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The present invention relates to novel alkyd resins, to their preparation and to compositions containing them. An alkyd resin may be generally considered as the polyester condensation product of a polyhydric alcohol and a polybasic acid, the polyester usually being chain-terminated by means of a monobasic acid. Compositions containing alkyd resins are widely used in the surface coating industry in which an alkyd resin containing olefinic unsaturation in solution in a solvent, suitably a hydrocarbon solvent, is blended in the cold with other resin or polymer solutions to give a clear finish or is used as the vehicle for pigment grinding to form ultimately a coloured surface coating which oxidises in the presence of air to a hard film.
The components of the alkyd resin obviously exert an effect on its properties. For example, if the monobasic acid is unsaturated a "drying alkyd" is obtained in which chemical reaction takes place in the surface coating after application. If the monobasic acid is substantially saturated then a "non-drying alkyd" is obtained. In a similar manner the structure of the polybasic acid also influences the properties of the alkyd resin and it is to this part of the alkyd molecule that the present invention is directed.
According to the invention, therefore, a novel alkyd resin comprises the condensation product of a polybasic acid and polyhydric alcohol in which part at least of the polybasic acid is the reaction product of an olefinically unsaturated hydrocarbon resin with an alpha-beta olefinically unsaturated monobasic acid, dibasic acid or derivative thereof.
The hydrocarbon resin is suitably derived from a petroleum feedstock and, in particular, from a pyrolysis gasoline. Pyrolysis gasoline is a fraction obtained when a hydrocarbon feedstock is cracked by heating, optionally in the presence of steam, and subsequently distilled. Notable constituents of the pyrolysis gasoline include isoprene, piperylene, cyclopentadiene, pentanes, pentenes, hexanes, hexenes, cyclohexane and methylcyclohexane.
The unsaturated components of the pyrolysis gasoline are amenable to polymerization which may be catalysed by a Friedel Crafts catalyst such as aluminium chloride. This resin still contains residual olefinic unsaturation and can be further reacted with an alpha-beta olefinically unsaturated mono- or di-basic acid or derivative such as an ester or anhydride to provide a product which is still a resin and which now contains carboxyl or carboylic acid derivative groups, e.
The alkyd resin according to the invention is, therefore, a polyester in which in the ester linkages --O. OOC-- the --O. OOC-- from the alpha-beta olefinically unsaturated mono- or di-basic acid linked to the hydrocarbon resin.
It is peferred that the pyrolysis gasoline should be free from aralkenes such as styrene so that the resin which is produced by the Friedel Crafts polymerization does not contain any aromatic groups. It is also advantageous to add to the pyrolysis gasoline a proportion of C 4 alkenes or di-isobutene so as to obtain a ratio of C 4 to C 5 hydrocarbons in the range 0.
The C 4 alkenes may be suitably added as the mixture obtained after butadiene has been removed from a cracker C 4 stream as is described in our co-pending UK patent application No.
The dicyclopentadiene may be separated from the remainder of the pyrolysis gasoline prior to the polymerization by distilling off the latter or it may be left to take part in the polymerization.
The polymerization is preferably catalysed by a Friedel Crafts catalyst such as an inorganic halide, preferably a halide of aluminium, iron, tin, boron, zinc, antimony or titanium which may be used in conjunction with a hydrogen halide such as hydrogen chloride.
For example, treatment of the pyrolysis gasoline with aluminium chloride, preferably complexed with hydrogen chloride, in an aromatic solvent such as toluene or a xylene produces a solution from which a resin may be recovered.
Preferably, however, the Friedel Crafts catalyst is used in an aromatic solvent which is a benzene which is liquid at the temperature of the polymerisation and which is substituted by at least one secondary or tertiary alkyl group or by a cycloalkyl group, e. Such catalysts are described in our British Patent No. The catalyst is finally broken down and removed from the polymer by treatment, for example, with alcoholic ammonia, aqueous alkali or aqueous alcohol followed by one or more washes with water and, optionally, a steam distillation to remove residual monomers.
