JP2016102189A - Method for producing tablets - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing tablets free from attachment of a compound discolored yellow in view of the problem that, in molding of tablets containing a compound containing zinc oxide, yellow foreign matter sometimes contaminates the molded article, with the reason according to our research being that, when molding the tablets, the compound gets into a space between a pestle mold and a mortar mold, subjected to friction between a side of the pestle mold which slides and an inner side of the mortar mold, and a part of zinc oxide is discolored yellow and attaches to the tablet surface.SOLUTION: Provided are tablets obtained by pressing a compound, which is obtained by blending inorganic filler, silica and zinc oxide, into a thermosetting resin. Tablets having good appearance can be easily produced by a method for producing tablets comprising using a thermosetting resin which becomes a liquid or gets into a molten state at a molding temperature, and pressing the compound so that a compression ratio of the tablet becomes 95.0 to 97.0% or less.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a soft compound tablet.

A compound prepared by mixing a filler with a thermosetting resin that is liquid at room temperature is soft and sticky at room temperature. It is publicly known to form into a tablet shape for the purpose of improving the handleability when molding using a transfer molding machine or the like. A tableting method using a tableting machine is generally used as a method for tableting this compound. (Patent Document 1)
In general, a tableting machine is shaped into a tablet by pressing the compound while removing air contained in the compound from the gap between the die and the die.

Japanese Patent No. 5602923

    When molding using a tablet containing a compound containing zinc oxide, yellow foreign matter may be mixed into the molded product, and when the cause was examined in detail, a soft and sticky compound was The compound enters the gap between the mold and the die, the friction is applied between the side of the sliding die and the inner wall of the die, and a part of the zinc oxide turns yellow, and the tablet surface It was found that it was caused by adhering to.

  An object of the present invention is to develop a method for producing a tablet having no compound adhered to yellow.

As a result of intensive studies for solving the above problems, the present inventor has found a tablet manufacturing method capable of solving the above problems.
That is, the present invention has the following configuration.
1). A tablet formed by pressing a compound in which silica and zinc oxide, which are inorganic fillers, are mixed with a thermosetting resin,
A method for producing a tablet, which comprises using a thermosetting resin that is in a liquid or molten state at a kneading temperature and pressing the tablet so that the compression rate of the tablet is 95.0 to 97.0%.
2). 2. The method for producing a tablet according to claim 1, wherein the compound contains 5 to 60% by weight of a thermosetting resin, 35 to 90% by weight of zinc oxide, and 5 to 60% by weight of silica as essential components. .
3). It contains 5 to 60% by weight of thermosetting resin as essential components, 35 to 90% by weight of zinc oxide, 5 to 60% by weight of silica, and the tablet compression ratio is 95.0 to 97.0%. And tablet.

    According to the present invention, it is possible to obtain a tablet which is sticky and has no adhesion of a compound which has turned yellow even with a soft compound.

It is the schematic seen from the side of the tableting machine used for an Example and a comparative example. It is the schematic of the mortar mold and mortar mold of the tableting machine used for an Example and a comparative example.

  Hereinafter, an embodiment of a compound tableting method of the present invention will be described.

<Compound>
The compound in the present invention is
(A) component: curable resin (b) component: zinc oxide (c) component: a composition containing a filler as an essential component.

<(A) component>
The curable resin here means a thermosetting resin. Examples of the thermosetting resin of the present invention include non-colored resins such as transparent epoxy resins and silicon-based thermosetting resins, and modified resins thereof, but are limited to those described here as long as they are transparent. It is not something.

  The property of the curable resin used in the present invention is not limited to being a liquid resin at room temperature (23 ° C.). When the component (a) is kneaded, the curable resin is required to act as a binder with respect to the component (b) and the component (c). Even if the component (a) is in a solid state at room temperature or in a mixed state of a solid and a liquid at room temperature, it may be in a liquid or molten state at the kneading temperature. In addition, it is liquid at normal temperature (23 ° C.), and includes the case of kneading by heating.

  You may add the hardening accelerator for promoting the thermosetting reaction of this resin component, and the hardening retarder for delaying thermosetting reaction.

