JP6897348B2 - Adhesive-imparting resin, adhesive-imparting resin emulsion, water-based adhesive composition, polychloroprene latex-based adhesive composition - Google Patents

Description

The present invention relates to a tackifier resin, a tackifier resin emulsion, a water-based adhesive composition and a polychloroprene latex-based adhesive composition.

Adhesives are used in a wide range of fields such as packaging, construction, and building materials. Generally, polychloroprene, styrene-butadiene copolymers, acrylic polymers, natural rubber, vinyl acetate, and ethylene-vinyl acetate are used together. A tack-imparting resin is added to the polymer or polyurethane base polymer in order to impart tacky properties such as tack.

Conventionally, the solvent type adhesive has been widely used, but the solvent type adhesive contains an organic solvent such as toluene, ethyl acetate, and normal hexane. Therefore, water-based adhesives are being actively studied as those that have less environmental load such as air pollution, are excellent in safety and health, and are suitable for resource saving.

Conventionally, water-based adhesives include polychloroprene latex, styrene-butadiene copolymer latex, acrylic polymer emulsion, natural rubber latex, vinyl acetate emulsion, ethylene-vinyl acetate copolymer emulsion, urethane emulsion and the like. It is known that a base polymer is blended with a tackifying resin emulsion such as rosins, rosin derivatives, petroleum-based resins, terpene-based resins, phenol resins, and ketone resins.

Among the water-based adhesives, the water-based adhesive using polychloroprene latex as the base polymer has high initial adhesive strength, and when this is applied to both of the adherends to be bonded and the adhesive layers are bonded to each other after drying. , High adhesive strength develops immediately after. Due to these characteristics, polychloroprene latex-based water-based adhesives are expected to be used as water-based contact-type adhesives. On the other hand, the initial adhesive strength is inferior to that of the solvent-based adhesive described above, and improvement thereof has been an issue.

As a means for improving the initial adhesive strength, a method of adding a tackifier obtained by emulsifying a rosin-modified phenol resin to a polychloroprene latex adhesive is known. (Patent Document 1). However, there is a problem that phenol is liberated during the use of the obtained adhesive and the working environment is deteriorated. Further, as a tackifier with less liberation of phenol, there is an emulsion of terpenephenol resin, but the polychloroprene latex adhesive to which the tackifier is added has a problem that the heat-resistant adhesive strength is inferior.

As a phenol-free tackifier, an emulsion of rosin ester is also known (Patent Document 2), but the polychloroprene latex adhesive to which this is added has insufficient initial adhesive strength.

Japanese Unexamined Patent Publication No. 2010-1458 Japanese Patent No. 3415659

The present invention is a phenol-free tackifier resin that improves the initial adhesive strength of various water-based adhesives, especially polychloroprene latex-based adhesive compositions, while maintaining the normal adhesive strength and heat-resistant adhesive strength. , A new object is to provide a rosin ester-based tackifier resin.

As a result of diligent studies, the present inventor has found that a specific tackifier resin can solve the above problems. That is, the present invention relates to the following tackifier resin, tackifier resin emulsion, water-based adhesive composition, and polychloroprene latex-based adhesive composition.

1. 1. A tackifier resin comprising a rosin ester which is a reaction product of (A) rosin, (B) α, β unsaturated carboxylic acid-modified rosin, and (C) alcohol and satisfies the following requirements 1 and 2.
Requirement 1: The content of the skeleton derived from dehydroabietic acid is 20% by mass or more Requirement 2: The peak area (S2) of the component having a weight average molecular weight of 1,200 or more with respect to the total peak area (S1) measured by gel permeation chromatography. ) Is 20-50%

2. Item (A) The tackifier resin according to Item 1, wherein the component is natural rosin and / or disproportionated rosin.

3. 3. Item (B) The tackifier resin according to Item 1 or 2, wherein the α, β unsaturated carboxylic acid constituting the component is fumaric acid and / or maleic acid.

4. The tackifier resin according to any one of Items 1 to 3 above, wherein the component (C) is at least one selected from the group consisting of dihydric alcohols, trihydric alcohols and tetrahydric alcohols.

5. A tackifier resin emulsion which is an emulsion of the tackifier resin according to any one of Items 1 to 4.

6. The water-based adhesive composition containing the tackifier resin emulsion and the base resin according to Item 5.

7. A polychloroprene latex-based adhesive composition containing the tackifier resin emulsion and polychloroprene latex according to Item 5.

The tackifier resin of the present invention can be used as an additive for various water-based adhesives, particularly polychloroprene latex-based adhesive compositions, and can increase the initial adhesive strength without lowering their normal adhesive strength and heat-resistant adhesive strength. .. In addition, since phenol is not desorbed, it contributes to the improvement of the working environment.

The tackifier resin of the present invention can be combined with an aqueous base polymer other than polychloroprene latex or a non-aqueous base polymer.

The polychloroprene latex-based adhesive composition of the present invention is useful not only for shoe adhesives that require initial adhesive strength, normal adhesive strength, and heat-resistant adhesive strength, but also for various adhesive products such as adhesives for furniture and building materials. ..

The tackifier resin of the present invention includes (A) rosin (hereinafter, component (A)), (B) α, β-unsaturated carboxylic acid-modified rosin (hereinafter, component (B)), and (C) alcohol (hereinafter, component). It is a reaction product of (component (C)).

As the component (A), various rosins can be used without particular limitation. Specifically, for example, gum rosin, tall oil rosin, and wood rosin containing resin acids such as avietic acid, palastolic acid, neo-avietic acid, levopimalic acid, pimalic acid, isopimalic acid, sandalacopimalic acid, and dehydroavietic acid as main components Natural rosin such as; Purified rosin obtained by purifying natural rosin; Hydrogenated rosin obtained by hydrogenating natural rosin; Disproportionated rosin obtained by disproportionating natural rosin; Polymerizing natural rosin Examples thereof include polymerized rosins obtained by allowing them to be allowed to grow, and these can be used alone or in combination of two or more.

