TWI849275B - Resin composition for mold cleaning - Google Patents

Abstract

A resin composition for mold cleaning includes: a melamine resin; a filler; an acidic compound; and at least one compound selected from the group consisting of imide compounds having a molecular weight of 500 or lower and urea compounds having a molecular weight of 500 or lower, in which the acidic compound is a different compound from the imide compounds, and the ratio of the total content by mass of the imide compounds and the urea compounds relative to the content by mass of the acidic compound is in the range of from 0.01 to 100.0.

Description

Resin composition for mold cleaning

The present disclosure relates to a resin composition for mold cleaning.

In recent years, with the high functionality of mobile devices represented by smartphones, the miniaturization of semiconductors has also progressed. In addition, due to the rapid development of the popularization of industrial robots and the electrification of automobiles due to the shortage of manpower and cost reduction, the types and quantities of semiconductors used have increased sharply, and the frequency of semiconductor updates has also increased. In line with this situation, molds that can cope with the multi-cavity design of the package body and the complexity of the semiconductor pattern are becoming popular.

With the recent demand for more efficient molding of semiconductor encapsulating resins, there is also a demand for more efficient cleaning of resin compositions used for cleaning molding dies (so-called mold cleaning resin compositions). In order to efficiently clean molding dies, it is expected that the mold cleaning resin composition exhibits high fluidity such as being able to quickly spread to every corner inside the molding dies. Several reports have been made on methods for controlling the fluidity of mold cleaning resin compositions.

For example, in Japanese Patent Publication No. 2019-126966, by using a blocked carboxylic acid as a hardener for a melamine-based resin, a mold cleaning resin composition is achieved that exhibits the fluidity (so-called appropriate fluidity) necessary to reach every corner inside a molding mold even at low temperatures. In addition, in Japanese Patent Publication No. 2017-177623, by using a variety of hardening catalysts, a mold cleaning resin composition that achieves a balance between hardening and fluidity is achieved. Furthermore, in International Publication No. 2013/011876, by using an inorganic filler whose average particle size, standard deviation of the particle size, average aspect ratio of the particle size, and standard deviation of the aspect ratio of the particle size fall within specific ranges, a mold cleaning resin composition that exhibits good fluidity that can reach every corner of the internal space of the mold is achieved.

[The problem that the invention wants to solve]

In the molding mold, with the progress of multi-cavity design, miniaturization, and complexity of patterns, it is difficult to make the mold cleaning resin composition spread to every corner inside the molding mold by simply controlling the fluidity of the mold cleaning resin composition. Therefore, a response is made to increase the speed and pressure of the plunger that injects the mold cleaning resin composition into the mold. However, due to this response, when cleaning the molding mold, the mold cleaning resin composition will easily invade the gap between the mold surface and friction surface of the molding mold and produce burrs. If burrs are produced, when the semiconductor sealing resin is molded, poor conditions such as reduced workability, contamination of the molded product, and uneven quality of the molded product will occur. Therefore, in addition to excellent cleaning performance, the resin composition for mold cleaning is also required to be resistant to burrs.

Regarding the above aspects, Japanese Patent Publication No. 2019-126966, Japanese Patent Publication No. 2017-177623, and International Publication No. 2013/011876 do not focus on any problem related to the generation of burrs in the resin composition for mold cleaning.

The problem to be solved by one embodiment of the present disclosure is to provide a mold cleaning resin composition that is not prone to burrs and has excellent cleaning performance. [Means for solving the problem]

Specific means for solving the problem include the following aspects. <1> A resin composition for mold cleaning, comprising: A melamine resin, A filler, An acidic compound, and At least one compound selected from the group consisting of an imide compound with a molecular weight of 500 or less and a urea compound with a molecular weight of 500 or less; The acidic compound is a compound different from the imide compound; The ratio of the total content of the imide compound and the urea compound to the content of the acidic compound is within the range of 0.01 or more and 100.0 or less. <2> The mold cleaning resin composition as described in <1>, wherein the total content of the acidic compound, the imide compound, and the urea compound is within the range of 0.1 parts by mass or more and 12.0 parts by mass or less relative to 100 parts by mass of the total of the melamine resin and the filler. <3> The mold cleaning resin composition as described in <1> or <2>, wherein the imide compound is at least one selected from the group consisting of o-xylylenediamine, succinimide, pyromelite, 1,2,3,6-tetrahydroxylylenediamine, and 1,2-cyclohexanedicarboxylic acid imide, and the urea compound is at least one selected from the group consisting of urea, 1-methylurea, 1-ethylurea, 1,1-dimethylurea, and 1,3-dimethylurea. <4> The mold cleaning resin composition as described in any one of <1> to <3>, wherein the acidic compound is a compound having a carboxyl group. <5> A mold cleaning resin composition as described in any one of <1> to <3>, wherein the acidic compound is at least one selected from the group consisting of benzoic acid, tartaric acid, hydrochloric acid, sulfamic acid, and trimellitic acid. <6> A mold cleaning resin composition as described in any one of <1> to <5>, wherein the content of the acidic compound is within the range of 0.01 parts by mass or more and 5.0 parts by mass or less relative to 100 parts by mass of the total of the melamine resin and the filler. <7> A mold cleaning resin composition as described in any one of <1> to <6>, comprising a metal soap. <8> A mold cleaning resin composition as described in any one of <1> to <7>, comprising a lubricant. [Effect of the invention]

According to one embodiment of the present disclosure, a resin composition for cleaning a mold is provided which is not prone to burrs and has excellent cleaning performance.

The following is a detailed description of the specific implementation of the present disclosure. However, the present disclosure is not limited to the following implementation and can be implemented with appropriate modifications within the scope of the purpose of the present disclosure.

The numerical range indicated by "~" in this disclosure refers to a range that includes the numerical values recorded before and after "~" as the minimum and maximum values, respectively. In the numerical range recorded in the present disclosure, the upper limit or lower limit recorded in a numerical range can also be replaced by the upper limit or lower limit of another numerical range recorded in another stage. In addition, in the numerical range recorded in the present disclosure, the upper limit or lower limit recorded in a numerical range can also be replaced by the numerical value shown in the embodiment. In this disclosure, a combination of more than 2 more ideal aspects is a more ideal aspect. In this disclosure, the amount of each component, when there are multiple substances that should be each component, refers to the total amount of multiple substances unless otherwise specified.

In this disclosure, the so-called "inner surface of the forming mold" refers to the area that contacts the object formed by the forming mold.

[Resin composition for mold cleaning] The resin composition for mold cleaning disclosed herein (hereinafter, also simply referred to as "resin composition") contains a melamine resin, a filler, an acidic compound, and at least one compound selected from the group consisting of an imide compound having a molecular weight of 500 or less (hereinafter, also referred to as "specific imide compound") and a urea compound having a molecular weight of 500 or less (hereinafter, also referred to as "specific urea compound"), wherein the acidic compound is a compound different from the specific imide compound, and the ratio of the total content of the specific imide compound and the specific urea compound to the content of the acidic compound is within the range of 0.01 or more and 100.0 or less. In the following, the specific imide compound and the specific urea compound are sometimes collectively referred to as "specific compound" in the present disclosure.

The curing reaction in the mold cleaning resin composition containing a melamine resin and a curing catalyst is carried out in the following manner. First, the melamine resin contained in the mold cleaning resin composition is melted by heating. Then, the curing catalyst acts on the molten melamine resin to harden the mold cleaning resin composition. Generally, the curing speed of the mold cleaning resin composition is greatly affected by the content of the curing catalyst. If the amount of the curing catalyst contained in the mold cleaning resin composition is large, the curing speed of the mold cleaning resin composition will become faster and the fluidity will decrease. In the molding mold, with the development of multi-cavity design, miniaturization, and the complexity of patterns, it is difficult to control the fluidity of the mold cleaning resin composition by simply adjusting the content of the hardening catalyst. In addition, it is difficult to make the mold cleaning resin composition spread to every corner inside the molding mold by simply controlling the fluidity of the mold cleaning resin composition. Therefore, in recent years, measures have been taken to increase the speed and pressure of the plunger that injects the mold cleaning resin composition into the mold. However, due to this measure, when cleaning the molding mold, the mold cleaning resin composition will easily invade the gap between the mold surface, friction surface, etc. of the molding mold and produce burrs. If burrs are generated, poor workability, contamination of the molded product, and uneven quality of the molded product may occur when the semiconductor sealing resin is molded.

In contrast, the mold cleaning resin composition disclosed herein contains an acidic compound as a curing catalyst and at least one of a specific imide compound and a specific urea compound in a specific range of mass ratios, so it is not easy to produce burrs when cleaning the forming mold, and has excellent cleaning performance. The reason why the mold cleaning resin composition disclosed herein can exert such an effect is still unclear, but the inventors of this case speculate as follows. However, the following speculation does not provide a restrictive interpretation of the mold cleaning resin composition disclosed herein, but is used as an example for explanation.

