JP6832143B2 - Method for producing phenol resin foam and phenol resin foam - Google Patents

Description

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

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

For example, a phenol resin foam ^{having a density of 80 to 300 kg / m 3} containing a foaming agent composed of halogenated hydrocarbons such as trichlorofluoromethane and trichlorotrifluoroethane, an antifoaming agent, a foam stabilizer, and a curing agent. The body is known (Patent Document 1). However, since the phenol resin foam has a high density, it has high thermal conductivity, and it is difficult to obtain excellent heat insulating properties.

Further, a phenol resin foam in which voids are reduced by using one or both of chlorinated hydrofluoroolefin and non-chlorinated hydrofluoroolefin as a foaming agent and adjusting the viscosity of the phenol resin has also been proposed. (Patent Document 2). However, it is difficult to reduce voids only by adjusting the viscosity with the molecular weight and water content of the phenol resin, and it is difficult to obtain sufficient compressive strength.

Japanese Unexamined Patent Publication No. 63-72737 Japanese Unexamined Patent Publication No. 2015-157937

An object of the present invention is to provide a phenol resin foam having excellent heat insulating properties and sufficient compressive strength, and a method for producing the same.

The present invention has the following configurations.
[1] A phenol resin foam containing a phenol resin, a foaming agent, and a defoaming agent, wherein the foaming agent contains a hydrofluoroolefin and has a density of 20 kg / m ³ or more and 45 kg / m ³ or less. A phenolic resin foam having an average cell diameter of 50 μm or more and 200 μm or less, a closed cell ratio of 80% or more, and a void area ratio of 1% or less.
[2] The phenolic resin foam according to [1], which has a thermal conductivity of less than 0.0190 W / m · K.
[3] The phenolic resin foam according to [1] or [2], wherein the defoaming agent is a silicone-based defoaming agent.
[4] The method for producing a phenol resin foam according to any one of [1] to [3], at least selected from the group consisting of a phenol resin, a chlorinated hydrofluoroolefin and a non-chlorinated hydrofluoroolefin. A method for producing a phenol resin foam, which comprises foaming and curing a phenol resin composition containing a foaming agent containing one type and an antifoaming agent.

The phenolic resin foam of the present invention has excellent heat insulating properties and sufficient compressive strength.
According to the method for producing a phenol resin foam of the present invention, a phenol resin foam having excellent heat insulating properties and sufficient compressive strength can be obtained.

It is a schematic block diagram which showed an example of the conveyor device used for manufacturing the phenol resin foam of this invention. FIG. 1 is a cross-sectional view taken along the line II of the conveyor device of FIG.

[Phenol resin foam]
The phenol resin foam of the present invention is a phenol resin foam obtained by foaming and curing a phenol resin composition containing a phenol resin, a foaming agent, and a defoaming agent between a pair of face materials. It should be noted that the face material is bonded by the adhesiveness of the phenol resin composition itself without using an adhesive.

As the phenol resin, a resol type phenol 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 alkaline catalyst.

The phenol compound is not particularly limited, and examples thereof include phenol, cresol, xylenol, paraalkylphenol, paraphenylphenol, resorcinol, and modified products thereof. As the phenol compound, one type may be used alone, or two or more types may be used in combination.
The aldehyde is not particularly limited, and examples thereof include formaldehyde, paraformaldehyde, furfural, and acetaldehyde. As the aldehyde, one type may be used alone, or two or more types may be used in combination.

The alkali catalyst is not particularly limited, and examples thereof include sodium hydroxide, potassium hydroxide, calcium hydroxide, aliphatic amines (trimethylamine, triethylamine, etc.) and the like. As the alkaline catalyst, one type may be used alone, or two or more types may be used in combination.

The ratio of the phenol compound to the aldehyde is not particularly limited, and the molar ratio of the phenol compound: aldehyde is preferably 1: 1 to 1: 3, and more preferably 1: 1.3 to 1: 2.5.

The weight average molecular weight (Mw) of the phenol resin is preferably 400 or more and 3000 or less, and more preferably 700 or more and 2000 or less. When the Mw of the phenol resin is at least the lower limit value, the closed cell ratio tends to be increased, which tends to improve the long-term performance of the compressive strength and the thermal conductivity. In addition, the number of voids is reduced, and a foam having a small average cell diameter is likely to be formed. When the Mw of the phenol resin is not more than the upper limit, it is possible to prevent the viscosity of the phenol resin raw material and the phenol resin composition from becoming too high, and it is possible to reduce the amount of the foaming agent required to obtain a sufficient foaming ratio, which is economical. It is advantageous.
The Mw of the phenol resin is determined by gel permeation chromatography.

The foaming agent contains a hydrofluoroolefin (hereinafter referred to as "HFO"). HFOs include chlorinated hydrofluoroolefins (hereinafter referred to as "chlorinated HFOs") and non-chlorinated hydrofluoroolefins (hereinafter referred to as "non-chlorinated HFOs"), and only chlorinated HFOs are used as foaming agents. It may be used, only the non-chlorinated HFO may be used, or both the chlorinated HFO and the non-chlorinated HFO may be used.

