JP3196019B2 - Epoxy resin foam and method for producing the same - 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 epoxy resin foam and a method for producing the same, and more particularly, to a highly rigid and dense epoxy resin foam having flame retardancy, and The present invention relates to a method for producing the epoxy resin foam which can be foam-cured at room temperature.

[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, JP-A-58-120624 and JP-A-58-120644 disclose that a resol type phenol resin, an epoxy resin, an acid catalyst and a foaming agent are used, A foam having a molar ratio of 0.06 to 0.3 mol per 100 g of the phenol resin is disclosed in Japanese Patent Application Laid-Open No. 55-821.
No. 33 discloses a foamed material comprising a resol type phenol resin, an epoxy resin, a foaming agent, a catalyst, a reinforcing material, and a filler.

Further, in order to take advantage of the properties of an epoxy resin such as excellent adhesion to other materials, heat resistance, chemical resistance, dimensional stability, and mechanical strength, a foamable resin composition based on an epoxy resin is used. For example, JP-A-1-197553 discloses that a foam can be obtained at room temperature by blending an epoxy resin, an amine-based curing agent, a curing accelerator, and an inorganic filler. Has been described.

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

Further, JP-A-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 are compounded. Obtained
A foamable resin composition capable of being thermally foamed is disclosed.

Further, 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.

[0008] 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.

[0009]

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.

[0010] The resol type phenol resin uses an organic acid such as p-toluenesulfonic acid as a curing catalyst. However, since the acid remains in the foam, it causes corrosion of the contacting metal and discoloration of wood. Therefore, as shown in the prior art (see, for example, Japanese Patent Application Laid-Open No. 58-120644), the remaining organic acid reacts with the epoxy resin to be collected, and the remaining acid is used as another material. It is necessary to prevent the influence on the foam and modify the foam.

Furthermore, since the resole type phenol resin releases formaldehyde in the process of foaming and curing, there is a case where there is a problem that the working environment is impaired by the odor.

On the other hand, epoxy resins are superior to phenol resins in adhesiveness 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 and 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, or the thermal conductivity is increased and the heat insulating performance is reduced, the amount of addition is limited, and as a result, there is a problem that the flame retardancy becomes insufficient.

Therefore, as a method of 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 drawbacks of the prior art, and provides an epoxy resin foam having high rigidity, high density and good adhesion to other materials, and without heating. The object of the present invention is to provide a method for producing the epoxy resin foam which can be foam-cured at room temperature.

[0016]

Means for Solving the Problems In order to achieve the above object, the structure of an epoxy resin foam employed by the present invention comprises an epoxy resin having two or more epoxy groups in a molecule and a novolak type phenol resin. 100 parts by weight of a liquid reaction product having an epoxy equivalent of 2000 g / eq or less obtained by the reaction of the above, and 5 to 50 parts by weight of at least one phosphoric acid selected from phosphoric acid, polyphosphoric acid and phenylphosphonic acid; Alternatively, at least one phosphoric acid selected from phosphoric acid, polyphosphoric acid and phenylphosphonic acid, and at least one phosphoric acid compound selected from phosphate and phosphate having a hydroxyl group bonded to a phosphorus atom Characterized by having a resin skeleton obtained by reacting 5 to 50 parts by weight of a mixture consisting of

Similarly, 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 steps of foaming and curing a mixture containing the following components A to D in the following quantitative ratios. It is characterized by the following.

A: 100 parts by weight of a liquid reaction product having an epoxy equivalent of 2000 g / eq or less obtained by reacting an epoxy resin having two or more epoxy groups in a molecule with a novolak-type phenolic resin : At least one phosphoric acid selected from phosphoric acid, polyphosphoric acid and phenylphosphonic acid ... 5 to 50 parts by weight, or B ': at least selected from phosphoric acid, polyphosphoric acid and phenylphosphonic acid A mixture of one kind of phosphoric acid and at least one kind of 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 C: foaming agent 1 to 50 parts by weight D: foam stabilizer: 0.01 to 10 parts by weight

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The epoxy resin in the present invention is a compound having two 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 in view of the ease of mixing with the flame retardant and the fluidity during foaming. Examples of such an epoxy resin include bisphenol A diglycidyl. Glycidyl ether epoxy resins such as ether, bisphenol F diglycidyl ether, 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-
Examples thereof include cycloaliphatic epoxy resins such as epoxy-6-methylcyclohexylmethylcarboxylate and 3,4-epoxycyclohexylmethylcarboxylate.

