KR101630161B1 - Method for polymerization of elastic polyurethane having good thermal-stability and elastic polyurethane thereof - Google Patents

Abstract

The present invention relates to a process for polymerizing an elastomeric polyurethane which is capped using a mixture of a triazine based capping agent and a conventional capping agent, the terminal isocyanate groups of polyurethanes prepared by polymerizing a composition such as polyisocyanate, polyol and crosslinking agent. By using the triazine capping agent and the general capping agent in combination, it is possible to have excellent thermal stability without significantly changing the physical properties by giving no structural change.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic polyurethane polymer having excellent thermal stability and an elastic polyurethane polymer prepared therefrom,

The present invention relates to a method of polymerizing an elastic polyurethane, and more particularly, to a method of polymerizing an isocyanate group in a polyurethane by capping a terminal isocyanate group of a polyurethane prepared by polymerizing a polyisocyanate, a polyol and a crosslinking agent with a mixture of a triazine- , A method for polymerization of an elastic polyurethane having excellent thermal stability while maintaining storage stability, and an elastic polyurethane polymer produced therefrom.

Polyurethane was synthesized by Otto Bayer in the late 1930s and is a polymer compound widely used as an additive for adhesives, coatings and paints, and as a binder for inks and paints.

The polyurethanes are synthesized by the reaction of various reactants. The reactants include a polyol having two alcohol groups and a compound having two isocyanate groups, a chain extender having two alcohol groups or amine groups, or a crosslinking agent having three or more alcohol groups cross linkers, tin-based or amine-based catalysts, and capping agents that cap the isocyanate groups at both ends of the polyurethane resulting from the reaction of the polyol with the isocyanate compound.

Both ends of the alcohol group of the diluent or crosslinker react with an isocyanate functional group reacted with the polyol, respectively, to form a peptide bond. The result is hard segments composed of peptide bonds that connect soft segments and other soft segments composed of polyethers. The polyurethane having such a hard portion and soft portion is called a polyurethane elastomer.

The soft part thus formed has a non-polar nature and a glass transition temperature (T _g ) lower than room temperature. The hard part has a polarity property and has a glass transition temperature (T _g ) higher than room temperature, It has an important influence on the polymer behavior of urethane.

The role of the capping agent in the elastic polyurethane is to block the terminal isocyanate group of the polyurethane having good reactivity by blocking the reactivity to ensure the storage stability and to control the viscosity according to the viscosity of the capping agent added. Such capping agents are widely used such as alcohols such as phenol, maleic acid, amine and oxime. 2-allylphenol and 2- (n-penta-8'-decenyl) phenol are used in US Patent No. 7,557,169, and US Patent No. 5,278,257 discloses 3,3'-diallyl bisphenol A, 1,4 Dihydroxybenzene, 1,3-dihydroxybenzene, 1,2-dihydroxybenzene, naphthoresorcinol, dihydroxynaphthalene and the like are used.

The alcohol capping agent may be separated from -NCO at a high temperature (about 170 ° C.) and may provide hydrogen used as a catalyst in the hydroxyl group of the alcohol. If the capping agent has a low boiling point, it evaporates at a high temperature and the polyurethane- And the bonding strength is weakened. Thus, the production of polyurethanes using suitable capping agents has a significant effect on the performance of the polyurethane-applied adhesives or coatings.

U.S. Patent No. 7,557,169 U.S. Patent No. 5,278,257

In order to solve the above problems, it is an object of the present invention to provide an elastic polyurethane polymerization method which is excellent in thermal stability without significantly changing the physical properties of the polyurethane.

Specifically, the end isocyanate group of the polyurethane prepared by polymerizing a composition of polyisocyanate, polyol and crosslinking agent is capped by using a mixture of a triazine-based capping agent and a general capping agent to obtain an elastic polyurethane And to provide an elastic polyurethane polymer produced therefrom.

In order to accomplish the above object, the present invention relates to a process for producing a polyurethane foam comprising the steps of polymerizing a composition of a polyisocyanate, a polyol and a crosslinking agent, and a step of capping the terminal isocyanate group of the polyurethane prepared by adding a mixture of a triazine- And more particularly to a polymerization method of an elastic polyurethane having excellent stability.

Another aspect of the present invention relates to a method for polymerizing an elastic polyurethane in which the triazine-based capping agent has a structure represented by the following formula (1).

