JP2007238853A - Adhesive composition and adhesive film produced by using the adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive film having excellent reworkability, free from foaming and floating/peeling troubles at the adhesive interface and light-leakage phenomenon even by the exposure to a high-temperature or high-temperature and humidity environment after pasting to an adherend, and generating no cracks at the peripheral part of an optical film and provide an adhesive composition capable of forming the adhesive film. <P>SOLUTION: The adhesive composition contains (C) a copolymer defined below and having hydroxyl group and/or carboxyl group and a glass transition temperature of -60 to 0°C and (D) an ethyleneimine hardener. The copolymer C contains (A) a high molecular weight copolymer composed of (a) an alkyl methacrylate free from substituent, (b) an alkyl acrylate free from substituent and (c) other monomer and having a specific weight-average molecular weight and glass transition temperature and (B) a low molecular weight copolymer at an (A)/(B) ratio of 65/35 to 85/15 in terms of the areal ratio in GPC measurement. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pressure-sensitive adhesive composition and a pressure-sensitive adhesive film using the pressure-sensitive adhesive composition. Specifically, the present invention relates to a pressure-sensitive adhesive composition suitably used when an optical film is attached to an adherend such as glass. More specifically, after sticking, even if placed under high temperature or under high temperature and high humidity, cracks (occurring in a state where extremely small bubbles are connected in streaks at the peripheral edge of the optical film. , Or the state thereof) relates to a pressure-sensitive adhesive composition that can form a pressure-sensitive adhesive film.

In recent years, display devices have been used in household and commercial appliances such as electronic computers, electronic watches, mobile phones, and televisions, in-vehicle devices, etc., and there are many opportunities to be used under various and severe conditions. ing. And various optical films, such as a polarizing film and a phase difference film, are used for the display member which comprises these display apparatuses.
Various optical films such as a polarizing film and a retardation film are attached to glass or other optical films as adherends using an adhesive composition. Once a defect is found in the adhered state after being adhered to the adherend, the polarizing film or retardation film is peeled off from the glass or the like, and a new polarizing film or retardation film is adhered. This “re-paste” is called rework. During rework, it is required that the adhesive layer does not remain on the adherend surface.

  By the way, the polarizing film is a state in which a polyvinyl alcohol film dyed with a pigment is sandwiched between a triacetyl cellulose-based protective film and a cycloolefin-based protective film. Polarizing films have poor dimensional stability due to the properties of these materials. In particular, under high temperature or high temperature and high humidity conditions, the dimensional change due to film shrinkage is severe.

When a laminate composed of an optical film / adhesive layer / adhered body is placed under high temperature or high temperature / humidity conditions and the dimensions of the optical film change, bubbles are generated at the adhesive interface between the adhesive layer and the adherend. (Foaming), the optical film is lifted from the adherend and peeled off.
By adjusting the molecular weight of the main component of the pressure-sensitive adhesive composition used and the degree of crosslinking of the pressure-sensitive adhesive composition and increasing the adhesive strength, it resists changes in the dimensions of the optical film and foams, floats and peels even in harsh environments. Attempts have been made to prevent this from occurring.

  However, if an attempt is made to resist the dimensional change of the optical film simply by increasing the adhesive strength, the stress distribution due to the dimensional change of the optical film that occurs under high temperature or high temperature and high humidity conditions becomes non-uniform, and the optical film Concentrate on the four corners or on the peripheral edges. As a result, when the optical film is a polarizing film used in a liquid crystal display device, there is a problem that a so-called light leakage phenomenon occurs in which light leaks from the four corners and peripheral edges of the liquid crystal display device.

  Therefore, even under harsh conditions, it is an adhesive composition for adhering optical films that does not cause foaming at the interface with the adherend and does not float or peel off. Adhesive compositions have been proposed.

  For example, 90% to 99.8% by weight of an alkyl (meth) acrylate monomer (a) is copolymerized with 0.2 to 10% by weight of a carboxyl group and / or hydroxyl group-containing unsaturated monomer (b). The weight average molecular weight is 30,000 to 300,000, which is obtained by copolymerizing a monomer mixture comprising the copolymers (A), (a) and (b) having a weight average molecular weight of 1,000,000 to 2,000,000. Copolymer (B) containing less than 2 (b) per molecule of polymer, weight average molecular weight of 1,000 to 20,000, and dispersity (MW / MN) of 1.0 to 2. An adhesive composition comprising an alkyl (meth) acrylate copolymer (C) having no functional group 5 and a curing agent (D) is known (see Patent Document 1).

  Furthermore, 100 parts by weight (A) of a copolymer having a weight average molecular weight of 500,000 to 2,000,000 based on an alkyl (meth) acrylate monomer and a carboxyl group and / or a hydroxyl group-containing unsaturated monomer as a main component; A copolymer composition (B) comprising 1 to 45 parts by weight of a copolymer having a weight average molecular weight of 1000 to 300,000 having an alkyl (meth) acrylate monomer as a main component. An acrylic pressure-sensitive adhesive composition containing a crosslinking agent (C) so that the number of theoretical crosslinking points per molecular chain is 2 to 10 is known (see Patent Document 2).

  Furthermore, a pressure-sensitive adhesive composition comprising an alkyl (meth) acrylate copolymer, an antioxidant and a curing agent, in which the gel fraction of the pressure-sensitive adhesive composition is adjusted to 30% to 60% has been proposed ( (See Patent Document 3).

  Furthermore, with respect to 100 parts by weight of the copolymer having a weight average molecular weight of 1,000,000 to 2,000,000, which is obtained by radical copolymerization of a monomer having a reactive functional group and another monomer, 20 to 100 parts by weight of a copolymer having a weight average molecular weight of 10,000 to 100,000, obtained by radical copolymerization of a monomer having a carboxyl group and other monomers in the presence of the copolymer, and the copolymer Adhesive composition comprising 0.003 to 3 parts by weight of a polyfunctional compound having at least two reactive functional groups capable of reacting with the polymer (A) and / or the copolymer, and an adhesive comprising the adhesive composition An optical member in which a layer is formed on at least one surface of the optical member has been proposed (for example, Patent Document 4).

Furthermore, as a resin component, (A) (meth) acrylic acid ester homopolymer or copolymer having a weight average molecular weight of 500,000 to 2,000,000, and (B) (meth) acrylic acid having a weight average molecular weight of 5,000 or more and less than 500,000. An ester homopolymer or a copolymer in a weight ratio of 100: 1 to 100: 50, and at least one of the component (A) and the component (B) is a nitrogen-containing functional group in the molecule. A pressure-sensitive adhesive composition that is a (meth) acrylic acid ester copolymer having a water content has been proposed (Patent Document 5).
Specifically, Example 5 of Patent Document 5 includes 100 parts by weight of a copolymer having a weight average molecular weight of 700,000 obtained by copolymerizing n-butyl acrylate / acrylic acid / acrylamide, and n-butyl acrylate / A pressure-sensitive adhesive composition containing 30 parts by weight of a copolymer having a weight average molecular weight of 300,000 obtained by copolymerizing methyl methacrylate at 95/15 (parts by weight) is described (see Patent Document 5).

Furthermore, an adhesive layer containing a (meth) acrylic resin and a dye is provided on one surface of the light-transmitting film, and the (meth) acrylic resin has a weight average molecular weight of 200,000 or more and a weight average A film with a colored pressure-sensitive adhesive composition for electronic displays, which is composed of at least a low molecular weight material having a molecular weight of less than 200,000 and has a functional group, has been proposed (see Patent Document 6).
Specifically, Examples 1 to 4 of Patent Document 6 include a high molecular weight material having a weight average molecular weight of about 1,000,000 and a glass transition temperature of about −49 ° C. obtained by copolymerization of n-butylarylate / acrylic acid, A pressure-sensitive adhesive composition containing a low molecular weight material having a weight average molecular weight of about 20,000 and a glass transition temperature of about 104 ° C. obtained by copolymerization of methyl methacrylate / acrylic acid at 99/1 (parts by weight) is described.

Further, it is a copolymer of alkyl (meth) acrylate and 0.5 to 20% by weight of a polymerizable monomer having functionality with respect to a crosslinking agent, and a high molecular weight (meth) having a weight average molecular weight of 1 million or more. 100 parts by weight of an acrylic copolymer, 20 to 200 parts by weight of a low molecular weight (meth) acrylic copolymer having a weight average molecular weight of 30,000 or less, and at least two functional groups capable of forming a crosslinked structure in the molecule The functional group distribution ratio represented by the functional group of the low molecular weight (meth) acrylic copolymer / functional group of the high molecular weight (meth) acrylic copolymer comprising 0.005 to 5 parts by weight of the polyfunctional compound Has been proposed (Patent Document 7). An adhesive composition for polarizing plates in which is in the range of 0 to 15% by weight, and a polarizing plate having an adhesive layer formed from the adhesive composition.
Specifically, Example 1 and Comparative Example 3 of Patent Document 7 include 100 parts by weight of a high molecular weight copolymer having a weight average molecular weight of about 1,500,000 obtained by copolymerization of n-butyl acrylate / acrylic acid, n -150 parts by weight of a low molecular weight copolymer having a weight average molecular weight of about 10,000 or a weight average molecular weight of about 50,000 obtained by copolymerizing butyl allylate / methyl methacrylate / acrylamide at 65/30/5 (parts by weight) An adhesive composition containing is described.

