Dispersant raw material composition for polymer polyols, dispersant for polymer polyols, and polymer polyols

Abstract

This invention provides a polymer polyol dispersant raw material composition for producing low-viscosity polymer polyol dispersants. [Solution] A dispersant raw material composition for polymer polyols comprising (meth)acrylate (A) having one isocyanate group and one urethane bond, (meth)acrylate (B) having two urethane bonds, and diisocyanate (C), wherein in a chromatogram measured using a gel permeation chromatograph, when the sum of the peak areas corresponding to (meth)acrylate (A), (meth)acrylate (B), and diisocyanate (C) is taken as 100%, the peak area ratio of (meth)acrylate (A) is 70-84%, the peak area ratio of (meth)acrylate (B) is 15-20%, and the peak area ratio of diisocyanate (C) is 1-10%.

Description

Technical Field

[0001] The present invention relates to a dispersant raw material composition for polymer polyols, a dispersant for polymer polyols, and a polymer polyol. Background Art

[0002] A compound in which polymer particles, which are ethylenic polymers, are dispersed in a polyol such as a polyether polyol or a polyester polyol is called a polymer polyol. A polymer polyol is obtained by polymerizing an ethylenically unsaturated compound in a polyol in the presence of a polymerization initiator. In recent years, there has been a demand for weight reduction and higher hardness of polyurethane foam, and accordingly, there is a demand for increasing the concentration of polymer particles dispersed in the polyol of polymer polyols. Increasing the concentration of polymer particles increases the viscosity of the polymer polyol and degrades workability. Therefore, methods for obtaining polymer polyols with a high concentration of polymer particles and low viscosity have been studied.

[0003] As a countermeasure for increasing the concentration of polymer particles in a polyol, studies have been conducted to improve the dispersion stability of polymer particles by using a separately produced macromer-type dispersant (Patent Documents 1 and 2). However, since conventional macromer-type dispersants contain by-products and unreacted materials in their intermediates, these react during the production of the macromer-type dispersant, increasing the viscosity of the macromer-type dispersant itself. The polymer polyols produced using these dispersants also tend to have higher viscosity, and a method for obtaining a polymer polyol with lower viscosity is desired. Prior Art Documents Patent Documents

[0004] Patent Document 1 Japanese Unexamined Patent Publication No. 2021-050313 Patent Document 2 Japanese National Publication of International Patent Application No. 2022-552240 Summary of the Invention [Problems that the invention aims to solve]

[0005] The present invention aims to provide a polymer polyol dispersant raw material composition for producing a low-viscosity polymer polyol dispersant. Furthermore, the present invention aims to obtain a polymer polyol with low viscosity and a low polymer particle content, even at high polymer particle concentrations, by using the polymer polyol dispersant obtained from the above polymer polyol dispersant raw material composition. [Means for solving the problem]

[0006] The inventors of this invention arrived at this present invention after diligently studying to solve these problems. In other words, the present invention relates to a dispersant raw material composition for polymer polyols containing a (meth)acrylate (A) having one isocyanate group and one urethane bond, a (meth)acrylate (B) having two urethane bonds, and a diisocyanate (C), wherein, in a chromatogram measured using a gel permeation chromatograph, when the sum of the peak areas corresponding to the (meth)acrylate (A), the (meth)acrylate (B), and the diisocyanate (C) is taken as 100%, the peak area ratio of the (meth)acrylate (A) is 70-84%, the peak area ratio of the (meth)acrylate (B) is 15-20%, and the peak area ratio of the diisocyanate (C) is 1-10%. Furthermore, the present invention relates to a polymer polyol dispersant that is a reaction product of the polymer polyol dispersant raw material composition and a 3- to 6-valent polyol, and contains a polyol in which (meth)acryloyl groups have been introduced via urethane bonds. Furthermore, the present invention relates to a polymer polyol in which polymer particles containing structural units derived from a polyol in which (meth)acryloyl groups are introduced via urethane bonds, and which also contain structural units derived from styrene and acrylonitrile are dispersed in the polyol, wherein the structural units are obtained by copolymerizing the (meth)acryloyl groups with the styrene and acrylonitrile. [Effects of the Invention]

[0007] The polymer polyol dispersant raw material composition of the present invention can produce a low-viscosity polymer polyol dispersant. Furthermore, by using the polymer polyol dispersant of the present invention, it is possible to obtain a polymer polyol with a low viscosity and a low amount of coarse polymer particles, even at high polymer particle concentrations. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows an example of a chromatogram obtained by measuring the polymer polyol dispersant raw material composition of the present invention using gel permeation chromatography. [Modes for carrying out the invention]

[0009] The present invention will be described in detail below.

[0010] The first invention of this application is a dispersant raw material composition for polymer polyols containing a (meth)acrylate (A) having one isocyanate group and one urethane bond, a (meth)acrylate (B) having two urethane bonds, and a diisocyanate (C), wherein, in a chromatogram measured using a gel permeation chromatograph, when the sum of the peak areas corresponding to the (meth)acrylate (A), the (meth)acrylate (B), and the diisocyanate (C) is taken as 100%, the peak area ratio of the (meth)acrylate (A) is 70-84%, the peak area ratio of the (meth)acrylate (B) is 15-20%, and the peak area ratio of the diisocyanate (C) is 1-10%.

[0011] The polymer polyol dispersant raw material composition of the first invention of this application contains (meth)acrylate (A) having one isocyanate group and one urethane bond, (meth)acrylate (B) having two urethane bonds, and diisocyanate (C). In this invention, the notation "(meth)acrylate" means acrylate and / or methacrylate, the notation "(meth)acrylic" means acrylic and / or methacrylic, and the notation "(meth)acryloyl" means acryloyl and / or methacryloyl.

[0012] (Meth)acrylate (A), which has one isocyanate group and one urethane bond, is a (meth)acrylate that contains isocyanate (a) and (meth)acrylate (b), which has one equimolar hydroxyl group with isocyanate (a), as constituent materials.

[0013] Examples of isocyanates (a) include monoisocyanates and polyisocyanates.

[0014] Examples of monoisocyanates include phenyl isocyanate, butyl isocyanate, hexyl isocyanate, t-butyl isocyanate, cyclohexyl isocyanate, octyl isocyanate, 2-ethylhexyl isocyanate, dodecyl isocyanate, adamantyl isocyanate, 2,6-dimethylphenyl isocyanate, 3,5-dimethylphenyl isocyanate, and 2,6-dipropylphenyl isocyanate.

[0015] Examples of polyisocyanates include linear aliphatic polyisocyanates with 4 to 20 carbon atoms (a1), alicyclic polyisocyanates with 6 to 22 carbon atoms (a2), and aromatic polyisocyanates with 8 to 22 carbon atoms (a3).

[0016] Examples of chain-like aliphatic polyisocyanates (a1) having 4 to 20 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. Note that the carbon number includes the carbon atoms in the isocyanate group.

[0017] Examples of alicyclic polyisocyanates (a2) having 6 to 22 carbon atoms include cyclohexane-1,3-diylbismethylene diisocyanate, isophorone diisocyanate (IPDI), 2,4- or 2,6-methylcyclohexane diisocyanate (hydrogenated TDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI; hereafter sometimes referred to as MDIH), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis(2-isocyanate ethyl)-4-cyclohexylene-1,2-dicarboxylate, 2,5- or 2,6-norbornane diisocyanate, and dimer acid diisocyanate.

