JP4597607B2 - Aqueous adhesive composition and method for producing the same - Google Patents

Description

  The present invention relates to a water-based adhesive composition, and more particularly to a water-based adhesive composition excellent in initial adhesive strength and heat resistance used for bonding urethane foam, cloth materials, skin materials, foam sheets, wood, and the like, and a method for producing the same. .

  A polychloroprene solvent adhesive has been used for bonding urethane foam and the like. However, in recent years, when solvent-based adhesives are produced or used, there are problems such as fire hazard and environmental pollution due to organic solvents, and the demand for solvent removal is increasing.

As a method for removing the solvent, it is considered effective to replace the solvent-type adhesive with a latex adhesive, and studies on latex adhesives using various polymers have been actively conducted.
On the other hand, polychloroprene-based water-based adhesives are being investigated in place of polychloroprene-based solvent-based adhesives, but since a long drying time is required, it takes time to bond after applying the adhesive. In addition, there is a problem that special drying equipment is required to shorten the drying time.

Patent Document 1 discloses a water-based adhesive obtained by blending an acrylic emulsion with polychloroprene latex. However, improvement of initial adhesion performance has been a problem for conventional aqueous adhesives.
JP-A-10-195406 (2nd and 7th pages)

  This invention is made | formed in view of such a background art, and provides the aqueous adhesive composition excellent in the initial stage adhesive force and heat resistance, and its manufacturing method.

  As a result of intensive studies to solve the above problems, the inventors of the present application have obtained two types of polymers obtained by polymerizing chloroprene monomer or chloroprene and a monomer copolymerizable with chloroprene in different emulsion systems. The present inventors have found that a water-based adhesive containing a latex is excellent in initial adhesive strength and heat resistance, and completed the present invention.

That is, the present invention is obtained by emulsion polymerization of 100 parts by mass of chloroprene monomer or chloroprene and a monomer copolymerizable with chloroprene in the presence of 2 to 8 parts by mass of an emulsifier containing a rosin acid alkali salt. 100 to 100 parts by mass of the polychloroprene latex A and chloroprene monomer or chloroprene and a monomer copolymerizable with chloroprene is 0.5 to 15 parts by mass of a nonionic emulsifier represented by the following general formula (1) A water-based adhesive composition containing polychloroprene latex B obtained by emulsion polymerization in the presence of water, and 1 part of polychloroprene latex B with respect to 100 parts by mass (solid content) of polychloroprene latex A. It is a water-based adhesive composition characterized by containing in the ratio of -40 mass parts (solid content) .

(In the formula, R represents a hydrophobic group having at least one selected from an optionally substituted benzene ring and naphthalene ring. R ₁ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. N Represents an integer of 1 to 200.)

In addition, the present invention provides polychloroprene by emulsion polymerization of a total of 100 parts by mass of a chloroprene monomer or a monomer copolymerizable with chloroprene and chloroprene in the presence of 2 to 8 parts by mass of an emulsifier containing a rosin acid alkali salt. A step of obtaining latex A, a total of 100 parts by mass of chloroprene monomer or chloroprene and a monomer copolymerizable with chloroprene is 0.5 to 15 parts by mass of a nonionic emulsifier represented by the above general formula (1). obtaining a polychloroprene latex B by emulsion polymerization in the presence, the polychloroprene latex B and the polychloroprene latex a, the polychloroprene latex A100 parts by weight with respect to (the solid content), the polychloroprene latex B 1 It is characterized by having a step of mixing at a ratio of 40 parts by weight (solid content) A method for producing a water-based adhesive composition.

  The water-based adhesive composition of the present invention is excellent in initial adhesive strength and heat resistance, and has a good balance between adhesion and heat resistance, so urethane foam, cloth material, skin material, foam sheet, paper material, wood, It is particularly suitable for bonding shoe parts and the like.

