JP5124903B2 - Polyester resin, aqueous dispersion and adhesive using the same - Google Patents

Description

  The present invention relates to a polyester resin having a small hue change (not easily colored) even when light irradiation is performed, and an aqueous dispersion thereof. In particular, the present invention relates to an adhesive that has excellent adhesion to various substrates and is less likely to cause a decrease in adhesion even under conditions such as outdoor exposure.

  High weather resistance is required for plastic plates used outdoors (for example, plates used for agricultural houses and solariums), and for lighting equipment used indoors. Conventionally, vinyl chloride resin and acrylic resin have been widely used for these applications. However, in consideration of the recent increase in environmental awareness and cost performance, the movement to use polyolefin resins such as polypropylene resins and polyethylene terephthalate resins for such applications. There is. It is natural that these materials used for the parts that are exposed to light are required to have weather resistance, but when assembled and bonded with an adhesive, for example, if the plastic plate is transparent, light is transmitted and the adhesive layer To reach. As a result, yellowing of the adhesive layer may occur and the designability may decrease, or the adhesive strength may decrease with time. As described above, recently, there is an increasing use in which higher weather resistance is required for adhesives.

  Until now, organic solvent-based adhesives have been the mainstream of adhesives used to bond plastic plates used outdoors, but air pollution prevention, regulations under the Fire Service Act, occupational health, etc. From this point of view, water-based adhesives are beginning to be adopted. As the water-based adhesive and paint resin, a polyester-based or polyether-based polyurethane resin containing a hydrophilic polar group such as a carboxylate has been proposed (for example, Patent Documents 1 and 2). reference).

  However, conventional polyester-based water-based polyurethane resins have good adhesion to polyethylene terephthalate and nylon, but are satisfactory for adhesion to non-polar substrates such as polyolefins that have been used in recent years as adherends in the above applications. In addition, the weather resistance was insufficient due to the aliphatic polyester polyol base. Polyether-based ones have insufficient water resistance, durability, weather resistance, and mechanical strength.

  An aqueous polyurethane resin adhesive containing a hydroxyl group-containing hydrogenated polybutadiene has also been proposed (see, for example, Patent Document 3).

  However, this hydroxyl group-containing hydrogenated polybutadiene has an extremely uneven ratio of linear units to side chain units, so that the crystallinity of the polyolefin part becomes too large, and adhesion and adhesion to the resulting water-dispersible polyurethane It does not contribute to sex. Further, since the hydroxyl group-containing polyolefin such as conventional hydroxyl group-containing polybutadiene has a functional group number exceeding 2, the target polyurethane resin itself is difficult to obtain, and the resulting resin also has a double bond remaining in the polybutadiene unit. Therefore, the weather resistance was difficult.

  It has also been proposed to use an aqueous polyester resin dispersion containing aromatic dicarboxylic acid and diethylene glycol as essential components as a paint, ink, or adhesive (see, for example, Patent Document 4).

  However, the inventors of the present application also examined these polyester resins for this application, and were excellent in yellowing resistance at the time of light irradiation. In particular, it was not suitable for adhesive applications such as outdoors.

As described above, various water-based polyester resins and polyurethane resins have been proposed as adhesives intended for outdoor use, but both of them satisfy the problems of initial adhesiveness and deterioration of adhesive strength over time. I could not. In addition, nothing superior in yellowing resistance was known.
Japanese Patent Laid-Open No. 5-117358 ([0006], [0007], etc.) Japanese Patent Laid-Open No. 4-68022 (2 pages, etc.) Japanese Patent Publication No. 5-86829 (2 pages, etc.) JP 57-40525 A (2 pages, etc.)

  The present invention has been made in order to solve the above problems, and the object of the present invention is excellent in adhesion to various substrates including non-polar substrates such as polyolefin resins, particularly in outdoor exposure. It is to provide a polyester resin and an aqueous dispersion thereof, and an adhesive with less adhesive strength and less coloring.

When the total amount of the dicarboxylic acid component and the glycol component is 100 mol%, the polyester resin of the present invention has 30 mol% or more of isophthalic acid as the dicarboxylic acid component and less than 70 mol% of terephthalic acid, and triethylene as the glycol component. The glycol is copolymerized in an amount of 40 mol% or more, and a part of the molecular terminal is succinic acid that is not neutralized with a base.

In the polyester resin of the present invention, when the total amount of the dicarboxylic acid component and the glycol component is 100 mol%, the dicarboxylic acid component having 3 or more carbon atoms bonded in a straight chain is 40 mol% or less. There, and continuous carbon atoms bonded to it three or more glycol components in linear is Ru der than 40 mol%.

In the polyester resin of the present invention, the succinic acid is more preferably 0.1 to 5.0 mol% .

The polyester resin of the present invention preferably has a specific gravity of 1.26 or more .

