KR20200060340A - Active energy ray curable peelable adhesive composition - Google Patents

Abstract

Acrylic resin (A), urethane (meth) acrylate-based compound (B), active energy ray polymerization as an active energy ray-curable peelable pressure-sensitive adhesive composition capable of suppressing deterioration to a member to be processed and also excellent in pot life of the adhesive composition In the active energy ray-curable peelable pressure-sensitive adhesive composition containing an initiator (C) and a crosslinking agent (D), the acrylic resin (A) includes (meth) acrylic acid alkyl ester-based monomer (a1), hydroxyl group-containing monomer (a2), and carboxyl group Provided is an acrylic resin made by polymerizing a polymerization component including a containing monomer (a3), and an active energy ray-curable peelable pressure-sensitive adhesive composition having a carboxyl group-containing monomer (a3) content of 0.01 to 0.4% by weight of the polymerization component.

Description

Active energy ray curable peelable adhesive composition

The present invention relates to an active energy ray-curable peelable pressure-sensitive adhesive composition used for pressure sensitive adhesives for temporary surface protection when processing electronic substrates, semiconductor wafers, glass products, metal plates, plastic plates, and the like.

Conventionally, in processing processes such as cutting or perforation of electronic components, an adhesive film for surface protection for temporarily protecting a surface has been used for the purpose of preventing contamination or damage of a member to be processed, and recently it is not limited to electronic components. An adhesive film for surface protection is also used in the processing of various members.

By the way, in recent years, for the reasons of miniaturization of processing or thinning of the processing member, an appropriate adhesive force is required for the member to be processed, while after the role of surface protection is completed, it is necessary to peel the adhesive film for surface protection, and when peeling, it is weak It is desired to be able to peel without residual glue by force.

As an adhesive film or sheet for temporary surface protection, for example, Patent Document 1 is made by coating an adhesive layer made of an adhesive and a radioactive polymerizable urethane acrylate oligomer having a weight average molecular weight of 3,000 to 10,000 on a substrate surface. An adhesive sheet is disclosed. It is described that the adhesive force with the adherend is rapidly reduced by irradiating ultraviolet rays when the sheet is peeled off.

In addition, in Patent Document 2, an acrylic pressure-sensitive adhesive having a weight average molecular weight of 200,000 or more and a glass transition temperature of 60 to -30 ° C, and a hydroxyl group-containing acrylic compound having three or more acryloyl groups in the molecule, is a reactant of a diisocyanate compound. Disclosed is a repeelable pressure-sensitive adhesive with less residual pressure-sensitive adhesive when re-peeled using a urethane acrylate-based compound.

In Patent Document 3, the content of the catalyst is 30 to 100 ppm in the pressure-sensitive adhesive layer containing an isocyanate-based crosslinking agent, a polymer containing a functional group reactive with the isocyanate-based crosslinking agent, a urethane acrylate, and a catalyst, and the time after grinding is Adhesive tapes for processing, such as semiconductor wafers, that can exhibit good pick-up properties even when pasted on a wafer thereafter have been disclosed.

Patent document 1 JP S62-153376A Patent document 2 JP H11-293201A Patent document 3 JP 2013-152963A

However, in the disclosed technique of Patent Document 1, the adhesive force after curing of the peelable pressure-sensitive adhesive decreases, but there is a problem that the pressure-sensitive adhesive remains at the time of peeling, chips are scattered during dicing, or chips are peeled off at the time of expansion. It is not satisfactory.

In addition, the disclosed technique in Patent Document 2 has a technique of improving the residual glue at the time of peeling, but when an acrylic resin containing a carboxyl group-containing monomer as a polymerization component is used, the member to be processed is affected by the effect of the carboxyl group. There is a fear of changing the quality.

Although the above Patent Document 3 exhibits a good pick-up property even when attached to an adherend within a few hours after grinding, it contains a predetermined amount of catalyst, but the pot life during the coating process of the adhesive is influenced by the influence of the catalyst. There is a problem that it becomes shorter.

Therefore, in the present invention, under such a background, it is possible to suppress the deterioration of the member to be processed, and the active energy ray-curable peelable pressure-sensitive adhesive composition excellent in the pot life of the pressure-sensitive adhesive composition, in particular, the pressure-sensitive adhesive of the adhesive film for temporarily protecting the surface It provides an active energy ray-curable peelable pressure-sensitive adhesive composition used for.

By the way, the present inventor has repeatedly studied in consideration of such circumstances, and as a result, an acrylic resin (A), a urethane (meth) acrylate compound (B), an active energy ray polymerization initiator (C) and a crosslinking agent (D) It was found that the active energy ray-curable peelable pressure-sensitive adhesive composition containing a small amount of acid groups in the acrylic resin (A) does not deteriorate the member to be processed and is excellent in pot life during the pressure-sensitive adhesive coating process.

That is, the subject matter of the present invention is an active energy ray-curable peelable pressure-sensitive adhesive composition containing an acrylic resin (A), a urethane (meth) acrylate-based compound (B), an active energy ray polymerization initiator (C), and a crosslinking agent (D). In the above, the acrylic resin (A) is an acrylic resin obtained by polymerizing polymerization components including a (meth) acrylic acid alkyl ester monomer (a1), a hydroxyl group-containing monomer (a2), and a carboxyl group-containing monomer (a3), and the carboxyl group-containing monomer (a3) relates to an active energy ray-curable peelable pressure-sensitive adhesive composition having a content of 0.01 to 0.4% by weight of the polymerization component.

The present invention is an active energy ray-curable peelable pressure-sensitive adhesive composition containing an acrylic resin (A), a urethane (meth) acrylate-based compound (B), an active energy ray polymerization initiator (C) and a crosslinking agent (D), the acrylic Resin (A) is an acrylic resin obtained by polymerizing polymerization components including (meth) acrylic acid alkyl ester-based monomer (a1), hydroxyl group-containing monomer (a2), and carboxyl group-containing monomer (a3), wherein the carboxyl group-containing monomer (a3) Since the content ratio of is 0.01 to 0.4% by weight of the polymerization component, pot life is excellent. In addition, the pressure-sensitive adhesive using the active energy ray-curable peelable pressure-sensitive adhesive composition of the present invention can suppress deterioration to a member to be processed, and is particularly useful as an adhesive for the pressure-sensitive adhesive film to temporarily protect the surface.

When the urethane (meth) acrylate-based compound (B) contains 1 to 1,000 ppm by weight of at least one of the metal-based compound and the amino group-containing compound, it exhibits a more remarkable effect.

When the urethane (meth) acrylate-based compound (B) has an ethylenically unsaturated group and the number of the ethylenically unsaturated groups is 3 to 20, the peelability after active energy ray irradiation is excellent.

If the urethane (meth) acrylate-based compound (B) is a reactant of a hydroxyl group-containing (meth) acrylate-based compound (b1) containing three or more ethylenically unsaturated groups in the molecule and a polyvalent isocyanate-based compound (b2), It is more excellent in peelability after irradiation with active energy rays.

When the weight average molecular weight of the urethane (meth) acrylate-based compound (B) is 500 to 10,000, the peelability after active energy ray irradiation is more excellent.

When the weight average molecular weight of the acrylic resin (A) is 100,000 to 2 million, and the glass transition point temperature is -80 to 50 ° C, adhesion is excellent and contamination of the member to be processed can be prevented.

When the content of the urethane (meth) acrylate-based compound (B) is 25 to 100 parts by weight relative to 100 parts by weight of the acrylic resin (A), the peelability after active energy ray irradiation is more excellent.

