JPWO2009054430A1 - Resin composition, adhesive, paint and coating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily produce a highly cross-linked structure in the field of polyester resin adhesives and compositions, and to improve problems such as hydrolysis resistance, resin protrusion and blocking properties at a high level. It is. An adhesive comprising 0.5 to 50 parts by weight of a curing agent and 0.1 to 40 parts by weight of a resin having a hydroxyl value of 100 to 1000 mgKOH / g as essential components with respect to 100 parts by weight of a polyester resin The present invention relates to a resin composition. Preferably, the present invention relates to the above adhesive and resin composition, wherein the curing agent is a polyfunctional isocyanate compound. [Selection figure] None

Description

  The present invention relates to an adhesive and a resin composition using a polyester resin. More specifically, the present invention relates to an adhesive that has a high curing rate and remarkably improves adhesion. Similarly, it relates to a resin composition having a high curing rate.

  The polyester resin is known to have good adhesiveness to plastics such as metal, vinyl chloride and polyethylene terephthalate (hereinafter sometimes abbreviated as PET). Utilizing such characteristics, polyester resins are widely used in various applications as main agents such as adhesives, pressure-sensitive adhesives, coating agents, and paints.

  Polyester resin can easily change various properties including glass transition temperature (hereinafter sometimes abbreviated as Tg) by selecting its copolymerization component, and can be dissolved in a general-purpose solvent. Can do. By utilizing this copolymerization technique, various required characteristics in various applications can be satisfied.

  However, for example, low Tg amorphous polyester resin has good adhesion to the substrate, but when used as a surface coating layer, it causes blocking, or when used as an intermediate adhesive layer, the resin protrudes. In many cases, it has a practical problem such as poor hydrolysis resistance. Therefore, an isocyanate compound, a melamine compound, a phenol compound, an epoxy resin, etc. are blended as a curing agent and thermally cured, or a double bond is introduced into a polyester resin and a reactive diluent is used in combination with ultraviolet rays (hereinafter abbreviated as UV). Crosslinking methods such as curing and electron beam curing have been reported. The composition cross-linked by such a method improves the initial adhesiveness, can maintain the adhesiveness for a long time, improves the durability to acids, alkalis, detergents, solvents, etc., that is, improves the chemical resistance, and improves the moisture resistance. It is known that various properties such as heat resistance can be improved.

  Among these methods, the UV curing and electron beam curing methods have the advantage that the crosslinking reaction is completed instantaneously, but the resin production is multi-step and costly, and the UV irradiation device and the electron beam irradiation device In addition, there is a risk that the resin may be damaged by irradiation with high energy rays, and the base material needs to be light transmissive, so it cannot be used for opaque materials. There are limited applications that can be used. On the other hand, although thermosetting is used in many applications in that a crosslinked product can be easily obtained simply by raising the temperature, the time required for the crosslinking reaction is short and several minutes long. Things that take several days are not uncommon, and improvements in productivity were also necessary. In order to increase the reaction rate, it is common to increase the temperature from the point of reacting with heat, but the resin deteriorates at too high a temperature, which is counterproductive, and if the substrate is a plastic material. For example, the temperature cannot be higher than the heat resistance temperature of the substrate.

  Furthermore, since the hydroxyl group that is the crosslinking reaction point of the polyester resin generally exists only at the end of the molecule, increasing the molecular weight of the polyester resin to further improve the properties of the composition itself reduces the reaction point. It will be. Therefore, in compositions and adhesives using high molecular weight polyester resins as the main agent, the reactivity with curing agents tends to be further reduced, making it more difficult to solve the properties required for various applications. .

JP-A-11-166166 JP 2000-319363 A

  The present invention makes it possible to easily produce a highly cross-linked structure in the field of polyester resin adhesives and compositions, and attempts to improve problems such as hydrolysis resistance, resin protrusion, and blocking properties at a high level. Is.

  As a result of intensive studies in order to solve the above problems, the present inventors have completed the present invention. That is, the present invention has the following features.

