JP7584764B2 - Foam Laminate - Google Patents

Description

The present invention relates to a foam laminate consisting of soft urethane foam and phenol foam.

Phenolic foam has high insulation, flame retardancy, and heat resistance among foamed plastic insulation materials, and is therefore widely used as a building material and general industrial material. On the other hand, phenolic foam, which has high insulation performance, does not have sufficient cushioning properties, is not very resistant to impact, and does not have sufficient sound absorption properties. In recent years, as phenolic foam has become more widely used from the perspective of energy conservation, there has been a demand for foam laminates that take advantage of the characteristics of phenolic foam while also having excellent cushioning properties, impact resistance, sound absorption, and repeated compression properties (residual compression after repeated compression; reduced settling).

In this environment, many improvements have been made to phenolic foam, but it has not yet been possible to give it excellent cushioning, impact resistance, and repeated compression characteristics (residual compression after repeated compression; reduced settling) while also providing its greatest characteristic, high insulation performance.

For example, Patent Documents 1 and 2 attempt to give phenol foam the characteristics of cushioning and impact resistance.

However, the technologies of both Patent Document 1 and Patent Document 2 were inferior in the insulation performance (thermal conductivity) of the phenol foam core material and the laminate, and furthermore, had insufficient repeated compression characteristics.

Japanese Unexamined Patent Publication No. 60-53930 Japanese Patent Application Publication No. 55-92451

The objective of the present invention is to provide a foam laminate that has the high thermal insulation performance of phenolic foam while also having excellent compression properties.

That is, the present invention is as follows.

[1] A foam laminate in which at least a portion of the periphery of a phenol foam is covered with a soft urethane foam,
The density of the phenol foam is 20 kg/m3 ^or more and 80 kg/m3 ^or less,
The phenol foam has a closed cell rate of 85% or more;
The density of the flexible urethane foam is 35 kg/m3 ^or more and 420 kg/m3 ^or less.
[2] The foam laminate described in [1], wherein the soft urethane foam is provided only on both surfaces of the phenol foam in the thickness direction.
[3] The foam laminate according to [1] or [2], wherein the thermal conductivity of the foam laminate at 23°C is 0.026 W/(m·K) or less.
[4] The foam laminate according to any one of [1] to [3], wherein the flexible urethane foam is a ribbon dead foam.
[5] The foamed laminate according to any one of [1] to [4], wherein the phenol foam consists of a plurality of phenol foam pieces.

The present invention makes it possible to provide a foam laminate that has excellent compression properties while taking advantage of the high thermal insulation performance of phenolic foam.

1A is a schematic diagram of a foam laminate produced in Example 1, and FIG. 1B is an exploded perspective view thereof. FIG. 1A is a schematic diagram of a foam laminate produced in Example 6, and FIG. 1B is an exploded perspective view thereof.

The present invention has discovered a foam laminate that combines excellent compression properties (particularly repeated compression properties (residual compression after repeated compression; reduced settling)) that were not previously possible, by covering the phenol foam with urethane foam that has cushioning properties and impact resistance.

The following provides a detailed explanation of the embodiment of the present invention (hereinafter referred to as the "present embodiment").

In this embodiment, the density of the phenol foam, the closed cell ratio of the phenol foam, the density of the soft urethane foam, and the thermal conductivity of the foam laminate are determined by the method described in the examples.

The phenol foam of this embodiment is produced by adding a foaming agent, an acidic curing agent containing an organic acid, and the like to a "phenolic resin composition" made by adding a surfactant to a "phenolic resin" to give it foamability and curing properties, and then feeding the "foamable phenolic resin composition" into a mixer, mixing the "foamable phenolic resin composition" and discharging it from the mixer, and foaming and curing it under heat. Note that if a surface material, siding, or the like is attached, the portion made of phenolic resin excluding these is defined as "phenolic foam".

The density of the phenol foam of this embodiment is 20 kg/m ³ or more and 80 kg/m ³ or less, preferably 35 kg/m ³ or more and 70 kg/m ³ or less, more preferably 45 kg/m ³ or more and 65 kg/m ³ or less. If the density of the phenol foam is 20 kg/m ³ or more, mechanical strength such as compressive strength and bending strength can be ensured, and breakage during handling of the foam board can be avoided. On the other hand, if the density of the phenol foam is 80 kg/m ³ or less, the heat transfer of the resin part is unlikely to increase, so that the heat insulating performance can be maintained. The density of the phenol foam can be adjusted to a desired value mainly by changing the ratio of the foaming agent, the temperature of the foamable phenolic resin composition, the timing of preforming in the process of discharging the mixed foamable phenolic resin composition onto the lower surface material, and further the ratio of the amount of the foaming agent to the amount of the organic acid used as the acidic curing agent, and the curing conditions such as temperature and residence time.

The closed cell rate of the phenol foam of this embodiment is 85% or more, and preferably 90% or more. The closed cell rate is an indicator of thermal insulation performance, so a rate of 85% or more is preferable because it provides good thermal insulation performance.

