JP7115478B2 - adhesive composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an adhesive composition having excellent adhesiveness, coatability and solvent resistance. More specifically, it relates to a wet-process film-laminated sheet and a polishing pad using the same. The present invention relates to a polishing pad suitable for precision polishing of the surfaces of electronic components such as liquid crystal glass, glass discs, photomasks, silicon wafers, and CCD cover glasses.

A wet-processed film-laminated sheet obtained by laminating a wet-processed urethane honeycomb-shaped porous film (hereinafter referred to as a wet-processed film) on a polyester film has been conventionally used as a polishing pad for precision surface polishing of electronic components. ing.

Conventionally, a wet-laid film laminated sheet as described above is produced by coating a polyester film with a solution of a polyurethane prepolymer to form a wet-laid film, and then peeling this film from the polyester film to form another polyester film. It was obtained by pasting with an adhesive on top. In the case of forming a polishing pad, the skin layer of the wet film is previously removed by grinding, polishing, or the like to form a suede-like film, which is attached to another polyester film. As described above, the wet film is once peeled from the polyester film and attached to another polyester film with an adhesive because the conventional polyester film and the wet film have poor adhesion to each other and can be This is because it could not be used as a polishing pad or the like as it was. However, in the above method, when the wet-processed film is peeled off from the polyester film, the wet-processed film is likely to be deformed, and sometimes torn or cut. Therefore, the type of polyurethane used was limited, and the thickness of the wet film was also limited. In addition, polishing pads for precision polishing are required to have flatness (surface irregularities) precision, and in recent years, along with the development of precision polishing surface measuring equipment, the quality demanded by users is increasing. Polishing pads with higher precision are becoming more and more necessary, but when a wet film is pasted on a polyester film using an adhesive as described above, unevenness of the adhesive affects the surface of the wet film, resulting in poor flatness. There was also the problem of poor accuracy.

There is also provided a wet-processed film-laminated sheet that can be obtained without the process of once peeling the wet-processed film from the polyester film and attaching it to another polyester film, and that can achieve high precision when used as a polishing pad (for example, patent Reference 1).

Japanese Patent No. 3723897

However, in the above method, the substrate film is limited, and furthermore, there is a problem that re-stretching and heat setting are required after applying the easy-adhesive water-based coating liquid.

INDUSTRIAL APPLICABILITY The present invention is an adhesive composition excellent in adhesiveness, coatability, and solvent resistance, which satisfactorily bonds a urethane porous layer and a base film. The adhesive composition of the present invention can be applied to any substrate film, and the wet-processed film laminated sheet and the polishing pad can be prepared without the process of once peeling the wet-processed film from the polyester film and attaching it to another polyester film as described above. Obtainable.

As a result of intensive studies, the inventors of the present invention have found that the above problems can be solved by means shown below, and have completed the present invention. That is, the present invention consists of the following configurations.

an amorphous polyester resin (A) having a number average molecular weight of 5,000 to 40,000, a glass transition temperature of 20° C. or less, and an acid value of 5 to 400 equivalents/10 ⁶ g; an adhesive composition comprising an amorphous polyurethane resin (B) having a temperature of 50° C. or higher, and a polyisocyanate (C).

The amorphous polyester resin (A) preferably has two or more carboxyl groups at the resin terminal, and the blending ratio of the amorphous polyester resin (A) and the amorphous polyurethane resin (B) is It is preferable that the amount of the amorphous polyurethane resin (B) is 5 parts by mass or more and 70 parts by mass or less per 100 parts by mass of the crystalline polyester resin (A).

A laminate obtained by laminating an adhesive layer made of the adhesive composition and a plastic film. A laminate in which a resin is further laminated on the surface of the adhesive layer. A polishing pad comprising a polishing layer as a part of the laminate.

The adhesive composition of the present invention is excellent in adhesiveness between the urethane porous layer and the base film, and is also excellent in coatability and solvent resistance. Furthermore, the adhesive composition of the present invention can be applied to any substrate film, and it is possible to obtain a wet-processed film laminated sheet and a polishing pad without the process of once peeling the wet-processed film from the polyester film and attaching it to another polyester film. can be done.

<Amorphous polyester resin (A)>
The amorphous polyester resin (A) used in the present invention is preferably a polyester having a polycarboxylic acid component and a polyhydric alcohol component as copolymer components, and a dicarboxylic acid component and a glycol component as copolymer components. is more preferable.

The dicarboxylic acid component constituting the amorphous polyester resin (A) is not particularly limited, but includes aromatic dicarboxylic acids, aliphatic dicarboxylic acids and alicyclic dicarboxylic acids, particularly aromatic dicarboxylic acids and aliphatic dicarboxylic acids. It is preferable to use an acid together.

The amount of copolymerized aromatic dicarboxylic acid is preferably 50 mol % or more, more preferably 60 mol % or more, when the total amount of carboxylic acid components is 100 mol %. If the content is too small, the moist heat resistance may deteriorate. Moreover, 90 mol% or less is preferable, and 80 mol% or less is more preferable. If it is too large, the adhesion to the substrate may be lowered.

