JP2001335655A - Method of producing phenolic resin foamed body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phenolic resin foamed body having high flame-retardancy which has good processability and foamability while being prevented from the occurrence of a bleeding. SOLUTION: This method of producing phenolic resin foamed body comprises the steps of adding 40 to 200 pts.wt. of a surface treated metal hydrate to 100 pts.wt. of phenolc resin, and further adding acidic curing agent to foam and cure, wherein the surface treatment is made by at least one compound selected from the group consisting of fatty acid, fatty acid ester, fatty acid amide, fatty acid metal salt, higher alcohol, titanate coupling agent, silane coupling agent, and aluminum coupling agent contained in a formulated liquid comprising at least resol type phenolic resin and a foaming agent.

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 phenol resin foam used for building materials and industrial materials.
More specifically, the present invention relates to a method for producing a phenolic resin foam having good processability and foaming property, no bleeding, and high flame retardancy.

[0002]

2. Description of the Related Art Conventionally, synthetic resins are often used as building materials and industrial materials. In the construction field, it is used as an alternative to natural wood for interior materials such as wall materials, partitioning materials, doors, underfloor insulation, ceiling materials, and sliding doors. Attention has been paid to compensate for defects such as swelling and shrinkage due to moisture release.

[0003] In modern buildings, in particular, with the partial revision of the certification for building materials, the point of non-combustibility has been widely taken up, and various measures have been taken to impart fire resistance to synthetic resin products. For example, many products having flame retardancy by adding a flame retardant, an organic or inorganic filler, or compounding a highly fire-resistant skin material with a synthetic resin are commercially available. However, polyurethane foams, polystyrene foams, and the like, which are generally used as synthetic resins, are not satisfactory in terms of nonflammability of the resin itself, and do not have disaster prevention properties as interior materials.

[0004] Against this background, in recent years, attention has been paid to the flame retardancy of phenolic resin foams, and the interior of the phenolic resin foams has excellent heat resistance and soundproofing properties, as well as good chemical resistance and weather resistance. It is expected as a material. The flame retardancy is JIS based on phenolic resin foam alone or simple composite
It is possible to obtain a flame-retardant second-class determination based on A1321.

[0005] Phenolic resins, which are the main components of phenolic resin foams, are roughly classified into resol-type phenolic resins and novolak-type phenolic resins according to the reaction conditions such as the ratio of phenols to formaldehyde and the catalyst. Resins are widely used because of their good heat resistance and good machinability.
The resol-type phenol resin becomes an insoluble and infusible polymer when cured with an acid, and the curing reaction speed is proportional to the hydrogen ion concentration and accelerated by heating.

[0006]

However, when a metal hydrate is added as a flame retardant to further enhance the flame retardancy of the phenol resin foam, the hydroxyl groups in the metal hydrate react with the acid curing agent. In addition, the hydrogen ion concentration of the phenolic resin compounding liquid decreases, and the curing rate decreases. If the curing speed is reduced, the desired hardness cannot be obtained, and unreacted raw materials remain, so that the water-soluble oligomer leaches to the surface, so-called bleeding occurs.

In addition, the phenolic resin itself has a high viscosity, and the addition of an inorganic filler as an inorganic powder further increases the viscosity, so that workability is poor and kneading is difficult.
There is a problem that poor foaming occurs. In addition, foamed gas bubbles and air bubbles mixed in when stirring and mixing,
There is also a problem that the material is difficult to be removed due to high viscosity.

An object of the present invention is to provide a method for producing a phenol resin foam which has good workability and foamability, does not cause bleeding after molding, and has high flame retardancy. I do.

[0009]

That is, according to the invention of claim 1 of the present application, at least a resol type phenol resin,
In a method for producing a phenolic resin foam in which a compounding liquid containing a foaming agent and an acid curing agent is foamed and cured, a metal hydrate having been subjected to a surface treatment is added to the compounding liquid. The surface treatment is a surface treatment for preventing a reaction with an acid curing agent, and the treatment can impart flame retardancy to the phenol resin foam without reacting with the acid curing agent.

According to the invention described in claim 2 of the present application, claim 1
In the method for producing a phenolic resin foam as described above, the surface treatment refers to a fatty acid, a fatty acid ester, a fatty acid amide, a fatty acid metal salt, a higher alcohol, a titanate coupling agent, a silane coupling agent, or an aluminum coupling agent. At least one type of surface treatment.

According to the invention described in claim 3 of the present application, claim 1
Or In the method for producing a phenolic resin foam according to item 2, the metal hydrate is aluminum hydroxide.

