JP5499059B2 - Adhesive composition - Google Patents

Description

  The present invention relates to a moisture-curable polychloroprene solvent-based adhesive.

The polychloroprene solvent-based adhesive is an adhesive produced by dissolving polychloroprene in an organic solvent. An example of the use of this adhesive is bonding of interior parts such as an instrument panel, molded door, ceiling, and rear shelf of an automobile. High heat-resistant adhesive strength is required for adhesives for automotive interior parts. At present, moisture-curing adhesives utilizing the reaction between moisture in the air and silane compounds are widely used.
As a moisture curable adhesive, a polychloroprene solvent-based adhesive containing polychloroprene, metal oxide, oil-soluble phenol resin, organic solvent, and silane compound as components is known (for example, see Patent Document 1). This silane compound has at least one vinyl group, mercapto group, amino group or epoxy group in the molecule, and includes a substance generally called a silane coupling agent. The technique described in Patent Document 1 is intended to improve the phase separation of the phenol resin-containing adhesive and the heat-resistant adhesive force.
Further, a polychloroprene solvent-based adhesive (for example, see Patent Document 2) in which 0.1 to 10 parts by mass of a silane coupling agent is blended with 100 parts by mass of polychloroprene, polychloroprene modified with aminosilane, and adhesive. A polychloroprene solvent-based adhesive containing an imparting resin and an organic solvent as essential components (for example, see Patent Document 3) is known.
Furthermore, polychloroprene modified with epoxy silane, tackifying resin, metal oxide, polychloroprene solvent-based adhesive having an organic solvent as an essential component (see, for example, Patent Document 4), carboxyl group-containing polychloroprene Also known is a polychloroprene solvent-based adhesive (for example, see Patent Document 5) in which a silane compound having two or more alkoxysilyl bonds in the molecule is subjected to a condensation reaction, and a tackifier resin and an organic solvent are further blended. ing.
In addition, polychloroprene modified with an unsaturated silane compound having a specific structure, a tackifier resin, a polychloroprene solvent-based adhesive containing an organic solvent as an essential component (Patent Document 6), and modified with a silane compound having a specific structure Carboxyl group-containing polychloroprene, tackifying resin, polychloroprene solvent adhesive with organic solvent as essential components (Patent Document 7), polychloroprene grafted with a specific structure of mercaptosilane, tackifying resin, organic solvent are essential The polychloroprene solvent-based adhesive (Patent Document 8) and carboxyl group-containing polychloroprene 100 parts by mass are reacted with 2 to 20 parts by mass of an epoxy group-containing silane coupling agent, and further a reinforcing resin and tackifying. Polychloroprene solvent-based adhesives containing resin and inorganic filler (Patent Document 9), amino acid Emissions and two polychloroprene rubber silane compound grafted reaction of mercaptosilane, tackifying resins, polychloroprene solvent-based adhesives such as (Patent Document 10) are known in which an organic solvent as essential components.

JP-A 49-25032 JP 57-180672 A JP 62-290780 A JP-A-4-309586 JP 5-140522 JP-A-6-145620 JP-A-6-33026 JP-A-6-172730 JP-A-6-128541 JP-A-9-59579

  Each of these techniques utilizes the property that the silane compound reacts with moisture in the air. The alkoxysilyl group of the silane compound is hydrolyzed by moisture in the air to become a silanol group, and the silanol groups cause a dehydration condensation reaction between them. High adhesion can be demonstrated. However, the hydrolysis-condensation reaction of alkoxysilyl groups is a relatively slow reaction, and it has been necessary to cure for a long period of time in order to develop a sufficient adhesive force. Therefore, it has been a problem to increase the crosslinking reaction rate.

An object of the present invention is to provide a polychloroprene solvent-based adhesive which has a fast crosslinking reaction due to moisture and is excellent in adhesive strength and storage stability .

