JPH0610235B2 - Micro-spherical modified resole resin particles and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to fine spherical modified resol resin particles excellent in thermosetting property, water resistance, alkali resistance, arc resistance, heat resistance and storage stability, and their production. It is about law.

<Prior art><Problems to be solved by the invention> Phenolic resins are largely classified into resole resins that react phenols and aldehydes in the presence of a basic catalyst, and novolac resins that react in the presence of an acidic catalyst. Be separated. Since the resole resin contains many methylol groups in its molecule, it can be cured by heating without using a curing agent, and is suitable for melt molding.

However, since the resole resin has extremely high reactivity, there is a problem that it is difficult to store it in a powder or granular form as it is, and it has been desired to produce a stable solid resole resin suitable for melt molding.

Therefore, various methods for producing a solid resol resin which are easy to handle and have good storage stability have been proposed. For example, Japanese Patent Publication Sho 5
JP-A-3-42077 discloses that a condensate obtained by reacting a phenol and formaldehyde with a basic catalyst in the presence of an aliphatic amine such as ethylenediamine is added to a hydrophilic organic material such as gelatin, casein and polyvinyl alcohol. A method for producing a granular or powdery resol resin by adding a compound and reacting the same is also disclosed in JP-A-52 / 52
No. 1418993 discloses a granular resol resin obtained by emulsion polymerization of phenol, formaldehyde and a basic catalyst such as ammonia in the presence of a protective colloid such as gum arabic, Gatch gum, hydroxyalkyl rubber or partially hydrolyzed polyvinyl alcohol. A method of manufacturing is disclosed.

However, all of these methods use a hydrophilic organic polymer compound as an emulsion stabilizer, and since the resole resin obtained by these methods contains a hydrophilic organic polymer compound, it is still fused during storage (S
intering).

On the other hand, although phenolic resins are used for various purposes by taking advantage of heat resistance and the like, they have problems in water resistance, alkali resistance, and arc resistance, and improvements thereof have been desired.
In addition, higher heat resistance has been desired for application to more severe applications.

In order to meet this demand, it is known that modification with a nitrogen-containing compound such as melamine, urea, thiourea, and aniline is effective, and a nitrogen-containing compound-modified resol resin is known.

However, the nitrogen-containing compound-modified resol resin also has extremely high reactivity like the resol resin, is usually produced as a water or methanol solution, and is stored as a solution as it is, as a granular or powdery stable solid substance. It was difficult to remove from the solution.

In order to make up for this drawback, for example, in Japanese Examined Patent Publication (Kokoku) No. 32-993, a mixture of phenol, formalin and urea is reacted in the presence of an alkaline catalyst to give a modified resole resin, which is then switched to an acidic catalyst for further condensation. A method of making a solid thermosetting resol novolak resin is disclosed.

However, in this method, it is necessary to change from alkaline to acidic during the reaction, and it is difficult to control the reaction such as the timing. Further, there is a drawback that the resin must be crushed to obtain the granular material.

Further, in JP-A-58-17114, fine granular solid thermosetting is carried out by reacting phenols, a nitrogen-containing compound and a large excess of formaldehyde (8 to 10 times mol relative to phenols) under an acidic catalyst. Disclosed is a method of producing a volatile phenolic resin. However, the phenolic resin obtained by this method is not a so-called resol resin and has poor flow characteristics and a slow curing rate.
Further, this method has a problem that a large excess of formaldehyde is required.

<Means for Solving Problems> The present invention solves the conventional problems as described above.

That is, a first object of the present invention is to provide fine spherical modified resol resin particles excellent in water resistance, alkali resistance, arc resistance and heat resistance, and a method for producing the same.

Another object of the present invention is to provide fine spherical modified resol resin particles excellent in storage stability and thermosetting property and a method for producing the same.

As a result of earnest research to solve such problems, the present inventors have achieved the above object by producing a resole resin obtained by copolymerizing a nitrogen-containing compound using a specific inorganic salt as an emulsion stabilizer. Find what you can reach,
The present invention has been reached.

