Adhesive for polyvinyl chloride resin and adhesive structure

Abstract

To provide a highly versatile adhesive for polyvinyl chloride resin having superior adhesion to members including polyvinyl chloride resin.SOLUTION: An adhesive for polyvinyl chloride resin comprises a halogen-containing polyether polyol (A), a halogen-free polyol (B), and a polyisocyanate (C), wherein the halogen-containing polyether polyol (A) is a polyether polyol represented by the following formula (1) and having a number-average molecular weight of 400 to 10,000, and the halogen-free polyol (B) is a polyol having a number-average molecular weight of 400 or more and containing no halogen atom. (Q represents a polymer component containing a cyclic ether structural unit derived from the ring opening of epihalohydrin; m is an integer of 2 to 3; and R1 represents a residue of an active hydrogen-containing compound.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to an adhesive for vinyl chloride resin and an adhesive structure. [Background technology]

[0002] PVC resin has excellent water resistance, flame retardancy, and mechanical properties, and is relatively inexpensive. Therefore, PVC resin-containing materials are widely used in piping, building materials, wallpaper, window frames, medical equipment, and more. Furthermore, because PVC resin-containing materials have excellent conformability, they can be used in flooring, wallpaper, hoses and tubes, electrical wire coatings, agricultural films, synthetic leather, decorative sheets, and more.

[0003] A member containing vinyl chloride resin may be used by adhering it to another member with an adhesive, etc. For example, in the case of flooring, a sheet containing vinyl chloride resin is used for at least one of the surface sheet, the internal sheet, and the back sheet, and an adhesive composite formed by bonding the sheets together with an adhesive is widely used.

[0004] Various methods are known for bonding an article containing vinyl chloride resin to another member. For example, there is a method in which a moisture-curing adhesive that cures with moisture in the air is applied to the surface of the article, and then an adhesive polymer emulsion is applied to the coated surface to bond it to another article (see Patent Document 1). This document states that this method can increase adhesive strength. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-354914 Summary of the Invention [Problem to be solved by the invention]

[0006] In the above method, the adhesive layer is made up of two layers, one of which is a moisture-curing adhesive and the other is an adhesive polymer emulsion, which places a heavy burden on the worker. Furthermore, moisture-curing adhesives can have their degree of cure affected by humidity fluctuations during use, which can affect adhesion, and they can be difficult to cure deep into the adhesive when applied in a thick film, which can limit the conditions under which they can be used.

[0007] Therefore, one aspect of the present invention is directed to providing a versatile adhesive for vinyl chloride resin that has excellent adhesion to members containing vinyl chloride resin. [Means for solving the problem]

[0008] The present invention includes, for example, the following inventions. [1] An adhesive for vinyl chloride resin for bonding members containing vinyl chloride resin, A composition comprising a halogen-containing polyether polyol (A), a halogen-free polyol (B), and a polyisocyanate (C), The halogen-containing polyether polyol (A) is a polyether polyol represented by the following formula (1) and having a number average molecular weight of 400 to 10,000: The adhesive for vinyl chloride resin, wherein the halogen-free polyol (B) is a polyol having a number average molecular weight of 400 or more and containing no halogen atoms.

[0009] [ka]

[0010] (In the above formula (1), Q represents a polymer component containing the following structural unit [I], m represents an integer of 2 to 3, R 1 represents a residue of an active hydrogen-containing compound.

[0011] [ka]

[0012] (In the structural unit [I], X represents a halogen atom.) [2] The adhesive for vinyl chloride resin according to [1], which contains as a crosslinking agent (D) a compound having a number average molecular weight of less than 400 and having two or more hydroxyl groups in the molecule. [3] The adhesive for vinyl chloride resins according to [1] or [2], wherein the halogen-containing polyether polyol (A) is contained in an amount of 3 to 40 mass % based on the total amount of the adhesive for vinyl chloride resins. [4] The adhesive for vinyl chloride resins according to any one of [1] to [3], wherein the halogen-free polyol (B) has a hydroxyl value of 10 to 500 mgKOH / g. [5] The adhesive for vinyl chloride resins according to any one of [1] to [4], wherein the halogen-free polyol (B) is contained in an amount of 3 to 40 mass % based on the total amount of the adhesive for vinyl chloride resins. [6] The adhesive for vinyl chloride resins according to [2], wherein the crosslinking agent (D) is contained in an amount of 1 to 10 mass % relative to the total amount of the adhesive for vinyl chloride resins, and the crosslinking agent (D) comprises a compound having two hydroxyl groups in the molecule and a compound having three hydroxyl groups in the molecule. [7] The adhesive for vinyl chloride resin according to any one of [1] to [6], wherein the polyisocyanate (C) is at least one of an aromatic polyisocyanate compound and a reaction product of an aromatic polyisocyanate compound with a polyol compound. [8] An adhesive structure in which two or more members are bonded together via an adhesive layer, at least one of the members containing a vinyl chloride resin, and the adhesive layer is a cured product of the adhesive for vinyl chloride resin described in any one of [1] to [7]. [9] The bonded structure according to [8], wherein the mating member to be bonded to the member containing the vinyl chloride resin is a resin member having a fibrous surface. [Effects of the Invention]

