Source for Naphtha sought

Tom James Braun <tom.braun [at] mnhs__org> writes

>Maya Dresner <dresner [at] tamuseum__com> writes
>
>>I am looking for suppliers of naphtha solvent. For many years I have
>>used BDH, but for some unknown reason it's not possible to trade
>>with them any more in Israel. Can you offer any suggestions for
>>alternative suppliers?
>
>... I
>think the name naphtha may have fallen out of use with some U.S.
>manufacturers. ...
>...
>Naphtha is an archaic name for what today is called petroleum
>benzine, but also formerly known as petroleum ether or benzine.  It
>is similar to what is commonly called VM&P Naphtha

In reply to the original posting about naphtha by Maya Dresner and
the response to it by Tom James Braun, I hope I might add the
following observations.   Over the course of the last year or so I
have been working (slowly and intermittently) on a textbook on the
use of organic solvents in conservation.  As it happens, I have
largely completed the chapter on hydrocarbon solvents. I have still
got quite a long way to go on the book, however, and it will
probably not appear for a while yet, I'm afraid.

One of the things I have tried to do in the 'Hydrocarbons' chapter
is explain and clarify all of the various names which are used for
generic hydrocarbon solvents; that is such terms as mineral spirits,
white spirits, petroleum spirits, petroleum ether, ligroin, Stoddard
Solvent, benzine, naphtha, and so on.  It has taken me a while, but
think I have managed to work my way through the maze of confusing
terminology.

Of the various types of generic hydrocarbon solvent mentioned above,
'naphtha' is perhaps the most ambiguous and poorly defined.  My own
view is that it is best to stay away from this term, unless one is
referring specifically to the product known in the USA as VM&P
Naptha (Varnish Makers' and Painters' Naphtha). The term 'naphtha'
is a term borrowed from the petrochemical industry and generally
refers to petroleum refinery streams prepared and treated in any
number of ways: it is not normally used as a term in isolation, but
usually with some form of descriptive qualifier.

By way of illustration, the following is a list of some 'naphtha'
type refinery streams which may provide the basis for either generic
or proprietary hydrocarbon solvents.  The source for this selective
list is a report by the European solvents industry lead body, the
HSPA Hydrocarbon Solvents Producers Association (HSPA).  Some
proprietary solvent products which correspond to these respective
refinery streams are also indicated in brackets.

    Naphtha (petroleum), heavy alkylate
        EU EINECS No.           265-067-2
        CAS Registry No.        64741-65-7
        Proprietary name        (Shellsol T)

    Naphtha (petroleum), hydrotreated light
        EU EINECS No.           265-151-9
        CAS Registry No.        64742-49-0
        Proprietary name        (Shell SBP 140/165)

    Naphtha (petroleum), hydrotreated heavy
        EU EINECS No.           265-150-3
        CAS Registry No.        64742-48-9
        Proprietary name        (Shellsol D60)

    naphtha (petroleum), solvent-refined light
        EU EINECS No.           265-086-6
        CAS Registry No.        64741-84-0

    solvent naphtha (petroleum) hydrotreated, light naphthenic
        EU EINECS No.           295-529-9
        CAS Registry No.        92062-15-2
        Proprietary name        (Exxon Mobil Nappar 6)

    solvent naphtha (petroleum), light aromatic
        EU EINECS No.           265-199-0
        CAS Registry No.        64742-95-6
        Proprietary name        (Shellsol A100)

    solvent naphtha (petroleum), heavy aromatic
        EU EINECS No.           265-198-5
        CAS Registry No.        64742-94-5
        Proprietary name        (Shellsol A150)

The main point to be taken from the above list is that 'naphtha'
might be used to describe solvents that contain zero, some, or all
aromatic hydrocarbon compounds.  It is important, therefore, to
distinguish between aromatic-free, aromatic-containing and
wholly-aromatic naphthas. The aromatic naphthas will have
appreciably higher solvent power, but also tend to present greater
health risk.

Even a term as apparently specific as VM&P Naphtha can actually
cover products which are quite varied in type.  In the United
States, VM&P naphthas are described in  ASTM 3735-02 'Standard
Specification for VM&P Naphthas' which covers four types of
moderately volatile hydrocarbon solvents, mainly aliphatic in
composition and normally petroleum distillates.  "VM&P Naphtha",
then, is generally understood to describe hydrocarbon solvents
similar to Mineral Spirits, but which are somewhat more volatile,
having boiling points mostly in the range 120-145 deg.C.

The four types of VM&P Naphtha described in ASTM 3735-02  are:

    Type I      -   Regular.
    Type II     -   High flash.
    Type III    -   Odorless.
    Type IV     -   Low aromatics

Applied to solvents, it would appear that the terms 'naphtha' and
'benzine' are essentially synonymous in North American usage.  For
example, a leading US laboratory chemicals supplier (Fisher
Scientific) offers a product 'Benzine (Petroleum Naphtha) which is
identified by the CAS Registry No. 64742-89-8 which defines the
product as Solvent naphtha (petroleum), light aliphatic.   This
product is effectively a low aromatics VM&P naphtha.

Because of the problems associated with nomenclature of, especially,
generic hydrocarbon solvents, my advice would be to look for your
solvents in terms of properties, as much as by name.  The key
properties of interest will probably be:

     boiling or distillation range
     evaporation rate
     aromatic content
     kauri-butanol no. or aniline point (indicators of solvent
        power/polarity)
     occupational exposure limits
     health hazard classification and risks.

I have compiled a list of the main manufacturers and suppliers of
hydrocarbon solvents worldwide and I may be able to point you in the
direction of a supplier of solvent to suit your needs. Feel free to
contact me directly, Maya.

Alan Phenix
Scientist, Museum Research Lab.
Getty Conservation Institute


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                  Conservation DistList Instance 20:35
                 Distributed: Monday, January 15, 2007
                       Message Id: cdl-20-35-001
                                  ***