JP2019172933A - Unsaturated group-containing polyester resin, primer composition, aqueous liquid, substrate film with primer layer, and prism sheet - Google Patents

Abstract

To provide a primer composition containing no urethane resin for forming a primer layer excellent especially in adhesiveness with a prism layer by curing a polyester film and a solventless active energy ray curable resin composition, and an unsaturated group-containing polyester resin forming the primer composition.SOLUTION: There is provided an unsaturated group-containing polyester resin having a carboxyl group in a side chain of a main chain, and an unsaturated group at least at one location of molecular terminals of at least one of the side chain of the main chain and the main chain.SELECTED DRAWING: None

Description

  The present invention relates to an unsaturated group-containing polyester resin, and more specifically, an unsaturated group-containing polyester resin for forming a primer layer on a base film, and a primer composition containing the unsaturated group-containing polyester resin. And an aqueous liquid using the primer composition, a base film with a primer layer, and a prism sheet.

  Conventionally, synthetic resins have been widely used as resins for various substrates because they have excellent properties such as dimensional stability, mechanical properties, heat resistance, transparency, electrical properties, and chemical resistance. For example, polyester films are used in various industrial fields such as packaging materials, magnetic cards, and printing materials. As the polyester film, a thermoplastic polyester such as polyethylene terephthalate (PET) or a copolymer obtained by mixing these resins with other resins as necessary is melt-extruded and then biaxially stretched and heated. A fixed one is used. While such a polyester film is excellent in various physical properties, its surface is highly crystallized, so when a coating layer is provided on the polyester film, there is a problem of poor adhesion to the coating layer. there were.

Therefore, in order to improve the adhesion between the polyester film and the coating layer, studies have been made to impart adhesion to the film surface. For example, an easy adhesion treatment is applied to the film surface, or a primer layer made of various resins is used. The method of providing is known.
However, in recent years, the composition of the coating agent and the like forming the coating layer has been diversified, and depending on the type, the adhesion between the primer layer and the coating layer may not be sufficient, and further improvement in adhesion is required. .

  For example, there is a prism layer as one of the coating layers. As a method for forming the prism layer, for example, an active energy ray curable resin composition is introduced into a prism type, and the active energy ray curable resin composition is irradiated with the active energy ray curable resin composition sandwiched between the prism type and the polyester film. And a method of forming a prism layer formed by curing the active energy ray-curable resin composition on a polyester film by curing the resin composition and removing the prism mold. In the case of such a method, it is necessary to use a solvent-free active energy ray-curable resin in order to form a prism pattern precisely. However, the solvent-free resin has a lower permeation and swelling effect on the primer layer laminated on the polyester film than the solvent-based resin, and a layer formed by curing the active energy ray-curable resin composition. Adhesion with the primer layer tends to be insufficient.

  Therefore, Patent Document 1 has, on at least one surface of the film, a coating layer formed from a coating resin containing a composite resin composed of a resin containing a (meth) acryloyl group and a urethane resin, and a crosslinking agent. A featured laminated film is disclosed, and according to this technique, it is said to be excellent in adhesion to a solventless active energy ray-curable resin used for forming a prism layer.

Japanese Patent Laid-Open No. 2006-64517

  However, in recent years, the composition of the solventless active energy ray curable resin used for forming the prism layer has been diversified, and even the primer composition proposed by the above-mentioned Patent Document 1 does not necessarily have sufficient adhesion. ing.

  In addition, the polyester film film with a primer layer is generally remelted and recycled from film waste generated by slits, etc., and when remelted and recycled using a urethane resin as in Patent Document 1 above. There is a concern that the recycled film may cause yellowing or agglomerated foreign matter due to the urethane resin and impair the quality.

  In view of this, the present invention is based on such a background and provides adhesion between both the base film and the coating layer, particularly the polyester film and the prism layer formed by curing the solventless active energy ray-curable resin composition. An object of the present invention is to provide a primer composition that does not contain a urethane resin and an unsaturated group-containing polyester resin that forms the primer composition for forming an excellent primer layer.

  As a result of intensive studies in view of such circumstances, the present inventor has a carboxyl group in the side chain of the main chain, and has an unsaturated group in either the side chain of the main chain or at least one molecular end of the main chain. By using an unsaturated group-containing polyester resin, a primer layer having excellent adhesion to both the base film and the coating layer, in particular, the prism layer formed by curing the solventless active energy ray-curable resin composition. It was found that a primer composition to be formed was obtained, and the present invention was completed.

That is, the present invention is characterized by the following (1) to (18).
(1) An unsaturated group containing a carboxyl group in the side chain of the main chain and an unsaturated group in at least one of the molecular ends of at least one of the side chain of the main chain and the main chain Polyester resin.
(2) The unsaturated group-containing polyester resin according to (1), wherein the unsaturated group has at least one molecular end of the main chain.
(3) The unsaturated group-containing polyester resin according to (1) or (2), wherein the content of the unsaturated group is 0.005 to 3 mmol / g.
(4) The unsaturated group-containing polyester resin according to any one of (1) to (3), wherein the unsaturated group is a (meth) acryloyl group.
(5) The unsaturated group-containing polyester resin according to any one of (1) to (4), wherein the acid value is 1.5 to 150 mgKOH / g.
(6) The unsaturated group-containing polyester resin according to any one of (1) to (5), wherein the weight average molecular weight is 5,000 to 100,000.
(7) reacting a polyester resin (A) having an acid anhydride structure at at least one molecular end of the main chain with an unsaturated group-containing compound (B) having a functional group capable of reacting with an acid anhydride. The unsaturated group-containing polyester resin according to any one of (1) to (6), wherein
(8) The unsaturated group-containing compound according to (7), wherein the unsaturated group-containing compound (B) having a functional group capable of reacting with the acid anhydride is a polyalkylene glycol mono (meth) acrylate Polyester resin.
(9) An aqueous liquid, wherein the unsaturated group-containing polyester resin according to any one of (1) to (8) is dissolved or dispersed in an aqueous solvent.
(10) A primer composition comprising the unsaturated group-containing polyester resin according to any one of (1) to (8).
(11) The primer composition according to (10), further comprising a crosslinking agent.
(12) The primer composition according to (11), wherein the crosslinking agent is at least one compound selected from the group consisting of an isocyanate compound and a carbodiimide compound.
(13) Any of (10) to (12), wherein the unsaturated group-containing polyester resin in the primer composition has an unsaturated group content of 0.003 to 1 mmol / g. The primer composition according to one.
(14) The content ratio of the unsaturated group-containing polyester resin and the crosslinking agent is 99/1 to 30/70 as the mass of the unsaturated group-containing polyester resin / the mass of the crosslinking agent. (11)-The primer composition as described in any one of (13).
(15) An aqueous liquid, wherein the primer composition according to any one of (10) to (14) is dissolved or dispersed in an aqueous solvent.
(16) A base film with a primer layer, comprising a primer layer comprising the primer composition according to any one of (10) to (14) on a base film.
(17) A prism sheet comprising a prism layer on the primer layer of the substrate film with a primer layer according to (16).
(18) The prism sheet according to (17), wherein the prism layer is a cured product of a solventless active energy ray-curable resin composition.

The primer composition containing the unsaturated group-containing polyester resin of the present invention is excellent in adhesion between both the base film and the coating layer, and is particularly used for forming a polyester film and, for example, a prism layer. Excellent adhesion to a layer formed by curing the solventless active energy ray-curable resin composition.
Therefore, the primer composition can be suitably used as a primer for providing a coating layer, particularly a prism layer, on a polyester resin substrate such as a polyester film.

The present invention is described in detail below, but these show examples of desirable embodiments.
In the present invention, “(meth) acryloyl group” means acryloyl group or methacryloyl group, and “(meth) acrylate” means acrylate or methacrylate.
In the present invention, the term “carboxylic acid” includes carboxylates, carboxylic anhydrides, carboxylic halides, carboxylic esters and the like.
In the present invention, the “sheet” conceptually includes a sheet, a film, and a tape.

