JP7265495B2 - Mold cleaning resin composition - Google Patents

Description

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

2. Description of the Related Art In recent years, as mobile terminals typified by smart phones have become highly functional, semiconductors have been miniaturized. In addition, the spread of work robots and the rapid electrification of automobiles due to labor shortages and cost reductions are rapidly increasing the types and amounts of semiconductors used, and the frequency of semiconductor replacement is also increasing. Under these circumstances, molds that can cope with multi-cavity design of packages, complicated semiconductor patterns, etc. are becoming popular.

In recent years, with the demand for more efficient molding of semiconductor encapsulating resins, there has been a growing demand for more efficient cleaning of resin compositions for cleaning molding dies (so-called mold cleaning resin compositions). It has been demanded. In order to efficiently clean the mold, it is desirable that the resin composition for mold cleaning exhibits high fluidity so as to quickly spread throughout the interior of the mold. Several reports have been made on methods for controlling the fluidity of the resin composition for mold cleaning.

For example, in Patent Document 1, by using a blocked carboxylic acid as a curing agent for a melamine-based resin, it exhibits the necessary fluidity (so-called appropriate fluidity) for spreading to every corner of the mold even at low temperatures. A resin composition for cleaning molds has been realized.
Further, in Patent Literature 2, by using a plurality of curing catalysts, a resin composition for cleaning molds having well-balanced curing and fluidity is realized.
In addition, in Patent Document 3, by using an inorganic filler having a specific range of average particle size, standard deviation of particle size, average aspect ratio of particle size, and standard deviation of aspect ratio of particle size, the inside of the mold is A resin composition for mold cleaning that exhibits good fluidity and can be spread to every corner of the gap is realized.

JP 2019-126966 A JP 2017-177623 A WO2013/011876

With the advance of multi-cavity design, miniaturization, and complication of patterns in molding dies, it is not enough to control the fluidity of the mold cleaning resin composition to make the molding dies more compact. It has become difficult to spread to every corner of the interior. Therefore, measures have been taken to increase the speed, pressure, etc., of the plunger that pushes the mold cleaning resin composition into the mold. However, according to this countermeasure, when cleaning the molding die, the resin composition for cleaning the mold enters the gaps of the mating surfaces, the rubbing surfaces, etc. of the molding die, and burrs are likely to occur. The occurrence of burrs causes problems such as a decrease in workability, contamination of molded products, uneven quality of molded products, and the like, when molding a semiconductor encapsulating resin.
For this reason, resin compositions for cleaning molds are required to have excellent cleaning performance as well as the property of being resistant to the formation of burrs.

Regarding the above point, Patent Documents 1 to 3 do not pay attention to the problem of burr generation in the resin composition for cleaning molds.

The problem to be solved by the present invention is to provide a resin composition for cleaning molds that hardly generates burrs and has excellent cleaning performance.

Specific means for solving the problems include the following aspects.
<1> 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 and a urea compound having a molecular weight of 500 or less, The acidic compound is a compound different from the imide compound, and 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. Resin composition for mold cleaning.
<2> The total content of the acidic compound, the imide compound, and the urea compound is 0.1 parts by mass or more and 12.0 parts by mass or less with respect to a total of 100 parts by mass of the melamine resin and the filler. The resin composition for mold cleaning according to <1>, which is in the range of
<3> The imide compound is at least one selected from the group consisting of phthalimide, succinimide, pyromellitic imide, 1,2,3,6-tetrahydrophthalimide, and 1,2-cyclohexanedicarboximide. 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 <1> or <2>, the resin composition for cleaning molds.
<4> The resin composition for cleaning molds according to any one of <1> to <3>, wherein the acidic compound is a compound having a carboxy group.
<5> The mold according to 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. Cleaning resin composition.

ADVANTAGE OF THE INVENTION According to this invention, the resin composition for mold cleaning which is hard to produce a burr and is excellent in the cleaning performance is provided.

It is a photograph which shows an example of evaluation result "A" of the generation|occurrence|production suppression property of a burr in an Example. It is a photograph which shows an example of evaluation result "D" of the generation|occurrence|production suppression property of a burr in an Example.

Specific embodiments of the present invention will be described in detail below. However, the present invention is by no means limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the purpose of the present invention.

In this specification, the numerical range indicated using "to" means a range including the numerical values before and after "to" as the minimum and maximum values, respectively.
In the numerical ranges described stepwise in this specification, the upper limit or lower limit described in a certain numerical range may be replaced with the upper limit or lower limit of the numerical range described in other steps. . Moreover, in the numerical ranges described in this specification, the upper limit value or lower limit value described in a certain numerical range may be replaced with the values shown in the examples.
In the present specification, a combination of two or more preferred aspects is a more preferred aspect.
In the present specification, the amount of each component means the total amount of the multiple types of substances unless otherwise specified when there are multiple types of substances corresponding to each component.

As used herein, the term "internal surface of the mold" means a region that contacts the molded article molded by the mold.

[Resin composition for mold cleaning]
The resin composition for mold cleaning of the present invention (hereinafter also simply referred to as "resin composition") comprises a melamine resin, a filler, an acidic compound, and an imide compound having a molecular weight of 500 or less (hereinafter referred to as " and at least one compound selected from the group consisting of a urea compound having a molecular weight of 500 or less (hereinafter also referred to as a "specific urea compound"), and the acidic compound is a specific It is a compound different from the imide compound, and the ratio of the total content mass of the specific imide compound and the specific urea compound to the content mass of the acidic compound is in the range of 0.01 or more and 100.0 or less.
Hereinafter, in this specification, the specific imide compound and the specific urea compound may be collectively referred to as "specific compound".

