WO2014045782A1

WO2014045782A1 - Ultraviolet curable urethane acrylate composition, thin film molded body, optical film and method for manufacturing thin film molded body

Info

Publication number: WO2014045782A1
Application number: PCT/JP2013/072188
Authority: WO
Inventors: 大地樋口; 保坂元; 優子瀧川
Original assignee: Dic株式会社
Priority date: 2012-09-20
Filing date: 2013-08-20
Publication date: 2014-03-27
Also published as: CN104619735B; CN104619735A; TW201418303A; KR101508706B1; KR20150009605A; JPWO2014045782A1; JP5633768B2; TWI487723B

Abstract

The present invention is ultraviolet curable without comprising a photoinitiator and exhibits excellent self-healing property, yellowing resistance, transparency and adequate flexibility. An ultraviolet curable urethane acrylate composition which comprises an urethane acrylate oligomer (E) having a (meth)acryloyl group at the molecular terminals which is obtained by the addition reaction of a (meth)acrylic compound (D) having a hydroxyl group with respect to an urethane prepolymer (C) having an NCO group at the molecular terminals which is obtained by reacting a polyol (A) without an aromatic backbone and a polyisocyanate (B) without an aromatic backbone. This composition further comprises 0.2 to 80 parts by mass of an organic solvent (F) without a specific aromatic backbone and does not comprise a photoinitiator. The (meth)acrylic equivalent of (E) is 450 to 1100 g/equivalent and a tanδ peak temperature measured by dynamic viscoelasticity analysis in accordance with JIS K 0129 using a 100 μm thick film produced with the composition is -8 to 45°C.

Description

Ultraviolet curable urethane acrylate composition, thin film molded article, optical film, and method for producing thin film molded article

The present invention relates to an ultraviolet curable urethane acrylate composition, a thin film molded article, an optical film using the same, and a method for producing a thin film molded article.

More specifically, the ultraviolet curable urethane acrylate composition of the present invention does not use a photopolymerization initiator at all unlike the conventional ultraviolet curable composition, and contains a specific organic solvent as a diluent solvent, Excellent ultraviolet curability can be expressed.

In addition, the thin film molded body (for example, a film, a sheet, etc.) of the present invention can exhibit excellent performance such as “self-repairing”, yellowing resistance, transparency, etc., in which a scratch once attached is quickly recovered.

Furthermore, unlike the prior art, the thin film molded body of the present invention does not contain any photopolymerization initiator, so that the degree of yellowing due to ultraviolet irradiation is extremely small, there is no yellowing over time, and the photopolymerization initiator Excellent effects such as no contamination of the contact product of the molded product due to unreacted components and decomposition products, such as optical members (for example, optical films, optical sheets, etc.), optical coating materials, It is useful in a wide range of fields that require advanced performance such as yellowing resistance, flexibility, and transparency, such as fibers, electronic electrical materials, food packages, cosmetic packages, and decorative films.

Recently, various IT devices with high performance, high functionality, and miniaturization, such as personal computers, copiers, mobile phones, smartphones, and tablet computers, are rapidly spreading in various environments at work and at home. In particular, since the operation is easy and high functionality is easy to achieve, the touch panel system is expected to greatly expand and expand the application field.

Generally, a touch panel has a multilayer structure, and a hard coat layer is provided on the outermost layer for the purpose of preventing damage (improving durability) and maintaining aesthetics. However, the hard coat layer is hard to be scratched, but once it has been scratched, the scratch is not restored, and there is a tendency for the dirt to adhere to the scratch and to spread the contamination starting from the scratch. It was a cause of damage.

Therefore, recently, for example, a resin coating is applied to the surface of an article such as a plastic member or a metal member. In particular, a hard coating layer having a higher hardness is provided on the surface of a transparent plastic film such as a touch panel, and further measures for preventing scratches are taken.

However, the hard coating layer with high hardness as described above is hard and brittle, so that (1) cracks and scratches are likely to occur on long-term use, and (2) scratches on the surface are restored once. (3) When the base material to be coated is made of a soft material such as polycarbonate, the target level of high hardness does not appear and the durability on the outermost layer cannot be secured. There were problems such as.

On the other hand, a thermosetting composition having a self-healing property having a function of recovering a scratch once attached to the surface naturally (hereinafter referred to as “self-healing property”) has been proposed. Such a conventional thermosetting composition having self-healing properties is flexible and elastic, and can be restored to its original state after a few seconds to several minutes even if it has a dent like a scratch. There was an advantage that good initial scratch resistance could be maintained over a period of time.

However, conventional thermosetting compositions having self-healing properties are (1) extremely inferior in productivity because heating for 30 minutes or more is indispensable for curing during processing, (2) When the substrate is vulnerable to heat, there are problems such as difficulty in use by heating.

Further, an ultraviolet curable (hereinafter also referred to as “UV curable”) composition having a self-repairing property has been proposed with respect to the thermosetting composition. Adoption of the ultraviolet curable composition has advantages such as shortening the curing time and energy cost.

However, conventional ultraviolet curable compositions having self-healing properties (1) are not sufficiently self-healing when coated thinly on a substrate, and the strength of the outermost layer of the cured coating film cannot be secured. (2) Since the photopolymerization initiator is essential, the initial yellowness is high (when the yellowness is high, the yellowness is particularly noticeable at the corners of the article, which impairs the commercial value), ( 3) There were large practical problems such as yellowing resistance after the durability test being inferior to that of the two-part curable resin composition.

Various proposals have been made to improve such problems.
For example, a photocurable composition having a self-healing property containing 0.1 to 10 parts by mass of a photopolymerization initiator with respect to 100 parts by mass of a reactive polymer having a (meth) acryloyl group represented by a specific general formula, Is known (for example, see Patent Document 1).

The photocurable composition described in Patent Document 1 introduces a (meth) acryloyl group into a rubber component through a urethane bond with a diisocyanate compound, and combines it with a photopolymerization initiator to impart photocurability. In addition to good self-healing properties, it is possible to form a coating film that imparts a coating film appearance excellent in processability and warpage resistance.

However, the photocurable composition described in Patent Document 1 is (1) self-healing property is still insufficient, and it is difficult to recover the original state of a dent such as a scratch in a short time. 2) Since it contains an essential photopolymerization initiator, the resulting cured product has a high yellowness at the initial stage of molding, and (3) it is further yellowed after heat and ultraviolet resistance tests, resulting in poor yellowing resistance. There was a problem such as that.

In addition, in the ultraviolet curable urethane acrylate composition containing a photopolymerization initiator as in Patent Document 1, unreacted components and decomposition products of the photopolymerization initiator migrate to the surface of the coating film or molded product, and the thin film molded product. When laminating (for example, a film, a sheet, etc.), an article in contact with the thin film molded body is contaminated, or the decomposed photopolymerization initiator is changed to a yellow substance to deteriorate the yellowness of the molded body. It was. Especially in fields such as food packaging and cosmetic packaging where emphasis is placed on aesthetics and transparency, such unreacted components and degradation products are impurities that should be removed, and are very important from the standpoint of quality (hygiene, design, etc.). It was a problem.

The yellowing phenomenon induced by such a photopolymerization initiator changes to a yellow substance when the decomposed photopolymerization initiator recombines and promotes yellowing of the cured product, resulting in high-grade transparency. It is considered to be a main cause of reducing the performance of optical members (for example, films, sheets, fibers, paints, etc.) used for required optical applications. In particular, photopolymerization initiators having an aromatic skeleton are commonly used because the aromatic ring absorbs light energy and efficiently generates radicals. However, it becomes a quinoid structure due to the aromatic ring during recombination. , Has the disadvantage of forming a yellow chromophore.

As described above, in the conventional ultraviolet curable urethane acrylate composition, (1) the self-healing property is still insufficient, (2) the photopolymerization initiator is contained, and therefore yellowing occurs. 3) When an unreacted component or decomposition product of the photopolymerization initiator migrates and a thin film molded body (for example, a film, a sheet, etc.) is laminated, an article in contact with the coating film or the molded body is contaminated. ) There were still problems to be solved, such as degradation of the photopolymerization initiator to a yellow substance and deterioration of the color tone of the thin film molded article.

