JP6997564B2 - Injection type composition - Google Patents

Description

The present invention relates to a composition for a casting type, which has a low reaction temperature when cured by an ultraviolet curable type and has excellent moldability.

Acrylic-based photocurable resins are used in many fields to impart special performance to the surface of plastic films and plastic moldings. For example, hard coat films that are applied on PET (polyethylene terephthalate) films to give them high hardness are used in large quantities in touch panel products, and adhesive films that give viscosity to the films are final products of flat panel display products. It is also used as a protective film in the manufacturing process.

It is used as a resin for making accessories such as brooches and small items by taking advantage of the hardness and transparency of acrylic resin, even in fields other than the field of applying a thin film to the surface of such plastics to give them special performance (Patent Documents). 1). In the past, applicants have used bifunctional urethane (meth) acrylate resins with a polyether skeleton with a number average molecular weight of 1,000 to 7,000 and monofunctional methacrylate monomers or aromatic acrylate monomers or fats without polar groups. He has invented a composition comprising a group acrylate monomer and a photopolymerization initiator (Patent Document 2). The present invention was excellent in that it was sufficiently cured without leaving stickiness even with a black light light source, and there was little deformation or yellowing due to curing shrinkage. However, this composition may have a high heat of reaction when it is cured in the injection form, and there is room for improvement in this respect.

Japanese Unexamined Patent Publication No. 10-264184 Japanese Unexamined Patent Publication No. 2017-43703

The subject of the present invention is an ultraviolet curable resin suitable for making accessories such as brooches and small items by itself, which has excellent curability and does not emit white smoke or offensive odor due to a low reaction temperature at the time of curing. Further, it is an object of the present invention to provide a composition for casting mold having excellent moldability in casting mold.

The invention according to claim 1 is an ultraviolet curable resin containing a bifunctional urethane (meth) acrylate resin (A) having a polyether skeleton, a (meth) acrylate monomer (B), and a photopolymerization initiator (C). For casting type, the blending amount of the component (A) is 35 to 85% by weight based on the entire composition, and the content of the component (C) is 10 to 30 parts by weight based on 100 parts by weight of the ultraviolet curing component. The composition is provided.

The invention according to claim 2 includes one or more compounds selected from the group consisting of a (meth) acrylate monomer having a hydroxyl group, dipentaerythritol hexaacrylate, and pentaerythritol tetraacrylate. The composition for casting type according to claim 1 is provided.

The invention according to claim 3 is the injection-forming composition according to claim 1 or 2, wherein the blending amount of the component (B) is 5 to 40% by weight based on the whole composition. offer.

The injection-forming composition according to any one of claims 1 to 3, wherein the invention according to claim 4 has a number average molecular weight of 1,000 to 7,000 according to claim 4. offer.

The composition of the present invention is excellent in curability, does not emit white smoke or offensive odor due to the low reaction temperature at the time of curing, and is excellent in moldability in a casting mold, such as brooches and small items. It is useful as an ultraviolet curable composition for casting, which is suitable for making accessories by yourself.

The composition of the ultraviolet curable resin composition of the present invention is a bifunctional urethane (meth) acrylate resin (A) having a polyether skeleton, a (meth) acrylate monomer (B), and a photopolymerization initiator (C). In addition, in this specification, (meth) acrylate includes both acrylate and methacrylate.

The urethane (meth) acrylate resin (A) used in the present invention is produced by adding (meth) acrylates to both ends of a compound obtained by addition reaction of a polyol and diisocyanate, and has two (meth) acrylates in the molecule. Meta) It has an acryloyl group. If there is one functional group, the reactivity at the time of polymerization is low and the molecular weight does not increase, and if there are three or more functional groups, the reaction rate is too fast and the calorific value becomes large, so that it is unsuitable because it tends to emit smoke or deform.

The polyol includes a polyether polyol, a polyester polyol, a polycarbonate polyol, and the like, but it is necessary to contain a polyether skeleton due to curability and resistance to yellowing, and polyethylene glycol (hereinafter referred to as "PEG"). Diols such as polypropylene glycol (hereinafter referred to as "PPG") and polytetramethylene ether glycol (hereinafter referred to as "PTMG") are preferable. Typical diisocyanates to undergo an addition reaction with a polyol include hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, hydrogenated tolylene diisocyanate and the like.

The number average molecular weight of (A) is preferably 1,000 to 7,000, more preferably 1,000 to 5,000. If the molecular weight is less than 1,000, the obtained molded product has a small cohesive force and becomes brittle, and if it is larger than 7,000, the viscosity becomes high, which makes the work difficult and the curability also deteriorates. The number average molecular weight (hereinafter referred to as "Mn") was calculated by measuring and calculating the molecular weight in terms of standard polystyrene by gel permeation chromatography using a tetrahydrofuran developing solvent on a column of a styrenedivinylbenzene substrate.

