WO1998036021A1

WO1998036021A1 - Phenolic resin foam

Info

Publication number: WO1998036021A1
Application number: PCT/JP1998/000622
Authority: WO
Inventors: Yuuichi Arito; Kenzi Takasa
Original assignee: Asahi Kasei Kogyo Kabushiki Kaisha
Priority date: 1997-02-17
Filing date: 1998-02-16
Publication date: 1998-08-20
Also published as: KR100311437B1; AU5880998A; KR20000070241A

Abstract

A phenolic resin foam characterized by having a proportion of closed cells of 70 % or above, a mean cell diameter of 10 to 400 νm and a density of 10 to 70 kg/m3, containing a hydrofluorocarbon in the closed cells, and being made of a phenolic resin having a urea-cross-linked structure. By virtue of the specific cross-linking density and the urea-cross-linked structure, this foam exhibits excellent heat insulating performance and is improved in mechanical strengths and surface brittleness, though HFC is used as the blowing agent.

Description

Specification

Phenol resin foam Technical field

TECHNICAL FIELD The present invention relates to a phenolic resin foam for thermal insulation having excellent heat insulating performance, excellent mechanical strength such as compressive strength, and improved surface brittleness. Background art

Funinol resin foam is very useful as a building material because of its excellent flame retardancy, heat resistance, low smoke emission, dimensional stability, solvent resistance, and workability among organic resin foams. It is something.

In general, conventional phenolic resin foams have a major disadvantage that the foam is brittle, which causes the foam to have poor surface brittleness, cracks, and has a problem in the cell wall. There were problems such as the occurrence of pinholes, the replacement of the blowing agent with air, and a decrease in heat insulation performance.

In order to improve this disadvantage, Japanese Patent Application Laid-Open No. 53-13669 discloses a method in which the amount of water in the resin is extremely limited, and the method disclosed in Japanese Patent Publication No. Sho 63-3-24060. Has proposed a technique to obtain a closed-cell foam by using a high-molecular-weight resole resin to increase the viscosity of the foamable mixture, improve the cell wall strength, and obtain a closed-cell foam. Difficulty, and because of the fragility inherent in phenolic resin, surface brittleness was poor and powdered, and the surface material was easily peeled.

Further, in order to improve the brittleness of the resin, Japanese Unexamined Patent Publication No. Sho 61-238833 discloses a method in which a saccharide is added, and Japanese Patent Publication No. Sho 62-48997 Have tried to use modified phenol or various additives, but none of them was sufficient, and a cell with a high closed cell rate could not be obtained.

Therefore, in these prior arts, the thermal conductivity was at most 0.020 (kca 1 / mhr ° C) or more, and the use as a heat insulating material was limited to those that required fire protection and fire resistance. .

Moreover, in these prior arts, 1, 1, 2-triclo mouth- 1,2,2-Trifluoroethane dichlorofluoromethane and other halogenated hydrocarbons with relatively high boiling points are used, and these chlorine-containing chlorine-containing fluorocarbons (hereinafter referred to as “CFCs”) The use of hydrogenated fluorocarbons (hereinafter referred to as “HCFCs”), in which some of the chlorine in CFCs has been replaced with hydrogen, has been restricted due to suspected destruction of the ozone layer.

Therefore, as a low thermal conductivity gas that does not destroy the ozone layer, fluorocarbons that do not contain chlorine atoms (hereinafter referred to as “HFCs”) are attracting attention as blowing agents. For economic reasons, HFCs that can be used industrially include HFC_134a (1,1,1,2-tetrafluoroethane), HFC-152a (1,1-difluoroethane), HFC — 1 25 (1,1,1,2,2-pentafluoroethane), etc., all of which have a low boiling point, which increases the pressure during foaming and breaks the cell walls, With the conventional technology for producing phenolic resin foam, it is even more difficult to produce products with high thermal insulation performance using these HFCs as foaming agents, for example, due to the large cell diameter. Was.

A common method for producing these phenolic resin foams is to uniformly mix a phenolic resin and a formalin-condensed resin with a foaming agent, surfactant, curing catalyst, and other additives. And foam it.

