JP3652859B2 - Chloroprene-based copolymer latex and adhesive composition thereof - Google Patents

Description

【００４５】
但し、表中の添加剤は下記の通り。
注１）オクチルフェノキシエトキシエチルスルホン酸ナトリウム
注２）ナフタレンスルホン酸ナトリウム−ホルムアルデヒド縮合物
注３）２，６−ターシャリ−ブチル−４−メチルフェノール
注４）大崎工業株式会社製ＡＺ−ＳＷ
注５）荒川化学工業社製タマノールＥ−１００
【００４６】
【発明の効果】
以上のように、本発明により、初期接着強度、常態接着強度、耐熱性及び耐水性に優れた接着剤を得るクロロプレン系共重合体ラテックス及び各種被着体の接着に好適な接着剤組成物が得られる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chloroprene copolymer latex for obtaining an adhesive composition having an excellent balance between initial adhesive strength, normal adhesive strength and heat resistance, and an adhesive composition using the same. More specifically, it is a copolymer of a chloroprene monomer and an α, β-unsaturated carboxylic acid, and contains a specific organic solvent insoluble part and a soluble part, so that it has excellent initial adhesive strength and normal state adhesiveness. The present invention relates to a chloroprene copolymer latex for obtaining an adhesive composition having an excellent balance of strength, heat resistance and water resistance, and an adhesive composition using the same.
[0002]
[Prior art]
A method for producing a copolymer latex of chloroprene and an α, β-unsaturated carboxylic acid is known from JP-A-50-22047 and JP-A-50-22084. Further, regarding an adhesive composition using a copolymer latex of chloroprene and a carboxyl group-containing vinyl monomer, JP-A-8-27448, JP-A-8-188761, JP-A-8-218044, etc. Is known. However, it has been difficult to obtain a sufficient initial adhesive force, heat resistance, and balance thereof with the conventional technology.
[0003]
[Problems to be solved by the invention]
The present invention provides a chloroprene copolymer latex for obtaining an adhesive composition excellent in initial adhesive strength, normal adhesive strength, heat resistance, water resistance and balance thereof, and an adhesive composition using the same. is there.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the problems of the above chloroprene aqueous adhesive, the present inventors have found that a good balance of adhesion can be obtained by using a chloroprene latex having a specific molecular structure.
That is, the present invention is a copolymer of a chloroprene monomer and an α, β-unsaturated carboxylic acid, in which a 0.6 wt% toluene solution of the copolymer includes an insoluble portion, and the insoluble portion is This is a chloroprene copolymer latex having a weight average molecular weight of 270,000 or more and less than 750,000 which is 35% by weight or more and less than 75% by weight of the coalescence and 0.6% by weight of the toluene solution soluble portion.
Furthermore, the present invention is a copolymer obtained by polymerization using an emulsifier and / or a dispersant, wherein the emulsifier and / or dispersant imparting latex stability is represented by the following formula: It is a copolymer latex.
_{R-Ph- (OCH 2 CH 2} ) n-X
Here, X represents SO ₃ Na and / or OSO ₃ Na, n represents an integer of 2 to 8, R represents an alkyl group having 4 to 18 carbon atoms, and Ph represents a phenylene group.
The present invention also provides a chloroprene aqueous adhesive composition containing the above chloroprene copolymer latex.
[0005]
Hereinafter, the present invention will be described in detail. The latex of the present invention is a copolymer of a chloroprene monomer and an α, β-unsaturated carboxylic acid, and contains a chloroprene copolymer having a specific sol / gel structure in its molecular structure. It has initial adhesiveness, normal adhesiveness, heat resistance and water resistance.
[0006]
The chloroprene monomer in the present invention is 2-chloro-1,3-butadiene (hereinafter referred to as chloroprene) alone, or 1-chloro-1,3-butadiene in a range that does not impair the purpose of the present invention. It may be a mixture with 3-dichloro-1,3-butadiene.
The α, β-unsaturated carboxylic acid used in the present invention is acrylic acid, methacrylic acid, 2-ethylacrylic acid, 2-propylacrylic acid, 2-butylacrylic acid, itaconic acid, and the like. It can be used by mixing.
