JP2011057893A - Method for producing open-cell polyurethane foam and polyol composition used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form an open-cell polyurethane foam having a good dripping preventing effect in spraying and excellent adhesiveness to an object to be sprayed. <P>SOLUTION: A polyol composition is provided which is reacted with a polyisocyanate component to form the objective open-cell polyurethane foam. The polyol composition contains water as a foaming agent and contains, as polyol compounds, a polyether polyol (A) having a hydroxyl value of 30-70 mgKOH/g, an oxyethylene group content of 50-90 wt.% and a ratio of primary hydroxyl groups to terminal hydroxyl groups of 20-50% and a polyether polyol (B) having a hydroxyl value of 300-800 mgKOH/g, wherein a content of the polyether polyol (A) is 30-70 pts.wt. based on 100 pts.wt. of the polyol compounds and a content of the polyether polyol (B) is 20-70 pts.wt. based on 100 pts.wt. of the polyol compounds. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing an open-cell polyurethane foam using water as a foaming agent, and a polyol composition used in the method.

  Rigid polyurethane foams are known to have excellent heat insulation properties, and are roughly classified into closed cells and open cells depending on the cell state. Among them, the open-celled rigid polyurethane foam does not have the heat insulation properties as excellent as the closed-celled rigid polyurethane foam, but has a low density and excellent dimensional stability. Therefore, the spread as a spray type foam heat insulating material for the purpose of energy saving of the heat insulating material of a house, especially a detached house is progressing.

  As this type of open-cell polyurethane foam, non-fluorocarbon urethane foam using water as a foaming agent has been demanded and various proposals have been made. For example, Patent Literature 1 below discloses a polyether polyol (a) having an average functional group number of 2.5 to 4 and a hydroxyl value of 200 to 300, and a polyether polyol (b) having an average functional group number of 4 to 6 and a hydroxyl value of 400 to 900. ) Is used in a weight ratio of (a) / (b) = 35/65 to 97/3.

  In Patent Document 2 below, a foam-breaking foam stabilizer is used as a foam stabilizer to be blended with the polyol composition, and as a polyol compound, a polyether polyol having a hydroxyl value of 400 to 600 mgKOH / g, 70 to 90 parts by weight, The use of 10-30 parts by weight of Mannich polyol is disclosed.

  Patent Document 3 below discloses a hydroxyl value of 28 to 90 mgKOH / g, a polyoxyethylene unit content of 5% by weight or less, and a terminal primary hydroxyl group content of 15% or less of a polyoxyalkylene polyol of 30 to 60% by weight, and a hydroxyl group. Polyoxyalkylene polyol having a value of 150 to 500 mg KOH / g, terminal primary hydroxyl group content of 5% or less, and 30 to 60% by weight of polyoxyalkylene polyol, and a polyol value of hydroxyl value of 450 to 840 mg KOH / g and terminal primary hydroxyl group content of 5% or less. It is disclosed to use a polyol compound consisting of ˜25% by weight.

  The following Patent Document 4 discloses a hydroxyl value of 5 to 25% by weight of a polyoxyalkylene polyol having a hydroxyl value of 20 to 120 mgKOH / g, an oxyethylene group content of 5% by weight or less, and a primary hydroxyl group ratio of 15% by mole or less. 300 to 850 mg KOH / g, the oxyethylene group content is 5 wt% or less, the proportion of primary hydroxyl groups is 15 mol% or less and the polyoxyalkylene polyol having a nitrogen atom is 40 to 80 wt%, and the hydroxyl value is 300 to 1830 mg KOH / It is disclosed to use a polyol compound consisting of 5 to 30% by weight of a polyol having no nitrogen atom and 3 to 12% by weight of a monol.

  In the following Patent Document 5, the polyoxyalkylene polyether polyol (A) having a number average molecular weight of 2000 to 9000 is 60 to 90% by weight and the polyoxyalkylene polyether polyol having a number average molecular weight of 250 to 750 (B It is disclosed that by using a polyol composition comprising 5 to 40% by weight, a rigid polyurethane foam that is lightweight and has open cells but a low restoration rate is obtained.

