JP6916066B2 - Phenol formaldehyde foam - Google Patents

Description

The present invention relates to a phenol resin foam and a method for producing the same.

Phenol resin foams are used in various fields as heat insulating materials because they are excellent in flame retardancy, heat resistance, chemical resistance, corrosion resistance and the like. For example, in the construction field, phenolic resin foams are used as synthetic resin building materials, especially as heat insulating materials for walls and floors.
The phenol resin foam is usually produced by foaming and curing a foaming phenol resin composition containing a phenol resin, a foaming agent, an acid catalyst (curing agent) and the like. The phenol resin foam produced in this manner has closed cells, and the closed cells contain gas generated from the foaming agent.

As the phenol resin foam, a phenol resin foam using a foaming agent containing a chlorinated hydrofluoroolefin or a non-chlorinated hydrofluoroolefin has been proposed (see Patent Document 1). Examples of Patent Document 1 describe an example in which a mixed gas of 1-chloro-3,3,3-trifluoropropene and cyclopentane is used as a foaming agent.
A mixture of 1-chloro-3,3,3-trifluoropropene used in the examples of Patent Document 1 and a hydrocarbon having 5 to 6 carbon atoms such as cyclopentane, or 1-chloropropane or 2-chloropropane. And a mixture with a halogenated hydrocarbon selected from 1,1,1,3,3-pentafluobtan is an azeotropic mixture-like composition (Patent Document 2).

Japanese Unexamined Patent Publication No. 2015-157937 Japanese Patent No. 5563357

Halogenated unsaturated hydrocarbons such as chlorinated hydrofluoroolefins and non-chlorinated hydrofluoroolefins have low thermal conductivity. In addition, the ozone depletion potential (ODP) and global warming potential (GWP) are small, and the impact on the environment is small. Further, since the halogenated unsaturated hydrocarbon is nonflammable, the phenol resin foam has excellent flame retardancy.
However, according to the findings of the present inventors, the phenol resin foam of Patent Document 1 has a brittle cell wall. Therefore, when this is used as a heat insulating material, defects such as chips, cracks, and dents are likely to occur due to rubbing or collision between the heat insulating materials or other members during construction of the heat insulating material. Such a defect may cause a decrease in heat insulating property such as a decrease in air density. The same tendency is observed when fluorine-containing halogenated unsaturated hydrocarbons other than chlorinated hydrofluoroolefins and non-chlorinated hydrofluoroolefins are used.

An object of the present invention is to provide a low brittle phenol resin foam using a fluorine-containing halogenated unsaturated hydrocarbon as a foaming agent and a method for producing the same.

The present invention has the following aspects.
[1] A phenol resin foam containing a phenol resin and two or more kinds of foaming agents, wherein the foaming agent contains a fluorine-containing halogenated unsaturated hydrocarbon, and the amount of fluorine (X) in the bubble wall is 5000 mg. It is / kg or less, and the content (Y) of the fluorine-containing halogenated unsaturated hydrocarbon in the bubbles is 20% by mass or more with respect to the total mass of the foaming agent in the bubbles, and (X) / (Y). The ratio of the (X) to the (Y) represented by (Y) is 50 or less, the density is 25 kg / m ³ or more and 50 kg / m ³ or less, and the closed cell ratio is 80% or more and 99% or less. A phenol formaldehyde foam having a thermal conductivity of 0.0195 W / m · K or less.
[2] A phenol resin, two or more kinds of foaming agents, and an acid catalyst are mixed to obtain a foaming phenol resin composition, and the foaming phenol resin composition is foamed and cured to produce a phenol resin foam. How to do
The foaming agent contains 20% by mass or more of fluorine-containing halogenated unsaturated hydrocarbons.
A method for producing a phenol resin foam, in which the foaming agent is mixed with the phenol resin one by one.

According to the present invention, it is possible to provide a low brittle phenol resin foam using a fluorine-containing halogenated unsaturated hydrocarbon as a foaming agent and a method for producing the same.

It is a schematic block diagram which shows the example of the manufacturing system suitable for the manufacturing method of the phenol resin foam of this invention. It is sectional drawing which shows typically the discharge device of the manufacturing system of FIG.

≪Phenol resin foam≫
A plurality of bubbles are formed in the phenol resin foam of the present invention, there are substantially no pores in the bubble wall, and at least a part of the plurality of bubbles is a closed cell that is not communicated with each other. It has become. The bubble wall is composed of a cured product of phenol resin. The compound used as a foaming agent is held in the closed cell in a gas state. The composition ratio of the gas in the closed cell is approximately the same as the composition ratio of the foaming agent.
The composition of the foaming agent in the closed cells can be confirmed by, for example, the following solvent extraction method.

Solvent extraction method:
The holding time under the following measurement conditions with a gas chromatograph-mass spectrometer (GC / MS) is determined in advance using a standard gas of a foaming agent. Next, 1.6 g of a sample of the phenol resin foam (not including the face material) is separated into a glass container for pulverization, and 80 mL of tetrahydrofuran (THF) is added. After crushing the sample to the extent that it is immersed in a solvent, the sample is pulverized and extracted with a homogenizer for 1 minute and 30 seconds, the extract is filtered through a membrane filter having a pore size of 0.45 μm, and the filtrate is subjected to GC / MS. The type of foaming agent is identified from the retention time and mass spectrum obtained in advance. In addition, other foaming agent types are identified by retention time and mass spectrum. The detection sensitivity of each of the foaming agent components is measured with a standard gas, and the composition (mass ratio) is calculated from the detection area area and the detection sensitivity of each gas component obtained by the above GC / MS.
-GC / MS measurement conditions Column used: DB-5ms (Agilent Technologies) 60m, inner diameter 0.25mm, film thickness 1μm
Column temperature: 40 ° C (10 minutes) -10 ° C / min-200 ° C
Injection port temperature: 200 ° C
Interface temperature: 230 ° C
Carrier gas: He 1.0 mL / min Split ratio: 20: 1
Measuring method: Scanning method m / Z = 11-550

The phenol resin foam is preferably formed by foaming and curing a foaming phenol resin composition containing a phenol resin, a foaming agent, and an acid catalyst.
The effervescent phenol resin composition preferably further contains an effervescent nucleating agent.
The effervescent phenolic resin composition preferably further contains a surfactant.
The effervescent phenol resin composition may further contain other components other than the phenol resin, the effervescent agent, the acid catalyst, the effervescent nucleating agent and the surfactant, if necessary, as long as the effects of the present invention are not impaired. ..

<Phenol resin>
The phenol resin is preferably a resol type.
The resole-type phenol resin is a phenol resin obtained by reacting a phenol compound and an aldehyde in the presence of an alkaline catalyst.
Examples of the phenol compound include phenol, cresol, xylenol, paraalkylphenol, paraphenylphenol, resorcinol and modified products thereof. Examples of the aldehyde include formaldehyde, paraformaldehyde, furfural, acetaldehyde and the like. Examples of the alkaline catalyst include sodium hydroxide, potassium hydroxide, calcium hydroxide, aliphatic amines (trimethylamine, triethylamine, etc.) and the like. However, the phenol compound, the aldehyde, and the alkali catalyst are not limited to the above.
The ratio of the phenol compound and the aldehyde is not particularly limited. The molar ratio of phenolic compound: aldehyde is preferably 1: 1 to 1: 3, and more preferably 1: 1.3 to 1: 2.5.

