Phenolic resin foam composite

Abstract

To provide a phenol resin foam article which improves brittleness on a surface of a foam, and is reduced in expansion by a volatile component that is generated over time after production of a phenol resin foam.SOLUTION: A phenol resin foam composite body includes a phenol resin foam, and a film on at least a partial surface of the phenol resin foam, wherein the film is formed of a polymer material, the film has a plurality of holes, a ratio of the total area of the hole in a surface of the film having the hole is 0.1% or more and 12.0% or less, a maximum hole area of the hole is 1.0 mm2 or less, and film thickness of the film is within a range of 5 μm or more and 1,000 μm or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a phenolic resin foam composite.

Background Art

[0002] In recent years, from the viewpoint of suppressing energy consumption as part of measures against global warming, examples of using foamed plastic heat insulators in various applications have been increasing. Among these, high performance is required for heat insulators used under conditions where they must be managed at a constant temperature regularly or constantly, such as in factory manufacturing facilities. For example, pipe covers used for heat preservation of pipelines are required to be stably usable at high temperatures exceeding 150°C. Products that exhibit high heat insulation performance in such high-temperature environments are few, and in response to this, phenolic resin foams having high heat resistance have attracted attention.

[0003] Phenolic resin foams are usually used with a surface material, but when processed into various shapes for use, the surface material can also be removed and used. However, in this case, it was necessary to handle them carefully so that the surface of the foam would not be affected by contact with other hard objects.

[0004] Regarding the improvement of the surface strength of the foam, for example, a technique is disclosed in which a protective material layer formed by impregnating a soft synthetic resin foam board with a curable synthetic resin stock solution and curing it is adhered and integrated onto the foam. (Patent Document 1)

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, when such means are used, in an extreme environment where it is continuously exposed to a high temperature state of 150 °C or higher for a long period of time, most foamed plastic thermal insulation materials become unusable. Among them, even for a phenolic resin foam with high heat resistance, after production, the curing reaction of the phenolic resin proceeds slightly, resulting in the release of volatile components such as moisture. It has been found that volatile components may accumulate at the interface between the protective material layer and the phenolic resin foam, causing swelling in the protective material layer.

[0007] Therefore, an object of the present invention is to provide a phenolic resin foam article in which the brittleness of the surface is improved and no swelling due to volatile components generated over time occurs after the production of the phenolic resin foam even in an extreme environment.

Means for Solving the Problems

[0008] That is, the present invention provides the following [1] to [4]. [1] A phenolic resin foam, A film on at least a part of the surface of the phenolic resin foam, A phenolic resin foam composite comprising: The film is made of a polymer material, The film has a plurality of pores, The ratio of the total area of the pores on the surface of the film having the pores is 0.1% or more and 12.0% or less, The maximum pore area of the pores is 1.0 mm 2 or less, The film thickness of the film is in the range of 5 μm or more and 1000 μm or less, a phenolic resin foam composite. [2] The phenolic resin foam composite according to [1], wherein the film is on all surfaces of the phenolic resin foam. [3] The phenolic resin foam composite according to [1] or [2], wherein the film is a coating film. [4] The density of the phenolic resin foam is 15 kg / m 3 or more and 100 kg / m3 is as follows, the closed cell ratio of the phenolic resin foam is 70% or more and less than 100%, the average cell diameter of the phenolic resin foam is 5 μm or more and 200 μm or less, the phenolic resin foam composite according to any one of [1] to [3].

Advantages of the Invention

[0009] According to the present invention, it is possible to provide a phenolic resin foam composite in which the brittleness of the surface is improved and, even in a harsh environment, swelling due to volatile components generated over time does not occur after the production of the phenolic resin foam.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0011] Modes for carrying out the present invention (hereinafter sometimes referred to as "the present embodiment") will be described in detail.

[0012] The ratio of the total area of the pores on the surface of the membrane having pores of the phenolic resin foam composite of the present embodiment is determined by the method described in the examples.

[0013] The maximum pore area of the pores of the phenolic resin foam composite of the present embodiment is determined by the method described in the examples.

[0014] The film thickness of the membrane of the phenolic resin foam composite of the present embodiment is determined by the method described in the examples.

[0015] The density of the phenolic resin foam of the present embodiment is determined by the method described in the examples.

[0016] The closed cell ratio of the phenolic resin foam of this embodiment is determined by the method described in the examples.

[0017] The average cell diameter of the phenolic resin foam of this embodiment is determined by the method described in the examples.

