KR20060040264A - Dispersion Stabilizers for Polymer Polyol Production - Google Patents

Abstract

The present invention relates to dispersion stabilizers for the production of polymer polyols, wherein the polymer polyols are used to produce improved polyurethane foams. The stabilizer is prepared by reacting a polyol having an average functional group of 4.5 to 8.0 and a molecular weight of 5,000 to 15,000 with vinyltrialkoxy silane, and the polymer polyol prepared using the polymer has a low viscosity and improves physical properties of the final polyurethane. Contribute to .

Description

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

The present invention relates to a dispersion stabilizer for producing polymer polyol, and more particularly, to a stabilizer for producing polymer polyol obtained through the reaction of a polyol having a molecular weight of 5,000 to 15,000 and a molecular weight of 5,000 to 15,000 with vinyl triethoxysilane. .

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 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. NAD tablets introduce a small amount of unsaturation into the polyols in order to enhance the dispersion stability of the resulting solids.

US Pat. Nos. 4,454,255 and 4,458,038 disclose methods for reacting polyols with compounds having reactive unsaturations, such as maleic anhydride or fumaric acid, and using them as stabilizers. US Pat. No. 4,460,715 also discloses acrylates or methacrylates. The stabilizer was prepared by applying such as a reactive unsaturated.

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.

  EP 0 162 589 describes a method for preparing a non-aqueous dispersion stabilizer by reacting a polyetherpolyol having an average molecular weight of 3000 to 5000 and a functional group of 3 with vinyltrialkoxy silane. In US Pat. No. 5,990,185, a polyol of a dispersion stabilizer is prepared by first applying a precursor stabilizer by applying a polyol having a high molecular weight of at least OH functional group (e.g., an initiator of the polyol using sorbitol of a OH functional group hexavalent group). A dispersion stabilizer prepared by polymerizing a small amount (polymer content of 5 to 10% by weight) of an unsaturated monomer mixture is described. US Pat. No. 4,871,735 describes a dispersion stabilizer prepared by reacting a compound such as thiolpropyl trimethoxysilane having a thiol group with a polyether polyol having 3 functional groups and an average molecular weight of about 4000.

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 the 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 dispersion stabilizer for producing a novel polymer polyol of the present invention for achieving the above object is prepared by reacting a vinyltrialkoxysilane on a polyol having an average functional group of 4.5 to 8.0 and an average molecular weight of 5,000 to 15,000.

In the present invention, the polyol used to prepare the dispersion stabilizer for producing the polymer polyol is a polyether polyol, the average functional group of the polyether polyol is 4.5-8, and the average molecular weight is 5,000-15,000.

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 a functional group of 4.5 to 8.0 and an average molecular weight of 5,000 to 15,000. In order to obtain a polyol having an average functional group of 4.5 to 8.0 and a molecular weight of 5,000 to 15,000, the polyhydric alcohol may use ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, sugar, and mixtures thereof, preferably The OH functionality is sugar, a mixture of sugar and glycerin, sorbitol, or a sugar / pentaerthritol mixture. The alkylene oxide reacting with the polyhydric alcohol may be selected from ethylene oxide, propylene oxide, mixtures thereof, and the like, and may be appropriately selected depending on the properties of the final polyurethane foam. Preferably, it is a mixture of ethylene oxide and propylene oxide.

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. If the average molecular weight of the polyol is larger than the above range, there is a problem 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 4.5 to 8 and an average molecular weight of 5,000 to 15,000 can react with a silicone compound having a group capable of reacting with a hydroxyl group of the polyol in order to introduce an unsaturated group. . Preferred silicone compounds consist of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxy silane and mixtures thereof.

In another aspect of the present invention, the present invention provides a polymer polyol exhibiting high solids and low viscosity properties obtained by radical polymerization of unsaturated monomers in a polyol using the dispersion stabilizer.

In the practice of the present invention, examples of the polyols usable for the polymerization of the polymer polyols include polyether polyols, poly hydroxyl containing polyester polyols, polyhydroxyl terminated polyurethane polymers, polyvalent polythioethers, and polytetrahydrofuran have. Preferred polyols are polyether polyols. Types of initiator that can be used are ethylene glycol, glycerin, trimethylol propane, pentaeratritol, sorbitol, sugar and the like.

Suitable ethylenically unsaturated monomers for preparing polymer polyols include styrene, acrylonitrile, alpha-methyl styrene and the like. Preferred ethylenically unsaturated monomers are mixtures of styrene and acrylonitrile with a molar ratio of 20:80 to 80:20. The amount of ethylenically unsaturated monomers used is in the range of 30 to 60% by weight, preferably 30 to 50, based on the total weight. Amount%.

Polymerization of the monomers is carried out by free radical polymerization initiators. Such initiators are typically used in amounts of 0.01 to 1% by weight relative to the total weight of the monomers. Suitable polymerization initiators include peroxide compounds and azo compounds.