Specific examples of the aromatic dicarboxylic acid include, but are not limited to, terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, 4,4′-diphenyldicarboxylic acid, 2,2 '-Diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid and the like can be mentioned, and these can be used alone or in combination of two or more. Among these, terephthalic acid and isophthalic acid are particularly preferred from the viewpoint of resistance to moisture and heat.

Although the aliphatic dicarboxylic acid is not particularly limited, it is preferable to use an aliphatic dicarboxylic acid having 4 to 18 carbon atoms. The aliphatic dicarboxylic acid preferably has 5 or more carbon atoms, and more preferably 6 or more carbon atoms. Moreover, it is more preferable to have 10 or less carbon atoms. The copolymerization amount of the aliphatic dicarboxylic acid is preferably 50 mol % or less, more preferably 40 mol % or less, when the total amount of the carboxylic acid components is 100 mol %. If it is too large, the moist heat resistance may be lowered. Moreover, it is preferably 10 mol % or more, more preferably 20 mol % or more. If the amount is too small, the adhesion to the substrate may deteriorate.

Specific examples of the aliphatic dicarboxylic acid include, but are not limited to, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, octadecanedioic acid, and the like, and these may be used alone or in combination of two or more. can be done. Of these, adipic acid and sebacic acid are particularly preferred from the standpoint of availability.

The copolymerization amount of the alicyclic dicarboxylic acid is preferably 50 mol% or less, more preferably 40 mol% or less, still more preferably 30 mol% or less, when the total amount of the carboxylic acid components is 100 mol%. It is particularly preferably 20 mol % or less, most preferably 10 mol % or less, and may even be 0 mol %. If the amount is too large, it may not be possible to obtain a polyester resin having excellent moist heat resistance. Specific examples of the alicyclic dicarboxylic acid are not particularly limited, but 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid. Acids, dimer acids and the like can be mentioned, and these can be used alone or in combination of two or more. Of these, 1,4-cyclohexanedicarboxylic acid is particularly preferred from the standpoint of availability.

For the amorphous polyester resin (A), it is preferable to use a polyhydric carboxylic anhydride for the purpose of imparting an acid value and branching. Trivalent or higher polyvalent carboxylic anhydrides are more preferred. By imparting an acid value or branching, it can be expected that the reactivity with the polyisocyanate (C) is improved and the adhesiveness to the substrate film is improved. Polyvalent carboxylic anhydrides are not particularly limited, but aromatic anhydrides such as phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, ethylene glycol bis(anhydrotrimellitate), and glycerol trisunhydrotrimellitate. Polyvalent carboxylic acids; fumaric anhydride, maleic anhydride, succinic anhydride, itaconic anhydride, dodecenyl succinic anhydride and other aliphatic polyvalent carboxylic anhydrides; hexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride and the like Alicyclic polyhydric carboxylic anhydrides can be mentioned. These can be used individually or in combination of 2 or more types.

Among the polyhydric carboxylic anhydrides, aromatic polyhydric carboxylic anhydrides are preferred because they have a higher acid value and a higher branching effect than aliphatic polyhydric carboxylic anhydrides and alicyclic polyhydric carboxylic anhydrides. Of these, trimellitic anhydride, ethylene glycol bis(anhydrotrimellitate), and glycerol tris-anhydrotrimellitate are preferred, and trimellitic anhydride is more preferred from the viewpoint of availability.

The method for imparting branching is not particularly limited, but a trifunctional or higher polyhydric carboxylic anhydride is used as a copolymerization component of the amorphous polyester resin (A), and other polyhydric carboxylic acids and polyhydric alcohols are dehydrated and esterified. There is a method of polymerizing through steps. The copolymerization amount of the polycarboxylic anhydride is preferably 0.1 mol% or more, more preferably 0, when the total amount of the carboxylic acid components in the amorphous polyester resin (A) is 100 mol%. .5 mol % or more. If the amount is too small, imparting of branches may be insufficient. Also, it is preferably 5 mol % or less, more preferably 2 mol % or less, and even more preferably 1 mol % or less. If it is too large, the mechanical properties of the thin film may deteriorate, and gelation may occur during polymerization.

The method for imparting an acid value is not particularly limited, but after polymerizing a polyester resin (prepolymer) with a dicarboxylic acid component and a glycol component, a trifunctional or higher polyhydric carboxylic anhydride is subsequently introduced into the system to obtain an acid value. A method of giving The copolymerization amount of the polycarboxylic anhydride is preferably 0.1 mol% or more, more preferably 0.5 mol, with respect to 100 mol% of the total amount of carboxylic acid components in the polyester resin (prepolymer). % or more. If the amount is too small, the acid value may become insufficient. Also, it is preferably 5 mol % or less, more preferably 2 mol % or less, and even more preferably 1 mol % or less. If it is too large, the mechanical properties of the thin film may deteriorate, and gelation may occur during polymerization.