[Unsaturated group-containing polyester resin]
The unsaturated group-containing polyester resin of the present invention has a carboxyl group in the side chain of the main chain and has an unsaturated group in at least one of the molecular ends of at least one of the side chain of the main chain and the main chain. It is characterized by that.

  A crosslinked structure is formed by reacting the unsaturated group-containing polyester resin of the present invention with a crosslinking agent described later. And in this crosslinked structure, the molecular mobility of the polyester structure part of this unsaturated group containing polyester-type resin is restrict | limited. On the other hand, the unsaturated group present in at least one of the side chain of the main chain and at least one molecular end of the main chain of the unsaturated group-containing polyester resin has a relatively high degree of steric and spatial freedom. It is in a high state. Therefore, for example, when the polyester resin of the present invention is used in a primer composition for forming a primer layer provided between a base film and a coating layer, the unsaturated group of the polyester resin of the present invention is a reactive group. As segregated on the surface of the primer layer.

  Therefore, when a prism layer formed by, for example, curing a solventless active energy ray-curable resin composition is laminated as a coating layer on the primer layer, the surface of the prism layer is cured by active energy ray irradiation. The segregated unsaturated group in the primer layer and the active species derived from the carbon-carbon double bond in the prism layer react with each other and combine to increase the adhesion between them.

  In the present invention, the unsaturated group is preferably located at at least one molecular end of the main chain of the unsaturated group-containing polyester resin. For example, when the prism layer is laminated as a coating layer on the primer layer, the detailed reason is not clear, but when the unsaturated group is located at the molecular end of the main chain, the molecular mobility of the unsaturated group is reduced. It is considered that it becomes higher so that it is easily segregated on the surface of the primer layer and easily reacts with the carbon-carbon double bond in the prism layer.

  As the unsaturated group in the unsaturated group-containing polyester resin of the present invention, a conventionally known functional group is used as long as it can react with the carbon-carbon double bond contained in the compound forming the prism layer or the like. Examples thereof include a vinyl group, a vinyl ether group, a vinyl ester group, and a (meth) acryloyl group. Of these, a (meth) acryloyl group is preferable and an acryloyl group is particularly preferable from the viewpoint of the reactivity (adhesiveness) between the coating layer and the primer layer.

  The unsaturated group content of the unsaturated group-containing polyester resin of the present invention is preferably 0.005 to 3 mmol / g, particularly 0.01 to 1 mmol / g, particularly 0.03 to 0.8 mmol / g. g, more preferably 0.05 to 0.4 mmol / g. If the content is too low, there is a tendency that sufficient adhesion cannot be obtained due to insufficient reaction points with the prism layer, and if the content is too large, the molecular weight of the unsaturated group-containing polyester resin is lowered, and the coating strength. There exists a tendency for adhesiveness to fall by fall.

In addition, content of the unsaturated group of the unsaturated group containing polyester resin of this invention can be calculated | required by following formula (I).
Unsaturated group content (mmol / g) = (P1 _m × P1 _n ) / (P1 _mw × S1) Formula (I)
In formula (I), P1 _m is the mass (mg) of the unsaturated group-containing compound, P1 _n is the number of unsaturated groups per molecule of the unsaturated group-containing compound, and P1 _mw is the molecular weight (g / g) of the unsaturated group-containing compound. mol), S1 is the solid content mass (g) of the unsaturated group-containing polyester resin.

  The acid value of the unsaturated group-containing polyester resin of the present invention is preferably 1.5 to 150 mgKOH / g, particularly 4 to 100 mgKOH / g, particularly 10 to 70 mgKOH / g, and more preferably 15 to 40 mgKOH / g. preferable. If the acid value is too low, water dispersion tends to be difficult, and adhesion and wet heat resistance tend to decrease due to insufficient crosslinking with the crosslinking agent. On the other hand, if the acid value is too high, the water resistance tends to decrease.

  In addition, the acid value in this invention originates in content of the carboxyl group in unsaturated group containing polyester resin. Further, the carboxyl group referred to in the present invention includes those in a carboxylate ion state in which the carboxyl group is neutralized with a basic compound. The acid value is obtained by neutralization titration based on JIS K0070.

  The weight-average molecular weight of the unsaturated group-containing polyester resin of the present invention is preferably 5,000 to 100,000, particularly 6,000 to 50,000, particularly 8,000 to 40,000, and further 13 30,000 to 30,000 are preferred. If the weight average molecular weight is too low, the adhesion and wet heat resistance tend to decrease, and if the weight average molecular weight is too high, the adhesion and water dispersibility tend to decrease.

In addition, a weight average molecular weight is a weight average molecular weight by standard polystyrene molecular weight conversion, a column: TSKgel SuperMultipore HZ-M (exclusion limit molecular weight: 2 * 10) in a high performance liquid chromatography (the Tosoh company make, "HLC-8320GPC"). ⁶ , theoretical plate number: 16,000 plate / line, filler material: styrene-divinylbenzene copolymer, filler particle size: 4 μm) are used in series.

  The unsaturated group-containing polyester resin of the present invention is, for example, described as a polyester resin (A) having an acid anhydride structure at at least one molecular end of the main chain (hereinafter referred to as “polyester resin (A)”). And an unsaturated group-containing compound (B) having a functional group capable of reacting with an acid anhydride (hereinafter sometimes referred to as “unsaturated group-containing compound (B)”). Can be obtained.

<Polyester resin (A) having an acid anhydride structure at at least one molecular end of the main chain>
The polyester resin (A) can be obtained by copolymerizing the polyvalent carboxylic acid component (a1) and the polyol component (a2).

[Polyvalent carboxylic acid component (a1)]
The polyvalent carboxylic acid component (a1) may be a divalent or higher polyvalent carboxylic acid, and preferably contains at least a divalent carboxylic acid.

Examples of the divalent carboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, benzylmalonic acid, diphenic acid, 4,4′-oxydibenzoic acid, naphthalenedicarboxylic acid, and dimethyl sodium 5-sulfoisophthalate;
Malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, thiodipropionic acid , Aliphatic dicarboxylic acids such as diglycolic acid;
Alicyclics such as 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, adamantanedicarboxylic acid, etc. Dicarboxylic acids;
Etc.
These may be used alone or in combination of two or more.

  Among these, at least one of aromatic dicarboxylic acid and alicyclic dicarboxylic acid is mainly used from the viewpoint of adhesion of the primer layer to the coating layer and stability of the aqueous liquid when dissolved or dispersed in an aqueous solvent. It is preferable to use it as a component. In particular, it is preferable to use aromatic dicarboxylic acid as a main component, and it is preferable to use isophthalic acid as a main component from the viewpoint of excellent adhesion.

  Here, the main component means that it is usually contained in an amount of 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more based on the whole polyvalent carboxylic acid component (a1).

  The content ratio of the divalent carboxylic acid is preferably 70 to 97 mol%, particularly 80 to 97 mol%, more preferably 85 to 96 mol%, particularly with respect to the whole polyvalent carboxylic acid component (a1). Is preferably 90 to 95 mol%. If the content is too low, the heat and humidity resistance tends to decrease or gelation occurs during the production process. If the content is too high, water dispersion tends to be difficult.

  In the present invention, a trivalent or higher polyvalent carboxylic acid can be used for the purpose of increasing branch points in the polyester resin (A). Examples of the trivalent or higher polyvalent carboxylic acid include trimellitic acid, pyromellitic acid, adamantanetricarboxylic acid, and trimesic acid.

  In the present invention, the polyester-based resin (A) is a reactive point of the unsaturated group-containing compound (B), preferably a (meth) acrylate-based compound in the polyester-based resin (A) and a reactive point with a crosslinking agent described later. Carboxylic acid anhydride having two or more carboxylic acid anhydride structures as the polyvalent carboxylic acid component (a1) in that it has a function of forming a chain, a function as a chain extender, and a function as a hydrophilicity imparting agent. a11) (hereinafter sometimes referred to as “carboxylic anhydride (a11)”).

