Polyester resin and adhesive composition, adhesive sheet, and laminate containing same

Abstract

The purpose of the present invention is to provide a polyester resin capable of achieving a high crosslink density while having a high reduced viscosity or a high Mw.　The polyester resin is characterized by containing 0.5-10.0 mol% of a polycarboxylic acid component having a valence of three or more with respect to 100 mol% of all of the polycarboxylic acid components, and in that the acid value (AV) of the polyester resin is 100 eq / t or more, and (i) and / or (ii) is satisfied.　(i) The reduced viscosity of the polyester resin is 0.50 dl / g or more. (ii) The weight average molecular weight (Mw) of the polyester resin is 79,000 or more.

Description

Polyester resin, and adhesive compositions, adhesive sheets, and laminates containing the same.

[0001] The present invention relates to polyester resins, and more particularly to polyester resins suitable for adhesive compositions for printed circuit boards used for bonding to substrates. The present invention also relates to polyester resins, adhesive compositions containing them, adhesive sheets and laminates, and further to printed circuit boards, laminated films for decorating three-dimensional molded products, films for laminating metal cans and packaging materials that include these as components. The present invention also relates to a method for manufacturing polyester resins.

[0002] In recent years, electronic devices have become smaller, lighter, more densely packed, and more powerful, leading to a growing demand for printed circuit boards (electronic circuit boards). Since printed circuit boards require heat resistance to withstand soldering during component mounting, adhesive compositions for printed circuit boards that can form a high crosslink density during curing are preferred.

[0003] To achieve a high crosslinking density during curing, the polyester resin used in the adhesive composition is first required to have a high acid value. As disclosed in Patent Document 1, in order to increase the acid value of the polyester resin, a prepolymer is generally obtained by esterifying a polycarboxylic acid component with a polyhydric alcohol component, and then modification with an acid anhydride is performed.

[0004] Japanese Patent Publication No. 2024-7384

[0005] Since adhesive compositions for printed circuit boards often contain fillers, it is important to increase the molecular weight of the polyester resin used and thereby increase its reduced viscosity. Increasing the molecular weight of the polyester resin also allows the resin to exhibit its inherent toughness, enabling it to withstand thermal expansion during soldering and suppressing blistering. However, in the method described in Patent Document 1, when attempting to increase the molecular weight of the polyester resin and thus its reduced viscosity, the number of hydroxyl groups in the polyester resin decreases relatively, reducing the number of reaction sites with acid anhydrides and limiting the number of carboxyl groups that can be introduced. Thus, until now, no polyester resin has been provided that can satisfy solder heat resistance requirements while possessing high reduced viscosity or high molecular weight (especially weight-average molecular weight Mw) and forming a high crosslink density.

[0006] This invention was made against the backdrop of the aforementioned problems. In other words, the object of this invention is to provide a polyester resin that has high reducing viscosity or high Mw while being capable of forming a high crosslink density.

[0007] As a result of diligent research, the inventors of the present invention have found that the above-mentioned problems can be solved by the means described below, and have arrived at the present invention. That is, the present invention consists of the following configuration.

[0008] [1] A polyester resin characterized by containing 0.5 to 10.0 mol% of trivalent or higher polycarboxylic acid components in 100 mol% of the total polycarboxylic acid components, having an acid value (AV) of 100 eq / t or more, and satisfying the following (i) and / or (ii): (i) The reduced viscosity of the polyester resin is 0.50 dl / g or more (ii) The weight-average molecular weight (Mw) of the polyester resin is 79,000 or more [2] The acid value (AV) of the carboxyl group belonging to the dicarboxylic acid component constituting the main chain of the polyester ｄ[1] The polyester resin according to [1], wherein the ratio of tricarboxylic acid components in which three carboxyl groups form an ester bond is 60% or more among the polycarboxylic acid components of trivalent or higher. [4] The polyester resin according to any one of [1] to [3], wherein the amount of unreacted monomers of the tricarboxylic acid component is 500 ppm or less. [5] The polyester resin according to any one of [1] to [4], wherein the antimony content in the polyester resin is 150 ppm or less. [6] The polyester resin according to any one of [1] to [5], wherein the polycarboxylic acid component of trivalent or higher is a tricarboxylic acid component. [7] The polyester resin according to any one of [1] to [6], comprising one or more dicarboxylic acid components selected from the group consisting of aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and aromatic dicarboxylic acids as the dicarboxylic acid components constituting the polyester resin. [8] A polyester resin according to any one of [1] to [7], wherein the hydroxyl value (OHV) is 70 to 400 eq / t. [9] A polyester resin according to any one of [1] to [8], wherein the glass transition temperature (Tg) is 0 to 80°C.

[10] A polyester resin according to any one of [1] to [9], wherein the polycarboxylic acid component with tetravalent or higher is 6 mol% or less in 100 mol% of the polycarboxylic acid component.

[11] An adhesive composition comprising the polyester resin according to any one of [1] to

[10] .

[12] The adhesive composition according to

[11] for use in printed circuit boards.

[13] An adhesive sheet in which the adhesive composition according to

[11] is laminated on a release substrate.

[14] A laminate in which the adhesive composition according to

[11] is laminated on a substrate which is a resin substrate, a metal substrate, paper, or an inorganic nonmetal substrate.

[15] A printed circuit board comprising the laminate according to

[14] as a component.

[16] A laminated film for decorating three-dimensional molded articles, comprising a layer formed from the adhesive composition described in

[11] as a component.

[17] A film for laminating metal cans, comprising a layer formed from the adhesive composition described in

[11] as a component.

[18] A packaging material, comprising a layer formed from the adhesive composition described in

[11] as a component.

[19] A method for producing a polyester resin having an acid value (AV) of 100 eq / t or more, comprising: 1) a step of esterifying a polycarboxylic acid component and a polyhydric alcohol component; 2) a step of polycondensing the reactant obtained in step 1), wherein no acid addition step or depolymerization step is performed after step 2).

[20] The method according to

[19] , wherein the acid value (AV) of the polyester resin is 200 eq / t or more.

[21] The method according to

[19] or

[20] , wherein the reduced viscosity of the polyester resin is 0.52 dl / g or more.

[0009]

[22] Use of an adhesive composition containing a polyester resin according to any one of [1] to

[10] for use in printed circuit boards.

[0010] According to the present invention, a polyester resin can be obtained that has high reducing viscosity or high Mw while also being capable of forming a high crosslink density.

[0011] <Polyester Resin> The polyester resin of the present invention contains 0.5 to 10.0 mol% of trivalent or higher polycarboxylic acid components out of 100 mol% of the total polycarboxylic acid components, has an acid value (AV) of 100 eq / t or more, and is characterized by satisfying the following (i) and / or (ii): (i) The reduced viscosity of the polyester resin is 0.50 dl / g or more (ii) The weight-average molecular weight (Mw) of the polyester resin is 79,000 or more Thus, the polyester resin of the present invention contains a predetermined amount of trivalent or higher polycarboxylic acid components, and is characterized by having both a high reduced viscosity or high Mw and a high acid value. Because the polyester resin has a high reduced viscosity or high Mw and a high acid value, adhesive compositions containing the polyester resin can form a high crosslink density and have good solder heat resistance.

[0012] The polyester resin of the present invention satisfies (i) and / or (ii) above, specifically satisfying either (i) or (ii), or both (i) and (ii), and preferably satisfying either (i) or (ii).

[0013] When the polyester resin of the present invention satisfies (i), the reduced viscosity (ηsp / c) of the polyester resin of the present invention is 0.50 dl / g or more, preferably 0.50 to 1.4 dl / g, more preferably 0.52 to 1.4 dl / g, more preferably 0.55 to 1.2 dl / g, and even more preferably 0.60 to 1.0 dl / g. Within the above range, the inherent toughness of the polyester resin is exhibited, it can withstand thermal expansion during soldering, and blistering is suppressed.

[0014] When the polyester resin of the present invention satisfies (i), the weight-average molecular weight (Mw) of the polyester resin of the present invention is preferably 20,000 to 500,000, more preferably 60,000 to 400,000, even more preferably 80,000 to 300,000, even more preferably 90,000 to 200,000, and particularly preferably 105,000 to 150,000. Within the above range, an adhesive composition can be obtained that is easy to handle when dissolved in a solvent and has excellent adhesive properties.

[0015] When the polyester resin of the present invention satisfies (i), the degree of dispersion (Mw / Mn) of the polyester resin of the present invention is preferably 5.0 to 50.0, more preferably 7.0 to 45.0, even more preferably 8.0 to 40.0, and even more preferably 10.0 to 35.0. Within the above range, an adhesive composition with excellent stability can be obtained.

[0016] When the polyester resin of the present invention satisfies (ii), the weight-average molecular weight (Mw) of the polyester resin of the present invention is 79,000 or more, preferably 79,000 to 500,000, more preferably 80,000 to 500,000, more preferably 90,000 to 450,000, even more preferably 105,000 to 400,000, even more preferably 200,000 to 350,000, and particularly preferably 250,000 to 300,000. Within the above range, an adhesive composition can be obtained that is easy to handle when dissolved in a solvent and has excellent adhesive properties.

[0017] When the polyester resin of the present invention satisfies (ii), the reduced viscosity (ηsp / c) of the polyester resin of the present invention is, for example, 0.50 dl / g or more, preferably 0.50 to 1.4 dl / g, more preferably 0.52 to 1.4 dl / g, more preferably 0.55 to 1.2 dl / g, and even more preferably 0.60 to 1.0 dl / g. Within the above range, the inherent toughness of the polyester resin is exhibited, it can withstand thermal expansion during soldering, and blistering is suppressed.

[0018] When the polyester resin of the present invention satisfies (ii), the degree of dispersion (Mw / Mn) of the polyester resin of the present invention is preferably 5.0 to 50.0, more preferably 10.0 to 45.0, even more preferably 15.0 to 40.0, and even more preferably 20.0 to 35.0. Within the above range, an adhesive composition with excellent stability can be obtained.

[0019] The polyester resin of the present invention has a chemical structure obtained by a polycondensate of a polycarboxylic acid component and a polyhydric alcohol component, preferably having a chemical structure obtained by a polycondensate of a dicarboxylic acid component and a trivalent or higher polycarboxylic acid component (including tricarboxylic acid components and tetravalent or higher polycarboxylic acid components) and a diol component. In this disclosure, the polycarboxylic acid component includes a dicarboxylic acid component, a trivalent polycarboxylic acid component (tricarboxylic acid), and a tetravalent or higher polycarboxylic acid component, and the polyhydric alcohol component includes a diol component and a trivalent or higher polyhydric alcohol component. Furthermore, the various polycarboxylic acids exemplified below include not only the polycarboxylic acid itself, but also esters of the polycarboxylic acid and polycarboxylic acid anhydrides.

