JP2011017027A - Process for producing rigid foam synthetic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a lightweight rigid foam excellent in an adhesiveness and a size stability, using water as a foaming agent.SOLUTION: Water is used as the foaming agent for the process for producing the rigid foam synthetic resin by a reaction and expansion of a polyol and a polyisocyanate by a spray method in the presence of an expansion adjusting agent, a catalyst and the foaming agent, wherein the water is used at 0.5-15 pts.mass based on 100 pts.mass of the polyol, with a proviso that the polyol (AA) is used as the polyether polyol obtained by a ring opening addition polymerization of a Mannich compound obtained by a reaction of phenols, aldehydes and alkanolamines, followed by addition of propylene oxide and ethylene oxide in this order, and the hydroxy group value is 100-400 mgKOH/g, and the ratio of ethylene oxide to the sum of propylene oxide and ethylene oxide is 55-80 mass%.

Description

  The present invention relates to a method for producing a rigid foam synthetic resin by a spray method. More specifically, the present invention relates to a method for producing a rigid foamed synthetic resin such as a rigid polyurethane foam, wherein the raw material system has a low viscosity and can produce a lightweight rigid foamed synthetic resin.

  A polyol and a polyisocyanate are reacted and foamed in the presence of a foam stabilizer, a catalyst and a foaming agent to produce a rigid foam synthetic resin (hereinafter referred to as a rigid foam) such as a rigid polyurethane foam and a rigid polyisocyanurate foam. Things are widely done. Here, as a polyol used in producing a rigid foam, a polyol obtained by subjecting a Mannich compound to ring-opening addition polymerization of an alkylene oxide (hereinafter, also referred to as Mannich polyol), the produced rigid foam has mechanical strength and From the viewpoint of excellent flame retardancy, it is suitably employed as a polyol for producing rigid foam. In particular, Mannich polyol is used relatively well as a raw material for rigid foams to be constructed as a heat insulating material in construction sites. Here, when manufacturing a rigid foam as a heat insulating material or the like at a construction site or the like, a spray method is often employed. Here, the spray method is a method in which a raw material is fed at a high pressure, a raw material liquid is sprayed from a spray gun onto a wall surface or the like to be constructed, and foamed on the wall surface or the like to form a heat insulating material or the like. The advantage of the spray method is that a heat insulating material having a desired thickness can be constructed regardless of the shape of the wall surface or the like that is the object of construction.

  When using Mannich polyol as a raw material when constructing rigid foams by this spray method, various studies have been conducted so that the viscosity of Mannich polyol can be kept low, and high-quality rigid foams can be obtained even by the spray method. (See Patent Documents 1 to 3).

JP-A-4-173826 JP-A-8-301820 Japanese translation of PCT publication No. 2002-524630

  On the other hand, in recent years, there has been a strong demand for weight reduction of rigid foams including heat insulating materials. In particular, it has been difficult to reduce the weight without sacrificing characteristics such as mechanical strength and flame retardancy obtained by using Mannich polyol. Furthermore, it has been difficult to achieve the above problems while reducing the number of compounds such as chlorinated fluorinations conventionally used as blowing agents. In particular, when a little more water is used for weight reduction, development of a method for obtaining a rigid foam having excellent adhesive properties, almost no shrinkage, and excellent foam properties such as mechanical strength has been desired.

  That is, the present invention solves the above problems, uses a little more water as a foaming agent, produces a rigid foam that is lightweight, excellent in adhesiveness, hardly shrinks, and has good mechanical properties, and a raw material. An object of the present invention is to provide a method for producing a rigid foam having excellent storage stability.

  That is, the present invention relates to a process for producing a rigid foamed synthetic resin by reacting and foaming a polyol and a polyisocyanate by a spray method in the presence of a foam stabilizer, a catalyst and a foaming agent. Use of water is 0.5 to 15 parts by mass with respect to 100 parts by mass of polyol, and the following polyol (AA) is used as at least a part of the polyol. To do. However, polyol (AA) is obtained by ring-opening addition polymerization of propylene oxide and ethylene oxide in this order to a Mannich compound obtained by reacting phenols, aldehydes, and alkanolamines. Is a polyether polyol in which the ratio of ethylene oxide to the total amount of propylene oxide and ethylene oxide is more than 55% by mass and 80% by mass or less.

Moreover, it is preferable that the ratio of the raw material at the time of obtaining the said Mannich compound is 1-1.8 mol of aldehydes, and 2-2.5 mol of alkanolamines with respect to 1 mol of phenols. Moreover, it is preferable that the hydroxyl value of the said polyol (AA) is 200-350 mgKOH / g. Moreover, it is preferable that the ratio of the ethylene oxide with respect to the total amount of the propylene oxide and ethylene oxide in the said polyol (AA) is 56-65 mass%. Moreover, it is preferable that the ratio of the said polyol (AA) is 10-100 mass% among polyols. Moreover, it is preferable that the viscosity at 25 degreeC of the said polyisocyanate is 50-150 mPa * s. Moreover, it is preferable to use a polyol in which polymer fine particles are stably dispersed as the polyol. Moreover, it is preferable that the density of the manufactured rigid foam synthetic resin is 15-30 kg / m < ³ >.

  According to the present invention, a relatively large amount of water is used as a foaming agent to produce a rigid foam that is lightweight, excellent in adhesiveness, compressive strength, dimensional stability, has almost no shrinkage, has a good appearance, and has good mechanical properties. Became possible. Moreover, it is excellent also in the storage stability of a raw material.

  In the method for producing a rigid foam of the present invention, a rigid foamed synthetic resin is produced by reacting and foaming a polyol and a polyisocyanate by a spray method in the presence of a foam stabilizer, a catalyst and a foaming agent. The details will be described below.

