KR830002408B1 - Catalyst Composition for Rigid Polyurethane Foam - Google Patents

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Description

Catalyst Composition for Rigid Polyurethane Foam

The present invention relates to the production of rigid pore polyurethanes, moreover the present invention relates to novel gel catalyst compositions for the production of rigid pore polyurethanes. By using these catalyst compositions, the reaction rates of isocyanate-polyols that are not possible when using conventional catalyst combinations can be controlled extensively.

Rigid polyurethane foams can be used as insulators for structures and containers, and as insulation materials for many applications. In some of their use, such as spraying, the combination of polyfunctional isocyanates and polyols is possible and is therefore preferred because of rapid foaming and coagulation. Another use is that the composition must fill the large cavity or complex mold and therefore it is necessary to delay the onset of the isocyanate-polyol reaction until the mixture of reagents completely fills the cavity or mold. Foaming and solidification should occur quickly to minimize the time in the mold as much as possible.

When using general gel catalysts for hard polyurethane foams containing tertiary amines used alone or in admixture with organotin compounds, controlling the reaction rate of isocyanate-polyols to the extent necessary for various applications of the hard polyurethane foams impossible.

When amine is used as a catalyst, the reaction is relatively slow and the sacrifice time (the time required for the foam to reach its final height) is 3 or 4 minutes. The use of amines in combination with organotin compounds such as dibutyltin dilaurate reduces the sacrifice time in order of magnitude. The synergistic combination of these organotin compounds and amines allows the reaction mixture to solidify very quickly for any application even when the concentration of organotin compound is actually reduced to the lowest level.

It is an object of the present invention to provide a catalyst composition for hard pore polyurethanes which varies widely the reaction rate of isocyanate-polyols and the time required to initiate this reaction. This object can be achieved by using a gel catalyst composition containing antimony carboxylate, potassium carboxylate and zinc carboxylate, and such compositions can be used with amines and organotin compounds commonly used as catalysts for hardworking polyurethanes. It can be used in combination or alone.

The present invention also provides a gel catalyst composition for the production of rigid polyurethane foam, the catalyst composition mainly consisting of antimony carboxylate, potassium carboxylate, zinc carboxylate, wherein the hydrocarbyl portion of the carboxylate is Containing 1-20 carbon atoms, the antimony and potassium carboxylates each comprise 10-40% by weight of the composition and the zinc carboxylates the remaining 20-80% by weight.

The catalyst is a mixture of antimony, potassium and zinc salts of carboxylic acids containing 2-20 carbon atoms, which are used at concentrations of 0.05-10% based on the weight of the polyol, which salts are antimony, potassium, A reaction product of a basic compound of zinc with one or more carboxyl. Monocarboxylic acids are suitable for acetic acid, propionic acid, butanoic acid, pentanic acid, hexanoic acid, butanoic acid and 2-ethyl-hexanoic acid and other acids containing up to 20 carbon atoms. Unsaturated carboxylic acids derived from animal oils such as oleic acid and linoleic acid or oils such as animal fats are also used, and aromatic carboxylic acids such as benzoic acid having various substitutions in the phenyl ring, salicylic acid and naprenic acid isomers are also used. Suitable. Oxalic acid, maleic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, siberic acid, azelaic acid, sebacic acid, brassyl acid, tarpic acid, maleic acid, fumaric acid, glutamic acid, α-hydroxymuconic acid , polycarboxylic acids such as β-hydroxymucanoic acid, α-butyl-α-ethylglutamic acid, αβ-diethylsuccinic acid, isophthalic acid, terephthalic acid, hemimeltic acid and 1,4-cyclohexanedicarboxylic acid Can be used instead of monocarboxylic acid.

The above-mentioned acids can be used as a mixture containing two or more acids or used separately. Antimony, potassium and zinc compounds constituting the present catalyst composition are preferably salts of monocarboxylic acids, which preferably represent the general formulas Sb (OOCR ') ₃ , KOOCR ² and Zn (OOCR ³ ) ₂ . Wherein R ¹ , R ² and R ³ are Hamidrocarbyl and contain 1-20 carbon atoms. The term "hydrocarbyl" refers to alkyl, cycloalkyl, aryl, alkaryl and alalkyl. Most preferred is when R ¹ , R ² and R ³ are alkyl and contain 4-12 carbon atoms. Particular preference is given to acids containing eight carbon atoms arranged linearly or branched, including 2-ethyl-hexanoic acid.

