JPH06136080A - Production of silicone-modified novolak resin - Google Patents

Abstract

PURPOSE:To obtain a silicone-modified novolak resin excellent in curability and mechanical strength, also highly excellent in water resistance and flexibility by reaction between a phenolic compound, an aldehyde and a specific modifier in the presence of an acid catalyst. CONSTITUTION:The resin can be obtained by reaction, in the presence of an acid catalyst (pref. hydrochloric acid, salicylic acid), between (A) a phenolic compound, (B) an aldehyde and (C) as modifier, a silicone-based addition polymer prepared by reaction between (1) a hydrogenorganosiloxane of formula I (R1 and R2 are each alkyl or phenyl; n is 10-100) and a polyfunctional aromatic polyallyl compound of formula II (R3 is H, halogen, etc.; R4 is of formula III, SO2, etc.; m is 0-10) so as to be 10-50 pts.wt. of the component C based on 100 pts.wt. of the component A. It is preferable that the reaction be made using a reaction solvent such as an alcohol 80-200 deg.C in the boiling point at normal pressures.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a silicone-modified novolac resin which has excellent curability and mechanical strength, and is extremely excellent in water resistance and flexibility.

[0002]

BACKGROUND OF THE INVENTION Phenolic resins are widely used in various fields of industry because they have excellent characteristics such as heat resistance, abrasion resistance, mechanical strength, electrical insulation, low smoke generation, and acid resistance. This is a well-known fact. However, water resistance and flexibility are insufficient, and modified phenolic resins have been actively researched in order to improve these drawbacks while making the most of the above-mentioned excellent features. Silicone-modified phenolic resin is expected as a resin that may be capable of imparting flexibility and flexibility while maintaining mechanical strength to the phenolic resin. Regarding the silicone-modified phenol resin, JP-A-58-47013 and JP-A-6-
No. 2-124116, Japanese Patent Laid-Open No. 62-136860 and Japanese Patent Laid-Open No. 62-174222. However, according to these patent publications and the like, a silicone-modified phenolic resin that is excellent in curability and mechanical strength, and that is also excellent in water resistance and flexibility has not existed yet.
The reason why it does not exist is that it is extremely difficult to set the modification reaction conditions because the phenolic compound and the silicone compound are originally incompatible, and even if it is said to be a silicone-modified phenolic resin, the silicone compound is almost chemically bonded. It is considered that this is because the phenolic OH group is used as a functional group at the time of silicone modification, and the phenol component in the synthesized silicone-modified phenol resin is reduced.

[0003]

The method for producing a silicone-modified novolac resin according to the present invention has excellent properties inherent to the novolac resin such as curability and mechanical strength, and water resistance and flexibility which have been conventionally required to be improved. As a result of earnest research to obtain a novolak resin having both properties of silicone, a silicone-modified novolak resin obtained by a manufacturing method comprising reacting an organosiloxane compound having a phenol skeleton as a modifier during the synthesis of a phenol resin Has been found to be effective, and based on this finding, various studies have been repeated and completed. The object of the present invention is to obtain a silicone-modified novolak which is excellent in water resistance and flexibility without impairing many excellent features such as curability and mechanical strength of the unmodified novolac resin. It is to provide a method for producing a resin. Therefore, the novolak resin obtained by the production method of the present invention, which has good water resistance and flexibility, is used for grindstones, friction materials, rubber compounding, electrical insulation, paints, molding materials, and various It can be effectively used as a novolak resin for applications such as binding of organic substances and inorganic substances.

[0004]

MEANS FOR SOLVING THE PROBLEMS The present invention is represented by phenols (a), aldehydes (b), and hydrogenorganosiloxane represented by the following formula [I] as a modifier and the following formula [II]. Silicone-based addition polymer (c) obtained by reacting with polyfunctional aromatic polyallyl compound
And the silicone-based addition polymer (c) is reacted at a ratio of 10 to 50 parts by weight with respect to 100 parts by weight of the phenols (a) in the presence of an acid catalyst. It is a manufacturing method of a novolac resin.

