JPH0480940B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a melamine resin molding composition suitable for molding electrical equipment parts such as earth leakage breakers and arc boxes, particularly for injection molding. More specifically, in molding methods such as injection molding and transfer molding, a specific amount of pulp and a specific The present invention relates to a melamine resin molding composition containing a specific amount and type of clay together with a melamine resin. Traditionally, melamine-based resins have excellent heat resistance, solvent resistance, abrasion resistance, and electrical insulation properties, so they have been used for cosmetics in tableware such as plates, bowls, trays, desks, chests of drawers, and exposed boxes. Plates and connectors, converters,
It is molded and used in various fields such as electrical equipment parts such as wiring boards and insulating insulators. In the field of electrical equipment parts mentioned above, excellent arc resistance that prevents arc generation is required from the viewpoints of electrical insulation and durability. As is well known, melamine resin itself has arc resistance, but it does not meet recent high safety standards such as the Electrical Appliance and Material Control Law and UL standards. In order to improve this arc resistance, various proposals have been made to incorporate silica, talc, asbestos, etc. into melamine resin as fillers. If the filler is blended with the melamine resin, arc resistance can be improved to a certain extent commensurate with the performance of the filler, but it is not possible to improve the arc resistance to a certain extent that satisfies recent advanced safety standards.
I can't get anything with high performance over 180 seconds. On the other hand, the blending of the filler may reduce the moldability, which is essential for a molding composition, and may cause cracks in the molded product, defective products with a shape different from the desired shape, or, in general, Melamine-based resin for electrical equipment parts that simultaneously satisfies a high degree of arc resistance and moldability, as problems such as tearing within the mold are increasing as the shape of the desired electrical equipment parts becomes more complex. It has been extremely difficult to obtain a molding composition, particularly a melamine resin molding composition for injection molding. Mechanical strength (for example, bending strength) is required for molded products such as dishes, but there is a problem in that the mechanical strength inevitably decreases depending on the blending of the filler. The present inventors have conducted extensive research into melamine-based resin molding compositions that provide molded products that exhibit excellent performance such as high arc resistance, moldability, and bending strength, and are suitable for molding electrical equipment parts. As a result, we unexpectedly discovered that these problems could be solved all at once by blending a specific amount of pulp, specific amount, and specific type of clay with melamine resin, and completed the present invention. This is what I came to do. That is, the present invention uses 20 to 80 parts by weight of pulp and SiO ₂ to 100 parts by weight of melamine resin.
The weight ratio of Al ₂ O ₃ is 1:1 to 3:1 and the oil absorption is
The present invention provides a melamine resin molding composition, characterized in that it contains 20 to 130 parts by weight of 40 to 95 clay. Other objects and advantages of the present invention will become more apparent from the following description. The melamine resin used in the present invention refers to a resin containing 60% by weight, preferably 70% by weight or more of a resin (in terms of solid content) obtained by adding and condensing melamine with aldehydes such as formaldehyde, acetaldehyde, and furfural. These resins include melamine resin from only melamine and aldehydes;
Guanamines such as benzoguanamine, acetoguanamine, CUT guanamine, phenols such as phenol, xylenol, gresol, resolnol, bisphenol A, ureas such as urea, thiourea, ethylene urea, which can be condensed with melamine; Melamine cocondensation resin with compounds such as epoxy compounds and polyester compounds;
A blend resin of a melamine resin and a melamine co-condensed resin; and a melamine resin or a melamine co-condensed resin, such as a guanamine resin, a phenol resin, a urea resin, an alexid resin, an epoxy compound resin, a polyester compound resin, etc. Examples include blend resins with other resins. In the above melamine resin, the amount of resin added and condensed with melamine and aldehydes is 60% by weight.
