WO2023204283A1

WO2023204283A1 - Foamed phenolic-resin object and laminate thereof

Info

Publication number: WO2023204283A1
Application number: PCT/JP2023/015835
Authority: WO
Inventors: 成実宮田; 英徹栗田
Original assignee: 旭化成建材株式会社
Priority date: 2022-04-22
Filing date: 2023-04-20
Publication date: 2023-10-26
Also published as: JPWO2023204283A1; TW202344587A

Abstract

A foamed phenolic-resin object containing a hydrofluoroether represented by (formula 1) in an amount of 0.03-4.3 mass%. (Formula 1): C_aH_bF_c-O-C_xH_yF_z (where a, b, c, x, y, and z are integers, and 2≤a≤7, 0≤b≤3, c=2a+1-b, b≤2a+1, 1≤x≤3, 2≤y≤7, z=2×x+1-y, and y≤2x+1)

Description

Phenolic resin foam and its laminates

Cross-reference of related applications

This application claims priority to Japanese Patent Application No. 2022-071172 filed in Japan on April 22, 2022, and the entire disclosure of this earlier application is incorporated herein by reference.

The present invention relates to a phenolic resin foam and a laminate thereof.

Unlike the fiber-based glass wool and rock wool, foamed plastic insulation materials contain gas with low thermal conductivity within the bubbles, and exhibit even higher insulation performance, making them ideal for exterior wall materials such as metal siding, and partition panels. It is widely used in building materials such as ceiling materials, fire doors, and storm shutters, as well as wall materials without .

In recent years, there has been an urgent need to reduce greenhouse gases due to concerns about global warming, and highly insulated buildings are attracting attention as a means of reducing greenhouse gases through energy conservation. Since the higher the insulation performance, the greater the energy saving effect, there has been a demand for further improvements in insulation performance.

Phenol resin foam is a typical example of a foam with high heat insulation performance. In order to improve the heat insulation performance, attempts have been made to reduce the cell diameter of foams in addition to using gases with low thermal conductivity.

Patent Document 1 discloses that a phenolic resin foam with high heat insulation performance can be obtained by adding fluoroether, which has the effect of reducing the cell diameter, and reducing the cell diameter of the phenolic resin foam. Further, Patent Document 2 discloses that by adding a powdery solidified phenol resin, the cell diameter of a phenol resin foam can be reduced and high heat insulation can be achieved.

Japanese Patent Application Publication No. 11-140217 JP2017-210618A

However, Galden, which is listed as an example of fluoroether in Patent Document 1, is expensive, and has a high global warming potential (GWP) and relatively large environmental impact, so it is difficult to actively use it. In addition, the effect of reducing the cell diameter is limited only when the blowing agent is a hydrocarbon, and no adaptation has been made to the case where a hydrofluoroolefin with low thermal conductivity is used as the blowing agent.

On the other hand, although Patent Document 2 is a technology that reduces the bubble diameter even when hydrofluoroolefins are used as a blowing agent, the thermal conductivity of the solid increases as more powdered phenol resin solidified material is added. It is hard to say that this is a preferable method for lowering the . Moreover, if the powdery phenol resin solidified product is added in a large amount, it tends to stay in the pipes, which may clog the pipes and reduce productivity. Furthermore, the powdered solidified phenol resin requires equipment for kneading the powder into resin in addition to equipment for producing the powder, which requires a large investment in equipment.

Therefore, the present inventors believe that there are three main ways to improve the heat insulation performance of resin foam, that is, to reduce the thermal conductivity. The first is to ``use a gas with low thermal conductivity,'' the second is to ``reduce the cell diameter of the foam,'' and the third is to ``reduce the density of the foam.'' It is. Regarding the third option, "lowering the density," it is not a practical solution because lowering the density makes it impossible to maintain the closed cell ratio of the resin foam, and furthermore, it has negative effects such as a decline in mechanical properties. I don't get it. Furthermore, due to the large contribution effect to thermal conductivity, the first method is generally being actively investigated.

Based on the first viewpoint, CFCs and HFCs with low thermal conductivity were widely used in the past. However, their use is regulated due to their high ozone depletion potential (ODP), and currently, hydrofluoroolefins, which have similar excellent thermal conductivity, ODP of 0, and low GWP, are the mainstream. There is. However, there is a limit to improving thermal conductivity if only the first point of view is addressed, and in order to further improve thermal conductivity, the second point of view is "reducing the cell diameter of the foam". It is necessary to master.

This second perspective is specifically based on the following ideas. That is, first of all, it is important to create as many cell nuclei as possible in the resin composition. Secondly, it is important to allow the generated bubbles to grow stably while not causing them to burst, and by achieving both of these, it is possible to realize the miniaturization of the bubbles. The finer the bubble diameter is, the more it is possible to suppress the radiant heat conduction of the foam. Therefore, making the bubble diameter smaller is the second most important factor for thermal conductivity after using a gas with low thermal conductivity. This can be said to be a major contributing factor.

Therefore, there has been a need for a technique for reducing the cell diameter when using various blowing agents, which is essential for lowering the thermal conductivity of phenolic resin foams.

The present inventors have conducted extensive studies to solve the above problems, and have found that by adding a specific hydrofluoroether to a phenolic resin composition, the cell diameter of the phenolic resin foam can be made finer. We have developed a technology that can reduce thermal conductivity when using blowing agents. That is, the present invention is as follows.

[1]
A phenolic resin foam containing 0.03 to 4.3% by mass of a hydrofluoroether represented by the following (Formula 1) based on the phenolic resin foam.
Formula 1: C _a H _b F _c -O-C _x H _y F _z
(However, a, b, c, x, y, z are integers, 2≦a≦7, 0≦b≦3, c=2a+1-b, b≦2a+1, 1≦x≦3, 2≦y ≦7, z=2×x+1-y, y≦2x+1)
[2]
The hydrofluoroether represented by (Formula 1) is methyl perfluoropropyl ether, methyl nonafluorobutyl ether, methyl nonafluoroisobutyl ether, ethyl nonafluorobutyl ether, ethyl nonafluoroisobutyl ether, 1,1,1,2,2 , 3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)-pentane, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether The phenolic resin foam according to [1], which is any one of the above.
[3]
The phenolic resin foam according to [1] or [2], having an average cell diameter of 70 μm or more and 180 μm or less.
[4]
The phenolic resin foam according to any one of [1] to [3], wherein the blowing agent contains a hydrofluoroolefin.
[5]
The phenolic resin foam according to [4], wherein the blowing agent contains a hydrocarbon.
[6]
The phenolic resin foam according to any one of [1] to [5], which has a density of 10 kg/m ³ or more and 70 kg/m ³ or less.
[7]
The phenolic resin foam according to any one of [1] to [6], which has a closed cell ratio of 80% or more.
[8]
The phenolic resin foam laminate according to any one of [1] to [7], comprising a surface material on at least one of one side of the phenolic resin foam and the back side of the one side.

The phenolic resin foam and its laminate according to the present invention can make the cell diameter of the phenolic resin foam finer. Since cell size contributes to reducing thermal conductivity, the use of each blowing agent can reduce thermal conductivity. In addition, this is an improvement especially in cases where there are appearance defects such as voids or uneven color of the foam, or low compressive strength when no hydrofluoroether is added. Furthermore, since the GWP of the raw material is small, it is possible to provide an environmentally friendly foam with a small environmental impact.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as "this embodiment") will be described in detail. Note that the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist. In addition, in this specification, a product obtained by adding a surfactant to a "phenol resin" is referred to as a "phenol resin composition", and a "phenol resin composition" includes a hydrofluoroether, a foaming agent, a foaming nucleating agent, and the like. A composition to which an acidic curing agent or the like is added to impart foamability or both foamability and curability is referred to as a "foamable phenol resin composition." Moreover, the obtained foam is referred to as a "phenol resin foam."