[0005]

[Chemical 1]

[0006]

[Chemical 2]

Each component used in the present invention will be described below. (Phenols) Phenols (a) used in the present invention
As, one or more selected from phenol, orthocresol, metacresol, paracresol, ethylphenol, xylenol, bisphenol A, bisphenol F, catechol, resorcinol, hydroquinone, propylphenol, propenylphenol, butylphenol, octylphenol, nonylphenol, or the like. Two or more can be used. (Aldehydes) Aldehydes (b) used in the present invention
As formaldehyde, paraformaldehyde,
One or more selected from trioxane, acetaldehyde, benzaldehyde and the like.

(Polysiloxane-Aromatic Polyallyl Compound Addition Polymer) The polysiloxane-aromatic polyallyl compound addition polymer (c) used in the present invention usually comprises a hydrogenorganosiloxane and a polyfunctional aromatic polyallyl compound. It is a reaction product obtained by reacting in the presence of a platinum-based catalyst. The hydrogen organosiloxane used is a polysiloxane represented by the following formula [I], and its degree of polymerization (n) is in the range of 10 to 100.

[0009]

[Chemical 3]

If the degree of polymerization (n) is less than 10, the effect of improving the water resistance of the cured resin decreases, and if it exceeds 100, the reactivity with aldehydes decreases and it may be difficult to obtain a silicone-modified resin. The polyfunctional aromatic polyallyl compound is represented by the following formula [II], and its degree of polymerization (m) is in the range of 0-10.

[0011]

[Chemical 4]

If the degree of polymerization (m) exceeds 10, the effect of lowering the stress of the cured resin will be reduced. Further, the addition amount of the aromatic polyallyl compound to the polysiloxane is preferably 2 to 10 allyl groups in the aromatic polyallyl compound with respect to one hydrosilyl group in the polysiloxane. When it is less than 2, the molecular weight of the polysiloxane-aromatic polyallyl compound becomes too high and the reactivity with aldehydes decreases, and unreacted silicone remains during the synthesis of the silicone-modified novolac resin, resulting in a moisture resistance of the cured resin. When it exceeds 10, the strength of the cured product decreases. The reaction method can be appropriately selected, and the catalyst used at that time is preferably a platinum-based catalyst, and an isopropanol solution of platinum chlorate is particularly preferably used. After the reaction is complete, a liquid brown addition polymer is obtained at room temperature.

(Solvent) In the present invention, a solvent is usually used to homogenize the reaction system. As the type of solvent used, the boiling point at normal pressure is preferably 80 to 200 ° C.
1 or 2 or more selected from alcohols, ketones, ethers, esters, and cellosolves. (Acid catalyst) The acid catalyst used in the present invention includes hydrochloric acid,
One or more selected from sulfuric acid, benzoic acid, salicylic acid, paratoluenesulfonic acid, oxalic acid, phosphoric acid and the like.

Next, the formulation will be described. The aldehydes used in the method for producing the silicone-modified novolac are in the range of 0.5 to 1.0 mol, preferably 0.6 to 0.9 mol, per mol of the phenols. 0.5
When the amount is less than the molar amount, the molecular weight of the produced resin tends to be small and the mechanical strength tends to be lowered, and when it exceeds 1.0 mol, the melting point of the produced resin is high and the moldability becomes problematic. The compounding amount of the polysiloxane-aromatic polyallyl compound addition polymer with respect to 100 parts by weight of phenols is 10 to 50 parts by weight, and preferably 20 to 40 parts by weight. 1
If it is less than 0 parts by weight, the effect of improving the water resistance is small,
If it exceeds the weight part, the strength will decrease. The amount of the solvent used is preferably 5 to 200 parts by weight, more preferably 10 to 100 parts by weight, based on 100 parts of the phenol. If the amount of the solvent used is less than 5 parts by weight, it is difficult for the reaction solution to become a homogeneous system during the modification reaction, and unreacted silicone tends to remain, and if it exceeds 200 parts by weight, the concentration of the reaction solution decreases and the reactivity becomes low. And the unreacted silicone tends to remain, which is not preferable. The amount of the acid catalyst used is in the range of 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, based on 100 parts by weight of phenols. The reaction method is the same as in the case of a normal novolac resin. For example, the dehydration condensation reaction is performed at a reaction temperature of 60 to 200 ° C. for 1 to 20 hours.