The closed cell ratio can be adjusted to the desired value mainly by adjusting the reactivity and temperature of the phenolic resin, as well as by changing the curing temperature conditions.

The shape of the phenol foam is not particularly limited and can be any shape. Examples of the shape of the phenol foam include a rectangular parallelepiped (e.g., a plate, layer, sheet, etc.), a polyhedron other than a rectangular parallelepiped (e.g., a regular polyhedron such as a regular tetrahedron, a regular octahedron, a regular dodecahedron, a regular icosahedron, etc.), a sphere, a pyramid, a cone, a torus, a hollow cylinder, a solid cylinder (cylinder), and an amorphous shape. In one embodiment, the phenol foam is a rectangular parallelepiped.

In this embodiment, the phenolic foam can be used in combination with multiple phenolic foam pieces, in addition to being used as an integrally molded product. The phenolic foam piece has a main surface with short and long sides each measuring 5 to 2000 mm. In particular, it is preferable to actively use multiple phenolic foam scraps as the phenolic foam pieces in order to reduce the environmental load. The number of phenolic foam pieces in the foamed laminate can be confirmed by removing the soft polyurethane foam on the surface of the foamed laminate.

In the foam laminate of this embodiment, at least a portion of the phenol foam is covered with soft urethane foam. This makes it possible to obtain a foam laminate that utilizes not only the high insulation performance, flame retardancy, and heat resistance that are characteristic of phenol foam, but also the cushioning properties that are characteristic of soft urethane foam, and that combines cushioning properties, impact resistance, and compression properties (particularly repeated compression properties (residual compression after repeated compression; reduced settling)) that have not been possible until now. In addition, the foam laminate of this embodiment also exhibits excellent sound absorption properties due to the high density of the soft urethane foam.

In the foamed laminate of this embodiment, at least a portion of the periphery of the phenolic foam may be covered with soft urethane foam. For example, the foamed laminate may have soft urethane foam only on the two opposing surfaces (surfaces here include surfaces other than the main surface) of the plate-shaped phenolic foam, or only on both surfaces (main surfaces) in the thickness direction of the plate-shaped phenolic foam, or on one or more side surfaces or the entire surface of the plate-shaped phenolic foam in addition to both surfaces (main surfaces) in the thickness direction of the plate-shaped phenolic foam. The thickness direction refers to the direction with the smallest dimension of the rectangular parallelepiped.

In addition, the foam laminate of this embodiment has soft urethane foam only on both sides of the thickness of the plate-shaped phenolic foam, so that the phenolic foam functions as a surface for heat conduction in the thickness direction, making it possible to take advantage of the high thermal insulation performance of the phenolic foam in particular.

When soft urethane foam is provided only on both surfaces in the thickness direction of the plate-shaped phenolic foam, the ratio of the thickness of the phenolic foam to the thickness of the soft urethane foam (upper and lower layers combined) can be any ratio between 5:95 and 95:5. When taking advantage of the properties of the phenolic foam, such as heat insulation, flame retardancy, and heat resistance, it is preferable to increase the thickness ratio of the phenolic foam, and when prioritizing cushioning, impact resistance, sound absorption, and further compression characteristics (especially repeated compression characteristics (residual compression after repeated compression; reduced settling)), it is preferable to increase the thickness of the soft urethane foam. The thickness ratio of the soft urethane foam in the upper and lower layers is generally the same because the front and back are often used without distinction when using the foam laminate, but the ratio may be changed as appropriate.

A flexible polyurethane foam is a foam obtained by mixing a blowing agent, a foam stabilizer, a catalyst, a colorant, etc., with polyol and polyisocyanate as main components, and foaming the mixture while resinifying it. The flexible polyurethane foam has interconnected cells, is soft, and has good restorability. It has an open cell structure, is highly breathable, and is reversibly deformable [see, for example, Gunter Oertel, "Polyurethane Handbook" (1985 edition), Hanser Publishers (Germany), pp. 161-233; Keiji Iwata, "Polyurethane Resin Handbook" (first edition, 1987), Nikkan Kogyo Shimbun, pp. 150-221].
The flexible urethane foam may be either or a combination of "polyether foam" and "polyester foam".

To reduce the environmental impact, it is preferable to use recycled soft urethane foam, that is, so-called rebonded foam, which is made by crushing waste and scraps of polyurethane resin products and bonding the chips together with a binder (disclosed in JP-A-09-066527, [0015], etc.).

When using a rebonded foam as the soft urethane foam, a binder is used. The binder to be used is not particularly limited, but it is preferable to use a urethane-based solvent-free binder (soft type, hard type). By using a binder, a soft urethane foam with a density of 50 kg/ ^m3 or more can be obtained. In addition, by using a binder at the lamination interface between the soft urethane foam and the phenol foam, the adhesive strength between the phenol foam and the soft urethane foam can be improved.

