JPWO2018074070A1 - Hot melt adhesive - Google Patents

Abstract

  One aspect of the present invention is a hot melt adhesive comprising a thermoplastic polymer, a tackifier, and a softener, wherein the softener comprises an acid-modified oil modified with at least one of a carboxylic acid and a carboxylic acid anhydride. It is.

Description

  The present invention relates to hot melt adhesives.

  The hot melt adhesive is applied to an adherend which is a bonding object in a molten state by heating, and the adherends are kept in contact with each other through the melted hot melt adhesive. As a result, adherends are adhered to each other. Such hot melt adhesives include, for example, packaging fields such as cardboard and small boxes, sanitary materials such as disposable diapers and sanitary products, bookbinding fields, plywood fields, woodworking fields, automobile fields, home electronics fields, and housing fields, etc. It is used in various fields.

  In addition, since the hot melt adhesive is used in a molten state by heating as described above, the solvent is not particularly required. For this reason, hot melt adhesives are preferably used as adhesives with high safety to the human body, for example, in the field of sanitary materials. Specifically, in disposable sanitary materials such as disposable diapers and sanitary products, hot melt adhesives are widely used for fixing and assembling the constituent members.

  When a hot melt adhesive is used in such a sanitary material field, there are many opportunities to contact with water such as body fluid from the use. Some hot melt adhesives are known to have reduced adhesion upon contact with moisture, ie, low adhesion in the wet state. With such a hot melt adhesive, in the field where there are many opportunities of contact with moisture, adhesion between constituent materials is not maintained at the time of use of the product or the like, and the product itself may be disintegrated. For this reason, hot melt adhesives are required to maintain adhesion in the wet state.

  As an adhesive agent for the purpose of improving the adhesiveness in such a wet state etc., the adhesive agent of patent document 1-4 is mentioned, for example.

  Patent Document 1 discloses a hot block containing a thermoplastic block copolymer which is a copolymer of a vinyl-based aromatic hydrocarbon and a conjugated diene compound, and a wax modified with a carboxylic acid and / or a carboxylic acid anhydride. Melt adhesives are described. According to Patent Document 1, it is disclosed that wet adhesion is improved, and more preferably at least one selected from low temperature adhesion, viscosity, adhesion, odor and economy is improved.

  Further, Patent Document 2 discloses a disposable product containing a propylene homopolymer having a melting point of 100 ° C. or less obtained by polymerizing propylene using a metallocene catalyst, and a wax modified with a carboxylic acid and / or a carboxylic acid anhydride. Hot melt adhesives are described. According to Patent Document 2, it is disclosed that it is suitable for high-speed coating, and excellent in adhesiveness in a wet state and low-temperature coating.

  Further, Patent Document 3 describes a hot melt adhesive containing an acid-modified thermoplastic block copolymer, a tackifying resin, a plasticizing oil, and a wax. According to Patent Document 3, even when the adherend is in a dry state or in a wet state, it exhibits excellent adhesiveness from immediately after adhesion to after long-term storage. It is disclosed.

  Further, Patent Document 4 discloses a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene compound, a thermoplastic block copolymer containing at least one of hydrogenated products thereof, and unsaturated carboxylic acids or the same A hot melt adhesive is described which comprises an acid modified petroleum resin which has been acid modified with an anhydride. According to Patent Document 4, it is disclosed that the wet adhesion is improved with respect to the component without causing a decrease in thermal stability and generation of an odor.

  By the way, in the bonding method using a hot melt adhesive, first, the hot melt adhesive melted by heating is applied to an adherend using a coating machine or the like. The adherends can be adhered to each other by holding the other adherend in contact with the applied hot melt adhesive.

  Further, in the field of sanitary materials such as disposable diapers, it is required to improve the texture. For this reason, it is considered to improve the softness of a paper diaper or the like and improve the texture by thinning a constituent material which is an adherend by a hot melt adhesive. However, when the constituent material is made thinner, the heat resistance tends to decrease. When a hot melt adhesive melted by heating is applied to such a low heat-resistant constituent material, the constituent material may be damaged such as melting or deformation. And the damage by the heat of this constituent material tended to occur notably, when the temperature of the hot melt adhesive to apply or the quantity of the hot melt adhesive to apply were large. Therefore, for the purpose of being able to use such a low heat resistant construction material, low temperature application and small amount application of a hot melt adhesive are required in the field of sanitary materials. Specifically, even if the amount of the applied hot melt adhesive is reduced by lowering the temperature for melting the hot melt adhesive and reducing the nozzle diameter of the coating machine, etc. It is required to ensure sufficient adhesion.

  In the case of such low temperature application and small amount application, the heat quantity of the hot melt adhesive at the time of application decreases, the hot melt adhesive hardly penetrates into the adherend, and the adhesive strength, particularly the wet adhesive strength is enhanced. It tends to be difficult. In addition, with a hot melt adhesive having poor coatability, such as high viscosity, suitable coating can not be realized. Accordingly, the hot melt adhesive is also required to have excellent coatability.

  Some hot melt adhesives have poor adhesion under low temperature conditions, and there are also hot melt adhesives that may cause poor adhesion in winter and cold environments. In order to be usable in winter and cold environments, hot melt adhesives are also required to have excellent adhesion under low temperature conditions.

  Therefore, the hot melt adhesive is required not only to be excellent in adhesiveness in the wet state but also to be excellent in coatability and adhesiveness under low temperature conditions.

JP 2007-169531 A JP, 2013-64054, A JP 2005-104996 A JP, 2015-91917, A

  An object of the present invention is to provide a hot melt adhesive excellent in wet adhesion, coatability, and adhesion at low temperature conditions.

  One aspect of the present invention includes a thermoplastic polymer, a tackifier, and a softener, and the softener includes an acid-modified oil modified with at least one of a carboxylic acid and a carboxylic acid anhydride. Hot melt adhesive.