Even if the adhesive film formed using the adhesive composition described in Patent Documents 1 to 7 is attached to an adherend for a long period of time under high temperature or high temperature and high humidity, Foaming does not occur at the sticking interface, neither floating nor peeling occurs, and no light leakage phenomenon occurs.
However, the adhesive films formed using the adhesive compositions described in Patent Documents 1 to 7 are all optical when exposed to a harsh environment as described above for a long time after being attached to an adherend. Extremely small bubbles are generated in a streak-like state at the peripheral edge of the film. This phenomenon is called a “crack” because very small bubbles that appear as streaks look like a kind of crack.
Once attached to an adherend, the adhesive film that constitutes a display device, even after being exposed to a harsh environment for a long time, causes obvious foaming and floating / peeling at portions other than the peripheral edge of the film. If the light leakage phenomenon does not occur, it was considered good. However, as the various demands for display devices increase today, the durability level is no exception, and it is no longer sufficient that foaming, floating / peeling, and light leakage do not occur. That is, once crack generation has not been regarded as a problem, in recent years it has also been required that cracks do not occur.
JP 2003-49141 A JP 2003-349090 A JP 2003-49143 A JP 2004-331697 A JP 2001-89731 A JP 2002-372619 A JP-A-10-279907

  The object of the present invention is excellent in reworkability, and after sticking an adhesive film to an adherend, even if it is exposed to high temperature or high temperature and high humidity for a long period of time, foaming does not occur at the sticking interface, and it does not float or peel off. It is an object of the present invention to provide a pressure-sensitive adhesive film that does not cause a light leakage phenomenon and does not cause cracks at the peripheral edge of an optical film, and a pressure-sensitive adhesive composition that can form the pressure-sensitive adhesive film.

The present invention is a pressure-sensitive adhesive composition containing the following copolymer (C) having a hydroxyl group and / or a carboxyl group and having a glass transition temperature of −60 to 0 ° C. and an ethyleneimine curing agent (D). And
The copolymer (C) is
Alkyl methacrylate having no substituent (a): 15 to 35% by weight, alkyl acrylate (b) having no substituent and other ethylenically unsaturated double bonds copolymerizable with the above (a) and (b) A monomer comprising the monomer (c) having a radical copolymerization (provided that the total of (a) to (c) is 100% by weight);
A high molecular weight copolymer (A) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B) composed of polymer molecules having a molecular weight of less than 100,000,
In gel permeation chromatography, the area ratio of the high molecular weight copolymer (A) to the low molecular weight copolymer (B) is (A) / (B) = 65/35 to 85/15. ,
The weight average molecular weight of the high molecular weight copolymer (A) is 500,000 to 2,200,000, the glass transition temperature is −60 to 0 ° C., the weight average molecular weight of the low molecular weight copolymer (B) is 1,000 to 100,000, and the glass transition temperature. It is related with the adhesive composition characterized by being -60-20 degreeC.

Moreover, this invention has a hydroxyl group and / or a carboxyl group, and the adhesive composition containing the following copolymer (C) whose glass transition temperature is -60-0 degreeC, and an ethyleneimine type hardening | curing agent (D). Because
The copolymer (C) is
Alkyl methacrylate having no substituent (a): 15 to 35% by weight, alkyl acrylate (b) having no substituent and other ethylenically unsaturated double bonds copolymerizable with the above (a) and (b) The monomer comprising the monomer (c) is radically copolymerized until the polymerization conversion is 65 to 85% to obtain a copolymer having a weight average molecular weight of 500,000 to 2,200,000, and then the above (a ) (B) and another monomer (c) having an ethylenically unsaturated double bond copolymerizable with (b), and further radically copolymerized until the polymerization conversion becomes 80 to 100% [however, The total of (a) to (c) is 100% by weight],
A high molecular weight copolymer (A) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B) composed of polymer molecules having a molecular weight of less than 100,000,
In gel permeation chromatography, the area ratio of the high molecular weight copolymer (A) to the low molecular weight copolymer (B) is (A) / (B) = 65/35 to 85/15. ,
The weight average molecular weight of the high molecular weight copolymer (A) is 500,000 to 2,200,000, the glass transition temperature is −60 to 0 ° C., the weight average molecular weight of the low molecular weight copolymer (B) is 1,000 to 100,000, and the glass transition temperature. It is related with the adhesive composition characterized by being -60-20 degreeC.

Furthermore, the present invention relates to an alkyl methacrylate (a) having no substituent: 15 to 35% by weight, an alkyl acrylate (b) having no substituent, and other ethylenic copolymers copolymerizable with the above (a) and (b). A monomer comprising the monomer (c) having a saturated double bond is radically copolymerized until the polymerization conversion becomes 65 to 85% to obtain a copolymer having a weight average molecular weight of 500,000 to 2,200,000. Then, another monomer (c) having another ethylenically unsaturated double bond copolymerizable with the above (a) and (b) is added, and further radical copolymerization is carried out until the polymerization conversion becomes 80 to 100%. [However, the total of (a) to (c) is 100% by weight],
Including a high molecular weight copolymer (A) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B) composed of polymer molecules having a molecular weight of less than 100,000, and having a hydroxyl group and / or a carboxyl group, A copolymer (C) having a glass transition temperature of −60 to 0 ° C.,
In gel permeation chromatography, the area ratio of the high molecular weight copolymer (A) to the low molecular weight copolymer (B) is (A) / (B) = 65/35 to 85/15. ,
The weight average molecular weight of the high molecular weight copolymer (A) is 500,000 to 2,200,000, the glass transition temperature is −60 to 0 ° C., the weight average molecular weight of the low molecular weight copolymer (B) is 1,000 to 100,000, and the glass transition temperature. To obtain a copolymer (C) having a temperature of -60 to 20 ° C,
Next, the present invention relates to a method for producing an adhesive composition, wherein an ethyleneimine curing agent (D) is added to the copolymer (C).

  Further, the present invention is an optical film wherein the pressure-sensitive adhesive composition described in the above invention or the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition obtained by the above production method is selected from the group consisting of a polarizing film and a retardation film. It is related with the adhesive film characterized by being provided in at least one surface.

  The pressure-sensitive adhesive composition of the present invention has excellent reworkability, and after sticking the pressure-sensitive adhesive film to an adherend, even if it is exposed to high temperature or high temperature and high humidity for a long time, foaming does not occur at the sticking interface, It has become possible to provide an adhesive film that not only does not peel off and does not cause light leakage, but also does not crack at the peripheral edge of the optical film.

The copolymer (C) used in the pressure-sensitive adhesive composition of the present invention is a main component of the pressure-sensitive adhesive composition, and forms a pressure-sensitive adhesive layer by reacting with the ethyleneimine curing agent (D) described later.
The copolymer (C) has a hydroxyl group and / or a carboxyl group, and its glass transition temperature (hereinafter referred to as “Tg”) is −60 to 0 ° C. The copolymer (C) comprises an alkyl methacrylate (a) having no substituent, an alkyl acrylate (b) having no substituent, and other ethylenically unsaturated diacids copolymerizable with the above (a) and (b). The monomer is composed of the monomer (c) having a heavy bond, and contains a high molecular weight copolymer (A) and a low molecular weight copolymer (B). In the present invention, in gel permeation chromatography (hereinafter referred to as “GPC”), a copolymer component composed of polymer molecules having a molecular weight of 100,000 or more with a molecular weight of 100,000 as a boundary is converted into a high molecular weight copolymer (A ), A copolymer component composed of polymer molecules having a molecular weight of less than 100,000 is defined as a low molecular weight copolymer (B).

The alkyl methacrylate (a) having no substituent that constitutes the copolymer (C) used in the present invention means an alkyl methacrylate having no functional group such as a hydroxyl group or a carboxyl group. It may be linear, may have a branched structure, or may have a cyclic structure.
Examples of the alkyl methacrylate (a) having no substituent include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-pentyl methacrylate, 2-ethylhexyl methacrylate, n-hexyl methacrylate, n-heptyl methacrylate, and n-octyl. Examples include methacrylate, isooctyl methacrylate, n-nonyl methacrylate, n-decyl methacrylate, undecyl methacrylate, and dodecyl methacrylate. These may be used alone or in appropriate combination of two or more.

The alkyl acrylate (b) having no substituent that constitutes the copolymer (C) used in the present invention means an alkyl acrylate having no functional group such as a hydroxyl group or a carboxyl group. It may be linear, may have a branched structure, or may have a cyclic structure.
Examples of the alkyl acrylate (b) having no substituent include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, n-pentyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate, n-heptyl acrylate, n-octyl. Examples include acrylate, isooctyl acrylate, n-nonyl acrylate, decyl acrylate, undecyl acrylate, and dodecyl acrylate.

  The other monomer (c) having an ethylenically unsaturated double bond that can be copolymerized with the above (a) and (b), which is used for constituting the copolymer (C), is a copolymer ( In addition to the monomer (c1) having a hydroxyl group and / or a carboxyl group and having an ethylenically unsaturated double bond, which is used for introducing a hydroxyl group or a carboxyl group into C), other than the hydroxyl group and the carboxyl group And a monomer (c2) having an ethylenically unsaturated double bond, and another monomer (c3) having an ethylenically unsaturated double bond that is not classified as any of the above monomers. Can be mentioned.

As the monomer (c1) having a hydroxyl group and an ethylenically unsaturated double bond, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxy Butyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12 -Hydroxylauryl (meth) acrylate, caprolactone modified (meth) acrylates, polyethylene glycol (meth) acrylates, polypropylene glycol (meth) acrylates and the like.
Note that “2-hydroxyethyl (meth) acrylate” is an abbreviation of “2-hydroxyethyl acrylate” and “2-hydroxyethyl methacrylate”. Others are the same.

  As the monomer (c1) having a carboxyl group and an ethylenically unsaturated double bond, acrylic acid, methacrylic acid, β-carboxyethyl acrylate, itaconic acid, maleic acid, maleic anhydride, crotonic acid, fumaric acid, anhydrous Examples include fumaric acid.

  Monomers (c2) having other substituents and ethylenically unsaturated double bonds that can be used in combination with the monomer (c1) having a hydroxyl group and / or a carboxyl group and having an ethylenically unsaturated double bond ) Is a monomer having at least one substituent selected from the group consisting of an amino group, an amide group, a maleimide group, an itaconimide group, a nucleenimide group and an epoxy group, and an ethylenically unsaturated double bond. Can be mentioned.

