JP6936024B2 - Phenol formaldehyde foam - Google Patents

Description

The present invention relates to a phenolic resin foam.

Phenol formaldehyde foam is widely used as a heat insulating material in the construction and other industrial fields because it has excellent heat insulating properties, flame retardancy, and fire resistance.

By the way, it has been confirmed that the thermal conductivity of plastic heat insulating materials such as phenol resin foams changes with time from the time of manufacture. This is due to the diffusion of the gas in the bubbles to the outside of the system, and is based on the phenomenon that the foaming agent permeates the bubble film and is gradually replaced with the air in the atmosphere. Therefore, it is known that even in the phenol resin foam, the thermal conductivity increases with time and the heat insulating performance deteriorates with time.

Since the heat insulating performance of the phenol resin foam is gradually impaired by such a phenomenon, it is an important issue to ensure the long-term (time) stability of the heat insulating performance of the phenol resin foam.

On the other hand, by adding a nitrogen-containing crosslinked cyclic compound or an inorganic filler to the phenol resin composition, the long-term stability of the heat insulating performance is good, and the water absorption of the phenol resin is lower than that of the conventional product. An effervescent resol type phenol resin molding material that gives a body is known (Patent Document 1).

International Publication No. 2013/021982

However, in the technique described in Patent Document 1, it is necessary to add a nitrogen-containing crosslinked cyclic compound or an inorganic filler, which not only increases the cost due to the additive, but also increases the initial thermal conductivity and water absorption due to these additives. There is a problem of increasing. Moreover, no study has been made on the suppression of deformation.

An object of the present invention is to provide a phenol formaldehyde foam having a low water absorption, good long-term stability of thermal conductivity, and little deformation.

The present invention has the following aspects.
[1] When it is a flat plate and is divided into three in the thickness direction to form the first surface layer portion, the central layer portion, and the second surface layer portion in order from one surface.
A phenolic resin foam having a closed cell ratio of the first surface layer portion and a closed cell ratio of the second surface layer portion of 85% or more, respectively.
[2] Of the closed cell ratio of the first surface layer portion, the closed cell ratio of the central layer portion, and the closed cell ratio of the second surface layer portion, the difference between the maximum value and the minimum value is 10% or less. The phenolic resin foam according to [1].
[3] The closed cell ratio of the central layer portion is 85% or more.
The value represented by [the closed cell ratio (%) of the first surface layer portion]-[the closed cell ratio (%) of the central layer portion] is -5 to 5%.
[1] or [2], wherein the value represented by [the closed cell ratio (%) of the second surface layer portion]-[the closed cell ratio (%) of the central layer portion] is -5 to 5%. Phenol resin foam.

According to the present invention, it is possible to provide a phenol resin foam having a low water absorption, good long-term stability of thermal conductivity, and little deformation.

<Phenol resin foam>
The phenolic resin foam of the present invention has a flat plate shape.
The closed cell ratio of the surface layer portion of the phenol resin foam molded product is 85% or more.
The size of the phenolic resin foam is not particularly limited, and is appropriately determined in consideration of the intended use and the like. For example, the size of the phenol resin foam is 910 to 1000 mm in width × 1820 to 3300 mm in length × 12 to 200 mm in thickness.
The shape of the phenol resin foam may be a flat plate, and may be rectangular, circular, or the like in a plan view.
The phenol resin foam is, for example, a foam obtained by foaming and curing a foamable phenol resin composition containing a phenol resin, a foaming agent, and an acid catalyst.

The effervescent phenolic resin composition preferably further contains a surfactant.
If necessary, the effervescent phenol resin composition may further contain other components other than the phenol resin, the effervescent agent, the acid catalyst and the surfactant, as long as the effects of the present invention are not impaired.

(Phenol resin)
As the phenol resin, a resole type is preferable.
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 phenol resin may be used alone or in combination of two or more.
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 foaming agent can be selected from hydrocarbons or halogenated hydrocarbons, and these may be used in combination. In particular, since halogenated unsaturated hydrocarbons are flame-retardant, the flame-retardant properties of phenol resin foams are superior to those in which aliphatic hydrocarbons such as isopentane are used.

As the hydrocarbon, a known foaming agent can be used, and a hydrocarbon having a boiling point of -20 to 100 ° C. is preferably used.
The hydrocarbon preferably has a cyclic molecular structure having 4 to 6 carbon atoms or a chain molecular structure having 4 to 6 carbon atoms, and is, for example, isobutane, normal butane, cyclobutane, normal pentane, isopentane, cyclopentane, neopentane. And so on. These hydrocarbons may be used alone or in combination of two or more. These hydrocarbons can ensure excellent heat insulating performance 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 hydrocarbon, a known foaming agent can be used, for example, a chlorinated hydrocarbon, a chlorinated fluorinated unsaturated hydrocarbon, a fluorinated hydrocarbon, a fluorinated unsaturated hydrocarbon, or a brominated fluorinated hydrocarbon. Examples thereof include unsaturated hydrocarbons and iodide fluorinated unsaturated hydrocarbons. The halogenated 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 halogenated hydrocarbon may be a halogenated unsaturated hydrocarbon or a halogenated saturated hydrocarbon.

Examples of the chlorinated hydrocarbon include chlorinated saturated hydrocarbons, preferably those having 2 to 5 carbon atoms, such as dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, isopentyl chloride and the like. Can be mentioned.
Among the above, isopropyl chloride is preferable because it has a low ozone depletion potential and is excellent in environmental compatibility.

Examples of the chlorinated fluorinated unsaturated hydrocarbon include those containing a double bond of chlorine and fluorine in the molecule, and examples thereof include 1,2-dichloro-1,2-difluoroethane (E and Z isomers). 1-Chloro-3,3,3-trifluoropropene (HCFO-1233zd) (E and Z isomers) (manufactured by HoneyWell, trade name: SOLSTICE LBA), 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-tri Fluoropropene (HCFO-1233xe) (E and Z isomers), 2-chloro-2,2,3-trifluoropropene (HCFO-1233xc), 2-chloro-3,3,3-trifluoropropene (HCFO-) 1233xf) (SynQuest Laboratories, product number: 1300-7-09), 3-chloro-1,2,3-trifluoropropene (HCFO-1233ye) (E and Z isomers), 3-chloro-1, 1,2-Trifluoropropene (HCFO-1233yc), 3,3-dichloro-3-fluoropropene, 1,2-dichloro-3,3,3-trifluoropropene (HFO-1223xd) (E and Z isomers) ), 2-Chloro-1,1,1,4,4,4-hexafluoro-2-butene (E and Z isomers), and 2-chloro-1,1,1,3,4,4,4 -Heptafluoro-2-butene (E and Z isomers) and the like can be mentioned.

Examples of fluorinated hydrocarbons include fluorinated saturated hydrocarbons and fluorinated unsaturated hydrocarbons.
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.
Examples of the fluorinated unsaturated hydrocarbon include those containing a double bond with fluorine in the molecule, for example, 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 (HFO1336 mzz) (E and Z isomers) (SynQuest Laboratories) , Product No.: 1300-3-Z6), etc., which are disclosed in Japanese Patent Publication No. 2009-513812.

