JP5422280B2 - Foamable composition for polyurethane foam and polyurethane foam - Google Patents

Description

  The present invention relates to a foamable composition for polyurethane foam and polyurethane foam, and more particularly to a technique for improving the properties of polyurethane foam obtained by foaming with water.

  Conventionally, polyurethane foam has been used mainly as a thermal insulation member for insulation, such as building interior and exterior wall materials and panels, insulation for metal siding and electric refrigerators, buildings and condominiums. -Practical use for heat insulation and dew condensation prevention for enclosures, walls, ceilings, roofs, etc. for freezers, and for infusion pipes. Such a polyurethane foam generally includes a polyol component comprising a polyol compound liquid (premix liquid) in which a polyol component is blended with a foaming agent and, if necessary, various auxiliary agents such as a catalyst, a foam stabilizer, and a flame retardant, and a polyisocyanate. The components are mixed continuously or intermittently with a mixing device to form a foamable composition for polyurethane foam, which is foamed and cured by a slab foaming method, an injection foaming method, a spray foaming method, a laminate continuous foaming method, or the like. It is manufactured.

  In addition, the foamable composition for polyurethane foam has a hydrofluorocarbon-based foaming agent (for example, HFC-245fa) which is an alternative chlorofluorocarbon that causes little or no destruction of the ozone layer as a foaming agent because of the environmental problem of destruction of the stratospheric ozone layer. , HFC-365mfc, etc.) are used. However, based on the assumption that the use of alternative chlorofluorocarbons will be limited in the near future, in recent years, carbon dioxide (carbon dioxide) has been used as a substitute for some or all of existing blowing agents such as alternative chlorofluorocarbon blowing agents. Polyurethane foams manufactured in the future are being investigated. For example, Patent Documents 1 and 2 disclose a polyurethane foam produced by a so-called “water foaming method” in which carbon dioxide generated by a chemical reaction between a polyisocyanate component and water is used as a foaming agent. Patent Document 3 discloses a polyurethane foam produced by using, as a foaming agent, carbon dioxide generated by a reaction between water and a polyisocyanate component, and carbon dioxide in a supercritical state, a subcritical state, or a liquid state. Has been revealed.

  However, polyurethane foam produced using carbon dioxide generated by water as a blowing agent is basically inferior in heat insulation performance than polyurethane foam produced by other foaming methods. In addition, there is a problem that the characteristics such as dimensional stability are not sufficient.

  In addition, water as a blowing agent source that generates carbon dioxide has a very small contribution to lowering the viscosity of the polyol compound liquid compared to other solvent-based blowing agents, so carbon dioxide is used as the blowing agent. In order to reduce the viscosity of the polyol compound itself and use a low-viscosity polyol such as a polyether polyol in combination, the viscosity of the polyol compound liquid can be practically used. It is necessary to make it low. In particular, as a polyol compound, when using a phenol resin-based polyol, which is noted from the viewpoint of imparting heat resistance and flame retardancy to the foam, the viscosity of the polyol compound itself is high, so that the lowering of viscosity is conventionally achieved. For example, Patent Documents 4 to 6 propose phenol resin polyols obtained by adding an alkylene oxide to a phenol resin. However, in these documents, no examination has been made on the above-described problem in characteristics of a polyurethane foam produced using carbon dioxide as a foaming agent.

  On the other hand, in Patent Document 7, a specific amine compound is used as an initial foamability improver in order to achieve improvement in initial foamability, improvement in workability, and reduction in foam density in the production of water-foamed rigid urethane spray foam. In which ethylene diamine and, in addition, pentamethyldiethylenetriamine and / or bis (dimethylaminoethyl) ether as a foaming catalyst are used in combination with such an initial foamability improver. Has been revealed. Patent Document 8 discloses that in a rigid polyurethane foam obtained by foaming with water or hydrocarbon, polyalkylene polyamine such as ethylenediamine or diethylenetriamine is added within a predetermined range, so that only the initial reactivity is remarkably increased. As a result, it has been clarified that foam performance such as thermal conductivity and adhesiveness can be improved. However, even if measures such as those proposed in Patent Documents 7 and 8 are taken, there is a limit to the improvement in adhesiveness and heat insulation performance at low temperatures, and in terms of dimensional stability, etc. The problem was inherent.

JP-A-4-227645 JP 2004-59641 A JP 2004-107376 A Japanese Patent Laid-Open No. 5-170851 JP-A-11-217431 Japanese Patent Laid-Open No. 60-48842 JP-A-11-130830 JP 11-279254 A

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is the heat insulation performance of polyurethane foam manufactured using carbon dioxide generated by water. It is possible to advantageously improve the dimensional stability of the polyurethane foam and to provide a foaming composition for polyurethane foam that can exhibit excellent adhesion at low temperatures, and to foam the foaming composition for polyurethane foam. Another object of the present invention is to provide a polyurethane foam that achieves excellent heat insulation performance and dimensional stability that is cured.

  And as a result of intensive investigations by the present inventors to solve the above-mentioned problems, a phenol resin polyol obtained by adding an alkylene oxide to a novolak type phenol resin is used as a polyol compound constituting the polyol component. In addition, the combined use of bis (dimethylaminoethyl) ether and diethylenetriamine as catalysts significantly improves the heat insulation performance and dimensional stability of the resulting polyurethane foam, and further improves the adhesion at low temperatures. As a result, the present invention has been completed.

