JPH06145472A - Molding material of thermosetting resin - Google Patents

Abstract

PURPOSE:To obtain a molding material of thermosetting resin suitable for producing thin moldings, moldings of complicated shape and moldings of multi- cavity mold. CONSTITUTION:100 pts.wt. thermosetting resin composition is blended with 10-130 pts.wt. cured material of melamine resin as a filler. Moldability is improved by blending of the cured material of melamine resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin molding material used as a molding material for injection molding and the like.

[0002]

2. Description of the Related Art A thermosetting resin molding material is mainly used for molding electric / electronic parts such as a coil bobbin, a power supply case, and a micro switch. When a thermosetting resin is used as a molding material for injection molding or the like, the filler is usually an organic filler such as pulp, wood powder, cotton powder, or chemical fiber, calcium carbonate, clay, aluminum hydroxide, silicic acid. Inorganic fillers such as calcium, magnesium silicate and aluminum silicate are generally used.

[0003]

However, the electric and electronic parts such as the coil bobbin, the power supply case, and the micro switch are thin, thin, small and small recently, and due to the combination of parts, the shape is thin and the shape is complicated, and the productivity is improved. It is required to perform multi-cavity molding in order to increase the height. However, in the case of molding a large number of thin-walled and complicated-shaped molded products, the thermosetting resin molding material prepared by blending the filler as described above causes various problems in moldability and continuous molding stability. It happened. That is, studies have been made to adjust the fluidity of the molding material to improve the continuous stability and moldability of molding, but if the molding material is hard (the monohole flow described below is large for about 100 seconds or more, spiral (The flow is as small as 45 cm or less), the fluidity deteriorates and the cavity on the side closer to the sprue is filled, but the ability to fill the cavity on the far side deteriorates, and the parting line (PL) is placed around the sprue. Problems such as large burrs and lack of dimensional stability of the molded product occur. Conversely, if the molding material is softened (monohole flow described later is small and spiral flow is large) to improve fluidity, sprue Flow to the cavity far away from it, but the filling properties into the details deteriorate, and the curing slows down and the thermal rigidity of the molded product deteriorates. That.

The present invention has been made in view of the above points, and an object of the present invention is to provide a thermosetting resin molding material suitable for molding a molded product having a thin wall, a complicated shape, and a large number of pieces. is there.

[0005]

A thermosetting resin molding material according to the present invention comprises 100 parts by weight of a thermosetting resin composition and 10 to 120 parts by weight of a cured melamine resin as a filler. It is characterized by. Further, in the present invention, the cured melamine resin has a DSC curing degree of 60 to 1
It is preferably 100% and has an average particle diameter of 20 to 130 μm.

The present invention will be described in detail below. As the melamine resin cured product, a product obtained by crushing a melamine resin molded product can be used, and it is preferable to use a discarded product such as a defective product or burr that appears in the molding process for recycling waste plastics. . The cured melamine resin preferably has a DSC curing degree of 60 to 100%. DSC (Differential Sc)
The anning calorimeter: a scanning differential calorimeter) changes the temperature of the sample and the reference substance (alumina, etc.) at a constant rate, and changes the energy input ΔQ to the two.
Is a device adapted to measure as a function of temperature T,
As one of the thermal analysis methods, it is possible to quantify the amount of absorption and heat generation of a substance with a DSC curve more accurately than with DTA. The exothermic peak of the DSC curve becomes smaller as the degree of cure of the resin increases, and the exothermic peak disappears when completely cured. Therefore, the exothermic amount of the exothermic peak of the cured product is divided by the exothermic amount of the exothermic peak of the uncured resin. The DSC degree of cure can be determined as a percentage of the value obtained by subtracting from 1. When the DSC degree of curing of the melamine resin curing agent is less than 60%, the melamine may react with the thermosetting resin more than acting as a filler and may lower the fluidity. Further, the cured melamine resin has an average particle size of 20 to
It is preferable that the particles have a size of 130 μm. When the average particle size of the cured melamine resin is less than 20 μm, it becomes difficult to handle because it becomes close to powder and automatic metering becomes difficult, and when the average particle size exceeds 130 μm, the particles become too large and the mold gate There is a risk that it will not be possible to feed the molding material into the cavity due to clogging.

