JP4863666B2 - Pressure-sensitive adhesive and pressure-sensitive adhesive sheet containing polyester resin - Google Patents

Description

The present invention has excellent tack and high cohesive strength, adhesive comprising a polyester-based resins having heat resistance, pressure-sensitive adhesive sheet comprising a layer formed of the optical member, and PSA comprising the pressure-sensitive adhesive It is about.

  Conventionally, polyester resins have excellent heat resistance, chemical resistance, durability, and mechanical strength, and are used in a wide range of applications such as films, PET bottles, fibers, toners, and electrical parts. Polyester resins are excellent in adhesiveness, and are also used as hot-melt adhesives or thermosetting adhesives that react with heat using a curing agent or the like.

  These adhesives have a glass transition temperature and melting point that are considerably higher than room temperature, or are cross-linked to a fairly high density in order to exhibit excellent adhesive properties such as adhesion and durability. It is in a very hard state. For this reason, in the said adhesive agent, the apparatus for heating in order to make it adhere | attach was needed, and there existed a problem that cost increased. From such a viewpoint, recently, adaptation as a pressure-sensitive adhesive has also been proposed to compensate for the above-described drawbacks (see, for example, Patent Documents 1 to 3). That is, in Patent Document 1, a pressure-sensitive adhesive composed of an aliphatic polyester having a specific structure with a glass transition temperature of −40 ° C. or lower is disclosed in Patent Document 2, and an aliphatic diol having a specific structure, a trihydric or higher polyhydric alcohol, and / or Alternatively, a pressure-sensitive adhesive containing a polyester having a number average molecular weight of 5000 or more and a degree of dispersion of 2.2 or more using a trivalent or higher polyvalent carboxylic acid as an essential raw material component is a side chain containing a hydrocarbon group in Patent Document 3. , A pressure-sensitive adhesive having a cyclohexane structure in the main chain and containing a polyester having a number average molecular weight of 5000 or more has been proposed.

Japanese Patent Laid-Open No. 11-21340 JP 2002-194314 A JP 2004-99792 A

  When a polyester resin is used for the pressure-sensitive adhesive, the polyester resin itself is required to be improved in flexibility, particularly initial adhesiveness. In order to improve the initial adhesiveness, a method of lowering the glass transition temperature by using aliphatic in the structure of the polyester resin as in Patent Document 1 is used, but if the glass transition temperature is lowered, the characteristics of the polyester resin are reduced. That is, the heat resistance, durability, and mechanical strength are reduced. In addition, the resin itself is easily crystallized, and if the crystallization occurs at room temperature or higher, it becomes tack-free and the initial adhesiveness is lost. When the method using the cyclohexane structure is used for the structure of the polyester resin as in Patent Document 3, the heat resistance, durability, and mechanical strength are improved as compared with the polyester resin using an aliphatic group. Heat resistance, durability, and mechanical strength are inferior to those of polyester-based resins using. As in the above-mentioned Patent Document 2, in the method using polycarbonate diol or the like, flexibility tends to decrease, initial tackiness decreases, and sufficient adhesive strength cannot be exhibited at a pressure of about a finger pressure, which is a characteristic of the pressure-sensitive adhesive. There is a problem.

In view of the above circumstances, and exhibit sufficient adhesion at a pressure of about acupressure, comprising excellent adhesion, heat resistance, a deployable polyester resins in a wide range of applications with mechanical strength adhesive, more result of various studies to obtain a pressure-sensitive adhesive sheet, polycondensation using a polyol component and a carboxylic acid components fraction containing specific alkoxy group-containing diol (a), an alkoxy group in the side chain of the polyester resin Was found and the object of the present invention was achieved by using a polyester resin having a predetermined glass transition temperature, and the present invention was completed.

That is, the gist of the present invention is a polyester resin obtained by polycondensation of (A) a polyol component and (B) a carboxylic acid component, wherein (A) the polyol component contains an alkoxy group represented by the general formula (2) The present invention relates to a pressure-sensitive adhesive comprising a polyester resin containing a diol (a) and having a glass transition temperature of −10 ° C. or lower .

(R is a hydrocarbon group having 1 or more carbon atoms, and n is an integer of 1 or more. )

  The number average molecular weight of the polyester resin is preferably 5000 or more from the viewpoint of mechanical strength and heat resistance.

  It is preferable that the cross-linking agent is contained in such a ratio that the reactive group contained in the cross-linking agent is 0.2 to 10 equivalents per equivalent of hydroxyl group and / or carboxyl group contained in the polyester-based resin.

  Furthermore, this invention relates to the adhesive sheet characterized by providing the layer which consists of the said adhesive in the optical member containing the said adhesive, and the single side | surface or both surfaces of a support body.