Japanese Patent Application Laid-Open No. 2004-091643 Japanese Patent Laid-Open No. 2008-174689 Japanese Patent Application Laid-Open No. 06-025376 Japanese Patent Laying-Open No. 2005-075860 JP 2002-293868 A Japanese Patent Laid-Open No. 09-110960

  In recent years, with the spread of energy saving in houses, the demand for sprayed open-cell polyurethane foam has increased and it has been used by many users, and the objects to be sprayed have been diversified due to diversification of building specifications, etc. . For example, as conventional spraying objects, there are many hard face materials such as plywood and other boards, but the number of cases where it is applied to soft face materials such as moisture permeable waterproof sheets such as Tyvek sheet is increasing. Therefore, improvement in adhesion to such a soft face material is required. Moreover, in order to improve the workability | operativity with respect to various spraying objects and to improve the surface smoothness of the obtained foam, it is also calculated | required to prevent the dripping at the time of spraying.

  In the case of open-cell polyurethane worms, a large amount of water vapor, amine gas, carbon dioxide gas due to the reaction between polyol and isocyanate groups escapes by opening cells in the foaming process during foam formation. It is thought that the gas that escapes in the direction affects the decrease in adhesion.

  As described above, various proposals have been made as open-cell polyurethane foams, but they are sufficiently satisfactory in terms of improving the smoothness of the foam surface by preventing dripping at the time of spraying and improving the adhesion to the object to be sprayed. Nothing has been obtained and further improvements are required.

  Patent Document 5 discloses that a high molecular weight polyoxyalkylene polyether polyol having a hydroxyl value of 30 to 60 mgKOH / g is used, and the ratio of ethylene oxide in the alkylene oxide is 5 to 70. The point that it is preferable to be weight% is described. However, this document does not disclose the ratio of terminal hydroxyl groups of the high molecular weight polyether polyol, nor does it disclose advantageous effects of the present invention described later.

  Patent Document 6 discloses a high molecular weight polyether polyol having a hydroxyl value of 34 to 56, the oxyethylene content in the polyoxyalkylene is 50 to 90% by weight, and the primary hydroxyl groups are all contained. It is disclosed that a polyol having a hydroxyl group of 30% or less is used for producing a rigid polyurethane foam. However, the polyurethane foam targeted by this document is of high density due to the small amount of water. Moreover, this document is only intended to obtain a high degree of communication using water as a foaming agent, and does not disclose the advantageous effects of the present invention described later.

  In view of the above points, the present invention provides a polyol composition capable of forming an open-cell polyurethane foam excellent in the smoothness improvement of the foam surface by preventing dripping at the time of spraying and the adhesion to the object to be sprayed, Another object of the present invention is to provide a method for producing an open-cell polyurethane foam using the polyol composition.

The polyol composition according to the present invention contains a polyol compound and a foaming agent, and reacts with a polyisocyanate component to form an open-cell polyurethane foam,
The polyol compound is a polyether having a hydroxyl value of 30 to 70 mg KOH / g, a content of oxyethylene groups in the polyoxyalkylene chain of 50 to 90% by weight, and a primary hydroxyl group content of 20 to 50%. A polyol (A) and a polyether polyol (B) having a hydroxyl value of 300 to 800 mgKOH / g, and the content of the polyether polyol (A) is 30 to 70 parts by weight in 100 parts by weight of the polyol compound. In addition, the content of the polyether polyol (B) is 20 to 70 parts by weight in 100 parts by weight of the polyol compound, the foaming agent is water, and 15 to 35 parts by weight of water with respect to 100 parts by weight of the polyol compound. It is characterized by containing a part.

A method for producing an open-cell polyurethane foam according to the present invention is a method for producing a polyurethane foam by mixing and reacting a polyol composition containing a polyol compound and a foaming agent and a polyisocyanate component,
The polyol compound is a polyether having a hydroxyl value of 30 to 70 mg KOH / g, a content of oxyethylene groups in the polyoxyalkylene chain of 50 to 90% by weight, and a primary hydroxyl group content of 20 to 50%. A polyol (A) and a polyether polyol (B) having a hydroxyl value of 300 to 800 mgKOH / g, and the content of the polyether polyol (A) is 30 to 70 parts by weight in 100 parts by weight of the polyol compound. In addition, the content of the polyether polyol (B) is 20 to 70 parts by weight in 100 parts by weight of the polyol compound, the foaming agent is water, and 15 to 35 parts by weight of water with respect to 100 parts by weight of the polyol compound. It is characterized by containing a part.

  According to the present invention, by using a polyol composition containing a polyol compound having the above-described configuration, in an open-cell polyurethane foam using water as a blowing agent, the reaction rate with the polyisocyanate component is increased, and the liquid during spraying is increased. By preventing anyone, the surface smoothness of the foam can be improved, and the adhesion to the object to be sprayed can be improved. Further, by using the polyether polyol (A) having a small hydroxyl value, it is possible to impart appropriate toughness to the obtained open-cell urethane foam, which improves the disadvantage of the brittleness of the conventional open-cell rigid polyurethane foam. be able to.