  The present invention also provides an aqueous dispersion containing any of the polyester resins described above. Such an aqueous dispersion of the present invention is suitably used as an adhesive.

The present invention also provides an adhesive containing the above-described polyester resin of the present invention. The present invention further provides an adhesive comprising the above-described aqueous dispersion of the present invention .

The adhesive of the present invention is preferably an adhesive in which a curing agent is blended in an aqueous dispersion. Curing agent, an isocyanate-based curing agent, the curing agent is Ri isocyanate curing agent der, [NCO] / [OH] is preferably a 0.4 to 40.

  As described above, according to the present invention, there are provided a polyester resin which is excellent in adhesive strength to various substrates, particularly has low adhesive strength when exposed to the outdoors, and is less colored, and an aqueous dispersion and an adhesive using the same. be able to.

  When the total amount of the dicarboxylic acid component and the glycol component is 100 mol%, the polyester resin of the present invention is copolymerized with 30 mol% or more of isophthalic acid as the dicarboxylic acid component and 20 mol% or more of triethylene glycol as the glycol component. It is characterized by being. According to the polyester resin of the present invention having such characteristics, it has excellent adhesion to various substrates including non-polar substrates such as polyolefin, and in particular, there is little decrease in adhesion and coloring when exposed outdoors. In addition, when isophthalic acid is less than 30 mol%, there is a problem that the mechanical strength of the adhesive layer is lowered, and when triethylene glycol is less than 20 mol%, there is a problem that the adhesive strength is reduced, In any case, the object of the present invention cannot be achieved.

  The isophthalic acid used as the dicarboxylic acid component in the polyester resin of the present invention has a mechanical strength without reducing the weather resistance even when an adhesive layer is formed with the polyester resin obtained by copolymerizing this with a glycol component. In order to exhibit the effect of improving the content, it is desirable to increase the content as much as possible. Therefore, in the polyester resin of the present invention, the dicarboxylic acid component preferably contains isophthalic acid in an amount of 50 mol% or more, more preferably 60 mol% or more, and even more preferably 70 mol% or more. The content is particularly preferably at least mol%, and most preferably at least 90 mol%.

  Further, triethylene glycol used as a glycol component in the polyester resin of the present invention can be formed using such a resin, which can lower the glass transition temperature in a polyester resin obtained by copolymerizing it with a dicarboxylic acid component. Adhesive properties can be enhanced in the adhesive layer formed. Furthermore, triethylene glycol also has the effect that the specific gravity of the polyester resin obtained using this is difficult to decrease, and can form an adhesive layer with a high barrier property, which will be described later. Deterioration can be minimized. The main cause of deterioration of the coating film (adhesive layer) due to light irradiation is auto-oxidation due to oxygen in the atmosphere. In order to suppress auto-oxidation, it is necessary to produce a dense cured coating and prevent oxygen permeation (dissolution / diffusion). That is, it is considered that when oxygen is present in the adhesive layer, the above-mentioned crosslinking reaction of active radicals is promoted. In order to reduce the oxygen transmission rate of the adhesive layer, it is effective to increase the specific gravity of the polyester resin to obtain a dense cured coating film. In general, when a polyester resin is used for an adhesive, it is necessary to lower the glass transition temperature (Tg) to increase the paintability and adhesion to the substrate. However, in this case, a method of copolymerizing a dicarboxylic acid component having 3 or more carbon atoms bonded continuously in a straight chain or a glycol component having 3 or more carbon atoms bonded continuously in a straight chain at this time is used. Is nothing but the one that lowers the specific gravity of the coating film and increases the oxygen transmission rate. The present invention has been made on the basis of the knowledge that there exists a polyester resin that retains these contradictory properties by copolymerizing triethylene glycol in the above proportion or more as a result of studies to achieve this high specific gravity and low Tg. It is.

  From the viewpoint of reliably exhibiting the above-described effects, in the polyester resin of the present invention, the triethylene glycol is preferably 20 mol% or more when the total amount of glycol components is 100 mol%, and 40 mol. % Is more preferable, 60 mol% or more is further preferable, and 75 mol% or more is particularly preferable.

  In the polyester resin of the present invention, when the total amount of dicarboxylic acid components is 100 mol%, the copolymerization amount of terephthalic acid is preferably less than 70 mol%. When the copolymerization amount of terephthalic acid is 70 mol% or more, in the coating film formed from the polyester resin obtained by copolymerizing the terephthalic acid with the glycol component, although the mechanical properties are improved, the film is irradiated with light. It may cause yellowing. From this point of view, it is desirable to reduce the copolymerization amount of terephthalic acid in the dicarboxylic acid component of the polyester resin of the present invention as much as possible, more preferably 50 mol% or less, still more preferably 40 mol% or less, more More preferably, it is 20 mol% or less, Especially preferably, it is 10 mol% or less, Most preferably, it is 0 mol%.