As the halogenated hydrocarbon, a halogenated unsaturated hydrocarbon is preferable because it has a small ozone destruction coefficient (ODP) and a global warming coefficient (GWP) and has a small impact on the environment, and a chlorinated fluorinated unsaturated hydrocarbon. Alternatively, fluorinated unsaturated hydrocarbons are more preferable.

The combination of two or more kinds of foaming agents is not particularly limited, but for example, a combination of one or more kinds of hydrocarbons or chlorinated hydrocarbons and one or more kinds of fluorinated unsaturated hydrocarbons, or one or more kinds of hydrocarbons or A combination of a chlorinated hydrocarbon and one or more fluorinated saturated hydrocarbons, a combination of one or more hydrocarbons or a chlorinated hydrocarbon and one or more chlorinated fluorinated unsaturated hydrocarbons, one or more A combination of chlorinated fluorinated unsaturated hydrocarbons and one or more fluorinated saturated hydrocarbons, a combination of one or more fluorinated unsaturated hydrocarbons and one or more fluorinated saturated hydrocarbons, two or more Examples thereof include a combination of chlorinated fluorinated unsaturated hydrocarbons, a combination of two or more types of fluorinated unsaturated hydrocarbons, and a combination of two or more types of fluorinated unsaturated hydrocarbons.

As a combination of two or more kinds of halogenated hydrocarbons, a combination of a chlorinated hydrocarbon and a halogenated unsaturated hydrocarbon having a double bond between a halogen atom and a carbon in the molecule is preferable. The chlorinated hydrocarbon and the halogenated unsaturated hydrocarbon may be one type or two or more types, respectively.
Chlorinated hydrocarbons have been conventionally used as a foaming agent for phenol resin foams, but when used alone, the average cell diameter of the phenol resin foams is large and the thermal conductivity is high. By using fluorinated unsaturated hydrocarbons in combination, the average cell diameter is small, the thermal conductivity is low, and the heat insulating property of the phenol resin foam is improved. Further, since the halogenated unsaturated hydrocarbon has low flammability, the flame retardancy of the phenol resin foam is improved.

In the combination of chlorinated hydrocarbons and halogenated unsaturated hydrocarbons, the mass ratio of chlorinated hydrocarbons to halogenated unsaturated hydrocarbons is chlorinated hydrocarbons: halogenated unsaturated hydrocarbons = 9.9: 0. It is preferably .1 to 0.1: 9.9. By including the halogenated unsaturated hydrocarbon within the range satisfying the above mass ratio, the average cell diameter becomes smaller, the thermal conductivity becomes lower, and the heat insulating property of the phenol resin foam becomes more excellent.
Chlorinated hydrocarbons tend to have a lower molecular weight than halogenated unsaturated hydrocarbons. If the amounts are the same, the smaller the molecular weight, the larger the volume when foamed. Therefore, the larger the proportion of chlorinated hydrocarbons, the easier it is to sufficiently foam with a small amount of foaming agent. Also, chlorinated hydrocarbons tend to be cheaper than halogenated unsaturated hydrocarbons. From these viewpoints, the mass ratio of chlorinated hydrocarbons to halogenated unsaturated hydrocarbons is preferably chlorinated hydrocarbons: halogenated unsaturated hydrocarbons = 9.9: 0.1 to 5: 5. , 9: 1 to 7: 3, more preferably. The lower the ratio of halogenated unsaturated hydrocarbons within the above range, the lower the cost while maintaining excellent heat insulating properties.
On the other hand, halogenated unsaturated hydrocarbons tend to have lower thermal conductivity than chlorinated hydrocarbons. Therefore, from the viewpoint of obtaining better heat insulating properties, the mass ratio of chlorinated hydrocarbons to halogenated unsaturated hydrocarbons is chlorinated hydrocarbons: halogenated unsaturated hydrocarbons = 5: 5 to 0.1: 9. It is preferably 9.9. The higher the ratio of halogenated unsaturated hydrocarbons within the above range, the lower the thermal conductivity and the higher the heat insulating property.

In the combination of the chlorinated hydrocarbon and the halogenated unsaturated hydrocarbon, the boiling point of the halogenated unsaturated hydrocarbon is preferably lower than the boiling point of the chlorinated hydrocarbon. When the boiling point of the halogenated unsaturated hydrocarbon is lower than the boiling point of the chlorinated hydrocarbon, the bubble diameter of the bubbles in the phenol resin foam is small, the number of bubbles per unit volume is large, and the heat insulating property is improved. Tends to be better.
Further, the difference between their boiling points is preferably 2 ° C. or higher and 30 ° C. or lower, and more preferably 5 ° C. or higher and 20 ° C. or lower. If the difference in boiling points is larger than the above upper limit, the halogenated unsaturated hydrocarbons that have previously gasified to form bubble nuclei will escape from the bubbles by the time the chlorinated hydrocarbons with higher boiling points are gasified, resulting in foaming. May be insufficient. If the difference in boiling points is smaller than the above lower limit, the chlorinated hydrocarbon may foam 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 chlorinated hydrocarbon, the halogenated unsaturated hydrocarbon having a boiling point of 6 ° C. or higher and 34 ° C. or lower is selected. It is preferable to select one having a boiling point of 14 ° C. or higher and 34 ° C. or lower because it is easy to handle near room temperature.

As the combination of the chlorinated hydrocarbon and the halogenated unsaturated hydrocarbon, a combination of isopropyl chloride and a fluorinated unsaturated hydrocarbon or a combination of isopropyl chloride and a chlorinated fluorinated unsaturated hydrocarbon is preferable. In these combinations, the fluorinated unsaturated hydrocarbon and the chlorinated fluorinated unsaturated hydrocarbon may be one type or two or more types, respectively.

The foaming agent may further contain a foaming agent other than the halogenated hydrocarbon, if necessary. Other foaming agents are not particularly limited, and are low boiling point gases such as nitrogen, argon, carbon dioxide, and air; sodium hydrogen carbonate, sodium carbonate, calcium carbonate, magnesium carbonate, azodicarboxylic acid amide, and azobisisobutyro. Chemical foaming agents such as nitrile, barium azodicarboxylate, N, N'-dinitrosopentamethylenetetramine, p, p'-oxybisbenzenesulfonylhydrazide, trihydrazinotriazine; porous solid materials and the like.

The content of the foaming agent in the effervescent phenol resin composition is preferably 1 to 25 parts by mass, more preferably 3 to 20 parts by mass, and even more preferably 5 to 15 parts by mass per 100 parts by mass of the phenol resin.

The composition (mass ratio) of the two or more kinds of foaming agents is substantially the same as the composition of the two or more kinds of foaming agents contained in the phenol resin foam.
The composition of two or more kinds of foaming agents contained in the phenol resin foam 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 phenol resin foam from which the upper and lower face materials have been peeled off is separated into a glass container for crushing, 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 the foaming agent component 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

(Acid catalyst)
Acid catalysts are used to cure phenolic resins.
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 per 100 parts by mass of the phenol resin.