<foaming agent>
The phenolic resin foam of the present invention contains two or more kinds of foaming agents. At least one of the foaming agents is a fluorine-containing halogenated unsaturated hydrocarbon.
The foaming agent may be two or more kinds of fluorine-containing halogenated unsaturated hydrocarbons, and one or more kinds of fluorine-containing halogenated unsaturated hydrocarbons and other foaming agents other than fluorine-containing halogenated unsaturated hydrocarbons. One or more of the above may be used in combination.
The two or more types of foaming agents may have the same boiling point or different boiling points. It is preferable that at least two kinds have different boiling points.
Unless otherwise specified, the boiling point in the present specification means the boiling point at normal pressure (standard boiling point).

[Fluorine-containing halogenated unsaturated hydrocarbon]
Fluorine-containing halogenated unsaturated hydrocarbons have a carbon-carbon double bond and a halogen atom in the molecule, and have at least a fluorine atom as a halogen atom.
As the fluorine-containing halogenated unsaturated hydrocarbon, a known foaming agent can be used, and typically, those having a boiling point of −28 to 80 ° C. can be used.
The thermal conductivity of the fluorine-containing halogenated unsaturated hydrocarbon is preferably 0.013 W / m · K or less, more preferably 0.011 W / m · K or less.
The fluorine-containing halogenated unsaturated hydrocarbon preferably has 2 to 6 carbon atoms, more preferably 2 to 5 carbon atoms.

Fluorine-containing halogenated unsaturated hydrocarbons include fluorinated unsaturated hydrocarbons (however, halogen atoms other than fluorine atoms are not included), chlorinated fluorinated unsaturated hydrocarbons, brominated fluorinated unsaturated hydrocarbons, and the like. Examples thereof include iodinated fluorinated unsaturated hydrocarbons. These fluorine-containing halogenated unsaturated hydrocarbons may be used alone or in combination of two or more.
The fluorine-containing halogenated unsaturated hydrocarbon may be an unsaturated hydrocarbon in which all hydrogen atoms are substituted with halogen atoms, or an unsaturated hydrocarbon in which some of the hydrogen atoms are substituted with halogen atoms.

Examples of the fluorinated unsaturated hydrocarbon include hydrofluoroolefins (hereinafter, also referred to as “HFO”) having a carbon-carbon double bond, a fluorine atom and a hydrogen atom in the molecule. Examples of the HFO include 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,3,3,3-tetrafluoropropene (HFO-1234ze) (E and Z isomers), 1,1. , 1,4,4,4-hexafluoro-2-butene (HFO-1336mzz) (E and Z isomers) (manufactured by SynQuest Laboratories, product number: 1300-3-Z6), etc., Special Table 2009-513812 Examples are those disclosed in publications and the like.

The chlorinated fluorinated unsaturated hydrocarbon includes a hydrochlorofluoroolefin having a carbon-carbon double bond, a fluorine atom, a chlorine atom and a hydrogen atom in the molecule (hereinafter, also referred to as “HCFO”) in the molecule. Examples thereof include chlorofluoroolefins having a carbon-carbon double bond, a fluorine atom and a chlorine atom, and no hydrogen atom. HCFOs include 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) (E and Z isomers) and 1-chloro-2,3,3-trifluoropropene (HCFO-1233yd) (E). And Z isomers), 1-chloro-1,3,3-trifluoropropene (HCFO-1233zb) (E and Z isomers), 2-chloro-1,3,3-trifluoropropene (HCFO-1233xe) (E and Z isomers), 2-chloro-2,2,3-trifluoropropene (HCFO-1233xc), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), 3-chloro- 1,2,3-trifluoropropene (HCFO-1233ye) (E and Z isomers), 3-chloro-1,1,2-trifluoropropene (HCFO-1233yc), 3,3-dichloro-3-fluoro Propene, 1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd) (E and Z isomers), and 2-chloro-1,1,1,4,4,4-hexafluoro- 2-Buten (E and Z isomers) and the like can be mentioned. Examples of chlorofluoroolefins include 1,2-dichloro-1,2-difluoroethane (E and Z isomers) and 2-chloro-1,1,1,1,3,4,5,4-heptafluoro-2-. Butene (E and Z variants) and the like can be mentioned.

As the fluorine-containing halogenated unsaturated hydrocarbon, at least one selected from the group consisting of HFO and HCFO is selected because it has a small ozone depletion potential (ODP) and a small global warming potential (GWP) and has a small impact on the environment. preferable.
It is particularly preferable that the fluorine-containing halogenated unsaturated hydrocarbon contains the E isomer of 1-chloro-3,3,3-trifluoropropene ((E) -HCFO-1233zd).
When two or more kinds of fluorine-containing halogenated unsaturated hydrocarbons are used, the fluorine-containing halogenated unsaturated hydrocarbon is the E isomer of 1-chloro-3,3,3-trifluoropropene ((E) -HCFO-1233zd). And Z isomers ((Z) -HCFO-1233zd) are particularly preferred.

[Other foaming agents]
Examples of foaming agents other than fluorine-containing halogenated unsaturated hydrocarbons include hydrocarbons; halogenated saturated hydrocarbons; halogenated unsaturated hydrocarbons other than fluorine-containing halogenated unsaturated hydrocarbons; sodium hydrogencarbonate, and carbonic acid. Sodium, calcium carbonate, magnesium carbonate, azodicarboxylic acid amide, azobisisobutyronitrile, azodicarboxylic acid barium, N, N'-dinitrosopentamethylenetetramine, p, p'-oxybisbenzenesulfonylhydrazide, trihydradino Chemical foaming agents such as triazine; porous solid materials and the like can be mentioned. These foaming agents may be used alone or in combination of two or more.

As the hydrocarbon, a known foaming agent can be used, and a hydrocarbon having a boiling point of −20 ° C. or higher and 100 ° C. or lower is preferably used.
The hydrocarbon preferably has a cyclic molecular structure having 4 or more and 6 or less carbon atoms or a chain molecular structure having 4 or more and 6 or less carbon atoms. For example, isobutane, normal butane, cyclobutane, normal pentane, isopentane, cyclopentane. , Neopentane and the like.
These hydrocarbons may be used alone or in combination of two or more. These hydrocarbons can ensure excellent heat insulating properties in a wide temperature range from a low temperature range (for example, a heat insulating material for a freezer at about -80 ° C) to a high temperature range (for example, a heat insulating material for a heating body at about 200 ° C). It is relatively inexpensive and economically advantageous.

As the halogenated saturated hydrocarbon, a known foaming agent can be used, and examples thereof include chlorinated saturated hydrocarbons and fluorinated saturated hydrocarbons. The halogenated saturated hydrocarbon may be one in which all of hydrogen is substituted with halogen, or one in which part of hydrogen is substituted with halogen.
The chlorinated saturated hydrocarbon preferably has 2 or more and 5 or less carbon atoms, and examples thereof include dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride.
Examples of the fluorinated saturated hydrocarbon include difluoromethane (HFC32), 1,1,1,2,2-pentafluoroethane (HFC125), 1,1,1-trifluoroethane (HFC143a), 1,1,1. 2,2-Tetrafluoroethane (HFC134), 1,1,1,2-tetrafluoroethane (HFC134a), 1,1-difluoroethane (HFC152a), 1,1,1,2,3,3,3-hepta Fluoropropane (HFC227ea), 1,1,1,3,3-pentafluopropane (HFC245fa), 1,1,1,3,3-pentafluobtan (HFC365mfc) and 1,1,1,2,2 , 3,4,5,5,5-decafluoropentane (HFC4310mee) and other hydrofluorocarbons.
Among the above, isopropyl chloride is preferable because it has a low ozone depletion potential and is excellent in environmental compatibility.

Examples of halogenated unsaturated hydrocarbons other than fluorine-containing unsaturated hydrocarbons include chlorinated unsaturated hydrocarbons. The halogenated unsaturated hydrocarbon may be one in which all of hydrogen is substituted with halogen, or one in which part of hydrogen is substituted with halogen.