[0018] As the aromatic polyisocyanate (a3) having 8 to 22 carbon atoms, examples include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (toluene diisocyanate: TDI), 4,4'- or 2,4'-diphenylmethane diisocyanate (MDI), m- or p-isocyanate phenyl sulfonyl isocyanate, 4,4'-diisocyanate biphenyl, 3,3'-dimethyl-4,4'-diisocyanate biphenyl, 3,3'-dimethyl-4,4'-diisocyanate diphenylmethane, 1,5-naphthylene diisocyanate, m- or p-xylylene diisocyanate (XDI), and α,α,α',α'-tetramethylxylylene diisocyanate (TMXDI).

[0019] Among these isocyanates (a), from the viewpoint of dispersion stability of polymer particles, polyisocyanates are preferable; alicyclic polyisocyanates (a2) having 6 to 22 carbon atoms and aromatic polyisocyanates (a3) having 8 to 22 carbon atoms are more preferable; alicyclic polyisocyanates having 6 to 20 carbon atoms and aromatic polyisocyanates having 8 to 20 carbon atoms are still more preferable; MDIH, cyclohexane-1,3-diylbismethylene diisocyanate, IPDI, XDI, TMXDI, MDI and TDI are particularly preferable; and MDIH, IPDI, MDI and TDI are most preferable. One type of isocyanate (a) may be used alone, or two or more types may be used in combination.

[0020] As the (meth)acrylate (b) having one hydroxyl group, examples include hydroxyalkyl (meth)acrylate (b1) and polyalkylene glycol mono(meth)acrylate (b2).

[0021] As the hydroxyalkyl (meth)acrylate (b1), preferred examples include hydroxyalkyl (meth)acrylates having 4 to 20 carbon atoms, and specific examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxypropyl (meth)acrylate.

[0022] Examples of polyalkylene glycol mono(meth)acrylate (b2) include polyethylene glycol mono(meth)acrylate and polypropylene glycol mono(meth)acrylate.

[0023] Among the (meth)acrylates (b) having one hydroxyl group, hydroxyalkyl (meth)acrylate (b1) is preferred from the viewpoint of reactivity in the urethane reaction and low viscosity, more preferably hydroxyalkyl (meth)acrylate having 4 to 20 carbon atoms, and particularly preferably 2-hydroxyethyl (meth)acrylate. (Meth)acrylate (b) having one hydroxyl group may be used alone or in combination of two or more types.

[0024] The (meth)acrylate (A) having one isocyanate group and one urethane bond in the first invention of this application can be produced by reacting isocyanate (a) with (meth)acrylate (b) containing one equimolar hydroxyl group with isocyanate (a) by a known method. In this case, when isocyanate (a) is diisocyanate, a (meth)acrylate having one urethane bond and one isocyanate group in one molecule is obtained. In particular, a method of producing a (meth)acrylate having one isocyanate group and one urethane bond by adding a diisocyanate selected from the group consisting of the polyisocyanates (a1), (a2), and (a3) ​​to a (meth)acrylate (b) having one equimolar hydroxyl group with the diisocyanate is preferred from the viewpoint of dispersion stability of polymer particles.

[0025] In the addition reaction described above, the content of (meth)acrylate (A) having one isocyanate group and one urethane bond, (meth)acrylate (B) having two urethane bonds, and unreacted diisocyanate (C) in the reaction product can be controlled by appropriately setting the equivalent ratio (NCO / OH) of the supply of isocyanate groups (NCO groups) derived from diisocyanate and the supply of hydroxyl groups (OH groups) derived from (meth)acrylate (b) having one hydroxyl group, the amount of urethane catalyst used, and the reaction temperature. For example, under conditions where NCO / OH is around 1, the formation of (A) proceeds relatively easily, while under conditions where NCO / OH is less than 1 (OH excess) or under conditions where the amount of catalyst is increased, the formation of (B) proceeds relatively easily. On the other hand, under conditions where NCO / OH is greater than 1 (NCO excess), unreacted diisocyanate (C) tends to remain. The reaction temperature affects the ratio of these products, so it should be set to achieve the desired composition.

[0026] In the above addition reaction, a urethane catalyst may be used. Examples of urethane catalysts include metal compounds (organobismuth compounds, organotin compounds, and organotitanium compounds, etc.) and quaternary ammonium salts.

[0027] The (meth)acrylate (B) having two urethane bonds is not particularly limited as long as it is a (meth)acrylate having two urethane groups, but from the viewpoint of increasing the concentration and decreasing the viscosity of the polymer polyol, it is preferably a compound represented by the following general formula (1).

[0028] [ka]

[0029] In general formula (1), R 1 represents a hydrogen atom or a methyl group, n1 and n2 represent the same or different integers from 1 to 5, and X represents an alkylene group or phenylene group in which the hydrogen atom may be substituted with an alkyl group having 1 to 30 carbon atoms. n1 or n2 is preferably an integer of 1, and more preferably both are integers of 1.

[0030] Examples of compounds represented by general formula (1) include reaction products of a chain-like aliphatic polyisocyanate (a1) having 4 to 20 carbon atoms and a hydroxyalkyl (meth)acrylate (b1), reaction products of a chain-like aliphatic polyisocyanate (a1) having 4 to 20 carbon atoms and a polyalkylene glycol mono(meth)acrylate (b2), reaction products of an aromatic polyisocyanate (a3) ​​having 8 to 22 carbon atoms and a hydroxyalkyl (meth)acrylate (b1), and reaction products of an aromatic polyisocyanate (a3) ​​having 8 to 22 carbon atoms and a polyalkylene glycol mono(meth)acrylate (b2).

[0031] Examples of reaction products between a chain-like aliphatic polyisocyanate (a1) having 4 to 20 carbon atoms and a hydroxyalkyl (meth)acrylate (b1) include the reaction product of ethylene diisocyanate and 2-hydroxyethyl (meth)acrylate, the reaction product of tetramethylene diisocyanate and 2-hydroxyethyl (meth)acrylate, the reaction product of hexamethylene diisocyanate and 2-hydroxyethyl (meth)acrylate, and the reaction product of dodecamethylene diisocyanate and 2-hydroxyethyl (meth)acrylate.

[0032] Examples of reaction products between a chain-like aliphatic polyisocyanate (a1) having 4 to 20 carbon atoms and polyalkylene glycol mono(meth)acrylate (b2) include the reaction product of ethylene diisocyanate and diethylene glycol mono(meth)acrylate, the reaction product of tetramethylene diisocyanate and diethylene glycol mono(meth)acrylate, the reaction product of hexamethylene diisocyanate and diethylene glycol mono(meth)acrylate, and the reaction product of dodecamethylene diisocyanate and diethylene glycol mono(meth)acrylate.

[0033] Examples of reaction products between an aromatic polyisocyanate (a3) ​​having 8 to 22 carbon atoms and a hydroxyalkyl (meth)acrylate (b1) include the reaction product of TDI and 2-hydroxyethyl (meth)acrylate.