Chlorinated HFO contains a hydrogen atom, a chlorine atom, a fluorine atom and an olefin (carbon-carbon double bond) in the molecule.
Examples of the chlorinated HFO include 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) (E and Z isomers) (for example, 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-trifluoropropene (HCFO-1233xe) (E and Z isomers), 2-chloro-2,2,3-trifluoropropene (HCFO-1233xc), 2-chloro-3, 3,3-Trifluoropropene (HCFO-1233xf) (for example, 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-trifluoro Propen (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 , 1,1,3,4,5,4-heptafluoro-2-butene (E and Z variants) and the like. As the chlorinated HFO, only one type may be used, or two or more types may be used in combination.

Non-chlorinated HFO is an olefin in which a part of hydrogen atoms bonded to carbon atoms is replaced with fluorine atoms and has hydrogen atoms bonded to carbon atoms, and a part of hydrogen atoms is other than chlorine atoms. It may be substituted with a halogen atom.
Examples of the non-chlorinated HFO include 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,3,3,3-tetrafluoropropene (HFO-1234ze) (E and Z isomers), and the like. Special Table 2009 such as 1,1,1,4,4,4-hexafluoro-2-butene (HFO1336mzz) (E and Z isomers) (for example, manufactured by SynQuest Laboratories, product number: 1300-3-Z6). Examples thereof include hydrofluoroolefins disclosed in JP-A-513812. As the non-chlorinated HFO, a brominated hydrofluoroolefin, an iodinated hydrofluoroolefin or the like may be used. Among them, as the non-chlorinated HFO, a hydrofluoroolefin composed of a carbon atom, a hydrogen atom and a fluorine atom and having a double bond is preferable. As the non-chlorinated HFO, only one type may be used, or two or more types may be used in combination.

Chlorinated HFOs and non-chlorinated HFOs are advantageous in that they have a small ozone depletion potential (ODP) and a global warming potential (GWP) and have a small impact on the environment.

The foaming agent has an unsaturated bond with other halogen atoms other than the chlorinated HFO and the non-chlorinated HFO in addition to the chlorinated HFO and the non-chlorinated HFO as long as the effect of the present invention is not impaired. A foaming agent may be used. Examples of other foaming agents include those in which all hydrogen atoms of the olefin are replaced with halogen atoms, such as 1,2-dichloro-1,2-difluoroethane (E and Z isomers).

As other foaming agents, halogenated saturated hydrocarbons and hydrocarbons may be used.
As the halogenated saturated hydrocarbon, a known foaming agent can be used, and examples thereof include fluorinated saturated hydrocarbons and chlorinated saturated hydrocarbons. The halogenated saturated hydrocarbon may have all hydrogen atoms substituted with halogen atoms, or may have some hydrogen atoms substituted with halogen atoms. As the halogenated saturated hydrocarbon, one type may be used alone, or two or more types may be used in combination.

The chlorinated saturated hydrocarbon is more preferably a chlorinated aliphatic hydrocarbon having 2 to 5 carbon atoms, and examples thereof include dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride. .. Of these, isopropyl chloride is preferable because it has a low ozone depletion potential and is excellent in environmental compatibility.

The fluorinated saturated hydrocarbon preferably has 1 to 5 carbon atoms. For example, difluoromethane (HFC32), 1,1,1,2,2-pentafluoroethane (HFC125), 1,1,1-trifluoroethane (HFC143a), 1,1,2,2-tetrafluoroethane ( HFC134), 1,1,1,2-tetrafluoroethane (HFC134a), 1,1-difluoroethane (HFC152a), 1,1,1,2,3,3,3-heptafluoropropane (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.

As the hydrocarbon, for example, a cyclic or chain hydrocarbon having 3 to 7 carbon atoms or an unsaturated hydrocarbon can be used as the foaming agent. Specifically, the foaming agent contains compounds such as normalbutane, isobutane, cyclobutane, normalpentane, isopentane, cyclopentane, neopentane, normalhexane, isohexane, 2,2-dimethylbutane, 2,3-dimethylbutane, and cyclohexane. It can be. Among them, compounds selected from pentanes such as normal pentane, isopentane, cyclopentane and neopentane, and butanes such as normal butane, isobutane and cyclobutane are preferable.

Other foaming agents include low boiling gases such as nitrogen, argon, carbon dioxide, and air; sodium hydrogencarbonate, sodium carbonate, calcium carbonate, magnesium carbonate, azodicarboxylic acid amide, azobisisobutyronitrile, azodicarboxylic acid. Chemical foaming agents such as barium, N, N'-dinitrosopentamethylenetetramine, p, p'-oxybisbenzenesulfonylhydrazide, trihydrazinotriazine; even if a porous solid material such as phenol resin foam powder is used. Good.

The composition of the foaming agent contained in the phenol resin foam can be confirmed, for example, by 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. Types of chlorinated HFO, non-chlorinated HFO, etc. are identified from the retention time and mass spectrum obtained in advance. 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.

The defoaming agent has three types: a defoaming action that destroys the gas-liquid interface of the generated bubbles, a defoaming action that suppresses the generation of the gas-liquid interface itself, and a degassing action that coalesces the generated bubbles. The defoaming agent may be in a liquid state or in a solid state.
The liquid defoamer is not particularly limited, and for example, a mineral oil defoamer, an oil / fat defoamer, a fatty acid defoamer, a fatty acid ester defoamer, an alcohol defoamer, and an ether defoamer. Examples thereof include foaming agents, amide-based defoaming agents, phosphoric acid ester-based defoaming agents, metal soap-based defoaming agents, and silicone-based defoaming agents. Of these, a silicone-based antifoaming agent is preferable. As the defoaming agent, one type may be used alone, or two or more types may be used in combination.