According to a fourth aspect of the present invention, in the method for producing a phenolic resin foam obtained by foaming and curing a compounded liquid containing at least a resol type phenolic resin, a foaming agent, an acid curing agent, and aluminum hydroxide, Surface treatment with at least one of fatty acid, fatty acid ester, fatty acid amide, fatty acid metal salt, higher alcohol, titanate coupling agent, silane coupling agent, aluminum coupling agent to prevent reaction with acid curing agent Is added, and 40 to 200 parts by weight or more is added to 100 parts by weight of the phenol resin.

[0013]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, any of the phenolic resin foams that can be used can be used. The resol type phenol resin, which is the main material, is a synthetic resin obtained by a reaction between phenols and formaldehyde. Phenols include phenol, o-cresol, m
-Cresol, p-cresol, p-tert-butylphenol, p-tert-octylphenol, p-
Nonylphenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, resorcinol, bisphenol-A, catechol, hydroquinone and the like can be mentioned.

An acid curing agent is used as the curing agent.
Commonly used acid curing agents include, for example, p-toluenesulfonic acid, phenolsulfonic acid,
Organic acids such as xylene sulfonic acid and benzene sulfonic acid, and inorganic acids such as sulfuric acid, hydrochloric acid and phosphoric acid. These acid curing agents can be used alone or in combination of two or more.

As the foaming agent, fluorocarbons such as fluorotrichloromethane and trifluorotrichloroethane were generally used. However, alternatives have recently been studied from the viewpoint of environmental problems such as destruction of the ozone layer. In the present invention, known ones can be used, but it is preferable to use one in consideration of safety and environmental aspects. Specifically, volatile hydrocarbons such as butane, pentane, hexane, gasoline, and naphtha; ketones such as acetone and methyl ethyl ketone; alcohols such as methyl alcohol and ethyl alcohol; and halogenated hydrocarbons such as methylene chloride. Is mentioned. These may be used alone or in combination of two or more.

[0016] Inorganic fillers can be added. Specifically, clay, calcium carbonate, ammonium borate, potassium borate, zinc powder, zinc phosphate, aluminum phosphate,
Ferrite, magnetite, silicon dioxide, metal hydrate and the like can be mentioned, and these can be used alone or in combination of two or more. Also, melamine, dicyandiamide,
An organic filler such as a gelled powdery synthetic resin may be added.

Among the above inorganic fillers, metal hydrates are preferably used as flame retardants. Examples of the metal hydrate include aluminum hydroxide and magnesium hydroxide. Among them, aluminum hydroxide is not only inexpensive but also hardly burns, and has a temperature of 240 to 550 ° C.
And exhibits an excellent flame-retardant effect such as suppression of resin ignition or continuous inhibition of combustion.

The metal hydrate is preferably subjected to a surface treatment for preventing a reaction with an acid curing agent. The method is not particularly limited. A wet method in which a solvent and a surface treatment agent are added to and mixed with a metal hydrate, and a method in which a solution in which a surface treatment agent is previously mixed with a solvent is added to the metal hydrate. By performing this surface treatment, the reaction with the acid curing agent can be prevented, and the compatibility with the resin can be increased. Incidentally, it is possible to use a metal hydrate that has not been subjected to a surface treatment in combination. Further, the amount of the metal hydrate to be added is preferably phenol resin 100 to make the flame retardancy effective.
40 to 200 parts by weight, more preferably 4 parts by weight,
It is preferable to add 0 to 60 parts by weight.

As the surface treating agent, known agents can be used. Specific examples include fatty acids, fatty acid esters, fatty acid metal salts, fatty acid amides, higher alcohols, titanate-based coupling agents, silane-based coupling agents, and aluminum-based surface treatment agents. Coupling agents and the like can be mentioned. More specifically, fatty acids include higher fatty acids having 10 or more carbon atoms, such as stearic acid, erucic acid, palmitic acid, lauric acid, and heveninic acid, and vinyltrimethoxysilane and 3-methacryloxy as silane coupling agents. Propyltrimethoxysilane, 3-glydoxypropyltrimethoxysilane, 3-aminopropylpropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis- (3-
(Triethoxysilyl) propyl) tetrasulfide,
As the titanate-based coupling agent, isopropyl triisostearoyl titanate, isopropyl tris-titanate, isopropyl trititanate, isopropyl tridecylbenzenesulfonyl titanate, and as the aluminum-based coupling agent, acetoalkoxy aluminum diisopropylate and the like are often used.

Further, as a commonly used flame retardant,
An organic phosphorus compound may be added. Specifically, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trischloroethyl phosphate, trischloropropyl phosphate, trisdichloropropyl phosphate, tris resyl phosphate, trisixylenyl phosphate, cresyl There are diphenyl phosphate, xylenyl diphenyl phosphate and the like.

