JPH1087869A - Resin foam and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin foam having high rigidity, denseness, good adhesion to other materials and heat resistance and to provide a process for producing the same. SOLUTION: A component (A) is obtained by reacting 100 pts.wt. liquid reaction product obtained by reacting an epoxy resin having at least two epoxy groups in the molecule with an acid anhydride for curing the epoxy resin and having an epoxy equivalent of 2,000g/eq or below with 5-50 pts.wt. at least one phosphorus acid selected among phosphoric acid, polyphosphoric acid and phenylphosphonic acid or a mixture (B) thereof with at least one phosphorus acid compound selected among phosphates having a hydroxyl group bonded to the phosphorus atom and phosphate esters. The production process comprises expanding and curing a mixture comprising 100 pts.wt. A, 5-50 pts.wt. B, 1-50 pts.wt. blowing agent (C), and 0.01-10 pts.wt. foam stabilizer (D).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel resin foam and a method for producing the same, and more particularly, to a highly rigid and dense resin foam having flame retardancy and foaming at room temperature. The present invention relates to a method for producing a curable resin foam.

[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.

[0003] 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 blowing agent are used, and the amount of the epoxy resin added is phenol. Resin 10
A foam having a content of 0.06 to 0.3 mol per 0 g is disclosed, and JP-A-58-82133 discloses a resol type phenol resin, an epoxy resin, a foaming agent, a catalyst, A foam material comprising a reinforcement and a filler is disclosed.

Further, in order to take advantage of the properties of an epoxy resin such as excellent adhesiveness with other materials, heat resistance, chemical resistance, dimensional stability, and mechanical strength, a foaming property using an epoxy resin as a base. A resin composition has been proposed. For example, Japanese Patent Application Laid-Open No. 1-197553 discloses that a resin composition is foamed at room temperature by using a compounded composition of an epoxy resin, an amine-based curing agent, a curing accelerator and an inorganic filler. It is stated that the body is obtained.

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, A method for producing an epoxy resin foam in which a reaction catalyst is heated to 120 ° C. to 240 ° C. and foamed is disclosed.

[0006] 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.

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 may cause a problem of peeling after construction.

The resole type phenol resin uses an organic acid such as p-toluenesulfonic acid as a curing catalyst, but 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.

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 an epoxy resin-based foam 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.

The present invention solves the above-mentioned drawbacks of the prior art, and is a resin foam having high rigidity, denseness, good adhesion to other materials, and heat resistance and flame retardancy. An object of the present invention is to provide a body and a method for producing the resin foam which can be foam-cured at room temperature without heating.

[0015]

Means for Solving the Problems To achieve the above object, the structure of a resin foam employed by the present invention is as follows: (1) an epoxy resin having two or more epoxy groups in a molecule and an epoxy resin curing epoxy resin. Liquid reaction product 100 having an epoxy equivalent of 2000 g / eq or less obtained by reaction with an anhydride.
5 parts by weight of at least one phosphoric acid selected from (2-1) phosphoric acid, polyphosphoric acid and phenylphosphonic acid, or (2-2) phosphoric acid, polyphosphoric acid and phenyl 5 to 50 parts by weight of a mixture of at least one phosphoric acid selected from phosphonic acids and at least one phosphoric acid compound selected from phosphate and phosphate having a hydroxyl group bonded to a phosphorus atom It has a resin skeleton obtained by the reaction.

Similarly, the construction of the method for producing a resin foam employed by the present invention to achieve the above object is as follows:
Wherein the mixture containing D is foamed and cured. 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 an acid anhydride for curing an epoxy resin, B: phosphoric acid, 5 to 50 parts by weight of at least one phosphoric acid selected from polyphosphoric acid and phenylphosphonic acid, or B ': at least one phosphoric acid selected from phosphoric acid, polyphosphoric acid and phenylphosphonic acid, and A mixture of at least one phosphoric acid compound selected from a phosphate having a hydroxyl group bonded to a phosphorus atom and a phosphate ester 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

[0017]

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 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.