  In the polyester resin of the present invention, when the total amount of the dicarboxylic acid component and the glycol component is 100 mol%, 40 mol% of the dicarboxylic acid component having 3 or more carbon atoms bonded in a straight chain is continuously added. It is preferable that the glycol component having 3 or more carbon atoms bonded in a straight chain is 40 mol% or less. If at least one of the dicarboxylic acid component having 3 or more carbon atoms continuously bonded in a straight chain or the glycol component having 3 or more carbon atoms bonded in a straight chain exceeds 40 mol%, It is possible to lower the glass transition temperature of a polyester resin obtained by copolymerizing a dicarboxylic acid component having 3 or more carbon atoms continuously linked in a chain and a glycol component to form a polyester resin. In the adhesive layer formed using resin, the adhesive strength immediately after bonding can be increased, but on the other hand, the three-dimensional crosslinking (gelation) proceeds with long-term light irradiation, and the adhesive layer becomes brittle, resulting in adhesion. There is a possibility of causing a decrease in strength. In the polyester resin of the present invention, the copolymerization amount of the dicarboxylic acid component having 3 or more carbon atoms and the glycol component bonded together in a straight chain is more preferably 30 mol% or less. It is more preferably not more than mol%, particularly preferably not more than 10 mol%, most preferably 0 mol%.

  In the present specification, the term “dicarboxylic acid having 3 or more carbon atoms bonded continuously in a straight chain” refers to those having 3 or more consecutive carbon atoms contained between two carboxyl groups. For example, adipic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, dimer Examples include acids. Of these, adipic acid, sebacic acid, azelaic acid, and dimer acid tend to undergo three-dimensional cross-linking (gelation), particularly when irradiated for a long period of time, and the coating strength tends to decrease.

  In addition, the term “glycol having 3 or more carbon atoms bonded in a straight chain” in the present specification means that the number of continuous carbon atoms contained between two hydroxyl groups is 3 or more. For example, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3 -Methyl-1,5-pentanediol, neopentyl glycol, 2,2,4-trimethyl-1,3-pentanediol, cyclohexanedimethanol, tricyclodecane dimethanol, neopentyl glycol, ethylene oxide adduct of bisphenol A And propylene oxide adduct, hydrogenated bisphenol A ethylene oxide adduct and propylene oxide Side adducts, 1,9-nonanediol, 2-methyloctanediol, 1,10-dodecanediol, 2-butyl-2-ethyl-1,3-propanediol, tricyclodecane dimethanol, dimer diol, etc. It is done. Among these, 2-methyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5 -Pentanediol and neopentyl glycol are particularly prone to three-dimensional crosslinking (gelation) due to light irradiation over a long period of time, and the coating strength tends to decrease.

  In the present invention, as the copolymer component of the polyester resin, if the amount of copolymerization of the dicarboxylic acid component having 3 or more carbon atoms continuously linked in a straight chain and the glycol component is large, the cause of progress of three-dimensional crosslinking of the adhesive layer Although it is not clear, it is likely that a hydrogen abstraction reaction of a methylene group occurs due to light irradiation, an active radical is likely to be generated, and since the specific gravity of the resin is low, oxygen permeability becomes large and auto-oxidation easily proceeds. It is expected that crosslinking will proceed. When thinking so, it is as described above that the number of carbon dicarboxylic acids having 3 or more is small, the three-dimensional crosslinking (gelation) after light irradiation is long, and the coating film adhesive strength is excellent. It is needless to say that better results are obtained when the dicarboxylic acid having 4 or more carbon atoms is more preferable, and the dicarboxylic acid having 6 or more carbon atoms is more preferable, and the experimental results also support this. In addition, as described above, it is more preferable that the number of glycols having 3 or more carbon atoms is small, that three-dimensional crosslinking (gelation) after light irradiation over a long period of time is small and that the coating film adhesive strength is excellent. It goes without saying that better results are obtained when glycols having 4 or more carbon atoms, more preferably less glycols having 6 or more carbon atoms, are used.

  The polyester resin of the present invention is also preferably succinic acid in which a part of molecular ends is not neutralized with a base. When a water-dispersed isocyanate curing agent is blended with an aqueous dispersion of the polyester resin of the present invention, as described later, if the molecular terminal is succinic acid that is not neutralized with a base, the terminal of the polyester resin The hydroxyl group and the isocyanate curing agent react to proceed with the crosslinking reaction, but succinic acid that is not neutralized by the terminal base acts as a reaction catalyst for water and isocyanate, resulting in the formation of a urea conjugate in the system. In addition, there is an effect of mainly improving the adhesive strength immediately after application. Further, after sufficiently aging and proceeding with the crosslinking reaction, a strong crosslinked body is formed by urethane bonds and urea bonds.

