JP2008266579A - Manufacturing method of molded polyurethane product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for rapidly producing a molded polyurethane article under a high reactivity by a reaction injection molding method and in the method described above even in the case that the molded polyurethane article is made to be a low density by foaming, and the molded polyurethane article in which the surface property is good and lowering of hardness is suppressed, further under suppressing the lowering of hardness, weatherability is superior, can be rapidly produced. <P>SOLUTION: Provided is a method for producing a molded polyurethane article by the reaction injection molding, wherein a polyol-containing component containing a polyether type polyol with a hydroxyl value of 15-60 mgKOH/g and a number of a functional group of 2 to 4, and a chain extender having a molecular weight of 60-200 and a number of functional groups of 2 to 4, and a polyisocyanate component containing an aromatic polyisocyanate and its modified material are reacted, under the condition where a catalyst is present and water is not substantially contained, for 10 sec or less, to form a solid phase. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a polyurethane molded article. More specifically, polyurethane that can be suitably used as a sealing material for automobiles, a sealing material for building materials, a damping material, a cushioning material, a polishing pad, etc., using a reaction injection molding method (hereinafter referred to as RIM method). The present invention relates to a method of manufacturing a high speed. Further, the present invention relates to a method for producing a foamed polyurethane molded article that can be reduced in density while ensuring necessary characteristics even when foamed using a gas in a supercritical state, and can be suitably used as the above-mentioned application.

  The RIM method is a method of obtaining a molded article by injecting and mixing high-reactive raw material components at high pressure in a mixing chamber, and injecting them into a closed mold. Therefore, when polyurethane is produced at high speed by the RIM method, it is important to control the reaction of the raw materials and ensure fluidity in the mold.

  Conventionally, in order to ensure high reactivity, a compound containing a highly reactive amino group such as polyether polyamine or diethyltolylenediamine as a polyol component is used as a polyol component, or a high amount such as an organic lead catalyst is used. An active catalyst is used. For example, in Patent Document 1, a secondary polyether polyamine compound is used for the polyol component. In Patent Document 2, the reactivity is enhanced by using an amine-terminated polyether and a polyether other than the amine terminal in the production of a prepolymer of a polyisocyanate component. Patent Document 3 uses an aliphatic or alicyclic polyamine or alkanolamine as a crosslinking agent, and a component selected from the group consisting of organic lead, organic bismuth and organic tin as a catalyst. In Patent Document 4, a compound having an amino group is used as the chain extender, and the cost reduction is achieved while increasing the reactivity by adjusting the ratio of the hydroxyl group to the amino group in the chain extender. Further, in Patent Document 5, from the viewpoint of improving productivity while reducing the environmental load, an active hydrogen-containing compound such as a terminal aminated polyether having a specific amino group equivalent is used as a raw material, and tertiary amine and dialkyl are used. It has been reported that by using a catalyst composed of an organic acid salt of tin, a good polyurethane resin can be produced substantially without using a lead catalyst.

  The RIM method is also used in the manufacturing method of foamed polyurethane. In Patent Document 6 and Patent Document 7, a supercritical gas is used as a foaming agent to reduce the size of cells and cope with complex shapes. Is going.

On the other hand, it is also important to maintain the characteristics of the polyurethane after the reaction. For example, as a technique for improving the weather resistance, a technique using a specific aliphatic polyisocyanate (see Patent Documents 3 to 5 and 8) has been reported. In addition, techniques using weathering assistants such as ultraviolet absorbers, radical scavengers, peroxide decomposers and the like are known to those skilled in the art.
JP-A-6-49170 JP-A-7-53656 JP 2001-501241 A Japanese Patent Application Laid-Open No. 7-209777 JP 2006-701118 A JP 2002-178352 A JP 2006-124579 A JP-A-8-165323

  However, since the polyether polyamine itself is very expensive, there is a problem that the cost becomes high and the product cannot be supplied at a low cost. Moreover, since aromatic amines, such as diethyltolylenediamine, are too reactive, in the methods of Patent Documents 1 and 2 using an aromatic amine compound, it is difficult to control the reaction when a general-purpose polyether polyol is used. On the other hand, since aliphatic isocyanate has low reactivity, it is necessary to use a catalyst such as an organic acid lead-based catalyst in order to enhance the reactivity. . The method of Patent Document 4 can be applied only when an aliphatic isocyanate is used and a raw material having a high number of NCO functional groups is used. According to Patent Document 5, productivity is reduced while reducing the environmental burden compared to a lead-containing catalyst. Although it can be improved, the solidification time of the obtained molded product cannot be said to be sufficiently short while using a large amount of catalyst. Further, in Patent Documents 6 and 7, there is a problem in actual production because the shortening of the solidification time is not considered.

  Moreover, although the weather resistance of polyurethane can be improved by the conventional addition technology of deterioration inhibitors and the combined use of aliphatic / alicyclic isocyanates such as Patent Document 8, the aliphatic polyisocyanate is expensive. There is a problem that the cost becomes high and the product cannot be supplied at a low cost. On the other hand, when aromatic polyisocyanate is used, although it is cheaper than aliphatic polyisocyanate, there is a problem that weather resistance such as discoloration is remarkably deteriorated.

  Furthermore, the conventional polyol component often contains a polyol in which a polyoxyethylene group is added to the molecular end, and this is because it is applied to the RIM method from the viewpoint of reactivity.

  An object of the present invention is to provide a method for rapidly producing a polyurethane molded product with high reactivity without using an expensive polyether polyamine and an organic acid lead which is an environmental load substance by a reaction injection molding method. is there. Moreover, in the said method, even when it lowers the density of a polyurethane molded product by foaming, it is also a problem that a polyurethane molded product having good surface properties and suppressing a decrease in hardness can be rapidly produced. Furthermore, even when a polyether polyol having no polyoxyethylene group is used as the polyol component, or when a specific amount of aromatic polyisocyanate is used, polyurethane having excellent weather resistance while suppressing a decrease in hardness. It is also a problem that a molded product can be manufactured quickly.

  As a result of intensive studies to solve the above problems, the present inventors have made a polyurethane molded product with high productivity by reacting a specific polyol-containing component and an isocyanate component under a specific catalyst other than an environmentally hazardous substance. Has been found to be possible, and the present invention has been completed. In addition, the present inventors have found that it is possible to produce a polyurethane molded article having excellent weather resistance even when an aromatic polyisocyanate is used as an isocyanate component, and the present invention has been completed.

