JP2019077815A - Premixed solution for manufacturing polyurethane resin and method for manufacturing polyurethane resin - Google Patents

Abstract

To improve hydrolysis resistance of polyester polyol with low hydrolysis resistance, and to provide a premixed solution for manufacturing polyurethane resin for manufacturing polyurethane resin excellent in flame retardancy.SOLUTION: There is provided a premixed solution for manufacturing polyurethane resin including a polyol, a catalyst, and a foaming agent, in which at least part of the polyol is a polyester polyol obtained by using fumaric acid and/or maleic acid as raw materials, and an amine compound of the catalyst is neutralized by a carboxylic acid to convert a salt, and at least part of the foaming agent is water.SELECTED DRAWING: None

Description

  The present invention relates to a premix liquid for polyurethane resin production and a method for producing a polyurethane resin.

  Generally, a polyurethane resin is prepared by mixing a mixture liquid (premix liquid) and a polyisocyanate liquid in which a polyol such as polyester polyol, a catalyst such as an amine compound, and a foaming agent such as water are mixed, and mixing them for a short time. It is manufactured by the method of foaming and curing.

  Flame retardancy is one of the important performances required for use in building materials which is a main application of polyurethane resins. As a general method for improving the flame retardancy, a method of adding a flame retardant such as organic phosphoric acid ester, a halogen compound and antimony oxide, and a method of using an aromatic polyester polyol such as terephthalic acid as a polyol are known. There is.

  However, the use of a large amount of the flame retardant causes a decrease in the strength of the polyurethane resin, and the amount thereof is limited. In addition, when a phthalic acid-based polyester polyol is used, the flame retardancy is improved as the aromatic ring concentration is increased, but on the other hand, there is a problem of an increase in the risk of crystallization and a deterioration in handling due to an increase in viscosity.

  Recently, in order to solve the problem of the aromatic polyester polyol described above, the polyester polyol is modified with a polyester polyol having as a raw material a carboxylic acid having an unsaturated group in the molecule such as fumaric acid and maleic acid as at least a part of polyisocyanate. It has been proposed to use the above-mentioned polyisocyanate (see Patent Document 1).

  According to the findings of the present inventor, the improvement of the flame retardancy of the polyurethane resin can be achieved also by using the above-mentioned polyester polyol as a component of the premix liquid without using it as a modifier of polyisocyanate. Although it can be performed, the rate of hydrolysis of the polyester polyol by the amine compound is faster than that of a general polyester polyol, and due to that effect, the reactivity of the premix solution decreases over time, that is, the storage stability is degraded. is there.

  As described above, polyesterpolyol using a carboxylic acid having an unsaturated group in the molecule such as fumaric acid and maleic acid as a raw material solves the problems of crystallization and high viscosity peculiar to aromatic polyesterpolyols, and further, Although it is expected that demand for the hard polyurethane resin field will be expanded because of excellent flame retardancy, there is a limitation in use due to low hydrolysis resistance in the premix liquid.

Unexamined-Japanese-Patent No. 2017-31333

  The present invention has been made in view of the above circumstances, and an object thereof is to manufacture a polyurethane resin for improving the hydrolyzability of polyester polyol having low hydrolysis resistance and for producing a polyurethane resin excellent in flame retardancy. The present invention is to provide a premix solution. Another object of the present invention is to provide a method for producing a polyurethane resin using the above-mentioned premix solution.

  As a result of intensive investigations, the inventors of the present invention have found that, in order to suppress hydrolysis in a premixed solution of a polyester polyol starting from fumaric acid and / or maleic acid, a large number of amine compounds of the catalyst responsible for hydrolysis are used. It was found that it was effective to neutralize with a carboxylic acid and convert it to a salt once.

  The present invention has been completed based on the above findings, and the gist thereof is a premix liquid for producing a polyurethane resin containing a polyol, a catalyst and a foaming agent, wherein at least a part of the polyol is fumaric acid and / or Or polyester polyol starting from maleic acid, wherein the amine compound of the catalyst is neutralized with carboxylic acid and converted to a salt, and at least a part of the foaming agent is water, for producing polyurethane resin Premix solution.

  Another subject matter of the present invention resides in a method for producing a polyurethane resin, which comprises mixing the above-mentioned premix solution with a polyisocyanate solution.

  According to the present invention, it is possible to improve the hydrolysis resistance of the polyester polyol having low hydrolysis resistance in the premix solution. Also. It is possible to provide a polyurethane resin having excellent flame retardancy.