[0018] The phenolic resin foam composite in this embodiment has a film on at least a part of the surface of the phenolic resin foam. The film in the present invention is a structure containing a polymer and has through-holes connecting the film surface and the foam cell structure, and the holes on the film surface are in a form specified by the following description.

[0019] In one embodiment, the holes on the film surface are irregularly present. In another embodiment, the holes on the film surface are a combination of regularly present holes and irregularly present holes. For example, in a part of the film surface, the holes may be regularly present, and in another part, the holes may be irregularly present.

[0020] The ratio of the total area of the holes on the surface of the film having holes of the phenolic resin foam composite of this embodiment is 0.1% or more and 12.0% or less, preferably 0.3% or more and 10.0% or less, more preferably 0.5% or more and 8.0% or less. When the area ratio of the holes is 0.1% or more, the volatile components generated by the progress of the curing of the phenolic resin foam can be sufficiently dissipated through the holes. Also, when the area ratio is 12.0% or less and the maximum hole area described below is 1.0 mm 2 The following, the abrasion resistance can be improved.

[0021] The maximum hole area of the holes formed in the film of this embodiment is 1.0 mm 2 or less, preferably 0.002 mm 2 or more and 0.8 mm 2 or less, more preferably 0.004 mm 2 or more and 0.6 mm 2 or less. When the maximum hole area is 1.0 mm 2 or less, the abrasion resistance of the phenolic resin foam composite is improved, and when the maximum hole area is 0.002 mm2 In the above case, the volatile components generated due to the progress of the curing of the phenolic resin foam can be sufficiently dissipated.

[0022] The film thickness of the film in this embodiment is in the range of 5 μm or more and 1000 μm or less, preferably in the range of 10 μm or more and 800 μm or less, and more preferably in the range of 15 μm or more and 600 μm or less. If the film thickness is 5 μm or more, the brittleness can be improved, and if the film thickness is 1000 μm or less, there is no risk of impairing the light weight property.

[0023] The preferable density range of the phenolic resin foam used in this embodiment is 15 kg / m 3 or more and 100 kg / m 3 or less, and more preferably 20 kg / m 3 or more and 80 kg / m 3 or less, and even more preferably 25 kg / m 3 or more and 60 kg / m 3 or less. If the density is 15 kg / m 3 or more, it has a strength that is difficult to be damaged during handling, and if it is 100 kg / m 3 or less, it becomes lightweight, so the workability is improved.

[0024] The preferable range of the closed cell ratio of the phenolic resin foam used in this embodiment is 70% or more and less than 100%, more preferably 80% or more and less than 100%, and particularly preferably 85% or more and less than 100%. If the closed cell ratio is 70% or more, the phenolic resin foam exhibits heat insulation performance.

[0025] The preferable range of the average cell diameter of the phenolic resin foam used in this embodiment is 5 μm or more and 200 μm or less, more preferably 10 μm or more and 200 μm or less, and even more preferably 10 μm or more and 180 μm or less. If the average cell diameter is 200 μm or less, the heat conduction due to radiation is suppressed, resulting in high heat insulation performance, and if it is 5 μm or more, the closed cell ratio can be maintained.

[0026] The preferable thickness of the phenolic resin foam composite of this embodiment is 2 mm or more and 500 mm or less, more preferably 5 mm or more and 400 mm or less, still more preferably 10 mm or more and 300 mm or less. When the thickness of the phenolic resin foam composite is 2 mm or more, the heat insulation performance is further enhanced, and when it is 500 mm or less, the workability is enhanced. The thickness of the phenolic resin foam composite can be measured with a straightedge, calipers, etc.

[0027] As materials for forming the film of the phenolic resin foam composite of this embodiment, for example, aqueous paints such as acrylic resin emulsions, urethane resin emulsions, vinyl chloride resin emulsions, saran resin emulsions, etc.; solvent-based paints such as epoxy resin paints, acrylic resin paints, urethane resin paints, silicone resin paints, fluororesin paints, polyester resin paints, etc. in which resins are dissolved in solvents; powder paints that do not contain solvents, etc. Among them, acrylic resin emulsions and urethane resin emulsions have good compatibility with phenolic resin foams and are preferable.

[0028] As methods for applying or adhering paints to phenolic resin foams, for example, spray painting (also called spray coating), roll coating, curtain coating, dip coating (also called dip coating), etc. are available. Among them, spray painting and dip coating are preferable because a coating film can be formed uniformly to a desired thickness on the surface of the uneven phenolic resin foam.

[0029] The phenolic resin foam composite of this embodiment can be suitably applied to, for example, pipes of plants heated by steam sterilization, compost tanks operated at relatively high temperatures, etc.

