JP6145209B1 - Phenol resin foam and method for producing phenol resin foam - Google Patents

Abstract

Disclosed is a phenol resin foam with suppressed deformation, and a method for producing the same. A foamed layer of a phenol resin containing a foaming agent containing a halogenated unsaturated hydrocarbon is provided, the compression elastic modulus of the foamed layer is 3.0 MPa or more, and the thickness direction of the foamed layer is second order. The average cell diameter in the divided cross section is 60 μm or more and 110 μm or less, the standard deviation of the cell diameter in the cross section is 35 μm or less, the compression elastic modulus of the foam layer, the average cell diameter in the cross section, and the bubbles in the cross section A phenol resin foam characterized in that the standard deviation of the diameter satisfies the following formula (1). Compression modulus (MPa) ÷ Average bubble diameter (μm) ÷ Standard deviation of bubble diameter (μm) × 10000 ≧ 10 (1) [Selection] None

Description

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

The phenol resin foam is excellent in flame retardancy, heat resistance, chemical resistance, corrosion resistance, and the like, and thus has been adopted in various fields as a heat insulating material. For example, in the construction field, a phenol resin foam is used as a synthetic resin building material, particularly a wallboard interior material.
The phenol resin foam is obtained by foaming and curing a phenol resin composition containing a phenol resin, a foaming agent, and the like. As the blowing agent, a halogenated unsaturated hydrocarbon having a small global warming potential (GWP) is preferably used. However, when the halogenated unsaturated hydrocarbon is mixed with a phenol resin, the viscosity of the phenol resin composition is lowered, and the bubbles at the time of foaming are likely to be coarsened or broken. When the bubbles are coarsened, the compression elastic modulus of the phenolic resin foam is lowered, and there is a problem that the screws can sink into the phenolic resin foam and cannot be fixed firmly when constructed as a heat insulating material.

  Patent Document 1 proposes a resin foam in which the variation in the size distribution of the air bubbles in the intermediate foam layer is reduced to suppress deterioration over time of the heat insulating properties.

JP 2002-292651 A

However, in Patent Document 1, no consideration is given to suppressing deformation of the resin foam.
Then, this invention aims at the phenol resin foam which suppressed the deformation | transformation, and its manufacturing method.

In order to solve the above problems, the present invention has the following aspects.
[1] A phenol resin foam layer containing a foaming agent containing a halogenated unsaturated hydrocarbon is provided, the foam layer has a compression elastic modulus of 3.0 MPa or more, and the thickness direction of the foam layer is divided into two equal parts. The average bubble diameter in the cross section is 60 μm or more and 110 μm or less, the standard deviation of the bubble diameter in the cross section is 35 μm or less, the compression elastic modulus of the foam layer, the average bubble diameter in the cross section, and the bubble diameter in the cross section The phenol resin foam characterized by satisfying the following formula (1).
Compression modulus (MPa) ÷ average bubble diameter (μm) ÷ standard deviation of bubble diameter (μm) × 10000 ≧ 10 (1)

[2] The method for producing a phenol resin foam according to [1], wherein the foamable phenol resin composition containing a phenol resin, a foaming agent containing a halogenated unsaturated hydrocarbon, and an acid catalyst is heated to foam. And after the foam curing step, and after the foam curing step, the foamable phenol resin composition is dried and further cured, and between the foam curing step and the curing step. And a cooling step for cooling the surface temperature of the foamed phenolic resin composition to 30 to 65 ° C., and the temperature difference between the atmospheric temperature in the foam curing step and the atmospheric temperature in the cooling step is 5 ° C. It is the above, The manufacturing method of the phenol resin foam characterized by the above-mentioned.

  ADVANTAGE OF THE INVENTION According to this invention, the phenol resin foam which suppressed the deformation | transformation and its manufacturing method can be provided.

[Phenolic resin foam]
The phenol resin foam of the present invention is obtained by foaming and curing a foamable phenol resin composition containing a phenol resin, a foaming agent and an acid catalyst.
The phenol resin foam of the present invention includes a foam layer formed by foaming and curing the foamable phenol resin composition.
The foamable phenol resin composition may further contain other components other than the phenol resin, the foaming agent, and the acid catalyst, as long as the effects of the present invention are not impaired.