<Phenol resin foam>
The phenolic resin foam of this embodiment is manufactured from a phenolic resin composition containing a hydrofluoroether, a blowing agent, and an acidic curing agent.

The hydrofluoroether contained in the phenolic resin foam of this embodiment is represented by (Formula 2).
Formula 2: C _a H _b F _c -O-C _x H _y F _z
(However, a, b, c, x, y, z are integers, 2≦a≦7, 0≦b≦3, c=2a+1-b, b≦2a+1, 1≦x≦3, 2≦y ≦7, z=2×x+1-y, y≦2x+1)

By adding this hydrofluoroether to a phenol resin or a phenol resin composition, the effect of reducing the cell diameter of the phenol resin foam can be obtained. Generally, the content is 0.03% to 4.3% by mass, preferably 0.1% to 3.8% by mass, more preferably 0.3% by mass based on the phenolic resin foam. 3.3% by weight, most preferably 0.5% to 3.3% by weight. This hydrofluoroether may be a combination of two or more types of molecules corresponding to Formula 2. When the content of hydrofluoroether is 0.03% by mass or more, the thermal conductivity tends to be low. Furthermore, if the content of hydrofluoroether is 4.3% by mass or less, even if a hydrofluoroether with a high boiling point is used, the thermal conductivity will decrease due to an increase in the amount of hydrofluoroether that liquefies in the foam. There is little concern that the size will increase or the rigidity of the phenol resin will decrease. In this embodiment, in order to keep the content of hydrofluoroether in the phenolic resin foam within the above range (0.03% to 4.3% by mass), the type of hydrofluoroether and the phase with the phenolic resin are adjusted. Although it varies depending on foaming and curing conditions such as solubility, foaming temperature and residence time during foam production, the amount of hydrofluoroether added to 100 parts by mass of the phenolic resin composition is 0.1 parts by mass to 6.8 parts by mass. It is preferable that there be.

Hydrofluoroether is thought to form bubble nuclei by itself in the phenolic resin, and as it increases the number of bubbles in the foamable phenolic resin composition, it reduces the average cell diameter of the phenolic resin foam and suppresses radiant heat conduction. , is thought to have the effect of lowering the thermal conductivity of the phenolic resin foam. The order in which the phenolic resin composition, blowing agent, and hydrofluoroether are mixed is not particularly limited, but the hydrofluoroether may be kneaded with the phenol resin composition before the blowing agent is kneaded, or the hydrofluoroether may be mixed with the hydrofluoroether. It is more preferable to simultaneously knead the agent into the phenolic resin composition. When the hydrofluoroether is kneaded into the phenolic resin composition after the blowing agent, or when a premixed mixture of the hydrofluoroether and the blowing agent is kneaded into the phenolic resin composition, the hydrofluoroether self-builds bubbles. However, there is a risk that it will adsorb to the bubbles that are already in the growth process and inhibit the growth of the bubbles. There is a concern that this may reduce the closed cell ratio. The kneading method is not particularly limited as long as the hydrofluoroether can be uniformly dispersed in the phenol resin or phenol resin composition. In addition, hydrofluoroether has an oxygen atom and an alkyl group in its molecule, so it has a shorter atmospheric lifetime than perfluoroalkanes, so it has the advantage of having a relatively small global warming potential and a small environmental burden. Furthermore, since the presence of oxygen atoms in the molecule increases compatibility with phenolic resin, it is thought that the dispersibility of hydrofluoroether in phenolic resin increases and has the effect of promoting the formation of fine bubble nuclei. It will be done. On the other hand, molecular chains consisting only of carbon and fluorine in hydrofluoroethers tend to have longer atmospheric lifetimes and have a higher GWP. is preferably not long. Moreover, since hydrofluoroether is a flame-retardant substance, it is thought that the higher the content in the phenol resin foam, the more difficult the phenol resin foam becomes to burn.

The hydrofluoroether of (Formula 2) needs to be an ether of a group represented by C _a H _b F _c and a group represented by C _x H _y F _z . The number of carbon atoms, ie, the value of a, in the group represented by C _a H _b F _c must be 2 to 7, preferably 2 to 6, from the viewpoint of the boiling point of the hydrofluoroether. The group represented by C _a H _b F _c is a hydrocarbon group in which some or all of the hydrogens are substituted with fluorine, and preferably has a small number of hydrogen atoms, and the value of b is 0 to 3. 0 or 1 is preferred, and 0 is particularly preferred. The number of carbon atoms, ie, the value of x, in the group represented by C _x H _y F _z must be from 1 to 3, preferably from 1 to 2, from the viewpoint of the boiling point of the hydrofluoroether. The group represented by C _x H _y F _z is a hydrocarbon group or a group in which part of the hydrocarbon is substituted with fluorine, preferably one with a small number of fluorine atoms, and the value of z is 0 to 3. is preferred. When the value of hydrofluoroether a is 7 or less and the value of x is 3 or less, the boiling point is sufficiently low and the proportion of hydrofluoroether remaining as droplets in the foam tends to be small, so the droplets generate heat. Increase in conduction can be suppressed. The hydrofluoroether of (Formula 2) has a group represented by C _a H _b F _c with a small number of hydrogen atoms and a C _x H _y F _z group with a small number of fluorine atoms, so that it can be easily absorbed in the resin. It is thought that this increases the dispersibility of hydrofluoroether and promotes the formation of fine bubble nuclei. Furthermore, it is preferable that a≧x, and more preferably that a>x.

Hydrofluoroethers of formula 2 preferably used in the present invention include methyl perfluoropropyl ether, methyl nonafluorobutyl ether, methyl nonafluoroisobutyl ether, ethyl nonafluorobutyl ether, ethyl nonafluoroisobutyl ether, 1,1,1 , 2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)-pentane, 1,1,2,2-tetrafluoroethyl-2,2,2- Trifluoroethyl ether is mentioned. These hydrofluoroethers may be used alone or in combination of two or more.

The phenolic resin foam according to the present invention tends to have improved compressive strength compared to the phenolic resin foam to which no hydrofluoroether is added. This is because the addition of hydrofluoroether reduces the cell diameter, which increases the number of cell walls lined up in the compression direction compared to a phenolic resin foam that does not contain hydrofluoroether, which increases the opposing force. This is due to the reduction of voids that serve as starting points for

Furthermore, in this embodiment, the appearance is improved compared to a phenolic resin foam to which no hydrofluoroether is added. This is because adding hydrofluoroether not only reduces the cell diameter, but also reduces the incidence of voids and tends to make the cell diameter uniform in the thickness direction, eliminating uneven color of the foam. It's for a reason.

