JPH0940740A - Low-odor phenol foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a low-odor phenol foam by maintaining the residual formaldehyde content of a dimethylene-ether phenol resin below a specified value and incorporating a perfume into the resin. SOLUTION: A dimethylene-ether phenol resin having a residual formaldehyde content of 0.3wt.% or lower is obtd. by thermally reacting at least one phenol source (e.g. phenol or resorcinol) with a formaldehyde source (e.g. paraformaldehyde) in a molar ratio of about 0.5-2.5 and, after completing the reaction, removing unreacted compds. under a reduced pressure. A low-odor phenol foam is obtd. by mixing the phenol resin with a polyisocyanate (e.g. tolylene diisocyanate) in an equivalent ratio of about 0.3-3.0, mixing 100 pts.wt. thus obtd. mixture with about 5-50 pts.wt. blowing agent (e.g. a low-boiling hydrocarbon), 0.1-5 pts.wt. foam stabilizer (e.g. sorbitan fatty acid ester), and 0.001-1 pt.wt. perfume with a high-speed mixer, pouring the resulting foaming mixture into a mold, and allowing the foaming mixture to foam and cure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low odor phenolic foam used as a heat insulating material in building materials and the like.

[0002]

2. Description of the Related Art Phenol foam is heat-resistant, flame-retardant,
Because of its excellent properties such as low smoke emission, it is used for building materials such as heat insulating materials and the like, and its demand is increasing. However, the resole-type phenol resin is poor in storage stability of the resin, and the novolac-type phenol resin is solid, so that it is inconvenient to handle, and thus its use is limited. On the other hand, the dimethylene ether type phenol resin has a relatively good storage stability, but has a problem of strong odor because formaldehyde, which causes an irritating odor, remains.

[0003]

In recent years, from the viewpoint of improving the working environment, the demand for reducing odor has become very strong. The present inventors, as a result of intensive research to solve the above problems, dimethylene ether type phenol resin,
A phenol foam comprising a mixture of polyisocyanate, a foaming agent, and a foam stabilizer as the main components, which is foamed and cured, and the residual formaldehyde content of the dimethylene ether type phenol resin is set to 0.3% or less and a fragrance is contained. It was found that the odor was reduced by the addition.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a phenol foam comprising a dimethylene ether type phenol resin, a polyisocyanate, a foaming agent and a foam stabilizer, which are foamed and cured in a phenol foam. A low odor phenolic foam characterized in that the ether type phenolic resin has a residual formaldehyde content of 0.3% or less and contains a fragrance.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The dimethylene ether type phenol resin used in the present invention is, for example, JP-B-47-5087.
Known materials can be used according to the publication No. Examples of the phenol source include monohydric phenols such as phenol, cresol, ethylphenol, xylenol, butylphenol, octylphenol and nonylphenol, polyhydric phenols such as resorcinol, catechol and bisphenol A, and one and two halides of the above phenols. There are combinations of more than one species. As the formaldehyde source, formalin, which is an aqueous solution of formaldehyde, and solid paraformaldehyde can be used alone or in combination. The molar ratio of phenol to formaldehyde is preferably 0.5 to 2.5. If the amount is 0.5 or less, a large amount of unreacted phenol remains after the reaction is completed, and this is distilled off at the time of concentration, resulting in a low resin yield. If it is 2.5 or more, after the reaction is completed, a large amount of formaldehyde having a significant odor remains unreacted, and it becomes difficult to reduce the residual formaldehyde.

As a method for removing unreacted formaldehyde and reducing residual formaldehyde, the reaction solution is washed with water,
Physical methods such as vacuum distillation under reduced pressure, steam distillation, reduced pressure steam distillation, etc. and melamine, aniline, 2-amino-2-ethyl-which has a high reaction activity with formaldehyde and reacts with unreacted formaldehyde to reduce residual formaldehyde.
There is a chemical method using 1,3-propanediol or the like. The above methods may be used alone or in combination. The amount of residual formaldehyde is preferably 0.3% or less. More preferably, it is 0.1% or less. 0.3%
If the amount is larger, the low odor effect due to the addition of the fragrance is reduced, or the amount of the fragrance added is increased, resulting in an increase in price.