  The above as well as other objects, features and advantages of the present invention will become apparent from the following detailed description.

  As the hot melt adhesive, although the adhesive described in Patent Documents 1 to 4 as described above can improve the adhesiveness in the wet state, in the case of low temperature coating and small amount coating, etc. The inventor found that problems such as may occur.

  For example, in the case where a wax modified with a carboxylic acid and / or a carboxylic anhydride as described in Patent Document 1 and Patent Document 2 is included, there is a case where a compatibility defect occurs and the coatability is lowered.

  In addition, even when the thermoplastic polymer or tackifier contained in the hot melt adhesive as described in Patent Document 3 and Patent Document 4 is acid-modified, it causes viscosity increase and compatibility failure of the hot melt adhesive. And coatability may be reduced. Furthermore, in the case of such a hot melt adhesive, the adhesion under low temperature conditions may be insufficient, which may cause adhesion failure in winter and cold environments.

  Therefore, the hot melt adhesive is required not only to be excellent in adhesiveness in the wet state but also to be excellent in coatability and adhesiveness under low temperature conditions.

  As a result of various investigations, the inventor of the present invention has achieved the above object, such as providing a hot-melt adhesive excellent in wet adhesion, coatability, and adhesion at low temperature conditions. I found it to be done.

  Hereinafter, although the embodiment concerning the present invention is described, the present invention is not limited to these.

  A hot melt adhesive according to an embodiment of the present invention comprises a thermoplastic polymer, a tackifier and a softener. And the said softening agent contains the acid modified oil modified | denatured by at least one of carboxylic acid and carboxylic acid anhydride. This hot melt adhesive contains a thermoplastic polymer, a tackifier and a softener, and the softener contains an acid-modified oil modified with at least one of a carboxylic acid and a carboxylic anhydride. There is no particular limitation. This hot melt adhesive contains the acid-modified oil, thereby enhancing the adhesion in the wet state while maintaining the performance that the conventional hot melt adhesive can exhibit, such as adhesion, etc. Engineering properties and adhesion under low temperature conditions can also be enhanced. In addition, a hot melt adhesive is solid (solid) at normal temperature, has fluidity by heating, can be applied to an adherend to be adhered, and is cooled after application. It is an adhesive which solidifies and adheres adherends.

  First, the thermoplastic polymer used in the present embodiment is not particularly limited as long as it is a thermoplastic polymer used as a component constituting the hot melt adhesive. Moreover, as this thermoplastic polymer, a thermoplastic polymer etc. which are used as a base polymer which is a main component of a hot-melt-adhesive agent are mentioned. Specific examples of the thermoplastic polymer include thermoplastic polymers of elastomer type, olefin type, ethylene vinyl acetate copolymer (EVA) type, polyester type, polyamide type, and polyacrylic type. Among these, in the present embodiment, the thermoplastic elastomer polymer and the thermoplastic olefin polymer are preferable, and the thermoplastic thermoplastic polymer is more preferable.

  The elastomeric thermoplastic polymer is not particularly limited as long as it is used as an elastomeric thermoplastic polymer in a hot melt adhesive, and has, for example, a constitutional unit (conjugated diene unit) based on a conjugated diene compound The conjugated diene polymer which is a polymer etc. are mentioned. Further, specific examples of the elastomeric thermoplastic polymer include thermoplastic block copolymers which are copolymers of conjugated diene compounds and vinyl aromatic hydrocarbons. That is, such a thermoplastic block copolymer is preferably used as the thermoplastic polymer.

  The conjugated diene compound is not particularly limited as long as it is a diolefin compound having at least one pair of conjugated double bonds. Specific examples of conjugated diene compounds include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene etc. are mentioned.

  The vinyl aromatic hydrocarbon is not particularly limited as long as it is an aromatic hydrocarbon having a vinyl group. Specific examples of the vinyl-based aromatic hydrocarbon include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, vinyl naphthalene and vinyl Anthracene etc. are mentioned.

  The conjugated diene polymer may be a hydrogenated conjugated diene copolymer or a non-hydrogenated conjugated diene copolymer without hydrogenation. .

  The thermoplastic polymer is preferably the thermoplastic block copolymer, and specific examples thereof include, for example, styrene-butadiene block copolymer, styrene-isoprene block copolymer, hydrogenated styrene-butadiene block copolymer, and hydrogenation. Styrene-isoprene block copolymer and the like. Also, these copolymers include ABA type triblock copolymers. Examples of the styrene-butadiene block copolymer include styrene-butadiene-styrene block copolymer (SBS) and the like. Moreover, as a styrene- isoprene block copolymer, a styrene-isoprene-styrene block copolymer (SIS) etc. are mentioned, for example. Moreover, as a styrene-butadiene block copolymer hydrogenated, the styrene- ethylene- butylene- styrene block copolymer (SEBS) etc. are mentioned, for example. Further, as the hydrogenated styrene-isoprene block copolymer, for example, styrene-ethylene-propylene-styrene block copolymer (SEPS) and the like can be mentioned.

  When the thermoplastic block copolymer as described above is used as the thermoplastic polymer, it exhibits excellent adhesion and adhesiveness, but depending on the material of the adherend, etc., adhesion in a wet state There was a case where the sex decreased. With the hot melt adhesive according to the present embodiment, the adhesiveness in the wet state can be enhanced while maintaining other performances, so that the excellent adhesiveness and adhesiveness of the thermoplastic block copolymer can be obtained. The adhesion in the wet state can be enhanced while maintaining the etc. For this reason, it is preferable to use the said thermoplastic block copolymer as a thermoplastic polymer.