The purified rosin can be obtained by using various known means such as a distillation method, an extraction method and a recrystallization method. In the distillation method, for example, the natural rosin may be distilled at a temperature of about 200 to 300 ° C. and a reduced pressure of about 0.01 to 3 kPa. Further, in the extraction method, for example, the natural rosin may be used as an alkaline aqueous solution, an insoluble unkenzine may be extracted with various organic solvents, and then the aqueous layer may be neutralized. Further, in the recrystallization method, for example, the natural rosin may be dissolved in an organic solvent as a good solvent, then the solvent may be distilled off to form a concentrated solution, and an organic solvent as a poor solvent may be added.

The hydrogenated rosin can be obtained by using various known means. Specifically, for example, the natural rosin may be heated at about 100 to 300 ° C. in the presence of a hydrogenation catalyst and in a hydrogen atmosphere at about 2 to 20 MPa. The reaction pressure is preferably about 5 to 20 MPa, and the reaction temperature is preferably about 150 to 300 ° C. As the hydrogenation catalyst, various known catalysts such as a supported catalyst and a metal powder can be used. Examples of the supported catalyst include palladium carbon, rhodium carbon, ruthenium carbon, platinum carbon and the like. Examples of the metal powder include nickel and platinum. Among these, palladium, rhodium, ruthenium, and platinum-based catalysts are preferable because they have a high hydrogenation rate of rosins and a short hydrogenation time. The amount of the hydrogenation catalyst used is usually about 0.01 to 5 parts by mass, preferably about 0.01 to 2 parts by mass with respect to 100 parts by mass of natural rosin.

The disproportionated rosin can be obtained by using various known means. For example, the natural rosin and / or purified rosin may be heated and reacted in the presence of a disproportionation catalyst. Examples of the disproportioning catalyst include various known catalysts such as supported catalysts such as palladium-carbon, rhodium-carbon and platinum-carbon, metal powders such as nickel and platinum, and iodides such as iodine and iron iodide. .. The amount of the catalyst used is usually about 0.01 to 5 parts by mass, preferably about 0.01 to 1 part by mass, and the reaction temperature is about 100 to 300 ° C., preferably about 100 parts by mass with respect to 100 parts by mass of rosin as a raw material. It is about 150 ° C. to 290 ° C.

The polymerized rosin can be obtained by using various known means. Specifically, for example, a method of heating rosin as a raw material at about 40 to 160 ° C. for about 1 to 5 hours in an organic solvent containing a catalyst such as sulfuric acid, hydrogen fluoride, aluminum chloride, and titanium tetrachloride is used. Can be mentioned. Examples of the organic solvent include toluene and xylene.

As the component (A), natural rosin and / or disproportionated rosin are particularly preferable from the viewpoint of initial adhesive strength, and disproportionated rosin is particularly preferable in consideration of facilitating achievement of Requirement 1. The resin acid composition of the disproportionated rosin is not particularly limited, but usually, dehydroabietic acid is about 30 to 100% by mass.

The component (B) is an addition reaction product of various rosins and α, β unsaturated carboxylic acids. As the rosin, the above-mentioned component (A) can be used, and a rosin containing about 20 to 50% by mass of abietic acid is particularly preferable from the viewpoint of addition reaction with α, β unsaturated carboxylic acid. Examples of the α and β unsaturated carboxylic acids include (maleic anhydride), fumaric acid, itaconic acid, (anhydrous) citraconic acid, and (meth) acrylic acid. Among these, it is particularly preferable to use fumaric acid and / or maleic acid because the heat-resistant adhesive strength of the water-based adhesive using the tackifier resin according to the present invention is particularly good.

The method for producing the component (B) is not particularly limited, and various known methods can be adopted. Specifically, for example, the component (A) and α, β unsaturated carboxylic acid may be reacted at about 150 to 300 ° C. for about 1 to 24 hours. The amount of the α, β unsaturated carboxylic acid used is not particularly limited, but is usually about 0.1 to 20 parts by mass with respect to 100 parts by mass of the component (A).

As the component (C), various known components can be used without particular limitation. Specific examples thereof include monohydric to octavalent alcohols. Examples of the monohydric alcohol include known ones such as stearyl alcohol and isostearyl alcohol. Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylene glycol, tetramethylene glycol, 1,3-butanediol, 1,6-hexanediol, and dimerdiol. Can be mentioned. Examples of the trihydric alcohol include glycerin, trimethylolpropane, trimethylolethane, trimethylolethane and the like. Examples of the tetrahydric alcohol include pentaerythritol and diglycerin. Examples of the pentahydric alcohol include xylitol and the like. Examples of the hexahydric alcohol include dipentaerythritol and the like. Examples of the octahydric alcohol include tripentaerythritol and the like. These may be used alone or in admixture of two or more. The alcohols may be an amino alcohol having an amino group in the molecule, a glycidyl alcohol having a glycidyl group in the molecule, or a silyl alcohol containing a silyl group. The component (C) is more than the group consisting of dihydric alcohols, trihydric alcohols and tetrahydric alcohols in that it makes it easier to achieve Requirement 2 and balances initial adhesive strength, normal adhesive strength, and heat-resistant adhesive strength. At least one selected is preferred.

The tackifier resin of the present invention is a reaction product of the component (A), the component (B) and the component (C). The mode for producing the reaction product is not particularly limited, and examples thereof include the following methods.
(A): Method of esterifying component (A), component (B) and component (C) in one pot (B): Esterized product of component (A) and component (C), component (B) and (C) ) Method of mixing the esterified product of the component (c): Method of reacting the component (B) with the residual hydroxyl group of the esterified product of the component (A) and the component (C) (d): component (B) and (C) Method of reacting component (A) with the residual hydroxyl group of the esterified product of the component (e): Method of adding α, β unsaturated carboxylic acid to the esterified product of the component (A) and the component (C).