That is, the present invention
[1] A method for producing a polyurethane molded product by a reaction injection molding method, which is a polyether polyol having a hydroxyl value of 15 to 60 mgKOH / g and a functional group number of 2 to 4, a molecular weight of 60 to 200, and a functional group number of 2 A polyol-containing component (1) containing a chain extender which is ˜4, a polyisocyanate component (2) containing an aromatic polyisocyanate and a modified product thereof and having an NCO content of 19 to 28% by weight, an organic acid Bismuth, organic acid tin, organic acid zinc, and diazabicycloalkene and a catalyst (3) containing one or more selected from the group consisting of the salts thereof, and substantially water The present invention relates to a method for producing a polyurethane molded product, which is reacted under a condition not containing water and solidified in 10 seconds or less, and [2] a polyurethane molded product obtained by the production method described in [1].

  By the method of the present invention, even in the reaction injection molding method, it can be produced with high reactivity without using an organic acid lead as an environmental load substance, and a polyurethane molded product having a short solidification time and excellent productivity is produced. be able to. When the density is reduced by foaming, it is possible to obtain a foamed polyurethane molded product having not only a short solidification time and excellent productivity, but also excellent surface properties and a suppressed hardness reduction. In addition, even when a polyether polyol having no polyoxyethylene group, which is said to have low reactivity, is used, a polyurethane molded product having a short solidification time and excellent productivity can be produced, and the weather resistance is poor. Even when a specific amount of the aromatic polyisocyanate said to be used is used, it is possible to obtain a foamed polyurethane molded article having excellent weather resistance in addition to the above characteristics. Furthermore, since the use of expensive raw materials is suppressed, the manufacturing cost can be reduced.

  The present invention is a method for producing a polyurethane molded article by a reaction injection molding method using a polyol-containing component (1), a polyisocyanate component (2) and a catalyst (3), wherein the polyol-containing component and the polyisocyanate component are One characteristic is that the reaction is carried out in the presence of a specific catalyst and under substantially no water. The catalyst (3) contains at least one selected from the group consisting of organic acid bismuth, organic acid tin, organic acid zinc, diazabicycloalkene and a salt thereof, and is an organic substance which is an environmental load substance. It does not contain lead acid. In the present invention, since the polyol-containing component and the polyisocyanate component are reacted in the presence of such a catalyst, the reactivity of the urethanization reaction can be increased, and the production of a polyurethane molded product by the RIM method can be carried out using lead organic acid. Can be done without using. In addition, the molded product in this specification shall mean both the polyurethane obtained by making a polyol component and a polyisocyanate component react as it is, and the polyurethane foam obtained using a foaming agent in the said reaction. In the present specification, the “conditions substantially free of water” mean conditions under which water is substantially absent, so long as the effect of the present invention is not affected. For example, a small amount of water may be mixed and mixed, and the water content is preferably 0.1 parts by weight or less with respect to 100 parts by weight of the total amount of the polyol-containing component (1) and the polyisocyanate component (2). More preferably, the amount is 0.03 parts by weight or less, and the case where such an amount of water is present is included in the “conditions substantially free of water”.

  The polyol-containing component (1) is a component that reacts with the polyisocyanate component, a polyether polyol having a hydroxyl value of 15 to 60 mg KOH / g, and having 2 to 4 functional groups, a molecular weight of 60 to 200, and 2 functional groups. Chain extender which is ~ 4.

  The polyether polyol is not particularly limited as long as it has a hydroxyl value of 15 to 60 mg KOH / g and a functional group number of 2 to 4, and examples of those that are generally used in the production of polyurethane are exemplified. The

  The hydroxyl value is desirably 15 to 60 mg KOH / g, preferably 20 to 60 mg KOH / g, more preferably 25 to 60 mg KOH / g, from the viewpoint of maintaining the properties as a polyurethane molded product. The hydroxyl value is a value measured according to JIS K1557. Also, when two or more polyether polyols are used, the polyether polyol preferably has an individual hydroxyl value of 15 to 60 mg KOH / g. Good. In that case, the hydroxyl value of the entire polyether polyol can be expressed by the weighted average hydroxyl value of the polyether polyol, and the average hydroxyl value is 15 to 60 mgKOH / g, preferably 20 to 60 mgKOH / g, more preferably 25. Desirably ˜60 mg KOH / g.

  The number of functional groups is 2 to 4, preferably 2 or 3, and when using two or more polyether polyols, the number of individual functional groups of the polyether polyol is preferably 2 to 4, Although it is more preferable that it is 2 or 3, you may use a part of thing outside the said range together. In that case, the number of functional groups of the entire polyether polyol can be expressed by the weighted average number of functional groups of the polyether polyol, and is preferably 2 to 4 and more preferably 2 or 3 as the average number of functional groups. .

  Typical examples of the polyether polyol having such a hydroxyl value and the number of functional groups include polyoxyalkylene polyol, polytetramethylene ether glycol that can be produced by ring-opening polymerization of tetrahydrofuran, and the like.

  Polyoxyalkylene-based polyols are produced by ring-opening addition reaction of alkylene oxide using a starting material such as a hydroxyl group, primary amino group, secondary amino group, or other compound having two or more functional groups having active hydrogen. can do. The two or more functional groups may be the same or different.

  Starting materials for polyoxyalkylene polyols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, etc. Polyhydric alcohol, ethanolamine, diethanolamine, triethanolamine, alkanolamines such as methyldiethanolamine, ethylenediamine, 1,3-propanediamine, 1,6-hexanediamine, isophoronediamine, 3-dimethylaminopropylamine, etc. Examples thereof include amines and modified products thereof, and these can be used alone or in admixture of two or more. Among these, dipropylene glycol, glycerin, and triethanolamine are preferable.

  Examples of the alkylene oxide that undergoes a ring-opening addition reaction when producing a polyoxyalkylene-based polyol include ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, and styrene oxide. Each can be used alone or in admixture of two or more. Among these, ethylene oxide and propylene oxide are preferable.