[Chemical Formula 1]

Wherein X ₁ and X ₂ are hydroxyl group or epoxy group, and X ₁ and X ₂ may be the same or different.

Another embodiment of the present invention relates to a method of polymerizing an elastic polyurethane wherein the mixture of the triazine based capping agent and the conventional capping agent is 5 to 40% by weight.

Another aspect of the present invention relates to a method of polymerizing an elastic polyurethane wherein the ratio of the triazine based capping agent to the conventional capping agent is from 1: 3 to 1: 8 by weight.

Another embodiment of the present invention relates to a method of polymerizing an elastic polyurethane having 5 to 20% by weight of a polyisocyanate, 50 to 80% by weight of a polyol and 0.1 to 2% by weight of a crosslinking agent in the composition.

Another aspect of the present invention relates to a method of polymerizing an elastic polyurethane wherein the polyol has a weight average molecular weight of 1,000 to 6,000 g / mol.

Another aspect of the present invention relates to a method of polymerizing an elastomeric polyurethane further comprising a catalyst and / or a chain extender in the composition.

Another aspect of the present invention relates to an elastomeric polyurethane polymer having excellent thermal stability by capping a terminal isocyanate group of the polyurethane using a triazine based capping agent.

Hereinafter, each component according to the present invention will be described.

The present invention relates to a method for polymerizing an elastic polyurethane having excellent thermal stability by polymerizing a composition of a polyisocyanate, a polyol and a crosslinking agent and adding a mixture of a triazine-based capping agent and a general capping agent to cap the terminal isocyanate group of the polyurethane.

The polyisocyanate is not particularly limited, but may be an aliphatic or cycloaliphatic group having an isocyanate group (-NCO) having a functionality of 2 or more, and preferably has a functionality of 2 to 5. For example, there can be mentioned 1,6-hexamethylene diisocyanate, 3,5,5-trimethyl-1-isocyano-3-isocyanatomethylcyclohexane, trimethylhexamethylene diisocyanate, methylene diphenyl diisocyanate, Isocyanate, 1,4-butylene diisocyanate, isophorone diisocyanate, bis (4,4'-isocyanatocyclohexyl) methane, 1,4-cyclohexylene diisocyanate, 4-isocyanatomethyl- 1,6-hexanediisocyanate, 1,8-octane diisocyanate or alkyl-2,6-diisocyanatohexanoate having an alkyl group having 1 to 8 carbon atoms. The polyisocyanate may be used singly or in combination of two or more, preferably 5 to 20% by weight.

Also, the polyisocyanate may be a mixture further containing a modified diisocyanate having a structure of uretdione, isocyanurate, urethane, allophanate, biuret, iminooxadiazine or oxadiazinetrione having a functionality of 2 or more .

The polyol is not particularly limited but may be, for example, a polymer polyol having a weight average molecular weight of 1,000 to 6,000 g / mol, for example, polyether diol, bisphenol A, bisphenol S, polypropylene glycol, polybutylene glycol, , Glycerol, erythritol, pentaerythritol, trimethylol benzene and trishydroxyethyl isocyanurate, polyester polyols, polyether polyols, polyacrylate polyols, polyurethane polyols, polycarbonate polyols, polyester polyacrylics A polyurethane polyacrylate polyol, a polyurethane polyester polyol, a polyurethane polyether polyol, a polyurethane polycarbonate polyol, and a polyester polycarbonate polyol. The polyol may be used singly or in combination of two or more, preferably 50 to 80% by weight.

The functionality of the hydroxyl group (-OH) in the polyol is preferably 2, but the present invention is not limited thereto.

Although the crosslinking agent is not particularly limited, trimethylolpropane, 4,4 ', 4 "- (1,3,5-triazine-2,4,6-triyl) triphenol, It is preferable to use it in weight%.

The present invention uses a mixture of a triazine-based capping agent and a conventional capping agent to obtain a thermostability that is superior to that of a conventional capping agent by controlling viscosity. The mixture of the capping agent is used in an amount of 5 to 40 wt% And is preferably added in a proportion of 1.01 to 3 equivalents of hydroxyl groups per equivalent of the terminal isocyanate group of the polyurethane. Within this range, excellent capping ability and excellent thermal stability are obtained.

