Phosphorus VolatilityChevron Oronite Perspective

February 2007

Phosphorus Volatility

• Desired outcome: Identify an effective bench test method to measure P-Vol

• We believe that PEI165 represents best available option– We have worked with Savant to evaluate PEI165

more fully– PEI 165 correlates with both field and IIIG data– PEI165 also ranks ZDP in line with chemical

composition relating to volatility– Discrimination power greater than IIIG

• ROBO should continue evaluation as alternative

PEI165: Thermal Stability

Study of PEI Values of Primary and Secondary ZDDPsAt 250° and 165°C

13.6

3.5

5.9

13.2

0.0

5.0

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15.0

250°C 165°CTemperature

PE

I T, m

g/L

Primary ZDDPSecondary ZDDP

• PEI165 correctly ranked primary vs. secondary ZDP (thermal stability and volatility)

Courtesy: Savant

PEI165: ZDP Volatility

• Created model ZDP compounds to generate controlled volatility

• PEI165 correctly ranked against ZDP volatility

Less volatile

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Increasing C Number in ZDPP

EI1

65

, m

g/L

repeats

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0 5 10 15

P Deposit in field test, g

PE

I16

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alu

e, m

g/L

PEI165: Field test correlation

• Ranked corrected against Ford field test reference oils

Courtesy: Savant

PEI 165 vs. IIIG

y = -0.2814x + 98.5

R2 = 0.9597

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100

0 50 100 150

PEI165, mg/L

P R

ete

nti

on

, %

Ford field test

TMC 435

TMC 434

Hypothetical point

Using the trend line above:IIIG 84.4% = 50.1 mg/L PEI165IIIG 82% = 58.6 mg/L PEI165

PEI165: repeatability

PEI165 Summary• Provides correct correlation with ZDP type,

ZDP molecular weight, Ford field test and IIIG

• Provides better separation than IIIG (~10% in IIIG vs. ~50 mg in PEI165)

• Provides better test repeatability• Preserves IIIG parts• Cost effective versus IIIG

Assuming no change in P chemical limit, Oronite supports PEI165 with appropriate P/F limit

ROBO for P Retention• ROBO P retention correlates with IIIG

reference oils (courtesy: Rohmax and GM)

– TMC 434 80.3%– TMC 435 88.8%– TMC 438 81.%

• Provides an 8.5% separation between 434 and 435

ROBO for P Retention• ROBO repeatability is a concern

– Two repeats (B) differ by 10%– A third (A) is different only in base stock

• Will require more study or development

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A B B

RO

BO

P R

eten

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