A typical manufacturing method for rebonded foam as a soft urethane foam is as follows. First, a soft urethane foam (at least one of ether-based or ester-based) is crushed into flakes using a crusher. Next, while stirring the urethane foam (soft urethane flake material) crushed into flakes using a stirrer, a binder is sprayed onto it, and after further stirring for a certain period of time, a binder-coated flake material is manufactured. Next, a predetermined amount of the binder-coated flake material is placed in a mold, and after the upper mold is placed over it and compressed, steam is injected to solidify it into a predetermined shape. Since the solidified binder-coated flake material is at a high temperature due to the injection of steam, it can then be naturally dried to obtain a rebonded foam. In addition, the used rebonded foam collected in the above manufacturing method may be used as the raw urethane foam to obtain a new recycled rebonded foam.

The density of the soft urethane foam is 35 kg/m ³ or more and 420 kg/m ³ or less, preferably 45 kg/m ³ or more and 420 kg/m ³ or less, more preferably 50 kg/m ³ or more and 400 kg/m ³ or less, even more preferably 100 kg/m ³ or more and 400 kg/m ³ or less, particularly preferably 150 kg/m ³ or more and 350 kg/m ³ or less, and most preferably 200 kg/m ³ or more and 350 kg/m ³ or less. When the density is 35 kg/m ³ or more, it has excellent characteristics in impact resistance, sound absorption, and compression characteristics (particularly repeated compression characteristics (residual compression after repeated compression; reduced settling)) as a foamed laminate, and when it is 420 kg/m ³ or less, it has cushioning properties as a foamed laminate while reducing residual compression after repeated compression; and furthermore, it can maintain light weight, so it is easy to handle as a foamed laminate with phenol foam, which is a rigid foam.

Commercially available soft urethane foams may be used, such as ribbon dead foam manufactured by Maioka Foam Co., Ltd.

The thermal conductivity at 23°C in the thickness direction of the portion of the foamed laminate containing the phenolic foam in this embodiment is preferably 0.026 W/(m·K) or less, more preferably 0.015 W/(m·K) or more and 0.025 W/(m·K) or less, even more preferably 0.015 W/(m·K) or more and 0.024 W/(m·K) or less, and particularly preferably 0.015 W/(m·K) or more and 0.023 W/(m·K). The thermal conductivity mainly depends on the performance of the phenolic foam, and can be adjusted, for example, by the composition and viscosity of the phenolic resin when the phenolic foam is produced, the type and ratio of the foaming agent, the ratio of the bubble nucleating agent, the curing conditions, the foaming conditions, etc.

The foam laminate of this embodiment is characterized by its sound-absorbing properties. When sound waves enter a porous material such as soft polyurethane foam, the air vibrations are transmitted directly to the gaps and air in the bubbles inside the material. When the sound waves strike the thin film bubble walls, the membrane surface vibrates, and part of the sound energy is converted into thermal energy, resulting in sound absorption. The foam laminate of this embodiment exhibits excellent sound-absorbing properties due to the high density of the soft polyurethane.

The foam laminate of this embodiment also has excellent compression properties (particularly repeated compression properties (residual compression after repeated compression; reduced settling)). Excellent compression properties are highly dependent on the density of the foam laminate, particularly the soft polyurethane, so the foam laminate of this embodiment has excellent compression properties.

Next, we will explain the details of the manufacturing method for phenol foam.

As a method for producing phenolic foam, a continuous production method can be adopted that includes the steps of mixing a foamable phenolic resin composition containing a phenolic resin, a surfactant, a foaming agent, and an acidic curing agent containing an organic acid using a mixer, discharging the mixed foamable phenolic resin composition onto a facing material, covering the foamable phenolic resin composition discharged onto the facing material from above with a facing material to foam and harden it while performing pre-molding, performing main molding, which is the main step in which the foaming and hardening reaction occurs, and then performing post-curing to dissipate the moisture in the phenolic resin composition.

The phenolic resin used is a resol-type phenolic resin obtained by heating and synthesizing phenols and aldehydes in the presence of an alkali metal hydroxide or an alkaline earth metal hydroxide at a temperature range of 40 to 100°C. The molar ratio of phenols to aldehydes used is preferably in the range of 1:1 to 1:4.5, and more preferably in the range of 1:1.5 to 1:2.5.

Phenols that are preferably used in the synthesis of phenolic resins include phenol, as well as resorcinol, catechol, o-, m- and p-cresol, xylenols, ethylphenols, p-tert-butylphenol, etc. Dinuclear phenols can also be used.

Aldehydes that are preferably used in the synthesis of phenolic resins include formaldehyde itself, paraformaldehyde which can be depolymerized and used, glyoxal, acetaldehyde, chloral, furfural, benzaldehyde, etc., and derivatives of these can also be used.

When synthesizing the resol-type phenolic resin or after synthesis, additives such as urea, dicyandiamide, and melamine may be added as necessary. When adding urea, it is preferable to mix urea that has been methylolated with an alkaline catalyst in advance with the resol-type phenolic resin.

