Resin composition for mold cleaning

Abstract

A resin composition for mold cleaning, comprising a melamine-based resin, a filler, an acidic compound, and at least one compound selected from an imide compound having a molecular weight of 500 or less and a urea compound having a molecular weight of 500 or less, wherein the acidic compound is different from the imide compound, and the ratio of the total mass of the imide compound and the urea compound to the mass of the acidic compound is in a range of 0.01 to 100.0.

Description

Technical Field

[0001] The present invention relates to a resin composition for cleaning molds. Background Art

[0002] In recent years, the increasing functionality of mobile devices, such as smartphones, has led to a continuous miniaturization of semiconductors. Furthermore, the widespread adoption of robots to address labor shortages and reduce costs, coupled with the rapid electrification of automobiles, has led to a dramatic increase in the variety and quantity of semiconductors used, and the frequency of semiconductor upgrades has also increased. This trend has led to the widespread use of molds capable of handling multi-cavity designs in packages and the increasing complexity of semiconductor patterns.

[0003] Along with the requirement of efficiency of the molding operation of semiconductor sealing resin in recent years, for the resin composition (so-called mold cleaning resin composition) for cleaning the molding die, also require efficiency of the cleaning operation.In order to effectively carry out the cleaning operation of the molding die, it is preferred that the mold cleaning resin composition shows high fluidity such as rapidly diffused to every corner inside the molding die.There are several reports on the method for controlling the fluidity of the mold cleaning resin composition.

[0004] For example, Japanese Patent Application Laid-Open No. 2019-126966 uses a blocked carboxylic acid as a curing agent for a melamine-based resin to achieve a mold cleaning resin composition that exhibits the fluidity required to diffuse into every corner inside a molding mold (so-called appropriate fluidity) even at low temperatures.

[0005] In addition, Japanese Patent Application Laid-Open No. 2017-177623 realizes a mold cleaning resin composition that achieves a balance between curing and fluidity by using a plurality of curing catalysts.

[0006] In addition, in International Publication No. 2013 / 011876, by using an inorganic filler having an average particle size, a standard deviation of the particle size, an average aspect ratio of the particle size, and a standard deviation of the aspect ratio of the particle size within specific ranges, a resin composition for mold cleaning that exhibits good fluidity and can diffuse into every corner of the voids inside the mold is achieved. Summary of the Invention

[0007] In forming die, along with the complication development of multi-cavity design, miniaturization and pattern, only controlling the fluidity of mold cleaning resin composition is difficult to make mold cleaning resin composition diffuse into every corner inside forming die.Therefore, taken to improve the speed, pressure and other countermeasures of the plunger that mold cleaning resin composition is punched into the mold.But according to this countermeasure, when cleaning forming die, mold cleaning resin composition can invade the gaps such as the mating surface, friction surface of forming die, easily produce burr.If produce burr, then when semiconductor sealing resin is molded, can produce the bad situation such as workability reduction, molding pollution, molding quality unevenness.

[0008] Therefore, the resin composition for mold cleaning is required to have excellent cleaning performance and be less likely to generate burrs.

[0009] Regarding the above viewpoint, Japanese Patent Application Laid-Open No. 2019-126966, Japanese Patent Application Laid-Open No. 2017-177623, and International Publication No. 2013 / 011876 do not pay any attention to the problem of burr generation in the resin composition for mold cleaning.

[0010] An embodiment of the present disclosure aims to provide a resin composition for cleaning a mold that is less likely to generate burrs and has excellent cleaning performance.

[0011] Specific methods for solving the problem include the following.

[0012] <1> A mold cleaning resin composition comprising a melamine-based resin, a filler, an acidic compound, and at least one compound selected from an imide compound having a molecular weight of 500 or less and a urea compound having a molecular weight of 500 or less, wherein the acidic compound is different from the imide compound, and the ratio of the total mass of the imide compound and the urea compound to the mass of the acidic compound is in the range of 0.01 to 100.0.

[0013] <2> The mold cleaning resin composition according to <1>, wherein the total content of the acidic compound, the imide compound, and the urea compound is in the range of 0.1 to 12.0 parts by mass per 100 parts by mass of the total of the melamine resin and the filler.

[0014] <3> The mold cleaning resin composition according to <1> or <2>, wherein the imide compound is at least one selected from phthalimide, succinimide, pyromellitimide, 1,2,3,6-tetrahydrophthalimide, and 1,2-cyclohexanedicarboximide, and the urea compound is at least one selected from urea, 1-methylurea, 1-ethylurea, 1,1-dimethylurea, and 1,3-dimethylurea.

[0015] <4> The mold cleaning resin composition according to any one of <1> to <3>, wherein the acidic compound is a compound having a carboxyl group.

[0016] <5> The mold cleaning resin composition according to any one of <1> to <3>, wherein the acidic compound is at least one selected from benzoic acid, tartaric acid, hydrochloric acid, sulfamic acid, and trimellitic acid.

[0017] <6> The mold cleaning resin composition according to any one of <1> to <5>, wherein the content of the acidic compound is in the range of 0.01 to 5.0 parts by mass based on 100 parts by mass of the total of the melamine resin and the filler.

[0018] <7> The mold cleaning resin composition according to any one of <1> to <6>, further comprising a metal soap.

[0019] <8> The mold cleaning resin composition according to any one of <1> to <7>, further comprising a lubricant.

[0020] According to one embodiment of the present disclosure, a resin composition for cleaning a mold that is less likely to generate burrs and has excellent cleaning performance is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1A This is a photograph showing an example of the evaluation result "A" of the burr generation suppression in the example.

[0022] Figure 1B This is a photograph showing an example of the evaluation result "D" of the burr generation suppression in the example. DETAILED DESCRIPTION

[0023] Hereinafter, specific embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the purpose of the present disclosure.

[0024] In the present disclosure, a numerical range expressed using “to” indicates a range including the numerical values ​​described before and after “to” as the minimum value and the maximum value, respectively.

[0025] In the numerical ranges described in this disclosure, the upper limit or lower limit described in a certain numerical range may be replaced by the upper limit or lower limit of the numerical range described in another stage. In addition, in the numerical ranges described in this disclosure, the upper limit or lower limit described in a certain numerical range may be replaced by the values ​​shown in the examples.

[0026] In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.

[0027] In the present disclosure, when there are plural substances corresponding to each component, the amount of each component refers to the total amount of the plural substances unless otherwise specified.

