ASTM D2851-15

Standard Specification for Liquid Optical Adhesive

ABSTRACT
This specification covers liquid optical adhesive for use in bonding glass to glass or other transparent adherends. The adhesive shall be in liquid form and free of solvent in order to avoid bubble formation in the adhesive layer. Each component shall be completely reactive. The adhesive may be heat-, catalyst-, or radiation-cured. Voltatility, color, viscosity, foreign particle content, refractive index, stability, light transmission, glass doublet preparation, environmental test, and bond strength tests shall be performed in accordance with the specified requirements.
SCOPE
1.1 This specification covers liquid optical adhesive for use in bonding glass to glass or other transparent adherends.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information purposes only.  
1.3 The following precautionary caveat pertains only to the test method portion, Section 6, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in 6.1.1.

General Information

• Status: Historical
• Publication Date: 31-Aug-2015
• ICS: 83.180 - Adhesives
• Technical Committee: D14 - Adhesives
• Drafting Committee: D14.60 - Adhesive Material Classification System

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D2851 − 15
Standard Specification for
1
Liquid Optical Adhesive
This standard is issued under the fixed designation D2851; 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 4. Significance and Use
1.1 This specification covers liquid optical adhesive for use 4.1 The bond strength tests provide reasonably accurate
information with regard to the bond strength of the adhesives.
in bonding glass to glass or other transparent adherends.
Bond strength data may be suitable for specification
1.2 The values stated in SI units are to be regarded as
acceptance, service evaluation, manufacturing control,
standard. The values given in parentheses are provided for
research, and development. Bond strength tests are not consid-
information purposes only.
ered significant for applications differing widely from the test
1.3 The following precautionary caveat pertains only to the
in rate and type of loading.
test method portion, Section 6, of this specification: This
standard does not purport to address all of the safety concerns, 5. General Requirements
if any, associated with its use. It is the responsibility of the user
5.1 The adhesive shall be in liquid form and free of solvent
of this standard to establish appropriate safety and health
in order to avoid bubble formation in the adhesive layer. Each
practices and determine the applicability of regulatory limita-
component shall be completely reactive (without residual
tions prior to use. Specific precautionary statements are given
volatile products). The adhesive may be heat-, catalyst-, or
in 6.1.1.
radiation-cured.
5.1.1 Volatility—Volatile content of the adhesive shall not
2. Referenced Documents
exceed 0.5 %, unless otherwise agreed upon between the
2
manufacturer and the purchaser.
2.1 ASTM Standards:
5.1.2 Viscosity—The viscosity of the adhesive shall be
D542 Test Method for Index of Refraction of Transparent
within a well-defined range as agreed upon between the
Organic Plastics
manufacturer and the purchaser.
D897 Test Method for Tensile Properties of Adhesive Bonds
5.1.3 Color—The color of the adhesive shall not exceed the
D904 Practice for Exposure of Adhesive Specimens to
color of a platinum-cobalt standard solution No. 300.
Artificial Light
5.1.4 Cleanliness—The number and size of foreign particles
D907 Terminology of Adhesives
found in 100 mL of the adhesive shall not exceed 5 particles in
D1084 Test Methods for Viscosity of Adhesives
the size range from 10 to 100 µm (0.1 mm), and none larger
E308 Practice for Computing the Colors of Objects by Using
than 100 µm. The number and size of foreign particles in the
the CIE System
catalyst required to cure 100 mL of the adhesive shall not
E1953 Practice for Description of Thermal Analysis and
exceed 2 particles in the size range from 10 to 100 µm, and
Rheology Apparatus
none larger than 100 µm.
5.1.5 Refractive Index—The refractive index of the cured
3. Terminology
adhesive shall be within a well-defined range as agreed upon
3.1 Definitions—Many terms in this specification are de-
between the manufacturer and the purchaser.
fined in Terminology D907.
5.1.6 Stability—The liquid adhesive shall not change in
viscosity by greater than 20 % of its original viscosity nor
show any formation of solids, when tested as described in 6.6.
1
This specification is under the jurisdiction of ASTM Committee D14 on 5.1.7 Light Transmission—Visible light transmission
Adhesives and is the direct responsibility of Subcommittee D14.60 on Adhesive
