JPH0733832A - Photopolymerizable composition and production of viscoelastic product - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing a specific acrylate-based monomer, a specified monoethylenically unsaturated compound, a specific alicyclic saturated hydrocarbon resin and a specified photopolymerization initiator in a specific proportion, excellent in tack strength and holding power at high temperatures and useful as a tacky tape, etc. CONSTITUTION:This composition contains 100 pts.wt. monomer principal component composed of (A) 60-99wt.% one or more acrylate-based monomers selected from the group consisting of alkyl (meth)acrylates of an alkyl alcohol having a 1-14C alkyl group and (B) 1-40wt.% monoethylenically unsaturated compound copolymerizable with the component (A) such as methacrylic acid, (C) 0.5-30 pts.wt. alicyclic saturated hydrocarbon resin and (D) 0.001-5 pts.wt. photopolymerization initiator such as 4-(2-hydroxyethoxy)phenyl (2-hydroxy-2-propyl) ketone. Furthermore, a substrate is coated or impregnated with this composition and then irradiated with light to afford a viscoelastic product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acrylate-based photopolymerizable composition, and more specifically, a photopolymerizable composition exhibiting high performance even under a rapid reaction condition and a viscoelasticity obtained by the composition. It relates to a method of manufacturing a product.

[0002]

2. Description of the Related Art Recently, a pressure-sensitive adhesive having a strong adhesiveness and a high holding power for a variety of coated steel plates, those having a surface with a large number of irregularities, polyolefin plates, etc. The demand for is increasing. In response to such a demand, conventionally, in a solvent-based pressure-sensitive adhesive produced by thermally polymerizing an acrylic monomer, it is known to add a tackifier to enhance its adhesive force. .

However, for example, in a photopolymerization method in which an acrylic monomer composition is applied to a substrate and then irradiated with light to be polymerized, when tackifier is added to the composition, the tackiness increases, but the composition Since it has poor compatibility with and remains as a non-crosslinked portion after completion of the polymerization, it has a drawback that the high temperature holding power is lowered, or bleed out from the polymer after the polymerization, and the adhesive strength at the adhesive interface is lowered.

Further, there are drawbacks that the reaction time is delayed and the molecular weight of the produced polymer is lowered due to the inhibition of the polymerization of the tackifier, so that sufficient adhesive performance cannot be obtained.

Therefore, as a tackifier with less polymerization inhibition, for example, a method of adding an aliphatic polymer is disclosed in JP-A-64-66280, and a method of adding a hydrogenated rosin ester is disclosed in JP-A-2-18485. And Japanese Patent Laid-Open No. 2-107686. Also,
JP-A-4-320471 discloses a photopolymerizable adhesive composition containing a phenol-modified rosin-based tackifier.

However, by the addition of the above-mentioned tackifier, a high-speed reaction system (polymerization is completed within 2 minutes)
It has been confirmed that, since the polymerization reaction is inhibited, the reaction is delayed and the molecular weight is lowered. Therefore, the molecular weight of the obtained polymer is lower than the target, and the high temperature holding power is lowered. In order to obtain the desired high temperature holding power, it is necessary to make the molecular structure of the polymer have a high degree of cross-linking, but the high degree of cross-linking reduces the elongation of the obtained polymer and reduces the adhesive strength. there were.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and its object is to provide a photopolymerizable composition and a photopolymerizable composition which maintain a high level of tackiness and high temperature holding power. It is an object of the present invention to provide a method for producing a viscoelastic product by a legal method under high-speed reaction conditions.

[0008]

The photopolymerizable composition of the first invention is at least selected from the group consisting of (a) (meth) acrylic acid alkyl ester of alkyl alcohol having an alkyl group having 1 to 14 carbon atoms. A monomer main component 100 comprising 60 to 99% by weight of one or more acrylate-based monomers and (b) 1 to 40% by weight of a monoethylenically unsaturated compound copolymerizable with the acrylate-based monomer.
By weight, (c) 0.5 to 30 parts by weight of the alicyclic saturated hydrocarbon resin and (d) 0.001 to 5 parts by weight of a photopolymerization initiator are contained.

The photopolymerizable composition of the second invention comprises at least one acrylate-based monomer selected from the group consisting of (a) (meth) acrylic acid ester of alkyl alcohol having an alkyl group having 1 to 14 carbon atoms. 60-99
% By weight and (b) 1 to 40% by weight of a monoethylenically unsaturated compound copolymerizable with the acrylate monomer, 100 parts by weight of a monomer main component, (e) a terpene phenol-based tackifying resin or a coumarone-based adhesive Addition resin 0.5 to 40 parts by weight and (d) photopolymerization initiator 0.00
It is characterized by containing 1 to 5 parts by weight.

The photopolymerizable composition of the third invention comprises at least one acrylate-based compound selected from the group consisting of (a) (meth) acrylic acid alkyl ester of alkyl alcohol having an alkyl group having 1 to 14 carbon atoms. Monomer 6
100 parts by weight of a monomer main component consisting of 0 to 99% by weight and (b) 1 to 40% by weight of a monoethylenically unsaturated compound copolymerizable with the acrylate-based monomer, (c) an alicyclic saturated hydrocarbon resin And (g) a xylene resin (0.5 to 40 parts by weight), and (d) a photopolymerization initiator (0.001 to 5 parts by weight).

The photopolymerizable composition of the fourth invention comprises at least one acrylate-based monomer selected from the group consisting of (a) (meth) acrylic acid ester of an alkyl alcohol having an alkyl group having 1 to 14 carbon atoms. 60-99
% By weight and (b) 1 to 40% by weight of a monoethylenically unsaturated compound copolymerizable with the acrylate-based monomer, 100 parts by weight of a monomer main component, and (h) a weight average molecular weight measured by GPC of 5000 or more. 1 to 50 parts by weight of a polyfunctional vinyl compound and (d) a photopolymerization initiator 0.001
It is characterized by containing ~ 5 parts by weight. The method for producing a viscoelastic product of the fifth invention is characterized in that the substrate is coated or impregnated with the photopolymerizable composition according to any one of the first to fourth inventions, and then the substrate is irradiated with light. From the above, the above object is achieved.

