Method for producing polymer polyol

Abstract

Disclosed is a method for producing a polymer polyol, comprising: (a) polymerizing a polyol and an aromatic vinyl monomer in the presence of an organic diluent; (b) polymerizing the product of step (a) by adding a polyol, an aromatic vinyl monomer, and an unsaturated nitrile monomer; and (c) removing the organic diluent from the product of step (b), wherein the organic diluent is compatible with the polymer of the aromatic vinyl monomer.

Description

[Technical field]

[0001] The present invention relates to a method for producing a polymer polyol. [Background technology]

[0002] Polymer polyol (POP) is used for the purpose of enhancing the hardness of polyurethane foam, and refers to a product in which solid polymer particles are dispersed in a liquid base polyol. In general, styrene-acrylonitrile (SAN) copolymer is used as the solid particles dispersed in polymer polyol, and it acts as a support inside the urethane cell structure during the production of polyurethane foam, thereby maintaining the elasticity of the foam while increasing its hardness.

[0003] Due to this hardness improving effect, polymer polyols are widely used in polyurethane foam products for molds as well as slabs. Recently, the polyurethane foam market has been experiencing an increasing demand for low-density, high-hardness products that have high hardness even at low density. To satisfy such low-density, high-hardness characteristics, polymer polyol products are required to have a high solid content. However, when the solid content of a polymer polyol product is increased, a sudden increase in viscosity and agglomeration occur due to a decrease in dispersion stability between particles, and it is known that it is very difficult to increase the solid content while minimizing these problems.

[0004] Increasing the proportion of SAN particles dispersed in the polymer polyol narrows the distance between dispersed particles, which increases collisions and causes a rapid drop in interparticle dispersion stability above the solid content limit, resulting in aggregation. In particular, when powdered SAN particles are directly dispersed in a base polyol to produce a polymer polyol, aggregation occurs more rapidly as the solid content increases, so a method of forming the SAN polymer by directly polymerizing it inside the polyol is used.

[0005] A seed polymerization technique was attempted in which seed particles grafted with a macromer that imparts a dispersion stabilizing effect are pre-injected in the initial stage of polymer polyol production. The seed particles added in the initial production process act as a polymerization stabilizer that provides a buffering effect between the SAN particles formed in the later stage due to their high dispersion stability, making it possible to produce polymer polyols with higher solid contents than conventional production methods. However, there is a problem in that it is difficult to stably produce polymer polyols with ultra-high solid contents of 50% or more. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a method for stably and easily producing a polymer polyol having a high solid content. [Means for solving the problem]

[0007] According to one embodiment, there is provided a method for producing a polymer polyol, comprising: (a) polymerizing an aromatic vinyl monomer in the presence of an organic diluent and a polyol; (b) polymerizing the product of step (a) by further adding a polyol, an aromatic vinyl monomer, and an unsaturated nitrile monomer; and (c) removing the organic diluent from the product of step (b), wherein the organic diluent is compatible with the aromatic vinyl polymer.

[0008] In one embodiment, the organic diluent is n-octane, n-dodecane, cyclohexane, methylcyclohexane, benzene, toluene, naphthalene, styrene, o-xylene, ethylbenzene, p-diethylbenzene, chloromethane, methylene chloride, 1,1-dichloroethylene, ethylene dichloride, chloroform, 1,1-dichloroethane, trichloroethylene, carbon tetrachloride, chlorobenzene, o-dichlorobenzene, tetrahydrofuran, 1,4-dioxane, dibenzyl ether, acetone, methyl ethyl ketone, cyclohexanone, diethyl ketone, acetophenone, methyl isobutyl ketone, methyl isoamyl ketone, isophorone, diisobutyl ketone, methyl acetate, ethyl formate, propylene-1,2-carbonate, ethyl acetate, diethyl carbonate, n-butyl acetate, 2-ethoxyethyl acetate, isoamyl acetate. The alkyl group may be at least one selected from the group consisting of ethyl acetate, 2-nitropropane, nitrobenzene, pyridine, morpholine, aniline, N-methyl-2-pyrrolidone, cyclohexylamine, quinoline, N,N-dimethylformamide, carbon disulfide, dimethyl sulfoxide, ethanethiol, ethanol, allyl alcohol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, benzyl alcohol, cyclohexanol, diacetone alcohol, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, 1-decanol, benzoic acid, stearic acid, phenol, resorcinol, m-cresol, methyl salicylate, ethylene glycol, glycerol, and propylene glycol.