  The olefin-based thermoplastic polymer is not particularly limited as long as it is used as an olefin-based thermoplastic polymer in a hot melt adhesive. Further, as the olefin-based thermoplastic polymer, for example, a Ziegler-Natta catalyst or a polyolefin-based compound which is solid at room temperature and polymerized with a single site catalyst can be mentioned. Specific examples of the olefin-based thermoplastic polymer include polyethylene, polypropylene, poly-1-butene, polyisobutylene, random copolymers or blocks in any ratio of propylene and at least one of ethylene and 1-butene. Copolymers, ethylene-propylene-diene terpolymers containing a diene component in any ratio of ethylene and propylene, random copolymers or block copolymers of ethylene or propylene with vinyl compounds, etc., random polypropylene, block Polypropylene, homopolypropylene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer, ethylene / 1-octene copolymer, propylene / ethylene copolymer, propylene / ethylene / copolymer 1-butene Combined, 1-butene homopolymer, 1-butene / ethylene copolymer, 1-butene / propylene copolymer, propylene / 1-butene copolymer, ethylene / vinyl acetate copolymer, ethylene / methacrylic acid copolymer And a copolymer of ethylene, methyl methacrylate and the like. As the olefin-based thermoplastic polymer, for example, among the above-exemplified compounds, an olefin-based polymer obtained by polymerizing an olefin (alkene) such as α-olefin as a monomer is preferable. Specifically as said olefin type polymer, a poly (alpha) -olefin polymer etc. are mentioned. More specifically, as the poly α-olefin polymer, an amorphous-poly α-olefin polymer (APAO), a homopolymer of propylene (propylene homopolymer), and the like are preferable. More specifically, as the propylene homopolymer, a propylene homopolymer obtained by polymerizing propylene using a metallocene catalyst is preferable.

  The EVA-based thermoplastic polymer is not particularly limited as long as it is used as an EVA-based thermoplastic polymer in a hot melt adhesive, and examples thereof include a copolymer synthesized from ethylene and vinyl acetate, etc. Be

  The polyester-based thermoplastic polymer is not particularly limited as long as it is used as a polyester-based thermoplastic polymer in a hot melt adhesive. Examples of polyester-based thermoplastic polymers include polyesters polymerized using a dimer acid as a monomer.

  The polyamide-based thermoplastic polymer is not particularly limited as long as it is used as a polyamide-based thermoplastic polymer in a hot melt adhesive, and examples thereof include polyamide.

  The polyacrylic thermoplastic polymer is not particularly limited as long as it is used as a polyacrylic thermoplastic polymer in a hot melt adhesive, and, for example, polyacrylic acid ester, polymethacrylic acid ester, etc. It can be mentioned.

  As the thermoplastic polymer, the thermoplastic polymers exemplified above may be used alone, or two or more may be used in combination.

  The weight average molecular weight of the thermoplastic polymer varies depending on the type of the thermoplastic polymer and the like, and is not particularly limited. For example, it is preferably 10,000 to 500,000, and more preferably 50,000 to 300,000. When the molecular weight of the thermoplastic polymer is too small, the cohesion tends to be reduced and the temporal stability tends to be reduced. When the molecular weight of the thermoplastic polymer is too large, the melt viscosity tends to increase and the coatability tends to decrease. In addition, the weight average molecular weight here should just be a weight average molecular weight measured by the general measuring method, for example, the weight average molecular weight etc. which were measured using gel permeation chromatography (GPC) etc. are mentioned.

  The tackifier used in the present embodiment is not particularly limited as long as it is a tackifier generally used for a hot melt adhesive. Examples of tackifiers include rosin resins, terpene resins, and petroleum resins.

  Examples of the rosin resin include natural rosins such as gum rosin, tall rosin and wood rosin, asymmetric rosins, polymerized rosins, glycerin esters of these rosins, and pentaerythritol esters. In addition, the rosin resin may be one obtained by not adding hydrogen to each of the above rosin resins, or one obtained by hydrogenation, that is, a hydrogenated product (hydrogenated product) of the above rosin resin, It is also good.

  Examples of the terpene resin include terpene resin, hydrocarbon modified terpene resin, aromatic modified terpene resin, and phenolic modified terpene resin. Further, the terpene resin may be one obtained by not adding each of the above-mentioned terpenes, or one obtained by hydrogenation, that is, a hydrogenated product (hydrogenated product) of the above terpene resin. . Moreover, as terpene resin, aromatic modified terpene resin hydride, aromatic modified terpene resin, and terpene resin hydride are preferable, and aromatic modified terpene resin hydride is more preferable.

  Examples of the petroleum-based resin include aliphatic petroleum resins, alicyclic petroleum resins, aromatic petroleum resins, and hydrogenated products (hydrogenated products) of these. Further, as the petroleum resin hydride, aliphatic petroleum resin hydride, alicyclic petroleum resin hydride and aromatic petroleum resin hydride are preferable. Moreover, as an alicyclic type petroleum resin hydride, hydrogenated C9 petroleum resin, hydrogenated dicyclopentadiene type petroleum resin, etc. are mentioned, for example.

  Moreover, as the tackifier, the tackifiers exemplified above may be used alone or in combination of two or more.

  The softener used in the present embodiment is not particularly limited as long as it contains an acid-modified oil which has been modified with at least one of a carboxylic acid and a carboxylic acid anhydride.

  The acid-modified oil is not particularly limited as long as it is an oil that can be used as a softener in a hot melt adhesive and is modified with at least one of a carboxylic acid and a carboxylic acid anhydride. As an acid modified oil, for example, an acid modified oil obtained by adding at least one of a carboxylic acid and a carboxylic acid anhydride to an oil, and a raw material having an olefin skeleton such as α-olefin are subjected to an ene reaction to form a carboxylic acid. And acid-modified oils obtained by adding and synthesizing at least one of carboxylic acid anhydrides and the like.