The first invention will be described in detail below.
The monomer main component used in the first invention is 60 to 99 wt% of at least one acrylate-based monomer (a) selected from (meth) acrylic acid alkyl ester,
It is composed of 40 to 1% by weight of a monoethylenically unsaturated compound (b) copolymerizable with the acrylate-based monomer.

As the acrylate-based monomer (a), a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 14 carbon atoms, preferably an alkyl group having 4 to 12 carbon atoms is used. Examples of the monomer include n-butyl (meth) acrylate,
2-Ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isobornyl (meth) acrylate, etc. are mentioned. These acrylate-based monomers (a) can be used alone or in combination of two or more.

In order to impart a good balance of tackiness and cohesiveness to the polymer obtained from the photopolymerizable composition of the first invention, an acrylic acid alkyl ester having a homopolymer glass transition point of -50 ° C. or lower is usually used. A monoethylenically unsaturated compound (b) is used as a main component and as a comonomer.

As the monoethylenically unsaturated compound (b) copolymerizable with the acrylate-based monomer (a),
For example, methacrylic acid, acrylamide, (meth) acrylonitrile, N-substituted acrylamide, hydroxyethyl (meth) acrylate, N-vinylpyrrolidone, maleic acid, itaconic acid, N-methylolacrylamide, carboxyethyl (meth) acrylate are representative. Examples thereof include monofunctional acrylic acid esters having a higher boiling point than acrylic acid and having a carboxyl group.

Further, among the above-mentioned monoethylenically unsaturated compounds (b), particularly preferable are high-boiling point carboxyl group-containing (meth) acrylic acid alkyl esters,
The following are commercially available products.

(1) Carboxyethyl acrylate (“β-CEA” manufactured by Daicel UCB), carboxyalkyl acrylate represented by carboxypropyl acrylate, etc. (2) β-acryloxyethyl hydrogen phthalate (manufactured by Shin-Nakamura Chemical Co., Ltd. NK ester ACB-100 ") (3) β-acryloxypropyl hydrogen phthalate (" NK ester ACB-200 "manufactured by Shin Nakamura Chemical Co., Ltd.) (4) β-acryloxyethyl hydrogen succinate (manufactured by Shin Nakamura Chemical Co., Ltd. (NK ester A-SA)) (5) β-methacryloxyethyl hydrogen phthalate (“NK ester CB-1” manufactured by Shin-Nakamura Chemical Co., Ltd.) (6) β-methacryloxyethyl hydrogen succinate (Shin Nakamura Chemical Co., Ltd. (“NK Ester SA”) (7) ω-carboxypolycaprolactone monoa Relate (manufactured by Toagosei Co., Ltd. "M-5300") (8) acrylic acid oligomer _{CH 2 = CHCOO- (CH 2 CH} 2 COO) n -H
(However, n> 1) (“A-5600” manufactured by Toagosei Co., Ltd., n≈
1.4) (9) β-acryloxyethyl hexahydrophthalate (“HOA-HH” manufactured by Kyoeisha Yushi Co., Ltd.)

In addition to the above, N-vinylcaprolactam typified by N-vinylpyrrolidone is particularly preferable because of its high boiling point. These monomers have the property of accelerating the polymerization reaction by themselves and having a small effect of decreasing the molecular weight during the accelerating reaction. Further, since it has a high boiling point, it has been confirmed that in photopolymerization in an inert gas such as N ₂ gas, there is little adverse effect such as a decrease in polar groups due to evaporation of monomers.

Further, as the monoethylenically unsaturated compound (b), a vinyl type monomer forming a polymer having a low glass transition point, for example, tetrahydrofurfuryl acrylate, polyethylene glycol acrylate, polypropylene glycol acrylate, fluorine acrylate, silicon acrylate. Etc. can also be used.

The acrylate-based monomer (a) and the monoethylenically unsaturated compound (b) are contained in an amount of 40 to 1% by weight of the ethylenically unsaturated compound (b) based on 60 to 99% by weight of the acrylate-based monomer (a). Is compounded in. When the content of the ethylenically unsaturated compound (b) exceeds 40% by weight,
It is not preferable because the adhesive property of the polymer is deteriorated.

The alicyclic saturated hydrocarbon resin (c) used in the first invention is a tackifier (tackifier), and has a high level in the polymer obtained from the photopolymerizable composition of the first invention. It is used to give adhesive strength.

Commercially available products of the above alicyclic saturated hydrocarbon resin (c) are, for example, "Arcon P-" manufactured by Arakawa Chemical Industry Co., Ltd.
70 "," Arcon P-90 "," Arcon P-10 "
0 "," Arcon P-115 "," Arcon P-12 "
5 "," Arcon P-140 "(trade name), etc .;" Rigalite R-90 "," Rigalite R-100 "," Rigalite R-125 "(tradename) manufactured by Rika Hercules Co., Ltd.
Etc .; "Escorets 5300 series", "Escorets ECR-229D", "Escorets ECR-228B", "Escorets ECR-" manufactured by Tonex.
143H ”,“ Escorets ECR-327 ”(trade name) and the like.

When the content of the alicyclic saturated hydrocarbon resin (c) is small, there is no effect of improving the adhesive strength of the polymer, and when the content is large, the compatibility is deteriorated and separation occurs. 0.5 to 100 parts by weight
Limited to ~ 30 parts by weight. The alicyclic saturated hydrocarbon resin (c) is preferably dissolved in advance in the monomer main component in order to impart a high level of tackiness to the polymer.

Such an alicyclic saturated hydrocarbon resin (c)
By using, under high-speed reaction conditions, polymerization inhibition does not occur, it is possible to increase the molecular weight of the polymer, and even for polyolefin substrates such as polyethylene and polypropylene while maintaining a high level of high temperature retention. Demonstrate strong adhesion.

Conventionally, the addition of tackifier is
It is known to have the effect of increasing the glass transition point of the polymer and reduce the low temperature initial adhesiveness of pressure sensitive adhesives, etc.
It has been found that the alicyclic saturated hydrocarbon resin (c) in the present invention does not have such a phenomenon and has an effect of improving the initial adhesive force at low temperature.