Hereinafter, although the form for implementing this invention is demonstrated concretely, this invention is not limited to these.

In the present invention, "(meth) acrylic" means acrylic or methacryl, "(meth) acryloyl" means acryloyl or methacrylate, "(meth) acrylate" means acrylate or methacrylate. It means each.

Moreover, the "acrylic resin" is a resin obtained by polymerizing a polymerization component containing at least one (meth) acrylate monomer.

In addition, in the present invention, "film" does not specifically distinguish between "sheet" and "tape", and is described as meaning including these.

The active energy ray-curable peelable pressure-sensitive adhesive composition of the present invention is usually used as a pressure-sensitive adhesive for an adhesive film on the premise of peeling after bonding with a member to be processed once. The pressure-sensitive adhesive film is made by coating an active energy ray-curable peelable pressure-sensitive adhesive composition on a base sheet, and after bonding with a member to be processed, the pressure-sensitive adhesive is cured by irradiating an active energy ray to reduce adhesive strength, thereby making it easy to work. It can be peeled from the member.

The active energy ray-curable peelable pressure-sensitive adhesive composition of the present invention contains an acrylic resin (A), a urethane (meth) acrylate-based compound (B), an active energy ray polymerization initiator (C), and a crosslinking agent (D).

(Acrylic resin (A))

The acrylic resin (A) used in the present invention is obtained by polymerizing a polymerization component containing a (meth) acrylic acid alkyl ester monomer (a1), a hydroxyl group-containing monomer (a2), and a carboxyl group-containing monomer (a3).

As such a (meth) acrylic acid alkyl ester-based monomer (a1), it is preferable that the number of carbon atoms of the alkyl group is usually 1 to 20, preferably 1 to 12, and also 1 to 8, particularly 4 to 8. When the carbon number is too large, it tends to become easy to contaminate the member to be processed.

Specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, n -Propyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethyl hexyl (meth) acrylate, n-octyl (meth) acrylate, iso-octylacrylate, isodecyl (meth) acrylate, Aliphatic (meth) acrylic acid alkyl esters such as lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, and iso-stearyl (meth) acrylate; cyclohexyl (meth) acrylate And alicyclic (meth) acrylic acid esters such as isobornyl (meth) acrylate. These may be used alone or in combination of two or more.

Among the (meth) acrylic acid alkyl ester-based monomers (a1), methyl (meth) acrylate, n-butyl (meth) acrylate, and 2-ethyl from the viewpoints of copolymerizability, adhesion properties, ease of handling and availability of raw materials. Hexyl (meth) acrylate is preferably used.

The content of the (meth) acrylic acid alkyl ester-based monomer (a1) in the polymerization component is usually 30 to 99% by weight, preferably 40 to 98% by weight, more preferably 50 to 95% by weight. When such a content is too small, the adhesive force before active energy ray irradiation tends to fall easily, and when it is too large, the adhesive force before active energy ray irradiation tends to become too high.

The hydroxyl group-containing monomer (a2) is preferably a hydroxyl group-containing acrylate-based monomer, and specifically, for example, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, Acrylic acid hydroxyalkyl esters, such as 5-hydroxypentyl (meth) acrylate, 6-hydroxy hexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, caprolactone modified 2-hydroxyethyl (meth) ) Caprolactone-modified monomers such as acrylates, oxyalkylene-modified monomers such as diethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, 2-acryloyloxyethyl-2-hydroxy ethylphthalic acid, etc. Primary hydroxyl group-containing monomers; secondary hydroxyl group-containing monomers such as 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-chloro-2-hydroxypropyl (meth) acrylate; And tertiary hydroxyl group-containing monomers such as 2,2-dimethyl-2-hydroxyethyl (meth) acrylate. These may be used alone or in combination of two or more.

Among the above-mentioned hydroxyl group-containing monomers, primary hydroxyl group-containing monomers are more preferable from the viewpoint of excellent reactivity with the crosslinking agent (D) described later, and particularly 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate Is preferred.

The content of the hydroxyl group-containing monomer (a2) in the polymerization component is preferably 0.1 to 40% by weight, particularly preferably 0.2 to 30% by weight, more preferably 0.5 to 20% by weight. When the content is too large, crosslinking proceeds before the drying step, and there is a tendency that problems with coating properties tend to occur, and if too small, the degree of crosslinking decreases, and contaminants of the member to be processed tend to increase.

Examples of the carboxyl group-containing monomer (a3) include (meth) acrylic acid, acrylic acid dimer, crotonic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, glutaconic acid, itaconic acid, acrylamide N-glycolic acid, And cinnamon acid. Among them, (meth) acrylic acid is preferably used from the viewpoint of copolymerization. These may be used alone or in combination of two or more.

In the present invention, it is important that the content of the carboxyl group-containing monomer (a3) in the polymerized component is 0.01 to 0.4% by weight, preferably 0.03 to 0.4% by weight, more preferably 0.05 to 0.3% by weight, particularly preferably 0.1 to 0.2% by weight. If the content is too large, the member to be processed is deteriorated, or if the member to be processed is a metal, it becomes easy to corrode the metal, and if too small, the pot life at the time of applying the adhesive is shortened.

If necessary, the acrylic resin (A) used in the present invention may also contain other copolymerizable monomers (a4) appropriately in the polymerization component. Examples of the other copolymerizable monomer (a4) include acetacetyl group-containing monomers such as 2- (acetacetoxy) ethyl (meth) acrylate and arylacetate; (meth) glycidyl acrylate, (meth) Glycidyl group-containing monomers such as aryl glycidyl acrylate; vinyl ester monomers of carboxylic acids such as vinyl acetate, vinyl propionate, vinyl stearate, and vinyl benzoate; phenyl (meth) acrylate, benzyl (meth) acrylate, and phenoxy ethyl Monomers containing aromatic rings such as (meth) acrylate, phenyldiethylene glycol (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, styrene, and α-methylstyrene; biphenyloxy (Meth) acrylic acid ester monomers containing a biphenyloxy structure such as ethyl (meth) acrylate; ethoxymethyl (meth) acrylamide, n-butoxymethyl (meth) acrylamide, (meth) acryloylmorpholine, (Meth) acrylamide monomers such as dimethyl (meth) acrylamide, diethyl (meth) acrylamide, dimethylaminopropyl acrylamide, and (meth) acrylamide N-methylol (meth) acrylamide; 2-methoxyethyl (Meth) acrylate, 2-ethoxyethyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, polypropylene glycol Monomers containing alkoxy groups such as mono (meth) acrylate or oxyalkylene groups; acrylonitrile, methacryronitrile, vinyl chloride, vinylidene chloride, alkylvinyl ether, vinyltoluene, vinylpyridine, vinylpyrrolidone, Itaconic acid dialkyl ester, fumaric acid dialkyl ester, aryl alcohol, acrylic chloride, methyl vinyl ketone, aryl trimethylammonium chloride, dimethyl aryl vinyl ketone, etc. are mentioned. These may be used alone or in combination of two or more.

The content of the other copolymerizable monomer (a4) in the polymerization component is preferably 40% by weight or less, particularly preferably 30% by weight or less, and more preferably 25% by weight or less. When there are too many other copolymerizable monomers (a4), there exists a tendency for adhesive property to fall easily.