The other foaming agent preferably contains a foaming agent having no fluorine atom (hereinafter, also referred to as "non-fluorine foaming agent"). The smaller the content of the fluorine-containing halogenated unsaturated hydrocarbon in the foamable phenol resin composition, the smaller the amount of fluorine in the bubble wall of the phenol resin foam, resulting in lower brittleness. On the other hand, if the amount of the foaming agent is too small, the foamable phenol resin composition does not foam sufficiently, and the heat insulating property and moldability of the phenol resin foam deteriorate. By using a non-fluorinated foaming agent in combination, the content of the foaming agent can be sufficiently secured while reducing the content of the fluorine-containing halogenated unsaturated hydrocarbon.

As the non-fluorine foaming agent, at least one selected from the group consisting of hydrocarbons and chlorinated saturated hydrocarbons (hereinafter, also referred to as “non-fluorine foaming agent (1)”) is preferable from the viewpoint of environmental compatibility and economy. ..

The content of the fluorine-containing halogenated unsaturated hydrocarbon in the foaming agent is 20% by mass or more, more preferably 30% by mass or more, further preferably 40% by mass or more, and 50% by mass, based on the total mass of the foaming agent. % Or more is most preferable. When the content of the fluorine-containing halogenated unsaturated hydrocarbon in the foaming agent is at least the above lower limit value, the thermal conductivity of the phenol resin foam is sufficiently low.
The upper limit of the content of the fluorine-containing halogenated unsaturated hydrocarbon in the foaming agent is not particularly limited, and may be 100% by mass.
When the foaming agent contains a foaming agent other than the fluorine-containing halogenated unsaturated hydrocarbon, the content of the fluorine-containing halogenated unsaturated hydrocarbon is less than 100 mass and 85 mass with respect to the total mass of the foaming agent. % Or less is preferable.

As a preferred embodiment of the foaming agent, the fluorine-containing halogenated unsaturated hydrocarbon is 20 to 100% by mass (preferably 40 to 85% by mass) and the non-fluorine foaming agent (1) is 0 to 0 to the total mass of the foaming agent. Examples thereof include an embodiment containing 80% by mass (preferably 15 to 60% by mass).
Fluorine-containing halogenated unsaturated hydrocarbons tend to have a lower thermal conductivity than the non-fluorine foaming agent (1). When the content of the fluorine-containing halogenated unsaturated hydrocarbon is at least the lower limit of the above range, the heat insulating property of the phenol resin foam is more excellent.
On the other hand, the non-fluorinated foaming agent (1) tends to have a smaller molecular weight than the fluorine-containing halogenated unsaturated hydrocarbon. If the mass is the same, the smaller the molecular weight, the larger the volume when foamed. Therefore, the larger the proportion of the non-fluorine foaming agent (1), the easier it is to sufficiently foam with a small amount of foaming agent. Further, the non-fluorinated foaming agent (1) tends to be cheaper than the fluorine-containing halogenated unsaturated hydrocarbon. When the content of the fluorine-containing halogenated unsaturated hydrocarbon is not more than the upper limit of the above range, the cost can be reduced while maintaining excellent heat insulating properties.
In this embodiment, the fluorine-containing halogenated unsaturated hydrocarbon and the non-fluorine foaming agent (1) may be one type or two or more types, respectively.

In the combination of the fluorinated halogenated unsaturated hydrocarbon and the non-fluorinated foaming agent (1), the boiling point of the fluorinated halogenated unsaturated hydrocarbon is preferably lower than the boiling point of the non-fluorinated foaming agent (1). When the boiling point of the fluorine-containing halogenated unsaturated hydrocarbon is lower than the boiling point of the non-fluorinated foaming agent (1), the bubble diameter of the bubbles in the phenol resin foam is small and the number of bubbles per unit volume is large. , Tends to have better insulation.
Further, the difference in boiling points between them is preferably 2 ° C. or higher and 30 ° C. or lower, and more preferably 5 ° C. or higher and 20 ° C. or lower. When the difference in boiling points is larger than the above upper limit value, the fluorine-containing halogenated unsaturated hydrocarbon that has previously gasified to form bubble nuclei is released from the bubbles before the non-fluorinated foaming agent (1) having a higher boiling point is gasified. It may come off and foaming may be insufficient. If the difference in boiling points is smaller than the above lower limit, the non-fluorine foaming agent (1) foams without sufficiently forming bubble nuclei, and the bubble diameter may become coarse.
Therefore, for example, when isopropyl chloride having a boiling point of 36 ° C. is selected as the non-fluorine foaming agent (1), the fluorine-containing halogenated unsaturated hydrocarbon has a boiling point of 6 ° C. or higher and 34 ° C. or lower. Is preferable, and one having a boiling point of 14 ° C. or higher and 34 ° C. or lower is more preferable because it is easy to handle at around room temperature.

The content of the foaming agent in the foamable phenol resin composition is preferably 2 parts by mass or more and 25 parts by mass or less, more preferably 3 parts by mass or more and 15 parts by mass or less, and 5 parts by mass or more with respect to 100 parts by mass of the phenol resin. More preferably, it is 12 parts by mass or less. When it is at least the above lower limit value, the degree of foaming of the effervescent phenol resin composition is sufficient, and the heat insulating property of the phenol resin foam is likely to be enhanced. When it is not more than the above upper limit value, the degree of foaming of the effervescent phenol resin composition can be suppressed, and the compressive elastic modulus of the phenol resin foam can be easily increased.

Among the foaming agents, the content of the fluorine-containing unsaturated hydrocarbon is preferably 2 parts by mass or more and 14 parts by mass or less, and more preferably 3 parts by mass or more and 13 parts by mass or less with respect to 100 parts by mass of the phenol resin. More preferably, it is 10 parts by mass or more and 10 parts by mass or less. When the ratio of the fluorine-containing halogenated unsaturated hydrocarbon is not more than the above upper limit value, the amount of fluorine in the bubble wall of the phenol resin foam is likely to be 5000 mg / kg or less. When the ratio of the fluorine-containing halogenated unsaturated hydrocarbon is at least the above lower limit value, the heat insulating property, flame retardancy, and abrasion resistance of the phenol resin foam are excellent.

<Acid catalyst>
The acid catalyst is used to initiate the polymerization (curing) of the phenolic resin.
Examples of the acid catalyst include organic acids such as benzenesulfonic acid, ethylbenzenesulfonic acid, paratoluenesulfonic acid, xylenesulfonic acid, naphthalenesulfonic acid and phenolsulfonic acid, and inorganic acids such as sulfuric acid and phosphoric acid. These acid catalysts may be used alone or in combination of two or more.
The content of the acid catalyst in the effervescent phenol resin composition is preferably 5 to 30 parts by mass, more preferably 8 to 25 parts by mass, and even more preferably 10 to 20 parts by mass with respect to 100 parts by mass of the phenol resin.

<Effervescent nucleating agent>
By using the foam nucleating agent, the amount of fluorine in the bubble wall can be reduced. In addition, the bubbles in the phenol resin foam can be made more uniform and fine.
Examples of the effervescent nucleating agent include low boiling point substances such as nitrogen, helium, argon, carbon dioxide, and air.
The content of the foam nucleating agent in the effervescent phenol resin composition is preferably 0.05 to 5 mol%, more preferably 0.05 mol% or more and 3.0 mol% or less, based on the total number of parts of the effervescent agent. , 0.1 mol% or more and 2.5 mol% or less is more preferable, 0.1 mol% or more and 1.5 mol% or less is particularly preferable, and 0.3 mol% or more and 1.0 mol% or less is most preferable. If the content of the foam nucleating agent is less than 0.05 mol%, the effect as a bubble nucleating agent may not be sufficiently exhibited, and if it exceeds 5.0 mol%, the phenol resin foam is foam-cured. Since the foaming pressure becomes too high in the process, the bubbles of the foam may be broken, resulting in a poor foam having a low closed cell ratio and compressive strength.

