JP2655920B2 - Catalyst for polyurethane production - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a catalyst used in the production of polyurethane such as soft, hard, semi-hard or elastomer. More specifically, the present invention relates to a novel catalyst for producing a polyurethane having a tertiary amino group and a hydroxyl group in a molecule and having extremely low odor.

[Conventional technology and its problems]

As for the catalyst for producing polyurethane, conventionally, an organic metal mainly composed of tin and a tertiary amine have been used.
Secondary amines are preferred. For example, compounds such as N-methylmorpholine, triethylenediamine, tetramethylhexamethylenediamine, pentamethyldiethylenetriamine, and dimethylcyclohexylamine have been used as polyurethane production catalysts.

However, the catalysts for polyurethane production that have been developed so far have various problems. That is, N-
Methylmorpholine has an extremely strong irritating odor, and when polyurethane is produced using these compounds, the irritating odor of these compounds remains from the product even after production due to the low boiling point of N-methylmorpholine. . Furthermore, when polyurethane is manufactured using a compound such as triethylenediamine or hexamethylenediamine, the urethane catalyst remaining in the product migrates to another material (for example, a PVC sheet) that comes into contact with the polyurethane, causing discoloration. There are often instances where a product has no commercial value. In addition, PVC products are often used for interior parts of automobiles and the like, and even when polyurethane is not in contact with the catalyst, there are cases where the catalyst volatilizes and contaminates the PVC surface.

Japanese Patent Application Laid-Open No. 46-4846 discloses a catalyst which is considered to be a non-transferable catalyst in a polyurethane resin. (Wherein, R ₁ is an alkyl group having 1 to 6 carbon atoms, or two can be bonded to a nitrogen atom to form a 3- to 6-membered heterocycle, and R ₂ is It is a divalent organic group having no active group capable of reacting with isocyanate other than an amino group.)
Specifically, there is described an example in which a compound such as dimethylaminopropylamine, diethylaminopropylamine, or N- (2-aminoethyl) aziridine is used as a catalyst for producing polyurethane.

However, these compounds all have low boiling points,
It has an extremely strong pungent odor and has difficulties in the working environment.

[Means for solving the problem]

The present inventors have conducted intensive studies to solve the above problems, and as a result, a compound having a tertiary amino group and a hydroxyl group in the molecule has extremely low odor, and is suitable as a catalyst for polyurethane production. It has activity and, after the production of polyurethane, has been found to be non-migratory in the polyurethane resin, thereby completing the present invention.

That is, the present invention provides the following general formula: (In the formula, R represents hydrogen or a methyl group, and n represents an integer of 0 to 3.) A catalyst for producing a polyurethane comprising a compound represented by the following formula:

The novel catalysts for the production of polyurethanes according to the invention are, for example, N 2
It can be easily obtained as -methyl-4-hydroxy-piperidine, and can be easily produced by adding ethylene oxide and propylene oxide thereto using potassium hydroxide as a catalyst and purifying it by distillation.

The amount of the novel catalyst used in the present invention is preferably in the range of 0.01 to 10 parts, more preferably 0.1 to 10 parts, per 100 parts (parts by weight, the same applies hereinafter) of the polyol used for the production of polyurethane.
Although it is in the range of 5 parts, it is also possible to remove the simplicity 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 or an organic metal compound such as triethylenediamine or tetramethylhexamethylenediamine which is generally and generally used in the production of polyurethane.

Polyisocyanates that can be used when producing polyurethane using the novel catalyst of the present invention include:
Any one may be used as long as it is usually used for the production of polyurethane. Examples include range isocyanate.

Polyols that can be used in producing polyurethane using the novel catalyst of the present invention include generally known polyether polyols and polyester polyols. For example, glycol, glycerin, pentaerythritol, trimethylolpropane, polyether polyols obtained by adding ethylene oxide or propylene oxide to polyhydric alcohols such as sucrose, ethylenediamine, tolylenediamine, diamine such as diphenylmethanediamine ethylene oxide, Examples thereof include amine polyols obtained by adding propylene oxide, and polyester polyols produced from ordinary dibasic acids and polyhydric alcohols.

Further, a polymer polyol is used as a polyol for producing a polyurethane foam. It is prepared by polymerizing one or more ethylenically unsaturated monomers dissolved or dispersed in any of the aforementioned polyols in the presence of a free radical catalyst. Representative examples of the ethylenically unsaturated monomers are as follows, and they may be used alone or in combination. That is, ethylene, propylene, acrylonitrile, vinyl chloride, vinylidene chloride, styrene,
Methyl methacrylate, butadiene and the like. Generally, such compounds are peroxides, persulfates,
Using any of a radical generating initiator including percarbonate, perborate and azo compound, from about 40 ° C.
It is prepared by polymerizing monomers in a substrate polyol at a temperature between 0 ° C.