The acid value of the amorphous polyester resin (A) may be 5 equivalents/10 ⁶ g or more, preferably 10 equivalents/10 ⁶ g or more, and more preferably 15 equivalents/10 ⁶ g or more. preferable. If the amount is too small, the reactivity with the polyisocyanate (C) is lowered, and the adhesiveness may be lowered. On the other hand, it must be 400 equivalents/10 ⁶ g or less, preferably 200 equivalents/10 ⁶ g or less, more preferably 150 equivalents/10 ⁶ g or less, and 130 equivalents/10 ⁶ g or less. More preferably: If it is too much, hydrolysis will easily occur.

The amorphous polyester resin (A) preferably has two or more carboxyl groups at the terminals of the resin. By having two or more carboxyl groups at the terminal of the amorphous polyester resin (A), the reactivity with the polyisocyanate (C) can be improved compared to the case where there is one carboxyl group, resulting in excellent adhesion. You can express your sexuality.

The polyhydric alcohol component constituting the amorphous polyester resin (A) used in the present invention is not particularly limited, but may include aliphatic glycols, aromatic glycols or alicyclic glycols, and particularly aliphatic glycols. is preferred.

The aliphatic glycol may be either linear aliphatic glycol or branched aliphatic glycol. Although there are no particular restrictions on the aliphatic glycol, glycols having 2 to 12 carbon atoms are preferred. More preferred aliphatic glycols have 3 or more carbon atoms. It preferably has 9 or less carbon atoms, more preferably 8 or less carbon atoms, still more preferably 7 or less carbon atoms, and particularly preferably 6 or less carbon atoms. The copolymerization amount of the aliphatic glycol is preferably 40 mol% or more, more preferably 50 mol% or more, still more preferably 60 mol% or more, when the total amount of the polyhydric alcohol component is 100 mol%. , Still more preferably 70 mol % or more, particularly preferably 80 mol % or more, most preferably 90 mol % or more, and may be 100 mol %. If the amount is too small, the adhesion to polyethylene terephthalate film (hereinafter also referred to as PET film) may decrease.

Specific examples of aliphatic glycols include, but are not limited to, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1 , 3-propanediol, neopentyl glycol, methylpentanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol, etc., and these may be used alone or in combination of two or more. can be used. Of these, ethylene glycol, neopentyl glycol, 1,4-butanediol, and 2-methyl-1,3-propanediol are particularly preferred.

Examples of the alicyclic glycol include, but are not particularly limited to, cyclohexanediol, cyclohexanedimethanol, hydrogenated xylylene glycol, and the like. Examples of aromatic glycols include, but are not particularly limited to, xylylene glycol.

The glass transition temperature (hereinafter also referred to as Tg) of the amorphous polyester resin (A) must be 20°C or lower. The glass transition temperature is preferably 14°C or lower, more preferably 13°C or lower, and even more preferably 12°C or lower. If the glass transition temperature is too high, the adhesion may deteriorate. Although the lower limit is not particularly limited, it is preferably -10°C or higher, more preferably -5°C or higher.

The glass transition temperature in the present invention is measured by a differential scanning calorimeter (DSC-200, manufactured by SII). Specifically, about 5 mg of a sample (specimen) is placed in an aluminum presser lid type container, sealed, 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 in the process, the temperature at the intersection of the baseline before the endothermic peak and the tangent line toward the endothermic peak is defined as the glass transition temperature (Tg, unit: °C).

The number average molecular weight of the amorphous polyester resin (A) is required to be 5,000 or more, preferably 6,000 or more, more preferably 7,000 or more, further preferably 8,000 or more, further preferably 10,000. It is particularly preferable that it is above. Further, it must be 40,000 or less, preferably 35,000 or less, more preferably 30,000 or less, and particularly preferably 25,000 or less. If the number average molecular weight is lower than 5,000, the mechanical properties as an adhesive are insufficient, and sufficient adhesion to substrates such as polyethylene terephthalate film (hereinafter also referred to as PET film), workability, and resistance to moist heat are obtained. sometimes not. If the number-average molecular weight is higher than 40,000, when the adhesive is dissolved in a solvent and used, the viscosity of the solution becomes too high, which may cause problems such as impossibility of practical use.

The polyester resin (A) used in the present invention is an amorphous polyester resin. By being amorphous, it can be stably dissolved in various organic solvents as compared with crystalline. In addition, it is advantageous in that the polyester resin does not crystallize after the adhesive composition is applied to the substrate, and the adhesive strength does not decrease due to volumetric shrinkage. Amorphous in the present invention means that the temperature is raised from −100° C. to 300° C. at a rate of 20° C./min using a differential scanning calorimeter (DSC), and then the temperature is lowered to −100° C. at a rate of 50° C./min. Then, the temperature is raised from -100°C to 300°C at a rate of 20°C/min. It refers to those that do not show melting peaks in either of the two heating processes. Conversely, crystalline refers to a substance that exhibits a distinct melting peak during either heating process.

