JP7187959B2 - Curing agents, undercoating agents and films - Google Patents

Description

The present disclosure relates to curing agents, undercoat agents and films.

As a manufacturing method for decorating the surface of plastic products with patterns and textures and adding scratch resistance (hard coat properties), plastic films such as PET (polyethylene terephthalate) are laminated with an adhesive layer, a pattern layer, and a hard coat layer. An in-mold injection molding method is used in which the decorated film is inserted into a mold and adhered to the molded product at the same time as the injection molding.

The in-mold injection molding method is classified into the injection molding simultaneous transfer decoration method and the injection molding simultaneous laminate decoration method, depending on the difference in the configuration of the decorative film that is attached to the resin molded product.

In the injection molding simultaneous transfer decoration method, a release layer is formed on one side of the base film, and a transfer layer (layer laminated in order of hard coat layer, pattern layer, adhesive layer, etc.) is laminated on the release layer. Insert the decorative film for transfer into the mold, place the base film side in close contact with the inner surface of the mold, close the mold, and inject molten thermoplastic resin into the mold from the transfer layer side. After filling, when the mold is opened and the molded product is taken out, the release layer and the hard coat layer are peeled off, thereby transferring the transfer layer to the outermost surface to obtain the molded product.

In many cases, an active energy ray-curable resin is used as the material used for the hard coat layer (Patent Document 1).

Japanese Patent Application Laid-Open No. 2008-006708

A problem when the hard coat layer is an active energy ray-curable hard coat layer is poor adhesion between the active energy ray-curable hard coat layer and the pattern layer. Therefore, an undercoat layer that imparts adhesion is provided between the active energy ray-curable hard coat layer and the pattern layer.

Here, when an undercoat layer is provided, that is, when an undercoat agent is used, it is required that not only adhesion but also reprintability and resistance to moist heat be good. Therefore, the problem to be solved by the present invention is to provide a curing agent capable of producing a film having good initial adhesion, light resistance adhesion, overprinting property, and moist heat resistance.

As a result of intensive studies, the present inventors have found that the above problems can be solved by a specific curing agent.

The following items are provided by this disclosure.
(Item 1)
A curing agent comprising a modified polyisocyanate adduct which is a reaction product of a group of compounds including a polyisocyanate adduct, water and a hydroxyl group-containing compound and has an isocyanate group content of 13% by mass or less based on 100% by mass of solids.
(Item 2)
The curing agent according to the above items, wherein the polyisocyanate adduct is a reaction product of hydrogenated xylylene diisocyanate and trimethylolpropane.
(Item 3)
An undercoat agent comprising the curing agent according to any one of the above items.
(Item 4)
4. An undercoating agent according to Item 3, comprising a urethane (meth)acrylic copolymer which is a reaction product of a hydroxyl group-containing (meth)acrylic copolymer and a polyisocyanate.
(Item 5)
A film in which a cured undercoat agent layer containing the cured undercoat agent according to any one of the above items is laminated on at least one side of the film.

In the present disclosure, one or more of the features described above may be provided in further combinations in addition to the explicit combinations.

By using the curing agent of the present invention, it is possible to obtain a film excellent in overprinting property, initial adhesion, wet heat resistance and light resistance adhesion.

Throughout the present disclosure, the range of numerical values for each physical property value, content, etc. can be set as appropriate (for example, by selecting from the upper and lower limit values described in each item below). Specifically, for the numerical value α, when the upper limit of the numerical value α is A1, A2, A3, etc., and the lower limit of the numerical value α is B1, B2, B3, etc., the range of the numerical value α is A1 or less, A2 or less, A3 or less, B1 or more, B2 or more, B3 or more, A1-B1, A1-B2, A1-B3, A2-B1, A2-B2, A2-B3, A3-B1, A3-B2, A3-B3 etc. are exemplified.

[Curing agent]
The present disclosure includes a modified polyisocyanate adduct, which is a reaction product of a group of compounds including a polyisocyanate adduct, water, and a hydroxyl group-containing compound, and has an isocyanate group content of 13% by mass or less based on 100% by mass of solids. offer.

<Polyisocyanate adduct>
Polyisocyanate adducts are exemplified by reaction products of polyisocyanates and polyols.

(polyisocyanate)
In the present disclosure, a "polyisocyanate" is a compound with two or more isocyanate groups (-N=C=O). Polyisocyanate may be used alone or in combination of two or more.

Examples of polyisocyanates include aliphatic polyisocyanates, aromatic polyisocyanates, and alicyclic polyisocyanates.

Examples of aliphatic polyisocyanates include linear aliphatic polyisocyanates and branched aliphatic polyisocyanates.

A linear alkylene group etc. are illustrated as a linear aliphatic group. A linear alkylene group can be represented by the general formula —(CH ₂ ) _n — (n is an integer of 1 or more), and includes a methylene group, an ethylene group, a propylene group, an n-butylene group, an n-pentylene group, and an n-hexylene group. , n-heptylene group, n-octylene group, n-nonylene group, n-decamethylene group and the like.

Linear aliphatic polyisocyanates include methylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, and the like. be.

A branched alkylene group etc. are illustrated as a branched aliphatic group. A branched alkylene group is a group in which at least one hydrogen of a linear alkylene group is substituted with an alkyl group, and specific examples include a diethylpentylene group, a trimethylbutylene group, a trimethylpentylene group, a trimethylhexylene group ( trimethylhexamethylene group) and the like.

Branched aliphatic polyisocyanates are exemplified by diethylpentylene diisocyanate, trimethylbutylene diisocyanate, trimethylpentylene diisocyanate, trimethylhexamethylene diisocyanate and the like.

The alicyclic group is exemplified by a single ring alicyclic group, a bridged ring alicyclic group, a condensed ring alicyclic group and the like. A cycloalkylene group may also have one or more hydrogens replaced by a straight or branched alkyl group.

In the present disclosure, monocyclic means a cyclic structure with no internal bridging structure formed by covalent carbon bonds. Fused rings also refer to cyclic structures in which two or more single rings share two atoms (ie, each ring shares (condenses) only one edge with each other). Bridged ring means a cyclic structure in which two or more single rings share three or more atoms.

The monocyclic alicyclic group is exemplified by cyclopentylene group, cyclohexylene group, cycloheptylene group, cyclodecylene group, 3,5,5-trimethylcyclohexylene group and the like.

The bridging ring alicyclic group is exemplified by a tricyclodecylene group, an adamantylene group, a norbornylene group and the like.

The condensed ring alicyclic group is exemplified by a bicyclodecylene group and the like.

The alicyclic polyisocyanate is exemplified by monocyclic alicyclic polyisocyanate, crosslinked alicyclic polyisocyanate, condensed alicyclic polyisocyanate and the like.

Monocyclic alicyclic polyisocyanates include hydrogenated xylylene diisocyanate, isophorone diisocyanate, cyclopentylene diisocyanate, cyclohexylene diisocyanate, cycloheptylene diisocyanate, cyclodecylene diisocyanate, 3,5,5-trimethylcyclohexylene diisocyanate, dicyclohexyl Methane diisocyanate and the like are exemplified.

Examples of the crosslinked cycloaliphatic polyisocyanate include tricyclodecylene diisocyanate, adamantane diisocyanate, and norbornene diisocyanate.

The condensed ring alicyclic polyisocyanate is exemplified by bicyclodecylylene diisocyanate and the like.

The number of carbon atoms in the aliphatic group is not particularly limited, but its upper limit is exemplified by 30, 29, 25, 20, 15, 12, 10, 9, 8, 7, 6, 5, 4, 3, 2, etc. , the lower limit is 29, 25, 20, 15, 12, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, and the like. In one embodiment, the aliphatic group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, still more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms.

A phenylene group, a naphthylene group, etc. are illustrated as an aromatic group.