When producing a polyurethane using the novel catalyst of the present invention, CCl ₃ F, CF ₃ CHCl ₂ , CCl ₂ F
Blowing agents such as CH ₃ and CH ₂ Cl ₂ , surfactants such as organopolysiloxane, flame retardants such as alkyl halide compounds and phosphorus halide compounds, and other additives can be used. About the kind and addition amount of these additives, they can be used sufficiently within the range usually used.

(Operation)

The following describes how the novel catalyst of the present invention works to bring about the effects of the present invention.

The polyurethane production catalyst of the present invention has a very low odor due to its high boiling point. In addition, the catalyst of the present invention has a tertiary amino group in the molecule and has an appropriate activity as a catalyst for producing polyurethane, so it is considered that the polyurethane production process can be easily controlled. Furthermore,
Since the catalyst of the present invention has a hydroxyl group in the molecule, it reacts with the isocyanate, which is a polyurethane raw material, by the end of the polyurethane formation reaction, and after the completion of curing,
It is considered that the catalyst does not migrate to the product surface, and therefore, discoloration, which is various troubles caused by this phenomenon, is eliminated. This solves the coloring of PVC / urethane composite products such as automotive interior parts.

〔Example〕

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 3 and Comparative Examples 1 and 2 Various polyurethanes were produced according to the usual procedures using the raw materials shown in Table 1.

That is, polyol, water, surfactant, catalyst, blowing agent,
Polyisocyanate and the like were kept at 25 ° C., weighed into a paper cup, and mixed with a laboratory mixer to form a urethane foam.

The cream time and rise time when forming a urethane foam were measured. Here, the cream time means the time from the start of mixing of the raw materials to the start of foaming, and the rise time means the time until the polyurethane foam apparently reaches the maximum height.

 Table 2 shows the results.

Test Example 1 A vinyl chloride sheet was manufactured according to the composition shown in Table 3 and used for a discoloration test.

The vinyl chloride sheet is spread on the bottom of an aluminum foam mold of 10 cm × 20 cm × 2 cm, and a urethane mixture having the composition shown in Table 1 is introduced. The catalyst was used in Examples 1 to 3 and Comparative Examples 1 and 2.
Using the catalyst used in 2, the catalyst amount was adjusted so that the rise time was 90 seconds.

After the urethane is sufficiently cured, the composite of the vinyl chloride sheet and the urethane foam is taken out of the mold. After standing for 48 hours, put in a perfect oven at 110 ° C. to discolor the sheet. After a certain time, remove the foam composite,
The degree of discoloration (color difference, ΔE) of the vinyl chloride sheet on the surface in contact with the urethane foam is measured by a color difference meter manufactured by Suga Test Machine.

 Table 4 shows the results.

Test Example 2 The odor of the catalyst of the present invention and the comparative catalyst was evaluated by the following method.

The catalyst used in Examples 1 to 3 and Comparative Examples 1 and 2 was MN-700
(Glycerin-based polyether polyol manufactured by Mitsui Toatsu Chemical Co., Ltd., molecular weight: about 700) was dissolved to a predetermined concentration, and evaluated by a selected smell panel.

 The evaluation criteria at this time are as follows.

◎: Almost no smell ○: Slight smell △: Smell ×: Strong smell The results of these evaluations are shown in Table 5.

Usually, the amount of catalyst added is 10% or less (preferably 3 to 5%).
%), And from the results in Table 5, it can be seen how low the odor of the catalyst for producing a novel polyurethane of the present invention is.

〔The invention's effect〕

As specifically shown in the examples, the polyurethane production catalyst of the present invention reacts with the isocyanate group at the end of the polyurethane production reaction and is taken into the inside of the polyurethane molecule. It is a non-migratory catalyst for polyurethane production that does not vaporize or vaporize. In addition, since the catalyst has a higher catalytic activity than conventionally used catalysts such as methylmorpholine, ethylmorpholine, and dimethylbenzylamine, it has an economical advantage that the amount used is small.

If the non-migratory performance is described in more detail, when polyurethane foam and a vinyl chloride sheet are integrally molded using a catalyst known to date, for example, triethylenediamine, triethylenediamine is converted from the polyurethane foam after foaming and curing is completed. Moved to vinyl sheet, and later vinyl chloride sheet was colored yellow,
There is a disadvantage of discoloration. This phenomenon is accelerated by heating and is an important problem in the automotive industry, where there are many such moldings. However, by using the catalyst for producing polyurethane of the present invention, the catalyst no longer migrates from the polyurethane foam, and the above-mentioned problem is solved.

Furthermore, since the catalyst for producing polyurethane of the present invention has a high boiling point and very low volatility, there is almost no odor. This makes it possible to significantly improve the working environment in the polyurethane foam production process.

Claims (1)

(57) [Claims] 1. The following general formula: (Wherein, R represents hydrogen or a methyl group, and n represents an integer of 0 to 3).