That is, the present invention, a part or all of the surface is coated with a substantially water-insoluble inorganic salt containing a fluorine atom, relative to the phenols constituting the resole resin 0.
Contains 2 to 3.5% by weight of the above inorganic salts and has a particle size of 500
Microsphere-modified resole resin particles composed of a resole resin obtained by copolymerizing a nitrogen-containing compound having a diameter of at most μm, and phenols, aldehydes and nitrogen-containing compounds in the presence of a basic catalyst in an aqueous medium. In the reaction, the reaction system is allowed to react in the presence of a substantially water-insoluble inorganic salt containing 0.2 to 3.5% by weight of a fluorine atom with respect to phenols, and particles having a particle size of 500 μm or less are obtained. It is a method for producing fine spherical modified resol resin particles composed of a resole resin obtained by copolymerizing a nitrogen-containing compound, which is characterized by being formed.

The present invention will be described in more detail below.

FIG. 1 is an example of an electron micrograph of fine spherical modified resol resin particles made of a resole resin obtained by copolymerizing the nitrogen-containing compound of the present invention. It is observed that the modified resol resin particles of the present invention are spherical particles independent of each other, that the particle size is 500 μm or less, or that the surface of the particles is covered with an inorganic salt containing a fluorine atom. .

The substantially water-insoluble inorganic salt containing a fluorine atom referred to in the present invention has a solubility in water at 25 ° C. of 0.2.
It refers to inorganic salts containing fluorine atoms of g / g or less, and examples thereof include calcium fluoride, magnesium fluoride, and strontium fluoride.

The microspherical modified resol resin particles according to the present invention are obtained by coating the surface of the resin with the above-mentioned substantially water-insoluble inorganic salt containing a fluorine atom, and the embodiments thereof will be described below.

The coating on the particle surface of the substantially insoluble inorganic salt containing a fluorine atom, when reacting phenols, aldehydes and nitrogen-containing compounds in an aqueous medium in the presence of a basic catalyst as described below, It is formed by coexisting a substantially water-insoluble inorganic salt containing a fluorine atom, and a desired coating can be obtained by appropriately changing the addition amount of the substantially water-insoluble inorganic salt containing a fluorine atom. It can be quantity.

Unlike the conventional powdery or granular particles, the modified resol resin particles of the present invention have a fine spherical shape, and no fusion of particles is observed. Thus, the modified resole resin particles of the present invention exhibit a fine spherical shape, and no fusion is observed because the coating of the substantially water-insoluble inorganic salt containing a fluorine atom formed in the production method described later. It is presumed that it prevents fusion of particles during resin production and storage.

Thus, the modified resol resin particles of the present invention having the above-mentioned constitution have excellent storage stability for one year because the surface thereof is coated with a substantially water-insoluble inorganic salt containing a fluorine atom. As described above, the particles can be stored without causing fusion of particles, and since the particles are fine spherical particles having a particle size of 500 μm or less, they can be easily handled during use such as molding.

The nitrogen-containing compound to be copolymerized in the present invention is at least one nitrogen-containing compound selected from the group consisting of an aromatic amine compound having at least one active hydrogen bonded to a nitrogen atom, an amide compound and a thioamide compound,
Urea, thiourea, melamine, guanidine, guanamine,
Dicyandiamide and cyanuric acid, or derivatives thereof are preferable, and one or more can be used.

Next, a method for producing the fine spherical modified resole resin particles of the present invention will be described.

First, the method of the present invention comprises reacting phenols, aldehydes and nitrogen-containing compounds in an aqueous medium in the presence of a basic catalyst and a substantially water-insoluble inorganic salt containing a fluorine atom. The phenols used in (1) are phenol and phenol derivatives. Examples of the phenol derivative include m-alkylphenol, o-alkylphenol and p-alkylphenol substituted with an alkyl group having 1 to 9 carbon atoms, specifically m -Cresol, p-ter-butylphenol, o-propylphenol, resorcinol, bisphenol A, and halogenated phenol derivatives in which some or all of the hydrogen atoms of these benzene nuclei or alkyl groups are substituted with chlorine or bromine. , Or one or more of these are used. The phenols are not limited to these, and any other compound containing a phenolic hydroxyl group can be used. The aldehydes used in the present invention include, for example, formaldehyde and furfural in any form of formalin or paraformaldehyde, and the molar ratio of aldehydes to phenols is 1 to 2, particularly 1.1 to 1.4.

Preferred nitrogen-containing compounds used in the present invention include:
As mentioned above, aromatic amine compounds, amide compounds, thioamide compounds, urea, thiourea, melamine, guanidine, guanamine, dicyandiamide, cyanuric acid and the like are preferable, and the preferable amount thereof is 2-200 wt% with respect to phenols, especially 3 ~ 100wt%, and further 5 ~
It is 50 wt%.

