JPH0557089B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a molding material for cleaning the surface facing the cavity of a mold for molding a resin molding material. Furthermore, the present invention relates to a mold cleaning method using such a molding material. [Prior art] Molding materials containing a large amount of filler, such as molding materials for sealing, have poor mold releasability, and if the number of moldings exceeds, for example, 10, the mold surface (the surface facing the mold cavity) Gas reactants from the molding material adhere to the
Mold clouding occurs, resulting in decreased moldability and surface gloss of the molded product. Conventionally, as a countermeasure against this problem, molding is stopped and the mold surface is manually cleaned, or a silicone mold release agent or the like is sprayed onto the mold after each molding. [Problems to be Solved by the Invention] In order to clean the surface of the mold facing the cavity, it is necessary to stop the molding operation, resulting in a decrease in efficiency. Spraying a mold release agent every time it is molded also complicates the work and reduces efficiency.
Another problem is that it is not possible to clean the mold or spray the mold release agent using an automated system at night. Therefore, this invention provides the following advantages by performing molding.
The first object of the present invention is to provide a mold cleaning material that can take in deposits on the surface of the mold facing the cavity. Furthermore, a second object of the present invention is to provide a mold cleaning method that can efficiently clean a mold using such a molding material. [Means for Solving the Problem] In order to solve the first problem, the mold cleaning molding material according to the present invention has a surface that faces the cavity of the mold when molded in the mold. The mold surface is cleaned by taking in the kimono, and a resin component and a filler are essential components, and a resin component in which only an amino resin and an epoxy resin are used in combination as the resin component is used, The blending ratio of the resin component and filler is such that the resin component accounts for 20 to 70 parts out of 100 parts of the total weight of both, and an organic filler and an inorganic filler are used together as the filler, and the organic filler The blending ratio of the inorganic filler and the inorganic filler is 0.1 to 1 part by weight per 1 part by weight of the organic filler. In addition, in order to solve the second problem, the mold cleaning method according to the present invention includes putting the mold cleaning molding material into the cavity of the mold and performing molding. At the same time, we try to incorporate deposits from the surface facing the cavity of the same mold. Amino resin is a resin that has enveloping properties, that is, it has the property of easily incorporating mold deposits into the molding material.Moreover, it is cheap enough to be disposable, so it is used for cleaning molds. suitable for The amino resin is not particularly limited, but urea resin, melamine resin, guanamine resin, etc. are used. By the way, in conventional amino-based resin molding materials that do not contain epoxy resin, pulp is usually used as a filler, and although pulp has good mold releasability, it tends to adhere to the mold as the number of molding increases. . Furthermore, if the molding material is a molding material that contains a large amount of inorganic filler without using much organic filler, such as a sealing material, the adhesion to the mold is particularly large. Therefore, in this invention, by using an epoxy resin in combination with an amino resin, the enveloping properties of the amino resin and the adhesiveness of the epoxy resin combine to make it easier to incorporate mold deposits into the molding material. It is. The epoxy resin used in this invention does not necessarily have so-called sticky tackiness, and tackiness comparable to that of ordinary rubber is sufficient. Examples of the epoxy resin include tacky ones such as bisphenol A type, novolac type, and glycidyl ester type. Among these, the general type bisphenol type A, which is solid, is preferred from the viewpoint of good blendability with amino resins, moldability, and mold release properties. In the case of this invention, the resin components of the mold cleaning molding material are those in which only an amino resin and an epoxy resin, which have a strong cleaning property and have a strong ability to absorb deposits on the mold surface, are used in combination, and a phenol resin, etc. Since it does not contain substances that have a low ability to absorb deposits, it has sufficient cleaning performance. The ratio of the amino resin and the epoxy resin is not particularly limited, but for 1 part by weight of the amino resin (hereinafter, "part by weight" is simply referred to as "part"),
It is preferable to use 0.2 to 2 parts of epoxy resin. If the amount is less than 0.2 parts of epoxy resin, the cleaning performance will decrease and
If the amount exceeds 100%, the mold releasability tends to decrease. In addition to amino resins and epoxy resins, fillers are also used in this invention. Fillers are also used because amino resins and epoxy resins alone have poor mold releasability and low mold release strength.
As the filler, an organic filler that contributes to mold releasability and an inorganic filler that contributes to cleanability are used in combination at an appropriate mixing ratio as described below. Examples of organic fillers include wood flour, cotton flour, and pulp, and examples of inorganic fillers include calcium carbonate, silica, talc, clay, gypsum, and aluminum hydroxide. The usage ratio of organic filler and inorganic filler is
For example, the amount of inorganic filler is 0.1 to 1 part to 1 part of organic filler. If the proportion of the inorganic filler is less than 0.1 part, the cleaning properties may be reduced, and if it exceeds 1 part, the mold releasability may be reduced. There are no particular limitations on the proportions of the amino resin, epoxy resin, and filler used, but the proportion of the resin component and filler in which only the amino resin and epoxy resin are used together is the resin component (out of 100 parts of the total weight of both). For 20 to 70 parts of amino resin + epoxy resin,
Leave the remaining 80-30 parts as filler. The total amount of amino resin and epoxy resin is less than 20 parts, and the filler is 80 parts.
If the amount is exceeded, cleaning performance may deteriorate. If the total amount of amino resin and epoxy resin exceeds 70 parts and the amount of filler is less than 30 parts, mold releasability may decrease. In addition to the amino resin, epoxy resin, and filler, the mold cleaning molding material of the present invention also contains a curing agent (an amino resin curing agent and/or
Alternatively, one or more of an epoxy resin curing agent), a mold release agent, a coloring agent, etc. may be blended.
As the mold release agent, for example, metal soap, stearic acid, wax, etc. are used to a minimum extent. The colorant is not particularly limited. These materials are mixed, kneaded, pulverized, and, if necessary, granulated to form a molding material. To clean a mold using the mold cleaning molding material of the present invention, for example, the following procedure is performed.
Ordinary molding is performed using an ordinary resin molding material (for example, a thermosetting resin molding material). When cloudiness occurs on the surface facing the mold cavity,
Alternatively, before this occurs, the mold cleaning molding material of the present invention is put into the cavity of the mold instead of the usual resin molding material, and molding is performed.
The molding material for mold cleaning may be molded only once, or may be molded several times in succession, if necessary. As a result, the deposits adhering to the surface of the mold facing the cavity are taken into the molded product. When the molded product is removed from the cavity,
The surface facing the mold cavity is thoroughly cleaned. After that, normal molding is performed, and the above-mentioned cleaning work is performed as necessary. This cleaning work can be performed in the same manner as normal molding, so it is simple and can be easily automated. Moreover, there is no need to stop the molding operation. The molding conditions for the mold cleaning molding material of this invention are not particularly limited, but for example, in the case of compression molding, the mold temperature is 140 to 155°C, and the molding pressure is 170 to 250 kg.
f/cm ² , molding time is 25 to 60 seconds, and in the case of injection molding, the mold temperature is 145 to 155℃ on the fixed side and 145 to 155℃ on the movable side.
145~155℃, cylinder temperature 80~100℃ at the front,
At the rear, the temperature is 40 to 60°C, injection time is 10 to 20 seconds, holding time is 2 to 10 seconds, screw rotation is 40 to 60 rpm, and molding time is 30 to 35 seconds. If it is below these ranges, mold deposits may not be removed; if it exceeds these ranges, seizure may occur and mold deposits may increase. Note that other molding methods and molding conditions may be employed. There is no particular limitation on the mold to be applied to the mold cleaning method of the present invention. Molds are generally made of iron with a hard chrome plating finish (more than 99% of mold materials for thermosetting resin molding materials are made of this material), but other materials (for example, It may be made of iron only and has no surface finish. [Function] Amino-based resins have a encapsulating property that allows them to easily absorb mold deposits, and this encapsulating property and the adhesiveness of the epoxy resin combine to prevent the molding from entering the mold when molding the molding material. Deposits are taken in. In addition, since the blending ratio involving the filler, that is, the blending ratio of the resin component to the filler and the blending ratio of the organic filler to the inorganic filler, are both appropriate, one of the cleaning properties and mold release properties may deteriorate. Since both cleaning and mold release properties are good, the surface facing the mold cavity can be cleaned appropriately. By molding using such a molding material, deposits on the mold can be removed, so the mold can be cleaned efficiently. [Examples] Specific examples and comparative examples of the present invention are shown below, but the present invention is not limited to the following examples. Example 1 A molding material for mold cleaning was obtained by mixing, kneading, and pulverizing materials having the following composition. Urea resin...25 parts epoxy resin (Epicoat manufactured by Ciel Chemical Co., Ltd.)
828) ...5 parts Hexamine ...0.3 parts Pulp ...60 parts Calcium carbonate ...10 parts Stearic acid ...0.5 parts Next, the following ingredients were mixed in a mixer and then kneaded using a kneader. After continuously molding the epoxy resin molding material for sealing for 3 hours, the mold became cloudy and the appearance of the molded product became poor.When molding was performed once with the above mold cleaning molding material, the mold cloudiness disappeared. It was possible to continue molding the epoxy resin molding material for sealing again.

