JPS5811894B2 - Kechiminki Oyuusuru Shinki Prepolymer Seihou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Japanese Patent Application No. 47-034806 describes new prepolymers containing enamine groups prepared by reacting monoenamines containing free hydroxyl groups with polyisocyanates.

A particular embodiment described therein is an addition in which the monoenamine with free hydroxyl groups is a monoenamine based on 1-(2-hydroxyethyl)piperazine and the polyisocyanate consists of polypropylene glycol and an excess of diisocyanate. Patent application No. 47-034806 also relates to a process for the preparation of prepolymers having enamine groups, which comprises a compound having at least one secondary amino group and an aliphatic hydroxyl group. (1) in the first step reacting with a fatty aldehyde group or a cyclic ketone, the reaction being carried out optionally by contacting with an acid and optionally by supplying heat or cooling, with or without a solvent; (2) the compound obtained in the first step is added to the polyisocyanate in such an amount that it is equivalent to the hydrogen of the hydroxyl group in the second step; It is characterized by reacting with

It has now been found that new prepolymers with ketimine groups can be prepared by reacting mono-ketimines with free hydroxyl groups with polyisocyanates.

A further embodiment of the prepolymer according to the invention is characterized in that the polyisocyanate is an aliphatic polyisocyanate.

A further embodiment of the prepolymer according to the invention is characterized in that the polyisocyanate is an addition product of polyproethylene gellicol and excess diisocyanate.

The present invention also relates to a method for preparing a prepolymer having ketimine groups, which comprises: (1) treating a compound having at least one primary amino group and an aliphatic hydroxyl group with an aliphatic or cyclic ketone in a first step; The reaction is carried out with or without a solvent, optionally by contacting with an acid, optionally by supplying heat or by cooling, and the corresponding reaction water and an excess of The carbonyl compound is removed and (2) the compound obtained in the first step is reacted in a second step with an amount of polyisocyanate which is equivalent to the hydrogen of the hydroxyl group.

A further embodiment for producing prepolymers with ketimine groups is characterized in that the polyisocyanate is an addition product of polypropylene glycol and excess diisocyanate.

It was previously unknown that a ketimine having a hydroxyl group could be added to an isocyanate while maintaining the original ketimine structure to generate a urethane group.

On the other hand, it is described in the literature that ketimines can be reacted with incyanates to give cycloaddition products or products with amide or urea groups [K. Harada, Macromolecules.・Hiemie” (Makromol.

Chem,) Vol. 132, pp. 295-304 (1970
Year)〕.

The production of ketimine according to the present invention involves adding an excess carbonyl component to a primary amine and adding a suitable solvent (toluene/benzene), followed by heating in a water separator under nitrogen until water precipitation is completed. It is carried out as follows.

In some cases the carbonyl moiety itself may act as an ejection agent.

Distillation of ketimine is advantageous.

However, the crude product can also be used immediately after removing excess carbonyl component and solvent.

Particularly suitable carbonyl components are aliphatic and cyclic ketones.

Examples of ketones which are advantageously used for preparing ketimines are: diclopentanone, trimethylcyclopentanone, cyclohexanone, trimethylcyclohexanone and other substituted cyclohexanones and cyclopentanones and methyl isobutyl ketone. , methyl ethyl ketone, diethyl ketone, diisopropyl ketone, etc.

For the addition of ketimines with hydroxyl groups, preaddition products consisting of polypropylene glycol and excess aliphatic diisocyanate can be used.

The basic polypropylene glycols are linear or branched products with an average molecular weight between 500 and 10,000.

It is advantageous to use aliphatic diisocyanates with various reactive incyanate groups, since chain extension is thereby avoided.

Diisocyanates of this type are, for example, inphorone diisocyanate and trimethylhexamethylene diisocyanate.

If chain extension is desired, hexamethylene diisocyanate, 1-methyl-2,4-diisocyanatecyclohexane or 4,4'-diisocyanatedicyclohexylmethane can be used.

A ratio of inocyanate groups to hydroxyl groups of 1.8 to 2.2 is preferably used for the diisocyanates 1.

It is generally expedient to mix the components under cooling at 0 DEG to 30 DEG C. and to add a catalyst, for example an organotin compound or a tertiary amine.

The mixture is then heated to an elevated temperature, preferably from 50 DEG to 100 DEG C., until the analytically determined isocyanate content reaches the calculated value.

The ketimine containing hydroxyl groups is preferably mixed into the incyanate preaddition product in a ratio NCO10H=1.

Mixing should be carried out at a temperature of 0 DEG to 30 DEG C., with vigorous stirring and optionally cooling.

Mix until no more free incyanate can be detected by infrared spectroscopy.

The ketimine addition products according to the invention can be used as amine-eliminating compounds, for example for moisture-curing polyurethane bulks.

For this purpose, the addition product is masked (ver.
kappen) aromatic polyisocyanate in approximately stoichiometric ratios.

