Hot melt adhesive composition

Abstract

To provide a hot-melt adhesive composition capable of maintaining an adhesive state over a long period of time and excellent in adhesion holding force.SOLUTION: The hot melt adhesive composition comprises a petroleum resin (A) having a modified petroleum resin (A1) satisfying the following (a) to (c) and a base polymer (B) having a polar group: (a) 0.1 to 10% by mass of a silicon element in terms of a silicon atom, (b) a weight average molecular weight of 500 to 5,000, and (c) a molecular weight distribution (Mw / Mn) of 1.1 to 3.5 SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hot melt adhesive composition. [Background technology]

[0002] Hot melt adhesives are solvent-free adhesives that are applied to an object by heating and melting them, and then solidify when cooled to develop adhesive properties. This allows for instant and high-speed bonding, and they are used in a wide range of fields.

[0003] For example, Patent Document 1 discloses a moisture-curable urethane hot-melt resin composition that contains a urethane prepolymer obtained by reacting a specific polyol with a polyisocyanate, and that has excellent bubbling resistance and surface smoothness.

[0004] Furthermore, Patent Document 2 discloses a pressure-sensitive adhesive composition that contains a base polymer and a moisture-curable component, and that has a swelling index of 2.5 or less when a pressure-sensitive adhesive layer is formed, in order to maintain adhesive strength even when used in an environment where it comes into contact with moisture.

[0005] Furthermore, Patent Document 3 discloses a curable petroleum resin containing a repeating unit (A) derived from a petroleum resin monomer, a repeating unit (B) derived from a silane monomer, and a repeating unit (C) derived from a C3 to C20 alpha-olefin monomer, and describes a reactive polyolefin adhesive composition that is mixed with a polyolefin base polymer to improve adhesive strength. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-108510 [Patent Document 2] Patent No. 7359570 [Patent Document 3] Patent No. 7108604 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the moisture-curable urethane hot-melt resin composition described in Patent Document 1 has a polyester skeleton in the base polymer, which may be hydrolyzed in a high-temperature, high-humidity environment, making it difficult to maintain an adhesive state for a long period of time. Furthermore, even with the pressure-sensitive adhesive composition described in Patent Document 2 and the reactive polyolefin-based adhesive composition described in Patent Document 3, although the adhesive strength is improved, it is thought to be difficult to maintain the adhesive state for a long period of time in an environment where the adhesive comes into contact with moisture.

[0008] Therefore, an object of the present invention is to provide a hot melt adhesive composition that has excellent adhesive retention and can maintain an adhesive state for a long period of time even in an environment where it comes into contact with moisture. [Means for solving the problem]

[0009] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by providing a hot melt adhesive composition containing a modified petroleum resin having a silane modification amount (silicon element content), an average molecular weight, and a molecular weight distribution within specific ranges, and a base polymer.

[0010] That is, the present invention provides the following: <1> ~ <10> Regarding. <1> A petroleum resin (A) having a modified petroleum resin (A1) that satisfies the following (a) to (c), a base polymer (B); A moisture-curable hot melt adhesive composition comprising: (a) Contains 0.1 to 10 mass% silicon element in terms of silicon atoms (b) Weight average molecular weight of 500 to 5,000 (c) Molecular weight distribution (Mw / Mn) of 1.1 to 3.5 <2> A petroleum resin (A) having a modified petroleum resin (A1) that satisfies the following (a) to (c), a base polymer (B) having a polar group; 1. A hot melt adhesive composition comprising: (a) Contains 0.1 to 10 mass% silicon element in terms of silicon atoms (b) Weight average molecular weight of 500 to 5,000 (c) Molecular weight distribution (Mw / Mn) of 1.1 to 3.5 <3> The modified petroleum resin (A1) contains 0.2 to 8.0 mass% silicon element in terms of silicon atoms. <1> or <2> The hot melt adhesive composition according to claim 1. <4> The petroleum resin (A) consists of the modified petroleum resin (A1) and the unmodified petroleum resin (A2), <1> ~ <3> 10. The hot melt adhesive composition according to claim 9, wherein the adhesive is a hydroxybenzoate. <5> The petroleum resin (A) contains 20% by mass or more and less than 100% by mass of the modified petroleum resin (A1) and more than 0% by mass and 80% by mass or less of the unmodified petroleum resin (A2), <4> The hot melt adhesive composition according to claim 1. <6> The base polymer (B) having a polar group is a base polymer modified with at least one selected from the group consisting of maleic anhydride and an amine. <2> ~ <5> The hot melt adhesive composition according to claim 1. <7> The base polymer (B) has an acid value of 1 to 10 mgCHONa / g. <6> The hot melt adhesive composition according to claim 1. <8> The petroleum resin (A) is contained in an amount of 20% by mass or more and 70% by mass or less. <1> ~ <7> 10. The hot melt adhesive composition according to claim 9, wherein the adhesive is a hydroxybenzoate. <9> Further, a plasticizer (C) is contained, The petroleum resin (A) is contained in an amount of 20% by mass or more and 70% by mass or less, the base polymer (B) is contained in an amount of 10% by mass or more and 30% by mass or less, and the plasticizer (C) is contained in an amount of 10% by mass or more and 30% by mass or less. <1> ~ <7> 10. The hot melt adhesive composition according to claim 9, wherein the adhesive is a hydroxybenzoate. <10> For automotive exterior products, solar panels, building and civil engineering components, or textile and leather products, <1> ~ <9> 10. The hot melt adhesive composition according to claim 9, wherein the adhesive is a hydroxybenzoate. [Effects of the Invention]

[0011] The above invention can provide a hot melt adhesive composition that has excellent adhesive retention and can maintain an adhesive state for a long period of time even in an environment where it comes into contact with moisture. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a hot melt adhesive composition according to one embodiment of the present invention will be described.

[0013] [Hot melt adhesive composition] One embodiment of the hot melt adhesive composition of the present invention is a moisture-curable hot melt adhesive composition comprising a petroleum resin (A) having a specific modified petroleum resin (A1) and a base polymer (B). Another embodiment of the hot melt adhesive composition of the present invention is a hot melt adhesive composition comprising a petroleum resin (A) having a specific modified petroleum resin (A1) and a base polymer (B) having a polar group.

