JPS621748A - Microspherical resin composition and production thereof - Google Patents

Abstract

PURPOSE:The titled composition, consisting of a resol resin and a thermoplastic resin, having the surface partially or wholly coated with a specific inorganic salt and improved storage stability and adhesive characteristics and suitable to solid adhesives used for aircraft, etc. CONSTITUTION:A microspherical resin composition, obtained by reacting a phenol with an aldehyde in the presence of an inorganic salt substantially insoluble in water, e.g. calcium fluoride, 1-100wt%, based on the phenol, thermoplastic resin, e.g. polycapramide or polyhexamethylene adipamide and basic catalyst, e.g. aqueous ammonia, in an aqueous medium and having the surface partially or wholly coated with the inorganic salt and <=500mum particle diameter.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is made of a resol resin and a thermoplastic resin that are thermally reactive, exhibit extremely excellent adhesive properties when cured, and have excellent storage stability. The present invention relates to a microspherical resin composition and a method for producing the same.

<Prior art><Problems to be solved by the present invention> Resol resins are widely used as adhesives with excellent heat resistance and chemical resistance. Since the flexibility is poor, there is a problem in that the peel strength is low. On the other hand, thermoplastic resins are flexible and have excellent peel strength.

They are inferior in tensile strength and heat resistance, and both pose problems as so-called structural adhesives when used alone. For this reason, compositions consisting of thermosetting resins and thermoplastic resins are considered preferable for structural adhesives used in aircraft, automobiles, and the like. In order to increase the adhesive strength of a composition consisting of a thermosetting resin and a thermoplastic resin, it is believed that uniform and intimate mixing of both resins is an important factor, and various mixing methods have been proposed. Conventionally known methods such as the melt mixing method, solution mixing method, and single polymerization mixing method all have various problems and are not necessarily satisfactory, and improvements have been desired.

For example, in the melt mixing method, a thermosetting resin and a thermoplastic resin are melt-mixed and extruded, but there is often a large difference in the softening temperature of the two resins, as well as a large difference in melt viscosity. Because there are many.

Even melt extrusion is often difficult, and even if melt extrusion is possible, the degree of mixing is insufficient and the adhesive strength of the resulting composition is not always satisfactory. Also,
In order to use the composition obtained by this method as a powder, it not only requires a pulverization step following the melt extrusion step, but also the powder shape obtained is irregular and has poor fluidity, making it difficult to handle. There was a problem.

On the other hand, the solution mixing method is the most frequently used.

Although it can provide an adhesive with a high degree of mixing and excellent bonding strength, since both resins are dissolved in a solvent and the mixed solution is applied to the bonded area and dried, it causes environmental pollution due to continuous failure of the solvent. Not only are there economic problems due to non-recovery of solvents and solvents, but it is also difficult to provide compositions suitable for use in powder or solid form. Recently, The Br1
tissue Polymer Jour-nal+ νo
l 15. March, 1983. (Author: Chri
stopher G.

Demmer, Edward W., Garnish
The mixing during polymerization method published in , et al.) uses an aqueous emulsion stabilizer to polymerize a resol resin in the presence of a thermoplastic resin in an aqueous medium.
The composition comprising a resol resin and a thermoplastic resin obtained by this method exists in an aqueous emulsion state that cannot be taken out as a solid or powder. Furthermore, in order to use it as an adhesive, it is necessary to dry the moisture in the area where the adhesive is applied, which requires time for adhesion, and there is a problem of foaming when the moisture is continuously lost.

Means for Solving Problems> The present invention solves two or more conventional problems. That is, the first object of the present invention is as follows.

An object of the present invention is to provide microspherical solid particles of a resin composition comprising a resol resin and a thermoplastic resin, and a method for producing the same. A second object of the present invention is to provide a microspherical resin composition that has thermal reactivity and exhibits excellent adhesive properties, and a method for producing the same. A third object of the present invention is to provide a microspherical resin composition that does not fuse in a solid state and has excellent storage stability, and a method for producing the same.

As a result of intensive research to solve these problems, the present inventors have discovered that the objective can be achieved by emulsion polymerization of resol resin in the presence of thermoplastic resin using inorganic salts as emulsion stabilizers. Heading 1 The present invention has been achieved.