The epoxy resin in the present invention is preferably a compound having a glycidyl group as an epoxy group, and particularly preferably a glycidyl ether epoxy resin, but is not limited thereto. For example, a cycloaliphatic epoxy resin And glycidyl ester-based epoxy resins, heterocyclic aliphatic epoxy resins, and the like. The epoxy resin may be in the form of an oligomer. Further, one of these epoxy resins may be selected, or two or more thereof may be used in combination.

The above-mentioned epoxy resin is preferably a liquid at normal temperature because it is easily mixed with an acid anhydride for curing an epoxy resin.
Glycidyl ether epoxy resins such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, resorcin diglycidyl ether, phenol novolak polyglycidyl ether, cresol novolac polyglycidyl ether; glycidyl such as hexahydrophthalic acid glycidyl ester and dimer acid glycidyl ester Ester-based epoxy resins; linear aliphatic epoxy resins, cycloaliphatic epoxy resins, and the like.

The acid anhydride for curing an epoxy resin in the present invention is a compound in which a carboxyl group of a carboxylic acid having 2 to 4 carboxyl groups in a molecule is converted into a cyclic acid anhydride group through a dehydration reaction. Which is generally used as a curing agent for epoxy resins.

As the acid anhydride, one having one acid anhydride group obtained from a carboxylic acid having two carboxyl groups in the molecule is referred to as a monofunctional acid anhydride, and four acids in the molecule are used. Those having two acid anhydride groups obtained from a carboxylic acid having a carboxyl group are referred to as difunctional acid anhydrides (hereinafter similarly named according to the number of acid anhydride groups), and 3 in the molecule. One having an acid anhydride group and one having a carboxyl group obtained from a carboxylic acid having one carboxyl group is referred to as a free acid anhydride. Any of these may be used, but does not include an acid anhydride obtained by dehydration-condensation of two carboxylic acid molecules.

Of course, one of the above-mentioned epoxy resin curing acid anhydrides may be selected and used.
Two or more types may be used in combination.

Examples of the acid anhydride for curing the epoxy resin include maleic anhydride, dodecyl succinic anhydride,
Aliphatic monofunctional acid anhydrides such as dichlorosuccinic anhydride;
Cycloaliphatic monofunctional acid anhydrides such as tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, chlorendic anhydride; methylcyclohexenetetracarboxylic anhydride, etc. Cycloaliphatic difunctional acid anhydrides; aromatic monofunctional acid anhydrides such as phthalic anhydride; aromatic difunctional acid anhydrides such as pyromellitic anhydride, benzophenonetetracarboxylic acid anhydride; And aromatic free acid anhydrides such as trimellitic anhydride.

In consideration of the heat resistance and flame retardancy of the foam after foaming and curing, the acid anhydride for curing the epoxy resin may be a monofunctional acid anhydride belonging to a cycloaliphatic or aromatic group.
It is preferred to use a difunctional anhydride or a free acid anhydride.

On the other hand, a reaction product obtained by the reaction between the epoxy resin and the acid anhydride for curing the epoxy resin (hereinafter, sometimes referred to as an epoxy resin reaction product) further reacts with phosphoric acids and the like described later. It is necessary to have an epoxy group, so in the present invention, as the epoxy resin reaction product,
The epoxy equivalent of 2000 g / eq or less 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 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 the liquid is a high liquid, any liquid that has a relatively low viscosity under heating may be used.

The ratio of the reaction between the epoxy resin and the acid anhydride for curing the epoxy resin to obtain the above-mentioned epoxy resin reaction product is based on 100 parts by weight of the epoxy resin and the acid anhydride for curing the epoxy resin. When the ratio of the acid anhydride for curing the epoxy resin to 100 parts by weight of the epoxy resin is less than 5 parts by weight, the flame retardancy of the obtained resin foam tends to be poor, Conversely, when the proportion of the acid anhydride for curing the epoxy resin exceeds 40 parts by weight, the amount of the epoxy group in the produced epoxy resin reaction product decreases, and the epoxy group for reacting with phosphoric acids and the like described below decreases. , Epoxy equivalent 2000g / e
q or less.