<Phenolic resin>
As the phenol resin, a resol type resin is preferable.
The resol type phenol resin is a phenol resin obtained by reacting a phenol compound and an aldehyde in the presence of an alkali catalyst.
Examples of the phenol compound include phenol, cresol, xylenol, paraalkylphenol, paraphenylphenol, resorcinol, and modified products thereof.
Examples of aldehydes include formaldehyde, paraformaldehyde, furfural, and acetaldehyde.
Examples of the alkali catalyst include sodium hydroxide, potassium hydroxide, calcium hydroxide, aliphatic amine (trimethylamine, triethylamine, etc.) and the like. However, the phenol compound, the aldehyde, and the alkali catalyst are not limited to those described above. A phenol resin may be used individually by 1 type, and 2 or more types may be used in combination.
The ratio of a phenol compound and an aldehyde is not specifically limited. Preferably, the molar ratio of phenol compound: aldehyde is 1: 1 to 1: 3, more preferably 1: 1.3 to 1: 2.5.

<Foaming agent>
The phenol resin foam of the present invention contains a foaming agent containing a halogenated unsaturated hydrocarbon.
The halogenated unsaturated hydrocarbon has a carbon-carbon double bond and a halogen atom in the molecule.
Halogenated unsaturated hydrocarbons include fluorinated unsaturated hydrocarbons, chlorinated unsaturated hydrocarbons, chlorinated fluorinated unsaturated hydrocarbons, brominated fluorinated unsaturated hydrocarbons, iodinated fluorinated unsaturated hydrocarbons, etc. Is mentioned.
As a halogenated unsaturated hydrocarbon, a well-known thing can be used as a foaming agent, and a thing with a boiling point of -28-80 degreeC is mentioned typically.
The thermal conductivity of the halogenated unsaturated hydrocarbon is preferably 0.013 W / m · K or less, and more preferably 0.011 W / m · K or less.
2-6 are preferable and, as for carbon number of a halogenated unsaturated hydrocarbon, 2-5 are more preferable.

Examples of the halogenated unsaturated hydrocarbon include, for example, a fluorinated unsaturated hydrocarbon having a carbon-carbon double bond and a halogen atom in the molecule, a chlorinated fluorinated unsaturated hydrocarbon, and a brominated fluorinated unsaturated. Examples of the halogenated unsaturated hydrocarbon include those having a fluorine atom such as a fluorinated unsaturated hydrocarbon and a chlorinated fluorinated unsaturated hydrocarbon. The halogenated unsaturated hydrocarbon may be one in which all of hydrogen is substituted with halogen, or one in which a part of hydrogen is substituted with halogen.
These halogenated unsaturated hydrocarbons may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the fluorinated unsaturated hydrocarbon include hydrofluoroolefins having fluorine and carbon-carbon double bonds in the molecule (hereinafter also referred to as “HFO”). Examples of 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 (HFO1336mzz) (E and Z isomers) (manufactured by SynQuest Laboratories, product number: 1300-3-Z6), etc. Disclosed in (1).
These fluorinated unsaturated hydrocarbons may be used alone or in combination of two or more.

Chlorinated fluorinated unsaturated hydrocarbons include 1,2-dichloro-1,2-difluoroethene (E and Z isomers), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) ( E and Z isomers) (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 isomer), 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) (manufactured by 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 (HCFO-1223xd) (E and Z isomers), 2-chloro-1,1,1,4 4,4-hexafluoro-2-butene (E and Z isomers), 2-chloro-1,1,1,3,4,4,4-heptafluoro-2-butene (E and Z variants), etc. Is mentioned.
These chlorinated fluorinated unsaturated hydrocarbons may be used alone or in combination of two or more.