  In addition, aromatic acids such as phthalic acid (anhydride, the same applies hereinafter), trimellitic acid and pyromellitic acid are generally known as acids introduced into the molecular terminals of the polyester resin, but aromatic acids have a large catalytic effect. A large amount of urea may be generated in the system, which may reduce the weather resistance. In addition, when an unsaturated acid such as maleic acid is introduced, the unsaturated group is susceptible to photooxidation, and the resin may be significantly deteriorated. In addition, alicyclic acids such as 1,2-cyclohexanedicarboxylic acid are structurally susceptible to oxidation by light and tend to be severely degraded. Therefore, it is effective to obtain an adhesive layer having excellent weather resistance by introducing succinic acid which is less acidic than an aromatic acid and is less susceptible to hydrogen abstraction by radicals generated by light irradiation.

  The succinic acid at the molecular terminals in the polyester resin of the present invention is preferably 0.1 to 5.0 mol%, more preferably 0.2 to 4.0 mol%, and 0.3 to 3. It is more preferably 0 mol%, particularly preferably 0.4 to 2.5 mol%, and most preferably 0.5 to 2.0 mol%. If the succinic acid at the molecular end is less than 0.1 mol%, the formation of urea bonds is less and the adhesive strength immediately after coating tends to be low, and the succinic acid at the molecular end is less than 5.0 mol%. If it exceeds, succinic acid monomer that is not copolymerized in the polyester resin remains in the system, the adhesive strength is reduced, and the hydroxyl terminal of the polyester is reduced, so that the crosslinking reaction by isocyanate is insufficient, The mechanical strength of the adhesive layer tends to be low.

  As described above, when the total amount of the dicarboxylic acid component and the glycol component is 100 mol%, the polyester resin of the present invention has 50 mol% or more of isophthalic acid as the dicarboxylic acid component and 20 mol of triethylene glycol as the glycol component. If it is what is copolymerized more than%, the raw material will not be restrict | limited in particular, A various thing can be used.

  Examples of the dicarboxylic acid used in the polyester resin of the present invention include orthophthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, 4,4′-diphenyldicarboxylic acid, 2,2′-diphenyldicarboxylic acid, 4, Aromatic dibasic acids such as 4′-diphenyl ether dicarboxylic acid, fumaric acid, maleic acid, itaconic acid and the like can be mentioned. Examples of the polyvalent carboxylic acid component include trimellitic anhydride and pyromellitic anhydride.

  As the glycol component used in the polyester resin of the present invention, diols such as ethylene glycol, 1,2-propylene glycol, 1,2-butanediol, diethylene glycol and dipropylene glycol, and polyhydric alcohols such as trimethylolpropane are used. it can.

Examples of the method for determining the composition and composition ratio of the polyester resin of the present invention include ¹ H-NMR and ¹³ C-NMR in which the polyester resin is dissolved in a solvent such as deuterated chloroform, and gas chromatography that is measured after the methanolysis of the polyester resin. For example, quantitative determination by graph. Of these, ¹ H-NMR is convenient and preferred.

  The polyester resin of the present invention can be produced by various conventionally known methods. For example, the target polyester resin can be obtained by transcondensation of the above dicarboxylic acid and diol components at 230 to 300 ° C. while reducing the pressure after transesterification at 150 to 250 ° C.

  Further, as a method for efficiently and quantitatively introducing succinic acid to the molecular terminal, a method of adding succinic anhydride under a nitrogen atmosphere after the polycondensation is effective.

The number average molecular weight of the polyester resin of the present invention is not particularly limited, but the lower limit is preferably 5000 or more, and more preferably 7000 or more. If the lower limit of the number average molecular weight is less than 5000, the cohesive force of the adhesive layer becomes a somewhat insufficient, the adhesive strength is in want cormorants tends to decrease when used as an adhesive. Further, the upper limit of the number average molecular weight of the polyester resin of the present invention is preferably 40000 or less, more preferably 30000 or less, and further preferably 25000 or less. When the upper limit of the number average molecular weight exceeds 40000, it tends to be difficult to produce an aqueous dispersion described later. The number average molecular weight can be measured using gel permeation chromatography with polystyrene as a standard substance.

  Further, the specific gravity of the polyester resin of the present invention is not particularly limited, but is preferably 1.26 or more and more preferably 1.27 or more from the viewpoint of lowering the oxygen transmission rate. . Further, the upper limit of the specific gravity in the polyester resin of the present invention is preferably as high as possible. However, if it is too high, it becomes difficult to stably produce an aqueous dispersion, so that it is preferably less than 1.34, more preferably 1 Less than 32.

