JP2009007544A - Polyester resin and pressure-sensitive adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive composition that can form an adhesive agent layer excellent in tack, adhesion with a substrate, heat resistance, resistance to moist heat and transparency, and to provide a laminate formed by using the pressure-sensitive adhesive composition. <P>SOLUTION: Provided is a polyester resin that is obtained by the reaction of a dibasic acid type component (A) containing a dibasic acid type component (a1) having an aromatic ring and/or alicyclic ring structure, a carboxyl group-free diol (B) containing a diol (b1) which has an alkyl group and does not have an carboxyl group on the side chain, and a dioxycarboxylic acid (C) having two hydroxyl groups and one or more carboxyl groups in one molecule, and that has a glass transition temperature of -80°C to 0°C. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polyester resin that can be used in a pressure-sensitive adhesive composition excellent in adhesiveness, heat resistance, moist heat resistance and transparency with various adherends, and particularly suitable for laminating optical members. The present invention relates to a pressure-sensitive adhesive composition containing the polyester resin and a laminate formed using the pressure-sensitive adhesive composition.

  Due to dramatic advances in electronics in recent years, various flat panel displays (FPD) such as liquid crystal display (LCD), plasma display (PDP), rear projection display (RPJ), EL display, light emitting diode display, etc. It has come to be used as a display device in various fields. For example, these FPDs are not only used indoors, including personal computer displays and liquid crystal televisions, but are also used in vehicles such as car navigation displays.

  A polarizing film and a retardation film are laminated on the liquid crystal cell member constituting the LCD.

  Also, these display devices use an antireflection film for preventing reflection from an external light source, a protective film (protection film) for preventing scratches on the surface of the display device, and the like.

  In addition to using the FPD as a display device, a touch panel function may be provided on the surface of the FPD to be used as an input device. A protective film, an antireflection film, an ITO vapor deposition resin film, and the like are also used for this touch panel.

  Various films used in the display device are used by being attached to an adherend with a pressure-sensitive adhesive. Since it is used for a display device, the pressure-sensitive adhesive is first required to be excellent in transparency. Therefore, a pressure-sensitive adhesive mainly composed of an acrylic resin is generally used.

  By the way, among the various films described above, the polarizing film has a three-layer structure in which both surfaces of a polyvinyl alcohol polarizer are sandwiched between triacetyl cellulose-based and cycloolefin-based protective films. Because of the characteristics of the materials that make up each layer, the polarizing film undergoes significant dimensional changes due to expansion and contraction due to heat and humidity.

  In recent years, from the viewpoint of effective use of light in the bonding process of an optical member, suppression of interface reflection based on a difference in refractive index between the optical member and the adherend is required, and the refractive index of the optical member. It is known that the use of a pressure-sensitive adhesive layer (hereinafter sometimes abbreviated as “adhesive layer”) having a refractive index intermediate between the refractive index of the substrate and the adherend is advantageous. Incidentally, if the refractive index difference at the interface is large, the incident angle causing total reflection becomes small, and the effective utilization of light is lowered.

  However, the refractive index of the adhesive layer using the conventional acrylic resin is around 1.46, whereas the refractive index of the material forming the optical member is, for example, around 1.52 for glass, methacrylic resin 1.51 for polycarbonate resin, 1.54 for polyethylene terephthalate (PET) resin, and there is a large difference in refractive index between them. When an optical member made of a resin, a polycarbonate resin, or a PET resin is bonded, the above intermediate refractive index cannot be obtained.

  Therefore, the acrylic pressure-sensitive adhesive for sticking the polarizing film to the glass member for a liquid crystal cell is required to suppress the dimensional change of the polarizing film itself and to further increase the refractive index of the adhesive layer.

  For this reason, by making the pressure-sensitive adhesive layer itself hard or increasing the adhesive strength, it is possible to suppress a relatively small dimensional change or a relatively short-term dimensional change. Further, the refractive index can be improved to some extent by using an aromatic ring-containing monomer, an aromatic compound, a compound containing a sulfur atom, or an inorganic compound.

  However, with the recent increase in screen size of liquid crystal panels, the size of the polarizing film has also increased, and the amount of thermal deformation of the polarizing film has increased. When using a conventional pressure-sensitive adhesive, the stress at the time of sticking remaining in the adhesive layer is not sufficiently relaxed, so the adhesive layer cannot sufficiently follow the distortion of the polarizing film, resulting in a large liquid crystal Exposing the panel to high temperatures or high humidity causes discoloration of the polarizing film and a decrease in transparency, or the polarizing film peels off the glass substrate of the large liquid crystal cell, causing stress concentration on the polarizing film, resulting in large liquid crystals. There is a problem that light leakage occurs in the panel or volatile gas is generated.

  Also, the polarizing film changes in dimensions while the liquid crystal panel is used over a long period of time, and the stress is accumulated in the adhesive layer. If the stress continues to accumulate in the adhesive layer, the distribution of the adhesive force between the polarizing film and the liquid crystal cell glass member becomes non-uniform. During long-term use, stress is concentrated especially on the periphery of the polarizing film, and as a result, the periphery of the liquid crystal element is brighter or darker than the center. appear.

  In addition, after laminating a polarizing film on the glass surface for a liquid crystal cell, the polarizing film is peeled off from the glass cell surface in the inspection process for air and dust entrainment in the laminating process. Then, a new polarizing film or the like is pasted again.

  However, generally after lamination, the laminate is stored at a high temperature for a certain period of time to promote adhesion, and then inspected, so that the peel strength becomes too high during that time, and it is difficult to peel off the polarizing film, etc. Adhesive residue may be generated after peeling, and re-peelability is insufficient.

  As described above, the pressure-sensitive adhesive used for laminating a polarizing film on a glass member for a liquid crystal cell has good optical properties (transparency), heat resistance and moist heat resistance, good stress relaxation, refraction. Controllability of the rate, removability, etc. are required. And the same performance is calculated | required also for the pressure sensitive adhesive for laminating | stacking the retardation film and the cover film of various displays.

  Conventionally, various pressure-sensitive adhesives have been proposed for these various requirements.

  For example, various pressure-sensitive adhesives based on acrylic resins are known (see Patent Documents 1 to 5).

  In addition, pressure-sensitive adhesives using polyester and polyurethane in combination with acrylic resins are also known (see Patent Documents 6 to 9).

  However, in general, acrylic resins and polyester resins and polyurethane resins are not compatible with each other, and the transparency is not so much impaired if only a small amount of polyester resin or polyurethane resin is mixed with acrylic resins. When a large amount of polyester resin or polyurethane resin is mixed, the pressure-sensitive adhesive itself is whitened or separated. The pressure-sensitive adhesive for sticking a polarizing film or the like to a glass for a liquid crystal cell is required to have extremely high transparency. And even if it tries to stick a polarizing film etc. to the glass for liquid crystal cells using the above-mentioned poorly compatible pressure sensitive adhesive, the problem that phase separation and fluctuation will occur in the adhesive layer was there.

  By the way, because of good chemical resistance and workability, adhesives other than pressure-sensitive adhesives (hereinafter referred to as fiber coatings, paints, food packaging laminates and metal plates and plastic films) Polyester adhesives have been used in various technical fields such as adhesives). However, in the technical field of pressure-sensitive adhesives, it seems that polyester-based pressure-sensitive adhesives have been studied in the course of training, but practically they have not been studied. Occupied the majority.

  The pressure sensitive adhesive is used to form a pressure sensitive adhesive sheet.

  The basic laminate structure of the pressure-sensitive adhesive sheet is a sheet-like substrate / pressure-sensitive adhesive layer / single-sided pressure-sensitive adhesive sheet such as a release sheet, or a release sheet / pressure-sensitive adhesive layer / sheet-like substrate / pressure-sensitive type. It is a double-sided pressure-sensitive adhesive sheet such as an adhesive layer / release sheet. At the time of use, the release sheet is peeled off, and the pressure-sensitive adhesive layer is attached to the adherend. Pressure-sensitive adhesive is not only the pressure-sensitive adhesive layer has a tack at the moment when the pressure-sensitive adhesive layer touches the adherend during sticking, but it is completely different from the adhesive. It is necessary to have a cohesive force for maintaining the sticking state while having a tack and appropriate hardness without solidifying. The cohesive force greatly depends on the molecular weight.

  Since the acrylic resin is formed by addition polymerization, one having a molecular weight of several hundred thousand or more can be easily formed. On the other hand, since a polyester resin is formed by polycondensation, it is practically impossible to form such a high molecular weight resin. In the case of a polyester resin, if the condensation and decomposition reach an equilibrium state, the molecular weight will no longer increase, and if the reaction conditions are changed and further condensation is attempted, it will compete with deterioration. It is.

  Therefore, in order to develop cohesion while having tack, the main component is an acrylic resin that has a relatively large molecular weight and easily develops cohesion, and a relatively small amount of curing agent is used for the main component. It can be said that an acrylic pressure-sensitive adhesive that easily develops tack is suitable. On the other hand, a polyester resin having a relatively small molecular weight can be said to be suitable as an adhesive for firmly bonding with a relatively large amount of a curing agent to develop adhesive performance.

  In addition, the raw material of the polyester resin is more expensive than the raw material of the acrylic resin. Furthermore, since the polycondensation reaction is a sequential reaction, it takes inevitably a long time to increase the molecular weight as compared to addition polymerization. As a result, the polyester resin is more expensive than the acrylic resin.

  Thus, for many years, polyester resins have been applied to adhesives, and acrylic resins have been applied to pressure sensitive adhesives.

  However, there are various fields where pressure-sensitive adhesive sheets are used, and the required level is increased, new requirements are added, and the conventional acrylic pressure-sensitive adhesives are not fully meeting various requirements. Therefore, application of polyester resins to pressure-sensitive adhesives has been studied.

  For example, a sensitivity obtained by blending various curing agents with a polyester resin having a glass transition temperature (Tg) of −60 to 0 ° C. formed from dimer acid and a glycol component having an alkyl group in a side chain of 30 mol% or more. A pressure-type adhesive is known (see, for example, Patent Document 10). However, when an epoxy resin is used as a curing agent, the reaction requires a relatively high temperature and a long time. On the other hand, Examples 7 and 8 using an isocyanate compound as a curing agent had the same problems as Patent Documents 12 and 13 described later because a polyester resin containing trimellitic anhydride as a main component was used as a main component.

  Also known is a pressure-sensitive adhesive comprising an aliphatic polyester having a repeating unit composed of an ester of a glycol having a methyl group in the side chain and a carboxylic acid linked by a polyisocyanate and having a Tg of -40 ° C or lower. (For example, see Patent Document 11). The pressure-sensitive adhesive disclosed in Patent Document 11 is intended for biodegradability and is an aliphatic polyester pressure-sensitive adhesive, so that it is easy to obtain tack and a relatively flexible pressure-sensitive adhesive layer is obtained. However, the heat resistance is insufficient. For example, when it is used as a pressure-sensitive adhesive for laminating a polarizing film on a glass member for a liquid crystal cell, it floats or peels off when placed for a long time under high temperature or high temperature and high humidity after sticking.

  Also, a polycarboxylic acid component containing an aromatic dicarboxylic acid, a diol component containing a glycol having a hydrocarbon group in the side chain, a trihydric or higher polyhydric alcohol and / or a trivalent or higher polyvalent carboxylic acid are polycondensed. A polyester resin comprising 0.1 to 5 mol% of a structural part derived from a trihydric or higher polyhydric alcohol and / or trihydric or higher polyhydric carboxylic acid. There is known a pressure-sensitive adhesive characterized by containing a resin (for example, see Patent Document 12).

  And a polycondensation of a carboxylic acid component containing 10 mol% or more and less than 50 mol% of an aromatic dicarboxylic acid and a polyhydric alcohol component containing 5 mol% or more of a glycol having a hydrocarbon group in the side chain, and A pressure-sensitive adhesive characterized by containing a polyester-based resin having a number average molecular weight of 5000 or more is known (for example, see Patent Document 13).

  Patent Documents 12 and 13 disclose that a polyester resin is a main ingredient and the cohesive force of a pressure-sensitive adhesive layer is increased by utilizing a reaction between a hydroxyl group and / or a carboxyl group in a polyester resin and a crosslinking agent. ing.

  The hydroxyl group and / or carboxyl group responsible for the reaction with the crosslinking agent is considered to be introduced using a polyfunctional alcohol or a polyfunctional carboxylic acid component. In order to increase the cohesive force of the pressure-sensitive adhesive layer, it is considered necessary to increase these functional groups in the polyester resin. However, since the polyfunctional alcohol and the hydroxyl group and carboxylic acid of the polyfunctional carboxylic acid component are all primary functional groups, they tend to cause three-dimensionalization such as partial aggregation during the esterification reaction, and are easily gelled. It is difficult to obtain a high molecular weight. Therefore, even if we want to increase the functional group to improve the cohesive force, it cannot be increased easily. As expected, the solvent-insoluble fraction (gel fraction) of the pressure-sensitive adhesive layer cannot be increased and the cohesive force is improved. Can not.

  Moreover, even if it does not gel at the time of esterification, these functional groups remaining in the polyester-based resin are primary, so that they are highly reactive with a crosslinking agent. Therefore, when a crosslinking agent is blended with the polyester resin, the workability (pot life) that can be applied is short, so the workability is considerably inferior.

  Furthermore, when applied to an optical film such as a polarizing film or a retardation film, fluctuation (optical interference unevenness) is generated in the formed pressure-sensitive adhesive layer due to partial aggregation or non-uniform density. In addition, after sticking, starting from these partial aggregations, etc., not only causes phenomena such as foaming and misalignment, but also causes adhesive residue after peeling off the polarizing film, etc., and re-peelability is insufficient, Not suitable for pressure sensitive adhesives for attaching optical films.