It is believed that in the mold cleaning resin composition disclosed herein, the acidic compound plays a role in accelerating the curing rate, while the specific imide compound and the specific urea compound play a role in delaying the curing rate. Therefore, it is believed that if the mold cleaning resin composition disclosed herein is heated, a cured product with a larger molecular weight (in other words, a longer molecular chain) and a cured product with a smaller molecular weight (in other words, a shorter molecular chain) will coexist in the curing stage. It is speculated that these cured products with different molecular weights will be intertwined with each other appropriately, suppressing excessive viscosity reduction, thereby making the fluidity of the mold cleaning resin composition appropriate, and as a result, the mold cleaning resin composition will be suppressed from invading the gap of the molding mold and suppressing the generation of burrs. In addition, it is believed that since the mold cleaning resin composition has an appropriate fluidity, the mold cleaning resin composition spreads to every corner inside the molding mold, and thus the excellent cleaning performance of the melamine resin can be effectively exerted. Also, although the detailed mechanism is not clear, the mold cleaning resin composition disclosed in the present invention can exert the effect of reducing the amount of formaldehyde generated during molding.

<Melamine resin> The resin composition disclosed herein contains a melamine resin. In the resin composition disclosed herein, the melamine resin contributes to cleaning performance. Melamine resin has a highly polar hydroxyl group. It is believed that in the resin composition containing the melamine resin, the highly polar hydroxyl group of the melamine resin acts on dirt (hereinafter also referred to as "contaminant") from a sealing molding material containing a thermosetting resin represented by an epoxy resin, thereby exerting a cleaning performance effect.

The "melamine-based resin" referred to in the present disclosure refers to at least one selected from the group consisting of melamine resin, melamine-phenol co-condensate, and melamine-urea co-condensate.

Melamine resin is a condensation product of a trioxane compound and an aldehyde compound. As for trioxane compounds, melamine, benzoguanamine, acetylguanamine, etc. can be listed. As for aldehyde compounds, formaldehyde, paraformaldehyde, acetaldehyde, etc. can be listed. For melamine resin, the molar ratio of repeating units from trioxane compounds to repeating units from aldehyde compounds (repeating units from trioxane compounds/repeating units from aldehyde compounds) is 1/1.2~1/4, which is more ideal.

Melamine-phenol co-condensation products are co-condensation products of trioxane compounds, phenol compounds, and aldehyde compounds. As for phenol compounds, phenol, cresol, xylenol, ethylphenol, and butylphenol can be listed. For melamine-phenol co-condensation products, the molar ratio of repeating units from trioxane compounds to repeating units from phenol compounds (repeating units from trioxane compounds/repeating units from phenol compounds) is 1/0.3~1/1, which is more ideal. In addition, in the case of melamine-phenol co-condensate, the molar ratio of the repeating units derived from the trioxane compound to the repeating units derived from the aldehyde compound (repeating units derived from the trioxane compound/repeating units derived from the aldehyde compound) is preferably 1/1 to 1/3.

Melamine-urea co-condensation products are co-condensation products of tricyanamide compounds, urea compounds, and aldehyde compounds. Urea compounds include urea, thiourea, ethylene urea, etc.

Melamine resins can be produced by known methods. For example, in the case of melamine resin, melamine crystals and formaldehyde are stirred at a molar ratio (melamine crystals/formaldehyde) of 1/1.2 to 1/4, a heating temperature of 70°C to 100°C, and a pH of 7 to 7.5, and then cooled and reacted at 60°C until a 3% by mass aqueous solution of the reaction product becomes cloudy (for example, 1 hour). Then, sodium hydroxide is added to the obtained reaction product until the pH becomes 8.0 to 9.0, and then cooled to produce melamine resin.

As for the melamine resin, a commercial product can be used. Examples of commercial products of melamine resin include Nikaresin (registered trademark) S-166, Nikaresin (registered trademark) S-176, Nikaresin (registered trademark) S-260, Nikaresin (registered trademark) S-305, etc., manufactured by NIPPON CARBIDE INDUSTRIES (Co., Ltd.).

The resin composition disclosed herein may contain only one melamine-based resin or may contain two or more melamine-based resins.

The content of melamine-based resin in the resin composition disclosed herein is not particularly limited. For example, relative to 100 parts by mass of the total solid content of the resin composition, the range of 10 parts by mass or more and 90 parts by mass or less is more ideal, 15 parts by mass or more and 85 parts by mass or less is more ideal, 20 parts by mass or more and 80 parts by mass or less is more ideal, and 25 parts by mass or more and 75 parts by mass or less is particularly ideal. In the present disclosure, the so-called "total solid content of the resin composition" refers to the total mass of the resin composition when the resin composition does not contain a solvent (e.g., water; the same applies hereinafter); and refers to the mass of the residue after the solvent is removed from the resin composition when the resin composition contains a solvent.

<Filler> The resin composition disclosed herein contains a filler. If the resin composition disclosed herein contains a filler, the strength of the molded product of the resin composition can be appropriately maintained, so that the workability when removing the molded product of the resin composition from the molding mold after cleaning can be improved. The filler can be any of an organic filler and an inorganic filler.

(Organic fillers) As for organic fillers, paper pulp, wood powder, and synthetic fibers can be listed. Among these, paper pulp is particularly ideal as an organic filler. As for paper pulp, wood pulp (coniferous tree pulp, broad-leaved tree pulp, etc.), non-wood pulp (straw, bamboo, bagasse, cotton, etc.) can be listed. These pulps can be any of chemical pulp and mechanical pulp.

When the resin composition disclosed herein contains pulp as an organic filler, the pulp is preferably used in the form of pulp impregnated with a melamine resin. The pulp impregnated with a melamine resin is in a state where at least a portion of the melamine resin penetrates into the gaps between pulp fibers, or at least a portion of the melamine resin covers a portion or all of the surface of the pulp fibers. The pulp impregnated with a melamine resin can be obtained by impregnating the pulp with an aqueous solution containing a melamine resin and then drying it.

There is no particular restriction on the size of the pulp. For example, the size of the pulp is preferably within the range of 5 μm or more and 1000 μm or less, and more preferably within the range of 10 μm or more and 200 μm or less. If the size of the pulp is within the above range, the strength of the resin composition molded product can be more appropriately maintained, so that the workability when removing the resin composition molded product from the molding mold after cleaning can be improved. In addition, if the size of the pulp is within the above range, the fluidity of the resin composition tends to be more appropriate. The fiber length of the pulp is a value measured in accordance with the method specified in JIS P8226-2:2011 corresponding to ISO16065-2:2007.

As for the pulp, commercially available products can be used. Examples of commercially available pulp include "NSPP1" (trade name, coniferous tree pulp) and "LDPT" (trade name, broad-leaved tree pulp) of Nippon Paper Industries, Ltd.

When the resin composition of the present disclosure contains an organic filler as a filler, it may contain only one kind of organic filler or may contain two or more kinds of organic fillers.

When the resin composition disclosed herein contains an organic filler as a filler, the content of the organic filler is not particularly limited. For example, it is more ideal to have a range of 2 mass parts or more and 50 mass parts or less relative to 100 mass parts of the total solid components of the resin composition, more ideal to have a range of 2 mass parts or more and 30 mass parts or less, and even more ideal to have a range of 2 mass parts or more and 15 mass parts or less. If the content of the organic filler in the resin composition disclosed herein falls within the above range relative to 100 mass parts of the total solid components of the resin composition, the strength of the molded product of the resin composition can be more appropriately maintained, so that the workability when removing the molded product of the resin composition from the molding mold after cleaning can be further improved. Furthermore, if the content of the organic filler in the resin composition of the present disclosure is within the above range relative to 100 parts by mass of the total solid content of the resin composition, the fluidity of the resin composition tends to be more appropriate.

(Inorganic fillers) Inorganic fillers not only help improve workability by maintaining the appropriate strength of the molded product of the resin composition, but also help improve cleaning performance by physically polishing the inner surface of the mold. As for inorganic fillers, they can be listed as silicon carbide, silicon oxide (so-called silicon dioxide; the same applies hereinafter), titanium carbide, titanium oxide, boron carbide, boron oxide, aluminum oxide, magnesium oxide, calcium oxide, calcium carbonate, etc. Among these, in terms of inorganic fillers, from the perspective of being able to mix well with melamine-based resins when preparing resin compositions, at least one selected from the group consisting of silicon carbide, silicon oxide, titanium carbide, titanium oxide, boron carbide, boron oxide, aluminum oxide, magnesium oxide, and calcium oxide is more preferred, and at least one selected from the group consisting of silicon oxide and titanium oxide is more preferred. Although it is also related to the material and state of the molding die, it cannot be generalized, but silicon oxide and titanium oxide are more preferred from the perspective of having appropriate hardness and being able to suppress wear of the inner surface of the molding die and the gate portion, and suppressing damage.

