WO2020110990A1

WO2020110990A1 - Urethane (meth)acrylate resin, curable resin composition, and cured product

Info

Publication number: WO2020110990A1
Application number: PCT/JP2019/045947
Authority: WO
Inventors: 竜也宇多村; 達之熊野; 久憲石田; 瑞生畠中
Original assignee: 三菱瓦斯化学株式会社
Priority date: 2018-11-29
Filing date: 2019-11-25
Publication date: 2020-06-04
Also published as: CN113166363A; TWI822913B; JP7355033B2; CN113166363B; TW202028280A; JPWO2020110990A1

Abstract

Provided is a urethane (meth)acrylate resin obtained by reacting: a polyol-modified aromatic hydrocarbon formaldehyde resin, in which an aromatic hydrocarbon formaldehyde resin is modified by a polyol; an aromatic-group-containing diisocyanate; and a hydroxyl-group-containing (meth)acrylate compound.

Description

Urethane (meth)acrylate resin, curable resin composition, and cured product

The present invention relates to a urethane (meth)acrylate resin, a curable resin composition, and a cured product.

In recent years, the hardness of anti-reflection coatings such as protective coating materials for preventing scratches and contamination of various base materials, adhesives for various base materials, sealing materials, film type liquid crystal elements, touch panels, and plastic optical parts There is a demand for a curable resin composition capable of forming a cured film having excellent flexibility, scratch resistance, abrasion resistance, low curl property, high refractive index, adhesion and transparency. Among these required performances, in recent years, it has been particularly demanded that the adhesion, flexibility, and hardness are compatible. In order to meet such requirements, various compositions have been proposed, but a curable resin composition having characteristics that a cured film has high hardness and also has excellent adhesion and flexibility is provided. The current situation is that it has not been obtained yet.

For example, in Patent Document 1, a urethane (meth) having a bisphenolmethane structure in a molecule, which is a reaction product of a (meth)acrylate having one hydroxyl group in one molecule, an aromatic diisocyanate, and an optional diol compound. A resin composition for an optical material has been proposed, which contains an acrylate, a diluent and methylbenzoyl formate as a photopolymerization initiator.
Patent Document 2 proposes an active energy ray-curable resin composition containing a specific urethane (meth)acrylate oligomer as an active energy ray-curable resin composition having excellent adhesion to a polycarbonate substrate. ing.
Patent Document 3 proposes a cured film that is excellent in hardness and scratch resistance and has less curl and cracks, and a urethane (meth)acrylate compound that provides the cured film.
Patent Document 4 relates to an active energy ray-curable resin composition containing a urethane (meth)acrylate composition and a coating agent, and when a cured coating film is formed, curing shrinkage is small and curling is difficult, Further, an active energy ray-curable resin composition capable of forming a coating film excellent in flexibility has been proposed.

Japanese Patent Laid-Open No. 10-324726 JP, 2006-45361, A International Publication No. 2010/146801 JP, 2017-203068, A

As described above, various urethane (meth)acrylate resin compositions have been proposed, but a curable resin composition that gives a cured film excellent in hardness, solvent resistance, adhesion, low curling property, and flexibility. Is not obtained at present.
In Patent Document 1, the main purpose is fast curing and adhesion to a methacrylic resin, but performances such as flexibility and low curl are not mentioned.
Although Patent Document 2 has excellent adhesiveness to a polycarbonate plate, it does not mention performance such as adhesiveness to other resin substrates, hardness, solvent resistance, low curl property, and flexibility.
Although Patent Documents 3 and 4 are excellent in hardness, they are intended to improve flexibility and low curl, but there is still room for improvement in flexibility and low curl.

The present invention has been made in view of the above circumstances, and in addition to hardness, solvent resistance, flexibility and low curl, a urethane (meth)acrylate resin capable of giving a cured film excellent in adhesion, Another object is to provide a curable resin composition containing the resin and a cured product of the resin composition.

As a result of intensive studies, the present inventors have obtained by reacting a polyol-modified aromatic hydrocarbon formaldehyde resin obtained by modifying an aromatic hydrocarbon formaldehyde resin with a polyol, an aromatic group-containing diisocyanate, and a hydroxyl group-containing acrylate. It has been found that a urethane (meth)acrylate resin that can be used to solve the above-mentioned problems has led to the completion of the present invention.