(1) A resin composition containing, as essential components, 0.5 to 50 parts by weight of a curing agent and 0.1 to 40 parts by weight of a resin having a hydroxyl value of 100 to 1000 mgKOH / g with respect to 100 parts by weight of a polyester resin.
(2) The resin composition according to (1), wherein the curing agent is a polyfunctional isocyanate compound.
(3) The resin composition according to (1) or (2), wherein the resin having a hydroxyl value of 100 to 1000 mgKOH / g is a hyperbranched polymer.
(4) The resin composition according to (1) or (2), wherein the resin having a hydroxyl value of 100 to 1000 mgKOH / g is polyglycerin.
(5) Adhesive containing the resin composition as described in (1)-(4).
(6) A paint containing the resin composition according to any one of (1) to (4).
(7) Coating agent containing the resin composition as described in (1)-(4).

  The composition using the polyester resin of the present invention can obtain a high degree of crosslinking, that is, a high gel fraction regardless of the molecular weight of the polyester. And has the excellent advantage of being applicable.

Hereinafter, the present invention will be described in detail.
The polyester resin used in the present invention is not particularly limited in composition, but is preferably a polyester resin that is soluble in a general-purpose solvent such as methyl ethyl ketone, toluene, cyclohexanone, and ethyl acetate. Furthermore, from the viewpoint of adhesiveness and curing rate, it is preferably amorphous and has a glass transition temperature (Tg) of −50 ° C. or higher and 10 ° C. or lower. There is no problem even if the polyester resin is water dispersible.

  The polyester resin used in the present invention can be obtained by a condensation reaction between a dibasic acid or an esterified product thereof and glycol, a ring opening reaction of a cyclic ester, or the like.

  Examples of the dibasic acid component include aromatic dibasic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenyletherdicarboxylic acid, succinic acid, adipine Acids, azelaic acid, sebacic acid, dodecanedicarboxylic acid, dimer acid, cyclohexanedicarboxylic acid, saturated aliphatic or alicyclic dicarboxylic acids such as tetrahydrophthalic anhydride, fumaric acid, maleic acid, maleic anhydride, itaconic acid, Examples thereof include unsaturated dicarboxylic acids such as citraconic acid and 2,5-norbornene dicarboxylic acid anhydride. Aromatic oxycarboxylic acids such as p-oxybenzoic acid and p- (hydroxyethoxy) benzoic acid can also be used. These dibasic acids may be methyl esterified. These may be used alone or in combination.

  Examples of the glycol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, 3- Methylpentanediol, 1,6-hexanediol, nonanediol, methyloctanediol, neopentyl glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 2-butyl-2-ethyl-1,3-propanediol, 2,2 , 4-Trimethyl-1,5-pentanediol, cyclohexanedimethanol, dimerdiol, neopentylglycol hydroxypivalate, ethylene oxide adduct and propylene oxide adduct of bisphenol A, hydrogenated bisphenol Ethylene oxide adducts and propylene oxide adducts and the like, may be used these alone or may be used in combination.

  Further, high molecular weight glycols such as polyethylene glycol, polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol, polycaprolactone, and polycarbonate may be copolymerized.

  Furthermore, after the polyester is polymerized, it can be modified by adding a lactone or an acid anhydride compound.

  Copolyesters used in the present invention include dicarboxylic acid components and glycol components other than those described above, such as 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, sodium sulfoterephthalic acid, 2-sodium sulfo-1,4-butane. A sulfonic acid metal salt such as diol and 2,5-dimethyl-3-sodium sulfo-2,5-hexanediol may be copolymerized as long as the effects of the invention are not impaired. Copolymerizing a component containing a sulfonic acid metal base with the copolymerized polyester has the effect of significantly improving the dispersibility of inorganic particles such as titanium oxide, talc, pigment, magnetic powder, abrasive, and carbon black.

  Further, a trifunctional or higher functional compound such as trimellitic anhydride, glycerin, trimethylolpropane, pentaerythritol may be used as a part of the raw material of the copolyester used in the present invention.

  Furthermore, lactones and lactams can be copolymerized in the above-mentioned condensation-type polyester resin, or a polyester resin formed by a lactone ring-opening reaction may be used as it is.