Examples of the mineral oil-based defoaming agent include kerosene and liquid paraffin.

Examples of the oil-based defoaming agent include vegetable oils and fats such as sesame oil and castor oil, and animal oils and fats.

Examples of the fatty acid-based antifoaming agent include oleic acid and stearic acid.

Examples of the fatty acid ester antifoaming agent include diethylene glycol laurylate, glycerin monolithinolate, succinic acid derivative, sorbitol monolaurylate, polyoxyethylene monolaurylate, and polyoxyethylene sorbitol monolaurylate laurylate.

Examples of alcohol-based defoamers include lower to higher alcohols such as methanol, ethanol, isopropyl alcohol, octyl alcohol, hexadecyl alcohol, nonylphenol, acetylene alcohol, polyethylene glycol, polypropylene glycol, polyalkylene glycol, and polyoxyalkylene glycol. Examples include polyhydric alcohol.

As ether-based defoaming agents, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene behenyl ether, polyoxyethylene myristyl ether, nonylphenol ethoxylate, polyoxy Examples thereof include ethylene dodecylphenyl ether.

Examples of the amide-based defoaming agent include polyoxyalkylene amides and acrylate polyamines.

Examples of the phosphoric acid ester antifoaming agent include tributyl phosphate and sodium octyl phosphate.

Examples of the metal soap-based defoaming agent include aluminum stearate and calcium oleate.

Examples of the silicone-based defoaming agent include silicone oil, modified silicone oil, silicone paste, silicone emulsion, and fluorosilicone oil. In particular, as silicone oil and modified silicone oil, 3 to pentameric cyclic silicone, aryl-modified polysiloxane, alkyl-modified polysiloxane, amino group-modified polysiloxane, polyoxyethylene on the side chain and terminal of dimethylpolysiloxane, and poly Examples thereof include polyether-modified polysiloxane having a polyether chain composed of a polyoxyalkylene having 2 to 4 carbon atoms such as oxypropylene or a copolymer thereof, and the polyether-modified polysiloxane has a side chain length and type. It is preferable to change the HLB value because it is easy to adjust. Didimethylpolysiloxane is usually used as the polysiloxane that serves as the main chain.

Examples of the solid defoaming agent include those obtained by adsorbing the above-mentioned defoaming agent, for example, silicone oil, on powdered silica.
As the defoaming agent, a liquid form and a solid form may be used in combination.

The HLB value of the defoamer is preferably 2 or more and 9 or less, and more preferably 3 or more and 8 or less. When the HLB value of the defoaming agent is less than 2, the defoaming action is strong, uniform foaming of the foaming agent is hindered, and the average cell diameter becomes coarse. When the HLB value exceeds 9, the emulsifying action is superior to the defoaming action, and the effect of suppressing the formation of voids cannot be obtained.

Here, the HLB value is a concept representing the balance between hydrophilic groups and hydrophobic groups in the molecule, and the HLB value of polyether-modified polysiloxane is "property and application of surfactant" (author Takao Karimei, published). Tokoro Koshobo Co., Ltd., published on September 1, 1980) can be calculated as follows using the "HLB measurement method by emulsification test" described on pages 89 to 90.

<Measurement method of HLB value by emulsification test of polyether-modified polysiloxane>
Polyether-modified polysiloxane X having an unknown HLB value and emulsifier A having a known HLB value are mixed in different ratios to emulsify an oil agent having a known HLB value. The HLB value of the polyether-modified polysiloxane X is calculated from the mixing ratio when the thickness of the emulsified layer is maximized using the following formula.

Oil agent HLB = {(WA x HLBA) + (WX x HLBX)} ÷ (WA + WX)

WA is the weight fraction of emulsifier A based on the total weight of polyether-modified polysiloxane X and emulsifier A, and WX is the weight fraction of polyether-modified polysiloxane X based on the total weight of polyether-modified polysiloxane X and emulsifier A. HLBA is the HLB value of emulsifier A, and HLBX is the HLB value of polyether-modified polysiloxane X.

As a method for detecting the defoaming agent contained in the phenol resin foam, for example, a predetermined amount of pulverized phenol resin foam is immersed in a solvent, the defoaming agent is extracted into the solvent, and then a known GC / MS is used. , LC / MS, NMR, ICP spectroscopic analysis and other analytical methods can be applied.
More specifically, for example, 1 g of a phenol resin foam sample is pulverized, and Soxhlet extraction is performed with 150 mL of methanol for about 7 hours. This extract is concentrated to dryness at 40 ° C. using an evaporator, and further vacuum dried at room temperature and 30 ° C., and a solution sample obtained by dissolving the dried sample in 5 mL of methanol is analyzed by the above method. The details of the analysis conditions can be described, for example, in paragraph 0074 of JP-A-2016-101750.

If the defoaming agent is not detected by the above analysis, it can be said that the amount of the defoaming agent contained in the phenol resin foam is below the detection limit. On the other hand, when the phenol resin foam contains, for example, a defoaming agent, the above analysis detects a defoaming agent before decomposition or a component derived from the decomposed defoaming agent.