  The phenol resin foam of the present invention may contain other blowing agents other than the halogenated unsaturated hydrocarbon. Examples of other blowing agents other than the halogenated unsaturated hydrocarbon include halogenated saturated hydrocarbons such as dichloroethane and isopropyl chloride; saturated aliphatic hydrocarbons such as propane, normal butane, isopentane and cyclopentane; ethers such as dimethyl ether A carbonate such as sodium hydrogen carbonate or calcium carbonate; a chemical foaming agent such as azodicarboxylic acid amide or N, N′-dinitrosopentamethylenetetramine; a porous solid material; These foaming agents may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the foaming agent in the foamable phenol resin composition is preferably 1 part 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 more preferably 5 parts by mass or more and 12 parts by mass per 100 parts by mass of the phenol resin. More preferred is less than or equal to parts by weight. When it is at least the above lower limit value, the foamable phenol resin composition is sufficiently foamed, and the heat insulation of the phenol resin foam is easily enhanced. When the amount is not more than the above upper limit, the degree of foaming of the foamable phenolic resin composition can be suppressed, and the compression modulus of the phenolic resin foam can be easily increased.

<Acid catalyst>
The acid catalyst is used to initiate the polymerization 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 singly or in combination of two or more.

  The content of the acid catalyst in the foamable phenolic resin composition is preferably 5 to 30 parts by mass, more preferably 8 to 25 parts by mass, more preferably 10 to 20 parts by mass per 100 parts by mass of the phenol resin. More preferred is less than or equal to parts by weight. If the amount is larger than the above upper limit, the water absorption amount of the phenol resin is deteriorated. When it is less than the lower limit, the polymerization reaction of the phenol resin is slow, and the production time is long.

<Optional component>
The foamable phenol resin composition may contain components (arbitrary components) other than the phenol resin, the foaming agent, and the acid catalyst. Examples of optional components include surfactants, foam nucleating agents, urea, fillers (fillers), plasticizers, crosslinking agents, organic solvents, amino group-containing organic compounds, and colorants.

(Surfactant)
The surfactant contributes to the refinement of the cell diameter (cell diameter).
The surfactant is not particularly limited, and those known as foam stabilizers can be used. For example, castor oil alkylene oxide adduct, silicone surfactant, polyoxyethylene sorbitan fatty acid ester and the like can be mentioned. These surfactants may be used singly or in combination of two or more.
The surfactant preferably contains one or both of a castor oil alkylene oxide adduct and a silicone-based surfactant because it is easy to form bubbles having a small cell diameter, and has a lower thermal conductivity and flame retardancy. It is more preferable that a silicone-based surfactant is included in that it can be made higher.

The alkylene oxide in the castor oil alkylene oxide adduct is preferably an alkylene oxide having 2 to 4 carbon atoms, more preferably ethylene oxide (hereinafter abbreviated as “EO”) or propylene oxide (hereinafter abbreviated as “PO”). Preferably, EO is more preferable. The alkylene oxide added to the castor oil may be one type or two or more types.
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 moles and less than 60 moles, more preferably 21 to 40 moles per mole of castor oil. In such a castor oil alkylene oxide adduct, a polyoxyalkylene group (polyoxyethylene group or the like) formed by a hydrophobic group mainly composed of a long-chain hydrocarbon group of castor oil and a predetermined addition mole of alkylene oxide (EO or the like). The hydrophilic group mainly composed of is arranged in a well-balanced manner in the molecule and exhibits a good surface activity. For this reason, the bubble diameter of a phenol resin foam becomes small. Moreover, a softness | flexibility is provided to the cell wall of a phenol resin foam, and generation | occurrence | production of a crack is prevented.

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

Examples of the copolymer of dimethylpolysiloxane and polyether include dimethylpolysiloxane-polyoxyalkylene copolymer.
As for carbon number of the oxyalkylene group in polyoxyalkylene, 2 or 3 is preferable.
The oxyalkylene group constituting the polyoxyalkylene may be one type or two or more types.
Specific examples of the dimethylpolysiloxane-polyoxyalkylene copolymer include dimethylpolysiloxane-polyoxyethylene copolymer, dimethylpolysiloxane-polyoxypropylene copolymer, dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymer. A polymer etc. are mentioned.

  As the copolymer of dimethylpolysiloxane and polyether, those having a polyether chain whose terminal is -OR (wherein R is a hydrogen atom or an alkyl group) are preferred, and the thermal conductivity is more favorable. In view of reduction, it is particularly preferable that R is a hydrogen atom.

