JP2018165049A - Phenol resin foam laminated sheet, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phenol resin foam laminated sheet that has less warp, excellent external appearance, and further improved heat-insulating performance.SOLUTION: There is provided a phenol resin foam laminated sheet in which a flexible face material is arranged on each of both surfaces of phenol resin foam in a thickness direction, the phenol resin foam has density of 20 kg/mor more and 50 kg/mor less, the average bubble diameter of 20 μm or more and 180 μm or less, the central layer closed-cell ratio of 85% or more, and the skin layer closed-cell ratio of 80% or more.SELECTED DRAWING: None

Description

  The present invention relates to a phenolic resin foam laminate and a method for producing the same, and more particularly to a phenol resin foam laminate and a method for producing the same that are excellent in closed cell ratio of skin layers on the upper and lower surfaces in the thickness direction of the phenol resin foam.

  Phenol resin foam laminates made from resol-type phenolic resin are less flammable, produce less smoke, and have good heat insulation properties. For example, outer wall materials such as metal siding, inner walls of partition panels, etc. In addition to wood, it is used for building materials such as ceiling materials, fire doors, and shutters. In addition, acid-curing phenolic resin foam laminates are widely used as cold insulation and heat insulation materials for building materials and industrial plants.

  Here, the phenolic resin foam laminated board has been under various efforts to improve heat insulation in recent years, and has been particularly focused on improving the closed cell ratio inside the foam (center part). Moreover, in patent document 1, after manufacturing the thick phenol resin foam and carrying out the slice cutting | disconnection by arbitrary thickness in the thickness direction by aligning the density distribution of the thickness direction, the approach utilized as a plurality of phenol resin foam. Although being made, it is difficult to make various physical properties such as the closed cell ratio constant due to the difference in the position in the thickness direction, and it has been desired that the closed cell ratio be high in the thickness direction.

International Publication No. 2014/133023 International Publication No. 2010/126024 International Publication No. 2012/053493

  The manufacturing method of the phenol resin foam laminate includes a mixing step of mixing the foamable phenol resin composition with a mixer, and a lower surface that travels by distributing and widening the mixed foamable phenol resin composition by a plurality of discharge nozzles. Continuous production comprising a discharge process for discharging onto a material and a foam laminate manufacturing process for manufacturing a phenolic resin foam laminate by inflating the foamable phenolic resin composition discharged onto the lower surface material until it adheres to the upper surface material The method is common. In addition, the widening said here refers to expanding an ejection port with respect to the direction (width direction of a face material) orthogonal to the running direction of a face material.

  In Patent Document 2, efforts have been made to promote the dissipation of moisture generated during curing and to improve production efficiency. Specifically, foaming is performed using a double conveyor type molding device having an opening ratio of a certain level or more. It is intended to improve manufacturing efficiency by curing. However, this technique does not provide a step of pre-molding the foamable phenolic resin composition discharged on the face material into a plate shape while foaming and curing the foamable phenol resin composition. Curing proceeds. Here, if the temperature is high in the main molding step, foaming tends to proceed more easily than curing, and the average cell diameter becomes large, which is not desirable. On the other hand, if the temperature in the main molding step is too low, curing is delayed compared to foaming. For this reason, wrinkles are generated on the face material of the obtained phenolic resin foam laminate, causing a problem in appearance. For this reason, it is important to provide a pre-molding process separately from the main molding process and to proceed with curing without excessive foaming. Although Patent Document 3 is a technique for adjusting a balance between foaming and curing by providing a pre-molding step, it has not been possible to realize an improvement in the closed cell ratio in the skin layer of the phenol resin foam.

When the present inventors conducted earnest research, in order to realize a high closed cell ratio over the thickness direction, the skin layer of the phenolic resin foam in contact with the face material located on the lower side at the time of manufacture is particularly at the time of curing. It has been found that there is a problem that the closed cell ratio is likely to be lowered because the generated water is difficult to dissipate and the reaction heat is easily generated.
As a result of further investigations, while a step of preforming the foamable phenolic resin composition after being discharged onto the flexible face material was provided, the foamable phenol in the thickness direction of the flexible face material was further provided in this step. It has been found that a phenolic resin foam laminate having a high closed cell ratio of the skin layer of the phenolic resin foam can be obtained by providing an air-permeable layer on the surface of the flexible face material that is not in contact with the resin composition. It was. In addition, the phenol resin foam laminate made of a phenol resin foam with a density, average cell diameter, and closed cell ratio of the center layer and skin layer in a specific range has less warpage and good appearance, and its heat insulation is further improved. I found out.

  That is, the present invention provides the following [1] to [6].

