GB/T 23985-2009 PDF in English
GB/T 23985-2009 (GB/T23985-2009, GBT 23985-2009, GBT23985-2009)
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Paints and varnishes -- Determination of volatile organic compound (VOC) content -- Difference method
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GB/T 23985-2009: PDF in English (GBT 23985-2009) GB/T 23985-2009
Paints and varnishes.Determination of volatile organic compound (VOC) content.Difference method
ICS 87.040
G50
National Standards of People's Republic of China
GB/T 23985-2009/ISO 11890-1.2007
Paints and varnishes Volatile Organic Compounds (犞OC)
Method for determining the difference
(ISO 11890-1.2007, Paintsandvarnishes-
Determinationof volatileorganiccompound(VOC)content-
Part 1. Difference method, IDT)
Released.2009-06-02
2010-02-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
China National Standardization Administration issued
Foreword
This standard is equivalent to the international standard ISO 11890-1.2007 "color paint and varnish --- volatile organic compound (VOC) content measurement
This standard is equivalent to translation ISO 11890-1.2007.
For ease of use, the editorial changes to this standard are as follows.
--- Replace "this International Standard" with "this standard";
--- Remove the preface to international standards;
--- Other international standards cited in ISO 11890-1.2007 are equivalently adopted as Chinese standards, and replaced by Chinese standards.
The international standards that are applied are not equivalent to the direct reference to international standards for our standards;
---Delete the "first part" in the international standard name;
--- Since the current domestic determination of the moisture content of the coating is mostly by gas chromatography, the content of Note 3 is added in 7.5.
Appendix A of this standard is a normative appendix.
This standard was proposed by the China Petroleum and Chemical Industry Association.
This standard is under the jurisdiction of the National Coatings and Pigments Standardization Technical Committee.
This standard was drafted. CNOOC Changzhou Coating Chemical Research Institute, Kunshan Shiming Technology Development Co., Ltd.
The main drafters of this standard. Ji Junhong, Peng Jufang, Du Changsen.
GB/T 23985-2009/ISO 11890-1.2007
Paints and varnishes Volatile Organic Compounds (犞OC)
Method for determining the difference
1 range
This standard is one of a series of standards for sampling and testing of paints, varnishes and related products.
This standard specifies methods for the determination of volatile organic compounds (VOC) in paints, varnishes and their raw materials.
Samples with a VOC content greater than 15% (mass fraction). When the expected VOC content is greater than 0.1% (mass fraction) and less than 15% (mass cents)
When using the number, GB/T 23986 should be used.
The method assumes that the volatiles are water or organic matter. If other volatile inorganic compounds are present, other suitable methods are required.
Quantitative determination and deduction is considered in the calculation.
2 Normative references
The terms in the following documents become the terms of this standard by reference to this standard. All dated references, followed by all
Modifications (not including errata content) or revisions do not apply to this standard, however, parties to agreements based on this standard are encouraged to study
Is it possible to use the latest version of these files? For undated references, the latest edition applies to this standard.
GB/T 1725 Determination of non-volatile content of paints, varnishes and plastics (GB/T 1725-2007, ISO 3251.2003, IDT)
GB/T 3186 Paint, varnish and paint and varnish raw materials sampling (GB/T 3186-2006, ISO 15528..2000, IDT)
GB/T 6283 Determination of moisture content in chemical products - Karl Fischer method (general method) [GB/T 6283-1986,
Eqv ISO 760.1978,Deletionofwater-KarlFishermethod(Generalmethod)]
GB/T 6750 Determination of density of lacquers and varnishes - s. s. s. (GB/T 6750-2007, ISO 2811-1..1997, Paints
andvarnishes-Determinationofdensity-Part 1.Pyknometermethod, IDT)
GB/T 9278 Coating sample condition adjustment and test temperature and humidity (GB/T 9278-2008, ISO 3270.1984, Paintsand
Varnishesandtheirrawmaterials-Temperaturesandhumiditiesforconditioningandtesting,IDT)
Inspection and preparation of GB/T 20777 paint and varnish samples (GB/T 20777-2006, ISO 1513.1992, IDT)
GB/T 21862.2 Determination of density of paints and varnishes - Part 2. Falling ball method (GB/T 21862.2-2008, ISO 2811-
2.1997, IDT)
GB/T 21862.3 Determination of density of paints and varnishes - Part 3. Vibration method (GB/T 21862.3-2008, ISO 2811-
3.1997, IDT)
GB/T 21862.4 Determination of density of paints and varnishes - Part 4. Pressing cup method (GB/T 21862.4-2008, ISO 2811-
4.1997, IDT)
GB/T 23986 Determination of volatile organic compounds (VOC) content of varnishes and varnishes.
