JP4531539B2 - Raw material composition for rigid polyurethane foam and method for producing rigid polyurethane foam - Google Patents

Description

  The present invention relates to a raw material composition for a rigid polyurethane foam and a method for producing the rigid polyurethane foam, and in particular, by reacting and foaming a polyol component and a polyisocyanate component in the presence of a predetermined foaming agent, the rigid polyurethane foam is obtained. The present invention relates to an advantageous manufacturing technique.

  Conventionally, a rigid polyurethane foam has been produced by making a foam structure by a foaming action by an appropriate foaming agent while a urethanization reaction proceeds between a polyol component and a polyisocyanate component. For the purpose of improving the flame retardancy and heat resistance of foams, etc., a phenol resin synthesized from phenol and aldehyde is used as one of the polyol components and reacted with a polyisocyanate component to produce a phenol-modified polyurethane. It is known to be a form. The use of such a phenolic resin is because an isocyanate group and an OH group in the phenolic resin can react to form a urethane bond. In that case, the phenolic hydroxyl group in the phenolic resin A methylol group will participate in such a reaction.

  And in Unexamined-Japanese-Patent No. 11-228664 (patent document 1), the novolak-type phenol resin whose average molecular weight is 250-1000 using the phenol monomer component whose at least 50 weight% is cresol as a polyol component, or it is used. By producing a phenol-modified polyurethane foam using a polyol containing 40% by weight or more, the conventional polyurethane foaming machine can be used as it is or with slight modifications, and its flame retardancy is remarkably increased. Although it has been clarified that it can be improved, the novolac type phenol resin used therein has a problem that it is difficult to handle because it is solid.

  Further, in this type of phenol-modified polyurethane foam, unlike the case of using ordinary polyols, it is generally difficult to control the reaction (urethanization) between the phenol resin and the polyisocyanate component, For this reason, cracks (cell cracks) are generated inside the foam to be generated, scorch (burning) is caused, and in addition to deterioration of the filling property to the mold, after demolding The problem is that the foam (molded product) is deformed. Above all, the benzylic ether type phenolic resin that has been used conventionally has a methylol group, and furthermore, a metal catalyst is also used at the time of resin production, so the reaction control at the time of polyurethane foam production is remarkable. It has become difficult.

JP-A-11-228664

  Here, the present invention has been made in the background of such circumstances, the problem to be solved is to produce a rigid polyurethane foam using a phenol resin as at least one of the polyol components. It is to facilitate control of the urethanization reaction, improve moldability, effectively suppress or prevent generation of defects in the formed foam, and improve foam characteristics.

  In order to solve such a problem, the present invention provides a rigid polyurethane foam used for the production of a rigid polyurethane foam obtained by reacting and foaming a polyol component and a polyisocyanate component in the presence of a foaming agent. A raw material composition for use in the invention, wherein at least one of the polyol components contains a phenol resin, and an aromatic compound having at least two hydroxyl groups at adjacent positions of the aromatic ring is further blended. The gist of the raw material composition for rigid polyurethane foam is as follows.

  According to one of the desirable embodiments of the raw material composition for rigid polyurethane foam according to the present invention, pyrogallol or a derivative thereof is suitably used as the aromatic compound.

  According to another preferred embodiment of the present invention, the phenol resin is desirably an ortho-cresol-modified benzyl ether type phenol resin.

  Furthermore, in another preferable embodiment of the raw material composition for rigid polyurethane foam according to the present invention, a fluorine-based surfactant is further contained.

  And in the present invention, in order to solve the above-mentioned problem, in the presence of a foaming agent, a polyol component and a polyisocyanate component are reacted and foamed to produce a rigid polyurethane foam. A rigid polyurethane foam characterized in that a phenol resin is used as at least one of the polyol components, and an aromatic compound having at least two hydroxyl groups at positions adjacent to an aromatic ring is further present in the reaction system. This manufacturing method is also the gist thereof.