[0013] According to one aspect of the present invention, it is possible to provide a highly versatile adhesive for vinyl chloride resin that has excellent adhesion to members containing vinyl chloride resin, and an adhesive structure. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, exemplary embodiments for carrying out the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[0015] <<Adhesive for vinyl chloride resin>> An adhesive for vinyl chloride resin according to one aspect of the present invention comprises: An adhesive for vinyl chloride resin for bonding a member containing vinyl chloride resin to another member, A composition comprising a halogen-containing polyether polyol (A), a halogen-free polyol (B), and a polyisocyanate (C), The halogen-containing polyether polyol (A) is a polyether polyol represented by the following formula (1) and having a number average molecular weight of 400 to 10,000: The halogen-free polyol (B) is a polyol having a number average molecular weight of 400 or more and containing no halogen atoms.

[0016] [ka]

[0017] (In formula (1), Q represents a polymer component containing the following structural unit [I], m represents an integer of 2 to 3, R 1 represents a residue of an active hydrogen-containing compound.

[0018] [ka]

[0019] (In the structural unit [I], X represents a halogen atom.) <<Halogen-containing polyether polyol>> In formula [I], the halogen atom represented by X is not particularly limited, and examples thereof include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom, a chlorine atom, and a bromine atom are preferred from the viewpoint of ease of handling, and a fluorine atom or a chlorine atom is more preferred from the viewpoint of thermal and chemical stability.

[0020] In formula (1), Q may be a polymer component composed only of structural units represented by formula [I].

[0021] In the above formula (1), Q is A structural unit represented by formula [I], The polymer component may contain a structural unit represented by formula [II].

[0022] [ka]

[0023] In the formula [II], A represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

[0024] In the above formula [II], the hydrogen atom or hydrocarbon having 1 to 10 carbon atoms represented by A is not particularly limited, and examples thereof include a hydrogen atom, a methyl group, an ethyl group, a vinyl group, an n-propyl group, an isopropyl group, a cyclopropyl group, an allyl group, an n-butyl group, an isobutyl group, a t-butyl group, a cyclobutyl group, an n-pentyl group, a neopentyl group, a cyclopentyl group, an n-hexyl group, a cyclohexyl group, a phenyl group, a heptyl group, a cycloheptyl group, an octyl group, a cyclooctyl group, a nonyl group, a cyclononyl group, and a decyl group. Among these, in terms of ease of availability of precursors, a hydrogen atom, a methyl group, and an ethyl group are preferred, and a hydrogen atom or a methyl group is more preferred.

[0025] In formula (1), when Q is a polymer component containing a structural unit represented by formula [I] and a structural unit represented by formula [II], the arrangement of the structural units may be block or random.

[0026] In formula (1), R 1 The active hydrogen-containing compound residue represented by the formula (I) is not particularly limited, but examples thereof include a hydroxyl residue, an amine residue, a carboxylic acid residue, and a thiol residue.

[0027] The active hydrogen-containing compound containing such an active hydrogen-containing compound residue is not particularly limited, but examples thereof include hydroxy compounds, amine compounds, carboxylic acid compounds, thiol compounds, and polyether polyols having a hydroxyl group.

[0028] Examples of hydroxy compounds include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,6-hexanediol, 1,9-nonanediol, 2,5-hexanediol, 1,3-cyclohexanediol, 2-methylpentane-2,4-diol, 2,5-dimethyl-2,5-hexanediol, glycerin, trimethylolpropane, hexanetriol, pentaerythritol, diglycerin, sorbitol, sucrose, glucose, 2-naphthol, and bisphenol.

[0029] Examples of the amine compound include ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, and 1,2-butylenediamine.

[0030] Examples of the carboxylic acid compound include phthalic acid and adipic acid.

[0031] Examples of the thiol compound include ethanedithiol and butanedithiol.

[0032] Examples of polyether polyols having a hydroxyl group include polyether polyols having a molecular weight of 200 or more and 2,000 or less.

[0033] Among these active hydrogen-containing compounds, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,9-nonanediol, 2,5-hexanediol, 2-methylpentane-2,4-diol, ethylenediamine, and polyether polyols having a molecular weight of 200 or more and 2,000 or less are preferred, as they enable efficient production of halogen-containing polyether polyols, and tripropylene glycol, 2,5-hexanediol, 1,9-nonanediol, and polyether polyols having a molecular weight of 200 or more and 1,000 or less (e.g., polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc.) are particularly preferred.

[0034] The number average molecular weight of the halogen-containing polyether polyol is 400 to 10,000, and is preferably 400 to 5,000, particularly preferably 1,000 to 5,000, because this provides excellent handling properties and adhesion to members containing vinyl chloride resin.

[0035] The ratio of the mass average molecular weight Mw of the halogen-containing polyether polyol to the number average molecular weight Mn (Mw / Mn) is preferably 2.00 or less, particularly preferably 1.50 or less, in order to improve the curability of the resulting adhesive cured product, where Mn is the number average molecular weight determined by gel permeation chromatography measurement using polystyrene as the standard substance, and Mw is the mass average molecular weight.