JP 2010-260905 A

The purpose of the present invention is that, unlike the prior art, an excellent ultraviolet curability can be expressed without containing a photopolymerization initiator, and an excellent self-repairing property, yellowing resistance, transparency, and appropriate flexibility are expressed. An object of the present invention is to provide a possible ultraviolet curable urethane acrylate composition, a thin film molded article, an optical film using the composition, and a method for producing the thin film molded article.

As a result of intensive studies to solve the above-mentioned problems, the present inventors contain a urethane acrylate oligomer having a (meth) acryloyl group at the molecular terminal and an organic solvent having no aromatic skeleton as a diluting solvent. In the ultraviolet curable urethane acrylate composition containing no photopolymerization initiator, the urethane acrylate oligomer has a (meth) acrylic equivalent in a specific range, and a thickness of 100 μm prepared by the ultraviolet curable urethane acrylate composition. Tan δ (loss factor) peak temperature measured by dynamic viscoelasticity analysis in accordance with JIS K 0129 using a specific film, so that excellent self-repairing property, yellowing resistance, transparency, and moderate To obtain an ultraviolet curable urethane acrylate composition capable of exhibiting excellent flexibility As a result, the present invention has been completed.

That is, the present invention provides a urethane prepolymer (C) having an isocyanate group at the molecular end obtained by reacting a polyol (A) having no aromatic skeleton with a polyisocyanate (B) having no aromatic skeleton. In contrast, an ultraviolet curable urethane acrylate composition containing a urethane acrylate oligomer (E) having a (meth) acryloyl group at a molecular end obtained by addition reaction of a (meth) acrylic compound (D) having a hydroxyl group. And 0.2 to 80% by mass of an organic solvent (F) having at least one aromatic skeleton selected from the group consisting of ketone solvents, amide solvents, and alkyl halide solvents. It is an ultraviolet curable urethane acrylate composition containing no initiator, and is a (meta) of the urethane acrylate oligomer (E). The tan δ peak temperature measured by dynamic viscoelasticity analysis in accordance with JIS K 0129 using a 100 μm thick film having an acrylic equivalent in the range of 450 to 1100 g / equivalent and made from the ultraviolet curable urethane acrylate composition. The present invention relates to an ultraviolet curable urethane acrylate composition having a temperature range of −8 to 45 ° C.

The present invention relates to a thin film molded article having a cured coating film of the ultraviolet curable urethane acrylate composition on a substrate.

The present invention relates to a thin film molded article obtained by applying the ultraviolet curable urethane acrylate composition onto a substrate and curing it, and having a thickness in the range of 10 to 800 μm.

The present invention also provides an optical film having a cured coating film of the ultraviolet curable urethane acrylate composition, wherein the cured film has a total light transmission measured in accordance with JIS K7361-1 in a film thickness of 50 to 200 μm. The present invention relates to an optical film characterized in that the rate is 92% or more.

Furthermore, the present invention is characterized in that the ultraviolet curable urethane acrylate composition is applied onto a substrate, irradiated with ultraviolet rays, and then the organic solvent (F) is volatilized to form a cured coating film. The present invention relates to a method for manufacturing a thin film molded body.

Unlike the conventional ultraviolet curable composition, the ultraviolet curable urethane acrylate composition of the present invention can exhibit excellent photocurability without containing any photopolymerization initiator, and has excellent self-repairing property and yellowing resistance. Therefore, for example, optical members (for example, optical films, optical sheets, etc.), optical coating materials, fibers, electronic electrical materials, food packaging materials, cosmetic packages, decorations. Useful for a wide range of applications such as film.

<Ultraviolet curable urethane acrylate composition>
Unlike the conventional ultraviolet curable composition, the ultraviolet curable urethane acrylate composition of the present invention does not contain any photopolymerization initiator.

The ultraviolet curable urethane acrylate composition of the present invention has an isocyanate group at a molecular terminal obtained by reacting a polyol (A) having no aromatic skeleton with a polyisocyanate (B) having no aromatic skeleton. A urethane acrylate oligomer (E) having a (meth) acryloyl group at the molecular end obtained by addition reaction of a (meth) acrylic compound (D) having a hydroxyl group with respect to the urethane prepolymer (C), and a specific one described later Essentially contains an organic solvent (F).

The ultraviolet curable urethane acrylate composition of the present invention is completely different from an ultraviolet curable composition containing a conventional photopolymerization initiator, and has no aromatic skeleton even if it does not contain any photopolymerization initiator. By containing a urethane acrylate oligomer (E) having a (meth) acryloyl group at the molecular end obtained from the raw material and a specific organic solvent (F) having no aromatic skeleton, an ultraviolet curing reaction can be carried out. It is possible to proceed normally and quickly.

Moreover, the UV curable urethane acrylate composition of the present invention is completely different from the UV curable composition using a conventional photopolymerization initiator, and has excellent self-healing properties, yellowing resistance, transparency, and moderate flexibility. Sex can be expressed.

(A) Polyol having no aromatic skeleton The above (A) to (F) constituting the ultraviolet curable urethane acrylate composition of the present invention will be described in detail below.
Examples of the polyol (A) having no aromatic skeleton used in the present invention include aliphatic polyols and alicyclic polyols, and examples thereof include polyester polyols, polyether polyols, polycarbonate polyols, and low molecular weight glycols.

The polyester polyol is usually produced from dicarboxylic acid and diol as raw materials.

The dicarboxylic acid used for the production of the polyester polyol is a dicarboxylic acid having no aromatic skeleton, such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and the like. These may be used alone or in combination of two or more.

In addition to the dicarboxylic acid, derivatives thereof can also be used, and examples thereof include lower alkyl esters such as methyl ester, acid anhydrides, acid halides, and the like.

The diol used in the production of the polyester polyol is a diol having no aromatic skeleton, such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1, 4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, trimethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 3-methyl-1 , 5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, aliphatic diol such as 2-methyl-1,3-propanediol, or 1,4-cyclohexanediol, 1,4-cyclohexane Dimethanol, hydrogen An alicyclic diol such as pressurized bisphenol A and the like. These may be used alone or in combination of two or more.

Further, at the time of production of the polyester polyol, a trifunctional or higher functional hydroxyl group-containing compound such as glycerin, trimethylol ethane, trimethylol propane, sorbitol, sucrose, aconite sugar, etc., as long as the object of the present invention is not impaired together with the diol. May be used in combination.

In the present invention, in addition to the polyester polyol, a polyester polyol obtained by ring-opening addition polymerization of a lactone (eg, ε-caprolactone, γ-butyrolactone, etc.) can also be used.

The number average molecular weight (hereinafter also referred to as “Mn”) of the polyester polyol is determined when the urethane prepolymer (C) having an isocyanate group at the molecular terminal (hereinafter referred to as “isocyanate group-terminated urethane prepolymer (C)”) is used. The target melt viscosity is desirably set in consideration of the above, preferably in the range of 300 to 5000, more preferably in the range of 500 to 3500. If the Mn of the polyester polyol is within such a range, an abnormal viscosity increase of the isocyanate group-terminated urethane prepolymer (C) does not occur, the reaction can be controlled normally, and a urethane prepolymer having an appropriate melt viscosity can be obtained. Can do.

Examples of the polyester polyol include polyester diols and polyamide polyester diols obtained by using dicarboxylic acids, diols, diamines and the like other than the above.

Examples of the polyether polyol include polyethylene glycol (PEG), polypropylene glycol (PPG), polyethylene propylene glycol (PEPG), polytetramethylene glycol (PTMG), glycerin, trimethylolpropane, pentaerythritol, sorbitol and the like. Examples thereof include poly (oxyalkylene) glycols obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide using a compound having at least three hydroxyl groups as a starting material. Among these, polytetramethylene glycol (PTMG, Mn = 650 to 2000) is preferable. The polyether polyol may have any structure of linear, branched and cyclic.