The relative amounts of antimony, potassium and zinc carboxylate present in the catalyst composition of the present invention were measured by the rate required for the isocyanate-polyol reaction, and the antimony and potassium salts were 10-40% by weight, respectively. And the remaining 20-80% by weight consists of zinc salts. The composition also includes a solvent for use in three salts that are compatible with the polyol used to make the polyurethane foam. The solvent is preferably an oligomer of ethylene oxide and propylene oxide, and in particular, liquid polypropylene glycol having a molecular weight of about 300-5, 000 is a preferred kind of solvent.

Carboxylates of potassium, antimony and zinc constituting the present catalyst composition can be prepared and then combined in desired ratios. Mixtures of carboxylates can be prepared by reacting basic compounds of potassium, antimony and zinc with stoichiometric amounts of the desired carboxylic acid in suitable proportions. It is generally convenient to use hydroxides or oxides as basic compounds, and basic salts such as carbonates or bicarbonates are also suitable. The basic compounds of potassium, antimony and zinc react with or separately with the desired carboxylic acid or acids and the reaction is carried out in the presence of a chemically inert liquid medium without mixing with water such as liquid aliphatic or aromatic hydrocarbons. It is preferable. Since the reaction is exothermic, it is necessary to stir and cool the reaction mixture to avoid concentrated overheating and discoloration of the reaction product. By-product water can be removed together with a portion of the liquid hydrocarbon used as reaction medium by azeotropic distillation during the reaction, and water can also be removed into a phase which is incompatible with water after the reaction is complete.

Polyols commonly used to prepare rigid polyurethane foams include polyethers, polyesters and polyamides and alkylene glycols which are liquids having an average molecular weight of about 500-6, 000 and which contain hydroxyl groups. These polyols represent first or second active hydroxyl groups. Types of hydroxyl group-containing polyethers or polyethers include fatty acid glycerides having 300-600 hydroxyl numbers, such as castor oil, hydrogenated castor oil and "brown" natural oils.

Preferred forms of hydroxyl-terminated polyesters, polyols are, for example, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, with a molecular weight of 200-6 000 being preferred. Particularly suitable polyether forms for rigid polyurethane foams are obtained by polymerizing propylene oxide in the presence of sucrose or other compounds containing at least three hydroxyl groups. The reaction product exhibits the multifunctionality necessary to achieve the crosslinking characteristics of the rigid polyurethane foam. In proportion to containing the terminal hydroxyl groups on all of the resulting polymer chains, the hydroxyl-terminated polyester, the second type of polyol, has undergone esterification-condensation reaction of aliphatic dibasic carboxylic acids with glycols, triols or mixtures thereof. You can get it.

Dibasic carboxylic acids suitable for preparing polyesters include aliphatic and aromatic acids such as adipic acid, fumaric acid, sebacic acid and isophthalic phthalic acid. The acid reacts ethylene glycol, trimethyl with di- or polyhydroxylated compounds, such as propane or pentaethyltrotol.

The polyfunctional isocyanate used to prepare the rigid polyurethane foam refers to polyisocyanate and polyisothiocyanate, and when the reference is made in the present invention to the reaction of the polyfunctional isocyanate, G is oxygen Or sulfur, which is generally suitable for the reaction of compounds containing at least two —N═C═G groups.

Compounds belonging to this definition are polyisocyanates and polyisothiocyanates of the general formula R (NCG) _x , in which the average value of x is at least 2, preferably 2. 1-3. 0, R is alkylene, substituted alkylene, arylene, substituted arylene or other divalent hydrocarbon group optionally having one or more aryl-NCG bonds and one or more alkyl-NCG bonds. Isocyanates are suitable polyfunctional by-products obtained during the production of methylene para-phenyl diisocyanate, for example polymethylene polyphenylene para-phenyl diisocyanate. Also useful are triisocyanates obtained by reacting 3 moles of atylenediisocyanate with each mole of triol, i.e., a product formed from 3 moles of tolylene diisocyanate and 1 mole of hexanetriol. Do.