If it is less than this, the arc resistance deteriorates, which is not preferable. Further, as the aldehyde, formaldehyde is preferably used due to ease of reaction, etc. Furthermore, due to crack resistance in melamine resin, the molar ratio of the reaction between melamine and formaldehyde is 1 to 1 to 1 mole of melamine. 2.5 mol is preferred, and 1 to 2 mol is particularly preferred. As mentioned above, the melamine resin used in the present invention is appropriately used as a melamine resin, a melamine co-condensed resin, a blend resin of a melamine resin and a melamine co-condensed resin, or a blend resin of a melamine resin and various resins. However, as the melamine co-condensation resin, a co-condensation resin of melamine and a phenol, preferably a co-condensation resin of melamine, phenol and formaldehyde, which is reacted under conditions that produce a resol type phenolic resin, can be particularly preferably used. . As the blend resin, novolak type phenolic resin, resol type phenolic resin, and resin obtained by mixing these resins by reacting phenol and formaldehyde can be particularly preferably used. The above-mentioned phenolic resin in the present invention refers to a resin obtained by adding and condensing the above-mentioned phenols with the above-mentioned aldehydes (in terms of solid content) at 60% by weight or more, preferably 70% by weight or more, particularly preferably 80% by weight or more. Refers to resin containing; phenolic resin consisting only of phenols and aldehydes, phenolic co-condensation resin with a compound capable of co-condensing with phenols, blend resin of phenolic resin and phenol co-condensing resin, phenolic resin or phenol It includes blend resins of similar co-condensation resins and resins such as urea resins and polyester resins. When using these phenolic resins,
In addition to the performance of moldability and bending strength, the melamine resin molding composition further improves insert resistance and dimensional stability, so preferably the phenolic resin is contained in an amount of 5 to 30% by weight, particularly preferably. is preferably used as a melamine resin containing 10 to 25% by weight. The pulp referred to in the present invention is usually used as a raw material for paper, chemical fibers, cellulose plastics, etc.
It refers to a chain polymer whose main component is α-cellulose obtained from cellulose raw materials, and in general, cardboard-like fibers made from cellulose raw materials treated with wood and linter are used industrially. The blending amount of the pulp depends on the mechanical strength of the molded product, etc.
20 for 100 parts by weight of melamine resin
~80 parts by weight are required. If the amount of pulp is less than 20% by weight, the bending strength will particularly decrease, and if it exceeds 80 parts by weight, the moldability will deteriorate, which is undesirable, and preferably 30 to 60 parts by weight per 100 parts by weight of melamine resin. can be used. Furthermore, in the melamine resin molding composition according to the present invention, the weight ratio of SiO ₂ and Al ₂ O ₃ is 1:1 to 1:1.
It is necessary to mix 20 to 130 parts by weight of clay with a ratio of 3:1 and an oil absorption amount (ASTM, D281-31 compliant method) of 40 to 95 per 100 parts by weight of the melamine resin. Clay is generally referred to as clay, clay, china clay, etc., and has a chemical composition of SiO ₂ and Al ₂ O ₃ as main components, preferably 80% by weight or more, more preferably 90% by weight or more, but the above-mentioned When blending a clay that satisfies the following conditions, it is possible to obtain a melamine resin molding composition that exhibits excellent performance in arc resistance, moldability, and bending strength. I don't know why, but the weight ratio of SiO ₂ and Al ₂ O ₃ is 1:1 to 3:1.
Even if the oil absorption is 40 to 95, if it is less than 20 parts by weight based on 100 parts by weight of melamine resin, it will be difficult to obtain a high degree of arc resistance, and if it exceeds 130 parts by weight, the desired bending strength will not be achieved. Since it is difficult to obtain, it is preferable to use 25 to 70 parts by weight. Further, the weight ratio of SiO ₂ and Al ₂ O ₃ is preferably 1:1 to 2:1, and 1:1 to 1.5:
1 is more preferable. More preferably, as described below, by the method of ASTM D 1208-65, at 1000°C for 20
Clays with a loss on ignition of 2% by weight or less, particularly preferably 1% by weight or less when ignited for 1 minute, are suitable for use in molded products of various electrical equipment parts in terms of arc resistance, formability, and bending strength. It is possible to obtain an excellent high-performance product with suitable shock absorbing properties. Regarding oil absorption, it is difficult to obtain the desired bending strength with oil absorption of less than 40, and preferably oil absorption of 45 to 75 can be used. Conventionally, it was believed that adding fillers such as silica, tackle, and asbestos improves arc resistance to a certain extent, but on the other hand, it reduces formability and bending strength. The synergistic effect of the clay was completely unexpected. Clays that can be particularly preferably used in the present invention include, for example, Icecap Icecap K and B-80 manufactured by Burgess Victor Co. (USA), Hydyite grade 10 manufactured by Georgia Kaolin Co. (USA), etc. PX, PXS, R, etc., RC-32 clay made by Thiel Kaolin Co. (USA); Made by Engelhard Minerals and Chemicals Co. (USA)
Satintone grade No. 1, No. 2, No. 5, etc., RC grade 8, 9, etc. manufactured by Georgia Kaolin Co., Ltd. (USA), etc., manufactured by G.M.
Examples include Polyfil grade, etc.
