Dasar Dasar Additive Pelumas

11/06 JobbersChevronPhaseI LubAdd RFarina

© 2006 Chevron Corporation Global LubricantsCopyright 2006 Chevron Global Lubricants, a division of Chevron U.S.A. Inc.All rights reserved. Unauthorized reproduction is prohibited.

The Basics of Lubricant Additivesor

It’s Not Just Oil!

March 2009



G010075

ViscosityIndex

Improvers

Dispersants

Rust andCorrosionInhibitor

FoamInhibitors

AntiwearAgents

Anti-Oxidants

Detergents

Pour PointDepressants

FrictionModifiers

Group II

BaseStock

It’s Not Just Oil!



Base Oil70-95%

Pour Point Depressant0-2%

Viscosity Modifier0-15%

DIPackage2-30%

Typical Lubricant Composition



Formulating a Superior Lubricant Requires Optimizing Additive Combinations to Meet Performance Targets

Viscosity

Engine Cleanliness

Wear Control

Fuel Economy

Drain Interval

Cost



Graphic Representation of anAdditive Molecule

Sticky End

Consists of a Surface Active Group Containing Oxygen, Nitrogen, Sulfur, or Phosphorus

Sticky End Slippery Tail

G010077

Slippery Tail

Consists of a Hydrocarbon Chain



Ashless Dispersants



Ashless Dispersants

Function • Control Sludge and Varnish Formation at Lower Operating Temperatures

• Control Thickening Caused by Soot

Structure • High Molecular Weight Tail With Surface Active Head

Mechanism • Keep Sludge, Soot, and Deposit Precursors Suspended in Oil



G010078

(Dispersant)

(Solid Particles)

Rate ofAggregation Slowed

Dispersants Impede Particle Aggregation



Dispersant Selection

Must Balance Performance Attributes

Need to Control Soot Thickening, Sludge

Too Much May Hurt Seal Performance

(More is Not Always Better!)



Metallic Detergents



Function • Provide High Temperature Cleanliness

• Control Corrosive Wear

Types • Metallic Soaps; Normally Na, Ca, or Mg

• “Soap” Substrates - Sulfonates - Salicylates - Phenates

Mechanism • Neutralize Acids From Engine Blow-By

Metallic Detergents



G010079

CaCO3CaCO3CaCO3

CaCO3CaCO3

CaCO3

CaCO3

CaCO3

CaCO3CaCO3

CaCO3CaCO3

CaCO3

CaCO3

Soap MoleculeBasic

Core

Overbased Detergent



Detergency in Oils

Gum Being Polar, Sticks on Polar Surfaces

The Polar Ends of Detergents Also Stick to Polar Surface

An Effective Detergent Displaces Gum (Deposits)

G010080



Detergent Selection

Balance Cost and Performance Requirements

Too Much May Hurt Wear Performance

May Use Multiple Types of Detergent

Phenates for Higher Temperatures

Sulfonates for Lower Temperatures



100

9080

70

6050

40

30

20

100

109876543210

Sulfated Ash, %

To

tal B

ase

Nu

mb

er

(TB

N)

AS

TM

D 2

89

6 m

g K

OH

/g

Marine Oil

Marine OilRailroad Oil

HDMO

PCMO

Relationship of TBN and Ash



Antioxidants



Function • Control Oxidative Decomposition of Oil • Minimize Oil Thickening • Decrease Sludge and Varnish Formation • Decrease Formation of Corrosive

Compounds (Acids)

Types • Organic – Phenols, Amines • Metal-Containing – Zinc Dithiophosphates

(ZDP), Molybdenum Compounds

Mechanism • Decrease Rates of Chemical Reactions With Oxygen

Antioxidant Formulation



Factors Affecting Oxidation

Temperature

Catalysts (Metal Ions)

Aeration Rate

Additive System

Base Stock



Antioxidant Selection

Most Performance Comes From the Antiwear Additive (ZDP)

Supplement to Meet Sequence IIIE

Compatibility With Seals

Cost

May Use Multiple Antioxidants



Antiwear Agents



Function • Reduce Wear of Rubbing Metal Surfaces

Types • Amine or Metal Phosphites, Phosphates, or Thiophosphates (ZDP)

• Boron Compounds • Sulfurized Olefins

Mechanism • Adhere to Metal Surfaces, Forming a Protective Film Which Shears Preferentially Under Wear Conditions

Antiwear Agent



G010081

ZDPZDP

ZDPZDP

ZDPZDP ZDP

ZDP

Metal Surface

Adsorbed ZDP Layer

Metal Surface

Bulk Oil

Metal Surface

Phosphorous Containing Antiwear Film

HEA

T

Formation of a Zinc Dithiophosphate (ZDP) Antiwear Film

HEA

T



Friction Modifiers



Friction Modifiers

Function • Reduce Friction of Rubbing Metal Surfaces

Types • Fatty Compounds With Polar Ends • Graphite • Molybdenum Compounds

Mechanism • Forms an Easily Shearable Film on Metal Surface



Metal

Oxide/Metal ZoneOxide Rich Layer

Adsorbed Film of F.M.(Three Stories High)

Oil Film

Metal

Oxide Rich Layer Oxide/Metal Zone

Adsorbed Film of F.M.(Five Stories High)

G010082

Lubricated Metal Surfaces With Friction Modifier Present



Friction Modifier Film(Five Levels Remaining)