That is, the present invention is as follows.
(1)
Urethane (meth)acrylate obtained by reacting a polyol-modified aromatic hydrocarbon formaldehyde resin obtained by modifying an aromatic hydrocarbon formaldehyde resin with a polyol, an aromatic group-containing diisocyanate, and a hydroxyl group-containing (meth)acrylate compound. resin.
(2)
The urethane (meth)acrylate resin according to (1), which has a weight average molecular weight (Mw) of 500 to 100,000.
(3)
The urethane (meth)acrylate resin according to (1) or (2), wherein the polyol modified aromatic hydrocarbon formaldehyde resin has a weight average molecular weight of 300 to 5,000.
(4)
The urethane (meth)acrylate resin according to any one of (1) to (3), wherein the polyol-modified aromatic hydrocarbon formaldehyde resin has a hydroxyl value of 100 to 400 mgKOH/g.
(5)
The molar ratio (OH/NCO) between the hydroxyl group of the polyol-modified aromatic hydrocarbon formaldehyde resin and the isocyanate group of the aromatic group-containing diisocyanate is 0.50 to 0.95, and the polyol-modified aromatic carbon The molar ratio (OH ^T /NCO) of the total hydroxyl groups of the hydrogen formaldehyde resin and the hydroxyl groups of the hydroxyl group-containing (meth)acrylate compound to the isocyanate groups of the aromatic group-containing diisocyanate is 1.0 to 1.2. The urethane (meth)acrylate resin according to any one of (1) to (4), which is obtained by reacting in the following ratio.
(6)
The urethane (meth)acrylate resin according to any one of (1) to (5), wherein the polyol-modified aromatic hydrocarbon formaldehyde resin contains an ethylene glycol-modified xylene formaldehyde resin.
(7)
The urethane (meth)acrylate according to any one of (1) to (6), wherein the aromatic group-containing diisocyanate is at least one aromatic diisocyanate selected from the group consisting of diphenylmethane diisocyanate and tolylene diisocyanate. resin.
(8)
A curable resin composition containing the urethane (meth)acrylate resin according to any one of (1) to (7).
(9)
A cured product obtained by curing the curable resin composition according to (8).

According to the present invention, it is possible to provide a cured film having hardness, solvent resistance, flexibility, and low curl, and further having excellent adhesion.

Hereinafter, a mode for carrying out the present invention (hereinafter, simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the gist. In the present specification, the description “XX to YY” means “XX or more and YY or less”.

“(Meth)acrylate” in the present specification means both “acrylate” and “methacrylate”. The same applies to other similar terms (“(meth)acrylic acid”, “(meth)acryloyl group”, etc.).

[Urethane (meth)acrylate resin]
The urethane (meth)acrylate resin of this embodiment is obtained by reacting a polyol-modified aromatic hydrocarbon formaldehyde resin, an aromatic group-containing diisocyanate, and a hydroxyl group-containing (meth)acrylate compound.
Since the urethane (meth)acrylate resin of the present embodiment contains a (meth)acryloyl group, it can be easily cured by irradiation with UV or heating. The obtained cured product has high hardness and high solvent resistance, and further has excellent adhesion and flexibility. It is considered that this is due to the excellent adhesiveness and flexibility which are the inherent properties of the aromatic hydrocarbon formaldehyde resin.

The urethane (meth)acrylate resin of the present embodiment is obtained from a polyol-modified aromatic hydrocarbon formaldehyde resin having a structure that is difficult to specify by analysis, and therefore, the urethane (meth)acrylate resin also has the same structure. Difficult to analyze and identify.

The weight average molecular weight (Mw) of the urethane (meth)acrylate resin of the present embodiment is preferably 500 to 100,000, more preferably 500 to 70,000, in terms of polystyrene, from the viewpoint of improving adhesion. , And more preferably 700 to 50,000. The weight average molecular weight (Mw) can be measured by gel permeation chromatography (GPC).

As described above, the urethane (meth)acrylate resin of the present embodiment is obtained by reacting a polyol-modified aromatic hydrocarbon formaldehyde resin, an aromatic group-containing diisocyanate, and a hydroxyl group-containing (meth)acrylate compound. Specifically, the molar ratio (OH/NCO) of the hydroxyl group of the above polyol-modified aromatic hydrocarbon formaldehyde resin to the isocyanate group of the above aromatic group-containing diisocyanate is 0.50 to 0.95, and the above polyols are The molar ratio (OH ^T /NCO) of the total hydroxyl groups of the modified aromatic hydrocarbon formaldehyde resin and the hydroxyl groups of the hydroxyl group-containing (meth)acrylate compound to the isocyanate groups of the aromatic group-containing diisocyanate is 1.0 to Those obtained by reacting at a ratio of 1.2 are preferable.
Adhesion and flexibility when the molar ratios of the hydrogen groups of the polyol-modified aromatic hydrocarbon formaldehyde resin, the isocyanate groups of the aromatic group-containing diisocyanate, and the hydroxyl groups of the hydroxyl group-containing (meth)acrylate are within the above ranges. It is possible to obtain a urethane (meth)acrylate resin having excellent hardness and high solvent resistance.