  According to such a raw material composition for rigid polyurethane foam and a method for producing a rigid polyurethane foam according to the present invention, a phenol resin is used as at least one of the polyol components, and this is reacted with the polyisocyanate component, and further foamed. At the time of aging, an aromatic compound having at least two hydroxyl groups at adjacent positions of the aromatic ring is blended in the raw material composition and is present in the reaction system, thereby controlling the reaction at the time of polyurethane foam formation. As a result, the mold filling property can be effectively enhanced, the moldability can be improved, and the occurrence of cracks inside the foam can be advantageously suppressed or prevented. Furthermore, the improvement of scorch and deformation after demolding can be effectively achieved. That.

  Further, according to a desirable embodiment of the present invention, by using an ortho-cresol-modified benzyl ether type phenol resin as a phenol resin, in addition to the effect of the present invention described above can be further improved, compatibility with the polyisocyanate component The characteristic that it can also be improved will be exhibited.

  Furthermore, according to another preferred embodiment of the present invention, a fluorosurfactant is further contained, so that in the raw material composition for rigid polyurethane foam according to the present invention, a polyol component (phenol resin) and The compatibility with the polyisocyanate component can be further improved, and the effect that the mold filling property can be further improved can be additionally exhibited.

  By the way, in the present invention as described above, at least a phenol resin is used as a polyol component which is one of raw materials used for producing a target rigid polyurethane foam. And as for such a phenol resin, all the conventionally well-known various phenol resins can be made into the object. Specifically, in the presence of a reaction catalyst, phenols and aldehydes are generally in a ratio of 0.5 to 3.0 moles with respect to 1 mole of phenols, Examples of the organic solvent-soluble benzyl ether type phenol resin, resol type phenol resin, novolac type phenol resin, and modified phenol resins thereof obtained by addition / condensation reaction, and mixtures thereof can be exemplified. Of these, one or more of them are appropriately selected and used. Among these, in particular, benzyl ether type phenol resins, more preferably benzyl ether type phenol resins modified with orthocresol, and mixtures thereof are excellent in compatibility with the polyisocyanate component, and the present invention. In the present invention, it is preferably used because it is possible to further enhance the function and effect of the above.

  In addition, as a catalyst employ | adopted for the above addition and condensation reaction of phenols and aldehydes, it is not specifically limited, According to the type of desired phenol resin, an acidic catalyst, a basic catalyst, etc. Various catalysts conventionally used for the production of phenol resins are appropriately used. Among them, when producing a benzyl ether type phenol resin, for example, at least one of metal salts having metal elements such as tin, lead, zinc, cobalt, manganese, nickel, etc. is suitably employed as a reaction catalyst. To get. More specifically, such metal salts include, for example, lead naphthenate, zinc naphthenate, lead acetate, zinc chloride, zinc acetate, zinc borate, lead oxide, and such metal salts. The combination of the obtained acid and base can be mentioned. Moreover, when employ | adopting such a metal salt as a reaction catalyst, the usage-amount is although it does not specifically limit, Generally, it will be 0.01-5 weight part with respect to 100 weight part of phenols. It will be used at a rate.

  Examples of the phenols that give the phenol resin include alkylphenols such as phenol, cresol, xylenol, p-tert-butylphenol, and nonylphenol, polyhydric phenols such as resorcinol, bisphenol F, and bisphenol A, and mixtures thereof. On the other hand, examples of aldehydes include formaldehyde, formalin, paraformaldehyde, polyoxymethylene, glyoxal, furfural, and mixtures thereof.

  Further, as described above, orthocresol-modified phenol resin, which is one of the phenol resins that can be employed in the present invention, is, for example, ortho-cresol and / or phenol in the presence of a reaction catalyst such as a metal salt. (1) Co-condensation type ortho cresol modified phenol resin of ortho cresol and phenol obtained by reaction with aldehydes, (2) Mixed type ortho cresol modified phenol resin of ortho cresol resin and phenol resin, 1) and (2) resins modified with a modifier (modifier), (3) modified orthocresol modified phenolic resin, and 2 of (1), (2) and (3) The mixture etc. which combined the seed | species or more can be illustrated.