The novolak type phenolic resin in the present invention is a compound consisting of a partial condensate of phenols (an aromatic compound having one or more hydroxyl groups in an aromatic nucleus) and formaldehyde, and the aromatic nucleus of the aromatic compound. Is said to have a structure linked by a methylene group.

This novolak-type phenolic resin is obtained by reacting formaldehyde with phenols in an equimolar amount or more in the presence of an acid catalyst. For example, 1 to 2 mol of formaldehyde and 1 mol of phenols are reacted with each other. Are condensed in the presence of an acid catalyst. Among them, those in which the degree of condensation is suppressed so that the melting point is in the range of 80 to 120 ° C are preferable. The novolak type phenolic resin is a compound having a heat melting property and can be cured by a curing agent such as hexamethylenetetramine.

The aromatic nucleus in the above-mentioned phenols is preferably a benzene nucleus, and the aromatic nucleus may have a substituent such as a hydroxyl group or an alkyl group. Examples of such phenols include compounds having one or two hydroxyl groups on a benzene nucleus such as phenol, cresol, xylenol, and resorcinol.

The novolak type phenolic resin used as a curing agent for the epoxy resin is usually 80 to 12%.
It melts at a temperature of 0 ° C. and causes a curing reaction at a temperature of 150 to 200 ° C. Therefore, any novolak-type phenolic resin used as a curing agent for such an epoxy resin can be used without any problem in the present invention. be able to.

The reaction product obtained by the reaction between the epoxy resin and the novolak-type phenolic resin in the present invention (hereinafter sometimes simply referred to as an epoxy resin reaction product) may further react with phosphoric acids and the like described below. It is necessary that the epoxy resin has an epoxy group, and therefore, in the present invention, the epoxy resin reaction product has an epoxy equivalent of 2000 g.
/ Eq is used. 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 500 to 14
It is particularly preferred that it is 00 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. Any liquid having a high viscosity may be used as long as it becomes a liquid having a relatively low viscosity under heating.

The ratio of the epoxy resin and the novolak type phenolic resin to obtain the above epoxy resin reaction product by reacting the epoxy resin with the novolak type phenolic resin is 1 to 100 parts by weight of the epoxy resin. Preferably it is 60 parts by weight. If the ratio of the novolak type phenolic resin to 100 parts by weight of the epoxy resin is less than 1 part by weight, the flame retardancy of the obtained resin foam tends to deteriorate, and conversely, the ratio of the novolak type phenolic resin is 60 parts by weight. If it exceeds 3, the amount of epoxy groups in the produced epoxy resin reaction product will decrease, and the number of epoxy groups for reacting with phosphoric acids and the like described below will decrease, and the epoxy equivalent may not be less than 2000 g / eq.

In addition, when the proportion of the novolak-type phenolic resin exceeds 60 parts by weight, the epoxy resin reaction product when gelling or otherwise becomes too high in viscosity to form a foam. 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, in view of the flame retardancy of the foam, the reactivity with phosphoric acids, etc., and the easy control of the viscosity of the epoxy resin reaction product, the more preferable ratio of both is novolak type with respect to 100 parts by weight of the epoxy resin. It is 10 to 40 parts by weight of the phenolic resin.

As a method for obtaining the above-mentioned epoxy resin reaction product, a novolak-type phenol-based resin is heated and melted and then mixed with an epoxy resin to cause a reaction. Alternatively, the epoxy resin and the novolak-type phenol-based resin are mixed and then heated. Then, a method of melting and reacting the novolak type phenolic resin is preferable. Reaction temperature is 120-1
When the reaction temperature is within 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 120 to 140 ° C. to obtain an epoxy resin reaction product having a lower viscosity.

When the epoxy resin is reacted with the novolak type phenolic resin, a tertiary amine-based, phosphate-based or imidazole-based catalyst may be used.