[0020] The dicarboxylic acid component and the diol component each consist of one or more selected components. The dicarboxylic acid component constituting the polyester resin is not particularly limited, but the dicarboxylic acids or their esters and dicarboxylic acid anhydrides listed below can be used. Specifically, examples of dicarboxylic acids include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and aromatic dicarboxylic acids. Examples of aliphatic dicarboxylic acids include adipic acid, sebacic acid, dimer acid, fumaric acid, maleic acid, succinic acid, etc. Examples of alicyclic dicarboxylic acids include 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic acid, hexahydrophthalic acid, methyltetrahydrophthalic acid, etc. Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, 2,5-frandicarboxylic acid, 5-sodium sulfodimethylisophthalic acid and their esters and acid anhydrides can be used. From the viewpoint of improving the dielectric properties and solder heat resistance of the adhesive composition, aliphatic dicarboxylic acids and aromatic dicarboxylic acids are preferred as the dicarboxylic acid component, and it is more preferable to include at least an aromatic dicarboxylic acid. Preferred aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, and 2,5-franzicarboxylic acid, more preferably terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and even more preferably terephthalic acid and isophthalic acid. When an aromatic dicarboxylic acid is included, the aromatic dicarboxylic acid component is preferably 20 to 100 mol%, more preferably 40 to 90 mol%, and even more preferably 60 to 80 mol% of the 100 mol% of the dicarboxylic acid component constituting the polyester resin. Furthermore, when terephthalic acid and isophthalic acid are included as aromatic dicarboxylic acids, their content ratio (terephthalic acid:isophthalic acid) is preferably 5:95 to 95:5, more preferably 10:90 to 60:40, and even more preferably 20:80 to 40:60 on a molar basis. By keeping terephthalic acid within the aforementioned range, a polyester resin with excellent solubility is obtained. Furthermore, by keeping isophthalic acid within the aforementioned range, it becomes possible to obtain polyester resin at a low cost.

[0021] From the viewpoint of the hygroscopic properties of polyester resin, it is preferable to have a low content of aromatic dicarboxylic acids having sulfonic acid groups (e.g., sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5(4-sulfophenoxy)isophthalic acid, etc.). The content of aromatic dicarboxylic acids having sulfonic acid groups in 100 mol% of polycarboxylic acid components is preferably 10 mol% or less, more preferably 5 mol% or less, even more preferably 3 mol% or less, even more preferably 1 mol% or less, and particularly preferably 0 mol%.

[0022] The diol components constituting the polyester resin are not particularly limited, but examples include aliphatic diols, alicyclic diols, aromatic diols, and bisphenol skeleton-containing monomers. Examples of aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,3-hexanediol, and 2-methyl-1,3-hexanediol. Tyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-n-propyl-1,3-propanediol, 2,2-di-n-propyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2,2-di-n-butyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, dimergio Aliphatic diols such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polytetramethylene glycol, and polypropylene glycol can be used. Alicyclic diols such as 1,4-cyclohexanedimethanol and tricyclodecanedimethanol can be used. Aromatic diols such as diphenolic acids can be used. Bisphenol skeleton-containing monomers such as bisphenol A, bisphenol B, bisphenol E, bisphenol F, bisphenol AP, bisphenol BP, bisphenol P, bisphenol PH, bisphenol S, bisphenol Z, 4,4'-dihydroxybenzophenone, bisphenol fluorene and their hydrogenated products, and glycols such as ethylene oxide adducts and propylene oxide adducts obtained by adding 1 to several moles of ethylene oxide or propylene oxide to the hydroxyl group of bisphenols can be used. Aliphatic diols are preferred as diols. ２－６ Aliphatic diols are preferred.

[0023] From the viewpoints of heat resistance, low moisture absorption, and long-term durability in a humid heat environment, the content of glycols containing ether bonds other than bisphenol skeleton-containing monomers such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol is preferably low. The content of this component is preferably 20 mol% or less, more preferably 10 mol% or less, still more preferably 5 mol% or less, even more preferably 1 mol% or less, and particularly preferably 0 mol% in 100 mol% of diol.

[0024] As the diol component constituting the polyester resin, diols having an alkylene group with 4 or more carbon atoms are particularly preferred, and examples include 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,3-hexanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, dimer diol, polytetramethylene glycol, etc. Among them, 1,6-hexanediol is preferred. By using a diol having an alkylene group with 4 or more carbon atoms, the glass transition temperature (Tg) of the polyester resin tends to decrease. In 100 mol% of the total polyhydric alcohol component, the diol component having an alkylene group with 4 or more carbon atoms is preferably 1 to 85 mol%, more preferably 10 to 80 mol%, and still more preferably 30 to 75 mol%.

[0025] The diol component constituting the polyester resin may include a diol having an alkylene group with three or fewer carbon atoms, and examples include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-methyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-n-propyl-1,3-propanediol, 2,2-di-n-propyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, and 2,2-di-n-butyl-1,3-propanediol. Among these, ethylene glycol, 2-methyl-1,3-propanediol, and neopentyl glycol are preferred, and 2-methyl-1,3-propanediol is even more preferred. Using a diol having an alkylene group with 3 or fewer carbon atoms tends to increase the glass transition temperature (Tg) of the polyester resin. Preferably, the diol component having an alkylene group with 3 or fewer carbon atoms is 1 to 100 mol%, more preferably 20 to 80 mol%, and even more preferably 40 to 60 mol% of the total polyhydric alcohol component.

[0026] The polyester resin of the present invention can also be copolymerized with lactones or lactams. For example, ε-caprolactone or ε-caprolactam can be used.

[0027] In the polycarboxylic acid component and polyhydric alcohol component that constitute the polyester resin of the present invention, raw materials derived from biomass resources can be used. Biomass resources include those in which solar energy is converted and stored in the form of starch, cellulose, etc. through the photosynthesis of plants, the bodies of animals that grow by eating plants, and products made by processing plant or animal bodies. Among them, more preferable biomass resources are plant resources. For example, wood, rice straw, rice husks, rice bran, old rice, corn, sugarcane, cassava, sago palm, okara, corn cob, tapioca cactus, bagasse, vegetable oil cake, taro, buckwheat, soybeans, oils and fats, waste paper, paper-making residues, fishery residues, livestock excrement, sewage sludge, food waste, etc. are mentioned. More preferably, they are corn, sugarcane, cassava, and sago palm. Specific examples of polycarboxylic acid raw materials derived from biomass resources include, for example, adipic acid, sebacic acid, fumaric acid, itaconic acid, terephthalic acid, and 2,5-furandicarboxylic acid, etc. Specific examples of polyhydric alcohol raw materials derived from biomass resources include, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,4-butanediol, and 1,4-cyclohexanedimethanol, etc.

[0028] The polyester resin of the present invention may contain a urethane bond (—OCO—NH—), a urea bond (—NH—CO—NH—), an ether bond (—O—) such as an alkyl ether bond or a phenyl ether bond, and a carbonate bond (—OCO—O—), but from the viewpoints of low moisture absorption and long-term durability in a moist heat environment, it is desirable that the content of these bonds is as low as possible. The concentrations of the urethane bond, urea bond, ether bond, and carbonate bond in the polyester resin of the present invention are each preferably 5 mmol / g or less, more preferably 3 mmol / g or less, still more preferably 2 mmol / g or less, further preferably 1 mmol / g or less, even more preferably 0.5 mmol / g or less, and particularly preferably 0.2 mmol / g or less. These concentrations can be measured by known methods using NMR or the like.

[0029] The polyester resin of the present invention is copolymerized with a polycarboxylic acid component of trivalent or higher, and it is particularly preferable that a tricarboxylic acid component is copolymerized. These components allow for the introduction of a branched structure into the main chain of the polyester resin, contributing to the high molecular weight of the polyester resin. Of the total 100 mol% of polycarboxylic acid components, the polycarboxylic acid component of trivalent or higher is contained in an amount of 0.5 to 10.0 mol%, preferably 1.0 to 8.0 mol%, more preferably 1.2 to 6.0 mol%, and even more preferably 1.5 to 4.0 mol%. If the amount falls below the lower limit, it becomes difficult to obtain a polyester resin with a high acid value (AV, AVd) and high molecular weight. If the amount exceeds the upper limit, gelation may occur during manufacturing. Within the above range, a polyester resin with a high molecular weight can be obtained even if the content of the polycarboxylic acid component of trivalent or higher is small.

[0030] Examples of tricarboxylic acid components include trivalent aromatic carboxylic acids such as trimellitic acid, trimesic acid, and trimellitic anhydride (TMA); trivalent aliphatic carboxylic acids such as citric acid and citric anhydride; and trivalent alicyclic tricarboxylic acids such as 1,2,4-cyclohexanetricarboxylic acid, 1,3,5-cyclohexanetricarboxylic acid, and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride. Among these, trivalent aromatic carboxylic acids are preferred, and trimellitic acid or trimellitic anhydride is more preferred. By copolymerizing the tricarboxylic acid component, it becomes easier to introduce the following tricarboxylic acid components into the main chain of the polyester resin: (1) a tricarboxylic acid component in which three carboxyl groups form ester bonds (with the polyester main chain) (hereinafter sometimes referred to as "triester"), (2) a tricarboxylic acid component in which two carboxyl groups form ester bonds (with the polyester main chain) and one carboxyl group remains in a free state (hereinafter sometimes referred to as "diester"), and (3) a tricarboxylic acid component in which one carboxyl group forms ester bonds (with the polyester main chain) and two carboxyl groups remain in a free state (hereinafter sometimes referred to as "monoester"). The triester can give the polyester a branched structure, thus contributing to the high molecular weight of the polyester resin. In the diester and monoester, the one or two carboxyl groups remaining in a free state contribute to the formation of high-density crosslinks.

[0031] The polyester resin of the present invention contains, for example, 0.5 to 10.0 mol%, preferably 1.0 to 8.0 mol%, more preferably 1.2 to 6.0 mol%, and even more preferably 1.5 to 4.0 mol% of the tricarboxylic acid component in 100 mol% of the total polycarboxylic acid component. If the amount falls below the lower limit, it becomes difficult to increase the acid value of the polyester resin. If the amount exceeds the upper limit, the amount of triester increases, leading to excessive thickening during polyester resin production, making it prone to gelation and difficult to control the molecular weight. Furthermore, it is undesirable because the tricarboxylic acid component tends to remain unreacted.