[0036] The primary conversion rate of terminal hydroxyl groups in the halogen-containing polyether polyol is not particularly limited, but is preferably less than 10%, more preferably 8% or less, and particularly preferably 5% or less, because this results in small variations in reactivity, a uniform reaction, and tends to result in a uniform molecular weight distribution and composition of the resulting polyurethane.

[0037] <<Halogen-free polyol>> The halogen-free polyol (B) is not particularly limited as long as it is a polyol compound that does not have halogen atoms in the molecule, has two or more hydroxyl groups, and has a number average molecular weight of 400 or more. Examples include polyether polyols obtained by ring-opening polymerization of alkylene oxides, polymer polyols obtained by radical polymerization of vinyl monomers in polyether polyols, polyester polyols obtained by polycondensation of polyhydric alcohols and polycarboxylic acids, polyesteramide polyols obtained by polycondensation of polyhydric alcohols, polycarboxylic acids, and amino alcohols, polylactone polyols obtained by ring-opening polymerization of lactones, polycarbonate polyols obtained by polycondensation of polyhydric alcohols and carbonates, acrylic polyols, polybutadiene polyols and hydrogenated products thereof, polyisoprene polyols and hydrogenated products thereof, partially saponified ethylene-vinyl acetate copolymers, and natural oil-based polyols such as soybean oil and castor oil. As the halogen-free polyol (B), polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. are preferred from the viewpoints of handling and adhesiveness.

[0038] The hydroxyl value of the halogen-free polyol (B) is not particularly limited, but can be, for example, in the range of 1 to 1000 mgKOH / g. From the viewpoints of handleability and curability, the hydroxyl value of the halogen-free polyol (B) is preferably in the range of 10 to 500 mgKOH / g, more preferably in the range of 12 to 300 mgKOH / g, and even more preferably in the range of 20 to 250 mgKOH / g.

[0039] <<Polyisocyanate>> The polyisocyanate is not particularly limited as long as it is a compound having two or more isocyanate groups in the molecule, and examples thereof include aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds (monocyclic alicyclic polyisocyanate compounds, crosslinked cyclic alicyclic polyisocyanate compounds), and polyisocyanate derivatives thereof.

[0040] Examples of aromatic polyisocyanate compounds include tolylene diisocyanate (2,4- or 2,6-tolylene diisocyanate, or a mixture thereof) (TDI), phenylene diisocyanate (m- or p-phenylene diisocyanate, or a mixture thereof), 4,4'-diphenyl diisocyanate, diphenylmethane diisocyanate (4,4'-, 2,4'-, or 2,2'-diphenylmethane diisocyanate, or a mixture thereof) (MDI), 4,4'-toluidine diisocyanate (TODI), 4,4'-diphenyl ether diisocyanate, xylylene diisocyanate (1,3- or 1,4-xylylene diisocyanate, or a mixture thereof) (XDI), tetramethylxylylene Examples of the diisocyanate include diisocyanate (1,3- or 1,4-tetramethylxylylene diisocyanate, or a mixture thereof) (TMXDI), ω,ω'-diisocyanato-1,4-diethylbenzene, naphthalene diisocyanate (1,5-, 1,4-, or 1,8-naphthalene diisocyanate, or a mixture thereof) (NDI), triphenylmethane triisocyanate, tris(isocyanatophenyl)thiophosphate, polymethylene polyphenylene polyisocyanate, nitrodiphenyl-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, and 3,3'-dimethoxydiphenyl-4,4'-diisocyanate.

[0041] Examples of the aliphatic polyisocyanate compound include trimethylene diisocyanate, 1,2-propylene diisocyanate, butylene diisocyanate (tetramethylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate), hexamethylene diisocyanate, pentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanate methylcaprate, lysine diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, trimethylhexamethylene diisocyanate, and decamethylene diisocyanate.

[0042] Examples of monocyclic alicyclic polyisocyanate compounds include 1,3-cyclopentane diisocyanate, 1,3-cyclopentene diisocyanate, cyclohexane diisocyanate (1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate), 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), methylenebis(cyclohexyl isocyanate) (4,4'-, 2,4'-, or 2,2'-methylenebis(cyclohexyl isocyanate), or combinations thereof. Examples of suitable diisocyanates include methyl 2,4-cyclohexane diisocyanate, methyl 2,6-cyclohexane diisocyanate, bis(isocyanatomethyl)cyclohexane (1,3- or 1,4-bis(isocyanatomethyl)cyclohexane, or a mixture thereof) (hydrogenated XDI), dimer acid diisocyanate, trans cyclohexane 1,4-diisocyanate, hydrogenated tolylene diisocyanate (hydrogenated TDI), and hydrogenated tetramethylxylylene diisocyanate (hydrogenated TMXDI).

[0043] Examples of the crosslinked cyclic alicyclic polyisocyanate compound include norbornene diisocyanate, norbornane diisocyanate methyl, bicycloheptane triisocyanate, diisocyanatomethyl bicycloheptane, and di(diisocyanatomethyl)tricyclodecane.