Patent Documents 14 and 15 disclose examples in which dimethylol alkanoic acid and dimethylol alkyl acid are used for adhesives and pressure-sensitive adhesives. However, in Patent Document 14, dimethylol alkanoic acid is added to a synthetic resin, and when such a low molecular weight acid is added to a pressure-sensitive adhesive, moisture resistance and heat resistance are impaired. In Patent Document 15, an aliphatic dicarboxylic acid, an aliphatic diol, and dimethylolalkanoic acid are subjected to a condensation reaction. However, a pressure-sensitive adhesive composed only of such an aliphatic component is inferior in moisture resistance and heat resistance. .
Japanese Patent Laid-Open No. 01-066283 JP-A-10-279907 JP 2002-121521 A JP 2003-013029 A JP 2002-014225 A JP 2003-073646 A JP 2004-002827 A JP 2004-083648 A JP 2002-053835 A Japanese Patent Laid-Open No. 04-328186 Japanese Patent Laid-Open No. 11-021340 JP 2007-099879 A JP 2007-045914 A JP 2006-45336 A JP 2007-191656 A

  An object of the present invention is to provide a high molecular weight polyester resin that has a high polymerization stability at the time of esterification reaction, contains a large number of functional groups that can be used as crosslinking points, and further contains a crosslinking agent. Polyester pressure-sensitive adhesive that has a long pot life and can form a pressure-sensitive adhesive layer with excellent tack, adhesion to substrates, heat resistance, moist heat resistance and transparency The purpose is to do.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems.

  That is, the first invention is a dibasic acid component (A) containing a dibasic acid component (a1) having an aromatic ring and / or an alicyclic structure, having an alkyl group in the side chain, and having a carboxyl group. Glass transition obtained by reaction of a diol (B) having no carboxyl group, and a dioxycarboxylic acid (C) having two hydroxyl groups and one or more carboxyl groups in one molecule The present invention relates to a polyester resin having a temperature of −80 to 0 ° C.

  Moreover, 2nd invention is related with the polyester resin of 1st invention characterized by containing 5-50 mol% of structures derived from the dibasic-acid type component (a1) which has an aromatic ring and / or an alicyclic structure.

  The third invention is the polyester resin of the first or second invention, characterized in that it contains 5 to 40 mol% of a structure derived from the diol (b1) having an alkyl group in the side chain and no carboxyl group. About.

  The fourth invention relates to the polyester resin according to any one of the first to third inventions, which contains 0.1 to 10 mol% of a structure derived from dioxycarboxylic acid (C).

  The fifth invention is characterized in that the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2.0 to 6.0. It relates to the polyester resin of the invention.

  The sixth invention relates to the polyester resin according to any one of the first to fifth inventions, which has a weight average molecular weight of 30,000 to 1,000,000.

  The seventh invention relates to the polyester resin according to any one of the first to sixth inventions, wherein the total of the acid value and the hydroxyl value is from 0.1 to 30 mgKOH / g.

  An eighth invention relates to a pressure-sensitive adhesive composition comprising the polyester resin of any one of the first to seventh inventions and a reactive compound (E) capable of reacting with the polyester resin.

  In the ninth invention, the reactive compound (E) is selected from the group consisting of a polyfunctional epoxy compound, a polyfunctional aziridine compound, a polyfunctional carbodiimide compound, a polyfunctional oxazoline compound, a polyfunctional isocyanate compound, and a metal chelate compound. It is related with the pressure-sensitive-type adhesive composition of 8th invention characterized by being at least 1 type.

  The tenth invention relates to a laminate in which an optical member is laminated on a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the eighth or ninth invention.

  The eleventh invention is a liquid crystal cell member in which a glass member for a liquid crystal cell, a pressure sensitive adhesive layer formed from the pressure sensitive adhesive composition of the eighth or ninth invention, and an optical member are sequentially laminated. About.

  According to the present invention, it becomes possible to stably obtain a high-molecular weight polyester containing a large number of functional groups that can be used as crosslinking points and having good reproducibility. A polyester-based pressure-sensitive adhesive that can form a pressure-sensitive adhesive layer excellent in tack, adhesion to a substrate, heat resistance, moist heat resistance, and transparency can be obtained.

  The polyester resin of the present invention having a glass transition temperature of −80 to 0 ° C. includes a dibasic acid component (A) including a dibasic acid component (a1) having an aromatic ring and / or an alicyclic structure, and a side chain. A diol (B) having no alkyl group, including a diol (b1) having an alkyl group and having no carboxyl group, and a dioxycarboxylic acid having two hydroxyl groups and one or more carboxyl groups in one molecule (C) can be obtained by polycondensation reaction.

Examples of the dibasic acid component (A) used in the present invention include known dicarboxylic acids and their acid anhydrides, and esterified products of dicarboxylic acids and acid anhydrides with monoalcohols such as methanol and ethanol. The dibasic acid component (A1) having an aromatic ring and / or alicyclic structure is included in the dibasic acid component (A). Examples of the dibasic acid component (a1) having an aromatic ring and / or alicyclic structure include o-phthalic acid, isophthalic acid, terephthalic acid, 1,4-dimethylterephthalic acid, 1,3-dimethylisophthalic acid, 5-sulfo-1,3-dimethylisophthalic acid, 4,4-biphenyldicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, norbornene dicarboxylic acid, diphenylmethane-4,4′-dicarboxylic acid, Aromatic dicarboxylic acids such as phenylindanedicarboxylic acid;
Aromatic dicarboxylic anhydrides such as phthalic anhydride, 1,8-naphthalenedicarboxylic anhydride, 2,3-naphthalenedicarboxylic anhydride;
Alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid;
Examples include alicyclic dicarboxylic anhydrides such as hexahydrophthalic anhydride, 3-methyl-hexahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride, 1,2-cyclohexanedicarboxylic anhydride, and the like.

  Moreover, the compound which esterified the above aromatic dicarboxylic acids and aromatic dicarboxylic acid anhydrides by lower alcohol, for example, esterified product of C1-C4 alkyl alcohol, can also be used. When an esterified product of an aromatic dicarboxylic acid or aromatic dicarboxylic acid anhydride with a lower alcohol is used, it is not a dehydration condensation with the diol (B) or dioxycarboxylic acid (C), but a transesterification by dealcoholization, An ester bond is formed.

  Furthermore, a compound obtained by half-esterifying an aromatic tricarboxylic acid anhydride or an aromatic tetracarboxylic acid anhydride with a monoalcohol can be used as the aromatic dicarboxylic acid.

  Examples of the aromatic tricarboxylic acid anhydride include 1,2,3-benzenetricarboxylic acid anhydride, trimellitic acid anhydride, 1,2,4-naphthalene tricarboxylic acid anhydride, and 1,4,5-naphthalene tricarboxylic acid. Anhydride, 2,3,6-naphthalene tricarboxylic acid anhydride, 1,2,8-naphthalene tricarboxylic acid anhydride, 3,4,4′-benzophenone tricarboxylic acid anhydride, 3,4,4′-biphenyl ether tricarboxylic acid Acid anhydride, 3,4,4′-biphenyltricarboxylic acid anhydride, 2,3,2′-biphenyltricarboxylic acid anhydride, 3,4,4′-biphenylmethanetricarboxylic acid anhydride, 3,4,4 ′ -Biphenyl sulfone tricarboxylic acid anhydride etc. are mentioned.

Examples of the aromatic tetracarboxylic anhydride include pyromellitic anhydride, ethylene glycol ditrimellitic anhydride ester, propylene glycol ditrimellitic anhydride ester, butylene glycol ditrimellitic anhydride ester, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid anhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic acid anhydride, 1,4,5,8-naphthalene tetracarboxylic acid anhydride, 2,3,6 , 7-Naphthalenetetracarboxylic acid anhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic acid anhydride, 3,3 ′, 4,4′-dimethyldiphenylsilane tetracarboxylic acid anhydride, 3,3 ', 4,4'-tetraphenylsilanetetracarboxylic anhydride, 1,2,3,4-furantetracarboxylic anhydride, 4,4 '-Bis (3,4-dicarboxyphenoxy) diphenyl sulfide anhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone anhydride, 4,4'-bis (3,4-dicarboxy) Phenoxy) diphenylpropane anhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic anhydride, bis (phthalic acid) phenyl Phosphine oxide anhydride, p-phenylene-bis (triphenylphthalic acid) anhydride, m-phenylene-bis (triphenylphthalic acid) anhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether anhydride, Bis (triphenylphthalic acid) -4,4′-diphenylmethane anhydride, 9,9-bis (3,4-dicarboxyphenyl) fluorene Anhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) phenyl] fluorenic anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic anhydride Products, 3,4-dicarboxy-1,2,3,4-tetrahydro-6-methyl-1-naphthalene succinic anhydride and the like.
Examples of the monoalcohol include methanol, ethanol, propanol, isopropanol, butanol, n-amyl alcohol, hexanol, heptanol, n-octanol, 2-ethylhexanol, isooctanol, nonanol, decanol, isoundecanol, lauryl alcohol, Linear or branched aliphatic alcohols such as cetyl alcohol and stearyl alcohol;
Araliphatic monoalcohols such as benzyl alcohol, α-methylbenzyl alcohol, phenethyl alcohol;
Examples include alicyclic monoalcohols such as cyclopentanol, cyclohexanol, cyclohexanemethanol, cycloheptanol, cyclooctanol, and tricyclodecane methanol.

  These dibasic acid components (a1) can be used alone or in combination of two or more. Among these, terephthalic acid and isophthalic acid are preferable from the viewpoint of heat resistance and wet heat resistance.

Examples of the dibasic acid component (A) other than the dibasic acid component (a1) having an aromatic ring and / or alicyclic structure include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, and azelaic acid. Aliphatic dicarboxylic acids such as suberic acid, maleic acid, chloromaleic acid, fumaric acid, dodecanedioic acid, pimelic acid, citraconic acid, glutaric acid, itaconic acid;
Succinic anhydride, methyl succinic anhydride, 2,2-dimethyl succinic anhydride, butyl succinic anhydride, isobutyl succinic anhydride, hexyl succinic anhydride, octyl succinic anhydride, dodecenyl succinic anhydride, phenyl succinic anhydride, anhydrous Glutaric acid, 3-allyl glutaric anhydride, 2,4-dimethyl glutaric anhydride, 2,4-diethyl glutaric anhydride, butyl glutaric anhydride, hexyl glutaric anhydride, maleic anhydride, 2-methyl maleic anhydride, 2 , 3-dimethylmaleic anhydride, butylmaleic anhydride, pentylmaleic anhydride, hexylmaleic anhydride, octylmaleic anhydride, decylmaleic anhydride, dodecylmaleic anhydride, 2,3-dichloromaleic anhydride, phenylmaleic anhydride Acid, 2,3-diphenylmaleic anhydride, itaco anhydride Acid, citraconic anhydride, phthalic anhydride, 4-methylphthalic anhydride, dimer acid, 1,2,3,6-tetrahydrophthalic anhydride, 3-methyl-1,2,3,6-tetrahydrophthalic anhydride, 4-methyl-1,2,3,6-tetrahydrophthalic anhydride, 3-methyl-1,2,3,6-tetrahydrophthalic anhydride, 4-methyl-1,2,3,6-tetrahydrophthalic anhydride Methylbutenyl-1,2,3,6-tetrahydrophthalic anhydride, chlorendic anhydride, head acid anhydride, biphenyldicarboxylic anhydride, hymic anhydride, endomethylene-1,2,3,6-tetrahydrophthalic anhydride, Methyl-3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride, methylcyclohex Njikarubon anhydride, trimellitic anhydride, 1,8-naphthalene dicarboxylic acid anhydride, acid anhydrides such as octahydro-1,3-dioxo-4,5-isobenzofurandione carboxylic acid anhydrides.

  These dicarboxylic acids, their acid anhydrides, or esterified compounds thereof may be used alone or in combination of two or more. In some cases, a trifunctional or higher functional carboxylic acid compound such as trimellitic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, or the anhydride thereof can be used in combination.

  It is important that the dibasic acid component (A) includes a dibasic acid component (a1) having an aromatic ring and / or an alicyclic structure, and the dibasic acid component is contained in the polyester resin of the present invention. It is preferable to contain 5 to 50 mol% of the structure derived from the component (a1), and containing 10 to 35 mol% is most preferable because a polyester resin excellent in adhesiveness, heat resistance, moist heat resistance and transparency can be obtained. . When the structure derived from the dibasic acid component (a1) is less than 5 mol% or more than 50 mol%, the adhesion property balance of the polyester resin to be obtained (especially compatibility between tack and cohesive force) should be ensured. May be difficult, and heat resistance and moist heat resistance may decrease.