  The polyol composition according to the present invention has, as the polyol compound, a hydroxyl value of 30 to 70 mgKOH / g, an oxyethylene group content in the polyoxyalkylene chain of 50 to 90% by weight, and a terminal hydroxyl group primary ratio of 20 to 20%. A polyether polyol (A) that is 50% and a polyether polyol (B) having a hydroxyl value of 300 to 800 mgKOH / g are used.

  A polyol having a small hydroxyl value such as polyether polyol (A) is generally used for flexible polyurethane foam. Moreover, in the general-purpose polyol for flexible polyurethane foam, the alkylene oxide to be subjected to addition polymerization is mainly propylene oxide, whereas in the present invention, ethylene oxide is mainly used and the terminal hydroxyl group having a high primary hydroxylation rate is used. By using such a special polyether polyol (A), in the open-cell polyurethane foam using water as a foaming agent, the reaction rate with the polyisocyanate component can be increased, and an appropriate foam can be used for the obtained foam. Toughness can be imparted.

  The polyether polyol (A) is a polyoxyalkylene polyol obtained by ring-opening addition polymerization of an alkylene oxide such as ethylene oxide or propylene oxide to an initiator having two or more active hydrogen atoms. Initiators include aliphatic polyhydric alcohols (eg, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, neopentyl glycol, Glycols such as cyclohexylene glycol and cyclohexanedimethanol, triols such as trimethylolpropane and glycerin, tetrafunctional alcohols such as pentaerythritol, polyhydric alcohols such as sorbitol and sucrose), aliphatic amines (for example, ethylenediamine) Alkylene diamines such as propylene diamine, butylene diamine, hexamethylene diamine and neopentyl diamine, alkanol amines such as monoethanol amine and diethanol amine), Group amines (for example, 2,4-toluenediamine, 2,6-toluenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, p-phenylenediamine, o-phenylenediamine, naphthalenediamine, etc.) These may be used alone or in combination of two or more. As the initiator, an aliphatic alcohol is preferably used, and glycols and triols are particularly preferably used.

  The hydroxyl value of the polyether polyol (A) is 30 to 70 mgKOH / g, and more preferably 40 to 60 mgKOH / g. When the hydroxyl value is less than 30 mg KOH / g, the viscosity ratio of the polyol composition to the polyisocyanate component increases, leading to poor stirring during mixing. On the contrary, when it exceeds 70 mgKOH / g, it becomes difficult to give moderate toughness to the obtained polyurethane foam. The hydroxyl value is a value measured according to JIS K1557-1: 2007.

  The oxyethylene group content of the polyether polyol (A) is 50 to 90% by weight, more preferably 60 to 80% by weight. Moreover, the primary ratio of the terminal hydroxyl group is 20 to 50%, more preferably 25 to 40%. In this way, by using a polyol having a high oxyethylene group content and high activity, it is possible to increase the reaction rate and prevent dripping at the time of spraying, and to improve the adhesion to the sprayed object, It is also advantageous for communication. Furthermore, since the hydrophilicity is high, the wettability with respect to the plywood or the board can be improved, and the adhesiveness can also be improved from this point. Here, the oxyethylene group content (hereinafter referred to as EO content) is the content (% by weight) of the ethylene oxide-derived portion of the alkylene oxide reacted with the initiator. The primary hydroxylation rate of terminal hydroxyl groups is the ratio (%) of primary hydroxyl groups to all hydroxyl groups possessed by the polyol. The other alkylene oxide used together with ethylene oxide as the alkylene oxide to be subjected to addition polymerization is preferably propylene oxide.

  The polyether polyol (A) preferably has an average functional group number of 2 to 4, more preferably 2.5 to 3.5. Here, the average number of functional groups means the average number of active hydrogen atoms in the initiator used for the production of the polyol.

  The polyether polyol (B) is a polyoxyalkylene polyol obtained by subjecting an initiator having two or more active hydrogen atoms to ring-opening addition polymerization of alkylene oxide. A monohydric alcohol, an aliphatic amine, an aromatic amine, etc. are mentioned, It does not specifically limit. As an initiator, it is particularly preferable to use an amine-based initiator such as an aliphatic amine such as ethylenediamine or an aromatic amine.

