Phenolic resin foam and method for producing same

Abstract

An ion chromatogram of a gas component generated by heating the phenolic resin foam at 600 DEG C is obtained by gas chromatography-mass spectrometry. The area ratio Z (Z = X / Y) of the total X (X = A + B + C) of the area A of the dihydroxybenzene derived from the pyrolysis product, the area B of the dihydroxytoluene derived from the pyrolysis product, and the area C of the dihydroxyxylene derived from the pyrolysis product to the area Y of the pyrolysis product representing the structure derived from urea crosslinking is within the range of formula (1). The phenolic resin foam has a thermal conductivity of 0.0240 W / (m.K) or less in an environment of 23 DEG C. 0.035 < = Z < = 0.715 (1)

Description

[0001] Cross-reference of related applications

[0002] This application claims priority to Japanese Patent Application No. 2023-075252, filed in Japan on April 28, 2023, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to phenolic resin foam and its manufacturing method. Background Technology

[0004] Acid-cured phenolic resin foam made from methyl phenolic resin not only exhibits excellent thermal insulation properties, but is also not easily combustible and produces little smoke. Therefore, it has been used not only as an exterior wall material for metal wall panels and an interior wall material for partition panels, but also as a building material for ceilings, fire doors and rainproof windows, and is widely used as a cold and heat insulation material for industrial equipment.

[0005] In recent years, due to concerns about global warming, the reduction of greenhouse gases has become a top priority. Among these measures, the use of plant-derived materials as raw materials for products has attracted attention as one of the means to reduce greenhouse gases such as carbon dioxide produced during incineration. Foamed products using plant-derived materials as raw materials, based on their usage, can be considered to have the same amount of carbon dioxide produced during incineration as the amount absorbed by the plants. Therefore, this can be understood as a carbon neutrality technology that does not affect the increase or decrease of carbon dioxide in the atmosphere.

[0006] Lignin is a plant-derived material whose utilization has long been studied. Lignin is a component recovered from plant pulp production. It is classified into woody and herbaceous plants based on the species of plant used as raw material. Furthermore, depending on the extraction method used in pulp production, it is classified into sulfate lignin, lignin sulfonic acid, soda lignin, etc. Because of its phenolic skeleton, lignin has been the subject of attempts to create complexes with phenolic resins.

[0007] Patent Document 1 discloses a method for manufacturing foamed phenolic resin by adding lignin sulfonate to phenolic resin of the first stage, which allows for control of the foaming and curing speed. Patent Document 2 discloses a method for providing bio-based phenolic resin foam by adding organically soluble lignin or pyrolytic lignin to a condensate of a mixture of phenol, formaldehyde, and an alkaline catalyst.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent No. 1578980

[0011] Patent Document 2: Japanese Patent No. 5885855 Summary of the Invention

[0012] The problem the invention aims to solve

[0013] However, in Patent Document 1, the phenolic resin foam with added lignin sulfonate, as described in the examples, has a high thermal conductivity, thus failing to utilize the inherently low thermal conductivity of phenolic resin foam. Furthermore, increasing the amount of lignin sulfonate added further delays the curing time, which is not preferable from a productivity standpoint.

[0014] On the other hand, in Patent Document 2, the phenolic resin foam containing organic soluble lignin or pyrolytic lignin, like in Patent Document 1, cannot be said to have sufficient thermal conductivity compared to the phenolic resin foam without added lignin compounds. Furthermore, the phenolic resin foam in Patent Document 2 requires more than 24 hours for foaming and curing, which is not preferable from a productivity point of view.

[0015] Therefore, phenolic resin foam containing lignin and having low thermal conductivity is desired. Furthermore, a technology exhibiting the same foaming and curing time and the same low thermal conductivity as lignin-free phenolic resin foam is required.

[0016] Solution for solving the problem

[0017] Therefore, the inventors have conducted repeated and in-depth research to solve the above-mentioned problems, and as a result, developed the following technology: by appropriately adjusting the moisture content of lignin and optimizing the moisture content of the lignin-containing phenolic resin composition, the lignin-containing phenolic resin foam exhibits the same foaming and curing time and the same thermal conductivity as the lignin-free phenolic resin foam. That is, the present invention is as follows. [1]

[0019] A phenolic resin foam, wherein in the ion chromatogram of the gaseous components generated by heating at 600°C, obtained by gas chromatography-mass spectrometry analysis, the area ratio Z (Z=X / Y) of the sum of the area A of dihydroxybenzene derived from the pyrolysis product, the area B of dihydroxytoluene derived from the pyrolysis product, and the area C of dihydroxyxylene derived from the pyrolysis product, is within the range of the following formula (1), and the thermal conductivity of the phenolic resin foam at 23°C is 0.0240 W / (m·K) or less.

[0020] 0.035≤Z≤0.715 (1) [2]

[0022] According to [1], the density of the phenolic resin foam is 10 kg / m³. 3 Above and 50kg / m 3 the following. [3]

[0024] The phenolic resin foam according to any one of [1] or [2] has an average bubble diameter of 70 μm or more and 250 μm or less. [4]

[0026] The phenolic resin foam according to any one of [1] to [3] contains any one of hydrofluoroolefins, hydrocarbons, and chlorinated hydrocarbons. [5]

[0028] The phenolic resin foam according to any one of [1] to [4], wherein at least one of one side of the phenolic resin foam and the back side of the same side has a surface material. [6]

[0030] A method for manufacturing a phenolic resin foam laminate as described in [5] involves foaming and curing a lignin-containing foamable phenolic resin composition on a surface material.

[0031] The manufacturing method for obtaining the foamed phenolic resin composition includes at least one of the following steps: adding lignin to phenols; adding lignin during the synthesis of phenolic resin; adding lignin to the phenolic resin; and adding lignin to the phenolic resin composition.

[0032] The lignin has a moisture content of less than 34.0%.

[0033] The lignin-containing phenolic resin composition in the foamed phenolic resin composition has a water content of 1.5% by mass or more and 6.5% by mass or less. [7]

[0035] According to the manufacturing method of phenolic resin foam laminate described in [6], in the step of adding lignin, the median particle size of the added lignin powder is 0.1 μm or more and 300 μm or less.

[0036] The effects of the invention

[0037] The phenolic resin foam of the present invention, by appropriately adjusting the moisture content of lignin and the moisture content of the phenolic resin composition containing lignin, enables the maintenance of foaming and curing time even for phenolic resin foams containing lignin, allowing for production without reducing productivity. Furthermore, it suppresses foaming obstacles caused by water, and by maintaining fine pores, it maintains thermal conductivity and insulation properties even for phenolic resin foams containing lignin. Additionally, by using plant-derived materials, a bio-based phenolic resin foam can be provided. Detailed Implementation

[0038] This invention discovers the conditions for adding plant-derived materials required to maintain foaming curing time and thermal insulation properties, and also discovers a phenolic resin foam that has been impossible to achieve until now, simultaneously satisfying low thermal conductivity, high productivity and bio-based properties.

[0039] The following is a detailed description of the method for carrying out the present invention (hereinafter referred to as "this embodiment"). It should be noted that the present invention is not limited to the following embodiment, and various modifications can be made within its scope. Furthermore, in this specification, a composition in which a surfactant is added relative to a "phenolic resin" is referred to as a "phenolic resin composition," and a substance containing lignin in a "phenolic resin composition" is specifically referred to as a "lignin-containing phenolic resin composition." A composition in which a foaming agent, a foaming nucleating agent, and an acidic curing agent are added relative to a "phenolic resin composition" or a "lignin-containing phenolic resin composition" to impart foaming properties or both foaming and curing properties is referred to as a "foaming phenolic resin composition." Furthermore, the resulting foam is referred to as a "phenolic resin foam." It should be noted that a laminate in which at least one side and the back side of a phenolic resin foam has a surface material is referred to as a "phenolic resin foam laminate."