[0009] In one embodiment, the polyol may have a weight average molecular weight of 1,000 to 6,000 g / mol.

[0010] In one embodiment, the polyol may have a hydroxyl value of 30 to 60 mgKOH / g.

[0011] In one embodiment, the aromatic vinyl monomer may be at least one selected from the group consisting of styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene, 5-tert-butyl-2-methylstyrene, tert-butoxystyrene, 2-tert-butylstyrene, 3-tert-butylstyrene, 4-tert-butylstyrene, N,N-dimethylaminoethylstyrene, 1-vinyl-5-hexylnaphthalene, 1-vinylnaphthalene, divinylnaphthalene, divinylbenzene, trivinylbenzene, vinylbenzyldimethylamine, (4-vinylbenzyl)dimethylaminoethyl ether, vinylpyridine, vinylxylene, diphenylethylene, and halogen-substituted styrenes.

[0012] In one embodiment, the unsaturated nitrile monomer may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile, and α-chloroacrylonitrile.

[0013] In an embodiment, in step (a), the weight ratio of the polyol to the aromatic vinyl monomer may be 100:25-50, respectively.

[0014] In one embodiment, in step (a), the weight ratio of the organic diluent to the aromatic vinyl monomer may be 100:15-120, respectively.

[0015] In one embodiment, the weight ratio of the polyol in step (a) to the polyol further added in step (b) may be 100:100-500, respectively.

[0016] In one embodiment, the weight ratio of the aromatic vinyl monomer in step (a) to the total monomer further added in step (b) may be 100:100 to 1,500, respectively.

[0017] In one embodiment, the produced polymer polyol may have a solid content of 55% by weight or more and a viscosity at 25° C. of 15,000 to 55,000 cps.

[0018] In one embodiment, steps (a) to (c) may be carried out in a one-pot process. Effect of the Invention

[0019] According to one embodiment, a method for stably and easily producing a polymer polyol with a high solid content can be provided.

[0020] It should be understood that the effects of one embodiment of this specification are not limited to the effects described above, but include all effects that can be inferred from the configuration described in the detailed description or claims of this specification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present specification will be described with reference to a specific example. However, the subject matter described in the present specification may be embodied in various different forms, and therefore is not limited to the example described herein.

[0022] Throughout the specification, when any part is said to be "connected" to another part, this includes not only the case where it is "directly connected" to another part, but also the case where it is "indirectly connected" with another member therebetween. Furthermore, when any part is said to "include" a certain component, this does not mean that it excludes other components, but that it can further include other components, unless otherwise specified to the contrary.

[0023] When a range of numerical values ​​is given herein, unless a specific range thereof is stated otherwise, the values ​​have the precision of significant figures provided by standard rules in chemistry for significant figures, for example, the number 10 includes a range of 5.0 to 14.9, and the number 10.0 includes a range of 9.50 to 10.49.

[0024] In this specification, "polyurethane" refers to a polymer material having a large amount of urethane (-NHCOO) bonds, and is generally used after being molded and processed into a foam, which is a lightweight material having a honeycomb shape, through a polymer reaction that produces bubbles. "Polyurethane foam" is generally classified into flexible, rigid, and semi-rigid.

[0025] In this specification, "polymer polyol (POP)" is also called copolymer polyol (CPP), and refers to a product in which particulated organic and inorganic materials are dispersed in a certain amount in liquid base polyol. Generally, it is widely used in various fields such as seats, bedding, and automobile parts to improve the hardness and breathability of flexible and semi-rigid polyurethane foams.

[0026] In this specification, the term "macromer" is also referred to as a macromonomer, which is a macromolecule having a reactive end group and can be introduced as a monomer into a polymer chain to improve polymerization stability. For example, polyols containing ethylenically unsaturated functional groups can be used as macromers.

[0027] Method for producing polymer polyol A method for producing a polymer polyol according to one embodiment includes the steps of: (a) polymerizing an aromatic vinyl monomer in the presence of an organic diluent and a polyol; (b) polymerizing the product of step (a) by further adding a polyol, an aromatic vinyl monomer, and an unsaturated nitrile monomer; and (c) removing the organic diluent from the product of step (b). The organic diluent may be compatible with the aromatic vinyl polymer.

[0028] The above-mentioned preparation method is a soluble seed polymerization method different from the conventional seed polymerization, and can stably and easily prepare a polymer polyol having a high solid content.