  It will not specifically limit, if it is a softener which can be used as a softener in a hot melt adhesive as a softener before carrying out acid modification. As a softening agent, oil etc. are mentioned, for example. Here, the oil is a liquid which is liquid at normal temperature and pressure, and examples thereof include liquid substances having no melting point. Moreover, as said oil, the liquid hydrocarbon etc. which do not have melting | fusing point are mentioned, for example. Examples of the softener before the acid modification, ie, the oil before the modification, include mineral oils, synthetic oils, vegetable oils, fatty acid esters and the like.

  Specific examples of the mineral oils include process oils and liquid paraffin. The process oil is an oil generally used as a plasticizer such as rubber or thermoplastic elastomer, and is an oil produced in so-called petroleum refining or the like. The process oil is generally a mixture containing an aromatic ring, a naphthene ring and a paraffin chain, and is roughly classified into a paraffinic process oil, a naphthenic process oil and an aromatic process oil. Process oil is paraffin-based, paraffin-based carbon having 50% or more of total carbon number, naphthene-based, having 30% or more naphthenic ring carbon, and 30% or more aromatic carbon It distinguishes from the aromatic system. The paraffinic process oil includes paraffinic compounds having 4 to 155 carbon atoms, preferably paraffinic compounds having 4 to 50 carbon atoms. Specific examples of the paraffin-based process oil include butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tetradecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, henicosane, docosan, trichosan. , Tetracosan, pentadecosan, hexacosan, heptacosane, octacosan, nonacosane, triacontan, hementacontan, dotriacontan, pentatriacontan, pentaconecontan, hexacontan, and n-paraffins such as hemptacontan, isobutane, isopentane, neopentane, isohexane, isopentane , Neohexane, 2,3-dimethylbutane, various methylhexanes, 3-ethylpentane, various dimethylpentanes, 2,2,3-3 Lymethylbutane, 3-methylheptane, various dimethylhexanes, various trimethylpentanes, isononane, 2-methylnonane, isodecane, isoundecane, isododecane, isotridecane, isotetradecane, isopentadecane, isooctadecane, isonanodecane, isoeicosane, and 4-ethyl-5-one Examples thereof include isoparaffins such as methyl octane and derivatives of these saturated hydrocarbons. These paraffinic compounds selected can be used in a mixture and are liquid at room temperature.

  Specific examples of synthetic oils include phosphoric acid esters, chlorinated paraffins, ethylene-α-olefin oligomers, polybutenes, low molecular weight polybutadienes, polyisoprenes, and hydrogenated products thereof, which are liquid at room temperature. .

  Specific examples of vegetable oils include olive oil, carnauba wax, rice germ oil, corn oil, sasanqua oil, camellia oil, castor oil, jojoba seed oil, and Eucalyptus leaf oil.

  Specific examples of the fatty acid esters include isopropyl myristate, octyl dodecyl thrysylate, glycerin triisooctoate, diisopropyl adipate, diethyl sebacate, cetyl ethylhexanoate, cetyl palmitate, ethylhexyl palmitate, isopropyl palmitate, Medium-chain fatty acid triglyceride, ethylene glycol salicylate, glycol distearate and the like can be mentioned.

  Among the oils exemplified above, paraffinic oils such as liquid paraffin, naphthenic oils, and aromatic oils are preferable as the softening agent before the acid modification, that is, the oil before the modification. In addition, as the softener before the modification, the oils exemplified above may be used alone, or two or more kinds may be used in combination.

It is preferable that the oil before the said modification | denaturation point is -30 degreeC or more. In addition, it is preferable that the oil before the modification has a kinematic viscosity of 5 to 5000 mm ² / sec. If the kinematic viscosity is too small, the heat resistance is likely to decrease, and if the kneading temperature is high, there is a risk of ignition. Moreover, when the said kinematic viscosity is too large, there exists a possibility of a coating property fall by melt viscosity increase of a hot melt. The oil before the modification preferably has a flash point of 150 ° C. or higher, preferably 200 ° C. or higher, and more preferably 250 ° C. or higher.

  The carboxylic acid used for the said acid modification is not specifically limited. Examples of the carboxylic acid used for the acid modification include maleic acid, fumaric acid, succinic acid, phthalic acid, glutaric acid, itaconic acid, acrylic acid, and methacrylic acid.

  The carboxylic acid anhydride used for the said acid modification is not specifically limited. Examples of the carboxylic acid anhydride used for the acid modification include maleic anhydride (maleic anhydride), succinic anhydride, phthalic anhydride, and glutaric anhydride.

  As the carboxylic acid, maleic acid, fumaric acid and acrylic acid are preferable, and maleic acid is more preferable. Moreover, as said carboxylic acid anhydride, a maleic anhydride is preferable. Moreover, as what is used for the said acid modification, the maleic anhydride which is a carboxylic acid anhydride is preferable.

  As said carboxylic acid and said carboxylic acid anhydride, said carboxylic acid and carboxylic acid anhydride may be used independently, and may be used in combination of 2 or more type.

  Examples of the acid-modified oil include, for example, an acid-modified oil obtained by modifying an oil before the modification with at least one of the carboxylic acid and the carboxylic acid anhydride. Examples of the acid-modified oil include oils having a succinic acid skeleton in the molecule.

  The method for producing the acid-modified oil is not particularly limited as long as it can produce an acid-modified oil which has been modified with at least one of a carboxylic acid and a carboxylic acid anhydride. Specific examples of the method for producing the acid-modified oil include a method in which at least one of a carboxylic acid and a carboxylic acid anhydride is added to an oil as a raw material to cause an addition reaction. In the addition reaction, a radical generator may be used. In addition, as a method for producing an acid-modified oil, a method of causing an addition reaction by heating and melting an oil as a raw material, a radical generator, and at least one of a carboxylic acid and a carboxylic acid anhydride, and the like is mentioned. Be Under the present circumstances, as a temperature at the time of melt mixing, 160-200 ° C etc. are mentioned, for example. Moreover, as an apparatus which implement | achieves this method, if an oil raw material and at least one of carboxylic acid and carboxylic acid anhydride can be made to react, it will not be specifically limited. As this apparatus, for example, a melt reaction tank having a stirring function filled with an inert gas can be mentioned.

