JP4894321B2 - Manufacturing method of rigid foam synthetic resin - Google Patents

Description

  The present invention relates to a method for producing a rigid foamed synthetic resin such as rigid polyurethane foam.

  It is widely performed to produce a rigid foamed synthetic resin (hereinafter referred to as a rigid foam) such as a rigid polyurethane foam and a rigid polyisocyanurate foam by reacting a polyol compound and a polyisocyanate compound in the presence of a foaming agent or the like. ing. Here, various compounds are known as a foaming agent for producing a rigid foam. Previously, low-boiling fluorine-containing compounds have been mainly used.

  However, considering the burden on the environment, it is desirable to reduce the use of fluorine-containing compounds. Therefore, in order to reduce the amount of use, techniques for using a large amount of water as a blowing agent have been studied. However, when a rigid foam is produced using a large amount of water, physical properties are deteriorated. In particular, deterioration of dimensional stability due to foam shrinkage is remarkable. By increasing the density (setting it higher), it is possible to maintain the physical properties of the rigid foam, but in that case an increase in cost is inevitable.

  In order to prevent foam shrinkage, a method is known in which a polymer-dispersed polyol is added to a polyol having a high hydroxyl value (low molecular weight) to produce a rigid foam (Patent Document 1). The polymer-dispersed polyol is a polyol in which polymer fine particles are dispersed in a polyol such as polyether polyol or polyester polyol. Conventionally, it has been used as a raw material for polyurethane foam such as flexible foam or semi-rigid foam, and has been used to improve the mechanical properties of these polyurethane compositions. In the above-mentioned technique for producing a rigid foam having good dimensional stability by adding a polymer-dispersed polyol to a polyol having a high hydroxyl value, it is considered that the polymer fine particles have some favorable effect on foam shrinkage prevention.

  As a typical method for producing a polymer-dispersed polyol, the following methods are known. In a saturated polyol having no polymerizable unsaturated bond, a monomer having a polymerizable unsaturated bond is polymerized under the condition that an unsaturated polyol having a polymerizable unsaturated bond is also present. Remove. As the polyol, various polyether polyols and polyester polyols are known.

  The conventional polymer-dispersed polyol is a polyol having a low hydroxyl value (high molecular weight, for example, 50 mgKOH / g or less) used as a raw material for flexible foam or semi-rigid foam. Therefore, conventional low-hydroxyl group polymer-dispersed polyols tend to be poorly compatible with rigid foam polyols having a high hydroxyl value. As a result, when these are used in combination, the polyol and polymer fine particles having a low hydroxyl value are separated, or the polyol composition is thickened. That is, it has been difficult to use a conventional polymer dispersion polyol having a low hydroxyl value as a raw material for rigid foam.

In general, when a polymer-dispersed polyol is synthesized by polymerizing a monomer having a polymerizable unsaturated bond in a polyol, the higher the hydroxyl value of the polyol (the lower the molecular weight of the polyol), the less the particle stabilizing action by the polyol. In the process of growing the particles during polymerization, the particles are very easily aggregated to form an aggregate. For this reason, even when a high hydroxyl value polyol is used, a technique for producing a polymer-dispersed polyol in which polymer fine particles do not aggregate and stably disperse, and a technique for producing a foam using the polymer-dispersed polyol are proposed. (See Patent Documents 2, 3, 4, etc.). Further, even with these methods, the dispersion stability of the polymer fine particles is not sufficient, and a technique relating to a polymer-dispersed polyol in which the stability of the polymer fine particles is further improved has been proposed (see, for example, Patent Documents 5, 6, 7, and 8). .)
In addition, for the purpose of preventing foam shrinkage, a technique using a specific foam stabilizer is also proposed (see, for example, Patent Document 9).
JP 57-25313 A JP-A-2-240125 Japanese Examined Patent Publication No. 6-62797 Japanese Patent Publication No. 7-80986 Japanese Patent Laid-Open No. 11-60651 Japanese Patent Laid-Open No. 11-106447 JP-A-11-302340 JP 2004-137492 A JP 2001-240649 A

Regarding the techniques of Patent Documents 1 to 4, not only the dispersion stability of the polymer fine particles is not sufficient, but also a sufficient improvement effect is not seen with respect to foam shrinkage. Regarding the techniques of Patent Documents 5 to 8, an improvement effect is seen in both the dispersion stability of the polymer fine particles and the foam shrinkage improvement. However, when water is used as the foaming agent, there is an improvement effect on the shrinkage of the foam center part (hereinafter referred to as the core part), but on the shrinkage of the foam surface layer part (hereinafter referred to as the skin part). The improvement effect is insufficient. In particular, when the amount of water used is large, foam shrinkage of the skin portion becomes remarkable, and the improvement effect is insufficient. Furthermore, when water alone or water and carbon dioxide alone is used, the improvement effect is hardly seen. In addition, when the amount of water used is large, the heat insulation performance tends to deteriorate, and when water alone or only water and carbon dioxide gas are used in combination, the tendency becomes more remarkable. Moreover, regarding the technique of patent document 9, there exists a tendency for cell roughening to generate | occur | produce, and the tendency for heat insulation performance to worsen is seen.
That is, an object of the present invention is to solve the above-mentioned problems and to provide a method for producing a rigid foam that uses water as a foaming agent, is light in weight, has almost no foam shrinkage in the skin portion, and has excellent heat insulation performance.

The method for producing a rigid foamed synthetic resin according to the present invention is a method for producing a rigid foamed synthetic resin by reacting a polyol compound and a polyisocyanate compound in the presence of a foaming agent, a foam stabilizer and a catalyst. The following foam stabilizer (a) and the following foam stabilizer (b) are used as the foam stabilizer, using a polyol composition having a value of 100 to 700 mgKOH / g and in which polymer fine particles are stably dispersed. The foam stabilizer (a) is used in a proportion of 5 to 190 parts by mass with respect to 100 parts by mass of the agent (b), and 1 to 15 parts by mass of water is used as a foaming agent with respect to 100 parts by mass of the polyol compound. It is characterized by using. However, the foam stabilizer (a) is a foam stabilizer having a surface tension higher than 22 mN / m, and the foam stabilizer (b) is a foam stabilizer having a surface tension of 22 mN / m or less.

