JPS635249B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing electrical or electronic components (herein simply referred to as electrical/electronic components) that exhibits less shrinkage and less distortion during curing. Coil or transistor, diode, IC,
Alternatively, in a method of manufacturing electric/electronic parts by sealing an element such as an LSI with a synthetic resin, an epoxy resin has conventionally been used as the synthetic resin. However, it has been thought that epoxy resins have poor stability in the cylinder of an injection molding machine because of their low temperature dependence in gelation, making it difficult to stably and continuously perform injection molding. Conventionally, therefore, an epoxy resin composition prepared by blending an epoxy resin and a phenol/novolak resin as a hardening agent with an accelerator such as a tertiary amine or imidazole was charged into a transfer spot, and after being melted, it was melted with a plunger. Electrical and electronic parts have been manufactured by sealing coils and the like using a discontinuous transfer molding method in which coils are forced into molds. However, this method has many problems, such as very low productivity, and this accelerator system causes large shrinkage during curing, causing distortion in the product. In order to improve productivity, the present inventor considered manufacturing the electric/electronic parts by injection molding,
When various compositions were tested, a composition containing a compound represented by the general formula Ar-NH-CO-N( _CH3 ) ₂ as an accelerator was found to be highly stable in the screw of an injection molding machine, and to be stable in the mold. The inventors have discovered that they can be cured quickly and have little shrinkage, and that by post-curing after molding, good electrical and electronic parts with less distortion can be obtained, leading to the completion of the present invention. That is, the present invention uses 20 to 120 parts by weight of phenolic novolak resin and the general formula