<Amorphous polyurethane resin (B)>
The amorphous polyurethane resin (B) used in the present invention preferably comprises a diol component and a diisocyanate component as copolymer components. Further, if necessary, for example, a diamine component or the like may be copolymerized without any problem. As for the diol component, it is desirable to use a polyester polyol as a main component (50% by mass or more). Acrylic polyol, polyether polyol, or the like can also be used as a main component.

As the polyester polyol, the amorphous polyester resin (A) can be used. Examples of the acid component of the polyester polyol include the aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids exemplified for the amorphous polyester resin (A). Among them, it is preferable to use an aromatic dicarboxylic acid, and terephthalic acid and/or isophthalic acid are more preferable.

The copolymerization amount of the aromatic dicarboxylic acid is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more when the total amount of the carboxylic acid components is 100 mol%. is particularly preferably 95 mol % or more, and may be 100 mol %. If the content is too small, the moist heat resistance may deteriorate.

Examples of the glycol component of the polyester polyol include the aliphatic glycols, aromatic glycols and alicyclic glycols exemplified for the amorphous polyester resin (A). Among them, it is preferable to use aliphatic glycol, and ethylene glycol and/or neopentyl glycol are more preferable.

The copolymerization amount of the aliphatic glycol is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more when the total amount of the polyhydric alcohol component is 100 mol%. is particularly preferably 95 mol % or more, and may be 100 mol %.

The diol component may optionally contain a low molecular weight component other than the polyester polyol. For example, diol compounds include 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 2-methyl-1,3-propanediol, 2,2-dimethyl -1,3-propanediol (neopentyl glycol), 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,2-dimethyl-3-hydroxypropyl-2′,2′-dimethyl-3-hydroxypropanoate, 2-n-butyl-2-ethyl-1,3-propanediol, 3-ethyl-1,5-pentane Diol, 3-propyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 3-octyl-1,5-pentanediol, 3-phenyl-1,5-pentanediol, 2, 5-dimethyl-3-sodium sulfo-2,5-hexanediol and the like. 1,2-propanediamine, 1,5-pentamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,2-diaminocyclobutane, 1,2-diaminocyclopentane, 1,2-diaminocyclo Diamine compounds such as heptane can also be used. One or more of these low molecular weight components can be used. Among them, neopentyl glycol is preferred.

As a diol component, the content of polyester polyol is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 70% by mass or more. If the amount is too small, the concentration of urethane groups will increase, resulting in increased cohesive strength and poor adhesion to the substrate. Also, it is preferably 99% by mass or less, more preferably 98% by mass or less. If it is too large, the urethane group concentration becomes low, and the cohesive force is lowered, which may lower the adhesive strength.

When the amorphous polyester resin (A) is used as the diol component, it is preferably not acid-added with a polyhydric carboxylic anhydride. If the resin is acid-added, the terminal end of the resin will have a carboxylic acid group, which may lower the reactivity with the diisocyanate component.

The diisocyanate component used in the amorphous polyurethane resin (B) is not particularly limited, and includes an aromatic diisocyanate component, an aliphatic diisocyanate component and an alicyclic diisocyanate component. Examples of aromatic diisocyanate components include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-phenylene diisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, and 3,3'-dimethoxy-4,4'-biphenylene diisocyanate. , 1,5-naphthalene diisocyanate, 2,6-naphthalene diisocyanate, 4,4′-diisocyanate diphenyl ether, 1,5-xylylene diisocyanate, or o-tolidine diisocyanate. Examples of aliphatic diisocyanate components include ethylene diisocyanate, propylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, and the like. Alicyclic diisocyanates include 1,3-diisocyanatomethylcyclohexane, 1,4-diisocyanatomethylcyclohexane, isophorone diisocyanate and the like. One or more of these can be used. Among them, an aromatic diisocyanate component is preferred, and diphenylmethane diisocyanate is more preferred.

The number average molecular weight of the amorphous polyurethane resin (B) is required to be 5000 or more, preferably 6000 or more, more preferably 7000 or more, further preferably 8000 or more, 10,000 or more is particularly preferable. Moreover, it must be 60,000 or less, preferably 50,000 or less. If the number-average molecular weight is lower than 5,000, the mechanical properties as an adhesive are insufficient, and sufficient adhesion to substrates such as PET films, workability, and resistance to moist heat may not be obtained. If the number-average molecular weight is higher than 60,000, when the adhesive is dissolved in a solvent and used, the viscosity of the solution becomes too high, which may cause problems such as impossibility of practical use.

The glass transition temperature of the amorphous polyurethane resin (B) must be 50°C or higher. The glass transition temperature is more preferably 60°C or higher, and more preferably 70°C or higher. If the glass transition temperature is too low, blocking may occur. Also, it is preferably 150° C. or lower, more preferably 120° C. or lower, and still more preferably 100° C. or lower. If the glass transition temperature is too high, it may become insoluble in organic solvents.

