JPH0931231A - Highly reactive modified phenolic resin foam and method for producing the same - Google Patents

Abstract

(57) [Summary] [Structure] (A) A modified phenolic resin obtained by polycondensing a heavy petroleum oil or pitches, a formaldehyde polymer and a phenol in the presence of an acid catalyst is used as an acid catalyst. A highly reactive modified phenolic resin-based foam, which is obtained by curing and foaming a resin composition comprising a highly reactive modified phenolic resin having a low molecular weight by reacting with phenols in the presence of (B) and an epoxy resin. (C) an amine-based curing agent and / or a curing accelerator, and (D) a foaming agent are added to the described resin composition, and curing and foaming are performed at 120 to 300 ° C.
A method for producing a highly reactive modified phenolic resin-based foam, which is post-cured at 130 to 300 ° C. if necessary. [Effect] By using a resin composition in which a novel highly reactive modified phenolic resin is blended with an epoxy resin, mechanical properties such as heat resistance, moisture resistance, dimensional stability at high temperature, and strength are excellent, and foam moldability is improved. Has characteristics that are good.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel and useful highly reactive modified phenolic resin foam and a method for producing the same. More specifically, the present invention relates to a novel highly reactive modified phenolic resin whose main component is a novel highly reactive modified phenolic resin obtained by reducing the molecular weight of a modified phenolic resin made from petroleum heavy oils or pitches with phenols. TECHNICAL FIELD The present invention relates to a modified phenolic resin foam and a method for producing the same. More specifically, in the present invention, by using a novel highly reactive modified phenolic resin as the resin raw material of the foam, the resin melt viscosity is low, the foaming moldability is excellent, and the heat resistance, moisture resistance, and size at high temperature are high. It has excellent mechanical properties such as stability and strength.

[0002]

2. Description of the Related Art Conventionally, phenol resin foams have excellent heat resistance, flame retardancy, and excellent heat insulating properties at low temperatures, and are used in various heat insulating materials, vibration damping materials, building materials, structural materials, etc. Widely used in. In order to enhance the strength characteristics of the phenol resin foam, various modified phenol resins have been developed. Particularly, the novolac type phenol resin foam uses a curing agent such as hexamethylenetetramine. Therefore, a foam having a high closed-cell property and having no problem of corrosion of a material such as a metal due to an acid can be obtained, and a demand for this kind of foam is increasing.

[0003]

DISCLOSURE OF THE INVENTION The present invention uses a resin composition containing a novel highly reactive modified phenolic resin and an epoxy resin as main resin components constituting a foam, and has excellent foam moldability and heat resistance. It is an object of the present invention to provide a foam having excellent mechanical properties such as resistance, moisture resistance, dimensional stability at high temperature, and strength.

[0004]

Means for Solving the Problems As a result of various studies on the above-mentioned problems, the present inventors have confirmed that a modified phenol resin derived from petroleum heavy oils or pitches is used as a main resin component of a foam to obtain phenols. By using a resin composition in which a novel highly reactive modified phenolic resin having a low molecular weight with epoxy resin is blended, excellent foaming moldability and heat resistance,
The inventors have found that a foam having excellent mechanical properties such as moisture resistance, dimensional stability at high temperature, and strength can be obtained, and completed the present invention.

That is, the present invention: (A) a modified phenolic resin obtained by polycondensing a heavy petroleum oil or pitches, a formaldehyde polymer and a phenol in the presence of an acid catalyst is used as an acid catalyst. Provided is a highly reactive modified phenolic resin-based foam, which is obtained by curing and foaming a resin composition comprising a highly reactive modified phenolic resin having a low molecular weight by reacting with phenols in the presence of To do. Further, the compounding ratio of the highly reactive modified phenolic resin (A) / epoxy resin (B) is 10/90 to 90/10 (parts by weight).
It is also characterized in that Also, (C) an amine-based curing agent and / or a curing accelerator, and (D) a foaming agent are added to the resin composition described above,
Curing and foaming at 0 ~ 300 ℃, 130 if necessary
Provided is a method for producing a highly reactive modified phenolic resin-based foam, which is post-cured at 300 ° C.

Hereinafter, the present invention will be described in detail. (1) Resin component for foam (i) In the present specification, petroleum heavy oil or pitches, formaldehyde polymer and phenols,
The reaction product obtained by polycondensation in the presence of an acid catalyst is referred to as a "modified phenol resin", and a modified phenol resin having a low molecular weight with a phenol used as a resin component for a foam in the present invention is referred to as "highly reacted". They are referred to as "sex-modified phenolic resins", and they are usually used as a product free from impurities through a purification process. The highly reactive modified phenolic resin (A) used in the present invention basically lowers the molecular weight of the modified phenolic resin obtained in a specific polycondensation step under a specific condition in a molecular weight reduction step with a phenol. It is manufactured by a method consisting of

The foam resin component of the present invention is characterized in that the highly reactive modified phenolic resin (A) is used as an essential component. As the resin component for a foam of the present invention, the highly reactive modified phenolic resin (A) and the epoxy resin (B) described later are blended, and the function of the highly reactive modified phenolic resin (A) is further characterized. A thermosetting resin such as various phenolic resins known as a foaming resin raw material may be blended in a small amount within a range that does not impair the above.
Of course, if necessary, an amine-based curing agent, a curing accelerator, and various additives described below may be added to the resin composition for foams in advance.

