JP2011016919A - Expandable resol-type phenol resin molding material and phenol resin foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expandable phenol resin molding material providing an excellent phenol resin foam with excellent mechanical strengths, especially compression strength, and to provide a phenol resin foam with such characteristics.SOLUTION: The expandable resol-type phenol resin molding material, containing a liquid resol-type phenol resin, a foaming agent, a foam-stabilizer, and an acid curing agent, further includes an epoxy resin compound as an additive.

Description

  The present invention relates to a foamable resol-type phenol resin molding material and a phenol resin foam using the same. More specifically, the present invention relates to a foamable resol-type phenol resin molding material that gives a phenol resin foam excellent in strength, and a phenol resin foam having the above-mentioned properties obtained by foaming and curing the same.

2. Description of the Related Art Conventionally, phenol resin foams are excellent in heat insulation, flame retardancy, fire resistance, and the like, and are therefore used as heat insulation materials in construction and other industrial fields.
Phenolic resin foam is used for various applications, but depending on the application, high mechanical properties may be required, and as a phenolic resin foam with excellent mechanical strength, liquid resol type phenolic resin, foam A material using a molding material containing an agent, a foam stabilizer and an acid curing agent and containing a nitrogen-containing crosslinked cyclic compound has been proposed (see Patent Document 1).
However, further reduction in thickness and density are required for workability and cost reduction, and further increase in strength has been required to compensate for the decrease in mechanical strength due to reduction in thickness and density. .

JP 2006-335868 A

  Under such circumstances, the object of the present invention is to provide a foamable phenol resin molding material that gives a phenol resin foam excellent in mechanical strength, particularly compressive strength, and a phenol resin foam having the above characteristics. There is.

  As a result of intensive studies to develop a foamable phenolic resin molding material having the above-mentioned properties, the present inventors have found that a foamable resol type containing a liquid resol type phenolic resin, a foaming agent, a foam stabilizer, and an acid curing agent. In the phenol resin molding material, it has been found that the epoxy resin compound further contained in the material as an additive contributes to solving the problems, and the present invention has been made based on this finding.

That is, the present invention
(1) In a foamable resol type phenol resin molding material containing a liquid resol type phenol resin, a foaming agent, a foam stabilizer and an acid curing agent, an foamable resole further containing an epoxy resin compound as an additive Type phenolic resin molding material,
(2) The foamable resol-type phenol resin molding material according to (1) above, wherein the epoxy resin compound is a liquid epoxy resin having a viscosity of 25,000 mPa · s or less,
(3) The foamable resol-type phenol resin molding material according to (1) or (2) above, wherein the epoxy resin compound is a condensed epoxy resin of polyhydric phenol and epichlorohydrin,
(4) The foamable resol-type phenol resin molding material as described in (3) above, wherein the polyphenol is bisphenol A;
(5) The foamable resol type phenol resin according to any one of the above (1) to (4), which contains 0.5 to 5 parts by mass of an epoxy resin compound per 100 parts by mass of the liquid resol type phenol resin. Molding material,
(6) Furthermore, at least one additive selected from a plasticizer, an inorganic filler, and a nitrogen-containing cross-linked cyclic compound is contained, any one of (1) to (5) above Foamable resol type phenolic resin molding material,
(7) A phenol resin foam obtained by foam-curing the foamable resol-type phenol resin molding material according to any one of the above (1) to (6) is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the foamable resol type phenol resin molding material which gives the phenol resin foam excellent in mechanical strength, especially compressive strength, and the phenol resin foam which has the said characteristic can be provided.

First, the foamable resol type phenol resin molding material of the present invention will be described.
The foamable resol-type phenolic resin molding material of the present invention comprises a liquid resol-type phenolic resin, a foaming agent, a foam stabilizer, an acid curing agent, an epoxy resin compound, and a plasticizer, inorganic filler, and nitrogen-containing cross-linking type that are used as appropriate. Includes cyclic compounds.