  The hydroxyl value of the polyether polyol (B) is 300 to 800 mgKOH / g, more preferably 350 to 600 mgKOH / g, and still more preferably 400 to 500 mgKOH / g. When the hydroxyl value is less than 300 mgKOH / g, the reaction rate is lowered, and foam sinking (so-called back shot) occurs after degassing. Conversely, when it exceeds 800 mgKOH / g, degassing deteriorates and shrinkage of the foam occurs. Is likely to occur.

  The polyether polyol (B) preferably has an average functional group number of 2 to 8, more preferably 3 to 4.

  In the polyether polyol (B), the alkylene oxide addition-polymerized to the initiator is not particularly limited, but propylene oxide alone or a combination of propylene oxide and ethylene oxide is preferable. Moreover, although EO content rate is not specifically limited, It is preferable that it is 60 weight% or less, More preferably, it is 50 weight% or less.

  In the polyol compound, the content of the polyether polyol (A) is 30 to 70 parts by weight in 100 parts by weight of the polyol compound, and the content of the polyether polyol (B) is 20 to 70 parts by weight in 100 parts by weight of the polyol compound. Used as If the content of the polyether polyol (A) is less than 30 parts by weight, the effect of improving the reaction rate with the polyisocyanate component and imparting toughness will be insufficient. Conversely, if the content exceeds 70 parts by weight, the hardness as a rigid polyurethane foam will be reduced. It becomes difficult to secure. The content of the polyether polyol (A) is more preferably 40 to 60 parts by weight, still more preferably 40 to 55 parts by weight. Moreover, content of polyether polyol (B) becomes like this. More preferably, it is 30-60 weight part, More preferably, it is 35-60 weight part.

  As the above polyol compound, it is preferable to further blend a diol (C) having a hydroxyl value of more than 800 mgKOH / g and not more than 1900 mgKOH / g as the third polyol. Such a low molecular weight diol (C) is bifunctional and therefore has little effect as a cross-linking agent. However, the combination of the above-mentioned specific polyether polyols (A) and (B) makes the strength of the foam cell wall strong. The back shot can be improved and the isocyanate index can be adjusted. Moreover, the viscosity increase of the polyol composition by using high molecular weight polyether polyol (A) can be suppressed by addition of this diol (C).

  Examples of such diol (C) include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, and the like. The hydroxyl value of the diol (C) is preferably more than 800 mgKOH / g and not more than 1100 mgKOH / g. A particularly preferred diol (C) is dipropylene glycol.

  The content of the diol (C) is preferably 2 to 15 parts by weight, more preferably 5 to 10 parts by weight, in 100 parts by weight of the polyol compound.

  The polyol composition according to the present invention contains water as a foaming agent. The foaming agent is preferably water alone, and the blending amount thereof is 15 to 35 parts by weight, more preferably 18 to 30 parts by weight, still more preferably 20 to 27 parts by weight based on 100 parts by weight of the polyol compound. Part. Thus, the density of polyurethane foam can be reduced by blending a large amount of water.

  In general, the polyol composition according to the present invention further contains a flame retardant, a catalyst, and a foam stabilizer. Moreover, you may further mix | blend various additives mix | blended with the polyol composition for open cell rigid polyurethane foams, such as a coloring agent and antioxidant.

  Examples of the flame retardant include metal compounds such as organophosphates, halogen-containing compounds, and aluminum hydroxide. Particularly, organophosphates are preferable because they have an effect of reducing the viscosity of the polyol composition. Examples of the organic phosphate esters include halogenated alkyl esters of phosphoric acid, alkyl phosphate esters, aryl phosphate esters, and phosphonate esters. Specific examples include tris (chloropropyl) phosphate (TMCPP, manufactured by Daihachi Chemical), tributoxyethyl phosphate (TBEP, manufactured by Rhodia), tributyl phosphate, triethyl phosphate, trimethyl phosphate, cresyl phenyl phosphate, and the like. It is preferable that the compounding quantity of a flame retardant is 40 parts weight or less with respect to 100 weight part of polyol compounds, More preferably, it is 5-40 weight part.

