JP2008248158A - Method for producing phenolic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method for obtaining a phenol resin having excellent physical properties with higher heat resistance and strength than conventional phenol resins.
At least one inorganic compound selected from the group consisting of silicon oxides, metal oxides, metal hydroxides, and metal carbonates when an aldehyde and a phenol are reacted under a catalyst. A method for producing a phenol resin, comprising adding and reacting an organic-inorganic composite (3) comprising (1) and at least one organic polymer (2) selected from polyamide, polyurethane, and polyurea .
[Selection figure] None

Description

  The present invention relates to a method for producing a phenol resin from which a high-strength cured product is obtained.

  Phenol resin uses its excellent heat resistance, adhesiveness, mechanical properties, electrical properties, price advantage, etc., and molding materials for various base materials, binders for friction materials, binders for abrasives, adhesives for wood It is widely used as a bonding agent, a binder for laminated materials, a binder for molds, a coating agent, an epoxy resin curing agent, and the like. Examples of phenol resins for reacting phenols with aldehydes include alkali resole resins using alkali metal or alkaline earth metal hydroxides as catalysts, ammonia resole resins using ammonia, and high-ortho type resins using divalent metal salts. In addition, novolak resins using acids as catalysts are generally known. Furthermore, modified phenolic resins obtained by reacting or adding various modifiers to these resins are also in practical use. In recent years, phenol resins for these uses have been required to have further improved heat resistance and high strength when used as various binders such as friction materials, abrasives, and molds. This requirement is common to both resol-type phenolic resins and novolac-type phenolic resins, and each resin is used in various fields of use. In some cases, resole-type resins and novolak-type resins are used in combination. It may be used (for example, refer to Patent Document 1). Further, the form of use may be solid or powder, or a solvent solution or aqueous solution dissolved in a solvent such as alcohol or ketone. However, the strength of the cured product obtained may be insufficient.

JP2003-137948

  An object of the present invention is to provide a production method capable of obtaining a phenol resin having excellent physical properties with higher heat resistance and strength than conventional phenol resins.

  The present inventor has obtained a high strength, high moldability and heat resistance by reacting an aldehyde and a phenol in the presence of a complex of an inorganic compound and an organic compound in the production of a phenol resin. As a result, the present invention has been completed.

  That is, the present invention provides at least one selected from the group consisting of silicon oxides, metal oxides, metal hydroxides, and metal carbonates when reacting aldehydes and phenols under a catalyst. A phenol resin characterized by adding and reacting an inorganic compound (1) with an organic-inorganic composite (3) comprising at least one organic polymer (2) selected from polyamide, polyurethane, and polyurea A manufacturing method is provided.

  In the method for producing a phenol resin of the present invention, a complex of an inorganic compound and an organic compound is added and reacted when a phenol monomer and an aldehyde are reacted in the presence of a catalyst.

  When producing a resole resin, a catalyst such as an alkali metal, an alkaline earth metal, ammonia, or a divalent metal salt is used alone or in combination. When producing a novolac resin, various acids and divalents are used. Metal salts are used alone or in combination. The reaction process is as follows. In the case of a resole resin, phenols, aldehydes and a catalyst such as sodium hydroxide are added and reacted at 50 to 110 ° C. for 1 to 10 hours. Just do it. When a solvent-soluble resin is produced, a solvent may be added before dehydration under reduced pressure, or a solvent may be added at a time when moisture is appropriately adjusted by dehydration under reduced pressure. The complex of an inorganic compound and an organic compound may be added simultaneously with the addition of phenols and formaldehydes, or may be added midway. When producing novolak resin, for example, using oxalic acid as a catalyst for phenols and formaldehydes, reacting at 100 ° C. for 1 to 5 hours, and then adjusting to a predetermined solution viscosity or softening point through normal pressure dehydration and vacuum dehydration steps good. At this time, the composite of the inorganic compound and the organic compound may be added at the same time as the raw material monomer is charged, or may be added before the reaction is completed and dehydration under reduced pressure is started.

  The phenols used as a raw material are not particularly limited. For example, phenols or alkylphenols such as cresol, xylenol, ethylphenol, butylphenol and octylphenol, polyhydric phenols such as resorcin and catechol, halogenated phenols, Examples include phenylphenol and aminophenol. In addition, these phenols are not limited to one type, and two or more types can be used in combination. In order to obtain a water-soluble resole resin, resorcin and a normal phenol monomer are preferable, but in order to obtain an inexpensive product, a phenol monomer is preferable. A novolak resin itself having a molecular weight of about 200 to 500 can also be used as a raw material.