In the present invention, by polymerizing the (meth) acrylic acid alkyl ester-based monomer (a1), hydroxyl group-containing monomer (a2), carboxyl group-containing monomer (a3), and other copolymerizable monomer (a4) as necessary, ( Although a meta) acrylic-type resin (A) is produced, such a polymerization method can be suitably carried out by conventionally known methods such as solution radical polymerization, suspension polymerization, bulk polymerization, and emulsion polymerization. Especially, it is preferable from a viewpoint that it is safe and stably and can manufacture (meth) acrylic-type resin (A) with arbitrary monomer composition by manufacture by solution radical polymerization.

In the solution radical polymerization, in the organic solvent, for example, (meth) acrylic acid alkyl ester-based monomer (a1), hydroxyl group-containing monomer (a2), carboxyl group-containing monomer (a3) and other copolymerizable monomers (a4) as necessary. ) Or the like, and a polymerization initiator and a polymerization initiator are mixed or dropped, and polymerization can be performed at reflux or 50 to 98 ° C for about 0.1 to 20 hours.

Examples of the organic solvent used in the polymerization reaction include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, esters such as ethyl acetate and butyl acetate, n-propyl alcohol, and isopropyl alcohol. And ketones such as aliphatic alcohols, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

Examples of the polymerization initiator include azo-based polymerization initiators such as azobis isobutyronitrile and azobisdimethyl valeronitrile, which are common radical polymerization initiators, benzoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide and cumene hydride. Peroxide type polymerization initiators, such as loper oxide, etc. are mentioned as a specific example.

It is preferable that the acrylic resin (A) has a predetermined weight average molecular weight and a predetermined glass transition temperature.

The weight average molecular weight of the acrylic resin (A) is usually 100,000 to 2,000,000, preferably 150,000 to 1,500,000, particularly preferably 200,000 to 1,200,000, particularly preferably 300,000 to 1,000,000. When the weight average molecular weight is too small, the tendency of the contaminant of the member to be processed tends to increase, and if too large, the coatability tends to decrease or disadvantageous in terms of cost.

Moreover, the dispersion degree (weight average molecular weight / number average molecular weight) of the acrylic resin (A) is preferably 20 or less, particularly preferably 10 or less, further preferably 7 or less, and particularly preferably 5 or less. When the dispersion degree is too high, there is a tendency that the contamination of the member to be processed increases. In addition, the lower limit of the dispersion degree is usually 1.1 from the viewpoint of manufacturing limitations.

The above weight average molecular weight is the weight average molecular weight in terms of standard polystyrene molecular weight, and it is a high-speed liquid chromatograph (Japan Waters Corporation, "Waters 2695 (body)" and "Waters 2414 (detector)"), column: Shodex GPC KF -806L (Exclusion limit molecular weight: 2 × 10 ⁷ , Separation range: 100 to 2 × 10 ⁷ , Number of theoretical plates: 10,000 steps / piece, Filler material: Styrene-divinylbenzene copolymer, filler particle size: 10 μm) It is measured by using in series, the number average molecular weight can be used the same method. Moreover, the dispersion degree can be calculated | required by weight average molecular weight and number average molecular weight.

In addition, the glass transition temperature (Tg) of the acrylic resin (A) is preferably -80 to 50 ° C, particularly preferably -70 to 30 ° C and -50 to 20 ° C. If the glass transition temperature is too high, the adhesive tends to decrease, and if too low, the contamination of the member to be processed tends to increase.

In addition, the glass transition temperature is calculated by the following Fox equation.

That is, the glass transition temperature of the acrylic resin (A) is the value calculated by applying the glass transition temperature and weight fraction when each monomer constituting the acrylic resin (A) is a homopolymer to the formula of Fox.

In addition, the glass transition temperature when the monomer constituting the acrylic resin (A) is used as a homopolymer is usually measured by a differential scanning calorimeter (DSC), and is in accordance with JIS K 7121-1987 or JIS K 6240. Can be measured.

Moreover, it is preferable that the viscosity at 25 degreeC of the said acrylic resin (A) is 1,000-100,000 mPa * s, Especially preferably, it is 1,500-50,000 mPa * s. When such a viscosity is outside the said range, coating property tends to fall easily. In addition, the viscosity can be measured with an E-type viscometer.

[Urethane (meth) acrylate-based compound (B)]

The urethane (meth) acrylate-based compound (B) used in the present invention is a compound having a urethane bond and a (meth) acryloyl group.

The urethane (meth) acrylate-based compound (B) may be a urethane (meth) acrylate-based compound (B1) obtained by reacting a hydroxyl-containing (meth) acrylate-based compound (b1) and a polyvalent isocyanate-based compound (b2). It may be a urethane (meth) acrylate-based compound (B2) obtained by reacting a hydroxyl group-containing (meth) acrylate-based compound (b1), a polyvalent isocyanate-based compound (b2), and a polyol-based compound (b3). Especially, in this invention, it is preferable to use urethane (meth) acrylate type compound (B1) from a viewpoint of peelability after active energy ray irradiation.

Further, in the present invention, only one type of urethane (meth) acrylate-based compound (B) may be used, or two or more types may be used in combination.

As the hydroxyl group-containing (meth) acrylate-based compound (b1), it is preferable to have one hydroxyl group, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2 Hydroxyalkyl (meth) acrylates, such as -hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxyhexyl (meth) acrylate, 2-hydroxyethylacryloyl Phosphate, 2- (meth) acryloyloxyethyl 2-hydroxypropyl phthalate, caprolactone modified 2-hydroxyethyl (meth) acrylate, dipropylene glycol (meth) acrylate, fatty acid modified glycidyl (meth) Contains one ethylenically unsaturated group such as acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, 2-hydroxy-3- (meth) acrylooxypropyl (meth) acrylate The hydroxyl group-containing (meth) acrylate-based compound; Glycerin di (meth) acrylate, 2-hydroxy-3-acryloyl-oxypropyl methacrylate, and hydroxyl groups containing two ethylenically unsaturated groups (meth) Acrylate-based compounds; pentaerythritol tri (meth) acrylate, caprolactone-modified pentaerythritol tree (meth) acrylate, ethylene oxide-modified pentaerythritol tree (meth) acrylate, dipentaerythritol penta (meth) acrylate, caprolactone And hydroxyl group-containing (meth) acrylate-based compounds containing three or more ethylenically unsaturated groups such as modified dipentaerythritol penta (meth) acrylate and ethylene oxide-modified dipentaerythritol penta (meth) acrylate.

The hydroxyl group-containing (meth) acrylate-based compound (b1) can be used alone or in combination of two or more.

Among these, from the viewpoint of excellent reactivity and versatility, a hydroxyl group-containing (meth) acrylate-based compound containing three or more ethylenically unsaturated groups is preferable, and pentaerythritol tri (meth) acrylate or dipentaerythritolpenta (meth) acrylate Is particularly preferred.

As the polyvalent isocyanate-based compound (b2), for example, tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenyl methane diisocyanate, xylene diisocyanate, tetramethyl xylene diisocyanate, phenylenedi Aromatic polyisocyanates such as isocyanate and naphthalene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysinetyl tittyl titanate, and lysine triisocyanate; hydrogenated diphenylmethane diisocyanate, hydrogenated Alicyclic polyisocyanates such as xylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate and 1,3-bis (isocyanatmethyl) cyclohexane; or trimer compounds or multimer compounds of these polyisocyanates, allophanate Type polyisocyanate, burette-type polyisocyanate, water-dispersion-type polyisocyanate (for example, "Aquanate 100", "Aquanate 110", "Aquanate 200", "Aquanate 210" by Japanese Polyurethane High School) ) And the like.