<Surfactant>
The surfactant contributes to the dispersibility of the foaming agent supplied in the phenolic resin. It also contributes to the miniaturization of the bubble diameter (cell diameter).
The surfactant is not particularly limited, and known surfactants and the like can be used. For example, castor oil alkylene oxide adduct, silicone-based surfactant, polyoxyethylene sorbitan fatty acid ester and the like can be mentioned. These surfactants may be used alone or in combination of two or more.
The surfactant preferably contains one or both of the castor oil alkylene oxide adduct and the silicone-based surfactant in that it easily forms bubbles having a small bubble diameter, has a lower thermal conductivity, and is flame-retardant. It is more preferable to include a silicone-based surfactant in that the amount can be increased.

As the alkylene oxide in the castor oil alkylene oxide adduct, an alkylene oxide having 2 to 4 carbon atoms is preferable, and ethylene oxide (hereinafter, abbreviated as “EO”) and propylene oxide (hereinafter, abbreviated as “PO”) are more preferable. Preferably, EO is even more preferred. The alkylene oxide added to castor oil may be one kind or two or more kinds.
As the castor oil alkylene oxide adduct, castor oil EO adduct and castor oil PO adduct are preferable.

The number of moles of alkylene oxide added in the castor oil alkylene oxide adduct is preferably more than 20 mol and less than 60 mol, more preferably 21 to 40 mol, with respect to 1 mol of castor oil. In such a castor oil alkylene oxide adduct, a polyoxyalkylene group (polyoxyethylene group, etc.) formed by a hydrophobic group mainly composed of a long-chain hydrocarbon group of castor oil and a predetermined addition molar alkylene oxide (EO, etc.) Hydrophilic groups mainly composed of the above are arranged in a well-balanced manner in the molecule, and good surface activity is exhibited. Therefore, the bubble diameter of the phenol resin foam becomes small. In addition, flexibility is imparted to the cell wall of the phenol resin foam to prevent the occurrence of cracks.

Examples of the silicone-based surfactant include a copolymer of dimethylpolysiloxane and polyether, and an organopolysiloxane-based compound such as octamethylcyclotetrasiloxane. Of these, a copolymer of dimethylpolysiloxane and polyether is preferable in that more uniform and finer bubbles can be obtained.
The copolymer of dimethylpolysiloxane and polyether is a block copolymer of dimethylpolysiloxane and polyether. The structure of the block copolymer is not particularly limited, and is, for example, an ABA type in which a polyether chain is bonded to both ends of a siloxane chain, or a (AB) n in which a plurality of siloxane chains and a plurality of polyether chains are alternately bonded. Examples include a type, a branched type in which a polyether chain is bonded to each end of a branched siloxane chain, and a pendant type in which a polyether chain is bonded to the siloxane chain as a side group (a group bonded to a portion other than the terminal).

Examples of the copolymer of dimethylpolysiloxane and polyether include a dimethylpolysiloxane-polyoxyalkylene copolymer. The number of carbon atoms of the oxyalkylene group in the polyoxyalkylene is preferably 2 or 3. The oxyalkylene group constituting the polyoxyalkylene may be one kind or two or more kinds. Specific examples of the dimethylpolysiloxane-polyoxyalkylene copolymer include a dimethylpolysiloxane-polyoxyethylene copolymer, a dimethylpolysiloxane-polyoxypropylene copolymer, and a dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymer. Examples include polymers.
The copolymer of dimethylpolysiloxane and polyether is preferably one having a polyether chain having a terminal -OR (in the formula, R is a hydrogen atom or an alkyl group), and has a higher thermal conductivity. It is particularly preferable that R is a hydrogen atom in that it can be lowered.

The content of the surfactant in the foamable phenol resin composition is preferably 1 to 10 parts by mass, more preferably 2 to 5 parts by mass with respect to 100 parts by mass of the phenol resin. When the content of the surfactant is at least the above lower limit value, the bubble diameter tends to be uniform and fine. When the content of the surfactant is not more than the above upper limit value, the water absorption of the phenol resin foam is low, and the production cost is also suppressed.

In the effervescent phenol resin composition, the mass ratio represented by the foaming agent: surfactant is preferably, for example, 1: 1 to 6: 1. When the ratio of the foaming agent is not more than the lower limit of the above range, the foamable phenol resin composition is easily sufficiently foamed. When the ratio of the foaming agent is not more than the upper limit of the above range, the foaming agent in the foamable phenol resin composition is easily sufficiently dispersed. When the mass ratio of the foaming agent and the surfactant is within the above range, the foaming agent can be uniformly dispersed in the phenol resin to form fine bubbles.

<Other ingredients>
As other components, known additives for the effervescent phenol resin composition can be used, for example, urea, a plasticizer, a filler (filler), a flame retardant (for example, a phosphorus-based flame retardant, etc.), and the like. Examples thereof include cross-linking agents, organic solvents, amino group-containing organic compounds, and colorants.

Urea is used as a formaldehyde catcher agent that traps formaldehyde when foam-molding an effervescent phenol resin composition to produce a foam.
Examples of the plasticizer include glycol-based compounds. By using the glycol-based compound, the filler can be uniformly dispersed in the effervescent phenol resin composition. Examples of the glycol compound include polyester polyol, polyethylene glycol, alkylene glycol ether and the like. Examples of the polyester polyol include a reaction product of phthalic acid and diethylene glycol. Examples of the alkylene glycol ether include alkylene glycol alkyl ethers such as ethylene glycol methyl ether and propylene glycol methyl ether.

As the filler, an inorganic filler is preferable in that a phenol resin foam having low thermal conductivity and acidity and improved fire resistance can be obtained.
Examples of the inorganic filler include hydroxides and oxides of metals such as aluminum hydroxide, magnesium hydroxide, calcium oxide, magnesium oxide, aluminum oxide, zinc oxide, titanium oxide and antimony oxide, and metal powders such as zinc; carbonic acid. Metal carbonates such as calcium, magnesium carbonate, barium carbonate, zinc carbonate; alkali metal bicarbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate; alkaline earth metal bicarbonates such as calcium hydrogen carbonate and magnesium hydrogen carbonate; sulfuric acid Examples thereof include calcium, barium sulfate, calcium silicate, mica, talc, bentonite, zeolite, silica gel and the like. These inorganic fillers may be used alone or in combination of two or more.

The effervescent phenolic resin composition is prepared by mixing a phenolic resin, a foaming agent, an acid catalyst, and optionally optional components (foaming nucleating agent, surfactant, other components, etc.).

<Characteristics of phenol resin foam>
The amount of fluorine (X) in the cell wall of the phenolic resin foam of the present invention is represented by the mass of fluorine per 1 kg of the cell wall (unit: mg / kg), which is 5000 mg / kg or less and 4000 mg / kg or less. Is preferable, and 3000 mg / kg or less is more preferable.
The fluorine-containing halogenated unsaturated hydrocarbon used as the foaming agent is vaporized during the production of the phenol resin foam and is retained in closed cells in the gas state. However, since the fluorine-containing halogenated unsaturated hydrocarbon has high compatibility with the phenol resin, a part of the fluorine-containing halogenated unsaturated hydrocarbon may be incorporated into the bubble wall. When a fluorine-containing halogenated unsaturated hydrocarbon is incorporated into the bubble wall, the bubble wall becomes brittle.
The amount of fluorine (X) in the bubble wall is an index of the amount of fluorine-containing halogenated unsaturated hydrocarbon taken into the bubble wall. When the amount of fluorine (X) is not more than the above upper limit value, the brittleness of the phenol resin foam is sufficiently low, and defects such as corner chips, cracks, and dents due to rubbing and collision during the construction of the heat insulating material are unlikely to occur.
The lower limit of the amount of fluorine (X) in the bubble wall is not particularly limited and may be 0 mg / kg. Practically, it is set to 500 mg / kg or more.

