JP2003342331A - Acrylic syrup resin composition, uv-cured acrylic sheet obtained using the same and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acrylic syrup resin composition which gives a colorless, transparent, flexible and tough cured product under UV irradiation or the like, a colorless, transparent, flexible and tough UV-cured acrylic sheet formed from the syrup resin composition by a casting method or the like under UV irradiation or the like, and its manufacturing method. <P>SOLUTION: The acrylic syrup composition curable under UV irradiation or the like comprises an initial polymer (A), comprising a copolymer of an aliphatic bicyclic monofunctional acrylate monomer and other vinyl monomers, and a (meth)acrylic monomer (B) for dispersing the initial polymer (A), where the glass transition temperature (Tg<SB>1</SB>) of the initial polymer (A) is -5°C or higher, the glass transition temperature (Tg<SB>2</SB>) of a polymer of the (meth)acrylic monomer (B) is -10°C or lower and Tg<SB>1</SB>and Tg<SB>2</SB>satisfy the relation: Tg<SB>1</SB>>Tg<SB>2</SB>. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a UV and / or electron beam curable acrylic syrup resin composition, and more specifically, a sheet-like cured product obtained by subjecting the acrylic syrup resin composition to UV irradiation or the like, The present invention relates to an acrylic syrup resin composition which is a colorless and transparent, flexible and flexible cured product and which is excellent in sheet forming productivity. Further, the present invention, using such an acrylic syrup resin composition,
Method for producing a transparent, colorless, flexible, flexible and tough UV-curable acrylic sheet and UV obtained thereby
It relates to a cured acrylic sheet.

[0002]

2. Description of the Related Art Conventionally, an acrylic resin composition has a cured product formed by curing at a relatively low temperature through a polymerization initiator or under UV irradiation, and has excellent transparency. Since the cured product exhibits excellent adhesiveness to various substrate surfaces, it is a polymer material widely used in various fields as various adhesive sheets, various protective coat films, various adhesives, etc. is there. In addition, the usage form of such a polymer material is from the viewpoint of global environment protection and the working and working environment of its handling, in particular, the form before curing is used as a solvent-free or non-solvent type polymer material. There is.

[0003] For example, in JP-A-62-45606, a UV-curable resin composition is used in order to improve the adhesion to a substrate, for example, a reactive base polymer such as oligoester acrylate is added with isovol. A UV-curable resin composition is described which is a solventless type in which nyloxyethyl (meth) acrylate is used in place of a conventional reactive diluent, and the cured product thereof has adhesiveness. A resin composition that is used as a protective coating agent for various substrate surfaces using such a solventless UV curable resin composition, and as such a resin composition, a reaction of a prepolymer A base resin containing isobornyloxymethyl (meth) acrylate is disclosed. In addition, it is described that this isobornyloxymethyl (meth) acrylate is used for the purpose of functioning to prevent a decrease in the curing rate of an acrylic resin system under UV curing and to impart adhesion to a substrate surface. There is.

Further, JP-A-5-202316 discloses a solvent-free solvent containing isobornyl (meth) acrylate as a protective coating agent obtained by polymerizing a UV-curable base resin composition and having excellent adhesion and scratch resistance. UV of mold
Curable resin compositions have been proposed. Such isobornyl (meth) acrylate is described as being used for adjusting the viscosity and introducing a hydrophobic structure in such a coating agent. In addition, JP-A-1-30841
No. 8 discloses a UV-curable resin composition containing an acrylated urethane oligomer and an aliphatic bicyclic monofunctional acrylate monomer such as isobornyl (meth) acrylate, and other monomers.

Further, Japanese Patent Laid-Open No. 2000-34453 discloses a syrup-like composition containing substantially no solvent but a radically polymerizable acrylic vinyl monomer.
A method for producing a solventless acrylic adhesive sheet that is heated to 60 ° C. or higher after coating has been proposed. That is,
The solvent-free coating polymerization syrup composition is (meth)
It is described that the composition is a syrup-like composition containing a partial polymer of an acrylic acid alkyl ester or a syrupy composition containing a partial polymer of a (meth) acrylic acid alkyl ester, a functional group-containing monomer, and another vinyl monomer. Has been done. In addition, examples of the radically polymerizable acrylic vinyl monomer that constitutes these compositions include butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, (Meth) acrylic acid, itaconic acid, maleic acid, methyl (meth) acrylate, ethyl (meth) acrylate, isobornyl (meth) acrylate and the like are described.

[0006]

Under the circumstances as described above, as described in the above-mentioned publication examples, conventionally, the acrylic polymer is excellent in transparency, which is a characteristic of the acrylic polymer,
In particular, it relates to a polymer material having an adhesive property and is widely used as various adhesive sheets through an acrylic syrup-like resin composition as a form of use thereof, a protective coat film material and the like. Moreover, as disclosed in the above-mentioned publication examples, as radical-polymerizable acrylic vinyl monomers constituting the syrup-like resin composition, although the purpose of action relating to each is different, the monomer species constituting the resin composition In particular, isobornyl (meth) acrylate, which is an aliphatic bicyclic monofunctional acrylate monomer, is often used.

Further, in Japanese Patent Laid-Open No. 62-456064, Japanese Patent Laid-Open No. 5-202316, and Japanese Patent Laid-Open No. 1-308418, there is a particular relation with respect to the adhesion of the coating resin composition to a substrate and its adhesion. A solvent-free protective coating agent containing isobornyl (meth) acrylate as a constituent monomer of the composition for adjusting the viscosity of the resin composition and for the surface adhesion of the cured product to the surface to be adhered. UV curable resin compositions for use have been proposed.