(Polyol (AA))
In the present invention, polyol (AA) is used as at least part of the polyol. Here, the polyol (AA) is obtained by ring-opening addition polymerization of propylene oxide and ethylene oxide in this order to a Mannich compound obtained by reacting phenols, aldehydes, and alkanolamines. Is a polyether polyol in which the ratio of ethylene oxide to the total amount of propylene oxide and ethylene oxide is more than 55% by mass and 80% by mass or less. That is, the polyol (AA) is Mannich polyol. The polyol (AA) is a polyether polyol obtained by subjecting the Mannich compound to ring-opening addition polymerization of alkylene oxide.

  The Mannich compound is obtained by reacting phenols, aldehydes, and alkanolamines. Here, examples of phenols include phenol, nonylphenol, cresol, bisphenol A, resorcinol and the like. Among these, nonylphenol is preferable in terms of improving the compatibility between the polyol and the isocyanate and improving the cell appearance. Examples of aldehydes include formaldehyde and paraformaldehyde, and formaldehyde is preferable in terms of improving the adhesiveness of the foam. Examples of the alkanolamines include monoethanolamine, diethanolamine, triethanolamine, 1-amino-2-propanol, aminoethylethanolamine and the like. Of these, diethanolamine is preferable in order to balance the improvement in foam strength and the reduction in the viscosity of the polyol.

  Moreover, it is preferable that the ratio of the raw material at the time of obtaining the said Mannich compound is 1-1.8 mol of aldehydes, and 2-2.5 mol of alkanolamines with respect to 1 mol of phenols. Here, if the aldehydes are in excess of the above range with respect to the phenols, an odor tends to be generated when producing a rigid foam, which is not preferable. Moreover, when there are less aldehydes than the said range with respect to phenols, there exists a problem that the viscosity of a polyol (AA) tends to become high and the adhesiveness of the rigid foam obtained tends to become low, and is unpreferable. Further, if the alkanolamines are in excess of the above range with respect to the aldehydes, the resulting rigid foam tends to shrink, which is not preferable. Moreover, when there are few alkanolamines with respect to aldehydes from the said range, the viscosity of a polyol (AA) will become high easily, and an odor tends to generate | occur | produce at the time of manufacturing a rigid foam, and is unpreferable. Among the ratios of the raw materials, the ratio of aldehydes to 1 mol of phenols is more preferably 1.2 to 1.7 mol, and further preferably 1.4 to 1.6 mol. Similarly, the ratio of alkanolamines to 1 mol of aldehydes is more preferably 1.15 to 2 mol, and further preferably 1.2 to 1.8 mol.

  Propylene oxide and ethylene oxide are used as the alkylene oxide used for the production of the polyol (AA). The order of alkylene oxide to be ring-opening addition polymerized to a Mannich compound is propylene oxide first, followed by ethylene oxide. Moreover, the ratio of ethylene oxide with respect to the total amount of propylene oxide and ethylene oxide exceeds 55 mass% and is 80 mass% or less. This range is more preferably 56 to 65% by mass. By making the order of the ring-opening addition polymerization in this order, most of the hydroxyl groups of the polyol (AA) become primary hydroxyl groups, the reactivity of the polyol (AA) is increased, and the reactivity with the isocyanate is increased, resulting in good appearance. This is preferable. Moreover, it is effective in improving the adhesiveness of the rigid foam obtained at the same time. On the other hand, if the ratio of ethylene oxide increases beyond the above ratio, the compression strength of the resulting rigid foam is lowered, and the resulting rigid foam tends to shrink, which is not preferable. Furthermore, when a low-boiling fluorine-containing compound is used as a foaming agent, the compatibility between the low-boiling fluorine-containing compound and the polyol tends to be low, the vapor pressure of the polyol mixture including the foaming agent tends to be high, and the raw material is stored. In particular, the pressure resistance of the container tends to be a problem in a high temperature environment in summer, which is not preferable. Moreover, when the ratio of ethylene oxide becomes smaller than the above ratio, the viscosity of the polyol (AA) tends to increase, and the adhesive property of the resulting rigid foam tends to decrease, which is not preferable. That is, by setting the above ratio, the compatibility between the polyol (AA) and the water used as the blowing agent is improved, the mixing property of the raw material containing isocyanate is improved, the appearance of the resulting rigid foam is improved, and the mechanical properties are improved. It is effective for improvement. Here, the proportion of primary hydroxyl groups of the polyol (AA) is preferably 60 to 100%.

  The hydroxyl value of the polyol (AA) is 100 to 400 mgKOH / g, preferably 200 to 350 mgKOH / g. When the hydroxyl value of the polyol (AA) is larger than 400 mgKOH / g, the amount of alkylene oxide-derived oxyalkylene chains present in the polyol (AA) is decreased. As a result, the viscosity of the polyol (AA) tends to be high, the rigid foam produced tends to be brittle, and the adhesiveness of the rigid foam tends to be insufficient. When the hydroxyl value of the polyol (AA) is less than 100 mgKOH / g, the resulting rigid foam tends to shrink, which is not preferable. That is, if it is in the said range, it is easy to ensure the mechanical strength of rigid foams, such as compressive strength, maintaining the mixing property of a raw material favorable, and preferable.

  10-100 mass% is preferable and, as for the ratio of a polyol (AA) among the polyols used for this invention, 20-60 mass% is more preferable. If it is this range, weight reduction can be achieved, providing the characteristics, such as mechanical strength and flame retardance, of the rigid foam obtained.