  In addition, the upper limit of the glass transition temperature of the polyester resin of the present invention is preferably 40 ° C. or less, more preferably 30 ° C. or less, and preferably 20 ° C. or less in order to obtain substrate adhesion. More preferably, it is 10 ° C. or less. On the other hand, the lower limit of the specific gravity in the polyester resin of the present invention is preferably as low as possible, but if it is too low, it becomes difficult to stably produce the polyester resin and the aqueous dispersion. Preferably it is -50 ° C or more.

  Further, the polyester resin of the present invention may be modified with urethane, epoxy, acrylic or the like.

  As will be described later, the polyester resin of the present invention is preferably provided as an aqueous dispersion containing the polyester resin. For this purpose, it is preferable that a hydrophilic polar group is introduced into the polyester resin. Examples of such a polar group having hydrophilicity include a sulfonic acid metal base, a carboxyl group, an ether group, and a phosphoric acid group. Among them, it is easy to introduce a resin into a polyester and easily disperse in water. A sulfonic acid metal salt, a carboxyl group, and an ether group having a high ability to be used are preferable. The polar group having hydrophilicity can be introduced into the polyester resin of the present invention alone or in combination.

  When introducing the sulfonic acid metal base into the molecule, for example, 5-Na sulfoisophthalic acid, 5-ammonium sulfoisophthalic acid, 4-Na sulfoisophthalic acid, 4-methylammonium sulfoisophthalic acid, 2-Na sulfoterephthalic acid, 5-K sulfoisophthalic acid, 4-K sulfoisophthalic acid, 2-K sulfoterephthalic acid, Na sulfosuccinic acid and other sulfonic acid alkali metal salt compounds or sulfonic acid amine salt compounds, sulfonic acid Na salt-containing bisphenol A-alkylene oxide It can introduce | transduce into the molecule | numerator of a polyester resin by copolymerizing an adduct, a sulfonic-acid K base containing hydroquinone alkylene oxide adduct, etc.

  In the case of introducing a carboxyl group into the molecule, examples of the introduction method include a method of grafting a vinyl monomer having a carboxyl group onto a polyester in addition to a method of adding an acid anhydride. At this time, as the dicarboxylic acid component of the polyester resin, it is particularly preferable to use one containing an unsaturated bond such as dimer acid, fumaric acid, maleic acid or itaconic acid because the grafting efficiency is increased. Examples of the vinyl monomer having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, and the like. And maleic anhydride. As the vinyl monomer having a carboxyl group, one or more selected from the above can be used. Furthermore, in order to increase the polymerization efficiency, other non-hydrophilic vinyl monomers such as acrylic acid ester, methacrylic acid ester, styrene, vinyl acetate and the like may be used as a copolymerization component. In the polyester resin in which the carboxyl group is introduced into the molecule, the unreacted carboxyl group is neutralized with an amino compound, ammonia, an alkali metal, or the like.

  When introducing an ether group into the molecule, for example, diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, neopentyl glycol ethylene oxide adduct, neopentyl glycol propylene oxide adduct, etc. By using an ether bond-containing glycol, it can be introduced into the molecule of the polyester resin.

  In this invention, the adhesive agent containing the polyester resin of this invention which has the characteristics as mentioned above is also provided. By using the polyester resin of the present invention as an adhesive, it has excellent adhesion to various substrates including non-polar substrates such as polyolefin resins, and in particular, an adhesive with reduced adhesion and less coloring when exposed outdoors. Can be provided.

  The present invention also provides an aqueous dispersion comprising any of the polyester resins described above. The aqueous dispersion of the present invention can be produced by a conventionally known appropriate method. For example, after the polyester resin of the present invention described above is dissolved in an organic solvent having a boiling point higher than that of water such as butyl cellosolve, diethylene glycol methyl ether, propylene glycol-n-propyl ether, etc., it is produced by adding warm water and dispersing in water. be able to. Alternatively, an aqueous dispersion can be produced by directly dissolving / dispersing in a mixed solvent of water and a polar solvent such as butyl cellosolve, methyl ethyl ketone, and isopropyl alcohol. Further, in a system dissolved / decomposed using a solvent having a boiling point lower than that of water, a completely aqueous aqueous dispersion can be obtained by distilling off the organic solvent.

  The aqueous dispersion of the present invention is suitably used as an adhesive by adding a curing agent. The present invention also provides an adhesive comprising such an aqueous dispersion and a curing agent. As the curing agent used in the adhesive of the present invention, various curing agents such as melamine-based, benzoguanamine-based, isocyanate-based, oxazoline-based, epoxy-based, phenol-based and the like can be used. Can be cured at a low temperature, and even if the adherend is an olefin resin-based substrate, high adhesive strength can be obtained without impairing the adhesive strength.