  Moreover, it is preferable that the said polyol composition contains the following polyol (AA) and / or the following polyol (AB). However, the polyol (AA) is a polyoxyalkylene polyol having a hydroxyl value of 100 to 700 mgKOH / g and produced by ring-opening addition polymerization of an alkylene oxide using an aromatic compound as an initiator. AB) is a polyester polyol having a hydroxyl value of 100 to 700 mgKOH / g, produced by polycondensation of a monomer containing an aromatic compound. In particular, at least one selected from the group consisting of a Mannich condensation product, diaminotoluene and bisphenol A is preferably used as the initiator of the polyol (AA).

  Moreover, it is preferable that the said polyol composition contains the following polyol (B). However, the polyol (B) is produced by ring-opening addition polymerization of alkylene oxide using at least one selected from the group consisting of aliphatic amines and alicyclic amines as an initiator, and has a hydroxyl value of 100 to 100. It is a polyoxyalkylene polyol which is 700 mg KOH / g. Moreover, it is preferable to use piperazine as an initiator of the polyol (B). Moreover, it is preferable to use only ethylene oxide as the alkylene oxide of the polyol (B).

  The polymer fine particles are preferably obtained by polymerizing a monomer having a polymerizable unsaturated bond. Moreover, it is preferable to manufacture by making a filling rate into 100-120 mass%. Furthermore, it is preferable that the hard foam synthetic resin obtained is a continuous production type board.

  According to the method for producing a rigid foamed synthetic resin of the present invention, when a lightweight rigid foam is produced using water as a foaming agent, a rigid foam excellent in heat insulation performance is obtained with almost no foam shrinkage in the skin part. It is done.

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

(Polyol compound)
As the polyol compound in the present invention, a polyol composition having a hydroxyl value of 100 to 700 mgKOH / g and in which polymer fine particles are stably dispersed is used.
In the present invention, the polyol composition preferably contains a polyol (AA) and / or a polyol (AB). By using this polyol (AA) and / or polyol (AB), flame resistance can be imparted to the resulting rigid foam.

  In the present invention, the polyol (AA) is a polyoxyalkylene polyol having a hydroxyl value of 100 to 700 mgKOH / g, produced by ring-opening addition polymerization of an alkylene oxide using an aromatic compound as an initiator.

  An aromatic compound is used as an initiator for producing the polyol (AA). Here, the aromatic compound means a compound having an aromatic ring. Here, the aromatic ring may be a ring consisting of only carbon atoms or a ring containing atoms other than carbon atoms such as nitrogen atoms. Examples of the ring consisting of only carbon atoms include a benzene ring and a naphthalene ring. Examples of the ring containing an atom other than a carbon atom include a pyridine ring. The aromatic compound may be a condensed compound or a non-condensed compound.

  Condensation compounds include Mannich condensation products, which are reaction products of phenols, alkanolamines and aldehydes, resol-type initial condensates obtained by condensation-bonding phenols with excess formaldehydes in the presence of an alkali catalyst. Examples include a benzylic type initial condensate reacted in a non-aqueous system when synthesizing a type initial condensate, a novolak type initial condensate obtained by reacting excess phenols with formaldehyde in the presence of an acid catalyst, and the like. 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.

Non-condensable compounds include polyphenols such as bisphenol A and resorcinol; aromatic amines such as diaminotoluene, diethyldiaminotoluene, and diaminodiphenylmethane.
Among these, it is preferable to use at least one selected from the group consisting of a Mannich condensation product, diaminotoluene and bisphenol A as an initiator for producing the polyol (AA).

  Examples of the alkylene oxide used for producing the polyol (AA) include ethylene oxide, propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane, and styrene oxide. Of these, propylene oxide and ethylene oxide are preferable, and propylene oxide alone or a combination of propylene oxide and ethylene oxide is particularly preferable.

  The hydroxyl value of the polyol (AA) is 100 to 700 mgKOH / g, preferably 200 to 600 mgKOH / g. When the hydroxyl value of the polyol (AA) is within the above range, it is preferable because sufficient flame retardancy can be imparted while maintaining the mixing property of the polyol compound. Moreover, 2-8 are preferable and, as for the average functional group number of a polyol (AA), 2-6 are more preferable.

In the present invention, the polyol (AB) is a polyester polyol having a hydroxyl value of 100 to 700 mgKOH / g produced by polycondensation of a monomer containing an aromatic compound. That is, as a raw material monomer for producing this polyol (AB), a polyhydric alcohol having an aromatic ring and / or a polyvalent carboxylic acid having an aromatic ring is used. As the polyhydric alcohol having an aromatic ring, a diol having an aromatic ring is preferable. Specific examples include diols obtained by adding ethylene oxide to bisphenol A. Moreover, as polyvalent carboxylic acid which has an aromatic ring, dicarboxylic acid is preferable. Specific examples include phthalic acids such as terephthalic acid.
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 (AA) is within the above range, it is preferable because sufficient flame retardancy can be imparted while maintaining the mixing property of the polyol compound.

  In the polyol composition (100% by mass) used in the present invention, the total proportion of the polyol (AA) and the polyol (AB) is preferably 7 to 90% by mass, more preferably 10 to 80% by mass, and 15 to 15%. 60 mass% is more preferable. If the total ratio of the polyol (AA) and 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. Moreover, there is no restriction | limiting in particular in the ratio of a polyol (AA) and a polyol (AB), but the ratio of the polyol (AA) of the sum total (100 mass%) of a polyol (AA) and a polyol (AB) is 15-15. 100 mass% is preferable. In particular, in the polyurethane formulation described later, the proportion of the polyol (AA) is preferably 50 to 100% by mass, particularly preferably 75 to 100% by mass. It is easy to improve the strength of the rigid foam obtained by setting the ratio within this range. In the polyisocyanurate formulation, the proportion of the polyol (AA) is preferably 15 to 80% by mass, particularly preferably 15 to 50% by mass. It is easy to improve the flame retardance of the rigid foam obtained by setting it as the range of this ratio.

  In the present invention, the polyol composition preferably contains the polyol (B). In the present invention, the polyol (B) has a hydroxyl value of 100 to 100 produced by ring-opening addition polymerization of alkylene oxide using at least one selected from the group consisting of aliphatic amines and alicyclic amines as an initiator. It is a polyoxyalkylene polyol which is 700 mg KOH / g. By using this polyol (B), the dissolution stability of water and the polyol compound is improved, the reactivity between water and the polyisocyanate compound is improved, and a lower density rigid foam can be produced. It is done.

