ASTM D6411/D6411M-99(2020)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D6411/D6411M −99(Reapproved 2020)
Standard Specification for
Silicone Rubber Room Temperature Vulcanizing Low
Outgassing Materials
This standard is issued under the fixed designation D6411/D6411M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 Thespecificationcoversatwo-partflowablespacegrade
B209 Specification for Aluminum and Aluminum-Alloy
room temperature vulcanizing (RTV) silicone rubber adhesive
Sheet and Plate
or compound. The material is specifically designed for appli-
D149 Test Method for Dielectric Breakdown Voltage and
cations requiring extreme low temperature, low outgassing and
DielectricStrengthofSolidElectricalInsulatingMaterials
minimal volatile condensibles under extreme operating condi-
at Commercial Power Frequencies
tions. The RTV silicone rubber should be suitable for with-
D150 Test Methods forAC Loss Characteristics and Permit-
standing environmental exposure to temperatures from –115 to
tivity (Dielectric Constant) of Solid Electrical Insulation
200°C (–175 to 392°F).The material should also withstand the
D257 Test Methods for DC Resistance or Conductance of
combination of stress, temperature, and relative humidity
Insulating Materials
expectedtobeencounteredinservice.TheRTVsiliconerubber
D412 Test Methods forVulcanized Rubber andThermoplas-
may be used as a sealing, caulking, potting or bonding material
tic Elastomers—Tension
for applications on metal, plastics, rubber, glass, and ceramic
D792 Test Methods for Density and Specific Gravity (Rela-
products. Types I and II are often used as coatings.
tive Density) of Plastics by Displacement
1.2 The values stated in SI units or inch-pound units are to
D907 Terminology of Adhesives
be regarded separately as standard. Within the text, the
D1002 Test Method for Apparent Shear Strength of Single-
inch-pound units are shown in brackets. The values stated in
Lap-Joint Adhesively Bonded Metal Specimens by Ten-
each system are not exact equivalents; therefore, each system
sion Loading (Metal-to-Metal)
must be used independently of the other. Combining values
D1084 Test Methods for Viscosity of Adhesives
from the two systems may result in nonconformance with this
D2240 Test Method for Rubber Property—Durometer Hard-
specification.
ness
D2651 GuideforPreparationofMetalSurfacesforAdhesive
1.3 The following precautionary statement refers to the test
Bonding
method portion only, Section 8, of this specification: This
D3951 Practice for Commercial Packaging
standard does not purport to address all of the safety concerns,
E595 Test Method for Total Mass Loss and Collected Vola-
if any, associated with its use. It is the responsibility of the user
tile Condensable Materials from Outgassing in a Vacuum
of this standard to establish appropriate safety, health, and
Environment
environmental practices and determine the applicability of
regulatory limitations prior to use.
2.2 National Aeronautics and Space Administration
1.4 This international standard was developed in accor-
(NASA):
dance with internationally recognized principles on standard-
JSC SP-R-0022 General Specification, Vacuum Stability
ization established in the Decision on Principles for the Requirement of Polymeric Material for Spacecraft Appli-
Development of International Standards, Guides and Recom-
cation
mendations issued by the World Trade Organization Technical MSFC-HDBK-527/JSC-09604 Material Selection List for
Barriers to Trade (TBT) Committee.
Hardware Systems
1 2
This specification is under the jurisdiction of ASTM Committee D14 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Adhesives and is the direct responsibility of subcommittee D14.80 on Metal contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Bonding Adhesives. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Jan. 1, 2020. Published January 2020. Originally the ASTM website.
approved in 1999. Last previous edition approved in 2012 as D6411/D6411M – 99 Unless otherwise indicated, copies of the above documents are available from
(2012). DOI: 10.1520/D6411_D6411M-99R20. a NASA installation library or document repository.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6411/D6411M−99(2020)
GSFC RP 1124 Outgassing Data for Selecting Spacecraft 6. Ordering Information
Materials
6.1 Procurement Documents—Purchasers may select any of
the desired options offered herein and the procurement docu-
NOTE1—Copiesofspecifications, standards, drawings and publications
required by suppliers in connection with specific purchases should be
ments should specify the following:
obtained from the purchaser or as directed by his contracting officer.
