ASTM D2851-98

Standard Specification for Liquid Optical Adhesive

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 5, of this specification: This standard does not purport to address all of the safety problems, 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 the Note in 6.1.1.

General Information

• Status: Historical
• Publication Date: 09-Sep-1998
• ICS: 83.180 - Adhesives
• Technical Committee: D14 - Adhesives
• Drafting Committee: D14.60 - Adhesive Material Classification System

Relations

• Replaced By: ASTM D2851-98(2004) - Standard Specification for Liquid Optical Adhesive
• Effective Date: 01-Apr-2004

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D 2851 – 98
Standard Specification for
Liquid Optical Adhesive
This standard is issued under the fixed designation D 2851; 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 (e) 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
in bonding glass to glass or other transparent adherends. information with regard to the bond strength of the adhesives.
1.2 The values stated in SI units are to be regarded as Bond strength data may be suitable for specification accep-
standard. The values given in parentheses are provided for tance, service evaluation, manufacturing control, research, and
information purposes only. development. Bond strength tests are not considered significant
1.3 The following precautionary caveat pertains only to the for applications differing widely from the test in rate and type
test method portion, Section 6, of this specification: This of loading.
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
practices and determine the applicability of regulatory limita- in order to avoid bubble formation in the adhesive layer. Each
component shall be completely reactive (without residual
tions prior to use. Specific precautionary statements are given
in the Note 1 in 6.1.1. volatile products). The adhesive may be heat-, catalyst-, or
radiation-cured.
2. Referenced Documents
5.1.1 Volatility—Volatile content of the adhesive shall not
2.1 ASTM Standards: exceed 0.5 %, unless otherwise agreed upon between the
D 542 Test Methods for Index of Refraction of Transparent manufacturer and the purchaser.
Organic Plastics 5.1.2 Viscosity—The viscosity of the adhesive shall be
D 897 Test Method for Tensile Properties of Adhesive within a well-defined range as agreed upon between the
Bonds manufacturer and the purchaser.
D 904 Practice for Exposure of Adhesive Specimens to 5.1.3 Color—The color of the adhesive shall not exceed the
Artificial (Carbon-Arc Type) and Natural Light color of a platinum-cobalt standard solution No. 300.
D 907 Terminology of Adhesives 5.1.4 Cleanliness—The number and size of foreign particles
D 1084 Test Methods for Viscosity of Adhesives found in 100 mL of the adhesive shall not exceed 5 particles in
E 308 Practice for Computing the Colors of Objects by the size range from 10 to 100 μm (0.1 mm), and none larger
Using the CIE System than 100 μm. The number and size of foreign particles in the
catalyst required to cure 100 mL of the adhesive shall not
3. Terminology
exceed 2 particles in the size range from 10 to 100 μm, and
3.1 Definitions—Many terms in this specification are de- none larger than 100 μm.
fined in Terminology D 907.
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
This specification is under the jurisdiction of ASTM Committee D-14 on
viscosity by greater than 20 % of its original viscosity nor
Adhesives and is the direct responsibility of Subcommittee D14.60 on Adhesive
show any formation of solids, when tested as described in 6.6.
Material Classification System.
Current edition approved Sept. 10, 1998. Published February 1999. Originally
5.1.7 Light Transmission—Visible light transmission
e1
published as D 2851 – 70. Last previous edition D 2851 – 86 (1993) .
through a bonded glass doublet (two glass disks bonded as
Annual Book of ASTM Standards, Vol 08.01.
described in 6.8) shall not be less than 98.5 % of the total light
Annual Book of ASTM Standards, Vol 15.06.
Annual Book of ASTM Standards, Vol 06.01. transmitted through a single glass disk. There shall be no
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 2851
change in light transmission of a glass doublet after the water. This shall be the concentrated stock solution that has a
environmental test (6.9). Pt-Co number of 500. Dilute the concentrated stock solution
5.1.8 Environmental Test—Separation within the adhesive with distilled water as shown below to obtain the desired Pt-Co
layer or from either glass surface of the glass doublet shall not standard.
exceed 1.0 mm in depth nor extend beyond 180° of the
Pt-Co Stock Solution Distilled H O
periphery of the adhesive layer (6.9).
Number of Pt-Co 500, mL to Be Added, mL
5.1.9 Bond Strength—The tensile strength of a bonded glass
500 100 0
doublet after being subjected to the environmental test (6.9) 450 90 10
400 80 20
shall be greater than 200 psi (1.38 MPa) or any value agreed
350 70 30
upon between the manufacturer and the purchaser.
300 60 40
250 50 50
200 40 60
6. Test Methods
150 30 70
100 20 80
6.1 Volatility:
75 15 85
6.1.1 Thoroughly clean three petri dish bottoms, 95-mm
50 10 90
outside diameter, by washing with detergent and a scrub brush.
0 0 100
Rinse with warm running tap water. Place petri dishes in an
air-circulating oven for 30 min at 65 6 2°C (150 6 4°F). Raise
Store the stock solutions in clean glass bottles and stopper
temperature to 110 6 2°C (230 6 4°F) for 1 h. Remove petri
them to prevent evaporation loss.
dishes from oven and place in a desiccator. After petri dishes
6.4 Foreign Particle Content—Inspect a 100-mL sample of
have cooled to room temperature, approximately 2 h, weigh
the liquid adhesive and a sample of its catalyst for cleanliness
each dish to the nearest 0.1 mg.
by filtering each through a low-form Gooch crucible fitted with
a filter membrane of 5.0 to 10.0-μm pore size and a color
NOTE 1—Precaution: In addition to other precautions, do not handle
petri dishes with bare hands. Use tongs.
suitable to easily detect and examine foreign particles. Measure
the size of the particles by means of a calibrated traversing
6.1.2 Replace each petri dish in the oven at 110 6 2°C (230
microscope (103) or other equivalent means. If the viscosity
6 4°F) for 1 h. Repeat cool-down procedure. Reweigh each
of the sample is too high, dilute it with any clean and suitable
petri dish to the near
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