Among these, from the viewpoint of excellent reactivity and versatility, aliphatic diisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate, isophorone diisocyanate , Norbornene diisocyanate, alicyclic diisocyanate such as 1,3-bis (isocyanatmethyl) cyclohexane is preferred, particularly preferably isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene di It is an isocyanate and hexamethylene diisocyanate, More preferably, it is an isophorone diisocyanate and hexamethylene diisocyanate.

The polyol-based compound (b3) may be a compound containing two or more hydroxyl groups, for example, aliphatic polyol, alicyclic polyol, polyether-based polyol, polyester-based polyol, polycarbonate-based polyol, polyolefin-based polyol, And polybutadiene-based polyols, polyisoprene-based polyols, (meth) acrylic-based polyols, and polysiloxane-based polyols.

Examples of the aliphatic polyols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, dimethylolpropane, neopentyl glycol, 2,2-diethyl-1,3-propanediol, and 2 -Butyl-2-ethyl-1,3-propanediol, 1,4-tetramethylenediol, 1,3-tetramethylenediol, 2-methyl-1,3-trimethylenediol, 1,5-pentamethylenediol, 1,6-hexamethylenediol, 3-methyl-1,5-pentamethylenediol, 2,4-diethyl-1,5-pentamethylenediol, pentaerythritol diacrylate, 1,9-nonanediol, 2 Aliphatic alcohols containing two hydroxyl groups such as -methyl-1,8-octane diol, sugar alcohols such as xylitol and sorbitol, and aliphatic alcohols containing three or more hydroxyl groups such as glycerin, trimethylolpropane, and trimethylolethane And the like. These may be used alone or in combination of two or more.

Examples of the alicyclic polyols include cyclo hexanediols such as 1,4-cyclohexanediol and cyclohexyl dimethanol, hydrogenated bisphenols such as hydrogenated bisphenol A, and tricyclodecane dimethanol. One type or two or more types can be used in combination.

Examples of the polyether-based polyols include polyether-based polyols containing alkylene structures such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, polypentamethylene glycol, and polyhexamethylene glycol. And random or block copolymers of polyalkylene glycols. These may be used alone or in combination of two or more.

Examples of the polyester-based polyols include polycondensation reaction products of polyhydric alcohols with polyhydric carboxylic acids; ring-opening polymerization products of cyclic esters (lactones); reactants with three kinds of components: polyhydric alcohols, polyhydric carboxylic acids, and cyclic esters, etc. Can be heard.

Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,4-tetramethylenediol, 1,3-tetramethylenediol, and 2-methyl-1,3 -Methylenediol, 1,5-pentamethylenediol, neopentyl glycol, 1,6-hexamethylenediol, 3-methyl-1,5-pentamethylenediol, 2,4-diethyl-1,5-pentamethylene And diols, glycerin, trimethylolpropane, trimethylolethane, cyclohexanediols (1,4-cyclohexanediol, etc.), bisphenols (such as bisphenol A), and sugar alcohols (such as xylitol and sorbitol).

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids such as malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, suberic acid, azeraic acid, sebacic acid, and dedecanedioic acid; 1,4- Alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, aromatic dicarboxylic acid such as paraphenylenedicarboxylic acid, trimellitic acid, etc. Can be.

Examples of the cyclic ester include propiolactone, β-methyl-δ-valerolactone, ε-caprolactone, and the like.

Examples of the polycarbonate-based polyol include a reaction product of a polyhydric alcohol and phosgene; a ring-opening polymerization product of a cyclic carbonate (such as alkylene carbonate), and the like.

Examples of the polyhydric alcohol include exemplary polyhydric alcohols in the description of the polyester-based polyol, and examples of the alkylene carbonate include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, and hexamethylene carbonate. Can be.

In addition, the polycarbonate-based polyol has a carbonate bond in the molecule, and may be a compound having a terminal hydroxyl group, or may have an ester bond together with the carbonate bond.

As said polyolefin type polyol, what has a homopolymer or copolymer, such as ethylene, propylene, butene, as a saturated hydrocarbon skeleton, and has a hydroxyl group at the molecular terminal.

As said polybutadiene type polyol, what has a copolymer of butadiene as a hydrocarbon skeleton, and has a hydroxyl group at the molecular terminal is mentioned.

The polybutadiene-based polyol may be a hydrogenated polybutadiene polyol in which all or part of the ethylenically unsaturated groups included in the structure are hydrogenated.

As said polyisoprene type polyol, what has a copolymer of isoprene as a hydrocarbon skeleton and has a hydroxyl group at the molecular terminal is mentioned.

The polyisoprene-based polyol may be a hydrogenated polyisoprene polyol in which all or part of the ethylenically unsaturated groups included in the structure are hydrogenated.

Examples of the (meth) acrylic polyol include those having (meth) acrylic acid esters having at least two hydroxyl groups in the polymer or copolymer molecule, and such (meth) acrylic acid esters include, for example, ( Methyl methacrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylic acid, disilyl (meth) acrylate, And (meth) acrylic acid alkyl esters such as (meth) acrylic acid dodecyl and (meth) acrylic acid octadecyl.

Examples of the polysiloxane-based polyol include dimethylpolysiloxane polyol, methylphenylpolysiloxane polyol, and the like.

Among these, aliphatic polyols and alicyclic polyols are preferably used from the viewpoint of cost, and polyester-based polyols, polyether-based polyols, and polycarbonate-based polyols are preferably used from the viewpoint of versatility.

The weight average molecular weight of the polyol-based compound (b3) is preferably 60 to 3,000, particularly preferably 100 to 1,000, and more preferably 150 to 800. If the weight-average molecular weight of the polyol-based compound (b3) is too large, the resulting urethane (meth) acrylate-based compound (B2) and the acrylic resin (A) are difficult to uniformly mix, and the tendency for residual glue to be processed to be easily generated There is this. Moreover, when the weight average molecular weight of the polyol-based compound (b3) is too small, cracks tend to easily occur in the pressure-sensitive adhesive layer after irradiation with active energy rays.

The urethane (meth) acrylate-based compound (B) can be produced by reacting the above-described components by known reaction means.

In general, when preparing a urethane (meth) acrylate-based compound (B1), the hydroxyl group-containing (meth) acrylate-based compound (b1) and the polyvalent isocyanate-based compound (b2), the urethane (meth) acrylate-based compound In the case of preparing (B2), the polyol-based compound (b3) can be prepared by urethanization reaction by a known reaction means by putting the polyol-based compound (b3) in a reactor or separately. Moreover, when manufacturing a urethane (meth) acrylate type compound (B2), the reaction product obtained by previously reacting a polyol type compound (b3) with a polyvalent isocyanate type compound (b2) contains a hydroxyl group-containing (meth) acrylate type The method of reacting the compound (b1) is useful from the viewpoint of stability of the urethanization reaction and reduction of by-products.

In the urethanization reaction described above, the reaction is terminated when the content of the residual isocyanate group in the reaction system becomes 0.5% by weight or less, whereby a urethane (meth) acrylate-based compound (B) is obtained.

Moreover, in the urethanization reaction, it is preferable to use a catalyst for the purpose of accelerating the reaction, and examples of such a catalyst include metal compounds, amino group-containing compounds, and the like.