The aromatic polyisocyanate is exemplified by xylene diisocyanate and the like.

The upper limit of the content of structural units derived from polyisocyanate in 100% by mass of the polyisocyanate adduct is exemplified by 85, 80, 75, 70, 65% by mass, etc., and the lower limit is 80, 75, 70, 65, 60% by mass. % etc. are exemplified. In one embodiment, the content of structural units derived from polyisocyanate in 100% by mass of the polyisocyanate adduct is preferably 60 to 85% by mass.

The upper limit of the content of structural units derived from polyisocyanate in 100 mol% of the polyisocyanate adduct is exemplified by 75, 74, 73, 72, 71 mol%, and the lower limit is 74, 73, 72, 71, 70 mol. % etc. are exemplified. In one embodiment, the content of structural units derived from polyisocyanate in 100 mol % of the polyisocyanate adduct is preferably 70 to 75 mol %.

(Polyol) Examples of the polyol include (poly)pentaerythritol, (poly)trimethylolpropane, (poly)glycerin, sorbitol, and sugar.

（式中、ｍは０以上の整数である。）
により示される化合物である。 ((poly)pentaerythritol)
(Poly)pentaerythritol has the structural formula (1)

(In the formula, m is an integer of 0 or more.)
It is a compound represented by

Examples of (poly)pentaerythritol include pentaerythritol, dipentaerythritol, tripentaerythritol, and tetrapentaerythritol.

（式中、ｐは０以上の整数である。）
により示される化合物である。 ((poly)trimethylolpropane)
(Poly)trimethylolpropane has the structural formula (2)

(In the formula, p is an integer of 0 or more.)
It is a compound represented by

Examples of (poly)trimethylolpropane include trimethylolpropane and ditrimethylolpropane.

The upper limit of the content of the polyol-derived structural unit in 100% by mass of the polyisocyanate adduct is exemplified by 40, 35, 30, 25, 20% by mass, and the lower limit is 35, 30, 25, 20, 15% by mass. etc. are exemplified. In one embodiment, the content of polyol-derived structural units in 100% by mass of the polyisocyanate adduct is preferably 15 to 40% by mass.

The upper limit of the content of the polyol-derived structural unit in 100 mol% of the polyisocyanate adduct is exemplified by 30, 29, 28, 27, 26 mol%, and the lower limit is 29, 28, 27, 26, 25 mol%. etc. are exemplified. In one embodiment, the content of polyol-derived structural units in 100 mol % of the polyisocyanate adduct is preferably 25 to 30 mol %.

The upper limit of the mass ratio of the polyisocyanate-derived structural unit and the polyol-derived structural unit in the polyisocyanate adduct is 6, 5.5, 5, 4.5, 4, 3.5, 3, 2.5, 2. etc., and the lower limit is exemplified by 5.5, 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, and the like. In one embodiment, the mass ratio of the polyisocyanate-derived structural unit and the polyol-derived structural unit in the polyisocyanate adduct is preferably 1.5-6.

The upper limit of the molar ratio of the polyisocyanate-derived structural unit and the polyol-derived structural unit in the polyisocyanate adduct is exemplified by 3, 2.9, 2.7, 2.5, 2.3, 2.1, and the like. , the lower limit is exemplified by 2.9, 2.7, 2.5, 2.3, 2.1, 2, and the like. In one embodiment, the molar ratio of the polyisocyanate-derived structural units and the polyol-derived structural units in the polyisocyanate adduct is preferably 2-3.

In one embodiment, the polyisocyanate adduct is the reaction product of hydrogenated xylylene diisocyanate and trimethylolpropane.

［式中、Ｒ^１Ａ～Ｒ^１Ｅは、それぞれ独立に脂肪族基又は芳香族基であり、Ｒ^Ａ～Ｒ^Ｂは、それぞれ独立にイソシアネート基又は、

（Ｒ^ａ～Ｒ^ｂは、各構成単位ごとにそれぞれ独立に脂肪族基又は芳香族基であり、Ｒはイソシアネート基又はＲ^Ａ基自身であり、ｎは１以上の整数である。）
であり、
Ｒ^１Ｄ、Ｒ^１Ｅ、Ｒ^Ｂは、各構成単位ごとに基が異なっていてもよい。ｎ１は０以上の整数である。ｎ１は０～２が好ましい。］
で示されるトリメチロールプロパンとポリイソシアネートとの反応物等が例示される。 Polyisocyanate adducts are
Structural formula below:

[In the formula, R ^1A to R ^1E are each independently an aliphatic group or an aromatic group, and R ^A to R ^B are each independently an isocyanate group or

(R ^a to R ^b are each independently an aliphatic group or an aromatic group for each structural unit, R is an isocyanate group or an R ^A group itself, and n is an integer of 1 or more.)
and
R ^1D , R ^1E , and R ^B may have different groups for each structural unit. n1 is an integer of 0 or more. n1 is preferably 0-2. ]
A reaction product of trimethylolpropane and polyisocyanate represented by is exemplified.

Examples of commercially available polyisocyanate adducts include Duranate P301-75E (manufactured by Asahi Kasei Corp.) and Takenate D120N (manufactured by Mitsui Chemicals, Inc.).

The upper limit of the weight average molecular weight (Mw) of the polyisocyanate adduct is 3000, 2900, 2500, 2000, 1900, 1500, 1000, 900, etc., and the lower limit is 2900, 2500, 2000, 1900, 1500, 1000, 900. , 800 and the like are exemplified. In one embodiment, the polyisocyanate adduct preferably has a weight average molecular weight (Mw) of 800-3000.

The upper limit of the number average molecular weight (Mn) of the polyisocyanate adduct is 2500, 2400, 2000, 1900, 1500, 1000, 900, etc., and the lower limit is 2400, 2000, 1900, 1500, 1000, 900, 800, etc. exemplified. In one embodiment, the polyisocyanate adduct preferably has a number average molecular weight (Mn) of 700-2500.

The upper limit of the molecular weight distribution (Mw/Mn) of the polyisocyanate adduct is exemplified by 5, 4, 3, 2 and the like, and the lower limit is exemplified by 4, 3, 2, 1 and the like. In one embodiment, the molecular weight distribution (Mw/Mn) of the polyisocyanate adduct is preferably 1-5.

The weight average molecular weight (Mw) and number average molecular weight (Mn) can be obtained as polystyrene equivalent values measured by gel permeation chromatography (GPC) (same below).

The upper limit of the ratio of the polyisocyanate adduct in 100% by mass of the compound group is exemplified by 95, 94, 93, 92, 91% by mass, and the lower limit is 94, 93, 92, 91, 90% by mass, etc. be done. In one embodiment, the proportion of the polyisocyanate adduct in 100% by mass of the compound group is preferably 90 to 95% by mass.

The upper limit of the ratio of the polyisocyanate adduct in 100 mol% of the above compound group is exemplified by 70, 65, 60, 55 mol%, and the lower limit is exemplified by 65, 60, 55, 50 mol%. In one embodiment, the proportion of the polyisocyanate adduct in 100 mol % of the compound group is preferably 50 to 70 mol %.

<Hydroxyl group-containing compound>
Examples of hydroxyl group-containing compounds include alcohols and hydroxyl group-containing alkyl (meth)acrylates.

Alcohols are exemplified by monoalcohols, polyols and the like.

Examples of polyols include those mentioned above.

Examples of hydroxyl group-containing alkyl (meth)acrylates include those described below.

The upper limit of the hydroxyl value of the hydroxyl group-containing compound is exemplified by 1260, 1200, 1000, 900, 750, 500, 400 mgKOH/g, and the lower limit is 1200, 1000, 900, 750, 500, 400, 380 mgKOH/g. exemplified. In one embodiment, the hydroxyl value of the hydroxyl group-containing compound is preferably 380-1260 mgKOH/g.