Suitable alcohols to use in the catalyst removal are alkanols containing 1 to 4 carbon atoms, e. The alpha-beta unsaturated acids or derivatives suitably contain up to 15 carbon atoms, e. Suitable derivatives of the acids include esters particularly lower alkyl C 1 to C 6 esters such as methyl methacrylate and where appropriate, the dibasic acid anhydrides. Of these maleic acid or maleic anhydride is preferred and henceforth in this specification the reaction of the hydrocarbon resin with the unsaturated acid or derivative will be referred to as the "maleinization" reaction.
The "maleinization" reaction is preferably carried out under an inert atmosphere free from oxygen, e. The resin from the Friedel Craft's polymerization may be melted and the acid or derivative, e. The duration of the reaction is up to 10 hours, acid or acid derivative being suitably added over the first half of the time and the reaction mixture being held at the desired temperature for the second half of the time.
Lighter coloured "maleinized" resins are obtained if the resin which is obtained at the end of the steam distillation after the Friedel Crafts reaction is not cooled down but is heated immediately under an inert atmosphere to the temperature at which the "maleinization" is to take place.
Maleic anhydride is preferred for use in the "maleinization" reaction. Such acids include ortho-, iso and tere-phthalic acids, an aliphatic dibasic acid containing up to 20 carbon atoms, e. The polyhydric alcohol component of the alkyd resin may be any of those conventionally used in the industry. Outstanding examples are diols, e. The monobasic acid which may form a part of the alkyd resins according to the present invention may be derived from the free acid or from an ester such as a glyceride.
The acid is suitably an aliphatic saturated or ethylenically unsaturated acid containing up to 30 carbon atoms, preferably 6 to 22 carbon atoms. Mixtures of acids or their esters may also be employed, particularly naturally occurring mixtures such as tall oil acids, linseed oil, soyabean oil, soya oil, whale oil, dehydrated castor oil, tung oil, fish oil, safflower oil, oiticica oil, cotton seed oil and coconut oil.
Individual acids which are acceptable include iso-octanoic acid, 2-ethylhexanoic acid, iso-decanoic acid, lauric acid and pelargonic acid. The olefinically unsaturated hydrocarbon resin which is used in the preparation of the alkyd resin according to the invention usually comprises a mixture of polymeric molecules of different molecular weights.
It is preferred, however, that the hydrocarbon resin be reacted with the alpha- beta-unsaturated acid or derivative in such amount that 1 to 4 gram moles of acid react with 1 gram mole of hydrocarbon resin, the molecular weight of the latter being a mean value where appropriate.
If desired, the removal of water may be facilitated by use of a suitable entrainer such as toluene or xylene. A suitable transesterification catalyst may be used in both methods of preparation, e. Alkyd resins according to the present invention are compatible with aliphatic hydrocarbon solvents and when unsaturated are useful in formulating water and alkali resistant surface coatings of improved hardness and excellent weathering properties, and hard, rapid drying lithographic inks which are hydrophobic and soluble in aliphatic solvents.
They may be used as surface coatings directly when they may be applied to the surface as solutions in suitable solvents, e. The mean molecular weight of the resin is about and it is reacted with 10 wt. The final acid value of the product was determined as 8. A suspension of 0. Following removal of the xylene by distillation the reaction mixture was cooled and the final acid value determined as 7. Over a period of 30 minutes a suspension of 0. After removal of the xylene and cooling down the final acid value was found to be 9.
Each of the resins from Examples 1 to 3 was used to prepare a paint with a pigment : binder ratio of 0. The pigment was dispersed in the paint by means of a ball mill. The formulations were as follows:. These compositions were ball-milled for 16 hours following which further quantities of resin in white spirit were added to stabilize the formulations and to prevent "pigment shock". The stabilized compositions were next made up to paint formulations for use by adding additional resin in white spirit to the stabilized millbase as follows:.
The paint formulations were completed by the addition of suitable driers. To the composition derived from the Example 1, resin was added 0. The formulations were tested as follows:. Measured on a Sward Rocker after 24 hours. Measured on a series of increasing diameter mandrels. The procedure of Example 2 was used to prepare a number of alkyd resins of different oil length derived from soyabean, linseed and tung oils.