[0014] [Petroleum resin (A)] The petroleum resin (A) is a component that serves as a tackifier in the hot melt adhesive composition. In this specification, the term "petroleum resin" refers to a resin obtained by polymerizing or copolymerizing one or more unsaturated compounds selected from aliphatic olefins and aliphatic diolefins having 4 to 10 carbon atoms, which are obtained as by-products during the production of olefins such as ethylene by thermal decomposition of petroleum such as naphtha, and aromatic compounds having 8 or more carbon atoms and having an olefinically unsaturated bond. Petroleum resins can be broadly classified into, for example, "aliphatic petroleum resins" obtained by polymerizing aliphatic olefins or aliphatic diolefins, "aromatic petroleum resins" obtained by polymerizing aromatic compounds having olefinic unsaturated bonds, and "aliphatic-aromatic copolymer petroleum resins" obtained by copolymerizing aliphatic olefins or aliphatic diolefins with aromatic compounds having olefinic unsaturated bonds.

[0015] Examples of the aliphatic olefins having 4 to 10 carbon atoms include butene, pentene, hexene, heptene, etc. Examples of the aliphatic diolefins having 4 to 10 carbon atoms include butadiene, pentadiene, isoprene, piperylene, cyclopentadiene, dicyclopentadiene, methylpentadiene, etc. Examples of aromatic compounds having 8 or more carbon atoms and an olefinically unsaturated bond include styrene, α-methylstyrene, β-methylstyrene, vinyltoluene, vinylxylene, indene, methylindene, ethylindene, etc. Furthermore, the raw material compounds for this petroleum resin do not all need to be by-products of olefin production by thermal decomposition of petroleum such as naphtha, and chemically synthesized unsaturated compounds may also be used.

[0016] Further, preferred examples of petroleum resins include dicyclopentadiene-based petroleum resins obtained by polymerizing cyclopentadiene or dicyclopentadiene, dicyclopentadiene-styrene-based petroleum resins obtained by copolymerizing these cyclopentadiene or dicyclopentadiene with styrene, C5-based petroleum resins obtained by polymerizing isoprene or piperylene, and C9-based petroleum resins obtained by polymerizing C9 monomers such as indene or vinyltoluene.

[0017] The petroleum resin may also include a hydrogenated petroleum resin. In this specification, "hydrogenated petroleum resin" refers to a petroleum resin obtained by adding hydrogen atoms to the petroleum resin. Hydrogenated petroleum resins include fully hydrogenated petroleum resins in which substantially no unsaturated bonds remain and partially hydrogenated petroleum resins in which unsaturated bonds remain, with fully hydrogenated petroleum resins being preferred. The hydrogenated petroleum resin is preferably a hydrogenated aliphatic-aromatic copolymer petroleum resin. The petroleum resin also includes modified petroleum resins that have been modified by introducing various organic groups.

[0018] <Modified petroleum resin (A1)> In the present invention, the petroleum resin (A) contains a predetermined modified petroleum resin (A1). Specifically, this modified petroleum resin (A1) is a silane-modified petroleum resin obtained by modifying the petroleum resin described above, which satisfies the following (a) to (c): (a) Contains 0.1 to 10 mass% silicon element in terms of silicon atoms (b) Weight average molecular weight of 500 to 5,000 (c) Molecular weight distribution (Mw / Mn) of 1.1 to 3.5

[0019] From the viewpoint of improving compatibility with the base polymer and water resistance, this modified petroleum resin (A1) is preferably a silane-modified hydrogenated petroleum resin, more preferably a silane-modified hydrogenated petroleum resin having an organosilane structure, and particularly preferably a silane-modified hydrogenated petroleum resin in which an alkoxysilyl group is bonded to the main chain of the hydrogenated petroleum resin via a bonding moiety. Here, the phrase "the alkoxysilyl group is bonded to the main chain of the hydrogenated petroleum resin via a bonding portion" means that, for example, a bonding portion is directly bonded to a carbon atom contained in a hydrogenated polymer (hydrogenated petroleum resin) obtained by polymerizing aliphatic olefins, aliphatic diolefins, and an aromatic compound having an olefinically unsaturated bond as described above and adding hydrogen atoms, and further an alkoxysilyl group is bonded to the carbon atom. The alkoxysilyl group is preferably a trialkoxysilyl group having an alkoxy group of 1 to 20 carbon atoms, which may be linear or branched, and more preferably a trialkoxysilyl group having an alkoxy group of 1 to 10 carbon atoms, which may be linear or branched. Specific examples include a trimethoxysilyl group, a triethoxysilyl group, and a tripropoxysilyl group, with a trimethoxysilyl group and a triethoxysilyl group being preferred. The bonding portion may be any organic group having a valence of two or more that can bond to a carbon atom in the main chain of the hydrogenated petroleum resin and to which an alkoxysilyl group can be bonded, and is preferably an alkylene group, more preferably an alkylene group having 2 to 3 carbon atoms.

[0020] (Properties of Modified Petroleum Resin (A1)) This modified petroleum resin (A1) contains 0.1 to 10 mass % silicon element in terms of silicon atom, and the silicon element is preferably derived from an organosilane structure. The silicon element content can be measured by ICP emission spectrometry, specifically by the method described in the examples.

[0021] Here, from the viewpoint of improving compatibility with the base polymer and water resistance, the modified petroleum resin (A1) is preferably a silane-modified petroleum resin with a high silane modification rate (elemental silicon content), and more preferably a silane-modified hydrogenated petroleum resin. The silane modification rate (elemental silicon content) is thought to improve the crosslink density by reacting the silane-modified moiety with the base polymer via water, thereby increasing the hardness of the adhesive and improving the adhesive strength. Specifically, the silicon content is preferably 0.1 to 10 mass%, more preferably 0.2 to 8.0 mass%, even more preferably 0.3 to 7.0 mass%, and even more preferably 0.4 to 4.0 mass%, calculated as silicon atoms.

[0022] The weight average molecular weight (Mw) of the modified petroleum resin (A1) is from 500 to 5,000, preferably from 600 to 3,000, more preferably from 700 to 2,000, and even more preferably from 800 to 1,500. The weight-average molecular weight is an index of fluidity when melted, and the smaller the weight-average molecular weight, the greater the fluidity when melted, resulting in better applicability when applied to a hot-melt adhesive composition. By having the weight-average molecular weight within the above range, the adhesive will maintain heat resistance and have excellent applicability when applied to a hot-melt adhesive composition. Furthermore, by having the weight average molecular weight (Mw) within the above range, compatibility with the base polymer is improved and adhesive strength is improved, resulting in good adhesive retention over a long period of time. The weight average molecular weight can be measured specifically by the method described in the Examples.

[0023] The molecular weight distribution (weight average molecular weight / number average molecular weight, Mw / Mn) of the modified petroleum resin (A1) is 1.1 to 3.5, preferably 1.3 to 3.0, more preferably 1.5 to 3.0, and even more preferably 2.0 to 2.5. The molecular weight distribution indicates the degree of dispersion of molecular weights, and becomes broad when there are extremely many low molecular weight components or high molecular weight components. The molecular weight distribution can be measured specifically by the method described in the Examples. When the molecular weight distribution is within the above range, the composition has low odor and excellent coatability. Furthermore, a broader molecular weight distribution improves compatibility with the base polymer and improves adhesive strength, resulting in good adhesive retention over a long period of time. Since the high molecular weight region contributes to retention power and the low molecular weight region contributes to low temperature properties, a wider molecular weight distribution is recognized as a well-balanced hydrogenated petroleum resin.