  That is, the present invention is a foamable composition used for the production of a polyurethane foam obtained by reacting a polyol component containing a polyol compound and a catalyst with a polyisocyanate component and foaming with water, A polyurethane characterized in that the polyol compound contains a phenol resin polyol obtained by adding an alkylene oxide to a novolak type phenol resin, and further contains bis (dimethylaminoethyl) ether and diethylenetriamine as the catalyst. The foamable composition for foam is the gist thereof.

  In addition, according to one of the preferable embodiments of the foamable composition for polyurethane foam according to the present invention, the content ratio of the bis (dimethylaminoethyl) ether and the diethylenetriamine is 85/15 to 15 / It will be 85.

  According to another preferred embodiment of the foamable composition for polyurethane foam according to the present invention, the alkylene oxide added to the novolac type phenol resin is ethylene oxide or propylene oxide or both of them.

  Furthermore, according to another preferred embodiment of the foamable composition for polyurethane foam according to the present invention, the polyol compound further comprises an aromatic diamine-based polyol obtained by adding an alkylene oxide to an aromatic diamine. Including.

  Furthermore, in the foamable composition for polyurethane foam according to the present invention, preferably, the polyol component further contains an organosilicon compound.

  And this invention also makes the gist of the polyurethane foam obtained by foaming and curing such a foamable composition for polyurethane foam, and the polyurethane foam thus obtained is: Its thermal conductivity (initial value) is advantageously less than 0.023 W / (m · K).

  As described above, in the foamable composition for polyurethane foam according to the present invention, although it is foamed using water, a phenol resin obtained by adding an alkylene oxide to a novolak type phenol resin as a polyol compound of a polyol component. A conventional polyol in which the thermal conductivity (initial value) of the resulting polyurethane foam is foamed with water by using bis (dimethylaminoethyl) ether and diethylenetriamine as catalysts together with a system polyol is used. In addition to being lower than the thermal conductivity (initial value) of the polyurethane foam, the thermal insulation performance can be effectively improved, and in addition, the dimensional stability of the resulting polyurethane foam can be significantly improved. .

  Moreover, in such a foamable composition for polyurethane foam according to the present invention, the adhesiveness of the polyurethane foam obtained therefrom at low temperature can be further advantageously improved, Thereby, the foaming operation in a cold district or winter can be performed even more advantageously.

  Moreover, in the polyurethane foam according to the present invention, it is possible to enjoy the same effects as described above, since it is formed using the foamable composition for polyurethane foam as described above, and the heat insulation performance and its dimensional stability. Can be advantageously improved.

  Hereinafter, the foamable composition for polyurethane foam according to the present invention and the polyurethane foam obtained using the same will be described in detail.

  First, the foamable composition for polyurethane foam according to the present invention is foamed using at least water, contains a predetermined phenol resin-based polyol as a polyol compound as a constituent component of the polyol component, and a catalyst. As mentioned above, two of the specific compounds described later are used in combination.

  Among them, the above phenol resin-based polyol used as a polyol compound which is a constituent component of the polyol component in the present invention is obtained by adding an alkylene oxide to a novolac type phenol resin. In addition, as a novolak-type phenol resin used for the preparation of such a phenol resin-based polyol, advantageously, 1-50 mass%, preferably 3-35 mass% of free phenols are used from the viewpoint of lowering the viscosity. More preferably, a material containing 5 to 30% by mass is employed. This is because if the content of free phenols is less than 1% by mass, it is difficult to effectively reduce the viscosity, and the resulting foamable composition for polyurethane foam may not be usable. This is because, if the amount exceeds 50% by mass, the polyurethane foam becomes too soft and tends to deteriorate the moldability.

  Such a novolak-type phenol resin is prepared by blending, for example, phenols and aldehydes at a ratio of 0.3 to 1.0 mol with respect to 1 mol of phenols, and then an acid catalyst. And then reacting under predetermined reaction conditions (temperature and time), and if necessary, by subjecting it to dehydration under reduced pressure, it is advantageously produced as an initial condensate of a novolac type phenol resin. . Here, the initial condensate is a phenol resin having a relatively low molecular weight, and is a condensate having about 2 to 10 phenol skeleton or a mixture of unreacted phenols in one molecule. The method for producing such novolak-type phenolic resin (initial condensate) is not limited to the above-described method, and a predetermined proportion of the above-mentioned free phenols is present in the resulting novolak-type phenolic resin. It can be produced by appropriately setting reaction conditions and reaction environment (for example, normal pressure, reduced pressure, pressurization, presence / absence of coexistence of inert gas, stepwise or sequential reaction, etc.). Furthermore, it is also possible to adjust the content ratio of free phenols as described above by adding phenols separately to the condensate after completion of the reaction, if necessary.

