Detergents: Magnesium vs Calcium

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Originally Posted by RDY4WAR
Great information. That's the kind of info I was hoping to get when I started this thread.

What boron additives are added for mild detergency? If calcium is from CaCO3 and magnesium from MgCO3, what about boron? If you were still formulating today, would you include a hefty dose of boron?



I'm not a big believer in Boron in engine oil.

I suspect 99% of the Boron you see in engine oils comes from Boric Acid capped Ashless Dispersants. The Boric Acid improves the seal compatibility of the ashless dispersant (by zapping some of the active nitrogen sites) but ironically this makes it a worse dispersant! The Boron is there as a necessary evil rather than something that makes for a great oil in its own right.

Things may have changed since my day, and I'm happy to be corrected but IMO, a hefty slug of Boron is something to be avoided.
 
I had a very quick look at what Boron compounds were appearing in the recent patent literature. This popped up in a Chevron (Oronite) patent to do with improved wear...

'400 ppm, in terms of boron content, of a combination of a borated dispersant (5.2 wt. % in the finished oil), and a borated calcium sulfonate (3 mmol/kg Ca basis in the finished oil) having a TBN of 160'

If I'm interpreting this correctly, the Boron in 'the invention' derives from Ashless Dispersant & Overbased Calcium Sulphonate, both of which have been post-reacted with Boric Acid (that's what borated means). There is little new here and it's not a million miles from what I said.

In my experience, it's really not wise to invest faith in oil companies having great wisdom regarding engine oils. They really don't know that much and much of what they think they know, is wrong.
 
Originally Posted by SonofJoe
I had a very quick look at what Boron compounds were appearing in the recent patent literature. This popped up in a Chevron (Oronite) patent to do with improved wear...

'400 ppm, in terms of boron content, of a combination of a borated dispersant (5.2 wt. % in the finished oil), and a borated calcium sulfonate (3 mmol/kg Ca basis in the finished oil) having a TBN of 160'

If I'm interpreting this correctly, the Boron in 'the invention' derives from Ashless Dispersant & Overbased Calcium Sulphonate, both of which have been post-reacted with Boric Acid (that's what borated means). There is little new here and it's not a million miles from what I said.

In my experience, it's really not wise to invest faith in oil companies having great wisdom regarding engine oils. They really don't know that much and much of what they think they know, is wrong.



I think I'll stick with MolaKule and his advice thank you very much
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QSGB doesn't have over 400ppm FYI either

If Boron was IN FACT BAD I seriously doubt any oil company would use it. Above quote by YOU is YOUR OWN opinion
 
I have read here in mg is abrasive as compared to calcium so I think all Mobil 1 has high iron ppm in VOA.
 
SonicofJoe was an oil formulator and his opinions should be valued much more than that. You took it to the level of downright rudeness. I too have read patents saying that borating dispersants is to make them more seal-friendly. There are other boron-based additives besides dispersants and detergents but it's generally not possible to know the chemical form.

See that TBN of 160? That's for the additive mixture, not the finished oil, so the boron concentration in finished oil goes down by the fraction of the mixture relative to the whole.
 
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HDEOs have to have a lot of dispersants for soot-handling and dispersants are hard on seals. Various seal tests have to be passed, so borating dispersants helps with that.
 
Originally Posted by JAG
HDEOs have to have a lot of dispersants for soot-handling and dispersants are hard on seals. Various seal tests have to be passed, so borating dispersants helps with that.



So that explains why DELO has like 300ppm

Thanks JAG as I always learn something from you
smile.gif
 
Originally Posted by 53' Stude
Originally Posted by JAG
HDEOs have to have a lot of dispersants for soot-handling and dispersants are hard on seals. Various seal tests have to be passed, so borating dispersants helps with that.



So that explains why DELO has like 300ppm

Thanks JAG as I always learn something from you
smile.gif




Yeah I agree Strude53.. JAG is tremendous on here.
 
A couple more comments on Boron relating to their linkage with ashless dispersants (ADs)...

When you're formulating an oil, you usually have a selection of ADs in your armoury to play with; high & low TBN, high & low molecular weight, cheap & expensive and seal friendly or unfriendly. Your job as an oil formulator is to figure out which single AD, or combination of ADs, fits what you're trying to do both for the specific technical job at hand and the greater strategic scheme of things.

As a very bare minimum, you might have just two ADs that you need to 'balance out'. The first might be a highly potent, cheap, high TBN AD that's great for all manner of things (sludge, cleanliness, etc). However these ADs are usually very aggressive to Nitrile seals causing them to crack. Your second AD might simply be the first AD that has been post-reactively 'capped'. This typically will make it less potent (so you need to add more), lower its TBN & make it more expensive. However the net pay-off is better seal compatibility.

You can cap an AD in several ways. One of the oldest ways is simply to react it with a bit of Boric Acid. There are no hard & fast rules as to how much you add but the idea is you add it 'just to take the edge off', so that you just zap the most aggressive nitrogen sites. If you use a borated AD, you automatically see Boron showing up in oil. However remember that you may very likely use a COMBINATION of capped & uncapped so the level of Boron you end up with will bounce around depending on which AddCo has formulated the oil.

But you don't have to use Boric Acid to cap as any organic acid does the same job. Glycolic Acid can be used to cap an AD. It's more expensive than Boric Acid but has the advantage that it 'invisible' (ie it doesn't show up on ICP). This can be a boon in constructing linked, globalised formulation hierarchies. Likewise, you can cap with Poly Iso-Butylene Succinic Anhydride (PIBSA), the acidic chemical intermediate used in the production of most ADs. This too is 'invisible' and means you don't have to buy in & store a separate capping agent. Personally I don't like PIBSA capping because it can be abused by formulators to give a highly misleading impression of how an oil will perform in the field.

