TWI664065B - Rubber composition of excellent cavity-filling and rubber sheet for releasing a mold - Google Patents

Abstract

The present invention discloses a rubber composition comprising the following components: an uncrosslinked rubber including butadiene rubber, ethylene-propylene diene monomer rubber, and a polymer specifically used to improve the mobility of the rubber composition in a mold Additives; cleaners or waxes; hardeners; and inorganic fillers.

Description

Good cavity filled rubber composition and rubber plate for demolding

The invention relates to a rubber composition which is used to remove contaminants remaining in a mold during a continuous molding process of a thermoplastic resin, and to provide release properties to the mold. In particular, the present invention relates to a rubber composition having excellent filling properties by combining specific components to improve the mobility of the rubber composition in a mold.

The thermoplastic resin used as a raw material is caused by compression molding and heating to cause contaminants introduced during processing and carbides of certain molding products to remain in the mold. These pollutants and carbides become pollutants in the subsequent re-copying process, which causes defects in some of the molded finished products and damages the product quality of the entire continuous molding process. Therefore, an operation (so-called "cleaning operation") for removing contaminants remaining in a mold should be performed after performing a molding operation for a fixed time or at a fixed frequency.

As a method of efficiently performing such a cleaning operation, a plate including a cleaning component has been developed. Actively used in these panels Research on its composition. US Patent No. 3,476,599 proposes a thermoplastic resin composition for cleaning molds, in which a thermoplastic resin is used as a matrix, and an amino alcohol-based compound having an amine group and a hydroxyl group is added as a cleaning agent. However, in the hardening process of the sheet used for cleaning, the amine group of the amine-based compound as a cleaning agent is decomposed, so an amine-based gas is generated, and odor and smoke are generated.

Therefore, it is recommended to use a rubber composition for cleaning molds, in which an uncrosslinked rubber including butadiene rubber (BR) and ethylene-propylene diene monomer (EPDM) rubber is used as a matrix and an imidazole-based or The imidazoline-based compound is used as a cleaning agent, and therefore, the aforementioned problems are solved to some extent. However, the odor is generated due to the decomposition of the hardener (mainly organic peroxide) used in the uncrosslinked rubber. Therefore, the problem has not been fundamentally solved, and the improvement of the cleaning power is limited because the cleaning agent is limited to compounds mainly composed of imidazole or mainly imidazoline.

At the same time, because of repeated operations, the operation of providing release properties to the mold (so-called "release operation") is necessary for the cleaning operation and easy desorption of the thermoplastic resin.

In particular, in the EMC molding process for manufacturing semiconductors, the detachment operation directly affects the quality of the semiconductor device. Therefore, when the release property provided on the surface of the mold is lower than a certain level, all products may be inferior and may take a lot of time to repair. Therefore, research has been conducted to provide the release property to the mold and maintain the release property for a long time.

Traditionally, in order to provide release properties to the mold, a powdered natural palm wax or dimethyl silicone oil is mixed with a solvent such as a nucleic acid A method of filling the mixture into a high-pressure spray container and directly spraying the mold surface, a method of applying an epoxy compound compounded with a large amount of wax by a low-pressure transfer molding method, and the like.

However, when these methods are used, the release properties are destroyed due to the uneven coating in the mold, the use of nucleic acid solvents causes environmental pollution or the cost is too high due to the low-pressure transfer molding method.

As a solution to these problems, it is proposed to use a die coating method in which an uncrosslinked rubber including a butadiene rubber (BR) and an ethylene-propylene diene monomer (EPDM) rubber is used as a substrate as a cleaning operation, The coating is performed by dissolving the coating components (wax and additives) using a rubber composition including a coating component instead of a cleaning agent (including inorganic fillers, hardeners, etc.) to coat the mold according to the rubber hardening.

In particular, FIG. 1 is a schematic diagram illustrating the release mechanism and incomplete filling properties of a conventional rubber composition. FIG. 2 is a view illustrating the release of the crosslinked rubber from the mold by the method of FIG. 1. FIG. FIG. 3 is a schematic diagram illustrating a method of manufacturing an EMC product from the mold coated by the method of FIG. 1 and a defect of the EMC product due to incomplete filling properties.

Referring to FIGS. 1 to 3, a release rubber composition 120 including an uncrosslinked rubber 121 and a coating component 122 is disposed in a mold 110, and then crosslinked by hardening at about 175 to 180 ° C. When the crosslinked rubber 130 is taken out from the inside of the mold 110, the inside is coated with the coating composition 122.

However, this method has problems such as product defects and mold contamination due to reduced release properties (in which the rubber prepared from the composition is not easily detached from the mold 110), and the release properties in the mold due to coating release The incomplete filling phenomenon when the agent is removed (where the rubber composition does not completely fill the zigzag portion 110a inside the mold) is damaged.

Therefore, there is a great need for a rubber composition containing a release agent, which can reduce the manufacturing cost in a cleaning operation or a coating operation, can provide an environmentally friendly operating environment, and exhibit excellent cleaning properties or mold release and filling properties.

Therefore, the present invention has been completed to solve the aforementioned and other technical issues that have yet to be resolved.

As described below, the rubber composition of the present invention is composed of a composition of specific ingredients. It is confirmed that when the rubber composition is used in a mold for molding, the rubber for cleaning and the rubber prepared from the rubber composition The present invention has completed the cleaning power or mold release power and filling property of the detached rubber.

