JP5385634B2 - Foamable resol-type phenolic resin molding material and phenolic resin foam - Google Patents

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 improved in brittleness, and a phenol resin foam having the above-mentioned properties obtained by foaming and curing the same. It is.

  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 foams are often used in various applications, but depending on the application, high mechanical properties, particularly those with low brittleness may be required. Conventionally, as a phenolic resin foam excellent in mechanical strength and brittleness, a resin material containing a liquid resol type phenolic resin, a foaming agent, a foam stabilizer and an acid curing agent and a molding material containing a nitrogen-containing crosslinked cyclic compound is used. It has been proposed (see Patent Document 1).

  However, in order to improve the mechanical strength and brittleness of the liquid resol type phenol resin by the nitrogen-containing crosslinked cyclic compound, it is necessary to disperse the nitrogen-containing crosslinked cyclic compound as uniformly as possible in the molding material. The nitrogen-containing bridged cyclic compound is a solid substance at room temperature, and is a substance that easily absorbs moisture and becomes a lump, and thus it has been difficult to uniformly disperse.

JP 2006-335868 A

  Under such circumstances, the present invention provides a foaming phenol that uniformly disperses a nitrogen-containing crosslinked cyclic compound in a liquid resol type phenolic resin and provides a phenolic resin foam having excellent strength and improved brittleness. It aims at providing the resin molding material and the phenol resin foam which has the said characteristic.

  As a result of intensive studies to develop a foamable phenolic resin molding material having the above-mentioned properties, the present inventors have previously dissolved a nitrogen-containing crosslinked cyclic compound additive in an organic solvent such as furfuryl alcohol. Thus, it has been found that the object can be achieved, and the present invention has been completed based on this finding.

That is, the present invention
(1) In a foamable resol-type phenolic resin molding material containing a liquid resol-type phenolic resin, a foaming agent, a foam stabilizer, an acid curing agent and a nitrogen-containing crosslinked cyclic compound additive, the nitrogen-containing crosslinked cyclic compound is added. Foamable resol-type phenolic resin molding material, characterized in that the agent is dissolved in furfuryl alcohol ,

(2) The foamable resol-type phenol resin molding material according to (1) above, containing 0.1 to 10 parts by weight of a nitrogen-containing crosslinked cyclic compound additive per 100 parts by weight of the liquid resol-type phenol resin,
(3) The foamable resol-type phenol resin molding material according to the above (1) or (2) , wherein the nitrogen-containing bridged cyclic compound is at least one selected from quinuclidine, pyridine and hexamethylenetetramine,
(4) A phenol resin foam obtained by foaming and curing the foamable resol-type phenol resin molding material according to any one of (1) to (3 ) above is provided.

  According to the present invention, there is provided a foamable phenol resin molding material that provides a phenol resin foam having excellent strength, improved brittleness, and a small amount of acid curing agent, and a phenol resin foam having the above characteristics. be able to.

  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, a nitrogen-containing crosslinked cyclic compound additive, and optionally a plasticizer and an inorganic filler. Is included.

  The liquid resol-type phenol resin comprises phenols such as phenol, cresol, xylenol, paraalkylphenol, paraphenylphenol, and resorcin, and modified products thereof, and aldehydes such as formaldehyde, paraformaldehyde, furfural, and acetaldehyde. A phenol resin obtained by adding a catalytic amount of an alkali such as potassium hydroxide or calcium hydroxide and reacting the same is not limited thereto. The ratio of the phenols and aldehydes used is not particularly limited, but is usually about 1.0: 1.5 to 1.0: 3.0, preferably 1.0: 1.8 to 1.0 in molar ratio. : 2.5.

  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 this invention, the usage-amount of the said foaming agent is 1-20 weight part normally with respect to 100 weight part of the above-mentioned liquid resol type phenol resin, Preferably it is 5-10 weight part.

  In addition to the blowing agent, a gas such as nitrogen gas, oxygen gas, argon gas, carbon dioxide gas, or a mixed gas thereof may be used.

