JPS6317931A - Modified nylon rim material and method for molding using same - Google Patents

Abstract

PURPOSE:To obtain molded articles of modified nylon RIM material having low water absorption ratio and little change in dimension caused by water absorption, by blending nylon RIM material with bismaleimide and TREAZIN and molding the blend in a mold in a vacuum chamber. CONSTITUTION:(A) A RIM material consisting of caprolactam and an alkali main catalyst, (B) a nylon RIM material consisting of a rubber compound comprising caprolactam and a lactone type rubber compound or a polyhydric propyl alcohol as main components and a promoter, (C) bismaleimide and (D) TREAZIN are humidified, fed to a mixing head, blended and then added to a mold in a vacuum chamber to give molded articles using modified nylon RIM material.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a modified nylon RIM material used in the production of a wide variety of resin molded products in small quantities, and a molding method using the material.

Conventional technology Conventionally, urethane R was mainly used for the production of a wide variety of resin molded products in small quantities.
IM materials, epoxy RIM materials, etc. have been used, but these materials: ■ Urethane RIM materials have low heat resistance of 70'C to 80 degrees Celsius, ■ Epoxy RIM materials have poor impact properties ( 10Ky-cm/cm or less with isot and notch). For this reason, nylon RIM materials have been considered as an alternative to these materials. This Nio7 material has a flexural modulus (20000 (KP)
-/(7) or higher), impact properties (isolated, notched, 10 Kp-pieces/Cm or higher) and heat distortion temperature (1
It has a good balance with 8,6 and 513 l-7 (load, 120℃ or higher), and is liquid and has low viscosity, so the mold for molding does not need to be made of metal. It has been used to create works of art. As this nylon RIM molding for prototypes is put into practical use, techniques that can handle small-lot, wide-variety production using nylon RIM materials are being studied.

Problems to be Solved by the Invention However, in conventional nylon RIM materials, the polyamide group, which is a constituent component of the nylon RIM material, has the property of absorbing moisture, resulting in decreases in physical properties, changes in dimensions, etc. was seen.

The current water absorption rate is 20 wt% (atmospheric equilibrium), and the dimensional change rate is 0.18%. For this,
Currently, it is difficult to use nylon RIM materials in actual products, and development into commercial products has been delayed.

In view of the above problems, the present invention aims to provide a modified nylon RIM material that has a low water absorption rate and small dimensional change due to water absorption, and a molding method using the same.

Means for Solving the Problems In order to solve the above problems, the first invention uses nylon RI.
6% by weight of bismaleimide and Treazine resin in M material
The object of the present invention is to provide a modified nylon RIM material characterized by a mixture of 80% by weight or less.

The second invention includes a filler having an average aspect ratio of 5 to 15 and a filler having an average aspect ratio of 1 to 3 in a nylon RIM material mixed with 6% to 80% by weight of bismaleimide and treazine. The present invention provides a modified nylon RIM material containing 10% by weight or more and 60% by weight or less of a spherical, flake, or fibrous filler.

The third invention is a solution A of a nylon RIM material consisting of caprolactam and an alkali main catalyst, a solution B of a nylon RIM material consisting of a cocatalyst and a rubber compound whose main components are caprolactam and a lactone type rubber compound or polyhydric propyl alcohol, and a bis A modified nylon RIM material characterized by humidifying maleimide and treazine, injecting them into a mixing spatula to mix them, and then injecting them into a mold in a vacuum chamber to obtain a molded product. The present invention provides a molding method using.

Function In the present invention, bismaleimide and treacin react simultaneously in the nylon RIM material during curing.

When cured, its hydrophobic molecules transform the IPN structure into a nylon RIM.
By forming it in the material, it has the effect of lowering the water absorption rate. A filler with an average aspect ratio of 5 or more and 15 or less reduces the number of polyamides in the nylon resin,
It not only provides low water absorption but also strengthens the material. Further, a filler having an average aspect ratio of 1 or more and 3 or less reduces the nylon component, contributes to low water absorption, and acts as a filler. The mixing head serves to mix the nylon RIM material, treazine, and bismaleimide, and the vacuum chamber serves to remove air bubbles from the material being injected.

Example 6 pages/ [Example 1] Next, the present invention will be explained in more detail.

Liquid A consists of caprolactam and an alkali main catalyst; Liquid B consists of caprolactam and a rubber compound whose main components are a lactone-type rubber compound or polyhydric propyl alcohol; and a co-catalyst.
As a two-component type nylon RIM material consisting of
It was dissolved in a constant temperature bath at 0C)C, and BT resin manufactured by Mitsubishi Gas Chemical Co., Ltd. was used as bismaleimide and treazine, so that the proportions were 3.5.10.50, 70, 80, and 85% by weight. Mix with For convenience, these are listed as B1. B
2°B3. B4. B6. B6. It's called B7. Next, the above liquid mixture was poured into a mold (molding mold) at 180° C., and test pieces having different weight fractions of seven types of BT resin were prepared.

These seven types of test pieces were allowed to absorb moisture in a constant temperature and humidity environment of 23°C and 50RH, and the time taken to reach equilibrium was determined using conventional nylon RIM material (Ube Industries, Ltd., UX-B, Table 1). (denoted as Bo) are shown in Table 1.