The amount of fluorine (X) in the cell wall is measured by an analytical method based on IEC6232-1-3-2, which is a combination of a quartz tube combustion method and an ion chromatogram method. Specifically, it is measured by the following measuring method.
The central portion of the phenol resin foam includes the center of the phenol resin foam (in the case of a flat plate, the center of each of the thickness direction, the length direction, and the width direction), and is 5 mm from the surface of the phenol resin foam. It is a part that does not include the area within.

(Measuring method of the amount of fluorine (X) in the bubble wall)
(1) A sample is cut out from the central part of the phenol resin foam in a size of 5 g or more, and this sample is wrapped in a tedler bag and sealed so that the foaming agent in the bubble wall does not vaporize, and is sealed under 23 ° C. conditions. Cure for 1 hour.
(2) The sample obtained in (1) above is taken out from the tedler bag under the same 23 ° C. condition as described above, cut into an appropriate size and ground with an agate mortar to break the bubble wall, and the foaming agent in the bubble. After removing the, measure its mass. At this time, the sample mass should be at least 200 mg or more. Further, if it is finely ground, the fluorine-containing halogenated unsaturated hydrocarbon in the bubble wall may be vaporized by heating, so it is sufficient to grind it to the extent that the closed cells are destroyed.
(3) After the crushing of (2) above, the sample was cured under atmospheric pressure for 1 hour at 23 ° C. and ground in (2) above (the foaming agent in the bubbles was removed), and then the sample was burned in a quartz tube. Combustion is carried out by the method to absorb the combustion gas (solvent: sodium hydroxide solution (0.1 mol / L)).
(4) The solvent that has absorbed the combustion gas is analyzed by an ion chromatograph to quantify fluoride ions.
(5) From the mass of the sample after grinding measured in (2) above and the mass of fluoride ions quantified in (4) above, the amount of fluorine in the bubble wall is calculated by the following formula.
Amount of fluorine in the bubble wall = (quantified mass of fluoride ions (mg)) / (mass of sample after grinding (kg))

The amount of fluorine (X) in the cell wall is the content of the fluorine-containing halogenated unsaturated hydrocarbon in the foamable phenol resin composition, the content of the foam nucleating agent, and the production conditions of the phenol resin foam (foaming phenol). It can be adjusted by the preparation conditions (atmospheric pressure, etc.) and foaming conditions (heating temperature, heating time, etc.) of the resin composition.
For example, if the content of the fluorine-containing halogenated unsaturated hydrocarbon in the foamable phenol resin composition is reduced, the amount of fluorine (X) in the bubble wall is naturally reduced, but the heat insulating performance of the phenol resin foam is improved. It tends to deteriorate (heat conductivity increases). Further, by including the foaming nucleating agent in the effervescent phenol resin composition, the fluorine-containing halogenated unsaturated hydrocarbon is sufficiently vaporized, it is difficult to be taken into the bubble wall, and the amount of fluorine in the bubble wall is small. Become.
The amount of fluorine in the cell wall is usually measured from 1 week to 8 weeks after the phenol resin foam is produced.

Assuming that the content of the fluorine-containing halogenated unsaturated hydrocarbon in the bubbles is (Y) (unit: mass%) with respect to the total mass of the foaming agent in the bubbles, (Y) is the fluorine-containing in the foaming agent. It is almost the same as the content ratio of halogenated unsaturated hydrocarbons. When the foaming agent and bubbles contain two or more types of fluorine-containing halogenated unsaturated hydrocarbons, (Y) is the total content of these.
For (Y), 20% by mass or more is preferable, 30% by mass or more is more preferable, 40% by mass or more is further preferable, and 50% by mass or more is preferable for the same reason as the content of the fluorine-containing halogenated unsaturated hydrocarbon in the foaming agent. Most preferably, it is by mass or more. It may be 100% by mass.
In the present invention, the ratio of the (X) (unit: mg / kg) to the (Y) represented by "(X) / (Y)" is 50 or less, preferably 40 or less, preferably 30 or less. More preferred. The lower limit of (X) / (Y) is not particularly limited and may be 0. Practically, it is 5 or more.
When (X) / (Y) is not more than the above upper limit value, the brittleness of the phenol resin foam is sufficiently low, and defects such as corner chips, cracks, and dents due to rubbing and collision during the construction of the heat insulating material are unlikely to occur.
(Y) is obtained by measuring the composition of the foaming agent in the closed cells by the solvent extraction method and calculating the content of the fluorine-containing halogenated unsaturated hydrocarbon with respect to the total mass of the foaming agent.

The wear mass of the phenolic resin foam of the present invention is 0.6 g or less, preferably 0.5 g or less, and more preferably 0.4 g or less. When the wear mass is not more than the above upper limit value, the wear resistance of the phenol resin foam is sufficiently low, and defects such as corner chips, cracks, and dents due to rubbing and collision during the construction of the heat insulating material are unlikely to occur.
The lower limit of the wear mass is not particularly limited and may be 0 g.
The wear mass of the phenol resin foam is determined by the following measuring method.
The wear mass can be adjusted, for example, by the amount of fluorine in the cell wall. The smaller the amount of fluorine in the cell wall, the smaller the wear mass tends to be.

(Measurement method of wear mass)
A test piece having a width, a diameter of about 150 mm and a thickness of about 10 mm is cut out from the central portion of the phenol resin foam in the thickness direction. Measure the mass of the test piece before the test. Using a tabor-type ablation tester, a pair of wear wheels are pressed against a rotating test piece with a constant load to wear the test piece. Remove the shavings adhering to the test piece with a vacuum cleaner, and measure the mass of the test piece after the test. Calculate the mass difference of the test piece before and after the test and use it as the wear mass. The file used for the test is CS17, the weight of the file is 250 g, the number of rotations of the test piece is 50, and the rotation speed is 60 rpm.

The density of the phenolic foam of the present invention is less 15 kg / ^{m 3} or more 50 kg / ^{m 3,} preferably 20 kg / ^{m 3} or more 40 kg / ^{m 3} or less, more preferably 25 kg / ^{m 3} or more 35 kg / ^{m 3} or less .. When it is at least the above lower limit value, it is easy to suppress the generation of chips of the phenol resin foam, and when it is at least the above upper limit value, it is easy to improve the heat insulating property of the phenol resin foam.
Density can be measured according to JIS A 9511: 2009.
The density of the phenol resin foam can be adjusted by the type and composition of the foaming agent, the type of surfactant, the foaming conditions (heating temperature, heating time, etc.) and the like.

The closed cell ratio of the phenolic resin foam of the present invention is 80% or more, preferably 90% or more, and more preferably 95% or more. When the closed cell ratio is equal to or higher than the lower limit value, low thermal conductivity can be maintained for a long period of time.
The closed cell ratio can be measured according to JIS K 7138: 2006.