The molar ratio (OH/NCO) of the hydroxyl group of the above polyol-modified aromatic hydrocarbon formaldehyde resin to the isocyanate group of the aromatic group-containing diisocyanate is more preferably 0.50 to 0.90, and 0.50. More preferably, it is from 0.80.
The molar ratio of the total hydroxyl groups (OH ^T ) of the hydroxyl groups of the polyol-modified aromatic hydrocarbon formaldehyde resin and the hydroxyl groups of the hydroxyl group-containing (meth)acrylate compound to the isocyanate groups of the aromatic group-containing diisocyanate (OH ^T / NCO) is more preferably 1.0 to 1.1, still more preferably 1.0 to 1.05.

The hydroxyl value of the urethane (meth)acrylate resin of the present embodiment is preferably 40 mgKOH/g or less, more preferably 20 mgKOH/g or less, from the viewpoint of UV curability. The lower limit is not particularly limited, but is, for example, 5 mgKOH/g or more. The hydroxyl value can be measured by a method based on the acetic anhydride-pyridine method (JIS K 1557-1:2007).
The urethane (meth)acrylate in the present embodiment can sufficiently urethanize the hydroxyl group (alcoholic hydroxyl group) contained in the polyol-modified aromatic hydrocarbon formaldehyde resin. Therefore, it becomes possible to keep the hydroxyl value of the urethane (meth)acrylate resin low.

[Polyol-modified aromatic hydrocarbon formaldehyde resin]
In the present embodiment, the polyol-modified aromatic hydrocarbon formaldehyde resin refers to an aromatic hydrocarbon formaldehyde resin modified with polyols.

(Aromatic hydrocarbon formaldehyde resin)
The aromatic hydrocarbon formaldehyde resin is obtained by reacting an aromatic hydrocarbon with formaldehyde. As the aromatic hydrocarbon, benzene, toluene, xylene, mesitylene, ethylbenzene, propylbenzene, decylbenzene, cyclohexylbenzene, biphenyl, methylbiphenyl, naphthalene, methylnaphthalene, dimethylnaphthalene, ethylnaphthalene, anthracene, methylanthracene, dimethylanthracene, At least one selected from the group consisting of ethylanthracene and binaphthyl can be mentioned. From the viewpoint of more excellent adhesiveness, at least one selected from the group consisting of xylene, toluene, and mesitylene is preferable, and xylene is more preferable. Aromatic hydrocarbon formaldehyde resin of the present embodiment, from the same viewpoint as above, a xylene formaldehyde resin obtained by reacting xylene with formaldehyde, a toluene formaldehyde resin obtained by reacting toluene with formaldehyde, and It preferably contains at least one selected from mesitylene formaldehyde resins obtained by reacting mesitylene and formaldehyde, and more preferably contains xylene formaldehyde resin.

The aromatic hydrocarbon formaldehyde resin may be a commercially available product or may be prepared by a known method. Examples of commercially available products include "Nikanol LL" manufactured by Fudo Co., Ltd. Known methods include, for example, a method of subjecting an aromatic hydrocarbon and formaldehyde to a condensation reaction in the presence of a catalyst by a method described in Japanese Patent Publication No. 37-5747.

(Polyols)
Aliphatic polyols are preferred as the polyols. The aliphatic polyol is not particularly limited, but trimethylolpropane, neopentyl glycol, ester glycol, spiroglycol, pentaerythritol, ethylene glycol, diethylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol. 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, 1,2-hexanediol, trimethylolethane, 1,2-octanediol, 1,10 -Decanediol, 3-hexyne-2,5-diol, 2,5-dimethyl-3-hexyne-2,5-diol, 2,2,4-trimethyl-1,3-pentanediol, polyethylene glycol, and poly Examples thereof include oxypropylene glycol. Among these, trimethylolpropane and ethylene glycol are more preferable. These polyols may be used alone or in combination of two or more.

