JPH06344368A - Method of testing heat deterioration of molding and method of testing performance of molding machine - Google Patents

Abstract

PURPOSE:To provide a method for testing the heat deterioration of moldings, which enables the hue of the moldings to be inspected at a molding step and the degree of the heat deterioration to be immediately judged, and a method for testing the performance of a molding machine. CONSTITUTION:A method for testing the heat deterioration of plastics moldings at the time of the injection molding of a thermoplastic resin material is the one that measures the degree of material degradation by heat, which may be caused when a molten resin passes through resin passages sages in a molding machine and in a mold, on the basis of changes in the hue of the mol-dings. Furthermore, a material which is a coloring material included in an organic pigments or an organic dye to be added to a thermoplastic resin material and whose color tone is changed by high-temperature treatment, is added to the thermoplastic resin material, and the resin material thus prepared is molded, whereby the thermal history of the resultant moldings is inspected on the basis of the hue of the moldings. On the other hand, by changing a point of view, the performance of the molding machine can also be judged from the result of this inspection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for testing thermal deterioration of a molded product made of a thermoplastic resin material and a method for testing the performance of a molding machine for molding the molded product.

[0002]

2. Description of the Related Art Conventionally, the thermal deterioration test method for a thermoplastic resin molded product by injection molding or the like is to actually measure the strength of the molded product, or to measure the molecular weight of the molded product or the intrinsic viscosity corresponding thereto. It was a destructive inspection method.

[0003]

When the mechanical strength of a molded product is actually measured by the conventional heat deterioration test method for a molded product, the measurement may be difficult depending on the shape of the molded product. Therefore, there is a drawback that it takes time and labor.

Further, when measuring the molecular weight or intrinsic viscosity of a molded product, it takes a lot of time even for one measurement using a special measuring instrument, so that the deterioration state of the molded product can be judged immediately. There is a drawback that you cannot do it.

Therefore, a technical object of the present invention is to provide a thermal deterioration test method for a molded product and a performance test method for a molding machine, which can inspect the hue of the molded product at the molding stage and immediately judge the degree of thermal deterioration. To do.

[0006]

According to the present invention, when molding a thermoplastic resin material, when the molten resin passes through the resin passage in the molding machine and the mold, the degree of deterioration caused by heat is molded. A heat deterioration test method for a molded product is obtained, which is characterized by measuring from a hue change of the product.

According to the present invention, at least one of organic pigments and organic dyes added to the thermoplastic resin material, which is a coloring material whose hue changes by high temperature treatment, is added to the thermoplastic resin molding material. A heat deterioration test method for a molded article is obtained, which is characterized by performing a molding process and inspecting the thermal history of the molded article according to the hue of the molded article.

According to the present invention, in the heat deterioration test method for a thermoplastic resin molded product, the heat deterioration test method for a molded product is obtained, wherein the coloring material is a quinacridone pigment.

According to the present invention, when molding a thermoplastic resin material, when the molten resin passes through the resin passage in the molding machine and the mold, the degree of deterioration of the material due to heat is measured from the hue change of the molded product. Then, a performance test method for a molding machine is obtained, which is characterized in that the performance of the molding machine is judged according to the degree of deterioration.

According to the present invention, at least one kind of organic pigments and organic dyes added to the thermoplastic resin material, the material of which hue changes by high temperature treatment, is added to the thermoplastic resin molding material. A molding machine performance test method is characterized in that molding is performed by a molding machine, the thermal history of the molded article is measured by the hue change of the molded article, and the performance of the molding machine is judged according to the thermal history. To be

According to the present invention, in the performance testing method for the molding machine, there is obtained the performance testing method for the molding machine, wherein the coloring material is a quinacridone pigment.

The thermoplastic resin usable in the present invention is polybutylene terephthalate (PB).
T) resin can be exemplified, but in addition, polyethylene terephthalate (PET), nylon 6, nylon 6,6,
Polycarbonate and polyarylate can also be used, but any substance can be used as long as it can be colored with a coloring material.

Further, in the present invention, as the molding machine,
An injection molding machine can be exemplified, but it can be applied to an extrusion molding machine or a compression molding machine in addition to the above, and the type is not limited as long as it is a molding machine that molds while applying heat.

[0014]

In the present invention, when molding the thermoplastic resin,
A pigment or dye whose hue changes according to heat history is mixed with a molding material and used as a coloring material. Therefore, just by looking at the hue of the molded product, it is possible to judge the degree of heat deterioration and whether or not the product was produced under appropriate molding conditions. can do. Also, the performance of the molding machine can be judged according to the degree of thermal deterioration of the molded product.