[0030] The phenolic resin foam composite of this embodiment can be produced, for example, by processing a single plate or a laminate of single plates of phenolic resin foam into an arbitrary shape such as a pipe cover shape, then covering the phenolic resin foam with a net-like screen, applying a paint for the film to the phenolic resin foam covered with the net-like screen, and immediately removing the net-like screen after application.

[0031] Also, as another method for producing the phenolic resin foam composite of this embodiment without using a net-like screen, a liquid insoluble in the paint, for example, a fluorine-based liquid or the like, is mixed and dispersed in a paint for a film to prepare the paint, and the phenolic resin foam composite can be produced by applying the paint to a phenolic resin foam. Examples of the liquid insoluble in the paint include Optione SF10 (manufactured by Mitsui Chemicals Fluoro Products Co., Ltd.) and Fluorinert FC-72 (manufactured by 3M Japan Ltd.).

[0032] The preferable range of the addition amount of the liquid insoluble in the paint is, for example, 10 parts by mass or more and 120 parts by mass or less, more preferably 20 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the non-volatile content of the paint emulsion.

[0033] The phenolic resin foam composite of this embodiment has high surface strength, and the preferable range of the weight loss rate of abrasion resistance measured by the method described later is 0% or more and 10% or less, more preferably 0% or more and 7% or less, and still more preferably 0% or more and 5% or less.

[0034] The preferable range of the weight loss rate of volatile component release property measured by the method described later for the phenolic resin foam composite of this embodiment is 4% or more and 15% or less, more preferably 6% or more and 10% or less. It can be confirmed that the weight loss rate of the phenolic resin foam composite of this embodiment is larger than that of the phenolic resin foam composite having a film without pores.

Examples

[0035] Details of the materials and jigs used in the examples are as follows. Surfactant: Block copolymer of ethylene oxide - propylene oxide (trade name "Pluronic (registered trademark) F-127" manufactured by BASF) Solvent: Normal pentane, manufactured by Kanto Chemical Co., Inc. Fluorine solvent: Trade name "Optione (registered trademark) SF10" manufactured by Mitsui Chemicals Fluoro Products Co., Ltd. Silicone-modified acrylic emulsion: Product name "Polydurex B3220" manufactured by Asahi Kasei Corporation, non-volatile content 50% by mass Acrylic emulsion: Product name "Exeed Coat FS Clear" manufactured by Taiyo Paint Co., Ltd., non-volatile content 50% by mass Mold: Punching metal with non-woven fabric attached inside, inner dimensions 300 mm × 300 mm × 60 mm Lid: Punching metal with non-woven fabric attached to the back side Mesh screen: Siding mesh sheet, manufactured by Soft 99 Corporation, wire diameter 0.7 mm, mesh opening 0.9 mm Attachment for scanning electron microscope sample preparation: Product name "DII-29010SCTR Smart Coater" manufactured by JEOL Ltd. Scanning electron microscope (SEM): Product name "JCM-7000" manufactured by JEOL Ltd. Air comparison type specific gravity meter: Model 1000, manufactured by Tokyo Science Co., Ltd. Rotational viscometer: Product name "R-100 type" manufactured by Toki Sangyo Co., Ltd., rotor part is 3°×R-14

[0036] The characteristics of the phenolic resin foam and the phenolic resin foam composite of this embodiment were determined by the following methods using the test pieces described later.

[0037] <Ratio of pore area and maximum pore area of the membrane> Five test pieces were cut out with a thickness of about 3 mm and a size of about 10 × 10 mm so as to include the membrane surface. After gold deposition on the membrane surface using an attachment for scanning electron microscope sample preparation, two images of each sample at two locations, for a total of 10 images at a magnification of 50 times, were taken with a SEM so that the fields of view did not overlap. The taken SEM images were binarized with ImageJ (version 1.53b), and the area ratio on the lower luminance side than the rising position of the luminance distribution was calculated and taken as the ratio of the total area of the pores on the surface of the membrane having pores. Also, the area of the largest pore in the taken SEM images was measured and taken as the maximum pore area. Figures 1 and 2 show the binarized and schematic diagrams of the surface SEM images of Example 3 and Comparative Example 2, respectively.

[0038] <Density of phenolic resin foam> The density of the phenolic resin foam of this embodiment was determined by cutting out a phenolic resin foam without a film into a cube with a side length of approximately 50 mm, measuring the dimensions up to 0.1 mm, and dividing the mass of a test piece measured up to 0.01 g by the volume calculated from the outer dimensions. In addition, when it is difficult to calculate the volume by the above method, the density may be determined by dividing the mass by the volume obtained by measuring the volume by immersing it in a liquid or the like.