[1] A phenol resin foam laminate in which flexible face materials are arranged on both surfaces in the thickness direction of the phenol resin foam, and the phenol resin foam has a density of 20 kg / m ³ or more and 50 kg / m. ^A phenol resin foam laminate having an average cell diameter of ³ or less, an average cell diameter of 20 μm or more and 180 μm or less, a center layer closed cell rate of 85% or more, and a skin layer closed cell rate of 80% or more.
[2]
The phenol resin foam laminate according to [1], wherein the phenol resin foam contains at least one of a hydrocarbon and a chlorinated aliphatic hydrocarbon.
[3]
The phenol resin foam laminate according to [1] or [2], wherein the phenol resin foam contains at least one of a chlorinated hydrofluoroolefin and a non-chlorinated hydrofluoroolefin.
[4] The phenol resin foam laminate according to any one of [1] to [3], wherein the flexible face material is a woven fabric or a nonwoven fabric.
[5] A step of mixing a foamable phenol resin composition containing a phenol resin, a surfactant, a foaming agent, and an acidic curing agent using a mixer, and the mixed foamable phenol resin composition as a flexible face material A step of discharging upward, a step of pre-molding the foamable phenolic resin composition discharged onto the flexible face material while foaming and curing in a space adjusted to a temperature of 70 ° C. or lower, a foamable phenolic resin composition Including the step of foaming and curing in a space temperature-controlled at 70 ° C. or higher using a molding apparatus to perform main molding, and in the pre-molding step, the flexibility on the side where the foamable phenol resin composition does not contact A method for producing a phenolic resin foam laminate, wherein the face material surface is in contact with the air-permeable layer.
[6] The method for producing a phenolic resin foam laminate according to [5], wherein an opening ratio of the ventilation layer in the preforming step is 5% or more and 95% or less.

According to the present invention, a phenolic resin foam laminate in which flexible face materials are arranged on at least upper and lower surfaces in the thickness direction of the phenol resin foam, the density is 20 kg / m ³ or more and 50 kg / m ³ or less, A phenol resin foam laminate having an average cell diameter of 20 μm or more and 180 μm or less, a center layer closed cell rate of 85% or more, and a skin layer closed cell rate of 80% or more and having a high closed cell rate over the thickness direction is obtained. be able to. Moreover, it discovered that the phenol resin foam laminated board of this invention had few curvature, the external appearance was favorable, and the heat insulation is further improved.

  Hereinafter, the present invention will be described in detail according to preferred embodiments thereof. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

The phenolic resin foam laminate in the present embodiment (hereinafter sometimes referred to as “foam laminate”) is present in a state in which a large number of bubbles are dispersed in a phenolic resin cured body formed by a curing reaction. It is a laminated board provided with a phenol resin foam and a flexible face material provided on at least the upper and lower surfaces of the phenol resin foam.
And the phenol resin foam laminated board of this embodiment has a high closed cell rate over the thickness direction, and has the outstanding long-term heat insulation performance. In addition, since the foam laminate of the present embodiment has a feature of less warping, the quality is evenly distributed in the thickness direction by cutting along a plane perpendicular to the thickness direction, particularly if the thickness is more than 50 mm. This makes it possible to take multiple sheets of phenolic resin foams, making it highly useful as a building material with excellent heat insulation. In addition, the thickness direction of a phenol resin foam laminated board means the side with the smallest dimension among three sides. It is preferable that the phenol resin foam has a thickness of 30 mm or more and 200 mm or less because of restrictions on measurement of the center layer closed cell rate and the skin layer closed cell rate.

The density of the phenol resin foam in the phenol resin foam laminate of the present embodiment is 20 kg / m ³ or more and 50 kg / m ³ or less, preferably 20 kg / m ³ or more and 40 kg / m ³ or less. When the density is 20 kg / m ³ or more, mechanical strength such as compressive strength can be ensured, and breakage during handling of the foam can be avoided. On the other hand, if the density is 50 kg / m ³ or less, the heat transfer of the resin portion is difficult to increase, so that the heat insulation performance can be maintained. The density of the phenol resin foam can be adjusted to a desired value mainly by changing the ratio of the foaming agent, the ratio between the addition amount of the foaming agent and the addition amount of the acidic curing agent, the curing conditions, and the like.

  The average cell diameter of the phenol resin foam of the phenol resin foam laminate is 20 μm or more and 180 μm or less, preferably 40 μm or more and 150 μm or less. It can suppress that the density of a foam becomes high as an average bubble diameter is 20 micrometers or more. As a result, since the heat transfer rate of the resin part in the foam can be reduced, the heat insulation performance of the phenol resin foam can be ensured. On the other hand, if the average cell diameter exceeds 180 μm, the thermal conductivity due to radiation increases, and the heat insulating performance of the foam may be reduced. The average cell diameter of the phenol resin foam can be adjusted to a desired value by, for example, changing the ratio between the addition amount of the foaming agent and the addition amount of the organic acid used as the acidic curing agent.

  The center layer closed cell ratio of the phenol resin foam is 85% or more, preferably 90% or more, more preferably 95% or more. When the center layer closed cell ratio is 85% or more, it is possible to suppress a tendency that the foaming agent in the phenol resin foam is replaced with air and the long-term heat insulation performance is lowered. The center layer closed cell ratio of the phenol resin foam is, for example, a desired value by changing the ratio of the addition amount of the foam nucleating agent, the addition amount of the foaming agent, and the addition amount of the organic acid used as the acidic curing agent. Can be adjusted.

  The skin layer closed cell ratio of the phenol resin foam is 80% or more, preferably 85% or more, more preferably 90% or more. When the skin layer closed cell ratio is 80% or more, the heat insulation performance can be increased in the thickness direction, and the quality is equalized in the thickness direction even when the slice is cut horizontally with respect to the upper and lower surfaces of the thickness. Can be made.