  The carboxylic acid anhydride (a11) may be any one having at least two carboxylic acid anhydride structures.

Specific examples of the carboxylic acid anhydride (a11) include, for example,
1,2,4,5-benzenetetracarboxylic dianhydride (pyromellitic anhydride), 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 4,4-oxydiphthalic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, ethylene glycol bistrimellitate dianhydride, 2,2 ', 3,3' -Aromatic carboxylic acid anhydrides such as diphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-diphenylsulfonetetracarboxylic anhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride object;
1,2,3,4-cyclobutanetetracarboxylic dianhydride, 5- (2,5 dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 5- (2, Alicyclic carboxylic acid anhydrides such as 5-dioxotetrahydrofuryl) -3-cyclohexene-1,2-dicarboxylic acid anhydride, cyclopentanetetracarboxylic dianhydride;
Aliphatic carboxylic anhydrides such as ethylenetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-pentanetetracarboxylic dianhydride;
Etc.
These may be used alone or in combination of two or more.

  Among these, tetracarboxylic dianhydride is preferable from the viewpoint of hardly causing gelation during resin production, and among them, aromatic tetracarboxylic dianhydride is preferable from the viewpoint of adhesion between the coating layer and the primer layer. 1,2,4,5-benzenetetracarboxylic dianhydride (pyromellitic anhydride) is preferred.

  The content ratio of the carboxylic acid anhydride (a11) in the polyvalent carboxylic acid component (a1) is preferably 2 to 30 mol%, particularly 3 to 20%, based on the entire polyvalent carboxylic acid component (a1). It is preferable that it is mol%, further 4-15 mol%, especially 5-10 mol%. If the content is too low, it is difficult to disperse water when the produced polyester resin is dispersed in an aqueous solvent, or the crosslinking point with the crosslinking agent is insufficient, resulting in decreased adhesion and moisture heat resistance. Tend. If the content is too high, the gelation during the manufacturing process, the hydrophilicity increases, the moisture and heat resistance decreases, the molecular weight hardly increases, the adhesion with the coating layer decreases, Since the crosslink density becomes too high, the adhesion with the coating layer tends to decrease.

[Polyol component (a2)]
Examples of the polyol component (a2) include linear aliphatic diols, other dihydric alcohols, and trihydric or higher polyhydric alcohols.

  As the aliphatic diol having a linear structure, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1 , 9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, polyethylene glycol, polytetramethylene glycol and the like.

Examples of other dihydric alcohols include propylene glycol, dipropylene glycol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2-methyl-1,3-propanediol, and 2,2-dimethyl. -1,3-propanediol (neopentyl glycol), 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,3-butanediol, Aliphatic diols having a branched structure such as 3-methyl-1,5-pentanediol and 2,2,4-trimethyl-1,6-hexanediol;
1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, spiroglycol, tricyclodecane dimethanol, adamantanediol, 2,2,4,4-tetramethyl-1,3 -Alicyclic diols such as cyclobutanediol;
4,4'-thiodiphenol, 4,4'-methylenediphenol, bisphenol S, bisphenol A, bisphenol fluorene, 4,4'-dihydroxybiphenyl, o-, m- and p-dihydroxybenzene, 2,5- Aromatic diols such as naphthalenediol and p-xylenediol;
And these ethylene oxide and propylene oxide adducts;
Etc.

  Examples of the trihydric or higher polyhydric alcohol include pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, trimethylolpropane, trimethylolethane, 1,3,6-hexanetriol, adamantanetriol, and the like.

  Among these, it is preferable to use an aliphatic diol having a linear structure from the viewpoint of adhesion between the coating layer and the primer layer, and further, ethylene glycol is excluded from the viewpoint of having an appropriate flexibility and excellent adhesion. It is preferable to use an aliphatic diol having a straight chain structure, and it is particularly preferable to use diethylene glycol, 1,4-butanediol, 1,5-pentanediol, or 1,6-hexanediol. It is preferable to use diethylene glycol in that the degree of conversion decreases and the adhesion is more excellent.

  Further, from the viewpoint of the stability of the aqueous liquid when dissolved or dispersed in an aqueous solvent, it is preferable to use an aliphatic diol having a linear structure and other polyol components in combination, and further, the coating layer and the primer layer. From the viewpoint of adhesion, it is preferable to use an aliphatic diol having a linear structure and an aliphatic polyol having a branched structure, and particularly as an aliphatic polyol having a branched structure, neopentyl glycol, 2-methyl-1, It is preferable to use 3-propanediol or butylethylpropanediol, and particularly preferably neopentyl glycol.

When the aliphatic diol having a linear structure and other polyol components are used in combination, the ratio (molar ratio) of the aliphatic diol having a linear structure and the other polyol component is determined as follows. The polyol component is preferably 98/2 to 50/50, more preferably 95/5 to 60/40, and particularly preferably 90/10 to 70/30.
When there are too many polyol components other than the aliphatic diol of a linear structure, there exists a tendency for adhesiveness to fall, and when too small, there exists a tendency for stability of aqueous liquid to fall.

[Production method of polyester resin (A)]
The polyester resin (A) can be obtained by copolymerizing a copolymer component containing the polyvalent carboxylic acid component (a1) and the polyol component (a2). It can be produced by a method in which a carboxylic acid anhydride (a11) is reacted with a hydroxyl group-containing prepolymer obtained by copolymerizing a monovalent carboxylic acid component (a1) and a polyol component (a2).

  First, a predetermined amount of the polyvalent carboxylic acid component (a1) excluding the carboxylic acid anhydride (a11) and the polyol component (a2) are mixed without a solvent. At this time, the mixing ratio (molar ratio) of the polyvalent carboxylic acid component (a1) excluding the carboxylic acid anhydride (a11) and the polyol component (a2) is a polyol with respect to 1 mol of the polyvalent carboxylic acid component (a1). The component (a2) is preferably 1.02 to 1.3 mol, more preferably 1.03 to 1.2 mol, and particularly preferably 1.04 to 1.1 mol.

  This mixture is charged into an appropriate reactor and heated to 170 to 270 ° C., usually, while distilling off water or methanol as a by-product, the esterification reaction or transesterification reaction proceeds, and a hydroxyl group-containing prepolymer is obtained. A polymer is produced.

  Furthermore, a polyester-based resin (A) having an acid anhydride structure at at least one molecular terminal of the main chain can be obtained by ring-opening addition reaction using the carboxylic acid anhydride (a11) to the hydroxyl group-containing prepolymer. it can.

  When the carboxylic acid anhydride (a11) is reacted with the hydroxyl group-containing prepolymer, [1] molar ratio of hydroxyl group to carboxylic acid anhydride (a11) in the hydroxyl group-containing prepolymer (mol of carboxylic acid anhydride (a11)) Number / number of moles of the hydroxyl group) is 1 or more, the carboxylic acid anhydride (a11) reacts at the terminal of the hydroxyl group-containing prepolymer, and the hydroxyl group-containing prepolymer has an acid anhydride structure at the terminal; Become.

[2] Even if the molar ratio is greater than 0 and less than 1, the molar ratio of the hydroxyl group of the hydroxyl group-containing prepolymer to the acid anhydride group of the carboxylic acid anhydride (a11) (number of moles of the acid anhydride group / When the number of moles of hydroxyl groups is greater than 1, the hydroxyl group-containing prepolymer is chain-extended and has an anhydride structure at the terminal.
In the present invention, in the case of the above [2], the weight average molecular weight of the unsaturated group-containing polyester resin of the present invention tends to be within the above-mentioned preferred range, and the adhesion between the coating layer and the primer layer tends to be higher. Because there is, it is preferable.

  When the carboxylic acid anhydride (a11) is reacted with the hydroxyl group-containing prepolymer, the reaction is usually performed at 230 ° C. or lower, preferably 150 to 210 ° C., particularly preferably 160 to 190 ° C. when no catalyst is used. When a catalyst is used, the reaction can be performed at room temperature to 100 ° C, preferably 40 to 90 ° C.