[0039] <Closed cell ratio of phenolic resin foam> The closed cell ratio of the phenolic resin foam of this embodiment was calculated as follows: First, a phenolic resin foam without a film and joints was cut out into a cube with a side length of approximately 25 mm. Next, the volume of the cube was measured by the standard method of using an air comparison pycnometer. The value obtained by dividing the value obtained by subtracting the volume of the cell wall calculated from the weight and the resin density from the volume by the apparent volume calculated from the outer dimensions was defined as the closed cell ratio. However, the density of the phenolic resin was calculated as 1.27 g / cm 3 for the calculation.

[0040] <Average cell diameter of phenolic resin foam> The average cell diameter of the phenolic resin foam of this embodiment was measured as follows. Four straight lines with a length of 2000 μm (actual length of 10 cm on the image) were drawn on a 50-fold magnification SEM image of a test piece including the film cross section so as not to cross the film cross section. At this time, the starting point of the straight line was placed on the cell wall. The value N was obtained by dividing the length on the image from the starting point of the straight line to the cell wall that the straight line finally crossed by the number of cells that the straight line crossed. The values N of the four straight lines were averaged to obtain the average cell diameter.

[0041] <Film thickness of the film> The length of the perpendicular line to the film surface of the film cross section in the SEM image used for measuring the average cell diameter was obtained. Then, the range from the minimum value to the maximum value of the length was defined as the film thickness range.

[0042] <Brittleness of phenolic resin foam composite> Twelve cubes with a side length of 25 ± 1.5 mm were cut out from the phenolic resin foam. The entire surface of the cubes was coated with a film paint using a spray gun and dried at room temperature for 12 hours or more to obtain test pieces having a coating film on the entire surface of the phenolic resin foam. Also, the uncoated product of Comparative Example 1 was used as a test piece without applying the film paint. Twenty-four Japanese cedar cubes with a side length of 19 ± 0.8 mm dried at room temperature and 12 test pieces were placed in a Japanese cedar wooden box with an inner dimension of 191 mm × 197 mm × 197 mm that could be sealed so that the shavings of the test pieces would not go outside the box. The wooden box was rotated 600 ± 3 times at a speed of 60 ± 2 rotations per minute. After the rotation was completed, the contents of the box were transferred to a sieve with a mesh size of 9.5 mm, and sieving was performed to remove small pieces. Next, if the film remained on the remaining test pieces, the film was removed and the weight was measured. Then, the weight loss rate before and after the test was determined from the weight of the phenolic resin foam before forming the coating film and the weight of the phenolic resin foam after removing the coating film. The brittleness of the phenolic resin foam was evaluated from the weight loss rate of the foam. The smaller the weight loss rate of the foam, the smaller the brittleness of the phenolic resin foam, indicating excellent abrasion resistance.

[0043] <Volatile Component Release Property of Phenolic Resin Foam Composite> Two rectangular parallelepipeds with dimensions of 100 ± 2.0 mm × 100 ± 2.0 mm × 50 ± 2.0 mm were cut out from the phenolic resin foam. The entire surface of the rectangular parallelepipeds was coated with a film paint using a spray gun and allowed to stand at room temperature for 12 hours or more to obtain test pieces having a coating film on the entire surface of the phenolic resin foam. Also, the uncoated product of Comparative Example 1 was used as a test piece without applying the coating. The weight of the obtained test pieces was measured.

[0044] Next, the test pieces were placed in an oven at 180°C. After 16 hours, the test pieces were taken out and cooled at room temperature of 23°C for 30 minutes, and the weight of the test pieces was measured. The volatile component release property was evaluated from the weight loss rate of the test pieces before and after heating in an oven at 180°C.

[0045] <Swelling of Phenolic Resin Foam Composite> Also, for the test pieces for which the volatile component release property was evaluated, the presence or absence of swelling of the test pieces during heating was also confirmed.

[0046] Hereinafter, based on examples, the phenolic resin foam composite of this embodiment will be described in more detail.