Further, when preparing such acrylic adhesives, coating agents, sheets, etc., it has been a conventional finding that the acrylic monomer constituting these polymers is added to the glass transition temperature of the homopolymer. (Tg ° C.) is usually dealt with as an adhesive monomer and a non-adhesive monomer. Therefore, when polymerizing (or coating molding) an acrylic sheet (or film) under heat curing and / or UV irradiation curing, a syrup-like resin composition, which is a starting material before curing, is conventionally used. In order to prepare it, it is extremely important to prepare it after it is known whether the polymer of the monomer species is a monomer exhibiting tackiness or whether the polymer is a monomer exhibiting non-tackiness.

Therefore, when a syrup-like acrylic resin composition excellent in handling property and productivity is used as a starting material, it can be formed into a sheet when it is coated and molded on an industrial scale. The process must not impair the transparency, which is an excellent property of acrylic polymers as described above. In addition, [raw material supply-polymerization curing-sheet formation]
The actual process is a continuous process, and the productivity should not be impaired due to the tackiness that the acrylic polymer tends to exhibit during this continuous process. Further, conventionally, the acrylic sheet to be coated and molded is still sufficiently practical for its transparency, flexibility, flexibility (stretchability) and toughness (tensile strength). The reality is that the required sheet properties have not been reached.

Therefore, an object of the present invention is to apply a syrup-shaped acrylic resin composition as a starting material in a sheet-like coating molding (polymerization curing) while casting the syrup-shaped acrylic resin composition on a substrate surface under UV irradiation. It is an object of the present invention to provide an acrylic syrup resin composition which enables an acrylic sheet having transparent, flexible, flexible and tough sheet characteristics without impairing its productivity.

Another object of the present invention is to use such an acrylic syrup resin composition, under UV irradiation, for the polymerization rate and the casting rate in the casting direction, and the casting rate. Manufacturing method that enables industrial production of a UV-curable acrylic sheet while preventing the occurrence of flexure, dullness, etc. on the sheet formed in relation to the polymerization rate, and a UV-curable acrylic obtained by this manufacturing method Is to provide a sheet.

[0012]

Means for Solving the Problems The present inventor has conducted extensive studies to solve the above-mentioned problems, and in order to cure and form a cast syrup-like resin composition into a sheet under UV irradiation, in particular, an adhesive monomer. A syrup-like resin composition was prepared by paying attention to the glass transition temperature (Tg ° C.) of the non-adhesive monomer. Moreover, when a syrup-shaped resin composition was prepared by focusing on the speed of polymerization of monomers in the composition and the coating speed (productivity) of sheet formation, it was clear that it was transparent and flexible. The present invention has been completed by finding a syrup-like resin composition capable of preparing a sheet having a tough sheet property at a coating / sheeting speed that enables actual production.

That is, according to the present invention, a syrup-like resin composition capable of forming a polymerized cured product under UV irradiation and / or electron beam irradiation is used as an aliphatic bicyclic monofunctional acrylate monomer. , An initial polymer (A) composed of a copolymer with another vinyl monomer, and a (meth) acrylic monomer (B) in which the initial polymer (A) is dispersed.
An acrylic syrup resin composition comprising:

The glass transition point of the prepolymer (A) constituting the acrylic syrup resin composition according to the present invention is (T
g ₁ ). Further, the glass transition point of the polymer of the (meth) acrylic monomer (B) is (Tg ₂ ).
Is. These glass transition temperatures (Tg ₁ , Tg ₂ ) ° C
In relation to the above, both of the prepolymer (A) and the (meth) acrylic monomer (B) forming the acrylic syrup resin composition according to the present invention always have the following relational expression (1).
The acrylic syrup resin composition is characterized by being contained in combination so as to satisfy the relationship represented by.

[Equation 3] That is, the combination satisfying the above relational expression (1) is
(I) Within the range of Tg ₁ ≧ 40 ° C., Tg ₂ ≦ −40
(Ii) 40 ° C.> Tg ₁ ≧ 25 ° C., −30 ° C. ≦ Tg ₂ <−40 ° C., (iii) 25 ° C.> Tg ₁ ≧ 10 ° C. In the range
-20 ° C ≤ Tg ₂ <-30 ° C, and (iv) 1
In the range of 0 ° C.> Tg ₁ ≧ −5 ° C., −10 ° C. ≦ Tg
It is an acrylic syrup resin composition contained in a combination within the range of ₂ <−20 ° C.

Further, when the acrylic syrup resin composition according to the present invention is formed into a sheet, it is characterized in that it is prepared by a one-step process in which the constituent monomers are partially polymerized due to its cost performance. It is a syrup-like resin composition. In addition, a sheet obtained by polymerizing such an acrylic syrup resin composition under UV irradiation and / or electron beam irradiation has a colorless, transparent, flexible and tough sheet property. A method for producing a characteristic UV-curable acrylic sheet is provided.

That is, an aliphatic bicyclic monofunctional acrylate monomer is copolymerized with another vinyl monomer, and an initial polymer (Ag) having a glass transition point of (Tg ₁ ) is expressed on a weight basis. ) Is prepared in the range of 30 to 50%. Next, the prepolymer (A) thus prepared has a glass transition point (Tg
₂ ), the (meth) acrylic monomer (B) is 50
A syrup-like resin composition is prepared by dispersing the syrup-like resin composition in a monomer so as to be in the range of 70%. Both the prepolymer (A) and the (meth) acrylic monomer (B) contained in the syrup-like resin composition thus prepared satisfy the relation expressed by the following relational expression (4). To be prepared.