(Surfactant)
Surfactants contribute to the miniaturization of 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, 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. preferable. 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.

As the castor oil alkylene oxide adduct, alkylene oxide, particularly EO of more than 20 mol and less than 60 mol, is preferably added to 1 mol of castor oil, and 21 to 40 mol is more preferable. 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 bubble wall 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. A copolymer of dimethylpolysiloxane and polyether is preferable because it is easy to adjust the surface tension by changing the degree of polymerization of each of the hydrophobic part and the hydrophilic part.
The copolymer of dimethylpolysiloxane and polyether is a block copolymer of dimethylpolysiloxane and polyether. The structure of the block copolymer is not particularly limited, for example, ABA type in which a polyether chain is bonded to both ends of a siloxane chain, and (AB) _n type in which a plurality of siloxane chains and a plurality of polyether chains are alternately bonded. , 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 as a side group (a group bonded to a portion other than the terminal) to the siloxane chain.

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 dimethylpolysiloxane-polyoxyethylene copolymer, dimethylpolysiloxane-polyoxypropylene copolymer, and dimethylpolysiloxane-polyoxyethylene-polyoxypropylene. 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 is low and can have higher flame retardancy.

When the effervescent phenol resin composition contains a surfactant, the content of the surfactant in the effervescent phenol resin composition is preferably 1 to 10 parts by mass, preferably 2 to 5 parts by mass per 100 parts by mass of the phenol resin. Is more preferable. When the content of the surfactant is not less than the lower limit of the above range, the bubble diameter tends to be uniformly reduced, and when it is not more than the upper limit, the water absorption of the phenol resin foam is low and the manufacturing cost can be suppressed. ..

(Other ingredients)
As the other component, known additives for the effervescent phenol resin composition can be used, for example, urea, a plasticizer, a filler (for example, an inorganic filler), a flame retardant (for example, a phosphorus-based flame retardant, etc.). , Crosslinking agent, organic solvent, amino group-containing organic compound, colorant and the like.

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 polyester polyol and polyethylene glycol, which are reaction products of phthalic acid and diethylene glycol.

Here, it is known that a plasticizer having high compatibility with the hydrophilic phenol resin, for example, a plasticizer containing a polyester polyol is added in order to reduce the viscosity of the phenol resin (for example, Patent No. 4761446).

As a result of the study by the inventor of the present application, it has been found that the smaller the content of the inorganic filler, the lower the thermal conductivity of the phenol resin foam tends to be. Therefore, from the viewpoint of heat insulating properties, the content of the inorganic filler in the foamable phenol resin composition is preferably less than 0.1 parts by mass and 0 parts by mass with respect to 100 parts by mass of the phenol resin. Especially preferable. That is, it is preferable that the effervescent phenol resin composition does not contain an inorganic filler.
Examples of such an 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. , Metal carbonates such as calcium carbonate, magnesium carbonate, barium carbonate, zinc carbonate, alkali metal hydrogen carbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate, alkaline earth metal hydrogen carbonates such as calcium hydrogen carbonate and magnesium hydrogen carbonate. , Calcium sulfate, barium sulfate, calcium silicate, mica, talc, bentonite, zeolite, silica gel and the like.

The effervescent phenol resin composition can be prepared by mixing each of the above components.
The mixing order of each component is not particularly limited, but for example, a surfactant and other components are added to the phenol resin to mix the whole, and a foaming agent and an acid catalyst are added to this mixture to obtain this composition. A foaming phenol resin composition can be prepared by supplying the mixture to a mixer and stirring the mixture.

A plurality of bubbles are formed in the phenolic 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 does not communicate with each other. It has become. The foaming agent gas used as the foaming agent is held in the closed cells.

As a result of the examination by the inventor of the present application, there is a distribution in the closed cell ratio in the thickness direction of the conventional phenol resin foam, and the closed cells on the surface layer side (first surface layer portion and second surface layer portion) in the foam thickness direction. By increasing the rate, it was possible to maintain the heat insulating performance for a long period of time and reduce the amount of water absorption.
Further, by eliminating the variation in the closed cell ratio in the foam thickness direction, it was possible to reduce deformation and dimensional change due to shrinkage.

When the phenol resin foam is divided into three parts in the thickness direction to form the first surface layer portion, the central layer portion, and the second surface layer portion in order from one surface, the closed cell ratio of the first surface layer portion. The closed cell ratio of the second surface layer portion is 85% or more, respectively.
The closed cell ratio of the first surface layer portion is 85% or more, preferably 90% or more, more preferably 95% or more, and may be 100%. When it is at least the above lower limit value, the foaming agent in the bubbles in the central layer portion is less likely to be replaced with air, and the heat insulating performance can be maintained for a long period of time. On the other hand, when the closed cell ratio of the first surface layer portion is less than 85%, the replacement rate of the foaming agent and air in the bubbles in the foam central layer portion increases, and the amount of change in heat insulating performance with time increases.
The closed cell ratio of the second surface layer portion is the same as that of the closed cell ratio of the first surface layer portion. The closed cell ratio of the first surface layer portion and the closed cell ratio of the second surface layer portion may be the same or different.
The closed cell ratio can be measured according to the measurement method 1 of JIS K 7138: 2006.
Here, when the thickness of the phenol resin foam is 45 mm or more, the first surface layer portion is a portion from one surface of the phenol resin foam from which the face material has been peeled off to 20 mm in the thickness direction, and the second The surface layer portion of the above is a portion up to 20 mm in the thickness direction from the other surface of the phenol resin foam from which the face material has been peeled off. The central layer portion is a portion (thickness 20 mm) of the phenol resin foam from which the face material has been peeled off, in a range of 10 mm above and below the center in the thickness direction.
When the thickness of the phenol resin foam is less than 45 mm, the phenol resin foam is divided into three equal parts in the thickness direction, and the first surface layer portion, the central layer portion, and the second surface layer are sequentially divided from one surface. It is a department.
Further, it is preferable that the closed cell ratio of at least one of the first surface layer portion and the second surface layer portion is higher than the closed cell ratio of the central layer portion, and both the first surface layer portion and the second surface layer portion are independent. It is more preferable that the bubble ratio is higher than the closed cell ratio in the central layer portion.

Further, by setting the closed cell ratio on the surface layer side to 85% or more, it becomes difficult for water to permeate from the surface layer of the phenol resin foam, and even if the phenol resin foam does not contain a neutralizing agent such as an inorganic filler, the phenol resin There is no risk of corrosion of metal members such as nails that are in contact with the foam. On the other hand, when the closed cell ratio on the surface layer side is less than 85%, moisture such as rain easily permeates from the surface layer, the acid curing agent remaining in the foam is extracted, and the metal member in contact with the foam. May be corroded.

