ThreeBond Technical News
Issued January 1, 2021

97

Initiatives for Environmentally Friendly Products(HFO-1234yf, New Refrigerant for Automotive Air Conditioning)
Introduction

Automotive air conditioning draws power from the engine of the vehicle. This means that increases
in efficiency can lead to improved fuel economy and a reduction in fossil fuel consumption.
ThreeBond released ThreeBond 6905 High Performance Lubricant Agent For Car Air Conditioner
to improve the efficiency of automotive air conditioning systems. This product has been wellreceived by a large number of customers.
ThreeBond 6905 contains HFC-134a as a substitute for chlorofluorocarbons (CFCs), the useof which was regulated by the Montreal Protocol in order to protect the ozone layer. However,while the ozone depletion potential (ODP) of hydrofluorocarbons (HFCs) is low, the 2016 Kigali
Amendment states that they have a high global warming potential (GWP). As a result, a phased
reduction of the production and consumption of HFCs was imposed as of 2019.
In 2019, ThreeBond released ThreeBond 6905B Solstice® yf Refrigerant for Car Air Conditioner.
This canned refrigerant for automotive air conditioning contains HFO-1234yf, an environmentallyfriendly refrigerant gas with a low global warming potential.
In addition, ThreeBond 6905C, in which the refrigerant gas used in ThreeBond 6905 has been
replaced with HFO-1234yf, is scheduled for release in 2021.
This article explains the operation of automotive air conditioning, global efforts to protect theenvironment, and the necessity of lubricants.
Hereafter, ThreeBond is abbreviated as TB.

Table of Contents

Introduction.................................................1
1. Automotive Air Conditioning...................2
2. Refrigerant Gas.......................................2
3. Regulation of Fluorocarbons (CFCs).......3

4. HFO-1234yf.............................................4
5. Lubricant.................................................6
Closing........................................................81

1.

Automotive Air Conditioning

The flow of refrigerant gas through an automotive air
conditioning system is shown in Figure 1.
Aluminumpipe

Refrigerant gas
Refrigerant gas

High pressure
hose (vibration
absorption)
Aluminumpipe

Evaporator
Cooling due toheat of vaporizationof refrigerant

Expansion valve
Reducedpressure, reduced
Refrigerant
temperaturegas

Condenser
Condensation
into liquid causedby heat radiation
ReceiverRefrigerant volume
adjustment
Air separation
Removal of waterand foreign objects

High temperature

Liquid tube

Fig. 1 Flow of Refrigerant Gas

The main components of an automotive air conditioning
system are:(1) Compressor: Suction compressor for refrigerant gas(2) Condenser: Heat exchanger that uses air (or water)in the surrounding area to cool, condensing the highpressure refrigerant gas(3) Evaporator: Heat exchanger that evaporates the lowtemperature liquid refrigerant, cooling the air sent
into the vehicle interior(4) Expansion valve: Controls the flow of refrigerant(5) Pipes connecting the above parts
Cooling is achieved by exchanging heat with the surroundingarea through changes in the state of matter. A theoreticalexample of cooling is shown in Figure 2.
Direction ofrefrigerant flowHightemperature,high pressure
Pressure
reduction
Low
temperature,
low pressure

Condensation

Condenser
Compression
Aperture
resistance

Evaporation

Compressor
Evaporator

Heatabsorption

Fig. 2 Theoretical Example of Cooling 1)

According to the first law of thermodynamics ΔU = Q + W,
where ΔU is the change in the internal energy of the system,
Q is the quantity of energy supplied to the system fromoutside as heat, and W is the amount of thermodynamic work
done from outside the system. When adiabatic compression
occurs, Q = 0, and consequentially ΔU = W.

2

Isotherm
AdiabatVolume (V)Fig. 3 Isotherm and Adiabat

When the heated gas (refrigerant) is cooled from outside
the system by air or water, it condenses into a liquid (in thecondenser). The condensed refrigerant is decompressed by
the aperture resistance and becomes low temperature, lowpressure liquid refrigerant. This liquid is then continuously
returned, enabling cooling. At the aperture, the temperature
reduction causes part of the high temperature liquid
refrigerant to vaporize, cooling part of the refrigerant itself.
It is then sent as cold liquid to the evaporator, where cooled
air is supplied to the vehicle interior.