The hardness of the inorganic fillers listed above (so-called new Mohs hardness) is 13 for silicon carbide, 8 for silicon oxide, 9 for titanium carbide, 8 for titanium oxide, 14 for boron carbide, 3 for boron oxide, 12 for aluminum oxide, 4 for magnesium oxide, and 3 for calcium oxide.

As for the inorganic filler, commercially available products can be used. Examples of commercially available inorganic fillers include "S440-4", "HS-202", "HS-204", and "UF-320" (all trade names, and all amorphous silicon dioxide) from Nippon Steel & Sumikin Materials Co., Ltd. Micron Co., and pure silica powder (trade name, crystalline silicon dioxide) from Seto Kiln Materials Co., Ltd.

When the resin composition of the present disclosure contains an inorganic filler as a filler, it may contain only one kind of inorganic filler or may contain two or more kinds of inorganic fillers.

When the resin composition disclosed herein contains an inorganic filler as a filler, the content of the inorganic filler is not particularly limited. For example, it is more ideal to have a range of 5 mass parts or more and 30 mass parts or less relative to 100 mass parts of the total solid components of the resin composition, and it is more ideal to have a range of 10 mass parts or more and 25 mass parts or less. If the content of the inorganic filler in the resin composition disclosed herein falls within the above range relative to 100 mass parts of the total solid components of the resin composition, the strength of the molded product of the resin composition can be more appropriately maintained, so that the workability when removing the molded product of the resin composition from the molding mold after cleaning can be further improved. Furthermore, if the content of the inorganic filler in the resin composition of the present disclosure is within the above range relative to 100 parts by mass of the total solid content of the resin composition, the fluidity of the resin composition tends to be more appropriate.

<Acidic compound> The resin composition disclosed herein contains an acidic compound. In the resin composition disclosed herein, the acidic compound can function as a hardening catalyst for melamine resin. The acidic compound can be any substance that can harden melamine resin, and a typical example is Brunstrian acid. In addition, the acidic compound is a compound different from the specific imide compound. In other words, the compound corresponding to the specific imide compound is not included in this acidic compound.

The acidic compound can be an organic acid or an inorganic acid. Examples of acidic compounds that are organic acids include benzoic acid, tartaric acid, sulfamic acid, trimellitic acid, trimesic acid, acetic acid, behenic acid, palmitic acid, salicylic acid, and o-toluene. Formic acid, phthalic acid, isophthalic acid, terephthalic acid, adipic acid, oxalic acid, 2-phenylsuccinic acid, 1,2-cyclohexanedicarboxylic acid, sebacic acid, etc. Examples of acidic compounds that are inorganic acids include hydrochloric acid, sulfuric acid, and phosphoric acid.

As for the acidic compound, for example, from the viewpoint of inhibiting burr generation and cleaning performance, at least one selected from the group consisting of benzoic acid, tartaric acid, hydrochloric acid, sulfamic acid, and trimellitic acid is more desirable, and at least one selected from the group consisting of benzoic acid, tartaric acid, sulfamic acid, and trimellitic acid is more desirable.

Furthermore, the acidic compound is preferably a compound having a carboxyl group. If the acidic compound is a compound having a carboxyl group, burrs tend to be less likely to occur than when the acidic compound is a compound not having a carboxyl group. Also, although the detailed mechanism is not clear, the amount of formaldehyde generated during the molding of the resin composition tends to be further reduced.

As for the compounds having a carboxyl group, benzoic acid, tartaric acid, trimellitic acid, trimesic acid, acetic acid, behenic acid, palmitic acid, salicylic acid, o-methylbenzoic acid, phthalic acid, isophthalic acid, terephthalic acid, adipic acid, oxalic acid, 2-phenylsuccinic acid, 1,2-cyclohexanedicarboxylic acid, sebacic acid, etc. among the above-mentioned acidic compounds are suitable.

The resin composition disclosed herein may contain only one acidic compound or may contain two or more acidic compounds.

The content of the acidic compound in the resin composition disclosed herein is not particularly limited. For example, relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), the range of 0.01 parts by mass or more and 5.0 parts by mass or less is more ideal, the range of 0.02 parts by mass or more and 3.0 parts by mass or less is more ideal, the range of 0.03 parts by mass or more and 2.0 parts by mass or less is more ideal, and the range of 0.03 parts by mass or more and 1.0 parts by mass or less is particularly ideal. If the content of the acidic compound in the resin composition disclosed herein falls within the above range relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), burrs tend to be less likely to occur. Furthermore, if the content of the acidic compound in the resin composition of the present disclosure is within the above range relative to 100 parts by weight of the total of the melamine-based resin and the filler (i.e., the organic filler and the inorganic filler), the resin composition tends to exhibit better cleaning performance.

<Specific compound> The resin composition disclosed herein contains at least one compound (i.e., specific compound) selected from the group consisting of an imide compound having a molecular weight of 500 or less (i.e., specific imide compound) and a urea compound having a molecular weight of 500 or less (i.e., specific urea compound). In the resin composition disclosed herein, the specific compound contributes to the adjustment of the curing speed.

The resin composition disclosed herein may contain only a specific imide compound, only a specific urea compound, or both a specific imide compound and a specific urea compound as the specific compound.

The molecular weight of the specific imide compound is 500 or less, preferably 50 or more and 500 or less, more preferably 50 or more and 400 or less, and even more preferably 50 or more and 300 or less. The molecular weight of the specific imide compound is 500 or less, which means that so-called high molecular weight compounds are excluded. For example, the specific imide compound does not include an imide resin.

As for the specific imide compounds, there are no particular limitations, and examples thereof include o-xylylenediamine (molecular weight: 147), succinimide (molecular weight: 99), pyrohexylite (molecular weight: 216), 1,2,3,6-tetrahydroxylenediamine (molecular weight: 151), 1,2-cyclohexanedicarboxylic acid imide (molecular weight: 153), maleimide (molecular weight: 97), 4-aminoxylenediamine (molecular weight: 162), 3,3-dimethylpentanediamine (molecular weight: 141), and N-(cyclohexylthio)xylenediamine (molecular weight: 261). In addition, 1,2,3,6-tetrahydrophthalimide has cis-isomers and trans-isomers. However, the 1,2,3,6-tetrahydrophthalimide in the present disclosure may be any of the cis-isomers and the trans-isomers, or may be a mixture of these isomers.

As for the specific imide compound, for example, at least one selected from the group consisting of o-xylylenediamine, succinimide, pyromelite imide, 1,2,3,6-tetrahydroxylylenediamine, and 1,2-cyclohexanedicarboximide is more preferred, and at least one selected from the group consisting of o-xylylenediamine, succinimide, 1,2,3,6-tetrahydroxylylenediamine, and 1,2-cyclohexanedicarboximide is more preferred. At least one selected from the group consisting of 3,6-tetrahydroxylenedicarboxylic acid imide and 1,2-cyclohexanedicarboxylic acid imide is more preferred, at least one selected from the group consisting of succinimide and 1,2,3,6-tetrahydroxylenedicarboxylic acid imide is even more preferred, and 1,2,3,6-tetrahydroxylenedicarboxylic acid imide is particularly preferred. In addition, as for the specific imide compound, for example, from the viewpoint of further improving the inhibition of burrs, at least one selected from the group consisting of xylenedicarboxylic acid imide and succinimide is more preferred. In addition, the specific imide compound is preferably at least one selected from the group consisting of succinimide, 1,2,3,6-tetrahydroxylylenediamine, and 1,2-cyclohexanedicarboximide, for example, from the viewpoint of further improving the cleaning performance.

When the resin composition of the present disclosure contains a specific imide compound as the specific compound, it may contain only one specific imide compound or may contain two or more specific imide compounds.

The molecular weight of the specific urea compound is 500 or less, preferably 50 or more and 500 or less, and more preferably 50 or more and 200 or less. The molecular weight of the specific urea compound is 500 or less, which means that so-called high molecular weight compounds are excluded. For example, the specific urea compound does not include urea resin.

The specific urea compound is not particularly limited, and examples thereof include urea (molecular weight: 60), 1-methylurea (molecular weight: 74), 1-ethylurea (molecular weight: 88), 1,1-dimethylurea (molecular weight: 88), 1,3-dimethylurea (molecular weight: 88), butyl urea (molecular weight: 116), 2,5-dithiobisurea (molecular weight: 150), (4-ethoxyphenyl)urea (molecular weight: 180), etc.

