JP2013227491A - Method for producing polymer polyol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a conventional method uses a high-cost aldehyde scavenger and reduces the cutting elongation of a flexible polyurethane foam, and in another conventional method, productivity decreases because of addition of man-hour for steaming and a flexible polyurethane foam becomes deformed when the foam is steamed immediately after molding so as to increase productivity.SOLUTION: A method for producing a polymer polyol includes a step (I) of polymerizing an ethylenically unsaturated compound (E) in a polyol (PL) in the presence of a radical polymerization initiator (K) and a dispersant (D), and a step (II) of distilling away the unreacted ethylenically unsaturated compound, wherein the gas phase oxygen concentration in the step (I) is 10-300 ppm and the aldehyde content in the resulting polymer polyol is ≤600 ppm on the basis of the weight of the polymer polyol.

Description

  The present invention relates to a method for producing a polymer polyol.

The polymer polyol is used for the purpose of improving physical properties such as increasing the compression hardness and durability of a flexible polyurethane foam, and is obtained by polymerizing an ethylenically unsaturated compound in a polyol in the presence of a polymerization initiator. In addition, flexible polyurethane foam is used in various applications such as automobile interior materials and furniture materials. In recent years, in sealed spaces such as automobiles and houses, it has been desired to reduce the volatile organic compound quality (hereinafter referred to as VOC) represented by aldehydes in consideration of the influence on the human body. On the other hand, polymer polyol, which is a raw material for flexible polyurethane foam, produces aldehydes as a by-product in the production process, but an effective coping method for suppressing aldehyde by-product has not been proposed.
Therefore, as a coping method, in order to reduce VOC of the flexible polyurethane foam, a method of mixing an aldehyde scavenger in the polyol (see Patent Document 1) and a method of applying water vapor to the flexible polyurethane foam are known (patents). Reference 2).

JP 2006-182825 A JP 2008-274198 A

However, the method of Patent Document 1 has a high cost of the aldehyde scavenger and lowers the cutting elongation of the flexible polyurethane foam. In the method of Patent Document 2, the man-hour for applying water vapor increases and the productivity decreases, and the productivity increases. If the water vapor is applied immediately after forming the flexible polyurethane foam, the foam will be deformed.
An object of the present invention is to provide a method for producing a polymer polyol having a low content of aldehydes that solves these problems.

That is, in the method for producing a polymer polyol of the present invention, an ethylenically unsaturated compound (E) is polymerized in a polyol (PL) in the presence of a radical polymerization initiator (K) and a dispersant (D) (I ) And the step (II) for distilling off the unreacted ethylenically unsaturated compound, wherein the gas phase oxygen concentration in the step (I) is 10 to 300 ppm, and in the resulting polymer polyol It is summarized that the aldehyde content of is 600 ppm or less based on the weight of the polymer polyol.
In the method for producing a flexible polyurethane foam of the present invention, a polyurethane foam is produced by reacting a polyol component and an isocyanate component in the presence of at least one additive selected from a catalyst, a foaming agent and a foam stabilizer. It is a method, Comprising: The polyol component contains 10-100 mass% of polymer polyols obtained by said manufacturing method based on the weight of a polyol component.
Moreover, the gist is that the flexible polyurethane foam of the present invention is obtained by the above production method.

  By the production method of the present invention, a polymer polyol having a low aldehyde content is obtained. In addition, the flexible polyurethane foam of the present invention using this has a low aldehyde content without using an expensive aldehyde scavenger, without being exposed to water vapor, and is excellent in mechanical properties such as cutting elongation.

  In this invention, the well-known polyol used for manufacture of a polymer polyol can be used for polyol (PL). For example, at least 2 (preferably 2 to 8 from the viewpoint of physical properties of flexible polyurethane foam) active hydrogen-containing compounds (polyhydric alcohol, polyhydric phenol, amine, polycarboxylic acid, phosphoric acid, etc.) are alkylene. Examples thereof include a compound (PL1) having a structure to which an oxide is added and a mixture thereof. From the viewpoint of the productivity of polyurethane foam (particularly flexible polyurethane foam), among these, a compound having a structure in which an alkylene oxide is added to a polyhydric alcohol is preferable.

  Examples of polyhydric alcohols include dihydric alcohols having 2 to 20 carbon atoms (aliphatic diols such as ethylene glycol, propylene glycol, 1,3- and 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol. And alicyclic diols such as cycloalkylene glycol such as cyclohexanediol and cyclohexanedimethanol), trihydric alcohols having 3 to 20 carbon atoms (aliphatic triols such as glycerin, trimethylolpropane and trimethylol) Alkanetriols such as ethane and hexanetriol); 4 to 8 or more polyhydric alcohols having 5 to 20 carbon atoms (aliphatic polyols such as pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin, Such as pentaerythritol, intramolecular or intermolecular dehydration products of alkane polyols and alkane triols; and sucrose, glucose, mannose, fructose, sugars and their derivatives such as methyl glucoside) and the like.

  Examples of the polyhydric phenol include monocyclic polyhydric phenols such as pyrogallol, hydroquinone, and phloroglucin; bisphenols such as bisphenol A, bisphenol F, and bisphenol sulfone; condensates (novolacs) of phenol and formaldehyde.

As the amine, ammonia; as the aliphatic amine, an alkanolamine having 2 to 20 carbon atoms (for example, monoethanolamine, diethanolamine, isopropanolamine and aminoethylethanolamine), an alkylamine having 1 to 20 carbon atoms (for example, n- Butylamine and octylamine), alkylenediamines having 2 to 6 carbon atoms (for example, ethylenediamine, propylenediamine and hexamethylenediamine), polyalkylenepolyamines (dialkylenetriamine to hexaalkyleneheptamine having 2 to 6 carbon atoms in the alkylene group), For example, diethylenetriamine and triethylenetetramine).
In addition, aromatic mono- or polyamines having 6 to 20 carbon atoms (for example, aniline, phenylenediamine, tolylenediamine, xylylenediamine, diethyltoluenediamine, methylenedianiline and diphenyletherdiamine); alicyclic having 4 to 20 carbon atoms Examples include amines (isophorone diamine, cyclohexylene diamine, and dicyclohexyl methane diamine); heterocyclic amines having 4 to 20 carbon atoms (for example, aminoethylpiperazine).