If the amount of the nitrogen-containing compound used is less than 2 wt%, its effect is small, and if it exceeds 200 wt%, it tends to be difficult to form fine spherical particles during emulsion polymerization.

Further, as the basic catalyst used in the method of the present invention, a basic catalyst used in ordinary resol resin production can be used. For example, in addition to aqueous ammonia, fats such as hexamethylenetetramine and dimethylamine, diethylenetriamine and polyethyleneimine can be used. Group amines and the like can be mentioned. The molar ratio of these basic catalysts to phenols is 0.02-0.2.
Is preferred.

As the substantially water-insoluble inorganic salt containing a fluorine atom used in the present invention, as described above, calcium fluoride, magnesium fluoride, strontium fluoride or the like is preferable, and the amount thereof is 0.5 relative to phenols. ~ 3.5wt%
Is. In addition, in order to add the substantially water-insoluble inorganic salt containing a fluorine atom, the substantially water-insoluble inorganic salt containing a fluorine atom may be directly added as described above, or during the reaction. You may add 2 or more types of water-soluble inorganic salts which produce the substantially water-insoluble inorganic salt containing a fluorine atom. That is, for example, in place of the fluorine compound of calcium, magnesium, strontium, at least one selected from the group consisting of sodium fluoride, potassium fluoride, and ammonium fluoride in one of the water-soluble inorganic salts and calcium, magnesium in the other. , Strontium chloride, at least one selected from the group consisting of sulfates, nitrates,
It is also possible to generate a fluorine compound of calcium, magnesium or strontium during the reaction.

The reaction of the method of the present invention is carried out in an aqueous medium. In this case, the charged amount of water is, for example, a solid content concentration of the resin of 30.
It is desirable to set the content to ˜70 wt%, preferably 50 to 60 wt%.

The modified resole resin particles of the present invention are produced, for example, as follows.

Phenols, aldehydes, nitrogen-containing compounds, basic catalysts and inorganic salts containing fluorine atoms in an aqueous medium with stirring are heated at a rate of 0.5 to 1.5 ° C / min, preferably 0.8 to 1.
The temperature was gradually raised at 2 ° C / min, and the reaction temperature was 70 to 9
The reaction is carried out at 0 ° C., preferably 83 to 87 ° C. for 60 to 150 minutes, preferably 80 to 110 minutes. After the reaction in this way, the reaction product is cooled to 40 ° C. or lower to obtain a stable solid modified resol aqueous emulsion.

Next, this aqueous emulsion is separated into solid and liquid by a conventional method such as filtration or centrifugation, and then washed and dried,
The solid fine spherical modified resol resin particles of the present invention having a particle size of 500 μm or less, the surface of which is coated with a substantially insoluble inorganic salt containing a fluorine atom, can be obtained.

The method of the present invention can be carried out by either a continuous method or a batch method, but is usually carried out by the batch method.

As described above, the modified resol resin particles obtained by the method of the present invention are fine spherical solid particles having a smooth and non-fusing property, and as described above, have excellent stability and good flow characteristics, and have good moldability. Are better. Further, the fine spherical modified resol resin particles obtained by the method of the present invention have good reactivity and fast gelation rate, can be molded in a short time, and have excellent performance and quality of molded products. Furthermore, the fine spherical modified resol resin particles obtained by the method of the present invention have a particle size of 500 μm or less, and most of them are 100 μm or less, and the particle size distribution is extremely sharp as compared with the granular resole resin produced by the conventional method. From this, it is affirmed that the emulsion stabilization method of the present invention is an extremely excellent method.

In the method of the present invention, when reacting a phenol, an aldehyde and a nitrogen-containing compound in an aqueous medium in the presence of a basic catalyst and a substantially water-insoluble inorganic salt containing a fluorine atom, if necessary, A flame retardant such as phosphorus, an inorganic filler such as talc, or various additives such as a foaming agent can coexist.

The fine spherical modified resol resin particles of the present invention are usually used as a solid modified resol resin that can be molded, but they can also be used as an adhesive or the like as an aqueous emulsion of the solid modified resol obtained after the above reaction.

The fine spherical modified resol resin particles of the present invention, if necessary, thermoplastic resin, thermosetting resin, flame retardant, foaming agent, reinforcing agent, filler, extender, leveling agent, flow regulator, stabilizer, It can also be used as a composition with an antistatic agent, an electric conductive agent, a dye or pigment, or the like.