Further, the epoxy equivalent of the obtained epoxy resin reaction product varies depending on the ratio of the novolak type phenolic resin to the epoxy resin, the reaction temperature and the reaction time, so that the epoxy equivalent is 2,000 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 above-mentioned epoxy resin reaction product to form a resin foam. At the same time as forming the skeleton, 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 of polyphosphoric acid 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 acid, at least one kind of phosphoric acid, polyphosphoric acid and phenylphosphonic acid may be used, but two or more kinds may be used. still,
Since phenylphosphonic acid in the above phosphoric acids is solid, it is preferable to use it in combination with liquid phosphoric acid or polyphosphoric acid in order to facilitate fluidity during foaming and curing.

It is considered that the phosphoric acid reacts with the epoxy group of the epoxy resin reaction product and is taken into the molecular skeleton of the epoxy resin reaction product. Therefore, the amount of the phosphoric acid is adjusted to an appropriate amount. By controlling, phosphoric acids can be prevented from remaining as free acids in the obtained foam. Therefore, by controlling in such a manner, even when the epoxy resin foam of the present invention is bonded to other materials such as metal and wood, for example, a neutralizing agent for preventing corrosion to metal and discoloration to wood is used. do not need.

On the other hand, since phosphoric acid reacts rapidly with the epoxy group of the epoxy resin reaction product, as described later, both can react simply by mixing to form a foam. However, in some cases, the calorific value due to the rapid reaction with the epoxy group becomes too large, and foaming (vaporization) occurs at a stroke depending on the type of foaming agent.
There is a possibility that a dense foam cannot 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 phosphoric acid compound together, the reaction with the epoxy group is controlled to suppress the calorific value, thereby making it possible to produce good foams. 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 reaction product.
As the phosphoric acid compound, at least one kind of phosphate or phosphate ester may be used, 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 Calcium dihydrogen, calcium monohydrogen phosphate, aluminum dihydrogen phosphate, dialuminum hydrogen phosphate, and the like, and examples of the phosphate ester include monomethyl phosphate, dimethyl phosphate, monoethyl phosphate, diethyl phosphate, Examples thereof include monopropyl phosphate, monoisopropyl phosphate, monobutyl phosphate, monolauryl phosphate, monostearyl phosphate, mono-2-ethylhexyl phosphate, and monoisodecyl phosphate.

In the present invention, the above-mentioned phosphoric acid is used in an amount of 5 to 50 parts by weight based on 100 parts by weight of the epoxy resin reaction product. Cross-linking of the product becomes insufficient,
The resulting foam cannot have sufficient rigidity,
Also, the reaction heat generated by the reaction with the epoxy resin reaction product is small, and the foaming agent is insufficiently foamed (vaporized), making it 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 the epoxy resin reaction product. It is preferably 5 to 50 parts by weight, and the amount of the phosphoric acid compound relative to the phosphoric acid can be selected according to the use of the foam, the production method and the production conditions as described above. It can be appropriately adjusted so as to obtain an appropriate foam curing time.

Although not particularly limited, the proportion 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 reactivity with the epoxy resin reaction product is reduced. May be insufficient. When a solid phosphoric acid compound is used, it is preferably used in combination with a liquid phosphoric acid or polyphosphoric acid in order to facilitate the flow during foaming and curing.

Examples of the foaming 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.

The halogenated hydrocarbons include, for example, 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), 3-Dichloro-1,1,2,2,3
Chlorinated fluorinated hydrocarbons such as pentafluoropropane (HCFC225cb); 1,1,1,2,3,3-
Hexafluoropropane (HFC236ea), 1,
1,1,3,3-pentafluoropropane (HFC24
Fluorinated hydrocarbons such as 5fa).

In the present invention, the foaming agent is used in an amount of 1 to 50 parts by weight based on 100 parts by weight of the epoxy resin reaction product. If the amount is less than 1 part by weight, the foaming becomes insufficient. 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 in the production of various resin foams such as polyurethane resin foams and phenol resin foams.