As for the specific urea compound, for example, at least one selected from the group consisting of urea, 1-methylurea, 1-ethylurea, 1,1-dimethylurea, and 1,3-dimethylurea is more preferred, at least one selected from the group consisting of urea, 1,1-dimethylurea, and 1,3-dimethylurea is more preferred, at least one selected from the group consisting of urea and 1,3-dimethylurea is even more preferred, and urea is particularly preferred. In addition, as for the specific urea compound, for example, from the viewpoint of further improving the cleaning performance, at least one selected from the group consisting of 1,1-dimethylurea and 1,3-dimethylurea is more preferred, and from the viewpoint of further improving the suppression of burrs, 1,3-dimethylurea is more preferred.

When the resin composition of the present disclosure contains a specific urea compound as the specific compound, it may contain only one specific urea compound or may contain two or more specific urea compounds.

The content of the specific compound in the resin composition disclosed herein (i.e., the total content of the specific imide compound and the specific urea compound) is not particularly limited. For example, relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), the range of 0.01 parts by mass or more and 7.0 parts by mass or less is more ideal, the range of 0.1 parts by mass or more and 5.0 parts by mass or less is more ideal, the range of 0.1 parts by mass or more and 4.0 parts by mass or less is even more ideal, and the range of 0.1 parts by mass or more and 3.0 parts by mass or less is particularly ideal. If the content of the specific compound in the resin composition of the present disclosure (i.e., the total content of the specific imide compound and the specific urea compound) is within the above range relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), burrs tend to be less likely to be generated. Furthermore, if the content of the specific compound in the resin composition of the present disclosure (i.e., the total content of the specific imide compound and the specific urea compound) is within the above range relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), the resin composition tends to exhibit better cleaning performance.

In the resin composition disclosed herein, the ratio of the mass content of the specific compound (i.e., the total mass content of the specific imide compound and the specific urea compound) to the mass content of the acidic compound (mass content of the specific compound/mass content of the acidic compound) is in the range of 0.01 or more and 100.0 or less, preferably in the range of 0.02 or more and 90.0 or less, more preferably in the range of 0.5 or more and 80.0 or less, more preferably in the range of 1.5 or more and 70.0 or less, and particularly preferably in the range of 3.0 or more and 60.0 or less. The resin composition disclosed herein, if the mass content of the specific compound/mass content of the acidic compound falls within the above range, tends to be less likely to produce burrs. Furthermore, the resin composition disclosed herein tends to exhibit excellent cleaning performance if the content mass of the specific compound/the content mass of the acidic compound falls within the above range.

In the resin composition disclosed herein, the total content of the acidic compound, the specific imide compound, and the specific urea compound is preferably in the range of 0.1 mass part or more and 12.0 mass parts or less, more preferably in the range of 0.2 mass part or more and 7.0 mass parts or less, more preferably in the range of 0.3 mass part or more and 6.0 mass parts or less, and particularly preferably in the range of 0.4 mass part or more and 5.0 mass parts or less, relative to 100 mass parts of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler). The resin composition disclosed herein, if the total content of the acidic compound, the specific imide compound, and the specific urea compound falls within the above range relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), tends to be less likely to produce burrs. Furthermore, the resin composition disclosed herein, if the total content of the acidic compound, the specific imide compound, and the specific urea compound falls within the above range relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), tends to exhibit excellent cleaning performance.

<Metal Soap> The resin composition disclosed herein preferably contains a metal soap. If the resin composition disclosed herein contains a metal soap, the resin composition can exhibit a better cleaning performance because the fluidity of the resin composition is improved when cleaning the molding die, and the melamine resin can easily act on the dirt on the inner surface of the molding die. In addition, if the resin composition disclosed herein contains a metal soap, the resin composition can exhibit a better cleaning performance because the affinity between the resin composition and the dirt on the inner surface of the molding die is improved.

There is no particular limitation on metal soaps, and examples thereof include fatty acid metal salts composed of fatty acids and metals. The fatty acid constituting the fatty acid metal salt may be any of saturated fatty acids and unsaturated fatty acids, and saturated fatty acids are more preferred. The carbon number of the fatty acid constituting the fatty acid metal salt is not particularly limited, and for example, 12 to 20 is more preferred, and 14 to 18 is more preferred. As for fatty acids with 12 to 20 carbon atoms, specific examples include lauric acid with 12 carbon atoms (IUPAC name: dodecanoic acid), myristic acid with 14 carbon atoms (IUPAC name: tetradecanoic acid), palmitic acid with 16 carbon atoms (IUPAC name: hexadecanoic acid), stearic acid with 18 carbon atoms (IUPAC name: octadecanoic acid), oleic acid with 18 carbon atoms (IUPAC name: cis-9-octadecanoic acid), and arachidic acid with 20 carbon atoms (IUPAC name: eicosanoic acid). The metal constituting the fatty acid metal salt is not particularly limited, and it is preferably at least one selected from the group consisting of zinc, aluminum, magnesium, and calcium, and zinc is more preferably.

Specific examples of fatty acid metal salts include zinc stearate, zinc myristic acid, zinc laurate, zinc palmitate, aluminum stearate, magnesium oleate, magnesium stearate, calcium stearate, sodium 12-hydroxystearate, potassium octadecanoate, lithium laurate, and the like.

When the resin composition of the present disclosure contains a metal soap, it may contain only one kind of metal soap or may contain two or more kinds of metal soap.

When the resin composition disclosed herein contains metal soap, the content of the metal soap is not particularly limited. For example, relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), the range of 0.1 parts by mass or more and 5.0 parts by mass or less is more ideal, the range of 0.1 parts by mass or more and 4.0 parts by mass or less is more ideal, and the range of 0.1 parts by mass or more and 3.0 parts by mass or less is even more ideal. If the content of the metal soap in the resin composition disclosed herein is 0.1 parts by mass or more relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), the resin composition can exhibit better cleaning performance because the fluidity of the resin composition is improved when cleaning the molding die, and the melamine resin can more easily act on the dirt on the inner surface of the molding die. Furthermore, if the content of the metal soap in the resin composition of the present invention is 0.1 parts by mass or more relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), the resin composition can exhibit a better cleaning performance because the affinity between the resin composition and the dirt existing on the inner surface of the molding die is further improved.

If the resin composition containing melamine resin contains excess metal soap, the remaining metal soap may remain in the molding die and contaminate the molding die. If the content of the metal soap in the resin composition disclosed herein is 5.0 parts by mass or less relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), contamination of the molding die due to the remaining metal soap tends to be less likely to occur.

<Lubricant> The resin composition disclosed herein preferably contains a lubricant (but excluding the metal soap mentioned above). In the resin composition disclosed herein, the lubricant helps to improve the dispersibility of each component when preparing the resin composition and improve the fluidity of the resin composition when cleaning the molding mold.

As for lubricants, fatty amide lubricants can be listed. As for fatty amide lubricants, saturated or unsaturated monoamide lubricants such as lauryl amide, myristic amide, erucyl amide, oleyl amide, stearyl amide, and saturated or unsaturated diamide lubricants such as methylene distearate amide, ethyl distearate amide, ethyl disoleyl amide, etc. can be listed.

When the resin composition of the present disclosure contains a lubricant, it may contain only one lubricant or may contain two or more lubricants.

When the resin composition disclosed herein contains a lubricant, the content of the lubricant is not particularly limited. For example, the content of the lubricant is preferably in the range of 0.1 parts by mass to 0.6 parts by mass, and more preferably in the range of 0.2 parts by mass to 0.5 parts by mass, relative to 100 parts by mass of the total of the melamine resin and the filler (i.e., the organic filler and the inorganic filler).

<Other ingredients> The resin composition disclosed herein may contain ingredients other than the above ingredients (so-called other ingredients) as needed within the scope that does not impair the effects of the present disclosure. As for other ingredients, various additives such as colorants (e.g., dyes and pigments), antioxidants, etc. can be listed.

When the resin composition of the present disclosure contains other components, the content of the other components in the resin composition can be appropriately set within a range that can exert the effects of the present disclosure.

[Preparation method of resin composition] The preparation method of the resin composition disclosed herein is not particularly limited. The resin composition disclosed herein can be prepared by mixing, for example, a melamine resin, a filler, an acidic compound, a specific amount of a specific compound (i.e., at least one compound selected from the group consisting of a specific imide compound and a specific urea compound), and any components such as a metal soap and a lubricant as required. In addition, the "specific amount" referred to herein refers to an amount such that the ratio of the total blending mass of the specific imide compound and the specific urea compound to the blending mass of the acidic compound (total blending mass of the specific imide compound and the specific urea compound/blending mass of the acidic compound) falls within a range of 0.01 or more and 100.0 or less. The mixing method is not particularly limited, and examples thereof include mixing methods using a known mixer such as a kneader, a ribbon mixer, a Henschel mixer, a ball mill, a roll kneader, a pestle, or a tumbler.

