JP3062731B2 - Method for producing epoxy resin foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing an epoxy resin foam, and more particularly, to a highly rigid and dense epoxy resin foam having flame retardancy at room temperature. The present invention relates to a method for producing an epoxy resin foam which can be obtained by foaming and curing.

[0002]

2. Description of the Related Art Conventionally, various resin foams have been used as heat insulating materials or lightweight members. Among them, polyurethane resin foams, phenol resin foams, and urea resin foams are widely used as thermosetting foams. However, in order to improve the heat resistance and mechanical properties of these resin foams, those obtained by adding an epoxy resin to these resin foams are known.

For example, Japanese Patent Application Laid-Open No. 55-82133 discloses a foaming material comprising a resol type phenol resin, an epoxy resin, a foaming agent, a catalyst, a reinforcing material and a filler. JP-A-120462 and JP-A-58-120644 mainly include a liquid resol type phenol resin, an epoxy resin, an acid catalyst and a foaming agent, and the amount of the epoxy resin added is 100 g of the resol type phenol resin. A foam having a content of 0.06 to 0.3 mol is disclosed.

On the other hand, in order to take advantage of the properties of an epoxy resin such as excellent adhesiveness to other materials, heat resistance, chemical resistance, dimensional stability, and mechanical strength, foaming using an epoxy resin as a base is required. The body has been proposed.

For example, Japanese Patent Application Laid-Open No. 50-76175 discloses an epoxy resin, a specific tetraglycidyl ester,
A method for producing an epoxy resin foam in which a resin mixture containing a swelling agent and a surfactant is cured with a Lewis acid such as boron fluoride is disclosed.

[0006] Also, JP-A-1-197553 discloses that
It is described that a foam can be obtained at room temperature by using a composition containing an epoxy resin, an amine-based curing agent, a curing accelerator, and an inorganic filler.

Further, JP-A-1-103633 and JP-A-4-16337 disclose a polyepoxy compound having two or more epoxy groups in a molecule and a carbonate oligomer having a phenolic hydroxyl group at a terminal. A method for producing an epoxy resin foam in which a reaction catalyst and a reaction catalyst are heated and foamed at 120 to 240 ° C. is disclosed.

Further, Japanese Patent Application Laid-Open No. 5-194780 discloses that
An epoxy resin, a methacrylic resin having an average particle diameter of 300 μm or less, a polyethylene resin, a latent curing agent for an epoxy resin, a decomposable foaming agent and a surfactant,
A foamable resin composition capable of being thermally foamed is disclosed.

Japanese Patent Application Laid-Open No. 5-186625 discloses a heat-foamable resin sheet comprising a liquid or semi-solid epoxy resin and an amine carbonate.

[0010] As described above, various resin foams are widely used as heat insulating materials and lightweight members. Among them, they are used as building materials typified by heat insulating materials and core materials of sandwich panels. In such a case, the building material is desired to have flame retardancy and self-extinguishing properties. Therefore, it is preferable that various resin foams for these applications be flame-retardant or have self-extinguishing properties.

[0011]

However, although phenolic resin foams are flame-retardant, they have high friability,
Lack of adhesion to other materials such as steel plate and wood plate may cause peeling after construction.

The resol-type phenol resin uses an organic acid such as p-toluenesulfonic acid as a curing catalyst. However, since this organic acid remains in the foam, it causes corrosion of the contacting metal and discoloration of the wood. And therefore,
As shown in the prior art (for example, see Japanese Patent Application Laid-Open No. 58-120644), the remaining organic acid is reacted with an epoxy resin and collected to modify the foam to remain. It is necessary to prevent the influence of the organic acid on other materials.

[0013] On the other hand, epoxy resins are superior to phenol resins in adhesion to other materials, mechanical strength, and dimensional stability, but are inferior in flame retardancy and low smoke emission. Even when the foam is modified with an epoxy resin, it is necessary to limit the amount of the epoxy resin added or to add a flame retardant or an inorganic filler in order to maintain flame retardancy.

Similarly, it is necessary to add a flame retardant or an inorganic filler to a foam based on an epoxy resin in order to increase the flame retardancy. However, unlike the case where a flame retardant or an inorganic filler is added to a molded article such as fiber reinforced plastic (FRP), in the case of a resin foam, the quality and particle size of the flame retardant or the inorganic filler to be added are also different. Although different, when added in a large amount, the flowability of the resin during foaming is reduced and the moldability into a predetermined shape is deteriorated, or the size and distribution of the foam after foaming become uneven and the foam Since the mechanical strength is reduced and the thermal conductivity is increased and the heat insulating property is reduced, the amount of addition is limited, and as a result, there is a problem that the flame retardancy becomes insufficient.

In the prior art disclosed in Japanese Patent Application Laid-Open No. 50-76175, since the amount of the Lewis acid as a curing catalyst is smaller than that of the epoxy resin, it takes a long time for foaming and curing. There is also a problem that productivity is low because heating is required for foaming and curing.

Therefore, as a method for improving the flame retardancy and self-extinguishing property of the foam, it is more preferable to incorporate a component contributing to the flame retardancy and self-extinguishing property into the molecular skeleton of the resin constituting the foam. It is thought that.

The present invention solves the above-mentioned disadvantages of the prior art, and is an epoxy having high rigidity, fineness, good adhesion to other materials, and heat resistance and flame retardancy. An object of the present invention is to provide a method for producing an epoxy resin foam which can be obtained by foaming and curing at room temperature without heating the resin foam.