(2) Production of Modified Phenolic Resin The highly reactive modified phenolic resin (A) according to the present invention is obtained by subjecting a modified phenolic resin obtained in a specific polycondensation step to a molecular weight reduction step under specific conditions. It is manufactured by lowering the molecular weight.
The method for producing the modified phenolic resin is described in Japanese Patent Application No. 5-40.
It is desirable to carry out by the method described in No. 646,
The details are as follows. Modified phenol resin and method for producing the same The modified phenol resin raw material used in the present invention is polycondensed with petroleum heavy oils or pitches shown below, phenols and formaldehyde polymer in the presence of an acid catalyst.

(B) Petroleum-based heavy oils or pitches It is necessary to use petroleum-based heavy oils or pitches as a raw material. The petroleum heavy oils or pitches have an aromatic hydrocarbon fraction fa value and an aromatic ring hydrogen content Ha value of
It is desirable to use the one shown in the following formula.

[Equation 1] (The fa value can be determined by ¹³ C-NMR,
The a value can be determined by ¹ H-NMR. ) The aromatic hydrocarbon fraction fa value is 0.40 to 0.95,
Preferably 0.5 to 0.8, more preferably 0.55
˜0.75 and the aromatic ring hydrogen content Ha value is 20 to 80.
%, Preferably 25-60%, more preferably 25-
Desirably, it is 50%.

The heavy petroleum-based oils or pitches as raw materials are
The number of condensed rings of the aromatic hydrocarbon constituting this is not particularly limited, but it is preferably a condensed polycyclic aromatic hydrocarbon mainly having 2 to 4 rings. In the case of a condensed polycyclic aromatic hydrocarbon having five or more rings, the boiling point exceeds 450 ° C. in most cases, so that it is difficult to collect those having a narrow boiling point range and the quality is not stable. The heavy petroleum-based oils or pitches used as raw materials are
It is obtained as a distillation residual oil of crude oil, a hydrogenolysis residual oil, a catalytic cracking residual oil, a thermal decomposition residual oil of naphtha or LPG and a vacuum distillate of these residual oils, an extract by solvent extraction or a heat-treated product. From these, the fa value and H
It is preferable to select and use a suitable a value.

(B) Formaldehyde Polymer As the raw material formaldehyde polymer, there may be mentioned linear polymers such as paraformaldehyde, polyoxymethylene (particularly, oligomers) and cyclic polymers such as trioxane. The mixing ratio of heavy petroleum oils or pitches (a) and formaldehyde polymer (b) is
The number of moles of the formaldehyde polymer in terms of formaldehyde is 1 to 15, preferably 2 to 12, and more preferably 3 to 11 per 1 mole of the average number of moles calculated from the average molecular weight of heavy petroleum oils or pitches. I need to be there. If the mixing ratio is less than 1, a foam having sufficient physical properties may not be obtained, which is not preferable. On the other hand, when the mixing ratio is more than 15, the performance of the obtained foam and the yield of the modified phenol resin are almost unchanged, so it is considered useless to use more formaldehyde polymer. Further, the excess formaldehyde polymer may hinder the molecular weight reduction of the modified phenol resin in the molecular weight reduction step described later.

(C) Phenols Examples of phenols as raw materials include phenol, cresol, xylenol, resorcin, catechol, hydroquinone, bisphenol A, bisphenol F and α-.
One or more phenolic compounds selected from the group of naphthol and β-naphthol can be mentioned. The amount of phenols added is 0.3 to 5, preferably 0.5 to 3, as the number of moles of phenols per 1 mole of the average number of moles calculated from the average molecular weight of heavy petroleum oils or pitches. I need to be there.

If the amount added is less than 0.3, the reactivity of heavy petroleum oils or pitches with formaldehyde is inferior to that of phenols with formaldehyde, so that a sufficient crosslinking density is obtained. However, a foam having sufficient physical properties cannot be obtained. On the other hand, when the addition amount of phenols exceeds 5, the modifying effect due to the modification of the phenol resin tends to decrease.

It is desirable that the phenols are sequentially added by a method such as dropping. The rate of addition is from 0.05 to 5% by weight, preferably 0.1 to 2% by weight, based on the total weight of the reaction mixture. The time to start adding the phenols is not particularly limited, but the time to start adding may be a time at which the reaction between the heavy petroleum oil or pitches and formaldehyde has not substantially progressed. In practice,
From the state where the reaction rate of formaldehyde estimated from the amount of free formaldehyde remaining is substantially 0, 70%
Hereafter, it is desirable to start the sequential addition of phenols at a time point of preferably 50% or less.