[0029] The step (a) involves the polymerization of an aromatic vinyl monomer alone in the presence of an organic diluent and a polyol. By using an organic diluent capable of dissolving an aromatic vinyl polymer polymerized from an aromatic vinyl monomer, the aromatic vinyl polymer can be dissolved in the organic diluent and polyol in the form of a polymer chain without being solidified into particles.

[0030] The step (a) may be carried out at a temperature of 100 to 150°C, for example, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, or any value between any two of these, for a period of 0.1 to 3 hours, for example, 0.1 hours, 0.5 hours, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, or any value between any two of these. Since the aromatic vinyl polymer can be dissolved in the mixture of the organic diluent and the polyol under high temperature conditions, the steps (a) and (b) may be carried out continuously while maintaining the temperature.

[0031] The organic diluent may be n-octane, n-dodecane, cyclohexane, methylcyclohexane, benzene, toluene, naphthalene, styrene, o-xylene, ethylbenzene, p-diethylbenzene, chloromethane, methylene chloride, 1,1-dichloroethylene, ethylene dichloride, chloroform, 1,1-dichloroethane, trichloroethylene, carbon tetrachloride, chlorobenzene, o-dichlorobenzene, tetrahydrofuran, 1,4-dioxane, dibenzyl ether, acetone, methyl ethyl ketone, cyclohexanone, diethyl ketone, acetophenone, methyl isobutyl ketone, methyl isoamyl ketone, isophorone, diisobutyl ketone, methyl acetate, ethyl formate, propylene-1,2-carbonate, ethyl acetate, diethyl carbonate, n-butyl acetate, 2-ethoxyethyl acetate, isoamyl acetate, 2-nitropropane, The alkyl group may be at least one selected from the group consisting of nitrobenzene, pyridine, morpholine, aniline, N-methyl-2-pyrrolidone, cyclohexylamine, quinoline, N,N-dimethylformamide, carbon disulfide, dimethyl sulfoxide, ethanethiol, ethanol, allyl alcohol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, benzyl alcohol, cyclohexanol, diacetone alcohol, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, 1-decanol, benzoic acid, stearic acid, phenol, resorcinol, m-cresol, methyl salicylate, ethylene glycol, glycerol, and propylene glycol, but is not limited thereto.

[0032] The polyol may have a weight average molecular weight of 1,000 to 6,000 g / mol, for example, 1,000 g / mol, 1,500 g / mol, 2,000 g / mol, 2,500 g / mol, 3,000 g / mol, 3,500 g / mol, 4,000 g / mol, 4,500 g / mol, 5,000 g / mol, 5,500 g / mol, 6,000 g / mol, or a range between two of these values, but is not limited thereto. If the weight average molecular weight of the polyol is too low, the mechanical properties such as hardness of the final product may be reduced, and if it is too high, aggregation may occur or the viscosity may become excessively high, resulting in reduced processability.

[0033] The polyol may have a hydroxyl value (OHV) of 30 to 60 mgKOH / g, for example, 30 mgKOH / g, 35 mgKOH / g, 40 mgKOH / g, 45 mgKOH / g, 50 mgKOH / g, 55 mgKOH / g, 60 mgKOH / g, or a range between two of these values, but is not limited thereto. The hydroxyl value is the weight of potassium hydroxide required to neutralize the acetic acid bonded to the acetyl compound obtained from 1 g of polyol. The hydroxyl value indicates the hydroxyl group content in the polyol, and the ratio of the polyol can be determined during the polymerization of polyurethane.

[0034] The viscosity of the polyether polyol may be 150 to 700 cps, for example, 150 cps, 200 cps, 250 cps, 300 cps, 350 cps, 400 cps, 450 cps, 500 cps, 550 cps, 600 cps, 650 cps, 700 cps, or a range between two of these values. If the viscosity is less than 150 cps, the mechanical properties and durability of the polyurethane foam may be reduced, and if the viscosity exceeds 700 cps, the viscosity of the polyurethane may increase excessively, resulting in reduced processability.

