JP2002155168A - Polychloroprene latex composition and aqueous adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polychloroprene latex composition excellent in color fastness to light and an aqueous adhesive prepared by using the same. SOLUTION: This latex composition contains a chloroprene polymer, zinc oxide, and a hydrotalcite compound. Preferably, the hydrotalcite compound is hydrotalcite. The aqueous adhesive is prepared by using the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a raw material for a coating agent such as an adhesive or a coating film waterproofing agent, a binder for a nonwoven fabric, a latex-impregnated paper, a dipped product, a foam rubber, etc.
The present invention relates to a latex composition containing polychloroprene latex.

[0002]

2. Description of the Related Art A chloroprene polymer has a property of causing a dehydrochlorination reaction under the influence of light or heat. For this reason, products using the chloroprene-based latex composition often contain zinc oxide as an acid acceptor for the purpose of improving storage stability. In the case of a chloroprene-based latex in which a carboxyl group is introduced into a polymer chain, it is known that the adhesive performance and the like can be improved by blending zinc oxide as a crosslinking agent. As described above, conventionally, zinc oxide is known to be a very effective substance in maintaining high quality and performance of a product using the chloroprene-based latex composition. However, when a dried film of a chloroprene-based latex composition containing zinc oxide is exposed to sunlight for a long period of time, the color may change to black-brown, and a new formulation that can suppress this is required. .

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel formulation for improving the photo-discoloration resistance of a polychloroprene latex composition containing zinc oxide.

[0004]

Means for Solving the Problems As a result of repeated studies to achieve the above object, the present inventors have found that by blending a hydrotalcite compound with zinc oxide, the discoloration of black brown caused by zinc oxide can be reduced. It has been found that a polychloroprene latex composition which can be suppressed and has excellent light discoloration resistance can be obtained, and the present invention has been completed.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The chloroprene polymer contained in the polychloroprene latex composition of the present invention is 2
-A homopolymer of chloro-1,3-butadiene (hereinafter referred to as chloroprene) or a copolymer obtained by copolymerizing chloroprene with one or more monomers copolymerizable with chloroprene. Examples of monomers copolymerizable with chloroprene include, for example, 2,3-dichloro-1,3-
Butadiene, 1-chloro-1,3-butadiene, butadiene, isoprene, styrene, acrylonitrile, acrylic acid and its esters, methacrylic acid and its esters, and the like, and if necessary, two or more kinds may be used. .

The chloroprene polymer according to the present invention comprises:
Preferably, it is blended in the form of a latex obtained by emulsion polymerization of the above monomers in water. The emulsifier and / or dispersant used for emulsifying the latex is not particularly limited, and various anionic, nonionic and cationic types usually used for chloroprene latex can be used. Examples of the anionic emulsifier include a carboxylic acid type and a sulfate type. For example, alkali metal salts of rosin acid, alkyl sulfonates having 8 to 20 carbon atoms, alkyl aryl sulfates, sodium naphthalene sulfonate and formaldehyde are used. And condensates. Specific examples of the nonionic type include polyvinyl alcohol or a copolymer thereof (for example, a copolymer with acrylamide), polyvinyl ether or a copolymer thereof (for example, a copolymer with maleic acid), polyvinyl pyrrolidone or a copolymer thereof. Examples thereof include polymers (for example, copolymers with vinyl acetate), those obtained by chemically modifying these (co) polymers, and cellulose derivatives (hydroxyethyl cellulose). Specific examples of the cationic type include an aliphatic amine salt and an aliphatic quaternary ammonium salt, and examples thereof include octadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, and dilauryldimethylammonium chloride.

[0007] The amount of the emulsifier and / or dispersant added to the latex in the present invention is 1
The amount is preferably 0.5 to 20 parts by mass with respect to 00 parts by mass.
If the amount is less than 0.5 parts by mass, the emulsifying power is not sufficient and
If the amount exceeds 0 parts by mass, the adhesive strength of the adhesive will be reduced.

