JPWO2014119485A1 - Mold cleaning resin composition and mold cleaning method - Google Patents

Abstract

It contains a synthetic rubber, a compound selected from the group consisting of alkali metal salts and alkali metal hydroxides, silica, and a vulcanizing agent, and has a moisture content of 0.20% by mass or more and 3.50% by mass. % Or less of the mold cleaning resin composition.

Description

  The present invention relates to a mold cleaning resin composition and a mold cleaning method.

  In the case of molding an encapsulated molded product such as an integrated circuit element using an epoxy resin and a mold, if the molding is repeated for a long time, the inner surface of the molding mold becomes dirty. If the molding is continued as it is, there are many cases where the surface of the encapsulated molded product becomes dirty or the encapsulated molded product adheres to the mold and hinders the molding operation. Therefore, it is necessary to clean the mold regularly. As one of mold cleaning methods, a method of using a mold cleaning composition has been proposed.

The mold cleaning composition contains at least one selected from the group consisting of synthetic rubber and synthetic resin, at least one selected from the group consisting of alkali metal salts and alkali metal hydroxides, and water. A mold cleaning composition (see, for example, Japanese Patent Application Laid-Open No. 2011-21156), and at least one selected from the group consisting of synthetic rubber and synthetic resin, and an alkali metal salt and an alkali metal hydroxide. A mold cleaning composition containing at least one selected from the group and an organic solvent (for example, see JP 2011-20416 A) is proposed, and the cleaning performance is said to be improved. .
Moreover, when the mold contamination improving rubber composition contains rubber and an alkali metal phosphate, it is possible to prevent deterioration of the mold cleaning workability due to the addition of silica and contamination of the mold due to the vulcanizing agent. (See, for example, Japanese Patent Laid-Open No. 04-234444).

  However, a conventional mold cleaning resin composition containing an alkali metal salt or the like does not have sufficient storage stability and may not exhibit sufficient cleaning performance after a long period of time (for example, 6 months). there were.

  This invention is made | formed in view of the above situations, and an object of this invention is to provide the mold cleaning resin composition which is excellent in cleaning performance and storage stability, and the mold cleaning method using the same.

Specific means for solving the above problems are as follows.
<1> A synthetic rubber, a compound selected from the group consisting of an alkali metal salt and an alkali metal hydroxide, silica, and a vulcanizing agent, and a moisture content of 0.20% by mass or more 3 It is a resin composition for mold cleaning which is .5% by mass or less.

<2> The synthetic rubber is the mold cleaning resin composition according to <1>, including ethylene-propylene rubber and butadiene rubber.

<3> The mold cleaning resin composition according to <1> or <2>, wherein the silica content is 10 parts by mass or more and 60 parts by mass or less with respect to 100 parts by mass of the synthetic rubber. It is a thing.

<4> The <1> to <1>, wherein the mass ratio of the compound selected from the group consisting of the alkali metal salt and the alkali metal hydroxide to the water content is 0.1 or more and 5.0 or less. It is a resin composition for metal mold | die cleaning as described in any one of <3>.

<5> The resin composition for mold cleaning according to any one of <1> to <4>, wherein a mass ratio of the silica content to the water content is 3 or more and 30 or less. is there.

<6> The mold cleaning according to any one of <1> to <5>, wherein the silica has an equilibrium moisture content of 5% by mass to 9% by mass at a relative humidity of 60% and a temperature of 23 ° C. Resin composition.

<7> The content of the compound selected from the group consisting of the alkali metal salt and the alkali metal hydroxide is 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the synthetic rubber. It is the resin composition for metal mold | die cleaning as described in any one of said <1>-<6>.

<8> The content of the vulcanizing agent according to any one of <1> to <7>, wherein the content is 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the synthetic rubber. It is a resin composition for metal mold cleaning.

<9> A step of applying the mold cleaning resin composition according to any one of <1> to <8> to an inner surface of a molding die, and the mold cleaning resin composition And a step of heating the formed molding die.

In this specification, the numerical range indicated using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
In the present specification, the amount of each component in the composition is the total amount of the plurality of substances present in the composition unless there is a specific indication when there are a plurality of substances corresponding to each component in the composition. means.
In this specification, the term “process” is not limited to an independent process, and is included in this term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes. It is.
In the present specification, the “inner surface of the molding die” means a region in contact with a workpiece to be molded by the molding die. In the present specification, the “molding mold” may be simply referred to as “mold”.

  According to the present invention, it is possible to provide a mold cleaning resin composition excellent in cleaning performance and storage stability and a mold cleaning method using the same.

Hereinafter, the resin composition for mold cleaning and the mold cleaning method of the present invention will be described in detail.
<Resin composition for mold cleaning>
The resin composition for mold cleaning of the present invention includes a synthetic rubber, at least one selected from the group consisting of an alkali metal salt and an alkali metal hydroxide (hereinafter, also referred to as “specific cleaning agent”), silica, A vulcanizing agent, and the moisture content is 0.20% by mass or more and 3.50% by mass or less in the total mass of the mold cleaning resin composition.

  The resin composition for mold cleaning of the present invention contains silica and a specific cleaning agent that is at least one selected from the group consisting of alkali metal salts and alkali metal hydroxides, and the moisture content is specified. By being in this range, the specific cleaning agent acts effectively and can exhibit excellent cleaning performance. In addition, the mold cleaning resin composition of the present invention exhibits excellent cleaning performance even after a long period (for example, 6 months) has elapsed since the mold cleaning resin composition was produced. Can do. This can be considered as follows, for example.

  The conventional mold cleaning resin composition containing an alkali metal salt, etc., reduces the amount of water contained in the mold cleaning resin composition during storage of the mold cleaning resin composition, and the initial set physical properties (Mooney Viscosity, tensile strength, elongation, vulcanization characteristics, etc.) are considered to change. It is considered that the mold cleaning resin composition having a reduced amount of moisture during storage does not stretch properly during mold cleaning, and thus causes poor filling of the mold and poor mold cleaning. The inventors of the present invention include silica in the mold cleaning resin composition, and further the moisture content is 0.20% by mass or more and 3.50% by mass or less, so that the moisture over time is increased. It has been found that a decrease in the amount can be suppressed. Thereby, it is thought that the resin composition for metal mold | die cleaning excellent in storage stability can be provided.