Mn of the polyether polyol is preferably in the range of 500 to 3500, more preferably in the range of 600 to 3000, and still more preferably in the range of 650 to 2000. If the Mn of the polyether polyol is within such a range, an abnormal viscosity increase of the isocyanate group-terminated urethane prepolymer (C) does not occur, and a urethane prepolymer having an appropriate melt viscosity can be obtained.

Further, as the polycarbonate polyol, for example, a polyol obtained by an esterification reaction of carbonic acid and an aliphatic polyol can be used. Specifically, diols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol or polytetramethylene glycol (PTMG), and dimethyl carbonate And reaction products with phosgene and the like. These may be used alone or in combination of two or more.

Examples of the low molecular weight glycol include ethylene glycol (EG), 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentane. Diol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl- Aliphatic diols such as 1,3-propanediol and 2-methyl-1,3-propanediol, or alicyclic diols such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and hydrogenated bisphenol A, Or glycerin, trimethyl Rupuropan and trifunctional or more hydroxyl group-containing compound such as pentaerythritol. Among these 1,4-butanediol, trimethylol propane is preferred. The low molecular weight glycol may have a linear, branched, or cyclic structure.

The molecular weight of the low molecular weight glycol is preferably in the range of 62 to 300, more preferably in the range of 62 to 200. When the molecular weight of the low molecular weight glycol is within such a range, when used as a polyol (A) having no aromatic skeleton, the reactivity can be controlled more easily and the moldability (yield, molding unevenness) can be controlled. ) Is preferable.

As the polyol (A) having no aromatic skeleton, for example, acrylic polyol, polyolefin polyol, castor oil-based polyol, and the like can be used.

Polyamines can also be used in combination. Examples of the polyamine that can be used include ethylenediamine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, diaminocyclohexane, methyldiaminocyclohexane, piperazine, norbornenediamine, and the like.

(B) Polyisocyanate not having aromatic skeleton Next, the polyisocyanate (B) having no aromatic skeleton used in the present invention will be described below.

The “polyisocyanate” in the present invention refers to a compound having two or more isocyanate groups (hereinafter also referred to as “NCO groups”) in the molecule.

In the present invention, as the polyisocyanate (B) having no aromatic skeleton, any of known aliphatic polyisocyanates and alicyclic polyisocyanates can be used. These may be used alone or in combination of two or more.

Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (HDI), dimer acid diisocyanate, and lysine diisocyanate. Although it does not specifically limit in a commercial item, For example, all are the Duranate TSA-100, TSS-100, TSE-100, TSR-100, THA-100, D101, A201H, TKA-100 etc. by Asahi Kasei Corporation. It is done.

Examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate (H ₁₂ MDI), hydrogenated xylylene diisocyanate, cyclohexane diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, norbornene diisocyanate. Etc.

However, polyisocyanates (B ′) having an aromatic skeleton such as diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), tetramethylxylylene diisocyanate, etc. in the presence of a photopolymerization initiator as in the past. (Hereinafter also referred to as “aromatic polyisocyanate”), when the isocyanate group-terminated urethane prepolymer is produced, the absorbance of the aromatic structure possessed by the aromatic polyisocyanate becomes too high, and the curing reaction caused by ultraviolet irradiation. Does not proceed sufficiently, and the aromatic polyisocyanate itself turns yellow during ultraviolet irradiation. For this reason, it is very difficult to obtain an ultraviolet curable urethane acrylate composition suitable for applications such as optical members (eg, films, sheets, etc.), fibers, paints, packaging materials, etc. that require particularly high-quality transparency. It was.

The present invention does not use an aromatic polyisocyanate, uses an aliphatic polyisocyanate or an alicyclic polyisocyanate as a polyisocyanate (B) having no aromatic skeleton, and has an aromatic skeleton as a diluent solvent. By using essentially no specific organic solvent (F), the ultraviolet curing reaction can proceed without any trouble without yellowing during ultraviolet irradiation, and the resulting composition has excellent yellowing resistance. Therefore, it does not change color for a long time.

(C) Urethane Prepolymer Having an Isocyanate Group at the Molecular Terminal Next, the urethane prepolymer (C) having an isocyanate group at the molecular terminal used in the present invention (hereinafter referred to as “isocyanate group-terminated urethane prepolymer (C)”). explain.

The isocyanate group-terminated urethane prepolymer (C) reacts according to a known method using the polyol (A) having no aromatic skeleton and the polyisocyanate (B) having no aromatic skeleton as essential. The reaction method and reaction conditions are not particularly limited.

In the isocyanate group-terminated urethane prepolymer (C), the isocyanate group (hereinafter referred to as “NCO group”) of the polyisocyanate (B) is also referred to as a hydroxyl group (hereinafter referred to as “OH group”) of the polyol (A). ) Can be reacted by a known method with an excess amount in an equivalent ratio.

In the synthesis of the isocyanate group-terminated urethane prepolymer (C), the isocyanate equivalent (hereinafter referred to as “NCO equivalent”) of the polyisocyanate (B) and the hydroxyl equivalent (hereinafter referred to as “OH equivalent”) of the polyol (A). (Ie, [NCO / OH equivalent ratio]) may be set in consideration of target physical properties, product quality, reaction behavior, and the like, and preferably 1.5 / 1.0 to 10.0 / A range of 1.0 equivalent ratio, more preferably a range of 2.0 / 1.0 to 5.0 / 1.0 equivalent ratio.

The method for synthesizing the isocyanate group-terminated urethane prepolymer (C) is not particularly limited. For example, [Method 1] The polyol (A) from which water has been removed is dropped into the polyisocyanate (B) charged in the reaction vessel. In a method in which the polyol (A) is charged by an appropriate means such as splitting or batch, and the reaction is carried out until the hydroxyl group of the polyol (A) substantially disappears, or [Method 2] to the polyol (A) from which the water charged in the reaction vessel has been removed. And a method in which the polyisocyanate (B) is charged by an appropriate means such as dropping, splitting, or batch, and reacted until the hydroxyl group of the polyol (A) is substantially eliminated.

In order to allow the reaction to proceed safely and normally while gently controlling the exotherm during the reaction, a charging method by dropping or dividing is preferred.

The production of the isocyanate group-terminated urethane prepolymer (C) is usually carried out in the absence of a solvent, but may be carried out by reacting in a solvent. When making it react in a solvent, what is necessary is just to use the solvent which does not inhibit reaction, and the kind is not specifically limited. It is desirable to remove the solvent used in the reaction by an appropriate method such as heating under reduced pressure or distilling off the thin film during or after the reaction.

The reaction conditions (temperature, time, pressure, etc.) of the isocyanate group-terminated urethane prepolymer (C) may be set within a range that can be normally controlled in consideration of reaction behavior (safety, stability), product quality, etc. There is no particular limitation. Usually, the reaction is preferably performed at a reaction temperature of 50 to 90 ° C. and a reaction time of 2 to 24 hours. The pressure may be normal pressure, pressurization, or reduced pressure.

The reaction method can be selected from known reaction methods such as batch, semi-continuous, and continuous, and is not particularly limited.

Further, when the isocyanate group-terminated urethane prepolymer (C) is produced, a urethanization catalyst can be used as necessary. The said catalyst can be suitably added in the arbitrary steps of a raw material preparation process and a reaction process. Moreover, the addition method of a catalyst is not specifically limited, such as lump, division | segmentation, and continuous.

As the urethanization catalyst, known catalysts can be used, for example, nitrogen-containing compounds such as triethylamine, tributylamine, benzyldibutylamine, triethylenediamine, N-methylmorpholine; or titanium tetrabutoxide, dibutyltin oxide, dibutyltin dilaurate, Organometallic compounds such as tin 2-ethylcaproate, zinc naphthenate, cobalt naphthenate, zinc 2-ethylcaproate, molybdenum glycolate, potassium acetate, zinc stearate, tin octylate, dibutyltin dilaurate; or iron chloride, Examples include inorganic compounds such as zinc chloride.