Examples of transparent epoxy resins include bisphenol A diglycidyl ether and 2,2 ′.
-Bis (4-glycidyloxycyclohexyl) propane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, vinylcyclohexene dioxide, 2- (3,4-epoxycyclohexyl) -5,5-spiro -(3,4-epoxycyclohexane) -1,3-dioxane, bis (3,4-epoxycyclohexyl) adipate, 1,2-cyclopropanedicarboxylic acid bisglycidyl ester, triglycidyl isocyanurate, monoallyl diglycidyl isocyanurate , Epoxy resins such as diallyl monoglycidyl isocyanurate with aliphatic acid anhydrides such as hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, hydrogenated methylnadic acid anhydride, etc. One which reduction and the like. These epoxy resins or curing agents may be used alone or in combination.

  Examples of the silicon-based thermosetting resin include a silicone resin, a modified silicone resin, an epoxy group-containing silicone resin, and a curable resin made of a cage silsesquioxane having a reactive functional group.

Among the above silicon-based thermosetting resins, (A) an organic compound containing at least two carbon-carbon double bonds reactive with SiH groups in one molecule, (B) at least two in one molecule Consists of a silicon compound comprising a silicon compound containing SiH groups, (C) a hydrosilylation catalyst, (D) an organic compound containing at least one carbon-carbon double bond reactive with SiH groups in one molecule. It is further preferable that
The components (A) to (D) will be described below.

<(A) component>
The component (A) is not particularly limited as long as it is an organic compound containing at least two carbon-carbon double bonds having reactivity with the SiH group in one molecule. The organic compound is preferably a compound other than a compound containing a siloxane unit (Si—O—Si), such as polysiloxane-organic block copolymer or polysiloxane-organic graft copolymer, and C, H, N, O as constituent elements. , Compounds containing no elements other than S and halogen are more preferred. In the case of a compound containing a siloxane unit, there are problems such as reactivity. The bonding position of the carbon-carbon double bond having reactivity with the SiH group is not particularly limited, and may be present anywhere in the molecule.

  (A) A component may be used independently and may be used in combination of 2 or more types.

The compound of the component (A) can be classified into an organic polymer compound and an organic monomer compound. Although it does not specifically limit as an organic polymer type compound, For example, polyether type, polyester type, polyarylate type, polycarbonate type, saturated hydrocarbon type, unsaturated hydrocarbon type, polyacrylate ester type, polyamide type, phenol-formaldehyde Examples thereof include a phenolic compound and a polyimide compound.
Although it does not specifically limit as an organic monomer type compound, For example, aromatic hydrocarbon type, such as phenol type, bisphenol type, benzene, and naphthalene; And the like.

Although it does not specifically limit as a carbon-carbon double bond which has the reactivity with SiH group of (A) component, following General formula (1)
CH ₂ = CR ^1- (1)
(In the formula, R ¹ represents a hydrogen atom or a methyl group.)
Is preferable from the viewpoint of reactivity. Among them, a group in which R ¹ is a hydrogen atom is particularly preferable because of easy availability of raw materials. Furthermore, as the carbon-carbon double bond having reactivity with the SiH group of the component (A), the following general formula (2)
-R ² C = CR ^2- (2)
(In the formula, R ² represents a hydrogen atom or a methyl group. Two R ² may be the same or different.) An alicyclic group having a partial structure in the ring is represented by From the point that the heat resistance of the cured product is high. Among them, a group in which R2 is a hydrogen atom is particularly preferable because of easy availability of raw materials.

The carbon-carbon double bond having reactivity with the SiH group may be directly bonded to the skeleton portion of the component (A) or may be covalently bonded through a divalent or higher valent substituent. Although the divalent or higher valent substituent is not particularly limited, a substituent having 0 to 10 carbon atoms is preferable, and a substituent that does not contain elements other than C, H, N, O, S, and halogen is more preferable as a constituent element. .
Examples of the group covalently bonded to the skeleton of the component (A) include a vinyl group, allyl group, methallyl group, acrylic group, methacryl group, 2-hydroxy-3- (allyloxy) propyl group, 2-allylphenyl group, 3-allylphenyl group, 4-allylphenyl group, 2- (allyloxy) phenyl group, 3- (allyloxy) phenyl group, 4- (allyloxy) phenyl group, 2- (allyloxy) ethyl group, 2,2-bis ( And allyloxymethyl) butyl group and 3-allyloxy-2,2-bis (allyloxymethyl) propyl group.