Polychloroprene solvent-based adhesion superior in adhesive strength and storage stability by containing a secondary amine compound not containing a silicon atom, a tackifier resin and an organic solvent in a polychloroprene polymer modified with an alkoxysilane compound The present inventors have found that an agent composition can be obtained, and solved the above problems. The alkoxysilane compound is preferably a vinyl group-containing compound.

According to the present invention, it is possible to obtain a polychloroprene solvent-based adhesive which has a fast crosslinking reaction due to moisture and is excellent in adhesive strength and storage stability .

  Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that the present invention is not limited to the embodiments described below.

  The polychloroprene polymer is a homopolymer of 2-chloro-1,3-butadiene (hereinafter referred to as chloroprene) or a copolymer of chloroprene and a monomer copolymerizable with chloroprene.

  Examples of monomers copolymerizable with chloroprene include 2,3-dichloro-1,3-butadiene, 1-chloro-1,3-butadiene, sulfur, methacrylic acid and esters thereof, and acrylic acid and esters thereof. Two or more types may be used as necessary. When a monomer other than chloroprene is used in combination, the charging amount is preferably 0.01 to 5 parts by mass in a total of 100 parts by mass of the monomers.

  The polychloroprene polymer is obtained by emulsion polymerization of the above monomer in water in the presence of an emulsifier and / or a dispersant. The emulsifier and / or dispersant used in the emulsion polymerization may be a general one such as an anionic compound, a nonionic compound, or a cationic compound used in the emulsion polymerization of chloroprene, and is not particularly limited. Specific examples of the anionic compound include a carboxylic acid type and a sulfate ester type. For example, an alkali metal salt of rosin acid, an alkyl sulfonate having 8 to 20 carbon atoms, an alkyl aryl sulfate, sodium naphthalene sulfonate and formaldehyde And the like. Specific examples of the nonionic compound include polyvinyl alcohol or a copolymer thereof (for example, a copolymer with acrylamide), polyvinyl ether or a copolymer thereof (for example, a copolymer with maleic acid), polyoxyethylene alkyl, and the like. Examples include ether, polyoxyethylene alkylphenol, sorbitan fatty acid ester, polyoxyethylene acyl ester and the like. Specific examples of the cationic compound include aliphatic amine salts, aliphatic quaternary ammonium salts, and the like, for example, octadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, dilauryldimethylammonium chloride and the like. Of these, it is most preferable to use an alkali metal salt of rosin acid.

  The amount of the emulsifier and / or dispersant used for emulsion polymerization, particularly the alkali metal salt of rosin acid, is preferably 0.5 to 20 parts by mass with respect to 100 parts by mass in total of the initial monomers charged. If it is less than 0.5 parts by mass, the emulsifying power is not sufficient, and if it exceeds 20 parts by mass, foaming during polymerization may become a problem, or the physical properties of the final adhesive composition may be adversely affected. .

  The conditions for emulsion polymerization are not particularly limited. By arbitrarily selecting the polymerization temperature, polymerization initiator, chain transfer agent, polymerization terminator, polymerization rate, etc., molecular weight, molecular weight distribution, molecular terminal structure, crystal It is possible to control the conversion rate.

  Although the polymerization temperature at the time of emulsion polymerization is not particularly limited, it is preferably 5 to 50 ° C. in order to carry out the polymerization reaction smoothly. The initiator is a persulfate such as potassium persulfate, an organic peroxide such as 3-butyl hydroperoxide, and the like, and is not particularly limited.

  The type of chain transfer agent is not particularly limited, and those usually used for emulsion polymerization of chloroprene can be used. For example, long chain alkyl mercaptans such as n-dodecyl mercaptan and tert-dodecyl mercaptan, diisopropyl xanthogen disulfide And dialkylxanthogen disulfides such as diethyl xanthogen disulfide, and known chain transfer agents such as iodoform can be used.

  The polymerization terminator (polymerization inhibitor) is not particularly limited, and for example, 2,6-tertiarybutyl-4-methylphenol, phenothiazine, hydroxyamine and the like can be used.