[0034] Examples of reaction products between aromatic polyisocyanates (a3) ​​having 8 to 22 carbon atoms and polyalkylene glycol mono(meth)acrylates (b2) include reaction products between TDI and diethylene glycol mono(meth)acrylates.

[0035] The (meth)acrylate (B) having two urethane bonds in the present invention can be produced by reacting the polyisocyanate described above with a hydroxyl group-containing (meth)acrylate by a known method. In particular, producing a di(meth)acrylate having two urethane bonds by addition reaction between an aromatic polyisocyanate (a3) ​​having 8 to 22 carbon atoms and a hydroxyalkyl (meth)acrylate (b1) is preferable from the viewpoint of increasing the concentration and decreasing the viscosity of the polymer polyol. In the above addition reaction, a urethane catalyst may be used, and the same catalyst as those exemplified above can be used as the urethane catalyst.

[0036] Examples of diisocyanates (C) in the first invention of this application include linear aliphatic diisocyanates (c1) having 4 to 20 carbon atoms, alicyclic diisocyanates (c2) having 6 to 22 carbon atoms, and aromatic diisocyanates (c3) having 8 to 22 carbon atoms.

[0037] Examples of chain-like aliphatic diisocyanates (c1) having 4 to 20 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate.

[0038] Examples of alicyclic diisocyanates (C2) having 6 to 22 carbon atoms include cyclohexane-1,3-diylbismethylene diisocyanate, isophorone diisocyanate (IPDI), 2,4- or 2,6-methylcyclohexane diisocyanate (hydrogenated TDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, and methylcyclohexylene diisocyanate.

[0039] Examples of aromatic diisocyanates (C3) having 8 to 22 carbon atoms include 1,3- or 1,4-phenylenediisocyanate, 2,4- or 2,6-tolylenediisocyanate (toluene diisocyanate, TDI), 4,4'- or 2,4'-diphenylmethane diisocyanate (MDI), m- or p-xylylenediisocyanate (XDI), and α,α,α',α'-tetramethylxylylenediisocyanate (TMXDI).

[0040] These diisocyanates (C) are preferably aromatic diisocyanates (C3) having 8 to 22 carbon atoms, and more preferably 2,4- or 2,6-tolylene diisocyanate (toluene diisocyanate: TDI), from the viewpoint of reactivity with hydroxyl group-containing (meth)acrylates. Diisocyanate (C) may be used alone or in combination of two or more types.

[0041] In the present invention, each component of (meth)acrylate (A), (meth)acrylate (B), and diisocyanate (C) is determined by numerically integrating the peak areas corresponding to (A), (B), and (C) in the chromatogram obtained by measuring the polymer polyol dispersant raw material composition under the gel permeation chromatography (GPC) measurement conditions described below. Furthermore, if necessary, fractions corresponding to the retention time range of each peak are separated and LC-TOF-MS measurements are performed under the conditions described below to identify each component based on its mass (m / z).

[0042] The peak area ratios of the components (A), (B) and (C) are calculated by the following formula based on the total of these peak areas (AA+AB+AC), wherein the peak area (AA) corresponding to component (A), the peak area (AB) corresponding to component (B) and the peak area (AC) corresponding to component (C) are respectively obtained by numerical integration in a chromatogram measured using gel permeation chromatography. Peak area ratio of (A) (%) = 100 × AA / (AA+AB+AC) Peak area ratio of (B) (%) = 100 × AB / (AA+AB+AC) Peak area ratio of (C) (%) = 100 × AC / (AA+AB+AC)

[0043] <GPC Measurement Conditions> Columns: TSKgel SuperH4000, TSKgel SuperH3000 and TSKgel SuperH2000 (all manufactured by Tosoh Corporation) Column temperature: 40°C Detector: RI Solvent: tetrahydrofuran Flow rate: 0.6 ml / min Sample concentration: 0.25% Injection volume: 10 μl Standard: polyethylene oxide (manufactured by Tosoh Corporation; TSK STANDARD POLYETHYLENE OXIDE) Data processing device: SC-8020 (manufactured by Tosoh Corporation)

[0044] <LC-TOF-MS Measurement Conditions> Device: LC-QTOF manufactured by Waters; Column: Acquity UPLC BEH C18 (1.7 μm × 2.1 mm × 5 cm) Mobile phase A: methanol; Mobile phase B: 10 mM aqueous ammonium acetate solution / methanol = 80 / 20 Flow rate: 0.5 ml / min Column temperature: 40°C Injection volume: 0.5 μl Gradient conditions: A60% (0-1 min) → A80% (4-5 min) → A98% (9-13 min) → A60% (13.1-17 min) Detector: MS Ion source: ESI Mode: MSE Mass: 50-2500

[0045] The peak area ratio of the GPC for (meth)acrylate (A) having one isocyanate group and one urethane bond according to the first invention of this application is 70-84% when the sum of the peak areas corresponding to (A), (B), and (C) is taken as 100%. If the peak area ratio of (A) is less than 70%, the dispersion stability of the polymer particles becomes insufficient, making it easy for polymer particles to adhere or aggregate, and potentially increasing the amount of coarse particles. On the other hand, if the peak area ratio of (A) exceeds 84%, the concentration of the polymer polyol becomes insufficient.

[0046] The peak area ratio of the GPC of (meth)acrylate (B) having two urethane bonds in the first invention of this application is 15-20%, based on the peak area of ​​the GPC of the dispersant raw material composition. If the peak area ratio of (B) is less than 15%, the concentration of the polymer polyol will be insufficient, and it may also be disadvantageous from the viewpoint of dispersion stability. On the other hand, if the peak area ratio of (B) exceeds 20%, the viscosity of the polymer polyol may be insufficient.

[0047] The peak area ratio of the diisocyanate (C) in the GPC of the first invention of this application is 1 to 10%, when the sum of the peak areas corresponding to (A), (B), and (C) is taken as 100%. If the peak area ratio of (C) is less than 1%, the dispersion stability of the polymer particles will be insufficient, and the number of coarse particles may increase. On the other hand, if the peak area ratio of (C) exceeds 10%, the viscosity reduction of the polymer polyol may be insufficient.

[0048] In the production of polymer polyols, we found that the content of (meth)acrylate (A) and (meth)acrylate (B) in the polymer polyol dispersant raw material composition is an important control factor from the viewpoint of suppressing the adhesion or aggregation of polymer particles that may occur due to poor dispersion and reducing the content of coarse particles.

[0049] In other words, (meth)acrylate (A) can react with 3- to 6-valent polyols via isocyanate groups, and in the resulting dispersant for polymer polyols, it can form structural units derived from polyols into which (meth)acryloyl groups have been introduced via urethane bonds. As a result, these structural units are incorporated into polymer particles during polymerization, acting as so-called reactive dispersants (macromers) to contribute to the stabilization of the polymer particle surface and suppress the generation of coarse particles. In particular, it can contribute to ensuring dispersion stability under manufacturing conditions for monomer systems containing styrene or polymer polyols with a high polymer particle content.

