JP5458753B2 - Polyester polyol for polyurethane foam - Google Patents

Description

  The present invention relates to polyester polyols for polyurethane foams. Specifically, it is low in viscosity and easy to handle, and is particularly suitable for water-foamed rigid polyurethane foams, and can obtain polyurethane foams excellent in physical properties. The present invention relates to a polyester polyol for polyurethane foam.

  For example, rigid polyurethane foams are widely used in refrigerators, refrigerators, freezers, freezers, heat insulating materials for general buildings, etc., because they have excellent heat insulation properties and flame retardancy. Rigid polyurethane foam is generally a mixture of a polyisocyanate component liquid (hereinafter abbreviated as "A liquid"), a polyether polyol and / or polyester polyol, a foaming agent, and a catalyst or surfactant as necessary. , Abbreviated as B liquid), A liquid and B liquid are mixed, and foamed and cured in a short time.

  As the blowing agent, a low boiling nonpolar organic solvent is generally used. Specifically, in addition to so-called Freon such as CFC-based blowing agent, HCFC-based blowing agent and HFC-based blowing agent, alternative freon, pentane, HC-based foaming agents such as cyclopentane are used, but since the destruction of the ozone layer has become a problem, the ozone-depleting coefficient is small compared to CFC-based foaming agents, especially CFC-11e, etc. HCFC-based blowing agents, especially HCFC-141b, have been used instead. However, this HCFC-141b is not zero in ozone depletion coefficient, and its use has been restricted since the end of 2003. As an alternative, HFC-based foaming agents, particularly HFC-245fa and HFC-365mfc are used. HC foaming agents are also promising foaming agents.

  However, since the above blowing agents are global warming substances and are very expensive, from the viewpoint of environmental protection and economics, the amount used is reduced, and therefore these blowing agents are not used at all. A water foaming technique using a carbon dioxide gas generated by a reaction with a polyisocyanate component as a foaming agent is also progressing.

  However, there are the following major problems in spreading the water foaming technology. That is, compared with conventional foaming formulations using HCFC foaming agents and HFC foaming agents, it is not possible to obtain a thinning effect such as chlorofluorocarbon, so that the viscosity of liquid B is increased, and water and polyisocyanate components In particular, due to the influence of the increase of urea groups produced by the reaction with, the brittleness of the surface and bottom of the resulting rigid urethane foam is likely to deteriorate and the adhesive strength with the adherend tends to decrease, and the flame retardancy It may be worsened.

  As a method for improving the above-mentioned disadvantage of the adhesiveness decrease due to the viscosity of the B liquid and the brittleness of the rigid urethane foam, an auxiliary agent having no hydroxyl group such as dialkyl ether of oxyethylene and / or oxypropylene glycol is used. The method to use (refer patent document 1) and the method (refer patent document 2) which mix | blends the auxiliary agent whose hydroxyl group is 0 or 1 similarly like a phosphate ester type compound and an alkylphenol type compound are proposed. In addition, a general-purpose thinning agent such as propylene carbonate is partially added to the B liquid. However, in these methods, if the amount added is small, the effect of improving brittleness and adhesive strength is small, and if the amount added is large, the cost is disadvantageous, and the strength, dimensional stability, and flame retardancy of the rigid polyurethane foam are reduced. Adverse effects such as further degradation may occur.

  In addition, a flame retardant obtained by reacting one or more compounds selected from aromatic monocarboxylic acids with one or more compounds selected from polybasic acids and one or more compounds selected from polyhydric alcohols. A polyester polyol composition has been proposed (see Patent Document 3). And in the Example in such a proposal, although phthalic anhydride is used as a polybasic acid, it is inadequate from a viewpoint of an improvement of a flame retardance.

JP 2002-363241 A Japanese Patent Laid-Open No. 2000-281741 Japanese Patent No. 3153875

  Therefore, the object of the present invention can be suitably used as a raw material for water-foamed rigid polyurethane foam, in particular, (1) Prevention of viscosity reduction of B liquid, (2) Prevention of adhesion deterioration due to deterioration of brittleness of rigid urethane foam, (3 ) To provide a polyester polyol for polyurethane foam which can realize improvement or maintenance of flame retardancy.

