JPS584050B2 - Method for producing modified polyisocyanurate foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing heat-resistant, flame-resistant rigid foams having isocyanurate rings during molecular production.

More specifically, the present invention relates to a simple and inexpensive method for producing a modifier having isocyanate trimerization catalytic activity and a method for producing a modified polyisocyanurate foam using the modifier.

In the production of modified polyisocyanurate foams, the selection of modifiers and isocyanate trimerization catalysts are important factors that govern the production process and the performance of the foams.

BACKGROUND ART Conventionally, a method for producing a urethane-modified polyisocyanurate foam by reacting a polyisocyanate and a polyol (eg, polyether, polyester, etc.) in the presence of an isocyanate trimerization catalyst is well known.

(For example, Special Publication No. 46-2269, Special Publication No. 46-4238
6, Japanese Patent Publication No. 47-28919, etc.) Various incyanate trimerization catalysts are also known.

(For example, Special Publication No. 35-2799, Special Publication No. 40-583
8, Special Publication No. 44-16669, Special Publication No. 46-13257
, Special Publication No. 46-15298, Special Publication No. 46-25017,
Special Publication Showa 46-31531. Special Publication No. 46-33577, Special Publication No. 46-37503, Special Publication No. 46-41393, Special Publication No. 46-41610, Special Publication No. 47-36038, Special Publication No. 48-35720, No. 47-2949
1. Japanese Patent Publication No. 48-49898, Japanese Patent Application Publication No. 48-81996
etc.) Among these catalysts, carboxylic acid salts are commonly used from the viewpoint of price, catalytic activity, odor, etc.
Since these are solids, they must be liquefied before use.

Furthermore, since the production of modified polyisocyanurate foam is usually handled as a bipartite system, the isocyanate trimerization catalyst must be mixed with a modifier, a surfactant, a blowing agent, etc. in advance to form a homogeneous solution.

However, salts are generally difficult to dissolve in polyols, and blowing agents (for example, trichloropunoleolomethane, etc.)
Furthermore, it is difficult to dissolve and hardly dissolves.

Therefore, as a method to improve these problems, for example, long-chain fatty acids and potassium hydroxide are reacted by heating in a mixture consisting of high-molecular-weight polyols and low-molecular-weight glycols, and the by-product water is removed from the system under reduced pressure. How to make it distillate (
JP-A-48-39390), a method for solubilizing potassium acetate with a specific polyol (JP-A-48-8199)
6), A method for increasing the compatibility with polyols using an alkali metal salt of a β-alanine derivative (Japanese Unexamined Patent Publication No. 50-4
198) and a method for efficiently solubilizing crude polyol by neutralizing it with a weak acid (Japanese Patent Application Laid-Open No. 51-6299).

However, these methods cannot avoid disadvantages such as complicating the manufacturing process, limiting the polyol structure that can be used (thereby limiting the performance of the foam), and limiting the catalyst concentration.

The present inventors have conducted intensive research to improve the above-mentioned drawbacks, and as a result, they have provided the present invention.

That is, in a method for producing a modified polyisocyanurate foam, a nitrogen-containing carboxylic acid obtained by reacting an organic amine compound having one or more aminic active hydrogens in the molecule with a dicarboxylic acid anhydride is reacted with the activity of the terminal hydroxyl group. A mixed solution of a nitrogen-containing alkali metal carboxylic acid salt and a polyether polyol obtained by treatment with a polyether polyol in which a portion of hydrogen has been replaced with an alkali metal is used as a modifier with incyanate trimerization catalytic activity. A method for producing a modified polyisocyanurate foam, and a method for producing a modified polyisocyanurate foam, characterized in that an organic amine compound having one or more aminic active hydrogens in the molecule and a dicarboxylic acid anhydride are reacted. The nitrogen-containing carboxylic acid obtained is treated with a polyether polyol in which a portion of the active hydrogen of the terminal hydroxyl group has been replaced with an alkali metal and an alkali metal hydroxide,
A modified polyisocyanate characterized in that the resulting mixed solution of an alkali metal salt of a nitrogen-containing carboxylic acid, a polyether polyol, and water is used as it is or after dehydration treatment as a modifier having incyanate trimerization catalytic activity. This is a method for producing nurate foam.