[0018]

Means for Solving the Problems In order to achieve the above object, the construction of the method for producing an epoxy resin foam employed by the present invention comprises the following components A to E or FI to I It is characterized in that a mixture containing the components in a quantitative ratio is foamed and hardened. A: Epoxy resin having two or more epoxy groups in a molecule: 100 parts by weight B: Aldehyde-based condensable resin: 5 to 300 parts by weight C: From phosphoric acid, polyphosphoric acid and phenylphosphonic acid At least one phosphoric acid selected ... 5 to 50 parts by weight or C ': at least one phosphoric acid selected from phosphoric acid, polyphosphoric acid and phenylphosphonic acid, and bonded to a phosphorus atom A mixture of at least one phosphoric acid compound selected from a phosphate having a hydroxyl group and a phosphate ester: 5 to 50 parts by weight D: foaming agent: 1 to 50 parts by weight E: foam stabilizer 0.01 to 10 parts by weight, or F: obtained by reacting an epoxy resin having two or more epoxy groups in a molecule with an aldehyde-based condensable resin,
A liquid reaction product having an epoxy equivalent of 2000 g / eq or less: 100 parts by weight G: at least one phosphoric acid selected from phosphoric acid, polyphosphoric acid and phenylphosphonic acid: 5 to 50 parts by weight, Or G ′: at least one kind of phosphoric acid selected from phosphoric acid, polyphosphoric acid and phenylphosphonic acid, and at least one kind of phosphate and phosphate ester having a hydroxyl group bonded to a phosphorus atom Mixture of phosphoric acid compound: 5 to 50 parts by weight H: foaming agent: 1 to 50 parts by weight I: foam stabilizer: 0.01 to 10 parts by weight

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to specific examples.

The epoxy resin in the present invention is a compound having one or more epoxy groups in a molecule, and is a compound which can be cured by reacting with a curing agent for an epoxy resin. It is a compound also called a main agent or a polyepoxide.

As the epoxy resin, a compound having a glycidyl group as an epoxy group is preferable, and a glycidyl ether-based epoxy resin is particularly preferable. However, the epoxy resin is not limited thereto. For example, a cycloaliphatic epoxy resin, glycidyl ester Epoxy resin, heterocyclic aliphatic epoxy resin, linear aliphatic epoxy resin, etc. (these epoxy resins may be oligomeric)
May be used, and one of these epoxy resins may be selected, or two or more thereof may be used in combination.

The epoxy resin is preferably a liquid at ordinary temperature from the viewpoint of fluidity during foaming. Examples of the epoxy resin include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether,
Glycidyl ether epoxy resins such as resorcin diglycidyl ether, phenol novolak polyglycidyl ether, cresol novolac polyglycidyl ether; glycidyl ester epoxy resins such as hexahydrophthalic acid glycidyl ester and dimer acid glycidyl ester; 3,4-epoxy-6 And cycloaliphatic epoxy resins such as -methylcyclohexylmethylcarboxylate and 3,4-epoxycyclohexylmethylcarboxylate.

The aldehyde-based condensable resin in the present invention is a compound which is crosslinked and cured by condensing a methylol group in the molecule by heating or the like. For example, a resol having one or more methylol groups in the molecule is used. Phenolic resins or amino resins.

The above resole type phenol resin includes:
For example, phenol, cresol, xylenol, 1 mole of phenols such as resorcinol, 1 to 3 moles of a compound obtained by adding formaldehyde can be mentioned,
Also, those obtained by precondensing a resol type phenol resin to increase the number of nuclei can be used without any problem if they are in the B-stage state.

Examples of the amino resin include urea, melamine, benzoguanamine, acetoguanamine,
For 1 mol of glycouril, spiroganamin, etc.,
Compounds obtained by adding 1 to 3 mol of formaldehyde can be used.

However, even in the case of an amino resin, a compound obtained by adding formaldehyde to urea or the like and then etherifying a methylol group, for example, a compound such as hexamethoxymethylated melamine, is used in combination with an epoxy resin described later and phosphoric acid. In some cases, the curing reaction may not easily proceed with the heat of reaction caused by the above reaction, and methanol generated from hexamethoxymethylated melamine or the like during the curing reaction may adversely affect the foaming state of the foam. It is preferable to avoid using amino resins whose groups have been etherified.

The liquid aldehyde-based condensable resin contains an organic solvent or water as a solvent.
When this organic solvent has an adverse effect on the foaming state of the foam, or when water inhibits the curing reaction of the epoxy resin, and further, when obtaining a reaction product of an epoxy resin and an aldehyde-based condensable resin described below. Since water may inhibit such reactions, it is preferable to use a solid or powdered aldehyde-based condensable resin containing no organic solvent or water.

In the first embodiment of the present invention, the aldehyde-based condensable resin is used in an amount of 5 to 100 parts by weight of the epoxy resin without previously reacting with the epoxy resin.
Although it is used in a range of 300 parts by weight, in order to prevent water generated in the course of the condensation curing reaction of the aldehyde-based condensable resin from adversely affecting the foaming state of the foam, 30 to 100 parts by weight is required. It is more preferable to use the above-mentioned aldehyde-based condensable resin within the range.

When the amount of the aldehyde-based condensable resin is 5
If the amount is less than 10 parts by weight, the effect of improving the flame retardancy of the foam by adding the aldehyde-based condensable resin is insufficient. The effect of improving the properties is not so large compared to the added amount, but rather decreases the fluidity of the epoxy resin or the like at the time of foaming, and a foam having a desired size may not be obtained.

On the other hand, in the second embodiment of the present invention, first, an epoxy resin having two or more epoxy groups in a molecule is reacted with an aldehyde-based condensable resin,
Since a liquid reaction product is obtained, the liquid reaction product needs to be capable of further reacting with phosphoric acids described below, and therefore needs to have an epoxy group. The reaction product whose epoxy equivalent is 2000 g / eq or less (hereinafter, referred to as
Simply referred to as an epoxy resin reaction product). In addition, from the viewpoint of the reactivity between the epoxy resin reaction product and phosphoric acids described below, the epoxy equivalent of the epoxy resin reaction product is particularly preferably 500 to 1400 g / eq.

The epoxy resin reaction product is preferably a liquid having a relatively low viscosity at room temperature in order to be mixed with phosphoric acid or the like and foamed as described later. Even if it has a high viscosity, any liquid that has a relatively low viscosity under heating may be used.