  Examples of the polycarboxylic acid include aliphatic polycarboxylic acids having 4 to 18 carbon atoms (succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, etc.), and aromatic polycarboxylic acids having 8 to 18 carbon atoms (terephthalic acid, Isophthalic acid and the like), and a mixture of two or more thereof.

  As the alkylene oxide to be added to the active hydrogen-containing compound, those having 2 to 8 carbon atoms are preferable from the viewpoint of the physical properties of polyurethane foam (particularly flexible polyurethane foam), ethylene oxide (hereinafter abbreviated as EO), 1, 2-propylene oxide (hereinafter abbreviated as PO), 1,2-, 1,3-, 1,4- and 2,3-butylene oxide (hereinafter abbreviated as BO), styrene oxide, and the like Or a combination of two or more (block and / or random addition). From the viewpoint of the physical properties of polyurethane foam (particularly flexible polyurethane foam), PO or a combination of PO and PO and EO (EO content of 25% or less) is preferable. In the above and the following, “%” means “% by weight” unless otherwise specified.

Specific examples of the polyol (PL1) include those obtained by adding PO to the active hydrogen-containing compound and those obtained by adding PO and another alkylene oxide (hereinafter abbreviated as AO) in the following manner, or Examples include esterified products of these addition compounds with polycarboxylic acid or phosphoric acid.
(1) Block added in the order of PO-AO (2) Block added in the order of PO-AO-PO-AO (3) Block added in the order of AO-PO-AO (4) PO- Block addition in the order of AO-PO (5) Random addition product in which PO and AO are mixed and added (6) Random or block addition in the order described in US Pat. No. 4,226,756 The hydroxyl group of (PL1) The equivalent is preferably 200 to 4,000, more preferably 400 to 3,000, from the viewpoint of physical properties of polyurethane foam (particularly flexible polyurethane foam). It is also preferable to use two or more kinds of (PL1) in combination so that the hydroxyl equivalent is within this range.

As the polyol (PL), another polyol (PL2) can be used in combination with the (PL1). In this case, the use ratio (weight ratio) of (PL1) / (PL2) is preferably 100/0 to 80/20 from the viewpoint of the physical properties of the polyurethane foam (particularly, flexible polyurethane foam).
Examples of (PL2) include polymer polyols such as polyester polyols and diene polyols, and mixtures thereof.

  As the polyester polyol, the polyhydric alcohol and / or polyether polyol [ethylene glycol, diethylene glycol, propylene glycol, 1,3- or 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, etc. Polyhydric alcohols or mixtures thereof with trihydric or higher polyhydric alcohols such as glycerin and trimethylolpropane, and alkylene oxide low-mole (1 to 10 mol) adducts of these polyhydric alcohols], and the polycarboxylic acid Alternatively, condensation with an anhydride or an ester-forming derivative such as a lower alkyl (carbon number of alkyl group: 1 to 4) ester (for example, adipic acid, sebacic acid, maleic anhydride, phthalic anhydride, dimethyl terephthalate, etc.) Reactant or the above-mentioned polyvalent alcohol And / or a condensation reaction product of the polyether polyol with the carboxylic acid anhydride and the alkylene oxide; an addition reaction product of the condensation reaction product with an alkylene oxide (EO, PO, etc.); a polylactone polyol such as the polyhydric alcohol is started. Examples of the agent include those obtained by ring-opening polymerization of a lactone (such as ε-caprolactone); polycarbonate polyols such as a reaction product of the polyhydric alcohol and alkylene carbonate.

  Furthermore, diene polyols such as polybutadiene polyol and hydrogenated products thereof; hydroxyl group-containing vinyl polymers such as acrylic polyols; natural oil polyols such as castor oil; modified products of natural oil polyols, and the like.

  These polyols (PL2) are preferably 2 to 8, more preferably 3 to 8 hydroxyl groups, and physical properties of polyurethane foam (particularly flexible polyurethane foam) from the viewpoint of physical properties of polyurethane foam (particularly flexible polyurethane foam). From the above viewpoint, it preferably has a hydroxyl group equivalent of 500 to 4,000, more preferably 700 to 3,000.

  The number average molecular weight of the polyol (PL) (according to gel permeation chromatograph (GPC), the same applies to the following number average molecular weight unless otherwise specified) is preferably 1,500 or more, more preferably 1,500 to 15, 000, particularly preferably 1,800 to 12,000, most preferably 2,000 to 9,000. When the number average molecular weight is 1,500 or more, it is preferable from the viewpoint of foaming property of the polyurethane foam, and when it is 15,000 or less, the viscosity becomes low and the handling property of the polymer polyol is preferable. The hydroxyl equivalent of (PL) is preferably 500 to 4,000, more preferably 700 to 3,000, from the viewpoint of the physical properties of polyurethane foam (particularly flexible polyurethane foam).

  As the ethylenically unsaturated compound (E), styrene (hereinafter abbreviated as St), acrylonitrile (hereinafter abbreviated as ACN), other ethylenically unsaturated monomers (e), and the like can be used. As (E), from the viewpoint of dispersibility of polymer particles, the total content of St and / or ACN is preferably 50 to 100% by weight based on the weight of (E), more preferably 60 to 100% by weight, and more preferably 70-100% by weight.

  The St content is preferably from 20 to 90% by weight, more preferably from 25 to 80% by weight, and still more preferably from the viewpoint of discoloration of polyurethane foam (particularly flexible polyurethane foam), based on the weight of (E). 30 to 75% by weight, most preferably 50 to 70% by weight.

  The content of ACN is preferably 10 to 80% by weight, more preferably 20 to 75% by weight, and still more preferably 25 to 70% by weight based on the total weight of (E) from the same viewpoint as described above. Most preferably, it is 30 to 50% by weight.