  Although the final polymerization rate is not particularly limited, it can be arbitrarily adjusted at 70 to 100%. Removal of the unreacted monomer (demonomer) is performed by a known method such as heating under reduced pressure.

  The polychloroprene polymer is prepared by dissolving the alkoxysilane compound in an organic solvent that does not react with the alkoxysilane compound, adding the polychloroprene polymer to the solution, and dissolving it, and reacting at a temperature between room temperature and the boiling point of the alkoxysilane compound. To obtain a polychloroprene polymer modified with an alkoxysilane compound.

  The alkoxysilane compound has 1 to 2 silicon atoms in the molecule, and an alkoxy group selected from a methoxy group, an ethoxy group, a propoxy group, or a 2-methoxyethoxy group is 1 to 3 in the silicon atom. It is a compound having a structure in which individual bonds are formed. In general, it is a compound called silane coupling agent. It is an amino group having an amino group, an epoxy group having an epoxy group, a vinyl group having a vinyl group, a mercapto group having a mercapto group, an isocyanate group having an isocyanate group, or a thioether. Either a sulfide system having a (sulfide) structure or a thiocyanate system having a thiocyanate group may be used.

  Specific examples of the amino-based alkoxysilane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, and 3- (2-aminoethyl) amino. Propylmethyldimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 1,2-etadiamine, hydrochloride of N- [3- (trimethoxysilyl) propyl]-, N-[(ethenylphenyl) methyl] derivatives, N -(Vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, N, N'-bis [3- (trimethoxysilyl) propyl] ethylenediamine, 3-ureidopropyltriethoxysilane, etc. It is done.

  Specific examples of the epoxy-based alkoxysilane compound include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropylmethyldiethoxy. Silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like.

  Specific examples of vinyl-based alkoxysilane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, vinylmethyldimethoxysilane, p-styryltrimethoxy. Silane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, etc. It is done.

  Specific examples of the mercapto-based alkoxysilane compound include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, and the like.

  Specific examples of the isocyanate-based alkoxysilane compound include 3-isocyanatepropyltrimethoxysilane and 3-isocyanatepropyltriethoxysilane.

  Specific examples of the sulfide-based alkoxysilane compound include 3-octanoylthio-1-propyltriethoxysilane, bis [3- (triethoxysilyl) propyl] disulfide, bis [3- (triethoxysilyl) propyl] tetrasulfide, and the like. Can be mentioned. Specific examples of the thiocyanate-based alkoxysilane compound include 3-thiocyanate propyltriethoxysilane.

  Of these, vinyl alkoxysilane compounds are most preferably used. When a polychloroprene polymer is modified with an alkoxysilane compound, an adhesive having good storage stability can be produced by using a vinyl-based alkoxysilane compound.

As for the preparation amount of an alkoxysilane compound, 0.1-10 mass parts is preferable with respect to 100 mass parts of polychloroprene polymers. When the amount of the alkoxysilane compound is less than 0.1 parts by mass, there are too few alkoxysilyl groups introduced into the polychloroprene polymer, and the crosslinking reactivity due to moisture becomes poor. On the other hand, when it is more than 10 parts by mass, the storage stability of the adhesive may be deteriorated.
The amount of alkoxysilyl group introduced into the polychloroprene polymer is preferably in the range of 0.1 to 6.5 mol%.

  When using a vinyl-based or mercapto-based alkoxysilane compound, the polychloroprene polymer and the alkoxysilane compound can be efficiently reacted by adding a radical initiator. The radical initiator in this case is not particularly limited, but azobisisobutyronitrile, azobis-2,4-dimethylpareronitrile, azobis (4-methoxy-2,4-dimethylpareronitrile), etc. Azo compounds, acetyl peroxide, benzoyl peroxide, lauroyl peroxide, acetylcyclohexylsulfonyl peroxide, peroxides such as 2,4,4-trimethylpentyl-2-peroxyphenoxyacetate, diisopropyl peroxydicarbonate , Percarbonate compounds such as di-2-ethylhexyl peroxydicarbonate, diethoxyethyl peroxydicarbonate, t-butylperoxyneodecanate, α-cumylperoxyneodecanate, t-butylperoxyneodecanate What perester compounds, azobisdimethylvaleronitrile, and the like can be used azo-bis-methoxy valeronitrile.

