SSPC: The Society for Protective Coatings
Paint SPECIFICATION NO. 39
Two-Component Aliphatic Polyurea Topcoat
- This specification contains performance require-ments for a
two-component, weatherable polyurea topcoat. The coating may be
fast or moderately fast drying (see Note 12.1).
- Coatings meeting the requirements of this specifica-tion are
generally suitable for exposures in Environmental Zones 1A
(interior, normally dry), 1B (exterior, normally dry), 2A
(frequently wet by fresh water, excluding immersion), and 2B
(frequently wet by salt water, excluding immersion). Resistance of
polyurea topcoats in Environmental Zones 3B (chemical exposure,
neutral) and 3C (chemical exposure, alkaline) can vary based upon
formulation. The coating manufacturer should be contacted for
specific chemical resistance data if required.
- The specified coating is intended for application by
single-component airless spray, electrostatic spray, or
plural-component equipment, depending upon its formulation.
- This coating is intended for use as a topcoat over suitably primed
ferrous metal and cementitious substrates.
- The resins used in the coating shall result in a polyurea product
as described in Notes 12.1.1 and 12.1.2 or a hybrid system as
described in Note 12.2. This coating is comprised primarily of
polyamine and polyisocyanate resins that react to form a polyurea.
- COATING TYPE: The two types of polyurea coat-ings are differentiated by drying
time.
- Type 1 (Fast Drying): A Type 1 coating dries to handle in less than 30 minutes (per ASTM
D 1640).
- Type 2 (Moderate Drying): A Type 2 coating dries to handle from 30 minutes to 2 hours (per
ASTM D 1640).
2.3 RESIN TYPES: A coating meeting the requirements of this specification shall be
a hindered aliphatic polyurea, non-hindered aliphatic polyurea, or
hybrid coating (see Notes 12.1 and 12.2).
2.4 WEATHERING LEVELS: This specification contains three levels of accelerated weathering
(Levels 1A, 2A and 3A) and two levels of outdoor weathering
performance (Levels 1N and 2N). Table 1 specifies the amount of
time the coating must perform before noticeable color and gloss
change in order to achieve the required performance level as
defined in paragraphs 2.4.1 through 2.4.5 and Table 1. A certain
level of accelerated weathering does not necessarily correspond to
a particular level of atmospheric weathering. The speci-fier shall
stipulate the requirements for outdoor weathering, accelerated
weathering, or both. These are two independent, complementary tests
for measuring coating performance. If no performance level and/or
specific weathering test is speci-fied, Level 3A for accelerated
weathering (longest accelerated exposure) will be assumed.
- Level 1A: Level 1A coatings have been evaluated for 500 hours in accelerated
weathering testing.
- Level 2A: Level 2A coatings have been evaluated for 1000 hours in
accelerated weathering testing.
- Level 3A: Level 3A coatings have been evaluated for 2000 hours in
accelerated weathering testing.
- Level 1N: Level 1N coatings have been evaluated for 12 months in natural
exterior weathering testing.
- Level 2N: Level 2N coatings have been evaluated for 24 months in natural
exterior weathering testing.
Typical specular gloss levels are shown in Note 12.3.
Polyurea topcoats are available in a wide range of color and gloss.
Procurement documents shall state the desired level of performance,
exposure method, color, and gloss. For example, a specifier may
require Level 2N outdoor exposure, initial gloss greater than 80,
matched to a specific color.
2.5 This specification addresses performance proper-ties of only white
and pastel colored coatings. Because dark pigments are more
sensitive to ultraviolet degradation, testing of individual
coatings in deep tones and safety colors is neces-sary to establish
their color and gloss retentive properties.
SSPC-Paint 39
April 1, 2004
- The latest issue, revision, or amendment of the refer-enced
documents in effect on the date of invitation to bid shall govern
unless otherwise specified. Those documents marked with an asterisk
(*) are referenced only in the Notes or the Appendix, which are not
requirements of this specification.
- If there is a conflict between the requirements of any of the cited
reference documents and this specification, the requirements of
this specification shall prevail.
