Curable composition, injection molding mold, and injection molding method of thermosetting composition

Abstract

A curable composition comprising (A) a phosphoric acid group-containing (meth)acrylate compound, (B) a trifunctional or higher-functional (meth)acrylate compound, and at least one selected from (C) a urethane (meth)acrylate compound and (D) a polyester (meth)acrylate compound, wherein the content of the component (B) is 30 to 70 parts by mass relative to 100 parts by mass of the total components containing a (meth)acryloyl group.

Description

Technical Field

[0001] The present invention relates to a curable composition, an injection molding mold, and a method for injection molding a thermosetting composition. Background Art

[0002] In recent years, light-emitting devices using optical semiconductors such as light-emitting diodes (LEDs), which are gaining popularity, are generally manufactured as follows: a synthetic resin serving as a reflective material (reflector) is integrally formed with a concave lead frame, an optical semiconductor (LED) is fixed to the resulting molded body of the lead frame, and the device is sealed with a sealing material such as epoxy resin or silicone resin.

[0003] As a material for a reflective material, Patent Document 1 discloses a composition comprising a thermosetting resin such as an acrylate resin and a white pigment such as titanium oxide. Patent Document 1 claims that this composition can produce a cured product having excellent heat resistance and weather resistance and excellent adhesion to surrounding components.

[0004] Patent Document 2 describes the use of a thermosetting composition containing a (meth)acrylate compound and having a predetermined shear viscosity as a reflective material (light reflector) for an optical semiconductor for the purpose of suppressing the generation of burrs when forming a light reflector.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2012 / 056972

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2016-8230 Summary of the Invention

[0009] Reflective material is typically injected into a mold, then heated at a predetermined temperature for thermal curing, to form the reflective material. This process can sometimes produce flash during thermal curing within the mold. This flash can lead to reduced efficiency and poor product appearance due to the need for flash removal.

[0010] An object of the present invention is to provide a technique for suppressing the generation of flash during injection molding of a thermosetting composition.

[0011] The present inventors have discovered that flash of a molded body is easily generated by a gap between the molded body and the mold when the mold is pressed. Furthermore, they have discovered that forming a resin coating on the surface of the mold facing the molded body has the effect of suppressing flash.

[0012] Based on the above findings, the inventors conducted intensive studies and found that a coating obtained by curing a predetermined curable composition has an effect of suppressing burrs and is excellent in durability, thereby completing the present invention.

[0013] According to the present invention, the following curable compositions and the like are provided.

[0014] 1. A curable composition comprising: (A) a phosphoric acid group-containing (meth)acrylate compound; (B) a trifunctional or higher-functional (meth)acrylate compound; and (C) at least one selected from a urethane (meth)acrylate compound and (D) a polyester (meth)acrylate compound.

[0015] Content of the said (B) component is 30-70 mass parts with respect to 100 mass parts of total components containing a (meth)acryloyl group.

[0016] 2. The curable composition according to 1, wherein the component (B) has a molecular weight of less than 800.

[0017] 3. The curable composition according to 1 or 2, further comprising (E) a polymerization initiator.

[0018] 4. The curable composition according to any one of 1 to 3, comprising, as (F) a (meth)acrylate compound other than the components (A) to (D), a (meth)acrylate compound having a viscosity of 100 mPa·s or less at 25°C.

[0019] 5. A mold for injection molding, comprising a cured film of the curable composition according to any one of 1 to 4 on at least a portion of a surface facing a molded object.

[0020] 6. A method for injection molding a thermosetting composition, comprising using the injection molding die according to 5.

[0021] The present invention provides a technique for suppressing the formation of flash during injection molding of thermosetting compositions. Specifically, it provides a curable composition that can produce a cured film with excellent adhesion to the mold and suppresses the formation of flash. Furthermore, it provides an injection molding mold that suppresses the formation of flash in molded articles, and an injection molding method using a thermosetting composition using the injection molding mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic cross-sectional view showing an injection molding die according to one embodiment of the present invention. DETAILED DESCRIPTION

[0023] In this specification, "x to y" is used to represent a numerical range of "greater than x and less than y." Regarding a technical matter, if there are multiple lower limits such as "greater than x" or multiple upper limits such as "less than y," any combination of these upper and lower limits can be selected.

[0024] [Curable composition]

[0025] A curable composition according to one embodiment of the present invention comprises (A) a phosphate group-containing (meth)acrylate compound, (B) a trifunctional or higher-functional (meth)acrylate compound, and one or more selected from (C) a urethane (meth)acrylate compound and (D) a polyester (meth)acrylate compound. The composition is characterized in that the content of component (B) is 30 to 70 parts by mass (%) relative to a total of 100 parts by mass (%) of the components containing (meth)acryloyl groups.

[0026] In this specification, the "component containing a (meth)acryloyl group" refers to a compound containing one or more (meth)acryloyl groups in its molecular structure, and specifically refers to the above-mentioned components (A) to (D) and the component (F) described below.

[0027] In addition, (meth)acryloyl means acryloyl or methacryloyl. Similarly, (meth)acrylic acid means acrylic acid or methacrylic acid, and (meth)acrylate means acrylate or methacrylate.