In the aqueous adhesive composition of the present invention, 100 parts by mass of a chloroprene monomer or a monomer copolymerizable with chloroprene and chloroprene is subjected to emulsion polymerization in the presence of 2 to 8 parts by mass of an emulsifier containing an rosin acid alkali salt. Nonionic emulsifier represented by the general formula (1) 0.5 to 15 in total of 100 parts by mass of the polychloroprene latex A obtained in this way and the chloroprene monomer or the monomer capable of copolymerization with chloroprene and chloroprene An aqueous adhesive composition containing polychloroprene latex B obtained by emulsion polymerization in the presence of parts by mass , and the polychloroprene latex B with respect to 100 parts by mass (solid content) of the polychloroprene latex A Is contained at a ratio of 1 to 40 parts by mass (solid content) .

  Furthermore, the present invention is preferably formed by blending a pH adjuster, and by blending the pH adjuster, a water-based adhesive composition having better initial adhesive strength can be obtained.

Monomers that can be copolymerized with chloroprene include, for example, ethylenically unsaturated carboxylic acid, acrylic acid esters, methacrylic acid esters, 2,3-dichloro-1,3-butadiene, and 1-chloro. -1,3-butadiene, butadiene, isoprene, styrene, acrylonitrile and the like can be mentioned, and two or more kinds can be used as necessary.
In polychloroprene latex B, acrylic acid and methacrylic acid are preferably used as monomers capable of copolymerization with chloroprene, and methacrylic acid is particularly preferably used.

  The amount of the ethylenically unsaturated carboxylic acid added is preferably 0.3 to 10% by mass and more preferably 1 to 5% by mass in the copolymer. When the addition amount of the ethylenically unsaturated carboxylic acid exceeds 10% by mass, the water resistance of the water-based adhesive composition is deteriorated, and when it is less than 0.3% by mass, the mechanical stability of the polychloroprene latex B is decreased. Gets worse.

  Although it does not specifically limit as rosin acid alkali salt, For example, it is preferable to use sodium salts and / or potassium salts, such as gum rosin, tall rosin, and wood rosin. These can be used alone or in combination of two or more.

  The addition amount of the rosin acid alkali salt is in the range of 2 to 8 parts by mass, preferably 3 to 7 parts by mass with respect to 100 parts by mass of chloroprene monomer or chloroprene and monomers copolymerizable with chloroprene. . If it is less than 2 parts by mass, the storage stability of the obtained polychloroprene latex A is poor, and if it exceeds 8 parts by mass, the initial adhesive performance of the aqueous adhesive composition is deteriorated.

  Nonionic emulsifiers include compounds represented by general formula (1).

In the general formula (1), R represents a hydrophobic group having at least one selected from a benzene ring and a naphthalene ring which may be substituted. R ₁ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. n represents an integer of 1 to 200.

  Specific examples of the substituent R include hydrophobic groups having structures represented by the following (I) to (XIII). These hydrophobic groups may be a mixture.

However, in the above formula indicates the R _2, R _3, R ₄ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R ₅ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group, or a hydroxyl group.

  Nonionic emulsifiers represented by the general formula (1) are, for example, polyoxyethylene styryl phenyl ether, polyoxyethylene distyryl phenyl ether, polyoxyethylene tristyryl phenyl ether, polyoxyethylene styryl cresyl ether, polyoxyethylene diester Styryl cresyl ether, polyoxyethylene tristyryl cresyl ether, polyoxyethylene styryl hydroxyphenyl ether, polyoxyethylene distyryl hydroxyphenyl ether, polyoxyethylene tristyryl hydroxyphenyl ether, polyoxyethylene naphthyl ether, polyoxyethylene hydroxy naphthyl ether And polyoxyethylene cresyl naphthyl ether. Preferably, polyoxyethylene styryl phenyl ether, polyoxyethylene distyryl phenyl ether or polyoxyethylene tristyryl phenyl ether is used. Moreover, these may be used as a mixture.

  The HLB value of the nonionic emulsifier is an index indicating the balance between hydrophilicity and hydrophobicity devised by Mr. Griffin of ICI, USA, and is a numerical value of 1 to 20 calculated according to the following formula (2). The higher the HLB value, the higher the hydrophilicity, and the lower the HLB value, the higher the lipophilicity.