After synthesis, resol-type phenolic resin usually contains excess water, so it is preferable to dehydrate it to achieve a viscosity suitable for foaming.

Various additives such as aliphatic hydrocarbons or high-boiling alicyclic hydrocarbons, or mixtures thereof, viscosity adjusting diluents such as ethylene glycol and diethylene glycol, and other phthalic acid compounds as necessary can also be added to the phenolic resin. The viscosity of the phenolic resin and the phenolic resin composition at 40°C is preferably 5,000 mPa·s or more and 25,000 mPa·s or less.

The moisture content of the phenolic resin used in the mixing process using a mixer is 2.0% by mass or more and 8.0% by mass or less, preferably 2.5% by mass or more and 6.5% by mass or less, and more preferably 3.0% by mass or more and 5.0% by mass or less. If the moisture content in the phenolic resin is high, the bubble film is more likely to break, causing a decrease in the closed cell ratio, i.e., a decrease in the insulating performance. In contrast, if the moisture content of the phenolic resin is 8.0% by mass or less, the bubble film can be prevented from breaking and the insulating performance can be maintained regardless of the amount of acid catalyst. In addition, if the moisture content is 2.0% by mass or more, the viscosity increase can be suppressed and the liquid can be easily transferred within the equipment.

As a surfactant to be added to the phenolic resin, a nonionic surfactant is effective. For example, alkylene oxide, which is a copolymer of ethylene oxide and propylene oxide, a condensation product of alkylene oxide and castor oil, a condensation product of alkylene oxide and an alkylphenol such as nonylphenol or dodecylphenol, polyoxyethylene alkyl ether having 14 to 22 carbon atoms in the alkyl ether portion, fatty acid esters such as polyoxyethylene fatty acid esters, silicone compounds such as polydimethylsiloxane, polyalcohols, etc. are preferable. These surfactants may be used alone or in combination of two or more kinds.

The amount of surfactant used is preferably in the range of 0.3 parts by mass to 10 parts by mass per 100 parts by mass of phenolic resin.

The foaming agent added to the phenolic resin is preferably a hydrocarbon, a hydrofluorocarbon, a chlorinated hydrofluoroolefin, a non-chlorinated hydrofluoroolefin, or a chlorinated hydrocarbon.

Preferred hydrocarbons are cyclic or chain alkanes, alkenes, and alkynes having 3 to 7 carbon atoms, and specific examples include normal butane, isobutane, cyclobutane, normal pentane, isopentane, cyclopentane, neopentane, normal hexane, isohexane, 2,2-dimethylbutane, 2,3-dimethylbutane, cyclohexane, etc. Among these, pentanes such as normal pentane, isopentane, cyclopentane, and neopentane, and butanes such as normal butane, isobutane, and cyclobutane are preferably used.

Examples of hydrofluorocarbons include hydrofluoropropene, hydrochlorofluoropropene, hydrobromofluoropropene, hydrofluorobutene, hydrochlorofluorobutene, hydrobromofluorobutene, hydrofluoroethane, hydrochlorofluoroethane, and hydrobromofluoroethane.

Chlorinated hydrofluoroolefins that have particularly low thermal conductivity as foaming agents include HCFO-1224yd(Z) (chemical name: (Z)-1-Chloro-2,3,3,3-Tetrafluoropropene), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd, for example, E-form (HCFO-1233zd(E)), manufactured by Honeywell Japan, Ltd., product name: Solstice(TM) LBA), and 1,1,2-trichloropropene. 1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xa), 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 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 1-chloro-1,2,3-trifluoropropene (HCFO-1233yd), 3-chloro-2,3,3-trifluoropropene (HCFO-1233ye), 3-chloro-2,3,3-trifluoropropene (HCFO-1233yf), 1-chloro-1,3,3-trifluoropropene (HCFO-1233zb), and 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd). These configurational isomers, i.e., E or Z configurations, are used either singly or in mixture. Another example is (E)-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd(E)).

Non-chlorinated hydrofluoroolefins include 1,3,3,3-tetrafluoroprop-1-ene (HFO-1234ze, for example, E-form (HFO-1234ze(E)), manufactured by Honeywell Japan, Inc., product name: Solstice(trademark) ze), 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz, for example, Z-form (HFO-1336mzz(Z)), manufactured by Chemours Inc., Opteon(trademark) 1100), 2,3,3,3-tetrafluoroprop-1-ene (HFO-1234ze, for example, E-form (HFO-1234ze(E)), manufactured by Honeywell Japan, Inc., product name: Solstice(trademark) ze), These include 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), and 1,1,1,4,4,5,5,5-octafluoro-2-pentene (HFO-1438mzz), and one or a mixture of these configurational isomers, i.e., E or Z isomers, is used.

When using chlorinated hydrofluoroolefins or non-chlorinated hydrofluoroolefins, the content of these blowing agents in the total blowing agents is preferably 30 mass% or more.

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 include dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride. Of these, propyl chloride and isopropyl chloride, which are chloropropanes, are more preferably used.