[0035] The aromatic vinyl monomer may be at least one selected from the group consisting of styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene, 5-tert-butyl-2-methylstyrene, tert-butoxystyrene, 2-tert-butylstyrene, 3-tert-butylstyrene, 4-tert-butylstyrene, N,N-dimethylaminoethylstyrene, 1-vinyl-5-hexylnaphthalene, 1-vinylnaphthalene, divinylnaphthalene, divinylbenzene, trivinylbenzene, vinylbenzyldimethylamine, (4-vinylbenzyl)dimethylaminoethyl ether, vinylpyridine, vinylxylene, diphenylethylene, and halogen-substituted styrenes, but is not limited thereto.

[0036] In step (a), the aromatic vinyl monomer is polymerized alone to produce a homopolymer seed, which is dissolved in the organic diluent and polyol and can eliminate the polymer from the initial polymerization stage as solids. This allows the production of polymer polyol to be carried out under conditions of a low solid content compared to the actual polymerization rate, thereby preventing agglomeration.

[0037] The step (a) may be carried out by further adding a conventional macromer polymerization stabilizer and a radical polymerization initiator, in addition to the organic diluent, polyol, and aromatic vinyl monomer, which provide a dispersion stabilizing effect.

[0038] The polymerization initiator may be at least one selected from the group consisting of azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 1,1'-azobis(cyclohexanecarbonitrile), benzoyl peroxide, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, cyclohexanone peroxide, lauroyl peroxide, and potassium persulfate, but is not limited thereto.

[0039] In step (a), the aromatic vinyl monomer may be 25 to 50 parts by weight, for example, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, or a range between two of these values, based on 100 parts by weight of the polyol. If the content of the aromatic vinyl monomer relative to the polyol is outside the above range, aggregation may occur or the mechanical properties of the final product may be deteriorated.

[0040] In the step (a), the aromatic vinyl monomer may be 15 to 120 parts by weight, for example, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight, 90 parts by weight, 95 parts by weight, 100 parts by weight, 105 parts by weight, 110 parts by weight, 115 parts by weight, 120 parts by weight, or a range between two of these values. If the content of the aromatic vinyl monomer relative to the organic diluent is outside the above range, the aromatic vinyl polymer may be coagulated, or excessive energy and cost may be required to remove the organic diluent in the step (c).

[0041] The step (b) is a step of polymerizing the product of the step (a) by further adding polyol, aromatic vinyl monomer, and unsaturated nitrile monomer. In order to maintain the aromatic vinyl polymer in a dissolved state, the step (b) may be carried out for 0.1 to 10 hours, for example, 0.1 hours, 0.5 hours, 1.0 hours, 1.5 hours, 2.0 hours, 2.5 hours, 3.0 hours, 3.5 hours, 4.0 hours, 4.5 hours, 5.0 hours, 5.5 hours, 6.0 hours, 6.5 hours, 7.0 hours, 7.5 hours, 8.0 hours, 8.5 hours, 9.0 hours, 9.5 hours, 10.0 hours, or a time period in the range between two of these values, under the reaction temperature condition of the step (a).

[0042] The unsaturated nitrile monomer may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile, and α-chloroacrylonitrile, but is not limited thereto.

[0043] The additional addition of step (b) may be carried out by premixing the polyol, the aromatic vinyl monomer, the unsaturated nitrile monomer and the radical polymerization initiator and then continuously adding the resulting mixture to the product of step (a).

[0044] After step (b), the reaction temperature is increased by 5 to 15° C., and the reaction mixture is aged for 0.5 to 3 hours to improve the stability of the polymer.

[0045] Based on 100 parts by weight of the polyol in step (a), the amount of the polyol further added in step (b) is 100 to 500 parts by weight, for example, 100 parts by weight, 110 parts by weight, 120 parts by weight, 130 parts by weight, 140 parts by weight, 150 parts by weight, 160 parts by weight, 170 parts by weight, 180 parts by weight, 190 parts by weight, 200 parts by weight, 210 parts by weight, 220 parts by weight, 230 parts by weight, 240 parts by weight, 250 parts by weight, 260 parts by weight, 270 parts by weight, 280 parts by weight, 290 parts by weight, 300 parts by weight, 310 parts by weight, 320 parts by weight, 330 parts by weight, 340 parts by weight, 350 parts by weight, 360 parts by weight, 370 parts by weight, 380 parts by weight, 390 parts by weight, 400 parts by weight, 410 parts by weight, 420 parts by weight, 430 parts by weight, 440 parts by weight, 450 parts by weight, 460 parts by weight, 470 parts by weight, 480 parts by weight, 490 parts by weight, 500 parts by weight, 510 parts by weight, 520 parts by weight, 530 parts by weight, 540 parts by weight, 550 parts by weight, 560 parts by weight, 570 parts by weight, 580 parts by weight, 590 parts by weight, 600 parts by weight, 610 parts by weight, 620 parts by weight, 630 parts by weight, 640 parts by weight, 650 parts by weight, 660 parts by weight, 670 parts by weight , 280 parts by weight, 290 parts by weight, 300 parts by weight, 310 parts by weight, 320 parts by weight, 330 parts by weight, 340 parts by weight, 350 parts by weight, 360 parts by weight, 370 parts by weight, 380 parts by weight, 390 parts by weight, 400 parts by weight, 410 parts by weight, 420 parts by weight, 430 parts by weight, 440 parts by weight, 450 parts by weight, 460 parts by weight, 470 parts by weight, 480 parts by weight, 490 parts by weight, 500 parts by weight, or a range between two of these values. If the proportions of the polyol in the steps (a) and (b) are outside the above ranges, the particle size of the particles dispersed in the polymer polyol may be non-uniform, resulting in a decrease in quality, or the quality may be decreased due to the generation of soluble oligomers.

