JPH02173026A - Production of silicone-modified novolac resin - Google Patents

Abstract

PURPOSE:To produce a silicone-modified novolac resin improved in mechanical strengths, water resistance and flexibility by reacting a novolac compound with an organosiloxane compound in the presence of a specified solvent and a specified catalyst. CONSTITUTION:100 pts.wt. novolac compound of an unreacted phenol content <=7.0wt.% and a number-average MW of 300-1200, obtained by reacting a phenol with an aldehyde, and 5-80 pts.wt. organosiloxane compound having 2-8 gamma- glycidoxy-propyl and/or beta-(3,4-epoxycyclohexyl)ethyl groups as functional groups and a functional group equivalent of 300-10000 are dissolved in an at least one solvent of an atmospheric b.p. of 80-200 deg.C selected from among an alcohol, a ketone, an ether, an ester and a Cellosolve and reacted together in the presence of at least one catalyst selected from among an imidazole, an organophosphine and a tert. amine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a silicone-modified novolac resin which has excellent mechanical strength, water resistance and flexibility.

[Conventional technology]

It is a well-known fact that phenolic resin is widely used in various fields of industry because it has excellent features such as heat resistance, abrasion resistance, mechanical strength, electrical insulation, low smoke emission, and acid resistance. It is. However, water resistance and flexibility are insufficient, and modified phenolic resins are being actively researched in order to improve these drawbacks while taking advantage of the above-mentioned excellent features. Silicone-modified phenolic resins are expected to be a resin that may be able to impart flexibility and flexibility while maintaining characteristics such as mechanical strength to phenolic resins.

Regarding silicone-modified phenolic resin, JP-A-58-
No. 47013, JP-A-62-124116,
JP-A-62-136860, JP-A-62-174
There are publications such as Publication No. 222.

However, according to these patent publications, silicone-modified phenolic resins that have excellent properties such as mechanical strength, water resistance, and flexibility do not yet exist, and the reason for their non-existence is phenolic compounds. Because phenolic resins and silicone compounds are inherently incompatible, the modification reaction conditions must be set extremely carefully. This is thought to be because there is no such thing.

[Invention tries to solve! lH) The method for producing the silicone-modified novolac resin of the present invention is as follows:
The inherent excellent properties of novolac resin such as mechanical strength,
As a result of intensive research in an attempt to obtain a novolac resin that has both water resistance and flexibility, which have long been requested to be improved, we discovered that a novolac compound and an organosiloxane compound were allowed to react under limited conditions. We obtained the knowledge that the silicone-modified novolac resin obtained by the manufacturing method consisting of the above is effective, and based on this knowledge, we conducted various researches and finally completed this work.

The purpose of the present invention is to produce a silicone-modified novolac resin that has extremely good water resistance and flexibility without sacrificing many of the excellent features of ordinary novolac resins, such as mechanical strength. Our goal is to provide the following.

According to the method for producing a silicone-modified novolak resin of the present invention, a novolak resin with good water resistance and flexibility can be obtained.
It can be effectively used as a novolac resin for applications such as lumber mining, rubber compounding, electrical insulation, paints, molding materials, and binding of various organic and inorganic materials, and is effective in solving CHH. Means J The present invention provides a novolak compound obtained by reacting phenols and aldehydes, in which the content of unreacted phenols is 7.0% by weight or less and the number average molecular weight is 300 to 1200. A)
100 parts by weight, and has 2 to 8 T-glycidoxypropyl groups or/and β-(3,4-epoxycyclohexyl)ethyl groups as functional groups, and has a functional group equivalent of 3
Organosiloxane compounds having a molecular weight of 00 to 10,000 (
B) 5 to 80 parts by weight with a boiling point of 80 to 200 at normal pressure
It is dissolved in a solvent (C) containing one or more selected from alcohols, ketones, ethers, esters, and cellosolves at This is a method for producing a silicone-modified novolak resin, which is characterized by adding and reacting a catalyst (D) containing one or more selected types.

