GB/T 34682-2017 in English

《GB/T 34682-2017含有活性稀释剂的涂料中挥发性有机化合物（VOC）含量的测定》由TC5（全国涂料和颜料标准化技术委员会）归口，主管部门为中国石油和化学工业联合会。

ChinaStandards.net is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.

This standard is developed in accordance with the rules given in GB/T 1.1-2009.

This standard was proposed by China Petroleum and Chemical Industry Association.

This standard is under the jurisdiction of SAC/TC 5 National Technical Committee on Paints & Pigments of Standardization Administration of China.


Determination of volatile organic compound (VOC) content in reactive diluent containing coatings

1 Scope

This standard specifies the terms and definitions, principles, instruments and apparatus, samples, test procedures and test data processing for the determination of volatile organic compound (VOC) content in reactive diluent containing coatings.

This standard is applicable to the determination of volatile organic compound (VOC) in reactive diluent containing coatings, but not to the determination of volatile organic compound (VOC) content in radiation curable coatings.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 3186 Paints, varnishes and raw materials for paints and varnishes - Sampling
GB/T 5206-2015 Paints and varnishes - Terms and definitions
GB/T 6750 Paints and varnishes - determination of density - Pyknometer method
GB/T 6753.4-1998 Paints and varnishes - Determination of flow time by use of flow cups
GB/T 9278 Temperatures and humidities for conditioning and testing of paint specimens.
GB 18582-2008 Indoor decorating and refurbishing materials - Limit of harmful substances of interior architectural coatings
GB/T 20777 Paints and varnishes - Examination and preparation of samples for testing
GB/T 21862.2 Paints and varnishes - Determination of density - Part 2: Immersed body (plummet) method
GB/T 21862.3 Paints and varnishes - Determination of density - Part 3: Oscillation method
GB/T 21862.4 Paints and varnishes - Determination of density - Part 4: Pressure cup method

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

3.1
volatile organic compound content; VOC content; VOCC
mass of volatile organic compounds contained in coatings measured under specified conditions

[GB/T 5206-2015, Definition 2.271]

3.2
reactive diluents
also called reactive solvents, which can not only dissolve or disperse film-forming substances, but also participate in the film-forming reaction in the film-forming process of coatings to form non-volatile components to remain in the coating film

Note: For example, glycidyl ethers (for epoxy resin coatings), styrene (for unsaturated resin coatings), diethylene glycol-initiated polycaprolactone (for high solid coatings), polyethylene glycol (for high solid coatings), etc.

4 Principle

Prepare the specimen according to the stated mixing ratio and dilution ratio of the product. After mixing evenly, determine the non-volatile content in the specimen using the difference method under the specified conditions. If the sample contains moisture, its moisture content shall be determined with Karl Fischer method or gas chromatographic method. If necessary, the density of the specimen shall be determined by an appropriate method based on the type of sample. Finally calculate the VOC content in the specimen.

5 Instruments and apparatus

5.1 Metal flat bottom dish

It shall have a diameter of (75±5) mm and an edge height of 5 mm, or it is acceptable provided that the specimen does not overflow. Dishes in different diameters may also be used. In this case, the mass of the specimen used for the test, m, is calculated using Formula (1), in g:

(1)

where,

mstandard——the mass of standard specimen tested, g;

d——the bottom diameter of the dish, mm;

75——the standard diameter of the dish, mm.

Note: For viscous coatings, aluminum foil with a thickness of about 0.1 mm may be used. Cut the aluminum foil into a rectangle with a size of about (100±10) mm x (300±10) mm that may be folded in half, and fully spread the viscous liquid by gently squeezing the folded parts.

5.2 Syringe

Disposable syringe, 10 mL.

5.3 Oven

Warning - In order to prevent explosion or fire, samples containing volatile substances shall be handled carefully in accordance with the relevant provisions of China.

In order to ensure the safety of the test, a forced convection oven shall be selected, which can be kept within ±2℃ of the specified or agreed temperature, and equipped with a partition that can be horizontally placed. A natural convection oven equipped with a perforated metal partition at 1/3 height of the working chamber may also be used.

5.4 Desiccator

Containing suitable desiccant, such as dry silica gel soaked by cobalt chloride.

5.5 Balance

With a precision of 1 mg.

6 Samples

Take samples either in accordance with the requirements of GB/T 3186, or the agreed method, and the sampling quantity shall be so determined to meet the need of inspection.

Examine and prepare the specimens in accordance with the requirements in GB/T 20777.

Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Instruments and apparatus
6 Sample
7 Test procedures
8 Test data processing