  As the aldehydes of the present invention, formaldehyde such as formaldehyde, paraformaldehyde, and trioxane, acetaldehyde, and the like that are commonly used in the production of phenol resins are effective, and urotropine can also be used.

  As the acids used as a catalyst in the present invention, acids generally used in the production of novolak resins can be used. For example, oxalic acid, hydrochloric acid, phosphoric acid, sulfuric acid, paratoluenesulfonic acid, phenolsulfonic acid and high ortho novolak resin Zinc acetate, zinc octylate and the like, which are catalysts for the above, are used.

  As the catalyst for the resol resin used in the present invention, generally used catalysts such as sodium hydroxide, potassium hydroxide, lithium hydroxide, barium hydroxide, calcium hydroxide, ammonia, triethylamine and the like are used. As the form of the resole resin, there are both those obtained as a solid and those obtained as a solution.

  The ratio (molar ratio) of phenols / aldehydes in the production of the resole resin of the present invention is preferably 1.0 to 4.0 (molar ratio) in the resole resin. When the molar ratio is 1.0 or less, a large amount of unreacted phenol monomer remains, and when it is 4.0 or more, a large amount of unreacted formaldehyde monomer remains. In the novolak resin, 0.5 to 0.9 (molar ratio) is preferable. If it is 0.5 or less, the reaction yield is low and not economical, and if it is 0.9 or more, there is a risk of gelation due to high molecular weight during production.

  In addition, the phenolic resin produced in the present invention may be a modified phenolic resin by using, for example, an epoxy resin or a triazine in combination at any ratio in the resin synthesis process in addition to a composite of an inorganic compound and an organic compound. I can do it.

Adding a silane coupling agent to the phenol resin containing the composite of the inorganic compound and the organic compound of the present invention is effective for improving the strength of the resin itself.
Examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycol. Sidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldi Ethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) ) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl- N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane, etc. But can give. Among these, 3-glycidoxypropyltriethoxysilane as an epoxy silane coupling agent, 3-glycidoxypropyltriethoxysilane and 3-aminopropyltriethoxysilane as aminosilane coupling agents are preferably used.
Although the addition amount of a silane coupling agent is not specifically limited, 0.1 to 5 weight% is preferable with respect to the phenol resin solid content containing the composite_body | complex of glass and polyamide. The range of 0.3% to 3% is particularly preferable.

The added amount of the composite of the inorganic compound and the organic compound of the present invention to the phenol resin is 2 to 50% by weight based on the physical properties of the phenol monomer used in the synthesis of the phenol resin. The range of 3 to 30% by weight is more preferable. If the added amount is 2% by weight or less, the effect of improving the strength and the thermal stability is not remarkable, and if it exceeds 50% by weight, the viscosity at the time of synthesis increases and it may be difficult to produce. come.

The composite of the inorganic compound and the organic compound of the present invention is produced through the following steps if an example of polyamide is taken. It is obtained by performing a polycondensation reaction of monomers at the interface from the diamine monomer in the aqueous phase (A) and the acylated dicarboxylic acid monomer in the organic liquid phase (B). When this interfacial polycondensation reaction is carried out, this composite simultaneously produces polyamide and forms a uniform composite with glass by allowing water glass to coexist in the aqueous phase (A). A combination of 1,6-diaminohexane as a diamine monomer as a raw material of polyamide and adipoyl dichloride as a carboxylic acid monomer are preferably used. Water glass is a glass having alkali metal (M), silicon and oxygen as main constituent elements and generally having a composition formula of M ₂ O · nSiO ₂ . The alkali metal (M) is preferably an alkali metal such as sodium or potassium, and n is preferably 1.2 ≦ n ≦ 4. For example, a sodium silicate solution (No. 3) manufactured by Kishida Chemical Co., Ltd. {compositional formula Na ₂ O.3,1SiO ₂ , moisture = 60 wt%} corresponds to this.

  The aqueous phase (A) and the organic liquid phase (B) are prepared separately. The aqueous solution phase (A) is obtained by adding water glass and a diamine monomer to water, and the order of addition is not particularly limited, and the obtained aqueous solution phase is preferably uniform and transparent. As the solvent used in the organic solution phase, solvents generally used for interfacial polycondensation such as toluene, xylene, chloroform and cyclohexane are used.

  The reaction is carried out by contacting the aqueous solution phase thus obtained with the solvent liquid phase. At this time, the aqueous solution phase and the solvent solution phase may be added simultaneously and stirred uniformly. The reaction temperature can be carried out at a temperature in the range of -5 ° C to 40 ° C.

