Methyl-tris acetonoximo-silane

Auto flammability

Link to relevant study record(s)

Reference

Endpoint:

auto-ignition temperature (liquids)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-10-18 to 2017-11-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.15 (Auto-Ignition Temperature (Liquids and Gases))

Deviations:

no

Qualifier:

according to guideline

Guideline:

DIN 51794 (Testing of mineral oil hydrocarbons - Determination of ignition temperature)

Deviations:

no

Principles of method if other than guideline:

The test was performed according to SOP No. SPO/BC/06/b "Determination of auto-ignition temperature (liquids)" which is based on standard DIN 51794:2003-05 "Prüfung von Mineralölkohlenwasserstoffen - Bestimmung der Zündtemperatur". This test method corresponds to method A.15 Auto-ignition temperature (liquids and gases).

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Appearance: yellowish liquid
- Composition: 95.4 % MAC, 1.6 % MAC-Dimer, 2.9 % Acetone oxime
- Purity: 95.4 %
- Batch No.: 20160817
- Expiry date: 16.08.2018

Key result

Auto-ignition temperature:

380 °C

Atm. press.:

> 1 007 - < 1 018 hPa

Determination of the preliminary initial temperature for the main determination - T1:

The ignition chamber was heated with a rate between 3 - 5 °C/min. Five drops of liquid were introduced into the ignition chamber, during the increase of temperature at intervals of about 50 °C. After any attempt it was determined whether there was ignition at the time of 3 minutes. The preliminary initial temperature for the main determination (T1) is 400 °C.

Determination of the initial temperature for the main determination - T2 (at 21 °C, atmospheric pressure 1007 hPa):

The ignition chamber was heated up to the temperature about 100 °C below the predicted temperature of auto-ignition with the rate of 1.5 - 2.5 °C/min using a PID temperature regulator. Five drops of the test item were introduced into the ignition chamber and the temperature increased ín intervals of about 20 °C. During any such attempt it was determined whether there was ignition within 3 minutes. Before each introduction of a new portion of the sample the ignition chamber was cleaned using compressed air. The temperature at which the first ignition was observed was considered the initial temperature for the main test (T2). The results are shown in Table 1.

Table 1: Results of determination of initial temperature T2. + = yes, - = no. T2 = 400 °C (399 °C after including a thermometer deviation)

Temperature of oven [°C]	V [quantity of drops]	Result of test	Corresponding delay time [s]
300	5	-	-
320	5	-	-
340	5	-	-
360	5	-	-
380	5	-	-
400	5	+	8

The lowest value from the first series (stage I - T3, stage II - T4):

Stage I - T3:

The test started with a temperature 5 °C lower than the initial temperature for the main determination (T2). Five drops of liquid were introduced into the ignition chamber and it was determined whether there was ignition within 3 minutes. After each positive test the temperature of the ignition chamber was decreased by 5 °C until it reached the exact temperature at which for the first time no ignition was observed. Then tests of ignition were performed at this temperature by increasing each time the amount of sample used by 1 drop. Before each introduction of a new portion of sample the ignition chamber was cleaned using compressed air. In this way the temperature was reached at which no ignition occurred irrespective of the quantity of sample introduced. The result of determination in stage I is the temperature (T3). It is the lowest temperature for which a positive result was obtained. The results are shown in Table 2.

Table 2: Results of determination of lowest temperature for the first series T3. + = yes, - = no. T3 = 390 °C (389 °C after including a thermometer deviation)

Temperature of oven [°C]	V [quantity of drops]	Result of test	Corresponding delay time [s]
395	5	+	10
390	5	-	-
390	6	+	20
385	6	-	-
385	7	-	-
385	8	-	-
385	9	-	-
385	10	-	-

Stage II - T4:

The test started with a temperature 2 °C lower than the temperature T3. Test were carried out in the same way as in stage I, changing temperatures and the quantity of the sample. Then tests of ignition were performed at this temperature by increasing each time the amount of sample by 1 drop. Before each introduction of a new portion of the sample the ignition chamber was cleaned using compressed air. The lowest temperature at which the proceeding in the manner indicated above still led to ignition was considered the lowest value of the first series of tests (T4). The results are shown in Table 3.

