JPS59172514A - Production of one-component urethane resin - Google Patents

Abstract

PURPOSE:To facilitate the production of the titled low-viscosity resin excellent in the properties of a cured product obtained by moisture curing, by reacting an active hydrogen-containing liquid diene polymer with an organic polyisocyanate compound and a specified polyol. CONSTITUTION:The titled resin is produced by reacting (A) an active hydrogen- containing liquid diene polymer (e.g., butadiene homopolymer) with (B) a low- MW polyol having at least one hydroxyl group bonded to a secondary carbon (e.g., 1,2-propylene glycol) and (C) an organic polyisocyanate compound which reacts with the active hydrogen groups in A and B to form a one-component urethane resin (e.g., diphenylmethane diisocyanate). The selection of the above specified polyol makes it possible to obtain the titled resin having excellent properties of a moisture-cured product, low viscosity because of controlled thickening, etc., during its production, and excellent storage stability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to -method for producing liquid urethane resin- (-1
DETAILED DESCRIPTION The present invention relates to a method for producing a liquid urethane resin that is easy to produce and provides a cured product with excellent physical properties by selecting a specific polyol.

Conventionally, two-component polyurethane elastomers obtained by reacting active hydrogen group-containing liquid diene polymers with organic polyinsyanate compounds as raw materials for urethane resins have been widely used due to their excellent low-temperature properties and water resistance. used in the field of

However, this two-component reactive urethane resin has a very fast curing reaction, and can be used to form sheets etc. using various kneading machines and molding machines, or as a modifier for road paving asphalt, and as a coating agent. However, in the field of adhesives, it is not possible to take sufficient time for molding or working, and the physical properties of the resulting cured product are also insufficient.

Therefore, in order to improve the physical properties of the cured product, attempts have been made to add low molecular weight compounds such as ethylene glycol and 1,4-butanediol, and although some improvement in physical properties has been achieved, workability is It has not been found to be a fundamental solution.

Therefore, as a further improvement, a moisture-curable liquid range urethane resin, which is a liquid diene polymer containing incyanate groups obtained by reacting a liquid diene polymer containing active hydrogen groups and an organic polyisocyanate compound, has been developed. Are known. However, the cured product obtained by moisture curing of pear-shaped urethane resin does not have sufficient physical properties, especially elongation properties.
For example, when used as an adhesive, it has the drawback of insufficient peel strength and lack of reliability.

The present inventor has conducted extensive research into improving the physical properties of cured products of one-component urethane resins useful as adhesives, coating agents, asphalt, resin modifiers, etc. Various studies were conducted on the effects of adding other polyols to l-based polymers. As a result, it has been found that when a specific polyol is used, a liquid-type urethane resin that eliminates the conventional drawbacks can be efficiently obtained. The present invention has been completed based on these findings.

That is, the present invention is characterized by reacting (N liquid diene polymer containing active hydrogen groups, (B) a low molecular weight polyol containing a hydroxyl group bonded to at least one secondary carbon, and (Q organic polyisocyanate compound). The present invention relates to a first invention that provides a method for producing a one-component urethane resin, and a second invention that provides a more preferable method for producing a one-component urethane resin in which the reaction is carried out in the presence of a plasticizer.

The active hydrogen group-containing liquid diene polymer (A) used in the present invention has an active hydrogen group such as a hydroxyl group, an amine group, an imino group, a carboxyl group, or a mercapto group at the molecular end and has a number average molecular weight of 300 to 300. 25000° preferably 1-j, 5
It is a liquid diene polymer of 00 to ioooo. These liquid diene polymers include diene polymers and diene copolymers having 4 to 12 carbon atoms, and copolymers of these diene monomers and α-olefinic addition polymerizable monomers having 2 to 22 carbon atoms. be. Specifically, butadiene pomopolymer, imbrene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer.

Examples include butadiene-2-ethylhexyl acrylate copolymer and butadiene-n-octadecyl acrylate copolymer.

These liquid diene polymers can be produced, for example, by subjecting a conjugated diene monomer to a heating reaction in the presence of hydrogen peroxide in a liquid reaction system. The liquid diene polymer thus obtained contains an average of 1.7 to 3.0 hydroxyl groups as functional groups. The fine structure of these liquid diene polymers is not particularly limited, but when flexibility is desired, those having 1,4 bonds of 50% or more are used.

Next, the low molecular weight polyol (B) containing a hydroxyl group bonded to at least one secondary carbon used in the present invention includes 1,2-propylene glycol, dipropylene glycol, and i,2-butanediol.