[0028] The curable composition of the present embodiment is used, for example, to form a cured film coated on the surface of a mold used in the molding of a resin. By injection molding the thermosetting composition using a mold having a cured film formed thereon, the generation of flash can be suppressed. In addition, the mold has good adhesion to the cured film, and the cured film has high hardness, so it is not easy to cause damage.

[0029] Hereinafter, each component of the curable composition (hereinafter sometimes referred to as a composition) according to the present embodiment will be described.

[0030] <(A)Component>

[0031] Component (A) is a phosphoric acid group-containing (meth)acrylate compound. In the curable composition of this embodiment, by using component (A), peeling of the cured film from the mold surface and the associated generation of burrs on the molded article can be suppressed.

[0032] (A) As a component, the phosphoric acid group-containing (meth)acrylate which has at least one (meth)acryloyl group in 1 molecule is mentioned. For example, 2-acryloyloxyethyl acid phosphate (for example, "Light Acrylate P-1A(N)", manufactured by Kyoeisha Chemical Co., Ltd.), ethyl (meth)acrylate acid phosphate (for example, "Light Ester P-1M", manufactured by Kyoeisha Chemical Co., Ltd.), bis[(2-(meth)acryloyloxy)ethyl]phosphate (for example, "KAYAMER PM-2", manufactured by Nippon Kayaku Co., Ltd.), 2-(meth)acryloyloxyethylhexanoate acid phosphate (for example, "KAYAMER PM-21", manufactured by Nippon Kayaku Co., Ltd.), 2-hydroxyethyl (meth)acrylate acid phosphate (for example, "JPA-514", manufactured by Johoku Chemical Industry Co., Ltd.), 10-(meth)acryloyloxydecamethylene acid phosphate (for example, "MDP", manufactured by Kuraray Noritake Dental Co., Ltd.), etc. can be mentioned.

[0033] (A) Component may be used alone or in combination of two or more.

[0034] The content of the component (A) in the composition is, for example, 0.01 to 30 parts by mass, preferably 0.1 to 25 parts by mass, more preferably 0.2 to 20 parts by mass, and even more preferably 0.3 to 15 parts by mass, relative to 100 parts by mass of the total components containing a (meth)acryloyl group.

[0035] (A) As content of the component is within the above range, the adhesiveness between the obtained cured film and the mold tends to be sufficiently high.

[0036] If the content of the component (A) exceeds 30 parts by mass, there may be a problem with adhesion to the mold, but the releasability of the molded body obtained by mold molding from the mold may be reduced, which may adversely affect productivity.

[0037] <(B) Ingredient>

[0038] Component (B) is a trifunctional or higher polyfunctional (meth)acrylate compound. The composition of this embodiment contains component (B), which primarily increases the surface hardness of the resulting cured film and suppresses damage to the cured film. Therefore, by using a mold having this cured film, the generation of flash on the molded article due to damage to the cured film can be suppressed.

[0039] The component (B) is, for example, a compound having three or more (meth)acryloyl groups in one molecule. Specific examples include trifunctional compounds such as trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane triacrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethoxylated glycerol tri(meth)acrylate, propoxylated glycerol tri(meth)acrylate, and pentaerythritol tri(meth)acrylate; tetrafunctional compounds such as pentaerythritol tetra(meth)acrylate and trimethylolpropane tetra(meth)acrylate; and hexafunctional compounds such as dipentaerythritol hexa(meth)acrylate.

[0040] Among these, trifunctional compounds and tetrafunctional compounds are preferably used because they can easily provide a viscosity suitable for coating on a mold in the composition.

[0041] The component (B) may be used alone or in combination of two or more.

[0042] It should be noted that, in this specification, a compound having three or more (meth)acryloyl groups and a phosphate group in one molecule is not included in the "trifunctional or higher polyfunctional (meth)acrylate compound (B)" and is included in the above-mentioned "phosphate group-containing (meth)acrylate compound (A)".

[0043] The component (B) preferably has a molecular weight of less than 800, more preferably 200 to 700, from the viewpoint of obtaining a suitable surface hardness of the obtained cured film.

[0044] The content of component (B) in the composition is 30 to 70 parts by mass relative to a total of 100 parts by mass of the components containing a (meth)acryloyl group. By setting it within this range, the resulting cured film can obtain a moderately sufficient surface hardness, which can suppress the occurrence of damage. In addition, the adhesion to the mold is also improved.

[0045] The content of the component (B) is more preferably 35 to 65 parts by mass, further preferably 40 to 65 parts by mass.

[0046] <(C) Ingredient>

[0047] (C) component is a carbamate (meth) acrylate compound. By containing (C) component, the cured film obtained is mainly given appropriate strength. Therefore, by using a mold with this cured film, the generation of damage can be suppressed, and the generation of burrs can also be suppressed.

[0048] The component (C) can be obtained by esterifying a polyurethane oligomer obtained by reacting a polyether polyol and / or polyester polyol with a polyisocyanate with (meth)acrylic acid, for example.

[0049] As component (C), for example, commercially available Art Resin series products such as UN-333, UN-353, UN-350, UN-7600, UN-7700, UN-9000PEP, UN-9200A, UN-3320HC, and UN-904 (all manufactured by Negami Industries, Ltd.), U-2000PA, UA-290TM, and U-15HA (all manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) can be cited.

