KR20060040034A - Distribution stabilizer for the preparation of polymer polyol - Google Patents

Abstract

The present invention relates to a novel dispersion stabilizer for producing polymer polyols wherein the polymer polyols of the present invention are used to produce improved polyurethane foams. The dispersion stabilizer is prepared by reacting monohydroxy alkyl acrylate and polyfunctional isocyanate with a polyether polyol having a functional group of 6 to 8 and a molecular weight of 3,000 to 15,000, wherein the polymer polyol derived therefrom has a low viscosity. Characteristics, and contribute to the improvement of physical properties of the final polyurethane.

Description

Dispersion stabilizer for producing polymer polyols {DISTRIBUTION STABILIZER FOR THE PREPARATION OF POLYMER POLYOL}

The present invention relates to dispersion stabilizers for producing polymer polyols, and more particularly to dispersion stabilizers for producing polymer polyols obtained by reacting polyols with polyfunctional isocyanates and hydroxy alkyl acrylates.

There are two main uses for polyurethane foams made from polymer polyols: soft slab stocks and soft molds. Slab stock is used in cushioning materials such as mattresses of furniture, furniture, and sofas, and the mold sector is used in various applications from seats to bumpers of automobiles. Polymeric polyols suitable for such polyurethane foams require high solids content and low viscosity properties.

Polymer polyol compositions are known materials and basic polymerization methods are known in detail in US Pat. Nos. 3,383,351 and 3,304,273. Such compositions polymerize one or more unsaturated monomers (eg, styrene, acrylonitrile, etc.) dissolved in a polyol by the free radical catalyst, and the polymer particles formed by the polymerization are stably dispersed in the polyol liquid phase. Polyurethane foams prepared using such polymer polyols have higher hardness and physical properties than conventional foams.

Initially commercialized polymer polyols were either acrylonitrile alone as the reaction monomer or were styrene-acrylonitrile mixed monomers having a low styrene content. The polymer polyol obtained by polymerizing such a monomer has a high self-viscosity, a yellowish color, and a scouring phenomenon occurs in the polyurethane foam which is the final product, and its use is limited. In order to minimize the scouring of the polyurethane foam, a method of increasing the styrene content to 65-70% has been proposed. However, as the styrene content increases, the stability of the polymer polyol greatly decreases and the viscosity increases rapidly.

U.S. Patent No. 4,208,314 describes low viscosity polymer polyols made from styrene / acrylonitrile mixtures. The patent describes that the polymer polyols produced have a relatively high styrene content and are capable of producing polyurethane foams with reduced scouring phenomena. U.S. Patent No. 4,148,314 also describes a process for producing polymer polyols with high dispersion stability and filterability by adding small amounts of polymer polyols pre-polymerized to the polymer polyol polymerization reaction.

In order to produce polyurethanes of further improved physical properties, efforts have been made to improve polymer polyols. In particular, in order to prepare low viscosity polymer polyols having a high content of polymer solids and stable polymer dispersion, a method of introducing a special ingredient called NAD (Non Aqueous Dispersant) stabilizer has been proposed. The NAD stabilizer introduces a small amount of unsaturation into the polyol in order to increase the dispersion stability of the produced solid content. US Patent Nos. 3,652,639, 3,823,201 and 3,850,861, British Patent 1,126,025, and Japanese Patent 52-80919, 48-101494. In addition, the literature (“Dispersion Polymerization in Organic Media”, edited by K.E.J. Barrett, John Wiley Sons, Copyright 1975) describes methods of using stabilizers during polymerization.

Relatively recent patents include US Pat. Nos. 4,454,255 and 4,458,038, which use polyols as stabilizers by reacting polyols with compounds having reactive unsaturations such as maleic anhydride or fumaric acid. In addition, US Patent No. 4,460,715 stabilizers were prepared by applying acrylate or methacrylate as a reactive unsaturated material.