  The phenols used in the production of the novolak type phenolic resin are not particularly limited, and generally phenol is adopted. For example, cresol, ethylphenol, xylenol, p- One kind of alkylphenols such as t-butylphenol, octylphenol, nonylphenol, dodecylphenol, p-phenylphenol or the like can be used alone or in admixture of two or more kinds, or one kind of such alkylphenols. The above and phenol can also be used together. Furthermore, halogenated phenols such as m-chlorophenol and o-bromophenol, polyphenols such as resorcinol, catechol, hydroquinone and phloroglicinol, bisphenol A [2,2-bis (4-hydroxyphenyl) propane], Bisphenol F (4,4'-dihydroxydiphenylmethane) and other bisphenols, resorcinol, catechol, bisphenol A, bisphenol F and other refined phenol compounds, α-naphthol, β-naphthol, β-hydroxyanthracene Can be used alone or in admixture of two or more, or one or more of them can be used in combination with phenol or alkylphenol.

  On the other hand, the aldehydes to be reacted with the phenols are not particularly limited, and generally one or both of formalin and paraformaldehyde is used, but other formaldehydes are used as necessary. (For example, trioxane, tetraoxane, polyoxymethylene, etc.), glyoxal and the like can be used alone or in combination.

  In addition, oxalic acid is suitable as the acid catalyst used in the production of the novolak type phenol resin, but in addition, organic sulfonic acid (for example, p-toluenesulfonic acid), organic carboxylic acid (for example, acetic acid, etc.) ) Divalent metal (eg, magnesium, zinc, lead, etc.) salt, divalent metal chloride, divalent metal oxide, inorganic acid (eg, hydrochloric acid, sulfuric acid, etc.), etc. Of course, two or more of these may be used in combination.

  In the present invention, the phenolic resin-based polyol used as one of the polyol components is a novolak-type phenolic resin produced as described above, and an alkylene such as ethylene oxide or propylene oxide in the presence of a basic catalyst. This is obtained by addition reaction of oxide, and advantageously, a predetermined alkylene oxide is added to the phenolic hydroxyl group portion of the novolak-type phenol resin containing free phenols, so that the phenolic hydroxyl group is formed. It becomes a phenol resin-based polyol converted into an alcoholic hydroxyl group. Thus, the addition of a predetermined alkylene oxide modifies the phenol resin and further improves the hydrophilicity of the polyol component. As a result, the phenol resin polyol uses water as a foaming agent source. It is not only suitable as a polyol used in the foaming method, but also has excellent mixing properties with the polyisocyanate component described below.

  The phenol resin-based polyol is preferably 130 to 450 mg KOH / g so that the hydroxyl value is advantageously 100 to 600 mg KOH / g by appropriately selecting the blending amount of the predetermined alkylene oxide. More preferably, it is configured to be 160 to 450 mgKOH / g. If the hydroxyl value is too low, the foam obtained by using it becomes too soft, the moldability tends to be poor, and the desired polyurethane foam tends not to be obtained. Conversely, the hydroxyl value is high. This is because if the viscosity is too high, the viscosity is not sufficiently lowered and the miscibility with the polyisocyanate component tends to deteriorate. In addition, the viscosity of the phenolic resin polyol also varies in accordance with the hydroxyl value, but the viscosity of the phenolic resin polyol used in the present invention is in the range of 500 to 30000 mPa · s / 25 ° C. .

  Here, as the alkylene oxide used for the production of the phenol resin-based polyol, ethylene oxide, propylene oxide, butylene oxide and the like are generally exemplified, and are appropriately selected according to the properties of the obtained foam. However, ethylene oxide, propylene oxide, and combinations thereof are particularly preferably employed from the viewpoint of the hydrophilicity of the phenol resin polyol. Moreover, generally the compounding quantity of such an alkylene oxide will be suitably selected in the range used as 1-20 times equivalent with respect to the phenolic hydroxyl group of a novolak-type phenol resin.

  The basic catalyst used in the production of the phenol resin polyol, in other words, used in the addition reaction between the novolak type phenol resin and a predetermined alkylene oxide, is, for example, sodium hydroxide or potassium hydroxide. Alkaline catalysts such as barium hydroxide and calcium hydroxide can be suitably employed, and at least one of them can be appropriately selected and used, but of course, these are limited. It goes without saying that it is not.

  An aromatic diamine-based polyol that is suitably used as another polyol compound together with such a phenol resin-based polyol adds an alkylene oxide such as ethylene oxide or propylene oxide to the aromatic diamine according to a known method. Is obtained. In other words, this aromatic diamine-based polyol is a polyfunctional polyether polyol compound having a terminal hydroxyl group obtained by ring-opening addition of a predetermined alkylene oxide to an aromatic diamine as an initiator.

  In addition, as the aromatic diamine as an initiator that gives such an aromatic diamine-based polyol, various known aromatic diamine compounds can be used, specifically, generically called tolylenediamine, In addition to various methyl substituents of phenylenediamine, derivatives in which substituents such as methyl, ethyl, acetyl, benzoyl are introduced to the amino group, 4,4′-diaminodiphenylmethane, p-phenylenediamine, Examples thereof include o-phenylenediamine and naphthalenediamine. Of these, tolylenediamine is preferably used for enhancing the properties of the resulting polyurethane foam.