According to one aspect of the present invention, a rubber composition for improving the release property of a molding die is provided. The rubber composition includes: an uncrosslinked rubber. The rubber includes 60 to 100 parts by weight of a butadiene rubber (BR), 0 to 40 parts by weight of an ethylene-propylene diene monomer (EPDM) rubber and 5 to 40 parts by weight of a polymer additive having a melting point (T _m ) of 100 ° C. or lower; and 100 parts by weight of the uncrosslinked The rubber is a mixture of 5 to 60 parts by weight of a wax, 0.5 to 10 parts by weight of a hardener, and 5 to 110 parts by weight of an inorganic filler and an adsorbent.

According to another aspect of the present invention, there is provided a rubber composition including the following components: an uncrosslinked rubber, the rubber comprising 60 to 100 parts by weight of a butadiene rubber (BR), and 0 to 40 parts by weight of ethylene- Propylene diene monomer (EPDM) rubber and 5 to 40 parts by weight of a polymer additive having a melting point (T _m ) of 100 ° C. or lower; and 5 to 60 parts by weight based on 100 parts by weight of the uncrosslinked rubber A cleaning agent, a mixture of 0.5 to 10 parts by weight of a hardener, and 5 to 110 parts by weight of an inorganic filler and an adsorbent.

In this case, the melting point means a peak point analyzed by differential scanning calorimetry (DSC), and the uncrosslinked rubber means a crosslink in a mold through the action of a hardener upon application of heat and pressure, and a cleaning agent. Ingredients cleaned inside the mold or removed after coating the inside with wax and additives.

In the rubber composition of the present invention, a polymer additive that satisfies specific conditions is additionally added to the butadiene rubber and ethylene-propylene diene monomer rubber as a matrix of a conventional uncrosslinked rubber, thereby improving the mobility of the rubber composition. To improve the filling properties of rubber in the mold. Therefore, the inside of the mold can be completely coated with wax and additives, so that the release properties of the rubber prepared from the composition can be improved. In addition, the release properties of the rubber are improved, and the remaining rubber used for cleaning can be minimized in the mold after the cleaning operation. In addition, the release rate of the cleaning agent from the crosslinked rubber can be increased, so the inside of the mold can be completely cleaned, thereby increasing the mold cleaning power.

As described above, the uncrosslinked rubber in the rubber composition may not include ethylene-propylene diene monomer rubber, or may include 40 parts by weight or less, especially 5 to 30 parts by weight of ethylene-propylene diene. Olefin monomer rubber.

The polymer additive may be included in an amount of 5 to 40 parts by weight, especially 10 to 30 parts by weight.

When the uncrosslinked rubber includes the polymer additive in an amount of more than 40 parts by weight, the degree of crosslinking of the rubber prepared from the rubber composition for release or cleaning is reduced. Therefore, the cleaning agent does not act on the pollutants in the mold, so the cleaning power is reduced or the coating amount of wax and additives is reduced, thereby destroying the release property. On the other hand, when the uncrosslinked rubber includes the polymer additive in an amount of less than 5 parts by weight, it is difficult to exhibit the desired filling and release properties of the present invention.

In a specific embodiment, the melting point of the polymer additive may be 40 ° C to 100 ° C, especially 40 ° C to 90 ° C.

When the melting point of the polymer is higher than 100 ° C., the manufacturing temperature is increased, and therefore, when an uncrosslinked rubber product is manufactured, a coking phenomenon (premature crosslinking) occurs, and product defects may occur. On the other hand, when the melting point of the polymer additive is lower than 40 ° C, the surface of the product becomes sticky. Therefore, the product sticks to the surface of the device during manufacturing, making it difficult to produce the product and destroying the filling properties due to the decrease in product hardness.

In a specific embodiment, the polymer additive may be a polyolefin-based elastomer, or a copolymer composed of a polyolefin monomer and an acrylic monomer and an ionic polymer thereof, or a polyolefin monomer and acrylic acid Copolymer of ester monomers.

The polyolefin-based elastomer is not particularly limited, as long as the conditions for the aforementioned polymer additive are met, or may be one or more selected from the group consisting of: very low density polyethylene (VLDPE); Butene; poly-4-methyl-1-pentene (TPX); propylene, butene, hexene, and / or copolymers of octene and ethylene; and thermoplastic elastomers based on olefins. Therefore, copolymers composed of low-density polyethylene (LDPE), very low-density polyethylene (VLDPE) or polyolefin monomers and acrylic monomers, and monomers and acrylic monomers of ionic polymers or polyolefins thereof Copolymers composed of ester monomers (with melting points above 100 ° C) may not be suitable for use in the polymer additives of the present invention.

Copolymers composed of polyolefin monomers and acrylic monomers and copolymers composed of ionic polymers or polyolefin monomers and acrylate monomers are particularly limited as long as their melting point (T _m ) is 100 ° C or Further, the acrylate monomer may be one or more selected from the group consisting of ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid ester copolymer (EMAA), and its ionic polymer. , Ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-alkyl acrylate-acrylate copolymer, ethylene-alkyl methacrylate-methacrylate copolymer, ethylene- Butyl acrylate copolymer (EBA) and ethylene-vinyl acetate copolymer (EVA).

The copolymer may include, for example, 60 to 96% by weight of a monomer for polyolefins based on 100% by weight of the copolymer, and 4 to 40% by weight of acrylic acid or acrylate-based or vinyl acetate-based Of the monomer.

In a specific embodiment, as a polymer additive The polyolefin elastomer may be an ethylene-propylene copolymer or an ethylene-butene copolymer prepared by reacting an ethylene monomer with a propylene monomer or a butene monomer. The ethylene-propylene copolymer or the ethylene-butene copolymer naturally satisfies the conditions of the aforementioned polymer additive.