[0040] The phenolic resin foam in the embodiments of this application contains lignin. The presence or absence of lignin in the phenolic resin foam, as described below, can be determined by performing pyrolysis gas chromatography-mass spectrometry analysis on the phenolic resin foam.

[0041] For phenolic resin foams containing lignin, when the gaseous components generated by heating at 600℃ are analyzed by gas chromatography-mass spectrometry (GC-MS), with the retention time for detecting phenol in the obtained total ion chromatogram set to t minutes, pyrolysis products derived from dihydroxybenzene are detected near a retention time of 1.38 × t minutes in the extractable ion chromatogram at m / z=110; pyrolysis products derived from dihydroxytoluene are detected near a retention time of 1.46 × t minutes and near a retention time of 1.50 × t minutes in the extractable ion chromatogram at m / z=138; and pyrolysis products derived from dihydroxyxylene are detected near a retention time of 1.58 × t minutes in the extractable ion chromatogram at m / z=138. It should be noted that, using the pyrolysis GC-MS analysis method described later, phenol is detected near a retention time of 10.0 minutes.

[0042] In the extract ion chromatogram of the obtained pyrolysis products at m / z=110, the area of ​​the pyrolysis product derived from dihydroxybenzene detected near a retention time of 1.38 × t minutes is designated as A; the sum of the areas of the pyrolysis products derived from dihydroxytoluene detected near a retention time of 1.46 × t minutes and the areas of the pyrolysis products derived from dihydroxytoluene detected near a retention time of 1.50 × t minutes in the extract ion chromatogram of m / z=124 is designated as B; the area of ​​the pyrolysis product derived from dihydroxyxylene detected near a retention time of 1.58 × t minutes in the extract ion chromatogram of m / z=138 is designated as C; and the sum of A, B, and C is designated as X (X = A + B + C). Furthermore, when the area representing the pyrolysis product derived from the urea crosslinking structure is designated as Y, the ratio to X is designated as Z (Z = X / Y). It should be noted that the pyrolysis product representing the structure derived from urea crosslinking, for example, peak 9 in [Figure 1] of Japanese Patent No. 4711469, was detected in the total ion chromatogram at a retention time of approximately 1.50 × t minutes. It should also be noted that in the extracted ion chromatogram, the values ​​of areas A, B, and C vary depending on the type of lignin and the amount of lignin added relative to the phenolic resin composition. Furthermore, the value of area Y does not vary depending on the timing of lignin addition. Additionally, the areas A, B, C, and Y are calculated using the intersection with the baseline or the inflection point of an adjacent peak as boundaries.

[0043] In the ion chromatogram of the obtained pyrolysis product, Z is 0.035 or more and 0.715 or less, preferably 0.040 or more and 0.40 or less. More preferably 0.055 or more and 0.23 or less, even more preferably 0.065 or more and 0.18 or less. Most preferably 0.075 or more and 0.11 or less. Values ​​smaller than 0.035 indicate a low proportion of plant-derived materials in the phenolic resin foam, resulting in low value as a bio-based material. Values ​​larger than 0.715 indicate a significantly high proportion of lignin in the phenolic resin foam; however, increasing the lignin ratio leads to increased viscosity when added to the phenolic resin, which is undesirable. Furthermore, when used as an insulation material, lignin functions as a thermal bridge, resulting in increased thermal conductivity.

[0044] The phenolic resin foam of the present invention comprises a foaming agent described later.

[0045] The density of the phenolic resin foam of the present invention can be adjusted to a desired density according to the intended use of the foam, preferably 10 kg / m³. 3 Above and 50kg / m 3 The following is more preferably 20 kg / m 3 Above and 50kg / m 3 The following is a further preferred value: 22 kg / m 3 Above and 50kg / m 3 The optimal value is 24 kg / m³. 3 Above and 45kg / m3 Below. At a density of 10 kg / m³ 3 In the above cases, the reduction in mechanical strength, such as compressive strength, and / or surface brittleness, which is prone to occur due to low density, is small, and the strength can be maintained without practical problems. At a density of 50 kg / m³... 3 In the following cases, concerns about increased thermal conductivity due to the increased thermal conductivity of the phenolic resin portion caused by its higher density are reduced. It should be noted that the density of the phenolic resin foam can be adjusted simply by changing the filling ratio of the foaming agent to the phenolic resin foam. This can be achieved primarily by adjusting the amount of foaming agent added to the phenolic resin composition, the temperature of the foaming phenolic resin composition, the timing of preforming in the process of spraying the mixed foaming phenolic resin composition, and changes in curing conditions such as the amount of foaming nucleating agent added, the amount of acidic curing agent added, and the temperature and / or residence time.

[0046] The average bubble diameter of the phenolic resin foam of the present invention is preferably 70 μm or more and 250 μm or less, more preferably 70 μm or more and 130 μm or less, even more preferably 70 μm or more and 120 μm or less, and most preferably 70 μm or more and 110 μm or less. If the average bubble diameter is 70 μm or more, the increase in thermal conductivity caused by the increased thermal conductivity of the phenolic resin portion due to the smaller bubble diameter can be suppressed. Furthermore, when the bubble diameter is 250 μm or less, the thermal conductivity caused by radiation within the bubble is small, and the increase in thermal conductivity can be suppressed. It should be noted that the average bubble diameter of the phenolic resin foam can be adjusted to a desired value, for example, by changing the amount of solid foaming nucleating agent added, the temperature of the foaming phenolic resin composition, the timing of preforming in the process of spraying the mixed foaming phenolic resin composition onto the lower surface material, the amount of foaming agent added, the amount of acidic curing agent added, and curing conditions such as temperature and / or residence time.

[0047] The phenolic resin foam in this embodiment has a thermal conductivity of 0.024 W / (m·K) or less at 23°C, preferably 0.02330 W / (m·K) or less. More preferably, it has a thermal conductivity of 0.02230 W / (m·K) or less, even more preferably, it has a thermal conductivity of 0.02150 W / (m·K) or less, and most preferably, it has a thermal conductivity of 0.02115 W / (m·K) or less.

[0048] As a phenolic resin foam laminate, it can be used alone or combined with external components for various applications. Examples of external components include sheet materials and sheet / film materials and combinations thereof. Preferred sheet materials include ordinary plywood, structural plywood, particleboard, wood-based panels such as OSB, wood wool cement board, wood chip cement board, gypsum board, flexible board, medium-density fiberboard, calcium silicate board, magnesium silicate board, and volcanic vitreous plywood. Preferred sheet / film materials include polyester nonwoven fabric, polypropylene nonwoven fabric, inorganic-filled glass fiber nonwoven fabric, glass fiber nonwoven fabric, paper, calcium carbonate paper, polyethylene processed paper, polyethylene film, plastic-based moisture-proof film, asphalt waterproof paper, and aluminum foil (porous / non-porous).

[0049] The manufacturing method of phenolic resin foam is described in more detail below.

[0050] <Raw Materials for Phenolic Resin Foam>

[0051] As the phenolic resin, a first-stage phenolic resin synthesized using alkali metal hydroxides or alkaline earth metal hydroxides is used. The first-stage phenolic resin is synthesized from phenols and aldehydes using an alkaline catalyst at a temperature range of 40–100°C. Alternatively, additives such as urea may be added during or after the synthesis of the first-stage phenolic resin, as needed. When urea is added, it is more preferable to mix urea that has been pre-hydroxymethylated with an alkaline catalyst with the first-stage phenolic resin. The synthesized first-stage phenolic resin typically contains excess water, so the water content is adjusted to a suitable level for foaming during foaming. Furthermore, aliphatic hydrocarbons or high-boiling-point alicyclic hydrocarbons, or mixtures thereof, and / or viscosity-adjusting diluents such as ethylene glycol and diethylene glycol, as well as additives such as dicyandiamide and / or melamine, may be added to the phenolic resin as needed. Additionally, lignin may be added during or after the synthesis of the first-stage phenolic resin, as needed.