  The hydroxyl value of the polyol (B) is 100 to 700 mgKOH / g, preferably 250 to 700 mgKOH / g. When the hydroxyl value of the polyol (B) is within the above range, the compatibility between the polyol compound and water can be secured, the reactivity of the polyol compound can be increased, and the adhesiveness of the rigid foam can be easily secured, which is preferable. Moreover, 2-8 are preferable and, as for the average functional group number of a polyol (B), 2-6 are more preferable. Here, the average number of functional groups means the number average of active hydrogen atoms of the initiator.

  In the polyol composition used in the present invention, the proportion of the polyol (B) is preferably 2 to 90% by mass, more preferably 5 to 75% by mass, and further preferably 5 to 50% by mass. If the ratio of a polyol (B) is 2 mass% or more, it is preferable at the point which the adhesiveness of a rigid foam is favorable. Moreover, if the ratio of a polyol (B) is 90 mass% or less, the intensity | strength of a rigid foam is fully acquired and it is preferable.

  The initiator used for the production of the polyol (B) is at least one selected from the group consisting of aliphatic amines and alicyclic amines. Here, as the initiator, an alicyclic amine is more preferable. Examples of the aliphatic amine include alkylamines and alkanolamines. Examples of alkylamines include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetraamine. Examples of alkanolamines include monoethanolamine, diethanolamine, triethanolamine, 1-amino-2-propanol, and aminoethylethanolamine. 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 formation reaction, and by using it as an initiator for the polyol (B), 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.

  As the alkylene oxide used for the production of the polyol (B), ethylene oxide, propylene oxide and the like are used, and among these, only ethylene oxide is preferable. By using only ethylene oxide, the affinity between the polyol (B) and water is improved, and the dissolution stability between water and the polyol is improved. Further, by using only ethylene oxide, the hydroxyl group of the polyol (B) becomes a primary hydroxyl group, the reactivity of the polyol (B) is increased, and the adhesiveness is improved.

  In the present invention, a polyol composition in which polymer fine particles are stably dispersed is used as the polyol compound. The polyol composition in which the polymer fine particles are stably dispersed may be produced by dispersing the polymer fine particles in the polyol or the like. The polyol in which the polymer fine particles are dispersed (hereinafter referred to as polymer-dispersed polyol), the polyol or the like, However, the latter is particularly preferable from the viewpoint of the stability of the polyol.

Polyols used for the production of polymer-dispersed polyols (hereinafter referred to as polyol (W)) include polyether polyols, polyester polyols, hydrocarbon-based polymers having a hydroxyl group at the end, etc., especially consisting only of polyether polyols. Or a combination of a small amount of a polyester polyol or a hydrocarbon-based polymer having a hydroxyl group at the terminal as a main component thereof is preferable. However, the polyether polyol used in the polyol (W) may be the polyol (AA) or the polyol (B). Similarly, the polyol (AB) may be used as the polyester polyol.
Examples of polyether polyols include polyether polyols obtained by adding cyclic ethers such as alkylene oxides to initiators such as polyhydroxy compounds such as polyhydric alcohols and polyhydric phenols and amines.

Specific examples of the initiator include the following compounds, cyclic ether adducts thereof, and mixtures of two or more thereof.
Ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,4-butanediol, 1,6-hexanediol, water, glycerin, trimethylolpropane, 1 , 2,6-hexanetriol, pentaerythritol, diglycerin, tetramethylolcyclohexane, methyl glucoside, sorbitol, mannitol, dulcitol, sucrose, triethanolamine and other polyhydric alcohols; bisphenol A, phenol-formaldehyde initial condensate, etc. Polyphenols: piperazine, aniline, monoethanolamine, diethanolamine, isopropanolamine, aminoethylethanolamine, ammonia, amino Methylpiperazine, aminoethylpiperazine, ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, xylylenediamine, diphenylmethanediamine, diethylenetriamine, amino compounds such as triethylene tetramine.

Examples of the cyclic ether used in the present invention include 3- to 6-membered cyclic ether compounds having one oxygen atom in the ring, and specific examples include the following compounds.
Ethylene oxide, propylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, trimethylethylene oxide, tetramethylethylene oxide, butadiene monooxide, styrene oxide, α-methylstyrene oxide, epichlorohydrin, epifluorohydrin, epibromo Hydrin, glycidol, butyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl ether, 2-chloroethyl glycidyl ether, o-chlorophenyl glycidyl ether, ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, cyclohexene oxide, dihydronaphthalene oxide, vinyl Compounds having a 3-membered cyclic ether group such as cyclohexene monooxide; oxeta Compounds having a 4- to 6-membered cyclic ether group, such as ethylene, tetrahydrofuran and tetrahydropyran.
Preferably, it is a compound (monoepoxide) having one 3-membered cyclic ether group, and particularly preferable compounds are alkylene oxides having 2 to 4 carbon atoms, such as ethylene oxide, propylene oxide, isobutylene oxide, 1-butene oxide, 2- Butene oxide.
Two or more kinds of these cyclic ethers can be used in combination, and in that case, they can be mixed and reacted or sequentially reacted. Particularly preferred cyclic ethers are alkylene oxides having 2 to 4 carbon atoms, particularly propylene oxide, or a combination of propylene oxide and ethylene oxide.

  Examples of the polyester polyol include a polyester polyol obtained by polycondensation of a polyhydric alcohol and a polyvalent carboxylic acid. In addition, there are polycondensation of hydroxycarboxylic acid, polymerization of cyclic ester (lactone), polyaddition of cyclic ether to polycarboxylic acid anhydride, polyester polyol by transesterification of waste polyethylene terephthalate, and the like.

  The average hydroxyl value of the polyol (W) used in the production of these polymer-dispersed polyols is 200 to 800 mgKOH / g, preferably 250 to 750 mgKOH / g. When the average hydroxyl value of the polyol (W) is lower than this range (when it is small, ie, when it has a high molecular weight), the produced polymer-dispersed polyol is poorly compatible with the polyol for a rigid polyurethane foam having a high hydroxyl value. Since the polyol (polymer fine particles) separates or thickens, it tends to be difficult to use as a raw material for rigid polyurethane foam. When the average hydroxyl value of the polyol (W) used for producing the polymer-dispersed polyol is high, it is difficult to obtain a polymer-dispersed polyol in which polymer fine particles are stably dispersed.

In this invention, it is preferable that 5 mass% or more of these polyols (W) is polyether polyol (X). However, 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 polyether polyol (X) is preferably obtained by using a polyhydric alcohol as an initiator and adding ethylene oxide or ethylene oxide and another cyclic ether. As the polyhydric alcohol, glycerin, trimethylolpropane, 1,2,6-hexanetriol and the like are preferable. As other cyclic ethers, propylene oxide, isobutylene oxide, 1-butene oxide and 2-butene oxide are preferable, and propylene oxide is particularly preferable.