As described above, regarding the types of defoaming agents contained in the phenolic resin foam, gas chromatograph-mass spectrometer (GC / MS) and liquid chromatograph-mass spectrometer (LC / MS) are used according to the type. In particular, for silicone-based defoamers, whether or not silicone-based defoamers are included by confirming the presence or absence of Si (silicon) by inductively coupled plasma emission spectrometry (ICP emission spectrometry). Whether or not it can be confirmed, and its concentration can be calculated.

When the defoaming agent is a silicone-based defoaming agent, if the concentration of Si (μg / g) in the phenol resin foam plate is 100 μg / g (100 ppm) or more, it is determined that the silicone-based defoaming agent is contained. it can.
The concentration of Si (μg / g) depends on the amount and type of the silicone-based defoaming agent used, but is preferably 100 μg / g or more and 3000 μg / g or less. When the Si concentration is 100 μg / g or more, a sufficient defoaming action can be easily obtained, and excellent heat insulating properties can be easily obtained. When the Si concentration is 3000 μg / g or less, the defoaming action becomes too strong, and the formation of bubble nuclei is inhibited to prevent the formation of fine bubbles, or the density increases and the deterioration of thermal conductivity is suppressed. It's easy to do.

The phenolic resin foam of the present invention preferably contains a surfactant. Surfactants contribute to the miniaturization of bubble diameter (cell diameter). The surfactant is not particularly limited, and known surfactants can be used. For example, castor oil alkylene oxide adduct, silicone-based surfactant, polyoxyethylene sorbitan fatty acid ester and the like can be mentioned. One of these surfactants may be used alone, or two or more thereof may be used in combination.
The defoamer is also a surfactant having a low HLB, and when there are a plurality of surfactants in the system, the HLB of the entire surfactant is a weighted average of each surfactant. Therefore, the HLB as a surfactant is used. It is preferable to use a high one. Therefore, the HLB value of the surfactant is preferably 10 or more and 20 or less, more preferably 13 or more and 19 or less, and most preferably 15 or more and 18 or less. When the HLB value of the surfactant is within the above range, it is easy to obtain a phenol resin foam having less water absorption when the atmospheric humidity rises.

The phenolic resin foam of the present invention preferably contains an acid catalyst. The acid catalyst plays a role in promoting the curing of the phenol 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. One of these acid catalysts may be used alone, or two or more of them may be used in combination.

The phenolic resin foam of the present invention may contain components other than the phenolic resin, foaming agent, surfactant, defoaming agent and acid catalyst.
As other components, known additives for phenol resin foams can be used, for example, urea, plasticizer, filler, flame retardant (for example, phosphorus-based flame retardant), cross-linking agent, organic solvent, amino group. Examples include contained organic compounds and colorants.

The density of the phenolic foam of the present invention, 20 kg / ^{m 3} or more 45 kg / ^{m 3} or less, preferably 23 kg / ^{m 3} or more 40 kg / ^{m 3} or less, more preferably 26 kg / ^{m 3} or more 35 kg / ^{m 3} or less .. When the density of the phenol resin foam is at least the lower limit of the above range, sufficient compressive strength can be obtained. When the density of the phenol resin foam is not more than the upper limit of the above range, excellent heat insulating properties can be obtained.

The average cell diameter (average cell diameter) of the phenolic resin foam of the present invention is 50 μm or more and 200 μm or less, preferably 50 μm or more and 100 μm or less. When the average cell diameter of the phenol resin foam is at least the lower limit of the above range, sufficient compressive strength can be obtained. When the average cell diameter of the phenol resin foam is not more than the upper limit of the above range, 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.
The average cell diameter can be adjusted by the type and composition of the foaming agent, the type of the surfactant, the type of the defoaming agent, the foaming conditions (heating temperature, heating time, etc.) and the like.

A plurality of bubbles are formed in the phenol resin foam of the present invention, there are substantially no pores in the cell wall, and at least a part of the plurality of bubbles is a closed cell that is not communicated with each other. It has become. The gas of the foaming agent is held in the closed cells.
The closed cell ratio of the phenolic resin foam of the present invention is 80% or more, preferably 85% or more, and more preferably 90% or more. When the closed cell ratio of the phenol resin foam is at least the lower limit of the above range, low thermal conductivity can be maintained for a long period of time. The closed cell ratio of the phenol resin foam is substantially 99% or less.
The closed cell ratio of the phenol resin foam is measured according to JIS K 7138: 2006.

The void area ratio of the phenolic resin foam of the present invention is preferably 1% or less, more preferably 0.6% or less, further preferably 0.4% or less, and particularly preferably 0.2% or less. When the void area ratio of the phenol resin foam is not more than the upper limit value, excellent heat insulating properties can be obtained and high compressive strength can be obtained.

The void means a void portion having an area of ^{2 mm 2} or more when the phenol resin foam is cut so that the cross section is flat and the area of the void portion existing in the cross section is measured. To do. The void area ratio of the phenol resin foam is the ratio of the area of voids in the cross section to the cross section of the phenol resin foam.
When the phenol resin foam is a plate-like body, for example, at the central portion in the thickness direction, a cross section parallel to the front and back surfaces (a plane orthogonal to the thickness direction) can be cut out to measure the area of the void portion. ..

The thermal conductivity of the phenolic resin foam of the present invention is preferably less than 0.0190 W / m · K, more preferably 0.0180 W / m · K or less. If the thermal conductivity is less than 0.0190 W / m · K, the heat insulating property is excellent.
The thermal conductivity of the phenolic resin foam can be adjusted by adjusting the average cell diameter, the type and composition of the foaming agent, the type of defoaming agent, the type of surfactant, and the like. The smaller the average cell diameter, the lower the thermal conductivity of the phenolic resin foam tends to be.