  Hereinafter, the present invention will be described in detail.

[Premix solution]
For the preparation of the premix liquid, polyesterpolyol derived from fumaric acid and / or maleic acid, an amine compound and carboxylic acid and / or their salts, a foaming agent and the like are used. On the other hand, the premix solution does not necessarily have to be one type, and two or more types of premix solutions can be combined, and it is also possible to use the premix solution and one or more types of raw materials in combination. The components of the premix solution will be described below.

(Polyol)
In the present invention, it is essential to use a polyester polyol starting from fumaric acid and / or maleic acid. The content of fumaric acid and / or maleic acid is at least 10 mol% with respect to all carboxylic acid components. Such polyester polyols are described in JP-A-2017-31333. Also, known polyols generally used for the production of polyurethane resins can be used in combination.

  As polyester polyols which can be used in combination, for example, in the carboxylic acid component, as aliphatic polyvalent carboxylic acid, oxalic acid, malonic acid, succinic acid, fumaric acid, glutaric acid, adipic acid, suberic acid, sebacic acid, azelaic acid, maleic acid And acids and their ester derivatives. Further, examples of aromatic polyvalent carboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, and ester derivatives thereof. One or more of these may be used in combination.

  In the alcohol component, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl 1,5-pentanediol, propylene glycol, polyethylene glycol, polypropylene Examples thereof include glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol and the like, and one or more of them may be used in combination.

  Examples of polyether polyols include ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl 1,5-pentanediol, propylene glycol, glycerin, One kind of compound having two or more active hydrogens such as polyhydric alcohols such as trimethylol propane, pentaerythritol and sorbitol, sugar based alcohols such as glucose and fructose, and amines such as ethylene diamine, propylene diamine and diethylene triamine Or what is obtained by addition-polymerizing two or more types with one or more types of monomers, such as ethylene oxide and a propylene oxide, as an initiator is mentioned. Moreover, what disperse | distributed the polymer of vinyl compounds, such as an acrylonitrile and styrene, to polyether polyol as a polymer polyol is mentioned.

  The amount of the polyester polyol based on fumaric acid and / or maleic acid, which is an essential component of the present invention, is usually 10 parts by weight or more, preferably 30 parts by weight or more, more preferably 50 parts by weight or more based on the polyol component. It is. On the other hand, the upper limit amount is not particularly limited, and the entire polyol component may be a polyester polyol having fumaric acid and / or maleic acid as a raw material.

(catalyst)
As the catalyst, known amine compounds used in the production of conventional polyurethane foams can be used. For example, tertiary amine compounds such as N, N-dimethylaminoethoxyethanol, N, N, N ', N'-tetramethylhexanediamine, N, N, N', N ", N" -pentamethyldiethylene triamine, etc. It can be mentioned. Other catalysts include: imidazole compounds such as 1-methylimidazole and 1-isobutyl-2-methylimidazole; organometallic compounds such as dibutyltin dilaurate, lead octylate and potassium octylate; and quaternary ammonium compounds It can be mentioned. The compounding amount of the catalyst is preferably combined according to the reactivity, physical properties and molding method.

  As a carboxylic acid used in order to neutralize the amine compound which is a catalyst, monohydric carboxylic acid, polyhydric carboxylic acid, etc. are mentioned. Examples of the monovalent carboxylic acid include formic acid, acetic acid, hexanoic acid, heptanoic acid, octanoic acid and 2-ethylhexanoic acid. Examples of polyvalent carboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid and malic acid for divalent aliphatic carboxylic acids, and phthalic acid and isophthalic acid for aromatic carboxylic acids. And terephthalic acid. Further, trimellitic acid, pyromellitic acid, citric acid or the like of trivalent carboxylic acid can be used. Among them, it is preferable to use a polyvalent carboxylic acid from the viewpoint of stability of salt, dissociation rate and low corrosiveness, and specifically, it contains at least one selected from succinic acid, glutaric acid and adipic acid Is preferred.

  The amount of the carboxylic acid used is usually 0.1 to 5.0 moles, preferably 0.3 to 3.0 moles, more preferably 0.5 to 1 mole, relative to the mass of the N atom of the amine compound catalyst. .5 times mole. When the amount used is less than 0.1 times the molar amount, neutralization with the catalyst is insufficient and the effect of suppressing hydrolysis is low. On the other hand, if it exceeds 5.0 moles, reaction inhibition occurs at the time of urethanization, and physical properties decrease due to poor curing.