Examples of the thermoplastic resin include polyethylene, polypropylene, polystyrene, rubber-modified polystyrene, A
Polyolefin such as S, ABS, polyvinyl chloride, polymethylmethacrylate, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyester such as polyarylate, polycaprolactam, polyhexamethylene adipamide, etc. Examples thereof include polyamide, polysulfone, polyphenylene sulfide and the like.

Examples of thermosetting resins include melamine resins, urea resins, furan resins, alkyd resins, unsaturated polyester resins, and the like.

Examples of flame retardants include halogen compounds such as decabromodiphenyl ether, and inorganic and organic phosphorus compounds.

Examples of the reinforcing agent, filler, extender and the like include glass fiber, asbestos fiber, carbon fiber, metal fiber, quartz, mica, asbestos, kaolin, aluminum oxide, silica, aluminum hydroxide, antimony trioxide and the like. Other additives include titanium oxide, iron oxide, aluminum powder, iron powder, metallic soap, carbon black, wood powder, paper and the like.

<Examples> Hereinafter, the present invention will be specifically described with reference to Examples.

In the following examples, the gelation time shows the gelation time at 150 ° C., and the flow characteristics are based on JIS-K-6910.

Example 1 In a three-necked flask of 1, 180 g of phenol, 37 wt
% Formalin 200g, urea 20g, water 120g, hexamethylenetetramine 18g and calcium chloride 8.4g
Is added with stirring to form a uniform solution, and 5.8 g of potassium fluoride is added to this solution with stirring, and 85% is added in 60 minutes.
C., and reacted at the same temperature for 90 minutes to obtain a fine spherical melamine-containing resole resin emulsion.

Next, the content of the flask was lowered to 30 ° C., 0.5 water was added, the supernatant was removed, and the microsphered resin particles in the lower layer were washed with water and air dried. Then, this was dried under reduced pressure (5 mmHg or less) at 50 to 60 ° C. for 24 hours to obtain fine spherical urea-containing modified resol resin particles having gelation time of 50 seconds, flow characteristics of 22 mm, and average particle diameter of about 40 μm. It was confirmed from the micrograph that the particles had a shape similar to that shown in FIG.

Example 2 The same treatment as in Example 1 was carried out except that 180 g of phenol and 20 g of melamine were used to obtain gelled time of 42 seconds, flow characteristics of 20 mm, and fine spherical melamine-containing modified resole resin particles having an average particle size of about 45 μm. It was Further, it was confirmed from the micrograph that the particles had the same shape as in FIG.

Example 3 The same treatment as in Example 1 was conducted except that the amount of phenol was changed to 180 g and the amount of aniline was changed to 20 g, to obtain fine spherical aniline-containing modified resole resin particles having a gelling time of 70 seconds, a flow property of 25 mm and an average particle diameter of about 50 μm. It was It was confirmed from the micrograph that the particles had a shape similar to that shown in FIG.

Comparative Example 1 Referring to the method described in JP-B-32-993,
A urea-containing resole novolak resin was prepared.

That is, in a three-neck flask of 1, phenol 100
g, 37 wt% formalin 100 g, urea 2.5 g and 28 w
Add 7 g of t% ammonia water with stirring, and add 95 to 10
It was kept at 0 ° C. and reacted for 45 minutes. Next, it is cooled to 95 ° C., 1.0 g of 20 wt% hydrochloric acid is added, and again at 95 ° C.
Let react for minutes. The contents were cooled to 50 ° C., the supernatant was removed and the viscous product was washed twice with water, then 75-8
It was dried at 5 ° C and 60 to 70 mmHg for 6 hours to obtain a pale yellow solid resin. Then, crush it with a ball mill to about 100
Granules of about μm were obtained. The resin particles thus obtained had a gelation time of 20 seconds and a flow property of 11 mm.

Comparative Example 2 A microspherical urea-containing phenol resin was produced with reference to the method described in JP-A-58-17114.

That is, in a two-necked three-necked flask, 405 g of 37 wt% formalin, 214 g of 35 wt% hydrochloric acid and 881 g of water were put, and 30 g of phenol and 20 g of urea were added to this.
g, 37wt% formalin 8.4g and water 4.1g mixed aqueous solution
After 62.5 g was added and stirred for 20 seconds, the mixture was allowed to stand for 60 minutes. Then, the temperature was raised to 80 ° C. in 60 minutes with occasional stirring, the mixture was stirred at the same temperature for 30 minutes, the contents were cooled to 30 ° C., filtered, washed with water and dried to obtain an average particle size of about 30
As a result, a fine particle phenol resin having a gelation time of 10 seconds and a flow property of 8 mm was obtained.