[0028] In the present disclosure, the “inner surface of a molding die” refers to a region that comes into contact with an object to be molded by the molding die.

[0029] [Resin composition for mold cleaning]

[0030] The mold cleaning resin composition disclosed herein (hereinafter also referred to as the "resin composition") comprises a melamine-based resin, a filler, an acidic compound, and at least one compound selected from an imide compound having a molecular weight of 500 or less (hereinafter also referred to as a "specific imide compound") and a urea compound having a molecular weight of 500 or less (hereinafter also referred to as a "specific urea compound"), wherein the acidic compound is a compound different from the specific imide compound, and the ratio of the total mass content of the specific imide compound and the specific urea compound to the mass content of the acidic compound is in the range of 0.01 to 100.0.

[0031] Hereinafter, in this disclosure, a specific imide compound and a specific urea compound may be collectively referred to as a “specific compound”.

[0032] The curing reaction in the mold cleaning resin composition comprising a melamine resin and a curing catalyst is carried out as follows. 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, and the mold cleaning resin composition solidifies. Generally, the curing rate 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 rate of the mold cleaning resin composition becomes faster and the fluidity decreases. In the mold, with the progress of multi-cavity design, miniaturization and complexity of patterns, it is difficult to control the fluidity of the mold cleaning resin composition by only adjusting the content of the curing catalyst. In addition, it is difficult to make the mold cleaning resin composition diffuse into every corner inside the forming mold by only controlling the fluidity of the mold cleaning resin composition. Therefore, in recent years, countermeasures such as the speed and pressure of the plunger that increases the mold cleaning resin composition to be punched into the mold have been taken. However, according to these countermeasures, when cleaning the forming mold, the mold cleaning resin composition invades the gaps such as the mating surface and friction surface of the forming mold, which easily produces burrs. If burrs are generated, problems such as reduced workability during molding of a semiconductor sealing resin, contamination of a molded product, and uneven quality of the molded product may occur.

[0033] In contrast, the mold cleaning resin composition of the present disclosure 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 mass ratio. Therefore, burrs are less likely to be generated when cleaning a molding mold and the cleaning performance is excellent.

[0034] The reason why the mold cleaning resin composition of the present disclosure can achieve such an effect is not yet clear, but the present inventors have made the following assumptions. However, the following assumptions are not intended to limit the mold cleaning resin composition of the present disclosure, but are provided as an example.

[0035] In the mold cleaning resin composition disclosed herein, it is believed that the acidic compound plays a role in accelerating the curing speed, and on the other hand, specific imide compounds and specific urea compounds play a role in delaying the curing speed. Therefore, if the mold cleaning resin composition disclosed herein is heated, it is believed that the cured product with a larger molecular weight (in other words, a long molecular chain) coexists with the cured product with a smaller molecular weight (in other words, a short molecular chain). It is speculated that the cured products with different molecular weights are appropriately entangled with each other, suppressing excessive viscosity reduction, thereby making the fluidity of the mold cleaning resin composition appropriate, as a result, suppressing the mold cleaning resin composition from invading the gap of the forming mold, suppressing the generation of burrs. In addition, it is believed that the fluidity of the mold cleaning resin composition becomes appropriate, and the mold cleaning resin composition diffuses to every corner inside the forming mold, therefore effectively playing the excellent cleaning performance based on melamine resin.

[0036] Although the detailed mechanism is not yet clear, the mold cleaning resin composition disclosed herein can achieve the effect of reducing the amount of formaldehyde that may be generated during molding.

[0037] <Melamine resin>

[0038] The resin composition of the present disclosure includes a melamine-based resin.

[0039] In the resin composition of the present disclosure, the melamine-based resin contributes to cleaning performance.

[0040] Melamine-based resins have highly polar methylol groups. It is believed that in resin compositions containing melamine-based resins, the highly polar methylol groups of the melamine-based resins act against stains (hereinafter also referred to as "contaminants") originating from sealing molding materials containing thermosetting resins, such as epoxy resins, thereby achieving a cleaning effect.

[0041] In the present disclosure, the “melamine-based resin” refers to at least one selected from the group consisting of a melamine resin, a melamine-phenol co-condensate, and a melamine-urea co-condensate.

[0042] Melamine resin is a condensation product of a triazine compound and an aldehyde compound.

[0043] Examples of the triazine compound include melamine, benzoguanamine, and acetoguanamine.

[0044] Examples of the aldehyde compound include formaldehyde, paraformaldehyde, and acetaldehyde.

[0045] The melamine resin preferably has a molar ratio of the repeating unit derived from the triazine compound to the repeating unit derived from the aldehyde compound (repeating unit derived from the triazine compound / repeating unit derived from the aldehyde compound) of 1 / 1.2 to 1 / 4.

[0046] Melamine-phenol co-condensate is a co-condensate of a triazine compound, a phenol compound and an aldehyde compound.

[0047] Examples of the phenol compound include phenol, cresol, xylenol, ethylphenol, and butylphenol.

[0048] The melamine-phenol co-condensate preferably has a molar ratio of the repeating unit derived from the triazine compound to the repeating unit derived from the phenol compound (repeating unit derived from the triazine compound / repeating unit derived from the phenol compound) of 1 / 0.3 to 1 / 1.

[0049] In the melamine-phenol co-condensate, the molar ratio of the repeating unit derived from the triazine compound to the repeating unit derived from the aldehyde compound (repeating unit derived from the triazine compound / repeating unit derived from the aldehyde compound) is preferably 1 / 1 to 1 / 3.

[0050] Melamine-urea co-condensate is a co-condensate of a triazine compound, a urea compound, and an aldehyde compound.

[0051] Examples of the urea compound include urea, thiourea, and ethylene urea.

[0052] Melamine-based resins can be produced by known methods.

[0053] For example, a melamine resin can be produced by stirring melamine crystals and formaldehyde at a molar ratio (melamine crystals / formaldehyde) of 1 / 1.2 to 1 / 4, heating at 70°C to 100°C, and pH 7 to 7.5, followed by cooling and reaction at 60°C until a 3% by mass aqueous solution of the reactant becomes turbid (e.g., 1 hour). Then, sodium hydroxide is added to the resulting reactant until the pH reaches 8.0 to 9.0, followed by cooling to produce the melamine resin.

[0054] As the melamine-based resin, a commercially available product can be used.

[0055] Examples of commercially available melamine resins include Nikaresin (registered trademark) S-166, Nikaresin (registered trademark) S-176, Nikaresin (registered trademark) S-260, and Nikaresin (registered trademark) S-305 manufactured by NIPPON CARBIDE INDUSTRIES CO., INC.