Examples of organic amine compounds having one or more aminic active hydrogens in the molecule (hereinafter referred to as organic amine compounds) used in the present invention include aliphatic primary amines such as methylinamine, ethylamine, probylamine, butylamine, dimethyl amines, aliphatic secondary amines such as diethylamine, dipropylamine, and dibutylamine; alicyclic amines such as cyclopropylamine, cyclobutylamine, and cyclohexylamine; aromatic amines such as aniline, amine toluene, and naphthylamine; Aralkylamines such as penzylamine and dibenzylamine, morpholine, pyrrolidine, heterocyclic amines such as pipecoline, alkanolamines such as monoethanolamine, diethanolamine, monoisopropanolamine, diisopropanolamine, ethylenediamine, propylene diamine, butylene diamine , hexamethylenediamine, diethylenetriamine, triethylenetetramine, piperazine, N-aminoethylpiperazine, phenylenediamine, toluenediamine, cyphenylmethanediamine, etc., and alkylene oxide adducts of the above amines (however, alkylene oxide adducts of the above amines) (The amount is within the range where one or more aminic active hydrogen atoms exist in the molecule)
etc., and may be used alone or in combination of two or more.

In the present invention, dicarboxylic acid anhydrides used include, for example, saturated aliphatic dicarboxylic anhydrides such as succinic anhydride and glutaric anhydride; unsaturated aliphatic dicarboxylic acid anhydrides such as fumaric anhydride and maleic anhydride; Aromatic dicarboxylic acid anhydrides such as phthalic anhydride may be used alone or in combination of two or more.

In the present invention, the reason why a nitrogen-containing carboxylic acid obtained by reacting an organic amine compound and a dicarboxylic anhydride is used as a carboxylic acid component is as follows.

The reaction between the aminic active hydrogen of an organic amine compound and a carboxylic acid anhydride is very easy compared to the reaction of other active hydrogen compounds, such as the reaction of a hydroxyl group with active hydrogen, and Various carboxylic acids can be easily obtained by selecting , and the resulting alkali metal salts of nitrogen-containing carboxylic acids have significantly increased compatibility with polyether polyols and blowing agents due to the action of amide or amine nitrogen atoms. It is to be.

Furthermore, the reason for using dicarboxylic anhydride as the carboxylic anhydride is that when monocarboxylic acid anhydride is used, the same mole of monocarboxylic acid itself is produced as a by-product during the reaction with the amine compound, but nitrogen-containing carboxylic acid is not produced. This is because, if a dianhydride such as pyromellitic acid is used, the amine compound may become polymerized depending on the type of the amine compound, which does not meet the purpose of the present invention.

Next, for the polyether polyol in which a part of the active hydrogen of the terminal hydroxyl group is substituted with an alkali metal used in the present invention, for example, an organic compound having at least two or more active hydrogens (hereinafter referred to as an initiator) is added with an alkali as a catalyst. A polyether polyol containing a catalyst (hereinafter referred to as crude polyether polyol) obtained by adding a metal hydroxide, heating and depressurizing it, and then addition-polymerizing an alkylene oxide; Polyether polyol obtained by heating and reducing pressure after additional addition of
After adding an alkali metal hydroxide to the polyether polyol (hereinafter referred to as purified polyether polyol) from which the catalyst has been purified and removed from the crude polyether polyol,
Examples include polyether polyols obtained by heat-reduction treatment and mixtures thereof, but crude polyether polyols are most preferred.

Examples of initiators for polyether polyols include ethylene glycol, propylene glycol, glycerin,
Low-molecular polyhydric alcohols such as trimethylolpropane, pentaerythritol, sorbitol, and sucrose;
Alkanolamines such as monoethanolamine, diethanolanamine, and triethanolamine; aliphatic polyamines such as ethylenediamine, diethylenetriamine, and triethylenetetraamine; aromatic compounds such as tolylenediamine, 4,4'-diphenylmethanediamine, and phenylenediamine; Examples include aromatic polyhydric alcohols such as polyamines, bisphenol A1, and novolac resins.

Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, etc., and one or more of these are added to an initiator in the form of a random or block copolymer.

The polyether polyol of the present invention in which a part of the active hydrogen of the terminal hydroxyl group is substituted with an alkali metal usually has a hydroxyl value of 25 to 1000, preferably 100 to 600.

Furthermore, examples of the alkali metal hydroxides include hydroxides of lithium, sodium, potassium, and the like.

The reason for using a polyether polyol in which a part of the active hydrogen of the terminal hydroxyl group is substituted with an alkali metal as the alkali metal supply source to the nitrogen-containing carboxylic acid is as follows.

