TW201638269A - Latex composition and one-pack aqueous adhesive - Google Patents

Abstract

Provided is a latex composition suitable for use in a one-pack aqueous adhesive that has an excellent balance of excellent initial adhesive strength, adhesive layer texture, and storage stability, and that forms a flexible adhesive layer after drying. Also provided is a one-pack aqueous adhesive using the latex composition. This latex composition contains: 100 parts by mass (in terms of solid content) of a latex mixture that comprises (A) 50-90 mass%, in terms of solid content, of a chloroprene homopolymer latex that contains a chloroprene homopolymer obtained by emulsion-polymerizing chloroprene, and (B) 10-50 mass%, in terms of solid content, of a chloroprene copolymer latex containing a chloroprene copolymer obtained by emulsion-polymerizing chloroprene and 2,3-dichloro-1,3-butadiene; and (C) 3-7 parts by mass (in terms of solid content) of boric acid or at least one pH regulator selected from amino acids having an isoelectric point of 5.5-6.5.

Description

Latex composition and single liquid type water adhesive

The present invention relates to a latex composition having (A) a chloroprene homopolymer latex, (B) a chloroprene copolymer latex, and (C) a pH adjusting agent, and a single liquid type water system using the same Agent.

A usual adhesive is produced by using a vinyl acetate polymer, a chloroprene polymer, an acrylate polymer, a natural rubber, a urethane polymer or the like as a raw material. Among these, the chloroprene polymer is suitably used for a solvent-based contact adhesive or a graft adhesive, etc., since a high degree of adhesion can be obtained by a low-pressure connection to a wide range of adherends. Agent use. However, the solvent is followed by the risk of ignition in the working environment, or the special exhaust gas and recycling equipment cost taken to prevent it, and in addition to environmental pollution or human health considerations, volatile organic compounds (VOC) Limitations or solvent limitations become stricter year after year.

In order to cope with this limitation, the development of an aqueous adhesive using a chloroprene polymer latex has been actively carried out in order to eliminate the solvent, but the aqueous adhesive has a lower adhesion than the conventional solvent-based adhesive. .

Therefore, as a technique for improving the adhesion of an adhesive, particularly an initial adhesive force, the industry is conducting research on a two-component type of adhesive. For example, a two-liquid type adhesive is known, which is used for specific polymerization. A chloroprene latex is formulated with a specific amount of an acrylic latex or a combination of an SBR (Styrene Butadiene Rubber) emulsion and an anionic surfactant as a main component, and a polyvalent metal salt is used. As a hardener (Refer to Patent Documents 1 and 2).

The two-liquid type adhesive is not problematic when it is applied to the adherend by a brush or a roller. However, in the case of spray coating the above-mentioned adhesives, it is not possible to maintain the balance between the pot life of the adhesive and the initial adhesion, the unstable mixing ratio of the adhesive, the instability of the work, the clogging of the spray, and the like. .

Further, it is known that by making a chloroprene polymer latex contain a specific acrylic polymer latex and a specific surfactant, a balance suitable for initial adhesion and contact property, storage stability, and spray coating property can be obtained. A chloroprene polymer latex composition for use in a single-liquid type water-based adhesive agent having excellent properties (see Patent Document 3).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. SHO 56-59874

[Patent Document 2] Japanese Patent Laid-Open No. Hei 9-188860

[Patent Document 3] Japanese Patent Application No. 2009-271802

An object of the present invention is to provide a latex composition which is excellent in initial adhesion, excellent in texture of an adhesive layer, and storage stability, and which is suitable for a single-liquid aqueous adhesive which is soft after an adhesive layer is dried, and A single liquid aqueous binder is used.

In order to solve the above problems, the inventors of the present invention have conducted intensive studies and found that (A) a chloroprene homopolymer latex contains (B) a chloroprene copolymer latex and (C) a specific pH. The value adjuster can solve the above problems.

That is, the present invention is a latex composition comprising: 100 parts by mass of a latex mixture (in terms of solid content) having (A) a chloroprene containing a homopolymer of chloroprene obtained by emulsion polymerization of chloroprene The diene homopolymer latex is 50 to 90% by mass in terms of solid content, And (B) a chloroprene copolymer latex containing a chloroprene copolymer obtained by emulsion polymerization of chloroprene and 2,3-dichloro-1,3-butadiene in terms of solid content 10 to 50% by mass; and (C) 3 to 7 parts by mass of the pH adjuster (in terms of solid content), which is at least one selected from the group consisting of boric acid or an amino acid having an isoelectric point of 5.5 to 6.5.

The chloroprene homopolymer preferably has a gel content (toluene-insoluble matter) of 30% by mass or less, a toluene-soluble component having a number average molecular weight of 200,000 to 500,000, and a molecular weight distribution (Mw/Mn) of 2.0. ~4.0.

It is preferred that the content of the bonding unit derived from 2,3-dichloro-1,3-butadiene of the chloroprene copolymer is 5 to 50% by mass.

The hardness of the durometer (type A) specified in JIS K 6253-3, which is preferably a dried sheet obtained by drying the latex composition, is 30 to 70.

The chloroprene homopolymer and the chloroprene copolymer are preferably those in which the polymerization conversion ratio of the monomer is 65 mass% or more and less than 90 mass%.

The above latex composition can be used as a one-liquid aqueous binder.

The latex composition of the present invention maintains the faster crystallization speed of the chloroprene homopolymer latex without lowering the storage stability, the spray coating property, and improving the initial adhesion and contact property. It is useful as a composition for a single-liquid aqueous adhesive. In particular, since the adhesive layer after drying is relatively soft, it is suitable for a material such as a sofa, a bed, a chair, or the like, a toy such as a sofa, a bed, a chair, or the like, and a toy such as a doll, which are softened by the following two adherends. A foaming body (bubble) such as an automobile interior product and a one-liquid type aqueous adhesive agent to be used as a target, such as wood, leather, or foam.

Hereinafter, the present invention will be described in detail.