The closed cell ratio of the central layer portion in the thickness direction of the foam is preferably 85% or more, more preferably 90% or more, still more preferably 95% or more.
When the closed cell ratio of the central layer portion is less than 85%, the bubble diameter of the central layer portion is larger than that of the surface layer side, and the amount of shrinkage of the central layer portion is larger than that of the surface layer. Shrinkage (small spoilage) occurs.

Further, it is desirable that the difference in the closed cell ratios of the first surface layer portion, the central layer portion, and the second surface layer portion is small, and the closed cell ratios of the first surface layer portion, the central layer portion, and the second surface layer portion are large. The difference between the maximum value and the minimum value is preferably 10% or less, more preferably 5% or less, and most preferably 2.5% or less.
If the difference between the maximum value and the minimum value of the closed cell ratio exceeds 10%, the difference in the amount of shrinkage between the portion where the closed cell ratio is high and the portion where the closed cell ratio is low becomes large, and the foam may warp.
Further, the difference between the closed cell ratio of the first surface layer and the closed cell ratio of the central layer is [the closed cell ratio of the first surface layer (%)]-[the closed cell ratio of the central layer (%). )], It is preferably −5 to 5%, more preferably −2.5 to 2.5%.
The difference between the closed cell ratio of the second surface layer and the closed cell ratio of the central layer is [the closed cell ratio of the first surface layer (%)]-[the closed cell ratio of the central layer (%)]. In representation of, −5 to 5% is preferable, and −2.5 to 2.5% is more preferable.
If the difference between the closed cell ratios on the central layer side and the surface layer side is out of the above numerical range, the difference in the closed cell ratio causes a difference in the amount of shrinkage between the surface layer side and the central layer portion, and the central layer portion of the foam cross section. Shrinkage (small spoilage) occurs.

Further, both the closed cell ratio of the central layer portion and the closed cell ratio of the surface layer side are preferably 85% or more, more preferably 90% or more, still more preferably 95% or more. If both the closed cell ratio of the central layer and the closed cell ratio of the surface layer are less than 85%, the replacement rate of the foaming agent in the bubbles with air increases, and the amount of change in thermal conductivity with time only increases. In addition, the mechanical strength that can withstand the shrinkage stress in a high temperature environment is impaired, and the dimensional change rate is significantly deteriorated.

The average closed cell ratio calculated from the closed cell ratios of the first surface layer portion, the central layer portion, and the second surface layer portion is preferably 85% or more, and preferably 90% or more.
When the average closed cell ratio is within the above numerical range, low thermal conductivity can be maintained for a long period of time, deformation such as warpage and edge spoilage can be prevented, and dimensional stability can be improved.

Water absorption of phenolic foam is preferably from 3.0 g / 100 cm ² or less, more preferably ^{2.5g / 100cm 2, 2.0g / 100cm} 2 or less is most preferred. By keeping the water absorption within the above range, low thermal conductivity is maintained for a long period of time, and even when the phenol resin foam gets wet, acidic water is difficult to be extracted and is in contact with the phenol resin foam. It is possible to suppress rusting of metal and temporary decrease in strength due to wetting. The amount of water absorption varies depending on the type and amount of the surfactant and acid curing agent used, and the closed cell ratio, but it can be made difficult to absorb water by improving the closed cell ratio of the surface layer in contact with water.
The amount of water absorption can be measured according to JIS A 9511.

(Extraction pH)
The extraction pH of the phenolic resin foam of the present invention is less than 2.5 to 6, preferably less than 3 to 5. When it is within the above range, the foam curing reaction at the time of forming the foam becomes good. If it is less than the lower limit of the above range, rust or corrosion may occur in the material that comes into contact with the phenol resin foam. If it exceeds the upper limit of the above range, the foam curing reaction at the time of foam formation may be hindered. Further, in order to adjust to exceed the upper limit of the above range, it is necessary to add an excessive amount of a neutralizing agent such as calcium carbonate, which may deteriorate the thermal conductivity.

The extraction pH is measured by the following method. The phenolic resin foam is pulverized in a mortar to 250 μm (60 mesh) or less to prepare a sample. Weigh 0.5 g of the sample into a 200 mL Erlenmeyer flask with a stopper. Add 100 mL of pure water to an Erlenmeyer flask with a stopper and seal it tightly. Using a magnetic stirrer, the inside of the Erlenmeyer flask with a stopper is stirred at 23 ° C. ± 5 ° C. for 7 days to prepare a sample solution. The pH of the obtained sample solution is measured with a pH meter, and the value is taken as the extraction pH.

The average cell diameter in the phenolic resin foam of the present invention is preferably 5 to 130 μm, more preferably 30 to 120 μm, further preferably 50 to 110 μm, and most preferably 60 to 100 μm. When the average bubble diameter is 5 to 130 μm, convection and radiation in the bubbles are suppressed, the thermal conductivity of the phenol resin foam is low, and the heat insulating property is excellent.

(Average cell diameter)
A test piece is 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 is photographed at a magnification of 50 times. Draw four straight lines with a length of 9 cm on the captured image. At this time, draw a straight line 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) is counted for each straight line, and the average value per straight line is obtained. Divide 1800 μm by the average value of the number of bubbles, and use the obtained value as the average bubble diameter.

The average cell diameter 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. In particular, the average cell diameter can be reduced by using a composition in which two or more kinds of foaming agents are used in combination, and hydrocarbons / chlorinated hydrocarbons and fluorinated unsaturated hydrocarbons / chlorinated fluorinated unsaturateds are used as foaming agents. When the mass ratio with hydrocarbon is within the range of 9.9: 0.1 to 0.1: 9.9, the average cell diameter tends to be smaller than that outside the range.

The mass ratio of hydrocarbons to fluorinated unsaturated hydrocarbons or chlorinated fluorinated unsaturated hydrocarbons is: hydrocarbons: fluorinated unsaturated hydrocarbons or chlorinated fluorinated unsaturated hydrocarbons = 9: 1 to 1: 9. Is preferable, 8: 2 to 2: 8 is more preferable, and 5: 5 to 3: 7 is even more preferable. When the ratio of the fluorinated unsaturated hydrocarbon or the chlorinated fluorinated unsaturated hydrocarbon is at least the above lower limit value, the heat insulating property of the phenol resin foam can be further enhanced. When the ratio of the fluorinated unsaturated hydrocarbon or the chlorinated fluorinated unsaturated hydrocarbon is not more than the above upper limit value, the effervescent phenol resin composition can be sufficiently foamed. Fluorinated unsaturated hydrocarbons or chlorinated fluorinated unsaturated hydrocarbons have high compatibility with phenolic resins. Therefore, when the ratio of the fluorinated unsaturated hydrocarbon or the chlorinated fluorinated unsaturated hydrocarbon exceeds the above upper limit value, the viscosity of the phenol resin composition is lowered, and the foaming of the phenol resin tends to be insufficient.

The thermal conductivity of the phenolic resin foam of the present invention is 0.0200 W / m · K or less, more preferably 0.0190 W / m · K or less, and most preferably 0.0185 W / m · K or less. If the thermal conductivity is 0.019 W / m · K or less, the heat insulating property is excellent.
Thermal conductivity can be measured according to JIS A 1412-2.