[Equation 4] That is, in the relational expression (1), (i) Tg₁≧ 40 ℃
In the box, Tg_Two≦ −40 ° C., (ii)
40 ° C> Tg₁Within the range of ≧ 25 ° C., −30 ° C. ≦ T
g_Two<Iii) 25 ° C> Tg in the range of -40 ° C
₁Within the range of ≧ 10 ° C., −20 ° C. ≦ Tg_Two<-30
In the range of ℃, (iv) 10 ℃> Tg ₁≧ -5 ° C
In the box, -10 ° C ≤ Tg_Two<-20 ° C range
It Then, 100 of the acrylic syrup resin composition
0.01 to 2.0 parts by weight of the photopolymerization initiator
After adding within the range, mix and defoam to remove the photopolymerizable activator.
A ril syrup resin composition (C) is prepared. Then
Peel off this photopolymerizable acrylic syrup resin composition (C)
While casting on a predetermined treated substrate, a predetermined UV
Polymerized and cured into a sheet by irradiation and / or electron beam irradiation
To produce a UV curable acrylic sheet.

(Operation) From the above, the syrup according to the present invention
The acrylic resin composition in the shape of,
A specific monomer, an aliphatic bicyclic monofunctional acrylate
Rate monomer] and another vinyl monomer
Glass transition point (Tg₁) Is a prepolymer
(A) is a glass transition point when polymerized by post-polymerization
But (Tg_Two ) Identifying (meth) acrylic monomers
-Dispersed in (B) and prepared as a syrup-like resin composition
Has been done. Also, books with such compositional characteristics
The syrup-like resin composition according to the invention is capable of being exposed to UV rays under the irradiation
In the actual process of converting the initial polymer (A)
As a tacky component, it is also post-polymerized during this sheeting process.
(Meth) acrylic monomer (B) is used as an adhesive component
Syrupy tree with physical properties that interact with each other
It is a fat composition. Moreover, in the present invention,
Syrup-like resin composition having various compositional or physical properties
The actual process of turning materials into sheets is
Allow (cast on a specified substrate) ⇒ Under UV irradiation ⇒
 Sheet-shaped curing] Raw material casting / UV polymerization curing
-It is a continuous series of steps to form a sheet. This series of
In the step, the syrup-like resin composition according to the present invention,
Prepolymer (A) and (meth) acrylic monomer (B)
The glass transition point [Tg₁, T
g_Two] Depending on the temperature, it is easy (Tg₁)> (T
g_Two) Relationship can be satisfied, the monomer polymerization
Appropriate speed and sheet coating speed (productivity)
The actual process of sheet formation can be performed appropriately while making adjustments.
You can

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an acrylic syrup resin composition according to the present invention, a UV curable acrylic sheet using the same, and a method for producing the same will be described below.
This will be described below.

As already mentioned above, the UV curing according to the invention
The syrup-shaped acrylic resin composition has a
A certain monomer [aliphatic bicyclic monofunctional acrylate
Of a vinyl monomer] and another vinyl monomer.
The glass transition point is (Tg₁), And preferred
-5 ° C or higher, particularly preferably -5 to + 40 ° C.
Initial polymerization by partially polymerizing monomers in a certain range
It is the thing (A). In addition, the initial polymer (A) is dispersed.
To form a syrup-like resin composition (meta)
The curly monomer (B) is post-polymerized to form a polymer.
When the glass transition point is (Tg_Two), And preferred
-10 ° C or less, particularly preferably -10 to -40 ° C.
It is a specific monomer in a specific range. Also, this
Sheet from the syrup resin composition of
When it is converted, this prepolymer (A) is non-adhesive
It is contained as an ingredient. Further, in the present invention,
(Meth) acrylic monomer that is post-polymerized in the sheeting process
-(B) is contained as an adhesive component. like this
Actual process of forming a sheet using a simple syrup resin composition
Is a series of continuous casting of raw materials, UV polymerization and curing into sheets.
It is carried out as a matter of course. As already mentioned above, syrup-shaped trees
Prepolymers (A) and (meth) acrylates that make up the fat composition
The combination of these with the glass-based monomer (B)
Transition point [(Tg ₁), (Tg_Two)] C
(Tg₁)> (Tg_Two) By satisfying the relationship
This series of steps in the invention is related to the fast polymerization rate of the monomer.
And sheet coating speed (or productivity)
UV curable acrylic siro
Resin composition.

As a result, the acrylic sheet formed into a sheet using the UV-curable acrylic syrup resin composition according to the present invention is colorless and transparent, has flexibility, and has toughness. It can be easily understood from the fact that it is in good agreement with the facts of the embodiments described later.

Therefore, in the present invention, as the specific monomer for forming the above-mentioned prepolymer (A), for example, an aliphatic bicyclic monofunctional acrylate monomer can be mentioned. Among them, in the present invention, it is preferable. , Isobornyl acrylate can be suitably used as appropriate.