6.1.1 Title, number and dated revision of this specification,
6.1.2 RTV silicone rubber material type and number,
3. Terminology
6.1.3 AmountsandunitquantitiesofRTVrubbercompound
3.1 Definitions:
required,
3.1.1 Many terms in this specification are defined in Termi- 6.1.4 Curing conditions,
nology D907.
6.1.5 Level of packaging and packing required,
3.1.2 lot, n—a specific material that can be identified by the
6.1.6 Whether or not qualification is necessary, and
place of manufacture, quantity and type of raw materials and
6.1.7 Storage conditions.
process conditions used.
6.2 Qualification—In case the RTV silicone rubber com-
3.2 Definitions of Terms Specific to This Standard:
pound(s) that are qualified/approved at the time set for opening
3.2.1 RTV, adj—room temperature vulcanizing.
of bids, the procurement documents should state that the
awards will be forthcoming.
3.2.2 RTV Silicone Rubber Compound, n—a silicone resin
base (A) and a silicone resin curing agent (B) when mixed in a
7. Test Requirements
proper ratio results in a rubbery compound. A RTV silicone
rubber compound that is manufactured by a unique combina-
7.1 Material—The RTV silicone rubber compound, when
tion of raw silicone materials and manufacturing process that
tested per Section 8, shall meet the physical, mechanical and
conforms to a given set of physical and performance properties
electrical, and outgassing requirements as specified in Table 1.
and is identified by specific name, number, or alphanumeric
The silicone rubber compound shall not have a detrimental
designation.
effect on surfaces being in contact or bonded over the range of
temperaturesatwhichtheRTVsiliconerubbercompoundswill
NOTE 2—A“curing agent” is commonly used with this type of silicone
be used.
rubber compound. The term “accelerator” or “catalyst” is synonymous
with “curing agent.”
7.2 Qualification—Qualification shall only apply to the
formulation on which the qualification tests have been made;
4. Significance and Use
any changes by the manufacturer in formulation or method of
manufacturing, shall be cause of designating the RTV silicone
4.1 General—This specification provides material require-
rubber compound as a new product. The new product shall be
ments and testing procedures to differentiate between the
givenanewcodenumberandshallberequalifiedandapproved
physical, mechanical, electrical, adhesive bonding properties
until it has been shown to meet the requirements of this
of three types of RTV silicone rubber compounds.
specification.
4.2 Thephysical,mechanicalandelectricalpropertiesofthe
7.3 Working Characteristics:
RTV silicone rubber are tested and measured to provide
7.3.1 Application—The RTV silicone rubber compound
specific data on requirements for qualification and lot accep-
shall be suitable for application to surfaces in accordance with
tance of separate ingredients comprising the RTV silicone
the manufacturer’s instructions.
rubber compounds and the properties resulting from the cured
7.3.2 Curing—The time, temperature, and pressure used to
mixture.
cure the RTVsilicone rubber compound shall be in accordance
NOTE 3—Because of the many number of adherend materials bonded
with the manufacturer’s recommendation.
with RTV silicone rubber material, testing by this specification will only
evaluate the RTV silicone rubber material under a given set of conditions.
8. Test Methods
5. Classification
8.1 Qualification Tests—For qualification, the RTV silicone
rubber compound shall be tested using the tests described in
5.1 The RTV low volatile silicone rubber compounds shall
this section.All tests specified in Table 1 shall be performed at
be furnished as one of the following types:
room temperature, 25 6 3°C [77 6 5°F] with the exception of
5.1.1 Type I—Alow viscosity, two-part system consists of a
the outgassing test.
silicone resin base (A) and a liquid curing agen
...