Adhesive comprising a poly ester resin of the present invention is excellent in adhesive properties, heat resistance, and has an excellent effect in mechanical strength.

  In the present invention, by introducing an alkoxy group into the side chain in the polyester-based resin structure, high initial tackiness that has not been obtained with conventional polyester-based resins can be obtained, and sufficient adhesive strength can be obtained at a pressure of about a finger pressure. The pressure-sensitive adhesive and sheet that do not impair the heat resistance, durability, and mechanical strength, which are the characteristics of polyester resins, have been obtained, and it has become possible to pioneer new uses for polyester resins. .

  The present invention is a polyester resin obtained by polycondensation of (A) a polyol component and (B) a carboxylic acid component, wherein at least one of (A) the polyol component and (B) the carboxylic acid component is an alkoxy group in the side chain. It is the polyester-type resin containing the raw material component which has this.

  Next, the polyol component (A) will be described.

  Although it does not specifically limit as a polyol component (A), It is preferable that the alkoxy group containing diol (a) is included from the point which can introduce | transduce an alkoxy group into the side chain of the polyester-type resin obtained, General formula (1) ):

It is more preferable that the alkoxy group containing diol (a) shown by these is included.

  In general formula (1), R is a hydrocarbon group having 1 or more carbon atoms, a is an integer of 0 to 10, preferably an integer of 2 to 5, and b is an integer of 1 to 10. Yes, preferably an integer of 1 to 5, c is an integer of 1 or more, preferably an integer of 5 to 40, d is an integer of 0 to 10, and is an integer of 1 to 5 It is preferable.

  R in the general formula (1) may be a hydrocarbon group having 1 or more carbon atoms, and the hydrocarbon group having 1 or more carbon atoms is not particularly limited, but may be a methyl group, an ethyl group, a propyl group, C1-C9 hydrocarbon groups, such as a butyl group, a pentyl group, a hexyl group, an octyl group, a nonyl group, are mentioned, Among these, it is preferable that it is a C1-C4 hydrocarbon group.

  In the present invention, among the above general formula (1), in particular, the general formula (2):

It is preferable that it is the alkoxy group containing diol shown by the point which can exhibit the outstanding initial stage adhesive force and durability.

  R in the general formula (2) is a hydrocarbon group having 1 or more carbon atoms, and examples thereof include those described above.

  N in General formula (2) is an integer greater than or equal to 1, and it is preferable that it is an integer of 5-40. When n is 0, an alkoxy group cannot be introduced into the side chain in the polyester-based resin structure, so that the effect of the present invention cannot be obtained.

  Moreover, in this invention, it is preferable that the hydroxyl value of the alkoxy-group containing diol (a) shown by General formula (1) is 35-200 KOHmg / g, and it is more preferable that it is 55-110 KOHmg / g. If the hydroxyl value is less than the lower limit, the mechanical strength and heat resistance tend to decrease, and if the upper limit is exceeded, the initial adhesive strength tends to decrease.

  Commercial products of the diol (a) having an alkoxy group in the side chain represented by the general formula (2) include “TOE-2000H” manufactured by Kyowa Hakko Chemical Co., Ltd.

  The polyester-based resin of the present invention uses a diol (a) represented by the general formula (1) as a polyol component (A) as a raw material component composed of a polyol component (A) and a carboxylic acid component (B). It is preferable that it is obtained by polycondensation. The polyester-based resin thus obtained is a polyester-based resin having a structural part derived from the diol (a) represented by the general formula (1), and the content of the structural part is not particularly limited. The optimum content can be selected according to the cohesiveness and mechanical strength. In the polyester resin, the structure part derived from the diol (a) represented by the general formula (1) is 1.5 to 10 mol. % Is preferable, and 2 to 7 mol% is more preferable. When the structure part derived from the diol (a) represented by the general formula (1) is less than the lower limit value, the initial adhesive strength tends to decrease, and when the upper limit value is exceeded, the mechanical strength and heat resistance tend to decrease. is there.

  As a polyol component (A) used by this invention, it may consist only of diol (a) which has an alkoxy group in the side chain shown by General formula (1), and polyol other than diol (a) is included. You may go out.

  Examples of polyols other than diol (a) include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,8- Linear aliphatic diols such as octanediol, 1,9-nonanediol, 1,10-decanediol; neopentyl glycol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propane Diol, 2-methyl-2-propyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4 -Pentanediol, 2,4-diethyl-1,5-pentanediol, 1,3,5-trimethyl-1,3-pentanedio Methylphenol, 2 and aliphatic diol having a hydrocarbon group side chains, such as methyl-1,6-hexanediol and the like, can be used more than those one or two. Among these, from the point that the initial adhesiveness, mechanical strength, and heat resistance can be balanced, a straight chain aliphatic diol having 2 to 6 carbon atoms, particularly 1,4-butanediol, 1,6-hexanediol, Ethylene glycol or an aliphatic diol having a hydrocarbon group side chain having 1 to 4 carbon atoms, particularly neopentyl glycol is preferred.