Meanwhile, the wax and the additive for providing the release property to the mold are basically not particularly limited as long as the wax and the additive can provide the release property. For example, the wax is a mixture of polyethylene and a slip aid, and has a weight average molecular weight of 200 to 3000. In this case, the slip aid for improving the mold release property is not particularly limited, and may be, for example, erucamide, oleylamine, stearylamine, behenamine, ethylene-bis-stearylamine, ethylene- Bis-oleamide, stearyl erucamide and the like.

The content of the wax and the additive may be 5 to 60 parts by weight based on 100 parts by weight of the uncrosslinked rubber as described above. When the content is less than 5 parts by weight, it is difficult to provide sufficient release properties to the mold. When the content is more than 60 parts by weight, the wax remaining on the surface of the mold becomes dirty and may become another source of pollution.

At this time, the cleaning agent for releasing pollutants from the mold is basically not particularly limited, as long as the function of releasing pollutants from the mold is performed, and examples thereof include two or more selected from the group consisting of Mixture of dichloromethane, diethylene glycol monobutyl ether, acetaldehyde, ethyl diethylene glycol, acetic acid, formic acid, ammonium dodecylbenzenesulfonate, 1-methoxy-2-propanol, methanol , Dodecylbenzenesulfonic acid, acetone, 2- (2-butoxyethoxy) ethanol diethylene glycol monobutyl ether (BDG), ethanolamine (MEA), 2-aminoethanol (MEA), 2- Diethylaminoethanol (DEAE), 2-methoxyethanol (EM), 2-ethoxyethyl Alcohol, 2-propoxyethanol, dimethylsulfinium (DMS), 2- (2-aminoethylamino) ethanol (2- (2-aminoethylamino) ethanol), N-methyl N-pyrrolidone (NMP), 1-phenoxy-2-propanol (PGPhE), isopropylidene acetone, 4-hydroxy-4-methyl-2-pentanone and amine alcohol-based compounds, Especially a mixture selected from the group consisting of two or more of the following: methylene chloride, acetone, 2-methoxyethanol (EM), dimethylsulfinium (DMS), N-methylpyrrole Pyridone (NMP), 1-phenoxy-2-propanol (PGPhE), isopropylidene acetone, and 4-hydroxy-4-methyl-2-pentanone.

In addition, the present inventors have determined that when a mixture composed of a composition of different cleaning compounds is used as a cleaning agent, a cleaning effect that is significantly superior to that when a single cleaning compound is used as a cleaning agent is exhibited. For this reason, a mixture comprising two or more different types of cleaning compounds is specifically used as a cleaning agent.

At this time, the ratio between the mixed cleaning compounds may be 1:99 to 99: 1 by weight, especially 5:95 to 95: 5.

The content of the cleaning agent is 0.5 to 60 parts by weight as described above. When the content is less than 0.5 parts by weight, it is difficult to obtain sufficient cleaning power. When the content is more than 60 parts by weight, the cleaning agent remaining on the surface of the mold becomes dirty and may become another source of pollution.

At the same time, the present inventors confirmed that when the cleaning agent further contains a cleaning supplement, the cleaning power is further improved. Therefore, the rubber composition may further include a cleaning supplement, and the cleaning supplement may be, in particular, a nonionic surfactant.

In a specific embodiment, the non-ionic surfactant may be a compound mainly composed of alkylamine ethoxylate having a molecular formula of C ₂₃ H ₃₈ N ₂ O ₈ . The alkylamine ethoxylate having the molecular formula C ₂₃ H ₃₈ N ₂ O ₈ is a material having reversible surface activity, and the amine ethoxylate acts as a surfactant in an alkaline solution. However, amine ethoxylates lose surface activity in acidic solutions. These properties help to separate the emulsified oil from the aqueous material, and therefore, the compound is known to be useful in industrial cleaning or metal cleaning.

In another specific embodiment, the non-ionic surfactant may be a compound mainly composed of alkylphenol ethoxylates, especially a compound mainly composed of octylphenol ethoxylates, as shown in Formula 1 below. R in Formula 1 is C ₈ . In the following formula 1, x may be an integer from 3 to 10.

Where R is a C ₄ to C ₁₀ alkyl group and x is an integer from 1 to 55.

The compound mainly composed of alkylphenol ethoxylate shown in Formula 1 is a material having wetting, cleaning and oil emulsifying properties in aqueous materials, and can be used in a wide temperature range, and can be used in all cleaning compounds Types such as liquid, paste, powder, etc. Therefore, the compound can be used in various industrial cleaners, including household soft cleaners and cleaners for heavy industrial machinery. In particular, the compound is known to have excellent cleaning effects on hard surfaces and metals.

In another specific embodiment, the non-ionic surfactant may be an alcohol alkoxide-based compound having a molecular formula C ₁₂ H ₃₀ O ₂ , especially a material represented by the following formula 2.

[CH ₃ CH ₂ OCH ₂ (CH ₂ ) ₆ CH ₂ OH] * [CH ₄ ] * [CH ₄ ] (2)

The alcohol-alkoxide-based compound having the molecular formula of C ₁₂ H ₃₀ O ₂ is a water-soluble nonionic surfactant having excellent properties and processability, and has properties such as excellent wetting, cleaning properties, and fast dissolution rate. Characteristics. Because of these characteristics, the compound is known as a cleaner or degreaser for hard surfaces and metals, and for household and various industrial cleaners.