The ratio of the aldehyde-based condensable resin to the aldehyde-based condensable resin by reacting the epoxy resin and the aldehyde-based condensable resin is 100 to 100 parts by weight of the epoxy resin. 100 parts by weight, when the ratio of the aldehyde-based condensable resin to 100 parts by weight of the epoxy resin is less than 1 part by weight,
When the flame retardancy of the obtained foam tends to be inferior, and when the proportion of the aldehyde-based condensable resin exceeds 100 parts by weight, the amount of epoxy groups in the produced epoxy resin reaction product decreases, and There is a possibility that the epoxy group for reacting with an acid or the like decreases, and the epoxy equivalent does not become 2000 g / eq or less.

In addition, when the proportion of the aldehyde-based condensable resin exceeds 100 parts by weight, the epoxy resin reaction product when gelling or otherwise becoming too high in viscosity to form a foam is obtained. Fluidity is reduced, moldability for molding into a predetermined shape is deteriorated, and a foam having desired dimensions and density may not be obtained. That is, from the viewpoint of the flame retardancy of the foam, the reactivity with phosphoric acids, etc., and the ease of controlling the viscosity of the epoxy resin reaction product, the more preferable ratio of both is aldehyde-based to 100 parts by weight of the epoxy resin. It is 10 to 100 parts by weight of the condensable resin.

In the case where a solid aldehyde-based condensable resin is used as a raw material,
When mixed with an epoxy resin after heating and melting, or when a liquid aldehyde-based condensable resin is used, it can be obtained by a method of mixing the epoxy resin with the epoxy resin as it is and then heating and reacting.

The reaction temperature in the above reaction is 80 to 200.
C. is preferable, and if the reaction temperature is in this range, the reaction proceeds sufficiently, and the viscosity of the obtained epoxy resin reaction product does not rise so remarkably that a foam cannot be obtained. In consideration of the fluidity of the epoxy resin reaction product at the time of the reaction, it is preferable to react at a relatively low temperature of 80 to 150 ° C. to obtain an epoxy resin reaction product having a lower viscosity.

Further, since the epoxy equivalent of the obtained epoxy resin reaction product varies depending on the ratio of the aldehyde-based condensable resin to the epoxy resin, the reaction temperature and the reaction time, the epoxy equivalent is set to 2000 g / eq or less. What is necessary is just to set those conditions suitably.

The phosphoric acid in the present invention comprises at least one selected from phosphoric acid, polyphosphoric acid and phenylphosphonic acid. The phosphoric acid reacts with the epoxy resin to form a skeleton of a resin foam. At the same time
It is also a component that imparts flame retardancy to the resin foam.

Among the above phosphoric acids, the phosphoric acid is not particularly limited.
%, 85%, or 89%.

As for polyphosphoric acid, various grades are commercially available depending on the content of P ₂ O ₅ .
It can be used without particular limitation, and there is no limitation on phenylphosphonic acid.

As the phosphoric acids, at least one of phosphoric acid, polyphosphoric acid and phenylphosphonic acid may be used, but two or more of them may be used. still,
Since phenylphosphonic acid among the above is a solid, it is preferable to use it in combination with phosphoric acid or polyphosphoric acid, which is a liquid, in order to easily flow during foaming and curing.

The phosphoric acid is considered to react with the epoxy group of the epoxy resin or the reaction product of the epoxy resin and to be taken into the molecular skeleton of the epoxy resin or the reaction product of the epoxy resin. By controlling the use amount to an appropriate amount, it is possible to prevent phosphoric acid from remaining as a free acid in the obtained foam, and therefore, by controlling so, the epoxy resin foam of the present invention can be used. Even when the body is bonded to another material such as metal or wood, a neutralizing agent for preventing corrosion on the metal and discoloration on the wood is not required.

On the other hand, since phosphoric acids rapidly react with the epoxy group of the epoxy resin or the reaction product of the epoxy resin, as described later, both may react simply by mixing to form a foam. it can. However, in some cases, the calorific value due to a rapid reaction with an epoxy group becomes too large, and foaming (vaporization) occurs at once depending on the type of a foaming agent, so that a dense foam may not be formed. In such a case, at least one type of phosphoric acid selected from a phosphate having a hydroxyl group bonded to a phosphorus atom and a phosphoric acid ester is used together with the phosphoric acid in order to control the reaction and suppress the heat generation. It is preferable to use a compound (hereinafter, sometimes simply referred to as a phosphoric acid compound) in combination.

In the present invention, by using the above-mentioned phosphoric acid compound in combination, it is possible to control the reaction with the epoxy group to suppress the calorific value and to produce a good foam. Since it is also a component that imparts flame retardancy to the resin foam, even if it is used in a relatively large amount with respect to the phosphoric acids, there is little risk of lowering the flame retardancy of the obtained resin foam.

In the above-mentioned phosphoric acid compound, at least one hydroxyl group bonded to a phosphorus atom is required to react with an epoxy group of an epoxy resin or an epoxy resin reaction product.
In addition, at least one kind of phosphate or phosphate ester may be used as the phosphoric acid compound, but two or more kinds may be used.

Examples of the phosphate include ammonium dihydrogen phosphate, diammonium hydrogen phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, and phosphoric acid. Examples thereof include calcium dihydrogen, calcium monohydrogen phosphate, aluminum dihydrogen phosphate, and dialuminum hydrogen phosphate. Examples of the phosphate ester include monomethyl phosphate, dimethyl phosphate, monoethyl phosphate, and diethyl phosphate. , Monopropyl phosphate, monoisopropyl phosphate, monobutyl phosphate, monolauryl phosphate, monostearyl phosphate, mono-2-ethylhexyl phosphate, monoindecyl phosphate, and the like.