As the polyisocyanate compound, tolylene diisocyanate (TDI), polymethylene polyphenyl isocyanate (MDI), hexamethylene diisocyanate (HMDI) and the like can be used. Note that these polyisocyanate compounds are only examples,
It is also possible to use other polyisocyanate compounds containing two or more isocyanate groups in the molecule. Further, two or more of the above polyisocyanate compounds can be used in combination. The ratio of dimethylene ether type phenol resin to polyisocyanate compound is 0.3 to 3.0.
(Equivalent ratio) is preferable. If it is less than 0.3, foaming becomes uneven. If it exceeds 3.0, the foam itself becomes brittle.

As the foaming agent, HCFC123, 141
There are alternative fluorocarbons such as b, low-boiling point aliphatic monovalent hydrogen or halogen compounds thereof, but they are not particularly limited. The addition amount is preferably 1 to 50 parts by weight based on 100 parts by weight of the total of the dimethylene ether type phenol resin and the polyisocyanate compound. If it is less than 1 part by weight, the expansion ratio is low and the heat insulating property is deteriorated. If it exceeds 50 parts by weight, the expansion ratio becomes high and the strength of the foam decreases.
As the foam stabilizer, there are nonionic surfactants such as sorbitan fatty acid ester and ethylene oxide adducts such as alkylphenol, and silicon nonionic surfactants. The amount of the foam stabilizer is preferably 0.1 to 5.0 parts based on 100 parts by weight of the total of the dimethylene ether type phenol resin and the polyisocyanate compound. If it is 0.1 part or less, foaming becomes nonuniform. Even when the amount is 5 parts or more, the effect of the foam stabilizer is not increased, and the price is increased.

As the fragrance, a natural fragrance and a synthetic fragrance can be used alone or in combination of two or more kinds.
It is also possible to use industrial product flavors and fragrances, which are combinations of natural flavors and synthetic flavors. Examples of natural flavors include animal flavors such as musk and plant flavors such as turpentine oil and pine oil. As synthetic fragrances, phenylethyl alcohol, menthol, benzyl acetate, benzyl alcohol,
There is geraniol. The above is a typical example and is not particularly limited. The amount of the fragrance added is preferably 0.001 to 1.0 part with respect to 100 parts by weight of the total of the dimethylene ether type phenol resin and the polyisocyanate compound. If it is 0.001 part or less, there is no low odor effect. 1.
If it is 0 parts or more, the odor of the fragrance becomes too strong and the cost increases.

A compound obtained by reacting a compound having active hydrogen such as a polyhydric alcohol or a polyvalent amine as a starting material with a oxirane compound such as ethylene oxide and / or propylene oxide as a modifier for a dimethylene ether type phenol resin. It is also possible to use such as. It is also possible to use an additive (reaction accelerator, reaction retarder) for adjusting the reaction between the dimethylene ether type phenol resin and the polyisocyanate compound. It is also possible to add an inorganic acid such as phosphoric acid, hydrochloric acid or sulfuric acid, or an organic acid such as paratoluenesulfonic acid, xylenesulfonic acid or phenolsulfonic acid, which is a compound that promotes the reaction of the dimethylene ether type phenol resin. Flame retardance,
Flame retardants, inorganic fillers, and the like may be added as appropriate to enhance smoke generation.

