JPS63245420A - Production of polyisocyanurate foam - Google Patents

Abstract

PURPOSE:To obtain the title foam having a good compatibility with a halohydrocarbon blowing agent and excellent resistance to flame and smoking, by reacting an excess organic polyisocyanate with a specified mixed polyol in the presence of a blowing agent. CONSTITUTION:In the reaction of an excess organic polyisocyanate (e.g., diphenylmethane diisocyanate) with a polyol in the presence of a blowing agent and, optionally, a trimerization catalyst, said polyol comprises a mixture of at least 5%, based on the total polyol, novolac phenolic resin polyol (A) [e.g., an adduct of (pentafunctional) novolac phenolic resin with propylene oxide], at least 5%, based on the total polyol, polyester polyol (B) (e.g., a reaction product of phthalic anhydride with diethylene glycol) and a polyether polyol (C) (e.g., an adduct of glycerol with propylene oxide). The title foam having a good compatibility with a halohydrocarbon blowing agent, a low calorific value of combustion and excellent resistance to flame and smoking can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing polyisocyanurate foams.

[Conventional technology]

Conventionally, as a method for producing polyisocyanurate foam, there is a technology that uses a novolak type pheno-fV resin polyol as a polyol component (for example, Japanese Patent Publication No. 1983-1982).
Publication No. 679).

[Problem that the invention seeks to solve]

However, this material has problems such as poor compatibility with halogenated hydrocarbon blowing agents and high heat generation during combustion.

[Second method to solve the problem]

The present inventors have conducted extensive studies on a method for producing polyisocyanurate foam, which has good compatibility with halogenated hydrocarbon blowing agents, low calorific value during combustion, and excellent flame resistance and smoke-emitting properties. As a result, we arrived at the present invention.

That is, the present invention provides a method for producing a polyisocyanurate foam by reacting an excess organic polyisocyanate and a polyol in the presence of a blowing agent and, if necessary, a trimerization catalyst and other auxiliary agents. A polyisocyanurate characterized by using 5% or more of a novolac type phenolic resin polyol, a3) a polyester polyol-μ of 5% or more based on the total weight of polyol-v, and (C) a polyether polyol. This is the foam manufacturing method.

The novolac type resin polyol (8) used in the present invention has a structure in which an alkylene oxide is added to a novolac type phenol resin, which is a thermoplastic condensation product obtained by reacting phenols and aldehyde substances using an acidic catalyst. The following compounds are mentioned.

Examples of phenols include phenol, cresol/xyleno-μ, resorcinol, hydroquinone, p-amylphenol/L/, and p-pheniμphenol.

Compounds having a phenolic hydroxyl group such as chlorphenol-μ, bisphenol A, and fe/-μ sulfonic acid, and mixtures of two or more thereof, are exemplified, and phenol is preferred.

Examples of the aldehyde substance include formalin, paraformaldehyde, acetaldehyde, furfurer, and mixtures of two or more thereof, with formalin being preferred.

Examples of the acidic catalyst include inorganic acids such as sulfuric acid, hydrochloric acid, and phosphoric acid, and organic acids such as formic acid, oxalic acid, acetic acid, and para)A/enesulfonic acid.

The novolac type phenolic resin may be any known one, and includes those having usually 2 to 1 (1) aromatic rings per molecule, preferably 8 to 6 aromatic rings.

A specific example of the novolak type pheno-A/resin is a pentamer which is a condensation product of phenol with formalin.

Examples of alkylene oxide include ethylene oxide,
Propylene oxide, bunalen oxide. Examples include tetrahydrofuran, styrene oxide/epichlorohydrin, etc. Alkylene oxide alone is 2
More than one kind may be used in combination; in the latter case, block addition, random addition, or a mixture of both may be used. Among these alkylene oxides, preferred ones have an ethylene oxide/propylene oxide weight ratio of 0/10.
0 to 10010, more preferably +30
/70 to To/80. The higher the ethylene oxide content, the better, but if it exceeds 50, the compatibility with the halogenated hydrocarbon blowing agent decreases.

The alkylene oxide may be added to this novolak type phenol resin by any known method, for example, using Asahi catalyst or in the presence of a catalyst (alkali catalyst, amine catalyst, acidic catalyst, etc.), under normal pressure or under pressure. It will be held on.

The OH value of the novolac type phenolic resin polyol is usually 100-400%, preferably 200-300.

If the OH number is less than 100, the dimensional stability of the obtained foam will be poor, and if it exceeds 400, the viscosity of Polio-M itself will be high and the workability will be poor.

The polyether polyol 03) used in the present invention is preferably an aromatic polyether polyol μ, for example, a polyether polyol p made from an aromatic polycarboxylic acid and a polyhydric alcohol. Examples of aromatic polycarboxylic acids (which may also be anhydrides) include phttv acid, isophthalic acid, terephthalic acid, and their anhydrides. Preferable are aromatic dicarboxylic acids and their anhydrides. Examples of polyhydric alcohols include ethylene. Glycol, diethylene glycol-tv, fluoropylene gellicol, 1,6-hexanediol, neopentylene glycol/I/, glycerin.