[0050] Furthermore, since the (meth)acryloyl group has an ethylenically unsaturated bond, it can copolymerize with the styrene and the acrylonitrile. For this reason, the polymer particles may contain structural units derived from a polyol in which the (meth)acryloyl group is introduced via the urethane bond, as well as structural units derived from the styrene and the acrylonitrile, and may also contain structural units obtained by copolymerizing the (meth)acryloyl group with the styrene and the acrylonitrile. The presence of structural units obtained by copolymerizing the (meth)acryloyl group with the styrene and acrylonitrile can be confirmed using nuclear magnetic resonance spectroscopy, infrared spectroscopy, mass spectrometry, chromatography, or a combination thereof.

[0051] On the other hand, since diisocyanate (C) can react with a 3- to 6-valent polyol via an isocyanate group, it can act as a non-reactive dispersant having no (meth)acryloyl group in the resulting dispersant for polymer polyols. Accordingly, when used in combination with (A), it can suppress coalescence or aggregation between polymer particles and reduce the content of coarse particles.

[0052] However, if the content of both (A) and (C) is excessively large, it may increase the viscosity of the resulting dispersant for polymer polyols, and consequently the viscosity of the polymer polyol. Therefore, from the viewpoint of achieving both reduction of coarse particles and viscosity reduction, the contents of (A) and (C) are preferably controlled within the range specified in the present invention.

[0053] The isocyanate group content (NCO%) of the raw material composition for a dispersant for polymer polyols according to the first invention of the present application is defined as a value obtained by determining the mass of isocyanate groups (NCO groups) in a sample by the back titration method using di-n-butylamine, and dividing the mass by the mass of the sample. From the viewpoint of reducing the viscosity and increasing the solid concentration of the polymer polyol, NCO% is preferably 10 to 15%. NCO% (%) = (mass of NCO groups in the sample / mass of the sample) × 100 <Method for measuring NCO%> A sample is dissolved in a dimethylformamide solution of di-n-butylamine, and after reacting with NCO groups remaining in the sample, a dimethylformamide solution of bromophenol blue is added as an indicator, followed by titration with a methanolic solution of hydrochloric acid. Separately, a blank solution is titrated in the same manner except that no sample is contained. From these titration amounts, NCO% is calculated by the following formula. NCO% (%) = 0.042 × f × (Zb - Zp) / W Here, f is the titer of the titrant, Zp is the titration volume of the sample solution (mL), Zb is the titration volume of the blank solution (mL), and W is the sampled mass of the sample (g).

[0054] The method for producing the polymer polyol dispersant raw material composition of the first invention of this application is not particularly limited. For example, it can be produced by uniformly mixing (meth)acrylate (A) having one isocyanate group and one urethane bond, (meth)acrylate (B) having two urethane bonds, and diisocyanate (C) in a temperature range of 20 to 80°C using a known mechanical mixing method (a method using a mechanical stirrer, a magnetic stirrer, etc.). Alternatively, a dispersant raw material composition can be produced by dropwise adding (meth)acrylate (b) having one hydroxyl group to diisocyanate (C) and reacting it in a temperature range of 20 to 80°C to produce a dispersant raw material composition containing (meth)acrylate (A) having one isocyanate group and one urethane bond, (meth)acrylate (B) having two urethane bonds, and unreacted diisocyanate (C), which is a preferred production method from the viewpoint of productivity.

[0055] The second invention of this application is a dispersant for polymer polyols, which is a reaction product of the above-mentioned dispersant raw material composition of the first invention of this application and a 3- to 6-valent polyol, and contains a polyol in which (meth)acryloyl groups have been introduced via urethane bonds.

[0056] Examples of 3- to 6-valent polyols include 3- to 6-valent alcohols, compounds in which alkylene oxide (hereinafter sometimes abbreviated as AO) is added and polymerized to the 3- to 6-valent alcohols, and 3- to 6-valent compounds in which AO is added and polymerized to polyhydric phenols, amines, and polycarboxylic acids. Two or more of these may be used in combination.

[0057] Examples of trivalent to hexavalent alcohols include trivalent alcohols with 3 to 20 carbon atoms (aliphatic triols, e.g., glycerin, trimethylolpropane, trimethylolethane, and alkanetriols such as 1,2,6-hexanetriol), and polyvalent alcohols with 5 to 20 carbon atoms (aliphatic polyols, e.g., pentaerythritol, diglycerin, and dipentaerythritol).

[0058] Examples of polyvalent (3-6 valent) phenols include monocyclic polyvalent phenols such as pyrogallol and phloroglucin.

[0059] Examples of amines include those with 3 to 6 active hydrogen atoms, such as ammonia, and as aliphatic amines, alkanolamines with 2 to 20 carbon atoms (e.g., monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, and aminoethylethanolamine), alkylenediamines with 2 to 6 carbon atoms (e.g., ethylenediamine, propylenediamine, and hexamethylenediamine), and polyalkylene polyamines with 4 to 20 carbon atoms (dialkylentriamines to hexaalkyleneheptamines with 2 to 6 carbon atoms in the alkylene group, e.g., diethylenetriamine, triethylenetetramine).

[0060] Examples of polycarboxylic acids include aromatic polycarboxylic acids with 9 to 18 carbon atoms (such as trimellitic acid and pyromellitic acid, which are trivalent to hexavalent carboxylic acids).

[0061] When using a compound with a structure in which the above-mentioned AO is added polymerized as a 3- to 6-valent polyol, it is preferably a compound with a structure in which AO is added polymerized to a 3- to 6-valent alcohol, and more preferably a compound with a structure in which AO is added polymerized to at least one polyhydric alcohol selected from glycerin, trimethylolpropane, and pentaerythritol. Examples of AO in compounds with an addition polymerization structure include propylene oxide (hereinafter sometimes abbreviated as PO), ethylene oxide (hereinafter sometimes abbreviated as EO), 1,2-, 1,3-, 1,4-, or 2,3-butylene oxide, styrene oxide, and combinations of two or more of these (in the case of combinations, random addition, block addition, or combinations thereof are all acceptable). Preferably, the AO has 2 to 8 carbon atoms, more preferably PO and EO, and particularly preferably a compound obtained by adding PO followed by EO. The conditions under which AO is added are not particularly limited, and examples include compounds in which AO is added at 70 to 150°C in the presence of a commonly used alkaline catalyst (such as alkali metal hydroxide described later). Commercially available AO adducts may also be used.

[0062] In the second invention of this application, the weight percentage of the 3- to 6-valent polyol is preferably 95-99% by weight, and more preferably 96-98.5% by weight, based on the total weight of the constituent raw materials of the dispersant for polymer polyols, from the viewpoint of dispersion stability of polymer particles and viscosity of polymer polyols.

[0063] The viscosity of the polymer polyol dispersant of the second invention of this application at 25°C is preferably 1000 to 2000 mPa·s from the viewpoint of the dispersion stability of polymer particles and the viscosity of the polymer polyol. The viscosity of the polymer polyol dispersant at 25°C was measured using a Brookfield viscometer at 25°C according to the method described in JIS K 1557-5:2007.

[0064] The method for producing dispersants for polymer polyols is not particularly limited. For example, the dispersant raw material composition described in the first invention of this application and a 3- to 6-valent polyol can be uniformly mixed at a temperature range of 20 to 100°C using a known mechanical mixing method (such as a mechanical stirrer or a magnetic stirrer), and then subjected to an addition reaction. In the above addition reaction, a urethane catalyst may be used, and the same catalyst as those exemplified above can be used as the urethane catalyst.