  The (1) co-condensation type ortho-cresol-modified phenol resin is a co-condensation resin obtained by reacting ortho-cresol and phenol with aldehydes simultaneously or stepwise, and the reaction catalyst used Depending on the reaction conditions such as the type, a novolak type, a resol type, a benzyl ether type, and a co-condensation type orthocresol-modified phenol resin combining these types can be obtained. In the present invention, as described above, benzyl ether A co-condensation type ortho-cresol-modified phenol resin is preferably used. Moreover, as a compounding ratio of orthocresol and phenol, generally, orthocresol / phenol (weight ratio) = about 10/90 to 90/10, preferably about 30/70 to 70/30 is employed.

  The mixed orthocresol-modified phenol resin (2) described above is at least one selected from the group of novolak-type, resol-type and benzylether-type orthocresol resins obtained by reacting orthocresol and aldehydes. Obtained by mixing a kind of ortho-cresol resin and at least one phenol resin selected from the group of novolak-type, resol-type and benzyl ether-type phenol resins obtained by reacting phenol with aldehydes It is a mixed type ortho-cresol modified phenol resin. Among these, in the present invention, a benzyl ether type mixed ortho cresol-modified phenol resin obtained by mixing a benzyl ether type ortho cresol resin and a benzyl ether type phenol resin is preferably used. In addition, even in such a mixed type ortho-cresol-modified phenol resin, the ortho-cresol resin and the phenol resin are preferably ortho-cresol resin / phenol so that the blending ratio of ortho-cresol and phenol is in the above-described range. Phenol resin (weight ratio) = 10 / 90-90 / 10, More preferably, it will mix in the ratio of 30 / 70-70 / 30.

  In addition, the modified orthocresol-modified phenolic resin (3) described above may be any modifier (modifier), for example, during or after the production of the co-condensation resin, orthocresol resin or phenol resin. Alkyd resin, epoxy resin, melamine resin, urea resin, xylene resin, vinyl acetate resin, polyamide resin, urea compound, melamine compound, epoxy compound, furfuryl alcohol, polyvinyl alcohol, urea, amides, linseed oil, cashew nut At least one modified orthocresol selected from the group of novolak type, resol type and benzyl ether type resins modified by mixing or reacting with shell liquid, rosin, starches, monosaccharides, etc. It is a modified phenolic resin. Among these, in the present invention, a modified ortho resin-modified phenol resin of benzyl ether type is preferably used.

  In the present invention, such a phenolic resin is used so as to give the total amount of the polyol component, and in combination with various known polyol compounds conventionally used in the production of polyurethane foam. Thus, it is used as a polyol component. The blending ratio of such a polyol compound and a phenol resin is appropriately selected depending on the characteristics of the target rigid polyurethane foam. Generally, the phenol resin in the polyol component is 10% by weight. It is desirable to mix | blend so that it may become more than%, Especially preferably, it will be used in the ratio of about 30 to 90%.

  Here, examples of other polyol compounds used as the polyol component together with the phenol resin include various conventionally known polyol compounds such as polyether polyol, polyester polyol, ether diol, polymer polyol and the like. I can do it. More specifically, among these polyol compounds, examples of polyether polyols include polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, sorbitol, and sucrose, monoethanolamine, diethanolamine, ethylenediamine, Obtained by reacting two or more active hydrogen-containing compounds such as amines such as diethylenetriamine, aniline, phenylenediamine, xylylenediamine, tolylenediamine, etc. with an alkylene oxide (for example, ethylene oxide, propylene oxide, butylene oxide, etc.). A polyether polyol etc. can be mentioned. Examples of polyester polyols are obtained by reacting polyhydric alcohols with polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, maleic acid, phthalic acid, terephthalic acid, trimellitic acid, and dimer acid. In addition to polyester polyols, lactone polyester polyols obtained by ring-opening polymerization of lactones can be used.

