JP3830374B2 - Polychloroprene latex composition - Google Patents

Description

【００３２】
【発明の効果】
表１，２より明らかな如く、本発明のポリクロロプレン系ラテックス組成物は、良好な接着強度を示し、水系プライマーや水系接着剤として好適に使用できるものである。[0001]
BACKGROUND OF THE INVENTION
The present invention provides a polychloroprene latex composition that exhibits good adhesion strength to adherends such as rubbers, elastomers, and synthetic resins, and is useful as a main raw material for aqueous adhesives and aqueous primers used for these adherends. Give.
[0002]
[Prior art]
Conventionally, solvent-based primers and adhesives have been mainly employed as a method for bonding difficult-to-adhere adherends such as rubber, elastomers, and synthetic resins. However, in the case of a solvent system, a large amount of an organic solvent such as toluene, ethyl acetate, or methyl ethyl ketone is used, which is not preferable in terms of safety and health of workers and the environment.
For this reason, the demand for water-based adhesives and primers has been increasing year by year, and several proposals have been made, for example, JP-A-2001-64616 and JP-A-2001-26756. However, the present situation is that the adhesive strength is still insufficient for practical use.
[0003]
[Problems to be solved by the invention]
In view of the current situation, the present invention provides a polychloroprene latex composition suitable as a main raw material for water-based primers and water-based adhesives that provides adhesive strength comparable to solvent-based primers and adhesives that have been used conventionally. Objective.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have found that a polychloroprene-based latex composition containing polychloroprene and sodium orthosilicate as essential components and dispersed or dissolved in water is a rubber or elastomer. The present inventors have found that an excellent adhesion strength can be imparted to an adherend such as a synthetic resin, thereby completing the present invention.
[0005]
That is, the present invention is a polychloroprene latex composition characterized in that polychloroprene and sodium orthosilicate are essential components and they are dispersed or dissolved in water.
Further, the present invention is a polychloroprene latex composition comprising polychloroprene and sodium orthosilicate as essential components, added with a tackifying resin, and dispersed or dissolved in water.
Furthermore, it is an adhesion method in which the adherend is adhered using these polychloroprene latex composition or water-based primer.
[0006]
Hereinafter, the contents of the present invention will be described in detail. The polychloroprene referred to in the present invention is a homopolymer of 2-chloro-1,3-butadiene (hereinafter referred to as chloroprene) or a copolymer of chloroprene and a monomer copolymerizable with chloroprene. is there. The term “copolymer” as used herein also includes a graft copolymer obtained by graft polymerization of other monomers in the presence of polychloroprene.
[0007]
Examples of the monomer copolymerizable with chloroprene include 2,3-dichloro-1,3-butadiene, 1-chloro-1,3-butadiene, butadiene, isoprene, styrene, acrylonitrile, acrylic acid and esters thereof. , Methacrylic acid and esters thereof, and the like, and two or more kinds may be used as necessary.
[0008]
The polymerization method of polychloroprene is not particularly limited, but a method by emulsion polymerization is common and simple.
In completing the present invention, it is necessary to disperse polychloroprene in water. However, in the case of emulsion polymerization, the obtained polychloroprene latex can be used as it is.
[0009]
The emulsifier and / or dispersant used for the emulsion polymerization of the polychloroprene latex is not particularly limited, and various anionic, nonionic, and cationic types that are usually used for chloroprene latex can be used. Examples of anionic emulsifiers include carboxylic acid type, sulfonic acid type, and sulfuric acid ester type. For example, alkali metal salts of rosin acid, alkyl sulfonates having 8 to 20 carbon atoms, alkyl aryl sulfates, sodium naphthalene sulfonate And condensates of formaldehyde and the like. 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 aliphatic amine salts, aliphatic quaternary ammonium salts, and the like, for example, octadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, dilauryldimethylammonium chloride and the like.
[0010]
The addition amount of the emulsifier and / or dispersant in the polychloroprene latex in the present invention is preferably 0.5 to 20 parts by mass with respect to 100 parts by mass in total of the initially charged monomers. If the amount is less than 0.5 parts by mass, the emulsifying power is not sufficient, and if it exceeds 20 parts by mass, the water-resistant adhesive strength is reduced.
[0011]
The polymerization temperature of the polychloroprene latex in the present invention is not particularly limited, but the polymerization temperature is preferably 0 to 50 ° C. in order to smoothly perform the polymerization reaction.
The polymerization initiator is preferably a persulfate such as potassium persulfate, or an organic peroxide such as 3-butyl hydroperoxide, but is not limited thereto.
[0012]