The polyurethane resin (B) used in the present invention is an amorphous polyurethane resin. By being amorphous, it can be stably dissolved in various organic solvents as compared with crystalline. Further, it is advantageous in that the polyurethane resin does not crystallize after the adhesive composition is applied to the substrate, and the adhesive strength does not decrease due to volumetric shrinkage. Amorphous in the present invention means that the temperature is raised from −100° C. to 300° C. at a rate of 20° C./min using a differential scanning calorimeter (DSC), and then the temperature is lowered to −100° C. at a rate of 50° C./min. Then, the temperature is raised from -100°C to 300°C at a rate of 20°C/min. It refers to those that do not show melting peaks in either of the two heating processes. Conversely, crystalline refers to a substance that exhibits a distinct melting peak during either heating process.

The amorphous polyurethane resin (B) used in the present invention may have an acid value. Examples of methods for introducing carboxyl groups into the amorphous polyurethane resin (B) used in the present invention include a method of synthesizing an amorphous polyurethane resin using a polyester polyol having an acid-modified terminal, and a method of synthesizing an amorphous polyurethane resin using dimethylolpropionic acid. , dimethylolbutanoic acid, etc. as a chain extender to synthesize an amorphous polyurethane resin. Of these, the latter is preferred in order to adjust the molecular weight to an appropriate level during the polymerization of the amorphous polyurethane resin.

The content of the amorphous polyurethane resin (B) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 100 parts by mass of the amorphous polyester resin (A). is 15 parts by mass or more. Too little may cause blocking. Also, it is preferably 70 parts by mass or less, more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less. If it is too large, the adhesiveness may be lowered.

<Polyisocyanate (C)>
The polyisocyanate (C) used in the present invention is not particularly limited as long as it has two or more isocyanate groups in the molecule, but from the viewpoint of weather resistance, aliphatic polyisocyanates and alicyclic polyisocyanates are preferred. Aliphatic diisocyanates or alicyclic diisocyanates are more preferred. Specific examples of polyisocyanate (C) are not particularly limited, but aliphatic polyisocyanates include ethylene diisocyanate, propylene diisocyanate, hexamethylene diisocyanate (hereinafter also referred to as HDI), tetramethylene diisocyanate, and the like. . Alicyclic diisocyanates include 1,3-diisocyanatomethylcyclohexane, 1,4-diisocyanatomethylcyclohexane, isophorone diisocyanate, and the like. Furthermore, compounds obtained by polyfunctionalization using these compounds, or compounds obtained by modifying diol compounds using the isocyanates described above may be used. Aromatic diisocyanates can also be used. Aromatic diisocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-phenylene diisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 2,6-naphthalene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 4,4'-diisocyanatodiphenyl ether, or 1,5-xylylene diisocyanate. These can be used individually or in combination of 2 or more types. Preferred examples of the aliphatic polyisocyanate compound include hexamethylene diisocyanate, and the preferred alicyclic polyisocyanate compound includes isophorone diisocyanate.

Polyisocyanate (C) is preferably 0.5 parts by mass or more with respect to 100 parts by mass of polyester resin (A). It is more preferably 1 part by mass or more, still more preferably 1.5 parts by mass or more, and particularly preferably 2 parts by mass or more. Also, it is preferably 20 parts by mass or less, more preferably 19 parts by mass or less, still more preferably 18 parts by mass or less, particularly preferably 17 parts by mass or less, and most preferably 16 parts by mass or less. be. If the amount is too small, sufficient reaction with the amorphous polyester resin (A) may not occur, resulting in a decrease in solvent resistance. If it is too large, the adhesion to the amorphous polyurethane resin (B) may deteriorate.

<Adhesive composition>
The adhesive composition of the present invention is a composition containing the amorphous polyester resin (A), the amorphous polyurethane resin (B) and the polyisocyanate (C). Any widely used additive can be added to the adhesive composition as long as it does not impair the features of the present invention. Additives are not particularly limited, and include, for example, known additives such as ultraviolet absorbers, antioxidants, silane coupling agents, plasticizers, and various adhesive resin components. It can be contained in combination of two or more. Further, a polyester resin different from the amorphous polyester (A) or a polyurethane resin different from the amorphous polyurethane resin (B) may be blended as long as the effects of the present invention are not impaired. Furthermore, a polyolefin resin, a polyimide resin, a polyamide resin, a polyamideimide resin, or the like may be blended.

Curing catalysts may also be used to control reactivity. Although the catalyst is not particularly limited, a polyisocyanate curing catalyst is preferable, and a tin-based or amine-based polyisocyanate curing catalyst is more preferable. Specific examples include, but are not limited to, tin such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin bismaleic acid monobutyl ester, dioctyltin bismaleic acid monobutyl ester, and tetrabutyldiacetoxydistannoxane. system catalyst; tributylamine, triethylenediamine, N'-methyl-N-(2-dimethylaminoethyl)piperazine, 1,8-diazabicyclo(5,4,0)-7-undecene, 1,5-diazabicyclo(4, Amine-based catalysts such as 3,0)-nonene-5,6-dibutylamino-1,8-diazabicyclo(5,4,0)-7-undecene, 1,2-dimethylimidazole can be used. Especially when combined with free polyisocyanate, it is preferable to form a salt of these tertiary amine compounds with phenol or the like.