[0052] The initial molar ratio of phenols to aldehydes during the synthesis of phenolic resins is preferably in the range of 1:1 to 1:4.5, more preferably in the range of 1:1.5 to 1:2.5. Alternatively, lignin may be dissolved in the phenols used for synthesis beforehand, as needed.

[0053] In this embodiment, the preferred phenols used in the synthesis of phenolic resins are phenol itself and other phenols. Examples of other phenols include resorcinol, catechol, o-cresol, m-cresol, p-cresol, xylenol, ethylphenol, and p-tert-butylphenol. Alternatively, diphenols may also be used.

[0054] Furthermore, any compound that can serve as an aldehyde source is acceptable. Preferably, formaldehyde itself, paraformaldehyde capable of depolymerization and utilization, and other aldehydes and / or their derivatives are used. Examples of other aldehydes include glyoxal, acetaldehyde, chloral, furfural, and benzaldehyde.

[0055] The weight-average molecular weight of the phenolic resin is preferably 300 or more, more preferably 400 or more, and even more preferably 450 or more. Furthermore, this weight-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 phenolic resin is 300 or more, it is less prone to runaway reaction caused by the heat of reaction during curing, allowing for foaming and molding using the heat of reaction, thus resulting in good energy efficiency. Furthermore, when the weight-average molecular weight is 2,500 or less, the heat of reaction during polymerization is low, making it easier to reduce the bubble diameter. This makes it difficult for the resin to cure in equipment upstream of the sheet forming process, thus reducing piping contamination and enabling long-term continuous operation. It should be noted that the weight-average molecular weight of the phenolic resin can be determined using the method described in the examples of this specification.

[0056] The viscosity of the phenolic 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.

[0057] Lignin, surfactants, foaming agents, and foaming nucleating agents can be added to the phenolic resin composition in advance or simultaneously with the acid curing agent.

[0058] As lignins, woody lignins and herbaceous lignins can be used, including sulfate lignin, lignin sulfonic acid, lignin sulfonate, soda lignin, organic soluble lignin, burst lignin, sulfate lignin, alkali lignin, dealkalized lignin, and their derivatives, modifiers, and decomposition products. These lignins can be used alone or in combination of two or more.

[0059] The lignin-containing phenolic resin composition has a water content of 1.5% by mass or more and 6.5% by mass or less, preferably 1.5% by mass or more and 5.0% by mass or less. More preferably 1.5% by mass or more and 4.8% by mass or less, even more preferably 1.5% by mass or more and 4.2% by mass or less. Most preferably 4.0% by mass or less. If the water content is less than 1.5% by mass, the viscosity of the lignin-containing phenolic resin composition increases sharply, and the productivity decreases significantly. If the water content is greater than 6.5% by mass, foaming and curing are hindered by water, and the fine pores cannot be maintained, resulting in higher thermal conductivity.

[0060] There are no particular limitations on the method for adjusting the moisture content of lignin-containing phenolic resin compositions. For example, it can be appropriately done by using a thin-film evaporator for temperature control and vacuum control based on vapor pressure.

[0061] The moisture content of lignin added to the phenolic resin composition is 34.0% by mass or less, preferably 11.0% by mass or less, more preferably 7.0% by mass or less, further preferably 6.0% by mass or less, and most preferably 5.5% by mass or less. If it is greater than 34.0% by mass, more moisture diffuses from the lignin during foaming and curing, resulting in larger bubble diameters in the foam and increased thermal conductivity of the foam. Furthermore, if it is greater than 34.0% by mass, the viscosity is less likely to increase when mixing the lignin-containing phenolic resin composition, foaming agent, and acidic curing agent in the mixer, reducing the generation of shear heat in the mixer and delaying the foaming and curing time. If it is 34.0% by mass or less, the viscosity increases during mixing, generating shear heat in the mixer, preheating the lignin-containing phenolic resin composition, thereby reducing the curing reaction inhibition effect of lignin. Therefore, lignin-containing phenolic resin foams can be produced with the same foaming and curing time as lignin-free phenolic resin foams without compromising productivity.

[0062] There are no particular limitations on the method for adjusting the moisture content of lignin. For example, it can be done appropriately by heating or drying the lignin powder using a blower-cooled constant temperature dryer.

[0063] The median particle size of the lignin powder is preferably 0.1 μm or more and 300 μm or less, more preferably 0.1 μm or more and 250 μm or less, even more preferably 0.1 μm or more and 200 μm or less, and most preferably 0.1 μm or more and 150 μm or less. If the particle size is greater than 300 μm, the size of the lignin particles in the phenolic resin foam is significantly larger than the diameter of the foam bubbles, which easily damages the pores and leads to higher thermal conductivity.

[0064] There are no particular limitations on the method of pulverizing lignin powder. For example, methods such as using a rolling ball mill, rolling rod mill, vibrating ball mill, vibrating rod mill, disc mill, roller mill, and high-speed rotary mill can be cited.

[0065] The timing of lignin addition is not particularly limited; it can be supplied to the mixer containing the phenolic resin composition, foaming agent, and acid curing agent, and can be determined arbitrarily. When lignin is added downstream of the mixer, its dispersibility relative to the phenolic resin composition decreases, resulting in a phenolic resin foam with lignin locally present within the foam. When used as an insulation material, lignin functions as a thermal bridge, leading to increased thermal conductivity. Therefore, it is preferable to add lignin in a process upstream of the mixer containing the phenolic resin composition.

[0066] The amount of lignin added relative to 100 parts by weight of the phenolic resin composition is preferably 1.0% by weight or more and less than 30.0% by weight, more preferably 1.0% by weight or more and less than 25.0% by weight, more preferably 1.0% by weight or more and less than 12.0% by weight, and most preferably 1.0% by weight or more and less than 8.0% by weight. When the amount of lignin added is less than 1.0% by weight, the proportion of plant-derived materials in the phenolic resin foam is low, resulting in low value as a bio-based material. When the amount of lignin added exceeds 30.0% by weight, the proportion of lignin in the phenolic resin foam becomes high, and the viscosity increases when added to the phenolic resin, which is therefore undesirable. Furthermore, when used as an insulation material, lignin functions as a thermal bridge, leading to increased thermal conductivity.

[0067] As surfactants, surfactants commonly used in the manufacture of phenolic resin foams can be used, among which nonionic surfactants are effective, such as epoxides as copolymers of ethylene oxide and propylene oxide; and / or condensates of epoxides and castor oil; and / or condensates of epoxides and alkylphenols such as nonylphenol and dodecylphenol; and / or polyoxyethylene alkyl ethers with 14 to 22 carbon atoms in the alkyl ether moiety; further and / or fatty acid esters such as polyoxyethylene fatty acid esters; and / or organosilicon compounds such as polydimethylsiloxane; and / or polyols, etc. These surfactants can be used alone or in combination of two or more. In addition, there is no particular limitation on the amount used, but it is preferred to use 0.3 parts by weight or more and 10 parts by weight or less relative to 100 parts by weight of phenolic resin.

[0068] As a foaming agent, hydrofluoroolefins, hydrocarbons, and chlorinated hydrocarbons can be used alone, or in combination of two or more of them.

[0069] Hydrofluoroolefins typically have low thermal conductivity, and when used as blowing agents, they can produce phenolic resin foams with low thermal conductivity, making them preferred. Hydrofluoroolefins include chlorinated and non-chlorinated hydrofluoroolefins. In this invention, chlorinated and non-chlorinated hydrofluoroolefins can also be used in combination.

[0070] Examples of hydrofluoroolefins include: (Z)-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd(Z)), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), and, for example, Honeywell as the E-body (HCFO-1233zd(E)). Manufactured by Japan Co., Ltd., trade names: 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) The stereoisomers of these, namely the E-body or the Z-body, can be used, including 1-chloro-1,2,3-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-trifluoropropene (HCFO-1233yf), 1-chloro-1,3,3-trifluoropropene (HCFO-1233zb), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), etc. Furthermore, (E)-1-chloro-2,3,3,3-tetrafluoropropylene (HCFO-1224yd(E)) can also be listed. In this invention, two or more of these hydrofluoroolefins can also be used in combination.