  Examples of the isocyanate curing agent include aromatic and aliphatic diisocyanates and trivalent or higher polyisocyanates, and any of low molecular compounds and high molecular compounds may be used. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmetaxylylene diisocyanene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate or trimers of these isocyanate compounds, and these isocyanate compounds Excess amount and low molecular active hydrogen compounds such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine or various polyester polyols, polyether polyols, polyamides To react with other polymer active hydrogen compounds Terminal isocyanate group-containing compound obtained may be mentioned.

  The isocyanate curing agent may be a blocked isocyanate. Examples of the isocyanate blocking agent include phenols such as phenol, thiophenol, methylthiophenol, cresol, xylenol, resorcinol, nitrophenol, and chlorophenol, oximes such as acetoxime, methyl ethyl ketoxime, and cyclohexanone oxime, methanol, ethanol, propanol, Alcohols such as butanol, halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol, tertiary alcohols such as t-butanol and t-pentanol, ε-caprolactam, δ-valero And lactams such as lactam, γ-butyrolactam, and β-propyllactam. In addition, aromatic amines, imides, acetylacetone, acetoacetate, Active methylene compounds such as phosphate ester, mercaptans, imines, ureas, and also such as diaryl compounds sodium bisulfite. The blocked isocyanate is obtained by subjecting the above isocyanate compound and an isocyanate blocking agent to an addition reaction by a conventionally known appropriate method.

  In the adhesive of the present invention, in order to achieve a high degree of weather resistance, it is preferable that the isocyanate curing agent to be used is aliphatic. Moreover, since it mix | blends with the polyester resin aqueous dispersion, when the usable time of a coating liquid after mixing | blending is considered, the block type or the water-dispersion type (thing which modified the isocyanate compound with polyether etc.) is preferable. . In the block type, the base material is maintained under a high temperature condition of 100 ° C. or higher in order to remove the blocking agent, and the base material is formed of an olefin resin such as OPP (biaxially oriented polypropylene film). The water-dispersed type is preferable because it is unsuitable for use and is subject to use restrictions due to the substrate. Polyethylene glycol modified product of hexamethylene diisocyanate trimer compound has good compatibility with polyester aqueous dispersion, long usable time, high adhesive strength, and high weather resistance and durability Is particularly preferable.

  [NCO] / [OH] (molar ratio) is preferably 0.3 to 40, and preferably 0.5 to 30 in the amount of the aqueous dispersion and the isocyanate curing agent in the adhesive of the present invention. Is more preferable, 0.7-20 is further more preferable, and 0.9-15 is particularly preferable. When the above [NCO] / [OH] is less than 0.3, the crosslinking effect is insufficient and there is a possibility that sufficient adhesive strength cannot be obtained. On the other hand, if the above [NCO] / [OH] exceeds 40, unreacted isocyanate curing agent remains in the system, and there is a risk that the weather resistance, water resistance, etc. will be lowered.

  When a non-blocking type isocyanate curing agent is used, the reactivity with polyester-derived OH groups is high, and a cured coating film can be obtained by aging the aqueous dispersion at room temperature. When heat is further applied, the curing reaction proceeds and high adhesive strength can be obtained. When a block type isocyanate curing agent is used, it is preferable to heat at 100 ° C. or higher, more preferably 120 ° C. or higher, and even more preferably 150 ° C. or higher.

  The aqueous dispersion and adhesive of the present invention can be adjusted to a viscosity and viscosity suitable for workability by using various thickeners. From the stability of the system due to the addition of a thickener, nonionic ones such as methylcellulose and polyalkylene glycol derivatives, and anionic ones such as polyacrylates and alginates are preferred.

  The aqueous dispersion and adhesive of the present invention can further improve applicability by using various surface tension adjusting agents. Examples of the surface tension adjusting agent include acrylic, vinyl, silicone, and fluorine surface tension adjusting agents, and are not particularly limited. And vinyl surface tension modifiers are preferred. In order not to impair the adhesive strength, the surface tension modifier should preferably be added to the resin in an amount of preferably 1 wt% or less, more preferably 0.5 wt% or less.

  The aqueous dispersion and adhesive of the present invention can be colored using various dyes and pigments. Examples of dyes include azo dyes, anthraquinone dyes, indigoid dyes, and examples of pigments include carbon black, titanium oxide, molybdate orange, bengara, chrome green, cobalt blue, phthalocyanine blue, and the like. Is done. Especially, it is preferable to color an aqueous dispersion using a pigment from a viewpoint of a weather resistance and light resistance.

  The aqueous dispersion and adhesive of the present invention can be further improved in weather resistance by adding various ultraviolet absorbers, antioxidants, and light stabilizers. Light resistance is greatly improved by introducing a compound having an ultraviolet absorption effect and a light stabilization effect into the polyester skeleton, but an ultraviolet absorber, an antioxidant, an emulsion of a light stabilizer, and an aqueous solution are dispersed in a polyester resin in water. Addition to the body also improves the weather resistance. As the ultraviolet absorber, various organic types such as benzotriazole, benzophenone, and triazine, and inorganic types such as zinc oxide can be used. As the antioxidant, various polymers generally used for polymers such as hindered phenols, phenothiazines and nickel compounds can be used. Various light stabilizers for polymers can be used, but hindered amines are effective.