  The catalyst is not particularly limited, but an amine catalyst is preferable, and triethylamine is particularly preferable because it easily volatilizes during the drying process.

  Moreover, an esterification catalyst, a transesterification catalyst, other polymerization catalysts, etc. can be mix | blended suitably, for example, tetrabutoxy titanium can be used as an esterification catalyst. Moreover, you may use various additives, such as another stabilizer.

  In the above reaction, a solvent is not always necessary, but when the viscosity of the reaction product at the above temperature is too high, an appropriate solvent can be appropriately used to facilitate stirring.

Examples of such solvents include ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, aromatic solvents such as benzene, toluene, xylene, mesitylene, and pseudocumene, and amide solvents such as dimethylformamide and dimethylacetamide. . In addition, it is preferable not to use a solvent that may react with the polyester resin such as an ester solvent and an alcohol solvent.
Thus, the polyester resin (A) is obtained by the above-described method.

  The polyester-based resin (A) needs to have a carboxyl group in the side chain of the main chain, and the carboxyl group is preferably derived from the carboxylic acid anhydride (a11), preferably pyromellitic acid. .

<Unsaturated group-containing compound (B) having a functional group capable of reacting with acid anhydride>
The unsaturated group-containing compound (B) has a functional group that can react with an acid anhydride. The unsaturated group-containing compound (B) may be a monofunctional compound containing one unsaturated group in the molecule or a polyfunctional compound containing two or more unsaturated groups in the molecule. In particular, in the present invention, the unsaturated group-containing compound (B) is preferably a (meth) acryloyl group-containing compound in terms of adhesion to the coating layer.

  As the functional group capable of reacting with the acid anhydride, conventionally known functional groups can be used, and examples thereof include a hydroxyl group, an amino group, a mercapto group, and an epoxy group. Among these, a hydroxyl group and an epoxy group are preferable from the viewpoint of hue and odor, and a hydroxyl group is particularly preferable from the viewpoint of reactivity.

  As the monofunctional compound, monofunctional (meth) acrylate is preferable. Examples of the monofunctional (meth) acrylate include polyalkylene glycol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxy Butyl (meth) acrylate, ethylene glycol-propylene glycol block copolymer mono (meth) acrylate, ethylene glycol-tetramethylene glycol copolymer mono (meth) acrylate, caprolactone-modified mono (meth) acrylate, glycidyl (meth) acrylate, 4-hydroxy Examples include butyl (meth) acrylate glycidyl ether.

  As the polyfunctional compound, polyfunctional (meth) acrylate is preferable. Examples of the polyfunctional (meth) acrylate include trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and the like. In addition, other examples include hydroxyl group-containing polybutadiene, a polymer having a functional group capable of reacting with a terminal unsaturated group and an acid anhydride group, and an oligomer.

  Among these, as the unsaturated group-containing compound (B), those having a (meth) acryloyl group are preferable from the viewpoint of adhesion between the coating layer and the primer layer, and in particular, a (meth) acryloyl group and a polyoxyalkylene group. In particular, those having an acryloyl group and a polyoxyalkylene group are preferred, and polyalkylene glycol monoacrylate is more preferred.

  Examples of the polyalkylene glycol monoacrylate include polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, polybutylene glycol monoacrylate and the like, and those having a primary hydroxyl group from the viewpoint of reactivity with an acid anhydride group (polyethylene) Glycol monoacrylate and polybutylene glycol monoacrylate), and polyethylene glycol monoacrylate is more preferable from the viewpoint of adhesion between the coating layer and the primer layer.

<Method for Producing Unsaturated Group-Containing Polyester Resin of the Present Invention>
As described above, the unsaturated group-containing polyester resin of the present invention can be obtained, for example, by reacting a polyester resin (A) with an unsaturated group-containing compound (B).

Specifically, for example, the polyester-based resin (A) and the unsaturated group-containing compound (B) are usually in a solvent in the presence of a catalyst, usually at room temperature to 100 ° C., preferably 40 to 90 ° C. and usually 0.5 to 10 hours. The functional group capable of reacting with the acid anhydride group in the polyester resin (A) and the acid anhydride group in the unsaturated group-containing compound (B), preferably by mixing under conditions of 1 to 5 hours Can be reacted.
The catalyst is not particularly limited, but an amine catalyst is preferable, and triethylamine is particularly preferable because it easily volatilizes during the drying process.

  The acid anhydride group in the polyester-based resin (A) and the functional group capable of reacting with the acid anhydride group in the unsaturated group-containing compound (B) are opened to open the polyester. At the same time that the carboxyl group is added to the side chain of the resin (A), the unsaturated group-containing compound (B) can be added to the polyester resin (A). That is, an unsaturated group can be introduced into the polyester resin (A).

  At this time, the molar ratio of the functional group capable of reacting with the acid anhydride group in the polyester resin (A) and the acid anhydride in the unsaturated group-containing compound (B) is polyester resin ( The functional group capable of reacting with the acid anhydride in the unsaturated group-containing compound (B) is preferably 0.8 to 1.2 mol relative to 1 mol of the acid anhydride group in A). It is more preferable to set it to -1.1 mol, and it is especially preferable to set it as 0.95-1.05.

  Thus, an unsaturated group-containing polyester resin having a carboxyl group in the side chain of the main chain and having an unsaturated group in at least one molecular end of at least one of the side chain of the main chain and the main chain is obtained. Can do.

  It should be noted that the unsaturated group-containing polyester resin of the present invention includes hindered phenol-based antioxidants, heat stabilizers, glass fibers, inorganic / organic fillers, colorants, flame retardants, softening as necessary. An agent, a dispersant, a wetting agent, an emulsifier, a gelling agent, an antifoaming agent, another thermoplastic resin, and the like can be blended to such an extent that the effects of the present invention are not impaired.

[Primer composition]
By including the unsaturated group-containing polyester resin of the present invention obtained as described above, the primer composition of the present invention can be obtained. The primer composition of the present invention preferably further contains a crosslinking agent.

<Crosslinking agent>
The crosslinking agent used in the present invention only needs to cause a crosslinking reaction with the carboxyl group in the unsaturated group-containing polyester resin of the present invention. For example, an isocyanate compound, an oxazoline compound, an epoxy compound, a carbodiimide compound , Amine compounds, metal compounds, aziridine compounds, hydrazine compounds, hydrazide compounds, and melamine compounds.

  The isocyanate compound may be any compound containing at least two isocyanate groups as functional groups in the molecule. For example, “Aquanate 110”, “Aquanate 210”, Daiichi Kogyo Seiyaku, manufactured by Nippon Polyurethanes, Inc. “Elastotron BN-27”, “Elastoron BN-77”, “Meikanate TP-10”, “SU-268A” manufactured by Meisei Chemical Industry Co., Ltd., “Trixene aqua BI200”, “Trixene” manufactured by Baxen Chemical Limited aqua BI220 "and the like.

Especially, in order to avoid yellowing by an ultraviolet-ray, an aliphatic isocyanate type compound or an alicyclic isocyanate type compound is more preferable than an aromatic isocyanate type compound.
From the viewpoint of stability, a functional group block type is preferable, and “SU-268A”, “Trixene aqua BI220” and the like are preferable.

  Examples of the oxazoline-based compound include addition-polymerizable 2-oxazoline (for example, 2-isopropenyl-2-oxazoline) having a substituent having an unsaturated carbon-carbon bond at the 2-position carbon position and other unsaturated monovalent compounds. Examples of commercially available products include “Epocross WS-500”, “Epocross WS-700”, “Epocross K-2010E”, and “Epocross K-2020E” manufactured by Nippon Shokubai Co., Ltd. , “Epocross K-2030E” and the like.