  As a result of intensive studies to achieve the above object, the present inventor has found a combination of carboxylic acid components not specifically disclosed in the above-mentioned proposal of flame retardant polyester polyol composition (Patent Document 3). By adopting it, it was found that the above object could be easily achieved, and the present invention was completed.

  That is, the gist of the present invention is a polyester polyol for polyurethane foam obtained by an esterification reaction of a carboxylic acid component and diethylene glycol, and the carboxylic acid component includes fumaric acid and / or maleic together with benzoic acid and phthalic acid. Acid, and the proportion of benzoic acid in these carboxylic acid components is 10 to 70 mol%, fumaric acid and / or maleic acid is 10 to 70 mol%, and the proportion of phthalic acid is 1 mol% or more. It exists in the polyester polyol for polyurethane foams characterized by being (however, the sum total of these carboxylic acids is 100 mol%).

  According to the present invention, the above-described problems can be solved.

  Hereinafter, the present invention will be described in detail.

  The polyester polyol for polyurethane foam of the present invention is obtained by esterification reaction of a carboxylic acid component and diethylene glycol, and fumaric acid and / or maleic acid is used together with benzoic acid and phthalic acid as the carboxylic acid component. is important.

  That is, fumaric acid and / or maleic acid, which are unsaturated carboxylic acids, are more carbonizable than saturated aliphatic polyvalent carboxylic acids, so polyester polyols can be reduced without significantly affecting the flame retardancy of rigid urethane foam. Viscosity can be achieved, and brittleness and adhesion of the resulting rigid urethane foam can be improved.

  In the present invention, when fumaric acid and / or maleic acid is used together with benzoic acid and phthalic acid, the ratio of benzoic acid in these carboxylic acid components is 10 to 70 mol%, fumaric acid and / or The proportion of maleic acid must be 10 to 70 mol%, and the proportion of phthalic acid must be 1 mol% or more (provided that the total of these carboxylic acids is 100 mol%).

  When the proportion of benzoic acid is less than 10 mol%, the effect of lowering the viscosity of the resulting polyester polyol is small, and when it exceeds 70 mol%, the average number of functional groups of the polyester polyol is reduced, and the resulting rigid polyurethane foam There is a possibility of deteriorating mechanical strength. The proportion of benzoic acid is preferably 5 to 65 mol%, more preferably 20 to 60 mol%.

  When the ratio of fumaric acid and / or maleic acid is less than 10 mol%, the effect of improving the brittleness of the resulting rigid urethane foam is small, and when it exceeds 70 mol%, the aromatic ring concentration of the polyester polyol is lowered and obtained. There is a possibility of deteriorating the flame retardancy of the rigid polyurethane foam. The ratio of fumaric acid and / or maleic acid is preferably 15 to 65 mol%, more preferably 20 to 60 mol%. Note that fumaric acid and maleic acid may be used alone or in combination.

  When the ratio of phthalic acid is less than 1 mol%, the flame retardancy of the rigid urethane foam is lowered. The proportion of phthalic acid is preferably 2 mol% or more, more preferably 3 mol% or more.

  In addition, each said carboxylic acid may use derivatives, such as an acid anhydride and methyl ester, respectively. In the case of acid anhydrides and esterified products, the amounts used are calculated in mol% converted to the original benzoic acid, fumaric acid, maleic acid, phthalic acid, and the like.

  In the present invention, as carboxylic acids other than the above carboxylic acids, terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, azelaic acid, het acid, dimer Carboxylic acids commonly used in the production of polyester polyols such as acid, malic acid, citric acid and acetic acid can be used in combination. These may be used as derivatives such as acid anhydrides and methyl esters, respectively. When these carboxylic acids are used in combination, the amount used is usually 10 mol% or less of the total carboxylic acid component.