U.S. Patent No. 4,550,194 discloses a polyol with an OH functional group, pentaerythritol, as an initiator, reacted with a group of maleic anhydride based on calcium naphthenate or cobalt naphthenate, and the resulting carboxylic acid structure is ethylene oxide or propylene oxide. A stabilizer is prepared by a method of reacting with an alkylene oxide such as. In a similar example, U.S. Patent No. 4,997,857 describes the process of reacting alkylene oxide after introducing unsaturation with maleic anhydride, but the polyol of the stabilizer is a polyol having a high molecular weight of at least OH functional tetravalent (Example: Sorbitol use). In addition, another example of a reactant that induces unsaturation in polyols to synthesize stabilizers is “TMI” (1- (t-butyl-isocyanato) -3-isopropenylbenzene) US Pat. No. 5,494,957, 4,954,561, 4,954,560 and 5,093,412 and the like, and US Pat. No. 4,390,645 describes stabilizers made from 2-isocyanatoethylmethacrylate.

The method of preparing a stabilizer using maleic anhydride causes a problem that the reaction time of the alkylene oxide, which is a post-process, is 15 to 32 hours, resulting in a long process time, and “TMI” (1- (t-butyl-isocyane). Special reactive unsaturated isocyanates such as iso) -3-isopropenylbenzene) and 2-isocyanato ethyl methacrylate are themselves very expensive compounds. Therefore, efforts have been made to minimize the amount of stabilizer required to prepare polymer polyols.

US Pat. Nos. 4,954,561 and 5,494,957 disclose methods for increasing the degree of steric stabilization of a stabilizer by increasing the size of the polyol portion of the stabilizer molecule via a coupling reaction. The coupling reaction is carried out by coupling a polyol using oxalic acid forming an oxalate diester in US Pat. No. 4,954,561, and in US Pat. No. 5,494,957 coupling of the stabilizer is carried out by reaction with diisocyanates. Is done. However, this coupling process requires a separate reaction process and causes an increase in raw material costs and process costs.

Thus, without the need for separate processes such as couplings, dispersion stabilizers that can be manufactured in a relatively short process time can provide improved physical properties such as dispersion stability, filterability, and low viscosity to polymer polyols in smaller amounts. The demand for it has continued.

 It is an object of the present invention to provide a dispersion stabilizer for the production of novel polymer polyols.

Another object of the present invention is to provide a dispersion stabilizer for preparing polymer polyols which can be produced in a short process time, but which can provide improved physical properties such as dispersion stability, filterability, low viscosity and the like in a smaller amount.

Still another object of the present invention is to provide a method for preparing a dispersion stabilizer for producing the polymer polyol.

Another object of the present invention is to provide a polymer polyol having a high solids content and low viscosity properties using the stabilizer.

Still another object of the present invention is to provide a polyurethane foam having higher hardness and physical properties by using the polymer polyol.

The novel dispersion stabilizer for producing the polymer polyol of the present invention for achieving the above object is prepared by reacting a polyol having an average OH functional group of 6 to 8 and an average molecular weight of 3,000 to 15,000 with a polyfunctional isocyanate and hydroxy alkyl acrylate.

In this invention, it is a polyether polyol used in order to manufacture the said dispersion stabilizer for polymer polyol manufacture, The average functional group of the said polyether polyol is 6-8, and is a polyol with an average molecular weight of 3,000-15,000.

The polyether polyol used in the present invention is obtained by reacting an alkylene oxide with a polyhydric alcohol or a combination thereof to obtain a polyol having an average functional group of 6.0 to 8.0 and an average molecular weight of 3,000 to 15,000. In order to obtain a polyol having an average functional group and a molecular weight in the above range, the polyhydric alcohol may be used alone or in combination with a polyhydric alcohol having an OH functional group in the range of 6.0 to 8.0, or in combination with a polyhydric alcohol having a lower OH functional group than the above range. have. In a preferred embodiment of the invention, the polyhydric alcohol may be appropriately selected from sugar, sorbitol, pentaeratritol, trimethylolpropane, glycerin, ethylene glycol and the like. The alkylene oxide reacting with the polyhydric alcohol may be selected from ethylene oxide, propylene oxide, butylene oxide, amylene oxide or mixtures thereof and the like, and may be appropriately selected depending on the properties of the final polyurethane foam. Preferably a mixture of ethylene oxide and propylene oxide is preferred.