  Examples of suitable polyether polyols include (di) ethylene glycol polyether polyols, (di) propylene glycol polyether polyols, glycerin polyether polyols obtained by addition reaction of ethylene oxide and / or propylene oxide, Trimethylolpropane-based polyether polyol, pentaerythritol-based polyether polyol, mono (di, tri) ethanolamine-based polyether polyol, methyldiethanolamine-based polyether polyol, ethylenediamine-based polyether polyol, 3-dimethylaminopropylamine-based polyether Examples thereof include polyoxyalkylene polyols such as polyols, and these can be used alone or in admixture of two or more. Among these, (di) ethylene glycol polyether polyol, (di) propylene glycol polyether polyol, glycerin polyether polyol, triethanolamine polyether obtained by addition reaction of ethylene oxide and / or propylene oxide. Polyols are preferred.

  In the present invention, the catalyst (3) contains at least one selected from the group consisting of organic acid bismuth, organic acid tin, organic acid zinc, diazabicycloalkene and salts thereof, and polyol-containing Since a high reactivity is obtained by using a specific chain extender described later for the component (1), a polyether polyol having a low reactivity with an isocyanate can also be used. In the present specification, the polyether polyol having a low reactivity is preferably a polyether polyol having the hydroxyl value and the number of functional groups and having no polyoxyethylene group, and the ethylene oxide is ring-opened. Examples include polyoxyalkylene polyols that have not been added. Since such a polyol does not contain a repeating structure of oxyethylene groups, the hygroscopicity of the resulting polyurethane is suppressed, and is preferable from the viewpoint of weather resistance.

  The production of the polyoxyalkylene polyol having no ring-opening addition of ethylene oxide is not particularly limited unless diethylene glycol or ethylene oxide is used as a raw material, and can be performed in the same manner as the production of the polyoxyalkylene polyol described above.

  As the chain extender, a functional group which is an active hydrogen-containing group capable of reacting with a hydroxyl group, a primary amino group, a secondary amino group, or another isocyanate group is used in order to impart hardness / strength to the polyurethane molded product. Examples thereof include a low molecular weight compound having 4 and a molecular weight of 60 to 200, preferably 60 to 150. The 2 to 4 functional groups may be the same or different. Among the compounds having the molecular weight and the number of functional groups, one or more selected from the group consisting of a primary hydroxyl group, a primary amino group, and a secondary amino group is contained in the molecule from the viewpoint of enhancing reactivity and reaction homogeneity. 2 to 4 polyhydric alcohols or alkanolamines are desirable. Further, from the viewpoint of weather resistance, those having no repeating structure of oxyethylene group are desirable. Even when two or more chain extenders are used, the chain extender preferably has an individual molecular weight of 60 to 200 and the number of functional groups of 2 to 4, but some of the chain extenders are used in combination. May be. In that case, the molecular weight and the number of functional groups of the whole chain extender can be represented by the weighted average molecular weight and the weighted average functional group number of the chain extender, and the average molecular weight is 60 to 200, and the average functional group number is 2 to 4. desirable.

  Examples of suitable chain extenders include: ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, pentaerythritol and other polyhydric alcohols, ethanol Examples include alkanolamines such as amine, diethanolamine, triethanolamine, and methyldiethanolamine, and these can be used alone or in admixture of two or more. Among these, ethylene glycol is preferable from the viewpoint of enhancing hardness characteristics, and ethanolamine, diethanolamine, and triethanolamine are preferable from the viewpoint of increasing reactivity simultaneously with the hardness characteristics.

  The amount of the chain extender is preferably 5 to 20 parts by weight, more preferably 7 to 15 parts by weight with respect to 100 parts by weight of the total amount of the polyether polyol from the viewpoint of securing the strength and hardness of the polyurethane molded product. is there.

  The total content of the polyether-based polyol and the chain extender in the polyol-containing component (1) is preferably 75 to 100% by weight, more preferably 85 to 100% by weight, and still more preferably 100% by weight. .

  The polyisocyanate component (2) contains an aromatic polyisocyanate and a modified product thereof, and there is no particular limitation as long as the NCO content is 19 to 28% by weight, preferably 20 to 25% by weight. Examples of those commonly used are shown below.

  Examples of the aromatic polyisocyanate include 4,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, and 2,4′-diphenylmethane diisocyanate, and these are used alone or in admixture of two or more. be able to.

  Examples of the modified aromatic polyisocyanate include urethane modified products of aromatic polyisocyanates, carbodiimide modified products, uretoimine modified products, allophanate modified products, urea modified products, burette modified products, and isocyanurate modified products. The In the present invention, a urethane-modified product having an isocyanate selected from the group consisting of 4,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, and 2,4′-diphenylmethane diisocyanate, a carbodiimide-modified product, It is preferable to contain at least one modified product of a modified uretoimine, modified allophanate, modified urea, modified buret or modified isocyanurate, and may contain a mixture of these modified products. Among these, from the viewpoint of storage stability of the polyisocyanate component, urethane-modified polyisocyanate, carbodiimide-modified polyisocyanate, or a mixture thereof by reaction with a polyether polyol and / or a glycol having a molecular weight of 100 to 200 is preferable.

  The total content of the aromatic polyisocyanate and its modified polyisocyanate component (2) is preferably 75% by weight or more, more preferably 85% by weight or more, and still more preferably, from the viewpoint of imparting hardness and increasing reactivity. It is substantially 100% by weight. In the present invention, when a polyol-containing component (1) having no oxyethylene group repeating structure is used, the hygroscopic property of the resulting polyurethane is suppressed. Even if it is used in a content within the above range, it becomes possible to improve the weather resistance of polyurethane molded products used under ultraviolet irradiation and intermittent water spray conditions (assuming outdoors).

  Moreover, a polyisocyanate component (2) can contain other components in the range which does not impair the effect of this invention other than aromatic polyisocyanate and its modified body. Other components are preferably aliphatic and / or alicyclic polyisocyanates and modified polyisocyanates from the viewpoint of improving the weather resistance.

  Examples of the aliphatic and / or alicyclic polyisocyanates include polyisocyanates obtained from hexamethylene diisocyanate, isophorone diisocyanate, norbornane diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated m-xylene diisocyanate, and among these, polyurethane molding From the viewpoint of increasing the hardness of the product, isophorone diisocyanate and norbornane diisocyanate are preferable. These can be used alone or in admixture of two or more.