  Other ethylenically unsaturated monomers (e) are those having 2 or more carbon atoms (hereinafter abbreviated as C) and a number average molecular weight of less than 1,000, and can be copolymerized with St and / or ACN. There is no particular limitation, and the following monofunctional ones {unsaturated nitrile (e1), aromatic ring-containing monomer (e2), (meth) acrylic acid ester (e3), unsaturated alcohol alkylene oxide adduct (e4) and Other ethylenically unsaturated monomers (e5)} and polyfunctional monomers (e6) can be used. These may be used alone or in combination of two or more.

Examples of (e1) include methacrylonitrile.
Examples of (e2) include α-methylstyrene, hydroxystyrene, and chlorostyrene.
(E3) includes (meth) acrylic acid alkyl esters such as methyl (meth) acrylate, butyl (meth) acrylate and docosyl (meth) acrylate (alkyl group is C1-24); hydroxypolyoxyalkylene (alkylene group is C2 -8) Mono (meth) acrylate and the like.
In addition, (meth) acrylic acid ester means acrylic acid ester and / or methacrylic acid ester. The same notation is used for (meth) acrylic acid and (meth) allyl in the following.

  As the unsaturated alcohol (e4), a terminal unsaturated alcohol is preferably used. As for carbon number of unsaturated alcohol, 3-12 are preferable from a dispersible viewpoint of a polymer particle. Examples of terminal unsaturated alcohols include allyl alcohol, 2-buten-1-ol, 3-buten-2-ol, 3-buten-1-ol, and 1-hexen-3-ol.

In (e4), examples of AO added to the unsaturated alcohol include C2 to C12. For example, EO, PO, 1,2-BO, 1,4-BO, and a combination of two or more thereof (random) Addition and / or block addition). AO is preferably PO and / or EO from the viewpoints of dispersion stability and viscosity.
The number of moles of AO added is preferably 1 to 9, more preferably 1 to 6, and still more preferably 1 to 3, from the viewpoints of dispersion stability and viscosity.

  Other ethylenically unsaturated monomers (e5) are preferably C2-24 ethylenically unsaturated monomers, vinyl group-containing carboxylic acids such as (meth) acrylic acid; aliphatic hydrocarbon monomers such as ethylene and propylene; Fluorine-containing vinyl monomers such as fluorooctylethyl methacrylate and perfluorooctylethyl acrylate; nitrogen-containing vinyl monomers such as diaminoethyl methacrylate and morpholinoethyl methacrylate; vinyl-modified silicones; cyclic olefins and cyclic dienes such as norbornene, cyclopentadiene and norbornadiene; etc. Is mentioned.

  As the polyfunctional monomer (e6), a C8-40 polyfunctional monomer is preferable, and divinylbenzene, ethylene di (meth) acrylate, polyalkylene oxide glycol di (meth) acrylate, pentaerythritol triallyl ether, and trimethylolpropane tri (meta). ) Acrylate and the like.

  Of (e1) to (e6), from the viewpoint of the viscosity of the polymer polyol and the physical properties of the polyurethane foam (particularly, flexible polyurethane foam), (e3), (e4) and (e6) are preferred, and (e4) and (E6), particularly preferably PO and / or EO adducts of terminal unsaturated alcohols and bifunctional monomers, most preferably PO adducts of allyl alcohol and divinylbenzene.

  The content of (e4) based on the weight of (E) is preferably 2% by weight or less, more preferably 1% by weight or less, from the viewpoint of improving the physical properties of the polyurethane foam (particularly the hardness of the flexible polyurethane foam). Preferably it is 0 weight%.

  Examples of the radical polymerization initiator (K) include azo compounds and peroxides {things described in JP 2005-162791 A, JP 2004-002800 A (corresponding US patent application: US 2005/245724 A1)}. Can be used. In addition, the 10-hour half-life temperature of (K) is preferably 30 to 150 ° C., more preferably 40 to 140 ° C., particularly preferably from the viewpoint of the polymerization rate and polymerization time of (E) and the productivity of the polymer polyol. 50-130 ° C.

  The amount (% by weight) used of (K) is 0.05 to 20 based on the total weight of (E) from the viewpoint of the degree of polymerization of (E) and the physical properties of the resulting polyurethane foam (particularly flexible polyurethane foam). More preferably, it is 0.1-5, Most preferably, it is 0.2-2.

As the dispersant (D), a dispersant having a Mn of 1,000 or more (preferably 1,000 to 10,000), for example, a known dispersant used in the production of a polymer polyol {Japanese Patent Laid-Open No. 2005-162791 , JP 2004-002800 (corresponding to US Patent Application: US2005 / 245724 A1), etc. can be used, and (D) is an ethylenically unsaturated copolymerizable with St or ACN. And reactive dispersants having groups and non-reactive dispersants that do not copolymerize with St or ACN.
In the present invention, the reactive dispersant containing an ethylenically unsaturated group has a Mn of 1,000 or more, and is distinguished from an ethylenically unsaturated compound (E) having a Mn of less than 1,000.

Specific examples of the dispersant (D) include the following.
[1] A modified polyol obtained by reacting at least a part of the hydroxyl groups of the polyol (PL) with an alkylene dihalide such as methylene dihalide (described in JP-A-07-196749);
[2] Ethylenically unsaturated group-containing modified polyol obtained by further reacting the modified polyol of [1] with an ethylenically unsaturated group-containing compound {JP 08-333508 A, JP 2004-002800 A (corresponding) US Patent Application: US2005 / 245724 A1)};
[3] A difference in solubility parameter with a polymer of an ethylenically unsaturated compound having two or more (PL) affinity segments having a solubility parameter difference with a polyol (PL) of 1 or less is a side chain. Graft type polymer having a polymer fine particle (JR) affinity segment as the main chain (as described in JP-A-05-059134;
[4] Weight average molecular weight (hereinafter abbreviated as Mw), at least a part of which is soluble in polyol (PL) [measurement is by gel permeation chromatography (GPC) method. ] Of 1,000 to 30,000 vinyl-based oligomers and dispersants using ethylenically unsaturated group-containing modified polyols obtained by reacting these oligomers and modified polyols of [1] (Japanese Patent Laid-Open No. 09-77968) As described);
[5] A dispersant comprising a nitrogen-containing bond-containing unsaturated polyol in which a polyol (PL) and a monofunctional active hydrogen-containing compound having at least one ethylenically unsaturated group are bonded via a polyisocyanate No. 2002-308920 (corresponding to US Pat. No. 6,756,414)
Among these, [2], [4] and [5] are preferable from the viewpoint of the particle diameter of the polymer fine particles (JR), and [5] is particularly preferable.