[0065] The polymer polyol of the third invention of this application is a polymer in which polymer particles are dispersed in a polyol. The polymer particles are polymers obtained by polymerizing ethylenically unsaturated monomers (hereinafter also referred to as vinyl monomers). Preferably, the polymer particles contain structural units derived from a polyol in which (meth)acryloyl groups are introduced via urethane bonds contained in a dispersant for polymer polyols, and also contain structural units derived from styrene and acrylonitrile. Furthermore, it is preferable that the structural units are obtained by copolymerizing the (meth)acryloyl groups with styrene and acrylonitrile.

[0066] Examples of the vinyl monomer include aromatic vinyl monomers (b1), unsaturated nitriles (b2), (meth)acrylic acid esters (b3), other vinyl monomers (b4), and mixtures of two or more of these.

[0067] Examples of (b1) include styrene, α-methylstyrene, hydroxystyrene, and chlorostyrene. Examples of (b2) include acrylonitrile and methacrylonitrile.

[0068] Examples of (b3) include alkyl (meth)acrylates (alkyl group with 1 to 24 carbon atoms) (e.g., methyl (meth)acrylate, butyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, eicosyl (meth)acrylate, and docosyl (meth)acrylate, etc.), hydroxyalkyl (2 to 5 carbon atoms) (meth)acrylates (e.g., hydroxyethyl (meth)acrylate, etc.), and hydroxypolyoxyalkylene mono(meth)acrylates (e.g., (i) alkylene group with 2 to 4 carbon atoms, and (ii) polyoxyalkylene chain with a number-average molecular weight of 200 to 1000).

[0069] Examples of (b4) include ethylenically unsaturated carboxylic acids and their derivatives such as (meth)acrylic acid and (meth)acrylamide; alkenes such as ethylene, propylene and norbornene; alkadienes such as butadiene; chlorinated vinyl monomers such as vinylidene chloride; fluorinated vinyl monomers such as fluorine-containing (meth)acrylate; nitrogen-containing (meth)acrylates (e.g., diaminoethyl methacrylate and morpholinoethyl methacrylate); and vinyl-modified silicones.

[0070] The sum of (b1) and (b2) in the vinyl monomer is preferably 50 to 100% by weight, and more preferably 80 to 100% by weight. Also, (b3) is preferably 0 to 50% by weight, and more preferably 0 to 20% by weight. (b4) is preferably 0 to 10% by weight, and more preferably 0 to 5% by weight.

[0071] The weight ratio (St:ACN) of styrene (St) to acrylonitrile (ACN) in the vinyl monomer is not particularly limited, but can be set appropriately from the viewpoint of particle size and dispersion stability. [Examples]

[0072] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

[0073] The composition and symbols of the raw materials used in the examples and comparative examples are as follows. Diisocyanates: Coronate T-80 (TDI) [manufactured by Tosoh Corporation], Coronate T-100 (TDI) [manufactured by Tosoh Corporation]. 2-Hydroxyethyl methacrylate:Acryester HO [Manufactured by Mitsubishi Chemical Corporation] Polyol (PL1): A polyol obtained by adding PO to pentaerythritol, followed by the addition of EO, with a hydroxyl value of 28, a terminal EO content of 14% by weight, a weight-average molecular weight of 8000, and a viscosity of 1,300 mPa·s. Polyol (PL2): A polyol obtained by adding PO to pentaerythritol, followed by the addition of EO, with a hydroxyl value of 32, a terminal EO content of 12% by weight, a weight-average molecular weight of 7,000, and a viscosity of 1,100 mPa·s. Polyol (PL3): A polyol obtained by adding PO to glycerin, followed by the addition of EO, with a hydroxyl value of 37, a terminal EO content of 14% by weight, a weight-average molecular weight of 4500, and a viscosity of 800 mPa·s. Urethane catalyst: Manufactured by Nitto Kasei Co., Ltd.: Neostan U-600 Styrene: Manufactured by NS Styrene Monomer Co., Ltd. Acrylonitrile: Manufactured by Mitsubishi Chemical Corporation Radical polymerization initiator: 2,2'-Azobis(2-methylbutyronitrile), trade name "V-59", manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0074] <Example 1> [Dispersant raw material composition for polymer polyols (D-1)] In a four-necked flask equipped with a temperature controller, stirring blades, nitrogen inlet, and outlet, 343 parts by weight of toluene diisocyanate (Coronate T-80) was added as the initial charge. After purging with nitrogen, the mixture was heated to 80°C under a nitrogen atmosphere (until the reaction was complete) with stirring. Then, 258 parts by weight of 2-hydroxyethyl methacrylate was added, and the reaction was terminated when the NCO% reached the desired range. A polymer polyol dispersant raw material composition (D-1) was obtained, comprising (A) a methacrylate having one isocyanate group and one urethane bond, (B) a methacrylate having two urethane bonds represented by general formula (1), and (C) toluene diisocyanate.

[0075] <Example 2> [Dispersant raw material composition for polymer polyols (D-2)] In a four-necked flask equipped with a temperature controller, stirring blades, nitrogen inlet, and outlet, 328 parts by weight of toluene diisocyanate (Coronate T-80) was added as the initial charge. After purging with nitrogen, the mixture was heated to 70°C under a nitrogen atmosphere (until the reaction was complete) with stirring. Then, 255 parts by weight of 2-hydroxyethyl methacrylate was added, and the reaction was terminated when the NCO% reached the desired range. A polymer polyol dispersant raw material composition (D-2) was obtained, containing (A) a methacrylate having one isocyanate group and one urethane bond, (B) a methacrylate having two urethane bonds represented by general formula (1), and (C) toluene diisocyanate.

[0076] <Comparative Example 1> [Dispersant raw material composition for polymer polyols (D'-1)] In a four-necked flask equipped with a temperature controller, stirring blades, nitrogen inlet, and outlet, 755 parts by weight of toluene diisocyanate (Coronate T-80) was added as the initial charge. After purging with nitrogen, the mixture was heated to 80°C under a nitrogen atmosphere (until the reaction was complete) with stirring. Then, 245 parts by weight of 2-hydroxyethyl methacrylate was added, and the reaction was terminated when the NCO% reached the desired range. A polymer polyol dispersant raw material composition (D'-1) was obtained, containing (A) a methacrylate having one isocyanate group and one urethane bond, (B) a methacrylate having two urethane bonds represented by general formula (1), and (C) toluene diisocyanate.

[0077] <Comparative Example 2> [Dispersant raw material composition for polymer polyols (D'-2)] In a four-necked flask equipped with a temperature controller, stirring blades, nitrogen inlet, and outlet, 343 parts by weight of toluene diisocyanate (Coronate T-80) was added as the initial charge. After purging with nitrogen, the mixture was heated to 80°C under a nitrogen atmosphere (until the reaction was complete) with stirring. Then, 242 parts by weight of 2-hydroxyethyl methacrylate was added, and the reaction was terminated when the NCO% reached the desired range. A polymer polyol dispersant raw material composition (D'-2) was obtained, containing (A) a methacrylate having one isocyanate group and one urethane bond, (B) a methacrylate having two urethane bonds represented by general formula (1), and (C) toluene diisocyanate.