[Application] The resin composition disclosed herein can be used, for example, to remove dirt from the inner surface of a mold from a sealing molding material containing a thermosetting resin represented by epoxy resin, silicone resin, melamine resin, urea resin, and phenolic resin. The resin composition disclosed herein is particularly ideal as a resin composition for so-called transfer mold cleaning by cleaning the inner surface of a mold by transfer molding.

[Mold cleaning method] The resin composition disclosed in the present invention is usually processed into a tablet shape and used for cleaning the inner surface of the forming mold. Specifically, after the lead frame is arranged on the forming mold, the tablet-shaped resin composition is inserted into the groove portion, and after the mold is closed, it is injected with a plunger. At this time, the resin composition in the groove portion is passed through the flow channel portion to the gate portion and flows into the cavity. After a predetermined forming time, the mold is opened, and the molded object that is integrated with the lead frame, that is, the molded object containing the resin composition containing dirt is removed, thereby cleaning the inner surface of the forming mold. [Implementation example]

The present disclosure is described in more detail below using examples. The present disclosure is not limited to the following examples without exceeding the scope of the present disclosure.

[Preparation of melamine resin] [Production Example A: Melamine-formaldehyde resin containing pulp] 480 parts by mass of melamine and 522 parts by mass of formaldehyde (37% by mass aqueous solution) were stirred at a heating temperature of 70°C to 100°C and a pH of 7 to 7.5, then cooled and reacted at 60°C for 1 hour. Then, an aqueous sodium hydroxide solution was added to the obtained reaction product until the pH reached 8.0 to 9.0, and then cooled to obtain an aqueous solution containing melamine-formaldehyde resin. 248 parts by weight of softwood pulp (trade name: NSPP1, Nippon Paper Industries, Ltd.) as an organic filler was added to the obtained aqueous solution containing melamine-formaldehyde resin, kneaded, dried under reduced pressure, and powdered to obtain a pulp-containing melamine-formaldehyde resin (pulp content: 28% by weight).

[Preparation of resin composition] [Example 1] 30 parts by weight of melamine-formaldehyde resin containing pulp (21.6 parts by weight of melamine-formaldehyde resin) of Production Example A of melamine-based resin and melamine-formaldehyde resin [trade name: Nikaresin (registered trademark) S-166, NIPPON CARBIDE In the present invention, 50 parts by weight of silica as an inorganic filler [trade name: pure silica powder, crystalline silica, Seto Kiln Industry Raw Materials Co., Ltd.], 20 parts by weight of benzoic acid as an acidic compound [Fuji Film Wako Pure Chemical Industries Co., Ltd.], 0.12 parts by weight of o-phthalimide as a specific imide compound [Tokyo Chemical Industry Co., Ltd.], and 1.13 parts by weight of zinc stearate as a metal soap [trade name: ZINC STEARATE GF200, NOF Corporation] were fed into a ball mill and pulverized. Then, the obtained pulverized product and 0.36 parts by weight of ethylene distearylamide [trade name: ALFLOW (registered trademark) H50T, NOF Corporation] as a lubricant were added to a Nauta mixer and stirred to obtain the resin composition of Example 1.

[Example 2 to Example 11] Except that the composition of the resin composition in Example 1 is changed to the composition shown in Table 1, the same operation as Example 1 is performed to obtain the resin compositions of Examples 2 to 11.

[Example 12 to Example 18] Example 12 to Example 18 were obtained by performing the same operation as Example 1 except that the composition of the resin composition in Example 1 was changed to the composition shown in Table 2.

[Example 19 to Example 29] Example 1 was modified to the composition shown in Table 3, and the same operation as Example 1 was performed to obtain each resin composition of Example 19 to Example 29.

[Example 30 to Example 39] Example 30 to Example 39 were obtained by performing the same operation as Example 1 except that the composition of the resin composition in Example 1 was changed to the composition shown in Table 4.

[Example 40 to Example 44] Except that the composition of the resin composition in Example 1 was changed to the composition shown in Table 5, the same operation as Example 1 was performed to obtain the resin compositions of Examples 40 to 44.

[Example 45 to Example 53] Example 45 to Example 53 were obtained by performing the same operation as Example 1 except that the composition of the resin composition in Example 1 was changed to the composition shown in Table 6.

[Comparative Example 1 to Comparative Example 7] The same operation as in Example 1 was performed except that the composition of the resin composition in Example 1 was changed to the composition shown in Table 7, thereby obtaining the resin compositions of Comparative Examples 1 to Comparative Examples 7.

Each resin composition obtained in the above manner was processed into a tablet with a diameter of 14 mm. The obtained tablet-shaped resin composition was used as an evaluation resin composition for evaluation.

[Evaluation] 1. Burr generation inhibition The burr generation inhibition was evaluated by molding each resin composition under the condition of intentionally increasing the molding pressure of the mold. The evaluation resin composition was molded using a transfer type automatic molding machine [trade name: GP-PRO sf40, Dai-ichi Seiko Co., Ltd.] and a SOIC (Small Outline Integrated Circuit) mold [package size: 4.9mm×3.9mm, Dai-ichi Seiko Co., Ltd.] at a mold temperature of 175°C, a holding time of 60 seconds, a molding time of 180 seconds, a stroke time of 2 seconds, and a molding pressure of 10 torr (≒1.33kPa). After forming, the 10 small chambers (area A surrounded by dotted lines in Figure 1A) engraved between the package bodies adjacent to the flow channel (the so-called flow channel of the resin composition) are visually observed to confirm the presence and degree of burr generation. Then, based on the confirmation results, the burr generation inhibition is evaluated according to the following evaluation criteria. In addition, the evaluation is based on the observation results of the area with the most burrs among the 14 observed areas A. If the evaluation result is "A", "B", or "C", there is no problem in practical use. In addition, the resin composition that is least likely to generate burrs is the resin composition with an evaluation result of "A". The results are shown in Tables 1 to 7.

For reference, a photograph showing an example of an evaluation result of "A" is shown in FIG1A, and a photograph showing an example of an evaluation result of "D" is shown in FIG1B. In addition, the components represented by the same symbols in each figure refer to the same components. As shown in FIG1A, when the evaluation result is "A", no burrs are generated in the area A where 10 small chambers 30 are engraved between the package bodies 20 adjacent to the flow channel 10. On the other hand, when the evaluation result is "D", as shown in FIG1B, in the area A where 10 small chambers 30 are engraved between the package bodies 20 adjacent to the flow channel 10, it can be confirmed that burrs 40 are generated, and the burrs 40 cover the small chambers 30.

(Evaluation criteria) A: Among 10 cells, 0 or 1 cell is completely covered by burrs. B: Among 10 cells, 2 or 3 cells are completely covered by burrs. C: Among 10 cells, 4 or 5 cells are completely covered by burrs. D: Among 10 cells, 6 to 10 cells are completely covered by burrs.

2. Cleaning performance Using a transfer type automatic molding machine [trade name: GP-PRO sf40, Dai-ichi Seiko Co., Ltd.] and a QFP (Quad Flat Package) mold [package size: 28mm×28mm, Dai-ichi Seiko Co., Ltd.], the QFP was molded 400 times using semiconductor epoxy sealing material [trade name: CEL-9240 HF10, Hitachi Chemical Co., Ltd.] under the conditions of mold temperature 175°C, holding time 0.5 seconds, molding time 90 seconds, stroke time 10 seconds, and molding pressure 35 torr (≒4.67kPa), so that dirt adheres to the inner surface of the molding mold. This molding mold with dirt attached was used, and the molding time was set to 180 seconds. In addition, the molding conditions of the above-mentioned semiconductor epoxy resin sealing material (specifically, the conditions of mold temperature, holding time, molding time, stroke time, and molding pressure) were the same as those for the molding of the embodiment and the comparative example, and the molding mold was cleaned. Then, the number of moldings required to completely remove the dirt attached to the inner surface of the molding mold (hereinafter also referred to as "number") was measured, and this number was used as an indicator for evaluating the cleaning performance of the resin composition. Whether the dirt was completely removed was judged by visual confirmation. The number of repetitions required to completely remove the dirt attached to the inner surface of the forming mold (i.e., the number of times) indicates better cleaning performance. If the number of times is 3 or less, there is no problem in practical use. In addition, for the situation where the resin composition does not spread to every corner inside the forming mold, the so-called unfilled situation is evaluated as "NG" and judged to have no cleaning performance. The results are shown in Tables 1 to 7.

3. Flowability Flowability is an indicator of the fluidity of a resin composition, and can be judged using the value of the spiral flow length. In this evaluation, the spiral flow length (unit: cm) of the resin composition was measured using the method in accordance with ASTM D-3123. Specifically, a transfer molding machine [Model: MF-O70, techno marushichi (stock)] was used to measure the spiral flow length when the evaluation resin composition was injected into the flow path of the spiral flow measurement mold specified in ASTM D-3123 at a mold temperature of 175°C, a clamping pressure of 17.5Mpa, and a transfer pressure of 1.96Mpa. Then, based on the measured spiral flow length value, the fluidity of the resin composition is evaluated according to the following evaluation criteria. The larger the spiral flow length value, the higher the fluidity of the resin composition. If the spiral flow length is 35cm~75cm, there is no problem in practical use. The results are shown in Tables 1~7.

