JPH0853563A - Method for producing phenolic resin foam - Google Patents

Abstract

(57) [Summary] [Purpose] A phenolic resin foam, which is free of voids and faults and has excellent surface smoothness, which enables the use of a foaming agent other than the specified CFCs, which has been difficult in the past, is preferably a non-CFC type. Provided is a method of making a phenolic resin foam. In a method for producing a phenol resin foam by foaming and curing a liquid phenol resin in the presence of an acidic curing agent, a foaming agent and a foam stabilizer, it has two or more hydroxyl groups and / or amino groups in one molecule. A polyether polyol having a molecular weight of 2,500 to 20,000 and an ethylene oxide addition amount of 15% by weight or more, which is obtained by addition-polymerizing an alkylene oxide containing ethylene oxide as an essential component, is used in combination with an organic compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a phenolic resin foam, and more specifically, it has no voids or faults and is excellent in surface smoothness, and is used as a heat insulating material for construction / heat insulation, sound insulation / vibration insulation, etc. The present invention relates to a method for producing a phenol resin foam that can be used for various purposes.

[0002]

2. Description of the Related Art As a typical method for producing a phenol resin foam, a liquid phenol resin has been used as an acidic curing agent,
A method of foam-curing in the presence of a foaming agent and a foam stabilizer is known. However, the use of specific CFC-based blowing agents such as trichlorotrifluoroethane and trichloromonofluoromethane, which have been commonly used in the production of such foams, are strictly regulated worldwide from the viewpoint of global environmental protection, and will be completely abolished in the future. It is supposed to be done. Therefore, in the technical field, alternative fluorocarbons developed as a blowing agent to replace the specific fluorocarbons, such as dichlorofluoroethane (HCFC-141b), dichlorotrifluoroethane (HCFC-123) and conventionally known physical or chemical agents. Attempts have been made to use blowing agents such as methylene chloride, pentane, air, nitrogen and carbon dioxide.

[0003]

However, since this type of foaming agent has a larger gas desorption amount during foam molding than that of the specific flon, the foam obtained generally tends to contain voids and faults. In addition, there is a problem that the surface smoothness is poor and the practicality is lacking. Under such circumstances, the advent of a technology for producing a foam that does not use a specific CFC, particularly a non-CFC type foam, is desired in the technical field.

Therefore, an object of the present invention is to provide a method capable of producing a phenol resin foam which is free of voids and faults and has excellent surface smoothness when using a foaming agent other than specific CFCs. It is in. Another object of the present invention is to provide a method for producing a non-CFC type phenolic resin foam having the above characteristics.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a specific polyether polyol acts extremely effectively in suppressing gas desorption during foam molding, Moreover, they have found that the obtained foam does not contain voids or faults, has excellent surface smoothness, and can be made CFC free, and has completed the present invention.

That is, the present invention relates to a method for producing a phenol resin foam by foaming and curing a liquid phenol resin in the presence of an acidic curing agent, a foaming agent and a foam stabilizer, to produce a phenol resin foam. The molecular weight obtained by addition-polymerizing an alkylene oxide containing ethylene oxide as an essential component to an organic compound having two or more groups is 2,500.
The method for producing a phenol resin foam is characterized in that a polyether polyol having an ethylene oxide addition amount of 15% by weight or more is used in combination.

The liquid phenol resin used in the present invention is a resin which is liquid at room temperature and has a crosslinkable functional group such as a methylol group or a dimethylene ether group which causes a curing reaction in the presence of an acidic curing agent in the molecule. Specific examples thereof include a resol-type phenol resin and a benzyl ether-type phenol resin, and a novolac resol-type phenol resin obtained by adding a methylol group to a novolac-type phenol resin. These liquid phenol resins may be used alone or in combination of two or more, and in some cases, for example, they are used by reacting with or mixing with an epoxy compound, a melamine compound, a guanamine compound and a novolac phenol resin. Good.