Examples of the metal-based compound include dibutyltin dilaurate, dibutyltin diacetate, trimethyltin hydroxide, tetra-n-butyltin, bisacetylacetnate zinc, zirconium tris (acetylacetate) ethylacetate, Organometallic compounds such as zirconium tetraacetylacetate, tin octenate, zinc hexanate, zinc octenate, zinc stearate, zirconium 2-ethylhexanoate, cobalt naphthenate, stannous chloride, stannous chloride, potassium acetate, Bismuth nitrate, bismuth bromide, bismuth iodide, bismuth sulfide, and other organic bismuth compounds such as dibutyl bismuth dilaurate and dioctyl bismuth dilaurate; and bismuth salts of 2-ethylhexanoate, bismuth naphthenate, and isodecane Acid bismuth salt, neodecanoic acid bismuth salt, lauric acid bismuth salt, maleic acid bismuth salt, stearic acid bismuth salt, oleic acid bismuth salt, linoleic acid bismuth salt, bismuth acetate salt, bismutribisneodecanoate, bisalicylate bismuth salt, dimorphic asset And organic acid bismuth salts such as bismuth salts.

Examples of the amino group-containing compound include triethylamine, triethylenediamine, benzyldiethylamine, 1,4-diazabicyclo [2,2,2] octane, and 1,8-diazabicyclo [5,4 , 0] undecene, N, N, N ', N'-tetramethyl-1,3-butanediamine, N-methylmorpholine, N-ethylmorpholine and the like.

Among these catalysts, dibutyltin dilaurate and 1,8-diazabicyclo [5,4,0] undecene are very suitable. Moreover, these catalysts can be used alone or in combination of two or more.

In the urethanization reaction, an organic solvent that does not have a functional group reacting with an isocyanate group, for example, esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, aromatics such as toluene and xylene Organic solvents, such as, can be used.

Moreover, reaction temperature is 30 to 90 degreeC normally, Preferably it is 40 to 80 degreeC, and reaction time is 2 to 10 hours normally, Preferably it is 3 to 8 hours.

The urethane (meth) acrylate-based compound (B) used in the present invention preferably has 3 to 20 ethylenically unsaturated groups, more preferably 4 to 18, particularly preferably from the viewpoint of peelability after active energy ray irradiation. The number is 6-15.

If such an ethylenically unsaturated group has too many, the crosslinking density after active energy ray irradiation tends to be too large, and tends to easily occur cracks in the pressure-sensitive adhesive layer, and if too small, sufficient crosslinking density cannot be obtained. There is a tendency that the peelability tends to decrease.

The weight average molecular weight of the urethane (meth) acrylate-based compound (B) used in the present invention is preferably 500 to 10,000, particularly preferably 750 to 5,000, more preferably 1,000 to 4,000. If the weight average molecular weight is too large, the viscosity of the composition becomes high, and the urethane (meth) acrylate-based compound (B) and the acrylic-based resin (A) are difficult to uniformly mix, and the residual glue to the member to be processed tends to be easily generated. have. When the weight-average molecular weight is too low, the urethane (meth) acrylate-based compound (B) tends to bleed easily from the pressure-sensitive adhesive sheet and tends to easily generate residual glue.

In addition, the said weight average molecular weight is the weight average molecular weight by conversion of standard polystyrene molecular weight, and it is a column by a high-speed liquid chromatography graph (Showa Denko Corporation make, "Shodex GPC system-11 type"), column: Shodex GPC KF-806L ( Exclusion limit molecular weight: 2 × 10 ⁷ , Separation range: 100 to 2 × 10 ⁷ , Theoretical number: 10,000 units / piece, Filler material: Styrene-divinyl benzene copolymer, filler particle size: 10 μm) in series It can be measured by using.

The viscosity of the urethane (meth) acrylate-based compound (B) used in the present invention at 60 ° C is preferably 1,000 to 100,000 mPa · s, particularly preferably 1,500 to 50,000 mPa · s. When such a viscosity is outside the said range, coating property tends to fall easily. In addition, the viscosity can be measured with an E-type viscometer.

The urethane (meth) acrylate-based compound (B) obtained above usually contains at least one of a metal-based compound derived from a catalyst and an amino group-containing compound used for the purpose of promoting the urethanization reaction. Since the active energy ray-curable peelable pressure-sensitive adhesive composition containing the urethane (meth) acrylate-based compound (B) and the crosslinking agent (D) described later, the pot life tends to be shortened. For improvement, it is important to contain a small amount of acid groups (carboxyl groups) in the acrylic resin (A) as described above.

In addition, in the present invention, such urethane (meth) acrylate-based compound (B) has a remarkable effect when at least one of the metal-based compound and the amino group-containing compound is usually 1 to 1,000 ppm, particularly 5 to 500 ppm, by weight. Have

In the present invention, the content of the urethane (meth) acrylate-based compound (B) is preferably 25 to 100 parts by weight, more preferably 30 to 90 parts by weight, particularly preferably 100 parts by weight of the acrylic resin (A). Is 40 to 80 parts by weight. When the content of the urethane (meth) acrylate-based compound (B) is too small, the peelability after irradiation with active energy rays tends to decrease, and if too large, cracks tend to easily occur in the pressure-sensitive adhesive layer after irradiation with active energy rays. There is this.

(Active energy ray polymerization initiator (C))

As the active energy ray polymerization initiator (C), any radical may be generated by the action of light. For example, diethoxyacetphenone, 2-hydroxy-2-methyl-1-phenyl propan-1-one, benzyl Dimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenyl ketone, 1- [4- (2-hydroxyethoxy)- Phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino- Acetphenones such as 1- (4-morpholinophenyl) butanone, 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanol oligomer; benzoin and benzoin methyl ether , Benzoin such as benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether; benzophenone, o-benzoyl methyl benzoate, 4-phenylbenzophenone, 4-benzoyl-4＇-methyl-diphenyl sulfide, 3,3 ＇, 4,4＇-tetra (tert-butylperoxycarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1 -Oxo-2-propenyloxy) ethyl] benzenemethanium bromide, benzophenones such as (4-benzoylbenzyl) trimethylammonium chloride; 2-isopropyl thioxanthone, 4-isopropylthioxanthone, 2, 4-diethyl thioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxyxanthone, 2- (3-dimethyl amino-2-hydroxy) -3,4-dimethyl-9H -Thioxanthone-9-thioxanthones such as on-mesochloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl -Acyl phosphone oxides such as pentyl phosphine oxide, bis (2, 4, 6-trimethylbenzoyl)-phenyl phosphine oxide; and the like. Among them, acetphenones are preferred, and particularly preferably 1-hydroxycyclohexylphenylketone. In addition, these active energy ray polymerization initiators (C) may be used alone or in combination of two or more.

Moreover, as preparation of these active energy ray polymerization initiators (C), for example, triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (mihiraketone), 4,4'-diethylaminobenzophenone , 2-dimethylaminoethyl benzoate, 4-dimethylaminobenzoate, 4-dimethylaminobenzoate (n-butoxy) ethyl, 4-dimethylaminobenzoate isoamyl, 4-dimethylaminobenzoate 2-ethylhexyl, 2,4- Diethyl thioxanthone, 2,4-diisopropyl thioxanthone, etc. can also be used together. These preparations may be used alone or in combination of two or more.

The content of the active energy ray polymerization initiator (C) is preferably 0.1 to 20 parts by weight, particularly preferably 0.5 to 15 parts by weight, particularly preferably 1 to 10 parts by weight, relative to 100 parts by weight of the acrylic resin (A). Wealth.

When the content of the active energy ray polymerization initiator (C) is too small, the peelability after irradiation with active energy rays tends to decrease, and if too large, cracks tend to easily occur in the pressure-sensitive adhesive layer after irradiation with active energy rays.