[0078] <Comparative Example 3> [Dispersant raw material composition for polymer polyols (D'-3)] In a four-necked flask equipped with a temperature controller, stirring blades, nitrogen inlet, and outlet, 330 parts by weight of toluene diisocyanate (Coronate T-80) and 0.20 parts by weight of urethane catalyst were added as initial charges. After purging with nitrogen, the mixture was heated to 80°C under a nitrogen atmosphere (until the reaction was complete) with stirring. Then, 301 parts by weight of 2-hydroxyethyl methacrylate was added, and the reaction was terminated when the NCO% reached the desired range. (A) A methacrylate having one isocyanate group and one urethane bond was obtained, (B) a methacrylate having two urethane bonds represented by general formula (1) was obtained, and (C) a polymer polyol dispersant raw material composition (D'-3) that does not contain toluene diisocyanate was obtained.

[0079] <Comparative Example 4> [Dispersant raw material composition for polymer polyols (D'-4)] In a four-necked flask equipped with a temperature controller, stirring blades, nitrogen inlet, and outlet, 410 parts by weight of toluene diisocyanate (Coronate T-100) was added as the initial charge. After purging with nitrogen, the mixture was heated to 70°C under a nitrogen atmosphere (until the reaction was complete) with stirring. Then, 260 parts by weight of 2-hydroxyethyl methacrylate was added, and the reaction was terminated when the NCO% reached the desired range. A polymer polyol dispersant raw material composition (D'-4) was obtained, containing (A) a methacrylate having one isocyanate group and one urethane bond, (B) a methacrylate having two urethane bonds represented by general formula (1), and (C) toluene diisocyanate.

[0080] <Comparative Example 5> [Dispersant raw material composition for polymer polyols (D'-5)] In a four-necked flask equipped with a temperature controller, stirring blades, nitrogen inlet, and outlet, 348 parts by weight of toluene diisocyanate (Coronate T-80) and 0.20 parts by weight of urethane catalyst were added as initial charges. After purging with nitrogen, the mixture was heated to 80°C under a nitrogen atmosphere (until the reaction was complete) with stirring. Then, 367 parts by weight of 2-hydroxyethyl methacrylate was added, and the reaction was terminated when the NCO% reached the desired range. (A) A methacrylate having one isocyanate group and one urethane bond was obtained, (B) A methacrylate having two urethane bonds represented by general formula (1) was obtained, and (C) A polymer polyol dispersant raw material composition (D'-5) that does not contain toluene diisocyanate was obtained.

[0081] <Comparative Example 6> [Dispersant raw material composition for polymer polyols (D'-6)] Into a 4-neck flask equipped with a temperature controller, a stirring blade, a nitrogen inlet and a nitrogen outlet, 343 parts by weight of toluene diisocyanate (Coronate T-80) was added as an initial charge. After nitrogen replacement, the temperature was raised to 80°C under stirring in a nitrogen atmosphere (until completion of the reaction). Subsequently, 209 parts by weight of 2-hydroxyethyl methacrylate was added, and the reaction was terminated when the NCO% reached the desired range. A dispersant raw material composition for polymer polyols (D'-6) was obtained, which comprises, as component (A), a methacrylate having one isocyanate group and one urethane bond, as component (B), a methacrylate having two urethane bonds represented by general formula (1), and as component (C), toluene diisocyanate.

[0082] Table 1 shows the measurement results of GPC peak area ratios and NCO% of (meth)acrylate (A) having one isocyanate group and one urethane bond, (meth)acrylate (B) having two urethane bonds, and diisocyanate (C) in Examples 1, 2 and Comparative Examples 1 to 6, respectively.

[0083] The peak area ratios of each component (A), (B) and (C) shown in Table 1 are the results of measurement and analysis performed in accordance with the <GPC measurement conditions> described above.

[0084]

Table 1

[0085] <Example 3> [Dispersant for polymer polyol (E-1)] Into a 4-neck flask equipped with a temperature controller, a stirring blade, a nitrogen inlet and a nitrogen outlet, 984 parts by weight of polyol (PL1) (a tetravalent polyol), 0.05 parts by weight of a urethanization catalyst and 16 parts by weight of the dispersant raw material composition for polymer polyol (D-1) were added as an initial charge. After nitrogen replacement, the temperature was raised to 75°C under stirring in a nitrogen atmosphere. Subsequently, the reaction was allowed to proceed at 75°C for 180 minutes, to obtain a dispersant for polymer polyol (E-1) comprising a reaction product of (D-1) and the tetravalent polyol. The viscosity of (E-1) at 25°C was 1480 mPa·s.

[0086] [Production of polymer polyols (P1)] In a four-necked flask equipped with a temperature controller, vacuum impeller, dropping pump, vacuum device, Liebig condenser, nitrogen inlet and outlet, 156 parts by weight of polyol (PL3), 11.3 parts by weight of polymer polyol dispersant (E-1), and 58 parts by weight of xylene were added, and the mixture was heated to 130°C while stirring. Next, a mixture of 267 parts by weight of polyol (PL3), 45.4 parts by weight of polymer polyol dispersant (E-1), 263 parts by weight of styrene, 175 parts by weight of acrylonitrile, and 4.4 parts by weight of radical polymerization initiator was continuously added dropwise at a rate of 4.2 parts by weight / min using a dropping pump, and polymerization was carried out for a further 30 minutes at 130°C after the addition was complete. Subsequently, unreacted monomers and xylene were removed by distillation under reduced pressure at 130°C to obtain polymer polyol (P1).

[0087] <Example 4> [Dispersant for polymer polyols (E-2)] In a four-necked flask equipped with a temperature controller, stirring blades, nitrogen inlet, and outlet, 984 parts by weight of polyol (PL1), 0.05 parts by weight of urethane catalyst, and 16 parts by weight of polymer polyol dispersant raw material composition (D-2) were added as initial charges. After purging with nitrogen, the mixture was heated to 75°C under a nitrogen atmosphere with stirring. The mixture was then reacted at 75°C for 180 minutes to obtain polymer polyol dispersant (E-2) containing the reaction product of (D-2) and a tetravalent polyol. The viscosity of (E-2) at 25°C was 1380 mPa·s.

[0088] [Production of polymer polyols (P2)] In a four-necked flask equipped with a temperature controller, vacuum impeller, dropping pump, vacuum device, Liebig condenser, nitrogen inlet and outlet, 156 parts by weight of polyol (PL3), 11.3 parts by weight of polymer polyol dispersant (E-2), and 58 parts by weight of xylene were added, and the mixture was heated to 130°C while stirring. Next, a mixture of 267 parts by weight of polyol (PL3), 45.4 parts by weight of polymer polyol dispersant (E-2), 263 parts by weight of styrene, 175 parts by weight of acrylonitrile, and 4.4 parts by weight of radical polymerization initiator was continuously added dropwise at a rate of 4.2 parts by weight / min using a dropping pump, and polymerization was carried out for a further 30 minutes at 130°C after the addition was complete. Subsequently, unreacted monomers and xylene were removed by distillation under reduced pressure at 130°C to obtain polymer polyol (P2).