(D) Acid catalyst As the acid catalyst, a Bronsted acid or a Lewis acid can be used, but a Bronsted acid is preferably used. As the Bronsted acid, toluenesulfonic acid,
Xylene sulfonic acid, hydrochloric acid, sulfuric acid, formic acid and the like can be used, but p-toluene sulfonic acid and hydrochloric acid are particularly excellent.
The amount of the acid catalyst used is 0.1 to 30% by weight, preferably 1 to 30% by weight based on the total amount of the petroleum heavy oil or pitches, the formaldehyde polymer and the phenols, which are raw materials for production.
It is 20% by weight.

(E) Reaction conditions In order to produce a modified phenol resin in the polycondensation step using the above raw materials and catalysts, for example, petroleum heavy oils or pitches and formaldehyde polymer should be in the above proportions. It is preferable that the mixture is heated and stirred in the presence of an acid catalyst, and phenols are successively added to the mixture until the above ratio is reached to polycondense these raw materials. At that time, the reaction temperature is 50 to 160 ° C, preferably 60 to 120 ° C. The reaction temperature is determined in consideration of the raw material composition, the reaction time, the properties of the resin produced, and the like. Reaction time is 0.5-10
Hours, preferably 1 to 5 hours. The reaction time is determined in consideration of the raw material composition, the reaction temperature, the addition rate of phenols, the properties of the resin to be formed, and the like. When the reaction is carried out batchwise, it can be carried out in one step, and it is preferably carried out in one step. In addition, when the continuous method is used, it is not necessary to use a device that is difficult to control, such as continuously mixing two or more kinds of reaction products, which are used in the conventional modified phenol resin, in a fixed amount, and the intermediate portion is used. A reaction vessel of a complete mixing type may be placed, and the phenols to be added may be fed into the reaction vessel in fixed amounts. Such a device is relatively inexpensive and has good operability.

In the present invention, such a polycondensation reaction can be carried out without a solvent, but in that case, it is necessary to pay attention to the uniformity of the reaction. A suitable solvent may be used to reduce the viscosity of the reaction system so that a uniform reaction may occur.
The solvent is not particularly limited, but is, for example, aromatic hydrocarbon such as benzene, toluene, xylene;
Halogenated aromatic hydrocarbons such as chlorobenzene; Nitrated aromatic hydrocarbons such as nitrobenzene; Nitrated aliphatic hydrocarbons such as nitroethane and nitropropane; Halogenated fats such as perkrene, trichlene and carbon tetrachloride Examples thereof include group hydrocarbons.

Step of Purifying Modified Phenolic Resin The highly reactive modified phenolic resin according to the present invention is prepared by lowering the molecular weight of the modified phenolic resin obtained by the polycondensation reaction in the lowering molecular weight step according to the method of the present invention. it can. However, in the modified phenol resin obtained by the polycondensation step, in addition to the target modified phenol resin, an acid catalyst, unreacted components, reaction solvent, and the like may remain, and these are low molecular weight reaction. It affects the reaction conditions and the amount of raw materials, catalysts, etc. involved in the reaction. For example, when the modified phenol resin used in the step of lowering the molecular weight contains a large amount of a formaldehyde polymer which is a crosslinking agent as an unreacted component, a modified phenol resin,
The polycondensation reaction of the formaldehyde polymer and the phenols may precede the inhibition of lowering the molecular weight.

Therefore, in order to appropriately set the reaction conditions in the low molecular weight conversion step so that the modified phenolic resin can efficiently lower the molecular weight by the reaction of the modified phenol resin and the phenols, it is necessary to use it in the low molecular weight conversion step. It is desirable that the modified phenolic resin obtained does not contain an acid catalyst or formaldehyde polymer in an amount that inhibits the molecular weight reduction reaction. That is, after the polycondensation step, it is preferable to perform the following purification steps on the modified phenol resin in any order or, if necessary, simultaneously in order to control the reaction to reduce the molecular weight of the phenols.

(I) A purification step of treating / precipitating with a specific solvent to remove solvent-soluble components including unreacted components, and (i)
i) A purification step of dissolving in a specific solvent to remove the catalyst residue and the cross-linking agent can be mentioned. That is, in the refining step (i) for removing such unreacted components, the reactivity contained in the raw material petroleum heavy oils or pitches is low, and the unreacted or insufficiently reacted. No ingredients,
And a step of removing the solvent used in the reaction. Specifically, the reaction product obtained in the polycondensation step is treated with an aliphatic hydrocarbon having 10 or less carbon atoms or an alicyclic hydrocarbon having 10 or less carbon atoms at any time after the completion of the heating reaction. In a specific solvent containing at least one compound selected from the group consisting of, the resin main component is precipitated, and the component soluble in the solvent, that is, the unreacted component and the component remaining in the low reaction and the polycondensation reaction The reaction solvent and the like are removed. Specific examples of such a hydrocarbon solvent include aliphatic or alicyclic hydrocarbons such as pentane, hexane, heptane, and cyclohexane, and n-hexane is particularly preferable.

In the purification step (ii) for removing the catalyst residue such as acid and the cross-linking agent, in order to remove the catalyst residue such as acid and the cross-linking agent remaining in the reaction mixture obtained by the polycondensation step, an acid catalyst is used. The solubility of the cross-linking agent is 0.1 or less, preferably 0.07 or less, and it is hardly soluble. However, it is performed by performing an extraction treatment using an extraction solvent that dissolves most of the modified phenolic resin. The extraction solvent is hardly soluble when the solubility of the acid catalyst and the cross-linking agent is 0.1 or less, but is not particularly limited as long as it is a solvent capable of dissolving most of the modified phenolic resin. For example, benzene, toluene, xylene, and other aromatic compounds. Group hydrocarbons are preferred, and toluene is more preferred.