Photopolymerization initiator (d) used in the first invention
Examples include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone [Ciba Geigy, trade name "Darocur 2959"], 1-
Hydroxycyclohexyl phenyl ketone [Ciba Geigy, trade name "Irgacure 184"], 2-hydroxy-2,2-dimethylacetophenone [Ciba Geigy, trade name "Darocur 1173"], methoxyacetophenone, 2,2-dimethoxy-2 -Acetophenone initiators such as phenylacetophenone; Benzoin ether initiators such as benzoin ethyl ether and benzoin isopropyl ether; Ketal initiators such as benzyl dimethyl ketal; Others, halogenated ketones, acyl phosphinoxides, acyl phosphates And so on.

When the content of the photopolymerization initiator (d) in the photopolymerizable composition of the first invention is reduced, the photopolymerization initiator (d) is reduced.
Is consumed in the initial polymerization due to the light energy, so that unreacted monomers are likely to remain, and not only the monomer odor remains in the obtained polymer but also the cohesive force is lowered. Further, when the content of the photopolymerization initiator (d) increases, the polymerization reaction rate increases, but the residual odor accompanying the decomposition of the photopolymerization initiator (d) becomes intense, and the variation in the molecular weight of the obtained polymer is Since it becomes large and the adhesive performance is deteriorated, it is limited to 0.001 to 5 parts by weight with respect to 100 parts by weight of the monomer main component.

In order to impart heat resistance and cohesive force at high temperature to the photopolymerizable composition of the first invention, it is preferable to add a polymerizable crosslinking agent. Examples of such a polymerizable cross-linking agent include butanediol di (meth) acrylate,
Hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane Examples thereof include tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate and urethane acrylate.

When the content of the polymerizable cross-linking agent increases, it becomes difficult to control the degree of cross-linking. Therefore, it is preferably 5 parts by weight or less with respect to 100 parts by weight of the main monomer component. Addition of the above-mentioned polymerizable cross-linking agent causes cross-linking between polymer molecules in the course of the photopolymerization reaction, and as a result, the heat resistance of the polymer is improved, and the cohesive force and holding power at high temperature are improved. Further, it is preferable that the polymerizable cross-linking agent is added after partially polymerizing the photopolymerizable composition to increase the viscosity.

If necessary, a thickener, a thixotropic agent, a filler, a filler and the like may be added to the above-mentioned photopolymerizable composition as long as the photopolymerizability is not impaired. Examples of the thickener include acrylic rubber, epichlorohydrin rubber, isoprene rubber, butyl rubber, and the like, and examples of thixotropic agents include colloidal silica, polyvinylpyrrolidone, and the like. Examples of the filler include calcium carbonate, titanium oxide, clay, and the like, and examples of the filler include glass balloon,
Inorganic hollow bodies such as alumina balloons and ceramic balloons; organic hollow bodies such as vinylidene chloride balloons and acrylic balloons; organic spherical bodies such as nylon beads, acrylic beads, silicon beads; single fibers such as polyester, rayon, nylon; polyethylene, polypropylene And the like.

Next, the second invention will be described. The photopolymerizable composition used in the second invention is (a) an acrylate-based monomer and (b) a monomer main component composed of a monoethylenically unsaturated compound, (e) a terpene-phenol-based tackifying resin or a coumarone-based tackifying resin. It contains a resin and (d) a photopolymerization initiator.

The above-mentioned monomer main component may be the same as the monomer main component used in the first invention.

The tackifying resin (e) is contained in order to impart a high level of tackiness, has relatively little polymerization inhibition,
A terpene phenol-based tackifying resin or a coumarone-based tackifying resin is selected as one exhibiting good tackiness properties even under a high-speed reaction condition in which the polymerization is substantially completed in an irradiation time of 2 minutes or less. Examples of commercially available terpene phenol-based tackifying resins include “YS Polystar TH-130” and “YS Polystar TH-10” manufactured by Yasuhara Chemical Co., Ltd.
0 ”(trade name) and the like.

Examples of the coumarone-based tackifying resin include coumarone resin, indene resin, coumarone-indene copolymer, copolymer of coumarone and / or indene and vinyl monomer (for example, coumarone-indene). -Styrene copolymer) and the like.

Examples of commercially available products of the above-mentioned coumarone tackifying resin include "Escrystal A-1" manufactured by Nippon Steel Chemical Co., Ltd.
00 "," Es Crystal A-120 "," Es Crystal A-100S "," Es Crystal A-120S "
(Product name) and the like.

The above-mentioned terpene phenol-based tackifying resin and coumarone-based tackifying resin have almost no inhibition of polymerization under high-speed reaction conditions, and therefore can have a high molecular weight, and can maintain a high temperature holding power and have a low energy surface. It also exhibits high adhesion to certain polyolefin (polyethylene, polypropylene, etc.) substrates. Further, the terpene phenol resin and the coumarone resin have good compatibility with the acrylic copolymer, bleeding out with time does not reduce the adhesive strength, and the obtained adhesive has good transparency. Will be things.

Further, if the hydrogenation rate of the unsaturated bond in the terpene phenol-based tackifying resin and the coumarone-based tackifying resin decreases, the polymerization inhibition increases.
It is preferably 0% or more, more preferably 95% or more, still more preferably 98% or more.

If the amount of the tackifying resin (e) is too large, the sol content in the adhesive becomes too large, which adversely affects the holding power at high temperature.
It is preferably 40 parts by weight or less with respect to 00 parts by weight.

The photopolymerization initiator (d) may be the same as the photopolymerization initiator used in the first invention.

The above photopolymerizable composition preferably contains a polymerizable crosslinking agent in order to impart heat resistance and cohesive force at high temperature. As such a polymerizable crosslinking agent, the same polymerizable crosslinking agent as used in the first invention can be used.

If necessary, the above-mentioned photopolymerizable composition may contain a thickener similar to that of the first invention, as long as the photopolymerizability is not impaired.
A thixotropic agent, a filler, a filler and the like may be added.