A curing reaction in a mold cleaning resin composition containing a melamine-based resin and a curing catalyst proceeds as follows. First, the melamine resin contained in the mold cleaning resin composition is melted by heating. Next, a curing catalyst acts on the melted melamine resin to cure the mold cleaning resin composition. Generally, the curing speed of the resin composition for mold cleaning is greatly affected by the content of the curing catalyst. When the amount of the curing catalyst contained in the resin composition for cleaning molds is large, the resin composition for cleaning molds has a high curing speed and a low fluidity. As molds become more compact, more compact, and have more complex patterns, it becomes difficult to control the fluidity of the mold cleaning resin composition simply by adjusting the content of the curing catalyst. ing. In addition, it is difficult to spread the mold cleaning resin composition to every corner of the mold only by controlling the fluidity of the mold cleaning resin composition. Therefore, in recent years, measures have been taken to increase the speed, pressure, etc. of the plunger that pushes the mold cleaning resin composition into the mold. However, according to this countermeasure, when cleaning the molding die, the resin composition for cleaning the mold enters the gaps of the mating surfaces, the rubbing surfaces, etc. of the molding die, and burrs are likely to occur. The occurrence of burrs causes problems such as a decrease in workability, contamination of molded products, uneven quality of molded products, and the like, when molding a semiconductor encapsulating resin.

In contrast, the resin composition for mold cleaning of the present invention 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, so that the mold can be cleaned. It is difficult to generate burrs and has excellent cleaning performance.
The reason why the resin composition for mold cleaning of the present invention can exhibit such effects is not clear, but the present inventors speculate as follows. However, the following assumptions are not intended to restrictively interpret the resin composition for mold cleaning of the present invention, but are explained as an example.

In the mold cleaning resin composition of the present invention, it is believed that the acidic compound has the effect of increasing the curing speed, while the specific imide compound and the specific urea compound have the effect of retarding the curing speed. Therefore, when the mold cleaning resin composition of the present invention is heated, in the curing stage, a cured product with a relatively large molecular weight (in other words, a long molecular chain) and a cured product with a relatively small molecular weight (in other words, a molecular chain) It is thought that a cured product with a short time will coexist. Cured products having different molecular weights are moderately entangled with each other, and excessive viscosity reduction is suppressed, so that the fluidity of the mold cleaning resin composition becomes moderate, and as a result, the mold cleaning resin composition is molded. It is presumed that the penetration into the gap of the mold is suppressed and the generation of burrs is suppressed. In addition, the fluidity of the mold-cleaning resin composition becomes moderate, and the mold-cleaning resin composition spreads throughout the interior of the mold, so that the excellent cleaning performance of the melamine-based resin is effectively exhibited. It is thought that
Although the detailed mechanism is unknown, the mold cleaning resin composition of the present invention can have the effect of reducing the amount of formaldehyde that can be generated during molding.

<Melamine resin>
The resin composition of the present invention contains a melamine resin.
In the resin composition of the present invention, the melamine resin contributes to cleaning performance.
A melamine resin has a highly polar methylol group. In a resin composition containing a melamine-based resin, the highly polar methylol groups of the melamine-based resin cause stains (hereinafter also referred to as "contaminants") originating from sealing molding materials containing thermosetting resins such as epoxy resins. It is considered that the cleaning performance effect is achieved by acting on the

As used herein, "melamine resin" means melamine resin, melamine-phenol cocondensate, and melamine-urea cocondensate.

Melamine resins are condensates of triazine compounds and aldehyde compounds.
Triazine compounds include melamine, benzoguanamine, acetoguanamine, and the like.
Aldehyde compounds include formaldehyde, paraformaldehyde, acetaldehyde, and the like.
In the melamine resin, the molar ratio of repeating units derived from the triazine compound to repeating units derived from the aldehyde compound (repeating units derived from the triazine compound/repeating units derived from the aldehyde compound) is 1/1.2 to 1/4. is preferred.

A melamine-phenol cocondensate is a cocondensate of a triazine compound, a phenolic compound and an aldehyde compound.
Phenol compounds include phenol, cresol, xylenol, ethylphenol, butylphenol and the like.
In the melamine-phenol cocondensate, the molar ratio of repeating units derived from the triazine compound to repeating units derived from the phenol compound (repeating units derived from the triazine compound/repeating units derived from the phenol compound) is 1/0.3 to 1/ 1 is preferred.
In the melamine-phenol cocondensate, the molar ratio of repeating units derived from the triazine compound to repeating units derived from the aldehyde compound (repeating units derived from the triazine compound/repeating units derived from the aldehyde compound) is 1/1 to 1/ 3 is preferred.

A melamine-urea cocondensate is a cocondensate of a triazine compound, a urea compound and an aldehyde compound.
Urea compounds include urea, thiourea, ethylene urea, and the like.

A melamine-based resin can be produced by a known method.
For example, melamine resin is prepared by stirring melamine crystals and formaldehyde under the conditions of 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. After that, the mixture is cooled and reacted at 60° C. for a period of time (for example, 1 hour) until the 3 mass % aqueous solution of the reactant becomes cloudy. Next, sodium hydroxide is added to the obtained reactant until the pH reaches 8.0 to 9.0, and the mixture is cooled to produce a melamine resin.