[0015]

EXAMPLES Examples of the present invention will be described below.

Molding of polybutylene terephthalate (PBT) resin will be described as an example of the present invention.

The PBT resin has a white natural color, and several kinds of colorants having different thermal stability are added to this resin to prepare a coloring material. When molding thermoplastic resin material,
When the molding conditions such as resin temperature and injection speed are changed, the actual melting temperature is often much higher than the set resin temperature due to shearing heat generation in the molding machine.

Here, as a flow path through which the thermoplastic resin material passes during the molding process, it is heated and kneaded in a cylinder (heating cylinder) of an injection molding device for a certain period of time and then injected from a nozzle.
It passes through the mold sprue and runner, flows from the gate into the product cavity, and is cooled. The contents of the heat history of the resin here are considered to be as follows.

First, the resin is heated in a cylinder for a certain period of time to be in a molten state, and at the same time, is kneaded by screw rotation, so that the resin is also subjected to shearing heat generation and is heated at a temperature higher than the set temperature of the cylinder. become. The heat treatment at this time has a relatively large heat history, but when it is injected at a higher speed, the resin may receive shear heat generation and become a high temperature state even when passing through a nozzle or a gate. This point is also considered to be included in the thermal history.

In the case of the following example, when the molding condition is changed by using the coloring material, the hue of the molded product is compared with that of the sample product having the heat history, and the molded product is thermally deteriorated. It is possible to determine whether or not the condition is appropriate.

Example 1 As the pigment used, a pink pigment represented by the following chemical formula 1: quinacridone pink (melting point 140 °) was used.

[0022]

[Chemical 1]

As an addition method and an experimental method, 0.1% of the pigment is externally added to the material pellets before the molding is started,
Molding was performed by changing molding conditions such as filling speed.

As a comparative material, a thermally stable blue pigment "shine blue" was similarly added and molded.

A thick-walled test piece was formed from these materials,
As a result of cutting the molded product and observing the inside, the quinacridone pink-added sample showed a purple to white discoloration inside the molded product under the high-speed filling condition where shearing heat generation was extremely large at the gate. A part was observed, and no similar discolored part was observed in the similar molded product in which the filling speed was slowed.

On the other hand, with respect to the Shine Blue-added sample used for comparison, even if the filling speed condition was changed,
No change was observed in the colored state inside the molded product. Since quinacridone pink tends to decompose and decolorize around 300 ° C, in comparison with the molding resin temperature (250 ° C to 270 ° C) set from the discolored state of the high-speed filling product, actually, a considerably high heat history is observed. I know that I received it.

On the other hand, from a different point of view, since the thermal history of the molded product as a result of the molding machine is known, the performance of the molding machine can be judged.

[0028]

As described above, according to the present invention, a molding material added with a coloring pigment having poor thermal stability is molded under various molding conditions, and the hue of the molded product is investigated. , It is possible to judge the heat history of the material when melted and the deterioration status of the molded product.

Further, although it depends on the shape of the molded product, if there is a portion where the hue is partially different in one molded product, it is possible to investigate that the portion is thermally deteriorated.

Claims (6)

[Claims] 1. When molding a thermoplastic resin material, when a molten resin passes through a resin passage in a molding machine and a mold, the degree of deterioration caused by heat is measured from a hue change of a molded product. Test method for heat deterioration of molded products. 2. A coloring material of at least one kind selected from organic pigments and organic dyes added to a thermoplastic resin material, the material of which a hue changes by high temperature treatment is added to a thermoplastic resin molding material and molded. A heat deterioration test method for a molded article, which comprises inspecting the thermal history of the molded article according to the hue of the molded article. 3. The heat deterioration test method for a thermoplastic resin molded article according to claim 2, wherein the coloring material is a quinacridone pigment. 4. When molding a thermoplastic resin material, the degree of deterioration of the material due to heat when the molten resin passes through the resin passage in the molding machine and the mold is measured from the hue change of the molded product, and the deterioration is measured. A performance test method for a molding machine, characterized in that the performance of the molding machine is judged according to the degree. 5. A thermoplastic resin molding material containing at least one kind of coloring material selected from organic pigments and organic dyes, the hue of which is changed by high temperature treatment, is added to the thermoplastic resin molding material. A method for testing the performance of a molding machine, which comprises performing a molding process, measuring a thermal history of the molded article by a hue change of the molded article, and determining the performance of the molding machine according to the thermal history. 6. The performance test method for a molding machine according to claim 5, wherein the coloring material is a quinacridone pigment.