  In general, a mold cleaning resin composition containing an alkali metal salt and moisture exhibits excellent mold cleaning ability. However, since the vulcanizing agent contained in the mold cleaning resin composition tends to deteriorate (decompose) due to the influence of heat, light, oxygen in the air, etc., the mold cleaning composition after long-term storage In some cases, the vulcanization performance may be reduced. When the vulcanization performance is deteriorated, the mold cleaning resin composition is not sufficiently cured at the time of mold cleaning, and therefore, contaminants cannot be sufficiently removed from the mold surface. The inventors of the present invention believe that in a resin composition for mold cleaning during long-term storage, deterioration of the vulcanizing agent is promoted by moisture contained in the mold cleaning composition. Instead of simply adding moisture to the mold cleaning resin composition as in the prior art, the moisture content is 0.20 mass% to 3.50 mass% after silica is contained instead. By configuring the resin composition for mold cleaning, it is considered that deterioration of the vulcanizing agent can be suppressed and excellent mold cleaning performance is maintained.

  The moisture in the mold cleaning resin composition may be water added during the production of the mold cleaning resin composition or may be moisture contained in the material constituting the mold cleaning resin composition. The moisture in the mold cleaning resin composition is preferably moisture contained in the material constituting the mold cleaning resin composition from the viewpoint of cleaning performance and storage stability.

The moisture content in the mold cleaning resin composition is 0.20% by mass or more and 3.50% by mass or less, and 0.50% by mass or more and 3.00% by mass from the viewpoint of mold cleaning properties and storage stability. % Is preferably 0.80% by mass or more and 2.90% by mass or less, more preferably 1.25% by mass or more and 2.80% by mass or less, and 1.40% by mass. % To 1.80% by mass is particularly preferable.
The moisture content in the mold cleaning resin composition can be measured by the Karl Fischer method. Specifically, it is measured by a moisture vaporization-coulometric titration method using a Karl Fischer moisture meter CA-100 and a moisture vaporizer VA-100 manufactured by Mitsubishi Chemical Corporation. In addition, the temperature for vaporization shall be 180 degreeC.

[Rubber component]
The resin composition for mold cleaning contains at least one synthetic rubber as a rubber component. The synthetic rubber is not particularly limited, and can be appropriately selected from commonly used synthetic rubbers. Synthetic rubber is so-called unvulcanized rubber, for example, ethylene-α-olefin rubber such as butadiene rubber (BR), nitrile rubber (NBR), ethylene-propylene rubber (EPR), styrene-butadiene rubber (SBR), Examples include polyisoprene rubber (IR), butyl rubber (IIR), silicone rubber (Q), and fluororubber (FKM). These may be used alone or in combination of two or more. These unvulcanized rubbers are vulcanized in the mold to become vulcanized rubber.

  The synthetic rubber is preferably at least one selected from the group consisting of ethylene-propylene rubber and butadiene rubber from the viewpoint of low contamination during mold cleaning and low odor during vulcanization. More preferably, it is a mixture of at least one ethylene-propylene rubber and at least one butadiene rubber.

  In this specification, the term “ethylene-propylene rubber” refers to both ordinary ethylene-propylene rubber (EPM) and ethylene-propylene-diene rubber (hereinafter sometimes abbreviated as “EPDM”). Meaning at least one selected from the group consisting of ethylene-propylene rubber and ethylene-propylene-diene rubber.

As the ethylene-propylene rubber, the copolymerization ratio of ethylene and an α-olefin containing at least propylene is preferably ethylene / α-olefin = 55/45 to 83/17 in molar ratio, 61/39 is more preferable, and 55/45 to 59/41 is even more preferable.
Examples of the α-olefin include propylene, isobutylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene and the like can be mentioned.

The ethylene / propylene ratio in the ethylene-propylene rubber can be calculated by measuring a ¹ H-NMR (proton nuclear magnetic resonance) spectrum at a resonance frequency of ¹ H: 500 MHz for the resin composition for mold cleaning. . In addition, after isolating ethylene-propylene rubber by a conventional method using HPLC (high performance liquid chromatograph) from the resin composition for mold cleaning, the ¹ H-NMR spectrum is measured in the same manner, so that it becomes clearer. The ethylene / propylene ratio can also be calculated.

  The ethylene-propylene-diene rubber means a terpolymer composed of ethylene, an α-olefin containing at least propylene, and a diene monomer which is a cyclic product or a non-cyclic product having two nonconjugated double bonds. Specifically, the terpolymer which consists of ethylene, alpha olefins, such as propylene, and a diene monomer is mentioned.

  Examples of the diene monomer include ethylidene norbornene, vinyl norbornene, dicyclopentadiene, 1,7-octadiene, 1,9-decadiene, 1,11-dodecadiene, 1,13-tetradecadiene, 1,15-hexadecadiene, 1,17-octadecadien, 1,19-icosadien, 3,6-dimethyl-1,7-octadiene, 4,5-dimethyl-1,7-octadiene, 5-methyl-1,8-nonadiene, dicyclo Pentadiene, 1,5-cyclooctadiene, 1,7-cyclododecadiene, 1,5,9-cyclododecatriene, 1,4-cycloheptadiene, 1,4-cyclohexadiene, norbornadiene, methylene norbornene, 2- Methylpentadiene-1,4,1,5-hexadiene, 1,6-heptadiene, Le - tetrahydroindene, 1,4-hexadiene, and the like.

  The content of the structural unit derived from the diene component in the ethylene-propylene-diene rubber is preferably 6.5% by mass to 9.5% by mass in the total mass of the ethylene-propylene-diene rubber, and 7.0% by mass. % To 9.0% by mass, more preferably 7.5% to 8.5% by mass. The iodine value of the ethylene-propylene-diene rubber is preferably 12-22, and more preferably 14-18.