The content of the surfactant in the foamable phenol resin composition is preferably 1 part by mass or more and 10 parts by mass or less, more preferably 2 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the phenol resin. If the content of the surfactant is not less than the above lower limit value, the bubble diameter tends to be uniform and fine. If it is below the said upper limit, the water absorption of a phenol resin foam will become low and manufacturing cost will also be suppressed.
In the foamable phenol resin composition, the mass ratio represented by the foaming agent: surfactant is preferably, for example, 1: 1 to 6: 1. If 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. When the ratio of the foaming agent is not less than the above lower limit, the foamable phenol resin composition can be sufficiently foamed. When the ratio of the foaming agent is not more than the above upper limit value, the foaming agent in the foamable phenol resin composition is sufficiently easily dispersed.

(Foaming nucleating agent)
Examples of the foam nucleating agent include low-boiling substances such as nitrogen, helium, argon, and air. By using the foam nucleating agent, the bubbles in the phenol resin foam can be made more uniform and fine.
The content of the foam nucleating agent in the foamable phenolic resin composition is preferably 0.05 mol% or more and 5 mol% or less with respect to the foaming agent.

(urea)
Urea is used as a formaldehyde catcher agent that traps formaldehyde when foaming a foamable phenolic resin composition to produce a foam.

(filler)
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 metal 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, 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; sulfuric acid Examples 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 content of the filler in the foamable phenolic resin composition is preferably such that the pH is 3 or more and less than 7, more preferably 4 or more and less than 6, and even more preferably 5 or less and less than 6. For example, the content of the filler is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, and more preferably 3 to 15 parts by mass per 100 parts by mass of the phenol resin. More preferred is 5 to 10 parts by mass. It becomes easy to suppress that pH of a phenol resin foam falls that content of a filler is the said lower limit or more. If the pH is suppressed to be low, the acidity can be suppressed, so that it is easy to suppress the corrosion of the material in contact with the phenol resin foam. When the filler content is not more than the above upper limit value or the pH is less than 7, the curing reaction by the acid catalyst is likely to proceed, and the productivity is likely to be improved.

[Method for producing foamable phenolic resin composition]
A foamable phenol resin composition is prepared by mixing a phenol resin, a foaming agent, an acid catalyst, and an arbitrary component as needed.
The order of mixing the components is not particularly limited. For example, optional components may be added to and mixed with the phenol resin as necessary, and a foaming agent and an acid catalyst are added to the resulting mixture, and this composition is supplied to a mixer. And stirring to prepare a foamable phenolic resin composition.

[Method for producing phenolic resin foam]
The foamed phenolic resin composition of the present invention can be produced by foaming and curing the foamable phenolic resin composition.
A phenol resin foam is manufactured by a well-known manufacturing method. For example, the phenol resin foam is obtained by heating and foaming and curing the foamable phenol resin composition, and after the foam curing process, the foamable phenol resin composition is dried and further cured. It can manufacture with the manufacturing method of the phenol resin foam which has a curing process. Furthermore, it has a cooling process which cools the said foamable phenol resin composition between the said foam hardening process and the said curing process.
In the present embodiment, in the foam curing step, the heating time is set short in order to suppress excessive foaming of the foamable phenol resin composition. The foamable phenol resin composition after the foam curing step may not be sufficiently cured. Therefore, a curing process is provided to cure the foamable phenolic resin composition.

<Foam curing process>
The foam curing step is a step of heating and foaming and curing the foamable phenol resin composition. The foam curing step is performed, for example, in a foaming furnace.
30 to 95 degreeC is preferable, as for the atmospheric temperature in a foam hardening process, 40 to 90 degreeC is more preferable, and 50 to 85 degreeC is further more preferable. By setting it as more than the said lower limit, foaming of a foamable phenol resin composition can be advanced moderately easily. By setting it to the upper limit value or less, excessive foaming of the foamable phenol resin composition can be suppressed.
At this time, the surface temperature of the foamable phenol resin composition is preferably 30 ° C. or higher and 90 ° C. or lower, more preferably 40 ° C. or higher and 85 ° C. or lower, and further preferably 50 ° C. or higher and 80 ° C. or lower. By setting it as more than the said lower limit, foaming of a foamable phenol resin composition can be advanced moderately easily. By setting it to the upper limit value or less, excessive foaming of the foamable phenol resin composition can be suppressed.
At this time, the temperature of the central portion (near the center in the thickness direction) of the foamable phenol resin composition is preferably 35 ° C. or higher and 90 ° C. or lower, more preferably 45 ° C. or higher and 85 ° C. or lower, and 55 ° C. More preferably, the temperature is 80 ° C. or lower. By setting it as more than the said lower limit, foaming of a foamable phenol resin composition can be advanced moderately easily. By setting it to the upper limit value or less, it is possible to suppress the coarsening of the cell diameter of the central cell.
In addition, the temperature difference between the temperature of the central portion and the surface temperature is preferably 10 ° C. or less, more preferably 8 ° C. or less, further preferably 5 ° C. or less, and most preferably 0 ° C. If the temperature difference is within the above range, it is easy to make the cell bubble diameter uniform. When the cell bubble diameter is uniform, the compression elastic modulus of the phenol resin foam is easily increased.