In the present invention, the phosphoric acid is used in an amount of 5 to 50 parts by weight based on 100 parts by weight of the epoxy resin or the reaction product of the epoxy resin. If the amount of the phosphoric acid is less than 5 parts by weight, The cross-linking of the epoxy resin or the epoxy resin reaction product becomes insufficient, the obtained foam cannot have sufficient rigidity, and the heat of reaction generated by the reaction with the epoxy resin or the epoxy resin reaction product is reduced. Less, foaming (vaporization) of the foaming agent becomes insufficient,
It becomes difficult to obtain a foam having a desired expansion ratio. On the other hand, when the amount of the phosphoric acid exceeds 50 parts by weight, the phosphoric acid often becomes excessive and the ratio of remaining as a free acid in the foam increases, and in this case, the foaming state of the foam is increased. In addition, when the foam comes into contact with metal or wood, the risk of corrosion and discoloration increases.

The amount of phosphoric acid used depends on the purpose of the foam,
It is preferable to adjust the amount to a more appropriate amount depending on the production method and production conditions.For example, when it is inappropriate that phosphoric acids remain as free acids, a relatively small amount within this range may be used. When the amount of heat generated by the reaction is insufficient, it is preferable to use a relatively large amount within this range.

When the above-mentioned phosphoric acid compound is used, the amount of a mixture of the above-mentioned phosphoric acid compound and phosphoric acid (hereinafter, may be simply referred to as a mixture of phosphoric acid or the like) is 100 parts by weight of epoxy resin or epoxy resin reaction product. 5 to 5 parts
It is preferably 0 parts by weight, and the amount of the phosphoric acid compound used relative to the phosphoric acid can be selected depending on the use of the foam, the production method and the production conditions in the same manner as described above. Alternatively, it can be appropriately adjusted so as to obtain an appropriate foam hardening time.

Although not particularly limited, the ratio of phosphoric acid in the above-mentioned mixture of phosphoric acids and the like is preferably 40% by weight or more, and when the amount of phosphoric acid is too small, the mixture with the epoxy resin or the epoxy resin reaction product is used. May become insufficient in reactivity. When a solid phosphoric acid compound is used, it is preferable to use it in combination with a liquid phosphoric acid or polyphosphoric acid in order to facilitate the flow during foaming and curing.

Examples of the blowing agent in the present invention include known ones such as halogenated hydrocarbons and hydrocarbons. Among them, halogenated hydrocarbons having a boiling point of 0 to 100 ° C. are preferable. In particular, halogenated hydrocarbons that are liquid at room temperature are preferred. These foaming agents can be used alone or as a mixture of two or more.

Examples of the halogenated hydrocarbons include chlorinated hydrocarbons such as methylene chloride and trichloroethylene; 2,2-dichloro-1,1,1-trifluoroethane (HCFC123); -1-fluoroethane (HCFC141b), 1,1-dichloro-2,2,3,3,3-pentafluoropropane (HC
FC225ca), 1,3-dichloro-1,1,2,2
2,3-pentanefluoropropane (HCFC225c
b) chlorinated fluorinated hydrocarbons such as 1,1,1,2,2
3,3-hexafluoropropane (HFC236e
a) and fluorinated hydrocarbons such as 1,1,1,3,3-pentafluoropropane (HFC245fa).

In the present invention, the foaming agent is used in an amount of from 1 to 50 parts by weight based on 100 parts by weight of the epoxy resin or the epoxy resin reaction product. If it exceeds 50 parts by weight, the number of open cells increases, the closed cell ratio decreases, and the rigidity and heat insulation of the foam decrease.

Further, since the expansion ratio and density of the foam are changed by increasing or decreasing the amount of the foaming agent used, the amount of the foaming agent is adjusted so that the foam density required according to the use of the foam is obtained. Adjustment is preferred.

Examples of the foam stabilizer in the present invention include known ones used for producing various resin foams such as polyurethane resin foams and phenol resin foams.

As the foam stabilizer, a surfactant is preferable, and more preferably, a nonionic surfactant is used as the surfactant. These foam stabilizers may be used alone or in combination of two or more.

Examples of the nonionic surfactant which can be used as the above foam stabilizer include sorbitan esters such as sorbitan monostearate, sorbitan monooleate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan monooleate. Polyethylene glycol esters such as polyethylene glycol monostearate, polyethylene glycol monosoleate, polyethylene glycol distearate, and polyethylene glycol dioleate; polyoxyethylene alkyl ethers other than those described above; polyoxyethylene alkyl esters; polyoxyethylene Alkylphenyl ethers; polyoxyethylene alkylphenyl esters, dimethylpolysiloxane polyoxyalkylene copolymers, etc. It can gel.

In the present invention, the foam stabilizer is used in an amount of 0.01 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the epoxy resin or the epoxy resin reaction product. If the amount is less than 0.01 part by weight, the effect of uniformizing the size and distribution of foam after foaming is lacking, and if it exceeds 10 parts by weight, it acts as a plasticizer and reduces the rigidity of the foam. Would.

In the present invention, fillers and pigments may be used for the purpose of adjusting the fluidity and the like at the time of foaming hardening and for economical effects. Examples of such fillers and pigments include, for example,
Calcium carbonate, talc, kaolin, bentonite, mica, sericite, zeolite, silica, silica fume, silica sand, perlite, shirasu balloon, titanium oxide, carbon black, phthalocyanine, etc., and these fillers and pigments are necessary Can be used by mixing with an epoxy resin or the like using a kneader, a mixing roll, a Henschel mixer, or the like.

The epoxy resin according to the first embodiment of the present invention, or the reaction product of the epoxy resin according to the second embodiment of the present invention, and a phosphoric acid or a mixture of phosphoric acids, etc.
Normally, the reaction occurs at room temperature. Therefore, in the method for producing an epoxy resin-based foam of the present invention, an epoxy resin or an epoxy resin reaction product is mixed with a phosphoric acid or a mixture of phosphoric acids at room temperature to form a reactive mixture. Preferably, the mixture is a mixture. However, when the epoxy resin or the reaction product of the epoxy resin is a high-viscosity liquid, the mixture of the epoxy resin or the reaction product of the epoxy resin and phosphoric acid or a mixture of phosphoric acids is heated. It can also be done below.