[0056] The resin composition of the present disclosure may contain only one type of melamine-based resin, or may contain two or more types.

[0057] The content of the melamine-based resin in the resin composition of the present disclosure is not particularly limited. For example, the content is preferably in the range of 10 to 90 parts by mass, more preferably in the range of 15 to 85 parts by mass, further preferably in the range of 20 to 80 parts by mass, and particularly preferably in the range of 25 to 75 parts by mass, relative to 100 parts by mass of the total solid content of the resin composition.

[0058] In the present disclosure, the “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 obtained by removing the solvent from the resin composition when the resin composition contains a solvent.

[0059] Filling material

[0060] The resin composition of the present disclosure contains a filler material.

[0061] When the resin composition of the present disclosure contains a filler, the strength of the molded product of the resin composition is appropriately maintained, and thus the workability when removing the molded product of the resin composition from the molding die after cleaning can be improved.

[0062] The filler may be either an organic filler or an inorganic filler.

[0063] (Organic filler)

[0064] Examples of the organic filler include pulp, wood flour, and synthetic fibers.

[0065] Among them, pulp is particularly preferred as the organic filler.

[0066] Examples of pulp include wood pulp (conifer pulp, broadleaf pulp, etc.), non-wood pulp (straw, bamboo, bagasse, cotton, etc.), etc. These pulps may be either chemical pulp or mechanical pulp.

[0067] When the resin composition of the present disclosure contains pulp as an organic filler, the pulp is preferably used as pulp impregnated with a melamine-based resin.

[0068] In pulp impregnated with melamine resin, at least a portion of the melamine resin penetrates into gaps between pulp fibers, or at least a portion of the melamine resin covers a portion or all of the pulp fiber surface.

[0069] The pulp impregnated with the melamine resin is obtained by immersing the pulp in an aqueous solution containing the melamine resin and then drying the pulp.

[0070] The size of the pulp is not particularly limited.

[0071] The size of the pulp is preferably in the range of 5 μm to 1000 μm, and more preferably in the range of 10 μm to 200 μm, for example, in terms of fiber length.

[0072] When the pulp size is within the above range, the strength of the resin composition molded article is more appropriately maintained, thereby further improving the workability when removing the resin composition molded article from the mold after cleaning. Furthermore, when the pulp size is within the above range, the flowability of the resin composition tends to be more optimal.

[0073] The fiber length of pulp is a value measured by a method in accordance with JIS P8226-2:2011 corresponding to ISO 16065-2:2007.

[0074] As the pulp, a commercially available product can be used.

[0075] Examples of commercially available pulp include "NSPP1" (trade name, softwood pulp) and "LDPT" (trade name, broadleaf pulp) manufactured by Nippon Paper Industries, Ltd.

[0076] 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.

[0077] When the resin composition of the present disclosure contains an organic filler as a filler, the content of the organic filler is not particularly limited, but is preferably in the range of 2 to 50 parts by mass, more preferably in the range of 2 to 30 parts by mass, and even more preferably in the range of 2 to 15 parts by mass, relative to 100 parts by mass of the total solid content of the resin composition.

[0078] 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 solids content of the resin composition, the strength of the molded product of the resin composition is more appropriately maintained, thereby further improving the workability when removing the molded product of the resin composition from the molding die after cleaning. In addition, 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 solids content of the resin composition, the flowability of the resin composition tends to be more appropriate.

[0079] (Inorganic filler)

[0080] The inorganic filler not only contributes to improving workability by maintaining appropriate strength of the molded product of the resin composition, but also contributes to improving cleaning performance by physically polishing the inner surface of the mold.

[0081] Examples of the inorganic filler include silicon carbide, silicon oxide (so-called silicon dioxide; the same shall apply hereinafter), titanium carbide, titanium oxide, boron carbide, boron oxide, aluminum oxide, magnesium oxide, calcium oxide, and calcium carbonate.

[0082] Among them, as the inorganic filler, from the viewpoint of being well mixed with the melamine-based resin when preparing the resin composition, it is preferably at least one selected from silicon carbide, silicon oxide, titanium carbide, titanium oxide, boron carbide, boron oxide, aluminum oxide, magnesium oxide and calcium oxide, and more preferably at least one selected from silicon oxide and titanium oxide.

[0083] The preferred material cannot be determined depending on the material and condition of the mold, but silicon oxide and titanium oxide are more preferred from the viewpoint of having appropriate hardness and suppressing wear and damage on the inner surface of the mold and the gate.

[0084] The hardness (so-called new Mohs hardness) of the inorganic fillers exemplified above 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.

[0085] As the inorganic filler, a commercially available product can be used.

[0086] Examples of commercially available inorganic fillers include "S440-4," "HS-202," "HS-204," and "UF-320" (all trade names, amorphous silica) from NIPPON STEEL Chemical & Material Co., Ltd. and Micron Corporation, and pure silica powder (trade name, crystalline silica) from Seto Ceramics Co., Ltd.

[0087] 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.

[0088] When the resin composition of the present disclosure contains an inorganic filler as a filler, the content of the inorganic filler is not particularly limited, but is preferably in the range of 5 to 30 parts by mass, and more preferably in the range of 10 to 25 parts by mass, relative to 100 parts by mass of the total solid content of the resin composition.

[0089] 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 strength of the molded product of the resin composition is more appropriately maintained, and the workability when removing the molded product of the resin composition from the molding die after cleaning can be further improved. In addition, 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.

[0090] <Acidic compounds>

[0091] The resin composition of the present disclosure contains an acidic compound.

[0092] In the resin composition of the present disclosure, the acidic compound can function as a curing catalyst for the melamine-based resin.

[0093] The acidic compound may be any compound that cures the melamine-based resin, and a typical example thereof is a Bronsted acid.

[0094] The acidic compound is a compound different from the specific imide compound. In other words, the acidic compound does not include a compound corresponding to the specific imide compound.

[0095] The acidic compound may be an organic acid or an inorganic acid.

[0096] Examples of the acidic compound as an organic acid include benzoic acid, tartaric acid, sulfamic acid, trimellitic acid, trimesic acid, acetic acid, behenic acid, palmitic acid, salicylic acid, o-toluic acid, phthalic acid, isophthalic acid, terephthalic acid, adipic acid, oxalic acid, 2-phenylsuccinic acid, 1,2-cyclohexanedicarboxylic acid, and sebacic acid.