The present invention relates to a method for producing electrical/electronic parts, which comprises injection molding a composition containing 0.1 to 20 parts by weight of a compound represented by the formula (where Ar represents an aryl group). The present invention will be explained in more detail below. The epoxy resin used in the present invention is, for example, a compound having a 1,2-epoxyethyl group at its terminal, and particularly preferably a compound in which a 1,2-epoxypropyl group is bonded to an oxygen, nitrogen, or sulfur atom. Examples of such epoxy resins include polyglycidyl ethers, which can be treated with compounds having at least two free alcoholic and/or phenolic hydroxyl groups in the molecule, for example in the presence of an alkali or an acid catalyst and then with an alkali. The ether obtained by reacting with epichlorohydrin or glycerol dichlorohydrin is ethylene glycol, diethylene glycol, triethylene glycol, higher polyoxyethylene glycol, propane-1,2-diol, polyoxypropylene glycol, propane-1,3. -Diol, butane-1,4-diol, polyoxybutylene glycol, pentane-1,5-diol, hexane-1,6-diol, hexane-
2.4.6-triol, glycerol, 1.
Acyclic alcohols such as 1,1-trimethylolpropane, pentaerythritol, poly(epichlorohydrin): resorcitol, quinitol, bis(4-hydroxycyclohexyl)-methane, 2,2-bis(4- Alicyclic alcohols such as hydroxycyclohexyl)propane, 1,1-bis(hydroxymethyl)cyclohexene-3; N,N-bis(2-hydroxyethyl)aniline, 4,4'-bis(2-hydroxyethylamino) ) It can be obtained from alcohols with aromatic nuclei such as diphenylmethane. Alternatively, mononuclear phenols such as resorcinol, hydroquino, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)sulfone, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A
polynuclear phenols such as 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, aldehydes and phenols such as formaldehyde, acetaldehyde, chloral, furfuraldehyde, 4-chloro It can also be obtained from novolaks obtained from phenols such as phenol, 2-methylphenol, and 4-tertiarybutylphenol. Among the poly(N-glycidyl) compounds are, for example, epichlorohydrin and aniline, n-butylamine, bis(4-aminophenyl)methane,
Amines containing at least two amino hydrogen atoms such as bis(4-methylaminophenyl)methane, triglycidyl isocyanurate, and cyclic ureas such as ethylene urea, 1,3-propylene urea, 5,5-dimethyl Also included are those obtained by dihydrochlorination with reaction products of hydantoins, such as hydantoins, with N·N'-diglylycidyl derivatives. Examples of poly(S-glycidyl) compounds include:
Examples include di-S-glycidyl derivatives of dithiols such as ethane-1.2-dithiol and bis(4-mercaptoethyl phenyl) ether. Also included are polyglycidyl esters obtained by reacting a compound having two or more carboxyl groups in one molecule with epichlorohydrin or glycerol dichlorohydrin in the presence of an alkali. Such polyglycidyl esters are
oxalic acid, acetic acid, glutaric acid, adipic acid, pinelic acid, suberic acid,
Aliphatic polycarboxylic acids such as azelaic acid, sebacic acid, dimerized or trimerized linoleic acid; alicyclic acids such as tetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, hexahydrophthalic acid, 4-methylhexahydrophthalic acid Formula polycarboxylic acid;
It can be obtained from aromatic carboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid. Epoxy resins in which the terminal 1,2-epoxide groups are bonded to various hetero elements can also be used. Examples of these include N.N.O-triglycidyl derivatives of p-aminophenol or glycidyl ether-glycidyl esters of salicylic acid or phenolphthalein. You may use a mixture of epoxy resins. In the present invention, novolak glycidyl ether obtained by reacting phenol or cresol with formaldehyde is particularly preferred since it has good heat resistance as an electric/electronic component. The epoxy equivalent is preferably 100-300. Next, the phenol-novolac resin referred to in the present invention is produced by combining phenol, alkyl-substituted phenol, such as o-cresol, p-cresol, t-butylphenol, cumylphenol, vinylphenol, and formaldehyde. It is obtained by condensation in the presence of a catalyst, and among these, those with 2 to 5 nuclei and a softening point of about 50 to 140°C are preferred. Next, the general formula Ar-NH- used in the present invention is
Urea derivatives represented by CO-N(CH ₃ ) ₂ (Ar is a substituted or unsubstituted aryl group) are:
It is thought that it acts as a curing accelerator, and this formulation makes injection molding possible. As such urea derivatives, for example, the following compounds are used. (1) (However, X ₁ and X ₂ are hydrogen, halogen, lower alkyl group, lower alkoxy group, or nitro group, and they may be the same or different. Compounds corresponding to this include, for example,
3-phenyl-1,1-dimethylurea, 3-
(p-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1
-dimethylurea, 3-(o-methylphenyl)
-1,1-dimethylurea, 3-(p-methylphenyl)-1,1-dimethylurea, 3-(methoxyphenyl)-1,1-dimethylurea,
Examples include 3-(nitrophenyl)-1,1-dimethylurea. (2) (However, Y and Z are hydrogen, halogen, or lower alkyl groups, and they may be the same or different.) Compounds that correspond to this include, for example, 1,1'-phenylenebis(3,3-dimethylurea). , 1,1'-(4-methyl-m-phenylene)-bis(3,3-dimethylurea), and the like. (3) (Four) (However, p is an integer from 0 to 5.) (5) The blending ratio of the composition is 20 to 120 parts of phenolic novolak resin to 100 parts by weight of epoxy resin.
Parts by weight are used, preferably 40 to 100 parts by weight. At this blending amount, sufficient curing is achieved, and even if it is more or less, curing will not be sufficient. Further, the urea derivative is used in an amount of 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight. If it is less than 0.1 part by weight, the curing accelerating effect will be poor, and if it exceeds 20 parts by weight, curing will proceed too rapidly, resulting in large shrinkage of the molded product and making the molded product brittle. In addition, additives commonly used in epoxy resin molding materials can also be incorporated as optional components in the injection molding composition. For example, about 50 to 900 parts by weight of a filler such as mica, asbestos short fibers, calcium carbonate, alumina, silica, talc, glass fiber or aluminum hydroxide, and about 0.1 to 900 parts by weight of a mold release agent such as carnauba wax or stearic acid. 10 parts by weight, about 0.01 to 5 parts by weight of a coloring agent such as carbon black, or an appropriate amount of a flame retardant such as antimony oxide or halogenated polyhydric phenol such as tetrabromobisphenol A. The components in the composition are mixed, for example, by kneading at a temperature of about 80 to 120°C using rolls such as two rolls, a twin screw extruder, etc., and then cooling and pulverizing. After dry blending in a tumbler mixer at room temperature, the mixture may be compression molded into pellets or granules to facilitate feeding into an injection molding device. As the injection molding device, a known device for thermosetting resin can be used. Since the composition of the present invention is a thermosetting type, it is necessary to use a long press that allows the curing reaction to proceed in a heating cylinder, and on the other hand, it is necessary to increase the molding cycle by making curing in the mold as fast as possible. The temperature inside the cylinder or cylinder head is 60 to 120℃, and the mold temperature is 120 to 120℃.
The temperature is preferably 200°C. Regarding the mold, use a mold according to the shape of the intended electrical/electronic component. Furthermore, when sealing a coil or element, the object to be sealed is set in a mold in advance. Hardening in a mold is done to the extent that it can be taken out into the desired shape. The temperature is 120~200℃ as mentioned above.
The curing time is approximately 20 seconds to 3 minutes. Further, the molded product taken out from the mold is usually post-cured in an oven at a temperature of 100 to 200°C for about 2 to 10 hours to completely cure it. As a result, electrical and
Electronic components can be obtained. As described above, the present invention is a method for manufacturing electrical/electronic parts that has significantly improved productivity and less shrinkage, cracks, distortion, etc. than conventional transfer molding manufacturing methods. Examples will be explained below. Parts refer to parts by weight. Example 1 The following composition was sufficiently kneaded and mixed using two rolls at a temperature of 90 to 100°C (5 minutes), cooled, and ground into granules to obtain a molding material. EOCN-102S (Nippon Kayaku, O-cresol novolac epoxy resin, epoxy equivalent 210-240)
100 _parts OTM-007 (Showa Union, phenolic novolac resin, softening point 85-95℃ 60 parts _{( CH3} ) ₂ NCONH・_C6H5・_CH2・_C6H5・
NHCON (CH ₃ ) ₂ 5.54 parts Fuzurex RD-8 (Tatsumori Co., Ltd., fused silica)
300 parts BREN (Nippon Kayaku, brominated borax epoxy resin, epoxy equivalent 270-300) 23.5 parts Sb ₂ O ₃ 4.8 parts stearic acid 2 parts carbon black 1 part It was molded under the following conditions with a clamping pressure of 100t). Cylinder head temperature 80℃ Screw rotation speed 37r.pm Injection pressure 400Kg/cm ² Injection speed 7.3cm/sec Mold temperature 170℃ Mold holding time* 50sec *Supports the molding cycle. The molded product was then post-cured at 160°C for 8 hours to create a test piece based on JISK6911. Example 2 A test piece having the following composition was prepared under the same conditions as in Example 1. EOCN-102S 100 parts OTM-007 60 parts CH ₃ /CH ₆ H ₅ /NHCON (CH ₃ ) ₂ 6.0 parts Fuselex RD-8 300 parts BREN 23.5 parts Sb ₂ O ₃ 4.8 parts Stearic acid 2 parts Carbon black 1 part Comparison Example 1 EOCN-102S 100 parts OTM-007 60 parts 2-methylimidazoleazine complex 3 parts Fuselex RD-8 300 parts BREN 23.5 parts Sb ₂ O ₃ 4.8 parts Stearic acid 2 parts Carbon black 1 part Injection molding was attempted under the same conditions as in Example 1, but the viscosity of the resin increased significantly within the injection molding machine, making continuous molding difficult. Therefore, transfer molding (manufactured by Matsuda Kikai, mold clamping pressure 50t) was performed under the following conditions. Plunger pressure 70Kg/cm ^2Plunger descending speed 3cm/sec Mold temperature 170℃ Mold holding time* 180sec *Supports molding cycle. The molded product was then post-cured at 160°C for 8 hours to prepare a test piece. The physical properties of the test pieces obtained in Examples 1 and 2 and Comparative Example 1 were measured, and the results are shown in Table 1. Measurements were conducted based on JISK6911. however,
The glass transition temperature was determined by linear expansion coefficient measurement method.