  The liquid resol type phenol resin is not particularly limited, but preferably phenols such as phenol, cresol, xylenol, paraalkylphenol, paraphenylphenol, resorcin, and modified products thereof, and aldehydes such as formaldehyde, paraformaldehyde, furfural, and acetaldehyde Is used in the presence of an alkali such as sodium hydroxide, potassium hydroxide or calcium hydroxide, or an aliphatic amine such as trimethylamine or triethylamine. The ratio of the phenols and aldehydes used is not particularly limited, but is usually 1: 1 to 1: 3, preferably 1: 1.5 to 1: 2.5, more preferably 1: 1.8 by molar ratio. ˜1: 2.5, particularly preferably in the range of 1: 1.6 to 1: 2.1.

  Examples of the blowing agent include propane, butane, pentane, isopentane, hexane, heptane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane and other low-boiling hydrocarbons, ethers such as isopropyl ether, trichloromonofluoromethane, Those containing an organic non-reactive foaming agent such as halogenated hydrocarbons such as trichlorotrifluoroethane and isopropyl chloride, or a mixture of these compounds are used. Here, the non-reactive foaming agent refers to a substance that can volatilize itself under foaming conditions to foam the phenol resin. In addition to the foaming agent, a gas such as nitrogen gas, oxygen gas, argon gas, carbon dioxide gas, or a mixed gas thereof may be used.

  The content of the foaming agent in the foamable resol type phenol resin molding material is usually 1 to 20 parts by mass, preferably 5 to 10 parts by mass with respect to 100 parts by mass of the liquid resol type phenol resin. Good.

Examples of the foam stabilizer include castor oil, castor oil derivatives, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene glycol, polysiloxane compounds, and polyoxyethylene sorbitan fatty acid esters. These may be used individually by 1 type and may be used in combination of 2 or more type.
As the castor oil derivative, a castor oil alkylene oxide adduct is preferable. As the castor oil alkylene oxide adduct, castor oil ethylene oxide (hereinafter, abbreviated as “EO”) adduct and castor oil propylene oxide adduct are preferable. In the castor oil alkylene oxide adduct, alkylene oxide, especially EO, is preferably added in an amount of more than 20 moles, less than 40 moles, especially 21 to 38 moles per mole of castor oil. And a hydrophilic group mainly composed of a polyoxyalkylene group such as a polyoxyethylene group formed by an alkylene oxide such as EO having a predetermined addition mole are arranged in a balanced manner in the molecule. In addition, the surface active ability is excellent, the bubble diameter of the phenol resin foam is kept small, and the bubble wall is given flexibility, thereby preventing the occurrence of cracks in the bubble wall. Since it plays, it is preferable.
Examples of the polysiloxane compounds include dimethylpolysiloxane-polyoxyalkylene copolymers, dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymers, and the like.

  The content of the foam stabilizer in the foamable resol type phenol resin molding material is preferably 1 to 5 parts by mass, more preferably 2 to 4 parts by mass per 100 parts by mass of the liquid resol type phenol resin. . When the content is less than 1 part by mass, the bubbles are difficult to be uniformly reduced. When the content exceeds 5 parts by mass, the water absorption of the produced phenolic resin foam is increased and the production cost is increased.

  Examples of the acid curing agent include inorganic acids such as sulfuric acid and phosphoric acid, and organic acids such as benzenesulfonic acid, ethylbenzenesulfonic acid, paratoluenesulfonic acid, xylenesulfonic acid, naphtholsulfonic acid, and phenolsulfonic acid. These acid curing agents may be used alone or in combination of two or more.

  The content of the acid curing agent in the foamable resol type phenol resin molding material is preferably 6 to 25 parts by mass, more preferably 10 to 20 parts by mass per 100 parts by mass of the liquid resol type phenol resin. . When the content is less than 6 parts by mass, the curing is slow, so that the curing may be insufficient, or the bubbles may be broken and become open cells, and even if the content exceeds 25 parts by mass, the curing becomes too fast. In some cases, strain remains in the foam, and shrinkage after molding may increase.

The epoxy resin compound is preferably obtained by condensing a polyhydric phenol and epichlorohydrin in an arbitrary ratio, and as such, depending on the type of polyhydric phenol, a combination of bisphenol and epichlorohydrin may be used. A type, bisphenol F type, bisphenol AD type, phenol novolak type, cresol novolak type and the like can be mentioned. These epoxy resin compounds may be used individually by 1 type, and may be used in combination of 2 or more type. A bisphenol A type epoxy resin compound is particularly preferable from the viewpoint of availability and cost.
Further, the viscosity of the epoxy resin compound is desirably lower from the viewpoint of mixing with the phenol resin, preferably 25000 mPa · s or less, and more preferably 15000 Pa · s or less.