An object of the present invention is to provide a fusol resin foam for heat insulation, which uses HFC as a foaming agent, has excellent heat insulating performance, has excellent mechanical strength such as compressive strength, and has improved surface brittleness. It is. Disclosure of the invention

The present inventors have conducted intensive studies on phenolic resin foams, and as a result, have a specific cross-linking density, and by providing urea-derived cross-linking, have excellent heat insulation performance even when HFC is used as a blowing agent, The present inventors have found that a phenol resin foam having improved mechanical strength and surface brittleness can be obtained, and have completed the present invention.

That is, the present invention

1. closed cell ratio 70% or more, the average cell diameter 1 0 am or 4 0 0 m or less, the density ¹ 0 kg / ^m: 1 or 7 and at 0 kg / m ³ or less, the Furuoro hydrocarbons in closed cells A phenolic resin foam comprising a phenolic resin structure having a urea cross-linking structure,

2. In the thermal decomposition pattern of the pyrolysis gas chromatography of the phenolic resin, the ratio of trimethylphenol in the pyrolysis products A to the ratio of the phenols in the pyrolysis products to the ratio B Is not less than 0.2 and not more than 4.0, and the ratio F = D / E of the component D derived from urea crosslinking of the thermal decomposition product to the phenol derivative component E is 0.03 or more and 0.3 or less. 3. The phenolic resin foam according to the item 1, wherein

3. The phenolic resin foam according to the above 1 or 2, wherein the thermal conductivity is 0.018 kca 1 mhr r ° C or less, and the brittleness is 30% or less.

4. The fluorohydrocarbon is at least one of 1,1,1,2-tetrafluoroethane or 1,1—difluoroethane or 1,1,1,2,2-pentafluoroethane. The phenolic resin foam according to any one of the above 1 to 3, wherein

5. A resol resin composition consisting of a resole resin and methyl urea monofluoride is formed by forming a urea crosslinked structure by foaming and curing a fluorocarbon hydrocarbon as a foaming agent, with a closed cell rate of 80% or more, average Bubble diameter 20 / m or more and 300 / m or less, density 20 kg / m ³ or more and 50 kg / m ³ or less, thermal conductivity 0.018 kca 1 Xmh r ° C or less, brittleness 30% A phenolic resin foam, characterized in that: BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a pyrolysis gas chromatography pyrogram of a phenolic resin foam sample. The vertical axis indicates the relative intensity.

Figure 2 shows the mass spectrum of the phenol component in a pyrogram of pyrolysis gas chromatography of a phenol resin foam sample.

Figure 3 shows the mass spectrum of the trimethylphenol component of the pyrolysis gas chromatography pyrogram of the phenol resin foam sample.

Figure 4 shows the mass spectrum of the 0-methylphenol component of the pyrolysis gas chromatography pyrogram of the phenol resin foam sample. Fig. 5 shows the mass spectrum of the p-methylphenol component in the pyrogram of the pyrolysis gas chromatograph of the phenol resin foam sample.

6, the Fuwenoru resin foam samples, the pyrolysis gas chromatography Bruno, a Masusu Bae-vector of 2, 4-dimethyl phenol component of ³ Iroguramu. Figure 7 shows the mass spectrum of the 2,6-dimethylphenol component of a pyrolysis gas chromatography pyrogram of a phenol resin foam sample. FIG. 8 is a mass spectrum of one-third of a urea-crosslinking-derived structural component of a pyrogram of a phenol resin foam sample by pyrolysis gas chromatography.

FIG. 9 is a mass spectrum of a structural component derived from one-third of urea cross-links in a pyrolysis gas chromatography pyrogram of a phenol resin foam sample.

FIG. 10 is a mass spectrum of a structural component derived from one urea cross-link in a microgram of pyrogel gas chromatography of a phenol resin foam sample.

Fig. 11 shows a mass spectrum of a structural component derived from one urea cross-link in a pyrolysis gas chromatography pyrogram of a phenol resin foam sample.

FIG. 12 is a mass spectrum of a structural component derived from one-third of a urea cross-linking pyrogram of a phenol resin foam sample.

Hereinafter, the present invention will be described in detail.

In general, when the closed cell ratio is low, not only the surface brittleness of the foam increases, but also the foaming gas in the cells is replaced with air, and the heat insulation performance deteriorates with time. In the present invention, it is important to increase the ratio of closed cells that can hold the foaming gas for a long period of time in order to eliminate the decrease in the heat insulation performance. That is, in the present invention, the closed cell rate needs to be 70% or more, more preferably 80% or more, and still more preferably 90% or more.