[0044] Furthermore, examples of derivatives of these polyisocyanates include multimers of the above polyisocyanate compounds (dimers, trimers, pentamers, heptamers, uretidinedione, ureitonimine, isocyanurate-modified products, polycarbodiimides, etc.), urethane-modified products (for example, urethane-modified products in which part of the isocyanate groups in the above polyisocyanate compounds or multimers have been modified or reacted with a monool compound or a polyol compound), biuret-modified products (for example, biuret-modified products produced by the reaction of the above polyisocyanate compounds with water), allophanate-modified products (for example, allophanate-modified products produced by the reaction of the above polyisocyanate compounds with a monool compound or a polyol compound), urea-modified products (for example, urea-modified products produced by the reaction of the above polyisocyanate compounds with diamines), and oxadiazinetriones (for example, oxadiazinetriones produced by the reaction of the above polyisocyanate compounds with carbon dioxide, etc.).

[0045] The polyisocyanate is particularly preferably at least one of an aromatic polyisocyanate compound and a reaction product of an aromatic polyisocyanate compound with a polyol compound (hereinafter also referred to as a prepolymer), because the cured product of the adhesive is expected to have excellent toughness and improved adhesion. When the prepolymer is mixed with a polyol or polyisocyanate to form a composition, it reacts with them, and the polyol or polyisocyanate that reacts with the prepolymer may be the same as or different from the polyol or polyisocyanate used to form the prepolymer.

[0046] The above polyisocyanate compounds or derivatives thereof may be used alone or in combination of two or more.

[0047] <<Method of manufacturing halogen-containing polyether polyol>> The method for producing the halogen-containing polyether polyol is not particularly limited, and it can be produced by a conventionally known production method.

[0048] Examples of such methods include (A) a method in which a halogen-containing alkylene oxide is added to a bifunctional or higher functional active hydrogen compound using a Lewis acid catalyst or a composite metal cyanide complex catalyst to a predetermined molecular weight; and (B) a method in which a halogen-containing alkylene oxide is ring-opened in the presence of a bifunctional or higher functional active hydrogen-containing compound, an onium salt catalyst such as a phosphazenium salt, an ammonium salt, or a phosphonium salt, and a Lewis acid catalyst.

[0049] Examples of Lewis acid catalysts include aluminum compounds, zinc compounds, boron compounds, etc. Among these, organoaluminum, aluminoxane, and organozinc are preferred, with organoaluminum being particularly preferred, as they provide catalysts for producing halogen-containing polyether polyols with excellent catalytic performance.

[0050] It is preferable to produce a halogen-containing polyether polyol by ring-opening polymerization of the halogen-containing alkylene oxide described in (B), because it is easy to obtain a halogen-containing polyalkylene oxide having a low degree of unsaturation and a narrow molecular weight distribution, which improves the handleability when used as an adhesive, and the resulting adhesive tends to have excellent curing properties.

[0051] The structure of the phosphazenium salt used in producing the halogen-containing polyether polyol is not particularly limited.

[0052] The phosphazenium salt is, for example, a phosphazenium salt represented by formula (2):

[0053] [ka]

[0054] In formula (2), R 2 and R 3 are each independently hydrogen atoms, a hydrocarbon group having 1 to 20 carbon atoms, R 2 and R 3 and a ring structure in which they are bonded to each other; R 2 Comrades or R 3 represents a ring structure in which rings are bonded to each other; Z - represents a hydroxy anion, an alkoxy anion having 1 to 4 carbon atoms, a carboxy anion, an alkylcarboxy anion having 2 to 5 carbon atoms, a chloride anion, a bromide anion, an iodide anion, or a hydrogen carbonate anion; Y represents a carbon atom or a phosphorus atom; a is 2 when Y is a carbon atom, When Y is a phosphorus atom, the number is 3.

[0055] In formula (2), R 2 , R 3 The hydrocarbon group having 1 to 20 carbon atoms represented by the formula (I) is preferably a methyl group, an ethyl group, or an isopropyl group, in view of providing an alkylene oxide polymerization catalyst with excellent catalytic activity and easy availability of the raw material.

[0056] As the phosphazenium salt represented by formula (2), tetrakis(1,1,3,3-tetramethylguanidinophosphonium hydroxide, tetrakis(1,1,3,3-tetramethylguanidino)phosphonium hydrogen carbonate, and tetrakis[tris(dimethylamino)phosphoranylideneamino]phosphonium hydroxide are particularly preferred, since they serve as catalysts for producing halogen-containing polyether polyols with excellent catalytic performance.

[0057] The structure of the ammonium salt or phosphonium salt is represented by formula (3):

[0058] [ka]

[0059] In formula (3), D represents a nitrogen atom or a phosphorus atom; R 4 , R 5 , R 6 and R 7 are each independently an alkyl group, an aryl group, an alkoxy group, or a dialkylamino group having 1 to 20 carbon atoms; a halogen atom, or represents a hydrogen atom; E - represents a counterion consisting of an inorganic or organic group; R 4 ~R 7 Two to four of these may be bonded to form a cyclic structure, and the cyclic structure may contain a heteroatom.