In addition to polyols, polyfunctional isocyanates and one or more of the present catalysts, the reaction mixture contains a blowing agent which boils or decomposes at the temperature of the polyol-isocyanate exothermic reaction, which solidifies and reacts the polyol-isocyanate mixture. It produces gaseous products that form bubbles during the process.

The blowing agent is preferably a halogen-containing hydrocarbon having a boiling point of about 30-90 ° C., and the precursors usually contain a surfactant, preferably from about 1-5 parts by weight per 100 parts by weight of the polyol of the siloxane-alkylene oxide copolymer It contains.

As mentioned above, the combination of potassium and zinc carboxylates and antimony carboxylates can be used in proportion to the amount of the new carboxylate salts or in particular the amount of the carboxylate salt composition used in combination with a general gel catalyst for rigid polyurethane foams. There are features that can vary the catalytic activity of these types of compositions by varying them.

These common catalysts include tertiary amines such as tricyclohexylamine, triethanol amine, N-ethyl morpholine, triethylene diamine and diethylethanolamine, with the amine being used in combination with inorganic and organotin compounds. Representative tin-containing catalysts include stannous octoate, stannous oleate, dibutyl tin dilaurate, dibutyltin dioctoate, dibutyltin dilauryl mercaptide and dibutyltin S, S'-bis (Isoxyl octyl mercaptoacetate).

These general gel catalysts are used at a concentration of 0-5 parts by weight per 100 parts of polyol.

The following examples demonstrate that the reaction rate can be broadened by using the present catalyst composition alone and in combination with amines and tin compounds to prepare rigid polyurethane foams. The examples also demonstrate that the use of generic tin and amine catalysts alone or in combination does not allow for a wide range of reaction rates. All parts and percentages indicated in the examples are by weight unless otherwise indicated.

The combinatorial time interval and polymerization initiation of all reagents are represented as "cream time" as indicated by the transition from the clear to opaque conversion of the reaction mixture, and the combinatorial time of all reagents and completion of the foam reaction is represented by "sacrificial time".

(1) 30. 4 parts polyhydroxy-base ethylene oxide-propylene oxide copolymer showing 490 hydroxyl number (using the brand Niax polyol LS-490 of Union Carbide Corporation).

(2) 0.45 parts of siloxane-oxyethylene-oxypropylene copolymer which can be used by L-5340 of Union Carbide Corporation.

(3) To a basic composition containing 9.0 parts of trichloropolomethane, add 36.7 parts of polymethylene polyphenyl isocyanate and one or more catalysts shown in the table below.

The composition referred to as catalyst A contains 20 parts of zinc bis-2-ethyl hexanoate, 15 parts of antimony tris-2-ethylhexanoate and potassium 2-ethyl-hexanoate. 50 parts of polypropylene glycol (using Polyuracol P-410 from BASF-Wyandotte Cop.) Was used as a general solvent in three salts.

^* = Contrast

The above data show that the amine is more active than Catalyst A, and the foam prepared using dibutyltin dilaurate was not completely sacrificing and not acceptable.

Synergy using the catalyst composition and amine of the present invention is evidenced by four products exhibiting a cream time of 15 seconds and a sacrifice time of 146 seconds. These times are shorter than can be achieved using amines alone.

Products containing catalyst A and dibutyltin dilaurate are achievable when the present catalyst composition is used in combination with a common organotin catalyst which does not produce satisfactory foam when the generic organotin catalyst is used alone. A wide range of creams and sacrifice times are demonstrated. This wide range uses catalyst A or a combination of tin compounds and amines and therefore cannot be achieved as these combinations exhibit a fairly high level of catalytic activity, which is comparable to the activity exhibited by the general combination of tin compounds and amines. have.

Claims (1)

The catalyst composition consists mainly of an effective amount of antimony carboxylate, potassium carboxylate and zinc carboxylate, wherein the hydrocarbyl portion of the carboxylate contains 1-20 carbon atoms and the antimony And potassium carboxylate are each composed of 10-40% by weight of the composition and zinc carboxylate is the remaining 20-80% by weight gel catalyst composition for the production of rigid polyurethane foam.