The novolanc compound (A) used in the method for producing a silicone-modified novolak resin of the present invention has an unreacted phenol content of 7.0% by weight or less, preferably 5.0% by weight or less, More preferably, it is 3.0 weight percent or less. Also,
The number average molecular weight of the novolac compound (A) is 3
00-1200, preferably 400-800. The organosiloxane compound (B) has a γ-glycidoxypropyl group or/and β-(3,
It has a 4-epoxycyclohexyl)ethyl group, and the number of functional groups is 2 to 8, preferably 3 to 5. In addition, organosiloxane compounds (
The functional group equivalent of B) is 300 to 10,000, preferably 500 to 5,000.

Further, the amount of the organosiloxane compound (B) to be blended is 5 to 80 parts by weight per 100 parts by weight of the novolak compound (A).
Parts by weight, preferably 10 to 50 parts by weight. Next, the type of solvent (C) used during the modification reaction may include other solvents if it contains one or more selected from alcohols, Kents, ethers, esters, and cellosolves. It's okay to do so. The boiling point of the solvent (C) is 80 to 200°C at normal pressure, preferably 100 to 180°C. The amount of solvent (C) used is 20 to 100 parts by weight of novolak compound (A).
800 parts by weight is preferable, more preferably 50 to 5 parts by weight.
00 parts by weight. The type of catalyst (D) used in the modification reaction may contain other catalysts as long as it contains one or more selected from imidazoles, organic bosphines, and tertiary amines. do not have.

The amount of catalyst (D) used is novolac compound (A) 100
It is preferably 0.1 to 5.0 parts by weight.

In the present invention, the content of unreacted phenols was measured by gas chromatography. In addition, the number average molecular weight was determined by high performance liquid chromatography (analytical column TSK
-GELG1000HgX1, TSK-GELG20
00HgX2, TSK-GEL G3000HgX
It was determined by correcting it using a calibration curve using a standard substance with a known molecular weight.

Furthermore, the functional group equivalent was measured by applying the hydrochloric acid-dioxane method of epoxy equivalent.

The content of unreacted phenols in novolac compounds is 7.
．． If it exceeds 0 weight percent, the reaction products between unreacted phenols and the organosiloxane compound will increase, and the reaction products between the dinuclear or more component of the novolac compound and the organosiloxane compound will increase. If the number average molecular weight of the novolac compound is less than 300, the number average molecular weight is too small, making it difficult to develop properties such as water resistance and flexibility. Not enough. In addition, the number average molecular weight is 12
If it exceeds 00, the number average molecular weight of the reaction product between the novolac compound and the organosiloxane compound becomes too large, resulting in low fluidity and poor moldability and processability.

When the number of functional groups in the organosiloxane compound is one, there is no crosslinking property, and the properties inherent to the novolak resin, such as heat resistance and mechanical strength, deteriorate in the reaction product with the novolak compound. Even when the number of functional groups is 9 or more, many unreacted functional groups remain in the reaction product with the novolac compound, resulting in poor properties such as water resistance and insulation. Furthermore, if the functional group equivalent of the organosiloxane compound is less than 300, the reactivity with the novolac compound is too large, and gelation may easily occur during the modification reaction, or the reaction product may have poor water resistance or flexibility. Features such as these are difficult to develop.

On the other hand, if it exceeds 10,000, the reactivity with the novolak compound is low and many unreacted components remain.
Mechanical strength is low.

Next, if the amount of the organosiloxane compound added to 100 parts by weight of the novolak compound is less than 5 parts by weight, the modification effect such as flexibility will be small because the amount is small, whereas if it exceeds 80 parts by weight, the reaction will occur. Mechanical strength is low because unreacted organosiloxane compounds tend to remain in the product.

If one or more solvents selected from alcohols, ketones, ethers, esters, and cellosolves are not used, the compatibility during the modification reaction of novolac compounds and organosiloxane compounds may be affected. This is not preferable because the reactivity decreases.