[0050] Among these, bifunctional urethane acrylates such as UN-7700 and UN-9000PEP are preferably used because the resulting cured films can have excellent strength.

[0051] (C) Component may be used alone or in combination of two or more.

[0052] It should be noted that, in this specification, a urethane (meth)acrylate compound having three or more (meth)acryloyl groups in one molecule is not included in the above-mentioned "trifunctional or higher polyfunctional (meth)acrylate compound (B)" and is included in the "urethane (meth)acrylate compound (C)".

[0053] In one embodiment, from the viewpoint of imparting strength to the obtained cured film, the weight average molecular weight of the component (C) is preferably 2,000 or more, more preferably 2,000 to 30,000.

[0054] In this specification, the weight average molecular weight is a value measured using a GPC (Gel Permeation Chromatography) method.

[0055] The content of the component (C) in the composition is, for example, 1 to 30 parts by mass, preferably 3 to 30 parts by mass, more preferably 5 to 30 parts by mass, and even more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the total components containing a (meth)acryloyl group.

[0056] <(D) Ingredient>

[0057] (D) component is polyester (meth) acrylate compound (D).By containing (D) component, mainly appropriate intensity is given to the obtained cured film.Therefore, by using the mold with this cured film, the generation of damage can be suppressed, and the generation of burrs can also be suppressed.

[0058] The component (D) can be obtained, for example, by esterifying the hydroxyl groups of a polyester oligomer having hydroxyl groups at both terminals obtained by condensation of a polycarboxylic acid and a polyol with (meth)acrylic acid, or by esterifying the hydroxyl groups at both terminals of an oligomer obtained by adding an alkylene oxide to a polycarboxylic acid with (meth)acrylic acid.

[0059] Examples of the component (D) include commercially available products such as CN2203, CN2270, CN2271, CN2272, CN2273, CN2274, and CN2283 (all manufactured by Arkema), and EBECRYL 810, EBECRYL 853, EBECRYL 884 and EBECRYL 885 (all manufactured by Daicel Allnex).

[0060] Among these, bifunctional polyester acrylates such as CN2270 and CN2283 are preferably used because the resulting cured films can have excellent strength.

[0061] (D) Component may be used alone or in combination of two or more.

[0062] It should be noted that, in this specification, a polyester (meth)acrylate compound having three or more (meth)acryloyl groups in one molecule is not included in the above-mentioned "trifunctional or higher polyfunctional (meth)acrylate compound (B)" but is included in the "polyester (meth)acrylate compound (D)".

[0063] The content of the component (D) in the composition is, for example, 1 to 30 parts by mass, preferably 3 to 30 parts by mass, more preferably 5 to 30 parts by mass, and even more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the total components containing a (meth)acryloyl group.

[0064] In the present embodiment, one or more components selected from the above-mentioned components (C) and (D) may be contained. From the viewpoint of obtaining good strength of the obtained cured film, both components (C) and (D) may be contained.

[0065] The total amount of the components (C) and (D) in the composition is, for example, 1 to 30 parts by mass, preferably 3 to 30 parts by mass, more preferably 5 to 30 parts by mass, and even more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

[0066] The mixing ratio (mass ratio) of the component (C) to the component (D) is not particularly limited, but is preferably component (C):component (D) = 20:80 to 80:20, and more preferably 30:70 to 70:30.

[0067] <(E) Ingredient>

[0068] The composition of one embodiment may contain a polymerization initiator as the component (E).

[0069] Examples of the polymerization initiator include thermal polymerization initiators and photopolymerization initiators.

[0070] The thermal polymerization initiator is not particularly limited, and examples thereof include ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, alkyl peroxyesters (peroxyesters), and peroxycarbonates.

[0071] Specific examples of ketone peroxides include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, acetylacetone peroxide, cyclohexanone peroxide, and methylcyclohexanone peroxide.

[0072] Specific examples of the hydroperoxides include 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, tert-butyl hydroperoxide, p-menthane hydroperoxide, and diisopropylbenzene hydroperoxide.

[0073] Specific examples of the diacyl peroxides include diisobutyryl peroxide, bis-3,5,5-trimethylhexanol peroxide, diperoxylauroyl peroxide, benzoyl peroxide, m-tolylbenzoyl peroxide, and succinic acid peroxide.

[0074] Specific examples of dialkyl peroxides include dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 1,3-bis(tert-butylperoxyisopropyl)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, di-tert-hexyl peroxide, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne.

[0075] Specific examples of peroxyketals include 1,1-di-tert-hexylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-tert-hexylperoxycyclohexane, 1,1-di-tert-butylperoxy-2-methylcyclohexane, 1,1-di-tert-butylperoxycyclohexane, 1,1-di(tert-amylperoxy)cyclohexane, 2,2-di(tert-butylperoxy)butane, and 4,4-di-tert-butylperoxybutyl valerate.

[0076] The above-mentioned thermal polymerization initiators may be used alone or in combination of two or more.

