JP6575508B2 - Photocurable composition - Google Patents

Description

  The present invention relates to a photocurable composition suitable for temporary fixing.

  Patent Document 1 describes a photocurable composition that is suitable for use in performing work processes such as cutting and polishing of wafers and the like. As the wafer or the like, a silicone wafer, sapphire glass, ceramic material, optical glass, crystal, magnetic material, or the like is assumed. In general, an acrylic composition has a high cure shrinkage rate, and when temporarily fixing a wafer or the like, it is assumed that the wafer or the like is distorted by cure shrinkage. On the other hand, in the invention of Patent Document 2, an attempt is made to lower the curing shrinkage rate by adding a plasticizer. If a larger amount of plasticizer is added in the ratio between the curable resin and the plasticizer, the curing shrinkage rate is lowered accordingly. However, since the molecular weight of the curable resin increases as it hardens, a bleedout phenomenon such as separation of the plasticizer and bleeding into the surface of the cured product is likely to occur. For this reason, there are limitations on the selection and addition amount of curable resin and plasticizer.

JP 2009-272557 A JP 2012-201786 A

  Conventionally, even when various acrylic resins are used, the plasticizer does not bleed out, and it has been difficult to lower the cure shrinkage and lower the viscosity.

  As a result of intensive studies to achieve the above object, the present inventors have completed an invention relating to a photocurable composition that exhibits a low curing shrinkage rate without bleeding out.

The gist of the present invention will be described next. 1st embodiment of this invention contains (A)-(D) component, (A) 100 mass parts of components contain (B) component and the sum total of (C) component contains 100 mass parts or more, ( B) A photocurable composition containing no curing agent and / or curing accelerator that reacts with the component.
(A) Component: Compound having an acrylic group (B) Component: Epoxy resin liquid at 25 ° C. (C) Component: (Meth) acrylic polymer (D) component liquid at 25 ° C .: Photoinitiator.

  The second embodiment of the present invention is the photocurable composition according to the first embodiment, wherein the component (A) contains a compound having two or more acrylic groups in the molecule.

  The third embodiment of the present invention is the photocurable composition according to any one of the first and second embodiments having a viscosity of 500 mPa · s or less and a cure shrinkage of 3.0 or less.

  The fourth embodiment of the present invention is a temporary fixing agent comprising the photocurable composition according to any one of the first to third embodiments.

  The photocurable composition of the present invention comprises (A) component: a compound having an acrylic group, (B) component: an epoxy resin that is liquid at 25 ° C., and (C) component: a (meth) acrylic polymer that is liquid at 25 ° C. And (D) component: a curing agent that contains a photoinitiator, contains 100 parts by mass or more of (B) component and (C) component with respect to 100 parts by mass of component (A), and reacts with component (B) And / or does not contain a curing accelerator. The component (A) preferably contains a compound having two or more acrylic groups in the molecule. The photocurable composition preferably has a viscosity of 500 mPa · s or less and a cure shrinkage of 3.0 or less. Furthermore, the temporary fixing agent of this invention is characterized by including the said photocurable composition. In the present invention having such a configuration, the plasticizer does not bleed out even when various acrylic resins are used, and the cure shrinkage rate is lowered and the viscosity can be lowered. Thus, it is a photocurable composition suitable for a temporary fixing agent.

  Details of the present invention will be described below.

<Photocurable composition>
(A) Component: Compound Having Acrylic Group The component (A) that can be used in the present invention is a compound having an acrylic group. There is no limitation as long as it is a compound having an acrylic group that is polymerized with an initiator that generates radical species or cationic species by being decomposed by energy rays such as ultraviolet rays or visible light or heat. Moreover, a monomer and an oligomer may be mixed and used, and a single type or a plurality of types may be mixed and used.

  Specific examples of monofunctional monomers (compounds having one acrylic group in the molecule) that can be used as component (A) include lauryl acrylate, stearyl acrylate, tetrahydrofurfuryl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, cyclohexyl acrylate, Dicyclopentanyl acrylate, isobornyl acrylate, benzyl acrylate, phenyl acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxytetraethylene glycol acrylate, nonylphenoxyethyl acrylate, nonylphenoxytetraethylene glycol acrylate, methoxydiethylene glycol acrylate, ethoxydiethylene glycol acrylate , Butoki Ethyl acrylate, butoxytriethylene glycol acrylate, 2-ethylhexyl polyethylene glycol acrylate, nonylphenyl polypropylene glycol acrylate, methoxydipropylene glycol acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycerol acrylate, polyethylene glycol acrylate, Polypropylene glycol acrylate, epichlorohydrin (hereinafter abbreviated as ECH) modified butyl acrylate, ECH modified phenoxy acrylate, ethylene oxide (hereinafter abbreviated as EO) modified phthalic acid acrylate, EO modified succinic acid acrylate, caprolactone modified 2-hydroxyethyl acrylate, N, N-dimethyl Amino ethyl acrylate, N, N-diethylaminoethyl acrylate, morpholinoethyl acrylate, but EO-modified phosphoric acid acrylate and the like, but is not limited thereto.