  From the viewpoint of the particle diameter of the polymer fine particles (JR) and the viscosity of the polymer polyol, the amount of use (% by weight) of the dispersant (D) is preferably 2 to 20, more preferably, based on the weight of the polyol (PL). Is 5-15.

In the polymerization, a diluting solvent (c) may be used if necessary. (C) includes C6-10 aromatic hydrocarbons (toluene, xylene, etc.); C5-15 saturated aliphatic hydrocarbons (hexane, heptane, normal decane, etc.); C5-30 unsaturated aliphatic hydrocarbons (Octene, nonene, decene, etc.); and other known solvents (for example, those described in JP-A-2005-162791). Among (c), an aromatic hydrocarbon is preferable from the viewpoint of the viscosity of the polymer polyol.
The use amount (% by weight) of (c) is preferably from 0.1 to 50, more preferably from the viewpoint of the viscosity of the polymer polyol and the mechanical properties of the polyurethane, based on the total weight of the ethylenically unsaturated compound (E). Is 1-40. (C) may remain in the polymer polyol after the completion of the polymerization reaction, but it is desirable to remove by vacuum stripping after the polymerization reaction from the viewpoint of the physical properties of the polyurethane foam (particularly, flexible polyurethane foam).

In the polymerization, a chain transfer agent (g) may be used if necessary. (G) is a chain transfer agent such as C1-20 aliphatic thiol (n-dodecanethiol, mercaptoethanol, etc.) {JP 2005-162791 A, JP 2004-002800 A (corresponding US patent application: US 2005). / 245724 A1)}.
From the viewpoint of the viscosity of the polymer polyol and the physical properties of the resulting polyurethane foam (especially flexible polyurethane foam), the amount (% by weight) of (g) is 0. 0, based on the total weight of the ethylenically unsaturated compound (E). 01-2 are preferable, More preferably, it is 0.1-1.

  The polymer fine particle (JR) content (% by weight) in the polymer polyol is preferably from 20 to 75, more preferably from 30 to 50, in view of foam hardness and prevention of aggregation of (JR) in the polymer polyol. More preferably, it is 35-45. The (JR) content is measured by the following method.

<Content of polymer particles (JR)>
About 5 g of polymer polyol is precisely weighed in a 50 ml centrifuge tube for centrifugal separation made of SUS, and the weight is set to the weight of polymer polyol (W1). Dilute with 15 g of methanol. Using a cooling centrifuge [model number: GRX-220, manufactured by Tommy Seiko Co., Ltd.], centrifuge at 18,000 rpm for 60 minutes at 20 ° C. The supernatant is removed using a glass pipette. The operation of adding 15 g of methanol to the residual sediment, diluting, and centrifuging in the same manner as above to remove the supernatant is repeated three more times. The residual sediment in the centrifuge tube is dried under reduced pressure at 2,666-3,999 Pa at 60 ° C. for 60 minutes, the dried sediment is weighed, and the weight is defined as (W2). The value calculated by the following formula is the polymer particle content (% by weight).

Polymer particle content (% by weight) = (W2) × 100 / (W1)

From the viewpoint of moldability, the viscosity (mPa · s) of the polymer polyol obtained by the present invention is preferably 1,250 to 12,000, more preferably 1,500 to 8,000, most preferably 2,500 to. 6,500.
The viscosity of the polymer polyol is measured by a method described in JIS K1557-5: 2007 at 25 ° C. using a Brookfield viscometer.

The aldehyde content in the polymer polyol is 600 ppm or less based on the weight of the polymer polyol, and is preferably 400 ppm or less, more preferably 200 ppm or less, particularly preferably 100 ppm or less, and most preferably 50 ppm or less from the viewpoint of VOC. is there.
Here, the aldehyde refers to formaldehyde, acetaldehyde, and propionaldehyde.

The total content of formaldehyde and acetaldehyde is 10 ppm or less based on the weight of the polymer polyol, preferably 8 ppm or less, more preferably 6 ppm or less, and particularly preferably 4 ppm or less from the viewpoint of VOC.
The aldehyde content can be measured by liquid chromatography “LC-6A” (manufactured by Shimadzu Corporation), and after preparing a calibration curve of the concentration and area of each aldehyde in advance, the sample can be measured and determined.

As the step (I), a batch polymerization method and a continuous polymerization method are preferable, and a multistage continuous polymerization method described below is more preferable.
The batch polymerization method and the continuous polymerization method are known for producing polymer polyols (Japanese Patent Laid-Open No. 2005-162791, Japanese Patent Laid-Open No. 8-333508, Japanese Patent Laid-Open No. 2004-002800 (corresponding US Patent Application: US2005)). / 245724 A1)} method can be used.

  The multistage continuous polymerization method is a continuous polymerization method in which a mixed liquid (M1) containing a polyol (PL), an ethylenically unsaturated compound (E), a radical polymerization initiator (K), and a dispersant (D) is used. First step of polymerizing to obtain a polymer polyol, then polyol (PL), ethylenically unsaturated compound (E), radical polymerization initiator (K), dispersant (D) and polymer polyol obtained in the first step This is a method comprising a second step of polymerizing the mixed solution (M2) containing the polymer by a continuous polymerization method.

  In the multistage continuous polymerization method, the continuous polymerization method is a method in which a monomer-containing mixed solution is continuously supplied to a reaction vessel to continuously obtain a polymer polyol, and the polymerization may be performed by a semi-batch polymerization method. Alternatively, it may be performed in continuous flow piping.