[0024] The number average molecular weight (Mn) of the modified petroleum resin (A1) is preferably from 100 to 4,500, more preferably from 250 to 2,500, and even more preferably from 300 to 1,500.

[0025] Modified petroleum resin (A1) is 1 The integral ratio of aromatic hydrogen in H-NMR measurement [integral value of peak in the 6.5 to 7.5 ppm region / (sum of integral value of peak in the 0 to 3.0 ppm region and integral value of peak in the 6.5 to 7.5 ppm region)] is preferably 0 to 15%, more preferably 0 to 10%, and even more preferably 0 to 5%. 1The integral ratio of aromatic hydrogen in H-NMR measurement can be specifically measured by the method described in the Examples. 1 The integral ratio of aromatic hydrogen in H-NMR measurement is a value indicating the ratio of aromatic moieties in the modified petroleum resin of the present invention, 1 When the integrated ratio of aromatic hydrogen in H-NMR measurement is within the above range, the composition has low odor and excellent colorlessness.

[0026] The softening point of the modified petroleum resin (A1) is preferably from 60 to 150°C, more preferably from 80 to 140°C, and even more preferably from 90 to 130°C. The softening point can be measured by the ring and ball method, specifically by the method described in the examples. By having a softening point within the above range, when used in a hot melt adhesive composition, an excellent balance between heat resistance and low temperature applicability is achieved. The modified petroleum resin (A1) preferably has a volatile content of 1.0 mass % or less when heated at 150° C. for 20 minutes.

[0027] The color depth of the modified petroleum resin (A1) when melted is, on the Gardner color scale, preferably 1 to 3, more preferably 1 to 2. When the color depth is within this range, the resin has excellent colorlessness, and when used as a component of an adhesive, the appearance of the bonded product is improved.

[0028] (Method for producing modified petroleum resin (A1)) The method for producing the modified petroleum resin (A1) is not particularly limited, but from the viewpoint of efficiently introducing silane into the resin, the following method is preferred. The method for producing the modified petroleum resin (A1) is preferably a method in which a petroleum resin is reacted with a compound having a carbon-carbon double bond and an alkoxysilyl group in the presence of a compound that generates radicals.

[0029] The petroleum resin used as a raw material in the above-mentioned production method is an unmodified one of the above-mentioned "petroleum resins", and is preferably a hydrogenated petroleum resin in which hydrogen atoms are added to a petroleum resin.

[0030] The compound having a carbon-carbon double bond and an alkoxysilyl group used in the production method is a compound in which one or more organic groups having a carbon-carbon double bond and one or more alkoxy groups are bonded to a silicon atom. Examples of the organic group having a carbon-carbon double bond include a vinyl group, an allyl group, a butenyl group, a cyclohexenyl group, a cyclopentadienyl group, a (meth)acryloxy group, and a (meth)acryloxypropyl group, and the vinyl group, methacryloxy group, and acryloxy group are preferred. Examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, and a butoxy group. The number of alkoxy groups bonded to the silicon atom is preferably one or more, more preferably two or more, and even more preferably three. Specific examples of the compound having a carbon-carbon double bond and an alkoxysilyl group include vinyltriethoxysilane, vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, and methacryloxypropyltriethoxysilane, with vinyltriethoxysilane and vinyltrimethoxysilane being preferred. The amount of the compound having a carbon-carbon double bond and an alkoxysilyl group used in the production method is, in terms of silicon atoms of the compound having a carbon-carbon double bond and an alkoxysilyl group, preferably 0.1 to 10 mass%, more preferably 0.1 to 9.0 mass%, even more preferably 0.2 to 8.0 mass%, and even more preferably 0.3 to 7.0 mass%, relative to the petroleum resin. The amount of the compound having a carbon-carbon double bond and an alkoxysilyl group used is preferably large so that the silane modification rate (silicon content) is high. For example, the low-modification hydrogenated petroleum resin obtained in Production Example 3 described below theoretically has about 0.3 vinylsilane groups attached to one molecule of hydrogenated petroleum resin, and has few reactive sites that react with moisture and contribute to maintaining / improving adhesive strength. However, the highly modified hydrogenated petroleum resin obtained in Production Example 4 theoretically has about one vinylsilane group attached to one molecule of hydrogenated petroleum resin, so that there are many reactive sites and adhesive performance is improved. Furthermore, the more vinylsilane groups attached to one molecule, the more reactive sites there are, which is thought to contribute more to maintaining / improving adhesive strength.

[0031] The radical-generating compound used in the above production method can be a compound generally known as a radical polymerization initiator. The radical-generating compound can be appropriately selected from, for example, various organic peroxides and azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile, and among these, organic peroxides are preferred. Examples of organic peroxides include diacyl peroxides such as dibenzoyl peroxide, di-3,5,5-trimethylhexanoyl peroxide, dilauroyl peroxide, didecanoyl peroxide, and di(2,4-dichlorobenzoyl) peroxide; hydroperoxides such as t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, and 2,5-dimethylhexane-2,5-dihydroperoxide; di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,1-di(t-butylperoxy)cyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, and α,α'-bis(t-butyl Examples of suitable peroxycarbonates include dialkyl peroxides such as di(tert-butylperoxy)diisopropylbenzene; peroxyketals such as 1,1-bis-t-butylperoxy-3,3,5-trimethylcyclohexane and 2,2-bis(t-butylperoxy)butane; alkyl peresters such as 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, n-butyl 4,4-di(t-butylperoxy)valerate, t-butyl peroxyoctoate, t-butyl peroxypivalate, t-butyl peroxyneodecanoate, and t-butyl peroxybenzoate; and peroxycarbonates such as di-2-ethylhexyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, and t-butylperoxyisopropylcarbonate. Among these, dialkyl peroxides are preferred. These may be used alone or in combination of two or more. The amount of the radical-generating compound used is not particularly limited, but is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, based on the petroleum resin.