  Specific examples of the bifunctional monomer (compound having two acrylic groups in the molecule) include 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate, neopentyl glycol diacrylate, 1,6- Hexane glycol diacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, propylene glycol diacrylate, tripropylene glycol diacrylate, EO-modified neopentyl glycol diacrylate, propylene oxide side (hereinafter abbreviated as PO) modified neopentyl glycol Diacrylate, bisphenol A diacrylate, EO modified bisphenol A diacrylate, ECH modified bisphenol A diacrylate, EO modified bisphenol S Diacrylate Hydroxypivalate ester neopentyl glycol diacrylate, caprolactone modified hydroxypivalate ester neopentyl glycol diacrylate, neopentyl glycol modified trimethylolpropane diacrylate, stearic acid modified pentaerythritol diacrylate, dicyclopentenyl diacrylate, EO Examples thereof include, but are not limited to, modified dicyclopentenyl diacrylate and diacryloyl isocyanurate.

  Specific examples of the trifunctional monomer (compound having three acrylic groups in the molecule) include trimethylolpropane triacrylate, pentaerythritol triacrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, ECH Examples thereof include, but are not limited to, modified trimethylolpropane triacrylate, ECH-modified glycerol triacrylate, and tris (acryloyloxyethyl) isocyanurate.

  Specific examples of polyfunctional monomers (compounds having 4 or more acrylic groups in the molecule) include ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, di Examples include, but are not limited to, pentaerythritol hexaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, and the like.

  Specific examples of acrylate oligomers (compounds having a plurality of acrylic groups in the molecule) include epoxy-modified acrylate oligomers in which acrylic acid is added to glycidyl groups, polyols are polymerized with polyisocyanates and acrylic monomers having acrylic acid or hydroxyl groups. Urethane-modified acrylate oligomers, oligomers obtained by directly adding an acrylic group to polyether polyols or polyester polyols, and the main skeletons thereof include bisphenol A, novolac phenol, polybutadiene, polyester, polyether, etc. It is not limited. The component (A) that can be used in the present invention includes a compound having one or more epoxy groups and one or more acrylic groups in one molecule.

  Considering the compatibility with the component (A) and the component (B), the acrylate oligomer is preferably an oligomer having a polyester main skeleton.

  The component (A) preferably contains a compound having two or more acrylic groups in the molecule from the viewpoint of improving the curability of the cured product surface.

Component (B): Epoxy resin that is liquid at 25 ° C. Component (B) that can be used in the present invention is an epoxy resin that is liquid at 25 ° C. An epoxy resin refers to a compound having one or more glycidyl groups in the molecule. As the component (B), one type may be used, or a plurality of types may be mixed and used.

  Specific examples of the polyvalent epoxy resin include those obtained by condensation of epichlorohydrin with polyhydric phenols such as bisphenols and polyhydric alcohols, bisphenol A type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol. G type bisidyl ether type such as F type, bisphenol S type, bisphenol AF type, biphenyl type, naphthalene type, fluorene type, novolak type, phenol novolak type, orthocresol novolak type, tris (hydroxyphenyl) methane type, tetraphenylolethane type An epoxy resin can be exemplified. In addition, glycidyl ester type epoxy resins obtained by condensation of epichlorohydrin with carboxylic acids such as phthalic acid derivatives and fatty acids, glycidyl amine type epoxy resins obtained by reaction of epichlorohydrin with amines, cyanuric acids, hydantoins, and various Examples thereof include, but are not limited to, epoxy resins modified by various methods.

Specific examples of the unit price epoxy resin include phenyl glycidyl ether, cresyl glycidyl ether, pt-butylphenyl glycidyl ether, butyl glycidyl ether, C12-C14 alcohol glycidyl ether, and the like. Absent.
In addition, the component (B) that can be used in the present invention does not include a compound having one or more epoxy groups and one or more acrylic groups and / or methacrylic groups in one molecule.

