Field of the Invention

This invention relates to novel oxime blocked isocyanates based on TMI® (META) unsaturated aliphatic isocyanate. Specifically, the invention relates to novel compositions of methyl isobutyl ketoxime-N-(m- isopropenyl-α, α-dimethyl benzyl) carbamate, methyl amyl ketoxime-N-(m-isopropenyl-α, α-dimethyl benzyl) carbamate, di-isobutyl ketoxime-N-(m-isopropenyl-α, α- dimethyl benzyl) carbamate and di-isopropyl ketoxime-N- (m-isopropenyl-α, α-dimethyl benzyl) carbamate. These compounds are useful in a variety of industrial applications including coatings, adhesives and tackifiers, textile fibers and finishes, speciality plastics and rubber applications and agricultural chemical formulations.

BACKGROUND OF THE INVENTION

Blocked isocyanates are frequently used, for example, in high solids coating formulations and also in powder coating formulations to improve the stability of the formulation on storage.

It is primary object of this invention to provide new oxime-blocked isocyanates based on TMI® (META) unsaturated aliphatic isocyanate.

*TMI®(META) unsaturated aliphatic isocyanate is a registered trademark of American Cyanamid Company.

SUMMARY OF THE INVENTION

The invention relates to novel compositions of methyl isobutyl ketoxime-N-(m-isopropenyl-α, α-dimethyl benzyl) carbamate, methyl a yl ketoxime-N-(m- isopropenyl-α, α-dimethyl benzyl) carbamatye, di- isobutyl ketoxime N-(m-isopropenyl-α, α-dimethyl benzyl) carbamate and di-isopropyl ketoxime-N-(m- isopropenyl-α, α-dimethyl benzyl) carbamate which are useful in a variety of industrial applications including coatings, adhesives and tackifiers, textile fibers and finishes, specialty plastics and rubber applications and agricultural chemical formulations.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the invention, novel oxime- blocked isocyanaytes based on TMI® (META) unsaturated aliphatic isocyanate* (hereinafter referred to as "TMI isocyanate") have been discovered. TMI isocyanate is a known material which is commercially available through American Cyanamid Co. Alternately, it may be synthesized by known techniques.

*Phys cal properties: TMI isocyanate appearance: colorless liquid molecular formula : C ₁₃ H ₁₅ NO molecular weight: 201.26

NCO content: 20.9% (theoretical) boiling point: 270"C (latm) vapor pressure: 2mm Hg (100°C) viscosity: 3 cp (27°C) density: 1.01 g/ml solubility: vinyl monomers, most common solvents

TMI isocyanate is a bifunctional monomer containing a tertiary aliphatic isocyanate group and a reactive double bond.

The novel oxime-blocked TMI isocyanates of this invention may be prepared by reacting TMI isocyanate with the appropriate oxime.

When the oxime is methyl isobutyl ketoxime, R and R ¹ comprise a methyl and isobutyl group respectively and the resulting oxime-blocked TMI isocyanate is methyl isobutyl ketoxime-N-(m-isopropenyl-α, α-dimethyl benzyl) carbamate. Similarly, when the oxime is methyl and amyl ketoxime, R and R ¹ comprise a methyl group and amyl group respectively and the resulting oxime-blocked TMI isocyanate is methyl amyl ketoxime-N-(m-

isopropenyl-α, α-dimethyl benzyl) carbamate. When the oxime is di-isobutyl ketoxime, R and R ¹ each comprise an isobutyl group and the resulting oxime-blocked TMI isocyanate is di-isobutyl ketoxime-N-(m-isopropenyl-α, α-dimethyl benzyl) carbamate. Similarly, when the oxime is di-isopropyl ketoxime, R

and R ¹ each comprise an isopropyl group and the resulting oxime-blocked TMI isocyanate is di-isopropyl ketoxime-N-(m-isopropenyl-α, α-dimethyl benzyl) carbamate. A detailed synthesis of these compounds may be found in Examples 1-4 below.

EXAMPLE 1

Preparation of methyl isobutyl ketoxime-N-(m- isopropenyl-α, α-dimethyl benzyl) carbamate. To a one liter 3-necked flask equipped with a thermometer, agitator and nitrogen gas purge was added 306 grams of TMI and 5 drops of dibutyltin dilaurate. The mixture was then heated to 90°C. To this mixture, 179 grams of methyl isobutyl ketoxime was added dropwise over a 15 minute period maintaining the reactor temperature at about 90-100°C. After addition of the methyl isobutyl ketoxime, the reaction was held at about 100-105"C for 30 minutes with continued agitation. The product was poured into paint cans for storage. 425 grams of product were obtained for an 87.6% yield. The product -oxime-blocked TMI isocyanate ahd the following properties:

Free NCO content, % - 0

Color (APHA) - 10

Viscosity (Gardner-Holdt) - W-X Equivalent weight (calc.) - 317

EXAMPLE 2

Preparation of methyl amyl ketoxime-N-(m- isopropenyl-α α-dimethyl benzyl carbamate. To a one liter 3-necked flask equipped with a thermometer, agitator and nitrogen purge gas was added 300 grams of TMI and 5 drops of dibutyltin dilaurate. The mixture was then heated to about 90°C. To this mixutre was added 197 grams of methyl amyl ketoxime dropwise over a 20 minute period with minimum cooling. After addition of the methyl amyl ketoxime, the reaction was held at about 100-105°C for 30 minutes with continued agitation. The product was poured into paint cans for storage. 445 grams of product were obtained for an 89.5% yield. The properties of the product oxime blocked TMI were as follows:

Free NCO content, % - 0

Color (APHA) - 30 Viscosity (Gardner-Holdt) - L-M

Equivalent wieght (calc.) - 331

EXAMPLE 3

Preparation of di-isopropyl ketoxime-N- (m- isopropenyl-α. α-dimethyl benzyl) carbamate. To a one liter 3-necked flask equipped witha thermometer, agitator and nitrogen purge is added 301 grams of TMI isocyanate and 5 drops of dibutyltin dilaurate and the mixture is heated to 90°C. To this mixutre is added 197 grams of di-isopropyl ketoxime dropwise over a 20 minute period with minimum cooling. After addition of the di-isopropyl ketoxime, the reaction is held at 100- 105°C for 30 minutes with continued agitation. The

product is poured into paint cans for storage. The equivalent weight of the product is 330.

