JPS60229934A - Phenolic foam - Google Patents

Abstract

PURPOSE:A phenolic foam, obtained by expanding a phenolic resin prepared by uniformly incorporating a high-ortho novolak resin with a resol resin, and having remarkably improved strength. CONSTITUTION:A phenolic foam obtained by incorporating (A) a high-ortho novolak resin, prepared by reacting phenol (preferably unsubstituted) with formaldehyde (preferably paraformaldehyde and formalin together) preferably at 1: 0.5-1:1.5 molar ratio in the presence of a weakly acidic catalyst under refluxing, dehydrating the reaction mixture under reduced pressure, and condensing the reactants at >=100 deg.C, and having preferably >=69% combined ortho content and 400-1,000 number-average molecular weight with (B) a resol resin, prepared by condensing phenol with an aldehyde preferably at 1:1-1:3 molar ratio in the presence of an alkaline catalyst, and containing preferably little free phenol and moisture at 1:20-20:1 solid weight ratio between the components (A) and (B), adding an acidic curing agent, foaming agent, etc. thereto, mixing them, casting the resultant mixture into a vessel, and heating, expanding and curing the mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phenol foam whose strength has been significantly improved. More specifically, the present invention relates to a phenol foam made by foaming a phenol resin consisting of a resin and a resol resin.

Phenol foam, which is made by foaming resol resin, generates almost no smoke or harmful gases, and is highly fire and heat resistant.
Moreover, it is useful as a construction material because of its large capacity. Recently, attention has been focused on fire resistance and heat resistance, and a remarkable increase in consumption has been reported in the United States, Yotsuno, and other countries. but,
Such phenol foams have problems such as brittleness, corrosiveness due to curing acids, and lower strength than urethane foams.

In particular, when a filler such as charcoal, talc, or coolite is added, the strength of the phenol foam is significantly reduced, and in severe cases, the strength is less than that before addition, greatly limiting its versatility.

Phenol foam, which is made by foaming novolac resin, is also used, but since this resin is solid, it is difficult to mix uniformly with the foaming agent and hardening agent, and it is difficult to handle, and foam curing requires high temperatures. Furthermore, the strength of such foams is low, there are problems with productivity, and their uses are limited.

Therefore, the present inventors conducted various studies to improve the strength of phenol foam, and found that among novolak resins, phenol foam is semi-solid or solid, so it is difficult to handle, and it also has high reactivity. By using a phenol resin which is a homogeneous mixture of a high-alternative gelatin resin and a resol resin, which cannot be molded into a foam by itself, the inventors have discovered a phenofoam whose strength is significantly improved, and has thus arrived at the present invention.

Ortho bond ratio (total of methylol groups bonded to the benzene nucleus, alkylated methylol groups, and their condensed bond groups) is 40 to 50% in ordinary random novolaks, but it is more than 50%, especially more than 70%. Since it was reported that a novolac resin with an ortho bond ratio of Various manufacturing methods for lac resins have been developed. Generally, it is produced by carrying out a reflux reaction under a weak acidic catalyst and then heating and concentrating it to form a resin. However, in the present invention, there are no restrictions on the use of resins produced by these production methods. It's not something you can do.

The orsonoporac resin of the present invention preferably contains phenol and formaldehyde in a molar ratio of i, o: o, s.
~1.0:1.5, preferably 1.0:0.7-1
．． Produced at a ratio of 0:1.0. The phenol used is preferably unsubstituted, but meta-substituted phenols having lower alkyl groups, halogens, alkoxy groups, mercapto groups, etc. are also used.

Formaldehyde is not particularly limited, but it is desirable to use paraformaldehyde and formalin in combination because it is necessary to increase the catalytic effect during the reaction, control heat generation, and conduct a homogeneous reaction.

There are methods that use organic solvents to perform homogeneous reactions, but
In order to form a foam, it is necessary to remove #1 almost completely at the end of the reaction, and if the solvent remains, it is undesirable as it will cause curing delay and foam breakage during foam molding. The catalyst usually used is a divalent metal salt with a weak acid. Divalent metal salts include zinc oxide, manganese oxide, barium oxide, calcium oxide, zinc acetate, barium acetate, manganese nitrate,
It is selected from zinc borate, zinc chloride, etc., and has the effect of ortho-orienting the methylol groups in the product. Further, after the orthomethylol compound is produced, a weak acid is added to the system to make - a weakly acidic region so that the condensation reaction can easily occur. Weak acids include salicylic acid, phthalic acid, naphthenic acid, benzoic acid,
It is selected from among oxalic acid, etc. After addition of a catalyst and a weak acid, a reflux reaction is carried out, dehydration is carried out under reduced pressure, and a condensation reaction is carried out at a temperature of 100° C. or higher at which ortho-para selectivity disappears, thereby producing a high-alternative gilac resin. The high ortholac resin used in the present invention has an ortho bond ratio of 6.
The number average molecular weight is preferably 0.0 or more and a number average molecular weight of 400 to 1000.

As the resol resin, one manufactured by a known method is used. Phenol, cresol, xylenol, trimethylphenol, p-butylphenol, p-cyclohexylphenol, p-phenylphenol, p-phenoxyphenol, p- Phenols such as methoxyphenol and p-chlorophenol and aldehydes such as formaldehyde, acetaldehyde and paraformaldehyde are mixed, preferably at a molar ratio of phenol and aldehyde of 1.0:1.0.
~1. It is an acid-curable resol type phenolic resin obtained by condensation in the range of O
00-1000. Non-volatile solid content 75-85 inches, viscosity (2
5° C.) 500 to 10,000 centipoise resol resin.

