JP6335853B2 - UV curable resin composition for handicrafts - Google Patents

Description

  The present invention is an ultraviolet curable resin used for making accessories such as brooches and small items. It has excellent curability and does not emit white smoke or odor due to reaction heat when cured, and the appearance after curing is also transparent. The present invention relates to an acrylic ultraviolet curable resin composition which is a cured product having excellent properties and almost no yellowing.

  Acrylic photocurable resins are used in many fields in order to give special performance to the surface of plastic films and plastic moldings. For example, hard coat films that are coated on a PET (polyethylene terephthalate) film and given high hardness are used in large quantities in touch panel products, and adhesive films that give viscosity to the film are flat panel display products that are final products. In addition, 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 making use of the hardness and transparency of acrylic resin even outside the field of applying special performance by applying a thin film on the plastic surface (Patent Literature) 1). In such applications, instead of using industrially used dedicated exposure equipment for photocuring, it uses sunlight or commercially available black light, etc., so it is fully cured without leaving stickiness etc. with these light sources Such curing characteristics are required. In addition, since it is used in general households, it is preferred that the odor is low, and since it becomes a thick cured product, there is also a demand for properties such as deformation and yellowing due to curing shrinkage after curing. There was nothing to satisfy.

Japanese Patent Laid-Open No. 10-264184

  The problem of the present invention is that the ultraviolet curable resin used for making accessories such as brooches and small items is excellent in curability and does not emit white smoke or odor due to reaction heat when cured, and after curing The object of the present invention is to provide an acrylic ultraviolet curable resin composition which has a transparent appearance and is a cured product having almost no yellowing.

The invention according to claim 1, an ultraviolet curable resin composition used for own accessories such as brooches and small, that the number average molecular weight having a are polyether backbone is 1,000～7,000 2 UV curing comprising a functional urethane (meth) acrylate resin (A), a monofunctional methacrylate monomer, an aromatic acrylate monomer or an aliphatic acrylate monomer having no polar group (B), and a photopolymerization initiator (C) An ultraviolet curable resin composition, which is a resin composition and has a content of component (A) of 50 to 95 parts by weight with respect to 100 parts by weight of the total composition.

The invention according to claim 2 is the ultraviolet curable resin composition according to claim 1, wherein the monofunctional methacrylate monomer, the aromatic acrylate monomer, or the aliphatic acrylate monomer having no polar group (B) does not contain a trifunctional or higher functionality. I will provide a.

In the invention of claim 3, the aliphatic acrylate monomer having no polar group of the monofunctional methacrylate monomer, aromatic acrylate monomer or aliphatic acrylate monomer having no polar group (B) is aliphatic cyclic or aliphatic The ultraviolet curable resin composition of Claim 1 or 2 which is a group linear structure is provided.

A fourth aspect of the present invention, the polyether backbone of the number average molecular weight of 1,000～7,000 that having a polyether backbone difunctional urethane (meth) acrylate resin (A) is a polyethylene glycol ether or The ultraviolet curable resin composition according to any one of claims 1 to 3, which is polytetramethylene glycol ether.

The composition of the present invention is excellent in curability and does not emit white smoke or off-flavor due to reaction heat when cured, and also has an excellent appearance after curing as an ultraviolet curable resin for handicrafts with little yellowing. Useful.

The composition of the ultraviolet curable resin composition of the present invention is a urethane (meth) acrylate resin (A), an acrylate monomer (B), and a photopolymerization initiator (C). In the present specification, (meth) acrylate includes both acrylate and methacrylate.

The urethane (meth) acrylate resin (A) used in the present invention is produced by adding (meth) acrylate to both ends of a compound obtained by addition reaction of a polyol and a diisocyanate. It has a (meth) acryloyl group. If the number of functional groups is 3 or more, the reaction rate is high and the calorific value is large. The number average molecular weight is an oligomer having a molecular weight of 1,000 to 7,000, and 1,000 to 5,000 is particularly preferable. If the molecular weight is less than 1,000, the resulting molded product has a small cohesive force and thus becomes brittle. If the molecular weight exceeds 7,000, the viscosity becomes high and the work becomes difficult and the curability also decreases. The number average molecular weight (hereinafter referred to as “Mn”) was determined by gel permeation chromatography (column: TSKgel SuperHZ1000, SuperHZ2000, SuperHZ3000 4.6 * 150 each, eluent: tetrahydrofuran, standard sample: TSK polystyrene standard). It can be measured.