From the viewpoint of flexibility, the polyol-modified aromatic hydrocarbon formaldehyde resin preferably contains at least one selected from a polyol-modified xylene formaldehyde resin, a polyol-modified toluene formaldehyde resin, and a polyol-modified mesitylene formaldehyde resin, It is more preferable to include a polyol-modified xylene formaldehyde resin. Above all, it is preferable to contain an ethylene glycol-modified xylene formaldehyde resin.

The polyol-modified aromatic hydrocarbon formaldehyde resin of the present embodiment may be a commercially available product or may be prepared by a known method. Examples of commercially available products include "K-100", "K-140", "K-100E" and "K-140E" manufactured by Fudoh Co., Ltd. As a known method, for example, as described in JP-A No. 04-224815, it can be produced by subjecting an aromatic hydrocarbon formaldehyde resin and a polyol to a condensation reaction under an acidic catalyst.

[Physical properties of polyol-modified aromatic hydrocarbon formaldehyde resin]
The hydroxyl value (OH value) of the polyol-modified aromatic hydrocarbon formaldehyde resin is preferably 100 to 400 mgKOH/g, more preferably 130 to 300 mgKOH/g, and further preferably 140 to 190 mgKOH/g. More preferable. When the hydroxyl value is in the above range, the properties (hardness, solvent resistance, etc.) of the resulting urethane (meth)acrylate and the properties of the polyol-modified aromatic hydrocarbon formaldehyde resin (adhesion, flexibility, etc.) can be improved. You can secure a good balance. The hydroxyl value can be measured by a method based on the acetic anhydride-pyridine method (JIS K 1557-1:2007).

The weight average molecular weight of GPC of the polyol-modified aromatic hydrocarbon formaldehyde resin of this embodiment is preferably 300 to 5,000, more preferably 400 to 1,000, and more preferably 500 to 1,000 in terms of polystyrene. It is more preferably 800 and even more preferably 550 to 700. When the weight average molecular weight is within the above range, it is possible to obtain a urethane (meth)acrylate resin which gives a cured film having excellent hardness, solvent resistance, flexibility and the like and also having excellent adhesion.

[Aromatic group-containing diisocyanate]
The aromatic group-containing diisocyanate in the present embodiment refers to an isocyanate compound having two isocyanate groups present in the molecule and an aromatic ring, and is not particularly limited as long as the requirements are satisfied. Specific aromatic group-containing diisocyanates include 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, diphenylmethane diisocyanate, naphthene diisocyanate, tolylene diisocyanate, tolidine diisocyanate, diphenylmethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, At least one selected from the group consisting of dibenzyl diisocyanate, phenylene diisocyanate, xylene diisocyanate and the like can be mentioned.
Among them, it is more preferable to use at least one aromatic diisocyanate selected from the group consisting of diphenylmethane diisocyanate and tolylene diisocyanate as the aromatic group-containing diisocyanate. The "aromatic diisocyanate" refers to an isocyanate compound in which two isocyanate groups existing in the molecule are directly bonded to an aromatic ring.

[Hydroxyl group-containing (meth)acrylate compound]
The hydroxyl group-containing (meth)acrylate compound in the present embodiment is not particularly limited as long as it is a compound having a hydroxyl group and a (meth)acryloyl group in at least one molecule. Specific examples of the hydroxyl group-containing (meth)acrylate compound include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 4-hydroxycyclohexyl (meth)acrylate. Hydroxyalkyl (meth)acrylates such as 5-hydroxycyclooctyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, pentaerythritol tri(meth)acrylate; polyethylene glycol mono(meth)acrylate, polypropylene Glycol mono(meth)acrylate; Hydroxy group-containing (meth)acrylamide such as N-methylol(meth)acrylamide; Reaction product obtained by reacting vinyl alcohol, vinylphenol, diglycidyl ester of bisphenol A with (meth)acrylic acid Etc. can be mentioned. Among these, hydroxyalkyl (meth)acrylate is preferable, and 2-hydroxyethyl (meth)acrylate is more preferable.

[Method for producing urethane (meth)acrylate resin]
The urethane (meth)acrylate resin in the present embodiment is prepared by adding the above-mentioned polyol-modified aromatic hydrocarbon formaldehyde resin, aromatic group-containing diisocyanate compound, and hydroxyl group-containing (meth)acrylate to an organic solvent and reacting them. Can be manufactured.
It can also be obtained by reacting a hydroxyl group-containing (meth)acrylate with a terminal isocyanate urethane prepolymer obtained by reacting the above-mentioned polyol-modified aromatic hydrocarbon formaldehyde resin with an aromatic group-containing diisocyanate compound.
All of the above reactions are reactions of a hydroxyl group and an isocyanate group, which are inert to the isocyanate group, that is, in the presence of a hydrocarbon-based or ester-based organic solvent, a common solvent such as dibutyltin dilaurate or dibutyltin diethylhexoate is used. Using a urethanization catalyst, it can be continuously carried out at a temperature of usually 10 to 100° C., preferably 30 to 90° C. for about 1 to 20 hours.