  By the way, as described above, various aromatic diamine-based polyols obtained by adding a predetermined alkylene oxide such as ethylene oxide or propylene oxide to an aromatic diamine are commercially available. Examples of the polyol include products such as Sannix HA-501, HM-550, and HM-551 (all of which are products of Sanyo Chemical Industries, Ltd.). It will be used by appropriately selecting from the products. The hydroxyl value of the aromatic diamine-based polyol is preferably 200 to 600 mgKOH / g, and the viscosity is preferably 500 to 30000 mPa · s / 25 ° C.

  In the present invention, such an aromatic diamine-based polyol is preferably used as a polyol compound together with the above-described phenol resin-based polyol. The resin-based polyol is used in a proportion of 20% by mass or more, preferably 30% by mass or more of the entire polyol compound, and therefore the total amount thereof is 40% by mass or more, preferably 60% by mass of the entire polyol compound. In order to better achieve the object of the present invention, it is desirable to be used in such a ratio that occupies% or more. Of these, the phenol resin polyol and the aromatic diamine polyol are preferably used in a mass ratio of 3/7 to 7/3. In addition, in the blending ratio of these phenol resin-based polyol and aromatic diamine-based polyol, if the amount of phenol resin-based polyol increases too much, the effect of improving dimensional stability decreases, and the amount of aromatic diamine-based polyol increases. If it is too high, the effect of improving the thermal conductivity and flame retardancy will decrease, which is not desirable.

  In the present invention, as the polyol compound which is a constituent component of the polyol component, the above-described phenol resin-based polyol or a combination thereof and an aromatic diamine-based polyol are used. Other known polyol compounds can be used at the same time as long as they do not adversely affect the excellent action and effect of the use of. For example, such other known polyol compounds include known polyether polyols such as aliphatic polyether polyols, aliphatic amine polyether polyols, aromatic polyether polyols, or polyhydric alcohols. Ring-opening polymerization of polycarboxylic acid-based polyester polyols, lactones, etc. obtained by reacting with acid, adipic acid, sebacic acid, maleic acid, phthalic acid, terephthalic acid, trimellitic acid, dimer acid and other polycarboxylic acids Known polyester polyols such as the obtained lactone polyester polyol can be exemplified.

［但し、式中、Ｒ¹ 〜Ｒ¹²は炭素数１〜３のアルキル基を表し、同一であっても、異なっていても良い。また、ｎは０〜５０である。］ In the foamable composition for polyurethane foam according to the present invention, advantageously, the phenol resin-based polyol as described above or the aromatic diamine-based polyol as described above is used as at least a polyol compound, and further Various conventionally known organosilicon compounds are added and contained, thereby contributing to improvement in properties such as heat insulation performance of the foam obtained. Among such organosilicon compounds, in particular, specific organosilicon compounds represented by the following general formulas (I) and (II) are preferably used, thereby improving heat insulation performance, Improvement of long-term stability is realized even more advantageously. Particularly, the temporal change of the thermal conductivity, for example, the difference between the initial value and the value after 2 months is 0.0030 W / (m · K) or less, preferably Therefore, it is possible to advantageously realize the characteristics of 0.0025 W / (m · K) or less.

[In the formula, R ¹ to R ¹² represents an alkyl group having 1 to 3 carbon atoms, may be the same or different. N is 0-50. ]

The organosilicon compound represented by the general formula (I) that realizes such preferable characteristics is a monoalkoxytrialkylsilane, and the substituted alkyl group includes a methyl group, an ethyl group, and a propyl group. However, a product manufactured and sold by Toray Dow Corning Co., Ltd .: SS2010 (trimethylmethoxysilane) is particularly preferably used. Moreover, the organosilicon compound represented by the general formula (II) is a polyalkylpolysiloxane in which the number n of basic structural units is 0 to 50, preferably 0 to 10, and each alkyl substituent is , Methyl group, ethyl group, and propyl group. Particularly preferred are those in which all alkyl groups are methyl groups. For example, a product manufactured and sold by Toray Dow Corning Co., Ltd .: SH200 0.6 cst (n = 0), SH200 1 cst (n = 1), SH200 1.5 cst (n = 2.4), SH200 2 cst (n = 3.4), SH200 3 cst (n = 5.2), SH200 5 cst (n = 8.2) can be exemplified, but SH200 0.6 cst (n = 0) to SH200 2 cst (n = 3.4) is more preferable. The substituents R ^{1 to} R ¹² in the organosilicon compounds represented by the general formulas (I) and (II) may be the same or different.

  Moreover, said specific organosilicon compound may be used individually, respectively, and may be used in combination of both. Of course, there is no problem even if two or more compounds of the same genus are used in combination. Further, the amount of the specific organosilicon compound is difficult to determine uniquely depending on the type, curing mode, foam physical properties, foamed form, etc., but in general, per 100 parts by mass of the polyol compound, It will be selected in the range of 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass. This is because if the compounding amount of the organosilicon compound is too small, the effect of the use cannot be sufficiently achieved, and if the compounding amount is too large, the effect of improving the long-term stability of the heat insulation performance has reached its peak. Because it is expensive, it is not economical.

  Furthermore, the foamable composition for polyurethane foam according to the present invention is added with water as a forming source of carbon dioxide, which is a foaming agent for foam formation, according to the water foaming method. Then, if necessary, carbon dioxide in a subcritical state or a supercritical state is added together with water as the carbon dioxide forming source, and is introduced into the foamable composition for polyurethane foam, as is well known. Is also possible.