Usually, the reaction is preferably carried out in an inert gas atmosphere such as nitrogen or argon, but it may be carried out in a dry air atmosphere or in a condition not containing moisture such as sealed conditions.

The isocyanate equivalent (hereinafter also referred to as “NCO equivalent”) of the isocyanate group-terminated urethane prepolymer (C) is preferably in the range of 100 to 10,000, more preferably in the range of 200 to 1,000. If the NCO equivalent of (C) is within such a range, an abnormal viscosity increase does not occur and a urethane prepolymer excellent in workability can be obtained.

The “isocyanate equivalent” (unit: g / eq, ie g / equivalent) in the present invention is a value measured according to JIS K 7301 described later.

(D) (Meth) acrylic compound having a hydroxyl group Next, the (meth) acrylic compound (D) having a hydroxyl group, which is added to the isocyanate group-terminated urethane prepolymer (C), will be described.

In the present invention, a part or all of the isocyanate groups in the isocyanate group-terminated urethane prepolymer (C) is subjected to an addition reaction with the (meth) acrylic compound (D) having a hydroxyl group, and a (meth) acryloyl group is present at the molecular end. The urethane acrylate oligomer (E) having

By introducing a double bond by modification with the (meth) acrylic compound (D) having the hydroxyl group to the isocyanate group-terminated urethane prepolymer (C), a curing reaction at a double bond site by ultraviolet irradiation occurs rapidly, and light Even if it does not contain any polymerization initiator, unprecedented performance such as excellent UV curability, shape retention after application to a substrate, mechanical strength, durability, and transparency can be expressed.

Examples of the (meth) acrylic compound (D) having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) ) Acrylate, pentaerythritol triacrylate, etc. Among them, for example, 2-hydroxyethyl acrylate (2HEA), 4 is excellent in that it is excellent in rapid curability by ultraviolet irradiation and particularly improves mechanical strength. -Hydroxybutyl acrylate (4HBA) is preferred. These may be used alone or in combination of two or more.

(E) Urethane acrylate oligomer having a (meth) acryloyl group at the molecular end Next, a urethane acrylate oligomer (E) having a (meth) acryloyl group at the molecular end used in the present invention (hereinafter referred to as “urethane acrylate oligomer (E)”) .).

The urethane acrylate oligomer (E) is a (meth) acrylic compound (D) having a hydroxyl group, preferably in the range of 0.5 to 300 parts by mass with respect to 100 parts by mass of the isocyanate group-terminated urethane prepolymer (C). More preferably, in the range of 1.0 to 100 parts by mass, the total number of isocyanate groups in the isocyanate group-terminated urethane prepolymer (C) is preferably in the range of 5 to 100%, more preferably 10 to 100%. The range is reacted with the (meth) acrylic compound (D) having a hydroxyl group.

If the isocyanate group of the isocyanate group-terminated urethane prepolymer (C) is allowed to react with the (meth) acrylic compound (D) having the hydroxyl group within such a range, excellent curability and retention after coating on the substrate are achieved. Performances such as moldability, mechanical strength, durability, and substrate adhesion can be expressed.

The urethane acrylate oligomer (E) has a (meth) acrylic equivalent in the range of 450 to 1100 g / equivalent (hereinafter abbreviated as a unit), preferably in the range of 500 to 900, more preferably in the range of 500 to 750. It is a range. If the (meth) acrylic equivalent of (E) is within such a range, both excellent self-repairing property and good ultraviolet curability can be exhibited.

However, when the (meth) acrylic equivalent of the urethane acrylate oligomer (E) is less than 450, the hardness of the resulting thin film molded article becomes too high, and there is a possibility that self-repairing property will not be exhibited due to insufficient elasticity. is there. Moreover, when the (meth) acrylic equivalent of (E) exceeds 1100, the curing reaction due to ultraviolet irradiation tends to be insufficient, and stickiness may remain on the surface of the thin film molded article, or self-repairability may not be exhibited. There is.

In the present invention, the (meth) acryl equivalent of the urethane acrylate oligomer (E) is a molecular weight per mole of (meth) acryloyl groups, and in the composition, (meth) acryloyl group concentration (mol / g) It is a value represented by the reciprocal of.

The melt viscosity of the urethane acrylate oligomer (E) measured at 50 ° C. according to JIS Z 8803 is preferably in the range of 500 to 200,000 mPa · s, more preferably in the range of 500 to 100,000. If the melt viscosity at 50 ° C. of (E) is within such a range, it is preferable because workability and productivity are improved, the amount of solvent used can be reduced, and the environmental load can be reduced.

Moreover, in this invention, the urethane prepolymer which has an isocyanate group in the unreacted molecular terminal which was not addition-reacted with the (meth) acrylic compound (D) which has the said hydroxyl group, and the molecular terminal which is a product of addition reaction ( A mixture with the urethane acrylate oligomer (E) having a (meth) acryloyl group may be used.

When the isocyanate group-terminated urethane prepolymer (C) and the (meth) acrylic compound (D) having a hydroxyl group are subjected to a urethanation reaction, there may be no catalyst or the presence of a urethanization catalyst, and there is no particular limitation.

When using the urethanization catalyst, it can be added as appropriate at any stage in the initial stage or midway of the urethanization reaction.

As the urethanization catalyst, known catalysts can be used. For example, nitrogen-containing compounds such as triethylamine, triethylenediamine, N-methylmorpholine, or organic metals such as potassium acetate, zinc stearate, stannous octylate, etc. Examples thereof include salts, and organometallic compounds such as dioctyltin dilaurate and dibutyltin dilaurate.

The amount of the urethanization catalyst used is not particularly limited as long as it does not adversely affect the safety during the reaction, the stability of the intermediate or product, the quality, etc.

The urethanization reaction is preferably carried out until the isocyanate equivalent (unit: g / eq, ie g / equivalent) becomes substantially constant.

In addition, after completion of the reaction or in the middle of the reaction, a known catalyst deactivator may be added to deactivate or suppress the activity of the urethanization catalyst, thereby stabilizing the reaction surface, storage surface, quality surface, etc. Good.

(F) Organic solvent having no aromatic skeleton Next, the organic solvent (F) having no aromatic skeleton, which is essential as a diluting solvent in the present invention, will be described below.

In the present invention, by using an organic solvent (F) having no aromatic skeleton, an ultraviolet curable urethane acrylate composition using a conventional photopolymerization initiator can be used without using any photopolymerization initiator. As described above, excellent ultraviolet curability can be imparted, non-yellowing when irradiated with ultraviolet light, and excellent effects such as hardly causing yellowing over time can be exhibited.

In the case of using only an organic solvent having an aromatic skeleton without using a photopolymerization initiator at all, and without using the organic solvent (F) having no aromatic skeleton, ultraviolet curable, yellowing resistance Further, performance such as tack-free on the coated surface cannot be satisfactorily exhibited, and the object of the present invention cannot be achieved.

The organic solvent (F) having no aromatic skeleton used in the present invention is at least one selected from the group consisting of ketone solvents, amide solvents, and alkyl halide solvents.