  In the present invention, diethylene glycol is used as the alcoholic acid component as a raw material, for the following reason. That is, when an alkylene glycol such as ethylene glycol, 1,4-butanediol, or 1,6-hexanediol is used, the resulting polyester polyol may solidify or have a significantly increased viscosity. Also, in the case of using oxyalkylene glycol having a molecular weight larger than that of diethylene glycol such as triethylene glycol or tetraethylene glycol, the aromatic ring concentration is lowered, so that the flame resistance of the obtained rigid polyurethane foam is deteriorated. there is a possibility.

  For the above reasons, the total amount of the alcohol component is preferably diethylene glycol, but the following alcohols can be used in a range that does not adversely affect, that is, a range of about 10 mol% or less.

  For example, in alkylene glycol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1, Examples include 3-propanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, and the like. For oxyalkylene glycol, long-chain polyether polyols such as triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, polyoxyethylene / oxypropylene copolymer glycol, polytetramethylene ether glycol, etc. Is mentioned. Further, trifunctional or higher functional alcohols such as glycerin, trimethylolpropane and pentaerythritol can be used in combination. Two or more of these may be used in combination.

  The hydroxyl value of the polyester polyol of the present invention is usually in the range of 30 to 300 mgKOH / g, preferably 40 to 290 mgKOH / g, more preferably 50 to 270 mgKOH / g. When the hydroxyl value is less than 30 mgKOH / g, the mechanical strength of the resulting rigid urethane foam may be lowered. On the other hand, if it is larger than 300 mgKOH / g, the molecular weight distribution of a large amount of unreacted alcohol is obtained, the effect of improving brittleness and adhesiveness is reduced, and the use amount of the polyisocyanate component is increased, which is disadvantageous in terms of cost.

  The viscosity of the polyester polyol of the present invention at 25 ° C. is usually 5000 mPa · s or less, preferably 4000 mPa · s or less, more preferably 3000 mPa · s or less. When it is higher than 5000 mPa · s, there is a possibility that the handling may be hindered or problems such as the inability to perform spraying may occur during the production of rigid urethane foam.

  The average number of functional groups of the polyester polyol of the present invention is generally 1.05 to 3.0, preferably 1.1 to 2.5. When the average number of functional groups is less than 1.05, adverse effects such as a decrease in mechanical strength and dimensional stability of the rigid polyurethane foam may occur. On the other hand, when it is larger than 3.0, the viscosity of the polyester polyol is increased, which may cause a problem.

  Moreover, as a method for lowering the viscosity of the polyester polyol, a monohydric alcohol such as methanol, ethanol, isopropanol, or 2-ethylhexanol can be used in combination. However, when these monohydric alcohols are used, it is important that the hydroxyl value and the number of functional groups are not deviated from the above ranges. Furthermore, in the synthesis of polyester polyol, it may be distilled out of the reaction system to deteriorate the yield, or it may adversely affect the strength and heat resistance of the polyurethane foam using the obtained polyester polyol. It is preferable to use in the range which does not become.

  In the esterification reaction in the present invention, an esterification catalyst is usually used. In general, an acid catalyst is often used as the catalyst. As the Lewis acid, for example, orthotitanate such as tetraisopropyl titanate and tetra-n-butyl titanate, tin compounds such as diethyltin oxide and dibutyltin oxide, and metal compounds such as zinc oxide are used. In addition to the Lewis acid, a Bronsted acid such as p-toluenesulfonic acid may be used.

  The polyester polyol of the present invention is urethanated with a polyisocyanate component to become polyurethane. At this time, it is desirable that the catalyst used for the synthesis of the polyester polyol does not affect the reaction behavior of the urethanization reaction. Therefore, among the above esterification catalysts, orthotitanate is preferable. Moreover, the usage-amount is 0.01-1.0 weight% normally with respect to the sum total of the carboxylic acid component and alcohol component which are used for a raw material, Preferably it is 0.03-0.2 weight%. Depending on the use of the polyurethane, the reaction may be carried out without using these esterification catalysts, or a deactivation treatment may be performed after the reaction, or it may be removed by purification or the like.