Trinotyrolfuroban t pentaerythritol.

norditol. Examples include sucrose, etc., and alkylene oxide low molar adducts of these alcohols. Examples of this alkylene oxide include those listed in the section of novolak type phenol/L/resin in (8), and the same as those mentioned above, and preferred ones are also the same.

The OH value of aromatic polyester polyol-μ is 100 to 40
0, preferably 250-880. OH value is 100
The dimensional stability of the obtained foam deteriorated in the US
If it exceeds 00, the foam will become rough due to unreacted carboxylic acid.

It is also possible to use aliphatic polyester polyols as CB).

Examples of the polyether polyol (C) used in the present invention include compounds having a structure in which an alkylene oxide is added to a compound having at least two active hydrogen atoms. Compounds having at least two types of active hydrogen atoms include 2- to 8-functional polyhydric alcohols (ethylene glycol ν, propylene glyco-I, dipropylene glyco-/L/, diethylene glyco-I, glycerin, diglycerin, etc. ) + low μ propane, hexanetriol, hexy V glycol, neopentylene glycol.

Pentaerythritol/L/, 1,4-butanedio-...
soμpitou/L/, mannido-/L/, inocyto-A/
, sucrose, trehalose, etc.); novolak-type pheno-
#Mt+& polyvalent pheno-A/(binufenoμA
, hydroquinone, etc.]; ammonia, amino compounds [
Examples include A IV canolamines (jetanolamine, triethanol-μ amine, etc.) and polyamines (A lylene diamine, phenylene diamine, xylylene diamine, ethylene diamine, diethylene triamine, etc.). Among these, preferred are glycerin and pentaerynurito IV* Soμ Pito M, sucrose, tolylene diamine.

It is ethylenediamine.

Examples of the alkylene oxide include those listed in the section of novolac type pheno-μ resin in (8),
Preferred items are also the same.

Two or more of these polyethers (for example, polyethers having different numbers of functional groups or different OH values) may be used in combination.

The OH value of the polyether polyol-μ of (C) is 80 to 13
50, preferably 150 to SOO, more preferably 20
It is 0-400. If the value of (C) is less than 80, the dimensional stability of the obtained r-form becomes poor, and 1350
If this is exceeded, the foam becomes brittle and cannot maintain its shape.

In Polio-μ, the amount of % (A) is 5% or more, usually 5-90%, preferably 1%, based on the total weight of Polio-μ.
It is 0-50%. If the amount of (8) is less than 5%, the amount of heat generated during combustion becomes too large to be used. If it exceeds 90%, the amount of smoke will increase.

(B) Noze is 5% or more based on the total weight of the polyol, usually 6 to 80%, preferably 80 to 70%.

If the amount of (B) is less than 5%, the amount of smoke generated will increase. When it exceeds 80%, the compatibility with the halogenated hydrocarbon blowing agent becomes poor, and the resulting foam has poor dimensional stability.

The amount of (C) is usually 5 to 50% based on the total weight of the polyol.
50%, preferably 10-20%. If the amount of (C) is less than 5%, the compatibility with the halogenated hydrocarbon blowing agent is poor and the strength of the foam is reduced. If it exceeds 50%,
The amount of smoke and heat generated during foam combustion increases.

The organic polyisocyanates used in the present invention include aromatic, aromatic aliphatic, distillate, [beta] cyclic polyisocyanates and modified products thereof, tif diphenylmethane diisocyanate, dipheniNmethane diisocyanate, tolylene diisocyanate, etc. isocyanate), crude 1-lylene diisocyanate, xylylene diisocyanate, hexamenane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, triphenylmethylene triisocyanate, tolylene triisocyanate, modified (carposiimide modification etc.) diphenyl remethane diisocyanate and mixtures thereof, as well as N obtained by reacting an excess amount of these polyisocyanates with polyol-/L/ (for example, low-molecular-weight polyol μ and/or polyether polyol-4/).
CO-terminated prepolymer cNcom (e.g. 6-85%) and their combinations are contemplated. Preferred among these is crude diphenono V methane diisocyanate.

These polyisocyanates can also be used as free incyanate-containing prepolymers obtained by reacting excess polyisocyanate and polyol.

The blowing agent used in the present invention is water or a halogenated hydrocarbon, and those commonly used for producing rigid polyurethane foam can be used.

Examples: 'tHacyclodifluoromethane, trichloromonofluoronotane, methylene dichloride, etc.
Among them, trichloromonofluoromethane is preferred.

The amount of the blowing agent used is not particularly limited, but is usually 5 to 50 parts by weight based on the total amount M of the polyol compound and organic polyisocyanate.

As the trimerization catalyst used in the present invention, known ones can be used. Specifically, metal salts of carboxylic acids, such as sodium acetate, lead octylate, zinc octylate, cobalt naphthenate, etc.; alkoxides and phenoxides of alkali and alkaline earth metals, such as sodium methoxide, sodium phenoxide, etc.; tertiary Amines such as triethylamine, triethylenediamine, N-
Methylmorpholine, (dimethylamino)methylphenol, pyridine, etc.; quaternary ammonium bases such as tetraethylammonium hydroxide; imidazoles such as imidazo-A/, 2-ethyA/-4-methylimidazole, etc.; tin and antimony For example, tetraphenyltin, tributyl antimony oxide, etc. can be mentioned. Among these, preferred is a combination system of a metal salt of carboxylic acid and a tertiary amine.

