JP3328424B2 - Mold cleaning resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for cleaning a mold surface of an automatic molding machine in the automatic molding of a curable resin molding material. The present invention relates to a resin composition for cleaning a mold that exhibits a mold cleaning effect.

[0002]

2. Description of the Related Art Conventionally, molding of an encapsulated molded product such as an integrated circuit (hereinafter abbreviated as IC / LSI) using a curable resin such as an epoxy resin is performed by transfer molding several hundred molded products at a time. In general, a large tablet-shaped molding material was used and manually molded using a large mold of several hundred pieces.

However, if molding is continued for a long time, the inner surface of the mold becomes dirty. If the molding is continued continuously, the surface of the molded product becomes dirty, or the molded product adheres to the mold and the molding operation cannot be continued. There were many. Therefore, it is necessary to periodically clean the mold, and a method has been proposed in which the mold cleaning resin is molded at a rate of several shots every several hundred shots of the molding material.

[0004] For example, Japanese Patent Publication No. 52-788 discloses that "stain on a mold surface during molding of a curable resin molding material (excluding an amino resin molding material) is molded with a material mainly composed of an amino resin. By doing so, a "cleaning method" is proposed, amino-based resin, organic substrate and / or inorganic substrate,
A mold cleaning resin composition comprising a release agent is disclosed. JP-B-64-10162 discloses a resin composition for cleaning a mold, comprising a co-condensation resin of an amino resin and a phenol resin and a mineral powder having a new Mohs hardness of 6 to 15.

[0005] These resin compositions for mold cleaning are often used in the form of tablets having the same size as the molding material, and are pre-heated so that the internal temperature of the tablets is 90 ° C to 110 ° C, and then molded. Thus, the entire surface of the mold is filled, and the surface of the mold is cleaned by taking in stains on the surface of the mold during curing.

[0006] In recent years, in response to a demand for unmanned and clean molding, an automatic curable resin molding machine has been developed, and automation of molding has been widely performed. This automatic molding machine
ICs and LSIs are molded in small molds that take several to several tens of pieces.
A molding method is employed in which molding is performed while being preheated in a pot, and then a series of steps of automatically removing a molded product are automatically repeated.

On the other hand, high integration and thinning of IC / LSI, etc.
Along with the surface mounting, the shapes and structures of molded products have been diversified, and combinations of molding temperature conditions and molding times optimal for various types of molded products have also been diversified. An automatic molding machine is characterized in that the set molding conditions are repeatedly and efficiently molded by unmanned operation, and interruption of the molding and changing of the conditions are problems that must be avoided as much as possible.

[Problems to be solved by the invention]

[0008] Under such circumstances, it is extremely difficult to stop the automatic molding machine in order to carry out the mold cleaning operation and reset the molding conditions of the resin composition for mold cleaning to carry out the mold cleaning operation. It is rational and uneconomical, and it has become necessary to carry out a mold cleaning operation by molding the cleaning resin mini-tablet under the same molding conditions as the molding curable resin mini-tablet.

Therefore, it is possible to convert a conventionally known resin composition for cleaning a mold into a mini-tablet as described in Japanese Patent Publication No. 52-788 and use it for cleaning a mold in an automatic molding machine. Generally done. However, in these resin compositions for mold cleaning, since the composition is generally determined for the purpose of improving the moldability and shortening the cleaning work time when preheating a large tablet, an automatic molding machine called mini tablet no preheating molding is used. Under specific conditions, the molding range that shows good mold cleaning effect is limited, and when performing cleaning work under molding conditions where cleaning effect is insufficient, it is necessary to increase the number of cleaning shots to respond Did not get.

For example, when a resin composition for mold cleaning as exemplified in Japanese Patent Publication No. 52-788 is mini-tablet and used for mold cleaning, curing is too slow and molding conditions at low temperature are required. As a result, swelling of the cleaning resin occurred, and the resin could not be used for cleaning the mold during low-temperature automatic molding.

When a resin composition for mold cleaning exemplified in JP-B-64-10162 is used in the form of mini-tablets, the curing is too fast and the molding conditions of the curable resin are relatively low. Although it has a cleaning effect, under the conditions of high-temperature automatic molding, even if the number of shots is twice as large as that of a normal case, the mold of the automatic molding machine cannot be suitably cleaned.