The copolymerization ratio of each monomer in the terpolymer ethylene-propylene-diene rubber is as follows: ethylene is 30 mol% to 80 mol%, diene monomer is 0.1 mol% to 3 mol%, and the remainder is α-olefin. In some cases, ethylene is 30 mol% to 70 mol%, diene monomer is 0.1 mol% to 3 mol%, and the remainder is α-olefin. And as ethylene-propylene-diene rubber which is a terpolymer, it is preferable to use that whose Mooney viscosity ML1 _{+ 4} (100 degreeC) is 5-70.

The Mooney viscosity ML _{1 + 4} (100 ° C.) of the ethylene-propylene rubber is not particularly limited. From the viewpoint of cleaning performance, the Mooney viscosity ML _{1 + 4} (100 ° C.) of the ethylene-propylene rubber is preferably 5 to 40, and more preferably 5 to 30. The Mooney viscosity is measured according to JIS K 6300-1, “Unvulcanized rubber—physical properties—Part 1: Determination of viscosity and scorch time using Mooney viscometer”.

  From the viewpoint of cleaning performance, the content of the ethylene-propylene rubber is preferably 10% by mass to 50% by mass, and 20% by mass to 40% by mass in the total mass of the mold cleaning resin composition. It is more preferable. The mold cleaning resin composition may contain one kind of ethylene-propylene rubber, or may contain two or more kinds in combination.

The resin composition for mold cleaning preferably contains at least one butadiene rubber. The butadiene rubber is not particularly limited, and can be appropriately selected from commonly used butadiene rubbers. Among them, from the viewpoint of cleaning performance, butadiene rubber has a high cis structure in which the content of cis 1,4 bonds is 90% by mass or more, and has a Mooney viscosity ML _{1 + 4} (100 ° C.) of 20 to 60. A butadiene rubber having a high cis structure in which the content of the cis 1,4 bond is 90% by mass or more and a Mooney viscosity ML _{1 + 4} (100 ° C.) of 30 to 45 is more preferable. The said butadiene rubber may be used individually by 1 type, and may use 2 or more types together.

  Since the mold cleaning resin composition contains the ethylene-propylene rubber and the butadiene rubber, the hardness of the mold cleaning resin composition should be kept appropriate when removing dirt on the inner surface of the molding die. The resin composition for mold cleaning can be appropriately filled up to the details inside the mold. Moreover, since the strength of the mold cleaning resin composition can be maintained, the mold cleaning resin composition does not become brittle, and after removing the dirt, the mold cleaning resin composition is released from the mold. Work can be done easily.

The mass ratio (A) / (B) of the content of the ethylene-propylene rubber (A) contained in the resin composition for mold cleaning to the content of the butadiene rubber (B) is 20/80 to 90/10. It is preferable that the ratio is 30/70 to 80/20.
If the ethylene-propylene rubber is 90 parts by mass or less in 100 parts by mass of the total amount of ethylene-propylene rubber and butadiene rubber, good mold releasability is maintained and the cleaning operation time is not prolonged. If the butadiene rubber is 80 parts by mass or less, the mold releasability is good and the flexibility of the molded product after vulcanization is maintained. Therefore, if the blending ratio of the ethylene-propylene rubber and the butadiene rubber is within the above range, it is preferable from the viewpoint of cleaning performance.

The ethylene in the mold cleaning resin composition - the mass ratio to the content of the butadiene rubber content of propylene rubbers, for mold cleaning resin composition, ^{1 H-NMR} (the proton nuclear magnetic resonance) spectra ¹ The resonance frequency of H can be calculated by measuring at 500 MHz.

The synthetic rubber preferably has an elongation percentage of 40% to 800%, more preferably 100% to 300% after vulcanization and curing. If the elongation percentage after vulcanization and curing of the synthetic rubber is 40% or more, the moldability after vulcanization is maintained, which is preferable from the viewpoint of cleaning performance.
The synthetic rubber preferably has a tensile strength after vulcanization and curing of 3 MPa to 10 MPa, and more preferably 5 MPa to 8 MPa. If the tensile strength of the synthetic rubber after vulcanization and curing is 3 MPa or more, the occurrence of chipping is reduced, which is preferable from the viewpoint of cleaning performance.
The synthetic rubber has a rubber hardness (durometer hardness) after vulcanization and curing of preferably A60 to 95, and more preferably A70 to 90. If the rubber hardness after vulcanization and curing of the synthetic rubber is within this range, the occurrence frequency of chipping and voids is low, which is preferable from the viewpoint of cleaning performance.

  The resin composition for mold cleaning preferably contains ethylene-propylene rubber and butadiene rubber, which are synthetic rubbers, as rubber components, but other than these, other natural rubber, urethane rubber, nitrile rubber, silicone rubber, etc. A rubber component may be contained.

  As content of the said synthetic rubber, it is preferable that it is 20 mass%-90 mass% in a mass reference | standard in all the components contained in the resin composition for metal mold | die cleaning, It is 30 mass%-80 mass%. More preferably, it is more preferably 40% by mass to 70% by mass.

[Washing soap]
The resin composition for mold cleaning contains a specific cleaning agent that is at least one compound selected from the group consisting of alkali metal salts and alkali metal hydroxides.
Examples of the alkali metal in the alkali metal salt or alkali metal oxide that is the specific cleaning agent include lithium, sodium, potassium, rubidium, and cesium. Among these, the alkali metal is preferably at least one selected from the group consisting of lithium, sodium, and potassium from the viewpoint of cleaning performance, and is preferably at least one selected from the group consisting of sodium and potassium. More preferred.

  Alkali metal salts include silicate, borate, phosphate, metaphosphate, hypophosphate, phosphorous acid (phosphonic acid) salt, hypophosphorous acid (phosphinic acid) salt, pyrophosphate, Inorganic acid salts such as trimetaphosphate, tetrametaphosphate, pyrophosphorous acid, carbonate, sulfate, nitrate, hydrochloride; acrylate, adipate, ascorbate, aspartate, aminobenzoate , Alginate, benzoate, oleate, formate, citrate, glycolate, gluconate, glutamate, cinnamate, succinate, acetate, salicylate, oxalate, tartaric acid Salt, toluenesulfonate, nicotinate, lactate, urate, halogen-substituted acetate, phthalate, benzenesulfonate, malonate, butyrate, malate, and other organic acid saltsAmong these, the alkali metal salt is preferably at least one selected from the group consisting of phosphate, carbonate, and silicate from the viewpoint of cleaning performance.