[0097] Examples of the acidic compound as an inorganic acid include hydrochloric acid, sulfuric acid, phosphoric acid, and the like.

[0098] As the acidic compound, for example, from the viewpoint of suppressing the generation of burrs and cleaning performance, at least one selected from benzoic acid, tartaric acid, hydrochloric acid, sulfamic acid and trimellitic acid is preferred, and at least one selected from benzoic acid, tartaric acid, sulfamic acid and trimellitic acid is more preferred.

[0099] In addition, the acidic compound is preferably a compound having a carboxyl group.

[0100] If the acidic compound is a compound having a carboxyl group, there is a tendency to be less likely to generate burrs compared to the case where the acidic compound is a compound not having a carboxyl group. In addition, although the detailed mechanism is not yet clear, there is a tendency to further reduce the amount of formaldehyde that may be generated when the resin composition is molded.

[0101] Examples of the compound having a carboxyl group include benzoic acid, tartaric acid, trimellitic acid, trimesic acid, acetic acid, behenic acid, palmitic acid, salicylic acid, o-toluic acid, phthalic acid, isophthalic acid, terephthalic acid, adipic acid, oxalic acid, 2-phenylsuccinic acid, 1,2-cyclohexanedicarboxylic acid, and sebacic acid.

[0102] The resin composition of the present disclosure may contain only one type of acidic compound, or may contain two or more types.

[0103] The content of the acidic compound in the resin composition of the present disclosure is not particularly limited, but, for example, is preferably in the range of 0.01 to 5.0 parts by mass, more preferably in the range of 0.02 to 3.0 parts by mass, further preferably in the range of 0.03 to 2.0 parts by mass, and particularly preferably in the range of 0.03 to 1.0 part by mass, relative to 100 parts by mass of the total of the melamine-based resin and the filler (i.e., the organic filler and the inorganic filler).

[0104] 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 mass of the total of the melamine-based resin and the filler (i.e., the organic filler and the inorganic filler), burrs tend to be less likely to form. 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 mass 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 even better cleaning performance.

[0105] <Specified compounds>

[0106] The resin composition of the present disclosure contains at least one compound (specific compound) selected from an imide compound having a molecular weight of 500 or less (specific imide compound) and a urea compound having a molecular weight of 500 or less (specific urea compound).

[0107] In the resin composition of the present disclosure, the specific compound contributes to the adjustment of the curing speed.

[0108] As the specific compound, the resin composition of the present disclosure may contain only the specific imide compound, may contain only the specific urea compound, or may contain both the specific imide compound and the specific urea compound.

[0109] The molecular weight of the specific imide compound is 500 or less, preferably in the range of 50 to 500, more preferably in the range of 50 to 400, and even more preferably in the range of 50 to 300.

[0110] The reason why the molecular weight of the specific imide compound is 500 or less is to exclude so-called high molecular weight compounds. For example, the specific imide compound does not include imide resins.

[0111] The specific imide compound is not particularly limited, and examples thereof include phthalimide (molecular weight: 147), succinimide (molecular weight: 99), pyromellitimide (molecular weight: 216), 1,2,3,6-tetrahydrophthalimide (molecular weight: 151), 1,2-cyclohexanedicarboximide (molecular weight: 153), maleimide (molecular weight: 97), 4-aminophthalimide (molecular weight: 162), 3,3-dimethylglutarimide (molecular weight: 141), and N-(cyclohexylthio)phthalimide (molecular weight: 261).

[0112] 1,2,3,6-tetrahydrophthalimide exists in cis and trans isomers. However, the 1,2,3,6-tetrahydrophthalimide in the present disclosure may be either cis or trans or may be a mixture of these isomers.

[0113] The specific imide compound is preferably, for example, at least one selected from phthalimide, succinimide, pyromellitimide, 1,2,3,6-tetrahydrophthalimide, and 1,2-cyclohexanedicarboximide; more preferably, at least one selected from phthalimide, succinimide, 1,2,3,6-tetrahydrophthalimide, and 1,2-cyclohexanedicarboximide; further preferably, at least one selected from succinimide and 1,2,3,6-tetrahydrophthalimide; and particularly preferably, 1,2,3,6-tetrahydrophthalimide.

[0114] In addition, as a specific imide compound, from the viewpoint of further improving the suppression of the generation of burrs, at least one selected from phthalimide and succinimide is preferable.

[0115] Furthermore, the specific imide compound is preferably at least one selected from the group consisting of succinimide, 1,2,3,6-tetrahydrophthalimide, and 1,2-cyclohexanedicarboximide, for example, from the viewpoint of further improving cleaning performance.

[0116] When the resin composition of the present disclosure contains a specific imide compound as the specific compound, the resin composition may contain only one specific imide compound or may contain two or more specific imide compounds.

[0117] The molecular weight of the specific urea compound is 500 or less, preferably in the range of 50 to 500, and more preferably in the range of 50 to 200.

[0118] The reason why the molecular weight of the specific urea compound is 500 or less is to exclude high molecular weight compounds. For example, the specific urea compound does not include urea resins.

[0119] 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), and (4-ethoxyphenyl)urea (molecular weight: 180).

[0120] The specific urea compound is, for example, preferably at least one selected from urea, 1-methylurea, 1-ethylurea, 1,1-dimethylurea, and 1,3-dimethylurea, more preferably at least one selected from urea, 1,1-dimethylurea, and 1,3-dimethylurea, further preferably at least one selected from urea and 1,3-dimethylurea, and particularly preferably urea.

[0121] The specific urea compound is preferably at least one selected from 1,1-dimethylurea and 1,3-dimethylurea, for example, from the viewpoint of further improving cleaning performance. 1,3-dimethylurea is more preferred from the viewpoint of further improving suppression of burr generation.

[0122] When the resin composition of the present disclosure contains a specific urea compound as the specific compound, the resin composition may contain only one specific urea compound or may contain two or more specific urea compounds.

[0123] 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 not particularly limited, but, for example, is preferably in the range of 0.01 to 7.0 parts by mass, more preferably in the range of 0.1 to 5.0 parts by mass, further preferably in the range of 0.1 to 4.0 parts by mass, and particularly preferably in the range of 0.1 to 3.0 parts by mass, relative to 100 parts by mass of the total of the melamine-based resin and the filler (i.e., the organic filler and the inorganic filler).