  The gas phase oxygen concentration (volume ppm) in the step (I) is 10 to 300, and preferably 10 to 250, more preferably 10 to 200, and particularly preferably 10 to 150, from the viewpoint of productivity and aldehyde content. It is. The gas phase oxygen concentration can be measured by using a “trace oxygen analyzer System 900 Series” (manufactured by Nagano Electric Industry Co., Ltd.).

In the present invention, the proportion of the polymerization time in the above gas phase oxygen concentration range is preferably 50 to 100%, more preferably 80 to 100%, and then further from the viewpoint of aldehyde content. Preferably it is 90 to 100%, and most preferably 100%.
In the present invention, from the viewpoint of aldehyde content, it is preferred that the gas phase oxygen concentration range be within the above range until the polymerization rate of (E) exceeds 70%, more preferably 80%, particularly preferably more than 90%. is there.

  The polymerization temperature is preferably 100 to 200 ° C., more preferably 110 to 180 ° C., and particularly preferably 120 to 160 ° C. from the viewpoint of productivity and prevention of polyol decomposition.

  Step (II) is a step of distilling off the residual ethylenically unsaturated compound and / or diluting solvent (c) under reduced pressure, and they may be distilled off under reduced pressure while continuously adding water. .

  The pressure in the step (II) is preferably from 0.1 to 10 kPa, more preferably from 0.1 to 5 kPa, particularly preferably from 0.1 to 2 kPa, from the viewpoint of the residual ethylenically unsaturated compound and the aldehyde content.

  The temperature in the step (II) is preferably 40 to 200 ° C., more preferably 60 to 180 ° C., particularly preferably 80 to 170 ° C., from the viewpoint of the content of the residual ethylenically unsaturated compound and the prevention of polyol decomposition. .

  The polymer polyol (A) obtained by the production method of the present invention is used as at least a part of a polyol component used when producing a flexible polyurethane foam. That is, the polymer polyol (A) is used as at least a part of the polyol component, and the polyisocyanate component is reacted in the presence of at least one additive selected from a catalyst, a foaming agent and a foam stabilizer, to form a flexible polyurethane foam. Used to obtain In the polyol component, in addition to (A), other polyols such as the polyol (PL) may be contained as necessary.

  The use amount (% by weight) of (A) in the polyol component is 10 to 100, and preferably 15 to 90, more preferably 20 to 80, from the viewpoint of the physical properties of the resulting flexible polyurethane foam and the viscosity of the polyol component. Especially preferably, it is 25-70.

  As the polyisocyanate component, all organic polyisocyanates used in polyurethane foams can be used. Aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, modified products thereof (urethane groups) Carbodiimide group, allophanate group, urea group, burette group, isocyanurate group and oxazolidone group-containing modified product) and mixtures of two or more thereof.

  Aromatic polyisocyanates include aromatic diisocyanates having 6 to 16 C (excluding carbon in the NCO group; the following polyisocyanates are the same), aromatic triisocyanates having 6 to 20 C, and crude products of these isocyanates. Can be mentioned. Specific examples include 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4′- and 4,4′-diphenylmethane diisocyanate ( MDI), polymethylene polyphenylene polyisocyanate (crude MDI), naphthylene-1,5-diisocyanate, and triphenylmethane-4,4 ′, 4 ″ -triisocyanate.

  Examples of the aliphatic polyisocyanate include C6-10 aliphatic diisocyanate. Specific examples include 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and the like.

  Examples of the alicyclic polyisocyanate include C6-16 alicyclic diisocyanate. Specific examples include isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, and norbornane diisocyanate.

Examples of the araliphatic isocyanate include C8-12 araliphatic diisocyanate. Specific examples include xylylene diisocyanate and α, α, α ′, α′-tetramethylxylylene diisocyanate.
Specific examples of the modified polyisocyanate include carbodiimide-modified MDI.

  Among these, aromatic polyisocyanates are preferable from the viewpoint of physical properties of the reactive and flexible polyurethane foams, more preferably TDI, crude TDI, MDI, crude MDI and modified products of these isocyanates, particularly preferably TDI. , MDI and crude MDI.

  As the catalyst, any catalyst that accelerates the urethanization reaction can be used. Tertiary amine {triethylenediamine, N-ethylmorpholine, diethylethanolamine, tetramethylethylenediamine, diaminobicyclooctane, 1,2-dimethylimidazole, 1 -Methylimidazole, 1,8-diazabicyclo- [5,4,0] -undecene-7, bis (N, N-dimethylamino-2-ethyl) ether and N, N, N ', N'-tetramethylhexa Methylenediamine and the like} and / or metal carboxylates (potassium acetate, potassium octylate, stannous octylate, dibutylstannic dilaurate, lead octylate, etc.). From the viewpoint of physical properties of the flexible polyurethane foam, the amount of the catalyst used is preferably 0.01 to 5.0 parts by weight, more preferably 0.1 to 0.1 parts by weight with respect to 100 parts by weight of the polyol component used during the production of the flexible polyurethane foam. 2.0 parts by weight.

  Examples of the foaming agent include water, liquefied carbon dioxide, and low boiling point compounds having a boiling point of −5 to 70 ° C.

  Low boiling point compounds include hydrogen atom-containing halogenated hydrocarbons and low boiling point hydrocarbons. Specific examples of the hydrogen atom-containing halogenated hydrocarbon and low boiling point hydrocarbon include methylene chloride, HCFC (hydrochlorofluorocarbon) (HCFC-123, HCFC-141b, HCFC-142b, etc.); HFC (hydrofluorocarbon) (HFC- 152a, HFC-356mff, HFC-236ea, HFC-245ca, HFC-245fa and HFC-365mfc), butane, pentane and cyclopentane.

  Among these, from the viewpoint of moldability, water, liquefied carbon dioxide, methylene chloride, cyclopentane, HCFC-141b, HFC-134a, HFC-356mff, HFC-236ea, HFC-245ca, HFC-245fa, HFC-365mfc and It is preferable to use a mixture of two or more of these as a foaming agent.