When the polyol having an average functional group is lower than the above range, the steric hindrance of the dispersion stabilizer is reduced, and the viscosity of the polymer polyol becomes high. When the polyol having an average functional group larger than the above range is used, there is a problem in that the viscosity of the prepared stabilizer is increased, and there is a problem that the raw material is expensive.

In addition, when a polyol having an average molecular weight lower than the above range is used, the steric hindrance of the dispersion stabilizer is reduced, and the viscosity of the polymer polyol is increased. When the polyol having an average molecular weight larger than the above range is used, there is a problem in that the viscosity of the prepared stabilizer is increased, and there is a problem that the raw material is expensive.

In the present invention, the polyether polyol having an average functional group of 6.0 to 8.0 and an average molecular weight of 3,000 to 15,000 is reacted with polyfunctional isocyanate and hydroxy alkylacrylate to introduce an unsaturated group.

In the present invention, the polyfunctional isocyanate is 2,4-toluene diisocyanate, and toluene diisocyanate (TDI) such as 2,6-toluene diisocyanate, methylene diphenyl diiso cyanate (MDI), hexamethylene diisocyanate ( HDI), isophorone diisocyanate, naphthalene diisocyanate and the like. In a preferred embodiment, the polyfunctional isocyanate is a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate and is commercially available.

In the present invention, hydroxy alkyl acrylates include hydroxy ethyl acrylate (HEA), hydroxy propyl acrylate (HPA), hydroxy ethyl methacrylate (HEMA), hydroxy butyl acrylate (HBA) and their Mixtures and the like, and are preferably hydroxy propyl acrylate.

In the practice of the present invention, it is preferable to use 0.5 to 1.5 parts by weight of hydroxy alkyl acrylate based on 100 parts by weight of polyol, and 1 to 3 parts by weight of polyfunctional isocyanate based on 100 parts by weight of polyol.

In the practice of the present invention, the reaction of polyols with polyfunctional isocyanates and hydroxy alkylacrylates can be effected by heating in the presence or absence of a catalyst. In one preferred embodiment of the invention, the catalyst is octosan first tin.

In another aspect of the present invention, polymer polyols having high solids content and low viscosity properties are provided by polymerizing polymer polyols using the stabilizer. In a preferred embodiment of the invention, the preparation of the polymer polyol is made by a process of radically polymerizing unsaturated monomers in the polyol. Unsaturated monomers that can be used are styrene, methyl styrene, ethyl styrene, acrylonitrile, metaacrylonitrile, methyl methacrylate and acrylate, and the like, and a combination of styrene and acrylonitrile is preferred, and the amount of monomer added It is preferably about 20 to 60% by weight of the polymer polyol product, and when styrene / acrylonitrile combination is used, it is preferably used at a ratio of 0/100 to 80/20 by weight ratio.

Initiators of radical polymerization generally include organic peroxides such as benzoyl peroxide and butyl octoate, or azos such as azobisisobutylonitrile (AIBN) and azobismethylbutylonitrile (AMBN). Application is possible. The amount of the initiator added is about 0.2 to 2% based on the product, and as the amount added in a certain range increases, the polymerization rate and dispersion stability are increased.

Polyols used in the production of polymer polyols are polyhydric alcohols such as ethylene glycol, glycerin, trimethylol propane, pentaerythritol, sorbitol, sugar, or amines such as triethanol amine, ethylene diamine, toluene diamine, and ethylene oxide, propylene oxide, butyl Examples of polyols used in polyurethane production include addition polymerization of alkylene oxides such as ethylene oxide.