Further, when the proportion of the acid anhydride for curing the epoxy resin exceeds 40 parts by weight, the epoxy resin reaction product when gelling or otherwise becoming too high in viscosity to form a foam is obtained. , The moldability for molding into a predetermined shape is deteriorated, and a foam having a desired size and density may not be obtained. That is, in view of the flame retardancy of the foam, the reactivity with phosphoric acids, etc., the ease of controlling the viscosity of the epoxy resin reaction product, and the like, the more preferable ratio of the two is 100 parts by weight of the epoxy resin. It is 10 to 25 parts by weight of an acid anhydride for curing.

As a method for obtaining the above-mentioned epoxy resin reaction product, an epoxy resin and an acid anhydride for curing an epoxy resin are mixed and then heated, and in the case of a solid acid anhydride for curing an epoxy resin, the mixture is melted and reacted. Is preferred. The reaction temperature is preferably from 120 to 250 ° C. 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. Considering the fluidity of the reactive mixture when producing a foam, 120 to 18
It is preferred to react at a relatively low temperature of 0 ° C. to obtain a lower viscosity epoxy resin reaction product.

When the epoxy resin is reacted with the acid anhydride for curing the epoxy 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 acid anhydride for curing the epoxy resin to the epoxy resin, the reaction temperature and the reaction time, so that the epoxy equivalent is 2000 g / eq or less. Then, those conditions may be appropriately set.

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, 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 acid, at least one kind of phosphoric acid, polyphosphoric acid and phenylphosphonic acid may be used, but two or more kinds can also 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 reaction product of the epoxy resin and to be taken into the molecular skeleton of the reaction product. Therefore, the amount of the phosphoric acid is controlled to an appropriate amount. This makes it possible to prevent phosphoric acids from remaining as free acids in the obtained foam. Therefore, by controlling in such a manner, even when the 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 required. do not do.

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 being mixed to form a foam. 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 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 of a phosphate and a phosphoric acid ester may be used, but two or more of them may be used.

Examples of the phosphate in the above phosphoric acid compound include ammonium dihydrogen phosphate, diammonium hydrogen phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, and dihydrogen phosphate. Potassium, calcium dihydrogen phosphate, calcium monohydrogen phosphate, aluminum dihydrogen phosphate, dialuminum hydrogen phosphate, and the like, and phosphate esters such as monomethyl phosphate, dimethyl phosphate, monoethyl phosphate, diethyl phosphate, propyl Examples include phosphate, isopropyl phosphate, butyl phosphate, lauryl phosphate, stearyl phosphate, 2-ethylhexyl phosphate, isodecyl 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 reaction product. The reaction heat generated by the reaction with the material is small, and the foaming (vaporization) of the foaming agent becomes insufficient, and it becomes difficult to obtain a foam having a desired expansion ratio. If the amount used exceeds 50 parts by weight, the phosphoric acids often become excessive and the proportion of free acids remaining in the foam increases, and in this case, the foaming state of the foam deteriorates At the same time, when the foam comes into contact with metal or wood, the risk of corrosion and discoloration thereof 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, production conditions, and the like.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 in combination, the amount of a mixture of the above-mentioned phosphoric acid and phosphoric acid (hereinafter, may be simply referred to as a mixture of phosphoric acid and the like) is 100 parts by weight of the epoxy resin reaction product. Is preferably 5 to 50 wt.
In the same manner as described above, it can be selected depending on the use of the foam, the production method, the production conditions, and the like. For example, it can be appropriately adjusted so as to have an appropriate calorific value or to have an appropriate foam hardening 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.

In the method for producing a resin foam of the present invention, a resin foam is produced using a foaming agent. As the foaming agent, known foams such as halogenated hydrocarbons and hydrocarbons are used. Among them, among them, the boiling point is 0 to 100
Halogenated hydrocarbons at 0 ° C are preferred, and halogenated hydrocarbons which are liquid at room temperature are particularly preferred. These blowing agents are
They can be used alone or as a mixture of two or more.

Examples of the halogenated hydrocarbons described above include chlorinated hydrocarbons such as methylene chloride and trichloroethylene; 2,2-dichloro-1,1,1-trifluoroethane (HCFC123), 1,1-dichloro -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).