A surfactant is preferable as the foam stabilizer, and a nonionic surfactant is more preferable 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 a foam stabilizer as described above include sorbitan monostearate, sorbitan monooleate, sorbitan esters such as 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 either be 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 reaction product. If it is less than 0.01 part by weight, the effect of uniformizing the size and distribution of the foam after foaming is lacking, and if it exceeds 10 parts by weight, it acts as a plasticizer and lowers the rigidity of the foam.

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, silicica fume, silica sand, pearlite, shirasu balloon, titanium oxide, carbon black, phthalocyanine and the like. These fillers and pigments can be used in a desired amount and type, if necessary, and mixed with an epoxy resin reaction product or the like using a kneader, mixing roll, Henschel mixer or the like.

The reaction product of an epoxy resin and a phosphoric acid or a mixture of phosphoric acids or the like usually reacts at normal temperature. Therefore, in the method for producing an epoxy resin foam of the present invention, the epoxy resin and the phosphoric acid or the phosphoric acid are mixed. It is preferable to mix the same mixture at room temperature to form a reactive mixture,
When the epoxy resin reaction product is a high-viscosity liquid or the like, the mixing of the epoxy resin reaction product with phosphoric acids or a mixture of phosphoric acids or the like can be performed under heating.

The foaming agent and the foam stabilizer can be mixed with these at the same time when they are mixed. However, the foaming agent and the foam stabilizer can be mixed in advance with at least one of the two. When pre-mixed, it is mixed with the epoxy resin reaction product to form a pre-mixture because of the easiness of mixing, and the pre-mixture is mixed with a component containing a mixture of phosphoric acids or phosphoric acids to obtain a reactive mixture. Preferably a mixture.

A reactive mixture containing an epoxy resin reaction product, a phosphoric acid or a mixture of phosphoric acids, a foaming agent and a foam stabilizer can initiate the reaction at room temperature, and the reaction proceeds with heat generation. Along with the vaporization of the foaming agent, it foams and reacts and cures to form an epoxy resin foam.As a device that mixes such components and discharges and injects the mixture, it is usually used for the production of polyurethane resin foam and the like. It is preferred to use a mixing device called a multi-component mixing foamer as used.

The epoxy resin foam of the present invention may be molded into a desired shape by a foaming method in which the raw materials are mixed and poured into a mold having a desired size and shape while foaming and curing. It is possible to adopt 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 with a doctor blade or the like, and the mixture is cured. .

The epoxy resin foam of 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. ,
Further, it can be used for an application as 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.

[0061]

The mixture of the reaction product of the epoxy resin and phosphoric acid or a mixture of phosphoric acids and the like rapidly reacts at room temperature to generate heat. The heat of reaction is utilized for vaporizing the foaming agent. A mixture of the resin reaction product and a mixture of phosphoric acids or phosphoric acids can be easily and quickly cured at room temperature without heating to obtain an epoxy resin foam.

In addition, since phosphoric acid reacts and is taken into the resin skeleton constituting the epoxy resin foam,
Phosphoric acid functions similarly to the reactive flame retardant, and an epoxy resin foam having high flame retardancy can be obtained.

Further, a novolak-type phenolic resin, which is a raw material of an epoxy resin reaction product, increases the degree of crosslinking of an epoxy resin, which is another raw material, so that a foam having excellent heat resistance and flame retardancy can be obtained. be able to.

[0064]

The present invention will be described in more detail with reference to the following examples. In addition, specific novolak-type phenolic resins in the examples were named novolak-type phenolic resins, novolak-type cresol resins, and the like according to the type of phenols used as raw materials.

Example 1 100 parts by weight of a bisphenol A diglycidyl ether epoxy resin having an epoxy equivalent of 180 g / eq
30 parts by weight of a solid novolak-type phenol resin having a hydroxyl equivalent of 108 g / eq was mixed, and the novolak-type phenol resin was melted at 80 ° C., and reacted at 120 ° C. for 2 hours to give an epoxy equivalent of about 1000 g / eq. eq of a viscous liquid reaction product was obtained. A product obtained by adding 0.5 parts by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer to 100 parts by weight of this reaction product was designated as X component, 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 = 100.5:
With a 20:15 discharge weight ratio, a total of 3
The mixture was fed at a flow rate of Kg / min, and the reactive mixture was discharged. 1250 g of this reactive mixture was immediately added to 500 × 5
When placed in a metal frame at room temperature of 00 × 100 mm, foaming started 20 seconds after injection, and foaming hardening was completed 2 minutes later.