A commercially available product can be used as the melamine resin.
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) available from Nippon Carbide Industry Co., Ltd. and S-305.

The resin composition of the present invention may contain only one type of melamine resin, or may contain two or more types.

The content of the melamine resin in the resin composition of the present invention is not particularly limited. Preferably, it is in the range of 15 parts by mass or more and 85 parts by mass or less, more preferably in the range of 20 parts by mass or more and 80 parts by mass or less, and preferably in the range of 25 parts by mass or more and 75 parts by mass or less. Especially preferred.
As used herein, the term "total solid content of the resin composition" means the total mass of the resin composition when the resin composition does not contain a solvent (e.g., water; hereinafter the same). When the composition contains a solvent, it means the mass of the residue after removing the solvent from the resin composition.

<Filling material>
The resin composition of the present invention contains a filler.
When the resin composition of the present invention contains a filler, the strength of the molded product of the resin composition is properly maintained, so that the workability when removing the molded product of the resin composition from the mold after cleaning is improved. can.
The filler may be either an organic filler or an inorganic filler.

(organic filler)
Organic fillers include pulp, wood flour, synthetic fibers and the like.
Among these, pulp is particularly preferable as the organic filler.
Pulp includes wood pulp (softwood pulp, hardwood pulp, etc.), non-wood pulp (straw, bamboo, bagasse, cotton, etc.), and the like. These pulps may be chemical pulps or mechanical pulps.

When the resin composition of the present invention contains pulp as an organic filler, the pulp is preferably used as pulp impregnated with a melamine resin.
In pulp impregnated with a melamine resin, at least part of the melamine resin is in the interstices of the pulp fibers, or at least part of the melamine resin is part of the surface of the pulp fibers. Or it is in a state where it is entirely covered.
A pulp impregnated with a melamine resin is obtained by impregnating the pulp with an aqueous solution containing a melamine resin and then drying the pulp.

The size of pulp is not particularly limited.
The size of the pulp, for example, is preferably in the range of 5 μm or more and 1000 μm or less, more preferably in the range of 10 μm or more and 200 μm or less, in terms of fiber length.
When the size of the pulp is within the above range, the strength of the molded resin composition is more appropriately maintained, so that the workability when removing the molded resin composition from the mold after cleaning is improved. can improve. Moreover, when 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 pulp is a value measured by a method conforming to the provisions of JIS P8226-2 corresponding to ISO16065-2.

A commercially available product can be used as the pulp.
Examples of commercially available pulp include "NSPP1" (trade name, softwood pulp) and "LDPT" (trade name, hardwood pulp) available from Nippon Paper Industries Co., Ltd.

When the resin composition of the present invention contains an organic filler as a filler, it may contain only one type of organic filler, or may contain two or more types.

When the resin composition of the present invention contains an organic filler as a filler, the content of the organic filler is not particularly limited. It is preferably in the range of 50 parts by mass or less, 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.
When the content of the organic filler is within the above range with respect 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. Workability can be further improved when removing the molded product of the resin composition from the mold. Moreover, when the content of the organic filler is within the above range with respect 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 filler)
Inorganic fillers can contribute not only to improving workability by maintaining appropriate strength of moldings of the resin composition, but also to improving cleaning performance by physically polishing the inner surface of the molding die.
Examples of inorganic fillers include silicon carbide, silicon oxide (so-called silica; hereinafter the same), titanium carbide, titanium oxide, boron carbide, boron oxide, aluminum oxide, magnesium oxide, calcium oxide, and calcium carbonate.
Among these, as the inorganic filler, silicon carbide, silicon oxide, titanium carbide, titanium oxide, boron carbide, boron oxide, oxide At least one selected from the group consisting of aluminum, magnesium oxide, and calcium oxide is preferred, and at least one selected from the group consisting of silicon oxide and titanium oxide is more preferred.
Although it depends on the material and state of the mold, silicon oxide and titanium oxide have suitable hardness, and can suppress the occurrence of abrasion and damage to the inner surface and gate portion of the mold. more preferable in terms of

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

A commercial item can be used as an inorganic filler.
Examples of commercially available inorganic fillers include "S440-4", "HS-202", "HS-204", and "UF-320" (all trade names , amorphous silica), pure silica stone powder (trade name, crystalline silica) of Seto Ceramic Raw Materials Co., Ltd., and the like.

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

When the resin composition of the present invention contains an inorganic filler as a filler, the content of the inorganic filler is not particularly limited, but for example, 5 parts by mass or more with respect to 100 parts by mass of the total solid content of the resin composition It is preferably in the range of 30 parts by mass or less, and more preferably in the range of 10 parts by mass or more and 25 parts by mass or less.
When the content of the inorganic filler is within the above range with respect 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. Workability can be further improved when removing the molded product of the resin composition from the mold. Moreover, when the content of the inorganic filler is within the above range with respect 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 of the present invention contains an acidic compound.
In the resin composition of the present invention, the acidic compound can function as a curing catalyst for the melamine resin.
The acidic compound may be any substance that cures the melamine-based resin, and typically includes Bronsted acid.
Also, the acidic compound is a compound different from the imide compound described above.

The acidic compound may be an organic acid or an inorganic acid.
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, o-triylic acid, phthalic acid, isophthalic acid, terephthalic acid, and adipic acid. , oxalic acid, 2-phenylsuccinic acid, 1,2-cyclohexanedicarboxylic acid, sebacic acid and the like.
Acidic compounds that are inorganic acids include hydrochloric acid, sulfuric acid, phosphoric acid, and the like.