In the present disclosure, the hydroxyl value is the following formula (hydroxyl value) = (potassium hydroxide molecular weight: 56.1) × 1000 / (hydroxyl equivalent)
(hydroxyl equivalent) = (molecular weight of one molecule) / (number of hydroxyl groups present in one molecule)
It is a calculated value by

The upper limit of the ratio of the hydroxyl group-containing compound in 100% by mass of the compound group is exemplified by 10, 9, 7, 5, 4, 2% by mass, etc., and the lower limit is 9, 7, 5, 4, 2, 1% by mass. % etc. are exemplified. In one embodiment, the proportion of the hydroxyl group-containing compound in 100% by mass of the compound group is preferably 1 to 10% by mass.

The upper limit of the ratio of the hydroxyl group-containing compound in 100 mol% of the above compound group is exemplified by 40, 35, 30, 25, 20, 15, 10 mol%, etc., and the lower limit is 35, 30, 25, 20, 15, Examples include 10 and 5 mol %. In one embodiment, the proportion of the hydroxyl group-containing compound in 100 mol % of the compound group is preferably 5 to 40 mol %.

The upper limit of the ratio of water in 100% by mass of the above compound group is exemplified by 1, 0.9, 0.7, 0.5, 0.3% by mass, etc., and the lower limit is 0.9, 0.7, 0.5, 0.3, 0.2% by mass and the like are exemplified. In one embodiment, the proportion of water in 100% by mass of the compound group is preferably 0.2 to 1% by mass.

The upper limit of the proportion of water in 100 mol % of the compound group is exemplified by 30, 25, 20, 15 mol %, and the lower limit is exemplified by 25, 20, 15, 10 mol %. In one embodiment, the proportion of water in 100 mol % of the compound group is preferably 10 to 30 mol %.

<Compounds that are not polyisocyanate adducts, water, or hydroxyl group-containing compounds: Also referred to as other compounds>
The group of compounds may include compounds that are neither polyisocyanate adducts, water, or hydroxyl group-containing compounds.

Other compounds are exemplified by monoisocyanate, polyisocyanate nurate, polyisocyanate biuret, polyisocyanate allophanate and the like.

In one embodiment, the ratio of other compounds to 100% by mass of the compound group is less than 5 parts by mass, less than 1 part by mass, less than 0.1 parts by mass, less than 0.01 parts by mass, 0 parts by mass, etc. be done.

In one embodiment, the ratio of other compounds to 100 mol% of the compound group is less than 5 mol%, less than 1 mol%, less than 0.1 mol%, less than 0.01 mol%, 0 mol%, etc. be done.

<Modified polyisocyanate adduct>
Examples of the upper limit of the isocyanate group content of the modified polyisocyanate adduct at a solid content of 100% by mass include 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, and 1% by mass. , the lower limit is 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0% by mass, and the like. In one embodiment, the isocyanate group content of the modified polyisocyanate adduct with a solid content of 100% by mass is preferably 13% by mass or less.

The isocyanate group content of the modified polyisocyanate adduct can be measured, for example, by the following method using a potentiometric automatic titrator (manufactured by Kyoto Electronics Industry Co., Ltd.).
1) Take 0.5 g of sample in a 200 mL Erlenmeyer flask.
2) Add 20 mL of dehydrated toluene to dissolve the sample.
3) Add 10.0 mL of 0.2 mol/L di-n-butylamine solution.
4) Shake to mix evenly, then leave for at least 20 minutes.
5) Add 100 mL of isopropyl alcohol.
6) Titrate with 0.1 mol/L hydrochloric acid solution.
7) Carry out a blank test in the same manner, and calculate the isocyanate group content using the following formula.
Isocyanate group content = (SIZE / ((BL1-EP1) × FA1)) × K2
EP1: titration volume (mL)
BL1: blank value FA1: titrant factor (1.00)
K2: Coefficient (1000)
SIZE: Sample collection amount (g)
Note that the isocyanate group content at a solid content of 100% is twice the value of the isocyanate group content at a solid content of 50%.

Among the isocyanate groups possessed by the polyisocyanate adduct, the upper limit of the ratio of groups that react with water and/or hydroxyl group-containing compounds is exemplified by 30, 29, 27, 25, 23, 21, 20, 19, 17 mol%, and the like. The lower limit is exemplified by 29, 27, 25, 23, 21, 20, 19, 17, 15 mol%. In one embodiment, the proportion of groups reacting with water and/or hydroxyl group-containing compounds among the isocyanate groups of the polyisocyanate adduct is preferably 15 mol % or more, more preferably 20 to 30 mol %.

The upper limit of the weight average molecular weight (Mw) of the polyisocyanate adduct is exemplified by 6000, 5000, 4000, 3000, 2000, 1500, 1300, etc., and the lower limit is 5000, 4000, 3000, 2000, 1500, 1300, 1200, etc. exemplified. In one embodiment, the polyisocyanate adduct preferably has a weight average molecular weight (Mw) of 1200-6000.

The upper limit of the number average molecular weight (Mn) of the polyisocyanate adduct is exemplified by 5000, 4000, 3000, 2000, 1500 and the like, and the lower limit is exemplified by 4000, 3000, 2000, 1500, 1000 and the like. In one embodiment, the number average molecular weight (Mn) of the polyisocyanate adduct is preferably 1000-5000.

The upper limit of the molecular weight distribution (Mw/Mn) of the polyisocyanate adduct is exemplified by 6, 5, 4, 3, 2 and the like, and the lower limit is exemplified by 5, 4, 3, 2, 1 and the like. In one embodiment, the molecular weight distribution (Mw/Mn) of the polyisocyanate adduct is preferably 1-6.

The method for producing the modified polyisocyanate adduct may employ a known method. Polyisocyanate, water, a hydroxyl group-containing compound, and optionally other compounds are mixed in a solvent-free or appropriate solvent (toluene, etc.). The reaction may be carried out at an appropriate reaction temperature (60 to 90° C., etc.) in the presence of an appropriate catalyst (tin octoate, etc.).

<Additive>
The curing agent may contain agents other than the modified polyisocyanate adduct as additives. Examples of additives include polymerization inhibitors, antioxidants, light stabilizers, antifoaming agents, surface conditioners, pigments, antistatic agents, metal oxide fine particle dispersions, organic fine particle dispersions, and the like. In one embodiment, the content of the additive is about 0.1 to 10% by mass, less than about 10 parts by mass, less than about 5 parts by mass, less than 1 part by mass, less than 0.1 parts by mass of the curing agent. about less than 0.01 parts by mass, about 0 parts by mass, and the like.

The curing agent can be used as a curing agent for an undercoat agent, a curing agent for a transfer foil, a curing agent for an in-mold injection molding method transfer foil, and the like.

[Undercoat agent]
The present disclosure provides an undercoat agent containing the curing agent described above.

In one embodiment, the undercoating agent contains a urethane (meth)acrylic copolymer that is a reaction product of a hydroxyl group-containing (meth)acrylic copolymer and a polyisocyanate.

<Hydroxyl group-containing (meth)acrylic copolymer>
The hydroxyl group-containing (meth)acrylic copolymer is exemplified by a copolymer containing a structural unit derived from a hydroxyl-free alkyl (meth)acrylate and a structural unit derived from a hydroxyl group-containing alkyl (meth)acrylate. Single or multiple hydroxyl group-containing (meth)acrylic copolymers may be used when producing the urethane (meth)acrylic copolymer.

（式中、Ｒ^ａ１は水素原子、又はメチル基であり、Ｒ^ａ２はアルキル基である。）
で表わされる。水酸基非含有アルキル（メタ）アクリレートは、単独又は２種以上で使用され得る。 (Hydroxyl group-free alkyl (meth) acrylate)
The hydroxyl-free alkyl (meth)acrylate is

(In the formula, R ^a1 is a hydrogen atom or a methyl group, and R ^a2 is an alkyl group.)
is represented by A hydroxyl group-free alkyl (meth)acrylate may be used alone or in combination of two or more.