[0015]

【Example】

(Synthesis of Addition Polymer of Polysiloxane-Aromatic Polyallyl Compound) << Reference Example 1 >> 1 to 100 parts by weight of hydrogen dimethylpolysiloxane having hydrogen groups at both ends with an average degree of polymerization of 10
After adding 2 parts by weight of a wt% isopropanolic chloroplatinate solution, the mixture was heated to 90 ° C. To this, 60 parts by weight of O, O'-diallylbisphenol A was added dropwise over 1 hour, after which the system was heated to 100 ° C. and the reaction was continued for 3 hours. After cooling, an addition polymer having a viscosity of 12700 cps was obtained. Reference Example 2 1 to 100 parts by weight of hydrogen dimethyl polysiloxane having hydrogen groups at both ends with an average degree of polymerization of 50
After adding 2 parts by weight of a wt% isopropanolic chloroplatinate solution, the mixture was heated to 90 ° C. To this, 15 parts by weight of O, O'-diallylbisphenol A was added dropwise over 1 hour, after which the system was heated to 100 ° C and the reaction was continued for 3 hours. After cooling, an addition polymer having a viscosity of 3200 cps was obtained. Reference Example 3 To 100 parts by weight of hydrogendimethylpolysiloxane having hydrogen groups at both ends with an average degree of polymerization of 150, 2 parts by weight of a 1% by weight isopropanol chloroplatinate solution was added, and then heated to 90 ° C. To this, 25 parts by weight of O, O'-diallylbisphenol A was added dropwise over 1 hour, after which the system was heated to 100 ° C and the reaction was continued for 3 hours. After cooling, an addition polymer having a viscosity of 5400 cps was obtained.

Example 1 100 parts of phenol, 65 parts of 37% formalin (0.75 mol per mol of phenol) in a reactor equipped with a stirrer, heat exchanger and thermometer, obtained by Reference Example 1 After adding 30 parts of an addition polymer of polysiloxane-aromatic polyallyl compound, 100 parts of methyl isobutyl ketone as a solvent, and 1 part of oxalic acid as a catalyst, a reflux reaction was carried out at normal pressure for 300 minutes, and then the liquid temperature was 1
The initial condensation reaction was completed by performing dehydration reaction at atmospheric pressure until the temperature reached 55 ° C. After that, the liquid temperature is 155 ° C and the vacuum degree is 60To.
A dehydration condensation reaction was performed for 1 hour at rr to obtain a silicone-modified novolac resin having a softening point of 92 ° C. << Example 2 >> 50 parts of meta-cresol, 50 parts of para-cresol in a reactor equipped with a stirrer, a heat exchanger, and a thermometer, 3
49% 7% formalin (0.65 for 1 mole of cresol)
Mol), 30 parts of an addition polymer of the polysiloxane-aromatic polyallyl compound obtained in Reference Example 1, 100 parts of methyl isobutyl ketone as a solvent, and 0.5 parts of oxalic acid as a catalyst, and refluxed under normal pressure for 300 minutes. After the reaction, the dehydration reaction was carried out at normal pressure until the liquid temperature reached 155 ° C. to complete the initial condensation reaction. After that, the liquid temperature is 155 ℃,
A dehydration condensation reaction was performed at a vacuum degree of 60 Torr for 1 hour to obtain a silicone-modified novolac resin having a softening point of 91 ° C.