[0060] As the ammonium salt or phosphonium salt represented by formula (3), tetra-normal-octylammonium chloride, tetra-normal-octylammonium bromide, and tetra-normal-butylphosphonium bromide are preferably used, since they are catalysts for producing halogen-containing polyether polyols with excellent catalytic activity.

[0061] The polymerization temperature when producing the halogen-containing polyether polyol is not particularly limited, but is preferably in the range of 70 to 150°C, more preferably in the range of 90 to 110°C, because the polyalkylene oxide is less likely to decompose and the molecular weight distribution is less likely to broaden, and catalytic activity is more likely to be exhibited.

[0062] In the method for producing a halogen-containing polyether polyol, the polymerization reaction is preferably carried out without a solvent, but can also be carried out in a solvent, such as benzene, toluene, xylene, cyclohexane, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, 1,4-dioxane, 1,2-dimethoxyethane, methyl ethyl ketone, ethyl acetate, or butyl acetate.

[0063] <<Other ingredients>> If necessary, crosslinking agents, urethanization catalysts, foaming agents, foam stabilizers, etc. can be added to the vinyl chloride resin adhesive, and among these, the addition of crosslinking agents and urethanization catalysts is preferred because they allow for the efficient production of a cured adhesive. The order of mixing these agents when used is not particularly limited and can be selected as appropriate.

[0064] The crosslinking agent may be any low molecular weight compound having two or more active hydrogen groups in the molecule. Examples of the crosslinking agent include diols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, 1,9-nonanediol, and hydroquinone diethylol ether; triols such as trimethylolpropane; pentaerythritol; diamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, cyclohexylenediamine, piperazine, tolylenediamine, 4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane, xylylenediamine, hydrogenated 4,4'-diaminodiphenylmethane, hydrogenated xylylenediamine, isophoronediamine, and norbornanediamine, and mixtures of two or more thereof. As the crosslinking agent, a compound having a number average molecular weight of 90 or more and less than 400 and having two or more hydroxyl groups in the molecule is preferred, and from the viewpoints of handleability and adhesiveness, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, trimethylolpropane, and pentaerythritol are more preferred.

[0065] As the urethanization catalyst, known urethanization catalysts can be used. Examples include tertiary amine compounds, organometallic compounds, etc. In applications where environmental impact is important, it is preferable that the vinyl chloride resin adhesive does not contain a catalyst.

[0066] The tertiary amine compound is not particularly limited, but examples thereof include triethylamine, triethylenediamine, N,N-dimethylbenzylamine, N-methylmorpholine, diazabicycloundecene (also known as DBU), etc. These can be used alone or in combination of two or more.

[0067] The organometallic compound is not particularly limited, but examples thereof include tin-based compounds and non-tin-based compounds, and dibutyltin dilaurate (also known as DBTDL), dioctyltin dilaurate (also known as DOTDL), tin 2-ethylhexanoate, etc. are preferred in terms of reactivity and hygiene.

[0068] The above catalysts such as tertiary amine compounds and organometallic compounds can be used alone or in combination of two or more kinds.

[0069] Furthermore, the polyurethane adhesive may contain additives such as fillers, pigments, antioxidants, etc. The fillers include inorganic fillers and organic fillers.

[0070] Examples of inorganic fillers include silica, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate, calcium carbonate, zinc carbonate, barium carbonate, dawsonite, hydrotalcite, calcium sulfate, barium sulfate, calcium silicate, talc, clay, mica, montmorillonite, bentonite, sepiolite, imogolite, sericite, glass fiber, glass beads, silica-based balun, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balun, zinc borate, various magnetic powders, zeolite, etc. Talc and zeolite are preferred as inorganic fillers because they provide excellent mechanical strength to the cured adhesive.

[0071] Examples of organic fillers include synthetic organic fine particles such as polystyrene, polyacrylonitrile, polymethyl methacrylate, polypropylene, polyethylene, polyvinyl chloride, and polyurethane, and natural organic fine particles such as wood powder, bamboo powder, sawdust, paper pulp, and wood refined cellulose powder obtained from paper pulp.

[0072] The vinyl chloride resin adhesive may contain a solvent from the viewpoints of handling, coating, etc. In this case, examples of the solvent include benzene, toluene, xylene, cyclohexane, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, 1,4-dioxane, 1,2-dimethoxyethane, methyl ethyl ketone, ethyl acetate, butyl acetate, etc. In the case of thick film applications where a large amount of residual solvent is likely to remain, it is preferable that the vinyl chloride resin adhesive does not contain a solvent.

[0073] <<Mixing ratio of each ingredient>> The adhesive for vinyl chloride resin according to one embodiment of the present invention has excellent adhesion to members containing vinyl chloride resin, and is therefore preferably formulated in the following ratio.