【table】

[Table] From the above results, it can be seen that the parts of the present invention have less curing shrinkage than the conventionally manufactured products, and have the same physical performance. Example 3 The composition used in Example 1 was used to seal the rotor coil of a flat motor. FIG. 1 is a cross-sectional elevational view for explaining the sealed state. Rotor coil 1 (0.45mmφ copper wire,
3mm thick) into mold 3 (radius approx. 100mm),
Sealing was performed by injecting and curing resin (composition) 4. Injection molding machines use Thermosetter (mold clamping pressure) manufactured by each machine.
100t), and the molding conditions were as follows. Barrel head temperature 80℃ Screw rotation speed 37r.pm Injection pressure 300Kg/cm ² Injection speed 7.3cm/sec Mold temperature 170℃ Mold holding time 50sec As a result, the permeability of the resin 4 into the rotor coil 2 is also good. It was confirmed that sufficient sealing was possible without problems such as damage to the rotor coil 2 or warping due to molding distortion of the molded product. Example 4 Using the composition used in Example 1, a diode simulant shape was sealed by the method shown in FIG. That is, the resin (composition) is passed from the spool 13 of the molding machine to the runner 14 into a cylindrical diode-simulating mold 12 of 50 pieces, each having a diameter of 3 mm and a length of 7 mm, through which a 0.5 mm diameter tin-plated copper wire 11 is passed. 4
was injected and sealed. The injection molding machine was the same as in Example 3, and the molding conditions were as follows. Barrel head temperature 85℃ Screw rotation speed 37r.pm Injection pressure 200Kg/cm ^2Mold temperature 175℃ Mold holding time 30sec As a result, the flowability of the resin is also extremely good.
It was confirmed that multi-piece molding of such minute parts is fully possible.

[Brief explanation of the drawing]

The drawings are for explaining embodiments of the present invention, and FIG. 1 is a cross-sectional elevational view showing a rotor coil in a sealed state. FIG. 2 is an explanatory diagram illustrating a method of sealing a diode simulated object. 1... Rotor coil, 2... Brush, 3... Mold, 4... Resin, 11... Copper wire, 12... Mold,
13...Spool, 14...Runner.

Claims (1)

[Claims] 1 For 100 parts by weight of epoxy resin, 20 to 120 parts by weight of phenolic novolak resin and general formula
An electrical and electronic device characterized by injection molding a composition containing 0.1 to 20 parts by weight of a urea derivative represented by ArNHCON(CH ₃ ) ₂ (Ar represents a substituted or unsubstituted aryl group). Method of manufacturing electronic components.