The mixture of the triazine-based capping agent and the general capping agent is not particularly limited, but preferably has a weight ratio of 1: 3 to 1: 8. In this range, excellent thermal stability can be obtained while maintaining the physical properties of the polyurethane.

The triazine capping agent has a structure represented by the following general formula (1), X ₁ and X ₂ are hydroxyl groups or epoxy groups, and X ₁ and X ₂ may be the same or different.

[Chemical Formula 1]

Since the triazine capping agent is a thermally stable triazine derivative, the thermal stability of the entire polyurethane can be improved even when capping one or two of the various isonate groups.

As the above-mentioned general capping agent, any conventional capping agent can be used without any particular limitation, and examples thereof include alcohols, amine compounds, phenol, bisphenol A, bisphenol M, bisphenol F, 1,3-dihydroxybenzene, 1,4-dihydroxybenzene, 1,2-dihydroxybenzene, proroglucinol, resorcinol, naphthoresorcinol, phenolphthalein, o, o'-diallyl bisphenol A, Maleic anhydride, maleic anhydride, and the like.

The elastic polyurethane according to the present invention may further include any one or two or more additives selected from a catalyst and a chain extender if necessary.

The catalyst is not particularly limited as long as it is a catalyst ordinarily used in the art, and for example, any one or two or more selected from amine-based catalysts, organic titanium compound-based and organotin compound-based catalysts can be used, It is preferable to use dibutyl tin dilaurate or di-n-butylbis (dodecylthio) tin as an organotin compound catalyst.

The chain extender has at least one functional group selected from the group consisting of -NH ₂ and -NH _2. The chain extender is not particularly limited, but is preferably a diamine or a polyamine such as ethylenediamine, 1,2-diaminopropane, , 1,4-diaminobutane, 1,6-diaminohexane, isophoronediamine, isomer mixtures of 2,2,4- and 2,4,4-trimethylhexamethylenediamine, 2-methylpentamethylenediamine, di Ethylenetriamine, diaminodicyclohexylmethane, dimethylethylenediamine and the like can be used.

The polyurethane polymer according to the present invention has an advantage that a solvent is not required separately because the polyol melts at a high temperature of 80 to 95 캜.

The polyurethane according to the present invention may have a weight average molecular weight of 6,000 to 70,000 g / mol, a polydispersity index of 1.5 to 10, and a pyrolysis temperature of 250 to 500 ° C.

The elastic polyurethane according to the present invention can have excellent thermal stability without significantly changing its physical properties by using a triazine-based capping agent and a conventional capping agent as a capping agent to prevent structural changes.

FIG. 1 is a graph showing gel permeation chromatography (GPC) data of Examples and Comparative Examples. The graphs obtained through experiments were analyzed by using software to determine the number average molecular weight, the weight average molecular weight, the polydispersity index (PI), the weight average molecular weight / Molecular weight) can be obtained.
FIG. 2 shows TGA (Thermogravimetry Analysis) data of Examples and Comparative Examples, showing pyrolysis temperatures and residual amounts after pyrolysis.

Hereinafter, the method for polymerizing an elastic polyurethane according to the present invention and the elastic polyurethane polymer prepared therefrom will be described in more detail with reference to the following examples. It should be understood, however, that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

Unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In addition, the following drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the following drawings, but may be embodied in other forms, and the drawings presented below may be exaggerated in order to clarify the spirit of the present invention. Also, throughout the specification, like reference numerals designate like elements.

Also, the singular forms as used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The physical properties of the polyurethane prepared through the following Examples and Comparative Examples were measured as follows and shown in Table 1.

(Thermal decomposition temperature)

The pyrolysis temperature was measured using a thermogravimetric analyzer (TGA / SDT A851E, Mettler Toledo) at a heating rate of 10 ° C / min under a nitrogen atmosphere and at an initial 30% weight reduction temperature in a temperature range of 25 to 800 ° C.

(Polydispersity index)

The polydispersity index was measured by GPC instrument 1260 infinity (aqilent Tech.) Gel permeation chromatography and THF as a solvent.

(Average molecular weight)

The average molecular weight was measured by gel permeation chromatography (GPC) using 1260 infinity (aqilent Tech.) And THF as a solvent.