[0007]
The addition amount of the α, β-unsaturated carboxylic acid is preferably 0.5 parts by weight or more and less than 10 parts by weight, more preferably 1 part by weight or more and 5 parts by weight or less with respect to 100 parts by weight of chloroprene. If it is less than 0.5 part by weight, sufficient heat resistance cannot be imparted, and if it is 10 parts by weight or more, the adhesive strength is insufficient.
[0008]
The emulsifier and / or dispersant used in the present invention is not particularly limited, and various anionic and nonionic types can be used.
[0009]
In the anion type, there are carboxylate, sulfonate, sulfate and the like, but sulfonic acid type is preferable, alkyl allyl sulfonate such as sodium dodecylbenzene sulfonate and sodium isopropyl naphthalene sulfonate, condensed naphthalene sulfonic acid Sodium, polycondensates of alkyl allyl sulfonates such as sodium salt of β-naphthalene sulfonic acid formalin condensate, alkyl sulfo succinates such as sodium dioctyl sulfosuccinate and sodium dihexyl sulfosuccinate, octylbenzene polyoxyethylene sulfone There are alkylaryl polyoxyalkylene sulfonates such as sodium acid, sodium nonylbenzene polyoxyethylene sulfonate, etc., but the alkylphenyl sulfonic acid type of the following formula has polymerization stability and adhesiveness. Desirable in terms of.
_{R-Ph- (OCH 2 CH 2} ) n-X
Here, X represents SO ₃ Na and / or OSO ₃ Na, n represents an integer of 2 to 8, R represents an alkyl group having 4 to 18 carbon atoms, and Ph represents a phenylene group.
[0010]
The amount of the emulsifier and / or dispersant used in the present invention is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the initially charged chloroprene monomer, and more preferably 3 to 7 parts by weight. preferable. If it is less than 1 part by weight, the emulsifying power is insufficient, and if it is 10 parts by weight or more, the viscosity becomes excessive, and there is a concern about the generation of a coagulated product.
[0011]
The gel content in the chloroprene copolymer latex of the present invention and the molecular weight of the 0.6 wt% toluene solution soluble part of the copolymer are the polymerization temperature, polymerization catalyst, chain transfer agent, polymerization terminator, final polymerization rate The polymerization method is not particularly limited.
[0012]
The polymerization temperature may be in the range of 5 ° C. or more and less than 80 ° C., and is not particularly limited, but is preferably 30 ° C. or more and less than 50 ° C.
The polymerization catalyst is a persulfate such as potassium persulfate, an organic peroxide such as 3-butyl hydroperoxide, and the like, and is not particularly limited.
[0013]
There are no particular restrictions on the type of chain transfer agent, and those usually used for emulsion polymerization of chloroprene can be used, but xanthates or mercaptans are preferred. The chain transfer agent can be added at the time of preparation or during the polymerization to contribute to control of the target molecular structure.
[0014]
The polymerization terminator is not particularly limited, and for example, 2,6-tertiarybutyl-4-methylphenol, phenothiazine, hydroxyamine and the like can be used.
The final polymerization rate is arbitrarily adjusted in order to control the properties of the target chloroprene copolymer.
[0015]
The adhesion performance imparted by the chloroprene copolymer latex of the present invention depends on its molecular structure, i.e., by the sol / gel structure. First, the 0.6 wt% toluene solution insoluble part of the copolymer is 35 wt% or more and less than 75 wt% of the copolymer, preferably 35 wt% or more and 70 wt% or less. When the toluene solution insoluble part is small, the heat resistance tends to be inferior, and when it is large, the initial adhesiveness tends to be insufficient.
The gel content was measured by the following method. The latex is freeze-dried (weight is A), dissolved in toluene (adjusted to 0.6% by weight) at 23 ° C. for 20 hours, centrifuged, and further insoluble using a 200 mesh wire mesh. The gel was separated. The gel was air-dried and then dried at 110 ° C. for 1 hour (weight is B). The gel content was calculated according to the following formula.