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

Moreover, it is preferable that it is a compound which has a carboxy group as an acidic compound.
When the acidic compound is a compound having a carboxy group, burrs tend to be less likely to occur than when the acidic compound is a compound having no carboxy group. In addition, although the detailed mechanism is unknown, there is a tendency that the amount of formaldehyde generated during molding of the resin composition is further reduced.

Examples of compounds having a carboxy group include, among the acidic compounds described above, benzoic acid, tartaric acid, trimellitic acid, trimesic acid, acetic acid, behenic acid, palmitic acid, salicylic acid, o-triylic acid, phthalic acid, isophthalic acid, and terephthalic acid. acid, adipic acid, oxalic acid, 2-phenylsuccinic acid, 1,2-cyclohexanedicarboxylic acid, sebacic acid and the like.

The resin composition of the present invention may contain only one type of acidic compound, or may contain two or more types.

The content of the acidic compound in the resin composition of the present invention is not particularly limited. It is preferably in the range of not less than 5.0 parts by mass, more preferably not less than 0.02 parts by mass and not more than 3.0 parts by mass, and not less than 0.03 parts by mass and not more than 2.0 parts by mass is more preferably in the range of
When the content of the acidic compound is within the above range with respect to a total of 100 parts by mass of the melamine resin and the filler (that is, the organic filler and the inorganic filler), burrs tend to be less likely to occur. They also tend to exhibit better cleaning performance.

<Specific compound>
The resin composition of the present invention comprises at least one compound selected from the group consisting of an imide compound having a molecular weight of 500 or less (that is, a specific imide compound) and a urea compound having a molecular weight of 500 or less (that is, a specific urea compound). (ie, specific compounds).
In the resin composition of the present invention, the specific compound contributes to adjusting the curing speed.

The resin composition of the present invention may contain only the specific imide compound as the specific compound, may contain only the specific urea compound, or may contain both the specific imide compound and the specific urea compound.

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.
That the specific imide compound has a molecular weight of 500 or less is intended to exclude so-called high-molecular compounds. For example, specific imide compounds do not include imide resins.

The specific imide compound is not particularly limited. molecular weight: 151), 1,2-cyclohexanedicarboximide (molecular weight: 153), maleimide (molecular weight: 97), 4-aminophthalimide (molecular weight: 162), 3,3-dimethylglutarimide (molecular weight: 141), N -(Cyclohexylthio)phthalimide (molecular weight: 261) and the like.
1,2,3,6-Tetrahydrophthalimide has cis and trans isomers. or a mixture of these isomers.

As the specific imide compound, for example, at least one selected from the group consisting of phthalimide, succinimide, pyromellitic imide, 1,2,3,6-tetrahydrophthalimide, and 1,2-cyclohexanedicarboximide is preferred. , phthalimide, succinimide, 1,2,3,6-tetrahydrophthalimide, and 1,2-cyclohexanedicarboximide are more preferably at least one selected from the group consisting of succinimide and 1,2,3, At least one selected from the group consisting of 6-tetrahydrophthalimide is more preferred, and 1,2,3,6-tetrahydrophthalimide is particularly preferred.
As the specific imide compound, for example, at least one selected from the group consisting of phthalimide and succinimide is preferable from the viewpoint of further improving the suppression of burr formation.
Further, the specific imide compound is, for example, selected from the group consisting of succinimide, 1,2,3,6-tetrahydrophthalimide, and 1,2-cyclohexanedicarboximide from the viewpoint of further improving cleaning performance. is preferably at least one.

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

The molecular weight of the specific urea compound is 500 or less, preferably in the range of 50 or more and 500 or less, and more preferably in the range of 50 or more and 200 or less.
The fact that the specific urea compound has a molecular weight of 500 or less is intended to exclude so-called high-molecular compounds. For example, specific urea compounds do not include urea resins.

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-dithiobiurea (molecular weight: 150), (4-ethoxyphenyl)urea (molecular weight: 180), and the like. .

The specific urea compound is, for example, preferably at least one selected from the group consisting of urea, 1-methylurea, 1-ethylurea, 1,1-dimethylurea, and 1,3-dimethylurea. At least one selected from the group consisting of 1-dimethylurea and 1,3-dimethylurea is more preferred, at least one selected from the group consisting of urea and 1,3-dimethylurea is more preferred, and urea is particularly preferred.
The specific urea compound is, for example, preferably at least one selected from the group consisting of 1,1-dimethylurea and 1,3-dimethylurea from the viewpoint of further improving cleaning performance. 1,3-Dimethylurea is more preferable from the viewpoint of further improving the suppression of generation.

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

The content of the specific compound (that is, the total content of the specific imide compound and the specific urea compound) in the resin composition of the present invention is not particularly limited, but for example, melamine resin and filler (that is, organic filler and inorganic It is preferably in the range of 0.01 parts by mass or more and 7.0 parts by mass or less, and preferably in the range of 0.1 parts by mass or more and 5.0 parts by mass or less with respect to the total 100 parts by mass of the filler). More preferably, it is in the range of 0.1 parts by mass or more and 3.0 parts by mass or less.
The content of the specific compound (that is, the total content of the specific imide compound and the specific urea compound) is within the above range with respect to a total of 100 parts by mass of the melamine resin and the filler (that is, the organic filler and the inorganic filler) , there is a tendency that burrs are less likely to occur. They also tend to exhibit better cleaning performance.