  Examples of the modified product of the aliphatic and alicyclic polyisocyanate include the same modified product as the modified product of the aromatic polyisocyanate described above. Of these, isocyanurate-modified products of aliphatic and alicyclic polyisocyanates are preferable from the viewpoint of imparting hardness.

  The total content of the aliphatic polyisocyanate and / or alicyclic polyisocyanate and the modified polyisocyanate is 5 from the viewpoint of improving the weather resistance while maintaining high reactivity in the polyisocyanate component (2). -25% by weight is preferred, and 8-20% by weight is more preferred.

  The ratio of the polyol-containing component (1) containing the polyether polyol and the chain extender and the polyisocyanate component (2) is usually 90 to 115, preferably 95 to 110, more preferably 100 to 108, with an isocyanate index. It is preferable to adjust so that it becomes.

  The catalyst (3) in the present invention contains one or more selected from the group consisting of organic acid bismuth, organic acid tin, organic acid zinc, diazabicycloalkene and salts thereof.

  Examples of the organic acid bismuth include tris (carboxylic acid) bismuth such as tris (2-ethylhexanoic acid) bismuth, resin acid bismuth, and the like. The organic acid bismuth having a bismuth concentration of 10% by weight or more is used. Is preferred. Examples of the organic acid tin include dibutyl tin dilaurate, dibutyl tin dineodecanoate, dialkyl tin dicarboxylate such as dibutyl tin diacetate, dimers thereof and modified products thereof, di (carboxylic acid) tin, and the like. It is preferable to use an organic acid tin having a tin concentration of 15% by weight or more.

  Examples of the organic acid zinc include zinc dicarboxylates such as bis (2-ethylhexanoic acid) zinc and bis (butanoic acid) zinc, and the organic acid zinc having a zinc concentration of 5% by weight or more is used. Is preferred. Diazabicycloalkenes and salts thereof include 1,8-diazabicyclo [5.4.0] undecene-7, 1,5-diazabicyclo [4.3.0] nonene-5, and organic acid salts thereof. It is done. Examples of the organic acid include phenol, carboxylic acid, p-toluenesulfonic acid and the like.

  Among the above compounds, from the viewpoint of catalytic activity, tris (carboxylic acid) bismuth, dialkyltin dicarboxylate, dimer and modified product thereof, zinc dicarboxylate, 1,8-diazabicyclo [5.4.0] undecene. -7 and its organic acid salt, and 1,5-diazabicyclo [4.3.0] nonene-5 and its organic acid salt are preferable, organic bismuth is more preferable, and tris (carboxylic acid) bismuth is more preferable. Further, from the viewpoint of the synergistic effect of the catalytic activity, the combined use of organic acid bismuth and other catalysts, or the combined use of organic acid tin or organic acid zinc and diazabicycloalkene may be performed.

  The total content of organic acid bismuth, organic acid tin, organic acid zinc, diazabicycloalkene and salts thereof in the catalyst (3) is preferably 70% by weight or more, more preferably 80% by weight or more, and substantially 100%. More preferred is weight percent.

  As a preferred example, when the catalyst (3) contains bismuth of an organic acid, the content of the bismuth of the organic acid in the catalyst (3) is preferably 5% by weight or more, more preferably 7% by weight or more in terms of bismuth concentration. More preferred. Further, from the viewpoint of controlling the reactivity and expressing characteristics such as hardness, the content of the organic acid bismuth is preferably 0.01 to 0.15 parts by weight with respect to 100 parts by weight of the total amount of the polyol-containing component (1). More preferably, the content is 0.01 to 0.10 parts by weight, more preferably 0.01 to 0.05 parts by weight, and still more preferably 0.01 to 0.03 parts by weight.

  The amount of the catalyst (3) is particularly important in the production of a polyurethane molded product from the viewpoint of controlling the reactivity, but it is desirable to appropriately adjust the reaction activity depending on the type of the catalyst. The amount of the catalyst (3) is preferably 0.03 to 0.18 parts by weight, more preferably 0.04 to 0.13 parts by weight, still more preferably 100 parts by weight of the total amount of the polyol-containing component (1) and the polyisocyanate component (2). 0.04 to 0.08 parts by weight.

  The catalyst (3) can be used by mixing with the polyol-containing component (1) and / or the polyisocyanate component (2). In the present invention, the polyol-containing component is used from the viewpoint of the stability of the polyisocyanate component. It is preferable to use a mixture in (1). In addition, each catalyst contained in the catalyst (3) may be mixed in advance and mixed with the polyol-containing component (1) or the polyisocyanate component (2), and the polyol-containing component (1) or polyisocyanate is separately added. You may mix with a component (2).

  In the present invention, a foaming agent can be used. As the foaming agent, known foaming agents other than water can be used, but it is preferable to use a pressurized fluid from the viewpoint of maintaining the surface property and suppressing the decrease in hardness. The pressurized fluid means a fluid placed under a pressurized state, and among them, a supercritical fluid or a subcritical fluid is preferable, and a supercritical fluid, that is, A supercritical gas is more preferable. Supercritical state and subcritical state are subordinate concepts under pressure, and “supercritical state” is generally a state where the pressure is higher than the critical pressure and the temperature is higher than the critical temperature. `` Subcritical state '' usually means a state where the temperature is not less than the triple point and not more than the critical point and the pressure is equal to or higher than the saturated vapor pressure, and the temperature-pressure range conforms to the supercritical state. To do. In the present invention, the “subcritical state” means more specifically, when the blowing agent is carbon dioxide, the temperature and pressure are in the range of 25 ° C. or more and less than 31.1 ° C., in the range of more than 7.38 MPa, and 25 ° C. or more and 45 It includes a state in a range of 4 ° C. or lower and lower than 7.38 MPa.

  The fluid species of the supercritical gas is not particularly limited, and examples thereof include an inert gas such as carbon dioxide and nitrogen. Carbon dioxide is preferable from the viewpoint of high solubility in the polyurethane raw material. In the present invention, the supercritical gas refers to a supercritical gas or gas that has been adjusted to a supercritical state by mixing the temperature and pressure with other components, and then adjusted to a supercritical state by adjusting the temperature and pressure. The gas of the aspect mentioned above and the gas containing the aspect of both are said.