Example 2 Based on 100 parts by weight of a bisphenol A diglycidyl ether epoxy resin having an epoxy equivalent of 180 g / eq.
30 parts by weight of a solid novolak-type phenol resin having a hydroxyl equivalent of 108 g / eq was mixed, and the novolak-type phenol resin was melted at 80 ° C., and reacted at 120 ° C. for 2 hours to give an epoxy equivalent of about 1000 g / eq. eq of a viscous liquid reaction product was obtained. To 100 parts by weight of this reaction product, 1 part by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer, and 1 part by weight of a foaming agent
The X-component obtained by adding 15 parts by weight of 1-dichloro-1-fluoroethane was put in a raw material tank of a multi-component mixed foaming machine. Next, a mixture of phenylphosphonic acid and monomethyl phosphate at a weight ratio of 2: 1 was used as the Y component and placed in another raw material tank. X and Y are represented by X: Y
= 116: 50, and the mixture was fed into the mixing head at a total flow rate of 3 kg / min to discharge a reactive mixture. 1250 g of this reactive mixture is immediately added to 500
When placed in a normal temperature metal frame of × 500 × 100 mm, foaming started 30 seconds after injection, and foaming hardening was completed 2 minutes and 30 seconds later.

Example 3 45 parts by weight of a solid novolak-type cresol resin having a hydroxyl equivalent of 123 g / eq were mixed with 100 parts by weight of a diglycidyl hexahydrophthalate epoxy resin having an epoxy equivalent of 140 g / eq. After melting the novolak-type cresol resin at a temperature of 2 ° C., the mixture was reacted at the same temperature for 2 hours to obtain a viscous liquid reaction product having an epoxy equivalent of about 450 g / eq. This reaction product 10
0 parts by weight, 1 part by weight of a dimethylpolysiloxane polyoxyalkylene copolymer as a foam stabilizer, methylene chloride as a foaming agent, and 1,1-dichloro-2,2,3,
X component was obtained by adding 25 parts by weight of a mixture of 3,3-pentafluoropropane at a weight ratio of 4: 1 and
It was put in the raw material tank of the multi-component mixed foaming machine. Next, P ₂ O ₅
A mixture of polyphosphoric acid and aluminum dihydrogen phosphate at a weight ratio of 76% in terms of a weight ratio of 3: 2 was used as a Y component, and was placed in another raw material tank. X: Y = 126:
With a discharge weight ratio of 35, a total of 3 kg /
min, and the reactive mixture was discharged.
Immediately, 500 × 500 ×
When placed in a 100 mm room temperature metal frame, foaming started 30 seconds after injection and foaming hardening was completed 3 minutes later.

Example 4 A solid novolak-type phenol resin having a hydroxyl equivalent of 108 g / eq was mixed with 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 melting the novolak type phenol resin at 80 ° C., the mixture was reacted at 140 ° C. for 3 hours to obtain a viscous liquid reaction product having an epoxy equivalent of about 600 g / eq. 100 parts by weight of this reaction product, 1 part by weight of a 1: 1 mixture of a dimethylpolysiloxane polyoxyalkylene copolymer as a foam stabilizer and polyethylene glycol distearate in a weight ratio of 1: 1, and a foaming agent 1,1-
What added 20 parts by weight of dichloro-1-fluoroethane was designated as X component, and the mixture was placed in a raw material tank of a multi-component mixed foaming machine. Next, a mixture of industrial 85% phosphoric acid and phenylphosphonic acid at a weight ratio of 2: 1 was used as the Y component and placed in another raw material tank. X: Y = 121:
With a discharge weight ratio of 5, a total of 3 kg / m
The reaction mixture was fed in at a flow rate of in. Immediately 500 g of 500 × 500 × 1
When placed in a metal frame at room temperature of 00 mm, foaming started 2 minutes after injection, and foaming hardening was completed 5 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
30 parts by weight of a solid novolak-type phenol resin having a hydroxyl equivalent of 108 g / eq was mixed, and the novolak-type phenol resin was melted at 80 ° C., and reacted at 120 ° C. for 2 hours to give an epoxy equivalent of about 1000 g / eq. eq of a viscous liquid reaction product was obtained. A product obtained by adding 0.5 parts by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer to 100 parts by weight of this reaction product was designated as X component, and the mixture was placed in a raw material tank of a multi-component mixed foaming machine. next,
Aromatic triamine as a curing agent was used as the Y component and placed in another raw material tank. Subsequently, 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, and Z are represented by X: Y: Z =
At a discharge weight ratio of 100.5: 20: 15, 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 5 minutes after injection, and foaming hardening was completed 8 minutes later. Was shrunk, and a foam having the dimensions of the metal frame could not be obtained.