(Polyol (AB))
In the present invention, it is preferable to use a polyol (AB) described below in combination with the polyol (AA) described above as the polyol. That is, the polyol (AB) includes a polyether polyol produced by ring-opening addition polymerization of an alkylene oxide using an aromatic compound (excluding an aromatic amine compound) as an initiator, or an aromatic compound. A polyester polyol produced by polycondensation of monomers and having a hydroxyl value of 100 to 700 mgKOH / g. Among the polyols (AB), as a monomer used for producing a polyester polyol, a diol having an aromatic ring or a dicarboxylic acid having an aromatic ring is used. Examples of the diol having an aromatic ring include a diol obtained by adding ethylene oxide to bisphenol A. Examples of the dicarboxylic acid having an aromatic ring include phthalic acids such as terephthalic acid.

  Among the polyols (AB), as an initiator used for producing a polyether polyol, an aromatic compound excluding an aromatic amine compound is used, but bisphenol A is preferably used. The aromatic compound may be a condensed compound or a non-condensed compound. Condensation compounds include resol-type precondensates in which phenols are condensation-bonded with excess formaldehyde in the presence of an alkali catalyst, and benzylic precondensates reacted in a non-aqueous system when synthesizing this resol-type precondensate. And novolak-type precondensates obtained by reacting excess phenols with formaldehyde in the presence of an acid catalyst. The molecular weight of these initial condensates is preferably about 200 to 10,000. In the above, examples of phenols include phenol, nonylphenol, cresol, bisphenol A, resorcinol, and examples of aldehydes include formalin and paraformaldehyde. Examples of the non-condensed compound include polyphenols such as bisphenol A and resorcinol. Examples of the alkylene oxide used here include ethylene oxide and propylene oxide.

  The hydroxyl value of the polyol (AB) is 100 to 700 mgKOH / g, preferably 200 to 600 mgKOH / g. When the hydroxyl value of the polyol (AB) is within the above range, it is preferable because sufficient flame retardancy can be imparted while maintaining the mixing property of the polyol compound.

  10-80 mass% is preferable and, as for the ratio of a polyol (AB) among the polyols used for this invention, 20-70 mass% is more preferable. If the ratio of the polyol (AB) is within the above range, an appropriate flame retardancy can be imparted to the obtained rigid foam, and other mechanical properties and the like are not impaired.

(Polymer dispersed polyol (W))
In the present invention, it is preferable to use a polyol in which polymer fine particles are stably dispersed as the polyol. By using a polyol in which polymer fine particles are stably dispersed, shrinkage during the production of a rigid foam can be effectively suppressed. In particular, when producing a light-weight (specifically, core density of 15 to 30 kg / m ³ ) rigid foam, there is a remarkable effect in suppressing shrinkage. The polyol in which the polymer fine particles are stably dispersed may be produced by stably dispersing the polymer fine particles in the polyol, or may be produced by mixing the polyol in which the polymer fine particles are stably dispersed with the polyol (AA) or the like. Also good. However, the latter is particularly preferable because the polymer fine particles in the polyol have high stability and the production of the polyol according to the present invention is easy. A polyol in which polymer fine particles are stably dispersed is hereinafter referred to as a polymer-dispersed polyol. In the present invention, a polymer-dispersed polyol suitable for mixing with polyol (AA) or the like is hereinafter referred to as polymer-dispersed polyol (W).

  In the present invention, the polymer-dispersed polyol (W) is a polyether polyol (X) described later, an amine polyether polyol (Y) described later, and optionally other (polyether polyol (X), amine polyether polyol (Y). It is a polyol containing polyol (Z) other than). The mixing ratio of the polyether polyol (X), the amine-based polyether polyol (Y) and the other polyol (Z) in the polymer-dispersed polyol (W) is (X) / (Y) / (Z) by mass ratio. 5 to 97/3 to 35/0 to 92 is preferable, 10 to 60/5 to 35/10 to 85 is more preferable, and 25 to 50/8 to 25/25 to 67 is particularly preferable. The average hydroxyl value of the polymer-dispersed polyol (W) is preferably 200 to 800 mgKOH / g, more preferably 250 to 750 mgKOH / g. When the mixing ratio in the polymer-dispersed polyol (W) and the average hydroxyl value of the polymer-dispersed polyol (W) are in the above ranges, it is preferable that the polymer fine particles are easily dispersed stably.

(Polyether polyol (X))
The polyether polyol (X) is a polyether polyol having a hydroxyl value of 84 mgKOH / g or less and an oxyethylene group content of 40% by mass or more. The hydroxyl value of the polyether polyol (X) is 84 mgKOH / g or less, preferably 5 to 84 mgKOH / g, particularly preferably 30 to 60 mgKOH / g. Moreover, as an initiator used for manufacture of polyether polyol (X), a polyhydric alcohol more than trivalence is preferable. Specific examples thereof include glycerin, trimethylolpropane, and 1,2,6-hexanetriol. As the alkylene oxide used in the production of the polyether polyol (X), ethylene oxide alone or a combination of alkylene oxide having 3 or more carbon atoms such as propylene oxide and ethylene oxide is preferable. Here, the content of the oxyethylene group derived from ethylene oxide in the polyether polyol (X) is 40% by mass or more, preferably 50 to 90% by mass.

(Amine-based polyether polyol (Y))
The amine-based polyether polyol (Y) is a polyether polyol having a hydroxyl value of 250 to 900 mgKOH / g, obtained by ring-opening addition polymerization of alkylene oxide using an amine compound described later as an initiator. However, among the polyols (AA) described above, the hydroxyl value may fall within the above range. The hydroxyl value of the amine polyether polyol (Y) is 250 to 900 mgKOH / g, preferably 300 to 800 mgKOH / g, particularly preferably 350 to 800 mgKOH / g. Moreover, as an amine compound of the initiator used for manufacture of amine polyether polyol (Y), at least 1 sort (s) chosen from the group which consists of an aliphatic amine and an alicyclic amine is preferable. Examples of the aliphatic amine include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetraamine. Examples of the alicyclic amines include piperidines, piperazines, pyrrolidines, etc., piperazines are particularly preferred, and piperazines substituted with aminoalkyl groups are most preferred. Piperazine has a high effect as a catalyst for promoting the urethane bond forming reaction, and an effect of increasing the reactivity at the time of producing the rigid foam can be obtained. Examples of piperidines include 1- (2-aminoethyl) piperidine. Examples of piperazines include piperazine, N-aminomethylpiperazine, 1- (2-aminoethyl) piperazine and the like. Examples of pyrrolidines include 1- (2-aminoethyl) pyrrolidine. Moreover, as an alkylene oxide used for manufacture of amine polyether polyol (Y), ethylene oxide, propylene oxide, etc. are preferable.