The compressive strength of the phenolic resin foam of the present invention ^{is preferably 10 N / cm 2} or more, more preferably 12 N / cm ² or more, and even more preferably 14 N / cm ^{2 or more.} When the compressive strength of the phenol resin foam is at least the lower limit of the above range, it is easy to suppress the occurrence of dents during the construction of the heat insulating material.
The compression strength is measured according to JIS K 7220.
The compressive strength of the phenolic resin foam can be adjusted by the void area ratio, the type and composition of the foaming agent, the type of surfactant, the type of defoamer, the foaming conditions (heating temperature, heating time, etc.) and the like.

The phenolic resin foam of the present invention described above contains a defoaming agent, has a density of 20 kg / m ³ or more and 45 kg / m ³ or less, an average cell diameter of 50 μm or more and 200 μm or less, and a closed cell ratio of 80% or more. The thermal conductivity is controlled to be less than 0.0190 W / m · K, and the void area ratio is controlled to 1% or less. In this way, the voids are reduced and the bubbles are finely controlled, while the density is controlled to be low, so that both excellent heat insulating properties and sufficient compressive strength are achieved.
Moreover, since HFO is used as the foaming agent, the influence on the environment is small.

[Manufacturing method of phenol resin foam]
The method for producing a phenol resin foam of the present invention includes a phenol resin, a foaming agent containing at least one selected from the group consisting of chlorinated hydrofluoroolefins and non-chlorinated hydrofluoroolefins, a surfactant, and defoaming. This is a method of foaming and curing a resin composition containing an agent.
The foam molding may be a continuous type or a batch type, but a continuous type is preferable.

For example, the phenol resin foam is formed by continuously discharging the phenol resin composition from the discharge nozzle onto a face material that continuously travels, introducing the phenol resin composition into a curing furnace heated to 50 to 95 ° C., and foaming and curing the phenol resin composition. Can be manufactured. By using the defoaming agent, the formation of unexpected bubble nuclei before discharge is suppressed, and by appropriately forming the bubble nuclei after discharge, the bubbles become finer and voids are reduced. In addition, by using a double-structured conveyor device in which a slat conveyor is combined inside the belt conveyor as a conveyor for transporting the face material and the discharged resin into the curing furnace, the density is lowered and voids are reduced. At the same time, it can be foamed and cured, so that the thermal conductivity can be lowered. Therefore, a phenol resin foam having excellent heat insulating properties and sufficient compressive strength can be obtained.

Specific examples of the conveyor device include the conveyor device 100 illustrated in FIGS. 1 and 2.
The conveyor device 100 includes a pair of upper belt conveyor 110 and lower belt conveyor 112, and an upper slat conveyor 114 and a lower slat conveyor 116 provided inside the upper belt conveyor 110 and the lower belt conveyor 112, respectively. ing.

The upper belt conveyor 110 includes a flat plate-shaped conveyor belt 118 and drum pulleys 120 and 120 for rotating the hung conveyor belt 118. The lower belt conveyor 112 includes a conveyor belt 122 having a concave section having a rectangular cross section formed on its upper surface, and drum pulleys 124 and 124 for rotating the hung conveyor belt 122. The conveyor belt 118 and the conveyor belt 122 are in contact with each other at their side ends, and a space having a rectangular cross section is formed between them.

The upper slat conveyor 114 has slat 127 attached to the drive chain 126, and is rotated by a pair of sprockets 128 and 128. The upper portion of the drive chain 126 is restricted from traveling in the width direction by the guide rail 129. Similarly, in the lower slat conveyor 116, the slat 131 is attached to the drive chain 130, and the lower slat conveyor 116 is rotated by a pair of sprockets 132 and 132. The upper portion of the drive chain 130 is restricted from traveling in the width direction by the guide rail 133.

In the conveyor device 100, the upper slat conveyor 114 is arranged in the upper belt conveyor 110 so that the upper surface and the lower surface thereof are in contact with the inner surface of the conveyor belt 118. Similarly, the lower slat conveyor 116 is arranged in the lower belt conveyor 112 so that its upper surface and lower surface are in contact with the inner surface of the conveyor belt 122. As described above, in the conveyor device 100, the upper belt conveyor 110 and the upper slat conveyor 114, and the lower belt conveyor 112 and the lower slat conveyor 116 each have a double structure.

When the conveyor device 100 is used, for example, a pair of strip-shaped face materials 10 and 12 are supplied between the conveyor belt 118 of the upper belt conveyor 110 and the conveyor belt 122 of the lower belt conveyor 112 to continuously travel the lower side. The phenol resin composition X is continuously discharged from the discharge nozzle 200 onto the face material 12 and introduced into the heating furnace to be foam-cured.