That is, 1) the present invention is made of a resol resin and a thermoplastic resin, 2 has a part or all of its surface coated with an inorganic salt that is substantially insoluble in water, and has a particle size of 500 μm or less. Spherical resin composition, phenols and aldehydes in an aqueous medium, substantially water-insoluble inorganic salts, 1 to 100 wt% based on phenols.
A part or all of the surface is coated with a substantially water-insoluble inorganic salt, and the particle size is 500 mm.
This is a method for producing a microspherical resin composition having a particle size of μm or less.

The present invention will be further explained in detail below.

The thermoplastic resin referred to in the present invention may be any resin as long as it can be dissolved in the phenols constituting the resol resin. Examples include polyolefins such as polyethylene, polypropylene, polystyrene, AS, ABS, polyvinyl acecool, and PMMA. , polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyarylate, polyamides such as polycapramide, polyhexamethylene adipamide, polyundecanamide, polylaurinamide, or partially methoxymethylated polyamides or copolymers thereof. polyamide,
Examples include polysulfone and polyphenylene sulfide, with polyamide and polyvinyl acetal being particularly preferred. Partially methoxymethylated polyamide is one in which the hydrogen atom bonded to the nitrogen atom constituting the amide bond is substituted with a methoxymethyl group, and the substitution rate is preferably in the range of 20 to 50 mol%.

The substantially water-insoluble inorganic salts referred to in the present invention are 25
Refers to inorganic salts having a solubility in water of 0.2 g/l or less at ℃2, such as calcium fluoride, magnesium fluoride, and strontium fluoride.

Calcium phosphate, magnesium phosphate, barium phosphate, aluminum phosphate, barium sulfate.

Examples include calcium sulfate, zinc hydroxide, aluminum hydroxide, iron hydroxide, etc., with calcium fluoride, magnesium fluoride, and strontium fluoride being particularly preferred.

The microspherical resin composition according to the present invention is made by coating the surfaces of nine particles with the above-mentioned substantially water-insoluble inorganic salts, and embodiments thereof will be described below.

Figure 1 is a scanning electron micrograph showing an example of the structure of the microspherical resin composition of the present invention.Extremely fine, substantially water-insoluble inorganic salts are deposited on the surfaces of the nine particles, covering the surfaces of the nine particles. There is. The coating of the substantially water-insoluble inorganic salt on the particle surface is effective when reacting phenols and aldehydes with a thermoplastic resin in the presence of a basic catalyst in an aqueous medium, as described below. It is formed by allowing water-insoluble inorganic salts to coexist with the coating material, but by appropriately changing the amount of the substantially water-insoluble inorganic salts added, a desired coating amount can be obtained.

The resin composition of the present invention coated with the substantially water-insoluble inorganic salt has a microspherical shape with a particle size of 500 μm or less, as shown in FIG. That is, the resin composition of the present invention differs from conventional powder or granular compositions in that each particle is microspherical, and no fusion of two particles is observed. The reason why the resin composition of the present invention has a microspherical shape and no fusion is observed is that the coating of substantially water-insoluble inorganic salts formed in the manufacturing method described below is formed during resin manufacturing and storage. It is presumed that this prevents particle fusion.

Thus, the microspherical resin composition of the present invention having the above structure has excellent storage stability because its surface is coated with a substantially water-insoluble inorganic salt, and particles do not melt for more than one year. It can be stored without causing damage, and 2
Since they are microspherical particles with a particle size of 500 μm or less, they are easy to handle during use such as molding.

Next, two methods for producing the microspherical resin composition of the present invention will be described.

First, the method of the present invention involves reacting phenols and aldehydes in an aqueous medium in the presence of a thermoplastic resin and a basic catalyst in the presence of a substantially water-insoluble inorganic salt in the reaction system. .

The phenols used here are phenol and phenol derivatives, and the phenol derivatives include 1
For example, m-alkylphenol substituted with an alkyl group having 1 to 9 carbon atoms, ○-alkylphenol, P-alkylphenol, m-cresol, p-te
r-butylphenol.

O-propylphenol, resorcinol, bisphenol A, and halogenated phenol derivatives in which part or all of the benzene nucleus or alkyl group hydrogen atoms are substituted with chlorine or bromine, etc.
A species or two or more species may be used. Note that the phenols are not limited to these, and any other compound containing a phenolic hydroxyl group can be used. Examples of the aldehydes used in the present invention include formaldehyde in any form such as formalin or paraformaldehyde, as well as furfural, and the molar ratio of the aldehydes to the phenols is 1 to 2. Preferably 1.1~
It is 1.4.