Among the foaming agents, the amount of water used is 1.0 to 8.0 weights with respect to 100 parts by weight of the polyol component used in the production of the flexible polyurethane foam from the viewpoint of foam density at the time of foam formation and suppression of scorch generation. Part is preferable, and more preferably 1.5 to 7.0 parts by weight. The amount of the low boiling point compound used is preferably 30 parts by weight or less, more preferably 5 to 25 parts by weight, with respect to 100 parts by weight of the polyol component, from the viewpoint of poor molding. The amount of liquefied carbon dioxide is preferably 30 parts or less, and more preferably 1 to 25 parts.
In addition, in the above and the following, a part means a weight part.

  As the foam stabilizer, any of those used for the production of polyurethane foams can be used. Dimethylsiloxane foam stabilizers (such as “SRX-253” and “PRX-607” manufactured by Toray Dow Corning Co., Ltd.) and poly Ether-modified dimethylsiloxane foam stabilizer ["L-540", "SZ-1142", "L-3601", "SRX-294A", "SH-193", "SZ" manufactured by Toray Dow Corning Co., Ltd. -1720 "," SZ-1675t "," SF-2936F ", and" B-4900 "manufactured by Degussa Japan Co., Ltd.]. The amount of the foam stabilizer used is preferably from 0.5 to 5.0 parts by weight, more preferably from 100 parts by weight of the polyol component, from the viewpoints of physical properties of the flexible polyurethane foam, changes in physical properties over time, and foam discoloration. 1.0 to 3.0 parts by weight.

In the method for producing the polyurethane foam of the present invention, if necessary, other auxiliary agents described below may be used and reacted in the presence thereof.
Other auxiliaries include colorants (dyes and pigments), plasticizers (phthalates and adipates, etc.), organic fillers (synthetic short fibers, hollow microspheres made of thermoplastic or thermosetting resins, etc.) And known auxiliary components such as flame retardants (such as phosphate esters and halogenated phosphate esters), anti-aging agents (such as triazole and benzophenone), and antioxidants (such as hindered phenol and hindered amine).

  As the addition amount of these auxiliaries, the colorant is preferably 1 part by weight or less with respect to 100 parts by weight of the polyol component. The plasticizer is preferably 10 parts by weight or less, more preferably 5 parts by weight or less. The organic filler is preferably 50 parts by weight or less, more preferably 30 parts by weight or less. The flame retardant is preferably 30 parts by weight or less, and more preferably 2 to 20 parts by weight. The anti-aging agent is preferably 1 part by weight or less, more preferably 0.01 to 0.5 part by weight. The antioxidant is preferably 1 part by weight or less, more preferably 0.01 to 0.5 part by weight. The total amount of auxiliary agent used is preferably 50 parts by weight or less, more preferably 0.2 to 30 parts by weight.

  In the production of the flexible polyurethane foam of the present invention, the isocyanate index (index) [(NCO group / active hydrogen atom-containing group) equivalent ratio × 100] is 70 to 70 from the viewpoint of moldability and physical properties of the flexible polyurethane foam. 150 is preferable, more preferably 80 to 130, and particularly preferably 90 to 120.

  An example of a specific example of the method for producing the flexible polyurethane foam of the present invention is as follows. First, a predetermined amount of a polyol component for producing a flexible polyurethane foam, a foaming agent, a catalyst, a foam stabilizer, and, if necessary, other additives are mixed. The mixture and the organic polyisocyanate component are then rapidly mixed using a flexible polyurethane foam foamer or stirrer. The obtained mixed liquid (foaming stock solution) can be continuously foamed to obtain a flexible polyurethane foam. Alternatively, it can be poured into a sealed or open mold (made of metal or resin), subjected to a urethanization reaction, cured for a predetermined time, and then demolded to obtain a flexible polyurethane foam.

  The flexible polyurethane foam obtained by the method of the present invention is suitably used for vehicles, furniture, bedding, apparel, electrical equipment, electronic equipment or packaging.

  The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. In the following, “%”, “part” and “ratio” represent “% by weight”, “part by weight” and “weight ratio”, respectively, unless otherwise specified.

The composition and symbols of the raw materials used in Examples and Comparative Examples are as follows.
(1) Polyol Polyol (PL1-1): A polyol having a hydroxyl value of 34 and a terminal EO content of 14% obtained by adding propylene oxide (PO) to glycerol and then adding ethylene oxide (EO).
Polyol (PL1-2): A polyol having a hydroxyl value of 32 and a terminal EO content of 12% obtained by adding PO to pentaerythritol and then adding EO.
Polyol (PL1-3): Polyol obtained by random addition of PO-EO to glycerin, hydroxyl value = 56, EO content = 5%.

(2) Dispersant Dispersant (D-1): hydroxyl group obtained by jointing 1 mol of polyol (PL1-2) and 0.2 mol of 2-hydroxymethacrylate with 0.4 mol of TDI (tolylene diisocyanate) Dispersant with a value of 26 Dispersant (D-2): Dispersion of a hydroxyl value of 45 obtained by adding 1 mol of polyol (PL1-3) with 2 mol of dichloromethane and then adding 0.35 mol of glycidyl methacrylate Agent (3) Radical Polymerization Initiator Radical Polymerization Initiator (K-1): 1,1′-Azobis (2-methylbutyronitrile) [trade name “V-59”, manufactured by Wako Pure Chemical Industries, Ltd.]
(4) Catalyst Catalyst A: “TEDA-L33” manufactured by Tosoh Corporation (triethylenediamine / dipropylene glycol = 33/67 (weight ratio) solution)
Catalyst B: “TOYOCAT ET” manufactured by Tosoh Corporation (70% dipropylene glycol solution of bis (dimethylaminoethyl) ether)
Catalyst C: “Neostan U-28” (Stanas Octoate) manufactured by Nitto Kasei Co., Ltd.
(5) Foam stabilizer Foam stabilizer A: “TEGOSTAB B8737” manufactured by EVONIK
Foam stabilizer B: “SRX-280A” manufactured by Toray Dow Corning Co., Ltd.
(6) Isocyanate Isocyanate A: “CE-729” manufactured by Nippon Polyurethane Industry Co., Ltd. (TDI-80 (2,4- and 2,6-TDI, ratio of 2,4-isomer is 80%) / crude MDI (Average number of functional groups: 2.9) = 80/20 (weight ratio))
Isocyanate B: “Coronate T-80” (tolylene diisocyanate) manufactured by Nippon Polyurethane Industry Co., Ltd.