4. Free formaldehyde concentration The free formaldehyde concentration is determined by the sodium sulfite method. Specifically, the following method is used for determination. Add 3 drops of rhodic acid solution to 50 mL of 0.5 mol/L (liter; the same applies below) sodium sulfite aqueous solution to obtain a reddish brown solution. The reddish brown color comes from the color of rhodic acid. Then, use a burette to add 0.1 mol/L hydrochloric acid aqueous solution to the obtained reddish brown solution to make the reddish brown color disappear. Then, add 2 g of the evaluation resin composition to the solution that has disappeared the reddish brown color, and stir to obtain a pinkish turbid solution. Then, a 0.1 mol/L hydrochloric acid aqueous solution was added dropwise to the pink turbid solution using a burette, and the free formaldehyde concentration was calculated based on the amount of hydrochloric acid aqueous solution added until the pink color of the solution disappeared (the so-called titration amount) according to the following formula. The results are shown in Table 1, Table 3, and Table 7.

Free formaldehyde concentration [unit: mass %] = (H×F×C×30.03)/S H [unit: ml]: titration of 0.1 mol/L hydrochloric acid aqueous solution F: potency of 0.1 mol/L hydrochloric acid aqueous solution C [unit: mol/L]: concentration of hydrochloric acid aqueous solution S [unit: g]: amount of evaluation resin composition 30.03: formula weight of formaldehyde

[Table 1] Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Embodiment 5 Embodiment 6 Embodiment 7 Embodiment 8 Embodiment 9 Embodiment 10 Embodiment 11 Composition [mass] Melamine resin or melamine resin + organic filler Melamine-formaldehyde resin containing pulp 30 30 30 30 30 30 30 30 30 30 30 Melamine-formaldehyde resin (S-166) 50 50 50 50 50 50 50 50 50 50 50 Melamine-formaldehyde resin (S-176) - - - - - - - - - - - Inorganic fillers Silicon oxide 20 20 20 20 20 20 20 20 20 20 20 Amount relative to 100 parts by mass of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] Acidic compounds benzoic acid 0.12 0.12 0.12 0.12 0.12 0.12 - - - - - tartaric acid - - - - - - 0.12 0.12 - - - Hydrochloric acid - - - - - - - - 0.12 - - Sulfamic acid - - - - - - - - - 0.12 - Trimellitic acid - - - - - - - - - - 0.12 Specific imide compounds Phthalimide 1.00 - - - - - - - - - - Succinimide - 1.00 - - - 0.50 0.50 0.50 0.50 0.50 0.50 Cis-1,2,3,6-Tetrahydrophthalimide - - 1.00 - - - - - - - - 1,2,3,6-Tetrahydrophthalimide - - - 1.00 - - - - - - - 1,2-Cyclohexanedicarboxylic acid imide - - - - 1.00 - - - - - - Specific urea compounds Urea - - - - - - - - - - - 1-Methylurea - - - - - - - - - - - 1-Ethylurea - - - - - - - - - - - 1,1-Dimethylurea - - - - - - - - - - - 1,3-Dimethylurea - - - - - - - - - - - Comparison compounds Urea resin (trade name: Leadlite) - - - - - - - - - - - Monoethanolamine - - - - - - - - - - - Metal Soap Zinc stearate 1.13 1.13 1.13 1.13 1.13 1.13 1.13 - 1.13 1.13 1.13 Zinc myristic acid - - - - - - - 1.13 - - - Lubricant Ethylene Distearate 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 Total content of acidic compounds, specific imide compounds, and specific urea compounds relative to 100 parts by mass of the total of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] 1.12 1.12 1.12 1.12 1.12 0.62 0.62 0.62 0.62 0.62 0.62 Ratio of the total content of specific imide compounds and specific urea compounds to the content of acidic compounds 8.33 8.33 8.33 8.33 8.33 4.17 4.17 4.17 4.17 4.17 4.17 Reviews Burrs inhibit A A B B B A A A B A A Cleaning performance 3 2 2 2 2 2 2 2 3 3 2 Liquidity 55 58 56 57 56 53 54 53 48 53 52 Free formaldehyde concentration [mass %] 0.09 0.07 0.07 0.07 0.08 - - - - - -

[Table 2] Embodiment 12 Embodiment 13 Embodiment 14 Embodiment 15 Embodiment 16 Embodiment 17 Embodiment 18 Composition [mass] Melamine resin or melamine resin + organic filler Melamine-formaldehyde resin containing pulp 30 30 30 30 30 30 30 Melamine-formaldehyde resin (S-166) 50 50 50 50 50 50 50 Melamine-formaldehyde resin (S-176) - - - - - - - Inorganic fillers Silicon oxide 20 20 20 20 20 20 20 Amount relative to 100 parts by mass of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] Acidic compounds benzoic acid 0.12 0.13 0.12 0.12 0.08 0.10 0.12 tartaric acid - - - - - 0.10 - Hydrochloric acid - - - - - - - Sulfamic acid - - - - - - - Trimellitic acid - - - - - - - Specific imide compounds Phthalimide - - 0.10 1.00 0.02 - - Succinimide 5.88 6.40 - 1.00 - 0.02 0.50 Cis-1,2,3,6-Tetrahydrophthalimide - - - - - - - 1,2,3,6-Tetrahydrophthalimide - - - - - - - 1,2-Cyclohexanedicarboxylic acid imide - - - - - - - Specific urea compounds Urea - - - - - - 0.50 1-Methylurea - - - - - - - 1-Ethylurea - - - - - - - 1,1-Dimethylurea - - - - - - - 1,3-Dimethylurea - - - - - - - Comparison compounds Urea resin (trade name: Leadlite) - - - - - - - Monoethanolamine - - - - - - - Metal Soap Zinc stearate 1.13 1.13 1.13 1.13 1.13 1.13 1.13 Zinc myristic acid - - - - - - - Lubricant Ethylene Distearate 0.36 0.36 0.36 0.36 0.36 0.36 0.36 Total content of acidic compounds, specific imide compounds, and specific urea compounds relative to 100 parts by mass of the total of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] 6.00 6.53 0.22 2.12 0.10 0.22 1.12 Ratio of the total content of specific imide compounds and specific urea compounds to the content of acidic compounds 49.00 49.23 0.83 16.67 0.25 0.10 8.33 Reviews Burrs inhibit C C B B C C A Cleaning performance 3 3 3 3 3 3 2 Liquidity 66 68 53 56 44 40 58 Free formaldehyde concentration [mass %] - - - - - - -

[table 3] Embodiment 19 Embodiment 20 Embodiment 21 Embodiment 22 Embodiment 23 Embodiment 24 Embodiment 25 Embodiment 26 Embodiment 27 Embodiment 28 Embodiment 29 Composition [mass] Melamine resin or melamine resin + organic filler Melamine-formaldehyde resin containing pulp 30 30 30 30 30 30 30 30 30 30 30 Melamine-formaldehyde resin (S-166) 50 50 50 50 50 50 50 50 50 50 50 Melamine-formaldehyde resin (S-176) - - - - - - - - - - - Inorganic fillers Silicon oxide 20 20 20 20 20 20 20 20 20 20 20 Amount relative to 100 parts by mass of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] Acidic compounds benzoic acid 0.12 0.12 0.12 0.12 0.12 0.12 - - - - - tartaric acid - - - - - - 0.12 0.12 - - - Hydrochloric acid - - - - - - - - 0.12 - - Sulfamic acid - - - - - - - - - 0.12 - Trimellitic acid - - - - - - - - - - 0.12 Specific imide compounds Phthalimide - - - - - - - - - - - Succinimide - - - - - - - - - - - Cis-1,2,3,6-Tetrahydrophthalimide - - - - - - - - - - - 1,2,3,6-Tetrahydrophthalimide - - - - - - - - - - - 1,2-Cyclohexanedicarboxylic acid imide - - - - - - - - - - - Specific urea compounds Urea 2.00 - - - - - - - - - - 1-Methylurea - 2.00 - - - - - - - - - 1-Ethylurea - - 2.00 - - - - - - - - 1,1-Dimethylurea - - - 2.00 - - - - - - - 1,3-Dimethylurea - - - - 2.00 0.50 0.50 0.50 0.50 0.50 0.50 Comparison compounds Urea resin (trade name: Leadlite) - - - - - - - - - - - Monoethanolamine - - - - - - - - - - - Metal Soap Zinc stearate 1.13 1.13 1.13 1.13 1.13 1.13 1.13 - 1.13 1.13 1.13 Zinc myristic acid - - - - - - - 1.13 - - - Lubricant Ethylene Distearate 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 Total content of acidic compounds, specific imide compounds, and specific urea compounds relative to 100 parts by mass of the total of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] 2.12 2.12 2.12 2.12 2.12 0.62 0.62 0.62 0.62 0.62 0.62 Ratio of the total content of specific imide compounds and specific urea compounds to the content of acidic compounds 16.67 16.67 16.67 16.67 16.67 4.17 4.17 4.17 4.17 4.17 4.17 Reviews Burrs inhibit B B B B A A A A B A A Cleaning performance 3 3 3 2 2 3 3 3 3 3 2 Liquidity 59 62 61 61 62 56 54 54 55 55 55 Free formaldehyde concentration [mass %] 0.05 0.06 0.06 0.05 0.05 - - - - - -