The above-mentioned 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 it exceeds the portion, the number of open cells increases, the closed cell ratio decreases, and the rigidity and heat insulation of the foam decrease. Furthermore, since the expansion ratio or density of the foam changes due to the increase or decrease in the amount of the foaming agent used, the amount of the foaming agent can be adjusted so that the foam density required according to the use of the foam or the like is obtained. preferable.

In the method for producing a resin foam of the present invention, the foam stabilizer is added in an amount of 0.1 to 100 parts by weight of the epoxy resin reaction product.
The foam stabilizer is used in an amount of from 01 to 10 parts by weight. As the foam stabilizer, foam stabilizers used for producing various resin foams such as polyurethane resin foam and phenol resin foam can be used.

The foam stabilizer is preferably a surfactant, and the surfactant is more preferably a nonionic 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 foam stabilizer include sorbitan esters such as sorbitan monostearate, sorbitan monooleate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan monooleate; Polyethylene glycol esters such as glycol monostearate, polyethylene glycol monooleate, polyethylene glycol distearate, and polyethylene glycol dioleate; polyoxyethylene alkyl ethers other than the above; polyoxyethylene alkyl esters; polyoxyethylene alkyl phenyl ether And polyoxyethylene alkylphenyl esters and dimethylpolysiloxane polyoxyalkylene copolymers. Can.

If the amount of the foam stabilizer used is less than 0.01 part by weight based on 100 parts by weight of the epoxy resin reaction product, the effect of uniformizing the size and distribution of bubbles after foaming is lacking. If it exceeds 10 parts by weight, it acts as a plasticizer and reduces the rigidity of the foam. A more preferred amount of the foam stabilizer is 0.5 to 5 parts by weight based on 100 parts by weight of the epoxy resin reaction product.

In the method for producing a resin foam of the present invention, a filler or a pigment may be used for the purpose of adjusting the fluidity at the time of foaming hardening or for economical effects. And pigments, for example, calcium carbonate, talc, kaolin, bentonite, mica, sericite, zeolite,
Silica, silica fume, silica sand, perlite, shirasu balloon, titanium oxide, carbon black, phthalocyanine and the like can be mentioned. These fillers and pigments can be used in a desired type and amount, if necessary, by being mixed with an epoxy resin reaction product or the like using a kneader, a mixing roll, a Henschel mixer, or the like.

The reaction product of the epoxy resin and phosphoric acid or a mixture of phosphoric acids or the like usually reacts at room temperature. Therefore, in the production method of the resin foam of the present invention, the reaction product of the epoxy resin and the phosphoric acid or phosphoric acid are used. It is preferable to mix the mixture with an acid at room temperature to form a reactive mixture. However, when the epoxy resin reaction product is a highly viscous liquid, the epoxy resin reaction product is mixed with a phosphoric acid or phosphoric acid. Mixing with the mixture can also be carried out under warming.

A foaming agent and a foam stabilizer can be mixed with the epoxy resin reaction product and a mixture of phosphoric acids or phosphoric acids at the same time when these are mixed. The foam stabilizer can be mixed in advance.If the foam stabilizer is mixed in advance, it is mixed with a component containing an epoxy resin reaction product to form a premix, because of the ease of mixing. Alternatively, it is preferable to form a reactive mixture by mixing with a component including a mixture such as phosphoric acids.

An epoxy resin reaction product and a reactive mixture containing phosphoric acid or a mixture of phosphoric acids and the like, a foaming agent and a foam stabilizer can initiate the reaction at room temperature, and the reaction is generated while generating heat. As it progresses, it is foamed by the vaporization of the foaming agent and foams and reacts and hardens to form a resin foam.A device that mixes such components and discharges and injects it as a mixture is used for producing polyurethane resin foam and the like. It is preferred to use a mixing device, such as a so-called multi-component mixing foamer.

The method of molding the resin foam of the present invention into a desired shape includes a foaming and curing method in which the raw material components are mixed and poured into a mold of a desired size and shape to foam and harden. A slab foaming method or the like may be employed in which the raw material components are mixed and flowed, 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.

