JP2001234141A - Latex for rubber/metal adhesive and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a latex for a rubber/metal adhesive which is prepared by using a copolymer formed from 1,2-dichloro-1,3-butadiene and 1,3-dichloro-1,3- butadiene, both produced as by-products in a 2,3-DCB production process, and which is excellent in bonding rubber or metals. SOLUTION: A monomer mixture containing (A) 90.0-97.0 wt.% 2,3- dichloro-1,3-butadiene, (B) 1.5-5.0 wt.% 1,2-dichloro-1,3-butadiene, and (C) 1.5-5.0 wt.% 1,3-dichloro-1, 3-butadiene is subjected to redox emulsion polymerization in the presence of a free-radical initiator and then used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolymer latex which is extremely useful as a base material for rubber / metal adhesives, and a method for producing the same.

[0002]

2. Description of the Related Art Rubber / metal adhesives are used in the production process of automobile rubber products, industrial rubber products, building rubber products and the like, and are extremely useful.

[0003] In rubber / metal adhesives, a 2,3-dichloro-1,3-butadiene (hereinafter, referred to as 2,3-DCB) (co) polymer is blended as an essential component.

[0004] Conventionally, since these are organic solvent type adhesives, it is necessary that the 2,3-DCB copolymer be dissolved in these solvents. Usually, 2,3-DCB homopolymers are hardly soluble in organic solvents, and therefore brominated polymers or expensive and toxic monomers such as α-haloacrylonitrile and α-chlorostyrene are used. Solubility is imparted by copolymerization. For example, US
P-2725373 describes a method for imparting solubility by bromination, and USP-3562192 describes a method for imparting solubility by copolymerization with acrylonitrile, chlorostyrene and the like.

In recent years, the organic solvents used in these adhesives are being restricted by increasing awareness of environmental purification, occupational health and safety, etc., and the use of non-solvent and water-based adhesives has become a trend of the times. ing. Attempts have been made to make the rubber / metal adhesive water-based, for example, USP
No. 5,036,122, US Pat. No. 5,200,459, and JP-A-2-1793.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process for producing 2,3-DCB by-produced 1,2-DCB having improved adhesion without using expensive and toxic monomers. Dichloro-1,3-butadiene and 1,3-dichloro-
An object of the present invention is to provide a latex for a rubber / metal adhesive which is excellent in adhesion of rubber and metal, using a copolymer comprising 1,3-butadiene.

[0007]

In view of such a background, the present inventors have developed 2,3-DCB in the above-mentioned adhesive application.
As a result of intensive studies on the influence of the monomer copolymerized with the monomer, the reason is not clear, but 1,2-dichloro-1,3-butadiene by-produced in the process of producing 2,3-DCB,
And a latex obtained by copolymerizing an appropriate amount of 1,3-dichloro-1,3-butadiene with 2,3-
It provides an adhesive composition with clearly better rubber / metal adhesion than the latex obtained from DCB monomer alone, and the use of these monomers allows the use of expensive and toxic monomers. The present inventors have found that the use is unnecessary, and have reached the present invention.

That is, the present invention provides the following (A), (B),
The present invention relates to a rubber / metal adhesive latex comprising a copolymer having the composition (C) and a method for producing the same.

(A): 2,3-dichloro-1,3-butadiene 90.
0 to 97.0% by weight (B): 1,2-dichloro-1,3-butadiene 1.5
-5.0% by weight (C): 1,3-dichloro-1,3-butadiene 1.5
-5.0% by weight The composition of (A), (B) and (C) in the copolymer constituting the latex for rubber / metal adhesive of the present invention is as follows:
(A) 90.0 to 97.0% by weight of component, (B) component 1.
5 to 5.0% by weight, and 1.5 to 5.0% by weight of the component (C). Preferably, component (A) is 91.0 to 96.0% by weight, component (B) is 2.0 to 4.5% by weight, and component (C) is 2.
0 to 4.5% by weight.

When the content of the component (A) is less than 90% by weight,
The toughness, which is a characteristic of 2,3-DCB polymer, is not preferred because the toughness is reduced and the adhesive strength as an adhesive is reduced. When the amount exceeds 97% by weight, the reason is not clear. Is unfavorable because the adhesive strength is lowered.
It is not clear why any one of the above components (B) and (C) exceeds 5% by weight or any one of the above components is less than 1.5% by weight, but the strength as an adhesive is reduced. , Preferably each in the range of 2.0-4.5% by weight.