In producing the polyisocyanurate foam in the present invention, the isocyanate index is usually 200-1000.
% is preferably 800-500. If the isocyanate index exceeds 1000, the flame resistance will be good, but it will be brittle and have poor adhesion to the surface material. If the polyisocyanurate foam is less than 200, it exhibits the opposite performance. The production method of the polyisocyanurate foam according to the present invention may be the same as the conventional method, and the compensationer μ method, 70 bath method, spray method, RIM method, etc. can be applied.

〔Example〕

The present invention will be explained below with reference to Examples, but the present invention is not limited thereto. Parts in Examples indicate parts by weight.

Examples 1 to 6 Mixtures of the formulations shown in Table 1 were stirred and mixed for 4 to 8 seconds and mixed in a predetermined mode μ (size 400 x 400 x 200
mm) to obtain a polyisocyanurate foam.

The resulting polyisocyanurate foam had lower smoke and heat generation properties than ordinary polyisocyanurate foam.

Comparative Examples 1 to 6 The mixtures shown in Table 1 were stirred and mixed for 4 to 8 seconds, and mixed in a predetermined mode μ (size 400 x 400 x 20 G mm
) to obtain a polyisocyanurate foam. The obtained polyisocyanurate foam was comparable to ordinary polyisocyanurate foam, and had higher smoke and exothermic properties than the foams of Examples 1 to 6.

Table-1 Table-1 (Continued) (Note 1) Polyol N1 Novolac-based polyol with an OH value of 250 obtained by adding propylene oxide to a novolak-type phenolic resin (pentafunctional) (Note 2) Polyol N2 Novolak-type phenolic resin ( Polyol S1 An aromatic polyester with an OH value of 820 obtained by reacting diethylene glyco-μ with phthalic anhydride y polyol-μ ( Note 4) Polyol T.

Aromatic amine polyol with an OH value of 400 obtained by adding propylene oxide to toluene diamine (Note 5) Polyol-/L/T2 Glycerin-based polyol with a hydroxyl value of 280 obtained by adding ethylene oxide to glycerin (Note 5) 6) Polio-7L/T3 A glycerin-based polyol with a hydroxy value of 56 and 92, obtained by adding propylene oxide to glycerin (Of course) Polio-/L/T4 A glycerin-based polyol with a hydroxyl value of 400 obtained by adding propylene oxide to sucrose. Sucrose-based polio-μ (Note 8) Manufactured by Sanabuchi Co., Ltd. (Note 9) Manufactured by Toray Silicon Co., Ltd. (Note 10) Test piece 80 x 220 x 220 mm (Note 10)
) JIS A 1821 A surface test was conducted among the flame retardant test methods for building interior materials and construction methods.

The test was conducted using a test specimen measuring 80 x 220 x 220 mm.

(Note) A Smoke generation coefficient (Note 12) T-dθ Temperature/time area (°C x minutes) (Note 18) Time for flame to disappear after afterflame heating (seconds) (Note 14) Foam weight after weight retention test XIQO/Foam weight before test (%) (Note 15) Harmful crack deformation of test specimen after crack deformation test (Note 16) Resin premix compatible polyol-y, foam stabilizer, catalyst, trichlorofluoromethane mixture [Effect of the Invention] The present invention provides a polyisocyanurate foam that emits less smoke and generates less heat during combustion than conventional polyisocyanurate foams.

Furthermore, the method of the present invention has good compatibility with the halogenated hydrocarbon blowing agent, and a uniform foam can be obtained.

Since the foam obtained according to the present invention exhibits the above-mentioned effects, it is extremely useful as a heat insulating material for buildings, civil engineering, industrial plants, etc.

Claims (1)

[Claims] 1. In a method for producing a urethane-modified polyisocyanurate foam by reacting an excess organic polyisocyanurate and a polyol in the presence of a blowing agent and, if necessary, a trimerization catalyst and other auxiliary agents, as the polyol (A) a novolac type phenolic resin polyol of 5% or more based on the total weight of the polyols, (B) a polyester polyol of 5% or more based on the total weight of the polyols, and (
C) A method for producing polyisocyanurate foam characterized by using a polyether polyol. 2. 5-90% (A
), 5 to 80% of (B), and 5 to 50% of (C). 3. The manufacturing method according to claim 1 or 2, wherein (A) has an OH value of 100 to 400, (B) has an OH value of 200 to 400, and (C) has an OH value of 80 to 1830. . 4. The manufacturing method according to any one of claims 1 to 3, wherein the polyol has an average OH value of 150 to 350. 5. The manufacturing method according to any one of claims 1 to 4, in which the organic polyisocyanate and polyol are used in amounts such that the isocyanate index is 200 to 1000. 6. The manufacturing method according to any one of claims 1 to 5, wherein (B) is an aromatic polyester polyol.