[0008] The method of polymerizing the chloroprene polymer in the present invention is not particularly limited, and the polymerization temperature, polymerization catalyst, chain transfer agent, polymerization terminator, final polymerization rate, demonomerization, concentration conditions, and the like are appropriately adjusted. By selection and control, it is possible to adjust the solid content concentration, the molecular weight of the toluene-soluble portion, the toluene-insoluble content (gel content), and the like.

[0009] The polymerization temperature of the chloroprene polymer in the present invention is not particularly limited, but the polymerization temperature is preferably 10 to 50 ° C in order to smoothly carry out the polymerization reaction. The polymerization catalyst is a sulfated salt such as potassium persulfate, an organic peroxide such as tert-butyl hydroperoxide, or the like, and is not particularly limited.

The type of chain transfer agent used for the polymerization is not particularly limited, and those usually used for emulsion polymerization of chloroprene can be used. For example, long-chain alkyl such as n-dodecyl mercaptan or tert-dodecyl mercaptan can be used. Known chain transfer agents such as mercaptans, dialkylxanthogen disulfides such as diisopropylxanthogen disulfide and diethylxanthogen disulfide, and iodoform can be used.

The polymerization terminator (polymerization inhibitor) is not particularly limited. For example, 2,6-tert-butyl-4
-Methylphenol, phenothiazine, hydroxyamine and the like can be used.

The final polymerization rate of the chloroprene polymer is not particularly limited, and can be arbitrarily adjusted.
Unreacted monomers are removed by a demonomer operation, but the method is not particularly limited. The latex containing the chloroprene-based polymer of the present invention can be adjusted to a required solid concentration by concentrating or diluting by adding water or the like. Examples of the method for concentration include concentration under reduced pressure, but are not particularly limited. However, in consideration of the drying speed when the polychloroprene-based latex composition is used as a binder for an aqueous adhesive or a nonwoven fabric, and the storage stability of the composition, the solid content concentration of the latex is preferably 40 to 65% by mass.

The zinc oxide of the present invention has a particular particle shape.
Not limited to, spherical, needle-like, scale-like (plate-like), spindle-like,
It may be polyhedral, amorphous, or the like.
Also includes what are called ultrafine particles. In addition, particle size and specific surface
Properties such as product and hue are not limited. Zinc oxide of the present invention
Means scanning electron microscope or transmission electron microscope or original
The maximum primary particle diameter observed by a child force microscope is 0.0
01 μm or more and less than 50 μm, or JIS
The gas adsorption method (BET method) specified in R1626
Therefore, the measured specific surface area, that is, per unit mass
Sum of surface area of all primary particles contained in powder (m^Two/
g) with its average surface area calculated based on g)
The diameter of the sphere (average surface area diameter) is 0.001 μm or more.
Preferably it is less than 5 μm. Fill this range
If zinc oxide is added, sedimentation or coagulation in the latex composition will occur.
Latex composition with less storage and good storage stability
You can get things. The primary particles here are powder
・ The particles that constitute agglomerates can break bonds between molecules.
It is the smallest unit of particle that exists.

The method for producing zinc oxide is not particularly limited, and those produced by various known synthetic methods such as a French method (indirect method), an American method (direct method), and a wet method can be used. The French method (indirect method) is a method in which zinc metal is heated to 1000 ° C., vaporized, and oxidized by hot air to produce zinc oxide powder. The American method (direct method) is a method in which a reducing agent is added to a natural ore containing zinc to directly vaporize the zinc and produce zinc oxide powder with hot air. The wet method is a method of synthesizing zinc oxide by an aqueous phase reaction. For example, an aqueous solution of soda ash is added to an aqueous solution of zinc chloride to precipitate basic zinc carbonate, which is washed, dried, and dried at about 600 ° C. Obtained by heating. Further, composite particles of zinc oxide particles and silica or the like as described below may be used. In JP-A-2000-72432 (applicant: Dokai Chemical Industry Co., Ltd.), zinc oxide or the like is formed on the outer surface or on the inner surface of the silica aggregate particles formed by overlapping the flaky silica primary particles. A method for supporting a metal fine particle to produce a composite is described. JP-A-8-104515 (Applicant: Asahi Glass Co., Ltd.)
Describes a method for producing a zinc oxide-containing spherical silica by gelling a dispersion obtained by dispersing zinc oxide in an aqueous alkali silicate solution with carbon dioxide gas.

