JP2009293033A - Phenolic resin foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phenolic resin foam having an excellent heat-insulating performance and an excellent mechanical strength such as compression strength, and improving brittleness by using as a foaming agent a hydrocarbon with low global warming potential and less risk of ozone layer destruction. <P>SOLUTION: A phenolic resin foam has a closed-cell content of 80% or more, an average cell diameter of 10 μm or more and 400 μm or less, and density of 10 kg/m<SP>3</SP>or more and 70 kg/m<SP>3</SP>or less, contains a hydrocarbon in the closed cells, and consists of a phenolic structure having a urea-crosslinked structure. The phenolic resin foam has brittleness of 20% or less, compression strength of 0.5 kg/cm<SP>2</SP>or more, and heat conductivity of 0.025 kcal/mhr°C or less. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a phenol resin foam for heat insulation suitable as various building materials.

  Phenolic resin foams are widely used as various building materials because they are excellent in flame retardancy, heat resistance, low smoke generation, dimensional stability, solvent resistance, and processability among organic resin foams. Yes. Generally, a phenol resin foam is produced by uniformly mixing a resole resin obtained by condensing phenol and formalin with an alkaline catalyst, a foaming agent, a surfactant, a curing catalyst, and other additives and foaming.

  Conventional phenol resin foams include, as a blowing agent, trichlorotrifluoroethane (CFC-113), trichloromonofluoromethane (CFC-11), dichlorotrifluoroethane (HCFC-123), dichlorofluoroethane (HCFC-141b) and the like. Halogenated hydrocarbons and their derivatives have been used. As a foaming agent, these halogenated hydrocarbons and their derivatives are superior in safety during production, and further, since the thermal conductivity of the gas itself is low, the thermal conductivity of the obtained foam can be lowered. Had.

  At present, however, substances containing chlorine atoms, such as CFC-113 and CFC-11, have been shown to decompose ozone in the stratosphere and cause destruction of the ozone layer. As a cause of environmental destruction, it has become a global problem, and their production and use have been globally regulated. In addition, 1,1,1,2-tetrafluoroethane (HFC-134a) and 1,1-difluoroethane (HFC-152a), which are fluorohydrocarbons that do not contain chlorine and have an ozone depletion coefficient of 0, are also global warming. Since the coefficient is relatively large, use in Europe has been limited, so hydrocarbons such as pentane have attracted attention as blowing agents.

  Conventionally, it has been known that hydrocarbons such as normal pentane and cyclopentane are used as blowing agents for phenolic resin foams, but these hydrocarbons do not destroy the ozone layer and have a global warming potential. However, compared to halogenated hydrocarbons, the closed cell ratio of the resulting phenolic resin foam also decreases, and the heat conductivity of the gas itself is high, so good heat insulation performance cannot be obtained. Further, there were practical problems such as insufficient mechanical strength such as compressive strength.

The present invention can solve the above-mentioned problems of conventional phenol resin foams. That is, an object of the present invention is to provide a phenol resin foam that is a hydrocarbon foaming agent, has excellent heat insulation performance, is excellent in mechanical strength such as compressive strength, and has improved brittleness.
In order to achieve the object of the present invention, the present inventors have prepared the production conditions of a phenol resin foam, for example, the molar ratio of formaldehyde and phenol charged at the time of resole resin polymerization, the molecular weight of the resole resin, the catalyst amount, As a result of extensive examination of foaming conditions such as foaming temperature, it has been found that a phenol resin foam having a specific cell form and a specific resin cross-linked structure can achieve the object of the present invention, and completes the present invention. It came to.

That is, this invention is the following phenol resin foam.
1. It has a closed cell ratio of 70% or more, an average bubble diameter of 10 μm or more and 400 μm or less, a density of 10 kg / m ³ or more and 70 kg / m ³ or less, containing hydrocarbons in the closed cells, and from the pyrolysis pattern of pyrolysis gas chromatography A phenol resin foam characterized in that the required area ratio C (C = A / B) of trimethylphenol A to phenol B of the thermal decomposition product is in the range of the following formula (1).
0.05 ≦ C ≦ 4.0 (1)
2. The area ratio F (F = D / E) of the component D derived from urea crosslinking of the pyrolysis product to the phenol derivative component E determined from the pyrolysis pattern of pyrolysis gas chromatography is in the range of the following formula (2). The phenolic resin foam according to item 1 above.
0.01 ≦ F ≦ 0.3 (2)

3. 3. The phenol according to item 1 or 2, wherein the hydrocarbon in the closed cell is composed of one or more types of hydrocarbons, and at least one of the hydrocarbons is a saturated hydrocarbon having 4 to 6 carbon atoms. Resin foam.
4). 4. The phenol resin foam according to item 3, wherein the saturated hydrocarbon is isobutane, normal butane, cyclobutane, normal pentane, isopentane, cyclopentane, or neopentane.
5. The hydrocarbon in the closed cell is a mixture of 5 to 95% by weight of butanes selected from isobutane, normal butane and cyclobutane and 95 to 5% by weight of pentanes selected from normal pentane, isopentane, cyclopentane and neopentane. 3. The phenolic resin foam according to 1 or 2 above.

6). 6. The phenol resin foam according to item 5 above, wherein the hydrocarbon in the closed cells is a mixture of 5 to 95% by weight of isobutane and 95 to 5% by weight of normal pentane.
7). It has a closed cell ratio of 80% or more, an average cell diameter of 10 μm or more and 400 μm or less, a density of 10 kg / m ³ or more and 70 kg / m ³ or less, comprising a hydrocarbon in the closed cells and a phenol resin structure having a urea cross-linking structure. A phenol resin foam having a brittleness of 20 % or less, a compressive strength of 0.5 kg / cm ² or more, and a thermal conductivity of 0.025 kcal / mhr ° C. or less.
8). 3. The phenol resin according to item 1 or 2, which contains 0.01 to 10% by weight of a high-boiling point aliphatic hydrocarbon, a high-boiling point alicyclic hydrocarbon or a mixture thereof based on the phenol resin foam. Foam.