[0074] The adhesive for vinyl chloride resins according to one embodiment of the present invention preferably contains 3 to 40 mass % of the halogen-containing polyether polyol (A) relative to the total mass of the adhesive for vinyl chloride resins, and more preferably 3 to 35 mass %. In this specification, when the adhesive for vinyl chloride resins contains a solvent, the "total mass of the adhesive for vinyl chloride resins" means the total mass of the solids excluding the solvent.

[0075] The adhesive for vinyl chloride resins according to one embodiment of the present invention preferably contains 3 to 40 mass % of the halogen-free polyol (B) relative to the total amount of the adhesive for vinyl chloride resins, and more preferably 3 to 35 mass %.

[0076] The adhesive for vinyl chloride resins according to one embodiment of the present invention preferably contains 10 to 40 mass % of polyisocyanate (C) relative to the total amount of the adhesive for vinyl chloride resins, more preferably 15 to 40 mass %, and even more preferably 20 to 40 mass %.

[0077] A vinyl chloride resin adhesive according to one embodiment of the present invention preferably contains 1 to 10 mass % of crosslinking agent (D) relative to the total amount of the vinyl chloride resin adhesive, more preferably 1 to 8 mass %, and even more preferably 1 to 5 mass %. From the viewpoint of improving crosslink density, a vinyl chloride resin adhesive according to one embodiment of the present invention particularly preferably contains 1 to 10 mass % of crosslinking agent (D) relative to the total amount of the vinyl chloride resin adhesive, and includes, as crosslinking agent (D), a compound having two hydroxyl groups in the molecule and a compound having three hydroxyl groups in the molecule.

[0078] From the viewpoint of improving the mechanical strength of the adhesive cured product, the vinyl chloride resin adhesive according to one embodiment of the present invention preferably contains a filler in an amount of 10 to 50 mass %, and more preferably 20 to 40 mass %, based on the total amount of the vinyl chloride resin adhesive. Furthermore, the vinyl chloride resin adhesive according to one embodiment of the present invention further preferably contains zeolite and other inorganic fillers as fillers in an amount of 10 to 50 mass %, and even more preferably 20 to 40 mass %, based on the total amount of the vinyl chloride resin adhesive.

[0079] <<Isocyanate group concentration equivalent ratio>> The adhesive for vinyl chloride resins may contain a halogen-containing polyether polyol, a halogen-free polyol, and a polyisocyanate in any ratio, but in order to obtain a particularly excellent adhesive for vinyl chloride resins, it is preferable that the equivalent ratio of the isocyanate group concentration in the polyisocyanate to the total active hydrogen group concentration in the polyol is in the range of 0.9 to 3.5, and more preferably in the range of 0.9 to 3.0.

[0080] <<Adhesive structure>> A bonded structure according to one embodiment of the present invention is a bonded structure in which two or more members are bonded together via an adhesive layer. At least one of the two or more members is a member containing a vinyl chloride resin. The adhesive layer is a cured product of the above-mentioned adhesive for vinyl chloride resin (hereinafter also referred to as an adhesive cured product).

[0081] Examples of components containing vinyl chloride resin include components made of vinyl chloride resin, components made of polymer alloys obtained by mixing vinyl chloride resin with other resins, and components made of vinyl chloride resin or the above-mentioned polymer alloys mixed with other additives (e.g., plasticizers, antioxidants, etc.). Components made of vinyl chloride resin are preferred because they are expected to improve adhesion due to interactions with polar sites (hydroxyl groups and halogen element sites) in the adhesive.

[0082] The mating member to be adhered to the member containing vinyl chloride resin may be a member containing vinyl chloride resin or a member not containing vinyl chloride resin. Examples of materials for members not containing vinyl chloride resin include resins such as PET, ABS, PC, nylon, and polyamide, and metals such as aluminum and steel plate. The member not containing vinyl chloride resin is preferably a resin member having a fibrous surface or a protruding surface, as this is expected to improve adhesion due to an increased contact area with the adhesive. In the case of application to synthetic leather, a resin member having a fibrous surface is preferred.

[0083] The shape of the member can be freely selected, for example, from a sheet, a cylinder, a plate, or the like.

[0084] The reaction temperature and reaction time when forming a cured adhesive may be set appropriately depending on the purpose, with a reaction temperature of 20 to 220°C and a reaction time of 1 minute to 2 weeks being preferred, and when used to bond resin sheets together, a reaction temperature of 20 to 120°C and a reaction time of 12 hours to 1 week being preferred.

[0085] The coating method for forming a cured adhesive product is not particularly limited, and can be, for example, coating with a spatula, comb, roller, trowel, rake, applicator, bar coater, etc., or extrusion or spray with a sealing gun, or by hand or machine coating, to form a coating film of any thickness, film sheet, thick product, or any other shape. Also, a compound having anti-sagging properties can be incorporated and applied to vertical surfaces, wall surfaces, curved surfaces, depressions, etc. with a roller, lysine gun, airless gun, etc. to form a coating film or cured product.

[0086] The method for applying the vinyl chloride resin adhesive is not particularly limited, but examples include a method in which the adhesive is applied directly to a cleaned substrate, dried as necessary, and then bonded to an adherend to be cured.