through a bonded glass doublet (two glass disks bonded as
Material Classification System.
described in 6.8) shall not be less than 98.5 % of the total light
Current edition approved Sept. 1, 2015. Published September 2015. Originally
transmitted through a single glass disk. There shall be no
approved in 1970. Last previous edition approved in 2015 as D2851 – 98 (2015).
DOI: 10.1520/D2851-15.
change in light transmission of a glass doublet after the
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
environmental test (see 6.9).
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
5.1.8 Environmental Test—Separation within the adhesive
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. layer or from either glass surface of the glass doublet shall not
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D2851 − 15
exceed 1.0 mm in depth nor extend beyond 18
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This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D2851 − 98 (Reapproved 2015) D2851 − 15
Standard Specification for
1
Liquid Optical Adhesive
This standard is issued under the fixed designation D2851; 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
1.1 This specification covers liquid optical adhesive for use in bonding glass to glass or other transparent adherends.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information
purposes only.
1.3 The following precautionary caveat pertains only to the test method portion, Section 6, of this specification: This standard
does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this
standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Specific precautionary statements are given in 6.1.1.
2. Referenced Documents
2
2.1 ASTM Standards:
D542 Test Method for Index of Refraction of Transparent Organic Plastics
D897 Test Method for Tensile Properties of Adhesive Bonds
D904 Practice for Exposure of Adhesive Specimens to Artificial Light
D907 Terminology of Adhesives
D1084 Test Methods for Viscosity of Adhesives
E308 Practice for Computing the Colors of Objects by Using the CIE System
E1953 Practice for Description of Thermal Analysis and Rheology Apparatus
3. Terminology
3.1 Definitions—Many terms in this specification are defined in Terminology D907.
4. Significance and Use
4.1 The bond strength tests provide reasonably accurate information with regard to the bond strength of the adhesives. Bond
strength data may be suitable for specification acceptance, service evaluation, manufacturing control, research, and development.
Bond strength tests are not considered significant for applications differing widely from the test in rate and type of loading.
5. General Requirements
5.1 The adhesive shall be in liquid form and free of solvent in order to avoid bubble formation in the adhesive layer. Each
component shall be completely reactive (without residual volatile products). The adhesive may be heat-, catalyst-, or
radiation-cured.
5.1.1 Volatility—Volatile content of the adhesive shall not exceed 0.5 %, unless otherwise agreed upon between the
manufacturer and the purchaser.
5.1.2 Viscosity—The viscosity of the adhesive shall be within a well-defined range as agreed upon between the manufacturer
and the purchaser.
5.1.3 Color—The color of the adhesive shall not exceed the color of a platinum-cobalt standard solution No. 300.
1
This specification is under the jurisdiction of ASTM Committee D14 on Adhesives and is the direct responsibility of Subcommittee D14.60 on Adhesive Material
Classification System.
Current edition approved April 1, 2015Sept. 1, 2015. Published April 2015September 2015. Originally approved in 1970. Last previous edition approved in 20092015 as
D2851 – 98 (2009).(2015). DOI: 10.1520/D2851-98R15.10.1520/D2851-15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D2851 − 15
5.1.4 Cleanliness—The number and size of foreign particles found in 100 mL of the adhesive shall not exceed 5 particles in the
size range from 10 to 100 μm (0.1 mm), and none larger than 100 μm. The number and size of foreign particles in the catalyst
required to cure 100 mL of the adhesive shall not exceed 2 particles in the size range from 10 to 100 μm, and none larger than
100 μm.
5.1.5 Refractive Index—The refractive index of the cured adhesive shall be within a well-defined range as agreed upon between
the manufacturer and the purchaser.
5.1.6 Stability—The liquid adhesive shall not change in viscosity by greater than 20 % of its original viscosity nor show any
formation of solids, when tested as described in 6.6.
5.1.7 Light Transmission—Visible light transmission through a bonded glass doublet (two glass disks bonded as described in
6.8) shall not be less tha
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