Next, the third invention will be described. The photopolymerizable composition used in the third invention is (a) an acrylate-based monomer and (b) a monomer main component composed of a monoethylenically unsaturated compound, (c) an alicyclic saturated hydrocarbon resin, and (g). It contains a tackifying resin composed of a xylene resin and (d) a photopolymerization initiator.

As the monomer main component, the same monomer main component used in the first invention can be used. In addition,
Examples of the monoethylenically unsaturated compound (b) which is one of the constituents of the monomer main component include acrylic acid in addition to those exemplified in the description of the first invention.

The tackifying resin composed of the alicyclic saturated hydrocarbon resin (c) and the xylene resin (g) increases the adhesive strength of the resulting adhesive to a low energy surface,
It is contained in order to reduce the deterioration of high temperature holding power and to improve the long-term adhesiveness to a curved surface of polyolefin. Incidentally, the long-term adhesiveness to a polyolefin curved surface is the adhesiveness of a pressure-sensitive adhesive to a curved surface made of a polyolefin, and the test method is one in which a pressure-sensitive adhesive layer to be tested is attached to an aluminum plate, After sticking on a fixed curved surface made of polyolefin, it is a method of measuring the number of days until the pressure-sensitive adhesive layer is peeled off from the polyolefin surface by the repulsive force of the aluminum plate (this measurement method is described later in the section of performance evaluation). Shown in detail).

The alicyclic saturated hydrocarbon resin (c) is preferably a C5 or C9 petroleum resin having a hydrogenation rate of 98% or more, and examples of commercially available products thereof are described in the section of the first invention. Any of the ones listed are used.

The above-mentioned xylene resin (g) is a light yellow transparent starch syrup resin obtained by reacting meta-xylene and formalin under a strong acid catalyst like a xylene-formaldehyde resin. Also included are various modified xylene formaldehyde resins modified with phenols such as alkylphenols, carboxylic acids, amines and alcohols. The xylene resin (g) preferably has a hydrogenation ratio of 90% or more to the unsaturated bond in the xylene resin, more preferably 95% or more, and further preferably 98% or more. Is.

If the hydrogenation rate to the unsaturated bond in the tackifying resin is less than 90%, the possibility of polymerization inhibition or the like increases, and it may not be suitable under high speed reaction conditions. Further, in this case, it may be copolymerized in the produced polymer at the time of polymerization and the effect as the tackifying resin may not be exhibited.

Commercially available products of the above xylene resin (g) include, for example, "Nicanol HP-1" manufactured by Mitsubishi Gas Chemical Company.
50 "," nicanol GHP-160 "," nicanol HP-120 "," nicanol HP-100 "," nicanol HP-210 "," nicanol HP-70 "(trade name) and the like.

The content ratio of the xylene resin (g) in the tackifying resin is preferably 5 to 80% by weight, more preferably 10 to 60% by weight, still more preferably 20 to 50% by weight.

When the content of the tackifying resin is small, there is no effect of improving the adhesive strength of the polymer, and when the content is large, the tackifying resin remains as a non-crosslinking component in the adhesive, so that the sol content is too large and the temperature is high. Since it adversely affects the cohesive force at 0.degree.
It is limited to 5 to 40 parts by weight.

The above tackifying resin is preferably dissolved in the monomer main component in advance in order to impart a high level of tackiness to the polymer.

By using the tackifying resin composed of the above alicyclic saturated hydrocarbon resin (c) and xylene resin (g), polymerization inhibition does not occur under high-speed reaction conditions, so that the polymer is A high molecular weight is possible, and it is strong against polyolefin substrates such as polyethylene and polypropylene, which have a low energy surface while maintaining a high level of high temperature holding power, and against other highly polar adherends. Can maintain adhesiveness. Further, the long-term adhesiveness to a polyolefin curved surface is improved.

The photopolymerization initiator (d) may be the same as the photopolymerization initiator used in the first invention.

The photopolymerizable composition preferably contains a polymerizable crosslinking agent in order to impart heat resistance and cohesive force at high temperature. As such a polymerizable crosslinking agent, the same polymerizable crosslinking agent as used in the first invention can be used.

If necessary, the above-mentioned photopolymerizable composition contains a thickener similar to that of the first invention, as long as the photopolymerizability is not impaired.
A thixotropic agent, a filler, a filler and the like may be added.

Next, the fourth invention will be described. The photopolymerizable composition used in the fourth invention is (a) a monomer main component composed of an acrylate-based monomer and (b) a monoethylenically unsaturated compound, and (h) a weight average molecular weight measured by GPC of 5000 or more. Functional vinyl compound and (d)
It contains a photopolymerization initiator.

As the above-mentioned monomer main component, the same one as the monomer main component used in the first invention can be used. In addition,
Examples of the monoethylenically unsaturated compound (b) which is one of the constituents of the monomer main component include acrylic acid in addition to those exemplified in the description of the first invention.

The weight average molecular weight measured by GPC is 5
The polyfunctional vinyl compound (h) of 000 or more is contained in order to crosslink the produced polymers of the obtained pressure-sensitive adhesive and improve the cohesive force. As a cross-linking agent, a weight average molecular weight of 50
When only a polyfunctional vinyl compound having a weight average molecular weight of less than 00 is contained, the cohesive force is improved and the flexibility of the produced polymer is lowered, but the polyfunctional vinyl compound having a weight average molecular weight of 5000 or more is contained. In addition, the cohesive force is improved and the distance between the cross-linking points between the produced polymers is increased, so that the flexibility of the produced polymer is also improved. Therefore,
While maintaining a high level of holding power at high temperature, it is possible to maintain strong adhesion to a low energy surface polyolefin substrate such as polyethylene or polypropylene, or to other adherends with high polarity. Further, the long-term adhesiveness to a polyolefin curved surface is improved.

As the above polyfunctional vinyl compound (h),
As the commercially available product, for example, “U” manufactured by Shin Nakamura Chemical Co., Ltd.
NI TACK K-100 "(weight average molecular weight by GPC measurement: about 20,000)," UNI TACK UA-8 "
000 "(weight average molecular weight measured by GPC: about 1.6
10,000), "UNI TACK UA-4000" (GPC
Weight average molecular weight measured: about 80,000) (trade name) and the like.