The resin composition of the present invention is a ratio of the content mass of the specific compound (that is, the total content mass of the specific imide compound and the specific urea compound) to the content mass of the acidic compound (content mass of the specific compound/content mass of the acidic compound). is in the range of 0.01 to 100.0, preferably in the range of 0.02 to 90.0, more preferably in the range of 0.5 to 80.0. It is more preferably in the range of 5 or more and 70.0 or less, and particularly preferably in the range of 3.0 or more and 60.0 or less.
When the content mass of the specific compound/the content mass of the acidic compound is within the above range, burrs tend to be less likely to occur. They also tend to exhibit superior cleaning performance.

In the resin composition of the present invention, the total content of the acidic compound, the specific imide compound, and the specific urea compound is based on a total of 100 parts by mass of the melamine resin and the filler (that is, the organic filler and the inorganic filler) , 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, and 0.3 to 7.0 parts by mass. It is more preferably in the range of 0 parts by mass or less, and particularly preferably in the range of 0.4 parts by mass or more and 5.0 parts by mass or less.
When the total content of the acidic compound, the specific imide compound, and the specific urea compound is within the above range with respect to a total of 100 parts by mass of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), Burrs tend to be less likely to occur. They also tend to exhibit superior cleaning performance.

<Metal soap>
The resin composition of the present invention preferably contains a metallic soap.
When the resin composition of the present invention contains a metal soap, the fluidity of the resin composition is improved when cleaning the molding die, and the melamine resin easily acts on stains that may exist on the inner surface of the molding die. Therefore, the resin composition can exhibit better cleaning performance. In addition, when the resin composition of the present invention contains a metal soap, the affinity between the resin composition and stains that may be present on the inner surface of the molding die increases, so the resin composition exhibits better cleaning performance. can.

Metal soaps are not particularly limited, 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 either saturated fatty acid or unsaturated fatty acid, preferably saturated fatty acid.
Although the number of carbon atoms of the fatty acid constituting the fatty acid metal salt is not particularly limited, it is preferably 12-20, more preferably 14-18, for example.
Specific examples of fatty acids having 12 to 20 carbon atoms include lauric acid having 12 carbon atoms (IUPAC name: dodecanoic acid), myristic acid having 14 carbon atoms (IUPAC name: tetradecanoic acid), and palmitic acid having 16 carbon atoms ( IUPAC name: hexadecanoic acid), C18 stearic acid (IUPAC name: octadecanoic acid), C18 oleic acid (IUPAC name: cis-9-octadecanoic acid), C20 arachidic acid (IUPAC name: eicosane acid) and the like.
Although the metal constituting the fatty acid metal salt is not particularly limited, it is preferably at least one selected from the group consisting of zinc, aluminum, magnesium, and calcium, and more preferably zinc.

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

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

When the resin composition of the present invention contains a metal soap, the content of the metal soap is not particularly limited. On the other hand, it is preferably in the range of 0.1 parts by mass or more and 5.0 parts by mass or less, more preferably in the range of 0.1 parts by mass or more and 4.0 parts by mass or less, and 0.1 parts by mass or more It is more preferably in the range of 3.0 parts by mass or less.
If the content of the metal soap is 0.1 parts by mass or more with respect to the total of 100 parts by mass of the melamine resin and the filler (i.e., the organic filler and the inorganic filler), cleaning the molding die The fluidity of the resin composition is further improved, and the melamine-based resin is more likely to act on dirt that may exist on the inner surface of the molding die, so the resin composition can exhibit better cleaning performance. Further, when the content of the metal soap is 0.1 parts by mass or more with respect to the total of 100 parts by mass of the melamine resin and the filler (that is, the organic filler and the inorganic filler), the resin composition and the molding Since the resin composition has a higher affinity for stains that may be present on the inner surface of the mold, the resin composition can exhibit better cleaning performance.

When a resin composition containing a melamine-based resin contains an excessive amount of metallic soap, the excess metallic soap may remain in the molding die and contaminate the molding die.
If the content of the metal soap is 5.0 parts by mass or less with respect to the total of 100 parts by mass of the melamine-based resin and the filler (i.e., the organic filler and the inorganic filler), molding caused by excess metal soap Mold contamination is less likely to occur.

<Lubricant>
The resin composition of the present invention preferably contains a lubricant (except for the metal soap described above).
In the resin composition of the present invention, the lubricant can contribute to improving the dispersibility of each component when preparing the resin composition and improving the fluidity of the resin composition when cleaning the molding die.

Lubricants include, for example, fatty acid amide-based lubricants.
Fatty acid amide-based lubricants include saturated or unsaturated monoamide-type lubricants such as lauric acid amide, myristic acid amide, erucic acid amide, oleic acid amide, stearic acid amide, methylene bis stearic acid amide, ethylene bis stearic acid amide, ethylene Saturated or unsaturated bisamide type lubricants such as bisoleic acid amide and the like are included.

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

When the resin composition of the present invention contains a lubricant, the content of the lubricant is not particularly limited. , preferably in the range of 0.1 to 0.6 parts by mass, more preferably in the range of 0.2 to 0.5 parts by mass.

<Other ingredients>
The resin composition of the present invention may contain components other than the components described above (so-called other components), if necessary, as long as the effects of the present invention are not impaired.
Other ingredients include colorants (eg, dyes and pigments), various additives such as antioxidants, and the like.

