Improvements in the Manufacture of a Drying Medium for Paints, and of Oil Varnish.
Year: 1893

page_text: Date of Application, 19th Sept., 1893
Complete Specification Left, 16th June, 1894-Accepted, 21st July, 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of a Drying Medium for Paints,
and of Oil Varnish.
We, JAMES EDWARD BEDFORD of Cardigan Road in the City of Leeds and
CHARLES SAMUEL BEDFORD of Broomleigh Headingley in the City of Leeds
Chemists do hereby declare the nature of this invention to be as follows:-
This invention has for its object an improvement in the manufacture of a drying
medium for paints & of oil varnish which consists first in decomposing linseed oil
by the well known method of saponification into its respective oil acids and
glycerin.
The seperated oil acids are then submitted to the action of air or oxygen gas
preferably at a slightly increased temperature:-50° C. in an apparatus such as is
described in the Specification No. 18628, 1889 of L. T. Thorne & Brins Oxygen
Company Ld. or in any other suitable form of apparatus which brings a large
surface of the oil acids into contact with the air or gas to be absorbed. In this
manner the oil acids take up oxygen especially in presence of a small quantity of a
drier such as litharge whilst the iodine absorbtion is found to sink rapidly & the
oil acids at last assume a honey like or semi solid consistency. At this stage they
are almost insoluble in turpentine and petroleum spirit but mix readily with
ordinary oxidized or boiled linseed oil and may be used in conjunction with
them.
For the preperation of a quick drying medium or varnish for use in the
manufacture of oil cloth we take oxidized oil acids from Baltic linseed oil, not too
far oxidized as to render them or their soap insoluble in the solvents used & add
say 10% of turpentine or petroleum spirit.
The mixture is heated to 70° C. and 5 to 15% of a moist crystalline hydrate of
one of the alkali metals barium calcium strontium or magnesium is added stirring
vigorously till the soap formed has dissolved. Lead or manganese driers may also
be used.
The medium thus produced possesses quick-drying properties & when spread
upon oil cloth either as a varnish or in conjunction with pigments & placed in the
drying stove heated to 140°-160° F. will dry without tackiness in twelve
hours.
Dated this 18th day of September 1893.
JAMES E. BEDFORD.
CHAS. S. BEDFORD.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of a Drying Medium for Paints,
and of Oil Varnish.
We JAMES EDWARD BEDFORD of Cardigan Road in the City of Leeds and
CHARLES SAMUEL BEDFORD of Broomleigh Headingley in the City of Leeds
Chemists do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
This invention has for its object an improvement in the manufacture of a drying
medium for paints & of oil varnish which consists first in decomposing linseed oil

page_text: by the well known method of sa pouification into its respective oil acids and
glycerin.
The seperated oil acids are then submitted to the action of air or oxygen
preferably at a slightly elevated temperature:-50° C. in an apparatus such as is
described in the Specification No. 18628, 1889 of L. T. Thorne and Brin's Oxygen
Co. Ld. or in any other suitable form of apparatus which brings a large surface of
the oil acids into contact with the air or gas to be absorbed.
In this manner the oil acids take up oxygen especially in presence of a small
quantity of a dryer such as litharge whilst the iodine absorbtion is found to sink
rapidly & the oil acids at last assume a honey like or semi solid consistency.
At this stage they are almost insoluble in turpentine & petroleuni spirit
but mix readily with ordinary oxidized or boiled linseed oil & may be used in
conjunction with them.
Example 1. For the preperation of a quick drying medium for use in the
manufacture of oil cloth we take oxidized oil acids from Baltic linseed oil not too
far oxidized as to render them or their soap insoluble in the solvents used & add
say 10% of turpentine or petroleum spirit."
The mixture is heated to 70° C. and 5 to 15% of a moist crystalline hydrate
of one of the alkali metals :-Barium calcium strontium or magnesium is added
stirring vigorously till the soap formed has dissolved. Lead or manganese dryers
may also be used.
The medium thus produced possesses quick drying properties & when spread
upon oil cloth as a varnish or in conjunction with pigments & placed in the
drying stove heated to 140°-160° F. will dry without tackiness in twelve hours.
The term
"oil acids" is here used specifically to denote a linseed oil which has
been submitted to partial or complete saponification & is capable of directly
neutralizing an appreciable amount of NaOH. Linseed oil requires 13.66% of
NaOH for complete saponification.
In order to test the neutralizing power of the oil acids we weigh out about
2 grams of the sample & agitate it in a stoppered bottle with 25 C.C. standard soda
solution & 20 C.C. alcohol running in standard H₂SO, till the indicator phenol
phthalein shows the solution to be neutral. From the amount of standard H.SO.
required the NaOH absorbed by the oil acids is ascertained.
Example 2. In order to prepare a thinner varnish we take oil acids capable of
absorbing 5 to 9% NaOH made by boiling linseed with 5 to 7 % fine slaked lime
acidifying the soap formed & washing the resulting oil acids with water to remove
all traces of the acid employed. We then oxidize the oil acids in the manner
above described taking care that the temperature does not rise above 70° C. till
the required honey-like consistency is obtained. We then cool & add 50% of
turpentine, light petroleum or benzene or a mixture of any of them along with
3 to 7% of calcined magnesia & when the whole is incorporated the varnish is
ready for use. These varnishes & paint mediums have the property of drying
with a glassy surface free from shrivelling which is a great defect with oils
prepared in the usual manner.
Having now particularly described & ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The manufacture of quick drying varnishes & paint mediums from linseed
oil by first submitting the linseed oil to the process of saponification either
complete or partial eliminating the "oil acids" produced by acidifying the soap
formed with a mineral acid washing the "oil acids" with water to remove all
traces of the mineral acid employed & oxidizing the "oil acids" produced either
alone or with dryers by means of air or oxygen in any suitable apparatus in which
a large surface of the "oil acids" is brought into intimate contact with the air or
oxygen to be absorbed and incorporating the thickened "oil acids" with a suitable
quantity of solvent & with the necessary amount of a hydrate or oxide of one or

page_text: more of the alkali metals-barium calcium strontium or magnesium or with dryers.
like lead & manganese.
2. The employment in the manufacture of varnishes & paint mediums of
linseed oil from which the whole or part of the glycerin has been removed by
saponification or hydrolysis with subsequent oxidation by means of air or
oxygen.
Dated this 15th dor of Lune 1901
JAMES E. BEDFORD.
CHAS. S. BEDFORD.