A typical resol type or benzyl ether type phenolic resin of the above liquid phenolic resin is phenols and aldehydes, for example, 0.8 mol or more, preferably 1 mol of aldehydes per mol of phenols.
It can be prepared by carrying out an addition condensation reaction in the presence of a catalyst at a ratio of ˜4.0 mol, preferably further neutralizing and concentrating under reduced pressure. Examples of the phenols include, in addition to phenol, alkylphenols such as cresol, xylenol, nonylphenol, and para-tert-butylphenol, polyhydric phenols such as resorcinol, catechol, and pyrogallol, such as bisphenol F such as bisphenol F and bisphenol A, such as resorcinol. Residue, catechol residue,
Phenol-based purification residues such as bisphenol A residue are used alone or in combination of two or more. As the aldehydes, for example, formaldehyde-supplying substances such as formalin, paraformaldehyde, acetal and the like, as well as formaldehyde-affecting substances such as glyoxal and furfural, and the like are used alone or in combination of two or more. Examples of the catalyst include potassium hydroxide, sodium hydroxide, lithium hydroxide, barium hydroxide, calcium hydroxide, magnesium oxide, sodium phosphate, potassium carbonate, sodium hydrogen carbonate, ammonia, hexamethylenetetramine, triethylamine, triethanolamine. Basic catalysts such as zinc acetate, zinc borate,
Acidic divalent metal salt catalysts such as zinc chloride and lead naphthenate are used, but in some cases, they may be used in combination.

The acidic curing agent used in the present invention is
An acidic compound that accelerates the curing reaction of the liquid phenol resin, and specifically, a monocyclic aromatic sulfone such as phenolsulfonic acid, benzenesulfonic acid, ethylbenzenesulfonic acid, paratoluenesulfonic acid, xylenesulfonic acid, and styrenesulfonic acid. Acids, polycyclic aromatic sulfonic acids such as naphthalene sulfonic acid, naphthol sulfonic acid, anthracene sulfonic acid, anthranol sulfonic acid, alkyl sulfonic acids such as methane sulfonic acid, sulfonated creosote oil, monocyclic aromatic sulfonic acid Examples include condensates of formaldehyde, polycyclic aromatic sulfonic acids and / or condensates of sulfonated creosote oil and formaldehyde, sulfonated phenolic resins and inorganic acids such as sulfuric acid and phosphoric acid. It is not limited to the example. These acidic curing agents may be used alone or in combination of two or more, and the compounding amount thereof is usually selected in the range of 2 to 40 parts by weight with respect to 100 parts by weight of the liquid phenol resin.

The foaming agent used in the present invention is a substance which mixes with or dissolves in the liquid phenol resin to foam it, preferably a substance excluding specific chlorofluorocarbon, and specifically, for example, dichloromonofluoromethane ( HCFC
-21), dichlorofluoroethane (HCFC-141
b), dichlorotrifluoroethane (HCFC-12
3), dichloropentafluoropropane (HCFC-2
25ca, HCFC-225cb) and other alternative freons, as well as halogenated aliphatic hydrocarbons such as perfluorohexane, perfluoropentane, methylene chloride, propyl chloride, dichloroethane, trichloroethane, tetrachloromethane, etc., such as butane, pentane, hexane And the like, physical hydrocarbons such as aliphatic hydrocarbons such as diethyl ether and diisopropyl ether, and gaseous bodies such as air, nitrogen and carbon dioxide, such as sodium hydrogen carbonate, sodium carbonate, barium carbonate and calcium carbonate. , Hydrogen peroxide, polyisocyanate, water, chemical blowing agents such as p-toluenesulfonyl hydrazide, oxybisbenzenesulfonyl hydrazide, azodicarbonamide and azobisisobutyronitrile, and the like. It is not limited to the examples. These foaming agents may be used alone or in combination of two or more kinds, and the blending amount thereof is the liquid phenol resin 10
It is usually selected in the range of 0.5 to 30 parts by weight with respect to 0 parts by weight.