  On the other hand, the polyisocyanate component which is another main raw material of the raw material composition for rigid polyurethane foam according to the present invention is not particularly limited as long as it is an organic isocyanate compound having two or more isocyanate groups in the molecule. Various conventionally known polyisocyanates are appropriately selected and used. Examples of such polyisocyanates include diphenylmethane diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate (common name: crude MDI), tolylene diisocyanate (common name: TDI), mixed TDI, xylene diisocyanate, and the like. Group-modified polyisocyanates and urethane-modified polyisocyanate prepolymers obtained by reacting these aromatic polyisocyanates and polyols. In addition, if necessary, cycloaliphatic polyisocyanates such as isophorone diisocyanate, water-added methylene diphenyl diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, modified polyisocyanates such as isocyanurate-modified, burette-modified, carbodiimide-modified polyisocyanate, etc. Can also be used.

  The amount of the polyisocyanate component as described above is appropriately set according to the type of foam (urethane type, urethane nurate type, nurate type), physical properties, usage, and the like. The equivalent ratio of the isocyanate group (NCO group) of the component to the hydroxyl group (OH group) of the polyol component (NCO group / OH group, hereinafter referred to as NCO index) is in the range of about 0.5 to 3.0, and An amount in which the volume ratio of the polyol component to the polyisocyanate component (polyisocyanate component / polyol component) is in the range of about 1.0 to 2.0 is suitably employed.

  Further, in the present invention, the polyol component containing at least a phenol resin and the polyisocyanate component, which are the main raw materials as described above, are, as before, a one-component or two-component rigid polyurethane foam raw material composition. According to the present invention, the raw material composition further includes an aromatic compound having at least two hydroxyl groups at adjacent positions of the aromatic ring (hereinafter referred to as “adjacent hydroxyl group”). Are added and blended as essential constituent components, so that the reaction control can be easily performed in the urethanization reaction between the polyol component and the polyisocyanate component. It is like that.

  Thus, by using a raw material composition in which an aromatic compound having an adjacent hydroxyl group is blended, the urethanization reaction can be easily controlled, but the mechanism has not yet been clarified sufficiently. Although it is not, it is guessed as follows. That is, according to the inferences of the present inventors, the phenol resin and the polyisocyanate component are derived from the metal component derived from the reaction catalyst used when the phenol resin is produced and the metal component brought in from other additives and equipment. However, by adding an aromatic compound having an adjacent hydroxyl group, the oxygen atom of the adjacent hydroxyl group of the aromatic compound causes an electrical interaction with the metal component. Then, the metal is trapped, and more specifically, two oxygen atoms of adjacent hydroxyl groups of the aromatic compound are coordinated to the metal ion to form a stable 5-membered chelate ring, It is thought that this is because the promotion of the urethanization reaction by the metal component is effectively suppressed.

  In addition, as the aromatic compound having such an adjacent hydroxyl group, an aromatic compound having at least two hydroxyl groups in a form in which hydroxyl groups are bonded to adjacent positions in an aromatic ring such as a benzene ring or a naphthalene ring. Any of those having an acidic group such as a carboxyl group in addition to such a hydroxyl group consumes a ventilated curing catalyst (urethanization catalyst) gas, and Its use should be avoided because it can interfere with catalysis. Specifically, examples of the aromatic compound having an adjacent hydroxyl group that is advantageously used in the present invention include catechol, 4-methylcatechol, 4-ethylcatechol, 4-t-butylcatechol, pyrogallol, 1,2,4. -Trihydroxybenzene, methyl gallate, ethyl gallate, methyl protocatechuate, ethyl protocatechuate, 1,2-naphthalenediol, 2,3-naphthalenediol, etc., and derivatives thereof such as 2- (4-hydroxy Phenyl) -2- (2,3,4-trihydroxyphenyl) propane, 2,6-bis (2,3,4-trihydroxybenzyl) -4-methylphenol, bis (4,5-dihydroxy-2-phenyl) Methylphenol) phenylmethane and the like. Moreover, the aromatic compound which has these adjacent hydroxyl groups may be used independently, and may be used in combination of 2 or more type. Among these, catechol, pyrogallol, and derivatives thereof such as 2- (4-hydroxyphenyl) -2- (2,3,4-trihydroxyphenyl) propane, 2,6-bis (2,3, 4-Trihydroxybenzyl) -4-methylphenol, bis (4,5-dihydroxy-2-methylphenol) phenylmethane, and the like are more preferably used in the present invention.