[0124] 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) relative to 100 parts by mass of the total of the melamine-based resin and the filler (i.e., the organic filler and the inorganic filler) is within the above range, burrs tend to be less likely to form. 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) relative to 100 parts by mass of the total of the melamine-based resin and the filler (i.e., the organic filler and the inorganic filler) is within the above range, the resin composition tends to exhibit even better cleaning performance.

[0125] The resin composition of the present disclosure has a 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) in a range of 0.01 to 100.0, preferably 0.02 to 90.0, more preferably 0.5 to 80.0, further preferably 1.5 to 70.0, and particularly preferably 3.0 to 60.0.

[0126] When the ratio of the specific compound content to the acidic compound content of the resin composition of the present disclosure is within the above range, burrs tend to be less likely to form. Furthermore, when the ratio of the specific compound content to the acidic compound content of the resin composition of the present disclosure is within the above range, excellent cleaning performance tends to be exhibited.

[0127] In the resin composition of the present disclosure, the total content of the acidic compound, the specific imide compound, and the specific urea compound is preferably in the range of 0.1 to 12.0 parts by mass, more preferably in the range of 0.2 to 7.0 parts by mass, further preferably in the range of 0.3 to 6.0 parts by mass, and particularly preferably in the range of 0.4 to 5.0 parts by mass, relative to 100 parts by mass of the total of the melamine-based resin and the filler (i.e., the organic filler and the inorganic filler).

[0128] When the total content of the acidic compound, specific imide compound, and specific urea compound in the resin composition of the present disclosure is within the above-mentioned range relative to 100 parts by mass of the total of the melamine-based resin and filler (i.e., the organic filler and the inorganic filler), burrs tend to be less likely to form. Furthermore, when the total content of the acidic compound, specific imide compound, and specific urea compound in the resin composition of the present disclosure is within the above-mentioned range relative to 100 parts by mass of the total of the melamine-based resin and filler (i.e., the organic filler and the inorganic filler), excellent cleaning performance tends to be exhibited.

[0129] <Metallic soap>

[0130] The resin composition of the present disclosure preferably contains a metal soap.

[0131] If the resin composition of the present disclosure contains a metal soap, the fluidity of the resin composition is improved when cleaning the mold, and the melamine-based resin is more easily activated against stains that may be present on the inner surface of the mold, thereby enabling the resin composition to exhibit even better cleaning performance. Furthermore, if the resin composition of the present disclosure contains a metal soap, the resin composition's affinity for stains that may be present on the inner surface of the mold is enhanced, thereby enabling the resin composition to exhibit even better cleaning performance.

[0132] The metal soap is not particularly limited, and examples thereof include fatty acid metal salts composed of fatty acids and metals.

[0133] The fatty acid constituting the fatty acid metal salt may be either a saturated fatty acid or an unsaturated fatty acid, but is preferably a saturated fatty acid.

[0134] The number of carbon atoms in the fatty acid constituting the fatty acid metal salt is not particularly limited, but is preferably 12 to 20, and more preferably 14 to 18, for example.

[0135] Specific examples of fatty acids having 12 to 20 carbon atoms include lauric acid (IUPAC name: dodecanoic acid) having 12 carbon atoms, myristic acid (IUPAC name: tetradecanoic acid) having 14 carbon atoms, palmitic acid (IUPAC name: hexadecanoic acid) having 16 carbon atoms, stearic acid (IUPAC name: octadecanoic acid) having 18 carbon atoms, oleic acid (IUPAC name: cis-9-octadecanoic acid) having 18 carbon atoms, and arachidic acid (IUPAC name: eicosanoic acid) having 20 carbon atoms.

[0136] The metal constituting the fatty acid metal salt is not particularly limited, but is preferably at least one selected from zinc, aluminum, magnesium, and calcium, and more preferably zinc.

[0137] Specific examples of the fatty acid metal salt include zinc stearate, zinc myristate, zinc laurate, zinc palmitate, aluminum stearate, magnesium oleate, magnesium stearate, calcium stearate, sodium 12-hydroxystearate, potassium montanate, and lithium laurate.

[0138] When the resin composition of the present disclosure contains a metal soap, it may contain only one type of metal soap or two or more types of metal soap.

[0139] When the resin composition of the present disclosure contains a metal soap, the content of the metal soap is not particularly limited, but for example, is preferably in the range of 0.1 to 5.0 parts by mass, more preferably in the range of 0.1 to 4.0 parts by mass, and even more preferably in the range of 0.1 to 3.0 parts by mass, relative to 100 parts by mass of the total of the melamine-based resin and the filler (i.e., the organic filler and the inorganic filler).

[0140] 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 fluidity of the resin composition is further improved when cleaning the molding die, and the melamine resin is more likely to act on stains that may be present on the inner surface of the molding die, so the resin composition can exhibit more excellent cleaning performance. In addition, 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 has a better affinity for stains that may be present on the inner surface of the molding die, so the resin composition can exhibit more excellent cleaning performance.

[0141] If the resin composition containing the melamine-based resin contains an excessive amount of metal soap, the excess metal soap may remain in the molding die and contaminate the molding die.

[0142] When the content of the metal soap in the resin composition of the present disclosure is 5.0 parts by mass or less relative to 100 parts by mass of the total of the melamine-based resin and the filler (i.e., the organic filler and the inorganic filler), contamination of the molding die by the excess metal soap tends to be less likely to occur.

[0143] Lubricant

[0144] The resin composition of the present disclosure preferably contains a lubricant (but does not include a lubricant equivalent to the above-mentioned metal soap).

[0145] In the resin composition of the present disclosure, the lubricant can help improve the dispersibility of the components when preparing the resin composition and improve the fluidity of the resin composition when cleaning a molding die.

[0146] Examples of the lubricant include fatty acid amide-based lubricants.

[0147] Examples of fatty acid amide lubricants include saturated or unsaturated monoamide lubricants such as lauric acid amide, myristic acid amide, erucic acid amide, oleic acid amide, and stearic acid amide; and saturated or unsaturated bisamide lubricants such as methylene bisstearic acid amide, ethylene bisstearic acid amide, and ethylene bisoleic acid amide.

[0148] When the resin composition of the present disclosure contains a lubricant, it may contain only one type of lubricant or two or more types of lubricants.

[0149] When the resin composition of the present disclosure contains a lubricant, the content of the lubricant is not particularly limited, but is preferably in the range of 0.1 to 0.6 parts by mass, and more preferably in the range of 0.2 to 0.5 parts by mass, relative to 100 parts by mass of the total of the melamine-based resin and the filler (i.e., the organic filler and the inorganic filler).