In the present invention, the refining step (ii) is not limited to the conditions such as its temperature, but may be carried out under the condition that the above characteristics of the solvent are sufficiently exhibited. In the purification step (ii), the reaction product may be added to the solvent, or conversely, the solvent may be added to the reaction product. Of course, the catalyst residue such as acid and the cross-linking agent can be substantially removed only by the above extraction treatment. However, if desired, the modified phenolic resin after the purification step (ii) by the extraction treatment is usually followed by the following steps. Neutralization treatment and /
Alternatively, washing with water may be performed to further remove catalyst residues such as acids in the resin.

Particularly, when there is a possibility that a small amount of acid catalyst or the like remains in the extraction solution after the above-mentioned extraction treatment, it is preferable to perform the above-mentioned neutralization treatment. Examples of the neutralization treatment include addition of a basic substance to the modified phenol resin after the purification step (ii). Examples of the basic substance include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide, calcium hydroxide and magnesium hydroxide, alkaline earth metal hydroxides; ammonia, diethylenetriamine, triethylenetetramine, aniline, phenylenediamine, etc. Can be mentioned.

In the purification step of the present invention, such purification steps (i) and (ii) can be performed in any order. However, the modified phenolic resin after the purification step (ii) is usually in the form of a varnish dissolved in a solvent, and this varnished modified phenolic resin is used as it is or after adjusting the resin concentration by concentrating or adding an organic solvent. It can be used as a raw material in the step of lowering the molecular weight. In addition, the varnish-like modified phenol resin is collected as a powdery modified phenol resin which is put into a solvent in which the modified phenol resin is insoluble, for example, n-hexane and is re-precipitated, and is a raw material for the subsequent low molecular weight conversion step. You may use as.

(3) Highly reactive modified phenolic resin (A)
The novel highly reactive modified phenolic resin (A) of the present invention is
The method described in Japanese Patent Application No. 6-23617, for example, such a modified phenolic resin, that is, the reaction product obtained in the polycondensation step, is used as it is or after purification, and in the absence of a formaldehyde polymer and other cross-linking agents. It can be produced by lowering the molecular weight by reacting with phenols under the presence of an acid catalyst. In such a low molecular weight reaction, the modified phenolic resin is cut and dissociated by cutting and dissociating the acetal bond and / or methylene ether bond present in the molecule, and the phenols are bonded to the dissociated terminal portion. It is considered that since the phenol content of the modified phenolic resin is increased, a highly reactive modified phenolic resin (A) having a low resin melt viscosity and excellent reactivity with an epoxy resin can be obtained.

Therefore, the amount of the raw material and the acid catalyst used in the step of lowering the molecular weight, the type and combination thereof, the reaction conditions such as the reaction temperature, etc., are such that the modified phenol resin has a lower molecular weight and the reaction activity with the epoxy resin. There is no particular limitation as long as it is a range that can improve the above. However, it is important to appropriately select the reaction conditions such as the type and amount of the acid catalyst used in the molecular weight reduction step, the reaction temperature, and / or the type and amount of the reaction solvent. The phenols and acid catalysts used in the molecular weight reduction step may include the compounds exemplified in the polycondensation step.

In the step of lowering the molecular weight of the present invention, phenols react sufficiently if they are 10% by weight or more with respect to the weight of the modified phenol resin, but if too much phenol is used, a large amount of unreacted phenols is used. Remains, resulting in an increase in the cost required for the post-treatment, so the content is preferably 10 to 300% by weight. Further, the addition of phenols does not necessarily have to be sequential addition, and the entire amount may be introduced into the reaction system at the start of the reaction. The amount of the acid catalyst used is 0.1% by weight or more, preferably 0.1 to 15% by weight, more preferably 0.1 to 15% by weight, based on the weight of the modified phenolic resin.
It is desirable to use 10% by weight, and even more preferably 0.2 to 10% by weight.

In the step of lowering the molecular weight, the reaction solvent may or may not be used. The reaction solvent used is not particularly limited as long as it does not inhibit the low molecular weight reaction, for example, the solvent and acetone used in the polycondensation reaction,
Examples thereof include ketones such as methyl ethyl ketone and methyl isobutyl ketone: alcohols such as methyl alcohol, ethyl alcohol and n-butyl alcohol: ethers such as tetrahydrofuran. Such a solvent is preferably used in an amount of 0 to 300% by weight based on the modified phenolic resin. The reaction temperature is not particularly limited, but is usually 50 to 120 ° C, preferably 80 to 120 ° C. The reaction time is not particularly limited, and is, for example, 15 minutes to 3.0 hours, preferably 30 minutes to 2.0 hours.