[0032] As described above, a suitable method for producing the modified petroleum resin (A1) is a method of reacting a petroleum resin with a compound having a carbon-carbon double bond and an alkoxysilyl group in the presence of a compound that generates radicals. There are no limitations on the reaction method as long as the reaction proceeds sufficiently. However, (1) a method of mixing a molten petroleum resin, a compound having a carbon-carbon double bond and an alkoxysilyl group, and a compound that generates radicals, and then generating radicals by heating or the like, to cause the reaction, is preferred, and (2) a method of dissolving a petroleum resin, a compound having a carbon-carbon double bond and an alkoxysilyl group, and a compound that generates radicals in an organic solvent, and then generating radicals by heating or the like, to cause the reaction, is more preferred. (1) A method of mixing a molten petroleum resin, a compound having a carbon-carbon double bond and an alkoxysilyl group, and a compound that generates radicals, and then generating radicals by heating or the like, to cause the reaction, is more preferred.

[0033] In the case of the method (1) above, it is preferable to melt the petroleum resin, mix it with a compound having a carbon-carbon double bond and an alkoxysilyl group, add a compound that generates radicals, and heat the mixture to react the petroleum resin with the carbon-carbon double bond portion of the compound having a carbon-carbon double bond and an alkoxysilyl group, thereby obtaining a modified petroleum resin. In this method, when the melt viscosity of the petroleum resin is low, it is preferable to carry out the reaction while stirring in a conventional reaction apparatus, and when the melt viscosity of the petroleum resin is high, it is preferable to carry out the reaction while melt-kneading using a roll mill, a Banbury mixer, an extruder, or the like. The reaction temperature is preferably 100 to 300°C, more preferably 100 to 200°C.

[0034] In the case of the method (2) above, it is preferable to obtain a modified petroleum resin by dissolving the petroleum resin in an organic solvent, mixing with a compound having a carbon-carbon double bond and an alkoxysilyl group, adding a compound that generates radicals, and heating the mixture to react the petroleum resin with the carbon-carbon double bond portion of the compound having a carbon-carbon double bond and an alkoxysilyl group. Examples of organic solvents that can be used in this method include hydrocarbon solvents such as pentane, hexane, heptane, cyclohexane, toluene, xylene, and decahydronaphthalene, halogenated hydrocarbon solvents such as chlorobenzene, dichlorobenzene, and trichlorobenzene, and liquefied α-olefins. The reaction temperature is preferably from -50 to 300°C, more preferably from 0 to 300°C, further preferably from 100 to 300°C, and even further preferably from 100 to 200°C.

[0035] The content of the petroleum resin (A) in the hot melt adhesive composition is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and even more preferably 50% by mass or more, and is preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less.

[0036] The content of the modified petroleum resin (A1) in the petroleum resin (A) is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, still more preferably 50% by mass or more, still more preferably 60% by mass or more, still more preferably 70% by mass or more, still more preferably 80% by mass or more, and preferably 100% by mass or less.

[0037] In the present invention, the petroleum resin (A) may be a combination of a modified petroleum resin (A1) and an unmodified petroleum resin (A2). The unmodified petroleum resin (A2) refers to a petroleum resin that is not modified among the above-mentioned "petroleum resins," and an unmodified hydrogenated petroleum resin is preferred. When the petroleum resin (A) contains the modified petroleum resin (A1) and the unmodified petroleum resin (A2), the petroleum resin (A) preferably consists of these components (A1) and (A2). In this case, the contents of the modified petroleum resin (A1) and the unmodified petroleum resin (A2) in the petroleum resin (A) may be 20% by mass or more but less than 100% by mass of the modified petroleum resin (A1) and more than 0% by mass but less than 80% by mass of the unmodified petroleum resin (A2), or may be 25% by mass or more but less than 100% by mass of the modified petroleum resin (A1) and more than 0% by mass but less than 75% by mass of the unmodified petroleum resin (A2). It is believed that the combined use of the modified petroleum resin (A1) and the unmodified petroleum resin (A2) can improve compatibility with the base polymer and adhesive performance compared to the use of the modified petroleum resin (A1) alone. In addition, when using these resins in combination, it is preferable to blend a highly modified petroleum resin (A1) having a high silicon element concentration of 0.7 mass% or more with an unmodified petroleum resin (A2). In this case, adhesive performance can be improved more than when a low-modified petroleum resin (A) having a modification degree (silicon element concentration) of less than 0.7 mass% is used alone (see, for example, Examples 3 and 5 described later). Furthermore, although highly modified petroleum resins are more expensive than less modified petroleum resins, it is believed that there are cost benefits to adding a small amount of highly modified petroleum resin and blending it with cheaper unmodified petroleum resin to improve adhesive performance, rather than adding a large amount of less modified petroleum resin.

[0038] [Base polymer (B)] The base polymer (B) is a curing component in the hot melt adhesive composition, and refers to the polymer contained in the largest amount among the polymer components used as components other than the petroleum resin (A). Specific examples of the base polymer include natural rubber, olefin-based elastomers, styrene-based elastomers, and olefin-based plastomers, with olefin-based elastomers and styrene-based elastomers being preferred. The elastomer is not limited by density as long as it has rubber elastic properties, and may be either chemically crosslinked or not. The plastomer is not limited by density as long as it undergoes plastic deformation, and may be chemically crosslinked or non-chemically crosslinked. These may be used alone or in combination of two or more.

[0039] Examples of the olefin elastomer include ethylene olefin polymers, amorphous olefin polymers, propylene elastomers, ethylene-vinyl acetate copolymers, and ethylene-acrylic acid ester copolymers, with propylene elastomers and ethylene olefin polymers being preferred.

[0040] Ethylene-based olefin polymers are olefin polymers whose main structural unit is ethylene units. Specific examples include polyethylene and copolymers of ethylene and an olefin having 3 to 10 carbon atoms. Here, the term "main structural unit" refers to the structural unit that is most abundant among the structural units constituting the polymer. In this specification, a polymer that contains the most ethylene units but has the same amount of other structural units is referred to as an ethylene-based olefin polymer. While there are no particular limitations on the polymer as long as it can be used as the base polymer for the hot melt adhesive composition, from the viewpoint of the adhesiveness of the hot melt adhesive composition, an ethylene-α-olefin copolymer is preferred. Specific examples of α-olefins include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. One or more of these can be used. Among these α-olefins, 1-octene is preferred. From the viewpoint of adhesiveness of the hot melt adhesive composition, an ethylene-1-octene copolymer is more preferable, and an ethylene-1-octene copolymer containing 5 to 50 mass % of structural units derived from 1-octene is even more preferable. From the viewpoint of heat creep resistance, the melting point of the ethylene-based olefin polymer is preferably 60 to 120°C, more preferably 60 to 90°C. The melting point of the ethylene-based olefin polymer can be measured by differential scanning calorimetry. Among the ethylene-based olefin polymers, amorphous ones belong to the category of amorphous olefin polymers described below.