7 b/Table 1 These results show that when the weight fraction of BT resin is from 6% to 80% by weight (B2 to B6), the time to reach equilibrium in water absorption is four times longer than in the conventional case.

It can be seen that when the BT resin is 6% by weight or less, the effect is small, and when it is 80% by weight or more, it has almost the same effect as 80% by weight.

[Example 2] In the material system of 50% by weight of bismaleimide and Treazine (Mitsubishi Gas Chemical Co., Ltd., BT Resin), an average amount of Milled fiber (Nittobo Co., Ltd. F 104) with an aspect ratio of 11 is 50.30, 20,
10.5% by weight, respectively, glass beads with an average aspect ratio of 1 (Toshiba Ballottini Corporation, 30
μ under) is 10°20.30.40.46% by weight
Mixed so that For convenience, these are C1, C2,
They are called C3, C4, and C5. These were poured into a mold to prepare a test piece. The water absorption rate was measured in the same manner as in Example 1. The results are shown in Table 2.

Table 2 From these results, it can be seen that the time for the water absorption rate to reach equilibrium is nearly four times longer than before.

Here, a filler having an average aspect ratio of 15 or more has a large fiber length, so the viscosity increases significantly and is not suitable for molding. Further, as a reinforcing material for nylon RIM material, if the average aspect ratio is 6 or less, it only functions as a filler, and the reinforcing effect is not large.

[Example 3] The master model M shown in FIG. 1 was molded, and the rubber mold 6 with 9 pages was left in a constant temperature bath at 150° C. for 3 hours to heat it. At the same time, liquid A and liquid B Oyohi BT resin of nylon RIM material (manufactured by Ube Industries, Ltd., UX-B) were heated to 100°C.
Leave it in an oil bath for 1 hour to dissolve. These A liquid, B liquid, and BT resin liquid are transferred to the tank 1 shown in FIG. Tank 2. They are poured into a tank 9, and at the same time, the tip of a static mixer 4 for mixing the three liquids is connected to the gate opening of a rubber mold 6 humidified at 50°C. Next, these are placed in a vacuum chamber 7 and then degassed through the suction port 8. After confirming that the pressure inside the vacuum chamber is 176 CIIHq, the mixing valve 3 is opened and the mixed liquid is poured into the rubber mold θ. After flowing in, the inside of the vacuum chamber is left to return to normal pressure for about 5 minutes, and the molded product 6 made of nylon RIM material, which is a replica of the master model molded in the rubber mold 6, is taken out and gates, paris, etc. are removed. Then I did some finishing touches.

This molded product was left at 23°C and 5oRH for 200 hours, and compared with a molded product made of a conventional nylon RIM material. It is shown in Table 3.

10=-.

Table 3 *See Figure 1 for a, b, and c. From these results, it was found that the dimensional change rate was less than % compared to the conventional nylon RIM material.

By this method, the molded product obtained had fewer bubbles and had an excellent appearance compared to conventional molded products.

As described above, according to the present invention, there is provided a modified nylon RIM material in which bismaleimide and treazine are mixed in a nylon RIM material in an amount of 6% by weight or more and 80% by weight or less, or a modified nylon RIM material having an average aspect ratio. is 5 or more 15
The modified nylon RIM material, which is a mixture of the following filler and a spherical, flake, or fibrous filler with an average aspect ratio of 1 or more and 3 or less, from 10% to 00% by weight, reaches equilibrium in water absorption. The effect is that the time is several times longer than the conventional method. In addition, the molded product obtained by heating the nylon RIM material A liquid, B liquid, bismaleimide, and Treazine, injecting them into the interior with a mixing head and mixing them, and then injecting them into a molding article in a vacuum chamber. The rate of dimensional change due to water absorption is less than a fraction of that of conventional products, and the appearance is excellent with fewer bubbles.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a master model, and FIG. 2 is a schematic diagram of an apparatus used in a molding method using modified nylon RIM material. 1...Nylon RIM material A liquid tank, 2.
...B liquid tank made of nylon RIM material, 3...
... 3-liquid heating valve, 4 ... Static mixer, 6 ... Molded product copied from the master model, 6 ... Rubber mold, 7 ...・Vacuum chamber, 8... Deaeration port. Name of agent: Patent attorney Toshio Nakao and 1 other artist
l figure

Claims (3)

[Claims] (1) A modified nylon RIM material made by mixing 6% by weight or more and 80% by weight or less of bismaleimide and treazine in a nylon RIM material. (2) A filler with an average aspect ratio of 5 or more and 15 or less and a spherical shape with an average aspect ratio of 1 or more and 3 or less, in a mixture of 5% by weight or more and 80% by weight or less of bismaleimide and treazine in a nylon RIM material. A modified nylon RIM material formed by mixing 10% by weight or more and 60% by weight or less of a flaky or fibrous filler. (3) Liquid A of a nylon RIM material consisting of caprolactam and an alkali main catalyst, liquid B of a nylon RIM material consisting of a cocatalyst and a rubber compound whose main components are caprolactam and a lactone type rubber compound or polyhydric propyl alcohol, bismaleimide and A molding method using a modified nylon RIM material, which comprises humidifying Treazine, injecting them into a mixing head to mix them, and then injecting them into a mold in a vacuum chamber to obtain a molded product.