  The reaction temperature of the esterification reaction is usually 150 to 250 ° C, preferably 180 to 230 ° C. For example, the reaction is easy to control if the reaction is started at 150 ° C. and the temperature is gradually raised to 230 ° C. as the reaction proceeds.

  On the other hand, the reaction pressure may be normal pressure, but it may be gradually reduced with the progress of the reaction in order to remove the by-product water out of the system and complete the reaction quickly. However, when the degree of vacuum during the reaction is insufficient, the degree of completion of the esterification reaction is lowered, and a polyester polyol having a high acid value can be obtained. On the other hand, when the pressure is excessively reduced during the reaction, not only the alcohol component is distilled out of the system and the yield is deteriorated, but also a high molecular weight polyester polyol is formed, the viscosity of the obtained polyester polyol is remarkably increased, and foaming is performed. There may be a tendency to lower the compatibility with the agent. Accordingly, the appropriate ultimate reaction pressure varies depending on the reaction temperature. For example, when the reaction temperature is 200 ° C., it is usually 1 to 50 kPa, preferably 3 to 30 kPa. Depending on the value, the type of alcohol used, and the amount used, the reaction may be carried out under conditions other than the above pressure range. Further, instead of reducing the pressure, a small amount of an organic solvent such as toluene or xylene may be used in combination, and water produced as a by-product may be removed azeotropically outside the system.

  The end point of the reaction is usually determined by the amount of unreacted carboxyl groups of the carboxylic acid used. On the other hand, in the use of rigid polyurethane foam, the presence of an acid often reduces the reactivity of the urethanization reaction with the polyisocyanate component and is not preferable, and may also affect the storage stability of the polyester polyol. is there. Therefore, it is preferable that the amount of unreacted carboxylic acid (that is, acid value) is as low as possible for the polyester polyol. The acid value is usually 5 mgKOH / g or less, preferably 3 mgKOH / g or less, more preferably 1 mgKOH / g or less. Furthermore, an acid value of 0.5 mgKOH / g or less may be desired under severe urethanization reaction conditions.

  Also, in order to keep the average number of functional groups and the hydroxyl value of the ester compound at a constant target value, it is necessary to prevent the alcohol component in an equilibrium state from being distilled out of the reaction system as much as possible during the esterification reaction during the esterification reaction. is important. If the alcohol component is distilled too much, the average number of functional groups of the ester compound will be different from that of the original product design, and the hydroxyl value will be reduced. As a result, the viscosity of the resulting polyester polyol will be remarkably high. May grow. Therefore, the amount of the alcohol component distilled out of the system during the esterification reaction is usually 5% or less, preferably 3% or less, more preferably 1% or less, based on the total alcohol components. However, the alcohol component may be distilled out beyond the above range depending on the viscosity and hydroxyl value of the target polyester polyol and the amount of the alcohol component used.

  At the start of the reaction, it is preferable to replace the space in the reaction vessel with nitrogen in order to prevent the resulting polyester polyol from being colored, and to remove dissolved oxygen in the reaction solution. Moreover, after completion | finish of reaction, you may adjust the physical property and performance of polyester polyol by distilling an unreacted alcohol component out of the system on suitable pressure-reduced conditions.

  As the reaction mode of the polyester polyol in the present invention, normal batch equipment or continuous equipment can be applied, but the reaction time is long and the viscosity of the obtained polyester polyol is considerably higher than that of the alcohol component used as a raw material. A batch reaction is preferred because it increases.

  The polyester polyol of the present invention is preferably used particularly for the production of water-foamed rigid urethane foam, and has a low viscosity, and further provides physical properties such as flame retardancy, brittleness and adhesiveness of the resulting polyurethane foam. Since it can improve, it is very useful.

  Next, production of a rigid polyurethane foam using the polyester polyol of the present invention will be described.