  The polyol includes polyether polyol, polyester polyol, polycarbonate polyol, etc., but it is necessary to contain a polyether skeleton in view of 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 examples of the diisocyanate to be subjected to addition reaction with a polyol include hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and hydrogenated tolylene diisocyanate.

Commercially available urethane (meth) acrylate resins having a polyether skeleton include New Frontier R-1220 (Daiichi Kogyo Seiyaku, Mn2,300), SUA-023 (Asia Kogyo, Mn1,000), SUA-017 ( There are Mn4,600) manufactured by Asia Industries. The compounding quantity with respect to 100 weight part of the whole composition of urethane (meth) acrylate resin (A) is 50-95 weight part. If the amount is less than 50 parts by weight, the shrinkage is increased due to increased curing shrinkage, and white smoke is likely to be generated because the reactivity is high. If the amount exceeds 95 parts by weight, the viscosity becomes too high and the workability is lowered. Solubility also decreases.

  The 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 for forming a polymer. If the reactivity is too high, white smoke is generated due to the heat generated by the resin, or thermal deformation occurs, so it is a monofunctional methacrylate monomer or aromatic acrylate monomer that is easy to control the reaction speed, or an aliphatic acrylate monomer that does not have a polar group These can be used alone or in combination of two or more.

Examples of monofunctional methacrylate monomers include propyl methacrylate, butyl methacrylate, hexyl methacrylate, octyl methacrylate, lauryl methacrylate as alkyl esters, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl as those containing hydroxyl groups. Methacrylate includes those containing amino groups, methacrylamide, N, N-dimethylmethacrylamide, N, N-diethylmethacrylamide, N-isopropylmethacrylamide, and isobornyl methacrylate, cyclohexyl methacrylate, di- Examples thereof include cyclopentanyl methacrylate, dicyclopentenyl methacrylate, and adamantanyl methacrylate.

Examples of aromatic acrylate monomers include benzyl acrylate, phenoxyethyl acrylate, methylphenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, EO-modified bisphenol A diacrylate, and the like. Bifunctional is preferred.

Further, aliphatic acrylate monomers having no polar group include propyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, lauryl acrylate, cyclohexyl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, adamantanyl acrylate, etc. However, monofunctional or bifunctional compounds that easily control the reactivity, and those having a cyclic or linear structure are preferable.

  The photopolymerization initiator (C) used in the present invention may be a general-purpose photopolymerization initiator because radicals are generated by irradiation with ultraviolet rays or electron beams, and the radicals trigger a polymerization reaction. 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-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one, 1-hydroxy-cyclohexyl-phenyl -Ketone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy)- Phenyl] -2-hydroxy-2-methyl-1-propan-1-one, etc., which can be used alone or in combination of two or more. It is preferable to mix 1 to 10% by weight with respect to the radically polymerizable component.

In the ultraviolet curable resin composition of the present invention, a tackifier, a plasticizer, an antioxidant pigment, a dye, a light stabilizer, a photosensitizer, a defoamer, and a thickener are added as necessary within the range not impairing performance In addition, various additives such as an ultraviolet absorber and a wettability adjusting agent may be contained.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and demonstrated in detail about this invention, a specific example is shown and it does not specifically limit to these. In addition, when there is no description, it measured on the conditions of 25 degreeC relative humidity 65% of room temperature.

Example 1
In a light-shielding bottle, SUA-023 (manufactured by Asia, PTMG, Mn 1,000) is used as (A), and light ester HOP (N) (manufactured by Kyoeisha Chemical Co., Ltd., 2-hydroxypropyl methacrylate) is used as (B). As a photopolymerization initiator (C), Irgacure 184 (manufactured by BASF) was added in the amount shown in Table 1, and the mixture was stirred until uniform using a stirring defoamer to prepare the resin composition of Example 1.

Examples 2-8
In addition to the materials used in Example 1, SUA-017 (manufactured by Asia, PTMG, Mn 4,600) as (A), and light acrylate DCP-A (manufactured by Kyoeisha Chemical Co., Ltd., dimethylol tri) as (B). Cyclodecane diacrylate) and light ester IB-X (Kyoeisha Chemical Co., Ltd., isobornyl methacrylate) and light acrylate PO-A (Kyoeisha Chemical Co., Ltd., phenoxyethyl acrylate) and LA (Kyoeisha Chemical Co., Ltd., lauryl acrylate) are used. A resin composition was prepared according to the formulation described in 1.