2.
Heatradiation

Crosses to the high temperatureside of the isotherm
Temperature increase

Pressure (P)Compressor
Temperature
increase due toadiabatic
compression

Low pressure
hose (vibration
absorption)

The internal energy of n moles of an ideal monoatomic
gas is given by U = 3/2nRT (R: universal gas constant).
Therefore, when ΔU = W, the work done from outside thesystem is converted into the thermal energy of the gas. Thismeans that work done from outside the system with a piston(the compressor) while the system is in an adiabatic state
causes the temperature of the gas to increase. Figure 3 uses
PV curves to show the increase in pressure due to adiabatic
compression.

Refrigerant Gas

Table 1 shows the characteristics of some of the mainrefrigerants used for automotive air conditioning.
Refrigerant gas must have a low boiling point in order todraw heat from the surrounding area by vaporizing rapidly
in the evaporator after passing through the expansion valve,
thereby cooling the air in the vehicle interior. In addition,
when replacing the refrigerant gas, greater similarity in thetemperature characteristics in relation to pressure of the oldand new gases means that fewer changes are needed to theexisting mechanisms. This facilitates mechanical design.
In this way, the fact that refrigerant gases are substancesthat form the basis of the cooling functions of automotive
air conditioning places a number limitations on thephysiochemical properties that they can exhibit. They arealso extremely important substances in terms of protecting
the environment. The following aspects are important
requirements to be considered when selecting a refrigerant.

Table 1 Characteristics of Main Refrigerants for Automotive Air Conditioning
Refrigerant
CFC-12

Boiling point
at 1 atm (℃)-29.7

Pressure at 0℃
(MPa)
0.31

Heat of vaporization
at 0°C (kJ/kg)
151.4

Remark(s)Causes damage to the ozone layer

HFC-134a

-26.1

0.29

198.7

Greenhouse gas

HFO-1234yf

-29.0

0.29

145.2

Environmentally-friendly refrigerant

Water

100.0

0.00062502.8Reference(1) Safety
Air conditioning is now an integral part of everyday
life. Refrigerants must have low toxicity andflammability based on the assumption that there isa risk of leaks in the case of an accident or natural
disaster.
(2) Environmental impact
Refrigerants must have a low ozone depletion
potential (ODP) and global warming potential (GWP),
two values that measure the direct environmental
impact of a substance. Ease of collection after use andrecycling are also important considerations.
(3) Energy efficiency
Related to environmental impact, the production of
the refrigerant gas must not consume large quantities
of energy, require the use of a large amount of fossil
fuels or generate large quantities of carbon dioxide,
which is a greenhouse gas. The ideal refrigerant gas

can be produced at low energy cost and has highenergy efficiency during use.
(4) Economy
The refrigerant must be low cost, be readily available
all over the world, be easy to perform maintenanceon, not require the implementation of excessive safetymeasures, and be recyclable at low cost.

3.

Regulation of Fluorocarbons (CFCs)

In 1974, Dr. Frank Sherwood Rowland and Dr. Mario José
Molina Henríquez of the University of California publisheda paper in the journal Nature highlighting the ozone
layer destruction caused by chlorofluorocarbons (CFCs).
This paper sparked a large national debate in the USA,
eventually resulting in the regulation of fluorocarbon gases.
An overview of initiatives, tightening of regulation, andlegislation relating to the use of fluorocarbon gases in Japanand around the world is shown in Table 2.

Table 2 History of Fluorocarbon Gas Regulation 1), 2), 3)
Year
1977

Major developments
Dr. Frank Sherwood Rowland and Dr. Mario José Molina Henríquez of the University of California, USA identify ozone depletioncaused by fluorocarbons as a cause for concern.
The United Nations Environment Program (UNEP) decides to examine the issue of fluorocarbon regulation.