A fibrous base material may be added. This functions as a dimensional stabilizer, specifically, glass fiber, carbon fiber, aramid fiber, polyimide fiber, novoloid fiber,
Asbestos, ceramic fibers, metal fibers and the like can be used.

A foam stabilizer can be added. In the present invention, known compounds can be used, and specific examples thereof include nonionic surfactants and silicone surfactants.

A formaldehyde scavenger may be added. The effect of removing formaldehyde that cannot be completely removed by the heat treatment of the present invention can be expected. The use is not particularly limited, but examples thereof include physical adsorption with silica, activated carbon, and the like, and chemical adsorption with a hydrazide compound, a dihydrazide compound, an azole compound, an azine compound, and the like.

[0024] The amount of the above-mentioned compound is 10
It is preferable that the foaming agent is 0.5 to 40 parts by weight, the curing agent is 1 to 50 parts by weight, and the foam stabilizer is 0.1 to 10 parts by weight based on 0 parts by weight.

The above-mentioned composition is mixed and stirred by a known method to carry out foam molding. Known techniques such as slab foaming, mold foaming, panel foaming, laminate board foaming, and spray foaming can be used as the foam molding method.
When a mold is used, its shape is not particularly limited, but a shape devised to prevent gas or air accumulation generated during foam molding is preferable. The foam molding conditions are preferably 30 to 80 ° C. for 2 to 60 minutes.

When the core material is used, the core material is not limited to one having straightness in the longitudinal direction, and may have a curve or a single bend. It is preferable that there are no two or more grooves or steps in order to reduce the contraction stress in the longitudinal direction of the foam.
Usually, when forming into a plate shape, steel plate, aluminum plate, gypsum board, asbestos slate plate, calcium silicate plate, wood plate,
Plywood, particle board, MDF board or the like is used. When forming into a cylindrical or prismatic shape, it is possible to use rod-like or prismatic iron materials, reinforced concrete materials, aluminum materials, wood, laminated materials, etc., or steel pipes, aluminum pipes, paper pipes, etc. on round pipes or square pipes. it can.

In order to alleviate the shrinkage stress during foam molding and prevent internal cracks, the surface of the core material may be surrounded by a buffer sheet. As the buffer sheet, a highly expanded polyolefin sheet, a foamed or non-foamed rubber sheet, or the like is used, and its thickness is preferably about 1 to 2 mm.

After the foam molding as described above, it is preferable, but not essential, to perform the following two-stage heat treatment. First, the first-stage heat treatment is preferably a heat treatment at less than 90 ° C. If the temperature exceeds 90 ° C., water vapor is generated, and internal cracks may occur during the first heat treatment. More preferably, it is 40 to 70 ° C, and if it is lower than 40 ° C, curing is insufficient. The processing time is preferably at least 3 hours, more preferably at least 5 hours. In this heat treatment, preliminary curing is performed to a strength that can withstand the expansion of the gas component and the water vapor pressure generated in the second heat treatment.
If this heat treatment is not performed, swelling and warpage occur during the second heat treatment.

Next, a second stage heat treatment is performed. The heat treatment temperature is preferably 90 ° C. or higher. More preferably, 1
It is 00 to 130 ° C., and it is not preferable that the temperature is 150 ° C. or more in consideration of heat resistance. The processing time is preferably at least 3 hours, more preferably at least 5 hours. This high heat treatment completes the curing reaction, completes the shrinkage, and removes free formaldehyde. By this high heat treatment, it is possible to provide a foam which has high strength even after production and which can withstand use even at high heat.

The heat treatment in the first stage and the heat treatment in the second stage may be continuous or discontinuous. Specifically, the term “discontinuous” means that after the first-stage heat treatment, the substrate is left at room temperature, and then the second-stage heat treatment is performed. When the heat treatment is continuous, the transition from the first heat treatment to the second heat treatment may be performed from the first heat treatment to the second heat treatment in a variable temperature heat treatment apparatus. The heat treatment in the second step and the heat treatment in the second step may be performed by different heat treatment apparatuses. Further, the heat treatment is not limited to two stages, but three or more stages of heat treatment are also possible. In the case of a foam molding method using a mold, it is desirable to remove the phenolic resin foam from the mold and perform the heat treatment.

The phenolic resin foam according to the present invention alone can be used to determine the first class of flame retardancy by a surface test of flammability evaluation of building materials according to JIS A 1321 in order to determine the density of the phenolic resin foam after heat treatment. It is preferable to select a compounding agent that imparts flame retardancy and adjust the compounding ratio. Since the density of the phenolic resin foam is affected by the amount of the compound added, the mixing ratio, the foaming amount, the temperature, the shape of the mold, and the like, the density is appropriately adjusted according to needs and circumstances.