[0011]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited to these examples. Example 1 The synthesis of dimethylene ether type phenol resin: A is shown below. Phenol 470g, 37% formalin 405
g and 2 g of lead acetate are placed in a 1 liter separable round bottom flask equipped with a condenser, a stirrer and a thermometer, reacted at reflux temperature for 7 hours, and then cooled. After standing for 1 hour, the supernatant is removed. After the removal, 300 g of distilled water is added and stirred for 30 minutes.
After stirring, the mixture is allowed to stand for 1 hour, and the supernatant is removed. After washing with water four times, the internal temperature was set to 60 ° C., the pressure was reduced, and dehydration and deformaldehyde were performed. Once dehydration is complete,
Distilled water (50 g) was added, the pressure was reduced again, and dehydration and deformaldehyde operations were performed. This operation was repeated until the residual formaldehyde concentration of the resin became 0.3 or less. The resin A thus obtained had a residual formaldehyde concentration of 0.09%. The residual formaldehyde concentration was quantified by gas chromatography (TCD detection).

Example 2 Resin: A: 200 g, foam stabilizer 2 g (SH-193: manufactured by Toray Silicone Co., Ltd.), foaming agent 20 g (CFC141b: manufactured by Mitsui Fluorochemicals Co., Ltd.), fragrance 0.1 g (G-443).
(2: Takasago International Co., Ltd.) was thoroughly mixed and dissolved, 200 g of crude diphenylmethane diisocyanate (Millionate MR-200: manufactured by Nippon Polyurethane Co., Ltd.) was added, and the mixture was stirred with a high-speed stirrer (2000 rpm) for 10 seconds. Thereafter, it was poured into a mold and foamed. Table 1 shows the odor evaluation and foam density during foaming.

Examples 3 to 5 Foams were obtained in the same manner as in Example 2 using the resin A described in Example 1. Table 1 shows the composition, odor evaluation, and foam density.

Comparative Example 1 The synthesis of dimethylene ether type phenol resin: B is shown below. Phenol 470g, 37% formalin 405
g and 2 g of lead acetate were placed in a 1 liter separable round bottom flask equipped with a cooling tube, a stirrer and a thermometer and reacted at the reflux temperature for 7 hours, then the internal temperature was set to 60 ° C. and the pressure was reduced to dehydrate. The resin: B thus obtained had a residual formaldehyde concentration of 0.
5%.

Comparative Example 2 200 g of resin: B, 2 g of a foam stabilizer (SH-193: manufactured by Toray Silicone Co., Ltd.) and 20 g of a foaming agent (CFC141b: manufactured by Mitsui Fluorochemicals Co., Ltd.) were mixed and dissolved, and then 200 g of crude diphenylmethane diisocyanate ( Millionate M
R-200: manufactured by Nippon Polyurethane Co., Ltd. was added, and the mixture was stirred with a high speed stirrer (2000 rpm) for 10 seconds. Thereafter, it was poured into a mold and foamed. Table 1 shows the odor evaluation and foam density during foaming.

[0016]

[Table 1] Foam formulation and density Density: Measured according to JIS A-9514. Foam stabilizer: SH-193 (manufactured by Toray Silicon Co., Ltd.) TW-P120 (manufactured by Kao Corporation) Foaming agent: CFC141b, CFC123 (manufactured by Mitsui Fluorochemicals Co., Ltd.) Fragrance: 80840, 80400 (manufactured by Takasago Fragrance Company) Polyisocyanate: Millionate MR -200 (manufactured by Nippon Polyurethane Co., Ltd.) Odor evaluation: ◯: no formaldehyde odor is felt, fragrance is x: Formaldehyde odor is felt

[0017]

EFFECTS OF THE INVENTION According to the present invention, a low-odor phenolic foam can be provided by reducing the residual formaldehyde content of the dimethylene ether type phenol resin to 0.3% or less and adding a fragrance.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08G 101: 00) C08L 75:04

Claims (2)

[Claims] 1. A dimethylene ether type phenolic resin,
A phenol foam comprising a mixture of polyisocyanate, a foaming agent, and a foam stabilizer as a main component, which is foamed and cured, and the residual formaldehyde content of the dimethylene ether type phenol resin is 0.3% or less and contains a fragrance. A low-odor phenolic foam characterized by being. 2. The low odor phenolic foam according to claim 1, wherein the residual formaldehyde content is 0.1% or less.