  The content of the epoxy resin compound in the foamable resol type phenol resin molding material is preferably in the range of 0.5 to 5 parts by mass, more preferably 1 to 3 parts by mass per 100 parts by mass of the liquid resol type phenol resin. That's fine. If this content is less than 0.5 parts by mass, it will be difficult to obtain a foam having sufficient compressive strength and elastic modulus, and if it exceeds 5 parts by mass, the curing of the phenolic resin will be delayed and there will be a problem in moldability. And the manufacturing cost increases.

Examples of the additive component that can be appropriately blended in the molding material of the present invention include a plasticizer, an inorganic filler, and a nitrogen-containing crosslinked cyclic compound.
Preferred examples of the plasticizer include polyester polyol, polyethylene glycol and the like, and these may be used alone or in combination of two or more. The plasticizer imparts flexibility to the cell walls of the phenol resin foam, suppresses the deterioration of the cell walls over time, and contributes to improving the long-term stability of the heat insulation. A polyester polyol having a weight average molecular weight of 200 to 10,000, particularly 200 to 5,000 is preferable from the viewpoint of imparting flexibility to the cell walls of the phenol resin foam.

（式中、Ａは二価カルボン酸残基であり、Ｒは二価アルコール残基であり、ｎは１または１を越える整数である。）
で表されるものが好ましく、これらは１種を単独で用いてもよいし、２種以上を組み合わせて用いてもよい。 As the polyester polyol, a reaction product of a polyvalent carboxylic acid and a polyhydric alcohol, for example, a polybasic carboxylic acid selected from divalent to tetravalent carboxylic acids, a polyhydric alcohol selected from divalent to pentavalent alcohols, and Reaction products of the general formula (I)

(In the formula, A is a divalent carboxylic acid residue, R is a dihydric alcohol residue, and n is 1 or an integer greater than 1.)
These are preferable, and these may be used alone or in combination of two or more.

  In the general formula (I), examples of a preferable divalent carboxylic acid that forms the residue A include an aromatic divalent carboxylic acid, an aliphatic divalent carboxylic acid, and an alicyclic divalent carboxylic acid. Phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,3-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacine Acid, cyclohexane-1,2-dicarboxylic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid and the like.

  The dihydric alcohol that forms the skeleton R is an aromatic glycol, an aliphatic glycol, or an alicyclic glycol, such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1, 5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, cyclopentane-1,2-diol, cyclo Pentane-1,2-dimethanol, cyclohexane-1,2-diol, cyclohexane-1,3-diol, cyclohexane-1,4-diol, cyclopentane-1,4-dimethanol, 2,5-norbornanediol, etc. Is an aliphatic group Calls and alicyclic glycols are especially preferred.

A preferred plasticizer for the phenolic resin foam of the present invention has a molecular structure including both one ester skeleton and one hydroxyl group, and has hydrophilic properties similar to the phenolic resin foam. The phenol resin and the plasticizer are compatible with each other and can form a uniform resin solution. Further, the phenol resin foam is imparted with flexibility to the cell wall of the phenol resin foam. Deterioration phenomena such as the occurrence of cracks are suppressed, and long-term stability of the thermal conductivity of the phenol resin foam is brought about.
When a plasticizer is contained in the foamable resol type phenol resin molding material, the content of the plasticizer in the molding material is usually 0.5 to 10 parts by mass with respect to 100 parts by mass of the liquid resol type phenol resin. The range of 1 to 5 parts by mass is preferable.

Examples of inorganic fillers include calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, calcium silicate, magnesium hydroxide, aluminum hydroxide, mica, talc, bentonite, zeolite, silica gel, aluminum oxide, titanium oxide, and antimony oxide. Can be mentioned. These may be used individually by 1 type and may be used in combination of 2 or more type. The inorganic filler makes it possible to give a phenol resin foam having low acidity and improved fire resistance.
When an inorganic filler is contained in the foamable resol type phenol resin molding material, the content of the inorganic filler in the molding material is usually 0.5 to 20 parts by mass with respect to 100 parts by mass of the liquid resol type phenol resin. The range of 1 to 10 parts by mass is preferable.