Next, as the diol (B) having no carboxyl group used in the present invention, for example, ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, 2-methyl-1,3-propanediol, 2- Methyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-butyl-2-methyl-1 , 3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-methyl-2 , 4-pentanediol, 1,3,5-trimethyl-1,3-pentanediol, 2-methyl-1,8-oct Diol, 3,3'-dimethylol heptane, polyoxyethylene glycol (addition mole number 10 or less), polyoxypropylene glycol (addition mole number 10 or less), propanediol, 1,3-butanediol, 1,4-butane Diol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, octanediol, 3-butyl-3-ethyl-1,5-pentanediol, 2-ethyl-1 Aliphatic or alicyclic diols such as 1,6-hexanediol, cyclohexanediol, cyclohexanedimethanol, tricyclodecane dimethanol, cyclopentadiene dimethanol, dimer diol;
1,3-bis (2-hydroxyethoxy) benzene, 1,2-bis (2-hydroxyethoxy) benzene, 1,4-bis (2-hydroxyethoxy) benzene, 4,4′-methylenediphenol, 4, 4 ′-(2-norbornylidene) diphenol, 4,4′-dihydroxybiphenol, o-, m-, and p-dihydroxybenzene, 4,4′-isopropylidenephenol, 1,2-indanediol, 1,3 -Naphthalenediol, 1,5-naphthalenediol, 1,7-naphthalenediol, 9,9'-bis (4-hydroxyphenyl) fluorene, 9,9'-bis (3-methyl-4-hydroxyphenyl) fluorene or Bisphenols such as bisphenol A and bisphenol F and ethylene oxide, propylene oxide, etc. And aromatic diols such as bisphenol, etc., etc. made by adding sharp emission oxide.

  These diols (B) may be used alone or in combination of two or more.

  The diol (B) in the present invention has an alkyl group in the side chain and does not have a carboxyl group in order to suppress crystallization and ensure an adhesive property balance (particularly, compatibility between tack and cohesive force). It is important to contain diol (b1), and it is preferable to contain 5-40 mol% of structures derived from diol (b1) in the polyester resin of this invention. If the structure derived from the diol (b1) is less than 5 mol% or more than 40 mol%, it is difficult to maintain the adhesive property balance (particularly, compatibility between tack and cohesive force) of the obtained polyester resin. In some cases, heat resistance and moist heat resistance may decrease.

  Although it does not specifically limit as diol (b1) which has an alkyl group in a side chain, and does not have a carboxyl group, For example, neopentyl glycol, 3-methyl-1,5-pentanediol in the diol (B) mentioned above 2-methyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1, 3-propanediol, 2-butyl-2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-2,4-pentanediol, 2,4- Diethyl-1,5-pentanediol, 3-butyl-3-ethyl-1,5-pentanediol, 1,3,5-trimethyl-1,3-pentanediol, 2-methyl 1,6-hexanediol, 2-methyl-1,8-octanediol and the like, these may be used alone, or two or more.

  As the dioxycarboxylic acid (C) having two hydroxyl groups and one or more carboxyl groups in one molecule used in the present invention, known oxyacids can be preferably used.

As the known dioxycarboxylic acid (C) used in the present invention, for example, dihydroxyfumaric acid, dihydroxymaleic acid, 2,2-bis (hydroxymethyl) ethanoic acid (also known as dimethylolacetic acid), 2,3- Dihydroxypropanoic acid (also known as glyceric acid), 2,2-bis (hydroxymethyl) propanoic acid (also known as 2,2-dimethylolpropionic acid), 3,3-bis (hydroxymethyl) propanoic acid (also known as 3, 3-dimethylolpropionic acid), 2,3-dihydroxy-2-methylpropanoic acid, 2,2-bis (hydroxymethyl) butanoic acid (also known as dimethylolbutyric acid), 2,2-dihydroxybutanoic acid, 2,3- Dihydroxybutanoic acid, 2,4-dihydroxybutanoic acid (also known as 3-deoxytetronic acid), 3,4-dihydroxybutanoic acid Acid, 2,4-dihydroxy-3,3-dimethylbutanoic acid, 2,3-dihydroxy-2-methylbutanoic acid, 2,3-dihydroxy-2-ethylbutanoic acid, 2,3-dihydroxy-2-isopropylbutanoic acid, 2,3-dihydroxy-2-butylbutanoic acid, (R) -2,4-dihydroxy-3,3-dimethylbutanoic acid (also known as bantoic acid), 2,3-dihydroxybutanedioic acid (also known as tartaric acid), 2 , 2-bis (hydroxymethyl) pentanoic acid (also known as dimethylolvaleric acid), 3,5-dihydroxy-3-methylpentanoic acid (also known as mevalonic acid), 2,2-bis (hydroxymethyl) hexanoic acid (also known as Dimethylol caproic acid), 2,2-bis (hydroxymethyl) heptanoic acid (also known as dimethylol enanthate), 3,5-dihydroxyhept Acid, 2,2-bis (hydroxymethyl) octanoic acid (also known as dimethylolcaprylic acid), 2,2-bis (hydroxymethyl) nonanoic acid (also known as dimethylolberargonic acid), 2,2-bis ( Hydroxymethyl) decanoic acid (also known as dimethylol capric acid), 2,2-bis (hydroxymethyl) dodecanoic acid (also known as dimethylol lauric acid), 2,2-bis (hydroxymethyl) tetradecanoic acid (also known as dimethylol) Myristic acid), 2,2-bis (hydroxymethyl) pentadecanoic acid, 2,2-bis (hydroxymethyl) hexadecanoic acid (also known as dimethylol palmitic acid), 2,2-bis (hydroxymethyl) heptadecanoic acid (also known as, Dimethylol margaric acid), 2,2-bis (hydroxymethyl) octadecanoic acid (also known as dimethylol) Lstearic acid), dimethylol oleic acid, dimethylol linoleic acid, dimethylol linolenic acid, dimethylol aracodonic acid, dimethylol docosahexaenoic acid, aliphatic dioxycarboxylic acids such as dimethylol eicosapentaenoic acid;
2,3-dihydroxybenzoic acid (also known as o-pyrocatechuic acid), 2,4-dihydroxybenzoic acid (also known as β-resorcinic acid), 2,5-dihydroxybenzoic acid (also known as gentisic acid), 2,6- Dihydroxybenzoic acid (also known as γ-resorcinic acid), 3,4-dihydroxybenzoic acid (also known as protocatechuic acid), 3,5-dihydroxybenzoic acid (also known as α-resorcinic acid), 2,6-dihydroxy-4- Methylbenzoic acid, 2,4-dihydroxy-6-methylbenzoic acid (also known as o-orceric acid), 3,5-dihydroxy-4-methylbenzoic acid, 2,4-dihydroxy-3,6-dimethylbenzoic acid, 2,3-dihydroxy-4-methoxybenzoic acid, 3,4-dihydroxy-5-methoxybenzoic acid, 2,4-di (hydroxymethyl) benzoic acid, 3,4-di Hydroxymethyl) benzoic acid, 4-bromo-3,5-dihydroxybenzoic acid, 5-bromo-2,4-dihydroxybenzoic acid, 3-chloro-2,6-dihydroxybenzoic acid, 5-chloro-2,4- Dihydroxybenzoic acid, hydroxy (4-hydroxy-3-methoxyphenyl) acetic acid (also known as vanylmandelic acid), D, L-3,4-dihydroxymandelic acid, 2,5-dihydroxyphenylacetic acid (also known as homogentisic acid), 3 , 4-Dihydroxyphenylacetic acid (also known as homoprotocatechuic acid), 3,4- (methylenedioxy) phenylacetic acid, 3- (3,4-dihydroxyphenyl) propanoic acid (also known as hydrocaffeic acid), 3- (2, 4-dihydroxyphenyl) acrylic acid (also known as umbelic acid), 3- (3,4-dihydroxyphenyl) actyl Formic acid (also known as caffeic acid), 4,4′-bis (p-hydroxyphenyl) pentanoic acid, 3- (3,4-methylenedioxyphenyl) propionic acid, 2,2-bis (hydroxymethyl) butyric acid, 2,4-dihydroxycinnamic acid, 2,5-dihydroxy cinnamic acid, cinnamyl-3,4-dihydroxy-α-cyanocinnamic acid, 2-bromo-4,5-methylenedioxycinnamic acid, 3,4-methylenedi Oxycinnamic acid, 4,5-methylenedioxy-2-nitrocinnamic acid, 2,6-dihydroxyisonicotinic acid, DL-3,4-dihydroxymandelic acid, 1,4-dihydroxy-2-naphthalenecarboxylic acid, 3 , 5-Dihydroxy-2-naphthalenecarboxylic acid, 3,7-dihydroxy-2-naphthalenecarboxylic acid, 4,8-dihydroxyquinoline-2-carboxylic acid (also known as Xanthurenic acid) 3- (3,4-dihydroxyphenyl) propionic acid, 2,4-dihydroxypyrimidine-5-carboxylic acid, 2,6-dihydroxypyridine-4-carboxylic acid (also known as citrazic acid), 2,4- Dihydroxythiazole-5-acetic acid, 2- (1-thienyl) ethyl-3,4-dihydroxybenzylidene cyanoacetic acid, dipropionic acid-6-estradiol, 2,5-dihydroxy-1,4-benzenediacetic acid, (2R, 3R) -2,3-dihydroxy-3- (phenylcarbamoyl) propionic acid and the like aromatic ring or hetero ring-containing dioxycarboxylic acids.

  In addition, when it has an aromatic ring, what does not directly bond two hydroxyl groups to an aromatic ring is preferable.

  The known dioxycarboxylic acids (C) used in the present invention can be used alone or in combination of two or more.

  Since the dioxycarboxylic acid (C) has two hydroxyl groups, it is polycondensed with the dibasic acid component (A) as an OH component in the same manner as the diol (B) having no carboxyl group, and the polyester of the present invention. Resin is produced. And the carboxyl group derived from dioxycarboxylic acid (C) turns into a carboxyl group of the side chain of a polyester resin.

  It is preferable that the two hydroxyl groups in the dioxycarboxylic acid (C) are both primary in that they are rich in activity during the esterification reaction. On the other hand, if the dioxycarboxylic acid (C) functions as a COOH component during the esterification reaction, it is likely to react three-dimensionally during the reaction, and gelation is likely to occur, or a polyester resin is obtained without gelation. It is easy to partially aggregate. Therefore, in the esterification reaction, the dioxycarboxylic acid (C) functions exclusively as an OH component and does not function as a COOH component. It is preferable that it is tertiary. Since the activity of the esterification reaction is low, the dioxycarboxylic acid (C) can have one or more secondary or tertiary carboxyl groups in one molecule. However, depending on the case, a polyester resin having a branched structure can be obtained by esterifying a part or all of the carboxyl groups in the dioxycarboxylic acid (C). This reaction is possible by adjusting the reaction conditions such as increasing the reaction temperature, adding a catalyst, and reacting under reduced pressure.

  Here, the reaction process of the polyester resin of the present invention will be described in detail. First, the dibasic acid component (A), the diol (B) having no carboxyl group, and the dioxycarboxylic acid (C) are esterified by a predetermined dehydration reaction to obtain an intermediate (d). . At this point, the hydroxyl group of the dioxycarboxylic acid (C) mainly reacts and the carboxyl group hardly reacts and remains in the side chain. Accordingly, the intermediate (d) is linear, has a relatively small molecular weight, and a small Mw / Mn ratio. Even when the intermediate (d) is used as a pressure-sensitive adhesive, its cohesive force is weak and impractical. Subsequently, when the intermediate (d) is subjected to a reduced pressure reaction under a vacuum of 5 torr or less, both terminal hydroxyl groups of the intermediate (d) are removed by the deglycolization reaction, and further the esterification reaction increases the molecular weight. A polyester resin (D1) having a cohesive force necessary for the pressure-sensitive adhesive can be obtained. Even if the molecular weight of the polyester resin (D1) increases, the shape thereof is linear. Preferably, in addition to the deglycolization reaction of the hydroxyl group, the side chain carboxyl group derived from the dioxycarboxylic acid (C) and the hydroxyl group derived from the intermediate (d) are preferably adjusted by adjusting the reaction conditions during the reduced pressure reaction. The esterification reaction is gradually advanced to obtain a polyester resin (D2) having a branched structure. By forming the branched structure, the Mw / Mn ratio increases, the number of terminal hydroxyl groups increases, and the functional groups that can be used as crosslinking points can be increased. That is, by using dioxycarboxylic acid (C), it is possible to obtain a polyester having a high molecular weight and high crosslinkability. The polyester resins (D1) and (D2) are both polyester resins of the present invention.

  On the other hand, when a polyfunctional alcohol or a polyfunctional carboxylic acid component as disclosed in Patent Documents 12 and 13 is used, since both are primary functional groups, a branched structure has already been taken during the dehydration reaction, When this is reacted under reduced pressure, all the hydroxyl groups undergo deglycolization at the same time, so the high molecular weight is very fast and gelation is likely. Therefore, when polyfunctional alcohol or polyfunctional carboxylic acid is used, a method is used in which a relatively small amount is used to increase the molecular weight or a relatively large amount is used to decrease the molecular weight. Thus, the methods disclosed in Patent Documents 12 and 13 cannot satisfy both high molecular weight and crosslinkability.

  As described above, the polybasic condensation of the dibasic acid component (A), the diol (B) having no carboxyl group, and the dioxycarboxylic acid (C) makes it difficult to partially aggregate and is rich in uniformity. A polyester resin exhibiting good fluidity can be obtained. Furthermore, when the reactive compound (E) described later is blended with such a polyester resin, a pressure-sensitive adhesive having a relatively long pot life that can form a pressure-sensitive adhesive layer rich in cohesion after curing can be obtained. .