[0071] Examples of non-chlorinated hydrofluoroolefins include: 1,3,3,3-tetrafluoro-1-propene (HFO-1234ze, for example, Honeywell as the E form (HFO-1234ze(E))). Products manufactured by Japan Co., Ltd. under the name Solstice (trademark) ze), 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz, for example, Opteon (trademark) 1100 manufactured by Chemours Co., Ltd. as the Z-body (HFO-1336mzz(Z)), 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-2-pentene (HFO-1438mzz), etc., can be used in their stereoisomers, namely, the E-body or the Z-body, or a mixture thereof. In this invention, two or more of these non-chlorinated hydrofluoroolefins can also be used in combination.

[0072] As hydrocarbons, cyclic or chain-like alkanes, alkenes, and alkynes with 3 to 7 carbon atoms are preferred. Specifically, examples include n-butane, isobutane, cyclobutane, n-pentane, isopentane, cyclopentane, neopentane, n-hexane, isohexane, 2,2-dimethylbutane, 2,3-dimethylbutane, and cyclohexane. Among these, pentanes such as n-pentane, isopentane, cyclopentane, and neopentane, and butanes such as n-butane, isobutane, and cyclobutane are preferred. In this invention, two or more of these hydrocarbons may also be used in mixture. Examples of mixtures include n-pentane and n-butane, isobutane and isopentane, n-butane and isopentane, isobutane and n-pentane, cyclopentane and n-butane, and cyclopentane and isobutane, etc., with mixtures of cyclopentane and isobutane being particularly preferred.

[0073] As chlorinated hydrocarbons, straight-chain or branched chlorinated aliphatic hydrocarbons with 2 to 5 carbon atoms are preferably used. The number of bonded chlorine atoms is preferably 1 to 4, and examples include dichloroethane, n-chloropropane, 2-chloropropane, chlorobutane, isochlorobutane, chloropentane, and isopentane. Among these, propyl chloride and 2-chloropropane, as chloropropanes, are more preferably used. In this invention, two or more of these chlorinated hydrocarbons may also be used in combination.

[0074] In addition, other foaming agents are not particularly limited, and examples include sodium bicarbonate, sodium carbonate, calcium carbonate, magnesium carbonate, azodicarbonamide, azobisisobutyronitrile, barium azodicarbonate, N,N'-dinitrospentamethylenetetramine, p,p'-oxobisbenzenesulfonylhydrazine, and trihydrazine triazine, among other chemical foaming agents. These foaming agents can be used alone or in combination of two or more.

[0075] The amount of foaming agent in the phenolic resin composition varies depending on the type of foaming agent, the compatibility between the foaming agent and the phenolic resin, the temperature, and the residence time, among other foaming and curing conditions. Therefore, it can be arbitrarily determined based on the desired density of the phenolic resin foam and the foaming conditions. The amount of foaming agent relative to 100 parts by weight of the phenolic resin composition is preferably 3.0 to 20 parts by weight, more preferably 4.0 to 18 parts by weight, further preferably 5.0 to 16 parts by weight, and most preferably 6.0 to 15 parts by weight. When the amount of foaming agent per 100 parts by weight of the phenolic resin composition is 3.0 parts by weight or more, it can suppress the high density of the resin foam. Furthermore, when the amount of foaming agent per 100 parts by weight of the phenolic resin composition is 20 parts by weight or less, it can suppress the decrease in mechanical strength, such as compressive strength, and / or the increase in thermal conductivity caused by the low density of the phenolic resin foam.

[0076] In this embodiment, a foaming nucleating agent can be used in the manufacture of phenolic resin foam. As a foaming nucleating agent, a gaseous foaming nucleating agent, such as nitrogen, helium, or argon, whose boiling point is more than 50°C lower than that of the foaming agent, can be added. Alternatively, solid foaming nucleating agents, such as inorganic powders like aluminum hydroxide powder, alumina powder, calcium carbonate powder, talc, kaolin, silica powder, silica sand, mica, calcium silicate powder, wollastonite, glass powder, glass beads, fly ash, silica fume, gypsum powder, borax, slag powder, alumina cement, and Portland cement, as well as organic powders like pulverized phenolic resin foam, can be added. These can be used individually or in combination of two or more without distinguishing between gaseous and solid forms. The timing of adding the foaming nucleating agent is arbitrary; it can be added to the mixer containing the phenolic resin composition.

[0077] When a gas foaming nucleating agent is added, the amount of the foaming agent is set to 100% by mass, and the amount added is preferably 0.2% by mass or more and 1.0% by mass or less, more preferably 0.3% by mass or more and 0.5% by mass or less.

[0078] The amount of solid foaming nucleating agent added relative to 100 parts by weight of the phenolic resin composition is preferably 3.0% by weight or more and 10.0% by weight or less, more preferably 3.0% by weight or more and 8.0% by weight or less. If the amount of solid foaming nucleating agent added is 3.0% by weight or more, it is easier to suppress the exudation of the foaming phenolic resin composition from the surface material. Furthermore, by keeping the amount of solid foaming nucleating agent added at 10.0% by weight or less, it is easier to suppress the diffusion of foaming agents with low boiling points.

[0079] The acidic curing agent can be any acidic curing agent capable of curing the phenolic resin composition, and contains an organic acid as the acid component. As the organic acid, aryl sulfonic acids or their anhydrides are preferred. Examples of aryl sulfonic acids and their anhydrides include toluenesulfonic acid, xylenesulfonic acid, phenolsulfonic acid, substituted phenolsulfonic acid, xylenephenolsulfonic acid, substituted xylenephenolsulfonic acid, dodecylbenzenesulfonic acid, benzenesulfonic acid, naphthalenesulfonic acid, etc., and their anhydrides; one or more can be used. It should be noted that in this embodiment, resorcinol, cresol, salicylol (o-hydroxymethylphenol), and p-hydroxymethylphenol can be added as curing aids. Furthermore, these acidic curing agents can be diluted with solvents such as ethylene glycol and diethylene glycol.

[0080] The amount of acid curing agent used varies depending on its type. When using a mixture of 80% by mass xylenesulfonic acid and 20% by mass diethylene glycol, it is preferable to use 6 or more and 20 or less of the mixture relative to 100 parts by mass of the phenolic resin composition, more preferably 8 or more and 15 or less of the mixture, and most preferably 11 or more and 13 or less of the mixture.

[0081] As the surface material for at least one of the sides and back of the phenolic resin foam, a flexible surface material is used. Preferably, the flexible surface material is a nonwoven or woven fabric whose main components are polyester, polypropylene, or nylon; kraft paper; glass fiber blended paper; calcium hydroxide paper; aluminum hydroxide paper; or magnesium silicate paper; or an inorganic fiber nonwoven fabric such as glass fiber nonwoven fabric. These can also be mixed (or laminated). When peeling the surface material from the obtained phenolic resin foam laminate and using only the base material, inexpensive paper that can be discarded after peeling is preferred. These surface materials are usually provided in roll form. Furthermore, materials compounded with additives such as flame retardants can also be used as flexible surface materials. It should be noted that there are no particular limitations on the bonding method between the surface material and the phenolic resin foam. Adhesives such as epoxy resin can be used. However, from the perspective of manufacturing cost and to avoid complicating the manufacturing process, it is preferable to use a method based solely on the fixing force of the foamed phenolic resin composition during thermosetting on the surface material.

