JPS606717A - Polyurethane foaming catalyst - Google Patents

Abstract

PURPOSE:A foaming catalyst having a persistency and, useful as a polyurethane foaming catalyst, obtained by mixing pentamethyldiethylenetriamine with a monobasic organic carboxylic acid, water, and a hydroxyl group-containing organic solvent. CONSTITUTION:The purpose polyurethane foaming catalyst is prepared by mixing 1mol of N, N, N', N'', N''-pentamethyl-diethylenetriamine, obtained by permethylating diethylenetriamine, with 0.5-2mol of a monobasic organic carboxylic acid (e.g., formic acid), water, and an organic solvent having 2-4 hydroxyl groups (e.g., dipropylene glycol). This foaming catalyst can be used suitably in the production of a polyurethane foam by reacting an organic polyisocyanate with a polyol in the presence of a blowing agent and has a characteristic property that its activity is weak in the initial stage but increases with the progress of foaming.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to polycrethane foam catalysts having retardation properties useful as foam catalysts. For more details, % NI Nt ” I N
#IN#-pentamethyldiethylenetriamine (hereinafter referred to as
The present invention relates to a polyurethane foaming catalyst characterized in that it consists of PMDFtTA (abbreviated as PMDFtTA), a monobasic organic carboxylic acid, water, and an organic solvent having 2 to 4 hydroxyl groups.

Polyurethane foams are produced by reacting organic polyisocyanates and polyols in the presence of blowing agents and catalysts. Conventionally, many organic tin compounds and tertiary amine compounds have been known as polyurethane foaming catalysts, and they are widely used industrially either alone or in combination.

In recent years, with the remarkable development of the polyurethane industry, polyurethane foams have become larger and more complicated in shape are required. On the other hand, in order to increase the productivity of polyurethane foam, it is required to shorten the time required to remove it from the mold as much as possible.

In response to the above requirements, using conventional organotin compounds and tertiary amine compounds causes various inconveniences. As soon as they are mixed, a foaming reaction occurs and the viscosity increases, resulting in problems such as poor handling of the mixed solution and the inability of the solution to flow to every corner of a large mold. On the other hand, if an attempt is made to solve these problems, the time taken to demold the polyurethane foam becomes longer, resulting in problems such as an inability to increase productivity. In order to solve these problems, it has been desired to develop a so-called delayed catalyst, which has a weak initial activity as a polyurethane foaming catalyst and whose activity increases as foaming progresses.

As a slow-acting catalyst, JP-A-54-15069
Organic carboxylic acid salts of quintic amines are known as described in Publication No. 7 9% and Publication No. 57-56491. Organic carboxylic acid salts of tertiary amines do not exhibit their original activity at the initial stage of polyurethane foam formation reaction because the 5th class amine is blocked by organic carboxylic acid, but as the foam formation reaction progresses, the reaction temperature increases. Since the tertiary amine salt is thermally dissociated by the rise, the catalytic activity inherent to the tertiary amine is expressed. Examples of delayed catalysts with such properties include triethylenediamine and bis-(
Salts of tertiary amines such as dimethylaminoethyl) ether and organic carboxylic acids such as formic acid and acetic acid are known. However, these retarding catalysts are expensive and have a low pH, so they tend to corrode the materials of the catalyst mixing tank and the foaming machine, and there are problems in that they do not exhibit an effective retarding effect. Therefore,
In view of these circumstances, the present inventors investigated retarded catalysts and found that PMDB' is useful as a tertiary amine catalyst.
It has been found that when an organic carboxylic acid is blended with TA, an effective delaying effect can be expected.

However, when an attempt is made to produce a retarded catalyst by blending an organic carboxylic acid with PMDITA, it forms a solid salt that is difficult to bathe in ordinary organic solvents, or it separates into two phases. For this reason, it is not possible to incorporate sufficient organic carboxylic acid into PMDETA, making it impossible to develop effective retardation properties, and as a result of using a large amount of solvent to make a homogeneous catalyst solution, PM
DII! There are problems in that the iTA concentration cannot be increased and the solvent deteriorates various physical properties of the polyurethane foam.

In view of the above circumstances, the present inventors have conducted extensive studies on polyurethane foaming catalysts with useful retardation properties, and have found that PMD
The inventors have discovered that mixing ETA with a limited amount of an organic carboxylic acid, water, and an organic solvent can solve the above problems and produce a polyurethane foaming catalyst with extremely useful retarding properties, leading to the present invention.

That is, the present invention provides a polyurethane foaming catalyst having retardation properties, which is formed by blending PMDKTA with limited amounts of an organic carboxylic acid, water, and an organic solvent.

When the catalyst of the present invention is used to produce polyurethane foam, since the initial activity is weak, the time from mixing the raw material liquids to starting the 7 ohm formation reaction can be extended.

As a result, the raw material liquid can be sufficiently flowed to every corner of the large mold, and the operability and liquid flowability of the mixed liquid can be improved.