Gel content = B / A × 100 (%)
[0016]
The weight average molecular weight of the soluble part of the 0.6 wt% toluene solution is 270,000 to less than 750,000, preferably 350,000 to less than 750,000, more preferably 450,000 to less than 750,000. If it is less than 270,000, the heat resistance is insufficient, and if it is 750,000 or more, the initial and normal adhesive strength is insufficient.
[0017]
To the chloroprene copolymer latex of the present invention, a compounding agent usually blended in the latex, for example, an anti-aging agent, a vulcanizing agent, a thickening agent, a PH adjusting agent, and the like can be optionally added.
[0018]
The chloroprene copolymer latex of the present invention can be added with commonly used resins for imparting adhesion, and further optionally added with metal oxides, metal hydroxides, curing agents, etc. Can be prepared. Moreover, a weathering agent, an antifungal agent, a filler, etc. can be added arbitrarily and the performance provision of an adhesive composition can be aimed at.
[0019]
When using a resin, it is preferably added in the form of an emulsion or the like, but a resin such as a modified rosin-based, polymerized rosin-based, terpene-based, phenol-based, chromanindene-based, aliphatic hydrocarbon-based, aromatic petroleum-based resin, etc. These can be used alone or in combination. The amount of these resins added can be arbitrarily varied depending on the resin type, composition, and application, but is preferably 100 parts by weight or less of the solid content of the resin with respect to 100 parts by weight of the solid content of the chloroprene copolymer latex. More preferably, it is at least 70 parts by weight. When the amount exceeds 100 parts by weight, the adhesiveness is lowered, which is not preferable.
[0020]
Examples of the metal oxide or metal hydroxide include zinc oxide, zinc hydroxide, calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide and the like. These addition amounts are preferably 0.5 parts by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the solid content of the chloroprene copolymer latex.
[0021]
Examples of the curing agent include polyisocyanate, epoxy resin, urea resin and the like. These addition amounts are desirably 0.5 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the solid content of the chloroprene copolymer latex.
[0022]
The adhesive composition using the chloroprene copolymer latex of the present invention is the same or different types of paper, wood, cloth, leather, leather, rubber, plastic, urethane foam, plastic foam, earthenware, glass, ceramic, metal, etc. It can be suitably used for bonding each other.
[0023]
【Example】
Examples will be described below, but the present invention is not limited to these examples. Here, the initial adhesive strength, normal adhesive strength, heat-resistant creep test, and water resistance of the adhesive were evaluated by the following methods. In the following description, addition amounts and the like are based on weight unless otherwise specified.
[0024]
[Initial adhesive strength]
200 g of the adhesive composition was applied to each of two canvases (25 × 150 mm) with a brush, dried in a 70 ° C. atmosphere for 6 minutes, and then the coated surface was laminated and pressed with a hand roller. Ten minutes after pressing, the 180 ° peel strength was measured with a tensile tester at a pulling speed of 50 mm / min.
[0025]
[Normal adhesive strength]
200 g of the adhesive composition was applied to each of two canvases (25 × 150 mm) with a brush, dried in a 70 ° C. atmosphere for 6 minutes, and then the coated surface was laminated and pressed with a hand roller. Five days after pressing, 180 ° peel strength was measured with a tensile tester at a pulling speed of 50 mm / min.
[0026]
[Heat resistant creep test]
200 g of the adhesive composition was applied to each of two canvases (25 × 150 mm) with a brush, dried in a 70 ° C. atmosphere for 6 minutes, and then the coated surface was laminated and pressed with a hand roller. After pressing for 24 hours, leave in an 80 ° C. atmosphere for 20 minutes, then apply a 1 kg load in the manner of performing a 180 ° peel test in an 80 ° C. atmosphere, leave for 30 minutes, during which the length of the canvas shifted ( mm).
[0027]
[Water resistance]
200 g of the adhesive composition was applied to each of two canvases (25 × 150 mm) with a brush, dried in a 70 ° C. atmosphere for 6 minutes, and then the coated surface was laminated and pressed with a hand roller. After 24 hours of pressing, the film was immersed in water for 2 days, and then the 180 ° peel strength was measured with a tensile tester at a tensile speed of 50 mm / min.