  When the alkali metal salt is a polyvalent acid salt, the alkali metal salt may be partially converted to an alkali metal salt. The alkali metal salt is, for example, a trivalent phosphate, a first salt having one alkali metal and two hydrogens, a second salt having two alkali metals and one hydrogen, or three alkali metals. Any of the third salts having Further, the alkali metal salt may be any of an acidic salt, an alkaline salt, or a neutral salt. Among these, from the viewpoint of suppressing the corrosiveness to the mold, the alkali metal salt is preferably an alkaline salt or a neutral salt. As the alkali metal salt, a hydrate may be used.

  Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide and the like. Hydrates may be used as the alkali metal hydroxide.

As the specific cleaning agent, it is preferable to use at least one selected from the group consisting of trisodium phosphate, tripotassium phosphate, sodium hydroxide, and potassium hydroxide.
An alkali metal salt and an alkali metal hydroxide may be used individually by 1 type, and may use 2 or more types together.

  The content of the specific cleaning agent in the mold cleaning resin composition is 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the synthetic rubber from the viewpoint of cleaning performance and storage stability. Preferably, it is 0.5 to 5 parts by mass, more preferably 1 to 3 parts by mass.

  Further, the mass ratio of the content of the specific cleaning agent to the water content (the content of the specific cleaning agent / the water content) is from 0.1 to 5.0 in terms of cleaning performance and storage stability. Preferably, it is 0.3 or more and 3.0 or less, and more preferably 0.5 or more and 1.5 or less.

  The mold cleaning resin composition may contain other cleaning agent in addition to the specific cleaning agent. As another cleaning agent, it can select suitably from the cleaning agent used for the resin composition for metal mold | die cleaning. Examples of other cleaning agents include anionic surfactants, nonionic surfactants, metal soaps, and the like.

  When the resin composition for mold cleaning contains other cleaning agents, the content of the other cleaning agents is preferably 5 parts by mass or less with respect to 100 parts by mass of the synthetic rubber, and 3 parts by mass or less. More preferably. The lower limit of the content of other cleaning agents is not particularly limited, but is preferably 0.1 parts by mass or more with respect to 100 parts by mass of the synthetic rubber.

[filler]
The resin composition for mold cleaning contains silica. Silica functions as a filler, for example. There is no restriction | limiting in particular as a silica, A water-containing amorphous silica, an anhydrous amorphous silica, crystalline silica etc. can be mentioned, It can select suitably from commercially available silica. The silica may be wet silica or dry silica.
The water content of silica is preferably 6% by mass or more and 20% by mass or less, and more preferably 7% by mass or more and 10% by mass or less from the viewpoint of cleaning performance and storage stability. The water content of silica can be measured by a moisture vaporization-coulometric titration method using a Karl Fischer moisture meter, and the details are the same as the method for measuring the moisture content of the resin composition for mold cleaning.

  Silica preferably has an equilibrium moisture content of 5% by mass or more and 9% by mass or less at a relative humidity of 60% and 23 ° C. from the viewpoint of cleaning performance and storage stability. It is more preferably 8.5% by mass or less, and further preferably 6% by mass or more and 8% by mass or less.

  The bulk density of silica is preferably 30 g / l or more and 300 g / l or less, and more preferably 100 g / l or more and 300 g / l or less, from the viewpoint of the workability of the mold cleaning resin composition. The bulk density of silica is measured according to JIS K5105-18.

  Specific examples of commercially available silica include nip seal AQ, nip seal LP, nip seal NA, nip seal VN3 (manufactured by Tosoh Silica Co., Ltd.), and the like.

  From the viewpoint of cleaning performance and storage stability, the content of silica in the mold cleaning resin composition is preferably 10 parts by mass or more and 60 parts by mass or less with respect to 100 parts by mass of the synthetic rubber. It is more preferably 15 parts by mass or more and 50 parts by mass or less, and further preferably 20 parts by mass or more and 45 parts by mass or less.

  The mass ratio of the silica content to the water content (silica content / water content) is preferably 3.0 or more and 30 or less from the viewpoint of cleaning performance and storage stability. It is more preferably 0.0 or more and 20 or less, and further preferably 5.0 or more and 15 or less.

The resin composition for mold cleaning may contain a filler other than silica in addition to silica. The resin composition for mold cleaning contains a filler other than silica in addition to silica, so that a sufficient pressure is applied to the resin composition for mold cleaning during pressurization during mold cleaning. . When more sufficient pressure is applied to the mold cleaning resin composition, the mold cleaning resin composition spreads to every corner of the mold, and the inner surface of the mold does not wear out without wearing the mold. Dirt can be removed more efficiently. From such a viewpoint, the mold cleaning resin composition preferably contains a filler other than silica in addition to silica.
The filler other than silica may be either an organic filler or an inorganic filler, from the viewpoint of more efficiently removing dirt on the inner surface of the molding die without wearing the die, Inorganic fillers are more preferred.

Examples of the inorganic filler include alumina, calcium carbonate, aluminum hydroxide, and titanium oxide.
The filler has an appropriate hardness capable of removing dirt on the inner surface of the molding die without wearing the die, and from the viewpoint of applying sufficient pressure during pressurization during die cleaning, titanium oxide and At least one selected from the group consisting of calcium carbonate is preferred.
When the resin composition for mold cleaning contains a filler other than silica, the filler other than silica may be used alone or in combination of two or more.

  When the resin composition for mold cleaning contains a filler other than silica, the content is preferably 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the synthetic rubber. More preferably, it is at least 8 parts by weight.

[Vulcanizing agent]
The mold cleaning resin composition contains at least one vulcanizing agent. The vulcanizing agent is not particularly limited as long as it can crosslink synthetic rubber, and does not need to contain sulfur molecules in the compound.
In the present invention, vulcanization is a concept including both crosslinking of synthetic rubber by adding sulfur and crosslinking of synthetic rubber using peroxide.