The closed cell ratio in the present invention is a volume ratio of closed cells contained in voids in the phenolic resin foam, and is measured by a method described later.

Also, if the average cell diameter of the foam is too small, there is a limit to the thickness of the cell wall, so the foam density inevitably increases, and as a result, the heat transfer ratio of the resin portion increases, and the phenol resin The insulation performance of the foam decreases. On the other hand, if the bubble diameter is too large, heat conduction due to radiation increases and the heat insulation performance decreases. In order to eliminate this decrease in heat insulation performance, The average cell diameter in the present invention must be 10 m or more and 400 m or less, and more preferably 20 m / m or more and 300 m or less.

If the density of the phenolic resin foam is too low, the mechanical strength, such as the compressive strength, will be reduced, and the phenolic resin foam will be easily damaged during handling, and the surface brittleness will also increase. Conversely, if the density is too high, the heat transfer of the resin part increases and the heat insulation performance decreases. To eliminate such trouble, the density of Fuwenoru resin foam of the present invention is 1 0 kg Zm ³ or 7 0 kg Z m ³ must be at or less, more preferably 2 0 kg / m ³ or more 5 0 kg / m ³ or less.

The phenolic resin foam according to the present invention has a phenolic resin structure having a urea crosslinked structure. The phenolic resin structure can be specified by displaying the pattern of the pyrolysis products of the pyrolysis gas chromatography of the fininol resin that forms the foam (hereinafter referred to as the “pyrogram”) (see Fig. 1). . In the pyrogram, the ratio of trimethylphenol A to the ratio of phenol to the ratio of B to B, C = AZB, and the ratio of the component D derived from urea crosslinking to the phenol derivative component E to F = D / E, It does not directly show the structure of the resin foam, but indirectly reflects the structure of the original polymer. That is, the ratio C of the pie mouth grams in pyrolysis gas chromatography is an index reflecting the crosslink density of the phenol resin, and the ratio F is an index reflecting the density of the urea crosslinked structure of the phenol resin. The crosslink density and the density of the urea crosslink structure, and thus the ratios C and F, are based on the amount of urea methylol to be mixed, the molar ratio of formaldehyde and phenol used (hereinafter referred to as the “FZP ratio”), the temperature during foaming, the amount of catalyst, etc. The phenolic resin foam of the present invention having the above excellent properties can be obtained by appropriately selecting these factors.

The component D derived from the urea crosslinking in the ratio F is a component released in the pyrogram during a retention time of 8 minutes to 18 minutes, and contains a phenyl group and an isocyanate (—NCO) group in the molecule. Including compounds. These components are identified by a mass spectrum or the like. Specifically, for example, the peak? The mass spectra corresponding to these are shown in Figs.

The phenol derivative component E having the ratio F is defined as phenol, methylphenol, It is the sum of tilphenol and trimethylphenol. These components are identified by a mass spectrum or the like. Specifically, peaks 1 to 6 and the corresponding mass spectra are shown in FIGS. 2 to 7, respectively.

The ratio C according to the present invention is preferably 0.2 or more and 4.0 or less, more preferably 0.2 or more and 2.0 or less, particularly preferably 0.25 or more and 1.5 or less, and The ratio F is preferably not less than 0.03 and not more than 0.3, more preferably not less than 0.035 and not more than 0.2, and particularly preferably not less than 0.04 and not more than 0.15. In such a phenol resin, the strength of the phenol resin itself is improved due to the specificity of its crosslinked structure, and the resin with the improved strength is significantly reflected in the improvement in the brittleness and strength of the phenol resin foam. .

That is, the phenolic resin foam according to the present invention has a brittleness of 30% or less and a thermal conductivity of 0.018 kca 1 Zm hr ° C or less, as is clear from the examples described later. An extremely excellent phenol resin foam can be provided. In the present invention, when specifying the resin structure, the pyrolysis of the foam sample is performed at 670 ° C. using a heating furnace type pyrolysis apparatus. Gas chromatography is measured by the method and conditions described later.