[0077] Specific examples of the alkyl peroxyesters (peroxyesters) include 1,1,3,3-tetramethylbutyl peroxyneodecanoate, α-cumyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-hexyl peroxyneodecanoate, tert-butyl peroxyneoheptanoate, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisobutyrate, di-tert-butyl peroxyhexahydroterephthalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisobutyrate, di-tert-butyl peroxyhexahydroterephthalate, 1,1,3,3-trimethylhexanoate, 1,3,3-tetramethylbutyl peroxide, tert-amyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxy-acetate, tert-butyl peroxybenzoate, dibutyl peroxytrimethyladipate, 2,5-dimethyl-2,5-di-2-ethylhexanoyl peroxyhexane, tert-hexyl peroxy-2-ethylhexanoate, tert-hexyl peroxyisopropyl monocarbonate, tert-butyl peroxylaurate, tert-butyl peroxyisopropyl monocarbonate, tert-butyl peroxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-dibenzoyl peroxyhexane, etc.

[0078] Specific examples of peroxycarbonates include di-n-propyl peroxydicarbonate, diisopropyl peroxycarbonate, di-4-tert-butylcyclohexyl peroxycarbonate, di-2-ethylhexyl peroxycarbonate, di-sec-butyl peroxycarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, diisopropyl peroxydicarbonate, tert-amyl peroxyisopropyl carbonate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxy-2-ethylhexyl carbonate, and 1,6-bis(tert-butylperoxycarboxyoxy)hexane.

[0079] Examples of the photopolymerization initiator include benzyl ketal-based photoradical polymerization initiators, α-hydroxyacetophenone-based photoradical polymerization initiators, benzoin-based photoradical polymerization initiators, and aminoacetophenone-based photoinitiators.

[0080] Examples of the benzyl ketal-based photoradical polymerization initiator include 2,2-dimethoxy-2-phenylacetophenone.

[0081] Examples of the α-hydroxyacetophenone-based photoradical polymerization initiator include 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexyl-phenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxymethylpropanone, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropane-1-one.

[0082] Examples of the benzoin-based photoradical polymerization initiator include benzoin, benzoin isobutyl ether, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether.

[0083] Examples of the aminoacetophenone-based photoradical polymerization initiator include 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one and 2-benzyl-2-(dimethylamino)-4′-morpholinophenylbutanone.

[0084] The above-mentioned photopolymerization initiators may be used alone or in combination of two or more.

[0085] The content of the component (E) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the total of the components containing a (meth)acryloyl group, from the viewpoint of polymerization reactivity.

[0086] <(F)Component>

[0087] In one embodiment, the composition may contain a (meth)acrylate compound other than components (A) to (D) as component (F), as long as the effects of the present invention are not impaired. Component (F) is primarily incorporated as a diluent to adjust the overall viscosity of the composition. By including component (F), the viscosity of the composition can be adjusted, for example, to make it suitable for use as a coating agent.

[0088] Examples of the component (F) include methyl (meth)acrylate, ethyl (meth)acrylate, lauryl (meth)acrylate, hydroxyethyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, glycidyl (meth)acrylate, ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, single-end (meth)acrylate-modified silicone oils, and dual-end (meth)acrylate-modified silicone oils.

[0089] The component (F) may be used alone or in combination of two or more.

[0090] In one embodiment, the viscosity of the component (F) at 25° C. is preferably 100 mPa·s or less, more preferably 1 to 50 mPa·s, from the viewpoint of obtaining a viscosity suitable for coating on a mold surface.

[0091] The content of the component (F) in the composition is 1 to 50 parts by mass, preferably 1 to 40 parts by mass, more preferably 3 to 30 parts by mass, and even more preferably 5 to 25 parts by mass, based on 100 parts by mass of the total of the components containing a (meth)acryloyl group.

[0092] <Additives>

[0093] The curable composition of the present embodiment may contain, in addition to the above-mentioned components (A) to (F), antioxidants, light stabilizers, ultraviolet absorbers, plasticizers, inorganic fillers, colorants, antistatic agents, lubricants, mold release agents, flame retardants, leveling agents, defoaming agents, etc. as additives. These additives can be known additives.

[0094] In one embodiment, 90% by mass or more, 95% by mass or more, 99% by mass or more, or substantially 100% by mass of the entire composition is components (A) to (F). Note that in the case of "substantially 100% by mass," unavoidable impurities may be included.

[0095] The composition of the present embodiment can be prepared by mixing the above-mentioned component (A), component (B), at least one selected from component (C) and component (D), component (E) and component (F) as optional components, and additives in a predetermined amount ratio. The mixing method is not particularly limited, and any known means such as a stirrer (mixer) can be used. In addition, mixing can be carried out at room temperature, under cooling, or under heating, under normal pressure, under reduced pressure, or under pressure.

[0096] The curable composition of this embodiment can be used to form a cured film formed on a mold used for molding a resin. For example, it is a material suitable for forming a cured film covering the surface of a mold used for injection molding.

[0097] The cured film obtained from the curable composition of this embodiment has excellent adhesion to the mold and excellent damage resistance, which can prevent the film from peeling from the mold and the occurrence of damage to the film surface. Therefore, by using a mold having this cured film to form a molded object such as a thermosetting composition, the formation of gaps between the molded object and the mold during pressing by the mold can be suppressed, and a good molded object without flash can be obtained.