（式中、ａは０、１、２、３であり、ｂは３−ａであり、ｍおよびｎは、それぞれ１以上の整数である。）
１０．下記一般式（II）で示されるフルオロアミンの少なくとも１種をフェノール樹脂発泡体に対して０．０１〜５重量％含有することを特徴とする前項１又は２記載のフェノール樹脂発泡体。
（Ｃ_cＦ_d）₃Ｎ （II）
（式中、ｃは４以上の自然数であり、ｄは２ｃ＋１である。） 9. 3. The phenol resin foam according to item 1 or 2, which contains 0.01 to 5% by weight of at least one fluoroether represented by the following general formula (I) with respect to the phenol resin foam.

(Wherein, a is 0, 1, 2, 3; b is 3-a; and m and n are each an integer of 1 or more.)
10. 3. The phenol resin foam according to item 1 or 2, which contains 0.01 to 5% by weight of at least one fluoroamine represented by the following general formula (II) based on the phenol resin foam.
(C _c F _d ) ₃ N (II)
(In the formula, c is a natural number of 4 or more, and d is 2c + 1.)

  The phenol resin foam according to the present invention has excellent heat insulation performance, excellent mechanical strength such as compressive strength, and surface brittleness is remarkably improved.

FIG. 1 is an example of a pyrolysis gas chromatography pyrogram of a phenolic resin foam sample according to the present invention. FIG. 2 is an example of the mass spectrum of one structural component derived from urea crosslinking (the component of peak 7 in FIG. 1) in the pyrolysis gas chromatography pyrogram of the phenol resin foam sample of the present invention. FIG. 3 is an example of a mass spectrum of one urea-crosslinking-derived structural component (component of peak 8 in FIG. 1) of a pyrolysis gas chromatography pyrogram of a phenol resin foam sample according to the present invention. FIG. 4 is an example of the mass spectrum of one structural component derived from urea crosslinking (the component of peak 9 in FIG. 1) in the pyrolysis gas chromatography pyrogram of the phenol resin foam sample of the present invention. FIG. 5 is an example of the mass spectrum of one structural component derived from urea crosslinking (the component of peak 10 in FIG. 1) in the pyrolysis gas chromatography pyrogram of the phenol resin foam sample of the present invention. FIG. 6 is an example of a mass spectrum of one urea crosslinking-derived structural component (component of peak 11 in FIG. 1) in a pyrolysis gas chromatography pyrogram of a phenol resin foam sample according to the present invention.

Hereinafter, the present invention will be described in detail.
In this invention, it is necessary to make the structure | tissue of a phenol resin foam into a specific structure | tissue.
In the phenol resin foam according to the present invention, the closed cell ratio is 70% or more, preferably 80% or more, and more preferably 90% or more. If the closed cell ratio is less than 70%, not only the foaming agent of the phenol resin foam may be replaced with air, but the thermal insulation performance may be significantly deteriorated over time, and the surface brittleness of the foam may increase and mechanical There is a concern that practical performance will not be satisfied. The upper limit of the closed cell ratio is preferably 99.3% or less.

The average cell diameter of the phenol resin foam in the present invention is 10 μm or more and 400 μm or less, preferably 15 μm or more and 300 μm or less, and particularly preferably 20 μm or more and 150 μm or less. If the average cell diameter is less than 10 μm, there is a limit to the thickness of the cell wall, which inevitably increases the foam density, resulting in an increase in the heat transfer rate of the resin part in the foam and the phenol resin foam. There is a risk that the heat insulation performance of will be insufficient. On the other hand, if the bubble diameter exceeds 400 μm, heat conduction due to radiation increases, and the heat insulating performance of the foam deteriorates.
The density of the foam in the present invention is from 10 kg / m ^{3 to} 70 kg / m ³ , more preferably from 20 kg / m ^{3 to} 50 kg / m ³ . When the density is less than 10 kg / m ³ , the mechanical strength such as compressive strength is reduced, the material is easily damaged during handling, and the surface brittleness is also increased. On the contrary, when the density exceeds 70 kg / m ³ , there is a concern that the heat transfer of the resin portion increases and the heat insulation performance is lowered.

  In the present invention, it is necessary to form the phenol resin foam with a specific resin cross-linked structure. In the present invention, pyrolysis gas chromatography is used as a means for indirectly measuring the crosslinked structure of the resin. The area of each component of trimethylphenol and phenol appearing in the pyrolysis gas chromatography pyrogram when using a phenol resin foam as a sample does not directly indicate the structure of the phenol resin foam, but indirectly It can be an effective index reflecting the structure of the polymer constituting the phenol resin foam. In the present invention, the area ratio C value of trimethylphenol A to phenol B in the pyrogram (C = A / B) is used as an index that indirectly reflects the crosslink density of the methylene structure or methyl ether structure of the phenol resin. . If there are many methylene bridges or methyl ether bridges in the phenolic resin, the C value increases. Conversely, if there are few methylene bridges or methyl ether bridges, the C value decreases.

  In the present invention, the C value needs to be 0.05 or more and 4.0 or less. The resin cross-linked structure is preferably from 0.1 to 2.0, more preferably from 0.1 to 1.0. The inventors adjusted the molecular weight distribution of the resole resin, the charging ratio of formaldehyde and phenol at the time of polymerization, and the foaming conditions so that the C value falls within this range. That is, the charging ratio of formaldehyde and phenol during polymerization is preferably 1.3 to 3.0, more preferably 1.5 to 2.5, and the molecular weight of the resole resin is the viscosity of the resole resin composition at 40 ° C. Is adjusted to be in the range of 1000 to 50000 cps so that the temperature in the mixer during foaming does not exceed 80 ° C. Thus, when the molecular weight distribution of the resole resin, the charging ratio of formaldehyde and phenol at the time of polymerization, and the foaming conditions are adjusted, the strength and foaming characteristics of the resin of the obtained foam are remarkably improved, and the hydrocarbon foaming agent It has been found that a phenolic resin foam excellent in heat insulation performance and mechanical strength can be obtained even when using.