Examples of the ketone solvent include methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclohexanone, diisobutyl ketone, isophorone, 2,3-hexanedione, 4-methyl-2,3-pentanedione, 5-methyl-2,3-hexanedione. 2,3-pentanedione, 2-hexanone, cycloheptanone, cyclopentanone, 3-decanone, 2-dodecanone, 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol), diacetyl, 2,4 -Dimethyl-3-pentanone, 3,4-dimethyl-1,2-cyclopentanedione, 3,5-dimethyl-1,2-cyclopentanedione, 2-hydroxy-6-isopropyl-3-methyl-2-cyclohex Senon, 4-heptanone, 3-octanone, 3-heptanone, 3 Ethyl-2-hydroxy-2-cyclopentenone, 3-nonanone, 3-hexanone, 1-penten-3-one, 2-heptadecanone, 2,3-heptanedione, 3,4-hexanedione, 6,10, 14-trimethyl-2-pentadecanone, 5-hexen-2-one, 4-hexen-3-one, 1-hexen-3-one, 2-hexylcyclopentanone, 1-hydroxy-2-butanone, 4-hydroxy -2-butanone, 2-hydroxy-2-cyclohexenone, 1-hydroxy-2-heptanone, 3-hydroxy-2-octanone, 2-hydroxy-3,4-dimethyl-2-cyclopentenone, 2-hydroxy- 3-pentanone, 1-hydroxy-4-methyl-2-pentanone, 1-hydroxy-5-methyl-2-hexanone, 3-hydride Xyl-2-pentanone, 6-methyl-3-heptanone, 2-methyl-3- (2-pentenyl) -2-cyclopentenone, 4-isopropyl-2-cyclohexenone, 5-isopropyl-3-nonene-2 , 8-dione, 5-isopropyl-8-methyl-6,8-nonadien-2-one, 3-methyl-2- (cis-2-pentenyl) -2-cyclopentenone, 3-methyl-2- ( trans-2-pentenyl) -2-cyclopentenone, p-menthan-2-one, menthone, 4-methyl-3-penten-2-one, 2-heptanone, 2-nonanone, 2-octanone, methylionone, 5 -Methyl-2-hexanone, 3-methyl-2-butanone, 2-undecanone, 2-decanone, 2-pentanone, 2-tridecanone, 3-buten-2-one, 3 -Methyl-2-cyclopentenone, 6-methyl-2-heptanone, 5-methyl-2-hepten-4-one, 3-methyl-2-hexanone, 3-methyl-2-pentanone, α-methylionone, 3 -Methyl-1,2-cyclohexanedione, 3-methylcyclohexanone, 3-methylcyclopentadecanone, 6-methyl-3,5-heptadien-2-one, 6-methyl-5-hepten-2-one, 3 -Methyl-2,4-nonanedione, 4-nonanone, 3-nonen-2-one, 3,5-octadien-2-one, 1,5-octadien-3-one, 3-octen-2-one, -Octen-3-one, 2-octen-4-one, 4-oxoisophorone, 2-pentadecanone, 3-pentanone, 3-penten-2-one, 4-hydroxyhexane-3- ON, 1- (1-p-Menten-6-yl) -1-propanone, 2-propionylpyrrole, raspberry ketone, 4-tert-butylcyclohexanone, 4-tert-amylcyclohexanone, 2-tetradecanone, tetramethylethylcyclohexenone , 12-tridecene-2-one, 3,5,5-trimethyl-1,2-cyclohexanedione, 1- (2,4,4-trimethyl-2-cyclohexenyl) -trans-2-buten-1-one 2-hydroxy-2,6,6-trimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, 3,3,5-trimethylcyclohexanone, 2,3-undecanedione, 6-hydroxy-5-decanone, berbenone, , 10-Undecen-2-one, 2,2,6-trimethyl-1 4-cyclohexanedione, 2,3-octanedione, 2,5-hexanedione, 2-cyclohexenone, 2-hepten-4-one, 2-hexylidenecyclopentanone, 2-methyl-3-pentanone, 3 , 5,5-trimethyl-4-methylene-2-cyclohexenone, 4- (2,3,6-trimethylphenyl) -3-buten-2-one, 4,5-octanedione, 4,7-dimethyl- 6-octen-3-one, 5,6-decanedione, 5-methyl-5-hexen-2-one, 6-methyl-4,5-heptadien-2-one, 6-hydroxycarbon, 7-octen-2 -One, 8-nonen-2-one, 3-ethyl-2-hydroxy-4-methyl-2-cyclopentenone, 2-hexyl-2-cyclopentenone, 8-hydroxy-4-p- Pentene-3-one, and 5-nonanone, and the like. Among these ketone solvents, methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclohexanone, diisobutyl ketone, and isophorone are preferable because they can exhibit more excellent effects such as ultraviolet curability and yellowing resistance.

Examples of the amide solvent include aliphatic amide solvents such as dimethylformamide, N, N-dimethylacetamide, alkoxy-N-isopropyl-propionamide, and hydroxyalkylamide, or N-methyl-2-pyrrolidone, N- Examples thereof include alicyclic amide solvents such as ethyl-pyrrolidone. Among these amide solvents, dimethylformamide is preferable because it can exhibit more excellent effects such as ultraviolet curability and yellowing resistance.

The halogenated alkyl-based solvent is an organic solvent such as fluorine-based, chlorine-based, bromine-based, and iodine-based solvents, and among them, it is possible to express more excellent effects such as UV curability and yellowing resistance. Chlorinated organic solvents are preferred.

Examples of the chlorinated organic solvent include methylene chloride, chloroform, trichloroethylene, tetrachloroethylene, carbon tetrachloride, 1,2-dichloroethane, 1,1,1-trichloroethane, and preferably methylene chloride and chloroform. .

Among the organic solvents (F), ketone solvents are more preferable because they act more effectively by improving ultraviolet curability and yellowing resistance.

The ultraviolet curable urethane acrylate composition of the present invention is obtained by mixing the urethane acrylate oligomer (E) and the organic solvent (F) having no aromatic skeleton, and the content of the organic solvent (F). Is in the range of 0.2 to 80% by weight.

If the content rate of the organic solvent (F) in the ultraviolet curable urethane acrylate composition of the present invention is within such a range, the ultraviolet curable urethane acrylate composition can be efficiently and normally cured at the time of ultraviolet irradiation. Thus, a flat and beautiful coating can be achieved without causing uneven curing.

For mixing the organic solvent (F) having no aromatic skeleton, a known method may be adopted, and there is no particular limitation.

Commonly used photopolymerization initiators having an aromatic structure (for example, 1-hydroxycyclohexyl phenyl ketone) are decomposed by light absorption of the aromatic structure to generate radicals, and the decomposed photopolymerization initiator is recombined. At that time, it is known that the quinoid structure has a high yellowness.

In the present invention, no photopolymerization initiator is used, and by using an organic solvent (F) having no aromatic skeleton, an ultraviolet curing reaction is allowed to proceed as in the case of using the photopolymerization initiator. However, unlike the case where a photopolymerization initiator is used, a quinoid structure is not formed, so that the cured product is not yellowed, is non-yellowing and has excellent transparency. It is estimated that a coating film etc. can be obtained.

The ultraviolet curable urethane acrylate composition of the present invention is a product of an addition reaction and a urethane prepolymer having an isocyanate group at an unreacted molecular terminal that has not undergone an addition reaction with the (meth) acrylic compound (D) having a hydroxyl group. In the case of a mixture with a urethane acrylate oligomer (E) having a (meth) acryloyl group at the molecular end, the reactivity having a functional group without an aromatic skeleton as a curing agent at any stage of the production process A compound can be blended.

Examples of the curing agent include aliphatic polyols, alicyclic polyols, aliphatic polyamines, and alicyclic polyamines.

The equivalent ratio of the hydroxyl group of the polyol used as the curing agent to the isocyanate group in the ultraviolet curable urethane acrylate composition, that is, the [NCO / OH equivalent ratio] is preferably in the range of 0.7 to 20, more The range is preferably from 0.7 to 10, more preferably from 0.9 to 5.0, and most preferably from 0.9 to 1.1. If the [NCO / OH equivalent ratio] is within such a range, the curing reaction can be efficiently and satisfactorily advanced.