  As a hardening | curing agent used for this invention, an isocyanate compound, an epoxy compound, an acid anhydride compound, a melamine compound, a phenol resin, etc. are mentioned. Among these, the isocyanate compound is preferable in that it can be cured at a low temperature. The isocyanate compound is more preferably a trifunctional or higher polyfunctional isocyanate.

  Examples of the isocyanate compound include aromatic, aliphatic, and alicyclic diisocyanates, and trivalent or higher polyisocyanates, which may be either low molecular compounds or high molecular compounds. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate or trimers of these isocyanate compounds, and excess of these isocyanate compounds Amount of 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 Reacts with polymer active hydrogen compounds Allowed include terminal isocyanate group-containing compounds obtained.

  The isocyanate compound 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 Examples include lactams such as lactam, γ-butyrolactam, and β-propiolactam. 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 can be obtained by subjecting the above isocyanate compound and an isocyanate blocking agent to an addition reaction by a conventionally known appropriate method.

  Examples of epoxy compounds include diglycidyl ether of bisphenol A and oligomers thereof, diglycidyl ether of hydrogenated bisphenol A and oligomers thereof, orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, and p-oxybenzoic acid diacid. Glycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1 , 4-Butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether and polyalkylene glycol Cole diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether , Pentaerythritol tetraglycidyl ether, triglycidyl ether of glycerol alkylene oxide adduct, and the like.

  Examples of the acid anhydride compound include pyromellitic anhydride, cyclohexane-1,2,3,4-tetracarboxylic acid-3,4-anhydride, ethylene glycol bisanhydro trimellitate, 5- (2,5- Dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, naphthalene-1,8: 4,5-tetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride Etc.

  Examples of the melamine compound include formaldehyde or paraformaldehyde alkylated with an alcohol having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, and n-butanol, urea, N, N-ethylene urea, Condensation products with dicyandiamide, aminotriazine and the like, methoxylated methylol-N, N-ethyleneurea, methoxylated methylol dicyandiamide, methoxylated methylol benzoguanamine, butoxylated methylol benzoguanamine, methoxylated methylol melamine, butoxylated methylol melamine, methoxy And butoxylated mixed methylol melamine, butoxylated methylol benzoguanamine and the like.

  Examples of the phenol resin include formaldehyde condensates of alkylated phenols and cresols. Specifically, alkylated (eg, methyl, ethyl, propyl, isopropyl, butyl) phenol, p-tert-amylphenol, 4, 4′-sec-butylidenephenol, p-tert-butylphenol, o-, m-, Formaldehyde condensation such as p-cresol, p-cyclohexylphenol, 4,4'-isopropylidenephenol, p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, phenyl-o-cresol, p-phenylphenol, xylenol Things.

  The blending amount of these curing agents is desirably 50 parts by weight or less, more preferably 40 parts by weight or less with respect to 100 parts by weight of the polyester resin. The lower limit is preferably 0.5 parts by weight or more when the effect is exhibited.

  Further, a catalyst may be added to increase the reactivity of these curing agents. Examples of the curing catalyst include tin-based and zinc-based other organic metal compounds, amines, Lewis acids, and alkaline compounds. When polyisocyanate or its block is used as a curing agent, among these curing catalysts, tin-based ones are preferable for controlling the reaction. As the tin-based curing catalyst, dibutyltin dilaurate is preferable in view of versatility. The lower limit is 0.01 parts by weight, preferably 0.03 parts by weight, with respect to 100 parts by weight of the curing agent. On the other hand, the upper limit is 20 parts by weight, preferably 10 parts by weight. If it is less than 0.01 part by weight, the effect as a curing catalyst may not be obtained. On the other hand, if it exceeds 20 parts by weight, the catalytic effect is saturated and it is not economical.

  In the high hydroxyl value resin used in the present invention, the hydroxyl value is preferably 100 to 1000 mgKOH / g. If it is less than 100 mgKOH / g or exceeds 1000 mgKOH / g, the contribution to curability is reduced. The optimum hydroxyl value varies depending on the hydroxyl value of the polyester resin and the amount of the functional group of the curing agent, but is more preferably 300 to 700 mgKOH / g.