In terms of workability and economy, it is not possible to use a resin composition for cleaning a mold which shows a suitable cleaning effect for each of a variety of molding conditions corresponding to a variety of molded articles. In addition, there has been a demand for a resin composition for mold cleaning that exhibits a suitable mold cleaning effect under a wide range of molding conditions in a cleaning operation of a mold of an automatic molding machine.

The inventors of the present invention have conducted research to solve the above-mentioned problems. As a result, it was found that the curing behavior in a curast meter is closely related to a preferable cleaning range of the cleaning resin composition, and that the curing speed in a specific range is determined. It has been found that the cleaning resin composition exhibits a suitable mold cleaning effect over a wide range of molding conditions,
The present invention has been completed.

[0014]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above problems, and is characterized in that a dirt on a mold surface is removed during automatic molding of a curable resin molding material. In the composition, the curing rate in the curast meter was 2 at the T90 value at the mold surface temperature of 145 ° C.
The present invention relates to a resin composition for cleaning a mold, which is 80 seconds to 420 seconds.

Hereinafter, the present invention will be described in detail.

In the present invention, the resin composition refers to a melamine resin, a melamine-phenol co-condensate or a melamine-urea co-condensate, and the melamine-phenol co-condensate includes triazines such as melamine, phenol, and the like. Melamine-urea co-condensation resin is obtained by co-condensation of triazines such as melamine, ureas, and aldehydes.

The melamine resin is obtained by condensing a triazine such as melamine and an aldehyde, and the urea resin is obtained by condensing a urea with an aldehyde. As the above triazines, besides melamine, based on 100% by weight of the triazines,
For example, triazines other than melamine such as benzoguanidine and acetoguanamine may be contained in an amount of 30% by weight or less.

The above-mentioned phenols also include, in addition to phenol, 100% by weight of the phenol.
For example, phenols other than phenols such as cresol, xylenol, ethylphenol and butylphenol may be contained in an amount of 30% by weight or less. Further, the above-mentioned aldehydes may contain, in addition to formaldehyde, for example, formaldehydes such as paraform and acetaldehyde.

Further, the resin composition used in the present invention can be blended with other resins which can be blended therewith in an amount which does not adversely affect the above-mentioned improved properties of the composition of the present invention. . Examples of such a resin include an alkyd resin, a polyester resin, an acrylic resin, an epoxy resin, and rubbers.

The resin composition for cleaning a mold of the present invention contains a mineral powder in addition to the resin described above. For example, natural materials such as corundum, emery, garnet, and silica and silicon, iron, titanium, sodium, calcium, magnesium, aluminum, chromium, oxides or carbides such as boron are preferable, and as these compounds, silicon oxide, Examples thereof include magnesium oxide, aluminum oxide, silicon carbide, and boron carbide.

The particle size of the mineral powder is not particularly limited, but is generally from # 10 to # 8000, preferably from # 10 to # 8000.
50 to 4000, more preferably # 100 to # 2000
It is good. If the particle size is smaller than # 8000, the cleaning effect is deteriorated, dusts are generated during handling, and the working environment is likely to be deteriorated. If the particle size is larger than # 10, defects such as damage to the mold and uneven cleaning are caused. Tends to occur.

The amount of the mineral powder used is not particularly limited, but the resin composition 1 for cleaning a mold according to the present invention.
The amount is 10 parts by weight to 90 parts by weight, preferably 10 parts by weight to 30 parts by weight, more preferably 17 parts by weight to 29 parts by weight with respect to 00 parts by weight.