As the phenol resin, a resol type phenol resin synthesized with an alkali metal hydroxide or an alkaline earth metal hydroxide can be used. The resol type phenol resin is synthesized by heating phenols and aldehydes as raw materials in the temperature range of 40 to 100 ° C. with an alkali catalyst. Moreover, you may add additives, such as urea, a dicyandiamide, a melamine, at the time of the synthesis | combination of a resol type phenol resin as needed. When adding these additives, it is more preferable to mix urea methylolated with an alkali catalyst in advance into the resol type phenol resin. Since the resol type phenolic resin after synthesis usually contains excessive moisture, the amount of moisture suitable for foaming is adjusted at the time of foaming. In addition, phenol resins include aliphatic hydrocarbons having 8 or more carbon atoms or alicyclic hydrocarbons having a high boiling point, or a mixture thereof, a diluent for adjusting viscosity such as ethylene glycol and diethylene glycol, and the like. Additives such as material recycled powder can also be added. A phenol resin may be used independently and may be used in combination of 2 or more types.
In addition, in this specification, when adding these additives, a "phenol resin" points out the thing after adding an additive. And in this specification, what added surfactant to "phenol resin" is called "phenol resin composition", and a foaming agent and an acidic hardening | curing agent are needed for "phenol resin composition". Accordingly, a foam nucleating agent added to impart foamability and curability is referred to as a “foamable phenolic resin composition”.

  The starting molar ratio of phenols to aldehydes during the phenol resin synthesis 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.

Here, the phenols preferably used in the synthesis of the phenol resin in this embodiment are phenol itself and other phenols. Examples of other phenols include resorcinol, catechol, o-, m- And p-cresol, xylenols, ethylphenols, p-tertbutylphenol and the like. Dinuclear phenols can also be used.
The aldehydes may be any compound that can serve as an aldehyde source, and it is preferable to use formaldehyde itself and other aldehydes or derivatives thereof. Examples of other aldehydes include glyoxal, acetaldehyde, chloral, furfural, benzaldehyde and the like.

The viscosity at 40 ° C. of the phenol resin and the phenol resin composition 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, Preferably, it is 9,000 mPa · s or more and 40,000 mPa · s or less.
The water content of the phenol resin and the phenol resin composition is preferably 1.5% by mass or more and 30% by mass or less.

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

  As the surfactant, those generally used for the production of phenol resin foams can be used. Among them, nonionic surfactants are effective, for example, alkylene which is a copolymer of ethylene oxide and propylene oxide. Oxides, condensation products of alkylene oxide and castor oil, condensation products of alkylene oxide and alkylphenols such as nonylphenol and dodecylphenol, polyoxyethylene alkyl ethers having 14 to 22 carbon atoms in the alkyl ether portion, Preference is given to fatty acid esters such as polyoxyethylene fatty acid esters, silicone compounds such as polydimethylsiloxane, and polyalcohols. These surfactants may be used alone or in combination of two or more. Moreover, there is no restriction | limiting in particular about the usage-amount, It uses preferably in 0.3 to 10 mass parts with respect to 100 mass parts of phenol resins.

Although it does not specifically limit as a foaming agent, It is preferable to use HFCs and HCs (hydrocarbon) which do not destroy an ozone layer. In particular, since the global warming potential is small, it is more preferable to use hydrocarbons.
Moreover, as a foaming agent, it is preferable to use at least one of a hydrocarbon and a chlorinated hydrocarbon from a viewpoint of improving the heat insulation performance of a phenol resin foam laminated board, suppressing manufacturing cost. Moreover, it is preferable to contain at least one of a chlorinated hydrofluoroolefin and a non-chlorinated hydrofluoroolefin from a viewpoint of improving the heat insulation performance of a phenol resin foam laminated board more.

  The hydrocarbon is preferably a cyclic or chain alkane, alkene or alkyne having 3 to 7 carbon atoms, specifically, normal butane, isobutane, cyclobutane, normal pentane, isopentane, cyclopentane, neopentane, normal hexane, Examples include isohexane, 2,2-dimethylbutane, 2,3-dimethylbutane, and cyclohexane. Among them, normal pentane, isopentane, cyclopentane, neopentane pentane and normal butane, isobutane, cyclobutane butane are preferably used. These hydrocarbons may be used alone or in combination of two or more.

The amount of the foaming agent relative to the phenolic resin varies depending on the type of foaming agent, compatibility with the phenolic resin, and loss in the foaming / curing process, but is preferably 3.0 to 11.0 parts by mass. It is more preferably 0 to 9.5 parts by mass. When the amount of the foaming agent relative to the phenol resin is 3.0 parts by mass or more, the density is preferably 50 kg / m ³ or less, which is preferable. Moreover, since the density will be 20 kg / m < ³ > or more, it is preferable that the quantity of the foaming agent with respect to a phenol resin is 11.0 mass parts or less.