(Polyol (Z))
Said other polyol (Z) is arbitrary polyols other than polyether polyol (X) and amine polyether polyol (Y). That is, the other polyol (Z) is one or more polyols selected from the group consisting of polyol (AA ′), polyol (AB), and polyol (V). However, the polyol (AA ′) is a polyether polyol other than the polyol (Y) in that the range of the hydroxyl value is deviated from the polyol (AA). The polyol (V) is a polyol other than the aforementioned polyol (AA), polyol (AB), polyether polyol (X), or amine-based polyether polyol (Y). Examples of the polyol (V) include polyether polyols, polyester polyols, polycarbonate polyols, polyhydric alcohols, and hydrocarbon polymers having a hydroxyl group at the terminal. The hydroxyl value of the other polyol (Z) is preferably 200 to 1000 mgKOH / g, particularly preferably 400 to 850 mgKOH / g.

(Polymer fine particles)
The polymer fine particles in the present invention are preferably polymer fine particles obtained by polymerizing a monomer having a polymerizable unsaturated bond. Specific examples of the monomer having a polymerizable unsaturated bond include nitrile monomers such as acrylonitrile, methacrylonitrile, 2,4-dicyano-1-butene; acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, Acrylic monomers such as acrylamide and methacrylamide; Styrene monomers such as styrene and α-methylstyrene; Vinyl ester monomers such as vinyl acetate and vinyl propionate; Isoprene, butadiene and other diene monomers; Maleic acid diesters Unsaturated fatty acid ester monomers such as itaconic acid diesters; vinyl halide monomers such as vinyl chloride; vinylidene halide monomers such as vinylidene chloride; methyl vinyl ether, ethyl vinyl ether, isopropyl Alkyl vinyl ether monomers such as vinyl ether and the like. Two or more of these monomers may be used in combination.

  As a combination of monomers having a polymerizable unsaturated bond, a combination of 5 to 90% by mass of a nitrile monomer and 10 to 95% by mass of another monomer is preferable. A combination of a nitrile monomer and a styrene monomer, or a combination of a nitrile monomer and a carboxylic acid vinyl ester monomer is preferable in order to obtain a polymer-dispersed polyol having a low viscosity and good dispersion stability. As the combination of the monomers, a combination of acrylonitrile and styrene and a combination of acrylonitrile and vinyl acetate are particularly preferable, and a combination of acrylonitrile and vinyl acetate is particularly preferable because of good dispersion stability.

  In the case of a combination of acrylonitrile and styrene, the ratio of acrylonitrile / styrene is preferably 90 to 40/10 to 60, and most preferably 85 to 60/15 to 40 in terms of mass ratio. In the case of a combination of acrylonitrile and vinyl acetate, the ratio of acrylonitrile / vinyl acetate is preferably 50 to 10/50 to 90, and most preferably 40 to 15/60 to 85 in terms of mass ratio.

  The amount of the monomer used is not particularly limited, but the concentration of the polymer fine particles in the polymer-dispersed polyol (W) is preferably about 1 to 50% by mass, particularly preferably 2 to 45% by mass, and most preferably 5 to 40% by mass. preferable.

(Method for producing polymer-dispersed polyol (W))
Examples of the method for producing the polymer-dispersed polyol (W) include the following two methods.

  The first method is a monomer having a polymerizable unsaturated bond in a mixture of polyether polyol (X), amine-based polyether polyol (Y) and other polyol (Z) in the presence of a solvent as necessary. In which particles are directly deposited. In the second method, a polyether polyol (X) is prepared by polymerizing a monomer having a polymerizable unsaturated bond in a solvent in the presence of a grafting agent that stabilizes the particles as necessary, and precipitating the particles. In this method, the solvent is replaced with a mixture of amine-based polyether polyol (Y) and other polyol (Z). In the present invention, either method can be adopted, and the first method is particularly preferable.

  For polymerization of a monomer having a polymerizable unsaturated bond, radical polymerization is usually employed. As polymerization initiators for radical polymerization, 2,2′-azobisisobutyronitrile (hereinafter referred to as AIBN), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2, 4-dimethylvaleronitrile), 2,2′-azobis (methyl 2-methylpropionate), benzoyl peroxide, diisopropyl peroxydicarbonate, acetyl peroxide, tert-butyl peroxide, persulfate and the like. In particular, AIBN, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), and 2,2′-azobis (methyl 2-methylpropionate) are preferable. .

  In order to improve the dispersion stability of the polymer fine particles, a grafting agent can be used. As the grafting agent, a compound having a polyether chain or a polyester chain and having a polymerizable unsaturated bond in the molecule can be used.

  As the grafting agent, an active hydrogen compound having an unsaturated bond in the molecule is used as an initiator, and a high molecular weight polyol or monool obtained by addition polymerization of alkylene oxide; a polyether polyol with maleic anhydride, After reacting with unsaturated carboxylic acid or unsaturated carboxylic acid anhydride such as itaconic anhydride, maleic acid, fumaric acid, acrylic acid, methacrylic acid, etc., high molecular weight obtained by adding alkylene oxide as required Polyol or monool; reaction product of alcohol having unsaturated bond such as 2-hydroxyethyl acrylate and butenediol with other polyol and polyisocyanate; epoxy having unsaturated bond such as allyl glycidyl ether in the molecule Examples include a reaction product of a compound and a polyol. These compounds preferably have a hydroxyl group but are not limited thereto.