  Although it will not specifically limit if it is a catalyst which accelerates | stimulates a urethanation reaction, Preferably it is using the reactive amine catalyst which can react with the isocyanate group of a polyisocyanate component. Examples of such reactive amine catalysts include N, N-dimethylethanolamine, N, N-dimethylaminoethoxyethanol, N, N, N′-trimethylaminoethylethanolamine, N, N, N ′, N ′. -Tetramethyl-2-hydroxypropylenediamine, N-hydroxyethylmorpholine, N-methyl-N-hydroxyethylpiperazine, N, N-dimethylpropylenediamine and the like, particularly preferably N, N-dimethylaminoethoxyethanol N, N-dimethylpropylenediamine is used, more preferably both are used in combination. By using these catalysts, the foamed cells can be made uniform and fine and can be easily communicated.

  In addition, a normal tertiary amine catalyst can also be used, and as such a tertiary amine catalyst, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′— Examples include tetramethylhexamethylenediamine, N, N, N ′, N ′, N ″ -pentamethyldiethylenetriamine, diazabicycloundecene, N, N-dimethylcyclohexylamine, triethylenediamine, and N-methylmorpholine.

  The compounding amount of the catalyst is preferably 2 to 10 parts by weight, more preferably 3 to 8 parts by weight with respect to 100 parts by weight of the polyol compound. When N, N-dimethylaminoethoxyethanol and N, N-dimethylpropylenediamine are used in combination as the catalyst, 1 to 5 parts by weight of N, N-dimethylaminoethoxyethanol and 1 to 5 of N, N-dimethylpropylenediamine are used. It is preferable to use parts by weight.

  As the foam stabilizer, among the foam stabilizers for known rigid polyurethane foams, a foam-breaking foam stabilizer (hereinafter referred to as a foam-breaking agent) and a foam stabilizer having a good foam-stabilization function are used in combination. It is preferable to do. The foam breaker is a foam stabilizer having a strong action (communication) that destroys the formed cells (bubbles) in the foaming reaction of the rigid polyurethane foam. For example, SILBK9210 (manufactured by Big Chemie) or BF2470 (Evonik Degussa Japan) Commercially available products such as those manufactured by KK are preferably used. On the other hand, as a foam stabilizer having good foam stability (hereinafter simply referred to as a foam stabilizer), for example, a graft copolymer of polyoxyalkylene glycol, which is a polymer of ethylene oxide or propylene oxide, and polydimethylsiloxane is used. A silicone foam stabilizer having a content of oxyethylene group in polyoxyalkylene of 70 to 100 mol% is preferably used. Specifically, SH-193, SF-2937 (manufactured by Toray Dow Corning Silicone) , B-8465 (Evonik Degussa Japan).

  The blending amount of the foam breaker is preferably 1 to 5 parts by weight with respect to 100 parts by weight of the polyol compound, and the blending amount of the foam stabilizer is 1 to 5 parts by weight with respect to 100 parts by weight of the polyol compound. It is preferable. Further, the ratio of the foam breaker to the foam stabilizer is preferably a foam breaker / foam stabilizer = 3/1 to 1/3, more preferably 3/1 to 3/2 by weight. . Thus, by using a foam breaker and a foam stabilizer in combination, an excellent cell form as an open-cell polyurethane foam can be obtained in combination with the configuration of the polyol compound and water foaming. The adhesive strength with the attachment object can be further improved.

  Various polyisocyanate compounds such as aromatic, alicyclic and aliphatic polyisocyanates having two or more isocyanate groups are used as the polyisocyanate component which is mixed and reacted with the polyol composition to form an open-cell polyurethane foam. be able to. Preferably, liquid diphenylmethane diisocyanate (MDI) is used because of ease of handling, speed of reaction, excellent physical properties of the resulting polyurethane foam, and low cost. As liquid MDI, crude MDI (c-MDI) (V-460, 44V-10, 44V-20, etc. (manufactured by Sumika Bayer Urethane Co., Ltd.), Millionate MR-200 (Nippon Polyurethane Industry)), uretonimine-containing MDI (Millionate) MTL; manufactured by Nippon Polyurethane Industry). In addition to liquid MDI, other polyisocyanate compounds may be used in combination. As the polyisocyanate compound to be used in combination, polyisocyanate compounds known in the technical field of polyurethane can be used without limitation.

  In the method for producing an open-cell polyurethane foam according to the present invention, the polyol composition and the polyisocyanate component are mixed and reacted. It is preferable that the isocyanate index at the time of making it react is 40-70, More preferably, it is 50-60. If the isocyanate index is too large, back shots and primary shrinkage tend to occur. On the other hand, if the isocyanate index is too small, the foam core tends to crack. Here, the isocyanate index is the percentage equivalent of the isocyanate group of the polyisocyanate component to all active hydrogen groups contained in the polyol composition (calculated using water as a blowing agent as a bifunctional active hydrogen compound). (Equivalent ratio of isocyanate groups to 100 equivalents of active hydrogen groups), also referred to as an NCO index.