As mentioned above, the substantially water-insoluble inorganic salts are preferably calcium fluoride, magnesium fluoride, strontium fluoride, etc., and the amount thereof is 0.2 to lowt%, preferably 0.5% based on the phenol. ~3.5wt
%. In addition, in order to add substantially water-insoluble inorganic salts, the substantially water-insoluble inorganic salts may be directly added as described above, or the substantially water-insoluble inorganic salts added during the reaction may be added directly. Two or more types of water-soluble inorganic salts may be added so as to produce the following. That is, 1. For example, instead of fluorine compounds such as calcium, magnesium, and strontium, at least one water-soluble inorganic salt selected from the group consisting of sodium fluoride, potassium fluoride, and ammonium fluoride is used on one side, and calcium on the other side. It is also possible to add at least one selected from the group consisting of chloride, sulfate, and nitrate of magnesium and strontium to generate fluorine compounds of calcium, magnesium, and strontium during the two reactions.

As mentioned above, the thermoplastic resin used in the present invention is preferably a polyamide such as polycapramide, polyhexamethylene adipamide, polyundecanamide, polylaurinamide, etc., and the amount thereof depends on the phenols constituting the resol resin. 1 to 100 wt%, preferably 10 to 9
It is 0wt%.

Particularly preferred is 20-70-1%. If it is less than 1 wt%, the peel strength of the adhesive layer will be significantly weakened, and if it is more than 100 wt%, it will be difficult to form microspherical particles.

2. As the basic catalyst used in the method of the present invention, 1. Basic catalysts commonly used in the production of resol resins can be used. 1. For example, aqueous ammonia, hexamethylenetetramine, and alkyl amines such as dimethylamine, diethyltriamine, and polyethyleneimine. etc. The molar ratio of these basic catalysts to phenols is 0.02 to 0.
2 is preferred.

The reaction of the present invention is carried out in an aqueous medium, and in this case, the amount of water charged is 1. For example, the solid content concentration of the resin is 30 to 7.
It is desirable that the content be 0 wt%, preferably 50 to 604%. In the reaction of the present invention, for example, the heating rate is 0.5 to 1.5° C./min under stirring.

The temperature is gradually raised to an upper limit, preferably at a rate of 0.8 to 1.2°C/min, and the reaction temperature is 70 to 90°C, preferably 83 to 90°C.
The reaction is carried out at 87° C. for 60 to 150 minutes, preferably 80 to 110 minutes. After reacting in this manner, one reactant is cooled to 40° C. or lower to obtain a stable solid aqueous emulsion of a resin composition consisting of a resol resin and a thermoplastic resin.

Next, this aqueous emulsion is separated into solid and liquid by a conventional method such as filtration or centrifugation, and then washed and dried.
Particle size 5 whose surface is coated with substantially insoluble inorganic salts
A solid microspherical resin composition of the present invention with a diameter of 00 μm or less is obtained.

Note that the method of the present invention can be carried out by either a continuous method or a hatch method; however, 1 it is usually carried out by a batch method.

In the method of the present invention, phenols and aldehydes are prepared in an aqueous medium as substantially water-insoluble inorganic salts.

In carrying out the reaction in the presence of a thermoplastic resin and a basic catalyst, various additives such as a flame retardant such as phosphorus, a filler such as talc, or a blowing agent may be present as necessary.

The resin composition obtained by the method of the present invention as described above is smooth, non-fused microspherical solid particles, and as described above, has excellent stability, good flow characteristics, and excellent moldability. ing. In addition, the microspherical resin composition produced by the method of the present invention has good reactivity, a fast gelation rate, can be molded in a short time, and has good performance and quality of molded products. Furthermore, the microspherical resin composition obtained by the method of the present invention has a particle size of 500 μm or less,
Most of the particles are 100 μm or less, and the particle size distribution tends to be narrower than that of granular resin compositions produced by conventional methods.

The microspherical resin composition of the present invention is usually used as a moldable solid resin composition, but it can also be used as an adhesive or the like as an aqueous emulsion of the solid resin composition obtained after the above-mentioned reaction.

