GB/T 33374-2016 PDF in English
GB/T 33374-2016 (GB/T33374-2016, GBT 33374-2016, GBT33374-2016)
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Ultraviolet curable coatings -- Determination of volatile content
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Standards related to (historical): GB/T 33374-2016
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GB/T 33374-2016: PDF in English (GBT 33374-2016) GB/T 33374-2016
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 87.040
G 50
Ultraviolet curable coatings - Determination of volatile
content
ISSUED ON: DECEMBER 30, 2016
IMPLEMENTED ON: JULY 01, 2017
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 4
4 Instruments and apparatuses ... 5
5 Sampling ... 6
6 Test procedures ... 6
7 Calculation and expression of test results ... 8
8 Repeatability ... 9
Ultraviolet curable coatings - Determination of volatile
content
1 Scope
This Standard specifies the determination methods of volatile content in ultraviolet
curable coatings.
This Standard applies to the determination of volatile content in ultraviolet curable
coatings. Ultraviolet curable inks, adhesives, electron beam-curable coatings, inks, and
adhesives can also refer to this Standard.
This Standard does not apply to water-based ultraviolet 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 to this document. For
undated references, the latest edition (including any amendment) applies to this
document.
GB/T 3186, Paints, varnishes and raw materials for paints and varnishes - Sampling
GB/T 6753.4-1998, Paints and varnishes - Determination of flow time by use of flow
cups
GB/T 20777, Paints and varnishes - Examination and preparation of samples for
testing
3 Terms and definitions
The following terms and definitions are applicable to this document.
3.1 Ultraviolet curing; UV curing
The hardening process of coatings exposed to UV radiation.
3.2 Processing volatiles
Mass loss of the sample during the curing process, under the specified test conditions
(i.e., the conditions that simulate the actual industrial ultraviolet curing process).
3.3 Potential volatiles
Mass loss of the UV-cured sample in the process of drying at (110±2) °C for 60 min.
4 Instruments and apparatuses
4.1 Metal flat-bottom vessel
Diameter (75 ± 5) mm, edge height 5 mm or ensuring that the sample does not overflow.
Alternatively, it can be a vessel of different diameter, while the sample weight shall
vary according to the diameter.
Note: The viscous coatings can also be made of aluminum foil of a thickness about 0.1
mm. Cut it into a rectangle of a size about (100±10) mm × (300±10) mm that
can be folded in half; lightly squeeze the two folded parts to spread the viscous
liquid completely.
4.2 Oven
Warning – In order to prevent explosion or fire, samples containing volatile
substances shall be handled with care, and shall be implemented in accordance
with relevant national regulations.
In order to ensure the safety of the test, a forced convection oven shall be selected,
which can be maintained within the range of ±2 °C of the specified or agreed
temperature, and be equipped with a horizontal shelf. Alternatively, a natural
convection oven, which is equipped with perforated metal baffles at 1/3 the height of
the working chamber, can be used.
4.3 Desiccator
Loaded with a suitable desiccant, such as dry silica gel that has been impregnated with
cobalt chloride.
4.4 Balance
Accuracy 0.1 mg.
4.5 Syringe
Disposable syringe, of capacity 1 mL.
4.6 Ultraviolet curing equipment
Ultraviolet curing equipment shall meet the following conditions:
-- Spectral range: ≥250 nm, main band wavelength 365 nm;
75 – standard diameter of the vessel, in millimeters (mm).
Note 1: When mixing samples, manual stirring can not only ensure that the samples are
evenly mixed, but also avoid the generation of air bubbles.
Note 2: The surface of the syringe – after taking the sample – shall be wiped clean; the
sample shall not be left in the neck of the syringe, which can be solved by
pulling up the plug of the syringe. After injecting the sample, do not wipe the
tip of the syringe; instead, remove the sample on the tip by pulling up the plug
of the syringe; cap and reweigh the syringe. Weigh the sample (accurate to 0.1
mg) by the decrement method.
Note 3: If the sample is incompatible with acetone, tetrahydrofuran or a mixed solution
of acetone and tetrahydrofuran can be used to dissolve and disperse.
Note 4: Spread the to-be-tested sample on the bottom of the vessel (see 4.1); otherwise,
the incomplete curing, due to the excessive thickness of the coating film, will
lead to large test results.
Note 5: Disposable gloves (rubber gloves or polyethylene gloves) shall be worn for all
weighing operations during the test.
6.4 Immediately after weighing, place the sample in an oven (see 4.2), and bake at
(50±2) °C for 30 min.
Note 1: This is a step of simulating the removal of inert solvents in the industrial
production stage. Where the sample contains a large amount of solvent, direct
curing will lead to a great deviation between the test results and the actual
results.
Note 2: Alternatively, if it is known that the volatile content in the sample is less than
3%, the step of 6.4 can be omitted and ultraviolet curing can be carried out
directly.
Note 3: If the sample contains volatile reactive diluents (such as styrene, isobornyl
acrylate) at 50 °C, the step of 6.4 cannot be carried out regardless of the volatile
content.
6.5 Immediately after taking the sample out of the oven, perform the ultraviolet curing
according to the curing requirements specified for the to-be-tested sample. After
ultraviolet curing, place it at room temperature for 15 min; weigh the mass (m2)
(accurate to 0.1 mg) of the cured sample and vessel (see 4.1).
Note: In order to avoid the influence of insufficient ultraviolet curing energy on the
experimental results, the curing energy can be increased by 50% for a
comparative test. If the test results meet the repeatability requirements, the test
results shall be accurate. If the test results do not meet the repeatability
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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