The actual mechanism of the interaction between the cleaning supplement and the cleaning agent has not been known, but it can be determined that the experimental example described below, when using the cleaning agent and the cleaning supplement at the same time, the amount of cleaning is increased, and the cleaning power increases. Therefore, the rubber composition of the present invention including cleaning supplements has a cleaning power superior to or similar to the conventional rubber composition even if the amount of the cleaning agent is reduced.

The content of the cleaning supplement may be 0.1 to 7 parts by weight, especially 0.5 to 3 parts by weight. When the content is less than 0.1 part by weight, it is difficult to obtain enhanced cleaning power. When the content is more than 7 parts by weight, the cleaning supplement may become another source of pollution without further increasing the cleaning power.

At least one of the cleaning agent and the cleaning supplement may be included in the inorganic filler and the adsorbent in the coated state, the soaked state, and the coated and soaked state (detailed below) because it is mainly present in a liquid state. It is quite difficult for a detergent or cleaning supplement to knead uniformly with uncrosslinked rubber.

In addition, the inventors have determined that when cleaning agents and cleaning supplements further include water and / or bulking agents (alcohol-based materials such as methanol or ethanol), the cleaning power is further increased.

The general cleaning operation is to place the monomer for cleaning the mold prepared from the rubber composition on the mold, and apply the 15kgf / cm ² to 100kgf / cm ² at 150 to 200 ° C for 2 to 10 minutes to make the monomer Hardened into the shape of the mold. In this case, adding the expansion agent together with the cleaning agent can further improve the cleaning power. It is assumed that the reason for this phenomenon is that the temperature applied to the monomer during the cleaning operation is higher than the boiling point of the expansion agent, and the expansion agent evaporates at the boiling point or higher, which promotes the dispersal of the cleaning agent present inside the monomer to the surface and disperses. Effect (blooming effect). That is, when only the cleaning agent is used, the cleaning agent existing inside the monomer and thus unable to effectively function against the pollutant is dissolved to the surface, thereby coming into contact with the pollutant.

When the rubber composition of the present invention further includes an expansion agent, the content of the expansion agent may be 1 to 10 parts by weight based on 100 parts by weight of the uncrosslinked rubber. When the content is less than 1 part by weight, it may be difficult to obtain an effect. When the content is more than 10 parts by weight, it may be difficult to perform a kneading operation and the mold surface may be contaminated.

In addition, the present inventors confirmed that when a strong acid such as hydrochloric acid, sulfuric acid, nitric acid, bromic acid, etc. or a strong base such as sodium hydroxide, potassium hydroxide, etc. is used with a cleaning agent and a cleaning supplement, a further increased cleaning effect is obtained. It is assumed that a strong acid or alkali added to a cleaning agent is used as a catalyst (hereinafter often referred to as a "cleaning catalyst"). That is, in the case of a rubber composition for cleaning a mold including only a cleaning agent and a cleaning supplement, the cleaning is performed in such a manner that the cleaning agent directly dissolves the contaminants. Alternatively, the cleaning method is such that the detergent penetrates between the mold and the pollutants, so that the adhesion between the mold and the pollutants is reduced. In this state, the pollutants adhere to the crosslinked rubber and are moved from there. except. On the other hand, when the cleaning catalyst is used together with a cleaning agent and a cleaning supplement, the cleaning catalyst promotes the pulverization of pollutants, thus increasing the permeability of the cleaning agent and the cleaning supplement, and greatly improving the cleaning power.

The cleaning catalyst may include an amount of 0.5 to 20 parts by weight relative to 100 parts by weight of the cleaning agent. As the cleaning catalyst, the aforementioned strong acid or strong base can be selectively used, especially KOH.

As described above, the content of the cleaning agent including the cleaning catalyst may be 0.5 to 60 parts by weight.

The uncrosslinked rubber is hardened by heat and pressure crosslinking, and the hardener initiates the hardening. As the uncrosslinked rubber, organic peroxides, phenol resins, sulfur, and the like can be used, and in particular, organic peroxides can be used. The type of organic peroxide can be selected according to the temperature when considering the half-life of the mold temperature. Examples of organic peroxides include, but are not limited to, 2,5-dimethyl-2,5-bis- (third butyl peroxy), d-third butyl peroxide, 2,5-dimethyl -2,5-bis- (third butylperoxy) -hexane, third butylcumyl peroxide, bis- (third butylperoxy-isopropyl) -benzene, dicumyl Peroxy, 4,4-di-tert-butylperoxy-n-butylvalerate, tert-butylperoxybenzoate, 1,1-di-tert-butylperoxy-3,3, 5-trimethylcyclohexane, di-benzylidene peroxide (di-benzylidene peroxide), bis- (2,4-dichlorobenzylidene) -peroxide (bis- (2, 4-dichlorobenzylfluorenyl) -peroxide) and the like. Among them, bis- (third butyl peroxy-isopropyl) -benzene and 4,4-di-third butyl peroxy-n-butyl valerate are particularly advantageous for use with ethylene-propylene diene monomers. (EPDM) and butyl rubber (BR) are used in clean mixed rubber compositions.

The content of hardener is 100 parts by weight The rubber meter may be 0.5 to 10 parts by weight. When the content is less than 0.5 parts by weight, initiation of hardening or acceleration of hardening may not be completed. When the content is more than 10 parts by weight, excessive cross-linking occurs, and overall mechanical properties are deteriorated, such as a significant reduction in tear strength.

The inorganic filler increases the maintenance of the balance between the components of the composition according to the increase in viscosity. That is, the viscosity of the composition is reduced by adding a wax or a detergent to the uncrosslinked rubber, and the Meng viscosity can be increased by adding an inorganic filler to maintain the balance between the components. Examples of the inorganic filler include silicon dioxide, talc, alumina, potassium carbonate, calcium carbonate, aluminum hydroxide, titanium oxide, carbon black, and the like.