When the content of the polyfunctional vinyl compound (h) is small, there is no effect of improving the cohesive force of the polymer,
Since the flexibility decreases as the content increases, it is limited to 1 to 50 parts by weight with respect to 100 parts by weight of the monomer main component.

The polyfunctional vinyl compound (h) is
It is preferably added after the photopolymerizable composition is partially polymerized and thickened.

Further, in the photopolymerizable composition of the fourth invention,
As the crosslinking agent, a polyfunctional vinyl compound having a weight average molecular weight of less than 5000 as described in the section of the description of the first invention may be contained.

The photopolymerization initiator (d) may be the same as the photopolymerization initiator used in the first invention.

If necessary, the above-mentioned photopolymerizable composition contains a thickener similar to that of the first invention, as long as the photopolymerizability is not impaired.
A thixotropic agent, a filler, a filler and the like may be added.

Further, the above photopolymerizable composition may contain a tackifying resin in order to give a high level of tackiness. Examples of such tackifying resins include rosin resins, modified rosin resins (hydrogenated rosin resins, polymerized rosin resins, etc.), terpene resins, terpene phenol resins, aromatic modified terpene resins, C5 and C9 resins, coumarone. Examples of the resin include a tackifier resin composed of the alicyclic saturated hydrocarbon resin (c) and the xylene resin (g) described in the third invention, relative to 100 parts by weight of the monomer main component. , 0.5 to 40 parts by weight is preferable. By containing the tackifying resin composed of the alicyclic saturated hydrocarbon resin (c) and the xylene resin (g), the obtained adhesive has low energy while maintaining an even higher level of high temperature holding power. Strong adhesion can be maintained not only to the surface of the polyolefin substrate such as polyethylene or polypropylene, but also to other highly polar adherends, and the long-term adhesion to polyolefin curved surface is further improved. In this case, the tackifying resin composed of the alicyclic saturated hydrocarbon resin (c) and the xylene resin (g) is preferably dissolved in the monomer main component in advance.

Next, the fifth invention will be described. The photopolymerizable composition used in the fifth invention is the same photopolymerizable composition as that used in any of the first invention to the fourth invention.

Examples of the base material used in the fifth invention include plastic sheets or films of polyethylene, polypropylene, polycarbonate, acrylic resin, vinyl chloride resin or the like, or paper. The surface of the plastic sheet or film may be release-treated.

In the fifth invention, a viscoelastic product such as an adhesive tape is obtained by coating or impregnating a substrate with the photopolymerizable composition and then irradiating it with light to polymerize it.

The lamp used for light irradiation preferably has a light emission distribution at a wavelength of 400 nm or less, and examples thereof include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a chemical lamp, a black light lamp, a metal halide lamp, A microwave-excited mercury lamp or the like is used.

Among these, the ultra-high pressure mercury lamp efficiently emits light in the active wavelength region of the initiator, and has a short wavelength of light or photoreactivity that reduces the viscoelastic properties of the obtained polymer by crosslinking. It is preferable because it does not emit much long-wavelength light that evaporates the composition by heating. In particular, as an ultra-high pressure mercury lamp, a so-called water-cooled type in which a jacket of circulating water is provided on the lamp is remarkably effective.

The light intensity of the lamp is a factor that influences the degree of polymerization of the polymer obtained from the photopolymerizable composition, and is appropriately selected depending on the performance of the intended product. For example, when a general cleavage type photopolymerization initiator having an acetophenone group is blended, the light intensity in the wavelength region (usually 365 to 420 nm) effective for photodecomposition of the polymerization initiator is 0.1 to 10
The range of 0 mW / cm ² is preferable. 0.1 mW / cm ²
When the light intensity is less than 1, the variation of the induction time due to the inhibition of oxygen reaction becomes large, and it becomes difficult to obtain a polymer having a constant degree of polymerization. Also, 100 mW / cm
^{When the} light intensity exceeds ² , it becomes difficult to maintain the balance between cohesive force and stress dispersibility due to a large decrease in molecular weight, and it becomes difficult to suppress peeling of the end portion while suppressing bubble generation.

In the fifth invention, the photopolymerization reaction is inhibited by oxygen in the air and oxygen dissolved in the photopolymerizable composition. In order to prevent such reaction inhibition of oxygen, for example, a method of coating the photopolymerizable composition with a film made of polyethylene terephthalate (hereinafter referred to as PET) or a Teflon film and irradiating with light through this film can be mentioned.

As another method for preventing oxygen reaction inhibition, for example, oxygen is replaced by an inert gas such as nitrogen gas or carbon dioxide, and the reaction is carried out in an inert zone having a light-transmitting window. May be. In this case, in order to sufficiently complete the reaction so that the conversion rate of the polymerizable composition is 99.7% or more, the oxygen concentration in the irradiation atmosphere is 5000.
It is preferably at most ppm. Further, the molecular weight of the polymer obtained by light irradiation in the inert zone decreases with an increase in the oxygen concentration in the irradiation atmosphere, so in order to obtain a molecular weight similar to that in polymerization under completely inert conditions, More preferably, the oxygen concentration in the irradiation atmosphere is 1000 ppm or less.

In the above-mentioned polymerizable composition, the surface layer portion irradiated with light is more susceptible to oxygen inhibition from the inside, and the cohesive force is lowered. Therefore, the cohesive force between the surface layer portion and the inside is made approximately the same. Further, it is more preferable that the oxygen concentration in the irradiation atmosphere is 300 ppm or less.

[0075]

The photopolymerizable composition of the first invention contains a specific amount of an alicyclic saturated hydrocarbon resin, so that it does not cause polymerization inhibition under high-speed reaction conditions, so that the polymer can have a high molecular weight. It also provides a strong adhesive force while maintaining a high level of high temperature holding power.