[0032] Examples of polycarboxylic acid components with four or more valencies include aromatic carboxylic acids such as pyromellitic acid, benzophenonetetracarboxylic acid, pyromellitic anhydride (PMDA), and ethylene glycol bistrimellitate dianhydride, as well as aliphatic carboxylic acids such as 1,2,3,4-butanetetracarboxylic acid. These can be used individually or in combination of two or more. The polycarboxylic acid component with four or more valencies is preferably 0 to 6 mol%, more preferably 0 to 3 mol%, even more preferably 0 to 1 mol%, and particularly preferably 0 to 0.5 mol% of 100 mol% of the polycarboxylic acid component of the polyester resin of the present invention. By keeping the value below the upper limit, the generation of microgels and gelation of the resin can be prevented. Furthermore, it prevents thickening during the production of the polyester resin and makes it easier to control the molecular weight, enabling stable mass production.

[0033] The content of the triester compound in the polyester resin of the present invention is preferably 0.5 to 10.0 mol%, more preferably 1.0 to 8.0 mol%, even more preferably 1.2 to 6.0 mol%, even more preferably 1.5 to 5.5 mol%, and particularly preferably 1.8 to 5.0 mol%, relative to the total amount of polycarboxylic acid constituting the polyester resin. Setting the content above the lower limit makes it easier to obtain a polyester resin that can form a high crosslink density when used in an adhesive composition. Setting the content below the upper limit makes it easier to suppress gelation during the production of the polyester resin. The content of the triester compound is １ It can be measured by H-NMR and TOCSY spectroscopy, for example, １ When using H-NMR and TOCSY spectral measurements, first １ The integral value of the peak derived from the tricarboxylic acid component is calculated by 1H-NMR measurement. Next, by TOCSY spectral measurement, the integral values ​​of the peaks that form triesters and the other peaks of the tricarboxylic acid component are calculated separately, thereby revealing the content of the triester-forming component among the tricarboxylic acid components.

[0034] The proportion of triester compounds in the trivalent or higher polycarboxylic acid components of the polyester resin of the present invention is preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, and even more preferably 90% or more. The upper limit is not particularly limited, but may be 100% or less, or 96% or less (i.e., preferably 60-100%, more preferably 70-100%, even more preferably 80-96%, and even more preferably 90-96%). Within this range, a branched structure can be sufficiently formed in the polyester resin, the acid value (AVd) is high, and furthermore, the amount of unreacted trivalent or higher polycarboxylic acid components is reduced because the trivalent or higher polycarboxylic acid components have reacted sufficiently, resulting in a polyester resin with excellent thermal stability and solder heat resistance. In addition, within this range, a large portion of the trivalent or higher polycarboxylic acids are introduced into the main chain of the polyester resin. This reduces the amount of trivalent or higher polycarboxylic acids present at the polyester resin ends or as unreacted products, suppressing the thickening reaction during storage, resulting in a polyester resin with excellent storage stability and solder heat resistance. For similar reasons, the mono- or diester ratio of the polyester resin of the present invention is preferably 40% or less, more preferably 30% or less, even more preferably 20% or less, and even more preferably 10% or less. The lower limit is not particularly limited but may be 0% or more, or 4% or more (i.e., preferably 0 to 40%, more preferably 0 to 30%, even more preferably 4 to 20%, and even more preferably 4 to 10%). The triester ratio and the mono- or diester ratio can be determined by the method described in the examples.

[0035] In a preferred embodiment of the present invention, the polyester resin of the present invention contains 0.5 to 10.0 mol% of trivalent or higher polycarboxylic acid components in 100 mol% of the total polycarboxylic acid components, has a reduced viscosity of 0.50 dl / g or more, has an acid value (AV) of 100 eq / t or more, and satisfies the requirement that the ratio of tricarboxylic acid components in which three carboxyl groups form an ester bond among the trivalent or higher polycarboxylic acid components is 60% or more. For example, polyester resins with a low glass transition temperature (Tg) have the characteristic of high wettability to substrates and good adhesion, and polyester resins having a Tg below room temperature are preferably used in this field. However, there is a problem that the reduced viscosity of the polyester resin changes significantly when stored at a Tg above the Tg, and such low-Tg resins are usually stored under refrigeration. Therefore, from the viewpoint of controlling the reduced viscosity of the polyester resin, it is desirable that the change in reduced viscosity due to such storage be small, but the polyester resin of Comparative Example 2 in Patent Document 1 did not exhibit sufficient storage stability. In other words, until now, a polyester resin that possesses excellent storage stability, high reducing viscosity, and the ability to form a high crosslink density has not been provided. In a preferred embodiment, a polyester resin with a high triester ratio has a tendency for most of the trivalent or higher polycarboxylic acids used in the manufacturing process to be introduced into the main chain of the polyester resin, resulting in a small amount of trivalent or higher polycarboxylic acids present at the polyester resin ends (e.g., monoesters) or as unreacted products. This suppresses the thickening reaction, and even when stored at Tg or above, the change in reducing viscosity is small, resulting in excellent storage stability and the advantage of not requiring refrigeration equipment. In short, a polyester resin is provided that possesses excellent storage stability, high reducing viscosity, and the ability to form a high crosslink density.

[0036] Furthermore, the polyester resin of the present invention may be copolymerized with a trivalent or higher polyhydric alcohol component. Examples of trivalent or higher polyhydric alcohol components include glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, α-methylglucose, mannitol, and sorbitol, which can be used individually or in combination of two or more.

[0037] In the polyester resin of the present invention, the molecular chain ends of the polyester may be carboxyl groups derived from the dicarboxylic acid component that constitutes the main chain of the polyester. The polyester resin of the present invention is also characterized by having a large amount of carboxyl groups derived from the dicarboxylic acid component, and the acid value (AV) derived from this dicarboxylic acid component is also a feature. ｄ The acid value (AV) is, for example, 100 eq / t or more, preferably 100 to 500 eq / t, more preferably 120 to 500 eq / t, more preferably 150 to 450 eq / t, even more preferably 180 to 400 eq / t, and even more preferably 200 to 350 eq / t. By keeping it within this range, it is possible to reduce the amount of tricarboxylic acid used while maintaining a high acid value polyester resin, which leads to suppression of gelation during manufacturing. Furthermore, keeping it within this range also results in good thermal stability of the polyester resin. Acid value (AV) ｄ To adjust the value within the aforementioned range, it is desirable to carry out, for example, the reaction described later.

[0038] In a preferred embodiment of the present invention, the polyester resin of the present invention contains 0.5 to 10.0 mol% of trivalent or higher polycarboxylic acid components in 100 mol% of the total polycarboxylic acid components, the reduced viscosity of the polyester resin is 0.50 dl / g or more, the acid value (AV) of the polyester resin is 100 eq / t or more, and the acid value (AV) of the carboxyl group belonging to the dicarboxylic acid component constituting the main chain of the polyester is ｄ) satisfies 100 eq / t or more. The inventors' investigations revealed that even if a polyester resin with a high molecular weight could be synthesized, the reduced viscosity of the polyester resin changed significantly due to the heat in the synthesis apparatus between the time of synthesis and extraction. From the viewpoint of controlling the reduced viscosity of the polyester resin, it is desirable that such thermal changes be small, but the polyester resin described in Comparative Example 2 of Patent Document 1, although seemingly having a high acid value and high reduced viscosity, did not exhibit sufficient thermal stability. In other words, a polyester resin that is excellent in thermal stability, has high reduced viscosity, and can form a high crosslink density has not been provided until now. In a preferred embodiment of the polyester resin, the amount of carboxyl groups derived from the dicarboxylic acid component can be increased, so the amount of polycarboxylic acid component with a value of 3 or more can be reduced, which leads to the suppression of gelation during manufacturing. In addition, since the carboxyl groups belonging to the dicarboxylic acid component have lower reactivity with hydroxyl groups compared to carboxyl groups derived from tricarboxylic acid, the thermal stability of the polyester resin is also good. In short, a polyester resin is provided that is excellent in thermal stability, has high reduced viscosity, and can form a high crosslink density.

[0039] The acid value (AV) of the polyester resin of the present invention is 100 eq / t or higher, preferably 100 to 1000 eq / t, more preferably 120 to 1000 eq / t, more preferably 150 to 800 eq / t, even more preferably 180 to 500 eq / t, even more preferably 200 to 400 eq / t, and particularly preferably 220 to 350 eq / t. Setting it above the lower limit increases the number of reaction sites with the epoxy resin described later, allowing for the formation of a tough adhesive layer with high crosslinking density after curing, making it easier to obtain an adhesive composition with excellent solder heat resistance. Setting it below the upper limit further improves adhesion and low dielectric properties.

[0040] In the polyester resin of the present invention, some of the tricarboxylic acid component may remain unreacted. If there is a large amount of unreacted tricarboxylic acid component, it may lead to poor curing or deterioration of storage stability when used in an adhesive composition; therefore, it is preferable to have a small amount of unreacted tricarboxylic acid component. Specifically, the amount of unreacted tricarboxylic acid monomer in the polyester resin should be, for example, 500 ppm or less, preferably 300 ppm or less, more preferably 200 ppm or less, even more preferably 150 ppm or less, even more preferably 100 ppm or less, and particularly preferably 50 ppm or less. In practical terms, it may also be 1 ppm or more, 10 ppm or more, or 20 ppm or more (i.e., preferably 0 to 500 ppm, preferably 1 to 300 ppm, more preferably 1 to 200 ppm, even more preferably 10 to 150 ppm, even more preferably 10 to 100 ppm, and particularly preferably 20 to 50 ppm).

[0041] The hydroxyl value (OHV) of the polyester resin of the present invention is preferably 70 to 400 eq / t, more preferably 100 to 300 eq / t, and even more preferably 150 to 250 eq / t. By keeping it within this range, it becomes easier to form an adhesive composition with excellent dielectric properties when the polyester resin is used in an adhesive composition.

[0042] The number-average molecular weight (Mn) of the polyester resin of the present invention is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and even more preferably 9,000 to 30,000. Within this range, an adhesive composition can be obtained that is easy to handle when dissolved in a solvent and has excellent adhesive properties.

[0043] The glass transition temperature (Tg) of the polyester resin of the present invention is preferably 0 to 80°C, more preferably 5 to 50°C, and even more preferably 10 to 35°C. Within this range, an adhesive composition with excellent adhesion can be obtained.

[0044] The polyester resin of the present invention can be produced by any known method that can produce a polycondensate of a polycarboxylic acid component and a polyhydric alcohol component, but it is preferable that the method includes, for example, 1) a step of esterifying the polycarboxylic acid component and the polyhydric alcohol component, and 2) a step of polycondensing the reaction product obtained in step 1). Each step will be described in detail below.