In some cases, the rubber composition of the present invention may further include an adsorbent to remove through adsorption during a cleaning operation (an operation of applying heat and pressure after a mold rubber plate prepared from the rubber composition of the present invention is input into a mold) or a release operation. (Operation of applying heat and pressure after the release rubber sheet prepared from the rubber composition of the present invention is input into a mold) various odors and smoke components occurring in the operation.

The adsorbent has high adsorption capacity and a large specific surface area relative to odor and smoke components. Odors and fumes generated during operation are unavoidable caused by various factors such as the decomposition of hardeners and detergents. Problems related thereto can be solved by using the composition of the present invention including an adsorbent having a high specific surface area. The sorbent has a specific surface area of at least 200 m ² / g or more. In addition, an adsorbent having micropores can exhibit excellent adsorption ability.

Examples of the adsorbent include clay (mud), silicone, activated carbon, zeolite, ion exchange resin, acid gypsum, and the like. In some cases, a mixture of two or more of them may be used. The adsorbent used in the present invention may be zeolite, silica gel, or acidic gypsum, which is colorless and has a specific surface area of 200 m ² / g or more, and more particularly, finely powdered silica gel or zeolite. The particles of the micronized silicon rubber are pulverized to a size of several millimeters (mm) to micrometers (μm), so the problem of kneading with uncrosslinked rubber is solved. Because the X-type zeolite and the Y-type zeolite have high specific surface area (about 500 m ² / g or more) but are expensive, they are mixed with the A-type zeolite, thereby reducing the production cost of the composition of the present invention. At the same time, because activated carbon and ion exchange resins have a large specific surface area (about 600 m ² / g or more), they exhibit excellent adsorption capabilities, but they are black in color and expensive. Therefore, it is preferable to use activated carbon and ion exchange resin together with other adsorption components.

In addition, the adsorbent also functions as an inorganic filler. The content of the adsorbent and the inorganic filler may be 5 to 110 parts by weight based on 100 parts by weight of the uncrosslinked rubber.

In addition, the rubber composition of the present invention may include other compounds or mixtures so long as their properties are not impaired.

110‧‧‧mould

110a‧‧‧Zigzag part

120‧‧‧ release rubber composition

121‧‧‧Uncrosslinked rubber

122‧‧‧ Coating composition

130‧‧‧ Crosslinked rubber

210‧‧‧Mould

210a‧‧‧Zigzag part

220‧‧‧ Release rubber composition

221‧‧‧Uncrosslinked rubber

222‧‧‧ Coating composition

230‧‧‧ Crosslinked rubber

The foregoing and other objects, features, and other advantages of the present invention can be more clearly understood from the following detailed description in conjunction with the accompanying drawings, in which: FIG. 1 is a schematic diagram illustrating the detachment mechanism and incomplete filling properties of a conventional rubber composition; The rubber is removed from the mold via the method of FIG. 1 3; FIG. 3 is a schematic diagram illustrating a method of manufacturing an EMC product using the mold coated by the method of FIG. 1 and a defect caused by the incomplete filling property of the EMC product.

4 is a schematic diagram illustrating a release mechanism of a rubber composition having excellent filling and demolding properties according to a specific embodiment of the present invention; and FIG. 5 is an image illustrating the release of a crosslinked rubber from a mold according to the method of FIG. 4.

[Invention Mode]

The present invention will now be described in more detail with reference to the accompanying drawings. These examples are for illustration only and do not limit the scope and spirit of the invention.

FIG. 4 is a schematic diagram illustrating a release mechanism of a rubber composition having excellent filling and demolding properties according to a specific embodiment of the present invention, and FIG. 5 is an image illustrating the release of a crosslinked rubber from a mold according to the method of FIG. 4.

Referring to FIGS. 4 to 5, a release rubber composition 220 including an uncrosslinked rubber 221 and a coating component 222 is disposed in a mold 210, and then crosslinked by hardening at about 175 to 180 ° C. When the crosslinked rubber 230 is taken out, the inside of the mold 210 is coated with a coating component 222.

At this time, since the zigzag portion 210a inside the mold is also sufficiently filled with the rubber composition, unlike the conventional rubber composition, incomplete filling does not occur, and therefore excellent mold release properties are exhibited. Therefore, as illustrated in FIG. 5, a well-formed crosslinked rubber is released from the mold.

The present invention will now be described in more detail with reference to the following examples. These examples are for illustration only and do not limit the scope and spirit of the invention.

<Example 1>

300 g of ethylene-propylene diene monomer (EPDM) rubber and 200 g of very low density polyethylene (VLDPE) were mixed with 700 g of butadiene rubber (BR). Knead the hardener (30g 4,4-di-third-butyl-peroxy-n-butylvalerate), inorganic filler (300g silica, 50g titanium oxide) and wax in a kneader and roller mill. (80g polyethylene, 20g slip aid). In this case, the density of the very low density polyethylene (VLDPE) is 0.87, and its melting point is 60 ° C.

<Example 2>

The mixture was prepared in the same manner as in Example 1, except that 200 g of an ethylene-methacrylate copolymer (EMAA) ionic polymer produced by reacting an ethylene monomer and an acrylic monomer at a weight ratio of 9: 1 was used. , Not very low density polyethylene (VLDPE). In this case, the density of the ethylene-methacrylate copolymer (EMAA) ionic polymer is 0.95, and its melting point is 70 ° C.