Chain transfer agents may also be added to the polymerization medium in small amounts or present in the medium. Chain transfer agents enable the control of crosslinking that occurs between various polymer molecules and can affect the stability of the polymer polyol. The chain transfer agent is suitably used in an amount of 0.1 to 6% by weight, preferably 0.2 to 5% by weight relative to the total weight of the reactants. Examples of suitable chain transfer agents include 1-butanol, 2-butanol, isopropanol, ethanol, methanol, water, cyclohexane and mercaptans such as dodecanethiol, ethanethiol, 1-heptaneol, 2-octanethiol and toluene thiol , Toluene, ethylbenzene and the like.

The polymer polyols of the present invention are also 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.

Examples of polyfunctional organic isocyanates used in the production of polyurethane foams include toluene diisocyanates, especially 2,4- and 2,6-toluene diisocyanate (TDI) and optional mixtures of these isomers; 2,4- and 4,4-diphenylmethane diisocyanate (MDI) and optional mixtures thereof; Oligomers of MDI (polymerizable MDI); and mixtures of TDI and polymerizable MDI. Preferred isocyanates are 80/20 TDI (mixture of 80% 2,4-toluene diisocyanate with 20% 2,6-toluene diisocyanate).

Any blowing agent conventionally used in the production of polyurethane foams can be used. Examples of suitable blowing agents are water, acetone, carbon dioxide, halogenated hydrocarbons, aliphatic alkanes and cyclo alkanes. The use of water as a blowing agent reacts with isocyanates to produce carbon dioxide which acts as a blowing agent. Aliphatic alkanes and cyclo alkanes have been developed as alternative blowing agents for CFC compounds. Examples of such compounds are pentane, hexane, 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 pbw (weight ratio) for water and about 1 to 20 pbw for other blowing agents.

Any reaction catalyst used in polyurethane foam can be used, examples of which are tertiary amines and organometallic compounds. The catalyst is generally used in about 0.1 to 3 pbw compared to the polyol.

Any stabilizer or cell stability or other cell size controlling surfactant used in the preparation of the polyurethane foam can be used. Examples of suitable surfactants are block copolymers of various silicone surfactants, preferably polysiloxanes and polyoxyalkylenes.

Crosslinking agents can also be used to improve the properties of the polyurethane foam. The most common examples are glycerin and diethanol amines, with 3 pbw or less or 0.2 to 1.5 pbw used.

In addition to the additives mentioned above, various various additives used in the production of polyurethane foams can be used, such as flame retardants, antifoams, antioxidants, mold release agents, dyes, pigments and other fillers.

The following examples are given for illustration of the invention. However, the following examples should not be construed as limiting the invention, but only as illustrative. Those skilled in the art will understand that modifications can be made without departing from the scope and spirit of the invention.

 EXAMPLE

The following naming, symbols, terms and subscripts are used in the examples below.

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

Polyol B: polyol obtained by reacting sorbitol initiator with propylene oxide and ethylene oxide, OH. Value: 42, molecular weight: 8,000, viscosity: 1,300 cps / 25 ^o C

Polyol C: A polyol obtained by reacting a glycerine initiator with propylene oxide and ethylene oxide, OH. Value: 56, molecular weight: 3,000, viscosity: 450 cps / 25 ^o C

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

Polyol E: polyol obtained by reacting propylene oxide alone with a glycerin initiator, OH. Value: 56, molecular weight: 3,000, viscosity: 450 cps / 25 ^o C

VTMS: Vinyl Trimethoxy Silane

VTES: Vinyl Triethoxy Silane

Vazo-67: 2,2'-azobis (2-methylbutanenitrile) polymerization catalyst [manufactured by E. J. du Pont de Nemours and Co.]

SM: Styrene

AN: Acrylonitrile

EB: ethylbenzene

Measurements were made according to the following test methods to test the properties of the polymer polyols set forth in the Examples below.

OH. Is the value of the equivalent of OH group in grams of polyol in terms of mg of KOH (esterified with excess phthalic anhydride / pyridine solution and titrated with phthalic anhydride as KOH solution. ASTM D 4274-94 Measured according to the method)

Viscosity: measured using a Brookfield Viscometer, Spindle # LVVT3, Speed 12 according to ASTM D-4874

Example 1 (Dispersion Stabilizer Synthesis SC. 1)

Into a 2-liter reactor equipped with a stirrer, a thermometer and a condenser, 1,000 g of polyol A was introduced. Remove water at 100 ^o C for 30 minutes and then cool down to 60 ^o C. To this was added VTMS (16.6 g, 0.112 mol). Raise the reaction temperature to 140 ^o C. After the reaction for 8 hours in a nitrogen atmosphere it is cooled to room temperature. The dispersion stabilizer obtained was colorless and had a viscosity of 3,200 cps at 25 ^° C. Unsaturation is 0.169.

Examples 2 to 10 (SC. 2 to 10)

To prepare a dispersion stabilizer in the same manner as in Example 1. As shown in Table 1, dispersion stabilizers were prepared by varying the types and amounts of polyols, VTMS, and VTES.