  The reaction temperature when the polychloroprene polymer is modified with an alkoxysilane compound is a temperature not higher than the boiling point of the alkoxysilane compound, and is determined in consideration of the decomposition temperature and half-life temperature of the radical initiator. The reaction terminator is not particularly limited, and for example, 2,6-tertiarybutyl-4-methylphenol, phenothiazine, hydroxyamine and the like can be used.

  The adhesive composition of the present invention essentially comprises an amine compound. The amine compound here is an amine compound that does not contain a silicon atom, and does not include amine-based alkoxysilanes.

  Specific examples of amine compounds include primary amine compounds such as acetamide (boiling point 222 ° C), aniline (boiling point 184.7 ° C), amylamine (boiling point 104.5 ° C), allylamine (boiling point 56 ° C), isobutylamine ( Boiling point 66 ° C), monoisopropanolamine (MIPA) (boiling point 159.2 ° C), isopropylamine (boiling point 32.4 ° C), 2-ethylhexylamine (boiling point 169 ° C), ethylenediamine (boiling point 117 ° C), cyclohexylamine (boiling point) 134.5 ° C), o-toluidine (boiling point 199.7 ° C), 2-butylamine (boiling point 63 ° C), t-butylamine (boiling point 44.5 ° C), propylenediamine (boiling point 121 ° C), heptylamine, monoethanol Amine (boiling point 171 ° C.), monoethylamine (boiling point 16.6 ° C.), mono-n- Ethylamine (boiling point 77.8 ° C.), monomethylamine (boiling point 93.5 ° C.), and the like.

  Specific examples of the secondary amine compound include diisopropanolamine (DIPA) (boiling point 248.7 ° C.), N-ethylethanolamine (boiling point 169 ° C.), caprolactam (solid at room temperature), o-chloroaniline (boiling point 208. 8 ° C), diamylamine (boiling point 202 ° C), diisobutylamine (boiling point 138 ° C), diisopropylamine (boiling point 83.9 ° C), diethanolamine (boiling point 269.1 ° C), diethylamine (boiling point 55.5 ° C), diethylenetriamine (boiling point) 207 ° C), dioctylamine (boiling point 297 ° C), dicyclohexylamine (boiling point 255.8 ° C), diphenylamine (boiling point 302 ° C), di-n-butylamine (boiling point 159.6 ° C), dimethylamine (boiling point 6.9 ° C) ), Piperidine (boiling point 105.6 ° C.), 4-pipecoline (boiling point 1) 4 ° C), piperazine (boiling point 145 ° C), pyrrolidine (boiling point 88 ° C), 2-pyrrolidone (boiling point 245 ° C), N-butylethanolamine (boiling point 199 ° C), N-methylformamide (boiling point 197 ° C), morpholine ( Boiling point 128 ° C.).

  Specific examples of the tertiary amine compound include triisopropanolamine (TIPA) (boiling point 305 ° C.), N-ethylmorpholine (boiling point 138 ° C.), diisopropylethylamine (boiling point 127 ° C.), N, N-diethylaniline (boiling point 217). 0.1 ° C), diethylbenzylamine (boiling point 212 ° C), N, N-dibutylaniline (boiling point 266 ° C), N, N-dibutylethanolamine (boiling point 299 ° C), N, N-dimethylaniline (boiling point 194 ° C) N, N-dimethylformamide (boiling point 153 ° C.), triallylamine (boiling point 233.9 ° C.), triethanolamine (boiling point 360 ° C.), triethylamine (boiling point 89.4 ° C.), trioctylamine (boiling point 365 ° C.), Tri-n-butylamine (boiling point 214 ° C.), tripropylamine (boiling point 151 ° C.), etc. It is below.