<Example 3>

The mixture was prepared in the same manner as in Example 1, except that 200 g of an ethylene-methacrylate copolymer (EMA) produced by reacting an ethylene monomer and a methacrylate monomer at a weight ratio of 9: 1 was used. , Not very low density polyethylene (VLDPE). In this case, the density of the ethylene-methacrylate copolymer (EMA) was 0.94, and its melting point was 72 ° C.

<Example 4>

The mixture was prepared in the same manner as in Example 1, except that 200 g of an ethylene-vinyl acetate copolymer (EVA) produced by reacting an ethylene monomer and a vinyl acetate monomer at a weight ratio of 9: 1 was used, and Non-Very Low Density Polyethylene (VLDPE). In this case, the density of the ethylene-vinyl acetate copolymer (EVA) was 0.95, and its melting point was 75 ° C.

<Example 5>

The mixture was prepared in the same manner as in Example 1, except that 200 g of an ethylene-butene copolymer was used instead of very low density polyethylene (VLDPE). In this case, the density of the ethylene-butene copolymer was 0.88, and its melting point was 64 ° C.

<Example 6>

300 g of ethylene-propylene diene monomer (EPDM) rubber and 300 g of very low density polyethylene (VLDPE) were mixed with 700 g of butadiene rubber (BR), and the hardener (30 g 4 was kneaded in a kneader and roller mill) , 4-di-third-butylperoxy-n-butylvalerate), inorganic filler (300 g of silicon dioxide, 50 g of titanium oxide) and wax (80 g of polyethylene, 20 g of slip aid). In this case, the density of the very low density polyethylene (VLDPE) is 0.87, and its melting point is 59 ° C.

<Example 7>

300 g of ethylene-propylene diene monomer (EPDM) rubber and 100 g of very low density polyethylene (VLDPE) were mixed with 700 g of butadiene rubber (BR), and the hardener (30 g 4 was kneaded in a kneader and roller mill) , 4-di-tert-butylperoxy-n-butylvalerate), inorganic filler (300 g of silicon dioxide, 50 g of titanium oxide) and wax (80 g of polyethylene, 20 g of slip aid). In this case, the density of the very low density polyethylene (VLDPE) is 0.885, and its melting point is 80 ° C.

[Comparative Example 1]

The mixture was prepared in the same manner as in Example 1 except that very low density polyethylene (VLDPE) was not used.

[Comparative Example 2]

The mixture was prepared in the same manner as in Example 1 except that low density polyethylene (LDPE) was used instead of very low density polyethylene (VLDPE). In this case, the density of the low density polyethylene (LDPE) is 0.921, and its melting point is 110 ° C.

[Comparative Example 3]

The mixture was prepared in the same manner as in Example 1, except that an ethylene-methacrylate copolymer having a density of 0.93 and a melting point of 110 ° C was used as a polymer additive instead of a very low density polyethylene (VLDPE).

[Comparative Example 4]

The mixture was prepared in the same manner as in Example 6 except that 400 g of very low density polyethylene (VLDPE) was used.

[Comparative Example 5]

The mixture was prepared in the same manner as in Example 6, except that 20 g of very low density polyethylene (VLDPE) was used.

<Example 8>

300 g of ethylene-propylene diene monomer (EPDM) rubber and 200 g of very low density polyethylene (VLDPE) were mixed with 700 g of butadiene rubber (BR), and the hardener (30 g 4 was kneaded in a kneader and roller mill) , 4-Di-tert-butylperoxy-n-butylvalerate), inorganic filler (300g silica, 50g oxidation Titanium) and a mixed detergent (30 g of monoethanolamine (MEA), 25 g of N-methylpyrrolidone (NMP), 35 g of dimethylsulfinium (DMSO)). In this case, the density of the very low density polyethylene (VLDPE) is 0.87, and its melting point is 60 ° C.

<Example 9>

The mixture was prepared in the same manner as in Example 8, except that 200 g of an ethylene-methacrylate copolymer (EMAA) ionic polymer produced by reacting ethylene monomer and acrylic monomer at a weight ratio of 9: 1 was used , Not very low density polyethylene (VLDPE). In this case, the density of the ethylene-methacrylate copolymer (EMAA) ionic polymer is 0.95, and its melting point is 70 ° C.

<Example 10>

A mixture was prepared in the same manner as in Example 8 except that 200 g of an ethylene-methacrylate copolymer (EMA) produced by reacting an ethylene monomer and a methacrylate monomer at a ratio of 9: 1 was used. , Not very low density polyethylene (VLDPE). In this case, the density of the ethylene-methacrylate copolymer (EMA) was 0.94, and its melting point was 72 ° C.

<Example 11>

The mixture was prepared in the same manner as in Example 8, except that 200 g of an ethylene-vinyl acetate copolymer (EVA) produced by reacting an ethylene monomer and a vinyl acetate monomer at a weight ratio of 9: 1 was used, and Non-Very Low Density Polyethylene (VLDPE). In this case, the density of the ethylene-vinyl acetate copolymer (EVA) was 0.95, and its melting point was 75 ° C.

<Example 12>

The mixture was prepared in the same manner as in Example 8 except that 200 g of an ethylene-butene copolymer was used instead of very low density polyethylene (VLDPE). In this case, the density of the ethylene-butene copolymer was 0.88, and its melting point was 64 ° C.