  In order to describe the present invention in more detail, examples are given below, but the present invention is not limited to the examples. In addition, the measured value described in the Example is measured by the following method.

(1) Initial adhesive strength A method for preparing a sample for measuring adhesive strength will be described below. First, an aqueous dispersion / curing agent mixture (polyester resin: curing agent = 100: 30 [solid weight ratio], Takenate WD-730 (manufactured by Mitsui Takeda Chemical Co., Ltd.) was used as the curing agent), and biaxially oriented polypropylene. After applying 5 g / m ² (weight after drying) to the corona surface of a sheet (OPP) (pyrene (Toyobo Co., Ltd.), thickness 50 μm), it was dried with an air dryer at 60 ° C. for 30 seconds. The same OPP corona surface as described above was bonded to the coated surface in a state where moisture was lost, and roll lamination (60 cm / min) was performed at 60 ° C. and 30 Pa. After the obtained sample was stored at room temperature for 6 hours, T-type adhesive strength was measured with a tensile tester (manufactured by Orientec).

(2) Normal adhesive strength After aging the sample obtained by the method (1) above at 40 ° C. for 48 hours, T-type adhesive strength was measured with a tensile tester.

(3) Yellowing test After 5 g / m ² (dry weight) of the aqueous dispersion was applied to the OPP corona surface, it was dried with an air dryer at 120 ° C. for 30 minutes, and then the weather resistance tester iSuper UV Tester SUV- The degree of coloration of the coating film after UV irradiation (100 mW / cm ² , 63 ° C., 50% RH, 45 hours continuous irradiation) was visually determined with W151 (Iwasaki Electric Co., Ltd.).

    A: Good. Colorless and transparent.

    ○: Yellowish slightly.

    Δ: Severe yellowing is observed.

    X: A coating film deteriorates and a fracture | rupture is seen.

(4) Weather resistance (strength) test The sample for adhesive strength measurement prepared in the above (1) was irradiated with ultraviolet rays under the same conditions as the yellowing test of (3), and the adhesive strength after irradiation was measured.

(5) Polyester resin composition Determined by ¹ H-NMR analysis using a nuclear magnetic resonance analyzer (NMR) Gemini-200 (manufactured by Valian) in a deuterated chloroform solvent.

(6) Polyester resin molecular weight Calculated from the results of GPC measurement using a gel filtration permeation chromatography (GPC) 150c (manufactured by Waters) with tetrahydrofuran as an eluent at a column temperature of 35 ° C. and a flow rate of 1 ml / min. Thus, a measured value in terms of polystyrene was obtained. However, shodex KF-802, 804, 806 (manufactured by Showa Denko KK) was used as the column.

(7) Polyester acid value 0.2 g of polyester resin was dissolved in 20 ml of chloroform, and titrated with 0.1N potassium hydroxide ethanol solution using phenolphthalein as an indicator. Equivalent per 10 ⁶ g of resin (eq / 10 ⁶ g) was determined.

(8) Glass transition temperature (Tg) of polyester resin
5 mg of a polyester resin sample is put in an aluminum sample pan, sealed, and measured using a differential scanning calorimeter (DSC) DSC-220 (manufactured by Seiko Instruments Inc.) at a heating rate of 20 ° C./min. Was determined by

(9) Specific gravity of polyester resin Polyester resin without bubbles was cut into 3 mm x 3 mm x 3 mm cubes and measured in an aqueous calcium chloride solution adjusted to 30 ° C. After adjusting the concentration of calcium chloride so that the polyester resin stays in the middle from the liquid level to the bottom of the aqueous solution, the specific gravity of the aqueous calcium chloride solution was measured with a hydrometer to obtain the specific gravity of the polyester resin.

Example 1
(1) Production Example of Polyester Resin In a reaction can equipped with a stirrer, a thermometer, and a condenser for distillation, 159 parts by weight of isophthalic acid, 12 parts by weight of 5-Na sulfoisophthalic acid, 135 parts by weight of triethylene glycol, 37 parts by weight of ethylene glycol, 0.1 parts by weight of tetrabutyl titanate as a catalyst, 0.2 parts by weight of sodium acetate as a polymerization stabilizer, and 2 parts by weight of Irganox 1330 (manufactured by Ciba Geigy) as an antioxidant are added, and 170 to 230 The esterification reaction was carried out at 2 ° C. for 2 hours. After completion of the esterification reaction, the temperature of the reaction system was raised from 230 ° C. to 270 ° C., while the pressure inside the system was slowly reduced to 5 Torr at 270 ° C. over 60 minutes. Further, a polycondensation reaction was carried out at 1 Torr or less for 30 minutes. After completion of the polycondensation reaction, the vacuum was broken under a nitrogen atmosphere, 1 part by weight of succinic anhydride was added at 200 ° C., and the mixture was stirred for 30 minutes to complete the addition reaction, whereby a polyester resin (A) was obtained.