Therefore, in the present invention, the prepolymer (A) is preferably obtained by copolymerizing the aliphatic bicyclic monofunctional acrylate monomer with another vinyl monomer for the reason already described above. It is a thing. If another monomer species is selected and prepared so that the glass transition point (Tg ₁ ) of the copolymer is in the range of −5 ° C. or higher, the monomer species to be copolymerized can be used without particular limitation. In the present invention, examples of such monomer species include (meth) acrylic acid alkyl esters, (meth) acrylic acid annealing esters, (meth) acrylic acid alkoxyalkyls, polyvalent acrylic acid esters,
Methacrylic acid esters of alicyclic alcohols, epoxy group-containing vinyl monomers, unsaturated carboxylic acids or partial ester compounds and their anhydrides, amide group-containing vinyl monomers, organosilicon group-containing vinyl compound monomers, etc. Is mentioned. Furthermore, in the present invention, from the viewpoints of being relatively inexpensive as a raw material, having many monomer species, and easily controlling properties such as strength to desired values, (meth) acrylic acid alkyl ester is preferable. , Or (meth) acrylic acid alkyl ester as a main component, and at least one kind of other acrylic monomers can be used in an appropriate suitable combination. When other monomers are used in combination with the (meth) acrylic acid alkyl ester, the ratio of the combination is usually 100 parts by weight of the (meth) acrylic acid alkyl ester with respect to other acrylics. At least one kind of the system monomers can be appropriately used within the range of 10 to 100 parts by weight. The prepolymer (A) having (Tg ₁ ) as described above is a combination with the (meth) acrylic monomer (B) that always satisfies the relationship of (Tg ₁ )> (Tg ₂ ). The prepolymer (A) characterized in that the weight average molecular weight (Mw) is preferably in the range of 10,000 to 500,000. If this (Mw) is less than the lower limit, the toughness is particularly impaired, and it is far from practical use as a sheet. On the other hand, if this (Mw) exceeds the upper limit, the castability is impaired due to high viscosity. However, it is not preferable because the handling of the sheet is reduced.

Examples of these acrylic monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylate. ) Isobutyl acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate,
Lauryl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, phenyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate , Acrylic acid alkyl esters such as propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate, dialkylaminoalkyl (meth) acrylates such as diethylaminoethyl (meth) acrylate, (meth) (Meth) acrylamides such as acrylamide, N-methylol (meth) acrylamide and diacetone acrylamide, epoxy group-containing (meth) acrylic acid esters such as glycidyl (meth) acrylate, and cycloaliphatic acetic acid such as cyclohexyl (meth) acrylate. Kohl's acrylic ester, ethylene glycol di (meth) acrylic ester, diethyl glycol di (meth) acrylic ester, triethylene glycol di (meth) acrylic ester, polyethylene glycol di (meth) acrylic ester , Di (meth) acrylic acid ester of dipropylene glycol, di (meth) acrylic acid ester of tripropylene glycol, etc., and di (meth) acrylic acid ester of (poly) alkylene glycol.

Examples of the fluorine-substituted acrylic monomer include trifluoromethyl methyl (meth) acrylate, 2-trifluoromethyl ethyl (meth) acrylate, and 2-perfluoromethyl (meth) acrylate. Ethyl, 2-pa-fluoroethyl-2-pa-fluorobutylethyl (meth) acrylate, 2-pa-fluoroethyl (meth) acrylate, perfluoromethyl (meth) acrylate, (meth) acryl Examples thereof include fluorine-substituted (meth) acrylic acid-based monomers such as acid dipa-fluoromethylmethyl.

Examples of the styrene-based monomer include alkyls such as styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene and octylstyrene. Styrene, fluorostyrene,
Chlorostyrene, bromostyrene, dibromostyrene,
Halogenated styrene such as chloromethylstyrene, nitrostyrene, acetylstyrene, methoxystyrene, α-
Methylstyrene, vinyltoluene, etc. can be mentioned.

As other polymerizable monomers, for example, fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene and vinylidene fluoride,
Silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane, vinyl acetate, vinyl propionate, vinyl n-butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl persate, vinyl laurate, Vinyl stearate, vinyl benzoate, pt-butyl vinyl benzoate, vinyl esters such as vinyl salicylate, vinylidene chloride, vinyl chlorohexanecarboxylate, and (meth) acrylic acid-2-
Examples thereof include chloroethyl and 2-chloroethyl methacrylate. When an organic polymer is produced by using such other monomer in combination, the amount of these other monomers is usually 1 to 100 parts by weight per 100 parts by weight of the acrylic monomer as long as the characteristics of the acrylic polymer are not impaired.
It may be used in an amount of not more than 00 parts by weight, preferably in the range of 0.1 to 50 parts by weight.

Further, as a monomer having a functional group, if necessary, for example, acrylic acid, methacrylic acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornene dicarboxylic acid,
Unsaturated carboxylic acids such as bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic acid are mentioned, and as their derivatives, maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydro. Phthalic anhydride, bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic acid anhydride, or, for example, aminoethyl (meth) acrylate, propylaminoethyl (meth) acrylate, (meth ) Alkyl ester derivatives of (meth) acrylic acid such as dimethylaminoethyl acrylate, aminopropyl (meth) acrylate, phenylaminoethyl (meth) acrylate, cyclohexylaminoethyl (meth) acrylate, N-vinyldiethylamine , N-acetylvinylamine and other vinylamine derivatives, allylamine, methacrylamine , N-methylacrylamine and other allylamine derivatives, N, N-dimethylacrylamide, N, N-dimethylaminopropylacrylamide, acrylamide, N-methylacrylamide and other acrylamide derivatives, p-aminostyrene and other aminostyrenes, 6-aminohexyl succinimide, 2-
A monomer having an amino group-containing ethylenically unsaturated bond such as aminoethyl succinimide can be suitably used.