Curing proceeds by the acid catalyst in the phenol resin composition after being discharged from the discharge nozzle, but when the resin being cured flows for some reason, the stress caused by the flow is applied to the bubbles and the bubble wall is broken. When the above-mentioned conveyor device is not used, the conveyor belt cannot withstand the foaming pressure (force to expand) of the resin itself during foaming and floats unevenly, and during curing, the resin floats toward the lifted portion. Easy to flow. Therefore, the bubble wall is easily broken during curing, and the density of the phenol resin foam increases.
On the other hand, in the conveyor device 100, the lifting of the conveyor belt 118 of the upper belt conveyor 110 and the conveyor belt 122 of the lower belt conveyor 112 due to the foaming pressure is suppressed by the upper slat conveyor 114 and the lower slat conveyor 116. In this way, since the meandering of the conveyor belts 118 and 122 is suppressed, the resin does not easily flow during curing, foam rupture is suppressed, and a low-density phenol resin foam can be obtained.

Further, in a non-breathable conveyor belt, there is no escape for moisture and foaming agent, and voids are likely to occur. In particular, if the temperature inside the furnace is raised in order to reduce the density, problems are likely to occur due to the lack of escape for moisture and foaming agent. Therefore, as the conveyor belt, a breathable metal wire conveyor belt or a perforated belt is adopted, and a slat conveyor is provided in the belt conveyor.

Metal wire belts include a mesh-like metal mesh belt (Kansai wire mesh company "rope woven wire mesh") woven with fine metal wires, and a wire conveyor belt woven with spiral wires and straight wires (Kansai). "Wire conveyor belt" manufactured by Wire Mesh Co., Ltd.). These metal wire conveyor belts are breathable due to the gaps between the wires, but if the gaps between the wires are too large, the surface of the foam may become uneven or the face material may get caught and spoil the appearance. The higher the weight), the better. Further, those having chains attached to both sides of these metal wire conveyor belts may be used.
As the perforated belt, a belt having an aperture ratio set to 15% or more and 80% or less is used, and the shape of the holes can be a circular diameter, a quadrangle, a hexagon, a rectangle, or the like. The aperture ratio is preferably 30% or more from the viewpoint of residual water content. The upper limit of the aperture ratio is preferably 70% or less, more preferably 65% or less, from the viewpoint of conveyor durability.
As described above, by ensuring the air permeability while suppressing the meandering of the conveyor belt, it is possible to reduce the voids while reducing the density of the phenol resin foam.

In the present invention, a face material may be provided when foam molding is performed to produce a phenol resin foam. The face material may be provided on one side of the phenol resin foam or on both sides.
As a method of providing the face material when producing the phenol resin foam, for example, the face material is arranged on a conveyor belt that runs continuously, the phenol resin composition is discharged from the discharge nozzle on the face material, and the phenol resin composition is discharged onto the face material. After laminating other face materials on the surface, a method of foam molding by passing through a heating furnace can be mentioned. As a result, a phenol resin foam with a face material in which face materials are laminated on both sides of the plate-shaped phenol resin foam can be obtained.
Further, after the continuous foam molding or the batch foam molding as described above, the face material may be attached to the phenol resin foam using an adhesive.

The face material is not particularly limited, and is a synthetic fiber non-woven fabric made of glass paper, glass fiber woven fabric, glass fiber non-woven fabric, glass fiber mixed paper, kraft paper, polyester, polypropylene, nylon, etc., spunbonded non-woven fabric, aluminum foil-covered non-woven fabric. , Aluminum foil-clad kraft paper, metal plate, metal foil, plywood, calcium silicate plate, gypsum board and at least one selected from wood-based cement plate are suitable. When the face materials are provided on both sides of the phenol resin foam, the face materials may be the same or different.

The order and method of mixing the phenol resin, the foaming agent, the surfactant, the defoaming agent, and other components used as necessary are not particularly limited. In the case of continuous foam molding, the defoaming agent may be added at least to the discharge nozzle from which the phenol resin composition is discharged, and preferably to the tournament distribution pipe to be distributed to each discharge port.

The defoaming agent may be added at the time of synthesizing the phenol resin that polymerizes phenol and formalin. As a result, bubbles generated by heat and stirring during dehydration and concentration of the phenol resin can be suppressed. Further, a defoaming agent may be added after the dehydration condensation of the phenol resin, so that the bubbles generated can be defoamed, and the surfactant added after that can be captured at the gas-liquid interface of the generated bubbles. Can be suppressed. Further, by adding the foaming agent and the curing agent (acid catalyst) together in the mixing mixer, it is possible to suppress the entrainment of air in the mixing by the mixer and the bubbles generated by the heat of reaction.
When adding a defoaming agent to a phenol resin, a phenol resin in which the defoaming agent is added in advance and then kneaded well to uniformly disperse the defoaming agent is prepared as a master batch, and this master batch is foamed. It is preferable to add it to the phenol resin together with the agent and the like. This makes it easier to uniformly disperse the antifoaming agent having a low HLB, that is, having a high hydrophobicity, in the phenol resin having a high hydrophilicity.
As described above, the defoaming agent can suppress the unexpected generation of bubble nuclei in the phenol resin composition before ejection from the ejection nozzle, control the bubble diameter to be small, and the bubbles grow into voids. Can be suppressed.

The content of the foaming agent in the 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 5 parts by mass or more and 11 parts by mass with respect to 100 parts by mass of the phenol resin. It is more preferably parts by mass or less.

The content of the chlorinated HFO or the non-chlorinated HFO in the phenol resin composition is preferably 30% by mass or more, more preferably 50% by mass or more, and most preferably 70% by mass or more with respect to the total mass of the foaming agent. ..
When the foaming agent is a mixture of two or more kinds, the composition (mass ratio) of the foaming agent contained in the bubbles of the phenol resin foam after foam curing is the composition (mass ratio) of the foaming agent contained in the phenol resin composition before foam curing. It is almost consistent with the composition.