The compositions of the alkyd resins obtained and details of their preparation are as follows:. The alkyds derived from soyabean oil and linseed oil were made up into white gloss paint formulations using as mill base 70 grams titanium dioxide and 30 grams of resin solution 20 wt. The mill base was ball milled for approximately 16 hours and stabilized against pigment shock by adding enough resin to obtain a 5 : 1 ratio of pigment to resin.
The final formulation was obtained by adding sufficient alkyd to obtain a pigment : binder ratio of 0. The driers were calculated as metal on solid alkyd resin and added to the paints. Each paint was allowed to age for three days before testing, then thinned to a known viscosity before application. Drying time, flexibility, gloss and hardness of the paint films we measured as described in Example 4. The results were as follows:. The linseed oil based resins dried faster than the corresponding oil length soyabean based resins as a result of the greater unsaturation present.
A mixture of linseed oil, pts. The final acid value was 9. A mixture of linseed oil pts. The final product had an acid value of 9. The final resin had an acid value of The ink dried in 5 hrs.
A mixture of linseed oil grams , neopentyl glycol 66 grams and litharge 0. To grams of the alkyd prepared as above was added to 50 grams of one of four oils and the drying times of the compositions measured as 50 wt.
At least a part of the polybasic acid component of an alkyd resin comprises the reaction product of an olefinically unsaturated hydrocarbon resin, e. Preferably the condensation product also comprises a monobasic acid. The invention will now be further described with reference to the following Examples. The compositions of the alkyd resins obtained and details of their preparation are as follows: Wt.
The results were as follows: Drying Times hrs. Drying times are in general longer the longer the oil length. An ink based on this alkyd resin dried in 3 hrs. The results were as follows: Wet Film Thickness 0. We claim: 1. In an alkyd resin which comprises the condensation product of a polybasic acid and a polyhydric alcohol, the improvement whereby part at least of the polybasic acid is the reaction product of an olefinically unsaturated hydrocarbon resin with an alpha, beta-olefinically unsaturated monobasic acid, dibasic acid, or derivative thereof selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, itaconic acid anhydride, citraconic acid anhydride, mesaconic acid and the lower alkyl esters of these acids.
The alkyd resin as claimed in claim 1 in which the condensation product also comprises a monobasic acid.
An alkyd resin as claimed in claim 1 in which the condensation product comprises an ester of a monobasic acid. An alkyd resin as claimed in claim 1 in which the hydrocarbon resin is produced by the polymerization of a pyrolysis gasoline using a Friedel Crafts catalyst.
An alkyd resin as claimed in claim 4 in which C 4 alkenes or di-isobutene is added to the pyrolysis gasoline prior to the polymerisation to the resin. An alkyd resin as claimed in claim 1 which is derived from a. An alkyd resin as claimed in claim 7 which also includes an additional polybasic acid selected from the group consisting of ortho-, iso- and terephthalic acid, an aliphatic dibasic acid containing up to 20 carbon atoms, trimellitic acid and pyromellitic acid.
USA en. JPSA en.
The present invention relates to novel alkyd resins, to their preparation and to compositions containing them. An alkyd resin may be generally considered as the polyester condensation product of a polyhydric alcohol and a polybasic acid, the polyester usually being chain-terminated by means of a monobasic acid. Compositions containing alkyd resins are widely used in the surface coating industry in which an alkyd resin containing olefinic unsaturation in solution in a solvent, suitably a hydrocarbon solvent, is blended in the cold with other resin or polymer solutions to give a clear finish or is used as the vehicle for pigment grinding to form ultimately a coloured surface coating which oxidises in the presence of air to a hard film. The components of the alkyd resin obviously exert an effect on its properties. For example, if the monobasic acid is unsaturated a "drying alkyd" is obtained in which chemical reaction takes place in the surface coating after application. If the monobasic acid is substantially saturated then a "non-drying alkyd" is obtained.
US3965059A - Alkyd resin - Google Patents
We'd like to understand how you use our websites in order to improve them. Register your interest. Water-based clear stoving coating materials could be prepared by mixing the water-reducible palm stearin alkyds with a commercial methylated melamine formaldehyde in ratios ranging from 1 to 9. TGA analysis could be used to estimate the solid content of each of the coatings, as well as the curing temperature that could be used to prevent thermal degradation. This is a preview of subscription content, log in to check access. Paul S, Progr. Google Scholar.