The hydroxyl value of the polyether polyol (X) is preferably 67 mgKOH / g or less, particularly preferably 60 mgKOH / g or less. The lower limit of the hydroxyl value of the polyether polyol (X) is preferably 5 mgKOH / g or more, more preferably 8 mgKOH / g or more, particularly preferably 20 mgKOH / g or more, and most preferably 30 mgKOH / g or more.
In the polyether polyol (X), the oxyethylene group content with respect to the entire polyether polyol (X) is preferably 40% by mass or more. When the oxyethylene group content is 40% by mass or more, it is easy to obtain a polymer-dispersed polyol in which polymer fine particles are stably dispersed. The oxyethylene group content is particularly preferably 50% by mass or more, and most preferably 55% by mass or more. The upper limit of the oxyethylene group content is preferably about 100% by mass or less, and more preferably 90% by mass or less.

  The content of the polyether polyol (X) is preferably 5% by mass or more in the polyol (W). When the amount of the polyether polyol (X) is 5% by mass or more, it is easy to obtain a polymer-dispersed polyol with good dispersibility. The content of the polyether polyol (X) in the polyol (W) is particularly preferably 10% by mass or more. The upper limit of the amount of the polyether polyol (X) is not particularly limited, but the average hydroxyl value of the polyol (W) is preferably 200 to 800 mgKOH / g.

  The polyol (W) is more preferably a mixture of 5 to 40% by mass of polyether polyol (X) and 60 to 95% by mass of polyol having a hydroxyl value of 400 to 850 mgKOH / g, and 5 to 30 polyether polyol (X). Particularly preferred is a mixture of 70% to 95% by weight of a polyol having a weight% and a hydroxyl value of 400 to 850 mg KOH / g. Most preferred is a mixture of 5 to 30% by mass of polyether polyol (X) and 70 to 95% by mass of polyol having a hydroxyl value of 400 to 750 mg KOH / g.

There are, for example, two methods for producing a polymer-dispersed polyol using the polyol (W). The first method is a method in which a monomer having a polymerizable unsaturated bond in the polyol (W) is polymerized in the presence of a solvent, if necessary, to directly deposit particles, and the second method is a method in which particles are deposited as necessary. In this method, a monomer having a polymerizable unsaturated bond is polymerized in a solvent in the presence of a stabilizing grafting agent to precipitate particles, and then the polyol (W) and the solvent are substituted to obtain a stable dispersion. . In the present invention, either method can be adopted, and the former method is particularly preferable.
The monomer having a polymerizable unsaturated bond used in the present invention is usually a monomer having one polymerizable unsaturated bond, but is not limited thereto.

Specific monomers include cyano group-containing monomers such as acrylonitrile, methacrylonitrile, 2,4-dicyanobutene-1, styrene monomers such as styrene, α-methylstyrene, and halogenated styrene; acrylic acid, methacrylic acid, or the like Acrylic esters such as acrylamide and methacrylamide; vinyl ester monomers such as vinyl acetate and vinyl propionate; isoprene, butadiene and other diene monomers; unsaturated fatty acid esters such as maleic acid diester and itaconic acid diester Vinyl halides such as vinyl chloride, vinyl bromide and vinyl fluoride; vinylidene halides such as vinylidene chloride, vinylidene bromide and vinylidene fluoride; methyl vinyl ether, ethyl vinyl ether and isopropyl Vinyl ether monomers or vinyl ether; and other than the above olefin, there is a halogenated olefin.
A combination of 20 to 90% by mass of acrylonitrile and 10 to 80% by mass of other monomers is preferred, and styrene, alkyl acrylate ester, alkyl methacrylate ester and vinyl acetate are preferred as other monomers. Two or more of these other monomers may be used in combination.

The amount of the monomer used is not particularly limited, but is preferably an amount such that the polymer concentration of the polymer-dispersed polyol obtained from the polyol (W) is about 1 to 50% by mass, particularly preferably 2 to 45% by mass. Most preferably, it is 10-30 mass%.
For polymerization of a monomer having a polymerizable unsaturated bond, a polymerization initiator of a type that initiates polymerization by generating free radicals is usually used.
Specifically, for example, 2,2-azobis-isobutyronitrile (AIBN), 2,2-azobis-2-methylbutyronitrile, 2,2-azobis-2,4-dimethylvaleronitrile, benzoyl peroxide, diisopropyl Examples include peroxydicarbonate, acetyl peroxide, di-tert-butyl peroxide, persulfate and the like. In particular, AIBN and 2,2-azobis-2-methylbutyronitrile are preferable.

The polymerization reaction is carried out at a temperature equal to or higher than the decomposition temperature of the polymerization initiator, usually 80 to 160 ° C, preferably 90 to 150 ° C, particularly preferably 100 to 130 ° C.
Conventionally, in a method for producing a polymer-dispersed polyol, a part of a polyol is charged into a reactor, and while stirring, a mixture of the remaining polyol, a monomer having a polymerizable unsaturated bond, a polymerization initiator, and the like is gradually added to the reactor. A batch method in which polymerization is performed by feeding, and a mixture of a polyol, a monomer having a polymerizable unsaturated bond, a polymerization initiator and the like are continuously fed to a reactor with stirring, and the polymer-dispersed polyol composition produced at the same time is continuously produced. There is a continuous method of discharging from the reactor, and the present invention can be produced by either method.

  In general, the higher the polymer concentration, the more likely the particles are agglomerated in the process of growing the particles during polymerization of the monomer, and the aggregates are more likely to be formed. In order to prevent this, the polymer-dispersed polyol can be produced in the presence of a solvent.

Examples of the solvent include alcohols such as methanol, ethanol, isopropanol, butanol, cyclohexanol, and benzyl alcohol; aliphatic hydrocarbons such as pentane, hexane, cyclohexane, and hexene; aromatic hydrocarbons such as benzene, toluene, and xylene; acetone , Ketones such as methyl ethyl ketone and acetophenone, esters such as ethyl acetate and butyl acetate; ethers such as isopropyl ether, tetrahydrofuran, benzyl ethyl ether, acetal, anisole and methyl tert-butyl ether; chlorobenzene, chloroform, dichloroethane, 1, Halogenated hydrocarbons such as 1,2-trichlorotrifluoroethane; nitro compounds such as nitrobenzene; nitriles such as acetonitrile and benzonitrile; Methylamine, triethylamine, tributylamine, amines such as dimethylaniline; N, N- dimethylformamide, amides such as N- methyl pyrrolidone; dimethyl sulfoxide, and the like sulfur compounds such as sulfolane.
In the present invention, these solvents can be used alone or in combination. After the polymerization of the monomer having a polymerizable unsaturated bond is completed, the solvent is removed. Solvent removal is usually performed by heating under reduced pressure. However, it can also be performed under normal pressure heating or reduced pressure at room temperature. At this time, unreacted monomers are also removed together with the solvent.