In the present invention, when the C value exceeds 4.0, as is apparent from Comparative Example 2 described later, the foam is fragile and the practical performance may be insufficient. Furthermore, there is a possibility that inconveniences such as the foaming ratio does not increase due to the viscosity of the resin being too high during foam production. On the other hand, when the C value is less than 0.05, as is apparent from Comparative Example 3 described later, the compressive strength and the like of the phenol resin foam decreases.
Furthermore, the present inventors have found that the strength of the phenol resin foam is further improved when a urea cross-linked structure is formed in the phenol resin. Similarly to the C value, the index indicating the urea cross-linking structure is also determined by the area ratio of the components appearing in the pyrogram of the pyrolysis gas chromatography of the foam sample. The present inventors have found that the area ratio F value (F = D / E) of the component D derived from urea crosslinking to the phenol derivative component E is an indicator of the density of the urea crosslinked structure of the phenol resin.

In the present invention, the component D derived from urea crosslinking is a component released from the retention time of 8 to 18 minutes under the measurement conditions described later in the pyrogram, and includes a phenyl group and an isocyanate (—NCO in the molecule). ) Group-containing compounds. Specifically, peaks 7 to 11 in FIG. 1 and the corresponding mass spectra are shown in FIGS. 2 to 6, respectively. Let D be the sum of the areas from peaks 7 to 11.
The phenol derivatives in the present invention are phenol, 2-methylphenol, 4-methylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, and 2,4,6-trimethylphenol. Peaks 1 to 6 in the figure. In the present invention, E is the total area of these pyrograms. The F value is preferably 0.01 or more and 0.3 or less, and more preferably 0.02 or more and 0.2 or less. When the F value is less than 0.01, no significant improvement in the strength of the phenol resin foam is observed, and when the F value exceeds 0.3, the strength decreases.

The phenol resin foam according to the present invention is greatly improved in brittleness and compressive strength as compared with the phenol resin foam of the conventional hydrocarbon foaming agent. Furthermore, the brittleness is significantly improved when the urea cross-linking structure is optimized. As a result, it is expected that the use range of the conventional phenol resin foam will be expanded even in applications where its use is restricted due to its brittleness.
The phenol resin foam of the present invention has a brittleness of 30% or less, more preferably 20% or less, according to the measurement method described later. If the brittleness exceeds 30%, not only the resin powder with the foam surface shaved increases but the workability at the time of construction deteriorates, there is a problem that the product is easily damaged during handling such as transportation and construction. The lower limit of brittleness is preferably 1% or more. The compressive strength is 0.5 kg / cm ² or more, more preferably 1.0 kg / c.
m ² or more. When the compressive strength is less than 0.5 kg / cm ² , it is not only easily damaged during construction, but also its use range is limited due to its low mechanical strength. The upper limit of the compressive strength is preferably 20 kg / cm ² or less. Brittleness and compressive strength are closely related to the closed cell ratio, average cell diameter, density and strength of the resin itself of the phenol resin foam. In the present invention, the resin itself forming the phenol resin foam is specifically crosslinked. By forming the structure, the strength of the resin can be improved, and the brittleness and compressive strength of the resin foam can be remarkably improved.

  As the foaming agent in the present invention, hydrocarbons can be used, but cyclic or chain alkanes, alkenes and alkynes having 3 to 7 carbon atoms can be preferably used. Furthermore, an alkane or cycloalkane having 4 to 6 carbon atoms is more preferable from the viewpoints of chemical stability and thermal conductivity. Specific examples include normal butane, isobutane, cyclobutane, normal pentane, isopentane, cyclopentane, neopentane, normal hexane, isohexane, 2,2-dimethylbutane, 2,3-dimethylbutane, and cyclohexane. Among them, normal butane, isobutane, cyclobutane butanes and normal pentane, isopentane, cyclopentane, neopentane pentanes are particularly suitable for the present invention.

  In the present invention, two or more of these hydrocarbons can be mixed and used. Specifically, a mixture of 5 to 95% by weight of pentanes and 95 to 5% by weight of butanes, more preferably 25 to 75% by weight of pentanes and 75 to 25% by weight of butanes is good in a wide temperature range. It is particularly preferable because of its excellent heat insulating properties. Among them, the combination of normal pentane and isobutane has excellent heat insulation in a wide range from a low temperature region (for example, a heat insulating material for a freezer at about −80 ° C.) to a high temperature region (for example, a heat insulating material for a heating body at about 200 ° C.). It is particularly preferable because performance can be secured and these compounds are relatively inexpensive and economically advantageous.

  Also, fluorocarbons such as perfluorobutane, perfluorocyclobutane, perfluoropentane, perfluorocyclopentane, perfluorohexane, perfluorocyclohexane, perfluoroheptane, perfluorocycloheptane, perfluorooctane and perfluorocyclooctane are foamed. Sometimes mixed and used. Furthermore, low boiling point substances such as nitrogen, helium, argon, and air can be used as foaming nuclei dissolved in a foaming agent. The amount of the foaming agent used in the present invention may be arbitrarily selected depending on the desired density of the foam, foaming conditions, etc., but is usually preferably 3 to 40 parts by weight with respect to 100 parts by weight of the resin. More preferably, it is 5 to 30 parts by weight.