[0046] Based on 100 parts by weight of the aromatic vinyl monomer in step (a), the total amount of the monomers further added in step (b) is 100 to 1,500 parts by weight, for example, 100 parts by weight, 110 parts by weight, 120 parts by weight, 130 parts by weight, 140 parts by weight, 150 parts by weight, 160 parts by weight, 170 parts by weight, 180 parts by weight, 190 parts by weight, 200 parts by weight, 210 parts by weight, 220 parts by weight, 230 parts by weight, 240 parts by weight, 250 parts by weight, 260 parts by weight, 270 parts by weight, 280 parts by weight, 290 parts by weight, 300 parts by weight, 310 parts by weight, 320 parts by weight, 330 parts by weight, 340 parts by weight, 350 parts by weight, 360 parts by weight, 370 parts by weight, 380 parts by weight, 390 parts by weight, 400 parts by weight, 410 parts by weight, 420 parts by weight, 430 parts by weight, 440 parts by weight, 450 parts by weight, 460 parts by weight, 470 parts by weight, 480 parts by weight, 490 parts by weight, 500 parts by weight, 510 parts by weight, 520 parts by weight, 530 parts by weight, 540 parts by weight, 550 parts by weight, 560 parts by weight, 570 parts by weight, 580 parts by weight, 590 parts by weight, 600 parts by weight, 610 parts by weight, 620 parts by weight, 630 parts by weight, 640 parts by weight, 650 parts by weight, 660 parts by weight, 67 Parts by weight, 360 parts by weight, 370 parts by weight, 380 parts by weight, 390 parts by weight, 400 parts by weight, 410 parts by weight, 420 parts by weight, 430 parts by weight, 440 parts by weight, 450 parts by weight, 460 parts by weight, 470 parts by weight, 480 parts by weight, 490 parts by weight, 500 parts by weight, 600 parts by weight, 610 parts by weight, 620 parts by weight Parts by weight, 630 parts by weight, 640 parts by weight, 650 parts by weight, 660 parts by weight, 670 parts by weight, 680 parts by weight, 690 parts by weight, 700 parts by weight, 710 parts by weight, 720 parts by weight, 730 parts by weight, 740 parts by weight, 750 parts by weight, 760 parts by weight, 770 parts by weight, 780 parts by weight, 790 parts by weight, 80 parts by weight 0 parts by weight, 810 parts by weight, 820 parts by weight, 830 parts by weight, 840 parts by weight, 850 parts by weight, 860 parts by weight, 870 parts by weight, 880 parts by weight, 890 parts by weight, 900 parts by weight, 910 parts by weight, 920 parts by weight, 930 parts by weight, 940 parts by weight, 950 parts by weight, 960 parts by weight, 970 parts by weight, 9 80 parts by weight, 990 parts by weight, 1,000 parts by weight, 1,010 parts by weight, 1,020 parts by weight, 1,030 parts by weight, 1,040 parts by weight, 1,050 parts by weight, 1,060 parts by weight, 1,070 parts by weight, 1,080 parts by weight, 1,090 parts by weight, 1,100 parts by weight, 1,110 parts by weight, 1,12 0 parts by weight, 1,130 parts by weight, 1,140 parts by weight, 1,150 parts by weight, 1,160 parts by weight, 1,170 parts by weight, 1,180 parts by weight, 1,190 parts by weight, 1,200 parts by weight, 1,210 parts by weight, 1,220 parts by weight, 1,230 parts by weight, 1,240 parts by weight, 1,250 parts by weight, 1,2 60 parts by weight, 1,270 parts by weight, 1,280 parts by weight, 1,290 parts by weight, 1,300 parts by weight, 1,310 parts by weight, 1,320 parts by weight, 1,330 parts by weight, 1,340 parts by weight, 1,350 parts by weight, 1,360 parts by weight, 1,370 parts by weight, 1,380 parts by weight, 1,390 parts by weight, 1,The weight ratio may be 400 parts by weight, 1,410 parts by weight, 1,420 parts by weight, 1,430 parts by weight, 1,440 parts by weight, 1,450 parts by weight, 1,460 parts by weight, 1,470 parts by weight, 1,480 parts by weight, 1,490 parts by weight, 1,500 parts by weight, or a range between two of these values. The total weight of the monomers added in step (b) refers to the weight ratio of the total weight of the aromatic vinyl monomer and the unsaturated nitrile monomer. If the weight ratio of the monomers in steps (a) and (b) is outside the above range, aggregation may occur during the preparation of the seeds, or the viscosity may increase abnormally.