The conditions of the esterification reaction are not particularly limited, but usually, the above-mentioned raw materials may be subjected to a heat dehydration reaction at about 250 to 280 ° C. for about 1 to 8 hours. In addition, various known esterification catalysts and organic solvents can be used during the reaction. Examples of the esterification catalyst include acid catalysts such as acetic acid and p-toluenesulfonic acid; hydroxides of alkaline earth metals such as calcium hydroxide; and metal oxides such as calcium oxide and magnesium oxide. Examples of the organic solvent include ketones such as benzene, toluene, xylene, chloroform, lower alcohol and acetone, and lower alkyl acetate such as ethyl acetate. Further, the esterification reaction can be carried out under any pressure condition of normal pressure, pressure and reduced pressure.

The ratio of the components (A), (B) and (C) to be used is not particularly limited, but considering the balance between the initial adhesive strength, the normal adhesive strength and the heat-resistant adhesive strength, the hydroxyl groups contained in the component (C) (Mole) / (Mole of carboxyl group contained in component (A) and component (B)) = about 1 to 1.5. Further, the usage ratio of the component (A) and the component (B) is not particularly limited, but from the same viewpoint, the mass ratio of the former / the latter is usually preferably in the range of about 4 to 8.

The rosin ester, which is a tackifier resin of the present invention, is characterized in that the content of the skeleton derived from Requirement 1: dehydroabietic acid is 20% by mass or more. If this is less than 20% by mass, the compatibility between the reactant and the base resin (particularly polychloroprene latex) of the adhesive is deteriorated, and the initial adhesive strength tends not to be exhibited. From this point of view, the content is preferably about 25 to 45% by mass.

The method for adjusting the content of the dehydroabietic acid-derived skeleton is not particularly limited, and a known method may be adopted. Specifically, at any stage of the manufacturing process, heat treatment is performed at 250 to 300 ° C. for 1 to 5 hours without a catalyst, or a heating reaction is carried out in the presence of a disproportionation catalyst. The resin acid in the component (A) and the component (B) can be disproportionated. Examples of the disproportionation catalyst include various known catalysts such as metal powders such as nickel and platinum, iodides such as iodine and iron iodide, and palladium carbon. The amount of the catalyst used is 0.01 to 3% by mass, preferably 0.05 to 1% by mass, based on rosin. The reaction temperature is preferably 100 to 300 ° C., preferably 150 to 290 ° C., and the heating time is preferably 1 to 8 hours, preferably 2 to 5 hours.

Dehydroabietic acid is a resin acid having an aromatic ring in its molecular skeleton, as shown below.

The "skeleton derived from dehydroabietic acid" refers to the remaining structure obtained by removing the tertiary carboxyl group from dehydroabietic acid.

The content of the dehydroabietic acid-derived skeleton in the reaction product can be determined by various known methods. Specifically, for example, the hydrolyzate of the reaction product is subjected to a gas chromatograph mass spectrometer, and the peak observed near the retention time of 45 minutes is defined as peak 1 belonging to the structure of Chemical formula 2, and the retention time is 15 minutes or later. It can be determined from the area ratio of peak 1 among the total peak areas observed in.

The rosin ester, which is a tackifier resin of the present invention, has a total peak area (S2) of a high molecular weight component having a weight average molecular weight of 1,200 or more with respect to the total peak area (S1) measured by Requirement 2: gel permeation chromatography. It is also characterized in that the ratio is 20 to 50%. If this exceeds 50%, the adhesive layer of the water-based adhesive composition containing the tackifier resin of the present invention becomes hard, and the initial adhesive strength tends to be difficult to develop. Further, when this is less than 20%, the heat-resistant adhesive strength tends to decrease. From this point of view, the ratio of S2 to S1 is preferably about 30 to 40%.

The rosin ester, which is a tackifier resin of the present invention, further comprises the total peak area (S2) of low molecular weight components having a weight average molecular weight of less than 1,200 with respect to the total peak area (S1) measured by Requirement 3: gel permeation chromatography. ) Is preferably 50 to 80%. Examples of the low molecular weight component include rosin, an ester of rosin, a part of an ester of an acid-modified rosin, and a low boiling component contained in rosin. When S2 is in such a range, the adhesive layer becomes flexible and the initial adhesive strength tends to be easily developed. From this point of view, the ratio of S2 is preferably about 70 to 60%.

Other physical properties of the tackifier resin of the present invention include, for example, a softening point of about 75 to 150 ° C. and an acid value of about 0.5 to 30 mgKOH / g.

The tackifier resin of the present invention can be used as it is as an additive for a solvent-based adhesive. It can also be used as an additive for water-based adhesives as it is or in the form of an emulsion.

The tackifier resin emulsion of the present invention is an emulsion of the tackifier resin of the present invention. Examples of the emulsifier to be used include a high molecular weight emulsifier obtained by polymerizing a monomer, a low molecular weight anionic emulsifier, a low molecular weight nonionic emulsifier, and the like, and two or more kinds can be used in combination.