  Usually, an epoxy resin is used by adding a curing agent and / or a curing accelerator for curing, but in the present invention, a curing agent curing accelerator is not added. That is, the photocurable composition of the present invention does not contain a curing agent and / or a curing accelerator that reacts with the component (B). In the present invention, the component (B) is added as a plasticizer, and for no clear reason, the component (B) is combined with the component (C) so that the plasticizer does not bleed out during curing. Specific examples of curing agents and curing accelerators include epoxy adduct compounds in which an epoxy resin typified by a bisphenol A type epoxy resin and the like and a tertiary amine compound have reacted to an intermediate stage, 2-methylimidazole, 2-ethylimidazole, 2 Alkyl imidazole compounds such as propyl imidazole, aryl imidazole compounds such as phenyl imidazole and naphthyl imidazole, aminoalkyl imidazole compounds such as 2-aminoethyl imidazole and 2-aminopropyl imidazole, adipic acid dihydrazide, eicosane diacid dihydrazide, 7,11 -Hydrazide compounds such as octadecadiene-1,18-dicarbohydrazide, 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin, amine imide, polyamine, dicyan Amide, and the like.

  It is preferable that 1-200 mass parts of (B) component is added with respect to 100 mass parts of (A) component. More preferably, it is 20-180 mass parts. If the component (B) is 1 part by mass or more, the curing shrinkage can be lowered, and if it is 200 parts by mass or less, the cured product does not bleed out.

Component (C): (meth) acrylic polymer that is liquid at 25 ° C. Component (C) that can be used in the present invention is a (meth) acrylic polymer that is liquid at 25 ° C. In particular, a (meth) acrylic polymer which is liquid at 25 ° C. and does not have a reactive functional group is preferable. In the present invention, the addition of the (meth) acrylic polymer reduces the curing shrinkage without bleeding out the component (B). Specific examples of the component (C) include, but are not limited to, Alfon series UP-1020, UP-1020, UP-1061, UP-1110, UP-1170, etc. manufactured by Toagosei Co., Ltd. .

  In this invention, the sum total of (B) component and (C) component contains 100 mass parts or more with respect to 100 mass parts of (A) component. (A) Curing shrinkage rate can be made low by including 100 mass parts or more of the sum total of (B) component and (C) component with respect to 100 mass parts of component. It is preferable that 1-200 mass parts of (C) component is added with respect to 100 mass parts of (A) component. More preferably, it is 1-150 mass parts. If the component (C) is 1 part by mass or more, the curing shrinkage can be lowered, and if it is 200 parts by mass or less, the cured product does not bleed out.

Component (D): Photoinitiator The component (D) that can be used in the present invention is a photoinitiator. The photoinitiator is not limited as long as it is a radical photoinitiator that generates radical species by energy rays such as visible light, ultraviolet light, X-rays, and electron beams. Specifically, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone, 2-hydroxy Acetophenones such as 2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer; benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; benzophenone, -Methyl benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 2,4,6- Benzophenones such as trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethane ammonium bromide, (4-benzoylbenzyl) trimethylammonium chloride; 2 -Isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy) -3,4-dimethyl -9H- Such Okisanton 9 thioxanthones such Onmesokurorido including but not limited to this.

  It is preferable that 0.1-5.0 mass parts of (D) component is added with respect to 100 mass parts of (A) component. If (D) component is 0.1 mass part or more, photocurability can be maintained. On the other hand, if the component (D) is 5.0 parts by mass or less, storage stability can be maintained without thickening during storage.

(Polymerization inhibitor)
In the photocurable composition of the present invention, a polymerization inhibitor can be used in order to maintain the storage stability. However, when the polymerization inhibitor is added in an excessive amount, the storage stability is improved, while the reactivity is improved. Since it becomes late | slow, it is preferable to set it as 0.001-0.1 mass% with respect to the total amount of a photocurable composition. Specific examples of the polymerization inhibitor include quinone polymerization inhibitors such as hydroquinone, methoxyhydroquinone, benzoquinone, and p-tert-butylcatechol; 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, Alkylphenol polymerization inhibitors such as 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol; alkylated diphenylamine N, N'-diphenyl-p-phenylenediamine, phenothiazine, 4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 1, 4-dihydroxy-2,2,6,6-tetramethylpiperidine, 1 Amine polymerization inhibitors such as hydroxy-4-benzoyloxy-2,2,6,6-tetramethylpiperidine; 2,2,6,6-tetramethylpiperidine-N-oxyl, 4-hydroxy-2,2, Examples include N-oxyl polymerization inhibitors such as 6,6-tetramethylpiperidine-N-oxyl and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl, but are not limited thereto. Is not to be done.