  The amount of the aromatic compound having an adjacent hydroxyl group is not generally limited, and can be appropriately set according to the type of the aromatic compound used, the amount of metal present in the reaction system, and the like. However, it is generally desirable that the amount is set in the range of 0.01 to 100 parts by weight, preferably 0.1 to 10 parts by weight, with respect to 100 parts by weight of the phenol resin.

  In the present invention, conventionally known various foaming agents are appropriately selected and used in order to foam the polyurethane formed by reacting the above-described polyol component and polyisocyanate component. . And as a foaming agent for forming such a foam, dichlorofluoroethane (alternative chlorofluorocarbon HCFC-141b), dichloropentafluoropropane (alternative chlorofluorocarbon HCFC-225), 1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,3,3-pentafluorobutane (HFC-365mfc), trifluoroethane, tetrafluoroethane, pentafluoropropane, Halogenated hydrocarbons such as perfluorohexane, perfluoropentane, and methylene chloride; aliphatic hydrocarbons such as pentane and hexane; and reactive foaming agents that utilize the reaction of polyisocyanate with hydrogen peroxide and water; Decomposable foaming agents such as carbon dioxide adducts and combinations thereof As necessary, aliphatic ethers such as diethyl ether and diisopropyl ether, thermal decomposition blowing agents such as paratoluenesulfonyl hydrazide, oxybisbenzenesulfonyl hydrazide, azobisisobutyronitrile, air, nitrogen Gas bodies such as carbon dioxide and butane are also used. The amount of foaming agent used varies depending on the foam density, the type of foaming agent, etc., but is generally selected in the range of 0.1 to 50 parts by weight per 100 parts by weight of polyol.

  Furthermore, a fluorosurfactant is advantageously added and blended in the raw material composition for rigid polyurethane foam according to the present invention. In addition to further improving the compatibility between the polyol component and the polyisocyanate component, the filling property or moldability of the mold can be advantageously improved by blending this fluorosurfactant. It is.

  The fluorosurfactant used here is a part of or all of the fluorine atom (H) bonded to the carbon atom (C) of the hydrophobic group of a normal surfactant instead of the hydrogen atom (H). The one substituted with F). This fluorosurfactant includes anionic, cationic, nonionic, and the like. As anionic, perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl phosphate, and the like are cationic. As perfluoroalkyltrimethylammonium salts, and the nonionic examples are perfluoroalkylethylene oxide adducts, perfluoroalkyl group-containing oligomers, etc., each of which may be used alone or in combination of two or more. In addition, it can be used in combination with a surfactant other than fluorine.

  Such a fluorosurfactant is generally preferably 0.05 to 5 parts by weight with respect to 100 parts by weight of the polyol component, in order to effectively exert the addition effect. It will be used at a ratio of ˜1 part by weight. If the amount added is too large, bubbles may break during the reaction process, making it difficult to form the foam, or causing a decrease in physical properties such as the foam becoming brittle.

  Furthermore, in the production of the desired rigid polyurethane foam, in addition to the above-mentioned polyol component, polyisocyanate component, foaming agent and advantageously added fluorosurfactant, a catalyst, A foam stabilizer or the like is appropriately used.

  Here, as the above-described catalyst, for example, tertiary amine, dibutyltin dilaurate, ethylmorpholine, triethylenediamine, tetramethylhexamethylenediamine, hydroxyalkyl quaternary ammonium salt, lead naphthenate, potassium octylate, sodium acetate, A curing catalyst such as hexahydrotriazine, a silane coupling agent such as γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, resorcin, etc. can be mentioned, and at least one of these, It is appropriately selected and used. Moreover, even if it exists in the usage-amount of a catalyst, the usage-amount similar to the past is employ | adopted and generally the ratio used as 0.1-15 weight part is employ | adopted with respect to 100 weight part of a polyol component.