Molecular weight regulators can be used to prepare polymer polyols. For example, alcohols such as methanol, ethanol, isopropanol and butanol, methanes such as ethanethiol, heptane thiol, octane thiol and dodecane thiol, and toluene, ethyl benzene and xylene Etc. may be used and preferred are isopropanol, xylene, ethyl benzene, dodecane thiol and the like.

In the polymer polyol manufacturing process of the present invention, the whole raw material is mixed quantitatively and continuously introduced into the reactor, and a portion of the raw material is filled in the reactor and the continuous process and the reactor are transferred to the degassing process after a certain time, and the monomer, Both batch processes in which a mixture of initiator and raw material are added are possible. Polymerization temperature of a monomer is possible at 80-140 degreeC, and 100-130 degreeC area | region is especially preferable. After the polymerization is completed, degassing is carried out to remove unreacted monomers and other additives.

The polymer polyols according to the invention are very suitable for the production of polyurethane foams which are prepared by reacting with isocyanates in the presence of suitable polyurethane catalysts, blowing agents and crosslinking agents. The present invention therefore relates to polyurethane foams which can be prepared by reaction with polymeric polyols and isocyanates as mentioned above.

Polyurethane catalysts are well known and include many other compounds. Examples of commercially available catalysts are sold under the trade names NIAX, DABCO, TEGOAMIN, and the like. Specifically, for example, metal catalysts such as stannous octosan, stannous oleate, dibutyltin dilaurate, dibutyltin diacetate and trimethyl Amine catalysts such as amine, triethylamine, triethylenediamine (TEDA), dimethylethanolamine and bis (2,2-dimethylamino) ethyl ether. The catalyst is generally used in an amount of 0.1 to 3.0 parts by weight relative to the polyol.

The use of crosslinking agents is also important in the preparation of polyurethane foams, the most commonly used examples being glycerin and diethanol amines, when used, up to 3 parts by weight or from 0.2 to 1.5 parts by weight.

Suitable blowing agents are water, acetone, carbon dioxide, halogenated hydrocarbons, aliphatic alkanes and cyclo alkanes. The use of water as blowing agent reacts with isocyanates to produce carbon dioxide, which acts as blowing agent, as is well known. Aliphatic and cycloalkanes have been developed as alternative blowing agents for CFC compounds. Examples of such alkanes are pentane, hexane and cyclopentane, cyclohexane and the like. The blowing agents are used alone or in a mixture of two or more. The amount of blowing agent used is about 0.1 to 5 parts by weight for water, and the amount of other blowing agents is used in an amount of about 1 to 20 parts by weight. Other additives may also be flame retardants, surfactants and fillers.

EXAMPLES The following examples illustrate the invention, but the following examples should not be construed as limiting the invention. Those skilled in the art will also appreciate that variations of the invention are possible without departing from the scope and spirit of the invention as set forth in the claims.

Example

In the present invention, the compounds, symbols, and concepts used in the stabilizer synthesis and the polymer polyol polymerization are as follows.

Polyol A: A polyol obtained by reacting propylene oxide and ethylene oxide with a mixed initiator of sugar and glycerin. OH. Value: 28.5, average functional group: 7, average molecular weight: 13,800, viscosity: 2,000 cps / 25 ° C.

Polyol B: A polyol obtained by reacting a glycerine initiator with propylene oxide and ethylene oxide. OH. Value: 34, molecular weight: 4,950, viscosity: 750 cps / 25 ° C.

Polyol C: Polyol obtained by reacting propylene oxide alone with a glycerin initiator

         OH. Value: 56, molecular weight: 3,000, viscosity: 450 cps / 25 ° C.

Polyol D: A polyol obtained by reacting a glycerine initiator with propylene oxide and ethylene oxide. OH. Value: 56, molecular weight: 3,000, viscosity: 410 cps / 25 ° C.