In addition to the urethane acrylate oligomer (E), an acrylic monomer having no aromatic skeleton can be used in the ultraviolet curable urethane acrylate composition of the present invention within a range not departing from the object of the present invention. Examples of the acrylic monomer include (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and sec-butyl (meth) acrylate. , T-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) C1-24 alkyl (meth) acrylate such as acrylate; cycloalkyl (meth) acrylate such as cyclohexyl (meth) acrylate and cyclopentyl (meth) acrylate; dicyclopenta Bridged structures such as ru (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate (Meth) acrylate; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and other hydroxy C2-10 alkyl (meth) acrylate or C2-10 alkanediol mono (meth) acrylate; trifluoro Fluoro C1-10 alkyl (meth) acrylates such as ethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoroisopropyl (meth) acrylate; Alkoxyalkyl (meth) acrylates such as toxiethyl (meth) acrylate; polyalkylene glycol mono (meth) acrylates such as polyethylene glycol mono (meth) acrylate; alkane polyol mono (meth) acrylates such as glycerin mono (meth) acrylate; (Meth) acrylates having amino groups such as dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2-t-butylaminoethyl (meth) acrylate; glycidyl (meth) acrylate, allyl (meth) acrylate Ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-propanediol di (meth) acrylate, 1,4-butanediol di ( Alkanediol di (meth) acrylates such as meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate; alkane polyol di (meth) acrylates such as glycerin di (meth) acrylate; Polyalkylene glycol di (meth) acrylates such as diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate and polypropylene glycol di (meth) acrylate ; Di (meth) acrylates of acid-modified alkane polyols such as fatty acid-modified pentaerythritol; Bridges such as tricyclodecane dimethanol di (meth) acrylate Cyclic di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, di Alkane polyol (meth) acrylates such as pentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate; tri (meth) acrylates of C2-4 alkylene oxide adducts of alkane polyols such as trimethylolpropane and glycerol; And tri (meth) acrylate having a triazine ring such as (2-hydroxyethyl) isocyanurate tri (meth) acrylate. These may be used alone or in combination of two or more.

In addition to the raw materials described above, various additives can be used in the ultraviolet curable urethane acrylate composition of the present invention at any stage of the production process within a range not departing from the object of the present invention.

Examples of such additives include foam stabilizers, antioxidants, defoamers, abrasive grains, fillers, pigments, dyes, colorants, thickeners, surfactants, flame retardants, plasticizers, lubricants, charging agents. Known agents such as an inhibitor, a heat stabilizer, a tackifier, a curing catalyst, a stabilizer, a silane coupling agent, and a wax can be used. Further, as necessary, conventionally known thermoplastic resins, thermosetting resins, and the like can be appropriately selected and used as the blending resin within a range not impairing the object of the present invention. In addition, the said additive is only an example, As long as the objective of this invention is not inhibited, the kind and usage-amount are not specifically limited.

Examples of the tackifier include rosin resins, rosin ester resins, hydrogenated rosin ester resins, terpene resins, terpene phenol resins, hydrogenated terpene resins, and C ₅ aliphatics as petroleum resins. Resins, C ₉ aromatic resins, C ₅ and C ₉ copolymer resins, and the like can be used.

Examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, diisooctyl phthalate, diisodecyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, trioctyl phosphate, epoxy plasticizer, toluene-sulfoamide, chloroparaffin, adipine Acid esters, castor oil, and the like can be used. Examples include methyl acid phosphate (AP-1) and acrylic surface conditioner (BYK-361N).

As the stabilizer, for example, hindered phenol compounds, benzotriazole compounds, hindered amine compounds and the like can be used.

As the filler, for example, silicic acid derivatives, talc, metal powder, calcium carbonate, clay, carbon black and the like can be used.

The ultraviolet curable urethane acrylate composition of the present invention does not use a photopolymerization initiator at all, and can exhibit excellent ultraviolet curability by containing a specific organic solvent as a diluent solvent.

When the ultraviolet curable urethane acrylate composition of the present invention is cured by ultraviolet irradiation, for example, a mercury lamp (low pressure, high pressure, ultrahigh pressure, etc.), hydrogen lamp, deuterium lamp, halogen lamp, xenon lamp, carbon arc lamp. Various light sources such as a fluorescent lamp and a He—Cd laser can be used, and among them, a high-pressure mercury lamp is preferable.

The tan δ peak temperature (loss coefficient peak temperature) measured by dynamic viscoelasticity analysis in accordance with JIS K 0129 using a film prepared according to the method described later using the ultraviolet curable urethane acrylate composition of the present invention is − The range is from 8 to 45 ° C, preferably from -5 to 40 ° C, more preferably from 0 to 35 ° C. If the tan δ peak temperature of the film is within such a range, it is possible to express a function of quickly recovering a scratch once attached and returning it to its original state, that is, excellent self-repairability.

However, when the tan δ peak temperature of the film exceeds 45 ° C., the thin film molded article has poor elasticity, and it may take a long time to recover the scratch, or the scratch once attached may not be sufficiently recovered. On the other hand, if the tan δ peak temperature of the film is less than −8 ° C., the strength of the cured product is insufficient, so that the self-repairing property is insufficient, or the surface of the thin film molded article tends to become sticky. There is a possibility that it cannot be used in contact with the surface.

<Thin film molded body and optical film>
The thin film molded article of the present invention has a cured coating film of the ultraviolet curable urethane acrylate composition on a substrate.

The thin film molded body of the present invention can be obtained by coating the ultraviolet curable urethane acrylate composition on a substrate to form an outermost layer having self-healing properties, and then curing the outermost layer with ultraviolet rays. . The outermost layer can exhibit excellent self-repairing properties, transparency, yellowing resistance, viscoelasticity and other performances.

Although the ultraviolet curable urethane acrylate composition does not contain any photopolymerization initiator, it can exhibit excellent ultraviolet curability by ultraviolet irradiation, and the coating film or cured product obtained can be yellowed over time. Since there is no contamination to contact objects and it has excellent performance such as coating property, moldability, and transparency, for example, in addition to optical members (for example, films and sheets), fibers, coating materials, electronic electrical materials It is useful for a wide range of applications such as food packaging, cosmetic packaging, and decorative films.

In the thin film molded product of the present invention, the thickness of the cured coating film is preferably in the range of 10 to 800 μm.

In the present invention, a member having a thickness of 200 μm or less is defined as a “film” and a member having a thickness exceeding 200 μm is defined as a “sheet” in accordance with a standard generally called in Japan.

Examples of the thin film molded body include self-repairing films, self-repairing paints, light guide films (light guide films), optical films, surface protective films, light guide sheets, and light guide fibers.

The optical film of the present invention is a film having a cured coating film of the ultraviolet curable urethane acrylate composition, and the thickness of the cured coating film is preferably in the range of 10 to 200 μm, more preferably 50 to The total light transmittance measured in accordance with JIS K7361-1 is 92.0% or more in the range of 200 μm. As long as the film thickness and the total light transmittance are within the range, excellent light transmittance can be exhibited. For example, a light guide film (light guide film), an optical film for a flat display panel, an antireflection film (antiglare film) , Anti-glare film), alignment film, polarizing film, polarizing layer protective film, retardation film (optical compensation film), viewing angle improving film (wide view film), brightness improving film, electromagnetic shielding film, light shielding film, specific frequency It can be suitably used for optical materials such as a selective blocking film (transparent radio wave blocking film, infrared blocking film, ultraviolet blocking film), optical low pass filter (OLPF) film, lens filter and the like.

<Manufacturing method of thin film molded body>
As a method for producing the thin film molded body of the present invention, for example, the ultraviolet curable urethane acrylate composition of the present invention is applied onto a release substrate, and after irradiation with ultraviolet rays and curing, it does not have the aromatic skeleton. The organic solvent (F) is volatilized to form a cured coating film, preferably in the range of 10 to 1000 μm, more preferably in the range of 10 to 800 μm, still more preferably in the range of 50 to 800 μm, most preferably in the range of 10 to 200 μm. Examples thereof include a method for obtaining a thin-film molded body (for example, a film, a sheet, etc.) having a small thickness.

Examples of the substrate include metals (plates, foils, etc.), plastics (plates, sheets, films, etc.), papers (release papers, etc.), glass, ceramics, wood plates (decorative plates, etc.), ceramics, cloths, and the like. There is no particular limitation.