  In addition, as the foam stabilizer, a nonionic surfactant is preferably employed. However, in some cases, other surfactants such as anionic surfactants are used alone or non-ionic. It can also be used in combination with an ionic surfactant. Specific examples of such nonionic surfactants include polysiloxane oxyalkylene copolymers, polyoxyethylene sorbitan fatty acid esters, castor oil ethylene oxide adducts, alkylphenol ethylene oxide adducts, lauryl fatty acid ethylene oxide adducts, lauryl alcohol ethylene oxide. Additives and mixtures thereof can be exemplified. Moreover, the usage-amount of this foam stabilizer is normally set suitably in the range used as about 0.3-10 weight part with respect to 100 weight part of a polyol component.

  In addition, in the present invention, if necessary, formaldehyde scavengers such as urea and melamine; bubble refining agents such as trimethylmethoxysilane; melamine compounds, phosphorus compounds, halogen compounds, red phosphorus, Flame retardants such as aluminum hydroxide; plasticizers (viscosity modifiers); antioxidants; antifungal agents; colorants; fillers; various additives such as reinforcing substrates that are likely to give rise to the desired foam structure Therefore, it can be selected and used as appropriate.

  By the way, the raw material composition for rigid polyurethane foam according to the present invention is a polyol composition in which a foaming agent, a catalyst, a foam stabilizer, and other various additives used as necessary are blended with the polyol component as described above. (Premix liquid) is a one-pack type or two-pack type composition in which a polyisocyanate component is further combined, and these various raw material components are mixed using a known stirrer such as a high-pressure collision mixer. By stirring and mixing, it is used as a liquid foamable composition to form a desired rigid polyurethane foam.

  Thus, according to the present invention, although at least a phenol resin is used as the polyol component, the raw material composition contains an aromatic compound having an adjacent hydroxyl group and is present in the reaction system. Thus, the urethanization reaction between the polyol component and the polyisocyanate component can be easily controlled, and the moldability and the characteristics of the obtained rigid polyurethane foam can be remarkably improved.

  Hereinafter, the present invention will be more specifically clarified by using some examples, but the present invention is not construed as being limited in any way by the description of such examples. It should be understood.

-Phenolic resin production example 1-
A reaction vessel equipped with a thermometer, stirrer and reflux condenser was charged with 2300 parts of phenol (weight basis, the same applies hereinafter), 960 parts of 92% paraformaldehyde, 2.5 parts of lead naphthenate, and 1.2 parts of lead oxide. The mixture was heated to a temperature of 100 ° C. and reacted at the same temperature for 1.5 hours, further heated to 115 ° C., reacted at the same temperature for 1 hour, and then cooled to 40 ° C. Subsequently, while stirring, the pressure in the reaction system was reduced to about 20 to 60 mmHg, and the mixture was heated to 115 ° C. and concentrated to produce benzyl ether type phenol resin A. The obtained benzyl ether type phenol resin A had a water content of 0.2% by weight as measured by the Karl Fischer method, and had a viscosity of 7000 mPa · s / 25 ° C. .

-Phenol resin production example 2-
A reaction vessel equipped with a thermometer, a stirrer and a reflux condenser was charged with 1000 parts of o-cresol and 780 parts of 92% paraformaldehyde, 2.8 parts of lead naphthenate, and 1.3 parts of lead oxide, and a temperature of 100 ° C. The mixture was heated to 30 ° C., reacted at the same temperature for 1 hour, and then cooled to a temperature of 30 ° C. Subsequently, 1000 parts of phenol was added to the obtained reaction product and reacted at a temperature of 100 ° C. for 1.5 hours, then the temperature was raised to 115 ° C. and reacted at the same temperature for 1 hour. Cooled to a temperature of ° C. Then, while stirring, the pressure inside the reaction system was reduced to about 20 to 60 mmHg, and heated to 115 ° C. and concentrated to produce ortho-cresol-modified benzyl ether type phenol resin B. And, as a result of measuring the water content of the obtained ortho-cresol-modified benzyl ether type phenol resin B by the Karl Fischer method, it was 0.2% by weight, and its viscosity was 7000 mPa · s / 25. ° C.