  As the monomer (c2) having an amino group and an ethylenically unsaturated double bond, aminomethyl (meth) acrylate, dimethylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) An acrylate etc. are mentioned.

  Examples of the monomer (c2) having an amide group and an ethylenically unsaturated double bond include (meth) acrylamide, N-acryloylmorpholine, N-substituted (meth) acrylamide, N-vinylpyrrolidone and the like.

  Examples of the monomer (c2) having a maleimide group and an ethylenically unsaturated double bond include N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide and the like.

  As the monomer (c2) having an itacimide group and an ethylenically unsaturated double bond, N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexyl Itaconimide, N-cyclohexyl leuconconimide, N-lauryl itaconimide and the like can be mentioned.

  As the monomer (c2) having a nucleenimide group and an ethylenically unsaturated double bond, N- (meth) acryloyloxymethylene nucleenimide, N- (meth) acryloyl-6-oxyhexamethylene nucleenimide, N -(Meth) acryloyl-8-oxyoctamethylene nucleimide is exemplified.

  Examples of the monomer (c2) having an epoxy group and an ethylenically unsaturated double bond include glycidyl (meth) acrylate.

  Other monomers (c3) having no ethylenically unsaturated double bond, which are not classified as any of the above monomers, are vinyl monomers such as styrene, methylstyrene, vinyltoluene, vinyl acetate, Examples thereof include divinyl monomers such as divinylbenzene, and phosphate group-containing monomers such as 2-hydroxyethylacryloyl phosphate.

When the total of the monomers (a), (b) and (c) used for forming the copolymer (C) is 100% by weight, the amount of the alkyl methacrylate (a) having no substituent is 15 to 35. It is important to be weight percent. And it is important that Tg of the copolymer (C) used for this invention is -60-0 degreeC, and it is preferable that it is -55-5 degreeC.
In general, the main component for forming the adhesive layer needs to have a Tg in the minus region. Therefore, in the case of a general acrylic pressure-sensitive adhesive composition, in order to reduce the Tg of the acrylic copolymer contained in the composition, an alkyl acrylate having no substituent as a monomer constituting the acrylic copolymer (b In order to control Tg, alkyl methacrylate (a) having no substituent, which is a component that raises Tg, is not used at all or is used. Only very small amounts are used.
Also in the present invention, in order for Tg of the copolymer (C) to be −60 to 0 ° C., the monomer used for the formation of the copolymer (C) is quantitatively substituted. It is necessary that the alkyl acrylate (b) not having a main component is a main component.
However, when there are too many alkyl acrylates (b) which do not have a substituent, the flexibility of the main chain of the copolymer formed will become too high. As a result, the pressure-sensitive adhesive layer formed by the reaction between such a copolymer and the curing agent (D) described later is excessively softened at high temperature or high temperature and high humidity. When exposed to a high temperature or a high temperature and high humidity for a long time after wearing, cracks occur at the peripheral edge of the optical film as the substrate.

In the case of a general acrylic pressure-sensitive adhesive composition, an alkyl methacrylate (a) having no substituent, which is not used at all, or even if used, is used in a very small amount to control Tg. In the present invention, it is very important to use a large amount of 15 to 35% by weight as compared with the conventional acrylic pressure-sensitive adhesive.
That is, the presence of the methyl group of the alkyl methacrylate (a) having no substituent increases the steric hindrance of the main chain of the copolymer (C) to be formed, and the translation, vibration, and rotational motion of the main chain are suppressed. The As a result, even if the adhesive film is attached to the adherend, even if the adhesive film is exposed to a high temperature or a high temperature and high humidity for a long period of time, an effect that no crack is generated at the peripheral edge of the optical film as the substrate is exhibited.
When the alkyl methacrylate (a) having no substituent is less than 15 parts by weight, the translation, vibration, and rotational motion of the main chain become too large, so that it cannot withstand the harsh environment as described above and is a base material. Cracks occur at the peripheral edge of the optical film.
On the other hand, if the alkyl methacrylate (a) having no substituent exceeds 35% by weight, the translation, vibration, and rotation of the main chain are excessively suppressed, so that the adhesive layer becomes rigid. When the optical film as the substrate changes in dimensions due to the harsh environment as described above, the rigid adhesive layer resists the dimensional change too much, and the resistance force concentrates on the peripheral edge of the optical film as the substrate. , Light leakage at the peripheral edge will occur.

  Further, as described above, it is important that the Tg of the copolymer (C) is −60 to 0 ° C. When Tg is lower than −60 ° C., a crack occurs at the peripheral edge of the optical film as the base material.

  Moreover, a copolymer (C) needs to have a hydroxyl group and / or a carboxyl group as a functional group for reacting with the ethyleneimine type hardening | curing agent (D) mentioned later. The amount of the monomer (c1) having a hydroxyl group and / or a carboxyl group and an ethylenically unsaturated double bond used for introducing a hydroxyl group or a carboxyl group is a single amount constituting the copolymer (C). It is preferable that it is 10 weight% or less in 100 weight% of a total of a body, and it is preferable that it is 0.01-8 weight%. When the monomer (c1) having a hydroxyl group and / or carboxyl group and an ethylenically unsaturated double bond is less than 0.01% by weight, the cohesive force as an adhesive layer is insufficient, and the temperature is high or high. The adhesive layer is liable to float, peel off, foam, crack or the like under moisture. On the other hand, if it exceeds 10% by weight, the degree of crosslinking becomes too high and the tackiness becomes poor.

In the present invention, the amount of the alkyl methacrylate (a) having no substituent, the amount of the monomer (c1) having a hydroxyl group and / or a carboxyl group and an ethylenically unsaturated double bond, and the copolymer (C) In consideration of Tg, a monomer having an alkyl acrylate (b) having no substituent, a substituent other than a hydroxyl group or a carboxyl group, and an ethylenically unsaturated double bond, which is used for forming the copolymer (C) ( The amount of the other monomer (c3) having an ethylenically unsaturated double bond that is not classified as c2) or any of the above monomers can be appropriately selected.
For example, the alkyl acrylate (b) having no substituent is preferably 45% by weight or more, and more preferably 50 to 78% by weight.

The copolymer (C) used in the present invention comprises two copolymer components having a high molecular weight and a low molecular weight with a molecular weight of 100,000 in GPC as a boundary. That is, the copolymer (C) is a copolymer component composed of polymer molecules having a molecular weight of 100,000 or more, and has a weight average molecular weight of 500,000 to 2,200,000, preferably 700,000 to 2,000,000, and Tg of -60. A high molecular weight copolymer (A) at ˜0 ° C .;
Low molecular weight copolymer (B) having a weight average molecular weight of 1,000 to 100,000, preferably 5,000 to 80,000 and Tg of -60 to 20 ° C. It consists of. If the weight average molecular weight of the high molecular weight copolymer is less than 500,000, the cohesive force of the adhesive layer will be insufficient even when reacted with the ethyleneimine curing agent (D) described later, resulting in floating / peeling, foaming, cracking, etc. Arise. On the other hand, the pressure-sensitive adhesive composition containing a high molecular weight copolymer having a weight average molecular weight of more than 2,200,000 has a high viscosity and poor workability such as coating and cannot maintain optical properties.
In addition, when a low molecular weight copolymer having a weight average molecular weight of less than 1000 is used, the cohesive force is insufficient, and floating / peeling, foaming, cracking and the like are likely to occur. Further, when a low molecular weight copolymer having a weight average molecular weight exceeding 100,000 is used, the stress concentration resulting from the expansion and contraction of the film cannot be sufficiently absorbed and relaxed, and a light leakage phenomenon occurs.

And it is important that the area ratio in GPC of a high molecular weight copolymer (A) and a low molecular weight copolymer (B) is (A) / (B) = 65 / 35-85 / 15, It is preferable that it is 70 / 30-80 / 20.
If the proportion of the low molecular weight copolymer (B) is too small, the stress concentration due to the expansion and contraction of the optical film cannot be sufficiently absorbed and relaxed, and a light leakage phenomenon occurs. On the other hand, if the proportion of the low molecular weight copolymer (B) is too large, the cohesive force of the pressure-sensitive adhesive layer is insufficient, and it tends to float, peel off, foam and crack.

Such a copolymer (C) can be obtained by various methods. For example, a high molecular weight copolymer (A) and a low molecular weight copolymer (B) can be obtained separately and mixed to obtain a high molecular weight copolymer (A). Then, the monomer is polymerized in the presence of the high molecular weight copolymer (A) to obtain a low molecular weight copolymer (B), and the copolymer (C) can be obtained as a composition containing both. it can.
The latter method is more preferable from the viewpoint of maintaining optical characteristics at high temperature or high temperature and high humidity.

Then, after obtaining a high molecular weight copolymer (A) which is a more preferable method, a monomer is polymerized in the presence of the high molecular weight copolymer (A) to obtain a low molecular weight copolymer (B). The method will be described in more detail.
For example, the high molecular weight copolymer (A) includes an alkyl methacrylate (a) having no substituent, an alkyl acrylate (b) having no substituent, and other ethylenic copolymers copolymerizable with (a) (b). A method such as bulk polymerization or solution polymerization, preferably using 0.001 to 1 part by weight of a polymerization initiator with respect to a total of 100 parts by weight of the monomer (c) having a saturated double bond, Is obtained by solution polymerization.
As the polymerization initiator, an azo compound or an organic peroxide is used, and two or more polymerization initiators may be used in combination.
In the case of solution polymerization, polymerization solvents include methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, xylene, hexane, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, n-propanol, isopropanol, etc. Is used. Two or more kinds of polymerization solvents may be mixed and used.