Among the amine compounds, secondary amine compounds are used. As for content of an amine compound, 0.5-2.5 mol is preferable with respect to 1 mol of silicon atoms in an adhesive composition.

The organic solvent used in the present invention is not particularly limited and may be selected in consideration of the solubility of the chloroprene polymer.
Specific examples of the organic solvent include toluene, xylene, acetone, methyl ethyl ketone (MEK), ethyl acetate, butyl acetate, cyclohexane, dichloromethane, tetrahydrofuran (THF), N-methyl-2-pyrrolidone (NMP), and the like. You may mix the above organic solvent. The addition amount of the organic solvent is preferably 150 to 1900 parts by mass with respect to 100 parts by mass of the polychloroprene polymer. More preferably, it is 200-1000 mass parts or less. When the amount is less than 150 parts by mass, the solid content concentration and the viscosity are too high, which may cause a problem in coating properties. Moreover, when it exceeds 1900 mass parts, there exists a possibility that the solid content density | concentration of an adhesive composition may become low too much and adhesive performance may fall.

  The adhesive composition of the present invention preferably contains zinc oxide. The chloroprene polymer has a property of causing a dehydrochlorination reaction over time when exposed to sunlight or stored for a long time at a high temperature. Since zinc oxide plays a role as an acid acceptor for hydrochloric acid, if it is blended, the storage stability of the adhesive can be improved, or discoloration can be suppressed. The content of zinc oxide is preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the polychloroprene polymer. If it is less than 0.05 part by mass, the effect of improving the adhesive strength cannot be obtained, and if it exceeds 10 parts by mass, the adhesion between the polymers may be hindered and adhesion failure may occur.

  The kind of zinc oxide is not particularly limited. The zinc oxide production method includes the indirect method of vaporizing metallic zinc and oxidizing zinc vapor to produce zinc oxide, or vaporizing zinc zinc from ore while reducing zinc to oxidize zinc vapor to produce zinc oxide. There are direct methods to produce, wet methods to produce zinc carbonate in the aqueous phase and calcining it, etc., depending on the production method, powder characteristics such as particle diameter, surface area, particle shape, etc. Any zinc oxide may be used. The particle shape may be any of an indeterminate shape, porosity, fine particles, spherical shape, flake shape, needle shape, and tetrapot shape. In addition, zinc oxide can be surface-treated with a silane coupling agent, a titanate coupling agent, or an aluminum coupling agent before blending into the adhesive to improve the adhesive strength.

The adhesive composition of the present invention is blended with a tackifying resin in order to improve the adhesiveness (tack) immediately after coating and to improve the adhesive force. The tackifying resin is one generally used in the field of solvent-based adhesives, and the type thereof is not limited. Examples of tackifying resins, rosin resins, rosin ester resins, hydrogenated rosin resins, polymerized rosin resins, alpha-pinene resins, beta-pinene resins, terpene phenol resins, C ₅ fraction petroleum resin, C ₉ fraction Examples thereof include branched petroleum resins, C ₅ / C ₉ fraction petroleum resins, DCPD petroleum resins, alkylphenol resins, xylene resins, coumarone resins, coumarone indene resins, and the like. For example, when using for the adhesion | attachment of the shoe sole of shoes or components, a thing with a softening point of 80-150 degreeC is considered in consideration of heat resistant adhesive force.

  The addition amount of the tackifier resin is 5 to 100 parts by mass, preferably 20 to 80 parts by mass with respect to 100 parts by mass of the chloroprene polymer. When 5 parts by mass or more of the tackifier resin is used, the initial adhesive force and the normal adhesive force are improved, but when it exceeds 100 parts by mass, the flexibility of the adhesive film may be impaired.