The thermal conductivity of the phenolic resin foam can be adjusted by adjusting the average cell size, the type and composition of the foaming agent, the type of surfactant, and the like. For example, as described above, the smaller the average cell diameter, the lower the thermal conductivity of the phenol resin foam tends to be. Further, when the surfactant is a silicone-based surfactant, particularly one having a polyether chain having a −OH terminal, the thermal conductivity tends to be lower than when other surfactants are used.

The phenolic resin foam of the present invention has a Limited Oxygen Index (hereinafter, also referred to as “LOI”) of 28% or more, preferably 30% or more.
LOI is the minimum oxygen concentration% (volume fraction) of a mixed gas of oxygen and nitrogen at 23 ° C. ± 2 ° C. required for the sample to maintain flame combustion under specified conditions, and is combustible. It is an index. The larger the LOI, the lower the flammability. Generally, if the LOI is 26% or more, it is judged to have flame retardancy.
LOI can be measured according to JIS K 7201-2: 2007.

The LOI of the phenol resin foam can be adjusted by the type and composition of the foaming agent, the type of the surfactant, the type and composition of the flame retardant and the amount thereof. For example, the lower the content of the flammable foaming agent in the foaming agent (the higher the content of halogenated hydrocarbons), the higher the LOI. Further, if the surfactant is a silicone-based surfactant, particularly one having a polyether chain having a −OH terminal, the LOI tends to be higher than when other surfactants are used. Further, the LOI can be increased by adding a phosphorus-based flame retardant or the like.

The density of the phenolic resin foam of the present invention ^{is preferably 10 kg / m 3} or more and 100 kg / m ³ or less, and more preferably 20 kg / m ³ or more and 35 kg / m ³ or less. Preferably the density is in the first surface portion is 25~38kg / ^{m 3,} it is preferred second surface portion even density of 25~38kg / ^{m 3.} The density of the central layer is preferably ^{22 to 30 kg / m 3.} When the density is within the above numerical range, it is possible to prevent deformation such as warpage and edge spoilage, and improve dimensional stability. Density can be measured according to JIS A 9511: 2009.

The brittleness of the phenolic resin foam of the present invention is preferably 20% or less, more preferably 10 to 18%.
Brittleness can be measured according to JIS A 9511: 2003.

A face material may be provided on the surface of the phenol resin foam.
The face material is not particularly limited, and is woven fabric, glass fiber non-woven fabric, papers such as glass fiber mixed paper and kraft paper, polyester fiber non-woven fabric, polypropylene fiber non-woven fabric, synthetic fiber non-woven fabric such as nylon fiber non-woven fabric, and aluminum foil-covered non-woven fabric. , Metal plate, metal foil, plywood, calcium silicate plate, gypsum board and at least one selected from wood-based cement board are suitable.
The face material may be provided on one side of the phenol resin foam, or may be provided on both sides. When provided on both sides, each face material may be the same or different.
As a method of providing a face material when producing a phenol resin foam, the face material is arranged on a conveyor belt that runs continuously, which will be described later, and a 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 sheet-shaped phenol resin foam can be obtained.
The face material may be provided by sticking it to a phenol resin foam using an adhesive after foam molding.

The thickness of the face material is not particularly limited, but in the case of a synthetic fiber non-woven fabric such as a polyester fiber non-woven fabric, it is preferably 0.1 mm or more and 0.25 mm or less. In the case of papers such as glass fiber mixed paper, 0.1 mm or more and 1.0 mm or less are preferable. In the case of a glass fiber non-woven fabric, it is preferably 0.1 mm or more and 1.0 mm or less.

Basis weight of the surface material is not particularly limited, when using a synthetic fiber nonwoven fabric, the basis weight that is preferably, 15 g / ^{m 2} or more 150 g / ^{m 2} or less is 15 g / ^{m 2} or more 200 g / ^{m 2} or less it is more preferable, further preferably 15 g / ^{m 2} or more 100 g / ^{m 2} or less, particularly preferably at 15 g / ^{m 2} or more 80 g / ^{m 2} or less, 15 g / ^{m 2} or more 60 g / ^{m 2} or less Most preferably.
When glass fiber mixed paper is used, the grain ^{size is preferably 30 g / m 2} or more and 300 g / m ² or less, more preferably 50 g / m ² or more and 250 g / m ² or less, and 60 g / m ² or more. It is more preferably 200 g / m ² or less, and particularly preferably 70 g / m ² or more and 150 g / m ² or less.
When a glass fiber non-woven fabric is used, the texture is preferably 15 g / m ² or more and 300 g / m ² or less, more preferably 20 g / m ² or more and 200 g / m ² or less, and 30 g / m ² or more and 150 g. It is more preferably / m ^{2 or less.}
When the basis weight is not more than the above lower limit value, the effervescent phenol resin composition does not easily exude to the surface of the face material. When the basis weight is not more than the above upper limit value, the adhesiveness between the foam and the face material can be enhanced. As a result, the face material is less likely to peel off from the foam, and the surface can be made more beautiful. In addition, in the manufacturing method described later, it becomes easy to follow the transport equipment such as a conveyor, and it is easy to increase the productivity of the phenol resin foam.

By using a face material with low air permeability such as a metal plate or metal foil, it is possible to prevent the thermal conductivity from deteriorating due to the replacement of the foaming agent gas and air on the surface layer of the foam. In the present invention, by improving the closed cell ratio of the surface layer, it is possible to suppress the deterioration of the thermal conductivity even in a highly breathable surface material such as a synthetic fiber non-woven fabric or paper. Further, by using a face material containing titanium oxide, the thermal conductivity of the face material can be improved, the temperature unevenness on the surface can be eliminated, and the closed cells on the surface layer can be improved.

<Manufacturing method of phenol resin foam>
The phenolic resin foam of the present invention can be produced by foaming and curing the above-mentioned foamable phenolic resin composition.
The phenolic resin foam of the present invention can be produced by using a known foam molding method. An example is given below.

In this example, a manufacturing system including a discharge device, a foam molding device arranged on the downstream side of the discharge device, and a cutting device arranged on the downstream side of the foam molding device is used.
The discharge device includes a mixing unit for mixing raw materials such as phenol resin, and a plurality of nozzles arranged along a direction orthogonal to the flow direction for discharging the mixed raw materials (foamable phenol resin composition). To be equipped with.
The foam molding apparatus includes a frame portion and heating means. The frame portion includes conveyors (lower conveyor, upper conveyor, left conveyor, right conveyor) arranged vertically and horizontally so as to form a space corresponding to the cross-sectional shape of the phenol resin foam. The lower conveyor and the upper conveyor regulate the foaming in the vertical direction, and the left conveyor and the right conveyor regulate the foaming in the horizontal direction. The effervescent phenol resin composition that passes through the frame portion can be heated, foamed, and cured by the heating means. Examples of such a foam molding apparatus include those described in JP-A-2000-218635.