〔Crosslinking system (D)〕

As said crosslinking agent (D), an isocyanate type crosslinking agent, an epoxy type crosslinking agent, an aziridine type crosslinking agent, an oxazoline type crosslinking agent, a melamine type crosslinking agent, an aldehyde type crosslinking agent, and an amine crosslinking agent are mentioned, for example. Among these, it is preferable to use an isocyanate-based crosslinking agent from the viewpoint of improving the adhesion to the substrate and reactivity with the acrylic resin (A).

Moreover, these crosslinking agents (D) may be used alone, or two or more of them may be used in combination.

Examples of the isocyanate crosslinking agent include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, and hexamethylene di Isocyanate, diphenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatmethyl) cyclohexane, tetramethylxylenediisocyanate, 1,5-naphthalenediisocyanate, triphenylmethanetri And an adduct of an isocyanate and a polyol compound such as trimethyrolpropane and the polyisocyanate compound, and a burette or isocyanurate body of these polyisocyanate compounds.

Among these, isocyanurate bodies of hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,4-tolylene diisocyanate, and 2,6-tolylene diisocyanate and trimethylol from the viewpoint of drug resistance and reactivity with functional groups The adduct of propane, 2,4-tolylene diisocyanate and the isocyanurate body of 2,6-tolylene diisocyanate, and the adduct body of tetramethylxylene diisocyanate and trimethylolpropane are preferred.

Examples of the epoxy-based crosslinking agent include bisphenol A epichlorohydrin type epoxy resins, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, and glycerin triglycidyl ether. , 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, diglycerol polyglycidyl Ether, 1,3'-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N'-tetraglycidyl-m-xylenediamine and the like.

Examples of the aziridine-based crosslinking agent include tetramethylolmethane-tri-β-aziridinylpropionate, trimethylolpropane-tri-β-aziridinylpropionate, N, N'-diphenylmethane- 4,4'-bis (1-aziridine carboxyamide), N, N'-hexamethylene 1,6-bis (1-aziridine carboxyamide), etc. are mentioned.

Examples of the oxazoline-based crosslinking agent include 2,2'-bis (2-oxazoline), 1,2-bis (2-oxazoline-2-yl) ethane, and 1,4-bis (2-oxa) Sleepy-2-yl) butane, 1,8-bis (2-oxazoline-2-yl) butane, 1,4-bis (2-oxazoline-2-yl) cyclohexane, 1,2-bis (2 Bisoxazoline compounds containing aliphatic or aromatic compounds such as -oxazoline-2-yl) benzene and 1,3-bis (2-oxazoline-2-yl) benzene, 2-vinyl-2-oxazoline, 2-vinyl 1 or 2 types of addition polymerizable oxazolines such as -4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline And the above polymers.

Examples of the melamine-based crosslinking agent include hexamethoxymethylmelamine, hexaethoxy methylmelamine, hexapropoxymethylmelamine, hexaputoxymethylmelamine, hexapentyloxymethylmelamine, hexahexyloxymethylmelamine, and melamine resin. Can be lifted.

Examples of the aldehyde-based crosslinking agent include glyoxal, malondialdehyde, succinaldehyde, maleindialdehyde, glutaldialdehyde, formaldehyde, acetaldehyde, and benzaldehyde.

Examples of the amine-based crosslinking agent include hexamethylenediamine, triethyldiamine, polyethyleneimine, hexamethylenetetraamine, diethylenetriamine, triethyltetraamine, isophoronediamine, amino resin, and polyamide. .

Content of the said crosslinking agent (D) is 0.1-30 weight part normally with respect to 100 weight part of acrylic resins (A), Preferably it is 0.5-20 weight part, More preferably, it is 1-15 weight part. If the crosslinking agent (D) is too small, the cohesive force of the pressure-sensitive adhesive decreases, and it tends to cause residual glue. If too much, the flexibility and adhesive force decrease, so that there is a tendency for excitation to occur between the members to be processed.

〔Other components〕

The active energy ray-curable peelable pressure-sensitive adhesive composition of the present invention is, for example, a small amount of a multifunctional monomer, a monofunctional monomer, an antistatic agent, an antioxidant, a plasticizer, a filler, a pigment, in a range that does not impair the effects of the present invention, It may also contain additives such as diluents, anti-aging agents, ultraviolet absorbers, ultraviolet stabilizers, and tackifying resins. These additives may be used alone or in combination of two or more. In particular, antioxidants are effective for maintaining the stability of the pressure-sensitive adhesive layer. The content of the antioxidant compound is not particularly limited, but is preferably 0.01 to 5% by weight. In addition, in addition to the additives, a small amount of impurities contained in the raw materials for the production of components of the active energy ray-curable peelable pressure-sensitive adhesive composition may be contained.

In this way, the active energy ray-curable peelable pressure-sensitive adhesive composition of the present invention is obtained.

In the present invention, the active energy ray-curable peelable pressure-sensitive adhesive composition containing the acrylic resin (A), urethane (meth) acrylate-based compound (B), active energy ray polymerization initiator (C) and crosslinking agent (D) is a crosslinking agent (D It is crosslinked with) to exhibit the performance as an adhesive, but after that, by irradiating active energy rays, the urethane (meth) acrylate-based compound (B) polymerizes to cure the adhesive, and the adhesive strength is lowered, resulting in peelability. Will be exerted.

The active energy ray-curable peelable pressure-sensitive adhesive composition of the present invention is usually an adhesive of a protective adhesive film for temporarily protecting a surface when processing a workpiece such as an electronic substrate, a semiconductor wafer, a glass processed product, a metal plate, a plastic plate, etc. It is preferably used as.

Hereinafter, the said adhesive film is demonstrated.

The adhesive film usually has a base sheet, an adhesive layer made of the active energy ray-curable peelable adhesive composition of the present invention, and a release film. As a method for producing such an adhesive film, first, the active energy ray-curable peelable pressure-sensitive adhesive composition of the present invention is directly coated on a release film or a base sheet by adjusting the concentration with an appropriate organic solvent. Thereafter, the adhesive film can be obtained by drying at 80 to 105 ° C for 0.5 to 10 minutes, for example, by heat treatment or the like and attaching it to the base sheet or release film. Moreover, in order to balance the adhesive properties, aging may be performed again after drying.

The viscosity of the active energy ray-curable peelable pressure-sensitive adhesive composition at 25 ° C is preferably 500 to 50,000 mPa · s, particularly preferably 1,000 to 25,000 mPa · s. When such a viscosity is outside the above range, the coatability tends to decrease. In addition, the viscosity can be measured with an E-type viscometer.

Examples of the base sheet include polyester resins such as polyethylene naphthalate, polyethylene terephthalate, polybutylene terephthalate, and polyethylene terephthalate / isophthalate copolymer; polyolefins such as polyethylene, polypropylene, and polymethylpentene. Resins; polyvinyl fluoride resins such as polyvinyl fluoride, polyvinylidene fluoride, and polyethylene fluoride; polyamides such as nylon 6 and nylon 6,6; polyvinyl chloride, polyvinyl chloride / vinyl acetate copolymer, ethylene-vinyl acetate Vinyl polymers such as copolymers, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, and vinylone; cellulose-based resins such as cellulose triacetate and cellophane; methyl polymethacrylate, ethyl polymethacrylate, ethyl polyacrylate, and butyl polyacrylate Acrylic resins such as polystyrene; Fabrics or non-woven fabrics made of sheets made of synthetic resins such as polycarbonate, polyarylate, and polyimide, metal foils of aluminum, copper, and iron, high-quality paper, glassine paper, glass fibers, natural fibers, and synthetic fibers. Can be. These base material sheets can be used as a single-layered body or as a multi-layered body in which two or more kinds are stacked. Among these, a sheet made of synthetic resin is preferred from the viewpoint of weight reduction and the like.