  Among the polymerization initiators, examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane 1- Carbonitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2′-azobis (2- Methyl propionate), 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2-hydroxymethylpropionitrile), 2,2′-azobis [2- (2-imidazoline) -2-yl) propane] and the like.

  Examples of organic peroxides include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, and di (2-ethoxyethyl) peroxy. Examples thereof include dicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxybivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, and diacetyl peroxide.

  First, the monomers (a) to (c) are polymerized until the conversion rate is 65 to 85% to obtain a high molecular weight copolymer (A) having a weight average molecular weight of 500,000 to 2,200,000. preferable. Here, the conversion rate is a value obtained by dividing the weight of the copolymer obtained by polymerizing the monomer by the total weight of the monomers used as raw materials. More specifically, a very small amount of the solution during polymerization is sampled and heated at 150 ° C. for about 20 minutes to obtain the solid content. The monomer volatilizes under the heating conditions, but the copolymer does not volatilize. Thus, by determining the solid content of the solution, the amount of the copolymer contained can be determined, and the conversion rate is calculated based on that.

  Next, the monomer remaining in the reaction system and a new monomer added as necessary are radically copolymerized until the conversion becomes 80 to 100%, and a low molecular weight copolymer ( By forming B), the copolymer (C) can be obtained. The monomer to be newly added is preferably a monomer (c) having another ethylenically unsaturated double bond that can be copolymerized with (a) and (b), and a hydroxyl group and / or a carboxyl group and ethylene. The monomer (c1) having a polymerizable unsaturated double bond is more preferred. The amount of the newly added monomer is 0.01 to 10% of the total amount of the monomers used for the polymerization of the high molecular weight copolymer (A) and the low molecular weight copolymer (B). %, And more preferably 0.05 to 8% by weight. A pressure-sensitive adhesive composition from the end when an optical film is cut by adding a monomer (c1) and positively introducing a hydroxyl group and / or a carboxyl group into the low molecular weight copolymer (B) Can be expected to prevent overhang.

When forming the low molecular weight copolymer (B), the polymerization is more than the polymerization initiator used for forming the high molecular weight copolymer (A), specifically about 5 to 50 times by weight. It is preferred to use an initiator. More specifically, it is preferable to use 0.005 to 50 parts by weight of a polymerization initiator with respect to 100 parts by weight of the total amount of monomers.
In synthesizing the low molecular weight copolymer (B), mercaptans such as n-lauryl mercaptan and n-dodecyl mercaptan, and chain transfer agents such as α-methylstyrene dimer and limonene may be used.
Thus, in GPC, a copolymer (A) / (B) = 65/35 to 85/15 (A) / (B) = area ratio of the low molecular weight copolymer (B) C) can be obtained.

The pressure-sensitive adhesive composition of the present invention contains the above-mentioned copolymer (C) having a hydroxyl group and / or a carboxyl group and an ethyleneimine curing agent (D). When the ethyleneimine-based curing agent (D) obtains an adhesive film, it reacts with the copolymer (C) having a hydroxyl group and / or a carboxyl group to form an adhesive layer. As an ethyleneimine type hardening | curing agent (D), what has 2 or more of ethyleneimino groups in 1 molecule is preferable, and what has 2-4 pieces is more preferable.
Ethyleneimine-based curing agents are extremely useful curing agents because they are excellent in curability, are not easily affected by temperature in aging performed after formation of the adhesive layer, and provide stable adhesive physical properties.

Examples of the ethyleneimine curing agent (D) include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxite), N, N′-toluene-2,4-bis (1-aziridine). Carboxite), bisisophthaloyl-1- (2-methylaziridine), tri-1-aziridinylphosphine oxide, N, N′-hexamethylene-1,6-bis (1-aziridinecarboxite), 2 , 2′-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate], trimethylolpropane tri-β-aziridinylpropionate, tetramethylolmethane tri-β-aziridinylpropionate, tris -2,4,6- (1-aziridinyl) -1,3,5-triazine and the like.
These ethyleneimine curing agents (D) are preferably used in an amount of 0.01 to 15 parts by weight with respect to 100 parts by weight of the copolymer (C). If it is less than 0.01 part by weight, the cohesive force of the adhesive layer tends to decrease, and if it exceeds 15 parts by weight, the adhesiveness to the adherend becomes poor. More preferably, it is 0.03-10 weight part.

  The curing agent used in the present invention may be a combination of an isocyanate curing agent, an epoxy curing agent, a metal chelate curing agent, and an amine curing agent in addition to the ethyleneimine curing agent (D).

  Examples of isocyanate curing agents include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, triphenylmethane. Polyisocyanate compounds such as triisocyanate and polymethylene polyphenyl isocyanate, adducts of these polyisocyanate compounds and polyol compounds such as trimethylolpropane, burettes and isocyanurates of these polyisocyanate compounds, and further these polyisocyanate compounds Known polyether polyols and polyesters Polyols, acrylic polyols, polybutadiene polyols, adducts, etc. and polyisoprene polyol and the like.

  Examples of the epoxy curing agent include bisphenol A-epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6- Hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidylaniline, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N′-diglycidylamino) Methyl) cyclohexane, N, N, N ′, N′-tetraglycidylaminophenylmethane, triglycidyl and the like.

  Examples of metal chelate curing agents include coordination compounds of polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium with acetylacetone and ethyl acetoacetate. Etc.

  Furthermore, examples of the amine curing agent include hexamethylenediamine, triethyldiamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethyltetramine, isophoronediamine, amino resin, and methylene resin.

The pressure-sensitive adhesive composition of the present invention preferably further contains a silane coupling agent.
As silane coupling agents, vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyl Dimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyl Methoxysilane N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-merca DOO triethoxysilane, mercaptopropyl butyl trimethoxysilane γ- mercaptopropyl methyl dimethoxy silane, and the like.
The silane coupling agent is effective in improving the adhesion between the pressure-sensitive adhesive layer and the glass, and is particularly effective for preventing the pressure-sensitive adhesive film from floating, peeling, foaming, cracking and the like under high temperature and high humidity.

The content of the silane coupling agent in the pressure-sensitive adhesive composition is preferably 0.01 to 2 parts by weight with respect to 100 parts by weight of the copolymer (C). If the amount is less than 0.01 parts by weight, the effect of improving the physical properties is poor. If the amount exceeds 2 parts by weight, the pressure-sensitive adhesive composition is not only expensive, but also causes floating, peeling, foaming, cracks, and the like.
Moreover, you may mix | blend a ultraviolet absorber, antioxidant, tackifying resin, a plasticizer, an antifoamer, a leveling regulator etc. in the adhesive composition in the range which does not inhibit the effect of this invention.

Next, the adhesive film of the present invention will be described.
In the pressure-sensitive adhesive film of the present invention, a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition of the present invention is formed on at least one surface of an optical film used for various display members. The pressure-sensitive adhesive film of the present invention is suitably used for forming various display members. For example, it is suitably affixed and used on the glass of a liquid crystal display member.

  Examples of the optical film used in the present invention include a polarizing film and a retardation film, and a polarizing film is preferable.

The pressure-sensitive adhesive sheet can be obtained by applying the pressure-sensitive adhesive composition of the present invention to the above optical film, drying to form a pressure-sensitive adhesive layer, laminating a release sheet, and aging as necessary.
Alternatively, the pressure-sensitive adhesive layer on the optical film is formed by applying the pressure-sensitive adhesive composition to a release sheet, drying to form a pressure-sensitive adhesive layer, bonding the optical film, and transferring the pressure-sensitive adhesive layer onto the optical film. It can also be based on the “transfer method”.
The pressure-sensitive adhesive layer can be formed using a commonly used coating apparatus. Examples of the coating apparatus include a roll knife coater, a die coater, a roll coater, a bar coater, a gravure roll coater, a reverse roll coater, dipping, and a blade coater.
The thickness of the adhesive layer is preferably 1 to 200 μm. If it is less than 1 μm, the tackiness is poor, and if it exceeds 200 μm, it is difficult to produce and handle an adhesive film.

Adhesive layer obtained as described above, a storage modulus at 120 ° C. is preferably a ^{0.1 × 10 5 Pa~5 × 10 5} Pa. More preferably ^{0.5 × 10 5 ~3 × 10 5} . The storage elastic modulus can be measured using a viscoelasticity tester “RDA-III” manufactured by TA Instruments Japan.

When the storage elastic modulus at 120 ° C. of the adhesive layer is smaller than 0.1 × 10 ⁵ Pa, the adhesive layer is bonded to an adherend such as glass and then exposed to high temperature or high temperature and humidity for a long time. Softens and is liable to float, peel, foam, crack and the like. On the other hand, when the storage elastic modulus at 120 ° C. of the adhesive layer is greater than 5 × 10 ⁵ Pa, the heat resistance is sufficiently high, but the adhesive layer is hard at room temperature, and therefore when the adhesive film is bonded to the adherend. The adhesive layer does not sufficiently adhere to the adherend, and the adhesive strength tends to decrease.

  EXAMPLES Next, although an Example of this invention is shown and it demonstrates further in detail, this invention is not limited by these. In the examples, “part” means “part by weight” and “%” means “% by weight”.

