JPS61108642A - Sintered synthetic resin - Google Patents

Abstract

PURPOSE:To provide the titled resin having high strength even at a low density and excellent durability and suitable for use as an ink roll, etc., by pressure molding a row resin powder obtd. by blending a sublimable material powder with a synthetic resin powder and optionally a synthetic resin powder at ordinary temp. and sintering the resulting molding. CONSTITUTION:The cavity of a pressure molding machine 1 is filled with a predetermined quantity of a synthetic resin powder 5 such as nylon resin, and a die 2 is moved upward to form a cavity, which is then filled with a predetermined quantity of a synthetic resin powder 6 obtd. by blending a sublimable material powder (e.g. naphthalene) with the above-described synthetic resin powder. If desired, only the powder 6 may be fed. The powder is pressed at room temp. under a pressure of 100kg/cm<2> by means of an upper punch 4 and a lower punch 3 to obtain a compacted powder molding 9 composed of the synthetic resin layer 7 and the sublimable material-contg. synthetic resin layer 8. The molding is taken out of the molding machine 1 and sintered to evaporate the sublimable material thus obtaining the titled sintered resin having a high strength even at a low density.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a synthetic resin porous body, and in particular is formed by sintering a compacted body obtained by compacting synthetic resin powder at a predetermined temperature. Related to synthetic resin sintered bodies.

(Prior art) Recently, synthetic resin porous bodies formed by compacting nylon, polyethylene, and other various synthetic resin powders at room temperature and sintering the compacted compacts at a predetermined temperature have been developed. Sintered resin bodies are used in a wide variety of applications, including filters, ink rolls, writing instruments, and stamp materials.

In conventional synthetic resin sintered bodies, synthetic resin powder alone or synthetic resin powder mixed with inorganic powder as a reinforcing material is used as the raw resin powder, and the raw resin powder is filled into a mold and then pressed with a constant pressure. A powder compact is first formed, and then the powder compact is heated to a temperature slightly lower than the melting point of the base synthetic resin and sintered.

(Problems to be Solved by the Invention) The conventional synthetic resin sintered body formed as described above has the following problems:
It has the disadvantage that it is not possible to obtain a material with low density and high strength.

In other words, when forming a synthetic resin sintered body, increasing the pressure during powder compaction to obtain high strength will inevitably result in a high-density sintered body, and conversely, increasing the pressure during powder compaction to obtain high strength will inevitably result in a high-density sintered body, and vice versa. If the pressure during powder compaction is lowered, a sintered body with lower strength will inevitably be obtained.

This means that, for example, when considering the use of synthetic resin sintered bodies as ink rolls or stamp materials, high-density sintered bodies hold less ink and are more likely to run out of ink, while increasing the amount of ink held. Therefore, if the density is low, the strength will decrease and the durability of the product will be poor, meaning that a product with excellent durability and ink retention cannot be obtained.

As a means to solve the above-mentioned drawbacks, it has been considered to form a sintered body with two layers of high density and low density, and use the high density layer as a printing surface and the low density layer as an ink holding layer. Two-layer molding using a molding method as shown in FIG. 2 has been attempted.

That is, as shown in FIG. 2(a), after filling a predetermined raw material resin powder 10 into the cavity formed by the die 2 and lower punch 3 of the powder compacting machine 1, as shown in FIG. 2(b), First, a high-density green compact layer 11 is formed by pressing with high pressure using the upper punch 4, and then, as shown in FIG. Then, as shown in FIG. 3(d), the powder is pressed with a low pressure by the upper bunch 4 to form a low-density green compact layer 12.

The powder compact 13 consisting of two layers, the high-density layer 11 and the low-density layer 12, formed by the method described above is taken out from the compact and sintered by a conventional method to form two layers of high-density and low-density layers. A sintered body is obtained.

However, the above-mentioned molding method requires two rounds of powder compaction, which reduces productivity, and furthermore, the adhesion between the high-density layer and the low-density layer is poor, making it easy to cause peeling, making it impractical. It was something.

In view of the current situation as described above, the present invention has been developed to provide a multi-layered synthetic resin sintered material that has high strength not only at high density but also at low density, and which has appropriate density differences depending on the application. It was invented for the purpose of providing unity.

(Means for Solving the Problems) That is, the present invention involves compacting raw resin powder, which is a mixture of synthetic resin powder and sublimable substance powder, at room temperature, and then sintering the compacted product at a predetermined temperature. It is a synthetic resin sintered body characterized by being formed by tying the resin together, and more details are as described below based on Examples.