On the other hand, with the catalyst of the present invention, when the foam formation reaction progresses and the reaction temperature rises, PMDI! The organic carboxylate of iTA dissociates thermally, and the organic carboxylic acid reacts with the amine compound formed by the reaction of organic isocyanate or organic incyanate with water and is consumed, so that the original catalytic activity of FMDPTA is not expressed. Ru. As a result, polyurethane foam can be produced without extending the demolding time of the polyurethane foam, that is, without reducing productivity.

Since the catalyst of the present invention exhibits a pH of neutrality or higher when dissolved in water, it does not corrode the materials of the catalyst storage tank or foaming machine. Furthermore, since it is a stable homogeneous solution, it is easy to use, and the catalyst has excellent compatibility without crystallization, precipitation, or phase separation.

Therefore, it is also possible to use it in combination with a conventionally known catalyst, such as triethylenediamine or an organic tin compound.

Next, the present invention will be explained in detail.

PMDETA used in the present invention is permethylated from diethylenetriamine by known methods, such as the Leukart-Wallach reaction described in US Pat. No. 4,026,840 or the reductive methylation reaction described in German Patent No. 2,618,580.

The monobasic organic carboxylic acid of the present invention may be a conventional organic carboxylic acid or a mixture thereof, such as formic acid.

Examples include acetic acid, propionic acid, butyric acid, caprylic acid, 2-ethyl Φsanoic acid, capro/acid, cyanoacetic acid, pyruvic acid, benzoic acid, but especially formic acid, succinic acid, phthalic acid, etc. When using basic acids, these acids
These dibasic acids are excluded from the present invention because they form salts that are difficult to bathe with nTA and organic solvents.

The amount of the organic carboxylic acid is 1 per mole of PMDETA.
15 to 2.0 mol, preferably LIL 75 to 1.0 mol.
5 moles is good. If the range is below this, no effective delay effect will be produced. On the other hand, if the temperature is higher than this, the organic carboxylate of FMDETA will solidify, phase separation will easily occur, and
Since T'H decreases and it becomes acidic, it shows corrosivity to metal materials, which is not preferable.

The water used is usually ion-exchanged water or distilled water.

The amount of water used is between 3.0 and 1&0% by weight of the catalyst, preferably between 5.0 and 10.0%.

If the amount of water is less than 3% by weight, the organic carboxylate of PMDETA tends to crystallize or undergo phase separation. On the other hand, the amount of water is 15.
If it is more than 0% by weight, phase separation tends to occur, and depending on the polyurethane foam, the influence of water becomes large, resulting in disadvantages such as deterioration of the physical properties of the foam.

Organic solvents having 2 to 4 hydroxyl groups include polyols,
Examples Eva ethylene glycol, diethylene glycol, 7
Examples include helene glycol, dipropylene glycol, butanediols, hexanediol, glycerin, etc., but glopylene glycol and diglopylene glycol are preferable. The amount of organic solvent used is 15
~55 important chi is good. If it is less than this, crystallization and phase separation of the organic carboxylate of PMDPTA will occur, which is not preferable. On the other hand, if the amount of organic solvent is 55% by weight or more, the content of P'MDBTA contained in the catalyst will be small, and depending on the polyurethane foam, the influence of the organic solvent will become large, causing disadvantages such as impairing the physical properties of the foam, which is not preferable. .

In producing the catalyst of the present invention, each component is mixed with PMDB under an inert gas atmosphere, such as nitrogen or argon.
After mixing TA with water and an organic solvent, it is preferable to stir the mixture while cooling the container and dropwise mix the organic carboxylic acid at an appropriate speed. Do not mix water or organic solvent with PMDI or TA.
Direct mixing of an organic carboxylic acid is not preferable because salts may precipitate, heat generation is large, and coloration may occur.

The retarded catalyst of the invention thus produced can be used in the production of polyurethanes. Usually, the amount used is 0.02 to 5 parts, preferably 0.05 to 5 parts, based on 100 parts of the polyol used. Furthermore, it can also be used in combination with triethylenediamide/organotin compounds, which are usually used as cocatalysts.

The polyinsyanate that can be used to produce polyurethane foam with the catalyst of the present invention is any known organic polyinsyanate, such as tolylene diincyanate, diphenylmethane diiso7anate, polymerized isocyanate, and aliphatic polyinsyanate. Further, the polyol is a known polyester polyol or polyether polyol. For example, polyester polyols and glycols, usually derived from dibasic acids and polyhydric alcohols, glycerin, pentaerythritol.

These include polyether polyols obtained from the addition reaction of ethylene oxide or propylene oxide to polyhydric alcohols such as trimethylolpropane and sucrose, and amine polyols derived from amine compounds.

In the production of polyurethane, blowing agents (e.g. a'p'at, OH, Ot, etc.) are used as additives, if necessary.
.