The composition of the present invention contains, in addition to the above-mentioned mineral powder, other inorganic or organic fillers, coloring agents, curing catalysts,
Other additives such as lubricants, antioxidants and the like may be included.
Examples of such additives include, for example, pulp, wood flour, vinylon fiber, glass powder, glass fiber, untreated calcium carbonate, talc, aluminum hydroxide, barium sulfate, other inorganic or organic fillers such as zinc sulfide. Agents; for example, inorganic pigments such as titanium oxide, carbon black, zinc white, cadmium yellow, and red iron; organic pigments such as phthalocyanine, azo, and diazo; Coloring agents such as anthraquinone-based, indico-based, and azo-based dyes; for example, organic acids such as phthalic anhydride, oxalic acid, sulfamic acid, and paratoluenesulfonic acid; inorganic acids such as hydrochloric acid and sulfuric acid; these acids and triethylamine; Triethanolamine, β-dimethylaminoethanol, 2-methyl-2-amino-1 Such curing catalyst salts with propanol and the like; for example calcium stearate, zinc stearate, stearamide, methylol stearamide,
Lubricants such as methylenebisstearamide, paratoluenesulfonic acid amide, cetyl alcohol, paraffin, silicone oil; for example, naphthylamine antioxidants, p-
Examples include antioxidants such as phenylenediamine antioxidants and thiobisphenol antioxidants.

As the pulp, straw pulp, bamboo pulp, wood pulp (conifer pulp, hardwood pulp) and the like may be used, and any of chemical pulp and mechanical pulp may be used. The size of the cellulose filler such as pulp and wood flour is not particularly limited, but is generally 5 μm to 100 μm.
0μ, preferably about 10μ to 200μ. The amount of cellulose is generally 15 to 70 parts by weight, preferably 20 to 60 parts by weight, based on 100 parts by weight of the amino resin.

In preparing the composition of the present invention, any means capable of uniformly mixing the amino resin, mineral powder, and, if desired, other secondary amounts of resin and additives can be employed. For example, kneaders, ribbon blenders, Henschel mixers,
Examples thereof include a ball mill, roll kneading, a grinder, a tumbler and the like.

By blending the above-mentioned raw materials and producing by the above-mentioned method, the T90 value by a curast meter is 280 to 420 seconds at a mold surface temperature of 145 ° C., preferably 300 to 400 seconds. A resin composition for cleaning a mold is produced. In a composition having a T90 value that is too large, if automatic molding is performed at a low temperature, blisters will occur during molding, depending on the molding time, and the cleaning material itself will remain in the mold, resulting in a poor cleaning effect. On the other hand, for a material having a T90 value that is too small, the cleaning effect is reduced when automatic molding is performed under high temperature conditions. Therefore, the number of shots must be increased in order to properly clean the material.

The curable resin molding material which can clean the mold using the composition of the present invention is, for example, an epoxy resin molding material, a phenol resin molding material or the like, preferably an epoxy resin molding material, and especially a semiconductor sealing material. It is an epoxy resin molding material for stopping. Further, as the mold to which the resin composition for mold cleaning of the present invention is applied, any mold can be used as long as it is a mold used for automatically molding the cured resin molding material. A mold made of chrome or the like can be applied.

When the resin composition for cleaning a mold having the composition of the present invention is used for cleaning an automatic molding die for a curable resin molding material, it can be used in a wide range of temperature conditions as compared with a conventional cleaning material. And shows a good cleaning effect in the curing time range.

[0029]

The present invention will be specifically described below with reference to examples. The measurement of the curing speed was performed by the following method.

(1) Measurement of curing speed (T90 value) using a curast meter A commercially available JSR type curast meter is used to set the mold surface temperature to 145 ° C, apply vibration deformation with a constant amplitude, and clean the mold with respect to the curing time. The change in stress generated in the resin composition for use is detected. The maximum value at which the stress change becomes substantially constant is defined as 100%, and the time from the start of hardening to the generated stress corresponding to 90% of the maximum stress is defined as T90 value (second).

Example 1 346 parts by weight of melamine, 131 parts by weight of phenol, 522 parts by weight of formalin (37% aqueous solution), and 4 parts by weight of potassium hydroxide were heated and reacted in a reaction vessel equipped with a stirrer, and melamine was produced by a known method. Make a phenol co-condensation resin solution. The resin solution was dried under reduced pressure to obtain 70 parts by weight of a powder, 20 parts by weight of silica powder having a particle size of # 200, 9.5 parts by weight of pulp, 0.05 parts by weight of benzoic acid and 0 parts by weight of zinc stearate. The mixture was pulverized with a ball mill to obtain a resin composition A for cleaning a mold. The T90 value of the obtained resin composition for cleaning a mold was 355 seconds at a mold surface temperature of 145 ° C. Table 1 shows the test results of the cleaning effect. As can be seen from the test results, a good cleaning effect was obtained under a wide range of cleaning molding conditions.