The amount of zinc oxide is not limited, but is preferably from 0.01 part by mass to less than 50 parts by mass based on 100 parts by mass of the polychloroprene-based latex as solids. If the amount is 50 parts by mass or more, the viscosity of the polychloroprene-based latex composition is too high, and there is a concern that processing operations such as coating, dipping, and impregnation become difficult. A more preferred compounding amount is 0.05 parts by mass or more and less than 10 parts by mass. In this range, the latex composition having good storage stability can be uniformly dispersed in the latex composition with zinc oxide particles. Obtainable.

The hydrotalcite compound in the present invention is a compound represented by the following general formula (I). In the formula, M ²⁺ represents a divalent metal atom such as Mg and Ni. M ³⁺ represents a trivalent metal atom such as Al, Fe, Cr, and Mn. A ^n- is an n-valent anion such as OH
^{-, Cl-, NO 3-, CO} 3 2-, indicating from 1 to 4 monovalent anions such as SO ₄ ^2-. x is 0 <x, y is 2x ≦ y, and m is 0 <
Indicates an integer satisfying m. _{^{[M 2+ yx M 3+ x (}} OH) 2y] [A n- x / n · mH 2 O] (I) that _{^{is, [M 2+ yx M 3+ x}} (OH) 2y] Basic layer, [ A ^n- _{x / n}
[MH ₂ O] is an intermediate layer and is a compound having a multilayered crystal structure in which a positively charged basic layer and a negatively charged intermediate layer are alternately stacked.

The hydrotalcite compound of the present invention comprises
Dehydration of water of crystallization, whether natural or synthetic
It may be what you did. In addition, synthesis method, place of origin, particles
Properties such as shape, particle size, particle surface area, water content, bulk specific gravity, etc.
The shape is not limited. Specific examples of natural products include hydro
Talcite (hydrotalcite, chemical formula: [M
g₆Al_Two(OH)₁₆] [CO_Three・ 4H_TwoO]), pillow light
(Pyrourite, chemical formula: [Mg₆Fe_Two(OH)
₁₆] [CO_Three・ 4.5H_TwoO]), stichite (Stich)
title, chemical formula: [Mg₆Cr_Two(OH)₁₆] [CO_Three・ 4H_Two
O]), Desautelsite
e, chemical formula: [Mg₆Mn_Two(OH)₁₆] [CO_Three・ 4H
_TwoO]), takovite, chemical formula: [N
i₆Al_Two(OH)₁₆] [CO_Three・ 4H_TwoO]), lebesite
(Reevesite, chemical formula: [Ni ₆Fe_Two(OH)₁₆]
[CO_Three・ 4H_TwoO]).

The synthesized product is described, for example, in JP-B-46-2280.
Gazette, Japanese Patent Publication No. 50-30039, Japanese Patent Publication No. 51-
It can be synthesized by a known method as exemplified in JP-A-29129. As a specific example,
In the case of synthetic hydrotalcite, magnesium chloride (M
gCl ₂ ) and aluminum chloride (AlCl ₃ ), an aqueous solution of sodium hydroxide (NaOH) and an aqueous solution of sodium carbonate (Na ₂ CO ₃ ) were added to the mixed aqueous solution with stirring. Hydrotalcite is obtained. As each metal raw material, seawater can be used in addition to the aqueous solution of soluble salts. Hydrotalcite in which the divalent metal atom is Mg and the trivalent metal atom is Al is inexpensive and most suitable.

The blending amount of the hydrotalcite compound can be arbitrarily determined according to the required performance. However, in order to uniformly and stably disperse the chloroprene polymer in the polychloroprene latex composition, the chloroprene polymer is converted to a solid content. It is preferable that the amount is 0.01 part by mass or more and less than 100 parts by mass with respect to 100 parts by mass. When the amount is less than 0.01 part by mass, the effect of improving the light discoloration resistance is hardly obtained. If the amount is 100 parts by mass or more, the viscosity of the polychloroprene-based latex composition is too high, and there is a concern that processing operations such as coating, dipping, and impregnation become difficult. A more preferred compounding amount is 0.05 parts by mass or more and less than 10 parts by mass. In this range, the hydrotalcite compound can be uniformly dispersed in the latex composition, and the storage stability of the latex composition is good. You can get things.