The adhesive composition of the present invention can also be made into a varnish by containing an organic solvent. The organic solvent is not particularly limited as long as it dissolves the amorphous polyester resin (A), the amorphous polyurethane resin (B) and the polyisocyanate (C). Specifically, for example, aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as hexane, heptane, octane and decane; and alicyclic hydrocarbons such as cyclohexane, cyclohexene, methylcyclohexane and ethylcyclohexane. Aprotic polar solvents such as hydrogen, N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), methanol, ethanol , isopropyl alcohol, butanol, pentanol, hexanol, propanediol, phenol and other alcohol solvents; acetone, methyl isobutyl ketone, methyl ethyl ketone pentanone, hexanone, cyclohexanone, isophorone, acetophenone and other ketone solvents; methyl acetate, ethyl acetate; Ester-based solvents such as butyl acetate, methyl propionate, and butyl formate can be used, and these can be used singly or in combination of two or more. In particular, from the viewpoint of solubility of the resin, it is preferable to partially contain an aprotic polar solvent. By containing an aprotic polar solvent, the resins are easily mixed with the solvent, and the compatibility is improved, so that the coating film is less likely to be streaked. N,N-dimethylformamide (DMF) is particularly preferred.

The amount of the organic solvent is preferably 50 parts by mass or more, more preferably 80 parts by mass or more, and still more preferably 100 parts by mass or more based on 100 parts by mass of the amorphous polyester resin (A). If the amount is too small, it may become difficult to apply to the substrate. Also, it is preferably 1000 parts by mass or less, more preferably 900 parts by mass or less, and even more preferably 800 parts by mass or less. If it is too large, it may be disadvantageous in terms of manufacturing cost and transportation cost. In addition, it is preferable that a part of the organic solvent contains an aprotic polar solvent, and it is preferably 10 parts by mass or more, more preferably 15 parts by mass with respect to 100 parts by mass of the amorphous polyester resin (A). Department or above. Also, it is preferably 100 parts by mass or less, more preferably 70 parts by mass or less.

<Adhesive layer>
An adhesive layer can be produced using the adhesive composition according to the present invention. The adhesive layer of the present invention refers to a layer of the adhesive composition after the adhesive composition has been applied to a substrate, dried, and cured by aging or the like. The thickness of the adhesive layer is preferably 4 μm or more, more preferably 5 μm or more. If the thickness is too thin, the effect as an adhesive may not be exhibited. Also, it is preferably 30 μm or less, more preferably 25 μm or less.

<Laminate>
The laminate of the present invention is a two-layer laminate (base material 1/adhesive layer) of the adhesive layer and the substrate 1, or a three-layer laminate in which the substrate 2 is attached to the surface of the adhesive layer. body (base material 1/adhesive layer/base material 2), and a laminate obtained by bonding a two-layer laminate to a three-layer laminate (base material 1/adhesive layer/base material 2/adhesive layer/ Refers to the base material 3).

Substrate 1, substrate 2 and substrate 3 that can be used in the present invention include, but are not limited to, metal, plastic, wood, cloth, or paper. Examples of the metal material include, but are not particularly limited to, various metals such as aluminum, SUS, copper, iron, and zinc, and their alloys, metal plates such as plated products, metal foils, vapor deposition layers, and the like. Examples of plastics include, but are not particularly limited to, plastic sheets or plastic films such as polyvinyl chloride, polyester, polyolefin, polyamide, poval, or polyurethane. Examples of the cloth include, but are not limited to, cotton, silk, hemp, synthetic fibers such as polyester, and the like. Examples of papers include, but are not limited to, high-quality paper, kraft paper, roll paper, glassine paper, and the like. The substrates 1, 2 and 3 may be of the same type or may be of different types. Moreover, you may laminate|stack the several base material chosen from these.

The adhesive composition of the present invention is particularly suitable for polishing pad applications. For polishing pad applications, the substrate 1 is preferably a plastic film, more preferably a polyester film. A polishing pad is produced by applying an adhesive composition to a polyester film, drying it, and curing it by aging or the like to produce a laminate. Next, a polyurethane prepolymer solution is applied to the surface of the adhesive layer of the laminate, followed by wet coagulation and drying (wet film formation) to form a polishing pad (polyester film) having a porous urethane polishing layer on the polyester film. /adhesive layer/porous urethane polishing layer) can be made.

Examples are given below in order to describe the present invention in more detail, but the present invention is not limited to the examples. In the examples, "parts" means "mass parts".