Alkyl groups are exemplified by linear alkyl groups, branched alkyl groups, cycloalkyl groups and the like.

A straight-chain alkyl group is represented by a general formula of -C _n H _2n+1 (n is an integer of 1 or more). Linear alkyl groups include methyl group, ethyl group, propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decamethyl group, etc. are exemplified.

A branched alkyl group is a group in which at least one hydrogen of a straight-chain alkyl group has been replaced by an alkyl group. Branched alkyl groups are exemplified by diethylpentyl, trimethylbutyl, trimethylpentyl, trimethylhexyl and the like.

The cycloalkyl group is exemplified by a monocyclic cycloalkyl group, a bridged ring cycloalkyl group, a condensed ring cycloalkyl group and the like.

Monocyclic cycloalkyl groups are exemplified by cyclopentyl, cyclohexyl, cycloheptyl, cyclodecyl and 3,5,5-trimethylcyclohexyl groups.

The bridging ring cycloalkyl group is exemplified by a tricyclodecyl group, an adamantyl group, a norbornyl group and the like.

The condensed ring cycloalkyl group is exemplified by a bicyclodecyl group and the like.

Examples of hydroxyl-free alkyl (meth)acrylates include hydroxyl-free linear alkyl (meth)acrylates, hydroxyl-free branched alkyl (meth)acrylates, and hydroxyl-free cycloalkyl (meth)acrylates.

Linear alkyl (meth)acrylates not containing hydroxyl groups include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, and hexyl (meth)acrylate. , heptyl (meth)acrylate, octyl (meth)acrylate, hexadecyl (meth)acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, icosyl (meth)acrylate, docosyl (meth)acrylate, etc. are exemplified.

Hydroxyl group-free branched alkyl (meth)acrylates include isopropyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, and 2-(meth)acrylate. Ethylhexyl and the like are exemplified.

Examples of hydroxyl-free cycloalkyl (meth)acrylates include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cyclopentanyl (meth)acrylate, and isobornyl (meth)acrylate.

Among these, alkyl (meth)acrylates having an alkyl group with about 1 to 20 carbon atoms are preferred because they contribute to leveling and adhesion in the undercoat agent. In addition, by using hydroxyl-free alkyl (meth)acrylates having different numbers of carbon atoms in the alkyl group, physical properties such as the glass transition temperature of the hydroxyl group-containing (meth)acrylic copolymer can be adjusted.

The upper limit of the content of structural units derived from hydroxyl-free alkyl (meth)acrylate in 100 mol% of the total structural units of the hydroxyl-containing (meth)acrylic copolymer is 98, 95, 90, 85, 80, 75, 70, 65. Examples include mol % and the like, and the lower limit is exemplified by 95, 90, 85, 80, 75, 70, 65, 62 mol % and the like. In one embodiment, the content of structural units derived from hydroxyl-free alkyl (meth)acrylate in 100 mol% of the total structural units of the hydroxyl-containing (meth)acrylic copolymer is preferably about 62 to 98 mol%.

The upper limit of the content of structural units derived from hydroxyl-free alkyl (meth)acrylates in 100% by mass of the total structural units of the hydroxyl-containing (meth)acrylic copolymer is 98, 95, 90, 85, 80, 75, 70% by mass. etc., and the lower limit is exemplified by 95, 90, 85, 80, 75, 70, 65% by mass. In one embodiment, the content of structural units derived from hydroxyl-free alkyl (meth)acrylate in 100% by mass of the total structural units of the hydroxyl-containing (meth)acrylic copolymer is preferably about 65 to 98% by mass.

（式中、Ｒ^ａ３は水素原子、又はメチル基であり、Ｒ^ａ４は直鎖アルキレン基、分岐アルキレン基、又はシクロアルキレン基である。）
で表わされる。水酸基含有アルキル（メタ）アクリレートは、２種以上を併用してもよい。 (hydroxy group-containing alkyl (meth) acrylate)
The hydroxyl group-containing alkyl (meth)acrylate has the following structural formula

(In the formula, R ^a3 is a hydrogen atom or a methyl group, and R ^a4 is a linear alkylene group, a branched alkylene group, or a cycloalkylene group.)
is represented by Two or more kinds of hydroxyl group-containing alkyl (meth)acrylates may be used in combination.

Examples of hydroxyl-containing alkyl (meth)acrylates include hydroxyl-containing linear alkyl (meth)acrylates, hydroxyl-containing branched alkyl (meth)acrylates, and hydroxyl-containing cycloalkyl (meth)acrylates.

Examples of hydroxyl group-containing linear alkyl (meth)acrylates include hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

Examples of hydroxyl group-containing branched alkyl (meth)acrylates include 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 3-hydroxybutyl (meth)acrylate.

Examples of hydroxyl group-containing cycloalkyl (meth)acrylates include hydroxycyclohexyl (meth)acrylate and 4-(hydroxymethyl)cyclohexylmethyl (meth)acrylate.

The hydroxyl group-containing alkyl (meth)acrylate preferably has a hydroxyalkyl group with about 1 to 4 carbon atoms from the viewpoint of the pot life of the undercoat agent.

The upper limit of the content of the structural unit derived from the hydroxyl group-containing alkyl (meth)acrylate in 100 mol% of the total structural units of the hydroxyl group-containing (meth)acrylic copolymer is 20, 18, 15, 10, 5, 2.5 mol%, etc. are exemplified, and the lower limits are exemplified by 18, 15, 10, 5, 2.5, 1.5 mol % and the like. In one embodiment, the content of the structural unit derived from the hydroxyl group-containing alkyl (meth)acrylate in 100 mol % of the total structural units of the hydroxyl group-containing (meth)acrylic copolymer is preferably in the range of about 1.5 to 20 mol %.

The upper limit of the content of the structural unit derived from the hydroxyl group-containing alkyl (meth)acrylate in 100% by mass of the total structural units of the hydroxyl group-containing (meth)acrylic copolymer is exemplified by 15, 14, 10, 5, 2.5% by mass, etc. The lower limit is exemplified by 13, 10, 5, 2.5, 2% by mass, and the like. In one embodiment, the content of the structural unit derived from the hydroxyl group-containing alkyl (meth)acrylate in 100% by weight of the total structural units of the hydroxyl group-containing (meth)acrylic copolymer is preferably in the range of about 2 to 15% by weight.

Substance amount ratio of structural units derived from hydroxyl-free alkyl (meth)acrylate and hydroxyl-containing alkyl (meth)acrylate-derived structural units in hydroxyl-containing (meth)acrylic copolymer (hydroxyl-free alkyl (meth)acrylate _mol / hydroxyl group The upper limit of the content alkyl (meth)acrylate _mol ) is exemplified by 65, 60, 50, 40, 30, 20, 10, 6, etc., and the lower limit is 60, 55, 50, 40, 30, 20, 10, 5 .5 and the like are exemplified. In one embodiment, the substance amount ratio of the structural unit derived from the hydroxyl-free alkyl (meth)acrylate and the structural unit derived from the hydroxyl-containing alkyl (meth)acrylate in the hydroxyl-containing (meth)acrylic copolymer (the hydroxyl-free alkyl ( The meth)acrylate _mol /hydroxyl group-containing alkyl (meth)acrylate _mol ) is preferably about 5.5 to 65.