When the resin composition of the present invention contains other components, the content of the other components in the resin composition can be appropriately set within the range in which the effects of the present invention are exhibited.

[Method for preparing resin composition]
The method for preparing the resin composition of the present invention is not particularly limited.
The resin composition of the present invention comprises, for example, a melamine resin, a filler, an acidic compound, and a specific amount of a specific compound (that is, at least one compound selected from the group consisting of a specific imide compound and a specific urea compound). and, if necessary, optional components such as metallic soaps and lubricants.
The "specific amount" as used herein refers to the ratio of the total blended mass of the specific imide compound and the specific urea compound to the blended mass of the acidic compound (the total blended mass of the specific imide compound and the specific urea compound/the blended mass of the acidic compound ) means an amount in the range of 0.01 to 100.0.
The mixing method is not particularly limited, and examples thereof include mixing methods using known mixers such as kneaders, ribbon blenders, Henschel mixers, ball mills, roll kneaders, kneaders, and tumblers.

[Use]
The resin composition of the present invention removes stains from sealing molding materials containing thermosetting resins such as epoxy resins, silicone resins, melamine resins, urea resins, and phenolic resins. It is preferably used for removing from surfaces.
The resin composition of the present invention is particularly suitable as a so-called transfer-type mold cleaning resin composition for cleaning the inner surface of a mold by transfer molding.

[Mold cleaning method]
The resin composition of the present invention is usually processed into tablets and used for cleaning the inner surface of a molding die.
Specifically, after the lead frame is placed on the molding die, the tablet-shaped resin composition is inserted into the pot portion, and after the mold is clamped, it is pushed out with a plunger. At this time, the resin composition in the pot portion flows into the cavity through the runner portion and the gate portion. After a predetermined molding time has elapsed, the mold is opened and the inner surface of the mold is cleaned by removing the molded product integrated with the lead frame, that is, the molded product of the resin composition containing dirt.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples. The present invention is not limited to the following examples as long as the gist of the present invention is not exceeded.

[Preparation of melamine resin]
[Production Example A: Pulp-containing melamine-formaldehyde resin]
480 parts by mass of melamine and 522 parts by mass of formaldehyde (37% by mass aqueous solution) are stirred under conditions of 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. let me Next, an aqueous sodium hydroxide solution was added to the resulting reaction product until the pH reached 8.0 to 9.0, and the mixture was cooled to obtain an aqueous solution containing a melamine-formaldehyde resin. 248 parts by mass of softwood pulp (trade name: NSPP1, Nippon Paper Industries Co., Ltd.) is added as an organic filler to the aqueous solution containing the obtained melamine-formaldehyde resin, kneaded, dried under reduced pressure, and pulverized. , a pulp-containing melamine-formaldehyde resin (pulp content: 28% by mass) was obtained.

[Preparation of resin composition]
[Example 1]
As melamine-based resins, 30 parts by mass of the pulp-containing melamine-formaldehyde resin of Production Example A (21.6 parts by mass as melamine-formaldehyde resin) and melamine-formaldehyde resin [trade name: Nikaresin (registered trademark) S-166, Nippon Carbide Kogyo Co., Ltd.] 50 parts by mass, as an inorganic filler, silicon oxide [trade name: pure silica powder, crystalline silica, Seto Ceramics Raw Materials Co., Ltd.] 20 parts by mass, and as an acidic compound, benzoic acid [Fujifilm Wako Pure Chemical Industries, Ltd.] 0.12 parts by mass, phthalimide [Tokyo Chemical Industry Co., Ltd.] 1.00 parts by mass as a specific imide compound, and zinc stearate [trade name: zinc stearate GF200] as a metal soap. , NOF Corporation] 1.13 mass was charged into a ball mill and pulverized. Next, as a lubricant, 0.36 parts by mass of ethylene bis-stearic acid amide [trade name: Alflo (registered trademark) H50T, NOF Corporation] was added with a Nauta mixer and stirred to give the resin of Example 1. A composition was obtained.

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

[Examples 12 to 18]
In Example 1, except that the composition of the resin composition was changed to the composition shown in Table 2, the same operation as in Example 1 was performed to obtain resin compositions of Examples 12 to 18.

[Examples 19 to 29]
In Example 1, except that the composition of the resin composition was changed to the composition shown in Table 3, the same operation as in Example 1 was performed to obtain resin compositions of Examples 19 to 29.

[Examples 30 to 39]
In Example 1, except that the composition of the resin composition was changed to the composition shown in Table 4, the same operation as in Example 1 was performed to obtain resin compositions of Examples 30 to 39.

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

[Examples 45 to 53]
In Example 1, except that the composition of the resin composition was changed to the composition shown in Table 6, the same operation as in Example 1 was performed to obtain resin compositions of Examples 45 to 53.

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

Each resin composition obtained as described above was processed into tablets having a diameter of 14 mm. The resulting tablet-shaped resin composition was used for evaluation as a resin composition for evaluation.