In addition, if the boiling point of the solvent at normal pressure is lower than 80°C, the reaction temperature during the modification reaction will be low, resulting in low reactivity, whereas if it exceeds 200°C, it will be difficult to completely remove the solvent after the modification reaction. This case is also unfavorable since the solvent tends to remain in the reaction product.

If one or more catalysts selected from imidazoles, organic phosphines, and tertiary amines are not used, the reactivity between novolac compounds and organosiloxane compounds will be poor or non-existent. Not suitable.

In the method for producing a silicone-modified novolak resin of the present invention, the phenols for obtaining the novolak compound (A) include phenol, orthocresol, metacresol, vala-cresol, ethylphenol, xylenol, bisphenol A1 biphenol F1 catechol, and resorcinol. , hydroquinone, propylphenol, propenylphenol, butylphenol, octylphenol, nonylphenol, etc.
A species or two or more species can be used. Furthermore, the aldehydes include one or more selected from formaldehyde, paraformaldehyde, trioxane, acetaldehyde, benzaldehyde, and the like. In this case, the bonding molar ratio F/P between phenols (P) and aldehydes (F) is preferably 0.5 to 1.0. Furthermore, hydrochloric acid, sulfuric acid, and fIi acids such as eating acid, benzoic acid, salicylic acid, and paratoluenesulfonic acid can be used.

The organosiloxane compound (B) in the method for producing a silicone-modified novolak resin of the present invention is a monomer polymer having structural units such as dimethylsiloxane, diphenylsiloxane, methylethylsiloxane, methylbutylsiloxane, methyloctylsiloxane, and methylphenylsiloxane. A polymer or copolymer having an average degree of polymerization of 20 to 300, and further containing a T-glycidquinpropyl group or/and β-(3,4-epoxycyclohexyl) as a functional group at the terminal or/and side chain. Those having 2 to 8 ethyl groups can be used.

In the method for producing a silicone-modified novolak resin of the present invention, alcohols as the solvent (C) include n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, 5ec-butyl alcohol, tert-butyl alcohol, n-amyl Alcohol, isoamyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, caprylic alcohol, nonyl alcohol, decyl alcohol, cyclopentanol, cyclohexanol, benzine alcohol, etc. Polyhydric alcohols include ethylene glycol, propylene glycol, trimethylene Glycol, 1,4-butanediol, 1.5-bentanediol, 1,6-hexanediol, etc. can be used.

Ketones include methyl ethyl ketone, methyl isobutyl ketone, cyclobutanone, cyclohexane, and acetophenone.

Ethers include n-propyl ether, n-butyl ether, isobutyl ether, n-amyl ether, isoamyl ether, methyl isoamyl ether, ethyl butyl ether, ethyl isobutyl ether, ethyl n-
Amyl ether, ethyl isoamyl ether, anisole, phenethole, tetrahydrofuran, etc. can be used.

In addition, esters include propyl formate, isobutyl formate, n-amyl formate, isoamyl formate, isopropyl acetate, propyl acetate, n-butyl acetate, isobutyl acetate, methyl propionate, ethyl propionate, n-propionate.
Propyl, isopropyl propionate, isobutyl propionate, isobutyl propionate, methyl benzoate, and the like can be used.

Furthermore, cellosolves include methyl cellosolve, ethyl cellosolve, n-propyl cellosolve, isopropyl cellosolve, n-butyl cellosolve, and isobutyl etherb.

In the method for producing a silicone-modified novolak resin of the present invention, imidazoles that can be used as the catalyst (D) are:
2-methylimidazole, 2-ethylimidazole, 2
-phenylimidazole, 2phenyl-4-methylimidazole, 2-heptadecyl imidazole, etc.
Organic phosphines include triphenylphosphine, tributylphosphine, phenylphosphine, diphenylphosphine, methyldiphenylphosphine, and the like. In addition, tertiary amines include triethylenediamine, triethanolamine, benzyldimethylamine, 1",8-diaza-
Bicyclo(5,4,0) undecene-7 (DBU) and the like.