A general method for producing polyether polyol is to purify and remove the catalyst from the above-mentioned crude polyether polyol, and the crude polyether polyol is produced as a polyether polyol in which a portion of the active hydrogen of the terminal hydroxyl group has been replaced with an alkali metal. Polyol can be suitably used.

The fact that a modifier with isocyanate trimerization catalytic activity can be easily obtained from this crude polyether polyol and nitrogen-containing carboxylic acid means that the purification process of polyether polyol can be omitted, and alkylene, which has traditionally been removed and disposed of, can be easily obtained. This method has the advantage of killing two birds with one stone in that the oxide polymerization catalyst can be effectively used as an essential component of the isocyanate trimerization catalyst.

Furthermore, if the amount of alkali metal contained in the crude polyether polyol is insufficient, a necessary amount of an alkali metal hydroxide or an aqueous solution of an alkali metal hydroxide may be added.

If it is acceptable for moisture to be present during foaming, there is no need for dehydration; otherwise, moisture may be removed by heating and reducing pressure.

The quantitative relationship between the organic amine compound and the dicarboxylic anhydride used in the present invention is such that 1 mol or more of the dicarboxylic anhydride per 1 mol of the organic amine compound, and 1 mol or more of the primary and/or secondary amine in the organic amine compound. It is preferably 1 mol or less of dicarboxylic acid anhydride per mol.

When the nitrogen-containing carboxylic acid has a high viscosity or a high melting point, the reaction may be carried out in the presence of a purified polyether polyol as a viscosity reducing agent.

Reaction conditions are 30-150°C, preferably 60-120°C
It takes about 1 to 3 hours.

In addition, the quantitative relationship between nitrogen-containing carboxylic acid and alkali metal is that the carboxyl group is 0.1 to 1 mole of alkali metal.
1.5, preferably 0.8 to 1,2 mol, and the heating conditions are 30 to 150°C, preferably 60 to 120°C, and 1 to 2 mol.
It takes about 3 hours.

When producing a modified polyisocyanurate foam using the mixed solution of the nitrogen-containing alkali metal carboxylic acid salt and polyether polycal according to the present invention as a modifier having isocyanate trimerization catalytic activity, the equivalent ratio is generally 2.
It is preferable to react with the above polyisocyanate, but if heat resistance, flame resistance, etc. are not strictly required,
A good foam can be obtained even when reacting with a polyisocyanate having an equivalent ratio of 2 or less.

That is, a good foam can be obtained even when used as a polyol having urethanization catalyst activity for so-called rigid urethane foams, which reacts at an equivalent ratio of about 0.8 to 1.2.

When reacting with polyisocyanate at an equivalent ratio of 2 or less,
In addition to the modifier according to the present invention, other known isocyanate trimerization catalysts and urethanization catalysts, and various known active hydrogen compounds as modifiers can also be used in combination, if necessary.

Next, as the polyisocyanate used in producing the polyisocyanurate foam of the present invention, for example, 4,4'-diphenylmethane diisocyanate crude product (hereinafter referred to as crude MDI), polymethylene polyphenylisocyanate (PAPI), Tolylene diisocyanate crude product (crude TDM), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene diisocyanate, xylene diisocyanate,
Examples include polyisocyanates such as hexamethylene diisocyanate and inphorone diisocyanate, mixtures thereof, and prepolymers of these polyisocyanates and polyols.

As the blowing agent, for example, trichloromonofluoromethane (F-11), dichlorodifluoromethane (F-12)
and low-boiling organic solvents such as methylene chloride, water, nitroethane, formamide, urea, boric acid, borax, and the like.

Further, examples of the surfactant include siloxane-oxyalkylene copolymer (hereinafter referred to as silicone oil), organosoborisiloxane, oxyethylated alkylphenol, oxyethylated higher alcohol, and ethylene oxide-propylene oxide block polymer.

Other additives include, if necessary, known flame retardants,
Fillers, colorants, etc. can also be used.

Next, the modified polyisocyanurate foam is produced by a one-shot molding method or a prepolymer method using known methods such as slab foaming, injection foaming (conventional and cross methods), spray foaming, and continuous lamination foaming. .

The present invention is directed to the production of modified polyisocyanurate foam, which has heat insulation properties comparable to rigid polyurethane foams, which have the best heat insulation properties, and can improve heat resistance and flame resistance, which are disadvantages of rigid polyurethane foams. Regarding isocyanate trimerization catalysts and modifiers, which are considered to be important points, we solved the drawbacks of conventional methods, such as complicating the manufacturing process, increasing costs, poor system compatibility, odor, and limitations on modifiers. The modified polyisocyanurate is inexpensive, has a simplified manufacturing process, has good system compatibility, is odorless, and allows the molecular structure of the modifying agent polyether polyol to be freely selected according to the purpose. It provides a form.