In this manufacturing system, first, the first face material is continuously supplied between the discharge device and the foam molding device. A foaming phenol resin composition is prepared by mixing a phenol resin or the like with a discharge device, and is discharged from a plurality of nozzles onto the first face material. A second face material is laminated on it, introduced into the frame portion of the foam molding apparatus, and heated at 30 to 95 ° C. As a result, the foamable phenol resin composition is foamed and cured between the first face material and the second face material to form a phenol resin foamed sheet. This phenol resin foam sheet is taken out from the foam molding apparatus and cut to an arbitrary length by the cutting apparatus. As a result, a phenol resin foam in which the first face material is laminated on one surface and the second face material is laminated on the other surface can be obtained.

In such a production method, the foamable phenol resin composition discharged onto the first face material foams to some extent before being introduced into the foam molding apparatus, but at this time, as much as possible in the width direction (foaming) of the phenol resin foam. It is preferable that the composition is spread in a direction (TD direction) orthogonal to the discharge direction of the phenol resin composition. By spreading the effervescent phenol resin composition in the TD direction, the amount of the resin composition moving in the TD direction in the foam molding apparatus is reduced, and the bubbles that are being cured by heating collapse due to the movement of the resin composition. It is possible to suppress a decrease in the closed cell ratio. In particular, since the surface layer side of the resin composition is expanded by the upper and lower conveyors, it is possible to improve the closed cell ratio of the first surface layer portion and the second surface layer portion by expanding the resin composition in the TD direction. I found that I could do it.

As a method of spreading the effervescent phenol resin composition in the TD direction, a method of arranging a branch pipe having a plurality of branch portions (for example, WO2014 / 133023) in the TD direction and discharging the foamable phenol resin composition onto a conveyor is known. , It was not possible to discharge evenly with the split pipe with many branch parts, and there was a difference in the discharge amount for each discharge port, so it was necessary to use a special split pipe. Further, the resin composition having a high viscosity is easily clogged at the branch portion, and the resin composition having a high viscosity cannot be used. As another method, a method in which the slit die has a long ejection portion in the TD direction is also known (WO2009 / 066621), but the resin does not flow in the die at a uniform speed, and after ejection at a slow flow portion and a fast flow portion. The properties (viscosity, etc.) of the resin are changing, and it becomes difficult to discharge a uniform amount from a plurality of discharge ports. If the discharge amount is not uniform in this way, the resin composition moves in the TD direction in the foam molding apparatus, and the closed cell ratio on the surface layer side decreases.
Further, it is known that volatile components such as water contained in the resin composition evaporate after foaming and hardening to form holes in the cell wall and reduce the closed cell ratio (for example, Patent No. 3813062). , It is desirable to reduce the amount of water in the resin composition, but if the volatile components such as water are reduced, the viscosity will increase. , It was difficult to stably discharge the high-viscosity resin composition.
In the present invention, by using a doctor blade that spreads the resin after discharge, it is possible to improve the closed cell ratio of the surface layer by spreading the resin composition in the TD direction. Further, since the width can be widened in the TD direction even if a split pipe having a small number of branch portions and a large discharge port is used, it has become possible to improve the closed cell ratio of the entire foam by using a resin composition having a high viscosity.

Specifically, for example, when the length in the TD direction is 1000 mm, a plurality of doctor blades having eight or less discharge ports in the TD direction and having a V-shaped cross section are arranged after each discharge port. That is, the same number of doctor blades as the discharge ports are arranged. By this doctor blade, the tip of each doctor blade (center part of V shape) is inserted into the resin composition discharged from each discharge port, and the resin composition is pushed to the end portion (left and right end of V shape) of the doctor blade. Can be unfolded.
Since the temperature near the center of the resin composition discharged by the V-shaped doctor blade is lowered, the closed cell ratio on the central layer side can be improved. The shape of the doctor blade is not limited to the V shape, and may be a U shape.
As the material of the doctor blade, a metal plate such as iron or stainless steel processed into a V shape can be used, but the material or the surface is acid-resistant coated so as not to rust due to the acidic phenol resin composition. It is preferable to apply.
It is preferable that the plurality of doctor blades are arranged apart from each other, which makes it difficult for the resin composition to stay. When the conventionally known doctor blades have a continuous plate shape in the TD direction (for example, Japanese Patent Application Laid-Open No. 8-216175), the amount of the resin composition retained by the doctor blades increases in a highly viscous resin composition. , The time from the discharge port to the introduction of the resin composition into the foam molding apparatus becomes non-uniform, and foaming defects tend to occur.
By using the doctor blade as described above, the resin composition can be spread in the TD direction even when the high-viscosity resin composition having a reduced water content is discharged from the discharge portion having a large diameter and few branch portions. It is possible to increase the closed cell ratio of the surface layer. Further, since it is not necessary to raise the temperature in order to lower the viscosity, the closed cell ratio of the central layer can be increased by suppressing the temperature rise inside the resin composition in which the temperature tends to rise.

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 foaming agents used in Examples and Comparative Examples are as follows. However, Examples 1 to 7 are reference examples.

-Effervescent agent (1): Isopropyl chloride: Isopentane = 85: 15 mixture (mass ratio)
-Effervescent agent (2): Isopropyl chloride: Trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) = 70:30 (mass ratio) mixture-Effervescent agent (3): Isopentane: Isopentane = 50: 50 (mass ratio) mixture / foaming agent (4): isopentane / foaming agent (5): normalpentane / foaming agent (6): cyclopentane: trans-1-chloro-3,3,3-tri Fluoropropene (HCFO-1233zd) = 20:80 (mass ratio) mixture / foaming agent (7): Cyclopentane: Trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) = 50: 50 (mass ratio) mixture / foaming agent (8): Cyclopentane: trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) = 80:20 (mass ratio) mixture / foaming agent (9): Isopentane: Trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) = 20:80 (mass ratio) mixture / foaming agent (10): Isopentane: Trans-1-chloro -3,3,3-trifluoropropene (HCFO-1233zd) = 50:50 (mass ratio) mixture / foaming agent (11): Isopentane: Trans-1-chloro-3,3,3-trifluoropropene ( HCFO-1233zd) = 80:20 (mass ratio) mixture

(Manufacturing of phenol resin foam)
<Example 1>
Liquid resol type phenol resin (manufactured by Asahi Organic Materials Industry Co., Ltd., trade name: PF-339) 100 parts by mass, 4 parts by mass of castor oil EO adduct (additional number of moles 30) as a surfactant, urea 4 as a formaldehyde catcher Parts by mass were added, mixed, and left at 20 ° C. for 8 hours.
To 108 parts by mass of the mixture thus obtained, 10.5 parts by mass of the foaming agent (1) was added as a foaming agent, and 16 parts by mass of a mixture of paratoluenesulfonic acid and xylenesulfonic acid was added as an acid catalyst. , Stirring and mixing to prepare an effervescent phenolic resin composition.
This effervescent phenol resin composition is ejected from six nozzles arranged in the TD direction onto a first face material (material: glass fiber mixed paper, basis weight: 70 g / m ² ) that is continuously running. rice field. At this time, six V-shaped doctor blades (width 120 mm, V-shaped angle 120 °) were installed immediately after the discharge port of the nozzle, and the phenol resin composition was widened in the TD direction. At this time, the doctor blades were installed at a distance of 56 mm.
A second face material (material: glass fiber mixed paper) was overlaid on it, and this was heated at 70 ° C. for 300 seconds for foam molding. The obtained phenol resin foam was cut into a width of 910 mm and a length of 1820 mm to prepare a phenol resin foam plate having a thickness of 45 mm.