As described above, the molar ratio (OH/NCO) of the hydroxyl group of the polyol-modified aromatic hydrocarbon formaldehyde resin to the isocyanate group of the aromatic group-containing diisocyanate is 0.50 to 0.95, and the polyols are The molar ratio (OH ^T /NCO) of the total hydroxyl groups of the modified aromatic hydrocarbon formaldehyde resin and the hydroxyl groups of the hydroxyl group-containing (meth)acrylate compound to the isocyanate groups of the aromatic group-containing diisocyanate is 1.0 to By reacting so as to be 1.2, it is possible to produce a urethane (meth)acrylate resin having excellent adhesion and flexibility, high hardness and high solvent resistance, which is preferable. A more preferable molar ratio is as described above.

Known urethanization catalysts such as dibutyltin dilaurate, dioctyltin dilaurate, bismuth tris-2-ethylhexanoate and zirconium tetraacetylacetonate can be used. The urethanization catalyst can be used in an amount of usually 50 to 1,000 mass ppm, preferably 50 to 500 mass ppm, based on the total mass of the raw materials used in the reaction. However, in order to keep the properties of the obtained urethane (meth)acrylate good, it is preferable that the amount of the urethanization catalyst used is small.
The reaction in the presence of (meth)acrylate is preferably carried out in the presence of air or oxygen for the purpose of preventing the polymerization of the (meth)acryloyl group. The reaction may be carried out by adding a commonly used polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether or 2,6-di-tert-butyl-4-methylphenol (BHT).

[Curable resin composition containing urethane (meth)acrylate resin]
The curable resin composition of the present embodiment contains the urethane (meth)acrylate resin.
The curable resin composition contains a (meth)acrylate resin other than the urethane (meth)acrylate resin, an epoxy resin, a cyanate ester compound, a phenol resin, an oxetane resin, as long as the characteristics of the present embodiment are not impaired. Resins such as benzoxazine compounds, various polymer compounds such as oligomers and elastomers, monomers having a polymerizable functional group such as compounds having an ethylenically unsaturated group, maleimide compounds, fillers, flame retardants, silane coupling agents , A wetting dispersant, a photopolymerization initiator, a photocuring initiator, a thermosetting accelerator, various additives and the like. The components contained in the curable resin composition of the present embodiment are not particularly limited as long as they are generally used.

As various additives, ultraviolet absorbers, antioxidants, fluorescent whitening agents, photosensitizers, dyes, pigments, thickeners, lubricants, defoamers, leveling agents, surface conditioners, brighteners, polymerization inhibition Agents and the like.
The above-mentioned components other than the urethane (meth)acrylate resin may be used alone or in an appropriate mixture of two or more. Various amounts of each component can be prepared depending on the application.

In the curable resin composition of the present embodiment, in order to obtain the characteristics of the present embodiment, it is preferable that the urethane (meth)acrylate resin is 40% by mass or more. The urethane (meth)acrylate resin in the curable resin composition is more preferably 60% by mass or more, further preferably 70% by mass or more.

The method for producing the curable resin composition of this embodiment is not particularly limited. For example, a method may be mentioned in which the above-mentioned components are sequentially mixed in a solvent and sufficiently stirred.
At the time of producing the cured resin composition, a known treatment (stirring, mixing, kneading treatment, etc.) for uniformly dissolving or dispersing each component can be performed, if necessary. Stirring, mixing, kneading treatment, for example, a stirring device for the purpose of dispersion such as an ultrasonic homogenizer, a device for mixing such as a three-roll, ball mill, bead mill, sand mill, or revolution or rotation type mixing device, etc. Can be appropriately performed by using a known device.

When preparing the composition of the present embodiment, an organic solvent can be used if necessary. The type of organic solvent is not particularly limited as long as it can dissolve the resin in the composition.
The organic solvent is not particularly limited, but examples thereof include ketones such as acetone, methyl ethyl ketone, and methyl cellosolve; aromatic hydrocarbons such as toluene and xylene; amides such as dimethylformamide; propylene glycol monomethyl ether and its acetate. Can be mentioned. These organic solvents can be used alone or in an appropriate mixture of two or more.