The method of compounding the hydrotalcite compound is not particularly limited, but it is preferable to prepare the aqueous dispersion using a dispersant or emulsifier and then mix it, since the compound can be uniformly and stably mixed. . Of course, it is also possible to mix in a powder state.

The polychloroprene latex composition of the present invention contains a chloroprene polymer, zinc oxide and a hydrotalcite compound as essential components. Depending on the purpose of use, a compounding agent usually added to the latex, for example, Thickeners, fillers, UV absorbers, antioxidants, tackifier resins, pH adjusters, metal oxides other than zinc oxide, vulcanizing agents (crosslinking agents), vulcanization accelerators, curing agents, gelling agents , A surfactant, a foaming agent, a defoaming agent, an antibacterial agent, a fungicide, a fragrance, a film-forming aid, and the like can be optionally used. Inorganic powders such as zinc oxide, hydrotalcite, and fillers have large specific gravities, so that when the viscosity of the compound is low, it tends to settle at the bottom of the container.
This sedimentation can be prevented by increasing the viscosity of the latex composition with a thickener. Specific thickeners include:
Sodium polyacrylate, water-soluble polyurethane, associative polyurethane emulsion, alkali-swellable acrylic emulsion, carboxymethyl cellulose (CM
C), methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), polyvinyl alcohol, bentonite, synthetic smectite and the like. In addition, in order to reduce product cost, it is effective to add an inexpensive filler. Specific examples of the filler include pulverized natural minerals, synthetic silica, calcium carbonate, aluminum hydroxide, titanium oxide, Examples include barium sulfate and talc.

Examples of the ultraviolet absorber include benzotriazole compounds, benzophenone compounds, triazine compounds, hindered amine compounds, organic nickel compounds, and ultrafine metal oxides. Examples of the anti-aging agent include amine compounds, monophenol compounds, bisphenol compounds, polyphenol compounds, and the like.Amine compounds may cause coloring and odor problems. And / or bisphenol compounds are preferred.

The polychloroprene-based latex set of the present invention
Various products such as tackifier resins usually used for adhesives
An aqueous system with excellent initial adhesive strength by mixing the compounding agents
An adhesive can be obtained. Used in this water-based adhesive
Specific examples of the tackifying resin include rosin resin and polymerized resin.
Gin resin, α-pinene resin, β-pinene resin, terpene
Phenol resin, C _FiveDistillate petroleum resin, C₉Distilled petroleum tree
Fat, C_Five/ C₉Distillate petroleum resin, DCPD petroleum resin,
Alkylphenol resin, xylene resin, coumarone resin,
Coumarone indene resin and the like. Enough initial contact
In order to obtain adhesion, a softening point
Fats are preferred.

When the tackifier resin is added, the method of addition is not particularly limited, but it is preferable to add the resin as an aqueous emulsion in order to uniformly disperse the resin in the adhesive. Further, in the method for producing an aqueous emulsion of a tackifying resin, a solution dissolved in an organic solvent such as toluene is emulsified / dispersed in water using an emulsifier.
There are a method of removing the organic solvent by heating while reducing the pressure, a method of pulverizing the organic solvent into fine particles and emulsification / dispersion, and the former capable of producing a fine particle emulsion is preferable.

The amount of the tackifier resin (in terms of solid content)
With respect to 100 parts by mass of the chloroprene polymer as a solid content,
20 to 100 parts by mass are preferred. If the amount is less than 20 parts by mass, the initial adhesive strength is insufficient. If the amount exceeds 100 parts by mass, formation of the adhesive film is hindered, and poor adhesion is likely to occur.