The average cell diameter of the phenolic resin foam in the present invention is preferably 70 μm or more and 180 μm or less, more preferably 70 μm or more and 170 μm or less, even more preferably 70 μm or more and 150 μm or less, and most preferably 70 μm or more and 135 μm or less. When the average cell diameter is 70 μm or more, it is possible to suppress an increase in thermal conductivity due to heat conduction of the phenol resin portion, which increases as the cell diameter becomes smaller. Conversely, when the bubble diameter is 180 μm or less, heat conduction by radiation is small, and an increase in thermal conductivity can be suppressed. Note that the average cell diameter of the phenolic resin foam is determined by, for example, the amount of hydrofluoroether added, the amount of solid foam nucleating agent added, the temperature of the foamable phenolic resin composition, and the amount of the mixed foamable phenolic resin composition added to the lower surface material. The desired value can be adjusted by changing the timing of preforming in the upward discharge step, the amount of foaming agent added, the amount of acidic curing agent added, and curing conditions such as temperature and residence time.

The phenolic resin foam of the present invention can use hydrofluoroolefins, hydrocarbons, and chlorinated hydrocarbons as blowing agents singly or in combination of two or more of these.

Hydrofluoroolefins generally have low thermal conductivity, and when used as a blowing agent, are preferred because they yield phenolic resin foams with low thermal conductivity. Hydrofluoroolefins include chlorinated hydrofluoroolefins and non-chlorinated hydrofluoroolefins. In the present invention, chlorinated hydrofluoroolefins and non-chlorinated hydrofluoroolefins can also be used in combination.

Examples of chlorinated hydrofluoroolefins include (Z)-1-Chloro-2,3,3,3-Tetrafluoropropene (HCFO-1224yd(Z)), 1-chloro-3,3,3-trifluoropropene (HCFO- 1233zd, for example, E form (HCFO-1233zd(E)), manufactured by Honeywell Japan Co., Ltd., product name: Solstice (trademark) LBA), 1,1,2-trichloro-3,3,3-trifluoropropene (HCFO-1213xa), 1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd), 1,1-dichloro-3,3,3-trifluoropropene (HCFO-1223za), 1- Chloro-1,3,3,3-tetrafluoropropene (HCFO-1224zb), 2,3,3-trichloro-3-fluoropropene (HCFO-1231xf), 2,3-dichloro-3,3-difluoropropene ( HCFO-1232xf), 2-chloro-1,1,3-trifluoropropene (HCFO-1233xc), 2-chloro-1,3,3-trifluoropropene (HCFO-1233xe), 2-chloro-3,3 , 3-trifluoropropene (HCFO-1233xf), 1-chloro-1,2,3-trifluoropropene (HCFO-1233yb), 3-chloro-1,1,3-trifluoropropene (HCFO-1233yc), 1-chloro-2,3,3-trifluoropropene (HCFO-1233yd), 3-chloro-1,2,3-trifluoropropene (HCFO-1233ye), 3-chloro-2,3,3-trifluoro Propene (HCFO-1233yf), 1-chloro-1,3,3-trifluoropropene (HCFO-1233zb), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), etc. One or a mixture of the configurational isomers, ie, the E-form or the Z-form, is used. Furthermore, (E)-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd(E)) can also be mentioned. In the present invention, two or more of these chlorinated hydrofluoroolefins may be used in combination.

Non-chlorinated hydrofluoroolefins include 1,3,3,3-tetrafluoroprop-1-ene (HFO-1234ze, for example, E form (HFO-1234ze (E)), manufactured by Honeywell Japan Co., Ltd.; Product name: Solstice (trademark) ze), 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz, e.g. Z-form (HFO-1336mzz (Z)), Chemours Stock Opteon (trademark) 1100), 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf), 1,1,3,3,3-pentafluoropropene (HFO-1225zc), 1 , 3,3,3-tetrafluoropropene (HFO-1234ze), 3,3,3-trifluoropropene (HFO-1243zf), 1,1,1,4,4,5,5,5-octafluoro- Examples include 2-pentene (HFO-1438mzz), and one or a mixture of these configurational isomers, ie, E form or Z form, is used. In the present invention, two or more of these non-chlorinated hydrofluoroolefins may be used in combination.

As the hydrocarbon, cyclic or chain alkanes, alkenes, and alkynes having 3 to 7 carbon atoms are preferable, and specifically, normal butane, isobutane, cyclobutane, normal pentane, isopentane, cyclopentane, neopentane, normal hexane, Examples include isohexane, 2,2-dimethylbutane, 2,3-dimethylbutane, cyclohexane, and the like. Among these, pentanes such as normal pentane, isopentane, cyclopentane, and neopentane, and butanes such as normal butane, isobutane, and cyclobutane are preferably used. In the present invention, two or more of these hydrocarbons may be used in combination. Examples of mixtures include normal pentane and normal butane, isobutane and isopentane, normal butane and isopentane, isobutane and normal pentane, cyclopentane and normal butane, cyclopentane and isobutane, and the like.

As the chlorinated hydrocarbon, linear or branched chlorinated aliphatic hydrocarbons having 2 to 5 carbon atoms can be preferably used. The number of bonded chlorine atoms is preferably 1 to 4, and examples thereof include dichloroethane, propyl chloride, 2-chloropropane, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride. Among these, propyl chloride and 2-chloropropane, which are chloropropanes, are more preferably used. In the present invention, two or more of these chlorinated hydrocarbons may be used in combination.

Further, other blowing agents are not particularly limited, and include, for example, sodium hydrogen carbonate, sodium carbonate, calcium carbonate, magnesium carbonate, azodicarboxylic acid amide, azobisisobutyronitrile, barium azodicarboxylate, N,N' -Chemical blowing agents such as dinitrosopentamethylenetetramine, p,p'-oxybisbenzenesulfonylhydrazide, and trihydrazinotriazine, and the like. These blowing agents may be used alone or in combination of two or more.

The amount of blowing agent in the phenolic resin composition varies depending on the type of blowing agent, the compatibility of the blowing agent with the phenolic resin, temperature, and conditions for foaming and curing such as residence time. Therefore, it may be determined arbitrarily depending on the density of the desired phenolic resin foam, foaming conditions, etc., but it is preferably 3.0 to 20 parts by mass, more preferably 4 parts by mass, based on 100 parts by mass of the phenolic resin composition. 0 to 18 parts by weight, more preferably 5.0 to 16 parts by weight, and most preferably 6.0 to 15 parts by weight. When the amount of the blowing agent per 100 parts by mass of the phenol resin composition is 3.0 parts by mass or more, high density of the resin foam can be suppressed. In addition, if the amount of the blowing agent per 100 parts by mass of the phenolic resin composition is 20 parts by mass or less, the phenol resin foam will have a low density, resulting in a decrease in mechanical strength such as compressive strength and damage to the cell walls. It becomes easier to suppress the decrease in the closed cell ratio due to the increase in the thermal conductivity, and it is possible to suppress the increase in thermal conductivity.

In this embodiment, a foam nucleating agent may be used in the production of the phenolic resin foam. As the foaming nucleating agent, a gaseous foaming nucleating agent such as a low boiling point substance having a boiling point 50° C. or more lower than that of the foaming agent, such as nitrogen, helium, or argon, can be added. In addition, aluminum hydroxide powder, aluminum oxide powder, calcium carbonate powder, talc, clay clay (kaolin), silica powder, silica sand, mica, calcium silicate powder, wollastonite, glass powder, glass beads, fly ash, silica fume. Solid foam nucleating agents such as gypsum powder, borax, slag powder, inorganic powders such as alumina cement and portland cement, and organic powders such as ground powder of phenolic resin foam can also be added. These may be used alone or in combination of two or more types, regardless of whether they are gas or solid. The timing of adding the foaming nucleating agent can be arbitrarily determined as long as it is supplied into the mixer that mixes the phenolic resin composition.