In the present invention, it is not always necessary to form a crosslinked structure, but it can be formed by introducing a crosslinked structure if necessary. In order to form such a crosslinked structure, a polyfunctional monomer having a functionality of 2 or more can be suitably used. As the polyfunctional monomer, for example, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, Neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,1,1-trishydroxymethylethane diacrylate, 1,1,1-trishydroxymethylethanetri Acrylate, 1,1,1-
Trishydroxymethylpropane triacrylate, N
-Methylol acrylic amide and the like can be mentioned. Further, such a polyfunctional monomer is usually used in an amount of 0.5 parts by weight based on 100 parts by weight of the above-mentioned polymerizable monomer.
-50 parts by weight, preferably 1-15 parts by weight can be appropriately used. If necessary, for example, styrene, α-methylstyrene, chlorostyrene,
Methylstyrene, vinyltoluene, divinylbenzene,
Examples include vinyltoluene, methyl methacrylate, methyl acrylate, ethyl acrylate, vinyl acetate, and diacrylic phthalate. These may be used alone or in combination of two or more.

The (meth) acrylic monomer (B) used in the present invention is, for the reasons already described above,
The glass transition point (Tg ₂ ) of the polymer is −
It is 10 ° C. or lower, preferably in the range of −10 to −40 ° C., and this (Tg ₂ ) is always (Tg ₁ )> (T
Specific monomer species satisfying the relationship of g ₂ ) can be used by appropriately selecting from the above-mentioned (meth) acrylic monomers.

Therefore, such an initial polymerization compound (A) is used.
A UV-curable acrylic syrup resin composition according to the present invention, which comprises a (meth) acrylic monomer (B) and a (meth) acrylic monomer (B) as constituents, has a prepolymer (A) having the above-mentioned compositional and physical characteristics. , Expressed on a weight basis, preferably, from the viewpoint of desired toughness in sheet formation, expression of non-adhesiveness and handleability at the time of cast coating, etc.,
The prepolymer (A) can be appropriately prepared so as to be contained in the range of 30 to 60%. If the content is 30% or less of the lower limit, it becomes difficult to adjust the adhesiveness of the monomer (B), and the so-called (Tg ₁ )> (T
It is not preferable because it makes the relationship of g ₂ ) difficult and, on the other hand, when it exceeds 60% of the upper limit, it becomes a high degree of polymerization, and cast coating property and handling property are remarkably impaired.

The (meth) acrylic monomer (B) which disperses the prepolymer (A) to form a syrup-like resin composition is expressed in the syrup-like resin composition on a weight basis. In particular, from the viewpoint of desired toughness in sheet formation, development of non-adhesiveness, handleability at the time of cast coating, etc., preferably 40 to 7
It can be appropriately suitably prepared so as to contain it in the range of 0%. If the content is less than 40% of the lower limit value, it is not preferable because the viscosity is increased and the castability is deteriorated. On the other hand, if it exceeds 70% of the upper limit value, the tackiness is exhibited and It is not preferable because it is far from the non-adhesive sheet which is the object of the invention.

The acrylic syrup resin composition according to the present invention prepared as described above is polymerized and formed into a sheet under UV irradiation so that it is colorless and transparent and has flexibility.
A method for producing a UV-curable acrylic sheet that exhibits toughness will be described below. That is, in terms of weight, an aliphatic bicyclic monofunctional acrylate monomer is partially copolymerized with an essential monomer and another monomer, and the glass transition point (Tg ₁ ) is in the range of -5 ° C or higher. To prepare the prepolymer (A). In order to obtain a syrup having a dispersion concentration of the initial polymer (A) in the range of 30 to 50%, a glass transition point (T
A syrup having a (meth) acrylic monomer (B) in which g ₂ ) is in the range of −10 ° C. or less is in the range of 50 to 70% is prepared. As already described above, in the syrup thus prepared, it is important that the relationship (Tg ₁ )> (Tg ₂ ) is satisfied.

Both are contained in the syrup-like resin composition thus prepared, and they are prepared in combination so as to satisfy the relationship represented by the following relational expression (1).

[Equation 5] In the relational expression (1), (i) Tg ₁ ≧ 40 ° C., Tg ₂ ≦ −40 ° C., and (ii) 40
In the range of ℃> Tg ₁ ≧ 25 ℃, -30 ℃ ≦ Tg ₂
Within the range of <-40 ° C, (iii) 25 ° C> Tg ₁ ≧
In the range of 10 ° C., -20 ° C. ≦ Tg ₂ <−30 ° C., and (iv) 10 ° C.> Tg ₁ ≧ −5 ° C., −10 ° C. ≦ Tg ₂ <−20 ° C. .

Then, the acrylic syrup composition 10
The photopolymerization initiator is added to 0 part by weight in the range of 0.01 to 2.0 parts by weight, preferably 0.05 to 0.10 part by weight, and then added by a commonly known method. A photopolymerizable acrylic syrup resin composition (C) is prepared by mixing and defoaming. Then, this acrylic syrup resin composition (C)
UV while casting on a predetermined substrate that has been subjected to peeling treatment.
It can be polymerized and cured under irradiation to form a sheet-shaped acrylic cured body. As a result, the sheet thickness is 10 μm to 10 mm, depending on the UV irradiation intensity and the irradiation amount.
The sheet can be appropriately and suitably prepared, and in particular, a sheet having a wall thickness of 1 mm or more, which cannot be obtained by the conventional solvent type, can be appropriately and suitably prepared.

As the photopolymerization initiator, conventionally known acetophenones: for example, acetophenone, 2,
2-diethoxyacetophenone, p-dimethylaminoacetophenone, methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-
2-Cyclohexylacetophenone and ketones: for example, benzophenone, 2-chlorobenzophenone, p,
p'-dichlorobenzophenone, p, p'-bisdiethylaminobenzophenone, N, N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2- Propyl)
Ketones and benzoin ethers: for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl methyl ketal, benzoyl benzoate, α-acyloxime ester, thioxanthones, etc. As a UV sensitizer, n-butylamine, triethylamine, tri-n-butylphosphine or the like can be added depending on the case.