In the present invention, HFC having an ozone depletion potential of 0 and low thermal conductivity is used as a foaming agent. As the HFC, the ability to use HFCs having 1 to 8 carbon atoms <, and the thermal conductivity and economical reasons, HFCs having 2 carbon atoms are preferable. Specific examples include 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane, and 1,1,2,2-pentafluoroethane. Among them, 1,1,1,2-tetratetrafluoroethane is more preferred. These HFCs can be used as a mixture of two or more kinds. In addition, perfluorobutane, perfluorocyclobutane, perfluorocyclopentane, perfluorocyclopentane, perfluorocyclohexane, perfluorocyclohexane, perfluorocyclohexane, perfluoroheptane, etc. Fluorocarbons such as perfluorocycloheptane, perfluorooctane, and perfluorocyclooctane can also be used as a mixture. Furthermore, low-boiling substances such as nitrogen, helium, argon, and air can be used as foam nuclei dissolved in a foaming agent. Next, a method for producing the phenolic resin foam of the present invention will be described.

The phenolic resin foam according to the present invention foams and cures a resinous resin composition comprising a resinous resin and methylolated urea using fluorocarbon as a foaming agent to form a phenolic resin structure having a urea crosslinked structure. A method for producing a foam, characterized in that: This will be described in more detail below.

In general, in order to obtain a phenol resin foam with a high closed cell rate, the cell wall is not destroyed only by the vapor pressure of the volatile components such as the foaming agent, water, and formaldehyde in the resin composition during foaming. The viscosity of the resin composition and the reactivity of the resin to be cured before the foaming agent escapes from the foam are required. Since the factors that affect the viscosity of the resin composition are temperature and the degree of crosslinking of the resin, controlling the crosslinking reactivity of the resin is the most important void in forming an independent microcell structure. You can say it.

Resin resin for producing phenolic resin foam is heated from 40 ° C to 100 ° C in a temperature range of 40 ° C to 100 ° C using phenol and formaldehyde as raw materials using an aluminum catalyst. Polymerized. The curing reactivity of the resole resin greatly depends on the FZP ratio and the molecular weight. In general, the initial reaction is faster with a resin resin with a small F / P ratio, but the increase in viscosity in the latter half with the progress of the bridge is smaller. Regarding the molecular weight, the lower the molecular weight of the resin resin, the faster the initial reaction, but the increase in viscosity in the latter half as the crosslinking progresses becomes smaller. Therefore, besides the production examples shown here, it is possible to obtain the phenolic resin foam of the present invention by controlling the reactivity of the resole resin by optimizing the F / P ratio and the molecular weight distribution. Think.

The present inventors synthesized a resin resin having a high initial reactivity and a large viscosity increase in the latter half of the reaction, further mixed with methylolated urea to obtain a resole resin composition, and obtained the resole resin composition. A phenolic resin foam containing a urea crosslinked structure was obtained using the same. The amount of methylolated urea in the resole resin composition is not particularly limited, but is usually added to the resole resin in an amount of about 2 to about 40% by weight. The viscosity of the resin resin composition can be optimized by adjusting the amount of water. Although the viscosity of the resin composition varies depending on the foaming conditions, the viscosity at 40 ° C. is preferably from 100 to 5 OOOO cps, and more preferably from 200 to 300 cps. _c Mixing resole resin mixture with adjusted moisture, blowing agent, surfactant, curing catalyst The foamable composition can be obtained by introducing into a machine and mixing uniformly. Thereafter, the foaming composition is foamed and cured by heat treatment to obtain a phenol resin foam. As a curing catalyst for foaming and curing, toluene sulfonic acid, xylene sulfonate and the like can be used alone or in combination of two or more. Further, resornol, cresol, saligenin (0-methylolphenol), P-methylolphenol and the like may be added as a curing aid.

As the surfactant used in the present invention, any of the surfactants that are effective in producing a phenol resin foam can be used. In general, nonionic surfactants are effective, for example, alkylene oxide ゃ, which is a copolymer of ethylene oxide and propylene oxide, condensate of alkylene oxide and castor oil, or Condensation products of alkylenoxide with alkylphenols such as nonylphenol and dodecylphenol, fatty acid esters such as polyoxyethylene fatty acid esters, silicone-based compounds such as polydimethylsiloxane, and polyalcohols. No.

Next, a method for evaluating the structure, structure, and characteristics of the phenolic resin foam according to the present invention will be described.