The amount of the solid foaming nucleating agent added is preferably 3.0% by mass or more and 10.0% by mass or less, and 3.0% by mass or more and 8.0% by mass, based on 100 parts by mass of the phenolic resin composition. It is more preferable that it is below. When the amount of the solid foam nucleating agent added is 3.0% by mass or more, it becomes easier to suppress seepage of the foamable phenolic resin composition from the surface material. Further, by setting the amount of the solid foaming nucleating agent to be 10.0% by mass or less, it becomes easier to suppress the dispersion of the foaming agent having a low boiling point.

The density of the phenolic resin foam of the present invention may be adjusted to a desired density depending on the intended use of the foam, but is preferably 10 kg/m ³ or more and 70 kg/m ³ or less, more preferably 20 kg/m ³ It is not less than 55 kg/m ³ , more preferably not less than 22 kg/m ³ and not more than 50 kg/m ³ , and most preferably not less than 24 kg/m ³ and not more than 45 kg/m ³ . When the density is 10 kg/m ³ or more, the decrease in mechanical strength such as compressive strength, which tends to occur due to the low density, and the decrease in surface brittleness are small, and it is possible to maintain a strength that does not pose any practical problems. When the density is 70 kg/m ³ or less, there is less concern that the thermal conductivity will increase due to heat transfer of the resin portion, which increases due to the high density. The density of the phenolic resin foam can be determined by adjusting the filling ratio of the blowing agent into the phenol resin foam, and mainly depends on the amount of blowing agent added to the phenol resin composition, the temperature of the expandable phenol resin composition, The desired value can be achieved by changing the timing of preforming in the process of discharging the mixed foamable phenolic resin composition, the amount of foaming nucleating agent added, the amount of acidic curing agent added, and curing conditions such as temperature and residence time. It can be adjusted to

The phenolic resin foam of the present invention preferably has a closed cell ratio of 80% or more, more preferably 85% or more, still more preferably 90% or more, and most preferably 92% or more. When the closed cell ratio is 80% or more, it is possible to suppress an increase in thermal conductivity due to air replacing the blowing agent in the phenolic resin foam. This effect is greater as the closed cell ratio is higher. The closed cell ratio of the phenolic resin foam can be adjusted to a desired value by, for example, changing the amount of the foaming nucleating agent, the amount of the foaming agent, and the amount of the acidic curing agent.

The phenolic resin foam in this embodiment has a thermal conductivity at 23°C of preferably 0.0211 W/(m·K) or less, more preferably 0.0200 W/(m·K) or less, and even more preferably is 0.0180 W/(m·K) or less, most preferably 0.0175 W/(m·K) or less.

The void ratio of the phenolic resin foam of this embodiment is preferably 0.5% or less. When the void ratio is 0.5% or less, it becomes difficult to cause a decrease in compressive strength in the thickness direction, and the voids are within a range where they are not noticeable in terms of appearance. The void ratio can be adjusted by adjusting the amount of hydrofluoroether and curing conditions such as temperature and residence time. In the present invention, the void ratio is determined by cutting a cross section parallel to the thickness direction of the resin foam and measuring the voids present in the cross section using the method described ^below . is defined as a void, and the value obtained by dividing the total area of all voids on the cross-sectional area by the cross-sectional area is defined as the void ratio.

<Phenol resin foam laminate>
The phenol resin foam laminate in this embodiment is a laminate that includes a surface material on at least one of one surface of the phenol resin foam and the back surface of the one surface. In addition, the "thickness direction" in this embodiment refers to the dimension of the shortest side among the three sides of the phenolic resin foam laminate, and normally, when manufacturing the phenolic resin foam laminate, the foaming property on the lower surface material is This is the direction in which the phenol resin composition foams and grows.

In addition, the phenolic resin foam laminate can be used alone or in various applications by joining it with an external member. Examples of external members include board-like materials and sheet-like/film-like materials and combinations thereof. Board-like materials include ordinary plywood, structural plywood, particle board, and wood boards such as OSB, wood wool cement board, wood chip cement board, gypsum board, flexible board, medium density fiberboard, calcium silicate board, and silicone board. Suitable materials include acid magnesium plates and volcanic glass multilayer plates. In addition, sheet-like and film-like materials include polyester nonwoven fabric, polypropylene nonwoven fabric, mineral-filled glass fiber nonwoven fabric, glass fiber nonwoven fabric, paper, calcium carbonate paper, polyethylene processed paper, polyethylene film, plastic moisture-proof film, asphalt waterproof paper, and Aluminum foil (with or without holes) is preferable.

Hereinafter, the method for producing a phenolic resin foam will be explained in more detail.

<Raw materials for phenolic resin foam laminates>
As the phenol resin, a resol type phenol resin synthesized from an alkali metal hydroxide or an alkaline earth metal hydroxide is used. Resol type phenolic resin is synthesized by heating phenols and aldehydes as raw materials in a temperature range of 40 to 100°C using an alkali catalyst. Additionally, additives such as urea may be added during or after the synthesis of the resol type phenolic resin, if necessary. When adding urea, it is more preferable to mix urea that has been methylolated with an alkali catalyst in advance with the resol type phenol resin. Since the synthesized resol type phenolic resin usually contains excessive water, the amount of water is adjusted to an appropriate level for foaming. In addition, phenolic resins include aliphatic hydrocarbons, high-boiling alicyclic hydrocarbons, or mixtures thereof, diluents for viscosity adjustment such as ethylene glycol and diethylene glycol, and other additives such as dicyandiamide and melamine as necessary. It is also possible to add additives such as.

The starting molar ratio of phenols to aldehydes during the synthesis of phenolic resins is preferably within the range of 1:1 to 1:4.5, more preferably within the range of 1:1.5 to 1:2.5. It is.

Here, the phenols preferably used in the synthesis of phenolic resin in this embodiment are phenol itself and other phenols. Examples of other phenols include resorcinol, catechol, o-, m- and p-cresol, xylenols, ethylphenols, and p-tertbutylphenol. Furthermore, dinuclear phenols can also be used.

Further, the aldehydes may be any compound that can serve as an aldehyde source, and as the aldehydes, it is preferable to use formaldehyde itself, paraformaldehyde which can be used by depolymerizing, and other aldehydes and derivatives thereof. Examples of other aldehydes include glyoxal, acetaldehyde, chloral, furfural, and benzaldehyde.

The mass average molecular weight of the phenol resin is preferably 300 or more, more preferably 400 or more, and even more preferably 450 or more. The mass average molecular weight is preferably 2,500 or less, more preferably 2,200 or less, even more preferably 2,050 or less, and most preferably 1,900 or less. When the weight average molecular weight of the phenol resin is 300 or more, reaction runaway due to the reaction heat of the curing reaction is less likely to occur, and foam molding can be performed using the reaction heat, resulting in good energy efficiency. In addition, when the mass average molecular weight is 2,500 or less, the bubble diameter tends to become smaller due to less reaction heat of the polymerization reaction, and the resin is difficult to harden in equipment upstream of the board molding process, so the piping is less likely to get dirty and can last for a long time. Can be operated continuously. Note that the mass average molecular weight of the phenol resin can be measured using the method described in the Examples of this specification.