Mass ratio of structural units derived from hydroxyl-free alkyl (meth)acrylate and hydroxyl-containing alkyl (meth)acrylate-derived structural units in the hydroxyl-containing (meth)acrylic copolymer (hydroxyl-free alkyl (meth)acrylate _mass / hydroxyl-containing The upper limit of alkyl (meth)acrylate _mass ) is exemplified by 50, 45, 40, 30, 20, 10, 7, etc., and the lower limit is exemplified by 48, 45, 40, 30, 20, 10, 6, etc. . In one embodiment, the mass ratio of structural units derived from hydroxyl-free alkyl (meth)acrylate to hydroxyl-containing alkyl (meth)acrylate-derived structural units in the hydroxyl-containing (meth)acrylic copolymer (hydroxyl-free alkyl (meth) ) acrylate _mass /hydroxy group-containing alkyl (meth)acrylate _mass ) is preferably about 6 to 50.

(Monomers other than hydroxyl-free alkyl (meth)acrylates and hydroxyl-containing alkyl (meth)acrylates: also referred to as other monomers)
When producing a hydroxyl group-containing (meth)acrylic copolymer, a monomer that does not fall under any of hydroxyl group-containing alkyl (meth)acrylates and hydroxyl group-containing alkyl (meth)acrylates may be used. Other monomers may be used in combination of two or more.

Other monomers include (meth)acrylic acid, α,β-unsaturated carboxylic acids, epoxy group-containing (meth)acrylates, styrenes, α-olefins, unsaturated alcohols, aryl (meth)acrylates, dialkylaminoalkyl (meth) ) acrylates and their salts, dialkylaminoalkyl (meth)acrylamides and their salts, chain transfer monomers, (meth)acrylonitrile, (meth)acrylamides, vinylamines, monofunctional monomers other than the above, bis(meth)acrylamide , di(meth)acrylic esters, divinyl esters, bifunctional monomers other than the above, trifunctional monomers, tetrafunctional monomers, and the like.

The upper limit of the content of other monomer-derived structural units in 100 mol% of the total structural units of the hydroxyl group-containing (meth)acrylic copolymer is exemplified by 20, 15, 10, 9, 5, 4, 1 mol%, etc. The lower limit is exemplified by 18, 15, 10, 9, 5, 4, 1 and 0 mol%. In one embodiment, the content range of structural units derived from other monomers in 100 mol % of all structural units of the hydroxyl group-containing (meth)acrylic copolymer is preferably about 0 to 20 mol %.

The upper limit of the content of structural units derived from other monomers in 100% by mass of the total structural units of the hydroxyl group-containing (meth)acrylic copolymer is exemplified by 20, 15, 10, 9, 5, 4, 1% by mass, etc. The lower limit is exemplified by 18, 15, 10, 5, 4, 1, 0% by mass, and the like. In one embodiment, the content range of structural units derived from other monomers in 100% by mass of all structural units of the hydroxyl group-containing (meth)acrylic copolymer is preferably about 0 to 20% by mass.

Amount ratio of structural units derived from hydroxyl-free alkyl (meth)acrylate and structural units derived from other monomers in hydroxyl-containing (meth)acrylic copolymer ( _mol of other monomer/ _mol of hydroxyl-free alkyl (meth)acrylate) The upper limit of is exemplified by 0.30, 0.25, 0.20, 0.15, 0.10, 0.05, etc., and the lower limit is 0.25, 0.20, 0.15, 0.10 , 0.05, 0, etc. are exemplified. In one embodiment, the substance amount ratio of structural units derived from hydroxyl-free alkyl (meth)acrylate and structural units derived from other monomers in the hydroxyl-containing (meth)acrylic copolymer (other monomer _mol / hydroxyl-free alkyl (Meth)acrylate _mol ) is preferably about 0 to 0.30.

Mass ratio of structural units derived from hydroxyl-free alkyl (meth)acrylates and structural units derived from other monomers in the hydroxyl-containing (meth)acrylic copolymer (other monomer _mass / hydroxyl-free alkyl (meth)acrylate _mass ) The upper limit is exemplified by 0.30, 0.25, 0.20, 0.15, 0.10, 0.05, etc., and the lower limit is 0.25, 0.20, 0.15, 0.10, 0.05, 0, etc. are exemplified. In one embodiment, the mass ratio of structural units derived from hydroxyl-free alkyl (meth)acrylate and structural units derived from other monomers in the hydroxyl-containing (meth)acrylic copolymer (other monomer _mass / hydroxyl-free alkyl ( Meth)acrylate _mass ) is preferably about 0 to 0.30.

Upper limit of the substance amount ratio of the structural unit derived from the hydroxyl group-containing alkyl (meth)acrylate and the structural unit derived from the other monomer in the hydroxyl group-containing (meth)acrylic copolymer (other monomer _mol /hydroxyl group-containing alkyl (meth)acrylate _mol ) is 15.0, 10.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, 1.0, 0.5, 0.1, etc. are exemplified, and the lower limits are 13.0, 10.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, 1.0, 0.5 , 0.1, 0, etc. are exemplified. In one embodiment, the substance amount ratio of the structural unit derived from the hydroxyl group-containing alkyl (meth)acrylate and the structural unit derived from the other monomer in the hydroxyl group-containing (meth)acrylic copolymer (other monomer _mol / hydroxyl group-containing alkyl (meth) ) acrylate _mol ) is preferably about 0 to 15.0.

The upper limit of the mass ratio of structural units derived from hydroxyl group-containing alkyl (meth)acrylates and structural units derived from other monomers in the hydroxyl group-containing (meth)acrylic copolymer (other monomer _mass / hydroxyl group-containing alkyl (meth)acrylate _mass ) is , 10.0, 8.0, 5.0, 4.0, 3.0, 2.0, 1.0, 0.5, 0.1, etc., and the lower limits are 8.0, 5. Examples include 0, 4.0, 3.0, 2.0, 1.0, 0.5, 0, and the like. In one embodiment, the mass ratio of structural units derived from hydroxyl group-containing alkyl (meth) acrylate and structural units derived from other monomers in the hydroxyl group-containing (meth) acrylic copolymer (other monomer _mass / hydroxyl group-containing alkyl (meth) Acrylate _mass ) is preferably about 0 to 10.0.

<Physical properties of hydroxyl group-containing (meth)acrylic copolymer>
The upper limit of the glass transition temperature of the hydroxyl group-containing (meth) acrylic copolymer is exemplified by 100, 90, 80, 70, 60, 50, 40, 35 ° C., and the lower limit is 95, 90, 80, 70, 60, 50. , 40, 35, 30, 20° C., and the like. In one embodiment, the hydroxyl group-containing (meth)acrylic copolymer preferably has a glass transition temperature of about 20 to 100°C, more preferably about 30 to 80°C.

The glass transition temperature is measured using a commercially available measuring instrument (for example, product name "DSC8230B" manufactured by Rigaku Denki Co., Ltd.).

The upper limit of the hydroxyl group equivalent weight of the hydroxyl group-containing (meth)acrylic copolymer is exemplified by 1.1, 1.0, 0.5, 0.25, 0.20, 0.17, 0.15, 0.10 meq/g. The lower limit is exemplified by 1.0, 0.5, 0.25, 0.20, 0.17, 0.15, 0.10, 0.09 meq/g. In one embodiment, the hydroxyl group equivalent of the hydroxyl group-containing (meth)acrylic copolymer is preferably about 0.09 to 1.1 meq/g, more preferably about 0.17 to 1.1 meq/g, and 0.25 to 0.25 meq/g. About 9 meq/g is more preferable.

In the present disclosure, the hydroxyl equivalent is the physical amount of hydroxyl groups present in 1 g of solid.

The upper limit of the hydroxyl value (in terms of solid content) of the hydroxyl group-containing (meth)acrylic copolymer is exemplified by 60, 50, 40, 30, 20, 15 mgKOH/g, etc., and the lower limit is 50, 40, 30, 20, 15, 10 mgKOH/g etc. are illustrated. In one embodiment, the hydroxyl group-containing (meth)acrylic copolymer preferably has a hydroxyl value (in terms of solid content) of about 10 to 60 mgKOH/g.