Although a polymer-dispersed polyol in which polymer particles are stably dispersed can be obtained by the production method as described above, a stable dispersion may be difficult to obtain depending on the monomers used. Furthermore, a stabilizer or a grafting agent can be used to improve the dispersion stability of the particles.
As the stabilizer or grafting agent, a compound having an unsaturated bond in the molecule is preferable. High molecular weight polyol or monool obtained by reacting an alkylene oxide with an active hydrogen compound having an unsaturated bond-containing group such as vinyl group, allyl group, isopropyl group as an initiator; maleic anhydride, itaconic anhydride to polyol , High molecular weight obtained by reacting unsaturated carboxylic acid such as maleic acid, fumaric acid, acrylic acid, methacrylic acid or the like, or its anhydride, and then adding alkylene oxide such as propylene oxide or ethylene oxide as necessary Polyols or monools of 2-hydroxyethyl acrylate, butenediol and other unsaturated alcohols and other polyols and polyisocyanates; allyl glycidyl ether and other unsaturated epoxy compounds and polyols; . These compounds preferably have a hydroxyl group but are not limited thereto.

  The hydroxyl value of the polymer-dispersed polyol is preferably 200 to 800 mgKOH / g, more preferably 200 to 750 mgKOH / g, and particularly preferably 250 to 750 mgKOH / g. It is usually lower than the polyol (W) used as the base polyol.

  The polymer-dispersed polyol of the present invention obtained as described above is preferably one that does not cause separation in a stationary state for 1 month or more, particularly 2 months or more. The reason why the polymer-dispersed polyol is excellent in dispersion stability in this way can be presumed to be because the size of the polymer fine particles obtained by polymerizing the monomer having a polymerizable unsaturated bond is fine and uniform.

  In the present invention, a polyol composition having a hydroxyl value of 100 to 700 mgKOH / g and stably dispersing fine polymer particles is used as the polyol compound. Here, the hydroxyl value (average hydroxyl value) of the polyol composition is 100 to 700 mgKOH / g, preferably 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, 0.05-5 mass% is preferable among a polyol composition, and 0.2-2 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 a polyol composition is obtained by mixing a polyol (W) having a concentration of polymer fine particles of 25% by mass, the proportion of the polyol (W) is preferably 0.2 to 20% by mass. 8-8 mass% is more preferable.

  As the above-mentioned polyol composition, in addition to the polymer-dispersed polyol obtained from the polyol (W), the above-mentioned polyol (AA), polyol (AB), and polyol (B) may be mixed. These active hydrogen-containing compounds may be used in combination. Here, other active hydrogen-containing compounds include polyols and polyamines. The polyols that may be used together here are any polyol other than polyol (AA), polyol (AB), and polyol (B).

  In the present invention, the composition of a suitable polyol composition (the total polyol composition is 100% by mass) can be exemplified by the following ranges. However, the polymer-dispersed polyol is preferably a polymer-dispersed polyol obtained by polymerizing a monomer having a polymerizable unsaturated bond in the polyol (W). The concentration of the polymer fine particles in the polyol (W) is preferably 20 to 30% by mass.

  In the polyurethane formulation described below, the polyol (AA) is 20 to 40% by mass, the polyol (AB) is 0 to 5% by mass, the polyol (B) is 30 to 50% by mass (of the polyol (B), particularly aminoalkyl) It is preferable to use 10 to 40% by mass of a polyol obtained using piperazine substituted with a group as an initiator, 1 to 10% by mass of polyol (W), and 10 to 30% by mass of other polyols. Moreover, in the polyisocyanurate prescription mentioned later, 10-40 mass% of polyol (AA), 50-75 mass% of polyol (AB), 0-20 mass% of polyol (B) (of the polyol (B), In particular, a polyol obtained by using piperazine substituted with an aminoalkyl group as an initiator is used in an amount of 0 to 20% by mass), polyol (W) is used in an amount of 1 to 10% by mass, and other polyols are used in an amount of 0 to 20% by mass. preferable.

(Foaming agent)
In the present invention, water is used as the foaming agent. As the blowing agent, a low boiling point hydrocarbon compound, a low boiling point fluorine-containing compound, and an inert gas can be used in combination. In the present invention, it is preferable to use only water as the foaming agent.
The amount of water used as the blowing agent is preferably 1 to 15 parts by mass, more preferably 2 to 13 parts by mass, and particularly preferably 4 to 12 parts by mass with respect to 100 parts by mass of the polyol compound. If the usage-amount of water is 1 mass part or more, it is preferable at the point of weight reduction of the rigid foam obtained. Moreover, if the usage-amount is 15 mass parts or less, it is easy to make the mixability of water and a polyol compound favorable, and it is preferable.

Examples of the low-boiling hydrocarbon compound include butane, pentane, hexane, and cyclohexane. 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. Examples of the inert gas include air, nitrogen, carbon dioxide gas and the like. Of these, carbon dioxide is preferable. The addition state of the inert gas may be a liquid state, a supercritical state, or a subcritical state.
As for the usage-amount of an inert gas, 1-100 mass parts is preferable with respect to 100 mass parts of polyols. Moreover, the usage-amount of a hydrocarbon compound has preferable 1-40 mass parts with respect to 100 mass parts of polyols. Moreover, the usage-amount of a fluorine-containing compound has preferable 1-50 mass parts with respect to 100 mass parts of polyols.

(Polyisocyanate compound)
In the present invention, the polyisocyanate compound is not particularly limited, but aromatic, alicyclic and aliphatic polyisocyanates having two or more isocyanate groups; mixtures of two or more of the above polyisocyanates; And modified polyisocyanates obtained by modifying. 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-type modified products, isocyanurate-modified products, urea-modified products, carbodiimide-modified products, and the like. Of these, TDI, MDI, crude MDI, or modified products thereof are preferred.