1978

The manufacture of aerosol products that use fluorocarbons as propellants is prohibited in the USA.

1979

Aerosol products containing fluorocarbons are prohibited in Canada and northern Europe.
The European Community (EC) recommends the freezing of CFC-11 and CFC-12 production, and that efforts be to reduce the useof fluorocarbons in aerosol products. Japan follows suit.
The UNEP Vienna Convention for the Protection of the Ozone Layer is signed.

1974

1980
1985
1987

The Montreal Protocol on Substances that Deplete the Ozone Layer is adopted and enters into effect in January 1989.
In Japan, the Act on the Protection of the Ozone Layer Through the Control of Specified Substances and Other Measures(Ozone Layer Protection Act, Act on the Control of CFCs and Other Substances) is passed and enters into effect. The total
1988 abolition of halon from 1994, the total abolition of CFCs, 1,1,1-trichloroethane and HBFCs from 1996, the total abolition of
bromochloromethane from 2002, the total abolition of methyl bromide (with some exceptions for specific uses) from 2005, thephased reduction in the use of HCFCs up to 2020, and the total abolition of HCFCs from 2020 are agreed.
The Japanese Ministry of the Environment and Ministry of International Trade and Industry publish Guidelines for Reducing
1989
Emissions from and Rationalizing the Use of CFCs.
The Cabinet Order Regarding Exceptions to Fluorocarbon Refrigerant Collection, Purification and Recycling Equipment is revised
1990
and a notification is issued.
The Fourth Meeting of the Parties to the Montreal Protocol is held in Copenhagen. It is agreed to move the deadline for the
discontinuation of CFC production forward to the end of 1995, and the regulation of HCFC production and the discontinuation
1992
of HCFC production by 2020 are agreed in principle. The United Nations Framework Convention on Climate Change enters into
effect in 1994.
1996 The production of CFCs is abolished in developed countries.
The Kyoto Protocol is adopted. Regulations on alternative fluorocarbons with a high global warming potential are adopted.
1997
Legally-binding numerical targets are established.
From Japan: The Act on Recycling of Specified Home Appliances, the Act on Promotion of Global Warming Countermeasures, the1998 Fluorocarbons Recovery and Destruction Act, and the End-of-Life Vehicle Recycling Law are established. The Kyoto Protocol is ratified.
2000 The Japanese Green Purchase Act is established.
2006 The Japanese Fluorocarbons Recovery and Destruction Act is revised.
The Japanese Fluorocarbons Recovery and Destruction Act is revised (the revised Fluorocarbons Act is published). It enters into
2013
effect in April 2015.
2015 The Paris Agreement is adopted. Global efforts are made by all signatory countries.
The Kigali Amendment to the Montreal Protocol is agreed. Gradual reductions through the regulation of alternative fluorocarbons
2016
are decided.
2020 The revised Fluorocarbon Emissions Control Act enters into effect.

3

As a result of these tightening regulations, it was establishedthat fluorocarbon consumption as of January 1994 must notexceed 25% of 1986 levels. The production of CFCs wasthen completely abolished in developed countries in 1996.
Major CFCs, alternative fluorocarbons and environmentallyfriendly refrigerants are shown in Table 3. It has been
pointed out that alternative fluorocarbons such as HFC-134a,
which is currently the main refrigerant used in automotive
air conditioning, have a low ODP but an extremely high
GWP. In response to this, the shift to the use of HFO1234yf as a refrigerant for automotive air conditioning has
been accelerating worldwide since the early 21st century.
Domestically-produced Japanese automobiles have been
gradually transitioning in line with model changes sincearound 2018, and replacement had been complete in about
10% to 40% of vehicles produced by each automobile
manufacturer as of the end of September 2020. The schedule
for the phased reduction of alternative fluorocarbons set by
the Japanese Ministry of Economy, Trade and Industry and
Ministry of the Environment is shown in Figure 4. The
target is a 10% reduction from 2019 levels in FY2020 and a
40% reduction from 2019 levels in FY2025.