As the pH adjuster, in addition to amino acids such as glycine, alcohol amines such as diethanolamine, and weak acids such as acetic acid are preferably used. Metal oxides other than zinc oxide include rutile-type titanium oxide, anatase-type titanium oxide, amorphous titanium oxide, magnesium oxide,
Cerium oxide, ferrous oxide, ferric oxide, zirconium oxide, aluminum oxide, antimony trioxide, antimony pentoxide, lead trioxide, lead dioxide, bismuth trioxide, tungsten oxide and the like can be blended.

The water-based adhesive referred to in the present invention simply contains the above-mentioned polychloroprene-based latex, and may be used when joining two adherends of the same or different types. The material and shape of the compounding agent and the adherend are not limited. The water-based adhesive of the present invention can be used for bonding footwear, transportation vehicle interiors, civil engineering construction, sporting goods, etc., and non-foamed rubber, non-foamed plastic, FR
P, foamed rubber, foamed plastic, knitted fabric, woven fabric, nonwoven fabric, paper, paper tube, pottery, ceramic, concrete, gypsum board, wood, glass, metal, etc.

There is no particular limitation on the method of treating the polychloroprene-based latex composition of the present invention and the residual liquid of the aqueous adhesive and the waste liquid generated from the washing liquid using the same, and they are generally used in the field of emulsion and latex. , Drying method,
The treatment can be performed by a method such as an aggregation method. The drying method is a treatment method in which the waste liquid is heated to evaporate water and generate a solid. The coagulation method means that the solid content is 10
% While adding a flocculant to the waste liquid adjusted to below
This is a method in which stirring is stopped when aggregates are formed, and the aggregates and the supernatant are separated by filtration. The coagulant used includes an inorganic coagulant and a polymer coagulant. Examples of the inorganic coagulant include ferric polysulfate, ferric chloride, aluminum sulfate (commonly referred to as a sulfate band), and polyaluminum chloride. (Commonly known as PAC), titanyl sulfate (TiOSO ₄ ) and the like. When ferric polysulfate or ferric chloride is used, the pH of the waste liquid must be adjusted to 4 to 8, and when aluminum sulfate or polyaluminum chloride is used, the pH of the waste liquid is adjusted to 6 to 8. There is a need to. Examples of the polymer-based flocculant include polyacrylamide-based and sodium polyacrylate-based. It is also possible to use an inorganic coagulant and an organic coagulant in combination.

[0029]

EXAMPLES Hereinafter, the effects of the present invention will be described with reference to examples and comparative examples, but these examples do not limit the present invention. In the following description,% and parts are expressed on a mass basis unless otherwise specified.

EXPERIMENTAL EXAMPLE 1 In a nitrogen atmosphere, 3.5 parts by mass of polyvinyl alcohol were dissolved at 60 ° C. in a nitrogen atmosphere using a 3 liter reactor. After cooling the aqueous polyvinyl alcohol solution to near room temperature, 99 parts by mass of chloroprene monomer and 1 part of methacrylic acid were added thereto.
Parts by mass and 0.4 parts by mass of octyl mercaptan were added.
While maintaining this at 45 ° C., polymerization was carried out using sodium sulfite and potassium persulfate as initiators to obtain a polychloroprene latex. Next, a 20% by mass aqueous solution of diethanolamine was added to the polychloroprene-based latex to adjust the pH to 7, and concentrated by heating under reduced pressure to adjust the solid content to 55% by mass. When the solid content of this polychloroprene-based latex and the gel content of the copolymer were measured by the following methods, the solid content was 55% by mass and the gel content was 29% by mass.

[Solid Content Concentration]
And An aluminum dish containing 2 ml of the latex sample was weighed and designated as B. Place the aluminum dish containing the latex sample in 110
After drying in an atmosphere at a temperature of 2 ° C. for 2 hours, it was weighed to obtain C. The solid concentration (%) was determined by the following equation. Solid concentration = {(CA) / (BA)} × 100

[Measurement of Gel Content (Toluene-Insoluble Content)] A latex sample was freeze-dried and weighed to obtain A. After dissolving with toluene (adjusted to 0.6%) at 23 ° C. for 20 hours, the gel was separated using a centrifuge and further using a 200 mesh wire mesh. The gel was air-dried and then dried under an atmosphere of 110 ° C. for 1 hour. The gel content (%) was calculated according to the following equation. Gel content = (BA) × 100