Oxide Layer

Moving Asperity

G010083

Asperity Riding onFriction Modifier Layer



Function • Prevent Oil Loss or Oil Starvation Caused by Foaming

• Reduce Oil Aeration

Types • Polydimethyl Siloxanes • Polyacrylates

Mechanism • Reduce Surface Tension of Oil Causing Bubbles to Collapse

Antifoam Agent



Viscosity Modifiers



Vis

cosi

ty

Temperature

Viscosity Modifier (VM’s) Viscosity Index Improvers (VII’s)

Base Oil + Viscosity Modifier(High VI)

Viscosity Modifiers Are Materials (Usually Polymers)Which Improve (i.e., Increase) the VI of a Base Oil

Viscosity Modifiers on Temperature Dependence of Viscosity

SAE 10W MaxSAE 10W Max

SAE 30 MinSAE 30 Min

SN 250SN 250

SN 100SN 100



G010075

PolymerMolecule

Oil AssociatedWith Polymer

Increasing Temperature

Increasing Viscosity Contribution

(Increasing Effective Size of Polymer)

Viscosity Modifier Mechanism



Pour Point Depressants



Pour Point Depressants

Function • Reduce Viscosity Increase at Low Temperatures Resulting From Wax Crystallization

• Improve Low Temperature Pumpability

Structure • Organic Polymer

Mechanism • Promote Formation of Smaller, Rounded Particles Which Are Less Likely to Form Interlocking Crystals



Pour Point DepressantsWax Crystal Morphology

Without PPD With PPD

G010084



Other Additives(See Supplemental Materials)

Corrosion Inhibitors

Demulsifiers

Emulsifiers

EP (Extreme Pressure) Agents

Metal Deactivators

Rust Inhibitors



Some Key Points to Remember

Additives Are Carefully Balanced to Enable Base Oils to Meet Defined Performance Criteria

More is Not Necessarily Better

Additive Interactions Are Strong

Developing a Successful Formulation Requires Extensive Testing and Verification

Chevron Experience and Commitment to Technical Excellence is Key



Supplemental Information

The Basics of Lubricant Additives



Vis

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Imp

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Dete

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Dis

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Dem

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Engine Oils Crankcase Engine Oil Automatic Transmission Fluid Rear Axle Lubricants Manual Transmission Lubricants Power Steering Fluid Body/Chassis Greases Shock Absorber Fluid Pre-Lubricants Industrial Oils Turbine and Other R&O Fluids Antiwear Hydraulic Fluids Fire Resistant Hydraulic Fluids Metalworking Lubricants Industrial Gear Oils Plant Machinery Greases Paper Machine Oils Soluble Oils

Often Used

Occasionally Used

Where Additives Are Used



Additive What It Does How It Works

Antiwear Agent

• Minimizes wear caused by metal-to-metal contact during conditions of mild boundary lubrication.

• Additive reacts chemically and forms a film on metal surfaces under normal operating conditions.

Antioxidant or Oxidation Inhibitor

• Inhibits varnish and sludge formation.

• Reduces viscosity increase resulting from oil oxidation.

• Reduces formation of corrosive acids.

• Slows the rate of reaction with oxygen by interruption of chain reactions or by decomposing reactive peroxides.

Demulsifier • Loosens and breaks stable emulsions. • Lowers emulsion stability.

Corrosion Inhibitor

• Prevents corrosive attack on nonferrous metallic surfaces.

• Forms a film on nonferrous metallic parts thus protecting them from attack by contaminants in the oil.

Detergent • Prevents oxidation products (gums) which have formed in the oil from sticking to metal parts.

• Neutralizes acidic contaminants.

• Chemically react with oxidation products (gums) so that they remain soluble in the oil and do not stick to metal surfaces.

• Metallic Base Reacts With Acid

Dispersant • Keeps oxidation products separated and suspended in the oil, retards formation of sludge and reduces soot related viscosity increase.

• Additive adsorbs on surface of gum particles or soot and inhibits agglomeration.

Additives Commonly Foundin Lubricants



Additive What It Does How It Works

Extreme Pressure (EP) Agents

• Prevents welding and subsequent wear or seizure of contacting metal parts under extreme or shock load conditions.

• Additive combines chemically with surface to form a surface film.

• Reaction usually occurs at high temperatures, which result when asperities collide.

Emulsifier • Promotes rapid mixing of oil and water promoting formation of a stable emulsion.

• Reduces interfacial tension and permits intimate mixing of oil and water.

Foam Inhibitor • Prevents formation of stable foam. • Promotes combination of small bubbles into large bubbles, which in turn collapse more easily.

Friction Modifier • Alters coefficient of friction. • Forms an easily shearable film on metal surfaces.

Metal Deactivator • Reduces the catalytic effect of metals on oxidation rate.

• Forms an inactive film on metal surfaces by combining with metallic ions.

Rust Inhibitor • Prevent rusting of ferrous (iron or steel) machine parts.

• Forms a film on ferrous parts thus protecting them from water or other destructive materials.

Pour Point Depressant

• Lowers the pour point and enables the lubricant to flow at low temperature.

• Changes the size and shape wax crystals.

Viscosity Modifier (VM) or Viscosity Index Improver (VII)

• Reduces rate of change of viscosity with temperature and makes possible the formulation of multigrade oils.

• Polymers uncoil as temperature rises, thus increasing their effective size and viscosity.

Additives Commonly Found in Lubricants(Continued)

Dasar Dasar Additive Pelumas

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