JPS62115018A - Catalyst for production of polyurethane - Google Patents

Abstract

PURPOSE:To obtain a polyurethane production catalyst which is low-odor, water- soluble and easily handleable, can work well even in a small amount of addition because of its high catalytic activity and has excellent heat sensitivity, comprising a specified compound having a cyclohexane ring in the molecule. CONSTITUTION:A compound of the formula is used as a catalyst for the production of polyurethane by reacting a polyol with a polyisocyanate. The compound of the formula can be easily produced by reductively methylating xylylenediamine and converting the benzene ring of the product into a cyclohexane ring by hydrogenation. Because a catalyst comprising the compound of the formula has excellent temperature sensitivity, it can keep the viscosity of a reaction mixture low at low temperature and, by elevating the temperature, the reaction mixture can be rapidly cured into a polyurethane resin. Therefore, even when a mold of a complicated structure is used, the mold can be filled to the corners with the reaction mixture and the mixture can be cured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a catalyst used in the production of polyurethanes such as soft, hard, semi-hard or elastomers. More specifically, the present invention relates to a novel catalyst for producing polyurethane that has an extremely low odor and has a cyclohexane ring in its molecule.

[Conventional technology]

Conventionally, metal-based catalysts such as tin-based, iron-based, titanium-based, manganese-based, etc., and amine-based catalysts have been used as catalysts for polyurethane production, and tertiary amines are preferably used as catalysts for polyurethane production. It is already widely known that For example, N-methylmorpholine, N
-ethylmorpholine, triethylenediamine (1,4-
diazabicyclo(2,2,2)octane), N, N,
N',N'-tetramethyl-1,6-hexanediamine, N,N,N',N',N'-pentamethyldiethylenetriamine, N,N-dimethylcyclohexylamine, N,N-dimethylethanolamine, etc. The compound is used as a catalyst for polyurethane production. Further, N,N-dimethylbenzylamine is known as a tertiary amine catalyst having almost the same activity as a morpholine catalyst, but since this compound is insoluble in water, it is difficult to use in the work.

Among these polyurethane production catalysts, relatively weakly active catalysts (weak catalysts) include N-methylmorpholine,
Examples include compounds such as N-ethylmorpholine and N,N-dimethylbenzylamine. This weak catalyst plays an extremely important role in delicately controlling the polyurethane manufacturing process.

[Problem that the invention seeks to solve]

However, the catalysts for producing polyurethane that have been developed so far have various problems. That is, N-
Methylmorpholine and N-ethylmorpholine have extremely strong pungent odors, and when polyurethane is produced using these compounds, N-methylmorpholine,
Due to the low boiling point of N-ethylmorpholine, the product emits a pungent odor of these compounds even after production.

Furthermore, when polyurethane is produced using these compounds, the urethane catalyst remaining in the product may be mixed with other compounds that come into contact with the polyurethane (for example, converting polyurethane into PvC).
There are many cases in which it transfers to the coated PvC sheet), causing yellowing, etc., and rendering the product worthless. In addition, N,N-dimethylbenzylamine has a strong irritating odor, and when producing polyurethane using this compound, it takes a long time to remove the mold (cure time), which reduces productivity. It has the disadvantage that it decreases. Furthermore, when producing polyurethane foam, urethane catalysts are usually used in the form of amine water dissolved in water, but N,N-dimethylbenzylamine has poor solubility in water, so it is difficult to use it in the form of amine water. This has the disadvantage of greatly reducing workability.

In addition, most of the catalysts for polyurethane production that have been developed so far show a gradual increase in activity as the temperature rises, whereas they show a rapid increase in activity as the temperature rises (temperature-sensitive ) There is a need to develop catalysts that have satisfactory performance in applications where temperature sensitivity is desired.

[Means for solving problems]

As a result of intensive studies to solve the above problems, the present inventors found that a compound having a cyclohexane ring and two dimethylamino groups in the molecule has a suitable activity as a catalyst for polyurethane production. The present invention was completed based on the discovery that the material is extremely low-temperature and has excellent temperature sensitivity.

That is, the present invention provides a catalyst for producing polyurethane comprising a compound represented by the following formula.