The content of the defoaming agent in the phenol resin composition is preferably 0.05 parts by mass or more and 2 parts by mass or less, and more preferably 0.1 parts by mass or more and 1 part by mass or less with respect to 100 parts by mass of the phenol resin. More preferably, it is 0.1 part by mass or more and 0.5 part by mass or less. When the content of the defoaming agent is at least the lower limit of the above range, the generation of voids is suppressed, and a phenol resin foam having excellent heat insulating properties and compressive strength can be obtained. When the content of the defoaming agent is not more than the upper limit of the above range, it is easy to prevent the density of the phenol resin foam from becoming too high and the heat insulating property from being lowered.

When a surfactant is used, the content of the surfactant in the phenol resin composition is preferably 1 part by mass or more and 10 parts by mass or less, and 2 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the phenol resin. Is more preferable. When the content of the surfactant is at least the lower limit of the above range, the bubble diameter tends to be uniformly reduced. When the content of the surfactant is not more than the upper limit of the above range, a phenol resin foam having less water absorption can be easily obtained, and the production cost can be suppressed.

When an acid catalyst is used, the content of the acid catalyst in the phenol resin composition is preferably 5 parts by mass or more and 30 parts by mass or less, and more preferably 8 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the phenol resin. It is preferable, and more preferably 10 parts by mass or more and 20 parts by mass or less.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the following description.
[Measuring method]
The method for measuring the physical properties of the phenol resin foam plate is as follows.
(density)
The density of the phenolic resin foam plate was measured according to JIS A 9511: 2009.

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

(Closed cell ratio)
The closed cell ratio of the phenol resin foam plate was measured according to JIS K7138-2006.

(Measurement of Si concentration derived from defoamer in phenol resin foam by ICP emission spectroscopic analysis)
As an analysis of the silicone-based defoaming agent, the Si concentration of the phenol resin foam plate was measured.
A sample of about 0.02 to 0.05 g was cut out from the central portion in the thickness direction of the phenolic resin foam plate, collected in a platinum crucible, and the mass of the sample was precisely weighed. Next, 0.5 g ± 0.1 g of sodium carbonate was added to the platinum crucible containing the sample, and the sample was thawed by the following incineration / melting procedure. After cooling the melt, the melt in the platinum crucible was dissolved in pure water and transferred to a 50 mL volumetric flask, and the volume was adjusted to 50 mL using pure water to prepare a sample solution. ICP measurement was performed using the obtained sample solution under the conditions described below, and the Si content in the sample solution was calculated from the calibration curve. Then, the concentration of Si (μg / g) in the phenol resin foam plate was calculated from the following formula. The calibration curve will be described later.
Q (μg / mL) = Q1 (μg / mL) x 50 (mL) / W (g)
However, in the above formula, Q is the concentration of Si in the phenol formaldehyde foam plate (μg / g), Q1 is the concentration of Si in the sample solution (μg / mL), and W is the mass of the precisely weighed sample. (G).

<Procedure for incineration / melting>
The platinum crucible containing the sample was heated in a muffle furnace set at 350 ° C. for about 15 minutes and dried. Next, the muffle furnace was heated to 650 ° C. and heated for about 3 hours, and further heated to 800 ° C. and heated for about 1 hour to incinerate the sample. Next, the muffle furnace was heated to 910 ° C. and heated for about 1 hour to melt the sample and sodium carbonate.

<ICP measurement conditions>
Measuring device: SII Nanotechnology SPS5100,
Measuring element: Si (wavelength: 288.158 nm),
High frequency output: 1.2kW,
Carrier gas flow rate: 0.9 L / min,
Plasma flow rate: 15 L / min,
Auxiliary flow rate: 1.5 L / min.

<How to create a calibration curve>
Dilute the blank (0 ppm) containing only pure water and the standard solution for calibration curve (product name: silica standard solution manufactured by Wako Pure Chemical Industries, Ltd.) as a standard sample to 0.5 ppm, 2 ppm, 20 ppm, and 50 ppm. The wavelength peak intensity of Si was obtained for each of the prepared diluted samples. The concentration and peak intensity of the blank and diluted samples were plotted to obtain an approximate curve (straight line or quadratic curve) by the least squares method, and this was used as a calibration curve for quantification.

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

(Void area ratio)
Approximately the center in the thickness direction of the phenol resin foam plate was cut parallel to the front and back surfaces, and a photograph or a color copy obtained by enlarging the range of 100 mm × 150 mm in the cross section to 200% was obtained. In a photograph or a copy drawing, the length of each of the vertical and horizontal directions is twice the actual size, and the area is four times the actual area. A transparent graph paper is overlaid on the photograph or copy drawing from above, large-diameter bubbles are selected, the cross-sectional area of the cells is measured using the grids of the graph paper, and 1 mm × 1 mm cells are continuous over 8 cells or more. The existing hole was judged to be a void. The area of the voids observed in the photograph or the copy drawing was integrated, and the area fraction (void area ratio) was calculated from the integrated area of the voids. Since the image is magnified to 200%, 8 squares correspond to an area of ^{2 mm 2 in the actual foam cross section.} The measurement was performed 12 times, and the average value thereof was taken as the void area ratio.

(Compression strength)
The compressive strength was measured according to JIS K 7220.