[Production Example 1]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 78 parts of n-butyl acrylate, 20 parts of methyl methacrylate, 1.5 parts of acrylic acid, 100 parts of acetone, AIBN (2, 2 '-Azobisisobutyronitrile (hereinafter referred to as “AIBN”) was charged in 0.03 part, the air in the reaction vessel was replaced with nitrogen gas, and the reaction solution was stirred under a nitrogen atmosphere with stirring. Was reacted for 4.5 hours at a reflux temperature until the conversion rate became 75% to obtain a mixed solution of a copolymer and a monomer having a weight average molecular weight of 1,030,000 and Tg of −32.1 ° C. Subsequently, 200 parts of toluene, 0.5 part of acrylic acid, and 0.2 part of AIBN were added, and the reaction was further continued for 6 hours until the conversion rate reached 100%, and the copolymer (C1) having a Tg of −31.7 ° C. A solution was obtained.
In GPC, the copolymer (C1) comprises a high molecular weight copolymer (A1) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B1) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A1) is 1,030,000, the weight average molecular weight of the low molecular weight copolymer (B1) is 30,000, and the area ratio of both is (A1) / (B1) = 75. / 25. The high molecular weight copolymer (A1) had a Tg of −32.1 ° C., and the low molecular weight copolymer (B1) had a Tg of −30.3 ° C.
In addition, said Tg was theoretically calculated by the following formula | equation (1) (FOX formula) based on the glass transition temperature of the homopolymer obtained from each monomer which comprises a copolymer. Value.
1 / Tg = [(W1 / Tg1) + (W2 / Tg2) + ... + (Wn / Tgn)] / 10 0 Formula (1)
(The temperature here is absolute.)
Wn:% by weight of monomer n
Tgn: Glass transition temperature of homopolymer composed of monomer n In particular, for Tg of high molecular weight copolymer (A1) and low molecular weight copolymer (B1), the weight parts of each monomer used and It is calculated based on the conversion rate.

[Production Example 2]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 73 parts of n-butyl acrylate, 25 parts of n-butyl methacrylate, 1.5 parts of acrylic acid, 100 parts of acetone, AIBN 0.03 After the air in the reaction vessel was replaced with nitrogen gas, the reaction solution was reacted for 4.5 hours at a reflux temperature at a reflux temperature until the conversion rate became 75% with stirring. A mixed solution of a copolymer and a monomer having a molecular weight of 980,000 and Tg of −37.6 ° C. was obtained.
Next, 200 parts of toluene, 0.5 part of acrylic acid, and 0.2 part of AIBN were added, and the reaction was further continued for 6 hours until the conversion reached 100%. The copolymer (C2) having a Tg of −37.1 ° C. A solution was obtained.
In GPC, the copolymer (C2) comprises a high molecular weight copolymer (A2) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B2) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A2) is 980,000, the weight average molecular weight of the low molecular weight copolymer (B2) is 31,000, and the area ratio of both is (A2) / (B2). = 75/25. The high molecular weight copolymer (A2) had a Tg of -37.6 ° C, and the low molecular weight copolymer (B2) had a Tg of -35.8 ° C.

[Production Example 3]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 78 parts of n-butyl acrylate, 20 parts of methyl methacrylate, 1.5 parts of acrylic acid, 100 parts of acetone, 0.03 part of AIBN After charging and replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted for 4 hours at a reflux temperature until the conversion rate reached 65% with stirring, under a nitrogen atmosphere, and the weight average molecular weight was 1,010,000. , A mixed solution of a copolymer and a monomer having a Tg of −32.1 ° C. was obtained.
Next, 200 parts of toluene, 0.5 part of 2HEMA, and 0.2 part of AIBN were added, and the mixture was further reacted for 6 hours until the conversion reached 100%. A solution of the copolymer (C3) having a Tg of −31.8 ° C. Obtained.
In GPC, the copolymer (C3) comprises a high molecular weight copolymer (A3) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B3) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A3) is 1.10,000, the weight average molecular weight of the low molecular weight copolymer (B3) is 28,000, and the area ratio of both is (A3) / (B3). = 65/35. The high molecular weight copolymer (A3) had a Tg of −32.1 ° C., and the low molecular weight copolymer (B3) had a Tg of −30.8 ° C.

[Production Example 4]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 83 parts of n-butyl acrylate, 15 parts of methyl methacrylate, 1.5 parts of acrylic acid, 100 parts of acetone, 0.03 part of AIBN After charging and replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted for 5 hours under a nitrogen atmosphere with stirring until the conversion rate reached 85% at the reflux temperature, and the weight average molecular weight was 1,000,000. , A mixed solution of a copolymer and a monomer having a Tg of −37.6 ° C. was obtained.
Next, 200 parts of toluene, 0.5 part of acrylic acid, and 0.2 part of AIBN were added, and the reaction was further continued for 6 hours until the conversion reached 100%, and the copolymer (C4) having a Tg of −37.1 ° C. A solution was obtained.
In GPC, the copolymer (C4) comprises a high molecular weight copolymer (A4) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B4) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A4) is 1,000,000, the weight average molecular weight of the low molecular weight copolymer (B4) is 37,000, and the area ratio of both is (A4) / (B4). = 85/15. The high molecular weight copolymer (A4) had a Tg of -37.6 ° C, and the low molecular weight copolymer (B4) had a Tg of -35.8 ° C.

[Production Example 5]
A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube was charged with 83 parts of n-butyl acrylate, 15 parts of methyl methacrylate, 1.5 parts of 2HEMA, 100 parts of acetone, 0.03 part of AIBN, After replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted under a nitrogen atmosphere with stirring for 4.5 hours at a reflux temperature until the conversion rate became 75%, and the weight average molecular weight was 1,000,000. , A mixed solution of a copolymer and a monomer having a Tg of −37.9 ° C. was obtained.
Next, 200 parts of toluene, 0.5 part of 2HEMA, and 0.2 part of AIBN were added, and the mixture was further reacted for 6 hours until the conversion reached 100%. A solution of the copolymer (C5) having a Tg of −37.6 ° C. Obtained.
In GPC, the copolymer (C5) comprises a high molecular weight copolymer (A5) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B5) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A5) is 1,000,000, the weight average molecular weight of the low molecular weight copolymer (B5) is 31,000, and the area ratio of both is (A5) / (B5). = 75/25. The high molecular weight copolymer (A5) had a Tg of -37.9 ° C, and the low molecular weight copolymer (B5) had a Tg of -36.6 ° C.

[Production Example 6]
A reactor equipped with a stirrer, thermometer, reflux condenser, dropping device, and nitrogen inlet tube was charged with 78 parts of n-butyl acrylate, 20 parts of methyl methacrylate, 2 parts of acrylic acid, 100 parts of acetone, and 0.03 part of AIBN. After replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted for 6 hours at a reflux temperature until the conversion rate reached 100% under stirring in a nitrogen atmosphere, and the weight average molecular weight was 1050,000. A solution of a high molecular weight copolymer (A6) having a Tg of −31.7 ° C. was obtained, diluted with toluene, and the nonvolatile content concentration was adjusted to 40%.

  Using the same apparatus, 78 parts of n-butyl acrylate, 20 parts of methyl methacrylate, 2 parts of acrylic acid, 150 parts of toluene and 0.03 part of AIBN were charged, and the air in the reaction vessel was replaced with nitrogen gas, followed by stirring. Under a nitrogen atmosphere, this reaction solution was reacted at reflux temperature for 6 hours until the conversion reached 100%, and the low molecular weight copolymer (B6) having a Tg of -31.7 ° C. and a weight average molecular weight of 30,000 was obtained. A solution was obtained (non-volatile content: 40%).

  Next, both copolymer solutions were mixed so that the weight ratio of the high molecular weight copolymer (A6) and the low molecular weight copolymer (B6) was (A6) / (B6) = 75/25, and Tg Obtained a copolymer (C6) solution at -31.7 ° C., and GPC was measured. The area ratio between the high molecular weight copolymer (A6) composed of polymer molecules having a molecular weight of 100,000 or more and the low molecular weight copolymer (B6) composed of polymer molecules having a molecular weight of less than 100,000, with a molecular weight of 100,000 as a boundary, It was (A6) / (B6) = 75/25.

[Production Example 7]
A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube was charged with 96 parts of n-butyl acrylate, 4 parts of acrylic acid, 75 parts of acetone, and 0.03 part of AIBN. After substituting air with nitrogen gas, this reaction solution was reacted for 4.5 hours at a reflux temperature under a nitrogen atmosphere with stirring until the conversion rate became 75%. The weight average molecular weight was 1,690,000 and Tg was −50. A mixed solution of copolymer and monomer at 2 ° C. was obtained. Next, 200 parts of toluene, 0.22 part of methacrylic acid, and 0.2 part of AIBN were added, and the mixture was further reacted for 6 hours until the conversion rate reached 100%, and the copolymer (C7) having a Tg of −50.0 ° C. A solution was obtained.
In GPC, the copolymer (C7) comprises a high molecular weight copolymer (A7) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B7) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A7) is 1,690,000, the weight average molecular weight of the low molecular weight copolymer (B7) is 34,000, and the area ratio of both is (A7) / (B7). = 75/25. The Tg of the high molecular weight copolymer (A7) was −50.2 ° C., and the Tg of the low molecular weight copolymer (B7) was −49.3 ° C.

[Production Example 8]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 58 parts of n-butyl acrylate, 40 parts of methyl methacrylate, 1.5 parts of acrylic acid, 100 parts of acetone, 0.03 part of AIBN Then, after replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted under a nitrogen atmosphere for 4.5 hours at a reflux temperature until the conversion rate became 75%, and the weight average molecular weight was changed. A mixed solution of a copolymer and a monomer having a million and Tg of −7.4 ° C. was obtained. Next, 200 parts of toluene, 0.5 part of acrylic acid, and 0.2 part of AIBN were added, and the mixture was further reacted for 6 hours until the conversion reached 100%. A solution of copolymer (C8) having a Tg of −7 ° C. Obtained.
In GPC, the copolymer (C8) comprises a high molecular weight copolymer (A8) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B8) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A8) is 1,000,000, the weight average molecular weight of the low molecular weight copolymer (B8) is 25,000, and the area ratio of both is (A8) / (B8). = 75/25. The high molecular weight copolymer (A8) had a Tg of −7.4 ° C., and the low molecular weight copolymer (B8) had a Tg of −5.8 ° C.