[0045] In step 1), an oligomer is produced by esterifying a polycarboxylic acid component and a polyhydric alcohol component. The polycarboxylic acid component and polyhydric alcohol component may be those mentioned above as appropriate, and it is preferable that the polycarboxylic acid component includes a dicarboxylic acid component and a trivalent or higher polycarboxylic acid component. The amount of trivalent or higher polycarboxylic acid component used in step 1) is preferably 50 to 100 mol%, more preferably 70 to 100 mol%, even more preferably 90 to 100 mol%, and even more preferably 95 to 100 mol%, relative to 100 mol% of the total amount of trivalent or higher polycarboxylic acid components added up to the production of the polyester resin. By charging an amount within the above range in step 1), the reaction of these components can be promoted, and the amount of unreacted components (preferably unreacted tricarboxylic acid components) can be reduced. Furthermore, even if the amount of trivalent or higher polycarboxylic acid component itself is small, the polyester resin can be made high molecular weight, which leads to the suppression of gelation and reduces the amount of unreacted components.

[0046] The ratio G / A (polyhydric alcohol component / polyhydric carboxylic acid component) of the polyhydric carboxylic acid component to be charged in step 1) is preferably 0.95 to 1.08, more preferably 0.97 to 1.07, even more preferably 0.99 to 1.06, and even more preferably 1.00 to 1.05. By adjusting within the above range, not only oligomers having only hydroxyl groups at the ends but also oligomers having both hydroxyl groups and carboxyl groups (preferably carboxyl groups derived from the dicarboxylic acid component) at the ends can be produced. In the subsequent polycondensation reaction of step 2), the hydroxyl groups react with the polyhydric carboxylic acid of trivalent or higher, for example, forming triester compounds and introducing a branched structure into the polyester resin. This contributes to increasing the molecular weight of the polyester resin. On the other hand, many of the terminal carboxyl groups remain at the ends of the polyester resin even after step 2), contributing to increasing the acid value of the polyester resin. Furthermore, with this manufacturing method, even if the amount of trivalent or higher polycarboxylic acid component itself is small, the polyester resin can be made to have a high molecular weight, which helps to suppress gelation and reduces the amount of unreacted components.

[0047] In step 1), a polymerization catalyst can be used. Conventional known polymerization catalysts such as titanium compounds, antimony compounds, germanium compounds, and metal acetates can be used as polymerization catalysts. For example, as titanium compounds, tetra-n-butyl titanate, tetraisopropyl titanate, titanium oxyacetyl cetonate, etc. can be used; as antimony compounds, antimony trioxide, tributoxyantimony, etc. can be used; as germanium compounds, germanium oxide, tetra-n-butoxygermanium, etc. can be used; and as metal acetates, acetates of magnesium, iron, zinc, manganese, cobalt, aluminum, etc. can be used. These can be used individually or in combination of two or more. However, since the amount of antimony compound used as a polymerization catalyst increases the likelihood of generating foreign matter, it is desirable to use as little antimony as possible. The antimony content in the polyester resin is preferably 0 to 150 ppm, more preferably 0 to 100 ppm, even more preferably 0 to 50 ppm, even more preferably 0 to 1 ppm, and particularly preferably 0 ppm. It is also possible to include a small amount of zinc as a polymerization catalyst, but from the viewpoint of the thermal stability of the polyester resin, it is desirable to use as little zinc as possible. The zinc content in the polyester resin is preferably less than 40 ppm, more preferably 0 to 30 ppm, even more preferably 0 to 10 ppm, even more preferably 0 to 1 ppm, and particularly preferably 0 ppm. The amount of metal derived from the polymerization catalyst in the polyester resin can be determined by the method described in the examples.

[0048] As the polymerization catalyst, at least a titanium compound is preferably used. When the total amount of metal derived from the polymerization catalyst in the polyester resin is 100% by mass, the titanium content is preferably 10 to 100% by mass, more preferably 30 to 100% by mass, even more preferably 50 to 100% by mass, and particularly preferably 80 to 100% by mass, and may also be 90 to 100% by mass. By setting it above the lower limit, better heat resistance for humidified soldering can be obtained. Furthermore, the titanium content in the polyester resin is preferably 2 ppm or more, more preferably 5 ppm or more, even more preferably 10 ppm or more, and particularly preferably 15 ppm or more. By setting it above the lower limit, better heat resistance for humidified soldering can be obtained.

[0049] The esterification reaction in step 1) is preferably carried out under heating. The reaction temperature is preferably 180 to 280°C, more preferably 200 to 260°C. The reaction time is preferably 1 to 10 hours, more preferably 2 to 8 hours.

[0050] In step 2), the reactant (oligomer) obtained in step 1) is polycondensed to produce a polyester resin. The polycondensation reaction in step 2) is preferably carried out under heating, and the reaction temperature is preferably 180 to 280°C, more preferably 200 to 260°C. The reaction time is preferably 0.1 to 5 hours, more preferably 0.5 to 3 hours.

[0051] Step 2) may be carried out under vacuum or in an inert atmosphere (for example, in a nitrogen stream). Step 2) may be divided into, for example, initial polymerization and late polymerization. In initial polymerization, polymerization is preferably carried out at 100 mmHg or less (preferably 50 mmHg or less) at 180 to 280°C (preferably 200 to 260°C) for 0.1 to 2 hours (preferably 0.2 to 1 hour), and in late polymerization, polymerization is preferably carried out at 10 mmHg or less (preferably 5 mmHg or less) at 180 to 280°C (preferably 200 to 260°C) for 0.1 to 3 hours (preferably 0.5 to 2 hours).

[0052] After step 2), an acid addition step or a depolymerization step may be carried out, but it is desirable not to carry out an acid addition step or a depolymerization step after step 2) because there is a risk of the hydroxyl groups of the polyester resin decreasing or of unreacted products remaining. Normally, in order to obtain a polyester resin with a high acid value, such acid addition or depolymerization steps are carried out, but with the above method, a polyester resin having a high acid value (for example, an acid value (AV) of 100 eq / t or more) can be produced without carrying out an acid addition step or a depolymerization step. In other words, this disclosure also includes a method for producing a polyester resin with an acid value (AV) of 100 eq / t or more, comprising: 1) a step of esterifying a polycarboxylic acid component and a polyhydric alcohol component; and 2) a step of polycondensing the reactants obtained in step 1), characterized in that no acid addition step or depolymerization step is carried out after step 2).

[0053] <Adhesive Composition> The adhesive composition of the present invention contains the polyester resin described above. The polyester resin is preferably included as the main component in the adhesive composition. In this specification, the main component in the adhesive composition specifically refers to the component that is present in the highest amount in the solid content of the adhesive composition. The polyester resin content in the adhesive composition of the present invention is preferably 5 to 99.5% by mass, more preferably 20 to 99% by mass, even more preferably 30 to 98% by mass, even more preferably 40 to 97% by mass, and particularly preferably 50 to 96% by mass, based on 100% by mass of the solid content of the adhesive composition. Within the above range, good adhesion and heat resistance are obtained, which is preferable.

[0054] <Epoxy Resin> The adhesive composition of the present invention preferably contains an epoxy resin. The epoxy resin is not particularly limited as long as it has two or more glycidyl groups in its molecule. By using an epoxy resin, the carboxyl groups and glycidyl groups of the polyester resin react to form a crosslinked structure, which can improve the solder heat resistance and adhesive properties of the adhesive composition.

[0055] The epoxy resin is not particularly limited, but examples include biphenyl-type epoxy resins, naphthalene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, novolac-type epoxy resins, alicyclic epoxy resins, dicyclopentadiene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ether-type epoxy resins, epoxy-modified polybutadiene, and glycidyl group-containing isocyanuric acid. These can be used individually or in combination of two or more types. Among these, novolac-type epoxy resins and glycidylamine-type epoxy resins are preferred in terms of solder heat resistance and low dielectric properties.

[0056] Novolac-type epoxy resins specifically refer to polyfunctional epoxy resins obtained by reacting novolac resins, which are reaction products of phenols and aldehydes, with epihalohydrins. Examples of novolac-type epoxy resins include "Epotote YDPN-638" from Nippon Steel Chemical Co., Ltd., "Epicote 152" and "Epicote 154" from Mitsubishi Chemical Corporation, "Epiclon N-740," "Epiclon N-770," "Epiclon N-775," "Epiclon N-660," "Epiclon N-665," "Epiclon N-670," "Epiclon N-673," and "Epiclon N-695" from DIC Corporation, "Epotote YDCN-700 series" from Nippon Steel Chemical Co., Ltd., and "EOCN-1020," "EOCN-102S," and "EOCN-104S" from Nippon Kayaku Co., Ltd.

[0057] A glycidylamine-type epoxy resin specifically refers to an epoxy resin that contains a glycidylamino group in which one or two glycidyl groups are bonded to an amino group within the molecule. Examples of glycidylamine-type epoxy resins include N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, triglycidyl para-aminophenol, 1,3-bis(diglycidylaminomethyl)cyclohexane, and N,N,N',N'-tetraglycidyl-m-xylenediamine, with N,N,N',N'-tetraglycidyl-m-xylenediamine being preferred.

[0058] The epoxy resin content is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and even more preferably 1 to 10 parts by mass, per 100 parts by mass of polyester resin. A content above the lower limit provides sufficient curing effect and exhibits excellent adhesion and solder heat resistance. A content below the upper limit results in good low dielectric properties.

[0059] <Polycarbodiimide> The adhesive composition of the present invention may contain polycarbodiimide. The polycarbodiimide is not particularly limited as long as it has two or more carbodiimide bonds in its molecule. By using polycarbodiimide, the carboxyl groups of polyester resin or the epoxy groups of epoxy resin react with the carbodiimide bonds, improving heat resistance and adhesion.

[0060] In the adhesive composition of the present invention, the polycarbodiimide content is preferably 1 to 20 parts by mass, and more preferably 3 to 10 parts by mass, per 100 parts by mass of polyester resin. Setting the content above the lower limit can increase the crosslinking density, resulting in good solder heat resistance. Setting the content below the upper limit can achieve excellent solder heat resistance and low dielectric properties.

[0061] <Unsaturated Hydrocarbons> The adhesive composition of the present invention may contain unsaturated hydrocarbons having terminal unsaturated hydrocarbon groups and a 5% weight loss temperature of 260°C or higher. When unsaturated hydrocarbons are included, the presence of terminal unsaturated hydrocarbon groups increases the crosslinking density through a curing reaction caused by radicals generated by the use of radical generators, etc., thereby improving the solder heat resistance. Furthermore, since hydroxyl groups that worsen dielectric properties are not generated after the reaction, an adhesive with superior dielectric properties can be obtained. It is preferable that there be two or more terminal unsaturated hydrocarbon groups in one molecule, as this further increases the crosslinking density.