Comparative Example 2 100 parts by weight of a bisphenol A diglycidyl ether-based epoxy resin having an epoxy equivalent of 180 g / eq
30 parts by weight of a solid novolak-type phenol resin having a hydroxyl equivalent of 108 g / eq was mixed, and the novolak-type phenol resin was melted at 80 ° C., and reacted at 120 ° C. for 2 hours to give an epoxy equivalent of about 1000 g / eq. eq of a viscous liquid reaction product was obtained. A product obtained by adding 0.5 parts by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer to 100 parts by weight of this reaction product was designated as X component, 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 = 100.5:
With a 70:20 discharge weight ratio, a total of 3
The mixture was fed at a flow rate of Kg / min, and the reactive mixture was discharged. 1250 g of this reactive mixture was immediately added to 500 × 5
The foam was cured by placing it in a metal frame of 00 × 100 mm at room temperature, but the foam was not completely cured and the foam was slightly tacky.

Comparative Example 3 80 parts by weight of a solid novolak cresol resin having a hydroxyl equivalent of 123 g / eq were mixed with 100 parts by weight of a diglycidyl hexahydrophthalate epoxy resin having an epoxy equivalent of 140 g / eq, and 120 parts by weight. After melting the novolak type cresol resin at 2 ° C., the mixture was reacted at the same temperature for 2 hours to obtain an epoxy equivalent of about 2500 g / eq.
, A highly viscous liquid reaction product was obtained. To 100 parts by weight of this reaction product, 1 part by weight of a dimethylpolysiloxane polyoxyalkylene copolymer as a foam stabilizer, and methylene chloride and 1,1-dichloro-
25 parts by weight of a mixture of 2,2,3,3,3-pentafluoropropane at a weight ratio of 4: 1 and the addition of 25 parts by weight were designated as X component, and the mixture was placed in a raw material tank of a multi-component mixing foaming machine.
Next, a mixture of 76% of polyphosphoric acid in terms of P ₂ O ₅ and aluminum dihydrogen phosphate in a weight ratio of 3: 2 was used as a Y component, and was placed in another raw material tank. X and Y are each represented by X:
The mixture was fed into the mixing head at a discharge weight ratio of Y = 126: 35 at a total flow rate of 3 kg / min to discharge a reactive mixture. 1250 g of this reactive mixture is immediately added to 50
Although placed in a 0x500x100mm room temperature metal frame,
Because the viscosity of the reaction product was too high, the reactive mixture did not flow sufficiently, and a foam having the dimensions of the metal frame could not be obtained.

Comparative Example 4 5 parts by weight of a solid novolak type phenol resin having a hydroxyl equivalent of 108 g / eq were mixed with 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 melting the novolak type phenol resin at 80 ° C., the mixture was reacted at 140 ° C. for 3 hours to obtain a viscous liquid reaction product having an epoxy equivalent of about 600 g / eq. 100 parts by weight of this reaction product, 1 part by weight of a 1: 1 mixture of a dimethylpolysiloxane polyoxyalkylene copolymer as a foam stabilizer and polyethylene glycol distearate in a weight ratio of 1: 1, and a foaming agent 1,1-
What added 20 parts by weight of dichloro-1-fluoroethane was designated as X component, and the mixture was placed in a raw material tank of a multi-component mixed foaming machine. Next, a mixture of industrial 85% phosphoric acid and phenylphosphonic acid at a weight ratio of 2: 1 was used as the Y component and placed in another raw material tank. X: Y = 121:
3, the total weight of the mixing head is 3 kg / m3.
The reaction mixture was fed in at a flow rate of in. Immediately 500 g of 500 × 500 × 1
When placed in a metal frame at room temperature of 00 mm, foaming started 3 minutes after injection. However, since the amount of heat generated by the reaction between the reaction product and phosphoric acid or phenylphosphonic acid was small, foaming was not sufficient. In addition, a foam having the same dimensions as the metal frame was not obtained, and a lump having some tackiness was obtained.