[0047] The step (c) is to remove the organic diluent used as a solvent, and if the physical properties of the polymer polyol itself are not significantly affected, a known solvent removal process such as degassing or drying can be applied. After the step (c), the initially polymerized aromatic vinyl polymer dissolved in the form of polymer chains precipitates as solid particles, and the solid content of the final product can be stably increased.

[0048] The solids content of the produced polymer polyol is 55% by weight or more, for example, 55% by weight, 56% by weight, 57% by weight, 58% by weight, 59% by weight, 60% by weight, or a range between two of these values, or 60% by weight or more, and the viscosity at 25°C is 15,000 to 55,000 cps, for example, 15,000 cps, 16,000 cps, 17,000 cps, 18,000 cps, 19,000 cps, 20,000 cps, 21,000 cps, 22,000 cps, 23,000 cps, 24,000 cps, 25,000 cps, 26,000 cps, 27,000 cps, 28,000 cps, 29,000 cps, 30,000 cps, 31,000 cps, 32,000 cps, 33,000 cps, 34,000 cps, 35,000 cps, 36,000 cps, 37,000 cps, 38,000 cps, 39,000 cps, 40,000 cps, 41,000 cps, 42,000 cps, 43,000 cps, 44,000 cps, 45,000 cps, 46,000 cps, 47,000 cps, 48,000 cps, 49,000 cps, 48,000 cps The value may be 0,000cps, 31,000cps, 32,000cps, 33,000cps, 34,000cps, 35,000cps, 36,000cps, 37,000cps, 38,000cps, 39,000cps, 40,000cps, 41,000cps, 42,000cps, 43,000cps, 44,000cps, 45,000cps, 46,000cps, 47,000cps, 48,000cps, 49,000cps, 50,000cps, 51,000cps, 52,000cps, 53,000cps, 54,000cps, 55,000cps or a range between any two of these values. When the process is carried out using an organic diluent that is compatible with the aromatic vinyl polymer, the solids content can be temporarily reduced during polymerization to produce a polymer polyol having a high solids content without flocculation.

[0049] The steps (a) to (c) may be carried out in a one-pot process. By applying the one-pot process, a polymer polyol is produced while preventing precipitation of the seeds produced in the step (a), and the solvent is removed to form solid particles, thereby easily and stably realizing an ultra-high solid POP.

[0050] The examples of the present specification will be described in more detail below. However, the following experimental results are only representative experimental results among the above examples, and the scope and contents of the present specification should not be construed as being narrowed or limited by the examples. The respective effects of various embodiments of the present specification that are not explicitly described below will be specifically described in the corresponding parts.