  In the production of rigid polyurethane foam, the polyester polyol of the present invention is usually used in the form of a liquid B after being composed with water, a catalyst, a surfactant and other auxiliary agents. A rigid polyurethane foam is obtained by mixing, foaming, and curing the A liquid and B liquid made of polyisocyanate in a short time.

  In addition to the polyester polyol of the present invention, a polyether polyol or a polyester polyol having a hydroxyl value of usually 50 to 800 and a functional group number of usually 2.0 to 8.0 can be used in combination. Two or more of these may be used in combination.

  The polyether polyol is a polymer of alkylene oxide obtained from one or more of ethylene oxide, propylene oxide, 1,2-butylene oxide, tetrahydrofuran, etc .; trifunctional such as sucrose, sorbitol, erythritol, pentaerythritol, glycerin, etc. Examples include adducts of the above alcohols with the above alkylene oxides; adducts of aliphatic amines and aromatic amines with the above alkylene oxides, and the like. In addition, known polyether polyols such as Mannich-modified polyols and polymer polyols can be used.

  Further, as the polyester polyol used in addition to the polyester polyol of the present invention, as the carboxylic acid component, aromatic or aliphatic carboxylic acid such as phthalic acid, terephthalic acid, isophthalic acid, adipic acid, succinic acid, trimellitic acid, etc. 1 or more types, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,2-butanediol, 2, 3-butanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, glycerin, trimethylolpropane, etc. ~ Trivalent Obtained by esterification reaction of one or more alcohols, hydroxyl value typically 100-500, functional groups and polyester polyols typically 1.5 to 3.0.

  In addition to the above, compounds having two or more active hydrogens in one molecule, such as alcohols such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, and glycerin, and alkanolamines such as diethanolamine and triethanolamine Can also be used together.

  The use amount of the polyester polyol of the present invention is usually 10 to 80% by weight, preferably 15 to 75% by weight, and more preferably 20 to 70% by weight as a ratio in the total polyol. When the amount of the polyester polyol used in the present invention is less than 10% by weight, the effect of lowering the viscosity of the B liquid in the present invention and the effect of improving the flame retardancy, brittleness and adhesiveness of the rigid urethane foam are reduced. On the other hand, when it exceeds 80% by weight, physical properties such as strength and dimensional stability of the rigid urethane foam may be adversely affected.

  Furthermore, it is preferable to use an aromatic polyester polyol in combination. The aromatic polyester polyol is a ratio of aromatic carboxylic acid (phthalic acid, terephthalic acid, isophthalic acid, etc.) to the total carboxylic acid component in the aforementioned polyester polyol, usually 10 mol% or more, preferably 15 mol%. As mentioned above, it is more preferably 20 mol% or more, and the hydroxyl value is usually 100 to 500, preferably 120 to 480, more preferably 140 to 460. The combined use of the aromatic polyester polyol can increase the flame retardancy of the resulting rigid urethane foam.

  Water can be used as the foaming agent. Water acts as a blowing agent by generating carbon dioxide gas by reaction with polyisocyanate. In addition, in the range that the water added more than half of the foaming action, that is, in the range that the water added more than half of the amount of the gas responsible for the foaming action is used, it is possible to use a foaming agent other than water together I can do it. Examples of foaming agents that can be used in combination include foaming agents having an ozone depletion coefficient of usually 0.8 or less, for example, HFC-based foaming agents such as HCFC-141b, HFC-245fa, and HFC-365mfc, and HC-based foaming agents such as pentane and cyclopentane. Etc. The blending amount of the foaming agent is appropriately selected depending on the density of the target rigid urethane foam.

  As a catalyst, the well-known catalyst used for manufacture of a normal polyurethane foam can be used. For example, in addition to amine-based catalysts such as triethylenediamine and N, N-dimethylhexylamine, potassium-based quaternary ammonium salts, potassium octylate, tin-based dibutyltin dilaurate, tin octylate, lead octylate, etc. Metal catalysts such as lead-based catalysts.