<Production example (a-1) of polyester resin (A)>
49.8 parts of terephthalic acid, 49.8 parts of isophthalic acid, 58.4 parts of adipic acid, 35.4 parts of ethylene glycol and neopentyl glycol were placed in a reaction vessel equipped with a thermometer, stirrer, reflux condenser and distillation tube. 69.3 parts, 60.0 parts of 1,4-butanediol, and tetra-n-butyl titanate (hereinafter sometimes abbreviated as TBT) as a catalyst were charged in an amount of 0.03 mol% based on the total acid component, and 160 C. to 240.degree. C. over 4 hours while the transesterification reaction was carried out. Then, the pressure in the system was gradually reduced to 5 mmHg over 20 minutes, and polycondensation reaction was carried out at 260° C. for 90 minutes under a vacuum of 0.3 mmHg or less. The mixture was cooled to 220° C. under a nitrogen stream, 2 parts of trimellitic anhydride was added, and the mixture was reacted for 30 minutes to obtain a polyester resin (a-1). Table 1 shows the results of the obtained polyester resin (a-1).

<Production Examples of Polyester Resins (a-2) to (a-11)>
Polyester resins (a-2) to (a-11) were produced according to the production example of polyester resin (a-1), except that the types and blending ratios of the raw materials were changed. Table 1 shows the results. The resin with a number average molecular weight of 50,000 could not be produced because it gelled during production.

1. Composition of Polyester Resin (A) The composition and composition ratio of the polyester resin (A) were determined by ¹ H-NMR measurement (proton type nuclear magnetic resonance spectroscopy) at a resonance frequency of 400 MHz. A 1H-NMR apparatus 400-MR manufactured by VARIAN was used as a measurement apparatus, and deuterated chloroform was used as a solvent.

2. Glass transition temperature (Tg)
It was measured with a differential scanning calorimeter (manufactured by SII, DSC-200). As a sample, 5 mg of a sample (polyester resin or polyurethane resin) was placed in an aluminum lid-type container and sealed. First, the sample 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 in 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 (Tg, unit: °C).

3. Acid value (AV)
0.2 g of a sample (polyester resin or polyurethane resin) was precisely weighed, dissolved in 40 ml of chloroform, and titrated with a 0.01-N ethanol solution of potassium hydroxide. Phenolphthalein was used as an indicator. The measured values were converted into equivalents per 10 ⁶ g of the sample, and the unit was equivalents/10 ⁶ g.

4. Number average molecular weight (Mn)
A sample (polyester resin or polyurethane resin) is dissolved or diluted in tetrahydrofuran so that the resin concentration is about 0.5%, filtered through a polytetrafluoroethylene membrane filter with a pore size of 0.5 μm, and used as a measurement sample. and The molecular weight of the measurement sample was measured by gel permeation chromatography using tetrahydrofuran as a mobile phase and a differential refractometer as a detector. The flow rate was 1 mL/min and the column temperature was 30°C. Showa Denko KF-802, 804L, and 806L columns were used. Monodisperse polystyrene was used as a molecular weight standard. However, when the sample for measurement did not dissolve in tetrahydrofuran, N,N-dimethylformamide was used instead of tetrahydrofuran. Low-molecular-weight compounds (oligomers, etc.) having a number average molecular weight of less than 1000 were omitted without being counted.

In Table 1, the copolymerization components of the polyester resin are represented using the following abbreviations.
TPA: terephthalic acid residue IPA: isophthalic acid residue AA: adipic acid residue SA: sebacic acid residue TMA: trimellitic acid residue EG: ethylene glycol residue 2MG: 2-methyl-1,3-propanediol residue Group NPG: neopentyl glycol residue BD: 1,4-butanediol residue

<Synthesis example (b-1) of amorphous polyurethane resin (B)>
Polyester polyol (composition terephthalic acid/isophthalic acid//ethylene glycol/neopentyl glycol = 50/50//50/50 molar ratio, number average molecular weight 2000, glass 220 parts of a transition temperature of 55° C.) and 200 parts of toluene were charged, heated to 80° C., and completely dissolved over 1 hour. After that, 150 parts of methyl ethyl ketone, 8 parts of neopentyl glycol, 3 parts of 1,6-hexanediol and 50 parts of 4,4'-diphenylmethane diisocyanate were charged and stirred at 80°C for 1 hour. After that, 0.1 g of dibutyltin dilaurate was charged, and the mixture was stirred at 80° C. for 10 hours to carry out a urethanization reaction. After completion of the reaction, toluene and methyl ethyl ketone were charged and diluted to obtain the target amorphous polyurethane resin (B) solution having a solid content concentration of 32% by mass. Characteristic values of the amorphous polyurethane resin (B) thus obtained were a number average molecular weight of 26,000, a glass transition temperature of 80° C., and an acid value of 1 equivalent/10 ⁶ g or less.