Examples of the monomer used for producing the high molecular weight emulsifier include (meth) acrylic acid ester-based monomers such as methyl (meth) acrylate and ethyl (meth) acrylate; (meth) acrylate, crotonic acid and the like. Monocarboxylic acid-based vinyl monomers; Dicarboxylic acid-based vinyl monomers such as maleic acid and maleic anhydride; and sulfonic acid-based vinyl monomers such as vinyl sulfonic acid and styrene sulfonic acid; and alkalis of these various organic acids. Metal salts, alkaline earth metal salts, ammonium salts, organic base salts; (meth) acrylamide-based monomers such as (meth) acrylamide and N-methylol (meth) acrylamide; nitrile-based monomers such as (meth) acrylonitrile Classes; Vinyl ester-based monomers such as vinyl acetate; Hydroxy group-containing (meth) acrylic acid ester-based monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; Methylvinyl ether, glycidyl Examples thereof include (meth) acrylate, urethane acrylate, α-olefin having 6 to 22 carbon atoms, other monomers such as vinylpyrrolidone, and two or more thereof can be used in combination.

Examples of the method for polymerizing the monomer include solution polymerization, suspension polymerization, and emulsion polymerization. Various known reactive emulsifiers and / or non-reactive emulsifiers can be used for emulsion polymerization. The reactive emulsifier is, for example, a surfactant having a hydrophilic group such as a sulfonic acid group or a carboxyl group and a hydrophobic group such as an alkyl group or a phenyl group, and has a carbon-carbon double bond in the molecule. Things can be mentioned. Examples of the carbon-carbon double bond include functional groups such as a (meth) allyl group, a 1-propenyl group, a 2-methyl-1-propenyl group, a vinyl group, an isopropenyl group, and a (meth) acryloyl group. .. Specific examples of the reactive emulsifier include polyoxyethylene alkyl ether having at least one functional group in the molecule, polyoxyethylene phenyl ether having at least one functional group in the molecule, and sulfosuccinic acid thereof. Examples thereof include ester salts and sulfate ester salts, and further, polyoxyethylene alkylphenyl ether having at least one functional group in the molecule, its sulfosuccinic acid ester salt, its sulfate ester salt, its phosphate ester salt, and its fat. In addition to group or aromatic carboxylates, acidic phosphoric acid (meth) acrylic acid ester-based emulsifiers, acid anhydride modified products of rosing ricidyl ester acrylate (see JP-A-4-256429), JP-A-63- Examples thereof include various substances such as the emulsifiers described in JP-A-23725, JP-A-63-240931, and JP-A-62-104802. In addition, polyoxyethylene in the reactive emulsifier may be replaced with polyoxypropylene or a block copolymerization or random copolymerization of polyoxyethylene and polyoxypropylene. Examples of these commercially available products include "KAYAMER PM-1", "KAYAMER PM-2", "KAYAMER PM-21" (all manufactured by Nippon Kayaku Co., Ltd.), "SE-10N", and " "NE-10", "NE-20", "NE-30", "Adecaria Soap SR-10", "Adecaria Soap SR-20", "Adecaria Soap ER-20" (above, ADEKA Corporation) (Manufactured by), "New Frontier A229E", "New Frontier N117E", "New Frontier N250Z", "Aquaron RN-10", "Aquaron RN-20", "Aqualon RN-50", "Aquaron HS-10", " "Aqualon KH-05", "Aqualon KH-10" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), "Ereminol JS-2" (manufactured by Sanyo Chemical Industries, Ltd.), "Latemuru K-180" (Kao (Kao) (Manufactured by Co., Ltd.) is a typical example. The reactive emulsifier is preferably a polyoxyethylene alkyl ether type from the viewpoint of polymerizable property and emulsification property when emulsifying the tackifier resin of the present invention using the obtained polymer emulsifier, and has a (meth) allyl group as a molecule. It is particularly preferable to use a sulfate ester salt of a polyoxyethylene alkyl ether having at least one of them. These commercially available products include "Adecaria Soap SR-10", "Adecaria Soap SR-20" (above, manufactured by ADEKA Corporation), "Aqualon KH-05", and "Aquaron KH-10" (above, (Manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is preferable. The non-reactive emulsifier includes, for example, dialkyl sulfosuccinate, alkane sulfonate, α-olefin sulfonate, polyoxyethylene alkyl ether sulfosuccinic acid ester salt, and polyoxyethylene styrylphenyl as low molecular weight anionic emulsifiers. Examples thereof include ether sulfosuccinic acid ester salt, naphthalin sulfonic acid formalin condensate, polyoxyethylene alkyl ether sulfate ester salt, polyoxyethylene alkyl phenyl ether sulfate ester salt and the like. Examples of the low molecular weight nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene styrylphenyl ether, and polyoxyethylene sorbitan fatty acid ester. The amount of these emulsifiers used is not particularly limited, but is about 1 to 10 parts by mass, preferably about 2 to 8 parts by mass, in terms of solid content, with respect to 100 parts by mass of the tackifier resin according to the present invention. When the amount of the emulsifier used is 1 part by mass or more, reliable emulsification can be performed, and when it is 10 parts by mass or less, the initial adhesive strength is easily developed and the water resistance of the adhesive layer is secured. It is preferable in that it can be done.

The weight average molecular weight of the high molecular weight emulsifier is not particularly limited, but is usually about 1000 to 500,000.

The method for emulsifying the tackifier resin according to the present invention is not particularly limited, and examples thereof include known emulsification methods such as a high-pressure emulsification method and a phase inversion emulsification method. In the high-pressure emulsification method, after the tackifier resin is put into a liquid state, at least one emulsifier selected from the group consisting of the high molecular weight emulsifier, the reactive emulsifier and the non-reactive emulsifier and water are premixed and high-pressure emulsified. This is a method of finely emulsifying using a machine and then removing the solvent if necessary. The method of putting the tackifier resin into a liquid state may be only heating, dissolving in a solvent and then heating, or mixing a non-volatile substance such as a plasticizer and heating. Examples of the solvent include an organic solvent capable of dissolving a tackifier resin component such as toluene, xylene, methylcyclohexane, and ethyl acetate. In the phase inversion emulsification method, after the tackifier resin (tackiness-imparting agent) is heated and melted, an emulsifier and water are added while stirring to form a W / O emulsion, and then O / is formed by adding water or changing the temperature. This is a method of inversion to a W emulsion.