Examples 1 to 4 and Comparative Example 1
70 parts of any of the two types of benzyl ether type phenol resins obtained above (phenol resins A and B), 0.05 parts of pyrogallol, and amine-based polyether polyols as other polyol compounds ( 30 parts of Asahi Glass Co., Ltd., trade name: EXCENOL 480A), 1 part of silicone-based nonionic surfactant as a foam stabilizer, Tris (chloro profile) phosphate (manufactured by Akzo Nobel Co., Ltd.) as a viscosity modifier In addition, in Examples 3 and 4, using 10 parts of a trade name: Pyrol PCF) and 4 parts of a hydrofluorocarbon (manufactured by Daikin Industries, Ltd., trade name: AE-51) as a blowing agent. 0.2 part of a fluorosurfactant (manufactured by Seimi Chemical Co., Ltd., trade name: Surflon S-141) was used, and A foaming catalyst (manufactured by Tosoh Corporation, trade name: TOYOCAT-DT) and a urethanization catalyst (manufactured by Sankyo Air Products, trade name: DABCO-33LV) are mixed so that the gel time is 50 seconds. Various premix liquids (polyol component) were prepared.

  On the other hand, crude MDI (manufactured by Mitsui Takeda Chemical Co., Ltd., trade name: Cosmonate M200, NCO content = 30.5% by weight) adjusted to 25 ° C. was prepared as a polyisocyanate component.

  Next, using the prepared premix solution (polyol component) and the polyisocyanate component, 55.0 parts of the former and 57.5 parts of the latter are weighed into a polyethylene cup (capacity: 500 cc), and then After mixing with high speed stirring with homodisper (trade name, manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a raw material composition for rigid polyurethane foam, it is injected into various molds for the following properties measurement. Then, rigid polyurethane foams were produced by foaming and curing. The foaming behavior and foam physical properties at that time were evaluated as follows, and the results are shown in Table 1 below. In addition, mixing of the polyisocyanate component and the polyol component was performed at a ratio where the NCO index was 1.10.

  For comparison, without addition of pyrogallol, a premix liquid (polyol component) prepared at the same blending ratio as in Example 1 was used, and this and the polyisocyanate component were By reacting in the same manner, a rigid polyurethane foam was produced, and the foaming behavior and foam characteristics at that time were evaluated in the same manner as described above.

  In forming the foam, first, in order to determine the reactivity of the raw material composition, cream time, gel time, and rise time showing foaming behavior were measured. The cream time is the time from the start of mixing the polyol component (premix liquid) and the polyisocyanate component to the start of foaming, and the gel time is the adhesiveness that allows the surface of the foam to be stringed from the start of mixing the two components. The rise time indicates the time from the start of mixing the two components to the end of foaming.

  Regarding foam physical properties, the presence or absence of internal cracks, the presence or absence of scorch (burning), the filling properties in the mold, the presence or absence of deformation after demolding, and the compatibility of the two components are as follows. The results are shown in Table 1 below.

-Internal crack and scorch evaluation-
A foam produced by foaming and curing the raw material composition obtained above by free foaming in a cup is allowed to stand for 24 hours at an ambient temperature of 25 ° C., and then the foam is cut in the longitudinal direction. Then, the presence or absence of internal cracks was visually confirmed, and evaluation was made by assuming that there were many cracks as x, small cracks as Δ, and no cracks as ○.

  Also, for scorch (burn), about the cup-shaped foam obtained by free foaming, cut it in half and visually check for the presence of scorch inside, scorch with ×, scorch Evaluation was made with none as a circle.

-Evaluation of moldability (moldability)-
A polyurethane foam panel was manufactured by injecting a specified amount of the prepared raw material composition into a central portion of a 150 mm × 150 mm × 50 mm mold that had been temperature-controlled in advance at 60 ° C., and curing the foamed composition. After that, the panel is taken out from the mold, and the state of injection of the raw material composition into the mold, and by extension, the filling property of the foam is visually confirmed from the molded state of the panel. Was evaluated as △, and the one filled in the end portion as ◯.

-Deformation evaluation after demolding-
The polyurethane foam panel obtained by the above-mentioned foam curing is taken out from the mold, and a 300 mm length ruler is applied to the diagonal line of the 150 mm × 150 mm surface, and the length of the gap between the panel and the ruler Was measured for the state of deformation of the foam (molded product) after demolding. The evaluation was evaluated as x when the gap was 2 mm or more, Δ when the gap was less than 2 mm, and ◯ when there was no gap.