  Examples of the epoxy compound include bisphenol A / epichlorohydrin type epoxy resin, sorbitol polyglycidyl ether (for example, “Denacol EX-611”, “Denacol EX-612”, “Denacol EX-614” manufactured by Nagase ChemteX Corporation). , “Denacol EX-614B”, “Denacol EX-622”, etc.), polyglycerol polyglycidyl ether (for example, “Denacol EX-512”, “Denacol EX-521”, etc., manufactured by Nagase ChemteX Corporation), pentaerythritol poly Glycidyl ether (for example, “Denacol EX-411” manufactured by Nagase ChemteX), diglycerol polyglycidyl ether (for example, “Denacol EX-421” manufactured by Nagase ChemteX), etc., glycerol polyglycy Ruether (for example, “Denacol EX-313”, “Denacol EX-314”, etc., manufactured by Nagase ChemteX), trimethylolpropane polyglycidyl ether (eg, “Denacol EX-321”, etc., manufactured by Nagase ChemteX), Resorcinol diglycidyl ether (for example, “Denacol EX-201” manufactured by Nagase ChemteX), neopentyl glycol diglycidyl ether (for example, “Denacol EX-211” manufactured by Nagase ChemteX), 1,6- Hexanediol diglycidyl ether (for example, “Denacol EX-212” manufactured by Nagase ChemteX Corporation), hydrogenated bisphenol A diglycidyl ether (eg, “Denacol EX-252” manufactured by Nagase ChemteX Corporation), Ethylene Cole diglycidyl ether (for example, “Denacol EX-810”, “Denacol EX-811”, etc., manufactured by Nagase ChemteX Corporation), diethylene glycol diglycidyl ether (eg, “Denacol EX-850”, “ Denacol EX-851 "), polyethylene glycol diglycidyl ether (for example," Denacol EX-821 "," Denacol EX-830 "," Denacol EX-832 "," Denacol EX-841 "manufactured by Nagase ChemteX Corporation, “Denacol EX-861”, etc.), propylene glycol diglycidyl ether (eg, “Denacol EX-911” etc., manufactured by Nagase ChemteX), polypropylene glycol diglycidyl ether (eg, “Denaco” manufactured by Nagase ChemteX) EX-941 "," Denacol EX-920 "," Denacol EX-931 "and the like. Among them, the aqueous type is preferable, and a bifunctional and linear structure such as ethylene glycol diglycidyl ether and diethylene glycol diglycidyl ether is particularly preferable from the viewpoint of adhesion between the coating layer and the primer layer.

  As the carbodiimide-based compound, any carbodiimide group having at least two cyanamide groups in the molecule as a functional group or a tautomeric relationship thereof may be used. For example, “Carbodilite V— manufactured by Nisshinbo Chemical Co., Ltd. 02 ”,“ Carbodilite V-02-L2 ”,“ Carbodilite SV-02 ”,“ Carbodilite V-04 ”,“ Carbodilite V-10 ”,“ Carbodilite E-03A ”,“ Carbodilite E-02 ”,“ Carbodilite E ” -04 "and the like. Among them, those having an aromatic group such as a xylylene skeleton, a tolylene skeleton, a diphenylmethane skeleton, and a tetramethylxylylene skeleton are preferable from the viewpoint of adhesion between the coating layer and the primer layer, and in particular, "Carbodilite V-04" E-04 "and the like are preferable.

  Examples of the amine compound include hexamethylenediamine and triethanolamine.

  Examples of metal compounds include metal alkoxides such as tetraethyl titanate, tetraethyl zirconate, and aluminum isopropionate, and aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, zirconium, and the like. Examples include polyvalent metal acetylacetone and acetoacetate, metal chelate compounds of ethylenediaminetetraacetic acid coordination compounds, acetic acid-ammonium complex salts, ammonium-carbonate complex salts, and the like.

  Any aziridine compound may be used as long as it contains at least two aziridine groups. Examples thereof include “Chemite PZ-33” and “Chemite DZ-22E” manufactured by Nippon Shokubai Co., Ltd.

  Any hydrazine-based compound may be used as long as it contains at least two hydrazine groups. Examples thereof include hydrazine monohydrochloride, hydrazine dihydrochloride, hydrazine monohydrobromide, and hydrazine carbonate.

  Examples of the hydrazide compound include adipic acid dihydrazide, sebacic acid dihydrazide, dodecanediohydrazide, isophthalic acid dihydrazide, salicylic acid hydrazide, and the like.

  Examples of the melamine compound include hexamethoxymethylol melamine, “Nicarak MW-30M”, “Nicarac MW-30”, “Nicarac MW-22”, “Nicarac MS-11”, “Nicarac” manufactured by Sanwa Chemical Co., Ltd. MS-011, “Nicarax MX-730”, “Nicarax MX-750”, “Nicarax MX-706”, “Nicarax MX-035” and other methylated melamine resins, “Nicarax MX-45”, “Nicarac MX- Mixed etherified melamine resin such as "410".

  As a crosslinking agent, only 1 type chosen from these may be used, and 2 or more types may be used together.

  In the present invention, from the viewpoint of adhesion between the coating layer and the primer layer, among them, an isocyanate compound, an oxazoline compound, an epoxy compound, and a carbodiimide compound are preferable, an isocyanate compound and a carbodiimide compound are particularly preferable, and a carbodiimide. More preferred is a compound of the type.

  In particular, the primer layer is preferably thin from the viewpoint of cost and transparency, but the adhesiveness tends to decrease when the thickness is thin. The use of agents is particularly effective.

  The content of the crosslinking agent can be appropriately selected depending on the amount of the functional group contained in the unsaturated group-containing polyester resin of the present invention, the molecular weight of the unsaturated group-containing polyester resin of the present invention, and the purpose of use. The mass ratio of the unsaturated group-containing polyester resin to the crosslinking agent (the mass of the unsaturated group-containing polyester resin of the present invention / the mass of the crosslinking agent) is preferably 99/1 to 30/70, particularly 95/5. -40/60, in particular 90 / 10-50 / 50, more preferably 80 / 20-60 / 40.

  If the content of the cross-linking agent is too much or too little, the adhesion and wet heat resistance tend to decrease due to insufficient crosslinking.

  Further, the unsaturated group content of the unsaturated group-containing polyester resin of the present invention in the primer composition of the present invention is preferably 0.003 to 1 mmol / g, particularly 0.005 to 0.5 mmol / g. Is more preferable, and 0.01 to 0.3 mmol / g is more preferable.

  If the content is too low, there is a tendency that sufficient adhesion cannot be obtained due to a lack of reaction points with the coating layer. If the content is too large, the adhesion due to a decrease in the molecular weight of the polyester resin and a decrease in coating strength. Tends to decrease.

In addition, content of the unsaturated group of the unsaturated group containing polyester resin of this invention in the primer composition of this invention can be calculated | required by following formula (II).
The content of unsaturated groups (mmol / g) = (P2 m × P2 n) / (P2 mw × S2) ··· formula (II)
In the formula (II), P2 _m is the mass (mg) of the unsaturated group-containing compound, P2 _n is the number of unsaturated groups per molecule of the unsaturated group-containing compound, and P2 _mw is the molecular weight (g / g) of the unsaturated group-containing compound. mol), S2 is the total solid mass (g) of the primer composition.

  In addition to the above components, the primer composition of the present invention, if necessary, hindered phenol-based antioxidants, heat stabilizers, glass fibers, inorganic / organic fillers, colorants, flame retardants, softening An agent, a dispersant, a wetting agent, an emulsifier, a gelling agent, an antifoaming agent, another thermoplastic resin, and the like can be blended to such an extent that the effects of the present invention are not impaired.

  The method for producing the primer composition of the present invention is not particularly limited, and for example, each component may be appropriately mixed using a stirrer.

[Aqueous liquid]
The aqueous liquid of the present invention is obtained by dissolving or dispersing the unsaturated group-containing polyester resin of the present invention or the primer composition of the present invention in an aqueous solvent. Hereinafter, dissolution or dispersion in an aqueous solvent is referred to as “water dissolution or dispersion”.