<Example 2>
A test piece of a phenol resin foam was obtained in the same manner as in Example 1 except that the phenol resin foam plate was molded into a width of 910 mm, a length of 1820 mm, and a thickness of 90 mm, and the phenol resin foam plate was cut into a width of 30 mm, a length of 30 mm, and a thickness of 90 mm. rice field.

<Example 3>
A test piece of a phenol resin foam was obtained in the same manner as in Example 1 except that the foaming agent was changed from the foaming agent (1) to the foaming agent (2).

<Example 4>
The foaming agent was changed from the foaming agent (1) to the foaming agent (3), and a polyester non-woven fabric containing titanium oxide described in Example 4 of JP2010-21604A as upper and lower face materials (with a grain of 35 g / m). A test piece of a phenol resin foam was obtained in the same manner as in Example 1 except that ^2).

<Example 5>
A test piece of a phenol resin foam was obtained in the same manner as in Example 1 except that the foaming agent was changed from the foaming agent (1) to the foaming agent (4).

<Example 6>
A test piece of a phenol resin foam was obtained in the same manner as in Example 1 except that the foaming agent was changed from the foaming agent (1) to the foaming agent (5).

<Example 7>
Phenol resin foaming is the same as in Example 1 except that the number of nozzles is eight, the number of doctor blades (width 90 mm, V-shaped angle 120 °) is eight, and the doctor blades are separated by 40 mm. A test piece of the body was obtained.

<Example 8>
Except for changing the foaming agent from the foaming agent (1) to the foaming agent (6), molding it into a width of 910 mm × length 1820 mm × thickness 60 mm, and cutting out a phenol resin foam plate into a width 30 mm × length 30 mm × thickness 60 mm. Obtained a test piece of a phenol resin foam in the same manner as in Example 4.

<Example 9>
Except for changing the foaming agent from the foaming agent (1) to the foaming agent (7), molding it into a width of 910 mm × length 1820 mm × thickness 60 mm, and cutting out a phenol resin foam plate into a width 30 mm × length 30 mm × thickness 60 mm. Obtained a test piece of a phenol resin foam in the same manner as in Example 4.

<Example 10>
Except for changing the foaming agent from the foaming agent (1) to the foaming agent (8), molding it into a width of 910 mm × length 1820 mm × thickness 60 mm, and cutting out a phenol resin foam plate into a width 30 mm × length 30 mm × thickness 60 mm. Obtained a test piece of a phenol resin foam in the same manner as in Example 4.

<Example 11>
The foaming agent was changed from the foaming agent (1) to the foaming agent (9), a polyester non-woven fabric (with a grain of 20 g / m ² ) was used as the upper and lower face materials, and the width was 910 mm, the length was 1820 mm, and the thickness was 100 mm. A test piece of a phenol resin foam was obtained in the same manner as in Example 1 except that the foam plate was cut into a width of 30 mm, a length of 30 mm, and a thickness of 100 mm.

<Example 12>
The foaming agent was changed from the foaming agent (1) to the foaming agent (10), a polyester non-woven fabric (with a grain of 20 g / m ² ) was used as the upper and lower face materials, and the width was 910 mm, the length was 1820 mm, and the thickness was 100 mm. A test piece of a phenol resin foam was obtained in the same manner as in Example 1 except that the foam plate was cut into a width of 30 mm, a length of 30 mm, and a thickness of 100 mm.

<Example 13>
The foaming agent was changed from the foaming agent (1) to the foaming agent (11), a polyester non-woven fabric (with a grain of 20 g / m ² ) was used as the upper and lower face materials, and the width was 910 mm, the length was 1820 mm, and the thickness was 100 mm. A test piece of a phenol resin foam was obtained in the same manner as in Example 1 except that the foam plate was cut into a width of 30 mm, a length of 30 mm, and a thickness of 100 mm.

<Comparative example 1>
A test piece of phenol resin foam was prepared in the same manner as in Example 1 except that 16 nozzles arranged in the TD direction described in Example 1 of WO2014 / 13302 were used and no doctor blade was used. Obtained.

<Comparative example 2>
A test piece of a phenol resin foam was obtained in the same manner as in Example 1 except that the slit die described in Example 1 of WO2009 / 066621 was used and no doctor blade was used.

The thermal conductivity, closed cell ratio, density, and water absorption of the phenolic resin foam plate or test piece obtained in each example were measured, and the average closed cell ratio was calculated. Furthermore, the long-term performance of thermal conductivity and the presence or absence of deformation were evaluated. When the extraction pH of the obtained phenol resin foam was measured, all of them were less than pH 6 and acidic.