2009, ISO 11890-2.2006, Paintsandvarnishes-Determinationof volatileorganiccompound (VOC)
content-Part 2. Gas-chromatographicmethod, IDT)
3 Terms and definitions
The following terms and definitions apply to this standard.
3.1
Any organic liquid or solid that can naturally evaporate at the normal temperature and pressure of the environment.
GB/T 23985-2009/ISO 11890-1.2007
Note 1. For the term VOC used in the field of coatings, see Volatile Organic Compound Content (VOC Content).
Note 2. The US government regulations stipulate that the term VOC is limited to those compounds that have photochemical activity in the atmosphere (see ASTM D3960), and any
Other compounds are defined as exempt compounds.
[see ISO 4618.2006]
Note 3. European regulations such as the European Directive.2004/42/EC, the term VOC refers to a boiling point of up to 250 ° C at a standard pressure of 101.3 kPa.
Volatile organic compounds.
3.2
The measured amount of volatile organic compounds present in the coating under specified conditions.
Note 1. The nature and amount of compounds to be considered will depend on the field of coating application. For each application area, the method of measurement or calculation and
The limit value is specified by regulations or by both parties.
[see ISO 4618.2006]
Note 2. If the term VOC refers to a compound defined by the highest boiling point (see Note 3 in 3.1), a compound with a boiling point below the limit value is considered as a VOC.
A portion of the content, and a compound having a boiling point higher than the limit value is regarded as a non-volatile organic compound.
3.3
An organic compound that does not participate in photochemical reactions in the atmosphere.
Note. See Note 2 and Note 3 in 3.1.
3.4
According to the manufacturer's instructions, mix the product in the correct proportions. If dilution is required, it should be diluted with a suitable diluent to make the sample
The status can be tested using an approved method.
4 Principle
After preparing the sample, first determine the content of non-volatiles according to GB/T 1725, and then use Karl Fischer reagent according to GB/T 6283.
The water content was determined by titration. If necessary, the content of the exempted compound can be determined by the method given in GB/T 23986. Then count
Calculate the amount of VOC in the sample.
5 Information to be supplemented
For any particular application, the test methods specified in this standard need to be supplemented with additional information. Within the supplementary information
It is listed in Appendix A.
6 sampling
A representative sample from the test product (or each of the multiple coating systems) is taken according to the provisions of GB/T 3186.
According to the provisions of GB/T 20777, each test sample is inspected and prepared, and the final test sample in the "tested" state is prepared.
7 test steps
7.1 Number of measurements and general test conditions
Unless otherwise agreed, all tests are required at temperatures (23 ± 2) ° C and relative humidity (50 ± 5)% (see GB/T 9278).
Parallel determinations were performed in duplicate.
7.2 Determination of parameters
Determine the parameters required for the calculation as specified in 7.3 to 7.6 (see 8.2 to 8.5). Some parameters can be based on the compounds present in the sample
The object is measured by the difference method.
GB/T 23985-2009/ISO 11890-1.2007
7.3 Density
If density values are required for calculation (see 8.3 to 8.5), use GB/T 6750, GB/T 21862.2, depending on the type of sample.
The method of GB/T 21862.3 and GB/T 21862.4 gives the best precision to determine the density of the sample. Density is measured at
It was carried out at 23 °C.
7.4 Non-volatile content
For single-component products, according to the provisions of GB/T 1725, weigh the appropriate amount of samples (see Table 1 in GB/T 1725-2007) placed in the pan, test
The test procedure is carried out in accordance with the provisions of GB/T 1725.