  Chlorinated aliphatic hydrocarbons can also be used as blowing agents other than hydrocarbons. As the chlorinated aliphatic hydrocarbon, a linear or branched one having 2 to 5 carbon atoms is used. Although the number of bonded chlorine atoms is not limited, 1 to 4 is preferably used, and examples thereof include dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, isopentyl chloride and the like. It is done. Of these, propyl chloride and isopropyl chloride, which are chloropropanes, are more preferably used. These chlorinated aliphatic hydrocarbons may be used alone or in combination of two or more.

Moreover, a chlorinated hydrofluoroolefin and a non-chlorinated hydrofluoroolefin can also be used as a foaming agent. Specific examples of the chlorinated hydrofluoroolefin include 1-chloro-3,3,3-trifluoropropene.
Further, as the non-chlorinated hydrofluoroolefin, specifically, 1,3,3,3-tetrafluoro-1-propene, 2,3,3,3-tetrafluoro-1-propene, 1,1, 1,4,4,4-hexafluoro-2-butene and the like.

  In addition, these foaming agents may be used independently, may be used in combination of 2 or more types, and can be selected arbitrarily.

  Moreover, a foam nucleating agent can also be added as needed. As the foam nucleating agent, a low boiling point material having a boiling point lower by 50 ° C. or more than the foaming agent, such as nitrogen, helium, argon, or air, can be used. Also, as solid foam nucleating agent, aluminum hydroxide powder, aluminum oxide powder, calcium carbonate powder, talc, sand clay (kaolin), quartzite powder, quartz sand, mica, calcium silicate powder, wollastonite, glass powder, glass Inorganic powders such as beads, fly ash, silica fume, gypsum powder, borax, slag powder, alumina cement, and Portland cement, and organic powders such as phenol resin foam powder can also be added. These may be used alone or in combination of two or more.

The acidic curing agent may be an acidic curing agent that can cure the phenol resin, and preferably contains an organic acid. As the organic acid contained in the acidic curing agent, phosphoric acid, arylsulfonic acid, or anhydrides thereof are preferable. As aryl sulfonic acid and its anhydride, toluene sulfonic acid, xylene sulfonic acid, phenol sulfonic acid, substituted phenol sulfonic acid, xylenol sulfonic acid, substituted xylenol sulfonic acid, dodecylbenzene sulfonic acid, benzene sulfonic acid, naphthalene sulfonic acid, etc. And anhydrides thereof. These may be used alone or in combination of two or more. The acidic curing agent may consist only of the organic acid. In addition, these organic acids may be diluted with a solvent such as ethylene glycol or diethylene glycol.
In this embodiment, resorcinol, cresol, saligenin (o-methylolphenol), p-methylolphenol or the like may be added as a curing aid.
The acidic curing agent and the curing aid may be used alone or in combination of two or more.

  The amount of the acidic curing agent also varies depending on the type, and when anhydrous phosphoric acid is used, it is preferably 5 parts by mass or more and 30 parts by mass or less, more preferably 8 parts by mass or more and 25 parts by mass with respect to 100 parts by mass of the phenol resin. Used in: When a mixture of 80% by mass of xylene sulfonic acid and 20% by mass of diethylene glycol is used, it is preferably 3 parts by mass or more and 30 parts by mass or less, more preferably 5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the phenol resin. used.

  As the flexible face material disposed on at least the upper and lower surfaces of the phenol resin foam, the main components are nonwoven fabrics and woven fabrics made of polyester, polypropylene, nylon, etc., kraft paper, glass fiber mixed paper, calcium hydroxide paper, Paper such as aluminum hydroxide paper and magnesium silicate paper, inorganic fiber nonwoven fabric such as glass fiber nonwoven fabric, and the like are preferable, and these may be mixed or laminated. As said flexible face material, a woven fabric or a nonwoven fabric is preferable. These face materials are usually provided in a roll form. Further, as the flexible face material, a material obtained by kneading an additive such as a flame retardant may be used.

In addition, it is preferable to dissipate reaction heat and moisture from the ventilation layer quickly. When using face materials with good air permeability and small thickness, this technology is effective because they can be quickly dissipated into the atmosphere through the air-permeable layer in contact with the surface of the flexible face material. is there. In particular, it is particularly effective when using nonwoven fabrics and woven fabrics having a relatively small basis weight of 15 g / m ^{2 to} 200 g / m ² .

  Moreover, the phenol resin foam laminate is used for various purposes by using it alone and joining it with an external member. Examples of the external member include a board-like material and a sheet-like / film-like material 1 and combinations thereof. Board-like materials include ordinary plywood, structural plywood, particle board, OSB, and other wood-based boards, and wood wool cement board, wood chip cement board, gypsum board, flexible board, medium density fiber board, calcium silicate board A magnesium silicate plate, a volcanic glassy multilayer plate and the like are preferable. Sheet and 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 moisture-proof film, asphalt waterproof paper, aluminum A foil (with or without holes) is preferable.

  Next, the manufacturing method of a phenol resin foam laminated board is demonstrated.