HPA: 2-Hydroxy propyl acrylate

T-9: octosan first tin

T-80: A mixture of 80:20 weight ratio of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate (Toyo Chemical)

SM: Styrene Monomer

AN: Acrylonitrile

AIBN: Azo bis isobutyronitrile

EB: Ethyl Benzene

n-DDM: n-Dodecyl mercaptane

OH. Is the value of the equivalent of OH group in grams of polyol converted into mg of KOH (esterified with excess phthalic anhydride / pyridine solution and titrated with residual phthalic anhydride with KOH solution) Method of ASTM D 4274-94 Measured accordingly.)

Viscosity: Brookfield Viscometer (Model DV-II + Viscometer), Unit: cps / 25 ℃

Example 1 (Stabilizer Synthesis SB.1)

T-80 (34.4 g, 0.2 mol) was added to the reactor and the temperature was raised to 80 ° C. under stirring in a nitrogen atmosphere. HPA (26g, 0.2mol) was added while maintaining 80 ° C and 80 ° C was maintained under stirring for 1 hour. Polyol A (2,760g, 0.2mol) was added to another reactor and heated up to 70 degreeC in nitrogen atmosphere. Add the T-80 / HPA reactant (60.4 g, 0.2 mol) above with stirring while maintaining the temperature. T-9 (0.56g, 200ppm total weight) is added and aged for 2 hours. The viscosity of the resultant is 3,200cps / 25 ℃, unsaturation 0.035 meq / g.

Examples 2 to 10 (SB, 2 to 10)

A stabilizer was prepared in the same manner as in Example 1, but as shown in Table 1, the stabilizer was prepared by varying the weight ratio, the amount of T-9 added, and the aging time during the reaction of T-80 with HPA and polyol A.

TABLE 1 Stabilizer Synthesis Examples 1-10

Comparative Example 1 (Stabilizer Synthesis, Stabilizer.E)

As a comparative example with the present invention a stabilizer was prepared in the same manner as in Example 51 of US Pat. No. 4,550,194.

A polyol having an OH. 28 is prepared by reacting pentaerythritol with an OH functional tetravalent with propylene oxide and ethylene oxide (15 wt%). The polyol is reacted with maleic anhydride (1% by weight ratio of polyol) with a calcium naphthenate (200 ppm) catalyst and continuously reacts ethylene oxide (10.9 mol with respect to polyol) at 125 ° C. (reaction time 9 hours). The temperature was lowered to 105 ° C. and degassed for 1 hour in a vacuum of 10 mmHg to remove unreacted ethylene oxide. Viscosity: 2,400cps / 25 ℃

Example 11 (Polymer Polyol Polymerization, CPP.11)

The 3-liter reactor was equipped with a condenser and a stirrer, put 180g of polyol D and 180g of EB, and heated up to 120 degreeC under nitrogen atmosphere. The monomer mixture <Polyol D 846g, SM 360g, AN 360g, AIBN 10.8g, Stabilizer (SB.1) 72g> prepared in advance while maintaining between 115-125 degreeC under stirring is continuously added over 2 hours. Let aging for 30 minutes after the end. The temperature was raised to 125 ° C. and degassed in a vacuum of 5 mmHg for 3 hours to remove unreacted monomers and EB. Solid content: 40%, Viscosity: 6,200 cps / 25 ° C

Examples 12-19 (polymer polyol polymerization, CPP. 12-23)

A polymer polyol was prepared in the same manner as in Example 11, except that the polymer according to the polyol type (polyol B or D) and the addition amount, the amount and ratio of SM and AN, and the use of EB or n-DDM, as shown in Table 2 below. Polyols were prepared. Component ratios of Table 2 are expressed in PBW (part by weight, weight ratio). Example 19 was a polymerization without adding a stabilizer, and the viscosity of the reaction solution rapidly increased in the middle of the reaction to a state in which stirring was impossible, and the reaction was stopped before all the monomer mixture was added.