The latex composition of the present invention is characterized by containing (A) a chloroprene homopolymer latex containing a chloroprene homopolymer obtained by emulsion polymerization of chloroprene, and (B) containing a specific ratio. a chloroprene copolymer latex of a chloroprene copolymer obtained by emulsion polymerization of chloroprene with 2,3-dichloro-1,3-butadiene, and (C) selected from boric acid or isoelectric The point is at least one pH adjuster of the amino acid of 5.5 to 6.5.

(A) chloroprene homopolymer latex

The chloroprene homopolymer latex is blended in order to improve the contact property, heat-resistant adhesiveness, and initial adhesion of the one-component water-based adhesive using the latex composition. The chloroprene homopolymer latex is obtained by dispersing a chloroprene homopolymer in water in an emulsified state, and is obtained by emulsifying and polymerizing chloroprene using an emulsifier.

The chloroprene homopolymer contained in the chloroprene homopolymer latex preferably has a gel content (toluene-insoluble matter) of 30% by mass or less, and a toluene-soluble component has a number average molecular weight of 200,000 to 500,000. And the molecular weight distribution (Mw/Mn) is in the range of 2.0 to 4.0.

As the emulsifier used in the emulsion polymerization, rosin acid or an alkali metal salt thereof is used. When rosin acid or an alkali metal salt thereof is used as an emulsifier, the emulsion stability is liable to be lowered when a mechanical stimulus is applied to the latex composition. Therefore, excellent initial adhesion strength can be exhibited in the case of using a latex composition as an adhesive.

The emulsifier used in the emulsion polymerization is preferably rosin acid, and any of rosin acid, rosin acid, tall oil rosin acid, or disproportionated rosin acid obtained by disproportionation may be used. The amount of the rosin acid added is preferably 0.5 to 10 parts by mass, more preferably 2 to 6 parts by mass, per 100 parts by mass of all the monomers used. When it is less than 0.5 part by mass, the emulsification tends to be poor, so that problems such as deterioration of polymerization heat generation control, generation of aggregates, or poor appearance of the product are likely to occur. In the case of more than 10 parts by mass, the water resistance of the polymer is likely to be deteriorated due to the residual emulsifier, and the force is lowered, or the foaming during drying or the color tone of the product is deteriorated.

In the case of using rosin acid, after adding a pH adjuster, in order to make the chloroprene The olefin homopolymer latex is stabilized, and a sulfate-based or sulfonate-based anionic emulsifier or dispersant is preferably used in combination. In this case, the amount of the anionic emulsifier or dispersant other than rosin acid is preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 2 parts by mass, based on 100 parts by mass of all monomers used. .

As an anionic emulsifier or dispersant other than rosin acid, there are 8 to 20 carbon alkyl sulfonates, alkyl aryl sulfates, condensates of sodium naphthalene sulfonate and formaldehyde, and alkyl diphenyls. Sodium ether disulfonate.

The emulsifier may also be used in combination with a nonionic emulsifier or dispersant. By using a nonionic emulsifier in combination, the low temperature stability of the latex composition or the subsequent properties when the adhesive is formed can be improved. When a nonionic or cationic emulsifier or dispersant is used alone as an emulsifier or dispersant in emulsion polymerization, there is a possibility that it is not caused when a pH adjuster is added to form a water-based adhesive. Fully unstable, the performance of the initial adhesion becomes insufficient.

In the emulsion polymerization of chloroprene, a chain transfer agent is used in order to adjust the molecular weight or molecular weight distribution of the chloroprene polymer. As the chain transfer agent, there are long-chain alkyl mercaptans such as n-dodecyl mercaptan or tri-dodecyl mercaptan, diisopropyl xanthogen disulfide or diethyl xanthroate disulfide. Dialkyl xanthate disulfide such as an acid ester. From the viewpoint of easily controlling the molecular weight or the gel content, it is preferred to use a long-chain alkyl mercaptan. These chain transfer agents may be used in combination of two or more.

The polymerization conversion ratio of the raw material monomers in the chloroprene homopolymer latex is preferably 65 mass% or more and less than 90 mass%. In the case where the polymerization conversion ratio is less than 65%, there is a case where not only the solid content of the polymer latex is lowered, but also the drying step after the application of the adhesive is applied, or the uniformization of the subsequent layer is difficult, and There are problems such as odor caused by residual monomers or deterioration of adhesion and adhesion. In the case where the polymerization conversion ratio is 90% by mass or more, there is a case where the molecular weight distribution is enlarged due to an increase in branching in the polymer or an increase in molecular weight, and an important property is obtained in the present invention. The problem of deterioration in contact and water resistance. In the case of using a polymer having a conversion ratio of 90% by mass or more, it is preferably used as an auxiliary component of a polymer having a conversion ratio of less than 90% by mass. The polymerization conversion ratio (% by mass) was determined by [(sum of polymer mass/monomer mass) × 100].

The chloroprene homopolymer can be polymerized in the range of 5 to 45 ° C, and more preferably at a low temperature of 5 to 20 ° C. Regarding the chloroprene homopolymer, it is known that the trans-1,4-bond accounts for 85% or more, and its molecular structure is relatively regular. The chloroprene homopolymer has properties as a typical crystalline polymer due to the high degree of regularity of its molecular structure. By setting the polymerization temperature to a low temperature of 5 to 20 ° C, the ratio of the trans-1,4-bond in the polychloroprene molecule is further increased, so that the chloroprene homopolymerization having a higher crystallization rate can be obtained. The material achieves sufficient adhesion when it is made into a one-component aqueous binder.

As the initiator for the emulsion polymerization, a usual radical polymerization initiator can be used, and specifically, an organic or inorganic peroxide such as benzamidine peroxide, potassium persulfate or ammonium persulfate, or an azo diiso is used. An azo compound such as butyronitrile. An auxiliary catalyst such as sulfonium sulfonate or potassium sulfite or sodium sulfite may also be used as appropriate.

In the production of a chloroprene homopolymer, in order to obtain a polymer having a desired molecular weight and distribution, a polymerization terminator is added at a time when a specific polymerization rate is reached, and the reaction is stopped. As a polymerization terminator, there are phenothiazines. , p-tert-butyl catechol, hydroquinone, hydroquinone monomethyl ether, diethyl hydroxylamine.