In addition, in the method for producing a silicone-modified novolak resin of the present invention, a novolak compound (A) that has undergone a condensation reaction is used.
was kept in the reaction vessel without taking it out from the reaction vessel.-1
On top of that, organosiloxane compound (B) and solvent (C
) and then adding catalyst (D) to continuously produce a silicone-modified novolak resin.

〔Effect of the invention〕

According to the method for producing a silicone-modified novolac resin according to the present invention, it does not lose many of the excellent features of ordinary novolac resins, such as mechanical strength, and has extremely good water resistance and flexibility. Since it is possible to obtain a novolak resin having good water resistance and flexibility, it is suitable as a method for producing a novolak resin industrially. Silicone-modified novolac resin produced by this manufacturing method is used for grinding wheels, friction materials, rubber compounding, electrical insulation, paints, molding materials, etc., which strongly requires the development of novolac resins with good water resistance and flexibility. It is expected that it will be extremely effective in applications such as binding various organic or inorganic substances.

〔Example〕

EXAMPLES The present invention will be explained in detail below with reference to Examples, but the present invention is not limited by the Examples.

Note that "parts" and r%J described in production examples, comparative production examples, examples, comparative examples, etc. indicate "parts by weight" and "weight percent."

(1) Synthesis and production example of novolac compound (A) I In a reaction apparatus equipped with a PIl stirrer, heat exchanger, and thermometer, 10 moles of phenol, 5.5 moles of 85% paraform, 0 oxalic acid
．． After charging 1 mole and carrying out a reaction for 90 minutes at 100 to 105° C. under normal pressure, a dehydration reaction was carried out at normal pressure until the temperature reached 150”C to complete the first IJI condensation reaction.

Thereafter, a dehydration condensation reaction was carried out for 1 hour at a liquid temperature of 150°C and a vacuum of 60 Torr to form a novolac compound (A-1
) was obtained. The unreacted phenol content of the novolac compound (A-1) was 3.0%, and the number average molecular weight Mn was 458.

Production Example 2 10 moles of phenol, 37
% formalin 8.0 mol, hydrochloric acid 0.04 mol,
After 90 minutes of reflux reaction at normal pressure, the liquid temperature was 150℃.
The initial condensation reaction was completed by carrying out the dehydration reaction at normal pressure until . After that, the liquid temperature is 155℃ and the vacuum is 50Torr.
A dehydration condensation reaction was carried out for 1 hour to obtain a novolac compound (
A-2) was obtained. The unreacted phenol content of the novolac compound (A-2) is 2.3z, and the number average molecular weight Mn is 7.
It was 33.

Production Example 3 6 mol of metacresol, 4 mol of para-cresol, 8.0 mol of 37% formalin, and 0.04 mol of hydrochloric acid were charged into a reaction apparatus of the same type as Production Example 1, and after performing a reflux reaction at normal pressure for 90 minutes. , the dehydration reaction is carried out at normal pressure until the liquid temperature reaches 150℃! +1III synthesis reaction was completed.

After that, a dehydration condensation reaction was carried out for 1 hour at a liquid temperature of 155°C and a vacuum degree of 50 Torr to form a novolac compound (A3).
I got it. The unreacted cresol content of the novolac compound (A-3) was 6.6%, and the number average molecular weight Mn was 625.

Production Example 4 2 moles of bisphenol A were added to the same reactor as Production Example 1.
6 moles of phenol, 6.4 moles of 37% formalin, and 0.01 mole of oxalic acid were charged, and after performing a reflux reaction at normal pressure for 90 minutes, a dehydration reaction was carried out at normal pressure until the temperature of the liquid reached 150°C for initial condensation. The reaction has ended. After that, the liquid temperature is 155℃
A dehydration condensation reaction was carried out at a vacuum degree of 30 Torr for 2 hours to obtain a novolac compound (A4). The unreacted monomer content of this novolac compound (A-4) is 0.5%
, the number average molecular weight Mn was 910.