There is no problem in using these materials alone or in combination of two or more. As a method for producing the melamine resin molding composition of the present invention, known methods such as the so-called wet method and dry method described below can be used. For example, for 1 mole of so-called melamine crystal powder, melamine resin, pulp, and clay containing powder or granules can be produced by a method known per se such as a carbide method or a urea method. A melamine resin liquid obtained by reacting a 36% concentration of foralin with an aqueous solution of foralin and/or paraformaldehyde in a proportion of 1 to 2.5 moles of formaldehyde in an aqueous medium at a pH of about 7 to about 9, and phenol 1 in an aqueous medium in a proportion of 0.7 to 3 mol of formaldehyde, for example in the form of a 30% concentration aqueous formalin solution and/or paraformaldehyde,
A so-called resol type phenolic resin liquid is a mixture of a predetermined amount of a resol type phenolic resin liquid obtained by reaction at a pH of about 7 to about 9, for example, a melamine resin liquid with a resin solid content concentration of about 40 to about 60% by weight. For example, 30 to 60 parts by weight is added to the melamine resin syrup based on 100 parts by weight of the resin solid content of the melamine resin syrup.
Parts by weight of pulp and 25 to 70 parts by weight of the clay according to the present invention are added, and other additives are added as desired, and the mixture is kneaded using a kneading means such as a kneader or a co-kneader, for example, at a temperature of about 70°C to about 100°C. Dry at temperature,
For example, so-called popcorn having a diameter of about 3 cm to about 0.5 cm is obtained. Examples include powder-treated popcorn products obtained by adding additives such as pigments, lubricants, and curing catalysts to the popcorn thus obtained. The powder treatment can be carried out using means such as a ball mill, an impact hammer mill, a vibration mill, or a tower mill. If desired, the material may be pre-pulverized, for example, using an impact hammer mill, and then further pulverized using means such as a ball mill, vibration mill, or tower mill. Examples of the above additives include titanium oxide, zinc oxide, zinc sulfide, red iron oxide, navy blue, barium sulfate, iron black, ultramarine, carbon black, Ritobon, titanium yellow, cobalt blue, Hansa yellow, benzidine yellow, and lake red. , aniline black, dioxazine violet, quinacridone red, quinacridone violet, naphthol yellow, phthalocyanine blue, phthalocyanine green, etc.; zinc stearate, zinc myristate, aluminum stearate, calcium stearate, Butyl stearate, stearyl stearate, dioctyl phthalate, diptylphthalate, stearamide, ε-caprolactam, oleic acid amide, linoleic acid amide,
Lubricants such as polyethylene glycol, stearyl alcohol, polyoxyethylene stearate, glycerin, polyethylene glycol monooleate, montan acid wax, montan acid ester, cyclohexyl stearate, low polymers of ethylene trifluorochloride, etc.; phthalic anhydride , p-toluenesulfonic acid, dimethyl oxalate, dibenzyl oxalate, dimethyl phthalate, benzoyl peroxide, epichlorohydrin, p-toluenesulfonic acid triethanolamine salt, 2-aminoethylsulfonic acid, dimethylaniline sulfonic acid hydrochloride, sulfonic acid Examples of curing catalysts include melamine acid, ammonium chloride, ammonium phosphate, trimethyl phosphate, acetamide, oxamide, hexamine, calcium hydroxide, magnesium hydroxide, and the like. The powdered product obtained as described above is preferably re-pulverized by heating and kneading the preforming composition in an extruder, heated roll machine, etc., and then molded by injection molding, transfer molding, etc. It is preferable to use it as a melamine-based resin molding composition having a particle size range suitable for the method. As an example of a method for drying the melamine resin molding composition according to the present invention, the melamine resin syrup as described above may be dried in a spray dryer, a thin film dryer,
If necessary, per 100 parts by weight of powdered melamine resin obtained by drying with a drying means such as a drum dryer or vacuum dryer, or powdered melamine resin obtained by blending powdered resins. For example, pulp and clay in the amounts described above, which have been subjected to powder treatment in advance, and appropriate amounts of pigments, lubricants,
Examples include powdered products in which a curing catalyst is added and mixed using a mixing means such as a Henschel mixer, ribbon blender, V-type blender, or spar mixer. Further, in the dry method as well as the wet method, commercially available raw materials such as melamine resins and phenol resins can be used as desired. It is preferable that the powdered products obtained by the wet method and the dry method be used as a preforming composition as described above, re-pulverized, and used as a memine resin molding composition. In the above heating kneading,
There are no particular limitations on the extruder, and any appropriately selected extruder can be used, such as a single-screw extruder, a twin-screw extruder, and the like. The compression ratio and temperature can be selected as appropriate, for example, a compression ratio of 1.1 to 3,
Temperature conditions such as about 50 to about 130°C can be exemplified. The extrusion end of the extruder may be of any type, such as an open type or a screen-like die type, and the twin-screw extruder may be of either a twin-screw type in the same direction or a twin-screw type in opposite directions. Further, the type of heating roll machine can be selected as appropriate. The re-pulverization treatment of the preforming composition obtained by heating and kneading can be carried out using any re-pulverization means that can form a re-pulverized product. If desired, sieving means can be used in combination. Examples of the crusher used for such re-grinding include impact crushers, hammer mills, atomizers, pin mills, roll mills, pulpizers, and the like. The thus obtained re-ground product preferably has a viscosity that allows it to pass through a 10-mesh JIS sieve and not pass through a 100-mesh sieve, for ease of molding.