[0082] <Manufacturing Method of Phenolic Resin Foam and its Laminated Board>

[0083] The method for manufacturing phenolic resin foam laminates employs a continuous manufacturing process comprising the following steps: a mixing step in which the aforementioned foamed phenolic resin composition is mixed using a mixer; a spraying step in which the mixed foamed phenolic resin composition is sprayed onto a lower surface material; and a foam laminate manufacturing step in which a phenolic resin foam laminate is manufactured from the foamed phenolic resin composition sprayed onto the lower surface material. Alternatively, an intermittent method using a mold frame to perform each step in stages can also be employed. It is also possible to use the phenolic resin foam without laminating the surface material or by removing the surface material.

[0084] In continuous manufacturing, a phenolic resin composition sprayed onto a lower surface material is covered with an upper surface material, and pre-formed uniformly from top to bottom while foaming and curing. Then, it is formally formed into a sheet while foaming and curing. In continuous manufacturing, methods for performing the pre-forming and / or formal forming processes include using a slatted double conveyor, using metal rollers or steel plates, and combinations thereof, among others, various methods corresponding to the manufacturing objective. For example, in the case of forming using a slatted double conveyor, the foamed phenolic resin composition covered with both upper and lower surface materials is continuously guided into the slatted double conveyor, heated, and pressure is applied from top to bottom to adjust to a predetermined thickness, while simultaneously foaming and curing to form a sheet. The temperature of the foamed phenolic resin composition sprayed onto the lower surface material depends on the boiling point of the foaming agent, and is generally preferably 32°C or higher and 45°C or lower. If the temperature of the foaming phenolic resin composition is above 32°C, it will easily foam in the initial stage, thus easily suppressing the leaching of the foaming phenolic resin composition from the underlying surface material. On the other hand, if the temperature of the foaming phenolic resin composition is below 45°C, diffusion will be easily suppressed even when using a foaming agent with a low boiling point, easily preventing the increase in thermal conductivity caused by a decrease in foaming efficiency and an increase in bubble diameter. It should be noted that the temperature of the foaming phenolic resin composition sprayed onto the underlying surface material can be adjusted by regulating the temperature and / or flow rate and rotation speed of the mixing machine used to mix various compositions.

[0085] <Preforming Process>

[0086] Ideally, the heating and temperature control conditions for the process of foaming and curing the foamable phenolic resin composition sprayed onto the lower surface material and preforming it from the upper surface material should be set to 30°C or higher and 80°C or lower. At 30°C or higher, it is easier to obtain a foaming-promoting effect in the preforming process and also promotes curing. Furthermore, at 80°C or lower, the area near the center in the thickness direction is less susceptible to internal heat release, the center temperature is less likely to rise, and thermal conductivity can be maintained for a longer period. When foaming and curing the foamable phenolic resin composition, in order to effectively promote curing while suppressing internal heat release near the center in the thickness direction, it is important to set up a formal forming process and a post-curing process after the preforming process, and to increase the temperature in stages. The dwell time in the preforming process is preferably 1 minute or more and 20 minutes or less.

[0087] <Formal Forming Process>

[0088] The heating and temperature control components for the formal forming process following the preforming process are preferably heated to a temperature of 65°C or higher and 100°C or lower. Within this range, a ring-type steel belt double conveyor, a slat-type double conveyor, or rollers can be used for formal forming. Furthermore, the dwell time in the formal forming process is the main process for foaming and curing reactions, and therefore is preferably 5 minutes or more and 40 minutes or less. A dwell time of 5 minutes or more can sufficiently promote foaming and curing. A dwell time of 2 hours or less can improve the production efficiency of phenolic resin foam laminates. It should be noted that when using conveyors, the temperature difference between the upper and lower conveyors is preferably less than 4°C.

[0089] Post-curing process

[0090] After being heated and temperature-controlled within the pre-forming and final forming processes, a post-curing process is applied. The preferred temperature for the post-curing process is 90°C or higher and 120°C or lower. At temperatures above 90°C, moisture in the foam diffuses easily; at temperatures below 120°C, the product's low thermal conductivity can be maintained for a longer period. By setting the temperature range for the post-curing process, moisture in the foamed phenolic resin composition can diffuse after final forming. The preferred dwell time for the post-curing process is 60 minutes or more and 300 minutes or less.

[0091] Example

[0092] The present invention will now be described in more detail through examples and comparative examples, but the present invention is not limited thereto.

[0093] Synthesis of Phenolic Resins

[0094] 3,500 kg of 52% formaldehyde aqueous solution (52% formalin) and 2,510 kg of 99% phenol (including water as an impurity) were added to the reactor. The mixture was stirred using a propeller-driven rotary mixer, and the internal liquid temperature was adjusted to 40°C using a temperature controller. Then, a 48% sodium hydroxide aqueous solution was added while the temperature was increased to carry out the reaction. The reaction proceeded until the Ostwald viscosity of the reaction solution reached 110 centistokes (=110 × 10⁻⁶). -6 m 2 During the stage of (measured at 25°C / s), the reaction solution was cooled and 398 kg of urea was added. Then, the reaction solution was cooled to 30°C, and the pH was neutralized to 6.4 with a 50% by mass aqueous solution of p-toluenesulfonic acid monohydrate.

[0095] The reaction solution was concentrated at 60°C to obtain phenolic resin. It should be noted that the mass-average molecular weight and viscosity at 40°C of the phenolic resin were determined using the following methods: mass-average molecular weight was 500, viscosity at 40°C was 9,730 mPa·s, and water content was 4.0% by mass.

[0096] <weight-average molecular weight of phenolic resin>

[0097] The mass-average molecular weight (Mw) of the phenolic resin was determined by gel permeation chromatography (GPC) under the following conditions, based on a standard curve obtained from the standard substances (standard polystyrene, 2-hydroxybenzyl alcohol, and phenol) shown below.

[0098] Preprocessing:

[0099] Dissolve approximately 10 mg of phenolic resin in 1 ml of N,N-dimethylformamide (manufactured by Fujifilm and Koichi Chemical Co., Ltd., for high performance liquid chromatography), and filter the solution through a 0.2 μm membrane filter to obtain the assay solution.

[0100] Measurement conditions:

[0101] Measurement device: Shodex System21 (manufactured by Showa Denko Corporation)

[0102] Column: Shodex Asahipak GF-310HQ (7.5mmI.D.×30cm)

[0103] Eluent: Lithium bromide 0.1% by mass is dissolved in N,N-dimethylformamide (manufactured by Fujifilm and Koichi Pure Chemicals Co., Ltd., for high performance liquid chromatography) and used.

[0104] Flow rate: 0.6 ml / min

[0105] Detector: RI detector

[0106] Column temperature: 40℃

[0107] Standard substances: Standard polystyrene (Shodex standard SL-105 manufactured by Showa Denko Corporation), 2-hydroxybenzyl alcohol (Sigma-Aldrich, 99% purity), phenol (Kanto Chemical Co., Ltd., premium grade).

[0108] <Viscosity Measurement of Phenolic Resins>

[0109] The viscosity of the phenolic resin was determined using a rotational viscometer (Brookfield Metek, DVNXHBCBG type, rotor CPA-52Z) after stabilizing 0.5 ml of phenolic resin at 40°C for 6 minutes.