The phenol resin foam according to the present invention has excellent heat insulation performance with a thermal conductivity of 0.025 kcal / mhr ° C. or less, while the foaming agent is a hydrocarbon. A more preferable thermal conductivity is 0.020 kcal / mhr ° C. or less. The lower limit of the thermal conductivity is preferably 0.012 kcal / mhr ° C. or higher.
Furthermore, the present inventors have found that when a high-boiling point aliphatic hydrocarbon or high-boiling point alicyclic hydrocarbon or a mixture thereof is present during foaming, a better phenolic resin foam is formed. The high boiling point aliphatic hydrocarbon or high boiling point alicyclic hydrocarbon of the present invention or a mixture thereof has an ordinary boiling point of 150 ° C. or higher at 1 × 10 ⁵ Pa and mainly has an alkane structure or a cycloalkane structure. The hydrocarbon is preferably, and specific examples include solid paraffin, liquid paraffin, mineral spirit, low molecular weight polyethylene, and low molecular weight polypropylene. Solid paraffin, also called paraffin wax, has a carbon number ranging from 16 to 60 and is mainly composed of normal paraffin, but many contain isoparaffin and naphthene, and the melting point usually varies from 35 ° C to 80 ° C. Liquid paraffin is a hydrocarbon oil having a pour point of −20 ° C. or higher and a relatively light lubricating oil fraction, for example, a spindle oil fraction, highly purified by washing with sulfuric acid. Ingredients. Mineral spirit is also called petroleum spirit and is defined in Japanese Industrial Standard K2201 (Industrial Gasoline Standard) No. 4.

In the present invention, the amount of the high-boiling point aliphatic hydrocarbon or high-boiling point alicyclic hydrocarbon or a mixture thereof is 0.01% by weight to 10% by weight, more preferably based on the phenol resin foam. 0.05 wt% to 5 wt%. When the amount of the high-boiling point aliphatic hydrocarbon or high-boiling point alicyclic hydrocarbon or a mixture thereof is less than 0.01% by weight, there is almost no effect. If the weight exceeds 10% by weight, the high-boiling point aliphatic hydrocarbon, the high-boiling point alicyclic hydrocarbon, or a mixture thereof is liquefied in the bubbles and the heat insulation performance is lowered, or the resin rigidity is lowered. There is a concern to do.
The presence of high boiling aliphatic hydrocarbons or high boiling alicyclic hydrocarbons or mixtures thereof during foaming makes the foam of the phenolic resin foam smaller and more uniform, thereby improving the thermal insulation performance of the phenolic resin foam. There is an effect to improve.

（式中、ａは０、１、２、３であり、ｂは３−ａであり、ｍおよびｎは、それぞれ１以上の整数であり、より好ましくは１以上１０以下である。） The present inventors have also found that a good phenol resin foam can be obtained if fluoroether is present during foaming. The fluoroether of the present invention is a fluoroether having a perfluoropropyl ether structure and a fluoromethylene structure in the molecule represented by the following general formula (I), for example, perfluoropolyethers manufactured by Augmont Co., Ltd. A certain Galden HT-70, Galden HT-55, etc. can be used preferably.

(Wherein, a is 0, 1, 2, 3; b is 3-a; and m and n are each an integer of 1 or more, more preferably 1 or more and 10 or less.)

The use amount of the fluoroether of the present invention is 0.01% to 5% by weight, more preferably 0.05% to 3% by weight, based on the phenol resin foam. If the amount of fluoroether is less than 0.01% by weight, the effect cannot be obtained.
In addition, if the amount of fluoroether exceeds 5% by weight, not only the manufacturing cost increases but also economically disadvantageous, the specific fluoroether is liquefied in the bubbles to lower the heat insulation performance, and the rigidity of the resin There is a concern about the decline.
When the fluoroether in the present invention is used alone as a foaming agent, the fluoroether is abruptly separated from the resin phase at the time of foaming and a foam is not obtained, resulting in a phenol resin mass. This is because the fluoroether in the present invention is different from the specific polyfluoroethers and the specific fluorinated ethers used in JP-A-3-231941 and JP-A-4-202242. This is because it has no foaming function.

In the present invention, by using hydrocarbon as a foaming agent and coexisting fluoroether during foaming, the cell diameter of the phenol resin foam is reduced, thereby improving the heat insulation performance.
In addition, since the fluoroether according to the present invention has oxygen in the molecule, the lifetime in the atmosphere is shortened compared to perfluoroalkanes, and the global warming potential is relatively small. You can expect the benefits to say.
Furthermore, the present inventors have also found that a good phenol resin foam can be obtained when a fluoroamine represented by the following general formula (II) is present during foaming.
(C _c F _d ) ₃ N (II)
(In the formula, c is a natural number of 4 or more, more preferably a natural number of 4 or more and 16 or less. D is 2c + 1.)

The fluoroamine in the present invention has a high boiling point and does not function as a foaming agent. Specifically, Fluorinert FC-43 (triperfluorobutylamine), FC-70 (triperfluoroamylamine), FC-71 (triperfluorohexylamine) manufactured by Sumitomo 3M Limited may be preferably used.
In the present invention, the amount of fluoroamine used must be 0.01% to 5% by weight, more preferably 0.05% to 3% by weight, based on the phenol resin foam. If the amount of fluoroamine is less than 0.01% by weight, the effect cannot be obtained. In addition, if the amount of fluoroamine used exceeds 5% by weight, not only the production cost increases but also economically disadvantageous, fluoroamines are deposited on the cell walls and the heat insulation performance is reduced, and the rigidity of the resin is reduced. There is a concern about the decline.

  Since the fluoroamine in the present invention has a high boiling point, it does not have a foaming function as a foaming agent. Therefore, when the fluoroamine in the present invention is used alone as a foaming agent, there is no foaming at all. However, when the fluoroamine according to the present invention is present in the foamable composition at the time of foaming the phenol resin, it functions suitably for the formation of the structure of the cell part and the resin part of the phenol resin foam. That is, in the present invention, by using hydrocarbon as a foaming agent and coexisting fluoroamine at the time of foaming, the cell diameter of the phenol resin foam is reduced. Therefore, the phenol resin foam according to the present invention has a heat insulation performance. It will be improved.