  Further, if necessary, a small amount of polyether diol, trihydric or higher polyhydric alcohol may be contained.

  Examples of the polyether diol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like obtained by ring-opening polymerization of ethylene oxide, propion oxide, tetrahydrofuran, and the like, and one or more of these can be used.

  Examples of the trihydric or higher polyhydric alcohol include trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, etc. These may be used alone or in combination of two or more. Among these, trimethylolpropane is preferable from the viewpoint of improving heat resistance. Although content of the polyhydric alcohol more than trivalence is not specifically limited, It is preferable that it is 0.1-5.0 mol%, and it is more preferable that it is 0.5-3.0 mol%.

  The blending amount of the diol (a) represented by the general formula (1) is preferably 2 to 14 mol%, more preferably 3 to 9 mol% in the polyol preparation component (A). If the blending amount of the diol (a) is less than the lower limit value, the initial adhesive strength tends to decrease, and if the amount exceeds the upper limit value, the mechanical strength and heat resistance tend to decrease. In addition, said compounding quantity is a value in a preparation component, and is not the ratio in the glycol of the resin composition made.

  Next, the carboxylic acid component (B) will be described.

  The carboxylic acid component (B) is not particularly limited, but when a diol containing an alkoxy group in the side chain is not used as the polyol component (A), an alkoxy group is introduced into the side chain of the resulting polyester resin. It is preferable that the carboxylic acid (b) which has an alkoxy group in a side chain is included from the point which can be performed. Of course, you may use the raw material component which contains an alkoxy group in a side chain in both a polyol component (A) and a carboxylic acid component (B).

  Examples of the carboxylic acid (b) having an alkoxy group in the side chain include polyvinyl ethers described in JP-A No. 2004-307462. Among these, a number average molecular weight of 500 to 3,000 is preferable from the viewpoint that both initial tackiness, mechanical strength, and heat resistance can be balanced.

  Examples of the carboxylic acid other than the carboxylic acid (b) having an alkoxy group in the side chain include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, p- Saturated dicarboxylic acids such as aromatic dicarboxylic acids such as oxybenzoic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, and aliphatic dicarboxylic acids such as octadecanedicarboxylic acid; fumaric acid, maleic acid, Examples thereof include unsaturated dicarboxylic acids such as itaconic acid, tetrahydrophthalic acid, tetrachlorophthalic acid, hexahydrophthalic acid and dimer acids, and one or more of these can be used. If necessary, a small amount of trivalent or higher carboxylic acid such as trimellitic acid, trimesic acid, pyromellitic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid may be contained. Among these, aromatic dicarboxylic acid, especially terephthalic acid, isophthalic acid, and carbon number of 6 to 12 (including carbon of carboxyl group) from the point that the initial adhesiveness, mechanical strength, and heat resistance can be balanced. Aliphatic dicarboxylic acids, particularly sebacic acid, are preferred.

  In the present invention, by using either one of the diol (a) having an alkoxy group or the carboxylic acid (b) having an alkoxy group, or both, an alkoxy group is added to the side chain in the polyester resin structure. However, it is preferable to use a diol (a) having an alkoxy group from the viewpoint of obtaining a polyester resin having a low acid value.

  The content of the alkoxy group in the polyester resin of the present invention is not particularly limited, but it is preferable to introduce about 5 to 300 alkoxy groups per molecule of the polyester resin, and to introduce about 60 to 150. Particularly preferred. If the alkoxy group is less than the lower limit, the initial adhesive strength tends to decrease, and if it exceeds the upper limit, the mechanical strength and heat resistance tend to decrease.

  The blending ratio of the polyol component (A) is preferably 1 equivalent or more, more preferably 1.2 equivalents or more per equivalent of the carboxylic acid component (B), and 2.0 equivalents or more. It is preferable that it is below an equivalent. If the blending ratio of the polyol component (A) is less than the lower limit value, the acid value becomes high and it becomes difficult to increase the molecular weight, and if it exceeds the upper limit value, the yield is undesirably changed.

  The polyester resin of the present invention includes a polyol component (A) and a carboxylic acid component (B) containing the diol component (a) represented by the general formula (1), or a carboxylic acid having a polyol component (A) and an alkoxy group. It can be obtained by subjecting the carboxylic acid component (B) containing (b) to a polycondensation reaction by a known method in the presence of a catalyst.