TABLE 1 Dispersion Stabilizer Synthesis Examples 1-10

Comparative Example 1 (dispersion stabilizer synthesis)

In a comparative example with the present invention, a dispersion stabilizer was prepared in the same manner as in Example 3 of US Pat. No. 4,723,026.

798 g (0.170 mol) of a polyol having an OH functional group of 3 and a molecular weight of 5,000 are charged to a 1 liter reactor equipped with a stirrer, a thermometer and a condenser. Remove water at 100 ^o C for 30 minutes and then cool down to 60 ^o C. To this was added VTMS (16.6 g, 0.112 mol). Raise the reaction temperature to 140 ^o C. After the reaction for 8 hours in a nitrogen atmosphere it is cooled to room temperature. The dispersion stabilizer obtained was colorless and had a viscosity of 840 cps at 20 ^° C. Unsaturation is 0.186.

Example 11 Preparation of Polymer Polyols (POP 11)

Polyol (180g) and EB (180g) are charged to a four-liter reactor with a capacity of 3 liters with a stirrer, condenser, thermometer, and addition tube. Polyol D was used as the polyol. Separately, SM (360g), AN (360g), the remaining polyol D (846g), dispersion stabilizer (SC. 2, 72g), Vazo-67 (10.8g) were mixed to prepare an injection composition. The reactor feed is heated to 120 ^° C. and then the feed is added to the reactor for 5 hours continuously while maintaining 115 to 125 ^° C. Once the addition is complete, it is maintained for 0.5 to 1 hour and then unreacted monomer and EB are removed for 5 hours at <5 mmHg and 120 ^° C. Solid content: 40%, Viscosity: 6,000 cps / 25 ^o C

Examples 12-19 polymer polyol polymerization (POP 12-19)

In the same manner as in Example 11, the polyol type (polyols C and D) and amount set as illustrated in the following [Table 2], the amount and ratio of SM and AN, the type and amount of dispersion stabilizer, and the amount of EB added According to the polymer polyol. Component ratios of Table 2 are expressed as pbw (part by weight, weight ratio).

Comparative Examples 2 and 3: Polymer Polyol Synthesis

According to the same method as in Example 11, the polymer according to the polyol type (polyols C and D) and the amount, the amount and ratio of SM and AN, the amount of dispersion stabilizer, and the amount of EB added were set as illustrated in Table 2 below. Polyols were prepared. The dispersion stabilizer used Comparative Example 1.

TABLE 2 Preparation Examples of Polymer Polyols 11-20, Comparative Examples 2,3

Examples 21-25

The polymer polyol, polyol, silicone foam stabilizer (L-580k), amine catalyst (A-1), and water are stirred and mixed at the ratio shown in the following [Table 3], and the temperature of the mixed liquid is adjusted to 25 ^° C. MC (methylene chloride, Methylene Chloride) and T-9 catalyst was added to the mixed solution, followed by stirring for 10 seconds to mix. Then add T-80, stir at 6,000 rpm for 6 seconds, mix and inject into a 20x20x20cm 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 measured results are shown in [Table 4].

Comparative Example 4

A polymer polyol prepared in Comparative Example 3 was used in the same manner as in Example, but using polymer polyol.

TABLE 3

[Table 4] Mechanical Properties of Polyurethane Foam

According to the present invention, a dispersion stabilizer for producing a polymer polyol and a method for economically preparing the polymer polyol are provided by reacting a polyol having a high steric hindrance with an average functional group of 4.7 to 8 and an average molecular weight of 5,000 to 15,000 with a vinyltrialkoxy silane. In addition, the dispersion stabilizer was used in the preparation of the polymer polyol, thereby providing a polymer 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 prepared by reacting a polytrial polyol having an average molecular weight of 5,000 to 15,000 and an average functional group of 4.5 to 8 with a vinyl trialkoxy silane. The dispersion stabilizer according to claim 1, wherein the polyether polyol is prepared by reaction of an alkylene oxide with a polyhydric alcohol selected from the group consisting of a sugar / glycerine mixture, sorbitol, or a sugar / pentaerythritol mixture. The dispersion stabilizer of claim 1, wherein the vinyltrialkoxy silane is selected from the group consisting of vinyl trimethoxy silane, vinyl triethoxy silane, vinyl tripropoxy, and mixtures thereof. A polymer polyol prepared by polymerizing at least one ethylenically unsaturated monomer in a polyol comprising the dispersion stabilizer of claim 1 with a free radical polymerization initiator. The polymer polyol of claim 4, wherein the free radical polymerization initiator is an azo compound. The polymer polyol according to claim 4, wherein ethylbenzene is used as a chain transfer agent. The polymer polyol of claim 4, wherein the at least one ethylenically unsaturated monomer is a mixture of styrene and acrylonitrile. 8. The polymer polyol of claim 7, wherein the ratio of styrene and acrylonitrile mixture is from 20:80 to 80:20. A method for producing a flexible polyurethane foam prepared by reacting the polymer polyol of Claims 4-8 with an isocyanate compound in the presence of a blowing agent and a catalyst.