So, in short, Boron derived from boronated ADs (and Detergents) is not inherently bad. It's usually there to get through seal tests and that's it. However it's not without it's downsides. All capping makes for a less efficient, more costly AD & you will need more of it to achieve a given target. More AD in any oil brings it's own set of issues of which higher Noack is probably the biggest.

To the person that asked about HDDO's all of the above applies but with a couple of caveats. HDDOs do tend to contain more AD than PCMOs for soot handing. However HDDO seal test requirements are often less severe than their PCMO equivalents (VW's PCMO tests were far harder to pass than MB's HDDO ones). Also HDDOs tend to make far greater use of Dispersant VIIs which tend to be far less aggressive to seals than conventional ADs.

Finally, on a different topic, I wouldn't say Mg Sulphonate is anymore abrasive than Ca Sulphonate. If there is an issue with detergent abrasiveness, it's probably due to some suppliers not filtering their products properly, leaving them noticeably hazy when ideally they should be clear & bright.
 
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SoJ,
I recall back in the day, and from a consumer's perspective, rather than a formulators, that the Mg "Ash" was supposed to be more abrasive than the Ca "Ash", being described as harder, more angular, less friable.

Just saying, that's what was out there in the consumer rags.

You weren't here for the heyday, but at one stage, boric acid engine oil additives were the rage....
 
Thanks, SonofJoe. I learned new things from that post. Seals are a big deal to me. I got rid of my 2003 VW GTI at 200k miles because it was leaking almost every fluid that it had in it and fixing it was too costly.
 
I am going to take a shot at posting again after giving it a break following several frustrating boots off BITOG accompanied by a loss of my typing not long after the big switch...

I can't track it down at this point, but wemay posted a link a while ago to a study that claimed that at least one magnesium-based oil additive interfered with the synergistic relationship between MoS2 and ZDDP in protecting metal surfaces in engines.
It was also found that a boron-based additive (dispersant??) could be used to limit this interference and restore the desired MoS2-ZDDP synergy.

I am hoping that wemay might notice this post and help me find his original post, it was a good one and I am bummed that I didn't save it as a favorite!

Anyway, I am wondering if this might be related to the notion of the magnesium-based detergents being abrasive...not that they cause damage in and of themselves, but that they interfere with another process that limits damage.
wemay's post caused me a bit of worry as a driver who is concerned about LSPI in his DIT engine and was very relieved when d1G2 went live, as formulations that meet that standard have generally had a good dose of magnesium...I have noted that they have also shown some boron, as well.
 
Originally Posted by Shannow
SoJ,
I recall back in the day, and from a consumer's perspective, rather than a formulators, that the Mg "Ash" was supposed to be more abrasive than the Ca "Ash", being described as harder, more angular, less friable.

Just saying, that's what was out there in the consumer rags.

You weren't here for the heyday, but at one stage, boric acid engine oil additives were the rage....



I've never looked closely at this 'ash abrasiveness' thing before but after a bit of Googling, here's what I think...

Any oil you buy already contains what might be described as 'ash'. The oil will contain just under 1% calcium carbonate (chalk) or magnesium carbonate (magnesite) in their mineral form. You won't be able to 'see' it because it will exist as tiny particles, colloidally held in suspension with organic detergent. These particles aren't abrasive because the only thing metal surfaces see of them are the long alkyl tails that surround each particle; not the mineral salt itself.

Now imagine those alkyl tails didn't exist and you just had pure chalk or magnesite in the oil, in your engine. Both are relatively soft minerals (compared to carborundum say). However magnesite, with a moh hardness of 4 (ish) is harder than chalk with a moh hardness of 3. On these numbers, it could well be right that Mg ash is more abrasive than Ca ash.

Okay, so how, on an engine, do you go from harmless colloidally suspended magnesium carbonate to this potentially abrasive Mg ash? Burning it might work! But here's the thing. I've put so many full Mg-based oils through the Sequence IIIF/IIIG tests with zero abrasion problems. This 150C test is a notorious 'oil eater' which will happily burn 75% of the oil in the sump if you're not careful, so where's this abrasive Mg-ash? My experience is that it's just not there!

(BTW, the same applies to load of other industry standard tests I ran on full Mg systems).
 
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Concerns with wear at low temperatures, due to the required higher activation temperatures of ZDDP and MoDTC, led to a search for a compound for wear reduction at those lower temperatures and boron compounds were found to mitigate that situation.

The most common form of Boron in engine lubricants today is a nano-particle version of Boric acid or specifically, Orthoboric acid (3H2O-B2O3) carried in an ester base.

Chemically, boric acid is a very very mild, non-toxic acid and the nano-particles form a soft laminar layer that reduces friction and wear.

According to Erdemir and other Tribology researchers, 1) Orthoboric acid compounds can reduce the friction coefficient and form a Tribofilm in Boundary and Mixed lubrication conditions, 2) a reduction in the friction coefficient, especially at low speeds, low temperatures, and high loads was observed in both bench and engine tests.

In ATF, phosphorilated boron compounds are Multi-functional compounds in the PI package that provides both a reduction in wear and modify the dynamic friction coefficients in wet clutch systems.


So i am more optimistic about the efficacy of Boron compounds in lubricants.
 
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Thanks to everyone contributing to this thread. I'm learning a lot and taking all opinions and experience in drawing my own conclusions. Keep it coming.
 
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