  In the polycondensation reaction, first, a polymerization (esterification) reaction is performed, and then a condensation reaction is performed.

  In such polymerization (esterification) reaction, a catalyst is used. Specifically, catalysts such as titanium-based tetraisopropyl titanate and tetrabutyl titanate, antimony-based antimony trioxide, germanium-based catalyst such as germanium oxide, Examples thereof include zinc acetate, manganese acetate, and dibutyltin oxide, and one or more of these are used.

  The blending amount of the catalyst is preferably 1 to 10,000 ppm, more preferably 10 to 5000 ppm, and still more preferably 10 to 3000 ppm with respect to all copolymer components. If the blending amount is less than the lower limit, the polymerization reaction may not proceed sufficiently. Conversely, if the upper limit is exceeded, there is no advantage such as shortening of the reaction time, and side reactions are liable to occur.

  The temperature during the polymerization (esterification) reaction is usually 160 to 260 ° C, more preferably 180 to 250 ° C, and particularly preferably 200 to 250 ° C. If the temperature is lower than the lower limit, the reaction does not proceed sufficiently. Conversely, if the upper limit is exceeded, side reactions such as decomposition may occur, which is not preferable. Moreover, a pressure is implemented under a normal pressure.

  After such a polymerization (esterification) reaction is performed, a condensation reaction is performed. The conditions at this time are the same amount of the same catalyst as in the above esterification, and preferably 220 It is preferable that the reaction system is gradually reduced in pressure to ˜260 ° C., more preferably 230 to 250 ° C., and finally the reaction is carried out at 5 hPa or less. If the reaction temperature is lower than the lower limit, the reaction may not proceed. Conversely, if the upper limit is exceeded, side reactions such as decomposition may occur, which is not preferable.

  Next, an adhesive using the polyester resin will be described.

  When using the polyester-type resin of this invention as an adhesive, it is preferable that a number average molecular weight is 5000 or more, It is more preferable that it is 10,000-100000, It is further more preferable that it is 15000-80000. When the number average molecular weight is less than the lower limit, sufficient cohesive force cannot be obtained when the pressure-sensitive adhesive is used, and heat resistance and mechanical strength tend to decrease. On the other hand, if the molecular weight is increased too much, the flexibility is lost, the initial tackiness is lowered, and there is a tendency that sufficient adhesive force cannot be exhibited with a pressure of about a finger pressure.

  The glass transition temperature of the polyester resin of the present invention is preferably −10 ° C. or lower, and more preferably −25 ° C. or lower. When the glass transition temperature exceeds the upper limit value, the flexibility is lost, the initial tackiness is lowered, and there is a tendency that sufficient adhesive force cannot be exhibited at a pressure of about finger pressure. Moreover, as a minimum of glass transition temperature, it is preferable that it is -100 degreeC or more, It is more preferable that it is -80 degreeC or more, It is further more preferable that it is -70 degreeC or more. If it is less than this lower limit, heat resistance falls and it is not preferable.

  The pressure-sensitive adhesive of the present invention comprises the polyester-based resin of the present invention as a main component, and is usually subjected to a crosslinking treatment to have excellent cohesive strength.

  Any compound having a functional group that reacts with a hydroxyl group and / or a carboxyl group contained in a polyester resin, such as a polyisocyanate compound and a polyepoxy compound, can be used for the crosslinking treatment. Isocyanate compounds are more preferable in terms of achieving both initial tackiness, mechanical strength, and heat resistance.

  Examples of the polyisocyanate compound include polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, and hydrogenated xylylene diisocyanate. Examples include tolylene diisocyanate adducts of trimethylolpropane, isocyanate adducts such as hexamethylene diisocyanate adduct and isophorone diisocyanate adduct. In addition, the said polyisocyanate compound can also use what the isocyanate part was blocked with phenol, lactam, etc. These crosslinking agents may be used alone or in combination of two or more.

  The amount of the crosslinking agent used can be appropriately selected depending on the molecular weight of the polyester resin and the purpose of use. Usually, the reactivity contained in the crosslinking agent with respect to 1 equivalent of the hydroxyl group and / or carboxyl group contained in the polyester resin. It is preferable to contain a crosslinking agent in a ratio of 0.2 to 10 equivalents of groups, particularly 0.5 to 6 equivalents, more preferably 1 to 4 equivalents. If the amount of the reactive group contained in the crosslinking agent is less than the lower limit, the cohesive force tends to be insufficient, and sufficient heat resistance tends to be not obtained. There is a tendency that it becomes worse and sufficient adhesive force cannot be exhibited at a pressure of about a finger pressure.