〔Effect of the invention〕

Since the mold cleaning molding material of the present invention has the above-mentioned configuration, it has the remarkable effect of appropriately cleaning the surface facing the mold cavity. The reason why the surface of the mold facing the cavity can be appropriately cleaned is that the molding material for cleaning the mold has both good cleaning properties and mold release properties. The reason for this is that the type of resin in the resin component of the mold cleaning molding material is appropriate, and the blending ratio involving the filler is appropriate. In other words, the resin component consists only of amino-based resin and epoxy resin, which have a strong ability to absorb deposits on the mold surface and have excellent cleaning properties. ~70 parts (80 to 30 parts of filler), with an appropriate blending ratio of inorganic filler to 1 part by weight of organic filler.
It has an appropriate blending ratio of 0.1 to 1 part by weight, and has good cleaning properties and mold release properties. In the mold cleaning method according to the present invention, molding is performed using a mold cleaning molding material that has good both cleaning properties and mold release properties, and the surface facing the mold cavity is cleaned, so an appropriate cleaning method is used. Cleaning is simple and efficient, making it extremely useful.

Claims (1)

[Scope of Claims] 1. A mold cleaning molding material that cleans the mold surface by taking in deposits on the surface facing the cavity of the mold when molded in the mold, which comprises a resin component and a filler. A resin component is used in which only an amino resin and an epoxy resin are used together as the resin component, and the blending ratio of the resin component and filler is such that the resin component is 20 parts out of 100 parts of the total weight of both. It has a composition that accounts for ~70 parts, and
An organic filler and an inorganic filler are used together as the filler, and the mixing ratio of the organic filler and the inorganic filler is 1 part by weight of the organic filler to the inorganic filler.
A molding material for cleaning molds, characterized in that it contains 0.1 to 1 part by weight. 2. A molding material which is formed by putting the molding material for mold cleaning according to claim 1 into the cavity of a mold, and when molded in the mold, it captures deposits on the surface facing the cavity of the mold. Mold cleaning method.