  Examples of the vulcanizing agent include sulfur, sulfur monochloride, selenium, tellurium, zinc oxide, magnesium oxide, lead monoxide, sulfur-containing organic compounds, dithiocarbamates, oximes, tetrachloro-p-benzoquinone, dinitroso compounds, and modifications. A phenol resin, a polyamine, a peroxide, etc. are mentioned. Among these, as the vulcanizing agent, a peroxide is preferable. Moreover, as a peroxide, an organic peroxide or an inorganic peroxide may be sufficient, and an organic peroxide is more preferable. If the resin composition for mold cleaning contains an organic peroxide as a vulcanizing agent, there is no corrosive action of the mold during cleaning, which tends to occur when a vulcanizing agent containing sulfur is used, and the mold is released in a short time. The crosslinking of the unvulcanized rubber necessary for the process can proceed, and the crosslinking proceeds appropriately. Therefore, the cleaning resin composition after cleaning can be easily removed from the mold.

The organic peroxide only needs to have at least one divalent peroxide structure (—O—O—) and at least one hydrocarbon group.
The peroxide preferably has a one minute half-life temperature of 100 ° C. to 190 ° C. If the one-minute half-life temperature of the peroxide is higher than 190 ° C, the molding time becomes excessive when the mold is cleaned. Also, if the one-minute half-life temperature of the peroxide is higher than 190 ° C, if the mold temperature cannot be raised during mold cleaning, the mold cleaning resin composition does not sufficiently vulcanize and becomes brittle. There is a tendency for the workability of the system to decrease. When the peroxide half-life temperature is less than 100 ° C., vulcanization proceeds during the production of the mold cleaning resin composition and during the kneading process. There is a tendency not to follow.
The one-minute half-life temperature of the peroxide is more preferably 140 ° C to 190 ° C, and further preferably 145 ° C to 180 ° C.

The one-minute half-life temperature of peroxide is the temperature at which the peroxide concentration decreases to half of the initial value in one minute.
Specifically, the 1 minute half-life temperature can be determined as follows. First, when the peroxide is thermally decomposed at a certain temperature (T), the initial concentration of the peroxide is a, the decomposition amount of the peroxide is x, and time (t) and lna / (a By plotting the relationship of -x), the slope constant k of the obtained straight line is obtained. Next, the half-life at the temperature (T) can be obtained by substituting the previously obtained k into the definition kt _1/2 = ln2. Further, by repeating the same procedure, the half-life (t _1/2 ) at each temperature is obtained for each different temperature, and the obtained lnt _1/2 and 1 / T are plotted.
By extrapolating the straight line thus obtained, the temperature at which the half-life (t _1/2 ) is 1 minute, that is, the 1-minute half-life temperature can be obtained from the plotted graph.

  Examples of the organic peroxide include 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl- 2,5-bis (t-butylperoxy) hexane, t-butylperoxyneodecanoate, bis (3,5,5-trimethylhexanoyl) peroxide, 2,5-dimethyl-2,5-bis ( 2-ethylhexylperoxy) hexane, bis (4-methylbenzoyl) peroxide, benzoylperoxide, t-butylperoxybutyrate, 1,1-bis (t-butylperoxy) cyclohexane, t-hexylperoxyisopropyl Nomocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, n-butyl-4,4-bis (t-butyl Ruperoxy) valerate, dicumyl peroxide, bis-t-butyl peroxide and at least one selected from the group consisting of 1,1,3,3-tetramethylbutyl hydroperoxide are preferred, and 2,5-dimethyl- More preferable is at least one selected from the group consisting of 2,5-bis (t-butylperoxy) hexane and n-butyl-4,4-bis (t-butylperoxy) valerate.

  One vulcanizing agent may be used alone or two or more vulcanizing agents may be used in combination to adjust the vulcanization rate and the like in accordance with the design of the mold cleaning resin composition.

  When the synthetic rubber contained in the resin composition for mold cleaning is 100 parts by mass, the content of the vulcanizing agent in the resin composition for mold cleaning is 1 part by mass to 20 parts by mass. Preferably, it is 3 mass parts-10 mass parts, More preferably, it is 4 mass parts-8 mass parts. When the content of the vulcanizing agent in the resin composition for mold cleaning is 20 parts by mass or less, the mold cleaning resin composition after the cleaning is prevented from becoming brittle. The removal operation of the mold cleaning resin composition can be facilitated. When the content of the vulcanizing agent in the mold cleaning resin composition is 1 part by mass or more, vulcanization is sufficiently advanced, and the mold cleaning resin composition is prevented from sticking to the mold during cleaning. Therefore, the cleaning workability can be further improved.

In addition to the vulcanizing agent, the mold cleaning resin composition of the present invention may also contain a vulcanization aid. Examples of the vulcanization aid include acrylic acid monomer, sulfur, and zinc oxide. In particular, when a peroxide is used as the vulcanizing agent, at least one selected from the group consisting of sulfur and zinc oxide can be used as a vulcanizing aid.
The resin composition for mold cleaning of the present invention can also contain a vulcanization accelerator.
Examples of the vulcanization accelerator include guanidine, aldehyde-amine, aldehyde-ammonia, and thiazole vulcanization accelerators.
Examples of the guanidine vulcanization accelerator include diphenyl guanidine and triphenyl guanidine.
Examples of the aldehyde-amine vulcanization accelerator include formaldehyde-paratoluidine condensate and acetaldehyde-aniline condensate.
Examples of the thiazole vulcanization accelerator include 2-mercaptobenzothiazole and dibenzothiazyl disulfide.
In addition to the vulcanization accelerator, the mold cleaning resin composition of the present invention can also contain a vulcanization accelerator. Examples of the vulcanization acceleration aid include magnesia, resurge, lime and the like.
The kind and amount of the vulcanization aid, the vulcanization accelerator, and the vulcanization acceleration aid can be appropriately selected according to the design of the resin composition for mold cleaning.

[Other ingredients]
The mold cleaning resin composition of the present invention may contain other components such as an organic solvent, a lubricant, a mold release agent, and other additives as necessary.