  The resin having a hydroxyl value of 100 to 1000 mgKOH / g used in the present invention is not particularly limited in its structure, and if the hydroxyl value is within a predetermined range, it contributes to improvement of curability. Among these resins, polyglycerin and dendritic polymers (hyperbranched polymers and dendrimers) are particularly preferable. Among the dendritic polymers, a hyperbranched polymer is particularly preferable in terms of cost.

Hyperbranched polymer can be used in the present invention preferably is not particularly limited in its structure to the polycondensation reaction or main skeletons those obtained by polyaddition reaction of AB _X type compound. Here, A and B represent organic groups having different functional groups, and the AB _X type compound means a compound having two different functional groups a and b in one molecule. These AB _X- type compounds do not undergo an intramolecular condensation reaction or an intramolecular addition reaction, but the functional group a and the functional group b are functional groups capable of chemically condensing or adding to each other. The hyperbranched polymer that can be used in the present invention preferably has an ester bond in the core portion, and the functional group a and the functional group b are preferably a carboxyl group or a derivative thereof and a combination of a hydroxyl group or a derivative thereof. Carboxyl group: hydroxyl group (molar ratio) = 0.01 to 5:95 to 99.99, and a hydroxyl group closer to 100% is preferable.

Specific examples of the AB _x- type compound include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, diphenolic acid, 5- (2-hydroxyethoxy) isophthalic acid, and 5-acetoxyisophthalic acid. 3,5-bis (2-hydroxyethoxy) benzoic acid, 3,5-bis (2-hydroxyethoxy) benzoic acid methyl ester, 4,4- (4′-hydroxyphenyl) pentanoic acid, 5-hydroxycyclohexane- 1,3-dicarboxylic acid, 1,3-dihydroxy-5-carboxycyclohexane, 5- (2-hydroxyethoxy) cyclohexane-1,3-dicarboxylic acid, 1,3- (2-hydroxyethoxy) -5-carboxycyclohexane From the versatility of these raw material compounds and the simplicity of the polymerization reaction process, 2 2-dimethylolpropionic acid, 2,2-dimethylol butanoic acid are preferred.

  Among these, a polyester-based hyperbranched polymer in which an ester bond is generated by the reaction is preferable because it is excellent in compatibility with the main polyester resin and tends to increase the properties of the cured product. In particular, a hyperbranched polymer composed of an aliphatic monomer is preferred because it tends to be more compatible. Examples of polyester-based hyperbranched polymers made of aliphatic monomers include BOLTORN H20 and H40 manufactured by PERSTROP.

In the above reaction, an AB _X- type compound may be reacted alone in the presence of a condensation reaction catalyst, or a polyhydric hydroxy compound, a polyvalent carboxylic acid compound, or a compound having both of them is branched into a hyperbranched polymer molecule. It may be used as a point. Examples of the polyvalent hydroxy compound include various glycol compounds generally used as polyester resin raw materials and trifunctional or higher functional hydroxyl group-containing compounds such as trimethylolpropane, pentaerythritol, and dipentaerythritol. In addition, as the polyvalent carboxylic acid compound, trifunctional or higher functional carboxylic acid compounds such as various dibasic acids, trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid and the like which are commonly used as polyester resin raw materials can be exemplified. Furthermore, examples of the compound having both a hydroxyl group and a carboxylic acid group include glycolic acid, hydroxypivalic acid, 3-hydroxy-2-methylpropionic acid, lactic acid, glyceric acid, malic acid, and citric acid.

  In addition to the above, the branching point of the hyperbranched polymer molecule that can be used in the present invention is a linear polyester oligomer obtained by a condensation reaction of a dibasic acid component and a glycol component, or a trifunctional or higher polyvalent carboxylic acid or polyvalent carboxylic acid. A branched polyester oligomer obtained by copolymerizing a divalent hydroxy compound may be used.

  As a constituent material of the linear or branched polyester oligomer that can be a branching point, various general dibasic acids and glycol compounds, or tri- or higher functional polycarboxylic acids and polyhydric alcohol compounds can be used. Dibasic acid compounds include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanoic acid and other aliphatic dibasic acids, terephthalic acid, isophthalic acid, orthophthalic acid, 1,2-naphthalenecarboxylic acid, 1,6 -An aromatic dibasic acid such as naphthalenedicarboxylic acid, or an alicyclic dibasic acid such as 1,2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid In view of heat resistance, terephthalic acid, isophthalic acid, orthophthalic acid, 1,2-naphthalene carboxylic acid, and 1,6-naphthalenedicarboxylic acid are preferable, and terephthalic acid and 1,2-naphthalene carboxylic acid are particularly preferable. 1,6-naphthalenedicarboxylic acid.