The viscosity of the phenol resin composition at 40° C. is preferably 5,000 mPa·s or more and 100,000 mPa·s or less, more preferably 7,000 mPa·s or more and 50,000 mPa·s or less, and even more preferably 9 ,000 mPa·s or more and 40,000 mPa·s or less. Further, the water content of the phenol resin and the phenol resin composition is preferably 1.5% by mass or more and 20% by mass or less.

The surfactant, hydrofluoroether, foaming agent, and foam nucleating agent may be added to the phenolic resin composition in advance, or may be added at the same time as the acidic curing agent. However, it is preferable to add the hydrofluoroether before or at the same time as the blowing agent.

As the surfactant, those commonly used in the production of phenolic resin foams can be used, but nonionic surfactants are particularly effective; for example, alkylene which is a copolymer of ethylene oxide and propylene oxide oxides, condensates of alkylene oxides and castor oil, condensation products of alkylene oxides and alkylphenols such as nonylphenol and dodecylphenol, polyoxyethylene alkyl ethers whose alkyl ether moiety has 14 to 22 carbon atoms, Furthermore, fatty acid esters such as polyoxyethylene fatty acid ester, silicone compounds such as polydimethylsiloxane, and polyalcohols are more preferable. These surfactants may be used alone or in combination of two or more. There is no particular restriction on the amount used, but it is preferably used in a range of 0.3 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the phenol resin.

The acidic curing agent may be any acidic curing agent that can cure the phenolic resin composition, and contains an organic acid as an acid component. As the organic acid, arylsulfonic acids or anhydrides thereof are preferred. Arylsulfonic acids and their anhydrides include toluenesulfonic acid, xylenesulfonic acid, phenolsulfonic acid, substituted phenolsulfonic acid, xylenolsulfonic acid, substituted xylenolsulfonic acid, dodecylbenzenesulfonic acid, benzenesulfonic acid, naphthalenesulfonic acid, etc. and anhydrides thereof, and these may be used alone or in combination of two or more. In this embodiment, resorcinol, cresol, saligenin (o-methylolphenol), p-methylolphenol, and the like may be added as curing aids. Moreover, these acidic curing agents may be diluted with solvents such as ethylene glycol and diethylene glycol.

The amount of the acidic curing agent used varies depending on the type thereof, and when using a mixture of 80% by mass of xylene sulfonic acid and 20% by mass of diethylene glycol, it is preferably 6 parts by mass based on 100 parts by mass of the phenolic resin composition. The amount used is 20 parts by mass or less, more preferably 8 parts by mass or more and 15 parts by mass or less, and most preferably 11 parts by mass or more and 13 parts by mass or less.

A flexible surface material (flexible surface material) is used as the surface material disposed on at least one of one surface and the back surface of the one surface of the phenolic resin foam. Flexible surface materials used include nonwoven or woven fabrics whose main components are polyester, polypropylene, nylon, etc., kraft paper, glass fiber mixed paper, calcium hydroxide paper, aluminum hydroxide paper, and magnesium silicate paper. Papers such as , and nonwoven fabrics made of inorganic fibers such as glass fiber nonwoven fabrics are preferred, and these may be used in combination (or in a layered manner). In the case where the surface material is peeled off from the obtained phenol resin foam laminate and only the base material is used, inexpensive paper that can be discarded after peeling is preferable. These facing materials are usually provided in roll form. Furthermore, as the flexible surface material, one kneaded with additives such as flame retardants may be used. Note that the method of adhering the surface material and the phenolic resin foam is not particularly limited, and adhesives such as epoxy resin may be used, but from the viewpoint of manufacturing cost and prevention of complication of the manufacturing process, It is preferable that the adhesive force is solely due to the adhesive force when the foamable phenol resin composition is thermally cured on the surface of the surface material.

<Production method of phenolic resin foam laminate>
The method for manufacturing the phenolic resin foam laminate includes a mixing step of mixing the above-mentioned foamable phenolic resin composition in a mixer, and a discharging step of discharging the mixed foamable phenolic resin composition onto the lower surface material. A continuous manufacturing method is used, which includes a foam laminate manufacturing process for manufacturing a phenolic resin foam laminate from a foamable phenolic resin composition discharged onto the lower surface material. It is also possible to adopt a batch method using a mold that performs each step in stages.

In the continuous manufacturing method, the phenolic resin composition discharged onto the lower surface material is coated with the upper surface material, and then preformed so as to be evenly distributed from above and below while foaming and curing. This is then formed into a plate shape. In the continuous manufacturing method, methods for preforming and main forming include methods that use a slat-type double conveyor, methods that use metal rolls or steel plates, and methods that use a combination of these, depending on the manufacturing purpose. There are various methods depending on the situation. For example, when molding is performed using a slat-type double conveyor, the foamable phenolic resin composition coated with the upper and lower surface materials is continuously guided into the slat-type double conveyor, and then heated while By applying pressure from above and below, the material can be foamed and cured to form a plate while adjusting the thickness to a predetermined value. The temperature of the foamable phenolic resin composition when discharged onto the lower surface material depends on the boiling point of the foaming agent, but is generally preferably 32°C or higher and 45°C or lower. When the temperature of the foamable phenolic resin composition is 32°C or higher, the foamable phenolic resin composition tends to foam at an early stage, so that the seepage of the foamable phenolic resin composition from the lower surface material is suppressed. It becomes easier. On the other hand, if the temperature of the foamable phenolic resin composition is 45°C or lower, it will be easier to suppress the dissipation even when using a blowing agent with a low boiling point, resulting in a decrease in foaming efficiency and a decrease in thermal conductivity due to coarsening of the cell diameter. It becomes easier to prevent growth. The temperature of the foamable phenolic resin composition discharged onto the lower surface material can be controlled by adjusting the water temperature, flow rate, rotation speed, etc. of a mixer for mixing various compositions.

<Preforming process>
It is desirable that the heating temperature control conditions for the step of preforming the foamable phenolic resin composition discharged onto the lower surface material while foaming and curing it from above the upper surface material be 30° C. or higher and 80° C. or lower. When the temperature is 30° C. or higher, the effect of promoting foaming in the preforming step can be easily obtained, and curing can be promoted. Further, when the temperature is 80° C. or lower, the vicinity of the center in the thickness direction is less susceptible to internal heat generation, the temperature of the center is less likely to increase, and a decrease in the closed cell ratio can be suppressed. When foaming and curing the expandable phenolic resin composition, in order to efficiently promote curing while suppressing a decrease in the closed cell ratio due to internal heat generation near the center in the thickness direction, following the preforming step, It is important to provide a main molding step and a post-curing step, and to raise the temperature in stages.

<Main molding process>
The heating temperature control conditions for the main forming step following the preforming step are preferably 65° C. or higher and 100° C. or lower. In this section, main forming can be performed using an endless steel belt type double conveyor, a slat type double conveyor, rolls, or the like. Further, the residence time of this molding step is preferably 5 minutes or more and 2 hours or less, since this is the main step of performing foaming and curing reactions. Foaming and curing can be sufficiently promoted when the residence time is 5 minutes or more. When the residence time is within 2 hours, the production efficiency of the phenolic resin foam laminate can be improved. Note that when using a conveyor, it is desirable that the temperature difference between the upper and lower conveyors be less than 4°C.

<Post-curing process>
After heating and controlling the temperature through the preforming step and the temperature control section of the main forming step, a post-curing step is applied. The temperature of the post-curing step is preferably 90°C or higher and 120°C or lower. When the temperature is 90°C or higher, moisture in the foam board is easily dissipated, and when the temperature is 120°C or lower, a decrease in the closed cell ratio of the product can be suppressed and a low thermal conductivity can be maintained for a long period of time. By providing a temperature control section in the post-curing step, water in the foamable phenolic resin composition can be diffused after final molding.