The blending amount of the composition (A) with respect to the whole composition is preferably 35 to 85% by weight, more preferably 45 to 75% by weight. When it is 35% by weight or more, the curing speed and the curing shrinkage can be appropriately controlled, and when it is 85% by weight or less, the viscosity suitable for workability can be controlled.

The (meth) acrylate monomer (B) used in the present invention is a reactive diluent for the urethane (meth) acrylate resin (A), and at the same time, is a main component forming a polymer. The number of functional groups may be monofunctional or polyfunctional, and may be used alone or in combination of two or more. The glass transition point (hereinafter referred to as Tg) of the homopolymer is preferably less than 100 ° C. The Tg of the (meth) acrylate is shown below as the value of the homopolymer.

As an example of (B) above, as the monofunctional (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl as an alkyl system are used. (Meta) acrylate, octyl (meth) acrylate, ethylhexyl (meth) acrylate, benzyl (meth) acrylate as an aromatic system, phenoxyethyl acrylate as a hydroxyl group-containing 2-hydroxyethyl (meth) acrylate, 2-Hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate as containing amino groups (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide and N-isopropyl (meth) acrylamide are dicyclopentenyl (meth) acrylates, dicyclopentenyloxyethyl (meth) acrylates and dicyclopentanyl (meth) acrylates as an aliphatic ring formula. , Isobornyl (meth) acrylate and the like. Among these, phenoxyethyl acrylate and 2-hydroxypropyl methacrylate having good compatibility with (A) and having a Tg of less than 100 ° C. are preferable.

Examples of the bifunctional (meth) acrylate include (poly) ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and di (poly) propylene glycol di (meth) acrylate. Propropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, 1.4-butanediol di (meth) acrylate, 4.6-hexanediol di (meth) acrylate, 1.9-nonanediol di (meth) acrylate ) Acrylate, 1.10-decanediol di (meth) acrylate, pentaerythritol di (meth) acrylate and the like.

Further, examples of the trifunctional or higher (meth) acrylate include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, trimethylolpropane tetra (meth) acrylate, and pentaerythryl. Examples thereof include tolltetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. Among these, dipentaerythritol hexaacrylate and pentaerythritol tetraacrylate having good compatibility with (A) and having a Tg of less than 100 ° C. are preferable.

The blending amount of the composition (B) with respect to the whole composition is preferably 5 to 40% by weight, more preferably 10 to 35% by weight. When the content is 5% by weight or more, sufficient reactivity can be ensured, and when the content is 40% by weight or less, the viscosity suitable for workability can be controlled. The ratio of (B) to (A) is preferably (A) / (B) = 90/10 to 50/50.

The photopolymerization initiator (C) used in the present invention generates radicals by irradiation with ultraviolet rays, electron beams, or the like, and the radicals trigger a polymerization reaction, and a general-purpose photopolymerization initiator may be used. By arbitrarily selecting the light absorption wavelength of the polymerization initiator, curability can be imparted over a wide wavelength range from the ultraviolet region to the visible light region. Specifically, 2-hirodoxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane-1-one, 1-hydroxy-cyclohexyl-phenyl -Ketone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1- [4- (2-hydroxyethoxy)- Phenyl] -2-hydroxy-2-methyl-1-propane-1-one and the like, which can be used alone or in combination of two or more.

The blending amount of (C) is 10 to 30 parts by weight with respect to 100 parts by weight of the ultraviolet polymerizable component, and by keeping the photopolymerization initiator in this range, the molecular weight of the cured product is appropriately controlled and excessive. It is possible to prevent heat generation. If the blending amount is less than 10 parts by weight, the calorific value tends to increase due to the progress of the polymerization reaction, and if it exceeds 30 parts by weight, the storage stability tends to decrease, which is unsuitable.

The viscosity of the present composition at 25 ° C. is preferably 1000 to 30000 mPa · s, more preferably 1000 to 25000 mPa · s. When it is 1000 mPa · s or more, workability is improved and casting work becomes easy, and when it is 30,000 mPa · s or less, the reproducibility of casting and air bubble removal are improved.

The compositions of the present invention include plasticizers, antioxidant pigments, dyes, light stabilizers, photosensitizers, defoamers, thickeners, UV absorbers, and wetts, as required, to the extent that performance is not impaired. Various additives such as sex modifiers may be contained.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but only specific examples thereof are shown, and the present invention is not particularly limited thereto. Unless otherwise indicated, the measurement was performed under the conditions that the room temperature was 25 ° C. and the relative humidity was 65%.

Example 1
In the light-shielding bottle, SUA-023 (manufactured by Asia Industry Co., Ltd., polyether urethane acrylate, Mn1,000, bifunctional) as the above (A), and light ester HOP (N) (manufactured by Kyoeisha Chemical Co., Ltd.) as the above (B). 2-Hydroxypropyl methacrylate) was added as a photopolymerization initiator (C) in an amount shown in Table 1 and stirred with a stirring defoamer until uniform, and the resin composition of Example 1. I adjusted things.