An aldehyde-based condensable resin, a foaming agent or a foam stabilizer (the first embodiment of the present invention), or a foaming agent or a foam stabilizer (the second embodiment of the present invention) comprises an epoxy resin or an epoxy resin reaction. When the product is mixed with a phosphoric acid or a mixture of phosphoric acids and the like, they can be mixed with these at the same time. At least one of the two can be mixed with the above-mentioned components in advance, and can be mixed in advance. When preparatory, it is mixed with an epoxy resin or a component containing an epoxy resin reaction product to make a premix, and the premix is mixed with a component containing a mixture of phosphoric acids or phosphoric acids for ease of mixing. Preferably, it is a reactive mixture.

Epoxy resin, aldehyde condensable resin,
A reactive mixture containing phosphoric acid or a mixture of phosphoric acid, a foaming agent and a foam stabilizer (the first embodiment of the present invention), or an epoxy resin reaction product, a mixture of phosphoric acid or phosphoric acid, a foaming agent, and a foaming agent The reactive mixture containing the foaming agent (the second embodiment of the present invention) can start the reaction at room temperature, the reaction proceeds while generating heat, and foams due to the vaporization of the foaming agent, and the reaction hardens. An epoxy resin-based foam is used, and as a device that mixes such components and discharges and injects the mixture, a multi-component mixer that is commonly used in the production of polyurethane resin foam and the like is called a multi-component mixer. It is preferred to use a mixing device that is known.

As a method of molding the epoxy resin foam obtained by the present invention into a desired shape, there is a method of injecting and foaming the mixture by injecting the raw material components into a mold of a desired size and shape while mixing. Or a slab foaming method or the like in which the raw material components are mixed and flowed on a flat surface, and before the mixture is cured, the surface of the mixture during foaming and curing is scraped to a predetermined thickness by a doctor blade or the like, and the mixture is cured. Can be.

The epoxy resin foam obtained according to the present invention can be used for the same applications as conventional resin foams. For example, the foam obtained by the slab foaming method is cut out into a desired shape by cutting out a foamed body, and it can be used for applications such as a plate-shaped heat insulating material used for a building such as a house such as a housing such as an underfloor heat insulating material. Also, it can be used for a heat insulating material by foaming between an inner wall and an outer wall of a building such as a refrigerated warehouse by an injection foaming method. Further, it can be used as a core material of a door or a sandwich panel, and can be made into a composite material such as synthetic wood by impregnating a reinforcing fiber such as a glass fiber with a mixture of the above-mentioned raw materials while foaming and curing the mixture.

[0064]

A reactive mixture containing an epoxy resin, an aldehyde-based condensable resin, phosphoric acid or a mixture of phosphoric acids, a foaming agent and a foam stabilizer (first embodiment of the present invention), or an epoxy resin reaction product Mixture, a phosphoric acid or a mixture of phosphoric acids, a foaming agent and a foam stabilizer (a second embodiment of the present invention) react rapidly at room temperature to generate heat. The epoxy resin foam can be easily and quickly cured at room temperature without heating a mixture of an epoxy resin or an epoxy resin reaction product and phosphoric acid or a mixture of phosphoric acids, etc., by utilizing the vaporization of the agent. Obtainable.

Further, since phosphoric acid reacts and is taken into the resin skeleton constituting the resin foam, the phosphoric acid functions in the same manner as the reactive flame retardant, and the epoxy resin foam having high flame retardancy. You can get the body.

Further, since the aldehyde-based condensable resin increases the degree of crosslinking of the epoxy resin, an epoxy resin-based foam having excellent heat resistance and flame retardancy can be obtained.

[0067]

The present invention will be described in more detail with reference to the following examples.

Example 1 100 parts by weight of a bisphenol A diglycidyl ether epoxy resin having an epoxy equivalent of 180 g / eq
X-component obtained by adding 50 parts by weight of powdery trimethylolphenol as an aldehyde-based condensable resin and 2 parts by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer is used as a raw material for a multi-component mixed foaming machine. Put in the tank. Next, 85% phosphoric acid for industrial use is used as the Y component,
Put in another raw material tank. Then, 1 as a foaming agent
1-Dichloro-1-fluoroethane was used as the Z component, and was placed in another raw material tank. X, Y, and Z components are represented by X:
At a discharge weight ratio of Y: Z = 150: 30: 10, the mixture was fed into the mixing head at a total flow rate of 3 kg / min to discharge a reactive mixture. When 1250 g of this reactive mixture was immediately placed in a 500 × 500 × 100 mm room temperature metal frame, foaming started 30 seconds after injection, and foaming hardening was completed 4 minutes 30 seconds later.

Example 2 80 parts by weight of powdery hexamethylol melamine as an aldehyde-based condensable resin with respect to 100 parts by weight of a phenol novolak polyglycidyl ether-based epoxy resin having an epoxy equivalent of 175 g / eq and a molecular weight of about 600; What added 1 part weight of dimethylpolysiloxane polyoxyalkylene copolymer as a foam stabilizer was made into X component, and was put into the raw material tank of the multi-component mixing foaming machine. Next, P
_A mixture of polyphosphoric acid and aluminum dihydrogen phosphate (76% in terms of ₂ O ₅₎ in a weight ratio of 3: 2 was used as a Y component and placed in another raw material tank. Subsequently, a mixture of methylene chloride as a foaming agent and 1,1-dichloro-2,2,3,3,3-pentafluoropropane at a weight ratio of 4: 1 was used as a Z component, and further another raw material was used. Put in the tank. X, Y,
Each component of Z was fed into the mixing head at a discharge weight ratio of X: Y: Z = 180: 50: 15 at a total flow rate of 3 kg / min to discharge a reactive mixture. When 1250 g of this reactive mixture was immediately placed in a 500 × 500 × 100 mm room temperature metal frame, foaming started 30 seconds after injection, and foaming hardening was completed 5 minutes 30 seconds later.