The present invention will be explained in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

<Synthesis of phenolic resin>
A reactor was charged with 3,500 kg of a 52 mass% formaldehyde aqueous solution (52 mass% formalin) and 2,510 kg of 99 mass% phenol (including water as an impurity), stirred with a propeller-rotating stirrer, and reacted with a temperature controller. The temperature of the liquid inside the vessel was adjusted to 40°C. Next, while adding a 48% by mass aqueous sodium hydroxide solution, the temperature was raised to carry out the reaction. When the Ostwald viscosity of the reaction solution reached 110 centistokes (=110×10 ⁻⁶ m ² /s, measured value at 25° C.), the reaction solution was cooled and 398 kg of urea was added. Thereafter, the reaction solution was cooled to 30° C., and the pH was neutralized to 6.4 with a 50% by mass aqueous solution of paratoluenesulfonic acid monohydrate.

This reaction solution was concentrated at 60°C to obtain phenol resin A. In addition, when the mass average molecular weight and viscosity at 40°C of phenol resin A were measured by the following methods, the mass average molecular weight was 1,300, and the viscosity at 40°C was 9,730 mPa·s.

<Mass average molecular weight of phenol resin>
Measurement was performed by gel permeation chromatography (GPC) under the following conditions, and the mass average molecular weight Mw of the phenolic resin was determined from the calibration curve obtained using the standard substances (standard polystyrene, 2-hydroxybenzyl alcohol, and phenol) shown below. I asked for it.
Preprocessing:
About 10 mg of phenol resin was dissolved in 1 ml of N,N dimethylformamide (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., for high performance liquid chromatography), and the solution was filtered through a 0.2 μm membrane filter and used as a measurement solution.
Measurement condition:
Measuring device: Shodex System21 (manufactured by Showa Denko K.K.)
Column: Shodex Asahipak GF-310HQ (7.5mm I.D. x 30cm)
Eluent: 0.1% by mass of lithium bromide was dissolved in N,N dimethylformamide (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., for high-performance liquid chromatography).
Flow rate: 0.6ml/min Detector: RI detector Column temperature: 40°C
Standard materials: Standard polystyrene (Shodex STANDARD SL-105, manufactured by Showa Denko K.K.), 2-hydroxybenzyl alcohol (manufactured by Sigma-Aldrich, 99% product), phenol (manufactured by Kanto Kagaku Co., Ltd., special grade)

<Viscosity measurement of phenolic resin>
Using a rotational viscometer (manufactured by BrookField metek, DVNXHBCBG type, rotor part: CPA-52Z), the measured value after stabilizing 0.5 ml of phenol resin at 40° C. for 6 minutes was taken as the viscosity of the phenol resin.

(Example 1)
Ratio of 3.0 parts by mass of a composition containing 50% by mass of ethylene oxide-propylene oxide block copolymer and polyoxyethylene dodecyl phenyl ether as surfactants, based on 100 parts by mass of phenolic resin A. mixed with. This is used as a phenol resin composition. As a foaming nucleating agent, 4.0% by mass of phenolic resin foam powder was added to the phenolic resin composition containing the surfactant. The viscosity of the phenolic resin composition after kneading the phenolic resin foam powder at 40° C. was 22,000 mPa·s. Further, for 100 parts by mass of the above phenolic resin composition, 3.0 parts by mass of 3M Novec (registered trademark) 7000 (manufactured by 3M Company) as a hydrofluoroether and 13 parts by mass of HCFO-1233zd(E) as a blowing agent. 13 parts by mass of a composition consisting of a mixture of 80% by mass of xylene sulfonic acid and 20% by mass of diethylene glycol was added as an acidic curing agent, and the mixture was supplied to a variable rotation speed mixing head whose temperature was controlled to 17°C. The phenolic resin foam powder used here was a pulverized phenol resin foam (neoma foam manufactured by Asahi Kasei Kenzai Co., Ltd.) powder (average particle size was 28 μm and bulk density was 181 kg/m ³ ), and was kneaded with the phenol resin composition in a twin-screw extruder before adding the hydrofluoroether, blowing agent, and acidic curing agent. Thereafter, the hydrofluoroether, foaming agent, and acidic curing agent were mixed in a mixer, and the resulting foamable phenolic resin composition was distributed using a multiport distribution pipe and supplied onto the moving lower surface material. The mixer disclosed in FIG. 1 of JP-A No. 10-225993 was used. That is, on the upper side of the mixer, an inlet for a phenolic resin composition containing a solid foaming nucleating agent, an inlet for a hydrofluoroether, and an inlet for a blowing agent are arranged adjacently from top to bottom in order, and the rotor A mixer was used, which was equipped with an acid curing agent inlet on the side near the center of the stirring section. The part after the stirring part is connected to a nozzle for discharging the foamable phenolic resin composition. That is, the mixer consists of a mixing section (first stage) up to the acidic curing agent inlet, a mixing section (second stage) between the acidic curing agent inlet and the stirring end section, and a distributing section between the stirring end section and the nozzle. There is. The distribution section has a plurality of nozzles at its tip and is designed to uniformly distribute the mixed foamable phenolic resin composition. Furthermore, the distribution section had a jacket type structure, which enabled sufficient heat exchange with temperature-controlled water, and the temperature of the temperature-controlled water in the distribution section was set at 17°C. Further, a thermocouple was installed at the discharge port of the multi-port distribution pipe so that the temperature of the foamable phenolic resin composition could be detected, and the rotation speed of the mixer was set at 500 rpm. At this time, the temperature of the foamable phenol resin composition discharged onto the lower surface material was 34°C. The foamable phenolic resin composition supplied onto the lower surface material was introduced into a preforming step whose temperature was controlled at 40° C., and after 30 seconds, preforming was performed from above the upper surface material using a free roller. The residence time in this step was 5 minutes. After that, it is sandwiched between two surface materials and introduced into a slat-type double conveyor heated to 69℃ (main forming process), where it is cured for 15 minutes and then 9 minutes at 100℃. Thereafter, it was cured at 110° C. for 2 hours (post-curing step) to obtain a phenol resin foam laminate having a thickness of about 30 mm. In addition, as a surface material, polyester nonwoven fabric (Asahi Kasei Corporation Eltas E05060, basis weight 60 g/m ² ) was used for both the upper and lower surface materials. Such a manufacturing method is indicated as manufacturing method A in Table 2.

Characteristic evaluation of the obtained phenolic resin foam and phenolic resin foam laminate (identification and content measurement of hydrofluoroether in the phenolic resin foam, identification of blowing agent species, measurement of average cell diameter, measurement of density, Measurement of thermal conductivity in a 23°C environment, measurement of compressive strength in the thickness direction, evaluation of color spots and void ratio, and measurement of closed cell ratio) were performed by the following methods.

<Identification and content measurement of hydrofluoroether in phenolic resin foam, identification of blowing agent species>
First, retention times were determined under the following GC/MS measurement conditions using hydrofluoroether, hydrofluoroolefin, halogenated hydrocarbon, and hydrocarbon standard gases.