[0028]
The molecular weight and gel content were measured by the following methods.
(Molecular weight measurement)
GPC measurement was performed under the following conditions. The molecular weight was calculated in terms of polystyrene. As a sample, the separated sol was prepared in a 0.1 wt% THF solution.
Column: PL gel 10 μm GUARD +
PL gel 10 μm Mixed-B × 3 column size: 7.5 mmφ × 50 mm (GUARD), 7.5 mmφ × 300 mm (Mixed-B)
Column temperature: 35 ° C., solvent: THF, flow rate: 1 ml / min
Detector: SIMADZU RID-6A
[0029]
[Gel content measurement]
A latex sample was freeze-dried and precisely weighed. It was dissolved in toluene (prepared to 0.6%) at 23 ° C. for 20 hours, and the gel was separated using a centrifuge and further using a 200-mesh wire mesh. The gel was air-dried and then dried in an atmosphere at 110 ° C. for 1 hour, and weighed precisely to obtain B. The gel content was calculated according to the following formula.
Gel content = B / A × 100 (%)
[0030]
[Example 1]
Polymerization was carried out while adding a 2% aqueous solution of potassium persulfate as a catalyst under a nitrogen atmosphere at the formulation and polymerization temperature shown in Table 1, and when the polymerization rate reached 98%, thiodiphenylamine was converted to 100% by weight of the initial chloroprene monomer. 0.02 part by weight with respect to the part, the reaction was stopped, and then the water was evaporated under reduced pressure and concentrated to adjust the solid content concentration to 55%. Obtained.
[0031]
The resulting latex was blended with the adhesive formulation of Table 1 to obtain an adhesive composition.
The evaluation results of the obtained adhesive composition are shown in Table 1. The initial bond strength, normal bond strength and water resistance strength were good. It also has a good balance of adhesion performance including heat-resistant creep values.
[0032]
[Example 2]
Polymerization was carried out while adding a 2% aqueous solution of potassium persulfate as a catalyst under a nitrogen atmosphere at the formulation and polymerization temperature shown in Table 1, and when the polymerization rate reached 98%, thiodiphenylamine was converted to 100% by weight of the initial chloroprene monomer. 0.02 part by weight was added to the part to stop the reaction, and concentrated in the same manner as in Example 1 to obtain latex having the properties shown in Table 1.
[0033]
The resulting latex was blended with the adhesive formulation of Table 1 to obtain an adhesive composition.
The evaluation results of the obtained adhesive composition are shown in Table 1. The initial bond strength, normal bond strength, heat resistant creep and water resistant strength were good. Moreover, it has a good adhesion performance balance.
[0034]
Example 3
Polymerization was carried out while adding a 2% aqueous solution of potassium persulfate as a catalyst under a nitrogen atmosphere at the formulation and polymerization temperature shown in Table 1, and when the polymerization rate reached 98%, thiodiphenylamine was converted to 100% by weight of the initial chloroprene monomer. 0.02 part by weight was added to the part to stop the reaction, and concentrated in the same manner as in Example 1 to obtain latex having the properties shown in Table 1.
[0035]
The resulting latex was blended with the adhesive formulation of Table 1 to obtain an adhesive composition.
The evaluation results of the obtained adhesive composition are shown in Table 1. The initial bond strength, normal bond strength, heat resistant creep and water resistant strength were good. Moreover, it has a good adhesion performance balance.
[0036]
Example 4
Polymerization was carried out while adding a 2% aqueous solution of potassium persulfate as a catalyst under a nitrogen atmosphere at the formulation and polymerization temperature shown in Table 1, and when the polymerization rate reached 98%, thiodiphenylamine was converted to 100% by weight of the initial chloroprene monomer. 0.02 part by weight was added to the part to stop the reaction, and concentrated in the same manner as in Example 1 to obtain latex having the properties shown in Table 1.
[0037]
The resulting latex was blended with the adhesive formulation of Table 1 to obtain an adhesive composition.