(Example) Example 1゜A raw resin powder was obtained by blending 5% by weight of naphthalene into a synthetic resin powder made by blending 10% by weight of nylon 6 with nylon 66, and the raw resin powder was heated to room temperature under a pressure of 21,000 kg/cm'. Press to form powder.

Subsequently, the powder compact was sintered at 260°C for 60 minutes to obtain a density of 0.80. Radial crushing strength 2,5 kg/11119
A sintered body of No. 2 was obtained.

Example 2 A synthetic resin powder in which 10% by weight of nylon 6 was blended with nylon 66 was used as the first raw resin powder, and a synthetic resin powder in which 7% by weight of naphthalene powder was blended with the first raw resin powder was used as the first raw resin powder. First, raw resin powders No. 2 were prepared, and then the two raw resin powders were compacted by a two-layer, one-time pressing method as shown in FIG.

As shown in FIG. 1A, first, a predetermined amount of the prepared first raw resin powder 5 is filled into the cavity of the powder compacting machine 1, and then, as shown in FIG. 1B, After moving the die 2 upward to form a cavity, a predetermined amount of second raw resin powder 6 is further filled onto the first raw resin powder 5,
Subsequently, as shown in the same figure (C), the upper punch 4 and the lower bunch 3 are pressed from both the upper and lower directions at room temperature with a pressure of about 1000 kg/Ql12, and the pressure composed of the nylon resin E7 and the nylon resin layer 8 containing a sublimable substance is pressed. A powder compact 9 is obtained.

Next, the powder compact was taken out from the molding machine 1 and
Perform 60 minutes of sintering to form a dense layer with a density of 0.87 and a dense layer with a density of ff.
A two-layer sintered body consisting of a low-density layer of 0.0 and 78 was obtained.

(Function) First, when a sublimable substance is blended into the synthetic resin powder, a sintered body with a relatively low density can be obtained even if compaction is performed at extremely high pressure as shown in Example 1, and the formed sintered body The radial crushing strength of the compact is high.

In other words, in the case of nylon resin powder alone, 1000
When compacting is performed at a high pressure of about kg/cm2, the density is 0.
．． Whereas a high-density sintered body with a density of about 87 is formed, a relatively low-density sintered body with a density of 0.80 is formed by blending the sublimable material 3'1 of the present invention, and furthermore, with regard to this strength, In order to obtain a sintered body with a density of about 0.80 using nylon resin powder alone, the pressure during compaction must be 600 kg/cm'.
The radial crushing strength is 1.8 kg.
/mm2, whereas if a sublimable substance is added, powder compaction can be performed at a high pressure of 1000 kg/cm2, so the radial crushing strength of the obtained sintered body is about 2.5 kg/cm2.
It is as high as mm2.

In addition, as shown in Example 2, by utilizing the principle that a low-density sintered body can be obtained by blending a sublimable substance with a synthetic resin powder, a single multi-layer structure was created in which synthetic resin powders with different blending amounts of a sublimable substance were appropriately combined. By molding, it is possible to form a multilayer sintered body with density differences depending on the application with high productivity, and the formed sintered body not only does not cause peeling but also has high strength. There is.

In the above implementation, the case where nylon resin was used was shown, but
The present invention is applicable to all types of synthetic resin sintered bodies, including not only thermoplastic resins but also thermosetting resins, due to its principle of construction.

(Effects) As is clear from the above description, the present invention makes it possible to provide a synthetic resin sintered body having any density and high strength depending on its use.

Therefore, by taking advantage of the above-mentioned properties, for example, we can create high-performance ink rolls and printing materials that were thought to be impossible with conventional technologies, which have a low density, a large amount of ink, and are strong and durable. It becomes possible to provide

Further, by forming a multilayer sintered body having different densities, it becomes possible to provide a synthetic resin sintered body that is more suitable for the intended use.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a conventional example. 1...Powder compacting machine, 5...Synthetic resin single powder, 6.
...Synthetic resin powder containing sublimable substances.

Claims (1)

[Claims] A synthetic resin sintered body, characterized in that it is formed by compacting raw resin powder, which is a mixture of synthetic resin powder and powder of a sublimable substance, at room temperature, and sintering the compacted compact at a predetermined temperature. .