The average cell diameter in the phenolic resin foam of the present invention is preferably 50 μm or more and 200 μm or less, more preferably 50 μm or more and 120 μm or less, and further preferably 50 μm or more and 100 μm or less. When the average bubble diameter is not more than the upper limit value, convection and radiation in the bubbles are suppressed, the thermal conductivity of the phenol resin foam is low, and the heat insulating property is more excellent.
The average cell size is measured by the method described in Examples described later.
The average cell diameter of the phenol resin foam is the type and composition of the foaming agent, the ratio of phenol to formaldehyde when synthesizing the phenol resin, the amount of acid catalyst (curing rate, degree of cross-linking, elongation viscosity after cross-linking), and the interface. It can be adjusted according to the type of activator, foaming conditions (heating temperature, heating time, etc.).

The thermal conductivity of the phenolic resin foam of the present invention is preferably less than 0.0190 W / m · K, more preferably less than 0.0185 W / m · K, and even more preferably less than 0.0180 W / m · K. If the thermal conductivity is the upper limit value, the heat insulating property is excellent.
The thermal conductivity is a value at 23 ° C. and can be measured according to JIS A 1414-2.
The thermal conductivity of the phenolic resin foam can be adjusted by the type and composition of the foaming agent, the type of surfactant, the foaming conditions (heating temperature, heating time, etc.) and the like.

The shape of the phenol resin foam is not particularly limited, and may be, for example, a rectangular flat plate. The shape of the flat plate-shaped phenol resin foam (phenol resin foam plate) in a plan view is appropriately determined in consideration of the intended use, and may be, for example, a rectangular shape, a circular shape, or the like.
The size of the phenolic resin foam is also not particularly limited, and is appropriately determined in consideration of the intended use and the like.

When the phenolic resin foam of the present invention has a flat plate shape, a face material may be provided on one side or both sides thereof.
The face material is not particularly limited, and is not particularly limited. , At least one selected from calcium silicate board, gypsum board and wood-based cement board is suitable. Examples of the material of the synthetic fiber non-woven fabric include polyester, polypropylene, nylon and the like.
When the face materials are provided on both sides of the phenol resin foam, the face materials may be the same or different.

The face material may be provided when the phenol resin foam is produced, or may be provided after that.
As a method of providing the face material when producing the phenol resin foam, for example, the face material is arranged on a conveyor belt that runs continuously, the foamable phenol resin composition is discharged on the face material, and the foamable phenol resin composition is discharged on the face material. Examples thereof include a method in which other face materials are laminated and then passed through a heating furnace for foam molding. As a result, a phenol resin foam with a face material in which face materials are laminated on both sides of the flat plate-shaped phenol resin foam can be obtained. In the phenol resin foam with a face material thus obtained, the phenol resin foam and the face material are usually in direct contact with each other without using an adhesive.
As a method of providing the face material after the foam molding, for example, a method of adhering the face material to the phenol resin foam using an adhesive can be mentioned.

<Manufacturing method of phenol resin foam>
The phenol resin foam of the present invention is obtained by foaming and curing a foaming phenol resin composition containing a phenol resin, two or more kinds of foaming agents, and an acid catalyst.
In the step of preparing the effervescent phenol resin composition, a surfactant and other components are added to the phenol resin as necessary and the whole is mixed, and the effervescent agent is mixed with this mixture and then the acid catalyst is mixed. do.

Foaming of the effervescent phenol resin composition can be carried out by a known method. For example, a phenolic resin foam is produced by heating a foaming phenol resin composition in a heating furnace to foam and cure it (foaming / curing step), and then curing and drying it in a dryer (curing / drying step). The method of

1 and 2 show an example of a manufacturing system preferably used in a method for manufacturing a phenolic resin foam with a face material. FIG. 1 is a schematic configuration diagram of the manufacturing system, and FIG. 2 shows a discharge device 1 in FIG. It is sectional drawing which showed typically. This example is an example in which two kinds of foaming agents (first foaming agent and second foaming agent) are used.
The manufacturing system of this example includes a discharge device 1, a foam molding device 2 provided downstream of the discharge device 1, and a cutting device 3 provided downstream of the foam molding device 2. Reference numeral 4 in the figure indicates a phenol resin foam with a face material.

The foam molding apparatus 2 includes a frame portion 20 and heating means (not shown). The frame portion 20 includes conveyors (lower conveyor 21, upper conveyor 23) arranged vertically so that a space corresponding to the cross-sectional shape of the phenol resin foam 4 with a face material is formed. The lower conveyor 21 is a conveyor having an endless belt for running the first face member 22 in the W1 direction. The upper conveyor 23 is a conveyor having an endless belt for running the second face material 24 in the W2 direction.
Examples of the heating means include a heating furnace surrounding the frame portion 20, a heater provided in contact with the endless belt of the lower conveyor 21 or the upper conveyor 23, and the like.
Examples of the foam molding apparatus 2 include those described in JP-A-2000-218635.

The discharge device 1 discharges the effervescent phenol resin composition onto the first face material 22 and the mixing unit 14 that mixes the phenol resin, the foaming agent, and the acid catalyst to prepare the effervescent phenol resin composition. The unit 15 is provided.
The discharge unit 15 includes a plurality of nozzles (not shown), and distributes and discharges the effervescent phenol resin composition to each nozzle. The plurality of nozzles are typically arranged at equal intervals along a direction (TD direction) orthogonal to the moving direction (MD direction) of the first face member 22.
As shown in FIG. 2, the mixing unit 14 includes a continuous mixer 40, and as a means for mixing the raw materials in the mixer 40, the phenol resin supply unit 10 and the first foaming agent are supplied in this order from the upstream side. A unit 11, a second foaming agent supply unit 12, and an acid catalyst supply unit 13 are provided. Reference numeral 34 in the figure indicates an outlet. The effervescent phenol resin composition discharged from the discharge port 34 is connected to a plurality of nozzles (not shown) provided in the discharge portion 15 via a branch pipe (not shown).

The mixer 40 of this example is a pin-type mixer provided with a cylindrical container 41 having protrusions on the inner wall and a rotor 42 having protrusions. Phenol resin is supplied from the phenol resin supply unit 10 upstream in the cylindrical container 41, and the contents of the cylindrical container 41 are being stirred by the rotor 42 while moving toward the downstream discharge port 34, and the first A foaming agent, a second foaming agent, and an acid catalyst are added in sequence.
That is, the mixing unit 14 is a resin obtained by mixing a first mixing unit 31 in which a phenol resin and a first foaming agent are mixed to obtain a first mixture, and a first mixture and a second foaming agent. A second mixing unit 32 for obtaining a foaming agent mixture and a third mixing unit 33 for mixing the resin / foaming agent mixture and the acid catalyst are provided.
The effervescent phenol resin composition obtained in the third mixing section 33 is discharged from the discharge port 34 and supplied to the discharge section 15.
A jacket (not shown) for adjusting the temperature is provided on the outside of the cylindrical container 41, and the temperatures of the first mixing portion 31, the second mixing portion 32, and the third mixing portion 33 are measured, respectively. A sensor is provided for this.
Further, as a means for pressurizing the inside of the cylindrical container 41, it can be adjusted by the resin supply pressure from the phenol resin supply unit 10 and the inner diameter of the connection portion between the discharge port 34 and the distribution pipe (not shown), and the first mixing can be performed. Sensors for measuring the internal pressures of the unit 31, the second mixing unit 32, and the third mixing unit 33 are provided.