Next, the manufacturing method of the phenol resin foam by this invention is demonstrated.
The resol resin for producing the phenol resin foam is polymerized by heating phenol and formalin as raw materials in the temperature range of 40 ° C. to 100 ° C. with an alkali catalyst. At that time, replacing part of the raw material phenol with saligenin is effective in controlling the C value. That is, as the molecular weight of the resole resin is increased, the C value tends to increase. However, when the molecular weight is increased too much, the viscosity of the resole resin increases rapidly, making it difficult to handle. When saligenin is used as a substitute or partial substitute for phenol, it is possible to obtain a phenol resin foam having a large C value, that is, a high crosslink density, while being a low-molecular resol resin that is easy to handle. In the case of introducing a urea cross-linked structure, it is possible to adjust the resole resin reacted with urea by adding urea at the time of resole polymerization. It is better to react by heating. The amount of methylolated urea in the resol resin composition is usually 1 to 40% by weight, preferably 2 to 30% by weight, based on the resol resin. The resol resin composition is used with a desired viscosity by adjusting the water content. Although the suitable viscosity of a resin composition changes with foaming conditions, the viscosity in 40 degreeC becomes like this. Preferably it is 1000-50000 cps, More preferably, it is 2000-30000 cps.

  Resole resin composition adjusted to proper viscosity, foaming agent, surfactant, curing catalyst, if necessary, high boiling aliphatic hydrocarbon, high boiling alicyclic hydrocarbon or mixture thereof, fluoro Ether, fluoroamine and other additives can be introduced into a mixer and mixed uniformly to obtain a foamable composition. At that time, the surfactant may be mixed with the resin in advance and introduced into the mixer, or these may be separately introduced into the mixer. However, if the curing catalyst is mixed with the resole resin in advance, the curing reaction proceeds before foaming and a good foam cannot be obtained. Therefore, it is desirable to mix the resole resin and the curing catalyst with a mixer. In addition, when using high-boiling point aliphatic hydrocarbons, high-boiling point alicyclic hydrogen or mixtures thereof, fluoroethers, fluoroamines, these are mixed with a resol resin in advance and introduced into a mixer. Alternatively, it may be supplied alone to the mixer, but it is more effective and preferable if it is dissolved in a foaming agent and introduced into the mixer. The foamable composition obtained by mixing with a mixer is poured into a mold or the like, and the foam curing is completed by heat treatment to obtain a phenol resin foam.

  As a curing catalyst for foam curing, aromatic sulfonic acids such as toluene sulfonic acid, xylene sulfonic acid, benzene sulfonic acid, phenol sulfonic acid, styrene sulfonic acid and naphthalene sulfonic acid can be used alone or in combination of two or more. . Resorcinol, cresol, saligenin (o-methylolphenol), p-methylolphenol, etc. may be added as a curing aid. These curing catalysts may be diluted with a solvent such as diethylene glycol or ethylene glycol.

  As the surfactant used in the present invention, any of those effective for producing a phenol resin foam can be used. Among these, nonionic surfactants are effective. For example, alkylene oxide which is a copolymer of ethylene oxide and propylene oxide, condensates of alkylene oxide and castor oil, alkylene oxide and nonylphenol, dodecylphenol, and the like. Condensation products with alkylphenols, fatty acid esters such as polyoxyethylene fatty acid esters, silicone compounds such as polydimethylsiloxane, polyalcohols, and the like. These surfactants may be used alone or in combination of two or more. Moreover, although there is no restriction | limiting in particular also about the usage-amount, in this invention, it is preferably used in 0.3-10 weight part per 100 weight part of resole resin.

Next, a method for evaluating the structure, structure, and characteristics of the phenol resin foam in the present invention will be described.
The average cell diameter of the foam in the present invention means that a straight line having a length of 9 cm is drawn on a 50 times magnified photograph inside the foam, and the number of bubbles crossed by each straight line is obtained by each straight line. It is a value obtained by dividing 1800 μm by the value (the number of cells measured according to JIS K6402).
The density is a value obtained by measuring a weight and an apparent volume by removing a face material and a siding material of a 20 cm square phenol resin foam sample, and was measured according to JIS K7222.

The closed cell ratio was measured as follows. A cylindrical sample with a diameter of 35 to 36 mm punched from a phenolic resin foam with a cork borer is cut to a height of 30 to 40 mm, and the sample volume is measured by the standard method of using an air-comparing hydrometer 1000 (manufactured by Tokyo Science). To do. The value obtained by subtracting the volume of the bubble wall calculated from the sample weight and the resin density from the sample volume was divided by the apparent volume calculated from the outer dimension of the sample, and measured according to ASTM D2856. However, the density of the phenol resin was 1.27 g / cm ³ .
The thermal conductivity was measured with a 200 mm square sample, a low temperature plate of 5 ° C., and a high temperature plate of 35 ° C. according to the JIS A1412 flat plate heat flow meter method.

  Test specimens for the brittleness test were prepared by cutting 12 cubes each having a side of 25 ± 1.5 mm so as to include a molding skin or face material on one side. However, the thickness of the test piece when the thickness of the foam was less than 25 mm was the thickness of the foam. Place 24 smoked cubes with a side of 19 ± 0.8mm and 12 specimens, dried at room temperature, in a smoked wooden box with an internal dimension of 191 x 197 x 197mm that can be sealed so that dust does not come out of the box. Rotate 600 ± 3 at a speed of 60 ± 2 revolutions per minute. After completion of rotation, the contents of the box are transferred to a net with a size of 9.5 mm, screened to remove small pieces, the weight of the remaining specimen is measured, and the rate of decrease from the specimen weight before the test is calculated. Is brittle and measured according to JIS A9511.