Since the photopolymerizable composition of the second invention contains a specific amount of a terpene phenol-based tackifying resin or a coumarone-based tackifying resin, there is almost no inhibition of polymerization under high-speed reaction conditions, and therefore a high molecular weight is obtained. It is possible to exert strong adhesive force while maintaining high temperature holding power.

Since the tackifying resin composed of the alicyclic saturated hydrocarbon resin and the xylene resin contained in the photopolymerizable composition of the third invention has a low polarity due to its structure, the pressure-sensitive adhesive after polymerization has a low energy surface. It is considered that it exhibits high adhesiveness to the olefin-based adherend. Further, since these resins have a low molecular weight, it is considered that they have good followability to uneven surfaces and exhibit strong adhesiveness.

Since the photopolymerizable composition of the fourth invention contains a polyfunctional vinyl compound having a high molecular weight, the distance between the cross-linking points between the produced polymers becomes long and the flexibility of the cross-linked polymer is improved. It is considered that a pressure-sensitive adhesive having excellent shear holding power at high temperature can be produced since it has good followability to uneven surfaces, exhibits strong adhesion, and has a sufficient degree of crosslinking.

[0079]

EXAMPLES Examples of the present invention will be described below. (Example 1) [Preparation of photopolymerizable composition] 2-ethylhexyl acrylate (2EHA), N-vinylpyrroline (VP) and carboxyethyl acrylate (CEA) were used in a weight ratio of 2
A photopolymerization initiator (“Darocur 1173” manufactured by Ciba-Geigy Co., Ltd.) 0.0 with respect to 100 parts by weight of the monomer main component blended so that EHA / VP / CEA = 90/4/6.
After adding 2 parts by weight and polymerizing to a viscosity capable of coating by irradiation with ultraviolet rays, 1.34 parts by weight of a photopolymerization initiator (“Darocur 2959” manufactured by Ciba-Geigy) and an alicyclic saturated hydrocarbon resin (Arakawa Chemical company "Arcon P-12
5 ") and 0.05 part by weight of hexanediol diacrylate (HDDA) were uniformly mixed to prepare a photopolymerizable composition.

[Preparation of Adhesive Tape (Viscoelastic Product)] The above photopolymerizable composition was applied onto a PET substrate (thickness: 38 μm).
After coating with a comma coater to a coating thickness of 60 μm, this coating was used in an inert zone with an oxygen concentration of 200 ppm and an ultrahigh pressure mercury lamp as a radiation source with a light intensity of 15 mW / cm ^{2 on} the irradiation surface. The lamp height was set so that the light intensity measuring instrument UVR-1 (manufactured by Tokyo Optical Machinery Co., Ltd.) having a maximum sensitivity at 365 nm]. Then, the photopolymerizable composition was polymerized by irradiation with ultraviolet rays for 1.5 minutes to prepare an adhesive tape using the polymer as an adhesive. The residual monomer in the obtained polymer was 0.
It was 3% by weight and the molecular weight was 470,000. The molecular weight was determined by GPC analysis for the polymerized under exactly the same conditions except that HDDA was not used (hereinafter the same).

[Evaluation of Performance of Adhesive Tape] In order to evaluate the performance of the above-mentioned adhesive tape, the following three physical properties were measured and the results are shown in Table 1. (1) 180 degree peel adhesive force Based on JIS Z0237, a polypropylene plate was measured as a test plate. (2) Holding power at 80 ° C. According to JIS Z0237, a stainless plate was used as a test plate for measurement. (3) Ball tack Measured at 7 ° C. according to JIS Z0237.

(Examples 2 to 6) Saturated alicyclic hydrocarbon resin (Arcon "P-125" or "P-140") and H
A photopolymerizable composition was prepared in the same manner as in Example 1 except that the amount of DDA was changed to that shown in Table 1 to prepare an adhesive tape. Physical properties of the above-mentioned pressure-sensitive adhesive tape were measured in the same manner as in Example 1, and the results are shown in Table 1. The residual monomer in the adhesive was 0.3% by weight, and the molecular weight was 47.
It was good.

(Examples 7 to 9) 2EHA / VP by weight ratio
A photopolymerizable composition was prepared in the same manner as in Example 1 except that the amount of HDDA was changed to the amount shown in Table 1 by using the monomer main component blended so that / CEA = 84/10/6. Then, an adhesive tape was produced. With respect to this adhesive tape, physical properties of the same items as in Example 1 were measured, and the results are shown in Table 1.
It was shown to. The residual monomer in the adhesive is 0.3% by weight.
And the molecular weight was 470,000.

[0084]

[Table 1]

Comparative Examples 1 to 3 Photopolymerization was carried out in the same manner as in Example 1 except that the alicyclic saturated hydrocarbon resin was not used at all and the addition amount of HDDA was changed as shown in Table 2. The composition was prepared and an adhesive tape was produced. With respect to this adhesive tape, the physical properties of the same items as in Example 1 were measured, and the results are shown in Table 2. The residual monomer of the adhesive is 0.3
% By weight and the molecular weight was 470,000.

Comparative Examples 4 to 6 Photopolymerization was carried out in the same manner as in Example 7 except that the alicyclic saturated hydrocarbon resin was not used at all and the amount of HDDA added was changed as shown in Table 2. The composition was prepared and an adhesive tape was produced. With respect to this adhesive tape, the physical properties of the same items as in Example 1 were measured, and the results are shown in Table 2. The residual monomer of the adhesive is 0.3
% By weight and the molecular weight was 470,000.

[0087]

[Table 2]

(Examples 10 to 15) A terpene phenol-based tackifying resin (YS) was used instead of the alicyclic saturated hydrocarbon resin.
Polyster "TH-130" or "TH-100") is used, and terpene phenolic tackifying resin and HDD
A photopolymerizable composition was prepared in the same manner as in Example 1 except that A was changed to the amount shown in Table 3, and an adhesive tape was produced from this photopolymerizable composition. 1 per adhesive tape
The 80 degree peel adhesion and the 80 ° C holding power were measured in the same manner as in Example 1, and the results are shown in Table 3. The residual monomer in the pressure-sensitive adhesive was 0.3% by weight, and the molecular weight was 470,000.