[Cured product]
The cured product of this embodiment is obtained by curing the cured resin composition. A cured product can be obtained by various known methods. Examples of the curing method include irradiation with UV and EUV, heating, and the like, and these can be used in combination.
Since the urethane (meth)acrylate resin of the present embodiment has high reactivity, it is suitable for a highly productive process of instant curing with UV or EUV. Further, since it has high reactivity, a high quality cured product can be stably supplied. The urethane (meth)acrylate resin and the cured product of the present embodiment are suitably used for a protective coating material, an adhesive for various base materials, a sealing material, a film type liquid crystal element, a touch panel, an antireflection film for plastic optical parts, and the like. be able to.

Case of ultraviolet irradiation can adjust its dose optionally, the irradiation can be carried out, for example ^{0.05J / cm 2 ~ 10J / cm} 2 of about dose.
The heating conditions may be appropriately selected depending on the urethane (meth)acrylate resin, each component in the composition containing the resin, the content of the resin and each component, and the like, but preferably 150° C. to 220° C. The temperature is selected in the range of 20 to 180 minutes at 0°C, more preferably in the range of 160 to 200°C for 30 to 150 minutes.

[Use]
The urethane (meth)acrylate resin, curable resin composition and cured product of the present embodiment can be used for various purposes.
For example, adhesives, adhesives, home electric appliances such as touch panels, various lens materials, optical materials such as dental materials and medical materials, paints, coating agents, automotive applications such as primers, construction materials, shoes, bags, school bags, etc. Examples include leather and synthetic leather applications, polymerization raw materials, molding materials, gas separation membranes, fuel cell membranes, optical waveguides, holograms, and the like.

In particular, various UV curable paints/coating materials for automobiles, mobile terminals/light electrical appliances, optical disks, optical fibers, cosmetic containers, building materials/floor self-healing paints/coatings; UV curable inkjet inks, UV curable resin for nanoimprint, UV curable resin for 3D printer, UV ink such as photosensitive conductive paste, UV curable adhesive, OCA for touch panel, OCR for touch panel, UV adhesive such as sealing material for organic EL; Sealing Materials; Buffer coat film materials; Lenses (pickup lenses, microlenses, spectacle lenses); Polarizing films (for liquid crystal displays, etc.); Antireflection films (display devices, antireflection films, etc.); Touch panel films; Flexible substrate films PDP (plasma display), LCD (liquid crystal display), VFD (vacuum fluorescent display), SED (surface conduction electron-emitting device display), FED (field emission display), NED (nano-emissive display), CRT, electron It can be suitably used as an optical material for films (filters, protective films, antireflection films, etc.) for displays (especially thin displays) such as paper.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.
The evaluation methods used in this example and the comparative example are as follows.

(1) Weight average molecular weight (Mw)
The weight average molecular weight (Mw) in terms of polystyrene was determined by GPC analysis. The equipment and analysis conditions used for the analysis are as follows.
Equipment: Shodex GPC-101 type (Product of Showa Denko KK)
Column: Shodex LF-804 x 3 (Showa Denko KK product)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min.
Column temperature: 40°C
Detector: RI (differential refraction detector)

(2) Hydroxyl value (OH value, mgKOH/g)
It was measured according to the acetic anhydride-pyridine method (JIS K 1557-1:2007).

(3) Rubbing test The obtained cured coating film was rubbed with a cotton swab impregnated with acetone. When the surface was undissolved, it was evaluated as ○, and when it was dissolved, it was evaluated as ×.

(4) Pencil hardness The obtained cured coating film was measured according to JIS K 5600-5-4:1999.

(5) Flexibility The obtained cured coating film was evaluated based on the following criteria according to JIS K 5600-5-1:1999.
◯: With a core rod having a diameter of 2 mm, the cured film is not cracked or peeled.
X: A core rod having a diameter of 2 mm causes cracking or peeling of the cured film.

(6) Curl property (height at the four corners)
An easy-adhesion PET film (manufactured by Toyobo Co., Ltd., Cosmo Shine A4100) was applied, and the cured coating film was cut out to have a size of 10 cm×10 cm, and the average value (mm) of the rectangular rising height was measured as the curl value did. The evaluation criteria are shown below.
◯: The average value of the height of the squares jumped up was less than 5 mm.
X: The average value of the height of the squares jumped up was 5 mm or more.