  The radical generator used for the addition reaction is not particularly limited as long as it can promote the addition reaction, and can be appropriately selected from known ones. As a radical generating agent, an organic peroxide type compound etc. are mentioned, for example. As an organic peroxide type compound, for example, di-tert-butyl peroxide, dicumyl peroxide, tert-butylcumyl peroxide, benzoyl peroxide, dilauryl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide Oxide, 1,1-bis (tert-butylperoxy) -3,5,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 1,1-bis ( tert-Butylperoxy) -cyclohexane, cyclohexanone peroxide, tert-butylperoxybenzoate, tert-butylperoxyisobutyrate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert -Butylpa 2-ethyl hexanoate, tert- butylperoxy isopropyl carbonate include cumylperoxy octoate, and the like. Among these, dicumyl peroxide is preferable.

  The addition amount of the radical generator is not particularly limited as long as the addition reaction can be suitably advanced. The addition amount of the radical generating agent is preferably 1 to 50% by mass, and more preferably 10 to 30% by mass, with respect to the total mass of the carboxylic acid and the carboxylic anhydride. By setting the addition amount of the radical generating agent within the above range, it is possible to cause an addition reaction to the main chain while suppressing the reduction in molecular weight of the acid-modified oil.

  Further, as described above, the softener used in the present embodiment may contain the acid-modified oil. That is, the softener may be made of the acid-modified oil. The softener may include not only the acid-modified oil but also softeners other than the acid-modified oil. Moreover, as softeners other than the said acid modification oil, if it is a softener contained in a hot-melt-adhesive, it will not be specifically limited. Specifically as a softener other than the said acid modification oil, the thing similar to oil before the said acid modification | denaturation, etc. are mentioned.

  The content of the acid-modified oil is not particularly limited as long as the desired properties intended by the present invention are not impaired. Specifically, the content of the acid-modified tackifier is preferably 0.02 to 100 parts by mass, and more preferably 0.03 to 70 parts by mass with respect to 100 parts by mass of the softener. Is more preferable, and 1 to 55 parts by mass is more preferable. If the content of the acid-modified oil is too small, the effect of containing the acid-modified oil can not be sufficiently exhibited, and the adhesiveness in the wet state tends not to be sufficiently enhanced. Further, as described above, the softener may be made of the acid-modified oil, but if the content of the acid-modified oil is too large, the low temperature adhesion may be reduced or the cohesion may be insufficient. Adhesion may be reduced.

  In the hot melt adhesive, the content of each of the thermoplastic polymer, the tackifier and the softener is not particularly limited as long as the desired properties intended by the present invention are not impaired. As each said content, the following ranges are mentioned, for example.

  The content of the thermoplastic polymer is preferably 10 to 75% by mass, more preferably 15 to 65% by mass, and more preferably 15 to 30% by mass with respect to the hot melt adhesive. More preferable. That is, it is preferable that content of the said thermoplastic polymer is 10-75 mass parts with respect to 100 mass parts of said hot-melt adhesives. When the content of the thermoplastic polymer is too low, the cohesion tends to be insufficient. Moreover, when there is too much content of the said thermoplastic polymer, melt viscosity will rise and there exists a tendency for coating property to fall.

  The content of the tackifier is preferably 20 to 80% by mass, more preferably 35 to 70% by mass, and preferably 40 to 70% by mass with respect to the hot melt adhesive. More preferable. That is, it is preferable that content of the said tackifier is 20-80 mass parts with respect to 100 mass parts of said hot-melt adhesives. If the content of the tackifier is too small, the adhesive strength tends to decrease and the adhesive strength to decrease. In addition, when the content of the tackifier is too large, the flexibility and the flexibility are lost, and the stress dispersibility tends to decrease and the holding power tends to decrease.

  Further, the content of the softener is preferably 5 to 40% by mass, more preferably 10 to 25% by mass, and more preferably 15 to 25% by mass with respect to the hot melt adhesive. Is more preferred. That is, it is preferable that content of the said softener is 5-40 mass parts with respect to 100 mass parts of said hot-melt adhesives. When the content of the softener is too small, the melt viscosity tends to increase and the coatability tends to decrease. In addition, when the content of the softener is too large, the cohesion force tends to be lowered, and the adhesive force and the holding force tend to be lowered.

  The hot melt adhesive according to the present embodiment may contain additives other than the thermoplastic polymer, the tackifier, and the softener, as long as the desired properties intended by the present invention are not impaired. Good. Specific examples of the additive include an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, a filler, a surfactant, a coupling agent, a colorant, an antistatic agent, a flame retardant, a wax, and the like. And additives such as plasticizers. The hot melt adhesive is solid at normal temperature and may contain a solvent, but preferably does not contain a solvent. The hot melt adhesive preferably comprises, for example, the thermoplastic polymer, the tackifier, the softener, and the additive.

  Moreover, as antioxidant, a phenolic antioxidant, organic sulfur type antioxidant, phosphorus type antioxidant etc. are mentioned, for example. Examples of phenolic antioxidants include 2,6-di-tert-butyl-4-methylphenol, n-octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2 -Tert-Butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxy) Phenyl) propionate] methane etc. are mentioned. Examples of organic sulfur-based antioxidants include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, pentaerythyl. Examples include lytyl tetrakis (3-lauryl thiopropionate) and the like. Examples of phosphorus antioxidants include tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite and the like. As these antioxidants, the above-exemplified antioxidants may be used alone or in combination of two or more.