  The amount of the polyisocyanate compound used is represented by 100 times the number of isocyanate groups with respect to the total number of active hydrogens of the polyol compound and other active hydrogen compounds (usually, the value represented by 100 times is referred to as the isocyanate index), 300 is preferred. Here, in the polyurethane formulation mainly using a urethanization catalyst as a catalyst, the amount of the polyisocyanate compound used is an isocyanate index, preferably 50 to 140, more preferably 60 to 130. Further, in a polyisocyanurate formulation (urethane-modified polyisocyanurate formulation) mainly using a catalyst that promotes a trimerization reaction of an isocyanate group as a catalyst, the polyisocyanate compound is used in an isocyanate index, preferably 120 to 300, 150 -250 is 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, the following foam stabilizer (a) and the following foam stabilizer (b) are used in combination as the foam stabilizer. Here, the foam stabilizer (a) is a foam stabilizer having a surface tension higher than 22 mN / m, and the foam stabilizer (b) is a foam stabilizer having a surface tension of 22 mN / m or less.
As a ratio at the time of using together said 2 types of foam stabilizer, 5-190 mass parts of foam stabilizers (a) are used with respect to 100 mass parts of foam stabilizer (b). As for this ratio, it is preferable to use 5-130 mass parts of foam stabilizer (a) with respect to 100 mass parts of foam stabilizer (b), and it is especially preferable to use 40-100 mass parts. In the said ratio, when the ratio of foam stabilizer (a) is less than the said range, shrinkage | contraction will generate | occur | produce easily in the skin part of a foam. On the other hand, if the ratio of the foam stabilizer (a) is more than the above range, cell foaming occurs in the foam, and at the same time, the heat insulation performance tends to deteriorate. The total amount of the foam stabilizer (the total of the foam stabilizer (a) and the foam stabilizer (b)) is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polyol compound.

(Other ingredients)
In the present invention, any compounding agent can be used in addition to the above-described polyol compound, polyisocyanate compound, 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.

(Molding method)
In the manufacturing method of this invention, it is preferable to manufacture as a filling rate of 100-120 mass%. Here, the filling rate (packing rate) is the ratio (unit: mass) of the reactive composition filled in the unit volume based on the total density when the reactive composition for producing the foam is freely foamed. %). Specifically, for example, when the total density at the time of free foaming is 40 kg / m ³ , when the volume of 1 m ³ is filled with 40 kg of the reactive composition, the filling rate becomes 100% by mass, Similarly, when 44 kg of the reactive composition is filled, the filling rate becomes 110% by mass. That is, when a rigid foam having a volume of 1 m ³ is produced using the reactive composition of this example, the filling rate is 100% by mass if the total mass is 40 kg, and if the total mass is 44 kg, the filling rate is 110%. % By mass.
In the present invention, the filling rate is preferably 100 to 120% by mass, more preferably 100 to 110% by mass, and further preferably 100 to 105% by mass. When the filling rate is less than 100%, the closed cell rate is lowered, and thus the heat insulation performance tends to be lowered. When the filling rate is higher than 120%, the closed cell rate is increased, so the dimensional stability of the foam is poor. Tend to be.

(Foaming device)
As a manufacturing method of the rigid foam of the present invention, normal hand foaming or a foaming apparatus may be used. As the foaming apparatus, either a high pressure foaming apparatus or a low pressure foaming apparatus can be used. The reaction conditions may be appropriately selected, but the reaction temperature is preferably 0 to 50 ° C, more preferably 15 to 45 ° C.
The manufacturing method of the present invention is suitable for manufacturing a continuous production type board. Here, the board means a laminate in which a rigid foam is sandwiched between two face materials, and is suitable as a heat insulating material in architectural applications. In particular, a thick foam layer is used as a building board, but a thin foam layer (for example, thinner than 30 mm) is often used as a siding material.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. Of the following examples, Examples 1 to 4 are production examples of a polymer-dispersed polyol. Examples 5 to 61 are production examples of rigid polyurethane foam. Examples 62-103 are production examples of rigid polyisocyanurate foams.
Of these examples, Examples 5 to 19, Examples 24 to 38, Examples 43 to 57, Examples 62 to 71, Examples 76 to 85, and Examples 90 to 99 are examples, and Examples 21 to 23 and Example 40 are examples. -42, Examples 59-61, Examples 73-75, Examples 87-89, and Examples 101-103 are comparative examples. Examples 20, 39, 58, 72, 86, and 100 are reference examples.
The unit of the numerical value of the part showing the prescription in the table is part by mass. The raw materials used in Examples and Comparative Examples are as shown in each table, and the details are as follows. As abbreviations, AN represents acrylonitrile, Vac represents vinyl acetate, MMA represents methyl methacrylate, PO represents propylene oxide, EO represents ethylene oxide, and EO group content represents oxyethylene group content. AMBN represents 2,2-azobis-2-methylbutyronitrile and is a polymerization initiator.

(Foaming agent)
-Foaming agent 1: HFC-245fa.
-Foaming agent 2: HFC-365mfc.
-Foaming agent 3: cyclopentane.

(Polyol)
Polyol AA1: A polyether polyol having a hydroxyl value of 350 mgKOH / g and an EO group content of 25% by mass, obtained by adding EO, PO, and EO to tolylenediamine in this order.
Polyol AA2: The hydroxyl value obtained by adding PO and EO in this order to the Mannich condensation product obtained by reacting nonylphenol, formaldehyde and diethanolamine in a molar ratio of 1.0 to 1.4 to 2.1. A polyether polyol having 450 mg KOH / g and an EO group content of 30% by mass.
Polyol AA3: A polyether polyol having a hydroxyl value of 350 mgKOH / g obtained by adding PO to tolylenediamine.
Polyol AB1: Polyester polyol having a hydroxyl value of 250 mgKOH / g, obtained by polycondensation of diethylene glycol and terephthalic acid.
Polyol B1: A polyether polyol having a hydroxyl value of 760 mgKOH / g obtained by adding PO to ethylenediamine.
Polyol B2: A polyether polyol obtained by adding EO to 1- (2-aminoethylpiperazine) and having a hydroxyl value of 350 mgKOH / g.
Polyol B3: A polyether polyol obtained by adding PO to monoethanolamine and having a hydroxyl value of 350 mgKOH / g.
Polyol B4: A polyether polyol obtained by adding PO to ethylenediamine and having a hydroxyl value of 300 mgKOH / g.
Polyol E1: A polyether polyol having a hydroxyl value of 650 mgKOH / g obtained by adding PO to glycerin.
Polyol E2: A polyether polyol having a hydroxyl value of 380 mgKOH / g, obtained by adding only PO to a mixture of sucrose and glycerin (mass ratio 5: 4).
Polyol E3: Polyether polyol having a hydroxyl value of 400 mgKOH / g, obtained by adding PO to pentaerythritol.
Polyol E4: A polyether polyol having a hydroxyl value of 430 mgKOH / g obtained by adding PO to glycerin.
Polyol X1: A polyether polyol obtained by randomly adding PO and EO to glycerin and having a hydroxyl value of 50 mgKOH / g and an EO group content of 70% by mass.