Comparative Examples 2 and 3

A polymer polyol was prepared in the same manner as in Examples 11 and 19 using the stabilizer E synthesized in Comparative Example 1 as a comparative example with the present invention. The polymer polyols of Comparative Examples 2 and 3 showed higher viscosity values as compared to the polymer polyol of the present invention as shown in Table 2 below.

TABLE 2 Polymer Polyol Polymerization Examples 11-23, Comparative Example 2. 3

Examples 20-23 (polyurethane foam production)

A polymer polyol, a polyol, a silicon foam stabilizer (L-580k), an amine catalyst (A-1), and water are stirred and mixed at the ratio shown in Table 3 below, and the liquid temperature is adjusted to 25 ° C. MC (methylene chloride, Methylene Chloride) and T-9 was added to the mixed solution at 25 ° C. and mixed by stirring at 6,000 rpm for 10 seconds. Add T-80, stir for 6 seconds at 6,000 rpm, mix and inject into a 20 * 20 * 20cm ³ mold. After 15 minutes demoulded and after 24 hours the mechanical properties of the foam were measured. Each mechanical property was measured by the method of ASTM D-3574. The measurement results are shown in Table 4.

Comparative Example 4

The polymer polyol of Comparative Example 3 was prepared in the ratio shown in Table 3, which is the same formula as in Examples 20 to 23, to prepare polyurethane foam, and the physical properties thereof were compared, and the results are shown in Table 4. The polymer polyol of Comparative Example 3 had a high self-viscosity and a general decrease in physical properties compared to the polymer polyol of the present invention.

According to the present invention, a polyol having high steric hindrance with an average functional group of 6 to 8 and an average molecular weight of 3,000 to 15,000 is reacted with a polyfunctional isocyanate and a hydroxy alkyl acrylate to stabilize the polymer polyol and to prepare it economically in a short production time. A method was provided. In addition, the dispersion stabilizer was used in the preparation of the polymer polyol, thereby providing a polyol having a high solid content and a low viscosity. In addition, by using the polymer polyol, it was possible to improve the physical properties of the final polyurethane foam.

Claims (9)

A dispersion stabilizer for producing a polymer polyol, wherein a polyether polyol having an average molecular weight of 3,000 to 15,000 and an average functional group of 6 to 8 is prepared by reacting polyfunctional isocyanate and hydroxy alkyl acrylate. The dispersion stabilizer according to claim 1, wherein the polyether polyol uses sugar or a polyhydric alcohol containing sugar as an initiator. The stabilizer of claim 1, wherein the polyfunctional isocyanate is an alkylene oxide selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide, amylene oxide or mixtures thereof. 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, methylene diphenyl diiso cyanate (MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate, naphthalene diisocyanate and A stabilizer for producing a polymer polyol, wherein the polyfunctional isocyanate selected from the group consisting of a mixture thereof is used in an amount of 1 to 3 parts by weight based on 100 parts by weight of the polyether polyol. 2. A group according to claim 1 wherein hydroxy ethyl acrylate (HEA), hydroxy propyl acrylate (HPA), hydroxy ethyl methacrylate (HEMA), hydroxy butyl acrylate (HBA) and mixtures thereof A stabilizer for producing a polymer polyol, wherein 0.5 to 1.5 parts by weight of the selected hydroxy alkyl acrylate is used based on 100 parts by weight of the polyether polyol. A polymer polyol prepared by polymerizing at least one ethylenically unsaturated monomer in a polyol comprising the dispersion stabilizer of claim 1 with a radical polymerization initiator. The polymer polyol of claim 6, wherein the radical polymerization initiator is an azo compound. The polymer polyol of claim 6, further comprising a molecular weight modifier selected from the group consisting of n-DDM, EB, or mixtures thereof. A method for producing a flexible polyurethane foam prepared by reacting the polymer polyol of Claims 6-8 with an isocyanate compound in the presence of a blowing agent and a catalyst.