(E) Component: Spherical Resin Beads In addition, spherical resin beads can be added as the (E) component to the photocurable composition of the present invention. When a plate-shaped adherend is bonded and temporarily fixed, a substantially parallel resin layer is formed by adding spherical resin beads as a spacer to the temporary fixing agent. Specific examples of the component (E) include acrylic and urethane resin beads. Resin beads having a sharp particle size distribution are preferable, and the average particle size is preferably 10 to 100 μm. If the average particle size is 10 μm or more, it is easy to peel off during the peeling operation, and if it is 100 μm or less, the thickness of the coating film is stabilized.

  It is preferable that 0.01-10 mass parts of (E) component is added with respect to 100 mass parts of (A) component. By adding 0.01 part by mass or more, the adherends are bonded in parallel. On the other hand, by adding 10 parts by mass or less, it is possible to effectively prevent the medium for peeling from entering the cured product.

(Other additives)
The photocurable composition of the present invention includes a colorant such as a pigment and a dye, an inorganic filler such as metal powder, calcium carbonate, talc, silica, alumina, and aluminum hydroxide within a range that does not impair the characteristics of the present invention. An appropriate amount of other additives such as a flame retardant, an organic filler, a plasticizer, an antioxidant, an antifoaming agent, a coupling agent, a leveling agent, and a rheology control agent may be blended. By these additions, a composition excellent in resin strength, adhesive strength, workability, preservability and the like and a cured product thereof can be obtained.

  The photocurable composition of the present invention can be appropriately removed by a method such as physical peeling, dipping in a peeling medium, peeling off by heating, etc. as a peeling method from the adherend. Examples of the peeling medium include 90 to 100 ° C. warm water or 100 to 200 ° C. medium. As the medium at 100 to 200 ° C., a mixture of water and a water-soluble organic solvent having a boiling point of 100 ° C. or higher can be used. As the water-soluble organic solvent, ethylene glycol, propylene glycol or the like can be used alone or in combination, and can be arbitrarily mixed as long as it can be set to a specific temperature.

  The photocurable composition of the present invention is suitable for applications in which an inorganic substance (adhered body) is temporarily fixed to perform work steps such as cutting and polishing. Examples of inorganic substances (adherents) include silicone wafers, sapphire glass, ceramic materials, optical glass, crystal, and magnetic materials.

  The photocurable composition of the present invention has a viscosity of 500 mPa · s or less, preferably 100 to 500 mPa · s, and a curing shrinkage of 3.0 or less. When the viscosity of the photocurable composition is 500 mPa · s or less, the stringing during coating is small and the leveling property is good. Moreover, if the curing shrinkage ratio of the photocurable composition is 3.0 or less, it can be temporarily fixed satisfactorily without distorting the adherend due to residual stress caused by curing shrinkage that occurs during curing. . In addition, the photocurable composition can perform the measuring method of a viscosity and a cure shrinkage rate by the measuring method as described in a following example.

<Temporary fixative>
The temporary fixing agent of the present invention is characterized by containing the photocurable composition. This configuration is excellent in that when the wafer or the like is temporarily fixed, distortion of the wafer or the like due to curing shrinkage can be effectively suppressed. In the temporary fixing agent of the present invention, the spherical resin beads of component (E) used in the photocurable composition and other additives are not added to the photocurable composition, but instead of the temporary fixing agent. It may be added as a component.

EXAMPLES Next, although an Example is given and this invention is demonstrated further in detail, this invention is not limited only to these Examples. (Hereinafter, the photocurable composition is simply referred to as a composition.)
[Examples 1 to 10, Comparative Examples 1 to 6]
In order to prepare the composition, the following components were prepared.