(7) Adhesion The obtained cured coating film was evaluated for adhesion by making 100 square notches at 1 mm intervals according to JIS K 5600-5-6:1999. The evaluation criteria are shown below.
◯: The number of squares that did not peel off was 90 or more in 100 squares.
X: The number of squares that did not peel off was less than 90 in 100 squares.

<Example 1>
240 parts by mass of toluene, 205 parts by mass of diphenylmethane diisocyanate, K-140E (manufactured by Fudou Co., Ltd., ethylene glycol modified xylene resin, hydroxyl value: 177 mg KOH/g, weight average molecular weight: 580) 260 parts by mass in a 2 L three-necked flask, 2- 95 parts by mass of hydroxyethyl acrylate, 0.2 parts by mass of dibutyltin dilaurate, and 0.4 parts by mass of 2,6-tert-butyl-4-methylphenol (BHT) were charged and uniformly mixed (ethylene glycol modified xylene resin. The molar ratio (OH/NCO) of the hydroxyl groups of OH to the isocyanate groups of diphenylmethane diisocyanate is 0.50, and the molar ratio of the total hydroxyl groups (ethylene glycol modified xylene resin + 2-hydroxyethyl acrylate) to the isocyanate groups of diphenylmethane diisocyanate (OH ^T /NCO) is 1.0). After uniformly mixing, the temperature was raised to 70° C., the reaction was terminated by stirring the solution for 15 hours while controlling the temperature at 70° C., and the desired urethane (meth)acrylate resin solution A (weight average molecular weight: 3517) was obtained. Obtained. The resin concentration in the obtained urethane (meth)acrylate resin solution A was 70% by mass.

<Example 2>
Using 161 parts by mass of tolylene diisocyanate instead of diphenylmethane diisocyanate, 292 parts by mass of K-140E (manufactured by Fudo Co., Ltd., ethylene glycol modified xylene resin, hydroxyl value: 177 mgKOH/g, weight average molecular weight: 580), 2-hydroxy A urethane (meth)acrylate resin solution B (weight average molecular weight: 2038) was obtained in the same manner as in Example 1 except that 107 parts by mass of ethyl acrylate was used (hydroxyl group of ethylene glycol-modified xylene resin and tolylene diisocyanate). Is 0.50, and the molar ratio (OH ^T /NCO) of the total hydroxyl groups (ethylene glycol modified xylene resin + 2-hydroxyethyl acrylate) to the isocyanate groups of tolylene diisocyanate is (OH ^T /NCO). 1.0). The resin concentration in the obtained urethane (meth)acrylate resin solution B was 70% by mass.

<Example 3>
170 parts by mass of metaxylylene diisocyanate was used instead of diphenylmethane diisocyanate, and 286 parts by mass of K-140E (manufactured by Fudo Co., Ltd., ethylene glycol modified xylene resin, hydroxyl value: 177 mgKOH/g, weight average molecular weight: 580) Urethane (meth)acrylate resin solution C (weight average molecular weight: 2727) was obtained in the same manner as in Example 1 except that 105 parts by mass of hydroxyethyl acrylate was used (hydroxyl group of ethylene glycol-modified xylene resin and meta-xylylene). The molar ratio (OH/NCO) of the diisocyanate to the isocyanate group is 0.50, and the molar ratio of the total hydroxyl groups (ethylene glycol modified xylene resin + 2-hydroxyethyl acrylate) to the isocyanate group of the metaxylylene diisocyanate (OH ^T / NCO) is 1.0). The resin concentration in the obtained urethane (meth)acrylate resin solution C was 70% by mass.

<Comparative Example 1>
211 parts by mass of dicyclohexylmethane 4,4′-diisocyanate was used instead of diphenylmethane diisocyanate, and 255 parts by mass of K-140E (manufactured by Fudo Co., Ltd., ethylene glycol modified xylene resin, hydroxyl value: 177 mgKOH/g, weight average molecular weight: 580) Parts, a urethane (meth)acrylate resin solution D (weight average molecular weight: 3621) was obtained in the same manner as in Example 1 except that 94 parts by mass of 2-hydroxyethyl acrylate was used. The resin concentration in the obtained urethane (meth)acrylate resin solution D was 70%.

<Comparative example 2>
157 parts by mass of hexamethylene diisocyanate was used instead of diphenylmethane diisocyanate, and 295 parts by mass of K-140E (manufactured by Fudo Co., Ltd., ethylene glycol modified xylene resin, hydroxyl value: 177 mgKOH/g, weight average molecular weight: 580), 2-hydroxy A urethane (meth)acrylate resin solution E (weight average molecular weight: 3039) was obtained in the same manner as in Example 1 except that 108 parts by mass of ethyl acrylate was used. The resin concentration in the obtained urethane (meth)acrylate resin solution E was 70%.