Comparative Examples 1-12
In addition to the materials used in the examples, polyether urethane acrylate SUA-015 (manufactured by Asia, Mn 17,000, bifunctional), polybutadiene urethane methacrylate TE-2000 (manufactured by Nippon Soda, Mn 3,100, bifunctional) ), Polyester-based urethane acrylate UA-122P (Shin-Nakamura Chemical Co., Ltd., Mn1,300, bifunctional), polycarbonate-based urethane acrylate UN-9000PEP (Negami Kogyo Co., Ltd., Mn3,600, bifunctional), isocyanurate-based urethane Acrylic RUA-049X (manufactured by Asia, Mn1,500, trifunctional), aliphatic urethane acrylate EBECRYL8254 (manufactured by Daicel Ornex, Mn1,500, hexafunctional), DPHA (Nippon Kayaku Co., Ltd.) Made Pentaerythritol hexaacrylate), 4-functional acrylate monomer light acrylate PE-4A (Kyoeisha Chemical, pentaerythritol tetraacrylate), trifunctional acrylate monomer FA-731AT (Hitachi Chemical Co., Ltd., ethoxylated isocyanuric acid triacrylate), monofunctional Resin compositions of Comparative Examples 1 to 12 were prepared using the acrylate monomer ACMO (manufactured by KJ Chemicals, acrylic morpholine) with the formulation shown in Table 1.

Preparation of cured product 2 g of UV curable resin was put into a silicone mold with a diameter of 26 mm and a depth of 10 mm, and the illuminance at a wavelength of 365 nm using a commercially available black light irradiation device super resin UV crystal lamp from a height of 5 cm from the resin surface. It was cured by irradiation with a light amount of 2 to 4 mW / cm 2 for 5 minutes. Thereafter, the cured product was taken out from the silicone mold and left at 23 ± 2 ° C. for 30 minutes to prepare.

Table 1

The evaluation method was as follows.

Viscosity: Using a cone plate viscometer RC-550 manufactured by Toki Sangyo Co., Ltd., a cone angle of 3 ° R17.65 was measured at 25 ± 1 ° C. and a rotation speed of 0.5 to 50 rpm.

  Smoke generation: When producing the cured product, the presence or absence of generation of white smoke was visually confirmed.

  Curability: The degree of stickiness of the black light-irradiated surface of the cured product was confirmed by finger touch, and when there was no stickiness, it was rated as ◯, when it was, and when deformation could not be measured, measurement was impossible.

  Formability: When producing the cured product, the shape change before and after curing was visually confirmed.

The evaluation results are shown in Table 2.
Table 2

All the evaluation results of the ultraviolet curable resin compositions of the examples were good. On the other hand, the ultraviolet curable resin composition of the comparative example was not suitable for the present invention in any evaluation of smoke generation, curability and moldability.

Claims (4)

UV curable resin composition used to make accessories such as brooches and accessories
A is a number average molecular weight of 1,000～7,000 urethane bifunctional that having a polyether backbone (meth) acrylate resin (A), the monofunctional methacrylate monomer or an aromatic acrylate monomer or polar group An ultraviolet curable resin composition containing an aliphatic acrylate monomer (B) having no photopolymerization and a photopolymerization initiator (C), wherein the content of the component (A) is 50 to 100 parts by weight based on 100 parts by weight of the total composition. The ultraviolet curable resin composition which is 95 weight part.   The ultraviolet curable resin composition according to claim 1, wherein the monofunctional methacrylate monomer, aromatic acrylate monomer, or aliphatic acrylate monomer having no polar group (B) does not contain three or more functional groups.   The monofunctional methacrylate monomer or aromatic acrylate monomer or the aliphatic acrylate monomer having no polar group of the aliphatic acrylate monomer having no polar group (B) has an aliphatic cyclic or aliphatic linear structure. 1 or 2 ultraviolet curable resin composition. Polyether backbone of the number average molecular weight of 1,000～7,000 that having a polyether backbone difunctional urethane (meth) acrylate resin (A) is, is polyethylene glycol ether or polytetramethylene glycol ether The ultraviolet curable resin composition of any one of Claim 1 to 3.