  The HLB value of the nonionic emulsifier is 9 or more, preferably 12 or more and 19 or less. Outside this range, stable polymerization of the chloroprene monomer becomes difficult.

  The addition amount of the nonionic emulsifier is 0.5 to 15 parts by mass, preferably 1 to 7 parts by mass with respect to 100 parts by mass of chloroprene monomer or chloroprene and monomers copolymerizable with chloroprene. . When the amount is less than 0.5 parts by mass, polymerization of the polychloroprene latex B becomes difficult. When the amount exceeds 15 parts by mass, the adhesiveness of the aqueous adhesive composition is deteriorated.

  The nonionic emulsifier of the polychloroprene latex B includes, for example, polyoxyalkylene alkyl ether, polyoxyalkylene alkyl allyl ether, polyoxyalkylene sorbitan ether, polyoxyethylene, in addition to those having the structure represented by the general formula (1). Polyoxyethylene derivatives such as castor oil ether, sorbitan fatty acid esters such as sorbitan monostearate, sorbitan monolaurate, sorbitan monopalmitate, glycerol fatty acid esters such as glycerol monostearate and glycerol monooleate, aliphatic Alkanolamines and the like can be used as necessary.

  An emulsifier auxiliary component can be used in the polychloroprene latex A and the polychloroprene latex B. As an emulsifier auxiliary component, for example, a metal salt of an aromatic sulfonic acid formalin condensate is used. Specific examples include lithium salts, sodium salts, potassium salts, cesium salts, and the like of β-naphthalene sulfonic acid formalin condensate, among which sodium salts or potassium salts are preferred.

  The metal salt of the aromatic sulfonic acid formalin condensate as an auxiliary component of the emulsifier is used for the purpose of stabilizing the polymerization behavior of the polychloroprene latex and improving the storage stability of the polychloroprene latex and the aqueous adhesive.

  The amount of the emulsifier auxiliary component added is 0.05 to 0.5 parts by mass, preferably 0.08 to 0.005 parts per 100 parts by mass in total of the chloroprene monomer or chloroprene and monomers copolymerizable with chloroprene. 4 parts by mass. If the amount is less than 0.05 parts by mass, the effect of stabilizing the polymerization behavior and storage stability of the polychloroprene latex is not observed. If the amount exceeds 0.5 parts by mass, the polymerization behavior of the polychloroprene latex becomes difficult to control. .

  Polychloroprene Latex A is an emulsion polymerized chloroprene monomer or a monomer copolymerizable with chloropre and chloroprene, an emulsifier containing rosin acid alkali salt, an emulsifier auxiliary component, etc. in an aqueous solution in the presence of a catalyst and a reducing agent. Can be obtained.

  The polychloroprene latex B comprises a chloroprene monomer or a monomer copolymerizable with chloropre and chloroprene, a nonionic emulsifier represented by the general formula (1), an emulsifier auxiliary component, etc. in an aqueous solution, a catalyst and a reducing agent. It can be obtained by emulsion polymerization in the presence.

The amount of pure water used for the polymerization of polychloroprene latex A and polychloroprene latex B is not particularly limited, but usually 100 masses of chloroprene monomer or chloroprene and monomers copolymerizable with chloroprene. What is necessary is just to use 50-300 mass parts per part.
Examples of the catalyst used for the polymerization of polychloroprene latex A and polychloroprene latex B include, for example, inorganic peroxides such as potassium persulfate, ketone peroxides, peroxyketals, hydroperoxides, and dialkyl peroxides. And organic peroxides such as diacyl peroxides.

Among these catalysts, it is preferable to use potassium persulfate because stable polymerization can be performed. Moreover, it is preferable to use potassium persulfate by 0.1-5 mass% aqueous solution.
In order to enhance the activity of the catalyst used for the polymerization of polychloroprene latex, for example, sodium sulfite, potassium sulfite, iron (II) oxide, anthraquinone β sodium sulfonate, formamidine sulfonic acid, L-ascorbic acid and the like are added. be able to.