[0098] [Injection molding mold]

[0099] An injection molding die according to one embodiment of the present invention includes a cured film obtained by curing the curable composition of the present invention on at least a portion of a surface facing a molded object.

[0100] Figure 1 This is a schematic cross-sectional view of an injection molding die according to one embodiment of the present invention.

[0101] The injection molding mold 10 includes a fixed mold 11 having a holding portion 111 for holding a molded object, and a movable mold 12 disposed opposite the fixed mold 11. The movable mold 12 includes a pressing portion 122 having an opposing surface 121 that opposes the molded object. The opposing surface 121 of the movable mold 12 is provided with a cured film 200 obtained by curing the curable composition of the present invention.

[0102] Next, a method for manufacturing the injection molding die according to this embodiment will be described.

[0103] First, a curable composition is applied to the facing surface 121 of the movable mold 12 to form a coating film.

[0104] The coating method is not particularly limited, and a known method can be used, such as spin coating, spray coating, flow coating, and dip coating.

[0105] Next, the coating film formed on the opposing surface 121 is cured by light or heat to form a cured film 200 .

[0106] The method for curing the coating film is not particularly limited, and for example, a curing method using ultraviolet irradiation or a heat curing method can be used, and both can be used in combination.

[0107] In the curing method based on ultraviolet irradiation, the amount of ultraviolet light irradiated is generally 50 to 50,000 mJ / cm 2 About 100 to 20000 mJ / cm 2 After the ultraviolet irradiation, a post-heat treatment may be performed, for example, preferably at 70 to 200° C. for 0.1 to 12 hours.

[0108] For heat curing methods, the curing temperature is generally about 50 to 200°C, preferably 100 to 180°C. Setting the temperature at 50°C or higher can suppress curing defects, while setting the temperature at 200°C or lower can suppress coloration. The curing time varies depending on the components contained in the composition, but is generally preferably 0.1 to 6 hours.

[0109] [Injection molding method of thermosetting composition]

[0110] In the method for injection molding a thermosetting composition according to one embodiment of the present invention, the thermosetting composition is molded using the injection molding die of the present invention described above.

[0111] The thermosetting composition used in this embodiment is not particularly limited, and for example, the thermosetting compositions described in Patent Documents 1 and 2 can be used. The injection molding apparatus and molding conditions are also not particularly limited, and for example, the apparatus and conditions described in Patent Document 2 can be used.

[0112] For example, in Figure 1 The injection molding mold 10 shown (hereinafter simply referred to as the mold 10) is used for injection molding. Although not shown in the figure, a filling part is connected to the mold 10, which fills the thermosetting composition as the raw material composition into the mold 10 by, for example, rotating a screw.

[0113] The thermosetting composition supplied to the filling portion from a raw material tank (not shown) is conveyed forward while being stirred and mixed by the rotation of the screw, and is injected into the mold 10 at high speed and high pressure.

[0114] The fixed mold 11 and the movable mold 12 of the mold 10 are heated to 30 to 250° C., preferably 50 to 200° C., and more preferably 80 to 180° C. by a heating device (not shown).

[0115] When the thermosetting composition is injected from the filling portion into the mold 10, the thermosetting composition (molded article) injected from the filling portion is held by the holding portion 111 of the fixed mold 11. From this state, the movable mold 12 and the fixed mold 11 are brought closer together to close the molds. With the cured film 200 of the movable mold 12 in contact with the thermosetting composition, the movable mold 12 is brought closer to the fixed mold 11, whereby the thermosetting composition is pressed by the pressing portion 122. The pressure applied to the thermosetting composition is not particularly limited, but is, for example, 0.1 to 30 MPa, more preferably 1 to 20 MPa.

[0116] Next, when the thermosetting composition is thermally cured to form a molded body, the movable mold 12 is separated from the fixed mold 11 , and the molded body held by the holding portion 111 of the fixed mold 11 is taken out.

[0117] The above-described method for injection molding a thermosetting composition according to this embodiment uses the injection molding mold of the present invention, thereby enabling the molded object to be pressed without creating a gap between the mold and the object. Consequently, a molded object with suppressed flash can be obtained.

[0118] Furthermore, the cured film of the mold of the present invention exhibits excellent adhesion to the mold and excellent damage resistance, thereby suppressing film peeling and damage to the film surface. Therefore, by using the mold having this cured film to press the molded object, damage to the molded object caused by damage to the cured film and damage to the molded object caused by excessive pressure from the mold can be suppressed, resulting in a molded object with suppressed flash.

[0119] Furthermore, the cured film of the mold of the present invention has excellent mold adhesion and damage resistance. Therefore, when the mold is pressed multiple times or when sandblasting is performed to remove stains on the surface of the cured film, the cured film is prevented from peeling off or from being damaged on the surface, thereby reducing the number of times the cured film needs to be replaced. Therefore, injection molding of thermosetting compositions can be performed efficiently.

[0120] The injection molding method of the present embodiment can be suitably used for injection molding of a thermosetting composition for a reflective material (reflector) of an optical semiconductor, for example.