[0150] <Other ingredients>

[0151] The resin composition of the present disclosure may contain components other than the above components (so-called other components) as needed within a range that does not impair the effects of the present disclosure.

[0152] Examples of other components include various additives such as colorants (for example, dyes and pigments) and antioxidants.

[0153] 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 in which the effects of the present disclosure are exhibited.

[0154] [Method for preparing resin composition]

[0155] The preparation method of the resin composition disclosed herein is not particularly limited.

[0156] The resin composition of the present disclosure can be prepared by mixing, for example, a melamine-based resin, a filler, an acidic compound, a specific amount of a specific compound (i.e., at least one compound selected from a specific imide compound and a specific urea compound), and optionally, arbitrary components such as a metal soap and a lubricant.

[0157] The "specific amount" referred to herein means 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) is in the range of 0.01 to 100.0.

[0158] 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 tumble mixer.

[0159] 〔use〕

[0160] The resin composition of the present disclosure is suitable for removing stains from the inner surface of a molding die from a sealing molding material containing a thermosetting resin represented by epoxy resin, silicone resin, melamine resin, urea resin, and phenolic resin, for example.

[0161] The resin composition disclosed herein is used to clean the inner surface of a molding die by transfer molding and is particularly suitable as a so-called transfer-type mold cleaning resin composition.

[0162] [Mold cleaning method]

[0163] The resin composition of the present disclosure is usually processed into a sheet and used for cleaning the inner surface of a molding die.

[0164] Specifically, after placing the lead frame in the mold, a sheet of resin composition is inserted into the groove, the mold is tightened, and then flushed with a plunger. The resin composition in the groove flows through the runner and gate into the cavity. After the specified molding time, the mold is opened and the molded product, which has been integrated with the lead frame and contains contaminated resin composition, is removed, thereby cleaning the interior surface of the mold.

[0165] Example

[0166] The present disclosure is further described below with reference to examples, but the present disclosure is not limited to the following examples unless the scope of the present disclosure exceeds the scope of the present disclosure.

[0167] [Preparation of melamine-based resin]

[0168] [Production Example A: Melamine-formaldehyde resin containing pulp]

[0169] 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 resulting reaction mixture until the pH reached 8.0 to 9.0, followed by cooling to obtain an aqueous solution containing a melamine-formaldehyde resin. 248 parts by mass of conifer pulp (trade name: NSPP1, Nippon Paper Industries, Ltd.) was added to the resulting aqueous solution containing the melamine-formaldehyde resin as an organic filler, kneaded, and then dried under reduced pressure and powdered to obtain a pulp-containing melamine-formaldehyde resin (pulp content: 28% by mass).

[0170] [Preparation of resin composition]

[0171] [Example 1]

[0172] 30 parts by mass of the pulp-containing melamine-formaldehyde resin (21.6 parts by mass as melamine-formaldehyde resin) of Production Example A of the melamine-based resin, 50 parts by mass of a melamine-formaldehyde resin [trade name: Nikaresin (registered trademark) S-166, Nippon Carbon Industries Co., Inc.], 20 parts by mass of silicon oxide [trade name: pure silica powder, crystalline silica, Seto Ceramics Co., Ltd.] as an inorganic filler, 0.12 parts by mass of benzoic acid [Fujifilm Wako Pure Chemical Industries, Ltd.] as an acidic compound, 1.00 parts by mass of phthalimide [Tokyo Chemical Industry Co., Ltd.] as a specific imide compound, and 1.13 parts by mass of zinc stearate [trade name: ZINCSTEARATE GF200, NOF Corporation] as a metal soap were placed in a ball mill and pulverized. Next, the obtained pulverized product and 0.36 parts by mass of ethylene bisstearamide (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.

[0173] [Example 2 to Example 11]

[0174] In Example 1, except having changed the composition of the resin composition into the composition shown in Table 1, the same operation as in Example 1 was carried out to obtain each resin composition of Examples 2 to 11.

[0175] [Example 12 to Example 18]

[0176] In Example 1, except having changed the composition of the resin composition into the composition shown in Table 2, the same operation as in Example 1 was carried out to obtain each resin composition of Examples 12 to 18.

[0177] [Example 19 to Example 29]

[0178] In Example 1, except having changed the composition of the resin composition into the composition shown in Table 3, the same operation as in Example 1 was carried out to obtain resin compositions of Examples 19 to 29.

[0179] [Example 30 to Example 39]

[0180] In Example 1, except having changed the composition of the resin composition into the composition shown in Table 4, the same operation as in Example 1 was carried out to obtain resin compositions of Examples 30 to 39.

[0181] [Example 40 to Example 44]

[0182] In Example 1, except having changed the composition of the resin composition into the composition shown in Table 5, the same operation as in Example 1 was carried out to obtain resin compositions of Examples 40 to 44.

[0183] [Example 45 to Example 53]

[0184] In Example 1, except having changed the composition of the resin composition into the composition shown in Table 6, the same operation as in Example 1 was carried out to obtain resin compositions of Examples 45 to 53.

[0185] [Comparative Examples 1 to 7]

[0186] In Example 1, except having changed the composition of the resin composition into the composition shown in Table 7, the same operation as in Example 1 was carried out to obtain resin compositions of Comparative Examples 1 to 7.

[0187] Each resin composition obtained as described above was processed into a sheet having a diameter of 14 mm. The obtained sheet-shaped resin composition was used as an evaluation resin composition for evaluation.

[0188] [evaluate]

[0189] 1. Burr generation suppression

[0190] The burr generation suppressive property was evaluated by molding each resin composition under the condition of intentionally increasing the molding pressure of the mold.

[0191] 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: 4.9 mm × 3.9 mm, Dai-ichi Seiko Co., Ltd.) under the following conditions: mold temperature 175°C, hold time 60 seconds, molding time 180 seconds, stroke time 2 seconds, and molding pressure 10 torr (≈1.33 kPa).

[0192] After molding, 10 squares ( Figure 1AThe presence and extent of burrs were checked in the area A (enclosed by the dotted line). Based on the results, the burr generation suppression performance was evaluated according to the following evaluation criteria. The evaluation used the observation results for the area with the most burrs among the 14 observed areas A.

[0193] If the evaluation result is "A," "B," or "C," there is no practical problem. Note that the resin composition least likely to generate burrs is the resin composition with an evaluation result of "A."

[0194] The results are shown in Tables 1 to 7.