7,152(Baseline
value (100％))

Unit:
10,000CO2-t−10%Approx.
4,900

−40%

−70%
Projected use in Japan
based on the Fluorocarbon
Emissions Control Act

−80%

−85%

* Baseline value: Calculated from the average value of 2011-2013
results

Fig. 4 Schedule for the Reduction of Alternative
Fluorocarbons in Japan 4)

Table 3 ODP and GWP of Major CFCs, Alternative
Fluorocarbons and EnvironmentallyFriendly Refrigerants 3)
Classification

Name

CFC-11
CFC-12
CFCs
CFC-113
CFC-114
CFC-115
HCFC-22
HCFC-141b
HCFC-142b
HFC-23
HFC-32
Alternative
HFC-125
fluorocarbons
HFC-134a
HFC-143a
PFC-14
PFC-116
SF6
Environmentally- HFO-1234yf
friendly refrigerant HFO-1234ze(E)4.

HFO-1234yf

GWP(IPCC Fourth
ODP
Assessment
Report)1
4,750
110,9000.8
6,130
110,000
0.5
7,370
0.055
1,810
0.11
725
0.065
2,310
0
14,800
0
675
0
3,500
0
1,430
0
4,470
0
7,390
0
12,200022,800
0
1
0
1

HFO-1234yf (hydrofluoroolefin-1234yf, CF3CF=CH2), also
known as 2,3,3,3-tetrafluoro-1-propene, is a colorless,transparent liquefied gas with a molar mass of 114 g/mol.
It is a mildly flammable gas with a low boiling point of-29.0°C. Its basic structure is shown in Figure 5.

4

Fig. 5 Structural Formula of 2,3,3,3-Tetrafluoro1-propene

HFO-1234yf is mainly used as a refrigerant for automotive
air conditioning and has the following characteristics 1).
• Low toxicity• Good thermal stability• ODP = 0, GWP = 1 (there are some reports that GWP= 4, however, this is still approximately the same asthat of CO2)
• Similar in nature to HFC-134a, with a difference incooling performance and energy efficiency of less than5%
• Supports direct expansion systems, no secondaryrefrigerant required• Compatible with configurations and materials used as
standard in conventional automotive air conditioning
systems
A comparison of the physical properties of HFC-134a and
HFO-1234yf is shown in Table 4. In general there are no
major differences, however, HFO-1234yf has a significantly
lower GWP.
PT curves for HFO-1234yf and HFC-134a are shown in
Figure 6. The values for pressure response to temperatureshow similar values for each temperature range, indicatinghigh mutual compatibility with equipment.

Table 4 Physical Property Comparison of
HFC-134a and HFO-1234yf 5)
Molecular structure
Molar mass

Unit

HFC-134a—

HFO-1234yf

CF3CH2F CF3CF=CH2

g/mol

102.0

114.0

Critical temperature

°C

101.1

94.7

Critical pressure

MPa

4.1

3.4

Freezing point°C-101.0N.D.

Normal boiling point

°C

-26.1

-29.0

Vapor pressure (at 25°C)

kPa

Vapor density (at 25°C)

kg/m

665.0

685.0

3

32.4

38.1

Liquid density (at 25°C) kg/m3

1207.01091.0

kJ/kg

177.8

145.2

Heat of vaporization(at 25°C)
Heat capacity ratio(at 25°C, 1 atm)

Water solubility (at 25°C)

—

1.1

1.1

Flammability range(High Pressure Gas
Safety Act - Class A)

ppm

0.1

N.D.

vol%

No flame
propagation

6.3-14.0

Burning velocity

cm/s

1.5

ODP

—

No flame
propagation

GWP (IPCC AR5)