The density of the open-celled polyurethane foam obtained by the production method, is preferably 20 kg / ^{m 3} or less, more preferably 5~15kg / ^{m 3,} even more preferably at 8~15kg / ^{m 3} . Such foam density can be set within the above range by adjusting the amount of water as a foaming agent, for example. Here, the foam density is a value measured according to JIS K7222.

  Moreover, it is preferable that the open-cell polyurethane foam obtained by this manufacturing method has a closed cell rate of 15% or less, More preferably, it is 0 to 10%. By increasing the communication rate in this way, it is possible to ensure excellent dimensional stability as an open-cell polyurethane foam. Here, the closed cell ratio has a value measured according to ASTM D2856.

  Since the open-cell polyurethane foam obtained by the production method has moderate toughness as described above and is restored without buckling when the foam is pushed in, it is not strictly a rigid polyurethane foam. In general, it can be used as a heat insulating material for a house in which a rigid urethane foam is used, so it belongs to an open-cell rigid polyurethane foam in a broad sense.

  When producing an open-cell polyurethane foam by the production method, for example, as a construction method for on-site construction, a spray method in which a construction base material of a building is sprayed and applied, a polyol composition in a void formed by the construction base material An injection method for injecting a mixture of a product and a polyisocyanate component, and the like are not particularly limited.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

(Preparation of polyol composition)
A polyol composition was prepared with the formulation described in Table 1 below. The details of each component in Table 1 are as follows.

-Polyol 1: "EP-505S" manufactured by Mitsui Chemicals Urethane Co., polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide by random polymerization using glycerol as an initiator (hydroxyl value = 52 mgKOH / g, containing EO) (Ratio = 70 to 75% by weight, primary hydroxyl group primary group conversion rate = 30%)
Polyol 2: Polyether polyol obtained by addition polymerization of propylene oxide using glycerol as an initiator (hydroxyl value = 34 mgKOH / g, EO content = 0% by weight, terminal hydroxyl group primary conversion = 0%)
Polyol 3: Polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide using sorbitol as an initiator (hydroxyl value = 35 mg KOH / g, EO content = 13% by weight, terminal hydroxyl group primary conversion rate = 65%)
Polyol 4: “EDP-450” manufactured by Asahi Denka Kogyo Co., Ltd., polyether polyol obtained by addition polymerization of propylene oxide using ethylenediamine as an initiator (hydroxyl value = 450 mgKOH / g, EO content = 0% by weight)
Polyol 5: “Excenol 450ED” manufactured by Asahi Glass Co., Ltd., polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide using ethylenediamine as an initiator (hydroxyl value = 450 mgKOH / g, EO content = 48% by weight, Terminal hydroxyl group primary ratio = 70%)
Polyol 6: “NF-13” manufactured by Mitsui Chemicals Urethane Co., Ltd. Blend of polyether polyol and amine polyether polyol with glycerol as an initiator (hydroxyl value = 500 mg KOH / g, EO content = 0% by weight)
Polyol 7: DPG, dipropylene glycol (hydroxyl value = 836 mg KOH / g)

・ Flame retardant: “TMCPP” manufactured by Daihachi Chemical Co., Ltd.
Catalyst 1: “Kao No. 26” (N, N-dimethylaminoethoxyethanol) manufactured by Kao Corporation
Catalyst 2: “U-CAT2000” (reactive amine catalyst) manufactured by San Apro
-Foam stabilizer: "B-8465" manufactured by Evonik Degussa Japan
-Foam breaker 1: "SILBK9210" manufactured by Big Chemie
-Foam breaker 2: "BF2470" manufactured by Evonik Degussa Japan

(Lab evaluation)
Each of the prepared polyol compositions was mixed with a polyisocyanate component and reacted according to a conventional method to produce an open-cell polyurethane foam. As the polyisocyanate component, c-MDI (“V-460” manufactured by Sumika Bayer Urethane Co., Ltd., NCO%: 30) was used, and the isocyanate index was as described in Table 1. The following evaluation was performed and the results are shown in Table 1.

[Formulation liquid properties]
Each prepared polyol composition was put into a glass screw tube and allowed to stand at 20 ° C. for 24 hours, and then the state of the liquid was observed. “Separation” in Table 1 indicates that the phases are separated into two phases.