[0041] The amorphous olefin polymer is a homopolymer or copolymer containing one or more selected from the group consisting of linear or branched α-olefins or dienes having 2 to 24 carbon atoms, and includes, but is not limited to, ethylene-propylene copolymer, atactic polypropylene, polybutene, atactic poly-1-butene, polybutadiene, polyisoprene, and amorphous polyalphaolefin. Examples of polybutene include homopolymers or copolymers of isobutene and normal butene, and hydrogenated products thereof. Examples of polybutadienes include homopolymers or copolymers of 1,2-butadiene or 1,4-butadiene, and hydrogenated products thereof, which may have terminal hydroxyl groups. Examples of polyisoprene include homopolymers or copolymers of isoprene and hydrogenated products thereof, which may have terminal hydroxyl groups. Examples of amorphous polyalphaolefins include homopolymers and copolymers of olefins having 2 to 6 carbon atoms.

[0042] The propylene-based elastomer is an elastomer having propylene units as the main constituent unit, and examples thereof include low-crystalline polypropylene.

[0043] The vinyl acetate content of the ethylene-vinyl acetate copolymer is preferably from 5 to 50% by mass, more preferably from 10 to 40% by mass.

[0044] As the styrene elastomer, a styrene block copolymer is preferred. The styrene-based block copolymer is a copolymer in which a styrene-based compound and a conjugated diene compound are block copolymerized, and usually has a styrene-based compound block and a conjugated diene compound block.

[0045] Examples of "styrene-based compounds" include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, and vinylanthracene. Styrene is particularly preferred. These styrene-based compounds can be used alone or in combination. The term "conjugated diene compound" refers to a diolefin compound having at least one pair of conjugated double bonds. Specific examples of the "conjugated diene compound" include 1,3-butadiene, 2-methyl-1,3-butadiene (or isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. 1,3-butadiene and 2-methyl-1,3-butadiene are particularly preferred. These conjugated diene compounds can be used alone or in combination.

[0046] The styrene-based block copolymer may be an unhydrogenated product or a hydrogenated product. Specific examples of "unhydrogenated styrene-based block copolymers" include those in which the blocks based on conjugated diene compounds have not been hydrogenated. Specific examples of "hydrogenated styrene-based block copolymers" include block copolymers in which all or part of the blocks based on conjugated diene compounds have been hydrogenated. The hydrogenation rate of a "hydrogenated styrene block copolymer" can be expressed as the "hydrogenation rate." The "hydrogenation rate" of a "hydrogenated styrene block copolymer" refers to the rate of double bonds that have been hydrogenated and converted to saturated hydrocarbon bonds, based on the total aliphatic double bonds contained in the block based on the conjugated diene compound. This "hydrogenation rate" can be measured using an infrared spectrophotometer, a nuclear magnetic resonance spectrometer, or the like.

[0047] Specific examples of "unhydrogenated styrene block copolymers" include styrene-isoprene-styrene block copolymers (also referred to as "SIS") and styrene-butadiene-styrene block copolymers (also referred to as "SBS"). Specific examples of "hydrogenated styrene block copolymers" include hydrogenated styrene-isoprene-styrene block copolymers (also referred to as "SEPS") and hydrogenated styrene-ethylene-butadiene-styrene block copolymers (also referred to as "SEBS"). The styrene-based block copolymers can be used alone or in combination.

[0048] From the viewpoint of adhesive strength of the hot melt adhesive composition, the proportion of styrene blocks contained in the styrene block copolymer (styrene content) is preferably 5 to 50 mass %, more preferably 10 to 40 mass %.

[0049] In addition, the base polymer (B) can be modified by introducing various organic groups, and a polymer into which a silane-containing group or an isocyanate group that undergoes a condensation reaction with moisture can be used to produce a good moisture-curable (reactive) hot melt adhesive composition.

[0050] Furthermore, from the viewpoint of imparting good adhesive strength over a long period of time, the base polymer (B) is preferably a polymer having a polar group. The polar group can be introduced by modifying the base polymer with a compound such as maleic anhydride or an amine during the production of the base polymer described above. Among these, from the viewpoint of improving the reactivity with the silane groups of the modified petroleum resin (A1) and imparting good adhesive strength over a long period of time, a base polymer modified with at least one selected from the group consisting of maleic anhydride and an amine is preferred, and a base polymer modified with maleic anhydride is more preferred. The amines used for modification include alkylamines, alkenylamines, arylamines, cyclic alkylamines, heterocyclic amines, and the like.

[0051] Furthermore, in order to provide good adhesive retention over a long period of time, the acid value of this base polymer (B) is preferably 1 mg CH3ONa / g or more and 10 mg CH3ONa / g or less, more preferably 2 mg CH3ONa / g or more and 8 mg CH3ONa / g or less, and even more preferably 2 mg CH3ONa / g or more and 5 mg CH3ONa / g or less.

[0052] From the viewpoint of cohesiveness, the content of the base polymer (B) in the hot melt adhesive composition is preferably 8% by mass or more, more preferably 10% by mass or more, even more preferably 13% by mass or more, and is preferably 30% by mass or less, more preferably 27% by mass or less, even more preferably 25% by mass or less. The glass transition temperature of the base polymer is preferably from -20 to 100°C, more preferably from -20 to 60°C.

[0053] [Plasticizer (C)] The hot melt adhesive composition preferably further contains a plasticizer (C). The plasticizer (C) is not particularly limited, but is preferably a known plasticizer used in hot melt adhesive compositions, more preferably oil or wax. In addition, phthalate esters, adipic acid esters, fatty acid esters, glycols, epoxy polymer plasticizers, etc. can also be used as the plasticizer.

[0054] Examples of oils include paraffinic process oil, naphthenic process oil, isoparaffinic oil, and aromatic oil.

[0055] Commercially available paraffinic process oils include "Diana Process Oil PW-32," "Diana Process Oil PW-90," "Diana Process Oil PW-150," "Diana Process Oil PS-32," "Diana Process Oil PS-90," and "Diana Process Oil PS-430" (all trade names, and "Diana" is a registered trademark) manufactured by Idemitsu Kosan Co., Ltd.; "Kaydol (registered trademark) Oil" manufactured by Sonneborn; and "ParaLux (registered trademark) Oil" manufactured by Chevron USA, Inc. (all trade names).

[0056] Commercially available isoparaffin oils include "IP Solvent 1016," "IP Solvent 1620," "IP Solvent 2028," "IP Solvent 2835," and "IP Clean LX" manufactured by Idemitsu Kosan Co., Ltd.; and the "NA Solvent" series manufactured by NOF Corporation (all trade names).