0.0

0.0

—

1430.0

1.0

Atmospheric lifespan

Days

14.6

11.0

ASHRAE classification

—

A1

A2L

While HFO-1234yf has similar physical properties to
HFC-134a, it is flammable and therefore presents problems
in terms of safety during handling. In consideration ofsubstances such as HFO-1234yf, the USA-based American
Society of Heating, Refrigerating and Air-Conditioning
Engineers (ASHRAE) established a new classification of
mildly flammable gases (Class 2L) for flammable gases witha lower flammability limit of greater than 0.1 kg/m3, a heatof combustion of less than 19,000 kJ/kg and a maximum
burning velocity of 10 cm/s or less. ISO 817:2014 refrigerant
flammability classifications with representative examples ofrefrigerants are shown in Table 5.
In Japan, flammability risk is mainly evaluated byorganizations such as the Japan Society of Refrigeratingand Air Conditioning Engineers (JSRAE), the Japan
Refrigeration and Air Conditioning Industry Association

Pressure (kPa)Item

Temperature (°C)

Fig. 6 PT Curves of HFC-134a and HFO-1234yf 5)
Inert gases
N2, Ar, CO2, etc.
Fluorocarbons classified
as inert gases
HCFC-22
HFC-407C
HFC-134a
R-410B, etc.
HFC-404A
Specified inert gases
HFC-32
HFO-1234yf
HFO-1234ze

Fig. 7 Overview of Inert Gases, Fluorocarbons
Classified as Inert Gases and Specified
Inert Gases(JRAIA), and the New Energy and Industrial Technology
Development Organization (NEDO). While there was not
originally a definition of mild flammability given by theJapanese High Pressure Gas Safety Act, the handling of
mildly flammable refrigerants has been clarified following
requests from the JRAIA. Since the revision of the law in2016, HFO-123 4yf has been classified as a specified inert
gas, meaning that it is flammable but extremely low risk.
An overview of inert gases, fluorocarbons classified as inert
gases and specified inert gases is shown in Figure 7.
Following the restriction of the use of HFC-134a in accordancewith the Mobile Air Conditioning (MAC) Directive issued
by the EU in 2006, which states that the global warming
potential of refrigerants used in air-conditioning systems
for passenger cars and light commercial vehicles must
not exceed 150, HFO-1234yf was developed and put into

Table 5 ISO817:2014 Refrigerant Flammability Classifications with Representative Examples 6)
Flammability class

Definition

Representative refrigerant

Class 3 (highly flammable)

LFL ≤ 3.5 vol% or HC ≤ 19 MJ/kg

R-290, R-600a4.5

Class 2 (flammable)

LFL > 3.5 vol% and HC < 19 MJ/kg

R-152aClass 2L (mildly flammable)

In Class 2, Su,max ≤ 10 cm/s

R-717, R-32, R-143a,
R-1234yf, R-1234ze (E)Class 1 (no flame propagation)

No flame propagation

R-134a, R-410A, R-22
*R-: refrigerant5practical use by Honeywell and DuPont. AGC established amanufacturing method in 2014 and started supplying HFO1234yf to Honeywell.
In Europe, HFC-134a has been phased out in all new models
since January 2011, and its use in all new vehicles has beenbanned since January 2017.
Similarly, a bill regulating the use of HFC-134a wassubmitted in the USA, and reductions in use for automotive
air conditioning and general industrial applications havebegun. The US Environmental Protection Agency (EPA)
allows automobile manufacturers to earn credits forgreenhouse gas reduction by adopting HFO-1234yf. (CAFE:
Corporate Average Fuel Economy)
This issue is also being considered by the Global Warming
Prevention Measures Subcommittee of the Industrial
Structure Council Biochemical Policy Committee in Japan,and HFO-1234yf has been put into practical use sincearound 2018.

5.