In order to partially polymerize the above-mentioned monomers to prepare the initial polymerization product (A), a thermal decomposition type polymerization initiator can be used, and if necessary, a photopolymerization initiator is added. Can be used. Therefore, examples of the thermal decomposition type polymerization initiator include organic peroxides, organic hydroperoxides, organic peroxyketals, and azo compounds. Organic peroxides: For example,
Dicumyl peroxide, di-tert-butyl peroxide, tert-butyl cumyl peroxide, dilauroyl peroxide, dibenzoyl peroxide, diacetyl peroxide, didecanoyl peroxide, diisonononayl peroxide, 2-methylpenta Noyl peroxide and organic hydroperoxides: for example, tert-butyl hydroperoxide, cumyl hydroperoxide, 2,5-dimethyl-2,5-dihydroperoxyhexane, p-methane hydroperoxide, Diisopropylbenzene hydroperoxide, and organic peroxyketals: for example, 1,1-bis (tert-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,
1-bis (tert-hexylperoxy) cyclohexane, 1,1-bis (tert-butylperoxy)
3,3,5-Trimethylcyclohexane, and azo compounds: for example, 2,2'-azobisisobutyronitrile, 2,
2'-azobis-2,4-dimethylvaleronitrile, 2,2'-azobiscyclohexylnitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2-phenylazo-4-methoxy-2,4- Dimethylvaleronitrile, dimethyl-2,2'-
Examples include azobisisobutyrate. These polymerization initiators can be used alone, but usually, two or more kinds of them can be used in combination in order to improve various properties of the molded product. In the present invention, 0.1 to 100 parts by weight of the total amount of the polymerizable monomer mixed with the other monomer to be copolymerized with the aliphatic bicyclic monofunctional acrylate monomer is 100 parts by weight.
It can be used in the range of 4 parts by weight.

Further, in the present invention, in addition to the above-described monomer species, from the viewpoint of improving the sheet characteristics in actual use as a sheet material, etc., from the viewpoint of the purpose of the present invention, there is a conventional Various generally known additives can be added. For example, a polymerization initiator, a polymerization inhibitor, a curing accelerator, a low shrinkage agent, a thickener, an internal mold release agent, a dispersant, a plasticizer, a lubricant, a film forming aid, a release agent, a defoaming agent, and heat resistance imparting. Agents, flame retarding agents, antistatic agents, surfactants, conductivity imparting agents, UV sensitizers, antifogging agents, antibacterial / antifungal agents, photocatalysts, fillers, dyes, pigments, fiber reinforcements, etc. Can be appropriately used as necessary. In the present invention, these additives may be blended individually, or may be appropriately blended in combination of two or more types from the handling property of blending. It can be appropriately mixed and dispersed in advance in the monomer for preparing the polymer (A) or in the (meth) acrylic monomer (B) in which the prepolymer (A) is dispersed.
Among the above-mentioned additives, for example, various fine powders, scales, etc. are involved in improving / reinforcing the tensile strength of the sheet material, preventing bending, and improving properties such as AB (anti-blocking) property of the sheet surface. , Fibrous (or whisker-like) inorganic
An organic filler can be added as appropriate. Examples of such a filler include calcium carbonate, magnesium carbonate, barium sulfate, aluminum hydroxide, magnesium hydroxide, alumina powder, silica, synthetic smectite, synthetic zeolite, magnesium titanate, synthetic basic lithium carbonate / aluminum salt, synthetic Examples thereof include basic lithium carbonate / magnesium carbonate, synthetic calcium silicate, synthetic magnesium silicate, orastonite, nepheline site, talc, diatomaceous earth, mica, glass powder and various organic polymer fine particles. These can be used alone or in combination of two or more. In addition, in particular, the particle size and the like, since it does not reduce the transparency of the sheet,
The refractive index is selected and used after consideration. Examples of the fiber reinforcing material include glass fiber, carbon fiber, organic fiber, potassium titanate fiber, and the like, and the fiber length thereof is 1 to 20 mm, preferably 3 to 10 mm. In addition, these fine powder, fibrous filler,
From the viewpoint of compatibility and dispersibility with the syrup resin composition of the present invention, for example, a surface treatment with a silane-based or titanate-based coupling agent or the like is performed in advance, or a suitable dispersant is used in combination. Can be used.

[0038]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

<Molecular weight>: It is a weight average molecular weight (Mw) determined by GPC (gel permeation chromatography). GPC has a column with GMH-H manufactured by Tosoh Corporation.
T and GMH-HTL were used, and orthodichlorobenzene was used as a solvent. <Light transmittance>: The light transmittance is measured by Shimadzu (manufactured by)
UV-1600 spectrophotometer was used. <Non-adhesiveness>: 23 ° C / by probe tack tester
The lobe tack value of 65% RH (standard state described in JIS Z0237 method) is 10 g / 5 mmφ or less. <Toughness>: The tensile strength according to the tensile test method for the plastic film and sheet of JIS K7127 is
It has a range of 100 to 200 Kg / cm ² . <Flexibility>: Stretching rate according to JIS K7127 method is 10
A range of 0 to 400% is shown. <Flexibility>: The degree of occurrence of cracks and cracks when a weight of about 500 g is dropped and the degree of occurrence of cracks and breakage during 180 ° rapid bending are evaluated.