The foam stabilizer used in the present invention is a nonionic or anionic type having a function depending on the purpose of use such as miniaturization, homogenization and stabilization or communication of cells formed during foam molding. And a cationic surfactant,
Among them, nonionic or anionic surfactants, especially nonionic surfactants are generally used. Examples of such nonionic surfactants include polysiloxane oxyalkylene copolymers, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene lanolin fatty acid esters, castor oil ethylene oxide adducts, and polyoxyethylene lauryl alcohol. be able to. Examples of anionic surfactants include sodium dodecylbenzene sulfonate, sodium dodecane sulfonate, sodium dioctyl sulfosuccinate, and diethylamino oleate. These foam stabilizers may be used alone or in combination of two or more, and the compounding amount thereof is usually selected in the range of 0.3 to 10 parts by weight with respect to 100 parts by weight of the liquid phenol resin.

The polyether polyol used in the present invention has two hydroxyl groups and / or amino groups in one molecule.
After addition-polymerizing an organic compound having one or more (hereinafter, simply referred to as an organic compound) and an alkylene oxide containing ethylene oxide as an essential component in the presence of a catalyst at, for example, 80 to 150 ° C. and 0.5 to ² kg / cm ^2. The molecular weight is 2,500 to 2, which is produced by neutralizing and dehydrating as necessary.
0000, more preferably 4000 to 10000, and the amount of ethylene oxide added is adjusted to 15% by weight or more, more preferably 30% by weight or more. If the molecular weight is less than 2,500, the gas desorption suppressing effect is small, and if it exceeds 20,000, it becomes difficult to homogeneously mix with the liquid phenol resin. Further, if the amount of ethylene oxide added is less than 15% by weight, there is a disadvantage that a cell membrane breakage phenomenon occurs during foam molding. Typical commercially available products of such polyether polyols include Pionein P-4330-T (see Example 1), which is a trade name of Takemoto Yushi Co., Ltd., and Pieonin P-5050-T (trimethylolpropane as an organic compound). The obtained molecular weight is 5000 and the amount of ethylene oxide added is 50% by weight.
), And Pionine P-5070-T (having a molecular weight of 5000 obtained by using trimethylolpropane as an organic compound and an ethylene oxide addition amount of 70% by weight).

The molecular weight of the polyether polyol and the amount of ethylene oxide added here can be determined by the following method. The molecular weight is, for example, ethylene oxide (EO) using a polyfunctional organic compound having two or more hydroxyl groups (calculated as 1 functional group) and / or amino groups (calculated as 2 functional groups) in one molecule as an initiator. Hydroxyl value of polyether polyol obtained by addition polymerization of propylene oxide (PO) (JIS-K-
1557) is measured and calculated by the following calculation formula.

[0014]

[Equation 1]

The amount of ethylene oxide added (percentage by weight) is ¹ H-NMR (solvent: deuterated chloroform,
(Concentration: 5% by weight) of the NMR chart obtained at the concentration of 5% by weight) and the integrated value (a) of the peak near 3.7 ppm and the integrated value (b) of the peak near 1.1 ppm are calculated by the following formula.

[0016]

[Equation 2]

The above organic compounds include ethylene glycol, propylene glycol, diethylene glycol,
Examples include dipropylene glycol, bisphenol A, bisphenol F, glycerin, trimethylolpropane, hexanetriol, triethanolamine, pentaerythritol, ethylenediamine, methylglucoside, diethylenetriamine, sorbitol, sucrose, and the like. Among them, glycerin, trimethylolpropane And mixtures thereof are preferably used. Examples of alkylene oxides other than ethylene oxide include propylene oxide, butylene oxide, styrene oxide, etc. Among them, propylene oxide is generally used. Further, as the catalyst, for example, potassium hydroxide, sodium hydroxide and the like are preferably used.