(Measurement of closed cell ratio)
Examples 1 and 3 to 6, Comparative Examples 1 and 2: Three test pieces were cut out from the central portion of the phenolic resin foam plate to a width of 30 mm, a length of 30 mm, and a thickness of 45 mm with a cutter knife. First, the first test piece was cut out with a cutter knife from one surface (upper surface side) from which the face material was peeled off to a portion of 20 mm in the thickness direction, and this was used as the test piece for the first surface layer portion.
Next, the second test piece was cut out with a cutter knife from the other surface (lower surface side) from which the face material was peeled off to a position of 20 mm in the thickness direction, and this was used as a test piece for the second surface layer portion.
Further, regarding the third test piece, a portion of the test piece cut out to a width of 30 mm, a length of 30 mm, and a thickness of 45 mm from one surface to 12.5 to 32.5 mm is cut out with a cutter knife to form a central layer portion. It was used as a test piece.
Example 2: Three test pieces cut out from the central portion of the phenolic resin foam plate to a width of 30 mm, a length of 30 mm, and a thickness of 90 mm with a cutter knife were prepared.
First, with respect to the first test piece, a part from one surface (upper surface side) from which the face material was peeled off to a portion of 20 mm in the thickness direction was cut out with a cutter knife to obtain a test piece for the first surface layer portion.
Next, with respect to the second test piece, a part from the other surface (lower surface side) from which the face material was peeled to 20 mm in the thickness direction was cut out with a cutter knife to obtain a test piece for the second surface layer portion.
Further, regarding the third test piece, a test piece cut out to a width of 30 mm, a length of 30 mm, and a thickness of 90 mm was cut from one surface to a portion of 35 to 55 mm with a cutter knife to obtain a test piece in the central layer portion. ..
Examples 8 to 10: Three test pieces cut out from the central portion of the phenolic resin foam plate to a width of 30 mm, a length of 30 mm, and a thickness of 60 mm with a cutter knife were prepared.
First, with respect to the first test piece, a part from one surface (upper surface side) from which the face material was peeled off to a portion of 20 mm in the thickness direction was cut out with a cutter knife to obtain a test piece for the first surface layer portion.
Next, with respect to the second test piece, a part from the other surface (lower surface side) from which the face material was peeled to 20 mm in the thickness direction was cut out with a cutter knife to obtain a test piece for the second surface layer portion.
Further, regarding the third test piece, a test piece cut out to a width of 30 mm, a length of 30 mm, and a thickness of 60 mm, and a portion of 20 to 40 mm from one surface was cut out with a cutter knife to obtain a test piece in the central layer portion. ..
Examples 11 to 13: Three test pieces cut out from the central portion of the phenolic resin foam plate to a width of 30 mm, a length of 30 mm, and a thickness of 100 mm with a cutter knife were prepared.
First, with respect to the first test piece, a part from one surface (upper surface side) from which the face material was peeled off to a portion of 20 mm in the thickness direction was cut out with a cutter knife to obtain a test piece for the first surface layer portion.
Next, with respect to the second test piece, a part from the other surface (lower surface side) from which the face material was peeled to 20 mm in the thickness direction was cut out with a cutter knife to obtain a test piece for the second surface layer portion.
Further, regarding the third test piece, a test piece cut out to a width of 30 mm, a length of 30 mm, and a thickness of 100 mm, and a portion of 40 to 60 mm from one surface was cut out with a cutter knife to obtain a test piece in the central layer portion. ..
Since the air bubbles on the surface of the test piece are destroyed by cutting out the test piece with a cutter knife and the closed cell ratio cannot be measured accurately, in order to remove the surface of the test piece in which the air bubbles are destroyed, the obtained rectangular parallelepiped The surfaces (6 surfaces) of each test piece were thinly cut using a razor. At this time, it is preferable to cut with a razor as thinly as possible, so that the width is 25 mm ± 1 mm, the length is 25 mm ± 1 mm, and the thickness is 19 mm ± 1 mm. The closed cell ratio of each test piece whose surface was cut with a razor was measured and calculated as follows in accordance with the measurement method 1 of JIS K 7138: 2006. The results are shown in Table 1.
Closed cell ratio = (volume measurement result with dry densitometer) / (volume measurement result with wet densitometer) x 100
<Dry density meter>
Product name: Made by Tokyo Science Co., Ltd. Air comparison hydrometer 1000 type Model number: 1000
<Wet density meter>
Product name: LIBROR EB-330H manufactured by Shimadzu Corporation
Model number: 63572

(Calculation of average closed cell ratio)
The average closed cell ratio was calculated from the closed cell ratios of the first surface layer portion, the central layer portion, and the second surface layer portion obtained in the above (measurement of closed cell ratio). The results are shown in Table 1.

(density)
Using the test pieces of the first surface layer portion, the central layer portion, and the second surface layer portion obtained in the same manner as described above (measurement of closed cell ratio), the density of each test piece was determined by JIS A 9511: 2009. Measured according to. The results are shown in Table 1.

(Measurement of water absorption)
The amount of water absorption was measured according to JIS A 9511 using a phenol resin foam plate. The results are shown in Table 1.

(Initial thermal conductivity)
Using a phenol resin foam sample of 300 mm square in length and width, set the low temperature plate to 10 ° C and the high temperature plate to 30 ° C, and follow the "heat flow metering method" of JIS A 1412-2: 1999, and heat conductivity measuring device HC-074 304 ( Measured using Eiko Seiki Co., Ltd.). The thermal conductivity of the phenol resin foam sample after being left in an atmosphere of 70 ° C. for 4 days was defined as the initial thermal conductivity.

(Estimated value of thermal conductivity after 25 years)
Based on ISO 11561 Annex B, the maximum temperature that can occur in a building is set to 70 ° C, and the thermal conductivity after leaving a phenol resin foam sample of 300 mm square in length and width in a 70 ° C atmosphere for 25 weeks is set to 25 years later. Measured as an estimate.

(Inhibitory of deformation)
When the phenol resin foam plate was stored at 23 ° C. and 50% humidity after molding for 1 week, the degree of deformation of the phenol resin foam plate was visually observed and evaluated according to the following criteria.
◯ (excellent): No dent was observed on the side surface of the phenol resin foam plate, and no warpage was observed on the phenol resin foam plate.
Δ (Good): A slight dent was observed on the side surface of the phenol resin foam plate, or a slight warp was observed on the phenol resin foam plate.
X (defective): A remarkable dent was observed on the side surface of the phenol resin foam plate. Alternatively, a remarkable warp was observed in the phenol resin foam plate.
The results are shown in Table 1.

As shown in the above results, in Examples 1 to 13 to which the present invention was applied, the water absorption amount was 3. It was suppressed to 0 g / 100 cm ² or less, and long-term stability of thermal conductivity was obtained. Further, in Example 7, since the closed cell ratio in the central portion was low, some small edges were observed on the side surface, but in Examples 1 to 6, the closed cell ratio in the thickness direction was uniform, so that the shape was deformed. Was not observed either.
On the other hand, in Comparative Example 1, among the plurality of nozzles, the discharge amount from the nozzle at the end in the TD direction was extremely small, and the discharged resin composition moved toward the end in the foam molding apparatus. The closed cell ratio of both the surface layer portion and the second surface layer portion was less than 85%, and long-term stability of thermal conductivity could not be obtained.
In Comparative Example 2, the closed cell ratio of the second surface layer portion was less than 85%, long-term stability of thermal conductivity could not be obtained, and deformation (warpage) was confirmed.

Claims (1)

A phenolic resin foam containing a phenol resin, a hydrocarbon and a halogenated unsaturated hydrocarbon, and having a thickness of 60 mm or more and 100 mm or less.
When the phenol resin foam has a flat plate shape and is divided into three in the thickness direction to form a first surface layer portion, a central layer portion, and a second surface layer portion in order from one surface,
A closed cell content of the first surface portion, the closed cell ratio of the second surface portion state, and are 85%, respectively,
The difference between the maximum value and the minimum value of the closed cell ratio of the first surface layer portion, the closed cell ratio of the central layer portion, and the closed cell ratio of the second surface layer portion is 10% or less.
The closed cell ratio of the central layer portion is 85% or more, and the closed cell ratio is 85% or more.
The value represented by [the closed cell ratio (%) of the first surface layer portion]-[the closed cell ratio (%) of the central layer portion] is -5 to 5%.
The value represented by [the closed cell ratio (%) of the second surface layer]-[the closed cell ratio (%) of the central layer] is -5 to 5%.
A phenolic resin foam in which the mass ratio of the hydrocarbon to the halogenated unsaturated hydrocarbon is hydrocarbon: halogenated unsaturated hydrocarbon = 8: 2 to 2: 8.