[0062] The 5% weight loss temperature of the unsaturated hydrocarbon must be 260°C or higher. Preferably, it is 270°C or higher, more preferably 280°C or higher, and even more preferably 290°C or higher. Having a 5% weight loss temperature above this value allows soldering to be performed without causing cosmetic defects even at temperatures exceeding the melting point of the solder. While there is no particular upper limit, 500°C is practical.

[0063] Unsaturated hydrocarbons preferably have an aromatic ring structure or an alicyclic structure as structural units. Having an aromatic ring structure or an alicyclic structure as structural units improves solder heat resistance and also provides excellent dielectric properties. In particular, it is preferable that the unsaturated hydrocarbon has an aromatic ring structure or an alicyclic structure as its backbone, and it is preferable that it is a polyphenylene ether or a cycloolefin polymer. Specific examples of polyphenylene ethers having terminal unsaturated hydrocarbon groups include SA-9000 from SABIC Corporation and OPE-2St from Mitsubishi Gas Chemical Company. Furthermore, cycloolefin polymers having terminal unsaturated hydrocarbon groups can be obtained by copolymerizing an olefin monomer having an unsaturated bond with an alicyclic olefin monomer.

[0064] The number-average molecular weight of the unsaturated hydrocarbon is preferably 500 to 100,000, more preferably 800 to 10,000, and even more preferably 1,000 to 5,000. Within this range, solubility in the solvent is good, and a uniform adhesive coating can be formed.

[0065] The unsaturated hydrocarbon content in the adhesive composition of the present invention is preferably 1 to 1,000 parts by mass, more preferably 2 to 500 parts by mass, even more preferably 3 to 200 parts by mass, and even more preferably 4 to 100 parts by mass, per 100 parts by mass of polyester resin. Within this range, excellent adhesion, compatibility with organic solvents, and solder heat resistance can be achieved simultaneously.

[0066] <Radical Generator> The adhesive composition of the present invention may contain a radical generator. Radicals generated by the radical generator efficiently react with terminal unsaturated hydrocarbon groups of unsaturated hydrocarbons, increasing the crosslinking density and thereby improving the solder's heat resistance and dielectric properties. The radical generator is not particularly limited, but it is preferable to use an organic peroxide. Examples of organic peroxides are not particularly limited, but include peroxides such as di-tert-butyl peroxyphthalate, tert-butyl hydroperoxide, dicumyl peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxypivalate, methyl ethyl ketone peroxide, di-tert-butyl peroxide, and lauroyl peroxide; and azonitriles such as azobisisobutyronitrile and azobisisopropionitrile.

[0067] The half-life temperature of the radical generator is preferably 140°C or higher. By setting the temperature to 140°C or higher, the radical reaction is prevented from starting when the solvent of the adhesive composition varnish is evaporated to produce the adhesive sheet, and excellent adhesion can be achieved.

[0068] The amount of the radical generating agent is preferably 0.1 to 50 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of unsaturated hydrocarbon. By keeping it within this range, an optimal crosslinking density can be achieved, and both adhesion and solder heat resistance can be attained.

[0069] <Organic Solvents> The adhesive composition of the present invention may further contain an organic solvent. The organic solvent used in the present invention is not particularly limited as long as it dissolves the polyester resin. When the adhesive composition of the present invention contains an organic solvent, it is desirable that the polyester resin is uniformly dissolved in the organic solvent.

[0070] Specifically, organic solvents include, for example, aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, octane, and decane; alicyclic hydrocarbons such as cyclohexane, cyclohexene, methylcyclohexane, and ethylcyclohexane; halogenated hydrocarbons such as trichloroethylene, dichloroethylene, chlorobenzene, and chloroform; alcoholic solvents such as methanol, ethanol, isopropyl alcohol, butanol, pentanol, hexanol, propanediol, and phenol; acetone, methyl isobutyl ketone, methyl ethyl ketone, pentanone, hexanone, cyclohexanone, isophorone, and acetophenone. Ketone solvents such as methyl cellsolve and ethyl cellsolve, ester solvents such as methyl acetate, ethyl acetate, butyl acetate, methyl propionate, and butyl formate, and glycol ether solvents such as ethylene glycol mono-n-butyl ether, ethylene glycol mono-iso-butyl ether, ethylene glycol mono-tert-butyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether, and tetraethylene glycol mono-n-butyl ether can be used, and these can be used alone or in combination of two or more. Methyl ethyl ketone, methylcyclohexane, or toluene are particularly preferred due to their work environment and drying properties.

[0071] The amount of organic solvent is preferably in the range of 100 to 1000 parts by mass per 100 parts by mass of solid content of the adhesive composition. Setting it above the lower limit results in good liquidity and pot life. Setting it below the upper limit is advantageous in terms of manufacturing and transportation costs.

[0072] Furthermore, the adhesive composition of the present invention may contain other components as needed. Specific examples of such components include flame retardants, tackifiers, fillers, antioxidants, and silane coupling agents.

[0073] <Flame retardant> The adhesive composition of the present invention may be blended with a flame retardant as needed. Examples of the flame retardant include bromine-based, phosphorus-based, nitrogen-based, metal hydroxide compounds, etc. Among them, phosphorus-based flame retardants are preferred, and phosphorus-based flame retardants such as phosphate esters, phosphates, phosphine oxides, etc. can be used. These can be used alone or in combination of two or more. When containing a flame retardant, it is preferably contained in the range of 1 to 70% by mass, more preferably in the range of 5 to 60% by mass, and most preferably in the range of 10 to 50% by mass based on 100% by mass of the solid content of the adhesive composition. By setting it within the above range, flame retardancy can be exhibited while maintaining adhesiveness, solder heat resistance, and electrical properties.

[0074] <Tackifier> The adhesive composition of the present invention may be blended with a tackifier as needed. Examples of the tackifier include polyterpene resins, rosin-based resins, aliphatic petroleum resins, alicyclic petroleum resins, copolymer-based petroleum resins, styrene resins, and hydrogenated petroleum resins, etc., which are used for the purpose of improving adhesive strength. These can be used alone or in combination of two or more. When containing a tackifier, it is preferably contained in the range of 1 to 70% by mass, more preferably in the range of 5 to 60% by mass, and most preferably in the range of 10 to 50% by mass based on 100% by mass of the solid content of the adhesive composition. By setting it within the above range, the effect of the tackifier can be exhibited while maintaining adhesiveness, solder heat resistance, and electrical properties.

[0075] <Filler> The adhesive composition of the present invention may be blended with a filler as needed. Examples of the organic filler include powders of heat-resistant resins such as polyimide, polyamideimide, fluororesin, liquid crystal polyester, etc. Also, examples of the inorganic filler include, for example, silica (SiO ２ ), alumina (Al ２ O ３ ), titania (TiO ２ ), tantalum oxide (Ta ２ O ５ ), zirconia (ZrO ２ ), silicon nitride (Si ３ N ４ ), boron nitride (BN), calcium carbonate (CaCO ３), calcium sulfate (CaSO4) ４ ), zinc oxide (ZnO), magnesium titanate (MgO・TiO ２ ), barium sulfate (BaSO ４ Examples include organic bentonite, clay, mica, aluminum hydroxide, and magnesium hydroxide, among which silica is preferred due to its ease of dispersion and its effect in improving heat resistance.

[0076] While hydrophobic and hydrophilic silica are generally known as silica, hydrophobic silica treated with dimethyldichlorosilane, hexamethyldisilazane, octylsilane, etc., is preferable here for imparting moisture resistance. When silica is incorporated, the amount is preferably 1 to 50% by mass, and more preferably 30 to 50% by mass, of the solid content of the adhesive composition. Increasing the amount above the lower limit can further enhance heat resistance. Conversely, keeping the amount below the upper limit prevents poor silica dispersion and excessively high solution viscosity, resulting in good workability.

[0077] <Antioxidant> The adhesive composition of the present invention may optionally contain an antioxidant. The inclusion of an antioxidant is preferable because it can suppress the deterioration of properties such as adhesion and dielectric properties even when used in high-temperature environments exposed to air. The antioxidant is not particularly limited, but examples include phenolic antioxidants, amine antioxidants, phosphorus antioxidants, and sulfur antioxidants. These may be used individually or in combination of two or more.

[0078] If the adhesive composition contains an antioxidant, its content is preferably 0.5 to 5 parts by mass, and more preferably 1 to 3 parts by mass, per 100 parts by mass of solid content of the adhesive composition. If the antioxidant content is within the above range, it is possible to suppress the deterioration of properties such as adhesion and dielectric properties even when used in a high-temperature environment exposed to air.

[0079] <Silane Coupling Agent> A silane coupling agent may be added to the adhesive composition of the present invention as needed. Adding a silane coupling agent is highly preferable because it improves the adhesion to metals and heat resistance properties. The silane coupling agent is not particularly limited, but examples include those having an unsaturated group, an epoxy group, or an amino group. Of these, silane coupling agents having an epoxy group, such as γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, are even more preferable from the viewpoint of heat resistance. When a silane coupling agent is added, the amount added is preferably 0.5 to 20% by mass of the solid content of the adhesive composition. By keeping it within this range, the heat resistance and adhesion of the solder can be improved.

[0080] <Laminate> In the present invention, a laminate is a substrate on which the adhesive composition of the present invention is laminated. Specifically, it is a substrate on which the adhesive composition is laminated (a two-layer laminate of substrate / adhesive layer), or a further laminate of substrates (a three-layer laminate of substrate / adhesive layer / substrate). Here, the adhesive layer refers to the layer of adhesive composition obtained after applying the adhesive composition of the present invention to a substrate and drying it. The laminate of the present invention can be obtained by applying the adhesive composition of the present invention to various substrates in accordance with conventional methods, drying it, and further laminating other substrates.

[0081] The laminates of the present invention include laminates in which the adhesive composition of the present invention is laminated onto a substrate which is a resin substrate, a metal substrate, paper, or an inorganic non-metallic substrate as described later, and laminates (adhesive sheets) in which the adhesive composition of the present invention is laminated onto a release substrate. Examples of the laminates of the present invention include copper-clad laminates (CCLs), resin-coated metal foils, coverlay films, bonding sheets, and the like.

[0082] <Substrate> The substrate in this invention is not particularly limited as long as it can be coated with the adhesive composition of the present invention, dried, and form an adhesive layer. Examples include resin substrates such as film-like resins, metal substrates such as metal plates and metal foils, papers, inorganic non-metallic substrates, and release substrates.

[0083] Examples of materials for the resin substrate include epoxy resin, polyester resin, polyamide resin, aramid resin, polyimide resin, polyamide-imide resin, liquid crystal polymer, polyphenylene sulfide, polyphenylene ether, polyethersulfone, polyetheretherketone, polycarbonate, polyarylate, syndiotactic polystyrene, polyolefin resin, fluororesin, and the like. The form of the resin substrate is not particularly limited, but examples include films made from the resin and glass cloth (FR-4) impregnated with the resin. The resin may contain fillers such as silica.