Example 3 100 parts of phenol and 26.5 parts of 85% paraformaldehyde in a reactor equipped with a stirrer, a heat exchanger and a thermometer (0.7 per 1 mol of phenol).
0 mol), the polysiloxane obtained in Reference Example 2
After charging 40 parts of an addition polymer of an aromatic polyallyl compound, 100 parts of methyl isobutyl ketone as a solvent, and 1 part of oxalic acid as a catalyst, a reflux reaction was carried out at normal pressure for 300 minutes, and then the liquid temperature was kept at 155 ° C. The dehydration reaction was performed under pressure to complete the initial condensation reaction. Thereafter, a dehydration condensation reaction was performed at a liquid temperature of 155 ° C. and a vacuum degree of 60 Torr for 1 hour to obtain a silicone-modified novolac resin having a softening point of 90 ° C. << Example 4 >> 100 parts of phenol, 63 parts of 37% formalin (0.75 mol per 1 mol of phenol) were placed in a reactor equipped with a stirrer, a heat exchanger, and a thermometer, and the polysiloxane obtained in Reference Example 2 was used. -Add 40 parts of an addition polymer of an aromatic polyallyl compound, 100 parts of n-butyl alcohol as a solvent, and 1 part of oxalic acid as a catalyst, and add 300 at normal pressure.
After carrying out a reflux reaction for 1 minute, a dehydration reaction was carried out under normal pressure until the liquid temperature reached 155 ° C. to complete the initial condensation reaction. Then, a dehydration condensation reaction was performed for 1 hour at a liquid temperature of 155 ° C. and a vacuum degree of 60 Torr to obtain a silicone-modified novolac resin having a softening point of 91 ° C.

Comparative Example 1 100 parts of phenol, 65 parts of 37% formalin (0.75 mol per mol of phenol), and 1 part of oxalic acid as a catalyst were placed in a reactor equipped with a stirrer, a heat exchanger and a thermometer. After charging, a reflux reaction was carried out at normal pressure for 90 minutes, and then a dehydration reaction was carried out at normal pressure until the liquid temperature reached 155 ° C. to complete the initial condensation reaction. After that, the liquid temperature is 155
A novolak resin having a softening point of 92 ° C. was obtained by performing a dehydration condensation reaction at a temperature of 60 ° C. and a vacuum degree of 60 Torr. << Comparative Example 2 >> 100 parts of phenol, 65 parts of 37% formalin (0.75 mol per 1 mol of phenol) were placed in a reactor equipped with a stirrer, a heat exchanger, and a thermometer, and the polysiloxane obtained in Reference Example 1 -Add 5 parts of an addition polymer of an aromatic polyallyl compound, 100 parts of methyl isobutyl ketone as a solvent, and 1 part of oxalic acid as a catalyst, and add 300 at normal pressure.
After carrying out a reflux reaction for 1 minute, a dehydration reaction was carried out under normal pressure until the liquid temperature reached 155 ° C. to complete the initial condensation reaction. Then, a dehydration condensation reaction was performed for 1 hour at a liquid temperature of 155 ° C. and a vacuum degree of 60 Torr to obtain a silicone-modified novolac resin having a softening point of 93 ° C.

Comparative Example 3 100 parts of phenol, 65 parts of 37% formalin (0.75 mol to 1 mol of phenol) were placed in a reactor equipped with a stirrer, a heat exchanger and a thermometer. After adding 60 parts of an addition polymer of polysiloxane-aromatic polyallyl compound, 100 parts of methyl isobutyl ketone as a solvent, and 1 part of oxalic acid as a catalyst, a reflux reaction was carried out at normal pressure for 300 minutes, and then the liquid temperature was 1
The initial condensation reaction was completed by performing dehydration reaction at atmospheric pressure until the temperature reached 55 ° C. After that, the liquid temperature is 155 ° C and the vacuum degree is 60To.
A dehydration condensation reaction was carried out for 1 hour at rr to obtain a silicone-modified novolac resin having a softening point of 82 ° C. << Comparative Example 4 >> 100 parts of phenol, 65 parts of 37% formalin (0.75 mol per 1 mol of phenol), and polysiloxane obtained in Reference Example 3 in a reactor equipped with a stirrer, a heat exchanger, and a thermometer. -Add 40 parts of an addition polymer of an aromatic polyallyl compound, 100 parts of methyl isobutyl ketone as a solvent, and 1 part of oxalic acid as a catalyst.
After performing a reflux reaction for 0 minutes, a dehydration reaction was performed at normal pressure until the liquid temperature reached 155 ° C. to complete the initial condensation reaction. Thereafter, a dehydration condensation reaction was performed at a liquid temperature of 155 ° C. and a vacuum degree of 60 Torr for 1 hour to obtain a silicone-modified novolac resin having a softening point of 85 ° C.