(Example 1) <Preparation of acrylic syrup composition according to the present invention> In a round-bottomed flask having a capacity of 2 L equipped with a condenser, a nitrogen gas introducing tube, a thermometer, and a stirrer, 2-ethylhexyl acrylate (hereinafter, 2EHA), 450 g of isobornyl acrylate (hereinafter referred to as iBoA), 100 g of acrylic acid (hereinafter referred to as AA), and 1.5 g of n-dodecyl mercaptan (hereinafter referred to as nDMP), After purging with nitrogen, the temperature was raised to 60 ° C. Then, 2,2-azobis (4-methoxy) manufactured by Wako Pure Chemical Industries, Ltd. was used as a polymerization initiator.
0.025 g of -2,4-dimethylvaleronitrile (hereinafter referred to as V-70) was added with stirring, and the reaction system was heated to about 125 ° C as the polymerization reaction progressed. Then
After the temperature dropped to 120 ° C, 2EHA 112.5
g, iBoA 112.5 g, AA 25 g, nDMP
Of 0.75 g was added and rapidly cooled to cool the reaction system to 60 ° C., and then the temperature was 60 ° C. × 0.5 hr under a nitrogen purge.
It was stirred. Next, V-70 (0.05 g) was added with stirring, and when the reaction system temperature was raised to 120 ° C. and then dropped to about 115 ° C., 2EHA (112.5 g), iBoA
112.5 g of AA and 25 g of AA are added and rapidly cooled,
An acrylic syrup composition (A) according to the present invention was prepared. The obtained syrup composition (A) had a monomer concentration of 50% as the (meth) acrylic monomer (B) in which the prepolymer (A) was dispersed and a polymer concentration of 50 as the prepolymer (A). %, The polymer component Mw of the prepolymer (A) was 100,000.

<Preparation of Acrylic Sheet Using Acrylic Syrup Composition of the Present Invention> Obtained Syrup Composition (A)
25 parts by weight of 2EHA, 0.5 parts by weight of trimethylolpropane triacrylate (hereinafter referred to as TMP-A) manufactured by Kyoeisha Chemical Co., Ltd. 2-Hydroxy-2-
Methyl-1-phenyl-propan-1-one (hereinafter, I-1
173), and mixed and defoamed to prepare a photopolymerizable syrup resin composition (A-1). Next, 0.5 m of this syrup composition (A-1) was applied to a 100 μm-thick PET separator subjected to a double-sided peeling treatment.
It was applied in a thickness of m and peeled on both sides of the coating layer.
A PET separator having a thickness of μm was attached. Next, a colorless transparent sheet was prepared by irradiating light of 5.0 mW with black light for 10 minutes. PE from the obtained sheet
The acrylic sheet A-1 from which the T separator has been peeled off is a UV-curable acrylic sheet according to the present invention, in which Tg ₁ = −
A sheet having a probe tack value of 6 at 3 ° C and Tg ₂ = -29 ° C, a transparent sheet having a visible light transmittance of 92%, and a tough sheet having a tensile strength of 195 Kg / cm ^2. The sheet was a flexible sheet having a stretch ratio of 350% and excellent flexibility.

(Example 2) In the production of the sheet in Example 1, 25 parts by weight of 2EHA, 16.6 parts by weight of 2EHA, and 8. of MA were added to 100 parts by weight of the syrup resin composition (A). If we add 25 parts by weight to 4 parts by weight,
Tg ₂ = −20 ° C., and similarly, Tg ₁ > Tg ₂ was satisfied, and the obtained UV curable acrylic sheet was a colorless and transparent sheet having good flexibility.

Comparative Examples 1 to 3 In Comparative Example 1, Example 2
Tg ₂ = + 1.0 ° C. to make 25 parts by weight of 2EHA in 25 parts by weight of MA, and Tg ₁ <Tg ₂ , and in Comparative Example 2, 25 parts by weight of 2EHA in Example 2 was added to 2EHA. 11.25 parts by weight of iBoA
11.25 parts by weight of AA and 0.25 parts by weight of AA
₂ = −3 ° C., Tg ₁ = Tg ₂ , and
In Comparative Example 3, 25 parts by weight of 2EHA in Example 2 is changed to 25 parts by weight of iBoA. Tg ₂ = + 22.9 ° C., Tg ₁ <Tg _2, and all the obtained sheets are bent. When the cracks are generated, the flexibility is remarkably reduced.

(Comparative Example 4) In Example 1, the total amount of iBoA in the preparation of the acrylic syrup composition was 2%.
When substituting the _EHA, prepared as an adhesive composition Tg 1 = -60 ℃, in relation to Tg _2, Tg 1> Tg ₂
It became extremely difficult to prepare a composition satisfying the above condition, and it was difficult to prepare the sheet intended by the present application.

(Comparative Examples 5 and 6) In Comparative Example 5, iBoA alone was used as the initial polymer (A) at the time of preparation of the acrylic syrup composition in Example 1, and 2EH was used as the postpolymer (B).
Sheeted as A alone. Further, in Comparative Example 6, 2EHA alone was used as the prepolymer (A) and iBoA was used alone as the postpolymer (B) to form a sheet. As a result, although Comparative Example 5 is a composition satisfying Tg ₁ > Tg ₂ ,
If the compatibility between the prepolymer (A) and the disperse monomer is reduced and a sheet is formed, dullness occurs and the transparency of the sheet is reduced. In Comparative Example 6, the composition was Tg ₁ <Tg ₂ and was a sheet far from the sheet intended by the present invention.