[0121] In the above-described method for injection molding a thermosetting composition, the example in which the holder 111 of the fixed mold 11 holds only the thermosetting composition is described. However, the injection molding method of the present invention is not limited to this. For example, a lead frame may be placed on the holder 111 of the fixed mold 11, and a thermosetting composition for a reflector as a molded object may be injected thereon, so that the holder 111 holds both the lead frame and the thermosetting composition.

[0122] Example

[0123] The following examples of the present invention are given to further illustrate the present invention in detail, but the present invention is not limited to these examples.

[0124] Example 1

[0125] The components (A) to (F) shown in Table 1 were mixed and stirred at room temperature in the blending ratio shown in Table 1 to obtain a curable composition.

[0126] The resulting composition was applied to the surface of an injection molding mold facing the molded object using a bar coater to a film thickness of approximately 8 μm. The composition was then cured using a UV curing device (product name: PSCC-60048A, manufactured by CCS Corporation). The mold with the cured film was then placed in an oven at 150°C for 30 minutes, yielding a mold having a cured film on the surface facing the molded object.

[0127] Example 2 to Example 15

[0128] A mold having a cured film was obtained in the same manner as in Example 1 except that the components (A) to (F) were replaced with the components and mixing ratios shown in Table 1 or 2.

[0129] Example 16

[0130] A composition was obtained in the same manner as in Example 1 except that components (A) to (F) were replaced with the components and mixing ratios shown in Table 2. Subsequent operations were carried out in the same manner as in Example 1 except that UV curing was not performed to obtain a mold having a cured film.

[0131] Example 17

[0132] A composition was obtained in the same manner as in Example 1, except that components (A) to (F) were replaced with the components and mixing ratios shown in Table 2. Subsequent operations were carried out in the same manner as in Example 1, except that the standing in the oven was not performed, to obtain a mold having a cured film.

[0133] Comparative Examples 1 to 4

[0134] A mold having a cured film was obtained in the same manner as in Example 1 except that the components (A) to (F) were replaced with the components and mixing ratios shown in Table 2.

[0135] Comparative Example 5

[0136] The mold was evaluated without forming a cured film on the mold surface.

[0137] <Evaluation>

[0138] Injection molding was performed using the molds obtained in Examples 1 to 17 and Comparative Examples 1 to 5, and the generation of burrs, damage to the cured films, and peeling were evaluated.

[0139] The formulation of the thermosetting composition as the molded object is shown below.

[0140] Isobornyl methacrylate (Light Ester IB-X, manufactured by Kyoeisha Chemical Co., Ltd.): 8 parts by mass

[0141] Lauryl acrylate (SR355, manufactured by Arkema): 4 parts by mass

[0142] Glycidyl methacrylate (Blemmer GH, manufactured by NOF Corporation): 2 parts by mass

[0143] 1,10-Decanediol diacrylate (A-DOD-N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 6 parts by mass

[0144] Spherical silica (average particle size (D50) 15 μm, CRS1085-SF630, manufactured by Ronson Co., Ltd.): 65 parts by mass

[0145] Titanium oxide (average particle size 0.2 μm, PC-3, manufactured by Ishihara Sangyo Co., Ltd.): 10 parts by mass

[0146] Talc (average particle size 5 μm, TP-A25, manufactured by Fuji Talc Industries, Ltd.): 5 parts by mass

[0147] Ultraviolet absorber (Tinuvin 765, manufactured by BASF Japan Ltd.): 0.5 parts by mass

[0148] Zinc stearate (StZn, manufactured by Dainichi Chemical Industries, Ltd.): 1.5 parts by mass

[0149] Fumed silica (average particle size 5 to 50 nm, R711, manufactured by Nippon Aerosil Co., Ltd.): 3 parts by mass

[0150] Organic peroxide (Perhexa HC, manufactured by NOF Corporation): 1 part by mass

[0151] Using the molds obtained in Examples and Comparative Examples, the thermosetting compositions were injection-molded under the conditions shown below.

[0152] (Injection conditions)

[0153] Molding machine: Liquid thermosetting resin injection molding machine LA-40S, manufactured by Sodick Co., Ltd. Runner temperature in low-temperature section: 15°C

[0154] Flow channel and insulation method: Use a switch nozzle (Shut-off Nozzle)

[0155] High temperature section flow channel temperature and cavity temperature: 130°C

[0156] Filling time: 10 seconds

[0157] Filling pressure: 2MPa (filling time priority)

[0158] Holding time: 15 seconds

[0159] Holding pressure: 5MPa

[0160] Curing time: 90 seconds

[0161] Injection molding using each mold was performed 100 times or more under the above conditions. Evaluation criteria for each item are shown below.

[0162] (Flash of injection molded products)

[0163] The obtained injection molded products were visually inspected to check for the presence of burrs. A score of "0" was given for no burrs observed even after more than 100 injection molding cycles, and a score of "x" was given for burrs observed within 100 injection molding cycles.

[0164] (Peeling of Cured Film)

[0165] The state of the mold and the cured film was visually observed at each molding. A case where no peeling of the cured film was observed even after more than 100 cycles was rated as "0", and a case where peeling of the cured film occurred within 100 cycles was rated as "x".