In addition, as the release film, for example, various synthetic resin sheets exemplified by the base sheet, paper, fabric, non-woven fabric or the like may be used.

Moreover, as a coating method of the said active-energy-ray-curable peelable adhesive composition, if it is a general coating method, it will not specifically limit, For example, methods, such as roll coating, die coating, gravure coating, comma coating, screen printing, are mentioned. .

The thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film is preferably 10 to 200 μm, and preferably 15 to 100 μm.

As the active energy ray, usually, ultraviolet rays, ultraviolet rays, near-ultraviolet rays, infrared rays, and other electromagnetic waves such as X-rays and γ-rays can be used, but electron beams, floton rays, neutron rays, etc. can be used. Curing by ultraviolet rays is advantageous from the ease of use, price, and the like.

The cumulative irradiation amount of the ultraviolet rays is usually 50 to 3,000 mJ / cm 2, preferably 100 to 1,000 mJ / cm 2. Further, the irradiation time varies depending on the type of the light source, the distance between the light source and the pressure-sensitive adhesive layer, the thickness of the pressure-sensitive adhesive layer, and other conditions, but may be a few seconds in some cases depending on the case for a few seconds.

Although the adhesive force of the said adhesive film differs depending on the kind of a base sheet, the kind of a to-be-processed member, etc., before active energy ray irradiation, 0.1-30 N / 25 mm is preferable, and 0.5-20 N / 25 mm is preferable. Moreover, the adhesive force after irradiation with active energy rays is preferably 0.01 to 1 N / 25 mm, and further preferably 0.05 to 0.5 N / 25 mm.

According to the active energy ray-curable peelable pressure-sensitive adhesive composition of the present invention, for example, the adhesive film used as the pressure-sensitive adhesive is bonded to the member to be processed to temporarily protect the surface of the member to be processed, and then, if necessary, the active energy ray By irradiating, the adhesive can be cured to lower the adhesive force and can be easily peeled from the member to be processed.

(Example)

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless the gist is exceeded. In addition, hereinafter, "%" and "part" means a basis of weight.

<Preparation of acrylic resin (A) solution>

[Acrylic resin (A-1)]

In a reactor equipped with a temperature controller, a thermometer, a stirrer, a dropping lot, and a reflux cooler, 29 parts of ethyl acetate was added, heated while stirring, and 77.3 parts of n-butylacrylate (a1) at a temperature stabilized at 78 ° C, methyl meta A mixture of 17.5 parts of acrylate (a1), 4 parts of 2-hydroxyethyl methacrylate (a2), 0.2 parts of acrylic acid (a3), and 0.037 parts of azobisisobutyronitrile (AIBN) was added dropwise over 2 hours. And reacted under reflux. Subsequently, 7 parts of ethyl acetate and 0.7 parts of 2-hydroxyethyl methacrylate (a2) were added 3 hours after the start of the reaction, and a solution in which 1.5 parts of ethyl acetate and 0.025 parts of AIBN were dissolved 3.5 hours after the start of the reaction was added. Further, 20 parts of toluene and 0.3 parts of 2-hydroxyethyl methacrylate (a2) were added 5 hours after the start of the reaction, and a solution in which 4 parts of toluene and 0.05 parts of AIBN was dissolved was added 5.5 hours after the start of the reaction. After 7.5 hours from the start of the reaction, 87.5 parts of ethyl acetate and 101 parts of toluene were added to terminate the reaction, and an acrylic resin (A-1) solution (weight average molecular weight 520,000, glass transition temperature -32 ° C, resin content 40%, viscosity 9,100) mPa · s (25 ° C.).

[Acrylic resin (A-2)]

In the acrylic resin (A-1), 64.85 parts of n-butylacrylate and 30 parts of methyl methacrylate as component (a1), 5 parts of 2-hydroxyethyl methacrylate as component (a2), (a3) component As the acrylic resin (A-1), except that 0.15 part of acrylic acid was used as the acrylic resin (A-2) solution (weight average molecular weight 480,000, glass transition temperature -17 ° C, resin content 40%, viscosity 12,400 mPa s (25 ° C)).

(Acrylic resin (A＇-1))

In the above acrylic resin (A-1), 81.9 parts of n-butylacrylate and 10 parts of methyl methacrylate as component (a1), 0.1 parts of 2-hydroxyethyl methacrylate as component (a2), (a3) component As the acrylic resin (A-1), except for using 8 parts of acrylic acid as the acrylic resin (A35-1) solution (weight average molecular weight 390,000 glass transition temperature -35 ° C, resin content 40%, viscosity 8,100 mPa S (25 ° C)).

[Acrylic resin (A＇-2)]

In the acrylic resin (A-1), 62 parts of n-butylacrylate and 10 parts of methyl methacrylate as components (a1) and 28 parts of 2-hydroxyethyl methacrylate as components (a2) were used (a3). Acrylic resin (A 수지 -2) solution (weight average molecular weight 620,000, glass transition temperature -34 ° C, resin content 40%, viscosity 6,600) in the same manner as acrylic resin (A-1), except that no component was used mPa · s (25 ° C.).

A urethane (meth) acrylate-based compound (B) was prepared as follows.

<Preparation of urethane (meth) acrylate-based compound (B)>

[Urethane Acrylate (B1-1)]

In a four-necked flask equipped with a temperature controller, thermometer, stirrer, water-cooling condenser, and nitrogen gas inlet, 6.6 parts of isophorone diisocyanate, mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 48mgKOH / g ) 93.4 parts, 0.06 parts of 2,6-di-tert-butylcresol as a polymerization inhibitor, 0.02 parts of dibutyltin dilaurate as a reaction catalyst, and reacted at 60 ° C to react when the remaining isocyanate group reaches 0.3% or less Was completed to obtain a mixture of urethane acrylate (B1-1) (weight average molecular weight 2,000). The content of the metal compound in this urethane acrylate (B1-1) was 200 ppm.

Next, each compounding component shown below was prepared.

[Active energy ray polymerization initiator (C-1)]

Irgacure 184 (manufactured by BASF)

〔Crosslinking system (D-1)〕

Coronate L-55E (isocyanate-based crosslinking agent, manufactured by Tosoh Corporation)

<Example 1>

(Preparation of adhesive composition)

100 parts of acrylic resin (A-1) solution obtained above (40 parts of resin content), 20 parts of urethane acrylate (B1-1), 1.4 parts of active energy ray polymerization initiator (C-1), crosslinking agent (D-1) Two parts, 30 parts of toluene as a diluting solvent were mixed to obtain an active energy ray-curable peelable pressure-sensitive adhesive composition.

〔Production of adhesive film〕

The obtained active energy ray-curable peelable pressure-sensitive adhesive composition was coated with an applicator on a reverse adhesive polyethylene terephthalate film (film thickness: 50 µm) (manufactured by Toraya, "Lumira T60") as a base sheet, and then applied to the adhesive layer. It dried at 3 degreeC for 3 minutes, adhered to a release film (made by Mitsui Chemical Co., Ltd., "SP-PET 3801-BU"), and aged at 40 degreeC for 3 days to obtain an adhesive film (25 mu m thickness of adhesive layer).

The following evaluation was performed using the obtained adhesive film.