  The surfactant may be any of nonionic, anionic and cationic, but is preferably a nonionic surfactant, and particularly preferably a silicone surfactant.

  As other auxiliaries, various compounds can be used as additives and auxiliaries depending on the application. For example, a flame retardant and a viscosity reducer are mentioned as a typical additive. For example, chloroalkyl phosphates such as tris (beta chloroethyl) phosphate, tris (beta chloropropyl) phosphate, etc. are usually used as a flame retardant, and propylene carbonate, ethylene carbonate, tetraglyme are used as a thickener. Etc. are used. Additives and auxiliaries other than those mentioned above are not particularly limited, and if they are used for the purpose of improving physical properties and operability in ordinary resins, they can have a significant adverse effect on the urethanization reaction. It can be used as long as it is not.

  The polyisocyanate is not particularly limited as long as it is an organic compound having two or more isocyanate groups in one molecule. Examples thereof include aliphatic, alicyclic, aromatic polyisocyanates, and modified products thereof. Specific examples of the aliphatic and alicyclic polyisocyanates include hexamethylene diisocyanate and isophorone diisocyanate. Examples of the aromatic polyisocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylene polymethylene polyisocyanate and the like, and these carbodiimide modified products and prepolymers can also be used.

  A preferred polyisocyanate in the present invention is an aromatic polyisocyanate or a modified product thereof, and particularly preferred are diphenylmethane diisocyanate, polyphenylene polymethylene polyisocyanate, tolylene diisocyanate, and modified products thereof. Two or more of these may be used in combination. As the polyphenylene polymethylene polyisocyanate, those having an isocyanate group content of usually 25 to 35% by weight and a viscosity of usually 500 mPa · s (25 ° C.) or less are preferably used. Among these modified products, the carbodiimide modified product is a product in which a carbodiimide bond is introduced using a known phosphorus catalyst or the like. The prepolymer is obtained by reacting the above polyisocyanate with a polyol, leaving an isocyanate group at the terminal. In that case, the polyol component used when manufacturing a polyurethane can be used for the polyol component to be used.

  Practically, as solution A, in addition to these polyisocyanates, additives and auxiliaries may be mixed with the polyisocyanate and used depending on the application. For example, for the purpose of improving the miscibility with the B liquid, a surfactant also used in the B liquid may be used in combination as a compatibilizing agent. In this case, a nonionic surfactant is preferable, and a silicone surfactant is particularly preferable. Moreover, a flame retardant may be used together for the purpose of improving flame retardancy and adjusting viscosity. Usually, chloroalkyl phosphates such as tris (betachloroethyl) phosphate and tris (betachloropropyl) phosphate are used. Additives and auxiliaries other than those mentioned above are not particularly limited, and if they are used for the purpose of improving physical properties and operability in ordinary resins, they can have a significant adverse effect on the urethanization reaction. Otherwise, anything can be used.

  The polyurethane foam is produced by foaming and curing a composition comprising a polyol, water, a catalyst, a surfactant, other auxiliaries and a polyisocyanate. As the B liquid, water, catalyst, surfactant and other auxiliary agents are appropriately mixed with the A liquid and / or the B liquid in advance, and the two liquids are mixed and foamed and cured using an apparatus described later. Is the method. The foaming agent, water, catalyst, and surfactant are preferably mixed with the B liquid. However, in some cases, the water, the catalyst, and the surfactant are mixed with the A liquid, or the respective components are not mixed until just before the urethanization reaction. In some cases, it is handled as more than one type of raw material liquid.

  The polyurethane foam obtained by the present invention has a urethane bond, urea bond and isocyanurate bond. The isocyanurate bond is generated by trimerizing an isocyanate group with a catalyst, and can improve mechanical strength and heat resistance.