  Further, instead of the method of adding a crosslinking agent, the crosslinking reaction may be carried out by a method of introducing a radical reactive unsaturated group into the terminal of the polyester-based resin and causing a radical reaction. Examples of the radical reactive unsaturated group include mono (meth) acrylates of diol compounds such as ethylene glycol and diethylene glycol; mono (meth) acrylates or di (meth) acrylates of triol compounds such as trimethylolpropane, glycerin, and trimethylolethane; Examples thereof include hydroxyl group-containing acrylic compounds such as mono (meth) acrylate, di (meth) acrylate or tri (meth) acrylate of tetravalent or higher polyols such as pentaerythritol and dipentaerythritol.

  Using these hydroxyl group-containing acrylic compounds, polyester-based resins with radical-reactive unsaturated bonds introduced at the ends can be heated in the presence of thermal radical initiators, or ultraviolet light can be used in the presence of photoradical initiators. The cross-linking reaction can be performed by irradiating with, or by irradiating radiation such as an electron beam.

  In the pressure-sensitive adhesive of the present invention, conventionally known additives such as tackifiers, softeners, ultraviolet absorbers, stabilizers, anti-static agents, etc., other inorganic or organic fillers, metal powders, pigments, etc. Additives such as powders and particles can be blended.

  Furthermore, this invention relates to the adhesive sheet characterized by providing the layer which consists of said adhesive on the single side | surface or both surfaces of a support body.

  The support is not particularly limited, and examples thereof include polyvinyl chloride, polyvinylidene chloride, polybutene, polybutadiene, polyurethane, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polyethylene, polypropylene, and ethylene-propylene copolymer. Examples thereof include films such as polymethylpentene and polybutylene terephthalate, and porous materials such as metal foil, paper, and nonwoven fabric, among which polyethylene phthalate film is often used.

  The thickness of a support body is not specifically limited, For example, it can select suitably from the range of about 1-100 micrometers, Preferably it is about 10-50 micrometers.

  The pressure-sensitive adhesive sheet of the present invention is formed into a sheet-like or tape-like form by applying the pressure-sensitive adhesive on one or both sides of a support and drying it.

  The coating amount is preferably such that the thickness after drying is 10 to 150 μm, and more preferably 20 to 50 μm.

  Moreover, as drying conditions, it is preferable to dry at 60-140 degreeC, especially 80-120 degreeC for 1 to 30 minutes, especially 2 to 5 minutes.

  Furthermore, the pressure-sensitive adhesive sheet of the present invention may be protected by providing a release sheet outside the pressure-sensitive adhesive layer as necessary. In the pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive layer is formed on one side of the support, the surface of the support opposite to the pressure-sensitive adhesive layer is subjected to a release treatment, whereby the pressure-sensitive adhesive layer is utilized using the release-treated surface. It is also possible to protect.

  The pressure-sensitive adhesive of the present invention can be used as a pressure-sensitive adhesive for electronic parts, a pressure-sensitive adhesive for optical members such as a pressure-sensitive adhesive for polarizing plates, a pressure-sensitive adhesive for soft vinyl chloride, and the like. It is very useful as an agent.

  Examples of the present invention will be described below. The scope of the present invention is not limited by the examples. In the examples, “parts” means “parts by weight”.

<Glass transition temperature>
Measured by DSC method. That is, the test piece was heated and cooled at a rate of 10 ° C./min from room temperature, the calorific value was measured with a differential scanning calorimeter, and two extended lines were drawn on the endothermic curve or exothermic curve, The temperature at the intersection of the 1/2 straight line and the endothermic curve or exothermic curve was taken as the glass transition temperature.

<Initial adhesive strength>
At room temperature (23 ° C.), the adhesive sheet was cut to a width of 25 mm and a length of 200 mm, and the adhesive surface was attached to a stainless steel plate (SUS304) polished with # 280 water-resistant abrasive paper, and 20 mm with a 2 kg rubber roller from above. The pressure-sensitive adhesive sheet was pressed against the stainless steel plate by reciprocating twice at a speed of / sec. Ten seconds later, the 180 ° peel adhesive strength was measured under the condition of a peel speed of 300 mm / min, and the initial adhesive strength was obtained.

<Adhesive strength>
At room temperature (23 ° C.), the adhesive sheet was cut to a width of 25 mm and a length of 200 mm, and the adhesive surface was attached to a stainless steel plate (SUS304) polished with # 280 water-resistant abrasive paper, and 20 mm with a 2 kg rubber roller from above. The pressure-sensitive adhesive sheet was pressed against the stainless steel plate by reciprocating twice at a speed of / sec. After leaving at 23 ° C. for 30 minutes, the 180 ° peel adhesive strength was measured under the same conditions as the initial adhesive strength to obtain the adhesive strength.