As the base thermosetting resin, any one of phenol resin, epoxy resin, unsaturated polyester resin and the like can be used. In addition to this thermosetting resin, inorganic fillers such as alumina, silica, calcium carbonate, talc, clay, barium sulfate and aluminum hydroxide, hardening aids such as calcium hydroxide and magnesium hydroxide, zinc stearate, magnesium stearate. , A release agent such as carnauba wax, a pigment, a flame retardant, a modifier and the like are mixed to prepare a thermosetting resin composition, and the melamine resin cured product is added to the thermosetting resin composition. By blending as a filler, the thermosetting resin molding material according to the present invention can be prepared. The blending amount of the cured melamine resin is set in the range of 10 to 130 parts by weight with respect to 100 parts by weight of the thermosetting resin composition. Mixing amount of cured melamine resin is 1
If the amount is less than 0 part by weight, the effect of enhancing the moldability cannot be sufficiently obtained by blending the cured melamine resin as a filler. If the amount of the cured melamine resin compounded exceeds 130 parts by weight, the amount of the filler will be excessive and the fluidity will decrease,
On the contrary, the moldability deteriorates. The thermosetting resin molding material prepared as described above is used for molding such as injection molding.

[0008]

The invention will now be illustrated by the examples. (Example 1) Novolak type phenolic resin composition 100
In parts by weight, the degree of DSC cure is 60% and the average particle size is 20μ.
A phenol resin molding material was prepared by blending 10 parts by weight of the powder of the melamine resin cured product of m.

(Examples 2 and 3) As a melamine resin cured product, one having a DSC curing degree and an average particle diameter shown in Table 1 was used, and the compounded amount shown in Table 1 was added to the novolac type phenol resin composition. A phenolic resin molding material was prepared. (Example 4) 100 parts by weight of unsaturated polyester resin molding material was mixed with 100 parts by weight of powdered material of cured melamine resin having a DSC degree of cure and an average particle diameter shown in Table 1,
An unsaturated polyester resin molding material was prepared.

(Example 5) 100 parts by weight of an epoxy resin composition was mixed with 100 parts by weight of powdered melamine resin having a DSC degree of curing and an average particle size shown in Table 1, and
An epoxy resin molding material was prepared. (Comparative Example 1) A phenol resin molding material was prepared without blending a melamine resin cured product.

Comparative Example 2 A melamine resin cured product having a DSC curing degree and an average particle size shown in Table 2 was blended in a novolak type phenol resin composition in an amount of 120 parts by weight to prepare a phenol resin. A molding material was prepared. (Comparative Example 3) Instead of a melamine resin cured product, a phenol resin cured product having a DSC curing degree and an average particle size shown in Table 2 was used as a filler, and this was used with respect to 100 parts by weight of the novolac type phenol resin composition. A phenol resin molding material was prepared by mixing 60 parts by weight.

In the above Examples 1-5 and Comparative Examples 1-3
Flow of thermosetting resin molding materials prepared by
And spiral flow were measured. Measurement of monohole flow
Use an extrusion tester to select a mold with a mono hole.
Put 40g of sample and heat to 120 ± 2 ℃
62 kg / cm²50mmφ plunger with molding pressure
The sample in the mold by pushing the sample out of the monohole.
This is done by measuring the time when the charges run out.
It was The spiral flow measurement is EMMI1-60.
In accordance with the standard, 6g of sample, mold temperature 150 ℃, molding pressure
Force 90kg / cm ², Transfer completed in 90 seconds
The shape flowed into the spiral flow mold
This was done by measuring the length of the molded product. result
Are shown in Tables 1 and 2.