The kind 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 mercaptans such as n-dodecyl mercaptan and tert-dodecyl mercaptan, dialkylxanthogen disulfides such as diisopropylxanthogen disulfide and diethylxanthogen disulfide, and known chain transfer agents such as iodoform can be used.
[0013]
The polymerization stopper (polymerization inhibitor) for polychloroprene is not particularly limited, and for example, 2,6-tertiarybutyl-4-methylphenol, phenothiazine, hydroxyamine, and the like can be used.
[0014]
The final polymerization rate of polychloroprene is not particularly limited and can be arbitrarily adjusted. Unreacted monomers are removed by the demonomer operation, but the method is not particularly limited.
The polychloroprene-based latex of the present invention can be controlled to a required concentration by concentration or dilution by addition of water or the like. The concentration method includes, but is not limited to, vacuum concentration.
[0015]
The structure of the polychloroprene latex in the present invention is not particularly limited, but the polymerization temperature, polymerization initiator, chain transfer agent, polymerization terminator, final polymerization rate, demonomer, concentration conditions, etc. are appropriately selected. By controlling, it is possible to adjust the solid content concentration, the molecular weight of the toluene soluble part, the toluene insoluble content (gel content), and the like. From the viewpoint of the balance between the initial adhesive force and the normal adhesive force, it is preferable to adjust the gel content of the (co) polymer in the polychloroprene latex to 3 to 60% by weight.
[0016]
Sodium silicate is represented by the general formula _{Na 2 O · nSiO 2 · mH} 2 O, molar ratio of Na ₂ O and SiO _2, i.e. sodium orthosilicate by a factor n, sodium metasilicate, No. 1 sodium silicate, silicic acid Although classified into sodium No. 2, sodium silicate No. 3, sodium silicate No. 4 and the like, sodium orthosilicate is particularly used in the present invention.
The amount of sodium silicate added is not particularly defined, but from the viewpoint of adhesive strength, it is preferably 0.1 to 30 parts by weight, more preferably 1 to 15 parts per 100 parts by weight (solid content) of polychloroprene. Parts by weight.
[0017]
The polychloroprene-based latex composition comprising the polychloroprene and sodium orthosilicate of the present invention as essential components and dispersed or dissolved in water exhibits sufficient adhesive force as it is, but has an initial adhesive strength and water-resistant adhesive strength. In order to make the properties such as the adhesion holding time more practical, it is effective to add a tackifying resin.
[0018]
When the tackifier resin is blended with the water-based adhesive, the type thereof is not particularly limited. Specifically, rosin resin, polymerized rosin resin, α-pinene resin, β-pinene resin, terpene phenol resin, C ₅ fraction petroleum resin, C ₉ fraction petroleum resin, C ₅ / C ₉ fraction Examples include petroleum resins, DCPD petroleum resins, alkylphenol resins, xylene resins, coumarone resins, coumarone indene resins, and the like. In order to obtain a sufficient initial adhesive force, a resin having a softening point temperature of 50 to 160 ° C. is preferable.
[0019]
The method for adding the tackifying resin is not particularly limited, but it is preferable to add it as an aqueous emulsion in order to uniformly disperse the resin in the latex.
Furthermore, the method for producing an aqueous emulsion of a tackifying resin includes a method in which a solution dissolved in an organic solvent such as toluene is emulsified / dispersed in water using an emulsifier, and then the organic solvent is removed by heating under reduced pressure. There is a method of emulsifying / dispersing, and the former, which can produce a finer particle emulsion, is preferable.
[0020]
The solid content concentration of the polychloroprene latex composition of the present invention is not particularly limited, but is preferably 70% by weight or less so as not to impair the stability of the emulsion system.
Further, when the polychloroprene latex composition of the present invention is used as an aqueous adhesive, the solid content concentration is adjusted to 40 to 70% by weight, and when used as an aqueous primer, the solid content concentration is adjusted to 10 to 40% by weight. However, the solid content can be arbitrarily adjusted by dilution with pure water or concentration by removing water.
[0021]
In addition to the above, the polychloroprene latex composition in the present invention has a thickener, a metal oxide, a filler, a film-forming aid, an ultraviolet absorber, an antioxidant, a plasticizer, according to the required performance. Vulcanizing agents, vulcanization accelerators, antifoaming agents and the like can be arbitrarily added.
[0022]
The polychloroprene latex composition of the present invention can be adjusted to an arbitrary viscosity by blending a thickener. Specific examples of the thickener include polyvinyl alcohol (PVA), sodium polyacrylate, water-soluble polyurethane, associative polyurethane emulsion, alkali swelling acrylic emulsion, carboxymethylcellulose (CMC), methylcellulose (MC), and hydroxyethylcellulose. (HEC), hydroxypropyl cellulose (HPC), polyvinyl alcohol, synthetic smectite and the like.