  The adhesive composition of the present invention includes a thickener, a vulcanization accelerator, a filler (reinforcing agent), a pigment, a colorant, an antioxidant, an ultraviolet absorber, and an antifungal agent, depending on the application and required performance. , Preservatives, antibacterial agents, plasticizers, rust inhibitors, polymers other than polychloroprene, and the like can be optionally blended.

The conditions for using the adhesive composition of the present invention are not particularly limited.
Examples of adherends include metal, wood, concrete, rubber, fiber cloth, and ceramics. For footwear, for example, fabrics (knitted fabrics such as nylon, polyester, and cotton, woven fabrics, non-woven fabrics), natural leather (cowhide) , Kangaroo leather, etc.), artificial leather (polyurethane, polyvinyl chloride resin, etc.), vulcanized rubber (SBR, CR, IR, IIR, NBR, BR), resin (foamed or non-foamed material such as polyurethane, EVA), etc. Can be used for bonding. However, in order to advance the crosslinking reaction of the adhesive by moisture, it is preferable that at least one adherend is a material that allows moisture to pass through, such as wood, fiber cloth, and open cell foam.

  There are no particular restrictions on the application method and apparatus specifications. Specifically, a curtain flow coater method, a bar coater method, a roll coater method, a spray method and the like can be mentioned. Further, examples of the roll coater method include a gravure roll coater method and a reverse gravure coater method. An application method suitable for the application may be selected. For example, the spray method is preferable for applications where application is uniform, and manual operation with a brush is preferable for bonding parts having a small application area such as small parts.

  The pressure bonding apparatus, pressure bonding conditions, and press pressure are not particularly limited, and the pressure bonding operation after stacking two adherends may be either a hot press or a room temperature press. Moreover, integral molding adhesion may be sufficient.

  Hereinafter, the effects of the present invention will be specifically described with reference to Examples and Comparative Examples of the present invention.

[Example 1]
<Preparation of polychloroprene polymer>
To a reactor having an internal volume of 10 liters, in a nitrogen atmosphere, 100 parts by mass of water, 5 parts by mass of sodium salt of rosin acid, 0.3 part by mass of sodium hydroxide, sodium salt of formaldehyde naphthalenesulfonic acid condensate 0.6 First, 100 parts by mass of chloroprene monomer and 0.25 parts by mass of n-dodecyl mercaptan were added while stirring, after charging parts by mass and 0.5 parts by mass of sodium sulfite. Using 0.1 parts by mass of potassium persulfate as a polymerization initiator, polymerization was performed at 10 ° C. in a nitrogen atmosphere, and when the final polymerization rate reached 70%, an emulsion of phenothiazine was added to terminate the polymerization. Unreacted monomers were removed under reduced pressure to obtain polychloroprene latex. This latex was freeze-dried to produce a polychloroprene polymer.