(Polyol)
In the present invention, it is essential to use the above-described polyol (AA) as the polyol. The polyol in the present invention is preferably a polyol mixture having a hydroxyl value of 100 to 700 mgKOH / g and in which polymer fine particles are stably dispersed. Here, the hydroxyl value of the polyol mixture is preferably from 100 to 700 mgKOH / g, more preferably from 150 to 600 mgKOH / g. When the hydroxyl value is within this range, a rigid foam having good physical properties can be obtained. Moreover, as a density | concentration of a polymer fine particle, 0.05-4 mass% is preferable among a polyol mixture, and 0.2-1 mass% is more preferable. When the concentration of the polymer fine particles is in the above range, shrinkage of the obtained rigid foam can be effectively suppressed. That is, when the polymer dispersion polyol (W) having a polymer concentration of 25% by mass is mixed to obtain a polyol mixture, the ratio of the polymer dispersion polyol (W) is preferably 0.2 to 16% by mass, More preferably, it is 8-4 mass%.

  As the polyol in the present invention, in addition to the polyol (AA) and optionally the polymer-dispersed polyol (W), the aforementioned polyol (AB) may be mixed. In the present invention, it is preferable to use an amine polyether polyol (Y) in addition to the above-mentioned polyols. The amine polyether polyol (Y) to be further used in combination is preferably used depending on the foaming agent described later.

  That is, when water and a low-boiling fluorine-containing compound are used in combination as the foaming agent, it is preferable to use an amine-based polyether polyol (YC). However, the amine polyether polyol (YC) is an amine polyether obtained by ring-opening addition polymerization of propylene oxide alone or propylene oxide and ethylene oxide in this order using an aliphatic amine as an initiator. It is a polyol. Preferable examples include polyether polyols obtained by ring-opening addition polymerization of only propylene oxide using ethylenediamine as an initiator. Use of this amine-based polyether polyol (YC) is preferable because a lightweight rigid foam is easily obtained even in a low-temperature environment such as winter.

  Further, when only water is used as the foaming agent, it is preferable to use an amine-based polyether polyol (YD). However, amine polyether polyol (YD) is an amine polyether obtained by ring-opening addition polymerization of ethylene oxide alone or propylene oxide and ethylene oxide in this order using alicyclic amine as an initiator. It is a polyol. Preferable examples include polyether polyols obtained by ring-opening addition polymerization of only ethylene oxide using 1- (2-aminoethyl) piperazine as an initiator. Use of this amine-based polyether polyol (YD) is preferable because the miscibility of water and polyol is improved, and appearance defects are unlikely to occur.

  In the present invention, in addition to the above-mentioned polyols, other active hydrogen-containing compounds may be mixed and used in combination. Here, other active hydrogen-containing compounds include polyols, polyhydric phenols, and polyamines. The polyols that may be used in combination here are any polyols other than polyol (AA), polyol (AB), and polymer-dispersed polyol (W). Polyether polyol (X), amine-based polyether polyol (Y '), Consisting of one or more selected from the group consisting of polyol (V). However, the amine polyether polyol (Y ′) is an amine polyether polyol other than the polyol (AA) in the amine polyether polyol (Y).

  Specific examples of polyhydric phenols that may be used in combination include resol type initial condensate, benzylic type initial condensate, novolac type initial condensate, bisphenol A, resorcinol and the like. Examples of polyamines that may be used in combination include aromatic amines in addition to the aforementioned aliphatic amines and alicyclic amines. Examples of the aromatic amines include diaminotoluene, diethyldiaminotoluene, diaminodiphenylmethane, and the like.

(Foaming agent)
In the present invention, water is used as at least a part of the foaming agent. Moreover, a low boiling point fluorine-containing compound and an inert gas can be used together as a foaming agent. In the present invention, it is preferable to use only water as a foaming agent or to use water and a low-boiling fluorine-containing compound in combination. The amount of water used as the foaming agent is preferably 0.5 to 15 parts by mass, particularly preferably 0.5 to 8 parts by mass with respect to 100 parts by mass of the polyol. If the amount of water used is less than 0.5 parts by mass, the resulting rigid foam is not preferred because it is difficult to lighten. Moreover, when there is much usage-amount exceeding 15 mass parts, the miscibility of water and a polyol compound tends to deteriorate, and it is not preferable.

  Examples of the low boiling point fluorine-containing compound include 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1. , 1,3,3-pentafluorobutane (HFC-365mfc), 1,1,2,2-tetrafluoroethyl difluoromethyl ether (HFE-236pc), 1,1,2,2-tetrafluoroethyl methyl ether ( HFE-254pc), 1,1,1,2,2,3,3-heptafluoropropyl methyl ether (HFE-347mcc) and the like. Among these, as the low-boiling fluorine-containing compound, it is preferable to use one or more selected from the group consisting of HFC-134a, HFC-245fa, and HFC-365mfc. The amount of the low-boiling fluorine-containing compound used as the blowing agent is preferably 1 to 100 parts by weight, particularly preferably 5 to 60 parts by weight, based on 100 parts by weight of the polyol. Examples of the inert gas include air, nitrogen, carbon dioxide gas and the like.

  When the low-boiling fluorine-containing compound and water are used in combination, it is preferable in that it is easy to obtain a lightweight rigid foam, excellent in dimensional stability and mechanical properties of the obtained rigid foam, and excellent in thermal insulation properties of the rigid foam. . However, it is also preferable to use only water as the foaming agent in view of the fact that the use of the fluorine-containing compound gives a load to the environment.