Example 1 40 parts by mass of synthetic hydrotalcite Kyoward 500 (manufactured by Kyowa Chemical Industry Co., Ltd.), 4 parts by mass of polycarboxylic acid dispersant Poise 530 (manufactured by Kao Corporation), pure water Was mixed and stirred and dispersed in a ball mill for 4 days.
An 8.6% aqueous dispersion was prepared. This aqueous dispersion is designated as aqueous dispersion A. For 100 parts by mass (solid content) of the polychloroprene-based latex prepared in Experimental Example 1, 2 parts by mass (solid content conversion) of Nanotek ZnO (manufactured by C-I Kasei Co., Ltd.) of a 30% aqueous dispersion of zinc oxide. Primal RM-8W, a water-soluble polyurethane thickener
(Rohm and Haas Japan K.K.) was mixed with 0.06 parts by mass (in terms of solids) and 2 parts by mass (in terms of solids) of the aqueous dispersion A to obtain a polychloroprene-based latex composition A. The polychloroprene-based latex composition A was evaluated by the following method.

[Method for Evaluating Light Discoloration Resistance] Polychloroprene-based latex composition A was applied to blotting paper Shim-1 (manufactured by KOKUYO Co., Ltd.) at a rate of 200 g / m ² with a brush.
After drying for an hour, the sample was irradiated with a xenon weather meter (manufactured by Suga Test Instruments Co., Ltd.) for 12 hours. During the irradiation, the temperature of the black panel was controlled at 63 ° C., and the humidity was 50 ° C.
% Rh. The color tone is a multiple light source spectrophotometer M
multi Spectro Color Meter
The lightness (L *) and the hunter whiteness (W (Lab)) were measured by (Suga Test Instruments Co., Ltd.).

Example 2 An aqueous dispersion A was prepared in the same manner as in Example 1. AZ-SW of a 50% aqueous dispersion of zinc oxide with respect to 100 parts by mass (solid content) of the polychloroprene-based latex prepared in Experimental Example 1
3 parts by mass (manufactured by Osaki Kogyo Co., Ltd.) (in terms of solid content), Primal RM-8W, a water-soluble polyurethane-based thickener
(Rohm and Haas Japan K.K.) was mixed with 0.06 parts by mass (in terms of solids), and 2 parts by mass (in terms of solids) of the aqueous dispersion A to obtain a polychloroprene-based latex composition B. The light discoloration resistance of the polychloroprene latex composition B was evaluated in the same manner as in Example 1.

Example 3 An aqueous dispersion A was prepared in the same manner as in Example 1. For 100 parts by mass (in terms of solid content) of the polychloroprene-based latex prepared in Experimental Example 1, 2 parts of zinc oxide powder zinc powder (manufactured by Sakai Chemical Industry Co., Ltd.) were 4 parts by mass in a powder state, and water-soluble. 0.06 parts by mass (in terms of solid content) of Primal RM-8W (manufactured by Rohm and Haas Japan KK), a polyurethane thickener, and 2 parts by mass (in terms of solid content) of aqueous dispersion A
The mixture was mixed to obtain a polychloroprene-based latex composition C. The light discoloration resistance of the polychloroprene-based latex composition C was evaluated in the same manner as in Example 1.

Example 4 An aqueous dispersion A was prepared in the same manner as in Example 1. 100% by mass (solid content) of the polychloroprene-based latex prepared in Experimental Example 1 was added to Nanote in a 30% aqueous dispersion of zinc oxide.
k ZnO (manufactured by CI Kasei Co., Ltd.) in an amount of 2 parts by mass (in terms of solid content) and a water-soluble polyurethane-based thickener Prima
l RM-8W (manufactured by Rohm and Haas Japan K.K.) was 0.06 parts by mass (in terms of solid content), and a terpene phenol-based tackifying resin emulsion, Tamanol E-
100 (manufactured by Arakawa Chemical Industry Co., Ltd.) was mixed with 45 parts by mass (in terms of solids) and 2 parts by mass (in terms of solids) of the aqueous dispersion A to obtain a polychloroprene latex composition D. The photochromic resistance of the polychloroprene-based latex composition D was evaluated in the same manner as in Example 1.