  As the organic compound of the component (A), low molecular weight compounds that are difficult to express by dividing into a skeleton portion and a group having a carbon-carbon double bond can also be used. Specific examples of the low molecular weight compounds include aliphatic chain polyene compound systems such as butadiene, isoprene, octadiene and decadiene, and aliphatic cyclic polyene compounds such as cyclopentadiene, cyclooctadiene, dicyclopentadiene, tricyclopentadiene and norbornadiene. And substituted aliphatic cyclic olefin compounds such as vinylcyclopentene and vinylcyclohexene.

  The component (A) preferably contains 0.001 mol or more of a carbon-carbon double bond having reactivity with the SiH group per 1 g of the component (A), from the viewpoint that heat resistance can be further improved. What contains 005 mol or more is more preferable, and what contains 0.008 mol or more is further more preferable.

  As specific examples of the component (A), in addition to the above, diallyl phthalate, triallyl trimellitate, diethylene glycol bisallyl carbonate, trimethylolpropane diallyl ether, pentaerythritol triallyl ether, 1,1,2,2- Tetraallyloxyethane, diarylidene pentaerythritol, triallyl cyanurate, triallyl isocyanurate, diallyl ether of 2,2-bis (4-hydroxycyclohexyl) propane, 1,2,4-trivinylcyclohexane, divinylbenzene (With a purity of 50 to 100%, preferably with a purity of 80 to 100%), divinylbiphenyl, 1,3-diisopropenylbenzene, 1,4-diisopropenylbenzene, oligomers thereof, 1,2- Polybutadiene (1 2 ratio of 10 to 100%, preferably 1,2 ratio of 50 to 100%), allyl ether of novolak phenol, allylated polyphenylene oxide, glycidyl group of epoxy resin was replaced with allyl group And the like.

  Among these, from the viewpoint of good optical properties such as light resistance, the aromatic ring component weight ratio in the component (A) is preferably 50% by weight or less, more preferably 40% by weight or less. 30% by weight or less is more preferable. Most preferred are those that do not contain an aromatic hydrocarbon ring.

  The number of carbon-carbon double bonds reactive with the SiH group of the component (A) may be at least two per molecule, but may exceed two from the viewpoint that heat resistance can be further improved. Preferably, the number is 3 or more, more preferably 4 or more. However, when the component (A) is a mixture of various compounds and the number of the carbon-carbon double bonds of each compound cannot be identified, the average of the carbon-carbon double bonds per molecule for the whole mixture The number is obtained and used as the number of the carbon-carbon double bonds of the component (A).

  When the number of carbon-carbon double bonds having reactivity with the SiH group of component (A) is 1 or less per molecule, only a graft structure is formed even if it reacts with component (B). Don't be.

  As the component (A), in order to obtain uniform mixing with other components and good workability, a component having fluidity at a temperature of 100 ° C. or lower is preferable. The component (A) may be linear or branched. Although there is no restriction | limiting in particular in the molecular weight of (A) component, The arbitrary things of 50-1000 can be used conveniently. The component (A) preferably has a molecular weight of less than 900, more preferably less than 700, and even more preferably less than 500.

As the component (A), from the viewpoint of availability and reactivity, bisphenol A diallyl ether,
2,2′-diallylbisphenol A, allyl ether of novolak phenol, diallyl phthalate, vinylcyclohexene, divinylbenzene, divinylbiphenyl, triallyl isocyanurate, diallyl ether of 2,2-bis (4-hydroxycyclohexyl) propane, 1, 2,4-trivinylcyclohexane is preferable, and triallyl isocyanurate is particularly preferable from the viewpoint of heat resistance and light resistance.

<(B) component>
The component (B) is not particularly limited as long as it is a compound containing at least two SiH groups in one molecule. For example, compounds described in International Publication No. WO96 / 15194 having at least two SiH groups in one molecule can be used. From the viewpoint of availability, a linear and / or cyclic organopolysiloxane having at least two SiH groups in one molecule is preferable. Among these, from the viewpoint of good compatibility with the component (A), the following general formula (3)

(In the formula, R ¹ represents an organic group having 1 to 6 carbon atoms, and n represents a number of 3 to 10).
A cyclic polyorganosiloxane having at least two SiH groups in one molecule is more preferred. Incidentally, the substituent R ¹ in the compound represented by the general formula (3) is, C, substituents preferably containing no elements other than H and O, a hydrocarbon group is more preferable.