  When such water foaming is employed, water as a foaming agent source (carbon dioxide forming source) generates carbon dioxide gas used for foam formation by reaction with a polyisocyanate component described later. And contributes slightly to the decrease in the viscosity of the phenol resin polyol. The blending amount of water for such water foaming can be appropriately set so as to obtain a desired foam density. Usually, all polyols including phenolic resin-based polyols and aromatic diamine-based polyols used as necessary The amount can be appropriately set in the range of 0.5 to 12 parts by mass, preferably 1 to 10 parts by mass, and more preferably 2 to 8 parts by mass with respect to 100 parts by mass of the compound. In addition, if the blending amount of water is less than 0.5 parts by mass with respect to 100 parts by mass of all polyol compounds including phenol resin polyols, the amount of carbon dioxide gas generated is not sufficient, and conversely 12 parts by mass. If it exceeds the above range, foam may be weakened due to an extreme decrease in density.

  Moreover, the polyisocyanate component containing the polyisocyanate compound which reacts with polyol compounds, such as a phenol resin-type polyol, and produces | generates a polyurethane is used for the foamable composition for polyurethane foams according to this invention. This polyisocyanate compound is an organic isocyanate compound having two or more isocyanate groups (NCO groups) in the molecule. For example, diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, tolylene diisocyanate, polytolylene polyisocyanate, xylylene Aromatic polyisocyanates such as diisocyanate and naphthalene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, urethane prepolymer having an isocyanate group at the molecular end, isocyanurate of polyisocyanate A modified body, a carbodiimide modified body, etc. can be mentioned. These polyisocyanate compounds may be used alone or in combination of two or more. In general, polymethylene polyphenylene polyisocyanate (crude MDI) is preferably used from the viewpoints of reactivity, economy, and handling properties.

  The blending ratio of the polyisocyanate component containing such a polyisocyanate compound and the polyol component containing the above-mentioned phenol resin-based polyol, etc. will be changed depending on the type of foam (for example, polyurethane, polyisocyanurate). The NCO / OH index (equivalent ratio) indicating the ratio between the isocyanate group (NCO) of the polyisocyanate compound and the hydroxyl group (OH) of the polyol compound (total of each polyol) is in the range of about 0.9 to 2.5. It sets suitably so that it may become.

  The foamable composition for polyurethane foam according to the present invention includes, as a catalyst, bis (dimethyl) as well as a polyol component and a polyisocyanate component containing the above-mentioned phenol resin-based polyol, and water as a carbon dioxide forming source. Aminoethyl) ether and diethylenetriamine are used in combination, and a catalyst composed of these two components is blended.

  Specifically, when water is used as a carbon dioxide forming source (foaming agent source), if it is required to generate carbon dioxide generated by the reaction of a polyisocyanate compound and water at an early stage, these poly A catalyst having an action of promoting the reaction between an isocyanate compound and water, a so-called foaming catalyst, is advantageously used. In the present invention, in particular, as such a catalyst, bis (dimethyl (Aminoethyl) ether and diethylenetriamine were used in combination, thereby improving the heat insulation properties and dimensional stability of the resulting foam, and also advantageously improving adhesion at lower temperatures It was possible.

  Further, bis (dimethylaminoethyl) ether and diethylenetriamine as such a catalyst are desirably used in a mass ratio of 85/15 to 15/85. This is because if the use ratio (content ratio) of the bis (dimethylaminoethyl) ether and diethylenetriamine is outside the above range, the synergistic effect of the combined use of these two components may not be exhibited sufficiently. Moreover, as a total of the usage-amount of those bis (dimethylamino ethyl) ether and diethylenetriamine, normally with respect to 100 mass parts of all the polyol compounds containing a phenol resin type polyol, an aromatic diamine type polyol, etc. as needed. About 0.5 to 15 parts by mass is preferable. If the total amount used is less than 0.5 parts by mass, the contribution to improvement of foamability and adhesiveness at low temperatures is small, and if it exceeds 15 parts by mass, the reaction rate becomes too fast and useful. It becomes difficult to obtain a simple foam.

  In order to promote the reaction between the polyisocyanate compound and the polyol compound, a resinification catalyst is advantageously used. The resinification catalyst is appropriately selected and used according to the type of foam. For example, a urethanization catalyst and an isocyanurate catalyst are used alone, or these are used in combination. Examples of the urethanization catalyst include tertiary amine, dibutyltin dilaurate, ethylmorpholine, triethylenediamine, tetramethylhexamethylenediamine, bismuth octylate (bismuth 2-ethylhexylate), bismuth neodecanoate, bismuth neodecanoate, and naphthenic acid. Fatty acid bismuth salts such as bismuth, lead naphthenate and the like can be mentioned. Examples of the isocyanuration catalyst include fatty acid alkali metal salts such as hydroxyalkyl quaternary ammonium salts, potassium octylate and sodium acetate, tris ( And (dimethylaminopropyl) hexahydrotriazine. These resination catalysts may be used alone or in combination of two or more. In general, the blending amount of the resinification catalyst is desirably about 0.1 to 15 parts by mass with respect to 100 parts by mass of all polyol compounds.