The measurement and evaluation methods in the examples are as follows.
<Aldehyde content>
A calibration curve of the concentration-area of each aldehyde is prepared in advance, and after measuring the area by liquid chromatography, the aldehyde concentration is determined using the calibration curve.
Measuring instrument: LC-6A (manufactured by Shimadzu Corporation)
Column: STRODS-II column
(2.6mmφ × 150mm)
Eluent: acetonitrile / water = 45/55 (vol%)
Flow rate: 0.8 ml / min
Detector: SPD-10AVvp (manufactured by Shimadzu Corporation)
Detection wavelength: 360 nm
Injection volume: 20 μl

<Polymer particle content>
In a 50 ml centrifuge tube for centrifugation, about 5 g of polymer polyol was precisely weighed to obtain the polymer polyol weight (W1). Dilution was carried out by adding 50 g of methanol. Using a cooling centrifuge [model number: H-9R, manufactured by Kokusan Co., Ltd.], it was centrifuged at 18,000 rpm for 60 minutes at 20 ° C. The supernatant was removed using a glass pipette. The operation of adding 50 g of methanol to the residual sediment, diluting, and centrifuging in the same manner as above to remove the supernatant was repeated three more times. The residual sediment in the centrifuge tube was dried under reduced pressure at 2,666-3,999 Pa (20-30 torr) at 60 ° C. for 60 minutes, the dried sediment was weighed, and the weight was defined as (W2). The value calculated by the following formula was used as the polymer particle content (% by weight).
Polymer particle content (% by weight) = (W2) × 100 / (W1)

Example 1 [Production of polymer polyol (A-1)]
In a four-necked flask equipped with a temperature controller, a vacuum stirring blade, a dropping pump, a pressure reducing device, a Dimroth condenser, a nitrogen inlet and an outlet, 300 parts of a polyol (PL1-1) and a dispersant (D-1) 30. 0 parts and 60 parts of xylene were added, and nitrogen gas was passed at a rate of 1 L / min for 1 hour, and then the gas phase oxygen concentration was measured. Further, the temperature was raised to 130 ° C. while aeration of nitrogen at a rate of 0.1 L / min. Next, a mixed solution of 128 parts polyol (PL1-1), 245 parts ACN, 105 parts St, 12.8 parts dispersant (D-1), 10 parts xylene and 3.0 parts radical polymerization initiator (K-1) ( Z-1) was continuously dropped using a dropping pump at a rate of 25 parts / minute, and after completion of dropping, the mixture was further polymerized at 130 ° C. for 30 minutes. Thereafter, the ventilation of the air-nitrogen mixed gas was stopped, and unreacted monomers and xylene were distilled off under reduced pressure at 130 ° C. to obtain a polymer polyol (A-1).

Example 2 [Production of polymer polyol (A-2)]
Instead of nitrogen, an air-nitrogen mixed gas having an oxygen concentration of 50 ppm by volume was used, and the gas phase oxygen concentration before raising the temperature to 130 ° C was 60 ppm by volume in the same manner as in Example 1 above. A polymer polyol (A-2) was obtained.

Example 3 [Production of polymer polyol (A-3)]
Instead of nitrogen, an air-nitrogen mixed gas having an oxygen concentration of 150 volume ppm was used, and the gas phase oxygen concentration before raising the temperature to 130 ° C was 170 volume ppm. A polymer polyol (A-3) was obtained.

Example 4 [Production of polymer polyol (A-4)]
Instead of nitrogen, an air-nitrogen mixed gas having an oxygen concentration of 200 volume ppm was used, and the gas phase oxygen concentration before raising the temperature to 130 ° C. was 220 volume ppm. A polymer polyol (A-4) was obtained.

Example 5 [Production of polymer polyol (A-5)]
Instead of nitrogen, an air-nitrogen mixed gas having an oxygen concentration of 250 volume ppm was used, and the gas phase oxygen concentration before raising the temperature to 130 ° C was 280 volume ppm. A polymer polyol (A-5) was obtained.

Example 6 [Production of polymer polyol (A-6)]
A polymer polyol (A-6) was obtained in the same manner as in Example 1 except that 105 parts of ACN and 245 parts of StN were used.

Example 7 [Production of polymer polyol (A-7)]
A polymer polyol (A-7) was obtained in the same manner as in Example 1 except that 245 parts of ACN, 100 parts of St, and 5 parts of divinylbenzene were used.

Example 8 [Production of polymer polyol (A-8)]
A polymer polyol (A-8) was obtained in the same manner as in Example 1, except that 230 parts of ACN, 100 parts of St, 10 parts of allyl alcohol PO 2.2 mol adduct, and 20 parts of methyl acrylate were used.

Example 9 [Production of polymer polyol (A-9)]
A polymer polyol (A) was prepared in the same manner as in Example 6 except that the polyol (PL1-3) was used instead of the polyol (PL1-1) and the dispersant (D-2) was used instead of the dispersant (D-1). -9) was obtained.

Comparative Example 1 [Production of polymer polyol (A-10)]
Instead of nitrogen, an air-nitrogen mixed gas having an oxygen concentration of 300 ppm by volume was used, and the gas phase oxygen concentration before raising the temperature to 130 ° C. was 330 ppm by volume in the same manner as in Example 1 above. A polymer polyol (A-10) was obtained.

Comparative Example 2 [Production of polymer polyol (A-11)]
Instead of nitrogen, an air-nitrogen mixed gas having an oxygen concentration of 500 volume ppm was used, and the gas phase oxygen concentration before raising the temperature to 130 ° C. was 530 volume ppm. A polymer polyol (A-11) was obtained.