  A method for producing a phenol resin foam laminate includes a step of mixing a foamable phenol resin composition containing a phenol resin, a surfactant, a foaming agent, and an acidic curing agent using a mixer, and a mixed foamable phenol resin. A step of discharging the composition onto the flexible face material, and pre-molding the foamable phenolic resin composition discharged onto the flexible face material while being foamed and cured in a temperature-controlled space of 70 ° C. or lower. A process (in this specification, sometimes referred to as a “pre-molding process”), a process of foaming and curing the foamable phenolic resin composition in a temperature-controlled space at 70 ° C. or higher by using a molding apparatus to perform main molding. (In the present specification, a continuous production method is generally provided, which may be referred to as a “main molding step”), but batch foam molding using the flexible face material up and down in a mold You can also adopt the method It is a function.

  In the preforming process in the continuous manufacturing method, the foamable phenol resin composition discharged onto the face material while being divided into a plurality of parts is preformed so as to be leveled from the vertical direction while being foamed and cured, and then in the main molding process. It is formed into a plate shape while proceeding with foaming and curing.

  As a method of leveling from the vertical direction in the pre-forming process in the continuous manufacturing method, a method of using a metal roll or a steel plate, a method of using a slat type double conveyor, a method of using a combination of these, and other manufacturing purposes There are various methods depending on the method.

  The temperature of the pre-molding step is 70 ° C. or lower, preferably 10 ° C. or higher and 70 ° C. or lower, and can be adjusted to 10 ° C. or higher and 40 ° C. or lower by adjusting the temperature and residence time in the main molding step. The initial foaming of a foamable phenolic resin composition can be accelerated | stimulated as it is 10 degreeC or more. In addition, when the temperature is 70 ° C. or less, it is possible to suppress the bubble diameter from increasing excessively in the initial stage and increasing the bubble diameter. Further, according to the present invention, the surface of the flexible face material that is not in contact with the foamable phenolic resin composition in the pre-forming step is in contact with the air-permeable layer, and thus the reaction occurs in the pre-forming step. Moisture and heat can be efficiently dissipated, so not only the space temperature but also the lower equipment surface directly in contact with the equipment can be actively heated, so that foaming and curing can be promoted more efficiently. It becomes. The residence time in the preforming step is preferably 0.5 minutes or more and 30 minutes or less, and more preferably 1 minute or more and 20 minutes or less.

  In the continuous method, the temperature of the main forming step is 70 ° C. or higher, preferably 70 ° C. or higher and 100 ° C. or lower, more preferably 75 ° C. or higher and 90 ° C. or lower. As a temperature adjustment method, it is preferable to mainly use hot air in a box-shaped sealed space. Moreover, it is preferable that the residence time of this shaping | molding process shall be 5 minutes or more and less than 2 hours. When the residence time is 5 minutes or longer, foaming and curing can be sufficiently promoted. Moreover, when the foaming and curing of the phenol resin composition are completed to some extent, the characteristics of the obtained phenol resin foam plate hardly change. For this reason, the production efficiency of a phenol resin foam board can be improved as the residence time is less than 2 hours. As a method for the main molding, a method using a slat type double conveyor and a method using a metal roll are common, but not limited thereto. For example, in the case of molding using a slat type double conveyor, the foamable phenol resin composition coated with the upper and lower surface material and pre-molded is continuously guided into the slat type double conveyor and then heated. While applying pressure from above and below to adjust to a predetermined thickness, foaming and curing can be performed to form a plate.

  In order to achieve the present invention, in the pre-molding step, the initial curing is gradually advanced while controlling the foaming state of the foamable phenol resin composition, but the reaction heat and moisture generated at this time are reduced as much as possible. It is important to dissipate through the face material.

  As a result of intensive studies by the inventors, in the step of preforming, by providing a ventilation layer on the surface that does not contact the foamable phenol resin composition in the thickness direction of the flexible face material on the bottom face side, It has been found that a phenol resin foam laminate having a high closed cell ratio in the lower surface side skin layer in the thickness direction and a high closed cell ratio over the entire thickness can be obtained. Here, you may provide a ventilation layer in the surface which does not contact the foamable phenol resin composition in the thickness direction of the flexible face material of an upper and lower surface.

  More specifically, it is common to provide a section not continuously in contact with the equipment on the surface opposite to the surface in contact with the foamable phenolic resin composition in the thickness direction of the upper surface material. On the other hand, the surface opposite to the surface in contact with the foamable phenolic resin composition in the thickness direction of the bottom surface material must support the amount of foamable phenolic resin composition material and the mass of the top and bottom surfaces, In general, it is transported while being placed on a plate or belt. If the difference between the two can be suppressed, that is, by providing a ventilation layer on the surface opposite to the surface in contact with the foamable phenolic resin composition in the thickness direction of the lower surface material, the reaction heat and water generated by the reaction can be removed from the lower surface. It is difficult to accumulate between the material and the phenol resin foam, and the state of reaction heat and moisture can be made uniform with the top material side, and the difference in closed cell ratio distribution in the thickness direction of the obtained phenol resin foam laminate is reduced.