The above polyether polyols may be used in combination of two or more, if necessary, and the compounding amount thereof is within the range of 0.3 to 10 parts by weight with respect to 100 parts by weight of the liquid phenol resin. It is preferable to select.
If the amount is less than 0.3 parts by weight, the effect of suppressing gas desorption is small, and if it exceeds 10 parts by weight, the foam tends to shrink easily.

In the present invention, the phenol resin foam is a liquid phenol resin as described above, an acidic curing agent,
A foaming agent, a foam stabilizer, a polyether polyol, and other additives that are added as needed are uniformly mixed by a foaming method generally adopted in the art, for example, a high-speed stirring mixing method, a high-pressure collision mixing method, or the like. After the foaming stock solution is prepared in this manner, it can be produced by subjecting it to foaming and curing by a continuous foaming method, an injection foaming method, an in-situ foaming method or the like.

The above-mentioned other additives include γ-
Aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane and other silane coupling agents, resorcinol, alkylresorcinol and other curing accelerators, urea, melamine and other formaldehyde scavengers,
Urea resin, melamine-based resin, phosphorus-containing compound, halogen-containing compound, flame retardant such as aluminum hydroxide, shirasu balloon, glass balloon, porous aggregate, inorganic or organic filler such as wood powder, ceramic fiber Fiber reinforcements such as glass fiber, carbon fiber, phenol fiber, aramid fiber,
Other examples include plasticizers, neutralizing agents, coloring agents and the like.

[0021]

EXAMPLES Next, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The gas desorption amount during foam molding, the reactivity of the foaming stock solution, and the foam characteristics were measured by the following test methods.

(1) The amount of desorbed gas is 100 g of liquid resol type phenol resin, 2 g of a foam stabilizer (castor oil ethylene oxide adduct, trade name Pionine D225, manufactured by Takemoto Yushi Co., Ltd.) and a predetermined polyether. 3 g of polyol
Was dissolved, a predetermined foaming agent was added and thoroughly mixed, and the liquid temperature was further adjusted to 20 ° C., and then a predetermined amount of an acidic curing agent adjusted to 20 ° C. was added thereto to obtain a homogenized product manufactured by Tokushu Kika Kogyo The foaming undiluted solution prepared by mixing with Disper (trademark) (rotation speed: 8000 rpm) for 15 seconds was injected into a side free mold (thickness 50 mm) on an electronic balance installed in an atmosphere of 70 ° C. The weight loss during the entire period was measured every time, and this was calculated by converting it per 100 g of the foaming stock solution. (2) Cream time (CT), which indicates the reactivity of the effervescent stock solution
The gel time (GT) was measured by a conventional method using about 100 g of the foaming stock solution at 25 ° C. collected in a 500 cc paper cup. (3) The density and compressive strength of the foam are JIS-A-951.
It measured according to 4. (4) The presence or absence of voids and faults in the foam and the surface smoothness were visually determined. (5) The cell diameter of the foam was measured using a microscope [VMS-300 (trademark) manufactured by Meisho Machine Co., Ltd.].

(Reference Example) 300 kg of phenol, 306 kg of 47% by weight formalin and 30 kg of 20% by weight sodium hydroxide aqueous solution were charged into a reaction kettle equipped with a thermometer, a stirrer and a reflux condenser, and then stirred and mixed at about 90 ° C. And reacted for 2 hours. Then, cool to 40 ° C, neutralize to pH 7 with phenolsulfonic acid, and stir and mix for about 60 minutes.
A liquid resol-type phenol resin was prepared by heating and concentrating under a vacuum of mmHg. The obtained liquid resol-type phenol resin had a viscosity of 75 poise / 25 ° C. (B-type viscometer) and a number average molecular weight of 254 (gel perchromatography method).