  The heating time of the foamable phenol resin composition in the foam curing step is preferably from 200 seconds to 400 seconds, and more preferably from 250 seconds to 350 seconds. By setting it as more than the said lower limit, foaming of a foamable phenol resin composition can be advanced moderately easily. By setting it to the upper limit value or less, excessive foaming of the foamable phenol resin composition can be suppressed.

The temperature of the surface and center part of a foamable phenol resin composition is measured as follows.
When discharging the foamable phenolic resin composition, button-type temperature loggers (KN Laboratories Super Thermocron) are installed at the top, center, and bottom, respectively. The upper part is attached to the upper face material with double-sided tape, and the lower part is attached to the lower face material with double-sided tape. At the center, install the base so that the thickness of the foamable phenolic resin composition is at the center, attach the logger to the base with double-sided tape, and attach the legs of the base to the upper surface of the lower face material (resin composition Fasten to the surface that contacts the object. The maximum temperature of each part of the foamable phenol resin composition in the foam curing step is measured with a button-type temperature logger. The measurement interval is 2 seconds.

When producing a phenolic resin foam by foam molding, a face material may be provided.
The face material is not particularly limited, and glass fiber nonwoven fabric, glass fiber mixed paper, synthetic fiber nonwoven fabric made of polyester / polypropylene / nylon, spunbond nonwoven fabric, aluminum foil-clad nonwoven fabric, metal plate, metal foil, plywood, calcium silicate At least one selected from a board, a gypsum board, and a wood cement board is preferable.

Although the thickness of a face material is not specifically limited, For example, in the case of synthetic fiber nonwoven fabrics, such as a polyester nonwoven fabric, 0.1 mm or more and 0.25 mm or less are preferable. In the case of papers such as glass fiber mixed paper, 0.1 mm to 1.0 mm is preferable. In the case of a glass fiber nonwoven fabric, it is preferably from 0.1 mm to 1.0 mm.
Basis weight of the surface material is not particularly limited, when using a synthetic fiber nonwoven fabric, it is preferably 15 g / ^{m 2} or more 200 g / ^{m 2} or less, 15 g / ^{m 2} or more 150 g / ^{m 2} or less more preferably, 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} that less is Is most preferred.
When glass fiber mixed paper is used, the basis weight 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. More preferably, it is 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 nonwoven fabric is used, the basis weight 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 more preferably 30 g / m ² or more and 150 g. / M ² or less is more preferable.

The face material may be provided on one side of the foam layer or 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 phenolic resin foam, for example, a face material is disposed on a conveyor belt that continuously runs, and a foamable phenol resin composition is discharged onto the face material, on which the face material is disposed. After laminating other face materials, a method of foam molding by passing through a foaming furnace can be mentioned. Thereby, the phenol resin foam with a face material which face material laminated | stacked on both surfaces of the plate-shaped foam layer is obtained.
The face material may be provided by being bonded to the foam layer using an adhesive after foam molding.