Since the modified resol resin particles obtained in Examples 1 to 3 have their surfaces covered with a substantially water-insoluble inorganic salt containing a fluorine atom, there is no fusion of the resin during the reaction or after the drying. The crushing step is not required unlike Comparative Example 1.

Further, it can be seen that the modified resol resin particles obtained in Examples 1 to 3 have very good fluidity during melt molding as compared with the resins obtained in Comparatives 1 and 2, and are suitable for melt molding.

<Effects of the Invention> As described above, the fine spherical modified resol resin particles of the present invention are those whose surface is coated with a substantially water-insoluble inorganic salt containing a fluorine atom, and thus storage stability It has excellent properties and can be stored for a long period of time without fusion of particles. Moreover, since the particles are fine spherical solid particles having a particle size of 500 μm or less, they are easy to handle during use, unlike conventional particles in the form of a solution or powder.

Further, in the method of the present invention, since substantially water-insoluble inorganic salts containing a fluorine atom are allowed to coexist in the reaction system and reacted, stable production as fine spherical solid particles of 500 μm or less is required. In addition to the above, it is possible to obtain solid microsphere particles having a sharp particle size distribution as compared with the granular resole resin produced by the conventional method.

Furthermore, the modified resol resin particles of the present invention are excellent not only in water resistance, alkali resistance, arc resistance and heat resistance, but also in moldability and thermosetting property.

[Brief description of drawings]

FIG. 1 is a scanning electron micrograph (magnification: 3000 times) showing an example of the structure of the fine spherical modified resol resin particles of the present invention.

Claims (10)

[Claims] 1. A part or all of the surface is coated with a substantially water-insoluble inorganic salt containing a fluorine atom,
0.2 to 3.5 for phenols that make up resole resin
Microspherical modified resol resin particles comprising a resole resin copolymerized with a nitrogen-containing compound, characterized by containing the above-mentioned inorganic salts by weight and having a particle size of 500 μm or less. 2. A substantially water-insoluble inorganic salt containing a fluorine atom is at least one inorganic salt selected from the group consisting of calcium fluoride, magnesium fluoride and strontium fluoride. The fine spherical modified resole resin particles according to the first aspect. 3. The nitrogen-containing compound is at least one nitrogen-containing compound selected from the group consisting of aromatic amine compounds having at least one active hydrogen bonded to a nitrogen atom, amide compounds and thioamide compounds. The fine spherical modified resol resin particles according to item 1 above. 4. The fine spherical modified resol resin particles according to claim 3, wherein the aromatic amine compound having at least one active hydrogen bonded to a nitrogen atom is aniline and toluidine. 5. The microspherical modification according to claim 1, wherein the nitrogen-containing compound is at least one nitrogen-containing compound selected from the group consisting of urea, thiourea, melamine, guanidine, guanamine and dicyandiamide. Resol resin particles. 6. When reacting a phenol, an aldehyde and a nitrogen-containing compound in an aqueous medium in the presence of a basic catalyst, the reaction system contains 0.2 to 3.5% by weight of a fluorine atom based on the phenol. Microsphere-modified resole resin made of a resole resin copolymerized with a nitrogen-containing compound, characterized in that it reacts in the presence of substantially water-insoluble inorganic salts to form particles having a particle size of 500 μm or less Particle manufacturing method. 7. The nitrogen-containing compound is at least one nitrogen-containing compound selected from the group consisting of aromatic amine compounds having at least one active hydrogen bonded to a nitrogen atom, amide compounds and thioamide compounds. 7. A method for producing fine spherical modified resol resin particles according to claim 6. 8. The method for producing fine spherical modified resol resin particles according to claim 7, wherein the aromatic amine compound having at least one active hydrogen bonded to a nitrogen atom is aniline and toluidine. 9. The microspherical modification according to claim 6, wherein the nitrogen-containing compound is at least one nitrogen-containing compound selected from the group consisting of urea, thiourea, melamine, guanidine, guanamine and dicyandiamide. Method for producing resol resin particles. 10. The substantially water-insoluble inorganic salt containing a fluorine atom is at least one inorganic salt selected from the group consisting of calcium fluoride, magnesium fluoride and strontium fluoride. A method for producing fine spherical modified resole resin particles according to claim 6.