(Polyol (W))
As the polyol (W), a mixture of polyols E1 and X1, or a mixture of B1, E1, and X1 was used. Using these polyols (W), polymer-dispersed polyols were produced as follows.

(Example 1: Production example of polymer-dispersed polyol)
After all of the polyol, monomer and AMBN shown in Table 1 were charged in a 5 L pressurized reaction vessel, the temperature was raised while stirring, and the reaction was continued for 10 hours while maintaining the reaction solution at 80 ° C. The monomer reaction rate was 80% or more. After the completion of the reaction, the unreacted monomer was removed by heating under reduced pressure at 110 ° C. and 20 Pa for 2 hours to produce a polymer-dispersed polyol.

(Examples 2 to 4: Examples of production of polymer-dispersed polyol)
70 mass% of the polyol mixture shown in Table 1 is charged into a 5 L pressure reaction tank, and the remaining polyol mixture and the monomer and AMBN mixture shown in Table 1 are fed over 2 hours while stirring at 120 ° C. Then, stirring was continued for about 0.5 hours at the same temperature after completion of all the feeds. In any example, the monomer reaction rate was 80% or more. After completion of the reaction, the unreacted monomer was removed by heating under reduced pressure at 120 ° C. and 20 Pa for 2 hours to produce a polymer-dispersed polyol.
Table 1 shows the hydroxyl value (unit: mg KOH / g) of the polymer-dispersed polyol produced in each example, the viscosity at 25 ° C. (unit: mPa · s), and the dispersion stability of the produced polymer-dispersed polyol itself.

  In the following tables, the polymer-dispersed polyols produced in Examples 1 to 4 are written in order as follows. Example 1: Polyol W1, Example 2: Polyol W2, Example 3: Polyol W3, Example 4: Polyol W4.

(Examples 5 to 61: Production example of rigid polyurethane foam)
In the formulations shown in Tables 2 to 4, a polyol mixture (a mixture of a polymer-dispersed polyol and another polyol) and a foaming agent were used. The water in the table corresponds to the foaming agent (hereinafter the same).
A polyol composition was prepared by adding and mixing a polyol mixture, a foaming agent, and the following catalyst, foam stabilizer and flame retardant.

As the catalyst, N, N, N ′, N′-tetramethylhexanediamine (trade name: TOYOCAT MR, manufactured by Tosoh Corporation) was used. The amount used was such that the gel time was 25 seconds.
As the foam stabilizer, the following were used as silicone foam stabilizers. Foam stabilizer a1: Trade name SZ-1605 (manufactured by Toray Dow Corning Silicone Co., Ltd., surface tension 26.3 mN / m). Foam stabilizer a2: trade name SZ-1654 (manufactured by Toray Dow Corning Silicone Co., Ltd., surface tension 23.4 mN / m). Foam stabilizer b1: Trade name SH-193 (manufactured by Toray Dow Corning Silicone, surface tension 21.3 mN / m).
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 the polyisocyanate compound, polymethylene polyphenyl polyisocyanate (crude MDI) (trade name: MR-200, manufactured by Nippon Polyurethane Industry Co., Ltd.) was used. The amount of polyisocyanate compound used was set to 110 in terms of isocyanate index.
The liquid temperature of both raw materials was kept at 20 ° C. In Table 2, the above-mentioned raw materials were mixed and charged in an aluminum mold whose temperature was adjusted to 60 ° C. in Tables 3 and 4, and a rigid polyurethane foam was produced. . The inner dimensions of the mold are 400 mm long × 600 mm wide × 50 mm thick. The filling rate was 102 ± 2%.

(Examples 62 to 103: Production Example of Rigid Polyisocyanurate Foam)
In the formulations shown in Tables 5 to 7, a polyol mixture (a mixture of a polymer-dispersed polyol and a polyol) and a foaming agent were used. A polyol composition was prepared by adding and mixing a polyol mixture, a foaming agent, and the following catalyst, foam stabilizer and flame retardant.

As the catalyst, N, N ′, N ″ -tris (dimethylaminopropyl) hexahydro-S-triazine (trade name: Polycat 41, manufactured by Air Products) and diethylene glycol solution of potassium 2-ethylhexanoate (potassium concentration 15) %, Trade name: PACCAT 15G, manufactured by Nippon Kagaku Sangyo Co., Ltd.) at a mass ratio of 2/3, and the amount used was such that the gel time was 25 seconds.
As the foam stabilizer, the following were used as silicone foam stabilizers. Foam stabilizer a1: Trade name SZ-1605 (manufactured by Toray Dow Corning Silicone Co., Ltd., surface tension 26.3 mN / m). Foam stabilizer a2: trade name SZ-1654 (manufactured by Toray Dow Corning Silicone Co., Ltd., surface tension 23.4 mN / m). Foam stabilizer b1: Trade name SH-193 (manufactured by Toray Dow Corning Silicone, surface tension 21.3 mN / m). As the flame retardant, 20 parts by mass of TMCPP was used.

As the polyisocyanate compound, polymethylene polyphenyl polyisocyanate (crude MDI) (trade name: MR-200, manufactured by Nippon Polyurethane Industry Co., Ltd.) was used. The amount of polyisocyanate compound used was set to 160 in terms of isocyanate index.
The liquid temperature of both raw materials was kept at 20 ° C. In Table 5, the above-mentioned raw materials were mixed and charged in an aluminum mold whose temperature was adjusted to 40 ° C in Tables 6 and 7, and the hard polyisocyanurate foam was formed. Manufactured. The inner dimensions of the mold are 400 mm long × 600 mm wide × 50 mm thick. The filling rate was 102 ± 2%.

(Physical property evaluation of rigid foam)
The obtained rigid foam (rigid polyurethane foam or rigid polyisocyanurate foam) has a total density (unit: kg / m ³ ), high temperature shrinkage (unit:%), and thermal conductivity at 24 ° C. (Kf, unit) as heat insulation performance. : MW / mK), foam appearance, and skin portion shrinkage are shown in Tables 2-7.