In this example, the first mixing unit 31, the second mixing unit 32, and the third mixing unit 33 are composed of a continuous mixer 40, but a batch type mixing device (for example, a hobbert type batch) is used. A mixer or the like) may be connected and configured.
Further, in this example, the first foaming agent, the second foaming agent, and the acid catalyst are sequentially added while the phenol resin is moving from the upstream to the downstream in the mixer 40, but the configuration is limited to this. Instead, in order to prevent compatibility between the first foaming agent and the second foaming agent, it is sufficient that these are separately mixed with the phenol resin one by one. For example, the connection points between the first foaming agent supply unit 11 and the second foaming agent supply unit 12 and the cylindrical container 41 are upstream of the acid catalyst supply unit 13, and the first and second foaming agents are compatible with each other. The first foaming agent supply unit 11 and the second foaming agent supply unit 12 need not be adjacent to each other but are separated from each other, and the second foaming agent supply unit 12 supplies the first foaming agent. It may be upstream from the portion 11, and may be at the same position in the height direction (direction perpendicular to the circumferential direction) of the cylindrical container 41.
Since the resin temperature in the mixer 40 increases as it approaches the discharge port 34, when the boiling point of the first foaming agent is lower than the boiling point of the second foaming agent, the first foaming agent supply unit 11 May be on the upstream side in the mixer 40. On the other hand, when the second foaming agent is a foaming agent having low compatibility with a phenol resin such as a hydrocarbon, the second foaming agent supply unit 12 may be located upstream in the mixer 40.

In the aspect of the method for producing a phenol formaldehyde foam using the production system of this example, the first face material 22 is continuously supplied between the discharge unit 15 of the discharge device 1 and the foam molding device 2.
A foaming phenol resin composition containing a phenol resin, a first foaming agent, a second foaming agent, and an acid catalyst is prepared in the mixing unit 14 of the discharge device 1, and the first foaming agent runs from the nozzle of the discharge unit 15. The foaming phenol resin composition is discharged onto the face material 22 of the above. In the foam molding apparatus 2, the second face material 24 is laminated on the foamable phenol resin composition discharged on the first face material 22 and passed through the frame portion 20 to be heated. As a result, the foamable phenol resin composition is cured between the first face material 22 and the second face material 24, and a phenol resin foam sheet is formed. The obtained phenol resin foam sheet is cut to an arbitrary length by the cutting device 3 to obtain the phenol resin foam 4 with a face material.
When the effervescent phenol resin composition is mixed with other components that do not correspond to any of the phenol resin, the acid catalyst, or the foaming agent, even if the other components are added before the phenol resin is introduced into the mixer 40. Often, other components may be added at any position within the mixer 40.

Assuming that the temperature of the first mixing section 31 is T1 and the pressure of the first mixing section 31 is P1, it is preferable that P1 is higher than the vapor pressure of the first foaming agent in T1. That is, it is preferable that the first mixing portion 31 is set to a condition in which the first foaming agent does not foam.
T1 is a value obtained by measuring the temperature of the first mixture at the most downstream position of the first mixing portion 31 with a sensor provided in the cylindrical container 41.
P1 is a value obtained by measuring the internal pressure at the most downstream position of the first mixing portion 31 with a sensor provided in the cylindrical container 41.

The temperature T2 of the second mixing unit 32 is preferably equal to or higher than the temperature (T1) of the first mixing unit 31.
Further, assuming that the pressure of the second mixing portion 32 is P2, it is preferable that P2 is higher than the vapor pressure of the first and second foaming agents in T2. That is, it is preferable that the second mixing portion 32 is under a condition in which neither the first foaming agent nor the second foaming agent foams.
T2 is a value obtained by measuring the temperature of the resin / foaming agent mixture at the most downstream position of the second mixing portion 32 with a sensor provided in the cylindrical container 41.
P2 is a value obtained by measuring the internal pressure at the most downstream position of the second mixing portion 32 with a sensor provided in the cylindrical container 41.

The temperature T3 of the third mixing unit 33 is preferably equal to or higher than the temperature (T2) of the second mixing unit 32.
Assuming that the pressure of the third mixing portion 33 is P3, when the boiling point of the first foaming agent in P3 is lower than the boiling point of the second foaming agent, P3 is higher than the vapor pressure of the first foaming agent in T3. Is low, and it is preferable that P3 is higher than the vapor pressure of the second foaming agent. That is, it is preferable that the third mixing portion 33 is under a condition in which the first foaming agent having a low boiling point foams and the second foaming agent does not foam.
T3 is a value measured by a sensor provided in the cylindrical container 41 of the temperature of the effervescent phenol resin composition at the position most downstream of the third mixing portion 33 (immediately before the discharge port 34).
P3 is a value measured by a sensor provided in the cylindrical container 41 at the position most downstream (immediately before the discharge port 34) of the third mixing portion 32.

The heating temperature in the frame portion 20 may be a temperature at which all the foaming agents are completely vaporized and the phenol resin is cured.
Assuming that the heating temperature in the frame portion 20 is Tf, T3 ≦ Tf is preferable.

When the boiling point of the first foaming agent is lower than the boiling point of the second foaming agent, the vapor pressure of the first foaming agent and the vapor pressure of the second foaming agent in T3 in the third mixing section 33. Both may be higher than P3. That is, the third mixing portion 33 may be set to a condition in which neither the first foaming agent nor the second foaming agent foams.
In this case, it is preferable that the condition immediately after the effervescent phenol resin composition discharged from the discharge port 34 is discharged from the discharge unit 15 is the condition for foaming the first foaming agent having a low boiling point. Further, the condition immediately after the discharge is preferably a condition in which the second foaming agent does not foam.
Specifically, the temperature of the effervescent phenol resin composition immediately after being discharged from the discharge unit 15 is equal to or lower than the boiling point of the first foaming agent under atmospheric pressure and from the boiling point of the second foaming agent under atmospheric pressure. It is also preferable that the temperature is higher than 5 ° C.

<Action / mechanism>
According to the method for producing a phenol resin foam of this embodiment, the brittleness of the obtained phenol resin foam is obtained even if either the first foaming agent or the second foaming agent is a fluorine-containing halogenated unsaturated hydrocarbon. It is possible to reduce defects such as chipping, cracking, and dents due to rubbing and collision. The reason why such an effect can be obtained is considered as follows.
The first foaming agent and the second foaming agent are added to the phenol resin one by one separately and mixed to prepare a foaming phenol resin composition, whereby the first foaming agent is foamed in the phenol resin. A foaming phenol resin composition in which the agent and the second foaming agent are dispersed can be obtained. When the foamable phenol resin composition is heated to foam and cure, the foaming agent having a low boiling point rapidly foams and bubble nuclei are formed before the curing proceeds, so that the bubbles of the obtained phenol resin foam are formed. Is refined and brittleness is improved.
In particular, when the combination of the first foaming agent and the second foaming agent is a combination that causes azeotrope, the first foaming agent and the second foaming agent are dispersed in the phenol resin, respectively. Azeotrope of the foaming agent and the second foaming agent can be prevented. As a result, the foaming agent having the lower boiling point can be rapidly foamed, so that the brittleness of the phenol resin foam is greatly improved.
In particular, in the combination of the first foaming agent and the second foaming agent, when the foaming agent having a lower boiling point is a fluorine-containing halogenated unsaturated hydrocarbon, the fluorine-containing halogenated unsaturated hydrocarbon rapidly foams. Therefore, dissolution of the fluorine-containing halogenated unsaturated hydrocarbon in the phenol resin is prevented. As a result, the fluorine-containing halogenated unsaturated hydrocarbon remaining in the bubble wall can be reduced.

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.
The measurement / evaluation methods used in the examples and comparative examples described later are shown below.

(density)
The density of the phenolic resin foam was measured according to JIS A 9511: 2009.