Guide 13 | Guide for the Identification and Use |
| of Industrial Coating Materials in |
PA 2 | Computerized Product Databases |
Measurement of Dry Film Thickness |
| with Magnetic Gages |
3.4 ASTM INTERNATIONAL STANDARDS:1
D 523 Standard Test Method for Specular Gloss D 562 Standard Test Method for Consistency of Paints Measuring Krebs
Units (KU) Viscosity
Using the Stormer-Type Viscometer
D 1014 Standard Practice for Conducting Exterior Exposure Tests of Paints
on Steel
D 1296 Standard Test Method for Odor of Volatile Solvents and Diluent
D 1475 Standard Test Method for Density of Liquid Coatings, Inks, and
Related Products
D 1535 Standard Practice for Specifying Color by the Munsell System
D 1640 Standard Test Methods for Drying, Curing, or Film Formation of
Organic Coatings at Room Temperature
D 1849 Standard Test Method for Package Stability of Paint
D 2244 Standard Test Method for Calculation of Color Differences from
Instrumentally Measured Color Coordinates
* D 2369 Standard Test Method for Volatile Content of Coatings
* D 2371 Standard Test Method for Pigment Content of Solvent-Reducible
Paints
* D 2621 Standard Test Method for Infrared Identification of Vehicle Solids
from Solvent-Reducible Paints
D 3925 Practice for Sampling Liquid Paints and Related Pigmented Coatings
D 4541 Standard Test Method for Pull-Off Strength of Coatings Using
Portable Adhesion Testers D 4587 Standard Practice for Fluorescent UV-Condensation Exposures of
Paint and
Related Coatings
D 5402 Standard Practice for Assessing the Solvent Resistance of Organic
Coatings Using Solvent Rubs
3.5 AMERICAN NATIONAL STANDARDS
INSTITUTE (ANSI) STANDARD:2
Z129.1 Hazardous Industrial Chemicals
– Precautionary Labeling
3 . 6 FEDERAL SPECIFICATIONS AND
STANDARDS:3
FED-STD-141: Paint, Varnish, Lacquer and Related
Materials: Methods of Inspection, Sampling
and Testing3
- Method 3011 Condition in Container Method 4331 Spraying Properties
- This is a performance-based coating specification, therefore the
manufacturer is given wide latitude in the selection of materials
and manufacturing processes (see Note 12.4).
- RESIN REQUIREMENT: The reactive components used in the coating shall be comprised
primarily of polyamine and polyisocyanate resins that react to form
a polyurea (see Notes 12.1 and 12.2).
- Standard Testing Conditions
- TEST PANELS [each test specifies the number of replicates]: Panel size shall
be 75 x 150 x 5 mm (3 x 6 x 3/16 inches) or greater. All test
panels shall be coated with the primer recommended by the topcoat
manufacturer. Follow the primer manufacturer’s instructions for
surface preparation, application, and cure of the primer.
- APPLICATION: In accordance with the manufac-turer’s written recommendations,
the topcoat shall be spray-applied in a single coat or multiple
coats.
- DRY FILM THICKNESS: The minimum dry film thickness (DFT) of the test panels shall be
the manufacturer’s written recommended minimum thickness. If there
is no recom-mended film thickness, then the minimum DFT shall be
150
- ASTM, 100 Barr Harbor Road, West Conshohocken PA, 19248,
(http://www.astm.org).
- ANSI, 1819 L Street, NW, Washington, DC 20036,
(http://www.ansi.org).
- FED-STD 141 may be obtained from http://assist.daps.dla.mil.
micrometers (6.0 mils). The maximum DFT of the test panels shall be
50 micrometers (2.0 mils) more than the minimum or 135% of the
minimum, whichever is greater. The DFT shall be measured in
accordance with Appendix 5 of SSPC-PA 2.
- CURE: Before any testing, the coating shall be dried and cured in
accordance with the manufacturer’s written recommendations, or
otherwise shall be aged for a minimum of 30 days in an environment
with a relative humidity of 50 ± 10% and an ambient temperature of
25 ± 2°C (77 ± 5°F).4
- BACKS AND EDGES: Coat and seal all edges and the back of each panel with a coating
or tape that will provide the necessary protection to these
surfaces.