[0089] <Comparative Example 7> [Dispersant for polymer polyols (E'-1)] In a four-necked flask equipped with a temperature controller, stirring blades, nitrogen inlet, and outlet, 982 parts by weight of polyol (PL2), 0.05 parts by weight of urethane catalyst, and 18.2 parts by weight of polymer polyol dispersant raw material composition (D'-1) were added as initial charges. After purging with nitrogen, the mixture was heated to 75°C under a nitrogen atmosphere with stirring. The mixture was then reacted at 75°C for 180 minutes to obtain polymer polyol dispersant (E'-1) containing the reaction product of (D'-1) and a tetravalent polyol. The viscosity of the obtained polymer polyol dispersant (E'-1) at 25°C was 4930 mPa·s.

[0090] [Production of polymer polyol (P'1)] In a four-necked flask equipped with a temperature controller, vacuum impeller, dropping pump, vacuum device, Liebig condenser, nitrogen inlet and outlet, 156 parts by weight of polyol (PL3), 11.3 parts by weight of polymer polyol dispersant (E'-1), and 58 parts by weight of xylene were added, and the mixture was heated to 130°C while stirring. Next, a mixture of 267 parts by weight of polyol (PL3), 45.4 parts by weight of polymer polyol dispersant (E'-1), 219 parts by weight of styrene, 219 parts by weight of acrylonitrile, and 4.4 parts by weight of radical polymerization initiator was continuously added dropwise at a rate of 4.2 parts by weight / min using a dropping pump, and polymerization was carried out for a further 30 minutes at 130°C after the addition was complete. Subsequently, unreacted monomers and xylene were removed by distillation under reduced pressure at 130°C to obtain polymer polyol (P'1).

[0091] <Comparative Example 8> [Dispersant for polymer polyols (E'-2)] The dispersant for polymer polyols (E'-2) was obtained by following the same procedure as in Example 3, except that the dispersant for polymer polyols raw material composition (D'-2) was used instead of the dispersant for polymer polyols raw material composition (D-1). The viscosity of the obtained dispersant for polymer polyols (E'-2) at 25°C was 1900 mPa·s.

[0092] [Production of polymer polyols (P'2)] In a four-necked flask equipped with a temperature controller, vacuum impeller, dropping pump, vacuum device, Liebig condenser, nitrogen inlet and outlet, 156 parts by weight of polyol (PL3), 11.3 parts by weight of polymer polyol dispersant (E'-2), and 58 parts by weight of xylene were added, and the mixture was heated to 130°C while stirring. Next, a mixture of 267 parts by weight of polyol (PL3), 45.4 parts by weight of polymer polyol dispersant (E'-2), 263 parts by weight of styrene, 175 parts by weight of acrylonitrile, and 4.4 parts by weight of radical polymerization initiator was continuously added dropwise at a rate of 4.2 parts by weight / min using a dropping pump, and polymerization was carried out for a further 30 minutes at 130°C after the addition was complete. Subsequently, unreacted monomers and xylene were removed by distillation under reduced pressure at 130°C to obtain polymer polyol (P'2).

[0093] <Comparative Example 9> [Dispersant for polymer polyols (E'-3)] The dispersant for polymer polyols (E'-3) was obtained by following the same procedure as in Example 3, except that the dispersant for polymer polyols raw material composition (D'-3) was used instead of the dispersant for polymer polyols raw material composition (D-1). The viscosity of the obtained dispersant for polymer polyols (E'-3) at 25°C was 1360 mPa·s.

[0094] [Production of polymer polyols (P'3)] In a four-necked flask equipped with a temperature controller, vacuum impeller, dropping pump, vacuum device, Liebig condenser, nitrogen inlet and outlet, 156 parts by weight of polyol (PL3), 11.3 parts by weight of polymer polyol dispersant (E'-3), and 58 parts by weight of xylene were added, and the mixture was heated to 130°C while stirring. Next, a mixture of 267 parts by weight of polyol (PL3), 45.4 parts by weight of polymer polyol dispersant (E'-3), 263 parts by weight of styrene, 175 parts by weight of acrylonitrile, and 4.4 parts by weight of radical polymerization initiator was continuously added dropwise at a rate of 4.2 parts by weight / min using a dropping pump, and polymerization was carried out for a further 30 minutes at 130°C after the addition was complete. Subsequently, unreacted monomers and xylene were removed by distillation under reduced pressure at 130°C to obtain polymer polyol (P'3).

[0095] <Comparative Example 10> [Dispersant for polymer polyols (E'-4)] The dispersant for polymer polyols (E'-4) was obtained by following the same procedure as in Example 3, except that the dispersant for polymer polyols raw material composition (D'-4) was used instead of the dispersant for polymer polyols raw material composition (D-1). The viscosity of the obtained dispersant for polymer polyols (E'-4) at 25°C was 1800 mPa·s.

[0096] [Production of polymer polyols (P'4)] In a four-necked flask equipped with a temperature controller, vacuum impeller, dropping pump, vacuum device, Liebig condenser, nitrogen inlet and outlet, 156 parts by weight of polyol (PL3), 11.3 parts by weight of polymer polyol dispersant (E'-4), and 58 parts by weight of xylene were added, and the mixture was heated to 130°C while stirring. Next, a mixture of 267 parts by weight of polyol (PL3), 45.4 parts by weight of polymer polyol dispersant (E'-4), 263 parts by weight of styrene, 175 parts by weight of acrylonitrile, and 4.4 parts by weight of radical polymerization initiator was continuously added dropwise at a rate of 4.2 parts by weight / min using a dropping pump, and polymerization was carried out for a further 30 minutes at 130°C after the addition was complete. Subsequently, unreacted monomers and xylene were removed by distillation under reduced pressure at 130°C to obtain polymer polyol (P'4).

[0097] <Comparative Example 11> [Dispersant for polymer polyols (E'-5)] The dispersant for polymer polyols (E'-5) was obtained by following the same procedure as in Example 3, except that the dispersant for polymer polyols raw material composition (D'-5) was used instead of the dispersant for polymer polyols raw material composition (D-1). The viscosity of the obtained dispersant for polymer polyols (E'-5) at 25°C was 1160 mPa·s.

[0098] [Production of polymer polyol (P'5)] In a four-necked flask equipped with a temperature controller, vacuum impeller, dropping pump, vacuum device, Liebig condenser, nitrogen inlet and outlet, 156 parts by weight of polyol (PL3), 11.3 parts by weight of polymer polyol dispersant (E'-5), and 58 parts by weight of xylene were added and the mixture was heated to 130°C under stirring. Then, a mixture of 267 parts by weight of polyol (PL3), 45.4 parts by weight of polymer polyol dispersant (E'-5), 263 parts by weight of styrene, 175 parts by weight of acrylonitrile, and 4.4 parts by weight of radical polymerization initiator was continuously added dropwise using a dropping pump at a rate of 4.2 parts by weight / min. As a result, the mixture solidified, and polymer polyol (P'5) with dispersed polymer particles could not be obtained. Therefore, no evaluation was performed.