<Curing process>
The curing step is a step of drying and further curing the foamable phenolic resin composition after the foam curing step. The curing process is performed, for example, in a curing cabinet.
In this embodiment, after stopping the heating in the foam curing step, the time after the heating is referred to as the curing step. Or in this embodiment, the process after a foamable phenol resin composition reaches | attains a desired expansion ratio and a polymerization degree is called a curing process.
In the present specification, the foamable phenol resin composition cured after the curing process is referred to as a phenol resin foam.
The atmosphere temperature in the curing step is preferably 50 ° C. or higher and 110 ° C. or lower, more preferably 55 ° C. or higher and 105 ° C. or lower, and further preferably 60 ° C. or higher and 100 ° C. or lower. By setting the atmospheric temperature in the curing process within the above range, a phenol resin foam having a desired density and average cell diameter can be easily obtained.
In the curing step, the curing time is preferably 2 hours or more and 18 hours or less, more preferably 2 hours or more and 15 hours or less, and further preferably 2 hours or more and 12 hours or less. By setting it to the above lower limit value or more, a sufficiently cured phenol resin foam can be easily obtained. The productivity of a phenol resin foam can be improved by setting it as the said upper limit or less.

<Cooling process>
The cooling step is a step of cooling the foamable phenol resin composition to suppress foaming.
In the present embodiment, the time from when the heating in the foam curing process is stopped and the cooling is started to the time before the heating is again referred to as the cooling process. Alternatively, in the present embodiment, after reaching the desired expansion ratio and degree of polymerization, until the time of heating again is referred to as a cooling step.
In the cooling step, it is preferable to cool the foamed phenolic resin composition taken for 60 to 300 seconds until the surface temperature of the foamable phenolic resin composition reaches 30 to 65 ° C.
By cooling, it is possible to suppress the bubble diameter of the cell at the center from becoming coarser, so that the bubble diameter can be made uniform easily. By making the bubble diameter uniform, it is easy to reduce variations in the bubble diameter.
A cooling process may be provided in a foaming furnace, and may be provided in a curing warehouse. Moreover, you may provide in the place different from a foaming furnace and a curing warehouse.
After the cooling step, the foamable phenol resin composition is sent to the curing step, dried and further cured to obtain a phenol resin foam.

  If the temperature difference between the atmospheric temperature in the foam curing step and the atmospheric temperature in the cooling step is 5 ° C. or more, it is easy to reduce the temperature difference between the center portion and the surface portion of the foamable phenol resin composition, and the desired density and average Since the phenol resin foam of a cell diameter is easy to be obtained, it is preferable.

The compression elastic modulus of the foamed layer of the phenol resin foam of the present invention is 3.0 MPa or more, preferably 3.5 MPa or more, and more preferably 4.0 MPa or more. If the compression modulus is equal to or higher than the lower limit, it is easy to suppress the deformation of the phenol resin foam during construction of the heat insulating material.
The compression modulus can be measured according to JIS K 7220: 2006.
The compression elastic modulus 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 density of the phenolic foam of the present invention is preferably from 15 kg / ^{m 3} or more 50 kg / ^{m 3} or less, more preferably 20 kg / ^{m 3} or more 40 kg / ^{m 3} or less, 25 kg / ^{m 3} or more 35 kg / ^{m 3} or less is more preferable. If it is more than the said lower limit, it will be easy to aim at the further improvement of the compression elastic modulus of a phenol resin foam, and if it is below the said upper limit, it will be easy to aim at weight reduction of a phenol resin foam.
The 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 average cell diameter in a cross section obtained by dividing the thickness direction of the foamed layer into two is preferably 50 μm or more and 200 μm or less, more preferably 50 μm or more and 150 μm or less, and further preferably 60 μm or more and 110 μm or less. If the average cell diameter is not less than the above lower limit, low thermal conductivity can be maintained over a long period of time. When the average cell diameter is not more than the above upper limit, the compression elastic modulus of the phenol resin foam is likely to be increased.
In the present invention, the cross section obtained by dividing the thickness direction of the foam layer into two equal parts may be the cross section of the upper foam layer divided into two equal parts, or the cross section of the lower foam layer divided into two equal parts. May be.
The average cell diameter can be measured by the following method.

<Measurement method of average bubble diameter>
The thickness direction of the foam layer of the phenol resin foam is bisected. The cut surface is photographed at 50 times magnification. Draw four straight lines with a length of 9 cm on the captured image. At this time, a straight line is 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 K 6400-1: 2004) is counted for each straight line, and the average value per straight line is obtained. 1800 μm is divided by the average value of the number of bubbles, and the obtained value is defined as the average bubble size.
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.