A 0.25 mg sample was cut out from near the center of the phenolic resin foam, placed in a special container, and 10 ml of chloroform and 12 crushed glass beads were added. After extracting components into chloroform while grinding the sample at 6000 rpm x 7 to 11 min with a homogenizer (IKA ULTRA-TURRAX Tube Drive), the extract was filtered with a 0.45 μm filter and subjected to GC/MS measurement. A standard sample solution with a known concentration was prepared by dissolving the target component for quantitative determination in chloroform, and subjected to GC/MS measurement under the same conditions as the sample.

Hydrofluoroethers, hydrofluoroolefins, halogenated hydrocarbons, and hydrocarbons were identified from the retention times and mass spectra determined in advance. Separately, the detection sensitivity of each generated gas component was measured using a standard gas, and the content of each substance was calculated from the detection area area and detection sensitivity of each gas component obtained by GC/MS. The mass % of each blowing agent component was calculated from the hydrofluoroether content (mass % based on the phenol resin foam) and the blowing agent content and molar mass from the content of each identified gas component.

(GC-MS measurement conditions)
GC device: Agilent 6890
Column: DB1 (30m, 0.25mmφ, film thickness 0.25μm)
Column temperature: 40°C (5 min) - (20°C/min. temperature increase) -200°C
Flow rate: 1mL/min
Inlet temperature: 320℃
Injection method: Split method (1/50)
Sample injection volume: 1 μL
MS device: JEOL AutoMass-SUN
Interface temperature: 300℃
Ionization method: EI method 70eV
Measurement method: Scan
Scan range: m/z=20-600
Ion source temperature: 240℃

<Measurement of average cell diameter of phenolic resin foam>
The average bubble diameter was measured by the following method. Four photos were taken with a scanning electron microscope of the air bubbles at approximately the center in the thickness direction of the phenolic resin foam laminate, and at approximately the center between the center and the front and back surfaces, magnified 50 times. Draw four straight lines with a length of 90 mm (corresponding to 1,800 μm in the actual foam cross section) avoiding voids, and calculate the number of bubbles for each straight line based on the number of bubbles crossed by each straight line. , the value obtained by dividing 1,800 μm by their average value was defined as the average bubble diameter.

<Measurement of density of phenolic resin foam>
A 200 mm square phenol resin foam laminate was used as a sample. After removing the surface material from this sample, the mass and apparent volume were determined according to JIS K7222.

<Measurement of thermal conductivity of phenolic resin foam laminate under 23°C environment>
In accordance with JIS A 1412-2:1999, the thermal conductivity in the thickness direction of the resin foam laminate was measured in a 23° C. environment using the following method. The specific steps are as follows.

A phenol resin foam laminate was cut into 300 mm square pieces, and the specimens were placed in an atmosphere of 23±1°C and humidity of 50±2%. Thereafter, the change in weight over time was measured every 24 hours, and the condition was checked and adjusted until the weight change after 24 hours was 0.2% by mass or less. The conditioned phenolic resin foam laminate specimen was introduced into the thermal conductivity apparatus, which was also placed in an atmosphere of 23±1° C. and humidity of 50±2%. If the thermal conductivity measuring device is not placed in the room where the phenolic resin foam laminate specimen was placed, where the humidity is controlled at 23 ± 1% and the humidity is 50 ± 2%, it is necessary to The tested and adjusted specimens were immediately placed in a polyethylene bag, the bag was closed, and the bag was taken out within 1 hour, and the thermal conductivity was immediately measured.

The thermal conductivity was measured at 23°C under the conditions of a low-temperature plate at 13°C and a high-temperature plate at 33°C, using a measuring device with a single test piece and target configuration method (Hideko Seiki Co., Ltd., product name "HC-074/FOX304"). ”) was used.

<Measurement of compressive strength in the thickness direction of phenolic resin foam>
After removing the face material from the obtained phenolic resin foam laminate, the compressive strength in the thickness direction of the phenolic resin foam was measured in accordance with JIS K7220. However, the dimensions of the foam were 100 mm x 100 mm x 30 mm.

<Evaluation of color spots on phenolic resin foam>
The cross section of the phenolic resin foam in the thickness direction was visually observed. As a result, if there are streaks or localized variations in bubble diameter that can be visually confirmed other than voids, and the color of the foam appears uneven due to this, it is evaluated as having color spots. Those that did not fall under these conditions were evaluated as "no" color spots.

<Void rate evaluation of phenolic resin foam>
Cut approximately the center of the thickness of the phenolic resin foam parallel to the front and back surfaces, enlarge the 100 mm x 150 mm area by 200% (4.0 times the area), make a color copy, and use transparent graph paper to make a 1 mm x 1 mm size. The area of voids with 8 squares or more (2.0 mm ² or more) is integrated, the area fraction is calculated, and the void ratio (%) (average value of 4 measurements) is calculated, and the void ratio of the phenolic resin foam is calculated. Those in which the ratio was 0.5% or less were rated as "little," and those in excess of 0.5% were rated as "high."

<Measurement of closed cell ratio of phenolic resin foam>
If the thickness of the resin foam is 25 mm or more, a 25 mm square cube is cut out as a sample at the center position in the thickness direction of the phenolic resin foam using a cutting tool such as a band saw. In addition, if the thickness of the resin foam is less than 25 mm, the thickness after removal of the face material (if fibrous material derived from the face material remains, or if there is a face material on the back side), and the thickness is 25 mm in both length and width. Cut out a rectangular parallelepiped as a sample. Then, the sample volume V (cm ³ ) is measured using the standard method of using an air comparison hydrometer (model 1000, manufactured by Tokyo Science Co., Ltd.). The closed cell ratio in a resin foam is calculated from the sample volume V, the sample mass W (g), and the density ρ of the resin composition constituting the resin foam, as shown in the following formula. ) is divided by the apparent volume Va (cm ³ ) calculated from the external dimensions of the sample, and is measured in accordance with ASTM D 2856 (Method C). The density of the phenol resin composition was calculated as 1.27 kg/L.
Closed cell ratio (%) = ((V-W/ρ)/Va) x 100

(Example 2)
A resin foam was produced in exactly the same manner as in Example 1, except that the hydrofluoroether was changed to 3M Novec (registered trademark) 7100 high-performance liquid (manufactured by 3M).

(Example 3)
A resin foam was produced in exactly the same manner as in Example 1, except that the hydrofluoroether was changed to 3M Novec (registered trademark) 7200 high performance liquid (manufactured by 3M).

(Example 4)
A resin foam was produced in exactly the same manner as in Example 1, except that the hydrofluoroether was changed to 3M Novec (registered trademark) 7300 high-performance liquid (manufactured by 3M).

(Example 5)
A resin foam was produced in exactly the same manner as in Example 1, except that the hydrofluoroether was changed to Asahiklin (registered trademark) AE-3000 (manufactured by AGC, purity 99% or higher).

(Example 6)
The procedure was carried out in exactly the same manner as in Example 1, except that the hydrofluoroether was changed to Novec (registered trademark) 7200 (manufactured by 3M) and the amount of hydrofluoroether added was 0.1 part with respect to 100 parts by mass of the phenolic resin composition. A resin foam was produced.

(Example 7)
The procedure was carried out in exactly the same manner as in Example 1 except that the hydrofluoroether was changed to Novec (registered trademark) 7200 (manufactured by 3M) and the amount of hydrofluoroether added was 6.5 parts with respect to 100 parts by mass of the phenolic resin composition. A resin foam was produced.