Examples 2 to 13
In addition to the materials used in Example 1, SUA-024 (polyether-based urethane acrylate, Mn1,300, bifunctional) and SUA-017 (manufactured by Asiatic Industry Co., Ltd., polyether-based) as the above (A). Urethane acrylate, Mn4, 600, bifunctional) as the above (B), MIRAMER M-300 (Miwon, Trimethylol propanetriacrylate ) and Aronix M-240 (Toa Synthetic, PEG # 200 diacrylate ) and light. Acrylate PO-A (Phenoxyethyl acrylate manufactured by Kyoeisha Chemical Co., Ltd.), Irgacure1173 (manufactured by BASF Japan) and EsacureKIP-150 (manufactured by iGM) as a photopolymerization initiator (C), and epoxy ester 3000A (Kyoeisha Co., Ltd.) as an acrylate resin. Using an epoxy acrylate (bifunctional) manufactured by Kagaku Co., Ltd., the resin compositions of Examples 2 to 13 were prepared by stirring with a stirring defoaming machine using a stirring defoaming machine according to the formulation shown in Table 1.

Comparative Examples 1 to 6
In addition to the materials used in the examples, UA-9000PEP (manufactured by Negami Kogyo Co., Ltd., polyester-based urethane acrylate, bifunctional), TE-2000 (manufactured by Nippon Soda Co., Ltd., polybutadiene-based urethane methacrylate, bifunctional), as an acrylate resin composition, RUA-051 (isocyanurate-based urethane acrylate, trifunctional) manufactured by Asia Industries Co., Ltd. and light ester IB-X (isobornyl methacrylate manufactured by Kyoeisha Chemical Co., Ltd.) as the above (B) were used in the formulation shown in Table 2. The resin compositions of Comparative Examples 1 to 6 were prepared by stirring until uniform using a stirring defoaming machine.

Preparation of cured product 2 g of UV curable resin at room temperature is put into a silicone mold with a diameter of 26 mm and a depth of 10 mm, and from a height of 5 cm from the resin surface, a commercially available black light irradiation device Super Resin UV Crystal Lamp ( Using 36 W), the cells were irradiated with a light amount of 2 to 4 mW / cm2 at a wavelength of 365 nm for 5 minutes to cure. After that, the cured product was taken out from the silicone mold and left at 23 ± 2 ° C. for 30 minutes to prepare the product.

Table 1

Table 2

The evaluation method was as follows.

Viscosity: Using a cone plate type viscometer RC-550 manufactured by Toki Sangyo, the cone angle is 3 ° R17.65 and the temperature is 25 ± 1 ° C. 10 rpm, 5000 to 10000 mPa · s was measured at 5 rpm, and 10000 to 30000 mPa · s was measured at 2 rpm.

Curability: The degree of stickiness of the black light-irradiated surface of the cured product was confirmed by touching with a finger.

Moldability: When the cured product was produced, the shape change before and after curing was visually confirmed, and if there was no shape change, it was marked as ◯, and if there was, it was marked as x.

Heat generation temperature: When the cured product is produced at room temperature, a thermolabel 3E (trade name: manufactured by Nichiyosho Gakken Kogyo Co., Ltd.) is attached to the side surface of the silicone mold, and the maximum temperature during curing is set to the heat generation temperature of 70 ° C or lower. The case was marked with ◯, and the case of over 70 ° C was marked with x.

The evaluation results of the examples are shown in Table 3.
Table 3

Table 4 shows the evaluation results of the comparative examples.
Table 4

The resin composition of the example had good curability, moldability, and heat generation temperature.

On the other hand, Comparative Examples 1 and 2 in which (C) is less than 10 parts by weight have a high heat generation temperature, and Comparative Examples 3 to 6 other than the polyether urethane acrylate are unsuitable for evaluation of curability, moldability, or heat generation temperature. It was not suitable for the present invention.

The composition for casting type of the present invention is excellent in curability, does not emit white smoke or offensive odor due to the low reaction temperature at the time of curing, and is excellent in moldability in casting type. It is useful as an ultraviolet curable resin suitable for making accessories such as brooches and accessories.

Claims (4)

An ultraviolet curable resin containing a bifunctional urethane (meth) acrylate resin (A) having a polyether skeleton, a (meth) acrylate monomer (B), and a photopolymerization initiator (C), wherein the component (A) is blended. A composition for casting type, wherein the amount is 35 to 85% by weight based on the whole composition, and the content of the component (C) is 10 to 30 parts by weight based on 100 parts by weight of the ultraviolet curable component. The first aspect of the present invention, wherein (B) contains one or more compounds selected from the group consisting of a (meth) acrylate monomer having a hydroxyl group, dipentaerythritol hexaacrylate, and pentaerythritol tetraacrylate. Injection type composition. The composition for casting type according to claim 1 or 2, wherein the blending amount of the component (B) is 5 to 40% by weight based on the entire composition. The composition for casting type according to any one of claims 1 to 3, wherein the number average molecular weight of (A) is 1,000 to 7,000 .