The standard deviation of the bubble diameter in the cross section obtained by dividing the thickness direction of the foamed layer into two is preferably 35 μm or less, and more preferably 30 μm or less. It is ideal that the standard deviation of the bubble diameter is substantially 0 μm, but it is difficult and stable to manufacture stably as such. When the standard deviation is within the above range, the compression elastic modulus of the phenol resin foam is easily increased. As described above, since the average cell diameter of the portion closer to the center of the phenol resin foam is larger than the average cell diameter of the surface layer, the standard deviation of the cell diameter is larger in the portion closer to the center than the surface layer. .
The standard deviation of the bubble diameter was calculated as follows.

<Calculation method of standard deviation of bubble diameter>
The thickness direction of the foam layer of the phenol resin foam is bisected. The cut surface is photographed at 100 times magnification. In the photographed image, a bubble within an arbitrary 10 cm square is circularly approximated. The bubble diameters of the circularly approximated bubbles are measured, and the results are statistically calculated to calculate the standard deviation.
The standard deviation of the 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.

It is preferable that the compression elastic modulus of the foam layer, the average cell diameter in a section obtained by dividing the foam layer in the thickness direction, and the standard deviation of the cell diameter in the section satisfy the following formula (1).
Compression elastic modulus (MPa) ÷ average bubble diameter (μm) ÷ bubble diameter standard deviation (μm) × 10000 ≧ 10 (1)
In the present invention, when the value of the left side of the formula (1) is 10 or more, the compression elastic modulus of the phenol resin foam is good, and it is easy to suppress the occurrence of dents during construction of the heat insulating material.

In the phenol resin foam of the present invention, a plurality of bubbles are formed, the bubble wall is substantially free of pores, and at least some of the plurality of bubbles are closed cells that are not in communication with each other. It has become. In the closed cells, a halogenated unsaturated hydrocarbon gas used as a blowing agent is retained. The closed cell ratio is preferably 85% or more, more preferably 90% or more. The upper limit value is not particularly limited, but is substantially 99% or less. If it is in the said numerical range, low thermal conductivity can be maintained over a long period of time.
The closed cell ratio is measured according to JIS K 7138: 2006.

The thermal conductivity of the phenol resin foam is preferably 0.019 W / m · K or less, more preferably 0.0185 W / m · K or less, and still more preferably 0.018 W / m · K or less. If heat conductivity is 0.019 W / m * K or less, it is excellent in heat insulation.
The thermal conductivity can be measured according to JIS A 1412-2.
The thermal conductivity 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.

As above-mentioned, the phenol resin foam of this embodiment is excellent by heat insulation by using a specific foaming agent. For this reason, the phenol resin foam of this embodiment is particularly useful as a heat insulating material for buildings that require high heat insulating properties such as apartment houses, detached houses, and warehouses.
In addition, the phenol resin foam of this embodiment can suppress deformation.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

[Example 1]
Liquid resol type phenolic resin (Asahi Organic Materials Co., Ltd., trade name: PF-339) 100 parts by mass, surfactant (castor oil EO adduct (added mole number 30)) 4 parts by mass, formaldehyde catcher agent ( After mixing 4 parts by mass of urea), it was left at 20 ° C. for 8 hours.
108 parts by mass of the obtained mixture, 15 parts by mass of a foaming agent having the composition shown in Table 1, and 17 parts by mass of an acid catalyst (a mixture of paratoluenesulfonic acid and xylenesulfonic acid) were mixed to obtain a foamable phenol resin composition. Prepared.
This foamable phenolic resin composition is discharged from 16 nozzles arranged at equal intervals in the width direction onto the first face material (material: polyester nonwoven fabric, basis weight: 30 g / m ² ) that is continuously running. Then, a second face material (the same as the first face material) was stacked thereon, introduced into a slat type double conveyor, and heated at 75 ° C. for 260 seconds to perform foam molding (foam curing step). After the foam curing step, the product was cooled at 40 ° C. for 180 seconds (cooling step) and then dried at 80 ° C. for 6 hours (curing step) to prepare a phenol resin foam. The obtained phenol resin foam was cut into a width of 910 mm and a length of 1820 mm to prepare a 45 mm thick phenol resin foam plate (plate-like phenol resin foam).