  In addition, the foamable composition for polyurethane foam according to the present invention may further include a foam stabilizer, a foaming agent, a flame retardant, for example, a formaldehyde scavenger such as urea and melamine, and a finer bubble, if necessary. Various kinds of conventionally known auxiliaries such as an agent, a plasticizer, and a reinforcing base material can be appropriately selected and blended.

  Among them, the foam stabilizer is used for uniformly adjusting the cell structure of the polyurethane foam, and here, silicone and nonionic surfactant are suitably employed. Specific examples include polyoxyalkylene-modified dimethylpolysiloxane, polysiloxaneoxyalkylene copolymer, polyoxyethylene sorbitan fatty acid ester, castor oil ethylene oxide adduct, lauryl fatty acid ethylene oxide adduct, etc. Species are used alone or in combination of two or more. The blending amount of the foam stabilizer can be appropriately determined according to the desired foam characteristics, the type of foam stabilizer to be used, and the like. The ratio is about 1 to 10 parts by mass.

  In addition, when the above foaming agent is used as a foaming agent source, the foaming due to the soap function of the foaming agent (high foaming property) And foam stability), and is particularly useful when the foamable composition for polyurethane foam according to the present invention is foamed and cured by the blowing method (spray foaming method). Such foaming agents include fatty acid alkali metal salts known as soap components, particularly lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid and the like having 12 to 18 carbon atoms. Examples thereof include sodium salts or potassium salts of fatty acids. Among these, in the water foaming method, a fatty acid potassium salt is particularly preferably used.

  Further, as the flame retardant, phosphate esters such as trischloroethyl phosphate, trischloropropyl phosphate, triethyl phosphate, which have a low environmental impact and also function as a viscosity reducer for the foamable composition are advantageously used. It is done. When this phosphoric acid ester is blended, the blending amount can be appropriately determined according to the desired foam characteristics, the type of flame retardant, etc., but preferably 10 to 100 parts by weight of the phenol resin polyol. It is selected in the range of 60 parts by mass, and in the range, about 10 to 40 parts by mass is particularly preferable. Moreover, aluminum hydroxide etc. can be used suitably as a flame retardant other than the said phosphate ester.

  By the way, in the foamable composition for polyurethane foam according to the present invention, as described above, carbon dioxide generated using water is employed as a foaming agent from the viewpoint of preservation of the ozone layer. As long as carbon is used as the main blowing agent, hydrogen peroxide, pentafluoropropane (HFC-245fa), pentafluorobutane (HFC-365mfc), tetrafluoroethane (HFC-134a), etc. Foaming aid for assisting the foaming action of carbon dioxide with representative hydrofluorocarbons, low boiling point aliphatic hydrocarbons such as pentane and cyclopentane, and halogenated hydrocarbons such as dichloromethane and isopropyl chloride. It can also be added as an agent.

  And, when producing a foamable composition for polyurethane foam according to the present invention using a polyol component containing a phenol resin-based polyol as described above, a catalyst using a combination of bis (dimethylaminoethyl) ether and diethylenetriamine, etc., The same production method as that of the foamable composition for polyurethane foam can be adopted.

  For example, in order to form a target polyurethane foam by the water foaming method, that is, using carbon dioxide generated by the reaction of water and polyisocyanate as a foaming agent, first, the phenol resin-based polyol as a polyol compound or Along with it, aromatic diamine-based polyol and the like, water as a blowing agent source, a catalyst comprising bis (dimethylaminoethyl) ether and diethylenetriamine, and if necessary, a resinification catalyst, a foam stabilizer, a flame retardant, a foaming agent, Various other auxiliaries are blended to prepare a polyol blend liquid (premix liquid) as a polyol component. Subsequently, the prepared polyol compounded liquid and a polyisocyanate component containing a predetermined polyisocyanate compound are mixed at high speed using a low-pressure high-speed stirring mixer, or a high-pressure collision mixer (for example, on-site spray). A foamable composition for a liquid polyurethane foam can be produced by high-pressure collision mixing using a foaming machine. In the present invention, since the above-mentioned phenol resin polyol having a low viscosity suitable for the water foaming method is used, mixing with the polyisocyanate component is advantageously realized, and a homogeneous foamable composition is obtained. It can be manufactured.

  And the foamable composition for polyurethane foam produced in this way requires, for example, a laminated continuous foaming method in which it is applied on a face material and foamed and cured in a plate shape, and a heat insulating performance such as an electric refrigerator. Foaming is achieved by the injection foaming method in which foam is filled and foamed and cured by injecting into the honeycomb structure of the space and lightweight / high-strength board, and by the spray foaming method in which foam is sprayed and cured from the spray gun head of the on-site foaming machine. It will be cured to form the desired polyurethane foam.

Thus, in the polyurethane according to the present invention obtained using the foamable composition for polyurethane foam, the above-mentioned phenol resin-based polyol or the like is used as a polyol compound as a constituent component of the polyol component. Since a catalyst using a combination of bis (dimethylaminoethyl) ether and diethylenetriamine is used, extremely good heat insulation performance is realized despite using carbon dioxide generated by water as a blowing agent. As a result, the value of such polyurethane foam can be advantageously increased. However, if the thermal conductivity of such polyurethane foam increases, the foam thickness must be increased to ensure the same heat insulation performance. This will greatly contribute to the cost reduction. Further, the polyurethane foam produced according to the present invention generally has a density of about 20 to 100 kg / m ³ .