<Example 13>

300 g of ethylene-propylene diene monomer (EPDM) rubber and 300 g of very low density polyethylene (VLDPE) were mixed with 700 g of butadiene rubber (BR), and the hardener (30 g 4 was kneaded in a kneader and roller mill) , 4-di-tert-butylperoxy-n-butylvalerate), inorganic filler (300 g of silicon dioxide, 50 g of titanium oxide) and mixed detergent (30 g of monoethanolamine (MEA), 25 g of N-methylpyrrole Pyridone (NMP), 35 g dimethylsulfinium (DMSO)). In this case, the density of the very low density polyethylene (VLDPE) is 0.87, and its melting point is 59 ° C.

<Example 14>

300 g of ethylene-propylene diene monomer (EPDM) rubber and 100 g of very low density polyethylene (VLDPE) were mixed with 700 g of butadiene rubber (BR), and the hardener (30 g 4 was kneaded in a kneader and roller mill) , 4-di-tert-butylperoxy-n-butylvalerate), inorganic filler (300 g of silicon dioxide, 50 g of titanium oxide) and mixed detergent (30 g of monoethanolamine (MEA), 25 g of N-methylpyrrole Pyridone (NMP), 35 g dimethylsulfinium (DMSO)). In this case, the density of the very low density polyethylene (VLDPE) is 0.885, and its melting point is 80 ° C.

<Example 15>

The mixture was prepared in the same manner as in Example 8 except that the auxiliary cleaning agent (10 g Triton RW) was added by spraying on the inorganic filler and penetrating the other.

<Example 16>

The mixture was prepared in the same manner as in Example 15 except that 10 g of Triton XL-80N was used as an auxiliary cleaner.

<Example 17>

The mixture was prepared in the same manner as in Example 15 except that 10 g of Triton X-100 was used as the auxiliary cleaner.

<Example 18>

In order to confirm the effect of the expansion agent, 25 g of a 1: 1 mixture of water and ethanol was added to the composition of Example 15, and the mixture was prepared in the same manner as in Example 15.

<Example 19>

To confirm the effect of the cleaning catalyst, 5 g of KOH was added to the composition of Example 18 as a cleaning catalyst, and a mixture was prepared in the same manner as in Example 15.

[Comparative Example 6]

The mixture was prepared in the same manner as in Example 8 except that very low density polyethylene (VLDPE) was not used.

[Comparative Example 7]

The mixture was prepared in the same manner as in Example 8 except that low density polyethylene (LDPE) was used instead of very low density polyethylene (VLDPE). In this case, the density of the low density polyethylene (LDPE) is 0.921, and its melting point is 110 ° C.

[Comparative Example 8]

The mixture was prepared in the same manner as in Example 8, except that It is to use an ethylene-methacrylate copolymer with a density of 0.93 and a melting point of 110 ° C as a polymer additive instead of very low density polyethylene (VLDPE).

[Comparative Example 9]

The mixture was prepared in the same manner as in Example 13, except that 400 g of very low density polyethylene (VLDPE) was used.

[Comparative Example 10]

The mixture was prepared in the same manner as in Example 13, except that 20 g of very low density polyethylene (VLDPE) was used.

<Experimental Example 1>

Each of the mixtures prepared in Examples 1 to 7 and Comparative Examples 1 to 5 was placed in an experimental mold (MQFP 28 x 28), and cured at 180 ° C under a pressure of 60 kg / cm ² for 450 seconds to perform a mold release operation 30 times. .

In the disengagement operation, the frequency at which incomplete filling occurs is measured. The results are summarized in Table 1 below.

<Experimental Example 2>

Each of the mixtures prepared in Examples 1 to 7 and Comparative Examples 1 to 5 was placed in an experimental mold (MQFP 28 x 28), and cured at 180 ° C under a pressure of 60 kg / cm ² for 450 seconds to perform a mold release operation 30 times .

During the disengagement operation, measure the frequency of disengagement. The results are summarized in Table 2 below.

With reference to Tables 1 and 2, from the results of Comparative Examples 2 and 3, it can be confirmed that when an additive having a melting point greater than 100 ° C is used, the rubber used cannot be separated.

In addition, in the cases of Examples 1 to 7, it was confirmed that compared with Comparative Example 1 without using a polymer additive, the filling property and the mold release property were significantly increased.

In addition, it was confirmed that Comparative Example 4, which did not satisfy the content range of the present invention, was difficult to produce a product due to lack of release properties. In addition, in the case of Comparative Example 5, it was confirmed that the filling and demolding properties were slightly improved as compared with Comparative Example 1, but compared with Examples 1 to 7, the filling and demolding properties were significantly reduced.

<Experimental Example 3>

Each of the mixtures prepared in Examples 8 to 14 and Comparative Examples 6 to 10 was placed in an experimental mold (MQFP 28 x 28) contaminated with an epoxy molding compound (EMC) at 180 kg at 60 kg / cm ² It was hardened under pressure for 450 seconds to perform a mold cleaning operation.

In cleaning operations, the frequency at which incomplete filling occurs is measured. The results are summarized in Table 3 below.

<Experimental Example 4>

Each of the mixtures prepared in Examples 8 to 19 and Comparative Examples 6 to 10 was placed in an experimental mold (MQFP 28 x 28) contaminated with an epoxy molding compound (EMC) at 180 kg at 60 kg / cm ² Hardened under pressure for 450 seconds for mold cleaning. This operation is repeated until the contaminants are completely removed from the mold.

The degree of odor and smoke generated during the cleaning operation confirms the mold cleaning power against contaminants. The results are summarized in Table 4 below. The following results were obtained by performing the method five times and averaging the results.

Referring to Table 3, it can be confirmed from the experimental results of Comparative Examples 7 and 8 that when an additive having a melting point higher than 100 ° C is used, a rubber for cleaning cannot be produced.