The solid content concentration of the tackifier resin emulsion of the present invention is not particularly limited, but is usually about 35 to 65% by mass. The particle size is not particularly limited, but the volume average particle size is usually about 0.1 to 2 μm, but from the viewpoint of storage stability, the upper limit is about 1 μm, preferably about 0.7 μm. The pH and viscosity are also not particularly limited, but are usually about 2 to 10 and about 10 to 1000 mPa · s (25 ° C., solid content concentration 50%).

The water-based adhesive composition of the present invention is a composition containing the tackifier resin and the base resin according to the present invention. Examples of the base resin include polychloroprene latex, styrene-butadiene copolymer latex, acrylic polymer emulsion, natural rubber latex, vinyl acetate emulsion, ethylene-vinyl acetate copolymer emulsion, urethane emulsion and the like. , Known ones generally used for various water-based adhesives can be used. Further, each of them can be used in combination, and if necessary, a cross-linking agent, a defoaming agent, a thickener, a filler, an antioxidant, a water resistant agent, a film-forming auxiliary and the like can be used. Further, a known tackifier resin may be used. The solid content concentration of these water-based adhesive compositions is usually about 40 to 70% by mass, preferably 55 to 70% by mass. At least one type of base resin may be used, but it is preferable to use polychloroprene latex because hydrolysis is unlikely to occur, the open time is long, reworkability is good, and handling as an adhesive is good.

The polychloroprene latex can be produced by various known methods. Specifically, a method of radical emulsion polymerization in the presence of a monomer, an emulsifier, a chain transfer agent, a polymerization catalyst, or the like is preferable in terms of industrial advantages. Examples of the emulsifier used in this case include salts of logonic acid, salts of fatty acids, alkyl sulfonates such as Na alkylbenzene sulfonate, anionic emulsifiers such as alkyl sulfate ester salts such as Na lauryl sulfate, and nonionic emulsifiers. Examples thereof include cationic emulsifiers and water-soluble polymers such as polyvinyl alcohol. The chain transfer agent is not particularly limited as long as it is generally used for producing a chloroprene polymer. For example, long-chain alkyl mercaptans such as n-dodecyl mercaptan and tert-dodecyl mercaptan, diisopropylxanthogen disulfide and diethylxanthogen. Dialkylxanthate disulfides such as disulfides and known chain transfer agents such as iodoform can be used. It is preferable to use long-chain alkyl mercaptans or dialkyl xanthogen disulfides in terms of controlling the molecular weight of the gel and the sol.

As the polymerization catalyst, persulfates such as potassium persulfate, which are usually used for emulsion polymerization of chloroprene, organic peroxides such as 3-butylhydroperoxide, and the like can be used, and are not particularly limited. Further, by using sodium anthraquinone sulfonate, formamidine sulfinic acid, etc. in combination, the polymerization reaction can proceed more smoothly. The polymerization temperature is preferably in the range of 0 to 55 ° C. in general emulsion polymerization of chloroprene in terms of polymerization control, but the gel content in the present invention is 3 to 40% by weight and the weight average molecular weight of the sol is 400,000 or more. In order to obtain the chloroprene polymer of the above, it is necessary to polymerize at a temperature lower than 30 ° C., and more preferably at a low temperature of 5 to 20 ° C. By carrying out the polymerization at a lower temperature, the gel content can be kept low and the weight average molecular weight of the sol can be increased. Further, by lowering the polymerization temperature, the 1,4-trans structure in the main chain of the chloroprene polymer is increased, and a chloroprene polymer having high crystallinity can be obtained. Crystallization of the chloroprene polymer improves the initial adhesive strength and makes it possible to obtain an adhesive layer having a high cohesive force.

As the polymerization terminator (polymerization inhibitor), for example, 2,6-terriary butyl-4-methylphenol, phenothiazine, hydroxyamine and the like can be used.

The final polymerization rate is not particularly limited and can be arbitrarily adjusted to be about 70 to 100%. Further, the unreacted monomer may be removed (demonomerized) by a known method such as heating under reduced pressure.

The toluene insoluble content (gel content) of the chloroprene polymer obtained by the above-mentioned method is preferably about 20 to 99%. Thereby, a water-based adhesive composition having an excellent balance between the initial adhesive strength and the normal adhesive strength can be obtained.

The method for producing the water-based adhesive composition of the present invention is not particularly limited, and the tackifier resin according to the present invention and / or the tackifier resin emulsion according to the present invention (hereinafter, both are referred to as "tackiness-imparting resin (emulsion)". May be mixed with the base resin, or the tackifier resin according to the present invention is added to the base resin by dissolving it in a solvent or by heating and melting it, and a high shear rotary mixer or the like is used. May be mixed.

The ratio of the tackifier resin (emulsion) to the base resin is not particularly limited, but the effect of the initial bond strength of the tackifier resin (emulsion) can be sufficiently exhibited, and the heat-resistant adhesive strength is lowered due to excessive use. As an appropriate range of use that does not cause the problem, it is preferable that the pressure-sensitive adhesive resin (emulsion) is usually about 10 to 150 parts by mass (solid content equivalent) with respect to 100 parts by mass (solid content equivalent) of the base resin.

The polychloroprene latex-based adhesive composition according to the present invention may further contain a metal oxide. The metal oxide is added to improve the water resistance and heat resistance of the adhesive. Examples of the metal oxide include zinc oxide, titanium oxide, iron oxide and the like, and two or more of them can be used in combination. Among these, zinc oxide and / or titanium oxide is particularly preferable from the viewpoint of water resistance. Further, the metal oxide can be used as it is or in an emulsion mode. The amount of the metal oxide used is not particularly limited, but is usually about 0.1 to 10 parts by mass with respect to 100 parts by mass (in terms of solid content) of the polychloroprene latex-based adhesive composition.