[0057] Examples of waxes include animal waxes, vegetable waxes, carnauba wax, candelilla wax, Japan wax, beeswax, mineral waxes, petroleum wax, paraffin wax, microcrystalline wax, petrolatum, higher fatty acid waxes, higher fatty acid ester waxes, Fischer-Tropsch wax, polypropylene wax, polyethylene wax, and propylene-ethylene copolymer wax.

[0058] When the plasticizer (C) is contained, its content in the hot melt adhesive composition is preferably 10% by mass or more, more preferably 13% by mass or more, even more preferably 15% by mass or more, and is preferably 30% by mass or less, more preferably 27% by mass or less, even more preferably 25% by mass or less, from the viewpoint of improving adhesion and improving coatability.

[0059] [Tackifier] The hot melt adhesive composition may further contain a tackifier other than the (A) petroleum resin. Examples of this tackifier include those that are solid, semi-solid, or liquid at room temperature and are made of rosin derivative resins, polyterpene resins, oil-soluble phenolic resins, etc. Specific examples include natural rosin, modified rosin, hydrogenated rosin, glycerol esters of natural rosin, glycerol esters of modified rosin, pentaerythritol esters of natural rosin, pentaerythritol esters of modified rosin, pentaerythritol esters of hydrogenated rosin, copolymers of natural terpenes, three-dimensional polymers of natural terpenes, hydrogenated derivatives of hydrogenated terpene copolymers, polyterpene resins, and hydrogenated derivatives of phenol-based modified terpene resins. Further examples of the tackifier include unmodified petroleum resins, such as aliphatic petroleum hydrocarbon resins, hydrogenated derivatives of aliphatic petroleum hydrocarbon resins, aromatic petroleum hydrocarbon resins, hydrogenated derivatives of aromatic petroleum hydrocarbon resins, cycloaliphatic petroleum hydrocarbon resins, and hydrogenated derivatives of cycloaliphatic petroleum hydrocarbon resins. The tackifiers may be used alone or in combination of two or more kinds. Of the above tackifiers, hydrogenated products are preferably used in consideration of compatibility with the base polymer.

[0060] Commercially available tackifiers include the following: Examples of tackifiers produced using raw materials obtained during the crude oil and naphtha refining process include "Imarv" (manufactured by Idemitsu Kosan Co., Ltd.), "Alcon" (manufactured by Arakawa Chemical Industries, Ltd.), "Quinton" (manufactured by Zeon Corporation), "T-REZ" (manufactured by ENEOS Corporation), "Escorez", "Oppera" (all manufactured by ExxonMobil Chemical Company), "Eastotac", "Regalite", "Regalrez", "Plastolyn" (all manufactured by Eastman), "Sukorez" (manufactured by Kolon Industries), and "Wingtack" and "Norsolene" (all manufactured by Cray Valley Chemical Industry Co., Ltd.) (all trade names and registered trademarks). Examples of tackifiers produced using essential oils obtained from oranges or the like as raw materials include "Clearon" (manufactured by Yasuhara Chemical Co., Ltd.), "Sylvalite" and "Sylvares" (manufactured by KRATON) (all of which are trade names and registered trademarks). Examples of tackifiers produced using raw materials such as rosin include "Haritack" and "Neotol (registered trademark)" (manufactured by Harima Chemical Co., Ltd.), and "Ester Gum" and "Pensel (registered trademark)" (manufactured by Arakawa Chemical Industries, Ltd.) (all trade names).

[0061] When this tackifier is contained, from the viewpoint of improving adhesiveness, its content in the hot melt adhesive composition is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, even more preferably 20% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, even more preferably 30% by mass or less.

[0062] The softening point of the tackifier is preferably −20° C. or higher, more preferably −15° C. or higher, even more preferably −10° C. or higher, and preferably 180° C. or lower, more preferably 170° C. or lower, even more preferably 160° C. or lower.

[0063] In the hot melt adhesive composition, the total content of the petroleum resin (A), base polymer (B), plasticizer (C), and tackifier is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and preferably 100% by mass or less.

[0064] [Other additives] The hot melt adhesive composition may further contain optional additives such as inorganic fillers, antioxidants, ultraviolet absorbers, light stabilizers, and lubricants, as needed, within the scope of the invention.

[0065] Examples of inorganic fillers include talc, calcium carbonate, barium carbonate, wollastonite, silica, clay, mica, kaolin, titanium oxide, diatomaceous earth, urea resins, styrene beads, starch, barium sulfate, calcium sulfate, magnesium silicate, magnesium carbonate, alumina, and quartz powder.

[0066] Antioxidants include trisnonylphenyl phosphite, distearyl pentaerythritol diphosphite, "ADEKA STAB (registered trademark) 1178" (manufactured by ADEKA Corporation), "Sumilizer (registered trademark) TNP" (manufactured by Sumitomo Chemical Co., Ltd.), "Irgafos (registered trademark) 168" (manufactured by BASF), and "Sandostab (registered trademark) Examples of antioxidants include phosphorus-based antioxidants such as 2,6-di-t-butyl-4-methylphenol, n-octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, Sumilizer (registered trademark) BHT (manufactured by Sumitomo Chemical Co., Ltd.), and Irganox (registered trademark) 1010 (manufactured by BASF), and sulfur-based antioxidants such as dilauryl-3,3'-thiodipropionate, pentaerythritol tetrakis(3-laurylthiopropionate), Sumilizer (registered trademark) TPL (manufactured by Sumitomo Chemical Co., Ltd.), DLTP (Yoshitomi (registered trademark)), DSTP (Yoshitomi (registered trademark)), and DMTP (Yoshitomi (registered trademark)) (all manufactured by Mitsubishi Chemical Corporation), and Antiox (registered trademark) L (manufactured by NOF Corporation).

[0067] [Production method and use of hot melt adhesive composition] The hot melt adhesive composition can be produced by dry blending the petroleum resin (A) and base polymer (B) described above, and, if necessary, a plasticizer (C), a tackifier, and additives, using a Henschel mixer or the like, and melt-kneading the mixture using a single-screw or twin-screw extruder, a plastomill, a Banbury mixer, or the like.

[0068] The hot melt adhesive composition can maintain good adhesion for a long period of time, and is therefore suitable for, for example, the interior and exterior use of transportation equipment such as automobiles, trains, ships, and aircraft, solar panels, building and civil engineering, sanitary materials, packaging, bookbinding, textiles, woodworking, electrical materials, can making, filters, low-pressure molding, shoemaking, and bag making, and can be used both indoors and outdoors. In particular, because it can exhibit good adhesion for a long period of time even under high temperature and high humidity conditions where there is frequent contact with moisture, it is suitable as an adhesive composition for use in automobile exterior products, solar panels, building and civil engineering materials, textile and leather products, shoe products, and the like. [Example]

[0069] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples in any way.