  The gel content of polychloroprene latex A and polychloroprene latex B, that is, the content of components insoluble in toluene, is not particularly limited and can be arbitrarily changed according to the required characteristics. When the initial adhesive strength of the aqueous adhesive composition is more important, the gel content is preferably suppressed to 30% by mass or less, more preferably 1 to 20% by mass, and further preferably 2 to 15% by mass. Is good.

  The weight average molecular weight of the sol in the polychloroprene latex A and polychloroprene latex B, that is, the weight average molecular weight of the component soluble in toluene is not particularly limited and can be arbitrarily changed according to the required characteristics. In addition, when importance is attached to the heat resistance of the water-based adhesive composition, the weight average molecular weight of the sol is preferably adjusted to be 400,000 or more, and more preferably adjusted to be 450,000 to 1,000,000. Good.

  Regarding the control of the weight average molecular weight and gel content of the sols of these polychloroprene latex A and polychloroprene latex B, (1) addition and addition amount of chain transfer agent, (2) polymerization temperature and (3) polymerization rate It can be arbitrarily performed by the control.

  The chain transfer agent is not particularly limited as long as it is generally used in the production of chloroprene polymers. For example, long chain alkyl mercaptans such as n-dodecyl mercaptan and tert-dodecyl mercaptan n-octyl mercaptan, diisopropyl xanthogen Known chain transfer agents such as dialkylxanthogen disulfides such as disulfide and diethylxanthogen disulfide, and iodoform can be used.

The polymerization temperature is preferably in the range of 0 to 55 ° C. for polymerization control. In order to perform the polymerization reaction more smoothly and safely, the polymerization temperature is preferably 10 to 45 ° C.
When the gel content of the polychloroprene latex A and the polychloroprene latex B is controlled to be 30% by mass or less and the weight average molecular weight of the sol is adjusted to be 400,000 or more, the polymerization is preferably performed at a temperature lower than 30 ° C. It is more preferable to carry out the polymerization at a low temperature of 5 to 20 ° C.

  The polymerization rate is preferably 60% or more. When the gel content of the polychloroprene latex A and the polychloroprene latex B is controlled to 30% by mass or less and the weight average molecular weight of the sol is adjusted to be 400,000 or more, the polymerization rate should be in the range of 80 to 95%. Is preferred.

  In order to stop polymerization of polychloroprene latex A and polychloroprene latex B, for example, thiodiphenylamine, diethylhydroxylamine, hydroquinone, pt-butylcatechol, 1,3,5-trihydroxybenzene, hydroquinone methyl ether, 2 , 6-Di-t-butyl-4-methylphenol, 2,2-methylenebis (6-t-4-methylphenol), 4,4-butylenebis (6-t-butyl-3-methylphenol), ethylenebis (Oxyethylene) bis [3- (5-t-butyl-4-hydroxy-m-tolyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythritol Tetrakis [3- (3,5-di-t-butyl- - may be added a polymerization inhibitor such as hydroxyphenyl) propionate].

  The solid content concentration of the polychloroprene latex A and the polychloroprene latex B is preferably in the range of 40 to 65% by mass, more preferably in the range of 45 to 60% by mass. By setting a higher solid content concentration, the drying speed is fast and the latex has an excellent initial adhesiveness. The solid content concentration can be adjusted by the ratio of the monomer and pure water during polymerization, but it can also be adjusted by concentration after polymerization. Examples of the concentration method include, but are not limited to, vacuum concentration and the like.

  Polychloroprene latex A and polychloroprene latex B include, for example, basic substances such as diethanolamine and triethanolamine, sodium carbonate, potassium carbonate, trisodium phosphate, disodium hydrogen phosphate, phosphoric acid 3 as pH adjusters. The pH can be freely adjusted by adding weak acid salts such as potassium, dipotassium hydrogen phosphate, tripotassium citrate, dipotassium hydrogen citrate, sodium acetate, potassium acetate, and sodium borate.

  The polychloroprene latex A can be added with a low-temperature stabilizer such as diethanolamine, triethanolamine and a nonionic emulsifier after polymerization.

The aqueous adhesive composition of the present invention is obtained by blending polychloroprene latex A and polychloroprene latex B obtained by these emulsion polymerizations.
The proportion of polychloroprene latex A and polychloroprene latex B contained in the aqueous adhesive composition is 1 to 40 parts by mass of polychloroprene latex B, preferably 100 parts by mass of polychloroprene latex A in terms of solid content. Is preferably 5 to 30 parts by mass. If the polychloroprene latex B is less than 1 part by mass, the effect of improving the heat resistance of the aqueous adhesive composition cannot be obtained, and if it exceeds 40 parts by mass, the effect of improving the initial adhesive strength cannot be obtained.

  The solid content concentration of the aqueous adhesive composition is preferably in the range of 30 to 70% by mass, more preferably in the range of 40 to 65% by mass. By setting it as a higher solid content concentration, the drying speed and the initial adhesiveness can be improved. The solid content concentration may be adjusted in advance at the time of polymerization of the polychloroprene latex A and the polychloroprene latex B, but may be adjusted by concentration after blending them. Examples of the concentration method include, but are not limited to, vacuum concentration and the like.

The viscosity of the aqueous adhesive composition is preferably in the range of 5 to 3000 mPa · s at 30 ° C., more preferably in the range of 10 to 1000 mPa · s.
The pH of the aqueous adhesive composition is preferably in the range of 7.0 to 10.0 from the viewpoint of increasing the initial adhesive force. Adjustment of pH can be performed using pH adjusters, such as glycine, alanine, phenylalanine, and glutamic acid, for example. Among these pH adjusters, glycine is preferable in terms of handling.

The method for adding the pH adjusting agent is not particularly limited, and the pH adjusting agent powder can be added directly or diluted to an arbitrary ratio with pure water.
The addition method of the pH adjuster may be added after adding to one or both of the polychloroprene latex A and the polychloroprene latex B, or after adding the polychloroprene latex A and the polychloroprene latex B.

  In addition, when adding a pH adjuster only to polychloroprene latex A, the order which mixes polychloroprene latex B after adding a pH adjuster to polychloroprene latex A is preferable.

  In the aqueous adhesive composition of the present invention, a plasticizer may be added to polychloroprene latex A and / or polychloroprene latex B for the purpose of extending the pot life. Although the kind of plasticizer is not limited, for example, dioctyl adipate, dioctyl azate, oleic acid butyl ester, dioctyl phthalate, dibutyl phthalate, dibutyl sebacate (DBS), tricresyl phosphate, paraffinic oil, Examples thereof include naphthenic oil, aroma oil, glycerin and olive oil. The addition amount of the plasticizer is preferably in the range of 3 to 20 parts by mass with respect to 100 parts by mass of the polychloroprene latex A and / or polychloroprene latex.

  Examples of aqueous adhesive compositions include adhesives such as rosin ester resins, hydrogenated rosin resins, polymerized rosin resins, α-pinene resins, β-pinene resins, terpene phenol resins, coumarone-indene resins, and aliphatic hydrocarbon resins. An imparting resin, an elastomer such as acrylic rubber, polyurethane, polyolefin, or SBR can be added.

  Further, the aqueous adhesive composition includes, for example, metal oxides such as zinc oxide, titanium oxide, aluminum oxide, magnesium oxide or iron oxide, inorganic fillers such as calcium carbonate, silica, talc or clay, and polyacrylic acid. Thickeners such as sodium, water-soluble polyurethane, methylcellulose, polyoxyalkylene alkyl ether, 1: 2 mol type aliphatic alkanolamide, 1: 1 mol type diethanolamine, polyoxyethylene stearate, emulsifier such as poval, isopropyl xanthogenic acid Vulcanization accelerators such as zinc, ethylenethiourea, and tetrathiuram disulfide, preservatives, various anti-aging agents, ultraviolet absorbers, antioxidants, and the like can be optionally blended as necessary.

  The water-based adhesive composition is made by mixing polychloroprene latex A and polychloroprene latex B, a pH adjuster, etc., but the mixing apparatus is not particularly limited, such as a three-one motor, a homogenizer media mill, a colloid mill, etc. Any known device can be used.

  The water-based adhesive composition of the present invention can be used for the same or different types of joints such as paper, wood, cloth, leather, jersey, leather, leather, rubber, plastic, foam, earthenware, glass, mortar, cement-based material, ceramic, and metal. Suitable as an adhesive for bonding. In particular, when one surface is a porous adherend such as paper, wood, cloth, leather, leather, foam, etc., the adhesive performance in a wet state is excellent.

  In addition, regarding the construction method at the time of bonding, brush coating, trowel coating, spray coating, roll coater coating, and the like are possible.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but these examples do not limit the present invention. In the following examples, “part” and “%” are based on mass unless otherwise specified.
First, polychloroprene latexes A-1, A-2, B-1 and B-2 were prepared according to the following Experimental Examples 1 to 4.

[Experimental Example 1]
Production of polychloroprene latex A-1 Using a reactor with an internal volume of 3 liters, 100 parts of pure water, 5 parts of sodium rosinate, 0.5 parts of potassium hydroxide, formaldehyde naphthalenesulfonic acid condensate under a nitrogen stream 0.3 part of sodium salt and 0.3 part of sodium hydrogen sulfite were charged, and after dissolution, 100 parts of chloroprene monomer and 0.1 part of n-dodecyl mercaptan were added with stirring. Polymerization was carried out at 10 ° C. in a nitrogen atmosphere using 0.1 part by weight of potassium persulfate as an initiator. When the final polymerization rate reached 80%, an emulsion of phenothiazine was added to terminate the polymerization. After removing the unreacted monomer under reduced pressure, 0.3 part of polyoxyalkylene alkyl ether as a low temperature stabilizer was added to 100 parts of solid content while stirring. Further, the water was evaporated under reduced pressure to perform concentration, and the solid content concentration was adjusted to 55% by mass to obtain polychloroprene latex A-1.

[Experiment 2]
Production of polychloroprene latex B-1 Using a reactor having an internal volume of 3 liters, under a nitrogen stream, 100 parts of pure water and a polyoxyalkylene nonionic emulsifier (1) (Newcol 714: Nippon Emulsifier Co., Ltd., HLB value = 15) ) 5.0 parts of β-naphthalenesulfonic acid formalin condensate sodium salt solid (Demol N: manufactured by Kao Co., Ltd.), 0.3 parts, dissolved, then stirred with stirring, 97 parts of chloroprene monomer, methacrylic acid 3 parts and 0.3 part octyl mercaptan were added. While maintaining this at 40 ° C., potassium persulfate and sodium sulfite were used as initiators, and when the final polymerization rate reached 95%, an emulsion of thiodiphenylamine was added to stop the polymerization, The reaction monomer was removed.

  Next, 10 parts of 20% diethanolamine was added to the polychloroprene latex to adjust the pH to neutral, and then the water was evaporated under reduced pressure for concentration. The solid content concentration was 50% by mass. To obtain a polychloroprene latex B-1.

[Experiment 3]
Production of polychloroprene latex A-2 Using a reactor having an internal volume of 3 liters, under a nitrogen stream, 100 parts of pure water, 5 parts of sodium rosinate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium hydroxide Then, 0.3 part of sodium salt of formaldehyde naphthalenesulfonic acid condensate and 0.3 part of sodium bisulfite were charged, and after dissolution, 100 parts of chloroprene monomer and 0.14 part of n-dodecyl mercaptan were added with stirring. Polymerization was carried out at 15 ° C. in a nitrogen atmosphere using 0.1 part by weight of potassium persulfate as an initiator. When the final polymerization rate reached 90%, an emulsion of phenothiazine was added to terminate the polymerization. After removing the unreacted monomer under reduced pressure, 0.3 part of polyoxyalkylene alkyl ether as a low temperature stabilizer was added to 100 parts of solid content while stirring. Furthermore, the water was evaporated under reduced pressure and concentrated to adjust the solid content concentration to 55% by weight to obtain polychloroprene latex A-2.

[Experimental Example 4]
Production of polychloroprene latex B-2 Nonionic emulsifier (1) of polychloroprene latex B-1 was added to 4.5 parts by weight of nonionic emulsifier (2) (New Coal 710; manufactured by Nippon Emulsifier Co., Ltd., HLB value = 13) (3) (Neugen EA197; manufactured by Daiichi Kogyo Seiyaku Co., Ltd., HLB value = 18) A polychloroprene latex B-2 was produced in the same manner as in Experimental Example 2, except that the amount was changed to 0.8 parts by mass.

The following measurements were performed on these polychloroprene latexes A-1, A-2, B-1 and B-2. The results are shown in Table 1.
[Measurement of gel content]
Each sample was freeze-dried, and its mass was precisely weighed to be X. This was dissolved in toluene (prepared to 0.6%), and after using a centrifuge, the gel content was separated using a 200 mesh wire mesh. The separated gel was air-dried and then dried in an atmosphere at 110 ° C. for 1 hour.

  The gel content was calculated by the following formula (3).

[Measurement of molecular weight of sol]
GPC measurement was performed under the following conditions. The molecular weight was calculated in terms of polystyrene. The measurement was performed by preparing the sol separated by the gel content measurement into a 0.1% THF solution.

Measuring device: HLC-8120GPC manufactured by Tosoh Corporation
Column for analysis: TOS-GEL GMH _HR- H (5 μm) x 3 manufactured by Tosoh Corporation
Size 7.8mmφ × 300mm
Guard column: guard column TSK-guard column H _HR -H (5 μm)
Size 6mmφ × 40mm
Column temperature: 40 ° C
Solvent: THF special grade, flow rate: 1 ml / min

Example 1
Using 90 parts by mass of the polychloroprene latex A-1 obtained above, 5 parts by mass of glycine and 10 parts by mass of polychloroprene latex B-1 were blended using a three-one motor, and an aqueous adhesive A composition was prepared.

Example 2
In Example 1, 70 parts by mass of polychloroprene latex A-1 was blended using a three-one motor in a ratio of 4 parts by mass of glycine and 30 parts by mass of polychloroprene latex B-1, and an aqueous adhesive composition A product was made.

Example 3
A water-based adhesive composition was prepared in the same manner as in Example 1 except that polychloroprene latex A-2 was used instead of polychloroprene latex A-1 in Example 1.

Example 4
A water-based adhesive composition was produced in the same manner as in Example 3 except that polychloroprene latex B-2 was used instead of polychloroprene latex B-1 in Example 3.

Comparative Example 1
A water-based adhesive composition was prepared using only polychloroprene latex A-1.

Comparative Example 2
A water-based adhesive composition was prepared using only polychloroprene latex B-1.
The adhesiveness of the aqueous adhesive compositions obtained in the above examples and comparative examples was evaluated. The results are shown in Table 2.

[Initial adhesive strength]
A urethane foam having a density of 30 kg / m ³ (thickness 20 mm × length 50 mm × width 50 mm) is used as an adherend, and an aqueous adhesive composition is 70 g / m ^{2 in} a 23 ° C. atmosphere.
It was sprayed so that After the coating, after leaving in an atmosphere of 23 ° C. for 1 minute, the adhesive surfaces of the two urethane foams were overlapped with each other in an undried state, and the thickness was compressed to 10 mm and held for 5 seconds. Immediately thereafter, a tensile test was performed in a direction perpendicular to the bonding surface with a tensile tester (manufactured by Shimadzu Corporation Autograph; tensile speed 200 mm / min), and the initial adhesive strength was measured.

[Heat resistance test]
FIG. 1 is an explanatory view schematically showing a heat resistance test method for an aqueous adhesive composition.
As shown in FIG. 1 (a), a urethane foam having a density of 30 kg / m ³ (thickness 50 mm × length 100 mm × width 100 mm) is used for the adherend 1 and one surface of the adherend 1 has a 23 ° C. atmosphere. The aqueous adhesive composition 2 was spray-applied at a pressure of 70 g / m ² and left in a 23 ° C. atmosphere for 1 minute. After leaving, as shown in FIG. 1 (b), the surfaces coated with the aqueous adhesive composition were bonded together so that they were folded inward, and left in a 70 ° C. atmosphere for 4 hours. The state after standing was visually observed, and as shown in FIG. 1 (c), the case where the adhesive state was maintained was evaluated as ◯, and the case where the adhesive surface was opened was evaluated as ×.

[Measurement of pH]
The pH of the aqueous adhesive composition was measured with a pH meter (manufactured by Horiba, Ltd.).
(Measurement of viscosity)
The viscosity of the aqueous adhesive composition was measured at 25 ° C. and 30 rpm using a Brookfield viscometer.

  The water-based adhesive composition of the present invention is the same or different kind of paper, wood, cloth, leather, jersey, leather, leather, rubber, plastic, foam, earthenware, glass, mortar, cement-based material, ceramic, metal, etc. It can be used as a bonding adhesive.

It is explanatory drawing which showed typically the heat resistance test method of an aqueous adhesive composition.

Explanation of symbols

1 Adherent 2 Water-based adhesive composition

Claims (9)

A polychloroprene latex A obtained by emulsion polymerization of chloroprene monomer or chloroprene and a monomer copolymerizable with chloroprene in the presence of 2 to 8 parts by weight of an emulsifier containing an alkali salt of rosin acid; , 100 parts by mass of chloroprene monomer or chloroprene and a monomer copolymerizable with chloroprene in the presence of 0.5 to 15 parts by mass of a nonionic emulsifier represented by the following general formula (1) 1 to 40 parts by mass (solids) of the polychloroprene latex B with respect to 100 parts by mass (solid content) of the polychloroprene latex A. A water-based adhesive composition characterized in that it is contained at a ratio of min) .

(In the formula, R represents a hydrophobic group having at least one selected from an optionally substituted benzene ring and naphthalene ring. R ₁ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. N Represents an integer of 1 to 200.)   The aqueous adhesive composition according to claim 1, further comprising a pH adjuster. The aqueous adhesive composition according to claim 2, wherein the pH adjuster is glycine.   Furthermore, a plasticizer is contained, The water-based adhesive composition of any one of Claims 1-3 characterized by the above-mentioned. 5. The aqueous adhesive composition according to claim 1, wherein R in the general formula (1) is a hydrophobic group containing one or more styrene structures. When emulsion polymerization of at least one of the polychloroprene latex A and the polychloroprene latex B, the total weight per 100 parts by weight of the monomer, further containing 0.05 to 0.5 parts by weight of an emulsifier auxiliary component The water-based adhesive composition according to any one of claims 1 to 5, wherein The water-based adhesive according to any one of claims 1 to 5, wherein the polychloroprene latex B contains 0.3 to 10% by mass of an ethylenically unsaturated carboxylic acid in the copolymer. Composition. The water-based adhesive composition according to claim 7, wherein the ethylenically unsaturated carboxylic acid is methacrylic acid, acrylic acid or a mixture thereof. A step of obtaining a polychloroprene latex A by emulsion polymerization of chloroprene monomer or chloroprene and a monomer copolymerizable with chloroprene in the presence of 2 to 8 parts by weight of an emulsifier containing a rosin acid alkali salt; 100 parts by mass of chloroprene monomer or chloroprene and a monomer copolymerizable with chloroprene are emulsion-polymerized in the presence of 0.5 to 15 parts by mass of a nonionic emulsifier represented by the following general formula (1). obtaining a polychloroprene latex B Te, the polychloroprene latex B and the polychloroprene latex a, the polychloroprene latex A100 parts by weight with respect to (the solid content), the polychloroprene latex B 1-40 parts by weight (solid water-based adhesive composition, characterized in that it comprises the step of mixing at a rate of minute) The method of production.

(In the formula, R represents a hydrophobic group having at least one selected from an optionally substituted benzene ring and naphthalene ring. R ₁ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. N Represents an integer of 1 to 200.)

Images