  It is preferable that the polyester resin of this invention contains 0.1-10 mol% of structures derived from dioxycarboxylic acid (C). That is, the amount of the carboxyl group introduced into the side chain and / or the amount of the hydroxyl group when a branched structure is introduced depends on the structure derived from the dioxycarboxylic acid (C). The amount of the carboxyl group introduced into the side chain and / or the hydroxyl group in the case of introducing a branched structure is crosslinked with a reactive compound (E) described later to form a pressure-sensitive adhesive layer. Contributes to improvement of heat resistance and moist heat resistance. However, when there are too many carboxyl groups and / or hydroxyl groups introduced by dioxycarboxylic acid (C), the pot life is shortened. Therefore, from the balance between the pot life as the pressure-sensitive adhesive and the performance of the pressure-sensitive adhesive layer, the structure derived from dioxycarboxylic acid (C) is 0.1 to 10 mol% in the polyester resin. preferable.

  When the polyester resin of the present invention is formed by the polycondensation reaction of the dibasic acid component (A), the diol (B) and the dioxycarboxylic acid (C), the reaction proceeds even without a catalyst, but the reaction is made smoother. In order to make it progress, a catalyst can also be used suitably. Catalysts used include ammonia, amines, quaternary ammonium salts, quaternary phosphonium salts, alkali metal hydroxides, alkaline earth metal hydroxides, Lewis acids, tin, lead, titanium, iron, zinc, zirconium , Organometallic compounds containing cobalt and the like, metal halides and the like.

  Examples of amines include triethylamine, pyridine, aniline, morpholine, N-methylmorpholine, pyrrolidine, piperidine, N-methylpiperidine, cyclohexylamine, n-butylamine, dimethyloxazoline, imidazole, N-methylimidazole, N, N- Examples thereof include dimethylethanolamine, N, N-diethylethanolamine, N, N-dimethylisopropanolamine, N-methyldiethanolamine and the like.

  Examples of the quaternary ammonium salts include tetramethylammonium bromide, tetramethylammonium chloride, tetramethylammonium fluoride trihydrate, tetramethylammonium hexafluorophosphate, tetramethylammonium hydrogen phthalate, tetramethylammonium hydroxide pentahydrate. , Tetramethylammonium hydroxide, tetramethylammonium iodide, tetramethylammonium nitrate, tetramethylammonium perchlorate, tetramethylammonium tetrafluoroborate, tetramethylammonium tribromide, phenyltrimethylammonium bromide, tetraethylammonium bromide, tetraethylammonium chloride Tetraethylammonium fluoride trihydrate, tetraethylammonium hydroxide, tetraethylammonium iodide, tetraethylammonium perchlorate, tetraethylammonium tetrafluoroborate, tetraethylammonium-p-toluenesulfonate, tetrapropylammonium bromide, tetrapropylammonium chloride, tetra Propylammonium iodide, tetrapropylammonium hydroxide, tetrapropylammonium perchlorate, tetra-n-propylammonium hydrogensulfate, tetra-n-propylammonium pearlate (VII), tetrabutylammonium bromide, tetrabutylammonium trichloride bromide, Trabutylammonium chloride, tetrabutylammonium iodide, tetrabutylammonium hydroxide, tetrabutylammonium hexafluorophosphate, tetrabutylammonium hydrogensulfate, tetrabutylammonium nitrate, tetrabutylammonium tetrahydroborate, tetrabutylammonium tetrafluoroborate, Tetrabutylammonium cyanotrihydroborate, tetrabutylammonium difluorotriphenylstannate, tetrabutylammonium fluoride trihydrate, tetrabutylammonium tetrathiophenate (IV), tetrabutylammonium fluoride hydrate, tetra-n-butyl Ammonium dihydrogen trifluoride, Tetra-n-butylammonium trifluoromethanesulfonate, tributylammonium bis (2,3-dimercapto-2-butenedinylolylate-S, S ′) nicolate, tetra-n-heptylammonium bromide, tetra-n-heptylammonium chloride, Tetra-n-heptylammonium iodide, tetra-n-hexylammonium benzoate, tetra-n-hexylammonium bromide, tetra-n-hexylammonium chloride, tetra-n-hexylammonium iodide, tetra-n-hexylammonium perchlorate , Tetraoctyl ammonium bromide, tetraoctadecyl ammonium bromide and the like.

Quaternary phosphonium salts include, for example, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, ethyltriphenylphosphonium bromide, ethyltriphenylphosphonium iodide, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, tetrabutylphosphonium tetrafluoroborate, Tetrabutylphosphonium hexafluorophosphate, tetrabutylphosphonium tetraphenylborate, tetrabutylphosphonium benzotriazolate, tetrabutylphosphonium bis (1,2-benzenedithiolate) nicolate (III), tetrabutylphosphonium bis (4-methyl-1) , 2-Benzenedithiolate) Nicolate (III), Tetrabutylphospho Umubisu (4,5-mercapto-1,3-dithiol-2 thionating -S ^4, S ⁵⁾ Nikoreto (III) and the like.

Examples of the alkali metal or alkaline earth metal hydroxide include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide;
Alkaline earth metal hydroxides such as magnesium hydroxide, calcium hydroxide, strontium hydroxide and barium hydroxide;
Can be mentioned.

  Examples of the organic tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, Examples thereof include tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, and tin 2-ethylhexanoate.

  Examples of organic zirconium compounds include zirconium acetate, zirconium benzoate, zirconium naphthenate, and the like.

  Examples of the organic titanium compounds include dibutyltitanium dichloride, tetrabutyltitanate, tetrabutoxytitanate, tetraethyltitanate, tetraisopropyltitanate, butoxytitanium trichloride, and the like.

  Examples of the organic lead compounds include lead acetate, lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate.

  Examples of organic iron compounds include iron 2-ethylhexanoate and iron acetylacetonate.

  Examples of the organic cobalt compounds include cobalt acetate, cobalt benzoate, and cobalt 2-ethylhexanoate.

  Examples of the organic zinc compounds include zinc acetate, zinc oxalate, zinc naphthenate, and zinc 2-ethylhexanoate.

  Examples of metal halides include stannous chloride, stannous bromide, stannous iodide, and the like.

  Furthermore, Lewis acids such as boron trifluoride, manganese acetate, germanium oxide, antimony trioxide, aluminum trichloride, zinc chloride, and titanium chloride are exemplified, but not limited thereto. A catalyst may use only 1 type or may use 2 or more types together. The catalyst is used in an amount of 10 parts by weight or less with respect to 100 parts by weight of all reaction components. The range of 0.0001 to 1 part by weight is more preferable. When the amount exceeds 10 parts by weight, there is a disadvantage that the product is colored or a catalyst that has not been deactivated remains and acts as a negative catalyst to cause a decomposition reaction.

  The polyester resin of the present invention can be produced according to a conventionally known polyester reaction method. For example, it can be obtained by the following method.

  The dibasic acid component (A), the diol (B), and the dioxycarboxylic acid (C) are subjected to a dehydration reaction or a transesterification reaction at 160 to 260 ° C., preferably 180 to 250 ° C., and then a reduced pressure of 5 Torr or less. It is heated to 180 to 280 ° C., preferably 200 to 260 ° C. in the lower state to perform a deglycolization reaction, and after cooling, it is prepared by adding an organic solvent so as to have a predetermined nonvolatile content.

  The dioxycarboxylic acid (C) may be charged into the reaction vessel from the beginning together with the dibasic acid component (A) and the diol (B), or the dibasic acid component (A) and the diol. The reaction may be carried out in addition to the dehydration reaction or transesterification reaction of (B).

  Incidentally, when the polymerization temperature is less than the above lower limit, the reaction does not proceed sufficiently. On the other hand, if the polymerization temperature exceeds the upper limit, side reactions such as decomposition may occur or coloring may be easily caused. The reaction time can usually be about 1 to 60 hours.

  The polyester resin of the present invention has a glass transition temperature (Tg) of −80 to 0 ° C. so that it can exhibit well-balanced adhesive properties (particularly, both tack and cohesive force) as a pressure-sensitive adhesive layer. Thus, what is necessary is just to select each component of a dibasic acid type component (A), a diol (B), and a dioxycarboxylic acid (C) suitably, and the glass transition temperature (Tg) of a polyester resin is -60--10. It is more preferable to select each component so that it becomes ° C.

  When the glass transition temperature of the polyester resin is less than −80 ° C., the cohesive force of the pressure-sensitive adhesive layer obtained by using the polyester resin is lowered, and the peeling off tends to occur. On the other hand, when the glass transition temperature exceeds 0 ° C., the pressure-sensitive adhesive layer becomes too hard and does not exhibit sufficient tack, or the adhesive strength is weak when plastics or a glass plate and a plastic film are laminated. In addition, the solubility in a solvent is reduced, and the viscosity of the pressure-sensitive adhesive is increased, which makes it difficult to handle during coating, which is not preferable.

  The glass transition temperature is a value obtained using a DSC (differential scanning calorimeter).

  The weight average molecular weight (Mw) of the polyester resin in the present invention is preferably in the range of 30,000 to 1,000,000 from the viewpoint of adhesiveness, and more preferably in the range of 50,000 to 500,000. preferable. When such a polyester resin is used, a pressure-sensitive adhesive having excellent adhesion and wettability can be obtained. If the Mw is less than 30,000, the cohesive force as the pressure-sensitive adhesive layer is hardly expressed, and the heat resistance and heat and humidity resistance are reduced. On the other hand, if Mw exceeds 1,000,000, the fluidity of the pressure-sensitive adhesive becomes poor even when diluted with a solvent, and the coating property is reduced when producing a pressure-sensitive adhesive sheet. Absent.

  Further, the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyester resin in the present invention is preferably in the range of 2.0 to 6.0, and is preferably 2.0 to More preferably, it is in the range of 4.0. When Mw / Mn is less than the lower limit, as in the case of Mw, the cohesive force as the pressure-sensitive adhesive layer is hardly expressed, and heat resistance and moist heat resistance tend to decrease. On the other hand, exceeding the upper limit is not preferable because the fluidity of the pressure-sensitive adhesive is lowered even when diluted with a solvent, and the coating property is lowered when a pressure-sensitive adhesive sheet is produced. Usually, in the case of a pressure-sensitive adhesive, unlike the adhesive, it is preferable that the Mw / Mn ratio is 2.0 or more. That is, when Mw / Mn ratio is large and a low molecular weight component is contained to some extent, when producing a pressure-sensitive adhesive sheet, the affinity (wetting) to the sheet-like substrate is improved, and the substrate adhesion is improved. Furthermore, when the formed pressure-sensitive adhesive sheet is adhered to an adherend, the pressure-sensitive adhesive layer in a cured state contains a cured component derived from a low molecular weight component, so that the pressure-sensitive adhesive layer is attached. Adhesion to the body can be improved.

  The total acid value and hydroxyl value of the polyester resin in the present invention is preferably controlled in the range of 0.1 to 30 mgKOH / g, and more preferably in the range of 0.5 to 20 mgKOH / g. When the sum of the acid value and the hydroxyl value is less than 0.1 mgKOH / g, the number of reaction points with the reactive compound (E) described later decreases, and the cohesive force of the formed pressure-sensitive adhesive layer is insufficient. In addition to being difficult to peel off the polarizing film and the like, there are cases where adhesive residue is generated after peeling and the removability is insufficient. On the other hand, if the sum of the acid value and the hydroxyl value exceeds 30 mgKOH / g, the pot life is shortened, and workability at the time of coating or bonding is remarkably lowered.

  The pressure-sensitive adhesive composition of the present invention contains the polyester resin and a reactive compound (E) that can react with the polyester resin. That is, the reactive compound (E) used in the present invention is a compound having in its molecule a functional group capable of reacting with a hydroxyl group and / or a carboxyl group in the polyester resin described above. As the reactive compound (E), a compound (e1) mainly having a functional group capable of reacting with a hydroxyl group in the polyester resin, and a compound (e2) mainly having a functional group capable of reacting with a carboxyl group in the polyester resin. And so on. Examples of the compound (e1) include polyfunctional isocyanate compounds, polyfunctional silane compounds, polyfunctional acid anhydrides, N-methylol group-containing compounds, and melamine compounds. Moreover, as a compound (e2), a polyfunctional epoxy compound, a polyfunctional amine compound, a polyfunctional aziridine compound, a polyfunctional carbodiimide compound, a polyfunctional oxazoline compound, a metal chelate compound etc. are mentioned, for example. In particular, when the acid value of the polyester resin is 1 to 30 mgKOH / g, it is preferable to use the compound (e2), and in particular, an epoxy compound, an aziridine compound, a carbodiimide compound, an oxazoline compound, or a metal chelate compound is more preferably used. It is done. Moreover, when the hydroxyl value of a polyester resin is 1 mg-30 mgKOH / g, it is preferable to use a compound (e1), and especially a polyfunctional isocyanate compound or a polyfunctional silane compound is more preferable. These are preferably used because they have excellent adhesion to the adherend of the pressure-sensitive adhesive layer after the crosslinking reaction and adhesion to the sheet-like substrate.

  Furthermore, it is also one of the preferable forms that the compound (e1) and the compound (e2) are used in combination as the reactive compound (E).

  Examples of the polyfunctional epoxy compound include bisphenol A-epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol. Diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N′-diglycidylaminomethyl) And cyclohexane.

  Examples of the polyfunctional aziridine compound include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxite), N, N′-toluene-2,4-bis (1-aziridinecarboxite), Bisisophthaloyl-1- (2-methylaziridine), tri-1-aziridinylphosphine oxide, N, N′-hexamethylene-1,6-bis (1-aziridinecarboxite), trimethylolpropane-tri -Β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, tris-2,4,6- (1-aziridinyl) -1,3,5-triazine, trimethylolpropane Tris [3- (1-aziridinyl) propionate], trimethylolpropane tris [3- (1-aziridinyl) buty Rate], trimethylolpropane tris [3- (1- (2-methyl) aziridinyl) propionate], trimethylolpropane tris [3- (1-aziridinyl) -2-methylpropionate], 2,2′-bis Hydroxymethylbutanol tris [3- (1-aziridinyl) propionate], pentaerythritol tetra [3- (1-aziridinyl) propionate], diphenylmethane-4,4-bis-N, N′-ethyleneurea, 1,6-hexa And methylenebis-N, N′-ethyleneurea, 2,4,6- (triethyleneimino) -Syn-triazine, bis [1- (2-ethyl) aziridinyl] benzene-1,3-carboxylic acid amide, and the like. It is done.