The content is 80% by weight or more, more preferably 85% by weight or more, and the heating kneading conditions are 80 to 120°C and 10 to 30% by weight.
The second one is good because it exhibits outstanding performance as a melamine resin molding composition. The melamine resin composition also exhibits excellent automatic metering suitability. The following test methods were used to measure arc resistance, formability, bending strength, insert resistance, dimensional stability, oil absorption, and ignition loss. Arc resistance measurement method: A disk-shaped test piece with a diameter of 100 mm and a thickness of 3 mm is injection molded under the following molding conditions. Mold temperature: Fixed side 175℃, movable side 175℃ Cylinder temperature: Front 90℃, rear 70℃ Injection pressure: 900Kg/cm ² Using the test piece thus obtained, JIS K-6911 item (5-15) It is expressed in arc resistance time (seconds) using the method described in . Formability measurement method: Coil bobbin type molded product (dimensions, 25φ x 30
mm) is injection molded under the following molding conditions. Mold temperature: Fixed side 175℃, movable side 175℃ Cylinder temperature: Front 90℃, rear 70℃ Injection pressure: 900Kg/cm ² Molding time (seconds): 20, 30, 40, 50, 60, 70,
80, 90, 100 Under the above nine molding time conditions, 5 to 10 shots are molded under one molding time condition, and when 5 shots of good quality are obtained in a row, the condition is passed. do. The moldability was thus evaluated as follows. However, if a part of the molded product is torn off in the mold during molding, or if the molded product is deformed or cracks occur, it will be considered a defective product. ◎ Passed under all conditions (9 types) ○ Passed under 5 to 8 conditions △ Passed under 2 to 4 conditions × Fail under all conditions or passed only one condition Bending strength measurement method Test piece for measuring bending strength (dimensions, 100 mm ×10mm
x 4 mm) using the method described in section (5.17) of JIS K-6911 under the following molding conditions. Mold temperature: Fixed side 175℃, movable side 175℃ Cylinder temperature: Front 90℃, rear 70℃ Injection pressure: 900Kg/cm ² Molding time (seconds): 60 seconds For measuring bending strength obtained under the above conditions Using the testing machine described in section (5.17.1), calculate the bending strength (Kg·f/cm ² ) of the test piece using the method described in the same section. Insert resistance measurement method Brass knurling (dimensions, outer diameter 40φ x inner diameter
20φ x thickness 10mm) on the outer periphery of the same thickness.