The closed cell ratio of the phonol resin foam was measured as follows. A cylindrical sample of 35 to 36 mm in diameter cut out from phenolic resin foam with a cork borer is cut to a total thickness of 30 forces, 40 mm, and 40 mm, and an air-comparison hydrometer is used. The sample volume is measured according to the standard use method of Type 0 (manufactured by Tokyo Science). The value obtained by subtracting the volume of the cell wall calculated from the sample weight and the resin density from the sample volume and dividing it by the apparent volume calculated from the outer dimensions of the sample is expressed as ASTMD28.

It was measured according to 56. In the present invention, the density of the phenol resin was 1.27 g / cm ³ .

The average cell diameter of the phenolic resin foam according to the present invention is defined as the average cross-sectional diameter of the foam cross section of 50 times, and four straight lines of 9 cm length (actual length of 180 m) are drawn on the enlarged photograph. It is a value obtained by dividing 180 m by the average value of the number of bubbles crossed by a straight line.

This is an average value calculated from the number of cells measured according to 640.

Thermal conductivity of phenol resin foam sample 200 mm square, low temperature plate 5 ° C, high temperature plate The measurement was performed at 35 ° C according to the plate heat flow meter method of JISA 1412.

The density is a value obtained by measuring a weight and an apparent volume by removing a face material and a siding material from a phenol resin foam of 20 cm square as a sample, and was measured according to JISK722.

For the test piece for the brittle test, 12 cubes of 2.5 mm × 1.5 mm on a side were cut out so as to include a molded skin or face material on one side, and used as a sample. However, when the thickness of the foam was less than 25 mm, the thickness of the test piece was the thickness of the foam. Room temperature dried specific gravity 0.65, oak cubes with sides 1 9 ± 0.8 mm 2 4 cubes and 1 2 test specimens Inner dimensions that can be sealed so that dust does not come out of the box 1 9 1 Put it in a wooden box of X197 x X197 mm and make 600 ± 3 revolutions at 60 ± 2 revolutions per minute. After the rotation is completed, the contents of the box are transferred to a mesh with a nominal size of 9.5 mm, sieved to remove small pieces, the weight of the remaining test piece is measured, and the rate of reduction from the weight of the test piece before the test is calculated. The measured value was brittle, and was measured according to JISA 9511.

The compressive strength was measured according to JIS K7202 using a 50 mm square sample with a specified strain of 0.05.

The pyrogram of pyrolysis gas chromatography was measured as follows. For the phenolic resin foam sample used for measurement, the powder obtained by shaving the foam core portion from which the face material and siding material have been removed with a cutter knife, etc., is further carefully crushed in a mortar, and 0.3 to 0 for one measurement. The sample amount was adjusted within the range of 4 mg. As the thermal decomposition apparatus, PY210D manufactured by Frontier Lab Co., Ltd., which is a heating furnace type thermal decomposition apparatus, was used. The thermal decomposition was performed at 670 ° C. Gas chromatography was measured using Hewlett-Packard HP 5890 Type A, a non-polar liquid phase capillary column, Durab 0 nd DB-1 (0.25 mm ID, 0.25 mm film thickness). 25 m and a length of 30 m) were used. Carrier gas is helium (He). The total flow rate is 100 cc / min, the head pressure is 100 kPa, the oven temperature is 50 ° C, and the speed is 20 ° C / min. The temperature was raised to 34O 0 C and held for 15.5 minutes. The detection of each component was performed by a flame ionization detector (FID), and the area value of each peak was normalized with respect to all the detected components to obtain the ratio of each component. However, if the tails of the peaks overlap, the baseline is taken from the valley where the peaks overlap. The vertical line was lowered, and the area surrounded by the baseline and the vertical line was defined as the peak area. FIG. 1 shows an example of a gas chromatogram of a phenol resin foam sample according to the present invention. The structure of each component was confirmed by a mass spectrum obtained by introducing the component separated by gas chromatography into a mass spectrometer. The mass vector is JEOL JMS

The measurement was performed with an electron impact ionization method (EI method) at an ionization voltage of 70 eV and an ionization current of 300 mA using AX-505H. Figures 2 and 3 show the mass spectra of phenol and trimethylphenol.