In order to explain the present invention more specifically, Examples are shown below, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Example 1 92 parts by weight of synthetic glycerin, 85% potassium hydroxide5.
94 parts by weight were charged into an autoclave purged with nitrogen gas, and the pressure was reduced to 5 mmHg at 130°C.

Next, 195.7 parts by weight of propylene oxide and then 48.9 parts by weight of ethylene oxide were reacted at 10.0 to 110°C for a total of about 3 hours to obtain a crude polyether polyol as a transparent viscous liquid. .

Example 2 74 parts by weight of di-n-butylamine was placed in a 300cc four-necked flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube, and 100 parts by weight of succinic anhydride was added while introducing nitrogen and keeping the temperature below 50°C. Thereafter, the mixture was heated and stirred at 90 to 100° C. for 1 hour to obtain a nitrogen-containing carboxylic acid in the form of wax at room temperature.

Next, a
14 parts by weight of nitrogen-containing carboxylic acid and 3 parts of the crude polyether polyol obtained in Example-1 were placed in a 00cc four-piece flask.
00 parts by weight was charged and reacted at 90 to 100° C. for 1 hour under nitrogen introduction to obtain a mixed solution of a nitrogen-containing alkali metal carboxylate and polyether polyol as a pale yellow viscous liquid.

Example 3 16.5 parts by weight of a nitrogen-containing carboxylic acid, which is a light yellow viscous liquid, obtained in the same manner as in Example 2 using 105 parts by weight of diethanolamine instead of di-n-butylamine and Example 3 30 of the rice-based polyether polyol obtained in -1
50 parts by weight equipped with a stirrer, thermometer, and nitrogen inlet tube
Pour into a 0CC four-necked flask and introduce nitrogen at 90 to 100
The mixture was reacted at .degree. C. for 1 hour to obtain a mixed solution of nitrogen-containing alkali metal carboxylic acid and polyether polyol as a pale yellow viscous liquid.

Example 4 60 parts by weight of each mixed solution of the alkali metal salt of nitrogen-containing carboxylic acid and polyether polyol of Examples-2 and -3, 2 parts by weight of silicone oil (DKS Silicone D-332; manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) part, trichlorofluoromethane (
Weigh out 60 parts by weight of Daiflon R-11U (manufactured by Daikin Industries, Ltd.) into a 1 liter polyethylene handle beaker, and
The temperature was adjusted to 0°C.

Then, 24° C. of crude MDI (Millionate MR-100; manufactured by Nippon Polyurethane Industries, Ltd.), which had been adjusted to 20° C.
After quickly adding 0 parts by weight and stirring and mixing vigorously for 5 seconds using a lab mixer, the mixture was poured into a wooden box with a polyethylene square bag set inside.

The mixed liquid was rapidly foamed and solidified, and a rigid foam having the following properties was obtained.

Claims (1)

[Claims] 1. In a method for producing a modified polyisocyanurate foam, a nitrogen-containing carboxylic acid obtained by reacting an organic amine compound having one or more aminic active hydrogens in the molecule with a dicarboxylic acid anhydride is used. , a mixed solution of a nitrogen-containing alkali metal salt of a nitrogen-containing carboxylic acid and a polyether polyol was treated with a polyether polyol in which a part of the active hydrogen of the terminal hydroxyl group was substituted with an alkali metal, and the resulting mixed solution was treated with a polyether polyol having an isocyanate trimerization catalytic activity. A method for producing a modified polyisocyanurate foam, characterized in that it is used as a modifier. 2. In the method for producing modified polyisocyanurate foam, a nitrogen-containing carboxylic acid obtained by reacting an organic amine compound having one or more aminic active hydrogens in the molecule with a dicarboxylic acid anhydride, A mixed solution of a nitrogen-containing alkali metal salt of a nitrogen-containing carboxylic acid, a polyether polyol, and water is treated as it is or after dehydration treatment. A method for producing a modified polyisocyanurate foam, which is subsequently used as a modifier having isocyanate trimerization catalytic activity. 3. The method for producing a modified polyisocyanurate foam according to claim 2, wherein an aqueous alkali metal hydroxide solution is used as the alkali metal hydroxide.