[0110] (Example 1)

[0111] A composition was prepared by mixing 3.0 parts by weight of a mixture relative to 100 parts by weight of phenolic resin. This composition contained 50% by weight each of an ethylene oxide-propylene oxide block copolymer and polyoxyethylene dodecyl phenyl ether as surfactants. This was used as the phenolic resin composition. As lignin, 8.0% by weight of lignin (de-alkaliened) obtained by the sulfite process (manufactured by Tokyo Chemical Industry Co., Ltd.), with a median particle size of 25.7 μm and a moisture content of 10.2% by weight, was added relative to 100 parts by weight of the phenolic resin composition containing the above surfactant. This lignin was concentrated using a thin-film evaporator, resulting in a moisture content of 4.20% by weight. In addition, relative to 100 parts by weight of the lignin-containing phenolic resin composition described above, 13 parts by weight of a composition formed by a mixture of 70% by weight of cyclopentane and 30% by weight of isobutane as a foaming agent, 0.4% by weight of nitrogen as a gas foaming nucleating agent relative to the foaming agent, and 13 parts by weight of a composition formed by a mixture of 80% by weight of xylenesulfonic acid and 20% by weight of diethylene glycol as an acidic curing agent are added and supplied to a variable speed mixing head with a temperature controlled at 17°C. The lignin is compounded with the phenolic resin composition using a twin-screw extruder before the addition of the foaming agent and acidic curing agent. Then, the gas foaming nucleating agent, foaming agent, and acidic curing agent are mixed using a mixer, and the resulting foamed phenolic resin composition is distributed using a multi-channel distribution pipe and supplied to a moving lower surface material. It should be noted that the mixer used is the one disclosed in Figure 1 of Japanese Patent Application Publication No. 10-225993. That is, a mixer is used in which the inlet of the lignin-containing phenolic resin composition and the inlet of the foaming agent are arranged adjacent to each other on the upper side of the mixer, and the inlet of the acid curing agent is provided on the side near the center of the stirring section where the rotor stirs. The stirring section and the section thereafter are connected to nozzles for spraying the foaming phenolic resin composition. That is, in the mixer, the section up to the acid curing agent inlet is defined as the mixing section (front section), the section from the acid curing agent inlet to the end of the stirring is defined as the mixing section (rear section), and the section from the end of the stirring to the nozzles is defined as the distribution section. The distribution section has multiple nozzles at the front end and is designed to uniformly distribute the mixed foaming phenolic resin composition. Moreover, the distribution section has a jacketed structure, which allows for sufficient heat exchange using temperature-controlled water, and the temperature of the temperature-controlled water in the distribution section is set to 17°C. In addition, thermocouples are provided at the nozzles of the multi-channel distribution pipe to detect the temperature of the foaming phenolic resin composition, and the speed of the mixer is set to 500 rpm. The temperature of the foamed phenolic resin composition sprayed onto the lower surface material at this time is 34°C.The foamed phenolic resin composition supplied to the lower surface material is introduced into a preforming process at a temperature of 40°C. After 30 seconds, it is preformed from above the upper surface material using a free roller. The dwell time for this process is set to 5 minutes. Then, it is introduced into a slatted double conveyor heated to 69°C (formal forming process) by being sandwiched between two surface materials. After curing for 15 minutes, it is then cured at 100°C for 9 minutes and then at 110°C for 2 hours (post-curing process) to obtain the phenolic resin foam laminate of Example 1 with a thickness of approximately 30 mm. It should be noted that, as the surface material, both the upper and lower surface materials use polyester nonwoven fabric (Asahi Kasei Corporation ELTAS E05060, with a unit area weight of 60 g / m²). 2 This manufacturing method is represented in Table 2 as Manufacturing Method A. It should be noted that the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material is the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0112] The properties of the lignin powder used were evaluated using the following methods.

[0113] <Determination of Median Particle Size of Lignin Powder>

[0114] The median particle size of the lignin powder was determined using a particle size distribution measuring device based on laser diffraction light scattering (Made by Nikkiso Corporation, Microtrac HRA; 9320-X100). To ensure uniform dispersion of the lignin powder in water, it was measured after ultrasonic treatment for 1 minute.

[0115] <Determination of Moisture Content in Lignin Powder>

[0116] The moisture content of lignin powder was calculated using a moisture meter (Shimadzu Corporation, MOC63u) by heating 0.5g of the powder at 120°C for 20 minutes, as shown in the following formula, by dividing the difference between the mass before heating and the mass after heating, M(g), by the mass before heating.

[0117] Moisture content (mass %) = (0.5 - M) / (0.5) × 100

[0118] The properties of the phenolic resin compositions used and the lignin-containing phenolic resin compositions were evaluated using the following methods.

[0119] <Determination of Moisture Content in Phenolic Resin Compositions and Lignin-Containing Phenolic Resin Compositions>

[0120] The moisture content of the phenolic resin composition and the lignin-containing phenolic resin composition was determined using a Karl Fischer moisture meter (Kyoto Electron Industries, Ltd., MKV-710) by volumetric titration. The Karl Fischer reagent used was KEMAQUA titrant TR-3 (Kyoto Electron Industries, Ltd.), and the dehydrating solvent used was KEMAQUA dehydrating solvent MET (Kyoto Electron Industries, Ltd.).

[0121] The characteristics of the obtained phenolic resin foam and phenolic resin foam laminate were evaluated by the following methods: identification of lignin content in phenolic resin foam, determination of density, determination of thermal conductivity of phenolic resin foam laminate at 23℃, determination of average bubble diameter of phenolic resin foam, and identification of foaming agent type in phenolic resin foam.

[0122] Identification of Lignin Components in Phenolic Resin Foam

[0123] Phenolic resin foam laminates were used as samples. After removing the surface material from the samples, pyrolysis gas chromatography-mass spectrometry analysis was performed under the following determination and analysis conditions to identify the lignin components present in the phenolic resin foam.

[0124] <Pyrolysis Gas Chromatography-Mass Spectrometry (GC-MS) Analysis Conditions>

[0125] GC device: Agilent Technologies 7890B

[0126] Column: DB1 (30m, 0.25mm φ, liquid phase thickness 0.25μm)

[0127] Column temperature: 40℃ (5 min) → (10℃ / min increase) → 320℃ (hold for 12 min)

[0128] Flow rate: 1 ml / min constant flow rate

[0129] Inlet temperature: 300℃

[0130] Injection method: shunt method (shunt ratio 100:1)

[0131] MS device: JEOL RESONANCE, JMS-Q1500GC

[0132] Interface temperature: 300℃

[0133] Ionization method: EI (electron ionization) method 70 eV (temperature 230℃)

[0134] Pyrolysis apparatus: Frontier-lab EGA / PY-3030D

[0135] Pyrolysis temperature: 600℃ (under He atmosphere)

[0136] Scan range: m / z 10~800

[0137] Sample amount: 1 mg

[0138] In gas chromatography-mass spectrometry (GC-MS) analysis, with the retention time for phenol detection in the obtained total ion chromatogram set as t minutes, pyrolysis products derived from dihydroxybenzene were detected near a retention time of 1.38 × t minutes in the extract ion chromatogram at m / z=110; pyrolysis products derived from dihydroxytoluene were detected near a retention time of 1.46 × t minutes and near a retention time of 1.50 × t minutes in the extract ion chromatogram at m / z=138; and pyrolysis products derived from dihydroxyxylene were detected near a retention time of 1.58 × t minutes in the extract ion chromatogram at m / z=138. It should be noted that, using the above-described pyrolysis GC-MS analysis method, phenol was detected near a retention time of 10.0 minutes.

[0139] In the ion chromatograms of the obtained pyrolysis products, the area of ​​the pyrolysis product derived from dihydroxybenzene detected near a retention time of 1.38 × t minutes in the extract ion chromatogram at m / z=110 is designated as A; the sum of the areas of the pyrolysis products derived from dihydroxytoluene detected near a retention time of 1.46 × t minutes and the areas of the pyrolysis products derived from dihydroxytoluene detected near a retention time of 1.50 × t minutes in the extract ion chromatogram at m / z=124 is designated as B; the area of ​​the pyrolysis products derived from dihydroxyxylene detected near a retention time of 1.58 × t minutes in the extract ion chromatogram at m / z=138 is designated as C; and the sum of A, B, and C is designated as X (X=A+B+C). Furthermore, for peak 9 in [Figure 1] of Japanese Patent No. 4711469, when the area of ​​the pyrolysis product representing the urea crosslinking structure detected near a retention time of 1.50 × t minutes in the total ion chromatogram is designated as Y, its ratio to X is designated as Z (Z=X / Y). In addition, the areas A, B, C, and Y are calculated with the intersection with the baseline or the inflection point of the adjacent peak as the boundary.