The confirmation of the foaming agent can be performed as follows. A phenolic resin foam sample can be identified by immersing it in a solvent selected from pyridine, toluene, tetrahydrofuran (THF), dimethylformamide (DMF), etc., pulverizing it, extracting the foaming agent, and subjecting it to gas chromatography. If necessary, the components separated by gas chromatography can be introduced into a mass spectrometer to confirm the molecular structure. BEST MODE FOR CARRYING OUT THE INVENTION

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Synthesis of resole resin (A)]

In a reactor, 37% formaldehyde (Wako Pure Chemical Industries, special grade reagent) 5380 g and 99% phenol (Wako Pure Chemical Co., special grade reagent) 300 g were charged, and the propeller was rotated. Then, the temperature inside the reactor is adjusted to 40 ° C by a temperature controller. Next, 39 g of a 50% aqueous sodium hydroxide solution was added, and the reaction solution was heated from 40 ° C to 85 ° C and kept at 85 ° C for 2 hours. Then, cool the reaction solution to 5 ° C. This is designated as resol resin A-1.

Separately, 39 g of 37% formaldehyde, 540 g of water, 500 g of water and 39 g of a 50% aqueous sodium hydroxide solution were added to the reactor, and 800 g of urea (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) was prepared. Stir with a propeller rotary stirrer, and adjust the temperature inside the reactor to 40 ° C with a temperature controller. Next, the reaction solution was heated from 40 ° C. to 70 ° C. and held for 60 minutes. This is referred to as methylol urea A-2.

Next, the resulting resole resin Ai and methylol urea A-2 were all mixed together, and the liquid temperature was raised to 60 ° C. and maintained for one hour. The reaction was then cooled to 30 ° C. The mixture was neutralized with a 50% aqueous solution of paratoluenesulfonic acid monohydrate until the pH reached 5. The reaction solution was dehydrated at 60 ° C., and the viscosity was measured. The viscosity at 40 ° C. was 580 cps. This is referred to as Resin Resin A.

[Synthesis of Resin Resin (B)]

Resin B was synthesized in the same manner as Resin A except that the weight ratio of A-2 to A-1 in Resin A was changed to 0.05. Was.

[Synthesis of Resin Resin (C)]

Resin Resin C was synthesized in the same manner as Resin Resin A except that the weight ratio of A-2 to A-1 in Resin Resin A was changed to 0.49. Was.

[Synthesis of Resin Resin (D)]

A reactor was charged with 37% formaldehyde 43,050 g and 99% ethanol 300,000 g, stirred with a propeller rotary stirrer, and the temperature inside the reactor was adjusted to 50 with a temperature controller. Adjust to ° C. Next, 60 g of a 50% aqueous sodium hydroxide solution was added, and the temperature of the reaction solution was kept at 50 ° C. to 55 ° C. for 20 minutes. Thereafter, the temperature was raised to 85 ° C, and after the temperature reached 85 ° C, the temperature was maintained for 130 minutes. Thereafter, the reaction solution was cooled to 5 ° C. This is referred to as Resin Resin D-1.

Resole resin D was synthesized in the same manner as resole resin A except that resole resin A-1 in the synthesis of resole resin A was changed to D-1.

[Synthesis of resole resin (E)]

A reactor was charged with 37% formaldehyde 26 13 g and 99% ethanol 18 36 g, stirred with a propeller rotary stirrer, and the temperature inside the reactor was adjusted to 50 with a temperature controller. Adjust to ° C. Then, 36.3 g of a 50% aqueous sodium hydroxide solution was added, and the reaction solution was kept at a temperature in the range of 50 ° C to 55 ° C for 20 minutes. Thereafter, the temperature was raised to 85 ° C, and was maintained for 130 minutes after the temperature reached 85 ° C. Then, the reaction solution is

The mixture was cooled to 30 ° C. and neutralized with a 50% aqueous solution of paratoluenesulfonic acid monohydrate until the value became 5. After dehydrating the reaction solution at 60 ° C and measuring the viscosity,

The viscosity at 40 ° C. was 270 cps. This is called resin resin E _c [Synthesis of Resin Resin (F)]

A reactor was charged with 37% formaldehyde (317.4 g) and 99% phenol (1600 g), stirred by a propeller rotary stirrer, and the temperature inside the reactor was adjusted to 50 ° by a temperature controller. Adjust to C. Next, 34.1 g of a 50% aqueous sodium hydroxide solution was added, and the reaction solution was maintained at a temperature in the range of 50 ° C to 55 ° C for 20 minutes. Thereafter, the temperature was raised to 85 ° C, and was held for 105 minutes after the temperature reached 85 ° C. Then, the reaction solution is

The mixture was cooled to 30 ° C and neutralized with a 50% aqueous solution of paratoluenesulfonic acid monohydrate until ^ 1 became 5. After dehydrating the reaction solution at 60 ° C and measuring the viscosity,

The viscosity at 40 ° C. was 1300 cps. This is designated as Resin Resin F.