  As the conditions for bringing the fluid into a supercritical state, for example, when the fluid species is carbon dioxide, the pressure is equal to or higher than the critical pressure of carbon dioxide (7.38 MPa), and the temperature is the critical temperature (31.1 ° C.). The conditions above the critical point (7.38 MPa, 31.1 ° C.) are preferable because carbon dioxide is in a supercritical state. More specifically, conditions where the temperature is 31 to 80 ° C. and the pressure is 7.38 to 40 MPa are preferable, and conditions where the temperature is 31 to 60 ° C. and the pressure is 7.84 to 20 MPa are more preferable. . When the fluid species is nitrogen gas, in order for the nitrogen gas to be in a supercritical state, the critical pressure of the nitrogen gas is 3.40 MPa and the critical temperature is −147 ° C., specifically, Conditions under which the temperature is −140 to 80 ° C. and 3.4 to 20 MPa are preferable.

  The foaming agent can be used by mixing with the polyol-containing component (1) and / or the polyisocyanate component (2) and dissolving in the component. In the present invention, carbon dioxide is used as the foaming agent. In addition, when the polyol-containing component contains an amine compound having a primary amino group or a secondary amino group, the polyisocyanate component (2) is used in order to avoid carbamate formation between carbon dioxide and the amine compound. It is preferable to use after dissolving.

  In the production method of the present invention, an auxiliary can be used if necessary. As the auxiliary agent, those generally used in the production of polyurethane can be used. Examples of the auxiliary agent include deterioration preventing agents and pigments, and these auxiliary agents can be used within a range that does not impair the object of the present invention.

  When the polyurethane molded product obtained by the method of the present invention is used for weather resistance, it is preferable to add a deterioration inhibitor or the like to the polyurethane raw material. The deterioration inhibitor preferably contains an ultraviolet absorber and a light stabilizer.

  As the ultraviolet absorber, benzotriazole type is preferable, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzo. Triazole, 2- (2-hydroxy-3,5-di-t-amylphenyl) benzotriazole, 2- (2-hydroxy-5-t-octylphenyl) benzotriazole, 2- (2-hydroxy-3-dodecyl) -5-methylphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] benzotriazole, 3- [3-t-butyl-5- (2H-benzotriazole) -2-yl) -4-hydroxyphenyl] propionate and a condensation product of polyethylene glycol and the like. .

  As the light stabilizer, a hindered amine radical scavenger is preferable, and bis [1,2,2,6,6-pentamethyl-4-piperidyl] sebacate, commonly called HALS, bis [1,2,2,6,6- Examples include pentamethyl-4-piperidyl] -2-n-butyl-2- (3,5-di-t-butyl-4-hydroxybenzyl) malonate.

  Moreover, in view of the heat resistance stability by the RIM method, it is preferable to contain a degradation inhibitor such as a hindered phenol-based antioxidant or a peroxide decomposing agent as long as the effects of the present invention are not impaired.

  Examples of hindered phenol antioxidants include dibutylhydroxytoluene, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], isooctyl-3- (3,5- And di-t-butyl-4-hydroxyphenyl) propionate, triethylene glycol-bis- [3- (3-t-butyl-4-hydroxy-5-methylphenyl)] propionate.

  Examples of the peroxide decomposer include phosphites such as tris (nonylphenyl) phosphite, monophenylbis (nonylphenyl) phosphite, tris (lauryl) phosphite, and tris (2-ethylhexyl) phosphite.

  The total content of the ultraviolet absorber and the light stabilizer in the deterioration preventing agent is preferably 30% by weight or more, and more preferably 40% by weight or more.

  The amount of the deterioration inhibitor is preferably 0.5 to 3.0 parts by weight, more preferably 0.7 parts per 100 parts by weight of the total amount of the polyol-containing component (1) and the polyisocyanate component (2) from the viewpoint of weather resistance and heat resistance. It is -2.5 weight part, More preferably, it is 1.0-2.0 weight part.

  Examples of the pigment include those generally used for polyurethane as a colorant, such as carbon black and titanium oxide, and those that are kneaded in a polyether polyol in advance and adjusted to have a pigment concentration of 15 to 50% by weight. preferable.

  The amount of the pigment is important in the production of polyurethane molded products from the viewpoint of controlling the color, but it is desirable to adjust appropriately because the color varies depending on the type and concentration of the pigment. The amount of the pigment is preferably 0.1 to 4 parts by weight, more preferably 0.15 to 3 parts by weight, and still more preferably 0.2 to 2 parts per 100 parts by weight of the total amount of the polyol-containing component (1) and the polyisocyanate component (2). Parts by weight.

  According to the method of the present invention, using a known reaction injection molding machine, for example, a polyol-containing component (1) containing a polyether-based polyol and a chain extender is mixed with organic acid bismuth, organic acid tin, organic acid zinc, And a polyisocyanate component (2) in a mold under the presence of a catalyst (3) containing at least one member selected from the group consisting of diazabicycloalkenes and salts thereof. Can be manufactured.

  In the case of producing a foamed polyurethane molded product, the gas in the supercritical state can be introduced using a reaction injection molding machine equipped with a supercritical gas introduction unit, and also in the polyol-containing component (1). It can also be introduced into the polyisocyanate component (2). An example of such a reaction injection molding machine is MCF-RIM (Microcellular reaction injection molding machine, manufactured by Kawata).

  According to the method for producing a polyurethane molded product of the present invention, the solidification time is 10 seconds or less, preferably 8 seconds or less, so that the production cycle of the RIM method can be shortened and the productivity can be improved. The polyurethane molded product thus obtained is excellent in appearance and can be suitably used as a sealing material for automobiles, a sealing material for building materials, a vibration damping material, a cushioning material, a polishing pad and the like. In the present specification, solidification means a state having no fluidity.