[0140] Determination of the density of phenolic resin foam

[0141] A 200mm square phenolic resin foam laminate was used as the sample. After removing the surface material from the sample, the mass and apparent volume were determined according to JIS K7222.

[0142] <Determination of thermal conductivity of phenolic resin foam laminate at 23℃>

[0143] According to JIS A 1412-2:1999, the thermal conductivity in the thickness direction of resin foam laminates at 23°C was determined by the following method. The specific procedure is described below.

[0144] Phenolic resin foam laminates were cut into 300mm squares, and the test pieces were placed in an atmosphere of 23±1℃ / 50±2% humidity. The weight change over time was measured every 24 hours to confirm and adjust the condition until the weight change after 24 hours was less than 0.2% by mass. The condition-adjusted phenolic resin foam laminate test pieces were then introduced into a thermal conductivity measuring device, which was similarly placed in an atmosphere of 23±1℃ / 50±2% humidity. Without placing the thermal conductivity measuring device in a room containing the phenolic resin foam laminate test pieces and maintaining a humidity level of 23±1% / 50±2%, the test pieces, after condition confirmation and adjustment in the aforementioned atmosphere, were quickly placed in a polyethylene bag and the bag was closed. The bags were then removed within one hour, and the thermal conductivity was quickly measured.

[0145] Thermal conductivity was measured using a measuring apparatus (Eihong Precision Machinery Co., Ltd., trade name "HC-074 / FOX304") with a single sample and object configuration under the conditions of 13°C for the low-temperature plate and 33°C for the high-temperature plate.

[0146] <Determination of the average bubble diameter of phenolic resin foam>

[0147] The average bubble diameter was determined by the following method. A phenolic resin foam laminate was used as a sample. After removing the surface material from the sample, four images were taken using a scanning electron microscope at 50x magnification for bubbles located approximately at the center of the phenolic resin foam along its thickness direction and approximately at the center relative to the surface and back surfaces. Four straight lines of 90 mm length (equivalent to 1,800 μm in the actual cross-section of the foam) were drawn on the images, avoiding gaps. The number of bubbles measured based on the number of bubbles transverse to each line was determined. The average bubble diameter was obtained by dividing the average of these lines by 1,800 μm.

[0148] <Identification of the types of foaming agents in phenolic resin foam>

[0149] First, using standard gases of halogenated hydrocarbons and hydrocarbons, the retention times under the following GC / MS determination conditions were determined.

[0150] A phenolic resin foam laminate was used as the sample. After removing the surface material from the sample, a 0.25 mg sample was cut from near the center of the foam and placed in a special container. 10 ml of chloroform and 12 crushed glass beads were added. While homogenizing the sample using an IKA ULTRA-TURRAX Tube Drive at 6000 rpm for 7–11 min, the components were extracted in chloroform. The extract was then filtered through a 0.45 μm filter for GC / MS analysis. A standard sample solution of known concentration was prepared by dissolving the target component in chloroform and analyzed under the same conditions as the sample.

[0151] Halogenated hydrocarbons and hydrocarbons were identified by pre-determined retention times and mass spectrometry. Additionally, the detection sensitivity of the generated gas components was determined using standard gases, and the content of each substance was calculated based on the detection area and sensitivity of each gas component obtained by GC / MS. Based on the identified gas component content, the foaming agent content, and the molar mass, the mass percentage of each foaming agent component in the phenolic resin foam was calculated.

[0152] (Example 2)

[0153] The lignin was replaced with lignin (alkali) obtained by the sulfite process (manufactured by Tokyo Chemical Industry Co., Ltd.) with a median particle size of 26.8 μm and a moisture content of 5.3% by mass. Otherwise, the phenolic resin foam laminate of Example 2 was manufactured in the same manner as in Example 1. It should be noted that the concentrated lignin-containing phenolic resin composition had a moisture content of 3.85% by mass. Furthermore, the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0154] (Example 3)

[0155] The lignin was not pulverized, and instead, sodium lignin sulfonate with a median particle size of 238.5 μm and a moisture content of 5.0% by mass was used. Otherwise, the phenolic resin foam laminate of Example 3 was manufactured in the same manner as in Example 1. It should be noted that the concentrated lignin-containing phenolic resin composition had a moisture content of 3.83% by mass. Furthermore, the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0156] (Example 4)

[0157] The lignin was replaced with sulfate lignin with a median particle size of 23.9 μm and a moisture content of 6.5% by mass. Otherwise, the phenolic resin foam laminate of Example 4 was manufactured in the same manner as in Example 1. It should be noted that the concentrated lignin-containing phenolic resin composition had a moisture content of 3.93% by mass. Furthermore, the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0158] (Example 5)

[0159] The amount of lignin added relative to 100 parts by weight of the phenolic resin composition was set to 1.0% by weight. Otherwise, the phenolic resin foam laminate of Example 5 was manufactured in the same manner as in Example 1. It should be noted that the water content of the concentrated lignin-containing phenolic resin composition was 3.80% by weight. In addition, the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0160] (Example 6)

[0161] The amount of lignin added relative to 100 parts by weight of the phenolic resin composition was set to 12.0% by weight. Otherwise, the phenolic resin foam laminate of Example 6 was manufactured in the same manner as in Example 1. It should be noted that the water content of the concentrated lignin-containing phenolic resin composition was 4.40% by weight. In addition, the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0162] (Example 7)

[0163] The amount of lignin added relative to 100 parts by weight of the phenolic resin composition was set to 20.0% by weight. Otherwise, the phenolic resin foam laminate of Example 7 was manufactured in the same manner as in Example 1. It should be noted that the concentrated lignin-containing phenolic resin composition had a moisture content of 4.78% by weight. Furthermore, the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0164] (Example 8)

[0165] The amount of lignin added relative to 100 parts by weight of the phenolic resin composition was set to 25.0% by weight. Otherwise, the phenolic resin foam laminate of Example 8 was manufactured in the same manner as in Example 1. It should be noted that the water content of the concentrated lignin-containing phenolic resin composition was 4.99% by weight. In addition, the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0166] (Example 9)

[0167] The amount of lignin added relative to 100 parts by weight of the phenolic resin composition was set to 29.0% by weight. Otherwise, the phenolic resin foam laminate of Example 9 was manufactured in the same manner as in Example 1. It should be noted that the concentrated lignin-containing phenolic resin composition had a moisture content of 5.15% by weight. Furthermore, the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0168] (Example 10)

[0169] The lignin was replaced with sulfate lignin with a median particle size of 23.9 μm and a moisture content of 6.5% by mass, so that the amount of lignin added relative to 100 parts by mass of the phenolic resin composition was 29.0% by mass. Otherwise, the phenolic resin foam laminate of Example 10 was manufactured in the same manner as in Example 1. It should be noted that the moisture content of the concentrated lignin-containing phenolic resin composition was 4.33% by mass. In addition, the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0170] (Example 11)

[0171] 2.7% by weight of water was added relative to 100 parts by weight of the phenolic resin composition containing a surfactant, and the water content of the concentrated lignin-containing phenolic resin composition was set to 6.50% by weight. Otherwise, the phenolic resin foam laminate of Example 11 was manufactured in the same manner as in Example 1. It should be noted that the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0172] (Example 12)

[0173] Except that the foaming agent was (Z)-1-chloro-2,3,3,3-tetrafluoropropylene (HCFO-1224yd(Z)), the phenolic resin foam laminate of Example 12 was manufactured in the same manner as in Example 1. It should be noted that the concentrated lignin-containing phenolic resin composition had a moisture content of 4.20% by mass. Furthermore, the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was the same as that of the lignin-free foamed phenolic resin composition (Comparative Example 1 described later).