Masked polyisocyanates include, for example, addition products of trimethylolpropane and 2°4-toluolylene diisocyanate in a molar ratio of 1:3, the free isocyanate groups being masked with phenol. good.

Additionally, addition products with nonylphenol-masked residual isocyanate groups consisting of polypropylene glycol and 2.4-toluolylene diisocyanate can be used.

Example 1 1(a) 91.5 g of ethanolamine, 225 g of methyl isobutyl ketone and 100 ml of benzene are pre-charged into a three-necked flask having a capacity of 11 and having a water separator and a stirrer.

Heat under reflux until the calculated amount of water is precipitated.

Excess ketone and solvent are then removed and the residue is distilled in vacuo.

Boiling point 53℃ 10.5mm Analysis: CHN Calculated value 567% 11.9% 9.8% Actual value 66.8% 12.1% 9.8% A strong ketimine band in the infrared spectrum is 1655Crn
−' is found.

Formula of reaction product: 1(b) 5.7 g of dibutyltin dilaurate is added to a mixture consisting of 5040 g of trifunctional polypropylene gel IJ-3-3 having an OH number of 35.6 and inphorone diisocyanate-1-71L9'. Add and stir for 3 hours at 75° C. under nitrogen.

The reaction product has an incyanate content of 2.2% by weight,
This corresponds to an equivalent weight of 1914.

1(c) 7483 g of the hydroxyl group-containing ketimine prepared in (a) are added to the prepolymer 1001 with incyanate end groups prepared in (b) while cooling.

Care is taken that the temperature does not rise above 30° C. while stirring vigorously.

No free incyanate is detected in the infrared spectrum of the barley that has been stirred for 4-5 hours.

In contrast, the ketimine zone remained unchanged.

The product has an equivalent weight of 2057.

Example 2 2(a) 100 TL of benzene is added to a mixture of 105 g of diglycolamine and 150 I of cyclohexanone and heated for 4 hours using a water separator.

17.69 g of water is precipitated. Excess ketone and solvent are removed and the residue is distilled in vacuo.

Boiling point 103℃/0.2mm analysis: CHN Calculated value 64.8% 10.3% 7.6% Actual value 64.8% 10.3% 8.0% The reaction product has the formula:

2(b) 1000 g of the prepolymer with isocyanate end groups prepared in 1'(b) are mixed with 96.6y of the ketimine prepared in 2(a) while cooling and with vigorous stirring.

During the reaction the temperature is kept below 30°C.

After stirring for 5 hours, free incyanate is no longer detected in the infrared spectrum.

The product has an equivalent weight of 2100.

Example 3 3(a) Add 300.5 g of methyl isobutyl ketone and 300 ml of benzene to 324 g of diglycolamine.

The mixture is heated in a water separator under nitrogen until water precipitation is complete.

The solvent is removed and the residue is distilled in vacuo.

The reaction product has the following formula: 3(b) 97.8 g of the ketimine prepared in 3(a) are added to 1000 g of the incyanate end-terminated prepolymer prepared in (b) with stirring and cooling. Added.

After 4 hours of stirring free incyanate is no longer detected by infrared spectroscopy.

The product has an equivalent weight of 2012.

Example 4 4(a) 1,6117 g of hexanolamine are heated with 150 g of cyclohexanone and 100 g of Penzol in a water separator until no more water of reaction is formed.

The reaction is complete after about 6 hours.

Excess ketone and benzene are removed in vacuo and the residue is distilled in vacuo.

Boiling point 153°C 10.8mm.

Analysis: CHN Calculated value 73.0% 11.7% 7.1% Actual value 73.5% 11.7% 6.8% A strong C=N band is recognized in the infrared spectrum at 1660%.

The reaction product has the formula:

4(b) Inphorone diisocyanate 22 to 1356 g of branched polypropylene glycol with OH number 35.6
1. ? and dibutyltin dilaure-1-1,8,p are added.

The reaction mixture is heated to 75° C. and maintained at that temperature with good stirring for 2.5 hours.

The reaction product has an isocyanate content of 2.39%.

4(e) 1000 g of the prepolymer incyanate prepared in Example 4(b) are stirred together with 112.2 g of the hydroxyl-bearing ketimine prepared in Example 4(a) at room temperature.

After the mixture has been left to stand for about 12 hours, free isocyanates are no longer detectable in the infrared spectrum.

Claims (1)

[Claims] 1. In producing a prepolymer having a ketimine group, a compound having at least one primary amine group and an aliphatic hydroxyl group is (1) reacted with an aliphatic or cyclic ketone in the first step; is carried out with or without a solvent, optionally by contacting with an acid, optionally by supplying heat or cooling, and removing the corresponding water of reaction and excess carbonyl compound, and (2) A method for producing a novel prepolymer having ketimine groups, characterized in that the compound obtained in the first step is reacted in the second step with an amount of polyisocyanate that is equivalent to the hydrogen of the hydroxyl group.