Lubricant

The flow of refrigerant through automotive air conditioning
systems includes sliding parts such as those in thecompressor. Lubricating oil is therefore used along the flow
path to improve mechanical efficiency. The oil not only
lubricates sliding parts, but also serves as a seal for gaps
in the operating chamber and connections between parts
such as pipes. The compression diagram of a reciprocating
compressor is shown in Figure 8.
Piston top
dead center

Dischargepressure loss

4→1 shows the process by which the inside of the operating
chamber reaches the suction pressure, and new refrigerantgas pushes the suction valve open and is sucked into theoperating chamber.
While the solid line shows an ideal cycle, the actual process
is as indicated by the dotted line. This difference is due topressure loss, refrigerant gas leakage, friction, and heatloss. Lubricants are used to reduce losses of efficiency due
to friction on these sliding parts.
In addition, while the parts of the refrigerant flow path are
generally connected by aluminum piping, hosing is used toconnect parts where different vibration systems are used,such as the piping of the compressor and the condenser.
Although each connection is sealed with an O-ring or
similar part, minute gaps are unavoidable. By permeatingthese gaps, lubricating oil also prevents the outflow of gas.
While more oil provides better lubrication, oil that circulateswith the refrigerant has a negative effect on cooling
performance. For this reason, the oil in circulation must beof an appropriate type and volume. In general, oil used in
automotive air conditioning requires the following basic
qualities.
(1) Appropriate viscosity(2) High flash point(3) Low pour point(4) Excellent oxidative stability(5) Little effect on organic materials such as O-rings andrubber hoses(6) High oil film strength

Pressure (P)(7) Low water content

Loss due to leakage
and overheating

Suction pressure loss

Piston lower
dead center

Volume (V)Ideal curve
Actual curve

Fig. 8 Pressure Inside Compressor

1→2 shows a gas with suction pressure of Ps being
compressed to a discharge pressure of Pd.
2→3 shows this gas reaches the top dead center of the piston
while being discharged to the high pressure side, remaining
at a pressure of Pd.
3→4 shows the process of the gas with a volume of Vd
remaining at the top dead center of the piston (3) expanding
to a suction pressure of Ps (4). (Re-expansion stroke)

6(8) Does not cause a chemical reaction with therefrigerant(9) Excellent compatibility with the refrigerant(10) Excellent defoaming properties
The basic performance characteristics of TB6905C areshown in Table 6. As TB6905C is in the proper viscosity
range, it can reduce resistance due to friction whileremaining on sliding parts. This restores the mechanicalefficiency of the compressor to a state similar to that of a
new vehicle. The base oils polyalkylene glycol (PAG) andpolyol ester (POE) have a flash point of approximately 220
to 300°C. TB6905C has a flash point equal to or greaterthan these oils. This means that there is no increased risk ofaccidents even when the compressor causes the temperature
to rise. In addition, the low pour point of TB6905C ensuresthat there are no concerns about freezing or crystallizationin cold regions.
The insulation stability of TB6905C when mixed with wateris shown in Table 7. TB6905C maintains a high dielectric
breakdown voltage and volume resistivity even when mixed
with a small quantity of water.

Table 8 shows the hydrolysis stability (change in acidvalue) of TB6905C over time when mixed with water. It
was confirmed that TB6905C exhibits excellent hydrolysis
resistance, and no change in acid value was observed
compared to the initial value.

Figure 9 shows the results of an SRV (Schwingung, Reibung
und Verschleiss) vibration, friction and abrasion test under
ASTM D6425 conditions. It was confirmed that by adding
TB6905C to POE oil provided a low, stable coefficient offriction in each temperature range.

* The values in Tables 7 and 8 show the stability of the
product when mixed with a small quantity of water anddo not guarantee the prevention of abnormalities when
the product is mixed with water.

Table 9 shows the abrasion prevention properties exhibited
through the results of a Falex test (the abrasion tester isoperated while bubbling the liquid with HFO-1234yf). It
was confirmed that adding TB6905C to POE oil improves
load resistance and reduces wear.