<Preparation of alkoxysilyl-modified polychloroprene polymer solution>
100 parts by mass of polychloroprene polymer is dissolved in a mixed solution of 250 parts by mass of cyclohexane and 250 parts by mass of ethyl acetate, and vinyltriethoxysilane (A-151 (made by Momentive Performance Materials Japan LLC)) 4 0.8 parts by mass, 0.67 parts by mass of benzoyl peroxide (purity 75%) and 0.5 parts by mass of azobisisobutyronitrile (AIBN) were added and reacted at 70 ° C. for 5 hours. -Di-t-butyl-4-methylphenol (BHT) (Nocrac200 (made by Ouchi Shinsei Chemical Co., Ltd.)) 2.0 mass parts was added, and it cooled to 25 degreeC. Thereby, 607.97 parts by mass of a cyclohexane / ethyl acetate solution of an alkoxysilyl-modified polychloroprene polymer was obtained.
<Preparation of adhesive>
Magnesium oxide (MgO) is Kyowamag 150 (manufactured by Kyowa Chemical Industry Co., Ltd.), zinc oxide is zinc oxide (manufactured by Hakusui Tech Co., Ltd.), and the antioxidant 2,6-di-t-butyl-4- As the methylphenol (BHT), Nocrac 200 (manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.) was used, and as the tackifier resin, Tamanol 526 (manufactured by Arakawa Chemical Industry Co., Ltd.), an alkylphenol resin having a softening point of 115 to 130 ° C., was used.
First, 140 parts by mass of cyclohexane, tamanol 526 = 60 parts by mass, and 3.0 parts by mass of magnesium oxide (MgO) were stirred with a ball mill for 2 days to prepare a cyclohexane solution of a tackifying resin. Next, to the cyclohexane solution of this tackifier resin, 3.0 parts by mass of magnesium oxide (MgO), 3.0 parts by mass of zinc oxide, 607.97 parts by mass of a cyclohexane / ethyl acetate solution of an alkoxysilyl-modified polychloroprene polymer, Diethanolamine (secondary amine) 5.3 parts by mass was added and stirred with a ball mill for 2 days to prepare an adhesive.
<Evaluation test of adhesive strength>
First, two cotton canvases were prepared. The size of the adhesive margin is 25 mm wide × 50 mm long. An adhesive was applied to both of the two adherends so that the amount applied was 2400 wet-g / m ² . After an open time of 30 minutes at 25 ° C., they were bonded together and bonded by reciprocating 10 pound rolls 5 times.
The normal adhesive strength is the T-type peel strength after curing for 15 days in a room at 23 ° C. and a humidity of 30% RH. The humidified normal adhesive strength is a T-type peel strength after pasting and curing for 8 days in a room at 23 ° C. and 30% RH, and further for 7 days in a room at 35 ° C. and 90% RH. The heat-resistant adhesive strength is a T-type peel strength when peeled in an 80 ° C. atmosphere after 15 days of curing in a room at 3 ° C. and a humidity of 30% RH after bonding. Humidity and heat-resistant adhesive strength is T-type when it is peeled in an 80 ° C atmosphere after being cured for 8 days in a 23 ° C, 30% RH room, and further in a 35 ° C, 90% RH room for 7 days. Peel strength. In either case, the tensile speed of the peel test is 50 mm / min.
<Evaluation test of heat-resistant creep characteristics>
After crimping, test specimens cured for 15 days in a room at 23 ° C. and humidity 30% RH, and after curing for 8 days in a room at 23 ° C. and humidity 30% RH, further 35 ° C. and 90% RH A test piece cured for 7 days was prepared. The holding margin of one of the test pieces (the size of the adhesive margin is 25 mm wide × 25 mm long) was fixed to the ceiling of the oven, and the inside of the oven was maintained at 80 ° C. In the manner of the 180 ° peel test, a weight of 500 g was attached to the other grip, and the time from when the weight was attached to when the weight dropped was measured. It means that heat resistance adhesive force is so high that this time is long.
<Storage stability of adhesive>
The viscosity at 25 ° C. immediately after preparation of the adhesive and the viscosity at 25 ° C. after placing the adhesive in a sealed container and allowing to stand at 23 ° C. for 1 month were measured using a B-type viscometer.

[ Reference Example 1 ]
The diethanolamine of the amine compound of Example 1 was changed to 3.1 parts by mass of monoethanolamine (primary amine). In the same manner as in Example 1, adhesive strength and heat-resistant creep characteristics were evaluated.

[ Reference Example 2 ]
The diethanolamine of the amine compound of Example 1 was changed to 7.5 parts by mass of triethanolamine (tertiary amine). In the same manner as in Example 1, adhesive strength, heat-resistant creep characteristics, and storage stability were evaluated.

[ Example 2 ]
A-151 of the alkoxysilane compound of Example 1 was changed to 3.3 parts by mass of vinylmethyldimethoxysilane (A-2171 (manufactured by Momentive Performance Materials Japan GK)). In the same manner as in Example 1, adhesive strength, heat-resistant creep characteristics, and storage stability were evaluated.