Example 3 A powdery resol type aldehyde condensable resin obtained by adding 2 mol of formaldehyde to 1 mol of phenol to 100 parts by weight of bisphenol A diglycidyl ether epoxy resin having an epoxy equivalent of 180 g / eq. After mixing 50 parts by weight of the phenol resin, the mixture was reacted at 120 ° C. for 4 hours to give an epoxy equivalent of about 800 g / eq.
A viscous liquid epoxy resin reaction product was obtained. To 100 parts by weight of the reaction product, 2 parts by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer, and
What added 25 parts by weight of 1,1-dichloro-1-fluoroethane as a foaming agent was designated as X component, and was placed in a raw material tank of a multi-component mixed foaming machine. Next, 85% phosphoric acid for industrial use was used as the Y component and placed in another raw material tank. The X and Y components were fed into the mixing head at a discharge weight ratio of X: Y = 127: 20 at a total flow rate of 3 kg / min to discharge a reactive mixture. When 1250 g of the reactive mixture was immediately placed in a 500 × 500 × 100 mm room-temperature metal frame, foaming started 20 seconds after the injection, and foam hardening was completed 4 minutes later.

Example 4 Powder as aldehyde condensable resin obtained by adding 2.2 mol of formaldehyde to 1 mol of melamine to 100 parts by weight of diglycidyl hexahydrophthalate epoxy resin having an epoxy equivalent of 140 g / eq. After mixing 80 parts by weight of the amino resin, the mixture was reacted at 100 ° C. for 2 hours to obtain a viscous liquid epoxy resin reaction product having an epoxy equivalent of about 1300 g / eq. To 100 parts by weight of this reaction product, 3 parts by weight of a dimethylpolysiloxane polyoxyalkylene copolymer as a foam stabilizer, and methylene chloride and 1,1-dichloro-2,
X component obtained by adding 25 parts by weight of a mixture of 2,3,3,3-pentafluoropropane at a weight ratio of 4: 1 was added to a raw material tank of a multi-component mixed foaming machine. next,
A mixture of polyphosphoric acid (76% in terms of P ₂ O ₅ ) and aluminum dihydrogen phosphate hexahydrate at a weight ratio of 5: 1 was used as a Y component and placed in another raw material tank. The X and Y components were fed into the mixing head at a discharge weight ratio of X: Y = 128: 15 at a total flow rate of 3 kg / min to discharge a reactive mixture. 1250 g of this reactive mixture is immediately added to 5
When placed in a metal frame at room temperature of 00 × 500 × 100 mm, foaming started 1 minute after injection, and foaming hardening was completed 5 minutes later.

Example 5 An aldehyde-based condensable resin was prepared by adding 2.5 mol of formaldehyde to 1 mol of urea to 100 parts by weight of a phenol novolak polyglycidyl ether-based epoxy resin having an epoxy equivalent of 175 g / eq and a molecular weight of about 600. After mixing 20 parts by weight of the powdery amino resin of
C. for 2 hours at an epoxy equivalent of about 450 g /
A viscous and liquid epoxy resin reaction product of eq was obtained.
To 100 parts by weight of the reaction product, 1 part by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer and 20 parts by weight of 1,1-dichloro-1-fluoroethane as a foaming agent were added to X The components were placed in a raw material tank of a multi-component mixed foaming machine. Next, a mixture of industrial 89% phosphoric acid and phenylphosphonic acid at a weight ratio of 3: 1 was used as the Y component and placed in another raw material tank. X, Y
Were fed into the mixing head at a discharge weight ratio of X: Y = 121: 20 at a total flow rate of 3 kg / min to discharge a reactive mixture. 1250 g of this reactive mixture
Was immediately placed in a 500 × 500 × 100 mm room temperature metal frame, foaming started 20 seconds after injection, and foam hardening was completed 5 minutes later.

Example 6 A powdery amino resin as an aldehyde condensable resin obtained by adding 2 mol of formaldehyde to 1 mol of benzoguanamine to 100 parts by weight of a bisphenol A diglycidyl ether epoxy resin having an epoxy equivalent of 180 g / eq. After mixing 40 parts by weight, the mixture was reacted at 150 ° C. for 4 hours to obtain a viscous liquid epoxy resin reaction product having an epoxy equivalent of about 800 g / eq. 100 parts by weight of this reaction product, 1 part by weight of a dimethylpolysiloxane polyoxyalkylene copolymer as a foam stabilizer, and 1,1-dichloro-1-fluoroethane 25 as a foaming agent
The X-component obtained by adding parts by weight was placed in a raw material tank of a multi-component mixed foaming machine. Next, a mixture of industrial 89% phosphoric acid and monomethyl phosphate at a weight ratio of 4: 1 was used as the Y component and placed in another raw material tank. The X and Y components were fed into the mixing head at a discharge weight ratio of X: Y = 126: 8 at a total flow rate of 3 kg / min to discharge a reactive mixture. When 1250 g of this reactive mixture was immediately placed in a 500 × 500 × 100 mm room temperature metal frame, foaming started 1 minute and 30 seconds after injection, and foam hardening was completed 10 minutes later.

Comparative Example 1 100 parts by weight of a bisphenol A diglycidyl ether-based epoxy resin having an epoxy equivalent of 180 g / eq
A raw material tank of a multi-component mixing and foaming machine was prepared by adding 400 parts by weight of liquid trimethylolphenol as an aldehyde-based condensable resin and 2 parts by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer as an X component. Put in. Next, 85% phosphoric acid for industrial use is used as the Y component,
Put in another raw material tank. Then, 1 as a foaming agent
1-Dichloro-1-fluoroethane was used as the Z component, and was placed in another raw material tank. X, Y, and Z components are represented by X:
At a discharge weight ratio of Y: Z = 500: 60: 10, the mixture was fed into the mixing head at a total flow rate of 3 kg / min to discharge the reactive mixture. Immediately after placing 1125 g of the reactive mixture in a metal frame of 500 × 500 × 100 mm at room temperature, the cured product was not completely cured and a somewhat tacky foam was obtained.