  Furthermore, since the polyurethane foam according to the present invention is mainly composed of a phenol resin polyol, not a polyether polyol, as a polyol compound, flame retardancy and heat resistance are also imparted. In this respect, this feature is also exhibited.

  Some examples of the present invention will be shown below to clarify the present invention more specifically. However, the present invention is not limited by the description of such examples. Needless to say. In addition to the following examples, the present invention includes various changes and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention, in addition to the specific description described above. It should be understood that improvements can be made. The “%” and “part” shown below are based on mass.

  First, a novolac-type phenol resin was prepared, and a predetermined alkylene oxide was added to the obtained novolac-type phenol resin to prepare a target phenol resin-based polyol. In addition, the viscosity and hydroxyl value of the obtained phenol resin polyol were measured by the following measuring methods.

(1) The viscosity (mPa · s) was measured according to JIS K 7117-1 using a B-type viscometer.
(2) The hydroxyl value (mgKOH / g) was measured according to JIS K1557-1.

<Preparation of novolac type phenolic resin>
In a reaction vessel equipped with a stirrer, 9400 parts of phenol, 1630 parts of 92% paraformaldehyde, and 19 parts of oxalic acid as an acid catalyst were charged and then reacted at a temperature of 100 ° C. for 5 hours while mixing with stirring. . Then, the target novolak-type phenol resin was obtained by distilling water off under reduced pressure. In addition, the free phenol content of this obtained novolak-type phenol resin was 30 mass%.

<Preparation of phenol resin polyol>
In a pressure-resistant reaction vessel equipped with a stirrer, 4000 parts of the above-mentioned novolak type phenol resin was charged together with 200 parts of potassium hydroxide as an alkali catalyst, and the mixture was stirred and mixed at 150 ° C. under pressure. At temperature, 3400 parts of ethylene oxide was added and added to the novolac phenolic resin. Thereafter, potassium hydroxide (catalyst) was neutralized with acetic acid to obtain a target phenol resin polyol. With respect to the obtained phenol resin-based polyol, the hydroxyl value and the viscosity at 25 ° C. were measured and found to be 300 mgKOH / g and 2500 Pa · s / 25 ° C., respectively.

(Examples 1-5 and Comparative Examples 1-3)
First, as the polyol compound, the phenol resin-based polyol prepared above is used, and a commercially available tolylenediamine-based polyol (trade name: Sannix HM-551, manufactured by Sanyo Chemical Industries, Ltd., hydroxyl value: 400 mgKOH / g) And bis (dimethylaminoethyl) ether (catalyst A), diethylenetriamine (catalyst B), N, N-dimethylaminoethoxyethanol (catalyst C) as a catalyst, and a resinification catalyst (trade name: Kalyzer No. 31 (33% triethylenediamine + 67% dipropylene glycol) , manufactured by Kao Corporation), and as a foam stabilizer, a silicone foam stabilizer (trade name: SH-193, manufactured by Toray Dow Corning) In addition, flame retardant (trischloropropyl phosphate), organic Each component is mixed in the compounding ratio shown in Table 1 below using an elemental compound (trade name: SH-200 0.6 cst, manufactured by Toray Dow Corning), a foaming agent (potassium ricinoleate) and water. At various times, various polyol blending solutions were prepared.

  Subsequently, using each of the obtained polyol compounded liquid and crude MDI (trade name: Lupranate M-11S, manufactured by BASF INOAC Polyurethane Co., Ltd.) as a polyisocyanate component, the temperature was increased to 10 ° C. according to the hand foaming method. After adjustment, the sample is weighed in a paper cup (capacity: 500 mL) so that the volume ratio becomes polyol compound / polyisocyanate compound = 100/100, and then high speed with a homodisper (trade name: manufactured by Primix Co., Ltd.) A polyurethane foam was prepared by stirring and mixing, and foaming and curing. And the cream time (CT) and the gel time (GT) which are the reactivity of the foamable composition in that case were measured. Further, the density of the obtained polyurethane foam was measured.

  Here, C.I. T is the time from the start of mixing of the polyisocyanate and the polyol composition to the start of foaming. T indicates the time from the start of mixing of the above components until the foam surface exhibits sticky adhesive properties.

  The results of the reactive foaming and the density measurement results are shown in Table 2 below. In the experiment of Comparative Example 3, there is a foam failure due to hardening before foaming, and the intended foam can be obtained. I could not do it.

  In addition, each of the polyol blend liquids obtained above and the above-mentioned crude MDI were used for foaming and curing by the machine foaming method, respectively. That is, using an on-site spray foaming machine (trade name: FF-1600, manufactured by Gasmer), these polyol compounded liquid and crude MDI are mixed and stirred at a volume ratio of 1: 1 to obtain a foaming stock solution. Temperature: Under the conditions of −5 ° C., −10 ° C. or −15 ° C., spraying on the surface of the concrete plate as the adherend, foaming and curing, to Examples 1-5 and Comparative Examples 1-2 Various hard polyurethane foams were produced. In addition, in the preparation example of the polyurethane foam using the polyol compounded liquid of Comparative Example 3, since it hardened before foaming, foaming was poor and the intended polyurethane foam could not be obtained.