In the polychloroprene latex-based adhesive composition according to the present invention, a cross-linking agent, a defoaming agent, a thickener, a filler, an antioxidant, a water resistant agent, a film-forming auxiliary and the like are further used as necessary. You can also do it.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to these examples. Further, in the examples, "%" and "part" mean "mass%" and "part by mass" unless otherwise specified.

(Content of skeleton derived from dehydroabietic acid)
The content of the dehydroabietic acid-derived skeleton in the rosin ester and the rosin-modified phenol resin of each example was determined as follows. That is, each resin is dissolved in n-hexanol, potassium hydroxide is added to each solution, the mixture is refluxed for 2 hours, and then neutralized with hydrochloric acid to make it neutral. Dilute with an on-column methylating agent [0.2 molmethanol solution of phenyltrimethylammonium hydroxide (PTHA), manufactured by GL Science Co., Ltd.] so as to be mass%, and 1 μl is gas chromatograph mass spectrometry (GC / MS). It was injected into the device and measured. The content of dehydroabietic acid was determined from the peak area ratio showing methyl dehydroabietic acid in the total peak area showing methylated resinic acid. The GC / MS apparatus used is as follows.

Gas chromatograph: "Agilent 6890" (trade name, manufactured by Agilent Technologies Inc.)
Mass spectrometer: "Agilent 5973" (trade name, manufactured by Agilent Technologies Inc.)
Column: "Advance-DS" (trade name, manufactured by Shinwa Kako Co., Ltd.)

(Weight average molecular weight (Mw))
The overall weight average molecular weight (Mw) of each of the rosin ester and the rosin-modified phenol resin of each example was calculated as a polystyrene-equivalent value obtained from a calibration curve of standard polystyrene by a gel permeation chromatography (GPC) method. did. The GPC method was measured under the following conditions.
Analyzer: HLC-8120 (manufactured by Tosoh Corporation)
Column: TSKgelSuperHM-L x 3 Eluent: Tetrahydrofuran Injection sample concentration: 5 mg / mL
Flow rate: 0.6 mL / min
Injection volume: 100 μL
Column temperature: 40 ° C
Detector: RI

Next, with respect to the GPC chart obtained by the above method, the peak area ratio (%) of the component having a weight average molecular weight of 1,200 to the total peak area and the peak area ratio of the low molecular weight component having a weight average molecular weight of less than 1,200. (%) Was mechanically determined from the ratio of peak areas (%).

(Manufacturing of adhesive resin)
Manufacturing example 1
100 parts of disproportionated rosin (trade name "Londis R", manufactured by Arakawa Chemical Industries, acid value 160, softening point 70 ° C) in a reaction vessel equipped with a stirrer, condenser, thermometer and nitrogen introduction pipe / steam introduction pipe. , 8.1 parts of glycerin and 5.7 parts of diethylene glycol were charged, and then reacted at 250 ° C. for 2 hours under a nitrogen gas stream, then heated to 280 ° C. and reacted at the same temperature for 12 hours for esterification. Completed. Then, water and the like were removed under reduced pressure to obtain rosin ester 1. The values of requirements 1 to 3 are shown in Table 1 (the same applies hereinafter).

Manufacturing example 2
In the same reaction vessel as in Production Example 1, 100 parts of gum rosin (trade name "CG-WW", manufactured by Arakawa Chemical Industry Co., Ltd., acid value 160, softening point 70 ° C.), 12.9 parts of glycerin are charged, and then a nitrogen gas stream. After the reaction was carried out at 250 ° C. for 2 hours, the temperature was further raised to 280 ° C. and the reaction was carried out at the same temperature for 12 hours to complete the esterification. Then, water and the like were removed under reduced pressure to obtain rosin ester 2.

Manufacturing example 3
In the same reaction vessel as in Production Example 1, 100 parts of CG-WW, 8.5 parts of glycerin, and 5.7 parts of diethylene glycol were charged, and then reacted at 250 ° C. for 2 hours under a nitrogen gas stream, and then further 280 ° C. The temperature was raised to 12 hours at the same temperature to complete esterification. Then, water and the like were removed under reduced pressure to obtain rosin ester 3.

Manufacturing example 4
100 parts of CG-WW and 8.4 parts of maleic acid were charged in the same reaction vessel as in Production Example 1, and then reacted at 220 ° C. for 2 hours under a nitrogen gas stream, and then 1.8 parts of glycerin and penta. After 17.9 parts of erythritol was charged and reacted at 250 ° C. for 2 hours, the temperature was further raised to 280 ° C. and the reaction was carried out at the same temperature for 12 hours to complete the esterification. Then, water and the like were removed under reduced pressure to obtain rosin ester 4.

Production example 5
After charging 100 parts of rosin ester 1 and 100 parts of rosin ester 4 in the same reaction vessel as in Production Example 1, the mixture was heated to 150 ° C. and stirred to obtain rosin ester 5.

Production example 6
After charging 100 parts of rosin ester 2 and 100 parts of rosin ester 4 in the same reaction vessel as in Production Example 1, the mixture was heated to 150 ° C. and stirred to obtain rosin ester 6.

Production example 7
After charging 100 parts of rosin ester 3 and 100 parts of rosin ester 4 in the same reaction vessel as in Production Example 1, the mixture was heated to 150 ° C. and stirred to obtain rosin ester 7.

Production Example 8
In the same reaction vessel as in Production Example 1, 100 parts of CG-WW and 13.4 parts of maleic acid were charged, and then reacted at 220 ° C. for 2 hours under a nitrogen gas stream, and then 17.8 parts of glycerin was charged. After reacting at 250 ° C. for 2 hours, the temperature was further raised to 280 ° C. and the reaction was carried out at the same temperature for 12 hours to complete the esterification. Then, water and the like were removed under reduced pressure to obtain a rosin ester 8.