A 52φ resin molded ring was assembled as a test piece under the following injection molding conditions. Mold temperature: Fixed side 175℃, movable side 175℃ Cylinder temperature: Front 90℃, rear 70℃ Injection pressure: 900Kg/cm ² Molding time (seconds): 65 seconds Ten test pieces were tested and dried with hot air. by machine
Heat at 100°C for 25 minutes, then cool with cold water for 5 minutes to complete one cycle. The presence or absence of cracks was observed using this method, and the insert resistance was determined by calculating the average number of cycles in which cracks occurred. Dimensional stability measurement method A test piece was prepared by injection molding according to the method described in JIS K-6911 (5 and 7), and the heat shrinkage rate was 110°C and the processing time was 168 hours. The heat shrinkage rate (%) was calculated using the formula of RS168, the molding shrinkage rate (%) was added to this, and the dimensional stability (%) was determined by adding both values. Method for measuring oil absorption: Accurately weigh approximately 1 g of clay and place it on a glass plate according to the measurement method of ASTM D281-31. Separately, accurately weigh the dropping bottle filled with linseed oil in advance, and slowly add the linseed oil drop by drop from the dropping bottle to the clay. After each drop, rub the clay and linseed oil with a thin spatula. Mix well. A very hard putty-like paste is formed. To prevent the state from collapsing or separating,
The end point is the final amount of linseed oil that can be mixed. Next, accurately weigh the linseed oil used, and from the weights of the linseed oil and clay used in the test, determine the oil absorption amount by the number of pounds of linseed oil that will make a paste of 100 pounds at the final point. Loss on ignition Approximately 5 g of the sample is dried at 110° C. for 2 hours according to the measurement method of ASTM D 1208-65. Accurately weigh 1 g of the dried sample, place it in a porcelain crucible that has reached a constant weight, ignite it at 1000°C for 20 minutes, cool it in a desiccator, and weigh it. Next, ignite it again at 1000℃ for 10 minutes and check the weight loss. The loss on ignition is calculated using the following formula. Loss on ignition (weight %) = Loss on ignition (g)/Sample weight (g) x 100 The present invention will be described in more detail below with reference to Reference Examples, Examples, and Comparative Examples. Reference example 1 Preparation of melamine resin Melamine (manufactured by Yuka Melamine Co., Ltd., Yuka Melamine)
Put 800 g, 850 g of a 37% concentration formalin aqueous solution, and 380 g of water into a flask with a reflux condenser,
The reaction was heated at 90° C. with stirring under the condition of F/M=1.7. When the cloudy point of the melamine resin liquid reached 60℃, 1.2g of NaOH was added to terminate the reaction. (This is the temperature at which cloudiness occurs when adding 45 ml of hot water, stirring, and cooling.) The melamine resin liquid thus obtained was spray-dried using a spray dryer to obtain a melamine resin. Reference Example 2 Preparation of novolac type phenolic resin 130 g of phenol, 13 ml of water, 92.4 g of a 37% formalin aqueous solution and 1 g of oxalic acid dihydrate are added, and stirred and refluxed for 30 minutes under the condition of F/P = 0.83. Subsequently, 1 g of oxalic acid dihydrate was further added, and stirring and refluxing were continued for 1 hour. Next, add 400 ml of water, cool, and let stand for 30 minutes to allow the resin to settle, and remove the upper water layer by suctioning with a siphon. after that,
The resin was dehydrated under reduced pressure of 100 mm of mercury until the temperature reached 120°C, poured into a stainless steel pot while hot, and cooled and crushed to obtain a novolak type phenolic resin. Reference example 3 Preparation of resol type phenolic resin 94 g of phenol, 37% formalin aqueous solution
Add 123 g of barium hydroxide octahydrate and 4.7 g of barium hydroxide octahydrate, and react with stirring at 80°C for 2 hours under the condition of F/P = 1.5. Next, add 10% sulfuric acid to adjust the pH to 7.
A resol type phenolic resin was obtained by dehydration under reduced pressure of 50 mm of mercury at a temperature not exceeding 70°C. Reference example 4 Preparation of melamine/phenol co-condensation resin liquid Add 340 g of phenol, 278 g of 37% formalin aqueous solution and 4.2 g of potassium hydroxide, E/P
Stir at 80°C for 30 minutes under the condition of =0.95, then cool to 45°C. Next, 900 g of melamine, 942 g of a 37% formalin aqueous solution, 190 g of water and oxalic acid.
After stirring at 85℃ for 60 minutes under the condition of F/M = 1.63, 0.3g of potassium hydroxide was added to terminate the reaction, and the mixture was cooled to 50℃. A melamine/phenol cocondensation resin liquid of % by weight was obtained. Examples 1 to 9 20 to 80 parts of powder pulp shown in the column of Table 1 was added to 100 parts by weight of the melamine resin obtained in Reference Example 1.
Parts by weight, clay in the amount shown in the column of Table 1 [SiO ₂ /Al ₂ O ₃ = 1.2; total of SiO ₂ and Al ₂ O ₃ 96.5% by weight, oil absorption 50, loss on ignition 09% by weight; Engel Manufactured by Hard Milanel & Chemical Co., Ltd., product name
Satinone No. 2] 20 to 130 parts by weight and 1 part by weight of zinc stearate as a mold release agent were added and mixed and pulverized using a Henschel mixer. Next, the plate-shaped preforming composition was heated and kneaded at 100°C for 20 seconds using an extruder with a compression ratio of 1.5, and then re-pulverized using an impact crusher.