1.3-butanediol, 2.6-butanediol, 1
, 2-bentanediol, 2,3-bentanediol,
2,5-hexanediol, 2,4-hexanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, glycerin, N,N-bis-2-hydroxypropylaniline, N,N'-bishydroxy Examples include isopropyl-2-methylpiperazine and an ethylene oxide adduct of bisphenol A.

As the polyol used in the present invention, a diol is usually used, and more preferably a diol having two hydroxyl groups bonded to a secondary carbon is used, and its molecular weight is 50 to 500.
It is within the range of .

In the present invention, polyols include ethylene glycol containing I to no hydroxyl group bonded to secondary carbon, 1.3-
Globylene glycol, 1,4-butanediol, 1'
, ``If 5-bentanediol, 1゜6-hexanediol, etc. are used, the reaction system will increase in viscosity], and in some cases solidification may occur, making it impossible to achieve the purpose of the present invention. There is no particular restriction on the amount of the low molecular weight polyol containing a hydroxyl group bonded to at least one secondary carbon; The molecular weight and active hydrogen group content of the system polymer and the molecular weight and hydroxyl group content of the polyol are considered (-) and determined as appropriate.

However, usually (A):(B)=8:2~2;8
(equivalence ratio).

Next, examples of the organic polyisocyanate compound to be reacted with the active hydrogen group of (AJ, (B)) to obtain a one-component urethane resin include tolylene diisocyanate, diphenylmethane diincyanate (MDI),
Crude MDI, liquid modified product of diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, cyclohexanephenylene diisocyanate *-), chlorophenylene diisocyanate, naphthalene-1,5-diisocyanate, xylylene-2,2'
-Diisocyanate, isopropylbenzene-2,4-
Examples include diisocyanate, polymethylene polyphenylisocyanate, triphenylmethane triisocyanate, inphorone diisocyanate, addition reaction product of polypropylene glycol or triol and tolylene diisocyanate, addition reaction product of 1 mole of trimethylolpropane and 6 moles of tolylene diisocyanate, etc. The reaction to obtain the one-liquid area urethane resin of the present invention is usually performed using N
CO/active hydrogen group (equivalent ratio) 16 or more, preferably 2.
0 or higher and the reaction temperature is 10 in an inert atmosphere such as dry nitrogen.
The reaction is carried out under conditions of ~150C and a reaction time of 0.5 to 10 hours. If the equivalent ratio of the organic polyisocyanate compound is small, chain extension due to urethane reaction will occur, resulting in high molecular weight (2) and thickening, which is undesirable.On the other hand, if it is too large, the organic polyisocyanate compound monomer will remain. , which is unfavorable from a safety point of view.

The method of the present invention can be carried out essentially without a solvent, but if necessary, a solvent without active hydrogen groups may be used, such as ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, acetone, toluene. , xylene, tetrahydrofuran, dioxane, dimethylacetamide, etc. However, when these solvents are used, there is a drawback that these solvents must be removed from the reaction product after producing the pear-shaped urethane resin. However, the use of these solvents lowers the viscosity of the reaction system and reduces the NCO
/active hydrogen group (has the advantage of suppressing the increase in molecular weight due to the urethane reaction even if the equivalent ratio is relatively small.The inventors believe that it is not necessary to specifically remove it from the reaction product. After investigating various media, we found that free NO in the reaction product was reduced by reacting in the presence of a plasticizer.
It has been found that even if the reaction is carried out under conditions where C is less than 5% by weight, the reaction can be carried out without any inconvenience, and the resulting one-component urethane resin has a low viscosity and particularly excellent elongation properties. It was ~ta.

The manufacturing method of the second aspect of the present invention has been completed based on these findings.

The plasticizer used here is not particularly limited and various types can be used, such as dibutyl phthalate) I
Cy2-ethylhexyl phthalate.

Phthalic acid esters such as di-n-octyl phthalate, linear dibasic acid esters such as dioctyl adipate, dioctyl azelate, dioctyl sebacate, tri-2-ethylhexyl phosphate, cresyl phosphate, tricylenyl phosphate, etc. Examples include oils such as phosphoric acid esters, naphthenic oils, aroma oils, and alkyl aroma oils.

The plasticizer used here may be selected as appropriate depending on the use of the one-component urethane resin, taking into account heat resistance, cold resistance, chemical resistance, electrical properties, compatibility with other raw materials, etc.