  The component (B) was selected from a linear and / or cyclic polyorganosiloxane having at least two SiH groups in one molecule and an organic compound having a carbon-carbon double bond having reactivity with SiH groups. Also preferred are reactants with one or more compounds. In this case, in order to further enhance the compatibility of the reactant with the component (A), a product obtained by removing unreacted siloxanes from the reactant by devolatilization or the like can be used.

<(C) component>
Component (C) is a hydrosilylation catalyst.
The hydrosilylation catalyst is not particularly limited as long as it has a catalytic activity for the hydrosilylation reaction. For example, a platinum simple substance, a support made of alumina, silica, carbon black or the like on which solid platinum is supported, chloroplatinic acid, platinum chloride Complexes of acids with alcohols, aldehydes, ketones, etc., platinum-olefin complexes (eg Pt (CH ₂ ═CH ₂ ) ₂ (PPh ₃ ) ₂ , Pt (CH ₂ ═CH ₂ ) ₂ Cl ₂ ), platinum-vinyl Siloxane complexes (eg, Pt (ViMe ₂ SiOSiMe ₂ Vi) n, Pt [(MeViSiO) ₄ ] m), platinum-phosphine complexes (eg, Pt (PPh ₃ ) 4, Pt (PBu ₃ ) ₄ ), platinum-phos Fight complexes _{(e.g., Pt [P (OPh) 3} ] 4, Pt [P (OBu) 3] 4) ( in the formula, Me represents a methyl group, Bu a butyl group, Vi represents a vinyl group, P Represents a phenyl group, and n and m are integers.), Dicarbonyldichloroplatinum, Karstedt catalyst, and also described in Ashby US Pat. Nos. 3,159,601 and 3,159,662 And platinum-hydrocarbon complexes, as well as platinum alcoholate catalysts described in Lamoreaux US Pat. No. 3,220,972. In addition, platinum chloride-olefin complexes described in Modic US Pat. No. 3,516,946 are also useful in the present invention.

Examples of catalysts other than platinum compounds include RhCl (PPh) ₃ , RhCl ₃ , RhAl ₂ O ₃ , RuCl ₃ , IrCl ₃ , FeCl ₃ , AlCl ₃ , PdCl ₂ .2H ₂ O, NiCl ₂ , TiCl _4. , Etc.

  Of these, chloroplatinic acid, platinum-olefin complexes, platinum-vinylsiloxane complexes and the like are preferable from the viewpoint of catalytic activity. Moreover, these catalysts may be used independently and may be used together 2 or more types.

Although the addition amount of the catalyst is not particularly limited, the lower limit of the preferable addition amount is sufficient with respect to 1 mol of SiH groups of the component (B) in order to have sufficient curability and keep the cost of the curable resin composition relatively low. 10 ^-8 mol, more preferably 10 ^-6 mol, and the upper limit of the preferable addition amount is 10 ^-1 mol, more preferably 10 ^-2 mol, relative to 1 mol of SiH group of component (B). In addition, a cocatalyst can be used in combination with the above catalyst. Examples thereof include phosphorus compounds such as triphenylphosphine, 1,2-diester compounds such as dimethyl malate, 2-hydroxy-2-methyl-1 -Acetylene alcohol compounds such as butyne, sulfur compounds such as simple sulfur, amine compounds such as triethylamine, and the like. The addition amount of the cocatalyst is not particularly limited, but the lower limit of the preferable addition amount relative to 1 mol of the hydrosilylation catalyst is 10 ⁻² mol, more preferably 10 ⁻¹ mol, and the upper limit of the preferable addition amount is 10 ^2. Mol, more preferably 10 mol.

<(D) component>
The component (D) of the present invention is a silicone compound having a molecular weight of 1000 or more and containing at least one carbon-carbon double bond having reactivity with the SiH group in one molecule. By using a silicone compound composed of a siloxane skeleton consisting essentially of Si-O-Si bonds, a cured product having excellent heat resistance and light resistance can be obtained compared to the case of using a general organic polymer. be able to. Furthermore, by using the component (D) of the present invention, a curable resin composition that, when mixed with the inorganic filler of the component (E), gives a cured product excellent in toughness while having a smaller linear expansion coefficient. It can be. Further, it is possible to provide a molded product that hardly warps when molded on a substantially single side of a metal base material such as a lead frame including Cu.