(Organic solvent)
The mold cleaning resin composition may contain at least one organic solvent. There is no restriction | limiting in particular as an organic solvent, It can select suitably from the organic solvent used normally. Specific examples of the organic solvent include alcohol solvents such as polyhydric alcohols and polyhydric alcohol monoalkyl ethers; amide solvents; ketone solvents; ether solvents and the like. As the organic solvent, alcohol solvents are preferable, and polyhydric alcohols, polyhydric alcohol monoalkyl ethers, and the like are more preferable.

  The organic solvent is preferably a liquid when the mold is washed, more preferably has a low volatility when the mold is heated, and further preferably has a boiling point of 180 ° C. or higher. Specific examples of the solvent having a boiling point of 180 ° C. or higher include ethylene glycol monobutyl ether (boiling point: 188 ° C.), propylene glycol (boiling point: 187 ° C.), dipropylene glycol methyl ether (boiling point: 190 ° C.), diethylene glycol. And monomethyl ether (194 ° C.).

When the resin composition for mold cleaning contains an organic solvent, the content is preferably 5 parts by mass or less and more preferably 4 parts by mass or less with respect to 100 parts by mass of the synthetic rubber. Preferably, it is 3 parts by mass or less. The lower limit of the content of the organic solvent is not particularly limited, but is preferably 0.1 parts by mass or more with respect to 100 parts by mass of the synthetic rubber.
Moreover, an organic solvent may be used individually by 1 type, and may use 2 or more types together.

(Lubricant)
The mold cleaning resin composition may contain at least one lubricant. When the resin composition for mold cleaning contains a lubricant, the dispersibility of the compounding agent is improved in kneading during production.
Examples of the lubricant include metal soap lubricants, fatty acid ester lubricants, fatty acid lubricants, amide lubricants, hydrocarbon lubricants, anionic surfactants and the like.
Examples of the metal soap lubricant include zinc stearate, zinc myristate, aluminum stearate, calcium stearate and the like.
Examples of the fatty acid ester lubricant include butyl stearate, butyl laurate, stearyl stearate and the like.
Examples of fatty acid lubricants include stearic acid, behenic acid, and montanic acid.
Examples of the amide-based lubricant include ethylene bisstearamide, erucic acid amide, oleic acid amide, stearic acid amide, and behenic acid amide.
Examples of the hydrocarbon lubricant include liquid paraffin, paraffin wax, and synthetic polyethylene wax.
The lubricant is preferably at least one selected from the group consisting of stearic acid, behenic acid, and montanic acid, and more preferably stearic acid, from the viewpoint of improving the dispersion of the compounding agent during kneading during processing.
In the resin composition for mold cleaning, the lubricant may be used alone or in combination of two or more.
When the resin composition for metal mold | die cleaning contains a lubricant, the content is 0.1 mass%-20 mass% in a mass reference | standard in all the components contained in the resin composition for metal mold | die cleaning. It is preferable that it is 0.3 mass%-15 mass%. Further, the content of the lubricant is preferably 0.1 parts by mass or more and 20 parts by mass or less, and more preferably 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the synthetic rubber. preferable.

(Release agent)
The mold cleaning resin composition may contain at least one mold release agent. When the mold cleaning resin composition contains a release agent, the mold release effect after molding becomes excellent, and the workability during cleaning is improved.
Examples of the release agent include metal soap release agents, fatty acid ester release agents, synthetic waxes, and fatty acid amide release agents.
Examples of the metal soap release agent include calcium stearate, zinc stearate, and zinc myristate.
Commercially available fatty acid ester release agents, synthetic waxes, and fatty acid amide release agents include Rico Wax OP (manufactured by Clariant Japan Co., Ltd., partially saponified montanic acid ester), Roxyol G-78 (Emerio Oleochemicals Japan Ltd.) Company-made, polymer composite ester), Recolve H-4 (manufactured by Clariant Japan, modified hydrocarbon), Roxyol VPN881 (manufactured by Emery Oleochemicals Japan, mineral oil-based synthetic wax), fatty acid amide S (manufactured by Kao Corporation) , Fatty acid amide), Kao wax EB-P (manufactured by Kao Corporation, fatty acid amide), Alflow HT-50 (manufactured by NOF Corporation, fatty acid amide) and the like.
The type and amount of the release agent can be appropriately selected according to the design of the mold cleaning resin composition. Moreover, a mold release agent may be used individually by 1 type, and may use 2 or more types together.

(Other additives)
Other additives include known additives such as a plasticizer, a tackifier, a foaming agent, a coupling agent, and a scorch inhibitor. These are appropriately selected according to the purpose and the like.

[Preparation method]
It does not specifically limit as a preparation method of the resin composition for metal mold | die cleaning of this invention, A well-known method is employable.
As a method for preparing the mold cleaning resin composition of the present invention, for example, various components are kneaded using a pressure kneader with a jacket, a Banbury mixer, a roll mixer, etc., and a mold cleaning resin composition is obtained as a kneaded product. The preparation method which obtains a thing is mentioned. The obtained kneaded material can be formed into a sheet-like shape by passing through a pressure roll.
The shape of the mold cleaning resin composition can be appropriately selected depending on the mold to be used.
When the mold cleaning resin composition is molded into a sheet shape, the thickness of the sheet is not particularly limited, and can be set to a range of 3 mm to 10 mm, for example.

(Use)
The resin composition for mold cleaning of the present invention can be used for cleaning a molding mold. The type of the molding die is not particularly limited. Examples of the molding die include an optical member sealing die, a semiconductor material sealing die, and a rubber molding die. Specific examples of the molding die include a sealing die for a light emitting diode (LED), a sealing die for a semiconductor package, a rubber packing molding die, a thermosetting resin component molding die, and the like. . From the viewpoint of the molding temperature and curing time of the mold, the molding mold is preferably an LED sealing mold, a semiconductor package sealing mold, or the like.

  Further, the type of resin molded by the molding die (hereinafter sometimes abbreviated as “cleaning target resin”) is not particularly limited. Examples of the resin include an epoxy resin, a melamine resin, and a urea resin.