The rubber / metal adhesive latex of the present invention is obtained by emulsion polymerization of the monomer mixture of the above (A), (B) and (C). Emulsion polymerization according to a known method,
Water, a monomer, an emulsifying / dispersing agent, a polymerization initiator, a chain transfer agent, and the like may be emulsified, and polymerization may be performed at a predetermined temperature. Each of the raw materials may be added all at once, sequentially added, or dividedly added. However, since 2,3-DCB has extremely high polymerizability, it is necessary to control the polymerization rate well in order to safely carry out the polymerization. Therefore, the sequential addition or the divisional addition of the monomer is preferable. From the viewpoint of suppressing the scaling during the polymerization, it is more preferable to add the monomers in a divided manner.

The emulsifying / dispersing agent used for the polymerization is not particularly limited, and carboxylic acid type, sulfonic acid type, sulfate type anionic emulsifier and nonionic emulsifier are used. Alkali metal salts of acids, ammonium salts of disproportionated rosin acids, amine salts of disproportionated rosin acids, alkali metal salts of alkyl sulfonic acids,
Amine salts of alkyl sulfonic acids, ammonium salts of alkyl sulfonic acids, alkali metal salts of alkyl sulfates, ammonium salts of alkyl sulfates, amine salts of alkyl sulfates, alkali metal salts of alkyl aryl sulfonic acids, and alkyl aryl sulfonic acids Ammonium salts, amine salts of alkylaryl sulfonic acids,
Alkali metal salts of alkylaryl sulfates, ammonium salts of alkylaryl sulfates, amine salts of alkylaryl sulfates, alkali metal salts of polyoxyethylene alkylaryl ether sulfates, ammonium salts of polyoxyethylene alkylaryl ether sulfates, Amine salt of polyoxyethylene alkyl aryl ether sulfate, alkali metal salt of polyoxyethylene alkyl ether sulfate, ammonium salt of polyoxyethylene alkyl ether sulfate, amine salt of polyoxyethylene alkyl ether sulfate, sodium naphthalene sulfonate Of polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol, sorby Emissions fatty acid esters, polyoxyethylene acyl esters, polyvinyl alcohol, alkali metal salts and amine salts of alkyl diphenyl ether disulfonic acid. Considering the stability at the time of polymerization and the adhesive performance in the case of an adhesive composition, the amount used is 0.5 to 1 with respect to 100 parts by weight of the monomer mixture.
0 parts by weight is preferred.

As the polymerization initiator, known free radical-generating substances, for example, peroxides such as potassium persulfate and ammonium persulfate, and inorganic or organic peroxides such as hydrogen peroxide and t-butyl hydroperoxide are used. be able to. These may be used alone or in reducing substances, for example,
It may be used in a redox system with hydrosulfite, thiosulfate, thiosulfite, ferrous sulfate, ascorbic acid, organic amine, and the like, but a redox system is preferable because it can be polymerized at a lower temperature. In view of the controllability of the polymerization reaction, it is particularly preferable to use only ascorbic acid as the reducing agent used in the present invention. This is because there is an effect of suppressing runaway of the polymerization reaction of 2,3-DCB having extremely high polymerization reactivity. The amount of the free radical-forming substance used is 0.001 to 2 per 100 parts by weight of the monomer mixture.
Parts by weight, preferably 0.01 to 0.5 parts by weight. The reducing substance is used in an amount of 0.0
It is 0.01 to 2 parts by weight, preferably 0.01 to 0.5 part by weight.

The polymerization can be carried out at a temperature of 0 to 80 ° C., preferably 10 to 50 ° C.

Examples of the chain transfer agent include alkyl mercaptan, halogenated hydrocarbon, dialkyl xanthogen disulfide, tetraalkyl thiuram disulfide, α-
And molecular weight regulators such as methylstyrene dimer, 1,1-diphenylethylene and sulfur. The amount is preferably 0.01 to 3 parts by weight based on 100 parts by weight of the monomer mixture.

The timing of terminating the polymerization is not particularly limited, but the polymerization is preferably carried out until the conversion of the monomer is from 60 to 100%, and more preferably from 95 to 100%. When the monomer remains, the monomer may be removed by a monomer strip or the like.

The concentration of the copolymer in the rubber / metal adhesive latex of the present invention is 1 to the total latex weight.
It is 0 to 60% by weight, preferably 20 to 50% by weight.

Examples of the polymerization terminator include commonly used terminators such as hindered phenol compounds such as 2,6-t-butyl-4-methylphenol, phenothiazine, and the like.
Diethylhydroxylamine and the like can be used. These terminators may be added directly to a solution dissolved in an organic solvent and / or 2,3-DCB monomer or the like, or may be added to a product emulsified in water. May be added.