<Comparative example 3>
170 parts by mass of 1,3-bis(isocyanatomethyl)cyclohexane was used instead of diphenylmethane diisocyanate, and K-140E (manufactured by Fudo Co., Ltd., ethylene glycol modified xylene resin, hydroxyl value: 177 mgKOH/g, weight average molecular weight: 580) Was used, and a urethane (meth)acrylate resin solution F (weight average molecular weight: 2803) was obtained in the same manner as in Example 1, except that 286 parts by weight and 105 parts by weight of 2-hydroxyethyl acrylate were used. The resin concentration in the obtained urethane (meth)acrylate resin solution F was 70%.

<Examples 4 to 6 and Comparative Examples 4 to 6>
The urethane (meth)acrylate resin solutions A to F obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were mixed with a photopolymerization initiator (manufactured by BASF, Irgacure (registered trademark) 184) to obtain a curable composition. A resin composition was obtained.

Then, this curable resin composition was applied onto various base materials using a bar coater, and then at 100° C. for 2 min. After drying, UV irradiation was performed using an ultraviolet irradiation device (high pressure mercury lamp, manufactured by Eye Graphics Co., Ltd., ECS-1511U) so as to be 500 mJ/cm ² to obtain a cured coating film. Each of the above evaluation tests was carried out on the obtained cured coating film. The results are shown in Table 1.
The base material used is as follows.
・PET ("A4100" manufactured by Toyobo Co., Ltd., thickness: 100 μm)
・Steel plate (“PB-N144” manufactured by Paltec Co., Ltd., thickness: 200 μm)
・Polycarbonate plate (general-purpose product, thickness: 2 mm)
・Acrylic plate (general-purpose product, thickness: 2 mm)
・ABS (acrylonitrile-butadiene-styrene copolymer resin) plate (general purpose product, thickness: 2 mm)

As compared with Examples 4 to 6, in Comparative Examples 4 to 6, the adhesion to the plastic substrate was lowered. It is presumed that this is because the urethane (meth)acrylate resin used in Comparative Examples 4 to 6 does not have an aromatic ring in the diisocyanate part, but the present invention is not limited to this.

Claims

Urethane (meth)acrylate obtained by reacting a polyol-modified aromatic hydrocarbon formaldehyde resin obtained by modifying an aromatic hydrocarbon formaldehyde resin with a polyol, an aromatic group-containing diisocyanate, and a hydroxyl group-containing (meth)acrylate compound. resin.
The urethane (meth)acrylate resin according to claim 1, which has a weight average molecular weight (Mw) of 500 to 100,000.
The urethane (meth)acrylate resin according to claim 1 or 2, wherein the polyol-modified aromatic hydrocarbon formaldehyde resin has a weight average molecular weight of 300 to 5,000.
The urethane (meth)acrylate resin according to any one of claims 1 to 3, wherein the hydroxyl value of the polyol-modified aromatic hydrocarbon formaldehyde resin is 100 to 400 mgKOH/g.
The molar ratio (OH/NCO) between the hydroxyl group of the polyol-modified aromatic hydrocarbon formaldehyde resin and the isocyanate group of the aromatic group-containing diisocyanate is 0.50 to 0.95, and the polyol-modified aromatic carbon The molar ratio (OH T /NCO) of the total hydroxyl groups of the hydrogen formaldehyde resin and the hydroxyl groups of the hydroxyl group-containing (meth)acrylate compound to the isocyanate groups of the aromatic group-containing diisocyanate is 1.0 to 1.2. The urethane (meth)acrylate resin according to any one of claims 1 to 4, which is obtained by reacting in the following ratio.
The urethane (meth)acrylate resin according to any one of claims 1 to 5, wherein the polyol-modified aromatic hydrocarbon formaldehyde resin contains an ethylene glycol-modified xylene formaldehyde resin.
The urethane (meth)acrylate resin according to any one of claims 1 to 6, wherein the aromatic group-containing diisocyanate is at least one aromatic diisocyanate selected from the group consisting of diphenylmethane diisocyanate and tolylene diisocyanate.
A curable resin composition containing the urethane (meth)acrylate resin according to any one of claims 1 to 7.
A cured product obtained by curing the curable resin composition according to claim 8.