  The wax is not particularly limited as long as it is a wax contained in a hot melt adhesive. Examples of the wax include synthetic waxes, petroleum waxes, and natural waxes. Examples of synthetic waxes include, for example, polyolefin waxes such as Fischer-Tropsch wax, polyethylene wax and polypropylene wax. Examples of petroleum waxes include paraffin wax, microcrystalline wax, and petratam. Examples of natural waxes include montan wax, wood wax, carnauba wax, beeswax and castor wax. As these waxes, the waxes exemplified above may be used alone, or two or more of them may be used in combination.

  It will not specifically limit, if it is a manufacturing method which can manufacture the hot melt adhesive of the said structure as a method of manufacturing the hot melt adhesive which concerns on this embodiment. As a method of manufacturing a hot melt adhesive, the method of heating and melting the component which comprises a hot melt adhesive, stirring and kneading etc. is mentioned, for example. By doing so, a hot melt adhesive having high dispersibility of the components constituting the hot melt adhesive can be obtained. Moreover, as an apparatus which implement | achieves this method, the stirring kneader equipped with the heating apparatus, a roll, a Banbury mixer, a kneader, an extruder etc. are mentioned, for example.

  The bonding method using a hot melt adhesive is not particularly limited as long as it can be used as a bonding method using a hot melt adhesive. As a bonding method using a hot melt adhesive, for example, the hot melt adhesive is melted by heating. Then, the hot melt adhesive in the molten state is applied to an adherend which is a bonding target. The hot melt adhesive is cooled and solidified by being left in contact with the other adherend on the applied hot melt adhesive. The solidified hot melt adhesive bonds the adherends to each other.

  The method for applying the hot melt adhesive is not particularly limited as long as the hot melt adhesive can be suitably applied to the adherend. The application methods are roughly classified into, for example, a contact application method and a non-contact application method. The contact coating method refers to a coating method in which a device used for coating such as a coating machine is in contact with an adherend when the hot melt adhesive is coated. Further, the non-contact coating method refers to a coating method in which the coating machine or the like is not in contact with the adherend when the hot melt adhesive is applied. Examples of the contact coating method include slot coating (slot coat gun and the like manufactured by Nordson Co., Ltd.) and roll coater coating. In addition, as a non-contact application method, for example, spiral coating (a spiral spray nozzle etc. made by Sun Tool Co., Ltd.) that can be applied in a spiral shape, spray coating that can be applied in a wavy shape (Omega coat etc. made by ITW Dynatech Co., Ltd.) And spray coating (such as a curtain spray head manufactured by Sun Tool Co., Ltd.) which can be applied in a surface state, and dot coating which can be applied in a dot shape. The hot melt adhesive according to the present embodiment is suitable for spiral coating. Spiral coating is a method of non-contact coating of an adhesive with air in a spiral manner by intermittent or continuous coating.

  Although the present specification discloses various aspects of the technology as described above, the main technologies are summarized below.

  One aspect of the present invention includes a thermoplastic polymer, a tackifier, and a softener, and the softener includes an acid-modified oil modified with at least one of a carboxylic acid and a carboxylic acid anhydride. Hot melt adhesive.

  According to such a configuration, it is possible to provide a hot melt adhesive excellent in adhesion in the wet state, coatability, and adhesion under low temperature conditions.

  In the hot melt adhesive, preferably, the carboxylic acid is maleic acid, and the carboxylic acid anhydride is maleic acid anhydride.

  According to such a configuration, it is possible to provide a hot melt adhesive which is more excellent in adhesiveness in wet state, coatability, and adhesiveness under low temperature conditions.

  In the hot melt adhesive, it is preferable that the acid-modified oil is an oil having a succinic acid skeleton in its molecule.

  According to such a configuration, it is possible to provide a hot melt adhesive which is more excellent in adhesiveness in wet state, coatability, and adhesiveness under low temperature conditions.

  In the hot melt adhesive, the content of the acid-modified oil is preferably 0.02 to 100 parts by mass with respect to 100 parts by mass of the softener.

  According to such a configuration, it is possible to provide a hot melt adhesive which is more excellent in adhesiveness in wet state, coatability, and adhesiveness under low temperature conditions.

  In the hot melt adhesive, it is preferable that the oil before the modification in the acid-modified oil is at least one selected from the group consisting of paraffinic oil, naphthenic oil, and aromatic oil. .

  According to such a configuration, it is possible to provide a hot melt adhesive which is more excellent in adhesiveness in wet state, coatability, and adhesiveness under low temperature conditions.

  In the hot melt adhesive, it is preferable that the thermoplastic polymer is a copolymer of a conjugated diene compound and a vinyl aromatic hydrocarbon, or an olefin polymer.

  A hot melt adhesive containing a copolymer of a conjugated diene compound and a vinyl aromatic hydrocarbon or an olefin polymer as the thermoplastic polymer exhibits excellent adhesion and adhesiveness, but is an adherend. Depending on the material, etc., the adhesion in the wet state may be reduced. In the case of a hot melt adhesive according to one aspect of the present invention, that is, a hot melt adhesive containing the acid-modified oil, the thermoplastic polymer may include the copolymer and the olefin polymer. Also, the adhesion in the wet state is excellent. Therefore, according to the above configuration, it is possible to provide a hot melt adhesive which is more excellent in coatability and adhesion under low temperature conditions and further excellent in adhesion in the wet state.

  In the hot melt adhesive, the copolymer is a group consisting of styrene-butadiene block copolymer, styrene-isoprene block copolymer, hydrogenated styrene-butadiene block copolymer, and hydrogenated styrene-isoprene block copolymer. It is preferable that it is at least one selected from

  According to such a configuration, it is possible to provide a hot melt adhesive which is more excellent in adhesion in the wet state, and further excellent in coatability and adhesion under low temperature conditions.

  In the hot melt adhesive, the olefin-based polymer is preferably a poly α-olefin polymer.