Example 5 An aqueous dispersion A was prepared in the same manner as in Example 1. AZ-SW of a 50% aqueous dispersion of zinc oxide with respect to 100 parts by mass (solid content) of the polychloroprene-based latex prepared in Experimental Example 1
3 parts by mass (manufactured by Osaki Kogyo Co., Ltd.) (in terms of solid content), Primal RM-8W, a water-soluble polyurethane-based thickener
(Manufactured by Rohm and Haas Japan KK) was 0.06 parts by mass (in terms of solid content), and tanol phenol-based tackifying resin emulsion Tamanol E-100 (manufactured by Arakawa Chemical Industries, Ltd.) was 45 parts by mass (solids). 2 parts by weight (in terms of solid content) of the aqueous dispersion A were mixed to obtain a polychloroprene-based latex composition E. The light discoloration resistance of the polychloroprene latex composition E was evaluated in the same manner as in Example 1.

Comparative Example 1 100 parts by mass (in terms of solid content) of the polychloroprene-based latex prepared in Experimental Example 1
Against a 30% aqueous dispersion of zinc oxide Nanotek
2 parts by mass (solid content) of ZnO (manufactured by C-I Kasei Co., Ltd.), Primal, a water-soluble polyurethane-based thickener
RM-8W (manufactured by Rohm and Haas Japan KK) was mixed with 0.06 parts by mass (in terms of solid content) to obtain a polychloroprene-based latex composition F. The light discoloration resistance of the polychloroprene-based latex composition F was evaluated in the same manner as in Example 1.

Comparative Example 2 100 parts by mass (in terms of solid content) of the polychloroprene-based latex prepared in Experimental Example 1
AZ-SW (manufactured by Osaki Kogyo Co., Ltd.), a 50% aqueous dispersion of zinc oxide, in an amount of 3 parts by mass (in terms of solid content), and Primal RM-8W, a water-soluble polyurethane-based thickener (Rohm and Haas)・ 0.06
The polychloroprene-based latex composition G was mixed by mass parts (in terms of solid content). The light discoloration resistance of the polychloroprene-based latex composition G was evaluated in the same manner as in Example 1.

Comparative Example 3 100 parts by mass (in terms of solid content) of the polychloroprene-based latex prepared in Experimental Example 1
2 parts by weight of zinc oxide powder (manufactured by Sakai Chemical Industry Co., Ltd.) in an amount of 4 parts by mass (in terms of solid content), and a water-soluble polyurethane-based thickener Primal RM-8W (available from Rohm and Haas Japan Ltd.) 0.06 parts by mass (solid content) was mixed to obtain a polychloroprene-based latex composition H. The light discoloration resistance of the polychloroprene-based latex composition H was evaluated in the same manner as in Example 1.

Comparative Example 4 100 parts by mass (in terms of solid content) of the polychloroprene-based latex prepared in Experimental Example 1
Against a 30% aqueous dispersion of zinc oxide Nanotek
2 parts by mass (solid content) of ZnO (manufactured by C-I Kasei Co., Ltd.), Primal, a water-soluble polyurethane-based thickener
0.06 parts by mass (solid content) of RM-8W (manufactured by Rohm and Haas Japan K.K.), Tamanol E-10, a terpene phenol-based tackifying resin emulsion
0 (manufactured by Arakawa Chemical Industries, Ltd.) was mixed in an amount of 45 parts by mass (in terms of solid content) to obtain a polychloroprene-based latex composition I. The light discoloration resistance of the polychloroprene latex composition I was evaluated in the same manner as in Example 1.