(Average cell diameter)
The average cell diameter of the phenol resin foam was determined by the following method.
The test piece was cut out from approximately the center of the phenol resin foam in the thickness direction. The cut surface in the thickness direction of the test piece was photographed at a magnification of 50 times. Four straight lines with a length of 9 cm were drawn on the captured image. At this time, a straight line was drawn so as to avoid voids (voids of 2 mm ^{2 or more).} The number of bubbles crossed by each straight line (the number of cells measured according to JIS K6400-1: 2004) was counted for each straight line, and the average value per straight line was obtained. 1800 μm was divided by the average value of the number of bubbles, and the obtained value was taken as the average bubble diameter.

(Closed cell ratio)
The closed cell ratio of the phenol resin foam was measured according to JIS K 7138: 2006.

(Thermal conductivity)
The thermal conductivity of the phenolic resin foam was measured according to JIS A 1412-2. The measurements were performed twice on the same sample.

(Abrasion mass)
A test piece having a width, a diameter of about 150 mm and a thickness of about 10 mm was cut out from the central portion of the phenol resin foam in the thickness direction, and its mass was measured. Using a tabor type ablation tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd .: No. 101 TABER TYPE ABRATION TESTER), a pair of wear wheels was pressed against a rotating test piece with a constant load to wear the test piece. The shavings adhering to the test piece were removed with a vacuum cleaner, and the mass of the test piece after the test was measured. The mass difference between the test pieces before and after the test was calculated and used as the wear mass. The file used for the test was CS17, the weight of the file was 250 g, the number of rotations of the test piece was 50, and the rotation speed was 60 rpm.

(Amount of fluorine in the bubble wall (X))
The amount of fluorine (X) in the bubble wall of the phenol resin foam was measured by the procedures (1) to (5) above.
(Content of fluorine-containing halogenated unsaturated hydrocarbon in bubbles (Y))
The composition of the foaming agent in the closed cells was measured by the solvent extraction method.

The foaming agents shown in Table 2 are as follows. Table 2 shows the boiling points (standard boiling points) of each foaming agent at 1 atm.
(E) -HCFO-1233zd: Trans-1-chloro-3,3,3-trifluoropropene (E isomer)
(Z) -HCFO-1233zd: cis-1-chloro-3,3,3-trifluoropropene (Z isomer)
CP: Cyclopentane IPC: Isopropyl chloride (2-chloropropane)

<Example 1>
A phenolic resin foam with a face material was produced using the production system shown in FIGS. 1 and 2. The discharge unit 15 includes 16 nozzles, and the nozzles are arranged at equal intervals along the TD direction of the first face material 22.
As the foaming agent, the combination of the foaming agent A shown in Table 2 was used. That is, (E) -HCFO-1233zd was used as the first foaming agent, and CP was used as the second foaming agent.

100 parts by mass of liquid resol type phenol resin (manufactured by Asahi Organic Materials Industry Co., Ltd., trade name: PF-339), 4 parts by mass of castor oil EO adduct (additional number of moles 30) as a surfactant, and urea as a formaldehyde catcher. 4 parts by mass was added and mixed, and left at 20 ° C. for 8 hours to obtain a premix.
Using the mixer 40 shown in FIG. 2, the phenol resin supply unit 10 to the premix, the first foaming agent supply unit 11 to the first foaming agent, and the second foaming agent supply unit 12 to the second foaming agent. Was introduced into the cylindrical container 41 of the mixer 40, respectively, and mixed to obtain a foaming phenol resin composition. The temperature and pressure of the first to third mixing portions 31 to 33 are shown in the table.
The blending amount of each foaming agent was adjusted so that the blending amounts of the first foaming agent and the second foaming agent with respect to 100 parts by mass of the phenol resin were the amounts shown in Table 1.
As the acid catalyst, a mixture of paratoluenesulfonic acid and xylenesulfonic acid was used, and the amount of the acid catalyst blended with respect to 100 parts by mass of the phenol resin was adjusted to 16 parts by mass.

This effervescent phenol resin composition is continuously run from the nozzle of the discharge unit 15 on the first face material 22 (material: polyester non-woven fabric, basis weight 30 g / m ² ) using a slat type double conveyor. It was discharged. A second face material 24 (material: the same as the first face material) was superposed on it, and this was heated at 70 ° C. for 300 seconds for foam molding.
After foam molding, it was dried at 80 ° C. for 5 hours to obtain a phenol resin foamed sheet.
The obtained phenol resin foam sheet was cut into a width of 910 mm and a length of 1820 mm to prepare a phenol resin foam with a face material having a thickness of 45 mm.
Regarding the obtained phenol resin foam, the density, average cell diameter, closed cell ratio, thermal conductivity, wear mass, amount of fluorine (X) in the cell wall, and fluorine-containing halogenated unsaturated carbide with respect to the foaming agent in the bubble. The hydrogen content (Y) was measured. The results are shown in Table 1 (the same applies hereinafter).

<Example 2>
In Example 2, a phenolic resin foam with a face material was produced in the same manner as in Example 1 except that the pressure and temperature in each mixing portion were changed as shown in Table 1 in Example 1. The temperature of the effervescent phenol resin composition discharged from the discharge unit 15 was 34 ° C.

<Examples 3 to 7, Comparative Example 2>
A phenolic resin foam with a face material was prepared in the same manner as in Example 1 except that the combination of the foaming agents, the blending amount, the pressure and the temperature in each mixed portion were shown in Table 1.

<Comparative example 1>
In Comparative Example 1, a foaming agent mixture in which the first foaming agent and the second foaming agent of the foaming agent A were mixed in advance was introduced from the first foaming agent supply unit 11 into the cylindrical container 41 of the mixer 40. The second foaming agent supply unit 12 was not provided.

<Comparative example 3>
In Comparative Example 3, a foaming agent mixture in which the first foaming agent and the second foaming agent of the foaming agent F were mixed in advance was introduced from the first foaming agent supply unit 11 into the cylindrical container 41 of the mixer 40. The second foaming agent supply unit 12 was not provided.

As shown in the above results, the phenolic resin foams of Examples 1 to 8 had a small wear mass and low brittleness.
In Comparative Examples 1 and 3 in which the first foaming agent and the second foaming agent were mixed and blended in advance, the amount of fluorine (X) in the bubble wall was high, the wear mass was large, and the brittleness was not sufficiently low. ..
In Comparative Example 2, in which the amount of fluorine-containing halogenated unsaturated hydrocarbon was as small as 15% by mass with respect to the total mass of the foaming agent, the wear mass was small and the brittleness was low, but the thermal conductivity was high and the heat insulating property was insufficient. there were.

1 Discharge device 2 Foam molding device 3 Cutting device 4 Phenol resin foam with face material 10 Phenol resin supply part 11 First foaming agent supply part 12 Second foaming agent supply part 13 Acid catalyst supply part 14 Mixing part 15 Discharge part 20 Frame part 21 Lower conveyor 22 First face material 23 Upper conveyor 24 Second face material 31 First mixing part 32 Second mixing part 33 Third mixing part 34 Discharge port 40 Mixer 41 Cylindrical container 42 Rotation Child

Claims (1)

A phenolic resin foam containing a phenol resin and two or more kinds of foaming agents.
The foaming agent contains a fluorine-containing halogenated unsaturated hydrocarbon and contains
The amount of fluorine (X) in the bubble wall is 5000 mg / kg or less,
The content (Y) of the fluorine-containing halogenated unsaturated hydrocarbon in the bubbles is 20% by mass or more with respect to the total mass of the foaming agent in the bubbles.
The ratio of the (X) to the (Y) represented by (X) / (Y) is 50 or less.
The density is 25 kg / m ³ or more and 50 kg / m ³ or less.
The closed cell ratio is 80% or more and 99% or less.
A phenolic resin foam having a thermal conductivity of 0.0195 W / m · K or less.

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