  As the foam stabilizer, one containing castor oil ethylene oxide (hereinafter, ethylene oxide is abbreviated as “EO”) adduct is preferably used.

  Castor oil is a non-drying oil obtained by pressing from seeds such as castor sesame, and mainly contains unsaturated acids such as ricinoleic acid, oleic acid and linoleic acid, and small amounts of saturated acids such as stearic acid and dioxystearic acid. Is included.

  In the said foam stabilizer, what added EO more than 20 mol and less than 40 mol with respect to 1 mol of said castor oil is suitable.

  The reason why the added mole number of EO is more than 20 moles and less than 40 moles is that when the added mole number of EO is more than 20 moles and less than 40 moles, a hydrophobic group mainly composed of a long-chain hydrocarbon group of castor oil And a hydrophilic group mainly composed of polyoxyethylene groups formed by EO of more than 20 moles and less than 40 moles are arranged in a balanced manner in the molecule, and a good surface activity can be obtained. By using a castor oil EO adduct having surface activity, the bubble diameter of the phenol resin foam is kept small, the flexibility is given to the bubble wall, and cracking of the bubble wall is prevented. This is because an effect can be obtained. The added mole number of EO is more preferably 21 to 38 moles.

  In the present invention, the castor oil EO adduct is used as a suitable component as the foam stabilizer, but in addition to this, a dimethylpolysiloxane-polyoxyalkylene copolymer, a dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymer. Polymers, castor oil propylene oxide adducts, and the like can also be used.

  Further, the content of the castor oil EO adduct in the foamable phenolic resin molding material is preferably 1 to 5 parts by weight, more preferably 2 to 4 parts by weight, per 100 parts by weight of the phenol resin. When the content of the castor oil EO adduct is less than 1 part by weight, the bubbles are difficult to be uniformly reduced. On the other hand, when the content exceeds 5 parts by weight, the water absorption of the produced phenolic resin foam is increased and the production cost is increased. Becomes higher.

  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.

  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.

  The amount of the nitrogen-containing crosslinked cyclic compound added is preferably 0.1 to 10 parts by weight, more preferably 100 parts by weight with respect to 100 parts by weight of the liquid resol type phenolic resin, from the viewpoint of balance between effect and economy. Is 0.3 to 7 parts by weight.

As an organic solvent capable of dissolving the nitrogen-containing crosslinked cyclic compound, furfuryl alcohol is used from the viewpoint of solubility and safety.
The amount of the nitrogen-containing crosslinked cyclic compound dissolved in furfuryl alcohol is preferably 10 to 30 parts by weight, more preferably 15 to 25 parts by weight with respect to 100 parts by weight of the organic solvent.

  Polyester polyol, polyethylene glycol, etc., which are reaction products of phthalic acid and diethylene glycol, are used as plasticizers that are optional additives, and inorganic fillers that are also optional additives include calcium carbonate, magnesium carbonate, calcium sulfate, sulfuric acid Barium, calcium silicate, magnesium hydroxide, aluminum hydroxide, mica, talc, bentonite, zeolite, silica gel, aluminum oxide, titanium oxide, antimony oxide, and the like are used.

The foamable resol type phenolic resin molding material of the present invention is, for example, the above-mentioned liquid resol type phenolic resin, a nitrogen-containing crosslinked cyclic compound dissolved in the above furfuryl alcohol, a foam stabilizer, and further, if necessary, It can be prepared by adding an inorganic filler and a plasticizer, mixing, adding a foaming agent and an acid curing agent to the mixture, and then feeding the composition to a mixer and stirring.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples. Further, some comparative examples not belonging to the present invention are listed.

 (A) Preparation of molding material

  3 parts by weight of a polyester polyol obtained by reacting phthalic acid and diethylene glycol as a plasticizer in a molar ratio of 1: 2 to 100 parts by weight of a liquid resol type phenolic resin (product number: PF-339 manufactured by Asahi Organic Materials Co., Ltd.), a foam stabilizer 3 parts by weight of castor oil EO adduct (added mole number 30) was added and mixed.