[0047] <Production of Phenolic Resin Foam> 3500 g of a 52% by mass aqueous formaldehyde solution and 2510 g of 99% by mass phenol were charged into a reactor, stirred with a propeller-type stirrer, and the temperature of the liquid inside the reactor was adjusted to 40 °C with a temperature controller. Next, while adding a 50% by mass aqueous sodium hydroxide solution, the temperature was raised to carry out the synthesis reaction of the phenolic resin. The viscosity of the phenolic resin reaction solution obtained by the synthesis reaction was measured using an Ostwald viscometer in a constant temperature water bath for viscosity measurement at 25 °C. When the viscosity of the reaction solution reached 60 centistokes, the reaction solution was cooled and 500 g of urea was added. Thereafter, the reaction solution was cooled to 30 °C and neutralized to pH 6.4 with a 50% by mass aqueous solution of paratoluenesulfonic acid monohydrate. The neutralized phenolic resin reaction solution was dehydrated at 60 °C. The dehydrated phenolic resin was stabilized at 40 °C for 3 minutes. When the viscosity of the phenolic resin was measured with a rotational viscometer, it was 5000 mPa·s.

[0048] 2.5 parts by mass of a surfactant was mixed with 100 parts by mass of the dehydrated phenolic resin. 6.0 parts by mass of normal pentane was mixed with the mixture. Further, 5 parts by mass of a mixture of xylene sulfonic acid and diethylene glycol with a mass ratio of 1:1 prepared in advance was mixed with this mixture to prepare a foamable composition. Next, 340 g of the foamable composition was put into a mold and covered. The container was placed in an oven at 80 °C and heated for 60 minutes to produce 8 phenolic resin foams having nonwoven fabrics on the upper and lower surfaces. The surface layer portion including the nonwoven fabric was removed from this phenolic resin foam, and a test piece of a predetermined size was cut out.

[0049] <Example 1> 10 parts by mass of a fluorine solvent was added to 100 parts by mass of a silicone-modified acrylic emulsion diluted 1.3 times and thoroughly mixed to prepare a paint for film. The paint for film was applied to the entire surface of the phenolic resin foam cut into a predetermined size with a spray gun to produce a test piece.

[0050] <Example 2> When spray coating, a test piece was prepared in the same manner as in Example 1, except that a net-like screen was placed over the phenolic resin foam and no fluorine solvent was added.

[0051] <Example 3> A test piece was prepared in the same manner as in Example 1, except that an acrylic emulsion diluted 1.5 times was used instead of the silicone-modified acrylic emulsion diluted 1.3 times.

[0052] <Example 4> When spray coating, a test piece was prepared in the same manner as in Example 1, except that a net-like screen was placed over the phenolic resin foam.

[0053] <Comparative Example 1> In Example 1, a test piece was obtained by using a phenolic resin foam cut into a predetermined size without applying a coating material for the film as it was.

[0054] <Comparative Example 2> A test piece was prepared in the same manner as in Example 1, except that no fluorine solvent was added.

[0055] <Comparative Example 3> A test piece was prepared in the same manner as in Example 1, except that the amount of the fluorine solvent was changed to 60 parts by mass.

[0056]

Table 1

[0057] From Table 1, in the examples, it was possible to provide a phenolic resin foam article in which the brittleness of the surface was improved and the swelling due to the volatile components generated over time after production in the phenolic resin foam was reduced.

Industrial Applicability

[0058] According to the present invention, it is possible to provide a phenolic resin foam article in which the brittleness of the surface is improved and the swelling due to volatile components generated over time after production in the phenolic resin foam is reduced.

Claims

1. A phenolic resin foam, and a film on at least a part of the surface of the phenolic resin foam, A phenolic resin foam composite comprising: The film is made of a polymer material, The polymer material consists of the non-volatile components of the emulsion, The film has a plurality of pores, The ratio of the total area of the pores on the surface of the film having the pores is 0.1% or more and 12.0% or less, The maximum hole area of the hole is 1.0 mm ２ or less, The film thickness of the film is in the range of 5 μm or more and 1000 μm or less. A phenolic resin foam composite.

2. The phenolic resin foam composite according to Claim 1, wherein the emulsion is one or more emulsions selected from the group consisting of an acrylic resin emulsion, a urethane emulsion, a vinyl chloride resin emulsion, and a saran resin emulsion.

3. The phenolic resin foam composite according to Claim 1 or 2, wherein the film is on all surfaces of the phenolic resin foam.

4. The phenolic resin foam composite according to any one of Claims 1 to 3, wherein the film is a coating film.

5. The density of the phenolic resin foam is 15 kg / m ３ or more and 100 kg / m ３ or less, and The closed cell ratio of the phenolic resin foam is 70% or more and less than 100%, The phenolic resin foam composite according to any one of Claims 1 to 4, wherein the average cell diameter of the phenolic resin foam is 5 μm or more and 200 μm or less.

Images