Example 2 A resin powder was produced in the same manner as in Example 1 except that formalin was added in an amount of 730 parts by weight, and 70 parts by weight of the resin powder, 20 parts by weight of silica powder having a particle size of # 200, and further powder pulp 9.5 parts by weight and 0.5 part by weight of zinc stearate were added, and the mixture was pulverized by a ball mill to obtain a resin composition B for mold cleaning.
The T90 value of the obtained resin composition for cleaning a mold was 362 seconds at a mold surface temperature of 145 ° C. Table 1 shows the cleaning effect test results. As can be seen from the test results, a good cleaning effect was obtained under a wide range of cleaning molding conditions.

Example 3 A melamine-urea cocondensation resin solution was prepared by a known method using 360 parts by weight of melamine, 90 parts by weight of urea, and 550 parts by weight of formalin (37% aqueous solution), and dried under reduced pressure to obtain a powder. 60 parts by weight, quartz powder 2 of particle size # 1000
0 parts by weight, further 20 parts by weight of powdered pulp, 0.04 parts by weight of phthalic anhydride and 0.5 parts by weight of zinc stearate,
The mixture was pulverized with a ball mill to obtain a resin composition C for cleaning a mold.
The T90 value of the obtained resin composition for cleaning a mold was 318 seconds at a mold surface temperature of 145 ° C. Table 1 shows the test results of the cleaning effect. As can be seen from the test results, a good cleaning effect was obtained under a wide range of cleaning molding conditions.

Example 4 A melamine phenol co-condensation resin powder was prepared in the same manner as in Example 1, and 70 parts by weight of the powder, 20 parts of silica powder having a particle size of # 600, 0.015 parts by weight of benzoic acid, and wood Powder 12
By weight, 0.5 part by weight of zinc stearate was added, and the mixture was pulverized with a ball mill to obtain a resin composition D for cleaning a mold. The T90 value of the obtained resin composition for cleaning a mold is a mold surface temperature of 1
It was 402 seconds at 45 ° C. Table-Test result of cleaning effect
Write it in 1. As can be seen from the test results, a good cleaning effect was obtained under a wide range of cleaning molding conditions.

Comparative Example 1 In the same manner as in Example 1, the amount of benzoic acid added was 0.15.
Parts by weight and a T90 value of 210 at a mold surface temperature of 145 ° C.
A second mold cleaning resin composition E was prepared.

Comparative Example 2 In the same manner as in Example 1, the amount of benzoic acid was
A mold cleaning resin composition F having a T90 value of 460 seconds at a mold surface temperature of 145 ° C. was produced.

The results of a mold cleaning test performed using the mold cleaning resin compositions A to F according to the following test methods are shown in the following Table.
It is shown in FIG.

Test Method Using a commercially available epoxy resin molding material (Nitron MP manufactured by Nitto Denko Corporation) mini-tablet, a sealed molded product was subjected to 400 shot transfer molding with a mold for an automatic molding machine.
The mold was contaminated. Next, the mold was used as a test temperature, the curing time was changed, and after performing five-shot molding using the mold cleaning resin composition, the mold surface was observed and the cleaning effect was evaluated as follows. 5: There is no fogging etc. 4: There is almost no fogging 3: There is some fogging 2: There is fogging 1: There is much dirt

[0039]

[Table 1]

[0040]

As described above, during the automatic molding of the curable resin molding material, the curing speed of the resin composition for cleaning the mold to remove stains on the surface of the mold with a curast meter at a mold surface temperature of 145 ° C. By setting the T90 value to 280 seconds to 420 seconds, a wide range of suitable cleaning effects can be exhibited under various automatic molding conditions for epoxy resin molded products.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-175210 (JP, A) JP-A-3-140214 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 33/72 C08L 1/00-101/16 C08K 3/00-13/08

Claims (1)

(57) [Claims] 1. A resin composition for cleaning a mold, which removes stains on the surface of the mold during automatic molding of the curable resin molding material.
The resin composition for cleaning a mold is a melamine resin or a mineral powder.
Body, a cellulose filler, a curing catalyst, and a lubricant.
A resin composition for cleaning a mold, wherein the T90 value at 45 ° C. is 280 to 420 seconds.