(Polyisocyanate)
In the present invention, the polyisocyanate includes aromatic, alicyclic, and aliphatic polyisocyanates having two or more isocyanate groups; a mixture of two or more of the above polyisocyanates; An isocyanate etc. are mentioned. Specific examples include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl isocyanate (common name: crude MDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HMDI), and the like. These polyisocyanates or their prepolymer-modified products, nurate-modified products, urea-modified products, carbodiimide-modified products, and the like. Among these, crude MDI or a modified product thereof is preferable, and a modified product of crude MDI is particularly preferable.

  The viscosity of the polyisocyanate at 25 ° C. is preferably 50 to 150 mPa · s. If the viscosity is less than 50 mPa · s, the resulting rigid foam tends to shrink, which is not preferable. On the other hand, if the viscosity exceeds 150 mPa · s, the operability during spraying by the spray method is deteriorated, and the appearance of the resulting rigid foam is likely to be poor, which is not preferable.

  The amount of polyisocyanate used is represented by 100 times the number of isocyanate groups with respect to the total number of active hydrogens in the polyol and other active hydrogen compounds (usually, the number represented by 100 times is referred to as the isocyanate index), and 50 to 300 is preferable. Here, in a urethane formulation mainly using a urethanization catalyst as a catalyst, the amount of polyisocyanate compound used is an isocyanate index, preferably 50 to 140, more preferably 60 to 130. Moreover, in the isocyanurate prescription which mainly uses the catalyst which accelerates | stimulates the trimerization reaction of an isocyanate group as a catalyst, the usage-amount of a polyisocyanate compound is an isocyanate index, 120-300 are preferable and 150-250 are more preferable.

(catalyst)
The catalyst used in the present invention is not particularly limited as long as it is a catalyst that promotes the urethanization reaction. Examples thereof include tertiary amines such as triethylenediamine, bis (2-dimethylaminoethyl) ether, N, N, N ′, N′-tetramethylhexamethylenediamine; and organometallic compounds such as dibutyltin dilaurate. Moreover, you may use together the catalyst which accelerates | stimulates the trimerization reaction of an isocyanate group, and carboxylic acid metal salts, such as potassium acetate and potassium 2-ethylhexanoate, etc. are mentioned. When spray foaming is adopted as a method for producing a rigid foam, it is preferable to use an organometallic catalyst such as lead 2-ethylhexanoate in order to complete the reaction in a short time. As for the usage-amount of a catalyst, 0.1-10 mass parts is preferable with respect to 100 mass parts of polyol compounds.

(Foam stabilizer)
In the present invention, a foam stabilizer is used to form good bubbles. Examples of the foam stabilizer include silicone foam stabilizers and fluorine-containing compound foam stabilizers. Although the usage-amount of a foam stabilizer may be selected suitably, 0.1-10 mass parts is preferable with respect to 100 mass parts of polyol compounds.

(Other ingredients)
In the present invention, any compounding agent can be used in addition to the above-described polyol, polyisocyanate, foaming agent, catalyst, and foam stabilizer. Compounding agents include fillers such as calcium carbonate and barium sulfate; anti-aging agents such as antioxidants and UV absorbers; flame retardants, plasticizers, colorants, anti-fungal agents, foam breakers, dispersants, discoloration prevention Agents and the like.

(Spray method)
The manufacturing method of the rigid foam of this invention is a spray method. Various methods are known for producing foam by the spray method. Among these, airless spray foaming is preferred, in which the compounded liquid is mixed and foamed with a mixing head. Here, spray foaming is a foaming method in which a polyol system solution and a polyisocyanate compound are reacted while sprayed, and the reaction is completed in a short time by selecting a catalyst or the like. Spray foaming is often employed when constructing hard foam insulation on walls, ceilings, etc. at construction sites. Spray foaming has advantages such as manufacturing rigid foams directly at the construction site, thus reducing the construction cost, and being able to construct even on uneven construction surfaces. Specific construction examples include heat insulating materials for condominiums, office buildings, prefabricated refrigerated warehouses, etc. In recent years, they are also being used as heat insulating materials for highly airtight detached houses.

(Rigid foam)
The density of the rigid foam produced by the production method of the present invention is preferably 15 to ³⁰ kg / m ³ . This density can be reduced if a large amount of foaming agent is used, but if a large amount of foaming agent is used, the resulting rigid foam tends to shrink. However, the use of the polymer-dispersed polyol (W) described above is preferable because a rigid foam with little shrinkage and excellent dimensional stability can be easily produced even when the amount of foaming agent used is increased and the weight is reduced.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Of the following examples, Examples 1 and 2 are examples of producing polymer-dispersed polyols, Examples 3 to 25 are examples of producing rigid polyurethane foams, and Examples 26 to 46 are examples of producing rigid urethane-modified polyisocyanurate foams. . However, Examples 3-17 and Examples 26-40 represent Examples, and Examples 18-25 and Examples 41-46 represent Comparative Examples. Moreover, the unit of the numerical value of the part which showed prescription in the table | surface is a mass part. The raw materials used in Examples and Comparative Examples are as shown in each table, and the details are as follows. As abbreviations in the table, AN represents acrylonitrile, ST represents styrene, and VA represents vinyl acetate.