For multi-component systems, thoroughly mix the components according to the manufacturer's instructions, and immediately weigh the appropriate amount according to the provisions of GB/T 1725
Samples (see Table 1 in GB/T 1725-2007) were placed in the pan. Allow test samples in the pan at temperature (23 ± 2) ° C and ambient atmospheric pressure
Place for 1 h, then place the tray in the oven. The test procedure is carried out in accordance with GB/T 1725.
If the test sample will undergo any abnormal decomposition or degradation during the heating process, it may be different from GB/T 1725 after the relevant parties have agreed.
The heating time and/or temperature specified in .
7.5 Moisture content
The moisture content was determined by the method given in GB/T 6283 and expressed in mass fraction. To choose not to be included in the sample
Interfering with Karl Fischer reagent. If the compound is unknown, qualitative identification can be performed using the method given in GB/T 23986.
Note 1. Typical compounds that may cause interference are ketones and aldehydes. Reagent manufacturers generally have instructions to guide people to choose the right reagents.
Note 2. If the test product is obvious or known to be free of water, the moisture content can be set to zero without measuring the moisture content.
Note 3. Gas content can also be determined by measuring the moisture content.
7.6 Exempted compounds (applicable only when required by national regulations)
7.6.1 If the organic compound contained in the sample is unknown, qualitative determination can be carried out by the method given in GB/T 23986.
7.6.2 Determine the amount of exempt compounds contained in the sample using the method given in GB/T 23986.
7.6.3 Determine the density of exempted compounds using the method given in 7.3, or refer to published literature data.
8 calculation
8.1 General
The VOC content is calculated according to the method specified in the specification standard referenced by the test product. If no specific method is specified, press Method 1
Calculate the VOC content.
Since Method 1 does not involve the determination of density (which introduces other errors), the precision is better, which is a preferred calculation method.
8.2 Method 1. The VOC content of the “tested” sample, expressed as mass fraction (%), calculated according to equation (1).
(VOC)=100-(NV)-w (1)
In the formula.
(VOC)---the VOC content of the "tested" sample, expressed as mass fraction (%);
(NV)---non-volatile content, expressed in mass fraction (%) (see 7.4);
w---Moisture content, expressed in mass fraction (%) (see 7.5).
8.3 Method 2. The VOC content of the “tested” sample, in grams per liter (g/L), calculated according to equation (2).
ρ(VOC)= (100-(NV)-w)×ρs×10(2)
In the formula.
ρ(VOC)---the VOC content of the sample to be tested, in grams per liter (g/L);
(NV)---non-volatile content, expressed in mass fraction (%) (see 7.4);
w---water content, expressed in mass fraction (%) (see 7.5);
Ρs---the density of the test sample at 23 ° C in grams per milliliter (g/mL) (see 7.3);
10---The mass fraction (%) is converted into a conversion factor per gram (g/L).
8.4 Method 3. The VOC content of the “tested” sample after deducting water, in grams per liter (g/L), calculated according to equation (3).
GB/T 23985-2009/ISO 11890-1.2007
ρ(VOC)lw =
100-(NV)-w
100-ρs×
燅w
×ρs×1000 (3)
In the formula.
ρ(VOC)lw--- The VOC content of the sample to be tested after deducting water, in grams per liter (g/L);
(NV)---non-volatile content, expressed in mass fraction (%) (see 7.4);
w---water content, expressed in mass fraction (%) (see 7.5);
Ρs---the density of the test sample at 23 ° C in grams per milliliter (g/mL) (see 7.3);
Ρw---the density of water at 23 ° C, in grams per milliliter (g/mL) (at 23 ° C, ρw = 0.9997537 g/mL);
1000---gram per milliliter (g/mL) converted to grams per liter (g/L) conversion factor.
8.5 Method 4. The VOC content of the “tested” sample after deducting water and exempt compounds (applicable only when required by national regulations), in grams
Per liter (g/L), calculated according to equation (4).
ρ(VOC)lwe=
100-(NV)-w-∑
100-ρs×
Ρw
-ρs×∑
Ρec
×ρs×1000(4)
In the formula.