The resin foam of the present invention can be used for the same applications as conventional resin foams. For example, a foam obtained by a slab foaming method is cut out to have a desired shape and a heat insulating material also serving as a mold. It can be used for applications such as plate-like heat insulators used in buildings such as houses, such as underfloor heat insulators, and foamed between the inner and outer walls of a refrigerated warehouse by the injection foaming method. It can be used for applications such as Furthermore,
A composite material such as synthetic wood can also be obtained by impregnating a mixture of the above-mentioned components into a reinforcing fiber such as a glass fiber and foaming and hardening the mixture.

[0059]

The mixture of the epoxy resin reaction product and phosphoric acid or a mixture of phosphoric acids and the like reacts rapidly at room temperature to generate heat. By utilizing this reaction heat for vaporizing the foaming agent, Without heating the mixture,
It can be easily and quickly cured at room temperature to form a resin foam.

Further, since the phosphoric acid or the mixture of phosphoric acid reacts and is taken into the resin skeleton constituting the resin foam, the phosphoric acid or the mixture of phosphoric acid functions similarly to the reactive flame retardant. Since it is possible to obtain a highly flame-retardant resin foam, and at the same time the acid anhydride for curing the epoxy resin, which is the raw material of the epoxy resin reaction product, increases the degree of crosslinking of the epoxy resin, which is the other raw material. Thus, a resin foam having excellent heat resistance and flame retardancy can be obtained.

[0061]

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

Example 1 Based on 100 parts by weight of a bisphenol A diglycidyl ether epoxy resin having an epoxy equivalent of 180 g / eq.
After mixing 25 parts by weight of phthalic anhydride,
The reaction was carried out for a time to obtain a viscous and liquid epoxy resin reaction product having an epoxy equivalent of 600 g / eq. To 100 parts by weight of this reaction product, 0.5 parts by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer and 1,1-dichloro-1-fluoroethane 15 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, 85% phosphoric acid for industrial use as phosphoric acids was used as the Y component and put in another raw material tank.
The components X and Y were fed into the mixing head at a discharge weight ratio of X: Y = 115.5: 20 at a total flow rate of 3 kg / min to discharge the mixture. When 1250 g of this mixture was immediately placed in a 500 × 500 × 100 mm room temperature metal frame, foaming started 15 seconds after injection, and foaming hardening was completed 2 minutes later.

Example 2 100 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 were mixed with 15 parts of hexahydrophthalic anhydride.
After mixing by weight, the mixture was reacted at 150 ° C. for 2 hours,
A viscous, liquid epoxy resin reaction product having an epoxy equivalent of about 600 g / eq was obtained. To 100 parts by weight of this reaction product, 1 part by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer, and 1,1 as a foaming agent
X-component obtained by adding 20 parts by weight of dichloro-2,2,3,3,3-pentafluoropropane was placed in a raw material tank of a multi-component mixed foaming machine. Next, a mixture of industrial 85% phosphoric acid as phosphoric acids and monoethyl phosphate at a weight ratio of 3: 1 was used as the Y component, and was placed in another raw material tank. X: Y = 121: 25 for each component of X and Y
3Kg / mi to the mixing head
The mixture was fed at a flow rate of n and the mixture was discharged. This mixture 12
When 50 g was immediately placed in a 500 × 500 × 100 mm room temperature metal frame, foaming started 30 seconds after injection,
After 3 minutes the foam hardening was complete.

Comparative Example 1 100 parts by weight of a bisphenol A diglycidyl ether epoxy resin having an epoxy equivalent of 180 g / eq
After mixing 45 parts by weight of phthalic anhydride,
The reaction was carried out for a time to obtain a viscous and liquid epoxy resin reaction product having an epoxy equivalent of about 2500 g / eq. To 100 parts by weight of this reaction product, 0.5 parts by weight of polyoxyethylene sorbitan monostearate as a foam stabilizer and 15 parts by weight of 1,1-dichloro-1-fluoroethane as a foaming agent are added. As the X component, and placed in a raw material tank of a multi-component mixed foaming machine. Next, 85% phosphoric acid for industrial use as phosphoric acids was used as the Y component and put in another raw material tank. The X and Y components were added to the mixing head at a discharge weight ratio of X: Y = 115.5: 20 to a total of 3 kg / min.
And the mixture was discharged. This mixture 125
When 0 g was immediately placed in a 500 × 500 × 100 mm room temperature metal frame, foaming started 1 minute after injection, and foam hardening was completed 5 minutes later. However, the resulting foam is
It had a large cavity inside and was easy to buckle.