Further, the density of the obtained polyurethane molded product is preferably 0.3 to 1.20 g / cm ³ from the viewpoint of securing foam strength and dimensional stability. The density of the obtained polyurethane molded product is preferably 0.3 to 0.95 g / cm ³ , more preferably 0.3 to 0.90 g / cm ³ , and still more preferably, from the viewpoint of securing foam strength and dimensional stability. Is 0.5 to 0.85 g / cm ³ . Moreover, as a sealing material for motor vehicles, 0.60-0.95 g / cm < ³ > is preferable and 0.65-0.95 g / cm < ³ > is preferable from a viewpoint of maintaining foam strength, dimensional stability, and the external appearance favorable. More preferably, the sunroof sealing material for automobiles is more preferably 0.70 to 0.95 g / cm ³ . The hardness is preferably 65 to 98, more preferably 75 to 98, from the viewpoint of foam strength and flexibility. In addition, in this specification, a density and hardness are measured by the method as described in the below-mentioned Example.

Polyol-containing composition production examples 1-1 to 8
In the formulation shown in Table 1, polyol-containing components, catalysts, auxiliaries, and pigments were mixed to obtain polyol-containing compositions 1-A to H filled in a reaction injection molding machine together with a polyisocyanate component.

In addition, each raw material of Table 1 shows the following.
Polyol 1-A: Polyoxypropylene polyether polyol having ethylene oxide added to the end (hydroxyl value: 35 mgKOH / g, functional group number: 3, manufactured by Sumika Bayer Urethane Co., Ltd., trade name: Sumifene 3900)
Polyol 1-B: Polyoxypropylene polyether polyol having ethylene oxide added to the terminal (hydroxyl value: 28 mgKOH / g, number of functional groups: 2, manufactured by Asahi Glass Urethane Co., Ltd., trade name: Exenol 510)
EG: ethylene glycol (molecular weight: 62, functional group number: 2)
DEA: Diethanolamine (molecular weight: 105, functional group number: 3)
・ TOBi: Tris (2-ethylhexanoic acid) bismuth [manufactured by Nippon Chemical Industry Co., Ltd., trade name: PACCAT 25, Bi concentration 25 wt%] (organic acid bismuth-based catalyst)
DBTDL: Dibutyltin dilaurate [manufactured by Nitto Kasei Co., Ltd., trade name: Neostan U-100, Sn concentration: 18% by weight] (Organic acid tin-based catalyst)
-DOZn: Bis (2-ethylhexanoic acid) zinc [Nippon Chemical Industry Co., Ltd., trade name: Nikka Octix Zn, Zn concentration 8% by weight] (organic acid zinc-based catalyst)
DBU: 1,8-diazabicyclo [5.4.0] undecene-7 [manufactured by San Apro, trade name: DBU] (diazabicycloalkene-based catalyst)
KL-31: 1,4-diazabicyclo [2.2.2] octane in 33% dipropylene glycol solution [trade name: Kao Riser No. 31]
IRGANOX 245: hindered phenol antioxidant (Ciba Specialty Chemicals)
TINUVIN 571: Benzotriazole UV absorber (Ciba Specialty Chemicals)
TINUVIN 765: hindered amine light stabilizer (Ciba Specialty Chemicals)
JP-312L: Tris (lauryl) phosphite [manufactured by Johoku Chemical Co., Ltd.]
Pigment: carbon black [manufactured by Nippon Pigment Co., Ltd., trade name: NV-7-693, carbon black content 40%]

Polyisocyanate component production example 1-1
Charge 20 kg of 4,4'-diphenylmethane diisocyanate (trade name: Millionate MT, manufactured by Nippon Polyurethane Co., Ltd.) into the reaction kettle, and add 2.45 kg of dipropylene glycol while stirring in a nitrogen atmosphere so that the reaction temperature is 90 ° C or lower. Gradually added over 2 hours while adjusting. Thereafter, 1.18 kg of polyol 1-B was added and aged at 60 ° C. for 2 hours with stirring to obtain polyisocyanate component 1-A containing urethane-modified polyisocyanate. The obtained polyisocyanate component 1-A had an NCO content of 21.8% by weight.

Polyisocyanate component production example 1-2
Add 4.5 kg of polyisocyanate component 1-A to the reaction kettle, add 0.5 kg of carbodiimide-modified isocyanate (manufactured by Nippon Polyurethane Co., Ltd., product name: Coronate MX) with stirring in a nitrogen atmosphere, and mix at 60 ° C. for 1 hour. Polyisocyanate component 1-B containing urethane-modified polyisocyanate and carbodiimide-modified polyisocyanate was obtained. The obtained polyisocyanate component 1-B had an NCO content of 22.5% by weight.

Examples 1-1 to 9 and Comparative Examples 1-1 to 2 (polyurethane molded products)
The polyol-containing composition and the polyisocyanate component shown in Table 2 were filled in the molding machine shown in Table 2, each was temperature-controlled at 35 ° C., mixed, and then subjected to Examples 1-1 to 9-9 under the conditions shown in Table 2. The polyurethane molded articles of Comparative Examples 1-1 and 2 were produced. In Examples 1-8 and 9 where carbon dioxide in a supercritical state was used as a foaming agent, a supercritical gas and a polyisocyanate component were premixed and further mixed with a polyol-containing composition in a molding machine. Thus, molded products 1-8 and 9 were produced.

The blending ratio of the polyol-containing composition and the polyisocyanate component is expressed by the formula:
[Isocyanate index]
= [Amount of isocyanate actually used]
÷ (isocyanate amount stoichiometrically equivalent to polyol) × 100
Was adjusted so that the isocyanate index determined on the basis of

  The physical properties of the obtained polyurethane were examined according to the methods of Test Examples 1-1 to 1-4 below. The results are shown in Table 2.

[Test Example 1-1] (Reactivity)
The time when the polyurethane solidified (no fluidity) was measured as follows.
A 1 liter polycup with an open casting port is used as a pseudo mold for reactivity evaluation, and 360 g of a mixture of raw materials is cast from an injection molding machine. The time from the casting until the mixture does not flow even if the polycup is inverted while the mixture is cast is defined as the solidification time.

[Test Example 1-2] (Density)
The polyurethane molded product was allowed to stand at 25 ° C. for 1 day, and then the weight was divided by the volume as the polyurethane molded product.

[Test Example 1-3] (Hardness)
The polyurethane molded product was allowed to stand at 25 ° C. for 1 day, and then determined using a Shore A hardness meter.

[Test Example 1-4] (Appearance)
The surface of the polyurethane molded product was visually observed. A case where the surface was clean and there were almost no pinholes of Φ0.5 mm or more was judged good, and a case where pinholes occurred frequently on the surface was judged as defective.