Surfactants (e.g. organopolysiloxanes).

Flame retardants and other additives can be used.

As long as the types and amounts of these additives are not deviated from known formats and procedures, they can be used within the commonly used ranges. As stated above, the catalyst of the present invention is extremely useful when dissolved in water. be.

The present invention will be described below based on Examples and Comparative Examples, but the present invention is not limited only to these Examples.

zoonl with magnetic stirrer! PMDITA 5181, dipropylene glycol 16.5f2 and water 26t were placed in a round bottom flask and mixed by stirring under a nitrogen atmosphere. Next, while cooling the round-bottom 72 Scotch, 1.5 times the mole of PMDBTA was added through the dropping funnel.
A yellowish and viscous catalyst liquid was prepared by dropping 00% formic acid. This catalyst solution was a homogeneous solution, and no crystal precipitation or two-phase separation occurred even when it was stored in a constant temperature bath at 0°C for 30 days. A part of this catalyst solution was dissolved in water containing ethanol and the pH was adjusted. When measured, the pH was a5.

Example 2 558? using the same method as Example 1. PMDI! ! TA to 24.82 f dipropylene glycol to door, 097
After mixing with water, 1429f of 100% formic acid was added dropwise to prepare a yellowish and viscous catalyst liquid. This catalyst solution was a homogeneous solution, and no crystal precipitation or two-phase separation occurred even when it was stored in a constant temperature bath at 0° C. for 30 days.

When a part of this catalyst solution was dissolved in water containing ethanol and the pH was measured, the pH was EL9.Example 5 A foaming test was carried out using PMDIiiTA and the catalysts obtained in Examples 1 and 2. I conducted a comparative study.

The mixing ratio (formulation) of the raw materials was set as shown below, and urethane foaming was carried out according to the usual manual foaming procedure. i.e. polyol, water.

Freon, surfactant, and other ingredients are mixed in advance at 20°C.
I kept it. A required amount of this liquid mixture was taken and a catalyst was added thereto to obtain a premix liquid. The required amount of organic incyanate, which had been kept at 20°C in advance, was weighed out and poured into the premix liquid, mixed at high speed using a homo mixer, and kept at 40°C.
It was poured into a 5cm cubic aluminum box and made into urethane foam Jt4. After leaving it in an aluminum box for 5 minutes, it was transferred to a constant temperature bath kept at 70° C. and the time required for the stickiness to disappear by touch was measured as the tack free time (TPT).

Next, a part of the foam was cut out and the density and air permeability were measured and shown in Table 1.

FA-728 (2nd 3rd.

Jetanolami/2. O H202,5 L-5305+31 1.0 R-11" 5.Q TIDA L = 35 (5' 0.45 Catalyst Required amount organic isocyanate (6) EngineeringndθX105 (1)
Polymer polyol obtained from Sanyo Chemical Industries, Ltd. with an average molecular number s, o o' o〇曵2) A polymer polyol obtained from Sanyo Chemical Industries, Ltd. grafted with acrylonitrile-styrene.

(Surfactant obtained from Union Carbide Co., Ltd.)

(4) Freon 11 (5) Triethylenediamine liquid product obtained from Toyo Soda Kogyo Co., Ltd.

(6) 80 parts of tolylene diisocyanate (T-80) obtained from Nippon Polyurethane Kogyo Co., Ltd. and 20 parts of polyisocyanate having an incyanate group number Z3 to 2.7 are mixed with polymerized diphenylmethane diinocyanate obtained from the same company. polyisocyanate mixture.

(7) Number of 2 per 100 tons of premix of raw materials excluding organic incyanate (810 Good Δ Slightly closed foaming From the foaming results in Table 1, assuming the same tack-free time, the catalyst of Example 1 had a cream time of 4.5 seconds. , Example 2
The catalyst was found to have a delay effect of 40 seconds on cream time.

Patent applicant: Toyo Soda Kogyo Co., Ltd.

Claims (1)

[Claims] +11 (a) N, N, N', N", NI-
Polyurethane foaming catalyst 0 characterized by consisting of pentamethyldiethylenetriamine (b) - basic organic carboxylic acid (0) water, and (d) an organic solvent having 2 to 4 hydroxyl groups (2) H, N, N ', N', N''-pentamethyldiethylenetriamine (15-2.
The blowing catalyst according to claim 11), which contains 0 mol of a monobasic organic carboxylic acid. (3) Claim No. (1) or (2) comprising 40 to 12.0% by weight of water and 150 to 35.0% by weight of an organic solvent having 2 to 4 hydroxyl groups as a foaming catalyst.
(4) - The foaming catalyst according to any one of claims (1) to (3), wherein the basic organic carboxylic acid is formic acid. (5) The foaming catalyst according to any one of claims (1) to (4), wherein the organic solvent having 2 to 4 hydroxyl groups is diglobylene glycol or propylene glycol.