(4) Highly reactive modified phenolic resin (A)
Post-treatment Since the highly reactive modified phenolic resin (A) may have unreacted components and catalyst residues such as acids remaining, it is purified by a method such as washing with water to remove unreacted components and acids. It is necessary to remove catalyst residues and the like. Preferably, the reaction product is diluted using a mixed solvent of toluene and alcohols such as methanol and ethanol or a mixed solvent of toluene and ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and then distilled water and / or Alternatively, washing treatment is performed with a mixed liquid of distilled water and isopropyl alcohol to remove unreacted components such as phenols and catalyst residues such as acids.

Further, the highly reactive modified phenolic resin (A) is prepared by removing the unreacted components and catalyst residues such as acids as described above, and then desolvating the extraction solvent, or the highly reactive modified phenolic resin (A). The resin is preferably precipitated by treating with a solvent in which (A) is insoluble, that is, an aliphatic or alicyclic hydrocarbon having 10 or less carbon atoms or a mixed solvent thereof.
Examples of such a hydrocarbon solvent include the solvents described in the step of purifying the modified phenolic resin, and n-hexane is particularly preferable.

(5) Highly reactive modified phenolic resin (A)
(A) The highly reactive modified phenolic resin (A) itself has the following features as compared with the conventional modified phenolic resin. -The number average molecular weight decreases, and the number average molecular weight is 300-
It has a molecular weight of 800, improves reactivity with epoxy resin, and lowers resin melt viscosity. Therefore, since the highly reactive modified phenolic resin (A) has a low resin melt viscosity and is excellent in moldability and has a high reactivity with an epoxy resin, particularly when combined with an epoxy resin, mechanical properties such as strength are improved. An excellent foam can be provided. Further, since the highly reactive modified phenolic resin (A) contains substantially no acid, it has no corrosiveness with respect to the metal part such as the structural material with which the foam contacts, and the reactivity with the epoxy resin (B). Is improved, heat resistance and dimensional stability are improved, and a raw material convenient as a foam can be provided.

(B) Blending of Epoxy Resin (B) When the highly reactive modified phenolic resin (A) of the present invention is used as a resin for foam, it is necessary to blend the epoxy resin (B). . The foam thus obtained has a small molding shrinkage, is excellent in heat resistance and moisture resistance, and can improve various physical properties and the like. In this case, it is a more preferable embodiment to incorporate a curing agent and / or a curing accelerator (C).

Examples of the epoxy resin include glycidyl ether type, glycidyl ester type, glycidyl amine type, mixed type and alicyclic type epoxy resins. More specifically, as the glycidyl ether type (phenol type), bisphenol A type epoxy resin, biphenyl type epoxy resin, bisphenol F type epoxy resin, tetrabromobisphenol A type epoxy resin, tetraphenylolethane type epoxy resin, phenol Novolac type epoxy resin, o-cresol novolac type epoxy resin and the like; glycidyl ether type (alcohol type) such as polypropylene glycol type epoxy resin, water-added bisphenol A type epoxy resin and the like; glycidyl ester type such as hexahydroanhydride phthalate Acid type epoxy resin, dimer acid type epoxy resin, etc .;

Examples of the glycidylamine type include diaminodiphenylmethane type epoxy resin, isocyanuric acid type epoxy resin, hydantoic acid type epoxy resin, and the like; mixed types include p-aminophenol type epoxy resin and p-
Examples thereof include oxybenzoic acid type epoxy resin. Of the above epoxy resins, bisphenol A type epoxy resin, glycidyl amine type epoxy resin, phenol novolac type epoxy resin, and biphenyl type epoxy resin are preferable. A combination of two or more of the above epoxy resins can also be used.

The mixing ratio of the highly reactive modified phenolic resin (A) and the epoxy resin (B) is not particularly limited, but the highly reactive modified phenolic resin (A) and the epoxy resin (B) are included.
The total of 100 parts by weight is 10/90 to 90/10
(Parts by weight) is preferable, and more preferably 20
/ 80 to 80/20 (parts by weight). Here, if the weight ratio of the highly reactive modified phenolic resin (A) is less than 10 parts by weight, the effect of improving heat resistance and moisture resistance of the obtained foam is not sufficient, and if it exceeds 90 parts by weight, the foam is Shows a tendency to become brittle.

(C) Blending of Amine Curing Agent and / or Curing Accelerator (C) A highly reactive modified phenolic resin (A) used as a resin for a foam together with an epoxy resin (B) and an amine curing agent and / or It is desirable to add a curing accelerator (C).
Various compounds can be used as the amine-based curing agent and / or the curing accelerator (C). Examples of the amine curing agent include cyclic amines, aliphatic amines, polyamides, aromatic polyamines and the like.