As glycol components, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol 2-methyl-1,3-propylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,4-diethyl-1, 5-pentanediol, 2-ethyl-1,3-hexanediol, 2,2-dimethyl-3-hydroxypropyl-2 ′, 2′-dimethyl-3-hydroxypropanoate, 2-n-butyl-2-ethyl -1,3-propanediol, 3-ethyl-1,5-pentanediol, 3-propyl-1,5-penta Aliphatic diols such as diol, 2,2-diethyl-1,3-propanediol, 3-octyl-1,5-pentanediol, 1,3-bis (hydroxymethyl) cyclohexane, 1,4-bis ( Hydroxymethyl) cyclohexane, 1,4-bis (hydroxyethyl) cyclohexane, 1,4-bis (hydroxypropyl) cyclohexane, 1,4-bis (hydroxymethoxy) cyclohexane, 1,4-bis (hydroxyethoxy) cyclohexane, 2 , 2-bis (4-hydroxymethoxycyclohexyl) propane, 2,2-bis (4-hydroxyethoxycyclohexyl) propane, bis (4-hydroxycyclohexyl) methane, 2,2-bis (4-hydroxycyclohexyl) propane, 3, (4), 8 (9) -Tricyclo [5 .2.1.0 ^2,6 ] alicyclic glycols such as decanedimethanol, or aromatic glycols such as ethylene oxide and / or propylene oxide adducts of bisphenol A, among these, 2,2-dimethyl-3-hydroxypropyl-2 ′, 2′-dimethyl-3-hydroxypropanate, 2,2-bis (4-hydroxycyclohexyl) propane, 3 (4), 8 (9) -tricyclo [ 5.2.1.0 ^2,6 ] decandimethanol and ethylene oxide and / or propylene oxide adducts of bisphenol A are preferred from the heat resistance characteristics of the resulting polyester resin and versatility as a raw material.

  Further, examples of the trifunctional or higher polyhydric carboxylic acid and polyhydric alcohol compound include trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, glycerin, trimethylolpropane, pentaerythritol and the like.

  In the above reaction, the condensation water produced by the condensation reaction is azeotropically dehydrated with toluene or xylene, the inert gas is blown into the reaction system, and the water or monoalcohol produced by the condensation reaction is blown out of the reaction system together with the inert gas. It proceeds by a method or a method of distilling under reduced pressure. As a catalyst used for the reaction, it is possible to use various metal compounds such as titanium-based, tin-based, antimony-based, zinc-based, germanium-based, and strong acid compounds such as p-toluenesulfonic acid and sulfuric acid as in the case of a normal polyester resin polymerization catalyst. I can do it.

  The resin having a hydroxyl value of 100 to 1000 mgKOH / g used in the present invention preferably has a number average molecular weight of 1000 to 60000, and the glass transition temperature is preferably 30 ° C. or higher and 100 ° C. or lower.

  In the resin having a hydroxyl value of 100 to 1000 mgKOH / g used in the present invention, if the hydroxyl value is less than 100 mgKOH / g, the effect of improving the curability may not be sufficiently exhibited. Even if a resin exceeding 1000 mg KOH / g is used, the effect is saturated and the cost for producing the resin increases, which is not realistic.

  The resin having a hydroxyl value of 100 to 1000 mgKOH / g used in the present invention is desirably 40 parts by weight or less with respect to 100 parts by weight of the polyester resin. The amount is preferably 30 parts by weight or less. If it exceeds 40 parts by weight, the properties of the polyester resin, particularly the adhesiveness, may not be sufficiently exhibited. The lower limit is preferably 0.1 parts by weight or more in order to exert the curability effect.