  As an example of the ventilation layer in the pre-molding process, it is important to provide equipment having a certain opening ratio. Heat and water generated by foaming and curing of the foamable phenolic resin composition can be transferred to the outside of the pre-molding machine through the opening. And a method of arranging a layer having a structure that can be released into the metal, for example, punching metal, wire mesh, expanded metal, and free roller. Here, the aperture ratio is defined as the ratio of the total area of the face material not touching the facility to the unit area when the preforming area is temporarily viewed from below. The aperture ratio of the air-permeable layer in this preforming step is preferably 5% or more, more preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more. % Or more is particularly preferable, and 95% or less is preferable. If it is 5% or more, reaction heat and water generated by the reaction can be quickly dissipated. Moreover, if it is 95% or less, it is possible to convey smoothly the upper and lower surface materials and the foamed and hardened foamable phenol resin composition without bending.

As a technique that focuses on the preforming process, Patent Document 3 exists, but in this technique, a preforming process is used to obtain a characteristic phenolic resin foam plate, and the conditions of the preforming process are as follows. Was considered sufficient to manage the space temperature.
The present inventors have examined the conditions of the preforming process in detail, and by controlling the temperature during the preforming more strictly, there is less unevenness across the entire foam and phenol having more uniform physical properties. It has been found that a resin foam can be obtained. Specifically, in addition to the temperature control of the space where preforming is performed, it is effective to provide a member capable of temperature control on the lower surface material side. In addition to performing pre-molding under conditions that allow the temperature of the entire foam laminate to be strictly controlled, and pre-molding by providing a ventilation layer on the temperature-controllable plate, etc., the total thickness It was found that a foam laminate having a more uniform closed cell ratio and less unevenness throughout and having more uniform physical properties can be obtained.

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

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

  When this reaction solution 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. This is designated as phenol resin A-U.

<Moisture content>
The amount of water in the phenolic resin was measured using a Karl Fischer moisture meter MKA-510 (manufactured by Kyoto Electronics Industry Co., Ltd.).

<Viscosity of phenolic resin>
A rotational viscometer (manufactured by Toki Sangyo Co., Ltd., R-100 type, rotor part 3 ° × R-14) was used, and the measured value was obtained after stabilization at 40 ° C. for 3 minutes.

Example 1
Phenol resin AU: 100 parts by mass of ethylene oxide / propylene oxide block copolymer (manufactured by BASF, Pluronic F-127) as a surfactant was mixed at a ratio of 2.0 parts by mass. This is designated as phenol resin composition A-U1.

<The process of mixing using a mixer>
This phenolic resin composition A-U1: 100 parts by mass, 5.6 parts by mass of a mixture of 50% by mass of isopentane and 50% by mass of isobutane as a blowing agent, and nitrogen as a foaming nucleating agent 0.3% with respect to the blowing agent. A foamable phenol resin composition comprising 13% by mass of a mixture of 80% by mass of xylene sulfonic acid and 20% by mass of diethylene glycol was added to the mixing head of the mixer. In addition, the mixer (mixer) used what was disclosed by Unexamined-Japanese-Patent No. 10-225993. That is, there is an inlet for the foaming agent containing the phenol resin composition A-U1 and the foam nucleating agent on the upper side surface of the mixer, and an inlet for the acidic curing agent on the side surface near the center of the agitating unit where the rotor agitates. A mixer equipped with was used. The part after the stirring part is connected to a nozzle for discharging the foamable phenol resin composition. That is, the mixer is composed of the mixing part (front stage) up to the acidic curing agent introduction port, the mixing part (rear stage) from the acidic curing agent introduction port to the stirring end part, and the dispensing end as the stirring end part to the nozzle. Yes. The distribution unit has a plurality of nozzles at the tip, and is designed so that the mixed foamable phenolic resin composition is uniformly distributed.

<Process to discharge onto face material>
Next, the foamable phenol resin composition was supplied onto the moving lower surface material through the multiport distribution pipe. A polyester non-woven fabric (weight per unit area: 30 g / m ² ) was used for the bottom material.

<Pre-molding process>
Furthermore, the foamable phenolic resin composition supplied onto the lower surface material is covered with the upper surface material, and at the same time, sandwiched between the upper and lower surface materials and led to an oven at 40 ° C. (residence time 4 minutes). It was pre-molded using leveling. A punching metal having an opening ratio of 40.2% was placed on the side opposite to the surface in contact with the foamable phenol resin composition in the thickness direction of the bottom material. On the other hand, the surface opposite to the surface in contact with the foamable phenol resin composition in the thickness direction of the upper surface material was an open space whose temperature was adjusted to 40 ° C. A polyester nonwoven fabric having the same specifications as the lower surface material was used for the upper surface material.

<Main molding process>
Then, it was hardened by sending it to an oven having a slat type double conveyor at 83 ° C. and retaining it for 15 minutes. The slat type double conveyor with an aperture ratio of 65% was formed into a plate shape by applying moderate pressure from above and below through the face material.

  Thereafter, it was cured in an oven at 110 ° C. for 2 hours to obtain a phenolic resin foam laminate.

  The characteristics of the phenolic resin foam laminate obtained by Examples and Comparative Examples are obtained by the following method.

<Phenolic resin foam density>
Using a 20 cm square phenolic resin foam plate cut out from the obtained phenolic resin foam laminate, remove the surface material, siding material, etc., from this sample, and measure the mass and apparent volume. The obtained value was measured according to JIS K7222.