The initial bond strength, normal bond strength, heat resistant creep and water resistant strength were good. Moreover, it has a good adhesion performance balance.
[0038]
Example 5
Polymerization was carried out while adding a 2% aqueous solution of potassium persulfate as a catalyst under a nitrogen atmosphere at the formulation and polymerization temperature shown in Table 1, and when the polymerization rate reached 98%, thiodiphenylamine was converted to 100% by weight of the initial chloroprene monomer. 0.02 part by weight was added to the part to stop the reaction, and concentrated in the same manner as in Example 1 to obtain latex having the properties shown in Table 1.
[0039]
The resulting latex was blended with the adhesive formulation of Table 1 to obtain an adhesive composition.
The initial bond strength, normal bond strength, heat resistant creep and water resistant strength were good. Moreover, it has a good adhesion performance balance.
[0040]
Next, Table 1 shows a comparative example.
[Comparative Example 1]
Polymerization was carried out while adding a 2% aqueous solution of potassium persulfate as a catalyst under a nitrogen atmosphere at the formulation and polymerization temperature shown in Table 1, and when the polymerization rate reached 98%, thiodiphenylamine was converted to 100% by weight of the initial chloroprene monomer. 0.02 part by weight was added to the part to stop the reaction, and concentrated in the same manner as in Example 1 to obtain latex having the properties shown in Table 1.
[0041]
The resulting latex was blended with the adhesive formulation of Table 1 to obtain an adhesive composition.
The evaluation results of the obtained adhesive composition are shown in Table 1. The initial bond strength, normal bond strength and water resistance strength are low.
[0042]
[Comparative Example 2]
Polymerization was carried out while adding a 2% aqueous solution of potassium persulfate as a catalyst under a nitrogen atmosphere at the formulation and polymerization temperature shown in Table 1, and when the polymerization rate reached 98%, thiodiphenylamine was converted to 100% by weight of the initial chloroprene monomer. 0.02 part by weight was added to the part to stop the reaction, and concentrated in the same manner as in Example 1 to obtain latex having the properties shown in Table 1.
[0043]
The resulting latex was blended with the adhesive formulation of Table 1 to obtain an adhesive composition.
The evaluation results of the obtained adhesive composition are shown in Table 1. Although the initial bond strength was good, the normal bond strength and water resistance were low, and complete peeling occurred in the heat-resistant creep test.
[0044]
[Table 1]

[0045]
However, the additives in the table are as follows.
Note 1) Sodium octylphenoxyethoxyethyl sulfonate Note 2) Sodium naphthalene sulfonate-formaldehyde condensate Note 3) 2,6-tert-butyl-4-methylphenol Note 4) AZ-SW manufactured by Osaki Kogyo Co., Ltd.
Note 5) Tamanol E-100 manufactured by Arakawa Chemical Industries
[0046]
【The invention's effect】
As described above, according to the present invention, an adhesive composition suitable for bonding chloroprene copolymer latex and various adherends to obtain an adhesive having excellent initial adhesive strength, normal adhesive strength, heat resistance and water resistance is provided. can get.

Claims (3)

A copolymer obtained by polymerizing a chloroprene monomer and an α, β-unsaturated carboxylic acid using an anionic or nonionic emulsifier and / or a dispersant, wherein A chloroprene copolymer having a 6% by weight toluene solution containing an insoluble part, the insoluble part being not less than 35% by weight and less than 75% by weight of the copolymer, and the soluble part having a weight average molecular weight of not less than 270,000 and less than 750,000 A chloroprene copolymer latex characterized by containing a coalescence. The chloroprene copolymer latex according to claim 1, wherein the chloroprene copolymer is a copolymer obtained by polymerization using a compound represented by the following formula.
_{R-Ph- (OCH 2 CH 2} ) n-X
Here, X represents SO ₃ Na and / or OSO ₃ Na, n represents an integer of 2 to 8, R represents an alkyl group having 4 to 18 carbon atoms, and Ph represents a phenylene group. A chloroprene-based aqueous adhesive composition containing the chloroprene-based copolymer latex according to claim 1.