The hydroxyl value is measured according to JIS K1557-1.

The upper limit of the acid value of the hydroxyl group-containing (meth)acrylic copolymer is exemplified by 0.4, 0.3, 0.2, 0.18, 0.1, 0.09, 0.05 meq/g, and the lower limit is , 0.35, 0.3, 0.2, 0.18, 0.1, 0.09, 0.05, 0.04 meq/g. In one embodiment, the acid value of the hydroxyl group-containing (meth)acrylic copolymer is preferably about 0.04 to 0.4 meq/g, more preferably about 0.09 to 0.18 meq/g, especially considering curability. preferable.

The acid value is measured according to JIS K0070.

The upper limit of the weight average molecular weight (Mw) of the hydroxyl group-containing (meth)acrylic copolymer is exemplified by 100000, 90000, 80000, 70000, 60000, 50000, 40000, 30000, 20000, 10000, 5000, 4000, etc., and the lower limit is 90000. , 80000, 70000, 60000, 50000, 40000, 30000, 20000, 10000, 5000, 4000, 3000, and the like. In one embodiment, the weight average molecular weight (Mw) of the hydroxyl group-containing (meth)acrylic copolymer is preferably about 3000 to 100000 from the viewpoint of blocking resistance, initial adhesion, and wet heat resistance adhesion of the undercoat agent. About 10,000 to 80,000 is more preferable.

The upper limit of the number average molecular weight (Mn) of the hydroxyl group-containing (meth)acrylic copolymer is exemplified by 100000, 90000, 80000, 70000, 60000, 50000, 40000, 30000, 20000, 10000, 5000, 4000, etc., and the lower limit is 90000. , 80000, 70000, 60000, 50000, 40000, 30000, 20000, 10000, 5000, 4000, 3000, and the like. In one embodiment, the number average molecular weight (Mn) of the hydroxyl group-containing (meth)acrylic copolymer is preferably about 3,000 to 100,000 from the viewpoint of the blocking resistance, initial adhesion, and wet heat resistance adhesion of the undercoat agent. About 10,000 to 80,000 is more preferable.

The upper limit of the molecular weight distribution (Mw/Mn) of the hydroxyl group-containing (meth)acrylic copolymer is exemplified by 10, 7.5, 5, 2.5, 2, etc., and the lower limit is 9.5, 7.5, 5, 2.5, 2, 1.5 and the like are exemplified. In one embodiment, the molecular weight distribution (Mw/Mn) of the hydroxyl group-containing (meth)acrylic copolymer is preferably about 1.5-10.

A hydroxyl group-containing (meth)acrylic copolymer can be produced by various known methods. A method for producing a hydroxyl group-containing (meth)acrylic copolymer includes a hydroxyl-free alkyl (meth) acrylate and a hydroxyl group-containing alkyl (meth) acrylate, and optionally other monomers in the absence of solvent or in an organic solvent, usually A method of conducting a copolymerization reaction for about 1 to 10 hours at about 80 to 180° C. in the presence of a polymerization initiator is exemplified. Examples of the organic solvent and polymerization initiator used in producing the hydroxyl group-containing (meth)acrylic copolymer include those described below.

Examples of the polyisocyanate used in producing the urethane (meth)acrylic copolymer include those mentioned above.

<Urethane (meth)acrylic copolymer>
The upper limit of the content of the structural unit derived from the hydroxyl group-containing (meth)acrylic copolymer contained in the urethane (meth)acrylic copolymer is exemplified by 99.8, 99.5, 99.3, 99.1% by mass, etc., and the lower limit is is 99.5, 99.3, 99.1, 99.0% by mass, and the like. In one embodiment, the content of structural units derived from the hydroxyl group-containing (meth)acrylic copolymer contained in the urethane (meth)acrylic copolymer is preferably 99.0 to 99.8% by mass of the urethane (meth)acrylic copolymer.

The upper limit of the content of the polyisocyanate-derived structural unit contained in the urethane (meth)acrylic copolymer is exemplified by 1.0, 0.9, 0.7, 0.5, 0.3% by mass, and the lower limit is , 0.9, 0.7, 0.5, 0.3, 0.2% by mass, and the like. In one embodiment, the content of the polyisocyanate-derived structural unit contained in the urethane (meth)acrylic copolymer is preferably 0.2 to 1.0% by mass of the urethane (meth)acrylic copolymer.

The upper limit of the mass ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylic copolymer and the structural unit derived from the polyisocyanate contained in the urethane (meth)acrylic copolymer is 500, 450, 400, 350, 300, 250, 200, 150. , 100 and the like, and the lower limits are exemplified by 450, 400, 350, 300, 250, 200, 150, 100, 99 and the like. In one embodiment, the mass ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylic copolymer and the structural unit derived from the polyisocyanate contained in the urethane (meth)acrylic copolymer is preferably 99-500.

The upper limit of the ratio (NCO/OH) between the isocyanate group equivalent of the polyisocyanate and the hydroxyl group equivalent of the hydroxyl group-containing poly(meth)acrylic polymer when producing the urethane (meth)acrylic copolymer is 0.14, 0.12, 0. .10, 0.09, 0.07, 0.05, etc., and the lower limit is exemplified as 0.12, 0.10, 0.09, 0.07, 0.05, 0.03, etc. . In one embodiment, the ratio (NCO/OH) between the isocyanate group equivalent of the polyisocyanate and the hydroxyl group equivalent of the hydroxyl group-containing poly(meth)acrylic polymer when producing the urethane (meth)acrylic copolymer is 0.03 to 0. .14 is preferred.

The upper limit of the weight average molecular weight (Mw) of the urethane (meth)acrylic copolymer is exemplified by 200000, 190000, 175000, 150000, 125000, 100000, 90000, 75000, 50000, 25000, 15000, etc., and the lower limit is 190000, 175000, 150000, 125000, 100000, 90000, 75000, 50000, 25000, 15000, 10000 and the like are exemplified. In one embodiment, the urethane (meth)acrylic copolymer preferably has a weight average molecular weight (Mw) of 10,000 to 200,000.

The upper limit of the number average molecular weight (Mn) of the urethane (meth)acrylic copolymer is exemplified by 150000, 125000, 100000, 75000, 50000, 25000, 10000, 9000, 7500, 6000, etc., and the lower limit is 125000, 100000, 75000, 50000, 25000, 10000, 9000, 7500, 6000, 5000 and the like are exemplified. In one embodiment, the urethane (meth)acrylic copolymer preferably has a number average molecular weight (Mn) of 5,000 to 150,000.

The upper limit of the molecular weight distribution (Mw/Mn) of the urethane (meth)acrylic copolymer is exemplified by 10, 9, 7, 5, 3 and the like, and the lower limit is exemplified by 9, 7, 5, 3, 2 and the like. In one embodiment, the molecular weight distribution (Mw/Mn) of the urethane (meth)acrylic copolymer is preferably 2-10.

The urethane (meth)acrylic copolymer may be produced by a known method. The reaction may be carried out at an appropriate reaction temperature (60 to 90° C., etc.) in the presence of a suitable catalyst (tin octoate, etc.).

<Curing catalyst>
The undercoating agent may contain a curing catalyst. A curing catalyst may be contained singly or in combination of two or more.

Examples of curing catalysts include organometallic catalysts and organic amine catalysts.

Examples of organometallic catalysts include organic typical metal catalysts and organic transition metal catalysts.

Examples of organic typical metal catalysts include organic tin catalysts and organic bismuth catalysts.

Examples of organic tin catalysts include dibutyltin dilaurate and dioctyltin dilaurate.

The organic bismuth catalyst is exemplified by bismuth octylate.

Organic transition metal catalysts are exemplified by organic titanium catalysts, organic zirconium catalysts, organic iron catalysts, and the like.