<Retention force>
At room temperature (23 ° C.), the adhesive sheet was cut to a width of 25 mm and a length of 100 mm, and a 25 mm width and a length of 25 mm of the adhesive surface were attached to a stainless steel plate (SUS304) polished with # 280 water-resistant abrasive paper. The adhesive sheet was pressed against the stainless steel plate by reciprocating twice at a speed of 20 mm / sec with a 2 kg rubber roller from above. After standing at 23 ° C. for 30 minutes, a load of 1 kg was applied under the conditions of 60 ° C. and 60 RH%, and the time (min) until the adhesive sheet dropped from the stainless steel plate or the shifted distance (mm) after 24 hours was measured. .

<Heat resistance>
In the measurement of the holding force, the measurement was performed under the conditions of 60 ° C. and 60% RH after being left for 30 minutes at 23 ° C., except that the measurement was performed under the conditions of 80 ° C. (dry) after being left for 30 minutes at 23 ° C. Were similarly evaluated.

Example 1
In a four-neck separable flask equipped with a thermometer, a stirrer, a distillation tube and a condenser, a polyol having an alkoxy group in the side chain (in the general formula (2), R = —CH ₂ CH ₃ , n = 20) ( “TOE-2000H” manufactured by Kyowa Hakko Chemical Co., Ltd., 100 g of hydroxyl value: 74.3 KOH mg / g), 62 g of neopentyl glycol, 26 g of 1,4-butanediol, 29 g of ethylene glycol, 31 g of isophthalic acid, 152 g of sebacic acid and Tetra-n-butyl titanate (0.15 g) was charged and heated at 150 to 250 ° C. for 150 minutes to carry out an esterification reaction. Then, the pressure of the reaction system was gradually reduced to 133 Pa after 30 minutes, and further reduced pressure was maintained while maintaining 150 The reaction was performed for a minute. The number average molecular weight of the obtained polyester resin was 18000, the hydroxyl value was 5.9 KOH mg / g, the acid value was 0.3 KOH mg / g, and the glass transition temperature was −48 ° C.

FIG. 1 shows a chart of ¹ H-NMR (reference substance: tetramethylsilane, solvent: CDC ₁₃ ) of the obtained polyester resin.

(Attribution of ¹ H-NMR)
0.96 ppm peak derived from neopentyl glycol 1.08 ppm peak derived from neopentyl glycol 1.14 ppm peak derived from TOE-2000H 1.18 ppm peak derived from TOE-2000H 1.21 ppm peak derived from TOE-2000H 1.22 ppm TOE- Peak derived from 2000H 1.26ppm Peak derived from sebacic acid 1.30ppm Peak derived from sebacic acid 1.58ppm Peak derived from sebacic acid and TOE-2000H 1.61ppm Peak derived from sebacic acid and TOE-2000H 1.69ppm Sebacic acid and TOE-2000H-derived peak 1.70 ppm Sebacic acid and TOE-2000H-derived peak 1.71 ppm Sebacic acid and TOE-2000H-derived peak 1.73 ppm Sebacin And peak derived from TOE-2000H 1.80 ppm peak derived from TOE-2000H 1.83 ppm derived from TOE-2000H 2.05 ppm derived from 1,4-butanediol 2.25 ppm peak derived from sebacic acid 2.27 ppm sebacic acid 2.29 ppm peak derived from sebacic acid 2.30 ppm peak derived from sebacic acid 2.31 ppm peak derived from sebacic acid 2.32 ppm peak derived from sebacic acid 2.35 ppm peak derived from sebacic acid 3.47 ppm derived from TOE-2000H Peak of 3.50 ppm peak derived from TOE-2000H 3.53 ppm peak derived from TOE-2000H 3.88 ppm peak derived from neopentyl glycol 3.99 ppm ethylene glycol and 1,4-butanedio 4.07 ppm peak derived from ethylene glycol 4.09 ppm peak derived from ethylene glycol and 1,4-butanediol 4.09 ppm peak derived from ethylene glycol and 1,4-butanediol Peak derived from ethylene glycol and 1,4-butanediol 4.14 ppm Peak derived from ethylene glycol and 1,4-butanediol 4.17 ppm Peak derived from ethylene glycol and 1,4-butanediol 4.27 ppm Peak derived from ethylene glycol and 1,4-butanediol 4.32 ppm Ethylene glycol And a peak derived from 1,4-butanediol 4.36 ppm A peak derived from ethylene glycol and 1,4-butanediol 4.43 ppm A peak derived from ethylene glycol and 1,4-butanediol 4.44 ppm Peak derived from ethylene glycol and 1,4-butanediol 4.46 ppm Peak derived from ethylene glycol and 1,4-butanediol 4.53 ppm Peak derived from ethylene glycol and 1,4-butanediol 4.55 ppm Ethylene glycol and 1,4 Peak derived from 4-butanediol 4.56 ppm Peak derived from ethylene glycol and 1,4-butanediol 7.51 ppm Peak derived from isophthalic acid 7.55 ppm Peak derived from isophthalic acid 7.59 ppm Peak derived from isophthalic acid 8.21 ppm Isophthalic acid Acid derived peak 8.25 ppm Isophthalic acid derived peak 8.68 ppm Isophthalic acid derived peak