<Average cell diameter of phenol resin foam>
Number of bubbles crossed by four straight lines with a length of 90mm on a 50x magnified photograph of the cross section of a test piece cut substantially parallel to the front and back surfaces in the thickness direction of the phenolic resin laminate. Is obtained according to JIS K6402 and is a value obtained by dividing 1800 μm by the average value thereof.

<Center layer closed cell ratio of phenol resin foam>
Measured according to ASTM-D-2856. Specifically, after removing the face material from the phenolic resin foam laminate, a columnar sample having a diameter of 30 mm to 32 mm is pierced with a cork borer, and the height of the phenolic resin foam is centered in the thickness direction. After trimming to 9 mm to 13 mm, the sample volume was measured by a standard usage method of an air-comparing hydrometer (manufactured by Tokyo Science Co., Ltd., type 1,000). The value obtained by subtracting the volume of the wall (parts other than air bubbles) calculated from the sample mass and the density of the phenol resin from the sample volume is divided by the apparent volume calculated from the external dimensions of the sample, and the value multiplied by 100 is independent. It calculated | required as a bubble rate. The same operation was performed at 10 points for a part separated by 50 mm or more from each measurement part, and the lowest measured value was defined as the center layer closed cell ratio. The density of the phenol resin was 1.3 kg / L. In addition, when the thickness of the phenol resin foam is 30 mm or less, a cylindrical sample having a diameter of 30 mm to 32 mm is punched with a cork borer, and the height is 4 mm to 6 mm so that the center in the thickness direction of the phenol resin foam is the center. The same evaluation is performed after cutting the lines.

<Skin layer closed cell ratio of phenol resin foam>
After removing the face material from the phenolic resin foam laminate, a cylindrical sample having a diameter of 30 mm to 32 mm is pierced with a cork borer, and the height of 9 mm to 13 mm so that one side surface in the thickness direction of the phenolic resin foam is one side. Then, the sample volume was measured by a standard usage method of an air comparison type hydrometer (manufactured by Tokyo Science Co., Ltd., type 1,000). The value obtained by subtracting the volume of the wall (portion other than air bubbles) calculated from the sample mass and the density of the phenol resin from the sample volume is divided by the apparent volume calculated from the outer dimension of the sample, and a value obtained by multiplying by 100 is obtained. It was. The same operation was performed at 10 points for a part separated by 50 mm or more from each measurement part, and the lowest measurement value was defined as (a). The density of the phenol resin was 1.3 kg / L. In addition, for the same sample that was punched with a cork borer, after the other surface in the thickness direction of the foam was aligned to a height of 9 mm to 13 mm, all 10 points were measured in the same manner, and the lowest The measured value was (b). Thereafter, the lower measured value of the measured values of (a) and (b) was defined as the skin layer closed cell ratio. In addition, when the thickness of the phenol resin foam is 30 mm or less, a cylindrical sample having a diameter of 30 mm to 32 mm is pierced with a cork borer, and the height of 4 mm to 6 mm so that one surface of the phenol resin foam becomes one side. The same evaluation is performed after cutting the lines.

<Appearance (皺) evaluation>
The phenol resin foam laminate was cut into a size of 1000 mm × 1000 mm, the top and bottom surfaces of the phenol resin foam laminate were visually observed, and the presence or absence of wrinkles was evaluated in two stages, A and B. A total of less than 10 wrinkles having a length of 10 mm or more on both surface layers was A, and B was one having 10 or more wrinkles.

<Appearance (warp) evaluation>
After carefully peeling the upper and lower surface materials of the phenolic resin foam laminate cut out to a size of 1000 mm × 1000 mm to form a phenolic resin foam, a yarn is stretched between the diagonal vertices on the surface not including the thickness direction, Read and record the maximum distance when a perpendicular is drawn from the thread to the surface of the phenolic foam. Further, a yarn is stretched between the other diagonal vertices and measured and recorded in the same manner. The same measurement is performed by turning upside down, and the largest value among these four measurement values is defined as a warp value. In addition, when the yarn does not become a straight line when the yarn is stretched between the diagonal vertices, the warp value is not calculated (if the phenolic resin foam is measured in a convex state, the distance between the diagonals is not calculated. The thread is not straight). The warp value was less than 3 mm, A was 3 mm or more and less than 6 mm, and B was 6 mm or more.

(Example 2)
Instead of installing a punching metal with an opening ratio of 40.2% in the pre-molding step, the opening ratio of the surface on the side opposite to the surface in contact with the foamable phenol resin composition in the thickness direction of the lower surface material is 5.0%. A phenolic resin foam laminate was obtained in the same manner as in Example 1 except that a punching metal was installed.

(Example 3)
Instead of installing a punching metal with an aperture ratio of 40.2% in the pre-molding step, the aperture ratio of the surface opposite to the surface in contact with the foamable phenol resin composition in the thickness direction of the bottom surface material is 95.0%. Thus, the phenol resin foam laminated board was obtained like Example 1 except having arrange | positioned the stainless steel free roller.

Example 4
A phenol resin foam laminate was obtained in the same manner as in Example 1 except that both the upper and lower surface materials were changed to glass fiber mixed paper (weight per unit area 140 g / m ² ).