[0070] [Analysis and evaluation of petroleum resins] [1. Silicon concentration] 0.1 g of the unmodified petroleum resin or modified petroleum resin obtained in the examples and comparative examples was heated in an electric furnace at 550°C for 12 hours, and the ash was dissolved in alkali to prepare a measurement solution. ICP emission spectroscopy was then performed (ICP emission spectroscopy analyzer: 720-ES, manufactured by Agilent Technologies, Inc.) to determine the silicon concentration.

[0071] 2. Molecular Weight and Molecular Weight Distribution The average molecular weight was measured by gel permeation chromatography (GPC) using a GPC measuring device (HLC8220, detector: RI, columns: TSK-GEL GHXL-L, G4000HXL, G2000HXL, tetrahydrofuran as eluent, all manufactured by Tosoh Corporation), and the polystyrene-equivalent number average molecular weight (Mn) and weight average molecular weight (Mw) were determined, and the molecular weight distribution (Mw / Mn) was calculated.

[0072] [3. Integral ratio of aromatic hydrogen] Using a nuclear magnetic resonance (NMR) device (JNM-EX400, manufactured by JEOL Ltd.), the solvent was deuterated chloroform, and the number of cycles was 256. 1 H-NMR measurements were performed, and the ratio of the integral of the peak in the 6.5-7.5 ppm region (aromatic hydrogen peak) to the sum of the integrals of the peaks in the 0-3.0 ppm region and the 6.5-7.5 ppm region (integral of the peak in the 6.5-7.5 ppm region / (sum of the integrals of the peaks in the 0-3.0 ppm region and the 6.5-7.5 ppm region)) was calculated. If peaks due to raw material additives (antioxidants, etc.) or solvents (chloroform, etc.) were present in the 0-3.0 ppm and 6.5-7.5 ppm regions, standard samples were similarly measured, and the integrals were subtracted from the above integrals to determine the ratio. However, for the resin of Production Example 2, the same measurements were performed on a silane-modified, untreated hydrogenated petroleum resin, and the above integral ratio was calculated.

[0073] [4. Softening point] Measurement was carried out in accordance with JIS K 6863.

[0074] [5. Volatile content] Gas components were generated using a headspace gas chromatograph (instrument name: Agilent 7697A / Agilent 7890B, manufactured by Agilent Technologies, Inc.), and the amount of components with a retention time of less than 40 minutes when measured under the following conditions was taken as the amount of volatile matter. (Measurement conditions) Sample heat treatment: 150°C, 20 min, Column: BPX5 30 m x 0.32 m id x 1.0 μm, Injection port: 300°C, Temperature program: 50°C to 300°C, 10°C / min, temperature increase

[0075] 6. Testing Adhesion Holding Power of Hot Melt Adhesive Compositions 10 g of the hot melt adhesive composition obtained in each example was dissolved in 7.5 g of toluene and stirred overnight. This solution was applied to a 50 μm thick, 25 mm x 25 mm PET film using a 90 μm coater. After application to the film, it was heated at 100 °C for 5 minutes and then cured at room temperature for one day and night to completely volatilize the toluene and adjust the thickness to 50 μm. The entire surface of the film was bonded to a 2 mm thick, 25 mm x 60 mm stainless steel (SUS) plate to prepare a sample for holding power testing. The obtained samples were exposed in a high-temperature, high-humidity oven at 50°C and 85% RH for three predetermined periods of time, namely, 14 days, 26 days, and 48 days, to obtain aged samples. Each of the obtained aged samples was aged for 24 hours in an atmosphere of 23°C x 50% RH, and then subjected to an adhesive holding strength test under the following measurement conditions. (Measurement conditions) The holding power test was carried out under a load of 1 kg in an atmosphere of 50°C x 50% RH using a holding power tester manufactured by Tester Sangyo Co., Ltd. The time (minutes) from the start of the test until the adhesive surface peeled off was taken as the adhesive holding power.

[0076] [Petroleum resin manufacturing] Production Example 1 (Production of Unmodified Petroleum Resin) 180 g of xylene was placed in a 1-liter autoclave and heated to 260°C. Next, a mixture of 100 g of dicyclopentadiene and 100 g of styrene was placed in over 3 hours. This temperature was maintained for an additional 75 minutes to carry out a polymerization reaction, yielding a polymer mixture. Thereafter, xylene was recovered from the resulting polymer mixture, and the mixture was then maintained at 20 mmHg for 2 hours to distill off low boiling point substances, thereby obtaining an unmodified petroleum resin.

[0077] Production Example 2 (Production of Unmodified Hydrogenated Petroleum Resin) 180 g of the unmodified petroleum resin obtained in Production Example 1, 180 g of ethylcyclohexane, and 4 g of a nickel-based catalyst (N110 series) manufactured by JGC Catalysts and Chemicals Co., Ltd. were placed in a 1-liter autoclave. Hydrogen was added to the autoclave to a pressure of 5 MPa, and the autoclave was heated from room temperature to 230°C. A hydrogenation reaction was then carried out for 8 hours while maintaining the hydrogen pressure at 5 MPa, yielding an unmodified hydrogenated petroleum resin. The analysis and evaluation results of the obtained unmodified hydrogenated petroleum resin are shown in Table 1.

[0078] Production Example 3 (Production of Low-Modified Hydrogenated Petroleum Resin) 100 g of the unmodified hydrogenated petroleum resin obtained in Production Example 2 was placed in a 500 mL separable flask equipped with a nitrogen inlet tube and a stirring blade, and heated to 160° C. in an oil bath under a nitrogen stream. Once the hydrogenated petroleum resin had dissolved, 3.2 g of vinyltrimethoxysilane (trade name "KBM-1003", manufactured by Shin-Etsu Chemical Co., Ltd.) was added with stirring, and the mixture was stirred until homogenized. Next, 0.7 g of organic peroxide (2,5-dimethyl-2,5-di(t-butylperoxy)hexane (trade name "Perhexa (registered trademark) 25B", manufactured by NOF Corporation) was added. After the addition, the mixture was stirred at an internal temperature (reactant mixing temperature) of 160°C for 1 hour to allow the reaction to occur. After the reaction was completed, the contents of the separable flask were transferred to a stainless steel tray and cooled to solidify at room temperature to obtain 92 g of a low-modified hydrogenated petroleum resin. The analysis and evaluation results of the obtained modified hydrogenated petroleum resin 1 are shown in Table 1.

[0079] Production Example 4 (Production of highly modified hydrogenated petroleum resin) 92 g of a highly modified hydrogenated petroleum resin was obtained in the same manner as in Production Example 3, except that the amount of vinyltrimethoxysilane added was changed to 10 g in Production Example 3. The analysis and evaluation results of the obtained modified hydrogenated petroleum resin 2 are shown in Table 1.