(Polyol compound)
Polyol AA1: Mannich Compound 1 was obtained by reacting 1.5 mol of formaldehyde and 2.2 mol of diethanolamine with 1 mol of nonylphenol. This Mannich compound 1 was subjected to ring-opening addition polymerization of propylene oxide (PO) and ethylene oxide (EO) in this order to obtain a Mannich polyol having a viscosity at 25 ° C. of 1000 mPa · s and a hydroxyl value of 300 mgKOH / g. The ratio of EO to the total amount of PO and EO at this time was 60% by mass.
Polyol AX2: The Mannich compound 1 was subjected to ring-opening addition polymerization of PO and EO in this order to obtain a Mannich polyol having a viscosity at 25 ° C. of 3000 mPa · s and a hydroxyl value of 300 mgKOH / g. The ratio of EO to the total amount of PO and EO at this time was 23% by mass.
Polyol AX3: With respect to the Mannich compound 1, PO and EO were subjected to ring-opening addition polymerization in this order to obtain a Mannich polyol having a viscosity at 25 ° C. of 500 mPa · s and a hydroxyl value of 300 mgKOH / g. The ratio of EO to the total amount of PO and EO at this time was 90% by mass.

Polyol AB1: Polyoxyethylene polyol having a hydroxyl value of 280 mgKOH / g, obtained by reacting only ethylene oxide as alkylene oxide using bisphenol A as an initiator.
Polyol AB2: Polyester polyol obtained by polycondensation of diethylene glycol and terephthalic acid and having a hydroxyl value of 250 mgKOH / g.

  Polyol X1: Polyoxyethylene poly having a hydroxyl value of 50 mgKOH / g and a proportion of oxyethylene groups of 55% by mass, obtained by mixing and reacting ethylene oxide and propylene oxide as alkylene oxide using glycerin as an initiator. Oxypropylene polyol.

Polyol YC1: Polyoxypropylene polyol having a hydroxyl value of 760 mgKOH / g, obtained by reacting only propylene oxide as alkylene oxide using ethylenediamine as an initiator.
Polyol YC2: Polyoxypropylene polyol having a hydroxyl value of 500 mgKOH / g, obtained by reacting only propylene oxide as alkylene oxide using ethylenediamine as an initiator.
Polyol YD3: Polyoxyethylene polyol having a hydroxyl value of 350 mgKOH / g, obtained by reacting only ethylene oxide as alkylene oxide using 1- (2-aminoethyl) piperazine as an initiator.

Polyol Z1: Polystyrene having a hydroxyl value of 300 mgKOH / g, obtained by reacting only propylene oxide as alkylene oxide using a mixture of sucrose and glycerin as the initiator (mixing ratio is 1.5: 1 by mass). Oxypropylene polyol.
Polyol Z2: A polyoxypropylene polyol having a hydroxyl value of 650 mgKOH / g, obtained by reacting only propylene oxide as an alkylene oxide using glycerin as an initiator.

(Foaming agent)
Blowing agent 1: HFC-245fa.
Foaming agent 2: HFC-365mfc.
Blowing agent 3: HFC-134a.

(Example 1)
The polyols shown in Table 1 were mixed and used. 70% by mass of this polyol mixture was charged into a 5 L pressure reactor and heated to 120 ° C. While maintaining the temperature, the remainder of the polyol mixture, and the mixture of monomers and AIBN shown in Table 1 were added over 4 hours under stirring. After completion of the addition, the mixture was stirred for 30 minutes while maintaining the temperature. The monomer reaction rate was 92%. After completion of the reaction, unreacted monomers were removed over 2 hours at a temperature of 120 ° C. and a pressure of 50 Pa. Thus, polyol W1 was obtained. The hydroxyl value of the polyol W1 was 325 mgKOH / g, and the viscosity at 25 ° C. was 4000 mPa · s.

(Example 2)
The polyols shown in Table 1 were mixed and used. This polyol mixture, a monomer shown in Table 1, and a mixture of AIBN were charged into a 5 L pressure reactor. The temperature was raised to 80 ° C. with stirring. The mixture was stirred for 10 hours while maintaining the temperature. The monomer reaction rate was 85%. After completion of the reaction, unreacted monomers were removed over 2 hours at a temperature of 110 ° C. and a pressure of 50 Pa. Thus, polyol W2 was obtained. The hydroxyl value of polyol W2 was 330 mgKOH / g, and the viscosity at 25 ° C. was 1500 mPa · s.

(Examples 3 to 25: Production examples of rigid polyurethane foam)
The polyols shown in Tables 2 to 4 were mixed and used. The foaming agents shown in Tables 2 to 4 were used. The following catalyst, foam stabilizer and flame retardant were added to and mixed with the polyol mixture and the foaming agent to obtain a polyol composition. As a catalyst, 2.0 parts by mass of a dipropylene glycol solution of triethylenediamine (triethylenediamine concentration 33%, trade name DABCO33LV), a mineral spirit solution of lead 2-ethylhexanoate (lead concentration: 20%, trade name: Nikka) 1.0 part by mass of 20% octix lead (manufactured by Nippon Chemical Industry Co., Ltd.) was used. As the foam stabilizer, 1.5 parts by mass of a silicone foam stabilizer (trade name: SH-193, manufactured by Toray Dow Corning Silicone) was used. As the flame retardant, 15 parts by mass of tris (2-chloropropyl) phosphate (trade name: TMCPP, manufactured by Daihachi Chemical Co., Ltd.) was used.

  As Examples 3 to 15 and 18 to 25, polymethylene polyphenyl polyisocyanate having a viscosity at 25 ° C. of 120 mPa · s (trade name: C-1155, manufactured by Nippon Polyurethane Industry Co., Ltd.) For No. 17, polymethylene polyphenyl polyisocyanate (trade name: MR-200, manufactured by Nippon Polyurethane Industry Co., Ltd.) having a viscosity at 25 ° C. of 180 mPa · s was used.