[evaluation]
1. Burr Generation Suppression Performance The burr generation suppression performance was evaluated by molding each resin composition under conditions in which the molding pressure of the mold was intentionally increased.
Transfer type automatic molding machine [trade name: GP-PRO sf40, Daiichi Seiko Co., Ltd.] and SOIC (Small Outline Integrated Circuit) mold [package size: 4.9 mm × 3.9 mm, Daiichi Seiko ( Co., Ltd.] was used to mold a resin composition for evaluation under the conditions of 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 (≈ 1.33 kPa). bottom.
After molding, 10 squares (area A surrounded by dotted lines in FIG. 1A) carved between packages adjacent to a runner (a so-called resin composition path) were visually observed to determine whether or not burrs were generated. and the extent of Then, based on the confirmation results, the burr generation suppression property was evaluated according to the following evaluation criteria. For the evaluation, the observation result of the area where the most burrs occurred among the 14 observed areas A was adopted.
If the evaluation result is "A", "B" or "C", there is no practical problem. It should be noted that the resin composition that is least likely to generate burrs is the resin composition with the evaluation result of "A".
The results are shown in Tables 1-7.

For reference, a photograph showing an example of evaluation result "A" is shown in FIG. 1A, and a photograph showing an example of evaluation result "D" is shown in FIG. 1B. In addition, in each drawing, the component shown using the same code|symbol means that it is the same component.
As shown in FIG. 1A, in the case of the evaluation result “A”, no burr occurs in the region A where ten masses 30 are carved between the packages 20 adjacent to the runner 10 . On the other hand, in the case of the evaluation result "D", as shown in FIG. It can be seen that the burr 40 covers the mass 30 .

(Evaluation criteria)
A: Of the 10 squares, 0 or 1 square was completely covered with burrs.
B: 2 or 3 out of 10 squares were completely covered with burrs.
C: Of 10 squares, 4 or 5 squares were completely covered with burrs.
D: 6 to 10 out of 10 squares were completely covered with burrs.

2. Cleaning performance Transfer type automatic molding machine [trade name: GP-PRO sf40, Daiichi Seiko Co., Ltd.] and QFP (Quad Flat Package) mold [package size: 28mm x 28mm, Daiichi Seiko Co., Ltd.] , under the conditions of a mold temperature of 175 ° C., a holding 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), an epoxy resin sealing material for semiconductors [ 400 shots of QFP were molded using CEL-9240 HF10 (product name: Hitachi Kasei Co., Ltd.) to adhere dirt to the inner surface of the molding die.
The molding conditions for the epoxy resin encapsulant for semiconductors (specifically, mold temperature, holding time, molding time, Conditions of stroke time and molding pressure), each resin composition of Examples and Comparative Examples was repeatedly molded, and the molding die was cleaned. Then, the number of times of molding (hereinafter also referred to as "number of shots") required to completely remove dirt adhering to the inner surface of the molding die is measured, and this number of shots is used to measure the cleaning performance of the resin composition. It was used as an index for evaluation. Whether or not the dirt was completely removed was visually confirmed and judged.
The smaller the number of repeated moldings (the number of shots) required to completely remove dirt adhering to the inner surface of the molding die, the better the cleaning performance. If the number of shots is 3 or less, there is no practical problem. When the resin composition did not reach all corners of the inside of the mold, i.e., when a so-called unfilled state occurred, it was evaluated as "NG" and judged to have no cleaning performance.
The results are shown in Tables 1-7.

3. Fluidity Fluidity is an index showing the flowability of a resin composition, and can be determined by the value of spiral flow length (flow length). In this evaluation, the spiral flow length (unit: cm) of the resin composition was measured according to ASTM D-3123. Specifically, using a transfer molding machine [model: MF-O70, Techno Marushichi Co., Ltd.], a mold temperature of 175 ° C. , clamping pressure of 17.5 Mpa, and transfer pressure of 1.96 Mpa, the spiral flow length was measured when the evaluation resin composition was injected. Then, based on the measured spiral flow length, the fluidity of the resin composition was evaluated according to the following evaluation criteria.
A larger value of the spiral flow length indicates a higher fluidity of the resin composition. If the spiral flow length is 35 cm to 75 cm, there is no practical problem.
The results are shown in Tables 1-7.

4. Free Formaldehyde Concentration The sodium sulfite method was used to measure the free formaldehyde concentration. Specifically, it was measured by the following method.
Three drops of the rosolic acid solution were added dropwise to 50 mL of a 0.5 mol/L (liter; hereinafter the same) aqueous sodium sulfite solution to obtain a reddish brown solution. The reddish brown is a color derived from rosolic acid. Next, a 0.1 mol/L hydrochloric acid aqueous solution was added dropwise to the resulting reddish brown solution using a burette to erase the reddish brown color. Next, 2 g of the evaluation resin composition was added to the solution that had lost its reddish-brown color, and the mixture was stirred to obtain a pink cloudy solution. Next, a 0.1 mol/L hydrochloric acid aqueous solution was added dropwise to the resulting pink cloudy solution using a burette, and the amount of the hydrochloric acid aqueous solution dropped until the pink color of the solution disappeared (so-called titration amount), the concentration of free formaldehyde was determined based on the following formula.
The results are shown in Tables 1, 3 and 7.

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

In Tables 1 to 7, "-" described in the column of composition means that the component corresponding to that column is not included.
In Tables 1 to 7, the numerical values in the columns for the compositions of acidic compounds, specific imide compounds, specific urea compounds, comparative compounds, metallic soaps, and lubricants are melamine resins and fillers (organic fillers + inorganic fillers). The amount (parts by mass) is shown for a total of 100 parts by mass.
In Table 7, "total content of acidic compound, specific imide compound, and specific urea compound per 100 parts by mass of melamine resin and filler (organic filler + inorganic filler)" and "acidic compound "Ratio of the total content mass of the specific imide compound and the specific urea compound to the content mass of""-" is an essential component of the resin composition of the present invention Since it does not contain an acidic compound, the value is calculated. means it didn't.
In Tables 1 to 7, "-" written in the evaluation column means that the evaluation corresponding to that column was not performed.