(Examples 16 to 18) A terpene phenol-based tackifying resin (YS) was used instead of the alicyclic saturated hydrocarbon resin.
Polyster "TH-130") was used and a photopolymerizable composition was prepared in the same manner as in Example 7 except that the amounts of the terpene phenolic tackifying resin and HDDA were changed to those shown in Table 3. An adhesive tape was prepared from the photopolymerizable composition. With respect to the above-mentioned pressure-sensitive adhesive tape, the 180-degree peel adhesive force and the 80 ° C holding force were measured in the same manner as in Example 1, and the results are shown in Table 3. The residual monomer in the adhesive was 0.
It was 3% by weight and the molecular weight was 470,000.

[0090]

[Table 3]

(Examples 19 to 24) A coumarone tackifying resin (escrystal "A-120S" or "A-100S") was used in place of the alicyclic saturated hydrocarbon resin, and a coumarone tackifying resin and A photopolymerizable composition was prepared in the same manner as in Example 1 except that the amount of HDDA was changed to that shown in Table 4, and an adhesive tape was produced from this photopolymerizable composition. With respect to the pressure-sensitive adhesive tape, the 180 ° peel adhesive force and the 80 ° C holding force were measured in the same manner as in Example 1, and the results are shown in Table 4. The residual monomer in the adhesive was 0.
It was 3% by weight and the molecular weight was 470,000.

[0092]

[Table 4]

Examples 25 to 30 Preparation of Photopolymerizable Composition and Adhesive Tape (Viscoelastic Product)
Preparation of] Aliphatic saturated hydrocarbon resin in place of alicyclic saturated hydrocarbon resin ("Arcon P-125" manufactured by Arakawa Chemical Co., Ltd.)
And xylene resin (“Nicanol GHP manufactured by Mitsubishi Gas Chemical Company
-160 ") is used in combination, and alicyclic saturated hydrocarbon resin (" Arcon P-125 "manufactured by Arakawa Chemical Co., Ltd.), xylene resin (" Nicanol GHP-16 manufactured by Mitsubishi Gas Chemical Co., Ltd. "
0 ") and HDDA in the amounts shown in Table 5, except that the photopolymerizable composition was prepared in the same manner as in Example 1.
An adhesive tape was produced from this photopolymerizable composition. The residual monomer in the pressure-sensitive adhesive was 0.3% by weight, and the molecular weight was 470,000.

[Evaluation of Performance of Adhesive Tape] In order to evaluate the performance of the above-mentioned adhesive tape, the following four physical properties were measured and the results are shown in Table 5. (1) 180 degree peel adhesive force Based on JIS Z0237, a polypropylene plate was measured as a test plate. (2) Holding power at 80 ° C. According to JIS Z0237, a stainless plate was used as a test plate for measurement.

(3) Curved Surface Adhesiveness Only this curved surface adhesiveness test was carried out as a sample in Example 2 above.
In the production of the pressure-sensitive adhesive tapes 5 to 30, in the same manner as in Examples 25 to 30 except that the PET base material (thickness 38 μm) was replaced with the PET base material (thickness 38 μm) whose surface was subjected to mold release treatment. The obtained adhesive tape was used (the same applies hereinafter).
The test was performed by the test apparatus 1 shown in FIG. Width 200m
A polypropylene plate 2 having a thickness of 2 mm and a thickness of 2 mm was fitted into a frame 3 having a width of 190 mm to form a curved surface, and a polypropylene plate curved surface was produced. Next, width 20 mm, length 150 mm, thickness 0.
The pressure-sensitive adhesive tape 5 was attached to a 5 mm aluminum plate 4, the release-treated PET base material was peeled off, and then attached to the curved surface of the polypropylene plate. Temperature 25 in this state
Adhesive tape 5
The number of days until the peeling started was observed.

(4) 90-degree peel holding power The test device 6 shown in FIG. 2 was used. Width 50mm, length 1
Width 20 on polypropylene plate 7 of 50 mm and thickness 2 mm
mm, 150 mm in length, the above-mentioned adhesive tape 8 is attached, and a triangular jig 9 (a wire is bent in a triangular shape. Weight is attached to one end of the attached adhesive tape. 4 g) is attached, then the adhesive tape-attached surface is held horizontally and left in a thermostatic chamber at 60 ° C. for 20 minutes. Next, weigh 1 g of 80 g on the jig 9.
After 0 was attached and left for 1 hour, the length of the adhesive tape 8 peeled from the polypropylene plate 7 is measured.

[0097]

[Table 5]

For comparison, the adhesive tapes obtained in Comparative Examples 1 to 3 and Examples 1 to 3 were subjected to the same four physical property measurements as above, and the results are shown in Table 6.

[0099]

[Table 6]

(Example 31) [Preparation of photopolymerizable composition] 2-ethylhexyl acrylate (2EHA), N-vinylpyrroline (VP) and carboxyethyl acrylate (CEA) in a weight ratio of 2 were used.
For 100 parts by weight of the monomer main component blended so that EHA / VP / CEA = 84/10/6, a photopolymerization initiator (“Darocur 1173” manufactured by Ciba-Geigy) was added.
After adding 02 parts by weight and polymerizing by UV irradiation to a viscosity capable of coating, 1.34 parts by weight of a photopolymerization initiator (“Darocur 2959” manufactured by Ciba-Geigy) and a crosslinking agent (manufactured by Shin-Nakamura Chemical Co., Ltd.) "UNI TACK K-10
0 ") 3 parts by weight were uniformly mixed to prepare a photopolymerizable composition.

[Production of Adhesive Tape (Viscoelastic Product)] An adhesive tape was produced in the same manner as in Example 1 except that the above photopolymerizable composition was used. Example 25 for the above adhesive tape
The same 4 items of physical properties were measured and the results are shown in Table 7. The residual monomer in the pressure-sensitive adhesive was 0.3% by weight, and the molecular weight was 470,000. The molecular weight was determined by GPC analysis for the polymerized under exactly the same conditions except that no crosslinking agent was used (the same applies hereinafter).