[0084] Any conventionally known conductive material usable for circuit boards can be used as the metal substrate. Examples of materials include various metals such as SUS, copper, aluminum, iron, steel, zinc, nickel, and their alloys, plated products, and metals treated with other metals such as zinc or chromium compounds. Preferably, it is a metal foil, and more preferably, it is a copper foil. There are no particular limitations on the thickness of the metal foil, but it is preferably 1 to 50 μm, more preferably 3 to 30 μm, and even more preferably 10 to 20 μm. If the thickness is too thin, it may be difficult to obtain sufficient electrical performance of the circuit, while if the thickness is too thick, the processing efficiency during circuit fabrication may decrease. Metal foil is usually provided in roll form. The form of the metal foil used when manufacturing the printed circuit board of the present invention is not particularly limited. When using a ribbon-shaped metal foil, its length is not particularly limited. Its width is also not particularly limited, but it is preferably about 250 to 500 cm. The surface roughness of the substrate is not particularly limited, but is preferably 0.1 to 3 μm, more preferably 0.2 to 2 μm, and even more preferably 0.3 to 1.5 μm.

[0085] Examples of paper types include high-quality paper, kraft paper, roll paper, and glassine paper.

[0086] Examples of inorganic non-metallic substrates include glass and ceramics.

[0087] The release substrate is not particularly limited, but examples include paper such as fine paper, kraft paper, roll paper, and glassine paper, on which layers of a sealant such as clay, polyethylene, or polypropylene are applied, and then a silicone-based, fluorine-based, or alkyd-based release agent is applied on each of these layers. Other examples include various olefin films such as polyethylene, polypropylene, ethylene-α-olefin copolymer, and propylene-α-olefin copolymer, applied alone, and films such as polyethylene terephthalate on which the release agent is applied.

[0088] In the present invention, the method for coating the adhesive composition onto a substrate is not particularly limited, but examples include a comma coater, a reverse roll coater, a die coater, etc. Alternatively, if necessary, the adhesive layer can be applied directly or by transfer to the rolled copper foil, which is a component material of the printed circuit board, or to the resin substrate. The thickness of the adhesive layer after drying can be changed as needed, but is preferably in the range of 5 to 200 μm. Sufficient adhesive strength can be obtained by setting it to be above the lower limit of the adhesive film thickness. Also, setting it to be below the upper limit makes it easier to control the amount of residual solvent in the drying process, and blistering is less likely to occur when pressing the printed circuit board. The drying conditions are not particularly limited, but the residual solvent rate after drying is preferably 1% by mass or less. Setting it to 1% by mass or less suppresses foaming of the residual solvent when pressing the printed circuit board, and blistering is less likely to occur.

[0089] <Copper-clad laminate (CCL)> In the present invention, a copper-clad laminate (CCL) is a laminate in which the metal foil is laminated on one or both sides of the resin substrate. The resin substrate and the metal foil may be laminated via the adhesive composition of the present invention, or they may be laminated by thermocompression bonding without the adhesive composition of the present invention. Specific configurations of the copper-clad laminate (CCL) include a metal foil layer / adhesive layer / resin substrate layer / adhesive layer / metal foil layer, etc. By etching the metal foil layer to form a circuit pattern, it can be used as a laminate material for printed wiring boards.

[0090] <Resin-Coated Metal Foil> In the present invention, resin-coated metal foil refers to a metal foil on which an adhesive layer, which is a cured product of the adhesive composition of the present invention, is laminated on one side. Specific configurations include a metal foil layer / adhesive layer or a metal foil layer / adhesive layer / release substrate. The metal foil is preferably copper foil. Since the adhesive layer in the resin-coated metal foil can be laminated with the resin substrate, the resin-coated metal foil can be used as a material when manufacturing the CCL.

[0091] <Coverlay Film> In the present invention, a coverlay film is obtained by laminating the resin substrate and the release substrate via the adhesive composition of the present invention. As the resin substrate in the coverlay film, any conventionally known insulating film for printed circuit boards can be used. Preferred resins for the resin substrate include polyester resin, aramid resin, polyimide resin, polyamide-imide resin, liquid crystal polymer, polyphenylene sulfide, polyethersulfone, polyetheretherketone, polycarbonate, polyarylate, syndiotactic polystyrene, and polyolefin resins, with films composed of polyimide resin, liquid crystal polymer, and fluororesin being more preferred. The coverlay film can be manufactured by coating the resin substrate with the adhesive composition of the present invention, drying it, and then laminating the release substrate on top of it.

[0092] <Bonding Sheet> In the present invention, a bonding sheet is a sheet on which the adhesive composition of the present invention is laminated onto the release substrate. Specific configurations include release substrate / adhesive layer / release substrate, or release substrate / adhesive layer / substrate (excluding the release substrate) / adhesive layer / release substrate, etc. The laminated release substrate functions as a protective layer for the substrate. Furthermore, by using the release substrate, the release substrate can be peeled off the bonding sheet and used for bonding between other substrates. As for the release substrate in the bonding sheet, from the viewpoint of visibility during the manufacture of printed circuit boards, it is preferable that at least one side of the release substrate laminated on the outermost layer of the bonding sheet is opaque.

[0093] <Printed Wiring Boards> The adhesive composition of the present invention is preferably used for printed wiring boards. The printed wiring board in the present invention includes a laminate as a component having a metal substrate (metal foil) that forms a conductive circuit and a resin substrate. The printed wiring board in the present invention is a general term for so-called rigid substrates, flexible printed circuit boards (FPCs), flat cables, circuit boards for automated tape bonding (TAB), etc.

[0094] The printed circuit board of the present invention can have any laminate configuration that can be used as a printed circuit board. Preferably, the printed circuit board of the present invention includes a laminate as a component, in which the adhesive composition of the present invention is laminated on a substrate which is a resin substrate, a metal substrate, paper, or an inorganic non-metallic substrate. If necessary, a configuration in which two or more of the above printed circuit boards are laminated can be used. Also, if necessary, a configuration in which two or three or more bonding sheets are laminated on top of the protective layer of the printed circuit board, and a protective layer such as a coverlay film or solder resist is provided thereon. For example, using the laminate such as CCL, a printed circuit board can be made consisting of four layers such as a resin substrate layer / adhesive layer / metal foil layer / coverlay film layer, or a resin substrate layer / metal foil layer / adhesive layer / coverlay film layer. Alternatively, a printed circuit board can be made consisting of five layers: a resin substrate layer / adhesive layer / metal foil layer / adhesive layer / coverlay film layer.

[0095] Circuit formation on a metal substrate (metal foil layer) can be carried out using conventionally known methods. An additive method or a subtractive method may be used. Preferably, a subtractive method is used.

[0096] The printed circuit board of the present invention can be manufactured using any conventionally known process, except for using the materials of each layer described above. For example, a circuit pattern can be formed on a three-layer CCL with adhesive or a two-layer CCL without adhesive, and then laminated by bonding it with another CCL using a bonding sheet or prepreg and heat curing. After that, a multilayer printed circuit board can be obtained by performing processes such as drilling, through-hole plating, and copper foil pattern formation, followed by forming a protective layer such as a coverlay film or solder resist on the outermost layer and then performing further surface treatment.

[0097] The adhesive composition of the present invention can be suitably used in the manufacture of printed circuit boards, and specifically in each adhesive layer of a printed circuit board. Furthermore, because it has high adhesion to low-polarity resin substrates such as liquid crystal polymers, polyphenylene sulfide, syndiotactic polystyrene, and polyolefin resins, solder reflow resistance can be obtained. The adhesive layer itself also has excellent low dielectric properties, making it possible to produce a printed circuit board with excellent high-frequency characteristics.

[0098] <Laminated Film for Decorating Three-Dimensional Molded Products> The "laminated film for decorating three-dimensional molded products" in this invention is a film used in decorative molding of three-dimensional molded products. That is, a film with design properties is adhered to various molded bodies to impart design properties or surface protection functions to the molded bodies. In doing so, the film is deformed to conform to the surface of the three-dimensional shape and adheres tightly to it.

[0099] The adhesive composition of the present invention can be suitably used as an adhesive for laminated films used to decorate three-dimensional molded products. That is, the laminated film used to decorate three-dimensional molded products can include a layer formed from the adhesive composition of the present invention as a constituent element. The adhesive composition of the present invention has high adhesion to conventional resin substrates such as flexible polyvinyl chloride film, polycarbonate film, polyester film, and ABS that constitute the laminated film used to decorate three-dimensional molded products, and also has excellent sheet life. Therefore, the adhesive composition of the present invention is suitable as an adhesive composition for use in laminated films used to decorate three-dimensional molded products, such as automotive exterior components such as side under skirts, side garnishes, and door mirrors, automotive interior components such as instrument panels and door switch panels, and housings for home appliances such as refrigerators, mobile phones, and lighting fixtures.

[0100] <Film for Metal Can Lamination> The adhesive composition of the present invention can be suitably used as an adhesive for metal can lamination films. That is, a metal can lamination film can include a layer formed from the adhesive composition of the present invention as a constituent element. The adhesive composition of the present invention has high adhesion to conventional polyester films that constitute metal can lamination films and to metal substrates such as tinplate, tin-free steel, and aluminum that constitute metal cans, and also has excellent pot life. For this reason, the adhesive composition of the present invention is suitable as an adhesive composition to be used in each adhesive layer of a metal can lamination film.

[0101] <Packaging Materials> The adhesive composition of the present invention can be suitably used as an adhesive for packaging materials. That is, packaging materials can include layers formed from the adhesive composition of the present invention as constituent elements. The adhesive composition of the present invention has high adhesion to plastic films such as polyethylene terephthalate, polyethylene naphthalate, polyvinyl chloride resin, ABS resin, acrylic resin, and polycarbonate resin, which are commonly used in packaging materials, as well as gas barrier substrates such as aluminum foil, and also exhibits excellent pot life. Therefore, the adhesive composition of the present invention is suitable as an adhesive composition to be used in each adhesive layer of packaging materials.

[0102] This application claims the benefit of priority based on Japanese Patent Applications No. 2024-171170, No. 2024-171171, and No. 2024-171172, filed on 30 September 2024. The entire contents of the specifications of Japanese Patent Applications No. 2024-171170, No. 2024-171171, and No. 2024-171172, filed on 30 September 2024, are incorporated herein by reference.

[0103] The present invention will be described in more detail below with reference to examples, but the present invention is not limited by the following examples, and it is certainly possible to implement it with appropriate modifications within the scope that is consistent with the spirit of the preceding and following descriptions, and all such modifications are included within the technical scope of the present invention. In the following, unless otherwise specified, "parts" means "parts by mass" and "%" means "percent mass".