The compressive strength was measured according to JIS K7220 with a specified strain of 0.05.
Pyrogram measurement of pyrolysis gas chromatography was performed as follows. The phenol resin foam sample used for the measurement was further carefully pulverized with a mortar from the foam core portion from which the face material and siding material had been removed, and 0.3 to 0.00 per measurement. The sample amount was 4 mg. As the thermal decomposition apparatus, PY2010D manufactured by Frontier Laboratories, which is a heating furnace type thermal decomposition apparatus, was used. The thermal decomposition temperature was 670 ° C. Gas chromatography measurement was performed by using Hewlett Packard HP5890A type non-polar liquid phase capillary column (Durabondo DB-1 (inner diameter 0.25 mm, film thickness 0.25 μm, length 30 m)). The carrier gas was helium (He), the total flow rate was 100 cc / min, the head pressure was 100 kPa, the oven temperature was started from 50 ° C., increased to 340 ° C. at a speed of 20 ° C. per minute, and held for 15.5 minutes.
Each component was detected with a flame ionization detector (FID), and the area value of each peak was normalized with all the detected components to obtain the ratio of each component. However, when the peaks were overlapped, a perpendicular line was drawn from the valley of the peak overlap to the base line, and the area surrounded by the base line and the perpendicular line was defined as the peak area.

An example of a gas chromatogram of a phenolic resin foam sample according to the present invention is shown in FIG. The structure of each component was confirmed by a mass spectrum obtained by introducing the components separated by gas chromatography into a mass spectrometer. Mass spectra were measured by JEOL JMS AX-505H by an electron impact ionization method (EI method) at an ionization voltage of 70 eV and an ionization current of 300 mA.
The foaming agent remaining in the bubbles and the high-boiling point aliphatic hydrocarbon, high-boiling point alicyclic hydrocarbon or mixture thereof, fluoroether, and fluoroamine can be confirmed as follows. A phenol resin foam sample is pulverized in a suitable solvent selected from pyridine, toluene, tetrahydrofuran (THF), dimethylformamide (DMF), etc. in a sealed container, and a blowing agent and a high-boiling point aliphatic hydrocarbon are obtained. High boiling alicyclic hydrocarbons or mixtures thereof, fluoroethers, fluoroamines can be extracted and subjected to gas chromatography or liquid chromatography for identification.

The ratio of the structure derived from urea crosslinking in the phenol resin foam can be calculated from the area of each component by measuring pyrolysis gas chromatography in the same manner as the ratio of phenol and trimethylphenol. The total area D of the components of the structure derived from urea crosslinking in the pyrogram and phenol, 2-methylphenol, 4-methylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, 2,4,6-trimethylphenol The total area E of D is obtained, and the area ratio of D to E is defined as F (F = D / E).
Examples of mass spectra of the decomposition products derived from urea crosslinking of the phenolic resin foam according to the present invention are shown in FIGS.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.
Resole resins used in the following examples and comparative examples were prepared as follows.
(A) Synthesis of resole resin
A reactor is charged with 5500 g of 37% formalin (manufactured by Wako Pure Chemicals, special grade of reagent) and 3000 g of 99% phenol (made by Wako Pure Chemicals, special grade of reagent) and stirred with a propeller rotating stirrer. The reactor internal liquid temperature is adjusted to 40 ° C. Next, 60 g of a 50% aqueous sodium hydroxide (NaOH) solution was added, and the reaction mixture was raised from 40 ° C. to 85 ° C. and held for 115 minutes. Thereafter, the reaction solution is cooled to 5 ° C. This is designated as resole resin A-1.
Furthermore, 2160 g of 37% formalin, 2000 g of water, and 156 g of 50% sodium hydroxide (NaOH) aqueous solution were added to the reactor, and 3200 g of urea (made by Wako Pure Chemical Industries, Ltd., reagent special grade) was added, followed by stirring with a propeller rotating stirrer. The temperature inside the reactor is adjusted to 40 ° C. using a temperature controller. Subsequently, the reaction liquid was raised from 50 ° C. to 70 ° C. and held for 60 minutes. This is methylol urea U.
Next, 1230 g of methylol urea U was mixed with the total amount of the resole resin A-1, and the liquid temperature was raised to 60 ° C. and held for 1 hour. The reaction solution was then cooled to 30 ° C. and neutralized with a 50% aqueous solution of paratoluenesulfonic acid-hydrate until the pH reached 5. The reaction solution was dehydrated at 60 ° C. and the viscosity was measured. The viscosity at 40 ° C. was 6700 cps. This is designated as resole resin A.

(B) Synthesis of resole resin
Resole resin B was synthesized in the same manner as resole resin A, except that the weight of methylolurea U to be added was changed to 300 g.
(C) Synthesis of resole resin
Resole resin C was synthesized in the same manner as resole resin A, except that the weight of methylolurea U to be added was changed to 2500 g.
(D) Synthesis of resole resin
The reactor is charged with 3800 g of 37% formalin and 3000 g of 99% phenol, stirred with a propeller rotating stirrer, and the temperature inside the reactor is adjusted to 50 ° C. with a temperature controller. Subsequently, 60 g of 50% sodium hydroxide (NaOH) aqueous solution was added, and the reaction solution was kept at 50 to 55 ° C. for 20 minutes. Thereafter, the temperature was raised to 85 ° C. and held for 125 minutes after the temperature reached 85 ° C. Thereafter, the reaction solution was cooled to 5 ° C. This is designated as resole resin D-1.
Resole resin D was synthesized in the same manner as resole resin A, except that resole resin A-1 was changed to D-1 and the weight of methylolurea U to be added was changed to 1000 g.