The novel catalyst for polyurethane production of the present invention can be used, for example:
It can be easily produced by reductively methylating xylylene diamine and further hydrogenating it to convert the benzene ring into a cyclohexane ring.

The amount of the novel catalyst of the present invention to be used is preferably in the range of 0.01 to 10 parts, particularly preferably 0.1 to 4 parts, based on 100 parts of polyol (by weight, same hereinafter) used for producing polyurethane. However, it is also possible to use the catalyst outside this range for the purpose of optimizing the polyurethane production process by controlling the amount of catalyst added. Further, the novel catalyst of the present invention can be used in combination with a tertiary amine represented by triethylenediamine and an organometallic compound represented by an organotin compound, which are commonly used as cocatalysts in the production of polyurethane.

The polyisocyanate that can be used when producing polyurethane using the novel catalyst of the present invention may be any generally known polyisocyanate, such as 2°4-tolylene diisocyanate, 2°4-tolylene diisocyanate,
．． 6-tolylene diisocyanate), 4.4”-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, lysine isocyanate, xylylene diisocyanate, cyclohexane diisocyanate, toluidine diisocyanate, p
-phenylene diisocyanate, o-phenylene diisocyanate, m-phenylene diisocyanate, 1.5
-naphthylene diisocyanate, 4.4"-biphenyl diisocyanate, 3.3"-dimethylbiphenyl-4
Examples include ゜4゛-diisocyanate, 3.3゜-dimethoxybiphenyl-4,4゛-diisocyanate, and the like.

As polyols that can be used when producing polyurethane using the novel catalyst of the present invention, generally known polyester polyols, polyether polyols, etc. can be used. For example, ordinary dibasic acids and polyhydric Polyester polyols manufactured from alcohol,
Polyether polyols obtained by adding ethylene oxide or propylene oxide to polyhydric alcohols such as glycol, glycerin, pentaerythritol, trimethylolpropane, and sucrose, or triethylenediamine, tolylenediamine, 1,6-hexanediamine, 1. Examples include amine polyols obtained by adding ethylene oxide or propylene oxide to polyvalent amines such as 3-propione diamine and isophorone diamine. Additionally, polymer polyols are organic polyol reactants that can be used in producing polyurethane foams. It is made by polymerizing one or more ethylenically unsaturated monomers dissolved or dispersed in any of the other types of polyols mentioned herein in the presence of a free radical catalyst. Representative examples of ethylenically unsaturated monomers include the following, which may be used alone or in combination. namely, ethylene, propylene, acrylonitrile, vinyl chloride, vinylidene chloride, styrene, alpha methylstyrene, methyl methacrylate and butadiene.

Generally, such compositions are prepared using any of the radical generating initiators including peroxides, persulfates, percarbonates, perporates, and azo compounds.
It is made by polymerizing monomers in a base polyol at temperatures between 150°C and about 150°C.

When producing polyurethane using the novel catalyst of the present invention, additives such as CFCl3 and cozc may be used as necessary.
Foaming agents such as tz, surfactants such as organopolysiloxane, flame retardants such as halogenated alkyl compounds and halogenated phosphorus compounds, and other additives can be used. The types and amounts of these additives can be sufficiently used within the types and ranges commonly used.

[For production]

The present invention provides a novel catalyst for producing polyurethane consisting of a compound represented by the following formula. Below, how the novel catalyst of the present invention functions to bring about the effects of the present invention will be explained. state

The novel catalyst for polyurethane production of the present invention is believed to have extremely low odor because its molecular weight is relatively larger than those known so far and its boiling point is high. In addition, the catalyst of the present invention has a (CH3)tNL group in the molecule, has suitable activity as a catalyst for polyurethane production, and has a number of nitrogen atoms per molecular weight that has not been previously known. It is thought that the polyurethane manufacturing process can be easily controlled because the number of

Further, the novel catalyst of the present invention has temperature sensitivity, but the reason for this is not clear.

〔Example〕

EXAMPLES The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited only to these Examples.