  As for the polyester resin (A), as a result of NMR analysis, the dicarboxylic acid component was 96 mol% isophthalic acid, 4 mol% 5-Na sulfoisophthalic acid, the diol component was 20 mol% diethylene glycol, 80 mol% triethylene glycol, and terminal addition acid. The component had a composition of 1 mol% succinic acid. The measurement results are shown in Table 1 together with other resin physical properties.

(2) Production Example of Water Dispersion 35 parts by weight of polyester resin (A), 18 parts by weight of isopropyl alcohol, and 47 parts by weight of water were added to a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser. By stirring for 3 hours, an aqueous dispersion (A-1) was obtained.

  For 100 parts by weight of the aqueous dispersion (A-1), further, 0.3 part by weight of a polymer ultraviolet absorber ULS-1700 (manufactured by Yushi Kogyo Co., Ltd.), emulsion type hindered amine light stabilizer ADK STAB LX- After adding 0.04 part by weight of 335 (manufactured by Asahi Denka Kogyo Co., Ltd.) and stirring, the mixture was filtered with a 200 mesh nylon filter to obtain an aqueous dispersion (A-2).

  Using this aqueous dispersion, the properties as an adhesive were measured using the above method, and the results are shown in Table 1.

実施例２〜４、参考例１、２
表１に示す原料を用いて実施例１と同様な方法でポリエステル樹脂（Ｂ）、（Ｃ）、（Ｄ）、（Ｅ）、（Ｆ）を合成し、水分散体（Ｂ−１）、（Ｂ−２）、（Ｃ−１）、（Ｃ−２）、（Ｄ−１）、（Ｄ−２）、（Ｅ−１）、（Ｅ−２）、（Ｆ−１）、（Ｆ−２）を作製した。評価結果を表１に示す。

Examples 2 to 4 , Reference Examples 1 and 2
Polyester resins (B), (C), (D), (E), (F) were synthesized in the same manner as in Example 1 using the raw materials shown in Table 1, and the water dispersion (B-1), (B-2), (C-1), (C-2), (D-1), (D-2), (E-1), (E-2), (F-1), (F -2). The evaluation results are shown in Table 1.

Comparative Examples 1-5
Polyester resins (G), (H), (I), (J) and (K) were synthesized in the same manner as in Example 1 using the raw materials shown in Table 1, and the water dispersion (G-1), (G-2), (H-1), (H-2), (I-1), (I-2), (J-1), (J-2), (K-1), (K -2). The evaluation results are shown in Table 2.

比較例１〜３は、グリコール成分としてトリエチレングリコールが共重合されておらず、本発明の対象から外れる。

In Comparative Examples 1 to 3, triethylene glycol is not copolymerized as a glycol component, and is excluded from the subject of the present invention.

  In Comparative Example 4, the isophthalic acid as the dicarboxylic acid component is less than 30 mol%, which is not the subject of the present invention.

  In Comparative Example 5, triethylene glycol as the glycol component is less than 20 mol%, and is out of the scope of the present invention.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Claims (9)

When the total amount of the dicarboxylic acid component and the glycol component is 100 mol%, isophthalic acid is 30 mol% or more and terephthalic acid is less than 70 mol% as the dicarboxylic acid component, and triethylene glycol is 40 mol% or more as the glycol component. Succinic acid that is polymerized and part of the molecular ends are not neutralized with a base ,
When the total amount of the dicarboxylic acid component and the glycol component is 100 mol%, the dicarboxylic acid component having 3 or more carbon atoms bonded continuously in a straight chain is 40 mol% or less and continuous in a straight chain. A polyester resin in which the glycol component having 3 or more carbon atoms bonded thereto is 40 mol% or less . The polyester resin according to claim 1, wherein the succinic acid is 0.1 to 5.0 mol%. The polyester resin according to claim 1 or 2 , wherein the specific gravity is 1.26 or more. The water dispersion containing the polyester resin in any one of Claims 1-3 . The aqueous dispersion according to claim 4 , wherein the aqueous dispersion is used as an adhesive. The adhesive agent containing the polyester resin in any one of Claims 1-3 . An adhesive comprising the aqueous dispersion according to claim 4 or 5 . The adhesive according to claim 7 , further comprising a curing agent added to the aqueous dispersion according to claim 4 or 5 . The adhesive according to claim 8 , wherein the curing agent is an isocyanate curing agent, and [NCO] / [OH] is 0.4 to 40.