The composite of glass and polyamide thus obtained is separated by removing components other than the composite from the resulting mixture. Filtering is generally used as a separation method. In order to completely remove unreacted monomers and by-products after filtration, it is preferable to wash with an organic solvent such as acetone or water. Filtration and washing are followed by drying at room temperature or higher to obtain a spherical solid composite.
This composite often increases in density as the glass content increases, and this tendency is particularly strong in a composite having a glass content of 40% or more.
The measurement of the content rate of the glass in a composite here can be performed by removing a polyamide component by baking a composite at the temperature of 600 degreeC or more in air, and measuring an ash content. The ash after baking maintains the same shape as before baking, which indicates that the glass as an inorganic component is uniformly distributed in the polyamide matrix.

The weight percentage of ash can be controlled by setting the glass concentration conditions of the aqueous solution phase (A) at the time of synthesizing the composite. Generally, a high water glass concentration gives a high ash content, for example, in the aqueous solution phase (A). By setting the water glass concentration to 8 g / L, 15 g / L, and 40 g / L, the ash content in the composite can be 20% by weight or more, 40% by weight or more, and 60% by weight or more, respectively.
This composite preferably obtains glass components as spherical particles of 10 nm to 300 nm. This is because if the amount is not spherical, increasing the amount of phenol resin produced increases the viscosity and softening point of the resin and makes it difficult to produce.

The adhesion between the glass and the polyamide in the composite is good regardless of the size and shape of the ash.
Even if this complex is used for producing a phenol resin while containing moisture, there is no problem in reaction.

  In the present invention, when polyurethane or polyurea is used instead of polyamide, dichloroformate compounds and phosgene compounds may be used instead of acylated dicarboxylic acid monomers. The reaction conditions are the same as in the case of the polyamide.

  Next, the present invention will be described in more detail with reference to examples and comparative examples. The present invention is not limited to these examples.

  The measurement methods used for evaluation in the examples are as follows. In the examples, “parts” and “%” indicate “parts by weight” and “% by weight”, respectively.

  Strength: The obtained resin and glass powder (manufactured by Nippon Electric Glass Co., Ltd., EPG70M-10A average fiber length 75 μm, average fiber diameter 8.9 μm) are mixed in resin / glass powder = 3/7 (weight ratio) Then, after molding for 10 minutes so that the mold temperature is 150 ° C. and the bulk density after molding is 1.7, and after taking out from the mold, after curing for 3 hours at a temperature of 200 ° C., a thickness of 0.3 mm, Using a Shimadzu autograph, the test piece sliced into a width of 5.0 and a length of 60 mm was measured for bending strength at a load scale of 50 N, a test speed of 30 mm / min, and a distance between fulcrums of 50 mm. Measurement temperature was 23 degreeC and 250 degreeC. Moreover, the alkali-proof strength when boiled at 100 ° C. for 5 hours in a 1% NaOH solution was also measured.

  Thermal behavior: A test piece prepared in the same manner as the above bending strength was sliced into a thickness of 2.5 mm, a length of 55 mm, and a width of 5 mm, using a solid viscoelasticity measuring device manufactured by Rheometric, Inc., with a frequency of 1 Hertz. The change in elastic modulus was measured at a rate of 3 ° C / min, Strain 0.02%, and a temperature range of 23 ° C to 350 ° C.

Production Example 1
(A) Manufacture of composite of inorganic compound and organic compound Water glass aqueous solution (manufactured by Kishida Chemical Co., Ltd., sodium silicate solution (No. 3) {compositional formula Na ₂ O.3,1SiO ₂ , moisture = 60 wt%} Stirring while adding distilled water to 3.75 g and 1,64-diaminohexane 4.64 g at room temperature to prepare a uniform and transparent 300 ml aqueous phase.To adipoyl dichloride 7.32 g toluene at room temperature In addition, 300 ml of an organic liquid phase that was uniformly transparent was prepared by stirring, and then the aqueous solution was put into a 1 L blender bottle (manufactured by Osterizer), and the attached stirring blade was stirred at 10,000 rpm, at 25 ° C. The organic solvent phase was added all at once, and a white complex immediately precipitated from the mixed solution, and the suspension was kept in a suspended state for 2 minutes, and the resulting complex was washed with acetone and then with distilled water. Kiyoshi Mr obtain a spherical composite water-containing solids 30 wt% of glass and polyamide. [Complex A]