[Production Example 9]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 78 parts of n-butyl acrylate, 20 parts of methyl methacrylate, 1.5 parts of acrylic acid, 100 parts of acetone, 0.03 part of AIBN Then, after replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted for 3.5 hours at a reflux temperature under a nitrogen atmosphere until the conversion rate reached 62%, and the weight average molecular weight was A mixed solution of a copolymer and a monomer having 1.04 million and Tg of −32.1 ° C. was obtained. Subsequently, 200 parts of toluene, 0.5 part of acrylic acid, and 0.2 part of AIBN were added, and the reaction was further continued for 6 hours until the conversion rate reached 100%, and the copolymer (C9) having a Tg of −31.7 ° C. A solution was obtained.
In GPC, the copolymer (C9) comprises a high molecular weight copolymer (A9) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B9) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A9) is 1,040,000, the weight average molecular weight of the low molecular weight copolymer (B9) is 30,000, and the area ratio of both is (A9) / (B9) = 62. / 38. The Tg of the high molecular weight copolymer (A9) was −32.1 ° C., and the Tg of the low molecular weight copolymer (B9) was −31 ° C.

[Production Example 10]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 78 parts of n-butyl acrylate, 20 parts of methyl methacrylate, 1.5 parts of acrylic acid, 100 parts of acetone, 0.03 part of AIBN After charging and replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted for 5.5 hours at a reflux temperature until the conversion rate reached 90% under stirring in a nitrogen atmosphere. A mixed solution of a copolymer and a monomer having 1.1 million and Tg of −30.2 ° C. was obtained. Next, 200 parts of toluene, 0.5 part of acrylic acid, and 0.2 part of AIBN were added, and the reaction was further continued for 6 hours until the conversion rate reached 100%, and the copolymer (C10) having a Tg of −31.7 ° C. A solution was obtained.
In GPC, the copolymer (C10) comprises a high molecular weight copolymer (A10) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B10) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A10) is 1.1 million, the weight average molecular weight of the low molecular weight copolymer (B10) is 28,000, and the area ratio of both is (A10) / (B10). = 90/10. The high molecular weight copolymer (A10) had a Tg of −30.2 ° C., and the low molecular weight copolymer (B10) had a Tg of −27.9 ° C.

[Production Example 11]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 78 parts of n-butyl acrylate, 20 parts of methyl methacrylate, 1.5 parts of acrylic acid, 100 parts of acetone, 0.03 part of AIBN Then, after replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted under a nitrogen atmosphere for 4.5 hours at a reflux temperature until the conversion rate became 75%, and the weight average molecular weight was changed. A mixed solution of copolymer and monomer having a million and Tg of −32.1 ° C. was obtained. Next, 50 parts of acetone, 150 parts of toluene, 0.5 part of acrylic acid, and 0.2 part of AIBN are added, and the mixture is further reacted for 6 hours until the conversion becomes 100%. A copolymer having a Tg of −31.7 ° C. A solution of (C11) was obtained.
In GPC, the copolymer (C11) comprises a high molecular weight copolymer (A11) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B11) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A11) is 1,000,000, the weight average molecular weight of the low molecular weight copolymer (B11) is 120,000, and the area ratio of both is (A11) / (B11) = 75. / 25. The Tg of the high molecular weight copolymer (A11) was −32.1 ° C., and the Tg of the low molecular weight copolymer (B11) was −30.3 ° C.

[Production Example 12]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 68 parts of n-butyl acrylate, 5 parts of methyl methacrylate, 1.5 parts of acrylic acid, 100 parts of acetone, 0.03 part of AIBN Then, after replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted under a nitrogen atmosphere for 4.5 hours at a reflux temperature until the conversion rate became 75%, and the weight average molecular weight was changed. A mixed solution of a copolymer and a monomer having a ratio of 1.10,000 and Tg of −46.7 ° C. was obtained. Next, 200 parts of toluene, 0.5 part of acrylic acid, 25 parts of methyl methacrylate and 0.2 part of AIBN were added, and the reaction was further continued for 6 hours until the conversion reached 100%. A solution of coalescence (C12) was obtained.
In GPC, the copolymer (C12) comprises a high molecular weight copolymer (A12) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B12) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A12) is 1.10,000, the weight average molecular weight of the low molecular weight copolymer (B12) is 35,000, and the area ratio of both is (A12) / (B12). = 75/25. The high molecular weight copolymer (A12) had a Tg of −46.7 ° C., and the low molecular weight copolymer (B12) had a Tg of 22.4 ° C.

[Production Example 13]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introducing tube, 78 parts of n-butyl acrylate, 20 parts of methyl methacrylate, 1.5 parts of acrylic acid, 75 parts of toluene, 25 parts of acetone AIBN0. After charging 03 parts and replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted under a nitrogen atmosphere with stirring for 4.5 hours at a reflux temperature until the conversion rate became 75%. A mixed solution of a copolymer and a monomer having an average molecular weight of 450,000 and Tg of −32.1 ° C. was obtained. Next, 200 parts of toluene, 0.5 part of acrylic acid, and 0.2 part of AIBN were added, and the reaction was further continued for 6 hours until the conversion rate reached 100%, and the copolymer (C13) having a Tg of −31.7 ° C. A solution was obtained.
In GPC, the copolymer (C13) comprises a high molecular weight copolymer (A13) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B13) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A13) is 450,000, the weight average molecular weight of the low molecular weight copolymer (B13) is 30,000, and the area ratio of both is (A13) / (B13) = 75. / 25. The Tg of the high molecular weight copolymer (A13) was −32.1 ° C., and the Tg of the low molecular weight copolymer (B13) was −30.3 ° C.

[Production Example 14]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 78 parts of n-butyl acrylate, 20 parts of methyl methacrylate, 1.5 parts of acrylic acid, 50 parts of acetone, 0.03 part of AIBN Then, after replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted under a nitrogen atmosphere for 4.5 hours at a reflux temperature until the conversion rate became 75%, and the weight average molecular weight was changed. A mixed solution of a copolymer and a monomer having 2.5 million and Tg of −32.1 ° C. was obtained. Subsequently, 200 parts of toluene, 0.5 part of acrylic acid, and 0.2 part of AIBN were added, and the reaction was further continued for 6 hours until the conversion rate reached 100%, and the copolymer (C14) having a Tg of −31.7 ° C. A solution was obtained.
In GPC, the copolymer (C14) comprises a high molecular weight copolymer (A14) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B14) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A14) is 2.5 million, the weight average molecular weight of the low molecular weight copolymer (B14) is 30,000, and the area ratio of both is (A14) / (B14) = 75. / 25. The high molecular weight copolymer (A14) had a Tg of −32.1 ° C., and the low molecular weight copolymer (B14) had a Tg of −30.3 ° C.

[Production Example 15]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 73 parts of 2-ethylhexyl acrylate, 10 parts of methyl methacrylate, 1.5 parts of acrylic acid, 50 parts of acetone, 0.03 part of AIBN Then, after replacing the air in the reaction vessel with nitrogen gas, the reaction solution was reacted under a nitrogen atmosphere for 4.5 hours at a reflux temperature until the conversion rate became 75%, and the weight average molecular weight was changed. A mixed solution of copolymer and monomer having a million and Tg of −71.5 ° C. was obtained. Next, 200 parts of toluene, 0.5 part of acrylic acid, 15 parts of methyl methacrylate and 0.2 part of AIBN were added, and the reaction was further continued for 6 hours until the conversion reached 100%. A solution of coalescence (C15) was obtained.
In GPC, the copolymer (C15) comprises a high molecular weight copolymer (A15) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B15) composed of polymer molecules having a molecular weight of less than 100,000. And the weight average molecular weight of the high molecular weight copolymer (A15) is 1,000,000, the weight average molecular weight of the low molecular weight copolymer (B15) is 45,000, and the area ratio of both is (A15) / (B15). = 75/25. The Tg of the high molecular weight copolymer (A15) was −71.5 ° C., and the Tg of the low molecular weight copolymer (B15) was −22.2 ° C.

[Production Example 16]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 95 parts by weight of n-butyl acrylate, 5 parts by weight of acrylic acid, 100 parts by weight of ethyl acetate, and 0.2 part by weight of benzoyl peroxide Was placed in a reaction vessel, the air in the reaction solution vessel was replaced with nitrogen gas, and the reaction solution was reacted for 10 hours at a reflux temperature in a nitrogen atmosphere with stirring until the conversion rate reached 100%. Obtained a solution of a high molecular weight copolymer (A16) having a weight average molecular weight of 1.5 million and diluted with ethyl acetate to adjust the nonvolatile content concentration to 20%.

  Using the same apparatus, 65 parts by weight of n-butyl acrylate, 30 parts by weight of methyl methacrylate, 5 parts by weight of acrylamide, 100 parts by weight of toluene, 2 parts by weight of AIBN and 2 parts by weight of n-lauryl mercaptan were placed in a reaction vessel. After the air in the vessel was replaced with nitrogen gas, this reaction solution was reacted at a reflux temperature for 6 hours under a nitrogen atmosphere while stirring until the conversion rate reached 100%. Tg was −17.2 ° C., weight average A solution of a low molecular weight copolymer (B16) having a molecular weight of 10,000 was obtained, diluted with toluene, and adjusted to a nonvolatile content concentration of 40% by weight.

  Next, both copolymer solutions were mixed so that the weight ratio of the high molecular weight copolymer (A16) and the low molecular weight copolymer (B16) was (A16) / (B16) = 100/150, and Tg Gave a copolymer (C16) solution at -31.1 ° C. and GPC was measured. The area ratio between the high molecular weight copolymer (A16) composed of polymer molecules having a molecular weight of 100,000 or more and the low molecular weight copolymer (B16) composed of polymer molecules having a molecular weight of less than 100,000, with a molecular weight of 100,000 as a boundary, It was (A16) / (B16) = 40/60.

[Production Example 17]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 95 parts of n-butyl acrylate, 5 parts of acrylic acid, 0.3 part of benzoyl peroxide, 40 parts of ethyl acetate, 60 toluene. After the air in the reaction vessel was replaced with nitrogen gas, the reaction solution was allowed to undergo a polymerization reaction for 10 hours under a nitrogen atmosphere while stirring until the conversion rate reached 100% at the reflux temperature. A high molecular weight copolymer (A17) solution having a weight average molecular weight of 1000000 was obtained at −49.3 ° C., diluted with ethyl acetate, and adjusted to a nonvolatile content concentration of 20% by weight.

  Using the same apparatus, 99 parts of methyl methacrylate, 1 part of acrylic acid, 1 part of AIBN, 40 parts of ethyl acetate and 60 parts of toluene were placed in the reaction vessel, and the air in the reaction vessel was replaced with nitrogen gas, and then stirred. Under a nitrogen atmosphere, the reaction was continued for 6 hours at a reflux temperature until the conversion rate reached 100% to obtain a low molecular weight copolymer (B17) solution having a Tg of 105 ° C. and a weight average molecular weight of 20,000.

  Next, both copolymer solutions were mixed so that the weight ratio of the high molecular weight copolymer (A17) and the low molecular weight copolymer (B17) was (A17) / (B17) = 14/15, and Tg Obtained a copolymer (C17) solution at 10.5 ° C., and GPC was measured. The area ratio between the high molecular weight copolymer (A17) composed of polymer molecules having a molecular weight of 100,000 or more and the low molecular weight copolymer (B17) composed of polymer molecules having a molecular weight of less than 100,000, with a molecular weight of 100,000 as a boundary, It was (A17) / (B17) = 48/52.

[Production Example 18]
A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube was charged with 98 parts of n-butyl acrylate, 1 part of acrylic acid, 1 part of acrylamide, 100 parts of ethyl acetate, 0.03 part of AIBN, After the air in the reaction vessel was replaced with nitrogen gas, the reaction solution was reacted for 8 hours at a reflux temperature until the conversion rate reached 100% under stirring in a nitrogen atmosphere, and the Tg was −52.3 ° C., A high molecular weight copolymer (A18) solution having a weight average molecular weight of 700,000 was obtained and diluted with ethyl acetate to adjust the nonvolatile content concentration to 25%.

  Using the same apparatus, 86.4 parts of n-butyl acrylate, 13.6 parts of methyl methacrylate, 200 parts of ethyl acetate, and 0.03 part of AIBN were placed in a reaction vessel, and the air in the reaction vessel was replaced with nitrogen gas. In a nitrogen atmosphere with stirring, the mixture is reacted for 4 hours at a reflux temperature until the conversion becomes 100%, and a high molecular weight copolymer (A18 ′) solution having a Tg of −40.7 ° C. and a weight average molecular weight of 300,000. Was diluted with ethyl acetate, and the nonvolatile content concentration was adjusted to 25%.

  Next, both copolymer solutions were mixed so that the weight ratio of the high molecular weight copolymers (A18) and (A18 ′) was (A18) / (A18 ′) = 100/30, and the Tg was −49. A copolymer (C18) solution at 0.7 ° C. was obtained, and GPC was measured.

[Production Example 19]
A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube was charged with 95 parts of n-butyl acrylate, 5 parts of acrylic acid, 100 parts of ethyl acetate, and 0.2 parts of AIBN. After the air was replaced with nitrogen gas, the reaction solution was allowed to react for 12 hours at a reflux temperature until the conversion rate reached 100% in a nitrogen atmosphere with stirring. The Tg was -49.3 ° C. and the weight average molecular weight was A 1.5 million high molecular weight copolymer (A19) solution was obtained, diluted with ethyl acetate, and the nonvolatile content concentration was adjusted to 20%.

  Using the same apparatus, after putting 100 parts of n-butyl acrylate, 100 parts of toluene, 5 parts of α-methylstyrene dimer as chain transfer agent, and 2 parts of AIBN into the reaction vessel, the air in the reaction vessel was replaced with nitrogen gas. The reaction solution was reacted for 6 hours under a nitrogen atmosphere with stirring until the conversion rate reached 100% at a reflux temperature, and a low molecular weight copolymer (B19) solution having a Tg of −54 ° C. and a weight average molecular weight of 7,000. And diluted with toluene to adjust the nonvolatile content concentration to 40%.

  Next, both copolymer solutions were mixed so that the weight ratio of the high molecular weight copolymer (A19) and the low molecular weight copolymer (B19) was (A19) / (B19) = 100/100, and Tg Obtained a copolymer (C19) solution at -51.7 ° C., and GPC was measured. The area ratio between the high molecular weight copolymer (A19) composed of polymer molecules having a molecular weight of 100,000 or more and the low molecular weight copolymer (B19) composed of polymer molecules having a molecular weight of less than 100,000, with a molecular weight of 100,000 as a boundary, It was (A19) / (B19) = 50/50.

Abbreviations of monomers in Tables 1 to 3 are shown below.
BA: butyl acrylate MMA: methyl methacrylate BMA: butyl methacrylate AA: acrylic acid 2HEMA: 2-hydroxyethyl methacrylate MAA: methacrylic acid AAm: acrylamide

In addition, the weight average molecular weight of a copolymer is the weight average molecular weight of polystyrene conversion calculated | required by GPC measurement, and GPC measurement conditions are as follows.
Apparatus: Shodex GPC System-21 [manufactured by Showa Denko KK]
Column: A total of three Shodex KF-602.5 and two Shodex KF-606M (manufactured by Showa Denko KK) are connected and used.
Solvent: Tetrahydrofuran Flow rate: 0.5 ml / min
Temperature: 40 ° C
Sample concentration: 0.1 wt%
Sample injection volume: 50 μl

[Example 1]
Ethyleneimine-based curing agent 1 (2,2′-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate]) was added to 100 parts of the solid content of the copolymer (C1) solution obtained in Production Example 1. Was added as an active ingredient, and 0.1 part of silane coupling agent 1 (3-glycidoxypropyltrimethoxysilane) was added as an active ingredient and stirred well to obtain an adhesive composition. The obtained adhesive composition was subjected to various tests described later.

[Example 2] to [Example 6]
Instead of the copolymer (C1) solution, the adhesive composition was prepared in the same manner as in Example 1 except that each of the copolymer (C2) to (C6) solutions obtained in Production Examples 2 to 6 was used. Obtained and evaluated in the same manner as in Example 1.

[Comparative Example 1]
Epoxy curing agent 1 (N, N, N ′, N′-tetraglycidyl-m-xylenediamine) was added as an active ingredient to 100 parts of the solid content of the copolymer (C7) solution obtained in Production Example 7. .25 parts, 1 part of silane coupling agent 2 (3-aminopropyltrimethoxysilane) as an active ingredient was added and stirred well to obtain an adhesive composition. When evaluated in the same manner as in Example 1, cracks occurred in the heat resistance test and the moist heat resistance test.

[Comparative Example 2] to [Comparative Example 9]
Instead of the copolymer (C1) solution, the adhesive composition was prepared in the same manner as in Example 1 except that each of the copolymer (C8) to (C15) solutions obtained in Production Examples 8 to 15 was used. Obtained and evaluated in the same manner as in Example 1.

[Comparative Example 10]
Epoxy curing agent 1 (N, N, N ′, N′-tetraglycidyl-m-xylenediamine) as an active ingredient is added to 250 parts by weight of the solid content of the copolymer (C16) solution obtained in Production Example 16. 0.02 part was added, it stirred well, the adhesion composition was obtained, and when it evaluated similarly to Example 1, the rework property was bad, and the crack was seen by the heat resistance test and the heat-and-moisture resistance test.

[Comparative Example 11]
To 100 parts by weight of the solid content of the copolymer (C17) solution obtained in Production Example 17, 0.05 part of epoxy-based curing agent 2 (ethylene glycol diglycidyl ether) is added as an active ingredient, and stirred well. When an adhesive composition was obtained and evaluated in the same manner as in Example 1, a light leakage phenomenon occurred, and cracks were observed in a heat resistance test and a moist heat resistance test.

[Comparative Example 12]
Epoxy curing agent 1 (N, N, N ′, N′-tetraglycidyl-m-xylenediamine) as an active ingredient is added to 130 parts by weight of the solid content of the copolymer (C18) solution obtained in Production Example 18. 0.6 part was added, it stirred well, the adhesion composition was obtained, and it evaluated similarly to Example 1. FIG. As a result of evaluation, reworkability was extremely inferior, and cracks were observed in the heat resistance test and the heat and humidity resistance test.

[Comparative Example 13]
To 200 parts by weight of the solid content of the copolymer (C19) solution obtained in Production Example 19, ethyleneimine-based curing agent 2 (trimethylolpropane tri-β-aziridinylpropionate) was added as an active ingredient. .25 parts by weight, 2.5 parts by weight of an active ingredient of a phenolic compound (3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester) as an antioxidant, and silane coupling agent 3 1 part by weight of (3-aminopropyltrimethoxysilane) as an active ingredient was added and stirred well to obtain an adhesive composition, which was evaluated in the same manner as in Example 1. As a result of the evaluation, cracks were observed in the heat resistance test and the moist heat resistance test.

[Comparative Example 14]
A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except that an isocyanate-based curing agent (trimethylolpropane adduct of xylylene diisocyanate) was used instead of the ethyleneimine-based curing agent 1. Example 1 And evaluated in the same manner.