  The carboxylic acid may be added directly to the premix solution, but from the viewpoint of solubility in the premix solution, preferably the catalyst is mixed with water and / or glycol and added as a solution preferable.

(Foaming agent)
In the production of the polyurethane resin according to the present invention, water acts as a blowing agent by generating carbon dioxide gas by reaction with polyisocyanate. This also includes the water content in raw materials such as polyols. Other foaming agents include, for example, hydrohydrocarbons such as 1,1,1,3,3-pentafluoropropane (HFC-245fa) and 1,1,1,3,3-pentafluorobutane (HFC-365mfc) Fluorocarbon blowing agents, hydrocarbon blowing agents such as pentane and cyclopentane, trans-1-chloro-3,3,3-trifluoro-1-propene (HFO-1234ze), cis-1,1,1,4, Examples thereof include hydrofluoroolefin-based foaming agents such as 4,4-hexafluoro-2-butene (HFO-1336mzz), carbon dioxide gas, and the like.

(Auxiliary agent)
In the production of the polyurethane resin according to the invention, assistants can be used depending on the application. As the auxiliaries, there may be mentioned foam stabilizers, flame retardants, crosslinking agents, solvents and the like.

  As the foam stabilizer, for example, nonionic surfactants such as organic siloxane-polyoxyalkylene copolymer, silicone-grease copolymer and the like can be used, and the amount thereof used is 100 parts by weight of polyol. The amount is usually 0.1 to 20 parts by weight, preferably 0.3 to 10 parts by weight, and more preferably 0.5 to 5 parts by weight. These can be used alone or in combination of two or more.

  As the flame retardant, for example, organic phosphoric acid ester flame retardants such as halogenated alkyl ester of phosphoric acid, alkyl phosphoric acid ester, aryl phosphoric acid ester, phosphonic acid ester and the like can be used, and specifically, tris (β -Chloroethyl) phosphate, tris (β-chloropropyl) phosphate and the like can be used. The amount of the flame retardant to be used is usually 1 to 100 parts, preferably 3 to 50 parts by weight, more preferably 5 to 30 parts by weight, per 100 parts by weight of the polyol. These can be used alone or in combination of two or more.

  Examples of the crosslinking agent include trimethylolpropane, glycerin, pentaerythritol, triethanolamine and the like. Further, as a solvent, γ-butyrolactone, polycarbonate, propylene glycol monomethyl ether acetate and the like can be used. The auxiliary agents other than those described above are not particularly limited, and can be used in the range in which the object of the present invention is not inhibited.

[Method of producing polyurethane resin]
(Polyisocyanate)
Known polyisocyanates can be used as the polyisocyanate. For example, hexamethylene diisocyanate and the like for aliphatics, toluene diisocyanate and 4,4'-diphenylmethane isocyanate and the like for aromatics, dicyclohexyl diisocyanate and isophorone diisocyanate and the like for alicyclics, and derivatives and mixtures thereof can be mentioned. These can be used alone or in combination of two or more.

  Preferred polyisocyanates are mixtures of aromatic polyisocyanates 2,4-toluene diisocyanate and 2,6-tolylene diisocyanate, and polymers of 4,4'-diphenylmethane isocyanate.

  In the present invention, the amount of polyisocyanate used is not particularly limited, but in consideration of foam strength, isocyanate index = [isocyanate group (number of moles) / active hydrogen group such as polyol, water, etc. (number of moles)] As * 100, it is 50-800 normally, Preferably it is 80-600, More preferably, it is 100-400.

In the present invention, the density of the polyurethane foam is represented by the core density of free foam and is usually 10 to 60 kg / m ³ , preferably 15 to 55 kg / m ³ , more preferably 20 to 50 kg / m ³ . If the density is less than 10 kg / m ³ , the resulting polyurethane foam does not have sufficient flame retardancy and mechanical strength, and if it exceeds 60 kg / m ³ , the cost is high.

  In the present invention, the premix solution and the polyisocyanate solution are stirred at high speed, foamed and cured to produce a rigid polyurethane resin. At this time, the polyvalent carboxylic acid salt of the amine compound in the premix solution is easily thermally decomposed to return to the amine compound acting as a urethanization catalyst, whereby the urethanization reaction is smoothly performed. As the foaming machine, high pressure and low pressure foaming machines for injection foaming, high pressure and low pressure foaming machines for slab foaming, high pressure and low pressure foaming machines for laminate foaming, and a spray foaming machine can be used.