From the above results, the polyurethane molded articles of Examples 1-1 to 9 using the catalyst containing organic acid bismuth, organic acid tin, organic acid zinc, diazabicycloalkene were solidified in spite of a small amount of catalyst. The time is 10 seconds or less, and it can be seen that it can be manufactured quickly. In particular, Examples 1-1 and 7 use only bismuth organic acid as a catalyst, but they exhibit sufficiently high reactivity even at a very small amount of 0.017 parts by weight with respect to 100 parts by weight of the polyol-containing component, Short setting time. In addition, Example 1-8 using a blowing agent with carbon dioxide in a supercritical state, compared with Comparative Example 1-2, gives a polyurethane molded product having high hardness and good appearance even at the same density, It has been found that the method of the present invention is also suitable when the density is reduced by foaming using a gas in a supercritical state. Further, the same foaming agent as in Example 1-8 was used, but the polyurethane molded product of Example 1-9 having a density of 0.78 g / cm ³ is a urethane foam having a controlled density and also has a hardness of Since it is good and can be rapidly produced with a solidification time of 4.5 seconds, it can be seen that the polyurethane molded product obtained by the method of the present invention is an effective material as a sealing material for automobile sunroofs.

Polyol-containing component production examples 2-1 to 4
The raw materials shown in Table 3 were mixed to obtain polyol-containing components 2-A to D.

In addition, each raw material of Table 3 shows the following.
Polyol 2-A: Polyoxypropylene-based polyether polyol having no polyoxyethylene group (hydroxyl value: 56 mgKOH / g, number of functional groups: 3, manufactured by Mitsui Chemicals Polyurethanes, Inc., trade name: Actol MN-3050 one)
Polyol 2-B: Polyoxypropylene polyether polyol having no polyoxyethylene group (hydroxyl value: 35 mg KOH / g, number of functional groups: 2, manufactured by Asahi Glass Urethane Co., Ltd., trade name: Exenol 3020)
Polyol 2-C: Polyoxypropylene polyether polyol having ethylene oxide added to the end (hydroxyl value: 35 mgKOH / g, functional group number: 3, manufactured by Sumika Bayer Urethane Co., Ltd., trade name: Sumifene 3900)
EG: ethylene glycol (molecular weight: 62, functional group number: 2)
DEA: Diethanolamine (molecular weight: 105, functional group number: 3)

Polyisocyanate component production example 2-1 (aromatic polyisocyanate)
Charge 20 kg of 4,4'-diphenylmethane diisocyanate (product name: Millionate MT, manufactured by Nippon Polyurethane Co., Ltd.) into the reaction kettle, and add 2.45 kg of dipropylene glycol with stirring in a nitrogen atmosphere so that the reaction temperature is 90 ° C or lower. Gradually added over 2 hours while adjusting. Thereafter, 1.18 kg of polyol 2-B was added and aged at 60 ° C. for 2 hours with stirring to obtain polyisocyanate component 2-A containing urethane-modified polyisocyanate. The obtained polyisocyanate component 2-A had an NCO content of 21.8% by weight.

Polyisocyanate component production example 2-2 (aromatic polyisocyanate)
Add 4.5 kg of polyisocyanate component 2-A to the reaction kettle, add 0.5 kg of carbodiimide-modified isocyanate (manufactured by Nippon Polyurethane Co., Ltd., product name: Coronate MX) with stirring in a nitrogen atmosphere, and mix at 60 ° C. for 1 hour. Polyisocyanate component 2-B containing urethane-modified polyisocyanate and carbodiimide-modified polyisocyanate was obtained. The obtained polyisocyanate component 2-B had an NCO content of 22.5% by weight.

Polyisocyanate component production example 2-3 (aliphatic polyisocyanate)
IPDI [isophorone diisocyanate (manufactured by Sumika Bayer Urethane Co., Ltd., trade name: Desmodur I)] 2.5 kg and IPDI trimer [isophorone diisocyanate isocyanurate body (manufactured by Degussa, trade name: VESTANATE T-1890 / 100)] 2.5 kg was added and dissolved and mixed with stirring at 60 ° C. in a nitrogen atmosphere to obtain polyisocyanate component 2-C. The obtained polyisocyanate component 2-C had an NCO content of 27.5% by weight.

Examples 2-1 to 11 and Comparative Examples 2-1 to 2 (polyurethane molded products)
The polyol-containing component, the catalyst, the deterioration inhibitor and the pigment shown in Table 4 were mixed, and the resulting mixture and the polyisocyanate component shown in Table 4 were filled in the molding machine shown in Table 4, and the temperature was adjusted to 35 ° C., respectively. Then, it mixed and inject | poured in the metal mold | die on the conditions shown in Table 4, and manufactured the polyurethane molded product of Examples 2-1-11 and Comparative Examples 2-1-2. In Examples 2-7 to 9 using carbon dioxide in a supercritical state as a foaming agent, a supercritical state gas and a polyisocyanate component are premixed, and further mixed with a polyol-containing composition in a molding machine for foaming. A polyurethane molded article was produced. In the case of Comparative Example 2-2, a polyurethane foam molded article was produced in the same manner as in Example 2-1, except that water was previously mixed with the polyol-containing component.

The blending ratio of the mixture containing the polyol-containing component and the polyisocyanate component is expressed by the formula:
[Isocyanate index]
= [Amount of isocyanate actually used]
÷ (isocyanate amount stoichiometrically equivalent to polyol) × 100
Was adjusted so that the isocyanate index determined on the basis of

In addition, each raw material of Table 4 shows the following.
・ TOBi: Tris (2-ethylhexanoic acid) bismuth [manufactured by Nippon Chemical Industry Co., Ltd., trade name: PACCAT 25, Bi concentration 25 wt%] (organic acid bismuth-based catalyst)
DBU: 1,8-diazabicyclo [5.4.0] undecene-7 [manufactured by San Apro, trade name: DBU] (diazabicycloalkene-based catalyst)
KL-31: 1,4-diazabicyclo [2.2.2] octane in 33% dipropylene glycol solution [trade name: Kao Riser No. 31]
・ TINUVIN 571: Benzotriazole-based UV absorber (Ciba Specialty Chemicals)
TINUVIN 765: hindered amine light stabilizer (Ciba Specialty Chemicals)
IRGANOX 245: hindered phenol antioxidant (Ciba Specialty Chemicals)
JP-312L: Tris (lauryl) phosphite (peroxide decomposer) [manufactured by Johoku Chemical Co., Ltd.]
NV-7-693: Carbon black (pigment) [Nihon Pigment Co., Ltd., carbon black content 40%]
NV-7-981: Carbon black (pigment) [Nihon Pigment Co., Ltd., carbon black content 25%]

  The physical properties of the obtained polyurethane were examined according to the methods of Test Examples 2-1 to 5 below. The results are shown in Table 4.