Examples of organic titanium catalysts include titanium ethyl acetoacetate.

Examples of organic zirconium catalysts include zirconium tetraacetylacetonate and the like.

Organic iron catalysts are exemplified by iron acetylacetonate and the like.

Examples of organic amine catalysts include diazabicyclooctane, dimethylcyclohexylamine, tetramethylpropylenediamine, ethylmorpholine, dimethylethanolamine, triethylamine and triethylenediamine.

When the undercoating agent contains a curing catalyst, the upper limit of the content of the curing catalyst in the undercoating agent is 1, 0.9, 0.75, 0.5, 0.25, 0.1, 0.09. , 0.05, 0.02% by mass, etc., and the lower limits are 0.9, 0.75, 0.5, 0.25, 0.1, 0.09, 0.05, 0.02, 0.01% by mass and the like are exemplified. In one embodiment, when the undercoating agent contains a curing catalyst, the content of the curing catalyst in the undercoating agent is preferably about 0.01 to 1% by mass.

<Organic solvent>
The undercoating agent may contain an organic solvent. The organic solvent may be contained alone or in combination of two or more. Organic solvents include ketone solvents such as methyl ethyl ketone, acetylacetone, methyl isobutyl ketone and cyclohexanone; aromatic solvents such as toluene and xylene; alcohol solvents such as methanol, ethanol, n-propanol, isopropanol and butanol; Glycol ether solvents such as triethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether and propylene glycol monomethyl ether acetate; ester solvents such as ethyl acetate, butyl acetate, methyl cellosolve acetate and cellosolve acetate; Solvesso #100 and Solvesso #150 ( All are trade names, manufactured by Exxon), haloalkane solvents such as chloroform, amide solvents such as dimethylformamide, and the like. Two or more organic solvents may be used in combination.

When the undercoating agent contains an organic solvent, the upper limit of the content of the organic solvent in the undercoating agent is exemplified by 90, 80, 70, 60, 50, 40, 30, 20% by mass, etc., and the lower limit is 85, 80, 70, 60, 50, 40, 30, 20, 15% by mass and the like are exemplified. In one embodiment, when the undercoating agent contains an organic solvent, the content of the organic solvent in the undercoating agent is preferably about 15 to 90% by mass, more preferably about 50 to 90% by mass. The organic solvent contained in the undercoat agent may contain the organic solvent contained in the curing agent, the urethane (meth)acrylic copolymer, and the curing catalyst.

<Additive>
The undercoating agent may contain agents other than the curing agent, the urethane (meth)acrylic copolymer, the curing catalyst, and the organic solvent as additives. Examples of additives include polymerization inhibitors, antioxidants, light stabilizers, antifoaming agents, surface conditioners, pigments, antistatic agents, metal oxide fine particle dispersions, organic fine particle dispersions, and the like. In one embodiment, examples of the content of the additive include about 0.1 to 10% by mass of the undercoat agent, about less than 10 parts by mass, about less than 5 parts by mass, less than 1 part by mass, about 0.1 Less than about 0.01 part by mass, about 0 part by mass, etc. are exemplified.

The undercoating agent is obtained by a method including a step of mixing the curing agent and, if necessary, the urethane (meth)acrylic copolymer, curing catalyst, organic solvent and/or additives by various known means. be done.

The above undercoating agent can be used as an undercoating agent for transfer foil, an undercoating agent for in-mold injection molding method transfer foil, and the like.

[the film]
The present disclosure provides a film in which a cured undercoat agent layer containing the cured undercoat agent is laminated on at least one side of the film.

Various known substrates are employed as the substrate. Base materials are polycarbonate film, acrylic film (polymethyl methacrylate film, etc.), polystyrene film, polyester film, polyolefin film, epoxy resin film, melamine resin film, triacetyl cellulose film, ABS film, AS film, norbornene resin film, cyclic Examples include olefin films and polyvinyl alcohol films. The thickness of the substrate is also not particularly limited, but is preferably about 50 to 200 μm. Although the thickness of the undercoat layer is not particularly limited, it is preferably about 0.1 to 5 μm.

The above films are produced by various known methods. In one embodiment, the method for producing a film comprises a step of applying an undercoating agent to at least one surface of a substrate (coating step), and a step of thermally curing to form a cured product layer of the undercoating agent (thermosetting step). )including. In one embodiment, the film has a cured layer of an undercoat agent laminated on a cured layer of an active energy ray-curable resin. In that case, the step of applying the cured product layer of the undercoat agent to the active energy ray-curable resin (coating step), the step of drying as necessary (drying step), and irradiating the active energy ray It further includes a step of forming an energy ray-curable resin cured material layer (active energy ray curing step).

(Coating process)
Examples of the coating method include bar coater coating, wire bar coating, Meyer bar coating, air knife coating, gravure coating, reverse gravure coating, offset printing, flexographic printing, and screen printing.

The coating amount is not particularly limited. The amount of coating is preferably about 0.1 to 30 g/m ² , more preferably about 1 to 20 g/m ² in mass after drying.

(Thermal curing process)
The drying method is exemplified by drying using a circulation dryer or the like. Drying conditions are exemplified by standing at 120° C. for 60 seconds.

When manufacturing a film, aging treatment is performed after drying as needed. An example is aging treatment at 40° C. for 72 hours.

(Active energy ray curing process)
The active energy ray used for the active energy ray curing reaction is exemplified by ultraviolet rays, electron beams, and the like. Examples of the ultraviolet light source include a xenon lamp, a high-pressure mercury lamp, and an ultraviolet irradiation device having a metal halide lamp. Incidentally, the amount of light, the arrangement of the light source, the transport speed, etc. can be adjusted as necessary. When a high-pressure mercury lamp is used, it is preferable to carry out curing at a conveying speed of about 5 to 50 m/min for one lamp having a light quantity of about 80 to 160 W/cm. On the other hand, in the case of electron beams, curing is preferably carried out at a conveying speed of about 5 to 50 m/min using an electron beam accelerator having an acceleration voltage of about 10 to 300 kV.

Active energy ray-curable resins include (meth)acrylic esters, urethane (meth)acrylates, polyester (meth)acrylates, epoxy (meth)acrylates, polyacrylic (meth)acrylates, and other radical-curable resins (for example, Arakawa Chemical Co., Ltd. Kogyo Co., Ltd. "Beamset Series")), resins that cure epoxides, oxetanes, vinyl ethers, etc. with cations or anions, and resins that cure by en-thiol reaction between alkenes and thiols. These may be used in combination.

Hereinafter, the present invention will be described in detail through examples and comparative examples. However, the above description of preferred embodiments and the following examples are provided for illustrative purposes only and not for the purpose of limiting the invention. Accordingly, the scope of the present invention is not limited to the embodiments or examples specifically described herein, but only by the claims. Further, in each example and comparative example, numerical values such as parts and % are based on mass unless otherwise specified.

Example 1-1: Production of Curing Agent A polyisocyanate adduct (product name “Takenate D120N”: hydrogenated xylylene diisocyanate and 600.0 parts by mass of an addition reaction product of trimethylolpropane (hereinafter referred to as hydrogenated XDI adduct), 18.6 parts by mass of 2-hydroxyethyl acrylate (hereinafter referred to as HEA), 1.4 parts by mass of water, and 316 parts by mass of methyl ethyl ketone. 5 parts by mass were charged, and the urethane-urea reaction was carried out at 60°C for 2 hours. After cooling to room temperature, a modified polyisocyanate adduct (50% solid content, 5.6% isocyanate group content at 100% solid content) was obtained.