[0174] (Example 13)

[0175] A composition was prepared by mixing 3.0 parts by mass relative to 100 parts by mass of phenolic resin. This composition contained 50% by mass each of an ethylene oxide-propylene oxide block copolymer and polyoxyethylene dodecyl phenyl ether as surfactants. This was used as the phenolic resin composition. As lignin, lignin (de-alkali treated) obtained by the sulfite process (manufactured by Tokyo Chemical Industry Co., Ltd.), which had been pre-dried at 120°C for 20 minutes in a constant-temperature air-blown dryer and then pulverized, with a median particle size of 25.7 μm and a moisture content of 10.2% by mass, was placed in plastic cups and mixed using a stirring rod mounted on a Hi-Koki DS10DAL wireless drill. This was used as the lignin-containing phenolic resin composition. The lignin-containing phenolic resin composition was concentrated using a thin-film evaporator, resulting in a moisture content of 4.20% by mass. In addition, the foaming agent n-pentane was mixed using a wireless drill, with 12 parts by mass relative to 100 parts by mass of the aforementioned lignin-containing phenolic resin composition. Although no gas-blowing nucleating agent was added, the air entrained during mixing acted as a nucleating agent. The weight change of the resin composition confirmed that specific amounts could be mixed separately. Next, the plastic cup containing the foaming phenolic resin composition was cooled in a refrigerator for 1 hour. After confirming that the foaming phenolic resin composition was below 12°C, 13 parts by mass of a mixture of 80% by mass xylenesulfonic acid and 20% by mass diethylene glycol was added as an acidic curing agent, and the mixture was mixed using a wireless drill for 2 minutes. Then, the foaming phenolic resin composition was applied to the bottom surface of a metal frame (mold frame) using a scraper at 23°C. The amount of foaming phenolic resin composition applied was adjusted appropriately so that the foamed thickness did not protrude from the metal frame (mold frame). The metal frame (mold frame) used here is made of 2.0mm thick metal, with an inner diameter of 300mm × 300mm × height of 30mm. The bottom surface has 5mm diameter holes punched at 1mm intervals, and a polyester nonwoven fabric (Asahi Kasei Corporation, ELTAS E05060, 60g / m²) is laid on the bottom surface.2 The surface material was used as the top plate. The working time from mixing the foaming phenolic resin composition and the acidic curing agent until the end of the coating process was set to 5 minutes. Then, as the top plate, the same surface material as the bottom surface of the metal frame (mold frame) was pasted onto a plate with the same perforation size as the bottom surface (greater than 300mm × 300mm), and covered with the surface material facing the foaming phenolic resin side. The top plate was fixed to the metal frame (mold frame) using clips. The metal frame (mold frame) was placed in an oven heated to 85°C, and a 25kg weight heated to 85°C was placed in the center of the top plate of the metal frame (mold frame). After heating for 1 hour, it was further cured at 105°C for 1 hour to obtain the phenolic resin foam laminate of Example 13 with a thickness of 30mm. This manufacturing method is shown in Table 2 as Manufacturing Method B. It should be noted that the foaming and curing speed of the lignin-containing foamed phenolic resin composition coated on the lower surface material (Comparative Example 1 described later) is the same as that of the lignin-free foamed phenolic resin composition.

[0176] (Comparative Example 1)

[0177] Lignin was not incorporated into the phenolic resin composition. Otherwise, the phenolic resin foam laminate of Comparative Example 1 was manufactured in the same manner as in Example 1. It should be noted that the moisture content of the phenolic resin composition was 3.73% by mass. Furthermore, the foaming and curing speed of the foamed phenolic resin composition supplied to the lower surface material was such that, based on industrially manufactured phenolic resin foam, a fully cured foam laminate was obtained that maintained sufficient productivity.

[0178] (Comparative Example 2)

[0179] The lignin was not dried; instead, it was replaced with sulfate lignin with a median particle size of 23.7 μm and a moisture content of 34.6% by mass. Otherwise, the phenolic resin foam laminate of Comparative Example 2 was manufactured exactly the same as in Example 1. It should be noted that the concentrated lignin-containing phenolic resin composition had a moisture content of 5.94% by mass. Furthermore, the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was lower than that of the lignin-free foamed phenolic resin composition (Comparative Example 1), resulting in an under-cured foam. Therefore, by further curing at 110°C for 4 hours after the post-curing process, a fully cured foam was obtained.

[0180] (Comparative Example 3)

[0181] 13.7% by weight of water was added relative to 100 parts by weight of the phenolic resin composition containing a surfactant, and the water content of the concentrated lignin-containing phenolic resin composition was set to 15.70% by weight. Otherwise, the phenolic resin foam laminate of Comparative Example 3 was manufactured exactly the same as in Example 1. It should be noted that the foaming and curing speed of the lignin-containing foamed phenolic resin composition supplied to the lower surface material was lower than that of the lignin-free foamed phenolic resin composition (Comparative Example 1), resulting in an under-cured foam. Therefore, by further curing at 110°C for 4 hours after the post-curing process, a fully cured foam was obtained.

[0182] The types of lignin used in Examples 1-13 and Comparative Examples 2-3 are shown in Table 1. Furthermore, the above-described determination and evaluation tests were performed on Examples 1-13 and Comparative Examples 1-3. The determination and evaluation results are shown in Tables 2 and 3.

[0183] [Table 1]

[0184]

[0185] [Table 2]

[0186]

[0187] [Table 3]

[0188]

[0189] Industrial availability

[0190] The phenolic resin foam of the present invention, by appropriately adjusting the moisture content of the phenolic resin composition containing lignin, enables the maintenance of foaming and curing time and allows for production without reducing productivity, even in lignin-containing phenolic resin foams. Furthermore, it suppresses foaming obstacles caused by water, and by maintaining fine pores, it maintains thermal conductivity and insulation properties even in lignin-containing phenolic resin foams. Additionally, by pulverizing lignin powder and adding finely milled lignin, it reduces the damage to pores caused by coarse lignin particles, maintaining fine pores and thus maintaining thermal conductivity and insulation properties even in lignin-containing phenolic resin foams. Moreover, by using plant-derived materials, a bio-based phenolic resin foam can be provided.

Claims

1. A phenolic resin foam, wherein in the ion chromatogram of the gaseous components generated by heating at 600°C, obtained by gas chromatography-mass spectrometry analysis, the area ratio Z (Z=X / Y) of the sum of the areas A (derived from the pyrolysis product dihydroxybenzene), B (derived from dihydroxytoluene), and C (derived from dihydroxyxylene) to the area Y (derived from the pyrolysis product representing the urea crosslinking structure) is within the range of the following formula (1), and the thermal conductivity of the phenolic resin foam at 23°C is 0.0240 W / (m·K) or less. 0.035≤Z≤0.715 (1)。 2. The phenolic resin foam according to claim 1, wherein the density is 10 kg / m³. 3 Above and 50kg / m 3 the following.

3. The phenolic resin foam according to claim 1 or 2, wherein the average bubble diameter is 70 μm or more and 250 μm or less.

4. The phenolic resin foam according to claim 1 or 2, wherein it comprises any one of hydrofluoroolefins, hydrocarbons, and chlorinated hydrocarbons.

5. The phenolic resin foam according to claim 1 or 2, wherein, At least one of the sides of the phenolic resin foam has a surface material.

6. A method for manufacturing a phenolic resin foam laminate, comprising foaming and curing a foamable phenolic resin composition. The manufacturing method for obtaining the foamed phenolic resin composition includes at least one of the following steps: adding lignin to phenols; adding lignin during the synthesis of phenolic resin; adding lignin to the phenolic resin; and adding lignin to the phenolic resin composition. The lignin has a moisture content of less than 34.0%. The lignin-containing phenolic resin composition in the foamed phenolic resin composition has a water content of 1.5% by mass or more and 6.5% by mass or less.

7. The manufacturing method according to claim 6, wherein, In the process of adding lignin, the median particle size of the added lignin powder is 0.1 μm or more and 300 μm or less.

Images