[0080] [Table 1]

[0081] [Production of Hot Melt Adhesive Composition] Example 1 Hot melt adhesive composition 1 was produced by dissolving 60 parts by mass of the modified hydrogenated petroleum resin 2 obtained in Production Example 4 as the petroleum resin, 20 parts by mass of a hydrogenated styrene-based thermoplastic elastomer (SEBS) modified with maleic anhydride and having polar groups (product name "Tuftec (registered trademark) M1911: acid value 2 mgCHONa / g", manufactured by Asahi Kasei Corporation: base polymer 1) as the base polymer, and 20 parts by mass of process oil (product name "Diana Process Oil PS-32", manufactured by Idemitsu Kosan Co., Ltd.) as the plasticizer in 150 parts by mass of toluene and stirring overnight.

[0082] Example 2 Hot melt adhesive composition 2 was produced in the same manner as in Example 1, except that in Example 1, base polymer 1 was replaced with 20 parts by mass of a hydrogenated styrene-based thermoplastic elastomer (SEBS) having no polar groups (product name "Tuftec (registered trademark) H1041", manufactured by Asahi Kasei Corporation: base polymer 2).

[0083] Example 3 A hot melt adhesive composition 3 was produced in the same manner as in Example 1, except that 60 parts by mass of the modified hydrogenated petroleum resin 1 obtained in Production Example 3 was used instead of the modified hydrogenated petroleum resin 2 in Example 1.

[0084] Example 4 In Example 3, a hot melt adhesive composition 4 was produced in the same manner as in Example 3, except that 20 parts by mass of a hydrogenated styrene-based thermoplastic elastomer (SEBS) having no polar groups (product name "Tuftec (registered trademark) H1041", manufactured by Asahi Kasei Corporation: base polymer 2) was used instead of base polymer 1.

[0085] Example 5 Hot melt adhesive composition 5 was produced in the same manner as in Example 1, except that 16 parts by mass of the modified hydrogenated petroleum resin 2 obtained in Production Example 4 and 44 parts by mass of the unmodified hydrogenated petroleum resin obtained in Production Example 1 were used as the petroleum resins in Example 1.

[0086] Example 6 In Example 5, a hot melt adhesive composition 6 was produced in the same manner as in Example 5, except that 20 parts by mass of a hydrogenated styrene-based thermoplastic elastomer (SEBS) having no polar groups (product name "Tuftec (registered trademark) H1041", manufactured by Asahi Kasei Corporation: base polymer 2) was used instead of base polymer 1.

[0087] Comparative Example 1 A hot melt adhesive composition C1 was produced in the same manner as in Example 1, except that 60 parts by mass of the unmodified hydrogenated petroleum resin obtained in Production Example 1 was used instead of the modified hydrogenated petroleum resin 2 in Example 1.

[0088] Comparative Example 2 In Example 2, a hot melt adhesive composition C2 was produced in the same manner as in Example 2, except that 60 parts by mass of the unmodified hydrogenated petroleum resin obtained in Production Example 1 was used instead of the modified hydrogenated petroleum resin 2.

[0089] The compositions of the obtained hot melt adhesive compositions 1 to 6 and C1 to C2 are shown in Table 2. Furthermore, holding power tests were carried out on the hot melt adhesive compositions 1 to 6 and C1 to C2, and the results are shown in Tables 3 and 4. Table 3 shows the holding power, and Table 4 shows the ratio of the holding power of the aged sample to the holding power of the sample before exposure (exposure day 0). The holding power ratio was calculated using the following formula. Retention ratio (%) = retention of aged sample / retention of sample before exposure × 100

[0090] [Table 2]

[0091] [Table 3]

[0092] [Table 4]

[0093] As is clear from the results in Tables 3 and 4, the hot melt adhesive composition of the present invention containing the modified hydrogenated petroleum resin (A1) has good adhesive holding power over a long period of time, even after exposure to high-temperature and high-humidity conditions, and the initial adhesive holding power improves over time, indicating an excellent holding power ratio.

[0094] It is also clear that by combining the modified hydrogenated petroleum resin (A1) with a base polymer having a polar group, both the adhesive holding power and the holding power ratio are improved compared to when it is combined with a base polymer not having a polar group.

Claims

1. A petroleum resin (A) having a modified petroleum resin (A1) that satisfies the following (a) to (c): a base polymer (B); A moisture-curable hot melt adhesive composition comprising: (a) Contains 0.1 to 10 mass% silicon element in terms of silicon atoms (b) Weight average molecular weight of 500 to 5,000 (c) Molecular weight distribution (Mw / Mn) of 1.1 to 3.5

2. A petroleum resin (A) having a modified petroleum resin (A1) that satisfies the following (a) to (c): a base polymer (B) having a polar group; 1. A hot melt adhesive composition comprising: (a) Contains 0.1 to 10 mass% silicon element in terms of silicon atoms (b) Weight average molecular weight of 500 to 5,000 (c) Molecular weight distribution (Mw / Mn) of 1.1 to 3.5

3. The hot melt adhesive composition according to claim 1 or 2, wherein the modified petroleum resin (A1) contains 0.2 to 8.0 mass% silicon element in terms of silicon atoms.

4. The hot melt adhesive composition according to claim 1 or 2, wherein the petroleum resin (A) consists of the modified petroleum resin (A1) and an unmodified petroleum resin (A2).

5. The petroleum resin (A) contains 20% by mass or more and less than 100% by mass of the modified petroleum resin (A1) and more than 0% by mass and 80% by mass or less of the unmodified petroleum resin (A2). The hot melt adhesive composition according to claim 4.

6. 3. The hot melt adhesive composition according to claim 2, wherein the base polymer (B) having a polar group is a base polymer modified with at least one selected from the group consisting of maleic anhydride and an amine.

7. The base polymer (B) has an acid value of 1 to 10 mg CH ３ 7. The hot melt adhesive composition of claim 6, wherein the viscosity of the hot melt adhesive composition is 1000 MPa.

8. The hot melt adhesive composition according to claim 1 or 2, comprising 20% ​​by mass or more and 70% by mass or less of the petroleum resin (A).

9. Further, a plasticizer (C) is contained, 3. The hot melt adhesive composition according to claim 1, comprising 20% ​​by mass or more and 70% by mass or less of the petroleum resin (A), 10% by mass or more and 30% by mass or less of the base polymer (B), and 10% by mass or more and 30% by mass or less of the plasticizer (C).

10. The hot melt adhesive composition according to claim 1 or 2, which is for use in automotive exterior products, solar panels, building and civil engineering materials, or textile and leather products.

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