  The silicone compound of component (D) is a compound whose skeleton is substantially formed of Si—O—Si bonds, and includes various compounds such as linear, cyclic, branched, and partial networks. Can be used.

  In this case, examples of the substituent bonded to the skeleton include alkyl groups such as methyl group, ethyl group, propyl group, and octyl group, aryl groups such as phenyl group, 2-phenylethyl group, and 2-phenylpropyl group, methoxy group, Examples thereof include alkoxy groups such as ethoxy group and isopropoxy group, and groups such as hydroxyl group. Among these, a methyl group, a phenyl group, a hydroxyl group, and a methoxy group are preferable, and a methyl group and a phenyl group are more preferable in that heat resistance tends to be high. Examples of the substituent having a carbon-carbon double bond reactive with the SiH group include a vinyl group, an allyl group, an acryloxy group, a methacryloxy group, an acryloxypropyl group, and a methacryloxypropyl group. Of these, a vinyl group is preferred in terms of good reactivity.

As an example of the component (D), it may be expressed by the following formula.
_{Rn (CH 2 = CH) m} SiO (4-n-m) / 2
(Wherein R is a group selected from a hydroxyl group, a methyl group or a phenyl group, and n and m are numbers satisfying 0 ≦ n <4, 0 <m ≦ 4, and 0 <n + m ≦ 4). These are the above silicone compounds.

Examples of component (D) include polydimethylsiloxane, polydiphenylsiloxane, polymethylphenylsiloxane, and two or three random or block copolymers having vinyl groups as terminal groups or side groups. be able to. As the component (D), a plurality of components may be mixed and used.

  Of these, linear polysiloxanes having vinyl groups at the ends are preferable, linear polysiloxanes having vinyl groups at both ends are more preferable, and both ends are more preferable in that the effects of the present invention are more easily obtained. More preferred are linear polydimethyl-polydiphenylsiloxane or linear polymethylphenylsiloxane having vinyl groups at the ends, and linear polydimethyl-polydiphenylsiloxane or linear polymethylphenylsiloxane having vinyl groups at both ends. And it is especially preferable that it is siloxane whose quantity of the phenyl group with respect to all the substituents is 10 mol% or more.

  As the molecular weight of component (D), the weight average molecular weight (Mw) is preferably 2,000 or more, more preferably 5,000 or more, and even more preferably 10,000 or more. When the molecular weight is high, the obtained cured product tends to have low stress. In addition, the molecular weight of the component (D) is preferably 1,000,000 or less, and more preferably 100,000 or less. When the molecular weight is large, it becomes difficult to obtain compatibility with the component (A) and the component (B).

  The amount of the component (D) is preferably 30% by weight or more, more preferably 50% by weight or more based on the total weight of the component (A) and the component (B). 80% by weight or more is more preferable.

  The mixing ratio of the component (A), the component (B), and the component (D) is not particularly limited as long as the required strength is not lost, but the component (A) having the number of SiH groups (Y) in the component (B). And the ratio of the number of carbon-carbon double bonds (X) having reactivity with SiH groups in component (D) is preferably Y / X ≧ 0.3, more preferably Y / X ≧ 0. 0.5, more preferably Y / X ≧ 0.7, and the upper limit of the preferred range is 3 ≧ Y / X, more preferably 2 ≧ Y / X, and even more preferably 1.5 ≧ Y / X. When it deviates from the preferred range, sufficient strength may not be obtained or thermal deterioration may easily occur.

<(B) component>
The average particle diameter of zinc oxide to which the present invention can be applied is 0.1 to 100 μm. When the particle size is less than this range, the particle size is too small, so that kneading becomes difficult. When the particle size is more than this range, the flow during compound kneading changes greatly, so that kneading becomes difficult.

Preferably it is 1-50 micrometers, More preferably, it is 2-25 micrometers. If it is this range, the function as a binder of the liquid resin component at the time of kneading | mixing will not be impaired, the flow of the zinc oxide at the time of kneading | mixing will become smooth, and it will become difficult to apply a local shear.
The shape of zinc oxide is not particularly limited.

<(C) component>
The component (c) has an effect of increasing the strength and hardness of the obtained cured product and reducing the linear expansion coefficient.