Example 1
Manufacture of novolak resin A stirrer and thermometer were set in a 2 liter four-necked flask, and 941 g of phenol and 645.2 g of 37.2% formalin [phenol] / [formaldehyde] = (10 mol) / (0.8 mol), Subsequently, 314 g (10 wt% with respect to phenol) of the complex (A) was added. 4.705 g of oxalic acid dihydrate was added as a catalyst, the temperature was raised to the reflux temperature (100 to 102 ° C.), the reaction was performed for 3 hours, distillation was started, and the temperature was raised to 190 ° C. After performing vacuum distillation at 50 torr (6.65 kPa) for 1 hour, 1 g of epoxy silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical) was added and taken out into the vat. The obtained novolak resin in which the organic / inorganic composite was dispersed had a softening point of 120 ° C. and an unreacted phenol content of 0.1% as measured by the B & R method. 90 parts of the resulting novolak resin was mixed with 10 parts of hexamethylenetetramine as a curing agent and pulverized with a hammer-type mill. The obtained powdered resin had a temperature of 125 ° C., a flow rate measured at an inclination of 30 °, 30 mm, a stroke cure time measured on a hot plate of 150 ° C., and a capillary method melting point of 90 ° C.

Example 2
Manufacture of water-soluble resole resin A stirrer and thermometer were set in a 3 liter four-necked flask, and 941 g of phenol and 1290 g of 37.2% formalin [phenol] / [formaldehyde] = (10 mol) / (1.6 mol). In addition, 156.8 g (5 wt% based on phenol) of the complex (A) obtained in Example 1 was added. Next, 56 g of 48% potassium hydroxide was added, the temperature was raised to 80 ° C., the reaction was performed for 3 hours, vacuum distillation was performed until the viscosity reached 1100 mPa · s / 25 ° C., and then cooled to room temperature. Aminosilane (KBE-903 manufactured by Shin-Etsu Chemical Co., Ltd., 3.0 g) was added at room temperature to obtain a resol resin aqueous solution containing an organic / inorganic composite.
This resin had a non-volatile content at 135 ° C. of 75.1%, a viscosity of 1110 mPa · s / 25 ° C., and a gelation time at 150 ° C. of 99 seconds.

Example 3
Manufacture of solvent-type resol resin
A three-liter four-necked flask was equipped with a stirrer and thermometer, and 941 g of phenol and 1048 g of 37.2% formalin [phenol] / [formaldehyde] = (10 mol) / (1.3 mol), obtained in Example 1. 314 g of the complex (10 wt% with respect to phenol) was added, 47 g of 25% aqueous ammonia was added, and the mixture was heated to 80 ° C. and reacted for 3 hours. Thereafter, vacuum distillation was performed, and vacuum distillation was continued until the temperature in the flask reached 90 ° C. Next, 490 g of methanol was gradually added and the flask was cooled until the temperature in the flask reached 80 ° C. Thereafter, the mixture was cooled to room temperature to obtain a resole resin containing an organic / inorganic composite. The viscosity of this resin was 600 mPa · s / 25 ° C., the gelation time at 150 ° C. was 110 seconds, and the non-volatile content after drying at 135 ° C. × 1 hour was 68%.

Comparative Example 1
A stirrer and thermometer were set in a 2 liter four-necked flask, 941 g (10 mol) of phenol and 161 g (2.0 mol) of 37.2% formalin were added, and 6.6 g of oxalic acid dihydrate was added, and the reflux temperature was increased. The temperature was raised to (100 ° C.), and 527.0 g (6.5 mol) of 37% formalin was further added dropwise over 1 hour. After reacting at reflux temperature for 3 hours, distillation was started and the temperature was raised to 180 ° C. Thereafter, distillation under reduced pressure at 50 torr (6.65 kPa) was performed for 1 hour to obtain a novolak resin having a softening point of 108 ° C. and 0.5% of unreacted phenol in the B & R method. 90 parts of the resulting novolak resin was mixed with 10 parts of hexamethylenetetramine as a curing agent and pulverized with a hammer-type mill. The obtained powder resin had a temperature of 125 ° C., a flow rate measured at an inclination of 30 °, 26 mm, a stroke cure time measured on a hot plate of 150 ° C., 104 seconds, and a capillary method melting point, 92 ° C.

Comparative Example 2
After mixing 941 g (10 mol) of phenol and 1290 g (16 mol) of 37% formalin in a 3 liter four-necked flask, 56.46 g of 48% sodium hydroxide solution was added and reacted at 80 ° C. for 3 hours, followed by dehydration under reduced pressure. Was adjusted so that the viscosity at 25 ° C. was 650 mPa · s, and then cooled to 25 ° C. to obtain a resole resin. The non-volatile content of this resin was 73%, and the gelation time at 150 ° C. was 85 seconds.