In the present invention, the phenolic resin consisting of the high-ortho-novolac resin Tresol resin is usually diluted with a solvent when the high-ortho-novolac resin is used as a semi-solid or solid resin. However, since the resol resin acts as a diluent, it has excellent foaming properties, curability, etc., which makes it impractical due to problems with curability. In particular, the ratio of dilution with resol resin, curing properties, and foam molding conditions can be freely controlled, and it is also possible to achieve higher strength than conventional phenol foam.

In the present invention, the solid content weight ratio of Hyorun Nogolac resin (1) and resol resin is preferably 1:20 to 2.
The ratio is 0:1, more preferably 1:1o to 1:1. If the ratio of high-alternative gelatin resin is /J%, the effect of increasing the strength will be small, and if it is too high, the viscosity will become high and difficult to handle with ib, as in the case of only high-alternative gelatin resin, which is not preferred.

The above-mentioned foam resin is cured in the presence of an acidic curing agent, and such a curing agent can be a strong acidic compound that is generally used in curing phenol foam. For example, inorganic acids include Lewis acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc.; organic acids include sulfonated aromatic compounds such as phenolsulfonic acid, toluenesulfonic acid, xylene sulfonic acid, etc., and these may be used alone or in combination. The above may be used in combination. The concentration and amount of the curing agent added are determined depending on the reactivity of the phenolic resin for foam, and are generally 5 to 30% by weight based on the phenolic resin for foam.

In producing the phenol foam of the present invention,
It is necessary to add a blowing agent and a foam stabilizer to the phenolic resin for foam in addition to an acidic curing agent.The blowing agent is a compound with a low boiling point, such as a low molecular weight hydrocarbon, n-hebutane, alcohol, petroleum ether, or fully or completely halogenated hydrocarbons, methylene chloride, carbon tetrachloride, trichlorofluoromethane, 1,1,2-)lychlor-1,2,2-
) refluoroethane, etc. These compounds can be used alone or in combination. The amount of blowing agent is determined by the desired density between 5 and 25% by weight of the foam phenolic resin.

Further, in order to help stabilize the fine bubbles of the foam, a foam stabilizer is used in an amount of 0.1 to 5% by weight, preferably 0.5 to 2% by weight, based on the phenolic resin for the foam. Such foam stabilizers are selected from condensation products of alkylene oxide and alkylphenol, polysiloxane and polyoxyalkylene copolymers, sorbitan monolaurate, polyethylated glycerides, and the like.

In addition to the above-mentioned additives, the phenol foam of the present invention includes basic powder substances such as calcium carbonate, barium carbonate, calcium oxide, barium oxide, Merck, mica, pearlite particles, shirasu balloons, etc. to neutralize the acidic curing agent. Other inorganic fillers can be mixed.

Is the phenol form of the present invention normally used?
A mixture of foam phenolic resin consisting of lac resin and resol resin, an acidic curing agent, a foaming agent, a foam stabilizer, and other additives is stirred for a predetermined period of time, and the resulting mixture is poured into a container and heated to foam and harden. Well-manufactured and usually has a density of 25~
60 kg/m”.

Production Example 1 () Production of Iorsono Lac Resin) Phenol 1410g, 80 tiparaform 281g 141% formalin 217g, zinc oxide 1.8g, benzoic acid 3.0
A reflux reaction was carried out in the presence of g, and after dehydration under reduced pressure, the condensation reaction was further advanced at 115°C to obtain an ortho bond ratio of 70%, free phenol 10%, number average molecule z6ooa...Iortho Nozelac tree 1! 145 (l) of (I) was obtained.

Production Example 2 (same as above) The reaction was carried out in the same manner as in Production Example 1, and the ortho bond ratio was 72%.
1300Ii of high-ortho-Nobilac resin (manufactured by Co., Ltd.) with 0 free phenol and a number average molecular weight of 800 was obtained.

Production Example 3 (Production of low ortholac resin) After reflux reaction in the presence of 940 g of phenol, 568 g of 37% formalin, and 9.4 g of oxalic acid, dehydration under reduced pressure and removal of phenol were performed, resulting in an ortho bond ratio of 45%, free phenol of 9%, Random novolac resin with number average molecular weight 640 is 1050.9
Obtained.

Production Example 4 (Production of resol resin) After reaction at 75°C in the presence of phenol 880p, 37% formalin 1140y1 and sodium hydroxide 3.3.9, dehydration was carried out under reduced pressure, resulting in a non-volatile content of 75% and a viscosity of 600 cps (2
5℃), a resol resin with a number average molecular weight of 400 was heated to 105℃ (
I got it.

Examples 1-3. Comparative Examples 1 to 3 The random novolac resin (1) produced in Production Examples 1 and 2) or the random novolac resin produced in Production Example 3 (IO and the resol resin produced in Production Example 4 were mixed in the formulation shown in Table I) Mix and further blowing agents, fillers, and curing acids in Table I
Add in the proportion shown, mix thoroughly, and pour into a container.
A foam was obtained by foaming and curing at approximately 60° C. for 15 minutes. Its physical properties are also shown in Table I.

Claims (1)

[Claims] Phenol foam is made by foaming phenolic resin consisting of high-altitude gelatin resin and resol resin.