The concentration of the solid content of the chloroprene homopolymer latex is not particularly limited and is usually from 40 to 65% by mass. The ratio of the chloroprene homopolymer latex to the latex mixture is 50 to 90% by mass in terms of solid content. When the amount is less than 50% by mass, the texture of the obtained adhesive layer is not soft, and does not exert a synergistic effect containing the following chloroprene copolymer latex. Further, in the case of more than 90% by mass, if the pH adjuster described below is not contained, the storage stability may be deteriorated or the initial adhesion force may be lowered.

Chloroprene homopolymer latexes are generally susceptible to degradation caused by oxygen. Yu Benfa In the present invention, it is preferred to use a stabilizer such as an antioxidant in a range that does not impair the effects of the invention.

The amount of the antioxidant to be added to the chloroprene homopolymer latex is preferably 0.1 to 3 parts by mass based on 100 parts by mass of the solid content of the chloroprene homopolymer latex. . By setting it as this range, the temporal stability of the softness of the obtained adhesive layer can be improved. When the antioxidant is insoluble in water or the emulsified state of the chloroprene homopolymer latex is unstable, it is preferably added in advance as an aqueous dispersion.

(B) chloroprene copolymer latex

The chloroprene copolymer latex is formulated in order to maintain the initial adhesion of the adhesive using the latex composition and adjust its storage stability to the texture (hardness) of the adhesive layer.

Preferably, the chloroprene copolymer latex is a copolymer of chloroprene and 2,3-dichloro-1,3-butadiene, and is derived from 2,3-dichloro-1,3-butadiene. The content of the bonding unit of the alkene is 5 to 50% by mass. The chloroprene copolymer contained in the chloroprene copolymer latex is preferably such that the polymerization conversion ratio of the monomer is 65 mass% or more and less than 95 mass%.

The chloroprene copolymer contained in the chloroprene copolymer latex is a copolymer of chloroprene and 2,3-dichloro-1,3-butadiene. The chloroprene copolymer can also be copolymerized with other monomers which can be copolymerized. As other monomers which can be copolymerized, there are 1-chloro-1,3-butadiene, butadiene, isoprene, styrene, acrylonitrile, acrylic acid and esters thereof, methacrylic acid and esters thereof. The class can be copolymerized within a range that does not inhibit the target properties of the present invention. The amount of copolymerization of 2,3-dichloro-1,3-butadiene and the other copolymerizable monomers is preferably 2,3-dichloro-1,3-butadiene, 1 -Chloro-1,3-butadiene, butadiene, isoprene, styrene, acrylonitrile, acrylates, methacrylates in the range of 0.01 to 20% by mass, acrylic acid, methacrylic acid It is set to a range of 0.01 to 7 mass%. The monomer constituting the copolymer may be used in combination of two or more kinds as needed. Further, two or more kinds of polymers may be mixed and used. Among them, the chloroprene constituting the chloroprene copolymer latex If the polymer is a homopolymer of chloroprene, a copolymer of chloroprene and 2,3-dichloro-1,3-butadiene, or a homopolymer of chloroprene and chloroprene with 2 A mixture of a copolymer of 3-dichloro-1,3-butadiene is preferred because the subsequent strength of the obtained single-liquid type water-based adhesive is increased. In the case where other copolymerizable monomers are used in combination with chloroprene, if the content of the bonding unit derived from other copolymerizable monomers in the copolymer exceeds 20% by mass, The force or contact is reduced, so it is not good.

When the chloroprene copolymer latex is obtained, it is sufficient to emulsify and polymerize the monomers. A stabilizer such as an emulsifier, a chain transfer agent, a polymerization initiator, a polymerization terminator or an antioxidant used in the emulsion polymerization can be used in an emulsion polymerization of a chloroprene homopolymer latex.

The polymerization conversion ratio of the raw material monomer in the chloroprene copolymer latex is preferably 65 mass% or more and less than 90 mass%. In the case where the polymerization conversion ratio is less than 65%, there is a case where not only the solid content of the polymer latex is lowered, but also the drying step after the application of the adhesive is applied, or the uniformization of the subsequent layer is difficult, and There are problems such as odor caused by residual monomers or deterioration of adhesion and adhesion. In the case where the polymerization conversion ratio is 90% by mass or more, there is a case where the molecular weight distribution is enlarged due to an increase in branching in the polymer or an increase in molecular weight, thereby producing contact properties which are important properties in the present invention, The problem of deterioration of water resistance. In the case of using a polymer having a conversion ratio of 90% by mass or more, it is preferably used as an auxiliary component of a polymer having a conversion ratio of less than 90% by mass. The polymerization conversion ratio (% by mass) was determined by [(sum of polymer mass/monomer mass) × 100].

The chloroprene copolymer can be polymerized in the range of 5 to 50 ° C, and more preferably at a high temperature of 30 to 50 ° C. By carrying out the emulsion polymerization in this range, the ratio of the trans-1,4-bond of the chloroprene copolymer can be intentionally lowered to further reduce the crystallization rate. Therefore, the adhesive layer of the obtained single-liquid type water-based adhesive becomes a soft texture. From the viewpoint of retarding the crystallization rate, in order to reduce the regularity of the molecular structure, it is preferably And use a monomer other than chloroprene.

The concentration of the solid content component of the chloroprene copolymer latex in the chloroprene copolymer latex is not particularly limited, and is usually 40 to 65% by mass. The ratio of the chloroprene copolymer latex to the latex mixture is 50 to 85% by mass in terms of solid content. When the amount is less than 50% by mass, the effect of softening the texture of the adhesive layer cannot be obtained. When it is more than 85% by mass, if the pH adjuster described below is not contained, the storage stability may be deteriorated or the initial adhesion force may be lowered.

(C) pH adjuster

The pH adjuster is formulated to increase the initial adhesion or storage stability of the latex composition. As the pH adjuster, a weak acid or a buffer solution may be used, and at least one compound selected from the group consisting of boric acid or an amino acid having an isoelectric point of 5.5 to 6.5 may be used.

As the amino acid having an isoelectric point of 5.5 to 6.5, specifically, there are glycine (5.97), alanine (6.00), threonine (6.16), and valine (6.30). Glycine as a kind of amino acid is preferably used in terms of cost or subsequent performance, ease of handling, and the like.

The amount of the pH adjusting agent to be added is not particularly limited, and an amount which can adjust the pH of the adhesive composition to a range of 7 to 10 should be used. It is desirable to adjust the pH range to 8 to 10.

When boric acid is used as the pH adjuster, it is preferable to use it as an aqueous solution of 5% concentration, since handling becomes easy. Further, when glycine acid is used as the pH adjuster, it is preferably used in an amount of 1 to 20 parts by mass, more preferably 2 parts by mass based on 100 parts by mass (solid content) of the chloroprene homopolymer latex. ~16 parts by mass, and more preferably 3 to 13 parts by mass. If the amount of glycine added is too small, sufficient adhesion is not exhibited and storage stability is also lowered. If the amount added is too large, it becomes disadvantageous in terms of cost, or agglomerates are generated at the time of addition, or storage stability is lowered.

In the latex composition of the present invention, in addition to the components (A), (B), and (C), (D) a plasticizer 1 to 20 represented by the following formula (1) may be added as needed. Parts by mass.

(wherein R ₁ and R ₃ represent an aliphatic alkyl group having 1 to 3 carbon atoms or a hydrogen atom, and R ₁ and R ₃ may have the same structure or different structures. R ₂ represents a carbon number of 5~ 20 aliphatic alkyl groups)

By adding the plasticizer described above, the texture of the obtained adhesive layer can be made soft, or the adhesion can be maintained even if the drying time (O.T. (Open time)) becomes long.

The amount of the plasticizer to be added represented by the formula (1) is preferably from 1 to 20 parts by mass, more preferably from 2 to 15 parts by mass, per 100 parts by mass of the latex composition (solid content). Further, it is preferably in the range of 5 to 10 parts by mass. If the amount of the plasticizer added is small, there is a case where the adhesion force is lowered when the drying time is prolonged. Further, when the amount of the plasticizer added is large, there is a case where the initial adhesion force is lowered or the cost is also disadvantageous.

Further, it is preferred that the (E) hindered phenol-based antioxidant is contained in the latex composition of the present invention. The hindered phenol-based antioxidant has an effect of improving the discoloration or hygienic property of the paste overflow portion (glueline) when the latex composition is used as an adhesive. Hindered phenolic antioxidants are 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tributyl) Butyl phenol), 4,4'-butylene bis(3-methyl-6-tert-butylphenol), butylated reaction product of p-cresol and dicyclopentadiene. The amount of the hindered phenol-based antioxidant added is preferably from 0.1 to 3% by mass, and more preferably from 0.5 to 2% by mass, based on 100 parts by mass of the solid content of the latex composition. When the amount of the antioxidant added is less than 0.1% by mass, the antioxidant effect is insufficient. On the other hand, if it exceeds 3% by mass, the adhesion and the adhesion may be deteriorated.

In the latex composition of the present invention, a filler, an adhesion-imparting agent, a pigment, a colorant, a wetting agent, an antifoaming agent, a thickener, or the like can be suitably used as the above, within the range which does not inhibit the effects of the present invention. Additives. In addition, 10% by mass (in terms of solid content) of the entire composition may be used as an upper limit, and other resin emulsions (latex) may be additionally formulated. Specific examples thereof include resin resins such as (modified) vinyl acetate, vinyl acetate-acrylic acid mixed, acrylic-styrene mixed, and urethane.

The preparation method of the latex composition is not particularly limited, but if the pH is less than 9, since the colloidal destabilization of the latex mixture is preferred, it is preferred to first mix (A) a chloroprene homopolymer latex with ( B) A method of adding a (C) pH adjuster to a chloroprene copolymer latex. Further, it is preferable that each auxiliary component is added as a dispersion of an aqueous system. The latex composition obtained in the above manner can be directly used as a one-liquid aqueous binder.

Suitable adherends for the single-liquid aqueous binder include a foam (bubble) containing a material such as polyurethane, ethylene-vinyl acetate copolymer, polyethylene, or the like, or water such as wood, cloth, or fabric. Sexuality is the body.

The polymer latex composition produced under the conditions described above has a soft adhesive layer, and can be suitably used as a single sheet having excellent initial adhesion and contact property, water resistance, spray coating property, and storage stability. A liquid aqueous binder.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples. These examples do not limit the invention. In addition, in the following examples, the parts and % are based on mass unless otherwise specified.

[Experimental Example 1]

Manufacture of chloroprene homopolymer latex A-1

100 parts of pure water, 5 parts of sodium rosinate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.3 parts of sodium hydrogen sulfite were added under a nitrogen gas flow using a reactor having an internal volume of 3 liters. After dissolving, 100 parts of a chloroprene monomer and 0.06 parts of n-dodecyl mercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 10 ° C under a nitrogen atmosphere, and phenothiazine was added at a final polymerization rate of 65%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Further, the water was evaporated under reduced pressure to concentrate, and the solid content concentration was adjusted to 55% by mass to obtain a chloroprene homopolymer latex A-1. The gel content of the chloroprene homopolymer latex A-1 was 0%, the Mn of the toluene soluble component was 300,000, and the molecular weight distribution (Mw/Mn) was 2.5.

[Experimental Example 2]

Manufacture of chloroprene homopolymer latex A-2

100 parts of pure water, 5 parts of sodium rosinate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.3 parts of sodium hydrogen sulfite were added under a nitrogen gas flow using a reactor having an internal volume of 3 liters. After dissolving, 100 parts of a chloroprene monomer and 0.06 parts of n-dodecyl mercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 10 ° C under a nitrogen atmosphere, and phenothiazine was added at a time when the final polymerization rate reached 70%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Further, the water was evaporated under reduced pressure to concentrate, and the solid content concentration was adjusted to 55% by mass to obtain a chloroprene homopolymer latex A-2. The gel content of the chloroprene homopolymer latex A-2 was 5%, the Mn of the toluene soluble component was 300,000, and the molecular weight distribution (Mw/Mn) was 2.5.

[Experimental Example 3]

Manufacture of chloroprene homopolymer latex A-3

100 parts of pure water, 5 parts of sodium rosinate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.3 parts of sodium hydrogen sulfite were added under a nitrogen gas flow using a reactor having an internal volume of 3 liters. After dissolving, 100 parts of a chloroprene monomer and 0.06 parts of n-dodecyl mercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 10 ° C under a nitrogen atmosphere, and phenothiazine was added at a final polymerization rate of 85%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Further, the water was evaporated under reduced pressure to concentrate, and the solid content concentration was adjusted to 55% by mass to obtain a chloroprene homopolymer latex A-3. The gel content of the chloroprene homopolymer latex A-3 was 30%, the Mn of the toluene soluble component was 300,000, and the molecular weight distribution (Mw/Mn) was 2.5.

[Experimental Example 4]

Manufacture of chloroprene homopolymer latex A-4

100 parts of pure water, 5 parts of sodium rosinate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.3 parts of sodium hydrogen sulfite were added under a nitrogen gas flow using a reactor having an internal volume of 3 liters. After dissolving, 100 parts of a chloroprene monomer and 0.06 parts of n-dodecyl mercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 10 ° C under a nitrogen atmosphere, and phenothiazine was added at a time when the final polymerization rate reached 90%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Further, the water was evaporated under reduced pressure and concentrated, and the solid content concentration was adjusted to 55% by mass to obtain a chloroprene homopolymer latex A-4. The gel content of the chloroprene homopolymer latex A-4 was 40%, the Mn of the toluene soluble component was 300,000, and the molecular weight distribution (Mw/Mn) was 2.5.

[Experimental Example 5]

Manufacture of chloroprene homopolymer latex A-5

100 parts of pure water, 5 parts of sodium rosinate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.3 parts of sodium hydrogen sulfite were added under a nitrogen gas flow using a reactor having an internal volume of 3 liters. After dissolving, 100 parts of a chloroprene monomer and 0.14 parts of n-dodecyl mercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 10 ° C under a nitrogen atmosphere, and phenothiazine was added at a final polymerization rate of 80%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Further, the water was evaporated under reduced pressure to concentrate, and the solid content concentration was adjusted to 55% by mass to obtain a chloroprene homopolymer latex A-5. The gel content of the chloroprene homopolymer latex A-5 was 15%, the Mn of the toluene soluble component was 100,000, and the molecular weight distribution (Mw/Mn) was 2.5.

[Experimental Example 6]

Manufacture of chloroprene homopolymer latex A-6

100 parts of pure water, 5 parts of sodium rosinate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.3 parts of sodium hydrogen sulfite were added under a nitrogen gas flow using a reactor having an internal volume of 3 liters. After dissolving, 100 parts of a chloroprene monomer and 0.10 part of n-dodecyl mercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 10 ° C under a nitrogen atmosphere, and phenothiazine was added at a final polymerization rate of 80%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Furthermore, the water was evaporated under reduced pressure and concentrated, and the solid content concentration was adjusted to 55% by mass to obtain a chloroprene homopolymer latex A-6. The gel content of the chloroprene homopolymer latex A-6 was 15%, the Mn of the toluene soluble component was 250,000, and the molecular weight distribution (Mw/Mn) was 2.5.

[Experimental Example 7]

Manufacture of chloroprene homopolymer latex A-7

100 parts of pure water, 5 parts of sodium rosinate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.3 parts of sodium hydrogen sulfite were added under a nitrogen gas flow using a reactor having an internal volume of 3 liters. After dissolving, 100 parts of a chloroprene monomer and 0.10 part of n-dodecyl mercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 5 ° C under a nitrogen atmosphere, and phenothiazine was added at a time when the final polymerization rate reached 80%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Further, the water was evaporated under reduced pressure to concentrate, and the solid content concentration was adjusted to 55% by mass to obtain a chloroprene homopolymer latex A-7. The gel content of the chloroprene homopolymer latex A-7 was 15%, the Mn of the toluene soluble component was 300,000, and the molecular weight distribution (Mw/Mn) was 2.0.

[Experimental Example 8]

Manufacture of chloroprene homopolymer latex A-8

100 parts of pure water, 5 parts of sodium rosinate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.3 parts of sodium hydrogen sulfite were added under a nitrogen gas flow using a reactor having an internal volume of 3 liters. After dissolving, 100 parts of a chloroprene monomer and 0.08 parts of n-dodecyl mercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 10 ° C under a nitrogen atmosphere, and phenothiazine was added at a final polymerization rate of 80%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Further, the water was evaporated under reduced pressure to concentrate, and the solid content concentration was adjusted to 55% by mass to obtain a chloroprene homopolymer latex A-8. The gel content of the chloroprene homopolymer latex A-8 was 15%, the Mn of the toluene soluble component was 300,000, and the molecular weight distribution (Mw/Mn) was 4.0.

[Experimental Example 9]

Manufacture of chloroprene homopolymer latex A-9

100 parts of pure water, 5 parts of sodium alkyl diphenyl ether disulfonate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and a nitrogen gas stream were used in a reactor having an internal volume of 3 liters. 0.3 parts of sodium hydrogen sulfite was dissolved, and 100 parts of chloroprene monomer and 0.10 part of n-dodecyl mercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 10 ° C under a nitrogen atmosphere, and phenothiazine was added at a final polymerization rate of 80%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Furthermore, the water was evaporated under reduced pressure and concentrated, and the solid content concentration was adjusted to 55% by mass to obtain a chloroprene homopolymer latex A-9. The gel content of the chloroprene homopolymer latex A-9 was 15%, the Mn of the toluene soluble component was 250,000, and the molecular weight distribution (Mw/Mn) was 2.5.

[Experimental Example 10]

Manufacture of chloroprene homopolymer latex A-10

100 parts of pure water, 5 parts of sodium alkylbenzenesulfonate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and hydrogen sulfite were added under a nitrogen gas flow using a reactor having an internal volume of 3 liters. After 0.3 parts of sodium, after dissolving, 100 parts of chloroprene monomer and 0.10 part of n-dodecyl mercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 10 ° C under a nitrogen atmosphere, and phenothiazine was added at a final polymerization rate of 80%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Further, the water was evaporated under reduced pressure to concentrate, and the solid content concentration was adjusted to 55% by mass to obtain a chloroprene homopolymer latex A-10. The gel content of the chloroprene homopolymer latex A-10 was 15%, the Mn of the toluene soluble component was 250,000, and the molecular weight distribution (Mw/Mn) was 2.5.

[Experimental Example 11]

Manufacture of chloroprene homopolymer latex A-11

Using a reactor with an internal volume of 3 liters, 100 parts of pure water, 5 parts of sodium polyoxyethylene sulfate, 0.5 parts of potassium hydroxide, 0.3 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and sodium hydrogen sulfite were added under a nitrogen gas stream. After 0.3 part of the solution, 100 parts of a chloroprene monomer and 0.10 part of n-dodecyl mercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 10 ° C under a nitrogen atmosphere, and phenothiazine was added at a final polymerization rate of 80%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Further, the water was evaporated under reduced pressure to concentrate, and the solid content concentration was adjusted to 55% by mass to obtain a chloroprene homopolymer latex A-11. The gel content of the chloroprene homopolymer latex A-11 was 15%, the Mn of the toluene soluble component was 250,000, and the molecular weight distribution (Mw/Mn) was 2.5.

The gel content of the chloroprene homopolymer latexes A-1 to A-11, the Mn (number average molecular weight) of the toluene soluble component, and the molecular weight distribution (Mw/Mn) were determined by the following methods. The value.

[gel content]

After each sample was freeze-dried, the sample was accurately weighed and set to X. This was dissolved in toluene (prepared to 0.6%), and after using a centrifugal separator, the gel component was separated using a 200 mesh metal mesh. After the separated gel component was air-dried, it was dried in an atmosphere of 110 ° C for 1 hour, and the mass was accurately weighed and set to Y.

The gel content rate was calculated by the following formula (1).

[Mn and molecular weight distribution (Mw/Mn) of toluene soluble components]

GPC (Gel Permeation Chromatography) was measured under the following conditions, and the molecular weight in terms of polystyrene was measured, and the weight average molecular weight (Mw), the number average molecular weight (Mn), and the molecular weight distribution (Mw/Mn) were evaluated. ). The measurement was carried out by preparing a toluene-soluble component (sol) separated by a gel component content measurement to prepare a 0.1% tetrahydrofuran (THF) solution.

Measuring device: HLC-8120GPC manufactured by Tosoh

Column for analysis: TSK-GEL GMH _HR- H (5 μm) × 3 manufactured by Tosoh, size 7.8 mm φ × 300 mm

Protection column: Guard Column TSK-Guard Column TSK-Guard Column H _HR -H (5μm), size 6mmφ×40mm, column temperature: 40°C

Solvent: THF grade, flow: 1ml/min

[Experimental Example 12]

Manufacture of chloroprene copolymer latex B-1

Using a reactor with an internal volume of 3 liters, 100 parts of pure water, 4 parts of sodium rosinate, 1.5 parts of potassium hydroxide, 0.5 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.5 parts of sodium hydrogen sulfite were added under a nitrogen gas stream. After dissolving, 99 parts of chloroprene and 1 part of 2,3-dichloro-1,3-butadiene and 0.04 parts of n-dodecylmercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 40 ° C under a nitrogen atmosphere, and phenothiazine was added at a time when the final polymerization rate reached 90%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Furthermore, the water was evaporated under reduced pressure and concentrated, and the solid content concentration was adjusted to 60% by mass to obtain a chloroprene copolymer latex B-1.

[Experimental Example 13]

Manufacture of chloroprene copolymer latex B-2

Using a reactor with an internal volume of 3 liters, 100 parts of pure water, 4 parts of sodium rosinate, 1.5 parts of potassium hydroxide, 0.5 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.5 parts of sodium hydrogen sulfite were added under a nitrogen gas stream. After the dissolution, 95 parts of chloroprene and 5 parts by mass of 2,3-dichloro-1,3-butadiene and 0.04 parts of n-dodecylmercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 40 ° C under a nitrogen atmosphere, and phenothiazine was added at a time when the final polymerization rate reached 90%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Further, the water was evaporated under reduced pressure and concentrated, and the solid content concentration was adjusted to 60% by mass to obtain a chloroprene copolymer latex B-2.

[Experimental Example 14]

Manufacture of chloroprene copolymer latex B-3

Using a reactor with an internal volume of 3 liters, 100 parts of pure water, 4 parts of sodium rosinate, 1.5 parts of potassium hydroxide, 0.5 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.5 parts of sodium hydrogen sulfite were added under a nitrogen gas stream. After the dissolution, 90 parts of chloroprene and 10 parts by mass of 2,3-dichloro-1,3-butadiene and 0.04 parts of n-dodecylmercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 40 ° C under a nitrogen atmosphere, and phenothiazine was added at a time when the final polymerization rate reached 90%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Furthermore, the water was evaporated under reduced pressure and concentrated, and the concentration of the solid content was adjusted to 60% by mass to obtain a chloroprene copolymer latex B-3.

[Experimental Example 15]

Manufacture of chloroprene copolymer latex B-4

Using a reactor with an internal volume of 3 liters, 100 parts of pure water, 4 parts of sodium rosinate, 1.5 parts of potassium hydroxide, 0.5 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.5 parts of sodium hydrogen sulfite were added under a nitrogen gas stream. After the dissolution, 50 parts of chloroprene and 50 parts by mass of 2,3-dichloro-1,3-butadiene and 0.04 parts of n-dodecylmercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 40 ° C under a nitrogen atmosphere, and phenothiazine was added at a time when the final polymerization rate reached 90%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Furthermore, the water was evaporated under reduced pressure and concentrated, and the solid content concentration was adjusted to 60% by mass to obtain a chloroprene copolymer latex B-4.

[Experimental Example 16]

Manufacture of chloroprene copolymer latex B-5

Using a reactor with an internal volume of 3 liters, 100 parts of pure water, 4 parts of sodium rosinate, 1.5 parts of potassium hydroxide, 0.5 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and 0.5 parts of sodium hydrogen sulfite were added under a nitrogen gas stream. After the dissolution, 40 parts of chloroprene and 60 parts by mass of 2,3-dichloro-1,3-butadiene and 0.04 parts of n-dodecylmercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 40 ° C under a nitrogen atmosphere, and phenothiazine was added at a time when the final polymerization rate reached 90%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Further, the water was evaporated under reduced pressure to concentrate, and the solid content concentration was adjusted to 60% by mass to obtain a chloroprene copolymer latex B-5.

[Experimental Example 17]

Manufacture of chloroprene copolymer latex B-6

100 parts of pure water, 4 parts of sodium alkyl diphenyl ether disulfonate, 1.5 parts of potassium hydroxide, 0.5 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and a nitrogen gas stream were used in a reactor having an internal volume of 3 liters. After dissolving 0.5 parts of sodium hydrogen sulfite, 90 parts of chloroprene and 10 parts by mass of 2,3-dichloro-1,3-butadiene and 0.04 parts of n-dodecylmercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 40 ° C under a nitrogen atmosphere, and phenothiazine was added at a time when the final polymerization rate reached 90%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Furthermore, the water was evaporated under reduced pressure and concentrated, and the concentration of the solid content was adjusted to 60% by mass to obtain a chloroprene copolymer latex B-6.

[Experimental Example 18]

Manufacture of chloroprene copolymer latex B-7

100 parts of pure water, 4 parts of sodium alkylbenzenesulfonate, 1.5 parts of potassium hydroxide, 0.5 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and hydrogen sulfite were added under a nitrogen gas flow using a reactor having an internal volume of 3 liters. After 0.5 part of sodium was dissolved, 90 parts of chloroprene and 10 parts by mass of 2,3-dichloro-1,3-butadiene and 0.04 parts of n-dodecylmercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 40 ° C under a nitrogen atmosphere, and phenothiazine was added at a time when the final polymerization rate reached 90%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Furthermore, the water was evaporated under reduced pressure and concentrated, and the concentration of the solid content was adjusted to 60% by mass to obtain a chloroprene copolymer latex B-7.

[Experimental Example 19]

Manufacture of chloroprene copolymer latex B-8

Using a reactor with an internal volume of 3 liters, 100 parts of pure water, 4 parts of sodium polyoxyethylene sulfate, 1.5 parts of potassium hydroxide, 0.5 parts of sodium salt of formaldehyde naphthalenesulfonic acid condensate, and sodium hydrogen sulfite were added under a nitrogen gas stream. After 0.5 part of the solution, 90 parts of chloroprene and 10 parts by mass of 2,3-dichloro-1,3-butadiene and 0.04 parts of n-dodecylmercaptan were added while stirring. 0.1 parts by weight of potassium persulfate was used as a starter, and polymerization was carried out at 40 ° C under a nitrogen atmosphere, and phenothiazine was added at a time when the final polymerization rate reached 90%. The emulsion was stopped and the polymerization was stopped. After the unreacted monomer was removed under reduced pressure, 0.3 part of a polyoxyalkylene alkyl ether of a low-temperature stabilizer was added to 100 parts of the solid content with stirring. Furthermore, the water was evaporated under reduced pressure and concentrated, and the concentration of the solid content was adjusted to 60% by mass to obtain a chloroprene copolymer latex B-8.

The emulsifier or dispersant used in the production of the chloroprene homopolymer latex and the chloroprene copolymer latex of the examples and the comparative examples was as follows.

Sodium rosinate: 3R-70N manufactured by Arakawa Chemical Industry Co., Ltd.

Sodium alkyl diphenyl ether disulfonate: Pelex SSH manufactured by Kao Co., Ltd.

Sodium alkylbenzene sulfonate: Neopelex G-15 manufactured by Kao Co., Ltd.

Polyoxyethylene sulfate: Latemul E-118B manufactured by Kao Co., Ltd.

Naphthalenesulfonic acid formaldehyde condensate sodium salt: Demol N manufactured by Kao Co., Ltd.

[pH adjuster]

pH modifier C-1 formulated in the aqueous binder composition of the examples and comparative examples The ~C-7 system uses the following.

C-1. Glycine (isoelectric point: 5.97)

C-2. Alanine (isoelectric point: 6.00)

C-3. sulphonic acid (isoelectric point: 6.16)

C-4.5% boric acid aqueous solution (prepared by dissolving 5 g of boric acid (powder) in 95 g of pure water)

C-5. Proline (isoelectric point: 6.30)

C-6. Amphetamine (isoelectric point: 5.48)

C-7. Histamine (isoelectric point: 7.59)

[Other reagents]

The other reagents to be formulated in the aqueous adhesive compositions of the examples and the comparative examples were as follows.

Dibutyl sebacate: plasticizer manufactured by Tiangang Chemical Industry Co., Ltd.

Nipol LX820A: Acrylic Latex manufactured by Zeon Co., Ltd., Japan

[Preparation of single-liquid aqueous binder]

100 parts by mass (converted solid content) of chloroprene homopolymer latex A-1~A-11 and chloroprene copolymer latex B-1 to B-8, as shown in Table 1 to Table 5 The single-liquid aqueous adhesives of Examples 1 to 21 and Comparative Examples 1 to 34 were prepared by adding the pH adjusters C-1 to C-7.

The initial adhesion force of the obtained single-liquid aqueous adhesive, the texture of the adhesive layer, the durometer hardness of the dried sheet, and the storage stability were measured by the following methods, and the measurement was performed. The results are shown in Tables 1 to 5.

[initial adhesion]

The density of 30kg / m ³ of the polyurethane foam body (thickness of a width of 20mm × 50mm × 50mm length) was subsequently used as a body in the atmosphere at 23 ℃ became 70g / m ² of the embodiment-based one-pack spray coating Aqueous adhesive. After being applied for 10 seconds or 1 minute in an atmosphere of 23 ° C after application, the bonding faces of the two polyurethane foam bodies were superposed on each other in a state in which the single-liquid aqueous adhesive was not dried, and the thickness was 40 mm. Up to 10mm and hold for 5 seconds. Immediately thereafter, a tensile test was performed by a tensile tester (automatic stereographer manufactured by Shimadzu Corporation: tensile speed: 200 mm/min) in a direction perpendicular to the adjoining surface, and the initial adhesion (N/cm ² ) measurement was measured.

The case where the initial adhesion force was 3.0 N/cm ² or more was evaluated as acceptable.

[The texture of the adhesive layer]

In the same manner as the evaluation method of the initial adhesion force described above, a polyurethane foam having a density of 30 kg/m ³ (thickness: 20 mm × length: 50 mm × width: 50 mm) was used as a adherend, and it was 70 g/at 23 ° C atmosphere. A single-liquid aqueous binder is spray-coated in the form of m ² . After the coating was allowed to stand in an atmosphere of 23 ° C for 1 minute, the bonding faces of the two polyurethane foam bodies were overlapped with each other in a state in which the single-liquid aqueous adhesive was not dried, and the thickness was 40 mm to 10 mm and kept. 5 seconds. Thereafter, after standing at 23 ° C for 24 hours, the texture of the adhesive layer was evaluated by the touch of the fingers. The texture of the polyurethane foam and the adhesive layer was evaluated as ○, the texture of the adhesive was slightly harder than the polyurethane foam, and the adhesive layer was harder than the polyamine. The carbamate body was evaluated as ×.

[Durgency hardness of dry sheet (type A)]

An adhesive prepared to have a thickness of about 3.5 mm was poured into a petri dish made of Teflon (registered trademark), and dried at 23 ° C for 5 days to evaporate the volatile matter to obtain a dried sheet. Further, using a vacuum dryer (manufactured by Yamato Scientific, DP-41), the dried sheet was dried at 23 ° C for 2 days, and then the hardness of the durometer specified in JIS K 6253-3 was measured (A). type).

The case where the hardness of the durometer (type A) was in the range of 30 to 70 was evaluated as acceptable.

[Storage Stability]

After the heat treatment at 250 ° C for 7 days of 250 g of the one-liquid aqueous adhesive was observed, the presence or absence of the viscosity increase and the state were observed. The viscosity of the one-liquid aqueous adhesive was not evaluated as ○, and the solidified or coagulable product was evaluated as ×.

As shown in the evaluation results of Tables 1 to 5, the initial adhesion of the single-liquid aqueous binder of Examples 1 to 21 of the composition range within the scope of the present invention, the texture of the adhesive layer, and the dried sheet were The hardness of the durometer (type A) and storage stability were good.

On the other hand, not using an alkali metal salt or a salt of rosin emulsion polymerization, the emulsifier used in Comparative Example 2 to 4 other than the above-described 13 to 24 and the initial bonding strength of 3.0N / cm ² or less and are not well .

The texture of the adhesive layers of Comparative Examples 1 to 5, 9, 13, 17, and 21, which contained the specifications of the present invention but had a blending ratio outside the predetermined range, was not good.

Further, the initial adhesion strength of Comparative Examples 25 and 27 in which the blending amount of the pH adjusting agent of the present invention was outside the predetermined range, and the storage stability of the adhesives of Comparative Examples 26 and 28 were not good. Further, when a pH adjusting agent other than the predetermined type was used as in Comparative Examples 29 and 30, aggregates or solidification occurred during the preparation of the adhesive, and the subsequent physical properties could not be evaluated.

As shown in Comparative Examples 5 to 12, when the content of the monomer unit of 2,3-dichloro-1,3-butadiene in the chloroprene copolymer latex is outside the predetermined range, the adhesive layer The hardness of the texture and hardness tester is not good.

In the case where dibutyl sebacate (plasticizer) was blended into the chloroprene homopolymer latex as in Comparative Example 31, although good initial adhesion strength was obtained, the texture of the adhesive layer was not good. .

As shown in Comparative Examples 32 to 34, in the case where an acrylic latex was prepared as an adhesive in the composition shown in Table 5 in a chloroprene homopolymer latex, the texture of the adhesive layer was good, but initially followed. The strength is not good, or the storage stability of the adhesive is poor.

Claims (6)

A latex composition comprising: 100 parts by mass of a latex mixture (in terms of solid content) having (A) homopolymer of chloroprene containing a homopolymer of chloroprene obtained by emulsion polymerization of chloroprene The latex is 50 to 90% by mass in terms of solid content, and (B) contains a chloroprene copolymer obtained by emulsion polymerization of chloroprene and 2,3-dichloro-1,3-butadiene. The chloroprene copolymer latex is 10 to 50% by mass in terms of solid content; and (C) 3 to 7 parts by mass of the pH adjuster (in terms of solid content), which is selected from boric acid or isoelectric point. At least one of the amino acids of 5.5 to 6.5. The latex composition of claim 1, wherein the chloroprene homopolymer gel content (toluene-insoluble component) is 30% by mass or less, and the toluene-soluble component has a number average molecular weight of 200,000 to 500,000, and the molecular weight is The distribution (Mw/Mn) is 2.0 to 4.0. The latex composition of claim 1 or 2, wherein the chloroprene copolymer has a bonding unit derived from 2,3-dichloro-1,3-butadiene in an amount of 5 to 50% by mass. The latex composition according to any one of claims 1 to 3, wherein the durometer hardness (type A) specified in JIS K 6253-3 of the dried sheet obtained by drying the latex composition is 30 to 70. The latex composition according to any one of claims 1 to 4, wherein a polymerization conversion ratio of the chloroprene homopolymer and the chloroprene copolymer monomer is 65 mass% or more and less than 95 mass% By. A one-component aqueous adhesive comprising the latex composition of any one of claims 1 to 5.