(Examples 26 to 46: Production example of hard polyisocyanurate)
The polyols shown in Tables 5 to 7 were mixed and used. Further, the foaming agents shown in Tables 5 to 7 were used. The following catalyst, foam stabilizer and flame retardant were added to and mixed with the polyol mixture and the foaming agent to obtain a polyol composition. As the catalyst, 2.0 parts by mass of N, N ′, N ″ -tris (dimethylaminopropyl) hexahydro-s-triazine (trade name: Polycat 41, manufactured by Air Products), and potassium 2-ethylhexanoate 4.0 parts by mass of diethylene glycol solution (potassium concentration 15%, trade name: PACCAT 15G, manufactured by Nippon Chemical Industry Co., Ltd.), mineral spirit solution of lead 2-ethylhexanoate (lead concentration: 20%, trade name: Nikkaoku) 2.0 parts by weight of Chicks Lead 20%, manufactured by Nippon Kagaku Sangyo Co., Ltd. 1.5 parts by weight of SH-193 was used as the foam stabilizer, and 20 parts by weight of TMCPP was used as the flame retardant. .

  Regarding Examples 26 to 38 and 41 to 46 as polyisocyanates, polymethylene polyphenyl polyisocyanate having a viscosity at 25 ° C. of 120 mPa · s / 25 ° C. (trade name: C-1155, manufactured by Nippon Polyurethane Industry Co., Ltd.) is used as an example. For 39 and 40, polymethylene polyphenyl polyisocyanate (trade name: MR-200, manufactured by Nippon Polyurethane Industry Co., Ltd.) having a viscosity at 25 ° C. of 180 mPa · s was used.

(Evaluation)
The above-mentioned polyol mixture and polyisocyanate are sprayed onto a board affixed to a wall surface by a spray method using a gas maker foaming machine (FF-1600) at a liquid temperature of 35 ° C. and a room temperature of 10 ° C. Each was manufactured. Specifically, after a lower spray layer of 1 mm thickness was applied to a 600 × 600 mm flexible board cooled to 10 ° C., two layers were further applied at a thickness of 25 mm.

A foam sample piece having a thickness of 40 mm and a length and width of 40 mm is cut across the skin layer when two layers are constructed at 25 mm, and the core density (unit: kg / m ³ ) and low-temperature shrinkage (unit:%) are cut from this sample piece. The high temperature shrinkage (unit:%) was evaluated. The low temperature shrinkage is -30 ° C, the dimensional change rate in the direction perpendicular to the foaming direction after 24 hours (horizontal to the board plane), and the high temperature shrinkage is 70 ° C, with respect to the foaming direction after 48 hours. Shows the rate of dimensional change in the vertical direction. The initial adhesion is evaluated by the degree of foam adhesion when the foam is peeled from the flexible board after 1 minute of construction. Good (strongly bonded) ○, poor (mostly bonded) Is not).

  Regarding flame retardancy, self-extinguishing properties (unit: mm) were measured for Tables 2 to 4 based on JIS-A-9511. Regarding Tables 5-7, the core part is cut out to a thickness of 10 mm, and a combustion test based on ISO-5600 Part 1 is performed with a cone calorimeter (manufactured by Toyo Seiki Seisakusho). Those showing flame retardancy were marked with ◯, and those not showing were marked with x. Further, the swelling state of the drum can was evaluated by filling the polyol system solution in a 200 L drum can so that the volume of the space was 1 and the volume occupied by the polyol mixture was 10 and heated at 45 ° C. for 2 weeks. The swelling state of the top plate of the drum can was confirmed by visual observation. As for the cell appearance, the produced foam was cut, and the internal cell state and the rough state of the bottom surface of the foam (adhesive surface with the board) were evaluated in three stages: good, normal, and poor.

  As shown in Tables 2 to 7, all of the rigid foams produced by the method for producing a rigid foam of the present invention exhibited good initial adhesion, dimensional stability, mechanical properties, and flame retardancy.

  The manufacturing method of the rigid foam which is lightweight and excellent in adhesiveness based on this invention is suitable for construction of the rigid foam by spray foaming constructed | assembled at a construction site.

Claims (7)

In a method of producing a rigid foamed synthetic resin by reacting and foaming a polyol and a polyisocyanate by a spray method in the presence of a foam stabilizer, a catalyst and a foaming agent,
Water is used as at least a part of the blowing agent, the amount of water used is 0.5 to 15 parts by mass with respect to 100 parts by mass of the polyol, and the following polyol (AA) is used as at least a part of the polyol. Manufacturing method of hard foam synthetic resin.
Polyol (AA): obtained by ring-opening addition polymerization of propylene oxide and ethylene oxide in this order to a Mannich compound obtained by reacting phenols, aldehydes and alkanolamines, and having a hydroxyl value of 100 to 400 mgKOH Polyether polyol in which the ratio of ethylene oxide to the total amount of propylene oxide and ethylene oxide is more than 55% by mass and 80% by mass or less.   The ratio of the raw material at the time of obtaining the said Mannich compound is 1-1.8 mol of aldehydes, and 2-2.5 mol of alkanolamines with respect to 1 mol of phenols, The rigid foam of Claim 1 A method for producing a synthetic resin.   The manufacturing method of the hard foam synthetic resin of Claim 1 or 2 whose hydroxyl value of the said polyol (AA) is 200-350 mgKOH / g.   The manufacturing method of the hard foam synthetic resin as described in any one of Claims 1-3 whose ratio of the ethylene oxide with respect to the total amount of the propylene oxide and ethylene oxide in the said polyol (AA) is 56-65 mass%.   The manufacturing method of the hard foam synthetic resin as described in any one of Claims 1-4 whose ratio of the said polyol (AA) is 10-100 mass% among polyols.   The method for producing a rigid foam synthetic resin according to any one of claims 1 to 5, wherein the polyisocyanate has a viscosity at 25 ° C of 50 to 150 mPa · s. The density of the manufactured hard foamed synthetic resin is 15-30 kg / m < ³ >, The manufacturing method of the hard foamed synthetic resin as described in any one of Claims 1-6.