[Internal voids, cracks]
Using a mold of 200 mm × 200 mm and depth of 200 mm, the resulting polyurethane foam was cut and examined for voids and cracks inside.

[Foaming (foaming speed)]
The reaction time of polyurethane worm was measured according to a conventional method. Specifically, the polyol composition and the polyisocyanate component are mixed and stirred by hand foaming. Time measurement was started at the stage of mixing, and the time until the reaction mixture became cloudy and rose up was shown as cream time, and the cream time was shown in the table as “foaming speed (seconds)”.

[Presence of back shot]
In the foamability test, the time from the mixing stage until the reaction mixture foamed and started up and reached the maximum height was defined as the rise time, and the decrease in the foam rise height after the rise time was measured with a scale. When the height reduction is 0 mm, “O” is given as no back shot, “△” is given when the height reduction is less than 5 mm, and “Back” is given when the height reduction is 5 mm or more. “×”.

[Form density]
A foam sample having a thickness of 100 mm × 100 mm and a thickness of 100 mm was cut out from the core layer excluding the skin layer from the polyurethane foam obtained by using a mold having a size of 200 mm × 200 mm and a depth of 200 mm. The density (kg / m ³ ) was calculated by measuring the weight in accordance with JIS K7222.

[Shrinkage]
Using a mold having a size of 200 mm × 200 mm and a depth of 200 mm, the foamed polyurethane worm was visually observed for dents on the side surface and bottom surface, and the case where the dent was 5 mm or more was evaluated as contracted.

  The results are as shown in Table 1. In Examples 1 to 7, the liquid properties of the polyol composition are uniform, and the resulting polyurethane foam has a low density and is free from voids and cracks. No shrinkage was observed after foaming. In addition, the foaming speed was high and the foamability (reactivity) was excellent.

  On the other hand, in Comparative Examples 1 and 2 in which no high molecular weight polyether polyol was used, the foaming rate was slow and the reactivity was poor. Further, in Comparative Examples 3 to 5 using a high molecular weight polyether polyol outside the specified range of the present invention, although the foaming speed was high, the liquid property of the polyol composition was separated into two phases. Also, shrinkage was observed after foaming.

In Comparative Example 6, the blending amount of polyol 1 was too small, the foaming rate was slow, and the resulting polyurethane foam had voids in the gas reservoir inside, and also contracted after foaming. In Comparative Example 7, the amount of polyol 1 was too large, and shrinkage was observed after foaming.

(Evaluation of actual machine (spray))
About each open-cell polyurethane foam of the said Examples 1-7 and Comparative Examples 1 and 2, it spray-applied using the blowing foaming machine ("Powerful 1600" by the postcard machine service company). The evaluation method is as follows, and the results are shown in Table 2.

[Form density]
A polyurethane foam having a thickness of about 100 mm was constructed by spraying a polyurethane stock solution (mixed solution of a polyol composition and a polyisocyanate component) onto a vertical wall model with a moisture-permeable waterproof sheet attached as a face material. . From the obtained polyurethane foam, a foam sample having a size of 100 mm × 100 mm × thickness 50 mm was cut out from the core layer excluding the skin layer, and the foam sample was used for weight measurement in accordance with JIS K7222 to obtain a density (kg / m ³ ) Was calculated.

[Surface smoothness]
As a wall model with a moisture-permeable waterproof sheet attached as a face material, a polyurethane stock solution is sprayed on a vertical wall model (sidewall model) that assumes a side wall and a wall model (ceiling wall model) that assumes a ceiling. A polyurethane foam having a thickness of about 100 mm was constructed. The height difference of the unevenness on the surface of the obtained polyurethane foam (the difference in height between the peak of the peak and the bottom of the valley) was measured. The polyurethane foam produced for the side wall model has a surface height difference of 5 mm or less, and the polyurethane foam produced for the ceiling wall model has a surface height difference of 10 mm or less, and is judged to have excellent surface smoothness.

[Closed cell ratio]
Using the foam sample used for the evaluation of the foam density, the closed cell ratio was measured in accordance with ASTM D2856.

[Adhesive strength]
A polyurethane foam having a thickness of about 100 mm was constructed by spraying a polyurethane stock solution onto a vertical wall model in which a moisture-permeable waterproof sheet was adhered as a face material. Using the obtained polyurethane foam with a face material, two parallel cuts are made in the face material at an interval of 5 cm, the cut pieces are pulled at an angle of 150 degrees, and the peel load is obtained. The adhesive strength was measured.