  Examples of the component (c) include silica, alumina, boron nitride, aluminum nitride, etc., excluding zinc oxide, but are not limited to those exemplified here. The shape is not particularly limited, but 50% or more of the filler is preferably spherical. When 50% or more of the filler is spherical, the liquid resin component as a binder is less likely to be absorbed in the filler particles and the fluidity is improved, so that uniform kneading is facilitated.

  The hardness is not particularly limited, but in the case of a filler harder than 4 which is the Mohs hardness of zinc oxide, 50% or more of the filler is preferably spherical, and more preferably 75% or more. preferable. When the spherical filler is 50% or less, there is a possibility that the zinc oxide is subjected to strong local shearing during kneading and the yellowing degree is increased. The average particle diameter of the filler to which the present invention can be applied is 0.1 to 100 μm. When the particle size is less than this range, the particle size is too small, so that kneading becomes difficult. When the particle size is more than this range, the flow during compound kneading changes greatly, so that kneading becomes difficult. Preferably it is 1-50 micrometers, More preferably, it is 2-25 micrometers. If it is this range, the function as a binder of the liquid resin component at the time of kneading | mixing will not be impaired, the flow of the zinc oxide at the time of kneading | mixing will become smooth, and it will become difficult to apply a local shear.

  In addition, the compound of the present invention contains the above-mentioned compound as a main component, and contains a solvent, a stabilizer, a plasticizer, a mold release agent, and other components as needed within a range that does not impair the object of the present invention. Can do.

<Mixing ratio of each component>
It describes about the ratio of each component with respect to a compound.
As the ratio of the component (a), the larger the amount of the liquid component, the easier the kneading, and further, the flow of the particles in the compound becomes more advantageous and the shearing to the zinc oxide is less likely to occur. Therefore, it may be 5% by weight or more, preferably 7% by weight or more, and more preferably 9% by weight or more with respect to the entire compound.
The ratio of the component (b) is preferably 35% by weight or more, more preferably 40% by weight or more based on the whole compound. In the case of the above range or less, the whiteness of the obtained cured product is not ensured.
The ratio of the component (c) is preferably 5% by weight or more, more preferably 15% by weight or more, and further preferably 25% by weight or more with respect to the whole compound. In the case of the above range or less, the strength of the obtained cured product is not ensured.
From the above contents, it is possible to blend 5 to 60% by weight of component (a), 35 to 90% by weight of component (b), and 5 to 60% by weight of component (c). It can be said that the composition is balanced in terms of fluidity, whiteness, and strength.

  Desirable formulation is 7 to 15% by weight of component (a), 40 to 77% by weight of component (b), and 15 to 53% by weight of component (c). More desirable formulation is 9 to 9% of component (a). 12 weight%, (b) component is 40 to 43 weight%, and (c) component is 45 to 48 weight%.

<Kneading equipment>
The kneading apparatus includes two pairs of rolls, and a compound in which the inorganic filler and the liquid material are uniformly kneaded can be produced by compressing and expanding the compound in which the inorganic filler and the liquid material are premixed.

  The material of the two pairs of rolls is not particularly limited, but the metal surface is higher than the Mohs hardness of the filler because the mold surface is worn by the inorganic filler contained in the compound and metal powder is mixed into the compound. It is desirable to use or to plate the mold surface.

  Since the zinc oxide contained in the compound turns yellow when friction is applied, in order to make the friction as low as possible, the two pairs of rolls are preferably a mechanism that rotates at a constant speed or a roll that rotates without permission.

  The clearance between the two pairs of rolls is preferably 1.0 mm to 3.0 mm. From the viewpoint of the degree of compound kneading, the clearance between the two pairs of rolls is more preferably 1.0 mm to 2.0 mm. From the viewpoint of yellow discoloration of the compound, the clearance between the two pairs of rolls is more preferably 1.5 mm to 2.0 mm.

<Tablet press>
FIG. 1 shows an example of an apparatus for forming a compound into a tablet. The tableting machine is placed at the top and bottom of the die that fills the compound, and the die that compresses the filled compound from above and presses the compound, and then removes the pressed compound (hereinafter referred to as tablet). It is an apparatus comprising a die for making a tablet, and the tablet can be manufactured by pressing the compound in a cylindrical shape.

  The mechanism for compressing the mold is not particularly limited, but a tableting machine equipped with an air cylinder or a hydraulic cylinder is desirable.