(E) Synthesis of resole resin
Resole resin E was synthesized in the same manner as resole resin D, except that the weight of methylolurea U to be added was changed to 500 g.
(F) Synthesis of resole resin
Resole resin F was synthesized in the same manner as resole resin D, except that the weight of methylolurea U to be added was changed to 1500 g.

(G) Synthesis of resole resin
The reactor is charged with 5200 g of 37% formalin and 3000 g of 99% phenol, stirred with a propeller rotating stirrer, and the temperature inside the reactor is adjusted to 50 ° C. with a temperature controller. Next, 60 g of 50% aqueous sodium hydroxide (NaOH) was added and the reaction was held at 40 ° C. for 10 minutes. Thereafter, the temperature was raised to 85 ° C. and held for 120 minutes after the temperature reached 85 ° C. Thereafter, the reaction solution was cooled to 20 ° C. This is designated as resole resin G-1.
The resole resin G-1 was neutralized with a 50% aqueous solution of paratoluenesulfonic acid monohydrate until the pH reached 5 and the reaction solution was dehydrated at 60 ° C. This is designated as resole resin G.

(H) Synthesis of resole resin A reactor was charged with 3040 g of 37% formalin, 3300 g of saligenin (manufactured by Tokyo Chemical Industry Co., Ltd.) and 500 g of 99% phenol, stirred with a propeller rotary stirrer, and reacted with a temperature controller. The internal liquid temperature is adjusted to 50 ° C. Subsequently, 60 g of 50% sodium hydroxide (NaOH) aqueous solution was added, and the reaction solution was kept at 50 to 55 ° C. for 20 minutes. Thereafter, the temperature was raised to 85 ° C. and held for 110 minutes after the temperature reached 85 ° C. Thereafter, the reaction solution was cooled to 5 ° C. This is designated as resole resin H-1.
The resole resin H-1 was neutralized with a 50% aqueous solution of paratoluenesulfonic acid monohydrate until the pH reached 5 and the reaction solution was dehydrated at 60 ° C. This is designated as resole resin H.

(I) Synthesis of resole resin
Resole resin I was synthesized in the same manner as resole resin D, except that the weight of methylolurea U to be added was changed to 4000 g.
(J) Synthesis of resole resin
A reactor is charged with 6300 g of 37% formalin and 3000 g of 99% phenol, stirred with a propeller rotating stirrer, and the temperature inside the reactor is adjusted to 50 ° C. with a temperature controller. Then 60 g of 50% aqueous sodium hydroxide (NaOH) was added and the reaction was held at 50-55 ° C. for 20 minutes. Thereafter, the temperature was raised to 85 ° C. and held for 180 minutes after the temperature reached 85 ° C. Thereafter, the reaction solution is cooled to 5 ° C. This is designated as resole resin J-1.
Resole resin J was synthesized in the same manner as resole resin A, except that resole resin A-1 was changed to J-1.

(K) Synthesis of resole resin
A reactor is charged with 3330 g of 37% formalin and 3000 g of 99% phenol, stirred with a propeller rotating stirrer, and the temperature inside the reactor is adjusted to 50 ° C. with a temperature controller. Next, 34 g of a 50% aqueous sodium hydroxide (NaOH) solution was added, the reaction solution was raised to 50 to 85 ° C., and held for 120 minutes after the temperature reached 85 ° C. Thereafter, the reaction solution was cooled to 5 ° C. This is designated as resole resin K-1.
Resole resin K was synthesized in the same manner as resole resin A except that resole resin A-1 in resole resin A was changed to K-1.

[Example 1]
Paintad 32 (a surfactant manufactured by Dow Corning Asia Co., Ltd.) was dissolved in resole resin A at a ratio of 3.5 g with respect to 100 g of resole resin. A pair of the resole resin mixture, normal pentane (Wako Pure Chemicals, purity 99% or more) in which 0.3% by weight of nitrogen is dissolved as a blowing agent, and isobutane (manufactured by SK Sangyo Co., Ltd., purity 99% or more) 1 mixture and a mixture of 60% by weight of paratoluenesulfonic acid monohydrate (Wako Pure Chemical, purity of 95% or more) and 40% by weight of diethylene glycol (Wako Pure Chemical, purity of 98% or more) as a curing catalyst, respectively, as a resin mixture 100 parts, a foaming agent of 7 parts, and a curing catalyst of 15 parts were supplied to a pin mixer with a temperature control jacket. It cooled with the temperature control jacket so that the temperature in a mixer might not exceed 80 degreeC. The mixture that came out of the mixer was poured into a mold laid with Spunbond E1040 (manufactured by Asahi Kasei Kogyo Co., Ltd.), placed in an oven at 80 ° C. and held for 5 hours to obtain a phenol resin foam of this example.

[Example 2]
A phenol resin was used in the same manner as in Example 1 except that a mixture of 40% by weight of paratoluenesulfonic acid monohydrate, 30% by weight of diethylene glycol and 30% by weight of resorcinol was changed to a ratio of 14 parts to 100 parts of the resin as a curing catalyst. A foam was produced.
[Example 3]
Exactly the same as in Example 1 except that a 1 to 1 mixture of normal butane and 3% by weight of PF-5050 (perfluoropentane manufactured by 3M) and 0.3% by weight of nitrogen were used as a blowing agent. Thus, a phenol resin foam was produced.

[Examples 4 to 10, Comparative Examples 1 to 3]
In Examples 4 to 10 and Comparative Examples 1 to 3, the resins shown in Table 1 were used as the resol resins, and the phenol resin foams were produced in exactly the same manner as in Example 1 while adjusting the number of catalyst parts.
[Example 11]
A phenol resin foam was produced in the same manner as in Example 1 except that normal pentane in which 0.3% by weight of nitrogen was dissolved was used as the foaming agent.
[Example 12]
A phenol resin foam was produced in the same manner as in Example 1 except that isobutane in which 0.3% by weight of nitrogen was dissolved was used as the foaming agent.