(2) Synthesis of Comparative Novolac Resin (a) Comparative Production Example 1 In a reactor equipped with a stirrer, heat exchanger, and thermometer, 10 moles of phenol, 6.2 moles of 37% formalin, and 0.1 mole of oxalic acid
After charging mol and carrying out a reflux reaction at normal pressure for 90 minutes,
The dehydration reaction was carried out at normal pressure until the liquid temperature reached 150°C to complete the initial condensation reaction. Thereafter, a dehydration condensation reaction was carried out for 30 minutes at a liquid temperature of 155'C and a degree of vacuum of 60 Torr to obtain a comparative novolac resin (a-1). The unreacted phenol content of comparative novolac resin (a-1) is 8.6
%, number average molecular Ji M n was 420.

Comparative Production Example 2 6 moles of phenol, 4 moles of octylphenol, 8.5 moles of 80% paraform, and 0.2 moles of oxalic acid were placed in a reactor of the same type as Production Example 1, and the mixture was heated at 100 to 105°C under normal pressure for 12 hours.
After the reaction was carried out for 0 minutes, the dehydration reaction was carried out at normal pressure until the liquid temperature reached 170°C to complete the initial condensation reaction. Thereafter, a dehydration condensation reaction was carried out for 1 hour at a liquid temperature of 180° C. and a vacuum degree of 60 Toyr to obtain a comparative novolac resin (a-2). The comparative novolak resin (a-2) had an unreacted upper limit content of 1.1% and a number average molecular weight Mn of 1,230.

(3) Synthesis Examples 1 to 4 of Silicone Modified Novolac Resin (E) Production Example 1 in a reaction apparatus equipped with a stirrer, heat exchanger, and thermometer
Novolac compounds (A-1) synthesized in ~4 ~ (A-
4) 100 parts, 20 parts of an organosiloxane compound (B) having a structural unit of dimethylsiloxane, an average degree of polymerization of 100, a functional group of 5 T-glycidoxypropyl groups in the side chain, and a functional group equivalent of 1610. , and 200 parts of di-butyl alcohol as the solvent (C) to make a homogeneous solution, and then 0 parts of DBUL as the catalyst (D) were added to give Table 1.
The initial reaction was carried out under the conditions shown below. Thereafter, the temperature of the reaction solution was raised to 160'C while distilling off the solvent at normal pressure.
The mixture was maintained at the same temperature under a reduced pressure of Torr for 1 hour to obtain a silicone-modified novolac resin (E).

100 parts of silicone-modified novolak resin (E) and 10 parts of hexamine were mixed, and the residue on the 105μ sieve was 1.0%.
It was finely pulverized to obtain a powdered resin as follows.

JIS K2S melting point, flow, and gelation time of powder resin
It was measured by the method of O3. The measurement results were as shown in Table 1.

Examples 5 to 10 100 parts of the novolac compound (A-2) synthesized in Production Example 2 in the same type of reaction apparatus as in Example 1, the types of structural units, average degree of polymerization, and types of functional groups as shown in Table 2. , the position of the functional group, the number of functional groups, the functional group equivalent and the predetermined blending amount of the organosiloxane compound (B), and n as the solvent (C).
- After charging 200 parts of butyl alcohol to form a homogeneous solution, 1.0 part of DBU was further added as a catalyst (D), and an initial reaction was carried out under the conditions shown in Table 2. Thereafter, the temperature of the reaction solution was raised to 160° C. while distilling off the solvent at normal pressure, and the pressure was reduced to 30 Torr and maintained at the same temperature for 1 hour to obtain a silicone-modified novolac resin (E). Furthermore, a powdered resin was prepared under the same conditions as in Example 1, and its properties were measured. The measurement results were as shown in Table 2.

Examples 11 to 16 In a reactor of the same type as Example 1, the novolac compound (A-2) synthesized in Production Example 2, 20 parts of the organosiloxane compound (B) used in Example 1, and the compounds shown in Table 3 were added. After preparing a homogeneous solution by preparing the solvent (C) of the type and predetermined amount, 0 parts of DBUl was further added as the catalyst (D), and an initial reaction was carried out under the conditions shown in Table 3.