[0051] sample Base polyol: Polyether polyol Polymerizable unsaturated monomers: styrene (SM), acrylonitrile (AN) Polymerization stabilizer: Macromonomer type polymerization stabilizer Polymerization initiator: azobisisobutyronitrile, 2,2'-azobis(2-methylpropionitrile) Organic diluents: Ethylbenzene (EB), Toluene (TOL), Isopropyl alcohol (IPA) Example 1 (1) Formation of soluble seeds 90 parts by weight of styrene, a polymerizable unsaturated monomer, and 0.9 parts by weight of azobisisobutyronitrile, a polymerization initiator, were mixed in a 4L reactor equipped with an agitator and completely dissolved at room temperature. Then, 40 parts by weight of macromer, a polymerization stabilizer, and 200 parts by weight of base polyol with a molecular weight of 3,000 g / mol, hydroxyl value of 56, and viscosity of 500 cps were added and stirred for 10 minutes. 300 parts by weight of ethylbenzene, an organic diluent, was further added to the reactor and completely dissolved. After the inputs were completely dissolved, the temperature of the reactant was raised to 120°C for 1 hour while stirring at a speed of 250 rpm. Then, the styrene monomer was polymerized while maintaining the temperature for 1 hour to produce a soluble seed. The polystyrene produced was dissolved in the hot ethylbenzene and polyol, and the reactant remained transparent. In addition, after reacting for 1 hour, a portion of the sample was taken and cooled to room temperature. The increase in turbidity was observed, confirming that the polystyrene had dissolved in the form of polymer chains.

[0052] (2) Polymerization of polymer polyol After preparing the soluble seeds, 777 parts by weight of styrene, which is a polymerizable unsaturated monomer, and 333 parts by weight of acrylonitrile were mixed with 11.1 parts by weight of azobisisobutyronitrile, which is a polymerization initiator, and completely dissolved. The mixture was then added to a continuous addition tank together with 560 parts by weight of the base polyol, stirred for 5 minutes, and then continuously added to the soluble seed reactor for 5 hours. The temperature and stirring conditions of the reactor were maintained the same as those during the polymerization of the soluble seeds. After addition, the temperature was raised to 130° C. and aged for 2 hours.

[0053] (3) Particleization of polystyrene polymer The polymer was transferred to a purification tank and depressurized at 120° C. for 20 hours to remove ethylbenzene dissolved in the polymer by degassing, thereby obtaining a polymer polyol.

[0054] Example 2 A polymer polyol was prepared in the same manner as in Example 1, except that ethylbenzene was replaced with toluene as the organic diluent.

[0055] Example 3 A polymer polyol was prepared in the same manner as in Example 1, except that the amount of styrene monomer added during the preparation of the soluble seeds was changed from 90 parts by weight to 60 parts by weight.

[0056] Example 4 A polymer polyol was produced in the same manner as in Example 1, except that the base polyol had a molecular weight of 5,000 g / mol and a hydroxyl value of 34.

[0057] Example 5 A polymer polyol was prepared in the same manner as in Example 1, except that the amount of the organic diluent ethylbenzene added was changed from 300 parts by weight to 400 parts by weight.

[0058] Comparative Example 1 A polymer polyol was prepared in the same manner as in Example 1, except that the 90 parts by weight of styrene, which is the monomer added in the preparation of the soluble seeds, was changed to a mixture of 63 parts by weight of styrene and 27 parts by weight of acrylonitrile, and the initial seed particles were SAN copolymers that were not soluble in the base polyol and ethylbenzene mixed solvent.

[0059] Comparative Example 2 A polymer polyol was prepared in the same manner as in Example 1, except that the organic diluent ethylbenzene was replaced with isopropyl alcohol, which is a solvent incompatible with polystyrene.

[0060] Comparative Example 3 A polymer polyol was prepared in the same manner as in Example 1, except that in step (2), 777 parts by weight of styrene and 333 parts by weight of acrylonitrile were replaced with 1,110 parts by weight of styrene alone.

[0061] The results of the production of polymer polyols in Examples 1 to 5 and Comparative Examples 1 to 3 are shown in Table 1 below.

[0062] [Table 1]

[0063] Referring to Table 1, in Examples 1 to 5 in which a soluble seed was formed by homopolymerizing styrene and a polystyrene-soluble solvent was used as an organic diluent, a polymer polyol having a solid content of 60% or more that did not aggregate was produced.

[0064] On the other hand, in Comparative Example 1, an insoluble SAN copolymer seed made by polymerizing styrene and acrylonitrile was used, and aggregation occurred. In Comparative Example 2, polystyrene-incompatible isopropyl alcohol was used as an organic diluent, and the seed did not dissolve, so aggregation occurred. In Comparative Example 3, a polymer polyol was produced by homopolymerizing only styrene, and aggregation occurred.