  The aqueous liquid of the present invention can be prepared by appropriately mixing the unsaturated group-containing polyester resin of the present invention or the primer composition of the present invention and an aqueous solvent. For example, (1) A method in which an unsaturated group-containing polyester resin and a crosslinking agent are mixed, and then an aqueous solvent is mixed to form an aqueous liquid. (2) Each of the unsaturated group-containing polyester resin and the crosslinking agent of the present invention is aqueous with an aqueous solvent. (3) Either of the unsaturated group-containing polyester resin and the crosslinking agent of the present invention is made into an aqueous solution with an aqueous solvent, and the remaining components are further mixed to form an aqueous solution. Although the method of using a liquid etc. is mentioned, the method of said (2) is preferable at a point with easy preparation.

  Examples of the aqueous solvent include water or water mixed with an appropriate hydrophilic organic solvent. Examples of the hydrophilic organic solvent include ketones such as acetone and methyl ethyl ketone; alcohols such as methanol, ethanol and isopropyl alcohol; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monobutyl ether and ethylene glycol monotertiary butyl ether. Etc., which can be mixed with water. When using a hydrophilic organic solvent, the ratio with respect to the whole aqueous liquid is set suitably. For example, although it can be set as the range of 30 mass% or less, it is not limited to this. Moreover, 1 type chosen from these aqueous solvents may be used, or 2 or more types may be used in combination.

  When preparing the aqueous liquid of the present invention, it is preferable to add a neutralizing agent in order to uniformly dissolve or disperse it in an aqueous medium, and such a neutralizing agent is contained in the primer composition of the present invention. What is necessary is just to be able to neutralize the carboxyl group of the unsaturated group-containing polyester resin and the crosslinking agent of the present invention.

  Specifically, for example, metal hydroxide such as lithium hydroxide, potassium hydroxide, sodium hydroxide; ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, iminobispropylamine, 3-ethoxypropylamine, 3- Organic amines such as diethylaminopropylamine, diethanolamine, triethanolamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine; and ammonia Can be mentioned. One kind selected from these neutralizing agents may be used, or two or more kinds may be used in combination.

  Among these neutralizing agents, it is preferable that they have a boiling point of 150 ° C. or less in terms of water resistance of the resulting film, which is easily volatilized by drying. In particular, ammonia and triethylamine are preferable, and ammonia is particularly preferable because of its high versatility, low boiling point, and ease of volatilization during drying.

  Moreover, surfactants, such as an anionic surfactant and a nonionic surfactant, can be mix | blended with this aqueous liquid as needed. By blending the surfactant, the wettability to the base film when the aqueous liquid is applied to the base such as a polyester film can be improved.

As the surfactant, an appropriate one can be used, for example, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, glycerin fatty acid ester, fatty acid metal soap, alkyl sulfate, alkyl sulfonate, Examples thereof include alkylsulfosuccinate and dodecylbenzenesulfonate. One kind selected from these surfactants may be used, or two or more kinds may be used in combination.
From the viewpoint of adhesion between the coating layer and the primer layer and water resistance of the primer layer, it is preferable not to add a surfactant.

  Moreover, you may mix | blend an antistatic agent, a filler, a ultraviolet absorber, a lubricant, a coloring agent etc. with the aqueous liquid of this invention as needed further.

  The solid content concentration of the aqueous liquid of the present invention is appropriately adjusted so as to ensure good dispersibility of the unsaturated group-containing polyester resin of the present invention, and is preferably 5 to 30% by mass, for example. In addition, at the time of application | coating, it dilutes suitably in order to obtain a desired film thickness, for example, it adjusts and uses solid content concentration to 1-15 mass%.

[Base film with primer layer]
By applying the above aqueous liquid to a substrate film and drying by heating, a film (primer layer) in which the unsaturated group-containing polyester resin in the primer composition is crosslinked by a crosslinking agent is formed, and the primer layer An attached base film can be obtained.

Examples of the base film include polyester resins such as polyethylene naphthalate, polyethylene-2,6-naphthalate, polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / isophthalate copolymer; polyethylene, polypropylene, polymethylpentene, and the like. Polyolefin resins such as polyvinyl fluoride, polyvinylidene fluoride, and polyfluorinated ethylene; polyamides such as nylon 6 and nylon 6, 6; polyvinyl chloride, polyvinyl chloride / vinyl acetate copolymer, ethylene Vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, vinyl polymers such as polyvinyl alcohol and vinylon; cellulose resins such as cellulose triacetate and cellophane; polymethyl methacrylate, Ethyl Li methacrylate, polyethyl acrylate, acrylic resins such as polybutyl acrylate; polystyrene, polycarbonate, polyarylate, single layer material or a multi-layer products thereof are selected from synthetic resin film or sheet such as polyimide.
Of these, polyester films are preferably used from the viewpoints of transparency, chemical resistance, heat resistance, mechanical strength, cost, and the like.
The polyester film may be either an unstretched film or a stretched film, but a stretched film is preferably used, and a biaxially stretched film is particularly preferable.

  As a method for applying the aqueous liquid, a known general method can be used. For example, a method of applying a kiss coat, a reverse coat, a gravure coat, a die coat or the like to one side or both sides of a base film can be mentioned.

  The thickness of the primer layer after heat drying (after crosslinking) is preferably 0.01 to 2 μm, more preferably 0.02 to 0.5 μm, particularly 0.03 to 0.3 μm, It is preferable that it is 0.05-0.15 micrometer. If the thickness is too thin, the adhesion tends to decrease, and if the thickness is too thick, the optical properties such as transparency and haze and blocking resistance tend to decrease.

  A laminated film and a prism sheet can be obtained by providing a coating layer on the primer layer of the substrate film with a primer layer and using the coating layer as a hard coat layer or a prism layer.

  Examples of the material for forming the coating layer include acrylic resins, epoxy resins, urethane resins and active energy ray-curable resin compositions that are generally used as coating materials. A functional resin composition is preferred.

  Specifically, by applying an active energy ray-curable resin composition on the primer layer of the base material film with the primer layer and irradiating and curing the active energy ray, the primer of the base material film with the primer layer A laminated film having a hard coat layer formed by curing the active energy ray-curable resin composition on the layer can be obtained.

  The thickness of the hard coat layer is usually 0.5 to 15 μm, preferably 1 to 10 μm, and particularly preferably 2 to 7 μm.

[Prism sheet]
Moreover, a prism layer can be formed on the primer layer of the substrate film with a primer layer to obtain a prism sheet.

  The prism layer is preferably a prism layer formed by curing an active energy ray-curable resin composition, and particularly preferably a prism layer formed by curing a solventless active energy ray-curable resin composition. is there.

  As a method for forming a prism layer when the prism layer is a prism layer formed by curing an active energy ray curable resin composition, for example, an active energy ray curable resin composition is introduced into a prism type, The active energy ray-curable resin composition is sandwiched between the primer layer side of the substrate film with a primer layer (particularly, the polyester film) and the active energy ray is irradiated to cure the resin composition and remove the prism type. By this, the method of forming the prism layer formed by hardening | curing an active energy ray curable resin composition on a base film is mentioned.

  The application method of the active energy ray-curable resin composition is not particularly limited, and for example, spray, shower, dipping, roll, spin, curtain, flow, slit, die, gravure, comma, dispenser, Examples include wet coating methods such as screen printing and ink jet printing.

  As active energy rays, for example, rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays, electromagnetic waves such as X rays and γ rays, electron beams, proton rays, neutron rays, etc. can be used. Curing by ultraviolet irradiation is advantageous from the standpoint of availability of the device and price.

As a method of curing by ultraviolet irradiation, using a high pressure mercury lamp that emits light in a wavelength range of 150 to 450 nm, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a chemical lamp, an electrodeless discharge lamp, an LED, etc. What is necessary is just to irradiate about 30-3,000 mJ / cm < ² >.
After the ultraviolet irradiation, heating can be performed as necessary to complete the curing.