- Requirements of Liquid Coating
- APPLICATION PROPERTIES: All guidance provided by the manufacturer regarding mixing of
multi-compo-nent products, thinning requirements, and special
application requirements shall be followed. The coating shall be
easily applied by spray when tested in accordance with FED-STD-141,
Method 4331. The paint shall show no streaking, running, or sagging
during application or while drying.
- PACKAGE STABILITY: Package stability shall be tested in accordance with ASTM D 1849.
Storage conditions shall be 30 days at 52 ± 1°C (125 ± 2°F). A
change in consis-tency of greater than 10 Krebs units or
noncompliance with the application requirements shall be cause for
rejection.
SSPC-Paint 39
April 1, 2004
- Topcoat Adhesion to Primer: Prepare three panels according to Sections 5.1 through 5.4. Test
adhesion according to ASTM D 4541, Type III or Type IV, with three
pulls on each of the three replicate panels. At least two of the
pulls on each panel as well as the average of the three pulls on
each panel shall be at least 4.1 MPa (600 psi). 5 One pull on each
panel may be as low as 3.4 MPa (500 psi).
- Recoatability: Prepare three panels according to Sections 5.1 through 5.4. Apply
a second coat of topcoat and cure according to the manufacturer’s
recommendations. Test adhesion according to ASTM D 4541, Type III
or Type IV, with three pulls on each of the three replicate panels.
At least two of the pulls on each panel as well as the average of
the three pulls on each panel shall be at least 4.1 MPa (600 psi).5
One pull on each panel may be as low as 3.4 MPa (500 psi).
- SOLVENT RESISTANCE: Prepare three panels according to Sections 5.1 through 5.4.
Conduct a solvent resistance test on each panel in accordance with
ASTM D 5402 using 100 double rubs of MEK solvent. When viewed
without magnification, no topcoat shall be visible on the cloth.
- DRY TIME: Spray the topcoat onto a suitable test panel at the maximum
thickness recommended by the manufacturer. Test the topcoat for
Dry-Through (or Dry-To-Handle) Time in accordance with ASTM D 1640.
7.3.1 A Type 1 topcoat must be dry in less than 30 minutes.
- Physical Tests of Applied Films
- ADHESION TESTS: Adhesion properties of the polyurea topcoat shall be determined by
measurement of adhesion values between:
a) the polyurea topcoat and the primer, and if appli-cable
b) the second coat of polyurea topcoat and the same previously
applied topcoat.
The coating manufacturer shall provide an acceptable time frame
between application of coatings in a multi-coat system. Unless the
purchaser specifically requests a variance, the maximum dry film
thickness and the minimum curing time (with reported conditions for
temperature and humidity) as stated on the manufacturer’s product
data sheets shall be used for coating application prior to adhesion
testing.
7.3.2 A Type 2 topcoat must be dry in 30 minutes to 2 hours.
- WEATHERING RESISTANCE: Two weathering test procedures are described below. Test data may
not be available for the desired color and gloss specified.
Performance levels are established using whites and light colors.
Outdoor testing, as described in Section 8.1.2, is preferred. If
outdoor weathering test data is not available for the desired color
and gloss specified, accelerated test data shall be used until
outdoor weathering data becomes available. It is left to the
discretion of the specifier whether to accept outdoor data from a
similar color or to use UV-A data in lieu of outdoor weathering
data. The natural weathering site shall have a daily average total
ultraviolet radiation of 1±0.1 MJ/m2. [NOTE: Commercial test
4 The 30-day cure requirement is based on obtaining optimal
mechanical properties that may be required by some specifiers.