  A solution 4 in which 0.8 parts by weight of hexamethylenetetramine (hexamine) as a nitrogen-containing crosslinked cyclic compound additive was previously dissolved in 3.2 parts by weight of furfuryl alcohol with respect to 106 parts by weight of this phenol resin mixture. Parts by weight, 6.8 parts by weight of isopropyl chloride and 1.2 parts by weight of isopentane as a blowing agent, and 13 parts by weight of a mixture of paratoluenesulfonic acid: xylenesulfonic acid mass ratio = 2: 1 as an acid curing agent, The foamable phenol resin molding material was prepared by stirring and mixing.

In Example 1, a phenol resin foam was produced in the same manner as in Example 1 except that the hexamethylenetetramine furfuryl alcohol solution was changed to 6 parts by weight.

Comparative Example 1

  In Example 1, a phenol resin foam was produced in the same manner as in Example 1, except that the hexamethylenetetramine furfuryl alcohol solution was not used.

Comparative Example 2

  In Example 1, a phenol resin foam was produced in the same manner as in Example 1 except that hexamethylenetetramine was not dissolved in furfuryl alcohol and used as a powder.

  That is, 3 parts by weight of a polyester polyol obtained by reacting phthalic acid and diethylene glycol in a molar ratio of 1: 2 as a plasticizer was added to 100 parts by weight of a liquid resol type phenolic resin (product number: PF-339 manufactured by Asahi Organic Materials Co., Ltd.). 3 parts by weight of castor oil EO adduct (addition mole number 30) as a foam stabilizer and 0.8 parts by weight of hexamethylenetetramine as a nitrogen-containing crosslinked cyclic compound additive with respect to 103 parts by weight of this phenol resin mixture 5.6 parts by weight of isopropyl chloride and 1.2 parts by weight of isopentane as a foaming agent, and 15.5 parts by weight of a mixture of paratoluenesulfonic acid: xylenesulfonic acid mass ratio = 2: 1 as an acid curing agent were supplied to a stirrer. The foamable phenol resin molding material was prepared by stirring and mixing.

(B) Production of Foam Foamable phenolic resin molding materials obtained in Examples and Comparative Examples were each discharged into a mold, and after putting it into a 75 ° C. dryer, 300 seconds was defined as the molding end time. Thereafter, the molded product was taken out from the mold and then placed in a dryer at 85 ° C. for 5 hours to produce a phenolic resin foam.

(C) Performance Evaluation Test The obtained phenolic resin foam was evaluated for the following items.

(1) Density The density was measured according to JIS A 9511.

(2) Compressive strength Compressive strength was measured according to JIS A 9511.

The test results are shown in Table 1 together with the component ratio of the molding material.

  As can be seen from Table 1, the phenolic resin foams obtained from the molding materials of the examples are superior in compressive strength compared to those of the comparative examples.

  ADVANTAGE OF THE INVENTION According to this invention, the foamable phenol resin molding material which gives the phenol resin foam excellent in intensity | strength and improved in brittleness, and the phenol resin foam which has the said characteristic can be provided.

Claims (4)

In a foamable resol-type phenolic resin molding material containing a liquid resol-type phenolic resin, a foaming agent, a foam stabilizer, an acid curing agent, and a nitrogen-containing crosslinked cyclic compound additive, the nitrogen-containing crosslinked cyclic compound additive is full. A foamable resol-type phenol resin molding material characterized by being dissolved in furyl alcohol . Nitrogen-containing crosslinked cyclic compound additive 0.1 per 100 parts by weight of liquid resol type phenolic resin
The foamable resol type phenolic resin molding material according to claim 1, comprising 10 to 10 parts by weight. The foamable resol-type phenol resin molding material according to claim 1 or 2 , wherein the nitrogen-containing crosslinked cyclic compound is at least one selected from quinuclidine, pyridine and hexamethylenetetramine. A phenol resin foam obtained by foam-curing the foamable resol-type phenol resin molding material according to any one of claims 1 to 3 .