[Table 4] Embodiment 30 Embodiment 31 Embodiment 32 Embodiment 33 Embodiment 34 Embodiment 35 Embodiment 36 Embodiment 37 Embodiment 38 Embodiment 39 Composition [mass] Melamine resin or melamine resin + organic filler Melamine-formaldehyde resin containing pulp 30 30 30 30 30 30 30 30 30 30 Melamine-formaldehyde resin (S-166) - - - - - 50 50 50 50 50 Melamine-formaldehyde resin (S-176) 50 50 50 50 50 - - - - - Inorganic fillers Silicon oxide 20 20 20 20 20 20 20 20 20 20 Amount relative to 100 parts by mass of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] Acidic compounds benzoic acid - - - - - 0.12 0.13 0.08 0.12 0.20 tartaric acid 0.12 0.12 - - - - - - - - Hydrochloric acid - - 0.12 - - - - - - - Sulfamic acid - - - 0.12 - - - - - - Trimellitic acid - - - - 0.12 - - - - - Specific imide compounds Phthalimide - - - - - - - - - - Succinimide - - - - - - - - - - Cis-1,2,3,6-Tetrahydrophthalimide - - - - - - - - - - 1,2,3,6-Tetrahydrophthalimide - - - - - - - - - - 1,2-Cyclohexanedicarboxylic acid imide - - - - - - - - - - Specific urea compounds Urea - - - - - - - - 1.00 - 1-Methylurea - - - - - - - - - - 1-Ethylurea - - - - - - - - - - 1,1-Dimethylurea - - - - - - - - - - 1,3-Dimethylurea 0.50 0.50 0.50 0.50 0.50 5.58 6.40 0.02 1.00 0.02 Comparison compounds Urea resin (trade name: Leadlite) - - - - - - - - - - Monoethanolamine - - - - - - - - - - Metal Soap Zinc stearate 1.13 - 1.13 1.13 1.13 1.13 1.13 1.13 1.13 1.13 Zinc myristic acid - 1.13 - - - - - - - - Lubricant Ethylene Distearate 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 Total content of acidic compounds, specific imide compounds, and specific urea compounds relative to 100 parts by mass of the total of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] 0.62 0.62 0.62 0.62 0.62 5.70 6.53 0.10 2.12 0.22 Ratio of the total content of specific imide compounds and specific urea compounds to the content of acidic compounds 4.17 4.17 4.17 4.17 4.17 46.50 49.23 0.25 16.67 0.10 Reviews Burrs inhibit A A B A A C C C B C Cleaning performance 3 3 3 3 2 3 3 3 3 3 Liquidity 53 52 56 54 56 71 75 51 64 43 Free formaldehyde concentration [mass %] - - - - - - - - - -

[table 5] Embodiment 40 Embodiment 41 Embodiment 42 Embodiment 43 Embodiment 44 Composition [mass] Melamine resin or melamine resin + organic filler Melamine-formaldehyde resin containing pulp 30 30 30 30 30 Melamine-formaldehyde resin (S-166) 50 50 50 50 50 Melamine-formaldehyde resin (S-176) - - - - - Inorganic fillers Silicon oxide 20 20 20 20 20 Amount relative to 100 parts by mass of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] Acidic compounds benzoic acid 0.12 0.13 0.08 0.12 0.20 tartaric acid - - - - - Hydrochloric acid - - - - - Sulfamic acid - - - - - Trimellitic acid - - - - - Specific imide compounds Phthalimide - - - - - Succinimide - - - - - Cis-1,2,3,6-Tetrahydrophthalimide - - - - - 1,2,3,6-Tetrahydrophthalimide - - - - - 1,2-Cyclohexanedicarboxylic acid imide - - - - - Specific urea compounds Urea - - - 1.00 - 1-Methylurea - - - - - 1-Ethylurea - - - - - 1,1-Dimethylurea - - - - - 1,3-Dimethylurea 5.58 6.40 0.02 1.00 0.02 Comparison compounds Urea resin (trade name: Leadlite) - - - - - Monoethanolamine - - - - - Metal Soap Zinc stearate 1.13 1.13 1.13 1.13 1.13 Zinc myristic acid - - - - - Lubricant Ethylene Distearate 0.36 0.36 0.36 0.36 0.36 Total content of acidic compounds, specific imide compounds, and specific urea compounds relative to 100 parts by mass of the total of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] 5.70 6.53 0.10 2.12 0.22 Ratio of the total content of specific imide compounds and specific urea compounds to the content of acidic compounds 46.50 49.23 0.25 16.67 0.10 Reviews Burrs inhibit C C C B C Cleaning performance 3 3 3 3 3 Liquidity 71 75 51 64 43 Free formaldehyde concentration [mass %] - - - - -

[Table 6] Embodiment 45 Embodiment 46 Embodiment 47 Embodiment 48 Embodiment 49 Embodiment 50 Embodiment 51 Embodiment 52 Embodiment 53 Composition [mass] Melamine resin or melamine resin + organic filler Melamine-formaldehyde resin containing pulp 30 30 30 30 30 30 30 30 30 Melamine-formaldehyde resin (S-166) 50 50 50 50 50 50 50 50 50 Melamine-formaldehyde resin (S-176) - - - - - - - - - Inorganic fillers Silicon oxide 20 20 20 20 20 20 20 20 20 Amount relative to 100 parts by mass of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] Acidic compounds benzoic acid 0.01 0.02 0.03 1.00 3.00 5.00 0.01 0.03 5.00 tartaric acid - - - - - - - - - Hydrochloric acid - - - - - - - - - Sulfamic acid - - - - - - - - - Trimellitic acid - - - - - - - - - Specific imide compounds Phthalimide - - - - - - - - - Succinimide 1.00 1.50 2.00 4.00 4.00 7.00 - - - Cis-1,2,3,6-Tetrahydrophthalimide - - - - - - - - - 1,2,3,6-Tetrahydrophthalimide - - - - - - - - - 1,2-Cyclohexanedicarboxylic acid imide - - - - - - - - - Specific urea compounds Urea - - - - - - - - - 1-Methylurea - - - - - - - - - 1-Ethylurea - - - - - - - - - 1,1-Dimethylurea - - - - - - - - - 1,3-Dimethylurea - - - - - - 1.00 2.00 7.00 Comparison compounds Urea resin (trade name: Leadlite) - - - - - - - - - Monoethanolamine - - - - - - - - - Metal Soap Zinc stearate 1.13 1.13 1.13 1.13 1.13 1.13 1.13 1.13 1.13 Zinc myristic acid - - - - - - - - - Lubricant Ethylene Distearate 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 Total content of acidic compounds, specific imide compounds, and specific urea compounds relative to 100 parts by mass of the total of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] 1.01 1.52 2.03 5.00 7.00 12.00 1.01 2.03 12.00 Ratio of the total content of specific imide compounds and specific urea compounds to the content of acidic compounds 100.00 75.00 66.67 4.00 1.33 1.40 100.00 66.67 1.40 Reviews Burrs inhibit C C B B C C C B C Cleaning performance 3 2 2 2 3 3 2 2 3 Liquidity 74 70 66 53 45 40 67 64 42 Free formaldehyde concentration [mass %] - - - - - - - - -