Table 3: Results of determination of lowest temperature for the first series T4. + = yes, - = no. T4 = 391 °C (390 °C after including a thermometer deviation)

Temperature of oven [°C]	V [quantity of drops]	Result of test	Corresponding delay time [s]
388	5	-	-
388	6	-	-
388	7	-	-
388	8	-	-
388	9	-	-
388	10	-	-
393	10	+	18
391	10	+	24
389	10	-	-

The lowest (final) value from the main determination (stage III - T5) at 22 °C and 1018 hPa:

The lowest value of the first series of tests (T4 ) was affected by contamination remaining in the ignition chamber after its repeated use and therefore it cannot be treated as the final result. The range close to the lowest temperature value from the first series of tests (T4) contained the final result of the main determination. In order to find the "lowest (final) value of the temperature from the main determination" (T5) a new and clean ignition chamber was used.

The test started with a temperature 5 °C higher than the temperature T4. At this temperature the tests of ignition were performed by increasing each time the amount of sample by 1 drop. If no auto-ignition had occurred, the tests of ignition were repeated by further increasing the temperature of the ignition chamber by 5 °C. After auto-ignition occurred, the tests of ignition were repeated by further lowering the temperature of the ignition chamber by 2 °C. In this way the temperature was reached at which auto-ignition did not occur irrespective of the quantity of sample introduced. Before each introduction of a new portion of sample the ignition chamber was cleaned using compressed air. Table 4 shows the results.

Table 4: Results of determination of the final temperature T5. + = yes, - = no. T5 = 388 °C (387 °C after including a thermometer deviation)

Temperature of oven [°C]	V [quantity of drops]	Result of test	Corresponding delay time [s]
396	5	+	4
394	5	+	5
392	5	-	-
392	6	+	14
390	6	+	15
388	6	-	-
388	7	+	20
386	7	-	-
386	8	-	-
386	9	-	-
386	10	-	-

Repeating of determination - T6 (22 °C, 1016 hPa):

Using the lowest temperature range (final) values from the main determination (T5) the operations were repeated (in a series of measurements using a new ignition chamber) until the required condition was met. For the auto-ignition temperatures above 300 °C three lowest values from the main determination and repeated determination did not differ from each other more than 20 °C. The results are shown in Table 5.

Table 5: Results of repeating of determination T6. + = yes, - = no. T6 = 382 °C (381 °C after including a thermometer deviation)

Temperature of oven [°C]	V [quantity of drops]	Result of test	Corresponding delay time [s]
396	5	+	1
394	5	+	3
392	5	+	4
390	5	+	4
388	5	+	6
386	5	-	-
386	6	+	9
384	6	+	9
382	6	-	-
382	7	+	11
380	7	-	-
380	8	-	-
380	9	-	-
380	10	-	-

Summary of results:

Table 6 summarizes the results of the test.

Table 6: Results of determination of auto-ignition temperature (atmospheric pressure 1007 -1018 hPa)

Stage of determination	Auto-ignition temperature [°C]	V [quantity of drops]	Corresponding delay time [s]
Ignition temperature positon for main determination (T2)	399	5	8
The lowest value from first series of tests (T4)	390	10	24
The lowest value from main determination (T5)	387	7	20
The lowest value from first repeating (T6)	381	7	11
The lowest experimental value of ignition temperature	381	7	11
Auto-ignition temperature according to DIN 51794:2003 -05	380	-	-

Conclusions:

The auto-ignition temperature of methyl-tris acetonoximo-silane (MAC) is 380 °C.

Executive summary:

The auto-ignition temperature of methyl-tris acetonoximo-silane (MAC), which was determined according to a method corresponding to EU method A.15, is 380 °C.

Description of key information

The auto-ignition temperature of methyl-tris acetonoximo-silane (MAC), which was determined according to a method corresponding to EU method A.15, is 380 °C.

Key value for chemical safety assessment

Autoflammability / Self-ignition temperature at 101 325 Pa:

380 °C