  The resin composition and adhesive of the present invention contain the above-described polyester resin, curing agent, and resin having a hydroxyl value of 100 to 1000 mgKOH / g as essential components. In particular, by blending a resin having a very high hydroxyl value of 100 to 1000 mg KOH / g, the hydroxyl group and the terminal hydroxyl group of the polyester resin effectively react with the curing agent to obtain a crosslinked product having excellent characteristics. In addition, the reaction rate can be dramatically increased.

  In addition to the essential polyester resin, the resin composition and adhesive of the present invention may contain other resins as necessary. Examples thereof include polyether polyols such as polyester polyol, polyethylene glycol, polypropylene glycol, polytrimethylene glycol, and polytetramethylene glycol, polycaprolactone, polycarbonate, polyurethane, acrylic resin, and vinyl resin.

  The resin composition and adhesive of the present invention may be blended with an inorganic filler such as silica or talc, or a pigment, or a rosin or acrylic tackifier depending on the application.

  The resin composition and adhesive of the present invention are preferably used by dissolving a polyester resin, a curing agent, and a resin having a hydroxyl value of 100 to 1000 mgKOH / g in a solvent. .

  Hereinafter, the present invention will be described specifically by way of examples. In the examples, “parts” means “parts by weight”. An evaluation method will be described.

Method for measuring gel fraction 1. The polyester resin composition solution was applied to a 50 μm thick biaxially stretched PET film so that the film thickness after drying was 20 μm, dried in a 120 ° C. hot air dryer for 1 hour, and then aged at 40 ° C. for 24 hours. The entire laminate obtained in this manner is cut into a size of 2.5 × 10 cm.
Measure the total weight of the sample cut in 2.1. (Weight A)
3. The sample is immersed in 50 ml of a solution of methyl ethyl ketone: toluene = 1: 1 (weight ratio) at 25 ° C. for 1 hour.
4). The sample is removed from the solution and dried in a hot air dryer at 100 ° C. for 1 hour.
5. The sample taken out from the hot air dryer is cooled to 25 ° C., and the weight is measured. (Weight B)
6). Again, while immersing the sample in a solution of methyl ethyl ketone (hereinafter abbreviated as MEK): toluene = 1: 1 (weight ratio), the cured product is scraped off from the PET film using a spatula to make only the PET film.
7). The PET film is dried and its weight is measured. (Weight C)
8). Calculate the gel fraction according to the following formula: The larger the number, the more cross-linked products are generated.

Method for measuring hydroxyl value About 0.5 g of sample is accurately weighed and placed in a 250 ml Erlenmeyer flask.
2. 20 ml of a mixed solution prepared by previously mixing 1 part by weight of acetic anhydride and 10 parts by weight of pyridine is weighed with a whole pipette and put into an Erlenmeyer flask.
3. Reflux for 20 minutes with a magnetic stirrer with a condenser and then cool to room temperature.
4). Add 20 ml of acetone through the cooler and remove them while washing the cooler and joint with 20 ml of water.
5. Phenolphthalein is added as an indicator and titrated with a 1 mol / L sodium hydroxide aqueous solution.
The hydroxyl value is calculated by subtracting the result of the blank (which does not contain the sample) separately measured from the result of 6.5.

Glass transition temperature measurement method About 5 mg of sample is put in an aluminum sample pan and sealed, and the temperature is increased to 200 ° C. using a differential scanning calorimeter (DSC) DSC-220 manufactured by Seiko Instruments Inc. The glass transition temperature (Tg) was defined as the temperature at the intersection of the base line extension below the glass transition temperature and the tangent indicating the maximum slope at the transition.

Adhesive Evaluation Method An adhesive was applied to a PET film having a thickness of 50 μm so that the film thickness after drying was 20 μm, and evaluated using a film dried for 1 hour with a 120 ° C. hot air dryer. Two laminated films are overlapped with another PET film with the adhesive layer inside, and using a roll laminator, pressure bonded at a temperature of 120 ° C., a load between rolls of 4 kgf / cm, and a line speed of 1 m / min. After obtaining an adhesive sample having an adhesive / PET layer structure, the sample was further aged at 40 ° C. for 24 hours to obtain an adhesive evaluation sample. A sample having a width of 15 mm was prepared, and a 180 ° peel test was performed at a pulling rate of 50 mm / min in an atmosphere of 25 ° C. using the sample.
○: 1.5 kgf / 15 mm or more ×; less than 1.5 kgf / 15 mm