[Table 7] Comparison Example 1 Comparison Example 2 Comparison Example 3 Comparison Example 4 Comparison Example 5 Comparison Example 6 Comparison Example 7 Composition [mass] Melamine resin or melamine resin + organic filler Melamine-formaldehyde resin containing pulp 30 30 30 30 30 30 30 Melamine-formaldehyde resin (S-166) 50 50 50 50 50 50 50 Melamine-formaldehyde resin (S-176) - - - - - - - Inorganic fillers Silicon oxide 20 20 20 20 20 20 20 Amount relative to 100 parts by mass of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] Acidic compounds benzoic acid 0.12 0.12 0.12 0.12 15.00 0.10 0.10 tartaric acid - - - - - - - Hydrochloric acid - - - - - - - Sulfamic acid - - - - - - - Trimellitic acid - - - - - - - Specific imide compounds Phthalimide - - - - - - - Succinimide - - - - 0.10 15.00 12.00 Cis-1,2,3,6-Tetrahydrophthalimide - - - - - - - 1,2,3,6-Tetrahydrophthalimide - - - - - - - 1,2-Cyclohexanedicarboxylic acid imide - - - - - - - Specific urea compounds Urea - - - - - - - 1-Methylurea - - - - - - - 1-Ethylurea - - - - - - - 1,1-Dimethylurea - - - - - - - 1,3-Dimethylurea - - - - - - - Comparison compounds Urea resin (trade name: Leadlite) - - 2.00 - - - - Monoethanolamine - 1.00 - 2.00 - - - Metal Soap Zinc stearate 1.13 1.13 1.13 1.13 1.13 1.13 1.13 Zinc myristic acid - - - - - - - Lubricant Ethylene Distearate 0.36 0.36 0.36 0.36 0.36 0.36 0.36 Total content of acidic compounds, specific imide compounds, and specific urea compounds relative to 100 parts by mass of the total of melamine resin and fillers (organic fillers + inorganic fillers) [parts by mass] - - - - 15.10 15.10 12.10 Ratio of the total content of specific imide compounds and specific urea compounds to the content of acidic compounds - - - - 0.007 150.00 120.00 Reviews Burrs inhibit D D D D D D D Cleaning performance 4 5 5 5 NG 5 5 Liquidity 39 65 39 74 10 94 91 Free formaldehyde concentration [mass %] 0.15 - - - - - -

In Tables 1 to 7, "-" in the composition column means that the component corresponding to the column is not contained. In Tables 1 to 7, the values of the acidic compound, specific imide compound, specific urea compound, comparative compound, metal soap, and lubricant composition columns show the amount (mass parts) relative to 100 mass parts of the total of melamine resin and filler (organic filler + inorganic filler). In Table 7, the "-" in the column "Total content of acidic compounds, specific imide compounds, and specific urea compounds relative to 100 parts by mass of the total of melamine resin and filler (organic filler + inorganic filler)" and the column "Ratio of the total content of specific imide compounds and specific urea compounds relative to the content of acidic compounds" means that the acidic compound, which is an essential component of the resin composition disclosed in the present invention, is not contained, so the value is not calculated. In Tables 1 to 7, the "-" in the evaluation column means that the evaluation in the corresponding column was not performed.

The detailed description of each component listed in Table 1 to Table 7 is as follows. <Melamine resin + organic filler> "Melamine-formaldehyde resin containing paper pulp" [Production example A] <Melamine resin> "Melamine-formaldehyde resin (S-166)" [Trade name: Nikaresin (registered trademark) S-166, NIPPON CARBIDE INDUSTRIES (Co., Ltd.)] "Melamine-formaldehyde resin (S-176)" [Trade name: Nikaresin (registered trademark) S-176, NIPPON CARBIDE INDUSTRIES (Co., Ltd.)] <Inorganic filler> "Silicon oxide" [Trade name: pure silica powder, crystalline silicon dioxide, Seto Kiln Industry Raw Materials (Co., Ltd.)]

<Acidic compounds> "Benzoic acid" [Fuji Film & Wako Pure Chemicals, monocarboxylic acid] "Tartaric acid" [Fuji Film & Wako Pure Chemicals, dicarboxylic acid] "Hydrochloric acid" [Fuji Film & Wako Pure Chemicals, Ltd.] "Sulfonic acid" [Fuji Film & Wako Pure Chemicals, Ltd.] "Trimellitate" [Fuji Film & Wako Pure Chemicals, tricarboxylic acid]

<Specific imide compounds> "Oxyphenylenediamine" [Molecular weight: 147, Tokyo Chemical Industry Co., Ltd.] "Succinimide" [Molecular weight: 99, Tokyo Chemical Industry Co., Ltd.] "Cis-1,2,3,6-tetrahydroxyphenylenediamine" [Molecular weight: 151, cis isomer, Tokyo Chemical Industry Co., Ltd.] "1,2,3,6-tetrahydroxyphenylenediamine" [Molecular weight: 151, mixture of cis and trans isomers, Fuji Films Co., Ltd. and Koshin Chemical Co., Ltd.] "1,2-Cyclohexanedicarboxylic acid imide" [Molecular weight: 153, Tokyo Chemical Industry Co., Ltd.] <Specific urea Compounds> "Urea" [Molecular weight: 60, Tokyo Chemical Industry Co., Ltd.] "1-Methylurea" [Molecular weight: 74, Tokyo Chemical Industry Co., Ltd.] "1-Ethylurea" [Molecular weight: 88, Tokyo Chemical Industry Co., Ltd.] "1,1-Dimethylurea" [Molecular weight: 88, Tokyo Chemical Industry Co., Ltd.] "1,3-Dimethylurea" [Molecular weight: 88, Tokyo Chemical Industry Co., Ltd.] <Comparative compounds> "Urea resin (trade name: Leadlite)" [Weight average molecular weight: 800, Taiwa Co., Ltd.] "Monoethanolamine" [Fuji Films Wako Pure Chemical Industries, Ltd.]

<Metallic soap> "Zinc stearate" [Trade name: ZINC STEARATE GF200, NOF Corporation] "Zinc myristic acid" [Trade name: POWDERBASE M, NOF Corporation] <Lubricant> "Ethylene distearamide" [Trade name: ALFLOW (registered trademark) H50T, NOF Corporation]

As shown in Tables 1 to 6, the resin compositions of Examples 1 to 53 are not prone to burrs and have excellent cleaning performance. In addition, the resin compositions of Examples 1 to 53 exhibit appropriate fluidity. In addition, from the comparison with the resin composition of Comparative Example 1, it can be seen that the amount of formaldehyde generated in the resin compositions of Examples 1 to 5 and Examples 19 to 23 is reduced.

On the other hand, as shown in Table 7, the resin compositions of Comparative Examples 1 to 4 that do not contain specific imide compounds and specific urea compounds are prone to burrs and have poor cleaning performance compared to the resin compositions of the examples. In addition, the resin composition of Comparative Example 5 in which the total content of the specific imide compound and the specific urea compound relative to the content of the acidic compound is less than 0.01, and the resin compositions of Comparative Examples 6 and 7 in which the total content is greater than 100.0 are prone to burrs and have poor cleaning performance compared to the resin compositions of the examples. The resin composition of Comparative Example 3, which contains a urea resin instead of a specific urea compound, generates significantly burrs and has significantly poorer cleaning performance than the resin composition of the Example containing a specific urea compound. The reason is presumably because if the resin composition contains a urea resin, a condensation reaction between the urea resin and the melamine-based resin occurs first, and the urea resin is incorporated into the crosslinking structure, and does not become a resin composition with appropriate viscosity as in the case of containing a specific urea compound.

10: Runner 20: Package 30: Chamber 40: Burr A: Area

[FIG. 1A] is a photograph showing an example in which the evaluation result of the inhibition of burr generation in the embodiment is "A". [FIG. 1B] is a photograph showing an example in which the evaluation result of the inhibition of burr generation in the embodiment is "D".

Claims (8)

A resin composition for mold cleaning, comprising: melamine resin, filler, acidic compound, and at least one compound selected from the group consisting of an imide compound with a molecular weight of 500 or less and a urea compound with a molecular weight of 500 or less; the acidic compound is a compound different from the imide compound; the ratio of the total mass content of the imide compound and the urea compound to the mass content of the acidic compound falls within the range of 0.01 or more and 100.0 or less. The mold cleaning resin composition of claim 1, wherein the total content of the acidic compound, the imide compound, and the urea compound is within the range of 0.1 parts by mass or more and 12.0 parts by mass or less relative to 100 parts by mass of the total of the melamine resin and the filler. A mold cleaning resin composition as claimed in claim 1 or 2, wherein the imide compound is at least one selected from the group consisting of o-xylylenediamine, succinimide, pyromelite imide, 1,2,3,6-tetrahydroxylylenediamine, and 1,2-cyclohexanedicarboxylic acid imide, and the urea compound is at least one selected from the group consisting of urea, 1-methylurea, 1-ethylurea, 1,1-dimethylurea, and 1,3-dimethylurea. The mold cleaning resin composition of claim 1 or 2, wherein the acidic compound is a compound having a carboxyl group. The mold cleaning resin composition of claim 1 or 2, wherein the acidic compound is at least one selected from the group consisting of benzoic acid, tartaric acid, hydrochloric acid, sulfamic acid, and trimellitic acid. The mold cleaning resin composition of claim 1 or 2, wherein the content of the acidic compound is within a range of 0.01 parts by mass or more and 5.0 parts by mass or less relative to 100 parts by mass of the total of the melamine resin and the filler. The mold cleaning resin composition of claim 1 or 2 contains metal soap. The mold cleaning resin composition as claimed in claim 1 or 2 contains a lubricant.