JPS6236476A - Electromagnetic wave curing solvent-free adhesive composition - Google Patents

Abstract

PURPOSE:To enhance the cohesive force and adhesion, by blending an oligoester acrylate having a benzene nucleus, an particular rubbery polymer and a tackifier as essential ingredients without adding any volatile solvent. CONSTITUTION:A compsn. comprising 100pts.wt. oligoester acrylate having a benzene nucleus, 0.5-20pts.wt. rubbery polymer soluble in the oligoester acrylate and having a glass transition point of 0 deg.C or below and 1-30pts.wt. tackifier as essential ingredients and free from any a volatile solvent. Examples of the oligoester acrylate include phenol-polyethylene oxide adduct monoacrylate and bisphenol glycidyl monoacrylate. A preferable rubbery polymer is a block copolymer of isoprene with styrene. The tackifier may be conventionally used ones (e.g., rosin or its ester).

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an adhesive composition, and more particularly to an adhesive composition that is cured by electromagnetic waves and does not contain volatile solvents.

<Prior Art and Problems> Conventionally, pressure-sensitive adhesives and adhesives have been widely used to bond adherends together. Double-sided tape with release paper attached to both sides is known as an adhesive, but in order to attach adherends to each other, first cut the double-sided tape to the length to be bonded, and then attach release paper to one side. It is necessary to peel off the paper and attach it to one adherend, then peel off the release paper on the other side, and then attach it to the other adherend, which requires a large number of steps and is complicated, so it is done in an automated process. That is extremely difficult.

In addition, hot-melt adhesives and solvent-volatile adhesives are known as adhesives, and since both can be applied directly onto the adherend, it is relatively easy to incorporate them into automated processes, but the former Because they must be melted, if the melting temperature is high, the adherend may be damaged by heat, and if the melting temperature is lowered, the viscosity increases, making it difficult to coat, and the amount of coating becomes thick. On the other hand, in the latter case, it takes time for the solvent to volatilize, the adherend is eroded by the solvent, and it is necessary to be careful of fire caused by the solvent volatilization, which requires the installation of explosion-proof equipment, which increases equipment costs. Other problems arise in the solvent-based working environment.

Light-curing adhesives and two-component poxy adhesives are known as adhesives, but the former cures by irradiation with light and cannot be applied unless the adherend is light-transmissive. The latter method requires weighing and mixing the two liquids, resulting in a complicated process, and has drawbacks such as the problem of pot life and the need for a pressing jig for curing after bonding.

Yet again. In the production of adhesive tapes, many UV-curable adhesives containing photosensitizers in acrylic monomers have been proposed; If it is dissolved, there are the above-mentioned problems associated with solvent volatilization, and there are also various disadvantages such as odor and poor compatibility of component compositions.

<Object of the Invention> According to the present invention, the adhesive has excellent adhesive performance such as adhesive strength, holding power, and pole tack property, has good heat resistance, and is easily cured by electromagnetic waves without containing volatile solvents. There is no risk of damage to the adherend, and there is no special jig other than the irradiator.
The object of the present invention is to provide an electromagnetic wave-curable solvent-free adhesive composition that can be bonded in a good working environment without the need for equipment.

Means for solving the above problems〉 Oligoester acrylate 100 having benzene nucleus
parts by weight, 0.5 to 20 parts by weight of a rubbery polymer dissolved in the oligoester acrylate and having a glass transition point of 0° C. or less, and 1 to 30 parts by weight of a tackifier, and contains no volatile solvent. An electromagnetic wave curable solvent-free adhesive composition is provided.

The present invention will be explained in more detail below.

In the adhesive composition of the present invention, an oligoester acrylate having a benzene nucleus is used as an essential component.

Examples of oligoester acrylates that can be used in the present invention include phenol polyethylene oxide adduct monoacrylate, nonylphenol polyethylene oxide adduct monoacrylate, phenyl glycidyl ether monoacrylate, bisphenol glycidyl monoacrylate, bisphenol diacrylate, and bisphenol polyethylene. Examples include oxide adduct monoacrylate, bisphenol ethylene oxide adduct diacrylate, alkylphenol polyethylene oxide adduct monoacrylate, and methacrylates thereof, and two or more thereof may be used in combination. Among these, acrylates are more preferred than methacrylates, and monoacrylates are more preferred than diacrylates. However, if higher heat resistance or higher cohesive strength is desired, methacrylate or diacrylate can be used in part or in whole, provided some tackiness is sacrificed.