Thereafter, the temperature of the reaction solution was raised to 160°C while distilling off the solvent at normal pressure, the pressure was reduced to 3G Torr, and the temperature was maintained at the maximum temperature shown in Table 3 for 1 hour to obtain a silicone-modified novolac resin (
E) was obtained. More examples! A powdered resin was prepared under the same conditions as in the case of , and its properties were measured, and the measurement results were as shown in Table 3.

Examples 17 to 20 In a reactor of the same type as Example 1, 100 parts of the novolac compound (A-2) synthesized in Production Example 2, 20 parts of the organosiloxane compound (B) used in Example 1, and a solvent ( After charging 200 parts of n-butyl alcohol as C) to make a homogeneous solution, catalyst (D) of the type and predetermined amount as shown in Table 4 was added, and an initial reaction was carried out under the conditions shown in Table 4. After that, the reaction solution was heated to 16 ml while distilling off the solvent at normal pressure.
The temperature was raised to 0°C, the pressure was reduced to 30 Torr, and the temperature was maintained for 1 hour to obtain a silicone-modified novolac resin (E).

Furthermore, a powder resin was prepared under the same conditions as in Example 1, and its properties were measured. The measurement results were as shown in Table 4.

Comparative Examples 1 to 2 The novolak compound (A-2) obtained in Production Example 2 and Comparative Production Example 2 and the comparative novolac resin (a-2
) was made into a powdered resin under the same conditions as in Example 1, and its properties were measured. The measurement results were as shown in Table 1.

(4) Comparative silicone-modified novolac resin (e
) Synthesis Comparative Examples 3 to 4 Comparative novolak resin (a-1) or (a-2) synthesized in Comparative Production Examples 1 to 2 in the same type of reaction apparatus as Example 1
100 parts, 20 parts of the organosiloxane compound (B) used in Example 1, and 200 parts of n-butyl alcohol as the solvent (C) were charged to make a homogeneous solution, and then the catalyst (
0 parts of DBUl was added as D), and an initial reaction was carried out under the conditions shown in Table 1. Thereafter, the reaction solution was heated to iso'c while distilling off the solvent at normal pressure, and maintained at the same temperature for 1 hour under a reduced pressure of 30 Torr to obtain a comparative silicone-modified novolac resin (e). Furthermore, a powdered resin was prepared under the same conditions as in Example 1, and its properties were measured. The measurement results were as shown in Table 1.

Comparative Examples 5 to 8 100 parts of the novolac compound (A-i) synthesized in Production Example 1 in the same type of reaction apparatus as in Example 1, the types of structural units, average degree of polymerization, and types of functional groups as shown in Table 2. , the position of the functional group, the number of functional groups, the functional group equivalent and the predetermined blending amount of the comparative organosiloxane compound (b), and the solvent (C)
After preparing 200 parts of n-butyl alcohol as a homogeneous solution, as a catalyst (D), D B Ul, 0
The initial reaction was carried out under the conditions shown in Table 2. Thereafter, the temperature of the reaction solution was raised to 150° C. while distilling off the solvent, and the temperature was maintained at a reduced pressure of 30 Torr for 1 hour to obtain a comparative silicone-modified novolac resin (e). Furthermore, a powdered resin was prepared under the same conditions as in Example 1, and its properties were measured. The measurement results were as shown in Table 2.

Comparative Examples 9 to 12 100 parts of the novolac compound (A-2) synthesized in Production Example 2, 20 parts of the organosiloxane compound (B) used in Example 1, and Table 3 in the same type of reaction apparatus as Example 1.
After preparing the comparative solvent (C) of the type and predetermined amount as shown in to make a homogeneous solution, DB was added as the catalyst (D).
0 parts of Ul was added and an initial reaction was carried out under the conditions shown in Table 3. Thereafter, the temperature of the reaction solution was raised to 160° C. while distilling off the solvent, the pressure was reduced to 30 Torr, and the temperature was maintained at the maximum temperature shown in Table 3 for 1 hour to prepare a comparative silicone-modified novolac resin (e).

