiosulfate standard titration solution (GB637):c(Na,SO）=0.1ml/L:Prepare and calibrate according to GB 603 Preparation and calibration,
4,2.2.5 5% starch drop solution: Prepare according to GB603, 4.2.3 Instruments and equipment
4.2.3.1 Analytical balance: Sensitivity 0.0001g4.2.3.2 Pipette: 25mL;
4.2. 3.3 Volumetric flask: 500mL;bzxz.net
4. 2.3. 4 Acid burette: 50mL;
4.2.3.5 Iodine volumetric flask: 250mL;
4. 2.3. 6 Water bath.
4.2.4 Test solution
Weigh 0.5g of the sample, accurate to 0.0002, dissolve it in a volumetric flask with hot water at a temperature of 40°C, cool it, dilute it to the scale with water, shake it and set it aside.
4.2.5 Analysis steps for free formaldehyde content
Use a pipette to draw 25 mL of the test solution (4.2.4) into an iodine volumetric flask, add 15 mL of sodium hydroxide solution (4.2.2.1), then use a pipette to add 25 mL of the iodine standard solution (4.2.2.2), cover the bottle stopper, place it in a dark place and let it stand for 15 min, then add 25 mL of sulfuric acid solution (4.2.2.3), and titrate with sodium thiosulfate standard titration solution (4.2.2.4). When the ink turns light yellow, add a few drops of starch solution (4.2.2.5), continue to titrate until it is colorless, and record the volume of sodium thiosulfate standard titration solution consumed. 14.2. Analysis steps for formaldehyde content
wWu HG/T 2191 —91
Use a pipette to draw 25mL of the sample (4.2.4) into the iodine volumetric flask, add 10mL of sulfuric acid solution (4.2.2.3) preheated to 30-35, keep warm in a water bath at 60℃ for 2min, add 25mL of sodium hydroxide solution (4.2.2.1), then use a pipette to add 25mL of iodine standard solution (4.2.2.2), cover the bottle stopper, and let it stand in a dark place for 15min. Then, add 25mL of sulfuric acid solution (4.2.2.3), and titrate with sodium thiosulfate standard titration solution (4.2.2.4). When it turns light yellow, add a few drops of starch solution (4.2.2.5) and continue to titrate until it is colorless. Record the volume Vz of sodium thiosulfate standard titration solution consumed. According to the determination conditions and analysis steps of the formaldehyde content, make a blank test with water. Record the volume V of sodium thiomercaptoate standard titration solution consumed.
4.2. Expression of analysis results
4.2.7.1 The amount of free formaldehyde (%) is calculated according to formula (1): (V. - V) c × 500 × 0. 015 0225m
The amount of bound formaldehyde (%) is calculated according to formula (2): (V - V,) *c × 500 × 0. 015 0225m
Where: We
X 100 :
× 100 -
(V. - v,) +e× 30. 04
(V, - V,) : ex 30. 04
The volume of sodium thiosulfate standard titration solution consumed in the blank test, mL; V
The volume of sodium thiosulfate standard titration solution consumed by the unhydrolyzed sample, mL; V-The volume of sodium thiosulfate standard titration solution consumed by the hydrolyzed sample, mL; The concentration of sodium thiosulfate standard titration solution, mol/L; The mass of the sample, 2:
With 1.00mL sodium thiosulfate standard titration solution [c(NazS,0,)=1mal / L) equivalent; -gram expressed as the mass of formaldehyde,
4.2.7.2 Take the average of the parallel test results as the content of free formaldehyde and bound formaldehyde, 4.2.8 Permissible difference
The parallel test difference of free formaldehyde should not be greater than 5%, and the parallel test difference of bound formaldehyde should not be greater than 1%, 4.3 Density determination Densitometer method
4.3.1 Principle
The depth of the densitometer immersed in the measured liquid when it reaches equilibrium is the density of the liquid, 4.3.2 Instrument
4.3.2. 1 Densitometer: the graduation value is 0.001 g/cm, which meets the requirements of Figure 6 of GB4472, 4. 3.2.2 Constant temperature water bath;
4.3.2, 3 Glass monitoring tube: 250~500 mL; 4. 3.2. 4 Thermometer: 0~50t, graduation value is 0.1℃, 4:3.3 Sample
When the sample is a flowing liquid, it can be measured directly. If the sample is a waxy body, the sample can be heated in a water bath at 35~40℃, and melted into liquid as a test sample. 4.3.4 Analysis steps
Follow the operating steps specified in Article 2.3.3.3 of GB4472, the test temperature is 20±0.1C, 4.3.5 Expression of analysis results
Calculate according to the method specified in Article 2.3.3.4 of GB 4472, 4.3.6 Precision
-HG/T 2191—91
The absolute value of the measurement result is accurate to 0.001g/cm25Testing rules
5.1 Adhesive A shall be inspected by the quality inspection department of the manufacturer to ensure that each batch of products shipped out of the factory meets the technical requirements of this standard.5.2 The user has the right to review the quality of the purchased products according to the technical requirements and test methods specified in this standard.5.3 Batching and sampling
5. 3. 1 Batching
The manufacturer takes one batch of products as a batch: the user takes the total amount purchased at one time as a batch5.3.2 Sampling
Sampling 20% of the packaging quantity of each batch of products. The sampling packaging number shall not be less than 3 pieces. If the packaging quantity of each batch of products is less than 3 pieces, samples shall be taken piece by piece. The amount of each sample shall not be less than 100g5. 3.3 Sampling method
5.3.3.1 Adhesive A products can be melted from waxy bodies to flowing liquids at about 35. When the products packaged in metal barrels are liquids, they can be sampled with stainless steel sampling tubes or other suitable samplers. If the product in the package is waxy, place the packaged product in a hot melt chamber at 35-40℃ to completely melt the product before sampling. When sampling, obtain approximately equal number of samples from different parts of the upper, middle and lower parts of the packaging barrel.
5.3.3.2 Collect the extracted samples in a large container and stir them thoroughly. After mixing, mix them into an average sample. Take 100g of the average sample and put them in two clean and dry ground-mouth bottles respectively. Attach labels and indicate the sample name, batch number, production date and sampling date. Send one bottle to the quality inspection department for quality inspection and the other bottle for re-inspection or arbitration. The sample retention period is half a year. 5.4 Judgment rules
5.4.1 If one of the indicators of product quality inspection results does not meet the requirements of this standard, two samples of the same quantity should be taken from twice the amount of packaging according to the specified sampling method for re-testing. If the re-test results still do not meet the requirements of this standard, the entire batch of products shall be deemed unqualified. 54.2 When the supply and demand parties have objections to the product quality, the quality supervision agency specified by the state may conduct arbitration. 6 Marking, packaging, transportation, storage
61 Marking
The surface of the adhesive A packaging is printed with obvious and firm markings, indicating the manufacturer's name, product name, trademark, production date, production batch number, main product parameters and effective period of use, etc. 6.2 Packaging
Adhesive A is packaged in a tinplate box, with a net weight of 20kg per barrel. 6.3 Transportation
This product must not be bumped or thrown during transportation and loading and unloading. 6.4 Storage
This product should be stored in a dry and clean warehouse, and must not be piled in the open air or exposed to moisture. The effective storage period is 1 year from the date of production. Additional instructions:
This standard was proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China, and this standard is under the jurisdiction of the Shanghai Rubber Products Research Institute. This standard was drafted by the Beijing Rubber Industry Research and Design Institute of the Ministry of Chemical Industry and Changzhou Shuguang Chemical Factory. The main drafters of this standard are Pu Qijun, Chen Naijue and Ding Juan
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