[Example 1]
The chlorinated HFO 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) and cyclopentane were mixed at a mass ratio of 8: 2 to prepare a foaming agent (A).
Liquid silicone-based defoamer (“ES-5600” manufactured by Toray Dow Corning Co., Ltd., HLB = 2) in 100 parts by mass of liquid resol type phenol resin (manufactured by Asahi Organic Materials Industry Co., Ltd., trade name: PF-339) 0. 5 parts by mass, 4 parts by mass of castor oil EO adduct (“SURFRIC CO-40” manufactured by Ito Oil Co., Ltd., EO addition mole number: 40, HLB = 13) as a surfactant, and 4 parts by mass of urea as a formaldehyde catcher Was mixed and left at 20 ° C. for 8 hours. To 108 parts by mass of the obtained mixture, 18 parts by mass of the foaming agent (A) was added, 16 parts by mass of a mixture of p-toluenesulfonic acid and xylenesulfonic acid was added as an acid catalyst, and the mixture was stirred and mixed to form a phenol resin composition. Was prepared.
The first face material (material: glass fiber mixed paper) is continuously run in one direction, and the phenol resin composition is placed on the first face material from 16 nozzles arranged at equal intervals in the TD direction. It was discharged, and a second face material (material: glass fiber mixed paper) was placed on it and heated at 70 ° C. for 300 seconds to foam and cure. After the foam curing step, it was dried at 80 ° C. for 5 hours to obtain a phenol resin foam.
At this time, the conveyor device 100 illustrated in FIGS. 1 and 2 was used as the conveyor device for continuous heating, foaming, and curing.
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.

[Examples 2 to 8]
A phenol resin foam was produced in the same manner as in Example 1 except that the defoaming agent was changed as shown in Table 1, and a phenol resin foam plate was produced.

[Examples 9 to 13]
A phenol resin foam was produced in the same manner as in Example 1 except that the composition of the foaming agent was changed as shown in Table 1, and a phenol resin foam plate was produced.

[Comparative Example 1]
A phenol resin foam was produced in the same manner as in Example 1 except that an antifoaming agent was not used, to produce a phenol resin foam plate.

[Comparative Examples 2 and 3]
A phenol resin foam was produced in the same manner as in Example 1 except that the amount of the antifoaming agent was changed as shown in Table 1, to produce a phenol resin foam plate.

Table 1 shows the results of measuring the density, average cell diameter, closed cell ratio, thermal conductivity, and void area ratio of the phenol resin foam plates obtained in each example. The abbreviations in Table 1 have the following meanings.
HCFO-1233zd: (E) -1-chloro-3,3,3-trifluoropropene,
CP: Cyclopentane,
IPC: Isopropyl chloride (2-chloropropane),
LSA1: Liquid silicone antifoaming agent ("ES-5600" manufactured by Toray Dow Corning, HLB = 2),
LSA2: Liquid silicone antifoaming agent ("ES-5612" manufactured by Toray Dow Corning, HLB = 4),
LSA3: Liquid silicone defoamer ("KF-6012" manufactured by Shinetsu Silicone Co., Ltd., HLB = 7),
LSA4: Liquid silicone antifoaming agent ("KF-6004" manufactured by Shinetsu Silicone Co., Ltd., HLB = 9),
ETA1: Ether-based defoamer ("Nonipol 20" manufactured by Sanyo Chemical Industries, Ltd., HLB = 6),
ALA1: Alcohol-based defoamer ("Oleyl alcohol VP" manufactured by Higher Alcohol Industry Co., Ltd., HLB = 7).

As shown in Table 1, Examples 1 to 13 include a phenol resin, a foaming agent, and a defoaming agent, and the density, average cell diameter, closed cell ratio, and void area ratio satisfy the conditions specified in the present invention. The phenol resin foam had low thermal conductivity, excellent heat insulating properties, and high compressive strength.
On the other hand, in Comparative Examples 1 and 2 in which the defoaming agent was not contained or the amount used was small and the void area ratio was more than 1%, the compressive strength was insufficient. Many amount of the antifoaming agent, density at 45 kg / m ³ greater than Comparative Example 3 was inferior in heat insulating property.

Claims (3)

Phenol formaldehyde, foaming agent containing (E) -1-chloro-3,3,3-trifluoropropene , silicone defoamer with HLB of 2 or more and 9 or less, and surfactant with HLB of 10 or more and 20 or less. A phenolic resin foam containing an agent (excluding silicone-based surfactant).
Contains 30% by mass or more of (E) -1-chloro-3,3,3-trifluoropropene with respect to 100% by mass of the foaming agent.
The density is 23 kg / m ³ or more and 40 kg / m ³ or less .
The average cell diameter is 50 μm or more and 100 μm or less .
The closed cell ratio is 80% or more,
The void area ratio is 0.6% or less,
Thermal conductivity is less than 0.0190 W / m · K,
The concentration of Si in the phenol resin foam is 100 μg / g or more and 3000 μg / g or less.
A phenolic resin foam having a compressive strength of 14 N / cm ² or more. The phenolic resin foam according to claim 1 , wherein the defoaming agent is a silicone-based defoaming agent. The method for producing a phenol resin foam according to claim 1 or 2.
Said phenolic resin, said a foaming agent, wherein the antifoaming agent, the phenolic resin composition comprising a surfactant to foam, cure, method for producing phenolic foam.

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