Comparative Example 2 Trimethylolphenol aqueous solution 1 having a solid content of 65% by weight
Bisphenol A diglycidyl ether-based epoxy resin 2 having an epoxy equivalent of 180 g / eq per 100 parts by weight
A mixture obtained by adding 0 parts by weight and 2 parts by weight of a dimethylpolysiloxane polyoxyalkylene copolymer as a foam stabilizer was designated as an X component, and was placed in a raw material tank of a multi-component mixing foaming machine. Next, a mixture of p-toluenesulfonic acid as a curing agent and 1,1-dichloro-1-fluoroethane as a foaming agent at a weight ratio of 2:10 was used as a Y component, and put in another raw material tank. Was. X: Y = X: Y = 30:
With a discharge weight ratio of 10, a total of 3 kg /
min and the reactive mixture was discharged. 1250 g of this reactive mixture was immediately added to 500 × 500 × 1
When placed in a metal frame at room temperature of 00 mm, foaming started 1 minute after injection, and foaming hardening was completed 10 minutes later.

Comparative Example 3 100 parts by weight of a bisphenol A diglycidyl ether-based epoxy resin having an epoxy equivalent of 180 g / eq
X-component obtained by adding 50 parts by weight of powdery trimethylolphenol as an aldehyde-based condensable resin and 2 parts by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer is used as a raw material for a multi-component mixed foaming machine. Put in the tank. Next, triethylenetetramine as a curing agent was used as a Y component, and was placed in another raw material tank. continue,
1,1-Dichloro-1-fluoroethane as a foaming agent was used as a Z component, and was placed in another raw material tank. X, Y,
Each component of Z was fed into the mixing head at a discharge weight ratio of X: Y: Z = 150: 13: 10 at a total flow rate of 3 kg / min to discharge a reactive mixture. When 1250 g of the reactive mixture was immediately put in a metal frame of 500 × 500 × 100 mm at room temperature, foaming started 10 minutes after injection, but a foam of a predetermined size was not obtained.

Comparative Example 4 To 100 parts by weight of a bisphenol A diglycidyl ether epoxy resin having an epoxy equivalent of 180 g / eq, 2 mol of formaldehyde was added to 1 mol of melamine.
Amino resin in powder form as aldehyde-based condensable resin 5
After mixing 0 parts by weight, the mixture was reacted at 150 ° C. for 5 hours to obtain a viscous liquid epoxy resin reaction product having an epoxy equivalent of about 1400 g / eq. This reaction product 10
The X component was obtained by adding 2 parts by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer to 0 parts by weight, and the mixture was placed in a raw material tank of a multi-component mixed foaming machine. next,
85% phosphoric acid for industrial use was used as the Y component and placed in another raw material tank. Subsequently, 1,1-dichloro-1- as a foaming agent
Fluoroethane was used as the Z component, and was placed in another raw material tank. X: Y: Z: X: Y: Z = 100: 6
0K: 15 discharge weight ratio, total 3K for mixing head
The reaction mixture was fed at a flow rate of g / min and discharged. 1250 g of this reactive mixture was immediately added to 500 × 50
When placed in a 0 × 100 mm room temperature metal frame, foaming started 30 seconds after injection and foaming hardening was completed 4 minutes later. However, the obtained foam had a non-uniform cell size and distribution, and had large voids in the foam.

Comparative Example 5: 100 parts by weight of a bisphenol A diglycidyl ether epoxy resin having an epoxy equivalent of 180 g / eq.
After mixing 5 parts by weight of triethylenetetramine as a curing agent, the mixture was reacted at 80 ° C. for 2 hours to obtain a viscous liquid epoxy resin reaction product having an epoxy equivalent of about 900 g / eq. A product obtained by adding 1 part by weight of a dimethylpolysiloxane polyoxyalkylene copolymer as a foam stabilizer and 20 parts by weight of 1,1-dichloro-1-fluoroethane as a foaming agent to 100 parts by weight of the reaction product. To X
The components were placed in a raw material tank of a multi-component mixed foaming machine. Next, 85% phosphoric acid for industrial use was used as the Y component and placed in another raw material tank. The components X and Y were fed into the mixing head at a discharge weight ratio of X: Y = 121: 30 at a total flow rate of 3 kg / min to discharge a reactive mixture. Immediately, 1250 g of this reactive mixture was 500 × 500 × 100 mm
However, the epoxy resin reaction product was decomposed during foaming and curing, and a foam could not be obtained.

Comparative Example 6 Powder as aldehyde condensable resin obtained by adding 2 mol of formaldehyde to 1 mol of phenol to 100 parts by weight of phenol novolak polyglycidyl ether epoxy resin having an epoxy equivalent of 175 g / eq and a molecular weight of about 600 The mixture was mixed with 150 parts by weight of a resole type phenol resin and reacted at 150 ° C. for 5 hours to obtain an extremely viscous and liquid epoxy resin reaction product having an epoxy equivalent of about 3200 g / eq. To 100 parts by weight of this reaction product, 2 parts by weight of a dimethylpolysiloxane polyoxyalkylene copolymer as a foam stabilizer, methylene chloride as a foaming agent, and 1,1-dichloro-2,2,3,3,3
A mixture of pentafluoropropane and pentafluoropropane at a weight ratio of 1: 1 to which 25 parts by weight was added was designated as an X component, and the mixture was placed in a raw material tank of a multi-component mixed foaming machine. Next, 89% for industrial use
A mixture of phosphoric acid and phenylphosphonic acid at a weight ratio of 3: 1 was used as the Y component and placed in another raw material tank. X,
Each component of Y was fed to the mixing head at a discharge weight ratio of X: Y = 127: 25 at a total flow rate of 3 kg / min to discharge a reactive mixture. This reactive mixture 1250
g was immediately placed in a 500 × 500 × 100 mm room temperature metal frame. However, the viscosity of the epoxy resin reaction product was too high, so that the reactive mixture did not flow sufficiently and a foam of a predetermined size was obtained. However, a partially foamed lump was obtained.