  The thickness of the prism layer is preferably 5 to 50 μm, particularly 10 to 45 μm, more preferably 15 to 40 μm, and particularly preferably 20 to 35 μm.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to the following examples, unless the summary is exceeded. In the following, “parts” and “%” are based on mass.
The measuring method of each physical property value regarding the polyester resin is as follows.

(1) Determination method of unsaturated group content The unsaturated group content (mmol / g) was determined by the following formula (Ia).
Unsaturated group content (mmol / g) = P1 ′ _m / (P1 ′ _mw × S1 ′) Formula (Ia)
In formula (Ia), P1 ′ _m is the mass (mg) of PEGMA, P1 ′ _mw is the average molecular weight (g / mol) of PEGMA (calculated from the hydroxyl value), and S1 ′ is the unsaturated group-containing polyester resin obtained. The solid content mass (g). The PEGMA means “polyethylene glycol monoacrylate used in the reaction”.

(2) Acid value measurement method The acid value (mgKOH / g) is obtained by dissolving 1 g of a polyester resin in 30 g of a mixed solvent of toluene / methanol = 7/3 (volume ratio) and performing neutralization titration based on JIS K0070. It was.
In addition, in this invention, the acid value of a polyester-type resin originates in content of the carboxyl group in resin.

(3) Peak top molecular weight and weight average molecular weight The peak top molecular weight and weight average molecular weight were measured using a column (TSKgel SuperMultipore HZ-M (exclusion limit molecular weight: 2 ×) by high performance liquid chromatography (“HLC-8320GPC” manufactured by Tosoh Corporation). 10 ⁶ , Theoretical plate number: 16,000 plate / line, Filler material: Styrene-divinylbenzene copolymer, Filler particle size: 4 μm) were measured in series and determined by standard polystyrene molecular weight conversion.

[Production Example 1]
[Production of polyester resin (A1)]
In a reaction vessel equipped with a thermometer, a stirrer, a rectifying column, and a nitrogen introduction tube, 305.6 parts (1.839 mol) of isophthalic acid (IPA) as a polyvalent carboxylic acid component, and diethylene glycol (DEG) 185. as a polyol component. 4 parts (1.747 mol), 28.7 parts (0.276 mol) of neopentyl glycol (NPG), and 0.3 parts of tetrabutyl titanate as a catalyst were charged over 90 minutes until the internal temperature reached 200 to 270 ° C. The temperature was raised and an esterification reaction was carried out at 270 ° C. for 3 hours.

  Next, 533.8 parts of methyl ethyl ketone was added while lowering the internal temperature to 80 ° C., and when the resin was completely dissolved, 80.2 parts (0.368 mol) of pyromellitic anhydride (PMAn), and 2.7 triethylamine as a catalyst. Part was added and an addition reaction was performed for 1.5 hours to obtain a 50% solids solution of a polyester resin (A1) having an acid anhydride structure at the molecular end of the main chain. Table 1 shows the physical properties of the polyester resin (A1).

[Production Example 2]
[Production of polyester resin (A2)]
In a reaction vessel equipped with a thermometer, a stirrer, a rectifying column, and a nitrogen introduction tube, 343.5 parts (2.068 mol) of isophthalic acid (IPA) as a polyvalent carboxylic acid component, and diethylene glycol (DEG) 175. 5 parts (1.654 mol), neopentyl glycol (NPG) 53.8 parts (0.517 mol), and tetrabutyl titanate 0.3 part as a catalyst were charged, and it took 90 minutes until the internal temperature reached 200 to 270 ° C. The temperature was raised and an esterification reaction was carried out at 270 ° C. for 3 hours.

  Next, 525.6 parts of methyl ethyl ketone was added while lowering the internal temperature to 80 ° C., and when the resin was completely dissolved, 27.1 parts (0.125 mol) of pyromellitic anhydride (PMAn) and 2.7 triethylamine as a catalyst were used. The addition reaction was carried out for 1.5 hours to obtain a 50% solids solution of a polyester resin (A2) having an acid anhydride structure at the molecular end of the main chain. Table 1 shows the physical properties of the polyester resin (A2).

[Example 1]
[Production of unsaturated group-containing polyester resin 1]
200 parts of a 50% solids polyester resin (A1) solution obtained in Production Example 1, 35.8 parts of polyethylene glycol monoacrylate (PEGMA-1, average molecular weight calculated from hydroxyl value: 540), triethylamine 0 as a catalyst 7 parts were charged into a reactor and subjected to an addition reaction at 80 ° C. for 3 hours to obtain a 58% solution of an unsaturated group-containing polyester resin 1 having an acryloyl group at the molecular end of the main chain. The physical properties of the unsaturated group-containing polyester resin 1 are shown in Table 1.

[Preparation of unsaturated group-containing polyester resin 1 aqueous dispersion]
Charge 34.5 parts of the unsaturated group-containing polyester-based resin 1 solution obtained above, 34.5 parts of deionized water, 63.5 parts of deionized water, and 2 parts of 25% aqueous ammonia to the reactor and stir at room temperature with stirring. An unsaturated group-containing polyester resin 1 aqueous liquid (aqueous dispersion) having a solid content concentration of 20% was prepared by dispersing.

(Preparation of primer composition)
As shown in Table 2, the unsaturated group-containing polyester resin 1 aqueous liquid (aqueous dispersion) and the carbodiimide crosslinking agent “Carbodilite V-04” (manufactured by Nisshinbo Chemical Co., Ltd.) Were mixed so that the unsaturated group-containing polyester-based resin 1: 70.0 and carbodiimide-based crosslinking agent: 30.0, and stirred at room temperature for 1 hour to prepare a primer composition.

[Example 2]

[Production of unsaturated group-containing polyester resin 2]
200 parts of a 50% solids polyester resin (A1) solution obtained in Production Example 1, 23.4 parts of polyethylene glycol monoacrylate (PEGMA-2, average molecular weight calculated from hydroxyl value: 350), triethylamine 0 as a catalyst .6 parts were charged into a reactor and subjected to an addition reaction at 80 ° C. for 3 hours to obtain a 55% solution of unsaturated group-containing polyester resin 2 having an acryloyl group at the molecular end of the main chain. Table 1 shows the physical properties of the unsaturated group-containing polyester resin 2.

[Preparation of unsaturated group-containing polyester resin 2 aqueous dispersion]
Charge 36.4 parts of the unsaturated group-containing polyester-based resin 2 solution 55% solid content obtained above, 61.6 parts of deionized water, and 2 parts of 25% ammonia water to the reactor, An unsaturated group-containing polyester resin 2 aqueous liquid (aqueous dispersion) having a solid content concentration of 20% was prepared by dispersing.

(Preparation of primer composition)
As shown in Table 2, the unsaturated group-containing polyester resin 2 aqueous liquid (aqueous dispersion) and the carbodiimide-based crosslinking agent “Carbodilite V-04” (manufactured by Nisshinbo Chemical Co., Ltd.) Were mixed so as to be unsaturated group-containing polyester resin 2: 70.0 and carbodiimide-based crosslinking agent: 30.0, and stirred at room temperature for 1 hour to prepare a primer composition.

[Example 3]
[Production of unsaturated group-containing polyester resin 3]
200 parts of a 50% solids polyester resin (A2) solution obtained in Production Example 2, 4.3 parts of polyethylene glycol monoacrylate (PEGMA-1, average molecular weight calculated from hydroxyl value: 540), triethylamine 0 as a catalyst .7 parts were charged into a reactor and subjected to an addition reaction at 80 ° C. for 3 hours to obtain a 51% solution of unsaturated group-containing polyester resin 3 having an acryloyl group at the molecular end of the main chain. Table 1 shows the physical properties of the unsaturated group-containing polyester resin 3.

[Preparation of unsaturated group-containing polyester resin 3 aqueous dispersion]
The reactor was charged with 39.3 parts of the unsaturated group-containing polyester-based resin 3 solution 51% obtained above, 59.9 parts of deionized water, and 0.8 part of 25% aqueous ammonia, and stirred at room temperature. Then, the mixture was dispersed in water to prepare an unsaturated group-containing polyester resin 3 aqueous liquid (aqueous dispersion) having a solid content concentration of 20%.