The above-mentioned foaming agents may be used alone or in combination of two or more types, and may be selected arbitrarily.

The preferred amount of foaming agent in the foamable phenolic resin composition may vary depending on the type of foaming agent, its compatibility with the phenolic resin, and foaming and curing conditions such as temperature and residence time, but is preferably 10.0 parts by mass or less, more preferably 4.5 parts by mass or more and 10.0 parts by mass or less, and even more preferably 5.0 parts by mass or more and 9.0 parts by mass or less, per 100 parts by mass of the total of the phenolic resin and surfactant.

In this embodiment, a foam nucleating agent may be further used in the production of the phenol foam. As the foam nucleating agent, a gaseous foam 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, argon, or air, may be added. In addition, a solid foam nucleating agent such as inorganic powders such as aluminum hydroxide powder, aluminum oxide powder, calcium carbonate powder, talc, kaolin, silica stone powder, silica sand, mica, calcium silicate powder, wollastonite, glass powder, glass beads, fly ash, silica fume, gypsum powder, borax, slag powder, alumina cement, or Portland cement, or an organic powder such as crushed powder of phenol foam may be added. These may be used alone, or two or more types may be used in combination, regardless of whether they are gaseous or solid. The timing of adding the foam nucleating agent may be determined arbitrarily as long as it is supplied into the mixer that mixes the foamable phenolic resin composition.

The amount of gaseous foam nucleating agent added to the foaming agent is preferably 0.2% by mass to 1.0% by mass, and more preferably 0.3% by mass to 0.5% by mass, based on 100% by mass of the foaming agent. The amount of solid foam nucleating agent added is preferably 3.0 parts by mass to 10.0 parts by mass, and more preferably 4.0 parts by mass to 8.0 parts by mass, based on 100 parts by mass of the total of the phenolic resin and surfactant.

The acidic curing agent to be added to the phenolic resin composition must contain an organic acid as an acid component. The organic acid is preferably arylsulfonic acid or an anhydride thereof. Examples of arylsulfonic acid and anhydrides thereof include toluenesulfonic acid, xylenesulfonic acid, phenolsulfonic acid, substituted phenolsulfonic acid, xylenolsulfonic acid, substituted xylenolsulfonic acid, dodecylbenzenesulfonic acid, benzenesulfonic acid, naphthalenesulfonic acid, and the like, and their anhydrides. 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 a curing aid. These curing agents may also be diluted with a solvent such as ethylene glycol or diethylene glycol.

The amount of acidic hardener used varies depending on the type. When using a mixture of 60% by weight of paratoluenesulfonic acid monohydrate and 40% by weight of diethylene glycol, the amount is preferably 8 parts by weight to 20 parts by weight, more preferably 10 parts by weight to 15 parts by weight, per 100 parts by weight of the total of the phenolic resin and the surfactant.

The surfactant, foaming agent, etc. contained in the foamable phenolic resin composition may be added to the phenolic resin in advance, or may be added to the phenolic resin simultaneously with the acidic curing agent.

In the continuous manufacturing method, the preforming and main forming steps are carried out by various methods according to the purpose of production, such as a method using a slat-type double conveyor, a method using a metal roll or a steel plate, or a method using a combination of these. For example, when molding is carried out using a slat-type double conveyor, the foamable phenolic resin composition covered with upper and lower facing materials is continuously guided into the slat-type double conveyor, and then pressure is applied from above and below while heating, so that the composition is foamed and cured while being adjusted to a predetermined thickness, and formed into a plate shape.

A flexible surface material (flexible surface material) is used as the surface material placed on at least the top and bottom surfaces of the phenol foam. Preferred flexible surface materials include nonwoven and woven fabrics whose main components are polyester, polypropylene, nylon, etc., papers such as craft paper, glass fiber mixed paper, calcium hydroxide paper, aluminum hydroxide paper, magnesium silicate paper, and inorganic fiber nonwoven fabrics such as glass fiber nonwoven fabrics, and these may be mixed or laminated for use. These surface materials are usually provided in roll form.

In the premolding process, the space temperature of the foamable phenolic resin composition when it is first premolded is preferably 35°C or higher and 70°C or lower.

The space temperature in the main forming process following the preforming process is preferably 65°C or higher and 100°C or lower. In this section, the main forming can be carried out using an endless steel belt type double conveyor or a slat type double conveyor, or rolls, etc.

The post-curing process is carried out after the pre-molding process and the main molding process. The space temperature in the post-curing process is preferably 90°C or higher and 120°C or lower.

The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these.

<Synthesis of phenolic resin>
3500 kg of 52% by mass formaldehyde and 2510 kg of 99% by mass phenol were charged into the reactor, and the mixture was stirred with a propeller-rotating agitator, and the temperature of the liquid inside the reactor was adjusted to 40° C. with a temperature controller. The temperature was then raised while adding a 50% by mass aqueous sodium hydroxide solution, and the reaction was carried out. When the Ostwald viscosity reached 60 centistokes (=60×10 ⁻⁶ m ² /s, measured value at 25° C.), the reaction liquid was cooled, and 570 kg of urea (corresponding to 15 mol% of the amount of formaldehyde charged) was added. Thereafter, the reaction liquid was cooled to 30° C., and the pH was neutralized to 6.3 with a 50% by weight aqueous solution of paratoluenesulfonic acid monohydrate.