  The material of the mold is not particularly limited as long as it is a material that is not deformed or destroyed by tableting, but the metal surface is worn by the inorganic filler contained in the compound, and metal powder is mixed into the compound. It is desirable to use a metal having a material higher than the Mohs hardness of the filler or to plate the mold surface.

  The surface roughness of the mold surface is not particularly limited, but the surface roughness Rz of the plating mold is from 6.3 μm from the viewpoint of demoldability from the plating mold with the surface roughness of the obtained tablet. It is desirable that the thickness is 100 μm.

  The clearance between the inner surface of the mortar mold and the side surface of the plating mold is preferably 30 μm to 100 μm from the viewpoint of crimping the compound while removing the air contained in the compound. Considering that the compound leaks between the die and the die, it is more desirable that the clearance between the inner surface of the die and the side of the die is 30 μm to 50 μm.

  According to the present invention, it is possible to produce a tablet having no yellow color-changing compound.

Embodiments and effects of the present invention will be described below with reference to examples, but the present invention is not limited thereto.

<Compound used>
In the examples and comparative examples, the compounds shown in Table 1 were used.
(Synthesis Example 1)
A stirrer, a dropping funnel, and a condenser tube were set in a 5 L four-necked flask. Into this flask, 1800 g of toluene and 1440 g of 1,3,5,7-tetramethylcyclotetrasiloxane were placed, heated and stirred in an oil bath at 120 ° C. A mixed solution of 200 g of triallyl isocyanurate, 200 g of toluene and 1.44 ml of a xylene solution of platinum vinylsiloxane complex (containing 3 wt% as platinum) was added dropwise over 50 minutes. The obtained solution was heated and stirred as it was for 6 hours, and then unreacted 1,3,5,7-tetramethylcyclotetrasiloxane and toluene were distilled off under reduced pressure to obtain.

(Synthesis Example 2)
After putting 720 g of toluene and 240 g of 1,3,5,7-tetramethylcyclotetrasiloxane in a 2 L autoclave and replacing the gas phase part with nitrogen, the jacket temperature was set to 50 ° C. and heated and stirred. A mixed solution of 171 g of allyl glycidyl ether, 171 g of toluene and 0.049 g of a xylene solution of platinum vinylsiloxane complex (containing 3 wt% as platinum) was added dropwise over 90 minutes. After completion of dropping, the jacket temperature was raised to 60 ° C. for 40 minutes, and 1H-NMR confirmed that the allyl group reaction rate was 95% or more. After dropwise addition of 17 g of triallyl isocyanurate and 17 g of toluene, the jacket temperature was raised to 105 ° C., and xylene solution of triallyl isocyanurate 66 g, toluene 66 g and a platinum vinylsiloxane complex (containing 3 wt% as platinum) 033 g of the mixed solution was added dropwise over 30 minutes. Four hours after the completion of the dropwise addition, it was confirmed by 1H-NMR that the reaction rate of the allyl group was 95% or more, and the reaction was terminated by cooling. The unreacted rate of 1,3,5,7-tetramethylcyclotetrasiloxane was 0.8%. The total amount of unreacted 1,3,5,7-tetramethylcyclotetrasiloxane, toluene and allyl glycidyl ether by-products (inner transition products of allylic glycidyl ether vinyl group (cis- and trans-isomers)) is 5,000 ppm or less in total. The solution was distilled off under reduced pressure until a colorless and transparent liquid was obtained.

Example 1
The liquid components listed in Table 1 (A), (B), (C), (D), and curing retarder are weighed into a cup-shaped container and made uniform with a plastic spatula. Until mixed. A release agent and the component (c) were added little by little to the mixed solution, and mixed with a plastic spatula. Further, the component (b) was added little by little and mixed. A compound was obtained by passing the obtained clay-like mixture through a mixing roll (manufactured by Yasuda Seiki Seisakusho) with a roll clearance of 1.5 mm 20 times.

  Fill the compound weighed to about 5.0g into the die of the tabletting machine, and apply the compound in the tabletting machine where the tabletting pressure is set to 30kg / cm2 and the tabletting time is set to 2 seconds. Tableting was performed to obtain a cylindrical tablet (diameter 13 mm × height 16 mm). Tableting was continuously performed to obtain a total of 100 tablets.