[Examples 2 to 8]
A phenol resin foam board was produced in the same manner as in Example 1 with the foaming agent composition shown in Table 1, the temperature and time of each step.

[Comparative Examples 1-3]
A phenolic resin foam board was produced in the same manner as in Example 1 with the foaming agent composition shown in Table 2, the temperature and time of each step.

  For the phenol resin foam of each example, density, average cell diameter, standard deviation of cell diameter, closed cell rate, thermal conductivity, compression modulus, compression modulus (MPa) ÷ average cell size (μm) ÷ cell size The value of standard deviation (μm) × 10000 was measured or calculated, and the presence or absence of occurrence of abnormality due to screwing was evaluated. The results are shown in Tables 1-2.

<Screw test>
A phenolic resin foam plate was placed on a wooden cross and fixed with M6 screws (the bearing surface was φ16). Screws were screwed in until the seat surface sinks 1 mm from the surface of the phenolic resin foam plate. The surface state of the foamed plate was evaluated according to the following evaluation criteria.
<Evaluation criteria>
○: No abnormalities such as cracks occur on the surface of the foam plate.
X: Abnormalities such as cracks occur on the surface of the foam plate.

In Examples 1 to 8 to which the present invention was applied, all were ○ in the screwing test, and it was found that the deformation of the phenol resin foam was easily suppressed.
On the other hand, in Comparative Examples 1-3, it turned out that the deformation | transformation of a phenol resin foam has not been suppressed compared with the Example to which this invention is applied.

  According to the present invention, it has been found that a phenol resin foam with suppressed deformation and a method for producing the same can be provided.

Claims (2)

A phenolic resin foam layer containing a foaming agent containing a halogenated unsaturated hydrocarbon , and a face material laminated on the foam layer ,
The halogenated unsaturated hydrocarbon is either 1,1,1,4,4,4-hexafluoro-2-butene or 1-chloro-3,3,3-trifluoropropene;
The face material is a polyester nonwoven fabric ( excluding those having a fragile air permeability of 50 cm ³ / cm ² · sec or less),
The compression elastic modulus of the foam layer is 3.0 MPa or more,
The average cell diameter in a section obtained by dividing the thickness direction of the foam layer into two equal parts is 60 μm or more and 110 μm or less,
The standard deviation of the bubble diameter in the cross section is 35 μm or less,
The phenol resin foam, wherein the compression elastic modulus of the foam layer, the average cell diameter in the cross section, and the standard deviation of the cell diameter in the cross section satisfy the following formula (1).
Compression modulus (MPa) ÷ average bubble diameter (μm) ÷ standard deviation of bubble diameter (μm) × 10000 ≧ 10 (1) In a cross-section comprising a foamed layer of a phenol resin containing a foaming agent containing a halogenated unsaturated hydrocarbon, wherein the foamed layer has a compression elastic modulus of 3.0 MPa or more, and the thickness direction of the foamed layer is divided into two equal parts. The average bubble diameter is 60 μm or more and 110 μm or less, the standard deviation of the bubble diameter in the cross section is 35 μm or less, the compression elastic modulus of the foam layer, the average bubble diameter in the cross section, and the standard deviation of the bubble diameter in the cross section Is a method for producing a phenol resin foam satisfying the following formula (1) ,
A foam curing step in which a foamable phenol resin composition containing a phenol resin, a foaming agent containing a halogenated unsaturated hydrocarbon and an acid catalyst is heated, foamed and cured;
After the foam curing step, the foaming phenol resin composition is dried and further cured.
Between the foam curing step and the curing step, further has a cooling step of cooling the surface temperature of the foamed foamable phenolic resin composition to 30 to 65 ° C,
A method for producing a phenol resin foam, wherein a temperature difference between an atmospheric temperature in the foam curing step and an atmospheric temperature in the cooling step is 5 ° C. or more.
Compression modulus (MPa) ÷ average bubble diameter (μm) ÷ standard deviation of bubble diameter (μm) × 10000 ≧ 10 (1)