  According to such a configuration, it is possible to provide a hot melt adhesive which is more excellent in adhesion in the wet state, and further excellent in coatability and adhesion under low temperature conditions.

  ADVANTAGE OF THE INVENTION According to this invention, the hot-melt adhesive excellent in the adhesiveness in a wet state, coating property, and adhesiveness under low temperature conditions can be provided.

  Hereinafter, the present invention will be more specifically described by way of examples, but the scope of the present invention is not limited thereto.

  First, each component used when preparing a hot melt adhesive in this example will be described.

[Thermoplastic polymer]
Thermoplastic polymer 1: styrene-butadiene-styrene block copolymer (SBS) (Asaprene T-439 manufactured by Asahi Kasei Corporation)
Thermoplastic polymer 2: styrene-butadiene-styrene block copolymer (SBS) (Asaprene T-420 manufactured by Asahi Kasei Co., Ltd.)
Thermoplastic polymer 3: Propylene homopolymer (Elmodu X400S manufactured by Idemitsu Kosan Co., Ltd.)
Thermoplastic polymer 4: Propylene homopolymer (ELMODUEX 600S manufactured by Idemitsu Kosan Co., Ltd.)
Thermoplastic polymer 5: Amorphous-poly α-olefin polymer (APAO) (VESTOPLAST 704 manufactured by Evonik)
Acid-modified thermoplastic polymer: Maleic acid-modified styrene-ethylene-butylene-styrene block copolymer (maleic acid-modified SEBS) (Tuftec M1913 manufactured by Asahi Kasei Co., Ltd.)
[Tackifier]
Tackifier 1: Aromatic modified terpene resin hydride (hydrogenated aromatic modified terpene resin) (CLEARON K-4100 manufactured by Yashara Chemical Co., Ltd.)
Tackifier 2: alicyclic petroleum resin hydride (hydrogenated C9 petroleum resin) (Arcon M-100 manufactured by Arakawa Chemical Industries, Ltd.)
Tackifier 3: Aliphatic petroleum resin hydride (hydrogenated C9 petroleum resin) (Arcon P-100 manufactured by Arakawa Chemical Industries, Ltd.)
Tackifier 4: alicyclic petroleum resin hydride (hydrogenated dicyclopentadiene petroleum resin) (Escollets 5320 manufactured by ExxonMobil)
[Softener]
Oil: Oil (Diana Flecia S32 manufactured by Idemitsu Kosan Co., Ltd.)
Acid-modified oil 1: Maleic acid-modified oil (oil having a succinic acid skeleton in the molecule) (AS-1532 manufactured by Starlight PMC Co., Ltd.)
Acid-modified oil 2: Maleic acid-modified oil (oil having a succinic acid skeleton in the molecule) (size pine SA-864 manufactured by Arakawa Chemical Industry Co., Ltd.)
Acid-modified wax: Maleic acid-modified wax (wax having a succinic acid backbone in the molecule) (Licosene PPMA6252 manufactured by Clariant Japan Co., Ltd.)
Acid-modified rubber: Maleic acid-modified liquid rubber (liquid rubber having a succinic acid skeleton in the molecule) (Krapren LIR-410, manufactured by Kuraray Co., Ltd.)
[Additive]
Antioxidant: Irganox 1010 manufactured by BASF
[Method of producing hot melt adhesive]
The above components were kneaded according to the following procedure so as to obtain the blending amounts (composition: parts by mass) shown in Table 1 below, to prepare a hot melt adhesive. The tackifier, the softener, and the additive were placed in a stirring kneader, and were sufficiently melted by stirring in a heated state so as to be 150 to 190 ° C. In the melt, the thermoplastic polymer was charged and kneaded while heated to 150 to 190 ° C., whereby the thermoplastic polymer was sufficiently melted and uniformly dispersed in the melt. . Thereafter, an acid-modified tackifier was added to the melt and stirred and kneaded. At that time, it knead | mixed until the homogeneity of the hot melt adhesive increased as much as possible. By doing so, a hot melt adhesive was produced.

[Evaluation]
(Applicability: melt viscosity)
The melt viscosity at 140 ° C. of the hot melt adhesive before curing was measured as follows. Specifically, in accordance with the measurement method described in JIS K 6682, the viscosity of the melt melted at 140 ° C. of the hot melt adhesive was measured by a Brookfield viscometer (rotor of spindle No. 27). . This viscosity is the melt viscosity at 140 ° C. of the hot melt adhesive before curing.

  Moreover, the melt viscosity at 160 ° C. of the hot melt adhesive before curing was measured by the same method.

(Adhesiveness under low temperature conditions: Low temperature adhesive strength)
The produced hot melt adhesive was applied to a thickness of 50 μm on a 50 μm thick polyethylene terephthalate (PET) film, and was formed to have a width of 25 mm in the parallel direction (MD) with respect to the substrate progress. A polyethylene (PE) film was placed on the PET film on which the hot melt adhesive was molded so that the hot melt adhesive was in contact. Thereafter, the PET film and the PE film were pasted together at a speed of 300 mm / min using a 2 kg roller, and then allowed to stand at room temperature for 24 hours. The bonded state was used as a test body. Then, three test pieces were prepared for each hot melt adhesive. And the intensity | strength when peeling off this test body by the speed of 300 mm / min in 10 degreeC atmosphere was measured. This strength was measured for three test specimens, and the average value of the three measured values was calculated. The average value was taken as the low temperature adhesive strength, and the strength under the low temperature condition was evaluated. If this low-temperature adhesive strength is 15 N / 25 mm or more, it is evaluated as "◎", and if 10 N / 25 mm or more and less than 15 N / 25 mm, it is evaluated as "○". If it is less than 10 N / 25 mm, "×" It was evaluated.