  NMR was measured using “UNITY 300” manufactured by VARIAN.

  The obtained polyester resin was diluted with ethyl acetate to a solid content concentration of 50% by weight. To 100 parts (solid content) of this polyester resin, 5.0 parts (solid content) (crosslinking agent) of trimethylolpropane / tolylene diisocyanate adduct (product name: Coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.)) as a crosslinking agent. (Reactive group contained in 2 / equivalent of 1 equivalent of hydroxyl group of polyester resin) was stirred and applied to a 25 μm thick polyethylene terephthalate film using an applicator and dried at 100 ° C. for 2 minutes. And the adhesive sheet whose thickness of an adhesive layer is 25 micrometers was produced.

Example 2
In a four-neck separable flask equipped with a thermometer, a stirrer, a distillation tube and a condenser, a polyol having an alkoxy group in the side chain (in the general formula (2), R = —CH ₂ CH ₃ , n = 20) ( 200 g of “TOE-2000H” manufactured by Kyowa Hakko Chemical Co., Ltd., hydroxyl value: 74.3 KOH mg / g), 55 g of neopentyl glycol, 21 g of ethylene glycol, 44 g of isophthalic acid, 80 g of sebacic acid, and tetra-n-butyl titanate. 15 g was charged and the esterification reaction was carried out by heating at 150 to 250 ° C. for 180 minutes, then the pressure in the reaction system was gradually reduced to 133 Pa after 30 minutes, and the reaction was continued for 270 minutes while continuing to reduce the pressure. The number average molecular weight of the obtained polyester resin was 15000, the hydroxyl value was 7.1 KOHmg / g, the acid value was 0.4 KOHmg / g, and the glass transition temperature was -43 ° C.

  This polyester resin was diluted with ethyl acetate to a solid concentration of 50% by weight. This polyester resin is charged into a four-necked separable flask equipped with a thermometer, a stirrer, and a reflux condenser, and 1.7 parts of isophorone diisocyanate is added to 100 parts of polyester resin (solid content). Three parts were charged and reacted at 75 ° C. for 8 hours to obtain a polyester resin-based polyurethane solution. 6.6 parts (solid content) of trimethylolpropane / tolylene diisocyanate adduct (product name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent for 100 parts (solid content) of this polyurethane resin-based polyurethane resin (The reactive group contained in the crosslinking agent is 7.3 equivalents / hydroxyl group of the polyester resin 1 equivalent) and stirred, and then applied onto a 25 μm-thick polyethylene terephthalate film using an applicator at 100 ° C. It dried for 2 minutes and produced the adhesive sheet whose thickness of an adhesive layer is 25 micrometers.

Example 3
In a four-neck separable flask equipped with a thermometer, a stirrer, a distillation tube and a condenser, a polyol having an alkoxy group in the side chain (in the general formula (2), R = —CH ₂ CH ₃ , n = 20) ( "TOE-2000H" manufactured by Kyowa Hakko Chemical Co., Ltd., hydroxyl value: 74.3 KOHmg / g) 100 g, trimethylolpropane 2 g, neopentyl glycol 60 g, 1,4-butanediol 26 g, ethylene glycol 29 g, isophthalic acid 31 g In addition, 152 g of sebacic acid and 0.15 g of tetra-n-butyl titanate were charged, and the esterification reaction was carried out by heating at 150 to 250 ° C. for 150 minutes, and then the pressure of the reaction system was gradually reduced to 133 Pa after 30 minutes. The reaction was performed for 90 minutes while continuing the decompression. The number average molecular weight of the obtained polyester resin was 22000, the hydroxyl value was 4.6 KOHmg / g, the acid value was 0.5 KOHmg / g, and the glass transition temperature was −48 ° C.