The microspherical resin composition of the present invention comprising a resol resin and a thermoplastic resin contains a thermoplastic resin, a thermosetting resin, a flame retardant, a blowing agent, and a reinforcing agent, as necessary.

Filler 5 Bulking agent, leveling agent, flow control agent, stabilizer.

Additives such as antistatic agents, electrically conductive agents, dyes and pigments can be added.

Examples of thermoplastic resins include polyethylene, polypropylene, polystyrene, rubber-modified polystyrene, A
S, ABS, polyolefins such as polyvinyl chloride, polymethyl methacrylate, ethylene-vinyl acetate copolymer, polyethylene terephthalate 1-. Polybutylene terephthalate.

Polyesters such as polycarbonates and polyarylates, polyamides such as polycaprolactam, -polyhexamethylene adipamide, and polysulfones.

Examples include polyphenylene sulfide.

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

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

Examples of reinforcing agents, fillers, extenders, etc. include glass fibers, asbestos fibers, carbon fibers, and metal fibers.

Examples include quartz, mica, asbestos, kaolin, aluminum oxide, silica, aluminum hydroxide, and antimony dioxide. Other additives include titanium oxide,
Examples include iron oxide, aluminum powder, iron powder, metal soap, carbon blank, wood powder and paper.

<Example> EXAMPLES The present invention will be specifically explained below using examples.

Example 1 80 g of phenol and 20 nylon 6 (Unideca side A1030B RL) tips in a 500 ml three-bottle flask
g was added with stirring, and the mixture was heated and melted at 85°C. Next, 4.2g of calcium chloride, 2.9g of potassium fluoride
After adding g and stirring for 10 minutes.

7.2 g of hexamethylenetetramine, 80 g of 37 wt % formalin, and 608 g of water were added, the temperature was raised to 85° C. over 40 minutes, and the mixture was reacted at the same temperature for 80 minutes to obtain a composition consisting of nylon 6 and resol resin.

The contents of the flask were then allowed to cool to 30°C.

After adding 0.51 g of water, the supernatant liquid was removed, and the microspheroidal resin particles in the lower layer were washed with water and air-dried.

Next, this was heated under reduced pressure (5 mm/1 g or less) to 50 to 6
It was dried at 0°C to obtain microspherical resin composition particles having an average particle size of about 50 μm (Resin A). When the surface of this particle was observed using an electron microscope, a shape very similar to that shown in FIG. 2 was observed.

Examples 2 to 5 Among the reaction conditions of Example 1, phenol and nylon 6
(A1030BRL), 37 wt% formalin.

A microspherical resin composition with an average particle size of about 40 μm was obtained by processing in the same manner as in Example 1 except that the amounts of potassium fluoride, calcium chloride, and hexamethylene diamine were changed as shown in Table 1. The resin compositions were prepared as Resin B, Resin B,
They are called C, D, and E. When the surfaces of these particles were observed using an electron microscope, a shape very similar to that shown in FIG. 1 was observed.

Examples 6 to 8 Among the reaction conditions of Example 1, partially methoxymethylated nylon 6 (manufactured by Unitika ■ 8T) was used.
ype Nylon, methoxymethylation rate 31 mol%)
Example 1 by changing the amount of preparation as shown in Table 2.
The reaction was carried out under the following conditions to obtain a microspherical resin composition with an average particle size of about 40 μm. These are called resins F, G, and H, respectively. When the surfaces of these particles were observed using an electron microscope, a shape very similar to that shown in FIG. 1 was observed.

Comparative Example 1 200 g of phenol, 200 g of 37% formalin,
140 g of water, 18 g of hexamethylenetetramine, and 8.4 g of calcium chloride were poured into a 3-bottle flask (No. 31) while stirring to make a uniform solution, and 5.0 g of potassium fluoride was added thereto.
After adding 8 g, the temperature was raised to 85° C. over 60 minutes, and stirring was continued at the same temperature for 80 minutes.

After the reaction was completed, the contents were cooled to 40°C to produce a solid microspherical resol resin. Filter this out.

After washing with water and drying, a microspherical resol resin having an average particle size of about 50 μm was obtained. When the surface of this particle was observed using an electron microscope, a shape very similar to that shown in FIG. 1 was observed (resin ■).