As for the compounding quantity of a thickener, 0.01-10 mass parts (solid content conversion) is suitable with respect to 100 mass parts by solid content of polychloroprene-type latex. By blending in this range, it is possible to adjust the viscosity of the polychloroprene latex composition without adversely affecting the adhesive properties.
[0023]
The material such as rubber, elastomer, and synthetic resin to which the polychloroprene latex composition of the present invention is applied is not particularly limited, but specifically, butadiene rubber (BR), chloroprene rubber (CR). , Natural rubber (NR), isoprene rubber (IR), styrene-butadiene rubber (SBR), butyl rubber (IIR), norbornene rubber (NOR), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), brominated butyl rubber ( Vulcanized rubber such as BIIR), chlorinated butyl rubber (CIIR), acrylonitrile-isoprene copolymer (NIR), ethylene-propylene-diene rubber (EPDM), styrene-butadiene-styrene block copolymer (SBS), polyester Thermoplastic elastomers such as polyurethane, urethane and olefin, Examples include vinyl chloride resin (PVC), ethylene-vinyl acetate copolymer (EVA), 1,2-polybutadiene (RB), polyolefin resin, styrene resin, acrylonitrile-butadiene-styrene copolymer (ABS), and the like. .
Further, the blending composition, crosslinking density, shape and the like of these materials are not particularly limited, and even a foam can be applied. As for the use, it can be suitably used in any field such as grips for sports equipment, shoe soles, and building materials.
[0024]
【Example】
Hereinafter, the effects of the present invention will be described in detail with reference to Examples and Comparative Examples, but these Examples do not limit the present invention. In the following description, parts and% are expressed on a mass basis unless otherwise specified.
[0025]
[Experimental Example 1]
Using a reactor having an internal volume of 3 liters, 100 parts of water, 5 parts of disproportionated rosin acid, 0.6 parts of sodium hydroxide, 0.7 parts of potassium hydroxide, formaldehyde naphthalenesulfonic acid condensate under a nitrogen stream 0.3 part of sodium salt and 0.3 part of sodium hydrogen sulfite were added, and after dissolution, 100 parts of chloroprene monomer and 0.14 part of n-dodecyl mercaptan were added with stirring. Polymerization was carried out at 10 ° C. in a nitrogen atmosphere using potassium persulfate as an initiator. When the polymerization rate reached 90%, an emulsion of phenothiazine was added to terminate the polymerization. Unreacted monomers were removed under reduced pressure to obtain polychloroprene latex. Furthermore, water was evaporated under reduced pressure and concentration was performed, and the solid content was adjusted to 50% by mass.
[0026]
[Example 1]
Using polychloroprene latex obtained in Experimental Example 1, 50 parts of a terpene phenol resin emulsion (Tamanol E-100 / manufactured by Arakawa Chemical Industries, Ltd.) having a solid content concentration of 53% as a tackifying resin is used for 100 parts of polychloroprene latex. 3 parts of a sodium orthosilicate solution (manufactured by Asahi Denka Kogyo Co., Ltd.) having a solid content of 30% was added to obtain a chloroprene aqueous adhesive.
[0027]
200 g (wet) on the surface of a vulcanized styrene butadiene rubber (vulcanized SBR, the size of the adhesive margin is 20 mm in width x 70 mm in length) from which the adhesive surface was buffed (surface polished) and then washed away with acetone. / M ² of chloroprene water-based adhesive was applied with a brush, dried in an atmosphere at 60 ° C. for 6 minutes, and then bonded and pressure-bonded with a hand roller. The following evaluation was performed about the test piece obtained by this method.
[Initial adhesive strength evaluation test]
Ten minutes after the pressure bonding, the T-type peel strength was measured with a tensile tester at a tensile speed of 200 mm / min.
[Normal adhesive strength evaluation test]
One day after the pressure bonding, the T-type peel strength was measured with a tensile tester at a tensile speed of 200 mm / min.
[0028]
[Comparative Example 1]
A test was carried out in the same manner as in Example 1 except that sodium orthosilicate was not used, and it was set as Comparative Example 1.
[0029]
[Comparative Examples 2 to 4]
A test was carried out in the same manner as in Example 1 except that another type of sodium silicate was used instead of sodium orthosilicate, and Comparative Examples 2 to 4 were obtained.
[0030]
The obtained results are shown in Table 1.
[0031]
[Table 1]

[0032]
【The invention's effect】
As is clear from Tables 1 and 2, the polychloroprene latex composition of the present invention exhibits good adhesive strength and can be suitably used as an aqueous primer or an aqueous adhesive.

Claims (3)

 1. A polychloroprene latex composition comprising polychloroprene and sodium orthosilicate as essential components, which are dispersed or dissolved in water.  The polychloroprene latex composition according to claim 1, wherein the content of sodium orthosilicate is 1 to 15 parts by weight per 100 parts by weight of polychloroprene.  Furthermore, the polychloroprene-type latex composition in any one of Claim 1 or Claim 2 containing tackifying resin.