(Example 5)
A phenolic resin foam laminate was obtained in the same manner as in Example 1 except that both the upper and lower surface materials were changed to glass fiber nonwoven fabric (weight per unit area 140 g / m ² ).

(Example 6)
In the pre-molding step, the space temperature of the first molding step after discharge is 60 ° C., and in this step, the opening ratio of the surface opposite to the surface in contact with the foamable phenolic resin composition in the thickness direction of the face material in both the upper and lower sides A phenol resin foam laminate was obtained in the same manner as in Example 1 except that a slat type double belt conveyor having a ratio of 65% was used.

(Example 7)
A phenol resin foam laminate was obtained in the same manner as in Example 1 except that the preforming step was set to 70 ° C.

(Example 8)
Phenol resin composition A-U1: In the same manner as in Example 1, except that 5.4 parts by mass of a mixture of 70% by mass of cyclopentane and 30% by mass of isobutane was added as a blowing agent to 100 parts by mass. A resin foam laminate was obtained.

Example 9
Phenol resin composition A-U1: To 100 parts by mass, 6.6 parts by mass of a mixture of 25% by mass of cyclopentane and 75% by mass of 1-chloro-3,3,3-trifluoropropene was added as a blowing agent. A phenolic resin foam laminate was obtained in the same manner as in Example 1 except that the oven temperature in the main forming step having a slat type double conveyor was set to 87 ° C.

(Example 10)
6.8 parts by mass of a mixture of 40% by mass of isopropyl chloride and 60% by mass of 1-chloro-3,3,3-trifluoropropene as a blowing agent is added to 100 parts by mass of the phenol resin composition A-U1: A phenol resin foam laminate was obtained in the same manner as in Example 1 except that the oven temperature in the main forming step having a slat type double conveyor was 88 ° C.

(Comparative Example 1)
In the preforming step, the same procedure as in Example 1 was conducted except that the stainless steel plate was arranged so that the opening ratio of the surface opposite to the surface in contact with the foamable phenolic resin composition in the thickness direction of the lower surface material was 0%. Thus, a phenol resin foam laminate was obtained.

(Comparative Example 2)
In the pre-molding step, a stainless steel plate having a slit square hole processed in the width direction so that the opening ratio of the surface opposite to the surface in contact with the foamable phenolic resin composition in the thickness direction of the bottom surface material is 4.6%. Except having used, it carried out similarly to Example 1, and obtained the phenol resin foam laminated board.

(Comparative Example 3)
A phenol resin foam laminate was obtained in the same manner as in Example 1 except that the pre-molding step was eliminated and the space temperature in the main molding step was 80 ° C.

(Comparative Example 4)
A phenol resin foam laminate was obtained in the same manner as in Example 1 except that the pre-molding step was eliminated and the space temperature in the main molding step was 50 ° C.

  The evaluation results of the phenol resin foam laminates obtained in Examples 1 to 10 and Comparative Examples 1 to 4 are summarized in Table 1.

From Table 1, the phenol resin foam of the phenol resin foam laminate obtained in Examples 1 to 10 has a smaller cell diameter than the phenol resin foam laminate obtained in Comparative Examples 1 to 4, It can be seen that the closed cell ratio is high in the thickness direction and has a good appearance.
In addition, compared with the phenol resin foam laminated board obtained by Comparative Examples 1-4, the phenol resin foam laminated board obtained in Examples 1-10 had few curvature, and was excellent also in heat insulation. .

Claims (6)

A phenolic resin foam laminate in which flexible face materials are arranged on both surfaces in the thickness direction of the phenolic resin foam, wherein the phenolic resin foam has a density of 20 kg / m ³ or more and 50 kg / m ³ or less, A phenol resin foam laminate having an average cell diameter of 20 μm or more and 180 μm or less, a center layer closed cell rate of 85% or more, and a skin layer closed cell rate of 80% or more.   The phenol resin foam laminate according to claim 1, wherein the phenol resin foam contains at least one of a hydrocarbon and a chlorinated aliphatic hydrocarbon.   The phenol resin foam laminate according to claim 1 or 2, wherein the phenol resin foam contains at least one of a chlorinated hydrofluoroolefin and a non-chlorinated hydrofluoroolefin.   The phenol resin foam laminated board as described in any one of Claims 1-3 whose said flexible face material is a woven fabric or a nonwoven fabric.   A step of mixing a foamable phenolic resin composition containing a phenolic resin, a surfactant, a foaming agent, and an acidic curing agent using a mixer, and discharging the mixed foamable phenolic resin composition onto a flexible face material A step of pre-molding the foamable phenolic resin composition discharged on the flexible face material while foaming and curing in a space adjusted to a temperature of 70 ° C. or lower, a molding apparatus for the foamable phenolic resin composition The surface of the flexible face material on the side where the foamable phenolic resin composition is not in contact with the foamed phenolic resin composition in the preforming step, including the step of foaming and curing in a space temperature-controlled to 70 ° C. or more using The method for producing a phenolic resin foam laminate, characterized in that is in contact with the ventilation layer.   6. The method for producing a phenolic resin foam laminate according to claim 5, wherein an opening ratio of the air-permeable layer in the preforming step is 5% or more and 95% or less.