[0099] <Comparative Example 12> [Dispersant for polymer polyols (E'-6)] The dispersant for polymer polyols (E'-6) was obtained in the same manner as in Example 3, except that the dispersant for polymer polyols raw material composition (D'-6) was used instead of the dispersant for polymer polyols raw material composition (D-1). The viscosity of the obtained dispersant for polymer polyols (E'-6) at 25°C was 2420 mPa·s.

[0100] [Production of polymer polyol (P'6)] In a four-necked flask equipped with a temperature controller, vacuum impeller, dropping pump, vacuum device, Liebig condenser, nitrogen inlet and outlet, 156 parts by weight of polyol (PL3), 11.3 parts by weight of polymer polyol dispersant (E'-6), and 58 parts by weight of xylene were added and the mixture was heated to 130°C while stirring. Next, a mixture of 267 parts by weight of polyol (PL3), 45.4 parts by weight of polymer polyol dispersant (E'-6), 263 parts by weight of styrene, 175 parts by weight of acrylonitrile, and 4.4 parts by weight of radical polymerization initiator was continuously added dropwise at a rate of 4.2 parts by weight / min using a dropping pump, and polymerization was carried out for a further 30 minutes at 130°C after the addition was complete. Subsequently, unreacted monomers and xylene were removed by distillation under reduced pressure at 130°C to obtain polymer polyol (P'6).

[0101] The raw material compositions for each of the polymer polyol dispersants (E-1) to (E-2) and (E'-1) to (E'-6) are shown in Table 2.

[0102] [Table 2]

[0103] For each of the polymer polyols (P1) to (P2), (P'1) to (P'4), and (P'6), the polymer particle content and viscosity at 25°C were measured. Furthermore, for each of the polymer polyols (P1) to (P2), (P'1) to (P'4), and (P'6), a portion was extracted, diluted with polyol (PL3), and the polymer particle content was measured when the viscosity at 25°C was 5000 mPa·s. Furthermore, for each of the polymer polyols (P1) to (P2), (P'1) to (P'4), and (P'6), a portion was taken and diluted with polyol (PL3), and the viscosity at 25°C, the median diameter of the polymer particles, and the coarse particle content were measured when the polymer particle content was 45% by weight. The results are shown in Table 3. The viscosity at 25°C, polymer particle content, median diameter of polymer particles, and coarse particle content were measured using the following methods.

[0104] [Table 3]

[0105] <25℃ viscosity> Viscosity at 25°C was measured using a Brookfield viscometer according to the method described in JIS K 1557-5:2007 (using rotor No. 3, measured at 12 rpm if viscosity was 10,000 mPa·s or less, and at 6 rpm if viscosity exceeded 10,000 mPa·s).

[0106] <Polymer particle content> Approximately 5 g of polymer polyol was accurately weighed into a 50 ml centrifuge tube and designated as the polymer polyol weight (W1). 50 g of methanol was added for dilution, and the mixture was centrifuged at 18,000 rpm for 60 minutes at 20°C using a refrigerated centrifuge [model: H-9R, manufactured by Kokusan Co., Ltd.]. The supernatant was removed using a glass pipette. 50 g of methanol was added to the residual precipitate for dilution, and the same centrifugation and supernatant removal procedure was repeated three more times. The residual precipitate in the centrifuge tube was dried under reduced pressure at 3-4 kPa at 80°C for 3 hours, and the weight of the dried precipitate was determined to be (W2). The value calculated using the following formula was designated as the polymer particle content (weight %). Polymer particle content (wt%)=(W2)×100 / (W1)

[0107] <Median diameter of polymer particles> 30 ml of methanol was placed in a 50 ml glass beaker, 2 mg of polymer polyol was added, and the mixture was stirred using a magnetic stirrer with a 2 cm long diameter and 0.5 cm short diameter for 3 minutes at 400 rpm to obtain a homogeneous solution. After mixing, the mixture was placed in a measurement cell within 5 minutes, and the median diameter based on volume was measured using a laser diffraction / scattering particle size distribution analyzer [model: LA-750, manufactured by Horiba, Ltd.].

[0108] <Coarse particle content> Approximately 300 g of finely dispersed polyol was accurately weighed into a 1 L beaker to obtain the weight of the finely dispersed polyol (W3). To this, 300 g of methanol, which had been previously filtered through an industrial woven wire mesh with a mesh size of 0.10 mm (JIS G3556, the same applies hereafter) to remove impurities, was added to obtain a homogeneous solution. The homogeneous solution was filtered through an industrial woven wire mesh with a mesh size of 0.10 mm, and any remaining impurities on the mesh were washed with 300 g of methanol, which had been previously used to remove impurities. The washed impurities were dried in a circulating air dryer at 70°C for 30 minutes, and the weight of the dried impurities was measured and taken as the weight of the impurities (W4) (weighed to an accuracy of 4 decimal places; unit: g). The value calculated using the following formula was taken as the content of polymer particles with a particle size of 0.10 mm or larger in the finely dispersed polyol (coarse particle content). Coarse particle content (ppm)=(W4)×1000000 / (W3) [Industrial applicability]

[0109] The polymer polyol dispersant raw material composition of the present invention is useful as a raw material for producing polymer polyol dispersants. Furthermore, the polymer polyol dispersant of the present invention is useful for obtaining polymer polyols (fine particle dispersed polyols) that contain a high concentration of polymer particles and have low viscosity when used in the polymerization of ethylenically unsaturated monomers in polyols. The polymer polyol of the present invention is particularly useful in the production of polyurethane foams such as flexible mold foams and slab foams. It can also be suitably used in molding by reaction injection molding.

Claims

1. A dispersant raw material composition for polymer polyols, comprising (meth)acrylate (A) having one isocyanate group and one urethane bond, (meth)acrylate (B) having two urethane bonds, and diisocyanate (C), wherein, in a chromatogram measured using a gel permeation chromatograph, when the sum of the peak areas corresponding to (meth)acrylate (A), (meth)acrylate (B), and diisocyanate (C) is taken as 100%, the peak area ratio of (meth)acrylate (A) is 70-84%, the peak area ratio of (meth)acrylate (B) is 15-20%, and the peak area ratio of diisocyanate (C) is 1-10%.

2. The polymer polyol dispersant raw material composition according to claim 1, wherein the (meth)acrylate (B) is a compound represented by the following general formula (1). 【Chemistry 1】 [In general formula (1), R １ [where n1 represents a hydrogen atom or a methyl group, n1 and n2 represent the same or different integers from 1 to 5, and X represents an alkylene group or phenylene group in which the hydrogen atom may be substituted with an alkyl group having 1 to 30 carbon atoms]

3. The dispersant raw material composition for polymer polyols according to claim 1, wherein the diisocyanate (C) is toluene diisocyanate.

4. A dispersant for polymer polyols, comprising a reaction product of a polymer polyol dispersant raw material composition according to any one of claims 1 to 3 and a polyol with a 3- to 6-valent pH, wherein the polyol has a (meth)acryloyl group introduced via a urethane bond.

5. A polymer polyol in which polymer particles containing structural units derived from a polyol in which a (meth)acryloyl group is introduced via a urethane bond contained in the dispersant for polymer polyols described in claim 4, and which also contain structural units derived from styrene and acrylonitrile, wherein the structural units are obtained by copolymerizing the (meth)acryloyl group with the styrene and the acrylonitrile.

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