Component (A): Compound having an acrylic group, Polyester polyfunctional acrylate (Aronix M-8060, manufactured by Toagosei Co., Ltd.), Ethoxylation (9) Trimethylolpropane triacrylate (Sartomer SR502, manufactured by Sartomer Japan Co., Ltd.)
・ Polyester bifunctional acrylate (Aronix M-6200, manufactured by Toagosei Co., Ltd.) ・ Dimethylol tricyclodecane diacrylate (Light acrylate DCP-A, manufactured by Kyoeisha Chemical Co., Ltd.)
・ Polyethylene glycol diacrylate (Light acrylate 9EG-A manufactured by Kyoeisha Chemical Co., Ltd.)
・ Ethylene oxide modified bisphenol A diacrylate (Fancryl FA-321A, manufactured by Hitachi Chemical Co., Ltd.)
・ Isobornyl acrylate (Light acrylate IB-XA, manufactured by Kyoeisha Chemical Co., Ltd.) ・ Phenoxyethyl acrylate (Biscoat # 192, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
Component (B): Epoxy resin / bisphenol F type epoxy resin that is liquid at 25 ° C. (jER806, manufactured by Mitsubishi Chemical Corporation)
・ Phenol novolac type epoxy resin (jER152 manufactured by Mitsubishi Chemical Corporation)
・ Pt-butylphenyl glycidyl ether (ED-509E manufactured by Nagase ChemteX Corporation)
Component (C): (meth) acrylic polymer that is liquid at 25 ° C./solvent-free acrylic polymer of 1000 mPa · s / 25 ° C. (Alfon UP-1000, manufactured by Toagosei Co., Ltd.)
(D) Component: Photoinitiator 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184 BASF)
Other components ・ Pentaerythritol Tetrakis (3-mercaptopropionate) (PEMP SC Organic Chemical Co., Ltd.)
-Hydrophilic fumed silica having a specific surface area of 200 m ² / g (BET method) (Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.).

  In order to adjust the composition, the components (A), (B), (C) and other components are weighed and put into a stirring vessel. Stir for 30 minutes to be uniform while vacuum degassing. Thereafter, the component (D) is weighed and put into a stirring vessel, and stirred for 30 minutes so as to be uniform while vacuum degassing. Detailed preparation amounts follow Table 1, and all numerical values are expressed in parts by mass. In addition, “total of (A) component”, “total of (B) component”, “total of (C) component”, and “total of (B) component and (C) component” are described together.

  In Examples 1 to 10 and Comparative Examples 1 to 6, appearance confirmation, viscosity measurement, bleed out confirmation, cure shrinkage ratio measurement, hardness measurement, and 90 ° peel adhesion strength measurement were performed, and the results are summarized in Table 2. These measurements are the properties of the cured product when the composition or the composition is used as a temporary fixing agent.

[Appearance check]
The composition is placed in a glass jar and visually confirmed when left at 25 ° C. The degree of white turbidity and the separation state of the composition are confirmed and evaluated in the following three stages, and the evaluation results are listed in Table 2 as “Appearance”. Considering the transparency during light irradiation, the appearance is preferably “◯” or “Δ” in the following three-stage evaluation.

(Three-stage evaluation of appearance)
○: Transparent Δ: Translucent ×: Opaque

[Viscosity measurement]
About a composition, "viscosity (mPa * s)" when it measures for 3 minutes at 25 degreeC and 20 rpm with an E-type viscosity meter is measured. The viscosity of the composition is preferably 500 mPa · s or less. If the viscosity is 500 mPa · s or less, there is little stringing during coating, and leveling properties are good.

[Bleedout confirmation]
The composition is dropped into a transparent cylindrical plastic container with a thickness of 3 mm. A plate-like cured product is produced by irradiating ultraviolet rays with an integrated light quantity of 3000 mJ / cm ² . The said hardened | cured material is taken out and an ultraviolet-ray is irradiated again with the integrated light quantity 3000mJ / cm < ² > from the reverse direction to irradiation. The cured product is allowed to stand at 25 ° C., and the surface of the cured product is confirmed by finger touch every day, and it is confirmed whether or not the surface is sticky for 7 days. The day before stickiness occurs is defined as “bleed out (unit: days)”. If no bleed out can be confirmed on the 7th day, write “7 days or more”. From the viewpoint of workability, “bleed out” is preferably 5 days or longer.

[Curing shrinkage measurement]
A composition is dropped into a transparent cylindrical plastic container with a thickness of 3 mm, and ultraviolet rays are irradiated with an integrated light amount of 3000 mJ / cm ² to produce a plate-like cured product. The said hardened | cured material is taken out and an ultraviolet-ray is irradiated again with the integrated light quantity 3000mJ / cm < ² > from the reverse direction to irradiation. The specific gravity (S _g1 ) of the uncured composition is measured by a specific gravity cup method. Moreover, the mass (W _A ) of the cured product in air (W _A ) and the mass (W _B ) of water (distilled water) are measured, and the specific gravity (S _g2 ) of the cured product is determined by the following formula.