The rubber-like polymer used in the present invention can be used as long as it is rubber-like at room temperature (glass transition point is 0° C. or lower) and dissolves in the oligoester acrylate having a benzene nucleus. Examples of such rubbery polymers include block copolymers of isoprene and styrene (SI
S), Isobu.

Styrene rubber and styrene block copolymer, styrene butadiene copolymer (SBR, 5BS), acrylic rubber,
Examples include a co-electric material of acrylonitrile and butadiene (NBR), a copolymer of styrene and butadiene, polyvinyl ether, polyether, polyurethane rubber, and the like. Among these, block copolymers of isoprene and styrene are preferred.

In the present invention, a tackifier is used as an essential component.

As tackifiers, conventionally well-known rosin, rosin ester, ester gum, partially hydrogenated rosin methyl ester, hydrogenated rosin glycerin ester, xylene resin, petroleum resin, hydride of petroleum resin, polybutene, poly- 2-Methyl rosin methyl ester, rosin glycerin ester.

Examples include hydrogenated rosin. In addition, polyacrylic esters used in acrylic adhesives, such as copolymers of butyl acrylate and diglycidiyl methacrylate that are further reacted with acrylic acid, ethyl acrylate, butyl acrylate, diglycidiyl methacrylate, etc. It is also possible to use a copolymer of Eel methacrylate further reacted with acrylic acid.

In the present invention, the blending ratio of each component of the adhesive composition is 100 parts by weight of oligoester acrylate having a benzene nucleus, and 0.5 to 20 parts by weight of a rubbery polymer having a glass transition point of 0° C. or lower that is dissolved in the oligoester acrylate. parts by weight, preferably 2 to 7 parts by weight, and 1 to 30 parts by weight of a tackifier,
Preferably it is 10 to 25 parts by weight. If the amount of the rubbery polymer is less than 0.5 parts by weight, performance problems will occur;
In particular, the cohesive force decreases, and stable performance cannot be obtained.

On the other hand, if the amount exceeds 20 parts by weight, it becomes difficult to dissolve and disperse in the oligoester acrylate, and even if dissolution and dispersion is possible, the solution viscosity becomes extremely high, causing a practical problem. If the amount of the tackifier is less than 1 part by weight, the tackiness will decrease and stable tackiness will not be obtained. On the other hand, if the amount exceeds 30 parts by weight, the adhesiveness will be improved, but problems will arise in terms of performance, and in particular, the heat resistance (heat resistance creep property) will be significantly lowered.

In the present invention, since an oligoester acrylate having a benzene nucleus is used, the double bonds of this acrylate start polymerizing when irradiated with electromagnetic waves, and the liquid component of the acrylate becomes solid, quickly forming an adhesive. . Furthermore, oligoester acrylate having a benzene nucleus has no odor and has good compatibility with a rubbery polymer and a tackifier, so that a stable adhesive composition can be provided without using a volatile solvent.

The adhesive composition of the present invention is cured by simply irradiating it with electromagnetic waves for several seconds to several tens of seconds. As the electromagnetic waves, light, mainly ultraviolet rays and radiation such as γ rays, α rays, β rays, X rays, and electron beams, can be used. When radiation is used instead of light (visible light or ultraviolet light) as electromagnetic waves, there is no need to add a photosensitizer or the like. This is because molecules are excited and ionized when a substance is irradiated with high-energy radiation such as electron beams or gamma rays.

When light, mainly ultraviolet light, is used as the electromagnetic wave, a photosensitizer or a photopolymerization accelerator is added to the pressure-sensitive adhesive composition.

Examples of ultraviolet rays include sunlight, low-pressure mercury lamps, high-pressure mercury lamps,
Irradiation can be performed using an ultra-high pressure mercury lamp, a xenon mercury lamp, a carbon arc lamp, a metal halide lamp, etc.

Examples of photosensitizers include benzoins such as benzoin ethyl ether, benzoin isoprobyl ether, benzoin isobutyl ether, benzoin, and 2-methylbenzoin; anthraquinones such as 9t 10-anthraquinone, 1-chloroanthraquinone, and 2-chloroanthraquinone; Benzophenones such as benzophenone, p-chlorobenzophenone, P-dimethylaminobenzophenone, 4,4'-bis(dinitylamino)benzophenone, jetoxyacetophenone; sulfur compounds such as diphenyl disulfide tetramethylthiuram disulfide; methylene blue, eosin, fluorescein,
Examples include 1-hydroxycyclohexylphenyl ketone and benzyl methyl ketal. A mixture of two or more of these may also be used.