[0195] For reference, a photograph showing an example of evaluation result "A" is shown in FIG. Figure 1A In addition, a photograph showing an example of the evaluation result "D" is shown in Figure 1B It should be noted that in each of the drawings, components denoted by the same reference numerals represent the same components.

[0196] Can confirm: Figure 1A As shown in FIG. 1 , in the case of the evaluation result “A”, no burrs are generated in the region A where there are 10 squares 30 engraved between the package 20 adjacent to the flow channel 10. On the other hand, in the case of the evaluation result “D”, as shown in FIG. Figure 1B As shown, burrs 40 are generated in a region A where ten squares 30 are engraved between the packaging bodies 20 adjacent to the flow channel 10 , and the burrs 40 cover the squares 30 .

[0197] (Evaluation Criteria)

[0198] A: Among the 10 squares, 0 or 1 square is completely covered by burrs.

[0199] B: 2 or 3 of the 10 squares are completely covered by burrs.

[0200] C: 4 or 5 of the 10 squares are completely covered by burrs.

[0201] D: Among 10 squares, 6 to 10 are completely covered with burrs.

[0202] 2. Cleaning performance

[0203] 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: 28 mm × 28 mm, Dai-ichi Seiko Co., Ltd.], the QFP was shot-molded 400 times using a semiconductor epoxy resin sealing material [trade name: CEL-9240HF10, Hitachi Chemical Co., Ltd.] at a mold temperature of 175°C, a hold time of 0.5 seconds, a molding time of 90 seconds, a stroke time of 10 seconds, and a molding pressure of 35 torr (≈4.67 kPa), so that stains adhered to the inner surface of the molding mold.

[0204] Using a molding die with the stain attached, the molding time is set to 180 seconds. In addition, the molding conditions (specifically, mold temperature, holding time, molding time, stroke time and molding pressure conditions) of the above-mentioned semiconductor epoxy resin sealing material are repeated in the same manner as the resin compositions of the embodiments and comparative examples to clean the molding die. Then, the molding times (hereinafter also referred to as "shot times") required for the stain attached to the inner surface of the molding die are measured until it is possible to completely remove the stain, and the shot times are used as an index for evaluating the cleaning performance of the resin composition. Whether the stain can be completely removed is visually confirmed and judged.

[0205] The fewer the number of repetitive molding cycles (i.e., the number of injections) required to completely remove stains attached to the inner surface of the mold, the better the cleaning performance. If the number of injections is 3 or less, there are no practical problems. It should be noted that if the resin composition does not diffuse into every corner of the mold, i.e., the so-called "unfilled" condition, it is evaluated as "NG" and judged to have poor cleaning performance.

[0206] The results are shown in Tables 1 to 7.

[0207] 3. Liquidity

[0208] Fluidity is one of the indicators that indicate the fluidity of a resin composition, and can be determined by the value of the spiral flow length (flow length). In this evaluation, the spiral flow length (unit: cm) of the resin composition was measured by the method according to ASTM D-3123. Specifically, a transfer molding machine [Model: MF-O70, TECHNO MARUSHICHI ENGINEERING CO., LTD.] was used, and under the conditions of a mold temperature of 175°C, a mold clamping pressure of 17.5 MPa, and a transfer pressure of 1.96 MPa, the evaluation resin composition was injected into the flow path of the spiral flow measurement mold specified in ASTM D-3123, and the spiral flow length at this time was measured. Then, based on the measured spiral flow length value, the fluidity of the resin composition was evaluated according to the following evaluation criteria.

[0209] The larger the spiral flow length, the higher the fluidity of the resin composition. If the spiral flow length is 35 cm to 75 cm, there is no practical problem.

[0210] The results are shown in Tables 1 to 7.

[0211] 4. Free formaldehyde concentration

[0212] The free formaldehyde concentration was measured using the sodium sulfite method. Specifically, the free formaldehyde concentration was measured using the following method.

[0213] 3 drops of rhodamine solution were added dropwise to 50 mL of a 0.5 mol / L (liter; the same below) aqueous sodium sulfite solution to obtain a reddish-brown solution. It should be noted that the reddish-brown color is the color of rhodamine. Next, a 0.1 mol / L aqueous hydrochloric acid solution was added dropwise to the obtained reddish-brown solution using a burette to eliminate the reddish-brown color. Next, 2 g of the evaluation resin composition was added to the solution from which the reddish-brown color was eliminated and stirred to obtain a pink turbid solution. Next, a 0.1 mol / L aqueous hydrochloric acid solution was added dropwise to the obtained pink turbid solution using a burette, and the free formaldehyde concentration was calculated based on the following formula according to the amount of the hydrochloric acid solution added dropwise until the pink color of the solution disappears (the so-called titration amount).

[0214] The results are shown in Tables 1, 3, and 7.

[0215] Free formaldehyde concentration [unit: mass %] = (H × F × C × 30.03) / S

[0216] H [unit: ml]: titration of 0.1 mol / L hydrochloric acid aqueous solution

[0217] F: The potency of 0.1 mol / L hydrochloric acid aqueous solution

[0218] C [unit: mol / L]: concentration of hydrochloric acid aqueous solution

[0219] S [unit: g]: amount of the resin composition for evaluation

[0220] 30.03: Formula weight of formaldehyde

[0221]

[0222]

[0223]

[0224]

[0225] [Table 5]

[0226]

[0227]

[0228]

[0229] In Tables 1 to 7, “-” in the composition column indicates that the component corresponding to that column is not contained.

[0230] In Tables 1 to 7, the numerical values ​​in the acidic compound, specific imide compound, specific urea compound, comparative compound, metal soap, and lubricant composition columns represent the amounts (parts by mass) relative to 100 parts by mass of the total of the melamine resin and filler (organic filler + inorganic filler).

[0231] In Table 7, the “-” in the “Total content of the acidic compound, the specific imide compound, and the specific urea compound relative to 100 parts by mass of the total of the melamine-based resin and the filler (organic filler + inorganic filler)” column and the “Ratio of the total mass of the specific imide compound and the specific urea compound to the mass of the acidic compound” column indicates that the acidic compound, which is an essential component of the resin composition of the present disclosure, is not included and therefore no calculated value is given.

[0232] In Tables 1 to 7, “-” written in the evaluation column means that the evaluation corresponding to the column was not performed.

[0233] The details of the components described in Tables 1 to 7 are as follows.