The details of each component listed in Tables 1 to 7 are as shown below.
<Melamine resin + organic filler>
"Pulp-containing melamine-formaldehyde resin" [Production Example A]
<Melamine resin>
"Melamine-formaldehyde resin (S-166)" [trade name: Nikaresin (registered trademark) S-166, Nippon Carbide Industry Co., Ltd.]
"Melamine-formaldehyde resin (S-176)" [trade name: Nikaresin (registered trademark) S-176, Nippon Carbide Industry Co., Ltd.]
<Inorganic filler>
“Silicon oxide” [Product name: pure silica powder, crystalline silica, Seto Ceramic Raw Materials Co., Ltd.]

<Acidic compound>
"Benzoic acid" [Fujifilm Wako Pure Chemical Industries, Ltd., monocarboxylic acid]
“Tartaric acid” [Fujifilm Wako Pure Chemical Industries, Ltd., dicarboxylic acid]
“Hydrochloric acid” (FUJIFILM Wako Pure Chemical Industries, Ltd.)
“Sulfamic acid” [FUJIFILM Wako Pure Chemical Industries, Ltd.]
"Trimellitic acid" [FUJIFILM Wako Pure Chemical Industries, Ltd., tricarboxylic acid]

<Specific imide compound>
“Phthalimide” [molecular weight: 147, Tokyo Chemical Industry Co., Ltd.]
"Succinimide" [molecular weight: 99, Tokyo Chemical Industry Co., Ltd.]
"Pyromellitic imide" [molecular weight: 216, Tokyo Chemical Industry Co., Ltd.]
"cis-1,2,3,6-tetrahydrophthalimide" [molecular weight: 151, cis form, Tokyo Chemical Industry Co., Ltd.]
"1,2,3,6-tetrahydrophthalimide" [molecular weight: 151, mixture of cis and trans isomers, Fuji Film Wako Pure Chemical Industries, Ltd.]
"1,2-cyclohexanedicarboximide" [molecular weight: 153, Tokyo Chemical Industry Co., Ltd.]
<Specific urea compound>
"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-dimethyl urea" [molecular weight: 88, Tokyo Chemical Industry Co., Ltd.]
"1,3-dimethylurea" [molecular weight: 88, Tokyo Chemical Industry Co., Ltd.]
<Comparative compound>
"Urea resin (trade name: Readlight)" [weight average molecular weight: 800, Taiwa Co., Ltd.]
“Monoethanolamine” (Fujifilm Wako Pure Chemical Industries, Ltd.)

<Metal soap>
“Zinc stearate” [trade name: zinc stearate GF200, NOF Corporation]
“Zinc myristate” [Product name: Powder Base M, NOF Corporation]
<Lubricant>
“Ethylene bis stearamide” [trade name: Alflo (registered trademark) H50T, NOF Corporation]

As shown in Tables 1 to 6, the resin compositions of Examples 1 to 53 were less likely to generate burrs and had excellent cleaning performance. Moreover, the resin compositions of Examples 1 to 53 exhibited proper fluidity. Further, from comparison with the resin composition of Comparative Example 1, it was found that the resin compositions of Examples 1 to 5 and Examples 19 to 23 reduced the amount of formaldehyde generated.

On the other hand, as shown in Table 7, the resin compositions of Comparative Examples 1 to 4, which do not contain any of the specific imide compound and the specific urea compound, tend to generate burrs more easily than the resin compositions of Examples. , and inferior in cleaning performance. Further, the ratio of the total content mass of the specific imide compound and the specific urea compound to the content mass of the acidic compound is less than 0.01 for the resin composition of Comparative Example 5, and for Comparative Example 6 and Comparative Example 6, where the ratio exceeds 100.0 Compared with the resin compositions of Examples, the resin composition of Example 7 was likely to generate burrs and was inferior in cleaning performance.
According to the resin composition of Comparative Example 3 containing the urea resin instead of the specific urea compound, burrs were significantly generated, and the cleaning performance was significantly inferior to the resin composition of Examples containing the specific urea compound. was The reason is that when the resin composition contains a urea resin, the condensation reaction between the urea resin and the melamine resin occurs preferentially, and the urea resin is incorporated into the crosslinked structure, as in the case where the specific urea compound is contained. , it is presumed that the resin composition does not have an appropriate viscosity.

10 runner 20 package 30 mass 40 burr A region

Claims (5)

a melamine-based resin;
a filler;
an acidic compound;
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;
including
The acidic compound is a compound different from the imide compound,
A resin composition for cleaning a mold, wherein the ratio of the total content of the imide compound and the urea compound to the content of the acidic compound is in the range of 0.01 or more and 100.0 or less. The total content of the acidic compound, the imide compound, and the urea compound is in the range of 0.1 parts by mass or more and 12.0 parts by mass or less with respect to a total of 100 parts by mass of the melamine resin and the filler. The resin composition for mold cleaning according to claim 1. The imide compound is at least one selected from the group consisting of phthalimide, succinimide, pyromellitic imide, 1,2,3,6-tetrahydrophthalimide, and 1,2-cyclohexanedicarboximide, 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 described. 4. The resin composition for mold cleaning according to any one of claims 1 to 3, wherein the acidic compound is a compound having a carboxy group. The mold cleaning resin according to any one of claims 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. Composition.

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