  High temperature shrinkage was measured by a method according to ASTM D 2126-75. As a sample, 100 mm in length, 100 mm in width, and 50 mm in thickness (the upper and lower surfaces in the thickness direction are provided with skins) were used. The foam sample was stored at 70 ° C., and the dimensional change rate in the thickness direction after 24 hours was shown. However, a negative numerical value means shrinkage, and a large absolute value means a large dimensional change.

The thermal conductivity at 24 ° C. (unit: mW / m · K) was measured using a thermal conductivity measuring device (Auto Lambda HC-074, manufactured by Eiko Seiki Co., Ltd.) in accordance with JIS A1412.
Regarding the appearance of the foam, the overall cell uniformity is ◎ for those with good condition (cells that are fine and uniform), ○ for slightly better, and × for those with many rough cells and many bad places. evaluated. In addition, when there is much cell roughness, it exists in the tendency for heat conductivity to be high, and it exists in the tendency for it to be inferior to heat insulation performance.

The skin part shrinkage was evaluated by visual observation of the degree of shrinkage of the skin part (foam edge part) of the foam left at room temperature for 1 week. An evaluation was given as ◯ when there was no contraction, Δ when there was some warping due to contraction, and x when there was large contraction and large warping.
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 had a low density, and exhibited good dimensional stability and thermal conductivity. Regarding the shrinkage, none of the rigid foams produced by the method for producing a rigid foam according to the present invention showed a good appearance with neither high temperature shrinkage nor skin part shrinkage. In addition, the laminate board manufactured by the manufacturing method of the rigid foam of the reference example was slightly inferior in heat insulation performance, although shrinkage was not observed on the facet.

(Example 1 of rigid foam production by the board method)
Rigid foams were produced by the board method using the compositions prepared in Examples 5-20, Examples 24-39, Examples 43-58, Examples 62-72, Examples 76-86, and Examples 90-100. The raw material was uniformly dispersed while traversing through a spray nozzle type mixing head between the upper and lower surface materials carried by the inverse line belt conveyor. After the dispersion, after-curing was performed in the curing zone to form a continuous laminate board. As a result, the continuous laminate boards obtained using the compositions prepared in Examples 5 to 19, Examples 24 to 38, Examples 43 to 57, Examples 62 to 71, Examples 76 to 85, and Examples 90 to 99 contracted to the facet and the like. Was not seen, and showed good dimensional stability, heat insulation performance, and foam appearance. On the other hand, although the continuous laminate board obtained using the composition adjusted in Examples 20, 39, 58, 72, 86, and 100 did not show shrinkage on the facet or the like, the heat insulating performance was slightly inferior.

(Example 2 of rigid foam production by the board method)
In the same manner as in Production Example 1, 5-20, Examples 24-39, Examples 43-58, Examples 62-72, Examples 76-86, and Examples 90-100 were used. The carbon dioxide in the state was used in combination. 2% by mass of carbon dioxide gas with respect to 100% by mass of the polyol composition was used in a supercritical state at a liquid temperature of 40 ° C. and a pressure of 7 MPa. In the same manner as in Production Example 1, the raw materials were uniformly dispersed while traversing through a spray nozzle type mixing head. After dispersion, after-curing was performed in the curing zone, and a continuous laminate board was formed. As a result, even when carbon dioxide in a supercritical state was used in combination, the compositions prepared in Examples 5 to 19, Examples 24 to 38, Examples 43 to 57, Examples 62 to 71, Examples 76 to 85, and Examples 90 to 99 were used. The continuous laminate board obtained by using did not show any shrinkage on the facet or the like as in Production Example 1, and exhibited good dimensional stability, heat insulation performance, and foam appearance. On the other hand, although the continuous laminate board obtained using the composition adjusted in Examples 20, 39, 58, 72, 86, and 100 did not show shrinkage on the facet or the like, the heat insulating performance was slightly inferior.

The method for producing a rigid foam according to the present invention uses water as a foaming agent, and is lightweight, yielding a rigid foam that has little foam shrinkage at the skin portion and excellent heat insulation performance.

Claims (7)

In a method for producing a rigid foam synthetic resin by reacting a polyol compound and a polyisocyanate compound in the presence of a foaming agent, a foam stabilizer and a catalyst,
As a polyol compound, a hydroxyl value is 100 to 700 mgKOH / g, and a polyol composition in which polymer fine particles are stably dispersed is used.
As the foam stabilizer, the following foam stabilizer (a) and the following foam stabilizer (b) are used in a proportion of 5 to 190 parts by mass of the foam stabilizer (a) with respect to 100 parts by mass of the foam stabilizer (b). In addition, and
1 to 15 parts by mass of water is used as a foaming agent with respect to 100 parts by mass of a polyol compound .
Foam stabilizer (a): Foam stabilizer having a surface tension higher than 22 mN / m.
Foam stabilizer (b): Foam stabilizer having a surface tension of 22 mN / m or less. The method for producing a rigid foam synthetic resin according to claim 1, wherein the polyol composition contains the following polyol (AA) and / or the following polyol (AB).
Polyol (AA): A polyoxyalkylene polyol having a hydroxyl value of 100 to 700 mgKOH / g, produced by ring-opening addition polymerization of alkylene oxide using an aromatic compound as an initiator.
Polyol (AB): Polyester polyol having a hydroxyl value of 100 to 700 mgKOH / g, produced by polycondensation of a monomer containing an aromatic compound.   The manufacturing method of the hard foam synthetic resin of Claim 2 using at least 1 sort (s) chosen from the group which consists of a Mannich condensation product, diaminotoluene, and bisphenol A as an initiator of the said polyol (AA). The manufacturing method of the hard foam synthetic resin as described in any one of Claims 1-3 with which the said polyol composition contains the following polyol (B).
Polyol (B): produced by ring-opening addition polymerization of alkylene oxide using at least one selected from the group consisting of aliphatic amines and alicyclic amines as an initiator, and having a hydroxyl value of 100 to 700 mgKOH / g A polyoxyalkylene polyol.   The manufacturing method of the hard foam synthetic resin of Claim 4 using piperazine as an initiator of the said polyol (B).   The method for producing a rigid foam synthetic resin according to claim 4 or 5, wherein only ethylene oxide is used as the alkylene oxide of the polyol (B). The method for producing a rigid foam synthetic resin according to any one of claims 1 to 6, wherein the polymer fine particles are obtained by polymerizing a monomer having a polymerizable unsaturated bond.