  This polyester resin was diluted with ethyl acetate to a solid concentration of 50% by weight. To 100 parts (solid content) of this polyester resin, 3.3 parts (solid content) (in the solid content) of trimethylolpropane / tolylene diisocyanate adduct (product name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) The reactive group contained was mixed with 1.7 equivalents / hydroxyl group equivalent of polyester resin) and stirred, and then applied onto a 25 μm thick polyethylene terephthalate film using an applicator and dried at 100 ° C. for 2 minutes. A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer thickness of 25 μm was prepared.

Comparative Example 1
In a four-necked separable flask equipped with a thermometer, stirrer, distillation tube, and condenser, neopentyl glycol 65 g, 1,6-hexanediol 73 g, ethylene glycol 39 g, terephthalic acid 72, isophthalic acid 52 g, sebacic acid 100 g and Charge 0.18 g of antimony trioxide and heat at 150-260 ° C. for 150 minutes to carry out the esterification reaction, then gradually reduce the pressure of the reaction system to 133 Pa after 30 minutes, and continue the reaction for 330 minutes while continuing to reduce the pressure. went. The number average molecular weight of the obtained polyester resin was 17000, the hydroxyl value was 6.2 KOH mg / g, the acid value was 0.4 KOH mg / g, and the glass transition temperature was −20 ° C.

  This polyester resin was diluted with ethyl acetate to a solid concentration of 50% by weight. To 100 parts (solid content) of this polyester resin, 5.5 parts of trimethylolpropane / tolylene diisocyanate adduct (product name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) (solid content) The reactive group contained is 2.1 equivalents / 1 equivalent of the hydroxyl group of the polyester resin) and stirred, and then coated on a 25 μm-thick polyethylene terephthalate film using an applicator and dried at 100 ° C. for 2 minutes. A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer thickness of 25 μm was prepared.

Comparative Example 2
A four-necked separable flask equipped with a thermometer, stirrer, distillation tube and condenser was charged with 61 g of neopentyl glycol, 67 g of 1,6-hexanediol, 36 g of ethylene glycol, 235 g of sebacic acid and 0.18 g of antimony trioxide. The esterification reaction was carried out by heating at 150 to 260 ° C. for 150 minutes, and then the pressure in the reaction system was gradually reduced to 133 Pa after 30 minutes, and further the reaction was carried out for 360 minutes while continuing to reduce the pressure. The number average molecular weight of the obtained polyester resin is 25000, the hydroxyl value is 4.3 KOH mg / g, the acid value is 0.2 KOH mg / g, the glass transition temperature is −55 ° C., the crystallization temperature is 2 ° C., and the melting point is 26 ° C. there were.

  This polyester resin was diluted with ethyl acetate to a solid concentration of 50% by weight. To 100 parts (solid content) of this polyester resin, as a crosslinking agent, trimethylolpropane / tolylene diisocyanate adduct (product name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) 4.4 parts (solid content) (Reactive group contained is 2.5 equivalents / hydroxyl hydroxyl group equivalent of polyester resin) and stirred, and then applied onto a 25 μm thick polyethylene terephthalate film using an applicator and dried at 100 ° C. for 2 minutes. A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer thickness of 25 μm was prepared.

  Performance evaluation was performed by the said method about the adhesive sheet of the said Examples 1-3 and Comparative Examples 1-2, and initial stage adhesive force, adhesive force, holding power, and heat resistance were measured. These measurement results are shown in Table 1.

1 is a ¹ H-NMR chart of a polyester resin obtained in Example 1.

The pressure-sensitive adhesive comprising the novel polyester resin of the present invention can be suitably used particularly as a pressure-sensitive adhesive for electronic parts.

Claims (6)

(A) A polyester resin obtained by polycondensation of a polyol component and (B) a carboxylic acid component, wherein (A) the polyol component contains an alkoxy group-containing diol (a) represented by the general formula (2), and glass A pressure-sensitive adhesive comprising a polyester resin having a transition temperature of −10 ° C. or lower .

(R is a hydrocarbon group having 1 or more carbon atoms, and n is an integer of 1 or more.) (B) The pressure-sensitive adhesive according to claim 1, wherein the carboxylic acid component contains a raw material component having an alkoxy group in the side chain. The pressure-sensitive adhesive according to claim 1 or 2, wherein the number average molecular weight of the polyester resin is 5000 or more. Claim characterized in that it contains hydroxyl and / or carboxyl groups per equivalent contained in the polyester resin, a crosslinking agent in the proportions reactive groups is 0.2 to 10 equivalents included in the crosslinking agent 1-3 The adhesive in any one of. The optical member containing the adhesive in any one of Claims 1-4 . Adhesive sheet on one surface or both surfaces of a support, characterized by comprising a layer comprising the pressure-sensitive adhesive according to claim 1.

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