ρ(VOC)lwe---the VOC content of the sample to be tested after deducting water and exempt compounds, in grams per liter (g/L);
(NV)---non-volatile content, expressed in mass fraction (%) (see 7.4);
w---water content, expressed in mass fraction (%) (see 7.5);
Ρs---the density of the test sample at 23 ° C in grams per milliliter (g/mL) (see 7.3);
Ρw---the density of water at 23 ° C, in grams per milliliter (g/mL) (at 23 ° C, ρw = 0.9997537 g/mL);
1000---gram per milliliter (g/mL) converted to grams per liter (g/L) conversion factor.
9 results indicate
If the difference between the two determination results (parallel measurement) is greater than the maximum value specified in 10.2, it is necessary to re-measure.
Calculate the average of two valid results (parallel measurements) and report the results to exactly 1%.
10 precision
10.1 General
Interlaboratory tests were carried out in accordance with ISO 5725-1 and ISO 5725-2 to determine the precision of the test method. From 5 to 7 laboratories
Tested on 3 different materials. Since some test results are outside the scope specified in this test method (see footnote "a" in Table 1),
When calculating the precision, these results are not considered, their VOC content is less than 15% (mass fraction), tested by GB/T 23986 method,
Good precision.
Table 1 Test results between laboratories
Parameter cathodic electrophoretic paint a water-based paint a two-component varnish
Number of laboratories 7 5 6
Repeat the number of measurements 5 5 5
Average value, based on mass fraction (%) 11.46 11.11 39.8
Reproducibility standard deviation 0.93 2.25 0.76
GB/T 23985-2009/ISO 11890-1.2007
Table 1 (continued)
Parameter cathodic electrophoretic paint a water-based paint a two-component varnish
Reproducibility coefficient of variation 8.1 20.3 1.9
Repeatability standard deviation 0.54 0.29 0.23
Repeatability coefficient of variation 4.7 2.6 0.6
a Since the average VOC content is less than 15% (mass fraction), it is not considered when calculating the precision.
The absolute difference between the two single test results obtained (each result is the average of the parallel measurements) is below this value, the result is worth
trust.
10.3 Reproducibility limit R
The reproducibility limit R refers to two test knots obtained from the same material by different operators using standardized test methods in different laboratories.
If the absolute difference between the results (each result is the average of the parallel measurements) is below this value, the results are trustworthy.
The reproducibility of this test method is represented by a coefficient of variation CV (R) of reproducibility, which is 2%.
11 test report
The test report should include at least the following information.
a) indicate the standard number (GB/T 23985);
b) fully identify all the details necessary for the product under test (manufacturer, trademark, lot number, etc.);
c) the content of the supplementary information referred to in Appendix A;
d) indicate the international or national standards, product specifications or other documents referenced in the supplementary information in item c) above;
e) test results, as shown in Chapter 8, and the calculation method used (8.2, 8.3, 8.4 or 8.5);
f) any difference from the specified test method;
g) Test date.
GB/T 23985-2009/ISO 11890-1.2007
Appendix A
(normative appendix)
Information that needs to be supplemented
For the normal use of this method, the terms of the supplementary information listed in this appendix should be provided as appropriate.
The required information is preferably agreed upon by the parties concerned and may be taken in whole or in part from international and national standards related to the product under test.
Or other documents.
a) the organic compound to be determined (if known);
b) the analytical methods used to identify these compounds;
c) which organic compounds in a) are exempt compounds (see 7.6);
d) The calculation method used (see Chapter 8).
GB/T 23985-2009/ISO 11890-1.2007
references
[1] ISO 4618.2006 Paints and varnishes --- Terms and definitions
[2] ISO 5725-1 Method of determination and accuracy of its results (accuracy and precision)---Part 1. General principles and definitions
[3] ISO 5725-2 Methods of measurement and their accuracy (accuracy and precision)---Part 2. Standard methods of measurement
Basic method of repeatability and reproducibility
[4] ASTMD3960 Recommended method for determining volatile organic compound (VOC) content in paints and related coatings
GB/T 23985-2009/ISO 11890-1.2007
...... Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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