- It is recognized that under controlled laboratory conditions with
specific coatings, higher adhesion values (above 4.1 MPa/600 psi)
can be readily obtained. By committee consensus, a minimum
recoatibility adhesion level of 4.1 MPa (600 psi) was deemed
acceptable for testing defined in Section 5.3 based on field
experience of committee personnel and examination of other
referenced standards that have with-stood the test of time. ASTM D
5144-97, para 8.1.1 “Standard Guide for Use of Protective Coatings
in Nuclear Power Plants” and ANSI N5.12-1973, para 6.4 “Protective
Coatings (Paints) for the Nuclear Industry” both call for minimum
adhesion values of 1.4 MPa (200 psi). The minimum recoatability
adhesion value of 4.1 MPa (600 psi) specified herein is a
substantial increase over the stringent requirements of coatings
for nuclear service.
SSPC-Paint 39
April 1, 2004
TABLE 1
SUMMARY OF PERFORMANCE TESTING RESULTS TO BE REPORTED
| | | | | MEASUREMENT TEST/ |
| | | | | MINIMUM CRITERIA(b) |
| | | | Color Retention per | Maximum Gloss |
| | | | ASTM D 2244 | Reduction from Original |
| Performance | | | (Color change in | Reading per |
Exposure Test | Level | Exposure Time | | E*)(a) | ASTM D 523 |
Accelerated | Level 1A | 500 h | | 2.0 | 20% |
| | | | | |
Weathering (c) | Level 2A | 1000 h | | 3.0 | 30% |
(ASTM D 4587, | | | | | | |
Cycle 2) | Level 3A | 2000 h | | 3.0 | 40% |
South Florida | Level 1N | 12 mo | | 2.0 | 35% |
Weathering (c) | |
Level 2N | 24 mo(d) | | 3.0 | 50% |
(ASTM D 1014) | |
| | | | | |
| TEST METHOD | | | | | CRITERIA |
Solvent resistance (ASTM D 5402) | | | | | |
100 double rubs with MEK | | | no visible topcoat on cloth | |
| | | | Avg. of 3 pulls 4.1 MPa (600 psi) |
Pull-Off Adhesion (ASTM D 4541, Type III or IV) | 2 pulls, each 4.1 MPa (600 psi) |
| | | | All pulls 3.4 MPa (500 psi) |
Dry-Through (or Dry-To-Handle) Time (ASTM D 1640) | Type 1 | less than 30 minutes |
Type 2 | 30 minutes to 2 hours |
| | | |
- Smaller values of color change (less than 2.0 E*) may be visible to
the eye, but the noticeable change maximum of 3.0 E* specified
herein is deemed acceptable for most industrial and marine
applications. More stringent gloss and color retention requirements
should be specified as needed.6
- These values do not apply to deep tones and safety colors.
- Either outdoor or accelerated testing will fulfill the requirements
of this standard. The user must stipulate the type of testing to be
used. Both tests are not required unless specified.
- South Florida testing is ongoing. 24-month testing was completed in
July 2003 and testing is continuing to obtain 48-month data.
sites in North America conforming to this requirement are located
in southern Florida and Arizona.] Other test sites may be used if
agreed upon by the contracting parties. Sixty-degree specular gloss
shall be measured in accordance with ASTM D 523 and tristimulus
color measured according to ASTM D 2244 at the beginning and end of
the time period defined by the required performance level.
8.1.1 Accelerated Weathering: Triplicate test panels shall be prepared in accordance with
Sections 5.1 through 5.4. Accelerated weathering shall be performed
in accordance with ASTM D 4587, Cycle 2. Sixty-degree gloss shall
be measured according to ASTM D 523 and tristimulus color measured
according to ASTM D 2244 at the beginning and end of the time
period defined in the selected level. The coating shall meet
the weathering test requirements in Table 1 for the required
performance level.
- Level 1A: Products conforming to this performance level shall have a maximum
gloss reduction of 20% and maximum color change of 2.0 ∆E* per ASTM
D 2244 after 500 hours expo-sure.
- Level 2A: Products conforming to this performance level shall have a maximum
gloss reduction of 30% and maximum color change of 3.0 ∆E* after
1000 hours exposure.
- Level 3A: Products conforming to this performance level shall have a maximum
gloss change of 40% and a maximum color change of 3.0 ∆E* after
2000 hours exposure.