  EXAMPLES Hereinafter, specific embodiments of the present invention will be described in more detail by way of examples, but the present invention is not limited by these examples as long as the gist thereof is not exceeded.

(Hydrolysis inhibitory effect of polyvalent carboxylate)
A premix solution was prepared with the formulation shown in Table 1 in Examples 1 to 3 and Comparative Example 1. Examples 1 to 3 were prepared by adding an aqueous solution obtained by mixing a predetermined amount of carboxylic acid, an amine compound, and water to a premix solution containing other raw materials. The obtained premix solution was stored at 60 ° C./42 hours. After storage, use Polymeric М DI (“Millionate М R-200” made by Tosoh Corp.) as a polyisocyanate liquid, measure two liquids in a predetermined amount poly cup, mix at high speed with laboratory mixer under 15 ° C conditions, and make wooden box (200 mm , Poured into 200 mm, 200 mm) to make a free form.

  The CT (cream time), GT (gel time), and 98% RT in free foaming were measured, and the evaluation was made based on the difference in reaction time before and after storage. The delay rates shown in Table 1 are values derived from after / before storage of the measurement item.

From the above results, the following are mainly evident.

  Comparative Example 1 using free amine compound (Polycat-37: N, N-dimethylaminoethoxyethanol) not converted to a salt with polyvalent carboxylic acid in Table 1 has a reaction delay rate of 1 after storage due to hydrolysis. Although it rose from 0.5 to 1.8, Examples 1 to 3 using the amine salt obtained by neutralization with polyvalent carboxylic acid (1 mole relative to the nitrogen atom of Polycat-37) were stored. The late reaction rate was 1.1 to 1.3, and almost no late reaction was observed.

(Hydrolysis suppression effect by added number of polyvalent carboxylate)
A premix solution was prepared with the formulation shown in Table 2 in Examples 4 to 5 and Comparative Example 2. In Examples 4 to 5, an aqueous solution in which a predetermined amount of carboxylic acid, an amine compound, and water were mixed was added to a premix solution containing other raw materials. The obtained premix solution was stored at 60 ° C./42 hours. After storage, use Polymeric М DI (“Millionate М R-200” made by Tosoh Corp.) as a polyisocyanate liquid, measure two liquids in a predetermined amount poly cup, mix at high speed with laboratory mixer under 15 ° C conditions, and make wooden box (200 mm , Poured into 200 mm, 200 mm) to make a free form.

  The CT (cream time), GT (gel time), and 98% RT in free foaming were measured, and the evaluation was made based on the difference in reaction time before and after storage. The delay rates shown in Table 2 are values derived from after / before storage of the measurement item.

  From the above results, the following are mainly evident.

  Comparative Example 2 using free amine compound (Kaolyzer No. 3: N, N, N ′, N ′ ′, N ′ ′, N ′ ′-pentamethyldiethylene triamine) not converted to a salt with polyvalent carboxylic acid in Table 2 is While the reaction delay rate by hydrolysis after storage increased to 1.5 to 1.9, the amine compound was neutralized with polyvalent carboxylic acid (1 mole added to the nitrogen atom of Kaulyzer No. 3) The reaction delay rate after storage was about 1.1 to 1.5, and almost no reaction delay was observed. Further, Example 5 in which the polyvalent carboxylic acid is added more than that in Example 4 (3 moles per 1 mol of nitrogen atom of Kaulyzer No. 3) has a reaction delay ratio of 1.0 to 1.1, and is further hydrolyzed. The reduction effect of

Claims (5)

  A premix liquid for producing a polyurethane resin comprising a polyol, a catalyst and a foaming agent, wherein at least a part of the polyol is a polyester polyol having fumaric acid and / or maleic acid as a raw material, and an amine compound of the catalyst is a carboxylic acid A premix liquid for producing a polyurethane resin, which is neutralized to be converted to a salt, and at least a part of the foaming agent is water.   The premix solution according to claim 1, wherein the carboxylic acid is a divalent or trivalent polyvalent carboxylic acid.   The premix liquid according to claim 2, wherein the carboxylic acid is at least one selected from the group of succinic acid, glutaric acid and adipic acid.   The premix solution according to any one of claims 1 to 3, wherein the number of addition parts of the carboxylic acid is 0.1 to 5.0 times the molar amount of the nitrogen atom of the catalyst.   The manufacturing method of the polyurethane resin characterized by mixing the premix liquid and polyisocyanate liquid in any one of Claims 1-4.