[Test Example 2-1] (Reactivity)
The time when the polyurethane solidified (no fluidity) was measured as follows.
A 1 liter polycup with an open casting port is used as a pseudo mold for reactivity evaluation, and 360 g of a mixture of raw materials is cast from an injection molding machine. The time from the casting until the mixture did not flow even if the polycup was inverted while the mixture was cast was defined as the solidification time.

[Test Example 2-2] (Density)
The polyurethane molded product was allowed to stand at 25 ° C. for 1 day, and then the weight was divided by the volume as the polyurethane molded product.

[Test Example 2-3] (Hardness)
The polyurethane molded product was allowed to stand at 25 ° C. for 1 day, and then determined using a Shore A hardness meter.

[Test Example 2-4] (Weather resistance)
A sunshine / weather meter (manufactured by Suga Test Instruments Co., Ltd .: model number WEL-SUN-DC-8) was used, and the test was conducted in accordance with the accelerated weather resistance test of JIS D 0205. The conditions of the weather resistance test were: black panel temperature 63 ° C, humidity 50%, continuous sunshine exposure with sunshine carbon arc lamp, exposure time 720 hours, 60 minutes unit irradiation, 12 minutes irradiation and continuous fountain, 48 minutes irradiation It was only a condition. The color difference (ΔE) before and after the weather resistance test of the polyurethane molded product was measured with a color difference meter [manufactured by Konica Minolta Sensing, product number: CR-400]. The smaller ΔE, the better the weather resistance.

[Test Example 2-5] (Surface properties after weather resistance test)
The surface of the polyurethane molded product after the test in Test Example 2-4 was visually observed and compared with the state before the test in Test Example 2-4. A case where gloss remained on the surface was judged good, and a case where the surface was rough and lost gloss was judged as bad.

From the above results, the polyurethane molded articles of Examples 2-1 to 11 using the polyether-based polyol having no polyoxyethylene group use a specific catalyst of bismuth organic acid and diazabicycloalkene. In addition, it can be seen that it is highly reactive and can be rapidly produced with a solidification time of 10 seconds or less. In addition, Example 2-7 using carbon dioxide in a supercritical state as a foaming agent has high hardness at the same density as compared with Comparative Example 2-2, which is the same foam, and also has reactivity and weather resistance. An excellent polyurethane molded article was obtained, and it was found that the method of the present invention is suitable even when foaming and reducing the density using a gas in a supercritical state. Furthermore, although using the same blowing agent as in Example 2-7, the density is respectively 0.62 g / cm ^3, a polyurethane molded article of Example 2-8,9 is 0.82 g / cm ^3, the hardness and weatherability Since the property is good and the solidification time can be rapidly produced as 10 seconds or less, it can be seen that the polyurethane molded product obtained by the method of the present invention is an effective material as a sealing material for automobile sunroofs. Furthermore, even in a molded article using only an aromatic isocyanate that has not been used because of poor weather resistance, although it is advantageous in terms of production cost, it has shown extremely good weather resistance. Recognize.

The polyurethane molded product obtained by the production method of the present invention can be suitably used as, for example, an automobile sealing material, a building material sealing material, a vibration damping material, a cushion material, a polishing pad, and the like.

Claims (10)

  A method for producing a polyurethane molded product by a reaction injection molding method, which is a polyether polyol having a hydroxyl value of 15 to 60 mg KOH / g, a functional group number of 2 to 4, a molecular weight of 60 to 200, and a functional group number of 2 to 4. A polyol-containing component (1) containing a chain extender, a polyisocyanate component (2) containing an aromatic polyisocyanate and a modified product thereof and having an NCO content of 19 to 28% by weight, bismuth organic acid, organic It is under the condition in which a catalyst (3) containing at least one selected from the group consisting of tin oxide, organic acid zinc, and diazabicycloalkene and a salt thereof exists, and substantially contains water. A process for producing a polyurethane molded product, which is allowed to react under no conditions and solidify in 10 seconds or less.   The polyether polyol having 2 to 4 functional groups is a polyether polyol having no polyoxyethylene group, and the reaction between the polyol-containing component (1) and the polyisocyanate component (2) is carried out using a catalyst (3), The method for producing a polyurethane molded product according to claim 1, which is carried out under the condition that the deterioration inhibitor (4) containing the ultraviolet absorber and the light stabilizer and the pigment (5) are present.   The manufacturing method of Claim 1 or 2 whose total content in the polyisocyanate component (2) of aromatic polyisocyanate and its modification is 75 weight% or more.   The polyisocyanate component (2) further contains an aliphatic polyisocyanate and / or an alicyclic polyisocyanate and an isocyanurate-modified product of the polyisocyanate in the polyisocyanate component (2) in a total amount of 5 to 25% by weight. The manufacturing method in any one of Claims 1-3 which becomes.   The manufacturing method in any one of Claims 1-4 made to react in presence of the gas of a supercritical state.   The production method according to claim 5, wherein the gas in a supercritical state is carbon dioxide.   The chain extender is a polyhydric alcohol or alkanolamine having 2 to 4 in the molecule of at least one selected from the group consisting of a primary hydroxyl group, a primary amino group and a secondary amino group. 6. The production method according to any one of 6.   A modified urethane having a structural unit of an isocyanate selected from the group consisting of 4,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, and 2,4′-diphenylmethane diisocyanate, The production method according to any one of claims 1 to 7, which is at least one modified body of a carbodiimide modified body, a uretoimine modified body, an allophanate modified body, a urea modified body, a burette modified body or an isocyanurate modified body.   A polyurethane molded product obtained by the production method according to claim 1. Density used as a sealing material for automobiles is 0.65~0.95g / cm ^3, claim 9 polyurethane molded article according.