〔Adhesive power: Before irradiation with ultraviolet rays〕

From the adhesive film obtained above, a test piece having a size of 25 mm × 100 mm was prepared, the release film was peeled off, and then a rubber roller having a mass of 2 kg was reciprocated and pressed twice under an atmosphere of 23 ° C. and a relative humidity of 50% on a stainless steel plate (SUS304BA plate). After sticking and leaving for 30 minutes under the same atmosphere, the peel strength at 180 degrees (N / 25 mm) was measured at a peel rate of 300 mm / min.

(Adhesive power: After irradiation with ultraviolet rays)

A test piece of 25 mm × 100 mm was prepared from the adhesive film obtained above, and after the release film was peeled off, the rubber plate having a mass of 2 kg was repeatedly reciprocated in a stainless steel plate (SUS304BA plate) at an atmosphere of 23 ° C. and a relative humidity of 50%. After standing for 30 minutes in the same atmosphere, ultraviolet irradiation (integrated irradiation amount of 200 mJ / cm 2) was performed at a conveyor speed of 5.1 m / min from a height of 18 cm using a lamp such as 80 W high-pressure mercury lamp. Further, after leaving for 30 minutes in an atmosphere of 23 ° C. and 50% relative humidity, the 180 ° peel strength (N / 25 mm) was measured at a peel rate of 300 mm / min.

〔Copper Corrosion〕

An adhesive film was attached to the copper plate on which the surface was polished and left for 3 days in an atmosphere of 85 ° C and a relative humidity of 85%. Discoloration of the copper plate after the test was visually confirmed. The evaluation criteria are as follows.

(Evaluation standard)

○ ··· There is no discoloration of copper plate at all

There is discoloration or corrosion of the copper plate.

[Port life: Viscosity change after preparation of adhesive composition]

100 parts of acrylic resin (A-1) solution, 20 parts of urethane acrylate (B1-1), 1.4 parts of active energy ray polymerization initiator (C-1), 2 parts of crosslinking agent (D-1), 30 parts of toluene as dilution solvent The adhesive composition was prepared by mixing. And the viscosity at 25 degreeC from immediately after preparation of this adhesive composition to 24 hours later was measured over time using the E-type viscometer. The evaluation criteria are as follows.

(Evaluation standard)

○ ··· [Viscosity after 24 hours of preparation] / [Viscosity immediately after preparation] = less than 3, the blending solution after 24 hours is transparent

Δ ··· [Viscosity after 24 hours of preparation] / [Viscosity immediately after preparation] = less than 3, but the blending solution after 24 hours becomes cloudy

× ··· [Viscosity after 24 hours of preparation] / [Viscosity immediately after preparation] = 3 or more

<Example 2>

An active energy ray-curable peelable pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, except that an acrylic resin (A-2) solution was blended in place of the acrylic resin (A-1) solution, and evaluated in the same manner as in Example 1. Conducted.

<Example 3>

An active energy ray-curable peelable pressure-sensitive adhesive composition was obtained in the same manner as in Example 2 except that 12 parts of urethane acrylate (B1-1) were used, and the same evaluation as in Example 1 was performed.

<Comparative Example 1>

An active energy ray-curable peelable pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, except that an acrylic resin (A＇-1) solution was blended in place of the acrylic resin (A-1) solution, and the same evaluation as in Example 1 was obtained. Conducted.

<Comparative Example 2>

An active energy ray-curable peelable pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except that an acrylic resin (A＇-2) solution was blended in place of the acrylic resin (A-1) solution, and the same evaluation as in Example 1 was obtained. Conducted.

Table 1 shows the evaluation results of Examples and Comparative Examples. In addition, Table 2 below shows the aging change of the viscosity after preparing the adhesives of Examples and Comparative Examples.

The active energy ray-curable peelable pressure-sensitive adhesive compositions of Examples 1 to 3 were excellent in pot life. In addition, the adhesive films using the active energy ray-curable peelable pressure-sensitive adhesive compositions of Examples 1 to 3 had no corrosiveness to the copper plate, and the adhesive strength before and after ultraviolet irradiation was also good.

On the other hand, the active energy ray-curable peelable pressure-sensitive adhesive composition of Comparative Example 1 in which the amount of carboxyl group-containing monomers in the polymerization component of the acrylic resin (A) was greater than a specific range was inferior in pot life. In addition, the adhesive film using the active energy ray-curable peelable pressure-sensitive adhesive composition of Comparative Example 1 had corrosive properties to the copper plate, so that the adhesive force before ultraviolet irradiation was high and was not suitable for practical use.

In addition, the active energy ray-curable peelable pressure-sensitive adhesive composition of Comparative Example 2, which does not contain a carboxyl group-containing monomer in the polymerization component of the acrylic resin (A), was cured at 3 hours after preparation, resulting in a very short pot life.

Although the specific form in this invention was shown in the said Example, the said Example is only a mere illustration and is not interpreted limitedly. Various modifications apparent to those skilled in the art are expected to be within the scope of the present invention.

The active energy ray-curable peelable pressure-sensitive adhesive composition of the present invention can be suitably used for temporary surface protection adhesive films when processing electronic substrates, semiconductor wafers, glass processed products, metal plates, plastic plates, and the like.

Claims (8)

In an active energy ray-curable peelable pressure-sensitive adhesive composition containing an acrylic resin (A), a urethane (meth) acrylate-based compound (B), an active energy ray polymerization initiator (C) and a crosslinking agent (D), the acrylic resin (A ) Is an acrylic resin obtained by polymerizing polymerization components including (meth) acrylic acid alkyl ester-based monomer (a1), hydroxyl group-containing monomer (a2), and carboxyl group-containing monomer (a3), wherein the content ratio of the carboxyl group-containing monomer (a3) is Active energy ray-curable peelable pressure-sensitive adhesive composition, characterized in that 0.01 to 0.4% by weight of the polymerization component. The method according to claim 1,
The urethane (meth) acrylate-based compound (B), the active energy ray-curable release pressure-sensitive adhesive composition, characterized in that it contains at least one of the metal-based compound and the amino group-containing compound, 1 to 1,000 ppm by weight. The method according to claim 1 or 2,
The urethane (meth) acrylate-based compound (B) has an ethylenically unsaturated group, the active energy ray-curable peelable pressure-sensitive adhesive composition, characterized in that the number of ethylenically unsaturated groups is 3 to 20. The method according to any one of claims 1 to 3,
The urethane (meth) acrylate-based compound (B) is a reactant of a hydroxyl group-containing (meth) acrylate-based compound (b1) and a polyvalent isocyanate-based compound (b2) containing three or more ethylenically unsaturated groups in the molecule. Energy ray curable peelable pressure-sensitive adhesive composition. The method according to any one of claims 1 to 4,
The urethane (meth) acrylate-based compound (B) has an active energy ray-curable peelable pressure-sensitive adhesive composition, characterized in that the weight average molecular weight of 500 to 10,000. The method according to any one of claims 1 to 5,
The active energy ray-curable peelable pressure-sensitive adhesive composition, characterized in that the acrylic resin (A) has a weight average molecular weight of 100,000 to 2,000,000 and a glass transition point temperature of -80 to 50 ° C. The method according to any one of claims 1 to 6,
The content of the urethane (meth) acrylate-based compound (B) is an active energy ray-curable peelable pressure-sensitive adhesive composition, characterized in that 25 to 100 parts by weight based on 100 parts by weight of the acrylic resin (A). The method according to any one of claims 1 to 7,
Active energy ray-curable peelable pressure-sensitive adhesive composition, characterized in that it is used in the pressure-sensitive adhesive of a protective adhesive film for temporarily protecting the surface.