[0065] The above description of the present invention is for illustrative purposes only, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. Therefore, the above-described embodiments should be understood to be illustrative and restrictive in all respects. For example, each component described as a single type may be implemented in a distributed form, and similarly, each component described as a distributed type may be implemented in a combined form.

[0066] The scope of the present invention is defined by the claims set forth below, and all modifications and variations that fall within the meaning and scope of the claims and their equivalent concepts should be understood to be included within the scope of the present invention.

Claims

1. (a) polymerizing only vinyl aromatic monomers as monomers in the presence of an organic diluent and a polyol; (b) further adding polyol, aromatic vinyl monomer and unsaturated nitrile monomer to the product of step (a) and polymerizing the product; (c) removing said organic diluent from the product of step (b); The organic diluent is n-octane, n-dodecane, cyclohexane, methylcyclohexane, benzene, toluene, naphthalene, styrene, o-xylene, ethylbenzene, p-diethylbenzene, chloromethane, methylene chloride, 1,1-dichloroethylene, ethylene dichloride, chloroform, 1,1-dichloroethane, trichloroethylene, carbon tetrachloride, chlorobenzene, o-dichlorobenzene, tetrahydrofuran, 1,4-dioxane, dibenzyl ether, acetone, methyl ethyl ketone, cyclohexanone, diethyl ketone, acetophenone, methyl isobutyl ketone, methyl isoamyl ketone, isophorone, diisobutyl ketone, methyl acetate, ethyl formate, propylene-1,2-carbonate, ethyl acetate, diethyl carbonate, n-butyl acetate, 2-ethoxyethyl acetate, isoamyl a acetate, 2-nitropropane, nitrobenzene, pyridine, morpholine, aniline, N-methyl-2-pyrrolidone, cyclohexylamine, quinoline, N,N-dimethylformamide, carbon disulfide, dimethyl sulfoxide, ethanethiol, ethanol, allyl alcohol, 1-propanol, 1-butanol, 2-butanol, benzyl alcohol, cyclohexanol, diacetone alcohol, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, 1-decanol, benzoic acid, stearic acid, phenol, resorcinol, m-cresol, methyl salicylate, ethylene glycol, glycerol, and propylene glycol; the polyol is a polyether polyol, The polyol has a weight average molecular weight of 1,000 to 6,000 g / mol.

2. The method for producing a polymer polyol according to claim 1, wherein the polyol has a hydroxyl value of 30 to 60 mgKOH / g.

3. The aromatic vinyl monomer is at least one selected from the group consisting of styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene, 5-tert-butyl-2-methylstyrene, tert-butoxystyrene, 2-tert-butylstyrene, 3-tert-butylstyrene, 4-tert-butylstyrene, N,N-dimethylaminoethylstyrene, 1-vinyl-5-hexylnaphthalene, 1-vinylnaphthalene, divinylnaphthalene, divinylbenzene, trivinylbenzene, vinylbenzyldimethylamine, (4-vinylbenzyl)dimethylaminoethyl ether, vinylpyridine, vinylxylene, diphenylethylene and halogen-substituted styrene. The method for producing a polymer polyol according to claim 1.

4. The method for producing a polymer polyol according to claim 1, wherein the unsaturated nitrile monomer is at least one selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile and α-chloroacrylonitrile.

5. The method for producing a polymer polyol according to claim 1, wherein the organic diluent is at least one selected from the group consisting of benzene, toluene, naphthalene, o-xylene, ethylbenzene, and p-diethylbenzene.

6. In the step (a), The method for producing a polymer polyol according to claim 1, wherein the weight ratio of the polyol to the aromatic vinyl monomer is 100:25 to 50, respectively.

7. In the step (a), The method for producing a polymer polyol according to claim 1, wherein the weight ratio of the organic diluent to the aromatic vinyl monomer is 100:15 to 120, respectively.

8. The method for producing a polymer polyol according to claim 1, wherein the weight ratio of the polyol in step (a) to the polyol further added in step (b) is 100:100 to 500, respectively.

9. The method for producing a polymer polyol according to claim 1, wherein the weight ratio of the aromatic vinyl monomer in step (a) to the total monomer added in step (b) is 100:100 to 1,500, respectively.

10. 2. The method for producing a polymer polyol according to claim 1, wherein the produced polymer polyol has a solids content of 55% by weight or more and a viscosity at 25° C. of 15,000 to 55,000 cps.

11. The method for producing a polymer polyol according to claim 1, wherein steps (a) and (b) are carried out in a one-pot process.

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