The latex for an adhesive obtained by the present invention can be used alone as an adhesive, but an auxiliary agent for enhancing an adhesive force is blended in order to further enhance the adhesiveness.
Preferably, the adhesion-enhancing aid is an aromatic polynitroso compound, for example, a compound having at least two non-adjacent nitroso groups on the ring of an aromatic hydrocarbon such as benzene or naphthalene. Nitrosobenzene, p-dinitrosobenzene, 2-methyl-1,4-dinitrosobenzene, 2-methyl-5-chloro-1,4-
Dinitrosobenzene, 2-fluoro-1,4-dinitrosobenzene, 2-methoxy-1,3-dinitrosobenzene, 5-chloro-1,3-dinitrosobenzene, 2-benzyl-1,4-dinitroso Examples thereof include benzene, 2-cyclohexyl-1,4-dinitrosobenzene, p-dinitrosonaphthalene, and m-dinitrosonaphthalene.
In addition to the aromatic nitroso compound, chlorinated natural rubber, chlorinated butadiene rubber, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyolefin, chlorinated PVC and other halogen-containing polymers, phenolic resins, amino resins , A petroleum resin, a rosin resin, a rosin ester resin and the like are appropriately compounded for the purpose of enhancing the adhesiveness. The amount of the adhesion-enhancing aid used may be a copolymer 100
5 to 100 parts by weight, preferably 10 to 5 parts by weight based on parts by weight
0 parts by weight. In addition, a pigment, a filler, a plasticizer, and the like may be appropriately blended.

The adhesive using the copolymer latex obtained in the present invention is used as a rubber / metal adhesive, but the rubber and metal to be bonded are not particularly limited. As the rubber, for example, natural rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, butadiene rubber, isoprene rubber, butyl rubber, chloroprene rubber,
Examples include chlorosulfonated polyethylene, chlorinated polyethylene, acrylic rubber, urethane rubber, hydrogenated acrylonitrile butadiene rubber, epichlorohydrin rubber, silicone rubber, fluorine rubber, ethylene propylene diene rubber, and thermoplastic elastomer. Examples of the metal include iron, aluminum, copper, and stainless steel.

The bonding between rubber and metal is usually carried out by the following method. An adhesive is applied to the metal surface polished with sandpaper or the like and dried (the drying conditions are not limited, and air may be air-dried at room temperature or heat may be dried by heating to dry). Adhere the unvulcanized rubber compound to the metal surface,
3-40 at 140-200 ° C while pressing with a press
Heat for a minute. The heating conditions may be appropriately adjusted depending on the vulcanization rate and thickness of the rubber.

[0022]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. The mechanical stability (rubber aggregation rate) of the latex for rubber / metal adhesive and the performance as an adhesive were measured and evaluated by the following methods.

<Mechanical Stability (Rubber Cohesion)> The mechanical stability (rubber cohesion) of the adhesive composition was measured by the Marlon test method (JI).
SK-6387 (1997)).

<Adhesion Test> Chemlock 205 was applied as a primer to three 25 mm × 70 mm × 3 mm iron plates whose surfaces were polished with sandpaper, dried at room temperature for 30 minutes, and then treated with a latex adhesive (the following Examples, 2,3-DCB (co) polymer latex 100 obtained in Comparative Example
To 10 parts by weight of p-dinitrosobenzene) and dried at room temperature for 30 minutes. Subsequently, these three iron plates were arranged in a metal frame of 70 mm × 75 mm, and the unvulcanized adherend rubber compound sheet obtained by the composition shown in Table 1 was placed thereon, and placed at 160 ° C. for 30 minutes. Press vulcanization was performed. After allowing to cool to room temperature, the rubber was cut to match the width of the iron plate to prepare a test piece. The test specimen was 23 ° C,
The 90 ° peel strength was measured using a Tensilon type tensile tester under the conditions of a tensile speed of 50 mm / min. In addition to the peel strength, the adhesion was evaluated by observing the peel state at the interface between the adherend rubber and the iron plate after the peel test.