[Synthesis of Resin Resin (G)]

Resin Resin G was synthesized in the same manner as Resole Resin A except that the weight ratio of A-2 to A_1 in Resin Resin A was changed to 0.01.

[Synthesis of Resin Resin (H)]

A reactor was charged with 33% formaldehyde 333.3 g and 99% ethanol 300 g, stirred by a propeller rotary stirrer, and the temperature inside the reactor was adjusted to 40 ° by a temperature controller. Adjust to C. Next, 57 g of a 50% aqueous sodium hydroxide solution was added, and the reaction solution was heated from 40 ° C. to 85 ° C. and held for 2 hours and 30 minutes. Then, cool the reaction solution to 5 ° C. This is designated as Resin Resin H-1.

Resin resin H was synthesized in the same manner as resole resin A except that resole resin A-1 in resole resin A was changed to resole resin H-1.

[Synthesis of Resin Resin (I)]

Resin Resin I was synthesized in the same manner as Resin Resin D except that the weight ratio of methylol urea A-2 to Resole Resin D-1 was changed to 0.012. Resin I was obtained.

[Synthesis of resole resin (J)]

A reactor was charged with 37% formaldehyde (317.4 g) and 99% phenol (1600 g), and stirred with a propeller rotary stirrer. Adjust JP 8 degrees to 50 ° C. Next, 34.1 g of a 50% aqueous sodium hydroxide solution was added, and the reaction solution was kept at 50 ° C. to 55 ° C. for 20 minutes. Thereafter, the temperature was raised to 85 ° C, and after the temperature reached 85 ° C, the temperature was maintained for 150 minutes. Then, cool the reaction solution to 5 ° C. This is referred to as Resin Resin J-1.

In the synthesis of Resole Resin J, Resole Resin A was changed to Resin Resin A-i to J-11, and the weight ratio of methylol urea A-2 was changed to 0.96. In the same manner as in A, a resin resin J was obtained.

(Example 1)

Dissolve the polysiloxane-based non-ionic surfactant SH-193 (manufactured by Toray Silicone Co., Ltd.) in Resole Resin A at a ratio of 3.5 g to 100 g of Resole Resin. A mixture of the resole resin mixture, HF C-134a (manufactured by Daikin Industries, Ltd.) 99.5% by weight and nitrogen 0.5% by weight as a foaming agent, and para-toluenesulfonic acid monohydrate as a curing catalyst A mixture of 50% Japanese product (95% pure Wako Pure Chemicals) and 50% diethylene glycol (98% pure Wako Pure Chemicals), 100 parts resin mixture, 17 parts foaming agent, 17 parts curing catalyst Five parts were supplied to a pin mixer equipped with a temperature control jacket. At this time, the mixer jacket was adjusted to 40 ° C and the internal pressure of the mixer was 15 kgZcm. The mixture coming out of the mixer is poured into a formwork laid with Spunbond E 104 (made by Asahi Kasei Corporation), and then put in an oven at 85 ° C for 5 hours to obtain a phenol resin foam. Was.

The ratio of trimethylphenol in the piezogram in the pyrolysis gas chromatography of the obtained phenol resin foam to the ratio of trimethylphenol A to the ratio of phenol in the decomposition product B, C, the component derived from urea crosslinking D, and the phenol derivative Table 1 shows the ratio F of component E and the measurement results of the closed cell ratio, average cell diameter, density, thermal conductivity, brittleness, and compressive strength.

(Example 2)

Example 1 was repeated except that a mixture of 20% of paratoluenesulfonic acid monohydrate, 50% of diethyleneglycol monoole, and 30% of resorcinol was used as a curing catalyst in a ratio of i 2 parts to 100 parts of resin. In the same manner, a phenol resin foam was produced. Table 1 shows the measurement results of the obtained funinol resin foam.