There is no particular restriction on the amount of plasticizer used, and it is within the range of 0 to 70% by weight, preferably 20 to 50% by weight, based on the corrugated urethane resin, and can be determined as appropriate by law in consideration of workability, usage, etc. Bye.

Furthermore, in the production method of the present invention, a tertiary amine, metal salt, or organometallic compound may be used as a catalyst if necessary.

As detailed above, the manufacturing method of the present invention is characterized by moisture curing (-
The cured product obtained has good physical properties, suppresses thickening during production to obtain a low-viscosity liquid-type urethane resin, and has excellent stability during storage.

In addition, by conducting the reaction in the presence of a plasticizer, it is possible to obtain a one-component urethane resin with a lower viscosity, and the content of the organic polyincyanate compound monomer in the reaction product is reduced, which is more preferable in terms of safety. This made it possible to obtain a one-component urethane resin.

The one-component urethane resin having incyanate groups obtained by the method of the present invention can be sprayed alone or by mixing with various solvents if necessary.

It can be easily applied with a brush, roll coater, flow coater, etc., and a cured film is obtained by moisture in the air. Therefore, it can be suitably used for coating waterproofing materials, base materials, anticorrosion coatings, and even breakage and shatterproof coatings for glass bottles, glass windows, and the like. The resulting coating has excellent physical properties, particularly good elongation. In addition, - corrugated urethane resin is not limited to use as a coating agent, but can be used in a wide range of other applications, such as as a modifier for asphalt and water-soluble resins, for molding sheets, and as an impregnating agent for porous materials such as textile products. I can do it. Since the one-component urethane resin obtained by the present invention has a low viscosity, a large amount of each lightning agent can be blended therein, and a cured product can be obtained at low cost.

Next, the present invention will be explained in more detail with reference to Examples.

Examples 1-9. Comparative Examples 1 to 5 Liquid polybutadiene and low molecular diol (O
H ratio (1:1) and a plasticizer (parts by weight) were charged into a reaction vessel, and dehydrated by heating at 70C for 1 hour under a reduced pressure of 1 Hg.

Next, a predetermined amount of an organic polyisocyanate compound is added.
After stirring for an hour, the temperature was raised to 80 t, and reaction was carried out under heating and stirring for 6 hours to obtain a liquid polyurethane resin. The properties of the obtained -liquid type polyurethane resin are shown in Table 1. In addition, the obtained -liquid type urethane resin was
Inject into the mold of the throat and 25C9 under the condition of 60% humidity for 14 days.
The mixture was air-cured for several days to obtain a cured sheet. The toughness of the obtained cured product sheet was determined according to JIS-63D1. The results are shown in Table 1.

Comparative Example 6 Hydroxyl group-containing liquid polybutadiene 92.4 used in the example
6 parts by weight of N,N-bis-2-hydroxyprobyl aniline, 52.4 parts by weight of dioctyl phthalate,
22.3 parts by weight of liquid modified MDI (NC010H=1.
05) and di-n-butyltin dilaure) (15
After casting the weight part according to the example, 120% at 120C
The mixture was cured under pressure for 15 minutes and cured at 70C for 15 hours to obtain a two-component urethane resin sheet. The physical properties of this sheet were measured as follows.

Tension 1 4. s
Ky/d Shin Hi 265
% tear 8.7K
y/cm hardness Shore A 46 JIS-D 11 ゑζ1 Number average molecular weight 2800. Viscosity 50 Voise 150
C.

Hydroxyl group content (1,79 meq/P, fine structure trans-1,460%, cis-1,420%.

Vinyl-1,220% *2. 1 - Hydroxyl group content α85 meq / y- *3 Molecular weight 209. Hydroxyl group content 257meq/P*4
Molecular weight: 394. Hydroxyl group content 5.08 meq/P
*5 NCO content 33,6 weight ratio *6 NGO content 2a8 weight ratio *7 Free NGO urethane hardens when it is 5 to 6 weight or less Patent applicant Idemitsu Kosan Co., Ltd.

Claims (1)

[Claims] 1) (A) liquid diene polymer containing active hydrogen groups, (B)
A method for producing a one-component urethane resin, which comprises reacting a low molecular weight polyol containing a hydroxyl group bonded to at least one secondary carbon and (C) an organic polyisocyanate compound. 2) (A) active hydrogen group-containing liquid diene polymer, (
B) A method for producing a one-component urethane resin, which comprises reacting a low molecular weight polyol containing a hydroxyl group bonded to at least one secondary carbon and (Q) an organic polyisocyanate compound in the presence of a fattening agent.