In addition, as a photopolymerization accelerator, diethylenetriamine,
Tetraethylenepentamine, pentaethylenehexamine, N-methyljetanolamine, aminoethylethanolamine, n-aminopiperazine, diaminodiphenylmethane, dimethylaniline, diethylaniline, dimethyltoluidine, diethyltoluidine, triethanolamine, dithymeraminoethyl Examples include amines such as methacrylate, diethylaminoethyl methacrylate, and 2,4.6-dimethylaminomethylphenol. A mixture of two or more of these may also be used. A photosensitizer does not necessarily need to be used in combination with a photopolymerization accelerator, and can also be used alone. The amount of photosensitizer used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight of oligoester acrylate. In addition, when using a photopolymerization accelerator in combination, 0.1 to 0.1 to 100 parts by weight of oligoester acrylate
It is desirable to use 10 parts by weight, preferably 0.1 to 5 parts by weight.

In addition, when using a rubber-like substance with a double bond other than the double bond between oligoester acrylate and benzene nucleus, heating causes post-curing, which reduces adhesiveness but increases adhesive strength and heat resistance. It has the characteristics of

The adhesive composition of the present invention includes an acrylic monomer, a polymer, a plasticizer, an adhesion promoter, a filler, a pigment, a polymerization inhibitor,
Stabilizers, anti-aging agents, etc. as required.

It can be added as long as it does not cause any practical problems.

When adhering adherends using the adhesive composition of the present invention, the adhesive composition is applied to one or both adhesive surfaces of the adherend, and then irradiated with electromagnetic waves to form an adhesive. In this irradiation step, since the adhesive surface is exposed and irradiated, the adhesive can be formed without depending on the electromagnetic wave permeability of the adherend. In the case of automation, it is sufficient to pass the electromagnetic wave under irradiation at a predetermined speed under the irradiation of an electromagnetic wave irradiation device, and an adhesive is formed on the adhesive surface simply by irradiating the electromagnetic wave for several seconds to several tens of seconds.

As the final step, the adhesive surfaces of the adherends are joined and pasted. In this process, for example, the adherend is passed between pressure rolls,
It is possible to firmly bond adherends simply by pressing with a predetermined pressure.

<Effects of the Invention> The adhesive composition of the present invention has high cohesive force and strong adhesiveness and adhesion, and is easily cured by electromagnetic waves, making it suitable for bonding adherends using automated equipment. Moreover, since volatile solvents are not used, there is no need for any explosion-proof equipment due to environmental concerns or fire hazards.

<Example> Hereinafter, the present invention will be specifically explained with reference to Examples.

Nu11"L Phenol polyethylene oxide adduct monoacrylate (trade name, Aronix MIOI.

4 parts by weight of a block copolymer of isoprene and styrene (trade name, CARIFLEX TR-1107, manufactured by Shell Kagaku Co., Ltd.) as a rubber-like polymer and 4 parts by weight of Pentaeri as a tackifier. 15 parts by weight of Statol rosin ester (trade name, Super Ester A115, manufactured by Arayo Chemical Industry ■) and hydrogenated petroleum resin (trade name, Alcon P-100, manufactured by Arakawa Chemical Industry ■)
After dissolving 5 parts by weight, 4 parts by weight of photosensitizer 1-hydroxycyclohexylphenyl ketone was dissolved to prepare an adhesive composition solution.

4 parts by weight of the rubbery polymer used in Example 1 and a tackifier (Super Ester A115) and 15 parts by weight of tackifier (Alcon P
-100) was dissolved, and then 4 parts by weight of 1-hydroxycyclohexylphenyl ketone as a photosensitizer was dissolved to prepare an adhesive composition solution.

Kanba Gai 100 parts by weight of oligoester acrylate (Aronix Mill) used in Example 2, 2 parts by weight of acrylonitrile butadiene rubber (trade name, Hiker 1072, manufactured by Gudridge) having a carboxyl group as a rubbery polymer. and the tackifier used in Example 1 (
Superester Al 15.15 parts by weight and Alcon P-
(1005 parts by weight) and 4 parts by weight of 1-hydroxycyclohexylphenyl ketone as a photosensitizer were dissolved to prepare an adhesive composition.

Methylene-butadiene-styrene copolymer (
An adhesive composition was prepared by dissolving 3 parts by weight (trade name: CARIFLEX TR-1102, manufactured by Shell Chemical Co., Ltd.), 2 parts by weight of 1-hydroxycyclohexylphenyl ketone, and 2 parts by weight of benzophenone.