(Residual amount)

The residual amount was measured at a heating rate of 10 ° C./min and a temperature of 25 to 800 ° C. under nitrogen atmosphere by using a thermogravimetric analyzer (TGA / SDT A851E, Mettler Toledo) at an initial 30% weight reduction. The obtained data was analyzed using TA Instruments Universal Analysis 2000 software and the residual amount was calculated.

[Example]

80 g of polytetrahydrofuran (PolyTHF 2000) having a weight average molecular weight of 2,000 g / mol was placed in a three-necked flask, which was completely dissolved by heating at 82 ° C. Next, 0.6 g of trimethylolpropane was dispersed in 13 ml of hexamethylene diisocyanate (HMDI) and then mixed with polytetrahydrofuran. 0.8 μl of tin catalyst di-n-butylbis (dodecylthio) tin was added and reacted for 40 minutes. After the reaction, 5 g of 4,4 ', 4 "- (1,3,5-triazine-2,4,6-triyl) triphenol (HPT) and 32 g of bisphenol A were added to cap the isocyanate terminal group , And the mixture was reacted for 2 hours at a temperature of 110 DEG C. The reaction was then terminated by lowering the temperature to room temperature (20 DEG C) to obtain a liquid polyurethane having a high viscosity. The molecular weight, the weight average molecular weight, the polydispersity index, the thermal decomposition temperature and the residual amount were measured and are shown in Table 1 below.

[Comparative Example]

Except that pure bisphenol A alone was used as a capping agent in place of the HPT / bishpenol A mixture, to obtain a viscous liquid polyurethane having a high viscosity. The number average molecular weight, the weight average molecular weight, the polydispersity index, the thermal decomposition temperature and the residual amount of the prepared polyurethane were measured and described in Table 1 below.

Example Comparative Example Number average molecular weight
(g / mol) 15,000 12,900 Weight average molecular weight
(g / mol) 29,400 26,000 Polydispersity index 1.9 2.0 Thermal decomposition temperature (30% Loss)
(° C) 349.3 323.1 The residual amount (500 DEG C)
(%) 4.1 0.3

As shown in Table 1 and FIGS. 1 and 2, the polyurethane in the examples according to the present invention was mixed with a small amount of HPT as a capping agent and mixed with bishpenol A, which is a common capping agent, And the residual amount at 500 ° C is 4.1%, which is more than 0.3% of the comparative example. Thus, it is confirmed that the thermal stability at the time of fire can be more stable.

Claims (8)

Polymerizing a composition of a polyisocyanate, a polyol and a crosslinking agent; And
Capping the terminal isocyanate group of the polyurethane prepared by adding a mixture of a triazine capping agent and a common capping agent;
/ RTI >
The general capping agent may be an alcohol compound, an amine compound, phenol, bisphenol A, bisphenol M, bisphenol F, 1,3-dihydroxybenzene, 1,4-dihydroxybenzene, A method for polymerizing an elastic polyurethane having excellent heat stability, wherein the polyol is proglucrosinol, resorcinol, naphthoresorcinol, phenolphthalein, o, o'-diallyl bisphenol A, gallic ester, cresol novolak or maleic ester. The method according to claim 1,
Wherein the triazine capping agent has a structure represented by the following formula (1).
[Chemical Formula 1]

Wherein X ₁ and X ₂ are hydroxyl group or epoxy group, and X ₁ and X ₂ may be the same or different. The method according to claim 1,
Wherein the mixture of the triazine based capping agent and the general capping agent is 5 to 40% by weight based on the total weight of the composition of the polyisocyanate, the polyol and the crosslinking agent, and the mixture of the triazine-based capping agent and the general capping agent . The method of claim 3,
Wherein the ratio of the triazine capping agent to the general capping agent is from 1: 3 to 1: 8 by weight. The method according to claim 1,
The composition comprises 5 to 20% by weight of a polyisocyanate, 50 to 80% by weight of a polyol and 0.1 to 2% by weight of a crosslinking agent, based on the total weight of the composition of the polyisocyanate, the polyol and the crosslinking agent and the mixture of the triazine- A method for polymerizing an elastic polyurethane. 6. The method of claim 5,
Wherein the polyol has a weight average molecular weight of 1,000 to 6,000 g / mol. The method according to claim 1,
Wherein the composition further comprises a catalyst and / or a chain extender. delete

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