(Examples 32 and 33) Crosslinking agent (UNIT
A photopolymerizable composition was prepared in the same manner as in Example 31, except that the amount of ACK K-100) was changed to that shown in Table 7, to prepare an adhesive tape. With respect to the above adhesive tape, four physical properties were measured in the same manner as in Example 25, and the results are shown in Table 7.
It was shown to. The residual monomer in the adhesive is 0.3% by weight.
And the molecular weight was 470,000.

Further, with respect to the pressure-sensitive adhesive tapes obtained in Comparative Examples 4 to 6, the same four physical properties as described above were measured and the results are shown in Table 7.

[0104]

[Table 7]

(Example 34) Instead of the cross-linking agent (UNI TACK K-100) in Example 31, a cross-linking agent (UNI TACK K-100), an alicyclic saturated hydrocarbon resin ("Arcon P" manufactured by Arakawa Chemical Co., Ltd.) was used. -125 ") and xylene resin (" Nicanol GHP-1 "manufactured by Mitsubishi Gas Chemical Co., Inc.
60 ") is also used in combination with an alicyclic saturated hydrocarbon resin,
A photopolymerizable composition was prepared in the same manner as in Example 31 except that the amounts of the xylene resin and the cross-linking agent were changed to those shown in Table 8, and the photopolymerizable composition was adhered in the same manner as in Example 1. A tape was prepared and the same four physical properties as in Example 25 were measured. The results are shown in Table 8. The residual monomer in the pressure-sensitive adhesive was 0.3% by weight, and the molecular weight was 470,000.

(Examples 35 to 39) Xylene resin (Nicanol GHP-160) and cross-linking agent (UNI TACK)
A photopolymerizable composition was prepared in the same manner as in Example 34 except that the amount of K-100) was changed to that shown in Table 8 to prepare an adhesive tape. With respect to the pressure-sensitive adhesive tape, four physical properties were measured in the same manner as in Example 25, and the results are shown in Table 8. The residual monomer in the pressure-sensitive adhesive was 0.3% by weight, and the molecular weight was 470,000.

[0107]

[Table 8]

[0108]

The photopolymerizable composition of the first and second inventions comprises
By adding an alicyclic saturated hydrocarbon resin, a terpene phenol-based tackifying resin or a coumarone-based tackifying resin as a tackifier, it is excellent even for various plastic base materials including polyolefins, coated plates, etc. It exhibits low-temperature initial adhesiveness, tackiness and high-temperature holding power. The photopolymerizable compositions of the third and fourth inventions are various plastic base materials containing a polyolefin-based resin by adding an alicyclic saturated hydrocarbon resin and a xylene resin as tackifiers,
It also exhibits excellent low-temperature initial adhesion, adhesive strength and high-temperature holding power even for coated plates, etc., and is particularly excellent for polyolefin substrates such as polyethylene and polypropylene, which are low energy surfaces Develops long-term adhesiveness. The method for producing a viscoelastic product of the fifth invention is
Since there is no reaction inhibition or polymerization inhibition in the photopolymerization step, viscoelastic products such as adhesive tape having excellent performance can be produced with high efficiency and high speed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an apparatus for a curved surface adhesion test.

FIG. 2 is a perspective view showing an apparatus for 90-degree peel holding power test.

[Explanation of symbols]

 1 Testing device 2 Polypropylene plate 3 Frame 4 Aluminum plate 5 Adhesive tape 6 Testing device 7 Polypropylene plate 8 Adhesive tape 9 Jig 10 Weight

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C09J 7/02 JJY JKZ 133/06 JDD

Claims (5)

[Claims] (A) 60 to 99% by weight of at least one acrylate-based monomer selected from the group consisting of (meth) acrylic acid alkyl esters of alkyl alcohols having an alkyl group having 1 to 14 carbon atoms; b) 100 parts by weight of a monomer main component consisting of 1 to 40% by weight of a monoethylenically unsaturated compound copolymerizable with the acrylate-based monomer, and (c) an alicyclic saturated hydrocarbon resin 0.5.
To 30 parts by weight and (d) 0.001 to 5 parts by weight of a photopolymerization initiator, a photopolymerizable composition. 2. (a) 60 to 99% by weight of at least one acrylate-based monomer selected from the group consisting of (meth) acrylic acid esters of alkyl alcohols having an alkyl group having 1 to 14 carbon atoms; ) Monomer main component 100 comprising 1 to 40% by weight of a monoethylenically unsaturated compound copolymerizable with the acrylate-based monomer
Photopolymerization, characterized in that it contains 0.5 part by weight, (e) 0.5 to 40 parts by weight of a terpene phenol-based tackifying resin or coumarone-based tackifying resin, and (d) 0.001 to 5 parts by weight of a photopolymerization initiator. Sex composition. 3. (a) 60 to 99% by weight of at least one acrylate-based monomer selected from the group consisting of (meth) acrylic acid alkyl esters of alkyl alcohols having an alkyl group having 1 to 14 carbon atoms; b) From 100 parts by weight of a monomer main component consisting of 1 to 40% by weight of a monoethylenically unsaturated compound copolymerizable with the acrylate-based monomer, (c) an alicyclic saturated hydrocarbon resin, and (g) a xylene resin. Tackifying resin 0.5-4
A photopolymerizable composition comprising 0 parts by weight and 0.001 to 5 parts by weight of (d) a photopolymerization initiator. 4. (a) 60 to 99% by weight of at least one acrylate-based monomer selected from the group consisting of (meth) acrylic acid esters of alkyl alcohols having an alkyl group having 1 to 14 carbon atoms; ) Monomer main component 100 comprising 1 to 40% by weight of a monoethylenically unsaturated compound copolymerizable with the acrylate-based monomer
Parts by weight, (h) the weight average molecular weight measured by GPC is 50
A photopolymerizable composition comprising 1 to 50 parts by weight of a polyfunctional vinyl compound of 00 or more and (d) 0.001 to 5 parts by weight of a photopolymerization initiator. 5. A method for producing a viscoelastic product, which comprises irradiating with light after coating or impregnating a substrate with the photopolymerizable composition according to any one of claims 1 to 4.