Table 1 below shows the physical properties of the foams obtained by the above Examples and Comparative Examples.

[0074]

[Table 1]

[0075]

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 of the present invention, phosphoric acid and the like are incorporated in the resin skeleton constituting the foam, and the epoxy resin and the novolak phenol resin are combined as raw materials. It is excellent in heat resistance and flame retardancy.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-47-7940 (JP, A) JP-A-63-305145 (JP, A) JP-A-9-227709 (JP, A) JP-A-9-1997 235404 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08J 9/00-9/42 C08G 59/00-59/72 C09K 21/12

Claims (8)

(57) [Claims] 1. 100 parts by weight of a liquid reaction product having an epoxy equivalent of 2000 g / eq or less, obtained by reacting an epoxy resin having two or more epoxy groups in a molecule with a novolak-type phenolic resin; An epoxy resin foam having a resin skeleton obtained by reacting 5 to 50 parts by weight of at least one phosphoric acid selected from an acid, polyphosphoric acid and phenylphosphonic acid. 2. 100 parts by weight of a liquid reaction product having an epoxy equivalent of 2000 g / eq or less obtained by reacting an epoxy resin having two or more epoxy groups in a molecule with a novolak-type phenolic resin; A mixture comprising at least one phosphoric acid selected from acids, polyphosphoric acids and phenylphosphonic acids, and at least one phosphoric acid compound selected from phosphates and phosphates having a hydroxyl group bonded to a phosphorus atom An epoxy resin foam having a resin skeleton obtained by reacting 5 to 50 parts by weight. 3. The epoxy resin foam 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. body. 4. The reaction product according to claim 1, wherein the reaction product of the epoxy resin and the novolak-type phenolic resin is obtained by reacting 100 parts by weight of the epoxy resin with 1 to 60 parts by weight of the novolak-type phenolic resin. An epoxy resin-based foam as described in Crab. 5. A method for producing an epoxy resin foam, comprising foaming and curing a mixture containing the following components A to D at the following quantitative ratios. A: A liquid reaction product having an epoxy equivalent of 2000 g / eq or less obtained by reacting an epoxy resin having two or more epoxy groups in a molecule with a novolak-type phenolic resin: 100 parts by weight B: phosphoric acid , At least one phosphoric acid selected from polyphosphoric acid and phenylphosphonic acid ... 5 to 50 parts by weight C: foaming agent ... 1 to 50 parts by weight D: foam stabilizer ... 0.01 to 10 parts by weight 6. A method for producing an epoxy resin-based foam, comprising foaming and curing a mixture containing the following components A to D at the following quantitative ratios. A: A liquid reaction product having an epoxy equivalent of 2000 g / eq or less obtained by reacting an epoxy resin having two or more epoxy groups in a molecule with a novolak-type phenolic resin: 100 parts by weight B ': phosphorus A mixture comprising at least one phosphoric acid selected from acids, polyphosphoric acids and phenylphosphonic acids, and at least one phosphoric acid compound selected from phosphates and phosphates having a hydroxyl group bonded to a phosphorus atom ... 5 to 50 parts by weight C: foaming agent ... 1 to 50 parts by weight D: foam stabilizer. ..0.01 to 10 parts by weight 7. The epoxy resin foam according to claim 5, 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. How to make the body. 8. The reaction product according to claim 5, wherein the reaction product of the epoxy resin and the novolak-type phenolic resin is obtained by reacting 100 parts by weight of the epoxy resin with 1 to 60 parts by weight of the novolak-type phenolic resin. A method for producing an epoxy resin-based foam according to the above.