  As the polyfunctional carbodiimide compound, for example, a compound having two or more carbodiimide groups (—N═C═N—) in the molecule is preferably used, and a known polycarbodiimide can be used.

  Moreover, as a polyfunctional carbodiimide compound, the high molecular weight polycarbodiimide produced | generated by carrying out the decarboxylation condensation reaction of diisocyanate in presence of a carbodiimidization catalyst can also be used. Examples of such compounds include those obtained by subjecting the following diisocyanates to a decarboxylation condensation reaction.

  As the diisocyanate, 4,4′-diphenylmethane diisocyanate, 3,3′-dimethoxy-4,4′-diphenylmethane diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, 4,4′-diphenyl ether diisocyanate, 3,3′-dimethyl-4,4′-diphenyl ether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, isophorone diisocyanate, 4,4′- One of dicyclohexylmethane diisocyanate, tetramethylxylylene diisocyanate, or a mixture thereof can be used.

  As the carbodiimidization catalyst, 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, 1-ethyl-3-methyl-2-phospholene-1-oxide, 1-ethyl- Phosphorene oxides such as 2-phospholene-1-oxide or their 3-phospholene isomers can be used.

  Examples of such polyfunctional carbodiimide compounds include the Carbodilite series manufactured by Nisshinbo Industries, Ltd. Among these, Carbodilite V-01, 03, 05, 07, and 09 are preferable because of excellent compatibility with organic solvents.

  As the polyfunctional oxazoline compound, a compound having two or more oxazoline groups in the molecule is preferably used. Specifically, 2′-methylenebis (2-oxazoline), 2,2′-ethylenebis (2-oxazoline) is used. 2,2′-ethylenebis (4-methyl-2-oxazoline), 2,2′-propylenebis (2-oxazoline), 2,2′-tetramethylenebis (2-oxazoline), 2,2′- Hexamethylene bis (2-oxazoline), 2,2′-octamethylene bis (2-oxazoline), 2,2′-p-phenylene bis (2-oxazoline), 2,2′-p-phenylene bis (4 4'-dimethyl-2-oxazoline), 2,2'-p-phenylenebis (4-methyl-2-oxazoline), 2,2'-p-phenylenebis (4-phenyl) Lu-2-oxazoline), 2,2'-m-phenylenebis (2-oxazoline), 2,2'-m-phenylenebis (4-methyl-2-oxazoline), 2,2'-m-phenylenebis (4,4′-dimethyl-2-oxazoline), 2,2′-m-phenylenebis (4-phenylenebis-2-oxazoline), 2,2′-o-phenylenebis (2-oxazoline), 2, 2'-o-phenylenebis (4-methyl-2-oxazoline), 2,2'-bis (2-oxazoline), 2,2'-bis (4-methyl-2-oxazoline), 2,2'- Bis (4-ethyl-2-oxazoline), 2,2′-bis (4-phenyl-2-oxazoline) and the like can be mentioned. Alternatively, vinyl monomers such as 2-isopropenyl-2-oxazoline and 2-isopropenyl-4,4-dimethyl-2-oxazoline and other monomers that can be copolymerized with these vinyl monomers. It may be a copolymer with a monomer.

  Examples of the polyfunctional isocyanate compound include aromatic polyisocyanate, aliphatic polyisocyanate, araliphatic polyisocyanate, and alicyclic polyisocyanate.

  Examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6 -Tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4 ', Examples thereof include 4 "-triphenylmethane triisocyanate.

  Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HMDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, and dodeca. Examples include methylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate.

  Examples of the araliphatic polyisocyanate include ω, ω′-diisocyanate-1,3-dimethylbenzene, ω, ω′-diisocyanate-1,4-dimethylbenzene, ω, ω′-diisocyanate-1,4-diethylbenzene. 1,4-tetramethylxylylene diisocyanate, 1,3-tetramethylxylylene diisocyanate, and the like.

  Examples of the alicyclic polyisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, Examples thereof include methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), 1,4-bis (isocyanatomethyl) cyclohexane and the like.

  Moreover, the trimethylol propane adduct body of the said polyisocyanate, the trimer which has an isocyanurate ring, etc. can be used. Furthermore, polyphenylmethane polyisocyanate (PAPI), naphthylene diisocyanate, and these polyisocyanate modified products can be used. As the polyisocyanate-modified product, a carbodiimide group, a uretdione group, a uretoimine group, a burette group reacted with water, a group selected from isocyanurate groups, or a modified product having two or more of these groups can be used. . A reaction product of polyol and diisocyanate can also be used as the polyfunctional isocyanate compound.

  Among these polyfunctional isocyanate compounds, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (also known as isophorone diisocyanate), xylylene diisocyanate, 4,4 The use of a non-yellowing or hard yellowing polyisocyanate compound such as' -methylenebis (cyclohexylisocyanate) (also known as hydrogenated MDI) is particularly preferred from the viewpoint of weather resistance, heat resistance or heat and humidity resistance.

  When a polyfunctional isocyanate compound is used as the reactive compound (E), a known catalyst can be used as necessary to accelerate the reaction. For example, a tertiary amine compound, an organometallic compound, etc. are mentioned, and it is possible to use a single compound or plural compounds.

  Examples of the metal chelate compound include compounds in which a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium is coordinated to acetylacetone or ethyl acetoacetate. Can be mentioned.

Examples of the polyfunctional silane compound include a silane coupling agent. Examples of the silane coupling agent include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltributoxysilane, γ-methacryloxypropylmethyldimethoxysilane, and γ-methacryloxypropyl. A silane compound having two methacryloxy groups such as methyldiethoxysilane, an alkyl group and an alkoxy group;
a silane compound having two acryloxy groups, an alkyl group and an alkoxy group, such as γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, and γ-acryloxypropylmethyldimethoxysilane;
Silane compounds having three (meth) acryloxyalkyl groups and three alkoxy groups such as γ-methacryloxymethyltrimethoxysilane and γ-acryloxymethyltrimethoxysilane;
Alkoxysilanes having a vinyl group such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinylmethyldimethoxysilane;
Alkoxysilanes having an alkyl group such as 5-hexenyltrimethoxysilane, 9-decenyltrimethoxysilane, styryltrimethoxysilane;
Silanes having aminoalkyl groups and alkoxy groups such as γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane;
γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, β-mercaptomethylphenylethyltrimethoxysilane, mercaptomethyltrimethoxysilane, 6 A compound having a mercapto group such as mercaptohexyltrimethoxysilane, 10-mercaptodecyltrimethoxysilane;
Tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane;
3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane , Phenyltrimethoxysilane, hexamethylsilazane, diphenyldimethoxysilane, 1,3,5-tris (3-trimethoxysilylpropyl) isocyanurate, vinyltris (2-methoxyethoxy) silane, N- (2-aminoethyl)- Examples include 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane.

  Examples of the N-methylol group-containing compound include amino resins and phenol resins, and examples thereof include addition compounds of partial compounds such as urea, melamine, benzoguanamine, phenol, cresols, bisphenols and formaldehyde, or partial condensates thereof.

  The polyfunctional acid anhydride is a compound having two or more carboxylic acid anhydride groups and is not particularly limited, but includes tetracarboxylic dianhydride, hexacarboxylic dianhydride, hexacarboxylic dianhydride, And maleic anhydride copolymer resin. In addition, polycarboxylic acids, polycarboxylic acid esters, polycarboxylic acid half esters, and the like that can be converted into anhydrides through a dehydration reaction during the reaction are included in the polyfunctional acid anhydrides referred to in the present invention.

  More specifically, as tetracarboxylic dianhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, oxydiphthalic dianhydride, diphenyl sulfone tetracarboxylic dianhydride, Diphenyl sulfide tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, perylene tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, "Ricacid TMTA-C", "Ricacid MTA-" manufactured by Shin Nippon Chemical Co., Ltd. 10 ”,“ Licacid MTA-15 ”,“ Licacid TMEG series ”,“ Licacid TDA ”, and the like.

  These reactive compounds (E) may be used alone or in combination.

  The pressure-sensitive adhesive composition of the present invention preferably contains 0.001 to 20 parts by weight of the reactive compound (E), preferably 0.01 to 10 parts by weight, based on 100 parts by weight of the polyester resin. Is more preferable. When the amount of the reactive compound (E) used exceeds 20 parts by weight, the adhesiveness of the resulting pressure-sensitive adhesive composition tends to decrease, the cohesive strength of the resin layer is low, and stability and durability during repeated use. It is inferior in property and is not preferable. On the other hand, when the amount is less than 0.001 part by weight, a sufficient cross-linked structure cannot be obtained, so that the cohesive force tends to be reduced, and the heat resistance and heat-and-moisture resistance tend to be reduced.

  The resin composition is three-dimensionally cross-linked by the reaction of the hydroxyl group or carboxyl group in the polyester resin with the reactive functional group in the reactive compound (E), and only ensures adhesion to various substrates and adherends. In addition, since heat resistance and heat-and-moisture resistance under severer conditions than before can be improved, it can be preferably used for optical members.

  In the pressure-sensitive adhesive composition of the present invention, various resins, coupling agents, softeners, dyes, pigments, antioxidants, ultraviolet absorbers, weathering stabilizers, as long as the effects of the present invention are not impaired. , Tackifier, plasticizer, filler, anti-aging agent and the like may be blended.

  By using the pressure-sensitive adhesive composition of the present invention, a laminated product (hereinafter referred to as “adhesive sheet”) composed of an adhesive layer and a sheet-like substrate can be obtained.

  For example, an adhesive sheet can be obtained by coating, drying and curing the pressure-sensitive adhesive composition of the present invention on various sheet-like substrates.

  When applying a pressure-sensitive adhesive composition, an appropriate liquid medium, for example, a hydrocarbon solvent such as toluene, xylene, hexane or heptane; an ester solvent such as ethyl acetate or butyl acetate; a ketone such as acetone or methyl ethyl ketone Viscosity can be adjusted by adding organic solvents such as halogenated hydrocarbon solvents such as dichloromethane and chloroform; ether solvents such as diethyl ether, methoxytoluene and dioxane, and other hydrocarbon solvents. In addition, the pressure-sensitive adhesive composition can be heated to reduce the viscosity. However, a solvent containing a hydroxyl group cannot be used.

  Examples of the sheet-like base material include cellophane, various plastic sheets, rubber, foam, cloth, rubber cloth, resin-impregnated cloth, glass plate, metal plate, wood and the like in a flat shape. Various base materials can be used alone or in a multi-layered state in which a plurality of base materials are laminated. Further, the surface can be peeled off.

  Various plastic sheets are also called various plastic films, such as polyvinyl alcohol film, triacetyl cellulose film, polypropylene, polyethylene, polycycloolefin, polyolefin resin film such as ethylene-vinyl acetate copolymer, polyethylene terephthalate, polybutylene terephthalate. , Polyester resin film such as polyethylene naphthalate, Polycarbonate resin film, Polynorbornene resin film, Polyarylate resin film, Acrylic resin film, Polyphenylene sulfide resin film, Polystyrene resin film, Vinyl Resin film, polyamide resin film, polyimide resin film, epoxy resin film, etc. And the like.

  When the pressure-sensitive adhesive composition contains a liquid medium such as an organic solvent or water after the pressure-sensitive adhesive composition is applied to the sheet-like base material by an appropriate method according to a conventional method, the liquid medium If the pressure-sensitive adhesive composition does not contain a liquid medium that should be volatilized, the adhesive layer in the molten state is cooled and solidified, and pressure-sensitive adhesive is applied to the sheet-like substrate. An agent layer can be formed.

  The thickness of the pressure-sensitive adhesive layer is preferably 0.1 μm to 200 μm, and more preferably 1 μm to 100 μm. If the thickness is less than 0.1 μm, sufficient adhesive strength may not be obtained, and if the thickness exceeds 200 μm, characteristics such as adhesive strength are often not improved further.

  The method for applying the pressure-sensitive adhesive composition of the present invention to a sheet-like substrate is not particularly limited, and may be a Meyer bar, applicator, brush, spray, roller, gravure coater, die coater, lip coater, comma coater, Various coating methods such as a knife coater, a reverse coater, and a spin coater can be used.

  There is no particular limitation on the drying method, and examples include those using hot air drying, infrared rays or a reduced pressure method. As drying conditions, although it depends on the cured form of the adhesive composition, the film thickness, and the selected solvent, heating with hot air at about 60 to 180 ° C. is usually sufficient.

  The laminate of the present invention is a so-called sheet (also referred to as “film” as described above) optical member having various optical properties such as a polarizing film, a retardation film, an elliptically polarizing film, an antireflection film, and a brightness enhancement film. And a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention. On the other surface of the pressure-sensitive adhesive layer, a sheet-like base material subjected to a release treatment can be laminated.

  In the laminate of the present invention, (a) the pressure-sensitive adhesive composition is applied to the release-treated surface of the release-treated sheet-like substrate and dried, and the sheet-like optical member is applied to the surface of the pressure-sensitive adhesive layer. Or (i) coating a sheet-like optical member with a pressure-sensitive adhesive composition, drying, and laminating the release-treated surface of the sheet-like substrate that has been peel-treated on the surface of the pressure-sensitive adhesive layer Can be obtained.