The silicone-modified novolac resin or novolac resin 100 obtained in each of the above Examples and Comparative Examples
10 parts of hexamine was added to and mixed with each other, and finely ground to give a powder resin so that the 105 μm sieve residue was 1.0% or less.
The melting point, the flow and the gelation time of the powdered resin were measured according to JIS K 6909. The measurement results are as shown in Table 1.

[0021]

[Table 1]

(Measurement of characteristics by test piece) Examples 1 and 2
For the silicone-modified novolac resin prepared in accordance with Example 1 and the powder resin obtained by adding 10 phr of hexamine to the comparative silicone-modified novolac resin prepared in Comparative Examples 1 to 4, normal bending strength, wet bending strength, wet strength retention rate, The dynamic flexural modulus was measured. The measuring method is as follows. Normal bending strength Specimen preparation: Mixing ratio Powder resin: Alumina (# 400) = 4
0:60 (% by volume) Size 20 × 120 × 10 mm Hardening 160 ° C × 15 minutes Post-curing 200 ° C × 3 hours Apparent specific gravity 2.55 ± 0.02 Measurement: Using Tensilon type bending strength measuring machine Span 100 mm, load speed 20 mm / min

Wet bending strength Test piece preparation: Post-cured test piece under the same conditions as the state bending strength was surface-polished with sandpaper and then immersed in pressurized water at 110 ° C. for 2 hours. Measurement: State bending strength Calculated from the wet strength retention rate (wet flexural strength / normal flexural strength) x 100. Dynamic flexural modulus Test piece preparation: Cut post-cured test pieces under the same conditions as the state flexural strength. And polished to a size of 8 × 45 × 3.5 mm. Measurement: Rheograph piezo manufactured by Toyo Seiki Seisakusho, temperature rising rate 2 ℃ / min forced vibration 10Hz, measurement temperature room temperature ~
250 ° C (Measured values in Table 1 are readings at 200 ° C)

[0024]

According to the method for producing a silicone-modified novolac resin according to the present invention, water resistance and water resistance can be improved without deteriorating many excellent features such as curability and mechanical strength of ordinary novolac resins. Since it is possible to obtain a novolac resin having excellent flexibility, it is suitable as a method for industrially producing a novolac resin having good water resistance and flexibility. The silicone-modified novolac resin produced by this manufacturing method is strongly required for the development of a water-resistant and flexible novolac resin for grindstones, friction materials, rubber compounds, electrical insulation, paints, molding materials, Also, it is expected to be extremely effective when applied to applications such as bonding of various organic substances or inorganic substances.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Sumiya Miyake 1-2-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Sumitomo Bakelite Co., Ltd.

Claims (1)

[Claims] 1. Phenols (a), aldehydes (b),
And a silicone addition polymer (c) obtained by reacting a hydrogenorganosiloxane represented by the following formula [I] with a polyfunctional aromatic polyallyl compound represented by the following formula [II] as a modifier: 1] [Chemical 2] A method for producing a silicone-modified novolac resin, which comprises using 10 to 50 parts by weight of the silicone-based addition polymer (c) with respect to 100 parts by weight of a phenol (a) and reacting in the presence of an acid catalyst. .