Furthermore, a powdered resin was prepared under the same conditions as in Example 1, and its properties were measured. The measurement results were as shown in Table 3.

Comparative Examples 13 to 17 In a reactor of the same type as Example I, 100 parts of the novolac compound (A-2) synthesized in Production Example 2, 20 parts of the organosiloxane compound (B) used in Example 1, and a solvent ( After charging 200 parts of n-butyl alcohol as C) to make a homogeneous solution, catalyst (d) of the type and predetermined amount shown in Table 4 was added, and an initial reaction was carried out under the conditions shown in Table 4. After that, the reaction solution was heated to 16 ml while distilling off the solvent at normal pressure.
The temperature was raised to 0'C, the pressure was reduced to 30 Torr, and the temperature was maintained for 1 hour to obtain a comparative silicone-modified novolac resin (e).

Furthermore, a powdered resin was prepared under the same conditions as in Example 1, and its properties were measured. The measurement results were as shown in Table 4.

(5) Measurement of properties using test pieces Silicone-modified Nopora prepared in Examples 1 to 20;
・Normal bending strength, wet bending strength, and wet strength retention for the powder resin obtained by adding 10 phr of hexamine to the resin (E) and the comparative silicone-modified novolak resin (e) prepared in Comparative Examples 1 to 17. The dynamic bending modulus was measured. The measurement method is as follows, and the measurement results are shown in Table 1.
~4.

■ Normal bending strength test piece preparation: Mixture; Powder resin: Alumina (“400”)
-40: 60 (vol, χ) dimensions; 20x120x
1Om/m Curing: 160°C x 20 minutes post-curing; 200° (x5Hr Apparent specific gravity, 2.55±0.02 Measurement: Tensilon type surface strength measuring machine used, Span 100, Load speed 20au/+win ■ Preparation of wet bending strength test piece: A post-hardened test piece under the same conditions as the normal bending strength was surface polished with sandpaper, then immersed in water at a pressure of 110'C for 2 hours.Measurement: Normal bending strength Same as ■Calculated from wet strength retention rate (wet bending strength/normal bending strength) x 100■
Preparation of dynamic flexural modulus test piece: A post-hardened test piece under the same conditions as the normal bending strength was cut and polished to a size of 8 x 45 x 3.5 m/m.Measurement: Rheolographic piezo manufactured by Toyo Seiki Seisakusho was used. Temperature increase rate 2° (/sin, forced vibration 10Hz, measurement temperature room temperature to 250°C (measured values entered in Tables 1 to 4 are readings at 200°C) Silicone-modified novolac resins according to Examples 1 to 20 (
Compared to the comparative silicone-modified novolak resins (e) according to Comparative Examples 1 to 17, E) has higher room temperature bending strength, wet bending strength, and wet strength retention, so it has better mechanical strength and water resistance. It was found that the properties were extremely good, and in addition, the dynamic bending modulus was small, indicating excellent flexibility.

Patent applicant: Sumitomo Durez Co., Ltd.

Claims (1)

[Scope of Claims] 1) A novolak compound obtained by reacting phenols and aldehydes, in which the content of unreacted phenols is 7.0% by weight or less and the number average molecular weight is 300 to 1200. 100 parts by weight of the compound (A), having 2 to 8 γ-glycidoxypropyl groups or/and β-(3,4-epoxycyclohexyl)ethyl groups as functional groups, and having a functional group equivalent of 300 to 5 to 80 parts by weight of the organosiloxane compound (B) having a boiling point of 8 at normal pressure.
0-200℃ alcohols, ketones, ethers,
Dissolved in a solvent (C) containing one or more selected from esters and cellosolves, imidazoles,
1 selected from organic phosphines and tertiary amines
1. A method for producing a silicone-modified novolac resin, which comprises adding a catalyst (D) containing one or more species and causing the reaction.