Examples of the nitrogen-containing bridged cyclic compound include quinuclidine, pyridine, hexamethylenetetramine and the like. These may be used alone or in combination of two or more. Of these, hexamethylenetetramine is preferred from the standpoints of effects and availability. By including this nitrogen-containing crosslinked cyclic compound in the foamable resol-type phenol resin molding material, the obtained phenol resin foam is improved in mechanical strength and brittleness and imparted with corrosion resistance.
When the nitrogen-containing crosslinked cyclic compound is contained in the foamable resol-type phenolic resin molding material, the content of the nitrogen-containing crosslinked cyclic compound in the molding material is as described above from the viewpoint of balance between effect and economy. The amount may be in the range of usually 0.1 to 15 parts by mass, preferably 0.1 to 10 parts by mass, more preferably 0.3 to 7 parts by mass with respect to 100 parts by mass of the liquid resol type phenol resin.

  The foamable resol-type phenolic resin molding material of the present invention is, for example, the above-mentioned liquid resol-type phenolic resin, foam stabilizer, epoxy resin compound, and further, if necessary, inorganic filler, plasticizer, nitrogen-containing cross-linked cyclic A compound can be added and mixed, and after adding a foaming agent and an acid curing agent to the mixture, the composition is supplied to a mixer, heated or cooled as appropriate, and stirred.

Next, the phenol resin foam of the present invention will be described.
The phenol resin foam of the present invention is obtained by foam-curing the foamable resol type phenol resin molding material of the present invention prepared as described above.
As a method for forming this phenol resin foam, for example, (1) a molding method of flowing out on an endless conveyor, (2) a method of partially flowing out by spotting, (3) pressure foaming in a mold (4) a method of making a foam block by putting it in a large space, and (5) a method of filling and foaming while press-fitting into a cavity.

  As a preferable method, the foamable resol-type phenol resin molding material is discharged onto a continuously moving carrier, and the discharged material is foamed and molded through a heating zone to obtain a desired phenol resin foam. The method of producing is mentioned. Specifically, the foamable resol-type phenolic resin molding material is discharged onto a face material on a conveyor belt, and then the face material is placed on the upper surface of the molding material on the conveyor belt and placed in a curing furnace. Inside, hold down with another conveyor belt from above and adjust the phenolic resin foam to a predetermined thickness, preferably 100 ° C. or less, more preferably 90 ° C. or less, especially 60 to 80 ° C., for about 2 to 20 minutes. It is better to foam and cure under conditions. The phenolic resin foam exiting the curing furnace is cut into a predetermined length.

  The face material is not particularly limited and is generally natural fiber, synthetic fiber such as polyester fiber or polyethylene fiber, non-woven fabric such as inorganic fiber such as glass fiber, paper, aluminum foil-clad nonwoven fabric, metal plate, metal Foil etc. are used, but glass fiber nonwoven fabric, spunbond nonwoven fabric, aluminum foil tension nonwoven fabric, metal plate, metal foil, plywood, structural panel, particle board, hard board, wood cement board, flexible board, perlite board, silicic acid Calcium plate, Magnesium carbonate plate, Pulp cement plate, Shizing board, Medium density fiber board, Gypsum board, Lath sheet, Volcanic glass composite plate, Natural stone, Brick, Tile, Glass molded body, Lightweight cellular concrete molded body, Cement mortar Water for molded products, glass fiber reinforced cement molded products, etc. Molded body the resistance cement hydrate as a binder component are preferred. These may be used individually by 1 type and may be used in combination of 2 or more type. This face material may be provided on one side of the phenol resin foam or may be provided on both sides. Moreover, when providing in both surfaces, a face material may be the same and may differ. Further, it may be provided later by using an adhesive.