(Wet adhesion: wet adhesion strength)
After melting the produced hot melt adhesive by heating to 150 ° C., the melted hot melt adhesive is spiral sprayed to 5 gsm (g / m ² ) on one side of the non-woven fabric As it was applied. One second after the application, the tissue was placed on the non-woven fabric coated with the hot melt adhesive so that the hot melt adhesive was in contact. Thereafter, the non-woven fabric and the tissue were pressed at 23 ° C. under a pressure of 50 gf / cm ² for 0.01 second. The laminate was cut at 25 mm in the direction perpendicular to the substrate (CD) to obtain a strip-shaped test piece. Then, after immersing the test piece in tap water at 23 ° C. for 5 to 6 seconds, the test piece was taken out of the water and wiped off the water to obtain a wet test body. Then, three test pieces were prepared for each hot melt adhesive. And the T-type peeling test based on JISK6845 was done to this test body. Specifically, the strength when this test body was peeled at a tensile speed of 100 mm / min was measured. This peeling test was performed at 23 ° C. and 65% RH.

  Moreover, as a result of conducting this peeling test, when a tissue is totally torn, it evaluates as "(double-circle)", When a tissue is partially torn, it evaluates as "(circle)", When a tissue is not broken Was rated as "x".

(Compatibility)
The state where the produced hot melt adhesive was heated and melted at 160 ° C. was visually confirmed. When white turbidity could not be confirmed, it evaluated as "(circle)", and when white turbidity could be confirmed, it evaluated as "x".

  Each evaluation result is shown in Table 1 with the compounding quantity of a hot melt adhesive.

  As can be seen from Table 1, in the case of a hot melt adhesive comprising a thermoplastic polymer, a tackifier, and a softener, the softener comprising an acid-modified oil modified with maleic acid (Examples 1 to 7) ) Was superior in adhesion under low temperature conditions, adhesion in the wet state, and compatibility, as compared with the case (Comparative Examples 1 to 5) otherwise. Moreover, although it was excellent in compatibility, although Examples 1-7 contain acid-modified oil and it was the above melt viscosity, it turned out that it is excellent also in coatability.

  In addition, the hot melt adhesive according to Examples 1 to 7 had high wet adhesive strength as compared with the case where the softening agent modified with maleic acid was not contained (Comparative Examples 1 and 5). Since the hot melt adhesives according to Comparative Examples 1 and 5 do not contain a softening agent modified with maleic acid, although the problems with compatibility hardly occur, the wet adhesive strength could not be enhanced.

  Further, in the case where the wax modified with maleic acid was contained (Comparative Example 2) or in the case where the liquid rubber modified with maleic acid was contained (Comparative Example 4), the compatibility decreased. In addition, when the thermoplastic polymer modified with maleic acid was included (Comparative Example 3), the compatibility decreased, and further, the low temperature adhesive strength could not be enhanced.

  From these facts, it was found that the inclusion of the maleic acid-modified softener provides a hot melt adhesive having excellent coatability and sufficiently high low-temperature adhesive strength and wet adhesive strength.

  In Example 1, about 0.16 parts by mass of acid-modified oil is contained with respect to 100 parts by mass of the lubricant. In Example 2, about 5.26 parts by mass of acid-modified oil is contained with respect to 100 parts by mass of the lubricant. From the comparison between Example 1 and Example 2, it is understood that the content of the acid-modified oil is preferably 0.3 parts by mass or more with respect to 100 parts by mass of the lubricant. In Example 4, about 21.74 parts by mass of the acid-modified oil is contained with respect to 100 parts by mass of the lubricant. In Example 5, about 55.56 parts by mass of acid-modified oil is contained with respect to 100 parts by mass of the lubricant. From the comparison between Example 3 and Example 4, it is understood that the content of the acid-modified oil is preferably 55 parts by mass or less with respect to 100 parts by mass of the lubricant.

  This application is based on Japanese Patent Application No. 2016-204292 filed on October 18, 2016, the contents of which are included in the present application.

  Although the present invention has been described appropriately and sufficiently through the embodiments to express the present invention above, it is easy for those skilled in the art to change and / or improve the above embodiments. It should be recognized. Therefore, unless a change or improvement implemented by a person skilled in the art is at a level that deviates from the scope of the claims set forth in the claims, the change or the improvement is the scope of the rights of the claim It is interpreted as being included in

  ADVANTAGE OF THE INVENTION According to this invention, the hot-melt adhesive excellent in the adhesiveness in a wet state, coating property, and adhesiveness under low temperature conditions can be provided.

Claims (8)

A thermoplastic polymer, a tackifier, and a softener,
The hot-melt adhesive, wherein the softener comprises an acid-modified oil modified with at least one of a carboxylic acid and a carboxylic acid anhydride. The carboxylic acid is maleic acid,
The hot melt adhesive according to claim 1, wherein the carboxylic acid anhydride is maleic acid anhydride.   The hot melt adhesive according to claim 1 or 2, wherein the acid modified oil is an oil having a succinic acid skeleton in the molecule.   The hot melt adhesive according to any one of claims 1 to 3, wherein the content of the acid-modified oil is 0.02 to 100 parts by mass with respect to 100 parts by mass of the softener.   5. The acid-modified oil according to claim 1, wherein the oil before the modification is at least one selected from the group consisting of paraffinic oil, naphthenic oil, and aromatic oil. Hot melt adhesive.   The hot melt adhesive according to any one of claims 1 to 5, wherein the thermoplastic polymer is a copolymer of a conjugated diene compound and a vinyl aromatic hydrocarbon, or an olefin polymer.   The copolymer is at least one selected from the group consisting of styrene-butadiene block copolymer, styrene-isoprene block copolymer, hydrogenated styrene-butadiene block copolymer, and hydrogenated styrene-isoprene block copolymer. The hot melt adhesive according to Item 6.   The hot melt adhesive according to claim 6, wherein the olefin-based polymer is a poly α-olefin polymer.