A melamine resin molding composition containing 85% by weight of materials that did not pass through the mesh was obtained which could be re-pulverized. Examples 10 to 14 70 to 95% by weight of the melamine resin obtained in Reference Example 1 and shown in the column of Table 1, and 5 to 30% by weight of the novolac type phenolic resin in the amount shown in the column of Reference Example 2. % of powdered pulp in the amount shown in the column 1 of Table 1 for 100 parts by weight of melamine resin.
60 parts by weight, 25 to 40 parts by weight of clay in the amount shown in the column of Table 1 (same as used in Examples 1 to 9), 1 part by weight of zinc stearate as a mold release agent, and other additions. Adding 1 part by weight of hexamine as an agent, the following steps were carried out in the same manner as in Examples 1 to 9: mixing and pulverizing.
A melamine-based resin molding composition was obtained by heating, kneading, and re-pulverizing. Examples 15 to 16 In Example 15, the resol type phenolic resin obtained in Reference Example 3 was added to the melamine resin liquid whose reaction had been terminated to a cloudy point of 60°C in Reference Example 1 as shown in the column of Table 1. In Example 16, about 75% by weight of the melamine resin obtained in Reference Example 4 and about 25% by weight of the phenolic resin were used. Melamine-phenol co-condensation resin liquid is used as melamine-based resin, and these melamine-based resin components
For 100 parts by weight, 45 parts by weight of pulp in the amount shown in the column of Table 1 and 40 parts by weight of clay (same as that used in Examples 1 to 9) in the amount shown in the column of Table 1 of the mixture, mix thoroughly with a kneader,
Next, it was dried at 90°C with a band dryer to obtain popcorn. Furthermore, 1 part by weight of zinc stearate was added to the popcorn per 100 parts by weight of the melamine resin component.
Parts by weight were added and mixed and ground using a ball mill. The thus obtained powdered product was then heated and kneaded and re-pulverized in the same manner as in Examples 1 to 9 to obtain a melamine resin molding composition. Table 1 shows the results of measuring the arc resistance, molding die, bending strength, insert resistance, and dimensional stability of the melamine resin molding compositions according to the present invention in Examples 1 to 16 above using the measurement method described above. It is shown in the column of Comparative Examples 1 to 8 A melamine resin comprising the melamine resin obtained in Reference Example 1 in the amount shown in the column of Table 1 and the novolak type phenolic resin obtained in Reference Example 2 in the amount shown in the column of Table 1. For 100 parts by weight of resin; Powder pulp in the amount shown in the first column of Table 1; Clay in the amount shown in the first column of Table 1. However, Comparative Examples 1 to 6 were those used in Examples 1 to 9. In Comparative Example 7, the same material was used as [SiO ₂ /Al ₂ O ₃ = 1.2, total of SiO ₂ and Al ₂ O ₃ 85% by weight, oil absorption 30, loss on ignition 13.8% by weight; Engel Hard Mineral & Chemical (Company), product name
ASP400P] was used, and in Comparative Example 8, [SiO ₂ /Al ₂ O ₃ = 5.4, total of SiO ₂ and Al ₂ O ₃ 95% by weight, oil absorption 50, loss on ignition 3.8% by weight; Tsuchiya Kaolin Kogyo ( Co., Ltd., trade name NN kaolin clay] was used; further, 1 part by weight of zinc stearate and 1 part by weight of hexamine were used; Examples 1 to 9 are as follows.
In the same manner as above, a molding composition was obtained by mixing, pulverizing, heating kneading, and re-pulverizing. The various properties of the molding composition thus obtained were measured using the above-mentioned measuring method, and the results are shown in the column of Table 1. In addition, as Comparative Example 9, a molding composition was prepared in exactly the same manner as Comparative Example 1 except that no pulp was used, and various performances were tested, but the moldability and bending strength were significantly inferior, and the high performance was It could not be put to practical use in the required electrical equipment parts.

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Claims (1)

[Claims] 1. For 100 parts by weight of melamine resin, pulp
Clay containing 20 to 80 parts by weight, a weight ratio of SiO ₂ and Al ₂ O ₃ of 1:1 to 3:1, and an oil absorption of 40 to 95.
A melamine resin molding composition comprising 20 to 130 parts by weight. 2. The melamine resin molding composition according to claim 1, wherein the clay has a loss on ignition of 2% by weight or less. 3 The melamine resin is a phenolic resin 5 to 30
% by weight of the melamine resin composition according to claim 1 or 2.