(Example 2)
About 5.0 g of the same compound as in Example 1 was filled in the mold of the tableting machine, and the compound was tableted with a tableting machine in which the tableting pressure was set to 20 kg / cm 2 and the tableting time was set to 2 seconds. As a result, a cylindrical tablet was obtained. Tableting was continuously performed, and tableting was continuously performed to obtain a total of 100 tablets.

(Example 3)
About 5.0 g of the same compound as in Example 1 is filled in the mold of a tableting machine, and the compound is tableted with a tableting machine in which the tableting pressure is set to 15 kg / cm 2 and the tableting time is set to 2 seconds. As a result, a cylindrical tablet was obtained. Tableting was continuously performed, and tableting was continuously performed to obtain a total of 100 tablets.

(Comparative Example 1)
About 5.0 g of the same compound as in Example 1 is filled in the mold of the tableting machine, and the compound is tableted with a tableting machine in which the tableting pressure is set to 113 kg / cm 2 and the tableting time is set to 2 seconds. As a result, a cylindrical tablet was obtained. Tableting was continuously performed to obtain a total of 100 tablets.

(Comparative Example 2)
About 5.0 g of the same compound as in Example 1 is filled in the mold of the tableting machine, and the compound is tableted with a tableting machine in which the tableting pressure is set to 10 kg / cm 2 and the tableting time is set to 2 seconds. As a result, a cylindrical tablet was obtained. Tableting was continuously performed to obtain a total of 100 tablets.

  The measurement and evaluation of the examples were performed under the following conditions and methods. The evaluation results are shown in Table 2.

<Presence of yellowing compound adhesion>
The appearance of all the obtained tablets was visually observed, and the number of tablets to which the compound that had turned yellow in 100 adhered was counted.

<Tablet actual density>
Five samples were randomly extracted from the obtained tablets, and the actual density of the tablets was measured with an electronic hydrometer (manufactured by ALFA MIRAGE).

<True density of tablet>
The tablet obtained in the example was loaded into a transfer molding machine (Apic Yamada Co., Ltd.) heated to 165 ° C., and then the compound was injected into the mold at a pressure of 15 MPa to obtain a flat plate. The density of the obtained flat plate was measured with an electronic hydrometer (manufactured by ALFA MIRAGE), and the obtained value was defined as the true density of the tablet.

<Tablet compression rate>
The tablet compression ratio was calculated using the actual density of the tablet, the true density of the tablet, and the following formula.
Tablet compression ratio (%): 100 x (actual density of tablet / true density of tablet)
<Tablet breaking strength>
Five samples were randomly extracted from the obtained tablets, the maximum load value when the tablet was broken with a force gauge (manufactured by Imada Co., Ltd.) was measured, and the average value was calculated.
(Tablet breaking strength: breaking strength when a weight is applied from the upper and lower surfaces of a cylindrical tablet (diameter 13 mm x height 16 mm))

As shown in Table 2, the tablets obtained in Examples 1 to 3 had tablet compression ratios of 95.8% to 96.8%, whereas the tablets obtained in Comparative Example 1 had tablet compression ratios. Was 97.4%. The tablet obtained in Example 1 had no yellowed tablet, and the tablet obtained in Comparative Example was confirmed to have 4 out of 100 tablets to which the yellowed compound adhered.

  Further, in Example 1, the adhesion of the compound was not confirmed on the side surface of the plating mold, whereas in the comparative example 1, the adhesion of the compound was confirmed on the side surface of the plating mold.

DESCRIPTION OF SYMBOLS 1 ... Plating die arrange | positioned at the upper part 2 ... Die mold 3 ... Plating die arrange | positioned in the lower part 4 ... Gap between the side surface of the die mold and the inner wall of the die mold

Claims (3)

A tablet formed by pressing a compound in which silica and zinc oxide, which are inorganic fillers, are mixed with a thermosetting resin,
A method for producing a tablet, which comprises using a thermosetting resin that is in a liquid or molten state at a kneading temperature and pressing the tablet so that the compression rate of the tablet is 95.0 to 97.0%.   2. The method for producing a tablet according to claim 1, wherein the compound contains 5 to 60% by weight of a thermosetting resin, 35 to 90% by weight of zinc oxide, and 5 to 60% by weight of silica as essential components. .   It contains 5 to 60% by weight of thermosetting resin as essential components, 35 to 90% by weight of zinc oxide, 5 to 60% by weight of silica, and the tablet compression ratio is 95.0 to 97.0%. And tablet.

Images