<Synthesis example (b-2) of amorphous polyurethane resin (B)>
Polyester polyol (composition terephthalic acid/isophthalic acid//ethylene glycol/sebacic acid/neopentyl glycol = 50/45/5//50/50 molar ratio, number 220 parts of a compound having an average molecular weight of 2000 and a glass transition temperature of 55° C. and 200 parts of toluene were charged, heated to 80° C., and completely dissolved over 1 hour. After that, 150 parts of methyl ethyl ketone, 8 parts of neopentyl glycol, 3 parts of 1,6-hexanediol and 50 parts of 4,4'-diphenylmethane diisocyanate were charged and stirred at 80°C for 1 hour. After that, 0.1 g of dibutyltin dilaurate was charged, and the mixture was stirred at 80° C. for 10 hours to carry out a urethanization reaction. After completion of the reaction, toluene and methyl ethyl ketone were charged and diluted to obtain the target amorphous polyurethane resin (B) solution having a solid content concentration of 32% by mass. Characteristic values of the amorphous polyurethane resin (B) thus obtained were a number average molecular weight of 42,000, a glass transition temperature of 60° C., and an acid value of 1 equivalent/106 g or less.

<Example 1>
70 parts of the amorphous polyester resin (a-1), 20 parts of methyl ethyl ketone, and 20 parts of toluene were charged and dissolved in a reactor equipped with a thermometer, a stirrer and a reflux condenser. Then, 125 parts of amorphous polyurethane resin (b-1) solution (30 parts of solid) and 25 parts of DMF were added and dissolved. One part of polyisocyanate (c-1) was added to this solution to obtain an adhesive composition 1. Table 2 shows the results.

<Examples 2 to 11, Comparative Examples 1 to 5>
Adhesive compositions 2 to 16 were produced in the same manner as in Example 1, except that the types and blending ratios of the raw materials were changed.
In Tables 2 and 3, the following polyisocyanates (C) were used.
Polyisocyanate (c-1): HDI isocyanurate "Coronate (registered trademark) HX made by Nippon Polyurethane"
Polyisocyanate (c-2): HDI adduct "Coronate (registered trademark) HL made by Nippon Polyurethane"

5. Evaluation of Coatability The adhesive composition was applied to a PET film having a thickness of 50 μm with an applicator so that the film thickness after drying was 25 μm. It was confirmed whether streaks were generated when the adhesive composition was applied with an applicator.
Evaluation criteria ○: No streak △: Faint streak ×: Streak

6. Blocking Resistance An adhesive composition was applied to a PET film having a thickness of 50 μm so that the film thickness after drying was 25 μm, and dried at about 120° C. for about 1 minute to prepare a test sample. Two test samples were prepared, the adhesive layers were superimposed on each other, and after pressing for 5 minutes at 40° C. and 30 MPa, the presence or absence of blocking was confirmed.
Evaluation criteria ○: No blocking ×: Blocking

7. Solvent Resistance An adhesive composition was applied to a PET film having a thickness of 50 μm so that the film thickness after drying would be 25 μm. After that, it was dried at about 120° C. for about 1 minute to volatilize the solvent. After that, aging was performed at 40° C. for 3 days. A urethane prepolymer solution prepared in advance was applied onto the adhesive layer to prepare a wet film. The cross section was cut and visually checked for peeling. The urethane prepolymer solution is a DMF solution of a urethane prepolymer containing polybutylene adipate diol/diphenylmethane-4,4′-diisocyanate/diethylene glycol as copolymer components.
Evaluation criteria ○: No peeling △: Some peeling ×: All peeling

8. Adhesive Strength An adhesive composition was applied to a PET film having a thickness of 50 μm so that the film thickness after drying was 25 μm. After that, it was dried at about 120° C. for about 1 minute to volatilize the solvent. After that, aging was performed at 40° C. for 3 days. A urethane prepolymer solution prepared in advance was laminated on the adhesive layer by wet film formation so that the film thickness after drying was 25 μm. At this time, a partial peeling allowance was produced. Adhesion strength was then measured. A bond strength of 1 kgf/inch or more is good.

Claims (6)

an amorphous polyester resin (A) having a number average molecular weight of 5,000 to 40,000, a glass transition temperature of 20° C. or less, and an acid value of 5 to 400 equivalents/10 ⁶ g; an adhesive composition comprising an amorphous polyurethane resin (B) having a temperature of 50° C. or higher, and a polyisocyanate (C). 2. The adhesive composition according to claim 1, wherein the amorphous polyester resin (A) has two or more carboxyl groups at the end of the resin. The blending ratio of the amorphous polyester resin (A) and the amorphous polyurethane resin (B) is 5 parts by mass or more of the amorphous polyurethane resin (B) to 100 parts by mass of the amorphous polyester resin (A) and 70 3. The adhesive composition according to claim 1 or 2, which is not more than parts by mass. A laminate obtained by laminating an adhesive layer comprising the adhesive composition according to any one of claims 1 to 3 and a plastic film. A laminate obtained by laminating a resin on the surface of the adhesive layer of the laminate according to claim 4 . A polishing pad comprising a polishing layer as a part of the laminate according to claim 5 .