Furthermore, from the specific gravity (S _g1 ) of the uncured composition and the specific gravity (S _g2 ) of the cured product, the cure shrinkage rate (ΔV) calculated by the following formula is defined as “curing shrinkage rate (%)”.

  The cure shrinkage rate of the composition is preferably 3.0% or less. If the cure shrinkage is 3.0% or less, the adherend can be satisfactorily fixed satisfactorily without causing stress to remain due to cure shrinkage that occurs when the composition is cured.

[Hardness measurement]
The composition is dropped into a transparent cylindrical plastic container with a thickness of 3 mm. A plate-like cured product is produced by irradiating ultraviolet rays with an integrated light quantity of 3000 mJ / cm ² . The said hardened | cured material is taken out and an ultraviolet-ray is irradiated again with the integrated light quantity 3000mJ / cm < ² > from the reverse direction to irradiation. A cured product formed into a circular shape with a smooth measurement surface is prepared. A hardness meter is a Shore A type hardness meter. The cured product is placed on a measuring table, and while keeping the pressure reference surface of the durometer horizontal to the sample surface, the pressure reference surface and the sample are brought into intimate contact with each other without causing an impact with a force of 5 kgf. When the operation is completed, in principle, the maximum indicated value of the pointer is read as “hardness (no unit)” within 1 second. Considering the relaxation of stress on the adherend, the hardness is preferably softer than A90.

[Measurement of 90 ° peel strength]
A glass plate having a length of 100 mm, a width of 25 mm, and a thickness of 10 mm and a strip-like PET film having the same width are bonded together with the composition, and are bonded by irradiating ultraviolet rays with an integrated light amount of 3000 mJ / cm ² . At this time, the film thickness of the resin (cured product of the composition) is set to 50 μm. Thereafter, the end of the PET film is fixed so as to be pulled in the vertical direction (90 °) with respect to the surface of the fixed glass plate length and width, and the PET film is pulled at a pulling speed of 200 m / min. The maximum strength at that time is defined as “peeling adhesive strength (N / 20 mm)”. The peel strength is preferably 0.1 to 1.0 N / 20 mm. If the peel strength is 0.1 N / 20 mm or more, the protective film (cured product) is stably adhered to the adherend, and if the peel strength is 1.0 N / 20 mm or less, it is peeled off after polishing and cutting. be able to.

Compared with Examples 1-10, the comparative examples 1-5 which do not contain (B) component and (C) component have a bleed-out shorter than 7 days, and the isolation | separation from hardened | cured material is quick. When the present invention is used for temporary fixing, a cured product that is stable for a long period of time is required when working over several days. Moreover, the comparative example 6 in which the sum total of (B) component and (C) component is less than 100 mass parts with respect to 100 mass parts of (A) component has a cure shrinkage rate higher than 3.0%, and with respect to a to-be-adhered body. Stress. Therefore, when temporarily fixing a wafer or the like, it is assumed that the wafer or the like is distorted due to curing shrinkage.

  Although the present invention has a low cure shrinkage ratio, the plasticizer does not bleed out, so the cured product surface is not sticky and has good handleability. Since it is difficult to apply stress to the adherend due to the curing shrinkage rate, it is optimal for temporarily fixing a silicone wafer, sapphire glass, ceramic material, optical glass, crystal, magnetic material, and the like. The adherend can be ground or cut after temporary fixing, and can be used for general purposes in operations having a temporary fixing step.

  In addition, this application is based on the Japan patent application 2014-033167 for which it applied on February 24, 2014, The content of an indication is referred as a whole by reference.

Claims (4)

Including (A) to (D) components,
(A) Component 100 parts by mass , (C) component 6 parts by mass or more, and (B) component and (C) component total 130 parts by mass or more,
(B) The photocurable composition which does not contain the hardening | curing agent which reacts with a component, and does not contain a hardening accelerator.
(A) Component: Compound having an acrylic group (B) Component: Epoxy resin that is liquid at 25 ° C. (C) Component: (meth) acrylic polymer that is liquid at 25 ° C. without a reactive functional group (D) Ingredient: Photoinitiator   The photocurable composition according to claim 1, wherein the component (A) contains a compound having two or more acrylic groups in the molecule.   The photocurable composition according to claim 1 or 2, having a viscosity of 500 mPa · s or less and a curing shrinkage of 3.0 or less.   The temporary fixative containing the photocurable composition in any one of Claims 1-3.