Example 1 Obtained by addition-polymerizing ethylene oxide and propylene oxide to 100 kg of the liquid resol-type phenol resin obtained in the above Reference Example as a foam stabilizer, 2 kg of Pionine D225 and trimethylolpropane (organic compound). Polyether polyol having a molecular weight of 4300 and an ethylene oxide addition amount of 30% by weight (trade name: Pionine P-4330-T, Takemoto Yushi Co., Ltd.)
Made by mixing and dissolving 3 kg and adjusting the temperature to 20 ° C.
A liquid, methylene chloride adjusted to 20 ° C. as a foaming agent, and a 63 wt% phenolsulfonic acid aqueous solution adjusted to 20 ° C. as an acidic curing agent were prepared as a liquid III.

Next, on the lower surface material (calcium silicate / glass fiber mixed inorganic paper) conveyed by the endless conveyor, the above-mentioned I liquid / II liquid / III liquid =
The foaming stock solution prepared by mixing at a weight ratio of 105/7/15 was supplied, and the upper surface material (calcium silicate / glass fiber mixed inorganic paper) was superposed facing each other, and then this was guided to a double conveyor with a heating mechanism. Form a foam with face materials on both sides by foaming and curing at 70 ° C and adjusting the thickness, and cut this to a specified size to phenol resin foam panel (non-CFC type, length 1800 mm x width 910 mm).
X thickness 50 mm) was produced. The obtained panel had good surface smoothness without dents, and voids and faults were not observed even in the foam portion. Also, the amount of gas desorbed during foam molding, the reactivity of the foaming stock solution, the density of the foam,
The compressive strength, the cell diameter, etc. were measured by the above test method. The results are shown in Table 1.

Example 2 A non-fluorocarbon type was prepared in the same manner as in Example 1 except that 5% by weight of barium carbonate was added as a foaming agent to the liquid resol type phenol resin to prepare a foaming stock solution. The phenol resin foam panel of was produced. The obtained panel had good surface smoothness without dents, and voids and faults were not observed even in the foam portion. Also, the amount of gas desorbed during foam molding, the reactivity of the foaming stock solution, the density of the foam,
The compressive strength, the cell diameter, etc. were measured by the above test method. The results are shown in Table 1.

(Examples 3 to 6) A non-CFC type phenol was prepared in the same manner as in Example 1 except that the foaming stock solution was prepared by changing the polyether polyol and the acidic curing agent as shown in Table 1. A resin foam panel was produced. Each of the obtained panels had good surface smoothness without dents, and voids and faults were not observed even in the foam portion. Further, the amount of gas desorbed during foam molding, the reactivity of the foaming stock solution, the density of the foam, the compressive strength, the cell diameter, etc. were measured by the above-mentioned test methods. The results are shown in Tables 1 and 2.

(Examples 7 to 8) A non-CFC type or alternative CFC was prepared in the same manner as in Example 1 except that the foaming agent and the acidic curing agent were changed as shown in Table 1 to prepare a foaming stock solution. A type of phenolic resin foam panel was made. Each of the obtained panels had good surface smoothness without dents, and voids and faults were not observed even in the foam portion. Further, the amount of gas desorbed during foam molding, the reactivity of the foaming stock solution, the density of the foam, the compressive strength, the cell diameter, etc. were measured by the above-mentioned test methods. Table 3 shows the results.

Comparative Example 1 A non-CFC type phenol resin foam panel was produced in the same manner as in Example 1 except that the polyether polyol was omitted to prepare the foaming stock solution. The obtained panel had dents with a diameter of about 10 cm at several points on the surface, and innumerable voids and faults were observed in the foam portion. Further, the amount of gas desorbed during foam molding, the reactivity of the foaming stock solution, the density of the foam, the compressive strength, the cell diameter, etc. were measured by the above-mentioned test methods. The results are shown in Table 4.

Comparative Example 2 An alternative CFC type phenol resin foam panel was prepared in the same manner as in Example 1 except that the foaming stock solution was prepared by omitting the polyether polyol. The obtained panel had dents with a diameter of about 6 cm at several points on the surface, and voids and faults were observed in the foam portion. Further, the amount of gas desorbed during foam molding, the reactivity of the foaming stock solution, the density of the foam, the compressive strength, the cell diameter, etc. were measured by the above-mentioned test methods. The results are shown in Table 4.