The phenolic resin foam according to the present invention can be coated with a decorative sheet or the like or provided with a surface finishing layer by painting or the like, depending on the purpose of use, to provide flame retardancy and design. It is. Further, the formaldehyde scavenger may be added to a paint or the like.

[0033]

Next, the present invention will be described in more detail with reference to specific examples. Examples 1 and 2, Comparative Examples 1 to 3 100 parts by weight of a liquid resole type phenol resin solution (manufactured by Dainippon Ink and Chemicals, Inc.) and 1 part by weight of silicone-modified oil as a foam stabilizer (manufactured by Dow Corning Toray Silicone Co., Ltd.) : SH-193), 1.5 parts by weight of pentane and 1.5 parts by weight of hexane as foaming agents were added and mixed, and then a predetermined amount of aluminum hydroxide (manufactured by Showa Denko KK) shown in Table 1 and a dimensional stabilizer Was added and stirred and mixed with 20 parts by weight of glass fiber (Mild Fiber manufactured by Central Glass Co., Ltd.) to prepare a phenolic resin-mixed liquid.

A silicone rubber mold prepared by drawing a drawn log of a natural cedar with a tip diameter of 120 mm and a length of 3 m in a resin mold reinforced with a two-part iron frame is cut open in the longitudinal direction. Set the diameter 90 as the core material in the center
A laminated wood having a length of 3.1 m and a length of 3.1 mm was installed and the mold was closed.

After the mold was heated to 55 ° C., the upper casting port was opened at an inclination of 45 ° C., and 15 parts by weight of a 63% aqueous solution of phenolsulfonic acid (Daiichi Kogyo Co., Ltd.) (Resinol PS-63, manufactured by Pharmaceutical Co., Ltd.) was added thereto, and the mixed solution that was vigorously stirred was immediately poured, and allowed to stand for 20 minutes to perform foaming and curing.

Thereafter, the molded body was released from the mold, heat-treated at 60 ° C. for 5 hours in an oven, and further heated at 100 ° C. for 5 hours.
Heat treatment was carried out for a period of time, followed by sufficient cooling at room temperature, and the occurrence of bleed was visually observed. Further, a surface test for evaluating the flammability of building materials was performed according to JISA 1321.
The results are also shown in Table 1.

[0037]

[Table 1]

As a result, no bleeding occurred in the examples to which the surface-treated aluminum hydroxide was added, and the foamability and workability were good. On the other hand, in the comparative example in which aluminum hydroxide without surface treatment was added, workability was poor due to high viscosity, and foaming defects were partially observed,
Bleeding occurred after molding. In Example 2 in which 50 parts by weight of the surface-treated aluminum hydroxide was added,
It was possible to judge the flame retardant class 1.

[0039]

As described above, by adding the surface-treated aluminum hydroxide, the compatibility with the resin is good, the workability and the foaming property are good, and no bleeding occurs, and By setting the addition amount to 40 to 200 parts by weight, it is possible to provide a method for producing a phenolic resin foam with further improved flame retardancy.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 61/06 C08L 61/06 F term (Reference) 4F074 AA60 AC20 AF03 AG01 AG10 BA35 BA37 BA39 BA40 BA42 BA45 BA73 BA74 BB01 BB06 BB10 CA21 CC04Z DA15 DA32 DA50 4J002 CC031 DD017 DE148 DG037 DH027 EA016 EB006 EC016 EE026 EV237 FB088 FD138 FD147 FD326 GL00

Claims (4)

[Claims] At least a resol type phenol resin,
In a method for producing a phenolic resin foam obtained by foaming and curing a compounding liquid containing a foaming agent and an acid curing agent, a metal hydrate having been subjected to a surface treatment is added to the compounding liquid, and the surface treatment means an acid. A method for producing a phenolic resin foam, which is a surface treatment for preventing a reaction with a curing agent. 2. The surface treatment includes a fatty acid, a fatty acid ester,
The method for producing a phenolic resin foam according to claim 1, wherein the surface treatment is at least one of fatty acid amide, fatty acid metal salt, higher alcohol, titanate coupling agent, silane coupling agent, and aluminum coupling agent. 3. The method for producing a phenolic resin foam according to claim 1, wherein the metal hydrate is aluminum hydroxide. 4. At least a resol type phenol resin,
In a method for producing a phenolic resin foam obtained by foaming and curing a compounding solution containing a foaming agent, an acid curing agent, and aluminum hydroxide, aluminum hydroxide is used to prevent a reaction with an acid curing agent. Surface treatment with at least one of fatty acid amide, fatty acid metal salt, higher alcohol, titanate-based coupling agent, silane-based coupling agent, and aluminum-based coupling agent has been performed, and the amount added is 100 parts by weight of phenol resin. A method for producing a phenolic resin foam, wherein the amount is 40 to 200 parts by weight.