  Mold cleaning methods when using a mold cleaning resin composition are roughly classified into a transfer type and a compression type. The resin composition for mold cleaning of the present invention can be applied to both transfer type and compression type mold cleaning methods. The resin composition for mold cleaning of the present invention is more preferably applied to a compression-type mold cleaning method from the viewpoint of improving workability and shortening the cleaning work time.

  The mold cleaning resin composition may be used by heating the mold provided with the mold cleaning resin composition to a temperature corresponding to the molding temperature of the resin to be cleaned. The molding temperature is appropriately selected according to the type of the resin to be cleaned. For example, when the cleaning target resin is an epoxy resin, the mold may be heated to about 170 ° C.

<Die cleaning method>
The mold cleaning method of the present invention includes a step of applying the above-described mold cleaning resin composition of the present invention to the inner surface of a molding die (hereinafter also referred to as “applying step”), and mold cleaning. And a step of heating the mold provided with the resin composition (hereinafter also referred to as “heating step”). The mold cleaning method of the present invention may have other steps as necessary.
According to the mold cleaning resin composition of the present invention, the cleaning performance is sufficiently maintained even when a long period of time (for example, 6 months) has elapsed since the manufacture of the mold cleaning resin composition. Dirt on the mold can be removed.
Details of the molding die and the type of resin molded by the molding die are as described above.

[Granting process]
The applying step in the present invention is a step of applying the mold cleaning resin composition to the inner surface of the molding die. Details of the configuration, preferred mode, and the like of the mold cleaning resin composition used in this step are as described above.

The method for applying the mold cleaning resin composition to the inner surface of the molding die is not particularly limited, and a known method can be employed. Examples of the imparting method include known methods such as a compression molding method (compression molding method), a transfer molding method, and the like.
When the resin composition for mold cleaning is applied to the inner surface of the molding die, it can be applied so as to cover a part or the entire surface of the cavity portion of the molding die. At the time of molding, since the resin spreads over the entire inner surface of the molding die, in the mold cleaning method, it is preferable to apply a metal cleaning resin composition so as to cover the entire surface of the cavity portion of the molding die. .

[Heating process]
The heating step is a step of heating the mold cleaning resin composition applied to the inner surface of the molding die.
The heating method and heating conditions (temperature, time, number of times, etc.) are not particularly limited, and are known methods depending on the type of the resin to be cleaned and the composition of the mold cleaning resin composition of the present invention. And conditions can be selected as appropriate.

In the heating step of the present invention, for example, from the viewpoint of simplicity, the temperature is the same as the temperature when molding the resin to be cleaned with a mold, and is the same as the method when molding the resin to be cleaned with a mold. It is preferable to heat the mold cleaning resin composition by this method. Thereby, it is not necessary to heat or cool the mold for cleaning the mold, and the mold can be formed immediately after the mold cleaning.
As temperature in a heating process, it is preferable that it is 160 to 190 degreeC, and it is more preferable that it is 170 to 180 degreeC.

  The heating time is not particularly limited as long as the mold cleaning resin composition is sufficiently vulcanized and spreads over the entire inner surface of the mold. The heating time is preferably 150 seconds to 500 seconds, and more preferably 180 seconds to 360 seconds.

  In the mold cleaning method, the applying step and the heating step may be repeated a plurality of times. The number of repetitions of the applying step and the heating step (hereinafter also referred to as “shot number”) is preferably 2 to 7 times, and more preferably 2 to 5 times. In the mold cleaning method of the present invention, by using the mold cleaning resin composition, dirt can be removed from the mold with a small number of repetitions.

(Other processes)
The mold cleaning method of the present invention may be provided with other steps as necessary. Examples of other processes include a preheating process and a pre-pressurizing process.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded. Unless otherwise specified, “part” and “%” are based on mass.

<Example 1>
-Production of Resin Composition for Mold Cleaning A resin composition for mold cleaning according to Example 1 was produced by the following procedure.
In a 3000 ml jacketed pressure kneader, ethylene-propylene rubber (trade name EPT 4021H, manufactured by Mitsui Chemicals, ethylene: propylene composition ratio = 55: 45, Mooney viscosity ML _{1 + 4} (100 ° C.) 24, diene content 8.1 parts, iodine value 22) 40 parts, butadiene rubber (trade name BR01, manufactured by JSR Corporation, Mooney viscosity ML _{1 + 4} (100 ° C.) 45, specific gravity 0.9, cis 1,4 bond content 95% 60 parts) was added and kneaded under pressure for about 3 minutes while cooling.
The kneaded dough became bread dough, and the temperature of the kneaded dough became about 80 ° C.
Next, 2 parts of tripotassium phosphate as an alkali metal salt, 1 part of stearic acid (trade name F-3, manufactured by Kawaken Fine Chemical Co., Ltd.) as a lubricant, and a polymer composite ester (trade name LOXIOL as a release agent) 1 part of G78, manufactured by Emery Oleochemicals Japan Co., Ltd., 1 part of zinc stearate (trade name: Zn-St GF200, manufactured by Nippon Oil & Fats Co., Ltd.), and modified hydrocarbons (trade name: Licolub H4, manufactured by Clariant Japan Co., Ltd.) ) And 0.5 parts of water-containing amorphous silica (trade name: NIPSEAL AQ, manufactured by Tosoh Silica Co., Ltd., water content 8%, equilibrium water content 7% (relative humidity 60%, 23 ° C.)) 30 parts and 5 parts of titanium oxide (trade name CR-80, manufactured by Ishihara Sangyo Co., Ltd.) were added and kneaded for about 3 minutes.
Finally, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane (trade name Perhexa 25B-40, manufactured by NOF CORPORATION, 1 minute half-life temperature 179.8 ° C.) as a vulcanizing agent 6 parts were added and kneaded for about 1 minute.
During this period, the temperature of the kneaded product was adjusted so as not to exceed 100 ° C.
The obtained kneaded material was quickly passed through a pressure roll, processed into a sheet shape, cooled to 25 ° C. or lower, and formed into a sheet shape having a thickness of 7 mm to obtain the resin composition for mold cleaning of Example 1. It was.