Example 1 and Comparative Examples 1 to 3 The mixing proportions of raw materials for producing polyurethane were as shown in Table 1, and urethane foaming was carried out according to the usual procedure. That is, polyol, water, surfactant, catalyst, blowing agent, and polyisocyanate were mixed, stirred, and poured into a paper cup kept at 20°C to form a urethane foam (the top of the paper cup was open). .

Tables 2 to 4 show the results of evaluating the performance of the catalyst for producing polyurethane of the present invention and the conventional catalyst for producing polyurethane. In the table, cream time means the time from the start of mixing and stirring of raw materials until just before foaming starts, and gel time means the time when a sharp object is brought into contact with the surface of the polyurethane foam and then separated. In the case of polyurethane foam, it refers to the time required for the polymerization to sufficiently progress before threading from the polyurethane foam.

Tack-free time refers to the time it takes for the resin to no longer adhere to the fingertips (tack-free) when you touch polyurethane foam with your fingers.

Moreover, rise time means the time until the polyurethane foam achieves its maximum apparent height.

1st Table Umbrella 1: Aromatic amine polyol (OH
V=450) Book 2: Sugar-based polyether polyol manufactured by Sumitomo Bayer Urethane ■ (OHV=530) Book 3: Glycerin-based polyether polyol manufactured by Mitsui Toatsu Urethane ■ (OHV
= 235) *4; Surfactant umbrella 5 manufactured by Nippon Unicar; Isocyanate manufactured by Mitsui Toatsu Urethane ■ (mixture of crude MDI and TDI prepolymer, NCOχ = 31
) Table 2 Table 3 Table 4 Table 4 Example 2 Using the production catalyst of the present invention and a comparative catalyst, odor and reaction rate constant were evaluated.

(Evaluation of odor of catalyst for polyurethane production) - Odor check test method for amine catalyst Add amine urethane catalyst to MN-700 (glycerin-based polyether polyol manufactured by Mitsui Toatsu ■, molecular weight approximately 700) to a specified concentration. and evaluated by a selected odor panel of 50 people. The results are shown in Table 5. The criteria for odor evaluation are as follows.

◎: Almost no odor ○: Slight odor △: Odor ×: Strong odor Table 5 Note that the amount of catalyst added is usually 10% or less (preferably 3 to
5%), and from the above table it can be seen how the novel catalyst for producing polyurethane of the present invention has extremely low odor.

(Evaluation of reaction rate constant) In order to show how excellent the temperature sensitivity of the novel catalyst for producing polyurethane of the present invention is, the results of evaluating the reaction rate constant of the reaction between isocyanate and polyol are shown below. Shown in Figure 1.

The reaction rate constant was calculated according to the method described in Industrial Chemistry Magazine, Vol. 65, No. 9 (1962), page 106 onwards.

For comparison, the temperature dependence of the following catalyst, which is relatively temperature sensitive, is also shown.

〔Effect of the invention〕

As specifically shown in the examples, the catalyst for producing polyurethane of the present invention has extremely low odor and has a higher odor than N-methylmorpholine, N-ethylmorpholine, N,N-dimethylbenzylamine, etc. Then, because the catalytic activity is strong,
It has the economical advantage of requiring only a small amount to be added. Furthermore, in conventional polyurethane production processes, tertiary amine-based urethane catalysts are usually used in the form of aqueous amine solutions, but the novel catalyst for polyurethane production of the present invention can be dissolved arbitrarily in water. Therefore, it does not cause any hindrance to the conventional polyurethane manufacturing process.

Furthermore, since the catalyst of the present invention has extremely excellent temperature sensitivity, the viscosity of the raw material can be kept to a small value at low temperatures, and the polyurethane resin can be converted extremely quickly at high temperatures. It can be hardened. Therefore, even when using a mold with a fine structure, the raw material can be supplied to every corner of the mold and quickly cured, making it a catalyst that greatly contributes to rationalizing the manufacturing process and improving product quality. It can be said that

[Brief explanation of drawings]

FIG. 1 is a diagram showing the temperature dependence of reaction rate constants for catalysts of the present invention and comparative catalysts.

Claims (1)

[Claims] The following expression ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ A catalyst for producing polyurethane consisting of a compound represented by: