TW202244224A - Adhesive composition for flexible displays, adhesive material, and adhesive sheet - Google Patents

Abstract

To provide an adhesive composition which has adhesive force suitable for an adhesive material (adhesive layer), and from which can be formed an adhesive material (adhesive layer) having excellent flexibility and excellent resilience. An adhesive composition for flexible displays comprising a plurality of (meth)acrylic copolymer components and a crosslinking agent, and being characterized in that: the (meth)acrylic copolymer components include at least a (meth)acrylic copolymerization component (A) and a (meth)acrylic copolymer component (B); the (meth)acrylic copolymerization component (A) has a first reactive group and has a molecular weight distribution (Mw/Mn) of not more than 3.0; the (meth)acrylic copolymer component (B) has a first reactive group and a molecular weight distribution (Mw/Mn) of greater than 3.0; the crosslinking agent has a second reactive group which reacts with the first reactive group; and the content ratio of the (meth)acrylic copolymerization component (A) in the plurality of (meth)acrylic copolymer components is 75-99 mass%.

Description

Adhesive composition, adhesive material and adhesive sheet for flexible display

The present invention relates to an adhesive composition for a flexible display, in particular to an adhesive composition for forming an adhesive material, the adhesive material is used to attach a flexible component to other flexible components.

Adhesives are generally used to join components that make up various displays or touch screens such as TVs, mobile phones, and smart phones. Adhesive materials used to attach components to each other include, for example, a substrate-attached adhesive sheet with an adhesive layer on a supporting substrate, or a substrate-less adhesive sheet without a supporting substrate, and the like.

On the other hand, what has attracted attention in recent years is a flexible display that can be repeatedly bent and used on image display devices such as liquid crystal display devices or organic light-emitting diode (organic EL) display devices. Among the flexible displays, there are foldable foldable displays, roll-type displays that can be rolled into a tube, etc., which are used in mobile terminals such as smart phones and tablet computer terminals, or fixed displays that can be stored, etc. Applications on devices are particularly exciting.

In such a flexible display, the adhesive material used to attach the flexible member constituting the member that can be repeatedly folded and extended to other flexible members is, for example, the repeated folding method disclosed in Patent Document 1. Adhesive material for curved devices, when the adhesive layer is displaced 1000% in opposite directions on one side and the other side of the adhesive layer, relative to the maximum shear stress at that time point, the ratio of the shear stress after 1000% displacement for 60 seconds to the setting The glue fraction is controlled within a specific range (refer to Patent Document 1 (claim item 1)).

[Prior Art Literature] [Patent Document] [Patent Document 1] Japanese Patent Laid-Open No. 2019-108498

[Problem to be solved by the present invention] In the past, when a flexible display with an adhesive layer was repeatedly bent, the adhesive layer could not completely return from the bent state to its original state, so after repeated bending of the flexible display, the bend occurred. The interface between the adhesive layer and the flexible member has floating or peeling, or the appearance of wrinkles at the bending place.

In view of the foregoing circumstances, the object of the present invention is to provide an adhesive composition capable of forming an adhesive material (adhesive layer) having suitable adhesive force, excellent flexibility, and excellent recovery for an adhesive material (adhesive layer).

[Technical means to solve the problem] In order to solve the aforementioned problems, the adhesive composition for flexible displays of the present invention is used to bond a flexible member constituting a flexible display with other flexible members, and the adhesive composition includes a plurality of (a base) an acrylic copolymer component and a crosslinking agent, the (meth)acrylic copolymer component at least includes (A) a (meth)acrylic copolymer component and (B) a (meth)acrylic copolymer component, Wherein the (A) (meth)acrylic copolymer component has a first reactive group, the molecular weight distribution (Mw/Mn) is 3.0 or less, and the (B) (meth)acrylic polymer component has a first reactive group , the molecular weight distribution (Mw/Mn) is greater than 3.0, the crosslinking agent has a second reactive group that reacts with the aforementioned first reactive group, and in the plurality of (meth)acrylic copolymer components, the (A) The content of the (meth)acrylic copolymer component is 75% by mass to 99% by mass.

[Efficacy of Invention] The effect of the present invention is that, using the adhesive composition for flexible displays, an adhesive material (adhesive layer) having an adhesive force suitable for an adhesive material (adhesive layer) and having excellent flexibility and recovery can be formed. Therefore, by using the adhesive composition for flexible displays of the present invention, even if it is repeatedly bent, the interface between the adhesive layer at the bent point and the flexible member will not float or peel off, and it can also A flexible display that suppresses appearance defects such as cracks and wrinkles.

Hereinafter, an example of a preferred embodiment of the present invention will be described. However, the embodiments described below are only examples, and the present invention is by no means limited by the embodiments described below.

In the present invention, "(meth)acrylic acid" means "at least one of acrylic acid and methacrylic acid", "(meth)acrylate" means "at least one of acrylate and methacrylate", "(Meth)acryl" means "at least one of acryl and methacryl", and "vinyl monomer" means a carbon-carbon double bond capable of free-radical polymerization in the molecule The monomer of the monomer, "the structural unit derived from the vinyl monomer" refers to the carbon-carbon double bond that can undergo free radical polymerization in the vinyl monomer and becomes the structural unit of the carbon-carbon single bond after polymerization, "derived from (methyl ) acrylate structural unit” refers to the structural unit in which the carbon-carbon double bond that can undergo free radical polymerization in (meth)acrylate becomes a carbon-carbon single bond after polymerization, and “from (meth)acrylic acid monomer "Structural unit" refers to a structural unit in which a carbon-carbon double bond that can undergo radical polymerization in a (meth)acrylic monomer becomes a carbon-carbon single bond after polymerization.

[Adhesive composition for flexible displays] In the present invention, the adhesive composition for flexible displays (hereinafter referred to as "adhesive composition") refers to an adhesive composition used to bond one flexible member constituting a flexible display with other flexible members. Adhesive composition for flexible display. The aforementioned adhesive composition includes a plurality of (meth)acrylic copolymer components and a crosslinking agent.

((Meth)acrylic copolymer component) The (meth)acrylic copolymer component of the aforementioned adhesive composition contains at least (A) (meth)acrylic copolymer component (hereinafter referred to as “(A) polymer material component”) and (B) (meth)acrylic copolymer component (hereinafter or simply referred to as “(B) polymer component”). The aforementioned mixture containing multiple (meth)acrylic copolymer components, or simply referred to as (meth)acrylic copolymer mixture. The (A) (meth)acrylic copolymer component has a first reactive group, the molecular weight distribution (Mw/Mn) is 3.0 or less, and the (B) (meth)acrylic copolymer component has a first reactive group , Molecular weight distribution (Mw/Mn) greater than 3.0. In addition, the content rate of (A) (meth)acrylic copolymer component in the above-mentioned plural (meth)acrylic copolymer components is 75% by mass to 99% by mass, and a specific content of (A) (meth)acrylic copolymer component is contained. ) The adhesive formed by the acrylic copolymer component and (B) the (meth)acrylic copolymer component is not only soft and has excellent recovery properties, but also possesses an adhesive force suitable for use as an adhesive.

((A) (meth)acrylic copolymer component) The aforementioned (A) (meth)acrylic copolymer component may be a structural unit derived from a (meth)acrylic monomer as the main component (50% by mass or more) The (A) polymer component may be one type, or two or more types. In addition, the (A) polymer component may contain structural units derived from vinyl monomers other than (meth)acrylic monomers . The (A) polymer component has a content rate of a structural unit derived from a (meth)acrylic monomer, based on 100% by mass of the polymer component, preferably at least 80% by mass, more preferably at least 90% by mass. In addition, this (A) polymer component may consist only of the structural unit derived from a (meth)acryl monomer.

The aforementioned (A) polymer component is preferably a (meth)acrylate copolymer. (Meth)acrylate-based copolymers may be copolymers whose main component (50% by mass or more) is a structural unit derived from (meth)acrylate, and may contain units derived from vinyl monomers other than (meth)acrylate the structural unit. The (meth)acrylate is an ester compound in which the hydrogen atom of the carboxyl group in (meth)acrylic acid is replaced by an organic group. The (A) polymer component has a content rate of a structural unit derived from (meth)acrylate, based on 100% by mass of the polymer component, preferably at least 80% by mass, more preferably at least 90% by mass.

The aforementioned (A) polymer component has a first reactive group, and the first reactive group is a functional group having high reactivity with a second reactive group of a crosslinking agent described later. The functional groups that can be used as the first reactive group include reactive functional groups, such as hydroxyl, carboxyl, epoxy, etc., among which hydroxyl and/or carboxyl are preferred, and hydroxyl or carboxyl are more preferred.

The amount of the first reactive group of the aforementioned (A) polymer component is preferably not less than 0.002 mmol/g, more preferably not less than 0.006 mmol/g, more preferably not less than 0.01 mmol/g; preferably not more than 0.8 mmol/g , more preferably 0.6 mmol/g or less, more preferably 0.5 mmol/g or less, particularly preferably 0.2 mmol/g or less, most preferably 0.1 mmol/g or less. When the amount of the first reactive group is more than 0.002 mmol/g, the formed adhesive material is properly cross-linked and exhibits an ideal recovery rate; when it is less than 0.8 mmol/g, the formed adhesive material has Sufficient distance, excellent flexibility.

The aforementioned (A) polymer component preferably has a hydroxyl group as the first reactive group, and also contains a carboxyl group as a functional group other than the first reactive group. At this time, the carboxyl group content of the aforementioned (A) copolymer is preferably at least 0.08 mmol/g, more preferably at least 0.16 mmol/g, more preferably at least 0.32 mmol/g; preferably at most 1.3 mmol/g, and even more preferably It is 0.8 mmol/g or less, more preferably 0.6 mmol/g or less.

When the aforementioned (A) polymer component uses hydroxyl as the first reactive group and contains both carboxyl and hydroxyl groups, the molar ratio (carboxyl/hydroxyl) of the carboxyl and hydroxyl per unit mass of the (A) polymer component is preferably 4 or more, more preferably 8 or more, more preferably 16 or more; preferably less than 60, more preferably less than 40, more preferably less than 30. When the molar ratio (carboxyl group/hydroxyl group) is within the above range, the adhesive layer has high recovery and achieves an ideal balance of adhesive force and softness.

The aforementioned (A) polymer component preferably has a carboxyl group as the first reactive group, and also contains a hydroxyl group as a functional group other than the first reactive group. At this time, the amount of hydroxyl groups in the polymer component (A) is preferably at least 0.01 mmol/g, more preferably at least 0.02 mmol/g, more preferably at least 0.04 mmol/g, preferably at most 0.25 mmol/g, and more preferably at least 0.02 mmol/g. It is preferably at most 0.20 mmol/g, more preferably at most 0.15 mmol/g.

When the aforementioned (A) polymer component has a carboxyl group as the first reactive group and contains both a carboxyl group and a hydroxyl group, the molar ratio (carboxyl group/hydroxyl group) of the carboxyl group and hydroxyl group per unit mass of the (A) polymer component is preferably Above 3.0, more preferably above 3.5, more preferably above 4.0; preferably below 30, more preferably below 25, more preferably below 20. When the molar ratio (carboxyl group/hydroxyl group) is within the above range, the adhesive layer has high recovery and achieves an ideal balance of adhesive force and softness.

The aforementioned (A) polymer component can be any of random copolymer, block copolymer or graft copolymer, preferably random copolymer.

The weight average molecular weight (Mw) of the aforementioned (A) polymer component is preferably more than 100,000, more preferably more than 200,000, more preferably more than 600,000, and most preferably more than 800,000; preferably less than 3 million, and more preferably Preferably it is less than 2.5 million, more preferably less than 2.3 million. When the Mw of the (A) polymer component is 100,000 or more, the cohesive force increases, and the heat resistance of the formed adhesive material improves; and when it is 3 million or less, the coating workability of the adhesive composition becomes better. The method of measuring the weight average molecular weight (Mw) will be described later.

The molecular weight distribution (Mw/Mn) of the aforementioned (A) polymer component is 3.0 or less, preferably 2.5 or less, more preferably 2.2 or less, more preferably 1.8 or less. The smaller the Mw/Mn, the narrower the molecular weight distribution, and the more uniform the molecular weight of the copolymer. When the value is 1.0, the molecular weight distribution is the narrowest. When Mw/Mn is 3.0 or less, compared with the molecular weight of the designed copolymer, the content of polymers with small molecular weight and high molecular weight is low, and the adhesive material has excellent bending resistance. The molecular weight distribution (Mw/Mn) in the present invention is a value calculated as (weight average molecular weight (Mw))/(number average molecular weight (Mn)). The measurement methods of Mw and Mn will be described later.

The glass transition temperature (Tg) of the aforementioned (A) polymer component is preferably above -70°, more preferably above -60°C; preferably below 0°C, more preferably below -10°C, more preferably below -20°C. When the Tg is above -70°C, the adhesive material will obtain sufficient cohesion, and the durability of the adhesive material formed will be improved, and when the Tg is below 0°C, the adhesion between the adhesive material formed and the adherend will be improved, Suppresses peeling at low temperatures and improves durability.

The Tg of the aforementioned polymer component is a value calculated by the following FOX formula (mathematical formula (1)). In the mathematical formula (1), Tg represents the glass transition temperature (°C) of the copolymer, Tgi represents the glass transition temperature (°C) when the vinyl monomer i forms a homopolymer, and Wi represents all the vinyl monomers forming the copolymer The mass ratio of vinyl monomer i in , ΣWi = 1, i is a natural number from 1 to n.

[number 1]

The aforementioned (A) polymer component contains a polymer component ((A1) polymer component) with a weight average molecular weight of 1 million or more and a polymer component ((A2) polymer component) with a weight average molecular weight of less than 1 million. Preferably, containing the polymer component (A1) and the polymer component (A2) can make the formed adhesive more flexible.

The weight average molecular weight (Mw) of the aforementioned (A1) polymer component is preferably more than 1 million, more preferably more than 1.3 million, more preferably more than 1.5 million; preferably less than 3 million, more preferably less than 2.5 million, and more preferably The best is below 2.3 million. The molecular weight distribution (Mw/Mn) of the polymer component (A1) is 3.0 or less, preferably 2.5 or less, more preferably 2.2 or less, more preferably 1.8 or less.

The weight average molecular weight (Mw) of the aforementioned (A2) polymer component is preferably more than 100,000, more preferably more than 200,000, more preferably more than 600,000, and especially preferably greater than 800,000; preferably less than 1 million, and more preferably It is preferably less than 950,000, more preferably less than 900,000. The molecular weight distribution (Mw/Mn) of the (A2) polymer component is 3.0 or less, preferably 2.5 or less, more preferably 2.2 or less, more preferably 1.8 or less.

The ratio (Mw1/Mw2) of the weight average molecular weight (Mw1) of the polymer component (A1) to the weight average molecular weight (Mw2) of the polymer component (A2) (Mw1/Mw2) is preferably 1.5 or more, more preferably 2.0 or more; preferably It is less than 4.0, more preferably less than 3.0. When the ratio (Mw1/Mw2) is within the above range, a more flexible adhesive material with excellent recovery properties can be formed. When plural (A1) polymer components or (A2) polymer components are contained, the said ratio (Mw1/Mw2) means the ratio of the maximum weight average molecular weight in each said component.

The mass ratio (A1/A2) of (A1) polymer component to (A2) polymer component in the aforementioned (A) polymer component is preferably 0.1 or more, more preferably 0.2 or more, more preferably 0.3 or more; Preferably, it is 1.0 or less, more preferably 0.8 or less, still more preferably 0.6 or less. When the mass ratio (A1/A2) is within the above range, a more flexible adhesive material with excellent recovery properties can be formed. When plural (A1) polymer components or (A2) polymer components are contained, the said ratio (A1/A2) means the mass ratio of the polymer component with the largest weight average molecular weight among each of these components.

((B) (meth)acrylic copolymer component) The aforementioned (B) (meth)acrylic copolymer component may be a structural unit derived from a (meth)acrylic monomer as the main component (50% by mass or more) of copolymers. The aforementioned (B) polymer component may be one type, or two or more types. In addition, the (B) polymer component may contain a structural unit derived from a vinyl monomer other than a (meth)acrylic monomer, and in the (B) polymer component, a structural unit derived from a (meth)acrylic monomer The content of is preferably at least 80% by mass, and more preferably at least 90% by mass in 100% by mass of the polymer component. This (B) polymer component may consist only of the structural unit derived from a (meth)acrylic monomer.

The above-mentioned (B) polymer component is preferably a (meth)acrylate copolymer, and the (meth)acrylate copolymer may be a structural unit derived from (meth)acrylate as the main component (50% by mass or more) and may contain copolymers of structural units derived from vinyl monomers other than (meth)acrylates. The (B) polymer component has a content rate of a structural unit derived from (meth)acrylate, based on 100% by mass of the polymer component, preferably at least 80% by mass, more preferably at least 90% by mass.

The aforementioned (B) polymer component has a first reactive group that is a functional group having high reactivity with a second reactive group that a crosslinking agent described later has. The functional group that can be used as the first reactive group includes a reactive functional group. The first reactive group is preferably a hydroxyl group and/or a carboxyl group, more preferably a hydroxyl group or a carboxyl group.

The amount of the first reactive group of the aforementioned (B) polymer component is preferably at least 0.002 mmol/g, more preferably at least 0.006 mmol/g, more preferably at least 0.01 mmol/g; preferably at most 0.8 mmol/g , more preferably 0.6 mmol/g or less, more preferably 0.5 mmol/g or less, particularly preferably 0.2 mmol/g or less, most preferably 0.1 mmol/g or less. When the amount of the first reactive group is more than 0.002 mmol/g, the formed adhesive material is properly cross-linked and exhibits an ideal recovery rate; when it is less than 0.8 mmol/g, the formed adhesive material has Sufficient distance and excellent flexibility.

The aforementioned (B) polymer component preferably has a hydroxyl group as the first reactive group, and also contains a carboxyl group as a functional group other than the first reactive group. At this time, the amount of carboxyl groups in the (B) copolymer is preferably at least 0.08 mmol/g, more preferably at least 0.16 mmol/g, more preferably at least 0.32 mmol/g; preferably at most 1.3 mmol/g, and even more preferably It is 0.8 mmol/g or less, more preferably 0.6 mmol/g or less.

When the aforementioned (B) polymer component uses hydroxyl as the first reactive group and contains both carboxyl and hydroxyl groups, the molar ratio (carboxyl/hydroxyl) of the carboxyl and hydroxyl per unit mass of (B) polymer component is preferably 4 or more, more preferably 8 or more, more preferably 16 or more; preferably less than 60, more preferably less than 40, more preferably less than 30. When the molar ratio (carboxyl group/hydroxyl group) is within the above range, the adhesive layer has high recovery and achieves an ideal balance of adhesive force and softness.

The aforementioned (B) polymer component preferably has a carboxyl group as the first reactive group, and also contains a hydroxyl group as a functional group other than the first reactive group. In this case, the amount of hydroxyl groups of the (B) polymer component is preferably at least 0.01 mmol/g, more preferably at least 0.02 mmol/g, more preferably at least 0.04 mmol/g; preferably at most 0.25 mmol/g, More preferably, it is not more than 0.20 mmol/g, more preferably not more than 0.15 mmol/g.

When the aforementioned (B) polymer component has a carboxyl group as the first reactive group and contains both a carboxyl group and a hydroxyl group, the molar ratio (carboxyl group/hydroxyl group) of the carboxyl group and hydroxyl group per unit mass of the (B) polymer component is preferably Above 3.0, more preferably above 3.5, more preferably above 4.0; preferably below 30, more preferably below 25, more preferably below 20. When the molar ratio (carboxyl group/hydroxyl group) is within the above range, the adhesive layer has high recovery and achieves an ideal balance of adhesive force and softness.

The aforementioned (B) polymer component can be any of random copolymers, block copolymers or graft copolymers, preferably random copolymers.

The weight average molecular weight (Mw) of the aforementioned (B) polymer component is preferably more than 100,000, more preferably more than 200,000, more preferably more than 300,000, particularly preferably more than 400,000; preferably less than 3 million, and more preferably It is preferably less than 1 million, more preferably less than 800,000. When the Mw of the (B) polymer component is 100,000 or more, the cohesive force increases, and the heat resistance of the formed adhesive material improves; and when it is 3,000,000 or less, the coating workability of the adhesive composition becomes better. The method of measuring the weight average molecular weight (Mw) will be described later.

The molecular weight distribution (Mw/Mn) of the aforementioned (B) polymer component is greater than 3.0, preferably greater than 5.0, more preferably greater than 7.0; preferably less than 12.0, more preferably less than 11.0, and more preferably less than 10.0. When Mw/Mn is greater than 3.0, an adhesive material having excellent adhesive force and flexibility can be formed.

The glass transition temperature (Tg) of the aforementioned (B) polymer component is preferably above -70°C, more preferably above -60°C; preferably below 0°C, more preferably below -10°C, and more preferably below -10°C. Preferably below -20°C. When the Tg is above -70°C, the adhesive material will obtain sufficient cohesion, and the durability of the adhesive material formed will be improved, and when the Tg is below 0°C, the adhesion between the adhesive material formed and the adherend will be improved, Suppresses peeling at low temperatures and improves durability.

The plurality of (meth)acrylic copolymer components include at least (A) (meth)acrylic copolymer components and (B) (meth)acrylic copolymer components.

Among the plurality of (meth)acrylic copolymer components, the content of the (A) (meth)acrylic copolymer component is at least 75% by mass, preferably at least 77% by mass, and more preferably at least 80% by mass. ; Its content rate is 99% by mass or less, preferably 97% by mass or less, more preferably 95% by mass or less. When the content of the (A) (meth)acrylic copolymer component is 75% by mass or more, an adhesive material with excellent recovery rate can be formed, and when it is 99% by mass or less, an adhesive material with excellent adhesive force and flexibility can be formed .

Among the plurality of (meth)acrylic copolymer components, the content of the (B) (meth)acrylic copolymer component is at least 1% by mass, preferably at least 3% by mass, and more preferably at least 5% by mass. above; its content is 25% by mass or less, preferably 23% by mass or less, and more preferably 20% by mass or less. When the content of the (B) (meth)acrylic copolymer component is 1% by mass or more, an adhesive material with excellent adhesive force and flexibility can be formed, and when it is 25% by mass or less, an adhesive material with excellent recovery rate can be formed .

Among the plurality of (meth)acrylic copolymer components, the total content of the (A) (meth)acrylic copolymer component and the (B) (meth)acrylic copolymer component is preferably 80% % by mass or more, more preferably at least 90% by mass, more preferably at least 95% by mass. The (meth)acrylic copolymer component preferably contains only the (A) (meth)acrylic copolymer component and (B) (meth)acrylic copolymer component.

Among the plurality of (meth)acrylic copolymer components, the mass ratio (A/B) of the (A) polymer component to (B) polymer component is preferably 3 or more, more preferably 4 or more, and more preferably 5 or more; preferably 25 or less, more preferably 20 or less, more preferably 15 or less. When the mass ratio (A/B) is 3 or more, an adhesive material with excellent recovery rate can be formed, and when the mass ratio (A/B) is 25 or less, an adhesive material with excellent adhesive force and flexibility can be formed.

The aforementioned plural (meth)acrylic copolymer components may contain other polymer components other than the aforementioned (A) polymer component and (B) polymer component. The aforementioned other polymer components, for example, include (meth)acrylic copolymer components without the first reactive group.

Hereinafter, the structural unit which comprises said (A) polymer component, (B) polymer component, and other polymer components is demonstrated.

The aforementioned (A) polymer component and (B) polymer component have a first reactive group, in other words, the structure of the (A) polymer component and (B) polymer component contains a structural unit with a first reactive group ( a-1). The structural unit (a-1) having the first reactive group may have only one kind of first reactive group, or may have two or more kinds of first reactive groups. The first reactive group can be derived from a structural unit of a (meth)acrylic monomer (preferably a (meth)acrylate monomer and/or (meth)acrylic acid), from a non-(meth)acrylic monomer Included in any of the structural units of other vinyl monomers. That is, the structural unit (a-1) having the first reactive group may be derived from a (meth)acrylic monomer (using (meth)acrylate monomer and/or (meth) ) acrylic acid, preferably), or a structural unit derived from a vinyl monomer other than a (meth)acrylic monomer having a first reactive group.

In the aforementioned (A) polymer component, the content rate of the structural unit derived from the vinyl monomer having the first reactive group (the structural unit (a-1) having the first reactive group) is based on 100 mass of the polymer component %, preferably at least 0.03% by mass, more preferably at least 0.09% by mass, more preferably at least 0.15% by mass; preferably less than 6% by mass, more preferably less than 3% by mass, more preferably less than 1% by mass. In the (A) polymer component, when the content of the structural unit (a-1) is within the above range, an adhesive material with an excellent balance of adhesion and durability to the adherend can be formed. Wherein, the vinyl monomer having the first reactive group includes the (meth)acrylic monomer having the first reactive group, and the vinyl monomer other than the (meth)acrylic monomer having the first reactive group monomer.

In the above-mentioned (B) polymer component, the content rate of the structural unit derived from the vinyl monomer having the first reactive group (the structural unit (a-1) having the first reactive group) is based on 100 mass of the polymer component %, preferably at least 0.03% by mass, more preferably at least 0.09% by mass, more preferably at least 0.15% by mass; preferably at most 6% by mass, even more preferably at most 3% by mass, more preferably at most 1% by mass. In the (B) polymer component, when the content of the structural unit (a-1) is within the above range, an adhesive material with an excellent balance of adhesion and durability to the adherend can be formed. Wherein, the vinyl monomer having the first reactive group includes the (meth)acrylic monomer having the first reactive group, and the vinyl monomer other than the (meth)acrylic monomer having the first reactive group monomer.

The aforementioned (meth)acrylic monomers include (b1) (meth)acrylic monomers that do not have a functional group that can be used as the first reactive group, and (b2) (b2) that have a functional group that can be used as the first reactive group ( As for the meth)acrylic monomer, these monomers may be used alone or in combination of two or more. The (b1) (meth)acrylic monomer that does not have a functional group that can serve as a first reactive group is represented by (b1-1) a (meth)acrylate monomer that does not have a functional group that can serve as a first reactive group. good. The (b2) (meth)acrylic monomer having a functional group that can serve as a first reactive group includes (b2-1) a (meth)acrylate monomer having a functional group that can serve as a first reactive group, and (meth)acrylic acid.

The aforementioned (b1) (meth)acrylic monomers that do not have a functional group that can serve as the first reactive group include (meth)acrylates with straight-chain alkyl groups and (meth)acrylates with branched-chain alkyl groups , (meth)acrylates with alkoxy groups, (meth)acrylates with polyalkylene glycol structural units, (meth)acrylates with alicyclic hydrocarbon groups, (meth)acrylates with aromatic groups Acrylates, (meth)acrylates with tertiary amino groups, (meth)acrylamides, etc. Among them, it is selected from (meth)acrylates with straight-chain alkyl groups, (meth)acrylates with branched-chain alkyl groups, (meth)acrylates with alicyclic hydrocarbon groups, and (meth)acrylates with aromatic groups ( At least one selected from the group consisting of meth)acrylate and (meth)acrylamide is preferred.

The above-mentioned (meth)acrylate with a straight-chain alkyl group is preferably a (meth)acrylate with a straight-chain alkyl group having 1 to 20 carbon atoms, and more preferably a straight-chain alkyl group. A (meth)acrylate with a straight-chain alkyl group with 1 to 15 carbon atoms, more preferably a (meth)acrylate with a straight-chain alkyl group with a straight-chain alkyl group with 8 to 15 carbon atoms . The (meth)acrylates with linear alkyl groups include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate and (meth)acrylate base) n-hexyl acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-lauryl (meth)acrylate, n-octadecyl (meth)acrylate Linear alkyl (meth)acrylates such as alkyl esters.

The aforementioned (meth)acrylate with branched chain alkyl group is preferably a (meth)acrylate ester with branched chain alkyl group having a branched chain alkyl group with 3 to 20 carbon atoms, preferably a branched chain alkyl group (meth)acrylates with branched chain alkyl groups having 3 to 10 carbon atoms. The (meth)acrylates with branched chain alkyl include isopropyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, third butyl (meth)acrylate branched alkyl (meth)acrylates such as isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate and isodecyl (meth)acrylate ester.

The aforementioned (meth)acrylates having alkoxy groups include alkoxyalkyl (meth)acrylates such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate.

The aforementioned (meth)acrylates with polyalkylene glycol structural units include polyethylene glycol (polymerization degree=2~10) methyl ether (meth)acrylate, polyethylene glycol (polymerization degree=2~10) 10) Ether (meth)acrylate and polyethylene glycol, polyethylene glycol (polymerization degree=2~10) propyl ether (meth)acrylate, polyethylene glycol (polymerization degree=2~10) phenyl ether (Meth) acrylate, etc., (meth) acrylate with polyethylene glycol structural unit; polypropylene glycol (polymerization degree = 2~10) methyl ether (meth) acrylate, polypropylene glycol (polymerization degree = 2~10) 10) Ether (meth)acrylate, polypropylene glycol (polymerization degree = 2~10) propyl ether (meth)acrylate, polypropylene glycol (polymerization degree = 2~10) phenyl ether (meth)acrylate, etc., with (Meth)acrylate of polypropylene glycol structural unit.

The aforementioned (meth)acrylates with alicyclic hydrocarbon groups include (meth)acrylates with cyclic alkyl groups and (meth)acrylates with polycyclic structures. The aforementioned (meth)acrylate having a cyclic alkyl group is preferably a (meth)acrylate having a cyclic alkyl group having 6 to 12 carbon atoms. The cyclic alkyl group includes a cyclic alkyl group having a monocyclic structure (such as a cycloalkyl group), and may additionally have a chain part. (Meth)acrylic acid esters of cyclic alkyl groups with a monocyclic structure, specific examples include cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, cyclohexyl (meth)acrylate, Cyclic alkyl (meth)acrylate such as lauryl ester.

The aforementioned (meth)acrylate having a polycyclic structure is preferably a (meth)acrylate having a polycyclic structure with 6 to 12 carbon atoms. Polycyclic structures include cyclic alkyl groups with bridged ring structures (such as adamantyl, norbornyl, and isobornyl groups), and may also have chain parts. (Meth)acrylates with polycyclic structures, specific examples that can be mentioned include bornyl (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2- Adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, (meth)acrylic acid Bornyl ester, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate Wait.

The aforementioned (meth)acrylate having an aromatic group is preferably a (meth)acrylate having an aromatic group having 6 to 12 carbon atoms. The aromatic group includes an aryl group, and may additionally have a chain portion such as an alkaryl group, an aralkyl group, or an aryloxyalkyl group. The (meth)acrylates with aromatic groups include compounds in which aryl groups are directly bonded to (meth)acryloxy groups, compounds in which aralkyl groups are directly bonded to (meth)acryloxy groups, and alkaryl groups. A compound in which a (meth)acryloyloxy group is directly bonded. The number of carbon atoms in the aryl group is preferably 6-12, the number of carbon atoms in the aralkyl group is preferably 6-12, and the number of carbon atoms in the alkaryl group is preferably 6-12. Specific examples of (meth)acrylates having an aromatic group include benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, and the like.

The aforementioned (meth)acrylates with tertiary amino groups include 2-(dimethylamino)ethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate.

The aforementioned (meth)acrylamides include N, N-dimethyl (meth)acrylamide, N, N-diethyl (meth)acrylamide, N, N-diisopropyl ( Meth)acrylamide, (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide Amine, N-tertiary-butyl(meth)acrylamide, N-octyl(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-ethoxyformyl (meth)acrylamide, N-propoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, diacetoneacrylamide, 4-(methyl) ) acryloylmorpholine, etc. Although the (meth)acrylamides are (meth)acrylic monomers, they are not included in the range of (meth)acrylate monomers.

The aforementioned (b2) (meth)acrylic monomers having a functional group that can serve as the first reactive group include (meth)acrylic monomers with hydroxyl groups (preferably (meth)acrylate monomers), Carboxylic (meth)acrylic monomers (preferably (meth)acrylic acid), (meth)acrylic monomers with epoxy groups (preferably (meth)acrylate monomers), etc. Among them, a (meth)acrylic monomer having a hydroxyl group and/or a (meth)acrylic monomer having a carboxyl group are preferred, and a (meth)acrylic monomer having a hydroxyl group is more preferred.

The aforementioned (meth)acrylic acid monomers with hydroxyl include 2-hydroxyl (meth)acrylate ethyl, 3-hydroxyl (meth)acrylate, 2-hydroxyl (meth)acrylate, 4-hydroxyl ( Butyl methacrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate Hydroxyalkyl(meth)acrylates; Methyl(4-hydroxymethylcyclohexyl)(meth)acrylates; Hydroxyalkylcycloalkyl(meth)acrylates; Hydroxyalkyl(meth)acrylates caprolactone adducts, etc. Among them, hydroxyalkyl (meth)acrylate is preferred, and (meth)acrylate having 1 to 5 carbon atoms and a hydroxyalkyl group is more preferred.

The aforementioned carboxyl-containing (meth)acrylic acid monomers include carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloxyethyl succinate and 2-( (meth)acrylic acid esters with hydroxyl groups such as meth)acryloxyethyl maleate and 2-(meth)acryloxyethyl phthalate, and maleic anhydride, succinic anhydride or Monomers obtained from the reaction of acid anhydrides such as phthalic anhydride (such as hydrogen succinate 2-acryloxyethyl, hydrogen succinate 2-methacryloxyethyl, hydrogen hexahydrophthalate 2- (Acryloxy)ethyl, 2-(methacryloxyethyl)hexahydrophthalate hydrogen, 1-(2-acryloxyethyl)phthalate, 1-phthalate - (2-methacryloxyethyl)), (meth)acrylic acid, etc., especially (meth)acrylic acid.

The aforementioned (meth)acrylates with epoxy groups include glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and the like.

Vinyl monomers other than the aforementioned (meth)acrylic monomers include (b3) vinyl monomers other than (meth)acrylic monomers that do not have a functional group that can serve as the first reactive group, and (b4) vinyl monomers other than A vinyl monomer other than a (meth)acrylic monomer having a functional group that can serve as a first reactive group. These monomers may be used alone or in combination of two or more.

The aforementioned (b3) vinyl monomers other than (meth)acrylic monomers that do not have a functional group that can serve as the first reactive group include aromatic vinyl monomers, vinyl monomers containing heterocycles, vinyl carboxylate Esters, vinyl monomers containing tertiary amino groups, vinyl monomers containing quaternary ammonium groups, vinyl amides, α-olefins, dienes, vinyl halide monomers, etc.

The aforementioned aromatic vinyl monomers include styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methoxystyrene, 2-hydroxy Methylstyrene, 1-vinylnaphthalene, etc. The aforementioned vinyl monomers containing heterocycles include 2-vinylthiophene, N-methyl-2-vinylpyrrole, 2-vinylpyridine, 4-vinylpyridine, etc. The aforementioned vinyl carboxylate includes vinyl acetate, vinyl pivalate, vinyl benzoate and the like. The aforementioned vinyl monomers containing tertiary amino groups include N, N-dimethylallylamine, etc. The aforementioned vinyl monomers containing quaternary ammonium bases include N-methacrylaminoethyl-N, N, N-dimethylbenzyl ammonium chloride, etc. The aforementioned vinyl amides include N-vinylformamide, N-vinylacetamide, 1-vinyl-2-pyrrolidone, N-vinyl-ε-caprolactam, etc. The aforementioned α-olefins include 1-hexene, 1-octene, 1-decene and the like. The aforementioned dienes include butadiene, isoprene, 4-methyl-1,4-hexadiene, 7-methyl-1,6-octadiene and the like. The aforementioned vinyl halide monomers include vinyl fluoride, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, tetrafluoropropylene, vinylidene chloride, vinyl chloride, 1-chloro-1 -Fluoroethylene, 1,2-dichloro-1,2-difluoroethylene, etc.

The aforementioned (b4) vinyl monomers other than (meth)acrylic monomers having functional groups that can serve as the first reactive group include vinyl monomers with hydroxyl groups, vinyl monomers with carboxyl groups, and epoxy-containing monomers. Vinyl monomers, etc.

The aforementioned hydroxyl-containing vinyl monomers include p-hydroxystyrene, allyl alcohol, and the like. The aforementioned vinyl monomers with carboxyl groups include crotonic acid, maleic acid, itaconic acid, citraconic acid, cinnamic acid, etc. The aforementioned vinyl monomers containing epoxy groups include 2-allyl oxirane, glycidyl vinyl ether, 3, 4-epoxycyclohexyl vinyl ether, etc.

(Preparation of (meth)acrylic copolymer mixture) The aforementioned (meth)acrylic copolymer mixture can be adjusted, for example, by mixing a plurality of (meth)acrylic copolymer components, the (meth) Acrylic copolymers can be obtained by polymerization of (meth)acrylic monomers. The polymerization initiator can be added batchwise or continuously during polymerization to obtain a polymer composition containing multiple polymer components. Such a polymer composition can be used as multiple (meth)acrylic copolymer components. In addition, the distribution curve of the molecular weight can be drawn by gel permeation chromatography, and the waveform separation of the curve can be used to confirm the polymer components contained in the polymer composition or the (meth)acrylic copolymer mixture.

The polymerization method used for polymerizing the aforementioned monomer composition may be any of radical polymerization or living radical polymerization.

(Living radical polymerization method) The living radical polymerization method not only maintains the convenience and versatility of the existing radical polymerization method, but also does not easily cause chain termination or chain transfer, and the growth of polymer chains is not affected by the deactivation of the growth terminal. Hindered by the side reactions, it is easy to achieve precise control of the molecular weight distribution and produce a polymer with uniform composition; thus, in the copolymer prepared by the living radical polymerization method, the reactive functional groups are evenly distributed in each molecular chain superior. Random copolymers can be obtained by using a mixture of monomers (vinyl monomers) in the living radical polymerization method; block copolymers can also be obtained by sequentially reacting the vinyl monomers constituting the copolymer.

In the living radical polymerization method, depending on the method of stabilizing the growth end of the polymer, there is a method of using a compound capable of generating nitrogen and oxygen radicals (nitrogen-oxygen-mediated polymerization method; NMP method); using metal complexes such as copper or ruthenium A method of living polymerization starting from a halogenated compound as a polymerization initiator compound (ATRP method); a method of using a sulfur-based reversible chain transfer reagent (RAFT method); a method of using an organic telluride (TERP method); method of using organic iodine compound (ITP method); method of using iodine compound as polymerization initiator compound, organic compound such as phosphorus compound, nitrogen compound, oxygen compound or hydrocarbon as catalyst (reversible chain transfer catalyst polymerization, RTCP method, reversible catalyst media polymerization, RCMP method) and other methods. Among these methods, the TERP method is preferable from the viewpoint of diversity of applicable monomers, control of molecular weight in the polymer field, uniformity of composition, and coloring.

The TERP method uses an organic telluride as a chain transfer agent to polymerize a radically polymerizable compound (vinyl monomer). For example, International Publication No. 2004/14848, International Publication No. 2004/14962, Publication No. 2004/072126 and the method disclosed in International Publication No. 2004/096870.

Specific polymerization methods of the TERP method include the following (a) to (d) methods. (a) A method of polymerizing a vinyl monomer using an organotelluride represented by formula (1). (b) A method of polymerizing a vinyl monomer by using a mixture of an organic telluride represented by formula (1) and an azo polymerization initiator. (c) A method of polymerizing a vinyl monomer using a mixture of an organic telluride represented by formula (1) and an organic ditelluride represented by formula (2). (d) A method of polymerizing a vinyl monomer by using a mixture of an organic telluride represented by formula (1), an azo polymerization initiator, and an organic ditelluride represented by formula (2).

[式(1)中，R ¹為具有1~8個碳原子的烷基、芳基或芳香族雜環基。R ²和R ³分別獨立為氫原子或具有1~8個碳原子的烷基。R ⁴為具有1~8個碳原子的烷基、芳基、取代芳基、芳香族雜環基、烷氧基、醯基、醯胺基、苯甲氧羰基、氰基、丙烯基或炔丙基。式(2)中，R ¹為具有1~8個碳原子1~8的烷基、芳基或芳香族雜環基。] [chemical 1]

[In the formula (1), R ¹ is an alkyl, aryl or aromatic heterocyclic group having 1 to 8 carbon atoms. R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R is an alkyl group, aryl group, substituted aryl group, aromatic heterocyclic group, alkoxy group, acyl group, amido group, benzyloxycarbonyl group, cyano group, propenyl group or alkyne group with ¹ to 8 carbon atoms Propyl. In formula (2), R ¹ is an alkyl, aryl or aromatic heterocyclic group having 1 to 8 carbon atoms. ]

The organotellurium compound shown in formula (1) specifically includes ethyl=2-methyl-2-n-butyltelluryl-propionate, ethyl=2-n-butyltelluryl-propionate, (2 -Hydroxyethyl)=2-methyl-methyl tellurium hydrogen-propionate, etc. are disclosed in International Publication No. 2004/14848, International Publication No. 2004/14962, International Publication No. 2004/072126 and International Publication No. 2004 Organotellurium compounds in No./096870. Specific examples of the organic ditelluride represented by formula (2) include dimethyl ditelluride, dibutyl ditelluride, and the like. The azo polymerization initiator is not particularly limited, as long as it is an azo polymerization initiator used in general free radical polymerization, including 2, 2'-azobis(isobutyronitrile) (AIBN) , 2, 2'-Azobis(2, 4-dimethylvaleronitrile) (ADVN), 1, 1'-Azobis(1-cyclohexanenitrile) (ACHN), 2, 2'-Azo Bis(4-methoxy-2,4-dimethylvaleronitrile) (V-70), etc.

The polymerization step is carried out in a container that has been replaced with an inert gas. The vinyl monomer and the organotelluride of formula (1) are mixed, and according to the type of the vinyl monomer, the purpose of promoting the reaction, controlling the molecular weight and molecular weight distribution, etc. is considered. Further, an azo-based polymerization initiator and/or an organic ditelluride compound of formula (2) are mixed. The inert gas includes nitrogen, argon, helium, etc., preferably argon and nitrogen. The amount of vinyl monomer used in (a), (b), (c) and (d) above can be properly adjusted according to the physical properties of the target copolymer.

The polymerization reaction can be carried out without a solvent, and can also be carried out by stirring the aforementioned mixture using an aprotic solvent or a protic solvent generally used in radical polymerization. Useful aprotic solvents include acetonitrile, methyl ethyl ketone, anisole, benzene, toluene, propylene glycol monomethyl ether acetate, ethyl acetate, tetrahydrofuran (THF), N,N-dimethylformamide (DMF), Dimethylsulfone (DMSO), N-methyl-2-pyrrolidone (NMP), acetone, dioxane, chloroform, carbon tetrachloride, etc. Protic solvents include water, methanol, ethanol, isopropanol, n-butanol, ethyl celuso, butyl celuso, 1-methoxy-2-propanol, hexafluoroisopropanol, diacetone alcohol Wait. A solvent may be used individually or in combination of 2 or more types. The amount of solvent used can be adjusted appropriately, for example, for 1g of vinyl monomer, 0.01ml~50ml of solvent is preferred. The reaction temperature and reaction time can be properly adjusted according to the molecular weight or molecular weight distribution of the available polymer components, and the stirring time is usually 1 minute to 100 hours at 0°C to 150°C. The polymerization reaction is usually carried out at 1 atmosphere, but it may also be carried out under increased pressure or reduced pressure. After the polymerization reaction is completed, the solvent used, residual vinyl monomer, etc. can be removed from the obtained reaction mixture by general separation and purification means, so as to isolate the target copolymer.

The copolymer that can be obtained by the polymerization reaction, the extended terminal is in the form of -TeR ¹ (in this formula, R ¹ is the same as the above) from the tellurium compound, although the extended terminal is deactivated due to the operation in the air after the polymerization reaction , but tellurium atoms sometimes remain, because the copolymer with residual tellurium atoms at the end is easy to be colored or has poor thermal stability, so it is better to remove tellurium atoms. Methods for removing tellurium atoms include free radical reduction, adsorption with activated carbon, and metal adsorption with ion-exchange resin, etc., and the above methods can also be used in combination. In addition, the other end of the copolymer obtained by the polymerization reaction (the end opposite to the growing end) is derived from a tellurium compound -CR ² R ³ R ⁴ (where R ² , R ³ and R ⁴ and R ² , R ³ and R ⁴ in formula (1) are the same).

(free radical polymerization method) As the radical polymerization method, conventionally known methods can be used. The polymerization initiators used in radical polymerization include azo-based polymerization initiators, peroxide-based polymerization initiators, and the like. The azo polymerization initiators include 2, 2'-azobis(isobutyronitrile) (AIBN), 2, 2'-azobis(2-methylbutyronitrile) (AMBN), 2, 2' - Azobis(2, 4-dimethylvaleronitrile) (ADVN), 1, 1'-azobis(1-cyclohexanenitrile) (ACHN), 2, 2'-azobisisobutyric acid dimethyl Esters (MAIB), 4, 4'-Azobis(4-cyanovaleric acid) (ACVA), 1, 1'-Azobis(1-acetyloxy-1-phenylethane), 2, 2'-Azobis(2-butyramide), 2, 2'-Azobis(4-methoxy-2, 4-dimethylvaleronitrile) (V-70), 2, 2'- Azobis(2-carboxamidinopropane) dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis[2 -Methyl-N-(2-hydroxyethyl)acrylamide], 2,2'-azobis(2,4,4-trimethylpentane), 2-cyano-2-propylazo Azodiamide, 2,2'-azobis(N-butyl-2-methylpropionamide), or 2,2'-azobis(N-cyclohexyl-2-methylpropionamide )Wait.

The polymerization reaction can be carried out without a solvent, and can also be carried out by stirring the aforementioned mixture using an aprotic solvent or a protic solvent generally used in radical polymerization. Available aprotic solvents can be for example acetonitrile, anisole, benzene, toluene, N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), N-methyl-2-pyrrolidone ( NMP), acetone, 2-butanone (methyl ethyl ketone), dioxane, propylene glycol monomethyl ether acetate, chloroform, carbon tetrachloride, tetrahydrofuran (THF), ethyl acetate, trifluorotoluene, etc. Protic solvents such as water, methanol, ethanol, isopropanol, n-butanol, ethyl celuso, butyl celuso, 1-methoxy-2-propanol, hexafluoroisopropanol, diacetone Alcohol etc.

The amount of solvent used should be properly adjusted. For example, for 1g of vinyl monomer, the amount of solvent is preferably more than 0.01ml, more preferably more than 0.05ml, more preferably more than 0.1ml; it is preferably less than 50ml, and more preferably It is less than 10ml, more preferably less than 1ml.

The reaction temperature and reaction time can be appropriately adjusted according to the molecular weight or molecular weight distribution of the target polymer component. At 0°C~150°C, the stirring time is usually 1 minute~100 hours. The polymerization reaction is usually carried out at 1 atmosphere, but it may also be carried out under increased pressure or reduced pressure. After the polymerization reaction is completed, the used solvent, residual vinyl monomer, etc. can be removed from the obtained reaction mixture by general separation and purification means to isolate the target copolymer.

(Cross-linking agent) The above-mentioned adhesive composition contains a cross-linking agent, which is a compound having two or more second reactive groups in one molecule, and the second reactive group and the above-mentioned (A) polymer The component reacts with the first reactive group contained in the (B) polymer component. The type of the cross-linking agent is not particularly limited, for example, including isocyanate cross-linking agent, epoxy cross-linking agent, aziridine cross-linking agent, metal chelate cross-linking agent, melamine resin cross-linking agent Linking agent, urea resin crosslinking agent, etc. The aforementioned cross-linking agents can be used alone or in combination of two or more, among which isocyanate cross-linking agents and/or epoxy cross-linking agents are better choices, especially for the purpose of improving the recovery rate of the formed adhesive From the point of view, I prefer isocyanate cross-linking agent or epoxy cross-linking agent, and prefer epoxy cross-linking agent.

The average number of the second reactive groups contained in each molecule of the aforementioned crosslinking agent is 2 or more, more preferably 3 or more, more preferably 4 or more, especially preferably 5 or more; and preferably 8 or less. That is, the selection of the cross-linking agent is more favorable to the multi-functional cross-linking agent having more than 4 second reactive groups in each molecule. If the cross-linking agent is more than 4 functional, the distance between the average cross-linking points in the polymer in the adhesive material is longer, so the obtained adhesive material has a lower initial stress and a higher recovery rate. The molecular weight of the crosslinking agent is preferably above 200, more preferably above 300, more preferably above 400; preferably below 1500, further preferably below 1000, more preferably below 700.

The content of the second reactive group in the crosslinking agent is preferably 1.5 mmol/g or more, more preferably 3.0 mmol/g or more, more preferably 3.7 mmol/g or more; preferably 10 mmol/g or less, and more preferably 8 mmol/g or less, more preferably 6 mmol/g or less. If the content of the second reactive group in the cross-linking agent is within this range, the valence of the cross-linking agent becomes lower, the cross-linking points are evenly distributed in the adhesive material, and the average distance between the cross-linking points becomes longer; therefore, the obtained The initial stress of the adhesive material becomes lower and the recovery rate is higher.

Examples of combinations of the first reactive group contained in the aforementioned (A) polymer component and (B) polymer component and the second reactive group contained in the crosslinking agent include the following combinations: The second reactive group in the crosslinking agent When the reactive group is an isocyanate group, the first reactive group can be a hydroxyl group; when the second reactive group in the crosslinking agent is an epoxy group, the first reactive group can be a carboxyl group.

The combination of the first reactive group contained in the aforementioned (A) polymer component and (B) polymer component and the second reactive group contained in the crosslinking agent is preferably the following combination: (1) the first reactive group The first reactive group is a hydroxyl group, and the second reactive group is an isocyanate group; (2) the first reactive group is a carboxyl group, and the second reactive group is an epoxy group.

(Isocyanate cross-linking agent) Isocyanate cross-linking agent has two or more isocyanate groups as the second reactive group in one molecule (including the isocyanate regeneration functional group temporarily protecting the isocyanate group by means of blocking agent or quantification) )compound of. The isocyanate crosslinking agent may be used alone or in combination of two or more.

Isocyanate crosslinking agents, including aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic polyisocyanate, and their adducts with various polyols, isocyanurate bonds, biuret bonds, allophanic acid Polyfunctional polyisocyanates such as ester bonds. Specifically, it includes compounds with two isocyanate groups in one molecule (including isocyanate regeneration functional groups that temporarily protect isocyanate groups by means of blocking agents or quantification) (difunctional isocyanate crosslinking agents), three in one molecule Compounds with two isocyanate groups (including isocyanate regeneration functional groups that temporarily protect isocyanate groups by means of blocking agents or quantification) (trifunctional isocyanate crosslinking agents), and six isocyanate groups in one molecule (including blocking agents) Or quantification, etc. temporarily protect the isocyanate group (isocyanate regeneration functional group) compound (hexafunctional isocyanate crosslinking agent), etc.

Difunctional isocyanate crosslinking agents include diisocyanate compounds such as aliphatic diisocyanate compounds, alicyclic diisocyanate compounds, and aromatic diisocyanate compounds, and adducts of these diisocyanate compounds and diol compounds can also be used. Diisocyanate compounds are compounds represented by the general formula "O=C=N-X-N=C=O" (X is a divalent aliphatic group, a divalent alicyclic group, a divalent aromatic group, etc.). The diol compound is a compound represented by the general formula "HO-Y-OH" (Y is a divalent aliphatic group, a divalent alicyclic group, a divalent aromatic group, etc.).

Aliphatic diisocyanate compounds, including ethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2-methyl-1, 5-pentane diisocyanate, 3-methyl- 1, 5-pentamethylene diisocyanate, 2, 2, 4-trimethyl-1, 6-hexamethylene diisocyanate, etc., among them, preferably aliphatic diisocyanate compounds with 4 to 30 carbon atoms, more preferably It is an aliphatic diisocyanate compound with 4 to 10 carbon atoms.

Cycloaliphatic diisocyanate compounds, including isophorone diisocyanate, cyclopentyl diisocyanate, cyclohexyl diisocyanate, hydrogenated xylene diisocyanate, hydrogenated toluene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tetramethylxylene Diisocyanates and the like, among which alicyclic diisocyanate compounds having 7 to 30 carbon atoms are preferred.

Aromatic diisocyanate compounds, including phenylene diisocyanate, toluene diisocyanate, xylylene diisocyanate, naphthalene diisocyanate, diphenyl ether diisocyanate, diphenylmethane diisocyanate, diphenylpropane diisocyanate, etc., wherein carbon atoms Aromatic diisocyanate compounds with a number of 8-30 are preferred.

The aforementioned diol compounds, including 2-methyl-1, 3-propanediol, 2, 2-dimethyl-1, 3-propanediol, 2-methyl-2-propyl-1, 3-propanediol, 2-ethane aliphatic diol compounds such as 2-butyl-1, 3-propanediol, 3-methyl-1, 5-pentanediol, 1, 6-hexanediol, polyethylene glycol and polypropylene glycol, among which carbon atoms The aliphatic diol compound with the number of 3-10 is preferred.

The aforementioned trifunctional isocyanate crosslinking agent and hexafunctional isocyanate crosslinking agent include the adduct of the aforementioned diisocyanate compound, the biuret body of the diisocyanate compound and the isocyanurate body of the diisocyanate compound (diisocyanate compound class of cyclic polymers), etc.

The aforementioned isocyanate crosslinking agent is preferably one without an aromatic ring, and the isocyanate crosslinking agent is especially selected from the group including aliphatic diisocyanate compounds, adducts of aliphatic diisocyanate compounds and aliphatic diol compounds, etc. The bifunctional isocyanate crosslinking agent; and selected from the group consisting of adducts of aliphatic diisocyanate compounds, biuret bodies of aliphatic diisocyanate compounds, and isocyanurate bodies of aliphatic diisocyanate compounds The trifunctional or hexafunctional isocyanate crosslinking agent in the group is preferred.

(Epoxy crosslinking agent) The epoxy crosslinking agent refers to a compound having two or more epoxy groups as the second reactive group in one molecule. The epoxy crosslinking agent may be used alone or in combination of two or more.

Epoxy crosslinking agents include aliphatic epoxy compounds, alicyclic epoxy compounds, aromatic epoxy compounds, and heterocyclic epoxy compounds.

The aforementioned aliphatic epoxy compounds, including ethylene glycidyl ether, trimethylolpropane diglycidyl ether, diglycidylamine, diamine glycidylamine, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether , propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, glycerol diglycidyl ether, triglyceride Glycidyl ether, polyglycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, diglycidyl adipate, 1, 3-bis(N, N-diglycidylaminomethyl) cyclohexane, etc. .

The aforementioned cycloaliphatic epoxy compounds include 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, N,N,N', N'-tetraglycidyl-m-xylylenediamine, etc.

The aforementioned aromatic epoxy compounds include bisphenol A epichlorohydrin type epoxy resin, diglycidyl aniline, diglycidyl phthalate, resorcinol diglycidyl ether, and bisphenol-S- diglycidyl ether etc.

The aforementioned heterocyclic epoxy compounds, including triglycidyl-tris(2-hydroxyethyl)isocyanurate, 1,3,5-tris-(2,3-epoxybutyl)-isocyanurate ester, 1, 3, 5-tris-(3, 4-epoxybutyl)-isocyanurate, 1, 3, 5-tris-(4, 5-epoxypentyl)-isocyanurate Esters, polyglycidyl sorbitol, etc.

The aforementioned epoxy cross-linking agent is a compound with two epoxy groups in one molecule (difunctional epoxy cross-linking agent), a compound with three epoxy groups in one molecule (trifunctional epoxy cross-linking agent) agent), or a compound with four epoxy groups in one molecule (tetrafunctional epoxy crosslinking agent) is preferred. If the crosslinking agent is a bifunctional epoxy crosslinking agent, trifunctional epoxy crosslinking agent or tetrafunctional epoxy crosslinking agent, since the crosslinking points are evenly distributed in the adhesive material, the average Since the distance becomes longer, an adhesive material with low initial stress and high recovery rate can be obtained.

The crosslinking agent contained in the adhesive composition is preferably only an isocyanate crosslinking agent or an epoxy crosslinking agent. When only isocyanate cross-linking agents are used, a difunctional isocyanate cross-linking agent containing only two isocyanate groups in one molecule, a trifunctional isocyanate cross-linking agent containing only three isocyanate groups in one molecule, or A hexafunctional isocyanate crosslinking agent containing only six isocyanate groups in one molecule is preferred. When only epoxy cross-linking agents are contained, bifunctional epoxy cross-linking agents containing only two epoxy groups in one molecule, trifunctional epoxy cross-linking agents containing only three epoxy groups in one molecule A crosslinking agent, or a tetrafunctional epoxy crosslinking agent containing only four epoxy groups in one molecule is preferred.

The content of the crosslinking agent in the adhesive composition is preferably at least 0.01 parts by mass, more preferably at least 0.05 parts by mass, and more preferably 0.1 parts by mass per 100 parts by mass of the plural (meth)acrylic copolymer components above; preferably less than 0.2 parts by mass, more preferably less than 0.17 parts by mass. When the content of the cross-linking agent is within the above range, the adhesive force and recovery rate can reach the ideal range.

The molar ratio of the second reactive group contained in the aforementioned crosslinking agent to the first reactive group contained in the plurality of (meth)acrylic copolymer components (the number of moles of the first reactive group/second The number of moles of reactive groups) is 1 or more, preferably 2 or more, more preferably 3 or more; preferably 70 or less, more preferably 15 or less, more preferably 10 or less, and most preferably 5 or less. When the molar ratio is 1 or more, the crosslinking agent is completely reacted, and the second reactive group has no remaining amount, and the recovery rate is high; when the molar ratio is 70 or less, the reaction can be fully carried out, and the recovery rate is high.

The molar ratio of the first reactive group in the aforementioned plurality of (meth)acrylic copolymer components to the blending amount (molar number) of the aforementioned crosslinking agent (the molar number of the first reactive group/cross-linking agent) The number of moles of the joint agent) is preferably more than 2, more preferably more than 3, more preferably more than 4; preferably less than 250, more preferably less than 18, more preferably less than 12, particularly preferably less than 11, and most preferably preferably below 8. When the molar ratio is within the above range, the adhesive force and recovery rate can reach the ideal range.

(Other additives) In addition to the above-mentioned copolymer component and crosslinking agent, other additives may be blended into the above-mentioned adhesive composition. Such other additives include cross-linking accelerators, cross-linking retarders, tackifying resins (tackifiers), polymerizable compounds, photopolymerization initiators, silane coupling agents, plasticizers, softeners, and release aids , dyes, pigments, pigments, fluorescent whitening agents, antistatic agents, wetting agents, surfactants, thickeners, antifungal agents, preservatives, deoxidizers, ultraviolet absorbers, antioxidants, near-infrared absorbers , water-soluble matting agent, fragrance, metal deactivator, nucleating agent, alkylating agent, flame retardant, lubricant, processing aid, etc., are properly selected and blended according to the application and purpose of the adhesive material.

(Crosslinking Accelerator) The aforementioned adhesive composition may be used by blending a crosslinking accelerator as required. The cross-linking accelerator includes organotin compounds and metal chelates, and the cross-linking accelerator can be used alone or in combination of two or more.

The aforementioned organotin compounds include dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dioctoate. The aforementioned metal chelates are complexes in which the ligands with two or more coordinating atoms form a ring and combine with the central metal.

The content of the crosslinking accelerator in the adhesive composition is preferably at least 0.01 parts by mass, more preferably at least 0.02 parts by mass, and more preferably at least 0.04 parts per 100 parts by mass of the aforementioned plural (meth)acrylic copolymer components. More than 0.5 parts by mass, preferably less than 0.4 parts by mass, more preferably less than 0.3 parts by mass. When the content of the crosslinking accelerator is within the above range, an excellent crosslinking accelerating effect can be obtained.

(Cross-linking retarder) The aforementioned adhesive composition may be used by blending a cross-linking retarder as required. The cross-linking retarder is a compound capable of inhibiting excessive increase in viscosity of the adhesive composition containing the cross-linking agent by blocking the functional groups contained in the cross-linking agent. The type of cross-linking retarder is not particularly limited, for example, acetylacetone, hexane-2, 4-dione, heptane-2, 4-dione, octane-2, 4-dione can be used and other β-diketones; methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, ethyl acetoacetate β-keto esters such as stearyl acetate; and benzoyl acetone, etc. The cross-linking retarders are preferably β-diketones and β-ketoesters capable of acting as chelating agents.

The content of the crosslinking retardant blended with the adhesive composition is preferably at least 0.1 parts by mass, more preferably at least 0.2 parts by mass, per 100 parts by mass of the aforementioned plurality of (meth)acrylic copolymer components , more preferably 0.5 mass parts or more; preferably 4.0 mass parts or less, more preferably 3.0 mass parts or less, more preferably 1.5 mass parts or less. By adjusting the content of the cross-linking retarder within the above-mentioned range, after the cross-linking agent is blended into the adhesive composition, the excessive increase in viscosity or gelation of the adhesive composition can be suppressed, and the adhesive composition can be prolonged. Storage stability (pot life).

(Tackifying Resin) The aforementioned adhesive composition may be blended with a tackifying resin that does not contain the aforementioned copolymer component as required. The tackifying resin is not particularly limited, and includes, for example, rosin-based tackifying resins, terpene-based tackifying resins, phenolic-based tackifying resins, hydrocarbon-based tackifying resins, and the like.

Rosin tackifying resins include gum rosin, wood rosin, liquid rosin and other unmodified rosins (raw rosin), modified rosins obtained by modifying such unmodified rosins by means of polymerization, disproportionation or hydrogenation (polymerized rosin) , stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, other chemically modified rosin, etc.), and various other rosin derivatives.

The aforementioned rosin derivatives include rosin phenolic resins obtained by adding phenol to rosins (unmodified rosin, modified rosin) with an acid catalyst and thermally polymerizing them; esterifying unmodified rosin with alcohols Rosin ester compounds obtained (unmodified rosin esters) or modified rosin ester compounds obtained by esterifying modified rosins with alcohols (polymerized rosin esters, stabilized rosin esters, disproportionated rosin esters, fully hydrogenated rosin esters, partially hydrogenated rosin esters, etc.) and other rosin ester resins; unsaturated fatty acid modified rosin resins obtained by modifying unmodified rosin or modified rosin with unsaturated fatty acids; modified rosin resins obtained by modifying unsaturated fatty acids Unsaturated fatty acid modified rosin ester resin obtained; rosin obtained by reducing carboxyl groups in unmodified rosin, modified rosin, unsaturated fatty acid modified rosin resin, and unsaturated fatty acid modified rosin ester resin Alcohol-based resins; metal salts of rosin-based resins (especially rosin ester-based resins) such as unmodified rosin and modified rosin.

Terpene-based tackifying resins, including α-pinene polymers, β-pinene polymers, limonene polymers and other terpene-based resins, and will modify such terpene-based resins (phenol modified, aromatic modified terpene resins (such as terpene phenolic resins, styrene modified terpene resins, aromatic modified terpene resins, hydrogenated terpene resins).

Phenolic tackifying resins, including condensation products of various phenols (such as phenol, m-cresol, 3, 5-xylenol, p-alkylphenol, resorcinol) and formaldehyde (such as alkylphenol-formaldehyde resins, di Toluene formaldehyde resin), resole resin obtained by adding the above-mentioned phenols and formaldehyde with an alkali catalyst, and novolak obtained by condensing the above-mentioned phenols and formaldehyde with an acid catalyst, etc.

Hydrocarbon tackifying resins (petroleum tackifying resins), including, for example, aliphatic hydrocarbon resins [olefins and dienes with 4 to 5 carbon atoms (olefins such as 1-butene, isobutylene, and 1-pentene, etc.] ; butadiene, 1, 3-pentadiene, isoprene and other aliphatic hydrocarbon polymers], aliphatic cyclic hydrocarbon resins [the so-called "C4 petroleum fraction", "C5 petroleum fraction "Alicyclic hydrocarbon resins polymerized after cyclic dimerization, polymers of cyclic diene compounds (cyclopentadiene, dicyclopentadiene, ethylidene norbornene, limonene, etc.) or their hydrogenated products , the following aromatic hydrocarbon resins, aromatic ring hydrogenated alicyclic hydrocarbon resins of aliphatic and aromatic petroleum resins, etc.], aromatic hydrocarbon resins [aromatic hydrocarbons with 8 to 10 carbon atoms in the vinyl group ( Polymers of styrene, vinyltoluene, α-methylstyrene, indene, methylindene, etc.], aliphatic and aromatic petroleum resins (styrene-olefin copolymers, etc.), aliphatic and aliphatic Cyclic petroleum resins, hydrogenated hydrocarbon resins, lavone-based resins and lavone-indene resins, etc.

The content of the tackifying resin that can be blended with the adhesive composition is preferably at least 5 parts by mass, more preferably at least 10 parts by mass, and even more preferably at least 100 parts by mass of the aforementioned plural (meth)acrylic copolymer components. Preferably, it is 20 mass parts or more; More preferably, it is 60 mass parts or less, More preferably, it is 50 mass parts or less, More preferably, it is 40 mass parts or less. When the content of the tackifying resin is adjusted within the above range, sufficient adhesion with the adherend can be ensured.

(Polymerizable compound) The aforementioned adhesive composition may be blended with a polymerizable compound. By blending a polymeric compound and polymerizing the polymerizable compound in the adhesive, flexibility can be imparted to the adhesive.

The aforementioned polymerizable compound includes compounds having two or more polymerizable groups in one molecule. One of the polymerizable groups is an ethylenically unsaturated group, and this polymerizable compound may be used alone or in combination of two or more. The polymerizable compound includes compounds having two or more (meth)acryl groups, especially polyfunctional monomers and polyfunctional oligomers. The number of ethylenically unsaturated groups in one molecule of the polymerizable compound is preferably 2 or more and 4 or less, more preferably 3 or less.

The aforementioned compounds with two or more (meth)acryl groups include, for example, hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, Meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol Hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, isocyanuric acid ethylene oxide modified tri(meth)acrylic acid ester, allyl (meth)acrylate, vinyl (meth)acrylate and polyurethane (meth)acrylate, etc.

When the aforementioned adhesive composition is blended with the polymeric compound, the content of the polymeric compound is preferably at least 0.1 parts by mass, more preferably 2.5 parts per 100 parts by mass of the plurality of (meth)acrylic copolymer components. More than 100 parts by mass, more preferably less than 50 parts by mass.

(photopolymerization initiator) When curing the aforementioned polymerizable compound with active energy rays, it is preferable to blend the aforementioned adhesive composition with a photopolymerization initiator. The reaction when irradiated with active energy rays can be stabilized by blending the photopolymerization initiator. The photopolymerization initiator is not particularly limited as long as it generates free radicals by the action of light, such as acetophenones, benzoins, benzophenones, thioxanthones, acyl phosphine oxides, etc. Polymerization initiator. These photopolymerization initiators may be used alone or in combination of two or more. In addition, among these photopolymerization initiators, hydrogen abstraction type benzophenones and intramolecular cleavage type acetophenones are preferable from the viewpoint of effective intermolecular or intramolecular crosslinking.

When blending the adhesive composition and the photopolymerization initiator, the content of the photopolymerization initiator is preferably at least 0.01 parts by mass, more preferably It is at least 0.1 parts by mass, more preferably at least 0.5 parts by mass; preferably at most 10 parts by mass, further preferably at most 5 parts by mass, more preferably at most 2 parts by mass. When the content of the photopolymerization initiator is too small, the curing rate tends to decrease or the curing is insufficient, while if it is too large, the curability cannot be improved, and the economic efficiency is reduced.

In addition, the aforementioned adhesive composition may also be blended with the auxiliary agent of the aforementioned photopolymerization initiator. The additive can be used in combination such as triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler ketone), 4,4'-diethylaminobenzophenone, Ethyl 2-dimethylaminobenzoate and ethyl 4-dimethylaminobenzoate, (n-butoxy) ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 4-di 2-ethylhexyl methylaminobenzoate, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, etc. These auxiliary agents may be used alone or in combination of two or more.

(Silane Coupling Agent) The aforementioned adhesive composition may be mixed with a silane coupling agent as required. The silane coupling agent is not particularly limited, including 3-glycidoxypropyltrimethoxysilane, 3-epoxy Propoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4 epoxycyclohexyl)ethyltrimethoxysilane, etc. contain epoxy groups Silane coupling agent; 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N -(1,3-dimethylbutylene)propylamine, N-phenyl-γ-aminopropyltrimethoxysilane and other amino-containing silane coupling agents; 3-acryloxypropyltrimethoxysilane, 3 - Silane coupling agents containing (meth)acrylic groups such as methacryloxypropyl triethoxysilane; silane coupling agents containing isocyanate groups such as 3-isocyanate propyl triethoxysilane, etc.

Per 100 parts by mass of the plural (meth)acrylic copolymer components, the content of the silane coupling agent blended with the adhesive composition is at least 0.01 parts by mass, more preferably at least 0.02 parts by mass; It is preferably at most 1 part by mass, more preferably at most 0.6 part by mass. When the content of the silane coupling agent is adjusted within the above range, the water resistance of the interface when the adhesive is applied to a hydrophilic adherend such as glass can be improved.

(Plasticizer) The aforementioned adhesive composition may be blended with a plasticizer as required. The plasticizer is not particularly limited, and includes, for example, oils such as paraffin oil and processing oil; liquid rubber such as liquid polyisoprene, liquid polybutadiene, and liquid ethylene-propylene rubber; tetrahydrophthalic acid , azelaic acid, benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, butenedioic acid, maleic acid, itaconic acid, citric acid and such acids Derivatives: dioctyl phthalate (DOP), dibutyl phthalate (DBP), dioctyl adipate, diisononyl adipate (DINA) and isodecyl succinate, etc. . The plasticizer can be used alone or in combination; liquid rubber is especially preferred.

The weight average molecular weight (Mw) of the aforementioned liquid rubber is preferably not less than 5,000, more preferably not more than 10,000; preferably not more than 600 million, more preferably not more than 500 million. When the Mw of the liquid rubber is adjusted within the above range, an adhesive material having excellent flexibility can be formed. The method of measuring the weight average molecular weight (Mw) will be described later.

The content of the plasticizer that can be blended with the aforementioned adhesive composition is preferably at least 1 part by mass, more preferably at least 5 parts by mass, per 100 parts by mass of the plural (meth)acrylic copolymer components. More preferably at least 10 parts by mass; preferably at most 50 parts by mass, further preferably at most 40 parts by mass, more preferably at most 30 parts by mass. When the content of the plasticizer is adjusted within the above range, an adhesive material with excellent adhesion and recovery can be formed.

(Manufacturing method of adhesive composition) The aforementioned adhesive composition can be manufactured by mixing the aforementioned copolymer component, a crosslinking agent, and other additives used as required. The adhesive composition may contain a solvent from the production process of the copolymer component, and may further add an appropriate solvent to dilute it into a solution with a viscosity suitable for forming an adhesive layer.

The foregoing solvents include, for example, aliphatic hydrocarbons such as hexane and heptane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as dichloromethane and dichloroethane; acetone, methyl ethyl ketone, 2-pentanone, isofor Ketones such as ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; celuso solvents such as ethyl celuso; glycol ether solvents such as propylene glycol monomethyl ether. These solvents may be used alone or in combination of two or more.

The amount of the solvent used is not particularly limited, and can be appropriately adjusted so that the viscosity of the adhesive composition is suitable for coating, but from the viewpoint of coatability, for example, it is preferably 1% by mass to 90% by mass, and 10% by mass. The mass %-80 mass % is preferable, and 20 mass %-70 mass % is more preferable.

(Application of Adhesive Composition) A preferred application of the above-mentioned adhesive composition is to form an adhesive layer (adhesive material) used in a flexible display that can be repeatedly bent and stretched and used in a flexible display.

The aforementioned flexible displays that can be bent and stretched repeatedly include, for example, foldable foldable displays and rollable displays that can be rolled into a cylindrical shape. Flexible displays are expected to be used in mobile terminals such as smartphones and tablet terminals, as well as devices such as fixed displays that can be stored.

[Adhesive for flexible displays] The adhesive for flexible displays of the present invention is a cured product of the aforementioned adhesive composition. The adhesive material can be used for adhering one flexible component constituting the flexible display with other flexible components.

The gel fraction of the hardened product is preferably at least 50% by mass, more preferably at least 60% by mass, more preferably greater than 70% by mass, particularly preferably at least 75% by mass and not more than 100% by mass; the gel fraction When it is set in the said range, the adhesive material which has excellent flexibility and restoration|restorability can be formed. The gel fraction can be controlled through the blending amount of the cross-linking agent in the adhesive composition, the temperature of the cross-linking treatment, the time of the cross-linking treatment, and the like.

[Adhesive sheet for flexible display] The adhesive sheet for flexible display of the present invention has an adhesive layer for bonding one flexible member constituting the flexible display to another flexible member, and at least A flexible member attached to one side of the adhesive layer, wherein the adhesive layer is formed of the aforementioned adhesive material.

The structure of the aforementioned adhesive sheet includes an adhesive layer and a first flexible sheet member attached to one side of the adhesive layer; and a first flexible sheet member having an adhesive layer and attached to one side of the adhesive layer. A sheet-like member, and a second flexible sheet-like member attached to the other side of the adhesive layer.

Fig. 1 shows one embodiment of the adhesive sheet of the present invention. The adhesive sheet 10 in FIG. 1 is composed of an adhesive layer 12 , and a first flexible sheet member 14 and a second flexible sheet member 16 sandwiching the adhesive layer 12 . The adhesive layer 12 is in contact with the releasable surfaces of the first flexible sheet member 14 and the second flexible sheet member 16 .

(Adhesive Layer) The adhesive layer is formed of the aforementioned adhesive material. From the viewpoint of ensuring sufficient adhesion with the adherend, the film thickness of the adhesive layer is preferably at least 2 μm, more preferably at least 5 μm, and still more preferably at least 10 μm. On the other hand, from the viewpoint of suppressing overflow of the adhesive layer, the thickness of the adhesive layer is preferably at most 100 μm, more preferably at most 70 μm, and still more preferably at most 50 μm.

(Flexible sheet-like member) The above-mentioned flexible sheet-like member includes a flexible sheet-like base material, a release sheet, and the like. The sheet substrate is a sheet member supporting the adhesive layer, and the sheet member may be a functional sheet member. The functional sheet member includes a cover film, a barrier film, a polarizing film, a retardation film, an optical compensation film, a brightness enhancement film, a diffusion film, an antireflection film, and the like. The release sheet is used to protect the adhesive layer before the adhesive layer is attached to the adherend, and to be peeled off from the adhesive layer before the adhesive layer is attached to the adherend.

Generally speaking, "sheet" is defined by JIS as a thin and flat product whose thickness is usually small compared to its length and width, while "film" generally refers to its thickness is extremely small compared to its length and width. Thin and flat products whose maximum thickness is arbitrarily limited are usually provided in the form of cylindrical coils (Japanese Industrial Standard JIS K6900). In terms of thickness, for example, in a narrow sense, what has a thickness of 100 μm or more is called a sheet, and what has a thickness of less than 100 μm is called a film. However, since the boundary between the sheet and the film is not clear, there is no need to distinguish between the two in the present invention. Therefore, when the term "sheet" is used in the present invention, it already includes the meaning of "film". "This term also includes the meaning of "sheet".

The aforementioned flexible sheet member includes a sheet of polymer material, a glass sheet, and the like. The thickness of the flexible sheet is not particularly limited, but it is preferably 2 μm to 500 μm, more preferably 2 μm to 200 μm, from the viewpoint of excellent handleability.

The aforementioned polymer materials include polyimide resins; polyester resins such as polyethylene terephthalate resins and polyethylene naphthalate resins; polycarbonate resins; poly(meth)acrylate resins; Polystyrene resins; polyamide resins; polyacrylonitrile resins; polyolefin resins such as polypropylene resins, polyethylene resins, and polycycloolefin resins; polyphenylene sulfide resins; polyvinyl chloride resins; polyvinylidene chloride resins ; Polyvinyl alcohol resin, etc.

The aforesaid flexible sheet-like member may be composed of a single layer formed by a layer containing one or more than two kinds of the aforesaid polymer materials, or may be composed of two or more layers respectively containing one or more than two layers of the aforesaid polymer materials, and containing and The layer is composed of one or more layers of polymer materials.

The aforementioned flexible sheet member is preferably a peeling sheet that has been subjected to a release treatment on one side that contacts the adhesive layer. Release agents for release treatment, including silicone, fluorine, alkyd, unsaturated polyester, polyolefin and wax release agents.

The aforementioned adhesive sheet has a first flexible sheet member attached to one side of the aforementioned adhesive layer, and a second flexible sheet member attached to the other side of the aforementioned adhesive layer. The first flexible sheet-like member is a first release sheet, and the second flexible sheet-like member is a second release sheet. The method of surface contact with the adhesive layer is preferred. When the adhesive layer is clamped by two release sheets, it is preferable that one release sheet is a heavy release type release sheet with high peel strength, and the other release sheet is a light release type release sheet with low peel strength.

(Manufacture of Adhesive Sheet) The method of manufacturing an adhesive sheet, for example, can be formed by applying the above-mentioned adhesive composition to a flexible sheet-shaped member, and if necessary, drying and heating it to harden it to form an adhesive layer. manufacture.

Coating of the adhesive composition may be, for example, reverse gravure coating, direct gravure coating, die coating, rod coating, wire bar coating, roll coating, spin coating, Various coating methods such as dip coating, spray coating, knife coating and kiss coating; inkjet method; offset printing, screen printing, flexographic printing and other printing methods. In addition, corona treatment, plasma treatment, hot air treatment, ozone treatment, ultraviolet treatment and other surface treatments can also be performed on the surface of the release sheet before coating the adhesive composition.

The drying and heating step is not particularly limited, as long as the solvent used in the adhesive composition can be removed and hardened, but it is preferably carried out at a temperature of 60° C. to 150° C. for about 20 seconds to 300 seconds. Wherein heating temperature is preferably preferably with 100 ℃～130 ℃ especially.

When disposing the first flexible sheet-like member on one side of the adhesive layer and the second flexible sheet-like member on the other side, the adhesive composition can be coated on the first flexible sheet-like member first, After the adhesive layer is formed on the first flexible sheet member, the second flexible sheet member is attached to the adhesive layer. In addition, the adhesive layer can be cured as required, and the curing condition can be, for example, about 3 to 7 days at 60° C.

[Flexible laminated member] The flexible laminated member of the present invention has a first flexible member, a second flexible member, and a Adhesive layers bonded to each other, the adhesive layer is characterized in that it is formed of the aforementioned adhesive material. Since the adhesive layer of the flexible laminated member is formed of the above-mentioned adhesive material, even if the flexible laminated member is repeatedly bent, it is possible to suppress the appearance defect of a wavy shape at the bent portion.

Fig. 2 shows an example of the flexible laminated member of the present invention. The flexible laminated member 20 of Fig. 2 has a first flexible member 22, a second flexible member 24, and is located between the first flexible member 22 and the second flexible member 24, and fits the Adhesive layer 12 of flexible components.

The structure of the above-mentioned flexible laminated member includes, for example, a structure in which the first flexible member and the second flexible member are both flexible devices; and the second flexible member is a flexible For the device, the first flexible member is a structure of a functional sheet-like member attached to the bendable device. The aforementioned flexible device includes a foldable foldable display and a rollable display that can be rolled into a cylinder. The aforementioned functional sheet-like components include cover films, barrier films, polarizing films, retardation films, optical compensation films, brightness enhancement films, diffusion films, anti-reflection films, transparent conductive films, metal mesh films, buffer films, and the like.

The aforementioned first flexible component and the second flexible component are components that can be bent or bent repeatedly. The first flexible component and the second flexible component include flexible substrate materials, functional sheet components, display elements (organic EL modules, electronic paper modules, etc.) and the like. Wherein at least one of the first flexible member and the second flexible member is a display element is preferred. The aforementioned flexible laminated member can be used for a flexible display.

(Manufacturing method of flexible laminated member) The manufacturing method of the flexible laminated member of the present invention is not particularly limited, and includes, for example, the following methods (1) to (4).

(1) Peel off the release sheet attached to one side of the adhesive sheet, attach the exposed adhesive layer to the first flexible member, peel off the release sheet attached to the other side of the adhesive sheet, and attach the exposed adhesive layer to the first flexible member. 2. A method for laminating flexible components to obtain a flexible laminated component. (2) Apply the adhesive composition to one side of the first flexible member, and if required, dry and heat it to harden it to form an adhesive layer, and then attach the adhesive layer to the side of the release sheet that has release properties . Afterwards, the release sheet is peeled off, and the exposed adhesive layer is bonded to the second flexible member to obtain a flexible laminated member. (3) Apply the adhesive composition on one side of the first flexible member, and if necessary, dry and heat it to harden to form an adhesive layer, and then attach the adhesive layer to the second flexible member to Method for obtaining a flexible laminated structure. (4) Coating the adhesive composition on the side of the release sheet with release properties, and drying and heating it to harden it to form an adhesive layer, and attaching the adhesive layer to the first flexible member. Afterwards, the release sheet is peeled off, and the exposed adhesive layer is bonded to the second flexible member to obtain a flexible laminated member.

In any case of the above (1) to (4), the order of use of the first flexible member and the second flexible member can be exchanged. The formation of the adhesive layer can use the same various coating methods and various printing methods as in the manufacture of adhesive sheets. The drying and hardening steps are also the same, and it can also be cured if necessary. In addition, when manufacturing a flexible laminate, the release sheet used may be the same as that used for the adhesive sheet. [Example]

Hereinafter, the present invention will be described in more detail based on specific examples. The present invention is not limited to the following examples, and can be implemented after appropriately changing without changing the gist. In addition, the polymerization rate of the polymer composition, the weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of the polymer components, the thickness of the adhesive layer and the measurement of the adhesive material were all carried out according to the following methods.

The meanings of the abbreviations are as follows. EHA: 2-Ethylhexyl Acrylate LA: Lauryl Acrylate AA: Acrylic Acid HBA: 4-Hydroxybutyl Acrylate BTEE: Ethyl = 2-Methyl-2-n-Butyl Tellurium Hydrogen-Propionate AIBN: Azo Diisobutyronitrile AcOEt: ethyl acetate

(Polymerization rate) ¹ H-NMR (solvent: CDCl ₃ , internal standard: TMS) was measured using a nuclear magnetic resonance (NMR) measuring device (manufactured by Bruker Biospin, model: AVANCE500 (frequency 500 MHz)), and the resulting NMR was obtained The integral ratio of the signal from the monomer to the signal from the polymer in the spectrum is used to calculate the polymerization rate of the monomer.

(Weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn)) Gel permeation chromatography (GPC) was carried out using a high performance liquid chromatography (manufactured by Tosoh Corporation, model HLC-8320GPC), wherein the chromatographic tube Two pieces of TSKgel Super HZM-H (manufactured by Tosoh Corporation) were used as a column, a tetrahydrofuran solution was used as a mobile phase, and a differential refractometer was used as a detector. The determination conditions were column temperature 40°C, sample concentration 0.5 mg/mL, injection volume 10 μm, flow rate 0.6 mL/min, and polystyrene (molecular weight 9,840,000, 5,480,000, 2,890,000, 1,090,000, 775,000, 427,000, 190,000, 96,400 , 37,900, 10,200, 2,630, 440) as a standard substance to establish a calibration curve (calibration curve). Using GPC software (manufactured by Tosoh Corporation, Ecosec Peak Separation (Version 1.04)), the waveform separation of the measured chromatogram with a retention time of 6 to 11 minutes was performed by Gaussian approximation, and the weight average molecular weight (Mw ), molecular weight distribution (Mw/Mn) and content. Waveform separation parameters are set as Threshold: 0.5, Smooth Width: 8, start dwell time: 6, end dwell time: 11.

(Thickness of Adhesive Layer) The thickness of the adhesive layer was obtained by measuring the total thickness of the entire adhesive sheet with a thickness measuring machine (manufactured by Tester Sangyo Co., Ltd., "TH-104"), and subtracting the thickness of the release sheet from the total thickness.

(Gel fraction) Cut a wire mesh (400 mesh) with a width of 50 mm and a length of 120 mm and measure its mass W2, and take 80 mg to 120 mg of an adhesive layer (adhesive material) from the adhesive sheet and measure its mass W1. In order to prevent the adhesive material from falling off, it was wrapped with wire mesh and made into a test piece. Put the test piece into a glass bottle, pour 40g of ethyl acetate into it, shake it gently, and then let it stand at room temperature (25°C) for more than 72 hours. After standing still, take out the test piece from the glass bottle, place it at room temperature for more than 12 hours, and then dry it in a vacuum oven at 100°C for 4 hours. After cooling the dried sample to room temperature, its mass W3 was measured, and the gel fraction was calculated from the following formula. Gel fraction (mass%)=(W3-W2)/W1 x 100

(Stress relaxation time under 400% strain and recovery rate after 400% strain) Adhesive layers (adhesive materials) constituting the adhesive sheet are laminated by hand-push rollers to make a laminate with a thickness of 600 μm and use it as Specimen. The measurement system used a viscoelasticity measuring device (manufactured by Anton Paar, MCR302), clamped the sample with a parallel plate with a diameter of 8 mm (the joint surface was roughened with No. 240 sandpaper), and carried out in an atmosphere of 25°C. During the measurement, compress the specimen with an axial force of 1N and maintain the compressed state for 10 minutes, then change the axial force to 0.05N, and immediately apply shear stress to deform the specimen to a strain of 400%. Next, the strain was maintained at 400% for 10 minutes, the change in shear stress was measured, and the stress relaxation time was measured. Thereafter, the shear stress (0 kPa) was released and allowed to stand for 10 minutes, and the final strain after 10 minutes was measured to obtain the recovery rate. The stress relaxation time is set as the time for the shear stress to reach 0.368 times the initial stress after the strain reaches 400%. The initial stress was set to a shear stress value 0.1 second after the start of shear stress application. The recovery rate is calculated by the following formula: Recovery rate (%)={(400-final strain)/400}x100

(Strain under 20kPa stress and recovery rate after 20kPa stress is applied) Adhesive layers (adhesive materials) constituting the adhesive sheet are laminated by hand-push rollers to make a laminate with a thickness of 600μm and use it as a test piece. The measurement system used a viscoelasticity measuring device (manufactured by Anton Paar, MCR302), clamped the sample with a parallel plate with a diameter of 8 mm (the joint surface was roughened with No. 240 sandpaper), and carried out in an atmosphere of 25°C. During the measurement, compress the specimen with an axial force of 1N and maintain the compressed state for 10 minutes, then change the axial force to 0.05N, apply a shear stress of 20kPa and perform a creep test for 10 minutes, and measure the strain after 10 minutes ( 20kPa strain). Then release the shear stress (0kPa) and leave it for 10 minutes, measure the final strain after 10 minutes to obtain the recovery rate. Those who were too soft to measure were evaluated as "×". Deform the test piece to a strain of 400%. Next, the strain was maintained at 400% for 10 minutes, the change in shear stress was measured, and the stress relaxation time was measured. Thereafter, the shear stress (0 kPa) was released and allowed to stand for 10 minutes, and the final strain after 10 minutes was measured to obtain the recovery rate. The recovery rate is calculated by the following formula: Recovery rate (%)={(20kPa strain-final strain)/20kPa strain}x100

(Repeated tensile test) The adhesive layer (adhesive material) constituting the adhesive sheet is laminated by sticking the adhesive layer (adhesive material) of the adhesive sheet to each other with a push roller to form a laminate with a thickness of 600 μm. The laminate is cut into a size of 10 mm wide and 70 mm long and manufactured Specimen. The test was carried out using a precision universal testing machine (manufactured by Shimadzu Corporation, AUTOGRAPH®AGX) in an environment of 23°C and 50%, the distance between the clamping tools was set to 30mm, and the tensile speed was set to 30mm/min. In the test, the specimen is stretched from the state of tensile stress 0kPa until the tensile stress reaches 50kPa, and then shrinks until the tensile stress returns to 0kPa. This expansion and contraction was repeated 12 times, and the presence or absence of breakage of the test piece was confirmed. Those without breakage were evaluated as "O", and those with breakage were rated as "X".

(Measurement of Adhesive Force) The release sheet on one side of the adhesive sheet is peeled off from the adhesive layer, and the adhesive layer is exposed to the corona of polyethylene terephthalate (PET) film (Toyoboester® film E5100: manufactured by Toyobo, thickness 50 μm) Laminate the treated surface, cut out a size of 25mm in width and 100mm in length, and make an adhesive sheet with base material. Using the method of JIS Z 0237 (2009), measure the adhesive force of the adhesive sheet with the base material to the adherend such as polyimide film or glass. Specifically, after peeling off the release sheet from the adhesive layer, roll it back and forth twice with a 2 kg roller, and place a polyimide film (Kapton®100V: manufactured by Toray DuPont, thickness 25 μm) or white board glass (S9112, Matsunami Glass Co., Ltd. Industrial Co., Ltd., thickness 1.0~1.2mm) Press and fit the surface of the adhesive layer. Next, the adhesive force of the adhesive layer was measured under the conditions of a peeling speed of 300mm/min and a peeling angle of 180° using a precision universal testing machine "AUTOGRAPH®AGS-1kNX, 50N force gauge" manufactured by Shimadzu Corporation.

<Manufacture of Polymer Composition> (Synthesis Example 1: Polymer Composition X _a ) In a flask equipped with an argon introduction tube and a stirrer, EHA (340.2 g), LA (240.0 g), AA (18.0 g), After replacing HBA (1.8g), AIBN (26.1mg), and AcOEt (353.4g) with argon, BTEE (105.0mg) was added and reacted at 60°C for 24 hours to polymerize. After the reaction was completed, AcOEt was added to the reaction solution to obtain a solution containing the polymer composition X _a . The solid content of the solution was 26.2% by mass.

(Synthesis Example 2: Polymer Composition X _b ) The same procedure as in Synthesis Example 1 was carried out to obtain a solution containing Polymer Composition X _b . The monomers, organotellurium compounds, azo polymerization initiators, solvents, reaction conditions and polymerization rates used are shown in Table 1.

(Synthesis Example 3: Polymerization Composition Y _a ) EHA (1,334.0 g), LA (600.0 g), AA (60.0 g), HBA (6.0 g), AcOEt ( 1,333.3g) and replaced with argon, the temperature was raised to 82°C, AIBN (875.8mg) dissolved in AcOEt (45g) was added dropwise over 2 hours, and then reacted for 4 hours to polymerize. After the reaction was completed, AcOEt was added to the reaction solution to obtain _a solution containing the polymer composition Ya. The solid content of the solution was 39.5% by mass.

(Synthesis Example 4: Polymer Composition Y _b ) The same procedure as Synthesis Example 3 was carried out to obtain a solution containing the polymer composition Y _b . The monomers, organotellurium compounds, azo polymerization initiators, solvents, reaction conditions and polymerization rates used are shown in Table 1.

The polymerization conditions etc. of each polymer composition are shown in Table 1, wherein, the content of each structural unit in the polymer composition, the amount of functional groups in 1g of the polymer composition and the glass transition temperature are obtained from the monomers used in the polymerization reaction. The input rate and the polymerization speed were obtained.

【Table 1】

(Polymer Components in Polymer Compositions X _a and X _b ) When gel permeation chromatography and waveform separation were performed on Polymer Composition X _{a, only the polymer component X a 1} could be confirmed, while Polymer Composition X _b In the case of gel permeation chromatography and waveform separation, only the polymer component X _b 1 can be confirmed. Table 2 shows the physical properties of the polymer components X _a 1 and X _b 1 .

【Table 2】

(Polymer Components in Polymer Compositions _Ya and _Yb ) When polymer composition _Ya was subjected to gel permeation chromatography and waveform separation, polymer components _Ya 1, _Ya 2, and _Ya 3 could be confirmed. When gel permeation chromatography and waveform separation are performed on the polymer composition _Yb , polymer components _Yb1 , _Yb2 , and _Yb3 can be confirmed. Table 3 shows the physical properties of the polymer components Y _a 1 to Y _a 3 and Y _b 1 to Y _b 3.

【table 3】

<Manufacture of Adhesive Composition> (Adhesive Composition No. 1) 0.154 parts by mass of crosslinking agent _A ( Duranate®MHG-80B) and butyl acetate, stirred to obtain adhesive composition No.1 with a solid content of 20% by mass. In adhesive composition No.1, the first reactive group contained in the polymer components X _a 1, Y _a 1, _Ya 2, and Y _a 3 is a hydroxyl group, and the second reactive group contained in the crosslinking agent A The group is an isocyanate group.

(Adhesive Composition No.2~11) Except that the formula was changed as shown in Tables 4 and 5, the other parts were the same as Adhesive Composition No.1 to produce Adhesive Composition No.2~11. The blending amount of the crosslinking agent A shown in Table 4 and 5 is the blending amount converted in terms of solid content, and the solid content refers to components other than the solvent. In the adhesive composition No.2~8, the first reactive group contained in the polymer components X _a 1, Y _a 1, Ya 2 and Y _a 3 is _a hydroxyl group, and the second reactive group contained in the crosslinking agent A The reactive groups are isocyanate groups. In adhesive compositions No.9~11, the first reactive group contained in polymer components X _b 1, Y _b 1, Y _b 2, and Y _b 3 is a carboxyl group, and the second reactive group contained in crosslinking agent B The reactive group is an epoxy group.

＜Preparation of Adhesive Sheet＞ Coat the adhesive composition on the release liner of the first release sheet (PET film with release treatment on the surface, Clean Sepa®HY-US20: manufactured by Higashiyama Film, thickness 75μm) using a Baker coater On the surface, after drying to a film thickness of about 50 μm, dry at 60° C. for 3 minutes with a constant temperature dryer, and then dry at 150° C. for 3 minutes. Next, attach the release surface of the second release sheet (PET film with release treatment on the surface, Clean Sepa®HY-S10: made by Dongshan Film, thickness 38 μm) to the adhesive layer formed on the first release sheet, and then Aging treatment at 60°C for 3 days to form an adhesive layer sandwiched between two release sheets. Table 4 shows the evaluation results of the adhesive layer (adhesive material) formed from each adhesive composition.

[Table 4]

交聯劑A：Duranate®MHG-80B（旭化成製，異氰酸酯系交聯劑(六亞甲基二異氰酸酯的異氰脲酸酯體，官能基數為6，固體成分濃度為80質量%，NCO量為15.1質量%)）　　交聯劑B：TETRAD®-C（三菱瓦斯化學製，1,3-雙(N, N-二縮水甘油氨甲基)環己烷，官能基數為4，固體成分濃度為100質量%，環氧基量為9.8mmol/g）　　塑化劑：Claprene®LIR-410（液態異戊二烯類橡膠，重量平均分子量為30000） [table 5]

Cross-linking agent A: Duranate® MHG-80B (manufactured by Asahi Kasei, isocyanate-based cross-linking agent (isocyanurate body of hexamethylene diisocyanate, functional group number: 6, solid content concentration: 80% by mass, NCO content: 15.1% by mass)) Crosslinking agent B: TETRAD®-C (manufactured by Mitsubishi Gas Chemical Co., Ltd., 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 4 functional groups, solid content concentration of 100% by mass, the amount of epoxy group is 9.8mmol/g) Plasticizer: Claprene®LIR-410 (liquid isoprene rubber, weight average molecular weight: 30000)

Adhesive composition No. 1 is a case where the adhesive composition contains (A) (meth)acrylic copolymer component but does not contain (B) (meth)acrylic copolymer component. The adhesive material formed by the adhesive composition No. 1 has a small strain when a shear stress of 20 kPa is applied, poor flexibility, and poor adhesion to glass.

Adhesive compositions No. 2 and 3 are adhesive compositions containing (A) (meth)acrylic copolymer components and (B) (meth)acrylic copolymer components, and among all polymer components (A) When the content of the (meth)acrylic copolymer component is 75% by mass to 99% by mass. The adhesive materials formed by these adhesive compositions No2 and 3 have good recovery rate after straining to 400%, strain amount when 20kPa shear stress is applied, and index in repeated tensile test. In addition, its adhesion to either glass or PI film is good.

Adhesive compositions No. 4~8 are adhesive compositions containing (A) (meth)acrylic copolymer components and (B) (meth)acrylic copolymer components, but the total polymer components (A) When the content of the (meth)acrylic copolymer component is less than 75% by mass. Among them, the recovery rate of the adhesive materials formed by the adhesive compositions No. 4~6 after straining to 400% is relatively poor. In addition, the adhesive materials formed by adhesive compositions No. 7 and No. 8 were broken during repeated tensile tests.

Adhesive compositions No. 9~11 are adhesive compositions containing (A) (meth)acrylic copolymer components and (B) (meth)acrylic copolymer components, and among all polymer components (A) When the content of the (meth)acrylic copolymer component is 75% by mass to 99% by mass. The recovery rate of the adhesive materials formed by these adhesive compositions No.9~11 after straining to 400%, the strain amount when a shear stress of 20kPa is applied, and the index in the repeated tensile test are all good. In addition, its adhesion to either glass or PI film is good.

The present invention includes the following aspects.

(Aspect 1) An adhesive composition for a flexible display, which is used to bond one of the flexible members constituting the flexible display to other flexible members, which contains a plurality of (meth)acrylic copolymers ingredients and crosslinkers. The (meth)acrylic copolymer component includes at least (A) (meth)acrylic copolymer component and (B) (meth)acrylic copolymer component. The (A) (meth)acrylic copolymer component has a first reactive group, and the molecular weight distribution (Mw/Mn) is 3.0 or less; the (B) (meth)acrylic copolymer component has a first reactive group , the molecular weight distribution (Mw/Mn) is greater than 3.0; the crosslinking agent has a second reactive group that reacts with the first reactive group; in the plurality of (meth)acrylic copolymer components, the (A) The content of the (meth)acrylic copolymer component is 75% by mass to 99% by mass.

(Aspect 2) The adhesive composition for flexible displays according to Aspect 1, wherein the (A) (meth)acrylic copolymer component and the (B) (meth)acrylic copolymer The weight average molecular weight of the ingredients is 100,000 to 3 million.

(Aspect 3) The adhesive composition for flexible displays according to Aspect 1 or Aspect 2, wherein the (A) (meth)acrylic copolymer component has a weight average molecular weight of 100,000 or more.

(Aspect 4) An adhesive composition for a flexible display according to any one of aspects 1 to 3, wherein the weight average molecular weight of the (B) (meth)acrylic copolymer component is 80 Below 10,000.

(Aspect 5) The adhesive composition for a flexible display according to any one of aspects 1 to 4, wherein the crosslinking agent is an isocyanate crosslinking agent and/or an epoxy crosslinking agent.

(Aspect 6) The adhesive composition for flexible displays according to Aspect 5, wherein the isocyanate crosslinking agent is selected from the group consisting of aliphatic diisocyanate compounds, aliphatic diisocyanate compounds, and aliphatic diols. At least one selected from the group consisting of an adduct of a compound, an adduct of an aliphatic diisocyanate compound, a biuret form of an aliphatic diisocyanate compound, and an isocyanurate form of an aliphatic diisocyanate compound.

(Aspect 7) The adhesive composition for flexible displays according to Aspect 5, wherein the aforementioned epoxy crosslinking agent is selected from the group consisting of aliphatic epoxy compounds, alicyclic epoxy compounds, aromatic At least one of the group consisting of epoxy compounds and heterocyclic epoxy compounds.

(Aspect 8) The adhesive composition for a flexible display according to any one of aspects 1 to 7, wherein the first reactive group is a hydroxyl group and/or a carboxyl group.

(Aspect 9) An adhesive material for a flexible display, which is used to bond one of the flexible components constituting the flexible display with other flexible components to form a flexible display, wherein the adhesive material is The hardened product of the adhesive composition described in any one of samples 1 to 8.

(Aspect 10) The adhesive material for a flexible display according to Aspect 9, wherein the cured product has a gel fraction of 50% by mass or more.

(pattern 11) An adhesive sheet for a flexible display, comprising an adhesive layer for laminating one flexible member constituting the flexible display with other flexible members, and a flexible adhesive sheet attached to at least one side of the adhesive layer. sheet-like components. Wherein, the adhesive layer is formed by the adhesive material described in aspect 9 or aspect 10.

(Aspect 12) An adhesive sheet for a flexible display according to Aspect 11, comprising a first flexible sheet member attached to one side of the aforementioned adhesive layer, and a first flexible sheet member attached to the other side of the adhesive layer The second flexible sheet member, the first flexible sheet member is a first release sheet, the second flexible sheet member is a second release sheet, the first release sheet and the second release sheet Lay them in such a way that their respective release surfaces touch the adhesive layer.

(Aspect 13) A flexible laminated member comprising a first flexible member, a second flexible member, and an adhesive layer for attaching the first flexible member and the second flexible member to each other , the adhesive layer is formed of the adhesive material described in aspect 9 or 10.

(Aspect 14) The flexible laminated member according to Aspect 13, wherein at least one of the first flexible member and the second flexible member is a display element.

(Aspect 15) A flexible display having the flexible laminated member according to Aspect 13 or 14.

(pattern 16) A (meth)acrylic copolymer mixture used in an adhesive composition for flexible displays, It comprises at least (A) (meth)acrylic copolymer component and (B) (meth)acrylic copolymer component, the (A) (meth)acrylic copolymer component contains a first reactive group, molecular weight The distribution (Mw/Mn) is 3.0 or less; the (B) (meth)acrylic copolymer component contains a first reactive group, and the molecular weight distribution (Mw/Mn) is greater than 3.0. The first reactive group is a hydroxyl group and/or a carboxyl group; the content of the (A) (meth)acrylic copolymer component in the (meth)acrylic copolymer mixture is 75% by mass to 99% by mass.

10: adhesive sheet 12: adhesive layer 14: first flexible sheet member 16: second flexible sheet member 20: flexible laminated member 22: first flexible member 24: second flexible member

Fig. 1 is a schematic cross-sectional view of an embodiment of the adhesive sheet of the present invention. Fig. 2 is a schematic cross-sectional view of an embodiment of the flexible laminated member of the present invention.

none

Claims (16)

An adhesive composition for a flexible display, used for laminating one flexible member constituting a flexible display with other flexible members, the adhesive composition comprising: Plural (meth)acrylic copolymer components; and cross-linking agent; among them, The (meth)acrylic copolymer component includes at least (A) (meth)acrylic copolymer component and (B) (meth)acrylic copolymer component; wherein, The (A) (meth)acrylic copolymer component has a first reactive group, and the molecular weight distribution (Mw/Mn) is 3.0 or less; The (B) (meth)acrylic copolymer component has a first reactive group, and the molecular weight distribution (Mw/Mn) is greater than 3.0; The crosslinking agent includes a second reactive group that reacts with the aforementioned first reactive group; Among the plurality of (meth)acrylic copolymer components, the content rate of the (A) (meth)acrylic copolymer component is 75% by mass to 99% by mass. The adhesive composition for flexible displays according to Claim 1, wherein the weight average molecular weight of the (A) (meth)acrylic copolymer component and (B) (meth)acrylic copolymer component is 10 Ten thousand to three million. The adhesive composition for flexible displays according to claim 1 or 2, wherein the (A) (meth)acrylic copolymer component has a weight average molecular weight of 100,000 or more. The adhesive composition for flexible displays according to any one of claims 1 to 3, wherein the (B) (meth)acrylic copolymer component has a weight average molecular weight of 800,000 or less. The adhesive composition for flexible displays according to any one of Claims 1 to 4, wherein the crosslinking agent is an isocyanate crosslinking agent and/or an epoxy crosslinking agent. The adhesive composition for flexible displays according to claim 5, wherein the isocyanate crosslinking agent is selected from aliphatic diisocyanate compounds, adducts of aliphatic diisocyanate compounds and aliphatic diol compounds At least one selected from the group consisting of adducts of aliphatic diisocyanate compounds, biuret forms of aliphatic diisocyanate compounds, and isocyanurate forms of aliphatic diisocyanate compounds. The adhesive composition for flexible displays according to claim 5, wherein the epoxy crosslinking agent is selected from aliphatic epoxy compounds, alicyclic epoxy compounds, aromatic epoxy compounds, and At least one of the group consisting of heterocyclic epoxy compounds. The adhesive composition for flexible displays according to any one of claims 1 to 7, wherein the first reactive group is a hydroxyl group and/or a carboxyl group. An adhesive material for a flexible display, used for laminating one of the flexible components constituting the flexible display with other flexible components, the adhesive material is the adhesive composition described in any one of Claims 1-8 Hardening of things. The adhesive material for flexible displays according to Claim 9, wherein the cured product has a gel fraction of 50% by mass or more. An adhesive sheet for a flexible display, comprising: An adhesive layer for laminating one flexible member constituting a flexible display with other flexible members; and a flexible sheet member attached to at least one side of the adhesive layer; wherein the adhesive layer It is formed by the adhesive material as described in Claim 9 or 10. The adhesive sheet for flexible displays as described in Claim 11, comprising a first flexible sheet member attached to one side of the aforementioned adhesive layer, and a second flexible sheet member attached to the other side of the adhesive layer components; among them, The first flexible sheet member is a first release sheet, and the second flexible sheet member is a second release sheet; The first release sheet and the second release sheet are bonded in such a way that their respective release surfaces contact the adhesive layer. A flexible laminated component, comprising: a first flexible member; the second flexible member; and an adhesive layer for attaching the first flexible member and the second flexible member to each other; wherein, The adhesive layer is formed of the adhesive material as described in claim 9 or 10. The flexible laminated member according to claim 13, wherein at least one of the first flexible member and the second flexible member is a display element. A flexible display, comprising the flexible laminated member according to claim 13 or 14. A (meth)acrylic copolymer mixture used in an adhesive composition for flexible displays, comprising at least (A) a (meth)acrylic copolymer component and (B) a (meth)acrylic copolymer component ;in, The (A) (meth)acrylic copolymer component has a first reactive group, and the molecular weight distribution (Mw/Mn) is 3.0 or less; The (B) (meth)acrylic copolymer component has a first reactive group, and the molecular weight distribution (Mw/Mn) is greater than 3.0; wherein, The first reactive group is hydroxyl and/or carboxyl; In the (meth)acrylic copolymer mixture, the content of the (A) (meth)acrylic copolymer component is 75% by mass to 99% by mass.

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