[0166] (Damage to the cured film)

[0167] The state of the cured film on the mold was visually observed at each molding. A case where no damage to the cured film was observed even after more than 100 cycles was rated as "0", and a case where damage to the cured film occurred within 100 cycles was rated as "x".

[0168] The evaluation results are shown in Tables 1 and 2.

[0169] [Table 1]

[0170]

[0171] [Table 2]

[0172]

[0173] Components (A) to (F) shown in Tables 1 and 2 are as follows.

[0174] ((A) ingredient)

[0175] A-1: 2-Hydroxyethyl methacrylate acid phosphate (JPA-514, manufactured by Johoku Chemical Industry Co., Ltd.)

[0176] A-2: 2-Acryloyloxyethyl phosphate (Light Acrylate 1A(N), manufactured by Kyoeisha Chemical Co., Ltd.)

[0177] ((B) ingredient)

[0178] B-1: Trimethylolpropane triacrylate (SR351S, manufactured by Arkema)

[0179] B-2: Pentaerythritol tetraacrylate (SR295, manufactured by Arkema)

[0180] B-3: Ethoxylated (3) trimethylolpropane triacrylate (SR454, manufactured by Arkema)

[0181] B-4: Ethoxylated (6) trimethylolpropane triacrylate (SR499, manufactured by Arkema)

[0182] ((C) ingredient)

[0183] C-1: Urethane acrylate (Art Resin UN-9000PEP, manufactured by Negami Industries, Ltd.)

[0184] C-2: Urethane acrylate (Art Resin UN-7700, manufactured by Negami Industries, Ltd.)

[0185] C-3: Urethane acrylate (Art Resin UN-9200A, manufactured by Negami Industries, Ltd.)

[0186] ((D) ingredient)

[0187] D-1: Polyester acrylate (CN2283, manufactured by Arkema)

[0188] ((E) ingredient)

[0189] E-1: 1,1-di(tert-amylperoxy)cyclohexane (Luperox 531M80, manufactured by ARKEMA Yoshitomi Co., Ltd.)

[0190] E-2: 2-Hydroxy-2-methyl-1-phenylpropanone (Omnirad 1173, manufactured by IGM resins BV)

[0191] ((F) ingredient)

[0192] F-1: 1,10-Decanediol diacrylate (A-DOD-N, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity at 25°C: 10 mPa·s)

[0193] F-2: 1,6-Hexanediol diacrylate (SR238F, manufactured by Arkema, viscosity at 25°C: 9 mPa·s)

[0194] F-3: 1,9-nonanediol diacrylate (VISCOAT#260, manufactured by Osaka Organic Chemical Industry Co., Ltd., viscosity at 25°C: 8 mPa·s)

[0195] As shown in Tables 1 and 2, in Examples, even after more than 100 cycles, there was no damage to the cured film or film peeling, and the obtained injection molded articles all had no burrs and had good appearance.

[0196] On the other hand, the cured film of the mold of Comparative Example 1 did not contain the component (A), so the adhesion to the mold was insufficient, and the film peeled off within 100 cycles, resulting in burrs on the injection molded product.

[0197] In addition, the cured film of the mold of Comparative Example 2 had insufficient surface hardness due to the low content of component (B) at 25 parts by mass. This resulted in film damage within 100 cycles and flash on the injection molded product.

[0198] In addition, the cured film of the mold of Comparative Example 3 had an excessively high surface hardness of 72 parts by mass of component (B), resulting in insufficient adhesion to the mold. This resulted in damage and film peeling within 100 cycles, and flash on the injection molded product.

[0199] In addition, since neither the component (C) nor the component (D) was blended in the cured film of the mold of Comparative Example 4, the strength of the cured film was insufficient, and flash occurred in the injection molded product within 100 injection cycles.

[0200] Industrial applicability

[0201] The curable composition of the present invention is preferably used as a raw material for a cured film that covers the surface of a mold used for molding a resin, for example.

[0202] The injection molding die and injection molding method of the present invention can be suitably used for injection molding of a thermosetting composition for a reflective material (reflector) of an optical semiconductor, for example.

[0203] While several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will readily be able to make numerous modifications to these illustrative embodiments and / or examples without materially departing from the novel teachings and effects of the present invention. Therefore, these numerous modifications are intended to be within the scope of the present invention.

[0204] The entire contents of the Japanese application specification, which serves as the basis for the Paris priority claim of the present application, are incorporated herein by reference.

Claims

1. A mold for injection molding, wherein: A cured film of the curable composition is provided on at least a portion of the surface facing the molded object. The curable composition comprises: Component A is a (meth)acrylate compound containing a phosphoric acid group, Component B, a trifunctional or tetrafunctional polyfunctional (meth)acrylate compound having a molecular weight of less than 800, and One or more selected from the group consisting of a urethane (meth)acrylate compound (component C) and a polyester (meth)acrylate compound (component D), The content of the component B is 30 to 70 parts by mass relative to 100 parts by mass of the total components containing a (meth)acryloyl group. The component A does not include a compound having three or more (meth)acryloyl groups and a phosphate group in one molecule. The component C does not include a urethane (meth)acrylate compound having three or more (meth)acryloyl groups in one molecule. The component D does not include a polyester (meth)acrylate compound having three or more (meth)acryloyl groups in one molecule.