[0087] Specific uses of the vinyl chloride resin adhesive according to one embodiment of the present invention are not particularly limited, but examples include adhesives for flexible packaging, adhesives for civil engineering and construction, rock consolidation agents, floor adhesives, adhesives for vehicles, elastic adhesives, structural adhesives, and adhesives for synthetic leather. [Example]

[0088] The present invention will be described below with reference to examples, but the examples do not limit the present invention in any way. The raw materials and evaluation methods used in the following examples and comparative examples are as follows.

[0089] <Halogen-containing polyether polyol (A)> The following halogen-containing polyether polyols A1 to A3 having the structure shown in formula (4) were used.

[0090] [ka]

[0091] (In formula (4), X is a chlorine atom and m is 2.) Halogen-containing polyether polyol A1 (number average molecular weight: 500, active hydrogen-containing compound residue R 1 : Polypropylene glycol (PPG) structure with number average molecular weight of 150, viscosity: 2000 mPa·s). Halogen-containing polyether polyol A2 (number average molecular weight: 1,500, active hydrogen-containing compound residue R 1 : PPG structure with number average molecular weight of 400, viscosity: 9,000 mPa·s). Halogen-containing polyether polyol A3 (number average molecular weight: 4,000, active hydrogen-containing compound residue R 1 : PPG structure with number average molecular weight of 1000, viscosity: 100,000 mPa·s).

[0092] <Halogen-free polyol (B)> Halogen-free polyol B1 (number of hydroxyl groups in the molecule: 2, hydroxyl value: 56 mg KOH / g, number average molecular weight: 2,000, main chain structure: PPG). Halogen-free polyol B2 (number of hydroxyl groups in the molecule: 2, hydroxyl value: 14 mg KOH / g, number average molecular weight: 8,000, main chain structure: PPG). Halogen-free polyol B3 (number of hydroxyl groups in the molecule: 2, hydroxyl value: 280 mg KOH / g, number average molecular weight: 400, main chain structure: PPG). Halogen-free polyol B4 (number of hydroxyl groups in the molecule: 3, hydroxyl value: 168 mg KOH / g, number average molecular weight: 1,000, main chain structure: PPG). Halogen-free polyol B5 (number of hydroxyl groups in the molecule: 2, hydroxyl value: 56 mg KOH / g, number average molecular weight: 2,000, main chain structure: polyester polyol). Halogen-free polyol B6 (number of hydroxyl groups in the molecule: 2, hydroxyl value: 56 mg KOH / g, number average molecular weight: 2,000, main chain structure: polycarbonate diol).

[0093] <Polyisocyanate (C)> Polyisocyanate C1 (4,4'-MDI, manufactured by Tosoh Corporation, Millionate MT). Polyisocyanate C2 (2,4-4,4'-MDI, manufactured by Tosoh Corporation, Millionate NM). Polyisocyanate C3 (reaction product of B1 (400 g) above) with C1 (100 g)).

[0094] <Crosslinking agent (D)> Crosslinker D1 (trimethylolpropane, Fujifilm Wako Pure Chemical Industries, Ltd.). Crosslinker D2 (1,4-butanediol, Fujifilm Wako Pure Chemical Industries, Ltd.).

[0095] <Filler (E)> Filler E1 (talc, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). Filler E2 (zeolite, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0096] <Preparation of adhesive> The above raw materials were charged into a sample bottle in the ratios (mass %) shown in Table 1, and the adhesive was prepared by stirring in a stirring / degassing mixer until homogenous.

[0097] <Adhesion evaluation by shear peel test (adhesion strength with PVC substrate)> Each of the above adhesives was applied to the surface of a vinyl chloride sheet (hereinafter also referred to as PVC substrate) and a vinyl chloride sheet with PET fiber on the surface using an applicator to a target thickness of 250 μm, and then laminated together while pressing with a roller to prevent air bubbles from getting in. The laminate was heat-cured in an explosion-proof dryer at 90°C for one week, and then cut into 15 mm wide strips to prepare test specimens.

[0098] Subsequently, for each test piece, a tensile shear peel test was conducted in accordance with JIS K 6854-3 using a tensile testing machine (manufactured by A&D Company, Ltd., Tensilon TG-1210), and the shear peel strength was measured. The measurement was carried out under the conditions of a temperature of 23 to 25°C, a relative humidity of 50%, T-type peel, and a tensile speed of 50 mm / min. The number of tests was 5 times, and the average value excluding the maximum and minimum values was calculated and evaluated as the adhesive strength. The evaluation criteria are shown below. A: Shear peel strength of 5 MPa or more, and either cohesive failure of the adhesive layer or member failure after the peel test. B: Shear peel strength of 5 MPa or more, or either cohesive failure of the adhesive layer or member failure after the peel test. C: Shear peel strength less than 5 MPa.

[0099] <Adhesion evaluation by SAICAS method (interfacial adhesion with PVC substrate)> Using each of the above adhesives, they were applied to the surface of the PVC substrate using an applicator to a target thickness of 250 μm and heat-cured in an explosion-proof dryer at 90°C for 1 week to obtain test pieces.