[Various tests]
<Adhesive strength and reworkability>
The adhesive composition obtained in each Example and each Comparative Example was applied to a polyester release film (thickness 38 μm) and dried at 100 ° C. for 2 minutes to form an adhesive layer having a thickness of 25 μm. A polarizing film (thickness: 180 μm) was placed on the adhesive layer and allowed to stand in an atmosphere of 23 ° C.-50% RH for 7 days to allow the reaction to proceed (aging), whereby an adhesive film 1 was obtained.
Each obtained adhesive film 1 is cut into a width of 25 mm, the release film is peeled off, and the exposed adhesive layer is attached to a glass plate having a thickness of 0.7 mm at 23 ° C.-50% RH, in accordance with JIS Z 0237. And roll-bonded.
After 24 hours, the peel strength (180 degree peel, tensile speed 300 mm / min; unit mN / 25 mm width) was measured with a peel tester. And whether the adhesive composition remained on the surface of the glass after peeling an adhesive film from a glass plate was observed visually.
The evaluation criteria are as follows.
○: No adhesive composition remaining, peel strength of 5 N / 25 mm or less Δ: No adhesive composition remaining, peel strength of 5 N / 25 mm or more x: Adhesive composition remaining, peel strength of 5 N / 25 mm or more

<Light leakage phenomenon>
The adhesive composition obtained in each Example and each Comparative Example was applied to a polyester release film (thickness 38 μm) and dried at 90 ° C. for 60 seconds to form an adhesive layer having a thickness of 25 μm. A polarizing film (thickness: 180 μm) was placed on the adhesive layer and allowed to stand in an atmosphere of 23 ° C.-50% RH for 7 days to allow the reaction to proceed (aging) to obtain an adhesive film 2.
The pressure-sensitive adhesive film 2 was cut into 80 mm × 150 mm so that the axial direction of the absorption axis of each pressure-sensitive adhesive film 2 was at an angle of 45 ° with respect to the long side.
The release film of the adhesive film 3 is peeled off, and the exposed adhesive layer is placed on both surfaces of a 0.4 mm thick glass plate so that the axial directions of the respective absorption axes are orthogonal to each other, and 5 kg / cm in a 50 ° C. atmosphere. ^After applying the pressure of ² and holding for 15 minutes for bonding, the substrate was left in an atmosphere at 80 ° C. for 500 hours and then returned to room temperature, and the presence or absence of light leakage from the four corners or peripheral edges was observed.
The evaluation criteria are as follows.
○: No light leakage is observed.
Δ: Light leakage is slightly noticeable.
X: Light leakage is very remarkable.

<Heat resistance and moist heat resistance>
The release film of the adhesive film 3 described in the light leakage phenomenon is peeled off, and the exposed adhesive layer is subjected to a pressure of 5 Kg / cm ² in a 50 ° C. atmosphere on one side of a 0.4 mm thick glass plate for 15 minutes. After holding and bonding, the substrate was left in an atmosphere at 80 ° C. for 500 hours (heat resistance test). Similarly, after the adhesive film 3 and glass were bonded together, they were left in a constant temperature and humidity chamber at 60 ° C.-90% RH for 500 hours (moisture and heat resistance test).
After standing, the temperature was returned to room temperature, and the occurrence of the floating / peeling, foaming and cracking of the adhesive film 3 was observed.
Foaming is a state in which relatively large bubbles are generated at the interface between the adhesive layer and the glass (other than the peripheral edge).
The floating / peeling is a state where the adhesive film 3 is lifted from the glass and peeled off.
The crack is a state in which fine bubbles having a diameter of 1 mm or less are generated at the peripheral edge of the adhesive film 3 so as to be continuous in a streak shape.
Each evaluation standard is as follows.
○: Not generated.
Δ: Minor occurrence is observed.
X: Remarkable occurrence is observed.

<Displacement>
In the same manner as the light leakage phenomenon, the obtained adhesive film 3 is arranged on both surfaces of the glass plate so that the axial directions of the respective absorption axes are orthogonal, and a pressure of 5 kg / cm ² is applied in a 50 ° C. atmosphere. After holding for 15 minutes and bonding, the sample was left in an atmosphere of 80 ° C. for 500 hours and then returned to room temperature, and the contracted state of the adhesive film 3 before and after being left was observed as a deviation. That is, the deviation is a distance (mm) of movement of the film peripheral edge contracted after the test from the position of the film peripheral edge bonded before the test.

  The above evaluation results are shown in Tables 4-6.

Abbreviations in Tables 4 to 6 are as follows.
Ethyleneimine curing agent 1: 2,2′-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate]
Ethyleneimine curing agent 2: Trimethylolpropane tri-β-aziridinylpropionate epoxy curing agent 1: N, N, N ′, N′-tetraglycidyl-m-xylenediamine epoxy curing agent 2: ethylene Glycol diglycidyl ether isocyanate curing agent: xylylene diisocyanate trimethylolpropane adduct antioxidant: 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester silane coupling agent 1: 3 -Glycidoxypropyltrimethoxysilane silane coupling agent 2: 3-aminopropyltrimethoxysilane silane coupling agent 3: 3-aminopropyltrimethoxysilane

Claims (7)

A pressure-sensitive adhesive composition containing the following copolymer (C) having a hydroxyl group and / or a carboxyl group and having a glass transition temperature of −60 to 0 ° C. and an ethyleneimine curing agent (D),
The copolymer (C) is
Alkyl methacrylate having no substituent (a): 15 to 35% by weight, alkyl acrylate (b) having no substituent and other ethylenically unsaturated double bonds copolymerizable with the above (a) and (b) A monomer comprising the monomer (c) having a radical copolymerization (provided that the total of (a) to (c) is 100% by weight);
A high molecular weight copolymer (A) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B) composed of polymer molecules having a molecular weight of less than 100,000,
In gel permeation chromatography, the area ratio of the high molecular weight copolymer (A) to the low molecular weight copolymer (B) is (A) / (B) = 65/35 to 85/15. ,
The weight average molecular weight of the high molecular weight copolymer (A) is 500,000 to 2,200,000, the glass transition temperature is −60 to 0 ° C., the weight average molecular weight of the low molecular weight copolymer (B) is 1,000 to 100,000, and the glass transition temperature. Is a pressure-sensitive adhesive composition, which is -60 to 20 ° C. The alkyl group of the alkyl methacrylate (a) having no substituent has 1 to 6 carbon atoms, and the alkyl group is selected from the group consisting of a linear alkyl group, a chain alkyl group having a branched structure, and a cyclic alkyl group. The pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive composition is at least one. The pressure-sensitive adhesive composition according to claim 1 or 2, comprising 0.01 to 10 parts by weight of the ethyleneimine curing agent (D) with respect to 100 parts by weight of the copolymer (C). A pressure-sensitive adhesive composition containing the following copolymer (C) having a hydroxyl group and / or a carboxyl group and having a glass transition temperature of −60 to 0 ° C. and an ethyleneimine curing agent (D),
The copolymer (C) is
Alkyl methacrylate having no substituent (a): 15 to 35% by weight, alkyl acrylate (b) having no substituent and other ethylenically unsaturated double bonds copolymerizable with the above (a) and (b) The monomer comprising the monomer (c) is radically copolymerized until the polymerization conversion is 65 to 85% to obtain a copolymer having a weight average molecular weight of 500,000 to 2,200,000, and then the above (a ) (B) and another monomer (c) having an ethylenically unsaturated double bond copolymerizable with (b), and further radically copolymerized until the polymerization conversion becomes 80 to 100% [however, The total of (a) to (c) is 100% by weight],
A high molecular weight copolymer (A) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B) composed of polymer molecules having a molecular weight of less than 100,000,
In gel permeation chromatography, the area ratio of the high molecular weight copolymer (A) to the low molecular weight copolymer (B) is (A) / (B) = 65/35 to 85/15. ,
The weight average molecular weight of the high molecular weight copolymer (A) is 500,000 to 2,200,000, the glass transition temperature is −60 to 0 ° C., the weight average molecular weight of the low molecular weight copolymer (B) is 1,000 to 100,000, and the glass transition temperature. Is a pressure-sensitive adhesive composition, which is -60 to 20 ° C. Alkyl methacrylate having no substituent (a): 15 to 35% by weight, alkyl acrylate (b) having no substituent and other ethylenically unsaturated double bonds copolymerizable with the above (a) and (b) The monomer comprising the monomer (c) is radically copolymerized until the polymerization conversion is 65 to 85% to obtain a copolymer having a weight average molecular weight of 500,000 to 2,200,000, and then the above (a ) Add another monomer (c) having an ethylenically unsaturated double bond copolymerizable with (b), and further carry out radical copolymerization until the polymerization conversion becomes 80 to 100% [However, (a ) To (c) is 100% by weight]
Including a high molecular weight copolymer (A) composed of polymer molecules having a molecular weight of 100,000 or more and a low molecular weight copolymer (B) composed of polymer molecules having a molecular weight of less than 100,000, and having a hydroxyl group and / or a carboxyl group, A copolymer (C) having a glass transition temperature of −60 to 0 ° C.,
In gel permeation chromatography, the area ratio of the high molecular weight copolymer (A) to the low molecular weight copolymer (B) is (A) / (B) = 65/35 to 85/15. ,
The weight average molecular weight of the high molecular weight copolymer (A) is 500,000 to 2,200,000, the glass transition temperature is −60 to 0 ° C., the weight average molecular weight of the low molecular weight copolymer (B) is 1,000 to 100,000, and the glass transition temperature. To obtain a copolymer (C) having a temperature of -60 to 20 ° C,
Then, the ethyleneimine type hardening | curing agent (D) is added to this copolymer (C), The manufacturing method of the adhesive composition characterized by the above-mentioned. A pressure-sensitive adhesive composition obtained by the production method according to claim 5. The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to claim 1 or 4 is provided on at least one surface of an optical film selected from the group consisting of a polarizing film and a retardation film. Adhesive film.