Using these thermosetting resin molding materials, a pressing pressure of 150 tons, a cylinder temperature of 80 ° C. at the front,
Rear 60 ° C, mold temperature fixed side 180-190 ° C, movable side 175-185 ° C, injection pressure gauge 130 kg / c
A coil bobbin was injection molded under the conditions of m ² , screw rotation speed 45 rpm, injection time 5 seconds, curing time 20 seconds, and gate side gate. The moldability during this molding was evaluated, and the results are shown in Tables 1 and 2.

[0014]

[Table 1]

[0015]

[Table 2]

In Tables 1 and 2, the "continuity" of moldability is a measurement of whether or not molding is possible continuously, and the one in which molding is stopped by cylinder curing in 1 hour of continuous molding is "x". “A” was evaluated when the molding was stopped for 1 hour or more and less than 8 hours, and “◯” was evaluated when the molding was continuously performed for 8 hours or more. The "fillability" of the moldability was evaluated by observing the fillability of the pin press-fitting portion of the coil bobbin. Although all of the examples were good, all of the cavities of Comparative Examples 1 and 3 were filled in all the cavities, but the filling property of the details was poor, and a deficiency was generated. In addition, for molding thermosetting resin, it is necessary to always provide an air vent in the mold to release air and curing reaction gas in the cavity, but if the burr of the air vent is not released every time in continuous shots, the air vent The effect of degassing from is lost, and gas remains in the molded product resulting in lack of thickness. The moldability "burr releasability" is a measure of whether or not burrs are released from this air vent. "○" means that the burrs are released every time, and "sometimes" does not. “Fair” was evaluated, and those that were not released were evaluated as “x”. "Uniformity of burr"
Is a circle that is evenly burred in each cavity.
Those having variations in burrs generated in "each cavity" were evaluated as "x".

As can be seen in Table 1 of each example and Table 2 of each comparative example, a cured melamine resin was used as a filler in an amount of 10 to 10.
It is confirmed that the moldability of each of the examples compounded in the range of 130 parts by weight is improved.

[0018]

As described above, according to the present invention, 100 parts by weight of the thermosetting resin composition is mixed with 10 to 130 parts by weight of the cured melamine resin as a filler, so that the composition of the cured melamine resin is molded. It is possible to improve the moldability, and to mold a thin-walled, complicated shape, multi-cavity molded product with good moldability.

[Procedure amendment]

[Submission date] March 8, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

[0003]

However, the electric and electronic parts such as the coil bobbin, the power supply case, and the micro switch are thin, thin, small and small recently, and due to the combination of parts, the shape is thin and the shape is complicated, and the productivity is improved. It is required to perform multi-cavity molding in order to increase the height. However, in the case of molding a large number of thin-walled and complicated-shaped molded products, the thermosetting resin molding material prepared by blending the filler as described above causes various problems in moldability and continuous molding stability. It happened. That is, studies have been conducted to adjust the fluidity of the molding material to improve the continuous stability and moldability of molding, but if the molding material is made to have a low flow (a monohole flow described later will be about 100 seconds or more. Large, the spiral flow is small to about 45 cm or less), the fluidity deteriorates and the cavity on the side closer to the sprue is filled, but the cavity on the far side is less filled, and the parting line around the sprue ( (PL) causes a large amount of burrs and lacks in dimensional stability of the molded product. On the contrary, the molding material has a high flow (a monohole flow described later is small and spiral flow is large). If it is improved, the flow from the sprue to the distant cavity will deteriorate, but the filling properties into the details will deteriorate, and the curing will slow down and the thermal rigidity of the molded product will decrease. It is intended to.

Claims (2)

[Claims] 1. A thermosetting resin molding material comprising 100 parts by weight of a thermosetting resin composition and 10 to 120 parts by weight of a cured melamine resin as a filler. 2. The cured melamine resin has a DSC curing degree of 6.
0 to 100% with an average particle size of 20 to 130
The thermosetting resin molding material according to claim 1, wherein the thermosetting resin molding material has a thickness of μm.