  Then, using the various polyurethane foams thus obtained, the thermal conductivity and dimensional stability were measured, and the obtained results were evaluated as foaming and adhesive evaluation results at the time of manufacturing each polyurethane foam. The results are shown in Table 2 below.

  In this characteristic evaluation, the “density” was measured according to JIS K 7222 as an apparent overall density. In addition, regarding “foamability in an atmosphere of −15 ° C.”, when the foam is blown onto the surface of a concrete plate as an adherend in an atmosphere of −15 ° C., the blowing is performed. Evaluation was made with a foaming property having no problem as ◯, a case where foaming was slow and difficult to construct as △, and a case where dripping occurred and construction was impossible as x.

  In addition, “adhesion under −5 ° C. atmosphere”, “adhesion under −10 ° C. atmosphere”, and “adhesion under −15 ° C. atmosphere” related to evaluation of foam adhesiveness (peelability) At each temperature, after 3 minutes from the spraying of the foaming concentrate, the foam ends protruding from the concrete plate are cut along the concrete plate with a cutter knife, and the vicinity of the bonding surface between the concrete plate and the foam is cut. The presence or absence of peeling of the foam was confirmed by visual observation. In addition, ○ in the evaluation results indicates that the peeling of the foam from the concrete plate is not recognized and there is no problem with the adhesiveness, and × indicates that the foam is peeled off from the concrete plate and is difficult to adhere to. It means that there is.

  Furthermore, the measurement of “thermal conductivity (W / m · K)” is performed on the obtained polyurethane foam by using JIS A 1412-2 using a thermal conductivity measuring device (manufactured by MADDERLAKE SCIENTIFIC GROUP COMPANY, Anacon TCA POINT2). A6. Of plate comparison method in Appendix A (normative). The measurement was performed according to the measurement method. In addition, “dimensional stability” is obtained by cutting the obtained polyurethane foam into a shape of 150 mm × 150 mm × 30 mm, leaving it in an atmosphere of 50 ° C. for 24 hours, and measuring the change in thickness. [= (Size after cutting-size after standing) × 100 / size after cutting] was determined and evaluated. In the evaluation results, a case where the dimensional change rate was less than 1% was evaluated as ◯, a case where the dimensional change rate was 1% to 3%, and a case where the dimensional change rate exceeded 3% was evaluated as ×.

  As is clear from the results of Tables 1 and 2, in the foaming operations in Examples 1 to 5 according to the present invention, C.I. T and G. It is recognized that T can be improved together and foamability and adhesiveness can be improved, and all of the polyurethane foams obtained in Examples 1 to 5 use water as a foaming agent source. In other words, in spite of using carbon dioxide as a foaming agent, it has excellent thermal conductivity and dimensional stability, and in terms of foamability and adhesiveness at low temperatures. Was also very good. In particular, when a phenol resin-based polyol and an aromatic diamine-based polyol are used in combination as a polyol compound (Example 4), or when an organosilicon compound is further contained (Example 5), the improvement effect is extremely high. I can admit that it is remarkable.

  In contrast, in the foaming operations of Comparative Examples 1 and 2, C.I. T or G. It was recognized that T was not sufficient, and in the case of Comparative Example 1 using conventional N, N-dimethylaminoethoxyethanol as a catalyst, the adhesiveness under an atmosphere of −5 ° C. is Although it was satisfied for the time being, the adhesiveness and foamability at a lower temperature were worse, the thermal conductivity was not sufficient, and the dimensional stability was inferior. In addition, even when only bis (dimethylaminoethyl) ether is used as a catalyst, in addition to poor adhesion at −10 ° C. and −15 ° C. and poor dimensional stability. It can be seen that the thermal conductivity is not sufficient. Furthermore, in the case of Comparative Example 3 in which only diethylenetriamine is used as a catalyst, foaming is poor and the intended polyurethane foam cannot be obtained.

Claims (6)

A foamable composition used for producing a polyurethane foam obtained by reacting a polyol component containing a polyol compound and a catalyst with a polyisocyanate component and foaming with a water,
A polyurethane characterized in that the polyol compound contains a phenol resin polyol obtained by adding an alkylene oxide to a novolak type phenol resin, and further contains bis (dimethylaminoethyl) ether and diethylenetriamine as the catalyst. Foam composition for foam.   The foamable composition for polyurethane foam according to claim 1, wherein a content ratio of the bis (dimethylaminoethyl) ether and the diethylenetriamine is 85/15 to 15/85 on a mass basis.   The foamable composition for polyurethane foam according to claim 1 or 2, wherein the alkylene oxide added to the novolac type phenol resin is ethylene oxide or propylene oxide or both of them.   The foamable composition for polyurethane foam according to any one of claims 1 to 3, further comprising an aromatic diamine-based polyol obtained by adding an alkylene oxide to an aromatic diamine as the polyol compound.   The foamable composition for polyurethane foam according to any one of claims 1 to 4, wherein the polyol component further contains an organosilicon compound. A polyurethane foam obtained by foaming and curing the foamable composition for polyurethane foam according to any one of claims 1 to 5.