(Example 8)
The resin was prepared in exactly the same manner as in Example 1, except that the hydrofluoroether was changed to Novec (registered trademark) 7200 (manufactured by 3M Company), and 14 parts by mass of HCFO-1224yd (Z) (manufactured by AGC Company) was used as the blowing agent. A foam was produced.

(Example 9)
The hydrofluoroether was changed to Novec (registered trademark) 7200 (manufactured by 3M), and the blowing agent was a mixture of 80% by mass of HCFO-1224yd (Z) (manufactured by AGC) and 20% by mass of cyclopentane. A resin foam was produced in exactly the same manner as in Example 1, except that the amount added was 12 parts by mass.

(Example 10)
A resin foam was produced in exactly the same manner as in Example 1, except that the hydrofluoroether was changed to Novec (registered trademark) 7200 (manufactured by 3M) and 6.3 parts by mass of cyclopentane was used as the blowing agent.

(Example 11)
The hydrofluoroether was changed to Novec (registered trademark) 7200 (manufactured by 3M), HCFO-1224yd (Z) (manufactured by AGC) was used as a blowing agent, the amount of blowing agent added was 14 parts by mass, and the hydrofluoroether A resin foam was produced in exactly the same manner as in Example 1, except that the inlet was installed on the downstream side of the mixer so that the hydrofluoroether was kneaded after the blowing agent. Such a manufacturing method is indicated as manufacturing method B in Table 2.

(Example 12)
Ratio of 3.0 parts by mass of a composition containing 50% by mass of ethylene oxide-propylene oxide block copolymer and polyoxyethylene dodecyl phenyl ether as surfactants, based on 100 parts by mass of phenolic resin A. mixed with. This is used as a phenol resin composition. 3.0 parts by mass of 3M Novec (registered trademark) 7200 (manufactured by 3M Company) as a hydrofluoroether was added to 100 parts by mass of the phenolic resin composition containing the above surfactant in a polycup, and a cordless screwdriver was added. After kneading with a stirring rod attached to a drill (Hi-Koki DS 10DAL), HCFO-1233zd (E) as a blowing agent was further kneaded using a cordless driver drill while cooling the polycup so that the amount was 12 parts by mass. Although no foaming nucleating agent was added here, the air involved during kneading played the role of the foaming nucleating agent. It was confirmed by the change in the weight of the resin composition that each of the resin compositions had been kneaded in a predetermined amount. Next, the polycup containing the foamable phenolic resin composition was cooled in the refrigerator for 1 hour, and after confirming that the foamable phenolic resin composition was at 12°C or lower, 80% by mass of xylene sulfonic acid and diethylene glycol were added as acidic curing agents. 13 parts by mass of a composition consisting of a 20% by mass mixture was added and kneaded with a cordless screwdriver drill for 2 minutes in an ice bath. Next, the foamable phenolic resin composition was applied to the bottom of a metal frame (form) using a spatula in an environment of 13°C. The amount of the foamable phenol resin composition applied was adjusted as appropriate so that the thickness would not protrude from the metal frame (form) after foaming. The metal frame (form) used here is made of metal with a thickness of 2.0 mm, and has an inner diameter of 300 mm x 300 mm x height of 30 mm, with holes of 5 mm diameter punched at 1 mm intervals on the bottom. A polyester nonwoven fabric (Eltas E05060 manufactured by Asahi Kasei Corporation, basis weight 60 g/m ² ) was laid as a surface material. The working time from kneading the foamable phenolic resin composition and acidic curing agent to finishing the application was 5 minutes. After that, as a top plate, cover a board larger than 300 mm x 300 mm with the same punching specifications as the bottom with the same surface material as the bottom of the metal frame (formwork) so that the surface material faces the foamed phenolic resin side. The top plate was fixed to the metal frame (formwork) with clips. Place this metal frame (formwork) in an oven heated to 85℃, place a 25kg weight heated to 85℃ in the center of the top plate of the metal frame (formwork), heat it for 1 hour, and then heat it again at 105℃ for 1 hour. After curing for a period of time, a phenol resin foam laminate having a thickness of 30 mm was obtained. Such a manufacturing method is indicated as manufacturing method C in Table 2.

(Comparative example 1)
A resin foam was produced in exactly the same manner as in Example 1, except that AMOLEA (registered trademark) AS-300 (manufactured by AGC, purity 99% or more), which is a fluorine compound that does not correspond to Formula 1, was used.

(Comparative example 2)
Resin foaming was carried out in the same manner as in Example 1, except that the hydrofluoroether was changed to Novec (registered trademark) 7200 (manufactured by 3M) and the amount of hydrofluoroether added was 7 parts with respect to 100 parts by mass of the phenolic resin composition. manufactured a body.

(Comparative example 3)
A resin foam was produced in exactly the same manner as in Example 1, except that no hydrofluoroether was added.

(Comparative example 4)
A resin foam was produced in exactly the same manner as in Example 8, except that no hydrofluoroether was added.

(Comparative example 5)
A resin foam was produced in exactly the same manner as in Example 9, except that no hydrofluoroether was added.

(Comparative example 6)
A resin foam was produced in exactly the same manner as in Example 10, except that no hydrofluoroether was added.

(Comparative example 7)
A resin foam was produced in exactly the same manner as in Example 12, except that no hydrofluoroether was added.

Table 1 shows the types of hydrofluoroethers used in Examples 1 to 12 and Comparative Examples 1 and 2. In addition, the measurement and evaluation tests described above were conducted for Examples 1 to 12 and Comparative Examples 1 to 7. Measurement results and evaluation results are shown in 2.

The phenolic resin foam and its laminate of this embodiment have a small cell diameter, so they may have excellent heat insulation performance, and the appearance defects such as voids and uneven color of the foam, as well as the compressive strength, are improved. Therefore, it can be used in various places that require insulation, for example. In addition, since the raw materials are cheaper than the conventional technology, the capital investment is small, and the GWP is small, it is possible to provide an environmentally friendly foam with a small environmental impact.

Claims

A phenolic resin foam containing 0.03 to 4.3% by mass of a hydrofluoroether represented by the following (Formula 1) based on the phenolic resin foam.
(Formula 1): C a H b F c -O-C x H y F z
(However, a, b, c, x, y, z are integers, 2≦a≦7, 0≦b≦3, c=2a+1-b, b≦2a+1, 1≦x≦3, 2≦y ≦7, z=2×x+1-y, y≦2x+1)
The hydrofluoroether represented by (Formula 1) is methyl perfluoropropyl ether, methyl nonafluorobutyl ether, methyl nonafluoroisobutyl ether, ethyl nonafluorobutyl ether, ethyl nonafluoroisobutyl ether, 1,1,1,2,2 , 3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)-pentane, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether The phenolic resin foam according to claim 1, which is any one of the following.
The phenolic resin foam according to claim 1 or 2, having an average cell diameter of 70 μm or more and 180 μm or less.
The phenolic resin foam according to claim 1 or 2, wherein the blowing agent contains a hydrofluoroolefin.
The phenolic resin foam according to claim 4, wherein the blowing agent contains a hydrocarbon.
The phenolic resin foam according to claim 1 or 2, having a density of 10 kg/m 3 or more and 70 kg/m 3 or less.
The phenolic resin foam according to claim 1 or 2, having a closed cell ratio of 80% or more.
The phenolic resin foam according to claim 3, having a closed cell ratio of 80% or more.
The phenolic resin foam laminate according to claim 1 or 2, comprising a surface material on at least one of one surface of the phenolic resin foam and the back surface of the one surface.