EXAMPLE 4

Preparation of di-isobutyl ketoxime-N-(m- isopropenyl-α, α-dimethyl benzyl) carbamate. To a

one liter 3-necked flask equipped with a thermometer, agitator and nitrogen purge, is added 301 grams of TMI isocyanate and 5 drops of dibutyltin dilaurate and the mixture is heated to 90°C. To this mixutre is added 240 grams of di-isobutyl ketoxime dropwise over a 20 minute period with minimum colling. After addition of the di-isobutyl ketoxime, the reaction is held at 100- 105°C for 30 minutes with continued agitation. The product is poured into paint cans for storage. The equivalent weight of the product is 358.

The novel oxime-blocked TMI isocyanates of this invention may be blended together or with other known oxime-blocked TMI isocyanates depending on the properties desired. For example, blends may be used to improve the working viscosity during polymerization reactions with other reactants or to increase the solids content in order to reduce the level of volatile organic components. The blends may be prepared in situ or by physically blending the oxime-blocked isocyanates together. The oxime-blocked TMI isocyanates may be combined in any proportions.

Oxime-blocked TMI isocyanates are unqiue molecules. The double bond in the oxime blocked TMI isocyanate undergoes free radical polymerization

readily with various unsaturated monomers yielding copolymers with pendant, isocyanate functionality.

CH,

The resulting polymer is stable in the presence of a hydroxyl functionality (i.e. a polyol) , an amine functionality (i.e. a polyamine) and water and may be used 1.) as is, 2.) in a solvent such as a ketone, ester or aromatic or 3.) in a dispersion and/or 4.) in an emulsion in water.

The blocked TMI isocyanate that has undergone copolymerization with, for example, acrylates, hydroxy acrylates, methyl methacrylates, hydroxy methacrylates, acrylonitrile or styrene can be belnded with a polyol (i.e. acrylic, polyester or polyether) or a polyamine (i.e. Jeffamine T-403*) to form a stable one package coating, adhesive or elastomer. Curing is effected by liberating the free isocyanate group at elevated temperature for subsequent reaction with the polyol or polyamine. The reaction is schematically represented as follows for methyl amyl ketoxime-N-(m-isopropenyl-α, α-dimethyl benzyl) carbamate.

*Jeffamine®T-403 is a requested Trademark of Texaco Chemical Co.

EXAMPLE 5

Table I

Raw materials Parts by weight

Charge A: butyl acrylate 45.9 water ¹ 25.8

AEROSOL® OT surfactant ² 1.38 n-Octyl mercaptan 0.78

Charge B: methyl methacrylate 40.8 water 23.1

AEROSOL OT surfactant 1.20

Charge C: methyl amyl ketoxi e- 44.8 N-(m-isopropenyl-α, α- dimethyl benzyl) carbamate water 23.1 n-Octyl mercaptan 0.47

Charge D: Tert-buty hydroperoxide ³ 1.8 water . 33.0

Charge E: sodium formaldehyde 3.60 sulfoxylate ethylenediamine- tetraacetis acid tetrasodium salt 0.19 ferric chloride hexahydrate 0.04 water 50.02

Charge F: AEROSOL 102 surfactant 2.48

Charge E 11.31 water 17.12

^se deionized water throught.

² AEROSOL® OT surfactant is a registered trademark of American Cyanamid Co.

³ Use TBHP-70X water dispersible grade (Lucidol Div. , Pennwalt Corp.)

Procedure: Place charge F in a 250 ml fitted flask. Start metered additions of charges A, B, C, D simultaneously, using 26.9 grams of A during 1.2 hours, 17.7 grams of B during 2.3 hours and 15.6

gra s of C during 3.0 hours and Charge D on a schedule of 6.5 grams during the first 10 minutes, then 8.7 grams during the first 10 minutes, then 8.7 grams during the next 3.5 hours. The flask is maintained at 25°C by external water cooling. At the end of the Charge D addition, the pH is 6.6 and the measured soldis are 44.1%. No coagulu was obtained. The results indicate that methyl amyl ketoxime-N-(m- isopropenyl-α, α-dimethyl benzyl) carbamate can be used to produce one package coatings which are stable.

EXAMPLES 6 - 8

The experiment outlined in Example 5 above is repeated except that the oxime blocked TMI isocyanates listed in Table II below are substituted for methyl amyl ketoxime-N-(m-isopropenyl-α, α-dimethyl benzyl carbamate. The results indicate that stable one package coatings may be prepared using the oxi e- blocked TMI isocyanates listed in Table II.

TABLE II

methyl isobutyl ketoxime N-(m-isopropenyl-α, α- dimethyl benzyl) carbamate

di-isobutyl ketoxime N-(m-isopropenyl-α, α- dimethyl benzyl) carbamate

di-isopropyl ketoxime N-(m-isopropenyl-α, α- dimethyl benzyl) carbamate