[ Example 3 ]
A-151 of the alkoxysilane compound of Example 1 was changed to 7.0 parts by mass of 3-glycidoxypropyltriethoxysilane (A-1871 (manufactured by Momentive Performance Materials Japan LLC)). In the same manner as in Example 1, adhesive strength, heat-resistant creep characteristics, and storage stability were evaluated.

[ Example 4 ]
A-151 of the alkoxysilane compound of Example 1 was changed to 4.9 parts by mass of 3-mercaptopropyltrimethoxysilane (A-189 (made by Momentive Performance Materials Japan GK)). In the same manner as in Example 1, adhesive strength, heat-resistant creep characteristics, and storage stability were evaluated.

[ Example 5 ]
A-151 of the alkoxysilane compound of Example 1 was changed to 4.5 parts by mass of 3-aminopropyltrimethoxysilane (A-1110 (manufactured by Momentive Performance Materials Japan LLC)). In the same manner as in Example 1, adhesive strength, heat-resistant creep characteristics, and storage stability were evaluated.

[Comparative Example 1]
An adhesive was prepared under the same conditions as in Example 1 except that the amine compound diethanolamine was not added, and adhesive strength, heat-resistant creep properties, and storage stability were evaluated in the same manner as in Example 1.

[Comparative Example 2]
Adhesives were prepared under the same conditions as in Example 4 except that the amine compound diethanolamine was not added, and adhesive strength, heat-resistant creep properties, and storage stability were evaluated in the same manner as in Example 4.

[Comparative Example 3]
An adhesive was prepared under the same conditions as in Example 5 except that the amine compound diethanolamine was not added, and adhesive strength, heat-resistant creep properties, and storage stability were evaluated in the same manner as in Example 5.

[Comparative Example 4]
An adhesive was prepared under the same conditions as in Example 6 except that the amine compound diethanolamine was not added, and adhesive strength, heat-resistant creep properties, and storage stability were evaluated in the same manner as in Example 6.

[Comparative Example 5]
An adhesive was prepared under the same conditions as in Example 7 except that the amine compound diethanolamine was not added, and adhesive strength, heat-resistant creep properties, and storage stability were evaluated in the same manner as in Example 7.

[Comparative Example 6]
Except for using polychloroprene that has not been modified with an alkoxysilane compound, the adhesive was adjusted under the same conditions as in Example 1 and the same method as in Example 1 was followed. Adhesive strength, heat-resistant creep properties, storage stability Sex was evaluated.

The evaluation results are summarized in Tables 1 and 2.

As can be seen from Tables 1 and 2, the adhesives used in combination of the polychloroprene polymers modified with the alkoxysilane compounds of Examples 1 to 5 and the amine compounds not containing silicon atoms are those of Comparative Examples 1 to 5. Compared to an adhesive that does not use an amine compound that does not contain a silicon atom, it exhibits superior adhesive strength and heat-resistant creep characteristics. The amine compound is superior in heat-resistant creep characteristics and storage stability when a secondary amine (Example 1) is used rather than a primary amine ( Reference Example 1 ) and a tertiary amine ( Reference Example 2 ). Moreover, the adhesives (Examples 1 to 3) using vinyl group-containing alkoxysilane compounds are superior in adhesive strength and heat-resistant creep characteristics to the adhesives (Examples 4 to 7) using other alkoxysilane compounds. Shows storage stability.

Claims (3)

A polychloroprene solvent-based adhesive composition comprising a polychloroprene polymer modified with an alkoxysilane compound, a secondary amine compound not containing a silicon atom, a tackifier resin, and an organic solvent. The polychloroprene solvent-based adhesive composition according to claim 1, wherein the secondary amine compound containing no silicon atom is diethanolamine . The polychloroprene solvent-based adhesive composition according to claim 1 or 2, wherein the alkoxysilane compound is a vinyl group-containing compound.