-Compatibility evaluation of two components-
At the time of stirring and mixing the polyol component (premix liquid) and the polyisocyanate component described above, the stirring and mixing conditions are as follows: (a) liquid temperature of polyol component / liquid temperature of polyisocyanate component = 35 ° C./25° C., stirring rotation Number = 8000 rpm or (b) Polyol component liquid temperature / polyisocyanate component liquid temperature = 25 ° C./15° C., stirring rotation speed = 1500 rpm, and using a raw material composition obtained by stirring and mixing under the respective conditions Then, polyurethane foam was obtained by foaming and curing. In addition, said (b) prepared the raw material composition by making the stirring and mixing conditions worse and deliberately making the mixture of two components worse.

  And the height of each polyurethane foam obtained under the stirring and mixing conditions of (a) and (b) was measured, and the foam elongation under the stirring and mixing conditions (b) was determined as the stirring and mixing conditions of (a). The elongation percentage was obtained by dividing by the foam elongation at, and when it was less than 60%, it was evaluated as x when it was less than 60%, Δ when it was 60% or more and less than 80%, and ○ when it was 80% or more.

  As is apparent from the results of Table 1, when the raw material compositions of Examples 1 to 4 according to the present invention were used, in the foaming behavior, the time from the cream time to the gel time was long. It can be recognized that the reaction control of the chemical reaction is easy. As for foam properties, excellent results have been obtained in terms of internal cracks, scorch, mold filling, deformation after demolding, and compatibility between the polyol component and polyisocyanate component. I can admit. Moreover, those characteristics can be improved more favorably when the ortho-cresol-modified benzyl ether type phenol resin (B) is used than the benzyl ether type phenol resin (A). It can be recognized that the mold filling property and the compatibility of the two components are particularly improved.

Claims (5)

A raw material composition for a rigid polyurethane foam used for producing a rigid polyurethane foam obtained by reacting and foaming a polyol component and a polyisocyanate component in the presence of a foaming agent,
Obtained by addition / condensation reaction of phenols and aldehydes selected from the group consisting of phenol, cresol, xylenol, p-tert-butylphenol, nonylphenol, resorcinol, bisphenol F and bisphenol A as at least one of the polyol components co to include phenol resin, an aromatic compound having at least two hydroxyl groups in adjacent positions of Kaoru incense ring is further possible rigid polyurethane foam raw material composition, characterized in being formulated.   The aromatic compound is pyrogallol, 2- (4-hydroxyphenyl) -2- (2,3,4-trihydroxyphenyl) propane, or 2,6-bis (2,3,4-trihydroxybenzyl)- The raw material composition for rigid polyurethane foam according to claim 1, which is 4-methylphenol.   The phenol resin comprises (1) a co-condensation type benzyl ether type phenol resin obtained by reacting ortho cresol and phenol with an aldehyde, and (2) a benzyl ether type ortho cresol resin and a benzyl ether type phenol resin. A mixed ortho-cresol-modified phenol resin obtained by mixing, and (3) a group consisting of a modified ortho-cresol-modified phenol resin obtained by modifying the resin of (1) or (2) with a modifier. The raw composition for a rigid polyurethane foam according to claim 1 or 2, which is a selected ortho-cresol-modified benzyl ether type phenol resin.   The raw material composition for rigid polyurethane foam according to any one of claims 1 to 3, further comprising a fluorine-based surfactant. In the production of a rigid polyurethane foam by reacting and foaming a polyol component and a polyisocyanate component in the presence of a foaming agent,
Obtained by addition / condensation reaction of phenols and aldehydes selected from the group consisting of phenol, cresol, xylenol, p-tert-butylphenol, nonylphenol, resorcinol, bisphenol F and bisphenol A as at least one of the polyol components co with phenol resin, an aromatic compound having at least two hydroxyl groups in adjacent positions of Kaoru incense ring, further, the method for producing a rigid polyurethane foam, characterized in that allowed to exist in the reaction system.