Comparative Example 7 A powdery resol type aldehyde condensable resin was prepared by adding 2 mol of formaldehyde to 1 mol of phenol to 100 parts by weight of bisphenol A diglycidyl ether epoxy resin having an epoxy equivalent of 180 g / eq. After mixing 20 parts by weight of the phenol resin, the mixture was reacted at 150 ° C. for 4 hours to obtain an epoxy equivalent of about 500 g / eq.
A viscous liquid epoxy resin reaction product was obtained. 1 part by weight of a dimethylpolysiloxane polyoxyalkylene copolymer as a foam stabilizer was added to 100 parts by weight of the reaction product,
And what added 55 parts by weight of 1,1-dichloro-1-fluoroethane as a foaming agent was designated as X component, and was put in a raw material tank of a multi-component mixed foaming machine. Next, 89% for industrial use
A mixture of phosphoric acid and aluminum dihydrogen phosphate hexahydrate at a weight ratio of 4: 1 was used as the Y component and placed in another raw material tank. The components X and Y were fed into the mixing head at a discharge weight ratio of X: Y = 156: 4 at a total flow rate of 3 kg / min to discharge a reactive mixture. 1250 g of this reactive mixture was immediately placed in a 500 × 500 × 100 mm room temperature metal frame.
Starting in seconds, the foam hardening was complete after 5 minutes. However, the obtained foam was insufficiently cured and left tackiness. Further, since the foaming agent was liquefied when the foam was allowed to cool, 1,1-dichloro-1-fluoroethane remained in the cells of the foam.

The physical properties of the foams obtained by the above Examples and Comparative Examples are shown in Table 1 below.

[Table 1]

[0082]

According to the method for producing an epoxy resin foam of the present invention, as shown in the above examples, foaming and curing easily and quickly at room temperature, and a highly rigid and dense flame-retardant epoxy resin. A foam can be obtained.

In the epoxy resin foam obtained by the present invention, phosphoric acid and the like are incorporated in the resin skeleton constituting the foam, and the epoxy resin and the aldehyde-based condensable resin are combined. Excellent flame retardancy.

────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C08L 63/00 C08L 63/00 // E04B 1/94 E04B 1/94 T (56) References JP-A-55-82133 (JP) JP-A-1-197553 (JP, A) JP-A-4-178440 (JP, A) JP-A-59-138218 (JP, A) JP-A-56-163164 (JP, A) JP-A-51-58465 (JP, A) JP-A-51-66359 (JP, A) JP-A-5-86310 (JP, A) JP-A-51-41028 (JP, A) A) JP-A-51-28829 (JP, A) JP-B-46-28303 (JP, B1) JP-B-47-14717 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) C08J 9/00-9/42 E04B 1/94 C08G 59/00-59/72 C08L 1/00-101/14 C09D 1/00-201/10

Claims (6)

(57) [Claims] 1. A method for producing an epoxy resin foam, comprising: foaming and curing a mixture containing the following components A to E at the following quantitative ratios. A: Epoxy resin having two or more epoxy groups in a molecule: 100 parts by weight B: Aldehyde-based condensable resin: 5 to 300 parts by weight C: From phosphoric acid, polyphosphoric acid and phenylphosphonic acid At least one selected phosphoric acid: 5 to 50 parts by weight D: foaming agent: 1 to 50 parts by weight E: foam stabilizer: 0.01 to 10 parts by weight 2. A method for producing an epoxy resin foam, comprising foaming and curing a mixture containing the following components A to E in the following quantitative ratios. A: Epoxy resin having two or more epoxy groups in a molecule: 100 parts by weight B: Aldehyde-based condensable resin: 5 to 300 parts by weight C ': Among phosphoric acid, polyphosphoric acid and phenylphosphonic acid A mixture of at least one phosphoric acid selected from the group consisting of at least one phosphoric acid compound selected from a phosphate and a phosphate having a hydroxyl group bonded to a phosphorus atom: 5 to 50 parts by weight D: Blowing agent: 1 to 50 parts by weight E: Foam stabilizer: 0.01 to 10 parts by weight 3. A method for producing an epoxy resin-based foam, comprising foaming and curing a mixture containing the following components F to I in the following quantitative ratios. F: obtained by reacting an epoxy resin having two or more epoxy groups in a molecule with an aldehyde-based condensable resin,
Liquid reaction product having an epoxy equivalent of 2000 g / eq or less: 100 parts by weight G: at least one phosphoric acid selected from phosphoric acid, polyphosphoric acid and phenylphosphonic acid: 5 to 50 parts by weight H : Foaming agent: 1 to 50 parts by weight I: foam stabilizer: 0.01 to 10 parts by weight 4. A method for producing an epoxy resin foam, comprising foaming and curing a mixture containing the following components F to I at the following quantitative ratios. F: obtained by reacting an epoxy resin having two or more epoxy groups in a molecule with an aldehyde-based condensable resin,
Liquid reaction product having an epoxy equivalent of 2000 g / eq or less: 100 parts by weight G ': At least one phosphoric acid selected from phosphoric acid, polyphosphoric acid and phenylphosphonic acid, and bound to a phosphorus atom A mixture comprising at least one phosphoric acid compound selected from a phosphate having a hydroxyl group and a phosphoric acid ester 5 to 50 parts by weight H: foaming agent 1 to 50 parts by weight I: foam stabilizer・ 0.01 to 10 parts by weight 5. The epoxy resin according to claim 1, wherein the epoxy resin is at least one selected from a glycidyl ether epoxy resin, a glycidyl ester epoxy resin, and a cycloaliphatic epoxy resin. A method for producing a foam. 6. The method for producing an epoxy resin foam according to claim 1, wherein the aldehyde-based condensable resin is a solid or powdery resin.