In addition, in the cases of Examples 8 to 14, it was confirmed that the filling properties and cleaning power were significantly increased as compared with Comparative Example 6 without using a polymer additive.

In addition, it can be confirmed that in the case where Comparative Example 9 does not satisfy the content range of the present invention, the cleaning power is insufficient, and therefore it is difficult to use it as a cleaning rubber. Although the filling properties and cleaning power were slightly improved, compared with Examples 8 to 14, the filling properties and cleaning power were greatly reduced.

In addition, it was confirmed that when the cleaning supplement was used as in Examples 15 to 19, no odor and smoke generated during the cleaning operation were generated, and when using a rubber composition including an expansion agent or a cleaning catalyst as in Examples 18 and 19 In comparison with Example 15 which does not include an expansion agent or a cleaning catalyst, it exhibits much better cleaning power.

Although the preferred embodiments of the present invention have been disclosed for illustration, those skilled in the art may know that various modifications, various modifications and substitutions can be made without departing from the scope and spirit of the present invention disclosed by the drawings.

[Industrial applicability]

As described above, the rubber composition of the present invention improves the mobility of the rubber composition in a mold by combining specific components. As a result, the filling properties are improved, thereby solving the problem of incomplete filling phenomenon with conventional techniques. In addition, because the rubber used for detachment exhibits excellent mold release properties, the mold release properties are improved, and the cleaning power can be further improved by increasing the speed at which the cleaning agent releases from the crosslinked rubber.

Claims (17)

A rubber composition for improving the release property of a mold used for molding, the rubber composition comprising: 60 to 100 parts by weight of a butadiene rubber (BR), and 0 to 40 parts by weight of an ethylene-propylene diene monomer (EPDM) rubber and 5 to 40 parts by weight of an uncrosslinked rubber having a polymer additive having a melting point (T _m ) of 100 ° C. or lower; and 5 based on 100 parts by weight of the uncrosslinked rubber To 60 parts by weight of a wax, 0.5 to 10 parts by weight of a hardener, and 5 to 110 parts by weight of a mixture of an inorganic filler and an adsorbent. A rubber composition comprising: 60 to 100 parts by weight of a butadiene rubber (BR), 0 to 40 parts by weight of an ethylene-propylene diene monomer (EPDM) rubber, and 5 to 40 parts by weight An uncrosslinked rubber having a polymer additive having a melting point (Tm) of 100 ° C. or lower; and a cleaning agent of 5 to 60 parts by weight, 0.5 to 10 parts by weight based on 100 parts by weight of the uncrosslinked rubber A hardener and a mixture of 5 to 110 parts by weight of an inorganic filler and an adsorbent. For example, the rubber composition of claim 1 or 2, wherein the uncrosslinked rubber contains 10 to 30 parts by weight of a polymer additive. For example, the rubber composition of item 1 or 2 of the patent application scope, wherein the melting point of the polymer additive is 90 ° C or lower. For example, the rubber composition of item 1 or 2 of the patent application scope, wherein the polymer additive is a polyolefin-based elastomer, or a copolymer composed of a polyolefin monomer and an acrylic monomer, and an ionic polymer thereof, or Copolymer composed of polyolefin monomer and acrylate monomer. For example, the rubber composition of claim 5 in which the polyolefin-based elastomer is one or more selected from the group consisting of: very low density polyethylene (VLDPE); polybutene ; Poly-4-methyl-1-pentene (TPX); copolymers of propylene, butene, hexene, and / or octene and ethylene; and thermoplastic elastomers based on olefins. For example, the rubber composition of claim 5 in which the copolymer is one or more selected from the group consisting of ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid ester copolymer ( EMAA), ionic polymer of ethylene-methacrylate copolymer, ethylene-methacrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-alkyl acrylate-acrylic acid copolymer, ethylene -Alkyl methacrylate-methacrylate copolymer, ethylene-butyl acrylate copolymer (EBA), and ethylene-vinyl acetate copolymer (EVA). For example, the rubber composition of claim 5 in the patent application, wherein the copolymer is based on 100% by weight of the copolymer based on 60 to 96% by weight of a monomer for polyolefin and 4 to 40% by weight Acrylic acid or acrylate-based or vinyl acetate-based monomers are reacted. For example, the rubber composition according to item 1 or 2 of the patent application scope, wherein the polymer additive is an ethylene-propylene copolymer or an ethylene-butene copolymer. For example, the rubber composition according to item 1 of the application, wherein the wax is a mixture of polyethylene and a slip aid having a weight average molecular weight of 200 to 3000. For example, the rubber composition of claim 2 in the patent application range, wherein the cleaning agent is a mixture of different types of cleaning compounds. For example, the rubber composition of claim 2 in the patent application scope, wherein the rubber composition further comprises a cleaning supplement. For example, the rubber composition of claim 2 in the patent application scope, wherein the rubber composition further comprises an expansion agent. For example, the rubber composition of claim 2 of the patent application scope, wherein the rubber composition further comprises a strong acid or alkali cleaning catalyst. For example, the rubber composition of item 1 or 2 of the patent application scope, wherein the hardener is an organic peroxide. For example, the rubber composition of claim 1 or 2, wherein the inorganic filler is any one or a mixture of two or more selected from the group consisting of: silicon dioxide, talc, alumina , Potassium carbonate, calcium carbonate, aluminum hydroxide, titanium oxide and carbon black. A rubber sheet for demolding, the rubber sheet is made of a rubber composition such as item 1 or 2 of the scope of patent application.