[0100] For each test piece, a peel test was conducted using SAICAS (manufactured by Dypla Wintersteiger Co., Ltd., SAICAS EN-WA type), which is a peel strength evaluation device. The test was carried out under the conditions of a temperature of 23 to 25°C, a relative humidity of 50%, constant speed mode, diamond cutting blade, horizontal speed: 20 μm / s, vertical speed: 2 μm / s, cutting blade: diamond cutting blade (blade width 1.0 mm, rake angle 20°, relief angle 10°). After the test, the peeled surface was observed under a microscope and evaluated as the interfacial adhesion based on the degree of presence or absence of residues. Note that SAICAS is an abbreviation for Surface And Interfacial Cutting Analysis System. The evaluation criteria are shown below. Present: Residues were confirmed in an area of 30% or more of the peeled surface by microscopic observation. Absent: Residues were confirmed in an area of less than 30% of the peeled surface by microscopic observation.

[0101] Example 1 Test pieces were prepared for evaluating adhesion by the shear peel test and by the SAICAS method using the adhesive composition shown in Example 1 in Table 1. After the curing process, the test pieces prepared for evaluating adhesion by the SAICAS method were checked for stickiness by touching the surface of the cured adhesive with a finger, and it was found that there was absolutely no stickiness, confirming excellent curability.

[0102] Examples 2 to 14, Comparative Examples 1 to 2 As in Example 1, test specimens were prepared using each adhesive composition for evaluating adhesion using the shear peel test and the SAICAS method. The test specimens prepared for evaluating adhesion using the SAICAS method were checked for stickiness by touching the surface of the cured adhesive with a finger after the curing step. It was found that Examples 2 to 4, 7 to 11, and Comparative Example 1 were completely free of stickiness, confirming excellent curability. On the other hand, Examples 5, 6, 12, and 13 were almost free of stickiness, confirming good curability.

[0103] The results of Examples 1 to 14 and Comparative Examples 1 and 2 are shown in Table 1. In Examples 1 to 14, the results of the shear peel test were B or higher, and residue was observed on the substrate surface after the peel test of the cured film by the SAICAS method, confirming that the films have excellent adhesion to members containing vinyl chloride resin.

[0104] [Table 1] [Industrial Applicability]

[0105] The adhesive for vinyl chloride resin according to the present invention has excellent adhesion to components containing vinyl chloride resin, is not subject to limitations in the environment of use, and is highly versatile, making it suitable for use in a variety of applications where components containing vinyl chloride resin are used.

Claims

1. An adhesive for vinyl chloride resin for bonding members containing vinyl chloride resin, A composition comprising a halogen-containing polyether polyol (A), a halogen-free polyol (B), and a polyisocyanate (C), The halogen-containing polyether polyol (A) is a polyether polyol represented by the following formula (1) and having a number average molecular weight of 400 to 10,000: The adhesive for vinyl chloride resins, wherein the halogen-free polyol (B) is a polyol having a number average molecular weight of 400 or more and containing no halogen atoms. 【Chemical 1】 (In the above formula (1), Q represents a polymer component containing the following structural unit [I], m represents an integer of 2 to 3, R １ represents a residue of an active hydrogen-containing compound. 【Chemistry 2】 (In the structural unit [I], X represents a halogen atom.)

2. 2. The adhesive for vinyl chloride resins according to claim 1, comprising as the crosslinking agent (D) a compound having a number average molecular weight of less than 400 and having two or more hydroxyl groups in the molecule.

3. 3. The adhesive for vinyl chloride resins according to claim 1, wherein the halogen-containing polyether polyol (A) is contained in an amount of 3 to 40 mass% based on the total amount of the adhesive for vinyl chloride resins.

4. 3. The adhesive for vinyl chloride resins according to claim 1, wherein the halogen-free polyol (B) has a hydroxyl value of 10 to 500 mgKOH / g.

5. 3. The adhesive for vinyl chloride resins according to claim 1, wherein the halogen-free polyol (B) is contained in an amount of 3 to 40 mass% based on the total amount of the adhesive for vinyl chloride resins.

6. The adhesive for vinyl chloride resins according to claim 2, wherein the crosslinking agent (D) is contained in an amount of 1 to 10 mass% based on the total amount of the adhesive for vinyl chloride resins, and the crosslinking agent (D) includes a compound having two hydroxyl groups in the molecule and a compound having three hydroxyl groups in the molecule.

7. 3. The adhesive for vinyl chloride resin according to claim 1 or 2, wherein the polyisocyanate (C) is at least one of an aromatic polyisocyanate compound and a reaction product of an aromatic polyisocyanate compound with a polyol compound.

8. 3. An adhesive structure in which two or more members are bonded together via an adhesive layer, wherein at least one of the members comprises a vinyl chloride resin, and the adhesive layer is a cured product of the adhesive for vinyl chloride resin according to claim 1 or 2.

9. The bonded structure according to claim 8 , wherein the mating member to be bonded to the member containing vinyl chloride resin is a resin member having a fibrous surface.

Images