Comparative Example 5 100 parts by mass (in terms of solid content) of the polychloroprene-based latex prepared in Experimental Example 1
AZ-SW (manufactured by Osaki Kogyo Co., Ltd.), a 50% aqueous dispersion of zinc oxide, in an amount of 3 parts by mass (in terms of solid content), and Primal RM-8W, a water-soluble polyurethane-based thickener (Rohm and Haas)・ 0.06
A polychloroprene-based latex composition J was prepared by mixing 45 parts by mass (in terms of solids) of Tamanol E-100 (manufactured by Arakawa Chemical Industries, Ltd.) of a terpene phenol-based tackifying resin emulsion. The light discoloration resistance of the polychloroprene-based latex composition J was evaluated in the same manner as in Example 1.

Comparative Example 6 An aqueous dispersion A was prepared in the same manner as in Example 1. The polychloroprene-based latex prepared in Experimental Example 1 was used in an amount of 100 parts by mass (in terms of solid content) with respect to Prima, a water-soluble polyurethane-based thickener.
l RM-8W (manufactured by Rohm and Haas Japan K.K.) was mixed with 0.06 parts by mass (in terms of solids) and 2 parts by mass (in terms of solids) of the aqueous dispersion A to obtain a polychloroprene-based latex composition. It was set to K. The light discoloration resistance of the polychloroprene-based latex composition K was evaluated in the same manner as in Example 1.

Comparative Example 7 100 parts by mass (in terms of solid content) of the polychloroprene-based latex prepared in Experimental Example 1
In contrast, Primal water-soluble polyurethane thickener
0.06 parts by mass (solid content) of RM-8W (manufactured by Rohm and Haas Japan K.K.), Tamanol E-10, a terpene phenol-based tackifying resin emulsion
0 (manufactured by Arakawa Chemical Industry Co., Ltd.) was mixed with 45 parts by mass (in terms of solids), and 2 parts by mass (in terms of solids) of the aqueous dispersion A to obtain a polychloroprene latex composition L. Example 1 shows the light discoloration resistance of polychloroprene latex composition L
Was evaluated in the same manner as described above. Examples 1 to 5, Comparative Examples 1 to 7
Are shown in Tables 1 to 3.

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

[Table 3]

The additives used in Tables 1 to 3 are shown below. Note 1) 30% aqueous dispersion of zinc oxide / Nanotek Z
nO (manufactured by C-I Kasei Co., Ltd.) Note 2) 50% aqueous dispersion of zinc oxide / AZ-SW (manufactured by Osaki Industry Co., Ltd.) Note 3) Zinc oxide powder / zinc flower 2 types (manufactured by Sakai Chemical Industry Co., Ltd.) Note 4) Water soluble polyurethane thickener / Primal®
M-8W (manufactured by Rohm and Haas Japan KK) Note 5) Terpene phenol resin emulsion / Tamanol E-100 (manufactured by Arakawa Chemical Industries, Ltd.) Note 6) Synthetic hydrotalcite / Kyoward 500
(28.6% aqueous dispersion of Kyowa Chemical Industry Co., Ltd.)

[0050]

In Tables 1 to 3, the polychloroprene-based latex compositions of the present invention (Examples 1 to 5) were obtained by mixing the zinc oxide alone with the polychloroprene-based latex compositions (Comparative Examples 1 to 5). This indicates that the decrease in the brightness (L *) and the hunter whiteness (W (Lab)) is smaller than that in the case where the blackening caused by zinc oxide is suppressed. Also,
The polychloroprene-based latex compositions of the present invention (Examples 1 to 5) exhibited lower brightness and Hunter whiteness than the polychloroprene-based latex compositions containing only hydrotalcite (Comparative Examples 6 and 7). It is small and has excellent light discoloration resistance.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 AC091 DE106 DE287 GJ01 HA07 4J040 CA141 HA136 HA316 JB05 LA07 LA10 MA02 MA04 MA05 MA06 MA08 MA09 MA10 MA12 NA05 NA12 NA16

Claims (4)

[Claims] 1. A polychloroprene latex composition comprising a chloroprene polymer, zinc oxide and a hydrotalcite compound. 2. The polychloroprene latex composition according to claim 1, wherein the hydrotalcite compound is hydrotalcite. 3. An aqueous adhesive comprising the polychloroprene latex composition according to claim 1 or 2. 4. An adhesive structure bonded via the water-based adhesive according to claim 3.