Specifically, for example, as cyclic amines, hexamethylenetetramine and the like; as aliphatic amines, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperazine, isophoronediamine. , Bis (4-amino-3-methylcyclohexyl) methane, menthanediamine, etc .; as the polyamides, vegetable oil fatty acids (dimer or trimer acid), aliphatic polyamine condensates, etc .; as the aromatic polyamines, m-
Phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, m-xylylenediamine and the like;

The curing accelerator is not particularly limited as long as it accelerates the curing reaction. For example, diazabicycloalkene such as 1,8-diazabicyclo (5,4,0) undecene-7 and its derivatives; triethylenediamine. , Benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl)
Tertiary amines such as phenol; 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole and other imidazoles;

Organic phosphines such as tributylphosphine, methyldiphenylphosphine and triphenylphosphine; tetra-substituted phosphonium / tetra-substituted borate such as tetraphenylphosphonium / tetraphenylborate; 2-ethyl-4-methylimidazole / tetraphenylborate , Tetraphenylboron salts such as N-methylmorpholine / tetraphenylborate, Lewis acids such as boron trifluoride-amine complex and Lewis bases such as tris (dimethylaminomethyl) phenol, benzyldimethylamine, dicyandiamide, adipic acid dihydrazide, Other examples include polymercaptan and polysulfide. Further, these curing agents and curing accelerators may be used alone or in combination of two or more.

(D) Other Additives In addition, the resin composition for a foam of the present invention may optionally contain various additives such as flame retardants, light stabilizers, antioxidants, reinforcing agents and fillers. Agents, pigments, extenders and the like can be added.

(6) Production of Foam As a method of producing a foam, basically, a resin composition comprising a highly reactive modified phenolic resin (A) and an epoxy resin (B) is added to an amine curing agent and / or Or a curing accelerator (C),
A foaming agent (D) and, if necessary, a foam stabilizer (E) and various additives added and mixed are cured and foamed at 120 to 300 ° C, and post-cured at 130 to 250 ° C as necessary. Consists of doing.

Production of Foam In the present invention, highly reactive modified phenolic resin (A)
Is a highly reactive modified phenolic resin (A) obtained by lowering the molecular weight of the modified phenolic resin, after removing unreacted components and acid catalyst, and then extracting solvent in the highly reactive modified phenolic resin (A). Is removed or treated with an aliphatic or alicyclic hydrocarbon having 10 or less carbon atoms or a mixed solvent thereof to precipitate the resin in powder form, and then various processes are applied to form a molding powder (compound). It is preferably used in the form. In the production of the foam of the present invention, for example, extrusion foaming can be used to extrude and foam into a sheet, but when a liquid composition is filled in a mold and foamed, various shapes and sizes can be obtained depending on the shape of the mold. You can choose one.

When the above liquid composition is used, the solution of the highly reactive modified phenolic resin (A) is treated with the highly reactive modified phenolic resin (A) obtained by lowering the molecular weight of the modified phenolic resin. The treated molding powder may be dissolved and / or diluted in an appropriate solvent to adjust to an appropriate viscosity. The solvent for dissolving and / or diluting the highly reactive modified phenolic resin (A) is not particularly limited as long as it can dissolve and / or dilute as many components as the soluble component of the resin constituting the binder to be used. However, it may be a single solvent or a mixed solvent.

Examples of good solvents for the highly reactive modified phenolic resin (A) include aromatic hydrocarbons such as benzene, toluene and xylene; amides such as dimethylacetamide; halogenated aromatic hydrocarbons such as chlorobenzene; Ethers such as tetrahydrofuran and dioxane; alcohols such as methanol and ethanol; glycols such as ethyl cellosolve; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone;
Esters such as ethyl acetate; chloroform, methylene chloride, perclen or a mixture thereof can be mentioned. Among them, it is preferable to use at least one organic solvent selected from aromatic hydrocarbons, amides, ketones, alcohols and halogenated aromatic hydrocarbons.

On the other hand, the good solvent for the epoxy resin (B) is appropriately selected and used from the organic solvents which have been widely used in the past. For example, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; methanol, Preference is given to alcohols such as ethanol; aromatic hydrocarbons such as toluene and xylene, or a mixture thereof.

In the method for producing a foam, the foaming conditions are such that the highly reactive modified phenolic resin (A) is crosslinked, for example, 120 to 300 ° C., preferably 150.
~ 250 ° C, 3 minutes to 15 minutes, preferably 5 minutes to 10 minutes, since these conditions are a function of temperature and time,
Specifically, an appropriate numerical value within the above range will be selected. In the production of the foam of the present invention, after foam molding,
130-300 ° C, preferably 180-250 if necessary
Post-curing at a temperature of ° C for several hours is desirable.

Blowing Agent (D) In producing the highly reactive modified phenolic resin-based foam of the present invention, a blowing agent such as a thermal decomposition type blowing agent or a liquid blowing agent can be used. The amount of these foaming agents added is not particularly limited, but is generally appropriately adjusted according to the desired density (magnification) of the foam. When to add these foaming agents,
It is not particularly limited as long as the function of the foaming agent can be sufficiently exhibited, but generally, it is mixed with an uncured highly reactive modified phenolic resin (A), and then a curing agent and / or a curing accelerator (C) is added and mixed. Good way.

(A) Pyrolysis-type foaming agent An organic-type pyrolysis-type foaming agent and / or an inorganic-type pyrolysis-type foaming agent may be used alone, or these organic-type pyrolysis-type foaming agents may be used in combination with other materials. It is a more preferable embodiment to use the organic heat-decomposition type foaming agent in combination or the inorganic heat-decomposition type foaming agent in combination. These thermal decomposition type foaming agents are generally used in an amount of 0.2 to 20 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the resin component containing the highly reactive modified phenolic resin (A) and the epoxy resin (B). Used in part ratio.