[0025]

[Table 1]

Example 1 The compositions shown in Table 2 (2,3-DCB and 1,2-dichloro-1,3-butadiene, 1,3-
Monomer mixture 12 of dichloro-1,3-butadiene and the like)
00 g, 4 g of n-dodecyl mercaptan, 250 g of disproportionated potassium rosinate, 20 g of a condensate of sodium naphthalenesulfonate and formaldehyde, 20 g of sodium oleate sulfate, 15 g of sodium hydroxide, and 5935 g of ion-exchanged water in a 10 l autoclave equipped with a stirrer. After stirring for 30 minutes in a nitrogen atmosphere at 20 ° C., 0.56 g of ascorbic acid was added, and an aqueous potassium persulfate solution (0.370 g of potassium persulfate, 0.100 g of sodium anthraquinone sulfonate and ion-exchanged water 4) were added.
(Prepared by dissolving it in 00 g) to continuously initiate polymerization. At a conversion of 80.3%, the addition of an aqueous solution of potassium persulfate as a polymerization terminator was stopped, and the mixture was aged for 1 hour. Thereafter, 1200 g of a monomer mixture having the same composition as the initially charged one was added, and after stirring for 30 minutes, 0.56 g of ascorbic acid was added, and an aqueous solution of potassium persulfate (potassium persulfate 0.370 g, anthraquinone sulfonic acid) was added. 0.100 g of sodium dissolved in 400 g of ion-exchanged water) was added continuously to restart the polymerization. The total conversion was 85.7% (the conversion was calculated by solid content measurement. That is, about 2 g of latex was precisely weighed, and the solid content was calculated by measuring the weight after drying at 170 ° C. × 20 minutes). The conversion was calculated from the solid content value. The same applies to the following Examples and Comparative Examples.) When the potassium persulfate aqueous solution was stopped, the mixture was aged for 1 hour. Thereafter, again, 1200 g of a monomer mixture having the same composition as the initially charged one was added, and the mixture was stirred for 30 minutes.
0.56 g of ascorbic acid was added, and a potassium persulfate aqueous solution (potassium persulfate 0.370 g, sodium anthraquinone sulfonate 0.100 g was replaced with ion-exchanged water 400).
g) and started to be added continuously. At a total conversion of 99.4%, the addition of the aqueous potassium persulfate solution was stopped, and 0.4 g of phenothiazine and 0.4 g of t-butylcatechol were added to obtain a rubber / metal adhesive latex having a solid content of 39.3%. . Table 2 shows the mechanical stability (rubber aggregation rate) of the adhesive composition obtained using this latex. Further, Table 2 shows the adhesive performance when a chloroprene rubber compound was used as the adherend rubber compound shown in Table 1. It is clear that both the mechanical stability (rubber agglomeration rate) and the adhesive performance are excellent.

[0027]

[Table 2]

Example 2 15 g of sodium hydroxide and 25 of disproportionated potassium rosinate
Instead of using 0 g and 20 g of sodium sulfate of oleic acid, the same method as in Example 1 was used except that 250 g of Perex SSH (manufactured by Kao) was used and the monomer composition used was changed to the composition shown in Table 2. A latex for a rubber / metal adhesive having a solid content of 39.1% was obtained. Table 2 shows the mechanical stability (rubber cohesion) of the adhesive composition obtained using this latex.
It was shown to. Further, Table 2 shows the adhesive performance when a chloroprene rubber compound was used as the adherend rubber compound shown in Table 1. It is clear that both the mechanical stability (rubber agglomeration rate) and the adhesive performance are excellent.

Example 3 A rubber / metal adhesive latex having a solid content of 39.4% was obtained in the same manner as in Example 1 except that the monomer composition used was changed to the composition shown in Table 2. Table 2 shows the mechanical stability (rubber aggregation rate) of the adhesive composition obtained using this latex. Further, Table 2 shows the adhesive performance when a chloroprene rubber compound was used as the adherend rubber compound shown in Table 1. It is clear that both the mechanical stability (rubber agglomeration rate) and the adhesive performance are excellent.

Example 4 A rubber / metal adhesive latex having a solid content of 39.5% was obtained in the same manner as in Example 1 except that the monomer composition used was changed to the composition shown in Table 2. Table 2 shows the mechanical stability (rubber aggregation rate) of the adhesive composition obtained using this latex. Further, Table 2 shows the adhesive performance when a chloroprene rubber compound was used as the adherend rubber compound shown in Table 1. It is clear that both the mechanical stability (rubber agglomeration rate) and the adhesive performance are excellent.

Example 5 Table 2 shows the adhesive performance when a natural rubber compound was used as the adherend rubber compound shown in Table 1 using the rubber / metal adhesive latex obtained in the same manner as in Example 1. Indicated. It is clear that the adhesion performance is excellent.