(Comparative Example 3) A non-CFC type phenol resin foam panel was prepared in the same manner as in Example 1 except that the foaming stock solution was prepared by changing the polyether polyol as shown in Table 4. did. The obtained panel has dents with a diameter of about 8 cm in several places on the surface,
Moreover, numerous voids and faults were observed in the foam part. Further, the amount of gas desorbed during foam molding, the reactivity of the foaming stock solution, the density of the foam, the compressive strength, the cell diameter, etc. were measured by the above-mentioned test methods. The results are shown in Table 4.

(Comparative Example 4) A non-fluorocarbon type was prepared in the same manner as in Example 1 except that the polyether polyol, the foaming agent and the acidic curing agent were changed as shown in Table 5 to prepare a foaming stock solution. A phenolic resin foam panel was made. The resulting panel has a diameter of 8 at several points on the surface.
There were dents of about cm, and numerous voids and faults were observed in the foam part. Further, the amount of gas desorbed during foam molding, the reactivity of the foaming stock solution, the density of the foam, the compressive strength, the cell diameter, etc. were measured by the above-mentioned test methods. The results are shown in Table 5.

Comparative Example 5 The same procedure as in Example 1 was carried out except that the polyether polyol was changed as shown in Table 5 to prepare a foaming stock solution. I couldn't get it.

(Comparative Example 6) The same procedure as in Example 1 was carried out except that the foaming stock solution was prepared in the same manner as in Example 1 except that the foam stabilizer was omitted.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

[0039]

[Table 5]

In the above Tables 1 to 5, PS in the column of acidic curing agent is 63% by weight phenolsulfonic acid, and P
TS is 70 wt% paratoluene sulfonic acid, NS
A is 65% by weight naphthalene sulfonic acid.

As is clear from Tables 1 to 5, by using a specific polyether polyol, it is possible to reduce the amount of desorbed gas at the time of molding a foam, and as a result, except for the specific CFC which has been difficult in the past. It has been confirmed that it is possible to produce a non-CFC type or CFC-type phenol resin foam panel which has no voids or faults and is excellent in surface smoothness, as well as enabling the use of the foaming agent. Further, no adverse effect on the density, compressive strength and cell diameter of the foamed product was observed by using the specific polyether polyol.

[0042]

As described above, according to the production method of the present invention, the use of a specific polyether polyol makes it possible to use a foaming agent other than a specific CFC, which has been difficult in the past, and also to prevent voids and It is possible to provide a phenol resin foam having no fault and excellent in surface smoothness. Further, it is possible to provide a non-CFC type or CFC-type phenol resin foam in order to meet the demand of society concerned about the deterioration of the natural environment due to ozone layer depletion.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isao Kai, No. 26 Shintsu, Minamiyama, Fuso-cho, Niwa-gun, Aichi Prefecture 4 At Asahi Organic Materials Co., Ltd. Aichi factory (72) Takeo Ino Tomihisa, Koriyama-shi, Fukushima Prefecture Yamamachi Fukuhara Jinba 171-2 (72) Inventor St. Takahashi 14-10 Shionogusa, Tomita-cho, Koriyama-shi, Fukushima Prefecture (72) Inventor Kotoshi Sato 832-1 Takatsu, Yachiyo-shi, Chiba 83-2-2 (72) ) Inventor Osamu Yamamoto 3-13-5 Oi, Shinagawa-ku, Tokyo

Claims (1)

[Claims] 1. A method for producing a phenol resin foam by foaming and curing a liquid phenol resin in the presence of an acidic curing agent, a foaming agent and a foam stabilizer, wherein two hydroxyl groups and / or amino groups are contained in one molecule. A molecular weight obtained by addition-polymerizing an alkylene oxide containing ethylene oxide as an essential component to the organic compound having the above is 2,500 to 20,000.
And a polyether polyol having an ethylene oxide addition amount of 15% by weight or more is used in combination, and a method for producing a phenol resin foam.