Manufacturing example 9
After charging 100 parts of rosin ester 1 and 25 parts of rosin ester 4 in the same reaction vessel as in Production Example 1, the mixture was heated to 150 ° C. and stirred to obtain rosin ester 9.

Production Example 10
After charging 60 parts of rosin ester 1 and 40 parts of rosin ester 4 in the same reaction vessel as in Production Example 1, the mixture was heated to 150 ° C. and stirred to obtain rosin ester 10.

Production Example 11
After charging 40 parts of rosin ester 1 and 60 parts of rosin ester 4 in the same reaction vessel as in Production Example 1, the mixture was heated to 150 ° C. and stirred to obtain rosin ester 11.

Production Example 12
100 parts of CG-WW and 10 parts of fumaric acid were charged in the same reaction vessel as in Production Example 1, and then reacted at 220 ° C. for 2 hours under a nitrogen gas stream, followed by 1.1 parts of glycerin and pentaerythritol 18. After charging 7 parts and reacting at 250 ° C. for 2 hours, the temperature was further raised to 280 ° C. and the reaction was carried out at the same temperature for 12 hours to complete the esterification. Then, water and the like were removed under reduced pressure to obtain a rosin ester. Further, 100 parts of rosin ester 1 and 100 parts of the rosin ester obtained above are charged in the same reaction vessel as in Production Example 1, and then heated to 150 ° C. and stirred to obtain rosin ester 12. It was.

Production Example 13
In the same reaction vessel as in Production Example 1, 100 parts of CG-WW and 0.5 part of fumaric acid were charged, and then reacted at 220 ° C. for 2 hours under a nitrogen gas stream, and then 12.6 parts of glycerin was charged. After reacting at 250 ° C. for 2 hours, the temperature was further raised to 280 ° C. and the reaction was carried out at the same temperature for 12 hours to complete the esterification. Then, water and the like were removed under reduced pressure to obtain a rosin ester. Further, 100 parts of the rosin ester 4 and 100 parts of the rosin ester obtained above are charged in the same reaction vessel as in Production Example 1, and then heated to 150 ° C. and stirred to obtain the rosin ester 13. It was.

Production example 14
After charging 100.0 parts of CG-WW and 100.0 parts of phenol in the same reactor as in Production Example 1, the temperature was raised to 100 ° C., 2.1 parts of 96% sulfuric acid was charged, and the reaction was carried out under a nitrogen gas stream for 3 hours. I let you. Then, after adding 3.0 parts of slaked lime, the temperature was raised to 280 ° C. under a reduced pressure of 10 kPa, and the reaction was carried out at the same temperature for 4 hours. Then, water and the like were removed to obtain a rosin-modified phenol resin.

[Preparation of adhesive resin emulsion]
Example 1
After dissolving 100 parts of the rosin ester 5 of Production Example 5 in 70 parts of toluene at 80 ° C. for 3 hours, an anionic emulsifier (Neohytenol F-13 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)) is solidified. 3 parts and 140 parts of water were added in terms of minutes, and the mixture was stirred for 1 hour. Then, a high-pressure emulsifier (manufactured by Menton Gaulin Co., Ltd.) was used to high-pressure emulsify at a pressure of 30 MPa to obtain an emulsion. Then, it was distilled under reduced pressure for 6 hours under the condition of 70 ° C. and 2.93 × 10 ⁻² MPa to obtain a tackifier resin emulsion having a solid content of 50%.

Example 2
In Example 1, the rosin ester 5 was replaced with the rosin ester 6 of Production Example 6 in the same manner, and a tackifier resin emulsion was obtained.

Example 3
In Example 1, the rosin ester 5 was replaced with the rosin ester 7 of Production Example 7 in the same manner, and a tackifier resin emulsion was obtained.

Example 4
In Example 1, the rosin ester 5 was replaced with the rosin ester 10 of Production Example 10 in the same manner, and a tackifier resin emulsion was obtained.

Example 5
In Example 1, the rosin ester 5 was replaced with the rosin ester 11 of Production Example 11 in the same manner, and a tackifier resin emulsion was obtained.

Example 6
In Example 1, the rosin ester 5 was replaced with the rosin ester 12 of Production Example 12 in the same manner, and a tackifier resin emulsion was obtained.

Example 7
In Example 1, the rosin ester 5 was replaced with the rosin ester 13 of Production Example 13 in the same manner, and a tackifier resin emulsion was obtained.

Comparative Example 1
In Example 1, the rosin ester 5 was replaced with the rosin ester 1 of Production Example 1 in the same manner, and a tackifier resin emulsion was obtained.

Comparative Example 2
In Comparative Example 1, the same procedure was carried out except that the rosin ester 1 was replaced with the rosin ester 2 of Production Example 2 to obtain a tackifier resin emulsion.

Comparative Example 3
In Comparative Example 1, the same procedure was carried out except that the rosin ester 1 was replaced with the rosin ester 3 of Production Example 3 to obtain a tackifier resin emulsion.

Comparative Example 4
In Comparative Example 1, the same procedure was carried out except that the rosin ester 1 was replaced with the rosin ester 4 of Production Example 4 to obtain a tackifier resin emulsion.

Comparative Example 5
In Comparative Example 1, the same procedure was carried out except that the rosin ester 1 was replaced with the rosin ester 8 of Production Example 8 to obtain a tackifier resin emulsion.

Comparative Example 6
In Comparative Example 1, the same procedure was carried out except that the rosin ester 1 was replaced with the rosin ester 9 of Production Example 9 to obtain a tackifier resin emulsion.

Comparative Example 7
In Comparative Example 1, the same procedure was carried out except that the rosin ester 1 was replaced with the rosin-modified phenol resin of Production Example 14, to obtain a tackifier resin emulsion.

(Manufacturing of polychloroprene latex)
In the same reaction vessel as in Production Example 1, 100 parts by mass of water, 3.0 parts by mass of methacrylic acid, 0.1 parts by mass of sodium sulfite, and nonionic surfactant (polyoxyethylene oleyl ether, Kao stock) under a nitrogen stream. Emargen (registered trademark) 430, HLB: 16.2, molecular weight: 1570) manufactured by the company was charged in an amount of 0.5 parts by mass, and after dissolution, 97 parts by mass of chloroprene and 0.3 parts by mass of n-octyl mercaptan were added with stirring. .. Using potassium persulfate as an initiator, polymerization was carried out at 40 ° C. under a nitrogen atmosphere, and when the polymerization rate reached 95%, an emulsion of phenothiazine was added to terminate the polymerization. After removing the unreacted monomer under reduced pressure, water was further evaporated under reduced pressure to concentrate the mixture to obtain a polychloroprene latex having a solid content concentration of 50%.

(Preparation of water-based adhesive composition)
Evaluation example 1
100 parts of the polychloroprene latex (in terms of solid content) and 50 parts of the tackifier resin emulsion of Example 1 (in terms of solid content) are mixed, and a zinc oxide emulsion (trade name AZ-SW, solid content 50) is further used as a metal oxide. %, 1 part of Osaki Kogyo Co., Ltd. and 1 part of Adecanol UH-526 (water-soluble polyurethane thickener, solid content 30%, manufactured by ADEKA Co., Ltd.) were added to obtain a water-based adhesive composition. ..

Evaluation example 2
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of that of Example 2 was used as the tackifier resin emulsion.

Evaluation example 3
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of that of Example 3 was used as the tackifier resin emulsion.

Evaluation example 4
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of that of Example 4 was used as the tackifier resin emulsion.

Evaluation example 5
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of Example 5 was used as the tackifier resin emulsion.

Evaluation example 6
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of Example 6 was used as the tackifier resin emulsion.

Evaluation example 7
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of Example 7 was used as the tackifier resin emulsion.

Comparative evaluation example 1
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of that of Comparative Example 1 was used as the tackifier resin emulsion.

Comparative evaluation example 2
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of Comparative Example 2 was used as the tackifier resin emulsion.

Comparative evaluation example 3
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of Comparative Example 3 was used as the tackifier resin emulsion.

Comparative evaluation example 4
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of Comparative Example 4 was used as the tackifier resin emulsion.

Comparative evaluation example 5
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of Comparative Example 5 was used as the tackifier resin emulsion.

Comparative evaluation example 6
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of Comparative Example 6 was used as the tackifier resin emulsion.

Comparative evaluation example 7
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of Comparative Example 7 was used as the tackifier resin emulsion.

Comparative evaluation example 8
In Evaluation Example 1, a water-based adhesive composition was obtained in the same manner except that 50 parts (in terms of solid content) of a terpene phenol resin emulsion (trade name: DERMULSENE TR 602) manufactured by France DRT was used as the tackifying resin emulsion. ..

(Preparation of test piece)
The water-based adhesive composition according to Evaluation Example 1 was applied to each of two canvases (25 x 150 mm) ^{with a brush so as to have a concentration of 300 g (solid content) / m 2} , dried in an atmosphere of 80 ° C. for 9 minutes, and 1 at room temperature. After leaving for a minute, the coated surfaces were bonded and crimped with a hand roller.

(Initial adhesive strength)
After being left for 10 minutes after crimping, a 180 ° peel strength was measured at a tensile speed of 200 mm / min using a tensile tester (product name: TENSILON RTC-1250A, manufactured by ORIENTEC). The measured values are shown in Table 2.

(Normal adhesive strength)
After being left to stand for 7 days after crimping, 180 ° peel strength was measured at a tensile speed of 200 mm / min using the above tensile tester. The measured values are shown in Table 2.

(Heat-resistant adhesive strength)
After being left to stand for 7 days after crimping, a load of 500 g was applied in an atmosphere of 50 ° C. using a creep tester (product name: creep tester, manufactured by Tester Sangyo), and the peeling distance after 24 hours was measured. When the total peeling was performed within 24 hours, the time was measured. The measured values are shown in Table 2.

Test pieces were similarly prepared for the water-based adhesive compositions according to the other examples and comparative examples, and the initial adhesive strength, normal adhesive strength, and heat-resistant adhesive strength were evaluated. The measured values are shown in Table 2.

Claims (7)

A tackifier resin comprising a rosin ester which is a reaction product of (A) rosin, (B) α, β unsaturated carboxylic acid-modified rosin, and (C) alcohol and satisfies the following requirements 1 and 2.
Requirement 1: The content of the skeleton derived from dehydroabietic acid is 20% by mass or more Requirement 2: The peak area (S2) of the component having a weight average molecular weight of 1,200 or more with respect to the total peak area (S1) measured by gel permeation chromatography. ) Is 20-50% The tackifier resin according to claim 1, wherein the component (A) is natural rosin and / or disproportionated rosin. The tackifier resin according to claim 1 or 2, wherein the α, β unsaturated carboxylic acid constituting the component (B) is fumaric acid and / or maleic acid. The tackifier resin according to any one of claims 1 to 3, wherein the component (C) is at least one selected from the group consisting of dihydric alcohols, trihydric alcohols and tetrahydric alcohols. A tackifier resin emulsion which is an emulsion of the tackifier resin according to any one of claims 1 to 4. A water-based adhesive composition containing the tackifier resin emulsion and the base resin according to claim 5. A polychloroprene latex-based adhesive composition containing the tackifier resin emulsion and polychloroprene latex according to claim 5.