[0234] <Melamine resin + organic filler>

[0235] “Melamine-formaldehyde resin containing pulp” [Production Example A]

[0236] <Melamine resin>

[0237] Melamine-formaldehyde resin (S-166) [Trade name: Nikaresin (registered trademark) S-166, NIPPONCARBIDE INDUSTRIES CO., INC.]

[0238] Melamine-formaldehyde resin (S-176) [Trade name: Nikaresin (registered trademark) S-176, NIPPONCARBIDE INDUSTRIES CO., INC.]

[0239] <Inorganic fillers>

[0240] "Silicon oxide" [Trade name: pure silica powder, crystalline silica, Seto Ceramics Co., Ltd.]

[0241] <Acidic compounds>

[0242] Benzoic acid (Fujifilm Wako Pure Chemical Industries, Ltd., monocarboxylic acid)

[0243] "Tartaric acid" [Fujifilm and Wako Pure Chemical Industries, Ltd., dicarboxylic acid]

[0244] "Hydrochloric acid"〔Fujifilm Wako Pure Chemical Industries, Ltd.〕

[0245] "Sulfamate" [Fujifilm and Wako Pure Chemical Industries, Ltd.]

[0246] "Trimellitic acid" [Fujifilm and Wako Pure Chemical Industries, Ltd., tricarboxylic acid]

[0247] <Specific imide compound>

[0248] Phthalimide [Molecular weight: 147, Tokyo Chemical Industry Co., Ltd.]

[0249] "Succinimide" [Molecular weight: 99, Tokyo Chemical Industry Co., Ltd.]

[0250] "cis-1,2,3,6-tetrahydrophthalimide" [Molecular weight: 151, cis form, Tokyo Chemical Industry Co., Ltd.]

[0251] 1,2,3,6-Tetrahydrophthalimide [Molecular weight: 151, mixture of cis- and trans-isomers, Fujifilm Wako Pure Chemical Industries, Ltd.]

[0252] "1,2-Cyclohexanedicarboximide" [Molecular weight: 153, Tokyo Chemical Industry Co., Ltd.]

[0253] <Specific urea compounds>

[0254] "Urea" [Molecular weight: 60, Tokyo Chemical Industry Co., Ltd.]

[0255] "1-Methylurea" [Molecular weight: 74, Tokyo Chemical Industry Co., Ltd.]

[0256] "1-Ethylurea" [Molecular weight: 88, Tokyo Chemical Industry Co., Ltd.]

[0257] 1,1-Dimethylurea [Molecular weight: 88, Tokyo Chemical Industry Co., Ltd.]

[0258] "1,3-Dimethylurea" [Molecular weight: 88, Tokyo Chemical Industry Co., Ltd.]

[0259] Comparative Compounds

[0260] Urea resin (trade name: LEADLITE) [weight average molecular weight: 800, Taiwa Co., Ltd.]

[0261] "Monoethanolamine" [Fujifilm and Wako Pure Chemical Industries, Ltd.]

[0262] <Metallic soap>

[0263] "Zinc stearate" [Trade name: ZINC STEARATE GF200, NOF Corporation]

[0264] Zinc myristate [Trade name: POWDER BASE M, NOF Corporation]

[0265] Lubricant

[0266] Ethylene bisstearamide [Trade name: ALFLOW (registered trademark) H50T, NOF Corporation]

[0267] As shown in Tables 1 to 6, the resin compositions of Examples 1 to 53 were less prone to burring and exhibited excellent cleaning performance. Furthermore, the resin compositions of Examples 1 to 53 exhibited adequate fluidity. Furthermore, a comparison with the resin composition of Comparative Example 1 revealed that the resin compositions of Examples 1 to 5 and Examples 19 to 23 exhibited reduced formaldehyde generation.

[0268] On the other hand, as shown in Table 7, the resin compositions of Comparative Examples 1 to 4, which did not contain the specific imide compound and the specific urea compound, were prone to burring and had poor cleaning performance compared to the resin compositions of the Examples. Furthermore, compared to the resin compositions of the Examples, the resin composition of Comparative Example 5, in which the ratio of the total mass of the specific imide compound and the specific urea compound to the mass of the acidic compound was less than 0.01, and the resin compositions of Comparative Examples 6 and 7, in which the ratio exceeded 100.0, were prone to burring and had poor cleaning performance.

[0269] The resin composition of Comparative Example 3, which contained a urea resin instead of a specific urea compound, exhibited significant burrs and significantly inferior cleaning performance compared to the resin compositions of Examples containing a specific urea compound. This is presumably because the inclusion of a urea resin in the resin composition preferentially causes a condensation reaction between the urea resin and the melamine-based resin, leading to the urea resin being incorporated into the crosslinked structure, resulting in a resin composition with an appropriate viscosity unlike the resin composition containing a specific urea compound.

[0270] The disclosure of Japanese Patent Application No. 2020-006344 filed on January 17, 2020 is incorporated herein by reference in its entirety.

[0271] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference, and each document, patent application, and technical standard is incorporated by reference specifically to the same extent as if it were individually described.

Claims

1. A resin composition for mold cleaning, comprising: Melamine resin, Filling materials, Acidic compounds, and at least one compound selected from the group consisting of an imide compound having a molecular weight of 500 or less and a urea compound having 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 is in the range of 0.01 to 100.

0.

2. The mold cleaning resin composition according to claim 1, wherein The total content of the acidic compound, the imide compound, and the urea compound is in the range of 0.1 to 12.0 parts by mass relative to 100 parts by mass of the total of the melamine-based resin and the filler.

3. The mold cleaning resin composition according to claim 1 or 2, wherein The imide compound is at least one selected from phthalimide, succinimide, pyromellitimide, 1,2,3,6-tetrahydrophthalimide and 1,2-cyclohexanedicarboximide, and the urea compound is at least one selected from urea, 1-methylurea, 1-ethylurea, 1,1-dimethylurea and 1,3-dimethylurea.

4. The mold cleaning resin composition according to claim 1 or 2, wherein The acidic compound is a compound having a carboxyl group.

5. The mold cleaning resin composition according to claim 1 or 2, wherein The acidic compound is at least one selected from benzoic acid, tartaric acid, hydrochloric acid, sulfamic acid and trimellitic acid.

6. The mold cleaning resin composition according to claim 1 or 2, wherein The content of the acidic compound is in the range of 0.01 to 5.0 parts by mass relative to 100 parts by mass of the total of the melamine-based resin and the filler. The mold cleaning resin composition according to claim 1 or 2, comprising a metal soap. The mold cleaning resin composition according to claim 1 or 2, further comprising a lubricant.

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