  By peeling off the release-treated sheet-like substrate covering the surface of the pressure-sensitive adhesive layer from the laminate thus obtained, for example, by sticking the pressure-sensitive adhesive layer to the glass member for liquid crystal cells A liquid crystal cell member having a configuration of “sheet-like optical member / pressure-sensitive adhesive layer / glass member for liquid crystal cell” can be obtained.

  Since the pressure-sensitive adhesive of the present invention is composed of a polyester resin, it has improved adhesion to a substrate, has excellent plasticizer resistance and low-temperature adhesion, and adheres to a substrate such as a foam. It is also preferably used for applications that require safety. In particular, when an aromatic ring is contained in the main chain skeleton, the refractive index after drying and / or curing of the pressure-sensitive adhesive composition can maintain 1.45 or more. As described above, the refractive index of the material used for the optical member such as the optical member film or glass is about 1.50 to 1.58, and the pressure-sensitive adhesive composition is dried and dried. If the refractive index after curing is less than 1.45, the difference in refractive index between the optical film and the optical member increases. Therefore, for example, when an adhesive layer obtained from the pressure-sensitive adhesive composition is provided on a film light guide plate which is a kind of optical film, total reflection occurs at a shallow angle, and effective use of light is achieved. May decrease. Moreover, in order to reduce the refractive index difference from the optical film or optical member, the refractive index after drying and / or curing of the pressure-sensitive adhesive composition of the present invention is controlled in the range of 1.49 to 1.60. What you can do is also important. In particular, control is possible in the range of 1.50 to 1.55.

  Specific examples of the present invention will be described below together with comparative examples, but the present invention is not limited to the following examples. In the following examples and comparative examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively, unless otherwise specified.

[Synthesis of polyester resin]
(Synthesis Example 1)
A dibasic acid component (A), a diol (B), and dioxy are added to a polymerization tank and a dropping device of a polymerization reactor equipped with a polymerization tank, a stirrer, a thermometer, a water separator, a reflux condenser, and a nitrogen introduction tube. Carboxylic acid (C) was charged at the following ratio.

[Polymerization tank]
Sebacic acid (A) 40.4 parts Isophthalic acid (a1) 49.8 parts 1,4-butanediol (B) 14.8 parts 1,6-hexanediol (B) 13.0 parts Neopentyl glycol (b1) 22.9 parts 2,2-bis (hydroxymethyl) butanoic acid (C) 8.1 parts

  After the air in the polymerization tank was replaced with nitrogen gas, the temperature was raised to 160 ° C. in a nitrogen atmosphere while stirring. After confirming dehydration at 160 ° C., the temperature was gradually raised to 240 ° C. over about 8 hours to conduct dehydration reaction. Next, when the acid value became 15 or less, the temperature was lowered to 150 ° C., 0.02 part of tetrabutyl titanate was added as a catalyst, and the pressure was gradually reduced while raising the temperature, and 3-5 torr, 240 ° C. for 5 hours. When the reaction was carried out and the molecular weight was reached, the reaction was terminated by dissolving in a toluene / ethyl acetate mixed solution (weight ratio = 1/3). This reaction solution is light yellow and transparent, has a non-volatile content of 50.1%, a viscosity of 4,000 mPa · s, an acid value of the polyester resin of 5.5 mgKOH / g, a hydroxyl value of 1.2 mgKOH / g, a glass transition temperature of −40 ° C. The weight average molecular weight (Mw) was 80,000, and Mw / Mn = 2.96.

(Synthesis Example 2)
A dibasic acid component (A) and a diol (B) are respectively added to a polymerization tank and a dropping device of a polymerization reactor equipped with a polymerization tank, a stirrer, a thermometer, a water separator, a reflux condenser, and a nitrogen introduction tube. The ratio was charged.

[Polymerization tank]
Sebacic acid (A) 40.4 parts Isophthalic acid (a1) 49.8 parts 1,4-butanediol (B) 14.8 parts 1,6-hexanediol (B) 13.0 parts Neopentyl glycol (b1) 22.9 parts

  After the air in the polymerization tank was replaced with nitrogen gas, a dehydration reaction was performed in the same manner as in Synthesis Example 1. Next, when the acid value became 15 or less, the mixture was gradually cooled, and when it reached 150 ° C., 8.1 parts of 2,2-bis (hydroxymethyl) butanoic acid (C) was added, and tetrabutyl titanate as a catalyst. While adding 0.02 part, the pressure was gradually reduced while raising the temperature to 240 ° C., and the reaction was carried out at 3 to 5 torr and 240 ° C. for 5 hours. When the molecular weight was reached, the reaction was terminated by dissolving in a toluene / ethyl acetate mixed solution (weight ratio = 1/3).

  This reaction solution is light yellow and transparent with a non-volatile content of 50.2% and a viscosity of 4,100 mPa · s. The acid value of the polyester resin is 5.2 mgKOH / g, the hydroxyl value is 1.5 mgKOH / g, the glass transition temperature is −40 ° C. The weight average molecular weight (Mw) was 76,000, and Mw / Mn was 3.04.

(Synthesis Example 3)
A dibasic acid component (A), a diol (B), and dioxy are added to a polymerization tank and a dropping device of a polymerization reactor equipped with a polymerization tank, a stirrer, a thermometer, a water separator, a reflux condenser, and a nitrogen introduction tube. Carboxylic acid (C) was charged at the same ratio as in Synthesis Example 1.

  After replacing the air in the polymerization tank with nitrogen gas, 0.02 part of tetrabutyl titanate was added, the temperature was increased in a nitrogen atmosphere while stirring, and the esterification reaction was performed by heating at 150 to 240 ° C. for 2.5 hours. Went. Next, the pressure was gradually reduced to 4 Torr after 0.5 hours, and the reaction was further continued for 1.5 hours while continuing to reduce the pressure. When the molecular weight reached a predetermined value, a toluene / ethyl acetate mixed solution (weight ratio = 1/3) was added. Dissolve to complete the reaction.

  This reaction solution is light yellow and transparent, has a nonvolatile content of 50.3%, a viscosity of 3,900 mPa · s, an acid value of the polyester resin of 5.8 mgKOH / g, a hydroxyl value of 1.3 mgKOH / g, a glass transition temperature of −40 ° C., The weight average molecular weight (Mw) was 75,000, and Mw / Mn = 3.13.

(Synthesis Example 4)
Instead of (A), (B), and (C) used in Synthesis Example 1, the reaction was conducted in the same manner as in Synthesis Example 1 except that the following ratios were used.

[Polymerization tank]
Dimer acid (A) 84.0 parts Dimethylterephthalic acid (a1) 29.1 parts Dimethylisophthalic acid (a1) 34.9 parts Ethylene glycol (B) 18.6 parts 2-Butyl-2-ethyl-1,3- Propanediol (b1) 48.0 parts 2,2-bis (hydroxymethyl) butanoic acid (C) 8.1 parts

  After cooling, it was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a solution of a polyester resin having a clear brown color, a non-volatile content of 49.6%, and a viscosity of 3,200 mPa · s. The polyester resin had an acid value of 6.2 mgKOH / g, a hydroxyl value of 2.3 mgKOH / g, a glass transition temperature of −20 ° C., a weight average molecular weight (Mw) of 65,000, and Mw / Mn = 2.71.

(Synthesis Example 5)
In the same manner as in Synthesis Example 1 except that 38.0 parts of 2-butyl-2-ethyl-1,3-propanediol was used instead of neopentyl glycol used as (b1) in Synthesis Example 1, toluene was reacted. A solution of a polyester resin having a light yellow and transparent, non-volatile content of 50.0% and a viscosity of 4,500 mPa · s was obtained by dissolving in a solution of ethyl acetate / ethyl acetate (weight ratio = 1/3). The polyester resin had an acid value of 5.9 mgKOH / g, a hydroxyl value of 2.2 mgKOH / g, a glass transition temperature of −45 ° C., a weight average molecular weight (Mw) of 85,000, and Mw / Mn = 3.40.

(Synthesis Example 6)
The same as Synthesis Example 1 except that 7.4 parts of 2,2-bis (hydroxymethyl) propanoic acid was used instead of 2,2-bis (hydroxymethyl) butanoic acid used as (C) in Synthesis Example 1. Was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a solution of a polyester resin having a pale yellow transparent, non-volatile content of 50.2% and a viscosity of 4,200 mPa · s. The polyester resin had an acid value of 5.6 mgKOH / g, a hydroxyl value of 2.1 mgKOH / g, a glass transition temperature of -35 ° C., a weight average molecular weight (Mw) of 75,000, and Mw / Mn = 3.41.

(Synthesis Example 7)
The same as Synthesis Example 1 except that 11.1 parts of 2,4-di (hydroxymethyl) benzoic acid was used instead of 2,2-bis (hydroxymethyl) butanoic acid used as (C) in Synthesis Example 1. And dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a pale yellow transparent polyester resin solution having a nonvolatile content of 50.2% and a viscosity of 4,800 mPa · s. The polyester resin had an acid value of 4.7 mgKOH / g, a hydroxyl value of 1.8 mgKOH / g, a glass transition temperature of -35 ° C., a weight average molecular weight (Mw) of 75,000, and Mw / Mn of 3.00.

(Synthesis Example 8)
The amount of sebacic acid used as (A) used in Synthesis Example 1 was changed to 30.3 parts, and 2,2-bis (hydroxymethyl) butanoic acid used as (C) was not used. The reaction was performed in the same manner as in Synthesis Example 1 except that 9.5 parts of trimellitic anhydride was used, but the reaction was stopped because the viscosity increased rapidly during gelation and gelled.

(Synthesis Example 9)
The amount of sebacic acid used as (A) used in Synthesis Example 1 was changed to 39.4 parts, and 2,2-bis (hydroxymethyl) butanoic acid used as (C) was not used. It was charged using 1.9 parts of trimellitic anhydride.

  After the air in the polymerization tank was replaced with nitrogen gas, the temperature was raised to 160 ° C. in a nitrogen atmosphere while stirring. After confirming dehydration at 160 ° C., the temperature was gradually raised to 240 ° C. over about 8 hours to conduct dehydration reaction. Next, when the acid value became 15 or less, the temperature was lowered to 150 ° C., 0.008 part of tetrabutyl titanate was added as a catalyst, the pressure was gradually reduced while raising the temperature, and the reaction was conducted at 5 torr and 240 ° C. for 3 hours. When the molecular weight was reached, the reaction was terminated.

  After cooling, it was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a pale yellow transparent polyester resin solution having a nonvolatile content of 54.8% and a viscosity of 4,300 mPa · s. The acid value of the polyester resin was 8.4 mgKOH / g, hydroxyl value 4.8 mgKOH / g, glass transition temperature -35 ° C., weight average molecular weight (Mw) 43,000, Mw / Mn = 1.88.

(Synthesis Example 10)
Synthetic Example 1 except that isophthalic acid used as (a1) in Synthesis Example 1 was not used but 40.4 parts of sebacic acid and 43.8 parts of adipic acid were used as the dibasic acid component (A). The reaction was carried out in the same manner, and the resultant was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a pale yellow transparent polyester resin solution having a nonvolatile content of 50.0% and a viscosity of 3,200 mPa · s. The polyester resin had an acid value of 5.5 mg KOH / g, a hydroxyl value of 1.2 mg KOH / g, a glass transition temperature of −45 ° C., a weight average molecular weight (Mw) of 60,000, and Mw / Mn of 3.00.

(Synthesis Example 11)
Without using neopentyl glycol used as (b1) in Synthesis Example 1, as diol (B), 13.9 parts of 1,4-butanediol, 18.2 parts of 1,6-hexanediol, and 1 , 8-octanediol was reacted in the same manner as in Synthesis Example 1 except that 29.2 parts were used, dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3), light yellow and transparent with a nonvolatile content of 50. A polyester resin solution having a viscosity of 1% and a viscosity of 3,700 mPa · s was obtained. The polyester resin had an acid value of 6.2 mgKOH / g, a hydroxyl value of 1.3 mgKOH / g, a glass transition temperature of −45 ° C., a weight average molecular weight (Mw) of 72,000, and Mw / Mn = 3.43.

(Synthesis Example 12)
Instead of (A), (B), and (C) used in Synthesis Example 1, the following ratios were used.

[Polymerization tank]
Sebacic acid (A) 46.4 parts Isophthalic acid (a1) 43.0 parts 1,4-butanediol (B) 10.7 parts 1,6-hexanediol (B) 14.0 parts 2-methyl-1, 3-propanediol (b1) 15.5 parts 2-ethyl-2-butyl-1,3-propanediol (b1) 19.2 parts 2,2-bis (hydroxymethyl) butanoic acid (C) 1.2 parts

  After the air in the polymerization tank was replaced with nitrogen gas, the temperature was raised to 160 ° C. in a nitrogen atmosphere while stirring. After confirming dehydration at 160 ° C., the temperature was gradually raised to 240 ° C. over about 8 hours to conduct dehydration reaction. Next, when the acid value became 15 or less, the temperature was lowered to 150 ° C., 0.04 part of tetrabutyl titanate was added as a catalyst, and the pressure was gradually reduced while raising the temperature, and 1-5 torr at 260 ° C. for 5 hours. The reaction was performed and the reaction was terminated when the molecular weight reached.