The phenol resin foam obtained as described above is then preferably post-cured for drying and the like. The post-curing treatment also serves as curing, and is performed, for example, at a temperature in the range of 70 to 90 ° C. with a dryer. The post-curing treatment time depends on the thickness of the phenolic resin foam, the post-curing treatment temperature, etc., and cannot be generally defined, but is selected so as to obtain a phenol resin foam having predetermined physical properties described below, Generally, it is about 1.0 to 6.0 hours.
Moreover, if the post-curing treatment temperature is in the above range, it is possible to obtain a phenol resin foam having a good appearance in which damage to the cell walls is suppressed and swelling, shrinkage, discoloration, and the like are suppressed.

In the phenolic resin foam of the present invention, the average cell diameter is preferably 5 to 400 μm, especially 50 to 200 μm, and preferably the void area ratio in the cross-sectional area of the foam is 5% or less, Among them, 2% or less is the well, also, preferably a density of 10 kg / ^{m 3} or more and preferably 20 and 100 kg / ^{m 3} and it's good, also preferably have an elastic modulus of 20% or less, preferably 10 to 18 % Should be good.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, the performance and physical property of the phenol resin foam obtained in each example were measured according to the method shown below.

(1) Density Measured according to JIS A 9511.

(2) Compressive strength Measured according to JIS A 9511.

Example 1
Liquid resol type phenolic resin (product number: PF-339 manufactured by Asahi Organic Materials Co., Ltd.) 100 parts by mass of ion-exchanged water added to 1 part by mass to adjust viscosity, phthalic acid and diethylene glycol as a plasticizer in a molar ratio of 1 : 3 parts by weight of polyester polyol reacted in 2, 3 parts by weight of castor oil EO adduct (addition mole number 30) as a foam stabilizer, and bisphenol A type epoxy resin (product of Toto Kasei, product number: YD-128) as an epoxy resin compound Viscosity: 15000 mPa · s) 2 parts by mass were added and mixed.
With respect to 109 parts by mass of this phenol resin mixture, 8 parts by mass of normal pentane was added as a foaming agent, and 14 parts by mass of a mixture of p-toluenesulfonic acid: xylenesulfonic acid mass ratio = 2: 1 was added as an acid curing agent, followed by stirring. These were mixed to prepare a foamable resol-type phenol resin molding material.
Each of these molding materials is discharged into a mold and heat-molded in a dryer at 75 ° C. for 300 seconds. Then, the molded product is taken out from the mold and placed in a dryer at 85 ° C. and cured for 5 hours. A foam was made.
Table 1 shows the performance and physical properties of the phenol resin foam thus obtained.

Comparative Example 1
In Example 1, a molding material was prepared and a foam was produced in the same manner as in Example 1 except that the epoxy resin compound was not used. The performance and physical properties of the foam are shown in Table 1.

  As can be seen from Table 1, the phenol resin foams obtained from the molding materials of the examples are superior in mechanical strength, particularly compressive strength, as compared with the comparative examples.

  The foamable resol-type phenol resin molding material of the present invention is very useful in industry because it can provide a phenol resin foam excellent in mechanical strength, particularly compressive strength.

Claims (7)

  In a foamable resol type phenol resin molding material containing a liquid resol type phenol resin, a foaming agent, a foam stabilizer, and an acid curing agent, an expandable resole type phenol resin further containing an epoxy resin compound as an additive Molding material.   2. The foamable resol-type phenol resin molding material according to claim 1, wherein the epoxy resin compound is a liquid epoxy resin having a viscosity of 25000 mPa · s or less.   The foamable resol type phenol resin molding material according to claim 1 or 2, wherein the epoxy resin compound is a condensed epoxy resin of polyhydric phenol and epichlorohydrin.   4. The foamable resol-type phenol resin molding material according to claim 3, wherein the polyphenol is bisphenol A.   The foamable resol type phenol resin molding material according to any one of claims 1 to 4, comprising 0.5 to 5 parts by mass of an epoxy resin compound per 100 parts by mass of the liquid resol type phenol resin.   The foamable resol-type phenol according to any one of claims 1 to 5, further comprising at least one additive selected from a plasticizer, an inorganic filler, and a nitrogen-containing crosslinked cyclic compound. Resin molding material.   A phenol resin foam obtained by foam-curing the foamable resol-type phenol resin molding material according to claim 1.