- The maximum allowable gloss reduction and color change levels for
accelerated UV-A/Condensation and Florida exposure were derived
from committee consensus, notably by resin and coating
manufacturers and users who have field and laboratory experience
and have actively participated on the SSPC Polyurethane Coatings
Committee.
8.1.2 Outdoor Weathering: Triplicate test panels shall be prepared in accordance with
Sections 5.1 through 5.4. Outdoor weathering shall be performed in
accordance with ASTM D 1014 (45-degree south exposure, washed with
mild detergent.). Sixty-degree gloss shall be measured according to
ASTM D 523 and tristimulus color measured according to ASTM D 2244
both initially and at the end of each level period. The coating
shall meet the weathering test requirements at the beginning and at
the end of the time period defined in the selected performance
level.
- Level 1N: Products conforming to this perfor-mance level shall have a
maximum gloss change of 35% and a maximum color change of 2.0 ∆E*
after a 12-month exposure.
- Level 2N: Products conforming to this perfor-mance level shall have a
maximum gloss change of 50% and a maximum color change of 3.0 ∆E*
after a 24-month exposure.
- Labeling shall conform to ANSI Z129.1.
- Technical data shall be provided for at least all data elements
categorized as “essential” in SSPC-Guide 13.
- All material supplied under this specification is subject to timely
inspection by the purchaser or an authorized representative. The
contractor shall replace such material as is found defective under
this specification (see Notes 12.5 and 12.6). In case of dispute,
unless otherwise specified, the arbitration or settlement procedure
established in the procure-ment documents shall be followed. If no
arbitration procedure is established, then a procedure mutually
agreeable to the purchaser and material supplier shall be used.
10.2 Samples of paints may be requested by the purchaser and shall be
supplied upon request, along with the manufacturer’s name and
identification for the materials. Samples may be requested at the
time the purchase order is placed, at pre-shipment, or may be taken
from unopened containers at the job site.
10.3 Unless otherwise specified, the sampling shall be in accordance
with ASTM D 3925.
SSPC-Paint 39
April 1, 2004
- While every precaution is taken to ensure that all information
furnished in SSPC standards and specifications is as accurate,
complete, and useful as possible, SSPC cannot assume responsibility
nor incur any obligation resulting from the use of any materials,
coatings, or methods specified herein, or of the specification or
standard itself.
- This specification does not attempt to address prob-lems concerning
safety associated with its use. The user of this specification, as
well as the user of all products or practices described herein, is
responsible for instituting appropriate health and safety practices
and for ensuring compliance with all governmental regulations.
Notes are not requirements of this specification.
12.1 The polyurea coatings currently used generally fall into one of
the two categories listed below. Advantages of these coatings
include: moderate or fast dry, even at low temperatures, high film
build, good abrasion and corrosion resistance, and good color and
gloss retention. The dry time can vary from minutes to hours
depending upon the formulation.
12.1.1 Hindered7 Aliphatic Polyureas (Type 2, Moderate Cure): The properties of this type of polyurea include good color
and gloss retention and controllable film builds, pot lives, and
dry times with application advantages using either conventional or
plural spray equipment. Typical dry times (to handle) range from 30
minutes to 2 hours with dry film thickness up to 15 mils per coat.
Variable pot lives range from 30 minutes to 90 minutes.
12.1.2 Non-Hindered Aliphatic Polyureas (Type 1 Fast Cure): While having good color and gloss retention, the reac-
tion rate of this type of polyurea is rapid with a short pot life
that requires plural equipment for spray application and high film
build with very fast cure and dry characteristics.
12.2 HYBRID SYSTEMS: The coating may be modified with light-stable polyols, such as
acrylics or polyesters, to form hybrid systems. Hybrid systems that
meet the performance requirements of this specification typically
contain approxi-mately 70% amine functional resins by weight solids
of the non-isocyanate co-reactants. This 70% value is not a
mandatory compositional requirement of this specification but is
offered as an informational guideline for formulation purposes.
- The term “hindered” refers to the use of a certain type of amino
reagent that tempers and retards the fast reactivity rate with an
isocyanate co-reactant during the formation of a polyurea polymer.
5
Fast or Moderate Drying, Performance-Based