This reaction liquid was dehydrated at 60°C and the viscosity and water content were measured. The viscosity at 40°C was 6,100 mPa·s and the water content was 5.1% by mass.

<Measurement of moisture content of phenolic resin>
The phenolic resin was dissolved in dehydrated methanol (manufactured by Kanto Chemical Co., Ltd.) in a range of 3% by mass to 7% by mass, and the moisture content of the phenolic resin was calculated by subtracting the moisture content of the dehydrated methanol from the moisture content of the solution, and the difference in the moisture content from the phenolic resin was taken as the resin amount of the phenolic resin. A Karl Fischer moisture meter (manufactured by Kyoto Electronics Manufacturing Co., Ltd., (M.K) C-510) was used for the measurement.

<Viscosity of phenolic resin>
The viscosity of the phenolic resin was measured using a rotational viscometer (manufactured by Toki Sangyo Co., Ltd., R-100 model, rotor part 3°×R-14) after stabilizing at 40° C. for 3 minutes.

Example 1
<Production of phenol foam>
A composition containing 50% by mass of ethylene oxide-propylene oxide block copolymer and 50% by mass of polyoxyethylene dodecyl phenyl ether as surfactants was mixed in a ratio of 3.0 parts by mass to 100 parts by mass of the phenolic resin. This was used as a phenolic resin composition. To 100 parts by mass of the phenolic resin composition, 4.0 parts by mass of phenolic resin foam powder as a solid foam nucleating agent, 4.7 parts by mass of a mixture of 87 mol% cyclopentane and 13 mol% isobutane as a foaming agent, and 10.8 parts by mass of a composition consisting of a mixture of 80 mol% xylene sulfonic acid and 20 mol% diethylene glycol as an acidic hardener were added, and the mixture was fed to a variable speed mixing head whose temperature was adjusted to 25°C. The phenolic resin foam powder used here was a phenolic resin foam (Neoma (registered trademark) foam manufactured by Asahi Kasei Construction Materials Co., Ltd.) pulverized powder (average particle size: 29.0 μm, bulk density: 179 kg/m ³ ) pulverized in the same manner as in Example 1 of JP 2008-024868 A, and was kneaded with the phenolic resin composition in a twin-screw extruder before adding the foaming agent and acidic curing agent. The foaming agent and acidic curing agent were then mixed in a mixer head, and the resulting foamable phenolic resin composition was distributed in a multi-port distribution pipe and supplied onto the moving lower surface material. The foamable phenolic resin composition supplied onto the lower surface material was introduced into a pre-molding process in which the space temperature was adjusted to 60° C., and after 30 seconds, pre-molding was performed from above the upper surface material with a free roller. The pre-molding was adjusted by setting the roll at a height that was 2/3 of the froth height at the time of discharge. The sheet was then sandwiched between two surface materials and introduced into a slat-type double conveyor with a space temperature of 80°C (main molding process), cured with a residence time of 15 minutes, and then cured in an oven with a space temperature of 110°C for 2 hours (post-curing process) to obtain a phenolic foam. For the surface materials, polyester nonwoven fabric (Eltas E05030, Asahi Kasei Corporation, basis weight 30 g/ ^m2 ) was used for both the top and bottom surface materials. This slat-type double conveyor is the equipment disclosed in JP 2000-218635 A.

The density and closed cell ratio of the phenol foam were measured by the methods described below, and the density was 29 kg/m ³ and the closed cell ratio was 94%.

Next, a rebonded foam was produced as a soft urethane in the manner described in the representative method for producing the rebonded foam described above, while the foam laminate of this embodiment was produced as follows. That is, a soft urethane foam waste (90% by mass of ether, 10% by mass of ester) was crushed in a roll crusher type crusher and sieved through a 15 mm diameter sieve to obtain a soft urethane flake material of 15 mm or less. The flake material was then placed in a tank and stirred while spraying a binder (a urethane solvent-free binder) for 3 minutes in the forward direction and 3 minutes in the reverse direction to obtain a binder-coated flake material. The obtained binder-coated flake material was put into the lower mold in an amount equivalent to 200 kg/m ³ (thickness 10 mm), the above-mentioned integrally molded phenol foam (thickness 25 mm) was placed on it, and another binder-coated flake material equivalent to 200 kg/m ³ (thickness 10 mm) was put on top of it, and the upper mold was placed on top and compressed, and steam was injected to solidify and dry, thereby obtaining a foamed laminate with a thickness of 45 mm. The structural diagram and exploded perspective view of the foamed laminate when cut into a 300 mm square are shown in Figure 1 (a) and (b), respectively. As shown in Figure 1, this foamed laminate 1 has soft urethane foam 4 only on both surfaces in the thickness direction of the integrally molded plate-like phenol foam 2.