  After cooling, it was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a solution of a polyester resin having a brownish transparency, a non-volatile content of 44.3%, and a viscosity of 4,400 mPa · s. The polyester resin had an acid value of 0.9 mgKOH / g, a hydroxyl value of 4.3 mgKOH / g, a glass transition temperature of −27 ° C., a weight average molecular weight (Mw) of 127,000, and Mw / Mn = 3.26.

(Synthesis Example 13)
The reaction was conducted in the same manner as in Synthesis Example 12 except that the following ratios were used instead of (A), (B), and (C) used in Synthesis Example 12.

[Polymerization tank]
Sebacic acid (A) 46.2 parts Isophthalic acid (a1) 42.8 parts 1,4-butanediol (B) 10.6 parts 1,6-hexanediol (B) 13.9 parts 2-methyl-1, 3-propanediol (b1) 15.4 parts 2-ethyl-2-butyl-1,3-propanediol (b1) 18.8 parts 2,2-bis (hydroxymethyl) butanoic acid (C) 2.4 parts

  After cooling, the resultant was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a solution of a polyester resin having a brownish transparency, a non-volatile content of 45.0%, and a viscosity of 4,600 mPa · s. The polyester resin had an acid value of 1.8 mgKOH / g, a hydroxyl value of 3.8 mgKOH / g, a glass transition temperature of −27 ° C., a weight average molecular weight (Mw) of 111,000, and Mw / Mn = 3.40.

(Synthesis Example 14)
The reaction was conducted in the same manner as in Synthesis Example 12 except that the following ratios were used instead of (A), (B), and (C) used in Synthesis Example 12.

[Polymerization tank]
Sebacic acid (A) 46.2 parts Isophthalic acid (a1) 42.8 parts 1,4-butanediol (B) 9.6 parts 1,6-hexanediol (B) 13.3 parts 2-methyl-1, 3-propanediol (b1) 15.4 parts 2-ethyl-2-butyl-1,3-propanediol (b1) 18.8 parts 2,2-bis (hydroxymethyl) butanoic acid (C) 4.0 parts

  After cooling, the resultant was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a solution of a polyester resin having a brownish transparency, a non-volatile content of 44.2%, and a viscosity of 4,800 mPa · s. The polyester resin had an acid value of 2.8 mg KOH / g, a hydroxyl value of 2.5 mg KOH / g, a glass transition temperature of −27 ° C., a weight average molecular weight (Mw) of 122,000, and Mw / Mn of 3.70.

(Synthesis Example 15)
The reaction was conducted in the same manner as in Synthesis Example 12 except that the following ratios were used instead of (A), (B), and (C) used in Synthesis Example 12.

[Polymerization tank]
Sebacic acid (A) 29.3 parts Dimer acid (A) 84.2 parts 1,4-butanediol (B) 5.8 parts 1,6-hexanediol (B) 7.9 parts 2-methyl-1, 3-propanediol (b1) 9.2 parts 2-ethyl-2-butyl-1,3-propanediol (b1) 11.2 parts 2,2-bis (hydroxymethyl) butanoic acid (C) 2.4 parts

  After cooling, the resultant was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a solution of a polyester resin having a transparent brown color, a non-volatile content of 44.8%, and a viscosity of 4,300 mPa · s. The polyester resin had an acid value of 2.2 mgKOH / g, a hydroxyl value of 2.8 mgKOH / g, a glass transition temperature of −50 ° C., a weight average molecular weight (Mw) of 124,000, and Mw / Mn = 3.35.

(Synthesis Example 16)
The reaction was conducted in the same manner as in Synthesis Example 12 except that the following ratios were used instead of (A), (B), and (C) used in Synthesis Example 12.

[Polymerization tank]
Sebacic acid (A) 46.3 parts Isophthalic acid (a1) 43.0 parts 1,4-butanediol (B) 10.6 parts 1,6-hexanediol (B) 14.6 parts 2-methyl-1, 3-propanediol (b1) 15.5 parts 2-ethyl-2-butyl-1,3-propanediol (b1) 19.8 parts

  After cooling, the mixture was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a solution of a polyester resin having a brown transparent, non-volatile content of 53.6% and a viscosity of 4,200 mPa · s. The polyester resin had an acid value of 0.7 mgKOH / g, a hydroxyl value of 4.5 mgKOH / g, a glass transition temperature of −27 ° C., a weight average molecular weight (Mw) of 63,000, and Mw / Mn = 1.58.

(Synthesis Example 17)
Instead of (A), (B), and (C) used in Synthesis Example 1, the reaction was conducted in the same manner as in Synthesis Example 1 except that the following ratios were used.

[Polymerization tank]
Sebacic acid (A) 46.5 parts Isophthalic acid (a1) 43.1 parts 1,4-butanediol (B) 10.7 parts 1,6-hexanediol (B) 14.3 parts 2-methyl-1, 3-propanediol (b1) 15.5 parts 2-ethyl-2-butyl-1,3-propanediol (b1) 19.4 parts trimethylolpropane 0.5 parts

  After cooling, it was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a solution of a polyester resin having a brownish transparency, a non-volatile content of 55.6%, and a viscosity of 4,400 mPa · s. The polyester resin had an acid value of 3.4 mg KOH / g, a hydroxyl value of 6.3 mg KOH / g, a glass transition temperature of −30 ° C., a weight average molecular weight (Mw) of 73,000, and Mw / Mn = 1.83.

(Synthesis Example 18)
Instead of (A), (B), and (C) used in Synthesis Example 1, the following ratios were used.

[Polymerization tank]
Sebacic acid (A) 46.8 parts Isophthalic acid (a1) 43.3 parts 1,4-butanediol (B) 10.2 parts 1,6-hexanediol (B) 13.4 parts 2-methyl-1, 3-propanediol (b1) 15.6 parts 2-ethyl-2-butyl-1,3-propanediol (b1) 18.2 parts trimethylolpropane 2.4 parts

  After the air in the polymerization tank was replaced with nitrogen gas, the temperature was raised to 160 ° C. in a nitrogen atmosphere while stirring. After confirming dehydration at 160 ° C., the temperature was gradually raised to 240 ° C. over about 8 hours to conduct dehydration reaction. Next, when the acid value became 15 or less, the temperature was lowered to 150 ° C., 0.008 part of tetrabutyl titanate was added as a catalyst, the pressure was gradually reduced while raising the temperature, and the reaction was conducted at 5 torr and 240 ° C. for 3 hours. When the molecular weight was reached, the reaction was terminated.

  After cooling, the mixture was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a solution of a polyester resin having a brown transparent, non-volatile content of 62.2% and a viscosity of 4,200 mPa · s. The acid value of the polyester resin was 8.4 mgKOH / g, the hydroxyl value was 11.4 mgKOH / g, the glass transition temperature was −31 ° C., the weight average molecular weight (Mw) was 32,000, and Mw / Mn = 1.81.

(Synthesis Example 19)
The same composition as in Synthesis Example 18 was charged.

  After the air in the polymerization tank was replaced with nitrogen gas, the temperature was raised to 160 ° C. in a nitrogen atmosphere while stirring. After confirming dehydration at 160 ° C., the temperature was gradually raised to 240 ° C. over about 8 hours to conduct dehydration reaction. Next, when the acid value becomes 15 or less, the temperature is lowered to 150 ° C., 0.008 part of tetrabutyl titanate is added as a catalyst, the pressure is gradually reduced while raising the temperature, and the reaction is carried out at 3 torr and 240 ° C. for 5 hours. To complete the reaction.

  After cooling, it was dissolved in a toluene / ethyl acetate mixed solution (weight ratio = 1/3) to obtain a solution of a polyester resin having a brownish transparency, a non-volatile content of 28.2%, and a viscosity of 4,800 mPa · s. The polyester resin had an acid value of 0.9 mgKOH / g, a hydroxyl value of 3.5 mgKOH / g, a glass transition temperature of −27 ° C., a weight average molecular weight (Mw) of 186,000, and Mw / Mn = 7.62.

For each resin solution obtained from Synthesis Examples 1 to 19, the appearance of the solution, the nonvolatile content (TS), the weight average molecular weight (Mw) of the polyester resin, the glass transition temperature (Tg), the acid value (AV) and the hydroxyl value ( OHV) was determined according to the following method, and the results are shown in Table 1. Each polyester resin determined by ¹ H-NMR, ¹³ C-NMR (all manufactured by JEOL Ltd .: ECX-400) and pyrolysis GC-MS (manufactured by JEOL Ltd .: DX303HF) using a derivatization method. Table 2 shows the content (mol%) of the structural site derived from each component contained in the composition.

<Appearance of solution>
The appearance of each resin solution was visually evaluated.

<Measurement of non-volatile content (TS)>
About 1 g of each resin solution was weighed in a metal container, dried in an oven at 150 ° C. for 20 minutes, the residue was weighed, and the remaining rate was calculated to obtain a nonvolatile content concentration (solid content) (unit:%).

<Measurement of solution viscosity (Vis)>
Each resin solution was measured with a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) at 25 ° C. under conditions of 12 rpm and 1 minute rotation (unit: mPa · s).

<Measurement of weight average molecular weight (Mw)>
For measurement of Mw, GPC (gel permeation chromatography) “HPC-8020” manufactured by Tosoh Corporation was used.

  GPC is liquid chromatography that separates and quantifies substances dissolved in a solvent (THF; tetrahydrofuran) based on the difference in molecular size, and the number average molecular weight (Mn) and the weight average molecular weight (Mw) are determined in terms of polystyrene. .

<Measurement of glass transition temperature (Tg)>
The measurement was performed by connecting a “SSC5200 disk station” (manufactured by Seiko Instruments Inc.) to a robot DSC (differential scanning calorimeter) “RDC220” (manufactured by Seiko Instruments Inc.).

  About 10 mg of sample was weighed in an aluminum pan and set in a DSC apparatus (reference: the same type of aluminum pan without sample). After heating at 300 ° C. for 5 minutes, using liquid nitrogen − Rapid cooling was performed to 120 ° C. Thereafter, the temperature was raised at 10 ° C./min, and the glass transition temperature (Tg) was calculated from the obtained DSC chart (unit: ° C.).

<Measurement of acid value (AV)>
About 1 g of a sample (polyester resin solution: about 50%) is accurately weighed in a stoppered Erlenmeyer flask, and 100 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution is added and dissolved. To this was added phenolphthalein test solution as an indicator and titrated with 0.1N alcoholic potassium hydroxide solution. Titration was continued until the solution was light red and held for 30 seconds. The acid value was determined by the following formula. The acid value was a numerical value of the dry state of the resin (unit: mgKOH / g).

Acid value (mgKOH / g) = {(5.61 × a × F) / S} / (Nonvolatile content concentration / 100)
Where S: Amount of sample collected (g)
a: Consumption of 0.1N alcoholic potassium hydroxide solution (ml)
F: Potency of 0.1N alcoholic potassium hydroxide solution

<Measurement of hydroxyl value (OHV)>
About 1 g of a sample (polyester resin solution: about 50%) is accurately weighed in a stoppered Erlenmeyer flask, and 100 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution is added and dissolved. Further, exactly 5 ml of an acetylating agent (a solution in which 25 g of acetic anhydride was dissolved in pyridine to make a volume of 100 ml) was added and stirred for about 1 hour. To this, phenolphthalein test solution is added as an indicator and titrated with 0.5N alcoholic potassium hydroxide solution. Titration was continued until the solution was light red and lasted 30 seconds.

  The hydroxyl value was determined by the following formula. The hydroxyl value was a numerical value in the dry state of the resin (unit: mgKOH / g).

Hydroxyl value (mgKOH / g) = [{(ba) × F × 28.05} / S] / (Nonvolatile content concentration / 100) + D
Where S: Amount of sample collected (g)
a: Consumption of 0.5N alcoholic potassium hydroxide solution (ml)
b: Consumption of the 0.5N alcoholic potassium hydroxide solution in the blank experiment (ml)
F: Potency of 0.5N alcoholic potassium hydroxide solution
D: Acid value (mgKOH / g)

Example 1
25 parts of toluene is added to 50 parts by weight of the polyester resin solution obtained in Synthesis Example 1 in terms of non-volatile content, and as reactive compound (E), HBAP (2,2′-bishydroxymethylbutanol tris [ 3- (1-aziridinyl) propionate])) 0.25 part by weight was added and stirred well to obtain a pressure sensitive adhesive composition of the present invention. This was coated on a release-treated polyester film (hereinafter referred to as “release film”) so that the thickness after drying was 25 μm, and dried at 100 ° C. for 2 minutes to form an adhesive layer.

  After drying, one side of a polarizing film having a multilayer structure in which both sides of a polyvinyl alcohol (PVA) polarizer are sandwiched between triacetyl cellulose protective films (hereinafter referred to as “TAC film”) is bonded to the adhesive layer. A laminate having a configuration of “film / adhesive layer / TAC film / PVA / TAC film” was obtained.

  Next, the obtained laminate was aged (dark reaction) for one week under the condition of a temperature of 23 ° C. and a relative humidity of 50%, and the reaction of the adhesive layer was advanced to obtain a bonded polarizing plate (laminate).

(Comparative Example 1)
An attempt was made to produce a bonded polarizing plate in the same manner as in Example 1 except that the resin solution obtained in Synthesis Example 9 was used instead of the resin solution obtained in Synthesis Example 1. Although it was possible, some fluctuations occurred on the coated surface.

(Comparative Examples 2 and 3)
A bonded polarizing plate was produced in the same manner as in Example 1 except that the resin solutions obtained in Synthesis Examples 10 and 11 were used instead of the resin solution obtained in Synthesis Example 1.