  The volume average particle diameter, formaldehyde content, acetaldehyde content, propionaldehyde content and polymer particle content of the polymer polyols (A-1 to A-11) were measured and shown in Table 1.

  In Table 1, the polymer polyols of Examples 1 to 9 have a lower aldehyde content than Comparative Examples 1 and 2.

Examples 10-17, Comparative Example 3
In accordance with the foaming formulation shown in Table 2, after foaming a flexible polyurethane foam in a mold under the following foaming conditions, the foam is formed, then taken out of the mold and left for a day and night to measure the aldehyde content and various physical properties of the flexible polyurethane foam. did. The measured values of physical properties are also shown in Table 2, respectively.

(Foaming conditions)
Mold size: 40cm x 40cm x 10cm (height)
Mold temperature: 65 ° C
Mold material: Aluminum Mixing method: Polyol premix listed in Table 2 and isocyanate are mixed at 15 MPa using a high pressure urethane foaming machine (manufactured by Polymer Engineering).

(Measurement method of aldehyde content in foam)
Cut urethane foam into 10cm x 8cm x 7cm thick rectangular parallelepiped test pieces, put them in a tedra bag, exhaust the entire amount of air in the tedra bag, and enclose with dry air or nitrogen gas (2L), 80 ° C, After heating in an oven for 2 hours, the total amount of air or nitrogen gas in the tedra bag is collected in a DNPH cartridge (product name “Pak mini aero” manufactured by GL Sciences Inc.), and the solution eluted with 4 mL of acetonitrile contains the above aldehyde. It measured by the quantity measuring method. The measured value is described as ppm.

-The measurement method and unit of foam physical properties are shown below.
Density: Conforms to JIS K6400, unit is kg / m ³
Hardness (25% ILD): Conforms to JIS K6400, unit is N / 314 cm ²
Tensile strength: Conforms to JIS K6400, unit is kgf / cm ²
Tear strength: Conforms to JIS K6400, unit is kgf / cm
Cutting elongation: Conforms to JIS K6400, unit is%
Compression residual strain ratio: Conforms to JIS K6400, unit is%
Humid heat compression residual strain rate: Conforms to JIS K6400, unit is%

  In Table 2, the flexible polyurethane foams of Examples 10 to 17 have a lower aldehyde content than the flexible polyurethane foam of Comparative Example 3, and improved foam physical properties, particularly cutting elongation and compression residual strain.

Examples 18 and 19, Comparative Example 4
In accordance with the foaming formulation shown in Table 3, the polyurethane slab foam was foamed under the following foaming conditions, and after standing overnight, the aldehyde content and various physical properties of the polyurethane slab foam were measured. The measured values of physical properties are also shown in Table 3, respectively.

(Foaming conditions)
BOX SIZE: 30cm x 30cm x 30cm Empty box Material: Wood Mixing method: Hand mixing

(Measurement method of aldehyde content in foam)
Cut urethane foam into 10cm vertical x 8cm wide x 7cm thick rectangular test pieces, put them in a tedra bag, discharge all air in the bag, and then enclose with dry air or nitrogen gas (2L), 80 ° C, After heating in an oven for 2 hours, the total amount of air in the bag is collected in a DNPH cartridge (product name “Pak mini aero” manufactured by GL Sciences Inc.) and the solution eluted with 4 mL of acetonitrile is used to measure the aldehyde content. Measured with The measured value is described as ppm.

-The measurement method and unit of foam physical properties are shown below.
Density: Conforms to JIS K6400, unit is kg / m ³
Hardness (25% ILD): Conforms to JIS K6400, unit is N / 314 cm ²
Tensile strength: Conforms to JIS K6400, unit is kgf / cm ²
Tear strength: Conforms to JIS K6400, unit is kgf / cm
Cutting elongation: Conforms to JIS K6400, unit is%
Compression residual strain ratio: Conforms to JIS K6400, unit is%

  In Table 3, the polyurethane slab foams of Examples 18 and 19 have a lower aldehyde content than the polyurethane slab foam of Comparative Example 4, and the foam physical properties, particularly cutting elongation and compression residual strain, are improved.

  According to the production method of the present invention, a polymer polyol having a low aldehyde content can be produced, and a polyurethane foam having a low aldehyde content can be obtained by using this polymer polyol. In addition, the polyurethane foam obtained by using the polymer polyol of the present invention is excellent in physical properties (particularly, cutting elongation and compression residual strain). The molded product obtained by using the flexible urethane foam of the present invention is used for a wide variety of applications, particularly for vehicles, furniture, bedding, apparel, electrical equipment, electronic equipment, broadcasting, etc. Is preferably used.

Claims (6)

  Step (I) of polymerizing ethylenically unsaturated compound (E) in the presence of radical polymerization initiator (K) and dispersant (D) in polyol (PL) and unreacted ethylenically unsaturated compound A method for producing a polymer polyol comprising a step (II) of distilling, wherein the gas phase oxygen concentration in step (I) is 10 to 300 ppm, and the aldehyde content in the resulting polymer polyol is based on the weight of the polymer polyol The manufacturing method of the polymer polyol which is 600 ppm or less as.   The production method according to claim 1, wherein the total content of formaldehyde and acetaldehyde in the obtained polymer polyol is 10 ppm or less based on the weight of the polymer polyol.   The production method according to claim 1 or 2, wherein the total content of acrylonitrile and styrene in the ethylenically unsaturated compound (E) is 50 to 100% by weight based on the weight of (E).   A process for producing a polyurethane foam by reacting a polyol component and an isocyanate component in the presence of at least one additive selected from a catalyst, a foaming agent and a foam stabilizer, wherein the polyol component is claimed in claims 1 to 3. The manufacturing method of the flexible polyurethane foam which contains 10-100 mass% of polymer polyols obtained by the manufacturing method in any one of these on the basis of the weight of a polyol component.   The flexible polyurethane foam obtained by the manufacturing method of Claim 4.   A flexible polyurethane foam molded article for vehicles, furniture, bedding, apparel, electrical equipment, electronic equipment or packaging, comprising the flexible polyurethane foam according to claim 5.