If the thermal decomposition type foaming agent (D) is less than 0.2 parts by weight, the expansion ratio is too low to obtain a satisfactory foamed product.
On the other hand, if it exceeds the weight part, the expansion ratio becomes too high and the mechanical strength is lowered. These heat-decomposable foaming agents (D) may be directly mixed with the resin component, but if they are mixed in advance with the resin component, the pot life of the highly reactive modified phenolic resin (A) of the present invention may be shortened or the long-term Slurry (suspension) in water or diluents such as alcohols or solvents if there is a risk of gradual decomposition during storage
It may be added in the form of liquid or solution.

The order of adding the thermal decomposition type foaming agent (D) and the amine-based curing agent and / or the curing accelerator (C) to the resin component is not particularly limited, but, for example, by adding them to the resin component at the same time. Alternatively, the heat-decomposable foaming agent (D) may be added after the resin component and the amine-based curing agent and / or the curing accelerator (C) are mixed in advance. Foam molding can be performed using a two-component or multi-component foaming machine that can supply a resin, a curing agent, a foaming agent, and the like.

Examples of the organic thermal decomposition type foaming agent include p-toluenesulfonyl hydrazide, p-toluenesulfonyl acetohydrazone, benzenesulfonyl hydrazide, 4,4'-oxybisbenzenesulfonyl hydrazide, azodicarbonamide and di- Examples thereof include nitrosopentamethylenetetramine and hydrazodicarbonamide, and the use of benzenesulfonylhydrazide and dinitrosopentamethylenetetramine is particularly preferable.

Examples of the inorganic thermal decomposition type foaming agent include zinc carbonate, nickel carbonate, calcium carbonate, sodium carbonate,
Examples thereof include lithium carbonate, ammonium carbonate, calcium carbonate, barium carbonate, strontium carbonate, and magnesium carbonate, with ammonium carbonate being particularly preferred.

(B) Liquid Foaming Agent The liquid foaming agent is not particularly limited as long as it is an organic liquid that has a low boiling point and a low heat of vaporization and is easy to evaporate. For example, petroleum ether, naphtha, pentane, hexane and the like. Volatile petroleum oils; low molecular weight fatty acid esters such as ethyl acetate;
Ketones such as methyl ethyl ketone and acetone; lower aliphatic monohydric alcohols such as methyl alcohol and ethyl alcohol; methylene chloride, carbon tetrachloride, trichlorofluoromethane, trichlorotrifluoroethane, dichloromethane, trichloroethane, dichloromethylene, trifluorotrichloro Examples thereof include low-boiling halogenated hydrocarbons such as methane.

The amount of the liquid foaming agent added is 5 to 40 parts by weight, preferably 10 to 30 parts by weight, based on 100 parts by weight of the resin component. When the liquid foaming agent (D) is less than 5 parts by weight, the expansion ratio is too low to obtain a satisfactory foam, and when it exceeds 40 parts by weight, the expansion ratio is too high and the mechanical strength is lowered. . The addition order of the liquid foaming agent (D) and the amine-based curing agent and / or the curing accelerator (C) to the resin component is not particularly limited. For example, the resin component is mixed with the liquid foaming agent and then the amine-based curing agent is added. The agent and / or the curing accelerator (C) may be added and mixed by stirring in a container equipped with a high-speed stirrer, or by using a three-component mixing head. Alternatively, the liquid foaming agent (D) may be added after previously mixing the resin component with the amine curing agent and / or the curing accelerator (C).

Foam Stabilizer In the production of the foam of the present invention, it is desirable to use a foam stabilizer (E) together with the foaming agent (D), if necessary. As a foam stabilizer, various polyoxyethylene alkylphenyl ethers that act as foam stabilizers, nonionic surfactants such as castor oil ethylene oxide adducts, or anionic surfactants such as metal soaps or amphoteric amphiphiles such as lecithin Examples thereof include a surfactant and a silicone type foam stabilizer, and it is particularly preferable to use a silicone type foam stabilizer.

(7) Properties of Foam The foam of the present invention has the following properties which are unique to the conventional modified phenolic resin foam. It has a low resin melt viscosity, excellent foaming moldability, and excellent mechanical properties such as heat resistance, moisture resistance, dimensional stability at high temperatures, and strength.

[0057]

The present invention will be described in more detail and specifically below by way of Examples, which do not limit the scope of the present invention. In the following, all parts are by weight unless otherwise specified. Table 1 shows the properties of the feedstock oil used as the reaction feedstock. This raw oil is
It is obtained by distilling the bottom oil obtained by fluid catalytic cracking (FCC) of vacuum gas oil.