(Preparation of primer composition)
As shown in Table 2, the unsaturated group-containing polyester resin 3 aqueous liquid (aqueous dispersion) and the carbodiimide-based crosslinking agent “Carbodilite V-04” (manufactured by Nisshinbo Chemical Co., Ltd.) Were mixed so as to be unsaturated group-containing polyester resin 3: 70.0 and carbodiimide-based crosslinking agent: 30.0, and stirred at room temperature for 1 hour to prepare a primer composition.

[Comparative Example 1]
[Preparation of polyester resin (A1) aqueous dispersion]
40 parts of a polyester resin (A1) solution having a solid content of 50% obtained in Production Example 1, 56 parts of deionized water, and 4 parts of 25% aqueous ammonia are charged into a reactor and dispersed in water with stirring at room temperature. A polyester resin (A1) aqueous liquid (aqueous dispersion) having a partial concentration of 20% was prepared.

(Preparation of primer composition)
As shown in Table 2, the unsaturated group-containing polyester resin (A1) aqueous liquid (aqueous dispersion) and carbodiimide-based crosslinking agent “Carbodilite V-04” (manufactured by Nisshinbo Chemical Co., Ltd.) The primer composition was prepared by mixing so that a mass ratio might become unsaturated group containing polyester-type resin (A1): 70.0, carbodiimide type crosslinking agent: 30.0, and stirring at room temperature for 1 hour.

[Comparative Example 2]
(Preparation of primer composition)
Table 2 shows the unsaturated group-containing polyester resin (A1) obtained in the above aqueous solution (aqueous dispersion), carbodiimide crosslinking agent “Carbodilite V-04” (manufactured by Nisshinbo Chemical Co., Ltd.), and PEGMA-1. Are mixed so that the mass ratio of the solid content is unsaturated group-containing polyester resin (A1): 51.5, carbodiimide crosslinking agent: 30.0, PEGMA-1: 18.5, and stirred at room temperature for 1 hour. Thus, a primer composition was prepared.

[Comparative Example 3]
(Preparation of primer composition)
Table 2 shows the unsaturated group-containing polyester resin (A1) aqueous liquid (aqueous dispersion), carbodiimide crosslinking agent “Carbodilite V-04” (manufactured by Nisshinbo Chemical Co., Ltd.), and PEGMA-2 obtained above. Are mixed so that the solid content mass ratio is unsaturated group-containing polyester resin (A1): 56.7, carbodiimide crosslinking agent: 30.0, PEGMA-1: 13.3, and stirred at room temperature for 1 hour. Thus, a primer composition was prepared.

[Adhesion evaluation]
Each primer composition prepared in the above Examples and Comparative Examples was diluted with deionized water so that the solid content was 3% to prepare a primer composition coating solution. The prepared coating liquid was placed on a PET film “Lumirror T60” (manufactured by Toray Industries, Inc., thickness 100 μm) with a bar coater No. The primer layer was formed by applying at 6 and drying at 150 ° C. for 3 minutes.

Next, a solvent-free ultraviolet curable resin composition “Sun Rad A” (manufactured by Sanyo Chemical Industries) for forming a prism layer is applied onto the primer layer using an applicator, and subsequently, a height of 13 cm from the coating surface is applied. The ultraviolet curable resin composition was cured by irradiating ultraviolet rays at 400 mJ / cm ² using a high-pressure mercury lamp having an irradiation intensity of 80 W / cm set in this way, and a resin layer having a thickness of 25 μm was formed.

100 pieces of 1 mm ² crosscuts were put in the ultraviolet curable resin layer formed in this way, and cello tape (registered trademark) manufactured by Nichiban Co., Ltd. was applied thereon, and the tape was rubbed with a plastic eraser and adhered sufficiently. Then, it peeled rapidly in 90 degree direction, the peeling degree of the ultraviolet curable resin layer, ie, the number of remaining ultraviolet curable resin layers per 100 crosscuts, was counted, and adhesiveness evaluation was performed on the following reference | standard.

(Evaluation criteria) (Remaining number / Measured number)
A: 100/100
○: 80/100 or more, 99/100 or less Δ: 51/100 or more, 79/100 or less ×: 50/100 or less

  From the result of Table 2, since the primer layer formed from the primer composition of Examples 1 to 3 contains the unsaturated group-containing polyester resin of the present invention, both the base film and the coating layer It was found that the adhesion was excellent.

  On the other hand, since the polyester resin used in Comparative Example 1 does not contain an unsaturated group, it has poor adhesion. Moreover, in Comparative Examples 2 and 3, although containing a compound having an unsaturated group, since the unsaturated group is not bonded to the polyester resin, the effect of the unsaturated group does not appear, and the adhesiveness It was inferior to.

  The primer composition obtained from the unsaturated group-containing polyester resin of the present invention can be suitably used as a primer for a substrate film. Moreover, the obtained base film with a primer layer is excellent in adhesiveness with a coating layer formed by curing an active energy ray-curable resin composition, for example, a label sheet, a printing sheet, a hard coat film, It is useful as a sheet formed by providing a coating layer on a film, such as a prism sheet, and particularly useful as a prism sheet.

Claims (18)

  An unsaturated group-containing polyester resin having a carboxyl group in a side chain of the main chain and an unsaturated group in at least one of the molecular ends of at least one of the side chain of the main chain and the main chain .   The unsaturated group-containing polyester resin according to claim 1, wherein the unsaturated group has at least one molecular end of the main chain.   The unsaturated group-containing polyester resin according to claim 1 or 2, wherein the unsaturated group content is 0.005 to 3 mmol / g.   The unsaturated group-containing polyester resin according to any one of claims 1 to 3, wherein the unsaturated group is a (meth) acryloyl group.   An acid value is 1.5-150 mgKOH / g, The unsaturated group containing polyester resin of any one of Claims 1-4 characterized by the above-mentioned.   The unsaturated group-containing polyester resin according to any one of claims 1 to 5, wherein the weight average molecular weight is 5,000 to 100,000.   It is obtained by reacting a polyester-based resin (A) having an acid anhydride structure at at least one molecular end of the main chain with an unsaturated group-containing compound (B) having a functional group capable of reacting with an acid anhydride. The unsaturated group-containing polyester resin according to any one of claims 1 to 6.   The unsaturated group-containing polyester resin according to claim 7, wherein the unsaturated group-containing compound (B) having a functional group capable of reacting with the acid anhydride is a polyalkylene glycol mono (meth) acrylate. .   An aqueous liquid, wherein the unsaturated group-containing polyester resin according to any one of claims 1 to 8 is dissolved or dispersed in an aqueous solvent.   A primer composition comprising the unsaturated group-containing polyester resin according to any one of claims 1 to 8.   The primer composition according to claim 10, further comprising a crosslinking agent.   The primer composition according to claim 11, wherein the crosslinking agent is at least one compound selected from the group consisting of an isocyanate compound and a carbodiimide compound.   The content of unsaturated groups of the unsaturated group-containing polyester resin in the primer composition is 0.003 to 1 mmol / g, according to any one of claims 10 to 12, Primer composition.   The content ratio of the unsaturated group-containing polyester resin and the crosslinking agent is 99/1 to 30/70 as the mass of the unsaturated group-containing polyester resin / the mass of the crosslinking agent. The primer composition according to any one of ˜13.   An aqueous liquid, wherein the primer composition according to any one of claims 10 to 14 is dissolved or dispersed in an aqueous solvent.   It has a primer layer which consists of a primer composition of any one of Claims 10-14 on a base film, The base film with a primer layer characterized by the above-mentioned.   The prism sheet which has a prism layer on the primer layer of the base film with a primer layer of Claim 16.   The prism sheet according to claim 17, wherein the prism layer is a cured product of a solventless active energy ray-curable resin composition.