[0104] <Evaluation of Polyester Resin> (1) The resin composition sample was alkaline-decomposed with sodium hydroxide in a mixed solvent of deuterium methanol / dimethyl sulfoxide-d6, and the decomposition solution was diluted with heavy water. Nuclear magnetic resonance (NMR) spectrometer (Bruker "AVANCE NEO 600") and data processing were performed using Bruker TopSpin® 4.0 software. １ ¹H-NMR measurements were performed. The measurements were conducted under the following conditions: resonance frequency of 600 MHz, waiting time of 1 sec, number of integrations of 64, measurement temperature of 303 K, and a reference level of heavy water at 4.74 ppm. The resin composition was calculated in moles from the integral ratio. The integral value of the terephthalic acid peak detected at 7.89 ppm was set to 100. Note that even if the monomer is not terephthalic acid (for example, isophthalic acid or orthophthalic acid), if the position of the proton peak in NMR is clear, it can be used as a reference for the resin composition, and in that case, the integral value of the proton peak of that monomer can be set to 100. The same applies to the "content of TMA triester compounds" described later.

[0105] (2) Reduced viscosity (ηsp / c) 0.1 g of the sample was dissolved in 25 ml of a mixed solvent of phenol / tetrachloroethane (weight ratio 6 / 4), and measured at 30°C using an Ubbelohde viscometer.

[0106] (3) GPC The sample was dissolved or diluted in tetrahydrofuran to a sample concentration of approximately 0.5%, and filtered through a polytetrafluoroethylene membrane filter with a pore size of 0.5 μm to be used as the measurement sample. The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of the sample were measured by gel permeation chromatography using tetrahydrofuran as the mobile phase and a differential refractometer as the detector, and the degree of dispersion (Mw / Mn) was calculated. The flow rate was 1 mL / min and the column temperature was 30°C. Showa Denko "KF-802", "KF-804L", and "KF-806L" columns were used. Monodisperse polystyrene was used as the molecular weight standard. The number-average molecular weight (Mn) was calculated by excluding the portion corresponding to a molecular weight of less than 1000.

[0107] (4) Hydroxyl Value (OHV) The sample was dissolved in chloroform-d alone and in a mixed solvent of chloroform-d and trifluoroacetic acid, and nuclear magnetic resonance (NMR) was performed using a Bruker AVANCE NEO 600 and Bruker TopSpin® 4.0 software for data processing, using each solvent. １ ¹H-NMR measurements were performed, the integral values ​​were determined, and the hydroxyl value was calculated by averaging these values.

[0108] (5) Glass transition temperature (Tg) was measured using a differential scanning calorimeter (SII "DSC-200"). 5 mg of the sample was placed in an aluminum container with a retaining lid and sealed. It was cooled to -50°C using liquid nitrogen, and then heated to 150°C at a rate of 20°C / min. In the endothermic curve obtained during this process, the temperature at the intersection of the baseline before the endothermic peak and the tangent line toward the endothermic peak was defined as the glass transition temperature.

[0109] (6) Amount of unreacted TMA: 160 mg of the sample was dissolved in chloroform, then low-moisture methanol was added and allowed to stand for 36 hours to methylate the anhydrous ring. The supernatant was filtered through a PTFE filter, and the dried residue was dissolved in DMAc. The sample was analyzed using a Shimadzu HPLC to identify the amount of unreacted TMA in the polyester resin. Column: Inertsil ODS-2 5 μm 4.0 mm × 250 mm Mobile phase: A 0.4% phosphoric acid, B acetonitrile Flow rate: 1.0 mL / min Injection volume: 10 μL Detection wavelength: 258 nm

[0110] (7) Samples containing the triester compound of TMA were dissolved in a mixed solvent of chloroform-d / 1,1,1,3,3,3-Hexafluoro-2-propanol-d2 / triethylamine (90 / 10 / 1), and nuclear magnetic resonance (NMR) was performed using a Bruker AVANCE NEO 600 spectrometer and Bruker TopSpin® 4.0 software for data processing. １ 1H-NMR and TOCSY spectral measurements were performed. １ The 1H-NMR measurements were performed under the following conditions: resonance frequency of 600.13 MHz, waiting time of 1 sec, number of integrations of 64, measurement temperature of 303 K, and reference level of chloroform at 7.33 ppm. １When the integral value of TPA detected at 8.12 ppm in 1H-NMR was set to 100, the integral value of the peak detected at 7.75–7.85 ppm was defined as Hc. Measurement by the TOCSY method was performed under the following conditions: resonance frequency 600.13 MHz, waiting time 2 sec, pulse width 2.5 msec, mixing time 0.05 sec, number of integrations 16 times, measurement temperature 303 K, and reference chloroform 7.3 ppm. The integral values ​​of the peaks observed at (F1 axis, F2 axis) = (7.8, 8.2) and (7.8, 8.1) in the TOCSY spectrum were defined as Ha and Hb, respectively, and X was calculated using the following formula, with (1) composition mol ratio of terephthalic acid obtained from the resin composition: Hd. Hc is the integral value including components derived from the triester of TMA. By measuring using the TOCSY method, the Hc component is separated into Ha and Hb, and Ha is the integral value containing only the triester. X = Hd / 100 × 4 × Hc × (Ha / (Ha + Hb)) Let X be the content (mol%) of the triester of TMA.

[0111] (8) Acid value (AV) 0.2 g of the sample was dissolved in 20 ml of chloroform and titrated with a methanol solution of 0.1 N sodium methoxide in the presence of phenolphthalein indicator. The point at which the solution turned red was defined as the neutralization point, and the value was converted to the equivalent amount per ton of sample (eq / t).

[0112] (9) Acid value (AV) derived from dicarboxylic acid components ｄ The sample was dissolved in a mixed solvent of chloroform-d / 1,1,1,3,3,3-Hexafluoro-2-propanol-d2 / triethylamine, and nuclear magnetic resonance (NMR) was performed using a Bruker AVANCE NEO 600 spectrometer and Bruker TopSpin® 4.0 software for data processing. １ 1H-NMR measurements were performed, and the content derived from the dicarboxylic acid component was determined from the integrated value, which was then converted into an acid value per ton of sample.

[0113] (10) Amount of Metal Components The amount of metal components contained in the polyester resin was determined based on the following procedure. The polyester resin was weighed into a platinum crucible, carbonized on an electric stove, and then ashed in a muffle furnace at 550°C for 8 hours. The ashed sample was dissolved in 1.2 M hydrochloric acid to prepare the sample solution. The prepared sample solution was measured under the following conditions, and the concentrations of antimony, titanium, and zinc in the polyester resin were determined by high-frequency inductively coupled plasma atomic emission spectrometry. Apparatus: SPECTRO CIROS-120 Plasma output: 1400 W Plasma gas: 13.0 L / min Auxiliary gas: 2.0 L / min Nebulizer: Cross-flow nebulizer Chamber: Cyclone chamber Measurement wavelength: 167.078 nm

[0114] (11) Ratio of Triester Forms and Ratio of Mono- or Diester Forms The ratio of triesters was determined from the following formula (a) using the triester content (T, mol%) obtained in "(7) Content of Tryters of TMA" and the TMA ratio (T0, mol%) in the polycarboxylic acid component subjected to the esterification reaction. The ratio of mono- or diester forms was determined from the following formula (b). Ratio of triesters (%) = T / T0 × 100 …(a) Ratio of mono- or diester forms (%) = 100 - Ratio of triesters (%) …(b)

[0115] (12) 5 g of foreign polyester resin was added to 80 mL of a phenol / tetrachloroethane (6 / 4 (mass ratio)) mixed solvent and stirred at 135°C for 2 hours to dissolve. Next, the solution was filtered through a polytetrafluoroethylene (PTFE) filter with a pore size of 0.5 μm, and the filtered filtrate was observed (visually) using a SEM-EDX (JEOL Ltd. "JSM-6510A", magnification: 100x, signal: SEI (secondary electron image), focal length: 10 mm, applied voltage: 15 kV, vacuum mode: 0.1 mPa) and the number of foreign particles was counted. ○: There were 10 or fewer foreign particles ×: 11 or more foreign particles were identified

[0116] (13) Thermal stability of polyester resin immediately after late polymerization ０ The reduced viscosity η of the polyester resin immediately after vacuum breaking following late polymerization and stirring for 1 hour under a nitrogen atmosphere.１ Determine the change in reduced viscosity (%), {(η ０ -η １ ) / η ０ The result (} × 100) was calculated and judged as ◎, ○, △, or × based on the following evaluation criteria: ◎: Within ±5% ○: Over ±5% and within ±8% △: Over ±8% and within ±10% ×: Outside the above range

[0117] (14) Storage Stability: Polyester resin was stored in a constant temperature room set at 25°C for one month, and the change in reduced viscosity was determined. A judgment of ◎, ○, △, or × was made based on the evaluation criteria below. The change in reduced viscosity (%) is the same as the reduced viscosity η of the polyester resin before storage. ２ , the reduced viscosity of polyester resin after storage η ３ When this is the case, {(η ２ -η ３ ) / η ２ The result was calculated using the formula: (} × 100). ◎: Within ±5% ○: Over ±5% and within ±8% △: Over ±8% and within ±10% ×: Outside the above range

[0118] <Evaluation of Adhesive Composition> (15) The humidified solder adhesive composition was applied to a 12.5 μm thick polyimide film (Kaneka's "Apical®"), leaving a tensile allowance so that the thickness after drying would be 25 μm, and dried at 140°C for 5 minutes to obtain an adhesive film (B-stage product). The adhesive layer surface of the adhesive film was bonded to a 20 μm rolled copper foil so that its glossy surface was in contact with it, and the film was heated at 160°C at 35 kgf / cm². ２ The samples were pressed under pressure for 30 seconds to bond. Then, they were heat-treated at 140°C for 4 hours to cure, and a sample for evaluating the coverlay structure was obtained. The sample for evaluating the coverlay structure was left at 40°C and 80% humidity for 3 days, and then floated in a heated solder bath with the copper surface in contact for 1 minute. The upper limit temperature at which blistering did not occur was measured in 10°C increments. Specifically, the temperature was increased from 220°C to 230°C, 240°C, and so on, up to 300°C in 10°C increments. In this test, a higher measured value indicates better heat resistance, but it is also necessary to suppress the impact caused by the evaporation of water vapor contained in each substrate and adhesive layer, requiring even stricter heat resistance than in a dry state.