[Example 13]
A phenol resin exactly as in Example 1 except that a one-to-one mixture of normal pentane having 0.3% by weight of nitrogen dissolved therein and normal butane (manufactured by SK Sangyo Co., Ltd., purity 99% or more) was used as a blowing agent. A foam was produced.
[Example 14]
A phenolic resin foam was produced in exactly the same manner as in Example 1 except that isopentane in which 0.3% by weight of nitrogen was dissolved as a foaming agent (Wako Pure Chemical Industries, Ltd., purity 99% or more) and a one-to-one mixture of isobutane were used. did.

[Example 15]
A phenol resin foam was produced in exactly the same manner as in Example 1 except that a one-to-one mixture of isopentane and normal butane in which 0.3% by weight of nitrogen was dissolved as a foaming agent.
[Example 16]
A phenol resin foam was produced in exactly the same manner as in Example 1 except that normal hexane (Wako Pure Chemicals, first grade reagent) in which 0.3% by weight of nitrogen was dissolved as a foaming agent and a 3 to 7 mixture of isobutane were used. .
[Example 17]
Implemented except that 1-to-1 mixture of parabutene (manufactured by Wako Pure Chemical Industries, Ltd., melting point 44 ° C. to 46 ° C., primary reagent) 5% by weight, normal pentane in which 0.3% by weight of nitrogen was dissolved, and isobutane was used. A phenol resin foam was produced in exactly the same manner as in Example 1.

[Example 18]
Exactly the same as Example 1 except that 5% by weight of liquid paraffin (manufactured by Wako Pure Chemical Industries, Ltd., primary reagent), normal pentane in which 0.3% by weight of nitrogen was dissolved, and isobutane were used as a foaming agent. Thus, a phenol resin foam was produced.
[Example 19]
Exactly the same as Example 1 except that a 1-to-1 mixture of normal pentane in which 3% by weight of Galden HT-55 (manufactured by Audimond Co., Ltd.) and 0.3% by weight of nitrogen were dissolved was used as a blowing agent. Thus, a phenol resin foam was produced.

[Example 20]
Exactly the same as Example 1 except that 3% by weight of Galden HT-70 (manufactured by Audimond Co., Ltd.), normal pentane in which 0.3% by weight of nitrogen was dissolved, and isobutane were used as the blowing agent. Thus, a phenol resin foam was produced.
[Example 21]
Phenol resin in exactly the same manner as in Example 1 except that a one-to-one mixture of 3% by weight of Fluorinert FC-71 (manufactured by 3M), normal pentane having 0.3% by weight of nitrogen dissolved therein, and isobutane was used. A foam was produced.

[Example 22]
Phenol resin in exactly the same manner as in Example 1 except that a one-to-one mixture of 3% by weight of Fluorinert FC-70 (manufactured by 3M), normal pentane having 0.3% by weight of nitrogen dissolved therein, and isobutane was used. A foam was produced.
In addition, the ratio C value with respect to the area B of the phenol component of the area A of the trimethylphenol component of the pyrogram of the pyrolysis gas chromatography of the phenol resin foam sample obtained by the above Example and the comparative example, and all urea bridge | crosslinking origin Table 1 summarizes the ratio F value of the area D of the component to the area E of the total phenol derivative component and the closed cell ratio, average cell diameter, density, thermal conductivity, brittleness, and compressive strength of the foam.

As shown in Examples 1 to 22, a phenol resin foam having a C value in the range of 0.05 to 4.0, a closed cell ratio of 70% or more, and an average cell diameter in the range of 10 to 400 μm has a density of 27. Even when it is as low as ˜29 kg / m ³ , the compressive strength is 1.5 kg / cm ² or more, and the mechanical strength is excellent. In addition, brittleness is improved to less than 30%. At this time, the thermal conductivity of the example is 0.025 kcal / mhr ° C. or lower, indicating excellent heat insulation performance.
Further, in Examples except Reference Examples 1 and 2, the F value is in the range of 0.01 to 0.3, the brittleness is less than 20%, and the thermal conductivity is 0.020 kcal / mhr ° C. or less, which is more excellent. Performance.

Furthermore, as shown in Examples 17-22, when high boiling aliphatic hydrocarbons, high boiling alicyclic hydrocarbons or mixtures thereof, fluoroethers, fluoroamines are present during foaming, thermal conductivity Of 0.018 kcal / mhr ° C. or less, particularly excellent heat insulation performance.
On the other hand, in Comparative Example 2 where the C value is too large as 4.13 and Comparative Example 3 where the C value is too small as 0.04, the thermal conductivity is 0.025 kcal / mhr ° C. or more in both cases, and the brittleness is 30% or more. The value is large, and the heat insulation and mechanical strength are inferior.
In Comparative Example 1, the C value is 0.11, which is within the range of the present invention, but the closed cell ratio is 61.8%, which is outside the range of the present invention, and the thermal conductivity is 0.0273 kcal / mhr. The heat resistance is inferior at 0 ° C., the brittleness is 43% and the mechanical strength is also inferior.

  The phenol resin foam according to the present invention has excellent heat insulation performance, excellent mechanical strength such as compressive strength, and surface brittleness is remarkably improved. Since the resin foam according to the present invention uses a foaming agent having a low global warming potential without fear of destruction of the ozone layer, it is suitable as a heat insulating material for buildings that is more suitable for the global environment.

Claims (1)

It has a closed cell ratio of 80% or more, an average cell diameter of 10 μm or more and 400 μm or less, a density of 10 kg / m ³ or more and 70 kg / m ³ or less, comprising a hydrocarbon in the closed cells and a phenol resin structure having a urea cross-linking structure. A phenol resin foam having a brittleness of 20 % or less, a compressive strength of 0.5 kg / cm ² or more, and a thermal conductivity of 0.025 kcal / mhr ° C. or less.

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