Comparative Example 1 A latex for a rubber / metal adhesive having a solid content of 39.5% was obtained in the same manner as in Example 1 except that the monomer composition used was changed to the composition shown in Table 3. Table 3 shows the mechanical stability (rubber agglomeration rate) of the adhesive composition obtained using this latex. Further, Table 3 shows the adhesive performance when a chloroprene rubber compound was used as the adherend rubber compound shown in Table 1. Although the reason is not clear, Examples 1 to
It is clear that the adhesive performance is inferior to that of Example 5.

[0033]

[Table 3]

Comparative Example 2 A rubber / metal adhesive latex having a solid content of 39.6% was obtained in the same manner as in Example 1 except that the monomer composition used was changed to the composition shown in Table 3. Table 3 shows the mechanical stability (rubber agglomeration rate) of the adhesive composition obtained using this latex. Further, Table 3 shows the adhesive performance when a chloroprene rubber compound was used as the adherend rubber compound shown in Table 1. Although the reason is not clear, Examples 1 to
It is clear that the adhesive performance is inferior to that of Example 5.

Comparative Example 3 Table 3 shows the adhesive performance when a natural rubber compound was used as the adherend rubber compound shown in Table 1 using the rubber / metal adhesive latex obtained in the same manner as in Comparative Example 1. Indicated. Although the reason is not clear, it is clear that the adhesive performance is inferior to Examples 1 to 5.

Comparative Example 4 A rubber / metal adhesive latex having a solid content of 39.4% was obtained in the same manner as in Example 1 except that the monomer composition used was changed to the composition shown in Table 3. Table 3 shows the mechanical stability (rubber agglomeration rate) of the adhesive composition obtained using this latex. It is clear that the mechanical stability (rubber aggregation rate) is inferior to those of Examples 1 to 5. Further, Table 3 shows the adhesive performance when a chloroprene rubber compound was used as the adherend rubber compound shown in Table 1. Although the reason is not clear, it is clear that the adhesive performance is inferior to Examples 1 to 5.

Comparative Example 5 A rubber / metal adhesive latex having a solid content of 39.0% was obtained in the same manner as in Example 1 except that the monomer composition used was changed to the composition shown in Table 3. At the end of the polymerization, aggregates of rubber aggregated from the latex were observed in the autoclave. Table 3 shows the mechanical stability (rubber agglomeration rate) of the adhesive composition obtained using this latex. It is clear that the mechanical stability (rubber aggregation rate) is inferior to those of Examples 1 to 5. Further, Table 3 shows the adhesive performance when a chloroprene rubber compound was used as the adherend rubber compound shown in Table 1. Although the reason is not clear, it is clear that the adhesive performance is inferior to Examples 1 to 5.

[0038]

According to the present invention, (A) 90.0 to 97.0% by weight of 2,3-dichloro-1,3-butadiene;
(B) 1,2-dichloro-1,3-butadiene 1.5-
A latex comprising a copolymer having a composition of 5.0% by weight and (C) 1.5 to 5.0% by weight of 1,3-dichloro-1,3-butadiene is a base latex of a rubber / metal adhesive. And is superior to a latex comprising a 2,3-DCB copolymer in which the components (B) and (C) each have a composition of more than 5% by weight or less than 1.5% by weight. The adhesive performance is shown.

Continued on the front page F-term (reference) 4F100 AB01B AB02 AK29A AL01A AN00C BA03 BA07 BA10B BA10C GB07 GB32 JL08A JL11 JM01A 4J011 KA03 KA04 KA10 4J040 CA131 JA03 LA06 MA02 MA12 NA12 NA16 QA01 4J100 AS06P AS03Q03 AS06P AS03Q03

Claims (2)

[Claims] 1. A latex for a rubber / metal adhesive comprising a copolymer having the following composition (A), (B) or (C). (A): 2,3-dichloro-1,3-butadiene 90.
0 to 97.0% by weight (B): 1,2-dichloro-1,3-butadiene 1.5
-5.0% by weight (C): 1,3-dichloro-1,3-butadiene 1.5
~ 5.0% by weight 2. A rubber / metal adhesive according to claim 1, wherein a monomer mixture comprising the following (A), (B) and (C) is subjected to redox emulsion polymerization in the presence of a radical initiator. Of latex for pharmaceutical preparations. (A): 2,3-dichloro-1,3-butadiene 90.
0 to 97.0% by weight (B): 1,2-dichloro-1,3-butadiene 1.5
-5.0% by weight (C): 1,3-dichloro-1,3-butadiene 1.5
~ 5.0% by weight