Physical property evaluation example Next, as the physical property values of the resins obtained in the above examples and comparative examples, the bending strength and thermal physical property (viscoelasticity) evaluation results of the samples prepared by the method described above are as follows. there were.

1) Measurement results of bending strength Maximum point stress (unit: MPa)
23 ° C 250 ° C Alkali resistance
Example 1 146 96 118
Comparative Example 1 117 66 76
It can be seen that the phenol resin containing the glass-polyamide composite obtained in the present invention is superior in normal strength, heat resistance strength and alkali resistance strength than the resin not containing.

2) Measurement results of thermophysical properties Changes in storage elastic modulus (unit: Pa × 10 ¹⁰ ) at each temperature
50 ° C 100 ° C 200 ° C 300 ° C
Example 1 1.46 1.40 1.32 1.28
Comparative Example 1 1.60 1.48 1.20 0.86

  The phenol resin (phenol resin containing a glass / polyamide composite) obtained by the production method of the present invention had a low rate of change in storage elastic modulus with respect to temperature change, and was excellent in thermal stability.

  The phenol resin containing the organic / inorganic composite obtained by the production method of the present invention has properties that are superior in strength and thermal stability as compared with a normal phenol resin. The present invention makes use of these properties, ie, molding materials, friction materials, polishing cloths, grinding wheels, various impregnations, wood processing, refractory materials, castings, heat insulating materials, paints, various uses of phenolic resins such as for FRP molding. It can be applied to.

Claims (12)

At least one inorganic compound (1) selected from the group consisting of silicon oxides, metal oxides, metal hydroxides and metal carbonates, and at least one selected from the group consisting of polyamide, polyurethane and polyurea A method for producing a phenol resin, comprising reacting an aldehyde with a phenol in the presence of an organic-inorganic composite (3) comprising the organic polymer (2). The organic-inorganic composite (3) is an organic solution (A) in which at least one compound selected from the group consisting of dicarboxylic acid halides, dichloroformate compounds and phosgene compounds is dissolved in an organic solvent, and at least one alkali. At least one selected from the group consisting of metal oxides, metal hydroxides and metal carbonates of metal elements and transition metal elements of Groups 3 to 12 of the periodic table or typical metal elements of Groups 13 to 16 of the periodic table The method for producing a phenolic resin according to claim 1, wherein the metal compound is obtained by mixing and stirring and reacting a basic aqueous solution (B) containing diamine. At least one inorganic compound (1) selected from the group consisting of silicon oxides, metal oxides, metal hydroxides and metal carbonates in the reaction of aldehydes with phenols under a catalyst, polyamide A method for producing a phenol resin, comprising adding and reacting an organic-inorganic composite (3) comprising at least one organic polymer (2) selected from polyurethane and polyurea. The method for producing a phenol resin according to claim 1, wherein an average particle size of the inorganic compound (1) in the organic-inorganic composite (3) is 5 to 300 nm. The method for producing a phenol resin according to claim 1, wherein the content of the inorganic compound (1) in the organic-inorganic composite (3) is 20 to 80% by weight. The method for producing a phenol resin according to claim 1, wherein the inorganic compound (1) is at least one selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide, zinc oxide, and tin oxide. The organic-inorganic composite (3) is an organic solution (A) obtained by dissolving one kind of compound selected from the group consisting of a dicarboxylic acid halide, a dichloroformate compound and a phosgene compound in an organic solvent, a diamine, and an alkali silicate. (B-1) and / or a metal compound (b-2) having two or more metal elements containing at least one alkali metal selected from the group consisting of metal oxides, metal hydroxides and metal carbonates. The manufacturing method of the phenol resin of Claim 1 which is an organic inorganic composite obtained by mixing and stirring and reacting the basic aqueous solution (B) to contain. The method for producing a phenol resin according to claim 1, wherein the amount of the presence / absence machine complex (3) is 2 to 50 wt% with respect to the phenol monomers. The manufacturing method of the phenol resin of Claim 1 which adds a coupling agent (4) when manufacturing a phenol resin. The method for producing a phenol resin according to claim 7, wherein the coupling agent (4) is a silane coupling agent. The method for producing a phenol resin according to claim 1, wherein the phenol resin is a resol resin. The method for producing a phenol resin according to claim 1, wherein the phenol resin is a novolac resin.