From the above, in the present invention, the syrup-forming prepolymer is a copolymer of iBoA and a dispersing monomer, and further, Tg ₁ relating to the prepolymer and Tg ₂ relating to the dispersing monomer. In the relationship Tg ₁ > Tg
It is well understood that it is extremely important to have an acrylic syrup composition satisfying ₂ .

[0047]

As described above, according to the present invention, the prepolymer which is dispersed in the monomer forming the syrup-like resin composition has a specific content of an aliphatic bicyclic monofunctional acrylate monomer such as iBoA. (Tg ₁ ) is a copolymer having a range of −5 ° C. or higher, and a dispersion monomer that disperses the copolymer to form an acrylic syrup has a glass transition point (Tg ₂₎ as a polymer that is post-polymerized during sheet formation. ) Is in the range of -10 ° C or lower, and the composition as the acrylic syrup resin composition satisfies the relationship of (Tg ₁ )> (Tg ₂ ) as a balance between the non-adhesive component and the adhesive component. It is a UV-curable acrylic syrup resin composition. By using such an acrylic syrup resin composition, for example, a UV-curing acrylic sheet that is colorless and transparent, is flexible, is flexible, and exhibits toughness by being polymerized to form a sheet under UV irradiation. It is possible to provide a sheet having a high productivity and a wall thickness of 1 mm or more, which cannot be obtained by the conventional solvent type.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F071 AA33X AA77 AA86 AF14                       AF26 AF30 AG02 AG14 AG15                       BA02 BB02 BB12 BC01                 4J011 AA05 PA69 PB22 PC02 QA03                       UA01 UA03 VA01 VA10 WA06                 4J026 AA45 BA27 BB02 BB07 DA05                       DB12 DB15 DB36 FA04 GA06                 4J100 AB02Q AB03Q AB04Q AB07Q                       AC04Q AC24Q AC26Q AC27Q                       AG02Q AG04Q AG27Q AG33Q                       AJ01Q AJ02Q AJ08Q AJ09Q                       AJ10Q AK31Q AK32Q AK33Q                       AL03Q AL04Q AL05Q AL08P                       AL08Q AL62Q AL66Q AL67Q                       AM15Q AM19Q AM21Q AM42Q                       AN02Q AN03Q AP16Q BA02Q                       BA03Q BA04Q BA08Q BA10Q                       BA14Q BA29Q BA30Q BA31Q                       BA41Q BB01Q BB03Q BB07Q                       BB10Q BB12Q BC04Q BC08P                       BC43Q BC54Q DA25 EA06                       JA01 JA03 JA05

Claims (8)

[Claims] 1. An acrylic syrup resin composition for forming a polymerized cured product under UV irradiation and / or electron beam irradiation, which is a copolymer of an aliphatic bicyclic monofunctional acrylate monomer and another vinyl monomer. Prepolymer (A) consisting of
And a (meth) acrylic monomer (B) in which the prepolymer (A) is dispersed, and the prepolymer (Gg) having a glass transition point (Tg ₁ ) in the acrylic syrup resin composition ( A) and the above-mentioned (meth) in which the glass transition point related to the polymer is (Tg ₂ ).
The following relational expression (1) is given in combination with the acrylic monomer (B). An acrylic syrup resin composition characterized by being combined so as to satisfy the relationship represented by. 2. The acrylic syrup resin composition according to claim 1, wherein the aliphatic bicyclic monofunctional acrylate monomer is isobornyl acrylate. 3. The acrylic syrup resin composition contains the initial polymer (A) in an amount of 30 to 50% by weight and the (meth) acrylic monomer (B) in an amount of 50 to 70% by weight.
The acrylic syrup resin composition according to claim 1 or 2, wherein the acrylic syrup resin composition is contained in the range of. 4. The acrylic syrup resin composition according to claim 1, wherein the weight average molecular weight of the initial polymer (A) is 10,000 to 500,000. 5. A colorless and transparent flexible, flexible polymer obtained by polymerizing the acrylic syrup resin composition according to claim 1 to form a sheet under UV irradiation. A UV curable acrylic sheet characterized by being tough. 6. A UV-curable, colorless and transparent flexible, flexible and tough resin obtained by polymerizing an acrylic syrup resin composition obtained by partially polymerizing a monomer into a sheet under UV irradiation. In the method for producing an acrylic sheet, a glass transition point of a copolymer of an aliphatic bicyclic monofunctional acrylate monomer and another vinyl monomer is (T
g ₁ ), the prepolymer (A) is prepared, and the prepolymer (A) is 30 to 50 in terms of weight.
%, The glass transition point of the polymer (Tg
₂ ), the (meth) acrylic monomer (B) is 50
To 70%, and the prepolymer (A) is used.
And the (meth) acrylic monomer (B) in combination are represented by the following relational expression (1) The acrylic syrup resin composition is prepared so as to satisfy the relationship represented by, and then a photopolymerization initiator is added in an amount of 0.01 to 2.0 parts by weight in 100 parts by weight of the acrylic syrup resin composition. Then, the mixture is mixed and defoamed to prepare a photopolymerizable acrylic syrup resin composition (C), and then the acrylic syrup resin composition (C) is placed on a predetermined base material subjected to a peeling treatment. A method for producing a UV-curable acrylic sheet, which comprises polymerizing and curing under UV irradiation while casting to form a sheet-shaped acrylic cured body. 7. The method for producing a UV-curable acrylic sheet according to claim 6, wherein the aliphatic bicyclic monofunctional acrylate monomer is isobornyl acrylate. 8. A colorless and transparent flexible, flexible, and tough UV formed by using the method for producing a UV-curable acrylic sheet according to claim 6 or 7.
Curable acrylic sheet.