(Example 3) A phenolic resin foam was produced in the same manner as in Example 1, except that 3% by weight of PF-5500 (3M Perfluoropentane) was added to HFC-134a as a foaming agent.

Table 1 shows the measurement results of the obtained phenol resin foam.

(Comparative Example 1)

A phenol resin foam was produced in the same manner as in Example 1 except that the resin A was changed to the resin E.

Table 1 shows the measurement results of the obtained phenol resin foam.

(Comparative Example 2)

A phenol resin foam was produced in the same manner as in Example 1 except that the resin A was changed to the resin E and 5 parts by weight of urea was added to 100 parts by weight of the resin. In such a case, almost no foaming agent was removed at the time of curing, and the foam was not formed.

Table 1 shows the measurement results of the obtained phenol resin foam.

(Comparative Example 3)

A phenolic resin foam was produced in the same manner as in Example 1 except that the resin A was changed to the resin F.

Table 1 shows the measurement results of the obtained phenol resin foam.

(Comparative Example 4)

Changed resin resin A to resole resin F, added 100 parts by weight of urea to 100 parts by weight of resin, and changed the curing agent to 25 parts by weight with respect to 100 parts by weight of resin A phenolic resin foam was produced in the same manner as in Example 1 except for the above.

Table 1 shows the measurement results of the obtained phenol resin foam.

(Examples 4-6, Comparative Examples 5-8)

In Examples 4 to 6 and Comparative Examples 5 to 8, as in Examples 1 to 4, the resin shown in Table 1 was used as the resin, and the number of catalyst parts was adjusted. A phenolic resin foam was produced.

In the phenolic resin foam samples obtained in each Example and Comparative Example, the ratio A of trimethylphenol in the pyrogram of pyrolysis gas chromatography and the decomposition products Ratio of phenol to B Ratio of C to urea crosslinking component D to phenol derivative Component E Ratio of F value and closed cell rate of foam, average cell diameter, density, thermal conductivity, brittleness and compressive strength See Table 1.

table 1

However, C value: area ratio of trimethylphenol in the pyrolyzate to phenol (C = AZB)

F value: Area ratio of component D derived from urea cross-linking in pyrolyzate to cellulose derivative component E (F = DZE)

Industrial applicability

The foam of the present invention has excellent heat insulation performance, is excellent in mechanical strength such as compressive strength, and has improved surface brittleness, so that it is suitable as a heat insulating material for buildings, and has a foam that does not cause ozone layer destruction. It is compatible with the global environment because of the use of chemicals.

Claims

The scope of the claims

1. closed cell ratio 70% or more, the average cell diameter 1 0 am or 4 0 0 m or less, or less density 1 0 kg / m ³ or more 7 0 kg / m ^3, containing Furuoro hydrocarbon in closed cells A phenolic resin foam having a phenolic resin structure having a urea crosslinked structure.

2. In the pyrolysis pattern of pyrolysis gas chromatography of the phenolic resin, the ratio of the trimethylphenol of the pyrolysis product A to the ratio of the phenol to the phenol B of the pyrolysis product = A / B is not less than 0.2 and not more than 4.0, and the ratio of component D derived from urea crosslinking of thermal decomposition product to phenol derivative component E is F = D / E force \ 0.03 or more 2. The phenolic resin foam according to claim 1, wherein the phenolic resin foam is at most 0.3.

3. The phenolic resin foam according to claim 1 or 2, wherein the thermal conductivity is 0.018 kca1 Zmhr r ° C or less, and the brittleness is 30% or less.

4. The fluorocarbon is at least one of 1,1,1,2-tetrafluoroethane or 1,1-difluoroethane, or 1,1,1,2,2-pentafluoroethane. 4. The phenolic resin foam according to claim 1, wherein the phenolic resin foam is of a type.

5. A resole resin composition consisting of a resole resin and methylolated urea is foamed and cured using fluorocarbon as a foaming agent to form a urea crosslinked structure. The closed cell rate is 80% or more, and the average cell diameter is 2 0 // m or more 3 0 0 m or less, density 20 kg / m 3 or more 50 kg / m ³ or less, thermal conductivity 0.0 1 8 kca 1 / mh r ° C or less, brittleness 30% or less A fuminol resin foam, characterized in that: