JP3415659B2 - Polychloroprene latex composition - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polychloroprene latex composition suitable as an aqueous contact adhesive.

[0002]

2. Description of the Related Art Conventionally, solvent-based adhesives have been the mainstream of polychloroprene-based adhesives, but in recent years solvent-based adhesives have been disliked due to toxicity, flammability, environmental problems, etc. during manufacture and use. There is a tendency that the demand for non-solvent is increasing.

The polychloroprene latex adhesive has high adhesive properties and, at the same time, does not require an organic solvent in the production of the adhesive, does not have the above-mentioned problems, and is expected as a substitute for the conventional solvent-based adhesive.

Polychloroprene latex adhesive has a high initial adhesive strength (hereinafter referred to as "contact") immediately after bonding by applying the adhesive to both adherend surfaces to be joined and almost drying the adhesive layer. Sex ").

For these reasons, the polychloroprene latex adhesive has been put into practical use as a contact type adhesive, but the contact property is not always sufficient, and further improvement has been desired.

As an improvement method, for example, a resin emulsion is used in combination, but the adhesive property is remarkably changed depending on the kind of the resin emulsion, and the ordinary commercial resin emulsion is improved by making both heat resistance and contact property compatible. It is difficult to do so.

[0007] Further, the asymmetric asymmetric rosin ester gives good adhesion to polychloroprene latex, but hitherto satisfies all of the contact property, heat resistance and storage stability when mixed with latex. There was nothing concrete to do.

On the other hand, JP-A-50-22047 discloses a latex obtained by polymerizing chloroprene and an unsaturated carboxylic acid in the presence of a polymeric protective colloid. However, no reference is made to the formulation of resin emulsions.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polychloroprene latex composition having excellent adhesive strength, contact property, etc., and excellent storage stability.

[0010]

Means for Solving the Problems In the process of studying the addition of various resin emulsions to polychloroprene latex, the present inventors have prepared a resin emulsion prepared by using a resin component of a specific type and an emulsifier of a specific type as polychloroprene. It has been confirmed that the addition to the latex dramatically improves the contact property and heat resistance of the latex and at the same time improves the storage stability.

That is, the present invention provides a resin emulsion 5 in which (1) 100 parts by weight of polychloroprene latex and (2) asymmetric asymmetric rosin glycerin ester having an acid value of 5 or less are dispersed in water with an anionic surfactant. It is a polychloroprene latex composition characterized by containing -100 parts by weight. In the present invention, the above polychloroprene latex protects 100 parts by weight of a mixture of chloroprene alone or another monomer copolymerizable with chloroprene and 0.5 to 10 parts by weight of an ethylenically unsaturated carboxylic acid. The above polychloroprene latex composition obtained by emulsion polymerization in the presence of 1 to 10 parts by weight of a water-soluble polymer having a colloidal action, wherein the anionic surfactant comprises a sulfonate and a sulfate. A polychloroprene latex composition comprising one or more anionic surfactants selected from the group. Further, the present invention is a contact adhesive containing the above polychloroprene latex composition as a main component.

The present invention will be described in detail below. Anionic surfactants used in the resin emulsion of the present invention include carboxylates, sulfonates and sulfates, among which sulfonates and sulfates are preferred.
The following may be mentioned as anionic surfactants of sulfonate and sulfate.

Examples of the anionic surfactant of sulfonate include alkylallyl sulfonates such as sodium dodecylbenzene sulfonate, sodium isopropyl naphthalene sulfonate, condensed sodium naphthalene sulfonate, and β-naphthalene sulfonate formalin condensate. Polycondensate of alkyl allyl sulfonate such as sodium salt, sodium dioctyl sulfosuccinate, alkyl sulfo succinate such as sodium dihexyl sulfo succinate, sodium octylbenzene polyoxyethylene sulfonate, sodium nonylbenzene polyoxyethylene sulfonate Alkylaryl polyoxyalkylene sulfonates and the like.

As the sulfate anionic surfactant,
Alkyl sulfate ester salts such as sodium lauryl sulfate, triethanolamine lauryl sulfate, sodium polyoxyethylene oleyl ether sulfate, polyoxyethylene alkyl ether sulfate salts such as polyoxyethylene sodium lauryl sulfate, sodium polyoxyethylene nonylphenyl ether sulfate, poly Examples include polyoxyethylene alkylphenyl ether sulfates such as sodium oxyethylene oleyl phenyl ether sulfate.

The resin emulsion in the present invention can be prepared by a method of dispersing a resin in water using the above-mentioned anionic surfactant.

Other monomers copolymerizable with chloroprene in the present invention include 1,3-butadiene, isoprene,
2,3-dichlorobutadiene, styrene, etc. can be mentioned. Further, a plurality of monomers consisting of these groups of monomers can be used in combination. The amount of these monomers used is usually equimolar or less with respect to chloroprene.

Examples of the ethylenically unsaturated carboxylic acid in the present invention include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, citraconic acid and glutaconic acid. These ethylenically unsaturated carboxylic acids can be used alone or in combination of two or more.

The amount of the ethylenically unsaturated carboxylic acid added is preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of chloroprene, and is 1 to 5 parts by weight, although it varies depending on the type and molecular weight of the unsaturated carboxylic acid. It is particularly suitable. If the amount of the unsaturated carboxylic acid added is less than 0.5 part by weight, it is difficult to obtain sufficient adhesive strength and heat resistance. On the other hand, if it exceeds 10 parts by weight, the stability is deteriorated during storage or compounding of the latex. To be

Examples of the water-soluble polymer having a protective colloid effect in the present invention include various water-soluble polymers having a protective colloid effect, that is, an effect of stabilizing hydrophobic fine particles in water.

Specific examples of the water-soluble polymer having a protective colloid action include polyvinyl alcohol and its copolymer (for example, copolymer with acrylamide), polyvinylpyrrolidone and its copolymer (for example, with vinyl acetate). Examples thereof include copolymers), cellulose derivatives (hydroxymethyl cellulose, hydroxyethyl cellulose, etc.), and those obtained by chemically modifying these polymers.

The amount of this water-soluble polymer having a protective colloid action is 1 to 10 with respect to 100 parts by weight of chloroprene.
Weight parts are preferred. If the amount added is less than 1 part by weight, agglomerates frequently occur during the polymerization reaction, and if it exceeds 10 parts by weight, the viscosity during polymerization increases and the stability decreases.

In the present invention, various chain transfer agents having a chain transfer action can be made to coexist during the polymerization reaction of chloroprene.

The polychloroprene latex composition of the present invention can be prepared by mixing 5 to 100 parts by weight of the above resin emulsion with 100 parts by weight of the polychloroprene latex.

Further, the polychloroprene latex composition of the present invention may optionally contain a commonly used latex compounding agent such as an antioxidant, a film-forming agent, a metal oxide, a vulcanizing agent and a thickener. be able to.

The polychloroprene latex composition of the present invention can be blended using any of the various mixing equipment commonly used for latex blending.

Adhesives using the polychloroprene latex composition of the present invention produced as described above include paper, wood, cloth, leather, leather, rubber, plastic, plastic foam, pottery, glass, ceramics, metal and the like. It can be used for bonding the same kind or different kinds.

[0027]

The present invention will be described in more detail with reference to Examples.

Example 1 Preparation of polychloroprene latex: 40 parts by weight of polyvinyl alcohol (Dencapovar B-05: average polymerization degree 550, saponification degree 88) in a 3 liter four-necked flask.
%), And 1050 parts by weight of pure water, and heat (60
℃) and dissolved. When this aqueous solution was cooled to near room temperature, 1000 parts by weight of chloroprene and 30 parts of methacrylic acid were added.
Parts by weight and 3.0 parts by weight of octyl mercaptan were added.

While keeping this at 40 ° C., stirring (200
rpm), and an initiator (potassium persulfate / anthraquinone-β-sodium sulfonate) was added under a nitrogen stream to proceed with polymerization to obtain an emulsion polymer. A 20% diethanolamine aqueous solution was added thereto to adjust the pH to 7, and then a 50% water-soluble fatty acid alkanolamide [1: 2 mol type fatty acid alkanolamide / Modicol N (manufactured by Diamond Shamrock Chemical Co.)] aqueous solution was prepared. 10 parts by weight was added (referred to as "polychloroprene latex A").

Preparation of resin emulsion: 100 parts by weight of glycerin ester of asymmetrical rosin having an acid value of 4 was added to 50 parts by weight of toluene and dissolved by heating. Next, 10 parts by weight of this solution, sodium anionylbenzene polyoxyethylene sulfonate, which is an anionic surfactant, was added to 12 parts of water.
It was added to an aqueous solution dissolved in 0 part by weight, and mixed and stirred with a homogenizer (3,000 rpm, 3 min) to emulsify and mix. This emulsified mixture was high-pressure emulsified with a high-pressure emulsifier at a pressure of 300 kg / cm ² , and toluene was separated using an evaporator (vacuum distillation apparatus) (50 ℃, -100 mmHg depressurization, about 5 hours) to give a resin emulsion (solid content). 50 wt%).

The above polychloroprene latex 100
35 parts by weight of resin emulsion, zinc oxide finely dispersed in an aqueous ammonia solution of casein to a concentration of 50 wt% and an antioxidant (2,6-di-tert-butyl-4-).
2 parts by weight of methylphenol) (each part by weight is calculated as solid content), and a thickener (sodium polyacrylate) is added to make the composition have a viscosity of 5,000 cps (
A Brookfield viscometer, No. 3 rotor, 6 rpm) was added to obtain a polychloroprene latex composition.

Next, this composition was applied with canvas and veneer as adherends. The amount of coating and the area of attachment at that time are 350 g / m ² , 25 mm x 80 m for canvas.
In m and veneer, it was 150 g / m ² , 25 mm x 25 mm. The adherends were attached to each other after the coated surfaces were dried. Immediately after bonding veneers to each other
Sensory evaluation of (adhesive strength, peeling state) for "contactability"
And On the other hand, after sticking canvases or veneers together and drying them at room temperature for 7 days (at room temperature, humidity 50%), measure the adhesive strength to determine the "peel strength" (between canvases) or "shear strength" (between veneers). did. Also, the "glue margin" of this joined body of canvases (dried for 7 days)
Attach a weight of 1 kg to one end of the, and fix the other side to the ceiling of a gear oven kept at 70 ℃,
The time required for the weight to fall under the atmosphere was measured and designated as "high temperature peeling".

Example 2 The same procedure as in Example 1 was repeated except that 250 parts by weight of 1000 parts by weight of chloroprene was replaced with 2,3-dichlorobutadiene (hereinafter referred to as "polychloroprene latex B"). A polychloroprene latex composition was prepared to evaluate the adhesive properties.

Example 3 A polychloroprene latex composition was prepared in the same manner as in Example 1 except that sodium dodecylbenzene sulfonate was used as the anionic surfactant, and the adhesive properties were evaluated.

Comparative Example 1 A polychloroprene latex composition was prepared in the same manner as in Example 1 except that nonionic polyoxyethylene lauryl ether (HLB = 12.1) was used as the surfactant.
The adhesive properties were evaluated.

Comparative Example 2 A polychloroprene latex composition was prepared in the same manner as in Example 1 except that nonionic polyoxyethylene cetyl ether (HLB = 14.2) was used as the surfactant, and the adhesive properties were evaluated. .

Comparative Example 3 A polychloroprene latex composition was prepared in the same manner as in Example 1 except that sodium salt of styrene-maleic acid copolymer was used instead of sodium nonylbenzene polyoxyethylene sulfonate, and the adhesive property was obtained. Was evaluated.

Comparative Example 4 Same as Example 1 except that asymmetrical rosin acid glycerol ester having an acid value of 6 was used as the asymmetrical rosin acid ester and sodium dodecylbenzene sulfonate was used as the anionic surfactant. Then, a polychloroprene latex composition was prepared and the adhesive properties were evaluated.

Comparative Example 5 As Example 1 except that asymmetrical rosin acid pentaerythritol ester having an acid value of 18 was used as the asymmetrical rosin acid ester and sodium dodecylbenzenesulfonate was used as the anionic surfactant. Similarly, a polychloroprene latex composition was prepared and the adhesive properties were evaluated.

Comparative Example 6 A polychloroprene latex composition was prepared in the same manner as in Example 1 except that the asymmetric asymmetric rosin acid ester was changed to terpene phenol and sodium dodecylbenzenesulfonate was used as the anionic surfactant. Then, the adhesive property was evaluated.

Table 1 shows the results of Examples 1 to 3 and Comparative Examples 1 to 6 described above.

[0042]

[Table 1]

(Note) 1) Asymmetric asymmetric rosin acid glycerin ester (acid value 4) /
Nonylbenzene sodium polyoxyethylene sulfonate 2) Asymmetrical rosin acid glycerin ester (acid value 4) /
Sodium dodecylbenzene sulfonate 3) Asymmetrical rosin acid glycerin ester (acid value 4) /
Polyoxyethylene lauryl ether (HLB = 12.1) 4) Asymmetric asymmetric rosin acid glycerin ester (acid value 4) /
Polyoxyethylene cetyl ether (HLB = 14.2) 5) Asymmetric asymmetric rosin acid glycerin ester (acid value 4) /
Styrene-maleic acid copolymer sodium 6) Asymmetric asymmetric rosin acid glycerin ester (acid value 6) /
Sodium dodecylbenzene sulfonate 7) Asymmetric asymmetric rosin acid pentaerythritol ester (acid value 18) / sodium dodecylbenzene sulfonate 8) Terpene phenol / sodium dodecyl benzene sulfonate 9) ZnO dispersion: ZnO in ammonia / casein aqueous solution ball mill Was used to disperse. 10) Viscosity: Brookfield type viscometer, 6 rpm, 25 ° C. 11) Contact property (adhesive state, 5 grade evaluation from failure mode) 5: High initial adhesive strength (adhesive interface failure or partial material failure) 4: Initial adhesion Medium strength (adhesive interface failure) 3: Low initial adhesive strength (cohesive failure or partial adhesive interface failure) 2: Almost no initial adhesion can be obtained (partial adhesion / cohesive failure) 1: No stickiness, and bonding is not possible 12) Adhesive strength: Tensile speed = 100mm / min [Autograph AG-5000S (Shimadzu)] 13) High temperature peeling: 1kg weight is hung on one end of the 2.5cm width bonded canvas, and the weight is dropped at 70 ℃. Measure time.

[0044]

As described above, the polychloroprene latex composition of the present invention is excellent in contact property and adhesiveness, especially in high temperature, and has good storage stability. It can be used as a substitute for

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Claims (6)

(57) [Claims] (1) Polychloroprene latex 10
A polychloroprene latex composition comprising 0 parts by weight and (2) 5 to 100 parts by weight of a resin emulsion in which an asymmetric asymmetric rosin glycerin ester having an acid value of 5 or less is dispersed in water with an anionic surfactant. object. 2. The protective colloid of 100 parts by weight of the polychloroprene latex in claim 1 mixed with chloroprene alone or with another monomer copolymerizable with chloroprene and 0.5 to 10 parts by weight of ethylenically unsaturated carboxylic acid. A polychloroprene latex composition which is emulsion-polymerized in the presence of 1 to 10 parts by weight of a water-soluble polymer having an action. 3. A polychloroprene latex composition, wherein the anionic surfactant in claim 1 is one or more anionic surfactants selected from the group consisting of sulfonates and sulfates. object. 4. A contact adhesive containing the polychloroprene latex composition according to claim 1 or 2 as a main component. 5. Obtained by emulsion polymerization of 100 parts by weight of (1) chloroprene alone or a mixture with another monomer copolymerizable with chloroprene and 0.5 to 10 parts by weight of an ethylenically unsaturated carboxylic acid. Polychloroprene Latex 1
100 parts by weight and (2) 5-100 parts by weight of a resin emulsion in which an asymmetric asymmetric rosin acid glycerin ester having an acid value of 5 or less is dispersed in an anionic surfactant in water, the polychloroprene latex. Composition. 6. A polychloroprene latex composition, wherein the water-soluble polymer in claim 2 is polyvinyl alcohol.