Table 6 Basic TB6905C Performance Characteristics
Item

Unit

General requirement

TB6905C

Kinematic viscosity (at 40°C)

mm /s

90~11095.38

Kinematic viscosity (at 100°C)

mm /s

—

10.53

Flash point℃

180 or more

276

Pour point℃-10.0 or less

-30

Acid value

mgKOH/g

—

0.01

2
2

Chemical stability with refrigerant

Color scale (ASTM)

5.0 or less1

Dielectric breakdown voltage (at 2.5 mm)

kV

24 or more70

Volume resistivity (at 80°C)Ω•m—

45 × 1012

Table 7 Insulation Stability of TB6905C when Mixed with Water
Item

Unit

No water added

When mixed with
500 ppm of water

When mixed with1,000 ppm of water

Dielectric breakdown voltage (at 2.5 mm)

kV

70

68

65

Volume resistivity (at 80°C)Ω•m

45 × 10

Table 8 Hydrolysis Stability (Change
in Acid Value) of TB6905C

23 × 1012

12

PB6905C

POE oil0 daysmgKOH/g

0.01

0.02

7 daysmgKOH/g

0.01

0.04

14 days

mgKOH/g

0.01

0.17

30 days

mgKOH/g

0.01

4.5

Test conditions: In accordance with the JIS K 2211 refrigeratingmachine oils testing method for chemical
stability to refrigerant (sealed tube test)
Test solution: Base oil (7 mg) + HFO-1234yf (3 mg)
Temperature: 175°C
Water:
1,000 ppm
Catalyst:
Fe, Al, Cu

Table 9 Abrasion Prevention Test Results
Item

Unit

POE oil

When TB6905C
is added

Load resistance*1

Lbf

1010

1260

Abrasion*2

mg

5.8

4

*2 Test conditions
Temperature:
40°C
Rotational speed: 300 rpm
Gas injection rate: 70 mL/min

Temperature (°C)

Unit

Coefficient of friction

Break-inDays after
addition of water*1 Test conditions
Temperature:
60°C
Rotational speed: 300 rpm
Gas injection rate: 70 mL/min

34 × 10

12

Time (min)Temperature

Weight:Amplitude:
Frequency:
Temperature:
Time:
Test pieces:

POE oil

When TB6905C
is added

200 N (break-in: 50 N)
1.5 mm
50 Hz
10°C/5 min (break-in: 30°C)
30 min (break-in: 5 min)
Cylinder, plate

Fig. 9 SRV Test Results Before and After Addition of
TB6905C

7

Closing

In this article, we covered ThreeBond’s environmental protection efforts with regards to automobiles and related products. In
addition, ThreeBond is also developing products in a wide range of fields, including cleaning solvents with improved safety andlow GWP, and coating agents that use these cleaning solvents. These products are scheduled to be released in the near future.
ThreeBond will contribute to technological innovation in global industry and environmental conservation by focusing on
product and technology development in line with market trends. The company will also continue to ensure that it provides
safety and peace of mind to all concerned parties through its business activities.
<References>
1) Automotive Air Conditioning Study Group (supervised by Fujiwara, Kenichi). Automotive Air Conditioning,
Automotive Engineering Series, SANKAIDO PUBLISHING Co., Ltd. (Initial publication: 2001, 2nd edition: 2004)
2) Market Trend of Fluorine Products, CMC Publishing CO., LTD. (2015)
3) Official websites of the Japanese Ministry of the Environment and Ministry of Economy, Trade and Industry
4) IPCC Fourth Assessment Report (2007), produced based on the official website of the Japan Fluorocarbon
Manufacturers Association: http://jfma.org/database/table.html
5) Ozone Layer Protection Promotion Office, Manufacturing Industries Bureau, Ministry of Economy, Trade and Industry.
Current State of Fluorocarbon Countermeasures (January 2020)
6) AGC, online product catalogs
7) Research Committee for the Risk Assessment of Mildly Flammable Refrigerants, The Japan Society of Refrigeratingand Air Conditioning Engineers. Final Report (August 2016)

ThreeBond Co., Ltd. R&D Headquarters
Development Division 3 Automotive Aftermarket Development Section
Toshifumi Kuboyama
Manabu Kirino

ThreeBond Co., Ltd.
8

4-3-3 Minamiosawa, Hachioji,
Tokyo 192-0398
Tel: +81-42-670-5333