<Phenol foam density>
After removing the soft urethane foam from the foamed laminate, a 200 mm square phenol foam sample was prepared. After removing the surface material from this sample, the mass and apparent volume were measured according to JIS K7222.

<Density of soft urethane foam>
The flexible urethane foam on both sides of the phenolic foam was separated from the phenolic foam to prepare samples, and the mass and apparent volume of each flexible urethane foam were measured in accordance with JIS K7222, and the average values were calculated.

<Closed cell ratio of phenol foam>
The closed cell ratio of the phenolic foam was measured according to ASTM-D-2856 (C method). Specifically, after removing the soft urethane foam from the foamed laminate and removing the surface material from the phenolic foam, a cylindrical sample with a diameter of 35 mm to 36 mm was hollowed out with a cork borer, and the sample volume was measured by the standard method of using an air comparison type specific gravity meter (Tokyo Science Co., Ltd., Model 1,000). The closed cell ratio was determined by subtracting the volume of the wall (part other than bubbles and voids) calculated from the sample mass and the density of the phenolic resin cured body from the sample volume, and dividing the result by the apparent volume calculated from the outer dimensions of the sample. Here, the density of the phenolic resin was set to 1.3 kg/L. When multiple pieces of phenolic foam are used as the phenolic foam, the closed cell ratio of all the pieces of phenolic foam is measured and the average value is taken to determine the closed cell ratio of the phenolic foam. When the size of the phenolic foam pieces is not sufficient, the dimensions of the cork borer, etc. are adjusted appropriately.

<Thermal Conductivity of Foam Laminate>
The thermal conductivity of the foam laminate in the thickness direction was measured in an environment of 23° C. by the following method in accordance with JIS A 1412-2:1999. The specific procedure is as follows.
The foam laminate was cut into 300 mm squares, and the specimens were placed in an atmosphere of 23±1°C and 50±2% humidity. Thereafter, the weight change over time was measured every 24 hours, and the condition was confirmed and adjusted until the weight change after 24 hours was 0.2% by mass or less. The foam laminate specimens thus conditioned were introduced into a thermal conductivity device also placed in an atmosphere of 23±1°C and 50±2% humidity. If the thermal conductivity measuring device was not placed in the room controlled at 23±1% and 50±2% humidity where the foam laminate specimens were placed, the specimens whose condition was confirmed and adjusted in the above-mentioned atmosphere were quickly placed in a polyethylene bag, the bag was closed, and the specimens were taken out of the bag within one hour, and the thermal conductivity was quickly measured.
The thermal conductivity measurements were performed using a measuring device (Eiko Seiki Co., Ltd., product name "HC-074/FOX304") with one test piece and a symmetrical configuration, with the thermal conductivity at 23°C being 13°C for the low temperature plate and 33°C for the high temperature plate.

<10% Deformation Compressive Stress of Foam Laminate>
In accordance with JIS K 7220:2006, the 10% deformation compressive stress of the foam laminate was measured in an environment of an environmental temperature of 23±2° C. and an environmental humidity of 50±5% by the following method.
The foamed laminate was cut into a 50 mm square to prepare a test piece. Since the number of samples in the test was n=5, five 50 mm square samples were cut out. The width, length and thickness of each test piece were measured using a caliper as specified in JIS K 7248 or JIS B 7507. The compression tester used was an Autograph AG-20kNXD manufactured by Shimadzu Corporation, and a load cell of 20 kN. The test piece was adjusted for 48 hours or more under an environment of an environmental temperature of 23±2°C and an environmental humidity of 50±5%, and then set in the compression tester. The load was measured from the top surface of the test piece when the deformation amount at the time of compression with an initial load of 20 N was 0, and the deformation amount was 10% of the thickness of the test piece. For each test piece, the measured load value was divided by the area to calculate the 10% deformation compressive stress (kPa), and then the average value of the measurement results for the five samples was calculated. The 10% deformation compressive stress is preferably 3 kPa or more, and more preferably 10 kPa or more.

<Evaluation of repeated compression properties of foam laminate>
The foamed laminate was cut into 50 mm squares to prepare test pieces. The test piece was compressed from the top surface to a load of 270 N using a compression tool with a diameter of 100 mm, and then the load was removed to a load of 10 N, with this process being considered as one cycle, and 500,000 cycles were performed. The test was performed at a repetition rate of 10 Hz, an evaluation environment temperature of 23°C ± 5°C, and n = 1. The test machine used was an Instron fatigue tester E10000 ID-E10KN. The evaluation was performed by subtracting the compression change (mm) at the first cycle from the compression change (mm) at the 500,000th cycle. The measurement results are shown in the compression amount (mm), but the compression amount is displayed as a negative value, and the smaller the absolute value of this compression amount, the less the settling, and the better the repeated compression characteristics. In addition, it is preferable to evaluate the foamed laminate by the ratio "S" (the following formula (1)) of the compression amount (Ac; mm) to the thickness (T; mm) of the foamed laminate, and the preferred S value for evaluating the repeated compression properties of the foamed laminate is 0.55 or less, more preferably 0.30 or less, and more preferably 0.15 or less.
-Ac/T=S (1)

Example 2
As shown in Table 1, a foam laminate having a thickness of 45 mm was produced in the same manner as in Example 1, except that the amount of binder-coated flake material was adjusted and a ribbon dead foam having a density of 50 kg/ ^m3 was used as the soft urethane foam.