(Examples 2 to 7)
Synthesis Example 1 A bonded polarizing plate was produced in the same manner as in Example 1 except that the resin solutions obtained in Synthesis Examples 2 to 7 were used instead of the resin solution.

(Examples 8 and 9)
Instead of HBAP which is the reactive compound (E) used in Example 1, TGMXDA (N, N, N ′, N′-tetraglycidyl-m-xylylenediamine) (Example 8), a carbodiimide compound. A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, except that 0.25 parts by weight of “Carbodilite V-05” (manufactured by Nisshinbo Industries, Inc.) (Example 9) was used. Using these, an adhesive-processed polarizing plate was produced in the same manner as in Example 1.

(Comparative Examples 4 and 5)
In the same manner as in Examples 8 and 9, except that the resin solution obtained in Synthesis Example 9 was used instead of the resin solution in Synthesis Example 1 used in Examples 8 and 9, respectively, the bonded polarizing plate was obtained. Produced. At that time, a slight fluctuation occurred on the surface.

(Example 10)
25 parts by weight of isopropyl alcohol (IPA) is added to 50 parts by weight of the polyester resin solution obtained in Synthesis Example 1 in terms of non-volatile content, and an Al chelate [aluminum tris (acetylacetonate) is added as the reactive compound (E). )] 0.25 part by weight was added and stirred well to obtain a pressure-sensitive adhesive composition of the present invention. Using this, a bonded polarizing plate was produced in the same manner as in Example 1.

(Comparative Example 6)
A bonded polarizing plate was produced in the same manner as in Example 10, except that the resin solution obtained in Synthesis Example 9 was used instead of the resin solution in Synthesis Example 1 used in Example 10. At that time, a slight fluctuation occurred on the surface.

Example 11
25 parts of toluene is added to 50 parts by weight of the polyester resin solution obtained in Synthesis Example 12 in terms of nonvolatile content, and 1.0 part by weight of trimethylolpropane adduct of tolylene diisocyanate, which is a polyisocyanate compound, is added. The pressure-sensitive adhesive composition of the present invention was obtained. Using this, a bonded polarizing plate was produced in the same manner as in Example 1.

(Examples 12 and 13)
A pressure-sensitive adhesive composition of the present invention was obtained in the same manner as in Example 11 except that the polyester resin solution in Example 11 was replaced with the polyester resin solution synthesized in Synthesis Examples 13 and 14. Using this, a bonded polarizing plate was produced in the same manner as in Example 1.

(Comparative Example 7)
A bonded polarizing plate was produced in the same manner as in Example 11 except that the resin solution obtained in Synthesis Example 15 was used instead of the resin solution in Synthesis Example 12 used in Example 11.

(Comparative Example 8)
The resin solution obtained in Synthesis Example 16 was used in place of the resin solution in Synthesis Example 1 used in Example 1, and the polyester resin solution obtained in Synthesis Example 16 was added to 50 parts by weight in terms of nonvolatile content with toluene. 25 parts were added, and 0.25 parts by weight of HBAP (2,2′-bishydroxymethylbutanol tris [3- (1-aziridinyl) propionate])) and DMBA (2,2 ′) were added as the reactive compound (E). -1.0 part by weight of bis (hydroxymethyl) butanoic acid) was added and stirred well to obtain a pressure-sensitive adhesive composition. Using this adhesive composition, a bonded polarizing plate was produced in the same manner as in Example 1.

(Comparative Examples 9-11)
Adhesion processing was carried out in the same manner as in Example 11 except that the polyester resin solutions obtained in Synthesis Examples 17, 18, and 19 were used in place of the polyester resin solution in Synthesis Example 12 used in Example 11. A polarizing plate was produced.

  The pot life and coating processability of the pressure-sensitive adhesive compositions obtained in Examples and Comparative Examples were evaluated by the following methods. The results are shown in Table 3.

<Evaluation method of pot life>
About the pressure sensitive adhesive composition obtained by each Example and the comparative example, it is a viscosity on condition of 12 rpm and rotation for 1 minute in a B-type viscometer (made by Tokyo Keiki Co., Ltd.) every 10 hours at 25 ° C. Was measured, and pot life (pot life) was evaluated in three stages.

○: “No problem at all. The rate of increase in viscosity up to 8 hours is less than 2 times.”
Δ: “Slight increase in viscosity is observed and the rate of increase in viscosity up to 5 hours is less than 2 times.”
X: “A sudden increase in viscosity was observed and gelled in less than 5 hours.

<Coating process evaluation method>
The pressure-sensitive adhesive composition obtained in each Example and Comparative Example was applied to a release-treated polyester film at a speed of 2 m / min with a comma coater so that the thickness after drying was 25 μm. It dried in 100 degreeC oven, the 50-micrometer-thick polyester film was bonded together and laminated | stacked, and the pressure sensitive adhesive sheet was produced. The state of the coated surface was visually observed and evaluated in three stages.

○: “No problem at all”
Δ: “Slight repellency and foaming are recognized at the end of the coated surface, but there is no practical problem.”
×: “Repelling, foaming and streaking are recognized on the coated surface, and there are practical problems.”

  About the pressure sensitive adhesive composition obtained in the examples and comparative examples or the bonded polarizing plate (laminate), the refractive index, heat resistance, moist heat resistance, optical properties, and removability of the coating film were determined by the following methods. It was evaluated with. The results are shown in Table 3.

<Evaluation method of refractive index of coating film>
After the pressure-sensitive adhesive compositions obtained in Examples and Comparative Examples were coated on a release film and dried in an oven at 120 ° C., a pressure-sensitive adhesive layer having a thickness of 25 μm was provided, and then a polyester film Were laminated together to produce a pressure-sensitive adhesive sheet.

  Thereafter, the Abbe refractometer “DR-M2” (manufactured by ATAGO) was irradiated with sodium D-line in an atmosphere at 25 ° C. to measure the refractive index of the adhesive layer on the adhesive sheet.

<Evaluation method of optical characteristics>
The pressure-sensitive adhesive composition obtained in each Example and Comparative Example was applied to a release-treated polyester film and dried, and after a pressure-sensitive adhesive layer having a thickness of 25 μm was provided, it was further subjected to a release treatment. A polyester film was laminated. After aging the pressure-sensitive adhesive layer sandwiched between the peel-treated polyester films at a temperature of 23 ° C. and a relative humidity of 50% for one week, both the peel-treated polyester films were removed, and the pressure-sensitive adhesive layer alone was removed. While visually judging the appearance, HAZE was measured by “NDH-300A” [manufactured by Nippon Denshoku Industries Co., Ltd.].

○: “No problem in practical use. HAZE: less than 1.”
Δ: “No cloudiness is observed, and HAZE: 1 or more and less than 3”
X: “Slight fogging is observed, optical interference unevenness is observed, or HAZE: 3 or more.

<Method for evaluating heat resistance and heat and humidity resistance>
The bonded polarizing plate (laminate) is cut into a size of 150 mm × 80 mm, the release film is peeled off, and the absorption axis of each polarizing plate is orthogonal to both surfaces of a 1.1 mm thick float glass plate. It stuck using the laminator. Subsequently, the glass plate on which the polarizing plate is attached is held in an autoclave at 50 ° C.-5 atm for 20 minutes to firmly adhere the polarizing plate to the glass plate, and the polarizing plate and the glass plate are laminated. I got a thing.

  As evaluation of heat resistance, floating peeling after leaving the laminate for 1000 hours at 120 ° C. and light leakage (white spots) when light was transmitted through the laminate were visually observed.

  In addition, as an evaluation of moisture and heat resistance, the laminate was left to stand for 1000 hours at 80 ° C. and a relative humidity of 90%, and light leakage (white spots) when light was transmitted through the laminate was visually observed. did.

  The heat resistance and moist heat resistance were evaluated based on the following three-stage evaluation criteria.

○: “No floating peeling or whitening is observed, and there is no problem in practical use.”
Δ: “Slightly floating peeling or whitening is observed, but there is no practical problem”
×: “There are floating floats and white spots on the whole surface, which is not practical”
Means each.

<Evaluation method of removability (reworkability)>
The bonded polarizing plate (laminated body) is cut into a size of 25 mm × 150 mm, the release film is peeled off, and is attached to a float glass plate with a thickness of 1.1 mm using a laminator. The polarizing plate was firmly adhered to the glass plate by holding it for 20 minutes. After leaving this test piece at 23 ° C. and 50% relative humidity for 1 week, a 180 ° peel test was performed in which the test piece was peeled off at a speed of 300 mm / min in the direction of 180 °, and the fogging of the glass surface after peeling was visually observed. Evaluation was made in three stages.

○: “No cloudiness, no problem in practical use”
Δ: “Slightly cloudy, but practically no problem”
X: “Transfer of the adhesive layer is recognized over the entire surface, which is impractical”
Means each.

  As described above, it can be seen that the pressure-sensitive adhesive composition of the present invention is excellent in coating processability, heat resistance, moist heat resistance, optical characteristics, removability, and refractive index controllability.

  On the other hand, in Synthesis Example 9 using trimellitic anhydride, the polymerization stability of the polyester resin is not good, and the pressure-sensitive adhesive composition of Comparative Examples 1, 4, 5, and 6 is probably because it contains a heterogeneous part. It can be seen that although the product could be coated, the optical properties were not good. Further, Comparative Example 2 containing the polyester resin of Synthesis Example 10 in which most of the components are aliphatic components, Comparative Example 7 containing the polyester of Synthesis Example 15, and a diol having an alkyl group in the side chain It can be seen that the pressure-sensitive adhesive composition of Comparative Example 3 containing the polyester resin of Synthetic Example 11 that was not developed was not good in heat resistance and moist heat resistance although it could be applied.

  In addition, the pressure-sensitive adhesive composition of Comparative Example 8 in which DMBA was added to the polyester of Synthesis Example 16 synthesized without using dioxycarboxylic acid (C) increased in viscosity 3 hours after the addition. There is a problem in life. Moreover, the heat-and-moisture resistance fall was seen.

  The pressure-sensitive adhesive composition of the present invention cannot form an acrylic resin because it can form a polymer in which an aromatic ring or an alicyclic ring is introduced into the main chain skeleton while maintaining a cohesive force peculiar to a polyester resin. The adhesive properties can be expressed. Examples thereof include heat resistance, moist heat resistance, optical characteristics, removability and the like in an optical laminate as in the present invention. In particular, for optical laminate applications, it is important that there is no light leakage, which is an optical characteristic. With the recent increase in size of displays, the required performance such as control of refractive index and prevention of static charge during reworking is increasing. It is getting stricter. Therefore, the pressure-sensitive adhesive composition of the present invention is considered to be more useful because it can exhibit properties that have been difficult so far as described above.

  The pressure-sensitive adhesive composition of the present invention is suitable for use as an optical member, and in addition to general labels and seals, paints, elastic wall materials, waterproof coating materials, flooring materials, tackifiers, adhesives, laminates Structural adhesives, sealing agents, molding materials, surface modification coating agents, binders (magnetic recording media, ink binders, casting binders, fired brick binders, graft materials, microcapsules, glass fiber sizing, etc.), urethane foam (Hard, semi-rigid, soft), urethane RIM, UV / EB curable resin, high solid paint, thermosetting elastomer, microcellular, fiber processing agent, plasticizer, sound absorbing material, vibration damping material, surfactant, gel coat agent Resin for artificial marble, impact modifier for artificial marble, resin for ink, film (laminate adhesive, protective film) Etc.), laminated glass resin, reactive diluent, various molding materials, elastic fiber, artificial leather, as a raw material for synthetic leather, can also very effectively used as various resin additives and a raw material thereof or the like.

Claims (11)

  A dibasic acid component (A) containing a dibasic acid component (a1) having an aromatic ring and / or an alicyclic structure, a diol (b1) having an alkyl group in its side chain and no carboxyl group, A glass transition temperature of −80 to 0 ° C. obtained by reaction of a diol (B) having no carboxyl group and a dioxycarboxylic acid (C) having two hydroxyl groups and one or more carboxyl groups in one molecule. Polyester resin.   The polyester resin according to claim 1, comprising 5 to 50 mol% of a structure derived from the dibasic acid component (a1) having an aromatic ring and / or an alicyclic structure.   3. The polyester resin according to claim 1, comprising 5 to 40 mol% of a structure derived from the diol (b1) having an alkyl group in a side chain and not having a carboxyl group.   The polyester resin according to any one of claims 1 to 3, comprising 0.1 to 10 mol% of a structure derived from dioxycarboxylic acid (C).   5. The polyester resin according to claim 1, wherein the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2.0 to 6.0.   The polyester resin according to any one of claims 1 to 5, wherein the weight average molecular weight is 30,000 to 1,000,000.   7. The polyester resin according to claim 1, wherein the total of the acid value and the hydroxyl value is 0.1 to 30 mg KOH / g.   A pressure-sensitive adhesive composition comprising the polyester resin according to claim 1 and a reactive compound (E) capable of reacting with the polyester resin.   The reactive compound (E) is at least one selected from the group consisting of a polyfunctional epoxy compound, a polyfunctional aziridine compound, a polyfunctional carbodiimide compound, a polyfunctional oxazoline compound, a polyfunctional isocyanate compound, and a metal chelate compound. The pressure-sensitive adhesive composition according to claim 8.   The laminated body formed by laminating | stacking an optical member on the pressure sensitive adhesive layer formed from the pressure sensitive adhesive composition of Claim 8 or 9.   A liquid crystal cell member comprising a glass member for a liquid crystal cell, a pressure sensitive adhesive layer formed from the pressure sensitive adhesive composition according to claim 8 or 9, and an optical member.