2. The injection molding die according to claim 1, wherein The component A is one or more selected from 2-acryloyloxyethyl acid phosphate, ethyl (meth)acrylate acid phosphate, bis[(2-(meth)acryloyloxy)ethyl]phosphate, 2-(meth)acryloyloxyethylhexanoate acid phosphate, 2-hydroxyethyl (meth)acrylate acid phosphate, and 10-(meth)acryloyloxydecamethylene acid phosphate.

3. The injection molding die according to claim 1 or 2, wherein: The content of the component A in the curable composition is 0.01 to 30 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

4. The injection molding die according to claim 1 or 2, wherein: The content of the component A in the curable composition is 0.3 to 15 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

5. The injection molding die according to claim 1 or 2, wherein: The component B is one or more selected from the group consisting of trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane triacrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethoxylated glycerol tri(meth)acrylate, propoxylated glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and trimethylolpropane tetra(meth)acrylate.

6. The injection molding die according to claim 1 or 2, wherein: The content of the component B in the curable composition is 40 to 65 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

7. The injection molding die according to claim 1 or 2, wherein: The component C is one or more bifunctional urethane acrylate compounds.

8. The injection molding die according to claim 1 or 2, wherein: The content of the component C in the curable composition is 1 to 30 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

9. The injection molding die according to claim 1 or 2, wherein: The content of the component C in the curable composition is 5 to 20 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

10. The injection molding die according to claim 1 or 2, wherein: The component D is one or more bifunctional polyester acrylate compounds.

11. The injection molding die according to claim 1 or 2, wherein: The content of the component D in the curable composition is 1 to 30 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

12. The injection molding die according to claim 1 or 2, wherein: The content of the component D in the curable composition is 5 to 20 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

13. The injection molding die according to claim 1 or 2, wherein: The molecular weight of the component B is 700 or less.

14. The injection molding die according to claim 1 or 2, wherein: The curable composition further includes a polymerization initiator as a component E.

15. The injection molding die according to claim 14, wherein The component E is one or more thermal polymerization initiators selected from the group consisting of ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, alkyl peroxyesters, and peroxycarbonates.

16. The injection molding die according to claim 14, wherein The component E is one or more peroxyketal thermal polymerization initiators selected from 1,1-di-tert-hexylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-tert-hexylperoxycyclohexane, 1,1-di-tert-butylperoxy-2-methylcyclohexane, 1,1-di-tert-butylperoxycyclohexane, 1,1-di-tert-amylperoxycyclohexane, 2,2-di-tert-butylperoxybutane and 4,4-di-tert-butylperoxybutyl valerate.

17. The injection molding die according to claim 14, wherein The component E is one or more photopolymerization initiators selected from the group consisting of benzyl ketal-based photoradical polymerization initiators, α-hydroxyacetophenone-based photoradical polymerization initiators, benzoin-based photoradical polymerization initiators, and aminoacetophenone-based photoinitiators.

18. The injection molding die according to claim 14, wherein The component E is one or more α-hydroxyacetophenone-based photoradical polymerization initiators selected from 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexyl-phenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxymethylpropanone, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropane-1-one.

19. The injection molding die according to claim 14, wherein The content of the component E is 0.01 to 10 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

20. The injection molding die according to claim 14, wherein The content of the component E is 0.1 to 5 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

21. The injection molding die according to claim 1 or 2, wherein: The curable composition further contains, as component F, a (meth)acrylate compound other than components A to D, a (meth)acrylate compound having a viscosity of 100 mPa·s or less at 25° C.

22. The injection molding die according to claim 21, wherein The component F is one or more selected from methyl (meth)acrylate, ethyl (meth)acrylate, lauryl (meth)acrylate, hydroxyethyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, glycidyl (meth)acrylate, ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, a single-end (meth)acrylate-modified silicone oil, and a double-end (meth)acrylate-modified silicone oil.

23. The injection molding die according to claim 21, wherein The viscosity of the component F at 25° C. is 1 mPa·s to 50 mPa·s.

24. The injection molding die according to claim 21, wherein The content of the component F is 1 to 50 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

25. The injection molding die according to claim 21, wherein The content of the component F is 5 to 25 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

26. The injection molding die according to claim 1 or 2, wherein: The curable composition contains both the component C and the component D.

27. The injection molding die according to claim 26, wherein The total amount of the component C and the component D in the curable composition is 1 to 30 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

28. The injection molding die according to claim 26, wherein The total amount of the component C and the component D in the curable composition is 5 to 30 parts by mass relative to 100 parts by mass of the total of the components containing a (meth)acryloyl group.

29. The injection molding die according to claim 26, wherein The mixing ratio of the component C to the component D is component C:component D=20:80 to 80:20 in terms of mass ratio.

30. The injection molding die according to claim 26, wherein The mixing ratio of the component C to the component D is component C:component D=30:70 to 70:30 in terms of mass ratio. 31 . A method for injection molding a thermosetting composition, comprising using the injection molding die according to claim 1 .

32. The injection molding method according to claim 31, wherein The pressure applied to the thermosetting composition is 0.1 MPa to 30 MPa.

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