Example 3
As shown in Table 1, a foam laminate having a thickness of 45 mm was produced in the same manner as in Example 1, except that the amount of binder-coated flake material was adjusted and a rebonded foam having a density of 400 kg/ ^m3 was used as the soft urethane foam.

Example 4
As shown in Table 1, a phenolic foam, Neoma (registered trademark) foam manufactured by Asahi Kasei Building Materials Corporation, having a thickness of 12 mm, density of 41 kg/ ^m3 and closed cell ratio of 93%, was used, and a foam laminate having a thickness of 45 mm was produced in the same manner as in Example 1, except that the upper and lower surface layers of the binder-coated flake material were adjusted to 200 kg/ ^m3 (thickness of 16.5 mm).

Example 5
A foam laminate was produced in the same manner as in Example 2, except that the phenol foam of Example 4 was used.

Example 6
As shown in Table 1, a foam laminate was produced in the same manner as in Example 1, except that multiple pieces of phenol foam were used as the phenol foam (four pieces of phenol foam measuring 75 mm x 225 mm and two pieces of phenol foam measuring 75 mm x 150 mm were combined as Neoma foam pieces manufactured by ^Asahi Kasei Construction Materials Co., Ltd., having a thickness of 25 mm and a density of 29 kg/m3). The structural diagram and the exploded perspective view of the foam laminate when cut into a 300 mm square are shown in Figure 2 (a) and (b), respectively.

(Comparative Example 1)
As shown in Table 1, a foam laminate was produced in the same manner as in Example 1 except that Achilles Airlon SJO (original thickness 50 mm was sliced and two pieces of 10 mm were obtained, density 30 kg/ ^m3 ) manufactured by Achilles Corporation was used for both the upper and lower layers of soft urethane foam instead of the binder-coated flake material, and a binder (urethane-based solvent-free binder) was applied to the entire surface of each joint surface between the soft urethane foam and the phenolic foam.

The foamed laminates obtained in Examples 1 to 6 and Comparative Example 1 were evaluated and observed for the type of soft urethane foam, density of the soft urethane foam, density of the phenolic foam, closed cell ratio of the phenolic foam, configuration of the foamed laminate, thermal conductivity of the foamed laminate, 10% deformation compression stress of the foamed laminate, and repeated compression properties of the foamed laminate. The results are shown in Table 1.

Compared to the foam laminate obtained in Comparative Example 1, the foam laminates obtained in Examples 1 to 6 are foam laminates that have the high thermal insulation performance of phenol foam, but also have excellent 10% deformation compressive stress and repeated compression properties.

Reference Signs List 1 Foam laminate 2 Phenol foam 3 Phenol foam piece 4 Soft urethane foam

The present invention makes it possible to use a foam laminate that has the high thermal insulation performance of phenolic foam while also having excellent compression properties.

Claims (5)

A foam laminate in which at least a portion of the periphery of a phenol foam is covered with a soft urethane foam,
The density of the phenol foam is 20 kg/m3 ^or more and 80 kg/m3 ^or less,
The phenol foam has a closed cell rate of 85% or more;
The density of the flexible urethane foam is 35 kg/m3 ^or more and 420 kg/m3 ^or less ,
A foamed laminate in which, at an evaluation environment temperature of 23°C±5°C, a 50 mm square specimen is compressed from the top surface thereof with a compression jig having a diameter of 100 mm until a load of 270 N is applied, and then the load is removed until the load is 10 N, with this process being defined as one cycle, and the cycle is repeated for 500,000 cycles at a repetition rate of 10 Hz, and the ratio of the compression amount (Ac; mm) (compression amount is shown as a negative value) obtained by subtracting the compression change amount (mm) at the 1st cycle from the compression change amount (mm) at the 500,000th cycle to the thickness (T; mm) of the foamed laminate is defined as "S" (formula (1) below), and the S value is 0.55 or less .
-Ac/T=S (1) The foam laminate according to claim 1, in which the soft urethane foam is provided only on both surfaces of the phenol foam in the thickness direction. The foam laminate according to claim 1 or 2, wherein the thermal conductivity of the foam laminate at 23°C is 0.026 W/(m·K) or less. The foam laminate according to any one of claims 1 to 3, wherein the flexible urethane foam is a ribbon dead foam. The foam laminate according to any one of claims 1 to 4, wherein the phenolic foam is made of a plurality of phenolic foam pieces.

Images