[Table 1]

<Synthesis of highly reactive modified phenolic resin> (Production Example 1) 334 g of raw material oil shown in Table 1, 370 g of paraformaldehyde, p-toluenesulfonic acid monohydrate 1
37 g and p-xylene 678.5 g were charged into a glass reactor and heated to 95 ° C. with stirring. After holding at 95 ° C. for 1 hour, 209 g of phenol was added dropwise at a dropping rate of 1.3 g / min.
The mixture was reacted with stirring for a minute. Next, 3,300 g of the reaction mixture
Was poured into n-hexane to precipitate a reaction product, which was filtered to remove unreacted components and reaction solvent. 1,600
The precipitate was washed with g of n-hexane and then vacuum dried to obtain an acid-containing crude modified phenol resin.

This resin is dissolved in 10 times the weight of toluene (the solubility of p-toluenesulfonic acid monohydrate in toluene is 0.01 or less), and the main component is p-toluenesulfonic acid monohydrate. Insoluble matter (including unreacted paraformaldehyde) was filtered. The obtained resin toluene solution was concentrated until the resin concentration became 50% by weight to obtain a varnish-like modified phenol resin. Furthermore, a trace amount of triethylenetetramine was added to neutralize. This modified phenolic resin varnish was poured into 3.3 times by weight of n-hexane to precipitate a resin, which was then filtered. Then, it was vacuum dried to obtain 580 g of powdered acid-free modified phenol resin.

50 g of the obtained modified phenolic resin, 200 g of phenol, and 5 g of p-toluenesulfonic acid were added.
Charge to a 0 ml glass reactor, 250-350r
While stirring at a speed of pm, raise the temperature to 95 ° C and
After 90 minutes of holding reaction, a reaction product was obtained. A resin solution was prepared by dissolving the above reaction product in a toluene / methylisobutylketone mixed liquid (mixing ratio 4/1) in an amount of twice the weight of the product. The resin solution obtained is washed with distilled water / isopropanol mixed solution to remove unreacted phenols and residual acid, and then the toluene / methyl isobutyl ketone mixed solution is removed with an evaporator and further heated. Vacuum drying yielded 190 g of highly acid-free highly reactive modified phenolic resin powder.

<Production of Foam from Highly Reactive Modified Phenolic Resin> (Example 1) 40 parts by weight of highly reactive modified phenolic resin powder obtained in Production Example 1 and bisphenol A type epoxy resin [oiled shell epoxy Co., Ltd., trade name Epikote 828] 60 parts by weight is mixed and stirred at room temperature using a table kneader, and then 2-ethyl-4-methylimidazole [manufactured by Wako Pharmaceutical Co., Ltd., first grade] 0 as a curing accelerator. 6 parts by weight, 5 parts by weight of dinitrosopentamethylenetetramine as a foaming agent, a silicone-based foam stabilizer (L-5 manufactured by Nippon Unicar)
420) 1 part by weight was added and kneaded to obtain a curable resin-containing composition. The curable resin-containing composition was filled in a predetermined mold and was heat-cured and foamed at 150 ° C. for 10 minutes. Further, the obtained foam was post-cured at 200 ° C. for 3 hours.
A piece of the foam was cut out and its characteristics were measured and shown in Table 2 below.

Example 2 43 parts by weight of the highly reactive modified phenolic resin powder obtained in Production Example 1 and a phenol novolac type epoxy resin [produced by Yuka Shell Epoxy Co., Ltd.,
Trade name E 152] 57 parts by weight were mixed and stirred at room temperature using a table kneader, and then 2-ethyl-as a curing accelerator.
4-methylimidazole [Wako Pharmaceutical Co., Ltd., first grade]
0.6 parts by weight, 20 parts by weight of dichloromethane as a foaming agent, silicone-based foam stabilizer (L-542 manufactured by Nippon Unicar Co., Ltd.)
0) 4 parts by weight were added and kneaded to obtain a curable resin-containing composition. The curable resin-containing composition was filled in a predetermined mold and was heat-cured and foamed at 150 ° C. for 10 minutes. Further, the obtained foam was post-cured at 200 ° C. for 3 hours. A piece of the foam was cut out and its characteristics were measured and shown in Table 2 below.

[0063]

[Table 2]

[0064]

As described above, the foam of the present invention is
By using a resin composition in which a novel highly reactive modified phenolic resin is blended with an epoxy resin, it has excellent mechanical properties such as heat resistance, moisture resistance, dimensional stability at high temperatures, and strength, and good foam moldability. It has certain characteristics.

Claims (3)

[Claims] 1. A modified phenolic resin obtained by polycondensing (A) a petroleum heavy oil or pitches, a formaldehyde polymer and a phenol in the presence of an acid catalyst in the presence of an acid catalyst. A highly reactive modified phenolic resin-based foam, which is obtained by curing and foaming a resin composition comprising a highly reactive modified phenolic resin, which has been reduced to a low molecular weight by reacting with phenols, and (B) an epoxy resin. . 2. A highly reactive modified phenolic resin (A) / epoxy resin (B) compounding ratio of 10/90 to 90/10.
The highly reactive modified phenolic resin foam according to claim 1, which is (part by weight). 3. The resin composition according to claim 1 or 2 is added with (C) an amine-based curing agent and / or a curing accelerator and (D) a foaming agent, and cured and foamed at 120 to 300 ° C.
A method for producing a highly reactive modified phenolic resin-based foam, which comprises post-curing at 130 to 300 ° C. if necessary.