Taihohan Phenylglycidyl ether monoacrylate (trade name, Aronix M5700, manufactured by Toagosei Chemical Industry Co., Ltd.)
To 100 parts by weight, 5 parts by weight of the rubbery polymer (Cariflex TR1107) used in Example 1, 20 parts by weight of the tackifier (Superester A115), and 4 parts by weight of diethylaminoethyl methacrylate as a crosslinking agent were added. An adhesive composition was prepared by dissolving 4 weights of 1-hydroxycyclohexyl phenyl ketone as a sensitizer.
A pressure-sensitive adhesive composition solution was prepared in the same manner as in Example 1 using the same components and the same parts by weight except for R1107).

Nonylphenol polyethylene oxide adduct monoacrylate of Example 2 (trade name Aronix Mill)
An adhesive composition solution was prepared in the same manner as in Example 2, except that 50 parts by weight of butyl acrylate and 50 parts by weight of hexyl acrylate were used instead of 100 parts by weight.

A pressure-sensitive adhesive composition solution of Example 3 was prepared without using the tackifier of Example 3, Superester A115, and Alcon P-100.

Each adhesive composition solution described above was applied to a thickness of 25μ on a polyester film having a thickness of 25μ, and an ultraviolet irradiation device (manufactured by Eye Graphic Co., Ltd., Metal Palite Lamp 120W/C!11. An adhesive was formed on the polyester film by irradiating at a speed of 1.4 m/win (with an irradiation height of 151 mm and using a cold mirror parallel light reflector), and various performance tests as described below were conducted. The results are shown in Table 1.

Test method> Adhesive force> Based on JIS Z 0237-1980.

A 25m+width test piece was prepared using SO5304 ((180IX 1
20 minutes later, this is peeled off at a speed of 300 nm/min in a direction of 180 degrees, and the peel strength is measured.

Holding force > Conforms to JIS Z 0237-1980.

A test piece (tt) with an area of 25 m x 25 mm + 171 mm was attached to one end of the test plate (the above-mentioned 5IJS 304 steel plate), and after being left in an atmosphere at 40°C for 30 minutes, a load of 1 kg was applied to the bottom of the test piece, and the test piece was measure the time,
If it is kept for 1 hour, it is considered OK, and if it falls, the falling time is measured.

<Ball tack property> JIS Z 0237-1980
2.

A test piece is set on a glass plate with an inclination of 30 degrees with the adhesive side facing up, a 25 μm thick polyester film is applied as a run-up path, and the measuring section is the adhesive surface within a range of 100 mm from the lower end of the run-up path. The run-up path for the ball (8 balls) is 100-
It is expressed as the maximum diameter of the ball when rolled from the position where the adhesive surface of the measurement part stops. (The ball has a diameter of 2/3
There are 31 types from 2 to 32/32 inches, and 32 times the number, that is, the number in the numerator, is used as the measurement value. )Heat-resistant creep (1)〉 Using the same test piece as the method used to measure holding force, 40°C and 3o
After leaving it for a minute, start at 20℃ and heat up at a rate of 2 to 3.
The temperature is raised at ℃ and the temperature at which a 1 kg static load is dropped is measured.

<Heat-resistant creep (2)> The measurement method is the same as that of heat-resistant creep (1), but the heat-resistant creep test is carried out after curing the test piece at 50° C. for 24 hours before measurement.

Taiho Godan A pressure-sensitive adhesive solution was prepared in the same amount as in Example 1, but without the photosensitizer 1-hydroxycyclohexylphenyl ketone. Then, this solution was applied to a 25μ thick polyester film using a pulsed electron beam irradiation device Unitron 200/200 (USHIO INC.
A pressure-sensitive adhesive was formed on the polyester film by irradiation of 7 Mrad at an accelerating current of 180 keV using a polyester film, and the various performance tests described above were conducted.

A pressure-sensitive adhesive solution was prepared in the same amount as in Example 2 of Daigokaiyu, but without the photosensitizer. Then, electron beam irradiation was performed under the same conditions as in Example 6, and various performance tests were conducted.

1) 1 A pressure-sensitive adhesive solution was prepared in the same amount as in Example 5, but without the photosensitizer. Then, electron beam irradiation was performed under the same conditions as in Example 6, and various performance tests were conducted. Table 2 shows the results.
Shown below.

(Margin below)

Claims (1)

[Claims] Oligoester acrylate 100 with benzene nucleus
parts by weight, 0.5 to 20 parts by weight of a rubbery polymer dissolved in the oligoester acrylate and having a glass transition point of 0° C. or less, and 1 to 30 parts by weight of a tackifier, and contains no volatile solvent. An electromagnetic wave-curable solvent-free adhesive composition characterized in that it contains no solvent.