<Cleaning performance evaluation>
QFP28 × 28 (6 pots-12 cavities) using a commercially available biphenyl epoxy resin molding material (trade name EME-G700, manufactured by Sumitomo Bakelite Co., Ltd.) and a plunger with a tip made of cemented carbide. The mold was molded for 500 shots to form a stain on the inner surface of the mold.
The number of moldings required to remove the dirt on the inner surface of the molding die by repeatedly compression molding the mold cleaning resin composition obtained above using the molding die having a dirt on the inner surface. The cleaning performance was evaluated based on the number of shots. In addition, the removal state of the stain | pollution | contamination of the internal surface of a shaping die was determined visually. In addition, the mold cleaning resin composition required until the dirt on the inner surface of the molding die can be removed is acceptable if the number of repeated moldings (the number of cleaning completion shots) is 4 or less.

<Storage stability evaluation>
The mold cleaning resin composition obtained above was allowed to stand for 6 months in an environment at 23 ° C., and then the cleaning performance was evaluated in the same manner as the test performed in the cleaning performance evaluation. The resin composition for mold cleaning was sealed and stored in an aluminum vapor-deposited polyethylene bag with a chuck in order to prevent a decrease in moisture content and deterioration due to light irradiation.
Moreover, the vulcanizability at the time of washing was evaluated by observing the degree of sticking of the mold cleaning resin composition to the mold. The evaluation criteria are as follows: -Evaluation criteria-
A: Sticking to the mold did not occur.
B: Sticking to the mold occurred, but it was easily removed by hand.
C: Sticking to the mold occurred, and when peeled off by hand, the resin composition was cracked and a part remained on the mold surface.

<Examples 2-8, Comparative Examples 1-3>
In the production of the mold cleaning resin composition of Example 1, Examples 2 to 8 and Comparative Examples 1 to 3 were carried out in the same manner as in Example 1 except that the blending components were changed as described in Table 1. A mold cleaning resin composition was obtained. Table 1 shows the evaluation results of the cleaning performance evaluation and the storage stability evaluation. In Table 1, “-” indicates that it is not blended. Details of each component are as follows.

Ethylene-propylene rubber EPT 4021H: manufactured by Mitsui Chemicals, ethylene / propylene ratio = 55.5 / 44.5, Mooney viscosity ML _{1 + 4} (100 ° C.) 24, diene content 8.1%, iodine value 22
Butadiene rubber JSR BR01: manufactured by JSR Corporation, Mooney viscosity ML _{1 + 4} (100 ° C.) 45, cis 1,4 bond content 95%,
Nitrile rubber JSR N239SV: manufactured by JSR Corporation, Mooney viscosity ML _{1 + 4} (100 ° C.) 30, content rate of acrylonitrile bond 34%
Styrene-butadiene rubber JSR 1502: manufactured by JSR Corporation, Mooney viscosity ML _{1 + 4} (100 ° C.) 52, styrene bond content 23.5%

Filler Nip seal AQ: Silica, manufactured by Tosoh Silica Co., Ltd., water content 8%, equilibrium moisture content 7% (relative humidity 60%, 23 ° C.)
Nip seal LP: Silica, manufactured by Tosoh Silica Co., Ltd., water content 6%, equilibrium moisture content 7% (relative humidity 60%, 23 ° C.)
Nip seal NA: Silica, manufactured by Tosoh Silica Co., Ltd., water content 6%
Leolosil DM-10: Silica, manufactured by Tokuyama Corporation, water content 0.1%
CR-80: Titanium oxide, manufactured by Ishihara Sangyo Co., Ltd.

Lubricant F-3: Stearic acid, vulcanizing agent manufactured by Kawaken Fine Chemical Co., Ltd. Perhexa 25B-40: manufactured by NOF Corporation, 1 minute half-life temperature 179.8 ° C
Perhexa V-40: NOF Corporation, 1 minute half-life temperature 172.5 ° C
Release agent LOXIOL G78: Polymer composite ester, manufactured by Emery Oleochemicals Japan Co., Ltd. Zn-St GF200: Zinc stearate, manufactured by NOF Corporation Licolub H4: Modified hydrocarbon, manufactured by Clariant Japan Co., Ltd.

  From the result of Table 1, it became clear that the resin composition for metal mold | die cleaning of this invention has the outstanding cleaning performance. Moreover, it turns out that the resin composition for metal mold | die cleaning of this invention has the outstanding storage stability.

The disclosure of Japanese application 2013-017672 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards described in this specification are specifically and individually incorporated by reference as if individual documents, patent applications, and technical standards were incorporated by reference. To the extent it is incorporated herein by reference.

Claims (9)

Synthetic rubber,
A compound selected from the group consisting of alkali metal salts and alkali metal hydroxides;
Silica,
A vulcanizing agent,
The resin composition for metal mold | die cleaning whose content rate of a water | moisture content is 0.20 mass% or more and 3.50 mass% or less.   The resin composition for mold cleaning according to claim 1, wherein the synthetic rubber includes ethylene-propylene rubber and butadiene rubber.   3. The mold cleaning resin composition according to claim 1, wherein the silica content is 10 parts by mass or more and 60 parts by mass or less with respect to 100 parts by mass of the synthetic rubber.   The mass ratio of the content of the compound selected from the group consisting of the alkali metal salt and the alkali metal hydroxide with respect to the water content is 0.1 or more and 5.0 or less. The resin composition for metal mold | die cleaning of any one of Claims 1.   The resin composition for mold cleaning according to any one of claims 1 to 4, wherein a mass ratio of the silica content to the moisture content is 3 or more and 30 or less.   The mold cleaning resin composition according to any one of claims 1 to 5, wherein the silica has an equilibrium moisture content of 5% by mass to 9% by mass at a relative humidity of 60% and a temperature of 23 ° C. .   The content of a compound selected from the group consisting of the alkali metal salt and alkali metal hydroxide is 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the synthetic rubber. The resin composition for metal mold | die cleaning of any one of -6.   The mold cleaning according to any one of claims 1 to 7, wherein a content of the vulcanizing agent is 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the synthetic rubber. Resin composition. The process of providing the resin composition for metal mold | die cleaning of any one of Claims 1-8 to the internal surface of a shaping die,
Heating the molding die provided with the mold cleaning resin composition;
Mold cleaning method including.