[Toughness]
Using a push-pull scale ("Digital Force Gauge (MODEL DPS-50) manufactured by Imada Co., Ltd."), Attachment: Flat compression jig / 16.3mmφ (S-2)), the polyurethane foam buckles and the surface is destroyed. The load up to (compressive load) was measured. Also, those that buckled during compression under a load of 15 N or less are marked as “x” because they are inferior in toughness, those that do not buckle at 15 N or less and the shape that was pushed in by releasing the compression is restored, and excellent in toughness As “◯”.

[Thermal insulation properties]
Based on JIS A9526 (Blowing rigid urethane foam for thermal insulation of buildings), it conforms to JIS A1412-2 (Measurement method of thermal resistance and thermal conductivity of thermal insulation materials-Part 2: Heat flow meter method) (HFM method). The thermal conductivity was measured. In addition, it was determined whether or not it conforms to JIS A9526 Type A 3 (thermal conductivity is 0.040 W / m · K or less).

  The results are as shown in Table 2, and in Examples 1 to 7, the foam is water-single foamed, and has a low density and a high communication rate, and prevents dripping during spraying. The surface smoothness was good and the appearance was excellent. Moreover, the adhesiveness with respect to the spraying object was excellent, and also moderate toughness was provided. On the other hand, in Comparative Examples 1 and 2, dripping occurred at the time of spraying, the surface smoothness was inferior, and the adhesiveness to the object to be sprayed was also poor. Comparative Examples 1 and 2 were brittle foams without toughness.

  The present invention can be applied to the production of various open-cell polyurethane foams, and can be suitably used particularly for spray-type foam materials including residential heat insulating materials.

Claims (6)

A polyol composition containing a polyol compound and a foaming agent and reacting with a polyisocyanate component to form an open-cell polyurethane foam,
The polyol compound is a polyether having a hydroxyl value of 30 to 70 mg KOH / g, a content of oxyethylene groups in the polyoxyalkylene chain of 50 to 90% by weight, and a primary hydroxyl group content of 20 to 50%. A polyol (A) and a polyether polyol (B) having a hydroxyl value of 300 to 800 mgKOH / g, and the content of the polyether polyol (A) is 30 to 70 parts by weight in 100 parts by weight of the polyol compound. The content of the polyether polyol (B) is 20 to 70 parts by weight in 100 parts by weight of the polyol compound,
The said foaming agent is water and contains 15-35 weight part of water with respect to 100 weight part of said polyol compounds. The polyol composition for open-cell polyurethane foams characterized by the above-mentioned.   The polyol compound further contains a diol (C) having a hydroxyl value of more than 800 mgKOH / g and not more than 1900 mgKOH / g, and the content of the diol (C) is 2 to 15 parts by weight in 100 parts by weight of the polyol compound. The polyol composition for open-cell polyurethane foam according to claim 1. A method for producing an open-cell polyurethane foam comprising mixing a polyol composition containing a polyol compound and a foaming agent and a polyisocyanate component and reacting them to form a polyurethane foam,
The polyol compound is a polyether having a hydroxyl value of 30 to 70 mg KOH / g, a content of oxyethylene groups in the polyoxyalkylene chain of 50 to 90% by weight, and a primary hydroxyl group content of 20 to 50%. A polyol (A) and a polyether polyol (B) having a hydroxyl value of 300 to 800 mgKOH / g, and the content of the polyether polyol (A) is 30 to 70 parts by weight in 100 parts by weight of the polyol compound. The content of the polyether polyol (B) is 20 to 70 parts by weight in 100 parts by weight of the polyol compound,
The foaming agent is water and contains 15 to 35 parts by weight of water with respect to 100 parts by weight of the polyol compound.   The polyol compound further contains a diol (C) having a hydroxyl value of more than 800 mgKOH / g and not more than 1900 mgKOH / g, and the content of the diol (C) is 2 to 15 parts by weight in 100 parts by weight of the polyol compound. The method for producing an open-cell polyurethane foam according to claim 3.   5. The open-cell polyurethane foam according to claim 3, wherein an isocyanate index representing an equivalent ratio of isocyanate groups of the polyisocyanate component to active hydrogen groups contained in the polyol composition in terms of percentage is 40 to 70. Production method. The foam density of the obtained polyurethane foam is 20 kg / m ³ or less, and the closed cell ratio of the polyurethane foam is 15% or less. A method for producing polyurethane foam.