[0119] (16) The normal solder adhesive composition was applied to the release surface of a PET film (Toyobo "TN200") so that the thickness after drying was 25 μm, and dried at 140°C for 5 minutes to obtain an adhesive film (B stage product). The adhesive layer surface of the adhesive film was bonded to the polyimide film surface with one side CCL in contact, and bonded at 140°C at 20 kgf / cm². ２ The film was pressed under pressure for 30 seconds to bond. Next, the PET film was peeled off and the copper foil side of the single-sided CCL was attached to the other adhesive layer surface of the adhesive film, and then heated at 180°C at 35 kg / cm². ２ The bonded sheet was pressed under pressure for 3 hours to bond and cure, obtaining a sample for evaluating the bonding sheet structure. After leaving the evaluation sample of the bonding sheet structure at 25°C and a 60% atmosphere for 1 day, the copper surface was floated in a heated solder bath for 1 minute, and the upper limit temperature at which blistering did not occur was measured in 10°C increments. Specifically, heating started at 260°C and increased in 10°C increments to 270°C, 280°C, and up to 340°C. In this test, a higher measured value indicates better heat resistance.

[0120] <Example 1> In a 3 L four-necked flask, 186 parts terephthalic acid, 469 parts isophthalic acid, 40 parts trimellitic anhydride (TMA), 139 parts 2-methyl-1,3-propanediol, 323 parts 1,6-hexanediol, and 0.14 parts tetra-n-butyl titanate were charged. The temperature was then gradually increased to 250°C over 5 hours to carry out the esterification reaction. Subsequently, while maintaining the temperature at 250°C, the pressure was reduced to 10 mmHg over 20 minutes to carry out initial polymerization, and then the pressure was reduced to below 1 mmHg for 70 minutes to carry out later polymerization. After that, the vacuum was broken to obtain a polyester resin. The composition and various properties of the finally obtained polyester resin are shown in Tables 1 and 2.

[0121] 160 parts of the obtained polyester resin and 240 parts of methyl ethyl ketone were charged into a 1 L flask. The mixture was heated to 40°C and stirred for 5 hours until completely dissolved. After confirming dissolution, the mixture was removed to obtain polyester varnish. To 100 parts of the solids content of the polyester varnish, 9 parts of YDCN-700-10 (novolac-type epoxy resin) manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd. and 0.1 parts of TETRAD®-X (N,N,N',N'-tetraglycidyl-m-xylenediamine) manufactured by Mitsubishi Gas Chemical Co., Ltd. were added as epoxy resins. The solids content was then adjusted to 35% using methyl ethyl ketone to obtain an adhesive composition.

[0122] <Example 2> In a 3 L four-necked flask, 172 parts terephthalic acid, 483 parts isophthalic acid, 40 parts trimellitic anhydride, 141 parts 2-methyl-1,3-propanediol, 330 parts 1,6-hexanediol, and 0.07 parts tetra-n-butyl titanate were charged. The polyester resin was obtained in the same manner as in Example 1.

[0123] <Example 3> In a 3 L four-necked flask, 172 parts terephthalic acid, 483 parts isophthalic acid, 40 parts trimellitic anhydride, 140 parts 2-methyl-1,3-propanediol, 326 parts 1,6-hexanediol, and 0.07 parts tetra-n-butyl titanate were charged. The polyester resin was obtained in the same manner as in Example 1.

[0124] <Example 4> In a 3 L four-necked flask, 194 parts terephthalic acid, 478 parts isophthalic acid, 24 parts trimellitic anhydride, 141 parts 2-methyl-1,3-propanediol, 328 parts 1,6-hexanediol, and 0.07 parts tetra-n-butyl titanate were charged. The polyester resin was obtained in the same manner as in Example 1.

[0125] <Example 5> In a 3 L four-necked flask, 194 parts terephthalic acid, 485 parts isophthalic acid, 16 parts trimellitic anhydride, 137 parts 2-methyl-1,3-propanediol, 333 parts 1,6-hexanediol, and 0.07 parts tetra-n-butyl titanate were charged. The polyester resin was obtained in the same manner as in Example 1.

[0126] <Example 6> In a 3 L four-necked flask, 364 parts terephthalic acid, 387 parts isophthalic acid, 27 parts trimellitic anhydride, 153 parts ethylene glycol, 238 parts neopentyl glycol, and 0.16 parts tetra-n-butyl titanate were charged. The polyester resin was obtained in the same manner as in Example 1. In Example 6, the glass transition temperature (Tg) of the polyester resin was higher than in Example 1 due to the influence of the diol component, but the obtained polyester resin had excellent thermal stability and solder heat resistance.

[0127] <Example 7> In a 3 L four-necked flask, 352 parts terephthalic acid, 150 parts isophthalic acid, 26 parts trimellitic anhydride, 273 parts sebacic acid, 173 parts ethylene glycol, 193 parts neopentyl glycol, and 0.15 parts tetra-n-butyl titanate were charged. The polyester resin was obtained in the same manner as in Example 1. In Example 7, an aliphatic dicarboxylic acid was copolymerized as the dicarboxylic acid component, but the obtained polyester resin had excellent thermal stability and solder heat resistance.

[0128] <Example 8> A polyester resin was obtained in the same manner as in Example 4, except that 0.07 parts of tetra-n-butyl titanate used in the esterification reaction was replaced with 0.07 parts of tetra-n-butyl titanate and 0.135 parts of zinc acetate dihydrate. Although the polyester resin contained a small amount of zinc, the obtained polyester resin exhibited excellent thermal stability and solder heat resistance.

[0129] <Comparative Example 1> In a 3 L four-necked flask, 208 parts terephthalic acid, 479 parts isophthalic acid, 8 parts trimellitic anhydride, 148 parts 2-methyl-1,3-propanediol, 345 parts 1,6-hexanediol, and 0.14 parts tetra-n-butyl titanate were charged. The polyester resin was obtained in the same manner as in Example 1. The G / A ratio of the charged mixture was high, and the acid value (AV) and acid value (AVd) could not be sufficiently increased, resulting in poor solder heat resistance.

[0130] <Comparative Example 2> In a 3 L four-necked flask, 204 parts terephthalic acid, 471 parts isophthalic acid, 4 parts TMA, 294 parts 2-methyl-1,3-propanediol, 579 parts 1,6-hexanediol, and 0.40 parts tetra-n-butyl titanate were charged. The temperature was then gradually increased to 250°C over 4 hours to carry out the esterification reaction. After that, while maintaining the temperature at 250°C, the pressure was reduced to 10 mmHg over 30 minutes to carry out initial polymerization, and then the pressure was reduced to below 1 mmHg for 90 minutes to carry out later polymerization, thereby polymerizing the prepolymer. When the reduced viscosity of the prepolymer reached 0.54 dl / g, the vacuum was broken. Next, 24 parts TMA was added under a nitrogen atmosphere at 230°C, and the mixture was stirred for 60 minutes to obtain a polyester resin. The acid value (AV) of the obtained polyester resin was ｄ The performance was low, and good results were not obtained in terms of thermal stability and storage stability. Furthermore, the solder heat resistance was also poor.

[0131]

[0132]

[0133] In Tables 1 and 2, the abbreviations are used with the following meanings: "TPA": Terephthalic acid "IPA": Isophthalic acid "TMA": Trimellitus anhydride "SA": Sebacic acid "EG": Ethylene glycol "NPG": Neopentyl glycol "2MG": 2-Methyl-1,3-propanediol "HD": 1,6-Hexanediol "Ti": Titanium "Zn": Zinc

[0134] The polyester resin of the present invention has high reducing viscosity or high Mw, while also being capable of forming a high crosslink density. The adhesive composition containing the polyester resin of the present invention is useful as an adhesive composition for printed circuit boards, as well as as an adhesive sheet, laminate, and printed circuit board containing the same.

Claims

1. A polyester resin characterized by containing 0.5 to 10.0 mol% of trivalent or higher polycarboxylic acid components out of 100 mol% of the total polycarboxylic acid components, having an acid value (AV) of 100 eq / t or more, and satisfying the following (i) and / or (ii): (i) The reduced viscosity of the polyester resin is 0.50 dl / g or more; (ii) The weight-average molecular weight (Mw) of the polyester resin is 79,000 or more.

2. Acid value (AV) of the carboxyl group belonging to the dicarboxylic acid component constituting the main chain of polyester. ｄ The polyester resin according to claim 1, wherein the ratio is 100 eq / t or more.

3. The polyester resin according to claim 1, wherein the proportion of tricarboxylic acid components in which three carboxyl groups form an ester bond is 60% or more among the polycarboxylic acid components with three or more valent values.

4. The polyester resin according to claim 1, wherein the amount of unreacted tricarboxylic acid monomer is 500 ppm or less.

5. The polyester resin according to claim 1, wherein the antimony content in the polyester resin is 150 ppm or less.

6. The polyester resin according to claim 1, wherein the polycarboxylic acid component with three or more valent values ​​is a tricarboxylic acid component.

7. The polyester resin according to claim 1, comprising one or more dicarboxylic acid components selected from the group consisting of aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and aromatic dicarboxylic acids as the dicarboxylic acid component constituting the polyester resin.

8. The polyester resin according to claim 1, wherein the hydroxyl value (OHV) is 70 to 400 eq / t.

9. The polyester resin according to claim 1, wherein the glass transition temperature (Tg) is 0 to 80°C.

10. The polyester resin according to claim 1, wherein the polycarboxylic acid component with tetravalent or higher is present in 100 mol% of the polycarboxylic acid component, and the amount of this polycarboxylic acid component is 6 mol% or less.

11. An adhesive composition comprising the polyester resin according to any one of claims 1 to 10.

12. The adhesive composition according to claim 11, which is for printed circuit boards.

13. An adhesive sheet in which the adhesive composition described in claim 11 is laminated onto a release substrate.

14. A laminate in which the adhesive composition according to claim 11 is laminated onto a substrate which is a resin substrate, a metal substrate, paper, or an inorganic nonmetallic substrate.

15. A printed circuit board comprising the laminate described in claim 14 as a component.

16. A laminated film for decorating a three-dimensional molded article, comprising a layer formed from the adhesive composition described in claim 11 as a constituent element.

17. A film for laminating metal cans, comprising a layer formed from the adhesive composition described in claim 11 as a constituent element.

18. A packaging material comprising a layer formed from the adhesive composition described in claim 11 as a component.

19. A method for producing a polyester resin having an acid value (AV) of 100 eq / t or more, comprising: 1) a step of esterifying a polycarboxylic acid component and a polyhydric alcohol component; and 2) a step of polycondensing the reaction product obtained in step 1), wherein no acid addition step or depolymerization step is performed after step 2).

20. The manufacturing method according to claim 19, wherein the acid value (AV) of the polyester resin is 200 eq / t or more.

21. The manufacturing method according to claim 19, wherein the reduced viscosity of the polyester resin is 0.52 dl / g or more.

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