Air Drying Reaction Product of a Diisocyanate and 1-Methyl-2-Vinyl-4,6-Heptadienol

This invention relates to an air drying material useful as a paint, adhesive, sealant, caulking agent, vehicle for printing ink or other similar applications. The material is novel and cures in air at room temperature.

Heretofore, an air drying type alkyd resin modified with an aliphatic acid has been used in large quantities as paint, adhesive, sealant, caulking agent, vehicle for printing ink or the like. However, when an alkyd resin is used for these applications, a solvent acting as a thinner must be used with the resin to increase its workablity. A solvent is only required at the time of use of the alkyd resin. After application the solvent dissipates into the atmosphere. From the stand-point of air pollution control, safety for workers and saving of resources, therefore, the use of a solvent is not always desirable.

An object of the present invention is, therefore, to provide a novel air drying material which can be applied for the applications mentioned above without using a solvent.

This object and the other objects of the present invention will become apparent from the following description.

It has now been discovered that the material obtained by mixing a diisocyanate compound with 1-methyl-2-vinyl-4,6-heptadienol and by then ageing the mixture is satisfactorily capable of curing in air at room temperature.

According to the present invention, there is provided an air drying type material formed by reacting a diisocyanate compound and 1-methyl-2-vinyl-4,6-heptadienol of the formula: ##STR1##

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing represents an infrared absorption spectrum of the viscous material obtained when a 1 mole of 1-methyl-2-vinyl-4,6-heptadienol is mixed with 0.5 mole of tolylene-2,4-diisocyanate and is stirred in a dry nitrogen atmosphere at room temperature for ten hours.

The 1-methyl-2-vinyl-4,6-heptadienol used in the present invention is produced by reacting butadiene with an aldehyde in the presence of a palladium complex catalyst. The 1-methyl-2-vinyl-4,6-heptadienol is a transparent liquid having a boiling point of 60.degree. - 66.degree. C/2 mmHg and has been disclosed in pages 3813 to 3816 of "Tetrahedron Letters" No. 43 (England, 1970). Further, this compound is highly reactive since it has a conjugated double band and a vinyl substituent in its molecule.

The diisocyanate compound used in the present invention may be an aliphatic compound, an aromatic compound or a prepolymer. The diisocyanate compounds satisfying the purpose of this invention include tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate with 2,6-tolylene diisocyanate, hexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, phenylene diisocyanate, octamethylene diisocyanate and a dimer of tolylene diisocyanate, for example. The diisocyanate compound may be an adduct of a diisocyanate compound and a polyhydroxy-compound having two or more hydroxyl groups, such as the adduct of trimethylol propane and tolylene diisocyanate. Examples of the prepolymers are polyarylene polyisocyanate; a polyhydroxy-compound having isocyanate groups in the terminal positions thereof which is obtained by reacting a diisocyanate compound with a polyglycol; and a prepolymer obtained by reacting a diisocyanate compound with a polyester having amino groups, a polyether or a polyamide.

The of the present invention is composed of the diisocyanate compound and the 1-methyl-2-vinyl-4,6-heptadienol. The former may be used in an amount of 0.2 to 2 moles, preferably 0.4 to 0.8 mole per 1 mole of the latter. The composition is used after ageing to a suitable viscosity by simply leaving it under a dry nitrogen atmosphere at room temperature for 1-24 hours or by maintaining it under a dry nitrogen atmosphere at 40.degree.-80.degree. C for 0.5 to 5 hours. The composition of the present invention thus aged can cure in air at room temperature. When the composition cures, it is believed that the isocyanate group reacts with 1-methyl-2-vinyl-4,6-heptadienol to form urethane bonds and biuret bonds.

The composition thus aged may be also used with an alkyd resin and consequently the alkyd resin can be employed without using the solvent such as a thinner. If necessary, a curing catalyst such as cobalt naphthenate or lead naphthenate and an additive such as a pigment or filler, which are usually added to the alkyd resin may be added to the aged composition of the present invention.

The present invention will be described below more specifically with reference to the preferred embodiments; however, it is not limited to these examples.

1 mole of 1-methyl-2-vinyl-4,6-heptadienol was mixed with 0.5 mole of tolylene 2,4-diisocyanate. The resultant mixture was stirred under a dry nitrogen atmosphere at room temperature for 10 hours to age and thereby form a viscous material. The infrared absorption spectrum of this material was then measured. The spectrum revealed that the absorption range of "--C.dbd.O" was present at 1700 cm.sup.-1. The spectrum is shown in the accompanying drawing. In the drawing, the vertical axis represents percent transmission and the upper horizontal axis shows wave length (micron) and the lower horizontal axis shows frequency (cm.sup.-1).

The material was coated on a glass plate and the film was left in air at room temperature for 8 hours. The film cured perfectly.

The viscous material was prepared by using crude tolylene diisocyanate (TDI) of accordance with the same procedure in Example 1. In these examples, the mol ratio of TDI to 1-methyl-2-vinyl-4,6-heptadienol and the reaction conditions were varied. 50 parts of these resultant viscous materials were blended with 25 parts of titanium oxide, 5 parts of zinc oxide and 20 parts of calcium carbonate to prepare various paints. A week after coating with these paints, the film properties were measured. The resins used, the composition of and the characteristics of the paints are listed in Table 1 below.

As apparent from Table 1, the film properties obtained by using the composition of the present invention are comparable to conventional products and particularly excellent in hardness.

13 g of 1-methyl-2-vinyl-4,6-heptadienol was mixed with 100 g of Hi-prene P302 (urethane prepolymer produced by Mitsui-Toatsu Co., Ltd.; containing 3.2% by weight of isocyanate). The resultant mixture was stirred under a dry nitrogen atmosphere at 50.degree. C for 3 hours to form a viscous material. A paint was formulated using the resultant material by the same procedure of Example 2. Then, the film properties were measured. The results are listed in Table 2 below.

20 g of 1-methyl-2-vinyl-4,6-heptadienol was mixed with 100 g of Sunprene SEL 11 (urethane prepolymer produced by Sanyo Kasei Co., Ltd.; containing 5.1% by weight of isocyanate). The resultant mixture was tested according to the same procedure used in Example 2. The results were listed in Table 2 below.

30 g of 1-methyl-2-vinyl-4,6-heptadienol was mixed with 100 g of Sunprene FLR 15 (urethane prepolymer produced by Sanyo Kasei Co., Ltd.; containing 7.5% by weight of isocyanate). The resultant mixture was tested according to the same procedure used in Example 2. The results are shown in Table 2 below.