Example 1
Polyester resin Byron 516 (Tg = −17 ° C.) manufactured by Toyobo Co., Ltd. was dissolved in methyl ethyl ketone (hereinafter abbreviated as MEK) at 50 ° C. to a solid content concentration of 50%, and then BOLTORN H20 (manufactured by PERSTORP) 1 part of a hydroxyl value of 480 mg KOH / g) was added to 100 parts of solid polyester resin and dissolved until uniform. After cooling to room temperature, 3 parts of Coronate L manufactured by Nippon Polyurethane Co., Ltd. was added as an isocyanate curing agent to 100 parts of the polyester resin, and stirred well.
The gel fraction of the obtained sample was 4%.

Examples 2 and 3
Samples were prepared in the same manner as in Example 1 except that the amount of curing agent was changed as shown in Table 1, and the gel fraction was measured.

Examples 4-6
A sample was prepared in the same manner as in Example 1 except that a polyester resin Byron 200 (Tg = 67 ° C.) manufactured by Toyobo Co., Ltd. was used, and the gel composition was measured.

Examples 7-9
A sample was prepared in the same manner as in Example 1 except that polyester resin Byron 300 (Tg = 7 ° C.) manufactured by Toyobo Co., Ltd. was used, and the gel composition was measured.

Examples 10-12
A sample was prepared in the same manner as in Example 1 except that the composition shown in Table 1 was used, and the gel fraction was measured.

Examples 13-39
A sample was prepared in the same manner as in Example 1 except that the composition shown in Table 1 was used, and the gel fraction was measured. However, the hydroxyl value of BOLTORN H20 (manufactured by PERSTORP), which is a high hydroxyl value resin used, is 480 mgKOH / g, the hydroxyl value of BOLTORN H40 (manufactured by PERSTORP) is 463 mgKOH / g, and the hydroxyl group of polyglycerin 10 (manufactured by Daicel Chemical Industries). The value is 531 mg KOH / g.

Comparative Example 1
Polyester resin Byron 200 manufactured by Toyobo Co., Ltd. was dissolved in MEK at 50 ° C. so as to have a solid content concentration of 50%, then cooled to room temperature, and Coronate L manufactured by Nippon Polyurethane Co., Ltd. was used as polyester resin 100 as an isocyanate curing agent. 2 parts were added to the part and stirred well.
This varnish was applied to a PET film having a thickness of 50 μm so that the film thickness after drying was 20 μm, dried with a hot air dryer at 120 ° C. for 1 hour, and then aged at 40 ° C. for 24 hours.
The gel fraction of the obtained sample was 0%.

Comparative Examples 2-11
A sample was prepared in the same manner as in Comparative Example 1 except that the composition shown in Table 1 was used, and the gel fraction was measured.

  In order to examine the effect of the blending amount of the high hydroxyl value resin, samples of Examples 35 to 38, Example 20, Comparative Example 6 and Comparative Example 11 were prepared in the same composition and evaluated for adhesiveness. The results are shown in Table 2.

The composition using the polyester resin of the present invention has a high degree of crosslinking, that is, a high gel fraction regardless of the molecular weight of the polyester, so that it can be applied not only to adhesives but also to a wide range of paints and coating agents in general. And has the excellent advantage of being applicable.

Claims (7)

  A resin composition comprising, as essential components, 0.5 to 50 parts by weight of a curing agent and 0.1 to 40 parts by weight of a resin having a hydroxyl value of 100 to 1000 mgKOH / g with respect to 100 parts by weight of a polyester resin.   The resin composition according to claim 1, wherein the curing agent is a polyfunctional isocyanate compound.   The resin composition according to claim 1 or 2, wherein the resin having a hydroxyl value of 100 to 1000 mgKOH / g is a hyperbranched polymer.   The resin composition according to claim 1 or 2, wherein the resin having a hydroxyl value of 100 to 1000 mgKOH / g is polyglycerin.   The adhesive agent containing the resin composition of Claims 1-4.   The coating material containing the resin composition of Claims 1-4. The coating agent containing the resin composition of Claims 1-4.