When the ultraviolet curable urethane acrylate composition of the present invention is a mixture of the isocyanate group-terminated urethane prepolymer (C) and the urethane acrylate oligomer (E) having a (meth) acryloyl group, as a curing agent in advance, The organic solvent (F) can be volatilized by blending a reactive compound having a functional group having no aromatic skeleton and heating and curing in a range of 80 to 140 ° C., for example.

If an example is shown about the manufacturing method of the thin film molded object of this invention, the manufacturing method containing the series of processes of [the process 1]-[the process 2] as shown below can be mentioned.

[Step 1] Preparation of UV-curable urethane acrylate composition A reaction vessel is charged with a polyol (A) having no molten aromatic skeleton, and stirring is started. Next, a predetermined amount of polyisocyanate (B) having no aromatic skeleton was charged while paying attention to heat generation, the internal temperature was raised to a predetermined temperature, and the mixture was stirred at the temperature for a predetermined time to obtain an isocyanate group-terminated urethane prepolymer. (C) is obtained.
Next, a predetermined amount of a polymerization inhibitor and a (meth) acrylic compound (D) having a hydroxyl group are added and the reaction is continued for a predetermined time, and then the target urethane acrylate oligomer (E) is obtained.
Then, the organic solvent (F) which does not have an aromatic skeleton is added as a dilution solvent, and melt viscosity is adjusted, and the ultraviolet curable urethane acrylate composition of this invention is obtained.

[Step 2] Manufacture of Thin Film Molded Object The target thin film molded body is formed on the polyethylene terephthalate (PET) film subjected to the mold release treatment by the knife coater from the ultraviolet curable urethane acrylate composition obtained in [Step 1]. When the film is a film, it is applied with a thickness of 200 μm or less, or when the thin film molded body is a sheet, it is applied with a thickness exceeding 200 μm. Next, the substrate is cured by irradiating with ultraviolet rays with an ultraviolet irradiation device (for example, a high-pressure mercury lamp) while purging with nitrogen.
Furthermore, the film which is the thin film molded body of the present invention can be obtained by heating and curing at 60 ° C. for a predetermined time to volatilize the organic solvent (F).

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited only to these examples.
In the present invention, “%” is “mass%” unless otherwise specified.
The measurement method and evaluation method used in the present invention are as follows.

[Method for measuring isocyanate equivalent of isocyanate group-terminated urethane prepolymer (C)]
The isocyanate equivalent (unit: g / eq, that is, g / equivalent) of the isocyanate group-terminated urethane prepolymer (C) used in the present invention is a value measured according to JIS K 7301.
Specifically, the obtained urethane prepolymer sample was precisely weighed in an Erlenmeyer flask, dissolved in dry toluene, added with 10 ml of a di-n-butylamine solution, homogenized, and allowed to stand. Quantified by neutralization titration using bromcresol green as an indicator with a standard solution of 5N hydrochloric acid.

[Calculation method of (meth) acryl equivalent of urethane acrylate oligomer (E) having (meth) acryloyl group at the molecular terminal]
The (meth) acrylic equivalent described in the present invention is the molecular weight (g / eq) of the urethane acrylate oligomer (E) that is calculated from the material balance of the raw material and contains 1 mol of (meth) acryloyl groups. In the composition obtained in the comparative example, the value is represented by the reciprocal of the (meth) acryloyl group concentration (mol / g).

[Evaluation method and criteria for UV curability (tack-free)]
The UV curable urethane acrylate compositions obtained in the examples and comparative examples were coated on a polyethylene terephthalate (PET) film subjected to a release treatment with a knife coater to form a coating film, and a high pressure of 120 w / cm mercury lamp 1 lamp, an ultraviolet irradiation apparatus _"N UV irradiation apparatus with _purge conveyor" having a nitrogen purge device light quantity 0.8 J / cm ² at (Co., Ltd. GS Yuasa), under a nitrogen atmosphere (oxygen concentration of 1%) The coating film was cured by irradiating ultraviolet rays under conditions.
Thereafter, the used organic solvent was further volatilized by heating at a temperature of 60 ± 5 ° C. for 10 minutes to obtain a film (thickness of 100 μm) as a thin film molded body having a cured coating film on the substrate.
The presence or absence of stickiness on the surface (outermost layer) of the film was confirmed by touch and evaluated according to the following criteria.
Criteria for UV Curing (Tack Free) ○: No stickiness and excellent UV curability when no liquid adheres to the finger.
X: There is stickiness, and when the liquid adheres to the finger, it is inferior in ultraviolet curability.

[Measurement method of film surface hardness]
Using the films produced in Examples and Comparative Examples, the surface condition of the film in 20 seconds after being damaged with a pencil hardness meter (load 750 g) in a constant temperature and humidity chamber adjusted to an internal temperature of 23 ° C. and a relative humidity of 50%. Was confirmed visually, and the limit pencil hardness at which scratches could not be confirmed was defined as the surface hardness.

[Evaluation method and criteria for film viscoelasticity]
Viscoelasticity was evaluated by measuring tan δ peak temperature (loss coefficient peak temperature) by dynamic viscoelasticity analysis according to JIS K 0129 using the films prepared in Examples and Comparative Examples according to the following procedure.
The compositions obtained in the above Examples and Comparative Examples were coated on a release polyethylene terephthalate plate or polycarbonate plate with a knife coater to form a coating film. Next, the coating film was cured by irradiating the coating film with ultraviolet rays under a nitrogen atmosphere using an ultraviolet irradiator.
Thereafter, the used organic solvent was further volatilized by heating at a temperature of 60 ± 5 ° C. for 10 minutes to obtain a film (thickness of 100 μm) as a thin film molded body having a cured coating film on the substrate.
Using a viscoelasticity spectrometer (model: DMS6100, manufactured by SII Nano Technology Co., Ltd.), the storage elastic modulus (E ′) and loss elastic modulus (E ″) of the film prepared using the composition were Measurement was performed in a tensile mode under conditions of a heating rate of 5 ° C./min and a frequency of 1 Hz. E ′ / E ″ was tan δ, and the temperature at which tan δ was the maximum value was “tan δ peak temperature (° C.)”. The viscoelasticity was evaluated according to
Criteria for judging viscoelasticity of film ○: When tan δ peak temperature is 0 to 35 ° C.
X: When tan-delta peak temperature is less than 0 degreeC or exceeds 35 degreeC.

[Evaluation method and criteria for self-healing of film]
The “self-repairing property” as used in the present invention is a characteristic that a scratch generated on the surface (outermost layer) of a thin film molded body (for example, a film, a sheet, etc.) can be restored over time, and was evaluated and determined by the following method.
In a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and a relative humidity of 50%, immediately after the surface (outermost layer) of the obtained film was scratched with a brass brush weighted to 500 g (straight line 0.1 mm), The recovery time (seconds) until scratches could not be confirmed was measured, and self-repairability was determined according to the following criteria.
Judgment criteria for self-repairability ○: When the recovery time is within 20 seconds, the self-repairability is excellent.
X: When recovery time exceeds 20 seconds, it is inferior to self-repair property.
XX: When not recovering, there is no self-repairing property.

[Evaluation Method and Criteria for Initial Yellowness of Film (YI ₀ )]
The yellow index (YI ₀ ) in the thickness direction of the films produced in Examples and Comparative Examples was measured with a multi-light source spectrocolorimeter (manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS Z8722 and evaluated according to the following criteria. did.
Judgment criteria for initial yellowness ○: When YI _{0 in the} thickness direction is 0.5 or less, the initial yellowness is excellent.
X: When YI _{0 in the} thickness direction exceeds 0.5, the initial yellowness is inferior.

[Evaluation method and criteria for yellowing resistance of film]
Using the film used for the evaluation of the initial yellowness, the film was exposed to 120 ° C. for 72 hours in a dryer, and the yellowness (yellow index: YI ₁ ) after the exposure was measured in accordance with JIS Z8722. It was measured with a colorimeter (manufactured by Suga Test Instruments Co., Ltd.) and evaluated according to the following criteria.
Judgment criteria for yellowing resistance ○: When YI _{1 in the} thickness direction is 0.7 or less, the yellowing resistance is excellent.
×: If the thickness direction YI ₁ exceeds 0.7, less yellowing resistance.