  In the present invention, the isocyanate index (number of moles of all isocyanate groups / number of moles of all active hydrogen groups × 100) is usually 70 to 400, preferably 80 to 350, and more preferably 90 to 300. When the isocyanate index is less than 70, the obtained rigid urethane foam may not have sufficient strength and may easily shrink. Moreover, when exceeding 400, the brittleness of the rigid urethane foam obtained becomes high, and there exists a tendency for adhesive strength to fall.

  The polyester polyol of the present invention can be applied to any open polyurethane, semi-open cell or closed cell rigid polyurethane foam. The rigid polyurethane foam obtained by a normal method has a ratio of closed cell ratio of about 80% or more, and generally high heat insulation performance is required for use as a heat insulating material. Therefore, a higher closed cell ratio is preferable. On the other hand, in applications where thermal insulation performance is not the highest priority, it is possible to further reduce the density and improve the dimensional stability by making some or all of the bubbles of the polyurethane foam continuous. As a method for making the bubbles continuous, for example, a method of blending a long-chain polyether polyol in which propylene oxide is added to glycerin; a metal salt of a monocarboxylic acid such as calcium stearate or calcium myristylate, for example, polyethylene or vinyl acetate And a method of blending a thermoplastic resin powder such as the above; and a method of blending a foam stabilizer that promotes the continuation of bubbles.

  In producing the polyurethane foam, any apparatus can be used as long as the liquid A and the liquid B can be uniformly mixed. For example, small mixers, low pressure or high pressure foaming machines for injection foaming, low pressure or high pressure foaming machines for slab foaming, low pressure or high pressure foaming machines for continuous lines, spraying A spray foaming machine for construction can be used. In addition, when manufacturing a polyurethane foam, each liquid temperature of A liquid and B liquid is normally adjusted to 20-60 degreeC.

  EXAMPLES Hereinafter, specific embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples unless it exceeds the gist. Unless otherwise specified, “parts” and “%” in the examples mean “parts by weight” and “% by weight”, respectively.

[Synthesis of polyester polyol]
Polyester polyols used in Examples and Comparative Examples were synthesized by known methods, and Table 1 shows the raw material composition, acid value, hydroxyl value, viscosity (25 ° C.), and average number of functional groups as polyols 1-4. Each analysis was performed according to JIS K1557 ₂₀₀₇ , and the average number of functional groups was calculated from the raw material composition.

[Premix solution preparation]
A polyol premix ("Premix-1 to 8") was prepared with the raw materials and blends shown in Table 2. Moreover, the viscosity of the polyol premix at that time was evaluated according to the following criteria (Examples 1 to 5 and Comparative Examples 1 to 3). In addition, the compounding ratio in a table | surface was shown by the weight part (pbw).

A: Low viscosity and no problem at all.
Δ: Although the viscosity is slightly higher, there is no problem in practical use.
X: Viscosity is high, and use may be limited.

  In the formulation examples in Table 2, the raw materials described in Table 3 below were used.

[Production of rigid polyurethane foam]
The rigid polyurethane foam was produced and evaluated by the following method. Table 4 shows the evaluation results as Examples 6 to 10 and Comparative Examples 4 to 6.

<Manufacturing method>
After mixing A liquid (polyisocyanate liquid) and B liquid (polyol premix) of Table 2, it poured into the injection | pouring box and made free foaming, and manufactured the rigid polyurethane foam. The polyisocyanate liquid used was polymeric MDI (“Millionate MR-200” manufactured by Nippon Polyurethane Industry Co., Ltd.), and the isocyanate index is shown in Table 4.

<Foaming conditions>
Room temperature: 23-25 ° C
Liquid temperature: 20 ° C
Stirring: 3000 rpm × 5 to 7 seconds Injection box: Wooden (200 mm × 200 mm × 200 mm) top opening Demolding time: 30 minutes after mixing

  The obtained rigid polyurethane foam was evaluated by the following method, and the results are shown in Table 4.

<Evaluation method>
(1) Core density:
It measured based on JIS A9511 ₂₀₀₃ .

(2) Self-extinguishing properties:
It measured based on JIS A9511 ₂₀₀₃ .

(3) Carbonization:
The cut urethane foam was burned, and the ratio of the weight of the remaining carbide to the weight of the original urethane foam was measured and evaluated according to the following criteria.

○: 30% by weight or more.
(Triangle | delta): It is 20 weight% or more.
X: Less than 20% by weight.

(4) Compressive strength:
It measured based on JIS A9511 ₂₀₀₃ .

(5) Dimensional stability:
The dimensional change rate (horizontal and vertical direction of foaming) after 24 hours at room temperature of the sample whose core density was measured was measured and evaluated according to the following criteria.

○: Both horizontal and vertical are less than −3%.
Δ: Both horizontal and vertical are less than −5%.
X: Either horizontal or vertical is -5% or more.

(6) Adhesiveness:
Create free form using kraft paper surface material, cut out the central part into 5x10x3cm and create a test piece. After peeling off the longitudinal direction edge part of a kraft paper surface material, it pulled in the thickness direction with the tensile tester, the peeling strength (N / 5cm) was measured, and the following references | standards evaluated.

A: 12 N / 5 cm or more.
(Triangle | delta): It is 9 N / 5cm or more.
X: Less than 9 N / 5 cm.

(7) Brittleness:
The surface and bottom of the rigid polyurethane foam were palpated and qualitatively observed, and evaluated according to the following criteria.

○: Almost no brittleness.
Δ: Some brittleness.
X: It is brittle.

  From the above results, the following is mainly clear.

(1) Comparison results between Examples 1 and 2 and Comparative Example 2:
In the case of Examples 1 and 2 in which benzoic acid, phthalic acid and fumaric acid were used as the carboxylic acid component, and polyols 1 and 2 were produced using diethylene glycol as the alcohol component, the polyol which did not use benzoic acid Compared to Comparative Example 2 containing -4, the premix has a lower viscosity.

(2) Comparison results between Examples 7 to 9 and Comparative Example 5:
In Examples 7 to 9, in which benzoic acid, phthalic acid and fumaric acid were used as the carboxylic acid component, and polyols-1 and 2 produced using diethylene glycol as the alcohol component were blended, adipic acid was used instead of fumaric acid. Compared with the comparative example 5 using the used polyol-3, the self-extinguishing property and carbonization are improving in the same isocyanate index. In Example 9 using an aromatic polyester polyol in combination, the flame retardancy is further improved.

(3) Comparison results between Examples 10 and 11 and Comparative Example 7:
In Examples 10 and 11 where benzoic acid, phthalic acid and fumaric acid were used as the carboxylic acid component, and polyol-2 produced using diethylene glycol was used as the alcohol component, adipic acid was used instead of fumaric acid. Compared to Comparative Example 7 using polyol-3, self-extinguishing properties and carbonization properties are improved at the same isocyanate index.

(4) Comparison results between Example 12 and Comparative Example 8:
In the case of Example 12 in which benzoic acid, phthalic acid and fumaric acid were used as the carboxylic acid component and polyol-2 was prepared using diethylene glycol as the alcohol component, polyol-3 using adipic acid instead of fumaric acid The self-extinguishing property is improved at the same isocyanate index as compared with Comparative Example 8 using

Claims (2)

  Polyester polyol for polyurethane foam obtained by esterification reaction of carboxylic acid component and diethylene glycol, using fumaric acid and / or maleic acid together with benzoic acid and phthalic acid as the carboxylic acid component, and The proportion of benzoic acid in the total carboxylic acid component is 10 to 70 mol%, fumaric acid and / or maleic acid is 10 to 70 mol%, and the proportion of phthalic acid is 1 mol% or more (provided that these carboxylic acids Is a polyester polyol for polyurethane foam, characterized in that the total is 100 mol%.   The polyester polyol for polyurethane foam according to claim 1, wherein the polyester polyol has a hydroxyl value of 30 to 300 and a viscosity at 25 ° C of 5000 mPa · s or less.