Comparative Example 2 The Br1tish Polymer Journ
An aqueous emulsion of nylon-resol resin was obtained according to the method described in J. al., vol 15 March 1983.

That is, 80 g of phenol is placed in a three-bottle flask.
, ethylcellulose 0.3g, nylon 6 (Unitika H
Add 20 g of A1030B RL), heat to 80°C, and stir until the nylon is completely dissolved. Next, 2.5 g of polyvinyl acetate (mH125000),
sodium carboxymethyl cell
Added 2.5 g of ulose, 4.7 g of nonylphenol/ethylene oxide adduct, and further added 37 wt%
110 g of formalin was added, the pH was adjusted to 7 to 8 with 27 wt% aqueous ammonia, the temperature was raised to 80'C in 30 minutes, and the reaction was carried out at the same temperature for 80 minutes to obtain an aqueous emulsion of nylon 6-resol resin (Resin J). ).

In order to compare the adhesive strength of the obtained resins, Resins A to ■ were applied to the adhesive test piece by electrostatic coating, and Resin J was applied to the test piece and dried at 80°C for 30 minutes.
The adhesive strength was measured by pressing at 180 °C and 4 kg/cnl for 10 minutes. The results are shown in Table 3.

■ According to JIS K6854 (A/board - Aj2 board) ■
The resin composition obtained in Comparative Example 2 according to JIS K6850 (Al plate-Al plate) is solid and cannot be taken out, so it takes time to apply the adhesive and dry it. Furthermore, the adhesive strength is not ranked among the highest.

<Effects of the Invention> The resin composition comprising the resol resin and thermoplastic resin of the present invention not only can be taken out in the form of solid particles, but also has excellent storage stability without fusion between particles. . Furthermore, the resin composition of the present invention has a uniform particle size of 500 μm or less, and is easy to handle. Yet another one
The resin composition of the present invention has excellent thermosetting properties as well as excellent adhesive properties. Taking advantage of these features, the microspherical resin composition of the present invention can be used not only in all fields where ordinary phenolic resins are used, such as laminates and binders, but also in solid structural adhesives, especially for aircraft and automobiles. It is useful as a drug.

[Brief explanation of drawings]

FIG. 1 is a scanning electron micrograph (3000x magnification) showing an example of the structure of the microspherical resin composition of the present invention.

Claims (10)

[Claims] (1) Consisting of a thermoplastic resin of 1 to 100 wt% based on the resol resin and the phenols constituting the resol resin,
A microspherical resin composition characterized in that part or all of its surface is coated with a substantially water-insoluble inorganic salt, and the particle size is 500 μm or less. (2) The microspherical resin composition according to claim 1, wherein the thermoplastic resin is soluble in the phenols constituting the resol resin. (3) The microspherical resin composition according to claim 1 or 2, wherein the thermoplastic resin is polyamide. (4) The microspherical resin composition according to claim 3, wherein the polyamide is at least one selected from the group consisting of polycapramide, polyhexamethylene adipamide, polyundecanamide, and polylaurinamide. (5) Claims 1 to 4, wherein the substantially water-insoluble inorganic salt is at least one selected from the group consisting of calcium fluoride, magnesium fluoride, and strontium fluoride. microspherical resin composition. (6) A feature of reacting phenols and aldehydes in an aqueous medium in the presence of a substantially water-insoluble inorganic salt, a thermoplastic resin of 1 to 100 wt% relative to the phenol, and a basic catalyst. , part or all of the surface is coated with an inorganic salt that is substantially insoluble in water,
A method for producing a microspherical resin composition having a particle size of 500 μm or less. (7) Claim 6, wherein the thermoplastic resin is a thermoplastic resin soluble in the phenols constituting the resol resin.
Manufacturing method described in section. (8) The manufacturing method according to claim 6 or 7, wherein the thermoplastic resin is polyamide. (9) The manufacturing method according to claim 8, wherein the polyamide is at least one polyamide selected from the group consisting of polycapramide, polyhexamethylene adipamide, polyundecanamide, and polylaurinamide. (10) Claims 6 to 9, wherein the substantially water-insoluble inorganic salt is at least one selected from the group consisting of calcium fluoride, magnesium fluoride, and strontium fluoride. Manufacturing method.