The isocyanate group content of the modified polyisocyanate adduct was measured by the following method using a potentiometric automatic titrator (manufactured by Kyoto Electronics Industry Co., Ltd.).
1) A 0.5 g sample was placed in a 200 mL Erlenmeyer flask.
2) 20 mL of dehydrated toluene was added to dissolve the sample.
3) 10.0 mL of 0.2 mol/L di-n-butylamine solution was added.
4) The mixture was shaken and mixed uniformly, and then left for 20 minutes or longer.
5) 100 mL of isopropyl alcohol was added.
6) Titration was performed using a 0.1 mol/L hydrochloric acid solution.
7) A blank test was performed in the same manner, and the isocyanate group content was calculated using the following formula.
Isocyanate group content = (SIZE / ((BL1-EP1) × FA1)) × K2
EP1: titration volume (mL)
BL1: blank value FA1: titrant factor (1.00)
K2: Coefficient (1000)
SIZE: Sample collection amount (g)

Examples 1-2 to 1-4, Comparative Examples 1-1 to 1-2
Examples 1-2 to 1-4 and Comparative Examples 1-1 to 1-2 were produced in the same manner as in Example 1-1, except that the component compositions were changed as shown in the table below.

ＴＭＰ：トリメチロールプロパン

TMP: trimethylolpropane

Production Example 1: Production of urethane (meth)acrylic copolymer 306.6 parts by mass of methyl methacrylate (hereinafter also referred to as MMA) was added to a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen inlet tube. , 84.0 parts by mass of n-butyl methacrylate (hereinafter also referred to as BMA), 29.4 parts by mass of 2-hydroxyethyl methacrylate (hereinafter also referred to as HEMA), and 630 parts by mass of methyl ethyl ketone were charged, and the reaction system was Set to 60°C. Then, 2.1 parts by mass of 2,2'-azobis(2,4-dimethylvaleronitrile) was added and the temperature was maintained at around 60°C for 8 hours. Next, 4.2 parts by mass of 2,2'-azobis(2,4-dimethylvaleronitrile) was charged, and the reaction system was kept at about the same temperature for another 4 hours. Next, 350 parts by mass of methyl ethyl ketone and 1.9 parts by mass of hydrogenated xylylene diisocyanate were added and the mixture was kept at about 75° C. for 3 hours. Thereafter, the reaction system was cooled to room temperature to obtain a solution of urethane (meth)acrylic copolymer (30% non-volatile content).

Example 2-1: Production of Undercoating Agent 41.7 parts of the urethane (meth)acrylic copolymer of Production Example 1, 40.0 parts of the curing agent of Example 1-1, and dioctyltin dilaurate as a curing catalyst (solid content 0.25 parts of DOTDL (concentration of 100% or less), 81.1 parts of methyl ethyl ketone (hereinafter referred to as MEK) and 1.8 parts of acetylacetone (hereinafter referred to as AcAc) as organic solvents were used. A coating agent having a solid concentration of 20% was prepared by thoroughly mixing the above components.

Examples 2-2 to 2-5, Comparative Examples 2-1 to 2-2
Examples 2-2 to 2-5 and Comparative Examples 2-1 to 2-2 were carried out in the same manner as in Example 2-1 except that the type and amount of curing agent were changed as shown in the table below.

(Production of active energy ray-curable resin)
3-(2H-1,2,3-benzotriazol-2-yl)-4-hydroxyphenethyl methacrylate was added to a four-necked flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet and addition funnel. 11 parts of lat, 49.8 parts of glycidyl methacrylate, 15 parts of methyl methacrylate, 3 parts of azobisisobutyronitrile, and 100 parts of butyl acetate were charged and stirred, and the temperature was raised to 100 ° C. under a nitrogen stream and reacted for 10 hours. . After that, 24.2 parts of acrylic acid, 0.1 part of 4-methoxyphenol, and 0.3 parts of triphenylphosphine as a reaction catalyst were charged and reacted at 100 ° C. for 8 hours to obtain an active energy ray-curable resin (non-volatile 50%) was obtained.

(Production of film for evaluation)
5 parts of a photopolymerization initiator 1-hydroxycyclohexylphenyl ketone (trade name “Irgacure 184” BASF, hereinafter referred to as Irg184) was added to the obtained active energy ray-curable resin to prepare a coating liquid. Next, on the release-treated polyethylene terephthalate film, an active energy ray-curable resin was applied so that the film thickness after drying was 5 to 6 μm, dried at 80° C. for 1 minute, and then dried at 25 mJ/ A UV precure was performed at cm ² . Next, the undercoating agents according to Examples 1 to 5 and Comparative Examples 1 to 3 were coated on the active energy ray-curable resin cured material layer so that the film thickness after drying was 1 μm, and the temperature was 80° C.×5. Seconds of drying were performed. Next, an undercoat layer for vapor deposition was coated on the cured product layer of the undercoat agent so that the film thickness after drying was 1 μm, and dried at 120° C. for 1 minute. Using the coated film obtained up to this step, the reprintability was evaluated. As the vapor deposition undercoat layer, "Aracoat DA105/Aracoat CL102H" manufactured by Arakawa Chemical was used.
Then, the coated film was subjected to aluminum vapor deposition (thickness: 50 nm) using a commercially available vapor deposition apparatus (product name: "VPC-1100", manufactured by ULVAC KIKO, Inc.). Further, an adhesive was applied on the aluminum deposition layer so that the film thickness was 1 μm, and dried at 80° C. for 10 seconds.

(Manufacture of panel for evaluation)
The resulting film was thermally transferred to a commercially available acrylic plate, subjected to UV after-curing at 300 mj/cm ² , and then used as a test panel. Test panels were prepared in the same manner for the undercoating agents of other examples and comparative examples.

(Overprinting property)
The appearance immediately after coating the vapor deposition undercoat layer was visually evaluated. Evaluation criteria are as follows.
5 . . . Defective appearance is not observed even after overprinting.
4 . . . Slight coating streaks are partially observed.
3 . . . Coating streaks are observed on the entire surface.
2 . . . Coating streaks are observed on the entire surface, and irregularities are also partially observed.
1 . . . Coating streaks are observed on the entire surface, and unevenness is also observed.

(Initial adhesion)
Using the test panel obtained by the above method, a cellophane tape checkerboard peeling test was carried out.

(Damp heat resistance)
After 85%×72 hours at 85° C., UV adhesion was evaluated by cellophane tape cross-cut peeling test.

(light resistance adhesion)
After 168 hours at an illuminance of 50 mW/cm ² with an accelerated light resistance tester (super UV tester), evaluation was made by cellophane tape cross-cut peeling test.

Evaluation criteria for initial adhesion, wet heat resistance, and light resistance adhesion are as follows.
5 No peeling is observed.
4: Peeling of less than 5% is observed between the active energy ray-curable resin layer and the anchor layer.
3: Peeling of 5% or more to less than 20% is observed between the active energy ray-curable resin layer and the anchor layer.
2: Peeling of 20% or more to less than 50% is observed between the active energy ray-curable resin layer and the anchor layer.
1: 50% to 100% peeling was observed between the active energy ray-curable resin layer and the anchor layer.

Claims (5)

A reaction product of a compound group containing 50 to 80 mol% of a polyisocyanate adduct, 10 to 30 mol% of water, and 5 to 40 mol% of a hydroxyl group-containing compound in 100 mol% of the compound group, and the isocyanate group content at a solid content of 100% by mass. is from 1 to 13 % by weight of a modified polyisocyanate adduct. 2. The curing agent of claim 1, wherein said polyisocyanate adduct is the reaction product of hydrogenated xylylene diisocyanate and trimethylolpropane. An undercoat agent comprising the curing agent according to claim 1 or 2. 4. The undercoating agent according to claim 3, comprising a urethane (meth)acrylic copolymer which is a reaction product of a hydroxyl group-containing (meth)acrylic copolymer and a polyisocyanate. A film having a cured undercoat agent layer containing the cured undercoat agent according to claim 3 or 4 laminated on at least one side of the film.