Comparative Example 2 Based on 100 parts by weight of a bisphenol A diglycidyl ether epoxy resin having an epoxy equivalent of 180 g / eq.
After mixing 20 parts by weight of diethylenetriamine,
And the epoxy equivalent is about 750 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 15 parts by weight of 1,1-dichloro-1-fluoroethane as a foaming agent was used as the 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 components X and Y were fed into the mixing head at a discharge weight ratio of X: Y = 116: 20 at a total flow rate of 3 kg / min to discharge the mixture. 1250 g of this mixture is immediately
Although placed in a 500 × 100 mm room temperature metal frame, the decomposition product of the reaction product of the epoxy resin and diethylenetriamine occurred during foaming hardening, and a foam was not obtained. It was found that, in the case of the reaction product of the above, unlike the case of the acid anhydride, a foam could not be obtained.

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

[Table 1]

[0067]

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

In the resin foam of the present invention, phosphoric acid or a mixture of phosphoric acids is incorporated in the resin skeleton constituting the foam, and an epoxy resin and an acid anhydride for curing the epoxy resin are used as raw materials. Excellent heat resistance and flame retardancy by combining

Claims (10)

[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 an acid anhydride for curing an epoxy resin; A resin foam having a resin skeleton obtained by reacting 5 to 50 parts by weight of at least one phosphoric acid selected from phosphoric 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 an acid anhydride for curing an epoxy resin; , Phosphoric acid, polyphosphoric acid and phenylphosphonic acid, at least one phosphoric acid selected from the group consisting of at least one phosphoric acid compound selected from phosphate and phosphate having a hydroxyl group bonded to a phosphorus atom. A resin foam having a resin skeleton obtained by reacting 5 to 50 parts by weight of a mixture. 3. The resin foam according to claim 1, wherein the epoxy resin is a glycidyl ether-based epoxy resin. 4. The acid anhydride according to claim 1, wherein the epoxy resin curing acid anhydride is a monofunctional acid anhydride, a difunctional acid anhydride or a free acid anhydride belonging to a cycloaliphatic or aromatic group. The resin foam according to any one of the above. 5. The reaction product of an epoxy resin and an acid anhydride for curing an epoxy resin is a reaction product of 100 parts by weight of an epoxy resin and 5 to 40 parts by weight of an acid anhydride for curing an epoxy resin. 5. The resin foam according to any one of items 1 to 4. 6. A method for producing a resin foam, comprising foaming and curing a mixture containing the following A to D. 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 an acid anhydride for curing an epoxy resin, 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 7. A method for producing a resin foam, which comprises foaming and curing a mixture containing the following A to D. 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 an acid anhydride for curing an epoxy resin, B ': phosphoric acid A mixture of at least one phosphoric acid selected from the group consisting of 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. 50 parts by weight C: foaming agent 1 to 50 parts by weight D: foam stabilizer 0.01 to 10 parts by weight 8. The method for producing a resin foam according to claim 6, wherein the epoxy resin is a glycidyl ether epoxy resin. 9. The epoxy resin according to claim 6, wherein the acid anhydride for curing the epoxy resin is a monofunctional acid anhydride, a difunctional acid anhydride or a free acid anhydride belonging to a cycloaliphatic or aromatic group. A method for producing a resin foam according to any one of the above. 10. The reaction product of an epoxy resin and an acid anhydride for curing an epoxy resin is obtained by a reaction between 100 parts by weight of an epoxy resin and 5 to 40 parts by weight of an acid anhydride for curing an epoxy resin. 10. The method for producing a resin foam according to any one of claims 1 to 9.