[Film transparency evaluation method and criteria]
The total light transmittance (%) of the films prepared in Examples and Comparative Examples was measured according to JIS K7361-1 using NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd. and evaluated according to the following criteria.
Criteria for transparency ○: When the total light transmittance is 92.0% or more, the transparency is excellent.
X: When the total light transmittance is less than 92.0%, the transparency is poor.

[Synthesis Example 1]
≪Synthesis of urethane acrylate oligomer (E1) having (meth) acryloyl group at molecular end≫
50 parts by mass of polyoxytetramethylene glycol (trade name: PTMG-1000, manufactured by Mitsubishi Chemical Corporation, Mn = 1000) in a molten state at 50 ° C. as a polyol (A) having no aromatic skeleton in a reaction vessel. And stirring was started.
Next, 100 parts by mass of a nurate-modified product (isocyanate equivalent = 204 g / eq) of hexamethylene diisocyanate (hereinafter abbreviated as “HDI”) is added as polyisocyanate (B) having no aromatic skeleton, while paying attention to heat generation. After raising the internal temperature to 85 ° C., the mixture was stirred for 3 hours while maintaining the temperature to obtain a urethane prepolymer (C1) having an isocyanate group at the molecular end.
Further, 57 parts by mass of 4-hydroxybutyl acrylate (hereinafter abbreviated as “4HBA”) as a (meth) acrylic compound (D) having a hydroxyl group was gradually added while paying attention to heat generation and stirred at 85 ° C. for 2 hours. Thus, a urethane acrylate oligomer (E1) was obtained.

[Synthesis Examples 2 to 9]
The same as Synthesis Example 1 except that the types and amounts of the polyol (A), polyisocyanate (B), and (meth) acrylic compound (D) having a hydroxyl group used were changed as shown in Table 1. Under the reaction conditions, urethane acrylate oligomers (E2) to (E9) were obtained.

In addition, the symbol in Table 1 means the following name.
PTMG-1000: Polyoxytetramethylene glycol (Trademark: manufactured by Mitsubishi Chemical Corporation, number average molecular weight 1000)
PCL: polycaprolactone polyol (number average molecular weight 520)
2HEA: 2-hydroxyethyl acrylate 4HBA: 4-hydroxybutyl acrylate HDI: 1,6-hexamethylene diisocyanate H ₁₂ MDI: 4,4'-dicyclohexylmethane diisocyanate IPDI: isophorone diisocyanate MDI: 4,4'-diphenylmethane diisocyanate

[Example 1]
100 parts by mass of the urethane acrylate oligomer (E1) obtained in Synthesis Example 1 and 20 parts by mass of methyl ethyl ketone (hereinafter referred to as “MEK”) as an organic solvent (F) having no aromatic skeleton are weighed in a mixing container. And it mixed until it became uniform at room temperature, and prepared the ultraviolet curable urethane acrylate composition (X1) of this invention.
The ultraviolet curable urethane acrylate composition (X1) prepared above was coated on a polyethylene terephthalate (PET) release film with a knife coater to form a coating film on the outermost layer.
Immediately after coating, a 120w / cm high-pressure mercury lamp and an ultraviolet irradiation device having a nitrogen purging device were irradiated with ultraviolet rays in an irradiation light amount of 0.8 J / cm ^{2 in} a nitrogen atmosphere (oxygen concentration of 1% or less). The film was cured. Furthermore, it heated at 60 degreeC for 10 minute (s) in oven, the organic solvent was volatilized, and the film (P1) (thickness of 100 micrometers) which is a thin film molded object was produced.

[Examples 2 to 9 and Comparative Examples 1 to 10]
The ultraviolet curable urethane acrylate compositions (X2) to (X19) were respectively the same as in Example 1 except that the prepolymer used, the type of organic solvent, and the amount used were changed as shown in Tables 2 and 3. ) To prepare films (P2) to (P19) having a thickness of 100 μm.

In addition, the symbol in Table 2 and Table 3 means the following name.
PTMG-1000: Polyoxytetramethylene glycol (Trademark: manufactured by Mitsubishi Chemical Corporation, number average molecular weight 1000)
PCL: polycaprolactone polyol (number average molecular weight 520)
1,4PBD: 1,4-polybutadienediol (number average molecular weight 1200)
2HEA: 2-hydroxyethyl acrylate 4HBA: 4-hydroxybutyl acrylate HDI: 1,6-hexamethylene diisocyanate H ₁₂ MDI: 4,4'-dicyclohexylmethane diisocyanate IPDI: isophorone diisocyanate MDI: 4,4'-diphenylmethane diisocyanate MEK: methyl ethyl ketone MIBK: methyl isobutyl ketone Irgacure 184: Irgacure 184 (trademark: manufactured by Nagase Sangyo Co., Ltd., radical photopolymerization initiator, chemical name: 1-hydroxy-cyclohexyl-phenyl ketone)

Unlike the conventional ultraviolet curable composition, the ultraviolet curable urethane acrylate composition of the present invention can exhibit excellent ultraviolet curability even if it does not contain any photopolymerization initiator, and the obtained thin film molded article is , Having excellent performance such as self-healing property, yellowing resistance, transparency, and moderate flexibility, for example, optical members (for example, optical films, optical sheets, etc.), optical coating materials, It is useful in a wide range of fields such as textiles, electronic materials, food packages, cosmetic packages, and decorative films.

Claims

For the urethane prepolymer (C) having an isocyanate group at the molecular end obtained by reacting the polyol (A) having no aromatic skeleton with the polyisocyanate (B) having no aromatic skeleton, a hydroxyl group is formed. An ultraviolet curable urethane acrylate composition containing a urethane acrylate oligomer (E) having a (meth) acryloyl group at a molecular end obtained by addition reaction of a (meth) acrylic compound (D) having a ketone solvent, An ultraviolet ray containing 0.2 to 80% by mass of an organic solvent (F) having no at least one aromatic skeleton selected from the group consisting of an amide solvent and an alkyl halide solvent and containing no photopolymerization initiator It is a curable urethane acrylate composition, and the urethane acrylate oligomer (E) has a (meth) acrylic equivalent of 4 The tan δ peak temperature measured by dynamic viscoelasticity analysis in accordance with JIS K 0129 using a film having a thickness of 100 μm prepared from the ultraviolet curable urethane acrylate composition is in the range of 0 to 1100 g / equivalent. An ultraviolet curable urethane acrylate composition having a temperature range of 45 ° C.
The hydroxyl group-containing (meth) acrylic compound (D) is 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, And at least one selected from the group consisting of pentaerythritol triacrylate.
2. The ultraviolet curable urethane acrylate composition according to claim 1, wherein the urethane acrylate oligomer (E) has a melt viscosity at 50 ° C. measured in accordance with JIS Z 8880 in the range of 500 to 100,000 mPa · s.
The ultraviolet curable composition according to claim 1, wherein the organic solvent (F) is at least one selected from the group consisting of methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclohexanone, diisobutyl ketone, isophorone, dimethylformamide, methylene chloride, and chloroform. Urethane acrylate composition.
A thin film molded article comprising a cured coating film of the ultraviolet curable urethane acrylate composition according to any one of claims 1 to 4 on a substrate.
An optical film having a cured coating film of the ultraviolet curable urethane acrylate composition according to any one of claims 1 to 4, wherein the cured coating film has a thickness of 50 to 200 µm in accordance with JIS K7361-1. An optical film having a total light transmittance of 92% or more measured by
A UV curable urethane acrylate composition according to any one of claims 1 to 4 is applied onto a substrate, irradiated with UV, and then the organic solvent (F) is volatilized to form a cured coating film. A method for producing a thin film molded article characterized by comprising: